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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
ec2c5e43 | 2 | |
62cc1c55 | 3 | #include "sd-messages.h" |
beef6a5f | 4 | |
ec2c5e43 | 5 | #include "af-list.h" |
b5efdb8a | 6 | #include "alloc-util.h" |
f52e61da | 7 | #include "dns-domain.h" |
7cc6ed7b | 8 | #include "errno-list.h" |
c3fecddf | 9 | #include "errno-util.h" |
3ffd4af2 LP |
10 | #include "fd-util.h" |
11 | #include "random-util.h" | |
7778dfff | 12 | #include "resolved-dns-cache.h" |
3ffd4af2 | 13 | #include "resolved-dns-transaction.h" |
6016fcb0 | 14 | #include "resolved-dnstls.h" |
aedf00a2 | 15 | #include "resolved-llmnr.h" |
6016fcb0 | 16 | #include "string-table.h" |
5d67a7ae | 17 | |
b214dc0f | 18 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 19 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 20 | |
dbc4661a MCO |
21 | /* After how much time to repeat classic DNS requests */ |
22 | #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX) | |
23 | ||
c61d2b44 LP |
24 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
25 | assert(t); | |
26 | ||
27 | t->received = dns_packet_unref(t->received); | |
28 | t->answer = dns_answer_unref(t->answer); | |
29 | t->answer_rcode = 0; | |
30 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
31 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
32 | t->answer_authenticated = false; | |
d3760be0 | 33 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 34 | t->answer_errno = 0; |
c61d2b44 LP |
35 | } |
36 | ||
c5b4f861 LP |
37 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
38 | DnsTransaction *z; | |
39 | ||
40 | assert(t); | |
41 | ||
42 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
43 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 44 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
45 | dns_transaction_gc(z); |
46 | } | |
47 | } | |
48 | ||
f32f0e57 LP |
49 | static void dns_transaction_close_connection(DnsTransaction *t) { |
50 | assert(t); | |
51 | ||
b30bf55d LP |
52 | if (t->stream) { |
53 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
98767d75 IT |
54 | LIST_REMOVE(transactions_by_stream, t->stream->transactions, t); |
55 | ||
56 | /* Remove packet in case it's still in the queue */ | |
57 | dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent)); | |
58 | ||
b30bf55d LP |
59 | t->stream = dns_stream_unref(t->stream); |
60 | } | |
61 | ||
f32f0e57 LP |
62 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
63 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
64 | } | |
65 | ||
f535705a | 66 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
67 | assert(t); |
68 | ||
69 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
70 | } |
71 | ||
ec2c5e43 | 72 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 73 | DnsQueryCandidate *c; |
ec2c5e43 | 74 | DnsZoneItem *i; |
547973de | 75 | DnsTransaction *z; |
ec2c5e43 LP |
76 | |
77 | if (!t) | |
78 | return NULL; | |
79 | ||
51e399bc LP |
80 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
81 | ||
f32f0e57 | 82 | dns_transaction_close_connection(t); |
f535705a | 83 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 84 | |
ec2c5e43 | 85 | dns_packet_unref(t->sent); |
c61d2b44 | 86 | dns_transaction_reset_answer(t); |
ec2c5e43 | 87 | |
8300ba21 | 88 | dns_server_unref(t->server); |
ec2c5e43 LP |
89 | |
90 | if (t->scope) { | |
f9ebb22a LP |
91 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
92 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
93 | |
94 | if (t->id != 0) | |
95 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
96 | } | |
97 | ||
547973de | 98 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 99 | set_remove(c->transactions, t); |
547973de | 100 | set_free(t->notify_query_candidates); |
801ad6a6 | 101 | |
35aa04e9 LP |
102 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
103 | set_remove(c->transactions, t); | |
104 | set_free(t->notify_query_candidates_done); | |
105 | ||
547973de | 106 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 107 | i->probe_transaction = NULL; |
547973de LP |
108 | set_free(t->notify_zone_items); |
109 | ||
35aa04e9 LP |
110 | while ((i = set_steal_first(t->notify_zone_items_done))) |
111 | i->probe_transaction = NULL; | |
112 | set_free(t->notify_zone_items_done); | |
113 | ||
547973de LP |
114 | while ((z = set_steal_first(t->notify_transactions))) |
115 | set_remove(z->dnssec_transactions, t); | |
116 | set_free(t->notify_transactions); | |
117 | ||
35aa04e9 LP |
118 | while ((z = set_steal_first(t->notify_transactions_done))) |
119 | set_remove(z->dnssec_transactions, t); | |
120 | set_free(t->notify_transactions_done); | |
121 | ||
c5b4f861 | 122 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
123 | set_free(t->dnssec_transactions); |
124 | ||
125 | dns_answer_unref(t->validated_keys); | |
97cc656c | 126 | dns_resource_key_unref(t->key); |
97cc656c | 127 | |
6b430fdb | 128 | return mfree(t); |
ec2c5e43 LP |
129 | } |
130 | ||
131 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
132 | ||
51e399bc | 133 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
134 | assert(t); |
135 | ||
136 | if (t->block_gc > 0) | |
51e399bc | 137 | return true; |
ec2c5e43 | 138 | |
547973de | 139 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 140 | set_isempty(t->notify_query_candidates_done) && |
547973de | 141 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
142 | set_isempty(t->notify_zone_items_done) && |
143 | set_isempty(t->notify_transactions) && | |
144 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 145 | dns_transaction_free(t); |
51e399bc LP |
146 | return false; |
147 | } | |
148 | ||
149 | return true; | |
ec2c5e43 LP |
150 | } |
151 | ||
4dd15077 LP |
152 | static uint16_t pick_new_id(Manager *m) { |
153 | uint16_t new_id; | |
154 | ||
4ea8b443 ZJS |
155 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the |
156 | * number of transactions, and it's much lower than the space of IDs. */ | |
4dd15077 LP |
157 | |
158 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
159 | ||
160 | do | |
161 | random_bytes(&new_id, sizeof(new_id)); | |
162 | while (new_id == 0 || | |
163 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
164 | ||
165 | return new_id; | |
166 | } | |
167 | ||
f52e61da | 168 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
169 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
170 | int r; | |
171 | ||
172 | assert(ret); | |
173 | assert(s); | |
f52e61da | 174 | assert(key); |
ec2c5e43 | 175 | |
9eae2bf3 | 176 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 177 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 178 | return -EINVAL; |
d0129ddb LP |
179 | if (dns_type_is_obsolete(key->type)) |
180 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
181 | |
182 | /* We only support the IN class */ | |
4c701096 | 183 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
184 | return -EOPNOTSUPP; |
185 | ||
b214dc0f LP |
186 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
187 | return -EBUSY; | |
188 | ||
d5099efc | 189 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
190 | if (r < 0) |
191 | return r; | |
192 | ||
f9ebb22a | 193 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
194 | if (r < 0) |
195 | return r; | |
196 | ||
1ed31408 | 197 | t = new(DnsTransaction, 1); |
ec2c5e43 LP |
198 | if (!t) |
199 | return -ENOMEM; | |
200 | ||
1ed31408 LP |
201 | *t = (DnsTransaction) { |
202 | .dns_udp_fd = -1, | |
203 | .answer_source = _DNS_TRANSACTION_SOURCE_INVALID, | |
204 | .answer_dnssec_result = _DNSSEC_RESULT_INVALID, | |
205 | .answer_nsec_ttl = (uint32_t) -1, | |
206 | .key = dns_resource_key_ref(key), | |
207 | .current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID, | |
208 | .clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID, | |
209 | .id = pick_new_id(s->manager), | |
210 | }; | |
ec2c5e43 LP |
211 | |
212 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
213 | if (r < 0) { | |
214 | t->id = 0; | |
215 | return r; | |
216 | } | |
217 | ||
f9ebb22a | 218 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
219 | if (r < 0) { |
220 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
221 | return r; | |
222 | } | |
223 | ||
f9ebb22a | 224 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
225 | t->scope = s; |
226 | ||
313cefa1 | 227 | s->manager->n_transactions_total++; |
a150ff5e | 228 | |
ec2c5e43 LP |
229 | if (ret) |
230 | *ret = t; | |
231 | ||
232 | t = NULL; | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
4dd15077 LP |
237 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
238 | uint16_t new_id; | |
239 | assert(t); | |
240 | ||
241 | /* Pick a new ID for this transaction. */ | |
242 | ||
243 | new_id = pick_new_id(t->scope->manager); | |
244 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
245 | ||
246 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
247 | t->id = new_id; | |
248 | ||
249 | /* Make sure we generate a new packet with the new ID */ | |
250 | t->sent = dns_packet_unref(t->sent); | |
251 | } | |
252 | ||
ec2c5e43 | 253 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 254 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 255 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 256 | DnsZoneItem *z; |
ec2c5e43 LP |
257 | |
258 | assert(t); | |
259 | assert(p); | |
260 | ||
261 | if (manager_our_packet(t->scope->manager, p) != 0) | |
262 | return; | |
263 | ||
164d025d | 264 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 265 | |
a5784c49 LP |
266 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
267 | t->id, | |
42df9532 | 268 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
ec2c5e43 | 269 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 270 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 271 | af_to_name_short(t->scope->family), |
164d025d | 272 | strnull(pretty)); |
ec2c5e43 | 273 | |
a4076574 LP |
274 | /* RFC 4795, Section 4.1 says that the peer with the |
275 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
276 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
277 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
278 | return; |
279 | } | |
280 | ||
4d91eec4 | 281 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 282 | |
ec2c5e43 | 283 | t->block_gc++; |
35aa04e9 | 284 | |
547973de | 285 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
286 | /* First, make sure the zone item drops the reference |
287 | * to us */ | |
288 | dns_zone_item_probe_stop(z); | |
289 | ||
290 | /* Secondly, report this as conflict, so that we might | |
291 | * look for a different hostname */ | |
ec2c5e43 | 292 | dns_zone_item_conflict(z); |
3ef64445 | 293 | } |
ec2c5e43 LP |
294 | t->block_gc--; |
295 | ||
296 | dns_transaction_gc(t); | |
297 | } | |
298 | ||
299 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 300 | DnsQueryCandidate *c; |
ec2c5e43 | 301 | DnsZoneItem *z; |
547973de | 302 | DnsTransaction *d; |
7cc6ed7b | 303 | const char *st; |
202b76ae | 304 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
305 | |
306 | assert(t); | |
547973de | 307 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 308 | |
202b76ae | 309 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
42df9532 | 310 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str); |
202b76ae | 311 | |
f61dfddb | 312 | log_struct(LOG_NOTICE, |
2b044526 | 313 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
202b76ae | 314 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 315 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 316 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 317 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
8aa5afd2 | 318 | "DNS_SERVER=%s", strna(dns_server_string_full(t->server)), |
a1230ff9 | 319 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level)); |
202b76ae | 320 | } |
f61dfddb | 321 | |
ec2c5e43 LP |
322 | /* Note that this call might invalidate the query. Callers |
323 | * should hence not attempt to access the query or transaction | |
324 | * after calling this function. */ | |
325 | ||
7cc6ed7b LP |
326 | if (state == DNS_TRANSACTION_ERRNO) |
327 | st = errno_to_name(t->answer_errno); | |
328 | else | |
329 | st = dns_transaction_state_to_string(state); | |
330 | ||
a5784c49 LP |
331 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
332 | t->id, | |
42df9532 | 333 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
ec2c5e43 | 334 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 335 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 336 | af_to_name_short(t->scope->family), |
7cc6ed7b | 337 | st, |
a5784c49 LP |
338 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
339 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
340 | |
341 | t->state = state; | |
342 | ||
f32f0e57 | 343 | dns_transaction_close_connection(t); |
f535705a | 344 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
345 | |
346 | /* Notify all queries that are interested, but make sure the | |
347 | * transaction isn't freed while we are still looking at it */ | |
348 | t->block_gc++; | |
f7014757 | 349 | |
35aa04e9 | 350 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 351 | dns_query_candidate_notify(c); |
35aa04e9 | 352 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 353 | |
35aa04e9 LP |
354 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
355 | dns_zone_item_notify(z); | |
356 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
8d67e72c | 357 | if (t->probing && t->state == DNS_TRANSACTION_ATTEMPTS_MAX_REACHED) |
1a63fc54 | 358 | (void) dns_scope_announce(t->scope, false); |
f7014757 | 359 | |
35aa04e9 LP |
360 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
361 | dns_transaction_notify(d, t); | |
362 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
363 | |
364 | t->block_gc--; | |
ec2c5e43 LP |
365 | dns_transaction_gc(t); |
366 | } | |
367 | ||
fd8a3017 LP |
368 | static void dns_transaction_complete_errno(DnsTransaction *t, int error) { |
369 | assert(t); | |
370 | assert(error != 0); | |
371 | ||
372 | t->answer_errno = abs(error); | |
373 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
374 | } | |
375 | ||
519ef046 LP |
376 | static int dns_transaction_pick_server(DnsTransaction *t) { |
377 | DnsServer *server; | |
378 | ||
379 | assert(t); | |
380 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
381 | ||
d001e0a3 LP |
382 | /* Pick a DNS server and a feature level for it. */ |
383 | ||
519ef046 LP |
384 | server = dns_scope_get_dns_server(t->scope); |
385 | if (!server) | |
386 | return -ESRCH; | |
387 | ||
d001e0a3 LP |
388 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
389 | * different properties. */ | |
390 | if (server != t->server) | |
391 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
392 | ||
274b8748 | 393 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 394 | |
