diff options
Diffstat (limited to 'src/grp-resolve')
104 files changed, 32981 insertions, 0 deletions
diff --git a/src/grp-resolve/90-resolved.preset b/src/grp-resolve/90-resolved.preset new file mode 100644 index 0000000000..c5a5063cc1 --- /dev/null +++ b/src/grp-resolve/90-resolved.preset @@ -0,0 +1,11 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. + +# These ones should be enabled by default, even if distributions +# generally follow a default-off policy. + +enable systemd-resolved.service diff --git a/src/grp-resolve/GNUmakefile b/src/grp-resolve/GNUmakefile new file mode 120000 index 0000000000..54fdd42278 --- /dev/null +++ b/src/grp-resolve/GNUmakefile @@ -0,0 +1 @@ +../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/Makefile b/src/grp-resolve/Makefile new file mode 100644 index 0000000000..8132573d49 --- /dev/null +++ b/src/grp-resolve/Makefile @@ -0,0 +1,31 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +nested.subdirs += libbasic-dns +nested.subdirs += nss-resolve +nested.subdirs += systemd-resolve +nested.subdirs += systemd-resolved + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/libbasic-dns/GNUmakefile b/src/grp-resolve/libbasic-dns/GNUmakefile new file mode 120000 index 0000000000..95e5924740 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/GNUmakefile @@ -0,0 +1 @@ +../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/libbasic-dns/Makefile b/src/grp-resolve/libbasic-dns/Makefile new file mode 100644 index 0000000000..7c64e6af5f --- /dev/null +++ b/src/grp-resolve/libbasic-dns/Makefile @@ -0,0 +1,29 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +nested.subdirs += src +nested.subdirs += test + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/dns-type.h b/src/grp-resolve/libbasic-dns/include/basic-dns/dns-type.h new file mode 100644 index 0000000000..df1642f85e --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/dns-type.h @@ -0,0 +1,162 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Zbigniew Jędrzejewski-Szmek + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/macro.h" + +/* DNS record types, taken from + * http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml. + */ +enum { + /* Normal records */ + DNS_TYPE_A = 0x01, + DNS_TYPE_NS, + DNS_TYPE_MD, + DNS_TYPE_MF, + DNS_TYPE_CNAME, + DNS_TYPE_SOA, + DNS_TYPE_MB, + DNS_TYPE_MG, + DNS_TYPE_MR, + DNS_TYPE_NULL, + DNS_TYPE_WKS, + DNS_TYPE_PTR, + DNS_TYPE_HINFO, + DNS_TYPE_MINFO, + DNS_TYPE_MX, + DNS_TYPE_TXT, + DNS_TYPE_RP, + DNS_TYPE_AFSDB, + DNS_TYPE_X25, + DNS_TYPE_ISDN, + DNS_TYPE_RT, + DNS_TYPE_NSAP, + DNS_TYPE_NSAP_PTR, + DNS_TYPE_SIG, + DNS_TYPE_KEY, + DNS_TYPE_PX, + DNS_TYPE_GPOS, + DNS_TYPE_AAAA, + DNS_TYPE_LOC, + DNS_TYPE_NXT, + DNS_TYPE_EID, + DNS_TYPE_NIMLOC, + DNS_TYPE_SRV, + DNS_TYPE_ATMA, + DNS_TYPE_NAPTR, + DNS_TYPE_KX, + DNS_TYPE_CERT, + DNS_TYPE_A6, + DNS_TYPE_DNAME, + DNS_TYPE_SINK, + DNS_TYPE_OPT, /* EDNS0 option */ + DNS_TYPE_APL, + DNS_TYPE_DS, + DNS_TYPE_SSHFP, + DNS_TYPE_IPSECKEY, + DNS_TYPE_RRSIG, + DNS_TYPE_NSEC, + DNS_TYPE_DNSKEY, + DNS_TYPE_DHCID, + DNS_TYPE_NSEC3, + DNS_TYPE_NSEC3PARAM, + DNS_TYPE_TLSA, + + DNS_TYPE_HIP = 0x37, + DNS_TYPE_NINFO, + DNS_TYPE_RKEY, + DNS_TYPE_TALINK, + DNS_TYPE_CDS, + DNS_TYPE_CDNSKEY, + DNS_TYPE_OPENPGPKEY, + + DNS_TYPE_SPF = 0x63, + DNS_TYPE_NID, + DNS_TYPE_L32, + DNS_TYPE_L64, + DNS_TYPE_LP, + DNS_TYPE_EUI48, + DNS_TYPE_EUI64, + + DNS_TYPE_TKEY = 0xF9, + DNS_TYPE_TSIG, + DNS_TYPE_IXFR, + DNS_TYPE_AXFR, + DNS_TYPE_MAILB, + DNS_TYPE_MAILA, + DNS_TYPE_ANY, + DNS_TYPE_URI, + DNS_TYPE_CAA, + DNS_TYPE_TA = 0x8000, + DNS_TYPE_DLV, + + _DNS_TYPE_MAX, + _DNS_TYPE_INVALID = -1 +}; + +assert_cc(DNS_TYPE_SSHFP == 44); +assert_cc(DNS_TYPE_TLSA == 52); +assert_cc(DNS_TYPE_ANY == 255); + +/* DNS record classes, see RFC 1035 */ +enum { + DNS_CLASS_IN = 0x01, + DNS_CLASS_ANY = 0xFF, + + _DNS_CLASS_MAX, + _DNS_CLASS_INVALID = -1 +}; + +#define _DNS_CLASS_STRING_MAX (sizeof "CLASS" + DECIMAL_STR_MAX(uint16_t)) +#define _DNS_TYPE_STRING_MAX (sizeof "CLASS" + DECIMAL_STR_MAX(uint16_t)) + +bool dns_type_is_pseudo(uint16_t type); +bool dns_type_is_valid_query(uint16_t type); +bool dns_type_is_valid_rr(uint16_t type); +bool dns_type_may_redirect(uint16_t type); +bool dns_type_is_dnssec(uint16_t type); +bool dns_type_is_obsolete(uint16_t type); +bool dns_type_may_wildcard(uint16_t type); +bool dns_type_apex_only(uint16_t type); +bool dns_type_needs_authentication(uint16_t type); +bool dns_type_is_zone_transer(uint16_t type); +int dns_type_to_af(uint16_t type); + +bool dns_class_is_pseudo(uint16_t class); +bool dns_class_is_valid_rr(uint16_t class); + +/* TYPE?? follows http://tools.ietf.org/html/rfc3597#section-5 */ +const char *dns_type_to_string(int type); +int dns_type_from_string(const char *s); + +const char *dns_class_to_string(uint16_t class); +int dns_class_from_string(const char *name); + +/* https://tools.ietf.org/html/draft-ietf-dane-protocol-23#section-7.2 */ +const char *tlsa_cert_usage_to_string(uint8_t cert_usage); + +/* https://tools.ietf.org/html/draft-ietf-dane-protocol-23#section-7.3 */ +const char *tlsa_selector_to_string(uint8_t selector); + +/* https://tools.ietf.org/html/draft-ietf-dane-protocol-23#section-7.4 */ +const char *tlsa_matching_type_to_string(uint8_t selector); + +/* https://tools.ietf.org/html/rfc6844#section-5.1 */ +#define CAA_FLAG_CRITICAL (1u << 7) diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-def.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-def.h new file mode 100644 index 0000000000..c4c1915b18 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-def.h @@ -0,0 +1,38 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <inttypes.h> + +#define SD_RESOLVED_DNS (UINT64_C(1) << 0) +#define SD_RESOLVED_LLMNR_IPV4 (UINT64_C(1) << 1) +#define SD_RESOLVED_LLMNR_IPV6 (UINT64_C(1) << 2) +#define SD_RESOLVED_MDNS_IPV4 (UINT64_C(1) << 3) +#define SD_RESOLVED_MDNS_IPV6 (UINT64_C(1) << 4) +#define SD_RESOLVED_NO_CNAME (UINT64_C(1) << 5) +#define SD_RESOLVED_NO_TXT (UINT64_C(1) << 6) +#define SD_RESOLVED_NO_ADDRESS (UINT64_C(1) << 7) +#define SD_RESOLVED_NO_SEARCH (UINT64_C(1) << 8) +#define SD_RESOLVED_AUTHENTICATED (UINT64_C(1) << 9) + +#define SD_RESOLVED_LLMNR (SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_LLMNR_IPV6) +#define SD_RESOLVED_MDNS (SD_RESOLVED_MDNS_IPV4|SD_RESOLVED_MDNS_IPV6) + +#define SD_RESOLVED_PROTOCOLS_ALL (SD_RESOLVED_MDNS|SD_RESOLVED_LLMNR|SD_RESOLVED_DNS) diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-answer.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-answer.h new file mode 100644 index 0000000000..447604d008 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-answer.h @@ -0,0 +1,148 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/macro.h" + +typedef struct DnsAnswer DnsAnswer; +typedef struct DnsAnswerItem DnsAnswerItem; + +#include "resolved-dns-rr.h" + +/* A simple array of resource records. We keep track of the + * originating ifindex for each RR where that makes sense, so that we + * can qualify A and AAAA RRs referring to a local link with the + * right ifindex. + * + * Note that we usually encode the empty DnsAnswer object as a simple NULL. */ + +typedef enum DnsAnswerFlags { + DNS_ANSWER_AUTHENTICATED = 1, /* Item has been authenticated */ + DNS_ANSWER_CACHEABLE = 2, /* Item is subject to caching */ + DNS_ANSWER_SHARED_OWNER = 4, /* For mDNS: RRset may be owner by multiple peers */ +} DnsAnswerFlags; + +struct DnsAnswerItem { + DnsResourceRecord *rr; + int ifindex; + DnsAnswerFlags flags; +}; + +struct DnsAnswer { + unsigned n_ref; + unsigned n_rrs, n_allocated; + DnsAnswerItem items[0]; +}; + +DnsAnswer *dns_answer_new(unsigned n); +DnsAnswer *dns_answer_ref(DnsAnswer *a); +DnsAnswer *dns_answer_unref(DnsAnswer *a); + +int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags); +int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags); +int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl, int ifindex); + +int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags); +int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *combined_flags); +int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags); +int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a); +int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone); + +int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags); +int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags); + +int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret); +int dns_answer_extend(DnsAnswer **a, DnsAnswer *b); + +void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local); + +int dns_answer_reserve(DnsAnswer **a, unsigned n_free); +int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free); + +int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key); +int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rr); + +int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags); +int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags); + +bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname); + +static inline unsigned dns_answer_size(DnsAnswer *a) { + return a ? a->n_rrs : 0; +} + +static inline bool dns_answer_isempty(DnsAnswer *a) { + return dns_answer_size(a) <= 0; +} + +void dns_answer_dump(DnsAnswer *answer, FILE *f); + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref); + +#define _DNS_ANSWER_FOREACH(q, kk, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, (kk) = (UNIQ_T(i, q) < (a)->n_rrs ? (a)->items[UNIQ_T(i, q)].rr : NULL)) + +#define DNS_ANSWER_FOREACH(kk, a) _DNS_ANSWER_FOREACH(UNIQ, kk, a) + +#define _DNS_ANSWER_FOREACH_IFINDEX(q, kk, ifi, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0)) + +#define DNS_ANSWER_FOREACH_IFINDEX(kk, ifindex, a) _DNS_ANSWER_FOREACH_IFINDEX(UNIQ, kk, ifindex, a) + +#define _DNS_ANSWER_FOREACH_FLAGS(q, kk, fl, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0)) + +#define DNS_ANSWER_FOREACH_FLAGS(kk, flags, a) _DNS_ANSWER_FOREACH_FLAGS(UNIQ, kk, flags, a) + +#define _DNS_ANSWER_FOREACH_FULL(q, kk, ifi, fl, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \ + (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0), \ + (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0)) + +#define DNS_ANSWER_FOREACH_FULL(kk, ifindex, flags, a) _DNS_ANSWER_FOREACH_FULL(UNIQ, kk, ifindex, flags, a) diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-dnssec.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-dnssec.h new file mode 100644 index 0000000000..b91abe98ac --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-dnssec.h @@ -0,0 +1,103 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-shared/dns-domain.h" + +typedef enum DnssecResult DnssecResult; +typedef enum DnssecVerdict DnssecVerdict; + +#include "resolved-dns-answer.h" +#include "resolved-dns-rr.h" + +enum DnssecResult { + /* These five are returned by dnssec_verify_rrset() */ + DNSSEC_VALIDATED, + DNSSEC_VALIDATED_WILDCARD, /* Validated via a wildcard RRSIG, further NSEC/NSEC3 checks necessary */ + DNSSEC_INVALID, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_UNSUPPORTED_ALGORITHM, + + /* These two are added by dnssec_verify_rrset_search() */ + DNSSEC_NO_SIGNATURE, + DNSSEC_MISSING_KEY, + + /* These two are added by the DnsTransaction logic */ + DNSSEC_UNSIGNED, + DNSSEC_FAILED_AUXILIARY, + DNSSEC_NSEC_MISMATCH, + DNSSEC_INCOMPATIBLE_SERVER, + + _DNSSEC_RESULT_MAX, + _DNSSEC_RESULT_INVALID = -1 +}; + +enum DnssecVerdict { + DNSSEC_SECURE, + DNSSEC_INSECURE, + DNSSEC_BOGUS, + DNSSEC_INDETERMINATE, + + _DNSSEC_VERDICT_MAX, + _DNSSEC_VERDICT_INVALID = -1 +}; + +#define DNSSEC_CANONICAL_HOSTNAME_MAX (DNS_HOSTNAME_MAX + 2) + +/* The longest digest we'll ever generate, of all digest algorithms we support */ +#define DNSSEC_HASH_SIZE_MAX (MAX(20, 32)) + +int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok); +int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig); + +int dnssec_verify_rrset(DnsAnswer *answer, const DnsResourceKey *key, DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, usec_t realtime, DnssecResult *result); +int dnssec_verify_rrset_search(DnsAnswer *answer, const DnsResourceKey *key, DnsAnswer *validated_dnskeys, usec_t realtime, DnssecResult *result, DnsResourceRecord **rrsig); + +int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke); +int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds); + +int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key); + +uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke); + +int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max); + +int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret); + +typedef enum DnssecNsecResult { + DNSSEC_NSEC_NO_RR, /* No suitable NSEC/NSEC3 RR found */ + DNSSEC_NSEC_CNAME, /* Didn't find what was asked for, but did find CNAME */ + DNSSEC_NSEC_UNSUPPORTED_ALGORITHM, + DNSSEC_NSEC_NXDOMAIN, + DNSSEC_NSEC_NODATA, + DNSSEC_NSEC_FOUND, + DNSSEC_NSEC_OPTOUT, +} DnssecNsecResult; + +int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl); + + +int dnssec_test_positive_wildcard(DnsAnswer *a, const char *name, const char *source, const char *zone, bool *authenticated); + +const char* dnssec_result_to_string(DnssecResult m) _const_; +DnssecResult dnssec_result_from_string(const char *s) _pure_; + +const char* dnssec_verdict_to_string(DnssecVerdict m) _const_; +DnssecVerdict dnssec_verdict_from_string(const char *s) _pure_; diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-packet.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-packet.h new file mode 100644 index 0000000000..8fc031e013 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-packet.h @@ -0,0 +1,303 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <netinet/ip.h> +#include <netinet/udp.h> + +#include "systemd-basic/hashmap.h" +#include "systemd-basic/in-addr-util.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/sparse-endian.h" + +typedef struct DnsPacket DnsPacket; +typedef struct DnsPacketHeader DnsPacketHeader; + +#include "resolved-def.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-question.h" +#include "resolved-dns-rr.h" + +typedef enum DnsProtocol { + DNS_PROTOCOL_DNS, + DNS_PROTOCOL_MDNS, + DNS_PROTOCOL_LLMNR, + _DNS_PROTOCOL_MAX, + _DNS_PROTOCOL_INVALID = -1 +} DnsProtocol; + +struct DnsPacketHeader { + uint16_t id; + be16_t flags; + be16_t qdcount; + be16_t ancount; + be16_t nscount; + be16_t arcount; +}; + +#define DNS_PACKET_HEADER_SIZE sizeof(DnsPacketHeader) +#define UDP_PACKET_HEADER_SIZE (sizeof(struct iphdr) + sizeof(struct udphdr)) + +/* The various DNS protocols deviate in how large a packet can grow, + but the TCP transport has a 16bit size field, hence that appears to + be the absolute maximum. */ +#define DNS_PACKET_SIZE_MAX 0xFFFF + +/* RFC 1035 say 512 is the maximum, for classic unicast DNS */ +#define DNS_PACKET_UNICAST_SIZE_MAX 512 + +/* With EDNS0 we can use larger packets, default to 4096, which is what is commonly used */ +#define DNS_PACKET_UNICAST_SIZE_LARGE_MAX 4096 + +#define DNS_PACKET_SIZE_START 512 + +struct DnsPacket { + int n_ref; + DnsProtocol protocol; + size_t size, allocated, rindex; + void *_data; /* don't access directly, use DNS_PACKET_DATA()! */ + Hashmap *names; /* For name compression */ + size_t opt_start, opt_size; + + /* Parsed data */ + DnsQuestion *question; + DnsAnswer *answer; + DnsResourceRecord *opt; + + /* Packet reception metadata */ + int ifindex; + int family, ipproto; + union in_addr_union sender, destination; + uint16_t sender_port, destination_port; + uint32_t ttl; + + /* For support of truncated packets */ + DnsPacket *more; + + bool on_stack:1; + bool extracted:1; + bool refuse_compression:1; + bool canonical_form:1; +}; + +static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { + if (_unlikely_(!p)) + return NULL; + + if (p->_data) + return p->_data; + + return ((uint8_t*) p) + ALIGN(sizeof(DnsPacket)); +} + +#define DNS_PACKET_HEADER(p) ((DnsPacketHeader*) DNS_PACKET_DATA(p)) +#define DNS_PACKET_ID(p) DNS_PACKET_HEADER(p)->id +#define DNS_PACKET_QR(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 15) & 1) +#define DNS_PACKET_OPCODE(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 11) & 15) +#define DNS_PACKET_AA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 10) & 1) +#define DNS_PACKET_TC(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 9) & 1) +#define DNS_PACKET_RD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 8) & 1) +#define DNS_PACKET_RA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 7) & 1) +#define DNS_PACKET_AD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 5) & 1) +#define DNS_PACKET_CD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 4) & 1) + +#define DNS_PACKET_FLAG_TC (UINT16_C(1) << 9) + +static inline uint16_t DNS_PACKET_RCODE(DnsPacket *p) { + uint16_t rcode; + + if (p->opt) + rcode = (uint16_t) (p->opt->ttl >> 24); + else + rcode = 0; + + return rcode | (be16toh(DNS_PACKET_HEADER(p)->flags) & 0xF); +} + +static inline uint16_t DNS_PACKET_PAYLOAD_SIZE_MAX(DnsPacket *p) { + + /* Returns the advertised maximum datagram size for replies, or the DNS default if there's nothing defined. */ + + if (p->opt) + return MAX(DNS_PACKET_UNICAST_SIZE_MAX, p->opt->key->class); + + return DNS_PACKET_UNICAST_SIZE_MAX; +} + +static inline bool DNS_PACKET_DO(DnsPacket *p) { + if (!p->opt) + return false; + + return !!(p->opt->ttl & (1U << 15)); +} + +static inline bool DNS_PACKET_VERSION_SUPPORTED(DnsPacket *p) { + /* Returns true if this packet is in a version we support. Which means either non-EDNS or EDNS(0), but not EDNS + * of any newer versions */ + + if (!p->opt) + return true; + + return DNS_RESOURCE_RECORD_OPT_VERSION_SUPPORTED(p->opt); +} + +/* LLMNR defines some bits differently */ +#define DNS_PACKET_LLMNR_C(p) DNS_PACKET_AA(p) +#define DNS_PACKET_LLMNR_T(p) DNS_PACKET_RD(p) + +#define DNS_PACKET_QDCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->qdcount) +#define DNS_PACKET_ANCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->ancount) +#define DNS_PACKET_NSCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->nscount) +#define DNS_PACKET_ARCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->arcount) + +#define DNS_PACKET_MAKE_FLAGS(qr, opcode, aa, tc, rd, ra, ad, cd, rcode) \ + (((uint16_t) !!(qr) << 15) | \ + ((uint16_t) ((opcode) & 15) << 11) | \ + ((uint16_t) !!(aa) << 10) | /* on LLMNR: c */ \ + ((uint16_t) !!(tc) << 9) | \ + ((uint16_t) !!(rd) << 8) | /* on LLMNR: t */ \ + ((uint16_t) !!(ra) << 7) | \ + ((uint16_t) !!(ad) << 5) | \ + ((uint16_t) !!(cd) << 4) | \ + ((uint16_t) ((rcode) & 15))) + +static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) { + return + (unsigned) DNS_PACKET_ANCOUNT(p) + + (unsigned) DNS_PACKET_NSCOUNT(p) + + (unsigned) DNS_PACKET_ARCOUNT(p); +} + +int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu); +int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled); + +void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated); + +DnsPacket *dns_packet_ref(DnsPacket *p); +DnsPacket *dns_packet_unref(DnsPacket *p); + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsPacket*, dns_packet_unref); + +int dns_packet_validate(DnsPacket *p); +int dns_packet_validate_reply(DnsPacket *p); +int dns_packet_validate_query(DnsPacket *p); + +int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key); + +int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start); +int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start); +int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start); +int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start); +int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start); +int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_t *start); +int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, bool canonical_candidate, size_t *start); +int dns_packet_append_name(DnsPacket *p, const char *name, bool allow_compression, bool canonical_candidate, size_t *start); +int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start); +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start); +int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, int rcode, size_t *start); +int dns_packet_append_question(DnsPacket *p, DnsQuestion *q); +int dns_packet_append_answer(DnsPacket *p, DnsAnswer *a); + +void dns_packet_truncate(DnsPacket *p, size_t sz); +int dns_packet_truncate_opt(DnsPacket *p); + +int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start); +int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start); +int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start); +int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start); +int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start); +int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start); +int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start); +int dns_packet_read_name(DnsPacket *p, char **ret, bool allow_compression, size_t *start); +int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start); +int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_flush, size_t *start); + +void dns_packet_rewind(DnsPacket *p, size_t idx); + +int dns_packet_skip_question(DnsPacket *p); +int dns_packet_extract(DnsPacket *p); + +static inline bool DNS_PACKET_SHALL_CACHE(DnsPacket *p) { + /* Never cache data originating from localhost, under the + * assumption, that it's coming from a locally DNS forwarder + * or server, that is caching on its own. */ + + return in_addr_is_localhost(p->family, &p->sender) == 0; +} + +/* https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-6 */ +enum { + DNS_RCODE_SUCCESS = 0, + DNS_RCODE_FORMERR = 1, + DNS_RCODE_SERVFAIL = 2, + DNS_RCODE_NXDOMAIN = 3, + DNS_RCODE_NOTIMP = 4, + DNS_RCODE_REFUSED = 5, + DNS_RCODE_YXDOMAIN = 6, + DNS_RCODE_YXRRSET = 7, + DNS_RCODE_NXRRSET = 8, + DNS_RCODE_NOTAUTH = 9, + DNS_RCODE_NOTZONE = 10, + DNS_RCODE_BADVERS = 16, + DNS_RCODE_BADSIG = 16, /* duplicate value! */ + DNS_RCODE_BADKEY = 17, + DNS_RCODE_BADTIME = 18, + DNS_RCODE_BADMODE = 19, + DNS_RCODE_BADNAME = 20, + DNS_RCODE_BADALG = 21, + DNS_RCODE_BADTRUNC = 22, + DNS_RCODE_BADCOOKIE = 23, + _DNS_RCODE_MAX_DEFINED, + _DNS_RCODE_MAX = 4095 /* 4 bit rcode in the header plus 8 bit rcode in OPT, makes 12 bit */ +}; + +const char* dns_rcode_to_string(int i) _const_; +int dns_rcode_from_string(const char *s) _pure_; + +const char* dns_protocol_to_string(DnsProtocol p) _const_; +DnsProtocol dns_protocol_from_string(const char *s) _pure_; + +#define LLMNR_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 252U) }) +#define LLMNR_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x03 } }) + +#define MDNS_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 251U) }) +#define MDNS_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfb } }) + +static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family, bool authenticated) { + uint64_t f; + + /* Converts a protocol + family into a flags field as used in queries and responses */ + + f = authenticated ? SD_RESOLVED_AUTHENTICATED : 0; + + switch (protocol) { + case DNS_PROTOCOL_DNS: + return f|SD_RESOLVED_DNS; + + case DNS_PROTOCOL_LLMNR: + return f|(family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4); + + case DNS_PROTOCOL_MDNS: + return f|(family == AF_INET6 ? SD_RESOLVED_MDNS_IPV6 : SD_RESOLVED_MDNS_IPV4); + + default: + return f; + } +} diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-question.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-question.h new file mode 100644 index 0000000000..fb1b2d2410 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-question.h @@ -0,0 +1,74 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/macro.h" + +typedef struct DnsQuestion DnsQuestion; + +#include "resolved-dns-rr.h" + +/* A simple array of resource keys */ + +struct DnsQuestion { + unsigned n_ref; + unsigned n_keys, n_allocated; + DnsResourceKey* keys[0]; +}; + +DnsQuestion *dns_question_new(unsigned n); +DnsQuestion *dns_question_ref(DnsQuestion *q); +DnsQuestion *dns_question_unref(DnsQuestion *q); + +int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna); +int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a); +int dns_question_new_service(DnsQuestion **ret, const char *service, const char *type, const char *domain, bool with_txt, bool convert_idna); + +int dns_question_add(DnsQuestion *q, DnsResourceKey *key); + +int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain); +int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char* search_domain); +int dns_question_is_valid_for_query(DnsQuestion *q); +int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k); +int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b); + +int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret); + +const char *dns_question_first_name(DnsQuestion *q); + +static inline unsigned dns_question_size(DnsQuestion *q) { + return q ? q->n_keys : 0; +} + +static inline bool dns_question_isempty(DnsQuestion *q) { + return dns_question_size(q) <= 0; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuestion*, dns_question_unref); + +#define _DNS_QUESTION_FOREACH(u, key, q) \ + for (unsigned UNIQ_T(i, u) = ({ \ + (key) = ((q) && (q)->n_keys > 0) ? (q)->keys[0] : NULL; \ + 0; \ + }); \ + (q) && (UNIQ_T(i, u) < (q)->n_keys); \ + UNIQ_T(i, u)++, (key) = (UNIQ_T(i, u) < (q)->n_keys ? (q)->keys[UNIQ_T(i, u)] : NULL)) + +#define DNS_QUESTION_FOREACH(key, q) _DNS_QUESTION_FOREACH(UNIQ, key, q) diff --git a/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-rr.h b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-rr.h new file mode 100644 index 0000000000..864c7c237f --- /dev/null +++ b/src/grp-resolve/libbasic-dns/include/basic-dns/resolved-dns-rr.h @@ -0,0 +1,354 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <netinet/in.h> + +#include "systemd-basic/bitmap.h" +#include "systemd-basic/hashmap.h" +#include "systemd-basic/in-addr-util.h" +#include "systemd-basic/list.h" +#include "systemd-basic/string-util.h" + +#include "dns-type.h" + +typedef struct DnsResourceKey DnsResourceKey; +typedef struct DnsResourceRecord DnsResourceRecord; +typedef struct DnsTxtItem DnsTxtItem; + +/* DNSKEY RR flags */ +#define DNSKEY_FLAG_SEP (UINT16_C(1) << 0) +#define DNSKEY_FLAG_REVOKE (UINT16_C(1) << 7) +#define DNSKEY_FLAG_ZONE_KEY (UINT16_C(1) << 8) + +/* mDNS RR flags */ +#define MDNS_RR_CACHE_FLUSH (UINT16_C(1) << 15) + +/* DNSSEC algorithm identifiers, see + * http://tools.ietf.org/html/rfc4034#appendix-A.1 and + * https://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ +enum { + DNSSEC_ALGORITHM_RSAMD5 = 1, + DNSSEC_ALGORITHM_DH, + DNSSEC_ALGORITHM_DSA, + DNSSEC_ALGORITHM_ECC, + DNSSEC_ALGORITHM_RSASHA1, + DNSSEC_ALGORITHM_DSA_NSEC3_SHA1, + DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1, + DNSSEC_ALGORITHM_RSASHA256 = 8, /* RFC 5702 */ + DNSSEC_ALGORITHM_RSASHA512 = 10, /* RFC 5702 */ + DNSSEC_ALGORITHM_ECC_GOST = 12, /* RFC 5933 */ + DNSSEC_ALGORITHM_ECDSAP256SHA256 = 13, /* RFC 6605 */ + DNSSEC_ALGORITHM_ECDSAP384SHA384 = 14, /* RFC 6605 */ + DNSSEC_ALGORITHM_INDIRECT = 252, + DNSSEC_ALGORITHM_PRIVATEDNS, + DNSSEC_ALGORITHM_PRIVATEOID, + _DNSSEC_ALGORITHM_MAX_DEFINED +}; + +/* DNSSEC digest identifiers, see + * https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ +enum { + DNSSEC_DIGEST_SHA1 = 1, + DNSSEC_DIGEST_SHA256 = 2, /* RFC 4509 */ + DNSSEC_DIGEST_GOST_R_34_11_94 = 3, /* RFC 5933 */ + DNSSEC_DIGEST_SHA384 = 4, /* RFC 6605 */ + _DNSSEC_DIGEST_MAX_DEFINED +}; + +/* DNSSEC NSEC3 hash algorithms, see + * https://www.iana.org/assignments/dnssec-nsec3-parameters/dnssec-nsec3-parameters.xhtml */ +enum { + NSEC3_ALGORITHM_SHA1 = 1, + _NSEC3_ALGORITHM_MAX_DEFINED +}; + +struct DnsResourceKey { + unsigned n_ref; /* (unsigned -1) for const keys, see below */ + uint16_t class, type; + char *_name; /* don't access directly, use dns_resource_key_name()! */ +}; + +/* Creates a temporary resource key. This is only useful to quickly + * look up something, without allocating a full DnsResourceKey object + * for it. Note that it is not OK to take references to this kind of + * resource key object. */ +#define DNS_RESOURCE_KEY_CONST(c, t, n) \ + ((DnsResourceKey) { \ + .n_ref = (unsigned) -1, \ + .class = c, \ + .type = t, \ + ._name = (char*) n, \ + }) + + +struct DnsTxtItem { + size_t length; + LIST_FIELDS(DnsTxtItem, items); + uint8_t data[]; +}; + +struct DnsResourceRecord { + unsigned n_ref; + DnsResourceKey *key; + + char *to_string; + + uint32_t ttl; + usec_t expiry; /* RRSIG signature expiry */ + + /* How many labels to strip to determine "signer" of the RRSIG (aka, the zone). -1 if not signed. */ + unsigned n_skip_labels_signer; + /* How many labels to strip to determine "synthesizing source" of this RR, i.e. the wildcard's immediate parent. -1 if not signed. */ + unsigned n_skip_labels_source; + + bool unparseable:1; + + bool wire_format_canonical:1; + void *wire_format; + size_t wire_format_size; + size_t wire_format_rdata_offset; + + union { + struct { + void *data; + size_t data_size; + } generic, opt; + + struct { + uint16_t priority; + uint16_t weight; + uint16_t port; + char *name; + } srv; + + struct { + char *name; + } ptr, ns, cname, dname; + + struct { + char *cpu; + char *os; + } hinfo; + + struct { + DnsTxtItem *items; + } txt, spf; + + struct { + struct in_addr in_addr; + } a; + + struct { + struct in6_addr in6_addr; + } aaaa; + + struct { + char *mname; + char *rname; + uint32_t serial; + uint32_t refresh; + uint32_t retry; + uint32_t expire; + uint32_t minimum; + } soa; + + struct { + uint16_t priority; + char *exchange; + } mx; + + /* https://tools.ietf.org/html/rfc1876 */ + struct { + uint8_t version; + uint8_t size; + uint8_t horiz_pre; + uint8_t vert_pre; + uint32_t latitude; + uint32_t longitude; + uint32_t altitude; + } loc; + + /* https://tools.ietf.org/html/rfc4255#section-3.1 */ + struct { + uint8_t algorithm; + uint8_t fptype; + void *fingerprint; + size_t fingerprint_size; + } sshfp; + + /* http://tools.ietf.org/html/rfc4034#section-2.1 */ + struct { + uint16_t flags; + uint8_t protocol; + uint8_t algorithm; + void* key; + size_t key_size; + } dnskey; + + /* http://tools.ietf.org/html/rfc4034#section-3.1 */ + struct { + uint16_t type_covered; + uint8_t algorithm; + uint8_t labels; + uint32_t original_ttl; + uint32_t expiration; + uint32_t inception; + uint16_t key_tag; + char *signer; + void *signature; + size_t signature_size; + } rrsig; + + /* https://tools.ietf.org/html/rfc4034#section-4.1 */ + struct { + char *next_domain_name; + Bitmap *types; + } nsec; + + /* https://tools.ietf.org/html/rfc4034#section-5.1 */ + struct { + uint16_t key_tag; + uint8_t algorithm; + uint8_t digest_type; + void *digest; + size_t digest_size; + } ds; + + struct { + uint8_t algorithm; + uint8_t flags; + uint16_t iterations; + void *salt; + size_t salt_size; + void *next_hashed_name; + size_t next_hashed_name_size; + Bitmap *types; + } nsec3; + + /* https://tools.ietf.org/html/draft-ietf-dane-protocol-23 */ + struct { + uint8_t cert_usage; + uint8_t selector; + uint8_t matching_type; + void *data; + size_t data_size; + } tlsa; + + /* https://tools.ietf.org/html/rfc6844 */ + struct { + uint8_t flags; + char *tag; + void *value; + size_t value_size; + } caa; + }; +}; + +static inline const void* DNS_RESOURCE_RECORD_RDATA(DnsResourceRecord *rr) { + if (!rr) + return NULL; + + if (!rr->wire_format) + return NULL; + + assert(rr->wire_format_rdata_offset <= rr->wire_format_size); + return (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset; +} + +static inline size_t DNS_RESOURCE_RECORD_RDATA_SIZE(DnsResourceRecord *rr) { + if (!rr) + return 0; + if (!rr->wire_format) + return 0; + + assert(rr->wire_format_rdata_offset <= rr->wire_format_size); + return rr->wire_format_size - rr->wire_format_rdata_offset; +} + +static inline uint8_t DNS_RESOURCE_RECORD_OPT_VERSION_SUPPORTED(DnsResourceRecord *rr) { + assert(rr); + assert(rr->key->type == DNS_TYPE_OPT); + + return ((rr->ttl >> 16) & 0xFF) == 0; +} + +DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name); +DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname); +int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name); +DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name); +DnsResourceKey* dns_resource_key_ref(DnsResourceKey *key); +DnsResourceKey* dns_resource_key_unref(DnsResourceKey *key); +const char* dns_resource_key_name(const DnsResourceKey *key); +bool dns_resource_key_is_address(const DnsResourceKey *key); +int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b); +int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain); +int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain); +int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa); + +/* _DNS_{CLASS,TYPE}_STRING_MAX include one byte for NUL, which we use for space instead below. + * DNS_HOSTNAME_MAX does not include the NUL byte, so we need to add 1. */ +#define DNS_RESOURCE_KEY_STRING_MAX (_DNS_CLASS_STRING_MAX + _DNS_TYPE_STRING_MAX + DNS_HOSTNAME_MAX + 1) + +char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size); +ssize_t dns_resource_record_payload(DnsResourceRecord *rr, void **out); + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref); + +static inline bool dns_key_is_shared(const DnsResourceKey *key) { + return IN_SET(key->type, DNS_TYPE_PTR); +} + +bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b); + +DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key); +DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name); +DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr); +DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr); +int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name); +int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name); +int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b); +const char* dns_resource_record_to_string(DnsResourceRecord *rr); +DnsResourceRecord *dns_resource_record_copy(DnsResourceRecord *rr); +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref); + +int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical); + +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone); +int dns_resource_record_is_synthetic(DnsResourceRecord *rr); + +int dns_resource_record_clamp_ttl(DnsResourceRecord **rr, uint32_t max_ttl); + +DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i); +bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b); +DnsTxtItem *dns_txt_item_copy(DnsTxtItem *i); + +void dns_resource_record_hash_func(const void *i, struct siphash *state); + +extern const struct hash_ops dns_resource_key_hash_ops; +extern const struct hash_ops dns_resource_record_hash_ops; + +int dnssec_algorithm_to_string_alloc(int i, char **ret); +int dnssec_algorithm_from_string(const char *s) _pure_; + +int dnssec_digest_to_string_alloc(int i, char **ret); +int dnssec_digest_from_string(const char *s) _pure_; diff --git a/src/grp-resolve/libbasic-dns/src/GNUmakefile b/src/grp-resolve/libbasic-dns/src/GNUmakefile new file mode 120000 index 0000000000..13308a50cd --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/GNUmakefile @@ -0,0 +1 @@ +../../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/libbasic-dns/src/Makefile b/src/grp-resolve/libbasic-dns/src/Makefile new file mode 100644 index 0000000000..d7f12fafd4 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/Makefile @@ -0,0 +1,52 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +$(outdir)/dns_type-list.txt: src/resolve/dns-type.h + $(AM_V_GEN)$(SED) -n -r 's/.* DNS_TYPE_(\w+).*/\1/p' <$< >$@ + +$(outdir)/dns_type-to-name.h: src/resolve/dns_type-list.txt + $(AM_V_GEN)$(AWK) 'BEGIN{ print "const char *dns_type_to_string(int type) {\n\tswitch(type) {" } {printf " case DNS_TYPE_%s: return ", $$1; sub(/_/, "-"); printf "\"%s\";\n", $$1 } END{ print " default: return NULL;\n\t}\n}\n" }' <$< >$@ + +$(outdir)/dns_type-from-name.gperf: src/resolve/dns_type-list.txt + $(AM_V_GEN)$(AWK) 'BEGIN{ print "struct dns_type_name { const char* name; int id; };"; print "%null-strings"; print "%%";} { s=$$1; sub(/_/, "-", s); printf "%s, ", $$s; printf "DNS_TYPE_%s\n", $$1 }' <$< >$@ + +basic_dns_sources = \ + src/resolve/resolved-dns-dnssec.c \ + src/resolve/resolved-dns-dnssec.h \ + src/resolve/resolved-dns-packet.c \ + src/resolve/resolved-dns-packet.h \ + src/resolve/resolved-dns-rr.c \ + src/resolve/resolved-dns-rr.h \ + src/resolve/resolved-dns-answer.c \ + src/resolve/resolved-dns-answer.h \ + src/resolve/resolved-dns-question.c \ + src/resolve/resolved-dns-question.h \ + src/resolve/dns-type.c \ + src/resolve/dns-type.h + +gperf_txt_sources += \ + src/resolve/dns_type-list.txt + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/libbasic-dns/src/dns-type.c b/src/grp-resolve/libbasic-dns/src/dns-type.c new file mode 100644 index 0000000000..f7acfa9e6f --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/dns-type.c @@ -0,0 +1,332 @@ +/*** + This file is part of systemd. + + Copyright 2014 Zbigniew Jędrzejewski-Szmek + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <sys/socket.h> + +#include "basic-dns/dns-type.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/string-util.h" + +typedef const struct { + uint16_t type; + const char *name; +} dns_type; + +static const struct dns_type_name * +lookup_dns_type (register const char *str, register GPERF_LEN_TYPE len); + +#include "dns_type-from-name.h" +#include "dns_type-to-name.h" + +int dns_type_from_string(const char *s) { + const struct dns_type_name *sc; + + assert(s); + + sc = lookup_dns_type(s, strlen(s)); + if (sc) + return sc->id; + + s = startswith_no_case(s, "TYPE"); + if (s) { + unsigned x; + + if (safe_atou(s, &x) >= 0 && + x <= UINT16_MAX) + return (int) x; + } + + return _DNS_TYPE_INVALID; +} + +bool dns_type_is_pseudo(uint16_t type) { + + /* Checks whether the specified type is a "pseudo-type". What + * a "pseudo-type" precisely is, is defined only very weakly, + * but apparently entails all RR types that are not actually + * stored as RRs on the server and should hence also not be + * cached. We use this list primarily to validate NSEC type + * bitfields, and to verify what to cache. */ + + return IN_SET(type, + 0, /* A Pseudo RR type, according to RFC 2931 */ + DNS_TYPE_ANY, + DNS_TYPE_AXFR, + DNS_TYPE_IXFR, + DNS_TYPE_OPT, + DNS_TYPE_TSIG, + DNS_TYPE_TKEY + ); +} + +bool dns_class_is_pseudo(uint16_t class) { + return class == DNS_TYPE_ANY; +} + +bool dns_type_is_valid_query(uint16_t type) { + + /* The types valid as questions in packets */ + + return !IN_SET(type, + 0, + DNS_TYPE_OPT, + DNS_TYPE_TSIG, + DNS_TYPE_TKEY, + + /* RRSIG are technically valid as questions, but we refuse doing explicit queries for them, as + * they aren't really payload, but signatures for payload, and cannot be validated on their + * own. After all they are the signatures, and have no signatures of their own validating + * them. */ + DNS_TYPE_RRSIG); +} + +bool dns_type_is_zone_transer(uint16_t type) { + + /* Zone transfers, either normal or incremental */ + + return IN_SET(type, + DNS_TYPE_AXFR, + DNS_TYPE_IXFR); +} + +bool dns_type_is_valid_rr(uint16_t type) { + + /* The types valid as RR in packets (but not necessarily + * stored on servers). */ + + return !IN_SET(type, + DNS_TYPE_ANY, + DNS_TYPE_AXFR, + DNS_TYPE_IXFR); +} + +bool dns_class_is_valid_rr(uint16_t class) { + return class != DNS_CLASS_ANY; +} + +bool dns_type_may_redirect(uint16_t type) { + /* The following record types should never be redirected using + * CNAME/DNAME RRs. See + * <https://tools.ietf.org/html/rfc4035#section-2.5>. */ + + if (dns_type_is_pseudo(type)) + return false; + + return !IN_SET(type, + DNS_TYPE_CNAME, + DNS_TYPE_DNAME, + DNS_TYPE_NSEC3, + DNS_TYPE_NSEC, + DNS_TYPE_RRSIG, + DNS_TYPE_NXT, + DNS_TYPE_SIG, + DNS_TYPE_KEY); +} + +bool dns_type_may_wildcard(uint16_t type) { + + /* The following records may not be expanded from wildcard RRsets */ + + if (dns_type_is_pseudo(type)) + return false; + + return !IN_SET(type, + DNS_TYPE_NSEC3, + DNS_TYPE_SOA, + + /* Prohibited by https://tools.ietf.org/html/rfc4592#section-4.4 */ + DNS_TYPE_DNAME); +} + +bool dns_type_apex_only(uint16_t type) { + + /* Returns true for all RR types that may only appear signed in a zone apex */ + + return IN_SET(type, + DNS_TYPE_SOA, + DNS_TYPE_NS, /* this one can appear elsewhere, too, but not signed */ + DNS_TYPE_DNSKEY, + DNS_TYPE_NSEC3PARAM); +} + +bool dns_type_is_dnssec(uint16_t type) { + return IN_SET(type, + DNS_TYPE_DS, + DNS_TYPE_DNSKEY, + DNS_TYPE_RRSIG, + DNS_TYPE_NSEC, + DNS_TYPE_NSEC3, + DNS_TYPE_NSEC3PARAM); +} + +bool dns_type_is_obsolete(uint16_t type) { + return IN_SET(type, + /* Obsoleted by RFC 973 */ + DNS_TYPE_MD, + DNS_TYPE_MF, + DNS_TYPE_MAILA, + + /* Kinda obsoleted by RFC 2505 */ + DNS_TYPE_MB, + DNS_TYPE_MG, + DNS_TYPE_MR, + DNS_TYPE_MINFO, + DNS_TYPE_MAILB, + + /* RFC1127 kinda obsoleted this by recommending against its use */ + DNS_TYPE_WKS, + + /* Declared historical by RFC 6563 */ + DNS_TYPE_A6, + + /* Obsoleted by DNSSEC-bis */ + DNS_TYPE_NXT, + + /* RFC 1035 removed support for concepts that needed this from RFC 883 */ + DNS_TYPE_NULL); +} + +bool dns_type_needs_authentication(uint16_t type) { + + /* Returns true for all (non-obsolete) RR types where records are not useful if they aren't + * authenticated. I.e. everything that contains crypto keys. */ + + return IN_SET(type, + DNS_TYPE_CERT, + DNS_TYPE_SSHFP, + DNS_TYPE_IPSECKEY, + DNS_TYPE_DS, + DNS_TYPE_DNSKEY, + DNS_TYPE_TLSA, + DNS_TYPE_CDNSKEY, + DNS_TYPE_OPENPGPKEY, + DNS_TYPE_CAA); +} + +int dns_type_to_af(uint16_t t) { + switch (t) { + + case DNS_TYPE_A: + return AF_INET; + + case DNS_TYPE_AAAA: + return AF_INET6; + + case DNS_TYPE_ANY: + return AF_UNSPEC; + + default: + return -EINVAL; + } +} + +const char *dns_class_to_string(uint16_t class) { + + switch (class) { + + case DNS_CLASS_IN: + return "IN"; + + case DNS_CLASS_ANY: + return "ANY"; + } + + return NULL; +} + +int dns_class_from_string(const char *s) { + + if (!s) + return _DNS_CLASS_INVALID; + + if (strcaseeq(s, "IN")) + return DNS_CLASS_IN; + else if (strcaseeq(s, "ANY")) + return DNS_CLASS_ANY; + + return _DNS_CLASS_INVALID; +} + +const char* tlsa_cert_usage_to_string(uint8_t cert_usage) { + + switch (cert_usage) { + + case 0: + return "CA constraint"; + + case 1: + return "Service certificate constraint"; + + case 2: + return "Trust anchor assertion"; + + case 3: + return "Domain-issued certificate"; + + case 4 ... 254: + return "Unassigned"; + + case 255: + return "Private use"; + } + + return NULL; /* clang cannot count that we covered everything */ +} + +const char* tlsa_selector_to_string(uint8_t selector) { + switch (selector) { + + case 0: + return "Full Certificate"; + + case 1: + return "SubjectPublicKeyInfo"; + + case 2 ... 254: + return "Unassigned"; + + case 255: + return "Private use"; + } + + return NULL; +} + +const char* tlsa_matching_type_to_string(uint8_t selector) { + + switch (selector) { + + case 0: + return "No hash used"; + + case 1: + return "SHA-256"; + + case 2: + return "SHA-512"; + + case 3 ... 254: + return "Unassigned"; + + case 255: + return "Private use"; + } + + return NULL; +} diff --git a/src/grp-resolve/libbasic-dns/src/resolved-dns-answer.c b/src/grp-resolve/libbasic-dns/src/resolved-dns-answer.c new file mode 100644 index 0000000000..afb0d3cafa --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-answer.c @@ -0,0 +1,858 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-dnssec.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-shared/dns-domain.h" + +DnsAnswer *dns_answer_new(unsigned n) { + DnsAnswer *a; + + a = malloc0(offsetof(DnsAnswer, items) + sizeof(DnsAnswerItem) * n); + if (!a) + return NULL; + + a->n_ref = 1; + a->n_allocated = n; + + return a; +} + +DnsAnswer *dns_answer_ref(DnsAnswer *a) { + if (!a) + return NULL; + + assert(a->n_ref > 0); + a->n_ref++; + return a; +} + +static void dns_answer_flush(DnsAnswer *a) { + DnsResourceRecord *rr; + + if (!a) + return; + + DNS_ANSWER_FOREACH(rr, a) + dns_resource_record_unref(rr); + + a->n_rrs = 0; +} + +DnsAnswer *dns_answer_unref(DnsAnswer *a) { + if (!a) + return NULL; + + assert(a->n_ref > 0); + + if (a->n_ref == 1) { + dns_answer_flush(a); + free(a); + } else + a->n_ref--; + + return NULL; +} + +static int dns_answer_add_raw(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags) { + assert(rr); + + if (!a) + return -ENOSPC; + + if (a->n_rrs >= a->n_allocated) + return -ENOSPC; + + a->items[a->n_rrs++] = (DnsAnswerItem) { + .rr = dns_resource_record_ref(rr), + .ifindex = ifindex, + .flags = flags, + }; + + return 1; +} + +static int dns_answer_add_raw_all(DnsAnswer *a, DnsAnswer *source) { + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int ifindex, r; + + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, source) { + r = dns_answer_add_raw(a, rr, ifindex, flags); + if (r < 0) + return r; + } + + return 0; +} + +int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags) { + unsigned i; + int r; + + assert(rr); + + if (!a) + return -ENOSPC; + if (a->n_ref > 1) + return -EBUSY; + + for (i = 0; i < a->n_rrs; i++) { + if (a->items[i].ifindex != ifindex) + continue; + + r = dns_resource_record_equal(a->items[i].rr, rr); + if (r < 0) + return r; + if (r > 0) { + /* Don't mix contradicting TTLs (see below) */ + if ((rr->ttl == 0) != (a->items[i].rr->ttl == 0)) + return -EINVAL; + + /* Entry already exists, keep the entry with + * the higher RR. */ + if (rr->ttl > a->items[i].rr->ttl) { + dns_resource_record_ref(rr); + dns_resource_record_unref(a->items[i].rr); + a->items[i].rr = rr; + } + + a->items[i].flags |= flags; + return 0; + } + + r = dns_resource_key_equal(a->items[i].rr->key, rr->key); + if (r < 0) + return r; + if (r > 0) { + /* There's already an RR of the same RRset in + * place! Let's see if the TTLs more or less + * match. We don't really care if they match + * precisely, but we do care whether one is 0 + * and the other is not. See RFC 2181, Section + * 5.2.*/ + + if ((rr->ttl == 0) != (a->items[i].rr->ttl == 0)) + return -EINVAL; + } + } + + return dns_answer_add_raw(a, rr, ifindex, flags); +} + +static int dns_answer_add_all(DnsAnswer *a, DnsAnswer *b) { + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int ifindex, r; + + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, b) { + r = dns_answer_add(a, rr, ifindex, flags); + if (r < 0) + return r; + } + + return 0; +} + +int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags) { + int r; + + assert(a); + assert(rr); + + r = dns_answer_reserve_or_clone(a, 1); + if (r < 0) + return r; + + return dns_answer_add(*a, rr, ifindex, flags); +} + +int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl, int ifindex) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *soa = NULL; + + soa = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SOA, name); + if (!soa) + return -ENOMEM; + + soa->ttl = ttl; + + soa->soa.mname = strdup(name); + if (!soa->soa.mname) + return -ENOMEM; + + soa->soa.rname = strappend("root.", name); + if (!soa->soa.rname) + return -ENOMEM; + + soa->soa.serial = 1; + soa->soa.refresh = 1; + soa->soa.retry = 1; + soa->soa.expire = 1; + soa->soa.minimum = ttl; + + return dns_answer_add(a, soa, ifindex, DNS_ANSWER_AUTHENTICATED); +} + +int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *ret_flags) { + DnsAnswerFlags flags = 0, i_flags; + DnsResourceRecord *i; + bool found = false; + int r; + + assert(key); + + DNS_ANSWER_FOREACH_FLAGS(i, i_flags, a) { + r = dns_resource_key_match_rr(key, i, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + if (!ret_flags) + return 1; + + if (found) + flags &= i_flags; + else { + flags = i_flags; + found = true; + } + } + + if (ret_flags) + *ret_flags = flags; + + return found; +} + +int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *ret_flags) { + DnsAnswerFlags flags = 0, i_flags; + DnsResourceRecord *i; + bool found = false; + int r; + + assert(rr); + + DNS_ANSWER_FOREACH_FLAGS(i, i_flags, a) { + r = dns_resource_record_equal(i, rr); + if (r < 0) + return r; + if (r == 0) + continue; + + if (!ret_flags) + return 1; + + if (found) + flags &= i_flags; + else { + flags = i_flags; + found = true; + } + } + + if (ret_flags) + *ret_flags = flags; + + return found; +} + +int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *ret_flags) { + DnsAnswerFlags flags = 0, i_flags; + DnsResourceRecord *i; + bool found = false; + int r; + + assert(key); + + DNS_ANSWER_FOREACH_FLAGS(i, i_flags, a) { + r = dns_resource_key_equal(i->key, key); + if (r < 0) + return r; + if (r == 0) + continue; + + if (!ret_flags) + return true; + + if (found) + flags &= i_flags; + else { + flags = i_flags; + found = true; + } + } + + if (ret_flags) + *ret_flags = flags; + + return found; +} + +int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a) { + DnsResourceRecord *i; + + DNS_ANSWER_FOREACH(i, a) { + if (IN_SET(i->key->type, DNS_TYPE_NSEC, DNS_TYPE_NSEC3)) + return true; + } + + return false; +} + +int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone) { + DnsResourceRecord *rr; + int r; + + /* Checks whether the specified answer contains at least one NSEC3 RR in the specified zone */ + + DNS_ANSWER_FOREACH(rr, answer) { + const char *p; + + if (rr->key->type != DNS_TYPE_NSEC3) + continue; + + p = dns_resource_key_name(rr->key); + r = dns_name_parent(&p); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_name_equal(p, zone); + if (r != 0) + return r; + } + + return false; +} + +int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags) { + DnsResourceRecord *rr, *soa = NULL; + DnsAnswerFlags rr_flags, soa_flags = 0; + int r; + + assert(key); + + /* For a SOA record we can never find a matching SOA record */ + if (key->type == DNS_TYPE_SOA) + return 0; + + DNS_ANSWER_FOREACH_FLAGS(rr, rr_flags, a) { + r = dns_resource_key_match_soa(key, rr->key); + if (r < 0) + return r; + if (r > 0) { + + if (soa) { + r = dns_name_endswith(dns_resource_key_name(rr->key), dns_resource_key_name(soa->key)); + if (r < 0) + return r; + if (r > 0) + continue; + } + + soa = rr; + soa_flags = rr_flags; + } + } + + if (!soa) + return 0; + + if (ret) + *ret = soa; + if (flags) + *flags = soa_flags; + + return 1; +} + +int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags) { + DnsResourceRecord *rr; + DnsAnswerFlags rr_flags; + int r; + + assert(key); + + /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */ + if (!dns_type_may_redirect(key->type)) + return 0; + + DNS_ANSWER_FOREACH_FLAGS(rr, rr_flags, a) { + r = dns_resource_key_match_cname_or_dname(key, rr->key, NULL); + if (r < 0) + return r; + if (r > 0) { + if (ret) + *ret = rr; + if (flags) + *flags = rr_flags; + return 1; + } + } + + return 0; +} + +int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret) { + _cleanup_(dns_answer_unrefp) DnsAnswer *k = NULL; + int r; + + assert(ret); + + if (dns_answer_size(a) <= 0) { + *ret = dns_answer_ref(b); + return 0; + } + + if (dns_answer_size(b) <= 0) { + *ret = dns_answer_ref(a); + return 0; + } + + k = dns_answer_new(a->n_rrs + b->n_rrs); + if (!k) + return -ENOMEM; + + r = dns_answer_add_raw_all(k, a); + if (r < 0) + return r; + + r = dns_answer_add_all(k, b); + if (r < 0) + return r; + + *ret = k; + k = NULL; + + return 0; +} + +int dns_answer_extend(DnsAnswer **a, DnsAnswer *b) { + DnsAnswer *merged; + int r; + + assert(a); + + r = dns_answer_merge(*a, b, &merged); + if (r < 0) + return r; + + dns_answer_unref(*a); + *a = merged; + + return 0; +} + +int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key) { + bool found = false, other = false; + DnsResourceRecord *rr; + unsigned i; + int r; + + assert(a); + assert(key); + + /* Remove all entries matching the specified key from *a */ + + DNS_ANSWER_FOREACH(rr, *a) { + r = dns_resource_key_equal(rr->key, key); + if (r < 0) + return r; + if (r > 0) + found = true; + else + other = true; + + if (found && other) + break; + } + + if (!found) + return 0; + + if (!other) { + *a = dns_answer_unref(*a); /* Return NULL for the empty answer */ + return 1; + } + + if ((*a)->n_ref > 1) { + _cleanup_(dns_answer_unrefp) DnsAnswer *copy = NULL; + DnsAnswerFlags flags; + int ifindex; + + copy = dns_answer_new((*a)->n_rrs); + if (!copy) + return -ENOMEM; + + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, *a) { + r = dns_resource_key_equal(rr->key, key); + if (r < 0) + return r; + if (r > 0) + continue; + + r = dns_answer_add_raw(copy, rr, ifindex, flags); + if (r < 0) + return r; + } + + dns_answer_unref(*a); + *a = copy; + copy = NULL; + + return 1; + } + + /* Only a single reference, edit in-place */ + + i = 0; + for (;;) { + if (i >= (*a)->n_rrs) + break; + + r = dns_resource_key_equal((*a)->items[i].rr->key, key); + if (r < 0) + return r; + if (r > 0) { + /* Kill this entry */ + + dns_resource_record_unref((*a)->items[i].rr); + memmove((*a)->items + i, (*a)->items + i + 1, sizeof(DnsAnswerItem) * ((*a)->n_rrs - i - 1)); + (*a)->n_rrs--; + continue; + + } else + /* Keep this entry */ + i++; + } + + return 1; +} + +int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rm) { + bool found = false, other = false; + DnsResourceRecord *rr; + unsigned i; + int r; + + assert(a); + assert(rm); + + /* Remove all entries matching the specified RR from *a */ + + DNS_ANSWER_FOREACH(rr, *a) { + r = dns_resource_record_equal(rr, rm); + if (r < 0) + return r; + if (r > 0) + found = true; + else + other = true; + + if (found && other) + break; + } + + if (!found) + return 0; + + if (!other) { + *a = dns_answer_unref(*a); /* Return NULL for the empty answer */ + return 1; + } + + if ((*a)->n_ref > 1) { + _cleanup_(dns_answer_unrefp) DnsAnswer *copy = NULL; + DnsAnswerFlags flags; + int ifindex; + + copy = dns_answer_new((*a)->n_rrs); + if (!copy) + return -ENOMEM; + + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, *a) { + r = dns_resource_record_equal(rr, rm); + if (r < 0) + return r; + if (r > 0) + continue; + + r = dns_answer_add_raw(copy, rr, ifindex, flags); + if (r < 0) + return r; + } + + dns_answer_unref(*a); + *a = copy; + copy = NULL; + + return 1; + } + + /* Only a single reference, edit in-place */ + + i = 0; + for (;;) { + if (i >= (*a)->n_rrs) + break; + + r = dns_resource_record_equal((*a)->items[i].rr, rm); + if (r < 0) + return r; + if (r > 0) { + /* Kill this entry */ + + dns_resource_record_unref((*a)->items[i].rr); + memmove((*a)->items + i, (*a)->items + i + 1, sizeof(DnsAnswerItem) * ((*a)->n_rrs - i - 1)); + (*a)->n_rrs--; + continue; + + } else + /* Keep this entry */ + i++; + } + + return 1; +} + +int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags) { + DnsResourceRecord *rr_source; + int ifindex_source, r; + DnsAnswerFlags flags_source; + + assert(a); + assert(key); + + /* Copy all RRs matching the specified key from source into *a */ + + DNS_ANSWER_FOREACH_FULL(rr_source, ifindex_source, flags_source, source) { + + r = dns_resource_key_equal(rr_source->key, key); + if (r < 0) + return r; + if (r == 0) + continue; + + /* Make space for at least one entry */ + r = dns_answer_reserve_or_clone(a, 1); + if (r < 0) + return r; + + r = dns_answer_add(*a, rr_source, ifindex_source, flags_source|or_flags); + if (r < 0) + return r; + } + + return 0; +} + +int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags) { + int r; + + assert(to); + assert(from); + assert(key); + + r = dns_answer_copy_by_key(to, *from, key, or_flags); + if (r < 0) + return r; + + return dns_answer_remove_by_key(from, key); +} + +void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) { + DnsAnswerItem *items; + unsigned i, start, end; + + if (!a) + return; + + if (a->n_rrs <= 1) + return; + + start = 0; + end = a->n_rrs-1; + + /* RFC 4795, Section 2.6 suggests we should order entries + * depending on whether the sender is a link-local address. */ + + items = newa(DnsAnswerItem, a->n_rrs); + for (i = 0; i < a->n_rrs; i++) { + + if (a->items[i].rr->key->class == DNS_CLASS_IN && + ((a->items[i].rr->key->type == DNS_TYPE_A && in_addr_is_link_local(AF_INET, (union in_addr_union*) &a->items[i].rr->a.in_addr) != prefer_link_local) || + (a->items[i].rr->key->type == DNS_TYPE_AAAA && in_addr_is_link_local(AF_INET6, (union in_addr_union*) &a->items[i].rr->aaaa.in6_addr) != prefer_link_local))) + /* Order address records that are not preferred to the end of the array */ + items[end--] = a->items[i]; + else + /* Order all other records to the beginning of the array */ + items[start++] = a->items[i]; + } + + assert(start == end+1); + memcpy(a->items, items, sizeof(DnsAnswerItem) * a->n_rrs); +} + +int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { + DnsAnswer *n; + + assert(a); + + if (n_free <= 0) + return 0; + + if (*a) { + unsigned ns; + + if ((*a)->n_ref > 1) + return -EBUSY; + + ns = (*a)->n_rrs + n_free; + + if ((*a)->n_allocated >= ns) + return 0; + + /* Allocate more than we need */ + ns *= 2; + + n = realloc(*a, offsetof(DnsAnswer, items) + sizeof(DnsAnswerItem) * ns); + if (!n) + return -ENOMEM; + + n->n_allocated = ns; + } else { + n = dns_answer_new(n_free); + if (!n) + return -ENOMEM; + } + + *a = n; + return 0; +} + +int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free) { + _cleanup_(dns_answer_unrefp) DnsAnswer *n = NULL; + int r; + + assert(a); + + /* Tries to extend the DnsAnswer object. And if that's not + * possible, since we are not the sole owner, then allocate a + * new, appropriately sized one. Either way, after this call + * the object will only have a single reference, and has room + * for at least the specified number of RRs. */ + + r = dns_answer_reserve(a, n_free); + if (r != -EBUSY) + return r; + + assert(*a); + + n = dns_answer_new(((*a)->n_rrs + n_free) * 2); + if (!n) + return -ENOMEM; + + r = dns_answer_add_raw_all(n, *a); + if (r < 0) + return r; + + dns_answer_unref(*a); + *a = n; + n = NULL; + + return 0; +} + +void dns_answer_dump(DnsAnswer *answer, FILE *f) { + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int ifindex; + + if (!f) + f = stdout; + + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, answer) { + const char *t; + + fputc('\t', f); + + t = dns_resource_record_to_string(rr); + if (!t) { + log_oom(); + continue; + } + + fputs(t, f); + + if (ifindex != 0 || flags & (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE|DNS_ANSWER_SHARED_OWNER)) + fputs("\t;", f); + + if (ifindex != 0) + printf(" ifindex=%i", ifindex); + if (flags & DNS_ANSWER_AUTHENTICATED) + fputs(" authenticated", f); + if (flags & DNS_ANSWER_CACHEABLE) + fputs(" cachable", f); + if (flags & DNS_ANSWER_SHARED_OWNER) + fputs(" shared-owner", f); + + fputc('\n', f); + } +} + +bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname) { + DnsResourceRecord *rr; + int r; + + assert(cname); + + /* Checks whether the answer contains a DNAME record that indicates that the specified CNAME record is + * synthesized from it */ + + if (cname->key->type != DNS_TYPE_CNAME) + return 0; + + DNS_ANSWER_FOREACH(rr, a) { + _cleanup_free_ char *n = NULL; + + if (rr->key->type != DNS_TYPE_DNAME) + continue; + if (rr->key->class != cname->key->class) + continue; + + r = dns_name_change_suffix(cname->cname.name, rr->dname.name, dns_resource_key_name(rr->key), &n); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_name_equal(n, dns_resource_key_name(cname->key)); + if (r < 0) + return r; + if (r > 0) + return 1; + + } + + return 0; +} diff --git a/src/grp-resolve/libbasic-dns/src/resolved-dns-dnssec.c b/src/grp-resolve/libbasic-dns/src/resolved-dns-dnssec.c new file mode 100644 index 0000000000..9f56ce0843 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-dnssec.c @@ -0,0 +1,2199 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#ifdef HAVE_GCRYPT +#include <gcrypt.h> +#endif + +#include "basic-dns/resolved-dns-dnssec.h" +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/hexdecoct.h" +#include "systemd-basic/string-table.h" +#include "systemd-gcrypt/gcrypt-util.h" +#include "systemd-shared/dns-domain.h" + +#define VERIFY_RRS_MAX 256 +#define MAX_KEY_SIZE (32*1024) + +/* Permit a maximum clock skew of 1h 10min. This should be enough to deal with DST confusion */ +#define SKEW_MAX (1*USEC_PER_HOUR + 10*USEC_PER_MINUTE) + +/* Maximum number of NSEC3 iterations we'll do. RFC5155 says 2500 shall be the maximum useful value */ +#define NSEC3_ITERATIONS_MAX 2500 + +/* + * The DNSSEC Chain of trust: + * + * Normal RRs are protected via RRSIG RRs in combination with DNSKEY RRs, all in the same zone + * DNSKEY RRs are either protected like normal RRs, or via a DS from a zone "higher" up the tree + * DS RRs are protected like normal RRs + * + * Example chain: + * Normal RR → RRSIG/DNSKEY+ → DS → RRSIG/DNSKEY+ → DS → ... → DS → RRSIG/DNSKEY+ → DS + */ + +uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke) { + const uint8_t *p; + uint32_t sum, f; + size_t i; + + /* The algorithm from RFC 4034, Appendix B. */ + + assert(dnskey); + assert(dnskey->key->type == DNS_TYPE_DNSKEY); + + f = (uint32_t) dnskey->dnskey.flags; + + if (mask_revoke) + f &= ~DNSKEY_FLAG_REVOKE; + + sum = f + ((((uint32_t) dnskey->dnskey.protocol) << 8) + (uint32_t) dnskey->dnskey.algorithm); + + p = dnskey->dnskey.key; + + for (i = 0; i < dnskey->dnskey.key_size; i++) + sum += (i & 1) == 0 ? (uint32_t) p[i] << 8 : (uint32_t) p[i]; + + sum += (sum >> 16) & UINT32_C(0xFFFF); + + return sum & UINT32_C(0xFFFF); +} + +int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max) { + size_t c = 0; + int r; + + /* Converts the specified hostname into DNSSEC canonicalized + * form. */ + + if (buffer_max < 2) + return -ENOBUFS; + + for (;;) { + r = dns_label_unescape(&n, buffer, buffer_max); + if (r < 0) + return r; + if (r == 0) + break; + + if (buffer_max < (size_t) r + 2) + return -ENOBUFS; + + /* The DNSSEC canonical form is not clear on what to + * do with dots appearing in labels, the way DNS-SD + * does it. Refuse it for now. */ + + if (memchr(buffer, '.', r)) + return -EINVAL; + + ascii_strlower_n(buffer, (size_t) r); + buffer[r] = '.'; + + buffer += r + 1; + c += r + 1; + + buffer_max -= r + 1; + } + + if (c <= 0) { + /* Not even a single label: this is the root domain name */ + + assert(buffer_max > 2); + buffer[0] = '.'; + buffer[1] = 0; + + return 1; + } + + return (int) c; +} + +#ifdef HAVE_GCRYPT + +static int rr_compare(const void *a, const void *b) { + DnsResourceRecord **x = (DnsResourceRecord**) a, **y = (DnsResourceRecord**) b; + size_t m; + int r; + + /* Let's order the RRs according to RFC 4034, Section 6.3 */ + + assert(x); + assert(*x); + assert((*x)->wire_format); + assert(y); + assert(*y); + assert((*y)->wire_format); + + m = MIN(DNS_RESOURCE_RECORD_RDATA_SIZE(*x), DNS_RESOURCE_RECORD_RDATA_SIZE(*y)); + + r = memcmp(DNS_RESOURCE_RECORD_RDATA(*x), DNS_RESOURCE_RECORD_RDATA(*y), m); + if (r != 0) + return r; + + if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) < DNS_RESOURCE_RECORD_RDATA_SIZE(*y)) + return -1; + else if (DNS_RESOURCE_RECORD_RDATA_SIZE(*x) > DNS_RESOURCE_RECORD_RDATA_SIZE(*y)) + return 1; + + return 0; +} + +static int dnssec_rsa_verify_raw( + const char *hash_algorithm, + const void *signature, size_t signature_size, + const void *data, size_t data_size, + const void *exponent, size_t exponent_size, + const void *modulus, size_t modulus_size) { + + gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL; + gcry_mpi_t n = NULL, e = NULL, s = NULL; + gcry_error_t ge; + int r; + + assert(hash_algorithm); + + ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature, signature_size, NULL); + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_mpi_scan(&e, GCRYMPI_FMT_USG, exponent, exponent_size, NULL); + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_mpi_scan(&n, GCRYMPI_FMT_USG, modulus, modulus_size, NULL); + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&signature_sexp, + NULL, + "(sig-val (rsa (s %m)))", + s); + + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&data_sexp, + NULL, + "(data (flags pkcs1) (hash %s %b))", + hash_algorithm, + (int) data_size, + data); + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&public_key_sexp, + NULL, + "(public-key (rsa (n %m) (e %m)))", + n, + e); + if (ge != 0) { + r = -EIO; + goto finish; + } + + ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp); + if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE) + r = 0; + else if (ge != 0) { + log_debug("RSA signature check failed: %s", gpg_strerror(ge)); + r = -EIO; + } else + r = 1; + +finish: + if (e) + gcry_mpi_release(e); + if (n) + gcry_mpi_release(n); + if (s) + gcry_mpi_release(s); + + if (public_key_sexp) + gcry_sexp_release(public_key_sexp); + if (signature_sexp) + gcry_sexp_release(signature_sexp); + if (data_sexp) + gcry_sexp_release(data_sexp); + + return r; +} + +static int dnssec_rsa_verify( + const char *hash_algorithm, + const void *hash, size_t hash_size, + DnsResourceRecord *rrsig, + DnsResourceRecord *dnskey) { + + size_t exponent_size, modulus_size; + void *exponent, *modulus; + + assert(hash_algorithm); + assert(hash); + assert(hash_size > 0); + assert(rrsig); + assert(dnskey); + + if (*(uint8_t*) dnskey->dnskey.key == 0) { + /* exponent is > 255 bytes long */ + + exponent = (uint8_t*) dnskey->dnskey.key + 3; + exponent_size = + ((size_t) (((uint8_t*) dnskey->dnskey.key)[1]) << 8) | + ((size_t) ((uint8_t*) dnskey->dnskey.key)[2]); + + if (exponent_size < 256) + return -EINVAL; + + if (3 + exponent_size >= dnskey->dnskey.key_size) + return -EINVAL; + + modulus = (uint8_t*) dnskey->dnskey.key + 3 + exponent_size; + modulus_size = dnskey->dnskey.key_size - 3 - exponent_size; + + } else { + /* exponent is <= 255 bytes long */ + + exponent = (uint8_t*) dnskey->dnskey.key + 1; + exponent_size = (size_t) ((uint8_t*) dnskey->dnskey.key)[0]; + + if (exponent_size <= 0) + return -EINVAL; + + if (1 + exponent_size >= dnskey->dnskey.key_size) + return -EINVAL; + + modulus = (uint8_t*) dnskey->dnskey.key + 1 + exponent_size; + modulus_size = dnskey->dnskey.key_size - 1 - exponent_size; + } + + return dnssec_rsa_verify_raw( + hash_algorithm, + rrsig->rrsig.signature, rrsig->rrsig.signature_size, + hash, hash_size, + exponent, exponent_size, + modulus, modulus_size); +} + +static int dnssec_ecdsa_verify_raw( + const char *hash_algorithm, + const char *curve, + const void *signature_r, size_t signature_r_size, + const void *signature_s, size_t signature_s_size, + const void *data, size_t data_size, + const void *key, size_t key_size) { + + gcry_sexp_t public_key_sexp = NULL, data_sexp = NULL, signature_sexp = NULL; + gcry_mpi_t q = NULL, r = NULL, s = NULL; + gcry_error_t ge; + int k; + + assert(hash_algorithm); + + ge = gcry_mpi_scan(&r, GCRYMPI_FMT_USG, signature_r, signature_r_size, NULL); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_mpi_scan(&s, GCRYMPI_FMT_USG, signature_s, signature_s_size, NULL); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_mpi_scan(&q, GCRYMPI_FMT_USG, key, key_size, NULL); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&signature_sexp, + NULL, + "(sig-val (ecdsa (r %m) (s %m)))", + r, + s); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&data_sexp, + NULL, + "(data (flags rfc6979) (hash %s %b))", + hash_algorithm, + (int) data_size, + data); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_sexp_build(&public_key_sexp, + NULL, + "(public-key (ecc (curve %s) (q %m)))", + curve, + q); + if (ge != 0) { + k = -EIO; + goto finish; + } + + ge = gcry_pk_verify(signature_sexp, data_sexp, public_key_sexp); + if (gpg_err_code(ge) == GPG_ERR_BAD_SIGNATURE) + k = 0; + else if (ge != 0) { + log_debug("ECDSA signature check failed: %s", gpg_strerror(ge)); + k = -EIO; + } else + k = 1; +finish: + if (r) + gcry_mpi_release(r); + if (s) + gcry_mpi_release(s); + if (q) + gcry_mpi_release(q); + + if (public_key_sexp) + gcry_sexp_release(public_key_sexp); + if (signature_sexp) + gcry_sexp_release(signature_sexp); + if (data_sexp) + gcry_sexp_release(data_sexp); + + return k; +} + +static int dnssec_ecdsa_verify( + const char *hash_algorithm, + int algorithm, + const void *hash, size_t hash_size, + DnsResourceRecord *rrsig, + DnsResourceRecord *dnskey) { + + const char *curve; + size_t key_size; + uint8_t *q; + + assert(hash); + assert(hash_size); + assert(rrsig); + assert(dnskey); + + if (algorithm == DNSSEC_ALGORITHM_ECDSAP256SHA256) { + key_size = 32; + curve = "NIST P-256"; + } else if (algorithm == DNSSEC_ALGORITHM_ECDSAP384SHA384) { + key_size = 48; + curve = "NIST P-384"; + } else + return -EOPNOTSUPP; + + if (dnskey->dnskey.key_size != key_size * 2) + return -EINVAL; + + if (rrsig->rrsig.signature_size != key_size * 2) + return -EINVAL; + + q = alloca(key_size*2 + 1); + q[0] = 0x04; /* Prepend 0x04 to indicate an uncompressed key */ + memcpy(q+1, dnskey->dnskey.key, key_size*2); + + return dnssec_ecdsa_verify_raw( + hash_algorithm, + curve, + rrsig->rrsig.signature, key_size, + (uint8_t*) rrsig->rrsig.signature + key_size, key_size, + hash, hash_size, + q, key_size*2+1); +} + +static void md_add_uint8(gcry_md_hd_t md, uint8_t v) { + gcry_md_write(md, &v, sizeof(v)); +} + +static void md_add_uint16(gcry_md_hd_t md, uint16_t v) { + v = htobe16(v); + gcry_md_write(md, &v, sizeof(v)); +} + +static void md_add_uint32(gcry_md_hd_t md, uint32_t v) { + v = htobe32(v); + gcry_md_write(md, &v, sizeof(v)); +} + +static int dnssec_rrsig_prepare(DnsResourceRecord *rrsig) { + int n_key_labels, n_signer_labels; + const char *name; + int r; + + /* Checks whether the specified RRSIG RR is somewhat valid, and initializes the .n_skip_labels_source and + * .n_skip_labels_signer fields so that we can use them later on. */ + + assert(rrsig); + assert(rrsig->key->type == DNS_TYPE_RRSIG); + + /* Check if this RRSIG RR is already prepared */ + if (rrsig->n_skip_labels_source != (unsigned) -1) + return 0; + + if (rrsig->rrsig.inception > rrsig->rrsig.expiration) + return -EINVAL; + + name = dns_resource_key_name(rrsig->key); + + n_key_labels = dns_name_count_labels(name); + if (n_key_labels < 0) + return n_key_labels; + if (rrsig->rrsig.labels > n_key_labels) + return -EINVAL; + + n_signer_labels = dns_name_count_labels(rrsig->rrsig.signer); + if (n_signer_labels < 0) + return n_signer_labels; + if (n_signer_labels > rrsig->rrsig.labels) + return -EINVAL; + + r = dns_name_skip(name, n_key_labels - n_signer_labels, &name); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + /* Check if the signer is really a suffix of us */ + r = dns_name_equal(name, rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + rrsig->n_skip_labels_source = n_key_labels - rrsig->rrsig.labels; + rrsig->n_skip_labels_signer = n_key_labels - n_signer_labels; + + return 0; +} + +static int dnssec_rrsig_expired(DnsResourceRecord *rrsig, usec_t realtime) { + usec_t expiration, inception, skew; + + assert(rrsig); + assert(rrsig->key->type == DNS_TYPE_RRSIG); + + if (realtime == USEC_INFINITY) + realtime = now(CLOCK_REALTIME); + + expiration = rrsig->rrsig.expiration * USEC_PER_SEC; + inception = rrsig->rrsig.inception * USEC_PER_SEC; + + /* Consider inverted validity intervals as expired */ + if (inception > expiration) + return true; + + /* Permit a certain amount of clock skew of 10% of the valid + * time range. This takes inspiration from unbound's + * resolver. */ + skew = (expiration - inception) / 10; + if (skew > SKEW_MAX) + skew = SKEW_MAX; + + if (inception < skew) + inception = 0; + else + inception -= skew; + + if (expiration + skew < expiration) + expiration = USEC_INFINITY; + else + expiration += skew; + + return realtime < inception || realtime > expiration; +} + +static int algorithm_to_gcrypt_md(uint8_t algorithm) { + + /* Translates a DNSSEC signature algorithm into a gcrypt + * digest identifier. + * + * Note that we implement all algorithms listed as "Must + * implement" and "Recommended to Implement" in RFC6944. We + * don't implement any algorithms that are listed as + * "Optional" or "Must Not Implement". Specifically, we do not + * implement RSAMD5, DSASHA1, DH, DSA-NSEC3-SHA1, and + * GOST-ECC. */ + + switch (algorithm) { + + case DNSSEC_ALGORITHM_RSASHA1: + case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1: + return GCRY_MD_SHA1; + + case DNSSEC_ALGORITHM_RSASHA256: + case DNSSEC_ALGORITHM_ECDSAP256SHA256: + return GCRY_MD_SHA256; + + case DNSSEC_ALGORITHM_ECDSAP384SHA384: + return GCRY_MD_SHA384; + + case DNSSEC_ALGORITHM_RSASHA512: + return GCRY_MD_SHA512; + + default: + return -EOPNOTSUPP; + } +} + +static void dnssec_fix_rrset_ttl( + DnsResourceRecord *list[], + unsigned n, + DnsResourceRecord *rrsig, + usec_t realtime) { + + unsigned k; + + assert(list); + assert(n > 0); + assert(rrsig); + + for (k = 0; k < n; k++) { + DnsResourceRecord *rr = list[k]; + + /* Pick the TTL as the minimum of the RR's TTL, the + * RR's original TTL according to the RRSIG and the + * RRSIG's own TTL, see RFC 4035, Section 5.3.3 */ + rr->ttl = MIN3(rr->ttl, rrsig->rrsig.original_ttl, rrsig->ttl); + rr->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; + + /* Copy over information about the signer and wildcard source of synthesis */ + rr->n_skip_labels_source = rrsig->n_skip_labels_source; + rr->n_skip_labels_signer = rrsig->n_skip_labels_signer; + } + + rrsig->expiry = rrsig->rrsig.expiration * USEC_PER_SEC; +} + +int dnssec_verify_rrset( + DnsAnswer *a, + const DnsResourceKey *key, + DnsResourceRecord *rrsig, + DnsResourceRecord *dnskey, + usec_t realtime, + DnssecResult *result) { + + uint8_t wire_format_name[DNS_WIRE_FOMAT_HOSTNAME_MAX]; + DnsResourceRecord **list, *rr; + const char *source, *name; + gcry_md_hd_t md = NULL; + int r, md_algorithm; + size_t k, n = 0; + size_t hash_size; + void *hash; + bool wildcard; + + assert(key); + assert(rrsig); + assert(dnskey); + assert(result); + assert(rrsig->key->type == DNS_TYPE_RRSIG); + assert(dnskey->key->type == DNS_TYPE_DNSKEY); + + /* Verifies that the RRSet matches the specified "key" in "a", + * using the signature "rrsig" and the key "dnskey". It's + * assumed that RRSIG and DNSKEY match. */ + + md_algorithm = algorithm_to_gcrypt_md(rrsig->rrsig.algorithm); + if (md_algorithm == -EOPNOTSUPP) { + *result = DNSSEC_UNSUPPORTED_ALGORITHM; + return 0; + } + if (md_algorithm < 0) + return md_algorithm; + + r = dnssec_rrsig_prepare(rrsig); + if (r == -EINVAL) { + *result = DNSSEC_INVALID; + return r; + } + if (r < 0) + return r; + + r = dnssec_rrsig_expired(rrsig, realtime); + if (r < 0) + return r; + if (r > 0) { + *result = DNSSEC_SIGNATURE_EXPIRED; + return 0; + } + + name = dns_resource_key_name(key); + + /* Some keys may only appear signed in the zone apex, and are invalid anywhere else. (SOA, NS...) */ + if (dns_type_apex_only(rrsig->rrsig.type_covered)) { + r = dns_name_equal(rrsig->rrsig.signer, name); + if (r < 0) + return r; + if (r == 0) { + *result = DNSSEC_INVALID; + return 0; + } + } + + /* OTOH DS RRs may not appear in the zone apex, but are valid everywhere else. */ + if (rrsig->rrsig.type_covered == DNS_TYPE_DS) { + r = dns_name_equal(rrsig->rrsig.signer, name); + if (r < 0) + return r; + if (r > 0) { + *result = DNSSEC_INVALID; + return 0; + } + } + + /* Determine the "Source of Synthesis" and whether this is a wildcard RRSIG */ + r = dns_name_suffix(name, rrsig->rrsig.labels, &source); + if (r < 0) + return r; + if (r > 0 && !dns_type_may_wildcard(rrsig->rrsig.type_covered)) { + /* We refuse to validate NSEC3 or SOA RRs that are synthesized from wildcards */ + *result = DNSSEC_INVALID; + return 0; + } + if (r == 1) { + /* If we stripped a single label, then let's see if that maybe was "*". If so, we are not really + * synthesized from a wildcard, we are the wildcard itself. Treat that like a normal name. */ + r = dns_name_startswith(name, "*"); + if (r < 0) + return r; + if (r > 0) + source = name; + + wildcard = r == 0; + } else + wildcard = r > 0; + + /* Collect all relevant RRs in a single array, so that we can look at the RRset */ + list = newa(DnsResourceRecord *, dns_answer_size(a)); + + DNS_ANSWER_FOREACH(rr, a) { + r = dns_resource_key_equal(key, rr->key); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We need the wire format for ordering, and digest calculation */ + r = dns_resource_record_to_wire_format(rr, true); + if (r < 0) + return r; + + list[n++] = rr; + + if (n > VERIFY_RRS_MAX) + return -E2BIG; + } + + if (n <= 0) + return -ENODATA; + + /* Bring the RRs into canonical order */ + qsort_safe(list, n, sizeof(DnsResourceRecord*), rr_compare); + + /* OK, the RRs are now in canonical order. Let's calculate the digest */ + initialize_libgcrypt(false); + + hash_size = gcry_md_get_algo_dlen(md_algorithm); + assert(hash_size > 0); + + gcry_md_open(&md, md_algorithm, 0); + if (!md) + return -EIO; + + md_add_uint16(md, rrsig->rrsig.type_covered); + md_add_uint8(md, rrsig->rrsig.algorithm); + md_add_uint8(md, rrsig->rrsig.labels); + md_add_uint32(md, rrsig->rrsig.original_ttl); + md_add_uint32(md, rrsig->rrsig.expiration); + md_add_uint32(md, rrsig->rrsig.inception); + md_add_uint16(md, rrsig->rrsig.key_tag); + + r = dns_name_to_wire_format(rrsig->rrsig.signer, wire_format_name, sizeof(wire_format_name), true); + if (r < 0) + goto finish; + gcry_md_write(md, wire_format_name, r); + + /* Convert the source of synthesis into wire format */ + r = dns_name_to_wire_format(source, wire_format_name, sizeof(wire_format_name), true); + if (r < 0) + goto finish; + + for (k = 0; k < n; k++) { + size_t l; + + rr = list[k]; + + /* Hash the source of synthesis. If this is a wildcard, then prefix it with the *. label */ + if (wildcard) + gcry_md_write(md, (uint8_t[]) { 1, '*'}, 2); + gcry_md_write(md, wire_format_name, r); + + md_add_uint16(md, rr->key->type); + md_add_uint16(md, rr->key->class); + md_add_uint32(md, rrsig->rrsig.original_ttl); + + l = DNS_RESOURCE_RECORD_RDATA_SIZE(rr); + assert(l <= 0xFFFF); + + md_add_uint16(md, (uint16_t) l); + gcry_md_write(md, DNS_RESOURCE_RECORD_RDATA(rr), l); + } + + hash = gcry_md_read(md, 0); + if (!hash) { + r = -EIO; + goto finish; + } + + switch (rrsig->rrsig.algorithm) { + + case DNSSEC_ALGORITHM_RSASHA1: + case DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1: + case DNSSEC_ALGORITHM_RSASHA256: + case DNSSEC_ALGORITHM_RSASHA512: + r = dnssec_rsa_verify( + gcry_md_algo_name(md_algorithm), + hash, hash_size, + rrsig, + dnskey); + break; + + case DNSSEC_ALGORITHM_ECDSAP256SHA256: + case DNSSEC_ALGORITHM_ECDSAP384SHA384: + r = dnssec_ecdsa_verify( + gcry_md_algo_name(md_algorithm), + rrsig->rrsig.algorithm, + hash, hash_size, + rrsig, + dnskey); + break; + } + + if (r < 0) + goto finish; + + /* Now, fix the ttl, expiry, and remember the synthesizing source and the signer */ + if (r > 0) + dnssec_fix_rrset_ttl(list, n, rrsig, realtime); + + if (r == 0) + *result = DNSSEC_INVALID; + else if (wildcard) + *result = DNSSEC_VALIDATED_WILDCARD; + else + *result = DNSSEC_VALIDATED; + + r = 0; + +finish: + gcry_md_close(md); + return r; +} + +int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) { + + assert(rrsig); + assert(dnskey); + + /* Checks if the specified DNSKEY RR matches the key used for + * the signature in the specified RRSIG RR */ + + if (rrsig->key->type != DNS_TYPE_RRSIG) + return -EINVAL; + + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return 0; + if (dnskey->key->class != rrsig->key->class) + return 0; + if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0) + return 0; + if (!revoked_ok && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE)) + return 0; + if (dnskey->dnskey.protocol != 3) + return 0; + if (dnskey->dnskey.algorithm != rrsig->rrsig.algorithm) + return 0; + + if (dnssec_keytag(dnskey, false) != rrsig->rrsig.key_tag) + return 0; + + return dns_name_equal(dns_resource_key_name(dnskey->key), rrsig->rrsig.signer); +} + +int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) { + assert(key); + assert(rrsig); + + /* Checks if the specified RRSIG RR protects the RRSet of the specified RR key. */ + + if (rrsig->key->type != DNS_TYPE_RRSIG) + return 0; + if (rrsig->key->class != key->class) + return 0; + if (rrsig->rrsig.type_covered != key->type) + return 0; + + return dns_name_equal(dns_resource_key_name(rrsig->key), dns_resource_key_name(key)); +} + +int dnssec_verify_rrset_search( + DnsAnswer *a, + const DnsResourceKey *key, + DnsAnswer *validated_dnskeys, + usec_t realtime, + DnssecResult *result, + DnsResourceRecord **ret_rrsig) { + + bool found_rrsig = false, found_invalid = false, found_expired_rrsig = false, found_unsupported_algorithm = false; + DnsResourceRecord *rrsig; + int r; + + assert(key); + assert(result); + + /* Verifies all RRs from "a" that match the key "key" against DNSKEYs in "validated_dnskeys" */ + + if (!a || a->n_rrs <= 0) + return -ENODATA; + + /* Iterate through each RRSIG RR. */ + DNS_ANSWER_FOREACH(rrsig, a) { + DnsResourceRecord *dnskey; + DnsAnswerFlags flags; + + /* Is this an RRSIG RR that applies to RRs matching our key? */ + r = dnssec_key_match_rrsig(key, rrsig); + if (r < 0) + return r; + if (r == 0) + continue; + + found_rrsig = true; + + /* Look for a matching key */ + DNS_ANSWER_FOREACH_FLAGS(dnskey, flags, validated_dnskeys) { + DnssecResult one_result; + + if ((flags & DNS_ANSWER_AUTHENTICATED) == 0) + continue; + + /* Is this a DNSKEY RR that matches they key of our RRSIG? */ + r = dnssec_rrsig_match_dnskey(rrsig, dnskey, false); + if (r < 0) + return r; + if (r == 0) + continue; + + /* Take the time here, if it isn't set yet, so + * that we do all validations with the same + * time. */ + if (realtime == USEC_INFINITY) + realtime = now(CLOCK_REALTIME); + + /* Yay, we found a matching RRSIG with a matching + * DNSKEY, awesome. Now let's verify all entries of + * the RRSet against the RRSIG and DNSKEY + * combination. */ + + r = dnssec_verify_rrset(a, key, rrsig, dnskey, realtime, &one_result); + if (r < 0) + return r; + + switch (one_result) { + + case DNSSEC_VALIDATED: + case DNSSEC_VALIDATED_WILDCARD: + /* Yay, the RR has been validated, + * return immediately, but fix up the expiry */ + if (ret_rrsig) + *ret_rrsig = rrsig; + + *result = one_result; + return 0; + + case DNSSEC_INVALID: + /* If the signature is invalid, let's try another + key and/or signature. After all they + key_tags and stuff are not unique, and + might be shared by multiple keys. */ + found_invalid = true; + continue; + + case DNSSEC_UNSUPPORTED_ALGORITHM: + /* If the key algorithm is + unsupported, try another + RRSIG/DNSKEY pair, but remember we + encountered this, so that we can + return a proper error when we + encounter nothing better. */ + found_unsupported_algorithm = true; + continue; + + case DNSSEC_SIGNATURE_EXPIRED: + /* If the signature is expired, try + another one, but remember it, so + that we can return this */ + found_expired_rrsig = true; + continue; + + default: + assert_not_reached("Unexpected DNSSEC validation result"); + } + } + } + + if (found_expired_rrsig) + *result = DNSSEC_SIGNATURE_EXPIRED; + else if (found_unsupported_algorithm) + *result = DNSSEC_UNSUPPORTED_ALGORITHM; + else if (found_invalid) + *result = DNSSEC_INVALID; + else if (found_rrsig) + *result = DNSSEC_MISSING_KEY; + else + *result = DNSSEC_NO_SIGNATURE; + + if (ret_rrsig) + *ret_rrsig = NULL; + + return 0; +} + +int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) { + DnsResourceRecord *rr; + int r; + + /* Checks whether there's at least one RRSIG in 'a' that proctects RRs of the specified key */ + + DNS_ANSWER_FOREACH(rr, a) { + r = dnssec_key_match_rrsig(key, rr); + if (r < 0) + return r; + if (r > 0) + return 1; + } + + return 0; +} + +static int digest_to_gcrypt_md(uint8_t algorithm) { + + /* Translates a DNSSEC digest algorithm into a gcrypt digest identifier */ + + switch (algorithm) { + + case DNSSEC_DIGEST_SHA1: + return GCRY_MD_SHA1; + + case DNSSEC_DIGEST_SHA256: + return GCRY_MD_SHA256; + + case DNSSEC_DIGEST_SHA384: + return GCRY_MD_SHA384; + + default: + return -EOPNOTSUPP; + } +} + +int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) { + char owner_name[DNSSEC_CANONICAL_HOSTNAME_MAX]; + gcry_md_hd_t md = NULL; + size_t hash_size; + int md_algorithm, r; + void *result; + + assert(dnskey); + assert(ds); + + /* Implements DNSKEY verification by a DS, according to RFC 4035, section 5.2 */ + + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return -EINVAL; + if (ds->key->type != DNS_TYPE_DS) + return -EINVAL; + if ((dnskey->dnskey.flags & DNSKEY_FLAG_ZONE_KEY) == 0) + return -EKEYREJECTED; + if (!mask_revoke && (dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE)) + return -EKEYREJECTED; + if (dnskey->dnskey.protocol != 3) + return -EKEYREJECTED; + + if (dnskey->dnskey.algorithm != ds->ds.algorithm) + return 0; + if (dnssec_keytag(dnskey, mask_revoke) != ds->ds.key_tag) + return 0; + + initialize_libgcrypt(false); + + md_algorithm = digest_to_gcrypt_md(ds->ds.digest_type); + if (md_algorithm < 0) + return md_algorithm; + + hash_size = gcry_md_get_algo_dlen(md_algorithm); + assert(hash_size > 0); + + if (ds->ds.digest_size != hash_size) + return 0; + + r = dnssec_canonicalize(dns_resource_key_name(dnskey->key), owner_name, sizeof(owner_name)); + if (r < 0) + return r; + + gcry_md_open(&md, md_algorithm, 0); + if (!md) + return -EIO; + + gcry_md_write(md, owner_name, r); + if (mask_revoke) + md_add_uint16(md, dnskey->dnskey.flags & ~DNSKEY_FLAG_REVOKE); + else + md_add_uint16(md, dnskey->dnskey.flags); + md_add_uint8(md, dnskey->dnskey.protocol); + md_add_uint8(md, dnskey->dnskey.algorithm); + gcry_md_write(md, dnskey->dnskey.key, dnskey->dnskey.key_size); + + result = gcry_md_read(md, 0); + if (!result) { + r = -EIO; + goto finish; + } + + r = memcmp(result, ds->ds.digest, ds->ds.digest_size) != 0; + +finish: + gcry_md_close(md); + return r; +} + +int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) { + DnsResourceRecord *ds; + DnsAnswerFlags flags; + int r; + + assert(dnskey); + + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return 0; + + DNS_ANSWER_FOREACH_FLAGS(ds, flags, validated_ds) { + + if ((flags & DNS_ANSWER_AUTHENTICATED) == 0) + continue; + + if (ds->key->type != DNS_TYPE_DS) + continue; + if (ds->key->class != dnskey->key->class) + continue; + + r = dns_name_equal(dns_resource_key_name(dnskey->key), dns_resource_key_name(ds->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_verify_dnskey_by_ds(dnskey, ds, false); + if (IN_SET(r, -EKEYREJECTED, -EOPNOTSUPP)) + return 0; /* The DNSKEY is revoked or otherwise invalid, or we don't support the digest algorithm */ + if (r < 0) + return r; + if (r > 0) + return 1; + } + + return 0; +} + +static int nsec3_hash_to_gcrypt_md(uint8_t algorithm) { + + /* Translates a DNSSEC NSEC3 hash algorithm into a gcrypt digest identifier */ + + switch (algorithm) { + + case NSEC3_ALGORITHM_SHA1: + return GCRY_MD_SHA1; + + default: + return -EOPNOTSUPP; + } +} + +int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) { + uint8_t wire_format[DNS_WIRE_FOMAT_HOSTNAME_MAX]; + gcry_md_hd_t md = NULL; + size_t hash_size; + int algorithm; + void *result; + unsigned k; + int r; + + assert(nsec3); + assert(name); + assert(ret); + + if (nsec3->key->type != DNS_TYPE_NSEC3) + return -EINVAL; + + if (nsec3->nsec3.iterations > NSEC3_ITERATIONS_MAX) { + log_debug("Ignoring NSEC3 RR %s with excessive number of iterations.", dns_resource_record_to_string(nsec3)); + return -EOPNOTSUPP; + } + + algorithm = nsec3_hash_to_gcrypt_md(nsec3->nsec3.algorithm); + if (algorithm < 0) + return algorithm; + + initialize_libgcrypt(false); + + hash_size = gcry_md_get_algo_dlen(algorithm); + assert(hash_size > 0); + + if (nsec3->nsec3.next_hashed_name_size != hash_size) + return -EINVAL; + + r = dns_name_to_wire_format(name, wire_format, sizeof(wire_format), true); + if (r < 0) + return r; + + gcry_md_open(&md, algorithm, 0); + if (!md) + return -EIO; + + gcry_md_write(md, wire_format, r); + gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size); + + result = gcry_md_read(md, 0); + if (!result) { + r = -EIO; + goto finish; + } + + for (k = 0; k < nsec3->nsec3.iterations; k++) { + uint8_t tmp[hash_size]; + memcpy(tmp, result, hash_size); + + gcry_md_reset(md); + gcry_md_write(md, tmp, hash_size); + gcry_md_write(md, nsec3->nsec3.salt, nsec3->nsec3.salt_size); + + result = gcry_md_read(md, 0); + if (!result) { + r = -EIO; + goto finish; + } + } + + memcpy(ret, result, hash_size); + r = (int) hash_size; + +finish: + gcry_md_close(md); + return r; +} + +static int nsec3_is_good(DnsResourceRecord *rr, DnsResourceRecord *nsec3) { + const char *a, *b; + int r; + + assert(rr); + + if (rr->key->type != DNS_TYPE_NSEC3) + return 0; + + /* RFC 5155, Section 8.2 says we MUST ignore NSEC3 RRs with flags != 0 or 1 */ + if (!IN_SET(rr->nsec3.flags, 0, 1)) + return 0; + + /* Ignore NSEC3 RRs whose algorithm we don't know */ + if (nsec3_hash_to_gcrypt_md(rr->nsec3.algorithm) < 0) + return 0; + /* Ignore NSEC3 RRs with an excessive number of required iterations */ + if (rr->nsec3.iterations > NSEC3_ITERATIONS_MAX) + return 0; + + /* Ignore NSEC3 RRs generated from wildcards. If these NSEC3 RRs weren't correctly signed we can't make this + * check (since rr->n_skip_labels_source is -1), but that's OK, as we won't trust them anyway in that case. */ + if (rr->n_skip_labels_source != 0 && rr->n_skip_labels_source != (unsigned) -1) + return 0; + /* Ignore NSEC3 RRs that are located anywhere else than one label below the zone */ + if (rr->n_skip_labels_signer != 1 && rr->n_skip_labels_signer != (unsigned) -1) + return 0; + + if (!nsec3) + return 1; + + /* If a second NSEC3 RR is specified, also check if they are from the same zone. */ + + if (nsec3 == rr) /* Shortcut */ + return 1; + + if (rr->key->class != nsec3->key->class) + return 0; + if (rr->nsec3.algorithm != nsec3->nsec3.algorithm) + return 0; + if (rr->nsec3.iterations != nsec3->nsec3.iterations) + return 0; + if (rr->nsec3.salt_size != nsec3->nsec3.salt_size) + return 0; + if (memcmp(rr->nsec3.salt, nsec3->nsec3.salt, rr->nsec3.salt_size) != 0) + return 0; + + a = dns_resource_key_name(rr->key); + r = dns_name_parent(&a); /* strip off hash */ + if (r < 0) + return r; + if (r == 0) + return 0; + + b = dns_resource_key_name(nsec3->key); + r = dns_name_parent(&b); /* strip off hash */ + if (r < 0) + return r; + if (r == 0) + return 0; + + /* Make sure both have the same parent */ + return dns_name_equal(a, b); +} + +static int nsec3_hashed_domain_format(const uint8_t *hashed, size_t hashed_size, const char *zone, char **ret) { + _cleanup_free_ char *l = NULL; + char *j; + + assert(hashed); + assert(hashed_size > 0); + assert(zone); + assert(ret); + + l = base32hexmem(hashed, hashed_size, false); + if (!l) + return -ENOMEM; + + j = strjoin(l, ".", zone, NULL); + if (!j) + return -ENOMEM; + + *ret = j; + return (int) hashed_size; +} + +static int nsec3_hashed_domain_make(DnsResourceRecord *nsec3, const char *domain, const char *zone, char **ret) { + uint8_t hashed[DNSSEC_HASH_SIZE_MAX]; + int hashed_size; + + assert(nsec3); + assert(domain); + assert(zone); + assert(ret); + + hashed_size = dnssec_nsec3_hash(nsec3, domain, hashed); + if (hashed_size < 0) + return hashed_size; + + return nsec3_hashed_domain_format(hashed, (size_t) hashed_size, zone, ret); +} + +/* See RFC 5155, Section 8 + * First try to find a NSEC3 record that matches our query precisely, if that fails, find the closest + * enclosure. Secondly, find a proof that there is no closer enclosure and either a proof that there + * is no wildcard domain as a direct descendant of the closest enclosure, or find an NSEC3 record that + * matches the wildcard domain. + * + * Based on this we can prove either the existence of the record in @key, or NXDOMAIN or NODATA, or + * that there is no proof either way. The latter is the case if a the proof of non-existence of a given + * name uses an NSEC3 record with the opt-out bit set. Lastly, if we are given insufficient NSEC3 records + * to conclude anything we indicate this by returning NO_RR. */ +static int dnssec_test_nsec3(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { + _cleanup_free_ char *next_closer_domain = NULL, *wildcard_domain = NULL; + const char *zone, *p, *pp = NULL, *wildcard; + DnsResourceRecord *rr, *enclosure_rr, *zone_rr, *wildcard_rr = NULL; + DnsAnswerFlags flags; + int hashed_size, r; + bool a, no_closer = false, no_wildcard = false, optout = false; + + assert(key); + assert(result); + + /* First step, find the zone name and the NSEC3 parameters of the zone. + * it is sufficient to look for the longest common suffix we find with + * any NSEC3 RR in the response. Any NSEC3 record will do as all NSEC3 + * records from a given zone in a response must use the same + * parameters. */ + zone = dns_resource_key_name(key); + for (;;) { + DNS_ANSWER_FOREACH_FLAGS(zone_rr, flags, answer) { + r = nsec3_is_good(zone_rr, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_name_equal_skip(dns_resource_key_name(zone_rr->key), 1, zone); + if (r < 0) + return r; + if (r > 0) + goto found_zone; + } + + /* Strip one label from the front */ + r = dns_name_parent(&zone); + if (r < 0) + return r; + if (r == 0) + break; + } + + *result = DNSSEC_NSEC_NO_RR; + return 0; + +found_zone: + /* Second step, find the closest encloser NSEC3 RR in 'answer' that matches 'key' */ + p = dns_resource_key_name(key); + for (;;) { + _cleanup_free_ char *hashed_domain = NULL; + + hashed_size = nsec3_hashed_domain_make(zone_rr, p, zone, &hashed_domain); + if (hashed_size == -EOPNOTSUPP) { + *result = DNSSEC_NSEC_UNSUPPORTED_ALGORITHM; + return 0; + } + if (hashed_size < 0) + return hashed_size; + + DNS_ANSWER_FOREACH_FLAGS(enclosure_rr, flags, answer) { + + r = nsec3_is_good(enclosure_rr, zone_rr); + if (r < 0) + return r; + if (r == 0) + continue; + + if (enclosure_rr->nsec3.next_hashed_name_size != (size_t) hashed_size) + continue; + + r = dns_name_equal(dns_resource_key_name(enclosure_rr->key), hashed_domain); + if (r < 0) + return r; + if (r > 0) { + a = flags & DNS_ANSWER_AUTHENTICATED; + goto found_closest_encloser; + } + } + + /* We didn't find the closest encloser with this name, + * but let's remember this domain name, it might be + * the next closer name */ + + pp = p; + + /* Strip one label from the front */ + r = dns_name_parent(&p); + if (r < 0) + return r; + if (r == 0) + break; + } + + *result = DNSSEC_NSEC_NO_RR; + return 0; + +found_closest_encloser: + /* We found a closest encloser in 'p'; next closer is 'pp' */ + + if (!pp) { + /* We have an exact match! If we area looking for a DS RR, then we must insist that we got the NSEC3 RR + * from the parent. Otherwise the one from the child. Do so, by checking whether SOA and NS are + * appropriately set. */ + + if (key->type == DNS_TYPE_DS) { + if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) + return -EBADMSG; + } else { + if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_NS) && + !