d38d5ca65b
Otherwise if we have an A lookup that failed DNSSEC validation, but an AAAA lookup that succeeded, we might end up using the A data, but we really should not.
1224 lines
37 KiB
C
1224 lines
37 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2014 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
|
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
|
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WITHOUT ANY WARRANTY; without even the implied warranty of
|
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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|
Lesser General Public License for more details.
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|
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include "alloc-util.h"
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#include "dns-domain.h"
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#include "hostname-util.h"
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#include "local-addresses.h"
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#include "resolved-dns-query.h"
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|
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/* How long to wait for the query in total */
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#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC)
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|
|
#define CNAME_MAX 8
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#define QUERIES_MAX 2048
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#define AUXILIARY_QUERIES_MAX 64
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|
|
static int dns_query_candidate_new(DnsQueryCandidate **ret, DnsQuery *q, DnsScope *s) {
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DnsQueryCandidate *c;
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|
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assert(ret);
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assert(q);
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assert(s);
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|
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c = new0(DnsQueryCandidate, 1);
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if (!c)
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return -ENOMEM;
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c->query = q;
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c->scope = s;
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LIST_PREPEND(candidates_by_query, q->candidates, c);
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LIST_PREPEND(candidates_by_scope, s->query_candidates, c);
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|
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*ret = c;
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return 0;
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}
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|
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static void dns_query_candidate_stop(DnsQueryCandidate *c) {
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DnsTransaction *t;
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|
|
assert(c);
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|
|
while ((t = set_steal_first(c->transactions))) {
|
|
set_remove(t->notify_query_candidates, c);
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|
dns_transaction_gc(t);
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|
}
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|
}
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|
|
|
DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c) {
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|
|
if (!c)
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return NULL;
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|
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dns_query_candidate_stop(c);
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|
|
set_free(c->transactions);
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dns_search_domain_unref(c->search_domain);
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|
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if (c->query)
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LIST_REMOVE(candidates_by_query, c->query->candidates, c);
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|
|
if (c->scope)
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LIST_REMOVE(candidates_by_scope, c->scope->query_candidates, c);
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|
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free(c);
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return NULL;
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}
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|
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static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) {
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DnsSearchDomain *next = NULL;
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|
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assert(c);
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|
|
if (c->search_domain && c->search_domain->linked) {
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next = c->search_domain->domains_next;
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|
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if (!next) /* We hit the end of the list */
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return 0;
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|
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} else {
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next = dns_scope_get_search_domains(c->scope);
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|
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if (!next) /* OK, there's nothing. */
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return 0;
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}
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dns_search_domain_unref(c->search_domain);
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c->search_domain = dns_search_domain_ref(next);
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|
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return 1;
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|
}
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|
|
static int dns_query_candidate_add_transaction(DnsQueryCandidate *c, DnsResourceKey *key) {
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|
DnsTransaction *t;
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int r;
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|
|
assert(c);
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|
assert(key);
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t = dns_scope_find_transaction(c->scope, key, true);
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if (!t) {
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r = dns_transaction_new(&t, c->scope, key);
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if (r < 0)
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return r;
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} else {
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if (set_contains(c->transactions, t))
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return 0;
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}
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r = set_ensure_allocated(&c->transactions, NULL);
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if (r < 0)
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goto gc;
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r = set_ensure_allocated(&t->notify_query_candidates, NULL);
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if (r < 0)
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goto gc;
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r = set_put(t->notify_query_candidates, c);
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if (r < 0)
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goto gc;
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r = set_put(c->transactions, t);
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|
if (r < 0) {
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|
(void) set_remove(t->notify_query_candidates, c);
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goto gc;
|
|
}
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|
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|
return 1;
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|
|
|
gc:
|
|
dns_transaction_gc(t);
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|
return r;
|
|
}
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|
|
|
static int dns_query_candidate_go(DnsQueryCandidate *c) {
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|
DnsTransaction *t;
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|
Iterator i;
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|
int r;
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|
|
assert(c);
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|
|
|
/* Start the transactions that are not started yet */
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|
SET_FOREACH(t, c->transactions, i) {
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if (t->state != DNS_TRANSACTION_NULL)
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|
continue;
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|
|
|
r = dns_transaction_go(t);
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|
if (r < 0)
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|
return r;
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|
}
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|
|
|
return 0;
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|
}
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|
|
static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) {
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|
DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
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|
DnsTransaction *t;
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|
Iterator i;
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|
|
assert(c);
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|
|
|
if (c->error_code != 0)
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return DNS_TRANSACTION_RESOURCES;
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SET_FOREACH(t, c->transactions, i) {
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|
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switch (t->state) {
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|
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case DNS_TRANSACTION_NULL:
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|
/* If there's a NULL transaction pending, then
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* this means not all transactions where
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|
* started yet, and we were called from within
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* the stackframe that is supposed to start
|
|
* remaining transactions. In this case,
|
|
* simply claim the candidate is pending. */
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|
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case DNS_TRANSACTION_PENDING:
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case DNS_TRANSACTION_VALIDATING:
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|
/* If there's one transaction currently in
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|
* VALIDATING state, then this means there's
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|
* also one in PENDING state, hence we can
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* return PENDING immediately. */
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return DNS_TRANSACTION_PENDING;
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|
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case DNS_TRANSACTION_SUCCESS:
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state = t->state;
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break;
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default:
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if (state != DNS_TRANSACTION_SUCCESS)
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state = t->state;
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break;
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}
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}
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return state;
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|
}
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|
static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) {
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|
DnsResourceKey *key;
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int n = 0, r;
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assert(c);
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dns_query_candidate_stop(c);
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|
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/* Create one transaction per question key */
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DNS_QUESTION_FOREACH(key, c->query->question) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL;
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if (c->search_domain) {
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r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name);
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|
if (r < 0)
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goto fail;
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}
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r = dns_query_candidate_add_transaction(c, new_key ?: key);
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if (r < 0)
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goto fail;
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n++;
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|
}
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return n;
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fail:
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dns_query_candidate_stop(c);
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return r;
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}
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|
|
void dns_query_candidate_notify(DnsQueryCandidate *c) {
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DnsTransactionState state;
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int r;
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assert(c);
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|
state = dns_query_candidate_state(c);
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|
|
if (DNS_TRANSACTION_IS_LIVE(state))
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return;
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if (state != DNS_TRANSACTION_SUCCESS && c->search_domain) {
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r = dns_query_candidate_next_search_domain(c);
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if (r < 0)
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goto fail;
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if (r > 0) {
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/* OK, there's another search domain to try, let's do so. */
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r = dns_query_candidate_setup_transactions(c);
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if (r < 0)
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goto fail;
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if (r > 0) {
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/* New transactions where queued. Start them and wait */
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r = dns_query_candidate_go(c);
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if (r < 0)
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goto fail;
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return;
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|
}
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|
}
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|
|
|
}
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|
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dns_query_ready(c->query);
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|
return;
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|
|
|
fail:
|
|
log_warning_errno(r, "Failed to follow search domains: %m");
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|
c->error_code = r;
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|
dns_query_ready(c->query);
|
|
}
|
|
|
|
static void dns_query_stop(DnsQuery *q) {
|
|
DnsQueryCandidate *c;
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|
|
|
assert(q);
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|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
while (q->candidates)
|
|
dns_query_candidate_free(q->candidates);
|
|
|
|
dns_question_unref(q->question);
|
|
dns_answer_unref(q->answer);
|
|
dns_search_domain_unref(q->answer_search_domain);
|
|
|
|
sd_bus_message_unref(q->request);
|
|
sd_bus_track_unref(q->bus_track);
|
|
|
|
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, int ifindex, uint64_t flags) {
|
|
_cleanup_(dns_query_freep) DnsQuery *q = NULL;
|
|
unsigned i;
|
|
int r;
|
|
|
|
assert(m);
|
|
assert(question);
|
|
|
|
r = dns_question_is_valid_for_query(question);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (m->n_dns_queries >= QUERIES_MAX)
|
|
return -EBUSY;
|
|
|
|
q = new0(DnsQuery, 1);
|
|
if (!q)
|
|
return -ENOMEM;
|
|
|
|
q->question = dns_question_ref(question);
|
|
q->ifindex = ifindex;
|
|
q->flags = flags;
|
|
q->answer_family = AF_UNSPEC;
|
|
q->answer_protocol = _DNS_PROTOCOL_INVALID;
|
|
|
|
for (i = 0; i < question->n_keys; i++) {
|
|
_cleanup_free_ char *p;
|
|
|
|
r = dns_resource_key_to_string(question->keys[i], &p);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
log_debug("Looking up RR for %s", p);
|
|
}
|
|
|
|
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));
|
|
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 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 */
|
|
|
|
if (!IN_SET(*state,
|
|
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++) {
|
|
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 = synthesize_localhost_rr(q, q->question->keys[i], &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);
|
|
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);
|
|
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);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
|
|
|
|
} else if (dns_name_address(name, &af, &address) > 0) {
|
|
|
|
r = synthesize_system_hostname_ptr(q, af, &address, &answer);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m");
|
|
|
|
r = synthesize_gateway_ptr(q, af, &address, &answer);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m");
|
|
}
|
|
}
|
|
|
|
if (!answer)
|
|
return 0;
|
|
|
|
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;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int dns_query_go(DnsQuery *q) {
|
|
DnsScopeMatch found = DNS_SCOPE_NO;
|
|
DnsScope *s, *first = NULL;
|
|
DnsQueryCandidate *c;
|
|
const char *name;
|
|
int r;
|
|
|
|
assert(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);
|
|
|
|
LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
|
|
DnsScopeMatch match;
|
|
|
|
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;
|
|
|
|
dns_query_synthesize_reply(q, &state);
|
|
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;
|
|
|
|
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;
|
|
}
|
|
|
|
q->answer = dns_answer_unref(q->answer);
|
|
q->answer_rcode = 0;
|
|
q->answer_family = AF_UNSPEC;
|
|
q->answer_protocol = _DNS_PROTOCOL_INVALID;
|
|
|
|
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;
|
|
|
|
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) {
|
|
dns_query_synthesize_reply(q, &state);
|
|
dns_query_complete(q, state);
|
|
return;
|
|
}
|
|
|
|
SET_FOREACH(t, c->transactions, i) {
|
|
|
|
switch (t->state) {
|
|
|
|
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;
|
|
}
|
|
|
|
q->answer_rcode = t->answer_rcode;
|
|
|
|
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;
|
|
|
|
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);
|
|
|
|
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;
|
|
|
|
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 = NULL;
|
|
int r;
|
|
|
|
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);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
dns_question_unref(q->question);
|
|
q->question = nq;
|
|
nq = NULL;
|
|
|
|
dns_query_stop(q);
|
|
q->state = DNS_TRANSACTION_NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dns_query_process_cname(DnsQuery *q) {
|
|
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL;
|
|
DnsResourceRecord *rr;
|
|
int r;
|
|
|
|
assert(q);
|
|
|
|
if (q->state != DNS_TRANSACTION_SUCCESS)
|
|
return 0;
|
|
|
|
DNS_ANSWER_FOREACH(rr, q->answer) {
|
|
|
|
r = dns_question_matches_rr(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain));
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0)
|
|
return 0; /* 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));
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0 && !cname)
|
|
cname = dns_resource_record_ref(rr);
|
|
}
|
|
|
|
if (!cname)
|
|
return 0; /* 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 */
|
|
DNS_ANSWER_FOREACH(rr, q->answer) {
|
|
r = dns_question_matches_rr(q->question, rr, NULL);
|
|
if (r < 0)
|
|
return r;
|
|
if (r > 0)
|
|
return 0; /* It can answer it, yay! */
|
|
}
|
|
|
|
/* OK, it cannot, let's begin with the new query */
|
|
r = dns_query_go(q);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
return 1; /* We return > 0, if 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;
|
|
}
|