d001e0a3 LP |
395 | /* Clamp the feature level if that is requested. */ |
396 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
397 | t->current_feature_level > t->clamp_feature_level) | |
398 | t->current_feature_level = t->clamp_feature_level; | |
399 | ||
400 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
401 | ||
519ef046 LP |
402 | if (server == t->server) |
403 | return 0; | |
404 | ||
405 | dns_server_unref(t->server); | |
406 | t->server = dns_server_ref(server); | |
407 | ||
44db02d0 LP |
408 | t->n_picked_servers ++; |
409 | ||
8aa5afd2 | 410 | log_debug("Using DNS server %s for transaction %u.", strna(dns_server_string_full(t->server)), t->id); |
d001e0a3 | 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); | |
fd8a3017 LP |
427 | if (r < 0) |
428 | dns_transaction_complete_errno(t, r); | |
8d10d620 LP |
429 | } |
430 | ||
c02cf2f4 | 431 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
432 | int r; |
433 | ||
c02cf2f4 LP |
434 | assert(t); |
435 | ||
5278bbfe LP |
436 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
437 | ||
c02cf2f4 LP |
438 | if (!t->server) |
439 | return 0; | |
440 | ||
441 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
442 | return 0; | |
443 | ||
444 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
445 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
446 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
447 | OPT RR or DO bit. One of these cases is documented here, for example: | |
448 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
449 | ||
4dd15077 LP |
450 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
451 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
452 | |
453 | r = dns_transaction_go(t); | |
454 | if (r < 0) | |
455 | return r; | |
456 | ||
457 | return 1; | |
c02cf2f4 LP |
458 | } |
459 | ||
98767d75 IT |
460 | static void on_transaction_stream_error(DnsTransaction *t, int error) { |
461 | assert(t); | |
ec2c5e43 | 462 | |
b30bf55d | 463 | dns_transaction_close_connection(t); |
ec2c5e43 | 464 | |
a1a3f73a | 465 | if (ERRNO_IS_DISCONNECT(error)) { |
0791110f LP |
466 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
467 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
468 | * question on this scope. */ | |
469 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
daab72ea | 470 | return; |
0791110f LP |
471 | } |
472 | ||
d001e0a3 | 473 | dns_transaction_retry(t, true); |
daab72ea | 474 | return; |
ac720200 | 475 | } |
fd8a3017 LP |
476 | if (error != 0) |
477 | dns_transaction_complete_errno(t, error); | |
98767d75 IT |
478 | } |
479 | ||
480 | static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsPacket *p) { | |
481 | assert(t); | |
482 | assert(p); | |
483 | ||
484 | dns_transaction_close_connection(t); | |
ec2c5e43 | 485 | |
a4076574 | 486 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 487 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
488 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
489 | return 0; | |
490 | } | |
491 | ||
492 | dns_scope_check_conflicts(t->scope, p); | |
493 | ||
ec2c5e43 LP |
494 | t->block_gc++; |
495 | dns_transaction_process_reply(t, p); | |
496 | t->block_gc--; | |
497 | ||
519ef046 LP |
498 | /* If the response wasn't useful, then complete the transition |
499 | * now. After all, we are the worst feature set now with TCP | |
500 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
501 | if (t->state == DNS_TRANSACTION_PENDING) |
502 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
503 | else |
504 | dns_transaction_gc(t); | |
ec2c5e43 LP |
505 | |
506 | return 0; | |
507 | } | |
508 | ||
98767d75 | 509 | static int on_stream_complete(DnsStream *s, int error) { |
7172e4ee | 510 | assert(s); |
98767d75 IT |
511 | |
512 | if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) { | |
98767d75 IT |
513 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
514 | ||
515 | if (s->transactions) { | |
97d5d905 LP |
516 | DnsTransaction *t; |
517 | ||
98767d75 | 518 | t = s->transactions; |
3da3cdd5 | 519 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level); |
98767d75 IT |
520 | } |
521 | } | |
522 | ||
97d5d905 LP |
523 | if (error != 0) { |
524 | DnsTransaction *t, *n; | |
525 | ||
526 | LIST_FOREACH_SAFE(transactions_by_stream, t, n, s->transactions) | |
98767d75 | 527 | on_transaction_stream_error(t, error); |
97d5d905 | 528 | } |
98767d75 | 529 | |
97d5d905 | 530 | return 0; |
98767d75 IT |
531 | } |
532 | ||
747a8a74 | 533 | static int on_stream_packet(DnsStream *s) { |
98767d75 | 534 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
98767d75 IT |
535 | DnsTransaction *t; |
536 | ||
aa337a5e LP |
537 | assert(s); |
538 | ||
98767d75 | 539 | /* Take ownership of packet to be able to receive new packets */ |
aa337a5e LP |
540 | p = dns_stream_take_read_packet(s); |
541 | assert(p); | |
98767d75 IT |
542 | |
543 | t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); | |
aa337a5e LP |
544 | if (t) |
545 | return dns_transaction_on_stream_packet(t, p); | |
98767d75 | 546 | |
8227cfa1 | 547 | /* Ignore incorrect transaction id as an old transaction can have been canceled. */ |
30f9e0bf | 548 | log_debug("Received unexpected TCP reply packet with id %" PRIu16 ", ignoring.", DNS_PACKET_ID(p)); |
aa337a5e | 549 | return 0; |
98767d75 IT |
550 | } |
551 | ||
da9de738 YW |
552 | static uint16_t dns_transaction_port(DnsTransaction *t) { |
553 | if (t->server->port > 0) | |
554 | return t->server->port; | |
555 | return DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53; | |
ec962fba LP |
556 | } |
557 | ||
98767d75 | 558 | static int dns_transaction_emit_tcp(DnsTransaction *t) { |
98767d75 | 559 | _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; |
652ba568 | 560 | _cleanup_close_ int fd = -1; |
91ccab1e | 561 | union sockaddr_union sa; |
652ba568 | 562 | DnsStreamType type; |
ec2c5e43 LP |
563 | int r; |
564 | ||
565 | assert(t); | |
566 | ||
519ef046 | 567 | dns_transaction_close_connection(t); |
ec2c5e43 | 568 | |
106784eb | 569 | switch (t->scope->protocol) { |
519ef046 | 570 | |
106784eb | 571 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
572 | r = dns_transaction_pick_server(t); |
573 | if (r < 0) | |
574 | return r; | |
575 | ||
42df9532 | 576 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) |
91adc4db LP |
577 | return -EOPNOTSUPP; |
578 | ||
274b8748 | 579 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
580 | if (r < 0) |
581 | return r; | |
582 | ||
5d67a7ae | 583 | if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted)) |
98767d75 IT |
584 | s = dns_stream_ref(t->server->stream); |
585 | else | |
da9de738 | 586 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, dns_transaction_port(t), &sa); |
98767d75 | 587 | |
652ba568 | 588 | type = DNS_STREAM_LOOKUP; |
106784eb | 589 | break; |
ec2c5e43 | 590 | |
106784eb | 591 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 592 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 593 | if (t->received) |
91ccab1e | 594 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa); |
ec2c5e43 LP |
595 | else { |
596 | union in_addr_union address; | |
a7f7d1bd | 597 | int family = AF_UNSPEC; |
ec2c5e43 LP |
598 | |
599 | /* Otherwise, try to talk to the owner of a | |
600 | * the IP address, in case this is a reverse | |
601 | * PTR lookup */ | |
f52e61da | 602 | |
42df9532 | 603 | r = dns_name_address(dns_resource_key_name(dns_transaction_key(t)), &family, &address); |
ec2c5e43 LP |
604 | if (r < 0) |
605 | return r; | |
606 | if (r == 0) | |
607 | return -EINVAL; | |
9e08a6e0 | 608 | if (family != t->scope->family) |
9318cdd3 | 609 | return -ESRCH; |
ec2c5e43 | 610 | |
91ccab1e | 611 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa); |
ec2c5e43 | 612 | } |
106784eb | 613 | |
652ba568 | 614 | type = DNS_STREAM_LLMNR_SEND; |
106784eb DM |
615 | break; |
616 | ||
617 | default: | |
ec2c5e43 | 618 | return -EAFNOSUPPORT; |
106784eb | 619 | } |
ec2c5e43 | 620 | |
98767d75 IT |
621 | if (!s) { |
622 | if (fd < 0) | |
623 | return fd; | |
ec2c5e43 | 624 | |
652ba568 | 625 | r = dns_stream_new(t->scope->manager, &s, type, t->scope->protocol, fd, &sa); |
98767d75 IT |
626 | if (r < 0) |
627 | return r; | |
628 | ||
629 | fd = -1; | |
630 | ||
56ddbf10 | 631 | #if ENABLE_DNS_OVER_TLS |
199dda9c LP |
632 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
633 | DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) { | |
634 | ||
b02a7e1a | 635 | assert(t->server); |
6016fcb0 | 636 | r = dnstls_stream_connect_tls(s, t->server); |
5d67a7ae IT |
637 | if (r < 0) |
638 | return r; | |
639 | } | |
640 | #endif | |
641 | ||
19feb28f | 642 | if (t->server) { |
904dcaf9 | 643 | dns_server_unref_stream(t->server); |
19feb28f | 644 | s->server = dns_server_ref(t->server); |
8227cfa1 | 645 | t->server->stream = dns_stream_ref(s); |
19feb28f IT |
646 | } |
647 | ||
98767d75 | 648 | s->complete = on_stream_complete; |
747a8a74 | 649 | s->on_packet = on_stream_packet; |
98767d75 IT |
650 | |
651 | /* The interface index is difficult to determine if we are | |
652 | * connecting to the local host, hence fill this in right away | |
653 | * instead of determining it from the socket */ | |
654 | s->ifindex = dns_scope_ifindex(t->scope); | |
655 | } | |
656 | ||
657 | t->stream = TAKE_PTR(s); | |
658 | LIST_PREPEND(transactions_by_stream, t->stream->transactions, t); | |
ec2c5e43 LP |
659 | |
660 | r = dns_stream_write_packet(t->stream, t->sent); | |
661 | if (r < 0) { | |
98767d75 | 662 | dns_transaction_close_connection(t); |
ec2c5e43 LP |
663 | return r; |
664 | } | |
665 | ||
519ef046 LP |
666 | dns_transaction_reset_answer(t); |
667 | ||
cbe4216d LP |
668 | t->tried_stream = true; |
669 | ||
ec2c5e43 LP |
670 | return 0; |
671 | } | |
672 | ||
547973de | 673 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
674 | assert(t); |
675 | ||
676 | /* For mDNS we cache whenever we get the packet, rather than | |
677 | * in each transaction. */ | |
678 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
679 | return; | |
680 | ||
ceeddf79 | 681 | /* Caching disabled? */ |
37d7a7d9 | 682 | if (t->scope->manager->enable_cache == DNS_CACHE_MODE_NO) |
ceeddf79 MP |
683 | return; |
684 | ||
6d8325f6 PS |
685 | /* Packet from localhost? */ |
686 | if (!t->scope->manager->cache_from_localhost && | |
687 | in_addr_is_localhost(t->received->family, &t->received->sender) != 0) | |
547973de LP |
688 | return; |
689 | ||
547973de | 690 | dns_cache_put(&t->scope->cache, |
37d7a7d9 | 691 | t->scope->manager->enable_cache, |
42df9532 | 692 | dns_transaction_key(t), |
547973de LP |
693 | t->answer_rcode, |
694 | t->answer, | |
547973de | 695 | t->answer_authenticated, |
d3760be0 | 696 | t->answer_nsec_ttl, |
547973de LP |
697 | 0, |
698 | t->received->family, | |
699 | &t->received->sender); | |
700 | } | |
701 | ||
105e1512 LP |
702 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
703 | DnsTransaction *dt; | |
105e1512 LP |
704 | |
705 | assert(t); | |
706 | ||
90e74a66 | 707 | SET_FOREACH(dt, t->dnssec_transactions) |
105e1512 LP |
708 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) |
709 | return true; | |
710 | ||
711 | return false; | |
712 | } | |
713 | ||
942eb2e7 LP |
714 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
715 | DnsTransaction *dt; | |
942eb2e7 LP |
716 | |
717 | assert(t); | |
718 | ||
719 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
720 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
721 | ||
90e74a66 | 722 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
723 | |
724 | switch (dt->state) { | |
725 | ||
726 | case DNS_TRANSACTION_NULL: | |
727 | case DNS_TRANSACTION_PENDING: | |
728 | case DNS_TRANSACTION_VALIDATING: | |
729 | /* Still ongoing */ | |
730 | return 0; | |
731 | ||
732 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 733 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
734 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
735 | goto fail; | |
736 | } | |
737 | ||
b3c6b00a | 738 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
5238e957 | 739 | * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS |
b3c6b00a LP |
740 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar |
741 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
742 | |
743 | case DNS_TRANSACTION_SUCCESS: | |
744 | /* All good. */ | |
745 | break; | |
746 | ||
747 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
748 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
749 | * validationr result */ | |
750 | ||
751 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
752 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
753 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
754 | return 0; | |
755 | ||
942eb2e7 LP |
756 | default: |
757 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
758 | goto fail; | |
759 | } | |
760 | } | |
761 | ||
762 | /* All is ready, we can go and validate */ | |
763 | return 1; | |
764 | ||
765 | fail: | |
766 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
767 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
768 | return 0; | |
769 | } | |
770 | ||
547973de LP |
771 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
772 | int r; | |
773 | ||
774 | assert(t); | |
775 | ||
776 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 777 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
778 | if (r < 0) |
779 | goto fail; | |
942eb2e7 | 780 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
781 | return; |
782 | ||
c02cf2f4 LP |
783 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
784 | * restart the lookup immediately. */ | |
785 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
786 | if (r < 0) |
787 | goto fail; | |
c02cf2f4 LP |
788 | if (r > 0) /* Transaction got restarted... */ |
789 | return; | |
790 | ||
547973de LP |
791 | /* All our auxiliary DNSSEC transactions are complete now. Try |
792 | * to validate our RRset now. */ | |
793 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
794 | if (r == -EBADMSG) { |
795 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
796 | return; | |
797 | } | |
7cc6ed7b LP |
798 | if (r < 0) |
799 | goto fail; | |
547973de | 800 | |
b652d4a2 LP |
801 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
802 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
803 | |
804 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
805 | * that works. */ | |
806 | ||
807 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { | |
808 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
809 | dns_transaction_retry(t, true); | |
810 | return; | |
811 | } | |
812 | ||
813 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
814 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
815 | return; | |
816 | } | |
817 | ||
019036a4 | 818 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
