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74b2466e 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" |
2a1037af | 23 | #include "dns-domain.h" |
b5efdb8a | 24 | #include "hostname-util.h" |
78c6a153 | 25 | #include "local-addresses.h" |
74b2466e | 26 | #include "resolved-dns-query.h" |
74b2466e | 27 | |
0c903ae7 | 28 | /* How long to wait for the query in total */ |
74b2466e | 29 | #define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC) |
0c903ae7 | 30 | |
8ba9fd9c | 31 | #define CNAME_MAX 8 |
39762fdf | 32 | #define QUERIES_MAX 2048 |
45ec7efb | 33 | #define AUXILIARY_QUERIES_MAX 64 |
8ba9fd9c | 34 | |
801ad6a6 LP |
35 | static int dns_query_candidate_new(DnsQueryCandidate **ret, DnsQuery *q, DnsScope *s) { |
36 | DnsQueryCandidate *c; | |
74b2466e | 37 | |
801ad6a6 | 38 | assert(ret); |
faa133f3 | 39 | assert(q); |
801ad6a6 | 40 | assert(s); |
74b2466e | 41 | |
801ad6a6 LP |
42 | c = new0(DnsQueryCandidate, 1); |
43 | if (!c) | |
44 | return -ENOMEM; | |
45 | ||
46 | c->query = q; | |
47 | c->scope = s; | |
48 | ||
49 | LIST_PREPEND(candidates_by_query, q->candidates, c); | |
50 | LIST_PREPEND(candidates_by_scope, s->query_candidates, c); | |
51 | ||
52 | *ret = c; | |
53 | return 0; | |
54 | } | |
55 | ||
56 | static void dns_query_candidate_stop(DnsQueryCandidate *c) { | |
57 | DnsTransaction *t; | |
74b2466e | 58 | |
801ad6a6 LP |
59 | assert(c); |
60 | ||
61 | while ((t = set_steal_first(c->transactions))) { | |
62 | set_remove(t->query_candidates, c); | |
ec2c5e43 | 63 | dns_transaction_gc(t); |
74b2466e | 64 | } |
74b2466e LP |
65 | } |
66 | ||
801ad6a6 LP |
67 | DnsQueryCandidate* dns_query_candidate_free(DnsQueryCandidate *c) { |
68 | ||
69 | if (!c) | |
70 | return NULL; | |
71 | ||
72 | dns_query_candidate_stop(c); | |
73 | ||
74 | set_free(c->transactions); | |
75 | dns_search_domain_unref(c->search_domain); | |
76 | ||
77 | if (c->query) | |
78 | LIST_REMOVE(candidates_by_query, c->query->candidates, c); | |
79 | ||
80 | if (c->scope) | |
81 | LIST_REMOVE(candidates_by_scope, c->scope->query_candidates, c); | |
82 | ||
83 | free(c); | |
84 | ||
85 | return NULL; | |
86 | } | |
87 | ||
88 | static int dns_query_candidate_next_search_domain(DnsQueryCandidate *c) { | |
801ad6a6 LP |
89 | DnsSearchDomain *next = NULL; |
90 | ||
91 | assert(c); | |
92 | ||
93 | if (c->search_domain && c->search_domain->linked) { | |
94 | next = c->search_domain->domains_next; | |
95 | ||
6627b7e2 LP |
96 | if (!next) /* We hit the end of the list */ |
97 | return 0; | |
801ad6a6 LP |
98 | |
99 | } else { | |
801ad6a6 LP |
100 | next = dns_scope_get_search_domains(c->scope); |
101 | ||
6627b7e2 | 102 | if (!next) /* OK, there's nothing. */ |
801ad6a6 LP |
103 | return 0; |
104 | } | |
105 | ||
106 | dns_search_domain_unref(c->search_domain); | |
107 | c->search_domain = dns_search_domain_ref(next); | |
6627b7e2 | 108 | |
801ad6a6 LP |
109 | return 1; |
110 | } | |
111 | ||
112 | static int dns_query_candidate_add_transaction(DnsQueryCandidate *c, DnsResourceKey *key) { | |
113 | DnsTransaction *t; | |
114 | int r; | |
115 | ||
116 | assert(c); | |
117 | assert(key); | |
118 | ||
119 | r = set_ensure_allocated(&c->transactions, NULL); | |
120 | if (r < 0) | |
121 | return r; | |
122 | ||
123 | t = dns_scope_find_transaction(c->scope, key, true); | |
124 | if (!t) { | |
125 | r = dns_transaction_new(&t, c->scope, key); | |
126 | if (r < 0) | |
127 | return r; | |
128 | } | |
129 | ||
130 | r = set_ensure_allocated(&t->query_candidates, NULL); | |
131 | if (r < 0) | |
132 | goto gc; | |
133 | ||
134 | r = set_put(t->query_candidates, c); | |
135 | if (r < 0) | |
136 | goto gc; | |
137 | ||
138 | r = set_put(c->transactions, t); | |
139 | if (r < 0) { | |
140 | set_remove(t->query_candidates, c); | |
141 | goto gc; | |
142 | } | |
143 | ||
144 | return 0; | |
145 | ||
146 | gc: | |
147 | dns_transaction_gc(t); | |
148 | return r; | |
149 | } | |
150 | ||
151 | static int dns_query_candidate_go(DnsQueryCandidate *c) { | |
152 | DnsTransaction *t; | |
153 | Iterator i; | |
154 | int r; | |
155 | ||
156 | assert(c); | |
157 | ||
158 | /* Start the transactions that are not started yet */ | |
159 | SET_FOREACH(t, c->transactions, i) { | |
160 | if (t->state != DNS_TRANSACTION_NULL) | |
161 | continue; | |
162 | ||
163 | r = dns_transaction_go(t); | |
164 | if (r < 0) | |
165 | return r; | |
166 | } | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | static DnsTransactionState dns_query_candidate_state(DnsQueryCandidate *c) { | |
172 | DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; | |
173 | DnsTransaction *t; | |
174 | Iterator i; | |
175 | ||
176 | assert(c); | |
177 | ||
178 | if (c->error_code != 0) | |
179 | return DNS_TRANSACTION_RESOURCES; | |
180 | ||
181 | SET_FOREACH(t, c->transactions, i) { | |
182 | ||
183 | switch (t->state) { | |
184 | ||
185 | case DNS_TRANSACTION_PENDING: | |
186 | case DNS_TRANSACTION_NULL: | |
187 | return t->state; | |
188 | ||
189 | case DNS_TRANSACTION_SUCCESS: | |
190 | state = t->state; | |
191 | break; | |
192 | ||
193 | default: | |
194 | if (state != DNS_TRANSACTION_SUCCESS) | |
195 | state = t->state; | |
196 | ||
197 | break; | |
198 | } | |
199 | } | |
200 | ||
201 | return state; | |
202 | } | |
203 | ||
204 | static int dns_query_candidate_setup_transactions(DnsQueryCandidate *c) { | |
205 | DnsResourceKey *key; | |
206 | int n = 0, r; | |
207 | ||
208 | assert(c); | |
209 | ||
210 | dns_query_candidate_stop(c); | |
211 | ||
212 | /* Create one transaction per question key */ | |
213 | DNS_QUESTION_FOREACH(key, c->query->question) { | |
214 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *new_key = NULL; | |
215 | ||
216 | if (c->search_domain) { | |
217 | r = dns_resource_key_new_append_suffix(&new_key, key, c->search_domain->name); | |
218 | if (r < 0) | |
219 | goto fail; | |
220 | } | |
221 | ||
222 | r = dns_query_candidate_add_transaction(c, new_key ?: key); | |
223 | if (r < 0) | |
224 | goto fail; | |
225 | ||
226 | n++; | |
227 | } | |
228 | ||
229 | return n; | |
230 | ||
231 | fail: | |
232 | dns_query_candidate_stop(c); | |
233 | return r; | |
234 | } | |
235 | ||
236 | void dns_query_candidate_ready(DnsQueryCandidate *c) { | |
237 | DnsTransactionState state; | |
238 | int r; | |
239 | ||
240 | assert(c); | |
241 | ||
242 | state = dns_query_candidate_state(c); | |
243 | ||
244 | if (IN_SET(state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) | |
245 | return; | |
246 | ||
247 | if (state != DNS_TRANSACTION_SUCCESS && c->search_domain) { | |
248 | ||
249 | r = dns_query_candidate_next_search_domain(c); | |
250 | if (r < 0) | |
251 | goto fail; | |
252 | ||
253 | if (r > 0) { | |
254 | /* OK, there's another search domain to try, let's do so. */ | |
255 | ||
256 | r = dns_query_candidate_setup_transactions(c); | |
257 | if (r < 0) | |
258 | goto fail; | |
259 | ||
260 | if (r > 0) { | |
261 | /* New transactions where queued. Start them and wait */ | |
262 | ||
263 | r = dns_query_candidate_go(c); | |
264 | if (r < 0) | |
265 | goto fail; | |
266 | ||
267 | return; | |
268 | } | |
269 | } | |
270 | ||
271 | } | |
272 | ||
273 | dns_query_ready(c->query); | |
274 | return; | |
275 | ||
276 | fail: | |
277 | log_warning_errno(r, "Failed to follow search domains: %m"); | |
278 | c->error_code = r; | |
279 | dns_query_ready(c->query); | |
280 | } | |
281 | ||
282 | static void dns_query_stop(DnsQuery *q) { | |
283 | DnsQueryCandidate *c; | |
284 | ||
285 | assert(q); | |
286 | ||
287 | q->timeout_event_source = sd_event_source_unref(q->timeout_event_source); | |
288 | ||
289 | LIST_FOREACH(candidates_by_query, c, q->candidates) | |
290 | dns_query_candidate_stop(c); | |
291 | } | |
292 | ||
74b2466e | 293 | DnsQuery *dns_query_free(DnsQuery *q) { |
74b2466e LP |
294 | if (!q) |
295 | return NULL; | |
296 | ||
45ec7efb LP |
297 | while (q->auxiliary_queries) |
298 | dns_query_free(q->auxiliary_queries); | |
299 | ||
300 | if (q->auxiliary_for) { | |
301 | assert(q->auxiliary_for->n_auxiliary_queries > 0); | |
302 | q->auxiliary_for->n_auxiliary_queries--; | |
303 | LIST_REMOVE(auxiliary_queries, q->auxiliary_for->auxiliary_queries, q); | |
304 | } | |
305 | ||
801ad6a6 LP |
306 | while (q->candidates) |
307 | dns_query_candidate_free(q->candidates); | |
322345fd | 308 | |
faa133f3 LP |
309 | dns_question_unref(q->question); |
310 | dns_answer_unref(q->answer); | |
801ad6a6 | 311 | dns_search_domain_unref(q->answer_search_domain); |
322345fd | 312 | |
ec2c5e43 | 313 | sd_bus_message_unref(q->request); |
82bd6ddd | 314 | sd_bus_track_unref(q->bus_track); |
74b2466e | 315 | |
39762fdf | 316 | if (q->manager) { |
74b2466e | 317 | LIST_REMOVE(queries, q->manager->dns_queries, q); |
39762fdf LP |
318 | q->manager->n_dns_queries--; |
319 | } | |
74b2466e | 320 | |
74b2466e LP |
321 | free(q); |
322 | ||
323 | return NULL; | |
324 | } | |
325 | ||
51323288 | 326 | int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex, uint64_t flags) { |
74b2466e | 327 | _cleanup_(dns_query_freep) DnsQuery *q = NULL; |
faa133f3 LP |
328 | unsigned i; |
329 | int r; | |
74b2466e LP |
330 | |
331 | assert(m); | |
faa133f3 | 332 | assert(question); |
74b2466e | 333 | |
703e4f5e | 334 | r = dns_question_is_valid_for_query(question); |
faa133f3 LP |
335 | if (r < 0) |
336 | return r; | |
74b2466e | 337 | |
39762fdf LP |
338 | if (m->n_dns_queries >= QUERIES_MAX) |
339 | return -EBUSY; | |
340 | ||
74b2466e LP |
341 | q = new0(DnsQuery, 1); |
342 | if (!q) | |
343 | return -ENOMEM; | |
344 | ||
faa133f3 | 345 | q->question = dns_question_ref(question); |
51323288 LP |
346 | q->ifindex = ifindex; |
347 | q->flags = flags; | |
801ad6a6 LP |
348 | q->answer_family = AF_UNSPEC; |
349 | q->answer_protocol = _DNS_PROTOCOL_INVALID; | |
322345fd | 350 | |
faa133f3 | 351 | for (i = 0; i < question->n_keys; i++) { |
e4501ed4 LP |
352 | _cleanup_free_ char *p; |
353 | ||
354 | r = dns_resource_key_to_string(question->keys[i], &p); | |
355 | if (r < 0) | |
356 | return r; | |
357 | ||
358 | log_debug("Looking up RR for %s", p); | |
74b2466e LP |
359 | } |
360 | ||
361 | LIST_PREPEND(queries, m->dns_queries, q); | |
39762fdf | 362 | m->n_dns_queries++; |
74b2466e LP |
363 | q->manager = m; |
364 | ||
8ba9fd9c LP |
365 | if (ret) |
366 | *ret = q; | |
367 | q = NULL; | |
368 | ||
369 | return 0; | |
370 | } | |
371 | ||
45ec7efb LP |
372 | int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for) { |
373 | assert(q); | |
374 | assert(auxiliary_for); | |
375 | ||
376 | /* Ensure that that the query is not auxiliary yet, and | |
377 | * nothing else is auxiliary to it either */ | |
378 | assert(!q->auxiliary_for); | |
379 | assert(!q->auxiliary_queries); | |
380 | ||
381 | /* Ensure that the unit we shall be made auxiliary for isn't | |
382 | * auxiliary itself */ | |
383 | assert(!auxiliary_for->auxiliary_for); | |
384 | ||
385 | if (auxiliary_for->n_auxiliary_queries >= AUXILIARY_QUERIES_MAX) | |
386 | return -EAGAIN; | |
387 | ||
388 | LIST_PREPEND(auxiliary_queries, auxiliary_for->auxiliary_queries, q); | |
389 | q->auxiliary_for = auxiliary_for; | |
390 | ||
391 | auxiliary_for->n_auxiliary_queries++; | |
392 | return 0; | |
393 | } | |
394 | ||
ec2c5e43 | 395 | static void dns_query_complete(DnsQuery *q, DnsTransactionState state) { |
8ba9fd9c | 396 | assert(q); |
ec2c5e43 LP |
397 | assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); |
398 | assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); | |
8ba9fd9c | 399 | |
322345fd LP |
400 | /* Note that this call might invalidate the query. Callers |
401 | * should hence not attempt to access the query or transaction | |
402 | * after calling this function. */ | |
8ba9fd9c | 403 | |
8ba9fd9c LP |
404 | q->state = state; |
405 | ||
322345fd LP |
406 | dns_query_stop(q); |
407 | if (q->complete) | |
408 | q->complete(q); | |
8ba9fd9c LP |
409 | } |
410 | ||
411 | static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) { | |
412 | DnsQuery *q = userdata; | |
413 | ||
414 | assert(s); | |
415 | assert(q); | |
416 | ||
ec2c5e43 | 417 | dns_query_complete(q, DNS_TRANSACTION_TIMEOUT); |
8ba9fd9c LP |
418 | return 0; |
419 | } | |
420 | ||
801ad6a6 LP |
421 | static int dns_query_add_candidate(DnsQuery *q, DnsScope *s) { |
422 | DnsQueryCandidate *c; | |
faa133f3 LP |
423 | int r; |
424 | ||
425 | assert(q); | |
ec2c5e43 | 426 | assert(s); |
faa133f3 | 427 | |
801ad6a6 | 428 | r = dns_query_candidate_new(&c, q, s); |
faa133f3 LP |
429 | if (r < 0) |
430 | return r; | |
431 | ||
801ad6a6 | 432 | /* If this a single-label domain on DNS, we might append a suitable search domain first. */ |
22f711bb LP |
433 | if ((q->flags & SD_RESOLVED_NO_SEARCH) == 0) { |
434 | r = dns_scope_name_needs_search_domain(s, dns_question_first_name(q->question)); | |
435 | if (r < 0) | |
801ad6a6 | 436 | goto fail; |
22f711bb LP |
437 | if (r > 0) { |
438 | /* OK, we need a search domain now. Let's find one for this scope */ | |
439 | ||
440 | r = dns_query_candidate_next_search_domain(c); | |
441 | if (r <= 0) /* if there's no search domain, then we won't add any transaction. */ | |
442 | goto fail; | |
443 | } | |
faa133f3 LP |
444 | } |
445 | ||
801ad6a6 LP |
446 | r = dns_query_candidate_setup_transactions(c); |
447 | if (r < 0) | |
448 | goto fail; | |
449 | ||
faa133f3 LP |
450 | return 0; |
451 | ||
801ad6a6 LP |
452 | fail: |
453 | dns_query_candidate_free(c); | |
faa133f3 LP |
454 | return r; |
455 | } | |
456 | ||
2a1037af LP |
457 | static int SYNTHESIZE_IFINDEX(int ifindex) { |
458 | ||
78c6a153 LP |
459 | /* When the caller asked for resolving on a specific |
460 | * interface, we synthesize the answer for that | |
461 | * interface. However, if nothing specific was claimed and we | |
462 | * only return localhost RRs, we synthesize the answer for | |
2a1037af LP |
463 | * localhost. */ |
464 | ||
465 | if (ifindex > 0) | |
466 | return ifindex; | |
467 | ||
468 | return LOOPBACK_IFINDEX; | |
469 | } | |
470 | ||
471 | static int SYNTHESIZE_FAMILY(uint64_t flags) { | |
472 | ||
473 | /* Picks an address family depending on set flags. This is | |
474 | * purely for synthesized answers, where the family we return | |
475 | * for the reply should match what was requested in the | |
476 | * question, even though we are synthesizing the answer | |
477 | * here. */ | |
478 | ||
479 | if (!(flags & SD_RESOLVED_DNS)) { | |
480 | if (flags & SD_RESOLVED_LLMNR_IPV4) | |
481 | return AF_INET; | |
482 | if (flags & SD_RESOLVED_LLMNR_IPV6) | |
483 | return AF_INET6; | |
484 | } | |
485 | ||
486 | return AF_UNSPEC; | |
487 | } | |
488 | ||
489 | static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) { | |
490 | ||
491 | /* Similar as SYNTHESIZE_FAMILY() but does this for the | |
492 | * protocol. If resolving via DNS was requested, we claim it | |
493 | * was DNS. Similar, if nothing specific was | |
494 | * requested. However, if only resolving via LLMNR was | |
495 | * requested we return that. */ | |
496 | ||
497 | if (flags & SD_RESOLVED_DNS) | |
498 | return DNS_PROTOCOL_DNS; | |
499 | if (flags & SD_RESOLVED_LLMNR) | |
500 | return DNS_PROTOCOL_LLMNR; | |
501 | ||
502 | return DNS_PROTOCOL_DNS; | |
503 | } | |
504 | ||
78c6a153 LP |
505 | static int dns_type_to_af(uint16_t t) { |
506 | switch (t) { | |
507 | ||
508 | case DNS_TYPE_A: | |
509 | return AF_INET; | |
510 | ||
511 | case DNS_TYPE_AAAA: | |
512 | return AF_INET6; | |
513 | ||
514 | case DNS_TYPE_ANY: | |
515 | return AF_UNSPEC; | |
516 | ||
517 | default: | |
518 | return -EINVAL; | |
519 | } | |
520 | } | |
521 | ||
522 | static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { | |
523 | int r; | |
524 | ||
525 | assert(q); | |
526 | assert(key); | |
527 | assert(answer); | |
528 | ||
529 | r = dns_answer_reserve(answer, 2); | |
530 | if (r < 0) | |
531 | return r; | |
532 | ||
533 | if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) { | |
534 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
535 | ||
536 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key)); | |
537 | if (!rr) | |
538 | return -ENOMEM; | |
539 | ||
540 | rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK); | |
541 | ||
542 | r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex)); | |
543 | if (r < 0) | |
544 | return r; | |
545 | } | |
546 | ||
547 | if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) { | |
548 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
549 | ||
550 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key)); | |
551 | if (!rr) | |
552 | return -ENOMEM; | |
553 | ||
554 | rr->aaaa.in6_addr = in6addr_loopback; | |
555 | ||
556 | r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex)); | |
557 | if (r < 0) | |
558 | return r; | |
559 | } | |
560 | ||
561 | return 0; | |
562 | } | |
563 | ||
564 | static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex) { | |
565 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
566 | ||
567 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from); | |
568 | if (!rr) | |
569 | return -ENOMEM; | |
570 | ||
571 | rr->ptr.name = strdup(to); | |
572 | if (!rr->ptr.name) | |
573 | return -ENOMEM; | |
574 | ||
575 | return dns_answer_add(*answer, rr, ifindex); | |
576 | } | |
577 | ||
578 | static int synthesize_localhost_ptr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { | |
579 | int r; | |
580 | ||
581 | assert(q); | |
582 | assert(key); | |
583 | assert(answer); | |
584 | ||
585 | r = dns_answer_reserve(answer, 1); | |
586 | if (r < 0) | |
587 | return r; | |
588 | ||
589 | if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) { | |
590 | r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex)); | |
591 | if (r < 0) | |
592 | return r; | |
593 | } | |
594 | ||
595 | return 0; | |
596 | } | |
597 | ||
598 | static int answer_add_addresses_rr( | |
599 | DnsAnswer **answer, | |
600 | const char *name, | |
601 | struct local_address *addresses, | |
602 | unsigned n_addresses) { | |
603 | ||
604 | unsigned j; | |
605 | int r; | |
606 | ||
607 | assert(answer); | |
608 | assert(name); | |
609 | ||
610 | r = dns_answer_reserve(answer, n_addresses); | |
611 | if (r < 0) | |
612 | return r; | |
613 | ||
614 | for (j = 0; j < n_addresses; j++) { | |
615 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
616 | ||
617 | r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name); | |
618 | if (r < 0) | |
619 | return r; | |
620 | ||
621 | r = dns_answer_add(*answer, rr, addresses[j].ifindex); | |
622 | if (r < 0) | |
623 | return r; | |
624 | } | |
625 | ||
626 | return 0; | |
627 | } | |
628 | ||
629 | static int answer_add_addresses_ptr( | |
630 | DnsAnswer **answer, | |
631 | const char *name, | |
632 | struct local_address *addresses, | |
633 | unsigned n_addresses, | |
