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Commit | Line | Data |
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ec2c5e43 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2014 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
beef6a5f LP |
20 | #include <sd-messages.h> |
21 | ||
ec2c5e43 | 22 | #include "af-list.h" |
b5efdb8a | 23 | #include "alloc-util.h" |
f52e61da | 24 | #include "dns-domain.h" |
7cc6ed7b | 25 | #include "errno-list.h" |
3ffd4af2 LP |
26 | #include "fd-util.h" |
27 | #include "random-util.h" | |
7778dfff | 28 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
29 | #include "resolved-dns-transaction.h" |
30 | #include "resolved-llmnr.h" | |
8b43440b | 31 | #include "string-table.h" |
ec2c5e43 | 32 | |
b214dc0f LP |
33 | #define TRANSACTIONS_MAX 4096 |
34 | ||
c61d2b44 LP |
35 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
36 | assert(t); | |
37 | ||
38 | t->received = dns_packet_unref(t->received); | |
39 | t->answer = dns_answer_unref(t->answer); | |
40 | t->answer_rcode = 0; | |
41 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
42 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
43 | t->answer_authenticated = false; | |
d3760be0 | 44 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 45 | t->answer_errno = 0; |
c61d2b44 LP |
46 | } |
47 | ||
c5b4f861 LP |
48 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
49 | DnsTransaction *z; | |
50 | ||
51 | assert(t); | |
52 | ||
53 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
54 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 55 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
56 | dns_transaction_gc(z); |
57 | } | |
58 | } | |
59 | ||
f32f0e57 LP |
60 | static void dns_transaction_close_connection(DnsTransaction *t) { |
61 | assert(t); | |
62 | ||
63 | t->stream = dns_stream_free(t->stream); | |
64 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); | |
65 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
66 | } | |
67 | ||
f535705a | 68 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
69 | assert(t); |
70 | ||
71 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
72 | } |
73 | ||
ec2c5e43 | 74 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 75 | DnsQueryCandidate *c; |
ec2c5e43 | 76 | DnsZoneItem *i; |
547973de | 77 | DnsTransaction *z; |
ec2c5e43 LP |
78 | |
79 | if (!t) | |
80 | return NULL; | |
81 | ||
51e399bc LP |
82 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
83 | ||
f32f0e57 | 84 | dns_transaction_close_connection(t); |
f535705a | 85 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 86 | |
ec2c5e43 | 87 | dns_packet_unref(t->sent); |
c61d2b44 | 88 | dns_transaction_reset_answer(t); |
ec2c5e43 | 89 | |
8300ba21 | 90 | dns_server_unref(t->server); |
ec2c5e43 LP |
91 | |
92 | if (t->scope) { | |
f9ebb22a LP |
93 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
94 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
95 | |
96 | if (t->id != 0) | |
97 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
98 | } | |
99 | ||
547973de | 100 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 101 | set_remove(c->transactions, t); |
547973de | 102 | set_free(t->notify_query_candidates); |
801ad6a6 | 103 | |
35aa04e9 LP |
104 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
105 | set_remove(c->transactions, t); | |
106 | set_free(t->notify_query_candidates_done); | |
107 | ||
547973de | 108 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 109 | i->probe_transaction = NULL; |
547973de LP |
110 | set_free(t->notify_zone_items); |
111 | ||
35aa04e9 LP |
112 | while ((i = set_steal_first(t->notify_zone_items_done))) |
113 | i->probe_transaction = NULL; | |
114 | set_free(t->notify_zone_items_done); | |
115 | ||
547973de LP |
116 | while ((z = set_steal_first(t->notify_transactions))) |
117 | set_remove(z->dnssec_transactions, t); | |
118 | set_free(t->notify_transactions); | |
119 | ||
35aa04e9 LP |
120 | while ((z = set_steal_first(t->notify_transactions_done))) |
121 | set_remove(z->dnssec_transactions, t); | |
122 | set_free(t->notify_transactions_done); | |
123 | ||
c5b4f861 | 124 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
125 | set_free(t->dnssec_transactions); |
126 | ||
127 | dns_answer_unref(t->validated_keys); | |
97cc656c | 128 | dns_resource_key_unref(t->key); |
97cc656c | 129 | |
ec2c5e43 LP |
130 | free(t); |
131 | return NULL; | |
132 | } | |
133 | ||
134 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
135 | ||
51e399bc | 136 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
137 | assert(t); |
138 | ||
139 | if (t->block_gc > 0) | |
51e399bc | 140 | return true; |
ec2c5e43 | 141 | |
547973de | 142 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 143 | set_isempty(t->notify_query_candidates_done) && |
547973de | 144 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
145 | set_isempty(t->notify_zone_items_done) && |
146 | set_isempty(t->notify_transactions) && | |
147 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 148 | dns_transaction_free(t); |
51e399bc LP |
149 | return false; |
150 | } | |
151 | ||
152 | return true; | |
ec2c5e43 LP |
153 | } |
154 | ||
4dd15077 LP |
155 | static uint16_t pick_new_id(Manager *m) { |
156 | uint16_t new_id; | |
157 | ||
158 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
159 | * transactions, and it's much lower than the space of IDs. */ | |
160 | ||
161 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
162 | ||
163 | do | |
164 | random_bytes(&new_id, sizeof(new_id)); | |
165 | while (new_id == 0 || | |
166 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
167 | ||
168 | return new_id; | |
169 | } | |
170 | ||
f52e61da | 171 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
172 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
173 | int r; | |
174 | ||
175 | assert(ret); | |
176 | assert(s); | |
f52e61da | 177 | assert(key); |
ec2c5e43 | 178 | |
9eae2bf3 | 179 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 180 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 181 | return -EINVAL; |
d0129ddb LP |
182 | if (dns_type_is_obsolete(key->type)) |
183 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
184 | |
185 | /* We only support the IN class */ | |
c463eb78 | 186 | if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) |
9eae2bf3 LP |
187 | return -EOPNOTSUPP; |
188 | ||
b214dc0f LP |
189 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
190 | return -EBUSY; | |
191 | ||
d5099efc | 192 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
193 | if (r < 0) |
194 | return r; | |
195 | ||
f9ebb22a | 196 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
197 | if (r < 0) |
198 | return r; | |
199 | ||
ec2c5e43 LP |
200 | t = new0(DnsTransaction, 1); |
201 | if (!t) | |
202 | return -ENOMEM; | |
203 | ||
4667e00a | 204 | t->dns_udp_fd = -1; |
c3bc53e6 | 205 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 206 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 207 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 208 | t->key = dns_resource_key_ref(key); |
274b8748 | 209 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 210 | |
4dd15077 | 211 | t->id = pick_new_id(s->manager); |
ec2c5e43 LP |
212 | |
213 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
214 | if (r < 0) { | |
215 | t->id = 0; | |
216 | return r; | |
217 | } | |
218 | ||
f9ebb22a | 219 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
220 | if (r < 0) { |
221 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
222 | return r; | |
223 | } | |
224 | ||
f9ebb22a | 225 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
226 | t->scope = s; |
227 | ||
313cefa1 | 228 | s->manager->n_transactions_total++; |
a150ff5e | 229 | |
ec2c5e43 LP |
230 | if (ret) |
231 | *ret = t; | |
232 | ||
233 | t = NULL; | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
4dd15077 LP |
238 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
239 | uint16_t new_id; | |
240 | assert(t); | |
241 | ||
242 | /* Pick a new ID for this transaction. */ | |
243 | ||
244 | new_id = pick_new_id(t->scope->manager); | |
245 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
246 | ||
247 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
248 | t->id = new_id; | |
249 | ||
250 | /* Make sure we generate a new packet with the new ID */ | |
251 | t->sent = dns_packet_unref(t->sent); | |
252 | } | |
253 | ||
ec2c5e43 | 254 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 255 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 256 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 257 | DnsZoneItem *z; |
ec2c5e43 LP |
258 | |
259 | assert(t); | |
260 | assert(p); | |
261 | ||
262 | if (manager_our_packet(t->scope->manager, p) != 0) | |
263 | return; | |
264 | ||
164d025d | 265 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 266 | |
a5784c49 LP |
267 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
268 | t->id, | |
202b76ae | 269 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
270 | dns_protocol_to_string(t->scope->protocol), |
271 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 272 | af_to_name_short(t->scope->family), |
164d025d | 273 | strnull(pretty)); |
ec2c5e43 | 274 | |
a4076574 LP |
275 | /* RFC 4795, Section 4.1 says that the peer with the |
276 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
277 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
278 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
279 | return; |
280 | } | |
281 | ||
4d91eec4 | 282 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 283 | |
ec2c5e43 | 284 | t->block_gc++; |
35aa04e9 | 285 | |
547973de | 286 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
287 | /* First, make sure the zone item drops the reference |
288 | * to us */ | |
289 | dns_zone_item_probe_stop(z); | |
290 | ||
291 | /* Secondly, report this as conflict, so that we might | |
292 | * look for a different hostname */ | |
ec2c5e43 | 293 | dns_zone_item_conflict(z); |
3ef64445 | 294 | } |
ec2c5e43 LP |
295 | t->block_gc--; |
296 | ||
297 | dns_transaction_gc(t); | |
298 | } | |
299 | ||
300 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 301 | DnsQueryCandidate *c; |
ec2c5e43 | 302 | DnsZoneItem *z; |
547973de | 303 | DnsTransaction *d; |
7cc6ed7b | 304 | const char *st; |
202b76ae | 305 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
306 | |
307 | assert(t); | |
547973de | 308 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 309 | |
202b76ae ZJS |
310 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
311 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
312 | ||
f61dfddb | 313 | log_struct(LOG_NOTICE, |
beef6a5f | 314 | LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), |
202b76ae | 315 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 316 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 317 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 318 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
1e02e182 LP |
319 | "DNS_SERVER=%s", dns_server_string(t->server), |
320 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level), | |
f61dfddb | 321 | NULL); |
202b76ae | 322 | } |
f61dfddb | 323 | |
ec2c5e43 LP |
324 | /* Note that this call might invalidate the query. Callers |
325 | * should hence not attempt to access the query or transaction | |
326 | * after calling this function. */ | |
327 | ||
7cc6ed7b LP |
328 | if (state == DNS_TRANSACTION_ERRNO) |
329 | st = errno_to_name(t->answer_errno); | |
330 | else | |
331 | st = dns_transaction_state_to_string(state); | |
332 | ||
a5784c49 LP |
333 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
334 | t->id, | |
202b76ae | 335 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
336 | dns_protocol_to_string(t->scope->protocol), |
337 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 338 | af_to_name_short(t->scope->family), |
7cc6ed7b | 339 | st, |
a5784c49 LP |
340 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
341 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
342 | |
343 | t->state = state; | |
344 | ||
f32f0e57 | 345 | dns_transaction_close_connection(t); |
f535705a | 346 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
347 | |
348 | /* Notify all queries that are interested, but make sure the | |
349 | * transaction isn't freed while we are still looking at it */ | |
350 | t->block_gc++; | |
f7014757 | 351 | |
35aa04e9 | 352 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 353 | dns_query_candidate_notify(c); |
35aa04e9 | 354 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 355 | |
35aa04e9 LP |
356 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
357 | dns_zone_item_notify(z); | |
358 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
f7014757 | 359 | |
35aa04e9 LP |
360 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
361 | dns_transaction_notify(d, t); | |
362 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
363 | |
364 | t->block_gc--; | |
ec2c5e43 LP |
365 | dns_transaction_gc(t); |
366 | } | |
367 | ||
519ef046 LP |
368 | static int dns_transaction_pick_server(DnsTransaction *t) { |
369 | DnsServer *server; | |
370 | ||
371 | assert(t); | |
372 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
373 | ||
