diff options
Diffstat (limited to 'src/grp-resolve/libbasic-dns/src')
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/Makefile | 56 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/dns-type.c | 332 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/resolved-dns-answer.c | 858 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/resolved-dns-dnssec.c | 2199 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/resolved-dns-packet.c | 2300 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/resolved-dns-question.c | 468 | ||||
-rw-r--r-- | src/grp-resolve/libbasic-dns/src/resolved-dns-rr.c | 1839 |
7 files changed, 8052 insertions, 0 deletions
diff --git a/src/grp-resolve/libbasic-dns/src/Makefile b/src/grp-resolve/libbasic-dns/src/Makefile new file mode 100644 index 0000000000..75041cbc3d --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/Makefile @@ -0,0 +1,56 @@ +# -*- 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: $(call at.path,$(srcdir)/../include/basic-dns/dns-type.h) + $(AM_V_GEN)$(SED) -n -r 's/.* DNS_TYPE_(\w+).*/\1/p' <$< >$@ + +$(outdir)/dns_type-to-name.h: $(outdir)/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: $(outdir)/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 }' <$< >$@ + +libbasic_dns_la_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 + +noinst_LTLIBRARIES = libbasic-dns.la +libbasic_dns_la_LIBADD += \ + libsystemd-gcrypt.la \ + libsystemd-shared.la + +$(outdir)/dns-type.lo: $(outdir)/dns_type-from-name.h $(outdir)/dns_type-to-name.h + +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..79603c4dfc --- /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 unsigned int 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..e142832211 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-packet.c @@ -0,0 +1,2300 @@ +/*** + 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; + + 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", +}; +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..35d389b802 --- /dev/null +++ b/src/grp-resolve/libbasic-dns/src/resolved-dns-rr.c @@ -0,0 +1,1839 @@ +/*** + 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) { + free(destination); + return NULL; + } + + 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); + free(rr); + + return NULL; +} + +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); |