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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
faa133f3 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2014 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
b5efdb8a | 21 | #include "alloc-util.h" |
4ad7f276 | 22 | #include "dns-domain.h" |
0f7091e6 | 23 | #include "dns-type.h" |
b5efdb8a | 24 | #include "resolved-dns-question.h" |
faa133f3 LP |
25 | |
26 | DnsQuestion *dns_question_new(unsigned n) { | |
27 | DnsQuestion *q; | |
28 | ||
29 | assert(n > 0); | |
30 | ||
31 | q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n); | |
32 | if (!q) | |
33 | return NULL; | |
34 | ||
35 | q->n_ref = 1; | |
36 | q->n_allocated = n; | |
37 | ||
38 | return q; | |
39 | } | |
40 | ||
41 | DnsQuestion *dns_question_ref(DnsQuestion *q) { | |
42 | if (!q) | |
43 | return NULL; | |
44 | ||
45 | assert(q->n_ref > 0); | |
46 | q->n_ref++; | |
47 | return q; | |
48 | } | |
49 | ||
50 | DnsQuestion *dns_question_unref(DnsQuestion *q) { | |
51 | if (!q) | |
52 | return NULL; | |
53 | ||
54 | assert(q->n_ref > 0); | |
55 | ||
56 | if (q->n_ref == 1) { | |
57 | unsigned i; | |
58 | ||
59 | for (i = 0; i < q->n_keys; i++) | |
60 | dns_resource_key_unref(q->keys[i]); | |
61 | free(q); | |
62 | } else | |
63 | q->n_ref--; | |
64 | ||
65 | return NULL; | |
66 | } | |
67 | ||
68 | int dns_question_add(DnsQuestion *q, DnsResourceKey *key) { | |
7e8e0422 LP |
69 | unsigned i; |
70 | int r; | |
71 | ||
faa133f3 LP |
72 | assert(key); |
73 | ||
8013e860 LP |
74 | if (!q) |
75 | return -ENOSPC; | |
76 | ||
7e8e0422 LP |
77 | for (i = 0; i < q->n_keys; i++) { |
78 | r = dns_resource_key_equal(q->keys[i], key); | |
79 | if (r < 0) | |
80 | return r; | |
81 | if (r > 0) | |
82 | return 0; | |
83 | } | |
84 | ||
faa133f3 LP |
85 | if (q->n_keys >= q->n_allocated) |
86 | return -ENOSPC; | |
87 | ||
88 | q->keys[q->n_keys++] = dns_resource_key_ref(key); | |
89 | return 0; | |
90 | } | |
91 | ||
801ad6a6 | 92 | int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
faa133f3 LP |
93 | unsigned i; |
94 | int r; | |
95 | ||
faa133f3 LP |
96 | assert(rr); |
97 | ||
8013e860 LP |
98 | if (!q) |
99 | return 0; | |
100 | ||
faa133f3 | 101 | for (i = 0; i < q->n_keys; i++) { |
801ad6a6 | 102 | r = dns_resource_key_match_rr(q->keys[i], rr, search_domain); |
faa133f3 LP |
103 | if (r != 0) |
104 | return r; | |
105 | } | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
542e0c84 | 110 | int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
faa133f3 LP |
111 | unsigned i; |
112 | int r; | |
113 | ||
faa133f3 LP |
114 | assert(rr); |
115 | ||
8013e860 LP |
116 | if (!q) |
117 | return 0; | |
118 | ||
542e0c84 LP |
119 | if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)) |
120 | return 0; | |
121 | ||
faa133f3 | 122 | for (i = 0; i < q->n_keys; i++) { |
542e0c84 LP |
123 | /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */ |
124 | if (!dns_type_may_redirect(q->keys[i]->type)) | |
125 | return 0; | |
126 | ||
5d27351f | 127 | r = dns_resource_key_match_cname_or_dname(q->keys[i], rr->key, search_domain); |
faa133f3 LP |
128 | if (r != 0) |
129 | return r; | |
130 | } | |
131 | ||
34b9656f | 132 | return 0; |
faa133f3 LP |
133 | } |
134 | ||
