]>
Commit | Line | Data |
---|---|---|
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 | ||
62cc1c55 | 20 | #include "sd-messages.h" |
beef6a5f | 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 | 33 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 34 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 35 | |
c61d2b44 LP |
36 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
37 | assert(t); | |
38 | ||
39 | t->received = dns_packet_unref(t->received); | |
40 | t->answer = dns_answer_unref(t->answer); | |
41 | t->answer_rcode = 0; | |
42 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
43 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
44 | t->answer_authenticated = false; | |
d3760be0 | 45 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 46 | t->answer_errno = 0; |
c61d2b44 LP |
47 | } |
48 | ||
c5b4f861 LP |
49 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
50 | DnsTransaction *z; | |
51 | ||
52 | assert(t); | |
53 | ||
54 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
55 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 56 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
57 | dns_transaction_gc(z); |
58 | } | |
59 | } | |
60 | ||
f32f0e57 LP |
61 | static void dns_transaction_close_connection(DnsTransaction *t) { |
62 | assert(t); | |
63 | ||
b30bf55d LP |
64 | if (t->stream) { |
65 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
66 | t->stream->complete = NULL; | |
67 | t->stream->on_packet = NULL; | |
68 | t->stream->transaction = NULL; | |
69 | t->stream = dns_stream_unref(t->stream); | |
70 | } | |
71 | ||
f32f0e57 LP |
72 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
73 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
74 | } | |
75 | ||
f535705a | 76 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
77 | assert(t); |
78 | ||
79 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
80 | } |
81 | ||
ec2c5e43 | 82 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 83 | DnsQueryCandidate *c; |
ec2c5e43 | 84 | DnsZoneItem *i; |
547973de | 85 | DnsTransaction *z; |
ec2c5e43 LP |
86 | |
87 | if (!t) | |
88 | return NULL; | |
89 | ||
51e399bc LP |
90 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
91 | ||
f32f0e57 | 92 | dns_transaction_close_connection(t); |
f535705a | 93 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 94 | |
ec2c5e43 | 95 | dns_packet_unref(t->sent); |
c61d2b44 | 96 | dns_transaction_reset_answer(t); |
ec2c5e43 | 97 | |
8300ba21 | 98 | dns_server_unref(t->server); |
ec2c5e43 LP |
99 | |
100 | if (t->scope) { | |
f9ebb22a LP |
101 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
102 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
103 | |
104 | if (t->id != 0) | |
105 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
106 | } | |
107 | ||
547973de | 108 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 109 | set_remove(c->transactions, t); |
547973de | 110 | set_free(t->notify_query_candidates); |
801ad6a6 | 111 | |
35aa04e9 LP |
112 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
113 | set_remove(c->transactions, t); | |
114 | set_free(t->notify_query_candidates_done); | |
115 | ||
547973de | 116 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 117 | i->probe_transaction = NULL; |
547973de LP |
118 | set_free(t->notify_zone_items); |
119 | ||
35aa04e9 LP |
120 | while ((i = set_steal_first(t->notify_zone_items_done))) |
121 | i->probe_transaction = NULL; | |
122 | set_free(t->notify_zone_items_done); | |
123 | ||
547973de LP |
124 | while ((z = set_steal_first(t->notify_transactions))) |
125 | set_remove(z->dnssec_transactions, t); | |
126 | set_free(t->notify_transactions); | |
127 | ||
35aa04e9 LP |
128 | while ((z = set_steal_first(t->notify_transactions_done))) |
129 | set_remove(z->dnssec_transactions, t); | |
130 | set_free(t->notify_transactions_done); | |
131 | ||
c5b4f861 | 132 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
133 | set_free(t->dnssec_transactions); |
134 | ||
135 | dns_answer_unref(t->validated_keys); | |
97cc656c | 136 | dns_resource_key_unref(t->key); |
97cc656c | 137 | |
6b430fdb | 138 | return mfree(t); |
ec2c5e43 LP |
139 | } |
140 | ||
141 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
142 | ||
51e399bc | 143 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
144 | assert(t); |
145 | ||
146 | if (t->block_gc > 0) | |
51e399bc | 147 | return true; |
ec2c5e43 | 148 | |
547973de | 149 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 150 | set_isempty(t->notify_query_candidates_done) && |
547973de | 151 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
152 | set_isempty(t->notify_zone_items_done) && |
153 | set_isempty(t->notify_transactions) && | |
154 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 155 | dns_transaction_free(t); |
51e399bc LP |
156 | return false; |
157 | } | |
158 | ||
159 | return true; | |
ec2c5e43 LP |
160 | } |
161 | ||
4dd15077 LP |
162 | static uint16_t pick_new_id(Manager *m) { |
163 | uint16_t new_id; | |
164 | ||
165 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
166 | * transactions, and it's much lower than the space of IDs. */ | |
167 | ||
168 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
169 | ||
170 | do | |
171 | random_bytes(&new_id, sizeof(new_id)); | |
172 | while (new_id == 0 || | |
173 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
174 | ||
175 | return new_id; | |
176 | } | |
177 | ||
f52e61da | 178 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
179 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
180 | int r; | |
181 | ||
182 | assert(ret); | |
183 | assert(s); | |
f52e61da | 184 | assert(key); |
ec2c5e43 | 185 | |
9eae2bf3 | 186 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 187 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 188 | return -EINVAL; |
d0129ddb LP |
189 | if (dns_type_is_obsolete(key->type)) |
190 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
191 | |
192 | /* We only support the IN class */ | |
4c701096 | 193 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
194 | return -EOPNOTSUPP; |
195 | ||
b214dc0f LP |
196 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
197 | return -EBUSY; | |
198 | ||
d5099efc | 199 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
200 | if (r < 0) |
201 | return r; | |
202 | ||
f9ebb22a | 203 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
204 | if (r < 0) |
205 | return r; | |
206 | ||
ec2c5e43 LP |
207 | t = new0(DnsTransaction, 1); |
208 | if (!t) | |
209 | return -ENOMEM; | |
210 | ||
4667e00a | 211 | t->dns_udp_fd = -1; |
c3bc53e6 | 212 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 213 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 214 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 215 | t->key = dns_resource_key_ref(key); |
274b8748 | 216 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
d001e0a3 | 217 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 218 | |
4dd15077 | 219 | t->id = pick_new_id(s->manager); |
ec2c5e43 LP |
220 | |
221 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
222 | if (r < 0) { | |
223 | t->id = 0; | |
224 | return r; | |
225 | } | |
226 | ||
f9ebb22a | 227 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
228 | if (r < 0) { |
229 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
230 | return r; | |
231 | } | |
232 | ||
f9ebb22a | 233 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
234 | t->scope = s; |
235 | ||
313cefa1 | 236 | s->manager->n_transactions_total++; |
a150ff5e | 237 | |
ec2c5e43 LP |
238 | if (ret) |
239 | *ret = t; | |
240 | ||
241 | t = NULL; | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
4dd15077 LP |
246 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
247 | uint16_t new_id; | |
248 | assert(t); | |
249 | ||
250 | /* Pick a new ID for this transaction. */ | |
251 | ||
252 | new_id = pick_new_id(t->scope->manager); | |
253 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
254 | ||
255 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
256 | t->id = new_id; | |
257 | ||
258 | /* Make sure we generate a new packet with the new ID */ | |
259 | t->sent = dns_packet_unref(t->sent); | |
260 | } | |
261 | ||
ec2c5e43 | 262 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 263 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 264 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 265 | DnsZoneItem *z; |
ec2c5e43 LP |
266 | |
267 | assert(t); | |
268 | assert(p); | |
269 | ||
270 | if (manager_our_packet(t->scope->manager, p) != 0) | |
271 | return; | |
272 | ||
164d025d | 273 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 274 | |
a5784c49 LP |
275 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
276 | t->id, | |
202b76ae | 277 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
278 | dns_protocol_to_string(t->scope->protocol), |
279 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 280 | af_to_name_short(t->scope->family), |
164d025d | 281 | strnull(pretty)); |
ec2c5e43 | 282 | |
a4076574 LP |
283 | /* RFC 4795, Section 4.1 says that the peer with the |
284 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
285 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
286 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
287 | return; |
288 | } | |
289 | ||
4d91eec4 | 290 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 291 | |
ec2c5e43 | 292 | t->block_gc++; |
35aa04e9 | 293 | |
547973de | 294 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
295 | /* First, make sure the zone item drops the reference |
296 | * to us */ | |
297 | dns_zone_item_probe_stop(z); | |
298 | ||
299 | /* Secondly, report this as conflict, so that we might | |
300 | * look for a different hostname */ | |
ec2c5e43 | 301 | dns_zone_item_conflict(z); |
3ef64445 | 302 | } |
ec2c5e43 LP |
303 | t->block_gc--; |
304 | ||
305 | dns_transaction_gc(t); | |
306 | } | |
307 | ||
308 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 309 | DnsQueryCandidate *c; |
ec2c5e43 | 310 | DnsZoneItem *z; |
547973de | 311 | DnsTransaction *d; |
7cc6ed7b | 312 | const char *st; |
202b76ae | 313 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
314 | |
315 | assert(t); | |
547973de | 316 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 317 | |
202b76ae ZJS |
318 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
319 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
320 | ||
f61dfddb | 321 | log_struct(LOG_NOTICE, |
2b044526 | 322 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
202b76ae | 323 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 324 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 325 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 326 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
1e02e182 LP |
327 | "DNS_SERVER=%s", dns_server_string(t->server), |
328 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level), | |
f61dfddb | 329 | NULL); |
202b76ae | 330 | } |
f61dfddb | 331 | |
ec2c5e43 LP |
332 | /* Note that this call might invalidate the query. Callers |
333 | * should hence not attempt to access the query or transaction | |
334 | * after calling this function. */ | |
335 | ||
7cc6ed7b LP |
336 | if (state == DNS_TRANSACTION_ERRNO) |
337 | st = errno_to_name(t->answer_errno); | |
338 | else | |
339 | st = dns_transaction_state_to_string(state); | |
340 | ||
a5784c49 LP |
341 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
342 | t->id, | |
202b76ae | 343 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
344 | dns_protocol_to_string(t->scope->protocol), |
345 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 346 | af_to_name_short(t->scope->family), |
7cc6ed7b | 347 | st, |
a5784c49 LP |
348 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
349 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
350 | |
351 | t->state = state; | |
352 | ||
f32f0e57 | 353 | dns_transaction_close_connection(t); |
f535705a | 354 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
355 | |
356 | /* Notify all queries that are interested, but make sure the | |
357 | * transaction isn't freed while we are still looking at it */ | |
358 | t->block_gc++; | |
f7014757 | 359 | |
35aa04e9 | 360 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 361 | dns_query_candidate_notify(c); |
35aa04e9 | 362 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 363 | |
35aa04e9 LP |
364 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
365 | dns_zone_item_notify(z); | |
366 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
c3ae4188 | 367 | if (t->probing) |
1a63fc54 | 368 | (void) dns_scope_announce(t->scope, false); |
f7014757 | 369 | |
35aa04e9 LP |
370 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
371 | dns_transaction_notify(d, t); | |
372 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
373 | |
374 | t->block_gc--; | |
ec2c5e43 LP |
375 | dns_transaction_gc(t); |
376 | } | |
377 | ||
519ef046 LP |
378 | static int dns_transaction_pick_server(DnsTransaction *t) { |
379 | DnsServer *server; | |
380 | ||
381 | assert(t); | |
382 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
383 | ||
d001e0a3 LP |
384 | /* Pick a DNS server and a feature level for it. */ |
385 | ||
519ef046 LP |
386 | server = dns_scope_get_dns_server(t->scope); |
387 | if (!server) | |
388 | return -ESRCH; | |
389 | ||
d001e0a3 LP |
390 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
391 | * different properties. */ | |
392 | if (server != t->server) | |
393 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
394 | ||
274b8748 | 395 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 396 | |
d001e0a3 LP |
397 | /* Clamp the feature level if that is requested. */ |
398 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
399 | t->current_feature_level > t->clamp_feature_level) | |
400 | t->current_feature_level = t->clamp_feature_level; | |
401 | ||
402 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
403 | ||
519ef046 LP |
404 | if (server == t->server) |
405 | return 0; | |
406 | ||
407 | dns_server_unref(t->server); | |
408 | t->server = dns_server_ref(server); | |
409 | ||
d001e0a3 LP |
410 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
411 | ||
519ef046 LP |
412 | return 1; |
413 | } | |
414 | ||
d001e0a3 | 415 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
416 | int r; |
417 | ||
418 | assert(t); | |
419 | ||
420 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
421 | ||
422 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
423 | if (next_server) |
424 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
425 | |
426 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
427 | if (r < 0) { |
428 | t->answer_errno = -r; | |
429 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
430 | } | |
8d10d620 LP |
431 | } |
432 | ||
c02cf2f4 | 433 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
434 | int r; |
435 | ||
c02cf2f4 LP |
436 | assert(t); |
437 | ||
5278bbfe LP |
438 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
439 | ||
c02cf2f4 LP |
440 | if (!t->server) |
441 | return 0; | |
442 | ||
443 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
444 | return 0; | |
445 | ||
446 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
447 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
448 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
449 | OPT RR or DO bit. One of these cases is documented here, for example: | |
450 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
451 | ||
4dd15077 LP |
452 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
453 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
454 | |
455 | r = dns_transaction_go(t); | |
456 | if (r < 0) | |
457 | return r; | |
458 | ||
459 | return 1; | |
c02cf2f4 LP |
460 | } |
461 | ||
ec2c5e43 LP |
462 | static int on_stream_complete(DnsStream *s, int error) { |
463 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
464 | DnsTransaction *t; | |
465 | ||
466 | assert(s); | |
467 | assert(s->transaction); | |
468 | ||
469 | /* Copy the data we care about out of the stream before we | |
470 | * destroy it. */ | |
471 | t = s->transaction; | |
472 | p = dns_packet_ref(s->read_packet); | |
473 | ||
b30bf55d | 474 | dns_transaction_close_connection(t); |
ec2c5e43 | 475 | |
a1a3f73a LP |
476 | if (ERRNO_IS_DISCONNECT(error)) { |
477 | usec_t usec; | |
478 | ||
0791110f LP |
479 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
480 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
481 | * question on this scope. */ | |
482 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
483 | return 0; | |
484 | } | |
485 | ||
92ec902a | 486 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 487 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 488 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a | 489 | |
d001e0a3 | 490 | dns_transaction_retry(t, true); |
ac720200 LP |
491 | return 0; |
492 | } | |
ec2c5e43 | 493 | if (error != 0) { |
7cc6ed7b LP |
494 | t->answer_errno = error; |
495 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
496 | return 0; |
497 | } | |
498 | ||
a4076574 | 499 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 500 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
501 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
502 | return 0; | |
503 | } | |
504 | ||
505 | dns_scope_check_conflicts(t->scope, p); | |
506 | ||
ec2c5e43 LP |
507 | t->block_gc++; |
508 | dns_transaction_process_reply(t, p); | |
509 | t->block_gc--; | |
510 | ||
519ef046 LP |
511 | /* If the response wasn't useful, then complete the transition |
512 | * now. After all, we are the worst feature set now with TCP | |
513 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
514 | if (t->state == DNS_TRANSACTION_PENDING) |
515 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
516 | else |
517 | dns_transaction_gc(t); | |
ec2c5e43 LP |
518 | |
519 | return 0; | |
520 | } | |
521 | ||
522 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
523 | _cleanup_close_ int fd = -1; | |
524 | int r; | |
525 | ||
526 | assert(t); | |
527 | ||
519ef046 | 528 | dns_transaction_close_connection(t); |
ec2c5e43 | 529 | |
106784eb | 530 | switch (t->scope->protocol) { |
519ef046 | 531 | |
106784eb | 532 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
533 | r = dns_transaction_pick_server(t); |
534 | if (r < 0) | |
535 | return r; | |
536 | ||
92ec902a | 537 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
538 | return -EOPNOTSUPP; |
539 | ||
274b8748 | 540 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
541 | if (r < 0) |
542 | return r; | |
543 | ||
544 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 545 | break; |
ec2c5e43 | 546 | |
106784eb | 547 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 548 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 549 | if (t->received) |
519ef046 | 550 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
551 | else { |
552 | union in_addr_union address; | |
a7f7d1bd | 553 | int family = AF_UNSPEC; |
ec2c5e43 LP |
554 | |
555 | /* Otherwise, try to talk to the owner of a | |
556 | * the IP address, in case this is a reverse | |
557 | * PTR lookup */ | |
f52e61da | 558 | |
1c02e7ba | 559 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
560 | if (r < 0) |
561 | return r; | |
562 | if (r == 0) | |
563 | return -EINVAL; | |
9e08a6e0 | 564 | if (family != t->scope->family) |
9318cdd3 | 565 | return -ESRCH; |
ec2c5e43 | 566 | |
519ef046 | 567 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 568 | } |
106784eb DM |
569 | |
570 | break; | |
571 | ||
572 | default: | |
ec2c5e43 | 573 | return -EAFNOSUPPORT; |
106784eb | 574 | } |
ec2c5e43 LP |
575 | |
576 | if (fd < 0) | |
577 | return fd; | |
578 | ||
579 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
580 | if (r < 0) | |
581 | return r; | |
ec2c5e43 LP |
582 | fd = -1; |
583 | ||
584 | r = dns_stream_write_packet(t->stream, t->sent); | |
585 | if (r < 0) { | |
b30bf55d | 586 | t->stream = dns_stream_unref(t->stream); |
ec2c5e43 LP |
587 | return r; |
588 | } | |
589 | ||
ec2c5e43 LP |
590 | t->stream->complete = on_stream_complete; |
591 | t->stream->transaction = t; | |
592 | ||
593 | /* The interface index is difficult to determine if we are | |
594 | * connecting to the local host, hence fill this in right away | |
595 | * instead of determining it from the socket */ | |
97ebebbc | 596 | t->stream->ifindex = dns_scope_ifindex(t->scope); |
ec2c5e43 | 597 | |
519ef046 LP |
598 | dns_transaction_reset_answer(t); |
599 | ||
cbe4216d LP |
600 | t->tried_stream = true; |
601 | ||
ec2c5e43 LP |
602 | return 0; |
603 | } | |
604 | ||
547973de | 605 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
606 | assert(t); |
607 | ||
608 | /* For mDNS we cache whenever we get the packet, rather than | |
609 | * in each transaction. */ | |
610 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
611 | return; | |
612 | ||
ceeddf79 MP |
613 | /* Caching disabled? */ |
614 | if (!t->scope->manager->enable_cache) | |
615 | return; | |
616 | ||
547973de LP |
617 | /* We never cache if this packet is from the local host, under |
618 | * the assumption that a locally running DNS server would | |
619 | * cache this anyway, and probably knows better when to flush | |
620 | * the cache then we could. */ | |
621 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
622 | return; | |
623 | ||
547973de LP |
624 | dns_cache_put(&t->scope->cache, |
625 | t->key, | |
626 | t->answer_rcode, | |
627 | t->answer, | |
547973de | 628 | t->answer_authenticated, |
d3760be0 | 629 | t->answer_nsec_ttl, |
547973de LP |
630 | 0, |
631 | t->received->family, | |
632 | &t->received->sender); | |
633 | } | |
634 | ||
105e1512 LP |
635 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
636 | DnsTransaction *dt; | |
637 | Iterator i; | |
638 | ||
639 | assert(t); | |
640 | ||
641 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
642 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
643 | return true; | |
644 | ||
645 | return false; | |
646 | } | |
647 | ||
942eb2e7 LP |
648 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
649 | DnsTransaction *dt; | |
650 | Iterator i; | |
651 | ||
652 | assert(t); | |
653 | ||
654 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
655 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
656 | ||
657 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
658 | ||
659 | switch (dt->state) { | |
660 | ||
661 | case DNS_TRANSACTION_NULL: | |
662 | case DNS_TRANSACTION_PENDING: | |
663 | case DNS_TRANSACTION_VALIDATING: | |
664 | /* Still ongoing */ | |
665 | return 0; | |
666 | ||
667 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 668 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
669 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
670 | goto fail; | |
671 | } | |
672 | ||
b3c6b00a LP |
673 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
674 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
675 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
676 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
677 | |
678 | case DNS_TRANSACTION_SUCCESS: | |
679 | /* All good. */ | |
680 | break; | |
681 | ||
682 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
683 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
684 | * validationr result */ | |
685 | ||
686 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
687 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
688 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
689 | return 0; | |
690 | ||
691 | ||
692 | default: | |
693 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
694 | goto fail; | |
695 | } | |
696 | } | |
697 | ||
698 | /* All is ready, we can go and validate */ | |
699 | return 1; | |
700 | ||
701 | fail: | |
702 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
703 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
704 | return 0; | |
705 | } | |
706 | ||
547973de LP |
707 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
708 | int r; | |
709 | ||
710 | assert(t); | |
711 | ||
712 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 713 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
714 | if (r < 0) |
715 | goto fail; | |
942eb2e7 | 716 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
717 | return; |
718 | ||
c02cf2f4 LP |
719 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
720 | * restart the lookup immediately. */ | |
721 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
722 | if (r < 0) |
723 | goto fail; | |
c02cf2f4 LP |
724 | if (r > 0) /* Transaction got restarted... */ |
725 | return; | |
726 | ||
547973de LP |
727 | /* All our auxiliary DNSSEC transactions are complete now. Try |
728 | * to validate our RRset now. */ | |
729 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
730 | if (r == -EBADMSG) { |
731 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
732 | return; | |
733 | } | |
7cc6ed7b LP |
734 | if (r < 0) |
735 | goto fail; | |
547973de | 736 | |
b652d4a2 LP |
737 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
738 | t->scope->dnssec_mode == DNSSEC_YES) { | |
739 | /* We are not in automatic downgrade mode, and the | |
740 | * server is bad, refuse operation. */ | |
741 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
742 | return; | |
743 | } | |
744 | ||
019036a4 | 745 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
746 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
747 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
748 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
749 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
750 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
751 | return; | |
752 | } | |
753 | ||
1e02e182 LP |
754 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
755 | dns_server_warn_downgrade(t->server); | |
756 | ||
547973de LP |
757 | dns_transaction_cache_answer(t); |
758 | ||
759 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
760 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
761 | else | |
3bbdc31d | 762 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
763 | |
764 | return; | |
765 | ||
766 | fail: | |
767 | t->answer_errno = -r; | |
768 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
769 | } |
770 | ||
eac7cda2 LP |
771 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
772 | int r; | |
773 | ||
774 | assert(t); | |
775 | ||
776 | /* Checks whether the answer is positive, i.e. either a direct | |
777 | * answer to the question, or a CNAME/DNAME for it */ | |
778 | ||
779 | r = dns_answer_match_key(t->answer, t->key, flags); | |
780 | if (r != 0) | |
781 | return r; | |
782 | ||
783 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
784 | if (r != 0) | |
785 | return r; | |
786 | ||
787 | return false; | |
788 | } | |
789 | ||
790 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
791 | int r; | |
792 | ||
793 | assert(t); | |
794 | ||
795 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
796 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
797 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
798 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
799 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
800 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
801 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
