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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
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" |
3ffd4af2 LP |
9 | #include "fd-util.h" |
10 | #include "random-util.h" | |
7778dfff | 11 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
12 | #include "resolved-dns-transaction.h" |
13 | #include "resolved-llmnr.h" | |
56ddbf10 | 14 | #if ENABLE_DNS_OVER_TLS |
6016fcb0 | 15 | #include "resolved-dnstls.h" |
5d67a7ae | 16 | #endif |
6016fcb0 | 17 | #include "string-table.h" |
5d67a7ae | 18 | |
b214dc0f | 19 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 20 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 21 | |
dbc4661a MCO |
22 | /* After how much time to repeat classic DNS requests */ |
23 | #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX) | |
24 | ||
c61d2b44 LP |
25 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
26 | assert(t); | |
27 | ||
28 | t->received = dns_packet_unref(t->received); | |
29 | t->answer = dns_answer_unref(t->answer); | |
30 | t->answer_rcode = 0; | |
31 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
32 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
33 | t->answer_authenticated = false; | |
d3760be0 | 34 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 35 | t->answer_errno = 0; |
c61d2b44 LP |
36 | } |
37 | ||
c5b4f861 LP |
38 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
39 | DnsTransaction *z; | |
40 | ||
41 | assert(t); | |
42 | ||
43 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
44 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 45 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
46 | dns_transaction_gc(z); |
47 | } | |
48 | } | |
49 | ||
f32f0e57 LP |
50 | static void dns_transaction_close_connection(DnsTransaction *t) { |
51 | assert(t); | |
52 | ||
b30bf55d LP |
53 | if (t->stream) { |
54 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
98767d75 IT |
55 | LIST_REMOVE(transactions_by_stream, t->stream->transactions, t); |
56 | ||
57 | /* Remove packet in case it's still in the queue */ | |
58 | dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent)); | |
59 | ||
b30bf55d LP |
60 | t->stream = dns_stream_unref(t->stream); |
61 | } | |
62 | ||
f32f0e57 LP |
63 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
64 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
65 | } | |
66 | ||
f535705a | 67 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
68 | assert(t); |
69 | ||
70 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
71 | } |
72 | ||
ec2c5e43 | 73 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 74 | DnsQueryCandidate *c; |
ec2c5e43 | 75 | DnsZoneItem *i; |
547973de | 76 | DnsTransaction *z; |
ec2c5e43 LP |
77 | |
78 | if (!t) | |
79 | return NULL; | |
80 | ||
51e399bc LP |
81 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
82 | ||
f32f0e57 | 83 | dns_transaction_close_connection(t); |
f535705a | 84 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 85 | |
ec2c5e43 | 86 | dns_packet_unref(t->sent); |
c61d2b44 | 87 | dns_transaction_reset_answer(t); |
ec2c5e43 | 88 | |
8300ba21 | 89 | dns_server_unref(t->server); |
ec2c5e43 LP |
90 | |
91 | if (t->scope) { | |
f9ebb22a LP |
92 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
93 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
94 | |
95 | if (t->id != 0) | |
96 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
97 | } | |
98 | ||
547973de | 99 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 100 | set_remove(c->transactions, t); |
547973de | 101 | set_free(t->notify_query_candidates); |
801ad6a6 | 102 | |
35aa04e9 LP |
103 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
104 | set_remove(c->transactions, t); | |
105 | set_free(t->notify_query_candidates_done); | |
106 | ||
547973de | 107 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 108 | i->probe_transaction = NULL; |
547973de LP |
109 | set_free(t->notify_zone_items); |
110 | ||
35aa04e9 LP |
111 | while ((i = set_steal_first(t->notify_zone_items_done))) |
112 | i->probe_transaction = NULL; | |
113 | set_free(t->notify_zone_items_done); | |
114 | ||
547973de LP |
115 | while ((z = set_steal_first(t->notify_transactions))) |
116 | set_remove(z->dnssec_transactions, t); | |
117 | set_free(t->notify_transactions); | |
118 | ||
35aa04e9 LP |
119 | while ((z = set_steal_first(t->notify_transactions_done))) |
120 | set_remove(z->dnssec_transactions, t); | |
121 | set_free(t->notify_transactions_done); | |
122 | ||
c5b4f861 | 123 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
124 | set_free(t->dnssec_transactions); |
125 | ||
126 | dns_answer_unref(t->validated_keys); | |
97cc656c | 127 | dns_resource_key_unref(t->key); |
97cc656c | 128 | |
6b430fdb | 129 | return mfree(t); |
ec2c5e43 LP |
130 | } |
131 | ||
132 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
133 | ||
51e399bc | 134 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
135 | assert(t); |
136 | ||
137 | if (t->block_gc > 0) | |
51e399bc | 138 | return true; |
ec2c5e43 | 139 | |