374 | server = dns_scope_get_dns_server(t->scope); | |
375 | if (!server) | |
376 | return -ESRCH; | |
377 | ||
274b8748 | 378 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 LP |
379 | |
380 | if (server == t->server) | |
381 | return 0; | |
382 | ||
383 | dns_server_unref(t->server); | |
384 | t->server = dns_server_ref(server); | |
385 | ||
386 | return 1; | |
387 | } | |
388 | ||
8d10d620 LP |
389 | static void dns_transaction_retry(DnsTransaction *t) { |
390 | int r; | |
391 | ||
392 | assert(t); | |
393 | ||
394 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
395 | ||
396 | /* Before we try again, switch to a new server. */ | |
397 | dns_scope_next_dns_server(t->scope); | |
398 | ||
399 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
400 | if (r < 0) { |
401 | t->answer_errno = -r; | |
402 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
403 | } | |
8d10d620 LP |
404 | } |
405 | ||
c02cf2f4 | 406 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
407 | int r; |
408 | ||
c02cf2f4 LP |
409 | assert(t); |
410 | ||
5278bbfe LP |
411 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
412 | ||
c02cf2f4 LP |
413 | if (!t->server) |
414 | return 0; | |
415 | ||
416 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
417 | return 0; | |
418 | ||
419 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
420 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
421 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
422 | OPT RR or DO bit. One of these cases is documented here, for example: | |
423 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
424 | ||
4dd15077 LP |
425 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
426 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
427 | |
428 | r = dns_transaction_go(t); | |
429 | if (r < 0) | |
430 | return r; | |
431 | ||
432 | return 1; | |
c02cf2f4 LP |
433 | } |
434 | ||
ec2c5e43 LP |
435 | static int on_stream_complete(DnsStream *s, int error) { |
436 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
437 | DnsTransaction *t; | |
438 | ||
439 | assert(s); | |
440 | assert(s->transaction); | |
441 | ||
442 | /* Copy the data we care about out of the stream before we | |
443 | * destroy it. */ | |
444 | t = s->transaction; | |
445 | p = dns_packet_ref(s->read_packet); | |
446 | ||
447 | t->stream = dns_stream_free(t->stream); | |
448 | ||
a1a3f73a LP |
449 | if (ERRNO_IS_DISCONNECT(error)) { |
450 | usec_t usec; | |
451 | ||
0791110f LP |
452 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
453 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
454 | * question on this scope. */ | |
455 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
456 | return 0; | |
457 | } | |
458 | ||
92ec902a | 459 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 460 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 461 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a LP |
462 | |
463 | dns_transaction_retry(t); | |
ac720200 LP |
464 | return 0; |
465 | } | |
ec2c5e43 | 466 | if (error != 0) { |
7cc6ed7b LP |
467 | t->answer_errno = error; |
468 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
469 | return 0; |
470 | } | |
471 | ||
a4076574 | 472 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 473 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
474 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
475 | return 0; | |
476 | } | |
477 | ||
478 | dns_scope_check_conflicts(t->scope, p); | |
479 | ||
ec2c5e43 LP |
480 | t->block_gc++; |
481 | dns_transaction_process_reply(t, p); | |
482 | t->block_gc--; | |
483 | ||
519ef046 LP |
484 | /* If the response wasn't useful, then complete the transition |
485 | * now. After all, we are the worst feature set now with TCP | |
486 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
487 | if (t->state == DNS_TRANSACTION_PENDING) |
488 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
489 | else |
490 | dns_transaction_gc(t); | |
ec2c5e43 LP |
491 | |
492 | return 0; | |
493 | } | |
494 | ||
495 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
496 | _cleanup_close_ int fd = -1; | |
497 | int r; | |
498 | ||
499 | assert(t); | |
500 | ||
519ef046 | 501 | dns_transaction_close_connection(t); |
ec2c5e43 | 502 | |
106784eb | 503 | switch (t->scope->protocol) { |
519ef046 | 504 | |
106784eb | 505 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
506 | r = dns_transaction_pick_server(t); |
507 | if (r < 0) | |
508 | return r; | |
509 | ||
92ec902a | 510 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
511 | return -EOPNOTSUPP; |
512 | ||
274b8748 | 513 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
514 | if (r < 0) |
515 | return r; | |
516 | ||
517 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 518 | break; |
ec2c5e43 | 519 | |
106784eb | 520 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 521 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 522 | if (t->received) |
519ef046 | 523 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
524 | else { |
525 | union in_addr_union address; | |
a7f7d1bd | 526 | int family = AF_UNSPEC; |
ec2c5e43 LP |
527 | |
528 | /* Otherwise, try to talk to the owner of a | |
529 | * the IP address, in case this is a reverse | |
530 | * PTR lookup */ | |
f52e61da | 531 | |
1c02e7ba | 532 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
533 | if (r < 0) |
534 | return r; | |
535 | if (r == 0) | |
536 | return -EINVAL; | |
9e08a6e0 | 537 | if (family != t->scope->family) |
9318cdd3 | 538 | return -ESRCH; |
ec2c5e43 | 539 | |
519ef046 | 540 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 541 | } |
106784eb DM |
542 | |
543 | break; | |
544 | ||
545 | default: | |
ec2c5e43 | 546 | return -EAFNOSUPPORT; |
106784eb | 547 | } |
ec2c5e43 LP |
548 | |
549 | if (fd < 0) | |
550 | return fd; | |
551 | ||
552 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
553 | if (r < 0) | |
554 | return r; | |
ec2c5e43 LP |
555 | fd = -1; |
556 | ||
557 | r = dns_stream_write_packet(t->stream, t->sent); | |
558 | if (r < 0) { | |
559 | t->stream = dns_stream_free(t->stream); | |
560 | return r; | |
561 | } | |
562 | ||
ec2c5e43 LP |
563 | t->stream->complete = on_stream_complete; |
564 | t->stream->transaction = t; | |
565 | ||
566 | /* The interface index is difficult to determine if we are | |
567 | * connecting to the local host, hence fill this in right away | |
568 | * instead of determining it from the socket */ | |
97ebebbc | 569 | t->stream->ifindex = dns_scope_ifindex(t->scope); |
ec2c5e43 | 570 | |
519ef046 LP |
571 | dns_transaction_reset_answer(t); |
572 | ||
cbe4216d LP |
573 | t->tried_stream = true; |
574 | ||
ec2c5e43 LP |
575 | return 0; |
576 | } | |
577 | ||
547973de | 578 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
579 | assert(t); |
580 | ||
581 | /* For mDNS we cache whenever we get the packet, rather than | |
582 | * in each transaction. */ | |
583 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
584 | return; | |
585 | ||
586 | /* We never cache if this packet is from the local host, under | |
587 | * the assumption that a locally running DNS server would | |
588 | * cache this anyway, and probably knows better when to flush | |
589 | * the cache then we could. */ | |
590 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
591 | return; | |
592 | ||
547973de LP |
593 | dns_cache_put(&t->scope->cache, |
594 | t->key, | |
595 | t->answer_rcode, | |
596 | t->answer, | |
547973de | 597 | t->answer_authenticated, |
d3760be0 | 598 | t->answer_nsec_ttl, |
547973de LP |
599 | 0, |
600 | t->received->family, | |
601 | &t->received->sender); | |
602 | } | |
603 | ||
105e1512 LP |
604 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
605 | DnsTransaction *dt; | |
606 | Iterator i; | |
607 | ||
608 | assert(t); | |
609 | ||
610 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
611 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
612 | return true; | |
613 | ||
614 | return false; | |
615 | } | |
616 | ||
942eb2e7 LP |
617 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
618 | DnsTransaction *dt; | |
619 | Iterator i; | |
620 | ||
621 | assert(t); | |
622 | ||
623 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
624 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
625 | ||
626 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
627 | ||
628 | switch (dt->state) { | |
629 | ||
630 | case DNS_TRANSACTION_NULL: | |
631 | case DNS_TRANSACTION_PENDING: | |
632 | case DNS_TRANSACTION_VALIDATING: | |
633 | /* Still ongoing */ | |
634 | return 0; | |
635 | ||
636 | case DNS_TRANSACTION_RCODE_FAILURE: | |
637 | if (dt->answer_rcode != DNS_RCODE_NXDOMAIN) { | |
638 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); | |
639 | goto fail; | |
640 | } | |
641 | ||
642 | /* Fall-through: NXDOMAIN is good enough for us. This is because some DNS servers erronously | |
643 | * return NXDOMAIN for empty non-terminals (Akamai...), and we need to handle that nicely, when | |
644 | * asking for parent SOA or similar RRs to make unsigned proofs. */ | |
645 | ||
646 | case DNS_TRANSACTION_SUCCESS: | |
647 | /* All good. */ | |
648 | break; | |
649 | ||
650 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
651 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
652 | * validationr result */ | |
653 | ||
654 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
655 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
656 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
657 | return 0; | |
658 | ||
659 | ||
660 | default: | |
661 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
662 | goto fail; | |
663 | } | |
664 | } | |
665 | ||
666 | /* All is ready, we can go and validate */ | |
667 | return 1; | |
668 | ||
669 | fail: | |
670 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
671 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
672 | return 0; | |
673 | } | |
674 | ||
547973de LP |
675 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
676 | int r; | |
677 | ||
678 | assert(t); | |
679 | ||
680 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 681 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
682 | if (r < 0) |
683 | goto fail; | |
942eb2e7 | 684 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
685 | return; |
686 | ||
c02cf2f4 LP |
687 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
688 | * restart the lookup immediately. */ | |
689 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
690 | if (r < 0) |
691 | goto fail; | |
c02cf2f4 LP |
692 | if (r > 0) /* Transaction got restarted... */ |
693 | return; | |
694 | ||
547973de LP |
695 | /* All our auxiliary DNSSEC transactions are complete now. Try |
696 | * to validate our RRset now. */ | |
697 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
698 | if (r == -EBADMSG) { |
699 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
700 | return; | |
701 | } | |
7cc6ed7b LP |
702 | if (r < 0) |
703 | goto fail; | |
547973de | 704 | |
b652d4a2 LP |
705 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
706 | t->scope->dnssec_mode == DNSSEC_YES) { | |
707 | /* We are not in automatic downgrade mode, and the | |
708 | * server is bad, refuse operation. */ | |
709 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
710 | return; | |
711 | } | |
712 | ||
019036a4 | 713 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
714 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
715 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
716 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
717 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
718 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
719 | return; | |
720 | } | |
721 | ||
1e02e182 LP |
722 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
723 | dns_server_warn_downgrade(t->server); | |
724 | ||
547973de LP |
725 | dns_transaction_cache_answer(t); |
726 | ||
727 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
728 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
729 | else | |
3bbdc31d | 730 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
731 | |
732 | return; | |
733 | ||
734 | fail: | |
735 | t->answer_errno = -r; | |
736 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
737 | } |
738 | ||
eac7cda2 LP |
739 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
740 | int r; | |
741 | ||
742 | assert(t); | |
743 | ||
744 | /* Checks whether the answer is positive, i.e. either a direct | |
745 | * answer to the question, or a CNAME/DNAME for it */ | |
746 | ||
747 | r = dns_answer_match_key(t->answer, t->key, flags); | |
748 | if (r != 0) | |
749 | return r; | |
750 | ||
751 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
752 | if (r != 0) | |
753 | return r; | |
754 | ||
755 | return false; | |
756 | } | |
757 | ||
758 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
759 | int r; | |
760 | ||
761 | assert(t); | |
762 | ||
763 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
764 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
765 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
766 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
767 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
768 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