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) + return -EBADMSG; + } + + /* No next closer NSEC3 RR. That means there's a direct NSEC3 RR for our key. */ + if (bitmap_isset(enclosure_rr->nsec3.types, key->type)) + *result = DNSSEC_NSEC_FOUND; + else if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_CNAME)) + *result = DNSSEC_NSEC_CNAME; + else + *result = DNSSEC_NSEC_NODATA; + + if (authenticated) + *authenticated = a; + if (ttl) + *ttl = enclosure_rr->ttl; + + return 0; + } + + /* Ensure this is not a DNAME domain, see RFC5155, section 8.3. */ + if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_DNAME)) + return -EBADMSG; + + /* Ensure that this data is from the delegated domain + * (i.e. originates from the "lower" DNS server), and isn't + * just glue records (i.e. doesn't originate from the "upper" + * DNS server). */ + if (bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_NS) && + !bitmap_isset(enclosure_rr->nsec3.types, DNS_TYPE_SOA)) + return -EBADMSG; + + /* Prove that there is no next closer and whether or not there is a wildcard domain. */ + + wildcard = strjoina("*.", p); + r = nsec3_hashed_domain_make(enclosure_rr, wildcard, zone, &wildcard_domain); + if (r < 0) + return r; + if (r != hashed_size) + return -EBADMSG; + + r = nsec3_hashed_domain_make(enclosure_rr, pp, zone, &next_closer_domain); + if (r < 0) + return r; + if (r != hashed_size) + return -EBADMSG; + + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + _cleanup_free_ char *next_hashed_domain = NULL; + + r = nsec3_is_good(rr, zone_rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = nsec3_hashed_domain_format(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, zone, &next_hashed_domain); + if (r < 0) + return r; + + r = dns_name_between(dns_resource_key_name(rr->key), next_closer_domain, next_hashed_domain); + if (r < 0) + return r; + if (r > 0) { + if (rr->nsec3.flags & 1) + optout = true; + + a = a && (flags & DNS_ANSWER_AUTHENTICATED); + + no_closer = true; + } + + r = dns_name_equal(dns_resource_key_name(rr->key), wildcard_domain); + if (r < 0) + return r; + if (r > 0) { + a = a && (flags & DNS_ANSWER_AUTHENTICATED); + + wildcard_rr = rr; + } + + r = dns_name_between(dns_resource_key_name(rr->key), wildcard_domain, next_hashed_domain); + if (r < 0) + return r; + if (r > 0) { + if (rr->nsec3.flags & 1) + /* This only makes sense if we have a wildcard delegation, which is + * very unlikely, see RFC 4592, Section 4.2, but we cannot rely on + * this not happening, so hence cannot simply conclude NXDOMAIN as + * we would wish */ + optout = true; + + a = a && (flags & DNS_ANSWER_AUTHENTICATED); + + no_wildcard = true; + } + } + + if (wildcard_rr && no_wildcard) + return -EBADMSG; + + if (!no_closer) { + *result = DNSSEC_NSEC_NO_RR; + return 0; + } + + if (wildcard_rr) { + /* A wildcard exists that matches our query. */ + if (optout) + /* This is not specified in any RFC to the best of my knowledge, but + * if the next closer enclosure is covered by an opt-out NSEC3 RR + * it means that we cannot prove that the source of synthesis is + * correct, as there may be a closer match. */ + *result = DNSSEC_NSEC_OPTOUT; + else if (bitmap_isset(wildcard_rr->nsec3.types, key->type)) + *result = DNSSEC_NSEC_FOUND; + else if (bitmap_isset(wildcard_rr->nsec3.types, DNS_TYPE_CNAME)) + *result = DNSSEC_NSEC_CNAME; + else + *result = DNSSEC_NSEC_NODATA; + } else { + if (optout) + /* The RFC only specifies that we have to care for optout for NODATA for + * DS records. However, children of an insecure opt-out delegation should + * also be considered opt-out, rather than verified NXDOMAIN. + * Note that we do not require a proof of wildcard non-existence if the + * next closer domain is covered by an opt-out, as that would not provide + * any additional information. */ + *result = DNSSEC_NSEC_OPTOUT; + else if (no_wildcard) + *result = DNSSEC_NSEC_NXDOMAIN; + else { + *result = DNSSEC_NSEC_NO_RR; + + return 0; + } + } + + if (authenticated) + *authenticated = a; + + if (ttl) + *ttl = enclosure_rr->ttl; + + return 0; +} + +static int dnssec_nsec_wildcard_equal(DnsResourceRecord *rr, const char *name) { + char label[DNS_LABEL_MAX]; + const char *n; + int r; + + assert(rr); + assert(rr->key->type == DNS_TYPE_NSEC); + + /* Checks whether the specified RR has a name beginning in "*.", and if the rest is a suffix of our name */ + + if (rr->n_skip_labels_source != 1) + return 0; + + n = dns_resource_key_name(rr->key); + r = dns_label_unescape(&n, label, sizeof(label)); + if (r <= 0) + return r; + if (r != 1 || label[0] != '*') + return 0; + + return dns_name_endswith(name, n); +} + +static int dnssec_nsec_in_path(DnsResourceRecord *rr, const char *name) { + const char *nn, *common_suffix; + int r; + + assert(rr); + assert(rr->key->type == DNS_TYPE_NSEC); + + /* Checks whether the specified nsec RR indicates that name is an empty non-terminal (ENT) + * + * A couple of examples: + * + * NSEC bar → waldo.foo.bar: indicates that foo.bar exists and is an ENT + * NSEC waldo.foo.bar → yyy.zzz.xoo.bar: indicates that xoo.bar and zzz.xoo.bar exist and are ENTs + * NSEC yyy.zzz.xoo.bar → bar: indicates pretty much nothing about ENTs + */ + + /* First, determine parent of next domain. */ + nn = rr->nsec.next_domain_name; + r = dns_name_parent(&nn); + if (r <= 0) + return r; + + /* If the name we just determined is not equal or child of the name we are interested in, then we can't say + * anything at all. */ + r = dns_name_endswith(nn, name); + if (r <= 0) + return r; + + /* If the name we are interested in is not a prefix of the common suffix of the NSEC RR's owner and next domain names, then we can't say anything either. */ + r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix); + if (r < 0) + return r; + + return dns_name_endswith(name, common_suffix); +} + +static int dnssec_nsec_from_parent_zone(DnsResourceRecord *rr, const char *name) { + int r; + + assert(rr); + assert(rr->key->type == DNS_TYPE_NSEC); + + /* Checks whether this NSEC originates to the parent zone or the child zone. */ + + r = dns_name_parent(&name); + if (r <= 0) + return r; + + r = dns_name_equal(name, dns_resource_key_name(rr->key)); + if (r <= 0) + return r; + + /* DNAME, and NS without SOA is an indication for a delegation. */ + if (bitmap_isset(rr->nsec.types, DNS_TYPE_DNAME)) + return 1; + + if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) && !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) + return 1; + + return 0; +} + +static int dnssec_nsec_covers(DnsResourceRecord *rr, const char *name) { + const char *common_suffix, *p; + int r; + + assert(rr); + assert(rr->key->type == DNS_TYPE_NSEC); + + /* Checks whether the "Next Closer" is witin the space covered by the specified RR. */ + + r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix); + if (r < 0) + return r; + + for (;;) { + p = name; + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + return 0; + + r = dns_name_equal(name, common_suffix); + if (r < 0) + return r; + if (r > 0) + break; + } + + /* p is now the "Next Closer". */ + + return dns_name_between(dns_resource_key_name(rr->key), p, rr->nsec.next_domain_name); +} + +static int dnssec_nsec_covers_wildcard(DnsResourceRecord *rr, const char *name) { + const char *common_suffix, *wc; + int r; + + assert(rr); + assert(rr->key->type == DNS_TYPE_NSEC); + + /* Checks whether the "Wildcard at the Closest Encloser" is within the space covered by the specified + * RR. Specifically, checks whether 'name' has the common suffix of the NSEC RR's owner and next names as + * suffix, and whether the NSEC covers the name generated by that suffix prepended with an asterisk label. + * + * NSEC bar → waldo.foo.bar: indicates that *.bar and *.foo.bar do not exist + * NSEC waldo.foo.bar → yyy.zzz.xoo.bar: indicates that *.xoo.bar and *.zzz.xoo.bar do not exist (and more ...) + * NSEC yyy.zzz.xoo.bar → bar: indicates that a number of wildcards don#t exist either... + */ + + r = dns_name_common_suffix(dns_resource_key_name(rr->key), rr->nsec.next_domain_name, &common_suffix); + if (r < 0) + return r; + + /* If the common suffix is not shared by the name we are interested in, it has nothing to say for us. */ + r = dns_name_endswith(name, common_suffix); + if (r <= 0) + return r; + + wc = strjoina("*.", common_suffix); + return dns_name_between(dns_resource_key_name(rr->key), wc, rr->nsec.next_domain_name); +} + +int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { + bool have_nsec3 = false, covering_rr_authenticated = false, wildcard_rr_authenticated = false; + DnsResourceRecord *rr, *covering_rr = NULL, *wildcard_rr = NULL; + DnsAnswerFlags flags; + const char *name; + int r; + + assert(key); + assert(result); + + /* Look for any NSEC/NSEC3 RRs that say something about the specified key. */ + + name = dns_resource_key_name(key); + + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + + if (rr->key->class != key->class) + continue; + + have_nsec3 = have_nsec3 || (rr->key->type == DNS_TYPE_NSEC3); + + if (rr->key->type != DNS_TYPE_NSEC) + continue; + + /* The following checks only make sense for NSEC RRs that are not expanded from a wildcard */ + r = dns_resource_record_is_synthetic(rr); + if (r < 0) + return r; + if (r > 0) + continue; + + /* Check if this is a direct match. If so, we have encountered a NODATA case */ + r = dns_name_equal(dns_resource_key_name(rr->key), name); + if (r < 0) + return r; + if (r == 0) { + /* If it's not a direct match, maybe it's a wild card match? */ + r = dnssec_nsec_wildcard_equal(rr, name); + if (r < 0) + return r; + } + if (r > 0) { + if (key->type == DNS_TYPE_DS) { + /* If we look for a DS RR and the server sent us the NSEC RR of the child zone + * we have a problem. For DS RRs we want the NSEC RR from the parent */ + if (bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) + continue; + } else { + /* For all RR types, ensure that if NS is set SOA is set too, so that we know + * we got the child's NSEC. */ + if (bitmap_isset(rr->nsec.types, DNS_TYPE_NS) && + !bitmap_isset(rr->nsec.types, DNS_TYPE_SOA)) + continue; + } + + if (bitmap_isset(rr->nsec.types, key->type)) + *result = DNSSEC_NSEC_FOUND; + else if (bitmap_isset(rr->nsec.types, DNS_TYPE_CNAME)) + *result = DNSSEC_NSEC_CNAME; + else + *result = DNSSEC_NSEC_NODATA; + + if (authenticated) + *authenticated = flags & DNS_ANSWER_AUTHENTICATED; + if (ttl) + *ttl = rr->ttl; + + return 0; + } + + /* Check if the name we are looking for is an empty non-terminal within the owner or next name + * of the NSEC RR. */ + r = dnssec_nsec_in_path(rr, name); + if (r < 0) + return r; + if (r > 0) { + *result = DNSSEC_NSEC_NODATA; + + if (authenticated) + *authenticated = flags & DNS_ANSWER_AUTHENTICATED; + if (ttl) + *ttl = rr->ttl; + + return 0; + } + + /* The following two "covering" checks, are not useful if the NSEC is from the parent */ + r = dnssec_nsec_from_parent_zone(rr, name); + if (r < 0) + return r; + if (r > 0) + continue; + + /* Check if this NSEC RR proves the absence of an explicit RR under this name */ + r = dnssec_nsec_covers(rr, name); + if (r < 0) + return r; + if (r > 0 && (!covering_rr || !covering_rr_authenticated)) { + covering_rr = rr; + covering_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED; + } + + /* Check if this NSEC RR proves the absence of a wildcard RR under this name */ + r = dnssec_nsec_covers_wildcard(rr, name); + if (r < 0) + return r; + if (r > 0 && (!wildcard_rr || !wildcard_rr_authenticated)) { + wildcard_rr = rr; + wildcard_rr_authenticated = flags & DNS_ANSWER_AUTHENTICATED; + } + } + + if (covering_rr && wildcard_rr) { + /* If we could prove that neither the name itself, nor the wildcard at the closest encloser exists, we + * proved the NXDOMAIN case. */ + *result = DNSSEC_NSEC_NXDOMAIN; + + if (authenticated) + *authenticated = covering_rr_authenticated && wildcard_rr_authenticated; + if (ttl) + *ttl = MIN(covering_rr->ttl, wildcard_rr->ttl); + + return 0; + } + + /* OK, this was not sufficient. Let's see if NSEC3 can help. */ + if (have_nsec3) + return dnssec_test_nsec3(answer, key, result, authenticated, ttl); + + /* No approproate NSEC RR found, report this. */ + *result = DNSSEC_NSEC_NO_RR; + return 0; +} + +static int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, const char *name, const char *zone, bool *authenticated) { + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int r; + + assert(name); + assert(zone); + + /* Checks whether there's an NSEC/NSEC3 that proves that the specified 'name' is non-existing in the specified + * 'zone'. The 'zone' must be a suffix of the 'name'. */ + + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + bool found = false; + + if (rr->key->type != type && type != DNS_TYPE_ANY) + continue; + + switch (rr->key->type) { + + case DNS_TYPE_NSEC: + + /* We only care for NSEC RRs from the indicated zone */ + r = dns_resource_record_is_signer(rr, zone); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_name_between(dns_resource_key_name(rr->key), name, rr->nsec.next_domain_name); + if (r < 0) + return r; + + found = r > 0; + break; + + case DNS_TYPE_NSEC3: { + _cleanup_free_ char *hashed_domain = NULL, *next_hashed_domain = NULL; + + /* We only care for NSEC3 RRs from the indicated zone */ + r = dns_resource_record_is_signer(rr, zone); + if (r < 0) + return r; + if (r == 0) + continue; + + r = nsec3_is_good(rr, NULL); + if (r < 0) + return r; + if (r == 0) + break; + + /* Format the domain we are testing with the NSEC3 RR's hash function */ + r = nsec3_hashed_domain_make( + rr, + name, + zone, + &hashed_domain); + if (r < 0) + return r; + if ((size_t) r != rr->nsec3.next_hashed_name_size) + break; + + /* Format the NSEC3's next hashed name as proper domain name */ + r = nsec3_hashed_domain_format( + rr->nsec3.next_hashed_name, + rr->nsec3.next_hashed_name_size, + zone, + &next_hashed_domain); + if (r < 0) + return r; + + r = dns_name_between(dns_resource_key_name(rr->key), hashed_domain, next_hashed_domain); + if (r < 0) + return r; + + found = r > 0; + break; + } + + default: + continue; + } + + if (found) { + if (authenticated) + *authenticated = flags & DNS_ANSWER_AUTHENTICATED; + return 1; + } + } + + return 0; +} + +static int dnssec_test_positive_wildcard_nsec3( + DnsAnswer *answer, + const char *name, + const char *source, + const char *zone, + bool *authenticated) { + + const char *next_closer = NULL; + int r; + + /* Run a positive NSEC3 wildcard proof. Specifically: + * + * A proof that the "next closer" of the generating wildcard does not exist. + * + * Note a key difference between the NSEC3 and NSEC versions of the proof. NSEC RRs don't have to exist for + * empty non-transients. NSEC3 RRs however have to. This means it's sufficient to check if the next closer name + * exists for the NSEC3 RR and we are done. + * + * To prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f all we have to check is that + * c.d.e.f does not exist. */ + + for (;;) { + next_closer = name; + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + return 0; + + r = dns_name_equal(name, source); + if (r < 0) + return r; + if (r > 0) + break; + } + + return dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC3, next_closer, zone, authenticated); +} + +static int dnssec_test_positive_wildcard_nsec( + DnsAnswer *answer, + const char *name, + const char *source, + const char *zone, + bool *_authenticated) { + + bool authenticated = true; + int r; + + /* Run a positive NSEC wildcard proof. Specifically: + * + * A proof that there's neither a wildcard name nor a non-wildcard name that is a suffix of the name "name" and + * a prefix of the synthesizing source "source" in the zone "zone". + * + * See RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4 + * + * Note that if we want to prove that a.b.c.d.e.f is rightfully synthesized from a wildcard *.d.e.f, then we + * have to prove that none of the following exist: + * + * 1) a.b.c.d.e.f + * 2) *.b.c.d.e.f + * 3) b.c.d.e.f + * 4) *.c.d.e.f + * 5) c.d.e.f + * + */ + + for (;;) { + _cleanup_free_ char *wc = NULL; + bool a = false; + + /* Check if there's an NSEC or NSEC3 RR that proves that the mame we determined is really non-existing, + * i.e between the owner name and the next name of an NSEC RR. */ + r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, name, zone, &a); + if (r <= 0) + return r; + + authenticated = authenticated && a; + + /* Strip one label off */ + r = dns_name_parent(&name); + if (r <= 0) + return r; + + /* Did we reach the source of synthesis? */ + r = dns_name_equal(name, source); + if (r < 0) + return r; + if (r > 0) { + /* Successful exit */ + *_authenticated = authenticated; + return 1; + } + + /* Safety check, that the source of synthesis is still our suffix */ + r = dns_name_endswith(name, source); + if (r < 0) + return r; + if (r == 0) + return -EBADMSG; + + /* Replace the label we stripped off with an asterisk */ + wc = strappend("*.", name); + if (!wc) + return -ENOMEM; + + /* And check if the proof holds for the asterisk name, too */ + r = dnssec_nsec_test_enclosed(answer, DNS_TYPE_NSEC, wc, zone, &a); + if (r <= 0) + return r; + + authenticated = authenticated && a; + /* In the next iteration we'll check the non-asterisk-prefixed version */ + } +} + +int dnssec_test_positive_wildcard( + DnsAnswer *answer, + const char *name, + const char *source, + const char *zone, + bool *authenticated) { + + int r; + + assert(name); + assert(source); + assert(zone); + assert(authenticated); + + r = dns_answer_contains_zone_nsec3(answer, zone); + if (r < 0) + return r; + if (r > 0) + return dnssec_test_positive_wildcard_nsec3(answer, name, source, zone, authenticated); + else + return dnssec_test_positive_wildcard_nsec(answer, name, source, zone, authenticated); +} + +#else + +int dnssec_verify_rrset( + DnsAnswer *a, + const DnsResourceKey *key, + DnsResourceRecord *rrsig, + DnsResourceRecord *dnskey, + usec_t realtime, + DnssecResult *result) { + + return -EOPNOTSUPP; +} + +int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok) { + + return -EOPNOTSUPP; +} + +int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig) { + + return -EOPNOTSUPP; +} + +int dnssec_verify_rrset_search( + DnsAnswer *a, + const DnsResourceKey *key, + DnsAnswer *validated_dnskeys, + usec_t realtime, + DnssecResult *result, + DnsResourceRecord **ret_rrsig) { + + return -EOPNOTSUPP; +} + +int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key) { + + return -EOPNOTSUPP; +} + +int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke) { + + return -EOPNOTSUPP; +} + +int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds) { + + return -EOPNOTSUPP; +} + +int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret) { + + return -EOPNOTSUPP; +} + +int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl) { + + return -EOPNOTSUPP; +} + +int dnssec_test_positive_wildcard( + DnsAnswer *answer, + const char *name, + const char *source, + const char *zone, + bool *authenticated) { + + return -EOPNOTSUPP; +} + +#endif + +static const char* const dnssec_result_table[_DNSSEC_RESULT_MAX] = { + [DNSSEC_VALIDATED] = "validated", + [DNSSEC_VALIDATED_WILDCARD] = "validated-wildcard", + [DNSSEC_INVALID] = "invalid", + [DNSSEC_SIGNATURE_EXPIRED] = "signature-expired", + [DNSSEC_UNSUPPORTED_ALGORITHM] = "unsupported-algorithm", + [DNSSEC_NO_SIGNATURE] = "no-signature", + [DNSSEC_MISSING_KEY] = "missing-key", + [DNSSEC_UNSIGNED] = "unsigned", + [DNSSEC_FAILED_AUXILIARY] = "failed-auxiliary", + [DNSSEC_NSEC_MISMATCH] = "nsec-mismatch", + [DNSSEC_INCOMPATIBLE_SERVER] = "incompatible-server", +}; +DEFINE_STRING_TABLE_LOOKUP(dnssec_result, DnssecResult); + +static const char* const dnssec_verdict_table[_DNSSEC_VERDICT_MAX] = { + [DNSSEC_SECURE] = "secure", + [DNSSEC_INSECURE] = "insecure", + [DNSSEC_BOGUS] = "bogus", + [DNSSEC_INDETERMINATE] = "indeterminate", +}; +DEFINE_STRING_TABLE_LOOKUP(dnssec_verdict, DnssecVerdict); diff --git a/src/grp-resolve/libbasic-dns/src/resolved-dns-packet.c b/src/grp-resolve/libbasic-dns/src/resolved-dns-packet.c new file mode 100644 index 0000000000..6f356cba7d --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-packet.c @@ -0,0 +1,2301 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/unaligned.h" +#include "systemd-basic/utf8.h" +#include "systemd-basic/util.h" +#include "systemd-shared/dns-domain.h" + +#define EDNS0_OPT_DO (1<<15) + +typedef struct DnsPacketRewinder { + DnsPacket *packet; + size_t saved_rindex; +} DnsPacketRewinder; + +static void rewind_dns_packet(DnsPacketRewinder *rewinder) { + if (rewinder->packet) + dns_packet_rewind(rewinder->packet, rewinder->saved_rindex); +} + +#define INIT_REWINDER(rewinder, p) do { rewinder.packet = p; rewinder.saved_rindex = p->rindex; } while (0) +#define CANCEL_REWINDER(rewinder) do { rewinder.packet = NULL; } while (0) + +int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { + DnsPacket *p; + size_t a; + + assert(ret); + + if (mtu <= UDP_PACKET_HEADER_SIZE) + a = DNS_PACKET_SIZE_START; + else + a = mtu - UDP_PACKET_HEADER_SIZE; + + if (a < DNS_PACKET_HEADER_SIZE) + a = DNS_PACKET_HEADER_SIZE; + + /* round up to next page size */ + a = PAGE_ALIGN(ALIGN(sizeof(DnsPacket)) + a) - ALIGN(sizeof(DnsPacket)); + + /* make sure we never allocate more than useful */ + if (a > DNS_PACKET_SIZE_MAX) + a = DNS_PACKET_SIZE_MAX; + + p = malloc0(ALIGN(sizeof(DnsPacket)) + a); + if (!p) + return -ENOMEM; + + p->size = p->rindex = DNS_PACKET_HEADER_SIZE; + p->allocated = a; + p->protocol = protocol; + p->opt_start = p->opt_size = (size_t) -1; + p->n_ref = 1; + + *ret = p; + + return 0; +} + +void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated) { + + DnsPacketHeader *h; + + assert(p); + + h = DNS_PACKET_HEADER(p); + + switch(p->protocol) { + case DNS_PROTOCOL_LLMNR: + assert(!truncated); + + h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, + 0 /* opcode */, + 0 /* c */, + 0 /* tc */, + 0 /* t */, + 0 /* ra */, + 0 /* ad */, + 0 /* cd */, + 0 /* rcode */)); + break; + + case DNS_PROTOCOL_MDNS: + h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, + 0 /* opcode */, + 0 /* aa */, + truncated /* tc */, + 0 /* rd (ask for recursion) */, + 0 /* ra */, + 0 /* ad */, + 0 /* cd */, + 0 /* rcode */)); + break; + + default: + assert(!truncated); + + h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, + 0 /* opcode */, + 0 /* aa */, + 0 /* tc */, + 1 /* rd (ask for recursion) */, + 0 /* ra */, + 0 /* ad */, + dnssec_checking_disabled /* cd */, + 0 /* rcode */)); + } +} + +int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled) { + DnsPacket *p; + int r; + + assert(ret); + + r = dns_packet_new(&p, protocol, mtu); + if (r < 0) + return r; + + /* Always set the TC bit to 0 initially. + * If there are multiple packets later, we'll update the bit shortly before sending. + */ + dns_packet_set_flags(p, dnssec_checking_disabled, false); + + *ret = p; + return 0; +} + +DnsPacket *dns_packet_ref(DnsPacket *p) { + + if (!p) + return NULL; + + assert(!p->on_stack); + + assert(p->n_ref > 0); + p->n_ref++; + return p; +} + +static void dns_packet_free(DnsPacket *p) { + char *s; + + assert(p); + + dns_question_unref(p->question); + dns_answer_unref(p->answer); + dns_resource_record_unref(p->opt); + + while ((s = hashmap_steal_first_key(p->names))) + free(s); + hashmap_free(p->names); + + free(p->_data); + + if (!p->on_stack) + free(p); +} + +DnsPacket *dns_packet_unref(DnsPacket *p) { + if (!p) + return NULL; + + assert(p->n_ref > 0); + + dns_packet_unref(p->more); + + if (p->n_ref == 1) + dns_packet_free(p); + else + p->n_ref--; + + return NULL; +} + +int dns_packet_validate(DnsPacket *p) { + assert(p); + + if (p->size < DNS_PACKET_HEADER_SIZE) + return -EBADMSG; + + if (p->size > DNS_PACKET_SIZE_MAX) + return -EBADMSG; + + return 1; +} + +int dns_packet_validate_reply(DnsPacket *p) { + int r; + + assert(p); + + r = dns_packet_validate(p); + if (r < 0) + return r; + + if (DNS_PACKET_QR(p) != 1) + return 0; + + if (DNS_PACKET_OPCODE(p) != 0) + return -EBADMSG; + + switch (p->protocol) { + + case DNS_PROTOCOL_LLMNR: + /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; + + break; + + case DNS_PROTOCOL_MDNS: + /* RFC 6762, Section 18 */ + if (DNS_PACKET_RCODE(p) != 0) + return -EBADMSG; + + break; + + default: + break; + } + + return 1; +} + +int dns_packet_validate_query(DnsPacket *p) { + int r; + + assert(p); + + r = dns_packet_validate(p); + if (r < 0) + return r; + + if (DNS_PACKET_QR(p) != 0) + return 0; + + if (DNS_PACKET_OPCODE(p) != 0) + return -EBADMSG; + + if (DNS_PACKET_TC(p)) + return -EBADMSG; + + switch (p->protocol) { + + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_DNS: + /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; + + /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ + if (DNS_PACKET_ANCOUNT(p) > 0) + return -EBADMSG; + + /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ + if (DNS_PACKET_NSCOUNT(p) > 0) + return -EBADMSG; + + break; + + case DNS_PROTOCOL_MDNS: + /* RFC 6762, Section 18 */ + if (DNS_PACKET_AA(p) != 0 || + DNS_PACKET_RD(p) != 0 || + DNS_PACKET_RA(p) != 0 || + DNS_PACKET_AD(p) != 0 || + DNS_PACKET_CD(p) != 0 || + DNS_PACKET_RCODE(p) != 0) + return -EBADMSG; + + break; + + default: + break; + } + + return 1; +} + +static int dns_packet_extend(DnsPacket *p, size_t add, void **ret, size_t *start) { + assert(p); + + if (p->size + add > p->allocated) { + size_t a; + + a = PAGE_ALIGN((p->size + add) * 2); + if (a > DNS_PACKET_SIZE_MAX) + a = DNS_PACKET_SIZE_MAX; + + if (p->size + add > a) + return -EMSGSIZE; + + if (p->_data) { + void *d; + + d = realloc(p->_data, a); + if (!d) + return -ENOMEM; + + p->_data = d; + } else { + p->_data = malloc(a); + if (!p->_data) + return -ENOMEM; + + memcpy(p->_data, (uint8_t*) p + ALIGN(sizeof(DnsPacket)), p->size); + memzero((uint8_t*) p->_data + p->size, a - p->size); + } + + p->allocated = a; + } + + if (start) + *start = p->size; + + if (ret) + *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->size; + + p->size += add; + return 0; +} + +void dns_packet_truncate(DnsPacket *p, size_t sz) { + Iterator i; + char *s; + void *n; + + assert(p); + + if (p->size <= sz) + return; + + HASHMAP_FOREACH_KEY(n, s, p->names, i) { + + if (PTR_TO_SIZE(n) < sz) + continue; + + hashmap_remove(p->names, s); + free(s); + } + + p->size = sz; +} + +int dns_packet_append_blob(DnsPacket *p, const void *d, size_t l, size_t *start) { + void *q; + int r; + + assert(p); + + r = dns_packet_extend(p, l, &q, start); + if (r < 0) + return r; + + memcpy(q, d, l); + return 0; +} + +int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start) { + void *d; + int r; + + assert(p); + + r = dns_packet_extend(p, sizeof(uint8_t), &d, start); + if (r < 0) + return r; + + ((uint8_t*) d)[0] = v; + + return 0; +} + +int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start) { + void *d; + int r; + + assert(p); + + r = dns_packet_extend(p, sizeof(uint16_t), &d, start); + if (r < 0) + return r; + + unaligned_write_be16(d, v); + + return 0; +} + +int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start) { + void *d; + int r; + + assert(p); + + r = dns_packet_extend(p, sizeof(uint32_t), &d, start); + if (r < 0) + return r; + + unaligned_write_be32(d, v); + + return 0; +} + +int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start) { + assert(p); + assert(s); + + return dns_packet_append_raw_string(p, s, strlen(s), start); +} + +int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_t *start) { + void *d; + int r; + + assert(p); + assert(s || size == 0); + + if (size > 255) + return -E2BIG; + + r = dns_packet_extend(p, 1 + size, &d, start); + if (r < 0) + return r; + + ((uint8_t*) d)[0] = (uint8_t) size; + + memcpy_safe(((uint8_t*) d) + 1, s, size); + + return 0; +} + +int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, bool canonical_candidate, size_t *start) { + uint8_t *w; + int r; + + /* Append a label to a packet. Optionally, does this in DNSSEC + * canonical form, if this label is marked as a candidate for + * it, and the canonical form logic is enabled for the + * packet */ + + assert(p); + assert(d); + + if (l > DNS_LABEL_MAX) + return -E2BIG; + + r = dns_packet_extend(p, 1 + l, (void**) &w, start); + if (r < 0) + return r; + + *(w++) = (uint8_t) l; + + if (p->canonical_form && canonical_candidate) { + size_t i; + + /* Generate in canonical form, as defined by DNSSEC + * RFC 4034, Section 6.2, i.e. all lower-case. */ + + for (i = 0; i < l; i++) + w[i] = (uint8_t) ascii_tolower(d[i]); + } else + /* Otherwise, just copy the string unaltered. This is + * essential for DNS-SD, where the casing of labels + * matters and needs to be retained. */ + memcpy(w, d, l); + + return 0; +} + +int dns_packet_append_name( + DnsPacket *p, + const char *name, + bool allow_compression, + bool canonical_candidate, + size_t *start) { + + size_t saved_size; + int r; + + assert(p); + assert(name); + + if (p->refuse_compression) + allow_compression = false; + + saved_size = p->size; + + while (!dns_name_is_root(name)) { + const char *z = name; + char label[DNS_LABEL_MAX]; + size_t n = 0; + + if (allow_compression) + n = PTR_TO_SIZE(hashmap_get(p->names, name)); + if (n > 0) { + assert(n < p->size); + + if (n < 0x4000) { + r = dns_packet_append_uint16(p, 0xC000 | n, NULL); + if (r < 0) + goto fail; + + goto done; + } + } + + r = dns_label_unescape(&name, label, sizeof(label)); + if (r < 0) + goto fail; + + r = dns_packet_append_label(p, label, r, canonical_candidate, &n); + if (r < 0) + goto fail; + + if (allow_compression) { + _cleanup_free_ char *s = NULL; + + s = strdup(z); + if (!s) { + r = -ENOMEM; + goto fail; + } + + r = hashmap_ensure_allocated(&p->names, &dns_name_hash_ops); + if (r < 0) + goto fail; + + r = hashmap_put(p->names, s, SIZE_TO_PTR(n)); + if (r < 0) + goto fail; + + s = NULL; + } + } + + r = dns_packet_append_uint8(p, 0, NULL); + if (r < 0) + return r; + +done: + if (start) + *start = saved_size; + + return 0; + +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start) { + size_t saved_size; + int r; + + assert(p); + assert(k); + + saved_size = p->size; + + r = dns_packet_append_name(p, dns_resource_key_name(k), true, true, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, k->type, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, k->class, NULL); + if (r < 0) + goto fail; + + if (start) + *start = saved_size; + + return 0; + +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +static int dns_packet_append_type_window(DnsPacket *p, uint8_t window, uint8_t length, const uint8_t *types, size_t *start) { + size_t saved_size; + int r; + + assert(p); + assert(types); + assert(length > 0); + + saved_size = p->size; + + r = dns_packet_append_uint8(p, window, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, length, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, types, length, NULL); + if (r < 0) + goto fail; + + if (start) + *start = saved_size; + + return 0; +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +static int dns_packet_append_types(DnsPacket *p, Bitmap *types, size_t *start) { + Iterator i; + uint8_t window = 0; + uint8_t entry = 0; + uint8_t bitmaps[32] = {}; + unsigned n; + size_t saved_size; + int r; + + assert(p); + + saved_size = p->size; + + BITMAP_FOREACH(n, types, i) { + assert(n <= 0xffff); + + if ((n >> 8) != window && bitmaps[entry / 8] != 0) { + r = dns_packet_append_type_window(p, window, entry / 8 + 1, bitmaps, NULL); + if (r < 0) + goto fail; + + zero(bitmaps); + } + + window = n >> 8; + entry = n & 255; + + bitmaps[entry / 8] |= 1 << (7 - (entry % 8)); + } + + if (bitmaps[entry / 8] != 0) { + r = dns_packet_append_type_window(p, window, entry / 8 + 1, bitmaps, NULL); + if (r < 0) + goto fail; + } + + if (start) + *start = saved_size; + + return 0; +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +/* Append the OPT pseudo-RR described in RFC6891 */ +int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, int rcode, size_t *start) { + size_t saved_size; + int r; + + assert(p); + /* we must never advertise supported packet size smaller than the legacy max */ + assert(max_udp_size >= DNS_PACKET_UNICAST_SIZE_MAX); + assert(rcode >= 0); + assert(rcode <= _DNS_RCODE_MAX); + + if (p->opt_start != (size_t) -1) + return -EBUSY; + + assert(p->opt_size == (size_t) -1); + + saved_size = p->size; + + /* empty name */ + r = dns_packet_append_uint8(p, 0, NULL); + if (r < 0) + return r; + + /* type */ + r = dns_packet_append_uint16(p, DNS_TYPE_OPT, NULL); + if (r < 0) + goto fail; + + /* class: maximum udp packet that can be received */ + r = dns_packet_append_uint16(p, max_udp_size, NULL); + if (r < 0) + goto fail; + + /* extended RCODE and VERSION */ + r = dns_packet_append_uint16(p, ((uint16_t) rcode & 0x0FF0) << 4, NULL); + if (r < 0) + goto fail; + + /* flags: DNSSEC OK (DO), see RFC3225 */ + r = dns_packet_append_uint16(p, edns0_do ? EDNS0_OPT_DO : 0, NULL); + if (r < 0) + goto fail; + + /* RDLENGTH */ + if (edns0_do && !DNS_PACKET_QR(p)) { + /* If DO is on and this is not a reply, also append RFC6975 Algorithm data */ + + static const uint8_t rfc6975[] = { + + 0, 5, /* OPTION_CODE: DAU */ + 0, 6, /* LIST_LENGTH */ + DNSSEC_ALGORITHM_RSASHA1, + DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1, + DNSSEC_ALGORITHM_RSASHA256, + DNSSEC_ALGORITHM_RSASHA512, + DNSSEC_ALGORITHM_ECDSAP256SHA256, + DNSSEC_ALGORITHM_ECDSAP384SHA384, + + 0, 6, /* OPTION_CODE: DHU */ + 0, 3, /* LIST_LENGTH */ + DNSSEC_DIGEST_SHA1, + DNSSEC_DIGEST_SHA256, + DNSSEC_DIGEST_SHA384, + + 0, 7, /* OPTION_CODE: N3U */ + 0, 1, /* LIST_LENGTH */ + NSEC3_ALGORITHM_SHA1, + }; + + r = dns_packet_append_uint16(p, sizeof(rfc6975), NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rfc6975, sizeof(rfc6975), NULL); + } else + r = dns_packet_append_uint16(p, 0, NULL); + if (r < 0) + goto fail; + + DNS_PACKET_HEADER(p)->arcount = htobe16(DNS_PACKET_ARCOUNT(p) + 1); + + p->opt_start = saved_size; + p->opt_size = p->size - saved_size; + + if (start) + *start = saved_size; + + return 0; + +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +int dns_packet_truncate_opt(DnsPacket *p) { + assert(p); + + if (p->opt_start == (size_t) -1) { + assert(p->opt_size == (size_t) -1); + return 0; + } + + assert(p->opt_size != (size_t) -1); + assert(DNS_PACKET_ARCOUNT(p) > 0); + + if (p->opt_start + p->opt_size != p->size) + return -EBUSY; + + dns_packet_truncate(p, p->opt_start); + DNS_PACKET_HEADER(p)->arcount = htobe16(DNS_PACKET_ARCOUNT(p) - 1); + p->opt_start = p->opt_size = (size_t) -1; + + return 1; +} + +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start) { + + size_t saved_size, rdlength_offset, end, rdlength, rds; + int r; + + assert(p); + assert(rr); + + saved_size = p->size; + + r = dns_packet_append_key(p, rr->key, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->ttl, NULL); + if (r < 0) + goto fail; + + /* Initially we write 0 here */ + r = dns_packet_append_uint16(p, 0, &rdlength_offset); + if (r < 0) + goto fail; + + rds = p->size - saved_size; + + switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { + + case DNS_TYPE_SRV: + r = dns_packet_append_uint16(p, rr->srv.priority, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, rr->srv.weight, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, rr->srv.port, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_name(p, rr->srv.name, true, false, NULL); + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + r = dns_packet_append_name(p, rr->ptr.name, true, false, NULL); + break; + + case DNS_TYPE_HINFO: + r = dns_packet_append_string(p, rr->hinfo.cpu, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_string(p, rr->hinfo.os, NULL); + break; + + case DNS_TYPE_SPF: /* exactly the same as TXT */ + case DNS_TYPE_TXT: + + if (!rr->txt.items) { + /* RFC 6763, section 6.1 suggests to generate + * single empty string for an empty array. */ + + r = dns_packet_append_raw_string(p, NULL, 0, NULL); + if (r < 0) + goto fail; + } else { + DnsTxtItem *i; + + LIST_FOREACH(items, i, rr->txt.items) { + r = dns_packet_append_raw_string(p, i->data, i->length, NULL); + if (r < 0) + goto fail; + } + } + + r = 0; + break; + + case DNS_TYPE_A: + r = dns_packet_append_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); + break; + + case DNS_TYPE_AAAA: + r = dns_packet_append_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); + break; + + case DNS_TYPE_SOA: + r = dns_packet_append_name(p, rr->soa.mname, true, false, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_name(p, rr->soa.rname, true, false, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.serial, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.refresh, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.retry, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.expire, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->soa.minimum, NULL); + break; + + case DNS_TYPE_MX: + r = dns_packet_append_uint16(p, rr->mx.priority, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_name(p, rr->mx.exchange, true, false, NULL); + break; + + case DNS_TYPE_LOC: + r = dns_packet_append_uint8(p, rr->loc.version, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->loc.size, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->loc.horiz_pre, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->loc.vert_pre, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->loc.latitude, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->loc.longitude, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->loc.altitude, NULL); + break; + + case DNS_TYPE_DS: + r = dns_packet_append_uint16(p, rr->ds.key_tag, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->ds.algorithm, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->ds.digest_type, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->ds.digest, rr->ds.digest_size, NULL); + break; + + case DNS_TYPE_SSHFP: + r = dns_packet_append_uint8(p, rr->sshfp.algorithm, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->sshfp.fptype, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->sshfp.fingerprint, rr->sshfp.fingerprint_size, NULL); + break; + + case DNS_TYPE_DNSKEY: + r = dns_packet_append_uint16(p, rr->dnskey.flags, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->dnskey.protocol, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->dnskey.algorithm, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->dnskey.key, rr->dnskey.key_size, NULL); + break; + + case DNS_TYPE_RRSIG: + r = dns_packet_append_uint16(p, rr->rrsig.type_covered, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->rrsig.algorithm, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->rrsig.labels, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->rrsig.original_ttl, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->rrsig.expiration, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint32(p, rr->rrsig.inception, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, rr->rrsig.key_tag, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_name(p, rr->rrsig.signer, false, true, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->rrsig.signature, rr->rrsig.signature_size, NULL); + break; + + case DNS_TYPE_NSEC: + r = dns_packet_append_name(p, rr->nsec.next_domain_name, false, false, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_types(p, rr->nsec.types, NULL); + if (r < 0) + goto fail; + + break; + + case DNS_TYPE_NSEC3: + r = dns_packet_append_uint8(p, rr->nsec3.algorithm, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->nsec3.flags, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint16(p, rr->nsec3.iterations, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->nsec3.salt_size, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->nsec3.salt, rr->nsec3.salt_size, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->nsec3.next_hashed_name_size, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_types(p, rr->nsec3.types, NULL); + if (r < 0) + goto fail; + + break; + + case DNS_TYPE_TLSA: + r = dns_packet_append_uint8(p, rr->tlsa.cert_usage, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->tlsa.selector, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_uint8(p, rr->tlsa.matching_type, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->tlsa.data, rr->tlsa.data_size, NULL); + break; + + case DNS_TYPE_CAA: + r = dns_packet_append_uint8(p, rr->caa.flags, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_string(p, rr->caa.tag, NULL); + if (r < 0) + goto fail; + + r = dns_packet_append_blob(p, rr->caa.value, rr->caa.value_size, NULL); + break; + + case DNS_TYPE_OPT: + case DNS_TYPE_OPENPGPKEY: + case _DNS_TYPE_INVALID: /* unparseable */ + default: + + r = dns_packet_append_blob(p, rr->generic.data, rr->generic.data_size, NULL); + break; + } + if (r < 0) + goto fail; + + /* Let's calculate the actual data size and update the field */ + rdlength = p->size - rdlength_offset - sizeof(uint16_t); + if (rdlength > 0xFFFF) { + r = -ENOSPC; + goto fail; + } + + end = p->size; + p->size = rdlength_offset; + r = dns_packet_append_uint16(p, rdlength, NULL); + if (r < 0) + goto fail; + p->size = end; + + if (start) + *start = saved_size; + + if (rdata_start) + *rdata_start = rds; + + return 0; + +fail: + dns_packet_truncate(p, saved_size); + return r; +} + +int dns_packet_append_question(DnsPacket *p, DnsQuestion *q) { + DnsResourceKey *key; + int r; + + assert(p); + + DNS_QUESTION_FOREACH(key, q) { + r = dns_packet_append_key(p, key, NULL); + if (r < 0) + return r; + } + + return 0; +} + +int dns_packet_append_answer(DnsPacket *p, DnsAnswer *a) { + DnsResourceRecord *rr; + int r; + + assert(p); + + DNS_ANSWER_FOREACH(rr, a) { + r = dns_packet_append_rr(p, rr, NULL, NULL); + if (r < 0) + return r; + } + + return 0; +} + +int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) { + assert(p); + + if (p->rindex + sz > p->size) + return -EMSGSIZE; + + if (ret) + *ret = (uint8_t*) DNS_PACKET_DATA(p) + p->rindex; + + if (start) + *start = p->rindex; + + p->rindex += sz; + return 0; +} + +void dns_packet_rewind(DnsPacket *p, size_t idx) { + assert(p); + assert(idx <= p->size); + assert(idx >= DNS_PACKET_HEADER_SIZE); + + p->rindex = idx; +} + +int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start) { + const void *q; + int r; + + assert(p); + assert(d); + + r = dns_packet_read(p, sz, &q, start); + if (r < 0) + return r; + + memcpy(d, q, sz); + return 0; +} + +static int dns_packet_read_memdup( + DnsPacket *p, size_t size, + void **ret, size_t *ret_size, + size_t *ret_start) { + + const void *src; + size_t start; + int r; + + assert(p); + assert(ret); + + r = dns_packet_read(p, size, &src, &start); + if (r < 0) + return r; + + if (size <= 0) + *ret = NULL; + else { + void *copy; + + copy = memdup(src, size); + if (!copy) + return -ENOMEM; + + *ret = copy; + } + + if (ret_size) + *ret_size = size; + if (ret_start) + *ret_start = start; + + return 0; +} + +int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start) { + const void *d; + int r; + + assert(p); + + r = dns_packet_read(p, sizeof(uint8_t), &d, start); + if (r < 0) + return r; + + *ret = ((uint8_t*) d)[0]; + return 0; +} + +int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start) { + const void *d; + int r; + + assert(p); + + r = dns_packet_read(p, sizeof(uint16_t), &d, start); + if (r < 0) + return r; + + *ret = unaligned_read_be16(d); + + return 0; +} + +int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) { + const void *d; + int r; + + assert(p); + + r = dns_packet_read(p, sizeof(uint32_t), &d, start); + if (r < 0) + return r; + + *ret = unaligned_read_be32(d); + + return 0; +} + +int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) { + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + const void *d; + char *t; + uint8_t c; + int r; + + assert(p); + INIT_REWINDER(rewinder, p); + + r = dns_packet_read_uint8(p, &c, NULL); + if (r < 0) + return r; + + r = dns_packet_read(p, c, &d, NULL); + if (r < 0) + return r; + + if (memchr(d, 0, c)) + return -EBADMSG; + + t = strndup(d, c); + if (!t) + return -ENOMEM; + + if (!utf8_is_valid(t)) { + free(t); + return -EBADMSG; + } + + *ret = t; + + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start) { + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + uint8_t c; + int r; + + assert(p); + INIT_REWINDER(rewinder, p); + + r = dns_packet_read_uint8(p, &c, NULL); + if (r < 0) + return r; + + r = dns_packet_read(p, c, ret, NULL); + if (r < 0) + return r; + + if (size) + *size = c; + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +int dns_packet_read_name( + DnsPacket *p, + char **_ret, + bool allow_compression, + size_t *start) { + + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + size_t after_rindex = 0, jump_barrier; + _cleanup_free_ char *ret = NULL; + size_t n = 0, allocated = 0; + bool first = true; + int r; + + assert(p); + assert(_ret); + INIT_REWINDER(rewinder, p); + jump_barrier = p->rindex; + + if (p->refuse_compression) + allow_compression = false; + + for (;;) { + uint8_t c, d; + + r = dns_packet_read_uint8(p, &c, NULL); + if (r < 0) + return r; + + if (c == 0) + /* End of name */ + break; + else if (c <= 63) { + const char *label; + + /* Literal label */ + r = dns_packet_read(p, c, (const void**) &label, NULL); + if (r < 0) + return r; + + if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) + return -ENOMEM; + + if (first) + first = false; + else + ret[n++] = '.'; + + r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); + if (r < 0) + return r; + + n += r; + continue; + } else if (allow_compression && (c & 0xc0) == 0xc0) { + uint16_t ptr; + + /* Pointer */ + r = dns_packet_read_uint8(p, &d, NULL); + if (r < 0) + return r; + + ptr = (uint16_t) (c & ~0xc0) << 8 | (uint16_t) d; + if (ptr < DNS_PACKET_HEADER_SIZE || ptr >= jump_barrier) + return -EBADMSG; + + if (after_rindex == 0) + after_rindex = p->rindex; + + /* Jumps are limited to a "prior occurrence" (RFC-1035 4.1.4) */ + jump_barrier = ptr; + p->rindex = ptr; + } else + return -EBADMSG; + } + + if (!GREEDY_REALLOC(ret, allocated, n + 1)) + return -ENOMEM; + + ret[n] = 0; + + if (after_rindex != 0) + p->rindex= after_rindex; + + *_ret = ret; + ret = NULL; + + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *start) { + uint8_t window; + uint8_t length; + const uint8_t *bitmap; + uint8_t bit = 0; + unsigned i; + bool found = false; + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + int r; + + assert(p); + assert(types); + INIT_REWINDER(rewinder, p); + + r = bitmap_ensure_allocated(types); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &window, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &length, NULL); + if (r < 0) + return r; + + if (length == 0 || length > 32) + return -EBADMSG; + + r = dns_packet_read(p, length, (const void **)&bitmap, NULL); + if (r < 0) + return r; + + for (i = 0; i < length; i++) { + uint8_t bitmask = 1 << 7; + + if (!bitmap[i]) { + found = false; + bit += 8; + continue; + } + + found = true; + + while (bitmask) { + if (bitmap[i] & bitmask) { + uint16_t n; + + n = (uint16_t) window << 8 | (uint16_t) bit; + + /* Ignore pseudo-types. see RFC4034 section 4.1.2 */ + if (dns_type_is_pseudo(n)) + continue; + + r = bitmap_set(*types, n); + if (r < 0) + return r; + } + + bit++; + bitmask >>= 1; + } + } + + if (!found) + return -EBADMSG; + + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +static int dns_packet_read_type_windows(DnsPacket *p, Bitmap **types, size_t size, size_t *start) { + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + int r; + + INIT_REWINDER(rewinder, p); + + while (p->rindex < rewinder.saved_rindex + size) { + r = dns_packet_read_type_window(p, types, NULL); + if (r < 0) + return r; + + /* don't read past end of current RR */ + if (p->rindex > rewinder.saved_rindex + size) + return -EBADMSG; + } + + if (p->rindex != rewinder.saved_rindex + size) + return -EBADMSG; + + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start) { + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + _cleanup_free_ char *name = NULL; + bool cache_flush = false; + uint16_t class, type; + DnsResourceKey *key; + int r; + + assert(p); + assert(ret); + INIT_REWINDER(rewinder, p); + + r = dns_packet_read_name(p, &name, true, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint16(p, &type, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint16(p, &class, NULL); + if (r < 0) + return r; + + if (p->protocol == DNS_PROTOCOL_MDNS) { + /* See RFC6762, Section 10.2 */ + + if (type != DNS_TYPE_OPT && (class & MDNS_RR_CACHE_FLUSH)) { + class &= ~MDNS_RR_CACHE_FLUSH; + cache_flush = true; + } + } + + key = dns_resource_key_new_consume(class, type, name); + if (!key) + return -ENOMEM; + + name = NULL; + *ret = key; + + if (ret_cache_flush) + *ret_cache_flush = cache_flush; + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +static bool loc_size_ok(uint8_t size) { + uint8_t m = size >> 4, e = size & 0xF; + + return m <= 9 && e <= 9 && (m > 0 || e == 0); +} + +int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_flush, size_t *start) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder; + size_t offset; + uint16_t rdlength; + bool cache_flush; + int r; + + assert(p); + assert(ret); + + INIT_REWINDER(rewinder, p); + + r = dns_packet_read_key(p, &key, &cache_flush, NULL); + if (r < 0) + return r; + + if (!dns_class_is_valid_rr(key->class) || !dns_type_is_valid_rr(key->type)) + return -EBADMSG; + + rr = dns_resource_record_new(key); + if (!rr) + return -ENOMEM; + + r = dns_packet_read_uint32(p, &rr->ttl, NULL); + if (r < 0) + return r; + + /* RFC 2181, Section 8, suggests to + * treat a TTL with the MSB set as a zero TTL. */ + if (rr->ttl & UINT32_C(0x80000000)) + rr->ttl = 0; + + r = dns_packet_read_uint16(p, &rdlength, NULL); + if (r < 0) + return r; + + if (p->rindex + rdlength > p->size) + return -EBADMSG; + + offset = p->rindex; + + switch (rr->key->type) { + + case DNS_TYPE_SRV: + r = dns_packet_read_uint16(p, &rr->srv.priority, NULL); + if (r < 0) + return r; + r = dns_packet_read_uint16(p, &rr->srv.weight, NULL); + if (r < 0) + return r; + r = dns_packet_read_uint16(p, &rr->srv.port, NULL); + if (r < 0) + return r; + r = dns_packet_read_name(p, &rr->srv.name, true, NULL); + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + r = dns_packet_read_name(p, &rr->ptr.name, true, NULL); + break; + + case DNS_TYPE_HINFO: + r = dns_packet_read_string(p, &rr->hinfo.cpu, NULL); + if (r < 0) + return r; + + r = dns_packet_read_string(p, &rr->hinfo.os, NULL); + break; + + case DNS_TYPE_SPF: /* exactly the same as TXT */ + case DNS_TYPE_TXT: + if (rdlength <= 0) { + DnsTxtItem *i; + /* RFC 6763, section 6.1 suggests to treat + * empty TXT RRs as equivalent to a TXT record + * with a single empty string. */ + + i = malloc0(offsetof(DnsTxtItem, data) + 1); /* for safety reasons we add an extra NUL byte */ + if (!i) + return -ENOMEM; + + rr->txt.items = i; + } else { + DnsTxtItem *last = NULL; + + while (p->rindex < offset + rdlength) { + DnsTxtItem *i; + const void *data; + size_t sz; + + r = dns_packet_read_raw_string(p, &data, &sz, NULL); + if (r < 0) + return r; + + i = malloc0(offsetof(DnsTxtItem, data) + sz + 1); /* extra NUL byte at the end */ + if (!i) + return -ENOMEM; + + memcpy(i->data, data, sz); + i->length = sz; + + LIST_INSERT_AFTER(items, rr->txt.items, last, i); + last = i; + } + } + + r = 0; + break; + + case DNS_TYPE_A: + r = dns_packet_read_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); + break; + + case DNS_TYPE_AAAA: + r = dns_packet_read_blob(p, &rr->aaaa.in6_addr, sizeof(struct in6_addr), NULL); + break; + + case DNS_TYPE_SOA: + r = dns_packet_read_name(p, &rr->soa.mname, true, NULL); + if (r < 0) + return r; + + r = dns_packet_read_name(p, &rr->soa.rname, true, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->soa.serial, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->soa.refresh, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->soa.retry, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->soa.expire, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->soa.minimum, NULL); + break; + + case DNS_TYPE_MX: + r = dns_packet_read_uint16(p, &rr->mx.priority, NULL); + if (r < 0) + return r; + + r = dns_packet_read_name(p, &rr->mx.exchange, true, NULL); + break; + + case DNS_TYPE_LOC: { + uint8_t t; + size_t pos; + + r = dns_packet_read_uint8(p, &t, &pos); + if (r < 0) + return r; + + if (t == 0) { + rr->loc.version = t; + + r = dns_packet_read_uint8(p, &rr->loc.size, NULL); + if (r < 0) + return r; + + if (!loc_size_ok(rr->loc.size)) + return -EBADMSG; + + r = dns_packet_read_uint8(p, &rr->loc.horiz_pre, NULL); + if (r < 0) + return r; + + if (!loc_size_ok(rr->loc.horiz_pre)) + return -EBADMSG; + + r = dns_packet_read_uint8(p, &rr->loc.vert_pre, NULL); + if (r < 0) + return r; + + if (!loc_size_ok(rr->loc.vert_pre)) + return -EBADMSG; + + r = dns_packet_read_uint32(p, &rr->loc.latitude, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->loc.longitude, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->loc.altitude, NULL); + if (r < 0) + return r; + + break; + } else { + dns_packet_rewind(p, pos); + rr->unparseable = true; + goto unparseable; + } + } + + case DNS_TYPE_DS: + r = dns_packet_read_uint16(p, &rr->ds.key_tag, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->ds.algorithm, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->ds.digest_type, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, rdlength - 4, + &rr->ds.digest, &rr->ds.digest_size, + NULL); + if (r < 0) + return r; + + if (rr->ds.digest_size <= 0) + /* the accepted size depends on the algorithm, but for now + just ensure that the value is greater than zero */ + return -EBADMSG; + + break; + + case DNS_TYPE_SSHFP: + r = dns_packet_read_uint8(p, &rr->sshfp.algorithm, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->sshfp.fptype, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, rdlength - 2, + &rr->sshfp.fingerprint, &rr->sshfp.fingerprint_size, + NULL); + + if (rr->sshfp.fingerprint_size <= 0) + /* the accepted size depends on the algorithm, but for now + just ensure that the value is greater than zero */ + return -EBADMSG; + + break; + + case DNS_TYPE_DNSKEY: + r = dns_packet_read_uint16(p, &rr->dnskey.flags, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->dnskey.protocol, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->dnskey.algorithm, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, rdlength - 4, + &rr->dnskey.key, &rr->dnskey.key_size, + NULL); + + if (rr->dnskey.key_size <= 0) + /* the accepted size depends on the algorithm, but for now + just ensure that the value is greater than zero */ + return -EBADMSG; + + break; + + case DNS_TYPE_RRSIG: + r = dns_packet_read_uint16(p, &rr->rrsig.type_covered, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->rrsig.algorithm, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->rrsig.labels, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->rrsig.original_ttl, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->rrsig.expiration, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint32(p, &rr->rrsig.inception, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint16(p, &rr->rrsig.key_tag, NULL); + if (r < 0) + return r; + + r = dns_packet_read_name(p, &rr->rrsig.signer, false, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, offset + rdlength - p->rindex, + &rr->rrsig.signature, &rr->rrsig.signature_size, + NULL); + + if (rr->rrsig.signature_size <= 0) + /* the accepted size depends on the algorithm, but for now + just ensure that the value is greater than zero */ + return -EBADMSG; + + break; + + case DNS_TYPE_NSEC: { + + /* + * RFC6762, section 18.14 explictly states mDNS should use name compression. + * This contradicts RFC3845, section 2.1.1 + */ + + bool allow_compressed = p->protocol == DNS_PROTOCOL_MDNS; + + r = dns_packet_read_name(p, &rr->nsec.next_domain_name, allow_compressed, NULL); + if (r < 0) + return r; + + r = dns_packet_read_type_windows(p, &rr->nsec.types, offset + rdlength - p->rindex, NULL); + + /* We accept empty NSEC bitmaps. The bit indicating the presence of the NSEC record itself + * is redundant and in e.g., RFC4956 this fact is used to define a use for NSEC records + * without the NSEC bit set. */ + + break; + } + case DNS_TYPE_NSEC3: { + uint8_t size; + + r = dns_packet_read_uint8(p, &rr->nsec3.algorithm, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->nsec3.flags, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint16(p, &rr->nsec3.iterations, NULL); + if (r < 0) + return r; + + /* this may be zero */ + r = dns_packet_read_uint8(p, &size, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, size, &rr->nsec3.salt, &rr->nsec3.salt_size, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &size, NULL); + if (r < 0) + return r; + + if (size <= 0) + return -EBADMSG; + + r = dns_packet_read_memdup(p, size, + &rr->nsec3.next_hashed_name, &rr->nsec3.next_hashed_name_size, + NULL); + if (r < 0) + return r; + + r = dns_packet_read_type_windows(p, &rr->nsec3.types, offset + rdlength - p->rindex, NULL); + + /* empty non-terminals can have NSEC3 records, so empty bitmaps are allowed */ + + break; + } + + case DNS_TYPE_TLSA: + r = dns_packet_read_uint8(p, &rr->tlsa.cert_usage, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->tlsa.selector, NULL); + if (r < 0) + return r; + + r = dns_packet_read_uint8(p, &rr->tlsa.matching_type, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, rdlength - 3, + &rr->tlsa.data, &rr->tlsa.data_size, + NULL); + + if (rr->tlsa.data_size <= 0) + /* the accepted size depends on the algorithm, but for now + just ensure that the value is greater than zero */ + return -EBADMSG; + + break; + + case DNS_TYPE_CAA: + r = dns_packet_read_uint8(p, &rr->caa.flags, NULL); + if (r < 0) + return r; + + r = dns_packet_read_string(p, &rr->caa.tag, NULL); + if (r < 0) + return r; + + r = dns_packet_read_memdup(p, + rdlength + offset - p->rindex, + &rr->caa.value, &rr->caa.value_size, NULL); + + break; + + case DNS_TYPE_OPT: /* we only care about the header of OPT for now. */ + case DNS_TYPE_OPENPGPKEY: + default: + unparseable: + r = dns_packet_read_memdup(p, rdlength, &rr->generic.data, &rr->generic.data_size, NULL); + + break; + } + if (r < 0) + return r; + if (p->rindex != offset + rdlength) + return -EBADMSG; + + *ret = rr; + rr = NULL; + + if (ret_cache_flush) + *ret_cache_flush = cache_flush; + if (start) + *start = rewinder.saved_rindex; + CANCEL_REWINDER(rewinder); + + return 0; +} + +static bool opt_is_good(DnsResourceRecord *rr, bool *rfc6975) { + const uint8_t* p; + bool found_dau_dhu_n3u = false; + size_t l; + + /* Checks whether the specified OPT RR is well-formed and whether it contains RFC6975 data (which is not OK in + * a reply). */ + + assert(rr); + assert(rr->key->type == DNS_TYPE_OPT); + + /* Check that the version is 0 */ + if (((rr->ttl >> 16) & UINT32_C(0xFF)) != 0) { + *rfc6975 = false; + return true; /* if it's not version 0, it's OK, but we will ignore the OPT field contents */ + } + + p = rr->opt.data; + l = rr->opt.data_size; + while (l > 0) { + uint16_t option_code, option_length; + + /* At least four bytes for OPTION-CODE and OPTION-LENGTH are required */ + if (l < 4U) + return false; + + option_code = unaligned_read_be16(p); + option_length = unaligned_read_be16(p + 2); + + if (l < option_length + 4U) + return false; + + /* RFC 6975 DAU, DHU or N3U fields found. */ + if (IN_SET(option_code, 5, 6, 7)) + found_dau_dhu_n3u = true; + + p += option_length + 4U; + l -= option_length + 4U; + } + + *rfc6975 = found_dau_dhu_n3u; + return true; +} + +int dns_packet_extract(DnsPacket *p) { + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = {}; + unsigned n, i; + int r; + + if (p->extracted) + return 0; + + INIT_REWINDER(rewinder, p); + dns_packet_rewind(p, DNS_PACKET_HEADER_SIZE); + + n = DNS_PACKET_QDCOUNT(p); + if (n > 0) { + question = dns_question_new(n); + if (!question) + return -ENOMEM; + + for (i = 0; i < n; i++) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + bool cache_flush; + + r = dns_packet_read_key(p, &key, &cache_flush, NULL); + if (r < 0) + return r; + + if (cache_flush) + return -EBADMSG; + + if (!dns_type_is_valid_query(key->type)) + return -EBADMSG; + + r = dns_question_add(question, key); + if (r < 0) + return r; + } + } + + n = DNS_PACKET_RRCOUNT(p); + if (n > 0) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *previous = NULL; + bool bad_opt = false; + + answer = dns_answer_new(n); + if (!answer) + return -ENOMEM; + + for (i = 0; i < n; i++) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + bool cache_flush = false; + + r = dns_packet_read_rr(p, &rr, &cache_flush, NULL); + if (r < 0) + return r; + + /* Try to reduce memory usage a bit */ + if (previous) + dns_resource_key_reduce(&rr->key, &previous->key); + + if (rr->key->type == DNS_TYPE_OPT) { + bool has_rfc6975; + + if (p->opt || bad_opt) { + /* Multiple OPT RRs? if so, let's ignore all, because there's something wrong + * with the server, and if one is valid we wouldn't know which one. */ + log_debug("Multiple OPT RRs detected, ignoring all."); + bad_opt = true; + continue; + } + + if (!dns_name_is_root(dns_resource_key_name(rr->key))) { + /* If the OPT RR is not owned by the root domain, then it is bad, let's ignore + * it. */ + log_debug("OPT RR is not owned by root domain, ignoring."); + bad_opt = true; + continue; + } + + if (i < DNS_PACKET_ANCOUNT(p) + DNS_PACKET_NSCOUNT(p)) { + /* OPT RR is in the wrong section? Some Belkin routers do this. This is a hint + * the EDNS implementation is borked, like the Belkin one is, hence ignore + * it. */ + log_debug("OPT RR in wrong section, ignoring."); + bad_opt = true; + continue; + } + + if (!opt_is_good(rr, &has_rfc6975)) { + log_debug("Malformed OPT RR, ignoring."); + bad_opt = true; + continue; + } + + if (DNS_PACKET_QR(p)) { + /* Additional checks for responses */ + + if (!DNS_RESOURCE_RECORD_OPT_VERSION_SUPPORTED(rr)) { + /* If this is a reply and we don't know the EDNS version then something + * is weird... */ + log_debug("EDNS version newer that our request, bad server."); + return -EBADMSG; + } + + if (has_rfc6975) { + /* If the OPT RR contains RFC6975 algorithm data, then this is indication that + * the server just copied the OPT it got from us (which contained that data) + * back into the reply. If so, then it doesn't properly support EDNS, as + * RFC6975 makes it very clear that the algorithm data should only be contained + * in questions, never in replies. Crappy Belkin routers copy the OPT data for + * example, hence let's detect this so that we downgrade early. */ + log_debug("OPT RR contained RFC6975 data, ignoring."); + bad_opt = true; + continue; + } + } + + p->opt = dns_resource_record_ref(rr); + } else { + + /* According to RFC 4795, section 2.9. only the RRs from the Answer section shall be + * cached. Hence mark only those RRs as cacheable by default, but not the ones from the + * Additional or Authority sections. */ + + r = dns_answer_add(answer, rr, p->ifindex, + (i < DNS_PACKET_ANCOUNT(p) ? DNS_ANSWER_CACHEABLE : 0) | + (p->protocol == DNS_PROTOCOL_MDNS && !cache_flush ? DNS_ANSWER_SHARED_OWNER : 0)); + if (r < 0) + return r; + } + + /* Remember this RR, so that we potentically can merge it's ->key object with the next RR. Note + * that we only do this if we actually decided to keep the RR around. */ + dns_resource_record_unref(previous); + previous = dns_resource_record_ref(rr); + } + + if (bad_opt) + p->opt = dns_resource_record_unref(p->opt); + } + + p->question = question; + question = NULL; + + p->answer = answer; + answer = NULL; + + p->extracted = true; + + /* no CANCEL, always rewind */ + return 0; +} + +int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key) { + int r; + + assert(p); + assert(key); + + /* Checks if the specified packet is a reply for the specified + * key and the specified key is the only one in the question + * section. */ + + if (DNS_PACKET_QR(p) != 1) + return 0; + + /* Let's unpack the packet, if that hasn't happened yet. */ + r = dns_packet_extract(p); + if (r < 0) + return r; + + if (p->question->n_keys != 1) + return 0; + + return dns_resource_key_equal(p->question->keys[0], key); +} + +static const char* const dns_rcode_table[_DNS_RCODE_MAX_DEFINED] = { + [DNS_RCODE_SUCCESS] = "SUCCESS", + [DNS_RCODE_FORMERR] = "FORMERR", + [DNS_RCODE_SERVFAIL] = "SERVFAIL", + [DNS_RCODE_NXDOMAIN] = "NXDOMAIN", + [DNS_RCODE_NOTIMP] = "NOTIMP", + [DNS_RCODE_REFUSED] = "REFUSED", + [DNS_RCODE_YXDOMAIN] = "YXDOMAIN", + [DNS_RCODE_YXRRSET] = "YRRSET", + [DNS_RCODE_NXRRSET] = "NXRRSET", + [DNS_RCODE_NOTAUTH] = "NOTAUTH", + [DNS_RCODE_NOTZONE] = "NOTZONE", + [DNS_RCODE_BADVERS] = "BADVERS", + [DNS_RCODE_BADKEY] = "BADKEY", + [DNS_RCODE_BADTIME] = "BADTIME", + [DNS_RCODE_BADMODE] = "BADMODE", + [DNS_RCODE_BADNAME] = "BADNAME", + [DNS_RCODE_BADALG] = "BADALG", + [DNS_RCODE_BADTRUNC] = "BADTRUNC", + [DNS_RCODE_BADCOOKIE] = "BADCOOKIE", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_rcode, int); + +static const char* const dns_protocol_table[_DNS_PROTOCOL_MAX] = { + [DNS_PROTOCOL_DNS] = "dns", + [DNS_PROTOCOL_MDNS] = "mdns", + [DNS_PROTOCOL_LLMNR] = "llmnr", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_protocol, DnsProtocol); diff --git a/src/grp-resolve/libbasic-dns/src/resolved-dns-question.c b/src/grp-resolve/libbasic-dns/src/resolved-dns-question.c new file mode 100644 index 0000000000..672ef6207d --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-question.c @@ -0,0 +1,468 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/dns-type.h" +#include "basic-dns/resolved-dns-question.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-shared/dns-domain.h" + +DnsQuestion *dns_question_new(unsigned n) { + DnsQuestion *q; + + assert(n > 0); + + q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n); + if (!q) + return NULL; + + q->n_ref = 1; + q->n_allocated = n; + + return q; +} + +DnsQuestion *dns_question_ref(DnsQuestion *q) { + if (!q) + return NULL; + + assert(q->n_ref > 0); + q->n_ref++; + return q; +} + +DnsQuestion *dns_question_unref(DnsQuestion *q) { + if (!q) + return NULL; + + assert(q->n_ref > 0); + + if (q->n_ref == 1) { + unsigned i; + + for (i = 0; i < q->n_keys; i++) + dns_resource_key_unref(q->keys[i]); + free(q); + } else + q->n_ref--; + + return NULL; +} + +int dns_question_add(DnsQuestion *q, DnsResourceKey *key) { + unsigned i; + int r; + + assert(key); + + if (!q) + return -ENOSPC; + + for (i = 0; i < q->n_keys; i++) { + r = dns_resource_key_equal(q->keys[i], key); + if (r < 0) + return r; + if (r > 0) + return 0; + } + + if (q->n_keys >= q->n_allocated) + return -ENOSPC; + + q->keys[q->n_keys++] = dns_resource_key_ref(key); + return 0; +} + +int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { + unsigned i; + int r; + + assert(rr); + + if (!q) + return 0; + + for (i = 0; i < q->n_keys; i++) { + r = dns_resource_key_match_rr(q->keys[i], rr, search_domain); + if (r != 0) + return r; + } + + return 0; +} + +int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { + unsigned i; + int r; + + assert(rr); + + if (!q) + return 0; + + if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)) + return 0; + + for (i = 0; i < q->n_keys; i++) { + /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */ + if (!dns_type_may_redirect(q->keys[i]->type)) + return 0; + + r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain); + if (r != 0) + return r; + } + + return 0; +} + +int dns_question_is_valid_for_query(DnsQuestion *q) { + const char *name; + unsigned i; + int r; + + if (!q) + return 0; + + if (q->n_keys <= 0) + return 0; + + if (q->n_keys > 65535) + return 0; + + name = dns_resource_key_name(q->keys[0]); + if (!name) + return 0; + + /* Check that all keys in this question bear the same name */ + for (i = 0; i < q->n_keys; i++) { + assert(q->keys[i]); + + if (i > 0) { + r = dns_name_equal(dns_resource_key_name(q->keys[i]), name); + if (r <= 0) + return r; + } + + if (!dns_type_is_valid_query(q->keys[i]->type)) + return 0; + } + + return 1; +} + +int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) { + unsigned j; + int r; + + assert(k); + + if (!a) + return 0; + + for (j = 0; j < a->n_keys; j++) { + r = dns_resource_key_equal(a->keys[j], k); + if (r != 0) + return r; + } + + return 0; +} + +int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { + unsigned j; + int r; + + if (a == b) + return 1; + + if (!a) + return !b || b->n_keys == 0; + if (!b) + return a->n_keys == 0; + + /* Checks if all keys in a are also contained b, and vice versa */ + + for (j = 0; j < a->n_keys; j++) { + r = dns_question_contains(b, a->keys[j]); + if (r <= 0) + return r; + } + + for (j = 0; j < b->n_keys; j++) { + r = dns_question_contains(a, b->keys[j]); + if (r <= 0) + return r; + } + + return 1; +} + +int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { + _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; + DnsResourceKey *key; + bool same = true; + int r; + + assert(cname); + assert(ret); + assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); + + if (dns_question_size(q) <= 0) { + *ret = NULL; + return 0; + } + + DNS_QUESTION_FOREACH(key, q) { + _cleanup_free_ char *destination = NULL; + const char *d; + + if (cname->key->type == DNS_TYPE_CNAME) + d = cname->cname.name; + else { + r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination); + if (r < 0) + return r; + if (r == 0) + continue; + + d = destination; + } + + r = dns_name_equal(dns_resource_key_name(key), d); + if (r < 0) + return r; + + if (r == 0) { + same = false; + break; + } + } + + /* Fully the same, indicate we didn't do a thing */ + if (same) { + *ret = NULL; + return 0; + } + + n = dns_question_new(q->n_keys); + if (!n) + return -ENOMEM; + + /* Create a new question, and patch in the new name */ + DNS_QUESTION_FOREACH(key, q) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; + + k = dns_resource_key_new_redirect(key, cname); + if (!k) + return -ENOMEM; + + r = dns_question_add(n, k); + if (r < 0) + return r; + } + + *ret = n; + n = NULL; + + return 1; +} + +const char *dns_question_first_name(DnsQuestion *q) { + + if (!q) + return NULL; + + if (q->n_keys < 1) + return NULL; + + return dns_resource_key_name(q->keys[0]); +} + +int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) { + _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; + _cleanup_free_ char *buf = NULL; + int r; + + assert(ret); + assert(name); + + if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) + return -EAFNOSUPPORT; + + if (convert_idna) { + r = dns_name_apply_idna(name, &buf); + if (r < 0) + return r; + + name = buf; + } + + q = dns_question_new(family == AF_UNSPEC ? 2 : 1); + if (!q) + return -ENOMEM; + + if (family != AF_INET6) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name); + if (!key) + return -ENOMEM; + + r = dns_question_add(q, key); + if (r < 0) + return r; + } + + if (family != AF_INET) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name); + if (!key) + return -ENOMEM; + + r = dns_question_add(q, key); + if (r < 0) + return r; + } + + *ret = q; + q = NULL; + + return 0; +} + +int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; + _cleanup_free_ char *reverse = NULL; + int r; + + assert(ret); + assert(a); + + if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) + return -EAFNOSUPPORT; + + r = dns_name_reverse(family, a, &reverse); + if (r < 0) + return r; + + q = dns_question_new(1); + if (!q) + return -ENOMEM; + + key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse); + if (!key) + return -ENOMEM; + + reverse = NULL; + + r = dns_question_add(q, key); + if (r < 0) + return r; + + *ret = q; + q = NULL; + + return 0; +} + +int dns_question_new_service( + DnsQuestion **ret, + const char *service, + const char *type, + const char *domain, + bool with_txt, + bool convert_idna) { + + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; + _cleanup_free_ char *buf = NULL, *joined = NULL; + const char *name; + int r; + + assert(ret); + + /* We support three modes of invocation: + * + * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service + * type and possibly a service name. If specified in this way we assume it's already IDNA converted if + * that's necessary. + * + * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD + * style prefix. In this case we'll IDNA convert the domain, if that's requested. + * + * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put + * together. The service name is never IDNA converted, and the domain is if requested. + * + * It's not supported to specify a service name without a type, or no domain name. + */ + + if (!domain) + return -EINVAL; + + if (type) { + if (convert_idna) { + r = dns_name_apply_idna(domain, &buf); + if (r < 0) + return r; + + domain = buf; + } + + r = dns_service_join(service, type, domain, &joined); + if (r < 0) + return r; + + name = joined; + } else { + if (service) + return -EINVAL; + + name = domain; + } + + q = dns_question_new(1 + with_txt); + if (!q) + return -ENOMEM; + + key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name); + if (!key) + return -ENOMEM; + + r = dns_question_add(q, key); + if (r < 0) + return r; + + if (with_txt) { + dns_resource_key_unref(key); + key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name); + if (!key) + return -ENOMEM; + + r = dns_question_add(q, key); + if (r < 0) + return r; + } + + *ret = q; + q = NULL; + + return 0; +} diff --git a/src/grp-resolve/libbasic-dns/src/resolved-dns-rr.c b/src/grp-resolve/libbasic-dns/src/resolved-dns-rr.c new file mode 100644 index 0000000000..c6ec81ead6 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-rr.c @@ -0,0 +1,1835 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <math.h> + +#include "basic-dns/dns-type.h" +#include "basic-dns/resolved-dns-dnssec.h" +#include "basic-dns/resolved-dns-packet.h" +#include "basic-dns/resolved-dns-rr.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/escape.h" +#include "systemd-basic/hexdecoct.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/terminal-util.h" +#include "systemd-shared/dns-domain.h" + +DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name) { + DnsResourceKey *k; + size_t l; + + assert(name); + + l = strlen(name); + k = malloc0(sizeof(DnsResourceKey) + l + 1); + if (!k) + return NULL; + + k->n_ref = 1; + k->class = class; + k->type = type; + + strcpy((char*) k + sizeof(DnsResourceKey), name); + + return k; +} + +DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname) { + int r; + + assert(key); + assert(cname); + + assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); + + if (cname->key->type == DNS_TYPE_CNAME) + return dns_resource_key_new(key->class, key->type, cname->cname.name); + else { + DnsResourceKey *k; + char *destination = NULL; + + r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination); + if (r < 0) + return NULL; + if (r == 0) + return dns_resource_key_ref((DnsResourceKey*) key); + + k = dns_resource_key_new_consume(key->class, key->type, destination); + if (!k) + return mfree(destination); + + return k; + } +} + +int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name) { + DnsResourceKey *new_key; + char *joined; + int r; + + assert(ret); + assert(key); + assert(name); + + if (dns_name_is_root(name)) { + *ret = dns_resource_key_ref(key); + return 0; + } + + r = dns_name_concat(dns_resource_key_name(key), name, &joined); + if (r < 0) + return r; + + new_key = dns_resource_key_new_consume(key->class, key->type, joined); + if (!new_key) { + free(joined); + return -ENOMEM; + } + + *ret = new_key; + return 0; +} + +DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name) { + DnsResourceKey *k; + + assert(name); + + k = new0(DnsResourceKey, 1); + if (!k) + return NULL; + + k->n_ref = 1; + k->class = class; + k->type = type; + k->_name = name; + + return k; +} + +DnsResourceKey* dns_resource_key_ref(DnsResourceKey *k) { + + if (!k) + return NULL; + + /* Static/const keys created with DNS_RESOURCE_KEY_CONST will + * set this to -1, they should not be reffed/unreffed */ + assert(k->n_ref != (unsigned) -1); + + assert(k->n_ref > 0); + k->n_ref++; + + return k; +} + +DnsResourceKey* dns_resource_key_unref(DnsResourceKey *k) { + if (!k) + return NULL; + + assert(k->n_ref != (unsigned) -1); + assert(k->n_ref > 0); + + if (k->n_ref == 1) { + free(k->_name); + free(k); + } else + k->n_ref--; + + return NULL; +} + +const char* dns_resource_key_name(const DnsResourceKey *key) { + const char *name; + + if (!key) + return NULL; + + if (key->_name) + name = key->_name; + else + name = (char*) key + sizeof(DnsResourceKey); + + if (dns_name_is_root(name)) + return "."; + else + return name; +} + +bool dns_resource_key_is_address(const DnsResourceKey *key) { + assert(key); + + /* Check if this is an A or AAAA resource key */ + + return key->class == DNS_CLASS_IN && IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_AAAA); +} + +int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b) { + int r; + + if (a == b) + return 1; + + r = dns_name_equal(dns_resource_key_name(a), dns_resource_key_name(b)); + if (r <= 0) + return r; + + if (a->class != b->class) + return 0; + + if (a->type != b->type) + return 0; + + return 1; +} + +int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain) { + int r; + + assert(key); + assert(rr); + + if (key == rr->key) + return 1; + + /* Checks if an rr matches the specified key. If a search + * domain is specified, it will also be checked if the key + * with the search domain suffixed might match the RR. */ + + if (rr->key->class != key->class && key->class != DNS_CLASS_ANY) + return 0; + + if (rr->key->type != key->type && key->type != DNS_TYPE_ANY) + return 0; + + r = dns_name_equal(dns_resource_key_name(rr->key), dns_resource_key_name(key)); + if (r != 0) + return r; + + if (search_domain) { + _cleanup_free_ char *joined = NULL; + + r = dns_name_concat(dns_resource_key_name(key), search_domain, &joined); + if (r < 0) + return r; + + return dns_name_equal(dns_resource_key_name(rr->key), joined); + } + + return 0; +} + +int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain) { + int r; + + assert(key); + assert(cname); + + if (cname->class != key->class && key->class != DNS_CLASS_ANY) + return 0; + + if (cname->type == DNS_TYPE_CNAME) + r = dns_name_equal(dns_resource_key_name(key), dns_resource_key_name(cname)); + else if (cname->type == DNS_TYPE_DNAME) + r = dns_name_endswith(dns_resource_key_name(key), dns_resource_key_name(cname)); + else + return 0; + + if (r != 0) + return r; + + if (search_domain) { + _cleanup_free_ char *joined = NULL; + + r = dns_name_concat(dns_resource_key_name(key), search_domain, &joined); + if (r < 0) + return r; + + if (cname->type == DNS_TYPE_CNAME) + return dns_name_equal(joined, dns_resource_key_name(cname)); + else if (cname->type == DNS_TYPE_DNAME) + return dns_name_endswith(joined, dns_resource_key_name(cname)); + } + + return 0; +} + +int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa) { + assert(soa); + assert(key); + + /* Checks whether 'soa' is a SOA record for the specified key. */ + + if (soa->class != key->class) + return 0; + + if (soa->type != DNS_TYPE_SOA) + return 0; + + return dns_name_endswith(dns_resource_key_name(key), dns_resource_key_name(soa)); +} + +static void dns_resource_key_hash_func(const void *i, struct siphash *state) { + const DnsResourceKey *k = i; + + assert(k); + + dns_name_hash_func(dns_resource_key_name(k), state); + siphash24_compress(&k->class, sizeof(k->class), state); + siphash24_compress(&k->type, sizeof(k->type), state); +} + +static int dns_resource_key_compare_func(const void *a, const void *b) { + const DnsResourceKey *x = a, *y = b; + int ret; + + ret = dns_name_compare_func(dns_resource_key_name(x), dns_resource_key_name(y)); + if (ret != 0) + return ret; + + if (x->type < y->type) + return -1; + if (x->type > y->type) + return 1; + + if (x->class < y->class) + return -1; + if (x->class > y->class) + return 1; + + return 0; +} + +const struct hash_ops dns_resource_key_hash_ops = { + .hash = dns_resource_key_hash_func, + .compare = dns_resource_key_compare_func +}; + +char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size) { + const char *c, *t; + char *ans = buf; + + /* If we cannot convert the CLASS/TYPE into a known string, + use the format recommended by RFC 3597, Section 5. */ + + c = dns_class_to_string(key->class); + t = dns_type_to_string(key->type); + + snprintf(buf, buf_size, "%s %s%s%.0u %s%s%.0u", + dns_resource_key_name(key), + c ?: "", c ? "" : "CLASS", c ? 0 : key->class, + t ?: "", t ? "" : "TYPE", t ? 0 : key->class); + + return ans; +} + +bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b) { + assert(a); + assert(b); + + /* Try to replace one RR key by another if they are identical, thus saving a bit of memory. Note that we do + * this only for RR keys, not for RRs themselves, as they carry a lot of additional metadata (where they come + * from, validity data, and suchlike), and cannot be replaced so easily by other RRs that have the same + * superficial data. */ + + if (!*a) + return false; + if (!*b) + return false; + + /* We refuse merging const keys */ + if ((*a)->n_ref == (unsigned) -1) + return false; + if ((*b)->n_ref == (unsigned) -1) + return false; + + /* Already the same? */ + if (*a == *b) + return true; + + /* Are they really identical? */ + if (dns_resource_key_equal(*a, *b) <= 0) + return false; + + /* Keep the one which already has more references. */ + if ((*a)->n_ref > (*b)->n_ref) { + dns_resource_key_unref(*b); + *b = dns_resource_key_ref(*a); + } else { + dns_resource_key_unref(*a); + *a = dns_resource_key_ref(*b); + } + + return true; +} + +DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key) { + DnsResourceRecord *rr; + + rr = new0(DnsResourceRecord, 1); + if (!rr) + return NULL; + + rr->n_ref = 1; + rr->key = dns_resource_key_ref(key); + rr->expiry = USEC_INFINITY; + rr->n_skip_labels_signer = rr->n_skip_labels_source = (unsigned) -1; + + return rr; +} + +DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + key = dns_resource_key_new(class, type, name); + if (!key) + return NULL; + + return dns_resource_record_new(key); +} + +DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr) { + if (!rr) + return NULL; + + assert(rr->n_ref > 0); + rr->n_ref++; + + return rr; +} + +DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) { + if (!rr) + return NULL; + + assert(rr->n_ref > 0); + + if (rr->n_ref > 1) { + rr->n_ref--; + return NULL; + } + + if (rr->key) { + switch(rr->key->type) { + + case DNS_TYPE_SRV: + free(rr->srv.name); + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + free(rr->ptr.name); + break; + + case DNS_TYPE_HINFO: + free(rr->hinfo.cpu); + free(rr->hinfo.os); + break; + + case DNS_TYPE_TXT: + case DNS_TYPE_SPF: + dns_txt_item_free_all(rr->txt.items); + break; + + case DNS_TYPE_SOA: + free(rr->soa.mname); + free(rr->soa.rname); + break; + + case DNS_TYPE_MX: + free(rr->mx.exchange); + break; + + case DNS_TYPE_DS: + free(rr->ds.digest); + break; + + case DNS_TYPE_SSHFP: + free(rr->sshfp.fingerprint); + break; + + case DNS_TYPE_DNSKEY: + free(rr->dnskey.key); + break; + + case DNS_TYPE_RRSIG: + free(rr->rrsig.signer); + free(rr->rrsig.signature); + break; + + case DNS_TYPE_NSEC: + free(rr->nsec.next_domain_name); + bitmap_free(rr->nsec.types); + break; + + case DNS_TYPE_NSEC3: + free(rr->nsec3.next_hashed_name); + free(rr->nsec3.salt); + bitmap_free(rr->nsec3.types); + break; + + case DNS_TYPE_LOC: + case DNS_TYPE_A: + case DNS_TYPE_AAAA: + break; + + case DNS_TYPE_TLSA: + free(rr->tlsa.data); + break; + + case DNS_TYPE_CAA: + free(rr->caa.tag); + free(rr->caa.value); + break; + + case DNS_TYPE_OPENPGPKEY: + default: + free(rr->generic.data); + } + + free(rr->wire_format); + dns_resource_key_unref(rr->key); + } + + free(rr->to_string); + return mfree(rr); +} + +int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *hostname) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_free_ char *ptr = NULL; + int r; + + assert(ret); + assert(address); + assert(hostname); + + r = dns_name_reverse(family, address, &ptr); + if (r < 0) + return r; + + key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, ptr); + if (!key) + return -ENOMEM; + + ptr = NULL; + + rr = dns_resource_record_new(key); + if (!rr) + return -ENOMEM; + + rr->ptr.name = strdup(hostname); + if (!rr->ptr.name) + return -ENOMEM; + + *ret = rr; + rr = NULL; + + return 0; +} + +int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name) { + DnsResourceRecord *rr; + + assert(ret); + assert(address); + assert(family); + + if (family == AF_INET) { + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, name); + if (!rr) + return -ENOMEM; + + rr->a.in_addr = address->in; + + } else if (family == AF_INET6) { + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, name); + if (!rr) + return -ENOMEM; + + rr->aaaa.in6_addr = address->in6; + } else + return -EAFNOSUPPORT; + + *ret = rr; + + return 0; +} + +#define FIELD_EQUAL(a, b, field) \ + ((a).field ## _size == (b).field ## _size && \ + memcmp((a).field, (b).field, (a).field ## _size) == 0) + +int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b) { + int r; + + assert(a); + assert(b); + + if (a == b) + return 1; + + r = dns_resource_key_equal(a->key, b->key); + if (r <= 0) + return r; + + if (a->unparseable != b->unparseable) + return 0; + + switch (a->unparseable ? _DNS_TYPE_INVALID : a->key->type) { + + case DNS_TYPE_SRV: + r = dns_name_equal(a->srv.name, b->srv.name); + if (r <= 0) + return r; + + return a->srv.priority == b->srv.priority && + a->srv.weight == b->srv.weight && + a->srv.port == b->srv.port; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + return dns_name_equal(a->ptr.name, b->ptr.name); + + case DNS_TYPE_HINFO: + return strcaseeq(a->hinfo.cpu, b->hinfo.cpu) && + strcaseeq(a->hinfo.os, b->hinfo.os); + + case DNS_TYPE_SPF: /* exactly the same as TXT */ + case DNS_TYPE_TXT: + return dns_txt_item_equal(a->txt.items, b->txt.items); + + case DNS_TYPE_A: + return memcmp(&a->a.in_addr, &b->a.in_addr, sizeof(struct in_addr)) == 0; + + case DNS_TYPE_AAAA: + return memcmp(&a->aaaa.in6_addr, &b->aaaa.in6_addr, sizeof(struct in6_addr)) == 0; + + case DNS_TYPE_SOA: + r = dns_name_equal(a->soa.mname, b->soa.mname); + if (r <= 0) + return r; + r = dns_name_equal(a->soa.rname, b->soa.rname); + if (r <= 0) + return r; + + return a->soa.serial == b->soa.serial && + a->soa.refresh == b->soa.refresh && + a->soa.retry == b->soa.retry && + a->soa.expire == b->soa.expire && + a->soa.minimum == b->soa.minimum; + + case DNS_TYPE_MX: + if (a->mx.priority != b->mx.priority) + return 0; + + return dns_name_equal(a->mx.exchange, b->mx.exchange); + + case DNS_TYPE_LOC: + assert(a->loc.version == b->loc.version); + + return a->loc.size == b->loc.size && + a->loc.horiz_pre == b->loc.horiz_pre && + a->loc.vert_pre == b->loc.vert_pre && + a->loc.latitude == b->loc.latitude && + a->loc.longitude == b->loc.longitude && + a->loc.altitude == b->loc.altitude; + + case DNS_TYPE_DS: + return a->ds.key_tag == b->ds.key_tag && + a->ds.algorithm == b->ds.algorithm && + a->ds.digest_type == b->ds.digest_type && + FIELD_EQUAL(a->ds, b->ds, digest); + + case DNS_TYPE_SSHFP: + return a->sshfp.algorithm == b->sshfp.algorithm && + a->sshfp.fptype == b->sshfp.fptype && + FIELD_EQUAL(a->sshfp, b->sshfp, fingerprint); + + case DNS_TYPE_DNSKEY: + return a->dnskey.flags == b->dnskey.flags && + a->dnskey.protocol == b->dnskey.protocol && + a->dnskey.algorithm == b->dnskey.algorithm && + FIELD_EQUAL(a->dnskey, b->dnskey, key); + + case DNS_TYPE_RRSIG: + /* do the fast comparisons first */ + return a->rrsig.type_covered == b->rrsig.type_covered && + a->rrsig.algorithm == b->rrsig.algorithm && + a->rrsig.labels == b->rrsig.labels && + a->rrsig.original_ttl == b->rrsig.original_ttl && + a->rrsig.expiration == b->rrsig.expiration && + a->rrsig.inception == b->rrsig.inception && + a->rrsig.key_tag == b->rrsig.key_tag && + FIELD_EQUAL(a->rrsig, b->rrsig, signature) && + dns_name_equal(a->rrsig.signer, b->rrsig.signer); + + case DNS_TYPE_NSEC: + return dns_name_equal(a->nsec.next_domain_name, b->nsec.next_domain_name) && + bitmap_equal(a->nsec.types, b->nsec.types); + + case DNS_TYPE_NSEC3: + return a->nsec3.algorithm == b->nsec3.algorithm && + a->nsec3.flags == b->nsec3.flags && + a->nsec3.iterations == b->nsec3.iterations && + FIELD_EQUAL(a->nsec3, b->nsec3, salt) && + FIELD_EQUAL(a->nsec3, b->nsec3, next_hashed_name) && + bitmap_equal(a->nsec3.types, b->nsec3.types); + + case DNS_TYPE_TLSA: + return a->tlsa.cert_usage == b->tlsa.cert_usage && + a->tlsa.selector == b->tlsa.selector && + a->tlsa.matching_type == b->tlsa.matching_type && + FIELD_EQUAL(a->tlsa, b->tlsa, data); + + case DNS_TYPE_CAA: + return a->caa.flags == b->caa.flags && + streq(a->caa.tag, b->caa.tag) && + FIELD_EQUAL(a->caa, b->caa, value); + + case DNS_TYPE_OPENPGPKEY: + default: + return FIELD_EQUAL(a->generic, b->generic, data); + } +} + +static char* format_location(uint32_t latitude, uint32_t longitude, uint32_t altitude, + uint8_t size, uint8_t horiz_pre, uint8_t vert_pre) { + char *s; + char NS = latitude >= 1U<<31 ? 'N' : 'S'; + char EW = longitude >= 1U<<31 ? 'E' : 'W'; + + int lat = latitude >= 1U<<31 ? (int) (latitude - (1U<<31)) : (int) ((1U<<31) - latitude); + int lon = longitude >= 1U<<31 ? (int) (longitude - (1U<<31)) : (int) ((1U<<31) - longitude); + double alt = altitude >= 10000000u ? altitude - 10000000u : -(double)(10000000u - altitude); + double siz = (size >> 4) * exp10((double) (size & 0xF)); + double hor = (horiz_pre >> 4) * exp10((double) (horiz_pre & 0xF)); + double ver = (vert_pre >> 4) * exp10((double) (vert_pre & 0xF)); + + if (asprintf(&s, "%d %d %.3f %c %d %d %.3f %c %.2fm %.2fm %.2fm %.2fm", + (lat / 60000 / 60), + (lat / 60000) % 60, + (lat % 60000) / 1000., + NS, + (lon / 60000 / 60), + (lon / 60000) % 60, + (lon % 60000) / 1000., + EW, + alt / 100., + siz / 100., + hor / 100., + ver / 100.) < 0) + return NULL; + + return s; +} + +static int format_timestamp_dns(char *buf, size_t l, time_t sec) { + struct tm tm; + + assert(buf); + assert(l > strlen("YYYYMMDDHHmmSS")); + + if (!gmtime_r(&sec, &tm)) + return -EINVAL; + + if (strftime(buf, l, "%Y%m%d%H%M%S", &tm) <= 0) + return -EINVAL; + + return 0; +} + +static char *format_types(Bitmap *types) { + _cleanup_strv_free_ char **strv = NULL; + _cleanup_free_ char *str = NULL; + Iterator i; + unsigned type; + int r; + + BITMAP_FOREACH(type, types, i) { + if (dns_type_to_string(type)) { + r = strv_extend(&strv, dns_type_to_string(type)); + if (r < 0) + return NULL; + } else { + char *t; + + r = asprintf(&t, "TYPE%u", type); + if (r < 0) + return NULL; + + r = strv_consume(&strv, t); + if (r < 0) + return NULL; + } + } + + str = strv_join(strv, " "); + if (!str) + return NULL; + + return strjoin("( ", str, " )", NULL); +} + +static char *format_txt(DnsTxtItem *first) { + DnsTxtItem *i; + size_t c = 1; + char *p, *s; + + LIST_FOREACH(items, i, first) + c += i->length * 4 + 3; + + p = s = new(char, c); + if (!s) + return NULL; + + LIST_FOREACH(items, i, first) { + size_t j; + + if (i != first) + *(p++) = ' '; + + *(p++) = '"'; + + for (j = 0; j < i->length; j++) { + if (i->data[j] < ' ' || i->data[j] == '"' || i->data[j] >= 127) { + *(p++) = '\\'; + *(p++) = '0' + (i->data[j] / 100); + *(p++) = '0' + ((i->data[j] / 10) % 10); + *(p++) = '0' + (i->data[j] % 10); + } else + *(p++) = i->data[j]; + } + + *(p++) = '"'; + } + + *p = 0; + return s; +} + +const char *dns_resource_record_to_string(DnsResourceRecord *rr) { + _cleanup_free_ char *t = NULL; + char *s, k[DNS_RESOURCE_KEY_STRING_MAX]; + int r; + + assert(rr); + + if (rr->to_string) + return rr->to_string; + + dns_resource_key_to_string(rr->key, k, sizeof(k)); + + switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { + + case DNS_TYPE_SRV: + r = asprintf(&s, "%s %u %u %u %s", + k, + rr->srv.priority, + rr->srv.weight, + rr->srv.port, + strna(rr->srv.name)); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + s = strjoin(k, " ", rr->ptr.name, NULL); + if (!s) + return NULL; + + break; + + case DNS_TYPE_HINFO: + s = strjoin(k, " ", rr->hinfo.cpu, " ", rr->hinfo.os, NULL); + if (!s) + return NULL; + break; + + case DNS_TYPE_SPF: /* exactly the same as TXT */ + case DNS_TYPE_TXT: + t = format_txt(rr->txt.items); + if (!t) + return NULL; + + s = strjoin(k, " ", t, NULL); + if (!s) + return NULL; + break; + + case DNS_TYPE_A: { + _cleanup_free_ char *x = NULL; + + r = in_addr_to_string(AF_INET, (const union in_addr_union*) &rr->a.in_addr, &x); + if (r < 0) + return NULL; + + s = strjoin(k, " ", x, NULL); + if (!s) + return NULL; + break; + } + + case DNS_TYPE_AAAA: + r = in_addr_to_string(AF_INET6, (const union in_addr_union*) &rr->aaaa.in6_addr, &t); + if (r < 0) + return NULL; + + s = strjoin(k, " ", t, NULL); + if (!s) + return NULL; + break; + + case DNS_TYPE_SOA: + r = asprintf(&s, "%s %s %s %u %u %u %u %u", + k, + strna(rr->soa.mname), + strna(rr->soa.rname), + rr->soa.serial, + rr->soa.refresh, + rr->soa.retry, + rr->soa.expire, + rr->soa.minimum); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_MX: + r = asprintf(&s, "%s %u %s", + k, + rr->mx.priority, + rr->mx.exchange); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_LOC: + assert(rr->loc.version == 0); + + t = format_location(rr->loc.latitude, + rr->loc.longitude, + rr->loc.altitude, + rr->loc.size, + rr->loc.horiz_pre, + rr->loc.vert_pre); + if (!t) + return NULL; + + s = strjoin(k, " ", t, NULL); + if (!s) + return NULL; + break; + + case DNS_TYPE_DS: + t = hexmem(rr->ds.digest, rr->ds.digest_size); + if (!t) + return NULL; + + r = asprintf(&s, "%s %u %u %u %s", + k, + rr->ds.key_tag, + rr->ds.algorithm, + rr->ds.digest_type, + t); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_SSHFP: + t = hexmem(rr->sshfp.fingerprint, rr->sshfp.fingerprint_size); + if (!t) + return NULL; + + r = asprintf(&s, "%s %u %u %s", + k, + rr->sshfp.algorithm, + rr->sshfp.fptype, + t); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_DNSKEY: { + _cleanup_free_ char *alg = NULL; + char *ss; + int n; + uint16_t key_tag; + + key_tag = dnssec_keytag(rr, true); + + r = dnssec_algorithm_to_string_alloc(rr->dnskey.algorithm, &alg); + if (r < 0) + return NULL; + + r = asprintf(&s, "%s %u %u %s %n", + k, + rr->dnskey.flags, + rr->dnskey.protocol, + alg, + &n); + if (r < 0) + return NULL; + + r = base64_append(&s, n, + rr->dnskey.key, rr->dnskey.key_size, + 8, columns()); + if (r < 0) + return NULL; + + r = asprintf(&ss, "%s\n" + " -- Flags:%s%s%s\n" + " -- Key tag: %u", + s, + rr->dnskey.flags & DNSKEY_FLAG_SEP ? " SEP" : "", + rr->dnskey.flags & DNSKEY_FLAG_REVOKE ? " REVOKE" : "", + rr->dnskey.flags & DNSKEY_FLAG_ZONE_KEY ? " ZONE_KEY" : "", + key_tag); + if (r < 0) + return NULL; + free(s); + s = ss; + + break; + } + + case DNS_TYPE_RRSIG: { + _cleanup_free_ char *alg = NULL; + char expiration[strlen("YYYYMMDDHHmmSS") + 1], inception[strlen("YYYYMMDDHHmmSS") + 1]; + const char *type; + int n; + + type = dns_type_to_string(rr->rrsig.type_covered); + + r = dnssec_algorithm_to_string_alloc(rr->rrsig.algorithm, &alg); + if (r < 0) + return NULL; + + r = format_timestamp_dns(expiration, sizeof(expiration), rr->rrsig.expiration); + if (r < 0) + return NULL; + + r = format_timestamp_dns(inception, sizeof(inception), rr->rrsig.inception); + if (r < 0) + return NULL; + + /* TYPE?? follows + * http://tools.ietf.org/html/rfc3597#section-5 */ + + r = asprintf(&s, "%s %s%.*u %s %u %u %s %s %u %s %n", + k, + type ?: "TYPE", + type ? 0 : 1, type ? 0u : (unsigned) rr->rrsig.type_covered, + alg, + rr->rrsig.labels, + rr->rrsig.original_ttl, + expiration, + inception, + rr->rrsig.key_tag, + rr->rrsig.signer, + &n); + if (r < 0) + return NULL; + + r = base64_append(&s, n, + rr->rrsig.signature, rr->rrsig.signature_size, + 8, columns()); + if (r < 0) + return NULL; + + break; + } + + case DNS_TYPE_NSEC: + t = format_types(rr->nsec.types); + if (!t) + return NULL; + + r = asprintf(&s, "%s %s %s", + k, + rr->nsec.next_domain_name, + t); + if (r < 0) + return NULL; + break; + + case DNS_TYPE_NSEC3: { + _cleanup_free_ char *salt = NULL, *hash = NULL; + + if (rr->nsec3.salt_size > 0) { + salt = hexmem(rr->nsec3.salt, rr->nsec3.salt_size); + if (!salt) + return NULL; + } + + hash = base32hexmem(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, false); + if (!hash) + return NULL; + + t = format_types(rr->nsec3.types); + if (!t) + return NULL; + + r = asprintf(&s, "%s %"PRIu8" %"PRIu8" %"PRIu16" %s %s %s", + k, + rr->nsec3.algorithm, + rr->nsec3.flags, + rr->nsec3.iterations, + rr->nsec3.salt_size > 0 ? salt : "-", + hash, + t); + if (r < 0) + return NULL; + + break; + } + + case DNS_TYPE_TLSA: { + const char *cert_usage, *selector, *matching_type; + + cert_usage = tlsa_cert_usage_to_string(rr->tlsa.cert_usage); + selector = tlsa_selector_to_string(rr->tlsa.selector); + matching_type = tlsa_matching_type_to_string(rr->tlsa.matching_type); + + t = hexmem(rr->sshfp.fingerprint, rr->sshfp.fingerprint_size); + if (!t) + return NULL; + + r = asprintf(&s, + "%s %u %u %u %s\n" + " -- Cert. usage: %s\n" + " -- Selector: %s\n" + " -- Matching type: %s", + k, + rr->tlsa.cert_usage, + rr->tlsa.selector, + rr->tlsa.matching_type, + t, + cert_usage, + selector, + matching_type); + if (r < 0) + return NULL; + + break; + } + + case DNS_TYPE_CAA: { + _cleanup_free_ char *value; + + value = octescape(rr->caa.value, rr->caa.value_size); + if (!value) + return NULL; + + r = asprintf(&s, "%s %u %s \"%s\"%s%s%s%.0u", + k, + rr->caa.flags, + rr->caa.tag, + value, + rr->caa.flags ? "\n -- Flags:" : "", + rr->caa.flags & CAA_FLAG_CRITICAL ? " critical" : "", + rr->caa.flags & ~CAA_FLAG_CRITICAL ? " " : "", + rr->caa.flags & ~CAA_FLAG_CRITICAL); + if (r < 0) + return NULL; + + break; + } + + case DNS_TYPE_OPENPGPKEY: { + int n; + + r = asprintf(&s, "%s %n", + k, + &n); + if (r < 0) + return NULL; + + r = base64_append(&s, n, + rr->generic.data, rr->generic.data_size, + 8, columns()); + if (r < 0) + return NULL; + break; + } + + default: + t = hexmem(rr->generic.data, rr->generic.data_size); + if (!t) + return NULL; + + /* Format as documented in RFC 3597, Section 5 */ + r = asprintf(&s, "%s \\# %zu %s", k, rr->generic.data_size, t); + if (r < 0) + return NULL; + break; + } + + rr->to_string = s; + return s; +} + +ssize_t dns_resource_record_payload(DnsResourceRecord *rr, void **out) { + assert(rr); + assert(out); + + switch(rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { + case DNS_TYPE_SRV: + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + case DNS_TYPE_HINFO: + case DNS_TYPE_SPF: + case DNS_TYPE_TXT: + case DNS_TYPE_A: + case DNS_TYPE_AAAA: + case DNS_TYPE_SOA: + case DNS_TYPE_MX: + case DNS_TYPE_LOC: + case DNS_TYPE_DS: + case DNS_TYPE_DNSKEY: + case DNS_TYPE_RRSIG: + case DNS_TYPE_NSEC: + case DNS_TYPE_NSEC3: + return -EINVAL; + + case DNS_TYPE_SSHFP: + *out = rr->sshfp.fingerprint; + return rr->sshfp.fingerprint_size; + + case DNS_TYPE_TLSA: + *out = rr->tlsa.data; + return rr->tlsa.data_size; + + + case DNS_TYPE_OPENPGPKEY: + default: + *out = rr->generic.data; + return rr->generic.data_size; + } +} + +int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical) { + + DnsPacket packet = { + .n_ref = 1, + .protocol = DNS_PROTOCOL_DNS, + .on_stack = true, + .refuse_compression = true, + .canonical_form = canonical, + }; + + size_t start, rds; + int r; + + assert(rr); + + /* Generates the RR in wire-format, optionally in the + * canonical form as discussed in the DNSSEC RFC 4034, Section + * 6.2. We allocate a throw-away DnsPacket object on the stack + * here, because we need some book-keeping for memory + * management, and can reuse the DnsPacket serializer, that + * can generate the canonical form, too, but also knows label + * compression and suchlike. */ + + if (rr->wire_format && rr->wire_format_canonical == canonical) + return 0; + + r = dns_packet_append_rr(&packet, rr, &start, &rds); + if (r < 0) + return r; + + assert(start == 0); + assert(packet._data); + + free(rr->wire_format); + rr->wire_format = packet._data; + rr->wire_format_size = packet.size; + rr->wire_format_rdata_offset = rds; + rr->wire_format_canonical = canonical; + + packet._data = NULL; + dns_packet_unref(&packet); + + return 0; +} + +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; + + assert(rr); + assert(ret); + + /* Returns the RRset's signer, if it is known. */ + + if (rr->n_skip_labels_signer == (unsigned) -1) + return -ENODATA; + + n = dns_resource_key_name(rr->key); + r = dns_name_skip(n, rr->n_skip_labels_signer, &n); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + *ret = n; + return 0; +} + +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; + + assert(rr); + assert(ret); + + /* Returns the RRset's synthesizing source, if it is known. */ + + if (rr->n_skip_labels_source == (unsigned) -1) + return -ENODATA; + + n = dns_resource_key_name(rr->key); + r = dns_name_skip(n, rr->n_skip_labels_source, &n); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + *ret = n; + return 0; +} + +int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone) { + const char *signer; + int r; + + assert(rr); + + r = dns_resource_record_signer(rr, &signer); + if (r < 0) + return r; + + return dns_name_equal(zone, signer); +} + +int dns_resource_record_is_synthetic(DnsResourceRecord *rr) { + int r; + + assert(rr); + + /* Returns > 0 if the RR is generated from a wildcard, and is not the asterisk name itself */ + + if (rr->n_skip_labels_source == (unsigned) -1) + return -ENODATA; + + if (rr->n_skip_labels_source == 0) + return 0; + + if (rr->n_skip_labels_source > 1) + return 1; + + r = dns_name_startswith(dns_resource_key_name(rr->key), "*"); + if (r < 0) + return r; + + return !r; +} + +void dns_resource_record_hash_func(const void *i, struct siphash *state) { + const DnsResourceRecord *rr = i; + + assert(rr); + + dns_resource_key_hash_func(rr->key, state); + + switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { + + case DNS_TYPE_SRV: + siphash24_compress(&rr->srv.priority, sizeof(rr->srv.priority), state); + siphash24_compress(&rr->srv.weight, sizeof(rr->srv.weight), state); + siphash24_compress(&rr->srv.port, sizeof(rr->srv.port), state); + dns_name_hash_func(rr->srv.name, state); + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + dns_name_hash_func(rr->ptr.name, state); + break; + + case DNS_TYPE_HINFO: + string_hash_func(rr->hinfo.cpu, state); + string_hash_func(rr->hinfo.os, state); + break; + + case DNS_TYPE_TXT: + case DNS_TYPE_SPF: { + DnsTxtItem *j; + + LIST_FOREACH(items, j, rr->txt.items) { + siphash24_compress(j->data, j->length, state); + + /* Add an extra NUL byte, so that "a" followed by "b" doesn't result in the same hash as "ab" + * followed by "". */ + siphash24_compress_byte(0, state); + } + break; + } + + case DNS_TYPE_A: + siphash24_compress(&rr->a.in_addr, sizeof(rr->a.in_addr), state); + break; + + case DNS_TYPE_AAAA: + siphash24_compress(&rr->aaaa.in6_addr, sizeof(rr->aaaa.in6_addr), state); + break; + + case DNS_TYPE_SOA: + dns_name_hash_func(rr->soa.mname, state); + dns_name_hash_func(rr->soa.rname, state); + siphash24_compress(&rr->soa.serial, sizeof(rr->soa.serial), state); + siphash24_compress(&rr->soa.refresh, sizeof(rr->soa.refresh), state); + siphash24_compress(&rr->soa.retry, sizeof(rr->soa.retry), state); + siphash24_compress(&rr->soa.expire, sizeof(rr->soa.expire), state); + siphash24_compress(&rr->soa.minimum, sizeof(rr->soa.minimum), state); + break; + + case DNS_TYPE_MX: + siphash24_compress(&rr->mx.priority, sizeof(rr->mx.priority), state); + dns_name_hash_func(rr->mx.exchange, state); + break; + + case DNS_TYPE_LOC: + siphash24_compress(&rr->loc.version, sizeof(rr->loc.version), state); + siphash24_compress(&rr->loc.size, sizeof(rr->loc.size), state); + siphash24_compress(&rr->loc.horiz_pre, sizeof(rr->loc.horiz_pre), state); + siphash24_compress(&rr->loc.vert_pre, sizeof(rr->loc.vert_pre), state); + siphash24_compress(&rr->loc.latitude, sizeof(rr->loc.latitude), state); + siphash24_compress(&rr->loc.longitude, sizeof(rr->loc.longitude), state); + siphash24_compress(&rr->loc.altitude, sizeof(rr->loc.altitude), state); + break; + + case DNS_TYPE_SSHFP: + siphash24_compress(&rr->sshfp.algorithm, sizeof(rr->sshfp.algorithm), state); + siphash24_compress(&rr->sshfp.fptype, sizeof(rr->sshfp.fptype), state); + siphash24_compress(rr->sshfp.fingerprint, rr->sshfp.fingerprint_size, state); + break; + + case DNS_TYPE_DNSKEY: + siphash24_compress(&rr->dnskey.flags, sizeof(rr->dnskey.flags), state); + siphash24_compress(&rr->dnskey.protocol, sizeof(rr->dnskey.protocol), state); + siphash24_compress(&rr->dnskey.algorithm, sizeof(rr->dnskey.algorithm), state); + siphash24_compress(rr->dnskey.key, rr->dnskey.key_size, state); + break; + + case DNS_TYPE_RRSIG: + siphash24_compress(&rr->rrsig.type_covered, sizeof(rr->rrsig.type_covered), state); + siphash24_compress(&rr->rrsig.algorithm, sizeof(rr->rrsig.algorithm), state); + siphash24_compress(&rr->rrsig.labels, sizeof(rr->rrsig.labels), state); + siphash24_compress(&rr->rrsig.original_ttl, sizeof(rr->rrsig.original_ttl), state); + siphash24_compress(&rr->rrsig.expiration, sizeof(rr->rrsig.expiration), state); + siphash24_compress(&rr->rrsig.inception, sizeof(rr->rrsig.inception), state); + siphash24_compress(&rr->rrsig.key_tag, sizeof(rr->rrsig.key_tag), state); + dns_name_hash_func(rr->rrsig.signer, state); + siphash24_compress(rr->rrsig.signature, rr->rrsig.signature_size, state); + break; + + case DNS_TYPE_NSEC: + dns_name_hash_func(rr->nsec.next_domain_name, state); + /* FIXME: we leave out the type bitmap here. Hash + * would be better if we'd take it into account + * too. */ + break; + + case DNS_TYPE_DS: + siphash24_compress(&rr->ds.key_tag, sizeof(rr->ds.key_tag), state); + siphash24_compress(&rr->ds.algorithm, sizeof(rr->ds.algorithm), state); + siphash24_compress(&rr->ds.digest_type, sizeof(rr->ds.digest_type), state); + siphash24_compress(rr->ds.digest, rr->ds.digest_size, state); + break; + + case DNS_TYPE_NSEC3: + siphash24_compress(&rr->nsec3.algorithm, sizeof(rr->nsec3.algorithm), state); + siphash24_compress(&rr->nsec3.flags, sizeof(rr->nsec3.flags), state); + siphash24_compress(&rr->nsec3.iterations, sizeof(rr->nsec3.iterations), state); + siphash24_compress(rr->nsec3.salt, rr->nsec3.salt_size, state); + siphash24_compress(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, state); + /* FIXME: We leave the bitmaps out */ + break; + + case DNS_TYPE_TLSA: + siphash24_compress(&rr->tlsa.cert_usage, sizeof(rr->tlsa.cert_usage), state); + siphash24_compress(&rr->tlsa.selector, sizeof(rr->tlsa.selector), state); + siphash24_compress(&rr->tlsa.matching_type, sizeof(rr->tlsa.matching_type), state); + siphash24_compress(rr->tlsa.data, rr->tlsa.data_size, state); + break; + + case DNS_TYPE_CAA: + siphash24_compress(&rr->caa.flags, sizeof(rr->caa.flags), state); + string_hash_func(rr->caa.tag, state); + siphash24_compress(rr->caa.value, rr->caa.value_size, state); + break; + + case DNS_TYPE_OPENPGPKEY: + default: + siphash24_compress(rr->generic.data, rr->generic.data_size, state); + break; + } +} + +static int dns_resource_record_compare_func(const void *a, const void *b) { + const DnsResourceRecord *x = a, *y = b; + int ret; + + ret = dns_resource_key_compare_func(x->key, y->key); + if (ret != 0) + return ret; + + if (dns_resource_record_equal(x, y)) + return 0; + + /* This is a bit dirty, we don't implement proper ordering, but + * the hashtable doesn't need ordering anyway, hence we don't + * care. */ + return x < y ? -1 : 1; +} + +const struct hash_ops dns_resource_record_hash_ops = { + .hash = dns_resource_record_hash_func, + .compare = dns_resource_record_compare_func, +}; + +DnsResourceRecord *dns_resource_record_copy(DnsResourceRecord *rr) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *copy = NULL; + DnsResourceRecord *t; + + assert(rr); + + copy = dns_resource_record_new(rr->key); + if (!copy) + return NULL; + + copy->ttl = rr->ttl; + copy->expiry = rr->expiry; + copy->n_skip_labels_signer = rr->n_skip_labels_signer; + copy->n_skip_labels_source = rr->n_skip_labels_source; + copy->unparseable = rr->unparseable; + + switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { + + case DNS_TYPE_SRV: + copy->srv.priority = rr->srv.priority; + copy->srv.weight = rr->srv.weight; + copy->srv.port = rr->srv.port; + copy->srv.name = strdup(rr->srv.name); + if (!copy->srv.name) + return NULL; + break; + + case DNS_TYPE_PTR: + case DNS_TYPE_NS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: + copy->ptr.name = strdup(rr->ptr.name); + if (!copy->ptr.name) + return NULL; + break; + + case DNS_TYPE_HINFO: + copy->hinfo.cpu = strdup(rr->hinfo.cpu); + if (!copy->hinfo.cpu) + return NULL; + + copy->hinfo.os = strdup(rr->hinfo.os); + if(!copy->hinfo.os) + return NULL; + break; + + case DNS_TYPE_TXT: + case DNS_TYPE_SPF: + copy->txt.items = dns_txt_item_copy(rr->txt.items); + if (!copy->txt.items) + return NULL; + break; + + case DNS_TYPE_A: + copy->a = rr->a; + break; + + case DNS_TYPE_AAAA: + copy->aaaa = rr->aaaa; + break; + + case DNS_TYPE_SOA: + copy->soa.mname = strdup(rr->soa.mname); + if (!copy->soa.mname) + return NULL; + copy->soa.rname = strdup(rr->soa.rname); + if (!copy->soa.rname) + return NULL; + copy->soa.serial = rr->soa.serial; + copy->soa.refresh = rr->soa.refresh; + copy->soa.retry = rr->soa.retry; + copy->soa.expire = rr->soa.expire; + copy->soa.minimum = rr->soa.minimum; + break; + + case DNS_TYPE_MX: + copy->mx.priority = rr->mx.priority; + copy->mx.exchange = strdup(rr->mx.exchange); + if (!copy->mx.exchange) + return NULL; + break; + + case DNS_TYPE_LOC: + copy->loc = rr->loc; + break; + + case DNS_TYPE_SSHFP: + copy->sshfp.algorithm = rr->sshfp.algorithm; + copy->sshfp.fptype = rr->sshfp.fptype; + copy->sshfp.fingerprint = memdup(rr->sshfp.fingerprint, rr->sshfp.fingerprint_size); + if (!copy->sshfp.fingerprint) + return NULL; + copy->sshfp.fingerprint_size = rr->sshfp.fingerprint_size; + break; + + case DNS_TYPE_DNSKEY: + copy->dnskey.flags = rr->dnskey.flags; + copy->dnskey.protocol = rr->dnskey.protocol; + copy->dnskey.algorithm = rr->dnskey.algorithm; + copy->dnskey.key = memdup(rr->dnskey.key, rr->dnskey.key_size); + if (!copy->dnskey.key) + return NULL; + copy->dnskey.key_size = rr->dnskey.key_size; + break; + + case DNS_TYPE_RRSIG: + copy->rrsig.type_covered = rr->rrsig.type_covered; + copy->rrsig.algorithm = rr->rrsig.algorithm; + copy->rrsig.labels = rr->rrsig.labels; + copy->rrsig.original_ttl = rr->rrsig.original_ttl; + copy->rrsig.expiration = rr->rrsig.expiration; + copy->rrsig.inception = rr->rrsig.inception; + copy->rrsig.key_tag = rr->rrsig.key_tag; + copy->rrsig.signer = strdup(rr->rrsig.signer); + if (!copy->rrsig.signer) + return NULL; + copy->rrsig.signature = memdup(rr->rrsig.signature, rr->rrsig.signature_size); + if (!copy->rrsig.signature) + return NULL; + copy->rrsig.signature_size = rr->rrsig.signature_size; + break; + + case DNS_TYPE_NSEC: + copy->nsec.next_domain_name = strdup(rr->nsec.next_domain_name); + if (!copy->nsec.next_domain_name) + return NULL; + copy->nsec.types = bitmap_copy(rr->nsec.types); + if (!copy->nsec.types) + return NULL; + break; + + case DNS_TYPE_DS: + copy->ds.key_tag = rr->ds.key_tag; + copy->ds.algorithm = rr->ds.algorithm; + copy->ds.digest_type = rr->ds.digest_type; + copy->ds.digest = memdup(rr->ds.digest, rr->ds.digest_size); + if (!copy->ds.digest) + return NULL; + copy->ds.digest_size = rr->ds.digest_size; + break; + + case DNS_TYPE_NSEC3: + copy->nsec3.algorithm = rr->nsec3.algorithm; + copy->nsec3.flags = rr->nsec3.flags; + copy->nsec3.iterations = rr->nsec3.iterations; + copy->nsec3.salt = memdup(rr->nsec3.salt, rr->nsec3.salt_size); + if (!copy->nsec3.salt) + return NULL; + copy->nsec3.salt_size = rr->nsec3.salt_size; + copy->nsec3.next_hashed_name = memdup(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size); + if (!copy->nsec3.next_hashed_name_size) + return NULL; + copy->nsec3.next_hashed_name_size = rr->nsec3.next_hashed_name_size; + copy->nsec3.types = bitmap_copy(rr->nsec3.types); + if (!copy->nsec3.types) + return NULL; + break; + + case DNS_TYPE_TLSA: + copy->tlsa.cert_usage = rr->tlsa.cert_usage; + copy->tlsa.selector = rr->tlsa.selector; + copy->tlsa.matching_type = rr->tlsa.matching_type; + copy->tlsa.data = memdup(rr->tlsa.data, rr->tlsa.data_size); + if (!copy->tlsa.data) + return NULL; + copy->tlsa.data_size = rr->tlsa.data_size; + break; + + case DNS_TYPE_CAA: + copy->caa.flags = rr->caa.flags; + copy->caa.tag = strdup(rr->caa.tag); + if (!copy->caa.tag) + return NULL; + copy->caa.value = memdup(rr->caa.value, rr->caa.value_size); + if (!copy->caa.value) + return NULL; + copy->caa.value_size = rr->caa.value_size; + break; + + case DNS_TYPE_OPT: + default: + copy->generic.data = memdup(rr->generic.data, rr->generic.data_size); + if (!copy->generic.data) + return NULL; + copy->generic.data_size = rr->generic.data_size; + break; + } + + t = copy; + copy = NULL; + + return t; +} + +int dns_resource_record_clamp_ttl(DnsResourceRecord **rr, uint32_t max_ttl) { + DnsResourceRecord *old_rr, *new_rr; + uint32_t new_ttl; + + assert(rr); + old_rr = *rr; + + if (old_rr->key->type == DNS_TYPE_OPT) + return -EINVAL; + + new_ttl = MIN(old_rr->ttl, max_ttl); + if (new_ttl == old_rr->ttl) + return 0; + + if (old_rr->n_ref == 1) { + /* Patch in place */ + old_rr->ttl = new_ttl; + return 1; + } + + new_rr = dns_resource_record_copy(old_rr); + if (!new_rr) + return -ENOMEM; + + new_rr->ttl = new_ttl; + + dns_resource_record_unref(*rr); + *rr = new_rr; + + return 1; +} + +DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i) { + DnsTxtItem *n; + + if (!i) + return NULL; + + n = i->items_next; + + free(i); + return dns_txt_item_free_all(n); +} + +bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b) { + + if (a == b) + return true; + + if (!a != !b) + return false; + + if (!a) + return true; + + if (a->length != b->length) + return false; + + if (memcmp(a->data, b->data, a->length) != 0) + return false; + + return dns_txt_item_equal(a->items_next, b->items_next); +} + +DnsTxtItem *dns_txt_item_copy(DnsTxtItem *first) { + DnsTxtItem *i, *copy = NULL, *end = NULL; + + LIST_FOREACH(items, i, first) { + DnsTxtItem *j; + + j = memdup(i, offsetof(DnsTxtItem, data) + i->length + 1); + if (!j) { + dns_txt_item_free_all(copy); + return NULL; + } + + LIST_INSERT_AFTER(items, copy, end, j); + end = j; + } + + return copy; +} + +static const char* const dnssec_algorithm_table[_DNSSEC_ALGORITHM_MAX_DEFINED] = { + /* Mnemonics as listed on https://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ + [DNSSEC_ALGORITHM_RSAMD5] = "RSAMD5", + [DNSSEC_ALGORITHM_DH] = "DH", + [DNSSEC_ALGORITHM_DSA] = "DSA", + [DNSSEC_ALGORITHM_ECC] = "ECC", + [DNSSEC_ALGORITHM_RSASHA1] = "RSASHA1", + [DNSSEC_ALGORITHM_DSA_NSEC3_SHA1] = "DSA-NSEC3-SHA1", + [DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1] = "RSASHA1-NSEC3-SHA1", + [DNSSEC_ALGORITHM_RSASHA256] = "RSASHA256", + [DNSSEC_ALGORITHM_RSASHA512] = "RSASHA512", + [DNSSEC_ALGORITHM_ECC_GOST] = "ECC-GOST", + [DNSSEC_ALGORITHM_ECDSAP256SHA256] = "ECDSAP256SHA256", + [DNSSEC_ALGORITHM_ECDSAP384SHA384] = "ECDSAP384SHA384", + [DNSSEC_ALGORITHM_INDIRECT] = "INDIRECT", + [DNSSEC_ALGORITHM_PRIVATEDNS] = "PRIVATEDNS", + [DNSSEC_ALGORITHM_PRIVATEOID] = "PRIVATEOID", +}; +DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(dnssec_algorithm, int, 255); + +static const char* const dnssec_digest_table[_DNSSEC_DIGEST_MAX_DEFINED] = { + /* Names as listed on https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ + [DNSSEC_DIGEST_SHA1] = "SHA-1", + [DNSSEC_DIGEST_SHA256] = "SHA-256", + [DNSSEC_DIGEST_GOST_R_34_11_94] = "GOST_R_34.11-94", + [DNSSEC_DIGEST_SHA384] = "SHA-384", +}; +DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(dnssec_digest, int, 255); diff --git a/src/grp-resolve/libbasic-dns/test/GNUmakefile b/src/grp-resolve/libbasic-dns/test/GNUmakefile new file mode 120000 index 0000000000..13308a50cd --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/GNUmakefile @@ -0,0 +1 @@ +../../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/libbasic-dns/test/Makefile b/src/grp-resolve/libbasic-dns/test/Makefile new file mode 100644 index 0000000000..165f401d26 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/Makefile @@ -0,0 +1,97 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +tests += \ + test-dns-packet \ + test-resolve-tables \ + test-dnssec + +manual_tests += \ + test-dnssec-complex + +test_resolve_tables_SOURCES = \ + src/resolve/test-resolve-tables.c \ + src/resolve/dns_type-from-name.h \ + src/resolve/dns_type-to-name.h \ + $(basic_dns_sources) \ + src/shared/test-tables.h + +test_resolve_tables_CFLAGS = \ + $(GCRYPT_CFLAGS) + +test_resolve_tables_LDADD = \ + libsystemd-shared.la \ + $(GCRYPT_LIBS) \ + -lm + +test_dns_packet_SOURCES = \ + src/resolve/test-dns-packet.c \ + $(basic_dns_sources) + +test_dns_packet_CPPFLAGS = \ + -DRESOLVE_TEST_DIR=\"$(abs_top_srcdir)/src/resolve/test-data\" + +test_dns_packet_CFLAGS = \ + $(GCRYPT_CFLAGS) + +test_dns_packet_LDADD = \ + libsystemd-shared.la \ + $(GCRYPT_LIBS) \ + -lm + +EXTRA_DIST += \ + src/resolve/test-data/_openpgpkey.fedoraproject.org.pkts \ + src/resolve/test-data/fedoraproject.org.pkts \ + src/resolve/test-data/gandi.net.pkts \ + src/resolve/test-data/google.com.pkts \ + src/resolve/test-data/root.pkts \ + src/resolve/test-data/sw1a1aa-sw1a2aa-sw1a2ab-sw1a2ac.find.me.uk.pkts \ + src/resolve/test-data/teamits.com.pkts \ + src/resolve/test-data/zbyszek@fedoraproject.org.pkts \ + src/resolve/test-data/_443._tcp.fedoraproject.org.pkts \ + src/resolve/test-data/kyhwana.org.pkts \ + src/resolve/test-data/fake-caa.pkts + +test_dnssec_SOURCES = \ + src/resolve/test-dnssec.c \ + $(basic_dns_sources) + +test_dnssec_CFLAGS = \ + $(GCRYPT_CFLAGS) + +test_dnssec_LDADD = \ + libsystemd-shared.la \ + $(GCRYPT_LIBS) \ + -lm + +test_dnssec_complex_SOURCES = \ + src/resolve/test-dnssec-complex.c \ + src/resolve/dns-type.c \ + src/resolve/dns-type.h + +test_dnssec_complex_LDADD = \ + libsystemd-shared.la + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/libbasic-dns/test/test-data/_443._tcp.fedoraproject.org.pkts b/src/grp-resolve/libbasic-dns/test/test-data/_443._tcp.fedoraproject.org.pkts Binary files differnew file mode 100644 index 0000000000..a383c6286d --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/_443._tcp.fedoraproject.org.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/_openpgpkey.fedoraproject.org.pkts b/src/grp-resolve/libbasic-dns/test/test-data/_openpgpkey.fedoraproject.org.pkts Binary files differnew file mode 100644 index 0000000000..15de02e997 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/_openpgpkey.fedoraproject.org.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/fake-caa.pkts b/src/grp-resolve/libbasic-dns/test/test-data/fake-caa.pkts Binary files differnew file mode 100644 index 0000000000..1c3ecc5491 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/fake-caa.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/fedoraproject.org.pkts b/src/grp-resolve/libbasic-dns/test/test-data/fedoraproject.org.pkts Binary files differnew file mode 100644 index 0000000000..17874844d9 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/fedoraproject.org.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/gandi.net.pkts b/src/grp-resolve/libbasic-dns/test/test-data/gandi.net.pkts Binary files differnew file mode 100644 index 0000000000..5ef51e0c8e --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/gandi.net.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/google.com.pkts b/src/grp-resolve/libbasic-dns/test/test-data/google.com.pkts Binary files differnew file mode 100644 index 0000000000..f98c4cd855 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/google.com.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/kyhwana.org.pkts b/src/grp-resolve/libbasic-dns/test/test-data/kyhwana.org.pkts Binary files differnew file mode 100644 index 0000000000..e28a725c9a --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/kyhwana.org.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/root.pkts b/src/grp-resolve/libbasic-dns/test/test-data/root.pkts Binary files differnew file mode 100644 index 0000000000..54ba668c75 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/root.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/sw1a1aa-sw1a2aa-sw1a2ab-sw1a2ac.find.me.uk.pkts b/src/grp-resolve/libbasic-dns/test/test-data/sw1a1aa-sw1a2aa-sw1a2ab-sw1a2ac.find.me.uk.pkts Binary files differnew file mode 100644 index 0000000000..a854249532 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/sw1a1aa-sw1a2aa-sw1a2ab-sw1a2ac.find.me.uk.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/teamits.com.pkts b/src/grp-resolve/libbasic-dns/test/test-data/teamits.com.pkts Binary files differnew file mode 100644 index 0000000000..11deb39677 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/teamits.com.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-data/zbyszek@fedoraproject.org.pkts b/src/grp-resolve/libbasic-dns/test/test-data/zbyszek@fedoraproject.org.pkts Binary files differnew file mode 100644 index 0000000000..f0a6f982df --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-data/zbyszek@fedoraproject.org.pkts diff --git a/src/grp-resolve/libbasic-dns/test/test-dns-packet.c b/src/grp-resolve/libbasic-dns/test/test-dns-packet.c new file mode 100644 index 0000000000..7a012c13dd --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-dns-packet.c @@ -0,0 +1,132 @@ +/*** + This file is part of systemd + + Copyright 2016 Zbigniew Jędrzejewski-Szmek + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <glob.h> +#include <net/if.h> + +#include "basic-dns/resolved-dns-packet.h" +#include "basic-dns/resolved-dns-rr.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/glob-util.h" +#include "systemd-basic/log.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/unaligned.h" + +#define HASH_KEY SD_ID128_MAKE(d3,1e,48,90,4b,fa,4c,fe,af,9d,d5,a1,d7,2e,8a,b1) + +static void verify_rr_copy(DnsResourceRecord *rr) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *copy = NULL; + const char *a, *b; + + assert_se(copy = dns_resource_record_copy(rr)); + assert_se(dns_resource_record_equal(copy, rr) > 0); + + assert_se(a = dns_resource_record_to_string(rr)); + assert_se(b = dns_resource_record_to_string(copy)); + + assert_se(streq(a, b)); +} + +static uint64_t hash(DnsResourceRecord *rr) { + struct siphash state; + + siphash24_init(&state, HASH_KEY.bytes); + dns_resource_record_hash_func(rr, &state); + return siphash24_finalize(&state); +} + +static void test_packet_from_file(const char* filename, bool canonical) { + _cleanup_free_ char *data = NULL; + size_t data_size, packet_size, offset; + + assert_se(read_full_file(filename, &data, &data_size) >= 0); + assert_se(data); + assert_se(data_size > 8); + + log_info("============== %s %s==============", filename, canonical ? "canonical " : ""); + + for (offset = 0; offset < data_size; offset += 8 + packet_size) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL, *p2 = NULL; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL, *rr2 = NULL; + const char *s, *s2; + uint64_t hash1, hash2; + + packet_size = unaligned_read_le64(data + offset); + assert_se(packet_size > 0); + assert_se(offset + 8 + packet_size <= data_size); + + assert_se(dns_packet_new(&p, DNS_PROTOCOL_DNS, 0) >= 0); + + assert_se(dns_packet_append_blob(p, data + offset + 8, packet_size, NULL) >= 0); + assert_se(dns_packet_read_rr(p, &rr, NULL, NULL) >= 0); + + verify_rr_copy(rr); + + s = dns_resource_record_to_string(rr); + assert_se(s); + puts(s); + + hash1 = hash(rr); + + assert_se(dns_resource_record_to_wire_format(rr, canonical) >= 0); + + assert_se(dns_packet_new(&p2, DNS_PROTOCOL_DNS, 0) >= 0); + assert_se(dns_packet_append_blob(p2, rr->wire_format, rr->wire_format_size, NULL) >= 0); + assert_se(dns_packet_read_rr(p2, &rr2, NULL, NULL) >= 0); + + verify_rr_copy(rr); + + s2 = dns_resource_record_to_string(rr); + assert_se(s2); + assert_se(streq(s, s2)); + + hash2 = hash(rr); + assert_se(hash1 == hash2); + } +} + +int main(int argc, char **argv) { + int i, N; + _cleanup_globfree_ glob_t g = {}; + char **fnames; + + log_parse_environment(); + + if (argc >= 2) { + N = argc - 1; + fnames = argv + 1; + } else { + assert_se(glob(RESOLVE_TEST_DIR "/*.pkts", GLOB_NOSORT, NULL, &g) == 0); + N = g.gl_pathc; + fnames = g.gl_pathv; + } + + for (i = 0; i < N; i++) { + test_packet_from_file(fnames[i], false); + puts(""); + test_packet_from_file(fnames[i], true); + if (i + 1 < N) + puts(""); + } + + return EXIT_SUCCESS; +} diff --git a/src/grp-resolve/libbasic-dns/test/test-dnssec-complex.c b/src/grp-resolve/libbasic-dns/test/test-dnssec-complex.c new file mode 100644 index 0000000000..2eb4cfe1c2 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-dnssec-complex.c @@ -0,0 +1,236 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <netinet/ip.h> + +#include <systemd/sd-bus.h> + +#include "basic-dns/dns-type.h" +#include "sd-bus/bus-common-errors.h" +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/time-util.h" + +#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC) + +static void prefix_random(const char *name, char **ret) { + uint64_t i, u; + char *m = NULL; + + u = 1 + (random_u64() & 3); + + for (i = 0; i < u; i++) { + _cleanup_free_ char *b = NULL; + char *x; + + assert_se(asprintf(&b, "x%" PRIu64 "x", random_u64())); + x = strjoin(b, ".", name, NULL); + assert_se(x); + + free(m); + m = x; + } + + *ret = m; + } + +static void test_rr_lookup(sd_bus *bus, const char *name, uint16_t type, const char *result) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *m = NULL; + int r; + + /* If the name starts with a dot, we prefix one to three random labels */ + if (startswith(name, ".")) { + prefix_random(name + 1, &m); + name = m; + } + + assert_se(sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveRecord") >= 0); + + assert_se(sd_bus_message_append(req, "isqqt", 0, name, DNS_CLASS_IN, type, UINT64_C(0)) >= 0); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + + if (r < 0) { + assert_se(result); + assert_se(sd_bus_error_has_name(&error, result)); + log_info("[OK] %s/%s resulted in <%s>.", name, dns_type_to_string(type), error.name); + } else { + assert_se(!result); + log_info("[OK] %s/%s succeeded.", name, dns_type_to_string(type)); + } +} + +static void test_hostname_lookup(sd_bus *bus, const char *name, int family, const char *result) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *m = NULL; + const char *af; + int r; + + af = family == AF_UNSPEC ? "AF_UNSPEC" : af_to_name(family); + + /* If the name starts with a dot, we prefix one to three random labels */ + if (startswith(name, ".")) { + prefix_random(name + 1, &m); + name = m; + } + + assert_se(sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveHostname") >= 0); + + assert_se(sd_bus_message_append(req, "isit", 0, name, family, UINT64_C(0)) >= 0); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + + if (r < 0) { + assert_se(result); + assert_se(sd_bus_error_has_name(&error, result)); + log_info("[OK] %s/%s resulted in <%s>.", name, af, error.name); + } else { + assert_se(!result); + log_info("[OK] %s/%s succeeded.", name, af); + } + +} + +int main(int argc, char* argv[]) { + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + + /* Note that this is a manual test as it requires: + * + * Full network access + * A DNSSEC capable DNS server + * That zones contacted are still set up as they were when I wrote this. + */ + + assert_se(sd_bus_open_system(&bus) >= 0); + + /* Normally signed */ + test_rr_lookup(bus, "www.eurid.eu", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, "www.eurid.eu", AF_UNSPEC, NULL); + + test_rr_lookup(bus, "sigok.verteiltesysteme.net", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, "sigok.verteiltesysteme.net", AF_UNSPEC, NULL); + + /* Normally signed, NODATA */ + test_rr_lookup(bus, "www.eurid.eu", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + test_rr_lookup(bus, "sigok.verteiltesysteme.net", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* Invalid signature */ + test_rr_lookup(bus, "sigfail.verteiltesysteme.net", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, "sigfail.verteiltesysteme.net", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* Invalid signature, RSA, wildcard */ + test_rr_lookup(bus, ".wilda.rhybar.0skar.cz", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, ".wilda.rhybar.0skar.cz", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* Invalid signature, ECDSA, wildcard */ + test_rr_lookup(bus, ".wilda.rhybar.ecdsa.0skar.cz", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, ".wilda.rhybar.ecdsa.0skar.cz", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* NXDOMAIN in NSEC domain */ + test_rr_lookup(bus, "hhh.nasa.gov", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "hhh.nasa.gov", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + + /* wildcard, NSEC zone */ + test_rr_lookup(bus, ".wilda.nsec.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wilda.nsec.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC zone, NODATA */ + test_rr_lookup(bus, ".wilda.nsec.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC3 zone */ + test_rr_lookup(bus, ".wilda.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wilda.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC3 zone, NODATA */ + test_rr_lookup(bus, ".wilda.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC zone, CNAME */ + test_rr_lookup(bus, ".wild.nsec.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wild.nsec.0skar.cz", AF_UNSPEC, NULL); + test_hostname_lookup(bus, ".wild.nsec.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC zone, NODATA, CNAME */ + test_rr_lookup(bus, ".wild.nsec.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC3 zone, CNAME */ + test_rr_lookup(bus, ".wild.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wild.0skar.cz", AF_UNSPEC, NULL); + test_hostname_lookup(bus, ".wild.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC3 zone, NODATA, CNAME */ + test_rr_lookup(bus, ".wild.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* NODATA due to empty non-terminal in NSEC domain */ + test_rr_lookup(bus, "herndon.nasa.gov", DNS_TYPE_A, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_UNSPEC, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_INET, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_INET6, BUS_ERROR_NO_SUCH_RR); + + /* NXDOMAIN in NSEC root zone: */ + test_rr_lookup(bus, "jasdhjas.kjkfgjhfjg", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + + /* NXDOMAIN in NSEC3 .com zone: */ + test_rr_lookup(bus, "kjkfgjhfjgsdfdsfd.com", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + + /* Unsigned A */ + test_rr_lookup(bus, "poettering.de", DNS_TYPE_A, NULL); + test_rr_lookup(bus, "poettering.de", DNS_TYPE_AAAA, NULL); + test_hostname_lookup(bus, "poettering.de", AF_UNSPEC, NULL); + test_hostname_lookup(bus, "poettering.de", AF_INET, NULL); + test_hostname_lookup(bus, "poettering.de", AF_INET6, NULL); + +#ifdef HAVE_LIBIDN + /* Unsigned A with IDNA conversion necessary */ + test_hostname_lookup(bus, "pöttering.de", AF_UNSPEC, NULL); + test_hostname_lookup(bus, "pöttering.de", AF_INET, NULL); + test_hostname_lookup(bus, "pöttering.de", AF_INET6, NULL); +#endif + + /* DNAME, pointing to NXDOMAIN */ + test_rr_lookup(bus, ".ireallyhpoethisdoesnexist.xn--kprw13d.", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_rr_lookup(bus, ".ireallyhpoethisdoesnexist.xn--kprw13d.", DNS_TYPE_RP, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + + return 0; +} diff --git a/src/grp-resolve/libbasic-dns/test/test-dnssec.c b/src/grp-resolve/libbasic-dns/test/test-dnssec.c new file mode 100644 index 0000000000..c2b8a74944 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-dnssec.c @@ -0,0 +1,343 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <arpa/inet.h> +#include <netinet/in.h> +#include <sys/socket.h> + +#include "basic-dns/resolved-dns-dnssec.h" +#include "basic-dns/resolved-dns-rr.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/hexdecoct.h" +#include "systemd-basic/string-util.h" + +static void test_dnssec_canonicalize_one(const char *original, const char *canonical, int r) { + char canonicalized[DNSSEC_CANONICAL_HOSTNAME_MAX]; + + assert_se(dnssec_canonicalize(original, canonicalized, sizeof(canonicalized)) == r); + if (r < 0) + return; + + assert_se(streq(canonicalized, canonical)); +} + +static void test_dnssec_canonicalize(void) { + test_dnssec_canonicalize_one("", ".", 1); + test_dnssec_canonicalize_one(".", ".", 1); + test_dnssec_canonicalize_one("foo", "foo.", 4); + test_dnssec_canonicalize_one("foo.", "foo.", 4); + test_dnssec_canonicalize_one("FOO.", "foo.", 4); + test_dnssec_canonicalize_one("FOO.bar.", "foo.bar.", 8); + test_dnssec_canonicalize_one("FOO..bar.", NULL, -EINVAL); +} + +#ifdef HAVE_GCRYPT + +static void test_dnssec_verify_dns_key(void) { + + static const uint8_t ds1_fprint[] = { + 0x46, 0x8B, 0xC8, 0xDD, 0xC7, 0xE8, 0x27, 0x03, 0x40, 0xBB, 0x8A, 0x1F, 0x3B, 0x2E, 0x45, 0x9D, + 0x80, 0x67, 0x14, 0x01, + }; + static const uint8_t ds2_fprint[] = { + 0x8A, 0xEE, 0x80, 0x47, 0x05, 0x5F, 0x83, 0xD1, 0x48, 0xBA, 0x8F, 0xF6, 0xDD, 0xA7, 0x60, 0xCE, + 0x94, 0xF7, 0xC7, 0x5E, 0x52, 0x4C, 0xF2, 0xE9, 0x50, 0xB9, 0x2E, 0xCB, 0xEF, 0x96, 0xB9, 0x98, + }; + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0xa8, 0x12, 0xda, 0x4f, 0xd2, 0x7d, 0x54, 0x14, 0x0e, 0xcc, 0x5b, 0x5e, + 0x45, 0x9c, 0x96, 0x98, 0xc0, 0xc0, 0x85, 0x81, 0xb1, 0x47, 0x8c, 0x7d, 0xe8, 0x39, 0x50, 0xcc, + 0xc5, 0xd0, 0xf2, 0x00, 0x81, 0x67, 0x79, 0xf6, 0xcc, 0x9d, 0xad, 0x6c, 0xbb, 0x7b, 0x6f, 0x48, + 0x97, 0x15, 0x1c, 0xfd, 0x0b, 0xfe, 0xd3, 0xd7, 0x7d, 0x9f, 0x81, 0x26, 0xd3, 0xc5, 0x65, 0x49, + 0xcf, 0x46, 0x62, 0xb0, 0x55, 0x6e, 0x47, 0xc7, 0x30, 0xef, 0x51, 0xfb, 0x3e, 0xc6, 0xef, 0xde, + 0x27, 0x3f, 0xfa, 0x57, 0x2d, 0xa7, 0x1d, 0x80, 0x46, 0x9a, 0x5f, 0x14, 0xb3, 0xb0, 0x2c, 0xbe, + 0x72, 0xca, 0xdf, 0xb2, 0xff, 0x36, 0x5b, 0x4f, 0xec, 0x58, 0x8e, 0x8d, 0x01, 0xe9, 0xa9, 0xdf, + 0xb5, 0x60, 0xad, 0x52, 0x4d, 0xfc, 0xa9, 0x3e, 0x8d, 0x35, 0x95, 0xb3, 0x4e, 0x0f, 0xca, 0x45, + 0x1b, 0xf7, 0xef, 0x3a, 0x88, 0x25, 0x08, 0xc7, 0x4e, 0x06, 0xc1, 0x62, 0x1a, 0xce, 0xd8, 0x77, + 0xbd, 0x02, 0x65, 0xf8, 0x49, 0xfb, 0xce, 0xf6, 0xa8, 0x09, 0xfc, 0xde, 0xb2, 0x09, 0x9d, 0x39, + 0xf8, 0x63, 0x9c, 0x32, 0x42, 0x7c, 0xa0, 0x30, 0x86, 0x72, 0x7a, 0x4a, 0xc6, 0xd4, 0xb3, 0x2d, + 0x24, 0xef, 0x96, 0x3f, 0xc2, 0xda, 0xd3, 0xf2, 0x15, 0x6f, 0xda, 0x65, 0x4b, 0x81, 0x28, 0x68, + 0xf4, 0xfe, 0x3e, 0x71, 0x4f, 0x50, 0x96, 0x72, 0x58, 0xa1, 0x89, 0xdd, 0x01, 0x61, 0x39, 0x39, + 0xc6, 0x76, 0xa4, 0xda, 0x02, 0x70, 0x3d, 0xc0, 0xdc, 0x8d, 0x70, 0x72, 0x04, 0x90, 0x79, 0xd4, + 0xec, 0x65, 0xcf, 0x49, 0x35, 0x25, 0x3a, 0x14, 0x1a, 0x45, 0x20, 0xeb, 0x31, 0xaf, 0x92, 0xba, + 0x20, 0xd3, 0xcd, 0xa7, 0x13, 0x44, 0xdc, 0xcf, 0xf0, 0x27, 0x34, 0xb9, 0xe7, 0x24, 0x6f, 0x73, + 0xe7, 0xea, 0x77, 0x03, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *dnskey = NULL, *ds1 = NULL, *ds2 = NULL; + + /* The two DS RRs in effect for nasa.gov on 2015-12-01. */ + ds1 = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, "nasa.gov"); + assert_se(ds1); + + ds1->ds.key_tag = 47857; + ds1->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + ds1->ds.digest_type = DNSSEC_DIGEST_SHA1; + ds1->ds.digest_size = sizeof(ds1_fprint); + ds1->ds.digest = memdup(ds1_fprint, ds1->ds.digest_size); + assert_se(ds1->ds.digest); + + log_info("DS1: %s", strna(dns_resource_record_to_string(ds1))); + + ds2 = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, "NASA.GOV"); + assert_se(ds2); + + ds2->ds.key_tag = 47857; + ds2->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + ds2->ds.digest_type = DNSSEC_DIGEST_SHA256; + ds2->ds.digest_size = sizeof(ds2_fprint); + ds2->ds.digest = memdup(ds2_fprint, ds2->ds.digest_size); + assert_se(ds2->ds.digest); + + log_info("DS2: %s", strna(dns_resource_record_to_string(ds2))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nasa.GOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 257; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_verify_dnskey_by_ds(dnskey, ds1, false) > 0); + assert_se(dnssec_verify_dnskey_by_ds(dnskey, ds2, false) > 0); +} + +static void test_dnssec_verify_rrset(void) { + + static const uint8_t signature_blob[] = { + 0x7f, 0x79, 0xdd, 0x5e, 0x89, 0x79, 0x18, 0xd0, 0x34, 0x86, 0x8c, 0x72, 0x77, 0x75, 0x48, 0x4d, + 0xc3, 0x7d, 0x38, 0x04, 0xab, 0xcd, 0x9e, 0x4c, 0x82, 0xb0, 0x92, 0xca, 0xe9, 0x66, 0xe9, 0x6e, + 0x47, 0xc7, 0x68, 0x8c, 0x94, 0xf6, 0x69, 0xcb, 0x75, 0x94, 0xe6, 0x30, 0xa6, 0xfb, 0x68, 0x64, + 0x96, 0x1a, 0x84, 0xe1, 0xdc, 0x16, 0x4c, 0x83, 0x6c, 0x44, 0xf2, 0x74, 0x4d, 0x74, 0x79, 0x8f, + 0xf3, 0xf4, 0x63, 0x0d, 0xef, 0x5a, 0xe7, 0xe2, 0xfd, 0xf2, 0x2b, 0x38, 0x7c, 0x28, 0x96, 0x9d, + 0xb6, 0xcd, 0x5c, 0x3b, 0x57, 0xe2, 0x24, 0x78, 0x65, 0xd0, 0x9e, 0x77, 0x83, 0x09, 0x6c, 0xff, + 0x3d, 0x52, 0x3f, 0x6e, 0xd1, 0xed, 0x2e, 0xf9, 0xee, 0x8e, 0xa6, 0xbe, 0x9a, 0xa8, 0x87, 0x76, + 0xd8, 0x77, 0xcc, 0x96, 0xa0, 0x98, 0xa1, 0xd1, 0x68, 0x09, 0x43, 0xcf, 0x56, 0xd9, 0xd1, 0x66, + }; + + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0x9b, 0x49, 0x9b, 0xc1, 0xf9, 0x9a, 0xe0, 0x4e, 0xcf, 0xcb, 0x14, 0x45, + 0x2e, 0xc9, 0xf9, 0x74, 0xa7, 0x18, 0xb5, 0xf3, 0xde, 0x39, 0x49, 0xdf, 0x63, 0x33, 0x97, 0x52, + 0xe0, 0x8e, 0xac, 0x50, 0x30, 0x8e, 0x09, 0xd5, 0x24, 0x3d, 0x26, 0xa4, 0x49, 0x37, 0x2b, 0xb0, + 0x6b, 0x1b, 0xdf, 0xde, 0x85, 0x83, 0xcb, 0x22, 0x4e, 0x60, 0x0a, 0x91, 0x1a, 0x1f, 0xc5, 0x40, + 0xb1, 0xc3, 0x15, 0xc1, 0x54, 0x77, 0x86, 0x65, 0x53, 0xec, 0x10, 0x90, 0x0c, 0x91, 0x00, 0x5e, + 0x15, 0xdc, 0x08, 0x02, 0x4c, 0x8c, 0x0d, 0xc0, 0xac, 0x6e, 0xc4, 0x3e, 0x1b, 0x80, 0x19, 0xe4, + 0xf7, 0x5f, 0x77, 0x51, 0x06, 0x87, 0x61, 0xde, 0xa2, 0x18, 0x0f, 0x40, 0x8b, 0x79, 0x72, 0xfa, + 0x8d, 0x1a, 0x44, 0x47, 0x0d, 0x8e, 0x3a, 0x2d, 0xc7, 0x39, 0xbf, 0x56, 0x28, 0x97, 0xd9, 0x20, + 0x4f, 0x00, 0x51, 0x3b, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *a = NULL, *rrsig = NULL, *dnskey = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnssecResult result; + + a = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, "nAsA.gov"); + assert_se(a); + + a->a.in_addr.s_addr = inet_addr("52.0.14.116"); + + log_info("A: %s", strna(dns_resource_record_to_string(a))); + + rrsig = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_RRSIG, "NaSa.GOV."); + assert_se(rrsig); + + rrsig->rrsig.type_covered = DNS_TYPE_A; + rrsig->rrsig.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rrsig->rrsig.labels = 2; + rrsig->rrsig.original_ttl = 600; + rrsig->rrsig.expiration = 0x5683135c; + rrsig->rrsig.inception = 0x565b7da8; + rrsig->rrsig.key_tag = 63876; + rrsig->rrsig.signer = strdup("Nasa.Gov."); + assert_se(rrsig->rrsig.signer); + rrsig->rrsig.signature_size = sizeof(signature_blob); + rrsig->rrsig.signature = memdup(signature_blob, rrsig->rrsig.signature_size); + assert_se(rrsig->rrsig.signature); + + log_info("RRSIG: %s", strna(dns_resource_record_to_string(rrsig))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nASA.gOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 256; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_key_match_rrsig(a->key, rrsig) > 0); + assert_se(dnssec_rrsig_match_dnskey(rrsig, dnskey, false) > 0); + + answer = dns_answer_new(1); + assert_se(answer); + assert_se(dns_answer_add(answer, a, 0, DNS_ANSWER_AUTHENTICATED) >= 0); + + /* Validate the RR as it if was 2015-12-2 today */ + assert_se(dnssec_verify_rrset(answer, a->key, rrsig, dnskey, 1449092754*USEC_PER_SEC, &result) >= 0); + assert_se(result == DNSSEC_VALIDATED); +} + +static void test_dnssec_verify_rrset2(void) { + + static const uint8_t signature_blob[] = { + 0x48, 0x45, 0xc8, 0x8b, 0xc0, 0x14, 0x92, 0xf5, 0x15, 0xc6, 0x84, 0x9d, 0x2f, 0xe3, 0x32, 0x11, + 0x7d, 0xf1, 0xe6, 0x87, 0xb9, 0x42, 0xd3, 0x8b, 0x9e, 0xaf, 0x92, 0x31, 0x0a, 0x53, 0xad, 0x8b, + 0xa7, 0x5c, 0x83, 0x39, 0x8c, 0x28, 0xac, 0xce, 0x6e, 0x9c, 0x18, 0xe3, 0x31, 0x16, 0x6e, 0xca, + 0x38, 0x31, 0xaf, 0xd9, 0x94, 0xf1, 0x84, 0xb1, 0xdf, 0x5a, 0xc2, 0x73, 0x22, 0xf6, 0xcb, 0xa2, + 0xe7, 0x8c, 0x77, 0x0c, 0x74, 0x2f, 0xc2, 0x13, 0xb0, 0x93, 0x51, 0xa9, 0x4f, 0xae, 0x0a, 0xda, + 0x45, 0xcc, 0xfd, 0x43, 0x99, 0x36, 0x9a, 0x0d, 0x21, 0xe0, 0xeb, 0x30, 0x65, 0xd4, 0xa0, 0x27, + 0x37, 0x3b, 0xe4, 0xc1, 0xc5, 0xa1, 0x2a, 0xd1, 0x76, 0xc4, 0x7e, 0x64, 0x0e, 0x5a, 0xa6, 0x50, + 0x24, 0xd5, 0x2c, 0xcc, 0x6d, 0xe5, 0x37, 0xea, 0xbd, 0x09, 0x34, 0xed, 0x24, 0x06, 0xa1, 0x22, + }; + + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0xc3, 0x7f, 0x1d, 0xd1, 0x1c, 0x97, 0xb1, 0x13, 0x34, 0x3a, 0x9a, 0xea, + 0xee, 0xd9, 0x5a, 0x11, 0x1b, 0x17, 0xc7, 0xe3, 0xd4, 0xda, 0x20, 0xbc, 0x5d, 0xba, 0x74, 0xe3, + 0x37, 0x99, 0xec, 0x25, 0xce, 0x93, 0x7f, 0xbd, 0x22, 0x73, 0x7e, 0x14, 0x71, 0xe0, 0x60, 0x07, + 0xd4, 0x39, 0x8b, 0x5e, 0xe9, 0xba, 0x25, 0xe8, 0x49, 0xe9, 0x34, 0xef, 0xfe, 0x04, 0x5c, 0xa5, + 0x27, 0xcd, 0xa9, 0xda, 0x70, 0x05, 0x21, 0xab, 0x15, 0x82, 0x24, 0xc3, 0x94, 0xf5, 0xd7, 0xb7, + 0xc4, 0x66, 0xcb, 0x32, 0x6e, 0x60, 0x2b, 0x55, 0x59, 0x28, 0x89, 0x8a, 0x72, 0xde, 0x88, 0x56, + 0x27, 0x95, 0xd9, 0xac, 0x88, 0x4f, 0x65, 0x2b, 0x68, 0xfc, 0xe6, 0x41, 0xc1, 0x1b, 0xef, 0x4e, + 0xd6, 0xc2, 0x0f, 0x64, 0x88, 0x95, 0x5e, 0xdd, 0x3a, 0x02, 0x07, 0x50, 0xa9, 0xda, 0xa4, 0x49, + 0x74, 0x62, 0xfe, 0xd7, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *nsec = NULL, *rrsig = NULL, *dnskey = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnssecResult result; + + nsec = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_NSEC, "nasa.gov"); + assert_se(nsec); + + nsec->nsec.next_domain_name = strdup("3D-Printing.nasa.gov"); + assert_se(nsec->nsec.next_domain_name); + + nsec->nsec.types = bitmap_new(); + assert_se(nsec->nsec.types); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_A) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_NS) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_SOA) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_MX) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_TXT) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_RRSIG) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_NSEC) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_DNSKEY) >= 0); + assert_se(bitmap_set(nsec->nsec.types, 65534) >= 0); + + log_info("NSEC: %s", strna(dns_resource_record_to_string(nsec))); + + rrsig = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_RRSIG, "NaSa.GOV."); + assert_se(rrsig); + + rrsig->rrsig.type_covered = DNS_TYPE_NSEC; + rrsig->rrsig.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rrsig->rrsig.labels = 2; + rrsig->rrsig.original_ttl = 300; + rrsig->rrsig.expiration = 0x5689002f; + rrsig->rrsig.inception = 0x56617230; + rrsig->rrsig.key_tag = 30390; + rrsig->rrsig.signer = strdup("Nasa.Gov."); + assert_se(rrsig->rrsig.signer); + rrsig->rrsig.signature_size = sizeof(signature_blob); + rrsig->rrsig.signature = memdup(signature_blob, rrsig->rrsig.signature_size); + assert_se(rrsig->rrsig.signature); + + log_info("RRSIG: %s", strna(dns_resource_record_to_string(rrsig))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nASA.gOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 256; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_key_match_rrsig(nsec->key, rrsig) > 0); + assert_se(dnssec_rrsig_match_dnskey(rrsig, dnskey, false) > 0); + + answer = dns_answer_new(1); + assert_se(answer); + assert_se(dns_answer_add(answer, nsec, 0, DNS_ANSWER_AUTHENTICATED) >= 0); + + /* Validate the RR as it if was 2015-12-11 today */ + assert_se(dnssec_verify_rrset(answer, nsec->key, rrsig, dnskey, 1449849318*USEC_PER_SEC, &result) >= 0); + assert_se(result == DNSSEC_VALIDATED); +} + +static void test_dnssec_nsec3_hash(void) { + static const uint8_t salt[] = { 0xB0, 0x1D, 0xFA, 0xCE }; + static const uint8_t next_hashed_name[] = { 0x84, 0x10, 0x26, 0x53, 0xc9, 0xfa, 0x4d, 0x85, 0x6c, 0x97, 0x82, 0xe2, 0x8f, 0xdf, 0x2d, 0x5e, 0x87, 0x69, 0xc4, 0x52 }; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + uint8_t h[DNSSEC_HASH_SIZE_MAX]; + _cleanup_free_ char *b = NULL; + int k; + + /* The NSEC3 RR for eurid.eu on 2015-12-14. */ + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_NSEC3, "PJ8S08RR45VIQDAQGE7EN3VHKNROTBMM.eurid.eu."); + assert_se(rr); + + rr->nsec3.algorithm = DNSSEC_DIGEST_SHA1; + rr->nsec3.flags = 1; + rr->nsec3.iterations = 1; + rr->nsec3.salt = memdup(salt, sizeof(salt)); + assert_se(rr->nsec3.salt); + rr->nsec3.salt_size = sizeof(salt); + rr->nsec3.next_hashed_name = memdup(next_hashed_name, sizeof(next_hashed_name)); + assert_se(rr->nsec3.next_hashed_name); + rr->nsec3.next_hashed_name_size = sizeof(next_hashed_name); + + log_info("NSEC3: %s", strna(dns_resource_record_to_string(rr))); + + k = dnssec_nsec3_hash(rr, "eurid.eu", &h); + assert_se(k >= 0); + + b = base32hexmem(h, k, false); + assert_se(b); + assert_se(strcasecmp(b, "PJ8S08RR45VIQDAQGE7EN3VHKNROTBMM") == 0); +} + +#endif + +int main(int argc, char*argv[]) { + + test_dnssec_canonicalize(); + +#ifdef HAVE_GCRYPT + test_dnssec_verify_dns_key(); + test_dnssec_verify_rrset(); + test_dnssec_verify_rrset2(); + test_dnssec_nsec3_hash(); +#endif + + return 0; +} diff --git a/src/grp-resolve/libbasic-dns/test/test-resolve-tables.c b/src/grp-resolve/libbasic-dns/test/test-resolve-tables.c new file mode 100644 index 0000000000..98474b1abf --- /dev/null +++ b/src/grp-resolve/libbasic-dns/test/test-resolve-tables.c @@ -0,0 +1,64 @@ +/*** + This file is part of systemd + + Copyright 2013 Zbigniew Jędrzejewski-Szmek + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/dns-type.h" +#include "systemd-shared/test-tables.h" + +int main(int argc, char **argv) { + uint16_t i; + + test_table_sparse(dns_type, DNS_TYPE); + + log_info("/* DNS_TYPE */"); + for (i = 0; i < _DNS_TYPE_MAX; i++) { + const char *s; + + s = dns_type_to_string(i); + assert_se(s == NULL || strlen(s) < _DNS_TYPE_STRING_MAX); + + if (s) + log_info("%-*s %s%s%s%s%s%s%s%s%s", + (int) _DNS_TYPE_STRING_MAX - 1, s, + dns_type_is_pseudo(i) ? "pseudo " : "", + dns_type_is_valid_query(i) ? "valid_query " : "", + dns_type_is_valid_rr(i) ? "is_valid_rr " : "", + dns_type_may_redirect(i) ? "may_redirect " : "", + dns_type_is_dnssec(i) ? "dnssec " : "", + dns_type_is_obsolete(i) ? "obsolete " : "", + dns_type_may_wildcard(i) ? "wildcard " : "", + dns_type_apex_only(i) ? "apex_only " : "", + dns_type_needs_authentication(i) ? "needs_authentication" : ""); + } + + log_info("/* DNS_CLASS */"); + for (i = 0; i < _DNS_CLASS_MAX; i++) { + const char *s; + + s = dns_class_to_string(i); + assert_se(s == NULL || strlen(s) < _DNS_CLASS_STRING_MAX); + + if (s) + log_info("%-*s %s%s", + (int) _DNS_CLASS_STRING_MAX - 1, s, + dns_class_is_pseudo(i) ? "is_pseudo " : "", + dns_class_is_valid_rr(i) ? "is_valid_rr " : ""); + } + + return EXIT_SUCCESS; +} diff --git a/src/grp-resolve/nss-resolve/GNUmakefile b/src/grp-resolve/nss-resolve/GNUmakefile new file mode 120000 index 0000000000..95e5924740 --- /dev/null +++ b/src/grp-resolve/nss-resolve/GNUmakefile @@ -0,0 +1 @@ +../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/nss-resolve/Makefile b/src/grp-resolve/nss-resolve/Makefile new file mode 100644 index 0000000000..310f816b06 --- /dev/null +++ b/src/grp-resolve/nss-resolve/Makefile @@ -0,0 +1,46 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +libnss_resolve_la_SOURCES = \ + src/nss-resolve/nss-resolve.sym \ + src/nss-resolve/nss-resolve.c + +libnss_resolve_la_LDFLAGS = \ + -module \ + -export-dynamic \ + -avoid-version \ + -shared \ + -shrext .so.2 \ + -Wl,--version-script=$(srcdir)/nss-resolve.sym + +libnss_resolve_la_LIBADD = \ + libsystemd-internal.la \ + libsystemd-basic.la \ + -ldl + +rootlib_LTLIBRARIES += \ + libnss_resolve.la + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/nss-resolve/nss-resolve.c b/src/grp-resolve/nss-resolve/nss-resolve.c new file mode 100644 index 0000000000..681416e18f --- /dev/null +++ b/src/grp-resolve/nss-resolve/nss-resolve.c @@ -0,0 +1,681 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <dlfcn.h> +#include <errno.h> +#include <netdb.h> +#include <nss.h> +#include <stdlib.h> +#include <string.h> + +#include <systemd/sd-bus.h> + +#include "sd-bus/bus-common-errors.h" +#include "systemd-basic/in-addr-util.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/nss-util.h" +#include "systemd-basic/signal-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/util.h" + +NSS_GETHOSTBYNAME_PROTOTYPES(resolve); +NSS_GETHOSTBYADDR_PROTOTYPES(resolve); + +#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC) + +typedef void (*voidfunc_t)(void); + +static voidfunc_t find_fallback(const char *module, const char *symbol) { + void *dl; + + /* Try to find a fallback NSS module symbol */ + + dl = dlopen(module, RTLD_LAZY|RTLD_NODELETE); + if (!dl) + return NULL; + + return dlsym(dl, symbol); +} + +static bool bus_error_shall_fallback(sd_bus_error *e) { + return sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN) || + sd_bus_error_has_name(e, SD_BUS_ERROR_NAME_HAS_NO_OWNER) || + sd_bus_error_has_name(e, SD_BUS_ERROR_NO_REPLY) || + sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED); +} + +static int count_addresses(sd_bus_message *m, int af, const char **canonical) { + int c = 0, r; + + assert(m); + assert(canonical); + + r = sd_bus_message_enter_container(m, 'a', "(iiay)"); + if (r < 0) + return r; + + while ((r = sd_bus_message_enter_container(m, 'r', "iiay")) > 0) { + int family, ifindex; + + assert_cc(sizeof(int32_t) == sizeof(int)); + + r = sd_bus_message_read(m, "ii", &ifindex, &family); + if (r < 0) + return r; + + r = sd_bus_message_skip(m, "ay"); + if (r < 0) + return r; + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + if (af != AF_UNSPEC && family != af) + continue; + + c++; + } + if (r < 0) + return r; + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + r = sd_bus_message_read(m, "s", canonical); + if (r < 0) + return r; + + r = sd_bus_message_rewind(m, true); + if (r < 0) + return r; + + return c; +} + +enum nss_status _nss_resolve_gethostbyname4_r( + const char *name, + struct gaih_addrtuple **pat, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL; + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + enum nss_status ret = NSS_STATUS_UNAVAIL; + const char *canonical = NULL; + size_t l, ms, idx; + char *r_name; + int c, r, i = 0; + + BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); + + assert(name); + assert(pat); + assert(buffer); + assert(errnop); + assert(h_errnop); + + r = sd_bus_open_system(&bus); + if (r < 0) + goto fallback; + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveHostname"); + if (r < 0) + goto fail; + + r = sd_bus_message_set_auto_start(req, false); + if (r < 0) + goto fail; + + r = sd_bus_message_append(req, "isit", 0, name, AF_UNSPEC, (uint64_t) 0); + if (r < 0) + goto fail; + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) { + if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + if (bus_error_shall_fallback(&error)) + goto fallback; + + /* Treat all other error conditions as NOTFOUND, and fail. This includes DNSSEC errors and + suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf configuration can distuingish + such executed but negative replies from complete failure to talk to resolved. */ + ret = NSS_STATUS_NOTFOUND; + goto fail; + } + + c = count_addresses(reply, AF_UNSPEC, &canonical); + if (c < 0) { + r = c; + goto fail; + } + if (c == 0) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + if (isempty(canonical)) + canonical = name; + + l = strlen(canonical); + ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c; + if (buflen < ms) { + *errnop = ENOMEM; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; + } + + /* First, append name */ + r_name = buffer; + memcpy(r_name, canonical, l+1); + idx = ALIGN(l+1); + + /* Second, append addresses */ + r_tuple_first = (struct gaih_addrtuple*) (buffer + idx); + + r = sd_bus_message_enter_container(reply, 'a', "(iiay)"); + if (r < 0) + goto fail; + + while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) { + int family, ifindex; + const void *a; + size_t sz; + + assert_cc(sizeof(int32_t) == sizeof(int)); + + r = sd_bus_message_read(reply, "ii", &ifindex, &family); + if (r < 0) + goto fail; + + if (ifindex < 0) { + r = -EINVAL; + goto fail; + } + + r = sd_bus_message_read_array(reply, 'y', &a, &sz); + if (r < 0) + goto fail; + + r = sd_bus_message_exit_container(reply); + if (r < 0) + goto fail; + + if (!IN_SET(family, AF_INET, AF_INET6)) + continue; + + if (sz != FAMILY_ADDRESS_SIZE(family)) { + r = -EINVAL; + goto fail; + } + + r_tuple = (struct gaih_addrtuple*) (buffer + idx); + r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple))); + r_tuple->name = r_name; + r_tuple->family = family; + r_tuple->scopeid = ifindex; + memcpy(r_tuple->addr, a, sz); + + idx += ALIGN(sizeof(struct gaih_addrtuple)); + i++; + } + if (r < 0) + goto fail; + + assert(i == c); + assert(idx == ms); + + if (*pat) + **pat = *r_tuple_first; + else + *pat = r_tuple_first; + + if (ttlp) + *ttlp = 0; + + /* Explicitly reset all error variables */ + *errnop = 0; + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + return NSS_STATUS_SUCCESS; + +fallback: + { + _nss_gethostbyname4_r_t fallback; + + fallback = (_nss_gethostbyname4_r_t) + find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname4_r"); + + if (fallback) + return fallback(name, pat, buffer, buflen, errnop, h_errnop, ttlp); + } + +fail: + *errnop = -r; + *h_errnop = NO_RECOVERY; + return ret; +} + +enum nss_status _nss_resolve_gethostbyname3_r( + const char *name, + int af, + struct hostent *result, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp, + char **canonp) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *r_name, *r_aliases, *r_addr, *r_addr_list; + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + enum nss_status ret = NSS_STATUS_UNAVAIL; + size_t l, idx, ms, alen; + const char *canonical; + int c, r, i = 0; + + BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); + + assert(name); + assert(result); + assert(buffer); + assert(errnop); + assert(h_errnop); + + if (af == AF_UNSPEC) + af = AF_INET; + + if (af != AF_INET && af != AF_INET6) { + r = -EAFNOSUPPORT; + goto fail; + } + + r = sd_bus_open_system(&bus); + if (r < 0) + goto fallback; + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveHostname"); + if (r < 0) + goto fail; + + r = sd_bus_message_set_auto_start(req, false); + if (r < 0) + goto fail; + + r = sd_bus_message_append(req, "isit", 0, name, af, (uint64_t) 0); + if (r < 0) + goto fail; + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) { + if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + if (bus_error_shall_fallback(&error)) + goto fallback; + + ret = NSS_STATUS_NOTFOUND; + goto fail; + } + + c = count_addresses(reply, af, &canonical); + if (c < 0) { + r = c; + goto fail; + } + if (c == 0) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + if (isempty(canonical)) + canonical = name; + + alen = FAMILY_ADDRESS_SIZE(af); + l = strlen(canonical); + + ms = ALIGN(l+1) + c * ALIGN(alen) + (c+2) * sizeof(char*); + + if (buflen < ms) { + *errnop = ENOMEM; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; + } + + /* First, append name */ + r_name = buffer; + memcpy(r_name, canonical, l+1); + idx = ALIGN(l+1); + + /* Second, create empty aliases array */ + r_aliases = buffer + idx; + ((char**) r_aliases)[0] = NULL; + idx += sizeof(char*); + + /* Third, append addresses */ + r_addr = buffer + idx; + + r = sd_bus_message_enter_container(reply, 'a', "(iiay)"); + if (r < 0) + goto fail; + + while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) { + int ifindex, family; + const void *a; + size_t sz; + + r = sd_bus_message_read(reply, "ii", &ifindex, &family); + if (r < 0) + goto fail; + + if (ifindex < 0) { + r = -EINVAL; + goto fail; + } + + r = sd_bus_message_read_array(reply, 'y', &a, &sz); + if (r < 0) + goto fail; + + r = sd_bus_message_exit_container(reply); + if (r < 0) + goto fail; + + if (family != af) + continue; + + if (sz != alen) { + r = -EINVAL; + goto fail; + } + + memcpy(r_addr + i*ALIGN(alen), a, alen); + i++; + } + if (r < 0) + goto fail; + + assert(i == c); + idx += c * ALIGN(alen); + + /* Fourth, append address pointer array */ + r_addr_list = buffer + idx; + for (i = 0; i < c; i++) + ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen); + + ((char**) r_addr_list)[i] = NULL; + idx += (c+1) * sizeof(char*); + + assert(idx == ms); + + result->h_name = r_name; + result->h_aliases = (char**) r_aliases; + result->h_addrtype = af; + result->h_length = alen; + result->h_addr_list = (char**) r_addr_list; + + /* Explicitly reset all error variables */ + *errnop = 0; + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + if (ttlp) + *ttlp = 0; + + if (canonp) + *canonp = r_name; + + return NSS_STATUS_SUCCESS; + +fallback: + { + _nss_gethostbyname3_r_t fallback; + + fallback = (_nss_gethostbyname3_r_t) + find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyname3_r"); + if (fallback) + return fallback(name, af, result, buffer, buflen, errnop, h_errnop, ttlp, canonp); + } + +fail: + *errnop = -r; + *h_errnop = NO_RECOVERY; + return ret; +} + +enum nss_status _nss_resolve_gethostbyaddr2_r( + const void* addr, socklen_t len, + int af, + struct hostent *result, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *r_name, *r_aliases, *r_addr, *r_addr_list; + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + enum nss_status ret = NSS_STATUS_UNAVAIL; + unsigned c = 0, i = 0; + size_t ms = 0, idx; + const char *n; + int r, ifindex; + + BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); + + assert(addr); + assert(result); + assert(buffer); + assert(errnop); + assert(h_errnop); + + if (!IN_SET(af, AF_INET, AF_INET6)) { + *errnop = EAFNOSUPPORT; + *h_errnop = NO_DATA; + return NSS_STATUS_UNAVAIL; + } + + if (len != FAMILY_ADDRESS_SIZE(af)) { + *errnop = EINVAL; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + } + + r = sd_bus_open_system(&bus); + if (r < 0) + goto fallback; + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveAddress"); + if (r < 0) + goto fail; + + r = sd_bus_message_set_auto_start(req, false); + if (r < 0) + goto fail; + + r = sd_bus_message_append(req, "ii", 0, af); + if (r < 0) + goto fail; + + r = sd_bus_message_append_array(req, 'y', addr, len); + if (r < 0) + goto fail; + + r = sd_bus_message_append(req, "t", (uint64_t) 0); + if (r < 0) + goto fail; + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) { + if (sd_bus_error_has_name(&error, _BUS_ERROR_DNS "NXDOMAIN")) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + if (bus_error_shall_fallback(&error)) + goto fallback; + + ret = NSS_STATUS_NOTFOUND; + goto fail; + } + + r = sd_bus_message_enter_container(reply, 'a', "(is)"); + if (r < 0) + goto fail; + + while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) { + + if (ifindex < 0) { + r = -EINVAL; + goto fail; + } + + c++; + ms += ALIGN(strlen(n) + 1); + } + if (r < 0) + goto fail; + + r = sd_bus_message_rewind(reply, false); + if (r < 0) + return r; + + if (c <= 0) { + *errnop = ESRCH; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + ms += ALIGN(len) + /* the address */ + 2 * sizeof(char*) + /* pointers to the address, plus trailing NULL */ + c * sizeof(char*); /* pointers to aliases, plus trailing NULL */ + + if (buflen < ms) { + *errnop = ENOMEM; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; + } + + /* First, place address */ + r_addr = buffer; + memcpy(r_addr, addr, len); + idx = ALIGN(len); + + /* Second, place address list */ + r_addr_list = buffer + idx; + ((char**) r_addr_list)[0] = r_addr; + ((char**) r_addr_list)[1] = NULL; + idx += sizeof(char*) * 2; + + /* Third, reserve space for the aliases array */ + r_aliases = buffer + idx; + idx += sizeof(char*) * c; + + /* Fourth, place aliases */ + i = 0; + r_name = buffer + idx; + while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) { + char *p; + size_t l; + + l = strlen(n); + p = buffer + idx; + memcpy(p, n, l+1); + + if (i > 0) + ((char**) r_aliases)[i-1] = p; + i++; + + idx += ALIGN(l+1); + } + if (r < 0) + goto fail; + + ((char**) r_aliases)[c-1] = NULL; + assert(idx == ms); + + result->h_name = r_name; + result->h_aliases = (char**) r_aliases; + result->h_addrtype = af; + result->h_length = len; + result->h_addr_list = (char**) r_addr_list; + + if (ttlp) + *ttlp = 0; + + /* Explicitly reset all error variables */ + *errnop = 0; + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + return NSS_STATUS_SUCCESS; + +fallback: + { + _nss_gethostbyaddr2_r_t fallback; + + fallback = (_nss_gethostbyaddr2_r_t) + find_fallback("libnss_dns.so.2", "_nss_dns_gethostbyaddr2_r"); + + if (fallback) + return fallback(addr, len, af, result, buffer, buflen, errnop, h_errnop, ttlp); + } + +fail: + *errnop = -r; + *h_errnop = NO_RECOVERY; + return ret; +} + +NSS_GETHOSTBYNAME_FALLBACKS(resolve); +NSS_GETHOSTBYADDR_FALLBACKS(resolve); diff --git a/src/grp-resolve/nss-resolve/nss-resolve.sym b/src/grp-resolve/nss-resolve/nss-resolve.sym new file mode 100644 index 0000000000..df8dff2a20 --- /dev/null +++ b/src/grp-resolve/nss-resolve/nss-resolve.sym @@ -0,0 +1,19 @@ +/*** + This file is part of systemd. + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. +***/ + +{ +global: + _nss_resolve_gethostbyname_r; + _nss_resolve_gethostbyname2_r; + _nss_resolve_gethostbyname3_r; + _nss_resolve_gethostbyname4_r; + _nss_resolve_gethostbyaddr_r; + _nss_resolve_gethostbyaddr2_r; +local: *; +}; diff --git a/src/grp-resolve/nss-resolve/nss-resolve.xml b/src/grp-resolve/nss-resolve/nss-resolve.xml new file mode 100644 index 0000000000..9f24f65019 --- /dev/null +++ b/src/grp-resolve/nss-resolve/nss-resolve.xml @@ -0,0 +1,114 @@ +<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2011 Lennart Poettering + Copyright 2013 Tom Gundersen + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="nss-resolve" conditional='ENABLE_RESOLVED'> + + <refentryinfo> + <title>nss-resolve</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>nss-resolve</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>nss-resolve</refname> + <refname>libnss_resolve.so.2</refname> + <refpurpose>Provide hostname resolution via <filename>systemd-resolved.service</filename></refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>libnss_resolve.so.2</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>nss-resolve</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the + GNU C Library (<command>glibc</command>) enabling it to resolve host names via the + <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry> local network + name resolution service. It replaces the <command>nss-dns</command> plug-in module that traditionally resolves + hostnames via DNS.</para> + + <para>To activate the NSS module, add <literal>resolve</literal> to the line starting with + <literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para> + + <para>It is recommended to place <literal>resolve</literal> early in <filename>/etc/nsswitch.conf</filename>' + <literal>hosts:</literal> line (but after the <literal>files</literal> or <literal>mymachines</literal> entries), + replacing the <literal>dns</literal> entry if it exists, to ensure DNS queries are always routed via + <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + + <para>Note that <command>nss-resolve</command> will chain-load <command>nss-dns</command> if + <filename>systemd-resolved.service</filename> is not running, ensuring that basic DNS resolution continues to work + if the service is down.</para> + </refsect1> + + <refsect1> + <title>Example</title> + + <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables <command>nss-resolve</command> + correctly:</para> + +<programlisting>passwd: compat mymachines systemd +group: compat mymachines systemd +shadow: compat + +hosts: files mymachines <command>resolve [!UNAVAIL=return]</command> dns myhostname +networks: files + +protocols: db files +services: db files +ethers: db files +rpc: db files + +netgroup: nis</programlisting> + + <para>This keeps the <command>dns</command> module as a fallback for cases where the <command>nss-resolve</command> + module is not installed.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>nss-systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/grp-resolve/systemd-resolve/GNUmakefile b/src/grp-resolve/systemd-resolve/GNUmakefile new file mode 120000 index 0000000000..95e5924740 --- /dev/null +++ b/src/grp-resolve/systemd-resolve/GNUmakefile @@ -0,0 +1 @@ +../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/systemd-resolve/Makefile b/src/grp-resolve/systemd-resolve/Makefile new file mode 100644 index 0000000000..9d9b46d58d --- /dev/null +++ b/src/grp-resolve/systemd-resolve/Makefile @@ -0,0 +1,53 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +systemd_resolve_SOURCES = \ + src/resolve/resolve-tool.c \ + $(basic_dns_sources) \ + src/shared/gcrypt-util.c \ + src/shared/gcrypt-util.h + +nodist_systemd_resolve_SOURCES = \ + src/resolve/dns_type-from-name.h \ + src/resolve/dns_type-to-name.h + +systemd_resolve_CFLAGS = \ + $(GCRYPT_CFLAGS) + +systemd_resolve_LDADD = \ + libsystemd-shared.la \ + $(GCRYPT_LIBS) \ + -lm + +bin_PROGRAMS += \ + systemd-resolve + +dist_bashcompletion_data += \ + shell-completion/bash/systemd-resolve + +dist_zshcompletion_data += \ + shell-completion/zsh/_systemd-resolve + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/systemd-resolve/resolve-tool.c b/src/grp-resolve/systemd-resolve/resolve-tool.c new file mode 100644 index 0000000000..3e19b8563c --- /dev/null +++ b/src/grp-resolve/systemd-resolve/resolve-tool.c @@ -0,0 +1,2025 @@ +/*** + This file is part of systemd. + + Copyright 2014 Zbigniew Jędrzejewski-Szmek + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <getopt.h> +#include <net/if.h> + +#include <systemd/sd-bus.h> + +#include "basic-dns/resolved-def.h" +#include "basic-dns/resolved-dns-packet.h" +#include "sd-bus/bus-error.h" +#include "sd-bus/bus-util.h" +#include "sd-netlink/netlink-util.h" +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/escape.h" +#include "systemd-basic/in-addr-util.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/terminal-util.h" +#include "systemd-gcrypt/gcrypt-util.h" +#include "systemd-shared/pager.h" +#include "systemd-staging/sd-netlink.h" + +#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC) + +static int arg_family = AF_UNSPEC; +static int arg_ifindex = 0; +static uint16_t arg_type = 0; +static uint16_t arg_class = 0; +static bool arg_legend = true; +static uint64_t arg_flags = 0; +static bool arg_no_pager = false; + +typedef enum ServiceFamily { + SERVICE_FAMILY_TCP, + SERVICE_FAMILY_UDP, + SERVICE_FAMILY_SCTP, + _SERVICE_FAMILY_INVALID = -1, +} ServiceFamily; +static ServiceFamily arg_service_family = SERVICE_FAMILY_TCP; + +typedef enum RawType { + RAW_NONE, + RAW_PAYLOAD, + RAW_PACKET, +} RawType; +static RawType arg_raw = RAW_NONE; + +static enum { + MODE_RESOLVE_HOST, + MODE_RESOLVE_RECORD, + MODE_RESOLVE_SERVICE, + MODE_RESOLVE_OPENPGP, + MODE_RESOLVE_TLSA, + MODE_STATISTICS, + MODE_RESET_STATISTICS, + MODE_FLUSH_CACHES, + MODE_STATUS, +} arg_mode = MODE_RESOLVE_HOST; + +static ServiceFamily service_family_from_string(const char *s) { + if (s == NULL || streq(s, "tcp")) + return SERVICE_FAMILY_TCP; + if (streq(s, "udp")) + return SERVICE_FAMILY_UDP; + if (streq(s, "sctp")) + return SERVICE_FAMILY_SCTP; + return _SERVICE_FAMILY_INVALID; +} + +static const char* service_family_to_string(ServiceFamily service) { + switch(service) { + case SERVICE_FAMILY_TCP: + return "_tcp"; + case SERVICE_FAMILY_UDP: + return "_udp"; + case SERVICE_FAMILY_SCTP: + return "_sctp"; + default: + assert_not_reached("invalid service"); + } +} + +static void print_source(uint64_t flags, usec_t rtt) { + char rtt_str[FORMAT_TIMESTAMP_MAX]; + + if (!arg_legend) + return; + + if (flags == 0) + return; + + fputs("\n-- Information acquired via", stdout); + + if (flags != 0) + printf(" protocol%s%s%s%s%s", + flags & SD_RESOLVED_DNS ? " DNS" :"", + flags & SD_RESOLVED_LLMNR_IPV4 ? " LLMNR/IPv4" : "", + flags & SD_RESOLVED_LLMNR_IPV6 ? " LLMNR/IPv6" : "", + flags & SD_RESOLVED_MDNS_IPV4 ? "mDNS/IPv4" : "", + flags & SD_RESOLVED_MDNS_IPV6 ? "mDNS/IPv6" : ""); + + assert_se(format_timespan(rtt_str, sizeof(rtt_str), rtt, 100)); + + printf(" in %s", rtt_str); + + fputc('.', stdout); + fputc('\n', stdout); + + printf("-- Data is authenticated: %s\n", yes_no(flags & SD_RESOLVED_AUTHENTICATED)); +} + +static int resolve_host(sd_bus *bus, const char *name) { + + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + const char *canonical = NULL; + char ifname[IF_NAMESIZE] = ""; + unsigned c = 0; + int r; + uint64_t flags; + usec_t ts; + + assert(name); + + if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname)) + return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex); + + log_debug("Resolving %s (family %s, interface %s).", name, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname); + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveHostname"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(req, "isit", arg_ifindex, name, arg_family, arg_flags); + if (r < 0) + return bus_log_create_error(r); + + ts = now(CLOCK_MONOTONIC); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) + return log_error_errno(r, "%s: resolve call failed: %s", name, bus_error_message(&error, r)); + + ts = now(CLOCK_MONOTONIC) - ts; + + r = sd_bus_message_enter_container(reply, 'a', "(iiay)"); + if (r < 0) + return bus_log_parse_error(r); + + while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) { + _cleanup_free_ char *pretty = NULL; + int ifindex, family; + const void *a; + size_t sz; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(reply, "ii", &ifindex, &family); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read_array(reply, 'y', &a, &sz); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + if (!IN_SET(family, AF_INET, AF_INET6)) { + log_debug("%s: skipping entry with family %d (%s)", name, family, af_to_name(family) ?: "unknown"); + continue; + } + + if (sz != FAMILY_ADDRESS_SIZE(family)) { + log_error("%s: systemd-resolved returned address of invalid size %zu for family %s", name, sz, af_to_name(family) ?: "unknown"); + return -EINVAL; + } + + ifname[0] = 0; + if (ifindex > 0 && !if_indextoname(ifindex, ifname)) + log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex); + + r = in_addr_ifindex_to_string(family, a, ifindex, &pretty); + if (r < 0) + return log_error_errno(r, "Failed to print address for %s: %m", name); + + printf("%*s%s %s%s%s\n", + (int) strlen(name), c == 0 ? name : "", c == 0 ? ":" : " ", + pretty, + isempty(ifname) ? "" : "%", ifname); + + c++; + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read(reply, "st", &canonical, &flags); + if (r < 0) + return bus_log_parse_error(r); + + if (!streq(name, canonical)) + printf("%*s%s (%s)\n", + (int) strlen(name), c == 0 ? name : "", c == 0 ? ":" : " ", + canonical); + + if (c == 0) { + log_error("%s: no addresses found", name); + return -ESRCH; + } + + print_source(flags, ts); + + return 0; +} + +static int resolve_address(sd_bus *bus, int family, const union in_addr_union *address, int ifindex) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *pretty = NULL; + char ifname[IF_NAMESIZE] = ""; + uint64_t flags; + unsigned c = 0; + usec_t ts; + int r; + + assert(bus); + assert(IN_SET(family, AF_INET, AF_INET6)); + assert(address); + + if (ifindex <= 0) + ifindex = arg_ifindex; + + r = in_addr_ifindex_to_string(family, address, ifindex, &pretty); + if (r < 0) + return log_oom(); + + if (ifindex > 0 && !if_indextoname(ifindex, ifname)) + return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex); + + log_debug("Resolving %s%s%s.", pretty, isempty(ifname) ? "" : "%", ifname); + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveAddress"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(req, "ii", ifindex, family); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append_array(req, 'y', address, FAMILY_ADDRESS_SIZE(family)); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(req, "t", arg_flags); + if (r < 0) + return bus_log_create_error(r); + + ts = now(CLOCK_MONOTONIC); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) { + log_error("%s: resolve call failed: %s", pretty, bus_error_message(&error, r)); + return r; + } + + ts = now(CLOCK_MONOTONIC) - ts; + + r = sd_bus_message_enter_container(reply, 'a', "(is)"); + if (r < 0) + return bus_log_create_error(r); + + while ((r = sd_bus_message_enter_container(reply, 'r', "is")) > 0) { + const char *n; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(reply, "is", &ifindex, &n); + if (r < 0) + return r; + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return r; + + ifname[0] = 0; + if (ifindex > 0 && !if_indextoname(ifindex, ifname)) + log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex); + + printf("%*s%*s%*s%s %s\n", + (int) strlen(pretty), c == 0 ? pretty : "", + isempty(ifname) ? 0 : 1, c > 0 || isempty(ifname) ? "" : "%", + (int) strlen(ifname), c == 0 ? ifname : "", + c == 0 ? ":" : " ", + n); + + c++; + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read(reply, "t", &flags); + if (r < 0) + return bus_log_parse_error(r); + + if (c == 0) { + log_error("%s: no names found", pretty); + return -ESRCH; + } + + print_source(flags, ts); + + return 0; +} + +static int output_rr_packet(const void *d, size_t l, int ifindex) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + int r; + char ifname[IF_NAMESIZE] = ""; + + r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0); + if (r < 0) + return log_oom(); + + p->refuse_compression = true; + + r = dns_packet_append_blob(p, d, l, NULL); + if (r < 0) + return log_oom(); + + r = dns_packet_read_rr(p, &rr, NULL, NULL); + if (r < 0) + return log_error_errno(r, "Failed to parse RR: %m"); + + if (arg_raw == RAW_PAYLOAD) { + void *data; + ssize_t k; + + k = dns_resource_record_payload(rr, &data); + if (k < 0) + return log_error_errno(k, "Cannot dump RR: %m"); + fwrite(data, 1, k, stdout); + } else { + const char *s; + + s = dns_resource_record_to_string(rr); + if (!s) + return log_oom(); + + if (ifindex > 0 && !if_indextoname(ifindex, ifname)) + log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex); + + printf("%s%s%s\n", s, isempty(ifname) ? "" : " # interface ", ifname); + } + + return 0; +} + +static int resolve_record(sd_bus *bus, const char *name, uint16_t class, uint16_t type, bool warn_missing) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char ifname[IF_NAMESIZE] = ""; + unsigned n = 0; + uint64_t flags; + int r; + usec_t ts; + bool needs_authentication = false; + + assert(name); + + if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname)) + return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex); + + log_debug("Resolving %s %s %s (interface %s).", name, dns_class_to_string(class), dns_type_to_string(type), isempty(ifname) ? "*" : ifname); + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveRecord"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(req, "isqqt", arg_ifindex, name, class, type, arg_flags); + if (r < 0) + return bus_log_create_error(r); + + ts = now(CLOCK_MONOTONIC); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) { + if (warn_missing || r != -ENXIO) + log_error("%s: resolve call failed: %s", name, bus_error_message(&error, r)); + return r; + } + + ts = now(CLOCK_MONOTONIC) - ts; + + r = sd_bus_message_enter_container(reply, 'a', "(iqqay)"); + if (r < 0) + return bus_log_parse_error(r); + + while ((r = sd_bus_message_enter_container(reply, 'r', "iqqay")) > 0) { + uint16_t c, t; + int ifindex; + const void *d; + size_t l; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(reply, "iqq", &ifindex, &c, &t); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read_array(reply, 'y', &d, &l); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + if (arg_raw == RAW_PACKET) { + uint64_t u64 = htole64(l); + + fwrite(&u64, sizeof(u64), 1, stdout); + fwrite(d, 1, l, stdout); + } else { + r = output_rr_packet(d, l, ifindex); + if (r < 0) + return r; + } + + if (dns_type_needs_authentication(t)) + needs_authentication = true; + + n++; + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read(reply, "t", &flags); + if (r < 0) + return bus_log_parse_error(r); + + if (n == 0) { + if (warn_missing) + log_error("%s: no records found", name); + return -ESRCH; + } + + print_source(flags, ts); + + if ((flags & SD_RESOLVED_AUTHENTICATED) == 0 && needs_authentication) { + fflush(stdout); + + fprintf(stderr, "\n%s" + "WARNING: The resources shown contain cryptographic key data which could not be\n" + " authenticated. It is not suitable to authenticate any communication.\n" + " This is usually indication that DNSSEC authentication was not enabled\n" + " or is not available for the selected protocol or DNS servers.%s\n", + ansi_highlight_red(), + ansi_normal()); + } + + return 0; +} + +static int resolve_rfc4501(sd_bus *bus, const char *name) { + uint16_t type = 0, class = 0; + const char *p, *q, *n; + int r; + + assert(bus); + assert(name); + assert(startswith(name, "dns:")); + + /* Parse RFC 4501 dns: URIs */ + + p = name + 4; + + if (p[0] == '/') { + const char *e; + + if (p[1] != '/') + goto invalid; + + e = strchr(p + 2, '/'); + if (!e) + goto invalid; + + if (e != p + 2) + log_warning("DNS authority specification not supported; ignoring specified authority."); + + p = e + 1; + } + + q = strchr(p, '?'); + if (q) { + n = strndupa(p, q - p); + q++; + + for (;;) { + const char *f; + + f = startswith_no_case(q, "class="); + if (f) { + _cleanup_free_ char *t = NULL; + const char *e; + + if (class != 0) { + log_error("DNS class specified twice."); + return -EINVAL; + } + + e = strchrnul(f, ';'); + t = strndup(f, e - f); + if (!t) + return log_oom(); + + r = dns_class_from_string(t); + if (r < 0) { + log_error("Unknown DNS class %s.", t); + return -EINVAL; + } + + class = r; + + if (*e == ';') { + q = e + 1; + continue; + } + + break; + } + + f = startswith_no_case(q, "type="); + if (f) { + _cleanup_free_ char *t = NULL; + const char *e; + + if (type != 0) { + log_error("DNS type specified twice."); + return -EINVAL; + } + + e = strchrnul(f, ';'); + t = strndup(f, e - f); + if (!t) + return log_oom(); + + r = dns_type_from_string(t); + if (r < 0) { + log_error("Unknown DNS type %s.", t); + return -EINVAL; + } + + type = r; + + if (*e == ';') { + q = e + 1; + continue; + } + + break; + } + + goto invalid; + } + } else + n = p; + + if (class == 0) + class = arg_class ?: DNS_CLASS_IN; + if (type == 0) + type = arg_type ?: DNS_TYPE_A; + + return resolve_record(bus, n, class, type, true); + +invalid: + log_error("Invalid DNS URI: %s", name); + return -EINVAL; +} + +static int resolve_service(sd_bus *bus, const char *name, const char *type, const char *domain) { + const char *canonical_name, *canonical_type, *canonical_domain; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char ifname[IF_NAMESIZE] = ""; + size_t indent, sz; + uint64_t flags; + const char *p; + unsigned c; + usec_t ts; + int r; + + assert(bus); + assert(domain); + + name = empty_to_null(name); + type = empty_to_null(type); + + if (arg_ifindex > 0 && !if_indextoname(arg_ifindex, ifname)) + return log_error_errno(errno, "Failed to resolve interface name for index %i: %m", arg_ifindex); + + if (name) + log_debug("Resolving service \"%s\" of type %s in %s (family %s, interface %s).", name, type, domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname); + else if (type) + log_debug("Resolving service type %s of %s (family %s, interface %s).", type, domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname); + else + log_debug("Resolving service type %s (family %s, interface %s).", domain, af_to_name(arg_family) ?: "*", isempty(ifname) ? "*" : ifname); + + r = sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveService"); + if (r < 0) + return bus_log_create_error(r); + + r = sd_bus_message_append(req, "isssit", arg_ifindex, name, type, domain, arg_family, arg_flags); + if (r < 0) + return bus_log_create_error(r); + + ts = now(CLOCK_MONOTONIC); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + if (r < 0) + return log_error_errno(r, "Resolve call failed: %s", bus_error_message(&error, r)); + + ts = now(CLOCK_MONOTONIC) - ts; + + r = sd_bus_message_enter_container(reply, 'a', "(qqqsa(iiay)s)"); + if (r < 0) + return bus_log_parse_error(r); + + indent = + (name ? strlen(name) + 1 : 0) + + (type ? strlen(type) + 1 : 0) + + strlen(domain) + 2; + + c = 0; + while ((r = sd_bus_message_enter_container(reply, 'r', "qqqsa(iiay)s")) > 0) { + uint16_t priority, weight, port; + const char *hostname, *canonical; + + r = sd_bus_message_read(reply, "qqqs", &priority, &weight, &port, &hostname); + if (r < 0) + return bus_log_parse_error(r); + + if (name) + printf("%*s%s", (int) strlen(name), c == 0 ? name : "", c == 0 ? "/" : " "); + if (type) + printf("%*s%s", (int) strlen(type), c == 0 ? type : "", c == 0 ? "/" : " "); + + printf("%*s%s %s:%u [priority=%u, weight=%u]\n", + (int) strlen(domain), c == 0 ? domain : "", + c == 0 ? ":" : " ", + hostname, port, + priority, weight); + + r = sd_bus_message_enter_container(reply, 'a', "(iiay)"); + if (r < 0) + return bus_log_parse_error(r); + + while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) { + _cleanup_free_ char *pretty = NULL; + int ifindex, family; + const void *a; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(reply, "ii", &ifindex, &family); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read_array(reply, 'y', &a, &sz); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + if (!IN_SET(family, AF_INET, AF_INET6)) { + log_debug("%s: skipping entry with family %d (%s)", name, family, af_to_name(family) ?: "unknown"); + continue; + } + + if (sz != FAMILY_ADDRESS_SIZE(family)) { + log_error("%s: systemd-resolved returned address of invalid size %zu for family %s", name, sz, af_to_name(family) ?: "unknown"); + return -EINVAL; + } + + ifname[0] = 0; + if (ifindex > 0 && !if_indextoname(ifindex, ifname)) + log_warning_errno(errno, "Failed to resolve interface name for index %i: %m", ifindex); + + r = in_addr_to_string(family, a, &pretty); + if (r < 0) + return log_error_errno(r, "Failed to print address for %s: %m", name); + + printf("%*s%s%s%s\n", (int) indent, "", pretty, isempty(ifname) ? "" : "%s", ifname); + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read(reply, "s", &canonical); + if (r < 0) + return bus_log_parse_error(r); + + if (!streq(hostname, canonical)) + printf("%*s(%s)\n", (int) indent, "", canonical); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + c++; + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_enter_container(reply, 'a', "ay"); + if (r < 0) + return bus_log_parse_error(r); + + while ((r = sd_bus_message_read_array(reply, 'y', (const void**) &p, &sz)) > 0) { + _cleanup_free_ char *escaped = NULL; + + escaped = cescape_length(p, sz); + if (!escaped) + return log_oom(); + + printf("%*s%s\n", (int) indent, "", escaped); + } + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_exit_container(reply); + if (r < 0) + return bus_log_parse_error(r); + + r = sd_bus_message_read(reply, "ssst", &canonical_name, &canonical_type, &canonical_domain, &flags); + if (r < 0) + return bus_log_parse_error(r); + + canonical_name = empty_to_null(canonical_name); + canonical_type = empty_to_null(canonical_type); + + if (!streq_ptr(name, canonical_name) || + !streq_ptr(type, canonical_type) || + !streq_ptr(domain, canonical_domain)) { + + printf("%*s(", (int) indent, ""); + + if (canonical_name) + printf("%s/", canonical_name); + if (canonical_type) + printf("%s/", canonical_type); + + printf("%s)\n", canonical_domain); + } + + print_source(flags, ts); + + return 0; +} + +static int resolve_openpgp(sd_bus *bus, const char *address) { + const char *domain, *full; + int r; + _cleanup_free_ char *hashed = NULL; + + assert(bus); + assert(address); + + domain = strrchr(address, '@'); + if (!domain) { + log_error("Address does not contain '@': \"%s\"", address); + return -EINVAL; + } else if (domain == address || domain[1] == '\0') { + log_error("Address starts or ends with '@': \"%s\"", address); + return -EINVAL; + } + domain++; + + r = string_hashsum_sha256(address, domain - 1 - address, &hashed); + if (r < 0) + return log_error_errno(r, "Hashing failed: %m"); + + strshorten(hashed, 56); + + full = strjoina(hashed, "._openpgpkey.", domain); + log_debug("Looking up \"%s\".", full); + + r = resolve_record(bus, full, + arg_class ?: DNS_CLASS_IN, + arg_type ?: DNS_TYPE_OPENPGPKEY, false); + + if (IN_SET(r, -ENXIO, -ESRCH)) { /* NXDOMAIN or NODATA? */ + hashed = NULL; + r = string_hashsum_sha224(address, domain - 1 - address, &hashed); + if (r < 0) + return log_error_errno(r, "Hashing failed: %m"); + + full = strjoina(hashed, "._openpgpkey.", domain); + log_debug("Looking up \"%s\".", full); + + return resolve_record(bus, full, + arg_class ?: DNS_CLASS_IN, + arg_type ?: DNS_TYPE_OPENPGPKEY, true); + } + + return r; +} + +static int resolve_tlsa(sd_bus *bus, const char *address) { + const char *port; + uint16_t port_num = 443; + _cleanup_free_ char *full = NULL; + int r; + + assert(bus); + assert(address); + + port = strrchr(address, ':'); + if (port) { + r = safe_atou16(port + 1, &port_num); + if (r < 0 || port_num == 0) + return log_error_errno(r, "Invalid port \"%s\".", port + 1); + + address = strndupa(address, port - address); + } + + r = asprintf(&full, "_%u.%s.%s", + port_num, + service_family_to_string(arg_service_family), + address); + if (r < 0) + return log_oom(); + + log_debug("Looking up \"%s\".", full); + + return resolve_record(bus, full, + arg_class ?: DNS_CLASS_IN, + arg_type ?: DNS_TYPE_TLSA, true); +} + +static int show_statistics(sd_bus *bus) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + uint64_t n_current_transactions, n_total_transactions, + cache_size, n_cache_hit, n_cache_miss, + n_dnssec_secure, n_dnssec_insecure, n_dnssec_bogus, n_dnssec_indeterminate; + int r, dnssec_supported; + + assert(bus); + + r = sd_bus_get_property_trivial(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "DNSSECSupported", + &error, + 'b', + &dnssec_supported); + if (r < 0) + return log_error_errno(r, "Failed to get DNSSEC supported state: %s", bus_error_message(&error, r)); + + printf("DNSSEC supported by current servers: %s%s%s\n\n", + ansi_highlight(), + yes_no(dnssec_supported), + ansi_normal()); + + r = sd_bus_get_property(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "TransactionStatistics", + &error, + &reply, + "(tt)"); + if (r < 0) + return log_error_errno(r, "Failed to get transaction statistics: %s", bus_error_message(&error, r)); + + r = sd_bus_message_read(reply, "(tt)", + &n_current_transactions, + &n_total_transactions); + if (r < 0) + return bus_log_parse_error(r); + + printf("%sTransactions%s\n" + "Current Transactions: %" PRIu64 "\n" + " Total Transactions: %" PRIu64 "\n", + ansi_highlight(), + ansi_normal(), + n_current_transactions, + n_total_transactions); + + reply = sd_bus_message_unref(reply); + + r = sd_bus_get_property(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "CacheStatistics", + &error, + &reply, + "(ttt)"); + if (r < 0) + return log_error_errno(r, "Failed to get cache statistics: %s", bus_error_message(&error, r)); + + r = sd_bus_message_read(reply, "(ttt)", + &cache_size, + &n_cache_hit, + &n_cache_miss); + if (r < 0) + return bus_log_parse_error(r); + + printf("\n%sCache%s\n" + " Current Cache Size: %" PRIu64 "\n" + " Cache Hits: %" PRIu64 "\n" + " Cache Misses: %" PRIu64 "\n", + ansi_highlight(), + ansi_normal(), + cache_size, + n_cache_hit, + n_cache_miss); + + reply = sd_bus_message_unref(reply); + + r = sd_bus_get_property(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "DNSSECStatistics", + &error, + &reply, + "(tttt)"); + if (r < 0) + return log_error_errno(r, "Failed to get DNSSEC statistics: %s", bus_error_message(&error, r)); + + r = sd_bus_message_read(reply, "(tttt)", + &n_dnssec_secure, + &n_dnssec_insecure, + &n_dnssec_bogus, + &n_dnssec_indeterminate); + if (r < 0) + return bus_log_parse_error(r); + + printf("\n%sDNSSEC Verdicts%s\n" + " Secure: %" PRIu64 "\n" + " Insecure: %" PRIu64 "\n" + " Bogus: %" PRIu64 "\n" + " Indeterminate: %" PRIu64 "\n", + ansi_highlight(), + ansi_normal(), + n_dnssec_secure, + n_dnssec_insecure, + n_dnssec_bogus, + n_dnssec_indeterminate); + + return 0; +} + +static int reset_statistics(sd_bus *bus) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + int r; + + r = sd_bus_call_method(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResetStatistics", + &error, + NULL, + NULL); + if (r < 0) + return log_error_errno(r, "Failed to reset statistics: %s", bus_error_message(&error, r)); + + return 0; +} + +static int flush_caches(sd_bus *bus) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + int r; + + r = sd_bus_call_method(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "FlushCaches", + &error, + NULL, + NULL); + if (r < 0) + return log_error_errno(r, "Failed to flush caches: %s", bus_error_message(&error, r)); + + return 0; +} + +static int map_link_dns_servers(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) { + char ***l = userdata; + int r; + + assert(bus); + assert(member); + assert(m); + assert(l); + + r = sd_bus_message_enter_container(m, 'a', "(iay)"); + if (r < 0) + return r; + + for (;;) { + const void *a; + char *pretty; + int family; + size_t sz; + + r = sd_bus_message_enter_container(m, 'r', "iay"); + if (r < 0) + return r; + if (r == 0) + break; + + r = sd_bus_message_read(m, "i", &family); + if (r < 0) + return r; + + r = sd_bus_message_read_array(m, 'y', &a, &sz); + if (r < 0) + return r; + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6)) { + log_debug("Unexpected family, ignoring."); + continue; + } + + if (sz != FAMILY_ADDRESS_SIZE(family)) { + log_debug("Address size mismatch, ignoring."); + continue; + } + + r = in_addr_to_string(family, a, &pretty); + if (r < 0) + return r; + + r = strv_consume(l, pretty); + if (r < 0) + return r; + } + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + return 0; +} + +static int map_link_domains(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) { + char ***l = userdata; + int r; + + assert(bus); + assert(member); + assert(m); + assert(l); + + r = sd_bus_message_enter_container(m, 'a', "(sb)"); + if (r < 0) + return r; + + for (;;) { + const char *domain; + int route_only; + char *pretty; + + r = sd_bus_message_read(m, "(sb)", &domain, &route_only); + if (r < 0) + return r; + if (r == 0) + break; + + if (route_only) + pretty = strappend("~", domain); + else + pretty = strdup(domain); + if (!pretty) + return -ENOMEM; + + r = strv_consume(l, pretty); + if (r < 0) + return r; + } + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + return 0; +} + +static int status_ifindex(sd_bus *bus, int ifindex, const char *name, bool *empty_line) { + + struct link_info { + uint64_t scopes_mask; + char *llmnr; + char *mdns; + char *dnssec; + char **dns; + char **domains; + char **ntas; + int dnssec_supported; + } link_info = {}; + + static const struct bus_properties_map property_map[] = { + { "ScopesMask", "t", NULL, offsetof(struct link_info, scopes_mask) }, + { "DNS", "a(iay)", map_link_dns_servers, offsetof(struct link_info, dns) }, + { "Domains", "a(sb)", map_link_domains, offsetof(struct link_info, domains) }, + { "LLMNR", "s", NULL, offsetof(struct link_info, llmnr) }, + { "MulticastDNS", "s", NULL, offsetof(struct link_info, mdns) }, + { "DNSSEC", "s", NULL, offsetof(struct link_info, dnssec) }, + { "DNSSECNegativeTrustAnchors", "as", NULL, offsetof(struct link_info, ntas) }, + { "DNSSECSupported", "b", NULL, offsetof(struct link_info, dnssec_supported) }, + {} + }; + + _cleanup_free_ char *ifi = NULL, *p = NULL; + char ifname[IF_NAMESIZE] = ""; + char **i; + int r; + + assert(bus); + assert(ifindex > 0); + assert(empty_line); + + if (!name) { + if (!if_indextoname(ifindex, ifname)) + return log_error_errno(errno, "Failed to resolve interface name for %i: %m", ifindex); + + name = ifname; + } + + if (asprintf(&ifi, "%i", ifindex) < 0) + return log_oom(); + + r = sd_bus_path_encode("/org/freedesktop/resolve1/link", ifi, &p); + if (r < 0) + return log_oom(); + + r = bus_map_all_properties(bus, + "org.freedesktop.resolve1", + p, + property_map, + &link_info); + if (r < 0) { + log_error_errno(r, "Failed to get link data for %i: %m", ifindex); + goto finish; + } + + pager_open(arg_no_pager, false); + + if (*empty_line) + fputc('\n', stdout); + + printf("%sLink %i (%s)%s\n", + ansi_highlight(), ifindex, name, ansi_normal()); + + if (link_info.scopes_mask == 0) + printf(" Current Scopes: none\n"); + else + printf(" Current Scopes:%s%s%s%s%s\n", + link_info.scopes_mask & SD_RESOLVED_DNS ? " DNS" : "", + link_info.scopes_mask & SD_RESOLVED_LLMNR_IPV4 ? " LLMNR/IPv4" : "", + link_info.scopes_mask & SD_RESOLVED_LLMNR_IPV6 ? " LLMNR/IPv6" : "", + link_info.scopes_mask & SD_RESOLVED_MDNS_IPV4 ? " mDNS/IPv4" : "", + link_info.scopes_mask & SD_RESOLVED_MDNS_IPV6 ? " mDNS/IPv6" : ""); + + printf(" LLMNR setting: %s\n" + "MulticastDNS setting: %s\n" + " DNSSEC setting: %s\n" + " DNSSEC supported: %s\n", + strna(link_info.llmnr), + strna(link_info.mdns), + strna(link_info.dnssec), + yes_no(link_info.dnssec_supported)); + + STRV_FOREACH(i, link_info.dns) { + printf(" %s %s\n", + i == link_info.dns ? "DNS Servers:" : " ", + *i); + } + + STRV_FOREACH(i, link_info.domains) { + printf(" %s %s\n", + i == link_info.domains ? "DNS Domain:" : " ", + *i); + } + + STRV_FOREACH(i, link_info.ntas) { + printf(" %s %s\n", + i == link_info.ntas ? "DNSSEC NTA:" : " ", + *i); + } + + *empty_line = true; + + r = 0; + +finish: + strv_free(link_info.dns); + strv_free(link_info.domains); + free(link_info.llmnr); + free(link_info.mdns); + free(link_info.dnssec); + strv_free(link_info.ntas); + return r; +} + +static int map_global_dns_servers(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) { + char ***l = userdata; + int r; + + assert(bus); + assert(member); + assert(m); + assert(l); + + r = sd_bus_message_enter_container(m, 'a', "(iiay)"); + if (r < 0) + return r; + + for (;;) { + const void *a; + char *pretty; + int family, ifindex; + size_t sz; + + r = sd_bus_message_enter_container(m, 'r', "iiay"); + if (r < 0) + return r; + if (r == 0) + break; + + r = sd_bus_message_read(m, "ii", &ifindex, &family); + if (r < 0) + return r; + + r = sd_bus_message_read_array(m, 'y', &a, &sz); + if (r < 0) + return r; + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + if (ifindex != 0) /* only show the global ones here */ + continue; + + if (!IN_SET(family, AF_INET, AF_INET6)) { + log_debug("Unexpected family, ignoring."); + continue; + } + + if (sz != FAMILY_ADDRESS_SIZE(family)) { + log_debug("Address size mismatch, ignoring."); + continue; + } + + r = in_addr_to_string(family, a, &pretty); + if (r < 0) + return r; + + r = strv_consume(l, pretty); + if (r < 0) + return r; + } + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + return 0; +} + +static int map_global_domains(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) { + char ***l = userdata; + int r; + + assert(bus); + assert(member); + assert(m); + assert(l); + + r = sd_bus_message_enter_container(m, 'a', "(isb)"); + if (r < 0) + return r; + + for (;;) { + const char *domain; + int route_only, ifindex; + char *pretty; + + r = sd_bus_message_read(m, "(isb)", &ifindex, &domain, &route_only); + if (r < 0) + return r; + if (r == 0) + break; + + if (ifindex != 0) /* only show the global ones here */ + continue; + + if (route_only) + pretty = strappend("~", domain); + else + pretty = strdup(domain); + if (!pretty) + return -ENOMEM; + + r = strv_consume(l, pretty); + if (r < 0) + return r; + } + + r = sd_bus_message_exit_container(m); + if (r < 0) + return r; + + return 0; +} + +static int status_global(sd_bus *bus, bool *empty_line) { + + struct global_info { + char **dns; + char **domains; + char **ntas; + } global_info = {}; + + static const struct bus_properties_map property_map[] = { + { "DNS", "a(iiay)", map_global_dns_servers, offsetof(struct global_info, dns) }, + { "Domains", "a(isb)", map_global_domains, offsetof(struct global_info, domains) }, + { "DNSSECNegativeTrustAnchors", "as", NULL, offsetof(struct global_info, ntas) }, + {} + }; + + char **i; + int r; + + assert(bus); + assert(empty_line); + + r = bus_map_all_properties(bus, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + property_map, + &global_info); + if (r < 0) { + log_error_errno(r, "Failed to get global data: %m"); + goto finish; + } + + if (strv_isempty(global_info.dns) && strv_isempty(global_info.domains) && strv_isempty(global_info.ntas)) { + r = 0; + goto finish; + } + + pager_open(arg_no_pager, false); + + printf("%sGlobal%s\n", ansi_highlight(), ansi_normal()); + STRV_FOREACH(i, global_info.dns) { + printf(" %s %s\n", + i == global_info.dns ? "DNS Servers:" : " ", + *i); + } + + STRV_FOREACH(i, global_info.domains) { + printf(" %s %s\n", + i == global_info.domains ? "DNS Domain:" : " ", + *i); + } + + strv_sort(global_info.ntas); + STRV_FOREACH(i, global_info.ntas) { + printf(" %s %s\n", + i == global_info.ntas ? "DNSSEC NTA:" : " ", + *i); + } + + *empty_line = true; + + r = 0; + +finish: + strv_free(global_info.dns); + strv_free(global_info.domains); + strv_free(global_info.ntas); + + return r; +} + +static int status_all(sd_bus *bus) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL; + _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL; + sd_netlink_message *i; + bool empty_line = false; + int r; + + assert(bus); + + r = status_global(bus, &empty_line); + if (r < 0) + return r; + + r = sd_netlink_open(&rtnl); + if (r < 0) + return log_error_errno(r, "Failed to connect to netlink: %m"); + + r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, 0); + if (r < 0) + return rtnl_log_create_error(r); + + r = sd_netlink_message_request_dump(req, true); + if (r < 0) + return rtnl_log_create_error(r); + + r = sd_netlink_call(rtnl, req, 0, &reply); + if (r < 0) + return log_error_errno(r, "Failed to enumerate links: %m"); + + r = 0; + for (i = reply; i; i = sd_netlink_message_next(i)) { + const char *name; + int ifindex, q; + uint16_t type; + + q = sd_netlink_message_get_type(i, &type); + if (q < 0) + return rtnl_log_parse_error(q); + + if (type != RTM_NEWLINK) + continue; + + q = sd_rtnl_message_link_get_ifindex(i, &ifindex); + if (q < 0) + return rtnl_log_parse_error(q); + + if (ifindex == LOOPBACK_IFINDEX) + continue; + + q = sd_netlink_message_read_string(i, IFLA_IFNAME, &name); + if (q < 0) + return rtnl_log_parse_error(q); + + q = status_ifindex(bus, ifindex, name, &empty_line); + if (q < 0 && r >= 0) + r = q; + } + + return r; +} + +static void help_protocol_types(void) { + if (arg_legend) + puts("Known protocol types:"); + puts("dns\nllmnr\nllmnr-ipv4\nllmnr-ipv6"); +} + +static void help_dns_types(void) { + const char *t; + int i; + + if (arg_legend) + puts("Known DNS RR types:"); + for (i = 0; i < _DNS_TYPE_MAX; i++) { + t = dns_type_to_string(i); + if (t) + puts(t); + } +} + +static void help_dns_classes(void) { + const char *t; + int i; + + if (arg_legend) + puts("Known DNS RR classes:"); + for (i = 0; i < _DNS_CLASS_MAX; i++) { + t = dns_class_to_string(i); + if (t) + puts(t); + } +} + +static void help(void) { + printf("%1$s [OPTIONS...] HOSTNAME|ADDRESS...