547973de | 140 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 141 | set_isempty(t->notify_query_candidates_done) && |
547973de | 142 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
143 | set_isempty(t->notify_zone_items_done) && |
144 | set_isempty(t->notify_transactions) && | |
145 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 146 | dns_transaction_free(t); |
51e399bc LP |
147 | return false; |
148 | } | |
149 | ||
150 | return true; | |
ec2c5e43 LP |
151 | } |
152 | ||
4dd15077 LP |
153 | static uint16_t pick_new_id(Manager *m) { |
154 | uint16_t new_id; | |
155 | ||
156 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
157 | * transactions, and it's much lower than the space of IDs. */ | |
158 | ||
159 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
160 | ||
161 | do | |
162 | random_bytes(&new_id, sizeof(new_id)); | |
163 | while (new_id == 0 || | |
164 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
165 | ||
166 | return new_id; | |
167 | } | |
168 | ||
f52e61da | 169 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
170 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
171 | int r; | |
172 | ||
173 | assert(ret); | |
174 | assert(s); | |
f52e61da | 175 | assert(key); |
ec2c5e43 | 176 | |
9eae2bf3 | 177 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 178 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 179 | return -EINVAL; |
d0129ddb LP |
180 | if (dns_type_is_obsolete(key->type)) |
181 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
182 | |
183 | /* We only support the IN class */ | |
4c701096 | 184 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
185 | return -EOPNOTSUPP; |
186 | ||
b214dc0f LP |
187 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
188 | return -EBUSY; | |
189 | ||
d5099efc | 190 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
191 | if (r < 0) |
192 | return r; | |
193 | ||
f9ebb22a | 194 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
195 | if (r < 0) |
196 | return r; | |
197 | ||
ec2c5e43 LP |
198 | t = new0(DnsTransaction, 1); |
199 | if (!t) | |
200 | return -ENOMEM; | |
201 | ||
4667e00a | 202 | t->dns_udp_fd = -1; |
c3bc53e6 | 203 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 204 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 205 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 206 | t->key = dns_resource_key_ref(key); |
274b8748 | 207 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
d001e0a3 | 208 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 209 | |
4dd15077 | 210 | t->id = pick_new_id(s->manager); |
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, | |
202b76ae | 268 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
269 | dns_protocol_to_string(t->scope->protocol), |
270 | t->scope->link ? t->scope->link->name : "*", | |
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 ZJS |
309 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
310 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
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), |
1e02e182 | 318 | "DNS_SERVER=%s", dns_server_string(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, | |
202b76ae | 333 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
334 | dns_protocol_to_string(t->scope->protocol), |
335 | t->scope->link ? t->scope->link->name : "*", | |
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 | ||
519ef046 LP |
368 | static int dns_transaction_pick_server(DnsTransaction *t) { |
369 | DnsServer *server; | |
370 | ||
371 | assert(t); | |
372 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
373 | ||
d001e0a3 LP |
374 | /* Pick a DNS server and a feature level for it. */ |
375 | ||
519ef046 LP |
376 | server = dns_scope_get_dns_server(t->scope); |
377 | if (!server) | |
378 | return -ESRCH; | |
379 | ||
d001e0a3 LP |
380 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
381 | * different properties. */ | |
382 | if (server != t->server) | |
383 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
384 | ||
274b8748 | 385 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 386 | |
d001e0a3 LP |
387 | /* Clamp the feature level if that is requested. */ |
388 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
389 | t->current_feature_level > t->clamp_feature_level) | |
390 | t->current_feature_level = t->clamp_feature_level; | |
391 | ||
392 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
393 | ||
519ef046 LP |
394 | if (server == t->server) |
395 | return 0; | |
396 | ||
397 | dns_server_unref(t->server); | |
398 | t->server = dns_server_ref(server); | |
399 | ||
44db02d0 LP |
400 | t->n_picked_servers ++; |
401 | ||
d001e0a3 LP |
402 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
403 | ||
519ef046 LP |
404 | return 1; |
405 | } | |
406 | ||
d001e0a3 | 407 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
408 | int r; |
409 | ||
410 | assert(t); | |
411 | ||
412 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
413 | ||
414 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
415 | if (next_server) |