819 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
820 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
821 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
822 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
823 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
824 | return; | |
825 | } | |
826 | ||
1e02e182 LP |
827 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
828 | dns_server_warn_downgrade(t->server); | |
829 | ||
547973de LP |
830 | dns_transaction_cache_answer(t); |
831 | ||
832 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
833 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
834 | else | |
3bbdc31d | 835 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
836 | |
837 | return; | |
838 | ||
839 | fail: | |
fd8a3017 | 840 | dns_transaction_complete_errno(t, r); |
547973de LP |
841 | } |
842 | ||
eac7cda2 LP |
843 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
844 | int r; | |
845 | ||
846 | assert(t); | |
847 | ||
848 | /* Checks whether the answer is positive, i.e. either a direct | |
849 | * answer to the question, or a CNAME/DNAME for it */ | |
850 | ||
42df9532 | 851 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), flags); |
eac7cda2 LP |
852 | if (r != 0) |
853 | return r; | |
854 | ||
42df9532 | 855 | r = dns_answer_find_cname_or_dname(t->answer, dns_transaction_key(t), NULL, flags); |
eac7cda2 LP |
856 | if (r != 0) |
857 | return r; | |
858 | ||
859 | return false; | |
860 | } | |
861 | ||
862 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
863 | int r; | |
864 | ||
865 | assert(t); | |
866 | ||
867 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
868 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
869 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
870 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
871 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
872 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
873 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
874 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
875 | * incomplete CNAME/DNAME chain. | |
876 | * | |
877 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
878 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
879 | * lookup. */ | |
880 | ||
881 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
882 | return 0; | |
883 | ||
884 | r = dns_transaction_has_positive_answer(t, NULL); | |
885 | if (r <= 0) | |
886 | return r; | |
887 | ||
888 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
889 | return 0; | |
890 | } | |
891 | ||
ec2c5e43 LP |
892 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
893 | int r; | |
894 | ||
895 | assert(t); | |
896 | assert(p); | |
9df3ba6c TG |
897 | assert(t->scope); |
898 | assert(t->scope->manager); | |
ec2c5e43 | 899 | |
5a7e41a3 LP |
900 | if (t->state != DNS_TRANSACTION_PENDING) |
901 | return; | |
902 | ||
ec2c5e43 LP |
903 | /* Note that this call might invalidate the query. Callers |
904 | * should hence not attempt to access the query or transaction | |
905 | * after calling this function. */ | |
906 | ||
11833205 ZJS |
907 | log_debug("Processing incoming packet on transaction %" PRIu16" (rcode=%s).", |
908 | t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); | |
b5efcf29 | 909 | |
106784eb | 910 | switch (t->scope->protocol) { |
b5efcf29 | 911 | |
106784eb | 912 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 913 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 914 | |
97ebebbc | 915 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
916 | return; |
917 | ||
918 | if (p->family != t->scope->family) | |
919 | return; | |
920 | ||
921 | /* Tentative packets are not full responses but still | |
922 | * useful for identifying uniqueness conflicts during | |
923 | * probing. */ | |
8b757a38 | 924 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
925 | dns_transaction_tentative(t, p); |
926 | return; | |
927 | } | |
106784eb DM |
928 | |
929 | break; | |
930 | ||
4e5bf5e1 | 931 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 932 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
933 | |
934 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
935 | return; |
936 | ||
937 | if (p->family != t->scope->family) | |
938 | return; | |
939 | ||
940 | break; | |
941 | ||
106784eb | 942 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
943 | /* Note that we do not need to verify the |
944 | * addresses/port numbers of incoming traffic, as we | |
945 | * invoked connect() on our UDP socket in which case | |
946 | * the kernel already does the needed verification for | |
947 | * us. */ | |
106784eb DM |
948 | break; |
949 | ||
950 | default: | |
9c56a6f3 | 951 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
952 | } |
953 | ||
ec2c5e43 LP |
954 | if (t->received != p) { |
955 | dns_packet_unref(t->received); | |
956 | t->received = dns_packet_ref(p); | |
957 | } | |
958 | ||
c3bc53e6 LP |
959 | t->answer_source = DNS_TRANSACTION_NETWORK; |
960 | ||
ec2c5e43 LP |
961 | if (p->ipproto == IPPROTO_TCP) { |
962 | if (DNS_PACKET_TC(p)) { | |
963 | /* Truncated via TCP? Somebody must be fucking with us */ | |
964 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
965 | return; | |
966 | } | |
967 | ||
968 | if (DNS_PACKET_ID(p) != t->id) { | |
969 | /* Not the reply to our query? Somebody must be fucking with us */ | |
970 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
971 | return; | |
972 | } | |
973 | } | |
974 | ||
9df3ba6c | 975 | switch (t->scope->protocol) { |
8af5b883 | 976 | |
9df3ba6c TG |
977 | case DNS_PROTOCOL_DNS: |
978 | assert(t->server); | |
979 | ||
4e0b8b17 TG |
980 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
981 | ||
8af5b883 | 982 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 983 | |
7d581a65 | 984 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
44db02d0 | 985 | |
7d581a65 | 986 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade |
44db02d0 LP |
987 | * this transaction anymore, but let's see if it might make sense to send the request |
988 | * to a different DNS server instead. If not let's process the response, and accept the | |
7d581a65 LP |
989 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate |
990 | * packet loss, but is not going to give us better rcodes should we actually have | |
991 | * managed to get them already at UDP level. */ | |
992 | ||
44db02d0 LP |
993 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { |
994 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
995 | dns_transaction_retry(t, true); | |
996 | return; | |
997 | } | |
998 | ||
999 | /* Give up, accept the rcode */ | |
d001e0a3 LP |
1000 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
1001 | break; | |
1002 | } | |
1003 | ||
1004 | /* Reduce this feature level by one and try again. */ | |
5d67a7ae IT |
1005 | switch (t->current_feature_level) { |
1006 | case DNS_SERVER_FEATURE_LEVEL_TLS_DO: | |
1007 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN; | |
1008 | break; | |
1009 | case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN + 1: | |
1010 | /* Skip plain TLS when TLS is not supported */ | |
1011 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN - 1; | |
1012 | break; | |
1013 | default: | |
1014 | t->clamp_feature_level = t->current_feature_level - 1; | |
1015 | } | |
d001e0a3 LP |
1016 | |
1017 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
1018 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
1019 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
1020 | ||
1021 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 1022 | return; |
eb08640a LP |
1023 | } |
1024 | ||
1025 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
1026 | /* This server refused our request? If so, try again, use a different server */ | |
1027 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
1028 | dns_transaction_retry(t, true /* pick a new server */); | |
1029 | return; | |
1030 | } | |
1031 | ||
1032 | if (DNS_PACKET_TC(p)) | |
274b8748 | 1033 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
1034 | |
1035 | break; | |
8af5b883 | 1036 | |
9df3ba6c TG |
1037 | case DNS_PROTOCOL_LLMNR: |
1038 | case DNS_PROTOCOL_MDNS: | |
5777c613 | 1039 | dns_scope_packet_received(t->scope, p->timestamp - t->start_usec); |
9df3ba6c | 1040 | break; |
8af5b883 | 1041 | |
9df3ba6c | 1042 | default: |
8af5b883 | 1043 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
1044 | } |
1045 | ||
ec2c5e43 | 1046 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
1047 | |
1048 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
1049 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
1050 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1051 | return; | |
1052 | } | |
1053 | ||
f757cd85 LP |
1054 | log_debug("Reply truncated, retrying via TCP."); |
1055 | ||
ec2c5e43 | 1056 | /* Response was truncated, let's try again with good old TCP */ |
98767d75 | 1057 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 LP |
1058 | if (r == -ESRCH) { |
1059 | /* No servers found? Damn! */ | |
1060 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1061 | return; | |
1062 | } | |
91adc4db LP |
1063 | if (r == -EOPNOTSUPP) { |
1064 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1065 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1066 | return; | |
1067 | } | |
ec2c5e43 | 1068 | if (r < 0) { |
8af5b883 | 1069 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 1070 | * we immediately give up */ |
7cc6ed7b LP |
1071 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1072 | goto fail; | |
ec2c5e43 LP |
1073 | |
1074 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 1075 | dns_transaction_retry(t, true); |
ec2c5e43 | 1076 | } |
2a6658ef LP |
1077 | |
1078 | return; | |
ec2c5e43 LP |
1079 | } |
1080 | ||
de54e62b | 1081 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
1082 | r = dns_packet_extract(p); |
1083 | if (r < 0) { | |
1084 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1085 | return; | |
1086 | } | |
1087 | ||
ed9717fc | 1088 | if (t->server) { |
d001e0a3 LP |
1089 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1090 | * rcode and subsequently downgraded the protocol */ | |
1091 | ||
1092 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1093 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1094 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1095 | ||
1096 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1097 | if (!p->opt) |
1098 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1099 | ||
d001e0a3 | 1100 | /* Report that we successfully received a packet */ |
dbc4661a | 1101 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, p->size); |
ed9717fc | 1102 | } |
de54e62b | 1103 | |
c02cf2f4 LP |
1104 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1105 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1106 | if (r < 0) |
1107 | goto fail; | |
c02cf2f4 LP |
1108 | if (r > 0) /* Transaction got restarted... */ |
1109 | return; | |
1110 | ||
8facd1ce LP |
1111 | /* When dealing with protocols other than mDNS only consider responses with equivalent query section |
1112 | * to the request. For mDNS this check doesn't make sense, because the section 6 of RFC6762 states | |
1113 | * that "Multicast DNS responses MUST NOT contain any questions in the Question Section". */ | |
1114 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
42df9532 | 1115 | r = dns_packet_is_reply_for(p, dns_transaction_key(t)); |
8facd1ce LP |
1116 | if (r < 0) |
1117 | goto fail; | |
1118 | if (r == 0) { | |
1119 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1120 | return; | |
547493c5 | 1121 | } |
8facd1ce | 1122 | } |
29815b6c | 1123 | |
8facd1ce LP |
1124 | /* Install the answer as answer to the transaction */ |
1125 | dns_answer_unref(t->answer); | |
1126 | t->answer = dns_answer_ref(p->answer); | |
1127 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
1128 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
1129 | t->answer_authenticated = false; | |
79e24931 | 1130 | |
8facd1ce LP |
1131 | r = dns_transaction_fix_rcode(t); |
1132 | if (r < 0) | |
1133 | goto fail; | |
eac7cda2 | 1134 | |
8facd1ce LP |
1135 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1136 | t->block_gc++; | |
1137 | r = dns_transaction_request_dnssec_keys(t); | |
1138 | t->block_gc--; | |
51e399bc | 1139 | |
8facd1ce LP |
1140 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ |
1141 | if (!dns_transaction_gc(t)) | |
1142 | return; | |
51e399bc | 1143 | |
8facd1ce LP |
1144 | /* Requesting additional keys might have resulted in this transaction to fail, since the auxiliary |
1145 | * request failed for some reason. If so, we are not in pending state anymore, and we should exit | |
1146 | * quickly. */ | |
1147 | if (t->state != DNS_TRANSACTION_PENDING) | |
1148 | return; | |
1149 | if (r < 0) | |
1150 | goto fail; | |
1151 | if (r > 0) { | |
1152 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1153 | t->state = DNS_TRANSACTION_VALIDATING; | |
1154 | dns_transaction_close_connection(t); | |
1155 | dns_transaction_stop_timeout(t); | |
1156 | return; | |
547493c5 | 1157 | } |
ec2c5e43 | 1158 | |
547973de | 1159 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1160 | return; |
1161 | ||
1162 | fail: | |
fd8a3017 | 1163 | dns_transaction_complete_errno(t, r); |
ec2c5e43 LP |
1164 | } |
1165 | ||
c19ffd9f TG |
1166 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1167 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1168 | DnsTransaction *t = userdata; | |
1169 | int r; | |
1170 | ||
1171 | assert(t); | |
1172 | assert(t->scope); | |
1173 | ||
1174 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
95d2155a | 1175 | if (ERRNO_IS_DISCONNECT(r)) { |
7e1851e3 | 1176 | usec_t usec; |
c19ffd9f | 1177 | |
f731fd5b ZJS |
1178 | /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the |
1179 | * next recvmsg(). Treat this like a lost packet. */ | |
7e1851e3 | 1180 | |
92ec902a | 1181 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1182 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
3da3cdd5 | 1183 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level); |
7e1851e3 | 1184 | |
d001e0a3 | 1185 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1186 | return 0; |
1187 | } | |
1188 | if (r < 0) { | |
fd8a3017 | 1189 | dns_transaction_complete_errno(t, r); |
7e1851e3 LP |
1190 | return 0; |
1191 | } | |
f731fd5b ZJS |
1192 | if (r == 0) |
1193 | /* Spurious wakeup without any data */ | |
1194 | return 0; | |
7e1851e3 LP |
1195 | |
1196 | r = dns_packet_validate_reply(p); | |
1197 | if (r < 0) { | |
1198 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1199 | return 0; | |
1200 | } | |
1201 | if (r == 0) { | |
e09f605e | 1202 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1203 | return 0; |
1204 | } | |
1205 | ||