703e4f5e | 135 | int dns_question_is_valid_for_query(DnsQuestion *q) { |
faa133f3 LP |
136 | const char *name; |
137 | unsigned i; | |
138 | int r; | |
139 | ||
8013e860 LP |
140 | if (!q) |
141 | return 0; | |
faa133f3 LP |
142 | |
143 | if (q->n_keys <= 0) | |
144 | return 0; | |
145 | ||
146 | if (q->n_keys > 65535) | |
147 | return 0; | |
148 | ||
1c02e7ba | 149 | name = dns_resource_key_name(q->keys[0]); |
faa133f3 LP |
150 | if (!name) |
151 | return 0; | |
152 | ||
153 | /* Check that all keys in this question bear the same name */ | |
0f7091e6 | 154 | for (i = 0; i < q->n_keys; i++) { |
34b9656f LP |
155 | assert(q->keys[i]); |
156 | ||
0f7091e6 | 157 | if (i > 0) { |
1c02e7ba | 158 | r = dns_name_equal(dns_resource_key_name(q->keys[i]), name); |
0f7091e6 LP |
159 | if (r <= 0) |
160 | return r; | |
161 | } | |
162 | ||
163 | if (!dns_type_is_valid_query(q->keys[i]->type)) | |
164 | return 0; | |
faa133f3 LP |
165 | } |
166 | ||
167 | return 1; | |
168 | } | |
169 | ||
6a21960c | 170 | int dns_question_contains(DnsQuestion *a, const DnsResourceKey *k) { |
1086182d LP |
171 | unsigned j; |
172 | int r; | |
173 | ||
1086182d LP |
174 | assert(k); |
175 | ||
8013e860 LP |
176 | if (!a) |
177 | return 0; | |
178 | ||
1086182d LP |
179 | for (j = 0; j < a->n_keys; j++) { |
180 | r = dns_resource_key_equal(a->keys[j], k); | |
181 | if (r != 0) | |
182 | return r; | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { | |
189 | unsigned j; | |
190 | int r; | |
191 | ||
b6800689 LP |
192 | if (a == b) |
193 | return 1; | |
194 | ||
8013e860 LP |
195 | if (!a) |
196 | return !b || b->n_keys == 0; | |
197 | if (!b) | |
198 | return a->n_keys == 0; | |
1086182d LP |
199 | |
200 | /* Checks if all keys in a are also contained b, and vice versa */ | |
201 | ||
202 | for (j = 0; j < a->n_keys; j++) { | |
203 | r = dns_question_contains(b, a->keys[j]); | |
204 | if (r <= 0) | |
205 | return r; | |
206 | } | |
207 | ||
208 | for (j = 0; j < b->n_keys; j++) { | |
209 | r = dns_question_contains(a, b->keys[j]); | |
210 | if (r <= 0) | |
211 | return r; | |
212 | } | |
213 | ||
214 | return 1; | |
215 | } | |
216 | ||
36d9205d | 217 | int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { |
faa133f3 | 218 | _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; |
23b298bc | 219 | DnsResourceKey *key; |
faa133f3 | 220 | bool same = true; |
faa133f3 LP |
221 | int r; |
222 | ||
36d9205d | 223 | assert(cname); |
faa133f3 | 224 | assert(ret); |
58db254a | 225 | assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); |
faa133f3 | 226 | |
23b298bc LP |
227 | if (dns_question_size(q) <= 0) { |
228 | *ret = NULL; | |
8013e860 LP |
229 | return 0; |
230 | } | |
231 | ||
23b298bc | 232 | DNS_QUESTION_FOREACH(key, q) { |
58db254a LP |
233 | _cleanup_free_ char *destination = NULL; |
234 | const char *d; | |
235 | ||
236 | if (cname->key->type == DNS_TYPE_CNAME) | |
237 | d = cname->cname.name; | |
238 | else { | |
1c02e7ba | 239 | r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination); |
58db254a LP |
240 | if (r < 0) |
241 | return r; | |
242 | if (r == 0) | |
243 | continue; | |
244 | ||
245 | d = destination; | |
246 | } | |
247 | ||
1c02e7ba | 248 | r = dns_name_equal(dns_resource_key_name(key), d); |
faa133f3 LP |
249 | if (r < 0) |