416 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
417 | |
418 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
419 | if (r < 0) { |
420 | t->answer_errno = -r; | |
421 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
422 | } | |
8d10d620 LP |
423 | } |
424 | ||
c02cf2f4 | 425 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
426 | int r; |
427 | ||
c02cf2f4 LP |
428 | assert(t); |
429 | ||
5278bbfe LP |
430 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
431 | ||
c02cf2f4 LP |
432 | if (!t->server) |
433 | return 0; | |
434 | ||
435 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
436 | return 0; | |
437 | ||
438 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
439 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
440 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
441 | OPT RR or DO bit. One of these cases is documented here, for example: | |
442 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
443 | ||
4dd15077 LP |
444 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
445 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
446 | |
447 | r = dns_transaction_go(t); | |
448 | if (r < 0) | |
449 | return r; | |
450 | ||
451 | return 1; | |
c02cf2f4 LP |
452 | } |
453 | ||
98767d75 IT |
454 | static void on_transaction_stream_error(DnsTransaction *t, int error) { |
455 | assert(t); | |
ec2c5e43 | 456 | |
b30bf55d | 457 | dns_transaction_close_connection(t); |
ec2c5e43 | 458 | |
a1a3f73a | 459 | if (ERRNO_IS_DISCONNECT(error)) { |
0791110f LP |
460 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
461 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
462 | * question on this scope. */ | |
463 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
daab72ea | 464 | return; |
0791110f LP |
465 | } |
466 | ||
d001e0a3 | 467 | dns_transaction_retry(t, true); |
daab72ea | 468 | return; |
ac720200 | 469 | } |
ec2c5e43 | 470 | if (error != 0) { |
7cc6ed7b LP |
471 | t->answer_errno = error; |
472 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 | 473 | } |
98767d75 IT |
474 | } |
475 | ||
476 | static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsPacket *p) { | |
477 | assert(t); | |
478 | assert(p); | |
479 | ||
480 | dns_transaction_close_connection(t); | |
ec2c5e43 | 481 | |
a4076574 | 482 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 483 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
484 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
485 | return 0; | |
486 | } | |
487 | ||
488 | dns_scope_check_conflicts(t->scope, p); | |
489 | ||
ec2c5e43 LP |
490 | t->block_gc++; |
491 | dns_transaction_process_reply(t, p); | |
492 | t->block_gc--; | |
493 | ||
519ef046 LP |
494 | /* If the response wasn't useful, then complete the transition |
495 | * now. After all, we are the worst feature set now with TCP | |
496 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
497 | if (t->state == DNS_TRANSACTION_PENDING) |
498 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
499 | else |
500 | dns_transaction_gc(t); | |
ec2c5e43 LP |
501 | |
502 | return 0; | |
503 | } | |
504 | ||
98767d75 | 505 | static int on_stream_complete(DnsStream *s, int error) { |
18df5fb0 | 506 | _cleanup_(dns_stream_unrefp) DnsStream *p = NULL; |
98767d75 IT |
507 | |
508 | /* Do not let new transactions use this stream */ | |
509 | if (s->server && s->server->stream == s) | |
18df5fb0 | 510 | p = TAKE_PTR(s->server->stream); |
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 | ||
533 | static int dns_stream_on_packet(DnsStream *s) { | |
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 IT |
546 | |
547 | /* Ignore incorrect transaction id as transaction can have been canceled */ | |
aa337a5e LP |
548 | if (dns_packet_validate_reply(p) <= 0) { |
549 | log_debug("Invalid TCP reply packet."); | |
550 | on_stream_complete(s, 0); | |
98767d75 IT |
551 | } |
552 | ||
aa337a5e | 553 | return 0; |
98767d75 IT |
554 | } |
555 | ||
556 | static int dns_transaction_emit_tcp(DnsTransaction *t) { | |
ec2c5e43 | 557 | _cleanup_close_ int fd = -1; |
98767d75 | 558 | _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; |
91ccab1e | 559 | union sockaddr_union sa; |
ec2c5e43 LP |
560 | int r; |
561 | ||
562 | assert(t); | |
563 | ||
519ef046 | 564 | dns_transaction_close_connection(t); |
ec2c5e43 | 565 | |
106784eb | 566 | switch (t->scope->protocol) { |
519ef046 | 567 | |
106784eb | 568 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
569 | r = dns_transaction_pick_server(t); |
570 | if (r < 0) | |
571 | return r; | |
572 | ||
92ec902a | 573 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
574 | return -EOPNOTSUPP; |
575 | ||
274b8748 | 576 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
577 | if (r < 0) |
578 | return r; | |
579 | ||
5d67a7ae | 580 | if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted)) |
98767d75 IT |
581 | s = dns_stream_ref(t->server->stream); |
582 | else | |
5d67a7ae | 583 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53, &sa); |
98767d75 | 584 | |
106784eb | 585 | break; |