1206 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1207 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1208 | return 0; |
1209 | } | |
c19ffd9f | 1210 | |
7e1851e3 | 1211 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1212 | return 0; |
1213 | } | |
1214 | ||
49cce12d | 1215 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1216 | int r; |
1217 | ||
1218 | assert(t); | |
c19ffd9f | 1219 | |
519ef046 | 1220 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1221 | |
519ef046 | 1222 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1223 | if (r < 0) |
1224 | return r; | |
c19ffd9f | 1225 | |
5d67a7ae | 1226 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) |
7d581a65 | 1227 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1228 | |
42df9532 | 1229 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) |
91adc4db LP |
1230 | return -EOPNOTSUPP; |
1231 | ||
519ef046 LP |
1232 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1233 | int fd; | |
1234 | ||
1235 | dns_transaction_close_connection(t); | |
c19ffd9f | 1236 | |
da9de738 | 1237 | fd = dns_scope_socket_udp(t->scope, t->server); |
519ef046 LP |
1238 | if (fd < 0) |
1239 | return fd; | |
1240 | ||
1241 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1242 | if (r < 0) { | |
1243 | safe_close(fd); | |
1244 | return r; | |
1245 | } | |
1246 | ||
aa4a9deb | 1247 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1248 | t->dns_udp_fd = fd; |
1249 | } | |
1250 | ||
274b8748 | 1251 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1252 | if (r < 0) |
1253 | return r; | |
1254 | } else | |
1255 | dns_transaction_close_connection(t); | |
1256 | ||
1257 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1258 | if (r < 0) |
1259 | return r; | |
c19ffd9f | 1260 | |
519ef046 | 1261 | dns_transaction_reset_answer(t); |
be808ea0 | 1262 | |
471d40d9 | 1263 | return 0; |
c19ffd9f TG |
1264 | } |
1265 | ||
ec2c5e43 LP |
1266 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1267 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1268 | |
1269 | assert(s); | |
1270 | assert(t); | |
1271 | ||
ef7ce6df DM |
1272 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1273 | /* Timeout reached? Increase the timeout for the server used */ | |
1274 | switch (t->scope->protocol) { | |
49cce12d | 1275 | |
ef7ce6df DM |
1276 | case DNS_PROTOCOL_DNS: |
1277 | assert(t->server); | |
3da3cdd5 | 1278 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level); |
ef7ce6df | 1279 | break; |
49cce12d | 1280 | |
ef7ce6df DM |
1281 | case DNS_PROTOCOL_LLMNR: |
1282 | case DNS_PROTOCOL_MDNS: | |
1283 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1284 | break; |
49cce12d | 1285 | |
ef7ce6df DM |
1286 | default: |
1287 | assert_not_reached("Invalid DNS protocol."); | |
1288 | } | |
1289 | ||
1290 | if (t->initial_jitter_scheduled) | |
1291 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1292 | } |
1293 | ||
423659ab LP |
1294 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1295 | ||
d001e0a3 | 1296 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1297 | return 0; |
1298 | } | |
1299 | ||
9df3ba6c TG |
1300 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1301 | assert(t); | |
1302 | assert(t->scope); | |
1303 | ||
1304 | switch (t->scope->protocol) { | |
49cce12d | 1305 | |
9df3ba6c | 1306 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1307 | |
1308 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1309 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1310 | * needlessly. */ | |
1311 | if (t->stream) | |
1312 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1313 | ||
dbc4661a | 1314 | return DNS_TIMEOUT_USEC; |
49cce12d | 1315 | |
9df3ba6c | 1316 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1317 | assert(t->n_attempts > 0); |
53fda2bb DR |
1318 | if (t->probing) |
1319 | return MDNS_PROBING_INTERVAL_USEC; | |
1320 | else | |
1321 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1322 | |
11a27c2e | 1323 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1324 | return t->scope->resend_timeout; |
49cce12d | 1325 | |
9df3ba6c TG |
1326 | default: |
1327 | assert_not_reached("Invalid DNS protocol."); | |
1328 | } | |
1329 | } | |
1330 | ||
c842ff24 | 1331 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1332 | int r; |
1333 | ||
1334 | assert(t); | |
1335 | ||
4ea8b443 ZJS |
1336 | /* Returns 0 if dns_transaction_complete() has been called. In that case the transaction and query |
1337 | * candidate objects may have been invalidated and must not be accessed. Returns 1 if the transaction | |
1338 | * has been prepared. */ | |
1339 | ||
f535705a | 1340 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1341 | |
86b112a3 | 1342 | if (!dns_scope_network_good(t->scope)) { |
edbcc1fd LP |
1343 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); |
1344 | return 0; | |
1345 | } | |
1346 | ||
ec2c5e43 | 1347 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
e53b8cc5 ZJS |
1348 | DnsTransactionState result; |
1349 | ||
1350 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) | |
1351 | /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve | |
1352 | * the name. */ | |
1353 | result = DNS_TRANSACTION_NOT_FOUND; | |
1354 | else | |
1355 | result = DNS_TRANSACTION_ATTEMPTS_MAX_REACHED; | |
1356 | ||
1357 | dns_transaction_complete(t, result); | |
ec2c5e43 LP |
1358 | return 0; |
1359 | } | |
1360 | ||
cbe4216d | 1361 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1362 | /* If we already tried via a stream, then we don't |
1363 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1364 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1365 | return 0; | |
1366 | } | |
1367 | ||
1368 | t->n_attempts++; | |
9df3ba6c | 1369 | t->start_usec = ts; |
c61d2b44 LP |
1370 | |
1371 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1372 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1373 | |
0d2cd476 LP |
1374 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1375 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
42df9532 | 1376 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, dns_transaction_key(t), &t->answer); |
0d2cd476 LP |
1377 | if (r < 0) |
1378 | return r; | |
1379 | if (r > 0) { | |
1380 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1381 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1382 | t->answer_authenticated = true; |
0d2cd476 LP |
1383 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1384 | return 0; | |
1385 | } | |
b2b796b8 | 1386 | |
42df9532 LP |
1387 | if (dns_name_is_root(dns_resource_key_name(dns_transaction_key(t))) && |
1388 | dns_transaction_key(t)->type == DNS_TYPE_DS) { | |
b2b796b8 LP |
1389 | |
1390 | /* Hmm, this is a request for the root DS? A | |
1391 | * DS RR doesn't exist in the root zone, and | |
1392 | * if our trust anchor didn't know it either, | |
1393 | * this means we cannot do any DNSSEC logic | |
1394 | * anymore. */ | |
1395 | ||
1ed8c0fb | 1396 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1397 | /* We are in downgrade mode. In this |
1398 | * case, synthesize an unsigned empty | |
1399 | * response, so that the any lookup | |
1400 | * depending on this one can continue | |
1401 | * assuming there was no DS, and hence | |
1402 | * the root zone was unsigned. */ | |
1403 | ||
1404 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1405 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1406 | t->answer_authenticated = false; | |
1407 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1408 | } else | |
1409 | /* If we are not in downgrade mode, | |
1410 | * then fail the lookup, because we | |
1411 | * cannot reasonably answer it. There | |
1412 | * might be DS RRs, but we don't know | |
1413 | * them, and the DNS server won't tell | |
1414 | * them to us (and even if it would, | |
202b76ae | 1415 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1416 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1417 | ||
1418 | return 0; | |
1419 | } | |
0d2cd476 LP |
1420 | } |
1421 | ||
1422 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1423 | * for probing or verifying a zone item. */ |
547973de | 1424 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1425 | |
42df9532 | 1426 | r = dns_zone_lookup(&t->scope->zone, dns_transaction_key(t), dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1427 | if (r < 0) |
1428 | return r; | |
1429 | if (r > 0) { | |
ae6a4bbf | 1430 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1431 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1432 | t->answer_authenticated = true; |
d746bb3e LP |
1433 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1434 | return 0; | |
1435 | } | |
1436 | } | |
1437 | ||
4d926a69 LP |
1438 | /* Check the cache, but only if this transaction is not used |
1439 | * for probing or verifying a zone item. */ | |
547973de | 1440 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1441 | |
4d926a69 LP |
1442 | /* Before trying the cache, let's make sure we figured out a |
1443 | * server to use. Should this cause a change of server this | |
1444 | * might flush the cache. */ | |
5cdb8930 | 1445 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1446 | |
4d926a69 LP |
1447 | /* Let's then prune all outdated entries */ |
1448 | dns_cache_prune(&t->scope->cache); | |
1449 | ||
42df9532 | 1450 | r = dns_cache_lookup(&t->scope->cache, dns_transaction_key(t), t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1451 | if (r < 0) |
1452 | return r; | |
1453 | if (r > 0) { | |
c3bc53e6 | 1454 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1455 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1456 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1457 | else | |
3bbdc31d | 1458 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1459 | return 0; |
1460 | } | |
ec2c5e43 LP |
1461 | } |
1462 | ||
1effe965 DM |
1463 | return 1; |
1464 | } | |
1465 | ||
0afa57e2 | 1466 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
0afa57e2 | 1467 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
7778dfff | 1468 | bool add_known_answers = false; |
0afa57e2 | 1469 | DnsTransaction *other; |
0d5ee47d DR |
1470 | DnsResourceKey *tkey; |
1471 | _cleanup_set_free_ Set *keys = NULL; | |
0afa57e2 | 1472 | unsigned qdcount; |
0d5ee47d | 1473 | unsigned nscount = 0; |
0afa57e2 DM |
1474 | usec_t ts; |
1475 | int r; | |
1476 | ||
1477 | assert(t); | |
1478 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1479 | ||
e5abebab | 1480 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1481 | t->sent = dns_packet_unref(t->sent); |
1482 | ||
1483 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1484 | if (r < 0) | |
1485 | return r; | |
1486 | ||
42df9532 | 1487 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
0afa57e2 DM |
1488 | if (r < 0) |
1489 | return r; | |
1490 | ||
1491 | qdcount = 1; | |
1492 | ||
42df9532 | 1493 | if (dns_key_is_shared(dns_transaction_key(t))) |
7778dfff DM |
1494 | add_known_answers = true; |
1495 | ||
42df9532 LP |
1496 | if (dns_transaction_key(t)->type == DNS_TYPE_ANY) { |
1497 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(t)); | |
0d5ee47d DR |
1498 | if (r < 0) |
1499 | return r; | |
1500 | } | |
1501 | ||
0afa57e2 DM |
1502 | /* |
1503 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1504 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
5238e957 | 1505 | * in our current scope, and see whether their timing constraints allow them to be sent. |
0afa57e2 DM |
1506 | */ |
1507 | ||
1508 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1509 | ||
1510 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1511 | ||
1512 | /* Skip ourselves */ | |
1513 | if (other == t) | |
1514 | continue; | |
1515 | ||
1516 | if (other->state != DNS_TRANSACTION_PENDING) | |
1517 | continue; | |
1518 | ||
1519 | if (other->next_attempt_after > ts) | |
1520 | continue; | |
1521 | ||
1522 | if (qdcount >= UINT16_MAX) | |
1523 | break; | |
1524 | ||
42df9532 | 1525 | r = dns_packet_append_key(p, dns_transaction_key(other), 0, NULL); |
0afa57e2 DM |
1526 | |
1527 | /* | |
1528 | * If we can't stuff more questions into the packet, just give up. | |
1529 | * One of the 'other' transactions will fire later and take care of the rest. | |
1530 | */ | |
1531 | if (r == -EMSGSIZE) | |
1532 | break; | |
1533 | ||
1534 | if (r < 0) | |
1535 | return r; | |
1536 | ||
c842ff24 | 1537 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1538 | if (r <= 0) |
1539 | continue; | |
1540 | ||
1541 | ts += transaction_get_resend_timeout(other); | |
1542 | ||
1543 | r = sd_event_add_time( | |
1544 | other->scope->manager->event, | |
1545 | &other->timeout_event_source, | |
1546 | clock_boottime_or_monotonic(), | |
1547 | ts, 0, | |
1548 | on_transaction_timeout, other); | |
1549 | if (r < 0) | |
1550 | return r; | |
1551 | ||
ff537038 | 1552 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1553 | |
0afa57e2 DM |
1554 | other->state = DNS_TRANSACTION_PENDING; |
1555 | other->next_attempt_after = ts; | |
1556 | ||
313cefa1 | 1557 | qdcount++; |
7778dfff | 1558 | |
42df9532 | 1559 | if (dns_key_is_shared(dns_transaction_key(other))) |
7778dfff | 1560 | add_known_answers = true; |
0d5ee47d | 1561 | |
42df9532 LP |
1562 | if (dns_transaction_key(other)->type == DNS_TYPE_ANY) { |
1563 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(other)); | |
0d5ee47d DR |
1564 | if (r < 0) |
1565 | return r; | |
1566 | } | |
0afa57e2 DM |
1567 | } |
1568 | ||
1569 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1570 | |
7778dfff DM |
1571 | /* Append known answer section if we're asking for any shared record */ |
1572 | if (add_known_answers) { | |
1573 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1574 | if (r < 0) | |
1575 | return r; | |
1576 | } | |
1577 | ||
90e74a66 | 1578 | SET_FOREACH(tkey, keys) { |
0d5ee47d DR |
1579 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
1580 | bool tentative; | |
1581 | ||
1582 | r = dns_zone_lookup(&t->scope->zone, tkey, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1583 | if (r < 0) | |
1584 | return r; | |
1585 | ||
1586 | r = dns_packet_append_answer(p, answer); | |
1587 | if (r < 0) | |
1588 | return r; | |
1589 | ||
1590 | nscount += dns_answer_size(answer); | |
1591 | } | |
1592 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1593 | ||
1cc6c93a | 1594 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1595 | |
1596 | return 0; | |
1597 | } | |
1598 | ||
1599 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1600 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1601 | int r; | |
1602 | ||
1603 | assert(t); | |
1604 | ||
1605 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1606 | return dns_transaction_make_packet_mdns(t); | |
1607 | ||
1608 | if (t->sent) | |
1609 | return 0; | |
1610 | ||
b652d4a2 | 1611 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1612 | if (r < 0) |