250 | return r; | |
251 | ||
252 | if (r == 0) { | |
253 | same = false; | |
254 | break; | |
255 | } | |
256 | } | |
257 | ||
23b298bc | 258 | /* Fully the same, indicate we didn't do a thing */ |
faa133f3 | 259 | if (same) { |
23b298bc | 260 | *ret = NULL; |
faa133f3 LP |
261 | return 0; |
262 | } | |
263 | ||
264 | n = dns_question_new(q->n_keys); | |
265 | if (!n) | |
266 | return -ENOMEM; | |
267 | ||
268 | /* Create a new question, and patch in the new name */ | |
23b298bc | 269 | DNS_QUESTION_FOREACH(key, q) { |
faa133f3 LP |
270 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; |
271 | ||
23b298bc | 272 | k = dns_resource_key_new_redirect(key, cname); |
faa133f3 LP |
273 | if (!k) |
274 | return -ENOMEM; | |
275 | ||
276 | r = dns_question_add(n, k); | |
277 | if (r < 0) | |
278 | return r; | |
279 | } | |
280 | ||
281 | *ret = n; | |
282 | n = NULL; | |
283 | ||
284 | return 1; | |
285 | } | |
45ec7efb | 286 | |
703e4f5e LP |
287 | const char *dns_question_first_name(DnsQuestion *q) { |
288 | ||
289 | if (!q) | |
290 | return NULL; | |
45ec7efb LP |
291 | |
292 | if (q->n_keys < 1) | |
293 | return NULL; | |
294 | ||
1c02e7ba | 295 | return dns_resource_key_name(q->keys[0]); |
45ec7efb LP |
296 | } |
297 | ||
23b298bc | 298 | int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) { |
45ec7efb | 299 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; |
23b298bc | 300 | _cleanup_free_ char *buf = NULL; |
45ec7efb LP |
301 | int r; |
302 | ||
303 | assert(ret); | |
304 | assert(name); | |
305 | ||
306 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
307 | return -EAFNOSUPPORT; | |
308 | ||
23b298bc LP |
309 | if (convert_idna) { |
310 | r = dns_name_apply_idna(name, &buf); | |
311 | if (r < 0) | |
312 | return r; | |
ad1f3fe6 | 313 | if (r > 0 && !streq(name, buf)) |
87057e24 | 314 | name = buf; |
ad1f3fe6 ZJS |
315 | else |
316 | /* We did not manage to create convert the idna name, or it's | |
317 | * the same as the original name. We assume the caller already | |
318 | * created an uncoverted question, so let's not repeat work | |
319 | * unnecessarily. */ | |
320 | return -EALREADY; | |
23b298bc LP |
321 | } |
322 | ||
45ec7efb LP |
323 | q = dns_question_new(family == AF_UNSPEC ? 2 : 1); |
324 | if (!q) | |
325 | return -ENOMEM; | |
326 | ||
327 | if (family != AF_INET6) { | |
328 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
329 | ||
330 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name); | |
331 | if (!key) | |
332 | return -ENOMEM; | |
333 | ||
334 | r = dns_question_add(q, key); | |
335 | if (r < 0) | |
336 | return r; | |
337 | } | |
338 | ||
339 | if (family != AF_INET) { | |
340 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
341 | ||
342 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name); | |
343 | if (!key) | |
344 | return -ENOMEM; | |
345 | ||
346 | r = dns_question_add(q, key); | |
347 | if (r < 0) | |
348 | return r; | |
349 | } | |
350 | ||
351 | *ret = q; | |
352 | q = NULL; | |
353 | ||
354 | return 0; | |
355 | } | |
356 | ||
357 | int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) { | |
358 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
359 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
360 | _cleanup_free_ char *reverse = NULL; | |
361 | int r; | |
362 | ||
363 | assert(ret); | |
364 | assert(a); | |
365 | ||
366 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
367 | return -EAFNOSUPPORT; | |
368 | ||
369 | r = dns_name_reverse(family, a, &reverse); | |
370 | if (r < 0) | |
371 | return r; | |
372 | ||
373 | q = dns_question_new(1); | |
374 | if (!q) | |
375 | return -ENOMEM; | |
376 | ||
377 | key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse); | |
378 | if (!key) | |
379 | return -ENOMEM; | |
380 | ||
381 | reverse = NULL; | |
382 | ||
383 | r = dns_question_add(q, key); | |
384 | if (r < 0) | |
385 | return r; | |
386 | ||
387 | *ret = q; | |
388 | q = NULL; | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
23b298bc LP |
393 | int dns_question_new_service( |
394 | DnsQuestion **ret, | |
395 | const char *service, | |
396 | const char *type, | |
397 | const char *domain, | |
398 | bool with_txt, | |
399 | bool convert_idna) { | |
400 | ||
45ec7efb LP |
401 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
402 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
23b298bc LP |
403 | _cleanup_free_ char *buf = NULL, *joined = NULL; |
404 | const char *name; | |
45ec7efb LP |
405 | int r; |
406 | ||
407 | assert(ret); | |
23b298bc LP |
408 | |
409 | /* We support three modes of invocation: | |
410 | * | |
411 | * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service | |
412 | * type and possibly a service name. If specified in this way we assume it's already IDNA converted if | |
413 | * that's necessary. | |
414 | * | |
415 | * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD | |
416 | * style prefix. In this case we'll IDNA convert the domain, if that's requested. | |
417 | * | |
418 | * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put | |
419 | * together. The service name is never IDNA converted, and the domain is if requested. | |
420 | * | |
421 | * It's not supported to specify a service name without a type, or no domain name. | |
422 | */ | |
423 | ||
424 | if (!domain) | |
425 | return -EINVAL; | |
426 | ||
427 | if (type) { | |
428 | if (convert_idna) { | |
429 | r = dns_name_apply_idna(domain, &buf); | |
430 | if (r < 0) | |
431 | return r; | |
87057e24 ZJS |
432 | if (r > 0) |
433 | domain = buf; | |
23b298bc LP |
434 | } |
435 | ||
436 | r = dns_service_join(service, type, domain, &joined); | |
437 | if (r < 0) | |
438 | return r; | |
439 | ||
440 | name = joined; | |
441 | } else { | |
442 | if (service) | |
443 | return -EINVAL; | |
444 | ||
445 | name = domain; | |
446 | } | |
45ec7efb LP |
447 | |
448 | q = dns_question_new(1 + with_txt); | |
449 | if (!q) | |
450 | return -ENOMEM; | |
451 | ||
452 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name); | |
453 | if (!key) | |
454 | return -ENOMEM; | |
455 | ||
456 | r = dns_question_add(q, key); | |
457 | if (r < 0) | |
458 | return r; | |
459 | ||
460 | if (with_txt) { | |
461 | dns_resource_key_unref(key); | |
462 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name); | |
463 | if (!key) | |
464 | return -ENOMEM; | |
465 | ||
466 | r = dns_question_add(q, key); | |
467 | if (r < 0) | |
468 | return r; | |
469 | } | |
470 | ||
471 | *ret = q; | |
472 | q = NULL; | |
473 | ||
474 | return 0; | |
475 | } |