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-rw-r--r--src/resolve/resolved-dns-query.c1109
1 files changed, 0 insertions, 1109 deletions
diff --git a/src/resolve/resolved-dns-query.c b/src/resolve/resolved-dns-query.c
deleted file mode 100644
index ea04e58d61..0000000000
--- a/src/resolve/resolved-dns-query.c
+++ /dev/null
@@ -1,1109 +0,0 @@
-/***
- This file is part of systemd.
-
- Copyright 2014 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include "alloc-util.h"
-#include "dns-domain.h"
-#include "dns-type.h"
-#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)
-
-#define CNAME_MAX 8
-#define QUERIES_MAX 2048
-#define AUXILIARY_QUERIES_MAX 64
-
-static int dns_query_candidate_new(DnsQueryCandidate **ret, DnsQuery *q, DnsScope *s) {
- DnsQueryCandidate *c;
-
- assert(ret);
- assert(q);
- assert(s);
-
- c = new0(DnsQueryCandidate, 1);
- if (!c)
- return -ENOMEM;
-
- c->query = q;
- c->scope = s;
-
- LIST_PREPEND(candidates_by_query, q->candidates, c);
- LIST_PREPEND(candidates_by_scope, s->query_candidates, c);
-
- *ret = c;
- return 0;
-}
-
-static void dns_query_candidate_stop(DnsQueryCandidate *c) {
- DnsTransaction *t;
-
- assert(c);
-
- while ((t = set_steal_first(c->transactions))) {
- set_remove(t->notify_query_candidates, c);
- set_remove(t->notify_query_candidates_done, c);
- dns_transaction_gc(t);
- }
-}
-
-DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c) {
-
- if (!c)
- return NULL;
-
- dns_query_candidate_stop(c);
-
- set_free(c->transactions);
- dns_search_domain_unref(c->search_domain);
-
- if (c->query)
- LIST_REMOVE(candidates_by_query, c->query->candidates, c);
-
- if (c->scope)
- LIST_REMOVE(candidates_by_scope, c->scope->query_candidates, c);
-
- 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;
- else
- next = dns_scope_get_search_domains(c->scope);
-
- for (;;) {
- if (!next) /* We hit the end of the list */
- return 0;
-
- if (!next->route_only)
- break;
-
- /* Skip over route-only domains */
- next = next->domains_next;
- }
-
- dns_search_domain_unref(c->search_domain);
- c->search_domain = dns_search_domain_ref(next);
-
- return 1;
-}
-
-static int dns_query_candidate_add_transaction(DnsQueryCandidate *c, DnsResourceKey *key) {
- DnsTransaction *t;
- int r;
-
- assert(c);
- assert(key);
-
- t = dns_scope_find_transaction(c->scope, key, true);
- if (!t) {
- r = dns_transaction_new(&t, c->scope, key);
- if (r < 0)
- return r;
- } else {
- if (set_contains(c->transactions, t))
- return 0;
- }
-
- r = set_ensure_allocated(&c->transactions, NULL);
- if (r < 0)
- goto gc;
-
- r = set_ensure_allocated(&t->notify_query_candidates, NULL);
- if (r < 0)
- goto gc;
-
- r = set_ensure_allocated(&t->notify_query_candidates_done, NULL);
- if (r < 0)
- goto gc;
-
- r = set_put(t->notify_query_candidates, c);
- if (r < 0)
- goto gc;
-
- r = set_put(c->transactions, t);
- if (r < 0) {
- (void) set_remove(t->notify_query_candidates, c);
- goto gc;
- }
-
- return 1;
-
-gc:
- dns_transaction_gc(t);
- return r;
-}
-
-static int dns_query_candidate_go(DnsQueryCandidate *c) {
- DnsTransaction *t;
- Iterator i;
- int r;
- unsigned n = 0;
-
- assert(c);
-
- /* Start the transactions that are not started yet */
- SET_FOREACH(t, c->transactions, i) {
- if (t->state != DNS_TRANSACTION_NULL)
- continue;
-
- r = dns_transaction_go(t);
- if (r < 0)
- return r;
-
- n++;
- }
-
- /* If there was nothing to start, then let's proceed immediately */
- if (n == 0)
- dns_query_candidate_notify(c);
-
- return 0;
-}
-
-static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) {
- DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
- DnsTransaction *t;
- Iterator i;
-
- assert(c);
-
- if (c->error_code != 0)
- return DNS_TRANSACTION_ERRNO;
-
- SET_FOREACH(t, c->transactions, i) {
-
- switch (t->state) {
-
- case DNS_TRANSACTION_NULL:
- /* If there's a NULL transaction pending, then
- * this means not all transactions where
- * started yet, and we were called from within
- * the stackframe that is supposed to start
- * remaining transactions. In this case,
- * simply claim the candidate is pending. */
-
- case DNS_TRANSACTION_PENDING:
- case DNS_TRANSACTION_VALIDATING:
- /* If there's one transaction currently in
- * VALIDATING state, then this means there's
- * also one in PENDING state, hence we can
- * return PENDING immediately. */
- return DNS_TRANSACTION_PENDING;
-
- case DNS_TRANSACTION_SUCCESS:
- state = t->state;
- break;
-
- default:
- if (state != DNS_TRANSACTION_SUCCESS)
- state = t->state;
-
- break;
- }
- }
-
- return state;
-}
-
-static bool dns_query_candidate_is_routable(DnsQueryCandidate *c, uint16_t type) {
- int family;
-
- assert(c);
-
- /* Checks whether the specified RR type matches an address family that is routable on the link(s) the scope of
- * this candidate belongs to. Specifically, whether there's a routable IPv4 address on it if we query an A RR,
- * or a routable IPv6 address if we query an AAAA RR. */
-
- if (!c->query->suppress_unroutable_family)
- return true;
-
- if (c->scope->protocol != DNS_PROTOCOL_DNS)
- return true;
-
- family = dns_type_to_af(type);
- if (family < 0)
- return true;
-
- if (c->scope->link)
- return link_relevant(c->scope->link, family, false);
- else
- return manager_routable(c->scope->manager, family);
-}
-
-static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) {
- DnsQuestion *question;
- DnsResourceKey *key;
- int n = 0, r;
-
- assert(c);
-
- dns_query_candidate_stop(c);
-
- question = dns_query_question_for_protocol(c->query, c->scope->protocol);
-
- /* Create one transaction per question key */
- DNS_QUESTION_FOREACH(key, question) {
- _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL;
- DnsResourceKey *qkey;
-
- if (!dns_query_candidate_is_routable(c, key->type))
- continue;
-
- if (c->search_domain) {
- r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name);
- if (r < 0)
- goto fail;
-
- qkey = new_key;
- } else
- qkey = key;
-
- if (!dns_scope_good_key(c->scope, qkey))
- continue;
-
- r = dns_query_candidate_add_transaction(c, qkey);
- if (r < 0)
- goto fail;
-
- n++;
- }
-
- return n;
-
-fail:
- dns_query_candidate_stop(c);
- return r;
-}
-
-void dns_query_candidate_notify(DnsQueryCandidate *c) {
- DnsTransactionState state;
- int r;
-
- assert(c);
-
- state = dns_query_candidate_state(c);
-
- if (DNS_TRANSACTION_IS_LIVE(state))
- return;
-
- if (state != DNS_TRANSACTION_SUCCESS && c->search_domain) {
-
- r = dns_query_candidate_next_search_domain(c);
- if (r < 0)
- goto fail;
-
- if (r > 0) {
- /* OK, there's another search domain to try, let's do so. */
-
- r = dns_query_candidate_setup_transactions(c);
- if (r < 0)
- goto fail;
-
- if (r > 0) {
- /* New transactions where queued. Start them and wait */
-
- r = dns_query_candidate_go(c);
- if (r < 0)
- goto fail;
-
- return;
- }
- }
-
- }
-
- dns_query_ready(c->query);
- return;
-
-fail:
- log_warning_errno(r, "Failed to follow search domains: %m");
- c->error_code = r;
- dns_query_ready(c->query);
-}
-
-static void dns_query_stop(DnsQuery *q) {
- DnsQueryCandidate *c;
-
- assert(q);
-
- q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
-
- LIST_FOREACH(candidates_by_query, c, q->candidates)
- dns_query_candidate_stop(c);
-}
-
-static void dns_query_free_candidates(DnsQuery *q) {
- assert(q);
-
- while (q->candidates)
- dns_query_candidate_free(q->candidates);
-}
-
-static void dns_query_reset_answer(DnsQuery *q) {
- assert(q);
-
- q->answer = dns_answer_unref(q->answer);
- q->answer_rcode = 0;
- q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
- q->answer_errno = 0;
- q->answer_authenticated = false;
- q->answer_protocol = _DNS_PROTOCOL_INVALID;
- q->answer_family = AF_UNSPEC;
- q->answer_search_domain = dns_search_domain_unref(q->answer_search_domain);
-}
-
-DnsQuery *dns_query_free(DnsQuery *q) {
- if (!q)
- return NULL;
-
- while (q->auxiliary_queries)
- dns_query_free(q->auxiliary_queries);
-
- if (q->auxiliary_for) {
- assert(q->auxiliary_for->n_auxiliary_queries > 0);
- q->auxiliary_for->n_auxiliary_queries--;
- LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q);
- }
-
- dns_query_free_candidates(q);
-
- dns_question_unref(q->question_idna);
- dns_question_unref(q->question_utf8);
-
- dns_query_reset_answer(q);
-
- sd_bus_message_unref(q->request);
- sd_bus_track_unref(q->bus_track);
-
- free(q->request_address_string);
-
- if (q->manager) {
- LIST_REMOVE(queries, q->manager->dns_queries, q);
- q->manager->n_dns_queries--;
- }
-
- free(q);
-
- return NULL;
-}
-
-int dns_query_new(
- Manager *m,
- DnsQuery **ret,
- DnsQuestion *question_utf8,
- DnsQuestion *question_idna,
- int ifindex, uint64_t flags) {
-
- _cleanup_(dns_query_freep) DnsQuery *q = NULL;
- DnsResourceKey *key;
- bool good = false;
- int r;
- char key_str[DNS_RESOURCE_KEY_STRING_MAX];
-
- assert(m);
-
- if (dns_question_size(question_utf8) > 0) {
- r = dns_question_is_valid_for_query(question_utf8);
- if (r < 0)
- return r;
- if (r == 0)
- return -EINVAL;
-
- good = true;
- }
-
- /* If the IDNA and UTF8 questions are the same, merge their references */
- r = dns_question_is_equal(question_idna, question_utf8);
- if (r < 0)
- return r;
- if (r > 0)
- question_idna = question_utf8;
- else {
- if (dns_question_size(question_idna) > 0) {
- r = dns_question_is_valid_for_query(question_idna);
- if (r < 0)
- return r;
- if (r == 0)
- return -EINVAL;
-
- good = true;
- }
- }
-
- if (!good) /* don't allow empty queries */
- return -EINVAL;
-
- if (m->n_dns_queries >= QUERIES_MAX)
- return -EBUSY;
-
- q = new0(DnsQuery, 1);
- if (!q)
- return -ENOMEM;
-
- q->question_utf8 = dns_question_ref(question_utf8);
- q->question_idna = dns_question_ref(question_idna);
- q->ifindex = ifindex;
- q->flags = flags;
- q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
- q->answer_protocol = _DNS_PROTOCOL_INVALID;
- q->answer_family = AF_UNSPEC;
-
- /* First dump UTF8 question */
- DNS_QUESTION_FOREACH(key, question_utf8)
- log_debug("Looking up RR for %s.",
- dns_resource_key_to_string(key, key_str, sizeof key_str));
-
- /* And then dump the IDNA question, but only what hasn't been dumped already through the UTF8 question. */
- DNS_QUESTION_FOREACH(key, question_idna) {
- r = dns_question_contains(question_utf8, key);
- if (r < 0)
- return r;
- if (r > 0)
- continue;
-
- log_debug("Looking up IDNA RR for %s.",
- dns_resource_key_to_string(key, key_str, sizeof key_str));
- }
-
- LIST_PREPEND(queries, m->dns_queries, q);
- m->n_dns_queries++;
- q->manager = m;
-
- if (ret)
- *ret = q;
- q = NULL;
-
- return 0;
-}
-
-int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for) {
- assert(q);
- assert(auxiliary_for);
-
- /* Ensure that that the query is not auxiliary yet, and
- * nothing else is auxiliary to it either */
- assert(!q->auxiliary_for);
- assert(!q->auxiliary_queries);
-
- /* Ensure that the unit we shall be made auxiliary for isn't
- * auxiliary itself */
- assert(!auxiliary_for->auxiliary_for);
-
- if (auxiliary_for->n_auxiliary_queries >= AUXILIARY_QUERIES_MAX)
- return -EAGAIN;
-
- LIST_PREPEND(auxiliary_queries, auxiliary_for->auxiliary_queries, q);
- q->auxiliary_for = auxiliary_for;
-
- auxiliary_for->n_auxiliary_queries++;
- return 0;
-}
-
-static void dns_query_complete(DnsQuery *q, DnsTransactionState state) {
- assert(q);
- assert(!DNS_TRANSACTION_IS_LIVE(state));
- assert(DNS_TRANSACTION_IS_LIVE(q->state));
-
- /* Note that this call might invalidate the query. Callers
- * should hence not attempt to access the query or transaction
- * after calling this function. */
-
- q->state = state;
-
- dns_query_stop(q);
- if (q->complete)
- q->complete(q);
-}
-
-static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQuery *q = userdata;
-
- assert(s);
- assert(q);
-
- dns_query_complete(q, DNS_TRANSACTION_TIMEOUT);
- return 0;
-}
-
-static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) {
- DnsQueryCandidate *c;
- int r;
-
- assert(q);
- assert(s);
-
- r = dns_query_candidate_new(&c, q, s);
- if (r < 0)
- return r;
-
- /* If this a single-label domain on DNS, we might append a suitable search domain first. */
- if ((q->flags & SD_RESOLVED_NO_SEARCH) == 0) {
- r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question_idna));
- if (r < 0)
- goto fail;
- if (r > 0) {
- /* OK, we need a search domain now. Let's find one for this scope */
-
- r = dns_query_candidate_next_search_domain(c);
- if (r <= 0) /* if there's no search domain, then we won't add any transaction. */
- goto fail;
- }
- }
-
- r = dns_query_candidate_setup_transactions(c);
- if (r < 0)
- goto fail;
-
- return 0;
-
-fail:
- dns_query_candidate_free(c);
- return r;
-}
-
-static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) {
- _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
- int r;
-
- assert(q);
- assert(state);
-
- /* Tries to synthesize localhost RR replies (and others) where appropriate. Note that this is done *after* the
- * the normal lookup finished. The data from the network hence takes precedence over the data we
- * synthesize. (But note that many scopes refuse to resolve certain domain names) */
-
- if (!IN_SET(*state,
- DNS_TRANSACTION_RCODE_FAILURE,
- DNS_TRANSACTION_NO_SERVERS,
- DNS_TRANSACTION_TIMEOUT,
- DNS_TRANSACTION_ATTEMPTS_MAX_REACHED,
- DNS_TRANSACTION_NETWORK_DOWN,
- DNS_TRANSACTION_NOT_FOUND))
- return 0;
-
- r = dns_synthesize_answer(
- q->manager,
- q->question_utf8,
- q->ifindex,
- &answer);
-
- if (r <= 0)
- return r;
-
- dns_query_reset_answer(q);
-
- q->answer = answer;
- answer = NULL;
- q->answer_rcode = DNS_RCODE_SUCCESS;
- q->answer_protocol = dns_synthesize_protocol(q->flags);
- q->answer_family = dns_synthesize_family(q->flags);
- q->answer_authenticated = true;
-
- *state = DNS_TRANSACTION_SUCCESS;
-
- return 1;
-}
-
-static int dns_query_try_etc_hosts(DnsQuery *q) {
- _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
- int r;
-
- assert(q);
-
- /* Looks in /etc/hosts for matching entries. Note that this is done *before* the normal lookup is done. The
- * data from /etc/hosts hence takes precedence over the network. */
-
- r = manager_etc_hosts_lookup(
- q->manager,
- q->question_utf8,
- &answer);
- if (r <= 0)
- return r;
-
- dns_query_reset_answer(q);
-
- q->answer = answer;
- answer = NULL;
- q->answer_rcode = DNS_RCODE_SUCCESS;
- q->answer_protocol = dns_synthesize_protocol(q->flags);
- q->answer_family = dns_synthesize_family(q->flags);
- q->answer_authenticated = true;
-
- return 1;
-}
-
-int dns_query_go(DnsQuery *q) {
- DnsScopeMatch found = DNS_SCOPE_NO;
- DnsScope *s, *first = NULL;
- DnsQueryCandidate *c;
- int r;
-
- assert(q);
-
- if (q->state != DNS_TRANSACTION_NULL)
- return 0;
-
- r = dns_query_try_etc_hosts(q);
- if (r < 0)
- return r;
- if (r > 0) {
- dns_query_complete(q, DNS_TRANSACTION_SUCCESS);
- return 1;
- }
-
- LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
- DnsScopeMatch match;
- const char *name;
-
- name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol));
- if (!name)
- continue;
-
- match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
- if (match < 0)
- return match;
-
- if (match == DNS_SCOPE_NO)
- continue;
-
- found = match;
-
- if (match == DNS_SCOPE_YES) {
- first = s;
- break;
- } else {
- assert(match == DNS_SCOPE_MAYBE);
-
- if (!first)
- first = s;
- }
- }
-
- if (found == DNS_SCOPE_NO) {
- DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
-
- r = dns_query_synthesize_reply(q, &state);
- if (r < 0)
- return r;
-
- dns_query_complete(q, state);
- return 1;
- }
-
- r = dns_query_add_candidate(q, first);
- if (r < 0)
- goto fail;
-
- LIST_FOREACH(scopes, s, first->scopes_next) {
- DnsScopeMatch match;
- const char *name;
-
- name = dns_question_first_name(dns_query_question_for_protocol(q, s->protocol));
- if (!name)
- continue;
-
- match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
- if (match < 0)
- goto fail;
-
- if (match != found)
- continue;
-
- r = dns_query_add_candidate(q, s);
- if (r < 0)
- goto fail;
- }
-
- dns_query_reset_answer(q);
-
- r = sd_event_add_time(
- q->manager->event,
- &q->timeout_event_source,
- clock_boottime_or_monotonic(),
- now(clock_boottime_or_monotonic()) + QUERY_TIMEOUT_USEC, 0,
- on_query_timeout, q);
- if (r < 0)
- goto fail;
-
- (void) sd_event_source_set_description(q->timeout_event_source, "query-timeout");
-
- q->state = DNS_TRANSACTION_PENDING;
- q->block_ready++;
-
- /* Start the transactions */
- LIST_FOREACH(candidates_by_query, c, q->candidates) {
- r = dns_query_candidate_go(c);
- if (r < 0) {
- q->block_ready--;
- goto fail;
- }
- }
-
- q->block_ready--;
- dns_query_ready(q);
-
- return 1;
-
-fail:
- dns_query_stop(q);
- return r;
-}
-
-static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) {
- DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
- bool has_authenticated = false, has_non_authenticated = false;
- DnssecResult dnssec_result_authenticated = _DNSSEC_RESULT_INVALID, dnssec_result_non_authenticated = _DNSSEC_RESULT_INVALID;
- DnsTransaction *t;
- Iterator i;
- int r;
-
- assert(q);
-
- if (!c) {
- r = dns_query_synthesize_reply(q, &state);
- if (r < 0)
- goto fail;
-
- dns_query_complete(q, state);
- return;
- }
-
- if (c->error_code != 0) {
- /* If the candidate had an error condition of its own, start with that. */
- state = DNS_TRANSACTION_ERRNO;
- q->answer = dns_answer_unref(q->answer);
- q->answer_rcode = 0;
- q->answer_dnssec_result = _DNSSEC_RESULT_INVALID;
- q->answer_errno = c->error_code;
- }
-
- SET_FOREACH(t, c->transactions, i) {
-
- switch (t->state) {
-
- case DNS_TRANSACTION_SUCCESS: {
- /* We found a successfully reply, merge it into the answer */
- r = dns_answer_extend(&q->answer, t->answer);
- if (r < 0)
- goto fail;
-
- q->answer_rcode = t->answer_rcode;
- q->answer_errno = 0;
-
- if (t->answer_authenticated) {
- has_authenticated = true;
- dnssec_result_authenticated = t->answer_dnssec_result;
- } else {
- has_non_authenticated = true;
- dnssec_result_non_authenticated = t->answer_dnssec_result;
- }
-
- state = DNS_TRANSACTION_SUCCESS;
- break;
- }
-
- case DNS_TRANSACTION_NULL:
- case DNS_TRANSACTION_PENDING:
- case DNS_TRANSACTION_VALIDATING:
- case DNS_TRANSACTION_ABORTED:
- /* Ignore transactions that didn't complete */
- continue;
-
- default:
- /* Any kind of failure? Store the data away,
- * if there's nothing stored yet. */
-
- if (state == DNS_TRANSACTION_SUCCESS)
- continue;
-
- q->answer = dns_answer_unref(q->answer);
- q->answer_rcode = t->answer_rcode;
- q->answer_dnssec_result = t->answer_dnssec_result;
- q->answer_errno = t->answer_errno;
-
- state = t->state;
- break;
- }
- }
-
- if (state == DNS_TRANSACTION_SUCCESS) {
- q->answer_authenticated = has_authenticated && !has_non_authenticated;
- q->answer_dnssec_result = q->answer_authenticated ? dnssec_result_authenticated : dnssec_result_non_authenticated;
- }
-
- q->answer_protocol = c->scope->protocol;
- q->answer_family = c->scope->family;
-
- dns_search_domain_unref(q->answer_search_domain);
- q->answer_search_domain = dns_search_domain_ref(c->search_domain);
-
- r = dns_query_synthesize_reply(q, &state);
- if (r < 0)
- goto fail;
-
- dns_query_complete(q, state);
- return;
-
-fail:
- q->answer_errno = -r;
- dns_query_complete(q, DNS_TRANSACTION_ERRNO);
-}
-
-void dns_query_ready(DnsQuery *q) {
-
- DnsQueryCandidate *bad = NULL, *c;
- bool pending = false;
-
- assert(q);
- assert(DNS_TRANSACTION_IS_LIVE(q->state));
-
- /* Note that this call might invalidate the query. Callers
- * should hence not attempt to access the query or transaction
- * after calling this function, unless the block_ready
- * counter was explicitly bumped before doing so. */
-
- if (q->block_ready > 0)
- return;
-
- LIST_FOREACH(candidates_by_query, c, q->candidates) {
- DnsTransactionState state;
-
- state = dns_query_candidate_state(c);
- switch (state) {
-
- case DNS_TRANSACTION_SUCCESS:
- /* One of the candidates is successful,
- * let's use it, and copy its data out */
- dns_query_accept(q, c);
- return;
-
- case DNS_TRANSACTION_NULL:
- case DNS_TRANSACTION_PENDING:
- case DNS_TRANSACTION_VALIDATING:
- /* One of the candidates is still going on,
- * let's maybe wait for it */
- pending = true;
- break;
-
- default:
- /* Any kind of failure */
- bad = c;
- break;
- }
- }
-
- if (pending)
- return;
-
- dns_query_accept(q, bad);
-}
-
-static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) {
- _cleanup_(dns_question_unrefp) DnsQuestion *nq_idna = NULL, *nq_utf8 = NULL;
- int r, k;
-
- assert(q);
-
- q->n_cname_redirects++;
- if (q->n_cname_redirects > CNAME_MAX)
- return -ELOOP;
-
- r = dns_question_cname_redirect(q->question_idna, cname, &nq_idna);
- if (r < 0)
- return r;
- else if (r > 0)
- log_debug("Following CNAME/DNAME %s → %s.", dns_question_first_name(q->question_idna), dns_question_first_name(nq_idna));
-
- k = dns_question_is_equal(q->question_idna, q->question_utf8);
- if (k < 0)
- return r;
- if (k > 0) {
- /* Same question? Shortcut new question generation */
- nq_utf8 = dns_question_ref(nq_idna);
- k = r;
- } else {
- k = dns_question_cname_redirect(q->question_utf8, cname, &nq_utf8);
- if (k < 0)
- return k;
- else if (k > 0)
- log_debug("Following UTF8 CNAME/DNAME %s → %s.", dns_question_first_name(q->question_utf8), dns_question_first_name(nq_utf8));
- }
-
- if (r == 0 && k == 0) /* No actual cname happened? */
- return -ELOOP;
-
- if (q->answer_protocol == DNS_PROTOCOL_DNS) {
- /* Don't permit CNAME redirects from unicast DNS to LLMNR or MulticastDNS, so that global resources
- * cannot invade the local namespace. The opposite way we permit: local names may redirect to global
- * ones. */
-
- q->flags &= ~(SD_RESOLVED_LLMNR|SD_RESOLVED_MDNS); /* mask away the local protocols */
- }
-
- /* Turn off searching for the new name */
- q->flags |= SD_RESOLVED_NO_SEARCH;
-
- dns_question_unref(q->question_idna);
- q->question_idna = nq_idna;
- nq_idna = NULL;
-
- dns_question_unref(q->question_utf8);
- q->question_utf8 = nq_utf8;
- nq_utf8 = NULL;
-
- dns_query_free_candidates(q);
- dns_query_reset_answer(q);
-
- q->state = DNS_TRANSACTION_NULL;
-
- return 0;
-}
-
-int dns_query_process_cname(DnsQuery *q) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL;
- DnsQuestion *question;
- DnsResourceRecord *rr;
- int r;
-
- assert(q);
-
- if (!IN_SET(q->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NULL))
- return DNS_QUERY_NOMATCH;
-
- question = dns_query_question_for_protocol(q, q->answer_protocol);
-
- DNS_ANSWER_FOREACH(rr, q->answer) {
- r = dns_question_matches_rr(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
- if (r < 0)
- return r;
- if (r > 0)
- return DNS_QUERY_MATCH; /* The answer matches directly, no need to follow cnames */
-
- r = dns_question_matches_cname_or_dname(question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
- if (r < 0)
- return r;
- if (r > 0 && !cname)
- cname = dns_resource_record_ref(rr);
- }
-
- if (!cname)
- return DNS_QUERY_NOMATCH; /* No match and no cname to follow */
-
- if (q->flags & SD_RESOLVED_NO_CNAME)
- return -ELOOP;
-
- /* OK, let's actually follow the CNAME */
- r = dns_query_cname_redirect(q, cname);
- if (r < 0)
- return r;
-
- /* Let's see if the answer can already answer the new
- * redirected question */
- r = dns_query_process_cname(q);
- if (r != DNS_QUERY_NOMATCH)
- return r;
-
- /* OK, it cannot, let's begin with the new query */
- r = dns_query_go(q);
- if (r < 0)
- return r;
-
- return DNS_QUERY_RESTARTED; /* We restarted the query for a new cname */
-}
-
-static int on_bus_track(sd_bus_track *t, void *userdata) {
- DnsQuery *q = userdata;
-
- assert(t);
- assert(q);
-
- log_debug("Client of active query vanished, aborting query.");
- dns_query_complete(q, DNS_TRANSACTION_ABORTED);
- return 0;
-}
-
-int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) {
- int r;
-
- assert(q);
- assert(m);
-
- if (!q->bus_track) {
- r = sd_bus_track_new(sd_bus_message_get_bus(m), &q->bus_track, on_bus_track, q);
- if (r < 0)
- return r;
- }
-
- r = sd_bus_track_add_sender(q->bus_track, m);
- if (r < 0)
- return r;
-
- return 0;
-}
-
-DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol) {
- assert(q);
-
- switch (protocol) {
-
- case DNS_PROTOCOL_DNS:
- return q->question_idna;
-
- case DNS_PROTOCOL_MDNS:
- case DNS_PROTOCOL_LLMNR:
- return q->question_utf8;
-
- default:
- return NULL;
- }
-}
-
-const char *dns_query_string(DnsQuery *q) {
- const char *name;
- int r;
-
- /* Returns a somewhat useful human-readable lookup key string for this query */
-
- if (q->request_address_string)
- return q->request_address_string;
-
- if (q->request_address_valid) {
- r = in_addr_to_string(q->request_family, &q->request_address, &q->request_address_string);
- if (r >= 0)
- return q->request_address_string;
- }
-
- name = dns_question_first_name(q->question_utf8);
- if (name)
- return name;
-
- return dns_question_first_name(q->question_idna);
-}