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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
faa133f3 | 2 | |
b5efdb8a | 3 | #include "alloc-util.h" |
4ad7f276 | 4 | #include "dns-domain.h" |
0f7091e6 | 5 | #include "dns-type.h" |
b5efdb8a | 6 | #include "resolved-dns-question.h" |
0438aa57 | 7 | #include "socket-util.h" |
faa133f3 | 8 | |
da6053d0 | 9 | DnsQuestion *dns_question_new(size_t n) { |
faa133f3 LP |
10 | DnsQuestion *q; |
11 | ||
398c6118 LP |
12 | if (n > UINT16_MAX) /* We can only place 64K key in an question section at max */ |
13 | n = UINT16_MAX; | |
faa133f3 | 14 | |
ab715ddb | 15 | q = malloc0(offsetof(DnsQuestion, items) + sizeof(DnsQuestionItem) * n); |
faa133f3 LP |
16 | if (!q) |
17 | return NULL; | |
18 | ||
19 | q->n_ref = 1; | |
20 | q->n_allocated = n; | |
21 | ||
22 | return q; | |
23 | } | |
24 | ||
8301aa0b | 25 | static DnsQuestion *dns_question_free(DnsQuestion *q) { |
ab715ddb | 26 | DnsResourceKey *key; |
faa133f3 | 27 | |
8301aa0b | 28 | assert(q); |
faa133f3 | 29 | |
ab715ddb SB |
30 | DNS_QUESTION_FOREACH(key, q) |
31 | dns_resource_key_unref(key); | |
32 | ||
8301aa0b | 33 | return mfree(q); |
faa133f3 LP |
34 | } |
35 | ||
8301aa0b YW |
36 | DEFINE_TRIVIAL_REF_UNREF_FUNC(DnsQuestion, dns_question, dns_question_free); |
37 | ||
ab715ddb | 38 | int dns_question_add_raw(DnsQuestion *q, DnsResourceKey *key, DnsQuestionFlags flags) { |
2d34cf0c ZJS |
39 | /* Insert without checking for duplicates. */ |
40 | ||
41 | assert(key); | |
42 | assert(q); | |
43 | ||
44 | if (q->n_keys >= q->n_allocated) | |
45 | return -ENOSPC; | |
46 | ||
ab715ddb SB |
47 | q->items[q->n_keys++] = (DnsQuestionItem) { |
48 | .key = dns_resource_key_ref(key), | |
49 | .flags = flags, | |
50 | }; | |
2d34cf0c ZJS |
51 | return 0; |
52 | } | |
53 | ||
4d593fb1 LP |
54 | static int dns_question_add_raw_all(DnsQuestion *a, DnsQuestion *b) { |
55 | DnsQuestionItem *item; | |
56 | int r; | |
57 | ||
58 | DNS_QUESTION_FOREACH_ITEM(item, b) { | |
59 | r = dns_question_add_raw(a, item->key, item->flags); | |
60 | if (r < 0) | |
61 | return r; | |
62 | } | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
ab715ddb SB |
67 | int dns_question_add(DnsQuestion *q, DnsResourceKey *key, DnsQuestionFlags flags) { |
68 | DnsQuestionItem *item; | |
7e8e0422 LP |
69 | int r; |
70 | ||
faa133f3 LP |
71 | assert(key); |
72 | ||
8013e860 LP |
73 | if (!q) |
74 | return -ENOSPC; | |
75 | ||
ab715ddb SB |
76 | |
77 | DNS_QUESTION_FOREACH_ITEM(item, q) { | |
78 | r = dns_resource_key_equal(item->key, key); | |
7e8e0422 LP |
79 | if (r < 0) |
80 | return r; | |
ab715ddb | 81 | if (r > 0 && item->flags == flags) |
7e8e0422 LP |
82 | return 0; |
83 | } | |
84 | ||
ab715ddb | 85 | return dns_question_add_raw(q, key, flags); |
faa133f3 LP |
86 | } |
87 | ||
4d593fb1 LP |
88 | static int dns_question_add_all(DnsQuestion *a, DnsQuestion *b) { |
89 | DnsQuestionItem *item; | |
90 | int r; | |
91 | ||
92 | DNS_QUESTION_FOREACH_ITEM(item, b) { | |
93 | r = dns_question_add(a, item->key, item->flags); | |
94 | if (r < 0) | |
95 | return r; | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } | |
100 | ||
801ad6a6 | 101 | int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
ab715ddb | 102 | DnsResourceKey *key; |
faa133f3 LP |
103 | int r; |
104 | ||
faa133f3 LP |
105 | assert(rr); |
106 | ||
8013e860 LP |
107 | if (!q) |
108 | return 0; | |
109 | ||
ab715ddb SB |
110 | DNS_QUESTION_FOREACH(key, q) { |
111 | r = dns_resource_key_match_rr(key, rr, search_domain); | |
faa133f3 LP |
112 | if (r != 0) |
113 | return r; | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
542e0c84 | 119 | int dns_question_matches_cname_or_dname(DnsQuestion *q, DnsResourceRecord *rr, const char *search_domain) { |
ab715ddb | 120 | DnsResourceKey *key; |
faa133f3 LP |
121 | int r; |
122 | ||
faa133f3 LP |
123 | assert(rr); |
124 | ||
8013e860 LP |
125 | if (!q) |
126 | return 0; | |
127 | ||
542e0c84 LP |
128 | if (!IN_SET(rr->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)) |
129 | return 0; | |
130 | ||
ab715ddb | 131 | DNS_QUESTION_FOREACH(key, q) { |
542e0c84 | 132 | /* For a {C,D}NAME record we can never find a matching {C,D}NAME record */ |
ab715ddb | 133 | if (!dns_type_may_redirect(key->type)) |
542e0c84 LP |
134 | return 0; |
135 | ||
ab715ddb | 136 | r = dns_resource_key_match_cname_or_dname(key, rr->key, search_domain); |
faa133f3 LP |
137 | if (r != 0) |
138 | return r; | |
139 | } | |
140 | ||
34b9656f | 141 | return 0; |
faa133f3 LP |
142 | } |
143 | ||
703e4f5e | 144 | int dns_question_is_valid_for_query(DnsQuestion *q) { |
faa133f3 | 145 | const char *name; |
da6053d0 | 146 | size_t i; |
faa133f3 LP |
147 | int r; |
148 | ||
8013e860 LP |
149 | if (!q) |
150 | return 0; | |
faa133f3 LP |
151 | |
152 | if (q->n_keys <= 0) | |
153 | return 0; | |
154 | ||
155 | if (q->n_keys > 65535) | |
156 | return 0; | |
157 | ||
ab715ddb | 158 | name = dns_resource_key_name(q->items[0].key); |
faa133f3 LP |
159 | if (!name) |
160 | return 0; | |
161 | ||
162 | /* Check that all keys in this question bear the same name */ | |
0f7091e6 | 163 | for (i = 0; i < q->n_keys; i++) { |
ab715ddb | 164 | assert(q->items[i].key); |
34b9656f | 165 | |
0f7091e6 | 166 | if (i > 0) { |
ab715ddb | 167 | r = dns_name_equal(dns_resource_key_name(q->items[i].key), name); |
0f7091e6 LP |
168 | if (r <= 0) |
169 | return r; | |
170 | } | |
171 | ||
ab715ddb | 172 | if (!dns_type_is_valid_query(q->items[i].key->type)) |
0f7091e6 | 173 | return 0; |
faa133f3 LP |
174 | } |
175 | ||
176 | return 1; | |
177 | } | |
178 | ||
ab715ddb | 179 | int dns_question_contains_key(DnsQuestion *q, const DnsResourceKey *k) { |
da6053d0 | 180 | size_t j; |
1086182d LP |
181 | int r; |
182 | ||
1086182d LP |
183 | assert(k); |
184 | ||
ab715ddb | 185 | if (!q) |
8013e860 LP |
186 | return 0; |
187 | ||
ab715ddb SB |
188 | |
189 | for (j = 0; j < q->n_keys; j++) { | |
190 | r = dns_resource_key_equal(q->items[j].key, k); | |
1086182d LP |
191 | if (r != 0) |
192 | return r; | |
193 | } | |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
ab715ddb SB |
198 | static int dns_question_contains_item(DnsQuestion *q, const DnsQuestionItem *i) { |
199 | DnsQuestionItem *item; | |
200 | int r; | |
201 | ||
202 | assert(i); | |
203 | ||
204 | DNS_QUESTION_FOREACH_ITEM(item, q) { | |
205 | if (item->flags != i->flags) | |
206 | continue; | |
207 | r = dns_resource_key_equal(item->key, i->key); | |
208 | if (r != 0) | |
209 | return r; | |
210 | } | |
211 | ||
212 | return false; | |
213 | } | |
214 | ||
1086182d | 215 | int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { |
ab715ddb | 216 | DnsQuestionItem *item; |
1086182d LP |
217 | int r; |
218 | ||
b6800689 LP |
219 | if (a == b) |
220 | return 1; | |
221 | ||
8013e860 LP |
222 | if (!a) |
223 | return !b || b->n_keys == 0; | |
224 | if (!b) | |
225 | return a->n_keys == 0; | |
1086182d | 226 | |
ab715ddb | 227 | /* Checks if all items in a are also contained b, and vice versa */ |
1086182d | 228 | |
ab715ddb SB |
229 | DNS_QUESTION_FOREACH_ITEM(item, a) { |
230 | r = dns_question_contains_item(b, item); | |
1086182d LP |
231 | if (r <= 0) |
232 | return r; | |
233 | } | |
ab715ddb SB |
234 | DNS_QUESTION_FOREACH_ITEM(item, b) { |
235 | r = dns_question_contains_item(a, item); | |
1086182d LP |
236 | if (r <= 0) |
237 | return r; | |
238 | } | |
239 | ||
240 | return 1; | |
241 | } | |
242 | ||
36d9205d | 243 | int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { |
faa133f3 | 244 | _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; |
23b298bc | 245 | DnsResourceKey *key; |
faa133f3 | 246 | bool same = true; |
faa133f3 LP |
247 | int r; |
248 | ||
36d9205d | 249 | assert(cname); |
faa133f3 | 250 | assert(ret); |
58db254a | 251 | assert(IN_SET(cname->key->type, DNS_TYPE_CNAME, DNS_TYPE_DNAME)); |
faa133f3 | 252 | |
23b298bc LP |
253 | if (dns_question_size(q) <= 0) { |
254 | *ret = NULL; | |
8013e860 LP |
255 | return 0; |
256 | } | |
257 | ||
23b298bc | 258 | DNS_QUESTION_FOREACH(key, q) { |
58db254a LP |
259 | _cleanup_free_ char *destination = NULL; |
260 | const char *d; | |
261 | ||
262 | if (cname->key->type == DNS_TYPE_CNAME) | |
263 | d = cname->cname.name; | |
264 | else { | |
1c02e7ba | 265 | r = dns_name_change_suffix(dns_resource_key_name(key), dns_resource_key_name(cname->key), cname->dname.name, &destination); |
58db254a LP |
266 | if (r < 0) |
267 | return r; | |
268 | if (r == 0) | |
269 | continue; | |
270 | ||
271 | d = destination; | |
272 | } | |
273 | ||
1c02e7ba | 274 | r = dns_name_equal(dns_resource_key_name(key), d); |
faa133f3 LP |
275 | if (r < 0) |
276 | return r; | |
277 | ||
278 | if (r == 0) { | |
279 | same = false; | |
280 | break; | |
281 | } | |
282 | } | |
283 | ||
23b298bc | 284 | /* Fully the same, indicate we didn't do a thing */ |
faa133f3 | 285 | if (same) { |
23b298bc | 286 | *ret = NULL; |
faa133f3 LP |
287 | return 0; |
288 | } | |
289 | ||
290 | n = dns_question_new(q->n_keys); | |
291 | if (!n) | |
292 | return -ENOMEM; | |
293 | ||
294 | /* Create a new question, and patch in the new name */ | |
23b298bc | 295 | DNS_QUESTION_FOREACH(key, q) { |
faa133f3 LP |
296 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; |
297 | ||
23b298bc | 298 | k = dns_resource_key_new_redirect(key, cname); |
faa133f3 LP |
299 | if (!k) |
300 | return -ENOMEM; | |
301 | ||
ab715ddb | 302 | r = dns_question_add(n, k, 0); |
faa133f3 LP |
303 | if (r < 0) |
304 | return r; | |
305 | } | |
306 | ||
1cc6c93a | 307 | *ret = TAKE_PTR(n); |
faa133f3 LP |
308 | |
309 | return 1; | |
310 | } | |
45ec7efb | 311 | |
703e4f5e LP |
312 | const char *dns_question_first_name(DnsQuestion *q) { |
313 | ||
314 | if (!q) | |
315 | return NULL; | |
45ec7efb LP |
316 | |
317 | if (q->n_keys < 1) | |
318 | return NULL; | |
319 | ||
ab715ddb | 320 | return dns_resource_key_name(q->items[0].key); |
45ec7efb LP |
321 | } |
322 | ||
23b298bc | 323 | int dns_question_new_address(DnsQuestion **ret, int family, const char *name, bool convert_idna) { |
45ec7efb | 324 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; |
23b298bc | 325 | _cleanup_free_ char *buf = NULL; |
45ec7efb LP |
326 | int r; |
327 | ||
328 | assert(ret); | |
329 | assert(name); | |
330 | ||
331 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
332 | return -EAFNOSUPPORT; | |
333 | ||
0438aa57 LP |
334 | /* If IPv6 is off and the request has an unspecified lookup family, restrict it automatically to |
335 | * IPv4. */ | |
336 | if (family == AF_UNSPEC && !socket_ipv6_is_enabled()) | |
337 | family = AF_INET; | |
338 | ||
23b298bc LP |
339 | if (convert_idna) { |
340 | r = dns_name_apply_idna(name, &buf); | |
341 | if (r < 0) | |
342 | return r; | |
ad1f3fe6 | 343 | if (r > 0 && !streq(name, buf)) |
87057e24 | 344 | name = buf; |
ad1f3fe6 ZJS |
345 | else |
346 | /* We did not manage to create convert the idna name, or it's | |
347 | * the same as the original name. We assume the caller already | |
5238e957 | 348 | * created an unconverted question, so let's not repeat work |
ad1f3fe6 ZJS |
349 | * unnecessarily. */ |
350 | return -EALREADY; | |
23b298bc LP |
351 | } |
352 | ||
45ec7efb LP |
353 | q = dns_question_new(family == AF_UNSPEC ? 2 : 1); |
354 | if (!q) | |
355 | return -ENOMEM; | |
356 | ||
357 | if (family != AF_INET6) { | |
358 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
359 | ||
360 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, name); | |
361 | if (!key) | |
362 | return -ENOMEM; | |
363 | ||
ab715ddb | 364 | r = dns_question_add(q, key, 0); |
45ec7efb LP |
365 | if (r < 0) |
366 | return r; | |
367 | } | |
368 | ||
369 | if (family != AF_INET) { | |
370 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
371 | ||
372 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, name); | |
373 | if (!key) | |
374 | return -ENOMEM; | |
375 | ||
ab715ddb | 376 | r = dns_question_add(q, key, 0); |
45ec7efb LP |
377 | if (r < 0) |
378 | return r; | |
379 | } | |
380 | ||
1cc6c93a | 381 | *ret = TAKE_PTR(q); |
45ec7efb LP |
382 | |
383 | return 0; | |
384 | } | |
385 | ||
386 | int dns_question_new_reverse(DnsQuestion **ret, int family, const union in_addr_union *a) { | |
387 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
388 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
389 | _cleanup_free_ char *reverse = NULL; | |
390 | int r; | |
391 | ||
392 | assert(ret); | |
393 | assert(a); | |
394 | ||
395 | if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC)) | |
396 | return -EAFNOSUPPORT; | |
397 | ||
398 | r = dns_name_reverse(family, a, &reverse); | |
399 | if (r < 0) | |
400 | return r; | |
401 | ||
402 | q = dns_question_new(1); | |
403 | if (!q) | |
404 | return -ENOMEM; | |
405 | ||
406 | key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse); | |
407 | if (!key) | |
408 | return -ENOMEM; | |
409 | ||
410 | reverse = NULL; | |
411 | ||
ab715ddb | 412 | r = dns_question_add(q, key, 0); |
45ec7efb LP |
413 | if (r < 0) |
414 | return r; | |
415 | ||
1cc6c93a | 416 | *ret = TAKE_PTR(q); |
45ec7efb LP |
417 | |
418 | return 0; | |
419 | } | |
420 | ||
23b298bc LP |
421 | int dns_question_new_service( |
422 | DnsQuestion **ret, | |
423 | const char *service, | |
424 | const char *type, | |
425 | const char *domain, | |
426 | bool with_txt, | |
427 | bool convert_idna) { | |
428 | ||
45ec7efb LP |
429 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
430 | _cleanup_(dns_question_unrefp) DnsQuestion *q = NULL; | |
23b298bc LP |
431 | _cleanup_free_ char *buf = NULL, *joined = NULL; |
432 | const char *name; | |
45ec7efb LP |
433 | int r; |
434 | ||
435 | assert(ret); | |
23b298bc LP |
436 | |
437 | /* We support three modes of invocation: | |
438 | * | |
439 | * 1. Only a domain is specified, in which case we assume a properly encoded SRV RR name, including service | |