\n" + "%1$s [OPTIONS...] --service [[NAME] TYPE] DOMAIN\n" + "%1$s [OPTIONS...] --openpgp EMAIL@DOMAIN...\n" + "%1$s [OPTIONS...] --statistics\n" + "%1$s [OPTIONS...] --reset-statistics\n" + "\n" + "Resolve domain names, IPv4 and IPv6 addresses, DNS records, and services.\n\n" + " -h --help Show this help\n" + " --version Show package version\n" + " --no-pager Do not pipe output into a pager\n" + " -4 Resolve IPv4 addresses\n" + " -6 Resolve IPv6 addresses\n" + " -i --interface=INTERFACE Look on interface\n" + " -p --protocol=PROTO|help Look via protocol\n" + " -t --type=TYPE|help Query RR with DNS type\n" + " -c --class=CLASS|help Query RR with DNS class\n" + " --service Resolve service (SRV)\n" + " --service-address=BOOL Resolve address for services (default: yes)\n" + " --service-txt=BOOL Resolve TXT records for services (default: yes)\n" + " --openpgp Query OpenPGP public key\n" + " --tlsa Query TLS public key\n" + " --cname=BOOL Follow CNAME redirects (default: yes)\n" + " --search=BOOL Use search domains for single-label names\n" + " (default: yes)\n" + " --raw[=payload|packet] Dump the answer as binary data\n" + " --legend=BOOL Print headers and additional info (default: yes)\n" + " --statistics Show resolver statistics\n" + " --reset-statistics Reset resolver statistics\n" + " --status Show link and server status\n" + " --flush-caches Flush all local DNS caches\n" + , program_invocation_short_name); +} + +static int parse_argv(int argc, char *argv[]) { + enum { + ARG_VERSION = 0x100, + ARG_LEGEND, + ARG_SERVICE, + ARG_CNAME, + ARG_SERVICE_ADDRESS, + ARG_SERVICE_TXT, + ARG_OPENPGP, + ARG_TLSA, + ARG_RAW, + ARG_SEARCH, + ARG_STATISTICS, + ARG_RESET_STATISTICS, + ARG_STATUS, + ARG_FLUSH_CACHES, + ARG_NO_PAGER, + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "type", required_argument, NULL, 't' }, + { "class", required_argument, NULL, 'c' }, + { "legend", required_argument, NULL, ARG_LEGEND }, + { "interface", required_argument, NULL, 'i' }, + { "protocol", required_argument, NULL, 'p' }, + { "cname", required_argument, NULL, ARG_CNAME }, + { "service", no_argument, NULL, ARG_SERVICE }, + { "service-address", required_argument, NULL, ARG_SERVICE_ADDRESS }, + { "service-txt", required_argument, NULL, ARG_SERVICE_TXT }, + { "openpgp", no_argument, NULL, ARG_OPENPGP }, + { "tlsa", optional_argument, NULL, ARG_TLSA }, + { "raw", optional_argument, NULL, ARG_RAW }, + { "search", required_argument, NULL, ARG_SEARCH }, + { "statistics", no_argument, NULL, ARG_STATISTICS, }, + { "reset-statistics", no_argument, NULL, ARG_RESET_STATISTICS }, + { "status", no_argument, NULL, ARG_STATUS }, + { "flush-caches", no_argument, NULL, ARG_FLUSH_CACHES }, + { "no-pager", no_argument, NULL, ARG_NO_PAGER }, + {} + }; + + int c, r; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "h46i:t:c:p:", options, NULL)) >= 0) + switch(c) { + + case 'h': + help(); + return 0; /* done */; + + case ARG_VERSION: + return version(); + + case '4': + arg_family = AF_INET; + break; + + case '6': + arg_family = AF_INET6; + break; + + case 'i': { + int ifi; + + if (parse_ifindex(optarg, &ifi) >= 0) + arg_ifindex = ifi; + else { + ifi = if_nametoindex(optarg); + if (ifi <= 0) + return log_error_errno(errno, "Unknown interface %s: %m", optarg); + + arg_ifindex = ifi; + } + + break; + } + + case 't': + if (streq(optarg, "help")) { + help_dns_types(); + return 0; + } + + r = dns_type_from_string(optarg); + if (r < 0) { + log_error("Failed to parse RR record type %s", optarg); + return r; + } + arg_type = (uint16_t) r; + assert((int) arg_type == r); + + arg_mode = MODE_RESOLVE_RECORD; + break; + + case 'c': + if (streq(optarg, "help")) { + help_dns_classes(); + return 0; + } + + r = dns_class_from_string(optarg); + if (r < 0) { + log_error("Failed to parse RR record class %s", optarg); + return r; + } + arg_class = (uint16_t) r; + assert((int) arg_class == r); + + break; + + case ARG_LEGEND: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --legend= argument"); + + arg_legend = r; + break; + + case 'p': + if (streq(optarg, "help")) { + help_protocol_types(); + return 0; + } else if (streq(optarg, "dns")) + arg_flags |= SD_RESOLVED_DNS; + else if (streq(optarg, "llmnr")) + arg_flags |= SD_RESOLVED_LLMNR; + else if (streq(optarg, "llmnr-ipv4")) + arg_flags |= SD_RESOLVED_LLMNR_IPV4; + else if (streq(optarg, "llmnr-ipv6")) + arg_flags |= SD_RESOLVED_LLMNR_IPV6; + else { + log_error("Unknown protocol specifier: %s", optarg); + return -EINVAL; + } + + break; + + case ARG_SERVICE: + arg_mode = MODE_RESOLVE_SERVICE; + break; + + case ARG_OPENPGP: + arg_mode = MODE_RESOLVE_OPENPGP; + break; + + case ARG_TLSA: + arg_mode = MODE_RESOLVE_TLSA; + arg_service_family = service_family_from_string(optarg); + if (arg_service_family < 0) { + log_error("Unknown service family \"%s\".", optarg); + return -EINVAL; + } + break; + + case ARG_RAW: + if (on_tty()) { + log_error("Refusing to write binary data to tty."); + return -ENOTTY; + } + + if (optarg == NULL || streq(optarg, "payload")) + arg_raw = RAW_PAYLOAD; + else if (streq(optarg, "packet")) + arg_raw = RAW_PACKET; + else { + log_error("Unknown --raw specifier \"%s\".", optarg); + return -EINVAL; + } + + arg_legend = false; + break; + + case ARG_CNAME: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --cname= argument."); + SET_FLAG(arg_flags, SD_RESOLVED_NO_CNAME, r == 0); + break; + + case ARG_SERVICE_ADDRESS: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --service-address= argument."); + SET_FLAG(arg_flags, SD_RESOLVED_NO_ADDRESS, r == 0); + break; + + case ARG_SERVICE_TXT: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --service-txt= argument."); + SET_FLAG(arg_flags, SD_RESOLVED_NO_TXT, r == 0); + break; + + case ARG_SEARCH: + r = parse_boolean(optarg); + if (r < 0) + return log_error_errno(r, "Failed to parse --search argument."); + SET_FLAG(arg_flags, SD_RESOLVED_NO_SEARCH, r == 0); + break; + + case ARG_STATISTICS: + arg_mode = MODE_STATISTICS; + break; + + case ARG_RESET_STATISTICS: + arg_mode = MODE_RESET_STATISTICS; + break; + + case ARG_FLUSH_CACHES: + arg_mode = MODE_FLUSH_CACHES; + break; + + case ARG_STATUS: + arg_mode = MODE_STATUS; + break; + + case ARG_NO_PAGER: + arg_no_pager = true; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached("Unhandled option"); + } + + if (arg_type == 0 && arg_class != 0) { + log_error("--class= may only be used in conjunction with --type=."); + return -EINVAL; + } + + if (arg_type != 0 && arg_mode == MODE_RESOLVE_SERVICE) { + log_error("--service and --type= may not be combined."); + return -EINVAL; + } + + if (arg_type != 0 && arg_class == 0) + arg_class = DNS_CLASS_IN; + + if (arg_class != 0 && arg_type == 0) + arg_type = DNS_TYPE_A; + + return 1 /* work to do */; +} + +int main(int argc, char **argv) { + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + int r; + + log_parse_environment(); + log_open(); + + r = parse_argv(argc, argv); + if (r <= 0) + goto finish; + + r = sd_bus_open_system(&bus); + if (r < 0) { + log_error_errno(r, "sd_bus_open_system: %m"); + goto finish; + } + + switch (arg_mode) { + + case MODE_RESOLVE_HOST: + if (optind >= argc) { + log_error("No arguments passed."); + r = -EINVAL; + goto finish; + } + + while (argv[optind]) { + int family, ifindex, k; + union in_addr_union a; + + if (startswith(argv[optind], "dns:")) + k = resolve_rfc4501(bus, argv[optind]); + else { + k = in_addr_ifindex_from_string_auto(argv[optind], &family, &a, &ifindex); + if (k >= 0) + k = resolve_address(bus, family, &a, ifindex); + else + k = resolve_host(bus, argv[optind]); + } + + if (r == 0) + r = k; + + optind++; + } + break; + + case MODE_RESOLVE_RECORD: + if (optind >= argc) { + log_error("No arguments passed."); + r = -EINVAL; + goto finish; + } + + while (argv[optind]) { + int k; + + k = resolve_record(bus, argv[optind], arg_class, arg_type, true); + if (r == 0) + r = k; + + optind++; + } + break; + + case MODE_RESOLVE_SERVICE: + if (argc < optind + 1) { + log_error("Domain specification required."); + r = -EINVAL; + goto finish; + + } else if (argc == optind + 1) + r = resolve_service(bus, NULL, NULL, argv[optind]); + else if (argc == optind + 2) + r = resolve_service(bus, NULL, argv[optind], argv[optind+1]); + else if (argc == optind + 3) + r = resolve_service(bus, argv[optind], argv[optind+1], argv[optind+2]); + else { + log_error("Too many arguments."); + r = -EINVAL; + goto finish; + } + + break; + + case MODE_RESOLVE_OPENPGP: + if (argc < optind + 1) { + log_error("E-mail address required."); + r = -EINVAL; + goto finish; + + } + + r = 0; + while (optind < argc) { + int k; + + k = resolve_openpgp(bus, argv[optind++]); + if (k < 0) + r = k; + } + break; + + case MODE_RESOLVE_TLSA: + if (argc < optind + 1) { + log_error("Domain name required."); + r = -EINVAL; + goto finish; + + } + + r = 0; + while (optind < argc) { + int k; + + k = resolve_tlsa(bus, argv[optind++]); + if (k < 0) + r = k; + } + break; + + case MODE_STATISTICS: + if (argc > optind) { + log_error("Too many arguments."); + r = -EINVAL; + goto finish; + } + + r = show_statistics(bus); + break; + + case MODE_RESET_STATISTICS: + if (argc > optind) { + log_error("Too many arguments."); + r = -EINVAL; + goto finish; + } + + r = reset_statistics(bus); + break; + + case MODE_FLUSH_CACHES: + if (argc > optind) { + log_error("Too many arguments."); + r = -EINVAL; + goto finish; + } + + r = flush_caches(bus); + break; + + case MODE_STATUS: + + if (argc > optind) { + char **ifname; + bool empty_line = false; + + r = 0; + STRV_FOREACH(ifname, argv + optind) { + int ifindex, q; + + q = parse_ifindex(argv[optind], &ifindex); + if (q < 0) { + ifindex = if_nametoindex(argv[optind]); + if (ifindex <= 0) { + log_error_errno(errno, "Failed to resolve interface name: %s", argv[optind]); + continue; + } + } + + q = status_ifindex(bus, ifindex, NULL, &empty_line); + if (q < 0 && r >= 0) + r = q; + } + } else + r = status_all(bus); + + break; + } + +finish: + pager_close(); + + return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE; +} diff --git a/src/grp-resolve/systemd-resolve/systemd-resolve.completion.bash b/src/grp-resolve/systemd-resolve/systemd-resolve.completion.bash new file mode 100644 index 0000000000..f59482fe23 --- /dev/null +++ b/src/grp-resolve/systemd-resolve/systemd-resolve.completion.bash @@ -0,0 +1,64 @@ +# systemd-resolve(1) completion -*- shell-script -*- +# +# This file is part of systemd. +# +# Copyright 2016 Zbigniew Jędrzejewski-Szmek +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. + +__contains_word () { + local w word=$1; shift + for w in "$@"; do + [[ $w = "$word" ]] && return + done +} + +__get_interfaces(){ + { cd /sys/class/net && echo *; } | \ + while read -d' ' -r name; do + [[ "$name" != "lo" ]] && echo "$name" + done +} + +_systemd-resolve() { + local i comps + local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]} + local -A OPTS=( + [STANDALONE]='-h --help --version -4 -6 + --service --openpgp --tlsa --status --statistics + --reset-statistics --service-address=no --service-txt=no + --cname=no --search=no --legend=no' + [ARG]='-i --interface -p --protocol -t --type -c --class' + ) + + if __contains_word "$prev" ${OPTS[ARG]}; then + case $prev in + --interface|-i) + comps=$( __get_interfaces ) + ;; + --protocol|-p|--type|-t|--class|-c) + comps=$( systemd-resolve --legend=no "$prev" help; echo help ) + ;; + esac + COMPREPLY=( $(compgen -W '$comps' -- "$cur") ) + return 0 + fi + + if [[ "$cur" = -* ]]; then + COMPREPLY=( $(compgen -W '${OPTS[*]}' -- "$cur") ) + return 0 + fi +} + +complete -F _systemd-resolve systemd-resolve diff --git a/src/grp-resolve/systemd-resolve/systemd-resolve.completion.zsh b/src/grp-resolve/systemd-resolve/systemd-resolve.completion.zsh new file mode 100644 index 0000000000..c318ab50f1 --- /dev/null +++ b/src/grp-resolve/systemd-resolve/systemd-resolve.completion.zsh @@ -0,0 +1,64 @@ +#compdef systemd-resolve + +# +# This file is part of systemd. +# +# Copyright 2016 Zbigniew Jędrzejewski-Szmek +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. + +_dns_protocol() { + local -a _protocol + _protocol=( $(_call_program protocol ${service} --legend=no --protocol help; echo help) ) + _values 'protocol' "$_protocol[@]" +} + +_dns_type() { + local -a _type + _type=( $(_call_program type ${service} --legend=no --type help; echo help) ) + _values 'type' "$_type[@]" +} + +_dns_class() { + local -a _class + _class=( $(_call_program class ${service} --legend=no --class help; echo help) ) + _values 'class' "$_class[@]" +} + +_systemd-resolve_none() { + _alternative : \ + 'domain:DNS address:' \ + 'address:email address:' +} + +_arguments \ + {-h,--help}'[Print a short help text and exit]' \ + '--version[Print a short version string and exit]' \ + '--legend=no[Do not show headers and footers]' \ + '-4[Resolve IPv4 addresses]' \ + '-6[Resolve IPv6 addresses]' \ + {-i+,--interface=}'[Look on interface]:interface:_net_interfaces' \ + {-p+,--protocol=}'[Look via protocol]:protocol:_dns_protocol' \ + {-t+,--type=}'[Query RR with DNS type]:type:_dns_type' \ + {-c+,--class=}'[Query RR with DNS class]:class:_dns_class' \ + '--service[Resolve services]' \ + '--service-address=no[Do not resolve address for services]' \ + '--service-txt=no[Do not resolve TXT records for services]' \ + '--openpgp[Query OpenPGP public key]' \ + '--tlsa[Query TLS public key]' \ + '--cname=no[Do not follow CNAME redirects]' \ + '--search=no[Do not use search domains]' \ + '--statistics[Show resolver statistics]' \ + '--reset-statistics[Reset resolver statistics]' \ + '*::default: _systemd-resolve_none' diff --git a/src/grp-resolve/systemd-resolve/systemd-resolve.xml b/src/grp-resolve/systemd-resolve/systemd-resolve.xml new file mode 100644 index 0000000000..2bc917ac26 --- /dev/null +++ b/src/grp-resolve/systemd-resolve/systemd-resolve.xml @@ -0,0 +1,394 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" +"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="systemd-resolve" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>systemd-resolve</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-resolve</refentrytitle> + <manvolnum>1</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-resolve</refname> + <refpurpose>Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain" rep="repeat"><replaceable>HOSTNAME</replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <arg choice="plain" rep="repeat"><replaceable>ADDRESS</replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --type=<replaceable>TYPE</replaceable></command> + <arg choice="plain" rep="repeat"><replaceable>DOMAIN</replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --service</command> + <arg choice="plain"><arg choice="opt"><arg choice="opt"><replaceable>NAME</replaceable></arg> + <replaceable>TYPE</replaceable></arg> <replaceable>DOMAIN</replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --openpgp</command> + <arg choice="plain"><replaceable>USER@DOMAIN</replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --tlsa</command> + <arg choice="plain"><replaceable>DOMAIN<optional>:PORT</optional></replaceable></arg> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --statistics</command> + </cmdsynopsis> + + <cmdsynopsis> + <command>systemd-resolve</command> + <arg choice="opt" rep="repeat">OPTIONS</arg> + <command> --reset-statistics</command> + </cmdsynopsis> + + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>systemd-resolve</command> may be used to resolve domain names, IPv4 and IPv6 addresses, DNS resource + records and services with the + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + resolver service. By default, the specified list of parameters will be resolved as hostnames, retrieving their IPv4 + and IPv6 addresses. If the parameters specified are formatted as IPv4 or IPv6 operation the reverse operation is + done, and a hostname is retrieved for the specified addresses.</para> + + <para>The program's output contains information about the protocol used for the look-up and on which network + interface the data was discovered. It also contains information on whether the information could be + authenticated. All data for which local DNSSEC validation succeeds is considered authenticated. Moreover all data + originating from local, trusted sources is also reported authenticated, including resolution of the local host + name, the <literal>localhost</literal> host name or all data from <filename>/etc/hosts</filename>.</para> + + <para>The <option>--type=</option> switch may be used to specify a DNS resource record type (A, AAAA, SOA, MX, ...) in + order to request a specific DNS resource record, instead of the address or reverse address lookups. + The special value <literal>help</literal> may be used to list known values.</para> + + <para>The <option>--service</option> switch may be used to resolve <ulink + url="https://tools.ietf.org/html/rfc2782">SRV</ulink> and <ulink + url="https://tools.ietf.org/html/rfc6763">DNS-SD</ulink> services (see below). In this mode, between one and three + arguments are required. If three parameters are passed the first is assumed to be the DNS-SD service name, the + second the SRV service type, and the third the domain to search in. In this case a full DNS-SD style SRV and TXT + lookup is executed. If only two parameters are specified, the first is assumed to be the SRV service type, and the + second the domain to look in. In this case no TXT RR is requested. Finally, if only one parameter is specified, it + is assumed to be a domain name, that is already prefixed with an SRV type, and an SRV lookup is done (no + TXT).</para> + + <para>The <option>--openpgp</option> switch may be used to query PGP keys stored as + <ulink url="https://tools.ietf.org/html/rfc7929">OPENPGPKEY</ulink> resource records. + When this option is specified one or more e-mail address must be specified.</para> + + <para>The <option>--tlsa</option> switch maybe be used to query TLS public + keys stored as + <ulink url="https://tools.ietf.org/html/rfc6698">TLSA</ulink> resource records. + When this option is specified one or more domain names must be specified.</para> + + <para>The <option>--statistics</option> switch may be used to show resolver statistics, including information about + the number of successful and failed DNSSEC validations.</para> + + <para>The <option>--reset-statistics</option> may be used to reset various statistics counters maintained the + resolver, including those shown in the <option>--statistics</option> output. This operation requires root + privileges.</para> + </refsect1> + + <refsect1> + <title>Options</title> + <variablelist> + <varlistentry> + <term><option>-4</option></term> + <term><option>-6</option></term> + + <listitem><para>By default, when resolving a hostname, both IPv4 and IPv6 + addresses are acquired. By specifying <option>-4</option> only IPv4 addresses are requested, by specifying + <option>-6</option> only IPv6 addresses are requested.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>-i</option> <replaceable>INTERFACE</replaceable></term> + <term><option>--interface=</option><replaceable>INTERFACE</replaceable></term> + + <listitem><para>Specifies the network interface to execute the query on. This may either be specified as numeric + interface index or as network interface string (e.g. <literal>en0</literal>). Note that this option has no + effect if system-wide DNS configuration (as configured in <filename>/etc/resolv.conf</filename> or + <filename>/etc/systemd/resolve.conf</filename>) in place of per-link configuration is used.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>-p</option> <replaceable>PROTOCOL</replaceable></term> + <term><option>--protocol=</option><replaceable>PROTOCOL</replaceable></term> + + <listitem><para>Specifies the network protocol for the query. May be one of <literal>dns</literal> + (i.e. classic unicast DNS), <literal>llmnr</literal> (<ulink + url="https://tools.ietf.org/html/rfc4795">Link-Local Multicast Name Resolution</ulink>), + <literal>llmnr-ipv4</literal>, <literal>llmnr-ipv6</literal> (LLMNR via the indicated underlying IP + protocols). By default the lookup is done via all protocols suitable for the lookup. If used, limits the set of + protocols that may be used. Use this option multiple times to enable resolving via multiple protocols at the + same time. The setting <literal>llmnr</literal> is identical to specifying this switch once with + <literal>llmnr-ipv4</literal> and once via <literal>llmnr-ipv6</literal>. Note that this option does not force + the service to resolve the operation with the specified protocol, as that might require a suitable network + interface and configuration. + The special value <literal>help</literal> may be used to list known values. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><option>-t</option> <replaceable>TYPE</replaceable></term> + <term><option>--type=</option><replaceable>TYPE</replaceable></term> + <term><option>-c</option> <replaceable>CLASS</replaceable></term> + <term><option>--class=</option><replaceable>CLASS</replaceable></term> + + <listitem><para>Specifies the DNS resource record type (e.g. A, AAAA, MX, …) and class (e.g. IN, ANY, …) to + look up. If these options are used a DNS resource record set matching the specified class and type is + requested. The class defaults to IN if only a type is specified. + The special value <literal>help</literal> may be used to list known values. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--service</option></term> + + <listitem><para>Enables service resolution. This enables DNS-SD and simple SRV service resolution, depending + on the specified list of parameters (see above).</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--service-address=</option><replaceable>BOOL</replaceable></term> + + <listitem><para>Takes a boolean parameter. If true (the default), when doing a service lookup with + <option>--service</option> the hostnames contained in the SRV resource records are resolved as well.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--service-txt=</option><replaceable>BOOL</replaceable></term> + + <listitem><para>Takes a boolean parameter. If true (the default), when doing a DNS-SD service lookup with + <option>--service</option> the TXT service metadata record is resolved as well.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--openpgp</option></term> + + <listitem><para>Enables OPENPGPKEY resource record resolution (see above). Specified e-mail + addresses are converted to the corresponding DNS domain name, and any OPENPGPKEY keys are + printed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--tlsa</option></term> + + <listitem><para>Enables TLSA resource record resolution (see above). + A query will be performed for each of the specified names prefixed with + the port and family + (<literal>_<replaceable>port</replaceable>._<replaceable>family</replaceable>.<replaceable>domain</replaceable></literal>). + The port number may be specified after a colon + (<literal>:</literal>), otherwise <constant>443</constant> will be used + by default. The family may be specified as an argument after + <option>--tlsa</option>, otherwise <constant>tcp</constant> will be + used.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--cname=</option><replaceable>BOOL</replaceable></term> + + <listitem><para>Takes a boolean parameter. If true (the default), DNS CNAME or DNAME redirections are + followed. Otherwise, if a CNAME or DNAME record is encountered while resolving, an error is + returned.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--search=</option><replaceable>BOOL</replaceable></term> + + <listitem><para>Takes a boolean parameter. If true (the default), any specified single-label hostnames will be + searched in the domains configured in the search domain list, if it is non-empty. Otherwise, the search domain + logic is disabled.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--raw</option><optional>=payload|packet</optional></term> + + <listitem><para>Dump the answer as binary data. If there is no argument or if the argument is + <literal>payload</literal>, the payload of the packet is exported. If the argument is + <literal>packet</literal>, the whole packet is dumped in wire format, prefixed by + length specified as a little-endian 64-bit number. This format allows multiple packets + to be dumped and unambigously parsed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--legend=</option><replaceable>BOOL</replaceable></term> + + <listitem><para>Takes a boolean parameter. If true (the default), column headers and meta information about the + query response are shown. Otherwise, this output is suppressed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--statistics</option></term> + + <listitem><para>If specified general resolver statistics are shown, including information whether DNSSEC is + enabled and available, as well as resolution and validation statistics.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--reset-statistics</option></term> + + <listitem><para>Resets the statistics counters shown in <option>--statistics</option> to zero.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--flush-caches</option></term> + + <listitem><para>Flushes all DNS resource record caches the service maintains locally.</para></listitem> + </varlistentry> + + <varlistentry> + <term><option>--status</option></term> + + <listitem><para>Shows the global and per-link DNS settings in currently in effect.</para></listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="version" /> + <xi:include href="standard-options.xml" xpointer="no-pager" /> + </variablelist> + </refsect1> + + <refsect1> + <title>Examples</title> + + <example> + <title>Retrieve the addresses of the <literal>www.0pointer.net</literal> domain</title> + + <programlisting>$ systemd-resolve www.0pointer.net +www.0pointer.net: 2a01:238:43ed:c300:10c3:bcf3:3266:da74 + 85.214.157.71 + +-- Information acquired via protocol DNS in 611.6ms. +-- Data is authenticated: no +</programlisting> + </example> + + <example> + <title>Retrieve the domain of the <literal>85.214.157.71</literal> IP address</title> + + <programlisting>$ systemd-resolve 85.214.157.71 +85.214.157.71: gardel.0pointer.net + +-- Information acquired via protocol DNS in 1.2997s. +-- Data is authenticated: no +</programlisting> + </example> + + <example> + <title>Retrieve the MX record of the <literal>yahoo.com</literal> domain</title> + + <programlisting>$ systemd-resolve -t MX yahoo.com --legend=no +yahoo.com. IN MX 1 mta7.am0.yahoodns.net +yahoo.com. IN MX 1 mta6.am0.yahoodns.net +yahoo.com. IN MX 1 mta5.am0.yahoodns.net +</programlisting> + </example> + + <example> + <title>Resolve an SRV service</title> + + <programlisting>$ systemd-resolve --service _xmpp-server._tcp gmail.com +_xmpp-server._tcp/gmail.com: alt1.xmpp-server.l.google.com:5269 [priority=20, weight=0] + 173.194.210.125 + alt4.xmpp-server.l.google.com:5269 [priority=20, weight=0] + 173.194.65.125 + ... +</programlisting> + </example> + + <example> + <title>Retrieve a PGP key</title> + + <programlisting>$ systemd-resolve --openpgp zbyszek@fedoraproject.org +d08ee310438ca124a6149ea5cc21b6313b390dce485576eff96f8722._openpgpkey.fedoraproject.org. IN OPENPGPKEY + mQINBFBHPMsBEACeInGYJCb+7TurKfb6wGyTottCDtiSJB310i37/6ZYoeIay/5soJjlMyf + MFQ9T2XNT/0LM6gTa0MpC1st9LnzYTMsT6tzRly1D1UbVI6xw0g0vE5y2Cjk3xUwAynCsSs + ... +</programlisting> + </example> + + <example> + <title>Retrieve a TLS key (<literal>=tcp</literal> and + <literal>:443</literal> could be skipped)</title> + + <programlisting>$ systemd-resolve --tlsa=tcp fedoraproject.org:443 +_443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0c9d506c0e504c06c16d7cb17c0 + -- Cert. usage: CA constraint + -- Selector: Full Certificate + -- Matching type: SHA-256 +</programlisting> + </example> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> +</refentry> diff --git a/src/grp-resolve/systemd-resolved/.gitignore b/src/grp-resolve/systemd-resolved/.gitignore new file mode 100644 index 0000000000..f0835923b7 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/.gitignore @@ -0,0 +1,6 @@ +/resolved-gperf.c +/resolved.conf +/dns_type-from-name.gperf +/dns_type-from-name.h +/dns_type-list.txt +/dns_type-to-name.h diff --git a/src/grp-resolve/systemd-resolved/GNUmakefile b/src/grp-resolve/systemd-resolved/GNUmakefile new file mode 120000 index 0000000000..95e5924740 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/GNUmakefile @@ -0,0 +1 @@ +../../../GNUmakefile
\ No newline at end of file diff --git a/src/grp-resolve/systemd-resolved/Makefile b/src/grp-resolve/systemd-resolved/Makefile new file mode 100644 index 0000000000..e8ae8ccc28 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/Makefile @@ -0,0 +1,127 @@ +# -*- Mode: makefile; indent-tabs-mode: t -*- +# +# This file is part of systemd. +# +# Copyright 2010-2012 Lennart Poettering +# Copyright 2010-2012 Kay Sievers +# Copyright 2013 Zbigniew Jędrzejewski-Szmek +# Copyright 2013 David Strauss +# Copyright 2016 Luke Shumaker +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# systemd is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with systemd; If not, see <http://www.gnu.org/licenses/>. +include $(dir $(lastword $(MAKEFILE_LIST)))/../../../config.mk +include $(topsrcdir)/build-aux/Makefile.head.mk + +ifneq ($(ENABLE_RESOLVED),) + +systemd_resolved_SOURCES = \ + src/resolve/resolved.c \ + src/resolve/resolved-manager.c \ + src/resolve/resolved-manager.h \ + src/resolve/resolved-conf.c \ + src/resolve/resolved-conf.h \ + src/resolve/resolved-resolv-conf.c \ + src/resolve/resolved-resolv-conf.h \ + src/resolve/resolved-bus.c \ + src/resolve/resolved-bus.h \ + src/resolve/resolved-link.h \ + src/resolve/resolved-link.c \ + src/resolve/resolved-link-bus.c \ + src/resolve/resolved-link-bus.h \ + src/resolve/resolved-llmnr.h \ + src/resolve/resolved-llmnr.c \ + src/resolve/resolved-mdns.h \ + src/resolve/resolved-mdns.c \ + src/resolve/resolved-def.h \ + $(basic_dns_sources) \ + src/resolve/resolved-dns-query.h \ + src/resolve/resolved-dns-query.c \ + src/resolve/resolved-dns-synthesize.h \ + src/resolve/resolved-dns-synthesize.c \ + src/resolve/resolved-dns-transaction.h \ + src/resolve/resolved-dns-transaction.c \ + src/resolve/resolved-dns-scope.h \ + src/resolve/resolved-dns-scope.c \ + src/resolve/resolved-dns-server.h \ + src/resolve/resolved-dns-server.c \ + src/resolve/resolved-dns-search-domain.h \ + src/resolve/resolved-dns-search-domain.c \ + src/resolve/resolved-dns-cache.h \ + src/resolve/resolved-dns-cache.c \ + src/resolve/resolved-dns-zone.h \ + src/resolve/resolved-dns-zone.c \ + src/resolve/resolved-dns-stream.h \ + src/resolve/resolved-dns-stream.c \ + src/resolve/resolved-dns-trust-anchor.h \ + src/resolve/resolved-dns-trust-anchor.c \ + src/resolve/resolved-dns-stub.h \ + src/resolve/resolved-dns-stub.c \ + src/resolve/resolved-etc-hosts.h \ + src/resolve/resolved-etc-hosts.c \ + src/shared/gcrypt-util.c \ + src/shared/gcrypt-util.h + +nodist_systemd_resolved_SOURCES = \ + src/resolve/dns_type-from-name.h \ + src/resolve/dns_type-to-name.h \ + src/resolve/resolved-gperf.c + +systemd_resolved_CFLAGS = \ + $(GCRYPT_CFLAGS) + +systemd_resolved_LDADD = \ + libsystemd-network.la \ + libsystemd-shared.la \ + $(GCRYPT_LIBS) \ + -lm + +rootlibexec_PROGRAMS += \ + systemd-resolved + +nodist_systemunit_DATA += \ + units/systemd-resolved.service + +dist_systemunit_DATA_busnames += \ + units/org.freedesktop.resolve1.busname + +dist_dbuspolicy_DATA += \ + src/resolve/org.freedesktop.resolve1.conf + +dist_dbussystemservice_DATA += \ + src/resolve/org.freedesktop.resolve1.service + +SYSTEM_UNIT_ALIASES += \ + systemd-resolved.service dbus-org.freedesktop.resolve1.service + +BUSNAMES_TARGET_WANTS += \ + org.freedesktop.resolve1.busname + +GENERAL_ALIASES += \ + $(systemunitdir)/systemd-resolved.service $(pkgsysconfdir)/system/multi-user.target.wants/systemd-resolved.service + +nodist_pkgsysconf_DATA += \ + src/resolve/resolved.conf + +endif # ENABLE_RESOLVED +gperf_gperf_sources += \ + src/resolve/resolved-gperf.gperf + +EXTRA_DIST += \ + units/systemd-resolved.service.m4.in \ + src/resolve/resolved.conf.in + +dist_rootlibexec_DATA += \ + src/resolve/resolv.conf + +include $(topsrcdir)/build-aux/Makefile.tail.mk diff --git a/src/grp-resolve/systemd-resolved/RFCs b/src/grp-resolve/systemd-resolved/RFCs new file mode 100644 index 0000000000..09c85f9518 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/RFCs @@ -0,0 +1,59 @@ +Y = Comprehensively Implemented, to the point appropriate for resolved +D = Comprehensively Implemented, by a dependency of resolved +! = Missing and something we might want to implement +~ = Needs no explicit support or doesn't apply +? = Is this relevant today? + = We are working on this + +Y https://tools.ietf.org/html/rfc1034 → DOMAIN NAMES - CONCEPTS AND FACILITIES +Y https://tools.ietf.org/html/rfc1035 → DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION +? https://tools.ietf.org/html/rfc1101 → DNS Encoding of Network Names and Other Types +Y https://tools.ietf.org/html/rfc1123 → Requirements for Internet Hosts — Application and Support +~ https://tools.ietf.org/html/rfc1464 → Using the Domain Name System To Store Arbitrary String Attributes +Y https://tools.ietf.org/html/rfc1536 → Common DNS Implementation Errors and Suggested Fixes +Y https://tools.ietf.org/html/rfc1876 → A Means for Expressing Location Information in the Domain Name System +Y https://tools.ietf.org/html/rfc2181 → Clarifications to the DNS Specification +Y https://tools.ietf.org/html/rfc2308 → Negative Caching of DNS Queries (DNS NCACHE) +Y https://tools.ietf.org/html/rfc2782 → A DNS RR for specifying the location of services (DNS SRV) +D https://tools.ietf.org/html/rfc3492 → Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA) +Y https://tools.ietf.org/html/rfc3596 → DNS Extensions to Support IP Version 6 +Y https://tools.ietf.org/html/rfc3597 → Handling of Unknown DNS Resource Record (RR) Types +Y https://tools.ietf.org/html/rfc4033 → DNS Security Introduction and Requirements +Y https://tools.ietf.org/html/rfc4034 → Resource Records for the DNS Security Extensions +Y https://tools.ietf.org/html/rfc4035 → Protocol Modifications for the DNS Security Extensions +! https://tools.ietf.org/html/rfc4183 → A Suggested Scheme for DNS Resolution of Networks and Gateways +Y https://tools.ietf.org/html/rfc4255 → Using DNS to Securely Publish Secure Shell (SSH) Key Fingerprints +Y https://tools.ietf.org/html/rfc4343 → Domain Name System (DNS) Case Insensitivity Clarification +~ https://tools.ietf.org/html/rfc4470 → Minimally Covering NSEC Records and DNSSEC On-line Signing +Y https://tools.ietf.org/html/rfc4501 → Domain Name System Uniform Resource Identifiers +Y https://tools.ietf.org/html/rfc4509 → Use of SHA-256 in DNSSEC Delegation Signer (DS) Resource Records (RRs) +~ https://tools.ietf.org/html/rfc4592 → The Role of Wildcards in the Domain Name System +~ https://tools.ietf.org/html/rfc4697 → Observed DNS Resolution Misbehavior +Y https://tools.ietf.org/html/rfc4795 → Link-Local Multicast Name Resolution (LLMNR) +Y https://tools.ietf.org/html/rfc5011 → Automated Updates of DNS Security (DNSSEC) Trust Anchors +Y https://tools.ietf.org/html/rfc5155 → DNS Security (DNSSEC) Hashed Authenticated Denial of Existence +Y https://tools.ietf.org/html/rfc5452 → Measures for Making DNS More Resilient against Forged Answers +Y https://tools.ietf.org/html/rfc5702 → Use of SHA-2 Algorithms with RSA in DNSKEY and RRSIG Resource Records for DNSSEC +Y https://tools.ietf.org/html/rfc5890 → Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework +Y https://tools.ietf.org/html/rfc5891 → Internationalized Domain Names in Applications (IDNA): Protocol +Y https://tools.ietf.org/html/rfc5966 → DNS Transport over TCP - Implementation Requirements +Y https://tools.ietf.org/html/rfc6303 → Locally Served DNS Zones +Y https://tools.ietf.org/html/rfc6604 → xNAME RCODE and Status Bits Clarification +Y https://tools.ietf.org/html/rfc6605 → Elliptic Curve Digital Signature Algorithm (DSA) for DNSSEC + https://tools.ietf.org/html/rfc6672 → DNAME Redirection in the DNS +! https://tools.ietf.org/html/rfc6731 → Improved Recursive DNS Server Selection for Multi-Interfaced Nodes +Y https://tools.ietf.org/html/rfc6761 → Special-Use Domain Names + https://tools.ietf.org/html/rfc6762 → Multicast DNS + https://tools.ietf.org/html/rfc6763 → DNS-Based Service Discovery +~ https://tools.ietf.org/html/rfc6781 → DNSSEC Operational Practices, Version 2 +Y https://tools.ietf.org/html/rfc6840 → Clarifications and Implementation Notes for DNS Security (DNSSEC) +Y https://tools.ietf.org/html/rfc6891 → Extension Mechanisms for DNS (EDNS(0)) +Y https://tools.ietf.org/html/rfc6944 → Applicability Statement: DNS Security (DNSSEC) DNSKEY Algorithm Implementation Status +Y https://tools.ietf.org/html/rfc6975 → Signaling Cryptographic Algorithm Understanding in DNS Security Extensions (DNSSEC) +Y https://tools.ietf.org/html/rfc7129 → Authenticated Denial of Existence in the DNS +Y https://tools.ietf.org/html/rfc7646 → Definition and Use of DNSSEC Negative Trust Anchors +~ https://tools.ietf.org/html/rfc7719 → DNS Terminology + +Also relevant: + + https://www.iab.org/documents/correspondence-reports-documents/2013-2/iab-statement-dotless-domains-considered-harmful/ diff --git a/src/grp-resolve/systemd-resolved/dnssec-trust-anchors.d.xml b/src/grp-resolve/systemd-resolved/dnssec-trust-anchors.d.xml new file mode 100644 index 0000000000..9a28862ceb --- /dev/null +++ b/src/grp-resolve/systemd-resolved/dnssec-trust-anchors.d.xml @@ -0,0 +1,198 @@ +<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="dnssec-trust-anchors.d" conditional='ENABLE_RESOLVED' + xmlns:xi="http://www.w3.org/2001/XInclude"> + <refentryinfo> + <title>dnssec-trust-anchors.d</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>dnssec-trust-anchors.d</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>dnssec-trust-anchors.d</refname> + <refname>systemd.positive</refname> + <refname>systemd.negative</refname> + <refpurpose>DNSSEC trust anchor configuration files</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/etc/dnssec-trust-anchors.d/*.positive</filename></para> + <para><filename>/run/dnssec-trust-anchors.d/*.positive</filename></para> + <para><filename>/usr/lib/dnssec-trust-anchors.d/*.positive</filename></para> + <para><filename>/etc/dnssec-trust-anchors.d/*.negative</filename></para> + <para><filename>/run/dnssec-trust-anchors.d/*.negative</filename></para> + <para><filename>/usr/lib/dnssec-trust-anchors.d/*.negative</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>The DNSSEC trust anchor configuration files define positive + and negative trust anchors + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + bases DNSSEC integrity proofs on.</para> + </refsect1> + + <refsect1> + <title>Positive Trust Anchors</title> + + <para>Positive trust anchor configuration files contain DNSKEY and + DS resource record definitions to use as base for DNSSEC integrity + proofs. See <ulink + url="https://tools.ietf.org/html/rfc4035#section-4.4">RFC 4035, + Section 4.4</ulink> for more information about DNSSEC trust + anchors.</para> + + <para>Positive trust anchors are read from files with the suffix + <filename>.positive</filename> located in + <filename>/etc/dnssec-trust-anchors.d/</filename>, + <filename>/run/dnssec-trust-anchors.d/</filename> and + <filename>/usr/lib/dnssec-trust-anchors.d/</filename>. These + directories are searched in the specified order, and a trust + anchor file of the same name in an earlier path overrides a trust + anchor files in a later path. To disable a trust anchor file + shipped in <filename>/usr/lib/dnssec-trust-anchors.d/</filename> + it is sufficient to provide an identically-named file in + <filename>/etc/dnssec-trust-anchors.d/</filename> or + <filename>/run/dnssec-trust-anchors.d/</filename> that is either + empty or a symlink to <filename>/dev/null</filename> ("masked").</para> + + <para>Positive trust anchor files are simple text files resembling + DNS zone files, as documented in <ulink + url="https://tools.ietf.org/html/rfc1035#section-5">RFC 1035, Section + 5</ulink>. One DS or DNSKEY resource record may be listed per + line. Empty lines and lines starting with a semicolon + (<literal>;</literal>) are ignored and considered comments. A DS + resource record is specified like in the following example:</para> + + <programlisting>. IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5</programlisting> + + <para>The first word specifies the domain, use + <literal>.</literal> for the root domain. The domain may be + specified with or without trailing dot, which is considered + equivalent. The second word must be <literal>IN</literal> the + third word <literal>DS</literal>. The following words specify the + key tag, signature algorithm, digest algorithm, followed by the + hex-encoded key fingerprint. See <ulink + url="https://tools.ietf.org/html/rfc4034#section-5">RFC 4034, + Section 5</ulink> for details about the precise syntax and meaning + of these fields.</para> + + <para>Alternatively, DNSKEY resource records may be used to define + trust anchors, like in the following example:</para> + + <programlisting>. IN DNSKEY 257 3 8 AwEAAagAIKlVZrpC6Ia7gEzahOR+9W29euxhJhVVLOyQbSEW0O8gcCjFFVQUTf6v58fLjwBd0YI0EzrAcQqBGCzh/RStIoO8g0NfnfL2MTJRkxoXbfDaUeVPQuYEhg37NZWAJQ9VnMVDxP/VHL496M/QZxkjf5/Efucp2gaDX6RS6CXpoY68LsvPVjR0ZSwzz1apAzvN9dlzEheX7ICJBBtuA6G3LQpzW5hOA2hzCTMjJPJ8LbqF6dsV6DoBQzgul0sGIcGOYl7OyQdXfZ57relSQageu+ipAdTTJ25AsRTAoub8ONGcLmqrAmRLKBP1dfwhYB4N7knNnulqQxA+Uk1ihz0=</programlisting> + + <para>The first word specifies the domain again, the second word + must be <literal>IN</literal>, followed by + <literal>DNSKEY</literal>. The subsequent words encode the DNSKEY + flags, protocol and algorithm fields, followed by the key data + encoded in Base64. See <ulink + url="https://tools.ietf.org/html/rfc4034#section-2">RFC 4034, + Section 2</ulink> for details about the precise syntax and meaning + of these fields.</para> + + <para>If multiple DS or DNSKEY records are defined for the same + domain (possibly even in different trust anchor files), all keys + are used and are considered equivalent as base for DNSSEC + proofs.</para> + + <para>Note that <filename>systemd-resolved</filename> will + automatically use a built-in trust anchor key for the Internet + root domain if no positive trust anchors are defined for the root + domain. In most cases it is hence unnecessary to define an + explicit key with trust anchor files. The built-in key is disabled + as soon as at least one trust anchor key for the root domain is + defined in trust anchor files.</para> + + <para>It is generally recommended to encode trust anchors in DS + resource records, rather than DNSKEY resource records.</para> + + <para>If a trust anchor specified via a DS record is found revoked + it is automatically removed from the trust anchor database for the + runtime. See <ulink url="https://tools.ietf.org/html/rfc5011">RFC + 5011</ulink> for details about revoked trust anchors. Note that + <filename>systemd-resolved</filename> will not update its trust + anchor database from DNS servers automatically. Instead, it is + recommended to update the resolver software or update the new + trust anchor via adding in new trust anchor files.</para> + + <para>The current DNSSEC trust anchor for the Internet's root + domain is available at the <ulink + url="https://data.iana.org/root-anchors/root-anchors.xml">IANA + Trust Anchor and Keys</ulink> page.</para> + </refsect1> + + <refsect1> + <title>Negative Trust Anchors</title> + + <para>Negative trust anchors define domains where DNSSEC validation shall be turned + off. Negative trust anchor files are found at the same location as positive trust anchor files, + and follow the same overriding rules. They are text files with the + <filename>.negative</filename> suffix. Empty lines and lines whose first character is + <literal>;</literal> are ignored. Each line specifies one domain name which is the root of a DNS + subtree where validation shall be disabled.</para> + + <para>Negative trust anchors are useful to support private DNS + subtrees that are not referenced from the Internet DNS hierarchy, + and not signed.</para> + + <para><ulink url="https://tools.ietf.org/html/rfc7646">RFC + 7646</ulink> for details on negative trust anchors.</para> + + <para>If no negative trust anchor files are configured a built-in + set of well-known private DNS zone domains is used as negative + trust anchors.</para> + + <para>It is also possibly to define per-interface negative trust + anchors using the <varname>DNSSECNegativeTrustAnchors=</varname> + setting in + <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> + files.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.conf b/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.conf new file mode 100644 index 0000000000..25b09774e5 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.conf @@ -0,0 +1,27 @@ +<?xml version="1.0"?> <!--*-nxml-*--> +<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN" + "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd"> + +<!-- + This file is part of systemd. + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. +--> + +<busconfig> + + <policy user="systemd-resolve"> + <allow own="org.freedesktop.resolve1"/> + <allow send_destination="org.freedesktop.resolve1"/> + <allow receive_sender="org.freedesktop.resolve1"/> + </policy> + + <policy context="default"> + <allow send_destination="org.freedesktop.resolve1"/> + <allow receive_sender="org.freedesktop.resolve1"/> + </policy> + +</busconfig> diff --git a/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.service b/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.service new file mode 100644 index 0000000000..7ac5c323f0 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/org.freedesktop.resolve1.service @@ -0,0 +1,12 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. + +[D-BUS Service] +Name=org.freedesktop.resolve1 +Exec=/bin/false +User=root +SystemdService=dbus-org.freedesktop.resolve1.service diff --git a/src/grp-resolve/systemd-resolved/resolv.conf b/src/grp-resolve/systemd-resolved/resolv.conf new file mode 100644 index 0000000000..b8034d6829 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolv.conf @@ -0,0 +1,11 @@ +# This is a static resolv.conf file for connecting local clients to +# systemd-resolved via its DNS stub listener on 127.0.0.53. +# +# Third party programs must not access this file directly, but only through the +# symlink at /etc/resolv.conf. To manage resolv.conf(5) in a different way, +# replace this symlink by a static file or a different symlink. +# +# See systemd-resolved.service(8) for details about the supported modes of +# operation for /etc/resolv.conf. + +nameserver 127.0.0.53 diff --git a/src/grp-resolve/systemd-resolved/resolved-bus.c b/src/grp-resolve/systemd-resolved/resolved-bus.c new file mode 100644 index 0000000000..ec63fb2900 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-bus.c @@ -0,0 +1,1690 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-def.h" +#include "sd-bus/bus-common-errors.h" +#include "sd-bus/bus-util.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-bus.h" +#include "resolved-dns-synthesize.h" +#include "resolved-link-bus.h" + +static int reply_query_state(DnsQuery *q) { + + switch (q->state) { + + case DNS_TRANSACTION_NO_SERVERS: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found"); + + case DNS_TRANSACTION_TIMEOUT: + return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out"); + + case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED: + return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed"); + + case DNS_TRANSACTION_INVALID_REPLY: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply"); + + case DNS_TRANSACTION_ERRNO: + return sd_bus_reply_method_errnof(q->request, q->answer_errno, "Lookup failed due to system error: %m"); + + case DNS_TRANSACTION_ABORTED: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_ABORTED, "Query aborted"); + + case DNS_TRANSACTION_DNSSEC_FAILED: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_DNSSEC_FAILED, "DNSSEC validation failed: %s", + dnssec_result_to_string(q->answer_dnssec_result)); + + case DNS_TRANSACTION_NO_TRUST_ANCHOR: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_TRUST_ANCHOR, "No suitable trust anchor known"); + + case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_RR_TYPE_UNSUPPORTED, "Server does not support requested resource record type"); + + case DNS_TRANSACTION_NETWORK_DOWN: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NETWORK_DOWN, "Network is down"); + + case DNS_TRANSACTION_NOT_FOUND: + /* We return this as NXDOMAIN. This is only generated when a host doesn't implement LLMNR/TCP, and we + * thus quickly know that we cannot resolve an in-addr.arpa or ip6.arpa address. */ + return sd_bus_reply_method_errorf(q->request, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q)); + + case DNS_TRANSACTION_RCODE_FAILURE: { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + + if (q->answer_rcode == DNS_RCODE_NXDOMAIN) + sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q)); + else { + const char *rc, *n; + char p[DECIMAL_STR_MAX(q->answer_rcode)]; + + rc = dns_rcode_to_string(q->answer_rcode); + if (!rc) { + sprintf(p, "%i", q->answer_rcode); + rc = p; + } + + n = strjoina(_BUS_ERROR_DNS, rc); + sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", dns_query_string(q), rc); + } + + return sd_bus_reply_method_error(q->request, &error); + } + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + case DNS_TRANSACTION_SUCCESS: + default: + assert_not_reached("Impossible state"); + } +} + +static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex) { + int r; + + assert(reply); + assert(rr); + + r = sd_bus_message_open_container(reply, 'r', "iiay"); + if (r < 0) + return r; + + r = sd_bus_message_append(reply, "i", ifindex); + if (r < 0) + return r; + + if (rr->key->type == DNS_TYPE_A) { + r = sd_bus_message_append(reply, "i", AF_INET); + if (r < 0) + return r; + + r = sd_bus_message_append_array(reply, 'y', &rr->a.in_addr, sizeof(struct in_addr)); + + } else if (rr->key->type == DNS_TYPE_AAAA) { + r = sd_bus_message_append(reply, "i", AF_INET6); + if (r < 0) + return r; + + r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr)); + } else + return -EAFNOSUPPORT; + + if (r < 0) + return r; + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + return 0; +} + +static void bus_method_resolve_hostname_complete(DnsQuery *q) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + _cleanup_free_ char *normalized = NULL; + DnsResourceRecord *rr; + unsigned added = 0; + int ifindex, r; + + assert(q); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + r = reply_query_state(q); + goto finish; + } + + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + r = sd_bus_message_new_method_return(q->request, &reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + goto finish; + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + DnsQuestion *question; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = append_address(reply, rr, ifindex); + if (r < 0) + goto finish; + + if (!canonical) + canonical = dns_resource_record_ref(rr); + + added++; + } + + if (added <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + /* The key names are not necessarily normalized, make sure that they are when we return them to our bus + * clients. */ + r = dns_name_normalize(dns_resource_key_name(canonical->key), &normalized); + if (r < 0) + goto finish; + + /* Return the precise spelling and uppercasing and CNAME target reported by the server */ + assert(canonical); + r = sd_bus_message_append( + reply, "st", + normalized, + SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); + if (r < 0) + goto finish; + + r = sd_bus_send(q->manager->bus, reply, NULL); + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send hostname reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static int check_ifindex_flags(int ifindex, uint64_t *flags, uint64_t ok, sd_bus_error *error) { + assert(flags); + + if (ifindex < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index"); + + if (*flags & ~(SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_CNAME|ok)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid flags parameter"); + + if ((*flags & SD_RESOLVED_PROTOCOLS_ALL) == 0) /* If no protocol is enabled, enable all */ + *flags |= SD_RESOLVED_PROTOCOLS_ALL; + + return 0; +} + +static int parse_as_address(sd_bus_message *m, int ifindex, const char *hostname, int family, uint64_t flags) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + _cleanup_free_ char *canonical = NULL; + union in_addr_union parsed; + int r, ff, parsed_ifindex = 0; + + /* Check if the hostname is actually already an IP address formatted as string. In that case just parse it, + * let's not attempt to look it up. */ + + r = in_addr_ifindex_from_string_auto(hostname, &ff, &parsed, &parsed_ifindex); + if (r < 0) /* not an address */ + return 0; + + if (family != AF_UNSPEC && ff != family) + return sd_bus_reply_method_errorf(m, BUS_ERROR_NO_SUCH_RR, "The specified address is not of the requested family."); + if (ifindex > 0 && parsed_ifindex > 0 && parsed_ifindex != ifindex) + return sd_bus_reply_method_errorf(m, BUS_ERROR_NO_SUCH_RR, "The specified address interface index does not match requested interface."); + + if (parsed_ifindex > 0) + ifindex = parsed_ifindex; + + r = sd_bus_message_new_method_return(m, &reply); + if (r < 0) + return r; + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + return r; + + r = sd_bus_message_open_container(reply, 'r', "iiay"); + if (r < 0) + return r; + + r = sd_bus_message_append(reply, "ii", ifindex, ff); + if (r < 0) + return r; + + r = sd_bus_message_append_array(reply, 'y', &parsed, FAMILY_ADDRESS_SIZE(ff)); + if (r < 0) + return r; + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + /* When an IP address is specified we just return it as canonical name, in order to avoid a DNS + * look-up. However, we reformat it to make sure it's in a truly canonical form (i.e. on IPv6 the inner + * omissions are always done the same way). */ + r = in_addr_ifindex_to_string(ff, &parsed, ifindex, &canonical); + if (r < 0) + return r; + + r = sd_bus_message_append(reply, "st", canonical, + SD_RESOLVED_FLAGS_MAKE(dns_synthesize_protocol(flags), ff, true)); + if (r < 0) + return r; + + return sd_bus_send(sd_bus_message_get_bus(m), reply, NULL); +} + +static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dns_question_unrefp) DnsQuestion *question_idna = NULL, *question_utf8 = NULL; + Manager *m = userdata; + const char *hostname; + int family, ifindex; + uint64_t flags; + DnsQuery *q; + int r; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(message, "isit", &ifindex, &hostname, &family, &flags); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_SEARCH, error); + if (r < 0) + return r; + + r = parse_as_address(message, ifindex, hostname, family, flags); + if (r != 0) + return r; + + r = dns_name_is_valid(hostname); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid hostname '%s'", hostname); + + r = dns_question_new_address(&question_utf8, family, hostname, false); + if (r < 0) + return r; + + r = dns_question_new_address(&question_idna, family, hostname, true); + if (r < 0) + return r; + + r = dns_query_new(m, &q, question_utf8, question_idna, ifindex, flags); + if (r < 0) + return r; + + q->request = sd_bus_message_ref(message); + q->request_family = family; + q->complete = bus_method_resolve_hostname_complete; + q->suppress_unroutable_family = family == AF_UNSPEC; + + r = dns_query_bus_track(q, message); + if (r < 0) + goto fail; + + r = dns_query_go(q); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(q); + return r; +} + +static void bus_method_resolve_address_complete(DnsQuery *q) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + unsigned added = 0; + int ifindex, r; + + assert(q); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + r = reply_query_state(q); + goto finish; + } + + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + r = sd_bus_message_new_method_return(q->request, &reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "(is)"); + if (r < 0) + goto finish; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + _cleanup_free_ char *normalized = NULL; + + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = dns_name_normalize(rr->ptr.name, &normalized); + if (r < 0) + goto finish; + + r = sd_bus_message_append(reply, "(is)", ifindex, normalized); + if (r < 0) + goto finish; + + added++; + } + + if (added <= 0) { + _cleanup_free_ char *ip = NULL; + + (void) in_addr_to_string(q->request_family, &q->request_address, &ip); + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, + "Address '%s' does not have any RR of requested type", strnull(ip)); + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); + if (r < 0) + goto finish; + + r = sd_bus_send(q->manager->bus, reply, NULL); + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send address reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static int bus_method_resolve_address(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + Manager *m = userdata; + int family, ifindex; + uint64_t flags; + const void *d; + DnsQuery *q; + size_t sz; + int r; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(message, "ii", &ifindex, &family); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + r = sd_bus_message_read_array(message, 'y', &d, &sz); + if (r < 0) + return r; + + if (sz != FAMILY_ADDRESS_SIZE(family)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size"); + + r = sd_bus_message_read(message, "t", &flags); + if (r < 0) + return r; + + r = check_ifindex_flags(ifindex, &flags, 0, error); + if (r < 0) + return r; + + r = dns_question_new_reverse(&question, family, d); + if (r < 0) + return r; + + r = dns_query_new(m, &q, question, question, ifindex, flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + q->request = sd_bus_message_ref(message); + q->request_family = family; + memcpy(&q->request_address, d, sz); + q->complete = bus_method_resolve_address_complete; + + r = dns_query_bus_track(q, message); + if (r < 0) + goto fail; + + r = dns_query_go(q); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(q); + return r; +} + +static int bus_message_append_rr(sd_bus_message *m, DnsResourceRecord *rr, int ifindex) { + int r; + + assert(m); + assert(rr); + + r = sd_bus_message_open_container(m, 'r', "iqqay"); + if (r < 0) + return r; + + r = sd_bus_message_append(m, "iqq", + ifindex, + rr->key->class, + rr->key->type); + if (r < 0) + return r; + + r = dns_resource_record_to_wire_format(rr, false); + if (r < 0) + return r; + + r = sd_bus_message_append_array(m, 'y', rr->wire_format, rr->wire_format_size); + if (r < 0) + return r; + + return sd_bus_message_close_container(m); +} + +static void bus_method_resolve_record_complete(DnsQuery *q) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + DnsResourceRecord *rr; + DnsQuestion *question; + unsigned added = 0; + int ifindex; + int r; + + assert(q); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + r = reply_query_state(q); + goto finish; + } + + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + r = sd_bus_message_new_method_return(q->request, &reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "(iqqay)"); + if (r < 0) + goto finish; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = bus_message_append_rr(reply, rr, ifindex); + if (r < 0) + goto finish; + + added++; + } + + if (added <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); + if (r < 0) + goto finish; + + r = sd_bus_send(q->manager->bus, reply, NULL); + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send record reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static int bus_method_resolve_record(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + Manager *m = userdata; + uint16_t class, type; + const char *name; + int r, ifindex; + uint64_t flags; + DnsQuery *q; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(message, "isqqt", &ifindex, &name, &class, &type, &flags); + if (r < 0) + return r; + + r = dns_name_is_valid(name); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid name '%s'", name); + + if (!dns_type_is_valid_query(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Specified resource record type %" PRIu16 " may not be used in a query.", type); + if (dns_type_is_zone_transer(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Zone transfers not permitted via this programming interface."); + if (dns_type_is_obsolete(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Specified DNS resource record type %" PRIu16 " is obsolete.", type); + + r = check_ifindex_flags(ifindex, &flags, 0, error); + if (r < 0) + return r; + + question = dns_question_new(1); + if (!question) + return -ENOMEM; + + key = dns_resource_key_new(class, type, name); + if (!key) + return -ENOMEM; + + r = dns_question_add(question, key); + if (r < 0) + return r; + + r = dns_query_new(m, &q, question, question, ifindex, flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + /* Let's request that the TTL is fixed up for locally cached entries, after all we return it in the wire format + * blob */ + q->clamp_ttl = true; + + q->request = sd_bus_message_ref(message); + q->complete = bus_method_resolve_record_complete; + + r = dns_query_bus_track(q, message); + if (r < 0) + goto fail; + + r = dns_query_go(q); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(q); + return r; +} + +static int append_srv(DnsQuery *q, sd_bus_message *reply, DnsResourceRecord *rr) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + _cleanup_free_ char *normalized = NULL; + DnsQuery *aux; + int r; + + assert(q); + assert(reply); + assert(rr); + assert(rr->key); + + if (rr->key->type != DNS_TYPE_SRV) + return 0; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + /* First, let's see if we could find an appropriate A or AAAA + * record for the SRV record */ + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + DnsResourceRecord *zz; + DnsQuestion *question; + + if (aux->state != DNS_TRANSACTION_SUCCESS) + continue; + if (aux->auxiliary_result != 0) + continue; + + question = dns_query_question_for_protocol(aux, aux->answer_protocol); + + r = dns_name_equal(dns_question_first_name(question), rr->srv.name); + if (r < 0) + return r; + if (r == 0) + continue; + + DNS_ANSWER_FOREACH(zz, aux->answer) { + + r = dns_question_matches_rr(question, zz, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + canonical = dns_resource_record_ref(zz); + break; + } + + if (canonical) + break; + } + + /* Is there are successful A/AAAA lookup for this SRV RR? If not, don't add it */ + if (!canonical) + return 0; + } + + r = sd_bus_message_open_container(reply, 'r', "qqqsa(iiay)s"); + if (r < 0) + return r; + + r = dns_name_normalize(rr->srv.name, &normalized); + if (r < 0) + return r; + + r = sd_bus_message_append( + reply, + "qqqs", + rr->srv.priority, rr->srv.weight, rr->srv.port, normalized); + if (r < 0) + return r; + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + return r; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + DnsResourceRecord *zz; + DnsQuestion *question; + int ifindex; + + if (aux->state != DNS_TRANSACTION_SUCCESS) + continue; + if (aux->auxiliary_result != 0) + continue; + + question = dns_query_question_for_protocol(aux, aux->answer_protocol); + + r = dns_name_equal(dns_question_first_name(question), rr->srv.name); + if (r < 0) + return r; + if (r == 0) + continue; + + DNS_ANSWER_FOREACH_IFINDEX(zz, ifindex, aux->answer) { + + r = dns_question_matches_rr(question, zz, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + r = append_address(reply, zz, ifindex); + if (r < 0) + return r; + } + } + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + if (canonical) { + normalized = mfree(normalized); + + r = dns_name_normalize(dns_resource_key_name(canonical->key), &normalized); + if (r < 0) + return r; + } + + /* Note that above we appended the hostname as encoded in the + * SRV, and here the canonical hostname this maps to. */ + r = sd_bus_message_append(reply, "s", normalized); + if (r < 0) + return r; + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + return 1; +} + +static int append_txt(sd_bus_message *reply, DnsResourceRecord *rr) { + DnsTxtItem *i; + int r; + + assert(reply); + assert(rr); + assert(rr->key); + + if (rr->key->type != DNS_TYPE_TXT) + return 0; + + LIST_FOREACH(items, i, rr->txt.items) { + + if (i->length <= 0) + continue; + + r = sd_bus_message_append_array(reply, 'y', i->data, i->length); + if (r < 0) + return r; + } + + return 1; +} + +static void resolve_service_all_complete(DnsQuery *q) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + unsigned added = 0; + DnsQuery *aux; + int r; + + assert(q); + + if (q->block_all_complete > 0) + return; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + DnsQuery *bad = NULL; + bool have_success = false; + + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + + switch (aux->state) { + + case DNS_TRANSACTION_PENDING: + /* If an auxiliary query is still pending, let's wait */ + return; + + case DNS_TRANSACTION_SUCCESS: + if (aux->auxiliary_result == 0) + have_success = true; + else + bad = aux; + break; + + default: + bad = aux; + break; + } + } + + if (!have_success) { + /* We can only return one error, hence pick the last error we encountered */ + + assert(bad); + + if (bad->state == DNS_TRANSACTION_SUCCESS) { + assert(bad->auxiliary_result != 0); + + if (bad->auxiliary_result == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(bad)); + goto finish; + } + + r = bad->auxiliary_result; + goto finish; + } + + r = reply_query_state(bad); + goto finish; + } + } + + r = sd_bus_message_new_method_return(q->request, &reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "(qqqsa(iiay)s)"); + if (r < 0) + goto finish; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = append_srv(q, reply, rr); + if (r < 0) + goto finish; + if (r == 0) /* not an SRV record */ + continue; + + if (!canonical) + canonical = dns_resource_record_ref(rr); + + added++; + } + + if (added <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "ay"); + if (r < 0) + goto finish; + + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = append_txt(reply, rr); + if (r < 0) + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + assert(canonical); + r = dns_service_split(dns_resource_key_name(canonical->key), &name, &type, &domain); + if (r < 0) + goto finish; + + r = sd_bus_message_append( + reply, + "ssst", + name, type, domain, + SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); + if (r < 0) + goto finish; + + r = sd_bus_send(q->manager->bus, reply, NULL); + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send service reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static void resolve_service_hostname_complete(DnsQuery *q) { + int r; + + assert(q); + assert(q->auxiliary_for); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + resolve_service_all_complete(q->auxiliary_for); + return; + } + + r = dns_query_process_cname(q); + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + /* This auxiliary lookup is finished or failed, let's see if all are finished now. */ + q->auxiliary_result = r; + resolve_service_all_complete(q->auxiliary_for); +} + +static int resolve_service_hostname(DnsQuery *q, DnsResourceRecord *rr, int ifindex) { + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + DnsQuery *aux; + int r; + + assert(q); + assert(rr); + assert(rr->key); + assert(rr->key->type == DNS_TYPE_SRV); + + /* OK, we found an SRV record for the service. Let's resolve + * the hostname included in it */ + + r = dns_question_new_address(&question, q->request_family, rr->srv.name, false); + if (r < 0) + return r; + + r = dns_query_new(q->manager, &aux, question, question, ifindex, q->flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + aux->request_family = q->request_family; + aux->complete = resolve_service_hostname_complete; + + r = dns_query_make_auxiliary(aux, q); + if (r == -EAGAIN) { + /* Too many auxiliary lookups? If so, don't complain, + * let's just not add this one, we already have more + * than enough */ + + dns_query_free(aux); + return 0; + } + if (r < 0) + goto fail; + + /* Note that auxiliary queries do not track the original bus + * client, only the primary request does that. */ + + r = dns_query_go(aux); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(aux); + return r; +} + +static void bus_method_resolve_service_complete(DnsQuery *q) { + bool has_root_domain = false; + DnsResourceRecord *rr; + DnsQuestion *question; + unsigned found = 0; + int ifindex, r; + + assert(q); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + r = reply_query_state(q); + goto finish; + } + + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + if (rr->key->type != DNS_TYPE_SRV) + continue; + + if (dns_name_is_root(rr->srv.name)) { + has_root_domain = true; + continue; + } + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + q->block_all_complete++; + r = resolve_service_hostname(q, rr, ifindex); + q->block_all_complete--; + + if (r < 0) + goto finish; + } + + found++; + } + + if (has_root_domain && found <= 0) { + /* If there's exactly one SRV RR and it uses + * the root domain as host name, then the + * service is explicitly not offered on the + * domain. Report this as a recognizable + * error. See RFC 2782, Section "Usage + * Rules". */ + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_SERVICE, "'%s' does not provide the requested service", dns_query_string(q)); + goto finish; + } + + if (found <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + /* Maybe we are already finished? check now... */ + resolve_service_all_complete(q); + return; + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send service reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static int bus_method_resolve_service(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dns_question_unrefp) DnsQuestion *question_idna = NULL, *question_utf8 = NULL; + const char *name, *type, *domain; + Manager *m = userdata; + int family, ifindex; + uint64_t flags; + DnsQuery *q; + int r; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(message, "isssit", &ifindex, &name, &type, &domain, &family, &flags); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + if (isempty(name)) + name = NULL; + else if (!dns_service_name_is_valid(name)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid service name '%s'", name); + + if (isempty(type)) + type = NULL; + else if (!dns_srv_type_is_valid(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid SRV service type '%s'", type); + + r = dns_name_is_valid(domain); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid domain '%s'", domain); + + if (name && !type) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Service name cannot be specified without service type."); + + r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_TXT|SD_RESOLVED_NO_ADDRESS, error); + if (r < 0) + return r; + + r = dns_question_new_service(&question_utf8, name, type, domain, !(flags & SD_RESOLVED_NO_TXT), false); + if (r < 0) + return r; + + r = dns_question_new_service(&question_idna, name, type, domain, !(flags & SD_RESOLVED_NO_TXT), true); + if (r < 0) + return r; + + r = dns_query_new(m, &q, question_utf8, question_idna, ifindex, flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + q->request = sd_bus_message_ref(message); + q->request_family = family; + q->complete = bus_method_resolve_service_complete; + + r = dns_query_bus_track(q, message); + if (r < 0) + goto fail; + + r = dns_query_go(q); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(q); + return r; +} + +int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex) { + int r; + + assert(reply); + assert(s); + + r = sd_bus_message_open_container(reply, 'r', with_ifindex ? "iiay" : "iay"); + if (r < 0) + return r; + + if (with_ifindex) { + r = sd_bus_message_append(reply, "i", dns_server_ifindex(s)); + if (r < 0) + return r; + } + + r = sd_bus_message_append(reply, "i", s->family); + if (r < 0) + return r; + + r = sd_bus_message_append_array(reply, 'y', &s->address, FAMILY_ADDRESS_SIZE(s->family)); + if (r < 0) + return r; + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_dns_servers( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + unsigned c = 0; + DnsServer *s; + Iterator i; + Link *l; + int r; + + assert(reply); + assert(m); + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + return r; + + LIST_FOREACH(servers, s, m->dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + + c++; + } + + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(servers, s, l->dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + c++; + } + } + + if (c == 0) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + } + } + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_domains( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + DnsSearchDomain *d; + Iterator i; + Link *l; + int r; + + assert(reply); + assert(m); + + r = sd_bus_message_open_container(reply, 'a', "(isb)"); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, m->search_domains) { + r = sd_bus_message_append(reply, "(isb)", 0, d->name, d->route_only); + if (r < 0) + return r; + } + + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(domains, d, l->search_domains) { + r = sd_bus_message_append(reply, "(isb)", l->ifindex, d->name, d->route_only); + if (r < 0) + return r; + } + } + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_transaction_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "(tt)", + (uint64_t) hashmap_size(m->dns_transactions), + (uint64_t) m->n_transactions_total); +} + +static int bus_property_get_cache_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + uint64_t size = 0, hit = 0, miss = 0; + Manager *m = userdata; + DnsScope *s; + + assert(reply); + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) { + size += dns_cache_size(&s->cache); + hit += s->cache.n_hit; + miss += s->cache.n_miss; + } + + return sd_bus_message_append(reply, "(ttt)", size, hit, miss); +} + +static int bus_property_get_dnssec_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "(tttt)", + (uint64_t) m->n_dnssec_verdict[DNSSEC_SECURE], + (uint64_t) m->n_dnssec_verdict[DNSSEC_INSECURE], + (uint64_t) m->n_dnssec_verdict[DNSSEC_BOGUS], + (uint64_t) m->n_dnssec_verdict[DNSSEC_INDETERMINATE]); +} + +static int bus_property_get_dnssec_supported( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "b", manager_dnssec_supported(m)); +} + +static int bus_property_get_ntas( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + const char *domain; + Iterator i; + int r; + + assert(reply); + assert(m); + + r = sd_bus_message_open_container(reply, 'a', "s"); + if (r < 0) + return r; + + SET_FOREACH(domain, m->trust_anchor.negative_by_name, i) { + r = sd_bus_message_append(reply, "s", domain); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int bus_method_reset_statistics(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + DnsScope *s; + + assert(message); + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) + s->cache.n_hit = s->cache.n_miss = 0; + + m->n_transactions_total = 0; + zero(m->n_dnssec_verdict); + + return sd_bus_reply_method_return(message, NULL); +} + +static int get_any_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) { + Link *l; + + assert(m); + assert(ret); + + if (ifindex <= 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index"); + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) + return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_LINK, "Link %i not known", ifindex); + + *ret = l; + return 0; +} + +static int call_link_method(Manager *m, sd_bus_message *message, sd_bus_message_handler_t handler, sd_bus_error *error) { + int ifindex, r; + Link *l; + + assert(m); + assert(message); + assert(handler); + + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "i", &ifindex); + if (r < 0) + return r; + + r = get_any_link(m, ifindex, &l, error); + if (r < 0) + return r; + + return handler(message, l, error); +} + +static int bus_method_set_link_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dns_servers, error); +} + +static int bus_method_set_link_domains(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_domains, error); +} + +static int bus_method_set_link_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_llmnr, error); +} + +static int bus_method_set_link_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_mdns, error); +} + +static int bus_method_set_link_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dnssec, error); +} + +static int bus_method_set_link_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dnssec_negative_trust_anchors, error); +} + +static int bus_method_revert_link(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_revert, error); +} + +static int bus_method_get_link(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_free_ char *p = NULL; + Manager *m = userdata; + int r, ifindex; + Link *l; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "i", &ifindex); + if (r < 0) + return r; + + r = get_any_link(m, ifindex, &l, error); + if (r < 0) + return r; + + p = link_bus_path(l); + if (!p) + return -ENOMEM; + + return sd_bus_reply_method_return(message, "o", p); +} + +static int bus_method_flush_caches(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + + assert(message); + assert(m); + + manager_flush_caches(m); + + return sd_bus_reply_method_return(message, NULL); +} + +static const sd_bus_vtable resolve_vtable[] = { + SD_BUS_VTABLE_START(0), + SD_BUS_PROPERTY("LLMNRHostname", "s", NULL, offsetof(Manager, llmnr_hostname), 0), + SD_BUS_PROPERTY("DNS", "a(iiay)", bus_property_get_dns_servers, 0, 0), + SD_BUS_PROPERTY("Domains", "a(isb)", bus_property_get_domains, 0, 0), + SD_BUS_PROPERTY("TransactionStatistics", "(tt)", bus_property_get_transaction_statistics, 0, 0), + SD_BUS_PROPERTY("CacheStatistics", "(ttt)", bus_property_get_cache_statistics, 0, 0), + SD_BUS_PROPERTY("DNSSECStatistics", "(tttt)", bus_property_get_dnssec_statistics, 0, 0), + SD_BUS_PROPERTY("DNSSECSupported", "b", bus_property_get_dnssec_supported, 0, 0), + SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", bus_property_get_ntas, 0, 0), + + SD_BUS_METHOD("ResolveHostname", "isit", "a(iiay)st", bus_method_resolve_hostname, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResolveAddress", "iiayt", "a(is)t", bus_method_resolve_address, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResolveRecord", "isqqt", "a(iqqay)t", bus_method_resolve_record, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResolveService", "isssit", "a(qqqsa(iiay)s)aayssst", bus_method_resolve_service, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResetStatistics", NULL, NULL, bus_method_reset_statistics, 0), + SD_BUS_METHOD("FlushCaches", NULL, NULL, bus_method_flush_caches, 0), + SD_BUS_METHOD("GetLink", "i", "o", bus_method_get_link, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("SetLinkDNS", "ia(iay)", NULL, bus_method_set_link_dns_servers, 0), + SD_BUS_METHOD("SetLinkDomains", "ia(sb)", NULL, bus_method_set_link_domains, 0), + SD_BUS_METHOD("SetLinkLLMNR", "is", NULL, bus_method_set_link_llmnr, 0), + SD_BUS_METHOD("SetLinkMulticastDNS", "is", NULL, bus_method_set_link_mdns, 0), + SD_BUS_METHOD("SetLinkDNSSEC", "is", NULL, bus_method_set_link_dnssec, 0), + SD_BUS_METHOD("SetLinkDNSSECNegativeTrustAnchors", "ias", NULL, bus_method_set_link_dnssec_negative_trust_anchors, 0), + SD_BUS_METHOD("RevertLink", "i", NULL, bus_method_revert_link, 0), + + SD_BUS_VTABLE_END, +}; + +static int on_bus_retry(sd_event_source *s, usec_t usec, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(m); + + m->bus_retry_event_source = sd_event_source_unref(m->bus_retry_event_source); + + manager_connect_bus(m); + return 0; +} + +static int match_prepare_for_sleep(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) { + Manager *m = userdata; + int b, r; + + assert(message); + assert(m); + + r = sd_bus_message_read(message, "b", &b); + if (r < 0) { + log_debug_errno(r, "Failed to parse PrepareForSleep signal: %m"); + return 0; + } + + if (b) + return 0; + + log_debug("Coming back from suspend, verifying all RRs..."); + + manager_verify_all(m); + return 0; +} + +int manager_connect_bus(Manager *m) { + int r; + + assert(m); + + if (m->bus) + return 0; + + r = sd_bus_default_system(&m->bus); + if (r < 0) { + /* We failed to connect? Yuck, we must be in early + * boot. Let's try in 5s again. As soon as we have + * kdbus we can stop doing this... */ + + log_debug_errno(r, "Failed to connect to bus, trying again in 5s: %m"); + + r = sd_event_add_time(m->event, &m->bus_retry_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + 5*USEC_PER_SEC, 0, on_bus_retry, m); + if (r < 0) + return log_error_errno(r, "Failed to install bus reconnect time event: %m"); + + (void) sd_event_source_set_description(m->bus_retry_event_source, "bus-retry"); + return 0; + } + + r = sd_bus_add_object_vtable(m->bus, NULL, "/org/freedesktop/resolve1", "org.freedesktop.resolve1.Manager", resolve_vtable, m); + if (r < 0) + return log_error_errno(r, "Failed to register object: %m"); + + r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/resolve1/link", "org.freedesktop.resolve1.Link", link_vtable, link_object_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register link objects: %m"); + + r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/resolve1/link", link_node_enumerator, m); + if (r < 0) + return log_error_errno(r, "Failed to register link enumerator: %m"); + + r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0); + if (r < 0) + return log_error_errno(r, "Failed to register name: %m"); + + r = sd_bus_attach_event(m->bus, m->event, 0); + if (r < 0) + return log_error_errno(r, "Failed to attach bus to event loop: %m"); + + r = sd_bus_add_match(m->bus, &m->prepare_for_sleep_slot, + "type='signal'," + "sender='org.freedesktop.login1'," + "interface='org.freedesktop.login1.Manager'," + "member='PrepareForSleep'," + "path='/org/freedesktop/login1'", + match_prepare_for_sleep, + m); + if (r < 0) + log_error_errno(r, "Failed to add match for PrepareForSleep: %m"); + + return 0; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-bus.h b/src/grp-resolve/systemd-resolved/resolved-bus.h new file mode 100644 index 0000000000..f49e1337d2 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-bus.h @@ -0,0 +1,25 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +int manager_connect_bus(Manager *m); +int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex); diff --git a/src/grp-resolve/systemd-resolved/resolved-conf.c b/src/grp-resolve/systemd-resolved/resolved-conf.c new file mode 100644 index 0000000000..48aa2da331 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-conf.c @@ -0,0 +1,252 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/def.h" +#include "systemd-basic/extract-word.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" +#include "systemd-shared/conf-parser.h" + +#include "resolved-conf.h" + +DEFINE_CONFIG_PARSE_ENUM(config_parse_dns_stub_listener_mode, dns_stub_listener_mode, DnsStubListenerMode, "Failed to parse DNS stub listener mode setting"); + +static const char* const dns_stub_listener_mode_table[_DNS_STUB_LISTENER_MODE_MAX] = { + [DNS_STUB_LISTENER_NO] = "no", + [DNS_STUB_LISTENER_UDP] = "udp", + [DNS_STUB_LISTENER_TCP] = "tcp", + [DNS_STUB_LISTENER_YES] = "yes", +}; +DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(dns_stub_listener_mode, DnsStubListenerMode, DNS_STUB_LISTENER_YES); + +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word) { + union in_addr_union address; + int family, r, ifindex = 0; + DnsServer *s; + + assert(m); + assert(word); + + r = in_addr_ifindex_from_string_auto(word, &family, &address, &ifindex); + if (r < 0) + return r; + + /* Silently filter out 0.0.0.0 and 127.0.0.53 (our own stub DNS listener) */ + if (!dns_server_address_valid(family, &address)) + return 0; + + /* Filter out duplicates */ + s = dns_server_find(manager_get_first_dns_server(m, type), family, &address, ifindex); + if (s) { + /* + * Drop the marker. This is used to find the servers + * that ceased to exist, see + * manager_mark_dns_servers() and + * manager_flush_marked_dns_servers(). + */ + dns_server_move_back_and_unmark(s); + return 0; + } + + return dns_server_new(m, NULL, type, NULL, family, &address, ifindex); +} + +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string) { + int r; + + assert(m); + assert(string); + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&string, &word, NULL, 0); + if (r < 0) + return r; + if (r == 0) + break; + + r = manager_add_dns_server_by_string(m, type, word); + if (r < 0) + log_warning_errno(r, "Failed to add DNS server address '%s', ignoring: %m", word); + } + + return 0; +} + +int manager_add_search_domain_by_string(Manager *m, const char *domain) { + DnsSearchDomain *d; + bool route_only; + int r; + + assert(m); + assert(domain); + + route_only = *domain == '~'; + if (route_only) + domain++; + + if (dns_name_is_root(domain) || streq(domain, "*")) { + route_only = true; + domain = "."; + } + + r = dns_search_domain_find(m->search_domains, domain, &d); + if (r < 0) + return r; + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(m, &d, DNS_SEARCH_DOMAIN_SYSTEM, NULL, domain); + if (r < 0) + return r; + } + + d->route_only = route_only; + return 0; +} + +int manager_parse_search_domains_and_warn(Manager *m, const char *string) { + int r; + + assert(m); + assert(string); + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&string, &word, NULL, EXTRACT_QUOTES); + if (r < 0) + return r; + if (r == 0) + break; + + r = manager_add_search_domain_by_string(m, word); + if (r < 0) + log_warning_errno(r, "Failed to add search domain '%s', ignoring: %m", word); + } + + return 0; +} + +int config_parse_dns_servers( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Manager *m = userdata; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(m); + + if (isempty(rvalue)) + /* Empty assignment means clear the list */ + dns_server_unlink_all(manager_get_first_dns_server(m, ltype)); + else { + /* Otherwise, add to the list */ + r = manager_parse_dns_server_string_and_warn(m, ltype, rvalue); + if (r < 0) { + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue); + return 0; + } + } + + /* If we have a manual setting, then we stop reading + * /etc/resolv.conf */ + if (ltype == DNS_SERVER_SYSTEM) + m->read_resolv_conf = false; + if (ltype == DNS_SERVER_FALLBACK) + m->need_builtin_fallbacks = false; + + return 0; +} + +int config_parse_search_domains( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + Manager *m = userdata; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(m); + + if (isempty(rvalue)) + /* Empty assignment means clear the list */ + dns_search_domain_unlink_all(m->search_domains); + else { + /* Otherwise, add to the list */ + r = manager_parse_search_domains_and_warn(m, rvalue); + if (r < 0) { + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse search domains string '%s'. Ignoring.", rvalue); + return 0; + } + } + + /* If we have a manual setting, then we stop reading + * /etc/resolv.conf */ + m->read_resolv_conf = false; + + return 0; +} + +int manager_parse_config_file(Manager *m) { + int r; + + assert(m); + + r = config_parse_many_nulstr(PKGSYSCONFDIR "/resolved.conf", + CONF_PATHS_NULSTR("systemd/resolved.conf.d"), + "Resolve\0", + config_item_perf_lookup, resolved_gperf_lookup, + false, m); + if (r < 0) + return r; + + if (m->need_builtin_fallbacks) { + r = manager_parse_dns_server_string_and_warn(m, DNS_SERVER_FALLBACK, DNS_SERVERS); + if (r < 0) + return r; + } + + return 0; + +} diff --git a/src/grp-resolve/systemd-resolved/resolved-conf.h b/src/grp-resolve/systemd-resolved/resolved-conf.h new file mode 100644 index 0000000000..e8cd8e1af3 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-conf.h @@ -0,0 +1,51 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +typedef enum DnsStubListenerMode DnsStubListenerMode; + +enum DnsStubListenerMode { + DNS_STUB_LISTENER_NO, + DNS_STUB_LISTENER_UDP, + DNS_STUB_LISTENER_TCP, + DNS_STUB_LISTENER_YES, + _DNS_STUB_LISTENER_MODE_MAX, + _DNS_STUB_LISTENER_MODE_INVALID = -1 +}; + +#include "resolved-dns-server.h" +#include "resolved-manager.h" + +int manager_parse_config_file(Manager *m); + +int manager_add_search_domain_by_string(Manager *m, const char *domain); +int manager_parse_search_domains_and_warn(Manager *m, const char *string); + +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word); +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string); + +const struct ConfigPerfItem* resolved_gperf_lookup(const char *key, GPERF_LEN_TYPE length); + +int config_parse_dns_servers(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_search_domains(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_dns_stub_listener_mode(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); + +const char* dns_stub_listener_mode_to_string(DnsStubListenerMode p) _const_; +DnsStubListenerMode dns_stub_listener_mode_from_string(const char *s) _pure_; diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-cache.c b/src/grp-resolve/systemd-resolved/resolved-dns-cache.c new file mode 100644 index 0000000000..1f8811c5de --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-cache.c @@ -0,0 +1,1065 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <net/if.h> + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-cache.h" + +/* Never cache more than 4K entries. RFC 1536, Section 5 suggests to + * leave DNS caches unbounded, but that's crazy. */ +#define CACHE_MAX 4096 + +/* We never keep any item longer than 2h in our cache */ +#define CACHE_TTL_MAX_USEC (2 * USEC_PER_HOUR) + +typedef enum DnsCacheItemType DnsCacheItemType; +typedef struct DnsCacheItem DnsCacheItem; + +enum DnsCacheItemType { + DNS_CACHE_POSITIVE, + DNS_CACHE_NODATA, + DNS_CACHE_NXDOMAIN, +}; + +struct DnsCacheItem { + DnsCacheItemType type; + DnsResourceKey *key; + DnsResourceRecord *rr; + + usec_t until; + bool authenticated:1; + bool shared_owner:1; + + int ifindex; + int owner_family; + union in_addr_union owner_address; + + unsigned prioq_idx; + LIST_FIELDS(DnsCacheItem, by_key); +}; + +static void dns_cache_item_free(DnsCacheItem *i) { + if (!i) + return; + + dns_resource_record_unref(i->rr); + dns_resource_key_unref(i->key); + free(i); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsCacheItem*, dns_cache_item_free); + +static void dns_cache_item_unlink_and_free(DnsCache *c, DnsCacheItem *i) { + DnsCacheItem *first; + + assert(c); + + if (!i) + return; + + first = hashmap_get(c->by_key, i->key); + LIST_REMOVE(by_key, first, i); + + if (first) + assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); + else + hashmap_remove(c->by_key, i->key); + + prioq_remove(c->by_expiry, i, &i->prioq_idx); + + dns_cache_item_free(i); +} + +static bool dns_cache_remove_by_rr(DnsCache *c, DnsResourceRecord *rr) { + DnsCacheItem *first, *i; + int r; + + first = hashmap_get(c->by_key, rr->key); + LIST_FOREACH(by_key, i, first) { + r = dns_resource_record_equal(i->rr, rr); + if (r < 0) + return r; + if (r > 0) { + dns_cache_item_unlink_and_free(c, i); + return true; + } + } + + return false; +} + +static bool dns_cache_remove_by_key(DnsCache *c, DnsResourceKey *key) { + DnsCacheItem *first, *i, *n; + + assert(c); + assert(key); + + first = hashmap_remove(c->by_key, key); + if (!first) + return false; + + LIST_FOREACH_SAFE(by_key, i, n, first) { + prioq_remove(c->by_expiry, i, &i->prioq_idx); + dns_cache_item_free(i); + } + + return true; +} + +void dns_cache_flush(DnsCache *c) { + DnsResourceKey *key; + + assert(c); + + while ((key = hashmap_first_key(c->by_key))) + dns_cache_remove_by_key(c, key); + + assert(hashmap_size(c->by_key) == 0); + assert(prioq_size(c->by_expiry) == 0); + + c->by_key = hashmap_free(c->by_key); + c->by_expiry = prioq_free(c->by_expiry); +} + +static void dns_cache_make_space(DnsCache *c, unsigned add) { + assert(c); + + if (add <= 0) + return; + + /* Makes space for n new entries. Note that we actually allow + * the cache to grow beyond CACHE_MAX, but only when we shall + * add more RRs to the cache than CACHE_MAX at once. In that + * case the cache will be emptied completely otherwise. */ + + for (;;) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + DnsCacheItem *i; + + if (prioq_size(c->by_expiry) <= 0) + break; + + if (prioq_size(c->by_expiry) + add < CACHE_MAX) + break; + + i = prioq_peek(c->by_expiry); + assert(i); + + /* Take an extra reference to the key so that it + * doesn't go away in the middle of the remove call */ + key = dns_resource_key_ref(i->key); + dns_cache_remove_by_key(c, key); + } +} + +void dns_cache_prune(DnsCache *c) { + usec_t t = 0; + + assert(c); + + /* Remove all entries that are past their TTL */ + + for (;;) { + DnsCacheItem *i; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + i = prioq_peek(c->by_expiry); + if (!i) + break; + + if (t <= 0) + t = now(clock_boottime_or_monotonic()); + + if (i->until > t) + break; + + /* Depending whether this is an mDNS shared entry + * either remove only this one RR or the whole RRset */ + log_debug("Removing %scache entry for %s (expired "USEC_FMT"s ago)", + i->shared_owner ? "shared " : "", + dns_resource_key_to_string(i->key, key_str, sizeof key_str), + (t - i->until) / USEC_PER_SEC); + + if (i->shared_owner) + dns_cache_item_unlink_and_free(c, i); + else { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + /* Take an extra reference to the key so that it + * doesn't go away in the middle of the remove call */ + key = dns_resource_key_ref(i->key); + dns_cache_remove_by_key(c, key); + } + } +} + +static int dns_cache_item_prioq_compare_func(const void *a, const void *b) { + const DnsCacheItem *x = a, *y = b; + + if (x->until < y->until) + return -1; + if (x->until > y->until) + return 1; + return 0; +} + +static int dns_cache_init(DnsCache *c) { + int r; + + assert(c); + + r = prioq_ensure_allocated(&c->by_expiry, dns_cache_item_prioq_compare_func); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&c->by_key, &dns_resource_key_hash_ops); + if (r < 0) + return r; + + return r; +} + +static int dns_cache_link_item(DnsCache *c, DnsCacheItem *i) { + DnsCacheItem *first; + int r; + + assert(c); + assert(i); + + r = prioq_put(c->by_expiry, i, &i->prioq_idx); + if (r < 0) + return r; + + first = hashmap_get(c->by_key, i->key); + if (first) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; + + /* Keep a reference to the original key, while we manipulate the list. */ + k = dns_resource_key_ref(first->key); + + /* Now, try to reduce the number of keys we keep */ + dns_resource_key_reduce(&first->key, &i->key); + + if (first->rr) + dns_resource_key_reduce(&first->rr->key, &i->key); + if (i->rr) + dns_resource_key_reduce(&i->rr->key, &i->key); + + LIST_PREPEND(by_key, first, i); + assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); + } else { + r = hashmap_put(c->by_key, i->key, i); + if (r < 0) { + prioq_remove(c->by_expiry, i, &i->prioq_idx); + return r; + } + } + + return 0; +} + +static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) { + DnsCacheItem *i; + + assert(c); + assert(rr); + + LIST_FOREACH(by_key, i, hashmap_get(c->by_key, rr->key)) + if (i->rr && dns_resource_record_equal(i->rr, rr) > 0) + return i; + + return NULL; +} + +static usec_t calculate_until(DnsResourceRecord *rr, uint32_t nsec_ttl, usec_t timestamp, bool use_soa_minimum) { + uint32_t ttl; + usec_t u; + + assert(rr); + + ttl = MIN(rr->ttl, nsec_ttl); + if (rr->key->type == DNS_TYPE_SOA && use_soa_minimum) { + /* If this is a SOA RR, and it is requested, clamp to + * the SOA's minimum field. This is used when we do + * negative caching, to determine the TTL for the + * negative caching entry. See RFC 2308, Section + * 5. */ + + if (ttl > rr->soa.minimum) + ttl = rr->soa.minimum; + } + + u = ttl * USEC_PER_SEC; + if (u > CACHE_TTL_MAX_USEC) + u = CACHE_TTL_MAX_USEC; + + if (rr->expiry != USEC_INFINITY) { + usec_t left; + + /* Make use of the DNSSEC RRSIG expiry info, if we + * have it */ + + left = LESS_BY(rr->expiry, now(CLOCK_REALTIME)); + if (u > left) + u = left; + } + + return timestamp + u; +} + +static void dns_cache_item_update_positive( + DnsCache *c, + DnsCacheItem *i, + DnsResourceRecord *rr, + bool authenticated, + bool shared_owner, + usec_t timestamp, + int ifindex, + int owner_family, + const union in_addr_union *owner_address) { + + assert(c); + assert(i); + assert(rr); + assert(owner_address); + + i->type = DNS_CACHE_POSITIVE; + + if (!i->by_key_prev) + /* We are the first item in the list, we need to + * update the key used in the hashmap */ + + assert_se(hashmap_replace(c->by_key, rr->key, i) >= 0); + + dns_resource_record_ref(rr); + dns_resource_record_unref(i->rr); + i->rr = rr; + + dns_resource_key_unref(i->key); + i->key = dns_resource_key_ref(rr->key); + + i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); + i->authenticated = authenticated; + i->shared_owner = shared_owner; + + i->ifindex = ifindex; + + i->owner_family = owner_family; + i->owner_address = *owner_address; + + prioq_reshuffle(c->by_expiry, i, &i->prioq_idx); +} + +static int dns_cache_put_positive( + DnsCache *c, + DnsResourceRecord *rr, + bool authenticated, + bool shared_owner, + usec_t timestamp, + int ifindex, + int owner_family, + const union in_addr_union *owner_address) { + + _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; + DnsCacheItem *existing; + char key_str[DNS_RESOURCE_KEY_STRING_MAX], ifname[IF_NAMESIZE]; + int r, k; + + assert(c); + assert(rr); + assert(owner_address); + + /* Never cache pseudo RRs */ + if (dns_class_is_pseudo(rr->key->class)) + return 0; + if (dns_type_is_pseudo(rr->key->type)) + return 0; + + /* New TTL is 0? Delete this specific entry... */ + if (rr->ttl <= 0) { + k = dns_cache_remove_by_rr(c, rr); + log_debug("%s: %s", + k > 0 ? "Removed zero TTL entry from cache" : "Not caching zero TTL cache entry", + dns_resource_key_to_string(rr->key, key_str, sizeof key_str)); + return 0; + } + + /* Entry exists already? Update TTL, timestamp and owner*/ + existing = dns_cache_get(c, rr); + if (existing) { + dns_cache_item_update_positive( + c, + existing, + rr, + authenticated, + shared_owner, + timestamp, + ifindex, + owner_family, + owner_address); + return 0; + } + + /* Otherwise, add the new RR */ + r = dns_cache_init(c); + if (r < 0) + return r; + + dns_cache_make_space(c, 1); + + i = new0(DnsCacheItem, 1); + if (!i) + return -ENOMEM; + + i->type = DNS_CACHE_POSITIVE; + i->key = dns_resource_key_ref(rr->key); + i->rr = dns_resource_record_ref(rr); + i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); + i->authenticated = authenticated; + i->shared_owner = shared_owner; + i->ifindex = ifindex; + i->owner_family = owner_family; + i->owner_address = *owner_address; + i->prioq_idx = PRIOQ_IDX_NULL; + + r = dns_cache_link_item(c, i); + if (r < 0) + return r; + + if (log_get_max_level() >= LOG_DEBUG) { + _cleanup_free_ char *t = NULL; + + (void) in_addr_to_string(i->owner_family, &i->owner_address, &t); + + log_debug("Added positive %s%s cache entry for %s "USEC_FMT"s on %s/%s/%s", + i->authenticated ? "authenticated" : "unauthenticated", + i->shared_owner ? " shared" : "", + dns_resource_key_to_string(i->key, key_str, sizeof key_str), + (i->until - timestamp) / USEC_PER_SEC, + i->ifindex == 0 ? "*" : strna(if_indextoname(i->ifindex, ifname)), + af_to_name_short(i->owner_family), + strna(t)); + } + + i = NULL; + return 0; +} + +static int dns_cache_put_negative( + DnsCache *c, + DnsResourceKey *key, + int rcode, + bool authenticated, + uint32_t nsec_ttl, + usec_t timestamp, + DnsResourceRecord *soa, + int owner_family, + const union in_addr_union *owner_address) { + + _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + int r; + + assert(c); + assert(key); + assert(soa); + assert(owner_address); + + /* Never cache pseudo RR keys. DNS_TYPE_ANY is particularly + * important to filter out as we use this as a pseudo-type for + * NXDOMAIN entries */ + if (dns_class_is_pseudo(key->class)) + return 0; + if (dns_type_is_pseudo(key->type)) + return 0; + + if (nsec_ttl <= 0 || soa->soa.minimum <= 0 || soa->ttl <= 0) { + log_debug("Not caching negative entry with zero SOA/NSEC/NSEC3 TTL: %s", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + return 0; + } + + if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) + return 0; + + r = dns_cache_init(c); + if (r < 0) + return r; + + dns_cache_make_space(c, 1); + + i = new0(DnsCacheItem, 1); + if (!i) + return -ENOMEM; + + i->type = rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : DNS_CACHE_NXDOMAIN; + i->until = calculate_until(soa, nsec_ttl, timestamp, true); + i->authenticated = authenticated; + i->owner_family = owner_family; + i->owner_address = *owner_address; + i->prioq_idx = PRIOQ_IDX_NULL; + + if (i->type == DNS_CACHE_NXDOMAIN) { + /* NXDOMAIN entries should apply equally to all types, so we use ANY as + * a pseudo type for this purpose here. */ + i->key = dns_resource_key_new(key->class, DNS_TYPE_ANY, dns_resource_key_name(key)); + if (!i->key) + return -ENOMEM; + + /* Make sure to remove any previous entry for this + * specific ANY key. (For non-ANY keys the cache data + * is already cleared by the caller.) Note that we + * don't bother removing positive or NODATA cache + * items in this case, because it would either be slow + * or require explicit indexing by name */ + dns_cache_remove_by_key(c, key); + } else + i->key = dns_resource_key_ref(key); + + r = dns_cache_link_item(c, i); + if (r < 0) + return r; + + log_debug("Added %s cache entry for %s "USEC_FMT"s", + i->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", + dns_resource_key_to_string(i->key, key_str, sizeof key_str), + (i->until - timestamp) / USEC_PER_SEC); + + i = NULL; + return 0; +} + +static void dns_cache_remove_previous( + DnsCache *c, + DnsResourceKey *key, + DnsAnswer *answer) { + + DnsResourceRecord *rr; + DnsAnswerFlags flags; + + assert(c); + + /* First, if we were passed a key (i.e. on LLMNR/DNS, but + * not on mDNS), delete all matching old RRs, so that we only + * keep complete by_key in place. */ + if (key) + dns_cache_remove_by_key(c, key); + + /* Second, flush all entries matching the answer, unless this + * is an RR that is explicitly marked to be "shared" between + * peers (i.e. mDNS RRs without the flush-cache bit set). */ + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; + + if (flags & DNS_ANSWER_SHARED_OWNER) + continue; + + dns_cache_remove_by_key(c, rr->key); + } +} + +static bool rr_eligible(DnsResourceRecord *rr) { + assert(rr); + + /* When we see an NSEC/NSEC3 RR, we'll only cache it if it is from the lower zone, not the upper zone, since + * that's where the interesting bits are (with exception of DS RRs). Of course, this way we cannot derive DS + * existence from any cached NSEC/NSEC3, but that should be fine. */ + + switch (rr->key->type) { + + case DNS_TYPE_NSEC: + return !bitmap_isset(rr->nsec.types, DNS_TYPE_NS) || + bitmap_isset(rr->nsec.types, DNS_TYPE_SOA); + + case DNS_TYPE_NSEC3: + return !bitmap_isset(rr->nsec3.types, DNS_TYPE_NS) || + bitmap_isset(rr->nsec3.types, DNS_TYPE_SOA); + + default: + return true; + } +} + +int dns_cache_put( + DnsCache *c, + DnsResourceKey *key, + int rcode, + DnsAnswer *answer, + bool authenticated, + uint32_t nsec_ttl, + usec_t timestamp, + int owner_family, + const union in_addr_union *owner_address) { + + DnsResourceRecord *soa = NULL, *rr; + DnsAnswerFlags flags; + unsigned cache_keys; + int r, ifindex; + + assert(c); + assert(owner_address); + + dns_cache_remove_previous(c, key, answer); + + /* We only care for positive replies and NXDOMAINs, on all + * other replies we will simply flush the respective entries, + * and that's it */ + if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) + return 0; + + if (dns_answer_size(answer) <= 0) { + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + log_debug("Not caching negative entry without a SOA record: %s", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + return 0; + } + + cache_keys = dns_answer_size(answer); + if (key) + cache_keys++; + + /* Make some space for our new entries */ + dns_cache_make_space(c, cache_keys); + + if (timestamp <= 0) + timestamp = now(clock_boottime_or_monotonic()); + + /* Second, add in positive entries for all contained RRs */ + DNS_ANSWER_FOREACH_FULL(rr, ifindex, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; + + r = rr_eligible(rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dns_cache_put_positive( + c, + rr, + flags & DNS_ANSWER_AUTHENTICATED, + flags & DNS_ANSWER_SHARED_OWNER, + timestamp, + ifindex, + owner_family, owner_address); + if (r < 0) + goto fail; + } + + if (!key) /* mDNS doesn't know negative caching, really */ + return 0; + + /* Third, add in negative entries if the key has no RR */ + r = dns_answer_match_key(answer, key, NULL); + if (r < 0) + goto fail; + if (r > 0) + return 0; + + /* But not if it has a matching CNAME/DNAME (the negative + * caching will be done on the canonical name, not on the + * alias) */ + r = dns_answer_find_cname_or_dname(answer, key, NULL, NULL); + if (r < 0) + goto fail; + if (r > 0) + return 0; + + /* See https://tools.ietf.org/html/rfc2308, which say that a + * matching SOA record in the packet is used to enable + * negative caching. */ + r = dns_answer_find_soa(answer, key, &soa, &flags); + if (r < 0) + goto fail; + if (r == 0) + return 0; + + /* Refuse using the SOA data if it is unsigned, but the key is + * signed */ + if (authenticated && (flags & DNS_ANSWER_AUTHENTICATED) == 0) + return 0; + + r = dns_cache_put_negative( + c, + key, + rcode, + authenticated, + nsec_ttl, + timestamp, + soa, + owner_family, owner_address); + if (r < 0) + goto fail; + + return 0; + +fail: + /* Adding all RRs failed. Let's clean up what we already + * added, just in case */ + + if (key) + dns_cache_remove_by_key(c, key); + + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; + + dns_cache_remove_by_key(c, rr->key); + } + + return r; +} + +static DnsCacheItem *dns_cache_get_by_key_follow_cname_dname_nsec(DnsCache *c, DnsResourceKey *k) { + DnsCacheItem *i; + const char *n; + int r; + + assert(c); + assert(k); + + /* If we hit some OOM error, or suchlike, we don't care too + * much, after all this is just a cache */ + + i = hashmap_get(c->by_key, k); + if (i) + return i; + + n = dns_resource_key_name(k); + + /* Check if we have an NXDOMAIN cache item for the name, notice that we use + * the pseudo-type ANY for NXDOMAIN cache items. */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_ANY, n)); + if (i && i->type == DNS_CACHE_NXDOMAIN) + return i; + + if (dns_type_may_redirect(k->type)) { + /* Check if we have a CNAME record instead */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_CNAME, n)); + if (i) + return i; + + /* OK, let's look for cached DNAME records. */ + for (;;) { + if (isempty(n)) + return NULL; + + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_DNAME, n)); + if (i) + return i; + + /* Jump one label ahead */ + r = dns_name_parent(&n); + if (r <= 0) + return NULL; + } + } + + if (k->type != DNS_TYPE_NSEC) { + /* Check if we have an NSEC record instead for the name. */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_NSEC, n)); + if (i) + return i; + } + + return NULL; +} + +int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, bool clamp_ttl, int *rcode, DnsAnswer **ret, bool *authenticated) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + unsigned n = 0; + int r; + bool nxdomain = false; + DnsCacheItem *j, *first, *nsec = NULL; + bool have_authenticated = false, have_non_authenticated = false; + usec_t current; + + assert(c); + assert(key); + assert(rcode); + assert(ret); + assert(authenticated); + + if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { + /* If we have ANY lookups we don't use the cache, so + * that the caller refreshes via the network. */ + + log_debug("Ignoring cache for ANY lookup: %s", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + + c->n_miss++; + + *ret = NULL; + *rcode = DNS_RCODE_SUCCESS; + return 0; + } + + first = dns_cache_get_by_key_follow_cname_dname_nsec(c, key); + if (!first) { + /* If one question cannot be answered we need to refresh */ + + log_debug("Cache miss for %s", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + + c->n_miss++; + + *ret = NULL; + *rcode = DNS_RCODE_SUCCESS; + return 0; + } + + LIST_FOREACH(by_key, j, first) { + if (j->rr) { + if (j->rr->key->type == DNS_TYPE_NSEC) + nsec = j; + + n++; + } else if (j->type == DNS_CACHE_NXDOMAIN) + nxdomain = true; + + if (j->authenticated) + have_authenticated = true; + else + have_non_authenticated = true; + } + + if (nsec && !IN_SET(key->type, DNS_TYPE_NSEC, DNS_TYPE_DS)) { + /* Note that we won't derive information for DS RRs from an NSEC, because we only cache NSEC RRs from + * the lower-zone of a zone cut, but the DS RRs are on the upper zone. */ + + log_debug("NSEC NODATA cache hit for %s", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + + /* We only found an NSEC record that matches our name. + * If it says the type doesn't exist report + * NODATA. Otherwise report a cache miss. */ + + *ret = NULL; + *rcode = DNS_RCODE_SUCCESS; + *authenticated = nsec->authenticated; + + if (!bitmap_isset(nsec->rr->nsec.types, key->type) && + !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_CNAME) && + !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_DNAME)) { + c->n_hit++; + return 1; + } + + c->n_miss++; + return 0; + } + + log_debug("%s cache hit for %s", + n > 0 ? "Positive" : + nxdomain ? "NXDOMAIN" : "NODATA", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + + if (n <= 0) { + c->n_hit++; + + *ret = NULL; + *rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS; + *authenticated = have_authenticated && !have_non_authenticated; + return 1; + } + + answer = dns_answer_new(n); + if (!answer) + return -ENOMEM; + + if (clamp_ttl) + current = now(clock_boottime_or_monotonic()); + + LIST_FOREACH(by_key, j, first) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + if (!j->rr) + continue; + + if (clamp_ttl) { + rr = dns_resource_record_ref(j->rr); + + r = dns_resource_record_clamp_ttl(&rr, LESS_BY(j->until, current) / USEC_PER_SEC); + if (r < 0) + return r; + } + + r = dns_answer_add(answer, rr ?: j->rr, j->ifindex, j->authenticated ? DNS_ANSWER_AUTHENTICATED : 0); + if (r < 0) + return r; + } + + c->n_hit++; + + *ret = answer; + *rcode = DNS_RCODE_SUCCESS; + *authenticated = have_authenticated && !have_non_authenticated; + answer = NULL; + + return n; +} + +int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address) { + DnsCacheItem *i, *first; + bool same_owner = true; + + assert(cache); + assert(rr); + + dns_cache_prune(cache); + + /* See if there's a cache entry for the same key. If there + * isn't there's no conflict */ + first = hashmap_get(cache->by_key, rr->key); + if (!first) + return 0; + + /* See if the RR key is owned by the same owner, if so, there + * isn't a conflict either */ + LIST_FOREACH(by_key, i, first) { + if (i->owner_family != owner_family || + !in_addr_equal(owner_family, &i->owner_address, owner_address)) { + same_owner = false; + break; + } + } + if (same_owner) + return 0; + + /* See if there's the exact same RR in the cache. If yes, then + * there's no conflict. */ + if (dns_cache_get(cache, rr)) + return 0; + + /* There's a conflict */ + return 1; +} + +int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p) { + unsigned ancount = 0; + Iterator iterator; + DnsCacheItem *i; + int r; + + assert(cache); + assert(p); + + HASHMAP_FOREACH(i, cache->by_key, iterator) { + DnsCacheItem *j; + + LIST_FOREACH(by_key, j, i) { + if (!j->rr) + continue; + + if (!j->shared_owner) + continue; + + r = dns_packet_append_rr(p, j->rr, NULL, NULL); + if (r == -EMSGSIZE && p->protocol == DNS_PROTOCOL_MDNS) { + /* For mDNS, if we're unable to stuff all known answers into the given packet, + * allocate a new one, push the RR into that one and link it to the current one. + */ + + DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); + ancount = 0; + + r = dns_packet_new_query(&p->more, p->protocol, 0, true); + if (r < 0) + return r; + + /* continue with new packet */ + p = p->more; + r = dns_packet_append_rr(p, j->rr, NULL, NULL); + } + + if (r < 0) + return r; + + ancount++; + } + } + + DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); + + return 0; +} + +void dns_cache_dump(DnsCache *cache, FILE *f) { + Iterator iterator; + DnsCacheItem *i; + + if (!cache) + return; + + if (!f) + f = stdout; + + HASHMAP_FOREACH(i, cache->by_key, iterator) { + DnsCacheItem *j; + + LIST_FOREACH(by_key, j, i) { + + fputc('\t', f); + + if (j->rr) { + const char *t; + t = dns_resource_record_to_string(j->rr); + if (!t) { + log_oom(); + continue; + } + + fputs(t, f); + fputc('\n', f); + } else { + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + fputs(dns_resource_key_to_string(j->key, key_str, sizeof key_str), f); + fputs(" -- ", f); + fputs(j->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", f); + fputc('\n', f); + } + } + } +} + +bool dns_cache_is_empty(DnsCache *cache) { + if (!cache) + return true; + + return hashmap_isempty(cache->by_key); +} + +unsigned dns_cache_size(DnsCache *cache) { + if (!cache) + return 0; + + return hashmap_size(cache->by_key); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-cache.h b/src/grp-resolve/systemd-resolved/resolved-dns-cache.h new file mode 100644 index 0000000000..c2b6a987b9 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-cache.h @@ -0,0 +1,52 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/hashmap.h" +#include "systemd-basic/list.h" +#include "systemd-basic/prioq.h" +#include "systemd-basic/time-util.h" + +typedef struct DnsCache { + Hashmap *by_key; + Prioq *by_expiry; + unsigned n_hit; + unsigned n_miss; +} DnsCache; + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-packet.h" +#include "basic-dns/resolved-dns-question.h" +#include "basic-dns/resolved-dns-rr.h" + +void dns_cache_flush(DnsCache *c); +void dns_cache_prune(DnsCache *c); + +int dns_cache_put(DnsCache *c, DnsResourceKey *key, int rcode, DnsAnswer *answer, bool authenticated, uint32_t nsec_ttl, usec_t timestamp, int owner_family, const union in_addr_union *owner_address); +int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, bool clamp_ttl, int *rcode, DnsAnswer **answer, bool *authenticated); + +int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address); + +void dns_cache_dump(DnsCache *cache, FILE *f); +bool dns_cache_is_empty(DnsCache *cache); + +unsigned dns_cache_size(DnsCache *cache); + +int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-query.c b/src/grp-resolve/systemd-resolved/resolved-dns-query.c new file mode 100644 index 0000000000..2193dc5bcf --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-query.c @@ -0,0 +1,1118 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/dns-type.h" +#include "sd-netlink/local-addresses.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-query.h" +#include "resolved-dns-synthesize.h" +#include "resolved-etc-hosts.h" + +/* How long to wait for the query in total */ +#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC) + +#define CNAME_MAX 8 +#define QUERIES_MAX 2048 +#define AUXILIARY_QUERIES_MAX 64 + +static int dns_query_candidate_new(DnsQueryCandidate **ret, DnsQuery *q, DnsScope *s) { + DnsQueryCandidate *c; + + assert(ret); + assert(q); + assert(s); + + c = new0(DnsQueryCandidate, 1); + if (!c) + return -ENOMEM; + + c->query = q; + c->scope = s; + + LIST_PREPEND(candidates_by_query, q->candidates, c); + LIST_PREPEND(candidates_by_scope, s->query_candidates, c); + + *ret = c; + return 0; +} + +static void dns_query_candidate_stop(DnsQueryCandidate *c) { + DnsTransaction *t; + + assert(c); + + while ((t = set_steal_first(c->transactions))) { + set_remove(t->notify_query_candidates, c); + set_remove(t->notify_query_candidates_done, c); + dns_transaction_gc(t); + } +} + +DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c) { + + if (!c) + return NULL; + + dns_query_candidate_stop(c); + + set_free(c->transactions); + dns_search_domain_unref(c->search_domain); + + if (c->query) + LIST_REMOVE(candidates_by_query, c->query->candidates, c); + + if (c->scope) + LIST_REMOVE(candidates_by_scope, c->scope->query_candidates, c); + + return mfree(c); +} + +static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) { + DnsSearchDomain *next = NULL; + + assert(c); + + if (c->search_domain && c->search_domain->linked) + next = c->search_domain->domains_next; + else + next = dns_scope_get_search_domains(c->scope); + + for (;;) { + if (!next) /* We hit the end of the list */ + return 0; + + if (!next->route_only) + break; + + /* Skip over route-only domains */ + next = next->domains_next; + } + + dns_search_domain_unref(c->search_domain); + c->search_domain = dns_search_domain_ref(next); + + return 1; +} + +static int dns_query_candidate_add_transaction(DnsQueryCandidate *c, DnsResourceKey *key) { + DnsTransaction *t; + int r; + + assert(c); + assert(key); + + t = dns_scope_find_transaction(c->scope, key, true); + if (!t) { + r = dns_transaction_new(&t, c->scope, key); + if (r < 0) + return r; + } else { + if (set_contains(c->transactions, t)) + return 0; + } + + r = set_ensure_allocated(&c->transactions, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&t->notify_query_candidates, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&t->notify_query_candidates_done, NULL); + if (r < 0) + goto gc; + + r = set_put(t->notify_query_candidates, c); + if (r < 0) + goto gc; + + r = set_put(c->transactions, t); + if (r < 0) { + (void) set_remove(t->notify_query_candidates, c); + goto gc; + } + + t->clamp_ttl = c->query->clamp_ttl; + return 1; + +gc: + dns_transaction_gc(t); + return r; +} + +static int dns_query_candidate_go(DnsQueryCandidate *c) { + DnsTransaction *t; + Iterator i; + int r; + unsigned n = 0; + + assert(c); + + /* Start the transactions that are not started yet */ + SET_FOREACH(t, c->transactions, i) { + if (t->state != DNS_TRANSACTION_NULL) + continue; + + r = dns_transaction_go(t); + if (r < 0) + return r; + + n++; + } + + /* If there was nothing to start, then let's proceed immediately */ + if (n == 0) + dns_query_candidate_notify(c); + + return 0; +} + +static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { + DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; + DnsTransaction *t; + Iterator i; + + assert(c); + + if (c->error_code != 0) + return DNS_TRANSACTION_ERRNO; + + SET_FOREACH(t, c->transactions, i) { + + switch (t->state) { + + case DNS_TRANSACTION_NULL: + /* If there's a NULL transaction pending, then + * this means not all transactions where + * started yet, and we were called from within + * the stackframe that is supposed to start + * remaining transactions. In this case, + * simply claim the candidate is pending. */ + + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* If there's one transaction currently in + * VALIDATING state, then this means there's + * also one in PENDING state, hence we can + * return PENDING immediately. */ + return DNS_TRANSACTION_PENDING; + + case DNS_TRANSACTION_SUCCESS: + state = t->state; + break; + + default: + if (state != DNS_TRANSACTION_SUCCESS) + state = t->state; + + break; + } + } + + return state; +} + +static bool dns_query_candidate_is_routable(DnsQueryCandidate *c, uint16_t type) { + int family; + + assert(c); + + /* Checks whether the specified RR type matches an address family that is routable on the link(s) the scope of + * this candidate belongs to. Specifically, whether there's a routable IPv4 address on it if we query an A RR, + * or a routable IPv6 address if we query an AAAA RR. */ + + if (!c->query->suppress_unroutable_family) + return true; + + if (c->scope->protocol != DNS_PROTOCOL_DNS) + return true; + + family = dns_type_to_af(type); + if (family < 0) + return true; + + if (c->scope->link) + return link_relevant(c->scope->link, family, false); + else + return manager_routable(c->scope->manager, family); +} + +static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { + DnsQuestion *question; + DnsResourceKey *key; + int n = 0, r; + + assert(c); + + dns_query_candidate_stop(c); + + question = dns_query_question_for_protocol(c->query, c->scope->protocol); + + /* Create one transaction per question key */ + DNS_QUESTION_FOREACH(key, question) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL; + DnsResourceKey *qkey; + + if (!dns_query_candidate_is_routable(c, key->type)) + continue; + + if (c->search_domain) { + r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name); + if (r < 0) + goto fail; + + qkey = new_key; + } else + qkey = key; + + if (!dns_scope_good_key(c->scope, qkey)) + continue; + + r = dns_query_candidate_add_transaction(c, qkey); + if (r < 0) + goto fail; + + n++; + } + + return n; + +fail: + dns_query_candidate_stop(c); + return r; +} + +void dns_query_candidate_notify(DnsQueryCandidate *c) { + DnsTransactionState state; + int r; + + assert(c); + + state = dns_query_candidate_state(c); + + if (DNS_TRANSACTION_IS_LIVE(state)) + return; + + if (state != DNS_TRANSACTION_SUCCESS && c->search_domain) { + + r = dns_query_candidate_next_search_domain(c); + if (r < 0) + goto fail; + + if (r > 0) { + /* OK, there's another search domain to try, let's do so. */ + + r = dns_query_candidate_setup_transactions(c); + if (r < 0) + goto fail; + + if (r > 0) { + /* New transactions where queued. Start them and wait */ + + r = dns_query_candidate_go(c); + if (r < 0) + goto fail; + + return; + } + } + + } + + dns_query_ready(c->query); + return; + +fail: + log_warning_errno(r, "Failed to follow search domains: %m"); + c->error_code = r; + dns_query_ready(c->query); +} + +static void dns_query_stop(DnsQuery *q) { + DnsQueryCandidate *c; + + assert(q); + + q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); + + LIST_FOREACH(candidates_by_query, c, q->candidates) + dns_query_candidate_stop(c); +} + +static void dns_query_free_candidates(DnsQuery *q) { + assert(q); + + while (q->candidates) + dns_query_candidate_free(q->candidates); +} + +static void dns_query_reset_answer(DnsQuery *q) { + assert(q); + + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = 0; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_errno = 0; + q->answer_authenticated = false; + q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; + q->answer_search_domain = dns_search_domain_unref(q->answer_search_domain); +} + +DnsQuery *dns_query_free(DnsQuery *q) { + if (!q) + return NULL; + + while (q->auxiliary_queries) + dns_query_free(q->auxiliary_queries); + + if (q->auxiliary_for) { + assert(q->auxiliary_for->n_auxiliary_queries > 0); + q->auxiliary_for->n_auxiliary_queries--; + LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q); + } + + dns_query_free_candidates(q); + + dns_question_unref(q->question_idna); + dns_question_unref(q->question_utf8); + + dns_query_reset_answer(q); + + sd_bus_message_unref(q->request); + sd_bus_track_unref(q->bus_track); + + dns_packet_unref(q->request_dns_packet); + + if (q->request_dns_stream) { + /* Detach the stream from our query, in case something else keeps a reference to it. */ + q->request_dns_stream->complete = NULL; + q->request_dns_stream->on_packet = NULL; + q->request_dns_stream->query = NULL; + dns_stream_unref(q->request_dns_stream); + } + + free(q->request_address_string); + + if (q->manager) { + LIST_REMOVE(queries, q->manager->dns_queries, q); + q->manager->n_dns_queries--; + } + + return mfree(q); +} + +int dns_query_new( + Manager *m, + DnsQuery **ret, + DnsQuestion *question_utf8, + DnsQuestion *question_idna, + int ifindex, + uint64_t flags) { + + _cleanup_(dns_query_freep) DnsQuery *q = NULL; + DnsResourceKey *key; + bool good = false; + int r; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + assert(m); + + if (dns_question_size(question_utf8) > 0) { + r = dns_question_is_valid_for_query(question_utf8); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + good = true; + } + + /* If the IDNA and UTF8 questions are the same, merge their references */ + r = dns_question_is_equal(question_idna, question_utf8); + if (r < 0) + return r; + if (r > 0) + question_idna = question_utf8; + else { + if (dns_question_size(question_idna) > 0) { + r = dns_question_is_valid_for_query(question_idna); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + good = true; + } + } + + if (!good) /* don't allow empty queries */ + return -EINVAL; + + if (m->n_dns_queries >= QUERIES_MAX) + return -EBUSY; + + q = new0(DnsQuery, 1); + if (!q) + return -ENOMEM; + + q->question_utf8 = dns_question_ref(question_utf8); + q->question_idna = dns_question_ref(question_idna); + q->ifindex = ifindex; + q->flags = flags; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; + + /* First dump UTF8 question */ + DNS_QUESTION_FOREACH(key, question_utf8) + log_debug("Looking up RR for %s.", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + + /* And then dump the IDNA question, but only what hasn't been dumped already through the UTF8 question. */ + DNS_QUESTION_FOREACH(key, question_idna) { + r = dns_question_contains(question_utf8, key); + if (r < 0) + return r; + if (r > 0) + continue; + + log_debug("Looking up IDNA RR for %s.", + dns_resource_key_to_string(key, key_str, sizeof key_str)); + } + + LIST_PREPEND(queries, m->dns_queries, q); + m->n_dns_queries++; + q->manager = m; + + if (ret) + *ret = q; + q = NULL; + + return 0; +} + +int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for) { + assert(q); + assert(auxiliary_for); + + /* Ensure that the query is not auxiliary yet, and + * nothing else is auxiliary to it either */ + assert(!q->auxiliary_for); + assert(!q->auxiliary_queries); + + /* Ensure that the unit we shall be made auxiliary for isn't + * auxiliary itself */ + assert(!auxiliary_for->auxiliary_for); + + if (auxiliary_for->n_auxiliary_queries >= AUXILIARY_QUERIES_MAX) + return -EAGAIN; + + LIST_PREPEND(auxiliary_queries, auxiliary_for->auxiliary_queries, q); + q->auxiliary_for = auxiliary_for; + + auxiliary_for->n_auxiliary_queries++; + return 0; +} + +static void dns_query_complete(DnsQuery *q, DnsTransactionState state) { + assert(q); + assert(!DNS_TRANSACTION_IS_LIVE(state)); + assert(DNS_TRANSACTION_IS_LIVE(q->state)); + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function. */ + + q->state = state; + + dns_query_stop(q); + if (q->complete) + q->complete(q); +} + +static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) { + DnsQuery *q = userdata; + + assert(s); + assert(q); + + dns_query_complete(q, DNS_TRANSACTION_TIMEOUT); + return 0; +} + +static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) { + DnsQueryCandidate *c; + int r; + + assert(q); + assert(s); + + r = dns_query_candidate_new(&c, q, s); + if (r < 0) + return r; + + /* If this a single-label domain on DNS, we might append a suitable search domain first. */ + if ((q->flags & SD_RESOLVED_NO_SEARCH) == 0) { + r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question_idna)); + if (r < 0) + goto fail; + if (r > 0) { + /* OK, we need a search domain now. Let's find one for this scope */ + + r = dns_query_candidate_next_search_domain(c); + if (r <= 0) /* if there's no search domain, then we won't add any transaction. */ + goto fail; + } + } + + r = dns_query_candidate_setup_transactions(c); + if (r < 0) + goto fail; + + return 0; + +fail: + dns_query_candidate_free(c); + return r; +} + +static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; + + assert(q); + assert(state); + + /* Tries to synthesize localhost RR replies (and others) where appropriate. Note that this is done *after* the + * the normal lookup finished. The data from the network hence takes precedence over the data we + * synthesize. (But note that many scopes refuse to resolve certain domain names) */ + + if (!IN_SET(*state, + DNS_TRANSACTION_RCODE_FAILURE, + DNS_TRANSACTION_NO_SERVERS, + DNS_TRANSACTION_TIMEOUT, + DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, + DNS_TRANSACTION_NETWORK_DOWN, + DNS_TRANSACTION_NOT_FOUND)) + return 0; + + r = dns_synthesize_answer( + q->manager, + q->question_utf8, + q->ifindex, + &answer); + + if (r <= 0) + return r; + + dns_query_reset_answer(q); + + q->answer = answer; + answer = NULL; + q->answer_rcode = DNS_RCODE_SUCCESS; + q->answer_protocol = dns_synthesize_protocol(q->flags); + q->answer_family = dns_synthesize_family(q->flags); + q->answer_authenticated = true; + + *state = DNS_TRANSACTION_SUCCESS; + + return 1; +} + +static int dns_query_try_etc_hosts(DnsQuery *q) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; + + assert(q); + + /* Looks in /etc/hosts for matching entries. Note that this is done *before* the normal lookup is done. The + * data from /etc/hosts hence takes precedence over the network. */ + + r = manager_etc_hosts_lookup( + q->manager, + q->question_utf8, + &answer); + if (r <= 0) + return r; + + dns_query_reset_answer(q); + + q->answer = answer; + answer = NULL; + q->answer_rcode = DNS_RCODE_SUCCESS; + q->answer_protocol = dns_synthesize_protocol(q->flags); + q->answer_family = dns_synthesize_family(q->flags); + q->answer_authenticated = true; + + return 1; +} + +int dns_query_go(DnsQuery *q) { + DnsScopeMatch found = DNS_SCOPE_NO; + DnsScope *s, *first = NULL; + DnsQueryCandidate *c; + int r; + + assert(q); + + if (q->state != DNS_TRANSACTION_NULL) + return 0; + + r = dns_query_try_etc_hosts(q); + if (r < 0) + return r; + if (r > 0) { + dns_query_complete(q, DNS_TRANSACTION_SUCCESS); + return 1; + } + + LIST_FOREACH(scopes, s, q->manager->dns_scopes) { + DnsScopeMatch match; + const char *name; + + name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol)); + if (!name) + continue; + + match = dns_scope_good_domain(s, q->ifindex, q->flags, name); + if (match < 0) + return match; + + if (match == DNS_SCOPE_NO) + continue; + + found = match; + + if (match == DNS_SCOPE_YES) { + first = s; + break; + } else { + assert(match == DNS_SCOPE_MAYBE); + + if (!first) + first = s; + } + } + + if (found == DNS_SCOPE_NO) { + DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; + + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + return r; + + dns_query_complete(q, state); + return 1; + } + + r = dns_query_add_candidate(q, first); + if (r < 0) + goto fail; + + LIST_FOREACH(scopes, s, first->scopes_next) { + DnsScopeMatch match; + const char *name; + + name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol)); + if (!name) + continue; + + match = dns_scope_good_domain(s, q->ifindex, q->flags, name); + if (match < 0) + goto fail; + + if (match != found) + continue; + + r = dns_query_add_candidate(q, s); + if (r < 0) + goto fail; + } + + dns_query_reset_answer(q); + + r = sd_event_add_time( + q->manager->event, + &q->timeout_event_source, + clock_boottime_or_monotonic(), + now(clock_boottime_or_monotonic()) + QUERY_TIMEOUT_USEC, 0, + on_query_timeout, q); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(q->timeout_event_source, "query-timeout"); + + q->state = DNS_TRANSACTION_PENDING; + q->block_ready++; + + /* Start the transactions */ + LIST_FOREACH(candidates_by_query, c, q->candidates) { + r = dns_query_candidate_go(c); + if (r < 0) { + q->block_ready--; + goto fail; + } + } + + q->block_ready--; + dns_query_ready(q); + + return 1; + +fail: + dns_query_stop(q); + return r; +} + +static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { + DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; + bool has_authenticated = false, has_non_authenticated = false; + DnssecResult dnssec_result_authenticated = _DNSSEC_RESULT_INVALID, dnssec_result_non_authenticated = _DNSSEC_RESULT_INVALID; + DnsTransaction *t; + Iterator i; + int r; + + assert(q); + + if (!c) { + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + goto fail; + + dns_query_complete(q, state); + return; + } + + if (c->error_code != 0) { + /* If the candidate had an error condition of its own, start with that. */ + state = DNS_TRANSACTION_ERRNO; + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = 0; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_errno = c->error_code; + } + + SET_FOREACH(t, c->transactions, i) { + + switch (t->state) { + + case DNS_TRANSACTION_SUCCESS: { + /* We found a successfully reply, merge it into the answer */ + r = dns_answer_extend(&q->answer, t->answer); + if (r < 0) + goto fail; + + q->answer_rcode = t->answer_rcode; + q->answer_errno = 0; + + if (t->answer_authenticated) { + has_authenticated = true; + dnssec_result_authenticated = t->answer_dnssec_result; + } else { + has_non_authenticated = true; + dnssec_result_non_authenticated = t->answer_dnssec_result; + } + + state = DNS_TRANSACTION_SUCCESS; + break; + } + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + case DNS_TRANSACTION_ABORTED: + /* Ignore transactions that didn't complete */ + continue; + + default: + /* Any kind of failure? Store the data away, + * if there's nothing stored yet. */ + + if (state == DNS_TRANSACTION_SUCCESS) + continue; + + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = t->answer_rcode; + q->answer_dnssec_result = t->answer_dnssec_result; + q->answer_errno = t->answer_errno; + + state = t->state; + break; + } + } + + if (state == DNS_TRANSACTION_SUCCESS) { + q->answer_authenticated = has_authenticated && !has_non_authenticated; + q->answer_dnssec_result = q->answer_authenticated ? dnssec_result_authenticated : dnssec_result_non_authenticated; + } + + q->answer_protocol = c->scope->protocol; + q->answer_family = c->scope->family; + + dns_search_domain_unref(q->answer_search_domain); + q->answer_search_domain = dns_search_domain_ref(c->search_domain); + + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + goto fail; + + dns_query_complete(q, state); + return; + +fail: + q->answer_errno = -r; + dns_query_complete(q, DNS_TRANSACTION_ERRNO); +} + +void dns_query_ready(DnsQuery *q) { + + DnsQueryCandidate *bad = NULL, *c; + bool pending = false; + + assert(q); + assert(DNS_TRANSACTION_IS_LIVE(q->state)); + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function, unless the block_ready + * counter was explicitly bumped before doing so. */ + + if (q->block_ready > 0) + return; + + LIST_FOREACH(candidates_by_query, c, q->candidates) { + DnsTransactionState state; + + state = dns_query_candidate_state(c); + switch (state) { + + case DNS_TRANSACTION_SUCCESS: + /* One of the candidates is successful, + * let's use it, and copy its data out */ + dns_query_accept(q, c); + return; + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* One of the candidates is still going on, + * let's maybe wait for it */ + pending = true; + break; + + default: + /* Any kind of failure */ + bad = c; + break; + } + } + + if (pending) + return; + + dns_query_accept(q, bad); +} + +static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) { + _cleanup_(dns_question_unrefp) DnsQuestion *nq_idna = NULL, *nq_utf8 = NULL; + int r, k; + + assert(q); + + q->n_cname_redirects++; + if (q->n_cname_redirects > CNAME_MAX) + return -ELOOP; + + r = dns_question_cname_redirect(q->question_idna, cname, &nq_idna); + if (r < 0) + return r; + else if (r > 0) + log_debug("Following CNAME/DNAME %s → %s.", dns_question_first_name(q->question_idna), dns_question_first_name(nq_idna)); + + k = dns_question_is_equal(q->question_idna, q->question_utf8); + if (k < 0) + return r; + if (k > 0) { + /* Same question? Shortcut new question generation */ + nq_utf8 = dns_question_ref(nq_idna); + k = r; + } else { + k = dns_question_cname_redirect(q->question_utf8, cname, &nq_utf8); + if (k < 0) + return k; + else if (k > 0) + log_debug("Following UTF8 CNAME/DNAME %s → %s.", dns_question_first_name(q->question_utf8), dns_question_first_name(nq_utf8)); + } + + if (r == 0 && k == 0) /* No actual cname happened? */ + return -ELOOP; + + if (q->answer_protocol == DNS_PROTOCOL_DNS) { + /* Don't permit CNAME redirects from unicast DNS to LLMNR or MulticastDNS, so that global resources + * cannot invade the local namespace. The opposite way we permit: local names may redirect to global + * ones. */ + + q->flags &= ~(SD_RESOLVED_LLMNR|SD_RESOLVED_MDNS); /* mask away the local protocols */ + } + + /* Turn off searching for the new name */ + q->flags |= SD_RESOLVED_NO_SEARCH; + + dns_question_unref(q->question_idna); + q->question_idna = nq_idna; + nq_idna = NULL; + + dns_question_unref(q->question_utf8); + q->question_utf8 = nq_utf8; + nq_utf8 = NULL; + + dns_query_free_candidates(q); + dns_query_reset_answer(q); + + q->state = DNS_TRANSACTION_NULL; + + return 0; +} + +int dns_query_process_cname(DnsQuery *q) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + int r; + + assert(q); + + if (!IN_SET(q->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NULL)) + return DNS_QUERY_NOMATCH; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + if (r < 0) + return r; + if (r > 0) + return DNS_QUERY_MATCH; /* The answer matches directly, no need to follow cnames */ + + r = dns_question_matches_cname_or_dname(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + if (r < 0) + return r; + if (r > 0 && !cname) + cname = dns_resource_record_ref(rr); + } + + if (!cname) + return DNS_QUERY_NOMATCH; /* No match and no cname to follow */ + + if (q->flags & SD_RESOLVED_NO_CNAME) + return -ELOOP; + + /* OK, let's actually follow the CNAME */ + r = dns_query_cname_redirect(q, cname); + if (r < 0) + return r; + + /* Let's see if the answer can already answer the new + * redirected question */ + r = dns_query_process_cname(q); + if (r != DNS_QUERY_NOMATCH) + return r; + + /* OK, it cannot, let's begin with the new query */ + r = dns_query_go(q); + if (r < 0) + return r; + + return DNS_QUERY_RESTARTED; /* We restarted the query for a new cname */ +} + +static int on_bus_track(sd_bus_track *t, void *userdata) { + DnsQuery *q = userdata; + + assert(t); + assert(q); + + log_debug("Client of active query vanished, aborting query."); + dns_query_complete(q, DNS_TRANSACTION_ABORTED); + return 0; +} + +int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) { + int r; + + assert(q); + assert(m); + + if (!q->bus_track) { + r = sd_bus_track_new(sd_bus_message_get_bus(m), &q->bus_track, on_bus_track, q); + if (r < 0) + return r; + } + + r = sd_bus_track_add_sender(q->bus_track, m); + if (r < 0) + return r; + + return 0; +} + +DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol) { + assert(q); + + switch (protocol) { + + case DNS_PROTOCOL_DNS: + return q->question_idna; + + case DNS_PROTOCOL_MDNS: + case DNS_PROTOCOL_LLMNR: + return q->question_utf8; + + default: + return NULL; + } +} + +const char *dns_query_string(DnsQuery *q) { + const char *name; + int r; + + /* Returns a somewhat useful human-readable lookup key string for this query */ + + if (q->request_address_string) + return q->request_address_string; + + if (q->request_address_valid) { + r = in_addr_to_string(q->request_family, &q->request_address, &q->request_address_string); + if (r >= 0) + return q->request_address_string; + } + + name = dns_question_first_name(q->question_utf8); + if (name) + return name; + + return dns_question_first_name(q->question_idna); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-query.h b/src/grp-resolve/systemd-resolved/resolved-dns-query.h new file mode 100644 index 0000000000..bc26a58f21 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-query.h @@ -0,0 +1,141 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + + +#include <systemd/sd-bus.h> + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-question.h" +#include "systemd-basic/set.h" + +typedef struct DnsQuery DnsQuery; +typedef struct DnsQueryCandidate DnsQueryCandidate; + +#include "resolved-dns-search-domain.h" +#include "resolved-dns-stream.h" + +struct DnsQueryCandidate { + DnsQuery *query; + DnsScope *scope; + + DnsSearchDomain *search_domain; + + int error_code; + Set *transactions; + + LIST_FIELDS(DnsQueryCandidate, candidates_by_query); + LIST_FIELDS(DnsQueryCandidate, candidates_by_scope); +}; + +struct DnsQuery { + Manager *manager; + + /* When resolving a service, we first create a TXT+SRV query, + * and then for the hostnames we discover auxiliary A+AAAA + * queries. This pointer always points from the auxiliary + * queries back to the TXT+SRV query. */ + DnsQuery *auxiliary_for; + LIST_HEAD(DnsQuery, auxiliary_queries); + unsigned n_auxiliary_queries; + int auxiliary_result; + + /* The question, formatted in IDNA for use on classic DNS, and as UTF8 for use in LLMNR or mDNS. Note that even + * on classic DNS some labels might use UTF8 encoding. Specifically, DNS-SD service names (in contrast to their + * domain suffixes) use UTF-8 encoding even on DNS. Thus, the difference between these two fields is mostly + * relevant only for explicit *hostname* lookups as well as the domain suffixes of service lookups. */ + DnsQuestion *question_idna; + DnsQuestion *question_utf8; + + uint64_t flags; + int ifindex; + + /* If true, A or AAAA RR lookups will be suppressed on links with no routable address of the matching address + * family */ + bool suppress_unroutable_family; + + + /* If true, the RR TTLs of the answer will be clamped by their current left validity in the cache */ + bool clamp_ttl; + + DnsTransactionState state; + unsigned n_cname_redirects; + + LIST_HEAD(DnsQueryCandidate, candidates); + sd_event_source *timeout_event_source; + + /* Discovered data */ + DnsAnswer *answer; + int answer_rcode; + DnssecResult answer_dnssec_result; + bool answer_authenticated; + DnsProtocol answer_protocol; + int answer_family; + DnsSearchDomain *answer_search_domain; + int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */ + + /* Bus client information */ + sd_bus_message *request; + int request_family; + bool request_address_valid; + union in_addr_union request_address; + unsigned block_all_complete; + char *request_address_string; + + /* DNS stub information */ + DnsPacket *request_dns_packet; + DnsStream *request_dns_stream; + + /* Completion callback */ + void (*complete)(DnsQuery* q); + unsigned block_ready; + + sd_bus_track *bus_track; + + LIST_FIELDS(DnsQuery, queries); + LIST_FIELDS(DnsQuery, auxiliary_queries); +}; + +enum { + DNS_QUERY_MATCH, + DNS_QUERY_NOMATCH, + DNS_QUERY_RESTARTED, +}; + +DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c); +void dns_query_candidate_notify(DnsQueryCandidate *c); + +int dns_query_new(Manager *m, DnsQuery **q, DnsQuestion *question_utf8, DnsQuestion *question_idna, int family, uint64_t flags); +DnsQuery *dns_query_free(DnsQuery *q); + +int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for); + +int dns_query_go(DnsQuery *q); +void dns_query_ready(DnsQuery *q); + +int dns_query_process_cname(DnsQuery *q); + +int dns_query_bus_track(DnsQuery *q, sd_bus_message *m); + +DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol); + +const char *dns_query_string(DnsQuery *q); + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-scope.c b/src/grp-resolve/systemd-resolved/resolved-dns-scope.c new file mode 100644 index 0000000000..9f20fd304a --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-scope.c @@ -0,0 +1,1044 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <netinet/tcp.h> + +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/missing.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/strv.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-scope.h" +#include "resolved-llmnr.h" +#include "resolved-mdns.h" + +#define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) +#define MULTICAST_RATELIMIT_BURST 1000 + +/* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ +#define MULTICAST_RESEND_TIMEOUT_MIN_USEC (100 * USEC_PER_MSEC) +#define MULTICAST_RESEND_TIMEOUT_MAX_USEC (1 * USEC_PER_SEC) + +int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) { + DnsScope *s; + + assert(m); + assert(ret); + + s = new0(DnsScope, 1); + if (!s) + return -ENOMEM; + + s->manager = m; + s->link = l; + s->protocol = protocol; + s->family = family; + s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC; + + if (protocol == DNS_PROTOCOL_DNS) { + /* Copy DNSSEC mode from the link if it is set there, + * otherwise take the manager's DNSSEC mode. Note that + * we copy this only at scope creation time, and do + * not update it from the on, even if the setting + * changes. */ + + if (l) + s->dnssec_mode = link_get_dnssec_mode(l); + else + s->dnssec_mode = manager_get_dnssec_mode(m); + } else + s->dnssec_mode = DNSSEC_NO; + + LIST_PREPEND(scopes, m->dns_scopes, s); + + dns_scope_llmnr_membership(s, true); + dns_scope_mdns_membership(s, true); + + log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family)); + + /* Enforce ratelimiting for the multicast protocols */ + RATELIMIT_INIT(s->ratelimit, MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST); + + *ret = s; + return 0; +} + +static void dns_scope_abort_transactions(DnsScope *s) { + assert(s); + + while (s->transactions) { + DnsTransaction *t = s->transactions; + + /* Abort the transaction, but make sure it is not + * freed while we still look at it */ + + t->block_gc++; + if (DNS_TRANSACTION_IS_LIVE(t->state)) + dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); + t->block_gc--; + + dns_transaction_free(t); + } +} + +DnsScope* dns_scope_free(DnsScope *s) { + DnsResourceRecord *rr; + + if (!s) + return NULL; + + log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family)); + + dns_scope_llmnr_membership(s, false); + dns_scope_mdns_membership(s, false); + dns_scope_abort_transactions(s); + + while (s->query_candidates) + dns_query_candidate_free(s->query_candidates); + + hashmap_free(s->transactions_by_key); + + while ((rr = ordered_hashmap_steal_first(s->conflict_queue))) + dns_resource_record_unref(rr); + + ordered_hashmap_free(s->conflict_queue); + sd_event_source_unref(s->conflict_event_source); + + dns_cache_flush(&s->cache); + dns_zone_flush(&s->zone); + + LIST_REMOVE(scopes, s->manager->dns_scopes, s); + return mfree(s); +} + +DnsServer *dns_scope_get_dns_server(DnsScope *s) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return NULL; + + if (s->link) + return link_get_dns_server(s->link); + else + return manager_get_dns_server(s->manager); +} + +void dns_scope_next_dns_server(DnsScope *s) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return; + + if (s->link) + link_next_dns_server(s->link); + else + manager_next_dns_server(s->manager); +} + +void dns_scope_packet_received(DnsScope *s, usec_t rtt) { + assert(s); + + if (rtt <= s->max_rtt) + return; + + s->max_rtt = rtt; + s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); +} + +void dns_scope_packet_lost(DnsScope *s, usec_t usec) { + assert(s); + + if (s->resend_timeout <= usec) + s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); +} + +static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { + union in_addr_union addr; + int ifindex = 0, r; + int family; + uint32_t mtu; + + assert(s); + assert(p); + assert(p->protocol == s->protocol); + + if (s->link) { + mtu = s->link->mtu; + ifindex = s->link->ifindex; + } else + mtu = manager_find_mtu(s->manager); + + switch (s->protocol) { + + case DNS_PROTOCOL_DNS: + assert(fd >= 0); + + if (DNS_PACKET_QDCOUNT(p) > 1) + return -EOPNOTSUPP; + + if (p->size > DNS_PACKET_UNICAST_SIZE_MAX) + return -EMSGSIZE; + + if (p->size + UDP_PACKET_HEADER_SIZE > mtu) + return -EMSGSIZE; + + r = manager_write(s->manager, fd, p); + if (r < 0) + return r; + + break; + + case DNS_PROTOCOL_LLMNR: + assert(fd < 0); + + if (DNS_PACKET_QDCOUNT(p) > 1) + return -EOPNOTSUPP; + + if (!ratelimit_test(&s->ratelimit)) + return -EBUSY; + + family = s->family; + + if (family == AF_INET) { + addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; + fd = manager_llmnr_ipv4_udp_fd(s->manager); + } else if (family == AF_INET6) { + addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; + fd = manager_llmnr_ipv6_udp_fd(s->manager); + } else + return -EAFNOSUPPORT; + if (fd < 0) + return fd; + + r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, p); + if (r < 0) + return r; + + break; + + case DNS_PROTOCOL_MDNS: + assert(fd < 0); + + if (!ratelimit_test(&s->ratelimit)) + return -EBUSY; + + family = s->family; + + if (family == AF_INET) { + addr.in = MDNS_MULTICAST_IPV4_ADDRESS; + fd = manager_mdns_ipv4_fd(s->manager); + } else if (family == AF_INET6) { + addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; + fd = manager_mdns_ipv6_fd(s->manager); + } else + return -EAFNOSUPPORT; + if (fd < 0) + return fd; + + r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, NULL, p); + if (r < 0) + return r; + + break; + + default: + return -EAFNOSUPPORT; + } + + return 1; +} + +int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { + int r; + + assert(s); + assert(p); + assert(p->protocol == s->protocol); + assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); + + do { + /* If there are multiple linked packets, set the TC bit in all but the last of them */ + if (p->more) { + assert(p->protocol == DNS_PROTOCOL_MDNS); + dns_packet_set_flags(p, true, true); + } + + r = dns_scope_emit_one(s, fd, p); + if (r < 0) + return r; + + p = p->more; + } while (p); + + return 0; +} + +static int dns_scope_socket( + DnsScope *s, + int type, + int family, + const union in_addr_union *address, + DnsServer *server, + uint16_t port) { + + _cleanup_close_ int fd = -1; + union sockaddr_union sa = {}; + socklen_t salen; + static const int one = 1; + int ret, r, ifindex; + + assert(s); + + if (server) { + assert(family == AF_UNSPEC); + assert(!address); + + ifindex = dns_server_ifindex(server); + + sa.sa.sa_family = server->family; + if (server->family == AF_INET) { + sa.in.sin_port = htobe16(port); + sa.in.sin_addr = server->address.in; + salen = sizeof(sa.in); + } else if (server->family == AF_INET6) { + sa.in6.sin6_port = htobe16(port); + sa.in6.sin6_addr = server->address.in6; + sa.in6.sin6_scope_id = ifindex; + salen = sizeof(sa.in6); + } else + return -EAFNOSUPPORT; + } else { + assert(family != AF_UNSPEC); + assert(address); + + sa.sa.sa_family = family; + ifindex = s->link ? s->link->ifindex : 0; + + if (family == AF_INET) { + sa.in.sin_port = htobe16(port); + sa.in.sin_addr = address->in; + salen = sizeof(sa.in); + } else if (family == AF_INET6) { + sa.in6.sin6_port = htobe16(port); + sa.in6.sin6_addr = address->in6; + sa.in6.sin6_scope_id = ifindex; + salen = sizeof(sa.in6); + } else + return -EAFNOSUPPORT; + } + + fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + if (type == SOCK_STREAM) { + r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); + if (r < 0) + return -errno; + } + + if (s->link) { + be32_t ifindex_be = htobe32(ifindex); + + if (sa.sa.sa_family == AF_INET) { + r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); + if (r < 0) + return -errno; + } else if (sa.sa.sa_family == AF_INET6) { + r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); + if (r < 0) + return -errno; + } + } + + if (s->protocol == DNS_PROTOCOL_LLMNR) { + /* RFC 4795, section 2.5 requires the TTL to be set to 1 */ + + if (sa.sa.sa_family == AF_INET) { + r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); + if (r < 0) + return -errno; + } else if (sa.sa.sa_family == AF_INET6) { + r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); + if (r < 0) + return -errno; + } + } + + r = connect(fd, &sa.sa, salen); + if (r < 0 && errno != EINPROGRESS) + return -errno; + + ret = fd; + fd = -1; + + return ret; +} + +int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) { + return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port); +} + +int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) { + return dns_scope_socket(s, SOCK_STREAM, family, address, server, port); +} + +DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) { + DnsSearchDomain *d; + DnsServer *dns_server; + + assert(s); + assert(domain); + + /* Checks if the specified domain is something to look up on + * this scope. Note that this accepts non-qualified hostnames, + * i.e. those without any search path prefixed yet. */ + + if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) + return DNS_SCOPE_NO; + + if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) + return DNS_SCOPE_NO; + + /* Never resolve any loopback hostname or IP address via DNS, + * LLMNR or mDNS. Instead, always rely on synthesized RRs for + * these. */ + if (is_localhost(domain) || + dns_name_endswith(domain, "127.in-addr.arpa") > 0 || + dns_name_equal(domain, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) + return DNS_SCOPE_NO; + + /* Never respond to some of the domains listed in RFC6303 */ + if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || + dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || + dns_name_equal(domain, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) + return DNS_SCOPE_NO; + + /* Never respond to some of the domains listed in RFC6761 */ + if (dns_name_endswith(domain, "invalid") > 0) + return DNS_SCOPE_NO; + + /* Always honour search domains for routing queries. Note that + * we return DNS_SCOPE_YES here, rather than just + * DNS_SCOPE_MAYBE, which means wildcard scopes won't be + * considered anymore. */ + LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) + if (dns_name_endswith(domain, d->name) > 0) + return DNS_SCOPE_YES; + + /* If the DNS server has route-only domains, don't send other requests + * to it. This would be a privacy violation, will most probably fail + * anyway, and adds unnecessary load. */ + dns_server = dns_scope_get_dns_server(s); + if (dns_server && dns_server_limited_domains(dns_server)) + return DNS_SCOPE_NO; + + switch (s->protocol) { + + case DNS_PROTOCOL_DNS: + + /* Exclude link-local IP ranges */ + if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && + dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && + /* If networks use .local in their private setups, they are supposed to also add .local to their search + * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't + * send such queries ordinary DNS servers. */ + dns_name_endswith(domain, "local") == 0) + return DNS_SCOPE_MAYBE; + + return DNS_SCOPE_NO; + + case DNS_PROTOCOL_MDNS: + if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || + (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || + (dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */ + dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */ + manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */ + return DNS_SCOPE_MAYBE; + + return DNS_SCOPE_NO; + + case DNS_PROTOCOL_LLMNR: + if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || + (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || + (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ + !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ + manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ + return DNS_SCOPE_MAYBE; + + return DNS_SCOPE_NO; + + default: + assert_not_reached("Unknown scope protocol"); + } +} + +bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { + int key_family; + + assert(s); + assert(key); + + /* Check if it makes sense to resolve the specified key on + * this scope. Note that this call assumes as fully qualified + * name, i.e. the search suffixes already appended. */ + + if (key->class != DNS_CLASS_IN) + return false; + + if (s->protocol == DNS_PROTOCOL_DNS) { + + /* On classic DNS, looking up non-address RRs is always + * fine. (Specifically, we want to permit looking up + * DNSKEY and DS records on the root and top-level + * domains.) */ + if (!dns_resource_key_is_address(key)) + return true; + + /* However, we refuse to look up A and AAAA RRs on the + * root and single-label domains, under the assumption + * that those should be resolved via LLMNR or search + * path only, and should not be leaked onto the + * internet. */ + return !(dns_name_is_single_label(dns_resource_key_name(key)) || + dns_name_is_root(dns_resource_key_name(key))); + } + + /* On mDNS and LLMNR, send A and AAAA queries only on the + * respective scopes */ + + key_family = dns_type_to_af(key->type); + if (key_family < 0) + return true; + + return key_family == s->family; +} + +static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { + int fd; + + assert(s); + assert(s->link); + + if (s->family == AF_INET) { + struct ip_mreqn mreqn = { + .imr_multiaddr = in, + .imr_ifindex = s->link->ifindex, + }; + + fd = manager_llmnr_ipv4_udp_fd(s->manager); + if (fd < 0) + return fd; + + /* Always first try to drop membership before we add + * one. This is necessary on some devices, such as + * veth. */ + if (b) + (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)); + + if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0) + return -errno; + + } else if (s->family == AF_INET6) { + struct ipv6_mreq mreq = { + .ipv6mr_multiaddr = in6, + .ipv6mr_interface = s->link->ifindex, + }; + + fd = manager_llmnr_ipv6_udp_fd(s->manager); + if (fd < 0) + return fd; + + if (b) + (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); + + if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) + return -errno; + } else + return -EAFNOSUPPORT; + + return 0; +} + +int dns_scope_llmnr_membership(DnsScope *s, bool b) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_LLMNR) + return 0; + + return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); +} + +int dns_scope_mdns_membership(DnsScope *s, bool b) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_MDNS) + return 0; + + return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); +} + +static int dns_scope_make_reply_packet( + DnsScope *s, + uint16_t id, + int rcode, + DnsQuestion *q, + DnsAnswer *answer, + DnsAnswer *soa, + bool tentative, + DnsPacket **ret) { + + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + int r; + + assert(s); + assert(ret); + + if (dns_question_isempty(q) && + dns_answer_isempty(answer) && + dns_answer_isempty(soa)) + return -EINVAL; + + r = dns_packet_new(&p, s->protocol, 0); + if (r < 0) + return r; + + DNS_PACKET_HEADER(p)->id = id; + DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( + 1 /* qr */, + 0 /* opcode */, + 0 /* c */, + 0 /* tc */, + tentative, + 0 /* (ra) */, + 0 /* (ad) */, + 0 /* (cd) */, + rcode)); + + r = dns_packet_append_question(p, q); + if (r < 0) + return r; + DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); + + r = dns_packet_append_answer(p, answer); + if (r < 0) + return r; + DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer)); + + r = dns_packet_append_answer(p, soa); + if (r < 0) + return r; + DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa)); + + *ret = p; + p = NULL; + + return 0; +} + +static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { + DnsResourceRecord *rr; + DnsResourceKey *key; + + assert(s); + assert(p); + + DNS_QUESTION_FOREACH(key, p->question) + dns_zone_verify_conflicts(&s->zone, key); + + DNS_ANSWER_FOREACH(rr, p->answer) + dns_zone_verify_conflicts(&s->zone, rr->key); +} + +void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; + _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; + DnsResourceKey *key = NULL; + bool tentative = false; + int r; + + assert(s); + assert(p); + + if (p->protocol != DNS_PROTOCOL_LLMNR) + return; + + if (p->ipproto == IPPROTO_UDP) { + /* Don't accept UDP queries directed to anything but + * the LLMNR multicast addresses. See RFC 4795, + * section 2.5. */ + + if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) + return; + + if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) + return; + } + + r = dns_packet_extract(p); + if (r < 0) { + log_debug_errno(r, "Failed to extract resource records from incoming packet: %m"); + return; + } + + if (DNS_PACKET_LLMNR_C(p)) { + /* Somebody notified us about a possible conflict */ + dns_scope_verify_conflicts(s, p); + return; + } + + assert(dns_question_size(p->question) == 1); + key = p->question->keys[0]; + + r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative); + if (r < 0) { + log_debug_errno(r, "Failed to lookup key: %m"); + return; + } + if (r == 0) + return; + + if (answer) + dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0); + + r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); + if (r < 0) { + log_debug_errno(r, "Failed to build reply packet: %m"); + return; + } + + if (stream) { + r = dns_stream_write_packet(stream, reply); + if (r < 0) { + log_debug_errno(r, "Failed to enqueue reply packet: %m"); + return; + } + + /* Let's take an extra reference on this stream, so that it stays around after returning. The reference + * will be dangling until the stream is disconnected, and the default completion handler of the stream + * will then unref the stream and destroy it */ + if (DNS_STREAM_QUEUED(stream)) + dns_stream_ref(stream); + } else { + int fd; + + if (!ratelimit_test(&s->ratelimit)) + return; + + if (p->family == AF_INET) + fd = manager_llmnr_ipv4_udp_fd(s->manager); + else if (p->family == AF_INET6) + fd = manager_llmnr_ipv6_udp_fd(s->manager); + else { + log_debug("Unknown protocol"); + return; + } + if (fd < 0) { + log_debug_errno(fd, "Failed to get reply socket: %m"); + return; + } + + /* Note that we always immediately reply to all LLMNR + * requests, and do not wait any time, since we + * verified uniqueness for all records. Also see RFC + * 4795, Section 2.7 */ + + r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply); + if (r < 0) { + log_debug_errno(r, "Failed to send reply packet: %m"); + return; + } + } +} + +DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) { + DnsTransaction *t; + + assert(scope); + assert(key); + + /* Try to find an ongoing transaction that is a equal to the + * specified question */ + t = hashmap_get(scope->transactions_by_key, key); + if (!t) + return NULL; + + /* Refuse reusing transactions that completed based on cached + * data instead of a real packet, if that's requested. */ + if (!cache_ok && + IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && + t->answer_source != DNS_TRANSACTION_NETWORK) + return NULL; + + return t; +} + +static int dns_scope_make_conflict_packet( + DnsScope *s, + DnsResourceRecord *rr, + DnsPacket **ret) { + + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + int r; + + assert(s); + assert(rr); + assert(ret); + + r = dns_packet_new(&p, s->protocol, 0); + if (r < 0) + return r; + + DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( + 0 /* qr */, + 0 /* opcode */, + 1 /* conflict */, + 0 /* tc */, + 0 /* t */, + 0 /* (ra) */, + 0 /* (ad) */, + 0 /* (cd) */, + 0)); + + /* For mDNS, the transaction ID should always be 0 */ + if (s->protocol != DNS_PROTOCOL_MDNS) + random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); + + DNS_PACKET_HEADER(p)->qdcount = htobe16(1); + DNS_PACKET_HEADER(p)->arcount = htobe16(1); + + r = dns_packet_append_key(p, rr->key, NULL); + if (r < 0) + return r; + + r = dns_packet_append_rr(p, rr, NULL, NULL); + if (r < 0) + return r; + + *ret = p; + p = NULL; + + return 0; +} + +static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata) { + DnsScope *scope = userdata; + int r; + + assert(es); + assert(scope); + + scope->conflict_event_source = sd_event_source_unref(scope->conflict_event_source); + + for (;;) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + + rr = ordered_hashmap_steal_first(scope->conflict_queue); + if (!rr) + break; + + r = dns_scope_make_conflict_packet(scope, rr, &p); + if (r < 0) { + log_error_errno(r, "Failed to make conflict packet: %m"); + return 0; + } + + r = dns_scope_emit_udp(scope, -1, p); + if (r < 0) + log_debug_errno(r, "Failed to send conflict packet: %m"); + } + + return 0; +} + +int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) { + usec_t jitter; + int r; + + assert(scope); + assert(rr); + + /* We don't send these queries immediately. Instead, we queue + * them, and send them after some jitter delay. */ + r = ordered_hashmap_ensure_allocated(&scope->conflict_queue, &dns_resource_key_hash_ops); + if (r < 0) { + log_oom(); + return r; + } + + /* We only place one RR per key in the conflict + * messages, not all of them. That should be enough to + * indicate where there might be a conflict */ + r = ordered_hashmap_put(scope->conflict_queue, rr->key, rr); + if (r == -EEXIST || r == 0) + return 0; + if (r < 0) + return log_debug_errno(r, "Failed to queue conflicting RR: %m"); + + dns_resource_record_ref(rr); + + if (scope->conflict_event_source) + return 0; + + random_bytes(&jitter, sizeof(jitter)); + jitter %= LLMNR_JITTER_INTERVAL_USEC; + + r = sd_event_add_time(scope->manager->event, + &scope->conflict_event_source, + clock_boottime_or_monotonic(), + now(clock_boottime_or_monotonic()) + jitter, + LLMNR_JITTER_INTERVAL_USEC, + on_conflict_dispatch, scope); + if (r < 0) + return log_debug_errno(r, "Failed to add conflict dispatch event: %m"); + + (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict"); + + return 0; +} + +void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) { + unsigned i; + int r; + + assert(scope); + assert(p); + + if (p->protocol != DNS_PROTOCOL_LLMNR) + return; + + if (DNS_PACKET_RRCOUNT(p) <= 0) + return; + + if (DNS_PACKET_LLMNR_C(p) != 0) + return; + + if (DNS_PACKET_LLMNR_T(p) != 0) + return; + + if (manager_our_packet(scope->manager, p)) + return; + + r = dns_packet_extract(p); + if (r < 0) { + log_debug_errno(r, "Failed to extract packet: %m"); + return; + } + + log_debug("Checking for conflicts..."); + + for (i = 0; i < p->answer->n_rrs; i++) { + + /* Check for conflicts against the local zone. If we + * found one, we won't check any further */ + r = dns_zone_check_conflicts(&scope->zone, p->answer->items[i].rr); + if (r != 0) + continue; + + /* Check for conflicts against the local cache. If so, + * send out an advisory query, to inform everybody */ + r = dns_cache_check_conflicts(&scope->cache, p->answer->items[i].rr, p->family, &p->sender); + if (r <= 0) + continue; + + dns_scope_notify_conflict(scope, p->answer->items[i].rr); + } +} + +void dns_scope_dump(DnsScope *s, FILE *f) { + assert(s); + + if (!f) + f = stdout; + + fputs("[Scope protocol=", f); + fputs(dns_protocol_to_string(s->protocol), f); + + if (s->link) { + fputs(" interface=", f); + fputs(s->link->name, f); + } + + if (s->family != AF_UNSPEC) { + fputs(" family=", f); + fputs(af_to_name(s->family), f); + } + + fputs("]\n", f); + + if (!dns_zone_is_empty(&s->zone)) { + fputs("ZONE:\n", f); + dns_zone_dump(&s->zone, f); + } + + if (!dns_cache_is_empty(&s->cache)) { + fputs("CACHE:\n", f); + dns_cache_dump(&s->cache, f); + } +} + +DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return NULL; + + if (s->link) + return s->link->search_domains; + + return s->manager->search_domains; +} + +bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return false; + + return dns_name_is_single_label(name); +} + +bool dns_scope_network_good(DnsScope *s) { + /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes + * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global + * DNS scope we check whether there are any links that are up and have an address. */ + + if (s->link) + return true; + + return manager_routable(s->manager, AF_UNSPEC); +} + +int dns_scope_ifindex(DnsScope *s) { + assert(s); + + if (s->link) + return s->link->ifindex; + + return 0; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-scope.h b/src/grp-resolve/systemd-resolved/resolved-dns-scope.h new file mode 100644 index 0000000000..26623b1878 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-scope.h @@ -0,0 +1,114 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-dnssec.h" +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/list.h" + +typedef struct DnsScope DnsScope; + +#include "resolved-dns-cache.h" +#include "resolved-dns-query.h" +#include "resolved-dns-search-domain.h" +#include "resolved-dns-server.h" +#include "resolved-dns-stream.h" +#include "resolved-dns-zone.h" +#include "resolved-link.h" + +typedef enum DnsScopeMatch { + DNS_SCOPE_NO, + DNS_SCOPE_MAYBE, + DNS_SCOPE_YES, + _DNS_SCOPE_MATCH_MAX, + _DNS_SCOPE_INVALID = -1 +} DnsScopeMatch; + +struct DnsScope { + Manager *manager; + + DnsProtocol protocol; + int family; + DnssecMode dnssec_mode; + + Link *link; + + DnsCache cache; + DnsZone zone; + + OrderedHashmap *conflict_queue; + sd_event_source *conflict_event_source; + + RateLimit ratelimit; + + usec_t resend_timeout; + usec_t max_rtt; + + LIST_HEAD(DnsQueryCandidate, query_candidates); + + /* Note that we keep track of ongoing transactions in two + * ways: once in a hashmap, indexed by the rr key, and once in + * a linked list. We use the hashmap to quickly find + * transactions we can reuse for a key. But note that there + * might be multiple transactions for the same key (because + * the zone probing can't reuse a transaction answered from + * the zone or the cache), and the hashmap only tracks the + * most recent entry. */ + Hashmap *transactions_by_key; + LIST_HEAD(DnsTransaction, transactions); + + LIST_FIELDS(DnsScope, scopes); +}; + +int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol p, int family); +DnsScope* dns_scope_free(DnsScope *s); + +void dns_scope_packet_received(DnsScope *s, usec_t rtt); +void dns_scope_packet_lost(DnsScope *s, usec_t usec); + +int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p); +int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port); +int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port); + +DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain); +bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key); + +DnsServer *dns_scope_get_dns_server(DnsScope *s); +void dns_scope_next_dns_server(DnsScope *s); + +int dns_scope_llmnr_membership(DnsScope *s, bool b); +int dns_scope_mdns_membership(DnsScope *s, bool b); + +void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p); + +DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok); + +int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr); +void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p); + +void dns_scope_dump(DnsScope *s, FILE *f); + +DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s); + +bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name); + +bool dns_scope_network_good(DnsScope *s); + +int dns_scope_ifindex(DnsScope *s); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.c b/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.c new file mode 100644 index 0000000000..a82df4c7a6 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.c @@ -0,0 +1,226 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/alloc-util.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-search-domain.h" + +int dns_search_domain_new( + Manager *m, + DnsSearchDomain **ret, + DnsSearchDomainType type, + Link *l, + const char *name) { + + _cleanup_free_ char *normalized = NULL; + DnsSearchDomain *d; + int r; + + assert(m); + assert((type == DNS_SEARCH_DOMAIN_LINK) == !!l); + assert(name); + + r = dns_name_normalize(name, &normalized); + if (r < 0) + return r; + + if (l) { + if (l->n_search_domains >= LINK_SEARCH_DOMAINS_MAX) + return -E2BIG; + } else { + if (m->n_search_domains >= MANAGER_SEARCH_DOMAINS_MAX) + return -E2BIG; + } + + d = new0(DnsSearchDomain, 1); + if (!d) + return -ENOMEM; + + d->n_ref = 1; + d->manager = m; + d->type = type; + d->name = normalized; + normalized = NULL; + + switch (type) { + + case DNS_SEARCH_DOMAIN_LINK: + d->link = l; + LIST_APPEND(domains, l->search_domains, d); + l->n_search_domains++; + break; + + case DNS_SERVER_SYSTEM: + LIST_APPEND(domains, m->search_domains, d); + m->n_search_domains++; + break; + + default: + assert_not_reached("Unknown search domain type"); + } + + d->linked = true; + + if (ret) + *ret = d; + + return 0; +} + +DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d) { + if (!d) + return NULL; + + assert(d->n_ref > 0); + d->n_ref++; + + return d; +} + +DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d) { + if (!d) + return NULL; + + assert(d->n_ref > 0); + d->n_ref--; + + if (d->n_ref > 0) + return NULL; + + free(d->name); + return mfree(d); +} + +void dns_search_domain_unlink(DnsSearchDomain *d) { + assert(d); + assert(d->manager); + + if (!d->linked) + return; + + switch (d->type) { + + case DNS_SEARCH_DOMAIN_LINK: + assert(d->link); + assert(d->link->n_search_domains > 0); + LIST_REMOVE(domains, d->link->search_domains, d); + d->link->n_search_domains--; + break; + + case DNS_SEARCH_DOMAIN_SYSTEM: + assert(d->manager->n_search_domains > 0); + LIST_REMOVE(domains, d->manager->search_domains, d); + d->manager->n_search_domains--; + break; + } + + d->linked = false; + + dns_search_domain_unref(d); +} + +void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d) { + DnsSearchDomain *tail; + + assert(d); + + if (!d->marked) + return; + + d->marked = false; + + if (!d->linked || !d->domains_next) + return; + + switch (d->type) { + + case DNS_SEARCH_DOMAIN_LINK: + assert(d->link); + LIST_FIND_TAIL(domains, d, tail); + LIST_REMOVE(domains, d->link->search_domains, d); + LIST_INSERT_AFTER(domains, d->link->search_domains, tail, d); + break; + + case DNS_SEARCH_DOMAIN_SYSTEM: + LIST_FIND_TAIL(domains, d, tail); + LIST_REMOVE(domains, d->manager->search_domains, d); + LIST_INSERT_AFTER(domains, d->manager->search_domains, tail, d); + break; + + default: + assert_not_reached("Unknown search domain type"); + } +} + +void dns_search_domain_unlink_all(DnsSearchDomain *first) { + DnsSearchDomain *next; + + if (!first) + return; + + next = first->domains_next; + dns_search_domain_unlink(first); + + dns_search_domain_unlink_all(next); +} + +void dns_search_domain_unlink_marked(DnsSearchDomain *first) { + DnsSearchDomain *next; + + if (!first) + return; + + next = first->domains_next; + + if (first->marked) + dns_search_domain_unlink(first); + + dns_search_domain_unlink_marked(next); +} + +void dns_search_domain_mark_all(DnsSearchDomain *first) { + if (!first) + return; + + first->marked = true; + dns_search_domain_mark_all(first->domains_next); +} + +int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret) { + DnsSearchDomain *d; + int r; + + assert(name); + assert(ret); + + LIST_FOREACH(domains, d, first) { + + r = dns_name_equal(name, d->name); + if (r < 0) + return r; + if (r > 0) { + *ret = d; + return 1; + } + } + + *ret = NULL; + return 0; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.h b/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.h new file mode 100644 index 0000000000..53b4f3207a --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-search-domain.h @@ -0,0 +1,74 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/macro.h" + +typedef struct DnsSearchDomain DnsSearchDomain; + +typedef enum DnsSearchDomainType { + DNS_SEARCH_DOMAIN_SYSTEM, + DNS_SEARCH_DOMAIN_LINK, +} DnsSearchDomainType; + +#include "resolved-link.h" +#include "resolved-manager.h" + +struct DnsSearchDomain { + Manager *manager; + + unsigned n_ref; + + DnsSearchDomainType type; + Link *link; + + char *name; + + bool marked:1; + bool route_only:1; + + bool linked:1; + LIST_FIELDS(DnsSearchDomain, domains); +}; + +int dns_search_domain_new( + Manager *m, + DnsSearchDomain **ret, + DnsSearchDomainType type, + Link *link, + const char *name); + +DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d); +DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d); + +void dns_search_domain_unlink(DnsSearchDomain *d); +void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d); + +void dns_search_domain_unlink_all(DnsSearchDomain *first); +void dns_search_domain_unlink_marked(DnsSearchDomain *first); +void dns_search_domain_mark_all(DnsSearchDomain *first); + +int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret); + +static inline const char* DNS_SEARCH_DOMAIN_NAME(DnsSearchDomain *d) { + return d ? d->name : NULL; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsSearchDomain*, dns_search_domain_unref); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-server.c b/src/grp-resolve/systemd-resolved/resolved-dns-server.c new file mode 100644 index 0000000000..b2605c0d46 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-server.c @@ -0,0 +1,797 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-messages.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/siphash24.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" + +#include "resolved-dns-server.h" +#include "resolved-dns-stub.h" +#include "resolved-resolv-conf.h" + +/* After how much time to repeat classic DNS requests */ +#define DNS_TIMEOUT_MIN_USEC (500 * USEC_PER_MSEC) +#define DNS_TIMEOUT_MAX_USEC (5 * USEC_PER_SEC) + +/* The amount of time to wait before retrying with a full feature set */ +#define DNS_SERVER_FEATURE_GRACE_PERIOD_MAX_USEC (6 * USEC_PER_HOUR) +#define DNS_SERVER_FEATURE_GRACE_PERIOD_MIN_USEC (5 * USEC_PER_MINUTE) + +/* The number of times we will attempt a certain feature set before degrading */ +#define DNS_SERVER_FEATURE_RETRY_ATTEMPTS 3 + +int dns_server_new( + Manager *m, + DnsServer **ret, + DnsServerType type, + Link *l, + int family, + const union in_addr_union *in_addr, + int ifindex) { + + DnsServer *s; + + assert(m); + assert((type == DNS_SERVER_LINK) == !!l); + assert(in_addr); + + if (!IN_SET(family, AF_INET, AF_INET6)) + return -EAFNOSUPPORT; + + if (l) { + if (l->n_dns_servers >= LINK_DNS_SERVERS_MAX) + return -E2BIG; + } else { + if (m->n_dns_servers >= MANAGER_DNS_SERVERS_MAX) + return -E2BIG; + } + + s = new0(DnsServer, 1); + if (!s) + return -ENOMEM; + + s->n_ref = 1; + s->manager = m; + s->verified_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_BEST; + s->features_grace_period_usec = DNS_SERVER_FEATURE_GRACE_PERIOD_MIN_USEC; + s->received_udp_packet_max = DNS_PACKET_UNICAST_SIZE_MAX; + s->type = type; + s->family = family; + s->address = *in_addr; + s->ifindex = ifindex; + s->resend_timeout = DNS_TIMEOUT_MIN_USEC; + + switch (type) { + + case DNS_SERVER_LINK: + s->link = l; + LIST_APPEND(servers, l->dns_servers, s); + l->n_dns_servers++; + break; + + case DNS_SERVER_SYSTEM: + LIST_APPEND(servers, m->dns_servers, s); + m->n_dns_servers++; + break; + + case DNS_SERVER_FALLBACK: + LIST_APPEND(servers, m->fallback_dns_servers, s); + m->n_dns_servers++; + break; + + default: + assert_not_reached("Unknown server type"); + } + + s->linked = true; + + /* A new DNS server that isn't fallback is added and the one + * we used so far was a fallback one? Then let's try to pick + * the new one */ + if (type != DNS_SERVER_FALLBACK && + m->current_dns_server && + m->current_dns_server->type == DNS_SERVER_FALLBACK) + manager_set_dns_server(m, NULL); + + if (ret) + *ret = s; + + return 0; +} + +DnsServer* dns_server_ref(DnsServer *s) { + if (!s) + return NULL; + + assert(s->n_ref > 0); + s->n_ref++; + + return s; +} + +DnsServer* dns_server_unref(DnsServer *s) { + if (!s) + return NULL; + + assert(s->n_ref > 0); + s->n_ref--; + + if (s->n_ref > 0) + return NULL; + + free(s->server_string); + return mfree(s); +} + +void dns_server_unlink(DnsServer *s) { + assert(s); + assert(s->manager); + + /* This removes the specified server from the linked list of + * servers, but any server might still stay around if it has + * refs, for example from an ongoing transaction. */ + + if (!s->linked) + return; + + switch (s->type) { + + case DNS_SERVER_LINK: + assert(s->link); + assert(s->link->n_dns_servers > 0); + LIST_REMOVE(servers, s->link->dns_servers, s); + s->link->n_dns_servers--; + break; + + case DNS_SERVER_SYSTEM: + assert(s->manager->n_dns_servers > 0); + LIST_REMOVE(servers, s->manager->dns_servers, s); + s->manager->n_dns_servers--; + break; + + case DNS_SERVER_FALLBACK: + assert(s->manager->n_dns_servers > 0); + LIST_REMOVE(servers, s->manager->fallback_dns_servers, s); + s->manager->n_dns_servers--; + break; + } + + s->linked = false; + + if (s->link && s->link->current_dns_server == s) + link_set_dns_server(s->link, NULL); + + if (s->manager->current_dns_server == s) + manager_set_dns_server(s->manager, NULL); + + dns_server_unref(s); +} + +void dns_server_move_back_and_unmark(DnsServer *s) { + DnsServer *tail; + + assert(s); + + if (!s->marked) + return; + + s->marked = false; + + if (!s->linked || !s->servers_next) + return; + + /* Move us to the end of the list, so that the order is + * strictly kept, if we are not at the end anyway. */ + + switch (s->type) { + + case DNS_SERVER_LINK: + assert(s->link); + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->link->dns_servers, s); + LIST_INSERT_AFTER(servers, s->link->dns_servers, tail, s); + break; + + case DNS_SERVER_SYSTEM: + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->manager->dns_servers, s); + LIST_INSERT_AFTER(servers, s->manager->dns_servers, tail, s); + break; + + case DNS_SERVER_FALLBACK: + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->manager->fallback_dns_servers, s); + LIST_INSERT_AFTER(servers, s->manager->fallback_dns_servers, tail, s); + break; + + default: + assert_not_reached("Unknown server type"); + } +} + +static void dns_server_verified(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + if (s->verified_feature_level > level) + return; + + if (s->verified_feature_level != level) { + log_debug("Verified we get a response at feature level %s from DNS server %s.", + dns_server_feature_level_to_string(level), + dns_server_string(s)); + s->verified_feature_level = level; + } + + assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &s->verified_usec) >= 0); +} + +static void dns_server_reset_counters(DnsServer *s) { + assert(s); + + s->n_failed_udp = 0; + s->n_failed_tcp = 0; + s->packet_truncated = false; + s->verified_usec = 0; + + /* Note that we do not reset s->packet_bad_opt and s->packet_rrsig_missing here. We reset them only when the + * grace period ends, but not when lowering the possible feature level, as a lower level feature level should + * not make RRSIGs appear or OPT appear, but rather make them disappear. If the reappear anyway, then that's + * indication for a differently broken OPT/RRSIG implementation, and we really don't want to support that + * either. + * + * This is particularly important to deal with certain Belkin routers which break OPT for certain lookups (A), + * but pass traffic through for others (AAAA). If we detect the broken behaviour on one lookup we should not + * reenable it for another, because we cannot validate things anyway, given that the RRSIG/OPT data will be + * incomplete. */ +} + +void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t rtt, size_t size) { + assert(s); + + if (protocol == IPPROTO_UDP) { + if (s->possible_feature_level == level) + s->n_failed_udp = 0; + + /* If the RRSIG data is missing, then we can only validate EDNS0 at max */ + if (s->packet_rrsig_missing && level >= DNS_SERVER_FEATURE_LEVEL_DO) + level = DNS_SERVER_FEATURE_LEVEL_DO - 1; + + /* If the OPT RR got lost, then we can only validate UDP at max */ + if (s->packet_bad_opt && level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) + level = DNS_SERVER_FEATURE_LEVEL_EDNS0 - 1; + + /* Even if we successfully receive a reply to a request announcing support for large packets, + that does not mean we can necessarily receive large packets. */ + if (level == DNS_SERVER_FEATURE_LEVEL_LARGE) + level = DNS_SERVER_FEATURE_LEVEL_LARGE - 1; + + } else if (protocol == IPPROTO_TCP) { + + if (s->possible_feature_level == level) + s->n_failed_tcp = 0; + + /* Successful TCP connections are only useful to verify the TCP feature level. */ + level = DNS_SERVER_FEATURE_LEVEL_TCP; + } + + dns_server_verified(s, level); + + /* Remember the size of the largest UDP packet we received from a server, + we know that we can always announce support for packets with at least + this size. */ + if (protocol == IPPROTO_UDP && s->received_udp_packet_max < size) + s->received_udp_packet_max = size; + + if (s->max_rtt < rtt) { + s->max_rtt = rtt; + s->resend_timeout = CLAMP(s->max_rtt * 2, DNS_TIMEOUT_MIN_USEC, DNS_TIMEOUT_MAX_USEC); + } +} + +void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t usec) { + assert(s); + assert(s->manager); + + if (s->possible_feature_level == level) { + if (protocol == IPPROTO_UDP) + s->n_failed_udp++; + else if (protocol == IPPROTO_TCP) + s->n_failed_tcp++; + } + + if (s->resend_timeout > usec) + return; + + s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC); +} + +void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + /* Invoked whenever we get a packet with TC bit set. */ + + if (s->possible_feature_level != level) + return; + + s->packet_truncated = true; +} + +void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + if (level < DNS_SERVER_FEATURE_LEVEL_DO) + return; + + /* If the RRSIG RRs are missing, we have to downgrade what we previously verified */ + if (s->verified_feature_level >= DNS_SERVER_FEATURE_LEVEL_DO) + s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_DO-1; + + s->packet_rrsig_missing = true; +} + +void dns_server_packet_bad_opt(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + if (level < DNS_SERVER_FEATURE_LEVEL_EDNS0) + return; + + /* If the OPT RR got lost, we have to downgrade what we previously verified */ + if (s->verified_feature_level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) + s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_EDNS0-1; + + s->packet_bad_opt = true; +} + +void dns_server_packet_rcode_downgrade(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + /* Invoked whenever we got a FORMERR, SERVFAIL or NOTIMP rcode from a server and downgrading the feature level + * for the transaction made it go away. In this case we immediately downgrade to the feature level that made + * things work. */ + + if (s->verified_feature_level > level) + s->verified_feature_level = level; + + if (s->possible_feature_level > level) { + s->possible_feature_level = level; + dns_server_reset_counters(s); + } + + log_debug("Downgrading transaction feature level fixed an RCODE error, downgrading server %s too.", dns_server_string(s)); +} + +static bool dns_server_grace_period_expired(DnsServer *s) { + usec_t ts; + + assert(s); + assert(s->manager); + + if (s->verified_usec == 0) + return false; + + assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + if (s->verified_usec + s->features_grace_period_usec > ts) + return false; + + s->features_grace_period_usec = MIN(s->features_grace_period_usec * 2, DNS_SERVER_FEATURE_GRACE_PERIOD_MAX_USEC); + + return true; +} + +DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) { + assert(s); + + if (s->possible_feature_level != DNS_SERVER_FEATURE_LEVEL_BEST && + dns_server_grace_period_expired(s)) { + + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_BEST; + + dns_server_reset_counters(s); + + s->packet_bad_opt = false; + s->packet_rrsig_missing = false; + + log_info("Grace period over, resuming full feature set (%s) for DNS server %s.", + dns_server_feature_level_to_string(s->possible_feature_level), + dns_server_string(s)); + + } else if (s->possible_feature_level <= s->verified_feature_level) + s->possible_feature_level = s->verified_feature_level; + else { + DnsServerFeatureLevel p = s->possible_feature_level; + + if (s->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->possible_feature_level == DNS_SERVER_FEATURE_LEVEL_TCP) { + + /* We are at the TCP (lowest) level, and we tried a couple of TCP connections, and it didn't + * work. Upgrade back to UDP again. */ + log_debug("Reached maximum number of failed TCP connection attempts, trying UDP again..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_UDP; + + } else if (s->packet_bad_opt && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) { + + /* A reply to one of our EDNS0 queries didn't carry a valid OPT RR, then downgrade to below + * EDNS0 levels. After all, some records generate different responses with and without OPT RR + * in the request. Example: + * https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ + + log_debug("Server doesn't support EDNS(0) properly, downgrading feature level..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_UDP; + + } else if (s->packet_rrsig_missing && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_DO) { + + /* RRSIG data was missing on a EDNS0 packet with DO bit set. This means the server doesn't + * augment responses with DNSSEC RRs. If so, let's better not ask the server for it anymore, + * after all some servers generate different replies depending if an OPT RR is in the query or + * not. */ + + log_debug("Detected server responses lack RRSIG records, downgrading feature level..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_EDNS0; + + } else if (s->n_failed_udp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_UDP) { + + /* We lost too many UDP packets in a row, and are on a feature level of UDP or higher. If the + * packets are lost, maybe the server cannot parse them, hence downgrading sounds like a good + * idea. We might downgrade all the way down to TCP this way. */ + + log_debug("Lost too many UDP packets, downgrading feature level..."); + s->possible_feature_level--; + + } else if (s->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->packet_truncated && + s->possible_feature_level > DNS_SERVER_FEATURE_LEVEL_UDP) { + + /* We got too many TCP connection failures in a row, we had at least one truncated packet, and + * are on a feature level above UDP. By downgrading things and getting rid of DNSSEC or EDNS0 + * data we hope to make the packet smaller, so that it still works via UDP given that TCP + * appears not to be a fallback. Note that if we are already at the lowest UDP level, we don't + * go further down, since that's TCP, and TCP failed too often after all. */ + + log_debug("Got too many failed TCP connection failures and truncated UDP packets, downgrading feature level..."); + s->possible_feature_level--; + } + + if (p != s->possible_feature_level) { + + /* We changed the feature level, reset the counting */ + dns_server_reset_counters(s); + + log_warning("Using degraded feature set (%s) for DNS server %s.", + dns_server_feature_level_to_string(s->possible_feature_level), + dns_server_string(s)); + } + } + + return s->possible_feature_level; +} + +int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level) { + size_t packet_size; + bool edns_do; + int r; + + assert(server); + assert(packet); + assert(packet->protocol == DNS_PROTOCOL_DNS); + + /* Fix the OPT field in the packet to match our current feature level. */ + + r = dns_packet_truncate_opt(packet); + if (r < 0) + return r; + + if (level < DNS_SERVER_FEATURE_LEVEL_EDNS0) + return 0; + + edns_do = level >= DNS_SERVER_FEATURE_LEVEL_DO; + + if (level >= DNS_SERVER_FEATURE_LEVEL_LARGE) + packet_size = DNS_PACKET_UNICAST_SIZE_LARGE_MAX; + else + packet_size = server->received_udp_packet_max; + + return dns_packet_append_opt(packet, packet_size, edns_do, 0, NULL); +} + +int dns_server_ifindex(const DnsServer *s) { + assert(s); + + /* The link ifindex always takes precedence */ + if (s->link) + return s->link->ifindex; + + if (s->ifindex > 0) + return s->ifindex; + + return 0; +} + +const char *dns_server_string(DnsServer *server) { + assert(server); + + if (!server->server_string) + (void) in_addr_ifindex_to_string(server->family, &server->address, dns_server_ifindex(server), &server->server_string); + + return strna(server->server_string); +} + +bool dns_server_dnssec_supported(DnsServer *server) { + assert(server); + + /* Returns whether the server supports DNSSEC according to what we know about it */ + + if (server->possible_feature_level < DNS_SERVER_FEATURE_LEVEL_DO) + return false; + + if (server->packet_bad_opt) + return false; + + if (server->packet_rrsig_missing) + return false; + + /* DNSSEC servers need to support TCP properly (see RFC5966), if they don't, we assume DNSSEC is borked too */ + if (server->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS) + return false; + + return true; +} + +void dns_server_warn_downgrade(DnsServer *server) { + assert(server); + + if (server->warned_downgrade) + return; + + log_struct(LOG_NOTICE, + LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_DOWNGRADE), + LOG_MESSAGE("Server %s does not support DNSSEC, downgrading to non-DNSSEC mode.", dns_server_string(server)), + "DNS_SERVER=%s", dns_server_string(server), + "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(server->possible_feature_level), + NULL); + + server->warned_downgrade = true; +} + +bool dns_server_limited_domains(DnsServer *server) { + DnsSearchDomain *domain; + bool domain_restricted = false; + + /* Check if the server has route-only domains without ~., i. e. whether + * it should only be used for particular domains */ + if (!server->link) + return false; + + LIST_FOREACH(domains, domain, server->link->search_domains) + if (domain->route_only) { + domain_restricted = true; + /* ~. means "any domain", thus it is a global server */ + if (dns_name_is_root(DNS_SEARCH_DOMAIN_NAME(domain))) + return false; + } + + return domain_restricted; +} + +static void dns_server_hash_func(const void *p, struct siphash *state) { + const DnsServer *s = p; + + assert(s); + + siphash24_compress(&s->family, sizeof(s->family), state); + siphash24_compress(&s->address, FAMILY_ADDRESS_SIZE(s->family), state); + siphash24_compress(&s->ifindex, sizeof(s->ifindex), state); +} + +static int dns_server_compare_func(const void *a, const void *b) { + const DnsServer *x = a, *y = b; + int r; + + if (x->family < y->family) + return -1; + if (x->family > y->family) + return 1; + + r = memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family)); + if (r != 0) + return r; + + if (x->ifindex < y->ifindex) + return -1; + if (x->ifindex > y->ifindex) + return 1; + + return 0; +} + +const struct hash_ops dns_server_hash_ops = { + .hash = dns_server_hash_func, + .compare = dns_server_compare_func +}; + +void dns_server_unlink_all(DnsServer *first) { + DnsServer *next; + + if (!first) + return; + + next = first->servers_next; + dns_server_unlink(first); + + dns_server_unlink_all(next); +} + +void dns_server_unlink_marked(DnsServer *first) { + DnsServer *next; + + if (!first) + return; + + next = first->servers_next; + + if (first->marked) + dns_server_unlink(first); + + dns_server_unlink_marked(next); +} + +void dns_server_mark_all(DnsServer *first) { + if (!first) + return; + + first->marked = true; + dns_server_mark_all(first->servers_next); +} + +DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr, int ifindex) { + DnsServer *s; + + LIST_FOREACH(servers, s, first) + if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0 && s->ifindex == ifindex) + return s; + + return NULL; +} + +DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t) { + assert(m); + + switch (t) { + + case DNS_SERVER_SYSTEM: + return m->dns_servers; + + case DNS_SERVER_FALLBACK: + return m->fallback_dns_servers; + + default: + return NULL; + } +} + +DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) { + assert(m); + + if (m->current_dns_server == s) + return s; + + if (s) + log_info("Switching to %s DNS server %s.", + dns_server_type_to_string(s->type), + dns_server_string(s)); + + dns_server_unref(m->current_dns_server); + m->current_dns_server = dns_server_ref(s); + + if (m->unicast_scope) + dns_cache_flush(&m->unicast_scope->cache); + + return s; +} + +DnsServer *manager_get_dns_server(Manager *m) { + Link *l; + assert(m); + + /* Try to read updates resolv.conf */ + manager_read_resolv_conf(m); + + /* If no DNS server was chosen so far, pick the first one */ + if (!m->current_dns_server) + manager_set_dns_server(m, m->dns_servers); + + if (!m->current_dns_server) { + bool found = false; + Iterator i; + + /* No DNS servers configured, let's see if there are + * any on any links. If not, we use the fallback + * servers */ + + HASHMAP_FOREACH(l, m->links, i) + if (l->dns_servers) { + found = true; + break; + } + + if (!found) + manager_set_dns_server(m, m->fallback_dns_servers); + } + + return m->current_dns_server; +} + +void manager_next_dns_server(Manager *m) { + assert(m); + + /* If there's currently no DNS server set, then the next + * manager_get_dns_server() will find one */ + if (!m->current_dns_server) + return; + + /* Change to the next one, but make sure to follow the linked + * list only if the server is still linked. */ + if (m->current_dns_server->linked && m->current_dns_server->servers_next) { + manager_set_dns_server(m, m->current_dns_server->servers_next); + return; + } + + /* If there was no next one, then start from the beginning of + * the list */ + if (m->current_dns_server->type == DNS_SERVER_FALLBACK) + manager_set_dns_server(m, m->fallback_dns_servers); + else + manager_set_dns_server(m, m->dns_servers); +} + +bool dns_server_address_valid(int family, const union in_addr_union *sa) { + + /* Refuses the 0 IP addresses as well as 127.0.0.53 (which is our own DNS stub) */ + + if (in_addr_is_null(family, sa)) + return false; + + if (family == AF_INET && sa->in.s_addr == htobe32(INADDR_DNS_STUB)) + return false; + + return true; +} + +static const char* const dns_server_type_table[_DNS_SERVER_TYPE_MAX] = { + [DNS_SERVER_SYSTEM] = "system", + [DNS_SERVER_FALLBACK] = "fallback", + [DNS_SERVER_LINK] = "link", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_server_type, DnsServerType); + +static const char* const dns_server_feature_level_table[_DNS_SERVER_FEATURE_LEVEL_MAX] = { + [DNS_SERVER_FEATURE_LEVEL_TCP] = "TCP", + [DNS_SERVER_FEATURE_LEVEL_UDP] = "UDP", + [DNS_SERVER_FEATURE_LEVEL_EDNS0] = "UDP+EDNS0", + [DNS_SERVER_FEATURE_LEVEL_DO] = "UDP+EDNS0+DO", + [DNS_SERVER_FEATURE_LEVEL_LARGE] = "UDP+EDNS0+DO+LARGE", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_server_feature_level, DnsServerFeatureLevel); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-server.h b/src/grp-resolve/systemd-resolved/resolved-dns-server.h new file mode 100644 index 0000000000..cb0ad80292 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-server.h @@ -0,0 +1,149 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/in-addr-util.h" + +typedef struct DnsServer DnsServer; + +typedef enum DnsServerType { + DNS_SERVER_SYSTEM, + DNS_SERVER_FALLBACK, + DNS_SERVER_LINK, +} DnsServerType; +#define _DNS_SERVER_TYPE_MAX (DNS_SERVER_LINK + 1) + +const char* dns_server_type_to_string(DnsServerType i) _const_; +DnsServerType dns_server_type_from_string(const char *s) _pure_; + +typedef enum DnsServerFeatureLevel { + DNS_SERVER_FEATURE_LEVEL_TCP, + DNS_SERVER_FEATURE_LEVEL_UDP, + DNS_SERVER_FEATURE_LEVEL_EDNS0, + DNS_SERVER_FEATURE_LEVEL_DO, + DNS_SERVER_FEATURE_LEVEL_LARGE, + _DNS_SERVER_FEATURE_LEVEL_MAX, + _DNS_SERVER_FEATURE_LEVEL_INVALID = -1 +} DnsServerFeatureLevel; + +#define DNS_SERVER_FEATURE_LEVEL_WORST 0 +#define DNS_SERVER_FEATURE_LEVEL_BEST (_DNS_SERVER_FEATURE_LEVEL_MAX - 1) + +const char* dns_server_feature_level_to_string(int i) _const_; +int dns_server_feature_level_from_string(const char *s) _pure_; + +#include "resolved-link.h" +#include "resolved-manager.h" + +struct DnsServer { + Manager *manager; + + unsigned n_ref; + + DnsServerType type; + Link *link; + + int family; + union in_addr_union address; + int ifindex; /* for IPv6 link-local DNS servers */ + + char *server_string; + + usec_t resend_timeout; + usec_t max_rtt; + + DnsServerFeatureLevel verified_feature_level; + DnsServerFeatureLevel possible_feature_level; + + size_t received_udp_packet_max; + + unsigned n_failed_udp; + unsigned n_failed_tcp; + + bool packet_truncated:1; + bool packet_bad_opt:1; + bool packet_rrsig_missing:1; + + usec_t verified_usec; + usec_t features_grace_period_usec; + + /* Whether we already warned about downgrading to non-DNSSEC mode for this server */ + bool warned_downgrade:1; + + /* Used when GC'ing old DNS servers when configuration changes. */ + bool marked:1; + + /* If linked is set, then this server appears in the servers linked list */ + bool linked:1; + LIST_FIELDS(DnsServer, servers); +}; + +int dns_server_new( + Manager *m, + DnsServer **ret, + DnsServerType type, + Link *link, + int family, + const union in_addr_union *address, + int ifindex); + +DnsServer* dns_server_ref(DnsServer *s); +DnsServer* dns_server_unref(DnsServer *s); + +void dns_server_unlink(DnsServer *s); +void dns_server_move_back_and_unmark(DnsServer *s); + +void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t rtt, size_t size); +void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t usec); +void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_bad_opt(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_rcode_downgrade(DnsServer *s, DnsServerFeatureLevel level); + +DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s); + +int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level); + +const char *dns_server_string(DnsServer *server); +int dns_server_ifindex(const DnsServer *s); + +bool dns_server_dnssec_supported(DnsServer *server); + +void dns_server_warn_downgrade(DnsServer *server); + +bool dns_server_limited_domains(DnsServer *server); + +DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr, int ifindex); + +void dns_server_unlink_all(DnsServer *first); +void dns_server_unlink_marked(DnsServer *first); +void dns_server_mark_all(DnsServer *first); + +DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t); + +DnsServer *manager_set_dns_server(Manager *m, DnsServer *s); +DnsServer *manager_get_dns_server(Manager *m); +void manager_next_dns_server(Manager *m); + +bool dns_server_address_valid(int family, const union in_addr_union *sa); + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref); + +extern const struct hash_ops dns_server_hash_ops; diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-stream.c b/src/grp-resolve/systemd-resolved/resolved-dns-stream.c new file mode 100644 index 0000000000..5f77d47f64 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-stream.c @@ -0,0 +1,419 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <netinet/tcp.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/missing.h" + +#include "resolved-dns-stream.h" + +#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC) +#define DNS_STREAMS_MAX 128 + +static void dns_stream_stop(DnsStream *s) { + assert(s); + + s->io_event_source = sd_event_source_unref(s->io_event_source); + s->timeout_event_source = sd_event_source_unref(s->timeout_event_source); + s->fd = safe_close(s->fd); +} + +static int dns_stream_update_io(DnsStream *s) { + int f = 0; + + assert(s); + + if (s->write_packet && s->n_written < sizeof(s->write_size) + s->write_packet->size) + f |= EPOLLOUT; + if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size) + f |= EPOLLIN; + + return sd_event_source_set_io_events(s->io_event_source, f); +} + +static int dns_stream_complete(DnsStream *s, int error) { + assert(s); + + dns_stream_stop(s); + + if (s->complete) + s->complete(s, error); + else /* the default action if no completion function is set is to close the stream */ + dns_stream_unref(s); + + return 0; +} + +static int dns_stream_identify(DnsStream *s) { + union { + struct cmsghdr header; /* For alignment */ + uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) + + EXTRA_CMSG_SPACE /* kernel appears to require extra space */]; + } control; + struct msghdr mh = {}; + struct cmsghdr *cmsg; + socklen_t sl; + int r; + + assert(s); + + if (s->identified) + return 0; + + /* Query the local side */ + s->local_salen = sizeof(s->local); + r = getsockname(s->fd, &s->local.sa, &s->local_salen); + if (r < 0) + return -errno; + if (s->local.sa.sa_family == AF_INET6 && s->ifindex <= 0) + s->ifindex = s->local.in6.sin6_scope_id; + + /* Query the remote side */ + s->peer_salen = sizeof(s->peer); + r = getpeername(s->fd, &s->peer.sa, &s->peer_salen); + if (r < 0) + return -errno; + if (s->peer.sa.sa_family == AF_INET6 && s->ifindex <= 0) + s->ifindex = s->peer.in6.sin6_scope_id; + + /* Check consistency */ + assert(s->peer.sa.sa_family == s->local.sa.sa_family); + assert(IN_SET(s->peer.sa.sa_family, AF_INET, AF_INET6)); + + /* Query connection meta information */ + sl = sizeof(control); + if (s->peer.sa.sa_family == AF_INET) { + r = getsockopt(s->fd, IPPROTO_IP, IP_PKTOPTIONS, &control, &sl); + if (r < 0) + return -errno; + } else if (s->peer.sa.sa_family == AF_INET6) { + + r = getsockopt(s->fd, IPPROTO_IPV6, IPV6_2292PKTOPTIONS, &control, &sl); + if (r < 0) + return -errno; + } else + return -EAFNOSUPPORT; + + mh.msg_control = &control; + mh.msg_controllen = sl; + + CMSG_FOREACH(cmsg, &mh) { + + if (cmsg->cmsg_level == IPPROTO_IPV6) { + assert(s->peer.sa.sa_family == AF_INET6); + + switch (cmsg->cmsg_type) { + + case IPV6_PKTINFO: { + struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); + + if (s->ifindex <= 0) + s->ifindex = i->ipi6_ifindex; + break; + } + + case IPV6_HOPLIMIT: + s->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + + } else if (cmsg->cmsg_level == IPPROTO_IP) { + assert(s->peer.sa.sa_family == AF_INET); + + switch (cmsg->cmsg_type) { + + case IP_PKTINFO: { + struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); + + if (s->ifindex <= 0) + s->ifindex = i->ipi_ifindex; + break; + } + + case IP_TTL: + s->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + } + } + + /* The Linux kernel sets the interface index to the loopback + * device if the connection came from the local host since it + * avoids the routing table in such a case. Let's unset the + * interface index in such a case. */ + if (s->ifindex == LOOPBACK_IFINDEX) + s->ifindex = 0; + + /* If we don't know the interface index still, we look for the + * first local interface with a matching address. Yuck! */ + if (s->ifindex <= 0) + s->ifindex = manager_find_ifindex(s->manager, s->local.sa.sa_family, s->local.sa.sa_family == AF_INET ? (union in_addr_union*) &s->local.in.sin_addr : (union in_addr_union*) &s->local.in6.sin6_addr); + + if (s->protocol == DNS_PROTOCOL_LLMNR && s->ifindex > 0) { + uint32_t ifindex = htobe32(s->ifindex); + + /* Make sure all packets for this connection are sent on the same interface */ + if (s->local.sa.sa_family == AF_INET) { + r = setsockopt(s->fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + log_debug_errno(errno, "Failed to invoke IP_UNICAST_IF: %m"); + } else if (s->local.sa.sa_family == AF_INET6) { + r = setsockopt(s->fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex)); + if (r < 0) + log_debug_errno(errno, "Failed to invoke IPV6_UNICAST_IF: %m"); + } + } + + s->identified = true; + + return 0; +} + +static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) { + DnsStream *s = userdata; + + assert(s); + + return dns_stream_complete(s, ETIMEDOUT); +} + +static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *userdata) { + DnsStream *s = userdata; + int r; + + assert(s); + + r = dns_stream_identify(s); + if (r < 0) + return dns_stream_complete(s, -r); + + if ((revents & EPOLLOUT) && + s->write_packet && + s->n_written < sizeof(s->write_size) + s->write_packet->size) { + + struct iovec iov[2]; + ssize_t ss; + + iov[0].iov_base = &s->write_size; + iov[0].iov_len = sizeof(s->write_size); + iov[1].iov_base = DNS_PACKET_DATA(s->write_packet); + iov[1].iov_len = s->write_packet->size; + + IOVEC_INCREMENT(iov, 2, s->n_written); + + ss = writev(fd, iov, 2); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return dns_stream_complete(s, errno); + } else + s->n_written += ss; + + /* Are we done? If so, disable the event source for EPOLLOUT */ + if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) { + r = dns_stream_update_io(s); + if (r < 0) + return dns_stream_complete(s, -r); + } + } + + if ((revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) && + (!s->read_packet || + s->n_read < sizeof(s->read_size) + s->read_packet->size)) { + + if (s->n_read < sizeof(s->read_size)) { + ssize_t ss; + + ss = read(fd, (uint8_t*) &s->read_size + s->n_read, sizeof(s->read_size) - s->n_read); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return dns_stream_complete(s, errno); + } else if (ss == 0) + return dns_stream_complete(s, ECONNRESET); + else + s->n_read += ss; + } + + if (s->n_read >= sizeof(s->read_size)) { + + if (be16toh(s->read_size) < DNS_PACKET_HEADER_SIZE) + return dns_stream_complete(s, EBADMSG); + + if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size)) { + ssize_t ss; + + if (!s->read_packet) { + r = dns_packet_new(&s->read_packet, s->protocol, be16toh(s->read_size)); + if (r < 0) + return dns_stream_complete(s, -r); + + s->read_packet->size = be16toh(s->read_size); + s->read_packet->ipproto = IPPROTO_TCP; + s->read_packet->family = s->peer.sa.sa_family; + s->read_packet->ttl = s->ttl; + s->read_packet->ifindex = s->ifindex; + + if (s->read_packet->family == AF_INET) { + s->read_packet->sender.in = s->peer.in.sin_addr; + s->read_packet->sender_port = be16toh(s->peer.in.sin_port); + s->read_packet->destination.in = s->local.in.sin_addr; + s->read_packet->destination_port = be16toh(s->local.in.sin_port); + } else { + assert(s->read_packet->family == AF_INET6); + s->read_packet->sender.in6 = s->peer.in6.sin6_addr; + s->read_packet->sender_port = be16toh(s->peer.in6.sin6_port); + s->read_packet->destination.in6 = s->local.in6.sin6_addr; + s->read_packet->destination_port = be16toh(s->local.in6.sin6_port); + + if (s->read_packet->ifindex == 0) + s->read_packet->ifindex = s->peer.in6.sin6_scope_id; + if (s->read_packet->ifindex == 0) + s->read_packet->ifindex = s->local.in6.sin6_scope_id; + } + } + + ss = read(fd, + (uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size), + sizeof(s->read_size) + be16toh(s->read_size) - s->n_read); + if (ss < 0) { + if (errno != EINTR && errno != EAGAIN) + return dns_stream_complete(s, errno); + } else if (ss == 0) + return dns_stream_complete(s, ECONNRESET); + else + s->n_read += ss; + } + + /* Are we done? If so, disable the event source for EPOLLIN */ + if (s->n_read >= sizeof(s->read_size) + be16toh(s->read_size)) { + r = dns_stream_update_io(s); + if (r < 0) + return dns_stream_complete(s, -r); + + /* If there's a packet handler + * installed, call that. Note that + * this is optional... */ + if (s->on_packet) + return s->on_packet(s); + } + } + } + + if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) && + (s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size)) + return dns_stream_complete(s, 0); + + return 0; +} + +DnsStream *dns_stream_unref(DnsStream *s) { + if (!s) + return NULL; + + assert(s->n_ref > 0); + s->n_ref--; + + if (s->n_ref > 0) + return NULL; + + dns_stream_stop(s); + + if (s->manager) { + LIST_REMOVE(streams, s->manager->dns_streams, s); + s->manager->n_dns_streams--; + } + + dns_packet_unref(s->write_packet); + dns_packet_unref(s->read_packet); + + return mfree(s); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref); + +DnsStream *dns_stream_ref(DnsStream *s) { + if (!s) + return NULL; + + assert(s->n_ref > 0); + s->n_ref++; + + return s; +} + +int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) { + _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; + int r; + + assert(m); + assert(fd >= 0); + + if (m->n_dns_streams > DNS_STREAMS_MAX) + return -EBUSY; + + s = new0(DnsStream, 1); + if (!s) + return -ENOMEM; + + s->n_ref = 1; + s->fd = -1; + s->protocol = protocol; + + r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s); + if (r < 0) + return r; + + (void) sd_event_source_set_description(s->io_event_source, "dns-stream-io"); + + r = sd_event_add_time( + m->event, + &s->timeout_event_source, + clock_boottime_or_monotonic(), + now(clock_boottime_or_monotonic()) + DNS_STREAM_TIMEOUT_USEC, 0, + on_stream_timeout, s); + if (r < 0) + return r; + + (void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout"); + + LIST_PREPEND(streams, m->dns_streams, s); + s->manager = m; + s->fd = fd; + m->n_dns_streams++; + + *ret = s; + s = NULL; + + return 0; +} + +int dns_stream_write_packet(DnsStream *s, DnsPacket *p) { + assert(s); + + if (s->write_packet) + return -EBUSY; + + s->write_packet = dns_packet_ref(p); + s->write_size = htobe16(p->size); + s->n_written = 0; + + return dns_stream_update_io(s); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-stream.h b/src/grp-resolve/systemd-resolved/resolved-dns-stream.h new file mode 100644 index 0000000000..3d5a3c22d1 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-stream.h @@ -0,0 +1,81 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/socket-util.h" + +typedef struct DnsStream DnsStream; + +#include "resolved-dns-transaction.h" +#include "resolved-manager.h" + +/* Streams are used by three subsystems: + * + * 1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP + * 2. The LLMNR logic when accepting a TCP-based lookup + * 3. The DNS stub logic when accepting a TCP-based lookup + */ + +struct DnsStream { + Manager *manager; + int n_ref; + + DnsProtocol protocol; + + int fd; + union sockaddr_union peer; + socklen_t peer_salen; + union sockaddr_union local; + socklen_t local_salen; + int ifindex; + uint32_t ttl; + bool identified; + + sd_event_source *io_event_source; + sd_event_source *timeout_event_source; + + be16_t write_size, read_size; + DnsPacket *write_packet, *read_packet; + size_t n_written, n_read; + + int (*on_packet)(DnsStream *s); + int (*complete)(DnsStream *s, int error); + + DnsTransaction *transaction; /* when used by the transaction logic */ + DnsQuery *query; /* when used by the DNS stub logic */ + + LIST_FIELDS(DnsStream, streams); +}; + +int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd); +DnsStream *dns_stream_unref(DnsStream *s); +DnsStream *dns_stream_ref(DnsStream *s); + +int dns_stream_write_packet(DnsStream *s, DnsPacket *p); + +static inline bool DNS_STREAM_QUEUED(DnsStream *s) { + assert(s); + + if (s->fd < 0) /* already stopped? */ + return false; + + return !!s->write_packet; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-stub.c b/src/grp-resolve/systemd-resolved/resolved-dns-stub.c new file mode 100644 index 0000000000..ad49862a70 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-stub.c @@ -0,0 +1,539 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/fd-util.h" +#include "systemd-basic/socket-util.h" + +#include "resolved-dns-stub.h" + +/* The MTU of the loopback device is 64K on Linux, advertise that as maximum datagram size, but subtract the Ethernet, + * IP and UDP header sizes */ +#define ADVERTISE_DATAGRAM_SIZE_MAX (65536U-14U-20U-8U) + +static int manager_dns_stub_udp_fd(Manager *m); +static int manager_dns_stub_tcp_fd(Manager *m); + +static int dns_stub_make_reply_packet( + uint16_t id, + int rcode, + DnsQuestion *q, + DnsAnswer *answer, + bool add_opt, /* add an OPT RR to this packet */ + bool edns0_do, /* set the EDNS0 DNSSEC OK bit */ + bool ad, /* set the DNSSEC authenticated data bit */ + DnsPacket **ret) { + + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsResourceRecord *rr; + unsigned c = 0; + int r; + + /* Note that we don't bother with any additional RRs, as this is stub is for local lookups only, and hence + * roundtrips aren't expensive. */ + + r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0); + if (r < 0) + return r; + + /* If the client didn't do EDNS, clamp the rcode to 4 bit */ + if (!add_opt && rcode > 0xF) + rcode = DNS_RCODE_SERVFAIL; + + DNS_PACKET_HEADER(p)->id = id; + DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( + 1 /* qr */, + 0 /* opcode */, + 0 /* aa */, + 0 /* tc */, + 1 /* rd */, + 1 /* ra */, + ad /* ad */, + 0 /* cd */, + rcode)); + + r = dns_packet_append_question(p, q); + if (r < 0) + return r; + DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); + + DNS_ANSWER_FOREACH(rr, answer) { + r = dns_question_matches_rr(q, rr, NULL); + if (r < 0) + return r; + if (r > 0) + goto add; + + r = dns_question_matches_cname_or_dname(q, rr, NULL); + if (r < 0) + return r; + if (r > 0) + goto add; + + continue; + add: + r = dns_packet_append_rr(p, rr, NULL, NULL); + if (r < 0) + return r; + + c++; + } + DNS_PACKET_HEADER(p)->ancount = htobe16(c); + + if (add_opt) { + r = dns_packet_append_opt(p, ADVERTISE_DATAGRAM_SIZE_MAX, edns0_do, rcode, NULL); + if (r < 0) + return r; + } + + *ret = p; + p = NULL; + + return 0; +} + +static void dns_stub_detach_stream(DnsStream *s) { + assert(s); + + s->complete = NULL; + s->on_packet = NULL; + s->query = NULL; +} + +static int dns_stub_send(Manager *m, DnsStream *s, DnsPacket *p, DnsPacket *reply) { + int r; + + assert(m); + assert(p); + assert(reply); + + if (s) + r = dns_stream_write_packet(s, reply); + else { + int fd; + + /* Truncate the message to the right size */ + if (reply->size > DNS_PACKET_PAYLOAD_SIZE_MAX(p)) { + dns_packet_truncate(reply, DNS_PACKET_UNICAST_SIZE_MAX); + DNS_PACKET_HEADER(reply)->flags = htobe16(be16toh(DNS_PACKET_HEADER(reply)->flags) | DNS_PACKET_FLAG_TC); + } + + fd = manager_dns_stub_udp_fd(m); + if (fd < 0) + return log_debug_errno(fd, "Failed to get reply socket: %m"); + + /* Note that it is essential here that we explicitly choose the source IP address for this packet. This + * is because otherwise the kernel will choose it automatically based on the routing table and will + * thus pick 127.0.0.1 rather than 127.0.0.53. */ + + r = manager_send(m, fd, LOOPBACK_IFINDEX, p->family, &p->sender, p->sender_port, &p->destination, reply); + } + if (r < 0) + return log_debug_errno(r, "Failed to send reply packet: %m"); + + return 0; +} + +static int dns_stub_send_failure(Manager *m, DnsStream *s, DnsPacket *p, int rcode) { + _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; + int r; + + assert(m); + assert(p); + + r = dns_stub_make_reply_packet(DNS_PACKET_ID(p), rcode, p->question, NULL, !!p->opt, DNS_PACKET_DO(p), false, &reply); + if (r < 0) + return log_debug_errno(r, "Failed to build failure packet: %m"); + + return dns_stub_send(m, s, p, reply); +} + +static void dns_stub_query_complete(DnsQuery *q) { + int r; + + assert(q); + assert(q->request_dns_packet); + + switch (q->state) { + + case DNS_TRANSACTION_SUCCESS: { + _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; + + r = dns_stub_make_reply_packet( + DNS_PACKET_ID(q->request_dns_packet), + q->answer_rcode, + q->question_idna, + q->answer, + !!q->request_dns_packet->opt, + DNS_PACKET_DO(q->request_dns_packet), + DNS_PACKET_DO(q->request_dns_packet) && q->answer_authenticated, + &reply); + if (r < 0) { + log_debug_errno(r, "Failed to build reply packet: %m"); + break; + } + + (void) dns_stub_send(q->manager, q->request_dns_stream, q->request_dns_packet, reply); + break; + } + + case DNS_TRANSACTION_RCODE_FAILURE: + (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, q->answer_rcode); + break; + + case DNS_TRANSACTION_NOT_FOUND: + (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_NXDOMAIN); + break; + + case DNS_TRANSACTION_TIMEOUT: + case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED: + /* Propagate a timeout as a no packet, i.e. that the client also gets a timeout */ + break; + + case DNS_TRANSACTION_NO_SERVERS: + case DNS_TRANSACTION_INVALID_REPLY: + case DNS_TRANSACTION_ERRNO: + case DNS_TRANSACTION_ABORTED: + case DNS_TRANSACTION_DNSSEC_FAILED: + case DNS_TRANSACTION_NO_TRUST_ANCHOR: + case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED: + case DNS_TRANSACTION_NETWORK_DOWN: + (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL); + break; + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + default: + assert_not_reached("Impossible state"); + } + + /* If there's a packet to write set, let's leave the stream around */ + if (q->request_dns_stream && DNS_STREAM_QUEUED(q->request_dns_stream)) { + + /* Detach the stream from our query (make it an orphan), but do not drop the reference to it. The + * default completion action of the stream will drop the reference. */ + + dns_stub_detach_stream(q->request_dns_stream); + q->request_dns_stream = NULL; + } + + dns_query_free(q); +} + +static int dns_stub_stream_complete(DnsStream *s, int error) { + assert(s); + + log_debug_errno(error, "DNS TCP connection terminated, destroying query: %m"); + + assert(s->query); + dns_query_free(s->query); + + return 0; +} + +static void dns_stub_process_query(Manager *m, DnsStream *s, DnsPacket *p) { + DnsQuery *q = NULL; + int r; + + assert(m); + assert(p); + assert(p->protocol == DNS_PROTOCOL_DNS); + + /* Takes ownership of the *s stream object */ + + if (in_addr_is_localhost(p->family, &p->sender) <= 0 || + in_addr_is_localhost(p->family, &p->destination) <= 0) { + log_error("Got packet on unexpected IP range, refusing."); + dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL); + goto fail; + } + + r = dns_packet_extract(p); + if (r < 0) { + log_debug_errno(r, "Failed to extract resources from incoming packet, ignoring packet: %m"); + dns_stub_send_failure(m, s, p, DNS_RCODE_FORMERR); + goto fail; + } + + if (!DNS_PACKET_VERSION_SUPPORTED(p)) { + log_debug("Got EDNS OPT field with unsupported version number."); + dns_stub_send_failure(m, s, p, DNS_RCODE_BADVERS); + goto fail; + } + + if (dns_type_is_obsolete(p->question->keys[0]->type)) { + log_debug("Got message with obsolete key type, refusing."); + dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP); + goto fail; + } + + if (dns_type_is_zone_transer(p->question->keys[0]->type)) { + log_debug("Got request for zone transfer, refusing."); + dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP); + goto fail; + } + + if (!DNS_PACKET_RD(p)) { + /* If the "rd" bit is off (i.e. recursion was not requested), then refuse operation */ + log_debug("Got request with recursion disabled, refusing."); + dns_stub_send_failure(m, s, p, DNS_RCODE_REFUSED); + goto fail; + } + + if (DNS_PACKET_DO(p) && DNS_PACKET_CD(p)) { + log_debug("Got request with DNSSEC CD bit set, refusing."); + dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP); + goto fail; + } + + r = dns_query_new(m, &q, p->question, p->question, 0, SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_SEARCH|SD_RESOLVED_NO_CNAME); + if (r < 0) { + log_error_errno(r, "Failed to generate query object: %m"); + dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL); + goto fail; + } + + /* Request that the TTL is corrected by the cached time for this lookup, so that we return vaguely useful TTLs */ + q->clamp_ttl = true; + + q->request_dns_packet = dns_packet_ref(p); + q->request_dns_stream = dns_stream_ref(s); /* make sure the stream stays around until we can send a reply through it */ + q->complete = dns_stub_query_complete; + + if (s) { + s->on_packet = NULL; + s->complete = dns_stub_stream_complete; + s->query = q; + } + + r = dns_query_go(q); + if (r < 0) { + log_error_errno(r, "Failed to start query: %m"); + dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL); + goto fail; + } + + log_info("Processing query..."); + return; + +fail: + if (s && DNS_STREAM_QUEUED(s)) + dns_stub_detach_stream(s); + + dns_query_free(q); +} + +static int on_dns_stub_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + Manager *m = userdata; + int r; + + r = manager_recv(m, fd, DNS_PROTOCOL_DNS, &p); + if (r <= 0) + return r; + + if (dns_packet_validate_query(p) > 0) { + log_debug("Got DNS stub UDP query packet for id %u", DNS_PACKET_ID(p)); + + dns_stub_process_query(m, NULL, p); + } else + log_debug("Invalid DNS stub UDP packet, ignoring."); + + return 0; +} + +static int manager_dns_stub_udp_fd(Manager *m) { + static const int one = 1; + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(53), + .in.sin_addr.s_addr = htobe32(INADDR_DNS_STUB), + }; + _cleanup_close_ int fd = -1; + int r; + + if (m->dns_stub_udp_fd >= 0) + return m->dns_stub_udp_fd; + + fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one) < 0) + return -errno; + + if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof one) < 0) + return -errno; + + if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof one) < 0) + return -errno; + + /* Make sure no traffic from outside the local host can leak to onto this socket */ + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0) + return -errno; + + if (bind(fd, &sa.sa, sizeof(sa.in)) < 0) + return -errno; + + r = sd_event_add_io(m->event, &m->dns_stub_udp_event_source, fd, EPOLLIN, on_dns_stub_packet, m); + if (r < 0) + return r; + + (void) sd_event_source_set_description(m->dns_stub_udp_event_source, "dns-stub-udp"); + m->dns_stub_udp_fd = fd; + fd = -1; + + return m->dns_stub_udp_fd; +} + +static int on_dns_stub_stream_packet(DnsStream *s) { + assert(s); + assert(s->read_packet); + + if (dns_packet_validate_query(s->read_packet) > 0) { + log_debug("Got DNS stub TCP query packet for id %u", DNS_PACKET_ID(s->read_packet)); + + dns_stub_process_query(s->manager, s, s->read_packet); + } else + log_debug("Invalid DNS stub TCP packet, ignoring."); + + /* Drop the reference to the stream. Either a query was created and added its own reference to the stream now, + * or that didn't happen in which case we want to free the stream */ + dns_stream_unref(s); + + return 0; +} + +static int on_dns_stub_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + DnsStream *stream; + Manager *m = userdata; + int cfd, r; + + cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (cfd < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + r = dns_stream_new(m, &stream, DNS_PROTOCOL_DNS, cfd); + if (r < 0) { + safe_close(cfd); + return r; + } + + stream->on_packet = on_dns_stub_stream_packet; + + /* We let the reference to the stream dangling here, it will either be dropped by the default "complete" action + * of the stream, or by our packet callback, or when the manager is shut down. */ + + return 0; +} + +static int manager_dns_stub_tcp_fd(Manager *m) { + static const int one = 1; + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_addr.s_addr = htobe32(INADDR_DNS_STUB), + .in.sin_port = htobe16(53), + }; + _cleanup_close_ int fd = -1; + int r; + + if (m->dns_stub_tcp_fd >= 0) + return m->dns_stub_tcp_fd; + + fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (fd < 0) + return -errno; + + if (setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof one) < 0) + return -errno; + + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one) < 0) + return -errno; + + if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof one) < 0) + return -errno; + + if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof one) < 0) + return -errno; + + /* Make sure no traffic from outside the local host can leak to onto this socket */ + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0) + return -errno; + + if (bind(fd, &sa.sa, sizeof(sa.in)) < 0) + return -errno; + + if (listen(fd, SOMAXCONN) < 0) + return -errno; + + r = sd_event_add_io(m->event, &m->dns_stub_tcp_event_source, fd, EPOLLIN, on_dns_stub_stream, m); + if (r < 0) + return r; + + (void) sd_event_source_set_description(m->dns_stub_tcp_event_source, "dns-stub-tcp"); + m->dns_stub_tcp_fd = fd; + fd = -1; + + return m->dns_stub_tcp_fd; +} + +int manager_dns_stub_start(Manager *m) { + const char *t = "UDP"; + int r = 0; + + assert(m); + + if (IN_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_YES, DNS_STUB_LISTENER_UDP)) + r = manager_dns_stub_udp_fd(m); + + if (r >= 0 && + IN_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_YES, DNS_STUB_LISTENER_TCP)) { + t = "TCP"; + r = manager_dns_stub_tcp_fd(m); + } + + if (IN_SET(r, -EADDRINUSE, -EPERM)) { + if (r == -EADDRINUSE) + log_warning_errno(r, + "Another process is already listening on %s socket 127.0.0.53:53.\n" + "Turning off local DNS stub support.", t); + else + log_warning_errno(r, + "Failed to listen on %s socket 127.0.0.53:53: %m.\n" + "Turning off local DNS stub support.", t); + manager_dns_stub_stop(m); + } else if (r < 0) + return log_error_errno(r, "Failed to listen on %s socket 127.0.0.53:53: %m", t); + + return 0; +} + +void manager_dns_stub_stop(Manager *m) { + assert(m); + + m->dns_stub_udp_event_source = sd_event_source_unref(m->dns_stub_udp_event_source); + m->dns_stub_tcp_event_source = sd_event_source_unref(m->dns_stub_tcp_event_source); + + m->dns_stub_udp_fd = safe_close(m->dns_stub_udp_fd); + m->dns_stub_tcp_fd = safe_close(m->dns_stub_tcp_fd); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-stub.h b/src/grp-resolve/systemd-resolved/resolved-dns-stub.h new file mode 100644 index 0000000000..12b86f6753 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-stub.h @@ -0,0 +1,28 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +/* 127.0.0.53 in native endian */ +#define INADDR_DNS_STUB ((in_addr_t) 0x7f000035U) + +void manager_dns_stub_stop(Manager *m); +int manager_dns_stub_start(Manager *m); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.c b/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.c new file mode 100644 index 0000000000..53d1940d9e --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.c @@ -0,0 +1,414 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "sd-netlink/local-addresses.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/hostname-util.h" + +#include "resolved-dns-synthesize.h" + +int dns_synthesize_ifindex(int ifindex) { + + /* When the caller asked for resolving on a specific + * interface, we synthesize the answer for that + * interface. However, if nothing specific was claimed and we + * only return localhost RRs, we synthesize the answer for + * localhost. */ + + if (ifindex > 0) + return ifindex; + + return LOOPBACK_IFINDEX; +} + +int dns_synthesize_family(uint64_t flags) { + + /* Picks an address family depending on set flags. This is + * purely for synthesized answers, where the family we return + * for the reply should match what was requested in the + * question, even though we are synthesizing the answer + * here. */ + + if (!(flags & SD_RESOLVED_DNS)) { + if (flags & (SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_MDNS_IPV4)) + return AF_INET; + if (flags & (SD_RESOLVED_LLMNR_IPV6|SD_RESOLVED_MDNS_IPV6)) + return AF_INET6; + } + + return AF_UNSPEC; +} + +DnsProtocol dns_synthesize_protocol(uint64_t flags) { + + /* Similar as dns_synthesize_family() but does this for the + * protocol. If resolving via DNS was requested, we claim it + * was DNS. Similar, if nothing specific was + * requested. However, if only resolving via LLMNR was + * requested we return that. */ + + if (flags & SD_RESOLVED_DNS) + return DNS_PROTOCOL_DNS; + if (flags & SD_RESOLVED_LLMNR) + return DNS_PROTOCOL_LLMNR; + if (flags & SD_RESOLVED_MDNS) + return DNS_PROTOCOL_MDNS; + + return DNS_PROTOCOL_DNS; +} + +static int synthesize_localhost_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) { + int r; + + assert(m); + assert(key); + assert(answer); + + r = dns_answer_reserve(answer, 2); + if (r < 0) + return r; + + if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, dns_resource_key_name(key)); + if (!rr) + return -ENOMEM; + + rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK); + + r = dns_answer_add(*answer, rr, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, dns_resource_key_name(key)); + if (!rr) + return -ENOMEM; + + rr->aaaa.in6_addr = in6addr_loopback; + + r = dns_answer_add(*answer, rr, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex, DnsAnswerFlags flags) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from); + if (!rr) + return -ENOMEM; + + rr->ptr.name = strdup(to); + if (!rr->ptr.name) + return -ENOMEM; + + return dns_answer_add(*answer, rr, ifindex, flags); +} + +static int synthesize_localhost_ptr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) { + int r; + + assert(m); + assert(key); + assert(answer); + + if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) { + r = dns_answer_reserve(answer, 1); + if (r < 0) + return r; + + r = answer_add_ptr(answer, dns_resource_key_name(key), "localhost", dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int answer_add_addresses_rr( + DnsAnswer **answer, + const char *name, + struct local_address *addresses, + unsigned n_addresses) { + + unsigned j; + int r; + + assert(answer); + assert(name); + + r = dns_answer_reserve(answer, n_addresses); + if (r < 0) + return r; + + for (j = 0; j < n_addresses; j++) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name); + if (r < 0) + return r; + + r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int answer_add_addresses_ptr( + DnsAnswer **answer, + const char *name, + struct local_address *addresses, + unsigned n_addresses, + int af, const union in_addr_union *match) { + + unsigned j; + int r; + + assert(answer); + assert(name); + + for (j = 0; j < n_addresses; j++) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + if (af != AF_UNSPEC) { + + if (addresses[j].family != af) + continue; + + if (match && !in_addr_equal(af, match, &addresses[j].address)) + continue; + } + + r = dns_answer_reserve(answer, 1); + if (r < 0) + return r; + + r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name); + if (r < 0) + return r; + + r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int synthesize_system_hostname_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) { + _cleanup_free_ struct local_address *addresses = NULL; + int n = 0, af; + + assert(m); + assert(key); + assert(answer); + + af = dns_type_to_af(key->type); + if (af >= 0) { + n = local_addresses(m->rtnl, ifindex, af, &addresses); + if (n < 0) + return n; + + if (n == 0) { + struct local_address buffer[2]; + + /* If we have no local addresses then use ::1 + * and 127.0.0.2 as local ones. */ + + if (af == AF_INET || af == AF_UNSPEC) + buffer[n++] = (struct local_address) { + .family = AF_INET, + .ifindex = dns_synthesize_ifindex(ifindex), + .address.in.s_addr = htobe32(0x7F000002), + }; + + if (af == AF_INET6 || af == AF_UNSPEC) + buffer[n++] = (struct local_address) { + .family = AF_INET6, + .ifindex = dns_synthesize_ifindex(ifindex), + .address.in6 = in6addr_loopback, + }; + + return answer_add_addresses_rr(answer, dns_resource_key_name(key), buffer, n); + } + } + + return answer_add_addresses_rr(answer, dns_resource_key_name(key), addresses, n); +} + +static int synthesize_system_hostname_ptr(Manager *m, int af, const union in_addr_union *address, int ifindex, DnsAnswer **answer) { + _cleanup_free_ struct local_address *addresses = NULL; + int n, r; + + assert(m); + assert(address); + assert(answer); + + if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) { + + /* Always map the IPv4 address 127.0.0.2 to the local + * hostname, in addition to "localhost": */ + + r = dns_answer_reserve(answer, 3); + if (r < 0) + return r; + + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->llmnr_hostname, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", m->mdns_hostname, dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", dns_synthesize_ifindex(ifindex), DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + return 0; + } + + n = local_addresses(m->rtnl, ifindex, af, &addresses); + if (n < 0) + return n; + + r = answer_add_addresses_ptr(answer, m->llmnr_hostname, addresses, n, af, address); + if (r < 0) + return r; + + return answer_add_addresses_ptr(answer, m->mdns_hostname, addresses, n, af, address); +} + +static int synthesize_gateway_rr(Manager *m, const DnsResourceKey *key, int ifindex, DnsAnswer **answer) { + _cleanup_free_ struct local_address *addresses = NULL; + int n = 0, af; + + assert(m); + assert(key); + assert(answer); + + af = dns_type_to_af(key->type); + if (af >= 0) { + n = local_gateways(m->rtnl, ifindex, af, &addresses); + if (n < 0) + return n; + } + + return answer_add_addresses_rr(answer, dns_resource_key_name(key), addresses, n); +} + +static int synthesize_gateway_ptr(Manager *m, int af, const union in_addr_union *address, int ifindex, DnsAnswer **answer) { + _cleanup_free_ struct local_address *addresses = NULL; + int n; + + assert(m); + assert(address); + assert(answer); + + n = local_gateways(m->rtnl, ifindex, af, &addresses); + if (n < 0) + return n; + + return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address); +} + +int dns_synthesize_answer( + Manager *m, + DnsQuestion *q, + int ifindex, + DnsAnswer **ret) { + + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnsResourceKey *key; + bool found = false; + int r; + + assert(m); + assert(q); + + DNS_QUESTION_FOREACH(key, q) { + union in_addr_union address; + const char *name; + int af; + + if (key->class != DNS_CLASS_IN && + key->class != DNS_CLASS_ANY) + continue; + + name = dns_resource_key_name(key); + + if (is_localhost(name)) { + + r = synthesize_localhost_rr(m, key, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize localhost RRs: %m"); + + } else if (manager_is_own_hostname(m, name)) { + + r = synthesize_system_hostname_rr(m, key, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize system hostname RRs: %m"); + + } else if (is_gateway_hostname(name)) { + + r = synthesize_gateway_rr(m, key, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize gateway RRs: %m"); + + } else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) || + dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) { + + r = synthesize_localhost_ptr(m, key, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m"); + + } else if (dns_name_address(name, &af, &address) > 0) { + + r = synthesize_system_hostname_ptr(m, af, &address, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m"); + + r = synthesize_gateway_ptr(m, af, &address, ifindex, &answer); + if (r < 0) + return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m"); + } else + continue; + + found = true; + } + + r = found; + + if (ret) { + *ret = answer; + answer = NULL; + } + + return r; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.h b/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.h new file mode 100644 index 0000000000..23b05587ac --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-synthesize.h @@ -0,0 +1,31 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-question.h" + +#include "resolved-manager.h" + +int dns_synthesize_ifindex(int ifindex); +int dns_synthesize_family(uint64_t flags); +DnsProtocol dns_synthesize_protocol(uint64_t flags); + +int dns_synthesize_answer(Manager *m, DnsQuestion *q, int ifindex, DnsAnswer **ret); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-transaction.c b/src/grp-resolve/systemd-resolved/resolved-dns-transaction.c new file mode 100644 index 0000000000..b17493d659 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-transaction.c @@ -0,0 +1,3107 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-messages.h> + +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/errno-list.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-cache.h" +#include "resolved-dns-transaction.h" +#include "resolved-llmnr.h" + +#define TRANSACTIONS_MAX 4096 + +static void dns_transaction_reset_answer(DnsTransaction *t) { + assert(t); + + t->received = dns_packet_unref(t->received); + t->answer = dns_answer_unref(t->answer); + t->answer_rcode = 0; + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; + t->answer_authenticated = false; + t->answer_nsec_ttl = (uint32_t) -1; + t->answer_errno = 0; +} + +static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { + DnsTransaction *z; + + assert(t); + + while ((z = set_steal_first(t->dnssec_transactions))) { + set_remove(z->notify_transactions, t); + set_remove(z->notify_transactions_done, t); + dns_transaction_gc(z); + } +} + +static void dns_transaction_close_connection(DnsTransaction *t) { + assert(t); + + if (t->stream) { + /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ + t->stream->complete = NULL; + t->stream->on_packet = NULL; + t->stream->transaction = NULL; + t->stream = dns_stream_unref(t->stream); + } + + t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); + t->dns_udp_fd = safe_close(t->dns_udp_fd); +} + +static void dns_transaction_stop_timeout(DnsTransaction *t) { + assert(t); + + t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); +} + +DnsTransaction* dns_transaction_free(DnsTransaction *t) { + DnsQueryCandidate *c; + DnsZoneItem *i; + DnsTransaction *z; + + if (!t) + return NULL; + + log_debug("Freeing transaction %" PRIu16 ".", t->id); + + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); + + dns_packet_unref(t->sent); + dns_transaction_reset_answer(t); + + dns_server_unref(t->server); + + if (t->scope) { + hashmap_remove_value(t->scope->transactions_by_key, t->key, t); + LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); + + if (t->id != 0) + hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); + } + + while ((c = set_steal_first(t->notify_query_candidates))) + set_remove(c->transactions, t); + set_free(t->notify_query_candidates); + + while ((c = set_steal_first(t->notify_query_candidates_done))) + set_remove(c->transactions, t); + set_free(t->notify_query_candidates_done); + + while ((i = set_steal_first(t->notify_zone_items))) + i->probe_transaction = NULL; + set_free(t->notify_zone_items); + + while ((i = set_steal_first(t->notify_zone_items_done))) + i->probe_transaction = NULL; + set_free(t->notify_zone_items_done); + + while ((z = set_steal_first(t->notify_transactions))) + set_remove(z->dnssec_transactions, t); + set_free(t->notify_transactions); + + while ((z = set_steal_first(t->notify_transactions_done))) + set_remove(z->dnssec_transactions, t); + set_free(t->notify_transactions_done); + + dns_transaction_flush_dnssec_transactions(t); + set_free(t->dnssec_transactions); + + dns_answer_unref(t->validated_keys); + dns_resource_key_unref(t->key); + + return mfree(t); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); + +bool dns_transaction_gc(DnsTransaction *t) { + assert(t); + + if (t->block_gc > 0) + return true; + + if (set_isempty(t->notify_query_candidates) && + set_isempty(t->notify_query_candidates_done) && + set_isempty(t->notify_zone_items) && + set_isempty(t->notify_zone_items_done) && + set_isempty(t->notify_transactions) && + set_isempty(t->notify_transactions_done)) { + dns_transaction_free(t); + return false; + } + + return true; +} + +static uint16_t pick_new_id(Manager *m) { + uint16_t new_id; + + /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of + * transactions, and it's much lower than the space of IDs. */ + + assert_cc(TRANSACTIONS_MAX < 0xFFFF); + + do + random_bytes(&new_id, sizeof(new_id)); + while (new_id == 0 || + hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); + + return new_id; +} + +int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { + _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; + int r; + + assert(ret); + assert(s); + assert(key); + + /* Don't allow looking up invalid or pseudo RRs */ + if (!dns_type_is_valid_query(key->type)) + return -EINVAL; + if (dns_type_is_obsolete(key->type)) + return -EOPNOTSUPP; + + /* We only support the IN class */ + if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) + return -EOPNOTSUPP; + + if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) + return -EBUSY; + + r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); + if (r < 0) + return r; + + t = new0(DnsTransaction, 1); + if (!t) + return -ENOMEM; + + t->dns_udp_fd = -1; + t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_nsec_ttl = (uint32_t) -1; + t->key = dns_resource_key_ref(key); + t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; + t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; + + t->id = pick_new_id(s->manager); + + r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); + if (r < 0) { + t->id = 0; + return r; + } + + r = hashmap_replace(s->transactions_by_key, t->key, t); + if (r < 0) { + hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); + return r; + } + + LIST_PREPEND(transactions_by_scope, s->transactions, t); + t->scope = s; + + s->manager->n_transactions_total++; + + if (ret) + *ret = t; + + t = NULL; + + return 0; +} + +static void dns_transaction_shuffle_id(DnsTransaction *t) { + uint16_t new_id; + assert(t); + + /* Pick a new ID for this transaction. */ + + new_id = pick_new_id(t->scope->manager); + assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); + + log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); + t->id = new_id; + + /* Make sure we generate a new packet with the new ID */ + t->sent = dns_packet_unref(t->sent); +} + +static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { + _cleanup_free_ char *pretty = NULL; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + DnsZoneItem *z; + + assert(t); + assert(p); + + if (manager_our_packet(t->scope->manager, p) != 0) + return; + + (void) in_addr_to_string(p->family, &p->sender, &pretty); + + log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", + t->id, + dns_resource_key_to_string(t->key, key_str, sizeof key_str), + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + af_to_name_short(t->scope->family), + strnull(pretty)); + + /* RFC 4795, Section 4.1 says that the peer with the + * lexicographically smaller IP address loses */ + if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { + log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); + return; + } + + log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); + + t->block_gc++; + + while ((z = set_first(t->notify_zone_items))) { + /* First, make sure the zone item drops the reference + * to us */ + dns_zone_item_probe_stop(z); + + /* Secondly, report this as conflict, so that we might + * look for a different hostname */ + dns_zone_item_conflict(z); + } + t->block_gc--; + + dns_transaction_gc(t); +} + +void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { + DnsQueryCandidate *c; + DnsZoneItem *z; + DnsTransaction *d; + const char *st; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + assert(t); + assert(!DNS_TRANSACTION_IS_LIVE(state)); + + if (state == DNS_TRANSACTION_DNSSEC_FAILED) { + dns_resource_key_to_string(t->key, key_str, sizeof key_str); + + log_struct(LOG_NOTICE, + LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), + LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), + "DNS_TRANSACTION=%" PRIu16, t->id, + "DNS_QUESTION=%s", key_str, + "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), + "DNS_SERVER=%s", dns_server_string(t->server), + "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level), + NULL); + } + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function. */ + + if (state == DNS_TRANSACTION_ERRNO) + st = errno_to_name(t->answer_errno); + else + st = dns_transaction_state_to_string(state); + + log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", + t->id, + dns_resource_key_to_string(t->key, key_str, sizeof key_str), + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + af_to_name_short(t->scope->family), + st, + t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), + t->answer_authenticated ? "authenticated" : "unsigned"); + + t->state = state; + + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); + + /* Notify all queries that are interested, but make sure the + * transaction isn't freed while we are still looking at it */ + t->block_gc++; + + SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) + dns_query_candidate_notify(c); + SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); + + SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) + dns_zone_item_notify(z); + SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); + + SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) + dns_transaction_notify(d, t); + SWAP_TWO(t->notify_transactions, t->notify_transactions_done); + + t->block_gc--; + dns_transaction_gc(t); +} + +static int dns_transaction_pick_server(DnsTransaction *t) { + DnsServer *server; + + assert(t); + assert(t->scope->protocol == DNS_PROTOCOL_DNS); + + /* Pick a DNS server and a feature level for it. */ + + server = dns_scope_get_dns_server(t->scope); + if (!server) + return -ESRCH; + + /* If we changed the server invalidate the feature level clamping, as the new server might have completely + * different properties. */ + if (server != t->server) + t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; + + t->current_feature_level = dns_server_possible_feature_level(server); + + /* Clamp the feature level if that is requested. */ + if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && + t->current_feature_level > t->clamp_feature_level) + t->current_feature_level = t->clamp_feature_level; + + log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); + + if (server == t->server) + return 0; + + dns_server_unref(t->server); + t->server = dns_server_ref(server); + + log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); + + return 1; +} + +static void dns_transaction_retry(DnsTransaction *t, bool next_server) { + int r; + + assert(t); + + log_debug("Retrying transaction %" PRIu16 ".", t->id); + + /* Before we try again, switch to a new server. */ + if (next_server) + dns_scope_next_dns_server(t->scope); + + r = dns_transaction_go(t); + if (r < 0) { + t->answer_errno = -r; + dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); + } +} + +static int dns_transaction_maybe_restart(DnsTransaction *t) { + int r; + + assert(t); + + /* Returns > 0 if the transaction was restarted, 0 if not */ + + if (!t->server) + return 0; + + if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) + return 0; + + /* The server's current feature level is lower than when we sent the original query. We learnt something from + the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to + restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include + OPT RR or DO bit. One of these cases is documented here, for example: + https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ + + log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); + dns_transaction_shuffle_id(t); + + r = dns_transaction_go(t); + if (r < 0) + return r; + + return 1; +} + +static int on_stream_complete(DnsStream *s, int error) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t; + + assert(s); + assert(s->transaction); + + /* Copy the data we care about out of the stream before we + * destroy it. */ + t = s->transaction; + p = dns_packet_ref(s->read_packet); + + dns_transaction_close_connection(t); + + if (ERRNO_IS_DISCONNECT(error)) { + usec_t usec; + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the + * question on this scope. */ + dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); + return 0; + } + + log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); + dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); + + dns_transaction_retry(t, true); + return 0; + } + if (error != 0) { + t->answer_errno = error; + dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); + return 0; + } + + if (dns_packet_validate_reply(p) <= 0) { + log_debug("Invalid TCP reply packet."); + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return 0; + } + + dns_scope_check_conflicts(t->scope, p); + + t->block_gc++; + dns_transaction_process_reply(t, p); + t->block_gc--; + + /* If the response wasn't useful, then complete the transition + * now. After all, we are the worst feature set now with TCP + * sockets, and there's really no point in retrying. */ + if (t->state == DNS_TRANSACTION_PENDING) + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + else + dns_transaction_gc(t); + + return 0; +} + +static int dns_transaction_open_tcp(DnsTransaction *t) { + _cleanup_close_ int fd = -1; + int r; + + assert(t); + + dns_transaction_close_connection(t); + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_DNS: + r = dns_transaction_pick_server(t); + if (r < 0) + return r; + + if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) + return -EOPNOTSUPP; + + r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); + if (r < 0) + return r; + + fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); + break; + + case DNS_PROTOCOL_LLMNR: + /* When we already received a reply to this (but it was truncated), send to its sender address */ + if (t->received) + fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); + else { + union in_addr_union address; + int family = AF_UNSPEC; + + /* Otherwise, try to talk to the owner of a + * the IP address, in case this is a reverse + * PTR lookup */ + + r = dns_name_address(dns_resource_key_name(t->key), &family, &address); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + if (family != t->scope->family) + return -ESRCH; + + fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); + } + + break; + + default: + return -EAFNOSUPPORT; + } + + if (fd < 0) + return fd; + + r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); + if (r < 0) + return r; + fd = -1; + + r = dns_stream_write_packet(t->stream, t->sent); + if (r < 0) { + t->stream = dns_stream_unref(t->stream); + return r; + } + + t->stream->complete = on_stream_complete; + t->stream->transaction = t; + + /* The interface index is difficult to determine if we are + * connecting to the local host, hence fill this in right away + * instead of determining it from the socket */ + t->stream->ifindex = dns_scope_ifindex(t->scope); + + dns_transaction_reset_answer(t); + + t->tried_stream = true; + + return 0; +} + +static void dns_transaction_cache_answer(DnsTransaction *t) { + assert(t); + + /* For mDNS we cache whenever we get the packet, rather than + * in each transaction. */ + if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) + return; + + /* Caching disabled? */ + if (!t->scope->manager->enable_cache) + return; + + /* We never cache if this packet is from the local host, under + * the assumption that a locally running DNS server would + * cache this anyway, and probably knows better when to flush + * the cache then we could. */ + if (!DNS_PACKET_SHALL_CACHE(t->received)) + return; + + dns_cache_put(&t->scope->cache, + t->key, + t->answer_rcode, + t->answer, + t->answer_authenticated, + t->answer_nsec_ttl, + 0, + t->received->family, + &t->received->sender); +} + +static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + SET_FOREACH(dt, t->dnssec_transactions, i) + if (DNS_TRANSACTION_IS_LIVE(dt->state)) + return true; + + return false; +} + +static int dns_transaction_dnssec_ready(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still + * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + switch (dt->state) { + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* Still ongoing */ + return 0; + + case DNS_TRANSACTION_RCODE_FAILURE: + if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { + log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); + goto fail; + } + + /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers + * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS + * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar + * RRs to make unsigned proofs. */ + + case DNS_TRANSACTION_SUCCESS: + /* All good. */ + break; + + case DNS_TRANSACTION_DNSSEC_FAILED: + /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC + * validationr result */ + + log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); + t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return 0; + + + default: + log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); + goto fail; + } + } + + /* All is ready, we can go and validate */ + return 1; + +fail: + t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return 0; +} + +static void dns_transaction_process_dnssec(DnsTransaction *t) { + int r; + + assert(t); + + /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ + r = dns_transaction_dnssec_ready(t); + if (r < 0) + goto fail; + if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ + return; + + /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better + * restart the lookup immediately. */ + r = dns_transaction_maybe_restart(t); + if (r < 0) + goto fail; + if (r > 0) /* Transaction got restarted... */ + return; + + /* All our auxiliary DNSSEC transactions are complete now. Try + * to validate our RRset now. */ + r = dns_transaction_validate_dnssec(t); + if (r == -EBADMSG) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + if (r < 0) + goto fail; + + if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && + t->scope->dnssec_mode == DNSSEC_YES) { + /* We are not in automatic downgrade mode, and the + * server is bad, refuse operation. */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return; + } + + if (!IN_SET(t->answer_dnssec_result, + _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ + DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ + DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ + DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return; + } + + if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) + dns_server_warn_downgrade(t->server); + + dns_transaction_cache_answer(t); + + if (t->answer_rcode == DNS_RCODE_SUCCESS) + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + else + dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); + + return; + +fail: + t->answer_errno = -r; + dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); +} + +static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { + int r; + + assert(t); + + /* Checks whether the answer is positive, i.e. either a direct + * answer to the question, or a CNAME/DNAME for it */ + + r = dns_answer_match_key(t->answer, t->key, flags); + if (r != 0) + return r; + + r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); + if (r != 0) + return r; + + return false; +} + +static int dns_transaction_fix_rcode(DnsTransaction *t) { + int r; + + assert(t); + + /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the + * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a + * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first + * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when + * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle + * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a + * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server + * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an + * incomplete CNAME/DNAME chain. + * + * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, + * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new + * lookup. */ + + if (t->answer_rcode != DNS_RCODE_NXDOMAIN) + return 0; + + r = dns_transaction_has_positive_answer(t, NULL); + if (r <= 0) + return r; + + t->answer_rcode = DNS_RCODE_SUCCESS; + return 0; +} + +void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { + usec_t ts; + int r; + + assert(t); + assert(p); + assert(t->scope); + assert(t->scope->manager); + + if (t->state != DNS_TRANSACTION_PENDING) + return; + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function. */ + + log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_LLMNR: + /* For LLMNR we will not accept any packets from other interfaces */ + + if (p->ifindex != dns_scope_ifindex(t->scope)) + return; + + if (p->family != t->scope->family) + return; + + /* Tentative packets are not full responses but still + * useful for identifying uniqueness conflicts during + * probing. */ + if (DNS_PACKET_LLMNR_T(p)) { + dns_transaction_tentative(t, p); + return; + } + + break; + + case DNS_PROTOCOL_MDNS: + /* For mDNS we will not accept any packets from other interfaces */ + + if (p->ifindex != dns_scope_ifindex(t->scope)) + return; + + if (p->family != t->scope->family) + return; + + break; + + case DNS_PROTOCOL_DNS: + /* Note that we do not need to verify the + * addresses/port numbers of incoming traffic, as we + * invoked connect() on our UDP socket in which case + * the kernel already does the needed verification for + * us. */ + break; + + default: + assert_not_reached("Invalid DNS protocol."); + } + + if (t->received != p) { + dns_packet_unref(t->received); + t->received = dns_packet_ref(p); + } + + t->answer_source = DNS_TRANSACTION_NETWORK; + + if (p->ipproto == IPPROTO_TCP) { + if (DNS_PACKET_TC(p)) { + /* Truncated via TCP? Somebody must be fucking with us */ + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + if (DNS_PACKET_ID(p) != t->id) { + /* Not the reply to our query? Somebody must be fucking with us */ + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + } + + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_DNS: + assert(t->server); + + if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { + + /* Request failed, immediately try again with reduced features */ + + if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_WORST) { + /* This was already at the lowest possible feature level? If so, we can't downgrade + * this transaction anymore, hence let's process the response, and accept the rcode. */ + log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); + break; + } + + /* Reduce this feature level by one and try again. */ + t->clamp_feature_level = t->current_feature_level - 1; + + log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", + dns_rcode_to_string(DNS_PACKET_RCODE(p)), + dns_server_feature_level_to_string(t->clamp_feature_level)); + + dns_transaction_retry(t, false /* use the same server */); + return; + } else if (DNS_PACKET_TC(p)) + dns_server_packet_truncated(t->server, t->current_feature_level); + + break; + + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + dns_scope_packet_received(t->scope, ts - t->start_usec); + break; + + default: + assert_not_reached("Invalid DNS protocol."); + } + + if (DNS_PACKET_TC(p)) { + + /* Truncated packets for mDNS are not allowed. Give up immediately. */ + if (t->scope->protocol == DNS_PROTOCOL_MDNS) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + log_debug("Reply truncated, retrying via TCP."); + + /* Response was truncated, let's try again with good old TCP */ + r = dns_transaction_open_tcp(t); + if (r == -ESRCH) { + /* No servers found? Damn! */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); + return; + } + if (r == -EOPNOTSUPP) { + /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ + dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); + return; + } + if (r < 0) { + /* On LLMNR, if we cannot connect to the host, + * we immediately give up */ + if (t->scope->protocol != DNS_PROTOCOL_DNS) + goto fail; + + /* On DNS, couldn't send? Try immediately again, with a new server */ + dns_transaction_retry(t, true); + } + + return; + } + + /* After the superficial checks, actually parse the message. */ + r = dns_packet_extract(p); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + if (t->server) { + /* Report that we successfully received a valid packet with a good rcode after we initially got a bad + * rcode and subsequently downgraded the protocol */ + + if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && + t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) + dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); + + /* Report that the OPT RR was missing */ + if (!p->opt) + dns_server_packet_bad_opt(t->server, t->current_feature_level); + + /* Report that we successfully received a packet */ + dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); + } + + /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ + r = dns_transaction_maybe_restart(t); + if (r < 0) + goto fail; + if (r > 0) /* Transaction got restarted... */ + return; + + if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { + + /* Only consider responses with equivalent query section to the request */ + r = dns_packet_is_reply_for(p, t->key); + if (r < 0) + goto fail; + if (r == 0) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + /* Install the answer as answer to the transaction */ + dns_answer_unref(t->answer); + t->answer = dns_answer_ref(p->answer); + t->answer_rcode = DNS_PACKET_RCODE(p); + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_authenticated = false; + + r = dns_transaction_fix_rcode(t); + if (r < 0) + goto fail; + + /* Block GC while starting requests for additional DNSSEC RRs */ + t->block_gc++; + r = dns_transaction_request_dnssec_keys(t); + t->block_gc--; + + /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ + if (!dns_transaction_gc(t)) + return; + + /* Requesting additional keys might have resulted in + * this transaction to fail, since the auxiliary + * request failed for some reason. If so, we are not + * in pending state anymore, and we should exit + * quickly. */ + if (t->state != DNS_TRANSACTION_PENDING) + return; + if (r < 0) + goto fail; + if (r > 0) { + /* There are DNSSEC transactions pending now. Update the state accordingly. */ + t->state = DNS_TRANSACTION_VALIDATING; + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); + return; + } + } + + dns_transaction_process_dnssec(t); + return; + +fail: + t->answer_errno = -r; + dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); +} + +static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t = userdata; + int r; + + assert(t); + assert(t->scope); + + r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); + if (ERRNO_IS_DISCONNECT(-r)) { + usec_t usec; + + /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next + * recvmsg(). Treat this like a lost packet. */ + + log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); + dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); + + dns_transaction_retry(t, true); + return 0; + } + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); + t->answer_errno = -r; + return 0; + } + + r = dns_packet_validate_reply(p); + if (r < 0) { + log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); + return 0; + } + if (r == 0) { + log_debug("Received inappropriate DNS packet as response, ignoring."); + return 0; + } + + if (DNS_PACKET_ID(p) != t->id) { + log_debug("Received packet with incorrect transaction ID, ignoring."); + return 0; + } + + dns_transaction_process_reply(t, p); + return 0; +} + +static int dns_transaction_emit_udp(DnsTransaction *t) { + int r; + + assert(t); + + if (t->scope->protocol == DNS_PROTOCOL_DNS) { + + r = dns_transaction_pick_server(t); + if (r < 0) + return r; + + if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) + return -EAGAIN; + + if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) + return -EOPNOTSUPP; + + if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ + int fd; + + dns_transaction_close_connection(t); + + fd = dns_scope_socket_udp(t->scope, t->server, 53); + if (fd < 0) + return fd; + + r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); + if (r < 0) { + safe_close(fd); + return r; + } + + (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); + t->dns_udp_fd = fd; + } + + r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); + if (r < 0) + return r; + } else + dns_transaction_close_connection(t); + + r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); + if (r < 0) + return r; + + dns_transaction_reset_answer(t); + + return 0; +} + +static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { + DnsTransaction *t = userdata; + + assert(s); + assert(t); + + if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { + /* Timeout reached? Increase the timeout for the server used */ + switch (t->scope->protocol) { + + case DNS_PROTOCOL_DNS: + assert(t->server); + dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); + break; + + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + dns_scope_packet_lost(t->scope, usec - t->start_usec); + break; + + default: + assert_not_reached("Invalid DNS protocol."); + } + + if (t->initial_jitter_scheduled) + t->initial_jitter_elapsed = true; + } + + log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); + + dns_transaction_retry(t, true); + return 0; +} + +static usec_t transaction_get_resend_timeout(DnsTransaction *t) { + assert(t); + assert(t->scope); + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_DNS: + assert(t->server); + return t->server->resend_timeout; + + case DNS_PROTOCOL_MDNS: + assert(t->n_attempts > 0); + return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; + + case DNS_PROTOCOL_LLMNR: + return t->scope->resend_timeout; + + default: + assert_not_reached("Invalid DNS protocol."); + } +} + +static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { + int r; + + assert(t); + + dns_transaction_stop_timeout(t); + + r = dns_scope_network_good(t->scope); + if (r < 0) + return r; + if (r == 0) { + dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); + return 0; + } + + if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { + dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); + return 0; + } + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { + /* If we already tried via a stream, then we don't + * retry on LLMNR. See RFC 4795, Section 2.7. */ + dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); + return 0; + } + + t->n_attempts++; + t->start_usec = ts; + + dns_transaction_reset_answer(t); + dns_transaction_flush_dnssec_transactions(t); + + /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ + if (t->scope->protocol == DNS_PROTOCOL_DNS) { + r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); + if (r < 0) + return r; + if (r > 0) { + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; + t->answer_authenticated = true; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + return 0; + } + + if (dns_name_is_root(dns_resource_key_name(t->key)) && + t->key->type == DNS_TYPE_DS) { + + /* Hmm, this is a request for the root DS? A + * DS RR doesn't exist in the root zone, and + * if our trust anchor didn't know it either, + * this means we cannot do any DNSSEC logic + * anymore. */ + + if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { + /* We are in downgrade mode. In this + * case, synthesize an unsigned empty + * response, so that the any lookup + * depending on this one can continue + * assuming there was no DS, and hence + * the root zone was unsigned. */ + + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; + t->answer_authenticated = false; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + } else + /* If we are not in downgrade mode, + * then fail the lookup, because we + * cannot reasonably answer it. There + * might be DS RRs, but we don't know + * them, and the DNS server won't tell + * them to us (and even if it would, + * we couldn't validate and trust them. */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); + + return 0; + } + } + + /* Check the zone, but only if this transaction is not used + * for probing or verifying a zone item. */ + if (set_isempty(t->notify_zone_items)) { + + r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); + if (r < 0) + return r; + if (r > 0) { + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_ZONE; + t->answer_authenticated = true; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + return 0; + } + } + + /* Check the cache, but only if this transaction is not used + * for probing or verifying a zone item. */ + if (set_isempty(t->notify_zone_items)) { + + /* Before trying the cache, let's make sure we figured out a + * server to use. Should this cause a change of server this + * might flush the cache. */ + dns_scope_get_dns_server(t->scope); + + /* Let's then prune all outdated entries */ + dns_cache_prune(&t->scope->cache); + + r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); + if (r < 0) + return r; + if (r > 0) { + t->answer_source = DNS_TRANSACTION_CACHE; + if (t->answer_rcode == DNS_RCODE_SUCCESS) + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + else + dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); + return 0; + } + } + + return 1; +} + +static int dns_transaction_make_packet_mdns(DnsTransaction *t) { + + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + bool add_known_answers = false; + DnsTransaction *other; + unsigned qdcount; + usec_t ts; + int r; + + assert(t); + assert(t->scope->protocol == DNS_PROTOCOL_MDNS); + + /* Discard any previously prepared packet, so we can start over and coalesce again */ + t->sent = dns_packet_unref(t->sent); + + r = dns_packet_new_query(&p, t->scope->protocol, 0, false); + if (r < 0) + return r; + + r = dns_packet_append_key(p, t->key, NULL); + if (r < 0) + return r; + + qdcount = 1; + + if (dns_key_is_shared(t->key)) + add_known_answers = true; + + /* + * For mDNS, we want to coalesce as many open queries in pending transactions into one single + * query packet on the wire as possible. To achieve that, we iterate through all pending transactions + * in our current scope, and see whether their timing contraints allow them to be sent. + */ + + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { + + /* Skip ourselves */ + if (other == t) + continue; + + if (other->state != DNS_TRANSACTION_PENDING) + continue; + + if (other->next_attempt_after > ts) + continue; + + if (qdcount >= UINT16_MAX) + break; + + r = dns_packet_append_key(p, other->key, NULL); + + /* + * If we can't stuff more questions into the packet, just give up. + * One of the 'other' transactions will fire later and take care of the rest. + */ + if (r == -EMSGSIZE) + break; + + if (r < 0) + return r; + + r = dns_transaction_prepare(other, ts); + if (r <= 0) + continue; + + ts += transaction_get_resend_timeout(other); + + r = sd_event_add_time( + other->scope->manager->event, + &other->timeout_event_source, + clock_boottime_or_monotonic(), + ts, 0, + on_transaction_timeout, other); + if (r < 0) + return r; + + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + + other->state = DNS_TRANSACTION_PENDING; + other->next_attempt_after = ts; + + qdcount++; + + if (dns_key_is_shared(other->key)) + add_known_answers = true; + } + + DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); + + /* Append known answer section if we're asking for any shared record */ + if (add_known_answers) { + r = dns_cache_export_shared_to_packet(&t->scope->cache, p); + if (r < 0) + return r; + } + + t->sent = p; + p = NULL; + + return 0; +} + +static int dns_transaction_make_packet(DnsTransaction *t) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + int r; + + assert(t); + + if (t->scope->protocol == DNS_PROTOCOL_MDNS) + return dns_transaction_make_packet_mdns(t); + + if (t->sent) + return 0; + + r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); + if (r < 0) + return r; + + r = dns_packet_append_key(p, t->key, NULL); + if (r < 0) + return r; + + DNS_PACKET_HEADER(p)->qdcount = htobe16(1); + DNS_PACKET_HEADER(p)->id = t->id; + + t->sent = p; + p = NULL; + + return 0; +} + +int dns_transaction_go(DnsTransaction *t) { + usec_t ts; + int r; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + assert(t); + + /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished + * now. */ + + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + r = dns_transaction_prepare(t, ts); + if (r <= 0) + return r; + + log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", + t->id, + dns_resource_key_to_string(t->key, key_str, sizeof key_str), + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + af_to_name_short(t->scope->family)); + + if (!t->initial_jitter_scheduled && + (t->scope->protocol == DNS_PROTOCOL_LLMNR || + t->scope->protocol == DNS_PROTOCOL_MDNS)) { + usec_t jitter, accuracy; + + /* RFC 4795 Section 2.7 suggests all queries should be + * delayed by a random time from 0 to JITTER_INTERVAL. */ + + t->initial_jitter_scheduled = true; + + random_bytes(&jitter, sizeof(jitter)); + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_LLMNR: + jitter %= LLMNR_JITTER_INTERVAL_USEC; + accuracy = LLMNR_JITTER_INTERVAL_USEC; + break; + + case DNS_PROTOCOL_MDNS: + jitter %= MDNS_JITTER_RANGE_USEC; + jitter += MDNS_JITTER_MIN_USEC; + accuracy = MDNS_JITTER_RANGE_USEC; + break; + default: + assert_not_reached("bad protocol"); + } + + r = sd_event_add_time( + t->scope->manager->event, + &t->timeout_event_source, + clock_boottime_or_monotonic(), + ts + jitter, accuracy, + on_transaction_timeout, t); + if (r < 0) + return r; + + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + + t->n_attempts = 0; + t->next_attempt_after = ts; + t->state = DNS_TRANSACTION_PENDING; + + log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); + return 0; + } + + /* Otherwise, we need to ask the network */ + r = dns_transaction_make_packet(t); + if (r < 0) + return r; + + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && + (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || + dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { + + /* RFC 4795, Section 2.4. says reverse lookups shall + * always be made via TCP on LLMNR */ + r = dns_transaction_open_tcp(t); + } else { + /* Try via UDP, and if that fails due to large size or lack of + * support try via TCP */ + r = dns_transaction_emit_udp(t); + if (r == -EMSGSIZE) + log_debug("Sending query via TCP since it is too large."); + if (r == -EAGAIN) + log_debug("Sending query via TCP since server doesn't support UDP."); + if (r == -EMSGSIZE || r == -EAGAIN) + r = dns_transaction_open_tcp(t); + } + + if (r == -ESRCH) { + /* No servers to send this to? */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); + return 0; + } + if (r == -EOPNOTSUPP) { + /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ + dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); + return 0; + } + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { + /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot + * answer this request with this protocol. */ + dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); + return 0; + } + if (r < 0) { + if (t->scope->protocol != DNS_PROTOCOL_DNS) + return r; + + /* Couldn't send? Try immediately again, with a new server */ + dns_scope_next_dns_server(t->scope); + + return dns_transaction_go(t); + } + + ts += transaction_get_resend_timeout(t); + + r = sd_event_add_time( + t->scope->manager->event, + &t->timeout_event_source, + clock_boottime_or_monotonic(), + ts, 0, + on_transaction_timeout, t); + if (r < 0) + return r; + + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + + t->state = DNS_TRANSACTION_PENDING; + t->next_attempt_after = ts; + + return 1; +} + +static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { + DnsTransaction *n; + Iterator i; + int r; + + assert(t); + assert(aux); + + /* Try to find cyclic dependencies between transaction objects */ + + if (t == aux) + return 1; + + SET_FOREACH(n, aux->dnssec_transactions, i) { + r = dns_transaction_find_cyclic(t, n); + if (r != 0) + return r; + } + + return 0; +} + +static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { + DnsTransaction *aux; + int r; + + assert(t); + assert(ret); + assert(key); + + aux = dns_scope_find_transaction(t->scope, key, true); + if (!aux) { + r = dns_transaction_new(&aux, t->scope, key); + if (r < 0) + return r; + } else { + if (set_contains(t->dnssec_transactions, aux)) { + *ret = aux; + return 0; + } + + r = dns_transaction_find_cyclic(t, aux); + if (r < 0) + return r; + if (r > 0) { + char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; + + log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", + aux->id, + dns_resource_key_to_string(t->key, s, sizeof s), + t->id, + dns_resource_key_to_string(aux->key, saux, sizeof saux)); + + return -ELOOP; + } + } + + r = set_ensure_allocated(&t->dnssec_transactions, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&aux->notify_transactions, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&aux->notify_transactions_done, NULL); + if (r < 0) + goto gc; + + r = set_put(t->dnssec_transactions, aux); + if (r < 0) + goto gc; + + r = set_put(aux->notify_transactions, t); + if (r < 0) { + (void) set_remove(t->dnssec_transactions, aux); + goto gc; + } + + *ret = aux; + return 1; + +gc: + dns_transaction_gc(aux); + return r; +} + +static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { + _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; + DnsTransaction *aux; + int r; + + assert(t); + assert(key); + + /* Try to get the data from the trust anchor */ + r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); + if (r < 0) + return r; + if (r > 0) { + r = dns_answer_extend(&t->validated_keys, a); + if (r < 0) + return r; + + return 0; + } + + /* This didn't work, ask for it via the network/cache then. */ + r = dns_transaction_add_dnssec_transaction(t, key, &aux); + if (r == -ELOOP) /* This would result in a cyclic dependency */ + return 0; + if (r < 0) + return r; + + if (aux->state == DNS_TRANSACTION_NULL) { + r = dns_transaction_go(aux); + if (r < 0) + return r; + } + + return 1; +} + +static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { + int r; + + assert(t); + + /* Check whether the specified name is in the NTA + * database, either in the global one, or the link-local + * one. */ + + r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); + if (r != 0) + return r; + + if (!t->scope->link) + return 0; + + return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); +} + +static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { + int r; + + assert(t); + + /* Checks whether the answer is negative, and lacks NSEC/NSEC3 + * RRs to prove it */ + + r = dns_transaction_has_positive_answer(t, NULL); + if (r < 0) + return r; + if (r > 0) + return false; + + /* Is this key explicitly listed as a negative trust anchor? + * If so, it's nothing we need to care about */ + r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + /* The answer does not contain any RRs that match to the + * question. If so, let's see if there are any NSEC/NSEC3 RRs + * included. If not, the answer is unsigned. */ + + r = dns_answer_contains_nsec_or_nsec3(t->answer); + if (r < 0) + return r; + if (r > 0) + return false; + + return true; +} + +static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { + int r; + + assert(t); + assert(rr); + + /* Check if the specified RR is the "primary" response, + * i.e. either matches the question precisely or is a + * CNAME/DNAME for it. */ + + r = dns_resource_key_match_rr(t->key, rr, NULL); + if (r != 0) + return r; + + return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); +} + +static bool dns_transaction_dnssec_supported(DnsTransaction *t) { + assert(t); + + /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon + * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ + + if (t->scope->protocol != DNS_PROTOCOL_DNS) + return false; + + /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well + * be supported, hence return true. */ + if (!t->server) + return true; + + /* Note that we do not check the feature level actually used for the transaction but instead the feature level + * the server is known to support currently, as the transaction feature level might be lower than what the + * server actually supports, since we might have downgraded this transaction's feature level because we got a + * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ + + return dns_server_dnssec_supported(t->server); +} + +static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ + + if (!dns_transaction_dnssec_supported(t)) + return false; + + SET_FOREACH(dt, t->dnssec_transactions, i) + if (!dns_transaction_dnssec_supported(dt)) + return false; + + return true; +} + +int dns_transaction_request_dnssec_keys(DnsTransaction *t) { + DnsResourceRecord *rr; + + int r; + + assert(t); + + /* + * Retrieve all auxiliary RRs for the answer we got, so that + * we can verify signatures or prove that RRs are rightfully + * unsigned. Specifically: + * + * - For RRSIG we get the matching DNSKEY + * - For DNSKEY we get the matching DS + * - For unsigned SOA/NS we get the matching DS + * - For unsigned CNAME/DNAME/DS we get the parent SOA RR + * - For other unsigned RRs we get the matching SOA RR + * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR + * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR + * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR + */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return 0; + if (t->answer_source != DNS_TRANSACTION_NETWORK) + return 0; /* We only need to validate stuff from the network */ + if (!dns_transaction_dnssec_supported(t)) + return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ + + DNS_ANSWER_FOREACH(rr, t->answer) { + + if (dns_type_is_pseudo(rr->key->type)) + continue; + + /* If this RR is in the negative trust anchor, we don't need to validate it. */ + r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r > 0) + continue; + + switch (rr->key->type) { + + case DNS_TYPE_RRSIG: { + /* For each RRSIG we request the matching DNSKEY */ + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; + + /* If this RRSIG is about a DNSKEY RR and the + * signer is the same as the owner, then we + * already have the DNSKEY, and we don't have + * to look for more. */ + if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { + r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r > 0) + continue; + } + + /* If the signer is not a parent of our + * original query, then this is about an + * auxiliary RRset, but not anything we asked + * for. In this case we aren't interested, + * because we don't want to request additional + * RRs for stuff we didn't really ask for, and + * also to avoid request loops, where + * additional RRs from one transaction result + * in another transaction whose additonal RRs + * point back to the original transaction, and + * we deadlock. */ + r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); + if (!dnskey) + return -ENOMEM; + + log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", + t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); + r = dns_transaction_request_dnssec_rr(t, dnskey); + if (r < 0) + return r; + break; + } + + case DNS_TYPE_DNSKEY: { + /* For each DNSKEY we request the matching DS */ + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; + + /* If the DNSKEY we are looking at is not for + * zone we are interested in, nor any of its + * parents, we aren't interested, and don't + * request it. After all, we don't want to end + * up in request loops, and want to keep + * additional traffic down. */ + + r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); + if (!ds) + return -ENOMEM; + + log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", + t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); + r = dns_transaction_request_dnssec_rr(t, ds); + if (r < 0) + return r; + + break; + } + + case DNS_TYPE_SOA: + case DNS_TYPE_NS: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; + + /* For an unsigned SOA or NS, try to acquire + * the matching DS RR, as we are at a zone cut + * then, and whether a DS exists tells us + * whether the zone is signed. Do so only if + * this RR matches our original question, + * however. */ + + r = dns_resource_key_match_rr(t->key, rr, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); + if (!ds) + return -ENOMEM; + + log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", + t->id, dns_resource_key_name(rr->key)); + r = dns_transaction_request_dnssec_rr(t, ds); + if (r < 0) + return r; + + break; + } + + case DNS_TYPE_DS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + const char *name; + + /* CNAMEs and DNAMEs cannot be located at a + * zone apex, hence ask for the parent SOA for + * unsigned CNAME/DNAME RRs, maybe that's the + * apex. But do all that only if this is + * actually a response to our original + * question. + * + * Similar for DS RRs, which are signed when + * the parent SOA is signed. */ + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + r = dns_answer_has_dname_for_cname(t->answer, rr); + if (r < 0) + return r; + if (r > 0) + continue; + + name = dns_resource_key_name(rr->key); + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + continue; + + soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); + if (!soa) + return -ENOMEM; + + log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", + t->id, dns_resource_key_name(rr->key)); + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + + break; + } + + default: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + + /* For other unsigned RRsets (including + * NSEC/NSEC3!), look for proof the zone is + * unsigned, by requesting the SOA RR of the + * zone. However, do so only if they are + * directly relevant to our original + * question. */ + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); + if (!soa) + return -ENOMEM; + + log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", + t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + break; + }} + } + + /* Above, we requested everything necessary to validate what + * we got. Now, let's request what we need to validate what we + * didn't get... */ + + r = dns_transaction_has_unsigned_negative_answer(t); + if (r < 0) + return r; + if (r > 0) { + const char *name; + uint16_t type = 0; + + name = dns_resource_key_name(t->key); + + /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this + * could also be used as indication that we are not at a zone apex, but in real world setups there are + * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even + * though they have further children. If this was a DS request, then it's signed when the parent zone + * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, + * to see if that is signed. */ + + if (t->key->type == DNS_TYPE_DS) { + r = dns_name_parent(&name); + if (r > 0) { + type = DNS_TYPE_SOA; + log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", + t->id, dns_resource_key_name(t->key)); + } else + name = NULL; + + } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { + + type = DNS_TYPE_DS; + log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", + t->id, dns_resource_key_name(t->key)); + + } else { + type = DNS_TYPE_SOA; + log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", + t->id, dns_resource_key_name(t->key)); + } + + if (name) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + + soa = dns_resource_key_new(t->key->class, type, name); + if (!soa) + return -ENOMEM; + + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + } + } + + return dns_transaction_dnssec_is_live(t); +} + +void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { + assert(t); + assert(source); + + /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, + we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If + the state is VALIDATING however, we should check if we are complete now. */ + + if (t->state == DNS_TRANSACTION_VALIDATING) + dns_transaction_process_dnssec(t); +} + +static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { + DnsResourceRecord *rr; + int ifindex, r; + + assert(t); + + /* Add all DNSKEY RRs from the answer that are validated by DS + * RRs from the list of validated keys to the list of + * validated keys. */ + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { + + r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); + if (r < 0) + return r; + if (r == 0) + continue; + + /* If so, the DNSKEY is validated too. */ + r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { + int r; + + assert(t); + assert(rr); + + /* Checks if the RR we are looking for must be signed with an + * RRSIG. This is used for positive responses. */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return false; + + if (dns_type_is_pseudo(rr->key->type)) + return -EINVAL; + + r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + switch (rr->key->type) { + + case DNS_TYPE_RRSIG: + /* RRSIGs are the signatures themselves, they need no signing. */ + return false; + + case DNS_TYPE_SOA: + case DNS_TYPE_NS: { + DnsTransaction *dt; + Iterator i; + + /* For SOA or NS RRs we look for a matching DS transaction */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_DS) + continue; + + r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found a DS transactions for the SOA/NS + * RRs we are looking at. If it discovered signed DS + * RRs, then we need to be signed, too. */ + + if (!dt->answer_authenticated) + return false; + + return dns_answer_match_key(dt->answer, dt->key, NULL); + } + + /* We found nothing that proves this is safe to leave + * this unauthenticated, hence ask inist on + * authentication. */ + return true; + } + + case DNS_TYPE_DS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: { + const char *parent = NULL; + DnsTransaction *dt; + Iterator i; + + /* + * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. + * + * DS RRs are signed if the parent is signed, hence also look at the parent SOA + */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_SOA) + continue; + + if (!parent) { + parent = dns_resource_key_name(rr->key); + r = dns_name_parent(&parent); + if (r < 0) + return r; + if (r == 0) { + if (rr->key->type == DNS_TYPE_DS) + return true; + + /* A CNAME/DNAME without a parent? That's sooo weird. */ + log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); + return -EBADMSG; + } + } + + r = dns_name_equal(dns_resource_key_name(dt->key), parent); + if (r < 0) + return r; + if (r == 0) + continue; + + return t->answer_authenticated; + } + + return true; + } + + default: { + DnsTransaction *dt; + Iterator i; + + /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_SOA) + continue; + + r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found the transaction that was supposed to find + * the SOA RR for us. It was successful, but found no + * RR for us. This means we are not at a zone cut. In + * this case, we require authentication if the SOA + * lookup was authenticated too. */ + return t->answer_authenticated; + } + + return true; + }} +} + +static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { + DnsTransaction *dt; + const char *tld; + Iterator i; + int r; + + /* If DNSSEC downgrade mode is on, checks whether the + * specified RR is one level below a TLD we have proven not to + * exist. In such a case we assume that this is a private + * domain, and permit it. + * + * This detects cases like the Fritz!Box router networks. Each + * Fritz!Box router serves a private "fritz.box" zone, in the + * non-existing TLD "box". Requests for the "fritz.box" domain + * are served by the router itself, while requests for the + * "box" domain will result in NXDOMAIN. + * + * Note that this logic is unable to detect cases where a + * router serves a private DNS zone directly under + * non-existing TLD. In such a case we cannot detect whether + * the TLD is supposed to exist or not, as all requests we + * make for it will be answered by the router's zone, and not + * by the root zone. */ + + assert(t); + + if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) + return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ + + tld = dns_resource_key_name(key); + r = dns_name_parent(&tld); + if (r < 0) + return r; + if (r == 0) + return false; /* Already the root domain */ + + if (!dns_name_is_single_label(tld)) + return false; + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != key->class) + continue; + + r = dns_name_equal(dns_resource_key_name(dt->key), tld); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found an auxiliary lookup we did for the TLD. If + * that returned with NXDOMAIN, we know the TLD didn't + * exist, and hence this might be a private zone. */ + + return dt->answer_rcode == DNS_RCODE_NXDOMAIN; + } + + return false; +} + +static int dns_transaction_requires_nsec(DnsTransaction *t) { + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + DnsTransaction *dt; + const char *name; + uint16_t type = 0; + Iterator i; + int r; + + assert(t); + + /* Checks if we need to insist on NSEC/NSEC3 RRs for proving + * this negative reply */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return false; + + if (dns_type_is_pseudo(t->key->type)) + return -EINVAL; + + r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + r = dns_transaction_in_private_tld(t, t->key); + if (r < 0) + return r; + if (r > 0) { + /* The lookup is from a TLD that is proven not to + * exist, and we are in downgrade mode, hence ignore + * that fact that we didn't get any NSEC RRs.*/ + + log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", + dns_resource_key_to_string(t->key, key_str, sizeof key_str)); + return false; + } + + name = dns_resource_key_name(t->key); + + if (t->key->type == DNS_TYPE_DS) { + + /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, + * hence check the parent SOA in this case. */ + + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + return true; + + type = DNS_TYPE_SOA; + + } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) + /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ + type = DNS_TYPE_DS; + else + /* For all other negative replies, check for the SOA lookup */ + type = DNS_TYPE_SOA; + + /* For all other RRs we check the SOA on the same level to see + * if it's signed. */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != t->key->class) + continue; + if (dt->key->type != type) + continue; + + r = dns_name_equal(dns_resource_key_name(dt->key), name); + if (r < 0) + return r; + if (r == 0) + continue; + + return dt->answer_authenticated; + } + + /* If in doubt, require NSEC/NSEC3 */ + return true; +} + +static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { + DnsResourceRecord *rrsig; + bool found = false; + int r; + + /* Checks whether any of the DNSKEYs used for the RRSIGs for + * the specified RRset is authenticated (i.e. has a matching + * DS RR). */ + + r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + DNS_ANSWER_FOREACH(rrsig, t->answer) { + DnsTransaction *dt; + Iterator i; + + r = dnssec_key_match_rrsig(rr->key, rrsig); + if (r < 0) + return r; + if (r == 0) + continue; + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + + if (dt->key->type == DNS_TYPE_DNSKEY) { + + r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + /* OK, we found an auxiliary DNSKEY + * lookup. If that lookup is + * authenticated, report this. */ + + if (dt->answer_authenticated) + return true; + + found = true; + + } else if (dt->key->type == DNS_TYPE_DS) { + + r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + /* OK, we found an auxiliary DS + * lookup. If that lookup is + * authenticated and non-zero, we + * won! */ + + if (!dt->answer_authenticated) + return false; + + return dns_answer_match_key(dt->answer, dt->key, NULL); + } + } + } + + return found ? false : -ENXIO; +} + +static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { + assert(t); + assert(rr); + + /* We know that the root domain is signed, hence if it appears + * not to be signed, there's a problem with the DNS server */ + + return rr->key->class == DNS_CLASS_IN && + dns_name_is_root(dns_resource_key_name(rr->key)); +} + +static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { + DnsResourceRecord *rr; + int r; + + assert(t); + + /* Maybe warn the user that we encountered a revoked DNSKEY + * for a key from our trust anchor. Note that we don't care + * whether the DNSKEY can be authenticated or not. It's + * sufficient if it is self-signed. */ + + DNS_ANSWER_FOREACH(rr, t->answer) { + r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { + bool changed; + int r; + + assert(t); + + /* Removes all DNSKEY/DS objects from t->validated_keys that + * our trust anchors database considers revoked. */ + + do { + DnsResourceRecord *rr; + + changed = false; + + DNS_ANSWER_FOREACH(rr, t->validated_keys) { + r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); + if (r < 0) + return r; + if (r > 0) { + r = dns_answer_remove_by_rr(&t->validated_keys, rr); + if (r < 0) + return r; + + assert(r > 0); + changed = true; + break; + } + } + } while (changed); + + return 0; +} + +static int dns_transaction_copy_validated(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + int r; + + assert(t); + + /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (DNS_TRANSACTION_IS_LIVE(dt->state)) + continue; + + if (!dt->answer_authenticated) + continue; + + r = dns_answer_extend(&t->validated_keys, dt->answer); + if (r < 0) + return r; + } + + return 0; +} + +typedef enum { + DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ + DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ + DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ +} Phase; + +static int dnssec_validate_records( + DnsTransaction *t, + Phase phase, + bool *have_nsec, + DnsAnswer **validated) { + + DnsResourceRecord *rr; + int r; + + /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ + + DNS_ANSWER_FOREACH(rr, t->answer) { + DnsResourceRecord *rrsig = NULL; + DnssecResult result; + + switch (rr->key->type) { + case DNS_TYPE_RRSIG: + continue; + + case DNS_TYPE_DNSKEY: + /* We validate DNSKEYs only in the DNSKEY and ALL phases */ + if (phase == DNSSEC_PHASE_NSEC) + continue; + break; + + case DNS_TYPE_NSEC: + case DNS_TYPE_NSEC3: + *have_nsec = true; + + /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ + if (phase == DNSSEC_PHASE_DNSKEY) + continue; + break; + + default: + /* We validate all other RRs only in the ALL phases */ + if (phase != DNSSEC_PHASE_ALL) + continue; + } + + r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); + if (r < 0) + return r; + + log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); + + if (result == DNSSEC_VALIDATED) { + + if (rr->key->type == DNS_TYPE_DNSKEY) { + /* If we just validated a DNSKEY RRset, then let's add these keys to + * the set of validated keys for this transaction. */ + + r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + /* Some of the DNSKEYs we just added might already have been revoked, + * remove them again in that case. */ + r = dns_transaction_invalidate_revoked_keys(t); + if (r < 0) + return r; + } + + /* Add the validated RRset to the new list of validated + * RRsets, and remove it from the unvalidated RRsets. + * We mark the RRset as authenticated and cacheable. */ + r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); + + /* Exit the loop, we dropped something from the answer, start from the beginning */ + return 1; + } + + /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as + * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, + * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ + if (phase != DNSSEC_PHASE_ALL) + continue; + + if (result == DNSSEC_VALIDATED_WILDCARD) { + bool authenticated = false; + const char *source; + + /* This RRset validated, but as a wildcard. This means we need + * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists.*/ + + /* First step, determine the source of synthesis */ + r = dns_resource_record_source(rrsig, &source); + if (r < 0) + return r; + + r = dnssec_test_positive_wildcard(*validated, + dns_resource_key_name(rr->key), + source, + rrsig->rrsig.signer, + &authenticated); + + /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ + if (r == 0) + result = DNSSEC_INVALID; + else { + r = dns_answer_move_by_key(validated, &t->answer, rr->key, + authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); + + /* Exit the loop, we dropped something from the answer, start from the beginning */ + return 1; + } + } + + if (result == DNSSEC_NO_SIGNATURE) { + r = dns_transaction_requires_rrsig(t, rr); + if (r < 0) + return r; + if (r == 0) { + /* Data does not require signing. In that case, just copy it over, + * but remember that this is by no means authenticated.*/ + r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); + return 1; + } + + r = dns_transaction_known_signed(t, rr); + if (r < 0) + return r; + if (r > 0) { + /* This is an RR we know has to be signed. If it isn't this means + * the server is not attaching RRSIGs, hence complain. */ + + dns_server_packet_rrsig_missing(t->server, t->current_feature_level); + + if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { + + /* Downgrading is OK? If so, just consider the information unsigned */ + + r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); + return 1; + } + + /* Otherwise, fail */ + t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; + return 0; + } + + r = dns_transaction_in_private_tld(t, rr->key); + if (r < 0) + return r; + if (r > 0) { + char s[DNS_RESOURCE_KEY_STRING_MAX]; + + /* The data is from a TLD that is proven not to exist, and we are in downgrade + * mode, hence ignore the fact that this was not signed. */ + + log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", + dns_resource_key_to_string(rr->key, s, sizeof s)); + + r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); + return 1; + } + } + + if (IN_SET(result, + DNSSEC_MISSING_KEY, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_UNSUPPORTED_ALGORITHM)) { + + r = dns_transaction_dnskey_authenticated(t, rr); + if (r < 0 && r != -ENXIO) + return r; + if (r == 0) { + /* The DNSKEY transaction was not authenticated, this means there's + * no DS for this, which means it's OK if no keys are found for this signature. */ + + r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); + return 1; + } + } + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r > 0) { + /* Look for a matching DNAME for this CNAME */ + r = dns_answer_has_dname_for_cname(t->answer, rr); + if (r < 0) + return r; + if (r == 0) { + /* Also look among the stuff we already validated */ + r = dns_answer_has_dname_for_cname(*validated, rr); + if (r < 0) + return r; + } + + if (r == 0) { + if (IN_SET(result, + DNSSEC_INVALID, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_NO_SIGNATURE)) + manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); + else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ + manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); + + /* This is a primary response to our question, and it failed validation. + * That's fatal. */ + t->answer_dnssec_result = result; + return 0; + } + + /* This is a primary response, but we do have a DNAME RR + * in the RR that can replay this CNAME, hence rely on + * that, and we can remove the CNAME in favour of it. */ + } + + /* This is just some auxiliary data. Just remove the RRset and continue. */ + r = dns_answer_remove_by_key(&t->answer, rr->key); + if (r < 0) + return r; + + /* We dropped something from the answer, start from the beginning. */ + return 1; + } + + return 2; /* Finito. */ +} + +int dns_transaction_validate_dnssec(DnsTransaction *t) { + _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; + Phase phase; + DnsAnswerFlags flags; + int r; + char key_str[DNS_RESOURCE_KEY_STRING_MAX]; + + assert(t); + + /* We have now collected all DS and DNSKEY RRs in + * t->validated_keys, let's see which RRs we can now + * authenticate with that. */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return 0; + + /* Already validated */ + if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) + return 0; + + /* Our own stuff needs no validation */ + if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_authenticated = true; + return 0; + } + + /* Cached stuff is not affected by validation. */ + if (t->answer_source != DNS_TRANSACTION_NETWORK) + return 0; + + if (!dns_transaction_dnssec_supported_full(t)) { + /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ + t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; + log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); + return 0; + } + + log_debug("Validating response from transaction %" PRIu16 " (%s).", + t->id, + dns_resource_key_to_string(t->key, key_str, sizeof key_str)); + + /* First, see if this response contains any revoked trust + * anchors we care about */ + r = dns_transaction_check_revoked_trust_anchors(t); + if (r < 0) + return r; + + /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ + r = dns_transaction_copy_validated(t); + if (r < 0) + return r; + + /* Second, see if there are DNSKEYs we already know a + * validated DS for. */ + r = dns_transaction_validate_dnskey_by_ds(t); + if (r < 0) + return r; + + /* Fourth, remove all DNSKEY and DS RRs again that our trust + * anchor says are revoked. After all we might have marked + * some keys revoked above, but they might still be lingering + * in our validated_keys list. */ + r = dns_transaction_invalidate_revoked_keys(t); + if (r < 0) + return r; + + phase = DNSSEC_PHASE_DNSKEY; + for (;;) { + bool have_nsec = false; + + r = dnssec_validate_records(t, phase, &have_nsec, &validated); + if (r <= 0) + return r; + + /* Try again as long as we managed to achieve something */ + if (r == 1) + continue; + + if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { + /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ + phase = DNSSEC_PHASE_NSEC; + continue; + } + + if (phase != DNSSEC_PHASE_ALL) { + /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. + * Note that in this third phase we start to remove RRs we couldn't validate. */ + phase = DNSSEC_PHASE_ALL; + continue; + } + + /* We're done */ + break; + } + + dns_answer_unref(t->answer); + t->answer = validated; + validated = NULL; + + /* At this point the answer only contains validated + * RRsets. Now, let's see if it actually answers the question + * we asked. If so, great! If it doesn't, then see if + * NSEC/NSEC3 can prove this. */ + r = dns_transaction_has_positive_answer(t, &flags); + if (r > 0) { + /* Yes, it answers the question! */ + + if (flags & DNS_ANSWER_AUTHENTICATED) { + /* The answer is fully authenticated, yay. */ + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_authenticated = true; + } else { + /* The answer is not fully authenticated. */ + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + } + + } else if (r == 0) { + DnssecNsecResult nr; + bool authenticated = false; + + /* Bummer! Let's check NSEC/NSEC3 */ + r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); + if (r < 0) + return r; + + switch (nr) { + + case DNSSEC_NSEC_NXDOMAIN: + /* NSEC proves the domain doesn't exist. Very good. */ + log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_NXDOMAIN; + t->answer_authenticated = authenticated; + + manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); + break; + + case DNSSEC_NSEC_NODATA: + /* NSEC proves that there's no data here, very good. */ + log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_authenticated = authenticated; + + manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); + break; + + case DNSSEC_NSEC_OPTOUT: + /* NSEC3 says the data might not be signed */ + log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); + break; + + case DNSSEC_NSEC_NO_RR: + /* No NSEC data? Bummer! */ + + r = dns_transaction_requires_nsec(t); + if (r < 0) + return r; + if (r > 0) { + t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; + manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); + } else { + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); + } + + break; + + case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: + /* We don't know the NSEC3 algorithm used? */ + t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; + manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); + break; + + case DNSSEC_NSEC_FOUND: + case DNSSEC_NSEC_CNAME: + /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ + t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; + manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); + break; + + default: + assert_not_reached("Unexpected NSEC result."); + } + } + + return 1; +} + +static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { + [DNS_TRANSACTION_NULL] = "null", + [DNS_TRANSACTION_PENDING] = "pending", + [DNS_TRANSACTION_VALIDATING] = "validating", + [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", + [DNS_TRANSACTION_SUCCESS] = "success", + [DNS_TRANSACTION_NO_SERVERS] = "no-servers", + [DNS_TRANSACTION_TIMEOUT] = "timeout", + [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", + [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", + [DNS_TRANSACTION_ERRNO] = "errno", + [DNS_TRANSACTION_ABORTED] = "aborted", + [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", + [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", + [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", + [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", + [DNS_TRANSACTION_NOT_FOUND] = "not-found", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); + +static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { + [DNS_TRANSACTION_NETWORK] = "network", + [DNS_TRANSACTION_CACHE] = "cache", + [DNS_TRANSACTION_ZONE] = "zone", + [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-transaction.h b/src/grp-resolve/systemd-resolved/resolved-dns-transaction.h new file mode 100644 index 0000000000..705336221d --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-transaction.h @@ -0,0 +1,182 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +typedef struct DnsTransaction DnsTransaction; +typedef enum DnsTransactionState DnsTransactionState; +typedef enum DnsTransactionSource DnsTransactionSource; + +enum DnsTransactionState { + DNS_TRANSACTION_NULL, + DNS_TRANSACTION_PENDING, + DNS_TRANSACTION_VALIDATING, + DNS_TRANSACTION_RCODE_FAILURE, + DNS_TRANSACTION_SUCCESS, + DNS_TRANSACTION_NO_SERVERS, + DNS_TRANSACTION_TIMEOUT, + DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, + DNS_TRANSACTION_INVALID_REPLY, + DNS_TRANSACTION_ERRNO, + DNS_TRANSACTION_ABORTED, + DNS_TRANSACTION_DNSSEC_FAILED, + DNS_TRANSACTION_NO_TRUST_ANCHOR, + DNS_TRANSACTION_RR_TYPE_UNSUPPORTED, + DNS_TRANSACTION_NETWORK_DOWN, + DNS_TRANSACTION_NOT_FOUND, /* like NXDOMAIN, but when LLMNR/TCP connections fail */ + _DNS_TRANSACTION_STATE_MAX, + _DNS_TRANSACTION_STATE_INVALID = -1 +}; + +#define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING) + +enum DnsTransactionSource { + DNS_TRANSACTION_NETWORK, + DNS_TRANSACTION_CACHE, + DNS_TRANSACTION_ZONE, + DNS_TRANSACTION_TRUST_ANCHOR, + _DNS_TRANSACTION_SOURCE_MAX, + _DNS_TRANSACTION_SOURCE_INVALID = -1 +}; + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-packet.h" +#include "basic-dns/resolved-dns-question.h" + +#include "resolved-dns-scope.h" +#include "resolved-dns-server.h" +#include "resolved-dns-stream.h" + +struct DnsTransaction { + DnsScope *scope; + + DnsResourceKey *key; + + DnsTransactionState state; + + uint16_t id; + + bool tried_stream:1; + + bool initial_jitter_scheduled:1; + bool initial_jitter_elapsed:1; + + bool clamp_ttl:1; + + DnsPacket *sent, *received; + + DnsAnswer *answer; + int answer_rcode; + DnssecResult answer_dnssec_result; + DnsTransactionSource answer_source; + uint32_t answer_nsec_ttl; + int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */ + + /* Indicates whether the primary answer is authenticated, + * i.e. whether the RRs from answer which directly match the + * question are authenticated, or, if there are none, whether + * the NODATA or NXDOMAIN case is. It says nothing about + * additional RRs listed in the answer, however they have + * their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit + * is defined different than the AD bit in DNS packets, as + * that covers more than just the actual primary answer. */ + bool answer_authenticated; + + /* Contains DNSKEY, DS, SOA RRs we already verified and need + * to authenticate this reply */ + DnsAnswer *validated_keys; + + usec_t start_usec; + usec_t next_attempt_after; + sd_event_source *timeout_event_source; + unsigned n_attempts; + + /* UDP connection logic, if we need it */ + int dns_udp_fd; + sd_event_source *dns_udp_event_source; + + /* TCP connection logic, if we need it */ + DnsStream *stream; + + /* The active server */ + DnsServer *server; + + /* The features of the DNS server at time of transaction start */ + DnsServerFeatureLevel current_feature_level; + + /* If we got SERVFAIL back, we retry the lookup, using a lower feature level than we used before. */ + DnsServerFeatureLevel clamp_feature_level; + + /* Query candidates this transaction is referenced by and that + * shall be notified about this specific transaction + * completing. */ + Set *notify_query_candidates, *notify_query_candidates_done; + + /* Zone items this transaction is referenced by and that shall + * be notified about completion. */ + Set *notify_zone_items, *notify_zone_items_done; + + /* Other transactions that this transactions is referenced by + * and that shall be notified about completion. This is used + * when transactions want to validate their RRsets, but need + * another DNSKEY or DS RR to do so. */ + Set *notify_transactions, *notify_transactions_done; + + /* The opposite direction: the transactions this transaction + * created in order to request DNSKEY or DS RRs. */ + Set *dnssec_transactions; + + unsigned block_gc; + + LIST_FIELDS(DnsTransaction, transactions_by_scope); +}; + +int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key); +DnsTransaction* dns_transaction_free(DnsTransaction *t); + +bool dns_transaction_gc(DnsTransaction *t); +int dns_transaction_go(DnsTransaction *t); + +void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p); +void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state); + +void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source); +int dns_transaction_validate_dnssec(DnsTransaction *t); +int dns_transaction_request_dnssec_keys(DnsTransaction *t); + +const char* dns_transaction_state_to_string(DnsTransactionState p) _const_; +DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_; + +const char* dns_transaction_source_to_string(DnsTransactionSource p) _const_; +DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_; + +/* LLMNR Jitter interval, see RFC 4795 Section 7 */ +#define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC) + +/* mDNS Jitter interval, see RFC 6762 Section 5.2 */ +#define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC) +#define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC) + +/* Maximum attempts to send DNS requests, across all DNS servers */ +#define DNS_TRANSACTION_ATTEMPTS_MAX 16 + +/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ +#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 + +#define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX) diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.c b/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.c new file mode 100644 index 0000000000..cb45136788 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.c @@ -0,0 +1,747 @@ +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-messages.h> + +#include "basic-dns/resolved-dns-dnssec.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/conf-files.h" +#include "systemd-basic/def.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/hexdecoct.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/set.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-trust-anchor.h" + +static const char trust_anchor_dirs[] = CONF_PATHS_NULSTR("dnssec-trust-anchors.d"); + +/* The DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved December 2015 */ +static const uint8_t root_digest[] = + { 0x49, 0xAA, 0xC1, 0x1D, 0x7B, 0x6F, 0x64, 0x46, 0x70, 0x2E, 0x54, 0xA1, 0x60, 0x73, 0x71, 0x60, + 0x7A, 0x1A, 0x41, 0x85, 0x52, 0x00, 0xFD, 0x2C, 0xE1, 0xCD, 0xDE, 0x32, 0xF2, 0x4E, 0x8F, 0xB5 }; + +static bool dns_trust_anchor_knows_domain_positive(DnsTrustAnchor *d, const char *name) { + assert(d); + + /* Returns true if there's an entry for the specified domain + * name in our trust anchor */ + + return + hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DNSKEY, name)) || + hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name)); +} + +static int dns_trust_anchor_add_builtin_positive(DnsTrustAnchor *d) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; + + assert(d); + + r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); + if (r < 0) + return r; + + /* Only add the built-in trust anchor if there's neither a DS + * nor a DNSKEY defined for the root domain. That way users + * have an easy way to override the root domain DS/DNSKEY + * data. */ + if (dns_trust_anchor_knows_domain_positive(d, ".")) + return 0; + + /* Add the RR from https://data.iana.org/root-anchors/root-anchors.xml */ + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, ""); + if (!rr) + return -ENOMEM; + + rr->ds.key_tag = 19036; + rr->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rr->ds.digest_type = DNSSEC_DIGEST_SHA256; + rr->ds.digest_size = sizeof(root_digest); + rr->ds.digest = memdup(root_digest, rr->ds.digest_size); + if (!rr->ds.digest) + return -ENOMEM; + + answer = dns_answer_new(1); + if (!answer) + return -ENOMEM; + + r = dns_answer_add(answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + r = hashmap_put(d->positive_by_key, rr->key, answer); + if (r < 0) + return r; + + answer = NULL; + return 0; +} + +static int dns_trust_anchor_add_builtin_negative(DnsTrustAnchor *d) { + + static const char private_domains[] = + /* RFC 6761 says that .test is a special domain for + * testing and not to be installed in the root zone */ + "test\0" + + /* RFC 6761 says that these reverse IP lookup ranges + * are for private addresses, and hence should not + * show up in the root zone */ + "10.in-addr.arpa\0" + "16.172.in-addr.arpa\0" + "17.172.in-addr.arpa\0" + "18.172.in-addr.arpa\0" + "19.172.in-addr.arpa\0" + "20.172.in-addr.arpa\0" + "21.172.in-addr.arpa\0" + "22.172.in-addr.arpa\0" + "23.172.in-addr.arpa\0" + "24.172.in-addr.arpa\0" + "25.172.in-addr.arpa\0" + "26.172.in-addr.arpa\0" + "27.172.in-addr.arpa\0" + "28.172.in-addr.arpa\0" + "29.172.in-addr.arpa\0" + "30.172.in-addr.arpa\0" + "31.172.in-addr.arpa\0" + "168.192.in-addr.arpa\0" + + /* The same, but for IPv6. */ + "d.f.ip6.arpa\0" + + /* RFC 6762 reserves the .local domain for Multicast + * DNS, it hence cannot appear in the root zone. (Note + * that we by default do not route .local traffic to + * DNS anyway, except when a configured search domain + * suggests so.) */ + "local\0" + + /* These two are well known, popular private zone + * TLDs, that are blocked from delegation, according + * to: + * http://icannwiki.com/Name_Collision#NGPC_Resolution + * + * There's also ongoing work on making this official + * in an RRC: + * https://www.ietf.org/archive/id/draft-chapin-additional-reserved-tlds-02.txt */ + "home\0" + "corp\0" + + /* The following four TLDs are suggested for private + * zones in RFC 6762, Appendix G, and are hence very + * unlikely to be made official TLDs any day soon */ + "lan\0" + "intranet\0" + "internal\0" + "private\0"; + + const char *name; + int r; + + assert(d); + + /* Only add the built-in trust anchor if there's no negative + * trust anchor defined at all. This enables easy overriding + * of negative trust anchors. */ + + if (set_size(d->negative_by_name) > 0) + return 0; + + r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); + if (r < 0) + return r; + + /* We add a couple of domains as default negative trust + * anchors, where it's very unlikely they will be installed in + * the root zone. If they exist they must be private, and thus + * unsigned. */ + + NULSTR_FOREACH(name, private_domains) { + + if (dns_trust_anchor_knows_domain_positive(d, name)) + continue; + + r = set_put_strdup(d->negative_by_name, name); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_free_ char *domain = NULL, *class = NULL, *type = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnsAnswer *old_answer = NULL; + const char *p = s; + int r; + + assert(d); + assert(line); + + r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); + if (r < 0) + return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line); + + if (!dns_name_is_valid(domain)) { + log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); + return -EINVAL; + } + + r = extract_many_words(&p, NULL, 0, &class, &type, NULL); + if (r < 0) + return log_warning_errno(r, "Unable to parse class and type in line %s:%u: %m", path, line); + if (r != 2) { + log_warning("Missing class or type in line %s:%u", path, line); + return -EINVAL; + } + + if (!strcaseeq(class, "IN")) { + log_warning("RR class %s is not supported, ignoring line %s:%u.", class, path, line); + return -EINVAL; + } + + if (strcaseeq(type, "DS")) { + _cleanup_free_ char *key_tag = NULL, *algorithm = NULL, *digest_type = NULL, *digest = NULL; + _cleanup_free_ void *dd = NULL; + uint16_t kt; + int a, dt; + size_t l; + + r = extract_many_words(&p, NULL, 0, &key_tag, &algorithm, &digest_type, &digest, NULL); + if (r < 0) { + log_warning_errno(r, "Failed to parse DS parameters on line %s:%u: %m", path, line); + return -EINVAL; + } + if (r != 4) { + log_warning("Missing DS parameters on line %s:%u", path, line); + return -EINVAL; + } + + r = safe_atou16(key_tag, &kt); + if (r < 0) + return log_warning_errno(r, "Failed to parse DS key tag %s on line %s:%u: %m", key_tag, path, line); + + a = dnssec_algorithm_from_string(algorithm); + if (a < 0) { + log_warning("Failed to parse DS algorithm %s on line %s:%u", algorithm, path, line); + return -EINVAL; + } + + dt = dnssec_digest_from_string(digest_type); + if (dt < 0) { + log_warning("Failed to parse DS digest type %s on line %s:%u", digest_type, path, line); + return -EINVAL; + } + + r = unhexmem(digest, strlen(digest), &dd, &l); + if (r < 0) { + log_warning("Failed to parse DS digest %s on line %s:%u", digest, path, line); + return -EINVAL; + } + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, domain); + if (!rr) + return log_oom(); + + rr->ds.key_tag = kt; + rr->ds.algorithm = a; + rr->ds.digest_type = dt; + rr->ds.digest_size = l; + rr->ds.digest = dd; + dd = NULL; + + } else if (strcaseeq(type, "DNSKEY")) { + _cleanup_free_ char *flags = NULL, *protocol = NULL, *algorithm = NULL, *key = NULL; + _cleanup_free_ void *k = NULL; + uint16_t f; + size_t l; + int a; + + r = extract_many_words(&p, NULL, 0, &flags, &protocol, &algorithm, &key, NULL); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY parameters on line %s:%u: %m", path, line); + if (r != 4) { + log_warning("Missing DNSKEY parameters on line %s:%u", path, line); + return -EINVAL; + } + + if (!streq(protocol, "3")) { + log_warning("DNSKEY Protocol is not 3 on line %s:%u", path, line); + return -EINVAL; + } + + r = safe_atou16(flags, &f); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY flags field %s on line %s:%u", flags, path, line); + if ((f & DNSKEY_FLAG_ZONE_KEY) == 0) { + log_warning("DNSKEY lacks zone key bit set on line %s:%u", path, line); + return -EINVAL; + } + if ((f & DNSKEY_FLAG_REVOKE)) { + log_warning("DNSKEY is already revoked on line %s:%u", path, line); + return -EINVAL; + } + + a = dnssec_algorithm_from_string(algorithm); + if (a < 0) { + log_warning("Failed to parse DNSKEY algorithm %s on line %s:%u", algorithm, path, line); + return -EINVAL; + } + + r = unbase64mem(key, strlen(key), &k, &l); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY key data %s on line %s:%u", key, path, line); + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, domain); + if (!rr) + return log_oom(); + + rr->dnskey.flags = f; + rr->dnskey.protocol = 3; + rr->dnskey.algorithm = a; + rr->dnskey.key_size = l; + rr->dnskey.key = k; + k = NULL; + + } else { + log_warning("RR type %s is not supported, ignoring line %s:%u.", type, path, line); + return -EINVAL; + } + + if (!isempty(p)) { + log_warning("Trailing garbage on line %s:%u, ignoring line.", path, line); + return -EINVAL; + } + + r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); + if (r < 0) + return log_oom(); + + old_answer = hashmap_get(d->positive_by_key, rr->key); + answer = dns_answer_ref(old_answer); + + r = dns_answer_add_extend(&answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return log_error_errno(r, "Failed to add trust anchor RR: %m"); + + r = hashmap_replace(d->positive_by_key, rr->key, answer); + if (r < 0) + return log_error_errno(r, "Failed to add answer to trust anchor: %m"); + + old_answer = dns_answer_unref(old_answer); + answer = NULL; + + return 0; +} + +static int dns_trust_anchor_load_negative(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { + _cleanup_free_ char *domain = NULL; + const char *p = s; + int r; + + assert(d); + assert(line); + + r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); + if (r < 0) + return log_warning_errno(r, "Unable to parse line %s:%u: %m", path, line); + + if (!dns_name_is_valid(domain)) { + log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); + return -EINVAL; + } + + if (!isempty(p)) { + log_warning("Trailing garbage at line %s:%u, ignoring line.", path, line); + return -EINVAL; + } + + r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); + if (r < 0) + return log_oom(); + + r = set_put(d->negative_by_name, domain); + if (r < 0) + return log_oom(); + if (r > 0) + domain = NULL; + + return 0; +} + +static int dns_trust_anchor_load_files( + DnsTrustAnchor *d, + const char *suffix, + int (*loader)(DnsTrustAnchor *d, const char *path, unsigned n, const char *line)) { + + _cleanup_strv_free_ char **files = NULL; + char **f; + int r; + + assert(d); + assert(suffix); + assert(loader); + + r = conf_files_list_nulstr(&files, suffix, NULL, trust_anchor_dirs); + if (r < 0) + return log_error_errno(r, "Failed to enumerate %s trust anchor files: %m", suffix); + + STRV_FOREACH(f, files) { + _cleanup_fclose_ FILE *g = NULL; + char line[LINE_MAX]; + unsigned n = 0; + + g = fopen(*f, "r"); + if (!g) { + if (errno == ENOENT) + continue; + + log_warning_errno(errno, "Failed to open %s: %m", *f); + continue; + } + + FOREACH_LINE(line, g, log_warning_errno(errno, "Failed to read %s, ignoring: %m", *f)) { + char *l; + + n++; + + l = strstrip(line); + if (isempty(l)) + continue; + + if (*l == ';') + continue; + + (void) loader(d, *f, n, l); + } + } + + return 0; +} + +static int domain_name_cmp(const void *a, const void *b) { + char **x = (char**) a, **y = (char**) b; + + return dns_name_compare_func(*x, *y); +} + +static int dns_trust_anchor_dump(DnsTrustAnchor *d) { + DnsAnswer *a; + Iterator i; + + assert(d); + + if (hashmap_isempty(d->positive_by_key)) + log_info("No positive trust anchors defined."); + else { + log_info("Positive Trust Anchors:"); + HASHMAP_FOREACH(a, d->positive_by_key, i) { + DnsResourceRecord *rr; + + DNS_ANSWER_FOREACH(rr, a) + log_info("%s", dns_resource_record_to_string(rr)); + } + } + + if (set_isempty(d->negative_by_name)) + log_info("No negative trust anchors defined."); + else { + _cleanup_free_ char **l = NULL, *j = NULL; + + l = set_get_strv(d->negative_by_name); + if (!l) + return log_oom(); + + qsort_safe(l, set_size(d->negative_by_name), sizeof(char*), domain_name_cmp); + + j = strv_join(l, " "); + if (!j) + return log_oom(); + + log_info("Negative trust anchors: %s", j); + } + + return 0; +} + +int dns_trust_anchor_load(DnsTrustAnchor *d) { + int r; + + assert(d); + + /* If loading things from disk fails, we don't consider this fatal */ + (void) dns_trust_anchor_load_files(d, ".positive", dns_trust_anchor_load_positive); + (void) dns_trust_anchor_load_files(d, ".negative", dns_trust_anchor_load_negative); + + /* However, if the built-in DS fails, then we have a problem. */ + r = dns_trust_anchor_add_builtin_positive(d); + if (r < 0) + return log_error_errno(r, "Failed to add built-in positive trust anchor: %m"); + + r = dns_trust_anchor_add_builtin_negative(d); + if (r < 0) + return log_error_errno(r, "Failed to add built-in negative trust anchor: %m"); + + dns_trust_anchor_dump(d); + + return 0; +} + +void dns_trust_anchor_flush(DnsTrustAnchor *d) { + DnsAnswer *a; + DnsResourceRecord *rr; + + assert(d); + + while ((a = hashmap_steal_first(d->positive_by_key))) + dns_answer_unref(a); + d->positive_by_key = hashmap_free(d->positive_by_key); + + while ((rr = set_steal_first(d->revoked_by_rr))) + dns_resource_record_unref(rr); + d->revoked_by_rr = set_free(d->revoked_by_rr); + + d->negative_by_name = set_free_free(d->negative_by_name); +} + +int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey *key, DnsAnswer **ret) { + DnsAnswer *a; + + assert(d); + assert(key); + assert(ret); + + /* We only serve DS and DNSKEY RRs. */ + if (!IN_SET(key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) + return 0; + + a = hashmap_get(d->positive_by_key, key); + if (!a) + return 0; + + *ret = dns_answer_ref(a); + return 1; +} + +int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name) { + assert(d); + assert(name); + + return set_contains(d->negative_by_name, name); +} + +static int dns_trust_anchor_revoked_put(DnsTrustAnchor *d, DnsResourceRecord *rr) { + int r; + + assert(d); + + r = set_ensure_allocated(&d->revoked_by_rr, &dns_resource_record_hash_ops); + if (r < 0) + return r; + + r = set_put(d->revoked_by_rr, rr); + if (r < 0) + return r; + if (r > 0) + dns_resource_record_ref(rr); + + return r; +} + +static int dns_trust_anchor_remove_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { + _cleanup_(dns_answer_unrefp) DnsAnswer *new_answer = NULL; + DnsAnswer *old_answer; + int r; + + /* Remember that this is a revoked trust anchor RR */ + r = dns_trust_anchor_revoked_put(d, rr); + if (r < 0) + return r; + + /* Remove this from the positive trust anchor */ + old_answer = hashmap_get(d->positive_by_key, rr->key); + if (!old_answer) + return 0; + + new_answer = dns_answer_ref(old_answer); + + r = dns_answer_remove_by_rr(&new_answer, rr); + if (r <= 0) + return r; + + /* We found the key! Warn the user */ + log_struct(LOG_WARNING, + LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_TRUST_ANCHOR_REVOKED), + LOG_MESSAGE("DNSSEC Trust anchor %s has been revoked. Please update the trust anchor, or upgrade your operating system."), strna(dns_resource_record_to_string(rr)), + "TRUST_ANCHOR=%s", dns_resource_record_to_string(rr), + NULL); + + if (dns_answer_size(new_answer) <= 0) { + assert_se(hashmap_remove(d->positive_by_key, rr->key) == old_answer); + dns_answer_unref(old_answer); + return 1; + } + + r = hashmap_replace(d->positive_by_key, new_answer->items[0].rr->key, new_answer); + if (r < 0) + return r; + + new_answer = NULL; + dns_answer_unref(old_answer); + return 1; +} + +static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceRecord *revoked_dnskey) { + DnsAnswer *a; + int r; + + assert(d); + assert(revoked_dnskey); + assert(revoked_dnskey->key->type == DNS_TYPE_DNSKEY); + assert(revoked_dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE); + + a = hashmap_get(d->positive_by_key, revoked_dnskey->key); + if (a) { + DnsResourceRecord *anchor; + + /* First, look for the precise DNSKEY in our trust anchor database */ + + DNS_ANSWER_FOREACH(anchor, a) { + + if (anchor->dnskey.protocol != revoked_dnskey->dnskey.protocol) + continue; + + if (anchor->dnskey.algorithm != revoked_dnskey->dnskey.algorithm) + continue; + + if (anchor->dnskey.key_size != revoked_dnskey->dnskey.key_size) + continue; + + /* Note that we allow the REVOKE bit to be + * different! It will be set in the revoked + * key, but unset in our version of it */ + if (((anchor->dnskey.flags ^ revoked_dnskey->dnskey.flags) | DNSKEY_FLAG_REVOKE) != DNSKEY_FLAG_REVOKE) + continue; + + if (memcmp(anchor->dnskey.key, revoked_dnskey->dnskey.key, anchor->dnskey.key_size) != 0) + continue; + + dns_trust_anchor_remove_revoked(d, anchor); + break; + } + } + + a = hashmap_get(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(revoked_dnskey->key->class, DNS_TYPE_DS, dns_resource_key_name(revoked_dnskey->key))); + if (a) { + DnsResourceRecord *anchor; + + /* Second, look for DS RRs matching this DNSKEY in our trust anchor database */ + + DNS_ANSWER_FOREACH(anchor, a) { + + /* We set mask_revoke to true here, since our + * DS fingerprint will be the one of the + * unrevoked DNSKEY, but the one we got passed + * here has the bit set. */ + r = dnssec_verify_dnskey_by_ds(revoked_dnskey, anchor, true); + if (r < 0) + return r; + if (r == 0) + continue; + + dns_trust_anchor_remove_revoked(d, anchor); + break; + } + } + + return 0; +} + +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) { + DnsResourceRecord *rrsig; + int r; + + assert(d); + assert(dnskey); + + /* Looks if "dnskey" is a self-signed RR that has been revoked + * and matches one of our trust anchor entries. If so, removes + * it from the trust anchor and returns > 0. */ + + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return 0; + + /* Is this DNSKEY revoked? */ + if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) + return 0; + + /* Could this be interesting to us at all? If not, + * there's no point in looking for and verifying a + * self-signed RRSIG. */ + if (!dns_trust_anchor_knows_domain_positive(d, dns_resource_key_name(dnskey->key))) + return 0; + + /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */ + DNS_ANSWER_FOREACH(rrsig, rrs) { + DnssecResult result; + + if (rrsig->key->type != DNS_TYPE_RRSIG) + continue; + + r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result); + if (r < 0) + return r; + if (result != DNSSEC_VALIDATED) + continue; + + /* Bingo! This is a revoked self-signed DNSKEY. Let's + * see if this precise one exists in our trust anchor + * database, too. */ + r = dns_trust_anchor_check_revoked_one(d, dnskey); + if (r < 0) + return r; + + return 1; + } + + return 0; +} + +int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { + assert(d); + + if (!IN_SET(rr->key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) + return 0; + + return set_contains(d->revoked_by_rr, rr); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.h b/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.h new file mode 100644 index 0000000000..9039bd7aa3 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-trust-anchor.h @@ -0,0 +1,43 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-rr.h" +#include "systemd-basic/hashmap.h" + +typedef struct DnsTrustAnchor DnsTrustAnchor; + +/* This contains a fixed database mapping domain names to DS or DNSKEY records. */ + +struct DnsTrustAnchor { + Hashmap *positive_by_key; + Set *negative_by_name; + Set *revoked_by_rr; +}; + +int dns_trust_anchor_load(DnsTrustAnchor *d); +void dns_trust_anchor_flush(DnsTrustAnchor *d); + +int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey* key, DnsAnswer **answer); +int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name); + +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs); +int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr); diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-zone.c b/src/grp-resolve/systemd-resolved/resolved-dns-zone.c new file mode 100644 index 0000000000..723df26454 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-zone.c @@ -0,0 +1,665 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-packet.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/list.h" +#include "systemd-basic/string-util.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-dns-zone.h" + +/* Never allow more than 1K entries */ +#define ZONE_MAX 1024 + +void dns_zone_item_probe_stop(DnsZoneItem *i) { + DnsTransaction *t; + assert(i); + + if (!i->probe_transaction) + return; + + t = i->probe_transaction; + i->probe_transaction = NULL; + + set_remove(t->notify_zone_items, i); + set_remove(t->notify_zone_items_done, i); + dns_transaction_gc(t); +} + +static void dns_zone_item_free(DnsZoneItem *i) { + if (!i) + return; + + dns_zone_item_probe_stop(i); + dns_resource_record_unref(i->rr); + + free(i); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsZoneItem*, dns_zone_item_free); + +static void dns_zone_item_remove_and_free(DnsZone *z, DnsZoneItem *i) { + DnsZoneItem *first; + + assert(z); + + if (!i) + return; + + first = hashmap_get(z->by_key, i->rr->key); + LIST_REMOVE(by_key, first, i); + if (first) + assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0); + else + hashmap_remove(z->by_key, i->rr->key); + + first = hashmap_get(z->by_name, dns_resource_key_name(i->rr->key)); + LIST_REMOVE(by_name, first, i); + if (first) + assert_se(hashmap_replace(z->by_name, dns_resource_key_name(first->rr->key), first) >= 0); + else + hashmap_remove(z->by_name, dns_resource_key_name(i->rr->key)); + + dns_zone_item_free(i); +} + +void dns_zone_flush(DnsZone *z) { + DnsZoneItem *i; + + assert(z); + + while ((i = hashmap_first(z->by_key))) + dns_zone_item_remove_and_free(z, i); + + assert(hashmap_size(z->by_key) == 0); + assert(hashmap_size(z->by_name) == 0); + + z->by_key = hashmap_free(z->by_key); + z->by_name = hashmap_free(z->by_name); +} + +static DnsZoneItem* dns_zone_get(DnsZone *z, DnsResourceRecord *rr) { + DnsZoneItem *i; + + assert(z); + assert(rr); + + LIST_FOREACH(by_key, i, hashmap_get(z->by_key, rr->key)) + if (dns_resource_record_equal(i->rr, rr) > 0) + return i; + + return NULL; +} + +void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr) { + DnsZoneItem *i; + + assert(z); + assert(rr); + + i = dns_zone_get(z, rr); + if (i) + dns_zone_item_remove_and_free(z, i); +} + +static int dns_zone_init(DnsZone *z) { + int r; + + assert(z); + + r = hashmap_ensure_allocated(&z->by_key, &dns_resource_key_hash_ops); + if (r < 0) + return r; + + r = hashmap_ensure_allocated(&z->by_name, &dns_name_hash_ops); + if (r < 0) + return r; + + return 0; +} + +static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) { + DnsZoneItem *first; + int r; + + first = hashmap_get(z->by_key, i->rr->key); + if (first) { + LIST_PREPEND(by_key, first, i); + assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0); + } else { + r = hashmap_put(z->by_key, i->rr->key, i); + if (r < 0) + return r; + } + + first = hashmap_get(z->by_name, dns_resource_key_name(i->rr->key)); + if (first) { + LIST_PREPEND(by_name, first, i); + assert_se(hashmap_replace(z->by_name, dns_resource_key_name(first->rr->key), first) >= 0); + } else { + r = hashmap_put(z->by_name, dns_resource_key_name(i->rr->key), i); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_zone_item_probe_start(DnsZoneItem *i) { + DnsTransaction *t; + int r; + + assert(i); + + if (i->probe_transaction) + return 0; + + t = dns_scope_find_transaction(i->scope, &DNS_RESOURCE_KEY_CONST(i->rr->key->class, DNS_TYPE_ANY, dns_resource_key_name(i->rr->key)), false); + if (!t) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + key = dns_resource_key_new(i->rr->key->class, DNS_TYPE_ANY, dns_resource_key_name(i->rr->key)); + if (!key) + return -ENOMEM; + + r = dns_transaction_new(&t, i->scope, key); + if (r < 0) + return r; + } + + r = set_ensure_allocated(&t->notify_zone_items, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&t->notify_zone_items_done, NULL); + if (r < 0) + goto gc; + + r = set_put(t->notify_zone_items, i); + if (r < 0) + goto gc; + + i->probe_transaction = t; + + if (t->state == DNS_TRANSACTION_NULL) { + + i->block_ready++; + r = dns_transaction_go(t); + i->block_ready--; + + if (r < 0) { + dns_zone_item_probe_stop(i); + return r; + } + } + + dns_zone_item_notify(i); + return 0; + +gc: + dns_transaction_gc(t); + return r; +} + +int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe) { + _cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL; + DnsZoneItem *existing; + int r; + + assert(z); + assert(s); + assert(rr); + + if (dns_class_is_pseudo(rr->key->class)) + return -EINVAL; + if (dns_type_is_pseudo(rr->key->type)) + return -EINVAL; + + existing = dns_zone_get(z, rr); + if (existing) + return 0; + + r = dns_zone_init(z); + if (r < 0) + return r; + + i = new0(DnsZoneItem, 1); + if (!i) + return -ENOMEM; + + i->scope = s; + i->rr = dns_resource_record_ref(rr); + i->probing_enabled = probe; + + r = dns_zone_link_item(z, i); + if (r < 0) + return r; + + if (probe) { + DnsZoneItem *first, *j; + bool established = false; + + /* Check if there's already an RR with the same name + * established. If so, it has been probed already, and + * we don't ned to probe again. */ + + LIST_FIND_HEAD(by_name, i, first); + LIST_FOREACH(by_name, j, first) { + if (i == j) + continue; + + if (j->state == DNS_ZONE_ITEM_ESTABLISHED) + established = true; + } + + if (established) + i->state = DNS_ZONE_ITEM_ESTABLISHED; + else { + i->state = DNS_ZONE_ITEM_PROBING; + + r = dns_zone_item_probe_start(i); + if (r < 0) { + dns_zone_item_remove_and_free(z, i); + i = NULL; + return r; + } + } + } else + i->state = DNS_ZONE_ITEM_ESTABLISHED; + + i = NULL; + return 0; +} + +int dns_zone_lookup(DnsZone *z, DnsResourceKey *key, int ifindex, DnsAnswer **ret_answer, DnsAnswer **ret_soa, bool *ret_tentative) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; + unsigned n_answer = 0; + DnsZoneItem *j, *first; + bool tentative = true, need_soa = false; + int r; + + /* Note that we don't actually need the ifindex for anything. However when it is passed we'll initialize the + * ifindex field in the answer with it */ + + assert(z); + assert(key); + assert(ret_answer); + + /* First iteration, count what we have */ + + if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { + bool found = false, added = false; + int k; + + /* If this is a generic match, then we have to + * go through the list by the name and look + * for everything manually */ + + first = hashmap_get(z->by_name, dns_resource_key_name(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + + k = dns_resource_key_match_rr(key, j->rr, NULL); + if (k < 0) + return k; + if (k > 0) { + n_answer++; + added = true; + } + + } + + if (found && !added) + need_soa = true; + + } else { + bool found = false; + + /* If this is a specific match, then look for + * the right key immediately */ + + first = hashmap_get(z->by_key, key); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + n_answer++; + } + + if (!found) { + first = hashmap_get(z->by_name, dns_resource_key_name(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + need_soa = true; + break; + } + } + } + + if (n_answer <= 0 && !need_soa) + goto return_empty; + + if (n_answer > 0) { + answer = dns_answer_new(n_answer); + if (!answer) + return -ENOMEM; + } + + if (need_soa) { + soa = dns_answer_new(1); + if (!soa) + return -ENOMEM; + } + + /* Second iteration, actually add the RRs to the answers */ + if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { + bool found = false, added = false; + int k; + + first = hashmap_get(z->by_name, dns_resource_key_name(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + k = dns_resource_key_match_rr(key, j->rr, NULL); + if (k < 0) + return k; + if (k > 0) { + r = dns_answer_add(answer, j->rr, ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + added = true; + } + } + + if (found && !added) { + r = dns_answer_add_soa(soa, dns_resource_key_name(key), LLMNR_DEFAULT_TTL, ifindex); + if (r < 0) + return r; + } + } else { + bool found = false; + + first = hashmap_get(z->by_key, key); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + found = true; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + r = dns_answer_add(answer, j->rr, ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + if (!found) { + bool add_soa = false; + + first = hashmap_get(z->by_name, dns_resource_key_name(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; + + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + add_soa = true; + } + + if (add_soa) { + r = dns_answer_add_soa(soa, dns_resource_key_name(key), LLMNR_DEFAULT_TTL, ifindex); + if (r < 0) + return r; + } + } + } + + /* If the caller sets ret_tentative to NULL, then use this as + * indication to not return tentative entries */ + + if (!ret_tentative && tentative) + goto return_empty; + + *ret_answer = answer; + answer = NULL; + + if (ret_soa) { + *ret_soa = soa; + soa = NULL; + } + + if (ret_tentative) + *ret_tentative = tentative; + + return 1; + +return_empty: + *ret_answer = NULL; + + if (ret_soa) + *ret_soa = NULL; + + if (ret_tentative) + *ret_tentative = false; + + return 0; +} + +void dns_zone_item_conflict(DnsZoneItem *i) { + assert(i); + + if (!IN_SET(i->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_VERIFYING, DNS_ZONE_ITEM_ESTABLISHED)) + return; + + log_info("Detected conflict on %s", strna(dns_resource_record_to_string(i->rr))); + + dns_zone_item_probe_stop(i); + + /* Withdraw the conflict item */ + i->state = DNS_ZONE_ITEM_WITHDRAWN; + + /* Maybe change the hostname */ + if (manager_is_own_hostname(i->scope->manager, dns_resource_key_name(i->rr->key)) > 0) + manager_next_hostname(i->scope->manager); +} + +void dns_zone_item_notify(DnsZoneItem *i) { + assert(i); + assert(i->probe_transaction); + + if (i->block_ready > 0) + return; + + if (IN_SET(i->probe_transaction->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) + return; + + if (i->probe_transaction->state == DNS_TRANSACTION_SUCCESS) { + bool we_lost = false; + + /* The probe got a successful reply. If we so far + * weren't established we just give up. If we already + * were established, and the peer has the + * lexicographically larger IP address we continue + * and defend it. */ + + if (!IN_SET(i->state, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) { + log_debug("Got a successful probe for not yet established RR, we lost."); + we_lost = true; + } else { + assert(i->probe_transaction->received); + we_lost = memcmp(&i->probe_transaction->received->sender, &i->probe_transaction->received->destination, FAMILY_ADDRESS_SIZE(i->probe_transaction->received->family)) < 0; + if (we_lost) + log_debug("Got a successful probe reply for an established RR, and we have a lexicographically larger IP address and thus lost."); + } + + if (we_lost) { + dns_zone_item_conflict(i); + return; + } + + log_debug("Got a successful probe reply, but peer has lexicographically lower IP address and thus lost."); + } + + log_debug("Record %s successfully probed.", strna(dns_resource_record_to_string(i->rr))); + + dns_zone_item_probe_stop(i); + i->state = DNS_ZONE_ITEM_ESTABLISHED; +} + +static int dns_zone_item_verify(DnsZoneItem *i) { + int r; + + assert(i); + + if (i->state != DNS_ZONE_ITEM_ESTABLISHED) + return 0; + + log_debug("Verifying RR %s", strna(dns_resource_record_to_string(i->rr))); + + i->state = DNS_ZONE_ITEM_VERIFYING; + r = dns_zone_item_probe_start(i); + if (r < 0) { + log_error_errno(r, "Failed to start probing for verifying RR: %m"); + i->state = DNS_ZONE_ITEM_ESTABLISHED; + return r; + } + + return 0; +} + +int dns_zone_check_conflicts(DnsZone *zone, DnsResourceRecord *rr) { + DnsZoneItem *i, *first; + int c = 0; + + assert(zone); + assert(rr); + + /* This checks whether a response RR we received from somebody + * else is one that we actually thought was uniquely ours. If + * so, we'll verify our RRs. */ + + /* No conflict if we don't have the name at all. */ + first = hashmap_get(zone->by_name, dns_resource_key_name(rr->key)); + if (!first) + return 0; + + /* No conflict if we have the exact same RR */ + if (dns_zone_get(zone, rr)) + return 0; + + /* OK, somebody else has RRs for the same name. Yuck! Let's + * start probing again */ + + LIST_FOREACH(by_name, i, first) { + if (dns_resource_record_equal(i->rr, rr)) + continue; + + dns_zone_item_verify(i); + c++; + } + + return c; +} + +int dns_zone_verify_conflicts(DnsZone *zone, DnsResourceKey *key) { + DnsZoneItem *i, *first; + int c = 0; + + assert(zone); + + /* Somebody else notified us about a possible conflict. Let's + * verify if that's true. */ + + first = hashmap_get(zone->by_name, dns_resource_key_name(key)); + if (!first) + return 0; + + LIST_FOREACH(by_name, i, first) { + dns_zone_item_verify(i); + c++; + } + + return c; +} + +void dns_zone_verify_all(DnsZone *zone) { + DnsZoneItem *i; + Iterator iterator; + + assert(zone); + + HASHMAP_FOREACH(i, zone->by_key, iterator) { + DnsZoneItem *j; + + LIST_FOREACH(by_key, j, i) + dns_zone_item_verify(j); + } +} + +void dns_zone_dump(DnsZone *zone, FILE *f) { + Iterator iterator; + DnsZoneItem *i; + + if (!zone) + return; + + if (!f) + f = stdout; + + HASHMAP_FOREACH(i, zone->by_key, iterator) { + DnsZoneItem *j; + + LIST_FOREACH(by_key, j, i) { + const char *t; + + t = dns_resource_record_to_string(j->rr); + if (!t) { + log_oom(); + continue; + } + + fputc('\t', f); + fputs(t, f); + fputc('\n', f); + } + } +} + +bool dns_zone_is_empty(DnsZone *zone) { + if (!zone) + return true; + + return hashmap_isempty(zone->by_key); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-zone.h b/src/grp-resolve/systemd-resolved/resolved-dns-zone.h new file mode 100644 index 0000000000..fe656be793 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-dns-zone.h @@ -0,0 +1,82 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/hashmap.h" + +typedef struct DnsZone { + Hashmap *by_key; + Hashmap *by_name; +} DnsZone; + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-question.h" +#include "basic-dns/resolved-dns-rr.h" + +typedef enum DnsZoneItemState DnsZoneItemState; +typedef struct DnsZoneItem DnsZoneItem; + +#include "resolved-dns-transaction.h" + +/* RFC 4795 Section 2.8. suggests a TTL of 30s by default */ +#define LLMNR_DEFAULT_TTL (30) + +enum DnsZoneItemState { + DNS_ZONE_ITEM_PROBING, + DNS_ZONE_ITEM_ESTABLISHED, + DNS_ZONE_ITEM_VERIFYING, + DNS_ZONE_ITEM_WITHDRAWN, +}; + +struct DnsZoneItem { + DnsScope *scope; + DnsResourceRecord *rr; + + DnsZoneItemState state; + + unsigned block_ready; + + bool probing_enabled; + + LIST_FIELDS(DnsZoneItem, by_key); + LIST_FIELDS(DnsZoneItem, by_name); + + DnsTransaction *probe_transaction; +}; + +void dns_zone_flush(DnsZone *z); + +int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe); +void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr); + +int dns_zone_lookup(DnsZone *z, DnsResourceKey *key, int ifindex, DnsAnswer **answer, DnsAnswer **soa, bool *tentative); + +void dns_zone_item_conflict(DnsZoneItem *i); +void dns_zone_item_notify(DnsZoneItem *i); + +int dns_zone_check_conflicts(DnsZone *zone, DnsResourceRecord *rr); +int dns_zone_verify_conflicts(DnsZone *zone, DnsResourceKey *key); + +void dns_zone_verify_all(DnsZone *zone); + +void dns_zone_item_probe_stop(DnsZoneItem *i); + +void dns_zone_dump(DnsZone *zone, FILE *f); +bool dns_zone_is_empty(DnsZone *zone); diff --git a/src/grp-resolve/systemd-resolved/resolved-etc-hosts.c b/src/grp-resolve/systemd-resolved/resolved-etc-hosts.c new file mode 100644 index 0000000000..942c06605e --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-etc-hosts.c @@ -0,0 +1,449 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/time-util.h" + +#include "resolved-dns-synthesize.h" +#include "resolved-etc-hosts.h" + +/* Recheck /etc/hosts at most once every 2s */ +#define ETC_HOSTS_RECHECK_USEC (2*USEC_PER_SEC) + +typedef struct EtcHostsItem { + int family; + union in_addr_union address; + + char **names; +} EtcHostsItem; + +typedef struct EtcHostsItemByName { + char *name; + + EtcHostsItem **items; + size_t n_items, n_allocated; +} EtcHostsItemByName; + +void manager_etc_hosts_flush(Manager *m) { + EtcHostsItem *item; + EtcHostsItemByName *bn; + + while ((item = set_steal_first(m->etc_hosts_by_address))) { + strv_free(item->names); + free(item); + } + + while ((bn = hashmap_steal_first(m->etc_hosts_by_name))) { + free(bn->name); + free(bn->items); + free(bn); + } + + m->etc_hosts_by_address = set_free(m->etc_hosts_by_address); + m->etc_hosts_by_name = hashmap_free(m->etc_hosts_by_name); + + m->etc_hosts_mtime = USEC_INFINITY; +} + +static void etc_hosts_item_hash_func(const void *p, struct siphash *state) { + const EtcHostsItem *item = p; + + siphash24_compress(&item->family, sizeof(item->family), state); + + if (item->family == AF_INET) + siphash24_compress(&item->address.in, sizeof(item->address.in), state); + else if (item->family == AF_INET6) + siphash24_compress(&item->address.in6, sizeof(item->address.in6), state); +} + +static int etc_hosts_item_compare_func(const void *a, const void *b) { + const EtcHostsItem *x = a, *y = b; + + if (x->family != y->family) + return x->family - y->family; + + if (x->family == AF_INET) + return memcmp(&x->address.in.s_addr, &y->address.in.s_addr, sizeof(struct in_addr)); + + if (x->family == AF_INET6) + return memcmp(&x->address.in6.s6_addr, &y->address.in6.s6_addr, sizeof(struct in6_addr)); + + return trivial_compare_func(a, b); +} + +static const struct hash_ops etc_hosts_item_ops = { + .hash = etc_hosts_item_hash_func, + .compare = etc_hosts_item_compare_func, +}; + +static int add_item(Manager *m, int family, const union in_addr_union *address, char **names) { + + EtcHostsItem key = { + .family = family, + .address = *address, + }; + EtcHostsItem *item; + char **n; + int r; + + assert(m); + assert(address); + + r = in_addr_is_null(family, address); + if (r < 0) + return r; + if (r > 0) + /* This is an 0.0.0.0 or :: item, which we assume means that we shall map the specified hostname to + * nothing. */ + item = NULL; + else { + /* If this is a normal address, then, simply add entry mapping it to the specified names */ + + item = set_get(m->etc_hosts_by_address, &key); + if (item) { + r = strv_extend_strv(&item->names, names, true); + if (r < 0) + return log_oom(); + } else { + + r = set_ensure_allocated(&m->etc_hosts_by_address, &etc_hosts_item_ops); + if (r < 0) + return log_oom(); + + item = new0(EtcHostsItem, 1); + if (!item) + return log_oom(); + + item->family = family; + item->address = *address; + item->names = names; + + r = set_put(m->etc_hosts_by_address, item); + if (r < 0) { + free(item); + return log_oom(); + } + } + } + + STRV_FOREACH(n, names) { + EtcHostsItemByName *bn; + + bn = hashmap_get(m->etc_hosts_by_name, *n); + if (!bn) { + r = hashmap_ensure_allocated(&m->etc_hosts_by_name, &dns_name_hash_ops); + if (r < 0) + return log_oom(); + + bn = new0(EtcHostsItemByName, 1); + if (!bn) + return log_oom(); + + bn->name = strdup(*n); + if (!bn->name) { + free(bn); + return log_oom(); + } + + r = hashmap_put(m->etc_hosts_by_name, bn->name, bn); + if (r < 0) { + free(bn->name); + free(bn); + return log_oom(); + } + } + + if (item) { + if (!GREEDY_REALLOC(bn->items, bn->n_allocated, bn->n_items+1)) + return log_oom(); + + bn->items[bn->n_items++] = item; + } + } + + return 0; +} + +static int parse_line(Manager *m, unsigned nr, const char *line) { + _cleanup_free_ char *address = NULL; + _cleanup_strv_free_ char **names = NULL; + union in_addr_union in; + bool suppressed = false; + int family, r; + + assert(m); + assert(line); + + r = extract_first_word(&line, &address, NULL, EXTRACT_RELAX); + if (r < 0) + return log_error_errno(r, "Couldn't extract address, in line /etc/hosts:%u.", nr); + if (r == 0) { + log_error("Premature end of line, in line /etc/hosts:%u.", nr); + return -EINVAL; + } + + r = in_addr_from_string_auto(address, &family, &in); + if (r < 0) + return log_error_errno(r, "Address '%s' is invalid, in line /etc/hosts:%u.", address, nr); + + for (;;) { + _cleanup_free_ char *name = NULL; + + r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX); + if (r < 0) + return log_error_errno(r, "Couldn't extract host name, in line /etc/hosts:%u.", nr); + if (r == 0) + break; + + r = dns_name_is_valid(name); + if (r <= 0) + return log_error_errno(r, "Hostname %s is not valid, ignoring, in line /etc/hosts:%u.", name, nr); + + if (is_localhost(name)) { + /* Suppress the "localhost" line that is often seen */ + suppressed = true; + continue; + } + + r = strv_push(&names, name); + if (r < 0) + return log_oom(); + + name = NULL; + } + + if (strv_isempty(names)) { + + if (suppressed) + return 0; + + log_error("Line is missing any host names, in line /etc/hosts:%u.", nr); + return -EINVAL; + } + + /* Takes possession of the names strv */ + r = add_item(m, family, &in, names); + if (r < 0) + return r; + + names = NULL; + return r; +} + +int manager_etc_hosts_read(Manager *m) { + _cleanup_fclose_ FILE *f = NULL; + char line[LINE_MAX]; + struct stat st; + usec_t ts; + unsigned nr = 0; + int r; + + assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0); + + /* See if we checked /etc/hosts recently already */ + if (m->etc_hosts_last != USEC_INFINITY && m->etc_hosts_last + ETC_HOSTS_RECHECK_USEC > ts) + return 0; + + m->etc_hosts_last = ts; + + if (m->etc_hosts_mtime != USEC_INFINITY) { + if (stat("/etc/hosts", &st) < 0) { + if (errno == ENOENT) { + r = 0; + goto clear; + } + + return log_error_errno(errno, "Failed to stat /etc/hosts: %m"); + } + + /* Did the mtime change? If not, there's no point in re-reading the file. */ + if (timespec_load(&st.st_mtim) == m->etc_hosts_mtime) + return 0; + } + + f = fopen("/etc/hosts", "re"); + if (!f) { + if (errno == ENOENT) { + r = 0; + goto clear; + } + + return log_error_errno(errno, "Failed to open /etc/hosts: %m"); + } + + /* Take the timestamp at the beginning of processing, so that any changes made later are read on the next + * invocation */ + r = fstat(fileno(f), &st); + if (r < 0) + return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m"); + + manager_etc_hosts_flush(m); + + FOREACH_LINE(line, f, return log_error_errno(errno, "Failed to read /etc/hosts: %m")) { + char *l; + + nr++; + + l = strstrip(line); + if (isempty(l)) + continue; + if (l[0] == '#') + continue; + + r = parse_line(m, nr, l); + if (r == -ENOMEM) /* On OOM we abandon the half-built-up structure. All other errors we ignore and proceed */ + goto clear; + } + + m->etc_hosts_mtime = timespec_load(&st.st_mtim); + m->etc_hosts_last = ts; + + return 1; + +clear: + manager_etc_hosts_flush(m); + return r; +} + +int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) { + bool found_a = false, found_aaaa = false; + EtcHostsItemByName *bn; + EtcHostsItem k = {}; + DnsResourceKey *t; + const char *name; + unsigned i; + int r; + + assert(m); + assert(q); + assert(answer); + + r = manager_etc_hosts_read(m); + if (r < 0) + return r; + + name = dns_question_first_name(q); + if (!name) + return 0; + + r = dns_name_address(name, &k.family, &k.address); + if (r > 0) { + EtcHostsItem *item; + DnsResourceKey *found_ptr = NULL; + + item = set_get(m->etc_hosts_by_address, &k); + if (!item) + return 0; + + /* We have an address in /etc/hosts that matches the queried name. Let's return successful. Actual data + * we'll only return if the request was for PTR. */ + + DNS_QUESTION_FOREACH(t, q) { + if (!IN_SET(t->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) + continue; + if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY)) + continue; + + r = dns_name_equal(dns_resource_key_name(t), name); + if (r < 0) + return r; + if (r > 0) { + found_ptr = t; + break; + } + } + + if (found_ptr) { + char **n; + + r = dns_answer_reserve(answer, strv_length(item->names)); + if (r < 0) + return r; + + STRV_FOREACH(n, item->names) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + rr = dns_resource_record_new(found_ptr); + if (!rr) + return -ENOMEM; + + rr->ptr.name = strdup(*n); + if (!rr->ptr.name) + return -ENOMEM; + + r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + } + + return 1; + } + + bn = hashmap_get(m->etc_hosts_by_name, name); + if (!bn) + return 0; + + r = dns_answer_reserve(answer, bn->n_items); + if (r < 0) + return r; + + DNS_QUESTION_FOREACH(t, q) { + if (!IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_AAAA, DNS_TYPE_ANY)) + continue; + if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY)) + continue; + + r = dns_name_equal(dns_resource_key_name(t), name); + if (r < 0) + return r; + if (r == 0) + continue; + + if (IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_ANY)) + found_a = true; + if (IN_SET(t->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) + found_aaaa = true; + + if (found_a && found_aaaa) + break; + } + + for (i = 0; i < bn->n_items; i++) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + + if ((found_a && bn->items[i]->family != AF_INET) && + (found_aaaa && bn->items[i]->family != AF_INET6)) + continue; + + r = dns_resource_record_new_address(&rr, bn->items[i]->family, &bn->items[i]->address, bn->name); + if (r < 0) + return r; + + r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 1; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-etc-hosts.h b/src/grp-resolve/systemd-resolved/resolved-etc-hosts.h new file mode 100644 index 0000000000..49e449b56d --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-etc-hosts.h @@ -0,0 +1,29 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "basic-dns/resolved-dns-answer.h" +#include "basic-dns/resolved-dns-question.h" + +#include "resolved-manager.h" + +void manager_etc_hosts_flush(Manager *m); +int manager_etc_hosts_read(Manager *m); +int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer); diff --git a/src/grp-resolve/systemd-resolved/resolved-gperf.gperf b/src/grp-resolve/systemd-resolved/resolved-gperf.gperf new file mode 100644 index 0000000000..79e54d8357 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-gperf.gperf @@ -0,0 +1,25 @@ +%{ +#include <stddef.h> + +#include "systemd-shared/conf-parser.h" + +#include "resolved-conf.h" +%} +struct ConfigPerfItem; +%null_strings +%language=ANSI-C +%define slot-name section_and_lvalue +%define hash-function-name resolved_gperf_hash +%define lookup-function-name resolved_gperf_lookup +%readonly-tables +%omit-struct-type +%struct-type +%includes +%% +Resolve.DNS, config_parse_dns_servers, DNS_SERVER_SYSTEM, 0 +Resolve.FallbackDNS, config_parse_dns_servers, DNS_SERVER_FALLBACK, 0 +Resolve.Domains, config_parse_search_domains, 0, 0 +Resolve.LLMNR, config_parse_resolve_support, 0, offsetof(Manager, llmnr_support) +Resolve.DNSSEC, config_parse_dnssec_mode, 0, offsetof(Manager, dnssec_mode) +Resolve.Cache, config_parse_bool, 0, offsetof(Manager, enable_cache) +Resolve.DNSStubListener, config_parse_dns_stub_listener_mode, 0, offsetof(Manager, dns_stub_listener_mode) diff --git a/src/grp-resolve/systemd-resolved/resolved-link-bus.c b/src/grp-resolve/systemd-resolved/resolved-link-bus.c new file mode 100644 index 0000000000..bea3c35829 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-link-bus.c @@ -0,0 +1,630 @@ +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "sd-bus/bus-common-errors.h" +#include "sd-bus/bus-util.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/strv.h" +#include "systemd-shared/resolve-util.h" + +#include "resolved-bus.h" +#include "resolved-link-bus.h" +#include "resolved-resolv-conf.h" + +static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_resolve_support, resolve_support, ResolveSupport); + +static int property_get_dnssec_mode( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + + assert(reply); + assert(l); + + return sd_bus_message_append(reply, "s", dnssec_mode_to_string(link_get_dnssec_mode(l))); +} + +static int property_get_dns( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + DnsServer *s; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "(iay)"); + if (r < 0) + return r; + + LIST_FOREACH(servers, s, l->dns_servers) { + r = bus_dns_server_append(reply, s, false); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_domains( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + DnsSearchDomain *d; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "(sb)"); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, l->search_domains) { + r = sd_bus_message_append(reply, "(sb)", d->name, d->route_only); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_scopes_mask( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + uint64_t mask; + + assert(reply); + assert(l); + + mask = (l->unicast_scope ? SD_RESOLVED_DNS : 0) | + (l->llmnr_ipv4_scope ? SD_RESOLVED_LLMNR_IPV4 : 0) | + (l->llmnr_ipv6_scope ? SD_RESOLVED_LLMNR_IPV6 : 0) | + (l->mdns_ipv4_scope ? SD_RESOLVED_MDNS_IPV4 : 0) | + (l->mdns_ipv6_scope ? SD_RESOLVED_MDNS_IPV6 : 0); + + return sd_bus_message_append(reply, "t", mask); +} + +static int property_get_ntas( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + const char *name; + Iterator i; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "s"); + if (r < 0) + return r; + + SET_FOREACH(name, l->dnssec_negative_trust_anchors, i) { + r = sd_bus_message_append(reply, "s", name); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_dnssec_supported( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + + assert(reply); + assert(l); + + return sd_bus_message_append(reply, "b", link_dnssec_supported(l)); +} + +static int verify_unmanaged_link(Link *l, sd_bus_error *error) { + assert(l); + + if (l->flags & IFF_LOOPBACK) + return sd_bus_error_setf(error, BUS_ERROR_LINK_BUSY, "Link %s is loopback device.", l->name); + if (l->is_managed) + return sd_bus_error_setf(error, BUS_ERROR_LINK_BUSY, "Link %s is managed.", l->name); + + return 0; +} + +int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_free_ struct in_addr_data *dns = NULL; + size_t allocated = 0, n = 0; + Link *l = userdata; + unsigned i; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(message, 'a', "(iay)"); + if (r < 0) + return r; + + for (;;) { + int family; + size_t sz; + const void *d; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_enter_container(message, 'r', "iay"); + if (r < 0) + return r; + if (r == 0) + break; + + r = sd_bus_message_read(message, "i", &family); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + r = sd_bus_message_read_array(message, 'y', &d, &sz); + if (r < 0) + return r; + if (sz != FAMILY_ADDRESS_SIZE(family)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size"); + + if (!dns_server_address_valid(family, d)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid DNS server address"); + + r = sd_bus_message_exit_container(message); + if (r < 0) + return r; + + if (!GREEDY_REALLOC(dns, allocated, n+1)) + return -ENOMEM; + + dns[n].family = family; + memcpy(&dns[n].address, d, sz); + n++; + } + + r = sd_bus_message_exit_container(message); + if (r < 0) + return r; + + dns_server_mark_all(l->dns_servers); + + for (i = 0; i < n; i++) { + DnsServer *s; + + s = dns_server_find(l->dns_servers, dns[i].family, &dns[i].address, 0); + if (s) + dns_server_move_back_and_unmark(s); + else { + r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, dns[i].family, &dns[i].address, 0); + if (r < 0) + goto clear; + } + + } + + dns_server_unlink_marked(l->dns_servers); + link_allocate_scopes(l); + + (void) link_save_user(l); + (void) manager_write_resolv_conf(l->manager); + + return sd_bus_reply_method_return(message, NULL); + +clear: + dns_server_unlink_all(l->dns_servers); + return r; +} + +int bus_link_method_set_domains(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_enter_container(message, 'a', "(sb)"); + if (r < 0) + return r; + + for (;;) { + const char *name; + int route_only; + + r = sd_bus_message_read(message, "(sb)", &name, &route_only); + if (r < 0) + return r; + if (r == 0) + break; + + r = dns_name_is_valid(name); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid search domain %s", name); + if (!route_only && dns_name_is_root(name)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Root domain is not suitable as search domain"); + } + + dns_search_domain_mark_all(l->search_domains); + + r = sd_bus_message_rewind(message, false); + if (r < 0) + return r; + + for (;;) { + DnsSearchDomain *d; + const char *name; + int route_only; + + r = sd_bus_message_read(message, "(sb)", &name, &route_only); + if (r < 0) + goto clear; + if (r == 0) + break; + + r = dns_search_domain_find(l->search_domains, name, &d); + if (r < 0) + goto clear; + + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(l->manager, &d, DNS_SEARCH_DOMAIN_LINK, l, name); + if (r < 0) + goto clear; + } + + d->route_only = route_only; + } + + r = sd_bus_message_exit_container(message); + if (r < 0) + goto clear; + + dns_search_domain_unlink_marked(l->search_domains); + + (void) link_save_user(l); + (void) manager_write_resolv_conf(l->manager); + + return sd_bus_reply_method_return(message, NULL); + +clear: + dns_search_domain_unlink_all(l->search_domains); + return r; +} + +int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + ResolveSupport mode; + const char *llmnr; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_read(message, "s", &llmnr); + if (r < 0) + return r; + + if (isempty(llmnr)) + mode = RESOLVE_SUPPORT_YES; + else { + mode = resolve_support_from_string(llmnr); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid LLMNR setting: %s", llmnr); + } + + l->llmnr_support = mode; + link_allocate_scopes(l); + link_add_rrs(l, false); + + (void) link_save_user(l); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + ResolveSupport mode; + const char *mdns; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_read(message, "s", &mdns); + if (r < 0) + return r; + + if (isempty(mdns)) + mode = RESOLVE_SUPPORT_NO; + else { + mode = resolve_support_from_string(mdns); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid MulticastDNS setting: %s", mdns); + } + + l->mdns_support = mode; + link_allocate_scopes(l); + link_add_rrs(l, false); + + (void) link_save_user(l); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + const char *dnssec; + DnssecMode mode; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_read(message, "s", &dnssec); + if (r < 0) + return r; + + if (isempty(dnssec)) + mode = _DNSSEC_MODE_INVALID; + else { + mode = dnssec_mode_from_string(dnssec); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid DNSSEC setting: %s", dnssec); + } + + link_set_dnssec_mode(l, mode); + + (void) link_save_user(l); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_set_free_free_ Set *ns = NULL; + _cleanup_free_ char **ntas = NULL; + Link *l = userdata; + int r; + char **i; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + r = sd_bus_message_read_strv(message, &ntas); + if (r < 0) + return r; + + STRV_FOREACH(i, ntas) { + r = dns_name_is_valid(*i); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid negative trust anchor domain: %s", *i); + } + + ns = set_new(&dns_name_hash_ops); + if (!ns) + return -ENOMEM; + + STRV_FOREACH(i, ntas) { + r = set_put_strdup(ns, *i); + if (r < 0) + return r; + } + + set_free_free(l->dnssec_negative_trust_anchors); + l->dnssec_negative_trust_anchors = ns; + ns = NULL; + + (void) link_save_user(l); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + int r; + + assert(message); + assert(l); + + r = verify_unmanaged_link(l, error); + if (r < 0) + return r; + + link_flush_settings(l); + link_allocate_scopes(l); + link_add_rrs(l, false); + + (void) link_save_user(l); + (void) manager_write_resolv_conf(l->manager); + + return sd_bus_reply_method_return(message, NULL); +} + +const sd_bus_vtable link_vtable[] = { + SD_BUS_VTABLE_START(0), + + SD_BUS_PROPERTY("ScopesMask", "t", property_get_scopes_mask, 0, 0), + SD_BUS_PROPERTY("DNS", "a(iay)", property_get_dns, 0, 0), + SD_BUS_PROPERTY("Domains", "a(sb)", property_get_domains, 0, 0), + SD_BUS_PROPERTY("LLMNR", "s", property_get_resolve_support, offsetof(Link, llmnr_support), 0), + SD_BUS_PROPERTY("MulticastDNS", "s", property_get_resolve_support, offsetof(Link, mdns_support), 0), + SD_BUS_PROPERTY("DNSSEC", "s", property_get_dnssec_mode, 0, 0), + SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", property_get_ntas, 0, 0), + SD_BUS_PROPERTY("DNSSECSupported", "b", property_get_dnssec_supported, 0, 0), + + SD_BUS_METHOD("SetDNS", "a(iay)", NULL, bus_link_method_set_dns_servers, 0), + SD_BUS_METHOD("SetDomains", "a(sb)", NULL, bus_link_method_set_domains, 0), + SD_BUS_METHOD("SetLLMNR", "s", NULL, bus_link_method_set_llmnr, 0), + SD_BUS_METHOD("SetMulticastDNS", "s", NULL, bus_link_method_set_mdns, 0), + SD_BUS_METHOD("SetDNSSEC", "s", NULL, bus_link_method_set_dnssec, 0), + SD_BUS_METHOD("SetDNSSECNegativeTrustAnchors", "as", NULL, bus_link_method_set_dnssec_negative_trust_anchors, 0), + SD_BUS_METHOD("Revert", NULL, NULL, bus_link_method_revert, 0), + + SD_BUS_VTABLE_END +}; + +int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + _cleanup_free_ char *e = NULL; + Manager *m = userdata; + int ifindex; + Link *link; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = sd_bus_path_decode(path, "/org/freedesktop/resolve1/link", &e); + if (r <= 0) + return 0; + + r = parse_ifindex(e, &ifindex); + if (r < 0) + return 0; + + link = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!link) + return 0; + + *found = link; + return 1; +} + +char *link_bus_path(Link *link) { + _cleanup_free_ char *ifindex = NULL; + char *p; + int r; + + assert(link); + + if (asprintf(&ifindex, "%i", link->ifindex) < 0) + return NULL; + + r = sd_bus_path_encode("/org/freedesktop/resolve1/link", ifindex, &p); + if (r < 0) + return NULL; + + return p; +} + +int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) { + _cleanup_strv_free_ char **l = NULL; + Manager *m = userdata; + Link *link; + Iterator i; + unsigned c = 0; + + assert(bus); + assert(path); + assert(m); + assert(nodes); + + l = new0(char*, hashmap_size(m->links) + 1); + if (!l) + return -ENOMEM; + + HASHMAP_FOREACH(link, m->links, i) { + char *p; + + p = link_bus_path(link); + if (!p) + return -ENOMEM; + + l[c++] = p; + } + + l[c] = NULL; + *nodes = l; + l = NULL; + + return 1; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-link-bus.h b/src/grp-resolve/systemd-resolved/resolved-link-bus.h new file mode 100644 index 0000000000..b1ac57961d --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-link-bus.h @@ -0,0 +1,38 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-bus.h> + +#include "resolved-link.h" + +extern const sd_bus_vtable link_vtable[]; + +int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error); +char *link_bus_path(Link *link); +int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error); + +int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_domains(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error *error); diff --git a/src/grp-resolve/systemd-resolved/resolved-link.c b/src/grp-resolve/systemd-resolved/resolved-link.c new file mode 100644 index 0000000000..99be607b09 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-link.c @@ -0,0 +1,1113 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <net/if.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/missing.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-staging/sd-network.h" + +#include "resolved-link.h" + +int link_new(Manager *m, Link **ret, int ifindex) { + _cleanup_(link_freep) Link *l = NULL; + int r; + + assert(m); + assert(ifindex > 0); + + r = hashmap_ensure_allocated(&m->links, NULL); + if (r < 0) + return r; + + l = new0(Link, 1); + if (!l) + return -ENOMEM; + + l->ifindex = ifindex; + l->llmnr_support = RESOLVE_SUPPORT_YES; + l->mdns_support = RESOLVE_SUPPORT_NO; + l->dnssec_mode = _DNSSEC_MODE_INVALID; + l->operstate = IF_OPER_UNKNOWN; + + if (asprintf(&l->state_file, "/run/systemd/resolve/netif/%i", ifindex) < 0) + return -ENOMEM; + + r = hashmap_put(m->links, INT_TO_PTR(ifindex), l); + if (r < 0) + return r; + + l->manager = m; + + if (ret) + *ret = l; + l = NULL; + + return 0; +} + +void link_flush_settings(Link *l) { + assert(l); + + l->llmnr_support = RESOLVE_SUPPORT_YES; + l->mdns_support = RESOLVE_SUPPORT_NO; + l->dnssec_mode = _DNSSEC_MODE_INVALID; + + dns_server_unlink_all(l->dns_servers); + dns_search_domain_unlink_all(l->search_domains); + + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); +} + +Link *link_free(Link *l) { + if (!l) + return NULL; + + link_flush_settings(l); + + while (l->addresses) + (void) link_address_free(l->addresses); + + if (l->manager) + hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex)); + + dns_scope_free(l->unicast_scope); + dns_scope_free(l->llmnr_ipv4_scope); + dns_scope_free(l->llmnr_ipv6_scope); + dns_scope_free(l->mdns_ipv4_scope); + dns_scope_free(l->mdns_ipv6_scope); + + free(l->state_file); + + return mfree(l); +} + +void link_allocate_scopes(Link *l) { + int r; + + assert(l); + + if (link_relevant(l, AF_UNSPEC, false) && + l->dns_servers) { + if (!l->unicast_scope) { + r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC); + if (r < 0) + log_warning_errno(r, "Failed to allocate DNS scope: %m"); + } + } else + l->unicast_scope = dns_scope_free(l->unicast_scope); + + if (link_relevant(l, AF_INET, true) && + l->llmnr_support != RESOLVE_SUPPORT_NO && + l->manager->llmnr_support != RESOLVE_SUPPORT_NO) { + if (!l->llmnr_ipv4_scope) { + r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET); + if (r < 0) + log_warning_errno(r, "Failed to allocate LLMNR IPv4 scope: %m"); + } + } else + l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope); + + if (link_relevant(l, AF_INET6, true) && + l->llmnr_support != RESOLVE_SUPPORT_NO && + l->manager->llmnr_support != RESOLVE_SUPPORT_NO && + socket_ipv6_is_supported()) { + if (!l->llmnr_ipv6_scope) { + r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6); + if (r < 0) + log_warning_errno(r, "Failed to allocate LLMNR IPv6 scope: %m"); + } + } else + l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope); + + if (link_relevant(l, AF_INET, true) && + l->mdns_support != RESOLVE_SUPPORT_NO && + l->manager->mdns_support != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv4_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv4_scope, l, DNS_PROTOCOL_MDNS, AF_INET); + if (r < 0) + log_warning_errno(r, "Failed to allocate mDNS IPv4 scope: %m"); + } + } else + l->mdns_ipv4_scope = dns_scope_free(l->mdns_ipv4_scope); + + if (link_relevant(l, AF_INET6, true) && + l->mdns_support != RESOLVE_SUPPORT_NO && + l->manager->mdns_support != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv6_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv6_scope, l, DNS_PROTOCOL_MDNS, AF_INET6); + if (r < 0) + log_warning_errno(r, "Failed to allocate mDNS IPv6 scope: %m"); + } + } else + l->mdns_ipv6_scope = dns_scope_free(l->mdns_ipv6_scope); +} + +void link_add_rrs(Link *l, bool force_remove) { + LinkAddress *a; + + LIST_FOREACH(addresses, a, l->addresses) + link_address_add_rrs(a, force_remove); +} + +int link_process_rtnl(Link *l, sd_netlink_message *m) { + const char *n = NULL; + int r; + + assert(l); + assert(m); + + r = sd_rtnl_message_link_get_flags(m, &l->flags); + if (r < 0) + return r; + + (void) sd_netlink_message_read_u32(m, IFLA_MTU, &l->mtu); + (void) sd_netlink_message_read_u8(m, IFLA_OPERSTATE, &l->operstate); + + if (sd_netlink_message_read_string(m, IFLA_IFNAME, &n) >= 0) { + strncpy(l->name, n, sizeof(l->name)-1); + char_array_0(l->name); + } + + link_allocate_scopes(l); + link_add_rrs(l, false); + + return 0; +} + +static int link_update_dns_server_one(Link *l, const char *name) { + union in_addr_union a; + DnsServer *s; + int family, r; + + assert(l); + assert(name); + + r = in_addr_from_string_auto(name, &family, &a); + if (r < 0) + return r; + + s = dns_server_find(l->dns_servers, family, &a, 0); + if (s) { + dns_server_move_back_and_unmark(s); + return 0; + } + + return dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a, 0); +} + +static int link_update_dns_servers(Link *l) { + _cleanup_strv_free_ char **nameservers = NULL; + char **nameserver; + int r; + + assert(l); + + r = sd_network_link_get_dns(l->ifindex, &nameservers); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + dns_server_mark_all(l->dns_servers); + + STRV_FOREACH(nameserver, nameservers) { + r = link_update_dns_server_one(l, *nameserver); + if (r < 0) + goto clear; + } + + dns_server_unlink_marked(l->dns_servers); + return 0; + +clear: + dns_server_unlink_all(l->dns_servers); + return r; +} + +static int link_update_llmnr_support(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + r = sd_network_link_get_llmnr(l->ifindex, &b); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + l->llmnr_support = resolve_support_from_string(b); + if (l->llmnr_support < 0) { + r = -EINVAL; + goto clear; + } + + return 0; + +clear: + l->llmnr_support = RESOLVE_SUPPORT_YES; + return r; +} + +static int link_update_mdns_support(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + r = sd_network_link_get_mdns(l->ifindex, &b); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + l->mdns_support = resolve_support_from_string(b); + if (l->mdns_support < 0) { + r = -EINVAL; + goto clear; + } + + return 0; + +clear: + l->mdns_support = RESOLVE_SUPPORT_NO; + return r; +} + +void link_set_dnssec_mode(Link *l, DnssecMode mode) { + + assert(l); + + if (l->dnssec_mode == mode) + return; + + if ((l->dnssec_mode == _DNSSEC_MODE_INVALID) || + (l->dnssec_mode == DNSSEC_NO && mode != DNSSEC_NO) || + (l->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE && mode == DNSSEC_YES)) { + + /* When switching from non-DNSSEC mode to DNSSEC mode, flush the cache. Also when switching from the + * allow-downgrade mode to full DNSSEC mode, flush it too. */ + if (l->unicast_scope) + dns_cache_flush(&l->unicast_scope->cache); + } + + l->dnssec_mode = mode; +} + +static int link_update_dnssec_mode(Link *l) { + _cleanup_free_ char *m = NULL; + DnssecMode mode; + int r; + + assert(l); + + r = sd_network_link_get_dnssec(l->ifindex, &m); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + mode = dnssec_mode_from_string(m); + if (mode < 0) { + r = -EINVAL; + goto clear; + } + + link_set_dnssec_mode(l, mode); + + return 0; + +clear: + l->dnssec_mode = _DNSSEC_MODE_INVALID; + return r; +} + +static int link_update_dnssec_negative_trust_anchors(Link *l) { + _cleanup_strv_free_ char **ntas = NULL; + _cleanup_set_free_free_ Set *ns = NULL; + int r; + + assert(l); + + r = sd_network_link_get_dnssec_negative_trust_anchors(l->ifindex, &ntas); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + ns = set_new(&dns_name_hash_ops); + if (!ns) + return -ENOMEM; + + r = set_put_strdupv(ns, ntas); + if (r < 0) + return r; + + set_free_free(l->dnssec_negative_trust_anchors); + l->dnssec_negative_trust_anchors = ns; + ns = NULL; + + return 0; + +clear: + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); + return r; +} + +static int link_update_search_domain_one(Link *l, const char *name, bool route_only) { + DnsSearchDomain *d; + int r; + + assert(l); + assert(name); + + r = dns_search_domain_find(l->search_domains, name, &d); + if (r < 0) + return r; + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(l->manager, &d, DNS_SEARCH_DOMAIN_LINK, l, name); + if (r < 0) + return r; + } + + d->route_only = route_only; + return 0; +} + +static int link_update_search_domains(Link *l) { + _cleanup_strv_free_ char **sdomains = NULL, **rdomains = NULL; + char **i; + int r, q; + + assert(l); + + r = sd_network_link_get_search_domains(l->ifindex, &sdomains); + if (r < 0 && r != -ENODATA) + goto clear; + + q = sd_network_link_get_route_domains(l->ifindex, &rdomains); + if (q < 0 && q != -ENODATA) { + r = q; + goto clear; + } + + if (r == -ENODATA && q == -ENODATA) { + /* networkd knows nothing about this interface, and that's fine. */ + r = 0; + goto clear; + } + + dns_search_domain_mark_all(l->search_domains); + + STRV_FOREACH(i, sdomains) { + r = link_update_search_domain_one(l, *i, false); + if (r < 0) + goto clear; + } + + STRV_FOREACH(i, rdomains) { + r = link_update_search_domain_one(l, *i, true); + if (r < 0) + goto clear; + } + + dns_search_domain_unlink_marked(l->search_domains); + return 0; + +clear: + dns_search_domain_unlink_all(l->search_domains); + return r; +} + +static int link_is_managed(Link *l) { + _cleanup_free_ char *state = NULL; + int r; + + assert(l); + + r = sd_network_link_get_setup_state(l->ifindex, &state); + if (r == -ENODATA) + return 0; + if (r < 0) + return r; + + return !STR_IN_SET(state, "pending", "unmanaged"); +} + +static void link_read_settings(Link *l) { + int r; + + assert(l); + + /* Read settings from networkd, except when networkd is not managing this interface. */ + + r = link_is_managed(l); + if (r < 0) { + log_warning_errno(r, "Failed to determine whether interface %s is managed: %m", l->name); + return; + } + if (r == 0) { + + /* If this link used to be managed, but is now unmanaged, flush all our settings — but only once. */ + if (l->is_managed) + link_flush_settings(l); + + l->is_managed = false; + return; + } + + l->is_managed = true; + + r = link_update_dns_servers(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNS servers for interface %s, ignoring: %m", l->name); + + r = link_update_llmnr_support(l); + if (r < 0) + log_warning_errno(r, "Failed to read LLMNR support for interface %s, ignoring: %m", l->name); + + r = link_update_mdns_support(l); + if (r < 0) + log_warning_errno(r, "Failed to read mDNS support for interface %s, ignoring: %m", l->name); + + r = link_update_dnssec_mode(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNSSEC mode for interface %s, ignoring: %m", l->name); + + r = link_update_dnssec_negative_trust_anchors(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNSSEC negative trust anchors for interface %s, ignoring: %m", l->name); + + r = link_update_search_domains(l); + if (r < 0) + log_warning_errno(r, "Failed to read search domains for interface %s, ignoring: %m", l->name); +} + +int link_update(Link *l) { + assert(l); + + link_read_settings(l); + link_load_user(l); + link_allocate_scopes(l); + link_add_rrs(l, false); + + return 0; +} + +bool link_relevant(Link *l, int family, bool local_multicast) { + _cleanup_free_ char *state = NULL; + LinkAddress *a; + + assert(l); + + /* A link is relevant for local multicast traffic if it isn't a loopback or pointopoint device, has a link + * beat, can do multicast and has at least one link-local (or better) IP address. + * + * A link is relevant for non-multicast traffic if it isn't a loopback device, has a link beat, and has at + * least one routable address.*/ + + if (l->flags & (IFF_LOOPBACK|IFF_DORMANT)) + return false; + + if ((l->flags & (IFF_UP|IFF_LOWER_UP)) != (IFF_UP|IFF_LOWER_UP)) + return false; + + if (local_multicast) { + if (l->flags & IFF_POINTOPOINT) + return false; + + if ((l->flags & IFF_MULTICAST) != IFF_MULTICAST) + return false; + } + + /* Check kernel operstate + * https://www.kernel.org/doc/Documentation/networking/operstates.txt */ + if (!IN_SET(l->operstate, IF_OPER_UNKNOWN, IF_OPER_UP)) + return false; + + (void) sd_network_link_get_operational_state(l->ifindex, &state); + if (state && !STR_IN_SET(state, "unknown", "degraded", "routable")) + return false; + + LIST_FOREACH(addresses, a, l->addresses) + if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a, local_multicast)) + return true; + + return false; +} + +LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) { + LinkAddress *a; + + assert(l); + + LIST_FOREACH(addresses, a, l->addresses) + if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr)) + return a; + + return NULL; +} + +DnsServer* link_set_dns_server(Link *l, DnsServer *s) { + assert(l); + + if (l->current_dns_server == s) + return s; + + if (s) + log_info("Switching to DNS server %s for interface %s.", dns_server_string(s), l->name); + + dns_server_unref(l->current_dns_server); + l->current_dns_server = dns_server_ref(s); + + if (l->unicast_scope) + dns_cache_flush(&l->unicast_scope->cache); + + return s; +} + +DnsServer *link_get_dns_server(Link *l) { + assert(l); + + if (!l->current_dns_server) + link_set_dns_server(l, l->dns_servers); + + return l->current_dns_server; +} + +void link_next_dns_server(Link *l) { + assert(l); + + if (!l->current_dns_server) + return; + + /* Change to the next one, but make sure to follow the linked + * list only if this server is actually still linked. */ + if (l->current_dns_server->linked && l->current_dns_server->servers_next) { + link_set_dns_server(l, l->current_dns_server->servers_next); + return; + } + + link_set_dns_server(l, l->dns_servers); +} + +DnssecMode link_get_dnssec_mode(Link *l) { + assert(l); + + if (l->dnssec_mode != _DNSSEC_MODE_INVALID) + return l->dnssec_mode; + + return manager_get_dnssec_mode(l->manager); +} + +bool link_dnssec_supported(Link *l) { + DnsServer *server; + + assert(l); + + if (link_get_dnssec_mode(l) == DNSSEC_NO) + return false; + + server = link_get_dns_server(l); + if (server) + return dns_server_dnssec_supported(server); + + return true; +} + +int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) { + LinkAddress *a; + + assert(l); + assert(in_addr); + + a = new0(LinkAddress, 1); + if (!a) + return -ENOMEM; + + a->family = family; + a->in_addr = *in_addr; + + a->link = l; + LIST_PREPEND(addresses, l->addresses, a); + + if (ret) + *ret = a; + + return 0; +} + +LinkAddress *link_address_free(LinkAddress *a) { + if (!a) + return NULL; + + if (a->link) { + LIST_REMOVE(addresses, a->link->addresses, a); + + if (a->llmnr_address_rr) { + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->family == AF_INET && a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + } + } + + dns_resource_record_unref(a->llmnr_address_rr); + dns_resource_record_unref(a->llmnr_ptr_rr); + + return mfree(a); +} + +void link_address_add_rrs(LinkAddress *a, bool force_remove) { + int r; + + assert(a); + + if (a->family == AF_INET) { + + if (!force_remove && + link_address_relevant(a, true) && + a->link->llmnr_ipv4_scope && + a->link->llmnr_support == RESOLVE_SUPPORT_YES && + a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { + + if (!a->link->manager->llmnr_host_ipv4_key) { + a->link->manager->llmnr_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->llmnr_hostname); + if (!a->link->manager->llmnr_host_ipv4_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->llmnr_address_rr) { + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv4_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->a.in_addr = a->in_addr.in; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; + } + + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname); + if (r < 0) + goto fail; + + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true); + if (r < 0) + log_warning_errno(r, "Failed to add A record to LLMNR zone: %m"); + + r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false); + if (r < 0) + log_warning_errno(r, "Failed to add IPv6 PTR record to LLMNR zone: %m"); + } else { + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv4_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } + } + } + + if (a->family == AF_INET6) { + + if (!force_remove && + link_address_relevant(a, true) && + a->link->llmnr_ipv6_scope && + a->link->llmnr_support == RESOLVE_SUPPORT_YES && + a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { + + if (!a->link->manager->llmnr_host_ipv6_key) { + a->link->manager->llmnr_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->llmnr_hostname); + if (!a->link->manager->llmnr_host_ipv6_key) { + r = -ENOMEM; + goto fail; + } + } + + if (!a->llmnr_address_rr) { + a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv6_key); + if (!a->llmnr_address_rr) { + r = -ENOMEM; + goto fail; + } + + a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6; + a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL; + } + + if (!a->llmnr_ptr_rr) { + r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname); + if (r < 0) + goto fail; + + a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL; + } + + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true); + if (r < 0) + log_warning_errno(r, "Failed to add AAAA record to LLMNR zone: %m"); + + r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false); + if (r < 0) + log_warning_errno(r, "Failed to add IPv6 PTR record to LLMNR zone: %m"); + } else { + if (a->llmnr_address_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr); + a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr); + } + + if (a->llmnr_ptr_rr) { + if (a->link->llmnr_ipv6_scope) + dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr); + a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr); + } + } + } + + return; + +fail: + log_debug_errno(r, "Failed to update address RRs: %m"); +} + +int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m) { + int r; + assert(a); + assert(m); + + r = sd_rtnl_message_addr_get_flags(m, &a->flags); + if (r < 0) + return r; + + sd_rtnl_message_addr_get_scope(m, &a->scope); + + link_allocate_scopes(a->link); + link_add_rrs(a->link, false); + + return 0; +} + +bool link_address_relevant(LinkAddress *a, bool local_multicast) { + assert(a); + + if (a->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE)) + return false; + + if (a->scope >= (local_multicast ? RT_SCOPE_HOST : RT_SCOPE_LINK)) + return false; + + return true; +} + +static bool link_needs_save(Link *l) { + assert(l); + + /* Returns true if any of the settings where set different from the default */ + + if (l->is_managed) + return false; + + if (l->llmnr_support != RESOLVE_SUPPORT_YES || + l->mdns_support != RESOLVE_SUPPORT_NO || + l->dnssec_mode != _DNSSEC_MODE_INVALID) + return true; + + if (l->dns_servers || + l->search_domains) + return true; + + if (!set_isempty(l->dnssec_negative_trust_anchors)) + return true; + + return false; +} + +int link_save_user(Link *l) { + _cleanup_free_ char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + const char *v; + int r; + + assert(l); + assert(l->state_file); + + if (!link_needs_save(l)) { + (void) unlink(l->state_file); + return 0; + } + + r = mkdir_parents(l->state_file, 0700); + if (r < 0) + goto fail; + + r = fopen_temporary(l->state_file, &f, &temp_path); + if (r < 0) + goto fail; + + fputs("# This is private data. Do not parse.\n", f); + + v = resolve_support_to_string(l->llmnr_support); + if (v) + fprintf(f, "LLMNR=%s\n", v); + + v = resolve_support_to_string(l->mdns_support); + if (v) + fprintf(f, "MDNS=%s\n", v); + + v = dnssec_mode_to_string(l->dnssec_mode); + if (v) + fprintf(f, "DNSSEC=%s\n", v); + + if (l->dns_servers) { + DnsServer *server; + + fputs("SERVERS=", f); + LIST_FOREACH(servers, server, l->dns_servers) { + + if (server != l->dns_servers) + fputc(' ', f); + + v = dns_server_string(server); + if (!v) { + r = -ENOMEM; + goto fail; + } + + fputs(v, f); + } + fputc('\n', f); + } + + if (l->search_domains) { + DnsSearchDomain *domain; + + fputs("DOMAINS=", f); + LIST_FOREACH(domains, domain, l->search_domains) { + + if (domain != l->search_domains) + fputc(' ', f); + + if (domain->route_only) + fputc('~', f); + + fputs(DNS_SEARCH_DOMAIN_NAME(domain), f); + } + fputc('\n', f); + } + + if (!set_isempty(l->dnssec_negative_trust_anchors)) { + bool space = false; + Iterator i; + char *nta; + + fputs("NTAS=", f); + SET_FOREACH(nta, l->dnssec_negative_trust_anchors, i) { + + if (space) + fputc(' ', f); + + fputs(nta, f); + space = true; + } + fputc('\n', f); + } + + r = fflush_and_check(f); + if (r < 0) + goto fail; + + if (rename(temp_path, l->state_file) < 0) { + r = -errno; + goto fail; + } + + return 0; + +fail: + (void) unlink(l->state_file); + + if (temp_path) + (void) unlink(temp_path); + + return log_error_errno(r, "Failed to save link data %s: %m", l->state_file); +} + +int link_load_user(Link *l) { + _cleanup_free_ char + *llmnr = NULL, + *mdns = NULL, + *dnssec = NULL, + *servers = NULL, + *domains = NULL, + *ntas = NULL; + + ResolveSupport s; + int r; + + assert(l); + assert(l->state_file); + + /* Try to load only a single time */ + if (l->loaded) + return 0; + l->loaded = true; + + if (l->is_managed) + return 0; /* if the device is managed, then networkd is our configuration source, not the bus API */ + + r = parse_env_file(l->state_file, NEWLINE, + "LLMNR", &llmnr, + "MDNS", &mdns, + "DNSSEC", &dnssec, + "SERVERS", &servers, + "DOMAINS", &domains, + "NTAS", &ntas, + NULL); + if (r == -ENOENT) + return 0; + if (r < 0) + goto fail; + + link_flush_settings(l); + + /* If we can't recognize the LLMNR or MDNS setting we don't override the default */ + s = resolve_support_from_string(llmnr); + if (s >= 0) + l->llmnr_support = s; + + s = resolve_support_from_string(mdns); + if (s >= 0) + l->mdns_support = s; + + /* If we can't recognize the DNSSEC setting, then set it to invalid, so that the daemon default is used. */ + l->dnssec_mode = dnssec_mode_from_string(dnssec); + + if (servers) { + const char *p = servers; + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + goto fail; + if (r == 0) + break; + + r = link_update_dns_server_one(l, word); + if (r < 0) { + log_debug_errno(r, "Failed to load DNS server '%s', ignoring: %m", word); + continue; + } + } + } + + if (domains) { + const char *p = domains; + + for (;;) { + _cleanup_free_ char *word = NULL; + const char *n; + bool is_route; + + r = extract_first_word(&p, &word, NULL, 0); + if (r < 0) + goto fail; + if (r == 0) + break; + + is_route = word[0] == '~'; + n = is_route ? word + 1 : word; + + r = link_update_search_domain_one(l, n, is_route); + if (r < 0) { + log_debug_errno(r, "Failed to load search domain '%s', ignoring: %m", word); + continue; + } + } + } + + if (ntas) { + _cleanup_set_free_free_ Set *ns = NULL; + + ns = set_new(&dns_name_hash_ops); + if (!ns) { + r = -ENOMEM; + goto fail; + } + + r = set_put_strsplit(ns, ntas, NULL, 0); + if (r < 0) + goto fail; + + l->dnssec_negative_trust_anchors = ns; + ns = NULL; + } + + return 0; + +fail: + return log_error_errno(r, "Failed to load link data %s: %m", l->state_file); +} + +void link_remove_user(Link *l) { + assert(l); + assert(l->state_file); + + (void) unlink(l->state_file); +} diff --git a/src/grp-resolve/systemd-resolved/resolved-link.h b/src/grp-resolve/systemd-resolved/resolved-link.h new file mode 100644 index 0000000000..271309914f --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-link.h @@ -0,0 +1,119 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <net/if.h> + +#include "basic-dns/resolved-dns-rr.h" +#include "systemd-basic/in-addr-util.h" +#include "systemd-basic/ratelimit.h" +#include "systemd-shared/resolve-util.h" + +typedef struct Link Link; +typedef struct LinkAddress LinkAddress; + +#include "resolved-dns-scope.h" +#include "resolved-dns-search-domain.h" +#include "resolved-dns-server.h" +#include "resolved-manager.h" + +#define LINK_SEARCH_DOMAINS_MAX 32 +#define LINK_DNS_SERVERS_MAX 32 + +struct LinkAddress { + Link *link; + + int family; + union in_addr_union in_addr; + + unsigned char flags, scope; + + DnsResourceRecord *llmnr_address_rr; + DnsResourceRecord *llmnr_ptr_rr; + + LIST_FIELDS(LinkAddress, addresses); +}; + +struct Link { + Manager *manager; + + int ifindex; + unsigned flags; + + LIST_HEAD(LinkAddress, addresses); + + LIST_HEAD(DnsServer, dns_servers); + DnsServer *current_dns_server; + unsigned n_dns_servers; + + LIST_HEAD(DnsSearchDomain, search_domains); + unsigned n_search_domains; + + ResolveSupport llmnr_support; + ResolveSupport mdns_support; + DnssecMode dnssec_mode; + Set *dnssec_negative_trust_anchors; + + DnsScope *unicast_scope; + DnsScope *llmnr_ipv4_scope; + DnsScope *llmnr_ipv6_scope; + DnsScope *mdns_ipv4_scope; + DnsScope *mdns_ipv6_scope; + + bool is_managed; + + char name[IF_NAMESIZE]; + uint32_t mtu; + uint8_t operstate; + + bool loaded; + char *state_file; +}; + +int link_new(Manager *m, Link **ret, int ifindex); +Link *link_free(Link *l); +int link_process_rtnl(Link *l, sd_netlink_message *m); +int link_update(Link *l); +bool link_relevant(Link *l, int family, bool local_multicast); +LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); +void link_add_rrs(Link *l, bool force_remove); + +void link_flush_settings(Link *l); +void link_set_dnssec_mode(Link *l, DnssecMode mode); +void link_allocate_scopes(Link *l); + +DnsServer* link_set_dns_server(Link *l, DnsServer *s); +DnsServer* link_get_dns_server(Link *l); +void link_next_dns_server(Link *l); + +DnssecMode link_get_dnssec_mode(Link *l); +bool link_dnssec_supported(Link *l); + +int link_save_user(Link *l); +int link_load_user(Link *l); +void link_remove_user(Link *l); + +int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr); +LinkAddress *link_address_free(LinkAddress *a); +int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m); +bool link_address_relevant(LinkAddress *l, bool local_multicast); +void link_address_add_rrs(LinkAddress *a, bool force_remove); + +DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_free); diff --git a/src/grp-resolve/systemd-resolved/resolved-llmnr.c b/src/grp-resolve/systemd-resolved/resolved-llmnr.c new file mode 100644 index 0000000000..2a22f20790 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-llmnr.c @@ -0,0 +1,472 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <netinet/in.h> +#include <resolv.h> + +#include "systemd-basic/fd-util.h" + +#include "resolved-llmnr.h" +#include "resolved-manager.h" + +void manager_llmnr_stop(Manager *m) { + assert(m); + + m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source); + m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); + + m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source); + m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); + + m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + + m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); +} + +int manager_llmnr_start(Manager *m) { + int r; + + assert(m); + + if (m->llmnr_support == RESOLVE_SUPPORT_NO) + return 0; + + r = manager_llmnr_ipv4_udp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + r = manager_llmnr_ipv4_tcp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + if (socket_ipv6_is_supported()) { + r = manager_llmnr_ipv6_udp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + r = manager_llmnr_ipv6_tcp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + } + + return 0; + +eaddrinuse: + log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); + m->llmnr_support = RESOLVE_SUPPORT_NO; + manager_llmnr_stop(m); + + return 0; +} + +static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t = NULL; + Manager *m = userdata; + DnsScope *scope; + int r; + + assert(s); + assert(fd >= 0); + assert(m); + + r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p); + if (r <= 0) + return r; + + scope = manager_find_scope(m, p); + if (!scope) + log_warning("Got LLMNR UDP packet on unknown scope. Ignoring."); + else if (dns_packet_validate_reply(p) > 0) { + log_debug("Got LLMNR UDP reply packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_check_conflicts(scope, p); + + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + if (t) + dns_transaction_process_reply(t, p); + + } else if (dns_packet_validate_query(p) > 0) { + log_debug("Got LLMNR UDP query packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_process_query(scope, NULL, p); + } else + log_debug("Invalid LLMNR UDP packet, ignoring."); + + return 0; +} + +int manager_llmnr_ipv4_udp_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(LLMNR_PORT), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; + int r; + + assert(m); + + if (m->llmnr_ipv4_udp_fd >= 0) + return m->llmnr_ipv4_udp_fd; + + m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv4_udp_fd < 0) + return -errno; + + /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* Disable Don't-Fragment bit in the IP header */ + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, m->llmnr_ipv4_udp_fd, EPOLLIN, on_llmnr_packet, m); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(m->llmnr_ipv4_udp_event_source, "llmnr-ipv4-udp"); + + return m->llmnr_ipv4_udp_fd; + +fail: + m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); + return r; +} + +int manager_llmnr_ipv6_udp_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(LLMNR_PORT), + }; + static const int one = 1, ttl = 255; + int r; + + assert(m); + + if (m->llmnr_ipv6_udp_fd >= 0) + return m->llmnr_ipv6_udp_fd; + + m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv6_udp_fd < 0) + return -errno; + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, m->llmnr_ipv6_udp_fd, EPOLLIN, on_llmnr_packet, m); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(m->llmnr_ipv6_udp_event_source, "llmnr-ipv6-udp"); + + return m->llmnr_ipv6_udp_fd; + +fail: + m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); + return r; +} + +static int on_llmnr_stream_packet(DnsStream *s) { + DnsScope *scope; + + assert(s); + assert(s->read_packet); + + scope = manager_find_scope(s->manager, s->read_packet); + if (!scope) + log_warning("Got LLMNR TCP packet on unknown scope. Ignoring."); + else if (dns_packet_validate_query(s->read_packet) > 0) { + log_debug("Got LLMNR TCP query packet for id %u", DNS_PACKET_ID(s->read_packet)); + + dns_scope_process_query(scope, s, s->read_packet); + } else + log_debug("Invalid LLMNR TCP packet, ignoring."); + + dns_stream_unref(s); + return 0; +} + +static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + DnsStream *stream; + Manager *m = userdata; + int cfd, r; + + cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (cfd < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd); + if (r < 0) { + safe_close(cfd); + return r; + } + + stream->on_packet = on_llmnr_stream_packet; + return 0; +} + +int manager_llmnr_ipv4_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(LLMNR_PORT), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT; + int r; + + assert(m); + + if (m->llmnr_ipv4_tcp_fd >= 0) + return m->llmnr_ipv4_tcp_fd; + + m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv4_tcp_fd < 0) + return -errno; + + /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* Disable Don't-Fragment bit in the IP header */ + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(m->llmnr_ipv4_tcp_event_source, "llmnr-ipv4-tcp"); + + return m->llmnr_ipv4_tcp_fd; + +fail: + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + return r; +} + +int manager_llmnr_ipv6_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(LLMNR_PORT), + }; + static const int one = 1; + int r; + + assert(m); + + if (m->llmnr_ipv6_tcp_fd >= 0) + return m->llmnr_ipv6_tcp_fd; + + m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv6_tcp_fd < 0) + return -errno; + + /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(m->llmnr_ipv6_tcp_event_source, "llmnr-ipv6-tcp"); + + return m->llmnr_ipv6_tcp_fd; + +fail: + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); + return r; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-llmnr.h b/src/grp-resolve/systemd-resolved/resolved-llmnr.h new file mode 100644 index 0000000000..8133582fa7 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-llmnr.h @@ -0,0 +1,32 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +#define LLMNR_PORT 5355 + +int manager_llmnr_ipv4_udp_fd(Manager *m); +int manager_llmnr_ipv6_udp_fd(Manager *m); +int manager_llmnr_ipv4_tcp_fd(Manager *m); +int manager_llmnr_ipv6_tcp_fd(Manager *m); + +void manager_llmnr_stop(Manager *m); +int manager_llmnr_start(Manager *m); diff --git a/src/grp-resolve/systemd-resolved/resolved-manager.c b/src/grp-resolve/systemd-resolved/resolved-manager.c new file mode 100644 index 0000000000..67bbe30f13 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-manager.c @@ -0,0 +1,1378 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <netinet/in.h> +#include <poll.h> +#include <sys/ioctl.h> + +#include "sd-netlink/netlink-util.h" +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/dirent-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio-label.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/ordered-set.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/utf8.h" +#include "systemd-network/network-internal.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-bus.h" +#include "resolved-conf.h" +#include "resolved-dns-stub.h" +#include "resolved-etc-hosts.h" +#include "resolved-llmnr.h" +#include "resolved-manager.h" +#include "resolved-mdns.h" +#include "resolved-resolv-conf.h" + +#define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC) + +static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) { + Manager *m = userdata; + uint16_t type; + Link *l; + int ifindex, r; + + assert(rtnl); + assert(m); + assert(mm); + + r = sd_netlink_message_get_type(mm, &type); + if (r < 0) + goto fail; + + r = sd_rtnl_message_link_get_ifindex(mm, &ifindex); + if (r < 0) + goto fail; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + + switch (type) { + + case RTM_NEWLINK:{ + bool is_new = !l; + + if (!l) { + r = link_new(m, &l, ifindex); + if (r < 0) + goto fail; + } + + r = link_process_rtnl(l, mm); + if (r < 0) + goto fail; + + r = link_update(l); + if (r < 0) + goto fail; + + if (is_new) + log_debug("Found new link %i/%s", ifindex, l->name); + + break; + } + + case RTM_DELLINK: + if (l) { + log_debug("Removing link %i/%s", l->ifindex, l->name); + link_remove_user(l); + link_free(l); + } + + break; + } + + return 0; + +fail: + log_warning_errno(r, "Failed to process RTNL link message: %m"); + return 0; +} + +static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) { + Manager *m = userdata; + union in_addr_union address; + uint16_t type; + int r, ifindex, family; + LinkAddress *a; + Link *l; + + assert(rtnl); + assert(mm); + assert(m); + + r = sd_netlink_message_get_type(mm, &type); + if (r < 0) + goto fail; + + r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex); + if (r < 0) + goto fail; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) + return 0; + + r = sd_rtnl_message_addr_get_family(mm, &family); + if (r < 0) + goto fail; + + switch (family) { + + case AF_INET: + r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in); + if (r < 0) { + r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in); + if (r < 0) + goto fail; + } + + break; + + case AF_INET6: + r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6); + if (r < 0) { + r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6); + if (r < 0) + goto fail; + } + + break; + + default: + return 0; + } + + a = link_find_address(l, family, &address); + + switch (type) { + + case RTM_NEWADDR: + + if (!a) { + r = link_address_new(l, &a, family, &address); + if (r < 0) + return r; + } + + r = link_address_update_rtnl(a, mm); + if (r < 0) + return r; + + break; + + case RTM_DELADDR: + link_address_free(a); + break; + } + + return 0; + +fail: + log_warning_errno(r, "Failed to process RTNL address message: %m"); + return 0; +} + +static int manager_rtnl_listen(Manager *m) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL; + sd_netlink_message *i; + int r; + + assert(m); + + /* First, subscribe to interfaces coming and going */ + r = sd_netlink_open(&m->rtnl); + if (r < 0) + return r; + + r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT); + if (r < 0) + return r; + + r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m); + if (r < 0) + return r; + + r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m); + if (r < 0) + return r; + + r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m); + if (r < 0) + return r; + + r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m); + if (r < 0) + return r; + + /* Then, enumerate all links */ + r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0); + if (r < 0) + return r; + + r = sd_netlink_message_request_dump(req, true); + if (r < 0) + return r; + + r = sd_netlink_call(m->rtnl, req, 0, &reply); + if (r < 0) + return r; + + for (i = reply; i; i = sd_netlink_message_next(i)) { + r = manager_process_link(m->rtnl, i, m); + if (r < 0) + return r; + } + + req = sd_netlink_message_unref(req); + reply = sd_netlink_message_unref(reply); + + /* Finally, enumerate all addresses, too */ + r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC); + if (r < 0) + return r; + + r = sd_netlink_message_request_dump(req, true); + if (r < 0) + return r; + + r = sd_netlink_call(m->rtnl, req, 0, &reply); + if (r < 0) + return r; + + for (i = reply; i; i = sd_netlink_message_next(i)) { + r = manager_process_address(m->rtnl, i, m); + if (r < 0) + return r; + } + + return r; +} + +static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + Manager *m = userdata; + Iterator i; + Link *l; + int r; + + assert(m); + + sd_network_monitor_flush(m->network_monitor); + + HASHMAP_FOREACH(l, m->links, i) { + r = link_update(l); + if (r < 0) + log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); + } + + (void) manager_write_resolv_conf(m); + + return 0; +} + +static int manager_network_monitor_listen(Manager *m) { + int r, fd, events; + + assert(m); + + r = sd_network_monitor_new(&m->network_monitor, NULL); + if (r < 0) + return r; + + fd = sd_network_monitor_get_fd(m->network_monitor); + if (fd < 0) + return fd; + + events = sd_network_monitor_get_events(m->network_monitor); + if (events < 0) + return events; + + r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m); + if (r < 0) + return r; + + r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5); + if (r < 0) + return r; + + (void) sd_event_source_set_description(m->network_event_source, "network-monitor"); + + return 0; +} + +static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) { + _cleanup_free_ char *h = NULL, *n = NULL; + char label[DNS_LABEL_MAX]; + const char *p; + int r, k; + + assert(llmnr_hostname); + assert(mdns_hostname); + + /* Extract and normalize the first label of the locally + * configured hostname, and check it's not "localhost". */ + + h = gethostname_malloc(); + if (!h) + return log_oom(); + + p = h; + r = dns_label_unescape(&p, label, sizeof(label)); + if (r < 0) + return log_error_errno(r, "Failed to unescape host name: %m"); + if (r == 0) { + log_error("Couldn't find a single label in hosntame."); + return -EINVAL; + } + + k = dns_label_undo_idna(label, r, label, sizeof(label)); + if (k < 0) + return log_error_errno(k, "Failed to undo IDNA: %m"); + if (k > 0) + r = k; + + if (!utf8_is_valid(label)) { + log_error("System hostname is not UTF-8 clean."); + return -EINVAL; + } + + r = dns_label_escape_new(label, r, &n); + if (r < 0) + return log_error_errno(r, "Failed to escape host name: %m"); + + if (is_localhost(n)) { + log_debug("System hostname is 'localhost', ignoring."); + return -EINVAL; + } + + r = dns_name_concat(n, "local", mdns_hostname); + if (r < 0) + return log_error_errno(r, "Failed to determine mDNS hostname: %m"); + + *llmnr_hostname = n; + n = NULL; + + return 0; +} + +static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) { + _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL; + Manager *m = userdata; + int r; + + assert(m); + + r = determine_hostname(&llmnr_hostname, &mdns_hostname); + if (r < 0) + return 0; /* ignore invalid hostnames */ + + if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname)) + return 0; + + log_info("System hostname changed to '%s'.", llmnr_hostname); + + free(m->llmnr_hostname); + free(m->mdns_hostname); + + m->llmnr_hostname = llmnr_hostname; + m->mdns_hostname = mdns_hostname; + + llmnr_hostname = mdns_hostname = NULL; + + manager_refresh_rrs(m); + + return 0; +} + +static int manager_watch_hostname(Manager *m) { + int r; + + assert(m); + + m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY); + if (m->hostname_fd < 0) { + log_warning_errno(errno, "Failed to watch hostname: %m"); + return 0; + } + + r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m); + if (r < 0) { + if (r == -EPERM) + /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */ + m->hostname_fd = safe_close(m->hostname_fd); + else + return log_error_errno(r, "Failed to add hostname event source: %m"); + } + + (void) sd_event_source_set_description(m->hostname_event_source, "hostname"); + + r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname); + if (r < 0) { + log_info("Defaulting to hostname 'gnu-linux'."); + m->llmnr_hostname = strdup("gnu-linux"); + if (!m->llmnr_hostname) + return log_oom(); + + m->mdns_hostname = strdup("gnu-linux.local"); + if (!m->mdns_hostname) + return log_oom(); + } else + log_info("Using system hostname '%s'.", m->llmnr_hostname); + + return 0; +} + +static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + _cleanup_free_ char *buffer = NULL; + _cleanup_fclose_ FILE *f = NULL; + Manager *m = userdata; + size_t size = 0; + DnsScope *scope; + + assert(s); + assert(si); + assert(m); + + f = open_memstream(&buffer, &size); + if (!f) + return log_oom(); + + LIST_FOREACH(scopes, scope, m->dns_scopes) + dns_scope_dump(scope, f); + + if (fflush_and_check(f) < 0) + return log_oom(); + + log_dump(LOG_INFO, buffer); + return 0; +} + +static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(si); + assert(m); + + manager_flush_caches(m); + + return 0; +} + +int manager_new(Manager **ret) { + _cleanup_(manager_freep) Manager *m = NULL; + int r; + + assert(ret); + + m = new0(Manager, 1); + if (!m) + return -ENOMEM; + + m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; + m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; + m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1; + m->dns_stub_udp_fd = m->dns_stub_tcp_fd = -1; + m->hostname_fd = -1; + + m->llmnr_support = RESOLVE_SUPPORT_YES; + m->mdns_support = RESOLVE_SUPPORT_NO; + m->dnssec_mode = DEFAULT_DNSSEC_MODE; + m->enable_cache = true; + m->dns_stub_listener_mode = DNS_STUB_LISTENER_UDP; + m->read_resolv_conf = true; + m->need_builtin_fallbacks = true; + m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY; + + r = dns_trust_anchor_load(&m->trust_anchor); + if (r < 0) + return r; + + r = manager_parse_config_file(m); + if (r < 0) + return r; + + r = sd_event_default(&m->event); + if (r < 0) + return r; + + sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); + sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); + + sd_event_set_watchdog(m->event, true); + + r = manager_watch_hostname(m); + if (r < 0) + return r; + + r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC); + if (r < 0) + return r; + + r = manager_network_monitor_listen(m); + if (r < 0) + return r; + + r = manager_rtnl_listen(m); + if (r < 0) + return r; + + r = manager_connect_bus(m); + if (r < 0) + return r; + + (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m); + (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m); + + manager_cleanup_saved_user(m); + + *ret = m; + m = NULL; + + return 0; +} + +int manager_start(Manager *m) { + int r; + + assert(m); + + r = manager_dns_stub_start(m); + if (r < 0) + return r; + + r = manager_llmnr_start(m); + if (r < 0) + return r; + + r = manager_mdns_start(m); + if (r < 0) + return r; + + return 0; +} + +Manager *manager_free(Manager *m) { + Link *l; + + if (!m) + return NULL; + + dns_server_unlink_all(m->dns_servers); + dns_server_unlink_all(m->fallback_dns_servers); + dns_search_domain_unlink_all(m->search_domains); + + while ((l = hashmap_first(m->links))) + link_free(l); + + while (m->dns_queries) + dns_query_free(m->dns_queries); + + dns_scope_free(m->unicast_scope); + + /* At this point only orphaned streams should remain. All others should have been freed already by their + * owners */ + while (m->dns_streams) + dns_stream_unref(m->dns_streams); + + hashmap_free(m->links); + hashmap_free(m->dns_transactions); + + sd_event_source_unref(m->network_event_source); + sd_network_monitor_unref(m->network_monitor); + + sd_netlink_unref(m->rtnl); + sd_event_source_unref(m->rtnl_event_source); + + manager_llmnr_stop(m); + manager_mdns_stop(m); + manager_dns_stub_stop(m); + + sd_bus_slot_unref(m->prepare_for_sleep_slot); + sd_event_source_unref(m->bus_retry_event_source); + sd_bus_unref(m->bus); + + sd_event_source_unref(m->sigusr1_event_source); + sd_event_source_unref(m->sigusr2_event_source); + + sd_event_unref(m->event); + + dns_resource_key_unref(m->llmnr_host_ipv4_key); + dns_resource_key_unref(m->llmnr_host_ipv6_key); + + sd_event_source_unref(m->hostname_event_source); + safe_close(m->hostname_fd); + free(m->llmnr_hostname); + free(m->mdns_hostname); + + dns_trust_anchor_flush(&m->trust_anchor); + manager_etc_hosts_flush(m); + + return mfree(m); +} + +int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + union { + struct cmsghdr header; /* For alignment */ + uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) + + CMSG_SPACE(int) /* ttl/hoplimit */ + + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; + } control; + union sockaddr_union sa; + struct msghdr mh = {}; + struct cmsghdr *cmsg; + struct iovec iov; + ssize_t ms, l; + int r; + + assert(m); + assert(fd >= 0); + assert(ret); + + ms = next_datagram_size_fd(fd); + if (ms < 0) + return ms; + + r = dns_packet_new(&p, protocol, ms); + if (r < 0) + return r; + + iov.iov_base = DNS_PACKET_DATA(p); + iov.iov_len = p->allocated; + + mh.msg_name = &sa.sa; + mh.msg_namelen = sizeof(sa); + mh.msg_iov = &iov; + mh.msg_iovlen = 1; + mh.msg_control = &control; + mh.msg_controllen = sizeof(control); + + l = recvmsg(fd, &mh, 0); + if (l == 0) + return 0; + if (l < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + assert(!(mh.msg_flags & MSG_CTRUNC)); + assert(!(mh.msg_flags & MSG_TRUNC)); + + p->size = (size_t) l; + + p->family = sa.sa.sa_family; + p->ipproto = IPPROTO_UDP; + if (p->family == AF_INET) { + p->sender.in = sa.in.sin_addr; + p->sender_port = be16toh(sa.in.sin_port); + } else if (p->family == AF_INET6) { + p->sender.in6 = sa.in6.sin6_addr; + p->sender_port = be16toh(sa.in6.sin6_port); + p->ifindex = sa.in6.sin6_scope_id; + } else + return -EAFNOSUPPORT; + + CMSG_FOREACH(cmsg, &mh) { + + if (cmsg->cmsg_level == IPPROTO_IPV6) { + assert(p->family == AF_INET6); + + switch (cmsg->cmsg_type) { + + case IPV6_PKTINFO: { + struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); + + if (p->ifindex <= 0) + p->ifindex = i->ipi6_ifindex; + + p->destination.in6 = i->ipi6_addr; + break; + } + + case IPV6_HOPLIMIT: + p->ttl = *(int *) CMSG_DATA(cmsg); + break; + + } + } else if (cmsg->cmsg_level == IPPROTO_IP) { + assert(p->family == AF_INET); + + switch (cmsg->cmsg_type) { + + case IP_PKTINFO: { + struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); + + if (p->ifindex <= 0) + p->ifindex = i->ipi_ifindex; + + p->destination.in = i->ipi_addr; + break; + } + + case IP_TTL: + p->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + } + } + + /* The Linux kernel sets the interface index to the loopback + * device if the packet came from the local host since it + * avoids the routing table in such a case. Let's unset the + * interface index in such a case. */ + if (p->ifindex == LOOPBACK_IFINDEX) + p->ifindex = 0; + + if (protocol != DNS_PROTOCOL_DNS) { + /* If we don't know the interface index still, we look for the + * first local interface with a matching address. Yuck! */ + if (p->ifindex <= 0) + p->ifindex = manager_find_ifindex(m, p->family, &p->destination); + } + + *ret = p; + p = NULL; + + return 1; +} + +static int sendmsg_loop(int fd, struct msghdr *mh, int flags) { + int r; + + assert(fd >= 0); + assert(mh); + + for (;;) { + if (sendmsg(fd, mh, flags) >= 0) + return 0; + + if (errno == EINTR) + continue; + + if (errno != EAGAIN) + return -errno; + + r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); + if (r < 0) + return r; + if (r == 0) + return -ETIMEDOUT; + } +} + +static int write_loop(int fd, void *message, size_t length) { + int r; + + assert(fd >= 0); + assert(message); + + for (;;) { + if (write(fd, message, length) >= 0) + return 0; + + if (errno == EINTR) + continue; + + if (errno != EAGAIN) + return -errno; + + r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); + if (r < 0) + return r; + if (r == 0) + return -ETIMEDOUT; + } +} + +int manager_write(Manager *m, int fd, DnsPacket *p) { + int r; + + log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p)); + + r = write_loop(fd, DNS_PACKET_DATA(p), p->size); + if (r < 0) + return r; + + return 0; +} + +static int manager_ipv4_send( + Manager *m, + int fd, + int ifindex, + const struct in_addr *destination, + uint16_t port, + const struct in_addr *source, + DnsPacket *p) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + }; + union { + struct cmsghdr header; /* For alignment */ + uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))]; + } control; + struct msghdr mh = {}; + struct iovec iov; + + assert(m); + assert(fd >= 0); + assert(destination); + assert(port > 0); + assert(p); + + iov.iov_base = DNS_PACKET_DATA(p); + iov.iov_len = p->size; + + sa.in.sin_addr = *destination; + sa.in.sin_port = htobe16(port), + + mh.msg_iov = &iov; + mh.msg_iovlen = 1; + mh.msg_name = &sa.sa; + mh.msg_namelen = sizeof(sa.in); + + if (ifindex > 0) { + struct cmsghdr *cmsg; + struct in_pktinfo *pi; + + zero(control); + + mh.msg_control = &control; + mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_len = mh.msg_controllen; + cmsg->cmsg_level = IPPROTO_IP; + cmsg->cmsg_type = IP_PKTINFO; + + pi = (struct in_pktinfo*) CMSG_DATA(cmsg); + pi->ipi_ifindex = ifindex; + + if (source) + pi->ipi_spec_dst = *source; + } + + return sendmsg_loop(fd, &mh, 0); +} + +static int manager_ipv6_send( + Manager *m, + int fd, + int ifindex, + const struct in6_addr *destination, + uint16_t port, + const struct in6_addr *source, + DnsPacket *p) { + + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + }; + union { + struct cmsghdr header; /* For alignment */ + uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))]; + } control; + struct msghdr mh = {}; + struct iovec iov; + + assert(m); + assert(fd >= 0); + assert(destination); + assert(port > 0); + assert(p); + + iov.iov_base = DNS_PACKET_DATA(p); + iov.iov_len = p->size; + + sa.in6.sin6_addr = *destination; + sa.in6.sin6_port = htobe16(port), + sa.in6.sin6_scope_id = ifindex; + + mh.msg_iov = &iov; + mh.msg_iovlen = 1; + mh.msg_name = &sa.sa; + mh.msg_namelen = sizeof(sa.in6); + + if (ifindex > 0) { + struct cmsghdr *cmsg; + struct in6_pktinfo *pi; + + zero(control); + + mh.msg_control = &control; + mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_len = mh.msg_controllen; + cmsg->cmsg_level = IPPROTO_IPV6; + cmsg->cmsg_type = IPV6_PKTINFO; + + pi = (struct in6_pktinfo*) CMSG_DATA(cmsg); + pi->ipi6_ifindex = ifindex; + + if (source) + pi->ipi6_addr = *source; + } + + return sendmsg_loop(fd, &mh, 0); +} + +int manager_send( + Manager *m, + int fd, + int ifindex, + int family, + const union in_addr_union *destination, + uint16_t port, + const union in_addr_union *source, + DnsPacket *p) { + + assert(m); + assert(fd >= 0); + assert(destination); + assert(port > 0); + assert(p); + + log_debug("Sending %s packet with id %" PRIu16 " on interface %i/%s.", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family)); + + if (family == AF_INET) + return manager_ipv4_send(m, fd, ifindex, &destination->in, port, &source->in, p); + if (family == AF_INET6) + return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, p); + + return -EAFNOSUPPORT; +} + +uint32_t manager_find_mtu(Manager *m) { + uint32_t mtu = 0; + Link *l; + Iterator i; + + /* If we don't know on which link a DNS packet would be + * delivered, let's find the largest MTU that works on all + * interfaces we know of */ + + HASHMAP_FOREACH(l, m->links, i) { + if (l->mtu <= 0) + continue; + + if (mtu <= 0 || l->mtu < mtu) + mtu = l->mtu; + } + + return mtu; +} + +int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { + LinkAddress *a; + + assert(m); + + a = manager_find_link_address(m, family, in_addr); + if (a) + return a->link->ifindex; + + return 0; +} + +void manager_refresh_rrs(Manager *m) { + Iterator i; + Link *l; + + assert(m); + + m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key); + m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key); + + HASHMAP_FOREACH(l, m->links, i) { + link_add_rrs(l, true); + link_add_rrs(l, false); + } +} + +int manager_next_hostname(Manager *m) { + const char *p; + uint64_t u, a; + char *h, *k; + int r; + + assert(m); + + p = strchr(m->llmnr_hostname, 0); + assert(p); + + while (p > m->llmnr_hostname) { + if (!strchr("0123456789", p[-1])) + break; + + p--; + } + + if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0) + u = 1; + + /* Add a random number to the old value. This way we can avoid + * that two hosts pick the same hostname, win on IPv4 and lose + * on IPv6 (or vice versa), and pick the same hostname + * replacement hostname, ad infinitum. We still want the + * numbers to go up monotonically, hence we just add a random + * value 1..10 */ + + random_bytes(&a, sizeof(a)); + u += 1 + a % 10; + + if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0) + return -ENOMEM; + + r = dns_name_concat(h, "local", &k); + if (r < 0) { + free(h); + return r; + } + + log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h); + + free(m->llmnr_hostname); + m->llmnr_hostname = h; + + free(m->mdns_hostname); + m->mdns_hostname = k; + + manager_refresh_rrs(m); + + return 0; +} + +LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) { + Iterator i; + Link *l; + + assert(m); + + HASHMAP_FOREACH(l, m->links, i) { + LinkAddress *a; + + a = link_find_address(l, family, in_addr); + if (a) + return a; + } + + return NULL; +} + +bool manager_our_packet(Manager *m, DnsPacket *p) { + assert(m); + assert(p); + + return !!manager_find_link_address(m, p->family, &p->sender); +} + +DnsScope* manager_find_scope(Manager *m, DnsPacket *p) { + Link *l; + + assert(m); + assert(p); + + l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); + if (!l) + return NULL; + + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + if (p->family == AF_INET) + return l->llmnr_ipv4_scope; + else if (p->family == AF_INET6) + return l->llmnr_ipv6_scope; + + break; + + case DNS_PROTOCOL_MDNS: + if (p->family == AF_INET) + return l->mdns_ipv4_scope; + else if (p->family == AF_INET6) + return l->mdns_ipv6_scope; + + break; + + default: + break; + } + + return NULL; +} + +void manager_verify_all(Manager *m) { + DnsScope *s; + + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) + dns_zone_verify_all(&s->zone); +} + +int manager_is_own_hostname(Manager *m, const char *name) { + int r; + + assert(m); + assert(name); + + if (m->llmnr_hostname) { + r = dns_name_equal(name, m->llmnr_hostname); + if (r != 0) + return r; + } + + if (m->mdns_hostname) + return dns_name_equal(name, m->mdns_hostname); + + return 0; +} + +int manager_compile_dns_servers(Manager *m, OrderedSet **dns) { + DnsServer *s; + Iterator i; + Link *l; + int r; + + assert(m); + assert(dns); + + r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops); + if (r < 0) + return r; + + /* First add the system-wide servers and domains */ + LIST_FOREACH(servers, s, m->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + /* Then, add the per-link servers */ + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(servers, s, l->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + /* If we found nothing, add the fallback servers */ + if (ordered_set_isempty(*dns)) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + return 0; +} + +/* filter_route is a tri-state: + * < 0: no filtering + * = 0 or false: return only domains which should be used for searching + * > 0 or true: return only domains which are for routing only + */ +int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) { + DnsSearchDomain *d; + Iterator i; + Link *l; + int r; + + assert(m); + assert(domains); + + r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, m->search_domains) { + + if (filter_route >= 0 && + d->route_only != !!filter_route) + continue; + + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + HASHMAP_FOREACH(l, m->links, i) { + + LIST_FOREACH(domains, d, l->search_domains) { + + if (filter_route >= 0 && + d->route_only != !!filter_route) + continue; + + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + return 0; +} + +DnssecMode manager_get_dnssec_mode(Manager *m) { + assert(m); + + if (m->dnssec_mode != _DNSSEC_MODE_INVALID) + return m->dnssec_mode; + + return DNSSEC_NO; +} + +bool manager_dnssec_supported(Manager *m) { + DnsServer *server; + Iterator i; + Link *l; + + assert(m); + + if (manager_get_dnssec_mode(m) == DNSSEC_NO) + return false; + + server = manager_get_dns_server(m); + if (server && !dns_server_dnssec_supported(server)) + return false; + + HASHMAP_FOREACH(l, m->links, i) + if (!link_dnssec_supported(l)) + return false; + + return true; +} + +void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) { + + assert(verdict >= 0); + assert(verdict < _DNSSEC_VERDICT_MAX); + + if (log_get_max_level() >= LOG_DEBUG) { + char s[DNS_RESOURCE_KEY_STRING_MAX]; + + log_debug("Found verdict for lookup %s: %s", + dns_resource_key_to_string(key, s, sizeof s), + dnssec_verdict_to_string(verdict)); + } + + m->n_dnssec_verdict[verdict]++; +} + +bool manager_routable(Manager *m, int family) { + Iterator i; + Link *l; + + assert(m); + + /* Returns true if the host has at least one interface with a routable address of the specified type */ + + HASHMAP_FOREACH(l, m->links, i) + if (link_relevant(l, family, false)) + return true; + + return false; +} + +void manager_flush_caches(Manager *m) { + DnsScope *scope; + + assert(m); + + LIST_FOREACH(scopes, scope, m->dns_scopes) + dns_cache_flush(&scope->cache); + + log_info("Flushed all caches."); +} + +void manager_cleanup_saved_user(Manager *m) { + _cleanup_closedir_ DIR *d = NULL; + struct dirent *de; + int r; + + assert(m); + + /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface + * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can + * be restarted without losing this data. */ + + d = opendir("/run/systemd/resolve/netif/"); + if (!d) { + if (errno == ENOENT) + return; + + log_warning_errno(errno, "Failed to open interface directory: %m"); + return; + } + + FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) { + _cleanup_free_ char *p = NULL; + int ifindex; + Link *l; + + if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG)) + continue; + + if (STR_IN_SET(de->d_name, ".", "..")) + continue; + + r = parse_ifindex(de->d_name, &ifindex); + if (r < 0) /* Probably some temporary file from a previous run. Delete it */ + goto rm; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) /* link vanished */ + goto rm; + + if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */ + goto rm; + + continue; + + rm: + p = strappend("/run/systemd/resolve/netif/", de->d_name); + if (!p) { + log_oom(); + return; + } + + (void) unlink(p); + } +} diff --git a/src/grp-resolve/systemd-resolved/resolved-manager.h b/src/grp-resolve/systemd-resolved/resolved-manager.h new file mode 100644 index 0000000000..4e9dcd51f1 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-manager.h @@ -0,0 +1,185 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-event.h> + +#include "systemd-basic/hashmap.h" +#include "systemd-basic/list.h" +#include "systemd-basic/ordered-set.h" +#include "systemd-shared/resolve-util.h" +#include "systemd-staging/sd-netlink.h" +#include "systemd-staging/sd-network.h" + +typedef struct Manager Manager; + +#include "resolved-conf.h" +#include "resolved-dns-query.h" +#include "resolved-dns-search-domain.h" +#include "resolved-dns-server.h" +#include "resolved-dns-stream.h" +#include "resolved-dns-trust-anchor.h" +#include "resolved-link.h" + +#define MANAGER_SEARCH_DOMAINS_MAX 32 +#define MANAGER_DNS_SERVERS_MAX 32 + +struct Manager { + sd_event *event; + + ResolveSupport llmnr_support; + ResolveSupport mdns_support; + DnssecMode dnssec_mode; + bool enable_cache; + DnsStubListenerMode dns_stub_listener_mode; + + /* Network */ + Hashmap *links; + + sd_netlink *rtnl; + sd_event_source *rtnl_event_source; + + sd_network_monitor *network_monitor; + sd_event_source *network_event_source; + + /* DNS query management */ + Hashmap *dns_transactions; + LIST_HEAD(DnsQuery, dns_queries); + unsigned n_dns_queries; + + LIST_HEAD(DnsStream, dns_streams); + unsigned n_dns_streams; + + /* Unicast dns */ + LIST_HEAD(DnsServer, dns_servers); + LIST_HEAD(DnsServer, fallback_dns_servers); + unsigned n_dns_servers; /* counts both main and fallback */ + DnsServer *current_dns_server; + + LIST_HEAD(DnsSearchDomain, search_domains); + unsigned n_search_domains; + + bool need_builtin_fallbacks:1; + + bool read_resolv_conf:1; + usec_t resolv_conf_mtime; + + DnsTrustAnchor trust_anchor; + + LIST_HEAD(DnsScope, dns_scopes); + DnsScope *unicast_scope; + + /* LLMNR */ + int llmnr_ipv4_udp_fd; + int llmnr_ipv6_udp_fd; + int llmnr_ipv4_tcp_fd; + int llmnr_ipv6_tcp_fd; + + sd_event_source *llmnr_ipv4_udp_event_source; + sd_event_source *llmnr_ipv6_udp_event_source; + sd_event_source *llmnr_ipv4_tcp_event_source; + sd_event_source *llmnr_ipv6_tcp_event_source; + + /* mDNS */ + int mdns_ipv4_fd; + int mdns_ipv6_fd; + + sd_event_source *mdns_ipv4_event_source; + sd_event_source *mdns_ipv6_event_source; + + /* dbus */ + sd_bus *bus; + sd_event_source *bus_retry_event_source; + + /* The hostname we publish on LLMNR and mDNS */ + char *llmnr_hostname; + char *mdns_hostname; + DnsResourceKey *llmnr_host_ipv4_key; + DnsResourceKey *llmnr_host_ipv6_key; + + /* Watch the system hostname */ + int hostname_fd; + sd_event_source *hostname_event_source; + + /* Watch for system suspends */ + sd_bus_slot *prepare_for_sleep_slot; + + sd_event_source *sigusr1_event_source; + sd_event_source *sigusr2_event_source; + + unsigned n_transactions_total; + unsigned n_dnssec_verdict[_DNSSEC_VERDICT_MAX]; + + /* Data from /etc/hosts */ + Set* etc_hosts_by_address; + Hashmap* etc_hosts_by_name; + usec_t etc_hosts_last, etc_hosts_mtime; + + /* Local DNS stub on 127.0.0.53:53 */ + int dns_stub_udp_fd; + int dns_stub_tcp_fd; + + sd_event_source *dns_stub_udp_event_source; + sd_event_source *dns_stub_tcp_event_source; +}; + +/* Manager */ + +int manager_new(Manager **ret); +Manager* manager_free(Manager *m); + +int manager_start(Manager *m); + +uint32_t manager_find_mtu(Manager *m); + +int manager_write(Manager *m, int fd, DnsPacket *p); +int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *destination, uint16_t port, const union in_addr_union *source, DnsPacket *p); +int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret); + +int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr); +LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr); + +void manager_refresh_rrs(Manager *m); +int manager_next_hostname(Manager *m); + +bool manager_our_packet(Manager *m, DnsPacket *p); +DnsScope* manager_find_scope(Manager *m, DnsPacket *p); + +void manager_verify_all(Manager *m); + +DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); + +#define EXTRA_CMSG_SPACE 1024 + +int manager_is_own_hostname(Manager *m, const char *name); + +int manager_compile_dns_servers(Manager *m, OrderedSet **servers); +int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route); + +DnssecMode manager_get_dnssec_mode(Manager *m); +bool manager_dnssec_supported(Manager *m); + +void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key); + +bool manager_routable(Manager *m, int family); + +void manager_flush_caches(Manager *m); + +void manager_cleanup_saved_user(Manager *m); diff --git a/src/grp-resolve/systemd-resolved/resolved-mdns.c b/src/grp-resolve/systemd-resolved/resolved-mdns.c new file mode 100644 index 0000000000..f810019763 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-mdns.c @@ -0,0 +1,288 @@ +/*** + This file is part of systemd. + + Copyright 2015 Daniel Mack + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <arpa/inet.h> +#include <netinet/in.h> +#include <resolv.h> + +#include "systemd-basic/fd-util.h" + +#include "resolved-manager.h" +#include "resolved-mdns.h" + +void manager_mdns_stop(Manager *m) { + assert(m); + + m->mdns_ipv4_event_source = sd_event_source_unref(m->mdns_ipv4_event_source); + m->mdns_ipv4_fd = safe_close(m->mdns_ipv4_fd); + + m->mdns_ipv6_event_source = sd_event_source_unref(m->mdns_ipv6_event_source); + m->mdns_ipv6_fd = safe_close(m->mdns_ipv6_fd); +} + +int manager_mdns_start(Manager *m) { + int r; + + assert(m); + + if (m->mdns_support == RESOLVE_SUPPORT_NO) + return 0; + + r = manager_mdns_ipv4_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + if (socket_ipv6_is_supported()) { + r = manager_mdns_ipv6_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + } + + return 0; + +eaddrinuse: + log_warning("There appears to be another mDNS responder running. Turning off mDNS support."); + m->mdns_support = RESOLVE_SUPPORT_NO; + manager_mdns_stop(m); + + return 0; +} + +static int on_mdns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + Manager *m = userdata; + DnsScope *scope; + int r; + + r = manager_recv(m, fd, DNS_PROTOCOL_MDNS, &p); + if (r <= 0) + return r; + + scope = manager_find_scope(m, p); + if (!scope) { + log_warning("Got mDNS UDP packet on unknown scope. Ignoring."); + return 0; + } + + if (dns_packet_validate_reply(p) > 0) { + DnsResourceRecord *rr; + + log_debug("Got mDNS reply packet"); + + /* + * mDNS is different from regular DNS and LLMNR with regard to handling responses. + * While on other protocols, we can ignore every answer that doesn't match a question + * we broadcast earlier, RFC6762, section 18.1 recommends looking at and caching all + * incoming information, regardless of the DNS packet ID. + * + * Hence, extract the packet here, and try to find a transaction for answer the we got + * and complete it. Also store the new information in scope's cache. + */ + r = dns_packet_extract(p); + if (r < 0) { + log_debug("mDNS packet extraction failed."); + return 0; + } + + dns_scope_check_conflicts(scope, p); + + DNS_ANSWER_FOREACH(rr, p->answer) { + const char *name = dns_resource_key_name(rr->key); + DnsTransaction *t; + + /* If the received reply packet contains ANY record that is not .local or .in-addr.arpa, + * we assume someone's playing tricks on us and discard the packet completely. */ + if (!(dns_name_endswith(name, "in-addr.arpa") > 0 || + dns_name_endswith(name, "local") > 0)) + return 0; + + t = dns_scope_find_transaction(scope, rr->key, false); + if (t) + dns_transaction_process_reply(t, p); + } + + dns_cache_put(&scope->cache, NULL, DNS_PACKET_RCODE(p), p->answer, false, (uint32_t) -1, 0, p->family, &p->sender); + + } else if (dns_packet_validate_query(p) > 0) { + log_debug("Got mDNS query packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_process_query(scope, NULL, p); + } else + log_debug("Invalid mDNS UDP packet."); + + return 0; +} + +int manager_mdns_ipv4_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(MDNS_PORT), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; + int r; + + assert(m); + + if (m->mdns_ipv4_fd >= 0) + return m->mdns_ipv4_fd; + + m->mdns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->mdns_ipv4_fd < 0) + return -errno; + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* Disable Don't-Fragment bit in the IP header */ + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->mdns_ipv4_event_source, m->mdns_ipv4_fd, EPOLLIN, on_mdns_packet, m); + if (r < 0) + goto fail; + + return m->mdns_ipv4_fd; + +fail: + m->mdns_ipv4_fd = safe_close(m->mdns_ipv4_fd); + return r; +} + +int manager_mdns_ipv6_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(MDNS_PORT), + }; + static const int one = 1, ttl = 255; + int r; + + assert(m); + + if (m->mdns_ipv6_fd >= 0) + return m->mdns_ipv6_fd; + + m->mdns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->mdns_ipv6_fd < 0) + return -errno; + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->mdns_ipv6_event_source, m->mdns_ipv6_fd, EPOLLIN, on_mdns_packet, m); + if (r < 0) + goto fail; + + return m->mdns_ipv6_fd; + +fail: + m->mdns_ipv6_fd = safe_close(m->mdns_ipv6_fd); + return r; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-mdns.h b/src/grp-resolve/systemd-resolved/resolved-mdns.h new file mode 100644 index 0000000000..5d274648f4 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-mdns.h @@ -0,0 +1,30 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Daniel Mack + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +#define MDNS_PORT 5353 + +int manager_mdns_ipv4_fd(Manager *m); +int manager_mdns_ipv6_fd(Manager *m); + +void manager_mdns_stop(Manager *m); +int manager_mdns_start(Manager *m); diff --git a/src/grp-resolve/systemd-resolved/resolved-resolv-conf.c b/src/grp-resolve/systemd-resolved/resolved-resolv-conf.c new file mode 100644 index 0000000000..5cc79a0040 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-resolv-conf.c @@ -0,0 +1,277 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <resolv.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio-label.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/ordered-set.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-conf.h" +#include "resolved-resolv-conf.h" + +int manager_read_resolv_conf(Manager *m) { + _cleanup_fclose_ FILE *f = NULL; + struct stat st, own; + char line[LINE_MAX]; + usec_t t; + int r; + + assert(m); + + /* Reads the system /etc/resolv.conf, if it exists and is not + * symlinked to our own resolv.conf instance */ + + if (!m->read_resolv_conf) + return 0; + + r = stat("/etc/resolv.conf", &st); + if (r < 0) { + if (errno == ENOENT) + return 0; + + r = log_warning_errno(errno, "Failed to stat /etc/resolv.conf: %m"); + goto clear; + } + + /* Have we already seen the file? */ + t = timespec_load(&st.st_mtim); + if (t == m->resolv_conf_mtime) + return 0; + + /* Is it symlinked to our own file? */ + if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && + st.st_dev == own.st_dev && + st.st_ino == own.st_ino) + return 0; + + f = fopen("/etc/resolv.conf", "re"); + if (!f) { + if (errno == ENOENT) + return 0; + + r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + goto clear; + } + + if (fstat(fileno(f), &st) < 0) { + r = log_error_errno(errno, "Failed to stat open file: %m"); + goto clear; + } + + dns_server_mark_all(m->dns_servers); + dns_search_domain_mark_all(m->search_domains); + + FOREACH_LINE(line, f, r = -errno; goto clear) { + const char *a; + char *l; + + l = strstrip(line); + if (*l == '#' || *l == ';') + continue; + + a = first_word(l, "nameserver"); + if (a) { + r = manager_parse_dns_server_string_and_warn(m, DNS_SERVER_SYSTEM, a); + if (r < 0) + log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a); + + continue; + } + + a = first_word(l, "domain"); + if (!a) /* We treat "domain" lines, and "search" lines as equivalent, and add both to our list. */ + a = first_word(l, "search"); + if (a) { + r = manager_parse_search_domains_and_warn(m, a); + if (r < 0) + log_warning_errno(r, "Failed to parse search domain string '%s', ignoring.", a); + } + } + + m->resolv_conf_mtime = t; + + /* Flush out all servers and search domains that are still + * marked. Those are then ones that didn't appear in the new + * /etc/resolv.conf */ + dns_server_unlink_marked(m->dns_servers); + dns_search_domain_unlink_marked(m->search_domains); + + /* Whenever /etc/resolv.conf changes, start using the first + * DNS server of it. This is useful to deal with broken + * network managing implementations (like NetworkManager), + * that when connecting to a VPN place both the VPN DNS + * servers and the local ones in /etc/resolv.conf. Without + * resetting the DNS server to use back to the first entry we + * will continue to use the local one thus being unable to + * resolve VPN domains. */ + manager_set_dns_server(m, m->dns_servers); + + /* Unconditionally flush the cache when /etc/resolv.conf is + * modified, even if the data it contained was completely + * identical to the previous version we used. We do this + * because altering /etc/resolv.conf is typically done when + * the network configuration changes, and that should be + * enough to flush the global unicast DNS cache. */ + if (m->unicast_scope) + dns_cache_flush(&m->unicast_scope->cache); + + return 0; + +clear: + dns_server_unlink_all(m->dns_servers); + dns_search_domain_unlink_all(m->search_domains); + return r; +} + +static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { + assert(s); + assert(f); + assert(count); + + if (!dns_server_string(s)) { + log_warning("Our of memory, or invalid DNS address. Ignoring server."); + return; + } + + /* Check if the DNS server is limited to particular domains; + * resolv.conf does not have a syntax to express that, so it must not + * appear as a global name server to avoid routing unrelated domains to + * it (which is a privacy violation, will most probably fail anyway, + * and adds unnecessary load) */ + if (dns_server_limited_domains(s)) { + log_debug("DNS server %s has route-only domains, not using as global name server", dns_server_string(s)); + return; + } + + if (*count == MAXNS) + fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); + (*count)++; + + fprintf(f, "nameserver %s\n", dns_server_string(s)); +} + +static void write_resolv_conf_search( + OrderedSet *domains, + FILE *f) { + unsigned length = 0, count = 0; + Iterator i; + char *domain; + + assert(domains); + assert(f); + + fputs("search", f); + + ORDERED_SET_FOREACH(domain, domains, i) { + if (++count > MAXDNSRCH) { + fputs("\n# Too many search domains configured, remaining ones ignored.", f); + break; + } + length += strlen(domain) + 1; + if (length > 256) { + fputs("\n# Total length of all search domains is too long, remaining ones ignored.", f); + break; + } + fputc(' ', f); + fputs(domain, f); + } + + fputs("\n", f); +} + +static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { + Iterator i; + + fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" + "# This is a dynamic resolv.conf file for connecting local clients directly to\n" + "# all known DNS servers.\n#\n" + "# Third party programs must not access this file directly, but only through the\n" + "# symlink at /etc/resolv.conf. To manage resolv.conf(5) in a different way,\n" + "# replace this symlink by a static file or a different symlink.\n#\n" + "# See systemd-resolved.service(8) for details about the supported modes of\n" + "# operation for /etc/resolv.conf.\n\n", f); + + if (ordered_set_isempty(dns)) + fputs("# No DNS servers known.\n", f); + else { + unsigned count = 0; + DnsServer *s; + + ORDERED_SET_FOREACH(s, dns, i) + write_resolv_conf_server(s, f, &count); + } + + if (!ordered_set_isempty(domains)) + write_resolv_conf_search(domains, f); + + return fflush_and_check(f); +} + +int manager_write_resolv_conf(Manager *m) { + + _cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL; + _cleanup_free_ char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(m); + + /* Read the system /etc/resolv.conf first */ + (void) manager_read_resolv_conf(m); + + /* Add the full list to a set, to filter out duplicates */ + r = manager_compile_dns_servers(m, &dns); + if (r < 0) + return log_warning_errno(r, "Failed to compile list of DNS servers: %m"); + + r = manager_compile_search_domains(m, &domains, false); + if (r < 0) + return log_warning_errno(r, "Failed to compile list of search domains: %m"); + + r = fopen_temporary_label(PRIVATE_RESOLV_CONF, PRIVATE_RESOLV_CONF, &f, &temp_path); + if (r < 0) + return log_warning_errno(r, "Failed to open private resolv.conf file for writing: %m"); + + (void) fchmod(fileno(f), 0644); + + r = write_resolv_conf_contents(f, dns, domains); + if (r < 0) { + log_error_errno(r, "Failed to write private resolv.conf contents: %m"); + goto fail; + } + + if (rename(temp_path, PRIVATE_RESOLV_CONF) < 0) { + r = log_error_errno(errno, "Failed to move private resolv.conf file into place: %m"); + goto fail; + } + + return 0; + +fail: + (void) unlink(PRIVATE_RESOLV_CONF); + (void) unlink(temp_path); + + return r; +} diff --git a/src/grp-resolve/systemd-resolved/resolved-resolv-conf.h b/src/grp-resolve/systemd-resolved/resolved-resolv-conf.h new file mode 100644 index 0000000000..75fa080e4c --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-resolv-conf.h @@ -0,0 +1,27 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +#define PRIVATE_RESOLV_CONF "/run/systemd/resolve/resolv.conf" + +int manager_read_resolv_conf(Manager *m); +int manager_write_resolv_conf(Manager *m); diff --git a/src/grp-resolve/systemd-resolved/resolved.c b/src/grp-resolve/systemd-resolved/resolved.c new file mode 100644 index 0000000000..7fe9b7edbb --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved.c @@ -0,0 +1,121 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <systemd/sd-daemon.h> +#include <systemd/sd-event.h> + +#include "systemd-basic/capability-util.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/selinux-util.h" +#include "systemd-basic/signal-util.h" +#include "systemd-basic/user-util.h" + +#include "resolved-conf.h" +#include "resolved-manager.h" +#include "resolved-resolv-conf.h" + +int main(int argc, char *argv[]) { + _cleanup_(manager_freep) Manager *m = NULL; + const char *user = "systemd-resolve"; + uid_t uid; + gid_t gid; + int r; + + log_set_target(LOG_TARGET_AUTO); + log_parse_environment(); + log_open(); + + if (argc != 1) { + log_error("This program takes no arguments."); + r = -EINVAL; + goto finish; + } + + umask(0022); + + r = mac_selinux_init(); + if (r < 0) { + log_error_errno(r, "SELinux setup failed: %m"); + goto finish; + } + + r = get_user_creds(&user, &uid, &gid, NULL, NULL); + if (r < 0) { + log_error_errno(r, "Cannot resolve user name %s: %m", user); + goto finish; + } + + /* Always create the directory where resolv.conf will live */ + r = mkdir_safe_label("/run/systemd/resolve", 0755, uid, gid); + if (r < 0) { + log_error_errno(r, "Could not create runtime directory: %m"); + goto finish; + } + + /* Drop privileges, but keep three caps. Note that we drop those too, later on (see below) */ + r = drop_privileges(uid, gid, + (UINT64_C(1) << CAP_NET_RAW)| /* needed for SO_BINDTODEVICE */ + (UINT64_C(1) << CAP_NET_BIND_SERVICE)| /* needed to bind on port 53 */ + (UINT64_C(1) << CAP_SETPCAP) /* needed in order to drop the caps later */); + if (r < 0) + goto finish; + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGUSR1, SIGUSR2, -1) >= 0); + + r = manager_new(&m); + if (r < 0) { + log_error_errno(r, "Could not create manager: %m"); + goto finish; + } + + r = manager_start(m); + if (r < 0) { + log_error_errno(r, "Failed to start manager: %m"); + goto finish; + } + + /* Write finish default resolv.conf to avoid a dangling symlink */ + (void) manager_write_resolv_conf(m); + + /* Let's drop the remaining caps now */ + r = capability_bounding_set_drop(0, true); + if (r < 0) { + log_error_errno(r, "Failed to drop remaining caps: %m"); + goto finish; + } + + sd_notify(false, + "READY=1\n" + "STATUS=Processing requests..."); + + r = sd_event_loop(m->event); + if (r < 0) { + log_error_errno(r, "Event loop failed: %m"); + goto finish; + } + + sd_event_get_exit_code(m->event, &r); + +finish: + sd_notify(false, + "STOPPING=1\n" + "STATUS=Shutting down..."); + + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} diff --git a/src/grp-resolve/systemd-resolved/resolved.conf.in b/src/grp-resolve/systemd-resolved/resolved.conf.in new file mode 100644 index 0000000000..60afa151e3 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved.conf.in @@ -0,0 +1,21 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. +# +# Entries in this file show the compile time defaults. +# You can change settings by editing this file. +# Defaults can be restored by simply deleting this file. +# +# See resolved.conf(5) for details + +[Resolve] +#DNS= +#FallbackDNS=@DNS_SERVERS@ +#Domains= +#LLMNR=yes +#DNSSEC=@DEFAULT_DNSSEC_MODE@ +#Cache=yes +#DNSStubListener=udp diff --git a/src/grp-resolve/systemd-resolved/resolved.conf.xml b/src/grp-resolve/systemd-resolved/resolved.conf.xml new file mode 100644 index 0000000000..4fc1ef1b33 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved.conf.xml @@ -0,0 +1,242 @@ +<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2014 Tom Gundersen + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="resolved.conf" conditional='ENABLE_RESOLVED' + xmlns:xi="http://www.w3.org/2001/XInclude"> + <refentryinfo> + <title>resolved.conf</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Tom</firstname> + <surname>Gundersen</surname> + <email>teg@jklm.no</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>resolved.conf</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>resolved.conf</refname> + <refname>resolved.conf.d</refname> + <refpurpose>Network Name Resolution configuration files</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/etc/systemd/resolved.conf</filename></para> + <para><filename>/etc/systemd/resolved.conf.d/*.conf</filename></para> + <para><filename>/run/systemd/resolved.conf.d/*.conf</filename></para> + <para><filename>/usr/lib/systemd/resolved.conf.d/*.conf</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>These configuration files control local DNS and LLMNR + name resolution.</para> + + </refsect1> + + <xi:include href="standard-conf.xml" xpointer="main-conf" /> + + <refsect1> + <title>Options</title> + + <para>The following options are available in the <literal>[Resolve]</literal> section:</para> + + <variablelist class='network-directives'> + + <varlistentry> + <term><varname>DNS=</varname></term> + <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as system DNS servers. DNS requests + are sent to one of the listed DNS servers in parallel to suitable per-link DNS servers acquired from + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> or + set at runtime by external applications. For compatibility reasons, if this setting is not specified, the DNS + servers listed in <filename>/etc/resolv.conf</filename> are used instead, if that file exists and any servers + are configured in it. This setting defaults to the empty list.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>FallbackDNS=</varname></term> + <listitem><para>A space-separated list of IPv4 and IPv6 addresses to use as the fallback DNS servers. Any + per-link DNS servers obtained from + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + take precedence over this setting, as do any servers set via <varname>DNS=</varname> above or + <filename>/etc/resolv.conf</filename>. This setting is hence only used if no other DNS server information is + known. If this option is not given, a compiled-in list of DNS servers is used instead.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>Domains=</varname></term> + <listitem><para>A space-separated list of domains. These domains are used as search suffixes when resolving + single-label host names (domain names which contain no dot), in order to qualify them into fully-qualified + domain names (FQDNs). Search domains are strictly processed in the order they are specified, until the name + with the suffix appended is found. For compatibility reasons, if this setting is not specified, the search + domains listed in <filename>/etc/resolv.conf</filename> are used instead, if that file exists and any domains + are configured in it. This setting defaults to the empty list.</para> + + <para>Specified domain names may optionally be prefixed with <literal>~</literal>. In this case they do not + define a search path, but preferably direct DNS queries for the indicated domains to the DNS servers configured + with the system <varname>DNS=</varname> setting (see above), in case additional, suitable per-link DNS servers + are known. If no per-link DNS servers are known using the <literal>~</literal> syntax has no effect. Use the + construct <literal>~.</literal> (which is composed of <literal>~</literal> to indicate a routing domain and + <literal>.</literal> to indicate the DNS root domain that is the implied suffix of all DNS domains) to use the + system DNS server defined with <varname>DNS=</varname> preferably for all domains.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>LLMNR=</varname></term> + <listitem><para>Takes a boolean argument or + <literal>resolve</literal>. Controls Link-Local Multicast Name + Resolution support (<ulink + url="https://tools.ietf.org/html/rfc4795">RFC 4794</ulink>) on + the local host. If true, enables full LLMNR responder and + resolver support. If false, disables both. If set to + <literal>resolve</literal>, only resolution support is enabled, + but responding is disabled. Note that + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + also maintains per-link LLMNR settings. LLMNR will be + enabled on a link only if the per-link and the + global setting is on.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DNSSEC=</varname></term> + <listitem><para>Takes a boolean argument or + <literal>allow-downgrade</literal>. If true all DNS lookups are + DNSSEC-validated locally (excluding LLMNR and Multicast + DNS). If the response to a lookup request is detected to be invalid + a lookup failure is returned to applications. Note that + this mode requires a DNS server that supports DNSSEC. If the + DNS server does not properly support DNSSEC all validations + will fail. If set to <literal>allow-downgrade</literal> DNSSEC + validation is attempted, but if the server does not support + DNSSEC properly, DNSSEC mode is automatically disabled. Note + that this mode makes DNSSEC validation vulnerable to + "downgrade" attacks, where an attacker might be able to + trigger a downgrade to non-DNSSEC mode by synthesizing a DNS + response that suggests DNSSEC was not supported. If set to + false, DNS lookups are not DNSSEC validated.</para> + + <para>Note that DNSSEC validation requires retrieval of + additional DNS data, and thus results in a small DNS look-up + time penalty.</para> + + <para>DNSSEC requires knowledge of "trust anchors" to prove + data integrity. The trust anchor for the Internet root domain + is built into the resolver, additional trust anchors may be + defined with + <citerefentry><refentrytitle>dnssec-trust-anchors.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + Trust anchors may change at regular intervals, and old trust + anchors may be revoked. In such a case DNSSEC validation is + not possible until new trust anchors are configured locally or + the resolver software package is updated with the new root + trust anchor. In effect, when the built-in trust anchor is + revoked and <varname>DNSSEC=</varname> is true, all further + lookups will fail, as it cannot be proved anymore whether + lookups are correctly signed, or validly unsigned. If + <varname>DNSSEC=</varname> is set to + <literal>allow-downgrade</literal> the resolver will + automatically turn off DNSSEC validation in such a case.</para> + + <para>Client programs looking up DNS data will be informed + whether lookups could be verified using DNSSEC, or whether the + returned data could not be verified (either because the data + was found unsigned in the DNS, or the DNS server did not + support DNSSEC or no appropriate trust anchors were known). In + the latter case it is assumed that client programs employ a + secondary scheme to validate the returned DNS data, should + this be required.</para> + + <para>It is recommended to set <varname>DNSSEC=</varname> to + true on systems where it is known that the DNS server supports + DNSSEC correctly, and where software or trust anchor updates + happen regularly. On other systems it is recommended to set + <varname>DNSSEC=</varname> to + <literal>allow-downgrade</literal>.</para> + + <para>In addition to this global DNSSEC setting + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + also maintains per-link DNSSEC settings. For system DNS + servers (see above), only the global DNSSEC setting is in + effect. For per-link DNS servers the per-link + setting is in effect, unless it is unset in which case the + global setting is used instead.</para> + + <para>Site-private DNS zones generally conflict with DNSSEC + operation, unless a negative (if the private zone is not + signed) or positive (if the private zone is signed) trust + anchor is configured for them. If + <literal>allow-downgrade</literal> mode is selected, it is + attempted to detect site-private DNS zones using top-level + domains (TLDs) that are not known by the DNS root server. This + logic does not work in all private zone setups.</para> + + <para>Defaults to off.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>Cache=</varname></term> + <listitem><para>Takes a boolean argument. If "yes" (the default), resolving a domain name which already got + queried earlier will return the previous result as long as it is still valid, and thus does not result in a new + network request. Be aware that turning off caching comes at a performance penalty, which is particularly + high when DNSSEC is used.</para> + + <para>Note that caching is turned off implicitly if the configured DNS server is on a host-local IP address + (such as 127.0.0.1 or ::1), in order to avoid duplicate local caching.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DNSStubListener=</varname></term> + <listitem><para>Takes a boolean argument or one of <literal>udp</literal> and <literal>tcp</literal>. If + <literal>udp</literal> (the default), a DNS stub resolver will listen for UDP requests on address 127.0.0.53 + port 53. If <literal>tcp</literal>, the stub will listen for TCP requests on the same address and port. If + <literal>yes</literal>, the stub listens for both UDP and TCP requests. If <literal>no</literal>, the stub + listener is disabled.</para> + + <para>Note that the DNS stub listener is turned off implicitly when its listening address and port are already + in use.</para></listitem> + </varlistentry> + + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>dnssec-trust-anchors.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>4</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/grp-resolve/systemd-resolved/systemd-resolved.service.m4.in b/src/grp-resolve/systemd-resolved/systemd-resolved.service.m4.in new file mode 100644 index 0000000000..0f0440ddaf --- /dev/null +++ b/src/grp-resolve/systemd-resolved/systemd-resolved.service.m4.in @@ -0,0 +1,40 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. + +[Unit] +Description=Network Name Resolution +Documentation=man:systemd-resolved.service(8) +Documentation=http://www.freedesktop.org/wiki/Software/systemd/resolved +Documentation=http://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers +Documentation=http://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients +After=systemd-networkd.service network.target + +# On kdbus systems we pull in the busname explicitly, because it +# carries policy that allows the daemon to acquire its name. +Wants=org.freedesktop.resolve1.busname +After=org.freedesktop.resolve1.busname + +[Service] +Type=notify +Restart=always +RestartSec=0 +ExecStart=@rootlibexecdir@/systemd-resolved +WatchdogSec=3min +CapabilityBoundingSet=CAP_SETUID CAP_SETGID CAP_SETPCAP CAP_CHOWN CAP_DAC_OVERRIDE CAP_FOWNER CAP_NET_RAW CAP_NET_BIND_SERVICE +PrivateTmp=yes +PrivateDevices=yes +ProtectSystem=full +ProtectHome=yes +ProtectControlGroups=yes +ProtectKernelTunables=yes +MemoryDenyWriteExecute=yes +RestrictRealtime=yes +RestrictAddressFamilies=AF_UNIX AF_NETLINK AF_INET AF_INET6 +SystemCallFilter=~@clock @cpu-emulation @debug @keyring @module @mount @obsolete @raw-io + +[Install] +WantedBy=multi-user.target diff --git a/src/grp-resolve/systemd-resolved/systemd-resolved.service.xml b/src/grp-resolve/systemd-resolved/systemd-resolved.service.xml new file mode 100644 index 0000000000..56f67960ce --- /dev/null +++ b/src/grp-resolve/systemd-resolved/systemd-resolved.service.xml @@ -0,0 +1,234 @@ +<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + +<!-- + This file is part of systemd. + + Copyright 2014 Tom Gundersen + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +--> + +<refentry id="systemd-resolved.service" conditional='ENABLE_RESOLVED'> + + <refentryinfo> + <title>systemd-resolved.service</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Tom</firstname> + <surname>Gundersen</surname> + <email>teg@jklm.no</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-resolved.service</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-resolved.service</refname> + <refname>systemd-resolved</refname> + <refpurpose>Network Name Resolution manager</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>systemd-resolved.service</filename></para> + <para><filename>/usr/lib/systemd/systemd-resolved</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><command>systemd-resolved</command> is a system service that provides network name resolution to local + applications. It implements a caching and validating DNS/DNSSEC stub resolver, as well as an LLMNR resolver and + responder. Local applications may submit network name resolution requests via three interfaces:</para> + + <itemizedlist> + <listitem><para>The native, fully-featured API <command>systemd-resolved</command> exposes on the bus. See the + <ulink url="http://www.freedesktop.org/wiki/Software/systemd/resolved">API Documentation</ulink> for + details. Usage of this API is generally recommended to clients as it is asynchronous and fully featured (for + example, properly returns DNSSEC validation status and interface scope for addresses as necessary for supporting + link-local networking).</para></listitem> + + <listitem><para>The glibc + <citerefentry project='man-pages'><refentrytitle>getaddrinfo</refentrytitle><manvolnum>3</manvolnum></citerefentry> API as defined + by <ulink url="https://tools.ietf.org/html/rfc3493">RFC3493</ulink> and its related resolver functions, + including <citerefentry project='man-pages'><refentrytitle>gethostbyname</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This + API is widely supported, including beyond the Linux platform. In its current form it does not expose DNSSEC + validation status information however, and is synchronous only. This API is backed by the glibc Name Service + Switch (<citerefentry project='man-pages'><refentrytitle>nss</refentrytitle><manvolnum>5</manvolnum></citerefentry>). Usage of the + glibc NSS module <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry> + is required in order to allow glibc's NSS resolver functions to resolve host names via + <command>systemd-resolved</command>.</para></listitem> + + <listitem><para>Additionally, <command>systemd-resolved</command> provides a local DNS stub listener on IP + address 127.0.0.53 on the local loopback interface. Programs issuing DNS requests directly, bypassing any local + API may be directed to this stub, in order to connect them to <command>systemd-resolved</command>. Note however + that it is strongly recommended that local programs use the glibc NSS or bus APIs instead (as described above), + as various network resolution concepts (such as link-local addressing, or LLMNR Unicode domains) cannot be mapped + to the unicast DNS protocol.</para></listitem> + </itemizedlist> + + <para>The DNS servers contacted are determined from the global settings in + <filename>/etc/systemd/resolved.conf</filename>, the per-link static settings in + <filename>/etc/systemd/network/*.network</filename> files, the per-link dynamic settings received over DHCP and any + DNS server information made available by other system services. See + <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> and + <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details + about systemd's own configuration files for DNS servers. To improve compatibility, + <filename>/etc/resolv.conf</filename> is read in order to discover configured system DNS servers, but only if it is + not a symlink to <filename>/run/systemd/resolve/resolv.conf</filename> (see below).</para> + + <para><command>systemd-resolved</command> synthesizes DNS resource records (RRs) for the following cases:</para> + + <itemizedlist> + <listitem><para>The local, configured hostname is resolved to + all locally configured IP addresses ordered by their scope, or + — if none are configured — the IPv4 address 127.0.0.2 (which + is on the local loopback) and the IPv6 address ::1 (which is the + local host).</para></listitem> + + <listitem><para>The hostnames <literal>localhost</literal> and + <literal>localhost.localdomain</literal> (as well as any hostname + ending in <literal>.localhost</literal> or <literal>.localhost.localdomain</literal>) + are resolved to the IP addresses 127.0.0.1 and ::1.</para></listitem> + + <listitem><para>The hostname <literal>gateway</literal> is + resolved to all current default routing gateway addresses, + ordered by their metric. This assigns a stable hostname to the + current gateway, useful for referencing it independently of the + current network configuration state.</para></listitem> + + <listitem><para>The mappings defined in <filename>/etc/hosts</filename> are resolved to their configured + addresses and back.</para></listitem> + </itemizedlist> + + <para>Lookup requests are routed to the available DNS servers + and LLMNR interfaces according to the following rules:</para> + + <itemizedlist> + <listitem><para>Lookups for the special hostname + <literal>localhost</literal> are never routed to the + network. (A few other, special domains are handled the same way.)</para></listitem> + + <listitem><para>Single-label names are routed to all local + interfaces capable of IP multicasting, using the LLMNR + protocol. Lookups for IPv4 addresses are only sent via LLMNR on + IPv4, and lookups for IPv6 addresses are only sent via LLMNR on + IPv6. Lookups for the locally configured host name and the + <literal>gateway</literal> host name are never routed to + LLMNR.</para></listitem> + + <listitem><para>Multi-label names are routed to all local + interfaces that have a DNS sever configured, plus the globally + configured DNS server if there is one. Address lookups from the + link-local address range are never routed to + DNS.</para></listitem> + </itemizedlist> + + <para>If lookups are routed to multiple interfaces, the first + successful response is returned (thus effectively merging the + lookup zones on all matching interfaces). If the lookup failed on + all interfaces, the last failing response is returned.</para> + + <para>Routing of lookups may be influenced by configuring + per-interface domain names. See + <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details. Lookups for a hostname ending in one of the + per-interface domains are exclusively routed to the matching + interfaces.</para> + + <para>See the <ulink url="http://www.freedesktop.org/wiki/Software/systemd/resolved"> resolved D-Bus API + Documentation</ulink> for information about the APIs <filename>systemd-resolved</filename> provides.</para> + + </refsect1> + + <refsect1> + <title><filename>/etc/resolv.conf</filename></title> + + <para>Three modes of handling <filename>/etc/resolv.conf</filename> (see + <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>) are + supported:</para> + + <itemizedlist> + <listitem><para>A static file <filename>/usr/lib/systemd/resolv.conf</filename> is provided that lists + the 127.0.0.53 DNS stub (see above) as only DNS server. This file may be symlinked from + <filename>/etc/resolv.conf</filename> in order to connect all local clients that bypass local DNS APIs to + <command>systemd-resolved</command>. This mode of operation is recommended.</para></listitem> + + <listitem><para><command>systemd-resolved</command> maintains the + <filename>/run/systemd/resolve/resolv.conf</filename> file for compatibility with traditional Linux + programs. This file may be symlinked from <filename>/etc/resolv.conf</filename> and is always kept up-to-date, + containing information about all known DNS servers. Note the file format's limitations: it does not know a + concept of per-interface DNS servers and hence only contains system-wide DNS server definitions. Note that + <filename>/run/systemd/resolve/resolv.conf</filename> should not be used directly by applications, but only + through a symlink from <filename>/etc/resolv.conf</filename>. If this mode of operation is used local clients + that bypass any local DNS API will also bypass <command>systemd-resolved</command> and will talk directly to the + known DNS servers.</para> </listitem> + + <listitem><para>Alternatively, <filename>/etc/resolv.conf</filename> may be managed by other packages, in which + case <command>systemd-resolved</command> will read it for DNS configuration data. In this mode of operation + <command>systemd-resolved</command> is consumer rather than provider of this configuration + file. </para></listitem> + </itemizedlist> + + <para>Note that the selected mode of operation for this file is detected fully automatically, depending on whether + <filename>/etc/resolv.conf</filename> is a symlink to <filename>/run/systemd/resolve/resolv.conf</filename> or + lists 127.0.0.53 as DNS server.</para> + </refsect1> + + <refsect1> + <title>Signals</title> + + <variablelist> + <varlistentry> + <term><constant>SIGUSR1</constant></term> + + <listitem><para>Upon reception of the SIGUSR1 process signal <command>systemd-resolved</command> will dump the + contents of all DNS resource record caches it maintains into the system logs.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>SIGUSR2</constant></term> + + <listitem><para>Upon reception of the SIGUSR2 process signal <command>systemd-resolved</command> will flush all + caches it maintains. Note that it should normally not be necessary to request this explicitly – except for + debugging purposes – as <command>systemd-resolved</command> flushes the caches automatically anyway any time + the host's network configuration changes.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>resolved.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>dnssec-trust-anchors.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>nss-resolve</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-resolve</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>hosts</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> diff --git a/src/grp-resolve/systemd-resolved/systemd-resolved.sysusers b/src/grp-resolve/systemd-resolved/systemd-resolved.sysusers new file mode 100644 index 0000000000..5872bf2db7 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/systemd-resolved.sysusers @@ -0,0 +1,8 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. + +u systemd-resolve - "systemd Resolver" diff --git a/src/grp-resolve/systemd-resolved/systemd-resolved.tmpfiles b/src/grp-resolve/systemd-resolved/systemd-resolved.tmpfiles new file mode 100644 index 0000000000..760fe11412 --- /dev/null +++ b/src/grp-resolve/systemd-resolved/systemd-resolved.tmpfiles @@ -0,0 +1,10 @@ +# This file is part of systemd. +# +# systemd is free software; you can redistribute it and/or modify it +# under the terms of the GNU Lesser General Public License as published by +# the Free Software Foundation; either version 2.1 of the License, or +# (at your option) any later version. + +# See tmpfiles.d(5) for details + +L! /etc/resolv.conf - - - - ../usr/lib/systemd/resolv.conf |