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_add_soa(DnsAnswer *a, const char *name) {
101 _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *soa = NULL;
103 soa = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SOA, name);
107 soa->soa.mname = strdup(name);
111 soa->soa.rname = strappend("root.", name);
116 soa->soa.refresh = 1;
119 soa->soa.minimum = 1;
121 return dns_answer_add(a, soa);
124 int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) {
131 for (i = 0; i < a->n_rrs; i++) {
132 r = dns_resource_key_match_rr(key, a->rrs[i]);
142 int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) {
149 /* For a SOA record we can never find a matching SOA record */
150 if (key->type == DNS_TYPE_SOA)
153 for (i = 0; i < a->n_rrs; i++) {
155 if (a->rrs[i]->key->class != DNS_CLASS_IN)
158 if (a->rrs[i]->key->type != DNS_TYPE_SOA)
161 if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->rrs[i]->key))) {
170 DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) {
171 _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL;
176 if (a && (!b || b->n_rrs <= 0))
177 return dns_answer_ref(a);
178 if ((!a || a->n_rrs <= 0) && b)
179 return dns_answer_ref(b);
181 ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0));
186 for (i = 0; i < a->n_rrs; i++) {
187 r = dns_answer_add(ret, a->rrs[i]);
194 for (i = 0; i < b->n_rrs; i++) {
195 r = dns_answer_add(ret, b->rrs[i]);
207 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) {
208 DnsResourceRecord **rrs;
209 unsigned i, start, end;
218 /* RFC 4795, Section 2.6 suggests we should order entries
219 * depending on whether the sender is a link-local address. */
221 rrs = newa(DnsResourceRecord*, a->n_rrs);
222 for (i = 0; i < a->n_rrs; i++) {
224 if (a->rrs[i]->key->class == DNS_CLASS_IN &&
225 ((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) ||
226 (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)))
227 /* Order address records that are are not preferred to the end of the array */
228 rrs[end--] = a->rrs[i];
230 /* Order all other records to the beginning of the array */
231 rrs[start++] = a->rrs[i];
234 assert(start == end+1);
235 memcpy(a->rrs, rrs, sizeof(DnsResourceRecord*) * a->n_rrs);