]>
Commit | Line | Data |
---|---|---|
faa133f3 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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/>. | |
20 | ***/ | |
21 | ||
22 | #include "resolved-dns-answer.h" | |
7e8e0422 | 23 | #include "resolved-dns-domain.h" |
faa133f3 LP |
24 | |
25 | DnsAnswer *dns_answer_new(unsigned n) { | |
26 | DnsAnswer *a; | |
27 | ||
28 | assert(n > 0); | |
29 | ||
30 | a = malloc0(offsetof(DnsAnswer, rrs) + sizeof(DnsResourceRecord*) * n); | |
31 | if (!a) | |
32 | return NULL; | |
33 | ||
34 | a->n_ref = 1; | |
35 | a->n_allocated = n; | |
36 | ||
37 | return a; | |
38 | } | |
39 | ||
40 | DnsAnswer *dns_answer_ref(DnsAnswer *a) { | |
41 | if (!a) | |
42 | return NULL; | |
43 | ||
44 | assert(a->n_ref > 0); | |
45 | a->n_ref++; | |
46 | return a; | |
47 | } | |
48 | ||
49 | DnsAnswer *dns_answer_unref(DnsAnswer *a) { | |
50 | if (!a) | |
51 | return NULL; | |
52 | ||
53 | assert(a->n_ref > 0); | |
54 | ||
55 | if (a->n_ref == 1) { | |
56 | unsigned i; | |
57 | ||
58 | for (i = 0; i < a->n_rrs; i++) | |
59 | dns_resource_record_unref(a->rrs[i]); | |
60 | ||
61 | free(a); | |
62 | } else | |
63 | a->n_ref--; | |
64 | ||
65 | return NULL; | |
66 | } | |
67 | ||
68 | int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr) { | |
7e8e0422 LP |
69 | unsigned i; |
70 | int r; | |
71 | ||
faa133f3 LP |
72 | assert(a); |
73 | assert(rr); | |
74 | ||
7e8e0422 LP |
75 | for (i = 0; i < a->n_rrs; i++) { |
76 | r = dns_resource_record_equal(a->rrs[i], rr); | |
77 | if (r < 0) | |
78 | return r; | |
79 | if (r > 0) { | |
80 | /* Entry already exists, keep the entry with | |
81 | * the higher RR, or the one with TTL 0 */ | |
82 | ||
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]); | |
86 | a->rrs[i] = rr; | |
87 | } | |
88 | ||
89 | return 0; | |
90 | } | |
91 | } | |
92 | ||
faa133f3 LP |
93 | if (a->n_rrs >= a->n_allocated) |
94 | return -ENOSPC; | |
95 | ||
96 | a->rrs[a->n_rrs++] = dns_resource_record_ref(rr); | |
7e8e0422 LP |
97 | return 1; |
98 | } | |
99 | ||
57f5ad31 | 100 | int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl) { |
8bf52d3d LP |
101 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *soa = NULL; |
102 | ||
103 | soa = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_SOA, name); | |
104 | if (!soa) | |
105 | return -ENOMEM; | |
106 | ||
57f5ad31 LP |
107 | soa->ttl = ttl; |
108 | ||
8bf52d3d LP |
109 | soa->soa.mname = strdup(name); |
110 | if (!soa->soa.mname) | |
111 | return -ENOMEM; | |
112 | ||
113 | soa->soa.rname = strappend("root.", name); | |
114 | if (!soa->soa.rname) | |
115 | return -ENOMEM; | |
116 | ||
117 | soa->soa.serial = 1; | |
118 | soa->soa.refresh = 1; | |
119 | soa->soa.retry = 1; | |
120 | soa->soa.expire = 1; | |
57f5ad31 | 121 | soa->soa.minimum = ttl; |
8bf52d3d LP |
122 | |
123 | return dns_answer_add(a, soa); | |
124 | } | |
125 | ||
7e8e0422 LP |
126 | int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { |
127 | unsigned i; | |
128 | int r; | |
129 | ||
130 | assert(a); | |
131 | assert(key); | |