ec2c5e43 | 586 | |
106784eb | 587 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 588 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 589 | if (t->received) |
91ccab1e | 590 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa); |
ec2c5e43 LP |
591 | else { |
592 | union in_addr_union address; | |
a7f7d1bd | 593 | int family = AF_UNSPEC; |
ec2c5e43 LP |
594 | |
595 | /* Otherwise, try to talk to the owner of a | |
596 | * the IP address, in case this is a reverse | |
597 | * PTR lookup */ | |
f52e61da | 598 | |
1c02e7ba | 599 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
600 | if (r < 0) |
601 | return r; | |
602 | if (r == 0) | |
603 | return -EINVAL; | |
9e08a6e0 | 604 | if (family != t->scope->family) |
9318cdd3 | 605 | return -ESRCH; |
ec2c5e43 | 606 | |
91ccab1e | 607 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa); |
ec2c5e43 | 608 | } |
106784eb DM |
609 | |
610 | break; | |
611 | ||
612 | default: | |
ec2c5e43 | 613 | return -EAFNOSUPPORT; |
106784eb | 614 | } |
ec2c5e43 | 615 | |
98767d75 IT |
616 | if (!s) { |
617 | if (fd < 0) | |
618 | return fd; | |
ec2c5e43 | 619 | |
91ccab1e | 620 | r = dns_stream_new(t->scope->manager, &s, t->scope->protocol, fd, &sa); |
98767d75 IT |
621 | if (r < 0) |
622 | return r; | |
623 | ||
624 | fd = -1; | |
625 | ||
56ddbf10 | 626 | #if ENABLE_DNS_OVER_TLS |
5d67a7ae | 627 | if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) { |
b02a7e1a | 628 | assert(t->server); |
6016fcb0 | 629 | r = dnstls_stream_connect_tls(s, t->server); |
5d67a7ae IT |
630 | if (r < 0) |
631 | return r; | |
632 | } | |
633 | #endif | |
634 | ||
19feb28f IT |
635 | if (t->server) { |
636 | dns_stream_unref(t->server->stream); | |
637 | t->server->stream = dns_stream_ref(s); | |
638 | s->server = dns_server_ref(t->server); | |
639 | } | |
640 | ||
98767d75 IT |
641 | s->complete = on_stream_complete; |
642 | s->on_packet = dns_stream_on_packet; | |
643 | ||
644 | /* The interface index is difficult to determine if we are | |
645 | * connecting to the local host, hence fill this in right away | |
646 | * instead of determining it from the socket */ | |
647 | s->ifindex = dns_scope_ifindex(t->scope); | |
648 | } | |
649 | ||
650 | t->stream = TAKE_PTR(s); | |
651 | LIST_PREPEND(transactions_by_stream, t->stream->transactions, t); | |
ec2c5e43 LP |
652 | |
653 | r = dns_stream_write_packet(t->stream, t->sent); | |
654 | if (r < 0) { | |
98767d75 | 655 | dns_transaction_close_connection(t); |
ec2c5e43 LP |
656 | return r; |
657 | } | |
658 | ||
519ef046 LP |
659 | dns_transaction_reset_answer(t); |
660 | ||
cbe4216d LP |
661 | t->tried_stream = true; |
662 | ||
ec2c5e43 LP |
663 | return 0; |
664 | } | |
665 | ||
547973de | 666 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
667 | assert(t); |
668 | ||
669 | /* For mDNS we cache whenever we get the packet, rather than | |
670 | * in each transaction. */ | |
671 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
672 | return; | |
673 | ||
ceeddf79 MP |
674 | /* Caching disabled? */ |
675 | if (!t->scope->manager->enable_cache) | |
676 | return; | |
677 | ||
547973de LP |
678 | /* We never cache if this packet is from the local host, under |
679 | * the assumption that a locally running DNS server would | |
680 | * cache this anyway, and probably knows better when to flush | |
681 | * the cache then we could. */ | |
682 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
683 | return; | |
684 | ||
547973de LP |
685 | dns_cache_put(&t->scope->cache, |
686 | t->key, | |
687 | t->answer_rcode, | |
688 | t->answer, | |
547973de | 689 | t->answer_authenticated, |
d3760be0 | 690 | t->answer_nsec_ttl, |
547973de LP |
691 | 0, |
692 | t->received->family, | |
693 | &t->received->sender); | |
694 | } | |
695 | ||
105e1512 LP |
696 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
697 | DnsTransaction *dt; | |
698 | Iterator i; | |
699 | ||
700 | assert(t); | |
701 | ||
702 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
703 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
704 | return true; | |
705 | ||
706 | return false; | |
707 | } | |
708 | ||
942eb2e7 LP |
709 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
710 | DnsTransaction *dt; | |
711 | Iterator i; | |
712 | ||
713 | assert(t); | |
714 | ||
715 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
716 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
717 | ||
718 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
719 | ||
720 | switch (dt->state) { | |
721 | ||
722 | case DNS_TRANSACTION_NULL: | |
723 | case DNS_TRANSACTION_PENDING: | |
724 | case DNS_TRANSACTION_VALIDATING: | |
725 | /* Still ongoing */ | |
726 | return 0; | |
727 | ||
728 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 729 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
730 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
731 | goto fail; | |
732 | } | |
733 | ||
b3c6b00a LP |
734 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
735 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