440 | * type and possibly a service name. If specified in this way we assume it's already IDNA converted if | |
441 | * that's necessary. | |
442 | * | |
443 | * 2. Both service type and a domain specified, in which case a normal SRV RR is assumed, without a DNS-SD | |
444 | * style prefix. In this case we'll IDNA convert the domain, if that's requested. | |
445 | * | |
446 | * 3. All three of service name, type and domain are specified, in which case a DNS-SD service is put | |
447 | * together. The service name is never IDNA converted, and the domain is if requested. | |
448 | * | |
449 | * It's not supported to specify a service name without a type, or no domain name. | |
450 | */ | |
451 | ||
452 | if (!domain) | |
453 | return -EINVAL; | |
454 | ||
455 | if (type) { | |
456 | if (convert_idna) { | |
457 | r = dns_name_apply_idna(domain, &buf); | |
458 | if (r < 0) | |
459 | return r; | |
87057e24 ZJS |
460 | if (r > 0) |
461 | domain = buf; | |
23b298bc LP |
462 | } |
463 | ||
464 | r = dns_service_join(service, type, domain, &joined); | |
465 | if (r < 0) | |
466 | return r; | |
467 | ||
468 | name = joined; | |
469 | } else { | |
470 | if (service) | |
471 | return -EINVAL; | |
472 | ||
473 | name = domain; | |
474 | } | |
45ec7efb LP |
475 | |
476 | q = dns_question_new(1 + with_txt); | |
477 | if (!q) | |
478 | return -ENOMEM; | |
479 | ||
480 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_SRV, name); | |
481 | if (!key) | |
482 | return -ENOMEM; | |
483 | ||
ab715ddb | 484 | r = dns_question_add(q, key, 0); |
45ec7efb LP |
485 | if (r < 0) |
486 | return r; | |
487 | ||
488 | if (with_txt) { | |
489 | dns_resource_key_unref(key); | |
490 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_TXT, name); | |
491 | if (!key) | |
492 | return -ENOMEM; | |
493 | ||
ab715ddb | 494 | r = dns_question_add(q, key, 0); |
45ec7efb LP |
495 | if (r < 0) |
496 | return r; | |
497 | } | |
498 | ||
1cc6c93a | 499 | *ret = TAKE_PTR(q); |
45ec7efb LP |
500 | |
501 | return 0; | |
502 | } | |
1414b67e LP |
503 | |
504 | /* | |
505 | * This function is not used in the code base, but is useful when debugging. Do not delete. | |
506 | */ | |
507 | void dns_question_dump(DnsQuestion *question, FILE *f) { | |
508 | DnsResourceKey *k; | |
509 | ||
510 | if (!f) | |
511 | f = stdout; | |
512 | ||
513 | DNS_QUESTION_FOREACH(k, question) { | |
514 | char buf[DNS_RESOURCE_KEY_STRING_MAX]; | |
515 | ||
516 | fputc('\t', f); | |
517 | fputs(dns_resource_key_to_string(k, buf, sizeof(buf)), f); | |
518 | fputc('\n', f); | |
519 | } | |
520 | } | |
4d593fb1 LP |
521 | |
522 | int dns_question_merge(DnsQuestion *a, DnsQuestion *b, DnsQuestion **ret) { | |
523 | _cleanup_(dns_question_unrefp) DnsQuestion *k = NULL; | |
524 | int r; | |
525 | ||
526 | assert(ret); | |
527 | ||
528 | if (a == b || dns_question_size(b) <= 0) { | |
529 | *ret = dns_question_ref(a); | |
530 | return 0; | |
531 | } | |
532 | ||
533 | if (dns_question_size(a) <= 0) { | |
534 | *ret = dns_question_ref(b); | |
535 | return 0; | |
536 | } | |
537 | ||
538 | k = dns_question_new(dns_question_size(a) + dns_question_size(b)); | |
539 | if (!k) | |
540 | return -ENOMEM; | |
541 | ||
542 | r = dns_question_add_raw_all(k, a); | |
543 | if (r < 0) | |
544 | return r; | |
545 | ||
546 | r = dns_question_add_all(k, b); | |
547 | if (r < 0) | |
548 | return r; | |
549 | ||
550 | *ret = TAKE_PTR(k); | |
551 | return 0; | |
552 | } |