132 | ||
133 | for (i = 0; i < a->n_rrs; i++) { | |
134 | r = dns_resource_key_match_rr(key, a->rrs[i]); | |
135 | if (r < 0) | |
136 | return r; | |
137 | if (r > 0) | |
138 | return 1; | |
139 | } | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) { | |
145 | unsigned i; | |
146 | ||
147 | assert(a); | |
148 | assert(key); | |
149 | assert(ret); | |
150 | ||
0f05c387 LP |
151 | /* For a SOA record we can never find a matching SOA record */ |
152 | if (key->type == DNS_TYPE_SOA) | |
153 | return 0; | |
154 | ||
7e8e0422 LP |
155 | for (i = 0; i < a->n_rrs; i++) { |
156 | ||
157 | if (a->rrs[i]->key->class != DNS_CLASS_IN) | |
158 | continue; | |
159 | ||
160 | if (a->rrs[i]->key->type != DNS_TYPE_SOA) | |
161 | continue; | |
162 | ||
163 | if (dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(a->rrs[i]->key))) { | |
164 | *ret = a->rrs[i]; | |
165 | return 1; | |
166 | } | |
167 | } | |
168 | ||
faa133f3 LP |
169 | return 0; |
170 | } | |
934e9b10 LP |
171 | |
172 | DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) { | |
173 | _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL; | |
174 | DnsAnswer *k; | |
175 | unsigned i; | |
176 | int r; | |
177 | ||
178 | if (a && (!b || b->n_rrs <= 0)) | |
179 | return dns_answer_ref(a); | |
180 | if ((!a || a->n_rrs <= 0) && b) | |
181 | return dns_answer_ref(b); | |
182 | ||
183 | ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0)); | |
184 | if (!ret) | |
185 | return NULL; | |
186 | ||
187 | if (a) { | |
188 | for (i = 0; i < a->n_rrs; i++) { | |
189 | r = dns_answer_add(ret, a->rrs[i]); | |
190 | if (r < 0) | |
191 | return NULL; | |
192 | } | |
193 | } | |
194 | ||
195 | if (b) { | |
196 | for (i = 0; i < b->n_rrs; i++) { | |
197 | r = dns_answer_add(ret, b->rrs[i]); | |
198 | if (r < 0) | |
199 | return NULL; | |
200 | } | |
201 | } | |
202 | ||
203 | k = ret; | |
204 | ret = NULL; | |
205 | ||
206 | return k; | |
207 | } | |
af93291c LP |
208 | |
209 | void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) { | |
210 | DnsResourceRecord **rrs; | |
211 | unsigned i, start, end; | |
212 | assert(a); | |
213 | ||
214 | if (a->n_rrs <= 1) | |
215 | return; | |
216 | ||
217 | start = 0; | |
218 | end = a->n_rrs-1; | |
219 | ||
220 | /* RFC 4795, Section 2.6 suggests we should order entries | |
221 | * depending on whether the sender is a link-local address. */ | |
222 | ||
223 | rrs = newa(DnsResourceRecord*, a->n_rrs); | |
224 | for (i = 0; i < a->n_rrs; i++) { | |
225 | ||
226 | if (a->rrs[i]->key->class == DNS_CLASS_IN && | |
227 | ((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) || | |
228 | (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))) | |
229 | /* Order address records that are are not preferred to the end of the array */ | |
230 | rrs[end--] = a->rrs[i]; | |
231 | else | |
232 | /* Order all other records to the beginning of the array */ | |
233 | rrs[start++] = a->rrs[i]; | |
234 | } | |
235 | ||
236 | assert(start == end+1); | |
237 | memcpy(a->rrs, rrs, sizeof(DnsResourceRecord*) * a->n_rrs); | |
238 | } |