1613 | return r; | |
1614 | ||
42df9532 | 1615 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
0afa57e2 DM |
1616 | if (r < 0) |
1617 | return r; | |
1618 | ||
1619 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1620 | DNS_PACKET_HEADER(p)->id = t->id; | |
1621 | ||
1cc6c93a | 1622 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1623 | |
1624 | return 0; | |
1625 | } | |
1626 | ||
1effe965 DM |
1627 | int dns_transaction_go(DnsTransaction *t) { |
1628 | usec_t ts; | |
1629 | int r; | |
202b76ae | 1630 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1631 | |
1632 | assert(t); | |
1633 | ||
4ea8b443 ZJS |
1634 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has |
1635 | * finished now. In the latter case, the transaction and query candidate objects must not be accessed. | |
1636 | */ | |
5278bbfe | 1637 | |
1effe965 | 1638 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1639 | |
c842ff24 | 1640 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1641 | if (r <= 0) |
1642 | return r; | |
1643 | ||
202b76ae | 1644 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1645 | t->id, |
42df9532 | 1646 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
a5784c49 | 1647 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 1648 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 1649 | af_to_name_short(t->scope->family)); |
1effe965 | 1650 | |
ef7ce6df | 1651 | if (!t->initial_jitter_scheduled && |
3742095b | 1652 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1653 | usec_t jitter, accuracy; |
6e068472 LP |
1654 | |
1655 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1656 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1657 | ||
ef7ce6df | 1658 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1659 | |
1660 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1661 | |
1662 | switch (t->scope->protocol) { | |
519ef046 | 1663 | |
ea12bcc7 DM |
1664 | case DNS_PROTOCOL_LLMNR: |
1665 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1666 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1667 | break; | |
519ef046 | 1668 | |
ea12bcc7 DM |
1669 | case DNS_PROTOCOL_MDNS: |
1670 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1671 | jitter += MDNS_JITTER_MIN_USEC; | |
1672 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1673 | break; | |
1674 | default: | |
1675 | assert_not_reached("bad protocol"); | |
1676 | } | |
6e068472 LP |
1677 | |
1678 | r = sd_event_add_time( | |
1679 | t->scope->manager->event, | |
1680 | &t->timeout_event_source, | |
1681 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1682 | ts + jitter, accuracy, |
6e068472 LP |
1683 | on_transaction_timeout, t); |
1684 | if (r < 0) | |
1685 | return r; | |
1686 | ||
aa4a9deb LP |
1687 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1688 | ||
6e068472 | 1689 | t->n_attempts = 0; |
a9da14e1 | 1690 | t->next_attempt_after = ts; |
6e068472 LP |
1691 | t->state = DNS_TRANSACTION_PENDING; |
1692 | ||
ea12bcc7 | 1693 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
4ea8b443 | 1694 | return 1; |
6e068472 LP |
1695 | } |
1696 | ||
ec2c5e43 LP |
1697 | /* Otherwise, we need to ask the network */ |
1698 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1699 | if (r < 0) |
1700 | return r; | |
1701 | ||
1702 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
42df9532 LP |
1703 | (dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "in-addr.arpa") > 0 || |
1704 | dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1705 | |
1706 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1707 | * always be made via TCP on LLMNR */ | |
98767d75 | 1708 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1709 | } else { |
be808ea0 TG |
1710 | /* Try via UDP, and if that fails due to large size or lack of |
1711 | * support try via TCP */ | |
49cce12d | 1712 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1713 | if (r == -EMSGSIZE) |
1714 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1715 | else if (r == -EAGAIN) |
6c0bacc1 | 1716 | log_debug("Sending query via TCP since UDP isn't supported or DNS-over-TLS is selected."); |
4c701096 | 1717 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
98767d75 | 1718 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1719 | } |
be808ea0 | 1720 | |
ec2c5e43 LP |
1721 | if (r == -ESRCH) { |
1722 | /* No servers to send this to? */ | |
1723 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1724 | return 0; | |
91adc4db LP |
1725 | } |
1726 | if (r == -EOPNOTSUPP) { | |
1727 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1728 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1729 | return 0; | |
1730 | } | |
95d2155a | 1731 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(r)) { |
e94968ba | 1732 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1733 | * answer this request with this protocol. */ |
1734 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1735 | return 0; | |
1736 | } | |
91adc4db | 1737 | if (r < 0) { |
7cc6ed7b LP |
1738 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1739 | return r; | |
13b551ac | 1740 | |
ec2c5e43 | 1741 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1742 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1743 | |
1744 | return dns_transaction_go(t); | |
1745 | } | |
1746 | ||
a9da14e1 DM |
1747 | ts += transaction_get_resend_timeout(t); |
1748 | ||
9a015429 LP |
1749 | r = sd_event_add_time( |
1750 | t->scope->manager->event, | |
1751 | &t->timeout_event_source, | |
1752 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1753 | ts, 0, |
9a015429 | 1754 | on_transaction_timeout, t); |
ec2c5e43 LP |
1755 | if (r < 0) |
1756 | return r; | |
1757 | ||
aa4a9deb LP |
1758 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1759 | ||
ec2c5e43 | 1760 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1761 | t->next_attempt_after = ts; |
1762 | ||
ec2c5e43 LP |
1763 | return 1; |
1764 | } | |
1765 | ||
f2992dc1 LP |
1766 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1767 | DnsTransaction *n; | |
f2992dc1 LP |
1768 | int r; |
1769 | ||
1770 | assert(t); | |
1771 | assert(aux); | |
1772 | ||
1773 | /* Try to find cyclic dependencies between transaction objects */ | |
1774 | ||
1775 | if (t == aux) | |
1776 | return 1; | |
1777 | ||
90e74a66 | 1778 | SET_FOREACH(n, aux->dnssec_transactions) { |
f2992dc1 LP |
1779 | r = dns_transaction_find_cyclic(t, n); |
1780 | if (r != 0) | |
1781 | return r; | |
1782 | } | |
1783 | ||
3eb6aa00 | 1784 | return 0; |
f2992dc1 LP |
1785 | } |
1786 | ||
547973de | 1787 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
29bd6012 | 1788 | _cleanup_(dns_transaction_gcp) DnsTransaction *aux = NULL; |
547973de LP |
1789 | int r; |
1790 | ||
1791 | assert(t); | |
1792 | assert(ret); | |
1793 | assert(key); | |
1794 | ||
1795 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1796 | if (!aux) { | |
1797 | r = dns_transaction_new(&aux, t->scope, key); | |
1798 | if (r < 0) | |
1799 | return r; | |
1800 | } else { | |
1801 | if (set_contains(t->dnssec_transactions, aux)) { | |
1802 | *ret = aux; | |
1803 | return 0; | |
1804 | } | |
f2992dc1 LP |
1805 | |
1806 | r = dns_transaction_find_cyclic(t, aux); | |
1807 | if (r < 0) | |
1808 | return r; | |
1809 | if (r > 0) { | |
202b76ae ZJS |
1810 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1811 | ||
baaa35ad ZJS |
1812 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), |
1813 | "Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1814 | aux->id, | |
42df9532 | 1815 | dns_resource_key_to_string(dns_transaction_key(t), s, sizeof s), |
baaa35ad | 1816 | t->id, |
42df9532 | 1817 | dns_resource_key_to_string(dns_transaction_key(aux), saux, sizeof saux)); |
f2992dc1 | 1818 | } |
547973de LP |
1819 | } |
1820 | ||
35aa04e9 LP |
1821 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); |
1822 | if (r < 0) | |
29bd6012 | 1823 | return r; |
547973de | 1824 | |
de7fef4b | 1825 | r = set_ensure_put(&t->dnssec_transactions, NULL, aux); |
547973de | 1826 | if (r < 0) |
a75cb4e2 | 1827 | return r; |
547973de | 1828 | |
de7fef4b | 1829 | r = set_ensure_put(&aux->notify_transactions, NULL, t); |
547973de LP |
1830 | if (r < 0) { |
1831 | (void) set_remove(t->dnssec_transactions, aux); | |
29bd6012 | 1832 | return r; |
547973de LP |
1833 | } |
1834 | ||
29bd6012 | 1835 | *ret = TAKE_PTR(aux); |
547973de | 1836 | return 1; |
547973de LP |
1837 | } |
1838 | ||
1839 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1840 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1841 | DnsTransaction *aux; | |
1842 | int r; | |
1843 | ||
1844 | assert(t); | |
1845 | assert(key); | |
1846 | ||
1847 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1848 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1849 | if (r < 0) |
1850 | return r; | |
1851 | if (r > 0) { | |
1852 | r = dns_answer_extend(&t->validated_keys, a); | |
1853 | if (r < 0) | |
1854 | return r; | |
1855 | ||
1856 | return 0; | |
1857 | } | |
1858 | ||
1859 | /* This didn't work, ask for it via the network/cache then. */ | |
1860 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1861 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1862 | return 0; | |
547973de LP |
1863 | if (r < 0) |
1864 | return r; | |
1865 | ||
1866 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1867 | r = dns_transaction_go(aux); | |
1868 | if (r < 0) | |
1869 | return r; | |
1870 | } | |
1871 | ||
f2992dc1 | 1872 | return 1; |
547973de LP |
1873 | } |
1874 | ||
8a516214 LP |
1875 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1876 | int r; | |
1877 | ||
1878 | assert(t); | |
1879 | ||
c629ff58 | 1880 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1881 | * database, either in the global one, or the link-local |
1882 | * one. */ | |
1883 | ||
1884 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1885 | if (r != 0) | |
1886 | return r; | |
1887 | ||
1888 | if (!t->scope->link) | |
1889 | return 0; | |
1890 | ||
7e8a93b7 | 1891 | return link_negative_trust_anchor_lookup(t->scope->link, name); |
8a516214 LP |
1892 | } |
1893 | ||
105e1512 LP |
1894 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1895 | int r; | |
1896 | ||
1897 | assert(t); | |
1898 | ||
1899 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1900 | * RRs to prove it */ | |
1901 | ||
1902 | r = dns_transaction_has_positive_answer(t, NULL); | |
1903 | if (r < 0) | |
1904 | return r; | |
1905 | if (r > 0) | |
1906 | return false; | |
1907 | ||
8e54f5d9 LP |
1908 | /* Is this key explicitly listed as a negative trust anchor? |
1909 | * If so, it's nothing we need to care about */ | |
42df9532 | 1910 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
1911 | if (r < 0) |
1912 | return r; | |
1913 | if (r > 0) | |
1914 | return false; | |
1915 | ||
105e1512 LP |
1916 | /* The answer does not contain any RRs that match to the |
1917 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1918 | * included. If not, the answer is unsigned. */ | |
1919 | ||
1920 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1921 | if (r < 0) | |
1922 | return r; | |
1923 | if (r > 0) | |
1924 | return false; | |
1925 | ||
1926 | return true; | |
1927 | } | |
1928 | ||
1929 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1930 | int r; | |
1931 | ||
1932 | assert(t); | |
1933 | assert(rr); | |
1934 | ||
1935 | /* Check if the specified RR is the "primary" response, | |
1936 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1937 | * CNAME/DNAME for it. */ |
105e1512 | 1938 | |
42df9532 | 1939 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
1940 | if (r != 0) |
1941 | return r; | |
1942 | ||
42df9532 | 1943 | return dns_resource_key_match_cname_or_dname(dns_transaction_key(t), rr->key, NULL); |
105e1512 LP |
1944 | } |
1945 | ||
92ec902a LP |
1946 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1947 | assert(t); | |
1948 | ||
1949 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1950 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1951 | ||
1952 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1953 | return false; | |
1954 | ||
1955 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1956 | * be supported, hence return true. */ | |
1957 | if (!t->server) | |
1958 | return true; | |
1959 | ||
d001e0a3 LP |
1960 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1961 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1962 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1963 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1964 | |
1965 | return dns_server_dnssec_supported(t->server); | |
1966 | } | |
1967 | ||
1968 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1969 | DnsTransaction *dt; | |
92ec902a LP |
1970 | |
1971 | assert(t); | |
1972 | ||
1973 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1974 | ||
1975 | if (!dns_transaction_dnssec_supported(t)) | |
1976 | return false; | |
1977 | ||
90e74a66 | 1978 | SET_FOREACH(dt, t->dnssec_transactions) |
92ec902a LP |
1979 | if (!dns_transaction_dnssec_supported(dt)) |
1980 | return false; | |
1981 | ||
1982 | return true; | |
1983 | } | |
1984 | ||
547973de LP |
1985 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1986 | DnsResourceRecord *rr; | |
105e1512 | 1987 | |
547973de LP |
1988 | int r; |
1989 | ||
1990 | assert(t); | |
1991 | ||
105e1512 LP |
1992 | /* |
1993 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1994 | * we can verify signatures or prove that RRs are rightfully | |
1995 | * unsigned. Specifically: | |
1996 | * | |
1997 | * - For RRSIG we get the matching DNSKEY | |
1998 | * - For DNSKEY we get the matching DS | |
1999 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 2000 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 2001 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
2002 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
2003 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
2004 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
2005 | */ | |
2006 | ||
b652d4a2 | 2007 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 2008 | return 0; |
92ec902a LP |
2009 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
2010 | return 0; /* We only need to validate stuff from the network */ | |
2011 | if (!dns_transaction_dnssec_supported(t)) | |
5238e957 | 2012 | return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */ |
b652d4a2 | 2013 | |
547973de LP |
2014 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2015 | ||
105e1512 LP |
2016 | if (dns_type_is_pseudo(rr->key->type)) |
2017 | continue; | |
2018 | ||
8e54f5d9 | 2019 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 2020 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2021 | if (r < 0) |
2022 | return r; | |
2023 | if (r > 0) | |
2024 | continue; | |
2025 | ||
547973de LP |
2026 | switch (rr->key->type) { |
2027 | ||
2028 | case DNS_TYPE_RRSIG: { | |