802 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
803 | * incomplete CNAME/DNAME chain. | |
804 | * | |
805 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
806 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
807 | * lookup. */ | |
808 | ||
809 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
810 | return 0; | |
811 | ||
812 | r = dns_transaction_has_positive_answer(t, NULL); | |
813 | if (r <= 0) | |
814 | return r; | |
815 | ||
816 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
817 | return 0; | |
818 | } | |
819 | ||
ec2c5e43 | 820 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 821 | usec_t ts; |
ec2c5e43 LP |
822 | int r; |
823 | ||
824 | assert(t); | |
825 | assert(p); | |
9df3ba6c TG |
826 | assert(t->scope); |
827 | assert(t->scope->manager); | |
ec2c5e43 | 828 | |
5a7e41a3 LP |
829 | if (t->state != DNS_TRANSACTION_PENDING) |
830 | return; | |
831 | ||
ec2c5e43 LP |
832 | /* Note that this call might invalidate the query. Callers |
833 | * should hence not attempt to access the query or transaction | |
834 | * after calling this function. */ | |
835 | ||
1fdeaeb7 | 836 | log_debug("Processing incoming packet on transaction %" PRIu16". (rcode=%s)", t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
b5efcf29 | 837 | |
106784eb | 838 | switch (t->scope->protocol) { |
b5efcf29 | 839 | |
106784eb | 840 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 841 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 842 | |
97ebebbc | 843 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
844 | return; |
845 | ||
846 | if (p->family != t->scope->family) | |
847 | return; | |
848 | ||
849 | /* Tentative packets are not full responses but still | |
850 | * useful for identifying uniqueness conflicts during | |
851 | * probing. */ | |
8b757a38 | 852 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
853 | dns_transaction_tentative(t, p); |
854 | return; | |
855 | } | |
106784eb DM |
856 | |
857 | break; | |
858 | ||
4e5bf5e1 | 859 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 860 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
861 | |
862 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
863 | return; |
864 | ||
865 | if (p->family != t->scope->family) | |
866 | return; | |
867 | ||
868 | break; | |
869 | ||
106784eb | 870 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
871 | /* Note that we do not need to verify the |
872 | * addresses/port numbers of incoming traffic, as we | |
873 | * invoked connect() on our UDP socket in which case | |
874 | * the kernel already does the needed verification for | |
875 | * us. */ | |
106784eb DM |
876 | break; |
877 | ||
878 | default: | |
9c56a6f3 | 879 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
880 | } |
881 | ||
ec2c5e43 LP |
882 | if (t->received != p) { |
883 | dns_packet_unref(t->received); | |
884 | t->received = dns_packet_ref(p); | |
885 | } | |
886 | ||
c3bc53e6 LP |
887 | t->answer_source = DNS_TRANSACTION_NETWORK; |
888 | ||
ec2c5e43 LP |
889 | if (p->ipproto == IPPROTO_TCP) { |
890 | if (DNS_PACKET_TC(p)) { | |
891 | /* Truncated via TCP? Somebody must be fucking with us */ | |
892 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
893 | return; | |
894 | } | |
895 | ||
896 | if (DNS_PACKET_ID(p) != t->id) { | |
897 | /* Not the reply to our query? Somebody must be fucking with us */ | |
898 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
899 | return; | |
900 | } | |
901 | } | |
902 | ||
38a03f06 | 903 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
904 | |
905 | switch (t->scope->protocol) { | |
8af5b883 | 906 | |
9df3ba6c TG |
907 | case DNS_PROTOCOL_DNS: |
908 | assert(t->server); | |
909 | ||
4e0b8b17 TG |
910 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
911 | ||
8af5b883 | 912 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 913 | |
7d581a65 LP |
914 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
915 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade | |
916 | * this transaction anymore, hence let's process the response, and accept the | |
917 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate | |
918 | * packet loss, but is not going to give us better rcodes should we actually have | |
919 | * managed to get them already at UDP level. */ | |
920 | ||
d001e0a3 LP |
921 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
922 | break; | |
923 | } | |
924 | ||
925 | /* Reduce this feature level by one and try again. */ | |
926 | t->clamp_feature_level = t->current_feature_level - 1; | |
927 | ||
928 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
929 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
930 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
931 | ||
932 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 933 | return; |
eb08640a LP |
934 | } |
935 | ||
936 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
937 | /* This server refused our request? If so, try again, use a different server */ | |
938 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
939 | dns_transaction_retry(t, true /* pick a new server */); | |
940 | return; | |
941 | } | |
942 | ||
943 | if (DNS_PACKET_TC(p)) | |
274b8748 | 944 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
945 | |
946 | break; | |
8af5b883 | 947 | |
9df3ba6c TG |
948 | case DNS_PROTOCOL_LLMNR: |
949 | case DNS_PROTOCOL_MDNS: | |
950 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 951 | break; |
8af5b883 | 952 | |
9df3ba6c | 953 | default: |
8af5b883 | 954 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
955 | } |
956 | ||
ec2c5e43 | 957 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
958 | |
959 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
960 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
961 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
962 | return; | |
963 | } | |
964 | ||
f757cd85 LP |
965 | log_debug("Reply truncated, retrying via TCP."); |
966 | ||
ec2c5e43 LP |
967 | /* Response was truncated, let's try again with good old TCP */ |
968 | r = dns_transaction_open_tcp(t); | |
969 | if (r == -ESRCH) { | |
970 | /* No servers found? Damn! */ | |
971 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
972 | return; | |
973 | } | |
91adc4db LP |
974 | if (r == -EOPNOTSUPP) { |
975 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
976 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
977 | return; | |
978 | } | |
ec2c5e43 | 979 | if (r < 0) { |
8af5b883 | 980 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 981 | * we immediately give up */ |
7cc6ed7b LP |
982 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
983 | goto fail; | |
ec2c5e43 LP |
984 | |
985 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 986 | dns_transaction_retry(t, true); |
ec2c5e43 | 987 | } |
2a6658ef LP |
988 | |
989 | return; | |
ec2c5e43 LP |
990 | } |
991 | ||
de54e62b | 992 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
993 | r = dns_packet_extract(p); |
994 | if (r < 0) { | |
995 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
996 | return; | |
997 | } | |
998 | ||
ed9717fc | 999 | if (t->server) { |
d001e0a3 LP |
1000 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1001 | * rcode and subsequently downgraded the protocol */ | |
1002 | ||
1003 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1004 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1005 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1006 | ||
1007 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1008 | if (!p->opt) |
1009 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1010 | ||
d001e0a3 | 1011 | /* Report that we successfully received a packet */ |
ed9717fc LP |
1012 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); |
1013 | } | |
de54e62b | 1014 | |
c02cf2f4 LP |
1015 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1016 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1017 | if (r < 0) |
1018 | goto fail; | |
c02cf2f4 LP |
1019 | if (r > 0) /* Transaction got restarted... */ |
1020 | return; | |
1021 | ||
8b419837 | 1022 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
b5efcf29 | 1023 | |
8b419837 DR |
1024 | /* When dealing with protocols other than mDNS only consider responses with |
1025 | * equivalent query section to the request. For mDNS this check doesn't make | |
1026 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1027 | * contain any questions in the Question Section". */ | |
1028 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1029 | r = dns_packet_is_reply_for(p, t->key); | |
1030 | if (r < 0) | |
1031 | goto fail; | |
1032 | if (r == 0) { | |
1033 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1034 | return; | |
1035 | } | |
547493c5 | 1036 | } |
29815b6c | 1037 | |
547493c5 DM |
1038 | /* Install the answer as answer to the transaction */ |
1039 | dns_answer_unref(t->answer); | |
1040 | t->answer = dns_answer_ref(p->answer); | |
1041 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1042 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1043 | t->answer_authenticated = false; |
79e24931 | 1044 | |
eac7cda2 LP |
1045 | r = dns_transaction_fix_rcode(t); |
1046 | if (r < 0) | |
1047 | goto fail; | |
1048 | ||
51e399bc LP |
1049 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1050 | t->block_gc++; | |
547973de | 1051 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1052 | t->block_gc--; |
1053 | ||
1054 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1055 | if (!dns_transaction_gc(t)) | |
1056 | return; | |
1057 | ||
1058 | /* Requesting additional keys might have resulted in | |
1059 | * this transaction to fail, since the auxiliary | |
1060 | * request failed for some reason. If so, we are not | |
1061 | * in pending state anymore, and we should exit | |
1062 | * quickly. */ | |
1063 | if (t->state != DNS_TRANSACTION_PENDING) | |
1064 | return; | |
7cc6ed7b LP |
1065 | if (r < 0) |
1066 | goto fail; | |
547973de LP |
1067 | if (r > 0) { |
1068 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1069 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1070 | dns_transaction_close_connection(t); |
1071 | dns_transaction_stop_timeout(t); | |
547973de LP |
1072 | return; |
1073 | } | |
547493c5 | 1074 | } |
ec2c5e43 | 1075 | |
547973de | 1076 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1077 | return; |
1078 | ||
1079 | fail: | |
1080 | t->answer_errno = -r; | |
1081 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1082 | } |
1083 | ||
c19ffd9f TG |
1084 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1085 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1086 | DnsTransaction *t = userdata; | |
1087 | int r; | |
1088 | ||
1089 | assert(t); | |
1090 | assert(t->scope); | |
1091 | ||
1092 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1093 | if (ERRNO_IS_DISCONNECT(-r)) { |
1094 | usec_t usec; | |
c19ffd9f | 1095 | |
7e1851e3 LP |
1096 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1097 | * recvmsg(). Treat this like a lost packet. */ | |
1098 | ||
92ec902a | 1099 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1100 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1101 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 | 1102 | |
d001e0a3 | 1103 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1104 | return 0; |
1105 | } | |
1106 | if (r < 0) { | |
7cc6ed7b LP |
1107 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1108 | t->answer_errno = -r; | |
7e1851e3 LP |
1109 | return 0; |
1110 | } | |
1111 | ||
1112 | r = dns_packet_validate_reply(p); | |
1113 | if (r < 0) { | |
1114 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1115 | return 0; | |
1116 | } | |
1117 | if (r == 0) { | |
e09f605e | 1118 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1119 | return 0; |
1120 | } | |
1121 | ||
1122 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1123 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1124 | return 0; |
1125 | } | |
c19ffd9f | 1126 | |
7e1851e3 | 1127 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1128 | return 0; |
1129 | } | |
1130 | ||
49cce12d | 1131 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1132 | int r; |
1133 | ||
1134 | assert(t); | |
c19ffd9f | 1135 | |
519ef046 | 1136 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1137 | |
519ef046 | 1138 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1139 | if (r < 0) |
1140 | return r; | |
c19ffd9f | 1141 | |
274b8748 | 1142 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
7d581a65 | 1143 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1144 | |
92ec902a | 1145 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1146 | return -EOPNOTSUPP; |
1147 | ||
519ef046 LP |
1148 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1149 | int fd; | |
1150 | ||
1151 | dns_transaction_close_connection(t); | |
c19ffd9f | 1152 | |
519ef046 LP |
1153 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1154 | if (fd < 0) | |
1155 | return fd; | |
1156 | ||
1157 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1158 | if (r < 0) { | |
1159 | safe_close(fd); | |
1160 | return r; | |
1161 | } | |
1162 | ||
aa4a9deb | 1163 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1164 | t->dns_udp_fd = fd; |
1165 | } | |
1166 | ||
274b8748 | 1167 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1168 | if (r < 0) |
1169 | return r; | |
1170 | } else | |
1171 | dns_transaction_close_connection(t); | |
1172 | ||
1173 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1174 | if (r < 0) |
1175 | return r; | |
c19ffd9f | 1176 | |
519ef046 | 1177 | dns_transaction_reset_answer(t); |
be808ea0 | 1178 | |
471d40d9 | 1179 | return 0; |
c19ffd9f TG |
1180 | } |
