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