634 | int af, const union in_addr_union *match) { | |
635 | ||
636 | unsigned j; | |
637 | int r; | |
638 | ||
639 | assert(answer); | |
640 | assert(name); | |
641 | ||
642 | for (j = 0; j < n_addresses; j++) { | |
643 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; | |
644 | ||
645 | if (af != AF_UNSPEC) { | |
646 | ||
647 | if (addresses[j].family != af) | |
648 | continue; | |
649 | ||
650 | if (match && !in_addr_equal(af, match, &addresses[j].address)) | |
651 | continue; | |
652 | } | |
653 | ||
654 | r = dns_answer_reserve(answer, 1); | |
655 | if (r < 0) | |
656 | return r; | |
657 | ||
658 | r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name); | |
659 | if (r < 0) | |
660 | return r; | |
661 | ||
662 | r = dns_answer_add(*answer, rr, addresses[j].ifindex); | |
663 | if (r < 0) | |
664 | return r; | |
665 | } | |
666 | ||
667 | return 0; | |
668 | } | |
669 | ||
670 | static int synthesize_system_hostname_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { | |
671 | _cleanup_free_ struct local_address *addresses = NULL; | |
672 | int n = 0, af; | |
673 | ||
674 | assert(q); | |
675 | assert(key); | |
676 | assert(answer); | |
677 | ||
678 | af = dns_type_to_af(key->type); | |
679 | if (af >= 0) { | |
680 | n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses); | |
681 | if (n < 0) | |
682 | return n; | |
683 | ||
684 | if (n == 0) { | |
685 | struct local_address buffer[2]; | |
686 | ||
687 | /* If we have no local addresses then use ::1 | |
688 | * and 127.0.0.2 as local ones. */ | |
689 | ||
690 | if (af == AF_INET || af == AF_UNSPEC) | |
691 | buffer[n++] = (struct local_address) { | |
692 | .family = AF_INET, | |
693 | .ifindex = SYNTHESIZE_IFINDEX(q->ifindex), | |
694 | .address.in.s_addr = htobe32(0x7F000002), | |
695 | }; | |
696 | ||
697 | if (af == AF_INET6 || af == AF_UNSPEC) | |
698 | buffer[n++] = (struct local_address) { | |
699 | .family = AF_INET6, | |
700 | .ifindex = SYNTHESIZE_IFINDEX(q->ifindex), | |
701 | .address.in6 = in6addr_loopback, | |
702 | }; | |
703 | ||
704 | return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n); | |
705 | } | |
706 | } | |
707 | ||
708 | return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n); | |
709 | } | |
710 | ||
711 | static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) { | |
712 | _cleanup_free_ struct local_address *addresses = NULL; | |
713 | int n, r; | |
714 | ||
715 | assert(q); | |
716 | assert(address); | |
717 | assert(answer); | |
718 | ||
719 | if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) { | |
720 | ||
721 | /* Always map the IPv4 address 127.0.0.2 to the local | |
722 | * hostname, in addition to "localhost": */ | |
723 | ||
724 | r = dns_answer_reserve(answer, 3); | |
725 | if (r < 0) | |
726 | return r; | |
727 | ||
728 | r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex)); | |
729 | if (r < 0) | |
730 | return r; | |
731 | ||
732 | r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex)); | |
733 | if (r < 0) | |
734 | return r; | |
735 | ||
736 | r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex)); | |
737 | if (r < 0) | |
738 | return r; | |
739 | ||
740 | return 0; | |
741 | } | |
742 | ||
743 | n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses); | |
744 | if (n < 0) | |
745 | return n; | |
746 | ||
747 | r = answer_add_addresses_ptr(answer, q->manager->llmnr_hostname, addresses, n, af, address); | |
748 | if (r < 0) | |
749 | return r; | |
750 | ||
751 | return answer_add_addresses_ptr(answer, q->manager->mdns_hostname, addresses, n, af, address); | |
752 | } | |
753 | ||
754 | static int synthesize_gateway_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) { | |
755 | _cleanup_free_ struct local_address *addresses = NULL; | |
756 | int n = 0, af; | |
757 | ||
758 | assert(q); | |
759 | assert(key); | |
760 | assert(answer); | |
761 | ||
762 | af = dns_type_to_af(key->type); | |
763 | if (af >= 0) { | |
764 | n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses); | |
765 | if (n < 0) | |
766 | return n; | |
767 | } | |
768 | ||
769 | return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n); | |
770 | } | |
771 | ||
772 | static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) { | |
773 | _cleanup_free_ struct local_address *addresses = NULL; | |
774 | int n; | |
775 | ||
776 | assert(q); | |
777 | assert(address); | |
778 | assert(answer); | |
779 | ||
780 | n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses); | |
781 | if (n < 0) | |
782 | return n; | |
783 | ||
784 | return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address); | |
785 | } | |
786 | ||
787 | static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) { | |
2a1037af LP |
788 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
789 | unsigned i; | |
790 | int r; | |
791 | ||
792 | assert(q); | |
793 | assert(state); | |
794 | ||
795 | /* Tries to synthesize localhost RR replies where appropriate */ | |
796 | ||
797 | if (!IN_SET(*state, | |
798 | DNS_TRANSACTION_FAILURE, | |
799 | DNS_TRANSACTION_NO_SERVERS, | |
800 | DNS_TRANSACTION_TIMEOUT, | |
801 | DNS_TRANSACTION_ATTEMPTS_MAX_REACHED)) | |
78c6a153 | 802 | return 0; |
2a1037af LP |
803 | |
804 | for (i = 0; i < q->question->n_keys; i++) { | |
78c6a153 | 805 | union in_addr_union address; |
2a1037af | 806 | const char *name; |
78c6a153 | 807 | int af; |
2a1037af LP |
808 | |
809 | if (q->question->keys[i]->class != DNS_CLASS_IN && | |
810 | q->question->keys[i]->class != DNS_CLASS_ANY) | |
811 | continue; | |
812 | ||
813 | name = DNS_RESOURCE_KEY_NAME(q->question->keys[i]); | |
814 | ||
815 | if (is_localhost(name)) { | |
816 | ||
78c6a153 LP |
817 | r = synthesize_localhost_rr(q, q->question->keys[i], &answer); |
818 | if (r < 0) | |
819 | return log_error_errno(r, "Failed to synthesize localhost RRs: %m"); | |
2a1037af | 820 | |
78c6a153 | 821 | } else if (manager_is_own_hostname(q->manager, name)) { |
2a1037af | 822 | |
78c6a153 LP |
823 | r = synthesize_system_hostname_rr(q, q->question->keys[i], &answer); |
824 | if (r < 0) | |
825 | return log_error_errno(r, "Failed to synthesize system hostname RRs: %m"); | |
2a1037af | 826 | |
78c6a153 | 827 | } else if (is_gateway_hostname(name)) { |
2a1037af | 828 | |
78c6a153 LP |
829 | r = synthesize_gateway_rr(q, q->question->keys[i], &answer); |
830 | if (r < 0) | |
831 | return log_error_errno(r, "Failed to synthesize gateway RRs: %m"); | |
2a1037af | 832 | |
78c6a153 LP |
833 | } else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) || |
834 | dns_name_equal(name, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) { | |
2a1037af | 835 | |
78c6a153 LP |
836 | r = synthesize_localhost_ptr(q, q->question->keys[i], &answer); |
837 | if (r < 0) | |
838 | return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m"); | |
2a1037af | 839 | |
78c6a153 | 840 | } else if (dns_name_address(name, &af, &address) > 0) { |
2a1037af | 841 | |
78c6a153 LP |
842 | r = synthesize_system_hostname_ptr(q, af, &address, &answer); |
843 | if (r < 0) | |
844 | return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m"); | |
2a1037af | 845 | |
78c6a153 LP |
846 | r = synthesize_gateway_ptr(q, af, &address, &answer); |
847 | if (r < 0) | |
848 | return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m"); | |
2a1037af LP |
849 | } |
850 | } | |
851 | ||
852 | if (!answer) | |
78c6a153 | 853 | return 0; |
2a1037af LP |
854 | |
855 | dns_answer_unref(q->answer); | |
856 | q->answer = answer; | |
857 | answer = NULL; | |
858 | ||
2a1037af | 859 | q->answer_rcode = DNS_RCODE_SUCCESS; |
801ad6a6 LP |
860 | q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags); |
861 | q->answer_family = SYNTHESIZE_FAMILY(q->flags); | |
2a1037af LP |
862 | |
863 | *state = DNS_TRANSACTION_SUCCESS; | |
78c6a153 LP |
864 | |
865 | return 1; | |
2a1037af LP |
866 | } |
867 | ||
322345fd | 868 | int dns_query_go(DnsQuery *q) { |
8ba9fd9c LP |
869 | DnsScopeMatch found = DNS_SCOPE_NO; |
870 | DnsScope *s, *first = NULL; | |
801ad6a6 | 871 | DnsQueryCandidate *c; |
faa133f3 | 872 | const char *name; |
8ba9fd9c LP |
873 | int r; |
874 | ||
875 | assert(q); | |
876 | ||
ec2c5e43 | 877 | if (q->state != DNS_TRANSACTION_NULL) |
8ba9fd9c LP |
878 | return 0; |
879 | ||
faa133f3 LP |
880 | assert(q->question); |
881 | assert(q->question->n_keys > 0); | |
882 | ||
703e4f5e | 883 | name = dns_question_first_name(q->question); |
8ba9fd9c LP |
884 | |
885 | LIST_FOREACH(scopes, s, q->manager->dns_scopes) { | |
74b2466e LP |
886 | DnsScopeMatch match; |
887 | ||
51323288 | 888 | match = dns_scope_good_domain(s, q->ifindex, q->flags, name); |
74b2466e LP |
889 | if (match < 0) |
890 | return match; | |
891 | ||
892 | if (match == DNS_SCOPE_NO) | |
893 | continue; | |
894 | ||
895 | found = match; | |
896 | ||
897 | if (match == DNS_SCOPE_YES) { | |
898 | first = s; | |
899 | break; | |
900 | } else { | |
901 | assert(match == DNS_SCOPE_MAYBE); | |
902 | ||
903 | if (!first) | |
904 | first = s; | |
905 | } | |
906 | } | |
907 | ||
2a1037af LP |
908 | if (found == DNS_SCOPE_NO) { |
909 | DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; | |
910 | ||
911 | dns_query_synthesize_reply(q, &state); | |
d634711b LP |
912 | dns_query_complete(q, state); |
913 | return 1; | |
2a1037af | 914 | } |
74b2466e | 915 | |
801ad6a6 | 916 | r = dns_query_add_candidate(q, first); |
74b2466e | 917 | if (r < 0) |
ec2c5e43 | 918 | goto fail; |
74b2466e | 919 | |
74b2466e LP |
920 | LIST_FOREACH(scopes, s, first->scopes_next) { |
921 | DnsScopeMatch match; | |
922 | ||
51323288 | 923 | match = dns_scope_good_domain(s, q->ifindex, q->flags, name); |
74b2466e | 924 | if (match < 0) |
ec2c5e43 | 925 | goto fail; |
74b2466e LP |
926 | |
927 | if (match != found) | |
928 | continue; | |
929 | ||
801ad6a6 | 930 | r = dns_query_add_candidate(q, s); |
74b2466e | 931 | if (r < 0) |
ec2c5e43 | 932 | goto fail; |
74b2466e LP |
933 | } |
934 | ||
faa133f3 | 935 | q->answer = dns_answer_unref(q->answer); |
faa133f3 | 936 | q->answer_rcode = 0; |
51323288 LP |
937 | q->answer_family = AF_UNSPEC; |
938 | q->answer_protocol = _DNS_PROTOCOL_INVALID; | |
74b2466e | 939 | |
9a015429 LP |
940 | r = sd_event_add_time( |
941 | q->manager->event, | |
942 | &q->timeout_event_source, | |
943 | clock_boottime_or_monotonic(), | |
944 | now(clock_boottime_or_monotonic()) + QUERY_TIMEOUT_USEC, 0, | |
945 | on_query_timeout, q); | |
74b2466e LP |
946 | if (r < 0) |
947 | goto fail; | |
948 | ||
ec2c5e43 | 949 | q->state = DNS_TRANSACTION_PENDING; |
faa133f3 | 950 | q->block_ready++; |
74b2466e | 951 | |
801ad6a6 LP |
952 | /* Start the transactions */ |
953 | LIST_FOREACH(candidates_by_query, c, q->candidates) { | |
954 | r = dns_query_candidate_go(c); | |
955 | if (r < 0) { | |
956 | q->block_ready--; | |
ec2c5e43 | 957 | goto fail; |
801ad6a6 | 958 | } |
74b2466e LP |
959 | } |
960 | ||
faa133f3 LP |
961 | q->block_ready--; |
962 | dns_query_ready(q); | |
322345fd | 963 | |
8ba9fd9c | 964 | return 1; |
74b2466e LP |
965 | |
966 | fail: | |
8ba9fd9c | 967 | dns_query_stop(q); |
74b2466e LP |
968 | return r; |
969 | } | |
970 | ||
801ad6a6 | 971 | static void dns_query_accept(DnsQuery *q, DnsQueryCandidate *c) { |
ec2c5e43 | 972 | DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS; |
801ad6a6 | 973 | DnsTransaction *t; |
faa133f3 | 974 | Iterator i; |
74b2466e LP |
975 | |
976 | assert(q); | |
977 | ||
801ad6a6 LP |
978 | if (!c) { |
979 | dns_query_synthesize_reply(q, &state); | |
980 | dns_query_complete(q, state); | |
74b2466e | 981 | return; |
801ad6a6 | 982 | } |
74b2466e | 983 | |
801ad6a6 | 984 | SET_FOREACH(t, c->transactions, i) { |
74b2466e | 985 | |
801ad6a6 | 986 | switch (t->state) { |
934e9b10 | 987 | |
801ad6a6 LP |
988 | case DNS_TRANSACTION_SUCCESS: { |
989 | /* We found a successfuly reply, merge it into the answer */ | |
ae6a4bbf | 990 | DnsAnswer *merged; |
322345fd | 991 | |
ae6a4bbf | 992 | merged = dns_answer_merge(q->answer, t->answer); |
801ad6a6 LP |
993 | if (!merged) { |
994 | dns_query_complete(q, DNS_TRANSACTION_RESOURCES); | |
995 | return; | |
996 | } | |
997 | ||
998 | dns_answer_unref(q->answer); | |
999 | q->answer = merged; | |
ae6a4bbf | 1000 | q->answer_rcode = t->answer_rcode; |
801ad6a6 LP |
1001 | |
1002 | state = DNS_TRANSACTION_SUCCESS; | |
1003 | break; | |
1004 | } | |
1005 | ||
1006 | case DNS_TRANSACTION_PENDING: | |
1007 | case DNS_TRANSACTION_NULL: | |
1008 | case DNS_TRANSACTION_ABORTED: | |
1009 | /* Ignore transactions that didn't complete */ | |
1010 | continue; | |
1011 | ||
1012 | default: | |
1013 | /* Any kind of failure? Store the data away, | |
1014 | * if there's nothing stored yet. */ | |
934e9b10 | 1015 | |
801ad6a6 LP |
1016 | if (state != DNS_TRANSACTION_SUCCESS) { |
1017 | ||
1018 | dns_answer_unref(q->answer); | |
ae6a4bbf LP |
1019 | q->answer = dns_answer_ref(t->answer); |
1020 | q->answer_rcode = t->answer_rcode; | |
934e9b10 | 1021 | |
801ad6a6 | 1022 | state = t->state; |
934e9b10 LP |
1023 | } |
1024 | ||
801ad6a6 | 1025 | break; |
74b2466e | 1026 | } |
801ad6a6 | 1027 | } |
74b2466e | 1028 | |
801ad6a6 LP |
1029 | q->answer_protocol = c->scope->protocol; |
1030 | q->answer_family = c->scope->family; | |
934e9b10 | 1031 | |
801ad6a6 LP |
1032 | dns_search_domain_unref(q->answer_search_domain); |
1033 | q->answer_search_domain = dns_search_domain_ref(c->search_domain); | |
7e8e0422 | 1034 | |
801ad6a6 LP |
1035 | dns_query_synthesize_reply(q, &state); |
1036 | dns_query_complete(q, state); | |
1037 | } | |
934e9b10 | 1038 | |
801ad6a6 | 1039 | void dns_query_ready(DnsQuery *q) { |
74b2466e | 1040 | |
801ad6a6 LP |
1041 | DnsQueryCandidate *bad = NULL, *c; |
1042 | bool pending = false; | |
74b2466e | 1043 | |
801ad6a6 LP |
1044 | assert(q); |
1045 | assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING)); | |
e4501ed4 | 1046 | |
801ad6a6 LP |
1047 | /* Note that this call might invalidate the query. Callers |
1048 | * should hence not attempt to access the query or transaction | |
1049 | * after calling this function, unless the block_ready | |
1050 | * counter was explicitly bumped before doing so. */ | |
1051 | ||
1052 | if (q->block_ready > 0) | |
1053 | return; | |
1054 | ||
1055 | LIST_FOREACH(candidates_by_query, c, q->candidates) { | |
1056 | DnsTransactionState state; | |
1057 | ||
1058 | state = dns_query_candidate_state(c); | |
1059 | switch (state) { | |
1060 | ||
1061 | case DNS_TRANSACTION_SUCCESS: | |
1062 | /* One of the transactions is successful, | |
1063 | * let's use it, and copy its data out */ | |
1064 | dns_query_accept(q, c); | |
e4501ed4 LP |
1065 | return; |
1066 | ||
801ad6a6 LP |
1067 | case DNS_TRANSACTION_PENDING: |
1068 | case DNS_TRANSACTION_NULL: | |
1069 | /* One of the transactions is still going on, let's maybe wait for it */ | |
1070 | pending = true; | |
1071 | break; | |
e4501ed4 | 1072 | |
801ad6a6 LP |
1073 | default: |
1074 | /* Any kind of failure */ | |
1075 | bad = c; | |
1076 | break; | |
1077 | } | |
faa133f3 | 1078 | } |
74b2466e | 1079 | |
801ad6a6 LP |
1080 | if (pending) |
1081 | return; | |
2a1037af | 1082 | |
801ad6a6 | 1083 | dns_query_accept(q, bad); |
74b2466e | 1084 | } |
8ba9fd9c | 1085 | |
45ec7efb | 1086 | static int dns_query_cname_redirect(DnsQuery *q, const DnsResourceRecord *cname) { |
faa133f3 LP |
1087 | _cleanup_(dns_question_unrefp) DnsQuestion *nq = NULL; |
1088 | int r; | |
8ba9fd9c LP |
1089 | |
1090 | assert(q); | |
1091 | ||
45ec7efb | 1092 | q->n_cname_redirects ++; |
faa133f3 | 1093 | if (q->n_cname_redirects > CNAME_MAX) |
8ba9fd9c LP |
1094 | return -ELOOP; |
1095 | ||
36d9205d | 1096 | r = dns_question_cname_redirect(q->question, cname, &nq); |
faa133f3 LP |
1097 | if (r < 0) |
1098 | return r; | |
8ba9fd9c | 1099 | |
faa133f3 LP |
1100 | dns_question_unref(q->question); |
1101 | q->question = nq; | |
1102 | nq = NULL; | |
8ba9fd9c | 1103 | |
322345fd | 1104 | dns_query_stop(q); |
ec2c5e43 | 1105 | q->state = DNS_TRANSACTION_NULL; |
322345fd | 1106 | |
8ba9fd9c LP |
1107 | return 0; |
1108 | } | |
82bd6ddd | 1109 | |
45ec7efb LP |
1110 | int dns_query_process_cname(DnsQuery *q) { |
1111 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL; | |
1112 | DnsResourceRecord *rr; | |
1113 | int r; | |
1114 | ||
1115 | assert(q); | |
1116 | ||
1117 | if (q->state != DNS_TRANSACTION_SUCCESS) | |
1118 | return 0; | |
1119 | ||
1120 | DNS_ANSWER_FOREACH(rr, q->answer) { | |
1121 | ||
801ad6a6 | 1122 | r = dns_question_matches_rr(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); |
45ec7efb LP |
1123 | if (r < 0) |
1124 | return r; | |
1125 | if (r > 0) | |
1126 | return 0; /* The answer matches directly, no need to follow cnames */ | |
1127 | ||
801ad6a6 | 1128 | r = dns_question_matches_cname(q->question, rr, DNS_SEARCH_DOMAIN_NAME(q->answer_search_domain)); |
45ec7efb LP |
1129 | if (r < 0) |
1130 | return r; | |
1131 | if (r > 0 && !cname) | |
1132 | cname = dns_resource_record_ref(rr); | |
1133 | } | |
1134 | ||
1135 | if (!cname) | |
1136 | return 0; /* No cname to follow */ | |
1137 | ||
1138 | if (q->flags & SD_RESOLVED_NO_CNAME) | |
1139 | return -ELOOP; | |
1140 | ||
1141 | /* OK, let's actually follow the CNAME */ | |
1142 | r = dns_query_cname_redirect(q, cname); | |
1143 | if (r < 0) | |
1144 | return r; | |
1145 | ||
1146 | /* Let's see if the answer can already answer the new | |
1147 | * redirected question */ | |
1148 | DNS_ANSWER_FOREACH(rr, q->answer) { | |
801ad6a6 | 1149 | r = dns_question_matches_rr(q->question, rr, NULL); |
45ec7efb LP |
1150 | if (r < 0) |
1151 | return r; | |
1152 | if (r > 0) | |
1153 | return 0; /* It can answer it, yay! */ | |
1154 | } | |
1155 | ||
1156 | /* OK, it cannot, let's begin with the new query */ | |
1157 | r = dns_query_go(q); | |
1158 | if (r < 0) | |
1159 | return r; | |
1160 | ||
1161 | return 1; /* We return > 0, if we restarted the query for a new cname */ | |
1162 | } | |
1163 | ||
82bd6ddd LP |
1164 | static int on_bus_track(sd_bus_track *t, void *userdata) { |
1165 | DnsQuery *q = userdata; | |
1166 | ||
1167 | assert(t); | |
1168 | assert(q); | |
1169 | ||
1170 | log_debug("Client of active query vanished, aborting query."); | |
1171 | dns_query_complete(q, DNS_TRANSACTION_ABORTED); | |
1172 | return 0; | |
1173 | } | |
1174 | ||
966c66e3 | 1175 | int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) { |
82bd6ddd LP |
1176 | int r; |
1177 | ||
1178 | assert(q); | |
1179 | assert(m); | |
1180 | ||
1181 | if (!q->bus_track) { | |
966c66e3 | 1182 | r = sd_bus_track_new(sd_bus_message_get_bus(m), &q->bus_track, on_bus_track, q); |
82bd6ddd LP |
1183 | if (r < 0) |
1184 | return r; | |
1185 | } | |
1186 | ||
1187 | r = sd_bus_track_add_sender(q->bus_track, m); | |
1188 | if (r < 0) | |
1189 | return r; | |
1190 | ||
1191 | return 0; | |
1192 | } |