1181 | ||
ec2c5e43 LP |
1182 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1183 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1184 | |
1185 | assert(s); | |
1186 | assert(t); | |
1187 | ||
ef7ce6df DM |
1188 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1189 | /* Timeout reached? Increase the timeout for the server used */ | |
1190 | switch (t->scope->protocol) { | |
49cce12d | 1191 | |
ef7ce6df DM |
1192 | case DNS_PROTOCOL_DNS: |
1193 | assert(t->server); | |
274b8748 | 1194 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1195 | break; |
49cce12d | 1196 | |
ef7ce6df DM |
1197 | case DNS_PROTOCOL_LLMNR: |
1198 | case DNS_PROTOCOL_MDNS: | |
1199 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1200 | break; |
49cce12d | 1201 | |
ef7ce6df DM |
1202 | default: |
1203 | assert_not_reached("Invalid DNS protocol."); | |
1204 | } | |
1205 | ||
1206 | if (t->initial_jitter_scheduled) | |
1207 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1208 | } |
1209 | ||
423659ab LP |
1210 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1211 | ||
d001e0a3 | 1212 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1213 | return 0; |
1214 | } | |
1215 | ||
9df3ba6c TG |
1216 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1217 | assert(t); | |
1218 | assert(t->scope); | |
1219 | ||
dc349f5f | 1220 | |
9df3ba6c | 1221 | switch (t->scope->protocol) { |
49cce12d | 1222 | |
9df3ba6c | 1223 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1224 | |
1225 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1226 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1227 | * needlessly. */ | |
1228 | if (t->stream) | |
1229 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1230 | ||
9df3ba6c | 1231 | assert(t->server); |
9df3ba6c | 1232 | return t->server->resend_timeout; |
49cce12d | 1233 | |
9df3ba6c | 1234 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1235 | assert(t->n_attempts > 0); |
53fda2bb DR |
1236 | if (t->probing) |
1237 | return MDNS_PROBING_INTERVAL_USEC; | |
1238 | else | |
1239 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1240 | |
11a27c2e | 1241 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1242 | return t->scope->resend_timeout; |
49cce12d | 1243 | |
9df3ba6c TG |
1244 | default: |
1245 | assert_not_reached("Invalid DNS protocol."); | |
1246 | } | |
1247 | } | |
1248 | ||
c842ff24 | 1249 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1250 | int r; |
1251 | ||
1252 | assert(t); | |
1253 | ||
f535705a | 1254 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1255 | |
edbcc1fd LP |
1256 | r = dns_scope_network_good(t->scope); |
1257 | if (r < 0) | |
1258 | return r; | |
1259 | if (r == 0) { | |
1260 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1261 | return 0; | |
1262 | } | |
1263 | ||
ec2c5e43 LP |
1264 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1265 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1266 | return 0; | |
1267 | } | |
1268 | ||
cbe4216d | 1269 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1270 | /* If we already tried via a stream, then we don't |
1271 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1272 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1273 | return 0; | |
1274 | } | |
1275 | ||
1276 | t->n_attempts++; | |
9df3ba6c | 1277 | t->start_usec = ts; |
c61d2b44 LP |
1278 | |
1279 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1280 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1281 | |
0d2cd476 LP |
1282 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1283 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1284 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1285 | if (r < 0) |
1286 | return r; | |
1287 | if (r > 0) { | |
1288 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1289 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1290 | t->answer_authenticated = true; |
0d2cd476 LP |
1291 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1292 | return 0; | |
1293 | } | |
b2b796b8 | 1294 | |
1c02e7ba | 1295 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1296 | t->key->type == DNS_TYPE_DS) { |
1297 | ||
1298 | /* Hmm, this is a request for the root DS? A | |
1299 | * DS RR doesn't exist in the root zone, and | |
1300 | * if our trust anchor didn't know it either, | |
1301 | * this means we cannot do any DNSSEC logic | |
1302 | * anymore. */ | |
1303 | ||
1ed8c0fb | 1304 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1305 | /* We are in downgrade mode. In this |
1306 | * case, synthesize an unsigned empty | |
1307 | * response, so that the any lookup | |
1308 | * depending on this one can continue | |
1309 | * assuming there was no DS, and hence | |
1310 | * the root zone was unsigned. */ | |
1311 | ||
1312 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1313 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1314 | t->answer_authenticated = false; | |
1315 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1316 | } else | |
1317 | /* If we are not in downgrade mode, | |
1318 | * then fail the lookup, because we | |
1319 | * cannot reasonably answer it. There | |
1320 | * might be DS RRs, but we don't know | |
1321 | * them, and the DNS server won't tell | |
1322 | * them to us (and even if it would, | |
202b76ae | 1323 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1324 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1325 | ||
1326 | return 0; | |
1327 | } | |
0d2cd476 LP |
1328 | } |
1329 | ||
1330 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1331 | * for probing or verifying a zone item. */ |
547973de | 1332 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1333 | |
97ebebbc | 1334 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1335 | if (r < 0) |
1336 | return r; | |
1337 | if (r > 0) { | |
ae6a4bbf | 1338 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1339 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1340 | t->answer_authenticated = true; |
d746bb3e LP |
1341 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1342 | return 0; | |
1343 | } | |
1344 | } | |
1345 | ||
4d926a69 LP |
1346 | /* Check the cache, but only if this transaction is not used |
1347 | * for probing or verifying a zone item. */ | |
547973de | 1348 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1349 | |
4d926a69 LP |
1350 | /* Before trying the cache, let's make sure we figured out a |
1351 | * server to use. Should this cause a change of server this | |
1352 | * might flush the cache. */ | |
1353 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 1354 | |
4d926a69 LP |
1355 | /* Let's then prune all outdated entries */ |
1356 | dns_cache_prune(&t->scope->cache); | |
1357 | ||
17c8de63 | 1358 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1359 | if (r < 0) |
1360 | return r; | |
1361 | if (r > 0) { | |
c3bc53e6 | 1362 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1363 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1364 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1365 | else | |
3bbdc31d | 1366 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1367 | return 0; |
1368 | } | |
ec2c5e43 LP |
1369 | } |
1370 | ||
1effe965 DM |
1371 | return 1; |
1372 | } | |
1373 | ||
0afa57e2 DM |
1374 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1375 | ||
1376 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1377 | bool add_known_answers = false; |
0afa57e2 DM |
1378 | DnsTransaction *other; |
1379 | unsigned qdcount; | |
1380 | usec_t ts; | |
1381 | int r; | |
1382 | ||
1383 | assert(t); | |
1384 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1385 | ||
e5abebab | 1386 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1387 | t->sent = dns_packet_unref(t->sent); |
1388 | ||
1389 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1390 | if (r < 0) | |
1391 | return r; | |
1392 | ||
58ab31d5 | 1393 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1394 | if (r < 0) |
1395 | return r; | |
1396 | ||
1397 | qdcount = 1; | |
1398 | ||
7778dfff DM |
1399 | if (dns_key_is_shared(t->key)) |
1400 | add_known_answers = true; | |
1401 | ||
0afa57e2 DM |
1402 | /* |
1403 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1404 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1405 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1406 | */ | |
1407 | ||
1408 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1409 | ||
1410 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1411 | ||
1412 | /* Skip ourselves */ | |
1413 | if (other == t) | |
1414 | continue; | |
1415 | ||
1416 | if (other->state != DNS_TRANSACTION_PENDING) | |
1417 | continue; | |
1418 | ||
1419 | if (other->next_attempt_after > ts) | |
1420 | continue; | |
1421 | ||
1422 | if (qdcount >= UINT16_MAX) | |
1423 | break; | |
1424 | ||
58ab31d5 | 1425 | r = dns_packet_append_key(p, other->key, 0, NULL); |
0afa57e2 DM |
1426 | |
1427 | /* | |
1428 | * If we can't stuff more questions into the packet, just give up. | |
1429 | * One of the 'other' transactions will fire later and take care of the rest. | |
1430 | */ | |
1431 | if (r == -EMSGSIZE) | |
1432 | break; | |
1433 | ||
1434 | if (r < 0) | |
1435 | return r; | |
1436 | ||
c842ff24 | 1437 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1438 | if (r <= 0) |
1439 | continue; | |
1440 | ||
1441 | ts += transaction_get_resend_timeout(other); | |
1442 | ||
1443 | r = sd_event_add_time( | |
1444 | other->scope->manager->event, | |
1445 | &other->timeout_event_source, | |
1446 | clock_boottime_or_monotonic(), | |
1447 | ts, 0, | |
1448 | on_transaction_timeout, other); | |
1449 | if (r < 0) | |
1450 | return r; | |
1451 | ||
ff537038 | 1452 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1453 | |
0afa57e2 DM |
1454 | other->state = DNS_TRANSACTION_PENDING; |
1455 | other->next_attempt_after = ts; | |
1456 | ||
313cefa1 | 1457 | qdcount++; |
7778dfff DM |
1458 | |
1459 | if (dns_key_is_shared(other->key)) | |
1460 | add_known_answers = true; | |
0afa57e2 DM |
1461 | } |
1462 | ||
1463 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1464 | |
7778dfff DM |
1465 | /* Append known answer section if we're asking for any shared record */ |
1466 | if (add_known_answers) { | |
1467 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1468 | if (r < 0) | |
1469 | return r; | |
1470 | } | |
1471 | ||
0afa57e2 DM |
1472 | t->sent = p; |
1473 | p = NULL; | |
1474 | ||
1475 | return 0; | |
1476 | } | |
1477 | ||
1478 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1479 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1480 | int r; | |
1481 | ||
1482 | assert(t); | |
1483 | ||
1484 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1485 | return dns_transaction_make_packet_mdns(t); | |
1486 | ||
1487 | if (t->sent) | |
1488 | return 0; | |
1489 | ||
b652d4a2 | 1490 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1491 | if (r < 0) |
1492 | return r; | |
1493 | ||
58ab31d5 | 1494 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1495 | if (r < 0) |
1496 | return r; | |
1497 | ||
1498 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1499 | DNS_PACKET_HEADER(p)->id = t->id; | |
1500 | ||
1501 | t->sent = p; | |
1502 | p = NULL; | |
1503 | ||
1504 | return 0; | |
1505 | } | |
1506 | ||
1effe965 DM |
1507 | int dns_transaction_go(DnsTransaction *t) { |
1508 | usec_t ts; | |
1509 | int r; | |
202b76ae | 1510 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1511 | |
1512 | assert(t); | |
1513 | ||
5278bbfe LP |
1514 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1515 | * now. */ | |
1516 | ||
1effe965 | 1517 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1518 | |
c842ff24 | 1519 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1520 | if (r <= 0) |
1521 | return r; | |
1522 | ||
202b76ae | 1523 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1524 | t->id, |
202b76ae | 1525 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1526 | dns_protocol_to_string(t->scope->protocol), |
1527 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1528 | af_to_name_short(t->scope->family)); |
1effe965 | 1529 | |
ef7ce6df | 1530 | if (!t->initial_jitter_scheduled && |
3742095b | 1531 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1532 | usec_t jitter, accuracy; |
6e068472 LP |
1533 | |
1534 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1535 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1536 | ||
ef7ce6df | 1537 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1538 | |
1539 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1540 | |
1541 | switch (t->scope->protocol) { | |
519ef046 | 1542 | |
ea12bcc7 DM |
1543 | case DNS_PROTOCOL_LLMNR: |
1544 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1545 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1546 | break; | |
519ef046 | 1547 | |
ea12bcc7 DM |
1548 | case DNS_PROTOCOL_MDNS: |
1549 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1550 | jitter += MDNS_JITTER_MIN_USEC; | |
1551 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1552 | break; | |
1553 | default: | |
1554 | assert_not_reached("bad protocol"); | |
1555 | } | |
6e068472 LP |
1556 | |
1557 | r = sd_event_add_time( | |
1558 | t->scope->manager->event, | |
1559 | &t->timeout_event_source, | |
1560 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1561 | ts + jitter, accuracy, |
6e068472 LP |
1562 | on_transaction_timeout, t); |
1563 | if (r < 0) | |
1564 | return r; | |
1565 | ||
aa4a9deb LP |
1566 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1567 | ||
6e068472 | 1568 | t->n_attempts = 0; |
a9da14e1 | 1569 | t->next_attempt_after = ts; |
6e068472 LP |
1570 | t->state = DNS_TRANSACTION_PENDING; |
1571 | ||
ea12bcc7 | 1572 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1573 | return 0; |
1574 | } | |
1575 | ||
ec2c5e43 LP |
1576 | /* Otherwise, we need to ask the network */ |
1577 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1578 | if (r < 0) |
1579 | return r; | |
1580 | ||
1581 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1582 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1583 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1584 | |
1585 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1586 | * always be made via TCP on LLMNR */ | |
1587 | r = dns_transaction_open_tcp(t); | |
1588 | } else { | |
be808ea0 TG |
1589 | /* Try via UDP, and if that fails due to large size or lack of |
1590 | * support try via TCP */ | |
49cce12d | 1591 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1592 | if (r == -EMSGSIZE) |
1593 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1594 | else if (r == -EAGAIN) |
034e8031 | 1595 | log_debug("Sending query via TCP since server doesn't support UDP."); |
4c701096 | 1596 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
ec2c5e43 LP |
1597 | r = dns_transaction_open_tcp(t); |
1598 | } | |
be808ea0 | 1599 | |
ec2c5e43 LP |
1600 | if (r == -ESRCH) { |
1601 | /* No servers to send this to? */ | |
1602 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1603 | return 0; | |
91adc4db LP |
1604 | } |
1605 | if (r == -EOPNOTSUPP) { | |
1606 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1607 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1608 | return 0; | |
1609 | } | |
0791110f | 1610 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1611 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1612 | * answer this request with this protocol. */ |
1613 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1614 | return 0; | |
1615 | } | |
91adc4db | 1616 | if (r < 0) { |
7cc6ed7b LP |
1617 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1618 | return r; | |
13b551ac | 1619 | |
ec2c5e43 | 1620 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1621 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1622 | |
1623 | return dns_transaction_go(t); | |
1624 | } | |
1625 | ||
a9da14e1 DM |
1626 | ts += transaction_get_resend_timeout(t); |
1627 | ||
9a015429 LP |
1628 | r = sd_event_add_time( |
1629 | t->scope->manager->event, | |
1630 | &t->timeout_event_source, | |
1631 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1632 | ts, 0, |
9a015429 | 1633 | on_transaction_timeout, t); |
ec2c5e43 LP |
1634 | if (r < 0) |
1635 | return r; | |
1636 | ||
aa4a9deb LP |
1637 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1638 | ||
ec2c5e43 | 1639 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1640 | t->next_attempt_after = ts; |
1641 | ||
ec2c5e43 LP |
1642 | return 1; |
1643 | } | |
1644 | ||
f2992dc1 LP |
1645 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1646 | DnsTransaction *n; | |
1647 | Iterator i; | |
1648 | int r; | |
1649 | ||
1650 | assert(t); | |
1651 | assert(aux); | |
1652 | ||
1653 | /* Try to find cyclic dependencies between transaction objects */ | |
1654 | ||
1655 | if (t == aux) | |
1656 | return 1; | |
1657 | ||
3eb6aa00 | 1658 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1659 | r = dns_transaction_find_cyclic(t, n); |
1660 | if (r != 0) | |
1661 | return r; | |
1662 | } | |
1663 | ||
3eb6aa00 | 1664 | return 0; |
f2992dc1 LP |
1665 | } |
1666 | ||
547973de LP |
1667 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1668 | DnsTransaction *aux; | |
1669 | int r; | |
1670 | ||
1671 | assert(t); | |
1672 | assert(ret); | |
1673 | assert(key); | |
1674 | ||
1675 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1676 | if (!aux) { | |
1677 | r = dns_transaction_new(&aux, t->scope, key); | |
1678 | if (r < 0) | |
1679 | return r; | |
1680 | } else { | |
1681 | if (set_contains(t->dnssec_transactions, aux)) { | |
1682 | *ret = aux; | |
1683 | return 0; | |
1684 | } | |
f2992dc1 LP |
1685 | |
1686 | r = dns_transaction_find_cyclic(t, aux); | |
1687 | if (r < 0) | |
1688 | return r; | |
1689 | if (r > 0) { | |
202b76ae ZJS |
1690 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1691 | ||
1692 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1693 | aux->id, |
202b76ae | 1694 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1695 | t->id, |
202b76ae ZJS |
1696 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1697 | ||
f2992dc1 LP |
1698 | return -ELOOP; |
1699 | } | |
547973de LP |
1700 | } |
1701 | ||
1702 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1703 | if (r < 0) | |
1704 | goto gc; | |
1705 | ||
1706 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1707 | if (r < 0) | |
35aa04e9 LP |
1708 | goto gc; |
1709 | ||
1710 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1711 | if (r < 0) | |
547973de LP |
1712 | goto gc; |
1713 | ||
1714 | r = set_put(t->dnssec_transactions, aux); | |
1715 | if (r < 0) | |
1716 | goto gc; | |
1717 | ||
1718 | r = set_put(aux->notify_transactions, t); | |
1719 | if (r < 0) { | |
1720 | (void) set_remove(t->dnssec_transactions, aux); | |
1721 | goto gc; | |
1722 | } | |
1723 | ||
1724 | *ret = aux; | |
1725 | return 1; | |
1726 | ||
1727 | gc: | |
1728 | dns_transaction_gc(aux); | |
1729 | return r; | |
1730 | } | |
1731 | ||
1732 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1733 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1734 | DnsTransaction *aux; | |
1735 | int r; | |
1736 | ||
1737 | assert(t); | |
1738 | assert(key); | |
1739 | ||
1740 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1741 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1742 | if (r < 0) |
1743 | return r; | |
1744 | if (r > 0) { | |
1745 | r = dns_answer_extend(&t->validated_keys, a); | |
1746 | if (r < 0) | |
1747 | return r; | |
1748 | ||
1749 | return 0; | |
1750 | } | |
1751 | ||
1752 | /* This didn't work, ask for it via the network/cache then. */ | |
1753 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1754 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1755 | return 0; | |
547973de LP |
1756 | if (r < 0) |
1757 | return r; | |
1758 | ||
1759 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1760 | r = dns_transaction_go(aux); | |
1761 | if (r < 0) | |
1762 | return r; | |
1763 | } | |
1764 | ||
f2992dc1 | 1765 | return 1; |
547973de LP |
1766 | } |
1767 | ||
8a516214 LP |
1768 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1769 | int r; | |
1770 | ||
1771 | assert(t); | |
1772 | ||
c629ff58 | 1773 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1774 | * database, either in the global one, or the link-local |
1775 | * one. */ | |
1776 | ||
1777 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1778 | if (r != 0) | |
1779 | return r; | |
1780 | ||
1781 | if (!t->scope->link) | |
1782 | return 0; | |
1783 | ||
1784 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1785 | } | |
1786 | ||
105e1512 LP |
1787 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1788 | int r; | |
1789 | ||
1790 | assert(t); | |
1791 | ||
1792 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1793 | * RRs to prove it */ | |
1794 | ||
1795 | r = dns_transaction_has_positive_answer(t, NULL); | |
1796 | if (r < 0) | |
1797 | return r; | |
1798 | if (r > 0) | |
1799 | return false; | |
1800 | ||
8e54f5d9 LP |
1801 | /* Is this key explicitly listed as a negative trust anchor? |
1802 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1803 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1804 | if (r < 0) |
1805 | return r; | |
1806 | if (r > 0) | |
1807 | return false; | |
1808 | ||
105e1512 LP |
1809 | /* The answer does not contain any RRs that match to the |
1810 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1811 | * included. If not, the answer is unsigned. */ | |
1812 | ||
1813 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1814 | if (r < 0) | |
1815 | return r; | |
1816 | if (r > 0) | |
1817 | return false; | |
1818 | ||
1819 | return true; | |
1820 | } | |
1821 | ||
1822 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1823 | int r; | |
1824 | ||
1825 | assert(t); | |
1826 | assert(rr); | |
1827 | ||
1828 | /* Check if the specified RR is the "primary" response, | |
1829 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1830 | * CNAME/DNAME for it. */ |
105e1512 LP |
1831 | |
1832 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1833 | if (r != 0) | |
1834 | return r; | |
1835 | ||
4cb94977 | 1836 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1837 | } |
1838 | ||
92ec902a LP |
1839 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1840 | assert(t); | |
1841 | ||
1842 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1843 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1844 | ||
1845 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1846 | return false; | |
1847 | ||
1848 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1849 | * be supported, hence return true. */ | |
1850 | if (!t->server) | |
1851 | return true; | |
1852 | ||
d001e0a3 LP |
1853 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1854 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1855 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1856 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1857 | |
1858 | return dns_server_dnssec_supported(t->server); | |
1859 | } | |
1860 | ||
1861 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1862 | DnsTransaction *dt; | |
1863 | Iterator i; | |
1864 | ||
1865 | assert(t); | |
1866 | ||
1867 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1868 | ||
1869 | if (!dns_transaction_dnssec_supported(t)) | |
1870 | return false; | |
1871 | ||
1872 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1873 | if (!dns_transaction_dnssec_supported(dt)) | |
1874 | return false; | |
1875 | ||
1876 | return true; | |
1877 | } | |
1878 | ||
547973de LP |
1879 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1880 | DnsResourceRecord *rr; | |
105e1512 | 1881 | |
547973de LP |
1882 | int r; |
1883 | ||
1884 | assert(t); | |
1885 | ||
105e1512 LP |
1886 | /* |
1887 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1888 | * we can verify signatures or prove that RRs are rightfully | |
1889 | * unsigned. Specifically: | |
1890 | * | |
1891 | * - For RRSIG we get the matching DNSKEY | |
1892 | * - For DNSKEY we get the matching DS | |
1893 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1894 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 1895 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
1896 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
1897 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
1898 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
1899 | */ | |
1900 | ||
b652d4a2 | 1901 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1902 | return 0; |
92ec902a LP |
1903 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1904 | return 0; /* We only need to validate stuff from the network */ | |
1905 | if (!dns_transaction_dnssec_supported(t)) | |
1906 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1907 | |
547973de LP |
1908 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1909 | ||
105e1512 LP |
1910 | if (dns_type_is_pseudo(rr->key->type)) |
1911 | continue; | |
1912 | ||
8e54f5d9 | 1913 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 1914 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
1915 | if (r < 0) |
1916 | return r; | |
1917 | if (r > 0) | |
1918 | continue; | |
1919 | ||
547973de LP |
1920 | switch (rr->key->type) { |
1921 | ||
1922 | case DNS_TYPE_RRSIG: { | |
1923 | /* For each RRSIG we request the matching DNSKEY */ | |
1924 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1925 | ||
1926 | /* If this RRSIG is about a DNSKEY RR and the | |
1927 | * signer is the same as the owner, then we | |
1928 | * already have the DNSKEY, and we don't have | |
1929 | * to look for more. */ | |
1930 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 1931 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
1932 | if (r < 0) |
1933 | return r; | |
1934 | if (r > 0) | |
1935 | continue; | |
1936 | } | |
1937 | ||
105e1512 LP |
1938 | /* If the signer is not a parent of our |
1939 | * original query, then this is about an | |
1940 | * auxiliary RRset, but not anything we asked | |
1941 | * for. In this case we aren't interested, | |
1942 | * because we don't want to request additional | |
1943 | * RRs for stuff we didn't really ask for, and | |
1944 | * also to avoid request loops, where | |
1945 | * additional RRs from one transaction result | |
1946 | * in another transaction whose additonal RRs | |
1947 | * point back to the original transaction, and | |
1948 | * we deadlock. */ | |
1c02e7ba | 1949 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
1950 | if (r < 0) |
1951 | return r; | |
1952 | if (r == 0) | |
1953 | continue; | |
1954 | ||
1955 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1956 | if (!dnskey) | |
1957 | return -ENOMEM; | |
1958 | ||
1c02e7ba ZJS |
1959 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
1960 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
1961 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1962 | if (r < 0) | |
1963 | return r; | |
1964 | break; | |
1965 | } | |
1966 | ||
1967 | case DNS_TYPE_DNSKEY: { | |
1968 | /* For each DNSKEY we request the matching DS */ | |
1969 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1970 | ||
105e1512 LP |
1971 | /* If the DNSKEY we are looking at is not for |
1972 | * zone we are interested in, nor any of its | |
1973 | * parents, we aren't interested, and don't | |
1974 | * request it. After all, we don't want to end | |
1975 | * up in request loops, and want to keep | |
1976 | * additional traffic down. */ | |
1977 | ||
1c02e7ba | 1978 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
1979 | if (r < 0) |
1980 | return r; | |
1981 | if (r == 0) | |
1982 | continue; | |
1983 | ||
1c02e7ba | 1984 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
1985 | if (!ds) |
1986 | return -ENOMEM; | |
1987 | ||
1c02e7ba ZJS |
1988 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
1989 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
1990 | r = dns_transaction_request_dnssec_rr(t, ds); |
1991 | if (r < 0) | |
1992 | return r; | |
547973de | 1993 | |
105e1512 LP |
1994 | break; |
1995 | } | |
1996 | ||
105e1512 LP |
1997 | case DNS_TYPE_SOA: |
1998 | case DNS_TYPE_NS: { | |
1999 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2000 | ||
2001 | /* For an unsigned SOA or NS, try to acquire | |
2002 | * the matching DS RR, as we are at a zone cut | |
2003 | * then, and whether a DS exists tells us | |
2004 | * whether the zone is signed. Do so only if | |
2005 | * this RR matches our original question, | |
2006 | * however. */ | |
2007 | ||
2008 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
2009 | if (r < 0) | |
2010 | return r; | |
6993d264 LP |
2011 | if (r == 0) { |
2012 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
2013 | * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry? | |
2014 | * If so, we need to validate it, too. */ | |
2015 | ||
2016 | r = dns_answer_match_key(t->answer, t->key, NULL); | |
2017 | if (r < 0) | |
2018 | return r; | |
2019 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2020 | * it. */ | |
2021 | continue; | |
2022 | } | |
105e1512 LP |
2023 | |
2024 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2025 | if (r < 0) | |
2026 | return r; | |
2027 | if (r > 0) | |
2028 | continue; | |
2029 | ||
1c02e7ba | 2030 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2031 | if (!ds) |
2032 | return -ENOMEM; | |
2033 | ||
1c02e7ba ZJS |
2034 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2035 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2036 | r = dns_transaction_request_dnssec_rr(t, ds); |
2037 | if (r < 0) | |
2038 | return r; | |
2039 | ||
2040 | break; | |
105e1512 LP |
2041 | } |
2042 | ||
b63fca62 | 2043 | case DNS_TYPE_DS: |
105e1512 LP |
2044 | case DNS_TYPE_CNAME: |
2045 | case DNS_TYPE_DNAME: { | |
2046 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2047 | const char *name; | |
2048 | ||
2049 | /* CNAMEs and DNAMEs cannot be located at a | |
2050 | * zone apex, hence ask for the parent SOA for | |
2051 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2052 | * apex. But do all that only if this is | |
2053 | * actually a response to our original | |
b63fca62 LP |
2054 | * question. |
2055 | * | |
2056 | * Similar for DS RRs, which are signed when | |
2057 | * the parent SOA is signed. */ | |
105e1512 LP |
2058 | |
2059 | r = dns_transaction_is_primary_response(t, rr); | |
2060 | if (r < 0) | |
2061 | return r; | |
2062 | if (r == 0) | |
2063 | continue; | |
2064 | ||
2065 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2066 | if (r < 0) | |
2067 | return r; | |
2068 | if (r > 0) | |
2069 | continue; | |
2070 | ||
43e6779a LP |
2071 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2072 | if (r < 0) | |
2073 | return r; | |
2074 | if (r > 0) | |
2075 | continue; | |
2076 | ||
1c02e7ba | 2077 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2078 | r = dns_name_parent(&name); |
2079 | if (r < 0) | |
2080 | return r; | |
2081 | if (r == 0) | |
2082 | continue; | |
2083 | ||
2084 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2085 | if (!soa) | |
2086 | return -ENOMEM; | |
2087 | ||
1c02e7ba ZJS |
2088 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2089 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2090 | r = dns_transaction_request_dnssec_rr(t, soa); |
2091 | if (r < 0) | |
2092 | return r; | |
2093 | ||
2094 | break; | |
2095 | } | |
2096 | ||
2097 | default: { | |
2098 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2099 | ||
b63fca62 LP |
2100 | /* For other unsigned RRsets (including |
2101 | * NSEC/NSEC3!), look for proof the zone is | |
2102 | * unsigned, by requesting the SOA RR of the | |
2103 | * zone. However, do so only if they are | |
2104 | * directly relevant to our original | |
105e1512 LP |
2105 | * question. */ |
2106 | ||
2107 | r = dns_transaction_is_primary_response(t, rr); | |
2108 | if (r < 0) | |
2109 | return r; | |
2110 | if (r == 0) | |
2111 | continue; | |
2112 | ||
2113 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2114 | if (r < 0) | |
2115 | return r; | |
2116 | if (r > 0) | |
2117 | continue; | |
2118 | ||
1c02e7ba | 2119 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2120 | if (!soa) |
2121 | return -ENOMEM; | |
2122 | ||
1c02e7ba ZJS |
2123 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2124 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2125 | r = dns_transaction_request_dnssec_rr(t, soa); |
2126 | if (r < 0) | |
2127 | return r; | |
2128 | break; | |
547973de LP |
2129 | }} |
2130 | } | |
2131 | ||
105e1512 LP |
2132 | /* Above, we requested everything necessary to validate what |
2133 | * we got. Now, let's request what we need to validate what we | |
2134 | * didn't get... */ | |
2135 | ||
2136 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2137 | if (r < 0) | |
2138 | return r; | |
2139 | if (r > 0) { | |
2140 | const char *name; | |
4bbc06cc | 2141 | uint16_t type = 0; |
105e1512 | 2142 | |
1c02e7ba | 2143 | name = dns_resource_key_name(t->key); |
105e1512 | 2144 | |
4bbc06cc LP |
2145 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2146 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2147 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2148 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2149 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2150 | * to see if that is signed. */ | |
105e1512 | 2151 | |
4bbc06cc | 2152 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2153 | r = dns_name_parent(&name); |
4bbc06cc LP |
2154 | if (r > 0) { |
2155 | type = DNS_TYPE_SOA; | |
2156 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2157 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2158 | } else |
105e1512 | 2159 | name = NULL; |
4bbc06cc LP |
2160 | |
2161 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2162 | ||
2163 | type = DNS_TYPE_DS; | |
2164 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2165 | t->id, dns_resource_key_name(t->key)); | |
2166 | ||
2167 | } else { | |
2168 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2169 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2170 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2171 | } |
105e1512 LP |
2172 | |
2173 | if (name) { | |
2174 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2175 | ||
4bbc06cc | 2176 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2177 | if (!soa) |
2178 | return -ENOMEM; | |
2179 | ||
2180 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2181 | if (r < 0) | |
2182 | return r; | |
2183 | } | |
2184 | } | |
2185 | ||
2186 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2187 | } |
2188 | ||
2189 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2190 | assert(t); |
547973de LP |
2191 | assert(source); |
2192 | ||
942eb2e7 LP |
2193 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2194 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2195 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2196 | |
942eb2e7 LP |
2197 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2198 | dns_transaction_process_dnssec(t); | |
547973de LP |
2199 | } |
2200 | ||
105e1512 LP |
2201 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2202 | DnsResourceRecord *rr; | |
2203 | int ifindex, r; | |
2204 | ||
2205 | assert(t); | |
2206 | ||
2207 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2208 | * RRs from the list of validated keys to the list of | |
2209 | * validated keys. */ | |
2210 | ||
2211 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2212 | ||
96bb7673 | 2213 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2214 | if (r < 0) |
2215 | return r; | |
2216 | if (r == 0) | |
2217 | continue; | |
2218 | ||
2219 | /* If so, the DNSKEY is validated too. */ | |
2220 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2221 | if (r < 0) | |
2222 | return r; | |
2223 | } | |
2224 | ||
2225 | return 0; | |
2226 | } | |
2227 | ||
2228 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2229 | int r; |
2230 | ||
2231 | assert(t); | |
2232 | assert(rr); | |
2233 | ||
105e1512 LP |
2234 | /* Checks if the RR we are looking for must be signed with an |
2235 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2236 | |
b652d4a2 | 2237 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2238 | return false; |
56352fe9 | 2239 | |
105e1512 LP |
2240 | if (dns_type_is_pseudo(rr->key->type)) |
2241 | return -EINVAL; | |
56352fe9 | 2242 | |
1c02e7ba | 2243 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2244 | if (r < 0) |
2245 | return r; | |
2246 | if (r > 0) | |
2247 | return false; | |
2248 | ||
105e1512 | 2249 | switch (rr->key->type) { |
56352fe9 | 2250 | |
105e1512 LP |
2251 | case DNS_TYPE_RRSIG: |
2252 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2253 | return false; | |
2254 | ||
2255 | case DNS_TYPE_SOA: | |
2256 | case DNS_TYPE_NS: { | |
2257 | DnsTransaction *dt; | |
2258 | Iterator i; | |
2259 | ||
b63fca62 | 2260 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2261 | |
2262 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2263 | ||
2264 | if (dt->key->class != rr->key->class) | |
2265 | continue; | |
2266 | if (dt->key->type != DNS_TYPE_DS) | |
2267 | continue; | |
2268 | ||
1c02e7ba | 2269 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2270 | if (r < 0) |
2271 | return r; | |
2272 | if (r == 0) | |
2273 | continue; | |
2274 | ||
2275 | /* We found a DS transactions for the SOA/NS | |
2276 | * RRs we are looking at. If it discovered signed DS | |
2277 | * RRs, then we need to be signed, too. */ | |
2278 | ||
097a2517 TA |
2279 | if (!dt->answer_authenticated) |
2280 | return false; | |
105e1512 | 2281 | |
097a2517 | 2282 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2283 | } |
2284 | ||
2285 | /* We found nothing that proves this is safe to leave | |
2286 | * this unauthenticated, hence ask inist on | |
2287 | * authentication. */ | |
2288 | return true; | |
2289 | } | |
2290 | ||
b63fca62 | 2291 | case DNS_TYPE_DS: |
105e1512 LP |
2292 | case DNS_TYPE_CNAME: |
2293 | case DNS_TYPE_DNAME: { | |
2294 | const char *parent = NULL; | |
2295 | DnsTransaction *dt; | |
2296 | Iterator i; | |
2297 | ||
b63fca62 LP |
2298 | /* |
2299 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2300 | * | |
2301 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2302 | */ | |
105e1512 LP |
2303 | |
2304 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2305 | ||
2306 | if (dt->key->class != rr->key->class) | |
2307 | continue; | |
2308 | if (dt->key->type != DNS_TYPE_SOA) | |
2309 | continue; | |
2310 | ||
2311 | if (!parent) { | |
1c02e7ba | 2312 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2313 | r = dns_name_parent(&parent); |
2314 | if (r < 0) | |
2315 | return r; | |
2316 | if (r == 0) { | |
b63fca62 LP |
2317 | if (rr->key->type == DNS_TYPE_DS) |
2318 | return true; | |
2319 | ||
105e1512 LP |
2320 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2321 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2322 | return -EBADMSG; | |
2323 | } | |
2324 | } | |
2325 | ||
1c02e7ba | 2326 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2327 | if (r < 0) |
2328 | return r; | |
2329 | if (r == 0) | |
2330 | continue; | |
2331 | ||
2332 | return t->answer_authenticated; | |
2333 | } | |
2334 | ||
2335 | return true; | |
2336 | } | |
2337 | ||
2338 | default: { | |
2339 | DnsTransaction *dt; | |
2340 | Iterator i; | |
2341 | ||
b63fca62 | 2342 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2343 | |
2344 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2345 | ||
2346 | if (dt->key->class != rr->key->class) | |
2347 | continue; | |
2348 | if (dt->key->type != DNS_TYPE_SOA) | |
2349 | continue; | |
2350 | ||
1c02e7ba | 2351 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2352 | if (r < 0) |
2353 | return r; | |
2354 | if (r == 0) | |
2355 | continue; | |
2356 | ||
2357 | /* We found the transaction that was supposed to find | |
2358 | * the SOA RR for us. It was successful, but found no | |
2359 | * RR for us. This means we are not at a zone cut. In | |
2360 | * this case, we require authentication if the SOA | |
2361 | * lookup was authenticated too. */ | |
2362 | return t->answer_authenticated; | |
2363 | } | |
2364 | ||
2365 | return true; | |
2366 | }} | |
56352fe9 LP |
2367 | } |
2368 | ||
d33b6cf3 LP |
2369 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2370 | DnsTransaction *dt; | |
2371 | const char *tld; | |
2372 | Iterator i; | |
2373 | int r; | |
2374 | ||
2375 | /* If DNSSEC downgrade mode is on, checks whether the | |
2376 | * specified RR is one level below a TLD we have proven not to | |
2377 | * exist. In such a case we assume that this is a private | |
2378 | * domain, and permit it. | |
2379 | * | |
2380 | * This detects cases like the Fritz!Box router networks. Each | |
2381 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2382 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2383 | * are served by the router itself, while requests for the | |
2384 | * "box" domain will result in NXDOMAIN. | |
2385 | * | |
2386 | * Note that this logic is unable to detect cases where a | |
2387 | * router serves a private DNS zone directly under | |
2388 | * non-existing TLD. In such a case we cannot detect whether | |
2389 | * the TLD is supposed to exist or not, as all requests we | |
2390 | * make for it will be answered by the router's zone, and not | |
2391 | * by the root zone. */ | |
2392 | ||
2393 | assert(t); | |
2394 | ||
2395 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2396 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2397 | ||
1c02e7ba | 2398 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2399 | r = dns_name_parent(&tld); |
2400 | if (r < 0) | |
2401 | return r; | |
2402 | if (r == 0) | |
2403 | return false; /* Already the root domain */ | |
2404 | ||
2405 | if (!dns_name_is_single_label(tld)) | |
2406 | return false; | |
2407 | ||
2408 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2409 | ||
2410 | if (dt->key->class != key->class) | |
2411 | continue; | |
2412 | ||
1c02e7ba | 2413 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2414 | if (r < 0) |
2415 | return r; | |
2416 | if (r == 0) | |
2417 | continue; | |
2418 | ||
2419 | /* We found an auxiliary lookup we did for the TLD. If | |
2420 | * that returned with NXDOMAIN, we know the TLD didn't | |
2421 | * exist, and hence this might be a private zone. */ | |
2422 | ||
2423 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2424 | } | |
2425 | ||
2426 | return false; | |
2427 | } | |
2428 | ||
105e1512 | 2429 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2430 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2431 | DnsTransaction *dt; |
2432 | const char *name; | |
4bbc06cc | 2433 | uint16_t type = 0; |
105e1512 LP |
2434 | Iterator i; |
2435 | int r; | |
56352fe9 LP |
2436 | |
2437 | assert(t); | |
2438 | ||
105e1512 LP |
2439 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2440 | * this negative reply */ | |
56352fe9 | 2441 | |
b652d4a2 | 2442 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2443 | return false; |
56352fe9 | 2444 | |
105e1512 LP |
2445 | if (dns_type_is_pseudo(t->key->type)) |
2446 | return -EINVAL; | |
2447 | ||
1c02e7ba | 2448 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2449 | if (r < 0) |
2450 | return r; | |
2451 | if (r > 0) | |
2452 | return false; | |
2453 | ||
d33b6cf3 LP |
2454 | r = dns_transaction_in_private_tld(t, t->key); |
2455 | if (r < 0) | |
2456 | return r; | |
2457 | if (r > 0) { | |
2458 | /* The lookup is from a TLD that is proven not to | |
2459 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2460 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2461 | |
202b76ae ZJS |
2462 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2463 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2464 | return false; |
2465 | } | |
2466 | ||
1c02e7ba | 2467 | name = dns_resource_key_name(t->key); |
105e1512 | 2468 | |
4bbc06cc | 2469 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2470 | |
4bbc06cc LP |
2471 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2472 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2473 | |
2474 | r = dns_name_parent(&name); | |
56352fe9 LP |
2475 | if (r < 0) |
2476 | return r; | |
2477 | if (r == 0) | |
105e1512 | 2478 | return true; |
4bbc06cc LP |
2479 | |
2480 | type = DNS_TYPE_SOA; | |
2481 | ||
2482 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2483 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2484 | type = DNS_TYPE_DS; | |
2485 | else | |
2486 | /* For all other negative replies, check for the SOA lookup */ | |
2487 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2488 | |
2489 | /* For all other RRs we check the SOA on the same level to see | |
2490 | * if it's signed. */ | |
2491 | ||
2492 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2493 | ||
2494 | if (dt->key->class != t->key->class) | |
2495 | continue; | |
4bbc06cc | 2496 | if (dt->key->type != type) |
56352fe9 LP |
2497 | continue; |
2498 | ||
1c02e7ba | 2499 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2500 | if (r < 0) |
2501 | return r; | |
105e1512 LP |
2502 | if (r == 0) |
2503 | continue; | |
2504 | ||
2505 | return dt->answer_authenticated; | |
56352fe9 LP |
2506 | } |
2507 | ||
105e1512 LP |
2508 | /* If in doubt, require NSEC/NSEC3 */ |
2509 | return true; | |
56352fe9 LP |
2510 | } |
2511 | ||
94aa7071 LP |
2512 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2513 | DnsResourceRecord *rrsig; | |
2514 | bool found = false; | |
2515 | int r; | |
2516 | ||
2517 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2518 | * the specified RRset is authenticated (i.e. has a matching | |
2519 | * DS RR). */ | |
2520 | ||
1c02e7ba | 2521 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2522 | if (r < 0) |
2523 | return r; | |
2524 | if (r > 0) | |
2525 | return false; | |
2526 | ||
94aa7071 LP |
2527 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2528 | DnsTransaction *dt; | |
2529 | Iterator i; | |
2530 | ||
2531 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2532 | if (r < 0) | |
2533 | return r; | |
2534 | if (r == 0) | |
2535 | continue; | |
2536 | ||
2537 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2538 | ||
2539 | if (dt->key->class != rr->key->class) | |
2540 | continue; | |
2541 | ||
2542 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2543 | ||
1c02e7ba | 2544 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2545 | if (r < 0) |
2546 | return r; | |
2547 | if (r == 0) | |
2548 | continue; | |
2549 | ||
2550 | /* OK, we found an auxiliary DNSKEY | |
2551 | * lookup. If that lookup is | |
2552 | * authenticated, report this. */ | |
2553 | ||
2554 | if (dt->answer_authenticated) | |
2555 | return true; | |
2556 | ||
2557 | found = true; | |
2558 | ||
2559 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2560 | ||
1c02e7ba | 2561 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2562 | if (r < 0) |
2563 | return r; | |
2564 | if (r == 0) | |
2565 | continue; | |
2566 | ||
2567 | /* OK, we found an auxiliary DS | |
2568 | * lookup. If that lookup is | |
2569 | * authenticated and non-zero, we | |
2570 | * won! */ | |
2571 | ||
2572 | if (!dt->answer_authenticated) | |
2573 | return false; | |
2574 | ||
2575 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2576 | } | |
2577 | } | |
2578 | } | |
2579 | ||
2580 | return found ? false : -ENXIO; | |
2581 | } | |
2582 | ||
b652d4a2 LP |
2583 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2584 | assert(t); | |
2585 | assert(rr); | |
2586 | ||
2587 | /* We know that the root domain is signed, hence if it appears | |
2588 | * not to be signed, there's a problem with the DNS server */ | |
2589 | ||
2590 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2591 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2592 | } |
2593 | ||
0f87f3e8 LP |
2594 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2595 | DnsResourceRecord *rr; | |
2596 | int r; | |
2597 | ||
2598 | assert(t); | |
2599 | ||
2600 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2601 | * for a key from our trust anchor. Note that we don't care | |
2602 | * whether the DNSKEY can be authenticated or not. It's | |
2603 | * sufficient if it is self-signed. */ | |
2604 | ||
2605 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2606 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2607 | if (r < 0) |
2608 | return r; | |
2609 | } | |
2610 | ||
2611 | return 0; | |
2612 | } | |
2613 | ||
c9c72065 LP |
2614 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2615 | bool changed; | |
2616 | int r; | |
2617 | ||
2618 | assert(t); | |
2619 | ||
2620 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2621 | * our trust anchors database considers revoked. */ | |
2622 | ||
2623 | do { | |
2624 | DnsResourceRecord *rr; | |
2625 | ||
2626 | changed = false; | |
2627 | ||
2628 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2629 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2630 | if (r < 0) | |
2631 | return r; | |
2632 | if (r > 0) { | |
2633 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2634 | if (r < 0) | |
2635 | return r; | |
2636 | ||
2637 | assert(r > 0); | |
2638 | changed = true; | |
2639 | break; | |
2640 | } | |
2641 | } | |
2642 | } while (changed); | |
2643 | ||
2644 | return 0; | |
2645 | } | |
2646 | ||
942eb2e7 LP |
2647 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2648 | DnsTransaction *dt; | |
2649 | Iterator i; | |
2650 | int r; | |
2651 | ||
2652 | assert(t); | |
2653 | ||
2654 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2655 | ||
2656 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2657 | ||
2658 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2659 | continue; | |
2660 | ||
2661 | if (!dt->answer_authenticated) | |
2662 | continue; | |
2663 | ||
2664 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2665 | if (r < 0) | |
2666 | return r; | |
2667 | } | |
2668 | ||
2669 | return 0; | |
2670 | } | |
2671 | ||
c690b20a ZJS |
2672 | typedef enum { |
2673 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2674 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2675 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2676 | } Phase; | |
2677 | ||
2678 | static int dnssec_validate_records( | |
2679 | DnsTransaction *t, | |
2680 | Phase phase, | |
2681 | bool *have_nsec, | |
2682 | DnsAnswer **validated) { | |
2683 | ||
547973de | 2684 | DnsResourceRecord *rr; |
56352fe9 | 2685 | int r; |
547973de | 2686 | |
c690b20a | 2687 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2688 | |
c690b20a ZJS |
2689 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2690 | DnsResourceRecord *rrsig = NULL; | |
2691 | DnssecResult result; | |
547973de | 2692 | |
c690b20a ZJS |
2693 | switch (rr->key->type) { |
2694 | case DNS_TYPE_RRSIG: | |
2695 | continue; | |
547973de | 2696 | |
c690b20a ZJS |
2697 | case DNS_TYPE_DNSKEY: |
2698 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2699 | if (phase == DNSSEC_PHASE_NSEC) | |
2700 | continue; | |
2701 | break; | |
547973de | 2702 | |
c690b20a ZJS |
2703 | case DNS_TYPE_NSEC: |
2704 | case DNS_TYPE_NSEC3: | |
2705 | *have_nsec = true; | |
547973de | 2706 | |
c690b20a ZJS |
2707 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2708 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2709 | continue; | |
2710 | break; | |
105e1512 | 2711 | |
c690b20a ZJS |
2712 | default: |
2713 | /* We validate all other RRs only in the ALL phases */ | |
2714 | if (phase != DNSSEC_PHASE_ALL) | |
2715 | continue; | |
2716 | } | |
b652d4a2 | 2717 | |
c690b20a ZJS |
2718 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2719 | if (r < 0) | |
2720 | return r; | |
547973de | 2721 | |
c690b20a | 2722 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2723 | |
c690b20a | 2724 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2725 | |
c690b20a ZJS |
2726 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2727 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2728 | * the set of validated keys for this transaction. */ | |
547973de | 2729 | |
c690b20a ZJS |
2730 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2731 | if (r < 0) | |
2732 | return r; | |
c9c72065 | 2733 | |
c690b20a ZJS |
2734 | /* Some of the DNSKEYs we just added might already have been revoked, |
2735 | * remove them again in that case. */ | |
2736 | r = dns_transaction_invalidate_revoked_keys(t); | |
2737 | if (r < 0) | |
2738 | return r; | |
2739 | } | |
547973de | 2740 | |
c690b20a ZJS |
2741 | /* Add the validated RRset to the new list of validated |
2742 | * RRsets, and remove it from the unvalidated RRsets. | |
2743 | * We mark the RRset as authenticated and cacheable. */ | |
2744 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2745 | if (r < 0) | |
2746 | return r; | |
547973de | 2747 | |
c690b20a | 2748 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2749 | |
c690b20a ZJS |
2750 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2751 | return 1; | |
2752 | } | |
547973de | 2753 | |
c690b20a ZJS |
2754 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2755 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2756 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2757 | if (phase != DNSSEC_PHASE_ALL) | |
2758 | continue; | |
0c7bff0a | 2759 | |
c690b20a ZJS |
2760 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2761 | bool authenticated = false; | |
2762 | const char *source; | |
0c7bff0a | 2763 | |
c690b20a | 2764 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 2765 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 2766 | |
c690b20a ZJS |
2767 | /* First step, determine the source of synthesis */ |
2768 | r = dns_resource_record_source(rrsig, &source); | |
2769 | if (r < 0) | |
2770 | return r; | |
0c7bff0a | 2771 | |
c690b20a | 2772 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2773 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2774 | source, |
2775 | rrsig->rrsig.signer, | |
2776 | &authenticated); | |
0c7bff0a | 2777 | |
c690b20a ZJS |
2778 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2779 | if (r == 0) | |
2780 | result = DNSSEC_INVALID; | |
2781 | else { | |
2782 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2783 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2784 | if (r < 0) | |
2785 | return r; | |
2786 | ||
2787 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2788 | ||
2789 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2790 | return 1; | |
0c7bff0a | 2791 | } |
c690b20a | 2792 | } |
0c7bff0a | 2793 | |
c690b20a ZJS |
2794 | if (result == DNSSEC_NO_SIGNATURE) { |
2795 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2796 | if (r < 0) |
2797 | return r; | |
c690b20a ZJS |
2798 | if (r == 0) { |
2799 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 2800 | * but remember that this is by no means authenticated. */ |
c690b20a ZJS |
2801 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
2802 | if (r < 0) | |
2803 | return r; | |
2804 | ||
2805 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2806 | return 1; | |
2807 | } | |
547973de | 2808 | |
c690b20a ZJS |
2809 | r = dns_transaction_known_signed(t, rr); |
2810 | if (r < 0) | |
2811 | return r; | |
2812 | if (r > 0) { | |
2813 | /* This is an RR we know has to be signed. If it isn't this means | |
2814 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2815 | |
c690b20a | 2816 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2817 | |
c690b20a | 2818 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2819 | |
c690b20a | 2820 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2821 | |
c690b20a | 2822 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2823 | if (r < 0) |
2824 | return r; | |
547973de | 2825 | |
c690b20a ZJS |
2826 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2827 | return 1; | |
2828 | } | |
a150ff5e | 2829 | |
c690b20a ZJS |
2830 | /* Otherwise, fail */ |
2831 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2832 | return 0; | |
f3cf586d | 2833 | } |
547973de | 2834 | |
c690b20a ZJS |
2835 | r = dns_transaction_in_private_tld(t, rr->key); |
2836 | if (r < 0) | |
2837 | return r; | |
2838 | if (r > 0) { | |
202b76ae | 2839 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2840 | |
c690b20a ZJS |
2841 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2842 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2843 | |
202b76ae ZJS |
2844 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2845 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2846 | |
c690b20a | 2847 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2848 | if (r < 0) |
2849 | return r; | |
0c7bff0a | 2850 | |
c690b20a ZJS |
2851 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2852 | return 1; | |
2853 | } | |
2854 | } | |
0c7bff0a | 2855 | |
c690b20a ZJS |
2856 | if (IN_SET(result, |
2857 | DNSSEC_MISSING_KEY, | |
2858 | DNSSEC_SIGNATURE_EXPIRED, | |
2859 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2860 | |
c690b20a ZJS |
2861 | r = dns_transaction_dnskey_authenticated(t, rr); |
2862 | if (r < 0 && r != -ENXIO) | |
2863 | return r; | |
2864 | if (r == 0) { | |
2865 | /* The DNSKEY transaction was not authenticated, this means there's | |
2866 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2867 | |
c690b20a | 2868 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2869 | if (r < 0) |
2870 | return r; | |
b652d4a2 | 2871 | |
c690b20a ZJS |
2872 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2873 | return 1; | |
2874 | } | |
2875 | } | |
b652d4a2 | 2876 | |
c690b20a ZJS |
2877 | r = dns_transaction_is_primary_response(t, rr); |
2878 | if (r < 0) | |
2879 | return r; | |
2880 | if (r > 0) { | |
2881 | /* Look for a matching DNAME for this CNAME */ | |
2882 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2883 | if (r < 0) | |
2884 | return r; | |
2885 | if (r == 0) { | |
2886 | /* Also look among the stuff we already validated */ | |
2887 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2888 | if (r < 0) |
2889 | return r; | |
c690b20a | 2890 | } |
d33b6cf3 | 2891 | |
c690b20a ZJS |
2892 | if (r == 0) { |
2893 | if (IN_SET(result, | |
2894 | DNSSEC_INVALID, | |
2895 | DNSSEC_SIGNATURE_EXPIRED, | |
2896 | DNSSEC_NO_SIGNATURE)) | |
2897 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
2898 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2899 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
2900 | ||
2901 | /* This is a primary response to our question, and it failed validation. | |
2902 | * That's fatal. */ | |
2903 | t->answer_dnssec_result = result; | |
2904 | return 0; | |
2905 | } | |
d33b6cf3 | 2906 | |
c690b20a ZJS |
2907 | /* This is a primary response, but we do have a DNAME RR |
2908 | * in the RR that can replay this CNAME, hence rely on | |
2909 | * that, and we can remove the CNAME in favour of it. */ | |
2910 | } | |
d33b6cf3 | 2911 | |
c690b20a ZJS |
2912 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
2913 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2914 | if (r < 0) | |
2915 | return r; | |
d33b6cf3 | 2916 | |
c690b20a ZJS |
2917 | /* We dropped something from the answer, start from the beginning. */ |
2918 | return 1; | |
2919 | } | |
f3cf586d | 2920 | |
c690b20a ZJS |
2921 | return 2; /* Finito. */ |
2922 | } | |
94aa7071 | 2923 | |
c690b20a ZJS |
2924 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2925 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
2926 | Phase phase; | |
2927 | DnsAnswerFlags flags; | |
2928 | int r; | |
202b76ae | 2929 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 2930 | |
c690b20a | 2931 | assert(t); |
94aa7071 | 2932 | |
c690b20a ZJS |
2933 | /* We have now collected all DS and DNSKEY RRs in |
2934 | * t->validated_keys, let's see which RRs we can now | |
2935 | * authenticate with that. */ | |
94aa7071 | 2936 | |
c690b20a ZJS |
2937 | if (t->scope->dnssec_mode == DNSSEC_NO) |
2938 | return 0; | |
a150ff5e | 2939 | |
c690b20a ZJS |
2940 | /* Already validated */ |
2941 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
2942 | return 0; | |
105e1512 | 2943 | |
c690b20a ZJS |
2944 | /* Our own stuff needs no validation */ |
2945 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
2946 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
2947 | t->answer_authenticated = true; | |
2948 | return 0; | |
2949 | } | |
a150ff5e | 2950 | |
c690b20a ZJS |
2951 | /* Cached stuff is not affected by validation. */ |
2952 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2953 | return 0; | |
f3cf586d | 2954 | |
c690b20a ZJS |
2955 | if (!dns_transaction_dnssec_supported_full(t)) { |
2956 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2957 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 2958 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
2959 | return 0; |
2960 | } | |
f3cf586d | 2961 | |
202b76ae ZJS |
2962 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
2963 | t->id, | |
2964 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 2965 | |
c690b20a ZJS |
2966 | /* First, see if this response contains any revoked trust |
2967 | * anchors we care about */ | |
2968 | r = dns_transaction_check_revoked_trust_anchors(t); | |
2969 | if (r < 0) | |
2970 | return r; | |
43e6779a | 2971 | |
c690b20a ZJS |
2972 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
2973 | r = dns_transaction_copy_validated(t); | |
2974 | if (r < 0) | |
2975 | return r; | |
43e6779a | 2976 | |
c690b20a ZJS |
2977 | /* Second, see if there are DNSKEYs we already know a |
2978 | * validated DS for. */ | |
2979 | r = dns_transaction_validate_dnskey_by_ds(t); | |
2980 | if (r < 0) | |
2981 | return r; | |
43e6779a | 2982 | |
c690b20a ZJS |
2983 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
2984 | * anchor says are revoked. After all we might have marked | |
2985 | * some keys revoked above, but they might still be lingering | |
2986 | * in our validated_keys list. */ | |
2987 | r = dns_transaction_invalidate_revoked_keys(t); | |
2988 | if (r < 0) | |
2989 | return r; | |
f3cf586d | 2990 | |
c690b20a ZJS |
2991 | phase = DNSSEC_PHASE_DNSKEY; |
2992 | for (;;) { | |
2993 | bool have_nsec = false; | |
f3cf586d | 2994 | |
c690b20a ZJS |
2995 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
2996 | if (r <= 0) | |
2997 | return r; | |
547973de | 2998 | |
c690b20a ZJS |
2999 | /* Try again as long as we managed to achieve something */ |
3000 | if (r == 1) | |
547973de LP |
3001 | continue; |
3002 | ||
c690b20a | 3003 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3004 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3005 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3006 | continue; |
3007 | } | |
3008 | ||
c690b20a ZJS |
3009 | if (phase != DNSSEC_PHASE_ALL) { |
3010 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3011 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3012 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3013 | continue; |
547973de LP |
3014 | } |
3015 | ||
56352fe9 | 3016 | /* We're done */ |
547973de LP |
3017 | break; |
3018 | } | |
3019 | ||
3020 | dns_answer_unref(t->answer); | |
3021 | t->answer = validated; | |
3022 | validated = NULL; | |
3023 | ||
72667f08 LP |
3024 | /* At this point the answer only contains validated |
3025 | * RRsets. Now, let's see if it actually answers the question | |
3026 | * we asked. If so, great! If it doesn't, then see if | |
3027 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3028 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3029 | if (r > 0) { |
105e1512 LP |
3030 | /* Yes, it answers the question! */ |
3031 | ||
3032 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3033 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3034 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3035 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3036 | t->answer_authenticated = true; | |
3037 | } else { | |
3038 | /* The answer is not fully authenticated. */ | |
019036a4 | 3039 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3040 | t->answer_authenticated = false; |
3041 | } | |
3042 | ||
72667f08 LP |
3043 | } else if (r == 0) { |
3044 | DnssecNsecResult nr; | |
ed29bfdc | 3045 | bool authenticated = false; |
72667f08 LP |
3046 | |
3047 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3048 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3049 | if (r < 0) |
3050 | return r; | |
3051 | ||
3052 | switch (nr) { | |
3053 | ||
3054 | case DNSSEC_NSEC_NXDOMAIN: | |
3055 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3056 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3057 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3058 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3059 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3060 | |
59c5b597 | 3061 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3062 | break; |
3063 | ||
3064 | case DNSSEC_NSEC_NODATA: | |
3065 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3066 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3067 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3068 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3069 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3070 | |
59c5b597 | 3071 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3072 | break; |
3073 | ||
105e1512 LP |
3074 | case DNSSEC_NSEC_OPTOUT: |
3075 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3076 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3077 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3078 | t->answer_authenticated = false; |
7aa8ce98 | 3079 | |
59c5b597 | 3080 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3081 | break; |
3082 | ||
72667f08 LP |
3083 | case DNSSEC_NSEC_NO_RR: |
3084 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3085 | |
3086 | r = dns_transaction_requires_nsec(t); | |
3087 | if (r < 0) | |
3088 | return r; | |
7aa8ce98 | 3089 | if (r > 0) { |
019036a4 | 3090 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3091 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3092 | } else { |
019036a4 | 3093 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3094 | t->answer_authenticated = false; |
59c5b597 | 3095 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3096 | } |
3097 | ||
3098 | break; | |
3099 | ||
3100 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3101 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3102 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3103 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3104 | break; |
3105 | ||
3106 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3107 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3108 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3109 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3110 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3111 | break; |
3112 | ||
3113 | default: | |
3114 | assert_not_reached("Unexpected NSEC result."); | |
3115 | } | |
3116 | } | |
3117 | ||
547973de LP |
3118 | return 1; |
3119 | } | |
3120 | ||
ec2c5e43 LP |
3121 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3122 | [DNS_TRANSACTION_NULL] = "null", | |
3123 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3124 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3125 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3126 | [DNS_TRANSACTION_SUCCESS] = "success", |
3127 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3128 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3129 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3130 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3131 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3132 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3133 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3134 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3135 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3136 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3137 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3138 | }; |
3139 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3140 | |
3141 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3142 | [DNS_TRANSACTION_NETWORK] = "network", | |
3143 | [DNS_TRANSACTION_CACHE] = "cache", | |
3144 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3145 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3146 | }; |
3147 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |