404 lines
10 KiB
C
404 lines
10 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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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 "resolved-dns-question.h"
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DnsQuestion *dns_question_new(unsigned n) {
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DnsQuestion *q;
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assert(n > 0);
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q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n);
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if (!q)
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return NULL;
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q->n_ref = 1;
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q->n_allocated = n;
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return q;
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}
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DnsQuestion *dns_question_ref(DnsQuestion *q) {
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if (!q)
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return NULL;
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assert(q->n_ref > 0);
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q->n_ref++;
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return q;
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}
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DnsQuestion *dns_question_unref(DnsQuestion *q) {
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if (!q)
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return NULL;
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assert(q->n_ref > 0);
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if (q->n_ref == 1) {
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unsigned i;
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for (i = 0; i < q->n_keys; i++)
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dns_resource_key_unref(q->keys[i]);
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free(q);
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} else
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q->n_ref--;
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return NULL;
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}
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int dns_question_add(DnsQuestion *q, DnsResourceKey *key) {
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unsigned i;
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int r;
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assert(key);
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if (!q)
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return -ENOSPC;
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for (i = 0; i < q->n_keys; i++) {
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r = dns_resource_key_equal(q->keys[i], key);
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if (r < 0)
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return r;
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if (r > 0)
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return 0;
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}
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if (q->n_keys >= q->n_allocated)
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return -ENOSPC;
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q->keys[q->n_keys++] = dns_resource_key_ref(key);
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return 0;
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}
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int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
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unsigned i;
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int r;
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assert(rr);
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if (!q)
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return 0;
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for (i = 0; i < q->n_keys; i++) {
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r = dns_resource_key_match_rr(q->keys[i], rr, search_domain);
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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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int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) {
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unsigned i;
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int r;
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assert(rr);
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if (!q)
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return 0;
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for (i = 0; i < q->n_keys; i++) {
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r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain);
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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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int dns_question_is_valid_for_query(DnsQuestion *q) {
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const char *name;
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unsigned i;
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int r;
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if (!q)
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return 0;
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if (q->n_keys <= 0)
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return 0;
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if (q->n_keys > 65535)
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return 0;
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name = DNS_RESOURCE_KEY_NAME(q->keys[0]);
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if (!name)
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return 0;
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/* Check that all keys in this question bear the same name */
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for (i = 1; i < q->n_keys; i++) {
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assert(q->keys[i]);
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r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name);
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if (r <= 0)
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return r;
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}
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return 1;
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}
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int dns_question_contains(DnsQuestion *a, DnsResourceKey *k) {
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unsigned j;
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int r;
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assert(k);
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if (!a)
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return 0;
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for (j = 0; j < a->n_keys; j++) {
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r = dns_resource_key_equal(a->keys[j], k);
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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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int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) {
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unsigned j;
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int r;
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if (!a)
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return !b || b->n_keys == 0;
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if (!b)
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return a->n_keys == 0;
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/* Checks if all keys in a are also contained b, and vice versa */
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for (j = 0; j < a->n_keys; j++) {
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r = dns_question_contains(b, a->keys[j]);
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if (r <= 0)
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return r;
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}
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for (j = 0; j < b->n_keys; j++) {
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r = dns_question_contains(a, b->keys[j]);
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if (r <= 0)
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return r;
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}
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return 1;
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}
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int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) {
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_cleanup_(dns_question_unrefp) DnsQuestion *n = NULL;
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bool same = true;
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unsigned i;
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int r;
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assert(cname);
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assert(ret);
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assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME));
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if (!q) {
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n = dns_question_new(0);
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if (!n)
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return -ENOMEM;
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*ret = n;
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n = 0;
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return 0;
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}
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for (i = 0; i < q->n_keys; i++) {
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_cleanup_free_ char *destination = NULL;
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const char *d;
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if (cname->key->type == DNS_TYPE_CNAME)
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d = cname->cname.name;
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else {
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r = dns_name_change_suffix(DNS_RESOURCE_KEY_NAME(q->keys[i]), DNS_RESOURCE_KEY_NAME(cname->key), cname->dname.name, &destination);
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if (r < 0)
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return r;
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if (r == 0)
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continue;
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d = destination;
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}
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r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), d);
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if (r < 0)
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return r;
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if (r == 0) {
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same = false;
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break;
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}
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}
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if (same) {
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/* Shortcut, the names are already right */
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*ret = dns_question_ref(q);
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return 0;
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}
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n = dns_question_new(q->n_keys);
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if (!n)
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return -ENOMEM;
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/* Create a new question, and patch in the new name */
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for (i = 0; i < q->n_keys; i++) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL;
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k = dns_resource_key_new_redirect(q->keys[i], cname);
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if (!k)
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return -ENOMEM;
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r = dns_question_add(n, k);
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if (r < 0)
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return r;
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}
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*ret = n;
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n = NULL;
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return 1;
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}
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const char *dns_question_first_name(DnsQuestion *q) {
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if (!q)
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return NULL;
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if (q->n_keys < 1)
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return NULL;
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return DNS_RESOURCE_KEY_NAME(q->keys[0]);
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}
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int dns_question_new_address(DnsQuestion **ret, int family, const char *name) {
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_cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
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int r;
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assert(ret);
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assert(name);
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if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
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return -EAFNOSUPPORT;
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q = dns_question_new(family == AF_UNSPEC ? 2 : 1);
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if (!q)
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return -ENOMEM;
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if (family != AF_INET6) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
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key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name);
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if (!key)
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return -ENOMEM;
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r = dns_question_add(q, key);
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if (r < 0)
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return r;
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}
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if (family != AF_INET) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
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key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name);
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if (!key)
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return -ENOMEM;
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r = dns_question_add(q, key);
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if (r < 0)
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return r;
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}
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*ret = q;
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q = NULL;
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return 0;
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}
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int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
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_cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
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_cleanup_free_ char *reverse = NULL;
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int r;
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assert(ret);
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assert(a);
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if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
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return -EAFNOSUPPORT;
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r = dns_name_reverse(family, a, &reverse);
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if (r < 0)
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return r;
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q = dns_question_new(1);
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if (!q)
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return -ENOMEM;
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key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse);
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if (!key)
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return -ENOMEM;
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reverse = NULL;
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r = dns_question_add(q, key);
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if (r < 0)
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return r;
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*ret = q;
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q = NULL;
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return 0;
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}
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int dns_question_new_service(DnsQuestion **ret, const char *name, bool with_txt) {
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_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
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_cleanup_(dns_question_unrefp) DnsQuestion *q = NULL;
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int r;
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assert(ret);
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assert(name);
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q = dns_question_new(1 + with_txt);
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if (!q)
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return -ENOMEM;
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key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name);
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if (!key)
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return -ENOMEM;
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r = dns_question_add(q, key);
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if (r < 0)
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return r;
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if (with_txt) {
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dns_resource_key_unref(key);
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key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name);
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if (!key)
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return -ENOMEM;
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r = dns_question_add(q, key);
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if (r < 0)
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return r;
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}
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*ret = q;
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q = NULL;
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return 0;
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}
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