2029 | /* For each RRSIG we request the matching DNSKEY */ | |
2030 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
2031 | ||
2032 | /* If this RRSIG is about a DNSKEY RR and the | |
2033 | * signer is the same as the owner, then we | |
2034 | * already have the DNSKEY, and we don't have | |
2035 | * to look for more. */ | |
2036 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 2037 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
2038 | if (r < 0) |
2039 | return r; | |
2040 | if (r > 0) | |
2041 | continue; | |
2042 | } | |
2043 | ||
105e1512 LP |
2044 | /* If the signer is not a parent of our |
2045 | * original query, then this is about an | |
2046 | * auxiliary RRset, but not anything we asked | |
2047 | * for. In this case we aren't interested, | |
2048 | * because we don't want to request additional | |
2049 | * RRs for stuff we didn't really ask for, and | |
2050 | * also to avoid request loops, where | |
2051 | * additional RRs from one transaction result | |
5238e957 | 2052 | * in another transaction whose additional RRs |
105e1512 LP |
2053 | * point back to the original transaction, and |
2054 | * we deadlock. */ | |
42df9532 | 2055 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), rr->rrsig.signer); |
547973de LP |
2056 | if (r < 0) |
2057 | return r; | |
2058 | if (r == 0) | |
2059 | continue; | |
2060 | ||
2061 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2062 | if (!dnskey) | |
2063 | return -ENOMEM; | |
2064 | ||
1c02e7ba ZJS |
2065 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2066 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2067 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2068 | if (r < 0) | |
2069 | return r; | |
2070 | break; | |
2071 | } | |
2072 | ||
2073 | case DNS_TYPE_DNSKEY: { | |
2074 | /* For each DNSKEY we request the matching DS */ | |
2075 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2076 | ||
105e1512 LP |
2077 | /* If the DNSKEY we are looking at is not for |
2078 | * zone we are interested in, nor any of its | |
2079 | * parents, we aren't interested, and don't | |
2080 | * request it. After all, we don't want to end | |
2081 | * up in request loops, and want to keep | |
2082 | * additional traffic down. */ | |
2083 | ||
42df9532 | 2084 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2085 | if (r < 0) |
2086 | return r; | |
2087 | if (r == 0) | |
2088 | continue; | |
2089 | ||
1c02e7ba | 2090 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2091 | if (!ds) |
2092 | return -ENOMEM; | |
2093 | ||
1c02e7ba ZJS |
2094 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2095 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2096 | r = dns_transaction_request_dnssec_rr(t, ds); |
2097 | if (r < 0) | |
2098 | return r; | |
547973de | 2099 | |
105e1512 LP |
2100 | break; |
2101 | } | |
2102 | ||
105e1512 LP |
2103 | case DNS_TYPE_SOA: |
2104 | case DNS_TYPE_NS: { | |
2105 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2106 | ||
2107 | /* For an unsigned SOA or NS, try to acquire | |
2108 | * the matching DS RR, as we are at a zone cut | |
2109 | * then, and whether a DS exists tells us | |
2110 | * whether the zone is signed. Do so only if | |
2111 | * this RR matches our original question, | |
2112 | * however. */ | |
2113 | ||
42df9532 | 2114 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
2115 | if (r < 0) |
2116 | return r; | |
6993d264 LP |
2117 | if (r == 0) { |
2118 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
d51c4fca | 2119 | * a negative reply, and we need the SOA RR's TTL in order to cache a negative entry? |
6993d264 LP |
2120 | * If so, we need to validate it, too. */ |
2121 | ||
42df9532 | 2122 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), NULL); |
6993d264 LP |
2123 | if (r < 0) |
2124 | return r; | |
2125 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2126 | * it. */ | |
2127 | continue; | |
d5acaa51 LP |
2128 | |
2129 | /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of | |
2130 | * what we are looking for, otherwise there's no value in it for us. */ | |
42df9532 | 2131 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
d5acaa51 LP |
2132 | if (r < 0) |
2133 | return r; | |
2134 | if (r == 0) | |
2135 | continue; | |
6993d264 | 2136 | } |
105e1512 LP |
2137 | |
2138 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2139 | if (r < 0) | |
2140 | return r; | |
2141 | if (r > 0) | |
2142 | continue; | |
2143 | ||
1c02e7ba | 2144 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2145 | if (!ds) |
2146 | return -ENOMEM; | |
2147 | ||
1c02e7ba ZJS |
2148 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2149 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2150 | r = dns_transaction_request_dnssec_rr(t, ds); |
2151 | if (r < 0) | |
2152 | return r; | |
2153 | ||
2154 | break; | |
105e1512 LP |
2155 | } |
2156 | ||
b63fca62 | 2157 | case DNS_TYPE_DS: |
105e1512 LP |
2158 | case DNS_TYPE_CNAME: |
2159 | case DNS_TYPE_DNAME: { | |
2160 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2161 | const char *name; | |
2162 | ||
2163 | /* CNAMEs and DNAMEs cannot be located at a | |
2164 | * zone apex, hence ask for the parent SOA for | |
2165 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2166 | * apex. But do all that only if this is | |
2167 | * actually a response to our original | |
b63fca62 LP |
2168 | * question. |
2169 | * | |
2170 | * Similar for DS RRs, which are signed when | |
2171 | * the parent SOA is signed. */ | |
105e1512 LP |
2172 | |
2173 | r = dns_transaction_is_primary_response(t, rr); | |
2174 | if (r < 0) | |
2175 | return r; | |
2176 | if (r == 0) | |
2177 | continue; | |
2178 | ||
2179 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2180 | if (r < 0) | |
2181 | return r; | |
2182 | if (r > 0) | |
2183 | continue; | |
2184 | ||
43e6779a LP |
2185 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2186 | if (r < 0) | |
2187 | return r; | |
2188 | if (r > 0) | |
2189 | continue; | |
2190 | ||
1c02e7ba | 2191 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2192 | r = dns_name_parent(&name); |
2193 | if (r < 0) | |
2194 | return r; | |
2195 | if (r == 0) | |
2196 | continue; | |
2197 | ||
2198 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2199 | if (!soa) | |
2200 | return -ENOMEM; | |
2201 | ||
1c02e7ba ZJS |
2202 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2203 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2204 | r = dns_transaction_request_dnssec_rr(t, soa); |
2205 | if (r < 0) | |
2206 | return r; | |
2207 | ||
2208 | break; | |
2209 | } | |
2210 | ||
2211 | default: { | |
2212 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2213 | ||
b63fca62 LP |
2214 | /* For other unsigned RRsets (including |
2215 | * NSEC/NSEC3!), look for proof the zone is | |
2216 | * unsigned, by requesting the SOA RR of the | |
2217 | * zone. However, do so only if they are | |
2218 | * directly relevant to our original | |
105e1512 LP |
2219 | * question. */ |
2220 | ||
2221 | r = dns_transaction_is_primary_response(t, rr); | |
2222 | if (r < 0) | |
2223 | return r; | |
2224 | if (r == 0) | |
2225 | continue; | |
2226 | ||
2227 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2228 | if (r < 0) | |
2229 | return r; | |
2230 | if (r > 0) | |
2231 | continue; | |
2232 | ||
1c02e7ba | 2233 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2234 | if (!soa) |
2235 | return -ENOMEM; | |
2236 | ||
1c02e7ba ZJS |
2237 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2238 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2239 | r = dns_transaction_request_dnssec_rr(t, soa); |
2240 | if (r < 0) | |
2241 | return r; | |
2242 | break; | |
547973de LP |
2243 | }} |
2244 | } | |
2245 | ||
105e1512 LP |
2246 | /* Above, we requested everything necessary to validate what |
2247 | * we got. Now, let's request what we need to validate what we | |
2248 | * didn't get... */ | |
2249 | ||
2250 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2251 | if (r < 0) | |
2252 | return r; | |
2253 | if (r > 0) { | |
2254 | const char *name; | |
4bbc06cc | 2255 | uint16_t type = 0; |
105e1512 | 2256 | |
42df9532 | 2257 | name = dns_resource_key_name(dns_transaction_key(t)); |
105e1512 | 2258 | |
4bbc06cc LP |
2259 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2260 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2261 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2262 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2263 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2264 | * to see if that is signed. */ | |
105e1512 | 2265 | |
42df9532 | 2266 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2267 | r = dns_name_parent(&name); |
4bbc06cc LP |
2268 | if (r > 0) { |
2269 | type = DNS_TYPE_SOA; | |
6d72da2f | 2270 | log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", |
42df9532 | 2271 | name, t->id, dns_resource_key_name(dns_transaction_key(t))); |
4bbc06cc | 2272 | } else |
105e1512 | 2273 | name = NULL; |
4bbc06cc | 2274 | |
42df9532 | 2275 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { |
4bbc06cc LP |
2276 | |
2277 | type = DNS_TYPE_DS; | |
6d72da2f LP |
2278 | log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", |
2279 | name, t->id, name); | |
4bbc06cc LP |
2280 | |
2281 | } else { | |
2282 | type = DNS_TYPE_SOA; | |
6d72da2f LP |
2283 | log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2284 | name, t->id, name); | |
4bbc06cc | 2285 | } |
105e1512 LP |
2286 | |
2287 | if (name) { | |
2288 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2289 | ||
42df9532 | 2290 | soa = dns_resource_key_new(dns_transaction_key(t)->class, type, name); |
105e1512 LP |
2291 | if (!soa) |
2292 | return -ENOMEM; | |
2293 | ||
2294 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2295 | if (r < 0) | |
2296 | return r; | |
2297 | } | |
2298 | } | |
2299 | ||
2300 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2301 | } |
2302 | ||
2303 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2304 | assert(t); |
547973de LP |
2305 | assert(source); |
2306 | ||
942eb2e7 LP |
2307 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2308 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2309 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2310 | |
942eb2e7 LP |
2311 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2312 | dns_transaction_process_dnssec(t); | |
547973de LP |
2313 | } |
2314 | ||
105e1512 LP |
2315 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2316 | DnsResourceRecord *rr; | |
2317 | int ifindex, r; | |
2318 | ||
2319 | assert(t); | |
2320 | ||
2321 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2322 | * RRs from the list of validated keys to the list of | |
2323 | * validated keys. */ | |
2324 | ||
2325 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2326 | ||
96bb7673 | 2327 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2328 | if (r < 0) |
2329 | return r; | |
2330 | if (r == 0) | |
2331 | continue; | |
2332 | ||
2333 | /* If so, the DNSKEY is validated too. */ | |
2334 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2335 | if (r < 0) | |
2336 | return r; | |
2337 | } | |
2338 | ||
2339 | return 0; | |
2340 | } | |
2341 | ||
2342 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2343 | int r; |
2344 | ||
2345 | assert(t); | |
2346 | assert(rr); | |
2347 | ||
105e1512 LP |
2348 | /* Checks if the RR we are looking for must be signed with an |
2349 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2350 | |
b652d4a2 | 2351 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2352 | return false; |
56352fe9 | 2353 | |
105e1512 LP |
2354 | if (dns_type_is_pseudo(rr->key->type)) |
2355 | return -EINVAL; | |
56352fe9 | 2356 | |
1c02e7ba | 2357 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2358 | if (r < 0) |
2359 | return r; | |
2360 | if (r > 0) | |
2361 | return false; | |
2362 | ||
105e1512 | 2363 | switch (rr->key->type) { |
56352fe9 | 2364 | |
105e1512 LP |
2365 | case DNS_TYPE_RRSIG: |
2366 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2367 | return false; | |
2368 | ||
2369 | case DNS_TYPE_SOA: | |
2370 | case DNS_TYPE_NS: { | |
2371 | DnsTransaction *dt; | |
105e1512 | 2372 | |
b63fca62 | 2373 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 | 2374 | |
90e74a66 | 2375 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2376 | |
42df9532 | 2377 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2378 | continue; |
42df9532 | 2379 | if (dns_transaction_key(dt)->type != DNS_TYPE_DS) |
105e1512 LP |
2380 | continue; |
2381 | ||
42df9532 | 2382 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2383 | if (r < 0) |
2384 | return r; | |
2385 | if (r == 0) | |
2386 | continue; | |
2387 | ||
2388 | /* We found a DS transactions for the SOA/NS | |
2389 | * RRs we are looking at. If it discovered signed DS | |
2390 | * RRs, then we need to be signed, too. */ | |
2391 | ||
097a2517 TA |
2392 | if (!dt->answer_authenticated) |
2393 | return false; | |
105e1512 | 2394 | |
42df9532 | 2395 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
105e1512 LP |
2396 | } |
2397 | ||
2398 | /* We found nothing that proves this is safe to leave | |
2399 | * this unauthenticated, hence ask inist on | |
2400 | * authentication. */ | |
2401 | return true; | |
2402 | } | |
2403 | ||
b63fca62 | 2404 | case DNS_TYPE_DS: |
105e1512 LP |
2405 | case DNS_TYPE_CNAME: |
2406 | case DNS_TYPE_DNAME: { | |
2407 | const char *parent = NULL; | |
2408 | DnsTransaction *dt; | |
105e1512 | 2409 | |
b63fca62 LP |
2410 | /* |
2411 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2412 | * | |
2413 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2414 | */ | |
105e1512 | 2415 | |
90e74a66 | 2416 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2417 | |
42df9532 | 2418 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2419 | continue; |
42df9532 | 2420 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2421 | continue; |
2422 | ||
2423 | if (!parent) { | |
1c02e7ba | 2424 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2425 | r = dns_name_parent(&parent); |
2426 | if (r < 0) | |
2427 | return r; | |
2428 | if (r == 0) { | |
b63fca62 LP |
2429 | if (rr->key->type == DNS_TYPE_DS) |
2430 | return true; | |
2431 | ||
105e1512 | 2432 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
baaa35ad ZJS |
2433 | return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), |
2434 | "Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
105e1512 LP |
2435 | } |
2436 | } | |
2437 | ||
42df9532 | 2438 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), parent); |
105e1512 LP |
2439 | if (r < 0) |
2440 | return r; | |
2441 | if (r == 0) | |
2442 | continue; | |
2443 | ||
2444 | return t->answer_authenticated; | |
2445 | } | |
2446 | ||
2447 | return true; | |
2448 | } | |
2449 | ||
2450 | default: { | |
2451 | DnsTransaction *dt; | |
105e1512 | 2452 | |
b63fca62 | 2453 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 | 2454 | |
90e74a66 | 2455 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2456 | |
42df9532 | 2457 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2458 | continue; |
42df9532 | 2459 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2460 | continue; |
2461 | ||
42df9532 | 2462 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2463 | if (r < 0) |
2464 | return r; | |
2465 | if (r == 0) | |
2466 | continue; | |
2467 | ||
2468 | /* We found the transaction that was supposed to find | |
2469 | * the SOA RR for us. It was successful, but found no | |
2470 | * RR for us. This means we are not at a zone cut. In | |
2471 | * this case, we require authentication if the SOA | |
2472 | * lookup was authenticated too. */ | |
2473 | return t->answer_authenticated; | |
2474 | } | |
2475 | ||
2476 | return true; | |
2477 | }} | |
56352fe9 LP |
2478 | } |
2479 | ||
d33b6cf3 LP |
2480 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2481 | DnsTransaction *dt; | |
2482 | const char *tld; | |
d33b6cf3 LP |
2483 | int r; |
2484 | ||
2485 | /* If DNSSEC downgrade mode is on, checks whether the | |
2486 | * specified RR is one level below a TLD we have proven not to | |
2487 | * exist. In such a case we assume that this is a private | |
2488 | * domain, and permit it. | |
2489 | * | |
2490 | * This detects cases like the Fritz!Box router networks. Each | |
2491 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2492 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2493 | * are served by the router itself, while requests for the | |
2494 | * "box" domain will result in NXDOMAIN. | |
2495 | * | |
2496 | * Note that this logic is unable to detect cases where a | |
2497 | * router serves a private DNS zone directly under | |
2498 | * non-existing TLD. In such a case we cannot detect whether | |
2499 | * the TLD is supposed to exist or not, as all requests we | |
2500 | * make for it will be answered by the router's zone, and not | |
2501 | * by the root zone. */ | |
2502 | ||
2503 | assert(t); | |
2504 | ||
2505 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2506 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2507 | ||
1c02e7ba | 2508 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2509 | r = dns_name_parent(&tld); |
2510 | if (r < 0) | |
2511 | return r; | |
2512 | if (r == 0) | |
2513 | return false; /* Already the root domain */ | |
2514 | ||
2515 | if (!dns_name_is_single_label(tld)) | |
2516 | return false; | |
2517 | ||
90e74a66 | 2518 | SET_FOREACH(dt, t->dnssec_transactions) { |
d33b6cf3 | 2519 | |
42df9532 | 2520 | if (dns_transaction_key(dt)->class != key->class) |
d33b6cf3 LP |
2521 | continue; |
2522 | ||
42df9532 | 2523 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), tld); |
d33b6cf3 LP |
2524 | if (r < 0) |
2525 | return r; | |
2526 | if (r == 0) | |
2527 | continue; | |
2528 | ||
2529 | /* We found an auxiliary lookup we did for the TLD. If | |
2530 | * that returned with NXDOMAIN, we know the TLD didn't | |
2531 | * exist, and hence this might be a private zone. */ | |
2532 | ||
2533 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2534 | } | |
2535 | ||
2536 | return false; | |
2537 | } | |
2538 | ||
105e1512 | 2539 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2540 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2541 | DnsTransaction *dt; |
2542 | const char *name; | |
4bbc06cc | 2543 | uint16_t type = 0; |
105e1512 | 2544 | int r; |
56352fe9 LP |
2545 | |
2546 | assert(t); | |
2547 | ||
105e1512 LP |
2548 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2549 | * this negative reply */ | |
56352fe9 | 2550 | |
b652d4a2 | 2551 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2552 | return false; |
56352fe9 | 2553 | |
42df9532 | 2554 | if (dns_type_is_pseudo(dns_transaction_key(t)->type)) |
105e1512 LP |
2555 | return -EINVAL; |
2556 | ||
42df9532 | 2557 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
2558 | if (r < 0) |
2559 | return r; | |
2560 | if (r > 0) | |
2561 | return false; | |
2562 | ||
42df9532 | 2563 | r = dns_transaction_in_private_tld(t, dns_transaction_key(t)); |
d33b6cf3 LP |
2564 | if (r < 0) |
2565 | return r; | |
2566 | if (r > 0) { | |
2567 | /* The lookup is from a TLD that is proven not to | |
2568 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2569 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2570 | |
202b76ae | 2571 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
42df9532 | 2572 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
d33b6cf3 LP |
2573 | return false; |
2574 | } | |
2575 | ||
42df9532 | 2576 | name = dns_resource_key_name(dns_transaction_key(t)); |
105e1512 | 2577 | |
42df9532 | 2578 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2579 | |
4bbc06cc LP |
2580 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2581 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2582 | |
2583 | r = dns_name_parent(&name); | |
56352fe9 LP |
2584 | if (r < 0) |
2585 | return r; | |
2586 | if (r == 0) | |
105e1512 | 2587 | return true; |
4bbc06cc LP |
2588 | |
2589 | type = DNS_TYPE_SOA; | |
2590 | ||
42df9532 | 2591 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) |
4bbc06cc LP |
2592 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ |
2593 | type = DNS_TYPE_DS; | |
2594 | else | |
2595 | /* For all other negative replies, check for the SOA lookup */ | |
2596 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2597 | |
2598 | /* For all other RRs we check the SOA on the same level to see | |
2599 | * if it's signed. */ | |
2600 | ||
90e74a66 | 2601 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2602 | |
42df9532 | 2603 | if (dns_transaction_key(dt)->class != dns_transaction_key(t)->class) |
105e1512 | 2604 | continue; |
42df9532 | 2605 | if (dns_transaction_key(dt)->type != type) |
56352fe9 LP |
2606 | continue; |
2607 | ||
42df9532 | 2608 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), name); |
56352fe9 LP |
2609 | if (r < 0) |
2610 | return r; | |
105e1512 LP |
2611 | if (r == 0) |
2612 | continue; | |
2613 | ||
2614 | return dt->answer_authenticated; | |
56352fe9 LP |
2615 | } |
2616 | ||
105e1512 LP |
2617 | /* If in doubt, require NSEC/NSEC3 */ |
2618 | return true; | |
56352fe9 LP |
2619 | } |
2620 | ||
94aa7071 LP |
2621 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2622 | DnsResourceRecord *rrsig; | |
2623 | bool found = false; | |
2624 | int r; | |
2625 | ||
2626 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2627 | * the specified RRset is authenticated (i.e. has a matching | |
2628 | * DS RR). */ | |
2629 | ||
1c02e7ba | 2630 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2631 | if (r < 0) |
2632 | return r; | |
2633 | if (r > 0) | |
2634 | return false; | |
2635 | ||
94aa7071 LP |
2636 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2637 | DnsTransaction *dt; | |
94aa7071 LP |
2638 | |
2639 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2640 | if (r < 0) | |
2641 | return r; | |
2642 | if (r == 0) | |
2643 | continue; | |
2644 | ||
90e74a66 | 2645 | SET_FOREACH(dt, t->dnssec_transactions) { |
94aa7071 | 2646 | |
42df9532 | 2647 | if (dns_transaction_key(dt)->class != rr->key->class) |
94aa7071 LP |
2648 | continue; |
2649 | ||
42df9532 | 2650 | if (dns_transaction_key(dt)->type == DNS_TYPE_DNSKEY) { |
94aa7071 | 2651 | |
42df9532 | 2652 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
2653 | if (r < 0) |
2654 | return r; | |
2655 | if (r == 0) | |
2656 | continue; | |
2657 | ||
2658 | /* OK, we found an auxiliary DNSKEY | |
2659 | * lookup. If that lookup is | |
2660 | * authenticated, report this. */ | |
2661 | ||
2662 | if (dt->answer_authenticated) | |
2663 | return true; | |
2664 | ||
2665 | found = true; | |
2666 | ||
42df9532 | 2667 | } else if (dns_transaction_key(dt)->type == DNS_TYPE_DS) { |
94aa7071 | 2668 | |
42df9532 | 2669 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
2670 | if (r < 0) |
2671 | return r; | |
2672 | if (r == 0) | |
2673 | continue; | |
2674 | ||
2675 | /* OK, we found an auxiliary DS | |
2676 | * lookup. If that lookup is | |
2677 | * authenticated and non-zero, we | |
2678 | * won! */ | |
2679 | ||
2680 | if (!dt->answer_authenticated) | |
2681 | return false; | |
2682 | ||
42df9532 | 2683 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
94aa7071 LP |
2684 | } |
2685 | } | |
2686 | } | |
2687 | ||
2688 | return found ? false : -ENXIO; | |
2689 | } | |
2690 | ||
b652d4a2 LP |
2691 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2692 | assert(t); | |
2693 | assert(rr); | |
2694 | ||
2695 | /* We know that the root domain is signed, hence if it appears | |
2696 | * not to be signed, there's a problem with the DNS server */ | |
2697 | ||
2698 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2699 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2700 | } |
2701 | ||
0f87f3e8 LP |
2702 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2703 | DnsResourceRecord *rr; | |
2704 | int r; | |
2705 | ||
2706 | assert(t); | |
2707 | ||
2708 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2709 | * for a key from our trust anchor. Note that we don't care | |
2710 | * whether the DNSKEY can be authenticated or not. It's | |
2711 | * sufficient if it is self-signed. */ | |
2712 | ||
2713 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2714 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2715 | if (r < 0) |
2716 | return r; | |
2717 | } | |
2718 | ||
2719 | return 0; | |
2720 | } | |
2721 | ||
c9c72065 LP |
2722 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2723 | bool changed; | |
2724 | int r; | |
2725 | ||
2726 | assert(t); | |
2727 | ||
2728 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2729 | * our trust anchors database considers revoked. */ | |
2730 | ||
2731 | do { | |
2732 | DnsResourceRecord *rr; | |
2733 | ||
2734 | changed = false; | |
2735 | ||
2736 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2737 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2738 | if (r < 0) | |
2739 | return r; | |
2740 | if (r > 0) { | |
2741 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2742 | if (r < 0) | |
2743 | return r; | |
2744 | ||
2745 | assert(r > 0); | |
2746 | changed = true; | |
2747 | break; | |
2748 | } | |
2749 | } | |
2750 | } while (changed); | |
2751 | ||
2752 | return 0; | |
2753 | } | |
2754 | ||
942eb2e7 LP |
2755 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2756 | DnsTransaction *dt; | |
942eb2e7 LP |
2757 | int r; |
2758 | ||
2759 | assert(t); | |
2760 | ||
2761 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2762 | ||
90e74a66 | 2763 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
2764 | |
2765 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2766 | continue; | |
2767 | ||
2768 | if (!dt->answer_authenticated) | |
2769 | continue; | |
2770 | ||
2771 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2772 | if (r < 0) | |
2773 | return r; | |
2774 | } | |
2775 | ||
2776 | return 0; | |
2777 | } | |
2778 | ||
c690b20a ZJS |
2779 | typedef enum { |
2780 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2781 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2782 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2783 | } Phase; | |
2784 | ||
2785 | static int dnssec_validate_records( | |
2786 | DnsTransaction *t, | |
2787 | Phase phase, | |
2788 | bool *have_nsec, | |
2789 | DnsAnswer **validated) { | |
2790 | ||
547973de | 2791 | DnsResourceRecord *rr; |
56352fe9 | 2792 | int r; |
547973de | 2793 | |
c690b20a | 2794 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2795 | |
c690b20a ZJS |
2796 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2797 | DnsResourceRecord *rrsig = NULL; | |
2798 | DnssecResult result; | |
547973de | 2799 | |
c690b20a ZJS |
2800 | switch (rr->key->type) { |
2801 | case DNS_TYPE_RRSIG: | |
2802 | continue; | |
547973de | 2803 | |
c690b20a ZJS |
2804 | case DNS_TYPE_DNSKEY: |
2805 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2806 | if (phase == DNSSEC_PHASE_NSEC) | |
2807 | continue; | |
2808 | break; | |
547973de | 2809 | |
c690b20a ZJS |
2810 | case DNS_TYPE_NSEC: |
2811 | case DNS_TYPE_NSEC3: | |
2812 | *have_nsec = true; | |
547973de | 2813 | |
c690b20a ZJS |
2814 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2815 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2816 | continue; | |
2817 | break; | |
105e1512 | 2818 | |
c690b20a ZJS |
2819 | default: |
2820 | /* We validate all other RRs only in the ALL phases */ | |
2821 | if (phase != DNSSEC_PHASE_ALL) | |
2822 | continue; | |
2823 | } | |
b652d4a2 | 2824 | |
c690b20a ZJS |
2825 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2826 | if (r < 0) | |
2827 | return r; | |
547973de | 2828 | |
c690b20a | 2829 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2830 | |
c690b20a | 2831 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2832 | |
c690b20a ZJS |
2833 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2834 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2835 | * the set of validated keys for this transaction. */ | |
547973de | 2836 | |
c690b20a ZJS |
2837 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2838 | if (r < 0) | |
2839 | return r; | |
c9c72065 | 2840 | |
c690b20a ZJS |
2841 | /* Some of the DNSKEYs we just added might already have been revoked, |
2842 | * remove them again in that case. */ | |
2843 | r = dns_transaction_invalidate_revoked_keys(t); | |
2844 | if (r < 0) | |
2845 | return r; | |
2846 | } | |
547973de | 2847 | |
c690b20a ZJS |
2848 | /* Add the validated RRset to the new list of validated |
2849 | * RRsets, and remove it from the unvalidated RRsets. | |
2850 | * We mark the RRset as authenticated and cacheable. */ | |
2851 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2852 | if (r < 0) | |
2853 | return r; | |
547973de | 2854 | |
c690b20a | 2855 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2856 | |
c690b20a ZJS |
2857 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2858 | return 1; | |
2859 | } | |
547973de | 2860 | |
c690b20a ZJS |
2861 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2862 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2863 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2864 | if (phase != DNSSEC_PHASE_ALL) | |
2865 | continue; | |
0c7bff0a | 2866 | |
c690b20a ZJS |
2867 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2868 | bool authenticated = false; | |
2869 | const char *source; | |
0c7bff0a | 2870 | |
c690b20a | 2871 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 2872 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 2873 | |
c690b20a ZJS |
2874 | /* First step, determine the source of synthesis */ |
2875 | r = dns_resource_record_source(rrsig, &source); | |
2876 | if (r < 0) | |
2877 | return r; | |
0c7bff0a | 2878 | |
c690b20a | 2879 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2880 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2881 | source, |
2882 | rrsig->rrsig.signer, | |
2883 | &authenticated); | |
0c7bff0a | 2884 | |
c690b20a ZJS |
2885 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2886 | if (r == 0) | |
2887 | result = DNSSEC_INVALID; | |
2888 | else { | |
2889 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2890 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2891 | if (r < 0) | |
2892 | return r; | |
2893 | ||
2894 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2895 | ||
2896 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2897 | return 1; | |
0c7bff0a | 2898 | } |
c690b20a | 2899 | } |
0c7bff0a | 2900 | |
c690b20a ZJS |
2901 | if (result == DNSSEC_NO_SIGNATURE) { |
2902 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2903 | if (r < 0) |
2904 | return r; | |
c690b20a ZJS |
2905 | if (r == 0) { |
2906 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 2907 | * but remember that this is by no means authenticated. */ |
c690b20a ZJS |
2908 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
2909 | if (r < 0) | |
2910 | return r; | |
2911 | ||
2912 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2913 | return 1; | |
2914 | } | |
547973de | 2915 | |
c690b20a ZJS |
2916 | r = dns_transaction_known_signed(t, rr); |
2917 | if (r < 0) | |
2918 | return r; | |
2919 | if (r > 0) { | |
2920 | /* This is an RR we know has to be signed. If it isn't this means | |
2921 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2922 | |
c690b20a | 2923 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2924 | |
c690b20a | 2925 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2926 | |
c690b20a | 2927 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2928 | |
c690b20a | 2929 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2930 | if (r < 0) |
2931 | return r; | |
547973de | 2932 | |
c690b20a ZJS |
2933 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2934 | return 1; | |
2935 | } | |
a150ff5e | 2936 | |
c690b20a ZJS |
2937 | /* Otherwise, fail */ |
2938 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2939 | return 0; | |
f3cf586d | 2940 | } |
547973de | 2941 | |
c690b20a ZJS |
2942 | r = dns_transaction_in_private_tld(t, rr->key); |
2943 | if (r < 0) | |
2944 | return r; | |
2945 | if (r > 0) { | |
202b76ae | 2946 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2947 | |
c690b20a ZJS |
2948 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2949 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2950 | |
202b76ae ZJS |
2951 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2952 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2953 | |
c690b20a | 2954 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2955 | if (r < 0) |
2956 | return r; | |
0c7bff0a | 2957 | |
c690b20a ZJS |
2958 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2959 | return 1; | |
2960 | } | |
2961 | } | |
0c7bff0a | 2962 | |
c690b20a ZJS |
2963 | if (IN_SET(result, |
2964 | DNSSEC_MISSING_KEY, | |
2965 | DNSSEC_SIGNATURE_EXPIRED, | |
2966 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2967 | |
c690b20a ZJS |
2968 | r = dns_transaction_dnskey_authenticated(t, rr); |
2969 | if (r < 0 && r != -ENXIO) | |
2970 | return r; | |
2971 | if (r == 0) { | |
2972 | /* The DNSKEY transaction was not authenticated, this means there's | |
2973 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2974 | |
c690b20a | 2975 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2976 | if (r < 0) |
2977 | return r; | |
b652d4a2 | 2978 | |
c690b20a ZJS |
2979 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2980 | return 1; | |
2981 | } | |
2982 | } | |
b652d4a2 | 2983 | |
c690b20a ZJS |
2984 | r = dns_transaction_is_primary_response(t, rr); |
2985 | if (r < 0) | |
2986 | return r; | |
2987 | if (r > 0) { | |
2988 | /* Look for a matching DNAME for this CNAME */ | |
2989 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2990 | if (r < 0) | |
2991 | return r; | |
2992 | if (r == 0) { | |
2993 | /* Also look among the stuff we already validated */ | |
2994 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2995 | if (r < 0) |
2996 | return r; | |
c690b20a | 2997 | } |
d33b6cf3 | 2998 | |
c690b20a ZJS |
2999 | if (r == 0) { |
3000 | if (IN_SET(result, | |
3001 | DNSSEC_INVALID, | |
3002 | DNSSEC_SIGNATURE_EXPIRED, | |
3003 | DNSSEC_NO_SIGNATURE)) | |
3004 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
3005 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
3006 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
3007 | ||
3008 | /* This is a primary response to our question, and it failed validation. | |
3009 | * That's fatal. */ | |
3010 | t->answer_dnssec_result = result; | |
3011 | return 0; | |
3012 | } | |
d33b6cf3 | 3013 | |
c690b20a ZJS |
3014 | /* This is a primary response, but we do have a DNAME RR |
3015 | * in the RR that can replay this CNAME, hence rely on | |
3016 | * that, and we can remove the CNAME in favour of it. */ | |
3017 | } | |
d33b6cf3 | 3018 | |
c690b20a ZJS |
3019 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
3020 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
3021 | if (r < 0) | |
3022 | return r; | |
d33b6cf3 | 3023 | |
c690b20a ZJS |
3024 | /* We dropped something from the answer, start from the beginning. */ |
3025 | return 1; | |
3026 | } | |
f3cf586d | 3027 | |
c690b20a ZJS |
3028 | return 2; /* Finito. */ |
3029 | } | |
94aa7071 | 3030 | |
c690b20a ZJS |
3031 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
3032 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
3033 | Phase phase; | |
3034 | DnsAnswerFlags flags; | |
3035 | int r; | |
202b76ae | 3036 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 3037 | |
c690b20a | 3038 | assert(t); |
94aa7071 | 3039 | |
c690b20a ZJS |
3040 | /* We have now collected all DS and DNSKEY RRs in |
3041 | * t->validated_keys, let's see which RRs we can now | |
3042 | * authenticate with that. */ | |
94aa7071 | 3043 | |
c690b20a ZJS |
3044 | if (t->scope->dnssec_mode == DNSSEC_NO) |
3045 | return 0; | |
a150ff5e | 3046 | |
c690b20a ZJS |
3047 | /* Already validated */ |
3048 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
3049 | return 0; | |
105e1512 | 3050 | |
c690b20a ZJS |
3051 | /* Our own stuff needs no validation */ |
3052 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
3053 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
3054 | t->answer_authenticated = true; | |
3055 | return 0; | |
3056 | } | |
a150ff5e | 3057 | |
c690b20a ZJS |
3058 | /* Cached stuff is not affected by validation. */ |
3059 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
3060 | return 0; | |
f3cf586d | 3061 | |
c690b20a ZJS |
3062 | if (!dns_transaction_dnssec_supported_full(t)) { |
3063 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3064 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3065 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3066 | return 0; |
3067 | } | |
f3cf586d | 3068 | |
202b76ae ZJS |
3069 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3070 | t->id, | |
42df9532 | 3071 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
547973de | 3072 | |
c690b20a ZJS |
3073 | /* First, see if this response contains any revoked trust |
3074 | * anchors we care about */ | |
3075 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3076 | if (r < 0) | |
3077 | return r; | |
43e6779a | 3078 | |
c690b20a ZJS |
3079 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3080 | r = dns_transaction_copy_validated(t); | |
3081 | if (r < 0) | |
3082 | return r; | |
43e6779a | 3083 | |
c690b20a ZJS |
3084 | /* Second, see if there are DNSKEYs we already know a |
3085 | * validated DS for. */ | |
3086 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3087 | if (r < 0) | |
3088 | return r; | |
43e6779a | 3089 | |
c690b20a ZJS |
3090 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3091 | * anchor says are revoked. After all we might have marked | |
3092 | * some keys revoked above, but they might still be lingering | |
3093 | * in our validated_keys list. */ | |
3094 | r = dns_transaction_invalidate_revoked_keys(t); | |
3095 | if (r < 0) | |
3096 | return r; | |
f3cf586d | 3097 | |
c690b20a ZJS |
3098 | phase = DNSSEC_PHASE_DNSKEY; |
3099 | for (;;) { | |
3100 | bool have_nsec = false; | |
f3cf586d | 3101 | |
c690b20a ZJS |
3102 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3103 | if (r <= 0) | |
3104 | return r; | |
547973de | 3105 | |
c690b20a ZJS |
3106 | /* Try again as long as we managed to achieve something */ |
3107 | if (r == 1) | |
547973de LP |
3108 | continue; |
3109 | ||
c690b20a | 3110 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3111 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3112 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3113 | continue; |
3114 | } | |
3115 | ||
c690b20a ZJS |
3116 | if (phase != DNSSEC_PHASE_ALL) { |
3117 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3118 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3119 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3120 | continue; |
547973de LP |
3121 | } |
3122 | ||
56352fe9 | 3123 | /* We're done */ |
547973de LP |
3124 | break; |
3125 | } | |
3126 | ||
3127 | dns_answer_unref(t->answer); | |
1cc6c93a | 3128 | t->answer = TAKE_PTR(validated); |
547973de | 3129 | |
72667f08 LP |
3130 | /* At this point the answer only contains validated |
3131 | * RRsets. Now, let's see if it actually answers the question | |
3132 | * we asked. If so, great! If it doesn't, then see if | |
3133 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3134 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3135 | if (r > 0) { |
105e1512 LP |
3136 | /* Yes, it answers the question! */ |
3137 | ||
3138 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3139 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3140 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3141 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3142 | t->answer_authenticated = true; | |
3143 | } else { | |
3144 | /* The answer is not fully authenticated. */ | |
019036a4 | 3145 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3146 | t->answer_authenticated = false; |
3147 | } | |
3148 | ||
72667f08 LP |
3149 | } else if (r == 0) { |
3150 | DnssecNsecResult nr; | |
ed29bfdc | 3151 | bool authenticated = false; |
72667f08 LP |
3152 | |
3153 | /* Bummer! Let's check NSEC/NSEC3 */ | |
42df9532 | 3154 | r = dnssec_nsec_test(t->answer, dns_transaction_key(t), &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3155 | if (r < 0) |
3156 | return r; | |
3157 | ||
3158 | switch (nr) { | |
3159 | ||
3160 | case DNSSEC_NSEC_NXDOMAIN: | |
3161 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3162 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3163 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3164 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3165 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3166 | |
42df9532 | 3167 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3168 | break; |
3169 | ||
3170 | case DNSSEC_NSEC_NODATA: | |
3171 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3172 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3173 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3174 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3175 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3176 | |
42df9532 | 3177 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3178 | break; |
3179 | ||
105e1512 LP |
3180 | case DNSSEC_NSEC_OPTOUT: |
3181 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3182 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3183 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3184 | t->answer_authenticated = false; |
7aa8ce98 | 3185 | |
42df9532 | 3186 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3187 | break; |
3188 | ||
72667f08 LP |
3189 | case DNSSEC_NSEC_NO_RR: |
3190 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3191 | |
3192 | r = dns_transaction_requires_nsec(t); | |
3193 | if (r < 0) | |
3194 | return r; | |
7aa8ce98 | 3195 | if (r > 0) { |
019036a4 | 3196 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
42df9532 | 3197 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
7aa8ce98 | 3198 | } else { |
019036a4 | 3199 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3200 | t->answer_authenticated = false; |
42df9532 | 3201 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3202 | } |
3203 | ||
3204 | break; | |
3205 | ||
3206 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3207 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3208 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
42df9532 | 3209 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, dns_transaction_key(t)); |
72667f08 LP |
3210 | break; |
3211 | ||
3212 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3213 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3214 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3215 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
42df9532 | 3216 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
72667f08 LP |
3217 | break; |
3218 | ||
3219 | default: | |
3220 | assert_not_reached("Unexpected NSEC result."); | |
3221 | } | |
3222 | } | |
3223 | ||
547973de LP |
3224 | return 1; |
3225 | } | |
3226 | ||
ec2c5e43 LP |
3227 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3228 | [DNS_TRANSACTION_NULL] = "null", | |
3229 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3230 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3231 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3232 | [DNS_TRANSACTION_SUCCESS] = "success", |
3233 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3234 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3235 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3236 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3237 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3238 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3239 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3240 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3241 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3242 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3243 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3244 | }; |
3245 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3246 | |
3247 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3248 | [DNS_TRANSACTION_NETWORK] = "network", | |
3249 | [DNS_TRANSACTION_CACHE] = "cache", | |
3250 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3251 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3252 | }; |
3253 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |