diff options
Diffstat (limited to 'src/resolve')
51 files changed, 14361 insertions, 2153 deletions
diff --git a/src/resolve/RFCs b/src/resolve/RFCs new file mode 100644 index 0000000000..22004a00cd --- /dev/null +++ b/src/resolve/RFCs @@ -0,0 +1,59 @@ +Y = Comprehensively Implemented, to the point appropriate for resolved +D = Comprehensively Implemented, by a dependency of resolved +! = Missing and something we might want to implement +~ = Needs no explicit support or doesn't apply +? = Is this relevant today? + = We are working on this + +Y https://tools.ietf.org/html/rfc1034 → DOMAIN NAMES - CONCEPTS AND FACILITIES +Y https://tools.ietf.org/html/rfc1035 → DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION +? https://tools.ietf.org/html/rfc1101 → DNS Encoding of Network Names and Other Types +Y https://tools.ietf.org/html/rfc1123 → Requirements for Internet Hosts -- Application and Support +~ https://tools.ietf.org/html/rfc1464 → Using the Domain Name System To Store Arbitrary String Attributes +Y https://tools.ietf.org/html/rfc1536 → Common DNS Implementation Errors and Suggested Fixes +Y https://tools.ietf.org/html/rfc1876 → A Means for Expressing Location Information in the Domain Name System +Y https://tools.ietf.org/html/rfc2181 → Clarifications to the DNS Specification +Y https://tools.ietf.org/html/rfc2308 → Negative Caching of DNS Queries (DNS NCACHE) +Y https://tools.ietf.org/html/rfc2782 → A DNS RR for specifying the location of services (DNS SRV) +D https://tools.ietf.org/html/rfc3492 → Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA) +Y https://tools.ietf.org/html/rfc3596 → DNS Extensions to Support IP Version 6 +Y https://tools.ietf.org/html/rfc3597 → Handling of Unknown DNS Resource Record (RR) Types +Y https://tools.ietf.org/html/rfc4033 → DNS Security Introduction and Requirements +Y https://tools.ietf.org/html/rfc4034 → Resource Records for the DNS Security Extensions +Y https://tools.ietf.org/html/rfc4035 → Protocol Modifications for the DNS Security Extensions +! https://tools.ietf.org/html/rfc4183 → A Suggested Scheme for DNS Resolution of Networks and Gateways +Y https://tools.ietf.org/html/rfc4255 → Using DNS to Securely Publish Secure Shell (SSH) Key Fingerprints +Y https://tools.ietf.org/html/rfc4343 → Domain Name System (DNS) Case Insensitivity Clarification +~ https://tools.ietf.org/html/rfc4470 → Minimally Covering NSEC Records and DNSSEC On-line Signing +Y https://tools.ietf.org/html/rfc4501 → Domain Name System Uniform Resource Identifiers +Y https://tools.ietf.org/html/rfc4509 → Use of SHA-256 in DNSSEC Delegation Signer (DS) Resource Records (RRs) +~ https://tools.ietf.org/html/rfc4592 → The Role of Wildcards in the Domain Name System +~ https://tools.ietf.org/html/rfc4697 → Observed DNS Resolution Misbehavior +Y https://tools.ietf.org/html/rfc4795 → Link-Local Multicast Name Resolution (LLMNR) +Y https://tools.ietf.org/html/rfc5011 → Automated Updates of DNS Security (DNSSEC) Trust Anchors +Y https://tools.ietf.org/html/rfc5155 → DNS Security (DNSSEC) Hashed Authenticated Denial of Existence +Y https://tools.ietf.org/html/rfc5452 → Measures for Making DNS More Resilient against Forged Answers +Y https://tools.ietf.org/html/rfc5702 → Use of SHA-2 Algorithms with RSA in DNSKEY and RRSIG Resource Records for DNSSEC +Y https://tools.ietf.org/html/rfc5890 → Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework +Y https://tools.ietf.org/html/rfc5891 → Internationalized Domain Names in Applications (IDNA): Protocol +Y https://tools.ietf.org/html/rfc5966 → DNS Transport over TCP - Implementation Requirements +Y https://tools.ietf.org/html/rfc6303 → Locally Served DNS Zones +Y https://tools.ietf.org/html/rfc6604 → xNAME RCODE and Status Bits Clarification +Y https://tools.ietf.org/html/rfc6605 → Elliptic Curve Digital Signature Algorithm (DSA) for DNSSEC + https://tools.ietf.org/html/rfc6672 → DNAME Redirection in the DNS +! https://tools.ietf.org/html/rfc6731 → Improved Recursive DNS Server Selection for Multi-Interfaced Nodes +Y https://tools.ietf.org/html/rfc6761 → Special-Use Domain Names + https://tools.ietf.org/html/rfc6762 → Multicast DNS + https://tools.ietf.org/html/rfc6763 → DNS-Based Service Discovery +~ https://tools.ietf.org/html/rfc6781 → DNSSEC Operational Practices, Version 2 +Y https://tools.ietf.org/html/rfc6840 → Clarifications and Implementation Notes for DNS Security (DNSSEC) +Y https://tools.ietf.org/html/rfc6891 → Extension Mechanisms for DNS (EDNS(0)) +Y https://tools.ietf.org/html/rfc6944 → Applicability Statement: DNS Security (DNSSEC) DNSKEY Algorithm Implementation Status +Y https://tools.ietf.org/html/rfc6975 → Signaling Cryptographic Algorithm Understanding in DNS Security Extensions (DNSSEC) +Y https://tools.ietf.org/html/rfc7129 → Authenticated Denial of Existence in the DNS +Y https://tools.ietf.org/html/rfc7646 → Definition and Use of DNSSEC Negative Trust Anchors +~ https://tools.ietf.org/html/rfc7719 → DNS Terminology + +Also relevant: + + https://www.iab.org/documents/correspondence-reports-documents/2013-2/iab-statement-dotless-domains-considered-harmful/ diff --git a/src/resolve/dns-type.c b/src/resolve/dns-type.c index 63b4b36e88..058d14009a 100644 --- a/src/resolve/dns-type.c +++ b/src/resolve/dns-type.c @@ -20,6 +20,7 @@ ***/ #include "dns-type.h" +#include "string-util.h" typedef const struct { uint16_t type; @@ -44,7 +45,167 @@ int dns_type_from_string(const char *s) { return sc->id; } -/* XXX: find an authoritative list of all pseudo types? */ -bool dns_type_is_pseudo(int n) { - return IN_SET(n, DNS_TYPE_ANY, DNS_TYPE_AXFR, DNS_TYPE_IXFR, DNS_TYPE_OPT); +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_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); +} + +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; } diff --git a/src/resolve/dns-type.h b/src/resolve/dns-type.h index 950af36ee3..78ff71b06e 100644 --- a/src/resolve/dns-type.h +++ b/src/resolve/dns-type.h @@ -23,10 +23,6 @@ #include "macro.h" -const char *dns_type_to_string(int type); -int dns_type_from_string(const char *s); -bool dns_type_is_pseudo(int n); - /* DNS record types, taken from * http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml. */ @@ -119,3 +115,30 @@ enum { assert_cc(DNS_TYPE_SSHFP == 44); assert_cc(DNS_TYPE_TLSA == 52); assert_cc(DNS_TYPE_ANY == 255); + +/* DNS record classes, see RFC 1035 */ +enum { + DNS_CLASS_IN = 0x01, + DNS_CLASS_ANY = 0xFF, + + _DNS_CLASS_MAX, + _DNS_CLASS_INVALID = -1 +}; + +bool dns_type_is_pseudo(uint16_t type); +bool dns_type_is_valid_query(uint16_t type); +bool dns_type_is_valid_rr(uint16_t type); +bool dns_type_may_redirect(uint16_t type); +bool dns_type_is_dnssec(uint16_t type); +bool dns_type_is_obsolete(uint16_t type); +bool dns_type_may_wildcard(uint16_t type); +bool dns_type_apex_only(uint16_t type); + +bool dns_class_is_pseudo(uint16_t class); +bool dns_class_is_valid_rr(uint16_t class); + +const char *dns_type_to_string(int type); +int dns_type_from_string(const char *s); + +const char *dns_class_to_string(uint16_t type); +int dns_class_from_string(const char *name); diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c index 12c17003e9..9110ea52a6 100644 --- a/src/resolve/resolved-bus.c +++ b/src/resolve/resolved-bus.c @@ -19,27 +19,15 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ +#include "alloc-util.h" #include "bus-common-errors.h" #include "bus-util.h" - #include "dns-domain.h" #include "resolved-bus.h" #include "resolved-def.h" +#include "resolved-link-bus.h" static int reply_query_state(DnsQuery *q) { - _cleanup_free_ char *ip = NULL; - const char *name; - int r; - - if (q->request_hostname) - name = q->request_hostname; - else { - r = in_addr_to_string(q->request_family, &q->request_address, &ip); - if (r < 0) - return r; - - name = ip; - } switch (q->state) { @@ -61,11 +49,21 @@ static int reply_query_state(DnsQuery *q) { case DNS_TRANSACTION_ABORTED: return sd_bus_reply_method_errorf(q->request, BUS_ERROR_ABORTED, "Query aborted"); - case DNS_TRANSACTION_FAILURE: { - _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL; + case DNS_TRANSACTION_DNSSEC_FAILED: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_DNSSEC_FAILED, "DNSSEC validation failed: %s", + dnssec_result_to_string(q->answer_dnssec_result)); + + case DNS_TRANSACTION_NO_TRUST_ANCHOR: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_TRUST_ANCHOR, "No suitable trust anchor known"); + + case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED: + return sd_bus_reply_method_errorf(q->request, BUS_ERROR_RR_TYPE_UNSUPPORTED, "Server does not support requested resource record type"); + + case DNS_TRANSACTION_RCODE_FAILURE: { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; if (q->answer_rcode == DNS_RCODE_NXDOMAIN) - sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", name); + sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", dns_query_string(q)); else { const char *rc, *n; char p[3]; /* the rcode is 4 bits long */ @@ -77,7 +75,7 @@ static int reply_query_state(DnsQuery *q) { } n = strjoina(_BUS_ERROR_DNS, rc); - sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", name, rc); + sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", dns_query_string(q), rc); } return sd_bus_reply_method_error(q->request, &error); @@ -85,6 +83,7 @@ static int reply_query_state(DnsQuery *q) { case DNS_TRANSACTION_NULL: case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: case DNS_TRANSACTION_SUCCESS: default: assert_not_reached("Impossible state"); @@ -132,10 +131,9 @@ static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifin } static void bus_method_resolve_hostname_complete(DnsQuery *q) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL, *canonical = NULL; - _cleanup_bus_message_unref_ sd_bus_message *reply = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - unsigned added = 0, i; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + unsigned added = 0; int r; assert(q); @@ -145,6 +143,16 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) { goto finish; } + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + r = sd_bus_message_new_method_return(q->request, &reply); if (r < 0) goto finish; @@ -154,94 +162,46 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) { goto finish; if (q->answer) { - answer = dns_answer_ref(q->answer); - - for (i = 0; i < answer->n_rrs; i++) { - r = dns_question_matches_rr(q->question, answer->items[i].rr); - if (r < 0) - goto finish; - if (r == 0) { - /* Hmm, if this is not an address record, - maybe it's a cname? If so, remember this */ - r = dns_question_matches_cname(q->question, answer->items[i].rr); - if (r < 0) - goto finish; - if (r > 0) - cname = dns_resource_record_ref(answer->items[i].rr); - - continue; - } - - r = append_address(reply, answer->items[i].rr, answer->items[i].ifindex); - if (r < 0) - goto finish; - - if (!canonical) - canonical = dns_resource_record_ref(answer->items[i].rr); - - added ++; - } - } - - if (added == 0) { - if (!cname) { - r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of requested type", q->request_hostname); - goto finish; - } + DnsResourceRecord *rr; + int ifindex; - /* This has a cname? Then update the query with the - * new cname. */ - r = dns_query_cname_redirect(q, cname->cname.name); - if (r < 0) { - if (r == -ELOOP) - r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop on '%s'", q->request_hostname); - else - r = sd_bus_reply_method_errno(q->request, -r, NULL); + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + DnsQuestion *question; - goto finish; - } + question = dns_query_question_for_protocol(q, q->answer_protocol); - /* Before we restart the query, let's see if any of - * the RRs we already got already answers our query */ - for (i = 0; i < answer->n_rrs; i++) { - r = dns_question_matches_rr(q->question, answer->items[i].rr); + r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); if (r < 0) goto finish; if (r == 0) continue; - r = append_address(reply, answer->items[i].rr, answer->items[i].ifindex); + r = append_address(reply, rr, ifindex); if (r < 0) goto finish; if (!canonical) - canonical = dns_resource_record_ref(answer->items[i].rr); + canonical = dns_resource_record_ref(rr); - added++; + added ++; } + } - // what about the cache? - - /* If we didn't find anything, then let's restart the - * query, this time with the cname */ - if (added <= 0) { - r = dns_query_go(q); - if (r < 0) { - r = sd_bus_reply_method_errno(q->request, -r, NULL); - goto finish; - } - - return; - } + if (added <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; } r = sd_bus_message_close_container(reply); if (r < 0) goto finish; - /* Return the precise spelling and uppercasing reported by the server */ + /* Return the precise spelling and uppercasing and CNAME target reported by the server */ assert(canonical); - r = sd_bus_message_append(reply, "st", DNS_RESOURCE_KEY_NAME(canonical->key), SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family)); + r = sd_bus_message_append( + reply, "st", + DNS_RESOURCE_KEY_NAME(canonical->key), + SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); if (r < 0) goto finish; @@ -250,29 +210,29 @@ static void bus_method_resolve_hostname_complete(DnsQuery *q) { finish: if (r < 0) { log_error_errno(r, "Failed to send hostname reply: %m"); - sd_bus_reply_method_errno(q->request, -r, NULL); + sd_bus_reply_method_errno(q->request, r, NULL); } dns_query_free(q); } -static int check_ifindex_flags(int ifindex, uint64_t *flags, sd_bus_error *error) { +static int check_ifindex_flags(int ifindex, uint64_t *flags, uint64_t ok, sd_bus_error *error) { assert(flags); if (ifindex < 0) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index"); - if (*flags & ~SD_RESOLVED_FLAGS_ALL) + if (*flags & ~(SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_CNAME|ok)) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid flags parameter"); - if (*flags == 0) - *flags = SD_RESOLVED_FLAGS_DEFAULT; + if ((*flags & SD_RESOLVED_PROTOCOLS_ALL) == 0) /* If no protocol is enabled, enable all */ + *flags |= SD_RESOLVED_PROTOCOLS_ALL; return 0; } static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata, sd_bus_error *error) { - _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + _cleanup_(dns_question_unrefp) DnsQuestion *question_idna = NULL, *question_utf8 = NULL; Manager *m = userdata; const char *hostname; int family, ifindex; @@ -283,6 +243,8 @@ static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata, assert(message); assert(m); + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "isit", &ifindex, &hostname, &family, &flags); if (r < 0) return r; @@ -290,69 +252,53 @@ static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata, if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); - r = dns_name_normalize(hostname, NULL); + r = dns_name_is_valid(hostname); if (r < 0) + return r; + if (r == 0) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid hostname '%s'", hostname); - r = check_ifindex_flags(ifindex, &flags, error); + r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_SEARCH, error); if (r < 0) return r; - question = dns_question_new(family == AF_UNSPEC ? 2 : 1); - if (!question) - 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, hostname); - if (!key) - return -ENOMEM; - - r = dns_question_add(question, 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, hostname); - if (!key) - return -ENOMEM; + r = dns_question_new_address(&question_utf8, family, hostname, false); + if (r < 0) + return r; - r = dns_question_add(question, key); - if (r < 0) - return r; - } + r = dns_question_new_address(&question_idna, family, hostname, true); + if (r < 0) + return r; - r = dns_query_new(m, &q, question, ifindex, flags); + r = dns_query_new(m, &q, question_utf8, question_idna, ifindex, flags); if (r < 0) return r; q->request = sd_bus_message_ref(message); q->request_family = family; - q->request_hostname = hostname; q->complete = bus_method_resolve_hostname_complete; r = dns_query_bus_track(q, message); if (r < 0) - return r; + goto fail; r = dns_query_go(q); - if (r < 0) { - dns_query_free(q); - return r; - } + if (r < 0) + goto fail; return 1; + +fail: + dns_query_free(q); + return r; } static void bus_method_resolve_address_complete(DnsQuery *q) { - _cleanup_bus_message_unref_ sd_bus_message *reply = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - unsigned added = 0, i; - int r; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + unsigned added = 0; + int ifindex, r; assert(q); @@ -361,6 +307,16 @@ static void bus_method_resolve_address_complete(DnsQuery *q) { goto finish; } + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + r = sd_bus_message_new_method_return(q->request, &reply); if (r < 0) goto finish; @@ -369,30 +325,27 @@ static void bus_method_resolve_address_complete(DnsQuery *q) { if (r < 0) goto finish; - if (q->answer) { - answer = dns_answer_ref(q->answer); + question = dns_query_question_for_protocol(q, q->answer_protocol); - for (i = 0; i < answer->n_rrs; i++) { - r = dns_question_matches_rr(q->question, answer->items[i].rr); - if (r < 0) - goto finish; - if (r == 0) - continue; + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; - r = sd_bus_message_append(reply, "(is)", answer->items[i].ifindex, answer->items[i].rr->ptr.name); - if (r < 0) - goto finish; + r = sd_bus_message_append(reply, "(is)", ifindex, rr->ptr.name); + if (r < 0) + goto finish; - added ++; - } + added ++; } - if (added == 0) { + if (added <= 0) { _cleanup_free_ char *ip = NULL; in_addr_to_string(q->request_family, &q->request_address, &ip); - - r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address '%s' does not have any RR of requested type", ip); + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address '%s' does not have any RR of requested type", strna(ip)); goto finish; } @@ -400,7 +353,7 @@ static void bus_method_resolve_address_complete(DnsQuery *q) { if (r < 0) goto finish; - r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family)); + r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); if (r < 0) goto finish; @@ -409,16 +362,14 @@ static void bus_method_resolve_address_complete(DnsQuery *q) { finish: if (r < 0) { log_error_errno(r, "Failed to send address reply: %m"); - sd_bus_reply_method_errno(q->request, -r, NULL); + sd_bus_reply_method_errno(q->request, r, NULL); } dns_query_free(q); } static int bus_method_resolve_address(sd_bus_message *message, void *userdata, sd_bus_error *error) { - _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; - _cleanup_free_ char *reverse = NULL; Manager *m = userdata; int family, ifindex; uint64_t flags; @@ -430,6 +381,8 @@ static int bus_method_resolve_address(sd_bus_message *message, void *userdata, s assert(message); assert(m); + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "ii", &ifindex, &family); if (r < 0) return r; @@ -448,29 +401,15 @@ static int bus_method_resolve_address(sd_bus_message *message, void *userdata, s if (r < 0) return r; - r = check_ifindex_flags(ifindex, &flags, error); - if (r < 0) - return r; - - r = dns_name_reverse(family, d, &reverse); + r = check_ifindex_flags(ifindex, &flags, 0, error); if (r < 0) return r; - question = dns_question_new(1); - if (!question) - return -ENOMEM; - - key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse); - if (!key) - return -ENOMEM; - - reverse = NULL; - - r = dns_question_add(question, key); + r = dns_question_new_reverse(&question, family, d); if (r < 0) return r; - r = dns_query_new(m, &q, question, ifindex, flags); + r = dns_query_new(m, &q, question, question, ifindex, flags|SD_RESOLVED_NO_SEARCH); if (r < 0) return r; @@ -481,21 +420,53 @@ static int bus_method_resolve_address(sd_bus_message *message, void *userdata, s r = dns_query_bus_track(q, message); if (r < 0) - return r; + goto fail; r = dns_query_go(q); - if (r < 0) { - dns_query_free(q); - return r; - } + if (r < 0) + goto fail; return 1; + +fail: + dns_query_free(q); + return r; +} + +static int bus_message_append_rr(sd_bus_message *m, DnsResourceRecord *rr, int ifindex) { + int r; + + assert(m); + assert(rr); + + r = sd_bus_message_open_container(m, 'r', "iqqay"); + if (r < 0) + return r; + + r = sd_bus_message_append(m, "iqq", + ifindex, + rr->key->class, + rr->key->type); + if (r < 0) + return r; + + r = dns_resource_record_to_wire_format(rr, false); + if (r < 0) + return r; + + r = sd_bus_message_append_array(m, 'y', rr->wire_format, rr->wire_format_size); + if (r < 0) + return r; + + return sd_bus_message_close_container(m); } static void bus_method_resolve_record_complete(DnsQuery *q) { - _cleanup_bus_message_unref_ sd_bus_message *reply = NULL; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - unsigned added = 0, i; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + DnsResourceRecord *rr; + DnsQuestion *question; + unsigned added = 0; + int ifindex; int r; assert(q); @@ -505,6 +476,16 @@ static void bus_method_resolve_record_complete(DnsQuery *q) { goto finish; } + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + r = sd_bus_message_new_method_return(q->request, &reply); if (r < 0) goto finish; @@ -513,54 +494,24 @@ static void bus_method_resolve_record_complete(DnsQuery *q) { if (r < 0) goto finish; - if (q->answer) { - answer = dns_answer_ref(q->answer); - - for (i = 0; i < answer->n_rrs; i++) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - size_t start; - - r = dns_question_matches_rr(q->question, answer->items[i].rr); - if (r < 0) - goto finish; - if (r == 0) - continue; - - r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0); - if (r < 0) - goto finish; - - p->refuse_compression = true; - - r = dns_packet_append_rr(p, answer->items[i].rr, &start); - if (r < 0) - goto finish; - - r = sd_bus_message_open_container(reply, 'r', "iqqay"); - if (r < 0) - goto finish; - - r = sd_bus_message_append(reply, "iqq", - answer->items[i].ifindex, - answer->items[i].rr->key->class, - answer->items[i].rr->key->type); - if (r < 0) - goto finish; + question = dns_query_question_for_protocol(q, q->answer_protocol); - r = sd_bus_message_append_array(reply, 'y', DNS_PACKET_DATA(p) + start, p->size - start); - if (r < 0) - goto finish; + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; - r = sd_bus_message_close_container(reply); - if (r < 0) - goto finish; + r = bus_message_append_rr(reply, rr, ifindex); + if (r < 0) + goto finish; - added ++; - } + added ++; } if (added <= 0) { - r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", q->request_hostname); + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", dns_query_string(q)); goto finish; } @@ -568,7 +519,7 @@ static void bus_method_resolve_record_complete(DnsQuery *q) { if (r < 0) goto finish; - r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family)); + r = sd_bus_message_append(reply, "t", SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); if (r < 0) goto finish; @@ -577,7 +528,7 @@ static void bus_method_resolve_record_complete(DnsQuery *q) { finish: if (r < 0) { log_error_errno(r, "Failed to send record reply: %m"); - sd_bus_reply_method_errno(q->request, -r, NULL); + sd_bus_reply_method_errno(q->request, r, NULL); } dns_query_free(q); @@ -596,15 +547,24 @@ static int bus_method_resolve_record(sd_bus_message *message, void *userdata, sd assert(message); assert(m); + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "isqqt", &ifindex, &name, &class, &type, &flags); if (r < 0) return r; - r = dns_name_normalize(name, NULL); + r = dns_name_is_valid(name); if (r < 0) + return r; + if (r == 0) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid name '%s'", name); - r = check_ifindex_flags(ifindex, &flags, error); + if (!dns_type_is_valid_query(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Specified resource record type %" PRIu16 " may not be used in a query.", type); + if (dns_type_is_obsolete(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Specified DNS resource record type %" PRIu16 " is obsolete.", type); + + r = check_ifindex_flags(ifindex, &flags, 0, error); if (r < 0) return r; @@ -620,32 +580,892 @@ static int bus_method_resolve_record(sd_bus_message *message, void *userdata, sd if (r < 0) return r; - r = dns_query_new(m, &q, question, ifindex, flags); + r = dns_query_new(m, &q, question, question, ifindex, flags|SD_RESOLVED_NO_SEARCH); if (r < 0) return r; q->request = sd_bus_message_ref(message); - q->request_hostname = name; q->complete = bus_method_resolve_record_complete; r = dns_query_bus_track(q, message); if (r < 0) - return r; + goto fail; r = dns_query_go(q); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(q); + return r; +} + +static int append_srv(DnsQuery *q, sd_bus_message *reply, DnsResourceRecord *rr) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + DnsQuery *aux; + int r; + + assert(q); + assert(reply); + assert(rr); + assert(rr->key); + + if (rr->key->type != DNS_TYPE_SRV) + return 0; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + /* First, let's see if we could find an appropriate A or AAAA + * record for the SRV record */ + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + DnsResourceRecord *zz; + DnsQuestion *question; + + if (aux->state != DNS_TRANSACTION_SUCCESS) + continue; + if (aux->auxiliary_result != 0) + continue; + + question = dns_query_question_for_protocol(aux, aux->answer_protocol); + + r = dns_name_equal(dns_question_first_name(question), rr->srv.name); + if (r < 0) + return r; + if (r == 0) + continue; + + DNS_ANSWER_FOREACH(zz, aux->answer) { + + r = dns_question_matches_rr(question, zz, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + canonical = dns_resource_record_ref(zz); + break; + } + + if (canonical) + break; + } + + /* Is there are successful A/AAAA lookup for this SRV RR? If not, don't add it */ + if (!canonical) + return 0; + } + + r = sd_bus_message_open_container(reply, 'r', "qqqsa(iiay)s"); + if (r < 0) + return r; + + r = sd_bus_message_append( + reply, + "qqqs", + rr->srv.priority, rr->srv.weight, rr->srv.port, rr->srv.name); + if (r < 0) + return r; + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + return r; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + DnsResourceRecord *zz; + DnsQuestion *question; + int ifindex; + + if (aux->state != DNS_TRANSACTION_SUCCESS) + continue; + if (aux->auxiliary_result != 0) + continue; + + question = dns_query_question_for_protocol(aux, aux->answer_protocol); + + r = dns_name_equal(dns_question_first_name(question), rr->srv.name); + if (r < 0) + return r; + if (r == 0) + continue; + + DNS_ANSWER_FOREACH_IFINDEX(zz, ifindex, aux->answer) { + + r = dns_question_matches_rr(question, zz, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + r = append_address(reply, zz, ifindex); + if (r < 0) + return r; + } + } + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + /* Note that above we appended the hostname as encoded in the + * SRV, and here the canonical hostname this maps to. */ + r = sd_bus_message_append(reply, "s", canonical ? DNS_RESOURCE_KEY_NAME(canonical->key) : rr->srv.name); + if (r < 0) + return r; + + r = sd_bus_message_close_container(reply); + if (r < 0) + return r; + + return 1; +} + +static int append_txt(sd_bus_message *reply, DnsResourceRecord *rr) { + DnsTxtItem *i; + int r; + + assert(reply); + assert(rr); + assert(rr->key); + + if (rr->key->type != DNS_TYPE_TXT) + return 0; + + LIST_FOREACH(items, i, rr->txt.items) { + + if (i->length <= 0) + continue; + + r = sd_bus_message_append_array(reply, 'y', i->data, i->length); + if (r < 0) + return r; + } + + return 1; +} + +static void resolve_service_all_complete(DnsQuery *q) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL; + _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; + _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + unsigned added = 0; + DnsQuery *aux; + int r; + + assert(q); + + if (q->block_all_complete > 0) + return; + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + DnsQuery *bad = NULL; + bool have_success = false; + + LIST_FOREACH(auxiliary_queries, aux, q->auxiliary_queries) { + + switch (aux->state) { + + case DNS_TRANSACTION_PENDING: + /* If an auxiliary query is still pending, let's wait */ + return; + + case DNS_TRANSACTION_SUCCESS: + if (aux->auxiliary_result == 0) + have_success = true; + else + bad = aux; + break; + + default: + bad = aux; + break; + } + } + + if (!have_success) { + /* We can only return one error, hence pick the last error we encountered */ + + assert(bad); + + if (bad->state == DNS_TRANSACTION_SUCCESS) { + assert(bad->auxiliary_result != 0); + + if (bad->auxiliary_result == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(bad)); + goto finish; + } + + r = bad->auxiliary_result; + goto finish; + } + + r = reply_query_state(bad); + goto finish; + } + } + + r = sd_bus_message_new_method_return(q->request, &reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "(qqqsa(iiay)s)"); + if (r < 0) + goto finish; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = append_srv(q, reply, rr); + if (r < 0) + goto finish; + if (r == 0) /* not an SRV record */ + continue; + + if (!canonical) + canonical = dns_resource_record_ref(rr); + + added++; + } + + if (added <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + r = sd_bus_message_open_container(reply, 'a', "ay"); + if (r < 0) + goto finish; + + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + r = append_txt(reply, rr); + if (r < 0) + goto finish; + } + + r = sd_bus_message_close_container(reply); + if (r < 0) + goto finish; + + assert(canonical); + r = dns_service_split(DNS_RESOURCE_KEY_NAME(canonical->key), &name, &type, &domain); + if (r < 0) + goto finish; + + r = sd_bus_message_append( + reply, + "ssst", + name, type, domain, + SD_RESOLVED_FLAGS_MAKE(q->answer_protocol, q->answer_family, q->answer_authenticated)); + if (r < 0) + goto finish; + + r = sd_bus_send(q->manager->bus, reply, NULL); + +finish: if (r < 0) { - dns_query_free(q); + log_error_errno(r, "Failed to send service reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); + } + + dns_query_free(q); +} + +static void resolve_service_hostname_complete(DnsQuery *q) { + int r; + + assert(q); + assert(q->auxiliary_for); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + resolve_service_all_complete(q->auxiliary_for); + return; + } + + r = dns_query_process_cname(q); + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + /* This auxiliary lookup is finished or failed, let's see if all are finished now. */ + q->auxiliary_result = r; + resolve_service_all_complete(q->auxiliary_for); +} + +static int resolve_service_hostname(DnsQuery *q, DnsResourceRecord *rr, int ifindex) { + _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL; + DnsQuery *aux; + int r; + + assert(q); + assert(rr); + assert(rr->key); + assert(rr->key->type == DNS_TYPE_SRV); + + /* OK, we found an SRV record for the service. Let's resolve + * the hostname included in it */ + + r = dns_question_new_address(&question, q->request_family, rr->srv.name, false); + if (r < 0) return r; + + r = dns_query_new(q->manager, &aux, question, question, ifindex, q->flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + aux->request_family = q->request_family; + aux->complete = resolve_service_hostname_complete; + + r = dns_query_make_auxiliary(aux, q); + if (r == -EAGAIN) { + /* Too many auxiliary lookups? If so, don't complain, + * let's just not add this one, we already have more + * than enough */ + + dns_query_free(aux); + return 0; + } + if (r < 0) + goto fail; + + /* Note that auxiliary queries do not track the original bus + * client, only the primary request does that. */ + + r = dns_query_go(aux); + if (r < 0) + goto fail; + + return 1; + +fail: + dns_query_free(aux); + return r; +} + +static void bus_method_resolve_service_complete(DnsQuery *q) { + bool has_root_domain = false; + DnsResourceRecord *rr; + DnsQuestion *question; + unsigned found = 0; + int ifindex, r; + + assert(q); + + if (q->state != DNS_TRANSACTION_SUCCESS) { + r = reply_query_state(q); + goto finish; + } + + r = dns_query_process_cname(q); + if (r == -ELOOP) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop detected, or CNAME resolving disabled on '%s'", dns_query_string(q)); + goto finish; + } + if (r < 0) + goto finish; + if (r == DNS_QUERY_RESTARTED) /* This was a cname, and the query was restarted. */ + return; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, q->answer) { + r = dns_question_matches_rr(question, rr, NULL); + if (r < 0) + goto finish; + if (r == 0) + continue; + + if (rr->key->type != DNS_TYPE_SRV) + continue; + + if (dns_name_is_root(rr->srv.name)) { + has_root_domain = true; + continue; + } + + if ((q->flags & SD_RESOLVED_NO_ADDRESS) == 0) { + q->block_all_complete ++; + r = resolve_service_hostname(q, rr, ifindex); + q->block_all_complete --; + + if (r < 0) + goto finish; + } + + found++; + } + + if (has_root_domain && found <= 0) { + /* If there's exactly one SRV RR and it uses + * the root domain as host name, then the + * service is explicitly not offered on the + * domain. Report this as a recognizable + * error. See RFC 2782, Section "Usage + * Rules". */ + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_SERVICE, "'%s' does not provide the requested service", dns_query_string(q)); + goto finish; + } + + if (found <= 0) { + r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of the requested type", dns_query_string(q)); + goto finish; + } + + /* Maybe we are already finished? check now... */ + resolve_service_all_complete(q); + return; + +finish: + if (r < 0) { + log_error_errno(r, "Failed to send service reply: %m"); + sd_bus_reply_method_errno(q->request, r, NULL); } + dns_query_free(q); +} + +static int bus_method_resolve_service(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_(dns_question_unrefp) DnsQuestion *question_idna = NULL, *question_utf8 = NULL; + const char *name, *type, *domain; + _cleanup_free_ char *n = NULL; + Manager *m = userdata; + int family, ifindex; + uint64_t flags; + DnsQuery *q; + int r; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_read(message, "isssit", &ifindex, &name, &type, &domain, &family, &flags); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + if (isempty(name)) + name = NULL; + else if (!dns_service_name_is_valid(name)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid service name '%s'", name); + + if (isempty(type)) + type = NULL; + else if (!dns_srv_type_is_valid(type)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid SRV service type '%s'", type); + + r = dns_name_is_valid(domain); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid domain '%s'", domain); + + if (name && !type) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Service name cannot be specified without service type."); + + r = check_ifindex_flags(ifindex, &flags, SD_RESOLVED_NO_TXT|SD_RESOLVED_NO_ADDRESS, error); + if (r < 0) + return r; + + r = dns_question_new_service(&question_utf8, name, type, domain, !(flags & SD_RESOLVED_NO_TXT), false); + if (r < 0) + return r; + + r = dns_question_new_service(&question_idna, name, type, domain, !(flags & SD_RESOLVED_NO_TXT), true); + if (r < 0) + return r; + + r = dns_query_new(m, &q, question_utf8, question_idna, ifindex, flags|SD_RESOLVED_NO_SEARCH); + if (r < 0) + return r; + + q->request = sd_bus_message_ref(message); + q->request_family = family; + q->complete = bus_method_resolve_service_complete; + + r = dns_query_bus_track(q, message); + if (r < 0) + goto fail; + + r = dns_query_go(q); + if (r < 0) + goto fail; + return 1; + +fail: + dns_query_free(q); + return r; +} + +int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex) { + int r; + + assert(reply); + assert(s); + + r = sd_bus_message_open_container(reply, 'r', with_ifindex ? "iiay" : "iay"); + if (r < 0) + return r; + + if (with_ifindex) { + r = sd_bus_message_append(reply, "i", s->link ? s->link->ifindex : 0); + if (r < 0) + return r; + } + + r = sd_bus_message_append(reply, "i", s->family); + if (r < 0) + return r; + + r = sd_bus_message_append_array(reply, 'y', &s->address, FAMILY_ADDRESS_SIZE(s->family)); + if (r < 0) + return r; + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_dns_servers( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + unsigned c = 0; + DnsServer *s; + Iterator i; + Link *l; + int r; + + assert(reply); + assert(m); + + r = sd_bus_message_open_container(reply, 'a', "(iiay)"); + if (r < 0) + return r; + + LIST_FOREACH(servers, s, m->dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + + c++; + } + + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(servers, s, l->dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + c++; + } + } + + if (c == 0) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = bus_dns_server_append(reply, s, true); + if (r < 0) + return r; + } + } + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_search_domains( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + DnsSearchDomain *d; + Iterator i; + Link *l; + int r; + + assert(reply); + assert(m); + + r = sd_bus_message_open_container(reply, 'a', "(is)"); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, m->search_domains) { + r = sd_bus_message_append(reply, "(is)", 0, d->name); + if (r < 0) + return r; + } + + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(domains, d, l->search_domains) { + r = sd_bus_message_append(reply, "is", l->ifindex, d->name); + if (r < 0) + return r; + } + } + + return sd_bus_message_close_container(reply); +} + +static int bus_property_get_transaction_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "(tt)", + (uint64_t) hashmap_size(m->dns_transactions), + (uint64_t) m->n_transactions_total); +} + +static int bus_property_get_cache_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + uint64_t size = 0, hit = 0, miss = 0; + Manager *m = userdata; + DnsScope *s; + + assert(reply); + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) { + size += dns_cache_size(&s->cache); + hit += s->cache.n_hit; + miss += s->cache.n_miss; + } + + return sd_bus_message_append(reply, "(ttt)", size, hit, miss); +} + +static int bus_property_get_dnssec_statistics( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "(tttt)", + (uint64_t) m->n_dnssec_secure, + (uint64_t) m->n_dnssec_insecure, + (uint64_t) m->n_dnssec_bogus, + (uint64_t) m->n_dnssec_indeterminate); +} + +static int bus_property_get_dnssec_supported( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Manager *m = userdata; + + assert(reply); + assert(m); + + return sd_bus_message_append(reply, "b", manager_dnssec_supported(m)); +} + +static int bus_method_reset_statistics(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Manager *m = userdata; + DnsScope *s; + + assert(message); + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) + s->cache.n_hit = s->cache.n_miss = 0; + + m->n_transactions_total = 0; + m->n_dnssec_secure = m->n_dnssec_insecure = m->n_dnssec_bogus = m->n_dnssec_indeterminate = 0; + + return sd_bus_reply_method_return(message, NULL); +} + +static int get_any_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) { + Link *l; + + assert(m); + assert(ret); + + if (ifindex <= 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index"); + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) + return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_LINK, "Link %i not known", ifindex); + + *ret = l; + return 0; +} + +static int get_unmanaged_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) { + Link *l; + int r; + + assert(m); + assert(ret); + + r = get_any_link(m, ifindex, &l, error); + if (r < 0) + return r; + + if (l->flags & IFF_LOOPBACK) + return sd_bus_error_setf(error, BUS_ERROR_LINK_BUSY, "Link %s is loopback device.", l->name); + if (l->is_managed) + return sd_bus_error_setf(error, BUS_ERROR_LINK_BUSY, "Link %s is managed.", l->name); + + *ret = l; + return 0; +} + +static int call_link_method(Manager *m, sd_bus_message *message, sd_bus_message_handler_t handler, sd_bus_error *error) { + int ifindex, r; + Link *l; + + assert(m); + assert(message); + assert(handler); + + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "i", &ifindex); + if (r < 0) + return r; + + r = get_unmanaged_link(m, ifindex, &l, error); + if (r < 0) + return r; + + return handler(message, l, error); +} + +static int bus_method_set_link_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dns_servers, error); +} + +static int bus_method_set_link_search_domains(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_search_domains, error); +} + +static int bus_method_set_link_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_llmnr, error); +} + +static int bus_method_set_link_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_mdns, error); +} + +static int bus_method_set_link_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dnssec, error); +} + +static int bus_method_set_link_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_set_dnssec_negative_trust_anchors, error); +} + +static int bus_method_revert_link(sd_bus_message *message, void *userdata, sd_bus_error *error) { + return call_link_method(userdata, message, bus_link_method_revert, error); +} + +static int bus_method_get_link(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_free_ char *p = NULL; + Manager *m = userdata; + int r, ifindex; + Link *l; + + assert(message); + assert(m); + + assert_cc(sizeof(int) == sizeof(int32_t)); + r = sd_bus_message_read(message, "i", &ifindex); + if (r < 0) + return r; + + r = get_any_link(m, ifindex, &l, error); + if (r < 0) + return r; + + p = link_bus_path(l); + if (!p) + return -ENOMEM; + + return sd_bus_reply_method_return(message, "o", p); } static const sd_bus_vtable resolve_vtable[] = { SD_BUS_VTABLE_START(0), + SD_BUS_PROPERTY("LLMNRHostname", "s", NULL, offsetof(Manager, llmnr_hostname), 0), + SD_BUS_PROPERTY("DNS", "a(iiay)", bus_property_get_dns_servers, 0, 0), + SD_BUS_PROPERTY("Domains", "a(is)", bus_property_get_search_domains, 0, 0), + SD_BUS_PROPERTY("TransactionStatistics", "(tt)", bus_property_get_transaction_statistics, 0, 0), + SD_BUS_PROPERTY("CacheStatistics", "(ttt)", bus_property_get_cache_statistics, 0, 0), + SD_BUS_PROPERTY("DNSSECStatistics", "(tttt)", bus_property_get_dnssec_statistics, 0, 0), + SD_BUS_PROPERTY("DNSSECSupported", "b", bus_property_get_dnssec_supported, 0, 0), + SD_BUS_METHOD("ResolveHostname", "isit", "a(iiay)st", bus_method_resolve_hostname, SD_BUS_VTABLE_UNPRIVILEGED), SD_BUS_METHOD("ResolveAddress", "iiayt", "a(is)t", bus_method_resolve_address, SD_BUS_VTABLE_UNPRIVILEGED), SD_BUS_METHOD("ResolveRecord", "isqqt", "a(iqqay)t", bus_method_resolve_record, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResolveService", "isssit", "a(qqqsa(iiay)s)aayssst", bus_method_resolve_service, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("ResetStatistics", NULL, NULL, bus_method_reset_statistics, 0), + SD_BUS_METHOD("GetLink", "i", "o", bus_method_get_link, SD_BUS_VTABLE_UNPRIVILEGED), + SD_BUS_METHOD("SetLinkDNS", "ia(iay)", NULL, bus_method_set_link_dns_servers, 0), + SD_BUS_METHOD("SetLinkDomains", "ias", NULL, bus_method_set_link_search_domains, 0), + SD_BUS_METHOD("SetLinkLLMNR", "is", NULL, bus_method_set_link_llmnr, 0), + SD_BUS_METHOD("SetLinkMulticastDNS", "is", NULL, bus_method_set_link_mdns, 0), + SD_BUS_METHOD("SetLinkDNSSEC", "is", NULL, bus_method_set_link_dnssec, 0), + SD_BUS_METHOD("SetLinkDNSSECNegativeTrustAnchors", "ias", NULL, bus_method_set_link_dnssec_negative_trust_anchors, 0), + SD_BUS_METHOD("RevertLink", "i", NULL, bus_method_revert_link, 0), + SD_BUS_VTABLE_END, }; @@ -703,6 +1523,7 @@ int manager_connect_bus(Manager *m) { if (r < 0) return log_error_errno(r, "Failed to install bus reconnect time event: %m"); + (void) sd_event_source_set_description(m->bus_retry_event_source, "bus-retry"); return 0; } @@ -710,6 +1531,14 @@ int manager_connect_bus(Manager *m) { if (r < 0) return log_error_errno(r, "Failed to register object: %m"); + r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/resolve1/link", "org.freedesktop.resolve1.Link", link_vtable, link_object_find, m); + if (r < 0) + return log_error_errno(r, "Failed to register link objects: %m"); + + r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/resolve1/link", link_node_enumerator, m); + if (r < 0) + return log_error_errno(r, "Failed to register link enumerator: %m"); + r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0); if (r < 0) return log_error_errno(r, "Failed to register name: %m"); diff --git a/src/resolve/resolved-bus.h b/src/resolve/resolved-bus.h index 1e72891178..1ee57ba43d 100644 --- a/src/resolve/resolved-bus.h +++ b/src/resolve/resolved-bus.h @@ -24,3 +24,4 @@ #include "resolved-manager.h" int manager_connect_bus(Manager *m); +int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex); diff --git a/src/resolve/resolved-conf.c b/src/resolve/resolved-conf.c index 7af63b0a82..88df7534c4 100644 --- a/src/resolve/resolved-conf.c +++ b/src/resolve/resolved-conf.c @@ -19,56 +19,107 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ +#include "alloc-util.h" #include "conf-parser.h" - +#include "def.h" +#include "extract-word.h" +#include "parse-util.h" #include "resolved-conf.h" +#include "string-util.h" + +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word) { + union in_addr_union address; + int family, r; + DnsServer *s; + + assert(m); + assert(word); + + r = in_addr_from_string_auto(word, &family, &address); + if (r < 0) + return r; + + /* Filter out duplicates */ + s = dns_server_find(manager_get_first_dns_server(m, type), family, &address); + if (s) { + /* + * Drop the marker. This is used to find the servers + * that ceased to exist, see + * manager_mark_dns_servers() and + * manager_flush_marked_dns_servers(). + */ + dns_server_move_back_and_unmark(s); + return 0; + } + + return dns_server_new(m, NULL, type, NULL, family, &address); +} -int manager_parse_dns_server(Manager *m, DnsServerType type, const char *string) { - const char *word, *state; - size_t length; - DnsServer *first; +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string) { int r; assert(m); assert(string); - first = type == DNS_SERVER_FALLBACK ? m->fallback_dns_servers : m->dns_servers; + for(;;) { + _cleanup_free_ char *word = NULL; - FOREACH_WORD_QUOTED(word, length, string, state) { - char buffer[length+1]; - int family; - union in_addr_union addr; - bool found = false; - DnsServer *s; + r = extract_first_word(&string, &word, NULL, 0); + if (r < 0) + return r; + if (r == 0) + break; - memcpy(buffer, word, length); - buffer[length] = 0; + r = manager_add_dns_server_by_string(m, type, word); + if (r < 0) + log_warning_errno(r, "Failed to add DNS server address '%s', ignoring.", word); + } - r = in_addr_from_string_auto(buffer, &family, &addr); - if (r < 0) { - log_warning("Ignoring invalid DNS address '%s'", buffer); - continue; - } + return 0; +} + +int manager_add_search_domain_by_string(Manager *m, const char *domain) { + DnsSearchDomain *d; + int r; + + assert(m); + assert(domain); + + r = dns_search_domain_find(m->search_domains, domain, &d); + if (r < 0) + return r; + if (r > 0) { + dns_search_domain_move_back_and_unmark(d); + return 0; + } + + return dns_search_domain_new(m, NULL, DNS_SEARCH_DOMAIN_SYSTEM, NULL, domain); +} + +int manager_parse_search_domains_and_warn(Manager *m, const char *string) { + int r; - /* Filter out duplicates */ - LIST_FOREACH(servers, s, first) - if (s->family == family && in_addr_equal(family, &s->address, &addr)) { - found = true; - break; - } + assert(m); + assert(string); - if (found) - continue; + for(;;) { + _cleanup_free_ char *word = NULL; - r = dns_server_new(m, NULL, type, NULL, family, &addr); + r = extract_first_word(&string, &word, NULL, EXTRACT_QUOTES); if (r < 0) return r; + if (r == 0) + break; + + r = manager_add_search_domain_by_string(m, word); + if (r < 0) + log_warning_errno(r, "Failed to add search domain '%s', ignoring.", word); } return 0; } -int config_parse_dnsv( +int config_parse_dns_servers( const char *unit, const char *filename, unsigned line, @@ -90,12 +141,12 @@ int config_parse_dnsv( if (isempty(rvalue)) /* Empty assignment means clear the list */ - manager_flush_dns_servers(m, ltype); + dns_server_unlink_all(manager_get_first_dns_server(m, ltype)); else { - /* Otherwise add to the list */ - r = manager_parse_dns_server(m, ltype, rvalue); + /* Otherwise, add to the list */ + r = manager_parse_dns_server_string_and_warn(m, ltype, rvalue); if (r < 0) { - log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue); + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue); return 0; } } @@ -104,11 +155,13 @@ int config_parse_dnsv( * /etc/resolv.conf */ if (ltype == DNS_SERVER_SYSTEM) m->read_resolv_conf = false; + if (ltype == DNS_SERVER_FALLBACK) + m->need_builtin_fallbacks = false; return 0; } -int config_parse_support( +int config_parse_search_domains( const char *unit, const char *filename, unsigned line, @@ -120,34 +173,52 @@ int config_parse_support( void *data, void *userdata) { - Support support, *v = data; + Manager *m = userdata; int r; assert(filename); assert(lvalue); assert(rvalue); + assert(m); - support = support_from_string(rvalue); - if (support < 0) { - r = parse_boolean(rvalue); + if (isempty(rvalue)) + /* Empty assignment means clear the list */ + dns_search_domain_unlink_all(m->search_domains); + else { + /* Otherwise, add to the list */ + r = manager_parse_search_domains_and_warn(m, rvalue); if (r < 0) { - log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse support level '%s'. Ignoring.", rvalue); + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse search domains string '%s'. Ignoring.", rvalue); return 0; } - - support = r ? SUPPORT_YES : SUPPORT_NO; } - *v = support; + /* If we have a manual setting, then we stop reading + * /etc/resolv.conf */ + m->read_resolv_conf = false; + return 0; } int manager_parse_config_file(Manager *m) { + int r; + assert(m); - return config_parse_many("/etc/systemd/resolved.conf", - CONF_DIRS_NULSTR("systemd/resolved.conf"), - "Resolve\0", - config_item_perf_lookup, resolved_gperf_lookup, - false, m); + r = config_parse_many(PKGSYSCONFDIR "/resolved.conf", + CONF_PATHS_NULSTR("systemd/resolved.conf.d"), + "Resolve\0", + config_item_perf_lookup, resolved_gperf_lookup, + false, m); + if (r < 0) + return r; + + if (m->need_builtin_fallbacks) { + r = manager_parse_dns_server_string_and_warn(m, DNS_SERVER_FALLBACK, DNS_SERVERS); + if (r < 0) + return r; + } + + return 0; + } diff --git a/src/resolve/resolved-conf.h b/src/resolve/resolved-conf.h index b3dbea7b6b..b4ef1b0378 100644 --- a/src/resolve/resolved-conf.h +++ b/src/resolve/resolved-conf.h @@ -23,10 +23,16 @@ #include "resolved-manager.h" -int manager_parse_dns_server(Manager *m, DnsServerType type, const char *string); int manager_parse_config_file(Manager *m); +int manager_add_search_domain_by_string(Manager *m, const char *domain); +int manager_parse_search_domains_and_warn(Manager *m, const char *string); + +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word); +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string); + const struct ConfigPerfItem* resolved_gperf_lookup(const char *key, unsigned length); -int config_parse_dnsv(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); -int config_parse_support(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_dns_servers(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_search_domains(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_dnssec(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); diff --git a/src/resolve/resolved-def.h b/src/resolve/resolved-def.h index 086d111205..6014d345f3 100644 --- a/src/resolve/resolved-def.h +++ b/src/resolve/resolved-def.h @@ -21,10 +21,18 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#define SD_RESOLVED_DNS ((uint64_t) 1) -#define SD_RESOLVED_LLMNR_IPV4 ((uint64_t) 2) -#define SD_RESOLVED_LLMNR_IPV6 ((uint64_t) 4) +#define SD_RESOLVED_DNS (UINT64_C(1) << 0) +#define SD_RESOLVED_LLMNR_IPV4 (UINT64_C(1) << 1) +#define SD_RESOLVED_LLMNR_IPV6 (UINT64_C(1) << 2) +#define SD_RESOLVED_MDNS_IPV4 (UINT64_C(1) << 3) +#define SD_RESOLVED_MDNS_IPV6 (UINT64_C(1) << 4) +#define SD_RESOLVED_NO_CNAME (UINT64_C(1) << 5) +#define SD_RESOLVED_NO_TXT (UINT64_C(1) << 6) +#define SD_RESOLVED_NO_ADDRESS (UINT64_C(1) << 7) +#define SD_RESOLVED_NO_SEARCH (UINT64_C(1) << 8) +#define SD_RESOLVED_AUTHENTICATED (UINT64_C(1) << 9) + #define SD_RESOLVED_LLMNR (SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_LLMNR_IPV6) +#define SD_RESOLVED_MDNS (SD_RESOLVED_MDNS_IPV4|SD_RESOLVED_MDNS_IPV6) -#define SD_RESOLVED_FLAGS_ALL (SD_RESOLVED_DNS|SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_LLMNR_IPV6) -#define SD_RESOLVED_FLAGS_DEFAULT SD_RESOLVED_FLAGS_ALL +#define SD_RESOLVED_PROTOCOLS_ALL (SD_RESOLVED_MDNS|SD_RESOLVED_LLMNR|SD_RESOLVED_DNS) diff --git a/src/resolve/resolved-dns-answer.c b/src/resolve/resolved-dns-answer.c index 13ad4ca6bd..f74e440531 100644 --- a/src/resolve/resolved-dns-answer.c +++ b/src/resolve/resolved-dns-answer.c @@ -19,8 +19,11 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "resolved-dns-answer.h" +#include "alloc-util.h" #include "dns-domain.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-dnssec.h" +#include "string-util.h" DnsAnswer *dns_answer_new(unsigned n) { DnsAnswer *a; @@ -44,6 +47,18 @@ DnsAnswer *dns_answer_ref(DnsAnswer *a) { 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; @@ -51,11 +66,7 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) { assert(a->n_ref > 0); if (a->n_ref == 1) { - unsigned i; - - for (i = 0; i < a->n_rrs; i++) - dns_resource_record_unref(a->items[i].rr); - + dns_answer_flush(a); free(a); } else a->n_ref--; @@ -63,7 +74,39 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) { return NULL; } -int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { +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; @@ -71,6 +114,8 @@ int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { 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) @@ -80,27 +125,66 @@ int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { if (r < 0) return r; if (r > 0) { - /* Entry already exists, keep the entry with - * the higher RR, or the one with TTL 0 */ + /* Don't mix contradicting TTLs (see below) */ + if ((rr->ttl == 0) != (a->items[i].rr->ttl == 0)) + return -EINVAL; - if (rr->ttl == 0 || (rr->ttl > a->items[i].rr->ttl && a->items[i].rr->ttl != 0)) { + /* 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; + } } - if (a->n_rrs >= a->n_allocated) - return -ENOSPC; + return dns_answer_add_raw(a, rr, ifindex, flags); +} - a->items[a->n_rrs].rr = dns_resource_record_ref(rr); - a->items[a->n_rrs].ifindex = ifindex; - a->n_rrs++; +static int dns_answer_add_all(DnsAnswer *a, DnsAnswer *b) { + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int ifindex, r; - return 1; + 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) { @@ -126,52 +210,204 @@ int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl) { soa->soa.expire = 1; soa->soa.minimum = ttl; - return dns_answer_add(a, soa, 0); + return dns_answer_add(a, soa, 0, DNS_ANSWER_AUTHENTICATED); } -int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { - unsigned i; +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); - if (!a) - return 0; + 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; - for (i = 0; i < a->n_rrs; i++) { - r = dns_resource_key_match_rr(key, a->items[i].rr); + 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) + if (r == 0) + continue; + + if (!ret_flags) return 1; + + if (found) + flags &= i_flags; + else { + flags = i_flags; + found = true; + } } - return 0; + if (ret_flags) + *ret_flags = flags; + + return found; } -int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) { - unsigned i; +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); - assert(ret); - if (!a) - return 0; + 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; - for (i = 0; i < a->n_rrs; i++) { + 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 (a->items[i].rr->key->class != DNS_CLASS_IN) - continue; + 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; + } - if (a->items[i].rr->key->type != DNS_TYPE_SOA) - 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); - if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->items[i].rr->key))) { - *ret = a->items[i].rr; + /* 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; } } @@ -179,41 +415,271 @@ int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **r return 0; } -DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) { - _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL; - DnsAnswer *k; +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; - if (a && (!b || b->n_rrs <= 0)) - return dns_answer_ref(a); - if ((!a || a->n_rrs <= 0) && b) - return dns_answer_ref(b); + assert(a); + assert(key); - ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0)); - if (!ret) - return NULL; + /* 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; - if (a) { - for (i = 0; i < a->n_rrs; i++) { - r = dns_answer_add(ret, a->items[i].rr, a->items[i].ifindex); + r = dns_answer_add_raw(copy, rr, ifindex, flags); if (r < 0) - return NULL; + return r; } + + dns_answer_unref(*a); + *a = copy; + copy = NULL; + + return 1; } - if (b) { - for (i = 0; i < b->n_rrs; i++) { - r = dns_answer_add(ret, b->items[i].rr, b->items[i].ifindex); + /* 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 NULL; + return r; } + + dns_answer_unref(*a); + *a = copy; + copy = NULL; + + return 1; } - k = ret; - ret = NULL; + /* Only a single reference, edit in-place */ - return k; + 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) { @@ -252,6 +718,8 @@ void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) { int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { DnsAnswer *n; + assert(a); + if (n_free <= 0) return 0; @@ -266,6 +734,9 @@ int dns_answer_reserve(DnsAnswer **a, unsigned 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; @@ -280,3 +751,110 @@ int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { *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 + * possibly, 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/resolve/resolved-dns-answer.h b/src/resolve/resolved-dns-answer.h index 0757dd60d0..1875fd6136 100644 --- a/src/resolve/resolved-dns-answer.h +++ b/src/resolve/resolved-dns-answer.h @@ -24,16 +24,26 @@ typedef struct DnsAnswer DnsAnswer; typedef struct DnsAnswerItem DnsAnswerItem; +#include "macro.h" #include "resolved-dns-rr.h" /* A simple array of resource records. We keep track of the * originating ifindex for each RR where that makes sense, so that we * can qualify A and AAAA RRs referring to a local link with the - * right ifindex. */ + * right ifindex. + * + * Note that we usually encode the the empty DnsAnswer object as a simple NULL. */ + +typedef enum DnsAnswerFlags { + DNS_ANSWER_AUTHENTICATED = 1, /* Item has been authenticated */ + DNS_ANSWER_CACHEABLE = 2, /* Item is subject to caching */ + DNS_ANSWER_SHARED_OWNER = 4, /* For mDNS: RRset may be owner by multiple peers */ +} DnsAnswerFlags; struct DnsAnswerItem { DnsResourceRecord *rr; int ifindex; + DnsAnswerFlags flags; }; struct DnsAnswer { @@ -46,14 +56,90 @@ DnsAnswer *dns_answer_new(unsigned n); DnsAnswer *dns_answer_ref(DnsAnswer *a); DnsAnswer *dns_answer_unref(DnsAnswer *a); -int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex); +int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags); +int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags); int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl); -int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key); -int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret); -DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b); +int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags); +int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *combined_flags); +int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags); +int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a); +int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone); + +int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags); +int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags); + +int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret); +int dns_answer_extend(DnsAnswer **a, DnsAnswer *b); + void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local); int dns_answer_reserve(DnsAnswer **a, unsigned n_free); +int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free); + +int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key); +int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rr); + +int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags); +int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags); + +bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname); + +static inline unsigned dns_answer_size(DnsAnswer *a) { + return a ? a->n_rrs : 0; +} + +void dns_answer_dump(DnsAnswer *answer, FILE *f); DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref); + +#define _DNS_ANSWER_FOREACH(q, kk, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, (kk) = (UNIQ_T(i, q) < (a)->n_rrs ? (a)->items[UNIQ_T(i, q)].rr : NULL)) + +#define DNS_ANSWER_FOREACH(kk, a) _DNS_ANSWER_FOREACH(UNIQ, kk, a) + +#define _DNS_ANSWER_FOREACH_IFINDEX(q, kk, ifi, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0)) + +#define DNS_ANSWER_FOREACH_IFINDEX(kk, ifindex, a) _DNS_ANSWER_FOREACH_IFINDEX(UNIQ, kk, ifindex, a) + +#define _DNS_ANSWER_FOREACH_FLAGS(q, kk, fl, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0)) + +#define DNS_ANSWER_FOREACH_FLAGS(kk, flags, a) _DNS_ANSWER_FOREACH_FLAGS(UNIQ, kk, flags, a) + +#define _DNS_ANSWER_FOREACH_FULL(q, kk, ifi, fl, a) \ + for (unsigned UNIQ_T(i, q) = ({ \ + (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \ + (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \ + (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \ + 0; \ + }); \ + (a) && (UNIQ_T(i, q) < (a)->n_rrs); \ + UNIQ_T(i, q)++, \ + (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \ + (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0), \ + (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0)) + +#define DNS_ANSWER_FOREACH_FULL(kk, ifindex, flags, a) _DNS_ANSWER_FOREACH_FULL(UNIQ, kk, ifindex, flags, a) diff --git a/src/resolve/resolved-dns-cache.c b/src/resolve/resolved-dns-cache.c index cbbbed8c8a..fdb34d11df 100644 --- a/src/resolve/resolved-dns-cache.c +++ b/src/resolve/resolved-dns-cache.c @@ -19,14 +19,19 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ +#include "alloc-util.h" +#include "dns-domain.h" +#include "resolved-dns-answer.h" #include "resolved-dns-cache.h" #include "resolved-dns-packet.h" +#include "string-util.h" -/* Never cache more than 1K entries */ -#define CACHE_MAX 1024 +/* Never cache more than 4K entries. RFC 1536, Section 5 suggests to + * leave DNS caches unbounded, but that's crazy. */ +#define CACHE_MAX 4096 -/* We never keep any item longer than 10min in our cache */ -#define CACHE_TTL_MAX_USEC (10 * USEC_PER_MINUTE) +/* We never keep any item longer than 2h in our cache */ +#define CACHE_TTL_MAX_USEC (2 * USEC_PER_HOUR) typedef enum DnsCacheItemType DnsCacheItemType; typedef struct DnsCacheItem DnsCacheItem; @@ -38,13 +43,18 @@ enum DnsCacheItemType { }; struct DnsCacheItem { + DnsCacheItemType type; DnsResourceKey *key; DnsResourceRecord *rr; + usec_t until; - DnsCacheItemType type; - unsigned prioq_idx; + bool authenticated:1; + bool shared_owner:1; + int owner_family; union in_addr_union owner_address; + + unsigned prioq_idx; LIST_FIELDS(DnsCacheItem, by_key); }; @@ -59,7 +69,7 @@ static void dns_cache_item_free(DnsCacheItem *i) { DEFINE_TRIVIAL_CLEANUP_FUNC(DnsCacheItem*, dns_cache_item_free); -static void dns_cache_item_remove_and_free(DnsCache *c, DnsCacheItem *i) { +static void dns_cache_item_unlink_and_free(DnsCache *c, DnsCacheItem *i) { DnsCacheItem *first; assert(c); @@ -80,34 +90,55 @@ static void dns_cache_item_remove_and_free(DnsCache *c, DnsCacheItem *i) { dns_cache_item_free(i); } -void dns_cache_flush(DnsCache *c) { - DnsCacheItem *i; +static bool dns_cache_remove_by_rr(DnsCache *c, DnsResourceRecord *rr) { + DnsCacheItem *first, *i; + int r; + + first = hashmap_get(c->by_key, rr->key); + LIST_FOREACH(by_key, i, first) { + r = dns_resource_record_equal(i->rr, rr); + if (r < 0) + return r; + if (r > 0) { + dns_cache_item_unlink_and_free(c, i); + return true; + } + } + + return false; +} + +static bool dns_cache_remove_by_key(DnsCache *c, DnsResourceKey *key) { + DnsCacheItem *first, *i, *n; assert(c); + assert(key); - while ((i = hashmap_first(c->by_key))) - dns_cache_item_remove_and_free(c, i); + first = hashmap_remove(c->by_key, key); + if (!first) + return false; - assert(hashmap_size(c->by_key) == 0); - assert(prioq_size(c->by_expiry) == 0); + LIST_FOREACH_SAFE(by_key, i, n, first) { + prioq_remove(c->by_expiry, i, &i->prioq_idx); + dns_cache_item_free(i); + } - c->by_key = hashmap_free(c->by_key); - c->by_expiry = prioq_free(c->by_expiry); + return true; } -static bool dns_cache_remove(DnsCache *c, DnsResourceKey *key) { - DnsCacheItem *i; - bool exist = false; +void dns_cache_flush(DnsCache *c) { + DnsResourceKey *key; assert(c); - assert(key); - while ((i = hashmap_get(c->by_key, key))) { - dns_cache_item_remove_and_free(c, i); - exist = true; - } + while ((key = hashmap_first_key(c->by_key))) + dns_cache_remove_by_key(c, key); - return exist; + assert(hashmap_size(c->by_key) == 0); + assert(prioq_size(c->by_expiry) == 0); + + c->by_key = hashmap_free(c->by_key); + c->by_expiry = prioq_free(c->by_expiry); } static void dns_cache_make_space(DnsCache *c, unsigned add) { @@ -137,7 +168,7 @@ static void dns_cache_make_space(DnsCache *c, unsigned add) { /* Take an extra reference to the key so that it * doesn't go away in the middle of the remove call */ key = dns_resource_key_ref(i->key); - dns_cache_remove(c, key); + dns_cache_remove_by_key(c, key); } } @@ -149,7 +180,6 @@ void dns_cache_prune(DnsCache *c) { /* Remove all entries that are past their TTL */ for (;;) { - _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; DnsCacheItem *i; i = prioq_peek(c->by_expiry); @@ -162,10 +192,19 @@ void dns_cache_prune(DnsCache *c) { if (i->until > t) break; - /* Take an extra reference to the key so that it - * doesn't go away in the middle of the remove call */ - key = dns_resource_key_ref(i->key); - dns_cache_remove(c, key); + /* Depending whether this is an mDNS shared entry + * either remove only this one RR or the whole + * RRset */ + if (i->shared_owner) + dns_cache_item_unlink_and_free(c, i); + else { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + /* Take an extra reference to the key so that it + * doesn't go away in the middle of the remove call */ + key = dns_resource_key_ref(i->key); + dns_cache_remove_by_key(c, key); + } } } @@ -208,6 +247,19 @@ static int dns_cache_link_item(DnsCache *c, DnsCacheItem *i) { first = hashmap_get(c->by_key, i->key); if (first) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; + + /* Keep a reference to the original key, while we manipulate the list. */ + k = dns_resource_key_ref(first->key); + + /* Now, try to reduce the number of keys we keep */ + dns_resource_key_reduce(&first->key, &i->key); + + if (first->rr) + dns_resource_key_reduce(&first->rr->key, &i->key); + if (i->rr) + dns_resource_key_reduce(&i->rr->key, &i->key); + LIST_PREPEND(by_key, first, i); assert_se(hashmap_replace(c->by_key, first->key, first) >= 0); } else { @@ -234,10 +286,56 @@ static DnsCacheItem* dns_cache_get(DnsCache *c, DnsResourceRecord *rr) { return NULL; } -static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsResourceRecord *rr, usec_t timestamp) { +static usec_t calculate_until(DnsResourceRecord *rr, uint32_t nsec_ttl, usec_t timestamp, bool use_soa_minimum) { + uint32_t ttl; + usec_t u; + + assert(rr); + + ttl = MIN(rr->ttl, nsec_ttl); + if (rr->key->type == DNS_TYPE_SOA && use_soa_minimum) { + /* If this is a SOA RR, and it is requested, clamp to + * the SOA's minimum field. This is used when we do + * negative caching, to determine the TTL for the + * negative caching entry. See RFC 2308, Section + * 5. */ + + if (ttl > rr->soa.minimum) + ttl = rr->soa.minimum; + } + + u = ttl * USEC_PER_SEC; + if (u > CACHE_TTL_MAX_USEC) + u = CACHE_TTL_MAX_USEC; + + if (rr->expiry != USEC_INFINITY) { + usec_t left; + + /* Make use of the DNSSEC RRSIG expiry info, if we + * have it */ + + left = LESS_BY(rr->expiry, now(CLOCK_REALTIME)); + if (u > left) + u = left; + } + + return timestamp + u; +} + +static void dns_cache_item_update_positive( + DnsCache *c, + DnsCacheItem *i, + DnsResourceRecord *rr, + bool authenticated, + bool shared_owner, + usec_t timestamp, + int owner_family, + const union in_addr_union *owner_address) { + assert(c); assert(i); assert(rr); + assert(owner_address); i->type = DNS_CACHE_POSITIVE; @@ -254,7 +352,12 @@ static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsReso dns_resource_key_unref(i->key); i->key = dns_resource_key_ref(rr->key); - i->until = timestamp + MIN(rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); + i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); + i->authenticated = authenticated; + i->shared_owner = shared_owner; + + i->owner_family = owner_family; + i->owner_address = *owner_address; prioq_reshuffle(c->by_expiry, i, &i->prioq_idx); } @@ -262,6 +365,8 @@ static void dns_cache_item_update_positive(DnsCache *c, DnsCacheItem *i, DnsReso static int dns_cache_put_positive( DnsCache *c, DnsResourceRecord *rr, + bool authenticated, + bool shared_owner, usec_t timestamp, int owner_family, const union in_addr_union *owner_address) { @@ -269,34 +374,48 @@ static int dns_cache_put_positive( _cleanup_(dns_cache_item_freep) DnsCacheItem *i = NULL; _cleanup_free_ char *key_str = NULL; DnsCacheItem *existing; - int r; + int r, k; assert(c); assert(rr); assert(owner_address); - /* New TTL is 0? Delete the entry... */ + /* Never cache pseudo RRs */ + if (dns_class_is_pseudo(rr->key->class)) + return 0; + if (dns_type_is_pseudo(rr->key->type)) + return 0; + + /* New TTL is 0? Delete this specific entry... */ if (rr->ttl <= 0) { - if (dns_cache_remove(c, rr->key)) { + k = dns_cache_remove_by_rr(c, rr); + + if (log_get_max_level() >= LOG_DEBUG) { r = dns_resource_key_to_string(rr->key, &key_str); if (r < 0) return r; - log_debug("Removed zero TTL entry from cache: %s", key_str); + if (k > 0) + log_debug("Removed zero TTL entry from cache: %s", key_str); + else + log_debug("Not caching zero TTL cache entry: %s", key_str); } return 0; } - if (rr->key->class == DNS_CLASS_ANY) - return 0; - if (rr->key->type == DNS_TYPE_ANY) - return 0; - - /* Entry exists already? Update TTL and timestamp */ + /* Entry exists already? Update TTL, timestamp and owner*/ existing = dns_cache_get(c, rr); if (existing) { - dns_cache_item_update_positive(c, existing, rr, timestamp); + dns_cache_item_update_positive( + c, + existing, + rr, + authenticated, + shared_owner, + timestamp, + owner_family, + owner_address); return 0; } @@ -314,20 +433,24 @@ static int dns_cache_put_positive( i->type = DNS_CACHE_POSITIVE; i->key = dns_resource_key_ref(rr->key); i->rr = dns_resource_record_ref(rr); - i->until = timestamp + MIN(i->rr->ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); - i->prioq_idx = PRIOQ_IDX_NULL; + i->until = calculate_until(rr, (uint32_t) -1, timestamp, false); + i->authenticated = authenticated; + i->shared_owner = shared_owner; i->owner_family = owner_family; i->owner_address = *owner_address; + i->prioq_idx = PRIOQ_IDX_NULL; r = dns_cache_link_item(c, i); if (r < 0) return r; - r = dns_resource_key_to_string(i->key, &key_str); - if (r < 0) - return r; + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(i->key, &key_str); + if (r < 0) + return r; - log_debug("Added cache entry for %s", key_str); + log_debug("Added positive cache entry for %s", key_str); + } i = NULL; return 0; @@ -337,8 +460,10 @@ static int dns_cache_put_negative( DnsCache *c, DnsResourceKey *key, int rcode, + bool authenticated, + uint32_t nsec_ttl, usec_t timestamp, - uint32_t soa_ttl, + DnsResourceRecord *soa, int owner_family, const union in_addr_union *owner_address) { @@ -348,20 +473,25 @@ static int dns_cache_put_negative( assert(c); assert(key); + assert(soa); assert(owner_address); - dns_cache_remove(c, key); - - if (key->class == DNS_CLASS_ANY) + /* Never cache pseudo RR keys. DNS_TYPE_ANY is particularly + * important to filter out as we use this as a pseudo-type for + * NXDOMAIN entries */ + if (dns_class_is_pseudo(key->class)) return 0; - if (key->type == DNS_TYPE_ANY) + if (dns_type_is_pseudo(key->type)) return 0; - if (soa_ttl <= 0) { - r = dns_resource_key_to_string(key, &key_str); - if (r < 0) - return r; - log_debug("Ignored negative cache entry with zero SOA TTL: %s", key_str); + if (nsec_ttl <= 0 || soa->soa.minimum <= 0 || soa->ttl <= 0) { + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("Not caching negative entry with zero SOA/NSEC/NSEC3 TTL: %s", key_str); + } return 0; } @@ -380,65 +510,119 @@ static int dns_cache_put_negative( return -ENOMEM; i->type = rcode == DNS_RCODE_SUCCESS ? DNS_CACHE_NODATA : DNS_CACHE_NXDOMAIN; - i->key = dns_resource_key_ref(key); - i->until = timestamp + MIN(soa_ttl * USEC_PER_SEC, CACHE_TTL_MAX_USEC); - i->prioq_idx = PRIOQ_IDX_NULL; + i->until = calculate_until(soa, nsec_ttl, timestamp, true); + i->authenticated = authenticated; i->owner_family = owner_family; i->owner_address = *owner_address; + i->prioq_idx = PRIOQ_IDX_NULL; + + if (i->type == DNS_CACHE_NXDOMAIN) { + /* NXDOMAIN entries should apply equally to all types, so we use ANY as + * a pseudo type for this purpose here. */ + i->key = dns_resource_key_new(key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(key)); + if (!i->key) + return -ENOMEM; + + /* Make sure to remove any previous entry for this + * specific ANY key. (For non-ANY keys the cache data + * is already cleared by the caller.) Note that we + * don't bother removing positive or NODATA cache + * items in this case, because it would either be slow + * or require explicit indexing by name */ + dns_cache_remove_by_key(c, key); + } else + i->key = dns_resource_key_ref(key); r = dns_cache_link_item(c, i); if (r < 0) return r; - r = dns_resource_key_to_string(i->key, &key_str); - if (r < 0) - return r; + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(i->key, &key_str); + if (r < 0) + return r; - log_debug("Added %s cache entry for %s", i->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", key_str); + log_debug("Added %s cache entry for %s", i->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", key_str); + } i = NULL; return 0; } +static void dns_cache_remove_previous( + DnsCache *c, + DnsResourceKey *key, + DnsAnswer *answer) { + + DnsResourceRecord *rr; + DnsAnswerFlags flags; + + assert(c); + + /* First, if we were passed a key (i.e. on LLMNR/DNS, but + * not on mDNS), delete all matching old RRs, so that we only + * keep complete by_key in place. */ + if (key) + dns_cache_remove_by_key(c, key); + + /* Second, flush all entries matching the answer, unless this + * is an RR that is explicitly marked to be "shared" between + * peers (i.e. mDNS RRs without the flush-cache bit set). */ + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; + + if (flags & DNS_ANSWER_SHARED_OWNER) + continue; + + dns_cache_remove_by_key(c, rr->key); + } +} + int dns_cache_put( DnsCache *c, - DnsQuestion *q, + DnsResourceKey *key, int rcode, DnsAnswer *answer, - unsigned max_rrs, + bool authenticated, + uint32_t nsec_ttl, usec_t timestamp, int owner_family, const union in_addr_union *owner_address) { - unsigned cache_keys, i; + DnsResourceRecord *soa = NULL, *rr; + DnsAnswerFlags flags; + unsigned cache_keys; int r; assert(c); + assert(owner_address); - if (q) { - /* First, if we were passed a question, delete all matching old RRs, - * so that we only keep complete by_key in place. */ - for (i = 0; i < q->n_keys; i++) - dns_cache_remove(c, q->keys[i]); - } + dns_cache_remove_previous(c, key, answer); - if (!answer) - return 0; + if (dns_answer_size(answer) <= 0) { + if (log_get_max_level() >= LOG_DEBUG) { + _cleanup_free_ char *key_str = NULL; + + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("Not caching negative entry without a SOA record: %s", key_str); + } - for (i = 0; i < answer->n_rrs; i++) - dns_cache_remove(c, answer->items[i].rr->key); + return 0; + } /* We only care for positive replies and NXDOMAINs, on all * other replies we will simply flush the respective entries, * and that's it */ - if (!IN_SET(rcode, DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN)) return 0; - cache_keys = answer->n_rrs; - - if (q) - cache_keys += q->n_keys; + cache_keys = dns_answer_size(answer); + if (key) + cache_keys ++; /* Make some space for our new entries */ dns_cache_make_space(c, cache_keys); @@ -447,39 +631,65 @@ int dns_cache_put( timestamp = now(clock_boottime_or_monotonic()); /* Second, add in positive entries for all contained RRs */ - for (i = 0; i < MIN(max_rrs, answer->n_rrs); i++) { - r = dns_cache_put_positive(c, answer->items[i].rr, timestamp, owner_family, owner_address); + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; + + r = dns_cache_put_positive( + c, + rr, + flags & DNS_ANSWER_AUTHENTICATED, + flags & DNS_ANSWER_SHARED_OWNER, + timestamp, + owner_family, owner_address); if (r < 0) goto fail; } - if (!q) + if (!key) /* mDNS doesn't know negative caching, really */ return 0; - /* Third, add in negative entries for all keys with no RR */ - for (i = 0; i < q->n_keys; i++) { - DnsResourceRecord *soa = NULL; + /* Third, add in negative entries if the key has no RR */ + r = dns_answer_match_key(answer, key, NULL); + if (r < 0) + goto fail; + if (r > 0) + return 0; - r = dns_answer_contains(answer, q->keys[i]); - if (r < 0) - goto fail; - if (r > 0) - continue; + /* But not if it has a matching CNAME/DNAME (the negative + * caching will be done on the canonical name, not on the + * alias) */ + r = dns_answer_find_cname_or_dname(answer, key, NULL, NULL); + if (r < 0) + goto fail; + if (r > 0) + return 0; - /* See https://tools.ietf.org/html/rfc2308, which - * say that a matching SOA record in the packet - * is used to to enable negative caching. */ + /* See https://tools.ietf.org/html/rfc2308, which say that a + * matching SOA record in the packet is used to to enable + * negative caching. */ + r = dns_answer_find_soa(answer, key, &soa, &flags); + if (r < 0) + goto fail; + if (r == 0) + return 0; - r = dns_answer_find_soa(answer, q->keys[i], &soa); - if (r < 0) - goto fail; - if (r == 0) - continue; + /* Refuse using the SOA data if it is unsigned, but the key is + * signed */ + if (authenticated && (flags & DNS_ANSWER_AUTHENTICATED) == 0) + return 0; - r = dns_cache_put_negative(c, q->keys[i], rcode, timestamp, MIN(soa->soa.minimum, soa->ttl), owner_family, owner_address); - if (r < 0) - goto fail; - } + r = dns_cache_put_negative( + c, + key, + rcode, + authenticated, + nsec_ttl, + timestamp, + soa, + owner_family, owner_address); + if (r < 0) + goto fail; return 0; @@ -487,55 +697,123 @@ fail: /* Adding all RRs failed. Let's clean up what we already * added, just in case */ - if (q) { - for (i = 0; i < q->n_keys; i++) - dns_cache_remove(c, q->keys[i]); - } + if (key) + dns_cache_remove_by_key(c, key); + + DNS_ANSWER_FOREACH_FLAGS(rr, flags, answer) { + if ((flags & DNS_ANSWER_CACHEABLE) == 0) + continue; - for (i = 0; i < answer->n_rrs; i++) - dns_cache_remove(c, answer->items[i].rr->key); + dns_cache_remove_by_key(c, rr->key); + } return r; } -int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **ret) { +static DnsCacheItem *dns_cache_get_by_key_follow_cname_dname_nsec(DnsCache *c, DnsResourceKey *k) { + DnsCacheItem *i; + const char *n; + int r; + + assert(c); + assert(k); + + /* If we hit some OOM error, or suchlike, we don't care too + * much, after all this is just a cache */ + + i = hashmap_get(c->by_key, k); + if (i) + return i; + + n = DNS_RESOURCE_KEY_NAME(k); + + /* Check if we have an NXDOMAIN cache item for the name, notice that we use + * the pseudo-type ANY for NXDOMAIN cache items. */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_ANY, n)); + if (i && i->type == DNS_CACHE_NXDOMAIN) + return i; + + if (dns_type_may_redirect(k->type)) { + /* Check if we have a CNAME record instead */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_CNAME, n)); + if (i) + return i; + + /* OK, let's look for cached DNAME records. */ + for (;;) { + if (isempty(n)) + return NULL; + + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_DNAME, n)); + if (i) + return i; + + /* Jump one label ahead */ + r = dns_name_parent(&n); + if (r <= 0) + return NULL; + } + } + + if (k->type != DNS_TYPE_NSEC) { + /* Check if we have an NSEC record instead for the name. */ + i = hashmap_get(c->by_key, &DNS_RESOURCE_KEY_CONST(k->class, DNS_TYPE_NSEC, n)); + if (i) + return i; + } + + return NULL; +} + +int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **ret, bool *authenticated) { _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; unsigned n = 0; int r; bool nxdomain = false; _cleanup_free_ char *key_str = NULL; - DnsCacheItem *j, *first; + DnsCacheItem *j, *first, *nsec = NULL; + bool have_authenticated = false, have_non_authenticated = false; assert(c); assert(key); assert(rcode); assert(ret); + assert(authenticated); if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { - /* If we have ANY lookups we simply refresh */ + /* If we have ANY lookups we don't use the cache, so + * that the caller refreshes via the network. */ - r = dns_resource_key_to_string(key, &key_str); - if (r < 0) - return r; + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("Ignoring cache for ANY lookup: %s", key_str); + } - log_debug("Ignoring cache for ANY lookup: %s", key_str); + c->n_miss++; *ret = NULL; *rcode = DNS_RCODE_SUCCESS; return 0; } - first = hashmap_get(c->by_key, key); + first = dns_cache_get_by_key_follow_cname_dname_nsec(c, key); if (!first) { /* If one question cannot be answered we need to refresh */ - r = dns_resource_key_to_string(key, &key_str); - if (r < 0) - return r; + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("Cache miss for %s", key_str); + } - log_debug("Cache miss for %s", key_str); + c->n_miss++; *ret = NULL; *rcode = DNS_RCODE_SUCCESS; @@ -543,24 +821,65 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **r } LIST_FOREACH(by_key, j, first) { - if (j->rr) + if (j->rr) { + if (j->rr->key->type == DNS_TYPE_NSEC) + nsec = j; + n++; - else if (j->type == DNS_CACHE_NXDOMAIN) + } else if (j->type == DNS_CACHE_NXDOMAIN) nxdomain = true; + + if (j->authenticated) + have_authenticated = true; + else + have_non_authenticated = true; } - r = dns_resource_key_to_string(key, &key_str); - if (r < 0) - return r; + if (nsec && key->type != DNS_TYPE_NSEC) { + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("NSEC NODATA cache hit for %s", key_str); + } + + /* We only found an NSEC record that matches our name. + * If it says the type doesn't exist report + * NODATA. Otherwise report a cache miss. */ - log_debug("%s cache hit for %s", - nxdomain ? "NXDOMAIN" : - n > 0 ? "Positive" : "NODATA", - key_str); + *ret = NULL; + *rcode = DNS_RCODE_SUCCESS; + *authenticated = nsec->authenticated; + + if (!bitmap_isset(nsec->rr->nsec.types, key->type) && + !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_CNAME) && + !bitmap_isset(nsec->rr->nsec.types, DNS_TYPE_DNAME)) { + c->n_hit++; + return 1; + } + + c->n_miss++; + return 0; + } + + if (log_get_max_level() >= LOG_DEBUG) { + r = dns_resource_key_to_string(key, &key_str); + if (r < 0) + return r; + + log_debug("%s cache hit for %s", + n > 0 ? "Positive" : + nxdomain ? "NXDOMAIN" : "NODATA", + key_str); + } if (n <= 0) { + c->n_hit++; + *ret = NULL; *rcode = nxdomain ? DNS_RCODE_NXDOMAIN : DNS_RCODE_SUCCESS; + *authenticated = have_authenticated && !have_non_authenticated; return 1; } @@ -572,13 +891,16 @@ int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **r if (!j->rr) continue; - r = dns_answer_add(answer, j->rr, 0); + r = dns_answer_add(answer, j->rr, 0, j->authenticated ? DNS_ANSWER_AUTHENTICATED : 0); if (r < 0) return r; } + c->n_hit++; + *ret = answer; *rcode = DNS_RCODE_SUCCESS; + *authenticated = have_authenticated && !have_non_authenticated; answer = NULL; return n; @@ -620,6 +942,55 @@ int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_ return 1; } +int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p) { + unsigned ancount = 0; + Iterator iterator; + DnsCacheItem *i; + int r; + + assert(cache); + assert(p); + + HASHMAP_FOREACH(i, cache->by_key, iterator) { + DnsCacheItem *j; + + LIST_FOREACH(by_key, j, i) { + if (!j->rr) + continue; + + if (!j->shared_owner) + continue; + + r = dns_packet_append_rr(p, j->rr, NULL, NULL); + if (r == -EMSGSIZE && p->protocol == DNS_PROTOCOL_MDNS) { + /* For mDNS, if we're unable to stuff all known answers into the given packet, + * allocate a new one, push the RR into that one and link it to the current one. + */ + + DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); + ancount = 0; + + r = dns_packet_new_query(&p->more, p->protocol, 0, true); + if (r < 0) + return r; + + /* continue with new packet */ + p = p->more; + r = dns_packet_append_rr(p, j->rr, NULL, NULL); + } + + if (r < 0) + return r; + + ancount ++; + } + } + + DNS_PACKET_HEADER(p)->ancount = htobe16(ancount); + + return 0; +} + void dns_cache_dump(DnsCache *cache, FILE *f) { Iterator iterator; DnsCacheItem *i; @@ -635,13 +1006,13 @@ void dns_cache_dump(DnsCache *cache, FILE *f) { DnsCacheItem *j; LIST_FOREACH(by_key, j, i) { - _cleanup_free_ char *t = NULL; fputc('\t', f); if (j->rr) { - r = dns_resource_record_to_string(j->rr, &t); - if (r < 0) { + const char *t; + t = dns_resource_record_to_string(j->rr); + if (!t) { log_oom(); continue; } @@ -649,13 +1020,14 @@ void dns_cache_dump(DnsCache *cache, FILE *f) { fputs(t, f); fputc('\n', f); } else { - r = dns_resource_key_to_string(j->key, &t); + _cleanup_free_ char *z = NULL; + r = dns_resource_key_to_string(j->key, &z); if (r < 0) { log_oom(); continue; } - fputs(t, f); + fputs(z, f); fputs(" -- ", f); fputs(j->type == DNS_CACHE_NODATA ? "NODATA" : "NXDOMAIN", f); fputc('\n', f); @@ -670,3 +1042,10 @@ bool dns_cache_is_empty(DnsCache *cache) { return hashmap_isempty(cache->by_key); } + +unsigned dns_cache_size(DnsCache *cache) { + if (!cache) + return 0; + + return hashmap_size(cache->by_key); +} diff --git a/src/resolve/resolved-dns-cache.h b/src/resolve/resolved-dns-cache.h index 1225e58de4..e61b285df4 100644 --- a/src/resolve/resolved-dns-cache.h +++ b/src/resolve/resolved-dns-cache.h @@ -21,28 +21,34 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ - #include "hashmap.h" +#include "list.h" #include "prioq.h" #include "time-util.h" -#include "list.h" typedef struct DnsCache { Hashmap *by_key; Prioq *by_expiry; + unsigned n_hit; + unsigned n_miss; } DnsCache; -#include "resolved-dns-rr.h" -#include "resolved-dns-question.h" #include "resolved-dns-answer.h" +#include "resolved-dns-packet.h" +#include "resolved-dns-question.h" +#include "resolved-dns-rr.h" void dns_cache_flush(DnsCache *c); void dns_cache_prune(DnsCache *c); -int dns_cache_put(DnsCache *c, DnsQuestion *q, int rcode, DnsAnswer *answer, unsigned max_rrs, usec_t timestamp, int owner_family, const union in_addr_union *owner_address); -int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **answer); +int dns_cache_put(DnsCache *c, DnsResourceKey *key, int rcode, DnsAnswer *answer, bool authenticated, uint32_t nsec_ttl, usec_t timestamp, int owner_family, const union in_addr_union *owner_address); +int dns_cache_lookup(DnsCache *c, DnsResourceKey *key, int *rcode, DnsAnswer **answer, bool *authenticated); int dns_cache_check_conflicts(DnsCache *cache, DnsResourceRecord *rr, int owner_family, const union in_addr_union *owner_address); void dns_cache_dump(DnsCache *cache, FILE *f); bool dns_cache_is_empty(DnsCache *cache); + +unsigned dns_cache_size(DnsCache *cache); + +int dns_cache_export_shared_to_packet(DnsCache *cache, DnsPacket *p); diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c new file mode 100644 index 0000000000..1f48f588ce --- /dev/null +++ b/src/resolve/resolved-dns-dnssec.c @@ -0,0 +1,2131 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <gcrypt.h> + +#include "alloc-util.h" +#include "dns-domain.h" +#include "hexdecoct.h" +#include "resolved-dns-dnssec.h" +#include "resolved-dns-packet.h" +#include "string-table.h" + +/* Open question: + * + * How does the DNSSEC canonical form of a hostname with a label + * containing a dot look like, the way DNS-SD does it? + * + * TODO: + * + * - bus calls to override DNSEC setting per interface + * - log all DNSSEC downgrades + * - log all RRs that failed validation + * - enable by default + * - Allow clients to request DNSSEC even if DNSSEC is off + * - make sure when getting an NXDOMAIN response through CNAME, we still process the first CNAMEs in the packet + * */ + +#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 + */ + +static void initialize_libgcrypt(void) { + const char *p; + + if (gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P)) + return; + + p = gcry_check_version("1.4.5"); + assert(p); + + gcry_control(GCRYCTL_DISABLE_SECMEM); + gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0); +} + +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); +} + +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 the the RRSet matching the specified "key" in "a", + * using the signature "rrsig" and the key "dnskey". It's + * assumed the 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(); + + 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; +} + +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; +} + +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(); + + 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(); + + 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 (rr->n_skip_labels_source != 0) + return 0; + /* Ignore NSEC3 RRs that are located anywhere else than one label below the zone */ + if (rr->n_skip_labels_signer != 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' */ + + /* 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; + + if (!pp) { + /* 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; + } + + /* 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 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, NULL); + 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; +} + +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 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); +} + +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); diff --git a/src/resolve/resolved-dns-dnssec.h b/src/resolve/resolved-dns-dnssec.h new file mode 100644 index 0000000000..955017e8cb --- /dev/null +++ b/src/resolve/resolved-dns-dnssec.h @@ -0,0 +1,92 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +typedef enum DnssecMode DnssecMode; +typedef enum DnssecResult DnssecResult; + +#include "dns-domain.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-rr.h" + +enum DnssecResult { + /* These five are returned by dnssec_verify_rrset() */ + DNSSEC_VALIDATED, + DNSSEC_VALIDATED_WILDCARD, /* Validated via a wildcard RRSIG, further NSEC/NSEC3 checks necessary */ + DNSSEC_INVALID, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_UNSUPPORTED_ALGORITHM, + + /* These two are added by dnssec_verify_rrset_search() */ + DNSSEC_NO_SIGNATURE, + DNSSEC_MISSING_KEY, + + /* These two are added by the DnsTransaction logic */ + DNSSEC_UNSIGNED, + DNSSEC_FAILED_AUXILIARY, + DNSSEC_NSEC_MISMATCH, + DNSSEC_INCOMPATIBLE_SERVER, + + _DNSSEC_RESULT_MAX, + _DNSSEC_RESULT_INVALID = -1 +}; + +#define DNSSEC_CANONICAL_HOSTNAME_MAX (DNS_HOSTNAME_MAX + 2) + +/* The longest digest we'll ever generate, of all digest algorithms we support */ +#define DNSSEC_HASH_SIZE_MAX (MAX(20, 32)) + +int dnssec_rrsig_match_dnskey(DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, bool revoked_ok); +int dnssec_key_match_rrsig(const DnsResourceKey *key, DnsResourceRecord *rrsig); + +int dnssec_verify_rrset(DnsAnswer *answer, const DnsResourceKey *key, DnsResourceRecord *rrsig, DnsResourceRecord *dnskey, usec_t realtime, DnssecResult *result); +int dnssec_verify_rrset_search(DnsAnswer *answer, const DnsResourceKey *key, DnsAnswer *validated_dnskeys, usec_t realtime, DnssecResult *result, DnsResourceRecord **rrsig); + +int dnssec_verify_dnskey_by_ds(DnsResourceRecord *dnskey, DnsResourceRecord *ds, bool mask_revoke); +int dnssec_verify_dnskey_by_ds_search(DnsResourceRecord *dnskey, DnsAnswer *validated_ds); + +int dnssec_has_rrsig(DnsAnswer *a, const DnsResourceKey *key); + +uint16_t dnssec_keytag(DnsResourceRecord *dnskey, bool mask_revoke); + +int dnssec_canonicalize(const char *n, char *buffer, size_t buffer_max); + +int dnssec_nsec3_hash(DnsResourceRecord *nsec3, const char *name, void *ret); + +typedef enum DnssecNsecResult { + DNSSEC_NSEC_NO_RR, /* No suitable NSEC/NSEC3 RR found */ + DNSSEC_NSEC_CNAME, /* Didn't find what was asked for, but did find CNAME */ + DNSSEC_NSEC_UNSUPPORTED_ALGORITHM, + DNSSEC_NSEC_NXDOMAIN, + DNSSEC_NSEC_NODATA, + DNSSEC_NSEC_FOUND, + DNSSEC_NSEC_OPTOUT, +} DnssecNsecResult; + +int dnssec_nsec_test(DnsAnswer *answer, DnsResourceKey *key, DnssecNsecResult *result, bool *authenticated, uint32_t *ttl); + +int dnssec_nsec_test_enclosed(DnsAnswer *answer, uint16_t type, const char *name, const char *zone, bool *authenticated); + +int dnssec_test_positive_wildcard(DnsAnswer *a, const char *name, const char *source, const char *zone, bool *authenticated); + +const char* dnssec_result_to_string(DnssecResult m) _const_; +DnssecResult dnssec_result_from_string(const char *s) _pure_; diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c index bebd1ee4a6..9a5223ef01 100644 --- a/src/resolve/resolved-dns-packet.c +++ b/src/resolve/resolved-dns-packet.c @@ -19,12 +19,16 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "utf8.h" -#include "util.h" -#include "strv.h" -#include "unaligned.h" +#include "alloc-util.h" #include "dns-domain.h" #include "resolved-dns-packet.h" +#include "string-table.h" +#include "strv.h" +#include "unaligned.h" +#include "utf8.h" +#include "util.h" + +#define EDNS0_OPT_DO (1<<15) int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { DnsPacket *p; @@ -54,6 +58,7 @@ int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { 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; @@ -61,20 +66,18 @@ int dns_packet_new(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { return 0; } -int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { - DnsPacket *p; - DnsPacketHeader *h; - int r; +void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated) { - assert(ret); + DnsPacketHeader *h; - r = dns_packet_new(&p, protocol, mtu); - if (r < 0) - return r; + assert(p); h = DNS_PACKET_HEADER(p); - if (protocol == DNS_PROTOCOL_LLMNR) + switch(p->protocol) { + case DNS_PROTOCOL_LLMNR: + assert(!truncated); + h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, 0 /* opcode */, 0 /* c */, @@ -84,7 +87,23 @@ int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { 0 /* ad */, 0 /* cd */, 0 /* rcode */)); - else + 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 */, @@ -92,8 +111,25 @@ int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu) { 1 /* rd (ask for recursion) */, 0 /* ra */, 0 /* ad */, - 0 /* cd */, + 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; @@ -104,6 +140,8 @@ DnsPacket *dns_packet_ref(DnsPacket *p) { if (!p) return NULL; + assert(!p->on_stack); + assert(p->n_ref > 0); p->n_ref++; return p; @@ -116,13 +154,16 @@ static void dns_packet_free(DnsPacket *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); - free(p); + + if (!p->on_stack) + free(p); } DnsPacket *dns_packet_unref(DnsPacket *p) { @@ -131,6 +172,8 @@ DnsPacket *dns_packet_unref(DnsPacket *p) { assert(p->n_ref > 0); + dns_packet_unref(p->more); + if (p->n_ref == 1) dns_packet_free(p); else @@ -167,6 +210,7 @@ int dns_packet_validate_reply(DnsPacket *p) { 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) @@ -174,6 +218,13 @@ int dns_packet_validate_reply(DnsPacket *p) { break; + case DNS_PROTOCOL_MDNS: + /* RFC 6762, Section 18 */ + if (DNS_PACKET_RCODE(p) != 0) + return -EBADMSG; + + break; + default: break; } @@ -200,6 +251,7 @@ int dns_packet_validate_query(DnsPacket *p) { return -EBADMSG; switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ if (DNS_PACKET_QDCOUNT(p) != 1) @@ -215,6 +267,18 @@ int dns_packet_validate_query(DnsPacket *p) { 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; } @@ -265,7 +329,7 @@ static int dns_packet_extend(DnsPacket *p, size_t add, void **ret, size_t *start return 0; } -static void dns_packet_truncate(DnsPacket *p, size_t sz) { +void dns_packet_truncate(DnsPacket *p, size_t sz) { Iterator i; char *s; void *n; @@ -347,43 +411,68 @@ int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start) { } int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start) { + 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; - size_t l; int r; assert(p); - assert(s); + assert(s || size == 0); - l = strlen(s); - if (l > 255) + if (size > 255) return -E2BIG; - r = dns_packet_extend(p, 1 + l, &d, start); + r = dns_packet_extend(p, 1 + size, &d, start); if (r < 0) return r; - ((uint8_t*) d)[0] = (uint8_t) l; - memcpy(((uint8_t*) d) + 1, s, l); + ((uint8_t*) d)[0] = (uint8_t) size; + + if (size > 0) + memcpy(((uint8_t*) d) + 1, s, size); return 0; } -int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start) { - void *w; +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, &w, start); + r = dns_packet_extend(p, 1 + l, (void**) &w, start); if (r < 0) return r; - ((uint8_t*) w)[0] = (uint8_t) l; - memcpy(((uint8_t*) w) + 1, d, l); + *(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; } @@ -392,6 +481,7 @@ int dns_packet_append_name( DnsPacket *p, const char *name, bool allow_compression, + bool canonical_candidate, size_t *start) { size_t saved_size; @@ -405,11 +495,10 @@ int dns_packet_append_name( saved_size = p->size; - while (*name) { - _cleanup_free_ char *s = NULL; + while (!dns_name_is_root(name)) { + const char *z = name; char label[DNS_LABEL_MAX]; size_t n = 0; - int k; if (allow_compression) n = PTR_TO_SIZE(hashmap_get(p->names, name)); @@ -425,32 +514,23 @@ int dns_packet_append_name( } } - s = strdup(name); - if (!s) { - r = -ENOMEM; - goto fail; - } - r = dns_label_unescape(&name, label, sizeof(label)); if (r < 0) goto fail; - if (p->protocol == DNS_PROTOCOL_DNS) - k = dns_label_apply_idna(label, r, label, sizeof(label)); - else - k = dns_label_undo_idna(label, r, label, sizeof(label)); - if (k < 0) { - r = k; - goto fail; - } - if (k > 0) - r = k; - - r = dns_packet_append_label(p, label, r, &n); + 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; @@ -487,7 +567,7 @@ int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start) saved_size = p->size; - r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, NULL); + r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, true, NULL); if (r < 0) goto fail; @@ -509,7 +589,7 @@ fail: return r; } -static int dns_packet_append_type_window(DnsPacket *p, uint8_t window, uint8_t length, uint8_t *types, size_t *start) { +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; @@ -550,7 +630,6 @@ static int dns_packet_append_types(DnsPacket *p, Bitmap *types, size_t *start) { int r; assert(p); - assert(types); saved_size = p->size; @@ -566,27 +645,143 @@ static int dns_packet_append_types(DnsPacket *p, Bitmap *types, size_t *start) { } window = n >> 8; - entry = n & 255; bitmaps[entry / 8] |= 1 << (7 - (entry % 8)); } - r = dns_packet_append_type_window(p, window, entry / 8 + 1, bitmaps, NULL); + 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, 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); + + 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; + + /* 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, 0, 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) { + /* If DO is on, 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_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start) { - size_t saved_size, rdlength_offset, end, rdlength; +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); @@ -607,6 +802,8 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star if (r < 0) goto fail; + rds = p->size - saved_size; + switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { case DNS_TYPE_SRV: @@ -622,14 +819,14 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star if (r < 0) goto fail; - r = dns_packet_append_name(p, rr->srv.name, true, NULL); + 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, NULL); + r = dns_packet_append_name(p, rr->ptr.name, true, false, NULL); break; case DNS_TYPE_HINFO: @@ -641,19 +838,20 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star break; case DNS_TYPE_SPF: /* exactly the same as TXT */ - case DNS_TYPE_TXT: { - char **s; + case DNS_TYPE_TXT: - if (strv_isempty(rr->txt.strings)) { + if (!rr->txt.items) { /* RFC 6763, section 6.1 suggests to generate * single empty string for an empty array. */ - r = dns_packet_append_string(p, "", NULL); + r = dns_packet_append_raw_string(p, NULL, 0, NULL); if (r < 0) goto fail; } else { - STRV_FOREACH(s, rr->txt.strings) { - r = dns_packet_append_string(p, *s, NULL); + 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; } @@ -661,7 +859,6 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star r = 0; break; - } case DNS_TYPE_A: r = dns_packet_append_blob(p, &rr->a.in_addr, sizeof(struct in_addr), NULL); @@ -672,11 +869,11 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star break; case DNS_TYPE_SOA: - r = dns_packet_append_name(p, rr->soa.mname, true, NULL); + 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, NULL); + r = dns_packet_append_name(p, rr->soa.rname, true, false, NULL); if (r < 0) goto fail; @@ -704,7 +901,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star if (r < 0) goto fail; - r = dns_packet_append_name(p, rr->mx.exchange, true, NULL); + r = dns_packet_append_name(p, rr->mx.exchange, true, false, NULL); break; case DNS_TYPE_LOC: @@ -764,11 +961,11 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star break; case DNS_TYPE_DNSKEY: - r = dns_packet_append_uint16(p, dnskey_to_flags(rr), NULL); + r = dns_packet_append_uint16(p, rr->dnskey.flags, NULL); if (r < 0) goto fail; - r = dns_packet_append_uint8(p, 3u, NULL); + r = dns_packet_append_uint8(p, rr->dnskey.protocol, NULL); if (r < 0) goto fail; @@ -808,7 +1005,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star if (r < 0) goto fail; - r = dns_packet_append_name(p, rr->rrsig.signer, false, NULL); + r = dns_packet_append_name(p, rr->rrsig.signer, false, true, NULL); if (r < 0) goto fail; @@ -816,7 +1013,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star break; case DNS_TYPE_NSEC: - r = dns_packet_append_name(p, rr->nsec.next_domain_name, false, NULL); + r = dns_packet_append_name(p, rr->nsec.next_domain_name, false, false, NULL); if (r < 0) goto fail; @@ -825,6 +1022,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star goto fail; break; + case DNS_TYPE_NSEC3: r = dns_packet_append_uint8(p, rr->nsec3.algorithm, NULL); if (r < 0) @@ -859,6 +1057,8 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star goto fail; break; + + case DNS_TYPE_OPT: case _DNS_TYPE_INVALID: /* unparseable */ default: @@ -871,7 +1071,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star /* Let's calculate the actual data size and update the field */ rdlength = p->size - rdlength_offset - sizeof(uint16_t); if (rdlength > 0xFFFF) { - r = ENOSPC; + r = -ENOSPC; goto fail; } @@ -885,6 +1085,9 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star if (start) *start = saved_size; + if (rdata_start) + *rdata_start = rds; + return 0; fail: @@ -892,7 +1095,6 @@ fail: return r; } - int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) { assert(p); @@ -1060,6 +1262,35 @@ fail: return r; } +int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start) { + size_t saved_rindex; + uint8_t c; + int r; + + assert(p); + + saved_rindex = p->rindex; + + r = dns_packet_read_uint8(p, &c, NULL); + if (r < 0) + goto fail; + + r = dns_packet_read(p, c, ret, NULL); + if (r < 0) + goto fail; + + if (size) + *size = c; + if (start) + *start = saved_rindex; + + return 0; + +fail: + dns_packet_rewind(p, saved_rindex); + return r; +} + int dns_packet_read_name( DnsPacket *p, char **_ret, @@ -1092,7 +1323,6 @@ int dns_packet_read_name( /* End of name */ break; else if (c <= 63) { - _cleanup_free_ char *t = NULL; const char *label; /* Literal label */ @@ -1100,21 +1330,20 @@ int dns_packet_read_name( if (r < 0) goto fail; - r = dns_label_escape(label, c, &t); - if (r < 0) - goto fail; - - if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1)) { + if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) { r = -ENOMEM; goto fail; } - if (!first) - ret[n++] = '.'; - else + if (first) first = false; + else + ret[n++] = '.'; + + r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); + if (r < 0) + goto fail; - memcpy(ret + n, t, r); n += r; continue; } else if (allow_compression && (c & 0xc0) == 0xc0) { @@ -1275,8 +1504,9 @@ fail: return r; } -int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) { +int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start) { _cleanup_free_ char *name = NULL; + bool cache_flush = false; uint16_t class, type; DnsResourceKey *key; size_t saved_rindex; @@ -1299,6 +1529,15 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) { if (r < 0) goto fail; + 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) { r = -ENOMEM; @@ -1308,6 +1547,8 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) { name = NULL; *ret = key; + if (ret_cache_flush) + *ret_cache_flush = cache_flush; if (start) *start = saved_rindex; @@ -1323,22 +1564,12 @@ static bool loc_size_ok(uint8_t size) { return m <= 9 && e <= 9 && (m > 0 || e == 0); } -static int dnskey_parse_flags(DnsResourceRecord *rr, uint16_t flags) { - assert(rr); - - if (flags & ~(DNSKEY_FLAG_SEP | DNSKEY_FLAG_ZONE_KEY)) - return -EBADMSG; - - rr->dnskey.zone_key_flag = flags & DNSKEY_FLAG_ZONE_KEY; - rr->dnskey.sep_flag = flags & DNSKEY_FLAG_SEP; - return 0; -} - -int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { +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; size_t saved_rindex, offset; uint16_t rdlength; + bool cache_flush; int r; assert(p); @@ -1346,12 +1577,12 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { saved_rindex = p->rindex; - r = dns_packet_read_key(p, &key, NULL); + r = dns_packet_read_key(p, &key, &cache_flush, NULL); if (r < 0) goto fail; - if (key->class == DNS_CLASS_ANY || - key->type == DNS_TYPE_ANY) { + if (!dns_class_is_valid_rr(key->class)|| + !dns_type_is_valid_rr(key->type)) { r = -EBADMSG; goto fail; } @@ -1366,6 +1597,11 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { if (r < 0) goto fail; + /* 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) goto fail; @@ -1410,24 +1646,37 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { 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. */ - r = strv_extend(&rr->txt.strings, ""); - if (r < 0) - goto fail; + 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) { - char *s; + DnsTxtItem *i; + const void *data; + size_t sz; - r = dns_packet_read_string(p, &s, NULL); + r = dns_packet_read_raw_string(p, &data, &sz, NULL); if (r < 0) - goto fail; + return r; - r = strv_consume(&rr->txt.strings, s); - if (r < 0) - goto fail; + 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; } } @@ -1563,6 +1812,7 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { } break; + case DNS_TYPE_SSHFP: r = dns_packet_read_uint8(p, &rr->sshfp.algorithm, NULL); if (r < 0) @@ -1585,28 +1835,15 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { break; - case DNS_TYPE_DNSKEY: { - uint16_t flags; - uint8_t proto; - - r = dns_packet_read_uint16(p, &flags, NULL); - if (r < 0) - goto fail; - - r = dnskey_parse_flags(rr, flags); + case DNS_TYPE_DNSKEY: + r = dns_packet_read_uint16(p, &rr->dnskey.flags, NULL); if (r < 0) goto fail; - r = dns_packet_read_uint8(p, &proto, NULL); + r = dns_packet_read_uint8(p, &rr->dnskey.protocol, NULL); if (r < 0) goto fail; - /* protocol is required to be always 3 */ - if (proto != 3) { - r = -EBADMSG; - goto fail; - } - r = dns_packet_read_uint8(p, &rr->dnskey.algorithm, NULL); if (r < 0) goto fail; @@ -1623,7 +1860,6 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { } break; - } case DNS_TYPE_RRSIG: r = dns_packet_read_uint16(p, &rr->rrsig.type_covered, NULL); @@ -1671,8 +1907,16 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { break; - case DNS_TYPE_NSEC: - r = dns_packet_read_name(p, &rr->nsec.next_domain_name, false, NULL); + 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) goto fail; @@ -1680,15 +1924,12 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { if (r < 0) goto fail; - /* The types bitmap must contain at least the NSEC record itself, so an empty bitmap means - something went wrong */ - if (bitmap_isclear(rr->nsec.types)) { - r = -EBADMSG; - goto fail; - } + /* 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; @@ -1734,6 +1975,8 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { break; } + + case DNS_TYPE_OPT: /* we only care about the header of OPT for now. */ default: unparseable: r = dns_packet_read_memdup(p, rdlength, &rr->generic.data, &rr->generic.size, NULL); @@ -1751,6 +1994,8 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) { *ret = rr; rr = NULL; + if (ret_cache_flush) + *ret_cache_flush = cache_flush; if (start) *start = saved_rindex; @@ -1760,6 +2005,48 @@ fail: return r; } +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) + return false; + + p = rr->opt.data; + l = rr->opt.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; @@ -1783,11 +2070,22 @@ int dns_packet_extract(DnsPacket *p) { for (i = 0; i < n; i++) { _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + bool cache_flush; - r = dns_packet_read_key(p, &key, NULL); + r = dns_packet_read_key(p, &key, &cache_flush, NULL); if (r < 0) goto finish; + if (cache_flush) { + r = -EBADMSG; + goto finish; + } + + if (!dns_type_is_valid_query(key->type)) { + r = -EBADMSG; + goto finish; + } + r = dns_question_add(question, key); if (r < 0) goto finish; @@ -1796,6 +2094,9 @@ int dns_packet_extract(DnsPacket *p) { n = DNS_PACKET_RRCOUNT(p); if (n > 0) { + DnsResourceRecord *previous = NULL; + bool bad_opt = false; + answer = dns_answer_new(n); if (!answer) { r = -ENOMEM; @@ -1804,15 +2105,79 @@ int dns_packet_extract(DnsPacket *p) { for (i = 0; i < n; i++) { _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + bool cache_flush; - r = dns_packet_read_rr(p, &rr, NULL); + r = dns_packet_read_rr(p, &rr, &cache_flush, NULL); if (r < 0) goto finish; - r = dns_answer_add(answer, rr, p->ifindex); - if (r < 0) - goto finish; + /* 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 qis 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 (has_rfc6975) { + /* 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 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) + goto finish; + } } + + if (bad_opt) + p->opt = dns_resource_record_unref(p->opt); } p->question = question; @@ -1830,6 +2195,30 @@ finish: return r; } +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", @@ -1858,17 +2247,3 @@ static const char* const dns_protocol_table[_DNS_PROTOCOL_MAX] = { [DNS_PROTOCOL_LLMNR] = "llmnr", }; DEFINE_STRING_TABLE_LOOKUP(dns_protocol, DnsProtocol); - -static const char* const dnssec_algorithm_table[_DNSSEC_ALGORITHM_MAX_DEFINED] = { - [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_INDIRECT] = "INDIRECT", - [DNSSEC_ALGORITHM_PRIVATEDNS] = "PRIVATEDNS", - [DNSSEC_ALGORITHM_PRIVATEOID] = "PRIVATEOID", -}; -DEFINE_STRING_TABLE_LOOKUP(dnssec_algorithm, int); diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index fbbabaf232..c53431576b 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -21,21 +21,21 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include <netinet/udp.h> #include <netinet/ip.h> +#include <netinet/udp.h> -#include "macro.h" -#include "sparse-endian.h" #include "hashmap.h" #include "in-addr-util.h" +#include "macro.h" +#include "sparse-endian.h" typedef struct DnsPacketHeader DnsPacketHeader; typedef struct DnsPacket DnsPacket; -#include "resolved-dns-rr.h" -#include "resolved-dns-question.h" -#include "resolved-dns-answer.h" #include "resolved-def.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-question.h" +#include "resolved-dns-rr.h" typedef enum DnsProtocol { DNS_PROTOCOL_DNS, @@ -65,6 +65,9 @@ struct DnsPacketHeader { /* RFC 1035 say 512 is the maximum, for classic unicast DNS */ #define DNS_PACKET_UNICAST_SIZE_MAX 512 +/* With EDNS0 we can use larger packets, default to 4096, which is what is commonly used */ +#define DNS_PACKET_UNICAST_SIZE_LARGE_MAX 4096 + #define DNS_PACKET_SIZE_START 512 struct DnsPacket { @@ -73,10 +76,12 @@ struct DnsPacket { size_t size, allocated, rindex; void *_data; /* don't access directly, use DNS_PACKET_DATA()! */ Hashmap *names; /* For name compression */ + size_t opt_start, opt_size; /* Parsed data */ DnsQuestion *question; DnsAnswer *answer; + DnsResourceRecord *opt; /* Packet reception metadata */ int ifindex; @@ -85,8 +90,13 @@ struct DnsPacket { uint16_t sender_port, destination_port; uint32_t ttl; - bool extracted; - bool refuse_compression; + /* For support of truncated packets */ + DnsPacket *more; + + bool on_stack:1; + bool extracted:1; + bool refuse_compression:1; + bool canonical_form:1; }; static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { @@ -109,7 +119,17 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { #define DNS_PACKET_RA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 7) & 1) #define DNS_PACKET_AD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 5) & 1) #define DNS_PACKET_CD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 4) & 1) -#define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15) + +static inline uint16_t DNS_PACKET_RCODE(DnsPacket *p) { + uint16_t rcode; + + if (p->opt) + rcode = (uint16_t) (p->opt->ttl >> 24); + else + rcode = 0; + + return rcode | (be16toh(DNS_PACKET_HEADER(p)->flags) & 15); +} /* LLMNR defines some bits differently */ #define DNS_PACKET_LLMNR_C(p) DNS_PACKET_AA(p) @@ -139,7 +159,9 @@ static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) { } int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu); -int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu); +int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled); + +void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated); DnsPacket *dns_packet_ref(DnsPacket *p); DnsPacket *dns_packet_unref(DnsPacket *p); @@ -150,16 +172,22 @@ int dns_packet_validate(DnsPacket *p); int dns_packet_validate_reply(DnsPacket *p); int dns_packet_validate_query(DnsPacket *p); +int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key); + int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start); int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start); int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start); int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start); int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start); -int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, size_t *start); -int dns_packet_append_name(DnsPacket *p, const char *name, - bool allow_compression, size_t *start); +int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_t *start); +int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, bool canonical_candidate, size_t *start); +int dns_packet_append_name(DnsPacket *p, const char *name, bool allow_compression, bool canonical_candidate, size_t *start); int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start); -int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start); +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start); +int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start); + +void dns_packet_truncate(DnsPacket *p, size_t sz); +int dns_packet_truncate_opt(DnsPacket *p); int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start); int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start); @@ -167,16 +195,25 @@ int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start); int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start); int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start); int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start); -int dns_packet_read_name(DnsPacket *p, char **ret, - bool allow_compression, size_t *start); -int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start); -int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start); +int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start); +int dns_packet_read_name(DnsPacket *p, char **ret, bool allow_compression, size_t *start); +int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start); +int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_flush, size_t *start); void dns_packet_rewind(DnsPacket *p, size_t idx); int dns_packet_skip_question(DnsPacket *p); int dns_packet_extract(DnsPacket *p); +static inline bool DNS_PACKET_SHALL_CACHE(DnsPacket *p) { + /* Never cache data originating from localhost, under the + * assumption, that it's coming from a locally DNS forwarder + * or server, that is caching on its own. */ + + return in_addr_is_localhost(p->family, &p->sender) == 0; +} + +/* https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-6 */ enum { DNS_RCODE_SUCCESS = 0, DNS_RCODE_FORMERR = 1, @@ -209,42 +246,25 @@ DnsProtocol dns_protocol_from_string(const char *s) _pure_; #define LLMNR_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 252U) }) #define LLMNR_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x03 } }) -#define DNSKEY_FLAG_ZONE_KEY (1u << 8) -#define DNSKEY_FLAG_SEP (1u << 0) +#define MDNS_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 251U) }) +#define MDNS_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfb } }) -static inline uint16_t dnskey_to_flags(const DnsResourceRecord *rr) { - return (rr->dnskey.zone_key_flag * DNSKEY_FLAG_ZONE_KEY | - rr->dnskey.sep_flag * DNSKEY_FLAG_SEP); -} +static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family, bool authenticated) { + uint64_t f; -/* http://tools.ietf.org/html/rfc4034#appendix-A.1 */ -enum { - DNSSEC_ALGORITHM_RSAMD5 = 1, - DNSSEC_ALGORITHM_DH, - DNSSEC_ALGORITHM_DSA, - DNSSEC_ALGORITHM_ECC, - DNSSEC_ALGORITHM_RSASHA1, - DNSSEC_ALGORITHM_DSA_NSEC3_SHA1, - DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1, - DNSSEC_ALGORITHM_INDIRECT = 252, - DNSSEC_ALGORITHM_PRIVATEDNS, - DNSSEC_ALGORITHM_PRIVATEOID, - _DNSSEC_ALGORITHM_MAX_DEFINED -}; + /* Converts a protocol + family into a flags field as used in queries and responses */ -const char* dnssec_algorithm_to_string(int i) _const_; -int dnssec_algorithm_from_string(const char *s) _pure_; - -static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family) { - - /* Converts a protocol + family into a flags field as used in queries */ + f = authenticated ? SD_RESOLVED_AUTHENTICATED : 0; switch (protocol) { case DNS_PROTOCOL_DNS: - return SD_RESOLVED_DNS; + return f|SD_RESOLVED_DNS; case DNS_PROTOCOL_LLMNR: - return family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4; + return f|(family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4); + + case DNS_PROTOCOL_MDNS: + return family == AF_INET6 ? SD_RESOLVED_MDNS_IPV6 : SD_RESOLVED_MDNS_IPV4; default: break; diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c index c0b4c8ba81..fc5bf4020f 100644 --- a/src/resolve/resolved-dns-query.c +++ b/src/resolve/resolved-dns-query.c @@ -19,44 +19,340 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "hostname-util.h" +#include "alloc-util.h" #include "dns-domain.h" +#include "hostname-util.h" #include "local-addresses.h" - #include "resolved-dns-query.h" +#include "string-util.h" /* How long to wait for the query in total */ #define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC) #define CNAME_MAX 8 #define QUERIES_MAX 2048 +#define AUXILIARY_QUERIES_MAX 64 -static void dns_query_stop(DnsQuery *q) { - DnsTransaction *t; +static int dns_query_candidate_new(DnsQueryCandidate **ret, DnsQuery *q, DnsScope *s) { + DnsQueryCandidate *c; + assert(ret); assert(q); + assert(s); - q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); + c = new0(DnsQueryCandidate, 1); + if (!c) + return -ENOMEM; + + c->query = q; + c->scope = s; + + LIST_PREPEND(candidates_by_query, q->candidates, c); + LIST_PREPEND(candidates_by_scope, s->query_candidates, c); + + *ret = c; + return 0; +} - while ((t = set_steal_first(q->transactions))) { - set_remove(t->queries, q); +static void dns_query_candidate_stop(DnsQueryCandidate *c) { + DnsTransaction *t; + + assert(c); + + while ((t = set_steal_first(c->transactions))) { + set_remove(t->notify_query_candidates, c); dns_transaction_gc(t); } } +DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c) { + + if (!c) + return NULL; + + dns_query_candidate_stop(c); + + set_free(c->transactions); + dns_search_domain_unref(c->search_domain); + + if (c->query) + LIST_REMOVE(candidates_by_query, c->query->candidates, c); + + if (c->scope) + LIST_REMOVE(candidates_by_scope, c->scope->query_candidates, c); + + free(c); + + return NULL; +} + +static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) { + DnsSearchDomain *next = NULL; + + assert(c); + + if (c->search_domain && c->search_domain->linked) { + next = c->search_domain->domains_next; + + if (!next) /* We hit the end of the list */ + return 0; + + } else { + next = dns_scope_get_search_domains(c->scope); + + if (!next) /* OK, there's nothing. */ + return 0; + } + + dns_search_domain_unref(c->search_domain); + c->search_domain = dns_search_domain_ref(next); + + return 1; +} + +static int dns_query_candidate_add_transaction(DnsQueryCandidate *c, DnsResourceKey *key) { + DnsTransaction *t; + int r; + + assert(c); + assert(key); + + t = dns_scope_find_transaction(c->scope, key, true); + if (!t) { + r = dns_transaction_new(&t, c->scope, key); + if (r < 0) + return r; + } else { + if (set_contains(c->transactions, t)) + return 0; + } + + r = set_ensure_allocated(&c->transactions, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&t->notify_query_candidates, NULL); + if (r < 0) + goto gc; + + r = set_put(t->notify_query_candidates, c); + if (r < 0) + goto gc; + + r = set_put(c->transactions, t); + if (r < 0) { + (void) set_remove(t->notify_query_candidates, c); + goto gc; + } + + return 1; + +gc: + dns_transaction_gc(t); + return r; +} + +static int dns_query_candidate_go(DnsQueryCandidate *c) { + DnsTransaction *t; + Iterator i; + int r; + + assert(c); + + /* Start the transactions that are not started yet */ + SET_FOREACH(t, c->transactions, i) { + if (t->state != DNS_TRANSACTION_NULL) + continue; + + r = dns_transaction_go(t); + if (r < 0) + return r; + } + + return 0; +} + +static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { + DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; + DnsTransaction *t; + Iterator i; + + assert(c); + + if (c->error_code != 0) + return DNS_TRANSACTION_RESOURCES; + + SET_FOREACH(t, c->transactions, i) { + + switch (t->state) { + + case DNS_TRANSACTION_NULL: + /* If there's a NULL transaction pending, then + * this means not all transactions where + * started yet, and we were called from within + * the stackframe that is supposed to start + * remaining transactions. In this case, + * simply claim the candidate is pending. */ + + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* If there's one transaction currently in + * VALIDATING state, then this means there's + * also one in PENDING state, hence we can + * return PENDING immediately. */ + return DNS_TRANSACTION_PENDING; + + case DNS_TRANSACTION_SUCCESS: + state = t->state; + break; + + default: + if (state != DNS_TRANSACTION_SUCCESS) + state = t->state; + + break; + } + } + + return state; +} + +static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { + DnsQuestion *question; + DnsResourceKey *key; + int n = 0, r; + + assert(c); + + dns_query_candidate_stop(c); + + question = dns_query_question_for_protocol(c->query, c->scope->protocol); + + /* Create one transaction per question key */ + DNS_QUESTION_FOREACH(key, question) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL; + + if (c->search_domain) { + r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name); + if (r < 0) + goto fail; + } + + r = dns_query_candidate_add_transaction(c, new_key ?: key); + if (r < 0) + goto fail; + + n++; + } + + return n; + +fail: + dns_query_candidate_stop(c); + return r; +} + +void dns_query_candidate_notify(DnsQueryCandidate *c) { + DnsTransactionState state; + int r; + + assert(c); + + state = dns_query_candidate_state(c); + + if (DNS_TRANSACTION_IS_LIVE(state)) + return; + + if (state != DNS_TRANSACTION_SUCCESS && c->search_domain) { + + r = dns_query_candidate_next_search_domain(c); + if (r < 0) + goto fail; + + if (r > 0) { + /* OK, there's another search domain to try, let's do so. */ + + r = dns_query_candidate_setup_transactions(c); + if (r < 0) + goto fail; + + if (r > 0) { + /* New transactions where queued. Start them and wait */ + + r = dns_query_candidate_go(c); + if (r < 0) + goto fail; + + return; + } + } + + } + + dns_query_ready(c->query); + return; + +fail: + log_warning_errno(r, "Failed to follow search domains: %m"); + c->error_code = r; + dns_query_ready(c->query); +} + +static void dns_query_stop(DnsQuery *q) { + DnsQueryCandidate *c; + + assert(q); + + q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); + + LIST_FOREACH(candidates_by_query, c, q->candidates) + dns_query_candidate_stop(c); +} + +static void dns_query_free_candidates(DnsQuery *q) { + assert(q); + + while (q->candidates) + dns_query_candidate_free(q->candidates); +} + +static void dns_query_reset_answer(DnsQuery *q) { + assert(q); + + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = 0; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_authenticated = false; + q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; + q->answer_search_domain = dns_search_domain_unref(q->answer_search_domain); +} + DnsQuery *dns_query_free(DnsQuery *q) { if (!q) return NULL; - dns_query_stop(q); - set_free(q->transactions); + while (q->auxiliary_queries) + dns_query_free(q->auxiliary_queries); - dns_question_unref(q->question); - dns_answer_unref(q->answer); + if (q->auxiliary_for) { + assert(q->auxiliary_for->n_auxiliary_queries > 0); + q->auxiliary_for->n_auxiliary_queries--; + LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q); + } + + dns_query_free_candidates(q); + + dns_question_unref(q->question_idna); + dns_question_unref(q->question_utf8); + + dns_query_reset_answer(q); sd_bus_message_unref(q->request); sd_bus_track_unref(q->bus_track); + free(q->request_address_string); + if (q->manager) { LIST_REMOVE(queries, q->manager->dns_queries, q); q->manager->n_dns_queries--; @@ -67,17 +363,50 @@ DnsQuery *dns_query_free(DnsQuery *q) { return NULL; } -int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex, uint64_t flags) { +int dns_query_new( + Manager *m, + DnsQuery **ret, + DnsQuestion *question_utf8, + DnsQuestion *question_idna, + int ifindex, uint64_t flags) { + _cleanup_(dns_query_freep) DnsQuery *q = NULL; - unsigned i; + DnsResourceKey *key; + bool good = false; int r; assert(m); - assert(question); - r = dns_question_is_valid(question); + if (dns_question_size(question_utf8) > 0) { + r = dns_question_is_valid_for_query(question_utf8); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + good = true; + } + + /* If the IDNA and UTF8 questions are the same, merge their references */ + r = dns_question_is_equal(question_idna, question_utf8); if (r < 0) return r; + if (r > 0) + question_idna = question_utf8; + else { + if (dns_question_size(question_idna) > 0) { + r = dns_question_is_valid_for_query(question_idna); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + + good = true; + } + } + + if (!good) /* don't allow empty queries */ + return -EINVAL; if (m->n_dns_queries >= QUERIES_MAX) return -EBUSY; @@ -86,18 +415,40 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex if (!q) return -ENOMEM; - q->question = dns_question_ref(question); + q->question_utf8 = dns_question_ref(question_utf8); + q->question_idna = dns_question_ref(question_idna); q->ifindex = ifindex; q->flags = flags; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; - for (i = 0; i < question->n_keys; i++) { - _cleanup_free_ char *p; + /* First dump UTF8 question */ + DNS_QUESTION_FOREACH(key, question_utf8) { + _cleanup_free_ char *p = NULL; - r = dns_resource_key_to_string(question->keys[i], &p); + r = dns_resource_key_to_string(key, &p); if (r < 0) return r; - log_debug("Looking up RR for %s", p); + log_debug("Looking up RR for %s.", strstrip(p)); + } + + /* And then dump the IDNA question, but only what hasn't been dumped already through the UTF8 question. */ + DNS_QUESTION_FOREACH(key, question_idna) { + _cleanup_free_ char *p = NULL; + + r = dns_question_contains(question_utf8, key); + if (r < 0) + return r; + if (r > 0) + continue; + + r = dns_resource_key_to_string(key, &p); + if (r < 0) + return r; + + log_debug("Looking up IDNA RR for %s.", strstrip(p)); } LIST_PREPEND(queries, m->dns_queries, q); @@ -111,10 +462,33 @@ int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex return 0; } +int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for) { + assert(q); + assert(auxiliary_for); + + /* Ensure that that the query is not auxiliary yet, and + * nothing else is auxiliary to it either */ + assert(!q->auxiliary_for); + assert(!q->auxiliary_queries); + + /* Ensure that the unit we shall be made auxiliary for isn't + * auxiliary itself */ + assert(!auxiliary_for->auxiliary_for); + + if (auxiliary_for->n_auxiliary_queries >= AUXILIARY_QUERIES_MAX) + return -EAGAIN; + + LIST_PREPEND(auxiliary_queries, auxiliary_for->auxiliary_queries, q); + q->auxiliary_for = auxiliary_for; + + auxiliary_for->n_auxiliary_queries++; + return 0; +} + static void dns_query_complete(DnsQuery *q, DnsTransactionState state) { assert(q); - assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); - assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); + assert(!DNS_TRANSACTION_IS_LIVE(state)); + assert(DNS_TRANSACTION_IS_LIVE(q->state)); /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction @@ -137,64 +511,42 @@ static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) { return 0; } -static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *key) { - DnsTransaction *t; +static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) { + DnsQueryCandidate *c; int r; assert(q); assert(s); - assert(key); - r = set_ensure_allocated(&q->transactions, NULL); + r = dns_query_candidate_new(&c, q, s); if (r < 0) return r; - t = dns_scope_find_transaction(s, key, true); - if (!t) { - r = dns_transaction_new(&t, s, key); + /* If this a single-label domain on DNS, we might append a suitable search domain first. */ + if ((q->flags & SD_RESOLVED_NO_SEARCH) == 0) { + r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question_idna)); if (r < 0) - return r; - } + goto fail; + if (r > 0) { + /* OK, we need a search domain now. Let's find one for this scope */ - r = set_ensure_allocated(&t->queries, NULL); - if (r < 0) - goto gc; + r = dns_query_candidate_next_search_domain(c); + if (r <= 0) /* if there's no search domain, then we won't add any transaction. */ + goto fail; + } + } - r = set_put(t->queries, q); + r = dns_query_candidate_setup_transactions(c); if (r < 0) - goto gc; - - r = set_put(q->transactions, t); - if (r < 0) { - set_remove(t->queries, q); - goto gc; - } + goto fail; return 0; -gc: - dns_transaction_gc(t); +fail: + dns_query_candidate_free(c); return r; } -static int dns_query_add_transaction_split(DnsQuery *q, DnsScope *s) { - unsigned i; - int r; - - assert(q); - assert(s); - - /* Create one transaction per question key */ - - for (i = 0; i < q->question->n_keys; i++) { - r = dns_query_add_transaction(q, s, q->question->keys[i]); - if (r < 0) - return r; - } - - return 0; -} - static int SYNTHESIZE_IFINDEX(int ifindex) { /* When the caller asked for resolving on a specific @@ -260,7 +612,7 @@ static int dns_type_to_af(uint16_t t) { } } -static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { +static int synthesize_localhost_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) { int r; assert(q); @@ -280,7 +632,7 @@ static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer * rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK); - r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex)); + r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; } @@ -294,7 +646,7 @@ static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer * rr->aaaa.in6_addr = in6addr_loopback; - r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex)); + r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; } @@ -302,7 +654,7 @@ static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer * return 0; } -static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex) { +static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex, DnsAnswerFlags flags) { _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from); @@ -313,22 +665,22 @@ static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, if (!rr->ptr.name) return -ENOMEM; - return dns_answer_add(*answer, rr, ifindex); + return dns_answer_add(*answer, rr, ifindex, flags); } -static int synthesize_localhost_ptr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { +static int synthesize_localhost_ptr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) { int r; assert(q); assert(key); assert(answer); - r = dns_answer_reserve(answer, 1); - if (r < 0) - return r; - if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) { - r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex)); + r = dns_answer_reserve(answer, 1); + if (r < 0) + return r; + + r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; } @@ -359,7 +711,7 @@ static int answer_add_addresses_rr( if (r < 0) return r; - r = dns_answer_add(*answer, rr, addresses[j].ifindex); + r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; } @@ -400,7 +752,7 @@ static int answer_add_addresses_ptr( if (r < 0) return r; - r = dns_answer_add(*answer, rr, addresses[j].ifindex); + r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; } @@ -408,7 +760,7 @@ static int answer_add_addresses_ptr( return 0; } -static int synthesize_system_hostname_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { +static int synthesize_system_hostname_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) { _cleanup_free_ struct local_address *addresses = NULL; int n = 0, af; @@ -466,15 +818,15 @@ static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_ad if (r < 0) return r; - r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex)); + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; - r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex)); + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; - r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex)); + r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; @@ -492,7 +844,7 @@ static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_ad return answer_add_addresses_ptr(answer, q->manager->mdns_hostname, addresses, n, af, address); } -static int synthesize_gateway_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { +static int synthesize_gateway_rr(DnsQuery *q, const DnsResourceKey *key, DnsAnswer **answer) { _cleanup_free_ struct local_address *addresses = NULL; int n = 0, af; @@ -527,7 +879,7 @@ static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - unsigned i; + DnsResourceKey *key; int r; assert(q); @@ -536,45 +888,45 @@ static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { /* Tries to synthesize localhost RR replies where appropriate */ if (!IN_SET(*state, - DNS_TRANSACTION_FAILURE, + DNS_TRANSACTION_RCODE_FAILURE, DNS_TRANSACTION_NO_SERVERS, DNS_TRANSACTION_TIMEOUT, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED)) return 0; - for (i = 0; i < q->question->n_keys; i++) { + DNS_QUESTION_FOREACH(key, q->question_utf8) { union in_addr_union address; const char *name; int af; - if (q->question->keys[i]->class != DNS_CLASS_IN && - q->question->keys[i]->class != DNS_CLASS_ANY) + if (key->class != DNS_CLASS_IN && + key->class != DNS_CLASS_ANY) continue; - name = DNS_RESOURCE_KEY_NAME(q->question->keys[i]); + name = DNS_RESOURCE_KEY_NAME(key); if (is_localhost(name)) { - r = synthesize_localhost_rr(q, q->question->keys[i], &answer); + r = synthesize_localhost_rr(q, key, &answer); if (r < 0) return log_error_errno(r, "Failed to synthesize localhost RRs: %m"); } else if (manager_is_own_hostname(q->manager, name)) { - r = synthesize_system_hostname_rr(q, q->question->keys[i], &answer); + r = synthesize_system_hostname_rr(q, key, &answer); if (r < 0) return log_error_errno(r, "Failed to synthesize system hostname RRs: %m"); } else if (is_gateway_hostname(name)) { - r = synthesize_gateway_rr(q, q->question->keys[i], &answer); + r = synthesize_gateway_rr(q, key, &answer); if (r < 0) return log_error_errno(r, "Failed to synthesize gateway RRs: %m"); } else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) || dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) { - r = synthesize_localhost_ptr(q, q->question->keys[i], &answer); + r = synthesize_localhost_ptr(q, key, &answer); if (r < 0) return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m"); @@ -597,9 +949,9 @@ static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { q->answer = answer; answer = NULL; - q->answer_family = SYNTHESIZE_FAMILY(q->flags); - q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags); q->answer_rcode = DNS_RCODE_SUCCESS; + q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags); + q->answer_family = SYNTHESIZE_FAMILY(q->flags); *state = DNS_TRANSACTION_SUCCESS; @@ -609,9 +961,7 @@ static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { int dns_query_go(DnsQuery *q) { DnsScopeMatch found = DNS_SCOPE_NO; DnsScope *s, *first = NULL; - DnsTransaction *t; - const char *name; - Iterator i; + DnsQueryCandidate *c; int r; assert(q); @@ -619,13 +969,13 @@ int dns_query_go(DnsQuery *q) { if (q->state != DNS_TRANSACTION_NULL) return 0; - assert(q->question); - assert(q->question->n_keys > 0); - - name = DNS_RESOURCE_KEY_NAME(q->question->keys[0]); - LIST_FOREACH(scopes, s, q->manager->dns_scopes) { DnsScopeMatch match; + const char *name; + + name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol)); + if (!name) + continue; match = dns_scope_good_domain(s, q->ifindex, q->flags, name); if (match < 0) @@ -655,12 +1005,17 @@ int dns_query_go(DnsQuery *q) { return 1; } - r = dns_query_add_transaction_split(q, first); + r = dns_query_add_candidate(q, first); if (r < 0) goto fail; LIST_FOREACH(scopes, s, first->scopes_next) { DnsScopeMatch match; + const char *name; + + name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol)); + if (!name) + continue; match = dns_scope_good_domain(s, q->ifindex, q->flags, name); if (match < 0) @@ -669,7 +1024,7 @@ int dns_query_go(DnsQuery *q) { if (match != found) continue; - r = dns_query_add_transaction_split(q, s); + r = dns_query_add_candidate(q, s); if (r < 0) goto fail; } @@ -688,17 +1043,18 @@ int dns_query_go(DnsQuery *q) { if (r < 0) goto fail; + (void) sd_event_source_set_description(q->timeout_event_source, "query-timeout"); + q->state = DNS_TRANSACTION_PENDING; q->block_ready++; - /* Start the transactions that are not started yet */ - SET_FOREACH(t, q->transactions, i) { - if (t->state != DNS_TRANSACTION_NULL) - continue; - - r = dns_transaction_go(t); - if (r < 0) + /* Start the transactions */ + LIST_FOREACH(candidates_by_query, c, q->candidates) { + r = dns_query_candidate_go(c); + if (r < 0) { + q->block_ready--; goto fail; + } } q->block_ready--; @@ -711,151 +1067,239 @@ fail: return r; } -void dns_query_ready(DnsQuery *q) { - DnsTransaction *t; +static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; - _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - int rcode = 0; - DnsScope *scope = NULL; - bool pending = false; + bool has_authenticated = false, has_non_authenticated = false; + DnssecResult dnssec_result_authenticated = _DNSSEC_RESULT_INVALID, dnssec_result_non_authenticated = _DNSSEC_RESULT_INVALID; + DnsTransaction *t; Iterator i; + int r; assert(q); - assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); - - /* Note that this call might invalidate the query. Callers - * should hence not attempt to access the query or transaction - * after calling this function, unless the block_ready - * counter was explicitly bumped before doing so. */ - if (q->block_ready > 0) + if (!c) { + dns_query_synthesize_reply(q, &state); + dns_query_complete(q, state); return; + } - SET_FOREACH(t, q->transactions, i) { - - /* If we found a successful answer, ignore all answers from other scopes */ - if (state == DNS_TRANSACTION_SUCCESS && t->scope != scope) - continue; - - /* One of the transactions is still going on, let's maybe wait for it */ - if (IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) { - pending = true; - continue; - } + SET_FOREACH(t, c->transactions, i) { - /* One of the transactions is successful, let's use - * it, and copy its data out */ - if (t->state == DNS_TRANSACTION_SUCCESS) { - DnsAnswer *a; + switch (t->state) { - if (t->received) { - rcode = DNS_PACKET_RCODE(t->received); - a = t->received->answer; - } else { - rcode = t->cached_rcode; - a = t->cached; + case DNS_TRANSACTION_SUCCESS: { + /* We found a successfuly reply, merge it into the answer */ + r = dns_answer_extend(&q->answer, t->answer); + if (r < 0) { + dns_query_complete(q, DNS_TRANSACTION_RESOURCES); + return; } - if (state == DNS_TRANSACTION_SUCCESS) { - DnsAnswer *merged; + q->answer_rcode = t->answer_rcode; - merged = dns_answer_merge(answer, a); - if (!merged) { - dns_query_complete(q, DNS_TRANSACTION_RESOURCES); - return; - } - - dns_answer_unref(answer); - answer = merged; + if (t->answer_authenticated) { + has_authenticated = true; + dnssec_result_authenticated = t->answer_dnssec_result; } else { - dns_answer_unref(answer); - answer = dns_answer_ref(a); + has_non_authenticated = true; + dnssec_result_non_authenticated = t->answer_dnssec_result; } - scope = t->scope; state = DNS_TRANSACTION_SUCCESS; - continue; + break; } - /* One of the transactions has failed, let's see - * whether we find anything better, but if not, return - * its response data */ - if (state != DNS_TRANSACTION_SUCCESS && t->state == DNS_TRANSACTION_FAILURE) { - DnsAnswer *a; + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + case DNS_TRANSACTION_ABORTED: + /* Ignore transactions that didn't complete */ + continue; - if (t->received) { - rcode = DNS_PACKET_RCODE(t->received); - a = t->received->answer; - } else { - rcode = t->cached_rcode; - a = t->cached; - } + default: + /* Any kind of failure? Store the data away, + * if there's nothing stored yet. */ - dns_answer_unref(answer); - answer = dns_answer_ref(a); + if (state == DNS_TRANSACTION_SUCCESS) + continue; - scope = t->scope; - state = DNS_TRANSACTION_FAILURE; - continue; - } + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = t->answer_rcode; + q->answer_dnssec_result = t->answer_dnssec_result; - if (state == DNS_TRANSACTION_NO_SERVERS && t->state != DNS_TRANSACTION_NO_SERVERS) state = t->state; + break; + } + } + + if (state == DNS_TRANSACTION_SUCCESS) { + q->answer_authenticated = has_authenticated && !has_non_authenticated; + q->answer_dnssec_result = q->answer_authenticated ? dnssec_result_authenticated : dnssec_result_non_authenticated; } - if (pending) { + q->answer_protocol = c->scope->protocol; + q->answer_family = c->scope->family; - /* If so far we weren't successful, and there's - * something still pending, then wait for it */ - if (state != DNS_TRANSACTION_SUCCESS) + dns_search_domain_unref(q->answer_search_domain); + q->answer_search_domain = dns_search_domain_ref(c->search_domain); + + dns_query_synthesize_reply(q, &state); + dns_query_complete(q, state); +} + +void dns_query_ready(DnsQuery *q) { + + DnsQueryCandidate *bad = NULL, *c; + bool pending = false; + + assert(q); + assert(DNS_TRANSACTION_IS_LIVE(q->state)); + + /* Note that this call might invalidate the query. Callers + * should hence not attempt to access the query or transaction + * after calling this function, unless the block_ready + * counter was explicitly bumped before doing so. */ + + if (q->block_ready > 0) + return; + + LIST_FOREACH(candidates_by_query, c, q->candidates) { + DnsTransactionState state; + + state = dns_query_candidate_state(c); + switch (state) { + + case DNS_TRANSACTION_SUCCESS: + /* One of the candidates is successful, + * let's use it, and copy its data out */ + dns_query_accept(q, c); return; - /* If we already were successful, then only wait for - * other transactions on the same scope to finish. */ - SET_FOREACH(t, q->transactions, i) { - if (t->scope == scope && IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) - return; - } - } + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* One of the candidates is still going on, + * let's maybe wait for it */ + pending = true; + break; - if (IN_SET(state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE)) { - q->answer = dns_answer_ref(answer); - q->answer_rcode = rcode; - q->answer_protocol = scope ? scope->protocol : _DNS_PROTOCOL_INVALID; - q->answer_family = scope ? scope->family : AF_UNSPEC; + default: + /* Any kind of failure */ + bad = c; + break; + } } - /* Try to synthesize a reply if we couldn't resolve something. */ - dns_query_synthesize_reply(q, &state); + if (pending) + return; - dns_query_complete(q, state); + dns_query_accept(q, bad); } -int dns_query_cname_redirect(DnsQuery *q, const char *name) { - _cleanup_(dns_question_unrefp) DnsQuestion *nq = NULL; - int r; +static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) { + _cleanup_(dns_question_unrefp) DnsQuestion *nq_idna = NULL, *nq_utf8 = NULL; + int r, k; assert(q); + q->n_cname_redirects ++; if (q->n_cname_redirects > CNAME_MAX) return -ELOOP; - r = dns_question_cname_redirect(q->question, name, &nq); + r = dns_question_cname_redirect(q->question_idna, cname, &nq_idna); if (r < 0) return r; + else if (r > 0) + log_debug("Following CNAME/DNAME %s → %s.", dns_question_first_name(q->question_idna), dns_question_first_name(nq_idna)); - dns_question_unref(q->question); - q->question = nq; - nq = NULL; + k = dns_question_is_equal(q->question_idna, q->question_utf8); + if (k < 0) + return r; + if (k > 0) { + /* Same question? Shortcut new question generation */ + nq_utf8 = dns_question_ref(nq_idna); + k = r; + } else { + k = dns_question_cname_redirect(q->question_utf8, cname, &nq_utf8); + if (k < 0) + return k; + else if (k > 0) + log_debug("Following UTF8 CNAME/DNAME %s → %s.", dns_question_first_name(q->question_utf8), dns_question_first_name(nq_utf8)); + } - q->n_cname_redirects++; + if (r == 0 && k == 0) /* No actual cname happened? */ + return -ELOOP; - dns_query_stop(q); + dns_question_unref(q->question_idna); + q->question_idna = nq_idna; + nq_idna = NULL; + + dns_question_unref(q->question_utf8); + q->question_utf8 = nq_utf8; + nq_utf8 = NULL; + + dns_query_free_candidates(q); + dns_query_reset_answer(q); q->state = DNS_TRANSACTION_NULL; + /* Turn off searching for the new name */ + q->flags |= SD_RESOLVED_NO_SEARCH; + return 0; } +int dns_query_process_cname(DnsQuery *q) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL; + DnsQuestion *question; + DnsResourceRecord *rr; + int r; + + assert(q); + + if (!IN_SET(q->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NULL)) + return DNS_QUERY_NOMATCH; + + question = dns_query_question_for_protocol(q, q->answer_protocol); + + DNS_ANSWER_FOREACH(rr, q->answer) { + r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + if (r < 0) + return r; + if (r > 0) + return DNS_QUERY_MATCH; /* The answer matches directly, no need to follow cnames */ + + r = dns_question_matches_cname_or_dname(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + if (r < 0) + return r; + if (r > 0 && !cname) + cname = dns_resource_record_ref(rr); + } + + if (!cname) + return DNS_QUERY_NOMATCH; /* No match and no cname to follow */ + + if (q->flags & SD_RESOLVED_NO_CNAME) + return -ELOOP; + + /* OK, let's actually follow the CNAME */ + r = dns_query_cname_redirect(q, cname); + if (r < 0) + return r; + + /* Let's see if the answer can already answer the new + * redirected question */ + r = dns_query_process_cname(q); + if (r != DNS_QUERY_NOMATCH) + return r; + + /* OK, it cannot, let's begin with the new query */ + r = dns_query_go(q); + if (r < 0) + return r; + + return DNS_QUERY_RESTARTED; /* We restarted the query for a new cname */ +} + static int on_bus_track(sd_bus_track *t, void *userdata) { DnsQuery *q = userdata; @@ -885,3 +1329,42 @@ int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) { return 0; } + +DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol) { + assert(q); + + switch (protocol) { + + case DNS_PROTOCOL_DNS: + return q->question_idna; + + case DNS_PROTOCOL_MDNS: + case DNS_PROTOCOL_LLMNR: + return q->question_utf8; + + default: + return NULL; + } +} + +const char *dns_query_string(DnsQuery *q) { + const char *name; + int r; + + /* Returns a somewhat useful human-readable lookup key string for this query */ + + if (q->request_address_string) + return q->request_address_string; + + if (q->request_address_valid) { + r = in_addr_to_string(q->request_family, &q->request_address, &q->request_address_string); + if (r >= 0) + return q->request_address_string; + } + + name = dns_question_first_name(q->question_utf8); + if (name) + return name; + + return dns_question_first_name(q->question_idna); +} diff --git a/src/resolve/resolved-dns-query.h b/src/resolve/resolved-dns-query.h index 93d49301fa..9f618d6f6b 100644 --- a/src/resolve/resolved-dns-query.h +++ b/src/resolve/resolved-dns-query.h @@ -23,17 +23,48 @@ #include "sd-bus.h" + #include "set.h" +typedef struct DnsQueryCandidate DnsQueryCandidate; typedef struct DnsQuery DnsQuery; -#include "resolved-dns-question.h" #include "resolved-dns-answer.h" +#include "resolved-dns-question.h" #include "resolved-dns-stream.h" +#include "resolved-dns-search-domain.h" + +struct DnsQueryCandidate { + DnsQuery *query; + DnsScope *scope; + + DnsSearchDomain *search_domain; + + int error_code; + Set *transactions; + + LIST_FIELDS(DnsQueryCandidate, candidates_by_query); + LIST_FIELDS(DnsQueryCandidate, candidates_by_scope); +}; struct DnsQuery { Manager *manager; - DnsQuestion *question; + + /* When resolving a service, we first create a TXT+SRV query, + * and then for the hostnames we discover auxiliary A+AAAA + * queries. This pointer always points from the auxiliary + * queries back to the TXT+SRV query. */ + DnsQuery *auxiliary_for; + LIST_HEAD(DnsQuery, auxiliary_queries); + unsigned n_auxiliary_queries; + int auxiliary_result; + + /* The question, formatted in IDNA for use on classic DNS, and as UTF8 for use in LLMNR or mDNS. Note that even + * on classic DNS some labels might use UTF8 encoding. Specifically, DNS-SD service names (in contrast to their + * domain suffixes) use UTF-8 encoding even on DNS. Thus, the difference between these two fields is mostly + * relevant only for explicit *hostname* lookups as well as the domain suffixes of service lookups. */ + DnsQuestion *question_idna; + DnsQuestion *question_utf8; uint64_t flags; int ifindex; @@ -41,39 +72,59 @@ struct DnsQuery { DnsTransactionState state; unsigned n_cname_redirects; + LIST_HEAD(DnsQueryCandidate, candidates); sd_event_source *timeout_event_source; /* Discovered data */ DnsAnswer *answer; - int answer_family; - DnsProtocol answer_protocol; int answer_rcode; + DnssecResult answer_dnssec_result; + bool answer_authenticated; + DnsProtocol answer_protocol; + int answer_family; + DnsSearchDomain *answer_search_domain; /* Bus client information */ sd_bus_message *request; int request_family; - const char *request_hostname; + bool request_address_valid; union in_addr_union request_address; + unsigned block_all_complete; + char *request_address_string; /* Completion callback */ void (*complete)(DnsQuery* q); unsigned block_ready; - Set *transactions; - sd_bus_track *bus_track; LIST_FIELDS(DnsQuery, queries); + LIST_FIELDS(DnsQuery, auxiliary_queries); }; -int dns_query_new(Manager *m, DnsQuery **q, DnsQuestion *question, int family, uint64_t flags); +enum { + DNS_QUERY_MATCH, + DNS_QUERY_NOMATCH, + DNS_QUERY_RESTARTED, +}; + +DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c); +void dns_query_candidate_notify(DnsQueryCandidate *c); + +int dns_query_new(Manager *m, DnsQuery **q, DnsQuestion *question_utf8, DnsQuestion *question_idna, int family, uint64_t flags); DnsQuery *dns_query_free(DnsQuery *q); +int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for); + int dns_query_go(DnsQuery *q); void dns_query_ready(DnsQuery *q); -int dns_query_cname_redirect(DnsQuery *q, const char *name); +int dns_query_process_cname(DnsQuery *q); int dns_query_bus_track(DnsQuery *q, sd_bus_message *m); +DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol); + +const char *dns_query_string(DnsQuery *q); + DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free); diff --git a/src/resolve/resolved-dns-question.c b/src/resolve/resolved-dns-question.c index c94928d725..1e41a9aa3c 100644 --- a/src/resolve/resolved-dns-question.c +++ b/src/resolve/resolved-dns-question.c @@ -19,8 +19,10 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "resolved-dns-question.h" +#include "alloc-util.h" #include "dns-domain.h" +#include "dns-type.h" +#include "resolved-dns-question.h" DnsQuestion *dns_question_new(unsigned n) { DnsQuestion *q; @@ -88,7 +90,7 @@ int dns_question_add(DnsQuestion *q, DnsResourceKey *key) { return 0; } -int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr) { +int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { unsigned i; int r; @@ -98,7 +100,7 @@ int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr) { return 0; for (i = 0; i < q->n_keys; i++) { - r = dns_resource_key_match_rr(q->keys[i], rr); + r = dns_resource_key_match_rr(q->keys[i], rr, search_domain); if (r != 0) return r; } @@ -106,7 +108,7 @@ int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr) { return 0; } -int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *rr) { +int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { unsigned i; int r; @@ -115,8 +117,15 @@ int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *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++) { - r = dns_resource_key_match_cname(q->keys[i], rr); + /* 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; } @@ -124,7 +133,7 @@ int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *rr) { return 0; } -int dns_question_is_valid(DnsQuestion *q) { +int dns_question_is_valid_for_query(DnsQuestion *q) { const char *name; unsigned i; int r; @@ -143,62 +152,23 @@ int dns_question_is_valid(DnsQuestion *q) { return 0; /* Check that all keys in this question bear the same name */ - for (i = 1; i < q->n_keys; i++) { + for (i = 0; i < q->n_keys; i++) { assert(q->keys[i]); - r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name); - if (r <= 0) - return r; - } - - return 1; -} - -int dns_question_is_superset(DnsQuestion *q, DnsQuestion *other) { - unsigned j; - int r; - - /* Checks if all keys in "other" are also contained in "q" */ - - if (!other) - return 1; - - for (j = 0; j < other->n_keys; j++) { - DnsResourceKey *b = other->keys[j]; - bool found = false; - unsigned i; - - if (!q) - return 0; - - for (i = 0; i < q->n_keys; i++) { - DnsResourceKey *a = q->keys[i]; - - r = dns_name_equal(DNS_RESOURCE_KEY_NAME(a), DNS_RESOURCE_KEY_NAME(b)); - if (r < 0) + if (i > 0) { + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name); + if (r <= 0) return r; - - if (r == 0) - continue; - - if (a->class != b->class && a->class != DNS_CLASS_ANY) - continue; - - if (a->type != b->type && a->type != DNS_TYPE_ANY) - continue; - - found = true; - break; } - if (!found) + if (!dns_type_is_valid_query(q->keys[i]->type)) return 0; } return 1; } -int dns_question_contains(DnsQuestion *a, DnsResourceKey *k) { +int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) { unsigned j; int r; @@ -220,6 +190,9 @@ 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) @@ -242,27 +215,38 @@ int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { return 1; } -int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion **ret) { +int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; + DnsResourceKey *key; bool same = true; - unsigned i; int r; - assert(name); + assert(cname); assert(ret); + assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); - if (!q) { - n = dns_question_new(0); - if (!n) - return -ENOMEM; - - *ret = n; - n = 0; + if (dns_question_size(q) <= 0) { + *ret = NULL; return 0; } - for (i = 0; i < q->n_keys; i++) { - r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name); + 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; @@ -272,9 +256,9 @@ int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion ** } } + /* Fully the same, indicate we didn't do a thing */ if (same) { - /* Shortcut, the names are already right */ - *ret = dns_question_ref(q); + *ret = NULL; return 0; } @@ -283,10 +267,10 @@ int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion ** return -ENOMEM; /* Create a new question, and patch in the new name */ - for (i = 0; i < q->n_keys; i++) { + DNS_QUESTION_FOREACH(key, q) { _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; - k = dns_resource_key_new(q->keys[i]->class, q->keys[i]->type, name); + k = dns_resource_key_new_redirect(key, cname); if (!k) return -ENOMEM; @@ -300,3 +284,187 @@ int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion ** 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/resolve/resolved-dns-question.h b/src/resolve/resolved-dns-question.h index 77de0c7a2c..98e1f0e366 100644 --- a/src/resolve/resolved-dns-question.h +++ b/src/resolve/resolved-dns-question.h @@ -23,9 +23,10 @@ typedef struct DnsQuestion DnsQuestion; +#include "macro.h" #include "resolved-dns-rr.h" -/* A simple array of resources keys */ +/* A simple array of resource keys */ struct DnsQuestion { unsigned n_ref; @@ -37,15 +38,34 @@ DnsQuestion *dns_question_new(unsigned n); DnsQuestion *dns_question_ref(DnsQuestion *q); DnsQuestion *dns_question_unref(DnsQuestion *q); +int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna); +int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a); +int dns_question_new_service(DnsQuestion **ret, const char *service, const char *type, const char *domain, bool with_txt, bool convert_idna); + int dns_question_add(DnsQuestion *q, DnsResourceKey *key); -int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr); -int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *rr); -int dns_question_is_valid(DnsQuestion *q); -int dns_question_is_superset(DnsQuestion *q, DnsQuestion *other); -int dns_question_contains(DnsQuestion *a, DnsResourceKey *k); +int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain); +int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char* search_domain); +int dns_question_is_valid_for_query(DnsQuestion *q); +int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k); int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b); -int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion **ret); +int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret); + +const char *dns_question_first_name(DnsQuestion *q); + +static inline unsigned dns_question_size(DnsQuestion *q) { + return q ? q->n_keys : 0; +} DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuestion*, dns_question_unref); + +#define _DNS_QUESTION_FOREACH(u, key, q) \ + for (unsigned UNIQ_T(i, u) = ({ \ + (key) = ((q) && (q)->n_keys > 0) ? (q)->keys[0] : NULL; \ + 0; \ + }); \ + (q) && (UNIQ_T(i, u) < (q)->n_keys); \ + UNIQ_T(i, u)++, (key) = (UNIQ_T(i, u) < (q)->n_keys ? (q)->keys[UNIQ_T(i, u)] : NULL)) + +#define DNS_QUESTION_FOREACH(key, q) _DNS_QUESTION_FOREACH(UNIQ, key, q) diff --git a/src/resolve/resolved-dns-rr.c b/src/resolve/resolved-dns-rr.c index f31644eebc..7273ef3825 100644 --- a/src/resolve/resolved-dns-rr.c +++ b/src/resolve/resolved-dns-rr.c @@ -21,12 +21,15 @@ #include <math.h> -#include "strv.h" - +#include "alloc-util.h" #include "dns-domain.h" -#include "resolved-dns-rr.h" -#include "resolved-dns-packet.h" #include "dns-type.h" +#include "hexdecoct.h" +#include "resolved-dns-packet.h" +#include "resolved-dns-rr.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name) { DnsResourceKey *k; @@ -48,6 +51,64 @@ DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char * 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; @@ -70,6 +131,10 @@ 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++; @@ -80,6 +145,7 @@ 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) { @@ -91,9 +157,20 @@ DnsResourceKey* dns_resource_key_unref(DnsResourceKey *k) { return NULL; } +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; @@ -107,41 +184,100 @@ int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b) { return 1; } -int dns_resource_key_match_rr(const DnsResourceKey *key, const DnsResourceRecord *rr) { +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; - return dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key)); + 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(const DnsResourceKey *key, const DnsResourceRecord *rr) { +int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain) { + int r; + assert(key); - assert(rr); + assert(cname); - if (rr->key->class != key->class && key->class != DNS_CLASS_ANY) + if (cname->class != key->class && key->class != DNS_CLASS_ANY) return 0; - if (rr->key->type != DNS_TYPE_CNAME) + 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; - return 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; + + 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; } -static unsigned long dns_resource_key_hash_func(const void *i, const uint8_t hash_key[HASH_KEY_SIZE]) { +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; - unsigned long ul; - ul = dns_name_hash_func(DNS_RESOURCE_KEY_NAME(k), hash_key); - ul = ul * hash_key[0] + ul + k->class; - ul = ul * hash_key[1] + ul + k->type; + assert(k); - return ul; + 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) { @@ -172,9 +308,12 @@ const struct hash_ops dns_resource_key_hash_ops = { int dns_resource_key_to_string(const DnsResourceKey *key, char **ret) { char cbuf[strlen("CLASS") + DECIMAL_STR_MAX(uint16_t)], tbuf[strlen("TYPE") + DECIMAL_STR_MAX(uint16_t)]; - const char *c, *t; + const char *c, *t, *n; char *s; + /* 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); if (!c) { sprintf(cbuf, "CLASS%u", key->class); @@ -187,13 +326,54 @@ int dns_resource_key_to_string(const DnsResourceKey *key, char **ret) { t = tbuf; } - if (asprintf(&s, "%s %s %-5s", DNS_RESOURCE_KEY_NAME(key), c, t) < 0) + n = DNS_RESOURCE_KEY_NAME(key); + if (asprintf(&s, "%s%s %s %-5s", n, endswith(n, ".") ? "" : ".", c, t) < 0) return -ENOMEM; *ret = s; return 0; } +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; @@ -203,6 +383,8 @@ DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key) { 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; } @@ -259,7 +441,7 @@ DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) { case DNS_TYPE_TXT: case DNS_TYPE_SPF: - strv_free(rr->txt.strings); + dns_txt_item_free_all(rr->txt.items); break; case DNS_TYPE_SOA: @@ -308,9 +490,11 @@ DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) { free(rr->generic.data); } + free(rr->wire_format); dns_resource_key_unref(rr->key); } + free(rr->to_string); free(rr); return NULL; @@ -386,6 +570,9 @@ int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecor assert(a); assert(b); + if (a == b) + return 1; + r = dns_resource_key_equal(a->key, b->key); if (r <= 0) return r; @@ -416,7 +603,7 @@ int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecor case DNS_TYPE_SPF: /* exactly the same as TXT */ case DNS_TYPE_TXT: - return strv_equal(a->txt.strings, b->txt.strings); + 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; @@ -468,8 +655,8 @@ int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecor memcmp(a->sshfp.fingerprint, b->sshfp.fingerprint, a->sshfp.fingerprint_size) == 0; case DNS_TYPE_DNSKEY: - return a->dnskey.zone_key_flag == b->dnskey.zone_key_flag && - a->dnskey.sep_flag == b->dnskey.sep_flag && + return a->dnskey.flags == b->dnskey.flags && + a->dnskey.protocol == b->dnskey.protocol && a->dnskey.algorithm == b->dnskey.algorithm && a->dnskey.key_size == b->dnskey.key_size && memcmp(a->dnskey.key, b->dnskey.key, a->dnskey.key_size) == 0; @@ -586,16 +773,56 @@ static char *format_types(Bitmap *types) { return strjoin("( ", str, " )", NULL); } -int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { +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 *k = NULL, *t = NULL; char *s; int r; assert(rr); + if (rr->to_string) + return rr->to_string; + r = dns_resource_key_to_string(rr->key, &k); if (r < 0) - return r; + return NULL; switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) { @@ -607,7 +834,7 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->srv.port, strna(rr->srv.name)); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_PTR: @@ -616,26 +843,25 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { case DNS_TYPE_DNAME: s = strjoin(k, " ", rr->ptr.name, NULL); if (!s) - return -ENOMEM; + return NULL; break; case DNS_TYPE_HINFO: s = strjoin(k, " ", rr->hinfo.cpu, " ", rr->hinfo.os, NULL); if (!s) - return -ENOMEM; + return NULL; break; case DNS_TYPE_SPF: /* exactly the same as TXT */ case DNS_TYPE_TXT: - t = strv_join_quoted(rr->txt.strings); + t = format_txt(rr->txt.items); if (!t) - return -ENOMEM; + return NULL; s = strjoin(k, " ", t, NULL); if (!s) - return -ENOMEM; - + return NULL; break; case DNS_TYPE_A: { @@ -643,22 +869,22 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { r = in_addr_to_string(AF_INET, (const union in_addr_union*) &rr->a.in_addr, &x); if (r < 0) - return r; + return NULL; s = strjoin(k, " ", x, NULL); if (!s) - return -ENOMEM; + 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 r; + return NULL; s = strjoin(k, " ", t, NULL); if (!s) - return -ENOMEM; + return NULL; break; case DNS_TYPE_SOA: @@ -672,7 +898,7 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->soa.expire, rr->soa.minimum); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_MX: @@ -681,7 +907,7 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->mx.priority, rr->mx.exchange); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_LOC: @@ -694,17 +920,17 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->loc.horiz_pre, rr->loc.vert_pre); if (!t) - return -ENOMEM; + return NULL; s = strjoin(k, " ", t, NULL); if (!s) - return -ENOMEM; + return NULL; break; case DNS_TYPE_DS: t = hexmem(rr->ds.digest, rr->ds.digest_size); if (!t) - return -ENOMEM; + return NULL; r = asprintf(&s, "%s %u %u %u %s", k, @@ -713,13 +939,13 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->ds.digest_type, t); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_SSHFP: t = hexmem(rr->sshfp.fingerprint, rr->sshfp.fingerprint_size); if (!t) - return -ENOMEM; + return NULL; r = asprintf(&s, "%s %u %u %s", k, @@ -727,57 +953,62 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->sshfp.fptype, t); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_DNSKEY: { - const char *alg; + _cleanup_free_ char *alg = NULL; - alg = dnssec_algorithm_to_string(rr->dnskey.algorithm); + r = dnssec_algorithm_to_string_alloc(rr->dnskey.algorithm, &alg); + if (r < 0) + return NULL; t = base64mem(rr->dnskey.key, rr->dnskey.key_size); if (!t) - return -ENOMEM; + return NULL; - r = asprintf(&s, "%s %u 3 %.*s%.*u %s", + r = asprintf(&s, "%s %u %u %s %s", k, - dnskey_to_flags(rr), - alg ? -1 : 0, alg, - alg ? 0 : 1, alg ? 0u : (unsigned) rr->dnskey.algorithm, + rr->dnskey.flags, + rr->dnskey.protocol, + alg, t); if (r < 0) - return -ENOMEM; + return NULL; break; } case DNS_TYPE_RRSIG: { - const char *type, *alg; + _cleanup_free_ char *alg = NULL; char expiration[strlen("YYYYMMDDHHmmSS") + 1], inception[strlen("YYYYMMDDHHmmSS") + 1]; + const char *type; type = dns_type_to_string(rr->rrsig.type_covered); - alg = dnssec_algorithm_to_string(rr->rrsig.algorithm); + + r = dnssec_algorithm_to_string_alloc(rr->rrsig.algorithm, &alg); + if (r < 0) + return NULL; t = base64mem(rr->rrsig.signature, rr->rrsig.signature_size); if (!t) - return -ENOMEM; + return NULL; r = format_timestamp_dns(expiration, sizeof(expiration), rr->rrsig.expiration); if (r < 0) - return r; + return NULL; r = format_timestamp_dns(inception, sizeof(inception), rr->rrsig.inception); if (r < 0) - return r; + return NULL; /* TYPE?? follows * http://tools.ietf.org/html/rfc3597#section-5 */ - r = asprintf(&s, "%s %s%.*u %.*s%.*u %u %u %s %s %u %s %s", + r = asprintf(&s, "%s %s%.*u %s %u %u %s %s %u %s %s", k, type ?: "TYPE", type ? 0 : 1, type ? 0u : (unsigned) rr->rrsig.type_covered, - alg ? -1 : 0, alg, - alg ? 0 : 1, alg ? 0u : (unsigned) rr->rrsig.algorithm, + alg, rr->rrsig.labels, rr->rrsig.original_ttl, expiration, @@ -786,21 +1017,21 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { rr->rrsig.signer, t); if (r < 0) - return -ENOMEM; + return NULL; break; } case DNS_TYPE_NSEC: t = format_types(rr->nsec.types); if (!t) - return -ENOMEM; + return NULL; r = asprintf(&s, "%s %s %s", k, rr->nsec.next_domain_name, t); if (r < 0) - return -ENOMEM; + return NULL; break; case DNS_TYPE_NSEC3: { @@ -809,16 +1040,16 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { if (rr->nsec3.salt_size > 0) { salt = hexmem(rr->nsec3.salt, rr->nsec3.salt_size); if (!salt) - return -ENOMEM; + return NULL; } hash = base32hexmem(rr->nsec3.next_hashed_name, rr->nsec3.next_hashed_name_size, false); if (!hash) - return -ENOMEM; + return NULL; t = format_types(rr->nsec3.types); if (!t) - return -ENOMEM; + return NULL; r = asprintf(&s, "%s %"PRIu8" %"PRIu8" %"PRIu16" %s %s %s", k, @@ -829,7 +1060,7 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { hash, t); if (r < 0) - return -ENOMEM; + return NULL; break; } @@ -837,42 +1068,354 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) { default: t = hexmem(rr->generic.data, rr->generic.size); if (!t) - return -ENOMEM; + return NULL; + /* Format as documented in RFC 3597, Section 5 */ r = asprintf(&s, "%s \\# %zu %s", k, rr->generic.size, t); if (r < 0) - return -ENOMEM; + return NULL; break; } - *ret = s; + rr->to_string = s; + return s; +} + +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; } -const char *dns_class_to_string(uint16_t class) { +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; - switch (class) { + assert(rr); + assert(ret); - case DNS_CLASS_IN: - return "IN"; + /* Returns the RRset's signer, if it is known. */ - case DNS_CLASS_ANY: - return "ANY"; - } + if (rr->n_skip_labels_signer == (unsigned) -1) + return -ENODATA; - return NULL; + 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_class_from_string(const char *s, uint16_t *class) { - assert(s); - assert(class); +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret) { + const char *n; + int r; - if (strcaseeq(s, "IN")) - *class = DNS_CLASS_IN; - else if (strcaseeq(s, "ANY")) - *class = DNS_CLASS_ANY; - else + 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; +} + +static 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; + + default: + siphash24_compress(rr->generic.data, rr->generic.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 odering, 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, +}; + +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); +} + +static const char* const dnssec_algorithm_table[_DNSSEC_ALGORITHM_MAX_DEFINED] = { + /* Mnemonics as listed on https://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ + [DNSSEC_ALGORITHM_RSAMD5] = "RSAMD5", + [DNSSEC_ALGORITHM_DH] = "DH", + [DNSSEC_ALGORITHM_DSA] = "DSA", + [DNSSEC_ALGORITHM_ECC] = "ECC", + [DNSSEC_ALGORITHM_RSASHA1] = "RSASHA1", + [DNSSEC_ALGORITHM_DSA_NSEC3_SHA1] = "DSA-NSEC3-SHA1", + [DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1] = "RSASHA1-NSEC3-SHA1", + [DNSSEC_ALGORITHM_RSASHA256] = "RSASHA256", + [DNSSEC_ALGORITHM_RSASHA512] = "RSASHA512", + [DNSSEC_ALGORITHM_ECC_GOST] = "ECC-GOST", + [DNSSEC_ALGORITHM_ECDSAP256SHA256] = "ECDSAP256SHA256", + [DNSSEC_ALGORITHM_ECDSAP384SHA384] = "ECDSAP384SHA384", + [DNSSEC_ALGORITHM_INDIRECT] = "INDIRECT", + [DNSSEC_ALGORITHM_PRIVATEDNS] = "PRIVATEDNS", + [DNSSEC_ALGORITHM_PRIVATEOID] = "PRIVATEOID", +}; +DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(dnssec_algorithm, int, 255); + +static const char* const dnssec_digest_table[_DNSSEC_DIGEST_MAX_DEFINED] = { + /* Names as listed on https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ + [DNSSEC_DIGEST_SHA1] = "SHA-1", + [DNSSEC_DIGEST_SHA256] = "SHA-256", + [DNSSEC_DIGEST_GOST_R_34_11_94] = "GOST_R_34.11-94", + [DNSSEC_DIGEST_SHA384] = "SHA-384", +}; +DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(dnssec_digest, int, 255); diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h index 8986a298af..d9c31e81c5 100644 --- a/src/resolve/resolved-dns-rr.h +++ b/src/resolve/resolved-dns-rr.h @@ -24,37 +24,113 @@ #include <netinet/in.h> #include "bitmap.h" +#include "dns-type.h" #include "hashmap.h" #include "in-addr-util.h" -#include "dns-type.h" +#include "list.h" typedef struct DnsResourceKey DnsResourceKey; typedef struct DnsResourceRecord DnsResourceRecord; +typedef struct DnsTxtItem DnsTxtItem; + +/* DNSKEY RR flags */ +#define DNSKEY_FLAG_SEP (UINT16_C(1) << 0) +#define DNSKEY_FLAG_REVOKE (UINT16_C(1) << 7) +#define DNSKEY_FLAG_ZONE_KEY (UINT16_C(1) << 8) + +/* mDNS RR flags */ +#define MDNS_RR_CACHE_FLUSH (UINT16_C(1) << 15) + +/* DNSSEC algorithm identifiers, see + * http://tools.ietf.org/html/rfc4034#appendix-A.1 and + * https://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ +enum { + DNSSEC_ALGORITHM_RSAMD5 = 1, + DNSSEC_ALGORITHM_DH, + DNSSEC_ALGORITHM_DSA, + DNSSEC_ALGORITHM_ECC, + DNSSEC_ALGORITHM_RSASHA1, + DNSSEC_ALGORITHM_DSA_NSEC3_SHA1, + DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1, + DNSSEC_ALGORITHM_RSASHA256 = 8, /* RFC 5702 */ + DNSSEC_ALGORITHM_RSASHA512 = 10, /* RFC 5702 */ + DNSSEC_ALGORITHM_ECC_GOST = 12, /* RFC 5933 */ + DNSSEC_ALGORITHM_ECDSAP256SHA256 = 13, /* RFC 6605 */ + DNSSEC_ALGORITHM_ECDSAP384SHA384 = 14, /* RFC 6605 */ + DNSSEC_ALGORITHM_INDIRECT = 252, + DNSSEC_ALGORITHM_PRIVATEDNS, + DNSSEC_ALGORITHM_PRIVATEOID, + _DNSSEC_ALGORITHM_MAX_DEFINED +}; -/* DNS record classes, see RFC 1035 */ +/* DNSSEC digest identifiers, see + * https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ enum { - DNS_CLASS_IN = 0x01, - DNS_CLASS_ANY = 0xFF, - _DNS_CLASS_MAX, - _DNS_CLASS_INVALID = -1 + DNSSEC_DIGEST_SHA1 = 1, + DNSSEC_DIGEST_SHA256 = 2, /* RFC 4509 */ + DNSSEC_DIGEST_GOST_R_34_11_94 = 3, /* RFC 5933 */ + DNSSEC_DIGEST_SHA384 = 4, /* RFC 6605 */ + _DNSSEC_DIGEST_MAX_DEFINED +}; + +/* DNSSEC NSEC3 hash algorithms, see + * https://www.iana.org/assignments/dnssec-nsec3-parameters/dnssec-nsec3-parameters.xhtml */ +enum { + NSEC3_ALGORITHM_SHA1 = 1, + _NSEC3_ALGORITHM_MAX_DEFINED }; struct DnsResourceKey { - unsigned n_ref; + unsigned n_ref; /* (unsigned -1) for const keys, see below */ uint16_t class, type; char *_name; /* don't access directy, use DNS_RESOURCE_KEY_NAME()! */ }; +/* Creates a temporary resource key. This is only useful to quickly + * look up something, without allocating a full DnsResourceKey object + * for it. Note that it is not OK to take references to this kind of + * resource key object. */ +#define DNS_RESOURCE_KEY_CONST(c, t, n) \ + ((DnsResourceKey) { \ + .n_ref = (unsigned) -1, \ + .class = c, \ + .type = t, \ + ._name = (char*) n, \ + }) + + +struct DnsTxtItem { + size_t length; + LIST_FIELDS(DnsTxtItem, items); + uint8_t data[]; +}; + struct DnsResourceRecord { unsigned n_ref; DnsResourceKey *key; + + char *to_string; + uint32_t ttl; - bool unparseable; + usec_t expiry; /* RRSIG signature expiry */ + + /* How many labels to strip to determine "signer" of the RRSIG (aka, the zone). -1 if not signed. */ + unsigned n_skip_labels_signer; + /* How many labels to strip to determine "synthesizing source" of this RR, i.e. the wildcard's immediate parent. -1 if not signed. */ + unsigned n_skip_labels_source; + + bool unparseable:1; + + bool wire_format_canonical:1; + void *wire_format; + size_t wire_format_size; + size_t wire_format_rdata_offset; + union { struct { void *data; size_t size; - } generic; + } generic, opt; struct { uint16_t priority; @@ -73,7 +149,7 @@ struct DnsResourceRecord { } hinfo; struct { - char **strings; + DnsTxtItem *items; } txt, spf; struct { @@ -99,6 +175,7 @@ struct DnsResourceRecord { char *exchange; } mx; + /* https://tools.ietf.org/html/rfc1876 */ struct { uint8_t version; uint8_t size; @@ -109,14 +186,6 @@ struct DnsResourceRecord { uint32_t altitude; } loc; - struct { - uint16_t key_tag; - uint8_t algorithm; - uint8_t digest_type; - void *digest; - size_t digest_size; - } ds; - /* https://tools.ietf.org/html/rfc4255#section-3.1 */ struct { uint8_t algorithm; @@ -127,8 +196,8 @@ struct DnsResourceRecord { /* http://tools.ietf.org/html/rfc4034#section-2.1 */ struct { - bool zone_key_flag:1; - bool sep_flag:1; + uint16_t flags; + uint8_t protocol; uint8_t algorithm; void* key; size_t key_size; @@ -148,11 +217,21 @@ struct DnsResourceRecord { size_t signature_size; } rrsig; + /* https://tools.ietf.org/html/rfc4034#section-4.1 */ struct { char *next_domain_name; Bitmap *types; } nsec; + /* https://tools.ietf.org/html/rfc4034#section-5.1 */ + struct { + uint16_t key_tag; + uint8_t algorithm; + uint8_t digest_type; + void *digest; + size_t digest_size; + } ds; + struct { uint8_t algorithm; uint8_t flags; @@ -167,7 +246,7 @@ struct DnsResourceRecord { }; static inline const char* DNS_RESOURCE_KEY_NAME(const DnsResourceKey *key) { - if (_unlikely_(!key)) + if (!key) return NULL; if (key->_name) @@ -176,16 +255,47 @@ static inline const char* DNS_RESOURCE_KEY_NAME(const DnsResourceKey *key) { return (char*) key + sizeof(DnsResourceKey); } +static inline const void* DNS_RESOURCE_RECORD_RDATA(DnsResourceRecord *rr) { + if (!rr) + return NULL; + + if (!rr->wire_format) + return NULL; + + assert(rr->wire_format_rdata_offset <= rr->wire_format_size); + return (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset; +} + +static inline size_t DNS_RESOURCE_RECORD_RDATA_SIZE(DnsResourceRecord *rr) { + if (!rr) + return 0; + if (!rr->wire_format) + return 0; + + assert(rr->wire_format_rdata_offset <= rr->wire_format_size); + return rr->wire_format_size - rr->wire_format_rdata_offset; +} + DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name); +DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname); +int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name); DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name); DnsResourceKey* dns_resource_key_ref(DnsResourceKey *key); DnsResourceKey* dns_resource_key_unref(DnsResourceKey *key); +bool dns_resource_key_is_address(const DnsResourceKey *key); int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b); -int dns_resource_key_match_rr(const DnsResourceKey *key, const DnsResourceRecord *rr); -int dns_resource_key_match_cname(const DnsResourceKey *key, const DnsResourceRecord *rr); +int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain); +int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain); +int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa); int dns_resource_key_to_string(const DnsResourceKey *key, char **ret); DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref); +static inline bool dns_key_is_shared(const DnsResourceKey *key) { + return IN_SET(key->type, DNS_TYPE_PTR); +} + +bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b); + DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key); DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name); DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr); @@ -193,10 +303,24 @@ DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr); int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name); int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name); int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b); -int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret); +const char* dns_resource_record_to_string(DnsResourceRecord *rr); DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref); -const char *dns_class_to_string(uint16_t type); -int dns_class_from_string(const char *name, uint16_t *class); +int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical); + +int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_source(DnsResourceRecord *rr, const char **ret); +int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone); +int dns_resource_record_is_synthetic(DnsResourceRecord *rr); + +DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i); +bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b); extern const struct hash_ops dns_resource_key_hash_ops; +extern const struct hash_ops dns_resource_record_hash_ops; + +int dnssec_algorithm_to_string_alloc(int i, char **ret); +int dnssec_algorithm_from_string(const char *s) _pure_; + +int dnssec_digest_to_string_alloc(int i, char **ret); +int dnssec_digest_from_string(const char *s) _pure_; diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index 9e6f595a1b..8a52d66fad 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -21,15 +21,18 @@ #include <netinet/tcp.h> -#include "missing.h" -#include "strv.h" -#include "socket-util.h" #include "af-list.h" -#include "random-util.h" -#include "hostname-util.h" +#include "alloc-util.h" #include "dns-domain.h" -#include "resolved-llmnr.h" +#include "fd-util.h" +#include "hostname-util.h" +#include "missing.h" +#include "random-util.h" #include "resolved-dns-scope.h" +#include "resolved-llmnr.h" +#include "resolved-mdns.h" +#include "socket-util.h" +#include "strv.h" #define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) #define MULTICAST_RATELIMIT_BURST 1000 @@ -54,9 +57,25 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int s->family = family; s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC; + s->dnssec_mode = _DNSSEC_MODE_INVALID; + + if (protocol == DNS_PROTOCOL_DNS) { + /* Copy DNSSEC mode from the link if it is set there, + * otherwise take the manager's DNSSEC mode. Note that + * we copy this only at scope creation time, and do + * not update it from the on, even if the setting + * changes. */ + + if (l) + s->dnssec_mode = link_get_dnssec_mode(l); + else + s->dnssec_mode = manager_get_dnssec_mode(m); + } + LIST_PREPEND(scopes, m->dns_scopes, s); dns_scope_llmnr_membership(s, true); + dns_scope_mdns_membership(s, true); log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family)); @@ -67,29 +86,40 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int return 0; } -DnsScope* dns_scope_free(DnsScope *s) { - DnsTransaction *t; - DnsResourceRecord *rr; - - if (!s) - return NULL; - - log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family)); +static void dns_scope_abort_transactions(DnsScope *s) { + assert(s); - dns_scope_llmnr_membership(s, false); + while (s->transactions) { + DnsTransaction *t = s->transactions; - while ((t = hashmap_steal_first(s->transactions))) { /* Abort the transaction, but make sure it is not * freed while we still look at it */ t->block_gc++; - dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); + if (DNS_TRANSACTION_IS_LIVE(t->state)) + dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); t->block_gc--; dns_transaction_free(t); } +} + +DnsScope* dns_scope_free(DnsScope *s) { + DnsResourceRecord *rr; - hashmap_free(s->transactions); + if (!s) + return NULL; + + log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family)); + + dns_scope_llmnr_membership(s, false); + dns_scope_mdns_membership(s, false); + dns_scope_abort_transactions(s); + + while (s->query_candidates) + dns_query_candidate_free(s->query_candidates); + + hashmap_free(s->transactions_by_key); while ((rr = ordered_hashmap_steal_first(s->conflict_queue))) dns_resource_record_unref(rr); @@ -101,7 +131,6 @@ DnsScope* dns_scope_free(DnsScope *s) { dns_zone_flush(&s->zone); LIST_REMOVE(scopes, s->manager->dns_scopes, s); - strv_free(s->domains); free(s); return NULL; @@ -134,11 +163,11 @@ void dns_scope_next_dns_server(DnsScope *s) { void dns_scope_packet_received(DnsScope *s, usec_t rtt) { assert(s); - if (rtt > s->max_rtt) { - s->max_rtt = rtt; - s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), - MULTICAST_RESEND_TIMEOUT_MAX_USEC); - } + if (rtt <= s->max_rtt) + return; + + s->max_rtt = rtt; + s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); } void dns_scope_packet_lost(DnsScope *s, usec_t usec) { @@ -148,17 +177,15 @@ void dns_scope_packet_lost(DnsScope *s, usec_t usec) { s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); } -int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { +static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { union in_addr_union addr; int ifindex = 0, r; int family; - uint16_t port; uint32_t mtu; assert(s); assert(p); assert(p->protocol == s->protocol); - assert((s->protocol == DNS_PROTOCOL_DNS) != (fd < 0)); if (s->link) { mtu = s->link->mtu; @@ -167,7 +194,10 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { mtu = manager_find_mtu(s->manager); switch (s->protocol) { + case DNS_PROTOCOL_DNS: + assert(fd >= 0); + if (DNS_PACKET_QDCOUNT(p) > 1) return -EOPNOTSUPP; @@ -184,6 +214,8 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { break; case DNS_PROTOCOL_LLMNR: + assert(fd < 0); + if (DNS_PACKET_QDCOUNT(p) > 1) return -EOPNOTSUPP; @@ -191,7 +223,6 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { return -EBUSY; family = s->family; - port = LLMNR_PORT; if (family == AF_INET) { addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; @@ -204,7 +235,32 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { if (fd < 0) return fd; - r = manager_send(s->manager, fd, ifindex, family, &addr, port, p); + r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, p); + if (r < 0) + return r; + + break; + + case DNS_PROTOCOL_MDNS: + assert(fd < 0); + + if (!ratelimit_test(&s->ratelimit)) + return -EBUSY; + + family = s->family; + + if (family == AF_INET) { + addr.in = MDNS_MULTICAST_IPV4_ADDRESS; + fd = manager_mdns_ipv4_fd(s->manager); + } else if (family == AF_INET6) { + addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; + fd = manager_mdns_ipv6_fd(s->manager); + } else + return -EAFNOSUPPORT; + if (fd < 0) + return fd; + + r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, p); if (r < 0) return r; @@ -217,8 +273,39 @@ int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p) { return 1; } -static int dns_scope_socket(DnsScope *s, int type, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) { - DnsServer *srv = NULL; +int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { + int r; + + assert(s); + assert(p); + assert(p->protocol == s->protocol); + assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); + + do { + /* If there are multiple linked packets, set the TC bit in all but the last of them */ + if (p->more) { + assert(p->protocol == DNS_PROTOCOL_MDNS); + dns_packet_set_flags(p, true, true); + } + + r = dns_scope_emit_one(s, fd, p); + if (r < 0) + return r; + + p = p->more; + } while (p); + + return 0; +} + +static int dns_scope_socket( + DnsScope *s, + int type, + int family, + const union in_addr_union *address, + DnsServer *server, + uint16_t port) { + _cleanup_close_ int fd = -1; union sockaddr_union sa = {}; socklen_t salen; @@ -226,26 +313,27 @@ static int dns_scope_socket(DnsScope *s, int type, int family, const union in_ad int ret, r; assert(s); - assert((family == AF_UNSPEC) == !address); - if (family == AF_UNSPEC) { - srv = dns_scope_get_dns_server(s); - if (!srv) - return -ESRCH; + if (server) { + assert(family == AF_UNSPEC); + assert(!address); - sa.sa.sa_family = srv->family; - if (srv->family == AF_INET) { + sa.sa.sa_family = server->family; + if (server->family == AF_INET) { sa.in.sin_port = htobe16(port); - sa.in.sin_addr = srv->address.in; + sa.in.sin_addr = server->address.in; salen = sizeof(sa.in); - } else if (srv->family == AF_INET6) { + } else if (server->family == AF_INET6) { sa.in6.sin6_port = htobe16(port); - sa.in6.sin6_addr = srv->address.in6; + sa.in6.sin6_addr = server->address.in6; sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0; salen = sizeof(sa.in6); } else return -EAFNOSUPPORT; } else { + assert(family != AF_UNSPEC); + assert(address); + sa.sa.sa_family = family; if (family == AF_INET) { @@ -303,36 +391,34 @@ static int dns_scope_socket(DnsScope *s, int type, int family, const union in_ad if (r < 0 && errno != EINPROGRESS) return -errno; - if (server) - *server = srv; - ret = fd; fd = -1; return ret; } -int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server) { - return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, 53, server); +int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) { + return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port); } -int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) { - return dns_scope_socket(s, SOCK_STREAM, family, address, port, server); +int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) { + return dns_scope_socket(s, SOCK_STREAM, family, address, server, port); } DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) { - char **i; + DnsSearchDomain *d; assert(s); assert(domain); - if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) - return DNS_SCOPE_NO; + /* Checks if the specified domain is something to look up on + * this scope. Note that this accepts non-qualified hostnames, + * i.e. those without any search path prefixed yet. */ - if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family) & flags) == 0) + if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) return DNS_SCOPE_NO; - if (dns_name_root(domain) != 0) + if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) return DNS_SCOPE_NO; /* Never resolve any loopback hostname or IP address via DNS, @@ -343,15 +429,38 @@ DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, co dns_name_equal(domain, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) return DNS_SCOPE_NO; - STRV_FOREACH(i, s->domains) - if (dns_name_endswith(domain, *i) > 0) + /* Never respond to some of the domains listed in RFC6303 */ + if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || + dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || + dns_name_equal(domain, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) + return DNS_SCOPE_NO; + + /* Never respond to some of the domains listed in RFC6761 */ + if (dns_name_endswith(domain, "invalid") > 0) + return DNS_SCOPE_NO; + + /* Always honour search domains for routing queries. Note that + * we return DNS_SCOPE_YES here, rather than just + * DNS_SCOPE_MAYBE, which means wildcard scopes won't be + * considered anymore. */ + LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) + if (dns_name_endswith(domain, d->name) > 0) return DNS_SCOPE_YES; switch (s->protocol) { + case DNS_PROTOCOL_DNS: + + /* Exclude link-local IP ranges */ if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && - dns_name_endswith(domain, "0.8.e.f.ip6.arpa") == 0 && - dns_name_single_label(domain) == 0) + dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && + dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && + /* If networks use .local in their private setups, they are supposed to also add .local to their search + * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't + * send such queries ordinary DNS servers. */ + dns_name_endswith(domain, "local") == 0) return DNS_SCOPE_MAYBE; return DNS_SCOPE_NO; @@ -369,7 +478,7 @@ DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, co case DNS_PROTOCOL_LLMNR: if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || - (dns_name_single_label(domain) > 0 && /* only resolve single label names via LLMNR */ + (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ return DNS_SCOPE_MAYBE; @@ -385,8 +494,27 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) { assert(s); assert(key); - if (s->protocol == DNS_PROTOCOL_DNS) - return true; + /* Check if it makes sense to resolve the specified key on + * this scope. Note that this call assumes as fully qualified + * name, i.e. the search suffixes already appended. */ + + if (s->protocol == DNS_PROTOCOL_DNS) { + + /* On classic DNS, looking up non-address RRs is always + * fine. (Specifically, we want to permit looking up + * DNSKEY and DS records on the root and top-level + * domains.) */ + if (!dns_resource_key_is_address(key)) + return true; + + /* However, we refuse to look up A and AAAA RRs on the + * root and single-label domains, under the assumption + * that those should be resolved via LLMNR or search + * path only, and should not be leaked onto the + * internet. */ + return !(dns_name_is_single_label(DNS_RESOURCE_KEY_NAME(key)) || + dns_name_is_root(DNS_RESOURCE_KEY_NAME(key))); + } /* On mDNS and LLMNR, send A and AAAA queries only on the * respective scopes */ @@ -400,19 +528,15 @@ int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) { return true; } -int dns_scope_llmnr_membership(DnsScope *s, bool b) { +static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { int fd; assert(s); - - if (s->protocol != DNS_PROTOCOL_LLMNR) - return 0; - assert(s->link); if (s->family == AF_INET) { struct ip_mreqn mreqn = { - .imr_multiaddr = LLMNR_MULTICAST_IPV4_ADDRESS, + .imr_multiaddr = in, .imr_ifindex = s->link->ifindex, }; @@ -431,7 +555,7 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) { } else if (s->family == AF_INET6) { struct ipv6_mreq mreq = { - .ipv6mr_multiaddr = LLMNR_MULTICAST_IPV6_ADDRESS, + .ipv6mr_multiaddr = in6, .ipv6mr_interface = s->link->ifindex, }; @@ -450,6 +574,22 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) { return 0; } +int dns_scope_llmnr_membership(DnsScope *s, bool b) { + + if (s->protocol != DNS_PROTOCOL_LLMNR) + return 0; + + return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); +} + +int dns_scope_mdns_membership(DnsScope *s, bool b) { + + if (s->protocol != DNS_PROTOCOL_MDNS) + return 0; + + return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); +} + static int dns_scope_make_reply_packet( DnsScope *s, uint16_t id, @@ -500,7 +640,7 @@ static int dns_scope_make_reply_packet( if (answer) { for (i = 0; i < answer->n_rrs; i++) { - r = dns_packet_append_rr(p, answer->items[i].rr, NULL); + r = dns_packet_append_rr(p, answer->items[i].rr, NULL, NULL); if (r < 0) return r; } @@ -510,7 +650,7 @@ static int dns_scope_make_reply_packet( if (soa) { for (i = 0; i < soa->n_rrs; i++) { - r = dns_packet_append_rr(p, soa->items[i].rr, NULL); + r = dns_packet_append_rr(p, soa->items[i].rr, NULL, NULL); if (r < 0) return r; } @@ -541,6 +681,7 @@ static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; + DnsResourceKey *key = NULL; bool tentative = false; int r, fd; @@ -574,7 +715,10 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { return; } - r = dns_zone_lookup(&s->zone, p->question, &answer, &soa, &tentative); + assert(p->question->n_keys == 1); + key = p->question->keys[0]; + + r = dns_zone_lookup(&s->zone, key, &answer, &soa, &tentative); if (r < 0) { log_debug_errno(r, "Failed to lookup key: %m"); return; @@ -632,15 +776,15 @@ DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, /* Try to find an ongoing transaction that is a equal to the * specified question */ - t = hashmap_get(scope->transactions, key); + t = hashmap_get(scope->transactions_by_key, key); if (!t) return NULL; /* Refuse reusing transactions that completed based on cached * data instead of a real packet, if that's requested. */ if (!cache_ok && - IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE) && - !t->received) + IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && + t->answer_source != DNS_TRANSACTION_NETWORK) return NULL; return t; @@ -672,7 +816,11 @@ static int dns_scope_make_conflict_packet( 0 /* (ad) */, 0 /* (cd) */, 0)); - random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); + + /* For mDNS, the transaction ID should always be 0 */ + if (s->protocol != DNS_PROTOCOL_MDNS) + random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); + DNS_PACKET_HEADER(p)->qdcount = htobe16(1); DNS_PACKET_HEADER(p)->arcount = htobe16(1); @@ -680,7 +828,7 @@ static int dns_scope_make_conflict_packet( if (r < 0) return r; - r = dns_packet_append_rr(p, rr, NULL); + r = dns_packet_append_rr(p, rr, NULL, NULL); if (r < 0) return r; @@ -713,7 +861,7 @@ static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata return 0; } - r = dns_scope_emit(scope, -1, p); + r = dns_scope_emit_udp(scope, -1, p); if (r < 0) log_debug_errno(r, "Failed to send conflict packet: %m"); } @@ -762,6 +910,8 @@ int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) { if (r < 0) return log_debug_errno(r, "Failed to add conflict dispatch event: %m"); + (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict"); + return 0; } @@ -844,3 +994,24 @@ void dns_scope_dump(DnsScope *s, FILE *f) { dns_cache_dump(&s->cache, f); } } + +DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return NULL; + + if (s->link) + return s->link->search_domains; + + return s->manager->search_domains; +} + +bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) { + assert(s); + + if (s->protocol != DNS_PROTOCOL_DNS) + return false; + + return dns_name_is_single_label(name); +} diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h index b75f212897..a0676bd30e 100644 --- a/src/resolve/resolved-dns-scope.h +++ b/src/resolve/resolved-dns-scope.h @@ -25,9 +25,10 @@ typedef struct DnsScope DnsScope; -#include "resolved-dns-server.h" -#include "resolved-dns-packet.h" #include "resolved-dns-cache.h" +#include "resolved-dns-dnssec.h" +#include "resolved-dns-packet.h" +#include "resolved-dns-server.h" #include "resolved-dns-zone.h" #include "resolved-link.h" @@ -44,11 +45,10 @@ struct DnsScope { DnsProtocol protocol; int family; + DnssecMode dnssec_mode; Link *link; - char **domains; - DnsCache cache; DnsZone zone; @@ -60,7 +60,18 @@ struct DnsScope { usec_t resend_timeout; usec_t max_rtt; - Hashmap *transactions; + LIST_HEAD(DnsQueryCandidate, query_candidates); + + /* Note that we keep track of ongoing transactions in two + * ways: once in a hashmap, indexed by the rr key, and once in + * a linked list. We use the hashmap to quickly find + * transactions we can reuse for a key. But note that there + * might be multiple transactions for the same key (because + * the zone probing can't reuse a transaction answered from + * the zone or the cache), and the hashmap only tracks the + * most recent entry. */ + Hashmap *transactions_by_key; + LIST_HEAD(DnsTransaction, transactions); LIST_FIELDS(DnsScope, scopes); }; @@ -71,9 +82,9 @@ DnsScope* dns_scope_free(DnsScope *s); void dns_scope_packet_received(DnsScope *s, usec_t rtt); void dns_scope_packet_lost(DnsScope *s, usec_t usec); -int dns_scope_emit(DnsScope *s, int fd, DnsPacket *p); -int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server); -int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server); +int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p); +int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port); +int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port); DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain); int dns_scope_good_key(DnsScope *s, DnsResourceKey *key); @@ -82,6 +93,7 @@ DnsServer *dns_scope_get_dns_server(DnsScope *s); void dns_scope_next_dns_server(DnsScope *s); int dns_scope_llmnr_membership(DnsScope *s, bool b); +int dns_scope_mdns_membership(DnsScope *s, bool b); void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p); @@ -91,3 +103,7 @@ int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr); void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p); void dns_scope_dump(DnsScope *s, FILE *f); + +DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s); + +bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name); diff --git a/src/resolve/resolved-dns-search-domain.c b/src/resolve/resolved-dns-search-domain.c new file mode 100644 index 0000000000..f9d966abb1 --- /dev/null +++ b/src/resolve/resolved-dns-search-domain.c @@ -0,0 +1,232 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "alloc-util.h" +#include "dns-domain.h" +#include "resolved-dns-search-domain.h" + +int dns_search_domain_new( + Manager *m, + DnsSearchDomain **ret, + DnsSearchDomainType type, + Link *l, + const char *name) { + + _cleanup_free_ char *normalized = NULL; + DnsSearchDomain *d; + int r; + + assert(m); + assert((type == DNS_SEARCH_DOMAIN_LINK) == !!l); + assert(name); + + r = dns_name_normalize(name, &normalized); + if (r < 0) + return r; + + if (dns_name_is_root(normalized)) + return -EINVAL; + + if (l) { + if (l->n_search_domains >= LINK_SEARCH_DOMAINS_MAX) + return -E2BIG; + } else { + if (m->n_search_domains >= MANAGER_SEARCH_DOMAINS_MAX) + return -E2BIG; + } + + d = new0(DnsSearchDomain, 1); + if (!d) + return -ENOMEM; + + d->n_ref = 1; + d->manager = m; + d->type = type; + d->name = normalized; + normalized = NULL; + + switch (type) { + + case DNS_SEARCH_DOMAIN_LINK: + d->link = l; + LIST_APPEND(domains, l->search_domains, d); + l->n_search_domains++; + break; + + case DNS_SERVER_SYSTEM: + LIST_APPEND(domains, m->search_domains, d); + m->n_search_domains++; + break; + + default: + assert_not_reached("Unknown search domain type"); + } + + d->linked = true; + + if (ret) + *ret = d; + + return 0; +} + +DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d) { + if (!d) + return NULL; + + assert(d->n_ref > 0); + d->n_ref++; + + return d; +} + +DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d) { + if (!d) + return NULL; + + assert(d->n_ref > 0); + d->n_ref--; + + if (d->n_ref > 0) + return NULL; + + free(d->name); + free(d); + + return NULL; +} + +void dns_search_domain_unlink(DnsSearchDomain *d) { + assert(d); + assert(d->manager); + + if (!d->linked) + return; + + switch (d->type) { + + case DNS_SEARCH_DOMAIN_LINK: + assert(d->link); + assert(d->link->n_search_domains > 0); + LIST_REMOVE(domains, d->link->search_domains, d); + d->link->n_search_domains--; + break; + + case DNS_SEARCH_DOMAIN_SYSTEM: + assert(d->manager->n_search_domains > 0); + LIST_REMOVE(domains, d->manager->search_domains, d); + d->manager->n_search_domains--; + break; + } + + d->linked = false; + + dns_search_domain_unref(d); +} + +void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d) { + DnsSearchDomain *tail; + + assert(d); + + if (!d->marked) + return; + + d->marked = false; + + if (!d->linked || !d->domains_next) + return; + + switch (d->type) { + + case DNS_SEARCH_DOMAIN_LINK: + assert(d->link); + LIST_FIND_TAIL(domains, d, tail); + LIST_REMOVE(domains, d->link->search_domains, d); + LIST_INSERT_AFTER(domains, d->link->search_domains, tail, d); + break; + + case DNS_SEARCH_DOMAIN_SYSTEM: + LIST_FIND_TAIL(domains, d, tail); + LIST_REMOVE(domains, d->manager->search_domains, d); + LIST_INSERT_AFTER(domains, d->manager->search_domains, tail, d); + break; + + default: + assert_not_reached("Unknown search domain type"); + } +} + +void dns_search_domain_unlink_all(DnsSearchDomain *first) { + DnsSearchDomain *next; + + if (!first) + return; + + next = first->domains_next; + dns_search_domain_unlink(first); + + dns_search_domain_unlink_all(next); +} + +void dns_search_domain_unlink_marked(DnsSearchDomain *first) { + DnsSearchDomain *next; + + if (!first) + return; + + next = first->domains_next; + + if (first->marked) + dns_search_domain_unlink(first); + + dns_search_domain_unlink_marked(next); +} + +void dns_search_domain_mark_all(DnsSearchDomain *first) { + if (!first) + return; + + first->marked = true; + dns_search_domain_mark_all(first->domains_next); +} + +int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret) { + DnsSearchDomain *d; + int r; + + assert(name); + assert(ret); + + LIST_FOREACH(domains, d, first) { + + r = dns_name_equal(name, d->name); + if (r < 0) + return r; + if (r > 0) { + *ret = d; + return 1; + } + } + + *ret = NULL; + return 0; +} diff --git a/src/resolve/resolved-dns-search-domain.h b/src/resolve/resolved-dns-search-domain.h new file mode 100644 index 0000000000..2e0af31dda --- /dev/null +++ b/src/resolve/resolved-dns-search-domain.h @@ -0,0 +1,75 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "macro.h" + +typedef struct DnsSearchDomain DnsSearchDomain; + +typedef enum DnsSearchDomainType { + DNS_SEARCH_DOMAIN_SYSTEM, + DNS_SEARCH_DOMAIN_LINK, +} DnsSearchDomainType; + +#include "resolved-link.h" +#include "resolved-manager.h" + +struct DnsSearchDomain { + Manager *manager; + + unsigned n_ref; + + DnsSearchDomainType type; + Link *link; + + char *name; + + bool marked:1; + + bool linked:1; + LIST_FIELDS(DnsSearchDomain, domains); +}; + +int dns_search_domain_new( + Manager *m, + DnsSearchDomain **ret, + DnsSearchDomainType type, + Link *link, + const char *name); + +DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d); +DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d); + +void dns_search_domain_unlink(DnsSearchDomain *d); +void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d); + +void dns_search_domain_unlink_all(DnsSearchDomain *first); +void dns_search_domain_unlink_marked(DnsSearchDomain *first); +void dns_search_domain_mark_all(DnsSearchDomain *first); + +int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret); + +static inline const char* DNS_SEARCH_DOMAIN_NAME(DnsSearchDomain *d) { + return d ? d->name : NULL; +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(DnsSearchDomain*, dns_search_domain_unref); diff --git a/src/resolve/resolved-dns-server.c b/src/resolve/resolved-dns-server.c index 2ff5b192df..5a86661807 100644 --- a/src/resolve/resolved-dns-server.c +++ b/src/resolve/resolved-dns-server.c @@ -19,14 +19,24 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "siphash24.h" - +#include "alloc-util.h" #include "resolved-dns-server.h" +#include "resolved-resolv-conf.h" +#include "siphash24.h" +#include "string-table.h" +#include "string-util.h" /* After how much time to repeat classic DNS requests */ #define DNS_TIMEOUT_MIN_USEC (500 * USEC_PER_MSEC) #define DNS_TIMEOUT_MAX_USEC (5 * USEC_PER_SEC) +/* The amount of time to wait before retrying with a full feature set */ +#define DNS_SERVER_FEATURE_GRACE_PERIOD_MAX_USEC (6 * USEC_PER_HOUR) +#define DNS_SERVER_FEATURE_GRACE_PERIOD_MIN_USEC (5 * USEC_PER_MINUTE) + +/* The number of times we will attempt a certain feature set before degrading */ +#define DNS_SERVER_FEATURE_RETRY_ATTEMPTS 3 + int dns_server_new( Manager *m, DnsServer **ret, @@ -35,36 +45,61 @@ int dns_server_new( int family, const union in_addr_union *in_addr) { - DnsServer *s, *tail; + DnsServer *s; assert(m); assert((type == DNS_SERVER_LINK) == !!l); assert(in_addr); + if (!IN_SET(family, AF_INET, AF_INET6)) + return -EAFNOSUPPORT; + + if (l) { + if (l->n_dns_servers >= LINK_DNS_SERVERS_MAX) + return -E2BIG; + } else { + if (m->n_dns_servers >= MANAGER_DNS_SERVERS_MAX) + return -E2BIG; + } + s = new0(DnsServer, 1); if (!s) return -ENOMEM; s->n_ref = 1; + s->manager = m; + s->verified_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_BEST; + s->features_grace_period_usec = DNS_SERVER_FEATURE_GRACE_PERIOD_MIN_USEC; + s->received_udp_packet_max = DNS_PACKET_UNICAST_SIZE_MAX; s->type = type; s->family = family; s->address = *in_addr; s->resend_timeout = DNS_TIMEOUT_MIN_USEC; - if (type == DNS_SERVER_LINK) { - LIST_FIND_TAIL(servers, l->dns_servers, tail); - LIST_INSERT_AFTER(servers, l->dns_servers, tail, s); + switch (type) { + + case DNS_SERVER_LINK: s->link = l; - } else if (type == DNS_SERVER_SYSTEM) { - LIST_FIND_TAIL(servers, m->dns_servers, tail); - LIST_INSERT_AFTER(servers, m->dns_servers, tail, s); - } else if (type == DNS_SERVER_FALLBACK) { - LIST_FIND_TAIL(servers, m->fallback_dns_servers, tail); - LIST_INSERT_AFTER(servers, m->fallback_dns_servers, tail, s); - } else + LIST_APPEND(servers, l->dns_servers, s); + l->n_dns_servers++; + break; + + case DNS_SERVER_SYSTEM: + LIST_APPEND(servers, m->dns_servers, s); + m->n_dns_servers++; + break; + + case DNS_SERVER_FALLBACK: + LIST_APPEND(servers, m->fallback_dns_servers, s); + m->n_dns_servers++; + break; + + default: assert_not_reached("Unknown server type"); + } - s->manager = m; + s->linked = true; /* A new DNS server that isn't fallback is added and the one * we used so far was a fallback one? Then let's try to pick @@ -85,66 +120,440 @@ DnsServer* dns_server_ref(DnsServer *s) { return NULL; assert(s->n_ref > 0); - s->n_ref ++; return s; } -static DnsServer* dns_server_free(DnsServer *s) { +DnsServer* dns_server_unref(DnsServer *s) { if (!s) return NULL; + assert(s->n_ref > 0); + s->n_ref --; + + if (s->n_ref > 0) + return NULL; + + free(s->server_string); + free(s); + return NULL; +} + +void dns_server_unlink(DnsServer *s) { + assert(s); + assert(s->manager); + + /* This removes the specified server from the linked list of + * servers, but any server might still stay around if it has + * refs, for example from an ongoing transaction. */ + + if (!s->linked) + return; + + switch (s->type) { + + case DNS_SERVER_LINK: + assert(s->link); + assert(s->link->n_dns_servers > 0); + LIST_REMOVE(servers, s->link->dns_servers, s); + break; + + case DNS_SERVER_SYSTEM: + assert(s->manager->n_dns_servers > 0); + LIST_REMOVE(servers, s->manager->dns_servers, s); + s->manager->n_dns_servers--; + break; + + case DNS_SERVER_FALLBACK: + assert(s->manager->n_dns_servers > 0); + LIST_REMOVE(servers, s->manager->fallback_dns_servers, s); + s->manager->n_dns_servers--; + break; + } + + s->linked = false; + if (s->link && s->link->current_dns_server == s) link_set_dns_server(s->link, NULL); - if (s->manager && s->manager->current_dns_server == s) + if (s->manager->current_dns_server == s) manager_set_dns_server(s->manager, NULL); - free(s); + dns_server_unref(s); +} - return NULL; +void dns_server_move_back_and_unmark(DnsServer *s) { + DnsServer *tail; + + assert(s); + + if (!s->marked) + return; + + s->marked = false; + + if (!s->linked || !s->servers_next) + return; + + /* Move us to the end of the list, so that the order is + * strictly kept, if we are not at the end anyway. */ + + switch (s->type) { + + case DNS_SERVER_LINK: + assert(s->link); + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->link->dns_servers, s); + LIST_INSERT_AFTER(servers, s->link->dns_servers, tail, s); + break; + + case DNS_SERVER_SYSTEM: + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->manager->dns_servers, s); + LIST_INSERT_AFTER(servers, s->manager->dns_servers, tail, s); + break; + + case DNS_SERVER_FALLBACK: + LIST_FIND_TAIL(servers, s, tail); + LIST_REMOVE(servers, s->manager->fallback_dns_servers, s); + LIST_INSERT_AFTER(servers, s->manager->fallback_dns_servers, tail, s); + break; + + default: + assert_not_reached("Unknown server type"); + } } -DnsServer* dns_server_unref(DnsServer *s) { - if (!s) - return NULL; +static void dns_server_verified(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); - assert(s->n_ref > 0); + if (s->verified_feature_level > level) + return; - if (s->n_ref == 1) - dns_server_free(s); - else - s->n_ref --; + if (s->verified_feature_level != level) { + log_debug("Verified we get a response at feature level %s from DNS server %s.", + dns_server_feature_level_to_string(level), + dns_server_string(s)); + s->verified_feature_level = level; + } - return NULL; + assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &s->verified_usec) >= 0); } -void dns_server_packet_received(DnsServer *s, usec_t rtt) { +void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t rtt, size_t size) { assert(s); - if (rtt > s->max_rtt) { + if (protocol == IPPROTO_UDP) { + if (s->possible_feature_level == level) + s->n_failed_udp = 0; + + /* If the RRSIG data is missing, then we can only validate EDNS0 at max */ + if (s->packet_rrsig_missing && level >= DNS_SERVER_FEATURE_LEVEL_DO) + level = DNS_SERVER_FEATURE_LEVEL_DO - 1; + + /* If the OPT RR got lost, then we can only validate UDP at max */ + if (s->packet_bad_opt && level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) + level = DNS_SERVER_FEATURE_LEVEL_EDNS0 - 1; + + /* Even if we successfully receive a reply to a request announcing support for large packets, + that does not mean we can necessarily receive large packets. */ + if (level == DNS_SERVER_FEATURE_LEVEL_LARGE) + level = DNS_SERVER_FEATURE_LEVEL_LARGE - 1; + + } else if (protocol == IPPROTO_TCP) { + + if (s->possible_feature_level == level) + s->n_failed_tcp = 0; + + /* Successful TCP connections are only useful to verify the TCP feature level. */ + level = DNS_SERVER_FEATURE_LEVEL_TCP; + } + + dns_server_verified(s, level); + + /* Remember the size of the largest UDP packet we received from a server, + we know that we can always announce support for packets with at least + this size. */ + if (protocol == IPPROTO_UDP && s->received_udp_packet_max < size) + s->received_udp_packet_max = size; + + if (s->max_rtt < rtt) { s->max_rtt = rtt; - s->resend_timeout = MIN(MAX(DNS_TIMEOUT_MIN_USEC, s->max_rtt * 2), - DNS_TIMEOUT_MAX_USEC); + s->resend_timeout = CLAMP(s->max_rtt * 2, DNS_TIMEOUT_MIN_USEC, DNS_TIMEOUT_MAX_USEC); + } +} + +void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t usec) { + assert(s); + assert(s->manager); + + if (s->possible_feature_level == level) { + if (protocol == IPPROTO_UDP) + s->n_failed_udp ++; + else if (protocol == IPPROTO_TCP) + s->n_failed_tcp ++; } + + if (s->resend_timeout > usec) + return; + + s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC); +} + +void dns_server_packet_failed(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + /* Invoked whenever we get a FORMERR, SERVFAIL or NOTIMP rcode from a server. */ + + if (s->possible_feature_level != level) + return; + + s->packet_failed = true; +} + +void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + /* Invoked whenever we get a packet with TC bit set. */ + + if (s->possible_feature_level != level) + return; + + s->packet_truncated = true; +} + +void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level) { + assert(s); + + if (level < DNS_SERVER_FEATURE_LEVEL_DO) + return; + + /* If the RRSIG RRs are missing, we have to downgrade what we previously verified */ + if (s->verified_feature_level >= DNS_SERVER_FEATURE_LEVEL_DO) + s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_DO-1; + + s->packet_rrsig_missing = true; } -void dns_server_packet_lost(DnsServer *s, usec_t usec) { +void dns_server_packet_bad_opt(DnsServer *s, DnsServerFeatureLevel level) { assert(s); - if (s->resend_timeout <= usec) - s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC); + if (level < DNS_SERVER_FEATURE_LEVEL_EDNS0) + return; + + /* If the OPT RR got lost, we have to downgrade what we previously verified */ + if (s->verified_feature_level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) + s->verified_feature_level = DNS_SERVER_FEATURE_LEVEL_EDNS0-1; + + s->packet_bad_opt = true; } -static unsigned long dns_server_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { +static bool dns_server_grace_period_expired(DnsServer *s) { + usec_t ts; + + assert(s); + assert(s->manager); + + if (s->verified_usec == 0) + return false; + + assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + if (s->verified_usec + s->features_grace_period_usec > ts) + return false; + + s->features_grace_period_usec = MIN(s->features_grace_period_usec * 2, DNS_SERVER_FEATURE_GRACE_PERIOD_MAX_USEC); + + return true; +} + +static void dns_server_reset_counters(DnsServer *s) { + assert(s); + + s->n_failed_udp = 0; + s->n_failed_tcp = 0; + s->packet_failed = false; + s->packet_truncated = false; + s->verified_usec = 0; + + /* Note that we do not reset s->packet_bad_opt and s->packet_rrsig_missing here. We reset them only when the + * grace period ends, but not when lowering the possible feature level, as a lower level feature level should + * not make RRSIGs appear or OPT appear, but rather make them disappear. If the reappear anyway, then that's + * indication for a differently broken OPT/RRSIG implementation, and we really don't want to support that + * either. + * + * This is particularly important to deal with certain Belkin routers which break OPT for certain lookups (A), + * but pass traffic through for others (AAAA). If we detect the broken behaviour on one lookup we should not + * reenable it for another, because we cannot validate things anyway, given that the RRSIG/OPT data will be + * incomplete. */ +} + +DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) { + assert(s); + + if (s->possible_feature_level != DNS_SERVER_FEATURE_LEVEL_BEST && + dns_server_grace_period_expired(s)) { + + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_BEST; + + dns_server_reset_counters(s); + + s->packet_bad_opt = false; + s->packet_rrsig_missing = false; + + log_info("Grace period over, resuming full feature set (%s) for DNS server %s.", + dns_server_feature_level_to_string(s->possible_feature_level), + dns_server_string(s)); + + } else if (s->possible_feature_level <= s->verified_feature_level) + s->possible_feature_level = s->verified_feature_level; + else { + DnsServerFeatureLevel p = s->possible_feature_level; + + if (s->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->possible_feature_level == DNS_SERVER_FEATURE_LEVEL_TCP) { + + /* We are at the TCP (lowest) level, and we tried a couple of TCP connections, and it didn't + * work. Upgrade back to UDP again. */ + log_debug("Reached maximum number of failed TCP connection attempts, trying UDP again..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_UDP; + + } else if (s->packet_bad_opt && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_EDNS0) { + + /* A reply to one of our EDNS0 queries didn't carry a valid OPT RR, then downgrade to below + * EDNS0 levels. After all, some records generate different responses with and without OPT RR + * in the request. Example: + * https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ + + log_debug("Server doesn't support EDNS(0) properly, downgrading feature level..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_UDP; + + } else if (s->packet_rrsig_missing && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_DO) { + + /* RRSIG data was missing on a EDNS0 packet with DO bit set. This means the server doesn't + * augment responses with DNSSEC RRs. If so, let's better not ask the server for it anymore, + * after all some servers generate different replies depending if an OPT RR is in the query or + * not. */ + + log_debug("Detected server responses lack RRSIG records, downgrading feature level..."); + s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_EDNS0; + + } else if (s->n_failed_udp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->possible_feature_level >= DNS_SERVER_FEATURE_LEVEL_UDP) { + + /* We lost too many UDP packets in a row, and are on a feature level of UDP or higher. If the + * packets are lost, maybe the server cannot parse them, hence downgrading sounds like a good + * idea. We might downgrade all the way down to TCP this way. */ + + log_debug("Lost too many UDP packets, downgrading feature level..."); + s->possible_feature_level--; + + } else if (s->packet_failed && + s->possible_feature_level > DNS_SERVER_FEATURE_LEVEL_UDP) { + + /* We got a failure packet, and are at a feature level above UDP. Note that in this case we + * downgrade no further than UDP, under the assumption that a failure packet indicates an + * incompatible packet contents, but not a problem with the transport. */ + + log_debug("Got server failure, downgrading feature level..."); + s->possible_feature_level--; + + } else if (s->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS && + s->packet_truncated && + s->possible_feature_level > DNS_SERVER_FEATURE_LEVEL_UDP) { + + /* We got too many TCP connection failures in a row, we had at least one truncated packet, and + * are on a feature level above UDP. By downgrading things and getting rid of DNSSEC or EDNS0 + * data we hope to make the packet smaller, so that it still works via UDP given that TCP + * appears not to be a fallback. Note that if we are already at the lowest UDP level, we don't + * go further down, since that's TCP, and TCP failed too often after all. */ + + log_debug("Got too many failed TCP connection failures and truncated UDP packets, downgrading feature level..."); + s->possible_feature_level--; + } + + if (p != s->possible_feature_level) { + + /* We changed the feature level, reset the counting */ + dns_server_reset_counters(s); + + log_warning("Using degraded feature set (%s) for DNS server %s.", + dns_server_feature_level_to_string(s->possible_feature_level), + dns_server_string(s)); + } + } + + return s->possible_feature_level; +} + +int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level) { + size_t packet_size; + bool edns_do; + int r; + + assert(server); + assert(packet); + assert(packet->protocol == DNS_PROTOCOL_DNS); + + /* Fix the OPT field in the packet to match our current feature level. */ + + r = dns_packet_truncate_opt(packet); + if (r < 0) + return r; + + if (level < DNS_SERVER_FEATURE_LEVEL_EDNS0) + return 0; + + edns_do = level >= DNS_SERVER_FEATURE_LEVEL_DO; + + if (level >= DNS_SERVER_FEATURE_LEVEL_LARGE) + packet_size = DNS_PACKET_UNICAST_SIZE_LARGE_MAX; + else + packet_size = server->received_udp_packet_max; + + return dns_packet_append_opt(packet, packet_size, edns_do, NULL); +} + +const char *dns_server_string(DnsServer *server) { + assert(server); + + if (!server->server_string) + (void) in_addr_to_string(server->family, &server->address, &server->server_string); + + return strna(server->server_string); +} + +bool dns_server_dnssec_supported(DnsServer *server) { + assert(server); + + /* Returns whether the server supports DNSSEC according to what we know about it */ + + if (server->possible_feature_level < DNS_SERVER_FEATURE_LEVEL_DO) + return false; + + if (server->packet_bad_opt) + return false; + + if (server->packet_rrsig_missing) + return false; + + /* DNSSEC servers need to support TCP properly (see RFC5966), if they don't, we assume DNSSEC is borked too */ + if (server->n_failed_tcp >= DNS_SERVER_FEATURE_RETRY_ATTEMPTS) + return false; + + return true; +} + +static void dns_server_hash_func(const void *p, struct siphash *state) { const DnsServer *s = p; - uint64_t u; - siphash24((uint8_t*) &u, &s->address, FAMILY_ADDRESS_SIZE(s->family), hash_key); - u = u * hash_key[0] + u + s->family; + assert(s); - return u; + siphash24_compress(&s->family, sizeof(s->family), state); + siphash24_compress(&s->address, FAMILY_ADDRESS_SIZE(s->family), state); } static int dns_server_compare_func(const void *a, const void *b) { @@ -162,3 +571,145 @@ const struct hash_ops dns_server_hash_ops = { .hash = dns_server_hash_func, .compare = dns_server_compare_func }; + +void dns_server_unlink_all(DnsServer *first) { + DnsServer *next; + + if (!first) + return; + + next = first->servers_next; + dns_server_unlink(first); + + dns_server_unlink_all(next); +} + +void dns_server_unlink_marked(DnsServer *first) { + DnsServer *next; + + if (!first) + return; + + next = first->servers_next; + + if (first->marked) + dns_server_unlink(first); + + dns_server_unlink_marked(next); +} + +void dns_server_mark_all(DnsServer *first) { + if (!first) + return; + + first->marked = true; + dns_server_mark_all(first->servers_next); +} + +DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr) { + DnsServer *s; + + LIST_FOREACH(servers, s, first) + if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0) + return s; + + return NULL; +} + +DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t) { + assert(m); + + switch (t) { + + case DNS_SERVER_SYSTEM: + return m->dns_servers; + + case DNS_SERVER_FALLBACK: + return m->fallback_dns_servers; + + default: + return NULL; + } +} + +DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) { + assert(m); + + if (m->current_dns_server == s) + return s; + + if (s) + log_info("Switching to system DNS server %s.", dns_server_string(s)); + + dns_server_unref(m->current_dns_server); + m->current_dns_server = dns_server_ref(s); + + if (m->unicast_scope) + dns_cache_flush(&m->unicast_scope->cache); + + return s; +} + +DnsServer *manager_get_dns_server(Manager *m) { + Link *l; + assert(m); + + /* Try to read updates resolv.conf */ + manager_read_resolv_conf(m); + + /* If no DNS server was chose so far, pick the first one */ + if (!m->current_dns_server) + manager_set_dns_server(m, m->dns_servers); + + if (!m->current_dns_server) { + bool found = false; + Iterator i; + + /* No DNS servers configured, let's see if there are + * any on any links. If not, we use the fallback + * servers */ + + HASHMAP_FOREACH(l, m->links, i) + if (l->dns_servers) { + found = true; + break; + } + + if (!found) + manager_set_dns_server(m, m->fallback_dns_servers); + } + + return m->current_dns_server; +} + +void manager_next_dns_server(Manager *m) { + assert(m); + + /* If there's currently no DNS server set, then the next + * manager_get_dns_server() will find one */ + if (!m->current_dns_server) + return; + + /* Change to the next one, but make sure to follow the linked + * list only if the server is still linked. */ + if (m->current_dns_server->linked && m->current_dns_server->servers_next) { + manager_set_dns_server(m, m->current_dns_server->servers_next); + return; + } + + /* If there was no next one, then start from the beginning of + * the list */ + if (m->current_dns_server->type == DNS_SERVER_FALLBACK) + manager_set_dns_server(m, m->fallback_dns_servers); + else + manager_set_dns_server(m, m->dns_servers); +} + +static const char* const dns_server_feature_level_table[_DNS_SERVER_FEATURE_LEVEL_MAX] = { + [DNS_SERVER_FEATURE_LEVEL_TCP] = "TCP", + [DNS_SERVER_FEATURE_LEVEL_UDP] = "UDP", + [DNS_SERVER_FEATURE_LEVEL_EDNS0] = "UDP+EDNS0", + [DNS_SERVER_FEATURE_LEVEL_DO] = "UDP+EDNS0+DO", + [DNS_SERVER_FEATURE_LEVEL_LARGE] = "UDP+EDNS0+DO+LARGE", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_server_feature_level, DnsServerFeatureLevel); diff --git a/src/resolve/resolved-dns-server.h b/src/resolve/resolved-dns-server.h index 10111fd6bd..02bd3463a7 100644 --- a/src/resolve/resolved-dns-server.h +++ b/src/resolve/resolved-dns-server.h @@ -24,7 +24,6 @@ #include "in-addr-util.h" typedef struct DnsServer DnsServer; -typedef enum DnsServerSource DnsServerSource; typedef enum DnsServerType { DNS_SERVER_SYSTEM, @@ -32,7 +31,24 @@ typedef enum DnsServerType { DNS_SERVER_LINK, } DnsServerType; +typedef enum DnsServerFeatureLevel { + DNS_SERVER_FEATURE_LEVEL_TCP, + DNS_SERVER_FEATURE_LEVEL_UDP, + DNS_SERVER_FEATURE_LEVEL_EDNS0, + DNS_SERVER_FEATURE_LEVEL_DO, + DNS_SERVER_FEATURE_LEVEL_LARGE, + _DNS_SERVER_FEATURE_LEVEL_MAX, + _DNS_SERVER_FEATURE_LEVEL_INVALID = -1 +} DnsServerFeatureLevel; + +#define DNS_SERVER_FEATURE_LEVEL_WORST 0 +#define DNS_SERVER_FEATURE_LEVEL_BEST (_DNS_SERVER_FEATURE_LEVEL_MAX - 1) + +const char* dns_server_feature_level_to_string(int i) _const_; +int dns_server_feature_level_from_string(const char *s) _pure_; + #include "resolved-link.h" +#include "resolved-manager.h" struct DnsServer { Manager *manager; @@ -40,33 +56,80 @@ struct DnsServer { unsigned n_ref; DnsServerType type; - Link *link; int family; union in_addr_union address; + char *server_string; + usec_t resend_timeout; usec_t max_rtt; + DnsServerFeatureLevel verified_feature_level; + DnsServerFeatureLevel possible_feature_level; + + size_t received_udp_packet_max; + + unsigned n_failed_udp; + unsigned n_failed_tcp; + + bool packet_failed:1; + bool packet_truncated:1; + bool packet_bad_opt:1; + bool packet_rrsig_missing:1; + + usec_t verified_usec; + usec_t features_grace_period_usec; + + /* Used when GC'ing old DNS servers when configuration changes. */ bool marked:1; + /* If linked is set, then this server appears in the servers linked list */ + bool linked:1; LIST_FIELDS(DnsServer, servers); }; int dns_server_new( Manager *m, - DnsServer **s, + DnsServer **ret, DnsServerType type, - Link *l, + Link *link, int family, const union in_addr_union *address); DnsServer* dns_server_ref(DnsServer *s); DnsServer* dns_server_unref(DnsServer *s); -void dns_server_packet_received(DnsServer *s, usec_t rtt); -void dns_server_packet_lost(DnsServer *s, usec_t usec); +void dns_server_unlink(DnsServer *s); +void dns_server_move_back_and_unmark(DnsServer *s); + +void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t rtt, size_t size); +void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t usec); +void dns_server_packet_failed(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level); +void dns_server_packet_bad_opt(DnsServer *s, DnsServerFeatureLevel level); + +DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s); + +int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level); + +const char *dns_server_string(DnsServer *server); + +bool dns_server_dnssec_supported(DnsServer *server); + +DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr); + +void dns_server_unlink_all(DnsServer *first); +void dns_server_unlink_marked(DnsServer *first); +void dns_server_mark_all(DnsServer *first); + +DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t); + +DnsServer *manager_set_dns_server(Manager *m, DnsServer *s); +DnsServer *manager_get_dns_server(Manager *m); +void manager_next_dns_server(Manager *m); DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref); diff --git a/src/resolve/resolved-dns-stream.c b/src/resolve/resolved-dns-stream.c index 7f47e7223a..b72e6cc06f 100644 --- a/src/resolve/resolved-dns-stream.c +++ b/src/resolve/resolved-dns-stream.c @@ -21,6 +21,9 @@ #include <netinet/tcp.h> +#include "alloc-util.h" +#include "fd-util.h" +#include "io-util.h" #include "missing.h" #include "resolved-dns-stream.h" @@ -344,7 +347,6 @@ DnsStream *dns_stream_free(DnsStream *s) { DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_free); int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) { - static const int one = 1; _cleanup_(dns_stream_freep) DnsStream *s = NULL; int r; @@ -361,14 +363,12 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) { s->fd = -1; s->protocol = protocol; - r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); - if (r < 0) - return -errno; - r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s); if (r < 0) return r; + (void) sd_event_source_set_description(s->io_event_source, "dns-stream-io"); + r = sd_event_add_time( m->event, &s->timeout_event_source, @@ -378,6 +378,8 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd) { if (r < 0) return r; + (void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout"); + LIST_PREPEND(streams, m->dns_streams, s); s->manager = m; s->fd = fd; diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 8092bb514d..5640cd1d33 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -19,48 +19,101 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "af-list.h" +#include <sd-messages.h> -#include "resolved-llmnr.h" -#include "resolved-dns-transaction.h" -#include "random-util.h" +#include "af-list.h" +#include "alloc-util.h" #include "dns-domain.h" +#include "fd-util.h" +#include "random-util.h" +#include "resolved-dns-cache.h" +#include "resolved-dns-transaction.h" +#include "resolved-llmnr.h" +#include "string-table.h" + +#define TRANSACTIONS_MAX 4096 + +static void dns_transaction_reset_answer(DnsTransaction *t) { + assert(t); + + t->received = dns_packet_unref(t->received); + t->answer = dns_answer_unref(t->answer); + t->answer_rcode = 0; + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; + t->answer_authenticated = false; + t->answer_nsec_ttl = (uint32_t) -1; +} + +static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { + DnsTransaction *z; + + assert(t); + + while ((z = set_steal_first(t->dnssec_transactions))) { + set_remove(z->notify_transactions, t); + dns_transaction_gc(z); + } +} + +static void dns_transaction_close_connection(DnsTransaction *t) { + assert(t); + + t->stream = dns_stream_free(t->stream); + t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); + t->dns_udp_fd = safe_close(t->dns_udp_fd); +} + +static void dns_transaction_stop_timeout(DnsTransaction *t) { + assert(t); + + t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); +} DnsTransaction* dns_transaction_free(DnsTransaction *t) { - DnsQuery *q; + DnsQueryCandidate *c; DnsZoneItem *i; + DnsTransaction *z; if (!t) return NULL; - sd_event_source_unref(t->timeout_event_source); + log_debug("Freeing transaction %" PRIu16 ".", t->id); - dns_packet_unref(t->sent); - dns_packet_unref(t->received); - dns_answer_unref(t->cached); + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); - sd_event_source_unref(t->dns_udp_event_source); - safe_close(t->dns_udp_fd); + dns_packet_unref(t->sent); + dns_transaction_reset_answer(t); dns_server_unref(t->server); - dns_stream_free(t->stream); if (t->scope) { - hashmap_remove(t->scope->transactions, t->key); + hashmap_remove_value(t->scope->transactions_by_key, t->key, t); + LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); if (t->id != 0) hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); } - dns_resource_key_unref(t->key); - - while ((q = set_steal_first(t->queries))) - set_remove(q->transactions, t); - set_free(t->queries); + while ((c = set_steal_first(t->notify_query_candidates))) + set_remove(c->transactions, t); + set_free(t->notify_query_candidates); - while ((i = set_steal_first(t->zone_items))) + while ((i = set_steal_first(t->notify_zone_items))) i->probe_transaction = NULL; - set_free(t->zone_items); + set_free(t->notify_zone_items); + + while ((z = set_steal_first(t->notify_transactions))) + set_remove(z->dnssec_transactions, t); + set_free(t->notify_transactions); + + dns_transaction_flush_dnssec_transactions(t); + set_free(t->dnssec_transactions); + + dns_answer_unref(t->validated_keys); + dns_resource_key_unref(t->key); + free(t->key_string); free(t); return NULL; @@ -68,14 +121,36 @@ DnsTransaction* dns_transaction_free(DnsTransaction *t) { DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); -void dns_transaction_gc(DnsTransaction *t) { +bool dns_transaction_gc(DnsTransaction *t) { assert(t); if (t->block_gc > 0) - return; + return true; - if (set_isempty(t->queries) && set_isempty(t->zone_items)) + if (set_isempty(t->notify_query_candidates) && + set_isempty(t->notify_zone_items) && + set_isempty(t->notify_transactions)) { dns_transaction_free(t); + return false; + } + + return true; +} + +static uint16_t pick_new_id(Manager *m) { + uint16_t new_id; + + /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of + * transactions, and it's much lower than the space of IDs. */ + + assert_cc(TRANSACTIONS_MAX < 0xFFFF); + + do + random_bytes(&new_id, sizeof(new_id)); + while (new_id == 0 || + hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); + + return new_id; } int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { @@ -86,11 +161,24 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) assert(s); assert(key); + /* Don't allow looking up invalid or pseudo RRs */ + if (!dns_type_is_valid_query(key->type)) + return -EINVAL; + if (dns_type_is_obsolete(key->type)) + return -EOPNOTSUPP; + + /* We only support the IN class */ + if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) + return -EOPNOTSUPP; + + if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) + return -EBUSY; + r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); if (r < 0) return r; - r = hashmap_ensure_allocated(&s->transactions, &dns_resource_key_hash_ops); + r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); if (r < 0) return r; @@ -99,13 +187,13 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) return -ENOMEM; t->dns_udp_fd = -1; + t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_nsec_ttl = (uint32_t) -1; t->key = dns_resource_key_ref(key); + t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; - /* Find a fresh, unused transaction id */ - do - random_bytes(&t->id, sizeof(t->id)); - while (t->id == 0 || - hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); + t->id = pick_new_id(s->manager); r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); if (r < 0) { @@ -113,14 +201,17 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) return r; } - r = hashmap_put(s->transactions, t->key, t); + r = hashmap_replace(s->transactions_by_key, t->key, t); if (r < 0) { hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); return r; } + LIST_PREPEND(transactions_by_scope, s->transactions, t); t->scope = s; + s->manager->n_transactions_total ++; + if (ret) *ret = t; @@ -129,11 +220,20 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) return 0; } -static void dns_transaction_stop(DnsTransaction *t) { +static void dns_transaction_shuffle_id(DnsTransaction *t) { + uint16_t new_id; assert(t); - t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); - t->stream = dns_stream_free(t->stream); + /* Pick a new ID for this transaction. */ + + new_id = pick_new_id(t->scope->manager); + assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); + + log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); + t->id = new_id; + + /* Make sure we generate a new packet with the new ID */ + t->sent = dns_packet_unref(t->sent); } static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { @@ -148,7 +248,9 @@ static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { in_addr_to_string(p->family, &p->sender, &pretty); - log_debug("Transaction on scope %s on %s/%s got tentative packet from %s", + log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", + t->id, + dns_transaction_key_string(t), dns_protocol_to_string(t->scope->protocol), t->scope->link ? t->scope->link->name : "*", t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), @@ -164,7 +266,7 @@ static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); t->block_gc++; - while ((z = set_first(t->zone_items))) { + while ((z = set_first(t->notify_zone_items))) { /* First, make sure the zone item drops the reference * to us */ dns_zone_item_probe_stop(z); @@ -179,39 +281,140 @@ static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { } void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { - DnsQuery *q; + DnsQueryCandidate *c; DnsZoneItem *z; + DnsTransaction *d; Iterator i; assert(t); - assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); + assert(!DNS_TRANSACTION_IS_LIVE(state)); + + if (state == DNS_TRANSACTION_DNSSEC_FAILED) + log_struct(LOG_NOTICE, + LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), + LOG_MESSAGE("DNSSEC validation failed for question %s: %s", dns_transaction_key_string(t), dnssec_result_to_string(t->answer_dnssec_result)), + "DNS_TRANSACTION=%" PRIu16, t->id, + "DNS_QUESTION=%s", dns_transaction_key_string(t), + "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), + NULL); /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction * after calling this function. */ - log_debug("Transaction on scope %s on %s/%s now complete with <%s>", + log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", + t->id, + dns_transaction_key_string(t), dns_protocol_to_string(t->scope->protocol), t->scope->link ? t->scope->link->name : "*", t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), - dns_transaction_state_to_string(state)); + dns_transaction_state_to_string(state), + t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), + t->answer_authenticated ? "authenticated" : "unsigned"); t->state = state; - dns_transaction_stop(t); + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); /* Notify all queries that are interested, but make sure the * transaction isn't freed while we are still looking at it */ t->block_gc++; - SET_FOREACH(q, t->queries, i) - dns_query_ready(q); - SET_FOREACH(z, t->zone_items, i) - dns_zone_item_ready(z); - t->block_gc--; + SET_FOREACH(c, t->notify_query_candidates, i) + dns_query_candidate_notify(c); + SET_FOREACH(z, t->notify_zone_items, i) + dns_zone_item_notify(z); + + if (!set_isempty(t->notify_transactions)) { + DnsTransaction **nt; + unsigned j, n = 0; + + /* We need to be careful when notifying other + * transactions, as that might destroy other + * transactions in our list. Hence, in order to be + * able to safely iterate through the list of + * transactions, take a GC lock on all of them + * first. Then, in a second loop, notify them, but + * first unlock that specific transaction. */ + + nt = newa(DnsTransaction*, set_size(t->notify_transactions)); + SET_FOREACH(d, t->notify_transactions, i) { + nt[n++] = d; + d->block_gc++; + } + + assert(n == set_size(t->notify_transactions)); + + for (j = 0; j < n; j++) { + if (set_contains(t->notify_transactions, nt[j])) + dns_transaction_notify(nt[j], t); + + nt[j]->block_gc--; + dns_transaction_gc(nt[j]); + } + } + + t->block_gc--; dns_transaction_gc(t); } +static int dns_transaction_pick_server(DnsTransaction *t) { + DnsServer *server; + + assert(t); + assert(t->scope->protocol == DNS_PROTOCOL_DNS); + + server = dns_scope_get_dns_server(t->scope); + if (!server) + return -ESRCH; + + t->current_feature_level = dns_server_possible_feature_level(server); + + if (server == t->server) + return 0; + + dns_server_unref(t->server); + t->server = dns_server_ref(server); + + return 1; +} + +static void dns_transaction_retry(DnsTransaction *t) { + int r; + + assert(t); + + log_debug("Retrying transaction %" PRIu16 ".", t->id); + + /* Before we try again, switch to a new server. */ + dns_scope_next_dns_server(t->scope); + + r = dns_transaction_go(t); + if (r < 0) + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); +} + +static int dns_transaction_maybe_restart(DnsTransaction *t) { + assert(t); + + if (!t->server) + return 0; + + if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) + return 0; + + /* The server's current feature level is lower than when we sent the original query. We learnt something from + the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to + restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include + OPT RR or DO bit. One of these cases is documented here, for example: + https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ + + log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); + dns_transaction_shuffle_id(t); + return dns_transaction_go(t); +} + static int on_stream_complete(DnsStream *s, int error) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; DnsTransaction *t; @@ -226,13 +429,23 @@ static int on_stream_complete(DnsStream *s, int error) { t->stream = dns_stream_free(t->stream); + if (ERRNO_IS_DISCONNECT(error)) { + usec_t usec; + + log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); + dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); + + dns_transaction_retry(t); + return 0; + } if (error != 0) { dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); return 0; } if (dns_packet_validate_reply(p) <= 0) { - log_debug("Invalid LLMNR TCP packet."); + log_debug("Invalid TCP reply packet."); dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); return 0; } @@ -243,32 +456,46 @@ static int on_stream_complete(DnsStream *s, int error) { dns_transaction_process_reply(t, p); t->block_gc--; - /* If the response wasn't useful, then complete the transition now */ + /* If the response wasn't useful, then complete the transition + * now. After all, we are the worst feature set now with TCP + * sockets, and there's really no point in retrying. */ if (t->state == DNS_TRANSACTION_PENDING) dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + else + dns_transaction_gc(t); return 0; } static int dns_transaction_open_tcp(DnsTransaction *t) { - DnsServer *server = NULL; _cleanup_close_ int fd = -1; int r; assert(t); - if (t->stream) - return 0; + dns_transaction_close_connection(t); switch (t->scope->protocol) { + case DNS_PROTOCOL_DNS: - fd = dns_scope_tcp_socket(t->scope, AF_UNSPEC, NULL, 53, &server); + r = dns_transaction_pick_server(t); + if (r < 0) + return r; + + if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) + return -EOPNOTSUPP; + + r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); + if (r < 0) + return r; + + fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); break; case DNS_PROTOCOL_LLMNR: /* When we already received a reply to this (but it was truncated), send to its sender address */ if (t->received) - fd = dns_scope_tcp_socket(t->scope, t->received->family, &t->received->sender, t->received->sender_port, NULL); + fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); else { union in_addr_union address; int family = AF_UNSPEC; @@ -285,7 +512,7 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { if (family != t->scope->family) return -ESRCH; - fd = dns_scope_tcp_socket(t->scope, family, &address, LLMNR_PORT, NULL); + fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); } break; @@ -300,7 +527,6 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); if (r < 0) return r; - fd = -1; r = dns_stream_write_packet(t->stream, t->sent); @@ -309,9 +535,6 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { return r; } - dns_server_unref(t->server); - t->server = dns_server_ref(server); - t->received = dns_packet_unref(t->received); t->stream->complete = on_stream_complete; t->stream->transaction = t; @@ -321,17 +544,165 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { if (t->scope->link) t->stream->ifindex = t->scope->link->ifindex; + dns_transaction_reset_answer(t); + + t->tried_stream = true; + return 0; } -static void dns_transaction_next_dns_server(DnsTransaction *t) { +static void dns_transaction_cache_answer(DnsTransaction *t) { assert(t); - t->server = dns_server_unref(t->server); - t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); - t->dns_udp_fd = safe_close(t->dns_udp_fd); + /* For mDNS we cache whenever we get the packet, rather than + * in each transaction. */ + if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) + return; - dns_scope_next_dns_server(t->scope); + /* We never cache if this packet is from the local host, under + * the assumption that a locally running DNS server would + * cache this anyway, and probably knows better when to flush + * the cache then we could. */ + if (!DNS_PACKET_SHALL_CACHE(t->received)) + return; + + dns_cache_put(&t->scope->cache, + t->key, + t->answer_rcode, + t->answer, + t->answer_authenticated, + t->answer_nsec_ttl, + 0, + t->received->family, + &t->received->sender); +} + +static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + SET_FOREACH(dt, t->dnssec_transactions, i) + if (DNS_TRANSACTION_IS_LIVE(dt->state)) + return true; + + return false; +} + +static int dns_transaction_dnssec_ready(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still + * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + switch (dt->state) { + + case DNS_TRANSACTION_NULL: + case DNS_TRANSACTION_PENDING: + case DNS_TRANSACTION_VALIDATING: + /* Still ongoing */ + return 0; + + case DNS_TRANSACTION_RCODE_FAILURE: + if (dt->answer_rcode != DNS_RCODE_NXDOMAIN) { + log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); + goto fail; + } + + /* Fall-through: NXDOMAIN is good enough for us. This is because some DNS servers erronously + * return NXDOMAIN for empty non-terminals (Akamai...), and we need to handle that nicely, when + * asking for parent SOA or similar RRs to make unsigned proofs. */ + + case DNS_TRANSACTION_SUCCESS: + /* All good. */ + break; + + case DNS_TRANSACTION_DNSSEC_FAILED: + /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC + * validationr result */ + + log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); + t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return 0; + + + default: + log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); + goto fail; + } + } + + /* All is ready, we can go and validate */ + return 1; + +fail: + t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return 0; +} + +static void dns_transaction_process_dnssec(DnsTransaction *t) { + int r; + + assert(t); + + /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ + r = dns_transaction_dnssec_ready(t); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ + return; + + /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better + * restart the lookup immediately. */ + r = dns_transaction_maybe_restart(t); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + if (r > 0) /* Transaction got restarted... */ + return; + + /* All our auxiliary DNSSEC transactions are complete now. Try + * to validate our RRset now. */ + r = dns_transaction_validate_dnssec(t); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + + if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && + t->scope->dnssec_mode == DNSSEC_YES) { + /* We are not in automatic downgrade mode, and the + * server is bad, refuse operation. */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return; + } + + if (!IN_SET(t->answer_dnssec_result, + _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ + DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ + DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ + DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ + dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); + return; + } + + dns_transaction_cache_answer(t); + + if (t->answer_rcode == DNS_RCODE_SUCCESS) + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + else + dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); } void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { @@ -340,15 +711,20 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { assert(t); assert(p); - assert(t->state == DNS_TRANSACTION_PENDING); assert(t->scope); assert(t->scope->manager); + if (t->state != DNS_TRANSACTION_PENDING) + return; + /* Note that this call might invalidate the query. Callers * should hence not attempt to access the query or transaction * after calling this function. */ + log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); + switch (t->scope->protocol) { + case DNS_PROTOCOL_LLMNR: assert(t->scope->link); @@ -371,7 +747,24 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { break; + case DNS_PROTOCOL_MDNS: + assert(t->scope->link); + + /* For mDNS we will not accept any packets from other interfaces */ + if (p->ifindex != t->scope->link->ifindex) + return; + + if (p->family != t->scope->family) + return; + + break; + case DNS_PROTOCOL_DNS: + /* Note that we do not need to verify the + * addresses/port numbers of incoming traffic, as we + * invoked connect() on our UDP socket in which case + * the kernel already does the needed verification for + * us. */ break; default: @@ -383,6 +776,8 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { t->received = dns_packet_ref(p); } + t->answer_source = DNS_TRANSACTION_NETWORK; + if (p->ipproto == IPPROTO_TCP) { if (DNS_PACKET_TC(p)) { /* Truncated via TCP? Somebody must be fucking with us */ @@ -400,22 +795,42 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); switch (t->scope->protocol) { + case DNS_PROTOCOL_DNS: assert(t->server); - dns_server_packet_received(t->server, ts - t->start_usec); + if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { + + /* Request failed, immediately try again with reduced features */ + log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); + + dns_server_packet_failed(t->server, t->current_feature_level); + dns_transaction_retry(t); + return; + } else if (DNS_PACKET_TC(p)) + dns_server_packet_truncated(t->server, t->current_feature_level); break; + case DNS_PROTOCOL_LLMNR: case DNS_PROTOCOL_MDNS: dns_scope_packet_received(t->scope, ts - t->start_usec); - break; + default: - break; + assert_not_reached("Invalid DNS protocol."); } if (DNS_PACKET_TC(p)) { + + /* Truncated packets for mDNS are not allowed. Give up immediately. */ + if (t->scope->protocol == DNS_PROTOCOL_MDNS) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + log_debug("Reply truncated, retrying via TCP."); + /* Response was truncated, let's try again with good old TCP */ r = dns_transaction_open_tcp(t); if (r == -ESRCH) { @@ -423,47 +838,100 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); return; } + if (r == -EOPNOTSUPP) { + /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ + dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); + return; + } if (r < 0) { /* On LLMNR, if we cannot connect to the host, * we immediately give up */ - if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { + if (t->scope->protocol != DNS_PROTOCOL_DNS) { dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); return; } /* On DNS, couldn't send? Try immediately again, with a new server */ - dns_transaction_next_dns_server(t); - - r = dns_transaction_go(t); - if (r < 0) { - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); - return; - } - - return; + dns_transaction_retry(t); } + + return; } - /* Parse and update the cache */ + /* After the superficial checks, actually parse the message. */ r = dns_packet_extract(p); if (r < 0) { dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); return; } - /* Only consider responses with equivalent query section to the request */ - if (p->question->n_keys != 1 || dns_resource_key_equal(p->question->keys[0], t->key) <= 0) { - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + /* Report that the OPT RR was missing */ + if (t->server) { + if (!p->opt) + dns_server_packet_bad_opt(t->server, t->current_feature_level); + + dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); + } + + /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ + r = dns_transaction_maybe_restart(t); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); return; } + if (r > 0) /* Transaction got restarted... */ + return; - /* According to RFC 4795, section 2.9. only the RRs from the answer section shall be cached */ - dns_cache_put(&t->scope->cache, p->question, DNS_PACKET_RCODE(p), p->answer, DNS_PACKET_ANCOUNT(p), 0, p->family, &p->sender); + if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { - if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS) - dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); - else - dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); + /* Only consider responses with equivalent query section to the request */ + r = dns_packet_is_reply_for(p, t->key); + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + if (r == 0) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } + + /* Install the answer as answer to the transaction */ + dns_answer_unref(t->answer); + t->answer = dns_answer_ref(p->answer); + t->answer_rcode = DNS_PACKET_RCODE(p); + t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + t->answer_authenticated = false; + + /* Block GC while starting requests for additional DNSSEC RRs */ + t->block_gc++; + r = dns_transaction_request_dnssec_keys(t); + t->block_gc--; + + /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ + if (!dns_transaction_gc(t)) + return; + + /* Requesting additional keys might have resulted in + * this transaction to fail, since the auxiliary + * request failed for some reason. If so, we are not + * in pending state anymore, and we should exit + * quickly. */ + if (t->state != DNS_TRANSACTION_PENDING) + return; + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return; + } + if (r > 0) { + /* There are DNSSEC transactions pending now. Update the state accordingly. */ + t->state = DNS_TRANSACTION_VALIDATING; + dns_transaction_close_connection(t); + dns_transaction_stop_timeout(t); + return; + } + } + + dns_transaction_process_dnssec(t); } static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { @@ -475,99 +943,125 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use assert(t->scope); r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); - if (r <= 0) - return r; + if (ERRNO_IS_DISCONNECT(-r)) { + usec_t usec; - if (dns_packet_validate_reply(p) > 0 && - DNS_PACKET_ID(p) == t->id) - dns_transaction_process_reply(t, p); - else - log_debug("Invalid DNS packet."); + /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next + * recvmsg(). Treat this like a lost packet. */ + + log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); + dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); + dns_transaction_retry(t); + return 0; + } + if (r < 0) { + dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return 0; + } + + r = dns_packet_validate_reply(p); + if (r < 0) { + log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); + return 0; + } + if (r == 0) { + log_debug("Received inappropriate DNS packet as response, ignoring."); + return 0; + } + + if (DNS_PACKET_ID(p) != t->id) { + log_debug("Received packet with incorrect transaction ID, ignoring."); + return 0; + } + + dns_transaction_process_reply(t, p); return 0; } -static int dns_transaction_emit(DnsTransaction *t) { +static int dns_transaction_emit_udp(DnsTransaction *t) { int r; assert(t); - if (t->scope->protocol == DNS_PROTOCOL_DNS && !t->server) { - DnsServer *server = NULL; - _cleanup_close_ int fd = -1; - - fd = dns_scope_udp_dns_socket(t->scope, &server); - if (fd < 0) - return fd; + if (t->scope->protocol == DNS_PROTOCOL_DNS) { - r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); + r = dns_transaction_pick_server(t); if (r < 0) return r; - t->dns_udp_fd = fd; - fd = -1; - t->server = dns_server_ref(server); - } + if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) + return -EAGAIN; - r = dns_scope_emit(t->scope, t->dns_udp_fd, t->sent); - if (r < 0) - return r; + if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) + return -EOPNOTSUPP; - return 0; -} + if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ + int fd; -static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { - DnsTransaction *t = userdata; - int r; + dns_transaction_close_connection(t); - assert(s); - assert(t); + fd = dns_scope_socket_udp(t->scope, t->server, 53); + if (fd < 0) + return fd; - /* Timeout reached? Try again, with a new server */ - dns_transaction_next_dns_server(t); + r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); + if (r < 0) { + safe_close(fd); + return r; + } - /* ... and possibly increased timeout */ - if (t->server) - dns_server_packet_lost(t->server, usec - t->start_usec); - else - dns_scope_packet_lost(t->scope, usec - t->start_usec); + (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); + t->dns_udp_fd = fd; + } - r = dns_transaction_go(t); + r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); + if (r < 0) + return r; + } else + dns_transaction_close_connection(t); + + r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); if (r < 0) - dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); + return r; + + dns_transaction_reset_answer(t); return 0; } -static int dns_transaction_make_packet(DnsTransaction *t) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - int r; +static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { + DnsTransaction *t = userdata; + assert(s); assert(t); - if (t->sent) - return 0; + if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { + /* Timeout reached? Increase the timeout for the server used */ + switch (t->scope->protocol) { - r = dns_packet_new_query(&p, t->scope->protocol, 0); - if (r < 0) - return r; + case DNS_PROTOCOL_DNS: + assert(t->server); + dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); + break; - r = dns_scope_good_key(t->scope, t->key); - if (r < 0) - return r; - if (r == 0) - return -EDOM; + case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + dns_scope_packet_lost(t->scope, usec - t->start_usec); + break; - r = dns_packet_append_key(p, t->key, NULL); - if (r < 0) - return r; + default: + assert_not_reached("Invalid DNS protocol."); + } - DNS_PACKET_HEADER(p)->qdcount = htobe16(1); - DNS_PACKET_HEADER(p)->id = t->id; + if (t->initial_jitter_scheduled) + t->initial_jitter_elapsed = true; + } - t->sent = p; - p = NULL; + log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); + dns_transaction_retry(t); return 0; } @@ -576,57 +1070,116 @@ static usec_t transaction_get_resend_timeout(DnsTransaction *t) { assert(t->scope); switch (t->scope->protocol) { + case DNS_PROTOCOL_DNS: assert(t->server); - return t->server->resend_timeout; - case DNS_PROTOCOL_LLMNR: + case DNS_PROTOCOL_MDNS: + assert(t->n_attempts > 0); + return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; + + case DNS_PROTOCOL_LLMNR: return t->scope->resend_timeout; + default: assert_not_reached("Invalid DNS protocol."); } } -int dns_transaction_go(DnsTransaction *t) { - bool had_stream; - usec_t ts; +static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { int r; assert(t); - had_stream = !!t->stream; - - dns_transaction_stop(t); - - log_debug("Excercising transaction on scope %s on %s/%s", - dns_protocol_to_string(t->scope->protocol), - t->scope->link ? t->scope->link->name : "*", - t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); + dns_transaction_stop_timeout(t); if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); return 0; } - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && had_stream) { + if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { /* If we already tried via a stream, then we don't * retry on LLMNR. See RFC 4795, Section 2.7. */ dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); return 0; } - assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); - t->n_attempts++; t->start_usec = ts; - t->received = dns_packet_unref(t->received); - t->cached = dns_answer_unref(t->cached); - t->cached_rcode = 0; + + dns_transaction_reset_answer(t); + dns_transaction_flush_dnssec_transactions(t); + + /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ + if (t->scope->protocol == DNS_PROTOCOL_DNS) { + r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); + if (r < 0) + return r; + if (r > 0) { + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; + t->answer_authenticated = true; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + return 0; + } + + if (dns_name_is_root(DNS_RESOURCE_KEY_NAME(t->key)) && + t->key->type == DNS_TYPE_DS) { + + /* Hmm, this is a request for the root DS? A + * DS RR doesn't exist in the root zone, and + * if our trust anchor didn't know it either, + * this means we cannot do any DNSSEC logic + * anymore. */ + + if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { + /* We are in downgrade mode. In this + * case, synthesize an unsigned empty + * response, so that the any lookup + * depending on this one can continue + * assuming there was no DS, and hence + * the root zone was unsigned. */ + + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; + t->answer_authenticated = false; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + } else + /* If we are not in downgrade mode, + * then fail the lookup, because we + * cannot reasonably answer it. There + * might be DS RRs, but we don't know + * them, and the DNS server won't tell + * them to us (and even if it would, + * we couldn't validate it and trust + * it). */ + dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); + + return 0; + } + } + + /* Check the zone, but only if this transaction is not used + * for probing or verifying a zone item. */ + if (set_isempty(t->notify_zone_items)) { + + r = dns_zone_lookup(&t->scope->zone, t->key, &t->answer, NULL, NULL); + if (r < 0) + return r; + if (r > 0) { + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_source = DNS_TRANSACTION_ZONE; + t->answer_authenticated = true; + dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); + return 0; + } + } /* Check the cache, but only if this transaction is not used * for probing or verifying a zone item. */ - if (set_isempty(t->zone_items)) { + if (set_isempty(t->notify_zone_items)) { /* Before trying the cache, let's make sure we figured out a * server to use. Should this cause a change of server this @@ -636,43 +1189,224 @@ int dns_transaction_go(DnsTransaction *t) { /* Let's then prune all outdated entries */ dns_cache_prune(&t->scope->cache); - r = dns_cache_lookup(&t->scope->cache, t->key, &t->cached_rcode, &t->cached); + r = dns_cache_lookup(&t->scope->cache, t->key, &t->answer_rcode, &t->answer, &t->answer_authenticated); if (r < 0) return r; if (r > 0) { - if (t->cached_rcode == DNS_RCODE_SUCCESS) + t->answer_source = DNS_TRANSACTION_CACHE; + if (t->answer_rcode == DNS_RCODE_SUCCESS) dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); else - dns_transaction_complete(t, DNS_TRANSACTION_FAILURE); + dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); return 0; } } - if (t->scope->protocol == DNS_PROTOCOL_LLMNR && !t->initial_jitter) { - usec_t jitter; + return 1; +} + +static int dns_transaction_make_packet_mdns(DnsTransaction *t) { + + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + bool add_known_answers = false; + DnsTransaction *other; + unsigned qdcount; + usec_t ts; + int r; + + assert(t); + assert(t->scope->protocol == DNS_PROTOCOL_MDNS); + + /* Discard any previously prepared packet, so we can start over and coalesce again */ + t->sent = dns_packet_unref(t->sent); + + r = dns_packet_new_query(&p, t->scope->protocol, 0, false); + if (r < 0) + return r; + + r = dns_packet_append_key(p, t->key, NULL); + if (r < 0) + return r; + + qdcount = 1; + + if (dns_key_is_shared(t->key)) + add_known_answers = true; + + /* + * For mDNS, we want to coalesce as many open queries in pending transactions into one single + * query packet on the wire as possible. To achieve that, we iterate through all pending transactions + * in our current scope, and see whether their timing contraints allow them to be sent. + */ + + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { + + /* Skip ourselves */ + if (other == t) + continue; + + if (other->state != DNS_TRANSACTION_PENDING) + continue; + + if (other->next_attempt_after > ts) + continue; + + if (qdcount >= UINT16_MAX) + break; + + r = dns_packet_append_key(p, other->key, NULL); + + /* + * If we can't stuff more questions into the packet, just give up. + * One of the 'other' transactions will fire later and take care of the rest. + */ + if (r == -EMSGSIZE) + break; + + if (r < 0) + return r; + + r = dns_transaction_prepare(other, ts); + if (r <= 0) + continue; + + ts += transaction_get_resend_timeout(other); + + r = sd_event_add_time( + other->scope->manager->event, + &other->timeout_event_source, + clock_boottime_or_monotonic(), + ts, 0, + on_transaction_timeout, other); + if (r < 0) + return r; + + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + + other->state = DNS_TRANSACTION_PENDING; + other->next_attempt_after = ts; + + qdcount ++; + + if (dns_key_is_shared(other->key)) + add_known_answers = true; + } + + DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); + + /* Append known answer section if we're asking for any shared record */ + if (add_known_answers) { + r = dns_cache_export_shared_to_packet(&t->scope->cache, p); + if (r < 0) + return r; + } + + t->sent = p; + p = NULL; + + return 0; +} + +static int dns_transaction_make_packet(DnsTransaction *t) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + int r; + + assert(t); + + if (t->scope->protocol == DNS_PROTOCOL_MDNS) + return dns_transaction_make_packet_mdns(t); + + if (t->sent) + return 0; + + r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); + if (r < 0) + return r; + + r = dns_scope_good_key(t->scope, t->key); + if (r < 0) + return r; + if (r == 0) + return -EDOM; + + r = dns_packet_append_key(p, t->key, NULL); + if (r < 0) + return r; + + DNS_PACKET_HEADER(p)->qdcount = htobe16(1); + DNS_PACKET_HEADER(p)->id = t->id; + + t->sent = p; + p = NULL; + + return 0; +} + +int dns_transaction_go(DnsTransaction *t) { + usec_t ts; + int r; + + assert(t); + + assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); + + r = dns_transaction_prepare(t, ts); + if (r <= 0) + return r; + + log_debug("Excercising transaction %" PRIu16 " for <%s> on scope %s on %s/%s.", + t->id, + dns_transaction_key_string(t), + dns_protocol_to_string(t->scope->protocol), + t->scope->link ? t->scope->link->name : "*", + t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); + + if (!t->initial_jitter_scheduled && + (t->scope->protocol == DNS_PROTOCOL_LLMNR || + t->scope->protocol == DNS_PROTOCOL_MDNS)) { + usec_t jitter, accuracy; /* RFC 4795 Section 2.7 suggests all queries should be * delayed by a random time from 0 to JITTER_INTERVAL. */ - t->initial_jitter = true; + t->initial_jitter_scheduled = true; random_bytes(&jitter, sizeof(jitter)); - jitter %= LLMNR_JITTER_INTERVAL_USEC; + + switch (t->scope->protocol) { + + case DNS_PROTOCOL_LLMNR: + jitter %= LLMNR_JITTER_INTERVAL_USEC; + accuracy = LLMNR_JITTER_INTERVAL_USEC; + break; + + case DNS_PROTOCOL_MDNS: + jitter %= MDNS_JITTER_RANGE_USEC; + jitter += MDNS_JITTER_MIN_USEC; + accuracy = MDNS_JITTER_RANGE_USEC; + break; + default: + assert_not_reached("bad protocol"); + } r = sd_event_add_time( t->scope->manager->event, &t->timeout_event_source, clock_boottime_or_monotonic(), - ts + jitter, - LLMNR_JITTER_INTERVAL_USEC, + ts + jitter, accuracy, on_transaction_timeout, t); if (r < 0) return r; + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + t->n_attempts = 0; + t->next_attempt_after = ts; t->state = DNS_TRANSACTION_PENDING; - log_debug("Delaying LLMNR transaction for " USEC_FMT "us.", jitter); + log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); return 0; } @@ -696,44 +1430,1535 @@ int dns_transaction_go(DnsTransaction *t) { * always be made via TCP on LLMNR */ r = dns_transaction_open_tcp(t); } else { - /* Try via UDP, and if that fails due to large size try via TCP */ - r = dns_transaction_emit(t); + /* Try via UDP, and if that fails due to large size or lack of + * support try via TCP */ + r = dns_transaction_emit_udp(t); if (r == -EMSGSIZE) + log_debug("Sending query via TCP since it is too large."); + if (r == -EAGAIN) + log_debug("Sending query via TCP since server doesn't support UDP."); + if (r == -EMSGSIZE || r == -EAGAIN) r = dns_transaction_open_tcp(t); } + if (r == -ESRCH) { /* No servers to send this to? */ dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); return 0; - } else if (r < 0) { + } + if (r == -EOPNOTSUPP) { + /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ + dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); + return 0; + } + if (r < 0) { if (t->scope->protocol != DNS_PROTOCOL_DNS) { dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); return 0; } /* Couldn't send? Try immediately again, with a new server */ - dns_transaction_next_dns_server(t); + dns_scope_next_dns_server(t->scope); return dns_transaction_go(t); } + ts += transaction_get_resend_timeout(t); + r = sd_event_add_time( t->scope->manager->event, &t->timeout_event_source, clock_boottime_or_monotonic(), - ts + transaction_get_resend_timeout(t), 0, + ts, 0, on_transaction_timeout, t); if (r < 0) return r; + (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); + t->state = DNS_TRANSACTION_PENDING; + t->next_attempt_after = ts; + return 1; } +static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { + DnsTransaction *n; + Iterator i; + int r; + + assert(t); + assert(aux); + + /* Try to find cyclic dependencies between transaction objects */ + + if (t == aux) + return 1; + + SET_FOREACH(n, aux->dnssec_transactions, i) { + r = dns_transaction_find_cyclic(t, n); + if (r != 0) + return r; + } + + return 0; +} + +static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { + DnsTransaction *aux; + int r; + + assert(t); + assert(ret); + assert(key); + + aux = dns_scope_find_transaction(t->scope, key, true); + if (!aux) { + r = dns_transaction_new(&aux, t->scope, key); + if (r < 0) + return r; + } else { + if (set_contains(t->dnssec_transactions, aux)) { + *ret = aux; + return 0; + } + + r = dns_transaction_find_cyclic(t, aux); + if (r < 0) + return r; + if (r > 0) { + log_debug("Detected potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", + aux->id, + strna(dns_transaction_key_string(aux)), + t->id, + strna(dns_transaction_key_string(t))); + return -ELOOP; + } + } + + r = set_ensure_allocated(&t->dnssec_transactions, NULL); + if (r < 0) + goto gc; + + r = set_ensure_allocated(&aux->notify_transactions, NULL); + if (r < 0) + goto gc; + + r = set_put(t->dnssec_transactions, aux); + if (r < 0) + goto gc; + + r = set_put(aux->notify_transactions, t); + if (r < 0) { + (void) set_remove(t->dnssec_transactions, aux); + goto gc; + } + + *ret = aux; + return 1; + +gc: + dns_transaction_gc(aux); + return r; +} + +static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { + _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; + DnsTransaction *aux; + int r; + + assert(t); + assert(key); + + /* Try to get the data from the trust anchor */ + r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); + if (r < 0) + return r; + if (r > 0) { + r = dns_answer_extend(&t->validated_keys, a); + if (r < 0) + return r; + + return 0; + } + + /* This didn't work, ask for it via the network/cache then. */ + r = dns_transaction_add_dnssec_transaction(t, key, &aux); + if (r == -ELOOP) /* This would result in a cyclic dependency */ + return 0; + if (r < 0) + return r; + + if (aux->state == DNS_TRANSACTION_NULL) { + r = dns_transaction_go(aux); + if (r < 0) + return r; + } + + return 1; +} + +static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { + int r; + + assert(t); + + /* Checks whether the answer is positive, i.e. either a direct + * answer to the question, or a CNAME/DNAME for it */ + + r = dns_answer_match_key(t->answer, t->key, flags); + if (r != 0) + return r; + + r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); + if (r != 0) + return r; + + return false; +} + +static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { + int r; + + assert(t); + + /* Check whether the specified name is in the the NTA + * database, either in the global one, or the link-local + * one. */ + + r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); + if (r != 0) + return r; + + if (!t->scope->link) + return 0; + + return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); +} + +static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { + int r; + + assert(t); + + /* Checks whether the answer is negative, and lacks NSEC/NSEC3 + * RRs to prove it */ + + r = dns_transaction_has_positive_answer(t, NULL); + if (r < 0) + return r; + if (r > 0) + return false; + + /* Is this key explicitly listed as a negative trust anchor? + * If so, it's nothing we need to care about */ + r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + /* The answer does not contain any RRs that match to the + * question. If so, let's see if there are any NSEC/NSEC3 RRs + * included. If not, the answer is unsigned. */ + + r = dns_answer_contains_nsec_or_nsec3(t->answer); + if (r < 0) + return r; + if (r > 0) + return false; + + return true; +} + +static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { + int r; + + assert(t); + assert(rr); + + /* Check if the specified RR is the "primary" response, + * i.e. either matches the question precisely or is a + * CNAME/DNAME for it, or is any kind of NSEC/NSEC3 RR */ + + r = dns_resource_key_match_rr(t->key, rr, NULL); + if (r != 0) + return r; + + r = dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); + if (r != 0) + return r; + + if (rr->key->type == DNS_TYPE_NSEC3) { + const char *p; + + p = DNS_RESOURCE_KEY_NAME(rr->key); + r = dns_name_parent(&p); + if (r < 0) + return r; + if (r > 0) { + r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), p); + if (r < 0) + return r; + if (r > 0) + return true; + } + } + + return rr->key->type == DNS_TYPE_NSEC; +} + +static bool dns_transaction_dnssec_supported(DnsTransaction *t) { + assert(t); + + /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon + * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ + + if (t->scope->protocol != DNS_PROTOCOL_DNS) + return false; + + /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well + * be supported, hence return true. */ + if (!t->server) + return true; + + if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_DO) + return false; + + return dns_server_dnssec_supported(t->server); +} + +static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + + assert(t); + + /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ + + if (!dns_transaction_dnssec_supported(t)) + return false; + + SET_FOREACH(dt, t->dnssec_transactions, i) + if (!dns_transaction_dnssec_supported(dt)) + return false; + + return true; +} + +int dns_transaction_request_dnssec_keys(DnsTransaction *t) { + DnsResourceRecord *rr; + + int r; + + assert(t); + + /* + * Retrieve all auxiliary RRs for the answer we got, so that + * we can verify signatures or prove that RRs are rightfully + * unsigned. Specifically: + * + * - For RRSIG we get the matching DNSKEY + * - For DNSKEY we get the matching DS + * - For unsigned SOA/NS we get the matching DS + * - For unsigned CNAME/DNAME/DS we get the parent SOA RR + * - For other unsigned RRs we get the matching SOA RR + * - For SOA/NS/DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR + * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR + */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return 0; + if (t->answer_source != DNS_TRANSACTION_NETWORK) + return 0; /* We only need to validate stuff from the network */ + if (!dns_transaction_dnssec_supported(t)) + return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ + + DNS_ANSWER_FOREACH(rr, t->answer) { + + if (dns_type_is_pseudo(rr->key->type)) + continue; + + /* If this RR is in the negative trust anchor, we don't need to validate it. */ + r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r > 0) + continue; + + switch (rr->key->type) { + + case DNS_TYPE_RRSIG: { + /* For each RRSIG we request the matching DNSKEY */ + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; + + /* If this RRSIG is about a DNSKEY RR and the + * signer is the same as the owner, then we + * already have the DNSKEY, and we don't have + * to look for more. */ + if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { + r = dns_name_equal(rr->rrsig.signer, DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r > 0) + continue; + } + + /* If the signer is not a parent of our + * original query, then this is about an + * auxiliary RRset, but not anything we asked + * for. In this case we aren't interested, + * because we don't want to request additional + * RRs for stuff we didn't really ask for, and + * also to avoid request loops, where + * additional RRs from one transaction result + * in another transaction whose additonal RRs + * point back to the original transaction, and + * we deadlock. */ + r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), rr->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); + if (!dnskey) + return -ENOMEM; + + log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", t->id, DNS_RESOURCE_KEY_NAME(rr->key), rr->rrsig.key_tag); + r = dns_transaction_request_dnssec_rr(t, dnskey); + if (r < 0) + return r; + break; + } + + case DNS_TYPE_DNSKEY: { + /* For each DNSKEY we request the matching DS */ + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; + + /* If the DNSKEY we are looking at is not for + * zone we are interested in, nor any of its + * parents, we aren't interested, and don't + * request it. After all, we don't want to end + * up in request loops, and want to keep + * additional traffic down. */ + + r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); + if (!ds) + return -ENOMEM; + + log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", t->id, DNS_RESOURCE_KEY_NAME(rr->key), dnssec_keytag(rr, false)); + r = dns_transaction_request_dnssec_rr(t, ds); + if (r < 0) + return r; + + break; + } + + case DNS_TYPE_SOA: + case DNS_TYPE_NS: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; + + /* For an unsigned SOA or NS, try to acquire + * the matching DS RR, as we are at a zone cut + * then, and whether a DS exists tells us + * whether the zone is signed. Do so only if + * this RR matches our original question, + * however. */ + + r = dns_resource_key_match_rr(t->key, rr, NULL); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); + if (!ds) + return -ENOMEM; + + log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); + r = dns_transaction_request_dnssec_rr(t, ds); + if (r < 0) + return r; + + break; + } + + case DNS_TYPE_DS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + const char *name; + + /* CNAMEs and DNAMEs cannot be located at a + * zone apex, hence ask for the parent SOA for + * unsigned CNAME/DNAME RRs, maybe that's the + * apex. But do all that only if this is + * actually a response to our original + * question. + * + * Similar for DS RRs, which are signed when + * the parent SOA is signed. */ + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + r = dns_answer_has_dname_for_cname(t->answer, rr); + if (r < 0) + return r; + if (r > 0) + continue; + + name = DNS_RESOURCE_KEY_NAME(rr->key); + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + continue; + + soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); + if (!soa) + return -ENOMEM; + + log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + + break; + } + + default: { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + + /* For other unsigned RRsets (including + * NSEC/NSEC3!), look for proof the zone is + * unsigned, by requesting the SOA RR of the + * zone. However, do so only if they are + * directly relevant to our original + * question. */ + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_has_rrsig(t->answer, rr->key); + if (r < 0) + return r; + if (r > 0) + continue; + + soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, DNS_RESOURCE_KEY_NAME(rr->key)); + if (!soa) + return -ENOMEM; + + log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", t->id, DNS_RESOURCE_KEY_NAME(rr->key), dns_resource_record_to_string(rr)); + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + break; + }} + } + + /* Above, we requested everything necessary to validate what + * we got. Now, let's request what we need to validate what we + * didn't get... */ + + r = dns_transaction_has_unsigned_negative_answer(t); + if (r < 0) + return r; + if (r > 0) { + const char *name; + + name = DNS_RESOURCE_KEY_NAME(t->key); + + /* If this was a SOA or NS request, then this + * indicates that we are not at a zone apex, hence ask + * the parent name instead. If this was a DS request, + * then it's signed when the parent zone is signed, + * hence ask the parent in that case, too. */ + + if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r > 0) + log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); + else + name = NULL; + } else + log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); + + if (name) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; + + soa = dns_resource_key_new(t->key->class, DNS_TYPE_SOA, name); + if (!soa) + return -ENOMEM; + + r = dns_transaction_request_dnssec_rr(t, soa); + if (r < 0) + return r; + } + } + + return dns_transaction_dnssec_is_live(t); +} + +void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { + assert(t); + assert(source); + + /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, + we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If + the state is VALIDATING however, we should check if we are complete now. */ + + if (t->state == DNS_TRANSACTION_VALIDATING) + dns_transaction_process_dnssec(t); +} + +static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { + DnsResourceRecord *rr; + int ifindex, r; + + assert(t); + + /* Add all DNSKEY RRs from the answer that are validated by DS + * RRs from the list of validated keys to the list of + * validated keys. */ + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { + + r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); + if (r < 0) + return r; + if (r == 0) + continue; + + /* If so, the DNSKEY is validated too. */ + r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { + int r; + + assert(t); + assert(rr); + + /* Checks if the RR we are looking for must be signed with an + * RRSIG. This is used for positive responses. */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return false; + + if (dns_type_is_pseudo(rr->key->type)) + return -EINVAL; + + r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + switch (rr->key->type) { + + case DNS_TYPE_RRSIG: + /* RRSIGs are the signatures themselves, they need no signing. */ + return false; + + case DNS_TYPE_SOA: + case DNS_TYPE_NS: { + DnsTransaction *dt; + Iterator i; + + /* For SOA or NS RRs we look for a matching DS transaction */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_DS) + continue; + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found a DS transactions for the SOA/NS + * RRs we are looking at. If it discovered signed DS + * RRs, then we need to be signed, too. */ + + if (!dt->answer_authenticated) + return false; + + return dns_answer_match_key(dt->answer, dt->key, NULL); + } + + /* We found nothing that proves this is safe to leave + * this unauthenticated, hence ask inist on + * authentication. */ + return true; + } + + case DNS_TYPE_DS: + case DNS_TYPE_CNAME: + case DNS_TYPE_DNAME: { + const char *parent = NULL; + DnsTransaction *dt; + Iterator i; + + /* + * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. + * + * DS RRs are signed if the parent is signed, hence also look at the parent SOA + */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_SOA) + continue; + + if (!parent) { + parent = DNS_RESOURCE_KEY_NAME(rr->key); + r = dns_name_parent(&parent); + if (r < 0) + return r; + if (r == 0) { + if (rr->key->type == DNS_TYPE_DS) + return true; + + /* A CNAME/DNAME without a parent? That's sooo weird. */ + log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); + return -EBADMSG; + } + } + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), parent); + if (r < 0) + return r; + if (r == 0) + continue; + + return t->answer_authenticated; + } + + return true; + } + + default: { + DnsTransaction *dt; + Iterator i; + + /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + if (dt->key->type != DNS_TYPE_SOA) + continue; + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found the transaction that was supposed to find + * the SOA RR for us. It was successful, but found no + * RR for us. This means we are not at a zone cut. In + * this case, we require authentication if the SOA + * lookup was authenticated too. */ + return t->answer_authenticated; + } + + return true; + }} +} + +static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { + DnsTransaction *dt; + const char *tld; + Iterator i; + int r; + + /* If DNSSEC downgrade mode is on, checks whether the + * specified RR is one level below a TLD we have proven not to + * exist. In such a case we assume that this is a private + * domain, and permit it. + * + * This detects cases like the Fritz!Box router networks. Each + * Fritz!Box router serves a private "fritz.box" zone, in the + * non-existing TLD "box". Requests for the "fritz.box" domain + * are served by the router itself, while requests for the + * "box" domain will result in NXDOMAIN. + * + * Note that this logic is unable to detect cases where a + * router serves a private DNS zone directly under + * non-existing TLD. In such a case we cannot detect whether + * the TLD is supposed to exist or not, as all requests we + * make for it will be answered by the router's zone, and not + * by the root zone. */ + + assert(t); + + if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) + return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ + + tld = DNS_RESOURCE_KEY_NAME(key); + r = dns_name_parent(&tld); + if (r < 0) + return r; + if (r == 0) + return false; /* Already the root domain */ + + if (!dns_name_is_single_label(tld)) + return false; + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != key->class) + continue; + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), tld); + if (r < 0) + return r; + if (r == 0) + continue; + + /* We found an auxiliary lookup we did for the TLD. If + * that returned with NXDOMAIN, we know the TLD didn't + * exist, and hence this might be a private zone. */ + + return dt->answer_rcode == DNS_RCODE_NXDOMAIN; + } + + return false; +} + +static int dns_transaction_requires_nsec(DnsTransaction *t) { + DnsTransaction *dt; + const char *name; + Iterator i; + int r; + + assert(t); + + /* Checks if we need to insist on NSEC/NSEC3 RRs for proving + * this negative reply */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return false; + + if (dns_type_is_pseudo(t->key->type)) + return -EINVAL; + + r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + r = dns_transaction_in_private_tld(t, t->key); + if (r < 0) + return r; + if (r > 0) { + /* The lookup is from a TLD that is proven not to + * exist, and we are in downgrade mode, hence ignore + * that fact that we didn't get any NSEC RRs.*/ + + log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", dns_transaction_key_string(t)); + return false; + } + + name = DNS_RESOURCE_KEY_NAME(t->key); + + if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { + + /* We got a negative reply for this SOA/NS lookup? If + * so, then we are not at a zone apex, and thus should + * look at the result of the parent SOA lookup. + * + * We got a negative reply for this DS lookup? DS RRs + * are signed when their parent zone is signed, hence + * also check the parent SOA in this case. */ + + r = dns_name_parent(&name); + if (r < 0) + return r; + if (r == 0) + return true; + } + + /* For all other RRs we check the SOA on the same level to see + * if it's signed. */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != t->key->class) + continue; + if (dt->key->type != DNS_TYPE_SOA) + continue; + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), name); + if (r < 0) + return r; + if (r == 0) + continue; + + return dt->answer_authenticated; + } + + /* If in doubt, require NSEC/NSEC3 */ + return true; +} + +static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { + DnsResourceRecord *rrsig; + bool found = false; + int r; + + /* Checks whether any of the DNSKEYs used for the RRSIGs for + * the specified RRset is authenticated (i.e. has a matching + * DS RR). */ + + r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); + if (r < 0) + return r; + if (r > 0) + return false; + + DNS_ANSWER_FOREACH(rrsig, t->answer) { + DnsTransaction *dt; + Iterator i; + + r = dnssec_key_match_rrsig(rr->key, rrsig); + if (r < 0) + return r; + if (r == 0) + continue; + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (dt->key->class != rr->key->class) + continue; + + if (dt->key->type == DNS_TYPE_DNSKEY) { + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + /* OK, we found an auxiliary DNSKEY + * lookup. If that lookup is + * authenticated, report this. */ + + if (dt->answer_authenticated) + return true; + + found = true; + + } else if (dt->key->type == DNS_TYPE_DS) { + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); + if (r < 0) + return r; + if (r == 0) + continue; + + /* OK, we found an auxiliary DS + * lookup. If that lookup is + * authenticated and non-zero, we + * won! */ + + if (!dt->answer_authenticated) + return false; + + return dns_answer_match_key(dt->answer, dt->key, NULL); + } + } + } + + return found ? false : -ENXIO; +} + +static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { + assert(t); + assert(rr); + + /* We know that the root domain is signed, hence if it appears + * not to be signed, there's a problem with the DNS server */ + + return rr->key->class == DNS_CLASS_IN && + dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key)); +} + +static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { + DnsResourceRecord *rr; + int r; + + assert(t); + + /* Maybe warn the user that we encountered a revoked DNSKEY + * for a key from our trust anchor. Note that we don't care + * whether the DNSKEY can be authenticated or not. It's + * sufficient if it is self-signed. */ + + DNS_ANSWER_FOREACH(rr, t->answer) { + r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { + bool changed; + int r; + + assert(t); + + /* Removes all DNSKEY/DS objects from t->validated_keys that + * our trust anchors database considers revoked. */ + + do { + DnsResourceRecord *rr; + + changed = false; + + DNS_ANSWER_FOREACH(rr, t->validated_keys) { + r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); + if (r < 0) + return r; + if (r > 0) { + r = dns_answer_remove_by_rr(&t->validated_keys, rr); + if (r < 0) + return r; + + assert(r > 0); + changed = true; + break; + } + } + } while (changed); + + return 0; +} + +static int dns_transaction_copy_validated(DnsTransaction *t) { + DnsTransaction *dt; + Iterator i; + int r; + + assert(t); + + /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ + + SET_FOREACH(dt, t->dnssec_transactions, i) { + + if (DNS_TRANSACTION_IS_LIVE(dt->state)) + continue; + + if (!dt->answer_authenticated) + continue; + + r = dns_answer_extend(&t->validated_keys, dt->answer); + if (r < 0) + return r; + } + + return 0; +} + +int dns_transaction_validate_dnssec(DnsTransaction *t) { + _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; + enum { + PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ + PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ + PHASE_ALL, /* Phase #3, validate everything else */ + } phase; + DnsResourceRecord *rr; + DnsAnswerFlags flags; + int r; + + assert(t); + + /* We have now collected all DS and DNSKEY RRs in + * t->validated_keys, let's see which RRs we can now + * authenticate with that. */ + + if (t->scope->dnssec_mode == DNSSEC_NO) + return 0; + + /* Already validated */ + if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) + return 0; + + /* Our own stuff needs no validation */ + if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_authenticated = true; + return 0; + } + + /* Cached stuff is not affected by validation. */ + if (t->answer_source != DNS_TRANSACTION_NETWORK) + return 0; + + if (!dns_transaction_dnssec_supported_full(t)) { + /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ + t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; + log_debug("Not validating response, server lacks DNSSEC support."); + return 0; + } + + log_debug("Validating response from transaction %" PRIu16 " (%s).", t->id, dns_transaction_key_string(t)); + + /* First, see if this response contains any revoked trust + * anchors we care about */ + r = dns_transaction_check_revoked_trust_anchors(t); + if (r < 0) + return r; + + /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ + r = dns_transaction_copy_validated(t); + if (r < 0) + return r; + + /* Second, see if there are DNSKEYs we already know a + * validated DS for. */ + r = dns_transaction_validate_dnskey_by_ds(t); + if (r < 0) + return r; + + /* Fourth, remove all DNSKEY and DS RRs again that our trust + * anchor says are revoked. After all we might have marked + * some keys revoked above, but they might still be lingering + * in our validated_keys list. */ + r = dns_transaction_invalidate_revoked_keys(t); + if (r < 0) + return r; + + phase = PHASE_DNSKEY; + for (;;) { + bool changed = false, have_nsec = false; + + DNS_ANSWER_FOREACH(rr, t->answer) { + DnsResourceRecord *rrsig = NULL; + DnssecResult result; + + switch (rr->key->type) { + + case DNS_TYPE_RRSIG: + continue; + + case DNS_TYPE_DNSKEY: + /* We validate DNSKEYs only in the DNSKEY and ALL phases */ + if (phase == PHASE_NSEC) + continue; + break; + + case DNS_TYPE_NSEC: + case DNS_TYPE_NSEC3: + have_nsec = true; + + /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ + if (phase == PHASE_DNSKEY) + continue; + + break; + + default: + /* We validate all other RRs only in the ALL phases */ + if (phase != PHASE_ALL) + continue; + + break; + } + + r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); + if (r < 0) + return r; + + log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); + + if (result == DNSSEC_VALIDATED) { + + if (rr->key->type == DNS_TYPE_DNSKEY) { + /* If we just validated a + * DNSKEY RRset, then let's + * add these keys to the set + * of validated keys for this + * transaction. */ + + r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + /* some of the DNSKEYs we just + * added might already have + * been revoked, remove them + * again in that case. */ + r = dns_transaction_invalidate_revoked_keys(t); + if (r < 0) + return r; + } + + /* Add the validated RRset to the new + * list of validated RRsets, and + * remove it from the unvalidated + * RRsets. We mark the RRset as + * authenticated and cacheable. */ + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); + if (r < 0) + return r; + + t->scope->manager->n_dnssec_secure++; + + /* Exit the loop, we dropped something from the answer, start from the beginning */ + changed = true; + break; + } + + /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as + * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, we + * cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ + if (phase != PHASE_ALL) + continue; + + if (result == DNSSEC_VALIDATED_WILDCARD) { + bool authenticated = false; + const char *source; + + /* This RRset validated, but as a wildcard. This means we need to prove via NSEC/NSEC3 + * that no matching non-wildcard RR exists.*/ + + /* First step, determine the source of synthesis */ + r = dns_resource_record_source(rrsig, &source); + if (r < 0) + return r; + + r = dnssec_test_positive_wildcard( + validated, + DNS_RESOURCE_KEY_NAME(rr->key), + source, + rrsig->rrsig.signer, + &authenticated); + + /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ + if (r == 0) + result = DNSSEC_INVALID; + else { + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); + if (r < 0) + return r; + + if (authenticated) + t->scope->manager->n_dnssec_secure++; + else + t->scope->manager->n_dnssec_insecure++; + + /* Exit the loop, we dropped something from the answer, start from the beginning */ + changed = true; + break; + } + } + + if (result == DNSSEC_NO_SIGNATURE) { + r = dns_transaction_requires_rrsig(t, rr); + if (r < 0) + return r; + if (r == 0) { + /* Data does not require signing. In that case, just copy it over, + * but remember that this is by no means authenticated.*/ + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + t->scope->manager->n_dnssec_insecure++; + changed = true; + break; + } + + r = dns_transaction_known_signed(t, rr); + if (r < 0) + return r; + if (r > 0) { + /* This is an RR we know has to be signed. If it isn't this means + * the server is not attaching RRSIGs, hence complain. */ + + dns_server_packet_rrsig_missing(t->server, t->current_feature_level); + + if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { + + /* Downgrading is OK? If so, just consider the information unsigned */ + + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + t->scope->manager->n_dnssec_insecure++; + changed = true; + break; + } + + /* Otherwise, fail */ + t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; + return 0; + } + + r = dns_transaction_in_private_tld(t, rr->key); + if (r < 0) + return r; + if (r > 0) { + _cleanup_free_ char *s = NULL; + + /* The data is from a TLD that is proven not to exist, and we are in downgrade + * mode, hence ignore the fact that this was not signed. */ + + (void) dns_resource_key_to_string(rr->key, &s); + log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", strna(s ? strstrip(s) : NULL)); + + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + t->scope->manager->n_dnssec_insecure++; + changed = true; + break; + } + } + + if (IN_SET(result, + DNSSEC_MISSING_KEY, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_UNSUPPORTED_ALGORITHM)) { + + r = dns_transaction_dnskey_authenticated(t, rr); + if (r < 0 && r != -ENXIO) + return r; + if (r == 0) { + /* The DNSKEY transaction was not authenticated, this means there's + * no DS for this, which means it's OK if no keys are found for this signature. */ + + r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); + if (r < 0) + return r; + + t->scope->manager->n_dnssec_insecure++; + changed = true; + break; + } + } + + if (IN_SET(result, + DNSSEC_INVALID, + DNSSEC_SIGNATURE_EXPIRED, + DNSSEC_NO_SIGNATURE)) + t->scope->manager->n_dnssec_bogus++; + else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ + t->scope->manager->n_dnssec_indeterminate++; + + r = dns_transaction_is_primary_response(t, rr); + if (r < 0) + return r; + if (r > 0) { + + /* Look for a matching DNAME for this CNAME */ + r = dns_answer_has_dname_for_cname(t->answer, rr); + if (r < 0) + return r; + if (r == 0) { + /* Also look among the stuff we already validated */ + r = dns_answer_has_dname_for_cname(validated, rr); + if (r < 0) + return r; + } + + if (r == 0) { + /* This is a primary response to our question, and it failed validation. That's + * fatal. */ + t->answer_dnssec_result = result; + return 0; + } + + /* This is a primary response, but we do have a DNAME RR in the RR that can replay this + * CNAME, hence rely on that, and we can remove the CNAME in favour of it. */ + } + + /* This is just some auxiliary data. Just remove the RRset and continue. */ + r = dns_answer_remove_by_key(&t->answer, rr->key); + if (r < 0) + return r; + + /* Exit the loop, we dropped something from the answer, start from the beginning */ + changed = true; + break; + } + + /* Restart the inner loop as long as we managed to achieve something */ + if (changed) + continue; + + if (phase == PHASE_DNSKEY && have_nsec) { + /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ + phase = PHASE_NSEC; + continue; + } + + if (phase != PHASE_ALL) { + /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. Note that in this + * third phase we start to remove RRs we couldn't validate. */ + phase = PHASE_ALL; + continue; + } + + /* We're done */ + break; + } + + dns_answer_unref(t->answer); + t->answer = validated; + validated = NULL; + + /* At this point the answer only contains validated + * RRsets. Now, let's see if it actually answers the question + * we asked. If so, great! If it doesn't, then see if + * NSEC/NSEC3 can prove this. */ + r = dns_transaction_has_positive_answer(t, &flags); + if (r > 0) { + /* Yes, it answers the question! */ + + if (flags & DNS_ANSWER_AUTHENTICATED) { + /* The answer is fully authenticated, yay. */ + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_authenticated = true; + } else { + /* The answer is not fully authenticated. */ + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + } + + } else if (r == 0) { + DnssecNsecResult nr; + bool authenticated = false; + + /* Bummer! Let's check NSEC/NSEC3 */ + r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); + if (r < 0) + return r; + + switch (nr) { + + case DNSSEC_NSEC_NXDOMAIN: + /* NSEC proves the domain doesn't exist. Very good. */ + log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_NXDOMAIN; + t->answer_authenticated = authenticated; + break; + + case DNSSEC_NSEC_NODATA: + /* NSEC proves that there's no data here, very good. */ + log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); + t->answer_dnssec_result = DNSSEC_VALIDATED; + t->answer_rcode = DNS_RCODE_SUCCESS; + t->answer_authenticated = authenticated; + break; + + case DNSSEC_NSEC_OPTOUT: + /* NSEC3 says the data might not be signed */ + log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + break; + + case DNSSEC_NSEC_NO_RR: + /* No NSEC data? Bummer! */ + + r = dns_transaction_requires_nsec(t); + if (r < 0) + return r; + if (r > 0) + t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; + else { + t->answer_dnssec_result = DNSSEC_UNSIGNED; + t->answer_authenticated = false; + } + + break; + + case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: + /* We don't know the NSEC3 algorithm used? */ + t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; + break; + + case DNSSEC_NSEC_FOUND: + case DNSSEC_NSEC_CNAME: + /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ + t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; + break; + + default: + assert_not_reached("Unexpected NSEC result."); + } + } + + return 1; +} + +const char *dns_transaction_key_string(DnsTransaction *t) { + assert(t); + + if (!t->key_string) { + if (dns_resource_key_to_string(t->key, &t->key_string) < 0) + return "n/a"; + } + + return strstrip(t->key_string); +} + static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { [DNS_TRANSACTION_NULL] = "null", [DNS_TRANSACTION_PENDING] = "pending", - [DNS_TRANSACTION_FAILURE] = "failure", + [DNS_TRANSACTION_VALIDATING] = "validating", + [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", [DNS_TRANSACTION_SUCCESS] = "success", [DNS_TRANSACTION_NO_SERVERS] = "no-servers", [DNS_TRANSACTION_TIMEOUT] = "timeout", @@ -741,5 +2966,16 @@ static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", [DNS_TRANSACTION_RESOURCES] = "resources", [DNS_TRANSACTION_ABORTED] = "aborted", + [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", + [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", + [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", }; DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); + +static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { + [DNS_TRANSACTION_NETWORK] = "network", + [DNS_TRANSACTION_CACHE] = "cache", + [DNS_TRANSACTION_ZONE] = "zone", + [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", +}; +DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h index acf6a6f651..76cf6e71db 100644 --- a/src/resolve/resolved-dns-transaction.h +++ b/src/resolve/resolved-dns-transaction.h @@ -23,11 +23,13 @@ typedef struct DnsTransaction DnsTransaction; typedef enum DnsTransactionState DnsTransactionState; +typedef enum DnsTransactionSource DnsTransactionSource; enum DnsTransactionState { DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, - DNS_TRANSACTION_FAILURE, + DNS_TRANSACTION_VALIDATING, + DNS_TRANSACTION_RCODE_FAILURE, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NO_SERVERS, DNS_TRANSACTION_TIMEOUT, @@ -35,49 +37,102 @@ enum DnsTransactionState { DNS_TRANSACTION_INVALID_REPLY, DNS_TRANSACTION_RESOURCES, DNS_TRANSACTION_ABORTED, + DNS_TRANSACTION_DNSSEC_FAILED, + DNS_TRANSACTION_NO_TRUST_ANCHOR, + DNS_TRANSACTION_RR_TYPE_UNSUPPORTED, _DNS_TRANSACTION_STATE_MAX, _DNS_TRANSACTION_STATE_INVALID = -1 }; -#include "resolved-dns-scope.h" +#define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING) + +enum DnsTransactionSource { + DNS_TRANSACTION_NETWORK, + DNS_TRANSACTION_CACHE, + DNS_TRANSACTION_ZONE, + DNS_TRANSACTION_TRUST_ANCHOR, + _DNS_TRANSACTION_SOURCE_MAX, + _DNS_TRANSACTION_SOURCE_INVALID = -1 +}; + +#include "resolved-dns-answer.h" #include "resolved-dns-packet.h" #include "resolved-dns-question.h" -#include "resolved-dns-answer.h" +#include "resolved-dns-scope.h" struct DnsTransaction { DnsScope *scope; DnsResourceKey *key; + char *key_string; DnsTransactionState state; + uint16_t id; - bool initial_jitter; + bool tried_stream:1; + + bool initial_jitter_scheduled:1; + bool initial_jitter_elapsed:1; DnsPacket *sent, *received; - DnsAnswer *cached; - int cached_rcode; + + DnsAnswer *answer; + int answer_rcode; + DnssecResult answer_dnssec_result; + DnsTransactionSource answer_source; + uint32_t answer_nsec_ttl; + + /* Indicates whether the primary answer is authenticated, + * i.e. whether the RRs from answer which directly match the + * question are authenticated, or, if there are none, whether + * the NODATA or NXDOMAIN case is. It says nothing about + * additional RRs listed in the answer, however they have + * their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit + * is defined different than the AD bit in DNS packets, as + * that covers more than just the actual primary answer. */ + bool answer_authenticated; + + /* Contains DNSKEY, DS, SOA RRs we already verified and need + * to authenticate this reply */ + DnsAnswer *validated_keys; usec_t start_usec; + usec_t next_attempt_after; sd_event_source *timeout_event_source; unsigned n_attempts; + /* UDP connection logic, if we need it */ int dns_udp_fd; sd_event_source *dns_udp_event_source; + /* TCP connection logic, if we need it */ + DnsStream *stream; + /* The active server */ DnsServer *server; - /* TCP connection logic, if we need it */ - DnsStream *stream; + /* The features of the DNS server at time of transaction start */ + DnsServerFeatureLevel current_feature_level; - /* Queries this transaction is referenced by and that shall be - * notified about this specific transaction completing. */ - Set *queries; + /* Query candidates this transaction is referenced by and that + * shall be notified about this specific transaction + * completing. */ + Set *notify_query_candidates; /* Zone items this transaction is referenced by and that shall * be notified about completion. */ - Set *zone_items; + Set *notify_zone_items; + + /* Other transactions that this transactions is referenced by + * and that shall be notified about completion. This is used + * when transactions want to validate their RRsets, but need + * another DNSKEY or DS RR to do so. */ + Set *notify_transactions; + + /* The opposite direction: the transactions this transaction + * created in order to request DNSKEY or DS RRs. */ + Set *dnssec_transactions; unsigned block_gc; @@ -87,22 +142,35 @@ struct DnsTransaction { int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key); DnsTransaction* dns_transaction_free(DnsTransaction *t); -void dns_transaction_gc(DnsTransaction *t); +bool dns_transaction_gc(DnsTransaction *t); int dns_transaction_go(DnsTransaction *t); void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p); void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state); +void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source); +int dns_transaction_validate_dnssec(DnsTransaction *t); +int dns_transaction_request_dnssec_keys(DnsTransaction *t); + +const char *dns_transaction_key_string(DnsTransaction *t); + const char* dns_transaction_state_to_string(DnsTransactionState p) _const_; DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_; +const char* dns_transaction_source_to_string(DnsTransactionSource p) _const_; +DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_; + /* LLMNR Jitter interval, see RFC 4795 Section 7 */ #define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC) +/* mDNS Jitter interval, see RFC 6762 Section 5.2 */ +#define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC) +#define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC) + /* Maximum attempts to send DNS requests, across all DNS servers */ #define DNS_TRANSACTION_ATTEMPTS_MAX 16 /* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ #define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 -#define TRANSACTION_ATTEMPTS_MAX(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX) +#define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX) diff --git a/src/resolve/resolved-dns-trust-anchor.c b/src/resolve/resolved-dns-trust-anchor.c new file mode 100644 index 0000000000..02d7ac91e1 --- /dev/null +++ b/src/resolve/resolved-dns-trust-anchor.c @@ -0,0 +1,745 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <sd-messages.h> + +#include "alloc-util.h" +#include "conf-files.h" +#include "def.h" +#include "dns-domain.h" +#include "fd-util.h" +#include "fileio.h" +#include "hexdecoct.h" +#include "parse-util.h" +#include "resolved-dns-trust-anchor.h" +#include "resolved-dns-dnssec.h" +#include "set.h" +#include "string-util.h" +#include "strv.h" + +static const char trust_anchor_dirs[] = CONF_PATHS_NULSTR("dnssec-trust-anchors.d"); + +/* The DS RR from https://data.iana.org/root-anchors/root-anchors.xml, retrieved December 2015 */ +static const uint8_t root_digest[] = + { 0x49, 0xAA, 0xC1, 0x1D, 0x7B, 0x6F, 0x64, 0x46, 0x70, 0x2E, 0x54, 0xA1, 0x60, 0x73, 0x71, 0x60, + 0x7A, 0x1A, 0x41, 0x85, 0x52, 0x00, 0xFD, 0x2C, 0xE1, 0xCD, 0xDE, 0x32, 0xF2, 0x4E, 0x8F, 0xB5 }; + +static bool dns_trust_anchor_knows_domain_positive(DnsTrustAnchor *d, const char *name) { + assert(d); + + /* Returns true if there's an entry for the specified domain + * name in our trust anchor */ + + return + hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DNSKEY, name)) || + hashmap_contains(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(DNS_CLASS_IN, DNS_TYPE_DS, name)); +} + +static int dns_trust_anchor_add_builtin_positive(DnsTrustAnchor *d) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; + + assert(d); + + r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); + if (r < 0) + return r; + + /* Only add the built-in trust anchor if there's neither a DS + * nor a DNSKEY defined for the root domain. That way users + * have an easy way to override the root domain DS/DNSKEY + * data. */ + if (dns_trust_anchor_knows_domain_positive(d, ".")) + return 0; + + /* Add the RR from https://data.iana.org/root-anchors/root-anchors.xml */ + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, ""); + if (!rr) + return -ENOMEM; + + rr->ds.key_tag = 19036; + rr->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rr->ds.digest_type = DNSSEC_DIGEST_SHA256; + rr->ds.digest_size = sizeof(root_digest); + rr->ds.digest = memdup(root_digest, rr->ds.digest_size); + if (!rr->ds.digest) + return -ENOMEM; + + answer = dns_answer_new(1); + if (!answer) + return -ENOMEM; + + r = dns_answer_add(answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + + r = hashmap_put(d->positive_by_key, rr->key, answer); + if (r < 0) + return r; + + answer = NULL; + return 0; +} + +static int dns_trust_anchor_add_builtin_negative(DnsTrustAnchor *d) { + + static const char private_domains[] = + /* RFC 6761 says that .test is a special domain for + * testing and not to be installed in the root zone */ + "test\0" + + /* RFC 6761 says that these reverse IP lookup ranges + * are for private addresses, and hence should not + * show up in the root zone */ + "10.in-addr.arpa\0" + "16.172.in-addr.arpa\0" + "17.172.in-addr.arpa\0" + "18.172.in-addr.arpa\0" + "19.172.in-addr.arpa\0" + "20.172.in-addr.arpa\0" + "21.172.in-addr.arpa\0" + "22.172.in-addr.arpa\0" + "23.172.in-addr.arpa\0" + "24.172.in-addr.arpa\0" + "25.172.in-addr.arpa\0" + "26.172.in-addr.arpa\0" + "27.172.in-addr.arpa\0" + "28.172.in-addr.arpa\0" + "29.172.in-addr.arpa\0" + "30.172.in-addr.arpa\0" + "31.172.in-addr.arpa\0" + "168.192.in-addr.arpa\0" + + /* RFC 6762 reserves the .local domain for Multicast + * DNS, it hence cannot appear in the root zone. (Note + * that we by default do not route .local traffic to + * DNS anyway, except when a configured search domain + * suggests so.) */ + "local\0" + + /* These two are well known, popular private zone + * TLDs, that are blocked from delegation, according + * to: + * http://icannwiki.com/Name_Collision#NGPC_Resolution + * + * There's also ongoing work on making this official + * in an RRC: + * https://www.ietf.org/archive/id/draft-chapin-additional-reserved-tlds-02.txt */ + "home\0" + "corp\0" + + /* The following four TLDs are suggested for private + * zones in RFC 6762, Appendix G, and are hence very + * unlikely to be made official TLDs any day soon */ + "lan\0" + "intranet\0" + "internal\0" + "private\0"; + + const char *name; + int r; + + assert(d); + + /* Only add the built-in trust anchor if there's no negative + * trust anchor defined at all. This enables easy overriding + * of negative trust anchors. */ + + if (set_size(d->negative_by_name) > 0) + return 0; + + r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); + if (r < 0) + return r; + + /* We add a couple of domains as default negative trust + * anchors, where it's very unlikely they will be installed in + * the root zone. If they exist they must be private, and thus + * unsigned. */ + + NULSTR_FOREACH(name, private_domains) { + + if (dns_trust_anchor_knows_domain_positive(d, name)) + continue; + + r = set_put_strdup(d->negative_by_name, name); + if (r < 0) + return r; + } + + return 0; +} + +static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + _cleanup_free_ char *domain = NULL, *class = NULL, *type = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnsAnswer *old_answer = NULL; + const char *p = s; + int r; + + assert(d); + assert(line); + + r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); + if (r < 0) + return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line); + + if (!dns_name_is_valid(domain)) { + log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); + return -EINVAL; + } + + r = extract_many_words(&p, NULL, 0, &class, &type, NULL); + if (r < 0) + return log_warning_errno(r, "Unable to parse class and type in line %s:%u: %m", path, line); + if (r != 2) { + log_warning("Missing class or type in line %s:%u", path, line); + return -EINVAL; + } + + if (!strcaseeq(class, "IN")) { + log_warning("RR class %s is not supported, ignoring line %s:%u.", class, path, line); + return -EINVAL; + } + + if (strcaseeq(type, "DS")) { + _cleanup_free_ char *key_tag = NULL, *algorithm = NULL, *digest_type = NULL, *digest = NULL; + _cleanup_free_ void *dd = NULL; + uint16_t kt; + int a, dt; + size_t l; + + r = extract_many_words(&p, NULL, 0, &key_tag, &algorithm, &digest_type, &digest, NULL); + if (r < 0) { + log_warning_errno(r, "Failed to parse DS parameters on line %s:%u: %m", path, line); + return -EINVAL; + } + if (r != 4) { + log_warning("Missing DS parameters on line %s:%u", path, line); + return -EINVAL; + } + + r = safe_atou16(key_tag, &kt); + if (r < 0) + return log_warning_errno(r, "Failed to parse DS key tag %s on line %s:%u: %m", key_tag, path, line); + + a = dnssec_algorithm_from_string(algorithm); + if (a < 0) { + log_warning("Failed to parse DS algorithm %s on line %s:%u", algorithm, path, line); + return -EINVAL; + } + + dt = dnssec_digest_from_string(digest_type); + if (dt < 0) { + log_warning("Failed to parse DS digest type %s on line %s:%u", digest_type, path, line); + return -EINVAL; + } + + r = unhexmem(digest, strlen(digest), &dd, &l); + if (r < 0) { + log_warning("Failed to parse DS digest %s on line %s:%u", digest, path, line); + return -EINVAL; + } + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, domain); + if (!rr) + return log_oom(); + + rr->ds.key_tag = kt; + rr->ds.algorithm = a; + rr->ds.digest_type = dt; + rr->ds.digest_size = l; + rr->ds.digest = dd; + dd = NULL; + + } else if (strcaseeq(type, "DNSKEY")) { + _cleanup_free_ char *flags = NULL, *protocol = NULL, *algorithm = NULL, *key = NULL; + _cleanup_free_ void *k = NULL; + uint16_t f; + size_t l; + int a; + + r = extract_many_words(&p, NULL, 0, &flags, &protocol, &algorithm, &key, NULL); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY parameters on line %s:%u: %m", path, line); + if (r != 4) { + log_warning("Missing DNSKEY parameters on line %s:%u", path, line); + return -EINVAL; + } + + if (!streq(protocol, "3")) { + log_warning("DNSKEY Protocol is not 3 on line %s:%u", path, line); + return -EINVAL; + } + + r = safe_atou16(flags, &f); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY flags field %s on line %s:%u", flags, path, line); + if ((f & DNSKEY_FLAG_ZONE_KEY) == 0) { + log_warning("DNSKEY lacks zone key bit set on line %s:%u", path, line); + return -EINVAL; + } + if ((f & DNSKEY_FLAG_REVOKE)) { + log_warning("DNSKEY is already revoked on line %s:%u", path, line); + return -EINVAL; + } + + a = dnssec_algorithm_from_string(algorithm); + if (a < 0) { + log_warning("Failed to parse DNSKEY algorithm %s on line %s:%u", algorithm, path, line); + return -EINVAL; + } + + r = unbase64mem(key, strlen(key), &k, &l); + if (r < 0) + return log_warning_errno(r, "Failed to parse DNSKEY key data %s on line %s:%u", key, path, line); + + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, domain); + if (!rr) + return log_oom(); + + rr->dnskey.flags = f; + rr->dnskey.protocol = 3; + rr->dnskey.algorithm = a; + rr->dnskey.key_size = l; + rr->dnskey.key = k; + k = NULL; + + } else { + log_warning("RR type %s is not supported, ignoring line %s:%u.", type, path, line); + return -EINVAL; + } + + if (!isempty(p)) { + log_warning("Trailing garbage on line %s:%u, ignoring line.", path, line); + return -EINVAL; + } + + r = hashmap_ensure_allocated(&d->positive_by_key, &dns_resource_key_hash_ops); + if (r < 0) + return log_oom(); + + old_answer = hashmap_get(d->positive_by_key, rr->key); + answer = dns_answer_ref(old_answer); + + r = dns_answer_add_extend(&answer, rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return log_error_errno(r, "Failed to add trust anchor RR: %m"); + + r = hashmap_replace(d->positive_by_key, rr->key, answer); + if (r < 0) + return log_error_errno(r, "Failed to add answer to trust anchor: %m"); + + old_answer = dns_answer_unref(old_answer); + answer = NULL; + + return 0; +} + +static int dns_trust_anchor_load_negative(DnsTrustAnchor *d, const char *path, unsigned line, const char *s) { + _cleanup_free_ char *domain = NULL; + const char *p = s; + int r; + + assert(d); + assert(line); + + r = extract_first_word(&p, &domain, NULL, EXTRACT_QUOTES); + if (r < 0) + return log_warning_errno(r, "Unable to parse line %s:%u: %m", path, line); + + if (!dns_name_is_valid(domain)) { + log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line); + return -EINVAL; + } + + if (!isempty(p)) { + log_warning("Trailing garbage at line %s:%u, ignoring line.", path, line); + return -EINVAL; + } + + r = set_ensure_allocated(&d->negative_by_name, &dns_name_hash_ops); + if (r < 0) + return log_oom(); + + r = set_put(d->negative_by_name, domain); + if (r < 0) + return log_oom(); + if (r > 0) + domain = NULL; + + return 0; +} + +static int dns_trust_anchor_load_files( + DnsTrustAnchor *d, + const char *suffix, + int (*loader)(DnsTrustAnchor *d, const char *path, unsigned n, const char *line)) { + + _cleanup_strv_free_ char **files = NULL; + char **f; + int r; + + assert(d); + assert(suffix); + assert(loader); + + r = conf_files_list_nulstr(&files, suffix, NULL, trust_anchor_dirs); + if (r < 0) + return log_error_errno(r, "Failed to enumerate %s trust anchor files: %m", suffix); + + STRV_FOREACH(f, files) { + _cleanup_fclose_ FILE *g = NULL; + char line[LINE_MAX]; + unsigned n = 0; + + g = fopen(*f, "r"); + if (!g) { + if (errno == ENOENT) + continue; + + log_warning_errno(errno, "Failed to open %s: %m", *f); + continue; + } + + FOREACH_LINE(line, g, log_warning_errno(errno, "Failed to read %s, ignoring: %m", *f)) { + char *l; + + n++; + + l = strstrip(line); + if (isempty(l)) + continue; + + if (*l == ';') + continue; + + (void) loader(d, *f, n, l); + } + } + + return 0; +} + +static int domain_name_cmp(const void *a, const void *b) { + char **x = (char**) a, **y = (char**) b; + + return dns_name_compare_func(*x, *y); +} + +static int dns_trust_anchor_dump(DnsTrustAnchor *d) { + DnsAnswer *a; + Iterator i; + + assert(d); + + if (hashmap_isempty(d->positive_by_key)) + log_info("No positive trust anchors defined."); + else { + log_info("Positive Trust Anchors:"); + HASHMAP_FOREACH(a, d->positive_by_key, i) { + DnsResourceRecord *rr; + + DNS_ANSWER_FOREACH(rr, a) + log_info("%s", dns_resource_record_to_string(rr)); + } + } + + if (set_isempty(d->negative_by_name)) + log_info("No negative trust anchors defined."); + else { + _cleanup_free_ char **l = NULL, *j = NULL; + + l = set_get_strv(d->negative_by_name); + if (!l) + return log_oom(); + + qsort_safe(l, set_size(d->negative_by_name), sizeof(char*), domain_name_cmp); + + j = strv_join(l, " "); + if (!j) + return log_oom(); + + log_info("Negative trust anchors: %s", j); + } + + return 0; +} + +int dns_trust_anchor_load(DnsTrustAnchor *d) { + int r; + + assert(d); + + /* If loading things from disk fails, we don't consider this fatal */ + (void) dns_trust_anchor_load_files(d, ".positive", dns_trust_anchor_load_positive); + (void) dns_trust_anchor_load_files(d, ".negative", dns_trust_anchor_load_negative); + + /* However, if the built-in DS fails, then we have a problem. */ + r = dns_trust_anchor_add_builtin_positive(d); + if (r < 0) + return log_error_errno(r, "Failed to add built-in positive trust anchor: %m"); + + r = dns_trust_anchor_add_builtin_negative(d); + if (r < 0) + return log_error_errno(r, "Failed to add built-in negative trust anchor: %m"); + + dns_trust_anchor_dump(d); + + return 0; +} + +void dns_trust_anchor_flush(DnsTrustAnchor *d) { + DnsAnswer *a; + DnsResourceRecord *rr; + + assert(d); + + while ((a = hashmap_steal_first(d->positive_by_key))) + dns_answer_unref(a); + d->positive_by_key = hashmap_free(d->positive_by_key); + + while ((rr = set_steal_first(d->revoked_by_rr))) + dns_resource_record_unref(rr); + d->revoked_by_rr = set_free(d->revoked_by_rr); + + d->negative_by_name = set_free_free(d->negative_by_name); +} + +int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey *key, DnsAnswer **ret) { + DnsAnswer *a; + + assert(d); + assert(key); + assert(ret); + + /* We only serve DS and DNSKEY RRs. */ + if (!IN_SET(key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) + return 0; + + a = hashmap_get(d->positive_by_key, key); + if (!a) + return 0; + + *ret = dns_answer_ref(a); + return 1; +} + +int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name) { + assert(d); + assert(name); + + return set_contains(d->negative_by_name, name); +} + +static int dns_trust_anchor_revoked_put(DnsTrustAnchor *d, DnsResourceRecord *rr) { + int r; + + assert(d); + + r = set_ensure_allocated(&d->revoked_by_rr, &dns_resource_record_hash_ops); + if (r < 0) + return r; + + r = set_put(d->revoked_by_rr, rr); + if (r < 0) + return r; + if (r > 0) + dns_resource_record_ref(rr); + + return r; +} + +static int dns_trust_anchor_remove_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { + _cleanup_(dns_answer_unrefp) DnsAnswer *new_answer = NULL; + DnsAnswer *old_answer; + int r; + + /* Remember that this is a revoked trust anchor RR */ + r = dns_trust_anchor_revoked_put(d, rr); + if (r < 0) + return r; + + /* Remove this from the positive trust anchor */ + old_answer = hashmap_get(d->positive_by_key, rr->key); + if (!old_answer) + return 0; + + new_answer = dns_answer_ref(old_answer); + + r = dns_answer_remove_by_rr(&new_answer, rr); + if (r <= 0) + return r; + + /* We found the key! Warn the user */ + log_struct(LOG_WARNING, + LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_TRUST_ANCHOR_REVOKED), + LOG_MESSAGE("DNSSEC Trust anchor %s has been revoked. Please update the trust anchor, or upgrade your operating system."), strna(dns_resource_record_to_string(rr)), + "TRUST_ANCHOR=%s", dns_resource_record_to_string(rr), + NULL); + + if (dns_answer_size(new_answer) <= 0) { + assert_se(hashmap_remove(d->positive_by_key, rr->key) == old_answer); + dns_answer_unref(old_answer); + return 1; + } + + r = hashmap_replace(d->positive_by_key, new_answer->items[0].rr->key, new_answer); + if (r < 0) + return r; + + new_answer = NULL; + dns_answer_unref(old_answer); + return 1; +} + +static int dns_trust_anchor_check_revoked_one(DnsTrustAnchor *d, DnsResourceRecord *revoked_dnskey) { + DnsAnswer *a; + int r; + + assert(d); + assert(revoked_dnskey); + assert(revoked_dnskey->key->type == DNS_TYPE_DNSKEY); + assert(revoked_dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE); + + a = hashmap_get(d->positive_by_key, revoked_dnskey->key); + if (a) { + DnsResourceRecord *anchor; + + /* First, look for the precise DNSKEY in our trust anchor database */ + + DNS_ANSWER_FOREACH(anchor, a) { + + if (anchor->dnskey.protocol != revoked_dnskey->dnskey.protocol) + continue; + + if (anchor->dnskey.algorithm != revoked_dnskey->dnskey.algorithm) + continue; + + if (anchor->dnskey.key_size != revoked_dnskey->dnskey.key_size) + continue; + + /* Note that we allow the REVOKE bit to be + * different! It will be set in the revoked + * key, but unset in our version of it */ + if (((anchor->dnskey.flags ^ revoked_dnskey->dnskey.flags) | DNSKEY_FLAG_REVOKE) != DNSKEY_FLAG_REVOKE) + continue; + + if (memcmp(anchor->dnskey.key, revoked_dnskey->dnskey.key, anchor->dnskey.key_size) != 0) + continue; + + dns_trust_anchor_remove_revoked(d, anchor); + break; + } + } + + a = hashmap_get(d->positive_by_key, &DNS_RESOURCE_KEY_CONST(revoked_dnskey->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(revoked_dnskey->key))); + if (a) { + DnsResourceRecord *anchor; + + /* Second, look for DS RRs matching this DNSKEY in our trust anchor database */ + + DNS_ANSWER_FOREACH(anchor, a) { + + /* We set mask_revoke to true here, since our + * DS fingerprint will be the one of the + * unrevoked DNSKEY, but the one we got passed + * here has the bit set. */ + r = dnssec_verify_dnskey_by_ds(revoked_dnskey, anchor, true); + if (r < 0) + return r; + if (r == 0) + continue; + + dns_trust_anchor_remove_revoked(d, anchor); + break; + } + } + + return 0; +} + +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs) { + DnsResourceRecord *rrsig; + int r; + + assert(d); + assert(dnskey); + + /* Looks if "dnskey" is a self-signed RR that has been revoked + * and matches one of our trust anchor entries. If so, removes + * it from the trust anchor and returns > 0. */ + + if (dnskey->key->type != DNS_TYPE_DNSKEY) + return 0; + + /* Is this DNSKEY revoked? */ + if ((dnskey->dnskey.flags & DNSKEY_FLAG_REVOKE) == 0) + return 0; + + /* Could this be interesting to us at all? If not, + * there's no point in looking for and verifying a + * self-signed RRSIG. */ + if (!dns_trust_anchor_knows_domain_positive(d, DNS_RESOURCE_KEY_NAME(dnskey->key))) + return 0; + + /* Look for a self-signed RRSIG in the other rrs belonging to this DNSKEY */ + DNS_ANSWER_FOREACH(rrsig, rrs) { + DnssecResult result; + + if (rrsig->key->type != DNS_TYPE_RRSIG) + continue; + + r = dnssec_rrsig_match_dnskey(rrsig, dnskey, true); + if (r < 0) + return r; + if (r == 0) + continue; + + r = dnssec_verify_rrset(rrs, dnskey->key, rrsig, dnskey, USEC_INFINITY, &result); + if (r < 0) + return r; + if (result != DNSSEC_VALIDATED) + continue; + + /* Bingo! This is a revoked self-signed DNSKEY. Let's + * see if this precise one exists in our trust anchor + * database, too. */ + r = dns_trust_anchor_check_revoked_one(d, dnskey); + if (r < 0) + return r; + + return 1; + } + + return 0; +} + +int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr) { + assert(d); + + if (!IN_SET(rr->key->type, DNS_TYPE_DS, DNS_TYPE_DNSKEY)) + return 0; + + return set_contains(d->revoked_by_rr, rr); +} diff --git a/src/resolve/resolved-dns-trust-anchor.h b/src/resolve/resolved-dns-trust-anchor.h new file mode 100644 index 0000000000..5d137faae1 --- /dev/null +++ b/src/resolve/resolved-dns-trust-anchor.h @@ -0,0 +1,45 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +typedef struct DnsTrustAnchor DnsTrustAnchor; + +#include "hashmap.h" +#include "resolved-dns-answer.h" +#include "resolved-dns-rr.h" + +/* This contains a fixed database mapping domain names to DS or DNSKEY records. */ + +struct DnsTrustAnchor { + Hashmap *positive_by_key; + Set *negative_by_name; + Set *revoked_by_rr; +}; + +int dns_trust_anchor_load(DnsTrustAnchor *d); +void dns_trust_anchor_flush(DnsTrustAnchor *d); + +int dns_trust_anchor_lookup_positive(DnsTrustAnchor *d, const DnsResourceKey* key, DnsAnswer **answer); +int dns_trust_anchor_lookup_negative(DnsTrustAnchor *d, const char *name); + +int dns_trust_anchor_check_revoked(DnsTrustAnchor *d, DnsResourceRecord *dnskey, DnsAnswer *rrs); +int dns_trust_anchor_is_revoked(DnsTrustAnchor *d, DnsResourceRecord *rr); diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c index 8a59bd1c3c..f60b0bddc1 100644 --- a/src/resolve/resolved-dns-zone.c +++ b/src/resolve/resolved-dns-zone.c @@ -19,11 +19,12 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "list.h" - -#include "resolved-dns-zone.h" +#include "alloc-util.h" #include "dns-domain.h" +#include "list.h" #include "resolved-dns-packet.h" +#include "resolved-dns-zone.h" +#include "string-util.h" /* Never allow more than 1K entries */ #define ZONE_MAX 1024 @@ -38,7 +39,7 @@ void dns_zone_item_probe_stop(DnsZoneItem *i) { t = i->probe_transaction; i->probe_transaction = NULL; - set_remove(t->zone_items, i); + set_remove(t->notify_zone_items, i); dns_transaction_gc(t); } @@ -162,7 +163,6 @@ static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) { } static int dns_zone_item_probe_start(DnsZoneItem *i) { - _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; DnsTransaction *t; int r; @@ -171,22 +171,24 @@ static int dns_zone_item_probe_start(DnsZoneItem *i) { if (i->probe_transaction) return 0; - key = dns_resource_key_new(i->rr->key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(i->rr->key)); - if (!key) - return -ENOMEM; - - t = dns_scope_find_transaction(i->scope, key, false); + t = dns_scope_find_transaction(i->scope, &DNS_RESOURCE_KEY_CONST(i->rr->key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(i->rr->key)), false); if (!t) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; + + key = dns_resource_key_new(i->rr->key->class, DNS_TYPE_ANY, DNS_RESOURCE_KEY_NAME(i->rr->key)); + if (!key) + return -ENOMEM; + r = dns_transaction_new(&t, i->scope, key); if (r < 0) return r; } - r = set_ensure_allocated(&t->zone_items, NULL); + r = set_ensure_allocated(&t->notify_zone_items, NULL); if (r < 0) goto gc; - r = set_put(t->zone_items, i); + r = set_put(t->notify_zone_items, i); if (r < 0) goto gc; @@ -204,7 +206,7 @@ static int dns_zone_item_probe_start(DnsZoneItem *i) { } } - dns_zone_item_ready(i); + dns_zone_item_notify(i); return 0; gc: @@ -221,9 +223,9 @@ int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe) { assert(s); assert(rr); - if (rr->key->class == DNS_CLASS_ANY) + if (dns_class_is_pseudo(rr->key->class)) return -EINVAL; - if (rr->key->type == DNS_TYPE_ANY) + if (dns_type_is_pseudo(rr->key->type)) return -EINVAL; existing = dns_zone_get(z, rr); @@ -282,97 +284,76 @@ int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe) { return 0; } -int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswer **ret_soa, bool *ret_tentative) { +int dns_zone_lookup(DnsZone *z, DnsResourceKey *key, DnsAnswer **ret_answer, DnsAnswer **ret_soa, bool *ret_tentative) { _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; - unsigned i, n_answer = 0, n_soa = 0; - bool tentative = true; + unsigned n_answer = 0; + DnsZoneItem *j, *first; + bool tentative = true, need_soa = false; int r; assert(z); - assert(q); + assert(key); assert(ret_answer); - assert(ret_soa); - - if (q->n_keys <= 0) { - *ret_answer = NULL; - *ret_soa = NULL; - if (ret_tentative) - *ret_tentative = false; + /* First iteration, count what we have */ - return 0; - } + if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { + bool found = false, added = false; + int k; - /* First iteration, count what we have */ - for (i = 0; i < q->n_keys; i++) { - DnsZoneItem *j, *first; + /* If this is a generic match, then we have to + * go through the list by the name and look + * for everything manually */ - if (q->keys[i]->type == DNS_TYPE_ANY || - q->keys[i]->class == DNS_CLASS_ANY) { - bool found = false, added = false; - int k; + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; - /* If this is a generic match, then we have to - * go through the list by the name and look - * for everything manually */ + found = true; - first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, first) { - if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) - continue; + k = dns_resource_key_match_rr(key, j->rr, NULL); + if (k < 0) + return k; + if (k > 0) { + n_answer++; + added = true; + } - found = true; + } - k = dns_resource_key_match_rr(q->keys[i], j->rr); - if (k < 0) - return k; - if (k > 0) { - n_answer++; - added = true; - } + if (found && !added) + need_soa = true; - } + } else { + bool found = false; - if (found && !added) - n_soa++; + /* If this is a specific match, then look for + * the right key immediately */ - } else { - bool found = false; + first = hashmap_get(z->by_key, key); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; - /* If this is a specific match, then look for - * the right key immediately */ + found = true; + n_answer++; + } - first = hashmap_get(z->by_key, q->keys[i]); - LIST_FOREACH(by_key, j, first) { + if (!found) { + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(key)); + LIST_FOREACH(by_name, j, first) { if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) continue; - found = true; - n_answer++; - } - - if (!found) { - first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, first) { - if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) - continue; - - n_soa++; - break; - } + need_soa = true; + break; } } } - if (n_answer <= 0 && n_soa <= 0) { - *ret_answer = NULL; - *ret_soa = NULL; - - if (ret_tentative) - *ret_tentative = false; - - return 0; - } + if (n_answer <= 0 && !need_soa) + goto return_empty; if (n_answer > 0) { answer = dns_answer_new(n_answer); @@ -380,111 +361,122 @@ int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret_answer, DnsAnswe return -ENOMEM; } - if (n_soa > 0) { - soa = dns_answer_new(n_soa); + if (need_soa) { + soa = dns_answer_new(1); if (!soa) return -ENOMEM; } /* Second iteration, actually add the RRs to the answers */ - for (i = 0; i < q->n_keys; i++) { - DnsZoneItem *j, *first; - - if (q->keys[i]->type == DNS_TYPE_ANY || - q->keys[i]->class == DNS_CLASS_ANY) { - bool found = false, added = false; - int k; - - first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, first) { - if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) - continue; - - found = true; + if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) { + bool found = false, added = false; + int k; - if (j->state != DNS_ZONE_ITEM_PROBING) - tentative = false; + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; - k = dns_resource_key_match_rr(q->keys[i], j->rr); - if (k < 0) - return k; - if (k > 0) { - r = dns_answer_add(answer, j->rr, 0); - if (r < 0) - return r; + found = true; - added = true; - } - } + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; - if (found && !added) { - r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(q->keys[i]), LLMNR_DEFAULT_TTL); + k = dns_resource_key_match_rr(key, j->rr, NULL); + if (k < 0) + return k; + if (k > 0) { + r = dns_answer_add(answer, j->rr, 0, DNS_ANSWER_AUTHENTICATED); if (r < 0) return r; + + added = true; } - } else { - bool found = false; + } - first = hashmap_get(z->by_key, q->keys[i]); - LIST_FOREACH(by_key, j, first) { - if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) - continue; + if (found && !added) { + r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(key), LLMNR_DEFAULT_TTL); + if (r < 0) + return r; + } + } else { + bool found = false; - found = true; + first = hashmap_get(z->by_key, key); + LIST_FOREACH(by_key, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; - if (j->state != DNS_ZONE_ITEM_PROBING) - tentative = false; + found = true; - r = dns_answer_add(answer, j->rr, 0); - if (r < 0) - return r; - } + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; + + r = dns_answer_add(answer, j->rr, 0, DNS_ANSWER_AUTHENTICATED); + if (r < 0) + return r; + } - if (!found) { - bool add_soa = false; + if (!found) { + bool add_soa = false; - first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])); - LIST_FOREACH(by_name, j, first) { - if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) - continue; + first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(key)); + LIST_FOREACH(by_name, j, first) { + if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) + continue; - if (j->state != DNS_ZONE_ITEM_PROBING) - tentative = false; + if (j->state != DNS_ZONE_ITEM_PROBING) + tentative = false; - add_soa = true; - } + add_soa = true; + } - if (add_soa) { - r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(q->keys[i]), LLMNR_DEFAULT_TTL); - if (r < 0) - return r; - } + if (add_soa) { + r = dns_answer_add_soa(soa, DNS_RESOURCE_KEY_NAME(key), LLMNR_DEFAULT_TTL); + if (r < 0) + return r; } } } + /* If the caller sets ret_tentative to NULL, then use this as + * indication to not return tentative entries */ + + if (!ret_tentative && tentative) + goto return_empty; + *ret_answer = answer; answer = NULL; - *ret_soa = soa; - soa = NULL; + if (ret_soa) { + *ret_soa = soa; + soa = NULL; + } if (ret_tentative) *ret_tentative = tentative; return 1; + +return_empty: + *ret_answer = NULL; + + if (ret_soa) + *ret_soa = NULL; + + if (ret_tentative) + *ret_tentative = false; + + return 0; } void dns_zone_item_conflict(DnsZoneItem *i) { - _cleanup_free_ char *pretty = NULL; - assert(i); if (!IN_SET(i->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_VERIFYING, DNS_ZONE_ITEM_ESTABLISHED)) return; - dns_resource_record_to_string(i->rr, &pretty); - log_info("Detected conflict on %s", strna(pretty)); + log_info("Detected conflict on %s", strna(dns_resource_record_to_string(i->rr))); dns_zone_item_probe_stop(i); @@ -496,16 +488,14 @@ void dns_zone_item_conflict(DnsZoneItem *i) { manager_next_hostname(i->scope->manager); } -void dns_zone_item_ready(DnsZoneItem *i) { - _cleanup_free_ char *pretty = NULL; - +void dns_zone_item_notify(DnsZoneItem *i) { assert(i); assert(i->probe_transaction); if (i->block_ready > 0) return; - if (IN_SET(i->probe_transaction->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)) + if (IN_SET(i->probe_transaction->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) return; if (i->probe_transaction->state == DNS_TRANSACTION_SUCCESS) { @@ -535,15 +525,13 @@ void dns_zone_item_ready(DnsZoneItem *i) { log_debug("Got a successful probe reply, but peer has lexicographically lower IP address and thus lost."); } - dns_resource_record_to_string(i->rr, &pretty); - log_debug("Record %s successfully probed.", strna(pretty)); + log_debug("Record %s successfully probed.", strna(dns_resource_record_to_string(i->rr))); dns_zone_item_probe_stop(i); i->state = DNS_ZONE_ITEM_ESTABLISHED; } static int dns_zone_item_verify(DnsZoneItem *i) { - _cleanup_free_ char *pretty = NULL; int r; assert(i); @@ -551,8 +539,7 @@ static int dns_zone_item_verify(DnsZoneItem *i) { if (i->state != DNS_ZONE_ITEM_ESTABLISHED) return 0; - dns_resource_record_to_string(i->rr, &pretty); - log_debug("Verifying RR %s", strna(pretty)); + log_debug("Verifying RR %s", strna(dns_resource_record_to_string(i->rr))); i->state = DNS_ZONE_ITEM_VERIFYING; r = dns_zone_item_probe_start(i); @@ -637,7 +624,6 @@ void dns_zone_verify_all(DnsZone *zone) { void dns_zone_dump(DnsZone *zone, FILE *f) { Iterator iterator; DnsZoneItem *i; - int r; if (!zone) return; @@ -649,10 +635,10 @@ void dns_zone_dump(DnsZone *zone, FILE *f) { DnsZoneItem *j; LIST_FOREACH(by_key, j, i) { - _cleanup_free_ char *t = NULL; + const char *t; - r = dns_resource_record_to_string(j->rr, &t); - if (r < 0) { + t = dns_resource_record_to_string(j->rr); + if (!t) { log_oom(); continue; } diff --git a/src/resolve/resolved-dns-zone.h b/src/resolve/resolved-dns-zone.h index 495d17cdb1..dbd6a2a368 100644 --- a/src/resolve/resolved-dns-zone.h +++ b/src/resolve/resolved-dns-zone.h @@ -31,9 +31,9 @@ typedef struct DnsZone { typedef struct DnsZoneItem DnsZoneItem; typedef enum DnsZoneItemState DnsZoneItemState; -#include "resolved-dns-rr.h" -#include "resolved-dns-question.h" #include "resolved-dns-answer.h" +#include "resolved-dns-question.h" +#include "resolved-dns-rr.h" #include "resolved-dns-transaction.h" /* RFC 4795 Section 2.8. suggests a TTL of 30s by default */ @@ -67,10 +67,10 @@ void dns_zone_flush(DnsZone *z); int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe); void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr); -int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **answer, DnsAnswer **soa, bool *tentative); +int dns_zone_lookup(DnsZone *z, DnsResourceKey *key, DnsAnswer **answer, DnsAnswer **soa, bool *tentative); void dns_zone_item_conflict(DnsZoneItem *i); -void dns_zone_item_ready(DnsZoneItem *i); +void dns_zone_item_notify(DnsZoneItem *i); int dns_zone_check_conflicts(DnsZone *zone, DnsResourceRecord *rr); int dns_zone_verify_conflicts(DnsZone *zone, DnsResourceKey *key); diff --git a/src/resolve/resolved-gperf.gperf b/src/resolve/resolved-gperf.gperf index 8e78fbf06a..82f26215df 100644 --- a/src/resolve/resolved-gperf.gperf +++ b/src/resolve/resolved-gperf.gperf @@ -14,6 +14,8 @@ struct ConfigPerfItem; %struct-type %includes %% -Resolve.DNS, config_parse_dnsv, DNS_SERVER_SYSTEM, 0 -Resolve.FallbackDNS, config_parse_dnsv, DNS_SERVER_FALLBACK, 0 -Resolve.LLMNR, config_parse_support, 0, offsetof(Manager, llmnr_support) +Resolve.DNS, config_parse_dns_servers, DNS_SERVER_SYSTEM, 0 +Resolve.FallbackDNS, config_parse_dns_servers, DNS_SERVER_FALLBACK, 0 +Resolve.Domains, config_parse_search_domains, 0, 0 +Resolve.LLMNR, config_parse_resolve_support, 0, offsetof(Manager, llmnr_support) +Resolve.DNSSEC, config_parse_dnssec_mode, 0, offsetof(Manager, dnssec_mode) diff --git a/src/resolve/resolved-link-bus.c b/src/resolve/resolved-link-bus.c new file mode 100644 index 0000000000..20352a3e51 --- /dev/null +++ b/src/resolve/resolved-link-bus.c @@ -0,0 +1,528 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "alloc-util.h" +#include "bus-util.h" +#include "parse-util.h" +#include "resolve-util.h" +#include "resolved-bus.h" +#include "resolved-link-bus.h" +#include "strv.h" + +static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_resolve_support, resolve_support, ResolveSupport); +static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_dnssec_mode, dnssec_mode, DnssecMode); + +static int property_get_dns( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + DnsServer *s; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "(iay)"); + if (r < 0) + return r; + + LIST_FOREACH(servers, s, l->dns_servers) { + r = bus_dns_server_append(reply, s, false); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_domains( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + DnsSearchDomain *d; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "s"); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, l->search_domains) { + r = sd_bus_message_append(reply, "s", d->name); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_scopes_mask( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + uint64_t mask; + + assert(reply); + assert(l); + + mask = (l->unicast_scope ? SD_RESOLVED_DNS : 0) | + (l->llmnr_ipv4_scope ? SD_RESOLVED_LLMNR_IPV4 : 0) | + (l->llmnr_ipv6_scope ? SD_RESOLVED_LLMNR_IPV6 : 0) | + (l->mdns_ipv4_scope ? SD_RESOLVED_MDNS_IPV4 : 0) | + (l->mdns_ipv6_scope ? SD_RESOLVED_MDNS_IPV6 : 0); + + return sd_bus_message_append(reply, "t", mask); +} + +static int property_get_ntas( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + const char *name; + Iterator i; + int r; + + assert(reply); + assert(l); + + r = sd_bus_message_open_container(reply, 'a', "s"); + if (r < 0) + return r; + + SET_FOREACH(name, l->dnssec_negative_trust_anchors, i) { + r = sd_bus_message_append(reply, "s", name); + if (r < 0) + return r; + } + + return sd_bus_message_close_container(reply); +} + +static int property_get_dnssec_supported( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + Link *l = userdata; + + assert(reply); + assert(l); + + return sd_bus_message_append(reply, "b", link_dnssec_supported(l)); +} + +int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_free_ struct in_addr_data *dns = NULL; + size_t allocated = 0, n = 0; + Link *l = userdata; + unsigned i; + int r; + + assert(message); + assert(l); + + r = sd_bus_message_enter_container(message, 'a', "(iay)"); + if (r < 0) + return r; + + for (;;) { + int family; + size_t sz; + const void *d; + + assert_cc(sizeof(int) == sizeof(int32_t)); + + r = sd_bus_message_enter_container(message, 'r', "iay"); + if (r < 0) + return r; + if (r == 0) + break; + + r = sd_bus_message_read(message, "i", &family); + if (r < 0) + return r; + + if (!IN_SET(family, AF_INET, AF_INET6)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family); + + r = sd_bus_message_read_array(message, 'y', &d, &sz); + if (r < 0) + return r; + if (sz != FAMILY_ADDRESS_SIZE(family)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size"); + + r = sd_bus_message_exit_container(message); + if (r < 0) + return r; + + if (!GREEDY_REALLOC(dns, allocated, n+1)) + return -ENOMEM; + + dns[n].family = family; + memcpy(&dns[n].address, d, sz); + n++; + } + + r = sd_bus_message_exit_container(message); + if (r < 0) + return r; + + dns_server_mark_all(l->dns_servers); + + for (i = 0; i < n; i++) { + DnsServer *s; + + s = dns_server_find(l->dns_servers, dns[i].family, &dns[i].address); + if (s) + dns_server_move_back_and_unmark(s); + else { + r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, dns[i].family, &dns[i].address); + if (r < 0) + goto clear; + } + + } + + dns_server_unlink_marked(l->dns_servers); + link_allocate_scopes(l); + + return sd_bus_reply_method_return(message, NULL); + +clear: + dns_server_unlink_all(l->dns_servers); + return r; +} + +int bus_link_method_set_search_domains(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_free_ char **domains = NULL; + Link *l = userdata; + char **i; + int r; + + assert(message); + assert(l); + + r = sd_bus_message_read_strv(message, &domains); + if (r < 0) + return r; + + STRV_FOREACH(i, domains) { + + r = dns_name_is_valid(*i); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid search domain %s", *i); + if (dns_name_is_root(*i)) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Root domain is not suitable as search domain"); + } + + dns_search_domain_mark_all(l->search_domains); + + STRV_FOREACH(i, domains) { + DnsSearchDomain *d; + + r = dns_search_domain_find(l->search_domains, *i, &d); + if (r < 0) + goto clear; + + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(l->manager, NULL, DNS_SEARCH_DOMAIN_LINK, l, *i); + if (r < 0) + goto clear; + } + } + + dns_search_domain_unlink_marked(l->search_domains); + return sd_bus_reply_method_return(message, NULL); + +clear: + dns_search_domain_unlink_all(l->search_domains); + return r; +} + +int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + ResolveSupport mode; + const char *llmnr; + int r; + + assert(message); + assert(l); + + r = sd_bus_message_read(message, "s", &llmnr); + if (r < 0) + return r; + + if (isempty(llmnr)) + mode = RESOLVE_SUPPORT_YES; + else { + mode = resolve_support_from_string(llmnr); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid LLMNR setting: %s", llmnr); + } + + l->llmnr_support = mode; + link_allocate_scopes(l); + link_add_rrs(l, false); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + ResolveSupport mode; + const char *mdns; + int r; + + assert(message); + assert(l); + + r = sd_bus_message_read(message, "s", &mdns); + if (r < 0) + return r; + + if (isempty(mdns)) + mode = RESOLVE_SUPPORT_NO; + else { + mode = resolve_support_from_string(mdns); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid MulticastDNS setting: %s", mdns); + } + + l->mdns_support = mode; + link_allocate_scopes(l); + link_add_rrs(l, false); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + const char *dnssec; + DnssecMode mode; + int r; + + assert(message); + assert(l); + + r = sd_bus_message_read(message, "s", &dnssec); + if (r < 0) + return r; + + if (isempty(dnssec)) + mode = _DNSSEC_MODE_INVALID; + else { + mode = dnssec_mode_from_string(dnssec); + if (mode < 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid DNSSEC setting: %s", dnssec); + } + + link_set_dnssec_mode(l, mode); + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error) { + _cleanup_set_free_free_ Set *ns = NULL; + _cleanup_free_ char **ntas = NULL; + Link *l = userdata; + int r; + char **i; + + assert(message); + assert(l); + + r = sd_bus_message_read_strv(message, &ntas); + if (r < 0) + return r; + + STRV_FOREACH(i, ntas) { + r = dns_name_is_valid(*i); + if (r < 0) + return r; + if (r == 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid search negative trust anchor domain: %s", *i); + } + + ns = set_new(&dns_name_hash_ops); + if (!ns) + return -ENOMEM; + + STRV_FOREACH(i, ntas) { + r = set_put_strdup(ns, *i); + if (r < 0) + return r; + } + + set_free_free(l->dnssec_negative_trust_anchors); + l->dnssec_negative_trust_anchors = ns; + ns = NULL; + + return sd_bus_reply_method_return(message, NULL); +} + +int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error *error) { + Link *l = userdata; + + assert(message); + assert(l); + + link_flush_settings(l); + link_allocate_scopes(l); + link_add_rrs(l, false); + + return sd_bus_reply_method_return(message, NULL); +} + +const sd_bus_vtable link_vtable[] = { + SD_BUS_VTABLE_START(0), + + SD_BUS_PROPERTY("ScopesMask", "t", property_get_scopes_mask, 0, 0), + SD_BUS_PROPERTY("DNS", "a(iay)", property_get_dns, 0, 0), + SD_BUS_PROPERTY("Domains", "as", property_get_domains, 0, 0), + SD_BUS_PROPERTY("LLMNR", "s", property_get_resolve_support, offsetof(Link, llmnr_support), 0), + SD_BUS_PROPERTY("MulticastDNS", "s", property_get_resolve_support, offsetof(Link, mdns_support), 0), + SD_BUS_PROPERTY("DNSSEC", "s", property_get_dnssec_mode, offsetof(Link, dnssec_mode), 0), + SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", property_get_ntas, 0, 0), + SD_BUS_PROPERTY("DNSSECSupport", "b", property_get_dnssec_supported, 0, 0), + + SD_BUS_METHOD("SetDNS", "a(iay)", NULL, bus_link_method_set_dns_servers, 0), + SD_BUS_METHOD("SetDomains", "as", NULL, bus_link_method_set_search_domains, 0), + SD_BUS_METHOD("SetLLMNR", "s", NULL, bus_link_method_set_llmnr, 0), + SD_BUS_METHOD("SetMulticastDNS", "s", NULL, bus_link_method_set_mdns, 0), + SD_BUS_METHOD("SetDNSSEC", "s", NULL, bus_link_method_set_dnssec, 0), + SD_BUS_METHOD("SetDNSSECNegativeTrustAnchors", "as", NULL, bus_link_method_set_dnssec_negative_trust_anchors, 0), + SD_BUS_METHOD("Revert", NULL, NULL, bus_link_method_revert, 0), + + SD_BUS_VTABLE_END +}; + +int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) { + _cleanup_free_ char *e = NULL; + Manager *m = userdata; + int ifindex; + Link *link; + int r; + + assert(bus); + assert(path); + assert(interface); + assert(found); + assert(m); + + r = sd_bus_path_decode(path, "/org/freedesktop/resolve1/link", &e); + if (r <= 0) + return 0; + + r = parse_ifindex(e, &ifindex); + if (r < 0) + return 0; + + link = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!link) + return 0; + + *found = link; + return 1; +} + +char *link_bus_path(Link *link) { + _cleanup_free_ char *ifindex = NULL; + char *p; + int r; + + assert(link); + + if (asprintf(&ifindex, "%i", link->ifindex) < 0) + return NULL; + + r = sd_bus_path_encode("/org/freedesktop/resolve1/link", ifindex, &p); + if (r < 0) + return NULL; + + return p; +} + +int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) { + _cleanup_strv_free_ char **l = NULL; + Manager *m = userdata; + Link *link; + Iterator i; + unsigned c = 0; + + assert(bus); + assert(path); + assert(m); + assert(nodes); + + l = new0(char*, hashmap_size(m->links) + 1); + if (!l) + return -ENOMEM; + + HASHMAP_FOREACH(link, m->links, i) { + char *p; + + p = link_bus_path(link); + if (!p) + return -ENOMEM; + + l[c++] = p; + } + + l[c] = NULL; + *nodes = l; + l = NULL; + + return 1; +} diff --git a/src/resolve/resolved-link-bus.h b/src/resolve/resolved-link-bus.h new file mode 100644 index 0000000000..d444957d1c --- /dev/null +++ b/src/resolve/resolved-link-bus.h @@ -0,0 +1,40 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "sd-bus.h" + +#include "resolved-link.h" + +extern const sd_bus_vtable link_vtable[]; + +int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error); +char *link_bus_path(Link *link); +int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error); + +int bus_link_method_set_dns_servers(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_search_domains(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_llmnr(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_mdns(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_dnssec(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_set_dnssec_negative_trust_anchors(sd_bus_message *message, void *userdata, sd_bus_error *error); +int bus_link_method_revert(sd_bus_message *message, void *userdata, sd_bus_error *error); diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index b9fd8e3dbc..b203f19dbb 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -22,9 +22,13 @@ #include <net/if.h> #include "sd-network.h" -#include "strv.h" + +#include "alloc-util.h" #include "missing.h" +#include "parse-util.h" #include "resolved-link.h" +#include "string-util.h" +#include "strv.h" int link_new(Manager *m, Link **ret, int ifindex) { _cleanup_(link_freep) Link *l = NULL; @@ -42,7 +46,9 @@ int link_new(Manager *m, Link **ret, int ifindex) { return -ENOMEM; l->ifindex = ifindex; - l->llmnr_support = SUPPORT_YES; + l->llmnr_support = RESOLVE_SUPPORT_YES; + l->mdns_support = RESOLVE_SUPPORT_NO; + l->dnssec_mode = _DNSSEC_MODE_INVALID; r = hashmap_put(m->links, INT_TO_PTR(ifindex), l); if (r < 0) @@ -57,37 +63,48 @@ int link_new(Manager *m, Link **ret, int ifindex) { return 0; } +void link_flush_settings(Link *l) { + assert(l); + + l->llmnr_support = RESOLVE_SUPPORT_YES; + l->mdns_support = RESOLVE_SUPPORT_NO; + l->dnssec_mode = _DNSSEC_MODE_INVALID; + + dns_server_unlink_all(l->dns_servers); + dns_search_domain_unlink_all(l->search_domains); + + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); +} + Link *link_free(Link *l) { if (!l) return NULL; + link_flush_settings(l); + while (l->addresses) - link_address_free(l->addresses); + (void) link_address_free(l->addresses); if (l->manager) hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex)); - while (l->dns_servers) { - DnsServer *s = l->dns_servers; - - LIST_REMOVE(servers, l->dns_servers, s); - dns_server_unref(s); - } - dns_scope_free(l->unicast_scope); dns_scope_free(l->llmnr_ipv4_scope); dns_scope_free(l->llmnr_ipv6_scope); + dns_scope_free(l->mdns_ipv4_scope); + dns_scope_free(l->mdns_ipv6_scope); free(l); return NULL; } -static void link_allocate_scopes(Link *l) { +void link_allocate_scopes(Link *l) { int r; assert(l); - if (l->dns_servers) { + if (link_relevant(l, AF_UNSPEC, false) && + l->dns_servers) { if (!l->unicast_scope) { r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC); if (r < 0) @@ -96,9 +113,9 @@ static void link_allocate_scopes(Link *l) { } else l->unicast_scope = dns_scope_free(l->unicast_scope); - if (link_relevant(l, AF_INET) && - l->llmnr_support != SUPPORT_NO && - l->manager->llmnr_support != SUPPORT_NO) { + if (link_relevant(l, AF_INET, true) && + l->llmnr_support != RESOLVE_SUPPORT_NO && + l->manager->llmnr_support != RESOLVE_SUPPORT_NO) { if (!l->llmnr_ipv4_scope) { r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET); if (r < 0) @@ -107,9 +124,9 @@ static void link_allocate_scopes(Link *l) { } else l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope); - if (link_relevant(l, AF_INET6) && - l->llmnr_support != SUPPORT_NO && - l->manager->llmnr_support != SUPPORT_NO && + if (link_relevant(l, AF_INET6, true) && + l->llmnr_support != RESOLVE_SUPPORT_NO && + l->manager->llmnr_support != RESOLVE_SUPPORT_NO && socket_ipv6_is_supported()) { if (!l->llmnr_ipv6_scope) { r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6); @@ -118,6 +135,28 @@ static void link_allocate_scopes(Link *l) { } } else l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope); + + if (link_relevant(l, AF_INET, true) && + l->mdns_support != RESOLVE_SUPPORT_NO && + l->manager->mdns_support != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv4_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv4_scope, l, DNS_PROTOCOL_MDNS, AF_INET); + if (r < 0) + log_warning_errno(r, "Failed to allocate mDNS IPv4 scope: %m"); + } + } else + l->mdns_ipv4_scope = dns_scope_free(l->mdns_ipv4_scope); + + if (link_relevant(l, AF_INET6, true) && + l->mdns_support != RESOLVE_SUPPORT_NO && + l->manager->mdns_support != RESOLVE_SUPPORT_NO) { + if (!l->mdns_ipv6_scope) { + r = dns_scope_new(l->manager, &l->mdns_ipv6_scope, l, DNS_PROTOCOL_MDNS, AF_INET6); + if (r < 0) + log_warning_errno(r, "Failed to allocate mDNS IPv6 scope: %m"); + } + } else + l->mdns_ipv6_scope = dns_scope_free(l->mdns_ipv6_scope); } void link_add_rrs(Link *l, bool force_remove) { @@ -154,29 +193,32 @@ int link_update_rtnl(Link *l, sd_netlink_message *m) { static int link_update_dns_servers(Link *l) { _cleanup_strv_free_ char **nameservers = NULL; char **nameserver; - DnsServer *s, *nx; int r; assert(l); r = sd_network_link_get_dns(l->ifindex, &nameservers); + if (r == -ENODATA) { + r = 0; + goto clear; + } if (r < 0) goto clear; - LIST_FOREACH(servers, s, l->dns_servers) - s->marked = true; + dns_server_mark_all(l->dns_servers); STRV_FOREACH(nameserver, nameservers) { union in_addr_union a; + DnsServer *s; int family; r = in_addr_from_string_auto(*nameserver, &family, &a); if (r < 0) goto clear; - s = link_find_dns_server(l, family, &a); + s = dns_server_find(l->dns_servers, family, &a); if (s) - s->marked = false; + dns_server_move_back_and_unmark(s); else { r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a); if (r < 0) @@ -184,104 +226,300 @@ static int link_update_dns_servers(Link *l) { } } - LIST_FOREACH_SAFE(servers, s, nx, l->dns_servers) - if (s->marked) { - LIST_REMOVE(servers, l->dns_servers, s); - dns_server_unref(s); - } - + dns_server_unlink_marked(l->dns_servers); return 0; clear: - while (l->dns_servers) { - s = l->dns_servers; + dns_server_unlink_all(l->dns_servers); + return r; +} + +static int link_update_llmnr_support(Link *l) { + _cleanup_free_ char *b = NULL; + int r; + + assert(l); + + r = sd_network_link_get_llmnr(l->ifindex, &b); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; - LIST_REMOVE(servers, l->dns_servers, s); - dns_server_unref(s); + l->llmnr_support = resolve_support_from_string(b); + if (l->llmnr_support < 0) { + r = -EINVAL; + goto clear; } + return 0; + +clear: + l->llmnr_support = RESOLVE_SUPPORT_YES; return r; } -static int link_update_llmnr_support(Link *l) { +static int link_update_mdns_support(Link *l) { _cleanup_free_ char *b = NULL; int r; assert(l); - r = sd_network_link_get_llmnr(l->ifindex, &b); + r = sd_network_link_get_mdns(l->ifindex, &b); + if (r == -ENODATA) { + r = 0; + goto clear; + } if (r < 0) goto clear; - r = parse_boolean(b); - if (r < 0) { - if (streq(b, "resolve")) - l->llmnr_support = SUPPORT_RESOLVE; - else - goto clear; + l->mdns_support = resolve_support_from_string(b); + if (l->mdns_support < 0) { + r = -EINVAL; + goto clear; + } + + return 0; + +clear: + l->mdns_support = RESOLVE_SUPPORT_NO; + return r; +} + +void link_set_dnssec_mode(Link *l, DnssecMode mode) { + + assert(l); + + if (l->dnssec_mode == mode) + return; + + if ((l->dnssec_mode == _DNSSEC_MODE_INVALID) || + (l->dnssec_mode == DNSSEC_NO && mode != DNSSEC_NO) || + (l->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE && mode == DNSSEC_YES)) { + + /* When switching from non-DNSSEC mode to DNSSEC mode, flush the cache. Also when switching from the + * allow-downgrade mode to full DNSSEC mode, flush it too. */ + if (l->unicast_scope) + dns_cache_flush(&l->unicast_scope->cache); + } + + l->dnssec_mode = mode; +} + +static int link_update_dnssec_mode(Link *l) { + _cleanup_free_ char *m = NULL; + DnssecMode mode; + int r; + + assert(l); + + r = sd_network_link_get_dnssec(l->ifindex, &m); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + mode = dnssec_mode_from_string(m); + if (mode < 0) { + r = -EINVAL; + goto clear; + } + + link_set_dnssec_mode(l, mode); + + return 0; + +clear: + l->dnssec_mode = _DNSSEC_MODE_INVALID; + return r; +} + +static int link_update_dnssec_negative_trust_anchors(Link *l) { + _cleanup_strv_free_ char **ntas = NULL; + _cleanup_set_free_free_ Set *ns = NULL; + char **i; + int r; + + assert(l); - } else if (r > 0) - l->llmnr_support = SUPPORT_YES; - else - l->llmnr_support = SUPPORT_NO; + r = sd_network_link_get_dnssec_negative_trust_anchors(l->ifindex, &ntas); + if (r == -ENODATA) { + r = 0; + goto clear; + } + if (r < 0) + goto clear; + + ns = set_new(&dns_name_hash_ops); + if (!ns) + return -ENOMEM; + + STRV_FOREACH(i, ntas) { + r = set_put_strdup(ns, *i); + if (r < 0) + return r; + } + + set_free_free(l->dnssec_negative_trust_anchors); + l->dnssec_negative_trust_anchors = ns; + ns = NULL; return 0; clear: - l->llmnr_support = SUPPORT_YES; + l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors); return r; } -static int link_update_domains(Link *l) { +static int link_update_search_domains(Link *l) { + _cleanup_strv_free_ char **domains = NULL; + char **i; int r; - if (!l->unicast_scope) - return 0; + assert(l); - l->unicast_scope->domains = strv_free(l->unicast_scope->domains); + r = sd_network_link_get_domains(l->ifindex, &domains); + if (r == -ENODATA) { + /* networkd knows nothing about this interface, and that's fine. */ + r = 0; + goto clear; + } + if (r < 0) + goto clear; - r = sd_network_link_get_domains(l->ifindex, - &l->unicast_scope->domains); + dns_search_domain_mark_all(l->search_domains); + + STRV_FOREACH(i, domains) { + DnsSearchDomain *d; + + r = dns_search_domain_find(l->search_domains, *i, &d); + if (r < 0) + goto clear; + + if (r > 0) + dns_search_domain_move_back_and_unmark(d); + else { + r = dns_search_domain_new(l->manager, NULL, DNS_SEARCH_DOMAIN_LINK, l, *i); + if (r < 0) + goto clear; + } + } + + dns_search_domain_unlink_marked(l->search_domains); + return 0; + +clear: + dns_search_domain_unlink_all(l->search_domains); + return r; +} + +static int link_is_unmanaged(Link *l) { + _cleanup_free_ char *state = NULL; + int r; + + assert(l); + + r = sd_network_link_get_setup_state(l->ifindex, &state); + if (r == -ENODATA) + return 1; if (r < 0) return r; - return 0; + return STR_IN_SET(state, "pending", "unmanaged"); +} + +static void link_read_settings(Link *l) { + int r; + + assert(l); + + /* Read settings from networkd, except when networkd is not managing this interface. */ + + r = link_is_unmanaged(l); + if (r < 0) { + log_warning_errno(r, "Failed to determine whether interface %s is managed: %m", l->name); + return; + } + if (r > 0) { + + /* If this link used to be managed, but is now unmanaged, flush all our settings -- but only once. */ + if (l->is_managed) + link_flush_settings(l); + + l->is_managed = false; + return; + } + + l->is_managed = true; + + r = link_update_dns_servers(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNS servers for interface %s, ignoring: %m", l->name); + + r = link_update_llmnr_support(l); + if (r < 0) + log_warning_errno(r, "Failed to read LLMNR support for interface %s, ignoring: %m", l->name); + + r = link_update_mdns_support(l); + if (r < 0) + log_warning_errno(r, "Failed to read mDNS support for interface %s, ignoring: %m", l->name); + + r = link_update_dnssec_mode(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNSSEC mode for interface %s, ignoring: %m", l->name); + + r = link_update_dnssec_negative_trust_anchors(l); + if (r < 0) + log_warning_errno(r, "Failed to read DNSSEC negative trust anchors for interface %s, ignoring: %m", l->name); + + r = link_update_search_domains(l); + if (r < 0) + log_warning_errno(r, "Failed to read search domains for interface %s, ignoring: %m", l->name); } int link_update_monitor(Link *l) { assert(l); - link_update_dns_servers(l); - link_update_llmnr_support(l); + link_read_settings(l); link_allocate_scopes(l); - link_update_domains(l); link_add_rrs(l, false); return 0; } -bool link_relevant(Link *l, int family) { +bool link_relevant(Link *l, int family, bool multicast) { _cleanup_free_ char *state = NULL; LinkAddress *a; assert(l); - /* A link is relevant if it isn't a loopback or pointopoint - * device, has a link beat, can do multicast and has at least - * one relevant IP address */ + /* A link is relevant for multicast traffic if it isn't a loopback or pointopoint device, has a link beat, can + * do multicast and has at least one relevant IP address */ - if (l->flags & (IFF_LOOPBACK|IFF_POINTOPOINT|IFF_DORMANT)) + if (l->flags & (IFF_LOOPBACK|IFF_DORMANT)) return false; - if ((l->flags & (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) != (IFF_UP|IFF_LOWER_UP|IFF_MULTICAST)) + if ((l->flags & (IFF_UP|IFF_LOWER_UP)) != (IFF_UP|IFF_LOWER_UP)) return false; + if (multicast) { + if (l->flags & IFF_POINTOPOINT) + return false; + + if ((l->flags & IFF_MULTICAST) != IFF_MULTICAST) + return false; + } + sd_network_link_get_operational_state(l->ifindex, &state); if (state && !STR_IN_SET(state, "unknown", "degraded", "routable")) return false; LIST_FOREACH(addresses, a, l->addresses) - if (a->family == family && link_address_relevant(a)) + if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a)) return true; return false; @@ -299,31 +537,17 @@ LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *i return NULL; } -DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr) { - DnsServer *s; - - assert(l); - - LIST_FOREACH(servers, s, l->dns_servers) - if (s->family == family && in_addr_equal(family, &s->address, in_addr)) - return s; - return NULL; -} - DnsServer* link_set_dns_server(Link *l, DnsServer *s) { assert(l); if (l->current_dns_server == s) return s; - if (s) { - _cleanup_free_ char *ip = NULL; + if (s) + log_info("Switching to DNS server %s for interface %s.", dns_server_string(s), l->name); - in_addr_to_string(s->family, &s->address, &ip); - log_info("Switching to DNS server %s for interface %s.", strna(ip), l->name); - } - - l->current_dns_server = s; + dns_server_unref(l->current_dns_server); + l->current_dns_server = dns_server_ref(s); if (l->unicast_scope) dns_cache_flush(&l->unicast_scope->cache); @@ -346,7 +570,9 @@ void link_next_dns_server(Link *l) { if (!l->current_dns_server) return; - if (l->current_dns_server->servers_next) { + /* Change to the next one, but make sure to follow the linked + * list only if this server is actually still linked. */ + if (l->current_dns_server->linked && l->current_dns_server->servers_next) { link_set_dns_server(l, l->current_dns_server->servers_next); return; } @@ -354,6 +580,30 @@ void link_next_dns_server(Link *l) { link_set_dns_server(l, l->dns_servers); } +DnssecMode link_get_dnssec_mode(Link *l) { + assert(l); + + if (l->dnssec_mode != _DNSSEC_MODE_INVALID) + return l->dnssec_mode; + + return manager_get_dnssec_mode(l->manager); +} + +bool link_dnssec_supported(Link *l) { + DnsServer *server; + + assert(l); + + if (link_get_dnssec_mode(l) == DNSSEC_NO) + return false; + + server = link_get_dns_server(l); + if (server) + return dns_server_dnssec_supported(server); + + return true; +} + int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) { LinkAddress *a; @@ -415,8 +665,8 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) { if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv4_scope && - a->link->llmnr_support == SUPPORT_YES && - a->link->manager->llmnr_support == SUPPORT_YES) { + a->link->llmnr_support == RESOLVE_SUPPORT_YES && + a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { if (!a->link->manager->llmnr_host_ipv4_key) { a->link->manager->llmnr_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->llmnr_hostname); @@ -472,8 +722,8 @@ void link_address_add_rrs(LinkAddress *a, bool force_remove) { if (!force_remove && link_address_relevant(a) && a->link->llmnr_ipv6_scope && - a->link->llmnr_support == SUPPORT_YES && - a->link->manager->llmnr_support == SUPPORT_YES) { + a->link->llmnr_support == RESOLVE_SUPPORT_YES && + a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) { if (!a->link->manager->llmnr_host_ipv6_key) { a->link->manager->llmnr_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->llmnr_hostname); diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h index e3ab27c249..6544214b77 100644 --- a/src/resolve/resolved-link.h +++ b/src/resolve/resolved-link.h @@ -25,13 +25,19 @@ #include "in-addr-util.h" #include "ratelimit.h" +#include "resolve-util.h" typedef struct Link Link; typedef struct LinkAddress LinkAddress; #include "resolved-dns-rr.h" +#include "resolved-dns-search-domain.h" +#include "resolved-dns-server.h" #include "resolved-manager.h" +#define LINK_SEARCH_DOMAINS_MAX 32 +#define LINK_DNS_SERVERS_MAX 32 + struct LinkAddress { Link *link; @@ -56,12 +62,23 @@ struct Link { LIST_HEAD(DnsServer, dns_servers); DnsServer *current_dns_server; + unsigned n_dns_servers; + + LIST_HEAD(DnsSearchDomain, search_domains); + unsigned n_search_domains; - Support llmnr_support; + ResolveSupport llmnr_support; + ResolveSupport mdns_support; + DnssecMode dnssec_mode; + Set *dnssec_negative_trust_anchors; DnsScope *unicast_scope; DnsScope *llmnr_ipv4_scope; DnsScope *llmnr_ipv6_scope; + DnsScope *mdns_ipv4_scope; + DnsScope *mdns_ipv6_scope; + + bool is_managed; char name[IF_NAMESIZE]; uint32_t mtu; @@ -71,15 +88,21 @@ int link_new(Manager *m, Link **ret, int ifindex); Link *link_free(Link *l); int link_update_rtnl(Link *l, sd_netlink_message *m); int link_update_monitor(Link *l); -bool link_relevant(Link *l, int family); +bool link_relevant(Link *l, int family, bool multicast); LinkAddress* link_find_address(Link *l, int family, const union in_addr_union *in_addr); void link_add_rrs(Link *l, bool force_remove); +void link_flush_settings(Link *l); +void link_set_dnssec_mode(Link *l, DnssecMode mode); +void link_allocate_scopes(Link *l); + DnsServer* link_set_dns_server(Link *l, DnsServer *s); -DnsServer* link_find_dns_server(Link *l, int family, const union in_addr_union *in_addr); DnsServer* link_get_dns_server(Link *l); void link_next_dns_server(Link *l); +DnssecMode link_get_dnssec_mode(Link *l); +bool link_dnssec_supported(Link *l); + int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr); LinkAddress *link_address_free(LinkAddress *a); int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m); diff --git a/src/resolve/resolved-llmnr.c b/src/resolve/resolved-llmnr.c index 8afaf8db6e..f52ab8f384 100644 --- a/src/resolve/resolved-llmnr.c +++ b/src/resolve/resolved-llmnr.c @@ -19,11 +19,12 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include <resolv.h> #include <netinet/in.h> +#include <resolv.h> -#include "resolved-manager.h" +#include "fd-util.h" #include "resolved-llmnr.h" +#include "resolved-manager.h" void manager_llmnr_stop(Manager *m) { assert(m); @@ -46,7 +47,7 @@ int manager_llmnr_start(Manager *m) { assert(m); - if (m->llmnr_support == SUPPORT_NO) + if (m->llmnr_support == RESOLVE_SUPPORT_NO) return 0; r = manager_llmnr_ipv4_udp_fd(m); @@ -79,7 +80,7 @@ int manager_llmnr_start(Manager *m) { eaddrinuse: log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); - m->llmnr_support = SUPPORT_NO; + m->llmnr_support = RESOLVE_SUPPORT_NO; manager_llmnr_stop(m); return 0; @@ -116,7 +117,7 @@ static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *u dns_scope_process_query(scope, NULL, p); } else - log_debug("Invalid LLMNR UDP packet."); + log_debug("Invalid LLMNR UDP packet, ignoring."); return 0; } @@ -192,6 +193,8 @@ int manager_llmnr_ipv4_udp_fd(Manager *m) { if (r < 0) goto fail; + (void) sd_event_source_set_description(m->llmnr_ipv4_udp_event_source, "llmnr-ipv4-udp"); + return m->llmnr_ipv4_udp_fd; fail: @@ -266,10 +269,10 @@ int manager_llmnr_ipv6_udp_fd(Manager *m) { } r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, m->llmnr_ipv6_udp_fd, EPOLLIN, on_llmnr_packet, m); - if (r < 0) { - r = -errno; + if (r < 0) goto fail; - } + + (void) sd_event_source_set_description(m->llmnr_ipv6_udp_event_source, "llmnr-ipv6-udp"); return m->llmnr_ipv6_udp_fd; @@ -392,6 +395,8 @@ int manager_llmnr_ipv4_tcp_fd(Manager *m) { if (r < 0) goto fail; + (void) sd_event_source_set_description(m->llmnr_ipv4_tcp_event_source, "llmnr-ipv4-tcp"); + return m->llmnr_ipv4_tcp_fd; fail: @@ -460,10 +465,10 @@ int manager_llmnr_ipv6_tcp_fd(Manager *m) { } r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m); - if (r < 0) { - r = -errno; + if (r < 0) goto fail; - } + + (void) sd_event_source_set_description(m->llmnr_ipv6_tcp_event_source, "llmnr-ipv6-tcp"); return m->llmnr_ipv6_tcp_fd; diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index de924e3ed9..d6d75a3f78 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -19,26 +19,32 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include <resolv.h> -#include <sys/ioctl.h> -#include <poll.h> #include <netinet/in.h> +#include <poll.h> +#include <sys/ioctl.h> -#include "netlink-util.h" -#include "network-internal.h" -#include "socket-util.h" #include "af-list.h" -#include "utf8.h" +#include "alloc-util.h" +#include "dns-domain.h" +#include "fd-util.h" #include "fileio-label.h" +#include "hostname-util.h" +#include "io-util.h" +#include "netlink-util.h" +#include "network-internal.h" #include "ordered-set.h" +#include "parse-util.h" #include "random-util.h" -#include "hostname-util.h" - -#include "dns-domain.h" -#include "resolved-conf.h" #include "resolved-bus.h" -#include "resolved-manager.h" +#include "resolved-conf.h" #include "resolved-llmnr.h" +#include "resolved-manager.h" +#include "resolved-resolv-conf.h" +#include "resolved-mdns.h" +#include "socket-util.h" +#include "string-table.h" +#include "string-util.h" +#include "utf8.h" #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC) @@ -188,7 +194,7 @@ fail: } static int manager_rtnl_listen(Manager *m) { - _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL; + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL; sd_netlink_message *i; int r; @@ -307,6 +313,8 @@ static int manager_network_monitor_listen(Manager *m) { if (r < 0) return r; + (void) sd_event_source_set_description(m->network_event_source, "network-monitor"); + return 0; } @@ -346,7 +354,7 @@ static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) { return -EINVAL; } - r = dns_label_escape(label, r, &n); + r = dns_label_escape_new(label, r, &n); if (r < 0) return log_error_errno(r, "Failed to escape host name: %m"); @@ -414,6 +422,8 @@ static int manager_watch_hostname(Manager *m) { return log_error_errno(r, "Failed to add hostname event source: %m"); } + (void) sd_event_source_set_description(m->hostname_event_source, "hostname"); + r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname); if (r < 0) { log_info("Defaulting to hostname 'linux'."); @@ -467,12 +477,20 @@ int manager_new(Manager **ret) { m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; + m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1; m->hostname_fd = -1; - m->llmnr_support = SUPPORT_YES; + m->llmnr_support = RESOLVE_SUPPORT_YES; + m->mdns_support = RESOLVE_SUPPORT_NO; + m->dnssec_mode = DNSSEC_NO; m->read_resolv_conf = true; + m->need_builtin_fallbacks = true; + + r = dns_trust_anchor_load(&m->trust_anchor); + if (r < 0) + return r; - r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS); + r = manager_parse_config_file(m); if (r < 0) return r; @@ -522,6 +540,10 @@ int manager_start(Manager *m) { if (r < 0) return r; + r = manager_mdns_start(m); + if (r < 0) + return r; + return 0; } @@ -531,15 +553,16 @@ Manager *manager_free(Manager *m) { if (!m) return NULL; + dns_server_unlink_all(m->dns_servers); + dns_server_unlink_all(m->fallback_dns_servers); + dns_search_domain_unlink_all(m->search_domains); + while ((l = hashmap_first(m->links))) link_free(l); while (m->dns_queries) dns_query_free(m->dns_queries); - manager_flush_dns_servers(m, DNS_SERVER_SYSTEM); - manager_flush_dns_servers(m, DNS_SERVER_FALLBACK); - dns_scope_free(m->unicast_scope); hashmap_free(m->links); @@ -548,7 +571,11 @@ Manager *manager_free(Manager *m) { sd_event_source_unref(m->network_event_source); sd_network_monitor_unref(m->network_monitor); + sd_netlink_unref(m->rtnl); + sd_event_source_unref(m->rtnl_event_source); + manager_llmnr_stop(m); + manager_mdns_stop(m); sd_bus_slot_unref(m->prepare_for_sleep_slot); sd_event_source_unref(m->bus_retry_event_source); @@ -566,299 +593,13 @@ Manager *manager_free(Manager *m) { free(m->llmnr_hostname); free(m->mdns_hostname); + dns_trust_anchor_flush(&m->trust_anchor); + free(m); return NULL; } -int manager_read_resolv_conf(Manager *m) { - _cleanup_fclose_ FILE *f = NULL; - struct stat st, own; - char line[LINE_MAX]; - DnsServer *s, *nx; - usec_t t; - int r; - - assert(m); - - /* Reads the system /etc/resolv.conf, if it exists and is not - * symlinked to our own resolv.conf instance */ - - if (!m->read_resolv_conf) - return 0; - - r = stat("/etc/resolv.conf", &st); - if (r < 0) { - if (errno != ENOENT) - log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); - r = -errno; - goto clear; - } - - /* Have we already seen the file? */ - t = timespec_load(&st.st_mtim); - if (t == m->resolv_conf_mtime) - return 0; - - m->resolv_conf_mtime = t; - - /* Is it symlinked to our own file? */ - if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && - st.st_dev == own.st_dev && - st.st_ino == own.st_ino) { - r = 0; - goto clear; - } - - f = fopen("/etc/resolv.conf", "re"); - if (!f) { - if (errno != ENOENT) - log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); - r = -errno; - goto clear; - } - - if (fstat(fileno(f), &st) < 0) { - r = log_error_errno(errno, "Failed to stat open file: %m"); - goto clear; - } - - LIST_FOREACH(servers, s, m->dns_servers) - s->marked = true; - - FOREACH_LINE(line, f, r = -errno; goto clear) { - union in_addr_union address; - int family; - char *l; - const char *a; - - truncate_nl(line); - - l = strstrip(line); - if (*l == '#' || *l == ';') - continue; - - a = first_word(l, "nameserver"); - if (!a) - continue; - - r = in_addr_from_string_auto(a, &family, &address); - if (r < 0) { - log_warning("Failed to parse name server %s.", a); - continue; - } - - LIST_FOREACH(servers, s, m->dns_servers) - if (s->family == family && in_addr_equal(family, &s->address, &address) > 0) - break; - - if (s) - s->marked = false; - else { - r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address); - if (r < 0) - goto clear; - } - } - - LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers) - if (s->marked) { - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } - - /* Whenever /etc/resolv.conf changes, start using the first - * DNS server of it. This is useful to deal with broken - * network managing implementations (like NetworkManager), - * that when connecting to a VPN place both the VPN DNS - * servers and the local ones in /etc/resolv.conf. Without - * resetting the DNS server to use back to the first entry we - * will continue to use the local one thus being unable to - * resolve VPN domains. */ - manager_set_dns_server(m, m->dns_servers); - - return 0; - -clear: - while (m->dns_servers) { - s = m->dns_servers; - - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } - - return r; -} - -static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { - _cleanup_free_ char *t = NULL; - int r; - - assert(s); - assert(f); - assert(count); - - r = in_addr_to_string(s->family, &s->address, &t); - if (r < 0) { - log_warning_errno(r, "Invalid DNS address. Ignoring: %m"); - return; - } - - if (*count == MAXNS) - fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); - - fprintf(f, "nameserver %s\n", t); - (*count) ++; -} - -static void write_resolv_conf_search( - const char *domain, FILE *f, - unsigned *count, - unsigned *length) { - - assert(domain); - assert(f); - assert(length); - - if (*count >= MAXDNSRCH || - *length + strlen(domain) > 256) { - if (*count == MAXDNSRCH) - fputs(" # Too many search domains configured, remaining ones ignored.", f); - if (*length <= 256) - fputs(" # Total length of all search domains is too long, remaining ones ignored.", f); - - return; - } - - fprintf(f, " %s", domain); - - (*length) += strlen(domain); - (*count) ++; -} - -static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { - Iterator i; - - fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" - "# Third party programs must not access this file directly, but\n" - "# only through the symlink at /etc/resolv.conf. To manage\n" - "# resolv.conf(5) in a different way, replace the symlink by a\n" - "# static file or a different symlink.\n\n", f); - - if (ordered_set_isempty(dns)) - fputs("# No DNS servers known.\n", f); - else { - DnsServer *s; - unsigned count = 0; - - ORDERED_SET_FOREACH(s, dns, i) - write_resolv_conf_server(s, f, &count); - } - - if (!ordered_set_isempty(domains)) { - unsigned length = 0, count = 0; - char *domain; - - fputs("search", f); - ORDERED_SET_FOREACH(domain, domains, i) - write_resolv_conf_search(domain, f, &count, &length); - fputs("\n", f); - } - - return fflush_and_check(f); -} - -int manager_write_resolv_conf(Manager *m) { - static const char path[] = "/run/systemd/resolve/resolv.conf"; - _cleanup_free_ char *temp_path = NULL; - _cleanup_fclose_ FILE *f = NULL; - _cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL; - DnsServer *s; - Iterator i; - Link *l; - int r; - - assert(m); - - /* Read the system /etc/resolv.conf first */ - manager_read_resolv_conf(m); - - /* Add the full list to a set, to filter out duplicates */ - dns = ordered_set_new(&dns_server_hash_ops); - if (!dns) - return -ENOMEM; - - domains = ordered_set_new(&dns_name_hash_ops); - if (!domains) - return -ENOMEM; - - /* First add the system-wide servers */ - LIST_FOREACH(servers, s, m->dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - - /* Then, add the per-link servers and domains */ - HASHMAP_FOREACH(l, m->links, i) { - char **domain; - - LIST_FOREACH(servers, s, l->dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - - if (!l->unicast_scope) - continue; - - STRV_FOREACH(domain, l->unicast_scope->domains) { - r = ordered_set_put(domains, *domain); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - } - - /* If we found nothing, add the fallback servers */ - if (ordered_set_isempty(dns)) { - LIST_FOREACH(servers, s, m->fallback_dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - } - - r = fopen_temporary_label(path, path, &f, &temp_path); - if (r < 0) - return r; - - fchmod(fileno(f), 0644); - - r = write_resolv_conf_contents(f, dns, domains); - if (r < 0) - goto fail; - - if (rename(temp_path, path) < 0) { - r = -errno; - goto fail; - } - - return 0; - -fail: - (void) unlink(path); - (void) unlink(temp_path); - return r; -} - int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; union { @@ -1041,7 +782,7 @@ static int write_loop(int fd, void *message, size_t length) { int manager_write(Manager *m, int fd, DnsPacket *p) { int r; - log_debug("Sending %s packet with id %u", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p)); + log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p)); r = write_loop(fd, DNS_PACKET_DATA(p), p->size); if (r < 0) @@ -1156,7 +897,7 @@ int manager_send(Manager *m, int fd, int ifindex, int family, const union in_add assert(port > 0); assert(p); - log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family)); + log_debug("Sending %s packet with id %" PRIu16 " on interface %i/%s.", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family)); if (family == AF_INET) return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p); @@ -1166,97 +907,6 @@ int manager_send(Manager *m, int fd, int ifindex, int family, const union in_add return -EAFNOSUPPORT; } -DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) { - DnsServer *s; - - assert(m); - assert(in_addr); - - LIST_FOREACH(servers, s, m->dns_servers) - if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0) - return s; - - LIST_FOREACH(servers, s, m->fallback_dns_servers) - if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0) - return s; - - return NULL; -} - -DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) { - assert(m); - - if (m->current_dns_server == s) - return s; - - if (s) { - _cleanup_free_ char *ip = NULL; - - in_addr_to_string(s->family, &s->address, &ip); - log_info("Switching to system DNS server %s.", strna(ip)); - } - - m->current_dns_server = s; - - if (m->unicast_scope) - dns_cache_flush(&m->unicast_scope->cache); - - return s; -} - -DnsServer *manager_get_dns_server(Manager *m) { - Link *l; - assert(m); - - /* Try to read updates resolv.conf */ - manager_read_resolv_conf(m); - - if (!m->current_dns_server) - manager_set_dns_server(m, m->dns_servers); - - if (!m->current_dns_server) { - bool found = false; - Iterator i; - - /* No DNS servers configured, let's see if there are - * any on any links. If not, we use the fallback - * servers */ - - HASHMAP_FOREACH(l, m->links, i) - if (l->dns_servers) { - found = true; - break; - } - - if (!found) - manager_set_dns_server(m, m->fallback_dns_servers); - } - - return m->current_dns_server; -} - -void manager_next_dns_server(Manager *m) { - assert(m); - - /* If there's currently no DNS server set, then the next - * manager_get_dns_server() will find one */ - if (!m->current_dns_server) - return; - - /* Change to the next one */ - if (m->current_dns_server->servers_next) { - manager_set_dns_server(m, m->current_dns_server->servers_next); - return; - } - - /* If there was no next one, then start from the beginning of - * the list */ - if (m->current_dns_server->type == DNS_SERVER_FALLBACK) - manager_set_dns_server(m, m->fallback_dns_servers); - else - manager_set_dns_server(m, m->dns_servers); -} - uint32_t manager_find_mtu(Manager *m) { uint32_t mtu = 0; Link *l; @@ -1391,11 +1041,25 @@ DnsScope* manager_find_scope(Manager *m, DnsPacket *p) { if (!l) return NULL; - if (p->protocol == DNS_PROTOCOL_LLMNR) { + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: if (p->family == AF_INET) return l->llmnr_ipv4_scope; else if (p->family == AF_INET6) return l->llmnr_ipv6_scope; + + break; + + case DNS_PROTOCOL_MDNS: + if (p->family == AF_INET) + return l->mdns_ipv4_scope; + else if (p->family == AF_INET6) + return l->mdns_ipv6_scope; + + break; + + default: + break; } return NULL; @@ -1410,49 +1074,132 @@ void manager_verify_all(Manager *m) { dns_zone_verify_all(&s->zone); } -void manager_flush_dns_servers(Manager *m, DnsServerType t) { +int manager_is_own_hostname(Manager *m, const char *name) { + int r; + + assert(m); + assert(name); + + if (m->llmnr_hostname) { + r = dns_name_equal(name, m->llmnr_hostname); + if (r != 0) + return r; + } + + if (m->mdns_hostname) + return dns_name_equal(name, m->mdns_hostname); + + return 0; +} + +int manager_compile_dns_servers(Manager *m, OrderedSet **dns) { DnsServer *s; + Iterator i; + Link *l; + int r; assert(m); + assert(dns); - if (t == DNS_SERVER_SYSTEM) - while (m->dns_servers) { - s = m->dns_servers; + r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops); + if (r < 0) + return r; - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } + /* First add the system-wide servers and domains */ + LIST_FOREACH(servers, s, m->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } - if (t == DNS_SERVER_FALLBACK) - while (m->fallback_dns_servers) { - s = m->fallback_dns_servers; + /* Then, add the per-link servers */ + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(servers, s, l->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } - LIST_REMOVE(servers, m->fallback_dns_servers, s); - dns_server_unref(s); + /* If we found nothing, add the fallback servers */ + if (ordered_set_isempty(*dns)) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; } + } + + return 0; } -int manager_is_own_hostname(Manager *m, const char *name) { +int manager_compile_search_domains(Manager *m, OrderedSet **domains) { + DnsSearchDomain *d; + Iterator i; + Link *l; int r; assert(m); - assert(name); + assert(domains); - if (m->llmnr_hostname) { - r = dns_name_equal(name, m->llmnr_hostname); - if (r != 0) + r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, m->search_domains) { + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) return r; } - if (m->mdns_hostname) - return dns_name_equal(name, m->mdns_hostname); + HASHMAP_FOREACH(l, m->links, i) { + + LIST_FOREACH(domains, d, l->search_domains) { + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } return 0; } -static const char* const support_table[_SUPPORT_MAX] = { - [SUPPORT_NO] = "no", - [SUPPORT_YES] = "yes", - [SUPPORT_RESOLVE] = "resolve", -}; -DEFINE_STRING_TABLE_LOOKUP(support, Support); +DnssecMode manager_get_dnssec_mode(Manager *m) { + assert(m); + + if (m->dnssec_mode != _DNSSEC_MODE_INVALID) + return m->dnssec_mode; + + return DNSSEC_NO; +} + +bool manager_dnssec_supported(Manager *m) { + DnsServer *server; + Iterator i; + Link *l; + + assert(m); + + if (manager_get_dnssec_mode(m) == DNSSEC_NO) + return false; + + server = manager_get_dns_server(m); + if (server && !dns_server_dnssec_supported(server)) + return false; + + HASHMAP_FOREACH(l, m->links, i) + if (!link_dnssec_supported(l)) + return false; + + return true; +} diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index fe7fe99505..8b13074298 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -22,30 +22,32 @@ ***/ #include "sd-event.h" -#include "sd-network.h" #include "sd-netlink.h" -#include "list.h" +#include "sd-network.h" + #include "hashmap.h" +#include "list.h" +#include "ordered-set.h" +#include "resolve-util.h" typedef struct Manager Manager; -typedef enum Support Support; - -enum Support { - SUPPORT_NO, - SUPPORT_YES, - SUPPORT_RESOLVE, - _SUPPORT_MAX, - _SUPPORT_INVALID = -1 -}; #include "resolved-dns-query.h" +#include "resolved-dns-search-domain.h" +#include "resolved-dns-server.h" #include "resolved-dns-stream.h" +#include "resolved-dns-trust-anchor.h" #include "resolved-link.h" +#define MANAGER_SEARCH_DOMAINS_MAX 32 +#define MANAGER_DNS_SERVERS_MAX 32 + struct Manager { sd_event *event; - Support llmnr_support; + ResolveSupport llmnr_support; + ResolveSupport mdns_support; + DnssecMode dnssec_mode; /* Network */ Hashmap *links; @@ -67,11 +69,19 @@ struct Manager { /* Unicast dns */ LIST_HEAD(DnsServer, dns_servers); LIST_HEAD(DnsServer, fallback_dns_servers); + unsigned n_dns_servers; /* counts both main and fallback */ DnsServer *current_dns_server; - bool read_resolv_conf; + LIST_HEAD(DnsSearchDomain, search_domains); + unsigned n_search_domains; + + bool need_builtin_fallbacks:1; + + bool read_resolv_conf:1; usec_t resolv_conf_mtime; + DnsTrustAnchor trust_anchor; + LIST_HEAD(DnsScope, dns_scopes); DnsScope *unicast_scope; @@ -86,6 +96,13 @@ struct Manager { sd_event_source *llmnr_ipv4_tcp_event_source; sd_event_source *llmnr_ipv6_tcp_event_source; + /* mDNS */ + int mdns_ipv4_fd; + int mdns_ipv6_fd; + + sd_event_source *mdns_ipv4_event_source; + sd_event_source *mdns_ipv6_event_source; + /* dbus */ sd_bus *bus; sd_event_source *bus_retry_event_source; @@ -104,6 +121,9 @@ struct Manager { sd_bus_slot *prepare_for_sleep_slot; sd_event_source *sigusr1_event_source; + + unsigned n_transactions_total; + unsigned n_dnssec_secure, n_dnssec_insecure, n_dnssec_bogus, n_dnssec_indeterminate; }; /* Manager */ @@ -112,13 +132,6 @@ int manager_new(Manager **ret); Manager* manager_free(Manager *m); int manager_start(Manager *m); -int manager_read_resolv_conf(Manager *m); -int manager_write_resolv_conf(Manager *m); - -DnsServer *manager_set_dns_server(Manager *m, DnsServer *s); -DnsServer *manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr); -DnsServer *manager_get_dns_server(Manager *m); -void manager_next_dns_server(Manager *m); uint32_t manager_find_mtu(Manager *m); @@ -137,13 +150,14 @@ DnsScope* manager_find_scope(Manager *m, DnsPacket *p); void manager_verify_all(Manager *m); -void manager_flush_dns_servers(Manager *m, DnsServerType t); - DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); #define EXTRA_CMSG_SPACE 1024 int manager_is_own_hostname(Manager *m, const char *name); -const char* support_to_string(Support p) _const_; -int support_from_string(const char *s) _pure_; +int manager_compile_dns_servers(Manager *m, OrderedSet **servers); +int manager_compile_search_domains(Manager *m, OrderedSet **domains); + +DnssecMode manager_get_dnssec_mode(Manager *m); +bool manager_dnssec_supported(Manager *m); diff --git a/src/resolve/resolved-mdns.c b/src/resolve/resolved-mdns.c new file mode 100644 index 0000000000..d5b253d4f5 --- /dev/null +++ b/src/resolve/resolved-mdns.c @@ -0,0 +1,289 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Daniel Mack + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <resolv.h> +#include <netinet/in.h> +#include <arpa/inet.h> + +#include "fd-util.h" +#include "resolved-manager.h" +#include "resolved-mdns.h" + +void manager_mdns_stop(Manager *m) { + assert(m); + + m->mdns_ipv4_event_source = sd_event_source_unref(m->mdns_ipv4_event_source); + m->mdns_ipv4_fd = safe_close(m->mdns_ipv4_fd); + + m->mdns_ipv6_event_source = sd_event_source_unref(m->mdns_ipv6_event_source); + m->mdns_ipv6_fd = safe_close(m->mdns_ipv6_fd); +} + +int manager_mdns_start(Manager *m) { + int r; + + assert(m); + + if (m->mdns_support == RESOLVE_SUPPORT_NO) + return 0; + + r = manager_mdns_ipv4_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + if (socket_ipv6_is_supported()) { + r = manager_mdns_ipv6_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + } + + return 0; + +eaddrinuse: + log_warning("There appears to be another mDNS responder running. Turning off mDNS support."); + m->mdns_support = RESOLVE_SUPPORT_NO; + manager_mdns_stop(m); + + return 0; +} + +static int on_mdns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + Manager *m = userdata; + DnsScope *scope; + int r; + + r = manager_recv(m, fd, DNS_PROTOCOL_MDNS, &p); + if (r <= 0) + return r; + + scope = manager_find_scope(m, p); + if (!scope) { + log_warning("Got mDNS UDP packet on unknown scope. Ignoring."); + return 0; + } + + if (dns_packet_validate_reply(p) > 0) { + DnsResourceRecord *rr; + + log_debug("Got mDNS reply packet"); + + /* + * mDNS is different from regular DNS and LLMNR with regard to handling responses. + * While on other protocols, we can ignore every answer that doesn't match a question + * we broadcast earlier, RFC6762, section 18.1 recommends looking at and caching all + * incoming information, regardless of the DNS packet ID. + * + * Hence, extract the packet here, and try to find a transaction for answer the we got + * and complete it. Also store the new information in scope's cache. + */ + r = dns_packet_extract(p); + if (r < 0) { + log_debug("mDNS packet extraction failed."); + return 0; + } + + dns_scope_check_conflicts(scope, p); + + DNS_ANSWER_FOREACH(rr, p->answer) { + const char *name = DNS_RESOURCE_KEY_NAME(rr->key); + DnsTransaction *t; + + /* If the received reply packet contains ANY record that is not .local or .in-addr.arpa, + * we assume someone's playing tricks on us and discard the packet completely. */ + if (!(dns_name_endswith(name, "in-addr.arpa") > 0 || + dns_name_endswith(name, "local") > 0)) + return 0; + + t = dns_scope_find_transaction(scope, rr->key, false); + if (t) + dns_transaction_process_reply(t, p); + } + + dns_cache_put(&scope->cache, NULL, DNS_PACKET_RCODE(p), p->answer, false, (uint32_t) -1, 0, p->family, &p->sender); + + } else if (dns_packet_validate_query(p) > 0) { + log_debug("Got mDNS query packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_process_query(scope, NULL, p); + } else + log_debug("Invalid mDNS UDP packet."); + + return 0; +} + +int manager_mdns_ipv4_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(MDNS_PORT), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; + int r; + + assert(m); + + if (m->mdns_ipv4_fd >= 0) + return m->mdns_ipv4_fd; + + m->mdns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->mdns_ipv4_fd < 0) + return -errno; + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* Disable Don't-Fragment bit in the IP header */ + r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->mdns_ipv4_event_source, m->mdns_ipv4_fd, EPOLLIN, on_mdns_packet, m); + if (r < 0) + goto fail; + + return m->mdns_ipv4_fd; + +fail: + m->mdns_ipv4_fd = safe_close(m->mdns_ipv4_fd); + return r; +} + +int manager_mdns_ipv6_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(MDNS_PORT), + }; + static const int one = 1, ttl = 255; + int r; + + assert(m); + + if (m->mdns_ipv6_fd >= 0) + return m->mdns_ipv6_fd; + + m->mdns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->mdns_ipv6_fd < 0) + return -errno; + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->mdns_ipv6_event_source, m->mdns_ipv6_fd, EPOLLIN, on_mdns_packet, m); + if (r < 0) + goto fail; + + return m->mdns_ipv6_fd; + +fail: + m->mdns_ipv6_fd = safe_close(m->mdns_ipv6_fd); + return r; +} diff --git a/src/resolve/resolved-mdns.h b/src/resolve/resolved-mdns.h new file mode 100644 index 0000000000..8a84010615 --- /dev/null +++ b/src/resolve/resolved-mdns.h @@ -0,0 +1,32 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2015 Daniel Mack + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +#define MDNS_PORT 5353 + +int manager_mdns_ipv4_fd(Manager *m); +int manager_mdns_ipv6_fd(Manager *m); + +void manager_mdns_stop(Manager *m); +int manager_mdns_start(Manager *m); diff --git a/src/resolve/resolved-resolv-conf.c b/src/resolve/resolved-resolv-conf.c new file mode 100644 index 0000000000..7567f4c369 --- /dev/null +++ b/src/resolve/resolved-resolv-conf.c @@ -0,0 +1,271 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <resolv.h> + +#include "alloc-util.h" +#include "dns-domain.h" +#include "fd-util.h" +#include "fileio-label.h" +#include "fileio.h" +#include "ordered-set.h" +#include "resolved-conf.h" +#include "resolved-resolv-conf.h" +#include "string-util.h" +#include "strv.h" + +int manager_read_resolv_conf(Manager *m) { + _cleanup_fclose_ FILE *f = NULL; + struct stat st, own; + char line[LINE_MAX]; + usec_t t; + int r; + + assert(m); + + /* Reads the system /etc/resolv.conf, if it exists and is not + * symlinked to our own resolv.conf instance */ + + if (!m->read_resolv_conf) + return 0; + + r = stat("/etc/resolv.conf", &st); + if (r < 0) { + if (errno == ENOENT) + return 0; + + r = log_warning_errno(errno, "Failed to stat /etc/resolv.conf: %m"); + goto clear; + } + + /* Have we already seen the file? */ + t = timespec_load(&st.st_mtim); + if (t == m->resolv_conf_mtime) + return 0; + + /* Is it symlinked to our own file? */ + if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && + st.st_dev == own.st_dev && + st.st_ino == own.st_ino) + return 0; + + f = fopen("/etc/resolv.conf", "re"); + if (!f) { + if (errno == ENOENT) + return 0; + + r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + goto clear; + } + + if (fstat(fileno(f), &st) < 0) { + r = log_error_errno(errno, "Failed to stat open file: %m"); + goto clear; + } + + dns_server_mark_all(m->dns_servers); + dns_search_domain_mark_all(m->search_domains); + + FOREACH_LINE(line, f, r = -errno; goto clear) { + const char *a; + char *l; + + l = strstrip(line); + if (*l == '#' || *l == ';') + continue; + + a = first_word(l, "nameserver"); + if (a) { + r = manager_add_dns_server_by_string(m, DNS_SERVER_SYSTEM, a); + if (r < 0) + log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a); + + continue; + } + + a = first_word(l, "domain"); + if (!a) /* We treat "domain" lines, and "search" lines as equivalent, and add both to our list. */ + a = first_word(l, "search"); + if (a) { + r = manager_parse_search_domains_and_warn(m, a); + if (r < 0) + log_warning_errno(r, "Failed to parse search domain string '%s', ignoring.", a); + } + } + + m->resolv_conf_mtime = t; + + /* Flush out all servers and search domains that are still + * marked. Those are then ones that didn't appear in the new + * /etc/resolv.conf */ + dns_server_unlink_marked(m->dns_servers); + dns_search_domain_unlink_marked(m->search_domains); + + /* Whenever /etc/resolv.conf changes, start using the first + * DNS server of it. This is useful to deal with broken + * network managing implementations (like NetworkManager), + * that when connecting to a VPN place both the VPN DNS + * servers and the local ones in /etc/resolv.conf. Without + * resetting the DNS server to use back to the first entry we + * will continue to use the local one thus being unable to + * resolve VPN domains. */ + manager_set_dns_server(m, m->dns_servers); + + /* Unconditionally flush the cache when /etc/resolv.conf is + * modified, even if the data it contained was completely + * identical to the previous version we used. We do this + * because altering /etc/resolv.conf is typically done when + * the network configuration changes, and that should be + * enough to flush the global unicast DNS cache. */ + if (m->unicast_scope) + dns_cache_flush(&m->unicast_scope->cache); + + return 0; + +clear: + dns_server_unlink_all(m->dns_servers); + dns_search_domain_unlink_all(m->search_domains); + return r; +} + +static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { + assert(s); + assert(f); + assert(count); + + (void) dns_server_string(s); + + if (!s->server_string) { + log_warning("Our of memory, or invalid DNS address. Ignoring server."); + return; + } + + if (*count == MAXNS) + fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); + (*count) ++; + + fprintf(f, "nameserver %s\n", s->server_string); +} + +static void write_resolv_conf_search( + const char *domain, + FILE *f, + unsigned *count, + unsigned *length) { + + assert(domain); + assert(f); + assert(length); + + if (*count >= MAXDNSRCH || + *length + strlen(domain) > 256) { + if (*count == MAXDNSRCH) + fputs(" # Too many search domains configured, remaining ones ignored.", f); + if (*length <= 256) + fputs(" # Total length of all search domains is too long, remaining ones ignored.", f); + + return; + } + + (*length) += strlen(domain); + (*count) ++; + + fputc(' ', f); + fputs(domain, f); +} + +static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { + Iterator i; + + fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" + "# Third party programs must not access this file directly, but\n" + "# only through the symlink at /etc/resolv.conf. To manage\n" + "# resolv.conf(5) in a different way, replace the symlink by a\n" + "# static file or a different symlink.\n\n", f); + + if (ordered_set_isempty(dns)) + fputs("# No DNS servers known.\n", f); + else { + unsigned count = 0; + DnsServer *s; + + ORDERED_SET_FOREACH(s, dns, i) + write_resolv_conf_server(s, f, &count); + } + + if (!ordered_set_isempty(domains)) { + unsigned length = 0, count = 0; + char *domain; + + fputs("search", f); + ORDERED_SET_FOREACH(domain, domains, i) + write_resolv_conf_search(domain, f, &count, &length); + fputs("\n", f); + } + + return fflush_and_check(f); +} + +int manager_write_resolv_conf(Manager *m) { + + #define PRIVATE_RESOLV_CONF "/run/systemd/resolve/resolv.conf" + + _cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL; + _cleanup_free_ char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(m); + + /* Read the system /etc/resolv.conf first */ + manager_read_resolv_conf(m); + + /* Add the full list to a set, to filter out duplicates */ + r = manager_compile_dns_servers(m, &dns); + if (r < 0) + return r; + + r = manager_compile_search_domains(m, &domains); + if (r < 0) + return r; + + r = fopen_temporary_label(PRIVATE_RESOLV_CONF, PRIVATE_RESOLV_CONF, &f, &temp_path); + if (r < 0) + return r; + + fchmod(fileno(f), 0644); + + r = write_resolv_conf_contents(f, dns, domains); + if (r < 0) + goto fail; + + if (rename(temp_path, PRIVATE_RESOLV_CONF) < 0) { + r = -errno; + goto fail; + } + + return 0; + +fail: + (void) unlink(PRIVATE_RESOLV_CONF); + (void) unlink(temp_path); + return r; +} diff --git a/src/resolve/resolved-resolv-conf.h b/src/resolve/resolved-resolv-conf.h new file mode 100644 index 0000000000..a3355e994b --- /dev/null +++ b/src/resolve/resolved-resolv-conf.h @@ -0,0 +1,27 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +int manager_read_resolv_conf(Manager *m); +int manager_write_resolv_conf(Manager *m); diff --git a/src/resolve/resolved.c b/src/resolve/resolved.c index 32e61af925..472bb32764 100644 --- a/src/resolve/resolved.c +++ b/src/resolve/resolved.c @@ -19,15 +19,17 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ -#include "sd-event.h" #include "sd-daemon.h" +#include "sd-event.h" + +#include "capability-util.h" #include "mkdir.h" -#include "capability.h" +#include "resolved-conf.h" +#include "resolved-manager.h" +#include "resolved-resolv-conf.h" #include "selinux-util.h" #include "signal-util.h" - -#include "resolved-manager.h" -#include "resolved-conf.h" +#include "user-util.h" int main(int argc, char *argv[]) { _cleanup_(manager_freep) Manager *m = NULL; @@ -79,10 +81,6 @@ int main(int argc, char *argv[]) { goto finish; } - r = manager_parse_config_file(m); - if (r < 0) - log_warning_errno(r, "Failed to parse configuration file: %m"); - r = manager_start(m); if (r < 0) { log_error_errno(r, "Failed to start manager: %m"); diff --git a/src/resolve/resolved.conf.in b/src/resolve/resolved.conf.in index 3eb19e42b7..efc9c6733a 100644 --- a/src/resolve/resolved.conf.in +++ b/src/resolve/resolved.conf.in @@ -14,4 +14,6 @@ [Resolve] #DNS= #FallbackDNS=@DNS_SERVERS@ +#Domains= #LLMNR=yes +#DNSSEC=no diff --git a/src/resolve/test-dnssec-complex.c b/src/resolve/test-dnssec-complex.c new file mode 100644 index 0000000000..caac251e83 --- /dev/null +++ b/src/resolve/test-dnssec-complex.c @@ -0,0 +1,238 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2016 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <netinet/ip.h> + +#include "sd-bus.h" + +#include "af-list.h" +#include "alloc-util.h" +#include "bus-common-errors.h" +#include "dns-type.h" +#include "random-util.h" +#include "string-util.h" +#include "time-util.h" + +#define DNS_CALL_TIMEOUT_USEC (45*USEC_PER_SEC) + +static void prefix_random(const char *name, char **ret) { + uint64_t i, u; + char *m = NULL; + + u = 1 + (random_u64() & 3); + + for (i = 0; i < u; i++) { + _cleanup_free_ char *b = NULL; + char *x; + + assert_se(asprintf(&b, "x%" PRIu64 "x", random_u64())); + x = strjoin(b, ".", name, NULL); + assert_se(x); + + free(m); + m = x; + } + + *ret = m; + } + +static void test_rr_lookup(sd_bus *bus, const char *name, uint16_t type, const char *result) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *m = NULL; + int r; + + /* If the name starts with a dot, we prefix one to three random labels */ + if (startswith(name, ".")) { + prefix_random(name + 1, &m); + name = m; + } + + assert_se(sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveRecord") >= 0); + + assert_se(sd_bus_message_append(req, "isqqt", 0, name, DNS_CLASS_IN, type, UINT64_C(0)) >= 0); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + + if (r < 0) { + assert_se(result); + assert_se(sd_bus_error_has_name(&error, result)); + log_info("[OK] %s/%s resulted in <%s>.", name, dns_type_to_string(type), error.name); + } else { + assert_se(!result); + log_info("[OK] %s/%s succeeded.", name, dns_type_to_string(type)); + } +} + +static void test_hostname_lookup(sd_bus *bus, const char *name, int family, const char *result) { + _cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *m = NULL; + const char *af; + int r; + + af = family == AF_UNSPEC ? "AF_UNSPEC" : af_to_name(family); + + /* If the name starts with a dot, we prefix one to three random labels */ + if (startswith(name, ".")) { + prefix_random(name + 1, &m); + name = m; + } + + assert_se(sd_bus_message_new_method_call( + bus, + &req, + "org.freedesktop.resolve1", + "/org/freedesktop/resolve1", + "org.freedesktop.resolve1.Manager", + "ResolveHostname") >= 0); + + assert_se(sd_bus_message_append(req, "isit", 0, name, family, UINT64_C(0)) >= 0); + + r = sd_bus_call(bus, req, DNS_CALL_TIMEOUT_USEC, &error, &reply); + + if (r < 0) { + assert_se(result); + assert_se(sd_bus_error_has_name(&error, result)); + log_info("[OK] %s/%s resulted in <%s>.", name, af, error.name); + } else { + assert_se(!result); + log_info("[OK] %s/%s succeeded.", name, af); + } + +} + +int main(int argc, char* argv[]) { + _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL; + + /* Note that this is a manual test as it requires: + * + * Full network access + * A DNSSEC capable DNS server + * That zones contacted are still set up as they were when I wrote this. + */ + + assert_se(sd_bus_open_system(&bus) >= 0); + + /* Normally signed */ + test_rr_lookup(bus, "www.eurid.eu", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, "www.eurid.eu", AF_UNSPEC, NULL); + + test_rr_lookup(bus, "sigok.verteiltesysteme.net", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, "sigok.verteiltesysteme.net", AF_UNSPEC, NULL); + + /* Normally signed, NODATA */ + test_rr_lookup(bus, "www.eurid.eu", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + test_rr_lookup(bus, "sigok.verteiltesysteme.net", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* Invalid signature */ + test_rr_lookup(bus, "sigfail.verteiltesysteme.net", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, "sigfail.verteiltesysteme.net", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* Invalid signature, RSA, wildcard */ + test_rr_lookup(bus, ".wilda.rhybar.0skar.cz", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, ".wilda.rhybar.0skar.cz", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* Invalid signature, ECDSA, wildcard */ + test_rr_lookup(bus, ".wilda.rhybar.ecdsa.0skar.cz", DNS_TYPE_A, BUS_ERROR_DNSSEC_FAILED); + test_hostname_lookup(bus, ".wilda.rhybar.ecdsa.0skar.cz", AF_INET, BUS_ERROR_DNSSEC_FAILED); + + /* NXDOMAIN in NSEC domain */ + test_rr_lookup(bus, "hhh.nasa.gov", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "hhh.nasa.gov", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + + /* wildcard, NSEC zone */ + test_rr_lookup(bus, ".wilda.nsec.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wilda.nsec.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC zone, NODATA */ + test_rr_lookup(bus, ".wilda.nsec.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC3 zone */ + test_rr_lookup(bus, ".wilda.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wilda.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC3 zone, NODATA */ + test_rr_lookup(bus, ".wilda.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC zone, CNAME */ + test_rr_lookup(bus, ".wild.nsec.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wild.nsec.0skar.cz", AF_UNSPEC, NULL); + test_hostname_lookup(bus, ".wild.nsec.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC zone, NODATA, CNAME */ + test_rr_lookup(bus, ".wild.nsec.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* wildcard, NSEC3 zone, CNAME */ + test_rr_lookup(bus, ".wild.0skar.cz", DNS_TYPE_A, NULL); + test_hostname_lookup(bus, ".wild.0skar.cz", AF_UNSPEC, NULL); + test_hostname_lookup(bus, ".wild.0skar.cz", AF_INET, NULL); + + /* wildcard, NSEC3 zone, NODATA, CNAME */ + test_rr_lookup(bus, ".wild.0skar.cz", DNS_TYPE_RP, BUS_ERROR_NO_SUCH_RR); + + /* NODATA due to empty non-terminal in NSEC domain */ + test_rr_lookup(bus, "herndon.nasa.gov", DNS_TYPE_A, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_UNSPEC, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_INET, BUS_ERROR_NO_SUCH_RR); + test_hostname_lookup(bus, "herndon.nasa.gov", AF_INET6, BUS_ERROR_NO_SUCH_RR); + + /* NXDOMAIN in NSEC root zone: */ + test_rr_lookup(bus, "jasdhjas.kjkfgjhfjg", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "jasdhjas.kjkfgjhfjg", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + + /* NXDOMAIN in NSEC3 .com zone: */ + test_rr_lookup(bus, "kjkfgjhfjgsdfdsfd.com", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, "kjkfgjhfjgsdfdsfd.com", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + + /* Unsigned A */ + test_rr_lookup(bus, "poettering.de", DNS_TYPE_A, NULL); + test_rr_lookup(bus, "poettering.de", DNS_TYPE_AAAA, NULL); + test_hostname_lookup(bus, "poettering.de", AF_UNSPEC, NULL); + test_hostname_lookup(bus, "poettering.de", AF_INET, NULL); + test_hostname_lookup(bus, "poettering.de", AF_INET6, NULL); + +#if HAVE_LIBIDN + /* Unsigned A with IDNA conversion necessary */ + test_hostname_lookup(bus, "pöttering.de", AF_UNSPEC, NULL); + test_hostname_lookup(bus, "pöttering.de", AF_INET, NULL); + test_hostname_lookup(bus, "pöttering.de", AF_INET6, NULL); +#endif + + /* DNAME, pointing to NXDOMAIN */ + test_rr_lookup(bus, ".ireallyhpoethisdoesnexist.xn--kprw13d.", DNS_TYPE_A, _BUS_ERROR_DNS "NXDOMAIN"); + test_rr_lookup(bus, ".ireallyhpoethisdoesnexist.xn--kprw13d.", DNS_TYPE_RP, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_UNSPEC, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_INET, _BUS_ERROR_DNS "NXDOMAIN"); + test_hostname_lookup(bus, ".ireallyhpoethisdoesntexist.xn--kprw13d.", AF_INET6, _BUS_ERROR_DNS "NXDOMAIN"); + + return 0; +} diff --git a/src/resolve/test-dnssec.c b/src/resolve/test-dnssec.c new file mode 100644 index 0000000000..45fe1997e2 --- /dev/null +++ b/src/resolve/test-dnssec.c @@ -0,0 +1,338 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <arpa/inet.h> +#include <netinet/in.h> +#include <sys/socket.h> + +#include "alloc-util.h" +#include "resolved-dns-dnssec.h" +#include "resolved-dns-rr.h" +#include "string-util.h" +#include "hexdecoct.h" + +static void test_dnssec_verify_rrset2(void) { + + static const uint8_t signature_blob[] = { + 0x48, 0x45, 0xc8, 0x8b, 0xc0, 0x14, 0x92, 0xf5, 0x15, 0xc6, 0x84, 0x9d, 0x2f, 0xe3, 0x32, 0x11, + 0x7d, 0xf1, 0xe6, 0x87, 0xb9, 0x42, 0xd3, 0x8b, 0x9e, 0xaf, 0x92, 0x31, 0x0a, 0x53, 0xad, 0x8b, + 0xa7, 0x5c, 0x83, 0x39, 0x8c, 0x28, 0xac, 0xce, 0x6e, 0x9c, 0x18, 0xe3, 0x31, 0x16, 0x6e, 0xca, + 0x38, 0x31, 0xaf, 0xd9, 0x94, 0xf1, 0x84, 0xb1, 0xdf, 0x5a, 0xc2, 0x73, 0x22, 0xf6, 0xcb, 0xa2, + 0xe7, 0x8c, 0x77, 0x0c, 0x74, 0x2f, 0xc2, 0x13, 0xb0, 0x93, 0x51, 0xa9, 0x4f, 0xae, 0x0a, 0xda, + 0x45, 0xcc, 0xfd, 0x43, 0x99, 0x36, 0x9a, 0x0d, 0x21, 0xe0, 0xeb, 0x30, 0x65, 0xd4, 0xa0, 0x27, + 0x37, 0x3b, 0xe4, 0xc1, 0xc5, 0xa1, 0x2a, 0xd1, 0x76, 0xc4, 0x7e, 0x64, 0x0e, 0x5a, 0xa6, 0x50, + 0x24, 0xd5, 0x2c, 0xcc, 0x6d, 0xe5, 0x37, 0xea, 0xbd, 0x09, 0x34, 0xed, 0x24, 0x06, 0xa1, 0x22, + }; + + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0xc3, 0x7f, 0x1d, 0xd1, 0x1c, 0x97, 0xb1, 0x13, 0x34, 0x3a, 0x9a, 0xea, + 0xee, 0xd9, 0x5a, 0x11, 0x1b, 0x17, 0xc7, 0xe3, 0xd4, 0xda, 0x20, 0xbc, 0x5d, 0xba, 0x74, 0xe3, + 0x37, 0x99, 0xec, 0x25, 0xce, 0x93, 0x7f, 0xbd, 0x22, 0x73, 0x7e, 0x14, 0x71, 0xe0, 0x60, 0x07, + 0xd4, 0x39, 0x8b, 0x5e, 0xe9, 0xba, 0x25, 0xe8, 0x49, 0xe9, 0x34, 0xef, 0xfe, 0x04, 0x5c, 0xa5, + 0x27, 0xcd, 0xa9, 0xda, 0x70, 0x05, 0x21, 0xab, 0x15, 0x82, 0x24, 0xc3, 0x94, 0xf5, 0xd7, 0xb7, + 0xc4, 0x66, 0xcb, 0x32, 0x6e, 0x60, 0x2b, 0x55, 0x59, 0x28, 0x89, 0x8a, 0x72, 0xde, 0x88, 0x56, + 0x27, 0x95, 0xd9, 0xac, 0x88, 0x4f, 0x65, 0x2b, 0x68, 0xfc, 0xe6, 0x41, 0xc1, 0x1b, 0xef, 0x4e, + 0xd6, 0xc2, 0x0f, 0x64, 0x88, 0x95, 0x5e, 0xdd, 0x3a, 0x02, 0x07, 0x50, 0xa9, 0xda, 0xa4, 0x49, + 0x74, 0x62, 0xfe, 0xd7, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *nsec = NULL, *rrsig = NULL, *dnskey = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnssecResult result; + + nsec = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_NSEC, "nasa.gov"); + assert_se(nsec); + + nsec->nsec.next_domain_name = strdup("3D-Printing.nasa.gov"); + assert_se(nsec->nsec.next_domain_name); + + nsec->nsec.types = bitmap_new(); + assert_se(nsec->nsec.types); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_A) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_NS) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_SOA) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_MX) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_TXT) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_RRSIG) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_NSEC) >= 0); + assert_se(bitmap_set(nsec->nsec.types, DNS_TYPE_DNSKEY) >= 0); + assert_se(bitmap_set(nsec->nsec.types, 65534) >= 0); + + log_info("NSEC: %s", strna(dns_resource_record_to_string(nsec))); + + rrsig = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_RRSIG, "NaSa.GOV."); + assert_se(rrsig); + + rrsig->rrsig.type_covered = DNS_TYPE_NSEC; + rrsig->rrsig.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rrsig->rrsig.labels = 2; + rrsig->rrsig.original_ttl = 300; + rrsig->rrsig.expiration = 0x5689002f; + rrsig->rrsig.inception = 0x56617230; + rrsig->rrsig.key_tag = 30390; + rrsig->rrsig.signer = strdup("Nasa.Gov."); + assert_se(rrsig->rrsig.signer); + rrsig->rrsig.signature_size = sizeof(signature_blob); + rrsig->rrsig.signature = memdup(signature_blob, rrsig->rrsig.signature_size); + assert_se(rrsig->rrsig.signature); + + log_info("RRSIG: %s", strna(dns_resource_record_to_string(rrsig))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nASA.gOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 256; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_key_match_rrsig(nsec->key, rrsig) > 0); + assert_se(dnssec_rrsig_match_dnskey(rrsig, dnskey, false) > 0); + + answer = dns_answer_new(1); + assert_se(answer); + assert_se(dns_answer_add(answer, nsec, 0, DNS_ANSWER_AUTHENTICATED) >= 0); + + /* Validate the RR as it if was 2015-12-11 today */ + assert_se(dnssec_verify_rrset(answer, nsec->key, rrsig, dnskey, 1449849318*USEC_PER_SEC, &result) >= 0); + assert_se(result == DNSSEC_VALIDATED); +} + +static void test_dnssec_verify_rrset(void) { + + static const uint8_t signature_blob[] = { + 0x7f, 0x79, 0xdd, 0x5e, 0x89, 0x79, 0x18, 0xd0, 0x34, 0x86, 0x8c, 0x72, 0x77, 0x75, 0x48, 0x4d, + 0xc3, 0x7d, 0x38, 0x04, 0xab, 0xcd, 0x9e, 0x4c, 0x82, 0xb0, 0x92, 0xca, 0xe9, 0x66, 0xe9, 0x6e, + 0x47, 0xc7, 0x68, 0x8c, 0x94, 0xf6, 0x69, 0xcb, 0x75, 0x94, 0xe6, 0x30, 0xa6, 0xfb, 0x68, 0x64, + 0x96, 0x1a, 0x84, 0xe1, 0xdc, 0x16, 0x4c, 0x83, 0x6c, 0x44, 0xf2, 0x74, 0x4d, 0x74, 0x79, 0x8f, + 0xf3, 0xf4, 0x63, 0x0d, 0xef, 0x5a, 0xe7, 0xe2, 0xfd, 0xf2, 0x2b, 0x38, 0x7c, 0x28, 0x96, 0x9d, + 0xb6, 0xcd, 0x5c, 0x3b, 0x57, 0xe2, 0x24, 0x78, 0x65, 0xd0, 0x9e, 0x77, 0x83, 0x09, 0x6c, 0xff, + 0x3d, 0x52, 0x3f, 0x6e, 0xd1, 0xed, 0x2e, 0xf9, 0xee, 0x8e, 0xa6, 0xbe, 0x9a, 0xa8, 0x87, 0x76, + 0xd8, 0x77, 0xcc, 0x96, 0xa0, 0x98, 0xa1, 0xd1, 0x68, 0x09, 0x43, 0xcf, 0x56, 0xd9, 0xd1, 0x66, + }; + + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0x9b, 0x49, 0x9b, 0xc1, 0xf9, 0x9a, 0xe0, 0x4e, 0xcf, 0xcb, 0x14, 0x45, + 0x2e, 0xc9, 0xf9, 0x74, 0xa7, 0x18, 0xb5, 0xf3, 0xde, 0x39, 0x49, 0xdf, 0x63, 0x33, 0x97, 0x52, + 0xe0, 0x8e, 0xac, 0x50, 0x30, 0x8e, 0x09, 0xd5, 0x24, 0x3d, 0x26, 0xa4, 0x49, 0x37, 0x2b, 0xb0, + 0x6b, 0x1b, 0xdf, 0xde, 0x85, 0x83, 0xcb, 0x22, 0x4e, 0x60, 0x0a, 0x91, 0x1a, 0x1f, 0xc5, 0x40, + 0xb1, 0xc3, 0x15, 0xc1, 0x54, 0x77, 0x86, 0x65, 0x53, 0xec, 0x10, 0x90, 0x0c, 0x91, 0x00, 0x5e, + 0x15, 0xdc, 0x08, 0x02, 0x4c, 0x8c, 0x0d, 0xc0, 0xac, 0x6e, 0xc4, 0x3e, 0x1b, 0x80, 0x19, 0xe4, + 0xf7, 0x5f, 0x77, 0x51, 0x06, 0x87, 0x61, 0xde, 0xa2, 0x18, 0x0f, 0x40, 0x8b, 0x79, 0x72, 0xfa, + 0x8d, 0x1a, 0x44, 0x47, 0x0d, 0x8e, 0x3a, 0x2d, 0xc7, 0x39, 0xbf, 0x56, 0x28, 0x97, 0xd9, 0x20, + 0x4f, 0x00, 0x51, 0x3b, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *a = NULL, *rrsig = NULL, *dnskey = NULL; + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + DnssecResult result; + + a = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, "nAsA.gov"); + assert_se(a); + + a->a.in_addr.s_addr = inet_addr("52.0.14.116"); + + log_info("A: %s", strna(dns_resource_record_to_string(a))); + + rrsig = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_RRSIG, "NaSa.GOV."); + assert_se(rrsig); + + rrsig->rrsig.type_covered = DNS_TYPE_A; + rrsig->rrsig.algorithm = DNSSEC_ALGORITHM_RSASHA256; + rrsig->rrsig.labels = 2; + rrsig->rrsig.original_ttl = 600; + rrsig->rrsig.expiration = 0x5683135c; + rrsig->rrsig.inception = 0x565b7da8; + rrsig->rrsig.key_tag = 63876; + rrsig->rrsig.signer = strdup("Nasa.Gov."); + assert_se(rrsig->rrsig.signer); + rrsig->rrsig.signature_size = sizeof(signature_blob); + rrsig->rrsig.signature = memdup(signature_blob, rrsig->rrsig.signature_size); + assert_se(rrsig->rrsig.signature); + + log_info("RRSIG: %s", strna(dns_resource_record_to_string(rrsig))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nASA.gOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 256; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_key_match_rrsig(a->key, rrsig) > 0); + assert_se(dnssec_rrsig_match_dnskey(rrsig, dnskey, false) > 0); + + answer = dns_answer_new(1); + assert_se(answer); + assert_se(dns_answer_add(answer, a, 0, DNS_ANSWER_AUTHENTICATED) >= 0); + + /* Validate the RR as it if was 2015-12-2 today */ + assert_se(dnssec_verify_rrset(answer, a->key, rrsig, dnskey, 1449092754*USEC_PER_SEC, &result) >= 0); + assert_se(result == DNSSEC_VALIDATED); +} + +static void test_dnssec_verify_dns_key(void) { + + static const uint8_t ds1_fprint[] = { + 0x46, 0x8B, 0xC8, 0xDD, 0xC7, 0xE8, 0x27, 0x03, 0x40, 0xBB, 0x8A, 0x1F, 0x3B, 0x2E, 0x45, 0x9D, + 0x80, 0x67, 0x14, 0x01, + }; + static const uint8_t ds2_fprint[] = { + 0x8A, 0xEE, 0x80, 0x47, 0x05, 0x5F, 0x83, 0xD1, 0x48, 0xBA, 0x8F, 0xF6, 0xDD, 0xA7, 0x60, 0xCE, + 0x94, 0xF7, 0xC7, 0x5E, 0x52, 0x4C, 0xF2, 0xE9, 0x50, 0xB9, 0x2E, 0xCB, 0xEF, 0x96, 0xB9, 0x98, + }; + static const uint8_t dnskey_blob[] = { + 0x03, 0x01, 0x00, 0x01, 0xa8, 0x12, 0xda, 0x4f, 0xd2, 0x7d, 0x54, 0x14, 0x0e, 0xcc, 0x5b, 0x5e, + 0x45, 0x9c, 0x96, 0x98, 0xc0, 0xc0, 0x85, 0x81, 0xb1, 0x47, 0x8c, 0x7d, 0xe8, 0x39, 0x50, 0xcc, + 0xc5, 0xd0, 0xf2, 0x00, 0x81, 0x67, 0x79, 0xf6, 0xcc, 0x9d, 0xad, 0x6c, 0xbb, 0x7b, 0x6f, 0x48, + 0x97, 0x15, 0x1c, 0xfd, 0x0b, 0xfe, 0xd3, 0xd7, 0x7d, 0x9f, 0x81, 0x26, 0xd3, 0xc5, 0x65, 0x49, + 0xcf, 0x46, 0x62, 0xb0, 0x55, 0x6e, 0x47, 0xc7, 0x30, 0xef, 0x51, 0xfb, 0x3e, 0xc6, 0xef, 0xde, + 0x27, 0x3f, 0xfa, 0x57, 0x2d, 0xa7, 0x1d, 0x80, 0x46, 0x9a, 0x5f, 0x14, 0xb3, 0xb0, 0x2c, 0xbe, + 0x72, 0xca, 0xdf, 0xb2, 0xff, 0x36, 0x5b, 0x4f, 0xec, 0x58, 0x8e, 0x8d, 0x01, 0xe9, 0xa9, 0xdf, + 0xb5, 0x60, 0xad, 0x52, 0x4d, 0xfc, 0xa9, 0x3e, 0x8d, 0x35, 0x95, 0xb3, 0x4e, 0x0f, 0xca, 0x45, + 0x1b, 0xf7, 0xef, 0x3a, 0x88, 0x25, 0x08, 0xc7, 0x4e, 0x06, 0xc1, 0x62, 0x1a, 0xce, 0xd8, 0x77, + 0xbd, 0x02, 0x65, 0xf8, 0x49, 0xfb, 0xce, 0xf6, 0xa8, 0x09, 0xfc, 0xde, 0xb2, 0x09, 0x9d, 0x39, + 0xf8, 0x63, 0x9c, 0x32, 0x42, 0x7c, 0xa0, 0x30, 0x86, 0x72, 0x7a, 0x4a, 0xc6, 0xd4, 0xb3, 0x2d, + 0x24, 0xef, 0x96, 0x3f, 0xc2, 0xda, 0xd3, 0xf2, 0x15, 0x6f, 0xda, 0x65, 0x4b, 0x81, 0x28, 0x68, + 0xf4, 0xfe, 0x3e, 0x71, 0x4f, 0x50, 0x96, 0x72, 0x58, 0xa1, 0x89, 0xdd, 0x01, 0x61, 0x39, 0x39, + 0xc6, 0x76, 0xa4, 0xda, 0x02, 0x70, 0x3d, 0xc0, 0xdc, 0x8d, 0x70, 0x72, 0x04, 0x90, 0x79, 0xd4, + 0xec, 0x65, 0xcf, 0x49, 0x35, 0x25, 0x3a, 0x14, 0x1a, 0x45, 0x20, 0xeb, 0x31, 0xaf, 0x92, 0xba, + 0x20, 0xd3, 0xcd, 0xa7, 0x13, 0x44, 0xdc, 0xcf, 0xf0, 0x27, 0x34, 0xb9, 0xe7, 0x24, 0x6f, 0x73, + 0xe7, 0xea, 0x77, 0x03, + }; + + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *dnskey = NULL, *ds1 = NULL, *ds2 = NULL; + + /* The two DS RRs in effect for nasa.gov on 2015-12-01. */ + ds1 = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, "nasa.gov"); + assert_se(ds1); + + ds1->ds.key_tag = 47857; + ds1->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + ds1->ds.digest_type = DNSSEC_DIGEST_SHA1; + ds1->ds.digest_size = sizeof(ds1_fprint); + ds1->ds.digest = memdup(ds1_fprint, ds1->ds.digest_size); + assert_se(ds1->ds.digest); + + log_info("DS1: %s", strna(dns_resource_record_to_string(ds1))); + + ds2 = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DS, "NASA.GOV"); + assert_se(ds2); + + ds2->ds.key_tag = 47857; + ds2->ds.algorithm = DNSSEC_ALGORITHM_RSASHA256; + ds2->ds.digest_type = DNSSEC_DIGEST_SHA256; + ds2->ds.digest_size = sizeof(ds2_fprint); + ds2->ds.digest = memdup(ds2_fprint, ds2->ds.digest_size); + assert_se(ds2->ds.digest); + + log_info("DS2: %s", strna(dns_resource_record_to_string(ds2))); + + dnskey = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_DNSKEY, "nasa.GOV"); + assert_se(dnskey); + + dnskey->dnskey.flags = 257; + dnskey->dnskey.protocol = 3; + dnskey->dnskey.algorithm = DNSSEC_ALGORITHM_RSASHA256; + dnskey->dnskey.key_size = sizeof(dnskey_blob); + dnskey->dnskey.key = memdup(dnskey_blob, sizeof(dnskey_blob)); + assert_se(dnskey->dnskey.key); + + log_info("DNSKEY: %s", strna(dns_resource_record_to_string(dnskey))); + log_info("DNSKEY keytag: %u", dnssec_keytag(dnskey, false)); + + assert_se(dnssec_verify_dnskey_by_ds(dnskey, ds1, false) > 0); + assert_se(dnssec_verify_dnskey_by_ds(dnskey, ds2, false) > 0); +} + +static void test_dnssec_canonicalize_one(const char *original, const char *canonical, int r) { + char canonicalized[DNSSEC_CANONICAL_HOSTNAME_MAX]; + + assert_se(dnssec_canonicalize(original, canonicalized, sizeof(canonicalized)) == r); + if (r < 0) + return; + + assert_se(streq(canonicalized, canonical)); +} + +static void test_dnssec_canonicalize(void) { + test_dnssec_canonicalize_one("", ".", 1); + test_dnssec_canonicalize_one(".", ".", 1); + test_dnssec_canonicalize_one("foo", "foo.", 4); + test_dnssec_canonicalize_one("foo.", "foo.", 4); + test_dnssec_canonicalize_one("FOO.", "foo.", 4); + test_dnssec_canonicalize_one("FOO.bar.", "foo.bar.", 8); + test_dnssec_canonicalize_one("FOO..bar.", NULL, -EINVAL); +} + +static void test_dnssec_nsec3_hash(void) { + static const uint8_t salt[] = { 0xB0, 0x1D, 0xFA, 0xCE }; + static const uint8_t next_hashed_name[] = { 0x84, 0x10, 0x26, 0x53, 0xc9, 0xfa, 0x4d, 0x85, 0x6c, 0x97, 0x82, 0xe2, 0x8f, 0xdf, 0x2d, 0x5e, 0x87, 0x69, 0xc4, 0x52 }; + _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; + uint8_t h[DNSSEC_HASH_SIZE_MAX]; + _cleanup_free_ char *b = NULL; + int k; + + /* The NSEC3 RR for eurid.eu on 2015-12-14. */ + rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_NSEC3, "PJ8S08RR45VIQDAQGE7EN3VHKNROTBMM.eurid.eu."); + assert_se(rr); + + rr->nsec3.algorithm = DNSSEC_DIGEST_SHA1; + rr->nsec3.flags = 1; + rr->nsec3.iterations = 1; + rr->nsec3.salt = memdup(salt, sizeof(salt)); + assert_se(rr->nsec3.salt); + rr->nsec3.salt_size = sizeof(salt); + rr->nsec3.next_hashed_name = memdup(next_hashed_name, sizeof(next_hashed_name)); + assert_se(rr->nsec3.next_hashed_name); + rr->nsec3.next_hashed_name_size = sizeof(next_hashed_name); + + log_info("NSEC3: %s", strna(dns_resource_record_to_string(rr))); + + k = dnssec_nsec3_hash(rr, "eurid.eu", &h); + assert_se(k >= 0); + + b = base32hexmem(h, k, false); + assert_se(b); + assert_se(strcasecmp(b, "PJ8S08RR45VIQDAQGE7EN3VHKNROTBMM") == 0); +} + +int main(int argc, char*argv[]) { + + test_dnssec_canonicalize(); + test_dnssec_verify_dns_key(); + test_dnssec_verify_rrset(); + test_dnssec_verify_rrset2(); + test_dnssec_nsec3_hash(); + + return 0; +} |