1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include "resolved-dns-answer.h"
23 #include "resolved-dns-domain.h"
25 DnsAnswer *dns_answer_new(unsigned n) {
30 a = malloc0(offsetof(DnsAnswer, rrs) + sizeof(DnsResourceRecord*) * n);
40 DnsAnswer *dns_answer_ref(DnsAnswer *a) {
49 DnsAnswer *dns_answer_unref(DnsAnswer *a) {
58 for (i = 0; i < a->n_rrs; i++)
59 dns_resource_record_unref(a->rrs[i]);
68 int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr) {
75 for (i = 0; i < a->n_rrs; i++) {
76 r = dns_resource_record_equal(a->rrs[i], rr);
80 /* Entry already exists, keep the entry with
81 * the higher RR, or the one with TTL 0 */
83 if (rr->ttl == 0 || (rr->ttl > a->rrs[i]->ttl && a->rrs[i]->ttl != 0)) {
84 dns_resource_record_ref(rr);
85 dns_resource_record_unref(a->rrs[i]);
93 if (a->n_rrs >= a->n_allocated)
96 a->rrs[a->n_rrs++] = dns_resource_record_ref(rr);
100 int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) {
107 for (i = 0; i < a->n_rrs; i++) {
108 r = dns_resource_key_match_rr(key, a->rrs[i]);
118 int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) {
125 for (i = 0; i < a->n_rrs; i++) {
127 if (a->rrs[i]->key->class != DNS_CLASS_IN)
130 if (a->rrs[i]->key->type != DNS_TYPE_SOA)
133 if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->rrs[i]->key))) {
142 DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) {
143 _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL;
148 if (a && (!b || b->n_rrs <= 0))
149 return dns_answer_ref(a);
150 if ((!a || a->n_rrs <= 0) && b)
151 return dns_answer_ref(b);
153 ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0));
158 for (i = 0; i < a->n_rrs; i++) {
159 r = dns_answer_add(ret, a->rrs[i]);
166 for (i = 0; i < b->n_rrs; i++) {
167 r = dns_answer_add(ret, b->rrs[i]);
179 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) {
180 DnsResourceRecord **rrs;
181 unsigned i, start, end;
190 /* RFC 4795, Section 2.6 suggests we should order entries
191 * depending on whether the sender is a link-local address. */
193 rrs = newa(DnsResourceRecord*, a->n_rrs);
194 for (i = 0; i < a->n_rrs; i++) {
196 if (a->rrs[i]->key->class == DNS_CLASS_IN &&
197 ((a->rrs[i]->key->type == DNS_TYPE_A && in_addr_is_link_local(AF_INET, (union in_addr_union*) &a->rrs[i]->a.in_addr) != prefer_link_local) ||
198 (a->rrs[i]->key->type == DNS_TYPE_AAAA && in_addr_is_link_local(AF_INET6, (union in_addr_union*) &a->rrs[i]->aaaa.in6_addr) != prefer_link_local)))
199 /* Order address records that are are not preferred to the end of the array */
200 rrs[end--] = a->rrs[i];
202 /* Order all other records to the beginning of the array */
203 rrs[start++] = a->rrs[i];
206 assert(start == end+1);
207 memcpy(a->rrs, rrs, sizeof(DnsResourceRecord*) * a->n_rrs);