769 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
770 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
771 | * incomplete CNAME/DNAME chain. | |
772 | * | |
773 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
774 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
775 | * lookup. */ | |
776 | ||
777 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
778 | return 0; | |
779 | ||
780 | r = dns_transaction_has_positive_answer(t, NULL); | |
781 | if (r <= 0) | |
782 | return r; | |
783 | ||
784 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
785 | return 0; | |
786 | } | |
787 | ||
ec2c5e43 | 788 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 789 | usec_t ts; |
ec2c5e43 LP |
790 | int r; |
791 | ||
792 | assert(t); | |
793 | assert(p); | |
9df3ba6c TG |
794 | assert(t->scope); |
795 | assert(t->scope->manager); | |
ec2c5e43 | 796 | |
5a7e41a3 LP |
797 | if (t->state != DNS_TRANSACTION_PENDING) |
798 | return; | |
799 | ||
ec2c5e43 LP |
800 | /* Note that this call might invalidate the query. Callers |
801 | * should hence not attempt to access the query or transaction | |
802 | * after calling this function. */ | |
803 | ||
b5efcf29 LP |
804 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
805 | ||
106784eb | 806 | switch (t->scope->protocol) { |
b5efcf29 | 807 | |
106784eb | 808 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 809 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 810 | |
97ebebbc | 811 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
812 | return; |
813 | ||
814 | if (p->family != t->scope->family) | |
815 | return; | |
816 | ||
817 | /* Tentative packets are not full responses but still | |
818 | * useful for identifying uniqueness conflicts during | |
819 | * probing. */ | |
8b757a38 | 820 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
821 | dns_transaction_tentative(t, p); |
822 | return; | |
823 | } | |
106784eb DM |
824 | |
825 | break; | |
826 | ||
4e5bf5e1 | 827 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 828 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
829 | |
830 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
831 | return; |
832 | ||
833 | if (p->family != t->scope->family) | |
834 | return; | |
835 | ||
836 | break; | |
837 | ||
106784eb | 838 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
839 | /* Note that we do not need to verify the |
840 | * addresses/port numbers of incoming traffic, as we | |
841 | * invoked connect() on our UDP socket in which case | |
842 | * the kernel already does the needed verification for | |
843 | * us. */ | |
106784eb DM |
844 | break; |
845 | ||
846 | default: | |
9c56a6f3 | 847 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
848 | } |
849 | ||
ec2c5e43 LP |
850 | if (t->received != p) { |
851 | dns_packet_unref(t->received); | |
852 | t->received = dns_packet_ref(p); | |
853 | } | |
854 | ||
c3bc53e6 LP |
855 | t->answer_source = DNS_TRANSACTION_NETWORK; |
856 | ||
ec2c5e43 LP |
857 | if (p->ipproto == IPPROTO_TCP) { |
858 | if (DNS_PACKET_TC(p)) { | |
859 | /* Truncated via TCP? Somebody must be fucking with us */ | |
860 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
861 | return; | |
862 | } | |
863 | ||
864 | if (DNS_PACKET_ID(p) != t->id) { | |
865 | /* Not the reply to our query? Somebody must be fucking with us */ | |
866 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
867 | return; | |
868 | } | |
869 | } | |
870 | ||
38a03f06 | 871 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
872 | |
873 | switch (t->scope->protocol) { | |
8af5b883 | 874 | |
9df3ba6c TG |
875 | case DNS_PROTOCOL_DNS: |
876 | assert(t->server); | |
877 | ||
4e0b8b17 TG |
878 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
879 | ||
8af5b883 | 880 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 TG |
881 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
882 | ||
274b8748 | 883 | dns_server_packet_failed(t->server, t->current_feature_level); |
8d10d620 | 884 | dns_transaction_retry(t); |
4e0b8b17 | 885 | return; |
6bb2c085 | 886 | } else if (DNS_PACKET_TC(p)) |
274b8748 | 887 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
888 | |
889 | break; | |
8af5b883 | 890 | |
9df3ba6c TG |
891 | case DNS_PROTOCOL_LLMNR: |
892 | case DNS_PROTOCOL_MDNS: | |
893 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 894 | break; |
8af5b883 | 895 | |
9df3ba6c | 896 | default: |
8af5b883 | 897 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
898 | } |
899 | ||
ec2c5e43 | 900 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
901 | |
902 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
903 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
904 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
905 | return; | |
906 | } | |
907 | ||
f757cd85 LP |
908 | log_debug("Reply truncated, retrying via TCP."); |
909 | ||
ec2c5e43 LP |
910 | /* Response was truncated, let's try again with good old TCP */ |
911 | r = dns_transaction_open_tcp(t); | |
912 | if (r == -ESRCH) { | |
913 | /* No servers found? Damn! */ | |
914 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
915 | return; | |
916 | } | |
91adc4db LP |
917 | if (r == -EOPNOTSUPP) { |
918 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
919 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
920 | return; | |
921 | } | |
ec2c5e43 | 922 | if (r < 0) { |
8af5b883 | 923 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 924 | * we immediately give up */ |
7cc6ed7b LP |
925 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
926 | goto fail; | |
ec2c5e43 LP |
927 | |
928 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
8d10d620 | 929 | dns_transaction_retry(t); |
ec2c5e43 | 930 | } |
2a6658ef LP |
931 | |
932 | return; | |
ec2c5e43 LP |
933 | } |
934 | ||
de54e62b | 935 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
936 | r = dns_packet_extract(p); |
937 | if (r < 0) { | |
938 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
939 | return; | |
940 | } | |
941 | ||
de54e62b | 942 | /* Report that the OPT RR was missing */ |
ed9717fc LP |
943 | if (t->server) { |
944 | if (!p->opt) | |
945 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
946 | ||
947 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); | |
948 | } | |
de54e62b | 949 | |
c02cf2f4 LP |
950 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
951 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
952 | if (r < 0) |
953 | goto fail; | |
c02cf2f4 LP |
954 | if (r > 0) /* Transaction got restarted... */ |
955 | return; | |
956 | ||
b5efcf29 LP |
957 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { |
958 | ||
547493c5 | 959 | /* Only consider responses with equivalent query section to the request */ |
8af5b883 | 960 | r = dns_packet_is_reply_for(p, t->key); |
7cc6ed7b LP |
961 | if (r < 0) |
962 | goto fail; | |
8af5b883 | 963 | if (r == 0) { |
547493c5 DM |
964 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
965 | return; | |
966 | } | |
29815b6c | 967 | |
547493c5 DM |
968 | /* Install the answer as answer to the transaction */ |
969 | dns_answer_unref(t->answer); | |
970 | t->answer = dns_answer_ref(p->answer); | |
971 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 972 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 973 | t->answer_authenticated = false; |
79e24931 | 974 | |
eac7cda2 LP |
975 | r = dns_transaction_fix_rcode(t); |
976 | if (r < 0) | |
977 | goto fail; | |
978 | ||
51e399bc LP |
979 | /* Block GC while starting requests for additional DNSSEC RRs */ |
980 | t->block_gc++; | |
547973de | 981 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
982 | t->block_gc--; |
983 | ||
984 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
985 | if (!dns_transaction_gc(t)) | |
986 | return; | |
987 | ||
988 | /* Requesting additional keys might have resulted in | |
989 | * this transaction to fail, since the auxiliary | |
990 | * request failed for some reason. If so, we are not | |
991 | * in pending state anymore, and we should exit | |
992 | * quickly. */ | |
993 | if (t->state != DNS_TRANSACTION_PENDING) | |
994 | return; | |
7cc6ed7b LP |
995 | if (r < 0) |
996 | goto fail; | |
547973de LP |
997 | if (r > 0) { |
998 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
999 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1000 | dns_transaction_close_connection(t); |
1001 | dns_transaction_stop_timeout(t); | |
547973de LP |
1002 | return; |
1003 | } | |
547493c5 | 1004 | } |
ec2c5e43 | 1005 | |
547973de | 1006 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1007 | return; |
1008 | ||
1009 | fail: | |
1010 | t->answer_errno = -r; | |
1011 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1012 | } |
1013 | ||
c19ffd9f TG |
1014 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1015 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1016 | DnsTransaction *t = userdata; | |
1017 | int r; | |
1018 | ||
1019 | assert(t); | |
1020 | assert(t->scope); | |
1021 | ||
1022 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1023 | if (ERRNO_IS_DISCONNECT(-r)) { |
1024 | usec_t usec; | |
c19ffd9f | 1025 | |
7e1851e3 LP |
1026 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1027 | * recvmsg(). Treat this like a lost packet. */ | |
1028 | ||
92ec902a | 1029 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1030 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1031 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 LP |
1032 | |
1033 | dns_transaction_retry(t); | |
1034 | return 0; | |
1035 | } | |
1036 | if (r < 0) { | |
7cc6ed7b LP |
1037 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1038 | t->answer_errno = -r; | |
7e1851e3 LP |
1039 | return 0; |
1040 | } | |
1041 | ||
1042 | r = dns_packet_validate_reply(p); | |
1043 | if (r < 0) { | |
1044 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1045 | return 0; | |
1046 | } | |
1047 | if (r == 0) { | |
e09f605e | 1048 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1049 | return 0; |
1050 | } | |
1051 | ||
1052 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1053 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1054 | return 0; |
1055 | } | |
c19ffd9f | 1056 | |
7e1851e3 | 1057 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1058 | return 0; |
1059 | } | |
1060 | ||
49cce12d | 1061 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1062 | int r; |
1063 | ||
1064 | assert(t); | |
c19ffd9f | 1065 | |
519ef046 | 1066 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1067 | |
519ef046 | 1068 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1069 | if (r < 0) |
1070 | return r; | |
c19ffd9f | 1071 | |
274b8748 | 1072 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
519ef046 LP |
1073 | return -EAGAIN; |
1074 | ||
92ec902a | 1075 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1076 | return -EOPNOTSUPP; |
1077 | ||
519ef046 LP |
1078 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1079 | int fd; | |
1080 | ||
1081 | dns_transaction_close_connection(t); | |
c19ffd9f | 1082 | |
519ef046 LP |
1083 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1084 | if (fd < 0) | |
1085 | return fd; | |
1086 | ||
1087 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1088 | if (r < 0) { | |
1089 | safe_close(fd); | |
1090 | return r; | |
1091 | } | |
1092 | ||
aa4a9deb | 1093 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1094 | t->dns_udp_fd = fd; |
1095 | } | |
1096 | ||
274b8748 | 1097 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1098 | if (r < 0) |
1099 | return r; | |
1100 | } else | |
1101 | dns_transaction_close_connection(t); | |
1102 | ||
1103 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1104 | if (r < 0) |
1105 | return r; | |
c19ffd9f | 1106 | |
519ef046 | 1107 | dns_transaction_reset_answer(t); |
be808ea0 | 1108 | |
471d40d9 | 1109 | return 0; |
c19ffd9f TG |
1110 | } |
1111 | ||
ec2c5e43 LP |
1112 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1113 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1114 | |
1115 | assert(s); | |
1116 | assert(t); | |
1117 | ||
ef7ce6df DM |
1118 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1119 | /* Timeout reached? Increase the timeout for the server used */ | |
1120 | switch (t->scope->protocol) { | |
49cce12d | 1121 | |
ef7ce6df DM |
1122 | case DNS_PROTOCOL_DNS: |
1123 | assert(t->server); | |
274b8748 | 1124 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1125 | break; |
49cce12d | 1126 | |
ef7ce6df DM |
1127 | case DNS_PROTOCOL_LLMNR: |
1128 | case DNS_PROTOCOL_MDNS: | |
1129 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1130 | break; |
49cce12d | 1131 | |
ef7ce6df DM |
1132 | default: |
1133 | assert_not_reached("Invalid DNS protocol."); | |
1134 | } | |
1135 | ||
1136 | if (t->initial_jitter_scheduled) | |
1137 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1138 | } |
1139 | ||
423659ab LP |
1140 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1141 | ||
8d10d620 | 1142 | dns_transaction_retry(t); |
ec2c5e43 LP |
1143 | return 0; |
1144 | } | |
1145 | ||
9df3ba6c TG |
1146 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1147 | assert(t); | |
1148 | assert(t->scope); | |
1149 | ||
1150 | switch (t->scope->protocol) { | |
49cce12d | 1151 | |
9df3ba6c TG |
1152 | case DNS_PROTOCOL_DNS: |
1153 | assert(t->server); | |
9df3ba6c | 1154 | return t->server->resend_timeout; |
49cce12d | 1155 | |
9df3ba6c | 1156 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
1157 | assert(t->n_attempts > 0); |
1158 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1159 | |
11a27c2e | 1160 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1161 | return t->scope->resend_timeout; |
49cce12d | 1162 | |
9df3ba6c TG |
1163 | default: |
1164 | assert_not_reached("Invalid DNS protocol."); | |
1165 | } | |
1166 | } | |
1167 | ||
c842ff24 | 1168 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1169 | int r; |
1170 | ||
1171 | assert(t); | |
1172 | ||
f535705a | 1173 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1174 | |
edbcc1fd LP |
1175 | r = dns_scope_network_good(t->scope); |
1176 | if (r < 0) | |
1177 | return r; | |
1178 | if (r == 0) { | |
1179 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1180 | return 0; | |
1181 | } | |
1182 | ||
ec2c5e43 LP |
1183 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1184 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1185 | return 0; | |
1186 | } | |
1187 | ||
cbe4216d | 1188 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1189 | /* If we already tried via a stream, then we don't |
1190 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1191 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1192 | return 0; | |
1193 | } | |
1194 | ||
1195 | t->n_attempts++; | |
9df3ba6c | 1196 | t->start_usec = ts; |
c61d2b44 LP |
1197 | |
1198 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1199 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1200 | |
0d2cd476 LP |
1201 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1202 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1203 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1204 | if (r < 0) |
1205 | return r; | |
1206 | if (r > 0) { | |
1207 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1208 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1209 | t->answer_authenticated = true; |
0d2cd476 LP |
1210 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1211 | return 0; | |
1212 | } | |
b2b796b8 | 1213 | |
1c02e7ba | 1214 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1215 | t->key->type == DNS_TYPE_DS) { |
1216 | ||
1217 | /* Hmm, this is a request for the root DS? A | |
1218 | * DS RR doesn't exist in the root zone, and | |
1219 | * if our trust anchor didn't know it either, | |
1220 | * this means we cannot do any DNSSEC logic | |
1221 | * anymore. */ | |
1222 | ||
1ed8c0fb | 1223 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1224 | /* We are in downgrade mode. In this |
1225 | * case, synthesize an unsigned empty | |
1226 | * response, so that the any lookup | |
1227 | * depending on this one can continue | |
1228 | * assuming there was no DS, and hence | |
1229 | * the root zone was unsigned. */ | |
1230 | ||
1231 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1232 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1233 | t->answer_authenticated = false; | |
1234 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1235 | } else | |
1236 | /* If we are not in downgrade mode, | |
1237 | * then fail the lookup, because we | |
1238 | * cannot reasonably answer it. There | |
1239 | * might be DS RRs, but we don't know | |
1240 | * them, and the DNS server won't tell | |
1241 | * them to us (and even if it would, | |
202b76ae | 1242 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1243 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1244 | ||
1245 | return 0; | |
1246 | } | |
0d2cd476 LP |
1247 | } |
1248 | ||
1249 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1250 | * for probing or verifying a zone item. */ |
547973de | 1251 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1252 | |
97ebebbc | 1253 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1254 | if (r < 0) |
1255 | return r; | |
1256 | if (r > 0) { | |
ae6a4bbf | 1257 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1258 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1259 | t->answer_authenticated = true; |
d746bb3e LP |
1260 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1261 | return 0; | |
1262 | } | |
1263 | } | |
1264 | ||
4d926a69 LP |
1265 | /* Check the cache, but only if this transaction is not used |
1266 | * for probing or verifying a zone item. */ | |
547973de | 1267 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1268 | |
4d926a69 LP |
1269 | /* Before trying the cache, let's make sure we figured out a |
1270 | * server to use. Should this cause a change of server this | |
1271 | * might flush the cache. */ | |
1272 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 1273 | |
4d926a69 LP |
1274 | /* Let's then prune all outdated entries */ |
1275 | dns_cache_prune(&t->scope->cache); | |
1276 | ||
17c8de63 | 1277 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1278 | if (r < 0) |
1279 | return r; | |
1280 | if (r > 0) { | |
c3bc53e6 | 1281 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1282 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1283 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1284 | else | |
3bbdc31d | 1285 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1286 | return 0; |
1287 | } | |
ec2c5e43 LP |
1288 | } |
1289 | ||
1effe965 DM |
1290 | return 1; |
1291 | } | |
1292 | ||
0afa57e2 DM |
1293 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1294 | ||
1295 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1296 | bool add_known_answers = false; |
0afa57e2 DM |
1297 | DnsTransaction *other; |
1298 | unsigned qdcount; | |
1299 | usec_t ts; | |
1300 | int r; | |
1301 | ||
1302 | assert(t); | |
1303 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1304 | ||
e5abebab | 1305 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1306 | t->sent = dns_packet_unref(t->sent); |
1307 | ||
1308 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1309 | if (r < 0) | |
1310 | return r; | |
1311 | ||
1312 | r = dns_packet_append_key(p, t->key, NULL); | |
1313 | if (r < 0) | |
1314 | return r; | |
1315 | ||
1316 | qdcount = 1; | |
1317 | ||
7778dfff DM |
1318 | if (dns_key_is_shared(t->key)) |
1319 | add_known_answers = true; | |
1320 | ||
0afa57e2 DM |
1321 | /* |
1322 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1323 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1324 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1325 | */ | |
1326 | ||
1327 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1328 | ||
1329 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1330 | ||
1331 | /* Skip ourselves */ | |
1332 | if (other == t) | |
1333 | continue; | |
1334 | ||
1335 | if (other->state != DNS_TRANSACTION_PENDING) | |
1336 | continue; | |
1337 | ||
1338 | if (other->next_attempt_after > ts) | |
1339 | continue; | |
1340 | ||
1341 | if (qdcount >= UINT16_MAX) | |
1342 | break; | |
1343 | ||
1344 | r = dns_packet_append_key(p, other->key, NULL); | |
1345 | ||
1346 | /* | |
1347 | * If we can't stuff more questions into the packet, just give up. | |
1348 | * One of the 'other' transactions will fire later and take care of the rest. | |
1349 | */ | |
1350 | if (r == -EMSGSIZE) | |
1351 | break; | |
1352 | ||
1353 | if (r < 0) | |
1354 | return r; | |
1355 | ||
c842ff24 | 1356 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1357 | if (r <= 0) |
1358 | continue; | |
1359 | ||
1360 | ts += transaction_get_resend_timeout(other); | |
1361 | ||
1362 | r = sd_event_add_time( | |
1363 | other->scope->manager->event, | |
1364 | &other->timeout_event_source, | |
1365 | clock_boottime_or_monotonic(), | |
1366 | ts, 0, | |
1367 | on_transaction_timeout, other); | |
1368 | if (r < 0) | |
1369 | return r; | |
1370 | ||
aa4a9deb LP |
1371 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1372 | ||
0afa57e2 DM |
1373 | other->state = DNS_TRANSACTION_PENDING; |
1374 | other->next_attempt_after = ts; | |
1375 | ||
313cefa1 | 1376 | qdcount++; |
7778dfff DM |
1377 | |
1378 | if (dns_key_is_shared(other->key)) | |
1379 | add_known_answers = true; | |
0afa57e2 DM |
1380 | } |
1381 | ||
1382 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1383 | |
7778dfff DM |
1384 | /* Append known answer section if we're asking for any shared record */ |
1385 | if (add_known_answers) { | |
1386 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1387 | if (r < 0) | |
1388 | return r; | |
1389 | } | |
1390 | ||
0afa57e2 DM |
1391 | t->sent = p; |
1392 | p = NULL; | |
1393 | ||
1394 | return 0; | |
1395 | } | |
1396 | ||
1397 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1398 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1399 | int r; | |
1400 | ||
1401 | assert(t); | |
1402 | ||
1403 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1404 | return dns_transaction_make_packet_mdns(t); | |
1405 | ||
1406 | if (t->sent) | |
1407 | return 0; | |
1408 | ||
b652d4a2 | 1409 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1410 | if (r < 0) |
1411 | return r; | |
1412 | ||
0afa57e2 DM |
1413 | r = dns_packet_append_key(p, t->key, NULL); |
1414 | if (r < 0) | |
1415 | return r; | |
1416 | ||
1417 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1418 | DNS_PACKET_HEADER(p)->id = t->id; | |
1419 | ||
1420 | t->sent = p; | |
1421 | p = NULL; | |
1422 | ||
1423 | return 0; | |
1424 | } | |
1425 | ||
1effe965 DM |
1426 | int dns_transaction_go(DnsTransaction *t) { |
1427 | usec_t ts; | |
1428 | int r; | |
202b76ae | 1429 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1430 | |
1431 | assert(t); | |
1432 | ||
5278bbfe LP |
1433 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1434 | * now. */ | |
1435 | ||
1effe965 | 1436 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1437 | |
c842ff24 | 1438 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1439 | if (r <= 0) |
1440 | return r; | |
1441 | ||
202b76ae | 1442 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1443 | t->id, |
202b76ae | 1444 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1445 | dns_protocol_to_string(t->scope->protocol), |
1446 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1447 | af_to_name_short(t->scope->family)); |
1effe965 | 1448 | |
ef7ce6df | 1449 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1450 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1451 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1452 | usec_t jitter, accuracy; | |
6e068472 LP |
1453 | |
1454 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1455 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1456 | ||
ef7ce6df | 1457 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1458 | |
1459 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1460 | |
1461 | switch (t->scope->protocol) { | |
519ef046 | 1462 | |
ea12bcc7 DM |
1463 | case DNS_PROTOCOL_LLMNR: |
1464 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1465 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1466 | break; | |
519ef046 | 1467 | |
ea12bcc7 DM |
1468 | case DNS_PROTOCOL_MDNS: |
1469 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1470 | jitter += MDNS_JITTER_MIN_USEC; | |
1471 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1472 | break; | |
1473 | default: | |
1474 | assert_not_reached("bad protocol"); | |
1475 | } | |
6e068472 LP |
1476 | |
1477 | r = sd_event_add_time( | |
1478 | t->scope->manager->event, | |
1479 | &t->timeout_event_source, | |
1480 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1481 | ts + jitter, accuracy, |
6e068472 LP |
1482 | on_transaction_timeout, t); |
1483 | if (r < 0) | |
1484 | return r; | |
1485 | ||
aa4a9deb LP |
1486 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1487 | ||
6e068472 | 1488 | t->n_attempts = 0; |
a9da14e1 | 1489 | t->next_attempt_after = ts; |
6e068472 LP |
1490 | t->state = DNS_TRANSACTION_PENDING; |
1491 | ||
ea12bcc7 | 1492 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1493 | return 0; |
1494 | } | |
1495 | ||
ec2c5e43 LP |
1496 | /* Otherwise, we need to ask the network */ |
1497 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1498 | if (r < 0) |
1499 | return r; | |
1500 | ||
1501 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1502 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1503 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1504 | |
1505 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1506 | * always be made via TCP on LLMNR */ | |
1507 | r = dns_transaction_open_tcp(t); | |
1508 | } else { | |
be808ea0 TG |
1509 | /* Try via UDP, and if that fails due to large size or lack of |
1510 | * support try via TCP */ | |
49cce12d | 1511 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1512 | if (r == -EMSGSIZE) |
1513 | log_debug("Sending query via TCP since it is too large."); | |
034e8031 LP |
1514 | if (r == -EAGAIN) |
1515 | log_debug("Sending query via TCP since server doesn't support UDP."); | |
be808ea0 | 1516 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1517 | r = dns_transaction_open_tcp(t); |
1518 | } | |
be808ea0 | 1519 | |
ec2c5e43 LP |
1520 | if (r == -ESRCH) { |
1521 | /* No servers to send this to? */ | |
1522 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1523 | return 0; | |
91adc4db LP |
1524 | } |
1525 | if (r == -EOPNOTSUPP) { | |
1526 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1527 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1528 | return 0; | |
1529 | } | |
0791110f | 1530 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1531 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1532 | * answer this request with this protocol. */ |
1533 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1534 | return 0; | |
1535 | } | |
91adc4db | 1536 | if (r < 0) { |
7cc6ed7b LP |
1537 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1538 | return r; | |
13b551ac | 1539 | |
ec2c5e43 | 1540 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1541 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1542 | |
1543 | return dns_transaction_go(t); | |
1544 | } | |
1545 | ||
a9da14e1 DM |
1546 | ts += transaction_get_resend_timeout(t); |
1547 | ||
9a015429 LP |
1548 | r = sd_event_add_time( |
1549 | t->scope->manager->event, | |
1550 | &t->timeout_event_source, | |
1551 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1552 | ts, 0, |
9a015429 | 1553 | on_transaction_timeout, t); |
ec2c5e43 LP |
1554 | if (r < 0) |
1555 | return r; | |
1556 | ||
aa4a9deb LP |
1557 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1558 | ||
ec2c5e43 | 1559 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1560 | t->next_attempt_after = ts; |
1561 | ||
ec2c5e43 LP |
1562 | return 1; |
1563 | } | |
1564 | ||
f2992dc1 LP |
1565 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1566 | DnsTransaction *n; | |
1567 | Iterator i; | |
1568 | int r; | |
1569 | ||
1570 | assert(t); | |
1571 | assert(aux); | |
1572 | ||
1573 | /* Try to find cyclic dependencies between transaction objects */ | |
1574 | ||
1575 | if (t == aux) | |
1576 | return 1; | |
1577 | ||
3eb6aa00 | 1578 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1579 | r = dns_transaction_find_cyclic(t, n); |
1580 | if (r != 0) | |
1581 | return r; | |
1582 | } | |
1583 | ||
3eb6aa00 | 1584 | return 0; |
f2992dc1 LP |
1585 | } |
1586 | ||
547973de LP |
1587 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1588 | DnsTransaction *aux; | |
1589 | int r; | |
1590 | ||
1591 | assert(t); | |
1592 | assert(ret); | |
1593 | assert(key); | |
1594 | ||
1595 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1596 | if (!aux) { | |
1597 | r = dns_transaction_new(&aux, t->scope, key); | |
1598 | if (r < 0) | |
1599 | return r; | |
1600 | } else { | |
1601 | if (set_contains(t->dnssec_transactions, aux)) { | |
1602 | *ret = aux; | |
1603 | return 0; | |
1604 | } | |
f2992dc1 LP |
1605 | |
1606 | r = dns_transaction_find_cyclic(t, aux); | |
1607 | if (r < 0) | |
1608 | return r; | |
1609 | if (r > 0) { | |
202b76ae ZJS |
1610 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1611 | ||
1612 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1613 | aux->id, |
202b76ae | 1614 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1615 | t->id, |
202b76ae ZJS |
1616 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1617 | ||
f2992dc1 LP |
1618 | return -ELOOP; |
1619 | } | |
547973de LP |
1620 | } |
1621 | ||
1622 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1623 | if (r < 0) | |
1624 | goto gc; | |
1625 | ||
1626 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1627 | if (r < 0) | |
35aa04e9 LP |
1628 | goto gc; |
1629 | ||
1630 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1631 | if (r < 0) | |
547973de LP |
1632 | goto gc; |
1633 | ||
1634 | r = set_put(t->dnssec_transactions, aux); | |
1635 | if (r < 0) | |
1636 | goto gc; | |
1637 | ||
1638 | r = set_put(aux->notify_transactions, t); | |
1639 | if (r < 0) { | |
1640 | (void) set_remove(t->dnssec_transactions, aux); | |
1641 | goto gc; | |
1642 | } | |
1643 | ||
1644 | *ret = aux; | |
1645 | return 1; | |
1646 | ||
1647 | gc: | |
1648 | dns_transaction_gc(aux); | |
1649 | return r; | |
1650 | } | |
1651 | ||
1652 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1653 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1654 | DnsTransaction *aux; | |
1655 | int r; | |
1656 | ||
1657 | assert(t); | |
1658 | assert(key); | |
1659 | ||
1660 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1661 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1662 | if (r < 0) |
1663 | return r; | |
1664 | if (r > 0) { | |
1665 | r = dns_answer_extend(&t->validated_keys, a); | |
1666 | if (r < 0) | |
1667 | return r; | |
1668 | ||
1669 | return 0; | |
1670 | } | |
1671 | ||
1672 | /* This didn't work, ask for it via the network/cache then. */ | |
1673 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1674 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1675 | return 0; | |
547973de LP |
1676 | if (r < 0) |
1677 | return r; | |
1678 | ||
1679 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1680 | r = dns_transaction_go(aux); | |
1681 | if (r < 0) | |
1682 | return r; | |
1683 | } | |
1684 | ||
f2992dc1 | 1685 | return 1; |
547973de LP |
1686 | } |
1687 | ||
8a516214 LP |
1688 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1689 | int r; | |
1690 | ||
1691 | assert(t); | |
1692 | ||
c629ff58 | 1693 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1694 | * database, either in the global one, or the link-local |
1695 | * one. */ | |
1696 | ||
1697 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1698 | if (r != 0) | |
1699 | return r; | |
1700 | ||
1701 | if (!t->scope->link) | |
1702 | return 0; | |
1703 | ||
1704 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1705 | } | |
1706 | ||
105e1512 LP |
1707 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1708 | int r; | |
1709 | ||
1710 | assert(t); | |
1711 | ||
1712 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1713 | * RRs to prove it */ | |
1714 | ||
1715 | r = dns_transaction_has_positive_answer(t, NULL); | |
1716 | if (r < 0) | |
1717 | return r; | |
1718 | if (r > 0) | |
1719 | return false; | |
1720 | ||
8e54f5d9 LP |
1721 | /* Is this key explicitly listed as a negative trust anchor? |
1722 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1723 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1724 | if (r < 0) |
1725 | return r; | |
1726 | if (r > 0) | |
1727 | return false; | |
1728 | ||
105e1512 LP |
1729 | /* The answer does not contain any RRs that match to the |
1730 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1731 | * included. If not, the answer is unsigned. */ | |
1732 | ||
1733 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1734 | if (r < 0) | |
1735 | return r; | |
1736 | if (r > 0) | |
1737 | return false; | |
1738 | ||
1739 | return true; | |
1740 | } | |
1741 | ||
1742 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1743 | int r; | |
1744 | ||
1745 | assert(t); | |
1746 | assert(rr); | |
1747 | ||
1748 | /* Check if the specified RR is the "primary" response, | |
1749 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1750 | * CNAME/DNAME for it. */ |
105e1512 LP |
1751 | |
1752 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1753 | if (r != 0) | |
1754 | return r; | |
1755 | ||
4cb94977 | 1756 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1757 | } |
1758 | ||
92ec902a LP |
1759 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1760 | assert(t); | |
1761 | ||
1762 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1763 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1764 | ||
1765 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1766 | return false; | |
1767 | ||
1768 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1769 | * be supported, hence return true. */ | |
1770 | if (!t->server) | |
1771 | return true; | |
1772 | ||
274b8748 | 1773 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_DO) |
92ec902a LP |
1774 | return false; |
1775 | ||
1776 | return dns_server_dnssec_supported(t->server); | |
1777 | } | |
1778 | ||
1779 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1780 | DnsTransaction *dt; | |
1781 | Iterator i; | |
1782 | ||
1783 | assert(t); | |
1784 | ||
1785 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1786 | ||
1787 | if (!dns_transaction_dnssec_supported(t)) | |
1788 | return false; | |
1789 | ||
1790 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1791 | if (!dns_transaction_dnssec_supported(dt)) | |
1792 | return false; | |
1793 | ||
1794 | return true; | |
1795 | } | |
1796 | ||
547973de LP |
1797 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1798 | DnsResourceRecord *rr; | |
105e1512 | 1799 | |
547973de LP |
1800 | int r; |
1801 | ||
1802 | assert(t); | |
1803 | ||
105e1512 LP |
1804 | /* |
1805 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1806 | * we can verify signatures or prove that RRs are rightfully | |
1807 | * unsigned. Specifically: | |
1808 | * | |
1809 | * - For RRSIG we get the matching DNSKEY | |
1810 | * - For DNSKEY we get the matching DS | |
1811 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1812 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 1813 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
1814 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
1815 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
1816 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
1817 | */ | |
1818 | ||
b652d4a2 | 1819 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1820 | return 0; |
92ec902a LP |
1821 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1822 | return 0; /* We only need to validate stuff from the network */ | |
1823 | if (!dns_transaction_dnssec_supported(t)) | |
1824 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1825 | |
547973de LP |
1826 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1827 | ||
105e1512 LP |
1828 | if (dns_type_is_pseudo(rr->key->type)) |
1829 | continue; | |
1830 | ||
8e54f5d9 | 1831 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 1832 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
1833 | if (r < 0) |
1834 | return r; | |
1835 | if (r > 0) | |
1836 | continue; | |
1837 | ||
547973de LP |
1838 | switch (rr->key->type) { |
1839 | ||
1840 | case DNS_TYPE_RRSIG: { | |
1841 | /* For each RRSIG we request the matching DNSKEY */ | |
1842 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1843 | ||
1844 | /* If this RRSIG is about a DNSKEY RR and the | |
1845 | * signer is the same as the owner, then we | |
1846 | * already have the DNSKEY, and we don't have | |
1847 | * to look for more. */ | |
1848 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 1849 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
1850 | if (r < 0) |
1851 | return r; | |
1852 | if (r > 0) | |
1853 | continue; | |
1854 | } | |
1855 | ||
105e1512 LP |
1856 | /* If the signer is not a parent of our |
1857 | * original query, then this is about an | |
1858 | * auxiliary RRset, but not anything we asked | |
1859 | * for. In this case we aren't interested, | |
1860 | * because we don't want to request additional | |
1861 | * RRs for stuff we didn't really ask for, and | |
1862 | * also to avoid request loops, where | |
1863 | * additional RRs from one transaction result | |
1864 | * in another transaction whose additonal RRs | |
1865 | * point back to the original transaction, and | |
1866 | * we deadlock. */ | |
1c02e7ba | 1867 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
1868 | if (r < 0) |
1869 | return r; | |
1870 | if (r == 0) | |
1871 | continue; | |
1872 | ||
1873 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1874 | if (!dnskey) | |
1875 | return -ENOMEM; | |
1876 | ||
1c02e7ba ZJS |
1877 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
1878 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
1879 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1880 | if (r < 0) | |
1881 | return r; | |
1882 | break; | |
1883 | } | |
1884 | ||
1885 | case DNS_TYPE_DNSKEY: { | |
1886 | /* For each DNSKEY we request the matching DS */ | |
1887 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1888 | ||
105e1512 LP |
1889 | /* If the DNSKEY we are looking at is not for |
1890 | * zone we are interested in, nor any of its | |
1891 | * parents, we aren't interested, and don't | |
1892 | * request it. After all, we don't want to end | |
1893 | * up in request loops, and want to keep | |
1894 | * additional traffic down. */ | |
1895 | ||
1c02e7ba | 1896 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
1897 | if (r < 0) |
1898 | return r; | |
1899 | if (r == 0) | |
1900 | continue; | |
1901 | ||
1c02e7ba | 1902 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
1903 | if (!ds) |
1904 | return -ENOMEM; | |
1905 | ||
1c02e7ba ZJS |
1906 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
1907 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
1908 | r = dns_transaction_request_dnssec_rr(t, ds); |
1909 | if (r < 0) | |
1910 | return r; | |
547973de | 1911 | |
105e1512 LP |
1912 | break; |
1913 | } | |
1914 | ||
105e1512 LP |
1915 | case DNS_TYPE_SOA: |
1916 | case DNS_TYPE_NS: { | |
1917 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1918 | ||
1919 | /* For an unsigned SOA or NS, try to acquire | |
1920 | * the matching DS RR, as we are at a zone cut | |
1921 | * then, and whether a DS exists tells us | |
1922 | * whether the zone is signed. Do so only if | |
1923 | * this RR matches our original question, | |
1924 | * however. */ | |
1925 | ||
1926 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1927 | if (r < 0) | |
1928 | return r; | |
1929 | if (r == 0) | |
1930 | continue; | |
1931 | ||
1932 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1933 | if (r < 0) | |
1934 | return r; | |
1935 | if (r > 0) | |
1936 | continue; | |
1937 | ||
1c02e7ba | 1938 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
1939 | if (!ds) |
1940 | return -ENOMEM; | |
1941 | ||
1c02e7ba ZJS |
1942 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
1943 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
1944 | r = dns_transaction_request_dnssec_rr(t, ds); |
1945 | if (r < 0) | |
1946 | return r; | |
1947 | ||
1948 | break; | |
105e1512 LP |
1949 | } |
1950 | ||
b63fca62 | 1951 | case DNS_TYPE_DS: |
105e1512 LP |
1952 | case DNS_TYPE_CNAME: |
1953 | case DNS_TYPE_DNAME: { | |
1954 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1955 | const char *name; | |
1956 | ||
1957 | /* CNAMEs and DNAMEs cannot be located at a | |
1958 | * zone apex, hence ask for the parent SOA for | |
1959 | * unsigned CNAME/DNAME RRs, maybe that's the | |
1960 | * apex. But do all that only if this is | |
1961 | * actually a response to our original | |
b63fca62 LP |
1962 | * question. |
1963 | * | |
1964 | * Similar for DS RRs, which are signed when | |
1965 | * the parent SOA is signed. */ | |
105e1512 LP |
1966 | |
1967 | r = dns_transaction_is_primary_response(t, rr); | |
1968 | if (r < 0) | |
1969 | return r; | |
1970 | if (r == 0) | |
1971 | continue; | |
1972 | ||
1973 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1974 | if (r < 0) | |
1975 | return r; | |
1976 | if (r > 0) | |
1977 | continue; | |
1978 | ||
43e6779a LP |
1979 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
1980 | if (r < 0) | |
1981 | return r; | |
1982 | if (r > 0) | |
1983 | continue; | |
1984 | ||
1c02e7ba | 1985 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
1986 | r = dns_name_parent(&name); |
1987 | if (r < 0) | |
1988 | return r; | |
1989 | if (r == 0) | |
1990 | continue; | |
1991 | ||
1992 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
1993 | if (!soa) | |
1994 | return -ENOMEM; | |
1995 | ||
1c02e7ba ZJS |
1996 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
1997 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
1998 | r = dns_transaction_request_dnssec_rr(t, soa); |
1999 | if (r < 0) | |
2000 | return r; | |
2001 | ||
2002 | break; | |
2003 | } | |
2004 | ||
2005 | default: { | |
2006 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2007 | ||
b63fca62 LP |
2008 | /* For other unsigned RRsets (including |
2009 | * NSEC/NSEC3!), look for proof the zone is | |
2010 | * unsigned, by requesting the SOA RR of the | |
2011 | * zone. However, do so only if they are | |
2012 | * directly relevant to our original | |
105e1512 LP |
2013 | * question. */ |
2014 | ||
2015 | r = dns_transaction_is_primary_response(t, rr); | |
2016 | if (r < 0) | |
2017 | return r; | |
2018 | if (r == 0) | |
2019 | continue; | |
2020 | ||
2021 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2022 | if (r < 0) | |
2023 | return r; | |
2024 | if (r > 0) | |
2025 | continue; | |
2026 | ||
1c02e7ba | 2027 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2028 | if (!soa) |
2029 | return -ENOMEM; | |
2030 | ||
1c02e7ba ZJS |
2031 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2032 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2033 | r = dns_transaction_request_dnssec_rr(t, soa); |
2034 | if (r < 0) | |
2035 | return r; | |
2036 | break; | |
547973de LP |
2037 | }} |
2038 | } | |
2039 | ||
105e1512 LP |
2040 | /* Above, we requested everything necessary to validate what |
2041 | * we got. Now, let's request what we need to validate what we | |
2042 | * didn't get... */ | |
2043 | ||
2044 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2045 | if (r < 0) | |
2046 | return r; | |
2047 | if (r > 0) { | |
2048 | const char *name; | |
4bbc06cc | 2049 | uint16_t type = 0; |
105e1512 | 2050 | |
1c02e7ba | 2051 | name = dns_resource_key_name(t->key); |
105e1512 | 2052 | |
4bbc06cc LP |
2053 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2054 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2055 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2056 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2057 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2058 | * to see if that is signed. */ | |
105e1512 | 2059 | |
4bbc06cc | 2060 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2061 | r = dns_name_parent(&name); |
4bbc06cc LP |
2062 | if (r > 0) { |
2063 | type = DNS_TYPE_SOA; | |
2064 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2065 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2066 | } else |
105e1512 | 2067 | name = NULL; |
4bbc06cc LP |
2068 | |
2069 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2070 | ||
2071 | type = DNS_TYPE_DS; | |
2072 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2073 | t->id, dns_resource_key_name(t->key)); | |
2074 | ||
2075 | } else { | |
2076 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2077 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2078 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2079 | } |
105e1512 LP |
2080 | |
2081 | if (name) { | |
2082 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2083 | ||
4bbc06cc | 2084 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2085 | if (!soa) |
2086 | return -ENOMEM; | |
2087 | ||
2088 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2089 | if (r < 0) | |
2090 | return r; | |
2091 | } | |
2092 | } | |
2093 | ||
2094 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2095 | } |
2096 | ||
2097 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2098 | assert(t); |
547973de LP |
2099 | assert(source); |
2100 | ||
942eb2e7 LP |
2101 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2102 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2103 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2104 | |
942eb2e7 LP |
2105 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2106 | dns_transaction_process_dnssec(t); | |
547973de LP |
2107 | } |
2108 | ||
105e1512 LP |
2109 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2110 | DnsResourceRecord *rr; | |
2111 | int ifindex, r; | |
2112 | ||
2113 | assert(t); | |
2114 | ||
2115 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2116 | * RRs from the list of validated keys to the list of | |
2117 | * validated keys. */ | |
2118 | ||
2119 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2120 | ||
96bb7673 | 2121 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2122 | if (r < 0) |
2123 | return r; | |
2124 | if (r == 0) | |
2125 | continue; | |
2126 | ||
2127 | /* If so, the DNSKEY is validated too. */ | |
2128 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2129 | if (r < 0) | |
2130 | return r; | |
2131 | } | |
2132 | ||
2133 | return 0; | |
2134 | } | |
2135 | ||
2136 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2137 | int r; |
2138 | ||
2139 | assert(t); | |
2140 | assert(rr); | |
2141 | ||
105e1512 LP |
2142 | /* Checks if the RR we are looking for must be signed with an |
2143 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2144 | |
b652d4a2 | 2145 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2146 | return false; |
56352fe9 | 2147 | |
105e1512 LP |
2148 | if (dns_type_is_pseudo(rr->key->type)) |
2149 | return -EINVAL; | |
56352fe9 | 2150 | |
1c02e7ba | 2151 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2152 | if (r < 0) |
2153 | return r; | |
2154 | if (r > 0) | |
2155 | return false; | |
2156 | ||
105e1512 | 2157 | switch (rr->key->type) { |
56352fe9 | 2158 | |
105e1512 LP |
2159 | case DNS_TYPE_RRSIG: |
2160 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2161 | return false; | |
2162 | ||
2163 | case DNS_TYPE_SOA: | |
2164 | case DNS_TYPE_NS: { | |
2165 | DnsTransaction *dt; | |
2166 | Iterator i; | |
2167 | ||
b63fca62 | 2168 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2169 | |
2170 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2171 | ||
2172 | if (dt->key->class != rr->key->class) | |
2173 | continue; | |
2174 | if (dt->key->type != DNS_TYPE_DS) | |
2175 | continue; | |
2176 | ||
1c02e7ba | 2177 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2178 | if (r < 0) |
2179 | return r; | |
2180 | if (r == 0) | |
2181 | continue; | |
2182 | ||
2183 | /* We found a DS transactions for the SOA/NS | |
2184 | * RRs we are looking at. If it discovered signed DS | |
2185 | * RRs, then we need to be signed, too. */ | |
2186 | ||
097a2517 TA |
2187 | if (!dt->answer_authenticated) |
2188 | return false; | |
105e1512 | 2189 | |
097a2517 | 2190 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2191 | } |
2192 | ||
2193 | /* We found nothing that proves this is safe to leave | |
2194 | * this unauthenticated, hence ask inist on | |
2195 | * authentication. */ | |
2196 | return true; | |
2197 | } | |
2198 | ||
b63fca62 | 2199 | case DNS_TYPE_DS: |
105e1512 LP |
2200 | case DNS_TYPE_CNAME: |
2201 | case DNS_TYPE_DNAME: { | |
2202 | const char *parent = NULL; | |
2203 | DnsTransaction *dt; | |
2204 | Iterator i; | |
2205 | ||
b63fca62 LP |
2206 | /* |
2207 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2208 | * | |
2209 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2210 | */ | |
105e1512 LP |
2211 | |
2212 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2213 | ||
2214 | if (dt->key->class != rr->key->class) | |
2215 | continue; | |
2216 | if (dt->key->type != DNS_TYPE_SOA) | |
2217 | continue; | |
2218 | ||
2219 | if (!parent) { | |
1c02e7ba | 2220 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2221 | r = dns_name_parent(&parent); |
2222 | if (r < 0) | |
2223 | return r; | |
2224 | if (r == 0) { | |
b63fca62 LP |
2225 | if (rr->key->type == DNS_TYPE_DS) |
2226 | return true; | |
2227 | ||
105e1512 LP |
2228 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2229 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2230 | return -EBADMSG; | |
2231 | } | |
2232 | } | |
2233 | ||
1c02e7ba | 2234 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2235 | if (r < 0) |
2236 | return r; | |
2237 | if (r == 0) | |
2238 | continue; | |
2239 | ||
2240 | return t->answer_authenticated; | |
2241 | } | |
2242 | ||
2243 | return true; | |
2244 | } | |
2245 | ||
2246 | default: { | |
2247 | DnsTransaction *dt; | |
2248 | Iterator i; | |
2249 | ||
b63fca62 | 2250 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2251 | |
2252 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2253 | ||
2254 | if (dt->key->class != rr->key->class) | |
2255 | continue; | |
2256 | if (dt->key->type != DNS_TYPE_SOA) | |
2257 | continue; | |
2258 | ||
1c02e7ba | 2259 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2260 | if (r < 0) |
2261 | return r; | |
2262 | if (r == 0) | |
2263 | continue; | |
2264 | ||
2265 | /* We found the transaction that was supposed to find | |
2266 | * the SOA RR for us. It was successful, but found no | |
2267 | * RR for us. This means we are not at a zone cut. In | |
2268 | * this case, we require authentication if the SOA | |
2269 | * lookup was authenticated too. */ | |
2270 | return t->answer_authenticated; | |
2271 | } | |
2272 | ||
2273 | return true; | |
2274 | }} | |
56352fe9 LP |
2275 | } |
2276 | ||
d33b6cf3 LP |
2277 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2278 | DnsTransaction *dt; | |
2279 | const char *tld; | |
2280 | Iterator i; | |
2281 | int r; | |
2282 | ||
2283 | /* If DNSSEC downgrade mode is on, checks whether the | |
2284 | * specified RR is one level below a TLD we have proven not to | |
2285 | * exist. In such a case we assume that this is a private | |
2286 | * domain, and permit it. | |
2287 | * | |
2288 | * This detects cases like the Fritz!Box router networks. Each | |
2289 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2290 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2291 | * are served by the router itself, while requests for the | |
2292 | * "box" domain will result in NXDOMAIN. | |
2293 | * | |
2294 | * Note that this logic is unable to detect cases where a | |
2295 | * router serves a private DNS zone directly under | |
2296 | * non-existing TLD. In such a case we cannot detect whether | |
2297 | * the TLD is supposed to exist or not, as all requests we | |
2298 | * make for it will be answered by the router's zone, and not | |
2299 | * by the root zone. */ | |
2300 | ||
2301 | assert(t); | |
2302 | ||
2303 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2304 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2305 | ||
1c02e7ba | 2306 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2307 | r = dns_name_parent(&tld); |
2308 | if (r < 0) | |
2309 | return r; | |
2310 | if (r == 0) | |
2311 | return false; /* Already the root domain */ | |
2312 | ||
2313 | if (!dns_name_is_single_label(tld)) | |
2314 | return false; | |
2315 | ||
2316 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2317 | ||
2318 | if (dt->key->class != key->class) | |
2319 | continue; | |
2320 | ||
1c02e7ba | 2321 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2322 | if (r < 0) |
2323 | return r; | |
2324 | if (r == 0) | |
2325 | continue; | |
2326 | ||
2327 | /* We found an auxiliary lookup we did for the TLD. If | |
2328 | * that returned with NXDOMAIN, we know the TLD didn't | |
2329 | * exist, and hence this might be a private zone. */ | |
2330 | ||
2331 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2332 | } | |
2333 | ||
2334 | return false; | |
2335 | } | |
2336 | ||
105e1512 | 2337 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2338 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2339 | DnsTransaction *dt; |
2340 | const char *name; | |
4bbc06cc | 2341 | uint16_t type = 0; |
105e1512 LP |
2342 | Iterator i; |
2343 | int r; | |
56352fe9 LP |
2344 | |
2345 | assert(t); | |
2346 | ||
105e1512 LP |
2347 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2348 | * this negative reply */ | |
56352fe9 | 2349 | |
b652d4a2 | 2350 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2351 | return false; |
56352fe9 | 2352 | |
105e1512 LP |
2353 | if (dns_type_is_pseudo(t->key->type)) |
2354 | return -EINVAL; | |
2355 | ||
1c02e7ba | 2356 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2357 | if (r < 0) |
2358 | return r; | |
2359 | if (r > 0) | |
2360 | return false; | |
2361 | ||
d33b6cf3 LP |
2362 | r = dns_transaction_in_private_tld(t, t->key); |
2363 | if (r < 0) | |
2364 | return r; | |
2365 | if (r > 0) { | |
2366 | /* The lookup is from a TLD that is proven not to | |
2367 | * exist, and we are in downgrade mode, hence ignore | |
2368 | * that fact that we didn't get any NSEC RRs.*/ | |
2369 | ||
202b76ae ZJS |
2370 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2371 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2372 | return false; |
2373 | } | |
2374 | ||
1c02e7ba | 2375 | name = dns_resource_key_name(t->key); |
105e1512 | 2376 | |
4bbc06cc | 2377 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2378 | |
4bbc06cc LP |
2379 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2380 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2381 | |
2382 | r = dns_name_parent(&name); | |
56352fe9 LP |
2383 | if (r < 0) |
2384 | return r; | |
2385 | if (r == 0) | |
105e1512 | 2386 | return true; |
4bbc06cc LP |
2387 | |
2388 | type = DNS_TYPE_SOA; | |
2389 | ||
2390 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2391 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2392 | type = DNS_TYPE_DS; | |
2393 | else | |
2394 | /* For all other negative replies, check for the SOA lookup */ | |
2395 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2396 | |
2397 | /* For all other RRs we check the SOA on the same level to see | |
2398 | * if it's signed. */ | |
2399 | ||
2400 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2401 | ||
2402 | if (dt->key->class != t->key->class) | |
2403 | continue; | |
4bbc06cc | 2404 | if (dt->key->type != type) |
56352fe9 LP |
2405 | continue; |
2406 | ||
1c02e7ba | 2407 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2408 | if (r < 0) |
2409 | return r; | |
105e1512 LP |
2410 | if (r == 0) |
2411 | continue; | |
2412 | ||
2413 | return dt->answer_authenticated; | |
56352fe9 LP |
2414 | } |
2415 | ||
105e1512 LP |
2416 | /* If in doubt, require NSEC/NSEC3 */ |
2417 | return true; | |
56352fe9 LP |
2418 | } |
2419 | ||
94aa7071 LP |
2420 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2421 | DnsResourceRecord *rrsig; | |
2422 | bool found = false; | |
2423 | int r; | |
2424 | ||
2425 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2426 | * the specified RRset is authenticated (i.e. has a matching | |
2427 | * DS RR). */ | |
2428 | ||
1c02e7ba | 2429 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2430 | if (r < 0) |
2431 | return r; | |
2432 | if (r > 0) | |
2433 | return false; | |
2434 | ||
94aa7071 LP |
2435 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2436 | DnsTransaction *dt; | |
2437 | Iterator i; | |
2438 | ||
2439 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2440 | if (r < 0) | |
2441 | return r; | |
2442 | if (r == 0) | |
2443 | continue; | |
2444 | ||
2445 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2446 | ||
2447 | if (dt->key->class != rr->key->class) | |
2448 | continue; | |
2449 | ||
2450 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2451 | ||
1c02e7ba | 2452 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2453 | if (r < 0) |
2454 | return r; | |
2455 | if (r == 0) | |
2456 | continue; | |
2457 | ||
2458 | /* OK, we found an auxiliary DNSKEY | |
2459 | * lookup. If that lookup is | |
2460 | * authenticated, report this. */ | |
2461 | ||
2462 | if (dt->answer_authenticated) | |
2463 | return true; | |
2464 | ||
2465 | found = true; | |
2466 | ||
2467 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2468 | ||
1c02e7ba | 2469 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2470 | if (r < 0) |
2471 | return r; | |
2472 | if (r == 0) | |
2473 | continue; | |
2474 | ||
2475 | /* OK, we found an auxiliary DS | |
2476 | * lookup. If that lookup is | |
2477 | * authenticated and non-zero, we | |
2478 | * won! */ | |
2479 | ||
2480 | if (!dt->answer_authenticated) | |
2481 | return false; | |
2482 | ||
2483 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2484 | } | |
2485 | } | |
2486 | } | |
2487 | ||
2488 | return found ? false : -ENXIO; | |
2489 | } | |
2490 | ||
b652d4a2 LP |
2491 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2492 | assert(t); | |
2493 | assert(rr); | |
2494 | ||
2495 | /* We know that the root domain is signed, hence if it appears | |
2496 | * not to be signed, there's a problem with the DNS server */ | |
2497 | ||
2498 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2499 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2500 | } |
2501 | ||
0f87f3e8 LP |
2502 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2503 | DnsResourceRecord *rr; | |
2504 | int r; | |
2505 | ||
2506 | assert(t); | |
2507 | ||
2508 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2509 | * for a key from our trust anchor. Note that we don't care | |
2510 | * whether the DNSKEY can be authenticated or not. It's | |
2511 | * sufficient if it is self-signed. */ | |
2512 | ||
2513 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2514 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2515 | if (r < 0) |
2516 | return r; | |
2517 | } | |
2518 | ||
2519 | return 0; | |
2520 | } | |
2521 | ||
c9c72065 LP |
2522 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2523 | bool changed; | |
2524 | int r; | |
2525 | ||
2526 | assert(t); | |
2527 | ||
2528 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2529 | * our trust anchors database considers revoked. */ | |
2530 | ||
2531 | do { | |
2532 | DnsResourceRecord *rr; | |
2533 | ||
2534 | changed = false; | |
2535 | ||
2536 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2537 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2538 | if (r < 0) | |
2539 | return r; | |
2540 | if (r > 0) { | |
2541 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2542 | if (r < 0) | |
2543 | return r; | |
2544 | ||
2545 | assert(r > 0); | |
2546 | changed = true; | |
2547 | break; | |
2548 | } | |
2549 | } | |
2550 | } while (changed); | |
2551 | ||
2552 | return 0; | |
2553 | } | |
2554 | ||
942eb2e7 LP |
2555 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2556 | DnsTransaction *dt; | |
2557 | Iterator i; | |
2558 | int r; | |
2559 | ||
2560 | assert(t); | |
2561 | ||
2562 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2563 | ||
2564 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2565 | ||
2566 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2567 | continue; | |
2568 | ||
2569 | if (!dt->answer_authenticated) | |
2570 | continue; | |
2571 | ||
2572 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2573 | if (r < 0) | |
2574 | return r; | |
2575 | } | |
2576 | ||
2577 | return 0; | |
2578 | } | |
2579 | ||
c690b20a ZJS |
2580 | typedef enum { |
2581 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2582 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2583 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2584 | } Phase; | |
2585 | ||
2586 | static int dnssec_validate_records( | |
2587 | DnsTransaction *t, | |
2588 | Phase phase, | |
2589 | bool *have_nsec, | |
2590 | DnsAnswer **validated) { | |
2591 | ||
547973de | 2592 | DnsResourceRecord *rr; |
56352fe9 | 2593 | int r; |
547973de | 2594 | |
c690b20a | 2595 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2596 | |
c690b20a ZJS |
2597 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2598 | DnsResourceRecord *rrsig = NULL; | |
2599 | DnssecResult result; | |
547973de | 2600 | |
c690b20a ZJS |
2601 | switch (rr->key->type) { |
2602 | case DNS_TYPE_RRSIG: | |
2603 | continue; | |
547973de | 2604 | |
c690b20a ZJS |
2605 | case DNS_TYPE_DNSKEY: |
2606 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2607 | if (phase == DNSSEC_PHASE_NSEC) | |
2608 | continue; | |
2609 | break; | |
547973de | 2610 | |
c690b20a ZJS |
2611 | case DNS_TYPE_NSEC: |
2612 | case DNS_TYPE_NSEC3: | |
2613 | *have_nsec = true; | |
547973de | 2614 | |
c690b20a ZJS |
2615 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2616 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2617 | continue; | |
2618 | break; | |
105e1512 | 2619 | |
c690b20a ZJS |
2620 | default: |
2621 | /* We validate all other RRs only in the ALL phases */ | |
2622 | if (phase != DNSSEC_PHASE_ALL) | |
2623 | continue; | |
2624 | } | |
b652d4a2 | 2625 | |
c690b20a ZJS |
2626 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2627 | if (r < 0) | |
2628 | return r; | |
547973de | 2629 | |
c690b20a | 2630 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2631 | |
c690b20a | 2632 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2633 | |
c690b20a ZJS |
2634 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2635 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2636 | * the set of validated keys for this transaction. */ | |
547973de | 2637 | |
c690b20a ZJS |
2638 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2639 | if (r < 0) | |
2640 | return r; | |
c9c72065 | 2641 | |
c690b20a ZJS |
2642 | /* Some of the DNSKEYs we just added might already have been revoked, |
2643 | * remove them again in that case. */ | |
2644 | r = dns_transaction_invalidate_revoked_keys(t); | |
2645 | if (r < 0) | |
2646 | return r; | |
2647 | } | |
547973de | 2648 | |
c690b20a ZJS |
2649 | /* Add the validated RRset to the new list of validated |
2650 | * RRsets, and remove it from the unvalidated RRsets. | |
2651 | * We mark the RRset as authenticated and cacheable. */ | |
2652 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2653 | if (r < 0) | |
2654 | return r; | |
547973de | 2655 | |
c690b20a | 2656 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2657 | |
c690b20a ZJS |
2658 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2659 | return 1; | |
2660 | } | |
547973de | 2661 | |
c690b20a ZJS |
2662 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2663 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2664 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2665 | if (phase != DNSSEC_PHASE_ALL) | |
2666 | continue; | |
0c7bff0a | 2667 | |
c690b20a ZJS |
2668 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2669 | bool authenticated = false; | |
2670 | const char *source; | |
0c7bff0a | 2671 | |
c690b20a ZJS |
2672 | /* This RRset validated, but as a wildcard. This means we need |
2673 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists.*/ | |
0c7bff0a | 2674 | |
c690b20a ZJS |
2675 | /* First step, determine the source of synthesis */ |
2676 | r = dns_resource_record_source(rrsig, &source); | |
2677 | if (r < 0) | |
2678 | return r; | |
0c7bff0a | 2679 | |
c690b20a | 2680 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2681 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2682 | source, |
2683 | rrsig->rrsig.signer, | |
2684 | &authenticated); | |
0c7bff0a | 2685 | |
c690b20a ZJS |
2686 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2687 | if (r == 0) | |
2688 | result = DNSSEC_INVALID; | |
2689 | else { | |
2690 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2691 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2692 | if (r < 0) | |
2693 | return r; | |
2694 | ||
2695 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2696 | ||
2697 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2698 | return 1; | |
0c7bff0a | 2699 | } |
c690b20a | 2700 | } |
0c7bff0a | 2701 | |
c690b20a ZJS |
2702 | if (result == DNSSEC_NO_SIGNATURE) { |
2703 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2704 | if (r < 0) |
2705 | return r; | |
c690b20a ZJS |
2706 | if (r == 0) { |
2707 | /* Data does not require signing. In that case, just copy it over, | |
2708 | * but remember that this is by no means authenticated.*/ | |
2709 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); | |
2710 | if (r < 0) | |
2711 | return r; | |
2712 | ||
2713 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2714 | return 1; | |
2715 | } | |
547973de | 2716 | |
c690b20a ZJS |
2717 | r = dns_transaction_known_signed(t, rr); |
2718 | if (r < 0) | |
2719 | return r; | |
2720 | if (r > 0) { | |
2721 | /* This is an RR we know has to be signed. If it isn't this means | |
2722 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2723 | |
c690b20a | 2724 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2725 | |
c690b20a | 2726 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2727 | |
c690b20a | 2728 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2729 | |
c690b20a | 2730 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2731 | if (r < 0) |
2732 | return r; | |
547973de | 2733 | |
c690b20a ZJS |
2734 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2735 | return 1; | |
2736 | } | |
a150ff5e | 2737 | |
c690b20a ZJS |
2738 | /* Otherwise, fail */ |
2739 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2740 | return 0; | |
f3cf586d | 2741 | } |
547973de | 2742 | |
c690b20a ZJS |
2743 | r = dns_transaction_in_private_tld(t, rr->key); |
2744 | if (r < 0) | |
2745 | return r; | |
2746 | if (r > 0) { | |
202b76ae | 2747 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2748 | |
c690b20a ZJS |
2749 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2750 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2751 | |
202b76ae ZJS |
2752 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2753 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2754 | |
c690b20a | 2755 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2756 | if (r < 0) |
2757 | return r; | |
0c7bff0a | 2758 | |
c690b20a ZJS |
2759 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2760 | return 1; | |
2761 | } | |
2762 | } | |
0c7bff0a | 2763 | |
c690b20a ZJS |
2764 | if (IN_SET(result, |
2765 | DNSSEC_MISSING_KEY, | |
2766 | DNSSEC_SIGNATURE_EXPIRED, | |
2767 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2768 | |
c690b20a ZJS |
2769 | r = dns_transaction_dnskey_authenticated(t, rr); |
2770 | if (r < 0 && r != -ENXIO) | |
2771 | return r; | |
2772 | if (r == 0) { | |
2773 | /* The DNSKEY transaction was not authenticated, this means there's | |
2774 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2775 | |
c690b20a | 2776 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2777 | if (r < 0) |
2778 | return r; | |
b652d4a2 | 2779 | |
c690b20a ZJS |
2780 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2781 | return 1; | |
2782 | } | |
2783 | } | |
b652d4a2 | 2784 | |
c690b20a ZJS |
2785 | r = dns_transaction_is_primary_response(t, rr); |
2786 | if (r < 0) | |
2787 | return r; | |
2788 | if (r > 0) { | |
2789 | /* Look for a matching DNAME for this CNAME */ | |
2790 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2791 | if (r < 0) | |
2792 | return r; | |
2793 | if (r == 0) { | |
2794 | /* Also look among the stuff we already validated */ | |
2795 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2796 | if (r < 0) |
2797 | return r; | |
c690b20a | 2798 | } |
d33b6cf3 | 2799 | |
c690b20a ZJS |
2800 | if (r == 0) { |
2801 | if (IN_SET(result, | |
2802 | DNSSEC_INVALID, | |
2803 | DNSSEC_SIGNATURE_EXPIRED, | |
2804 | DNSSEC_NO_SIGNATURE)) | |
2805 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
2806 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2807 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
2808 | ||
2809 | /* This is a primary response to our question, and it failed validation. | |
2810 | * That's fatal. */ | |
2811 | t->answer_dnssec_result = result; | |
2812 | return 0; | |
2813 | } | |
d33b6cf3 | 2814 | |
c690b20a ZJS |
2815 | /* This is a primary response, but we do have a DNAME RR |
2816 | * in the RR that can replay this CNAME, hence rely on | |
2817 | * that, and we can remove the CNAME in favour of it. */ | |
2818 | } | |
d33b6cf3 | 2819 | |
c690b20a ZJS |
2820 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
2821 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2822 | if (r < 0) | |
2823 | return r; | |
d33b6cf3 | 2824 | |
c690b20a ZJS |
2825 | /* We dropped something from the answer, start from the beginning. */ |
2826 | return 1; | |
2827 | } | |
f3cf586d | 2828 | |
c690b20a ZJS |
2829 | return 2; /* Finito. */ |
2830 | } | |
94aa7071 | 2831 | |
c690b20a ZJS |
2832 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2833 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
2834 | Phase phase; | |
2835 | DnsAnswerFlags flags; | |
2836 | int r; | |
202b76ae | 2837 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 2838 | |
c690b20a | 2839 | assert(t); |
94aa7071 | 2840 | |
c690b20a ZJS |
2841 | /* We have now collected all DS and DNSKEY RRs in |
2842 | * t->validated_keys, let's see which RRs we can now | |
2843 | * authenticate with that. */ | |
94aa7071 | 2844 | |
c690b20a ZJS |
2845 | if (t->scope->dnssec_mode == DNSSEC_NO) |
2846 | return 0; | |
a150ff5e | 2847 | |
c690b20a ZJS |
2848 | /* Already validated */ |
2849 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
2850 | return 0; | |
105e1512 | 2851 | |
c690b20a ZJS |
2852 | /* Our own stuff needs no validation */ |
2853 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
2854 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
2855 | t->answer_authenticated = true; | |
2856 | return 0; | |
2857 | } | |
a150ff5e | 2858 | |
c690b20a ZJS |
2859 | /* Cached stuff is not affected by validation. */ |
2860 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2861 | return 0; | |
f3cf586d | 2862 | |
c690b20a ZJS |
2863 | if (!dns_transaction_dnssec_supported_full(t)) { |
2864 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2865 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2866 | log_debug("Not validating response for %" PRIu16 ", server lacks DNSSEC support.", t->id); | |
2867 | return 0; | |
2868 | } | |
f3cf586d | 2869 | |
202b76ae ZJS |
2870 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
2871 | t->id, | |
2872 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 2873 | |
c690b20a ZJS |
2874 | /* First, see if this response contains any revoked trust |
2875 | * anchors we care about */ | |
2876 | r = dns_transaction_check_revoked_trust_anchors(t); | |
2877 | if (r < 0) | |
2878 | return r; | |
43e6779a | 2879 | |
c690b20a ZJS |
2880 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
2881 | r = dns_transaction_copy_validated(t); | |
2882 | if (r < 0) | |
2883 | return r; | |
43e6779a | 2884 | |
c690b20a ZJS |
2885 | /* Second, see if there are DNSKEYs we already know a |
2886 | * validated DS for. */ | |
2887 | r = dns_transaction_validate_dnskey_by_ds(t); | |
2888 | if (r < 0) | |
2889 | return r; | |
43e6779a | 2890 | |
c690b20a ZJS |
2891 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
2892 | * anchor says are revoked. After all we might have marked | |
2893 | * some keys revoked above, but they might still be lingering | |
2894 | * in our validated_keys list. */ | |
2895 | r = dns_transaction_invalidate_revoked_keys(t); | |
2896 | if (r < 0) | |
2897 | return r; | |
f3cf586d | 2898 | |
c690b20a ZJS |
2899 | phase = DNSSEC_PHASE_DNSKEY; |
2900 | for (;;) { | |
2901 | bool have_nsec = false; | |
f3cf586d | 2902 | |
c690b20a ZJS |
2903 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
2904 | if (r <= 0) | |
2905 | return r; | |
547973de | 2906 | |
c690b20a ZJS |
2907 | /* Try again as long as we managed to achieve something */ |
2908 | if (r == 1) | |
547973de LP |
2909 | continue; |
2910 | ||
c690b20a | 2911 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 2912 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 2913 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
2914 | continue; |
2915 | } | |
2916 | ||
c690b20a ZJS |
2917 | if (phase != DNSSEC_PHASE_ALL) { |
2918 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
2919 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
2920 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 2921 | continue; |
547973de LP |
2922 | } |
2923 | ||
56352fe9 | 2924 | /* We're done */ |
547973de LP |
2925 | break; |
2926 | } | |
2927 | ||
2928 | dns_answer_unref(t->answer); | |
2929 | t->answer = validated; | |
2930 | validated = NULL; | |
2931 | ||
72667f08 LP |
2932 | /* At this point the answer only contains validated |
2933 | * RRsets. Now, let's see if it actually answers the question | |
2934 | * we asked. If so, great! If it doesn't, then see if | |
2935 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2936 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2937 | if (r > 0) { |
105e1512 LP |
2938 | /* Yes, it answers the question! */ |
2939 | ||
2940 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2941 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2942 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2943 | t->answer_rcode = DNS_RCODE_SUCCESS; |
2944 | t->answer_authenticated = true; | |
2945 | } else { | |
2946 | /* The answer is not fully authenticated. */ | |
019036a4 | 2947 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2948 | t->answer_authenticated = false; |
2949 | } | |
2950 | ||
72667f08 LP |
2951 | } else if (r == 0) { |
2952 | DnssecNsecResult nr; | |
ed29bfdc | 2953 | bool authenticated = false; |
72667f08 LP |
2954 | |
2955 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 2956 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
2957 | if (r < 0) |
2958 | return r; | |
2959 | ||
2960 | switch (nr) { | |
2961 | ||
2962 | case DNSSEC_NSEC_NXDOMAIN: | |
2963 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 2964 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 2965 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2966 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 2967 | t->answer_authenticated = authenticated; |
7aa8ce98 | 2968 | |
59c5b597 | 2969 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
2970 | break; |
2971 | ||
2972 | case DNSSEC_NSEC_NODATA: | |
2973 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 2974 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 2975 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2976 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 2977 | t->answer_authenticated = authenticated; |
7aa8ce98 | 2978 | |
59c5b597 | 2979 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
2980 | break; |
2981 | ||
105e1512 LP |
2982 | case DNSSEC_NSEC_OPTOUT: |
2983 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 2984 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 2985 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 2986 | t->answer_authenticated = false; |
7aa8ce98 | 2987 | |
59c5b597 | 2988 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
2989 | break; |
2990 | ||
72667f08 LP |
2991 | case DNSSEC_NSEC_NO_RR: |
2992 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
2993 | |
2994 | r = dns_transaction_requires_nsec(t); | |
2995 | if (r < 0) | |
2996 | return r; | |
7aa8ce98 | 2997 | if (r > 0) { |
019036a4 | 2998 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 2999 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3000 | } else { |
019036a4 | 3001 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3002 | t->answer_authenticated = false; |
59c5b597 | 3003 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3004 | } |
3005 | ||
3006 | break; | |
3007 | ||
3008 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3009 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3010 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3011 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3012 | break; |
3013 | ||
3014 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3015 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3016 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3017 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3018 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3019 | break; |
3020 | ||
3021 | default: | |
3022 | assert_not_reached("Unexpected NSEC result."); | |
3023 | } | |
3024 | } | |
3025 | ||
547973de LP |
3026 | return 1; |
3027 | } | |
3028 | ||
ec2c5e43 LP |
3029 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3030 | [DNS_TRANSACTION_NULL] = "null", | |
3031 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3032 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3033 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3034 | [DNS_TRANSACTION_SUCCESS] = "success", |
3035 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3036 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3037 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3038 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3039 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3040 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3041 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3042 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3043 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3044 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3045 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3046 | }; |
3047 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3048 | |
3049 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3050 | [DNS_TRANSACTION_NETWORK] = "network", | |
3051 | [DNS_TRANSACTION_CACHE] = "cache", | |
3052 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3053 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3054 | }; |
3055 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |