diff options
Diffstat (limited to 'src/resolve/resolved-dns-query.c')
-rw-r--r-- | src/resolve/resolved-dns-query.c | 703 |
1 files changed, 273 insertions, 430 deletions
diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c index 1948d59fc4..a00851658e 100644 --- a/src/resolve/resolved-dns-query.c +++ b/src/resolve/resolved-dns-query.c @@ -24,6 +24,9 @@ #include "hostname-util.h" #include "local-addresses.h" #include "resolved-dns-query.h" +#include "resolved-dns-synthesize.h" +#include "resolved-etc-hosts.h" +#include "string-util.h" /* How long to wait for the query in total */ #define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC) @@ -90,17 +93,20 @@ static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) { assert(c); - if (c->search_domain && c->search_domain->linked) { + if (c->search_domain && c->search_domain->linked) next = c->search_domain->domains_next; + else + next = dns_scope_get_search_domains(c->scope); + for (;;) { if (!next) /* We hit the end of the list */ return 0; - } else { - next = dns_scope_get_search_domains(c->scope); + if (!next->route_only) + break; - if (!next) /* OK, there's nothing. */ - return 0; + /* Skip over route-only domains */ + next = next->domains_next; } dns_search_domain_unref(c->search_domain); @@ -179,7 +185,7 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { assert(c); if (c->error_code != 0) - return DNS_TRANSACTION_RESOURCES; + return DNS_TRANSACTION_ERRNO; SET_FOREACH(t, c->transactions, i) { @@ -217,6 +223,7 @@ static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { } static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { + DnsQuestion *question; DnsResourceKey *key; int n = 0, r; @@ -224,8 +231,10 @@ static int dns_query_candidate_setup_transactions(DnsQueryCandidate *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, c->query->question) { + DNS_QUESTION_FOREACH(key, question) { _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL; if (c->search_domain) { @@ -305,6 +314,26 @@ static void dns_query_stop(DnsQuery *q) { dns_query_candidate_stop(c); } +static void dns_query_free_candidates(DnsQuery *q) { + assert(q); + + while (q->candidates) + dns_query_candidate_free(q->candidates); +} + +static void dns_query_reset_answer(DnsQuery *q) { + assert(q); + + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = 0; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_errno = 0; + q->answer_authenticated = false; + q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; + q->answer_search_domain = dns_search_domain_unref(q->answer_search_domain); +} + DnsQuery *dns_query_free(DnsQuery *q) { if (!q) return NULL; @@ -318,16 +347,18 @@ DnsQuery *dns_query_free(DnsQuery *q) { LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q); } - while (q->candidates) - dns_query_candidate_free(q->candidates); + dns_query_free_candidates(q); - dns_question_unref(q->question); - dns_answer_unref(q->answer); - dns_search_domain_unref(q->answer_search_domain); + 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--; @@ -338,17 +369,50 @@ 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_for_query(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; @@ -357,20 +421,40 @@ 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_family = AF_UNSPEC; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; q->answer_protocol = _DNS_PROTOCOL_INVALID; + q->answer_family = AF_UNSPEC; + + /* First dump UTF8 question */ + DNS_QUESTION_FOREACH(key, question_utf8) { + _cleanup_free_ char *p = NULL; + + r = dns_resource_key_to_string(key, &p); + if (r < 0) + return r; - for (i = 0; i < question->n_keys; i++) { - _cleanup_free_ char *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(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 IDNA RR for %s.", strstrip(p)); } LIST_PREPEND(queries, m->dns_queries, q); @@ -446,7 +530,7 @@ static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) { /* 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)); + r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question_idna)); if (r < 0) goto fail; if (r > 0) { @@ -469,413 +553,73 @@ fail: return r; } -static int SYNTHESIZE_IFINDEX(int ifindex) { - - /* When the caller asked for resolving on a specific - * interface, we synthesize the answer for that - * interface. However, if nothing specific was claimed and we - * only return localhost RRs, we synthesize the answer for - * localhost. */ - - if (ifindex > 0) - return ifindex; - - return LOOPBACK_IFINDEX; -} - -static int SYNTHESIZE_FAMILY(uint64_t flags) { - - /* Picks an address family depending on set flags. This is - * purely for synthesized answers, where the family we return - * for the reply should match what was requested in the - * question, even though we are synthesizing the answer - * here. */ - - if (!(flags & SD_RESOLVED_DNS)) { - if (flags & SD_RESOLVED_LLMNR_IPV4) - return AF_INET; - if (flags & SD_RESOLVED_LLMNR_IPV6) - return AF_INET6; - } - - return AF_UNSPEC; -} - -static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) { - - /* Similar as SYNTHESIZE_FAMILY() but does this for the - * protocol. If resolving via DNS was requested, we claim it - * was DNS. Similar, if nothing specific was - * requested. However, if only resolving via LLMNR was - * requested we return that. */ - - if (flags & SD_RESOLVED_DNS) - return DNS_PROTOCOL_DNS; - if (flags & SD_RESOLVED_LLMNR) - return DNS_PROTOCOL_LLMNR; - - return DNS_PROTOCOL_DNS; -} - -static int dns_type_to_af(uint16_t t) { - switch (t) { - - case DNS_TYPE_A: - return AF_INET; - - case DNS_TYPE_AAAA: - return AF_INET6; - - case DNS_TYPE_ANY: - return AF_UNSPEC; - - default: - return -EINVAL; - } -} - -static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { - int r; - - assert(q); - assert(key); - assert(answer); - - r = dns_answer_reserve(answer, 2); - if (r < 0) - return r; - - if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key)); - if (!rr) - return -ENOMEM; - - rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK); - - r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - } - - if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key)); - if (!rr) - return -ENOMEM; - - rr->aaaa.in6_addr = in6addr_loopback; - - r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - } - - return 0; -} - -static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex, DnsAnswerFlags flags) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from); - if (!rr) - return -ENOMEM; - - rr->ptr.name = strdup(to); - if (!rr->ptr.name) - return -ENOMEM; - - return dns_answer_add(*answer, rr, ifindex, flags); -} - -static int synthesize_localhost_ptr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { - int r; - - assert(q); - assert(key); - assert(answer); - - if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) { - r = dns_answer_reserve(answer, 1); - if (r < 0) - return r; - - r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex), DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - } - - return 0; -} - -static int answer_add_addresses_rr( - DnsAnswer **answer, - const char *name, - struct local_address *addresses, - unsigned n_addresses) { - - unsigned j; - int r; - - assert(answer); - assert(name); - - r = dns_answer_reserve(answer, n_addresses); - if (r < 0) - return r; - - for (j = 0; j < n_addresses; j++) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name); - if (r < 0) - return r; - - r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - } - - return 0; -} - -static int answer_add_addresses_ptr( - DnsAnswer **answer, - const char *name, - struct local_address *addresses, - unsigned n_addresses, - int af, const union in_addr_union *match) { - - unsigned j; - int r; - - assert(answer); - assert(name); - - for (j = 0; j < n_addresses; j++) { - _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; - - if (af != AF_UNSPEC) { - - if (addresses[j].family != af) - continue; - - if (match && !in_addr_equal(af, match, &addresses[j].address)) - continue; - } - - r = dns_answer_reserve(answer, 1); - if (r < 0) - return r; - - r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name); - if (r < 0) - return r; - - r = dns_answer_add(*answer, rr, addresses[j].ifindex, DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - } - - return 0; -} - -static int synthesize_system_hostname_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { - _cleanup_free_ struct local_address *addresses = NULL; - int n = 0, af; - - assert(q); - assert(key); - assert(answer); - - af = dns_type_to_af(key->type); - if (af >= 0) { - n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses); - if (n < 0) - return n; - - if (n == 0) { - struct local_address buffer[2]; - - /* If we have no local addresses then use ::1 - * and 127.0.0.2 as local ones. */ - - if (af == AF_INET || af == AF_UNSPEC) - buffer[n++] = (struct local_address) { - .family = AF_INET, - .ifindex = SYNTHESIZE_IFINDEX(q->ifindex), - .address.in.s_addr = htobe32(0x7F000002), - }; - - if (af == AF_INET6 || af == AF_UNSPEC) - buffer[n++] = (struct local_address) { - .family = AF_INET6, - .ifindex = SYNTHESIZE_IFINDEX(q->ifindex), - .address.in6 = in6addr_loopback, - }; - - return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n); - } - } - - return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n); -} - -static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) { - _cleanup_free_ struct local_address *addresses = NULL; - int n, r; - - assert(q); - assert(address); - assert(answer); - - if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) { - - /* Always map the IPv4 address 127.0.0.2 to the local - * hostname, in addition to "localhost": */ - - r = dns_answer_reserve(answer, 3); - if (r < 0) - return r; - - r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", 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), 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), DNS_ANSWER_AUTHENTICATED); - if (r < 0) - return r; - - return 0; - } - - n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses); - if (n < 0) - return n; - - r = answer_add_addresses_ptr(answer, q->manager->llmnr_hostname, addresses, n, af, address); - if (r < 0) - return r; - - 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) { - _cleanup_free_ struct local_address *addresses = NULL; - int n = 0, af; - - assert(q); - assert(key); - assert(answer); - - af = dns_type_to_af(key->type); - if (af >= 0) { - n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses); - if (n < 0) - return n; - } - - return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n); -} - -static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) { - _cleanup_free_ struct local_address *addresses = NULL; - int n; - - assert(q); - assert(address); - assert(answer); - - n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses); - if (n < 0) - return n; - - return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address); -} - static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; - unsigned i; int r; assert(q); assert(state); - /* Tries to synthesize localhost RR replies where appropriate */ + /* Tries to synthesize localhost RR replies (and others) where appropriate. Note that this is done *after* the + * the normal lookup finished. The data from the network hence takes precedence over the data we + * synthesize. (But note that many scopes refuse to resolve certain domain names) */ if (!IN_SET(*state, DNS_TRANSACTION_RCODE_FAILURE, DNS_TRANSACTION_NO_SERVERS, DNS_TRANSACTION_TIMEOUT, - DNS_TRANSACTION_ATTEMPTS_MAX_REACHED)) + DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, + DNS_TRANSACTION_NETWORK_DOWN, + DNS_TRANSACTION_NOT_FOUND)) return 0; - for (i = 0; i < q->question->n_keys; i++) { - 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) - continue; - - name = DNS_RESOURCE_KEY_NAME(q->question->keys[i]); - - if (is_localhost(name)) { + r = dns_synthesize_answer( + q->manager, + q->question_utf8, + q->ifindex, + &answer); - r = synthesize_localhost_rr(q, q->question->keys[i], &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize localhost RRs: %m"); + if (r <= 0) + return r; - } else if (manager_is_own_hostname(q->manager, name)) { + dns_query_reset_answer(q); - r = synthesize_system_hostname_rr(q, q->question->keys[i], &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize system hostname RRs: %m"); - - } else if (is_gateway_hostname(name)) { + q->answer = answer; + answer = NULL; + q->answer_rcode = DNS_RCODE_SUCCESS; + q->answer_protocol = dns_synthesize_protocol(q->flags); + q->answer_family = dns_synthesize_family(q->flags); + q->answer_authenticated = true; - r = synthesize_gateway_rr(q, q->question->keys[i], &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize gateway RRs: %m"); + *state = DNS_TRANSACTION_SUCCESS; - } 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) { + return 1; +} - r = synthesize_localhost_ptr(q, q->question->keys[i], &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m"); +static int dns_query_try_etc_hosts(DnsQuery *q) { + _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; + int r; - } else if (dns_name_address(name, &af, &address) > 0) { + assert(q); - r = synthesize_system_hostname_ptr(q, af, &address, &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m"); + /* Looks in /etc/hosts for matching entries. Note that this is done *before* the normal lookup is done. The + * data from /etc/hosts hence takes precedence over the network. */ - r = synthesize_gateway_ptr(q, af, &address, &answer); - if (r < 0) - return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m"); - } - } + r = manager_etc_hosts_lookup( + q->manager, + q->question_utf8, + &answer); + if (r <= 0) + return r; - if (!answer) - return 0; + dns_query_reset_answer(q); - dns_answer_unref(q->answer); q->answer = answer; answer = NULL; - q->answer_rcode = DNS_RCODE_SUCCESS; - q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags); - q->answer_family = SYNTHESIZE_FAMILY(q->flags); - - *state = DNS_TRANSACTION_SUCCESS; + q->answer_protocol = dns_synthesize_protocol(q->flags); + q->answer_family = dns_synthesize_family(q->flags); + q->answer_authenticated = true; return 1; } @@ -884,7 +628,6 @@ int dns_query_go(DnsQuery *q) { DnsScopeMatch found = DNS_SCOPE_NO; DnsScope *s, *first = NULL; DnsQueryCandidate *c; - const char *name; int r; assert(q); @@ -892,13 +635,21 @@ 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_question_first_name(q->question); + r = dns_query_try_etc_hosts(q); + if (r < 0) + return r; + if (r > 0) { + dns_query_complete(q, DNS_TRANSACTION_SUCCESS); + return 1; + } LIST_FOREACH(scopes, s, q->manager->dns_scopes) { DnsScopeMatch match; + const char *name; + + name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol)); + if (!name) + continue; match = dns_scope_good_domain(s, q->ifindex, q->flags, name); if (match < 0) @@ -923,7 +674,10 @@ int dns_query_go(DnsQuery *q) { if (found == DNS_SCOPE_NO) { DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; - dns_query_synthesize_reply(q, &state); + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + return r; + dns_query_complete(q, state); return 1; } @@ -934,6 +688,11 @@ int dns_query_go(DnsQuery *q) { 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) @@ -947,10 +706,7 @@ int dns_query_go(DnsQuery *q) { goto fail; } - q->answer = dns_answer_unref(q->answer); - q->answer_rcode = 0; - q->answer_family = AF_UNSPEC; - q->answer_protocol = _DNS_PROTOCOL_INVALID; + dns_query_reset_answer(q); r = sd_event_add_time( q->manager->event, @@ -996,11 +752,23 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { assert(q); if (!c) { - dns_query_synthesize_reply(q, &state); + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + goto fail; + dns_query_complete(q, state); return; } + if (c->error_code != 0) { + /* If the candidate had an error condition of its own, start with that. */ + state = DNS_TRANSACTION_ERRNO; + q->answer = dns_answer_unref(q->answer); + q->answer_rcode = 0; + q->answer_dnssec_result = _DNSSEC_RESULT_INVALID; + q->answer_errno = c->error_code; + } + SET_FOREACH(t, c->transactions, i) { switch (t->state) { @@ -1008,12 +776,11 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { 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 (r < 0) + goto fail; q->answer_rcode = t->answer_rcode; + q->answer_errno = 0; if (t->answer_authenticated) { has_authenticated = true; @@ -1044,6 +811,7 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { q->answer = dns_answer_unref(q->answer); q->answer_rcode = t->answer_rcode; q->answer_dnssec_result = t->answer_dnssec_result; + q->answer_errno = t->answer_errno; state = t->state; break; @@ -1061,8 +829,16 @@ static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { 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); + r = dns_query_synthesize_reply(q, &state); + if (r < 0) + goto fail; + dns_query_complete(q, state); + return; + +fail: + q->answer_errno = -r; + dns_query_complete(q, DNS_TRANSACTION_ERRNO); } void dns_query_ready(DnsQuery *q) { @@ -1115,33 +891,60 @@ void dns_query_ready(DnsQuery *q) { } static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) { - _cleanup_(dns_question_unrefp) DnsQuestion *nq = NULL; - int r; + _cleanup_(dns_question_unrefp) DnsQuestion *nq_idna = NULL, *nq_utf8 = NULL; + int r, k; assert(q); - log_debug("Following CNAME %s → %s", dns_question_first_name(q->question), cname->cname.name); - q->n_cname_redirects ++; if (q->n_cname_redirects > CNAME_MAX) return -ELOOP; - r = dns_question_cname_redirect(q->question, cname, &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)); + } - dns_query_stop(q); + if (r == 0 && k == 0) /* No actual cname happened? */ + return -ELOOP; + + 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; @@ -1150,15 +953,16 @@ int dns_query_process_cname(DnsQuery *q) { if (!IN_SET(q->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NULL)) return DNS_QUERY_NOMATCH; - DNS_ANSWER_FOREACH(rr, q->answer) { + question = dns_query_question_for_protocol(q, q->answer_protocol); - r = dns_question_matches_rr(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + 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(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); + 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) @@ -1219,3 +1023,42 @@ 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); +} |