736 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
737 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
738 | |
739 | case DNS_TRANSACTION_SUCCESS: | |
740 | /* All good. */ | |
741 | break; | |
742 | ||
743 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
744 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
745 | * validationr result */ | |
746 | ||
747 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
748 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
749 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
750 | return 0; | |
751 | ||
942eb2e7 LP |
752 | default: |
753 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
754 | goto fail; | |
755 | } | |
756 | } | |
757 | ||
758 | /* All is ready, we can go and validate */ | |
759 | return 1; | |
760 | ||
761 | fail: | |
762 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
763 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
764 | return 0; | |
765 | } | |
766 | ||
547973de LP |
767 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
768 | int r; | |
769 | ||
770 | assert(t); | |
771 | ||
772 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 773 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
774 | if (r < 0) |
775 | goto fail; | |
942eb2e7 | 776 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
777 | return; |
778 | ||
c02cf2f4 LP |
779 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
780 | * restart the lookup immediately. */ | |
781 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
782 | if (r < 0) |
783 | goto fail; | |
c02cf2f4 LP |
784 | if (r > 0) /* Transaction got restarted... */ |
785 | return; | |
786 | ||
547973de LP |
787 | /* All our auxiliary DNSSEC transactions are complete now. Try |
788 | * to validate our RRset now. */ | |
789 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
790 | if (r == -EBADMSG) { |
791 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
792 | return; | |
793 | } | |
7cc6ed7b LP |
794 | if (r < 0) |
795 | goto fail; | |
547973de | 796 | |
b652d4a2 LP |
797 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
798 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
799 | |
800 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
801 | * that works. */ | |
802 | ||
803 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { | |
804 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
805 | dns_transaction_retry(t, true); | |
806 | return; | |
807 | } | |
808 | ||
809 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
810 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
811 | return; | |
812 | } | |
813 | ||
019036a4 | 814 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
815 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
816 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
817 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
818 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
819 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
820 | return; | |
821 | } | |
822 | ||
1e02e182 LP |
823 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
824 | dns_server_warn_downgrade(t->server); | |
825 | ||
547973de LP |
826 | dns_transaction_cache_answer(t); |
827 | ||
828 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
829 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
830 | else | |
3bbdc31d | 831 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
832 | |
833 | return; | |
834 | ||
835 | fail: | |
836 | t->answer_errno = -r; | |
837 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
838 | } |
839 | ||
eac7cda2 LP |
840 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
841 | int r; | |
842 | ||
843 | assert(t); | |
844 | ||
845 | /* Checks whether the answer is positive, i.e. either a direct | |
846 | * answer to the question, or a CNAME/DNAME for it */ | |
847 | ||
848 | r = dns_answer_match_key(t->answer, t->key, flags); | |
849 | if (r != 0) | |
850 | return r; | |
851 | ||
852 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
853 | if (r != 0) | |
854 | return r; | |
855 | ||
856 | return false; | |
857 | } | |
858 | ||
859 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
860 | int r; | |
861 | ||
862 | assert(t); | |
863 | ||
864 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
865 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
866 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
867 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
868 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
869 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
870 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
871 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
872 | * incomplete CNAME/DNAME chain. | |
873 | * | |
874 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
875 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
876 | * lookup. */ | |
877 | ||
878 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
879 | return 0; | |
880 | ||
881 | r = dns_transaction_has_positive_answer(t, NULL); | |
882 | if (r <= 0) | |
883 | return r; | |
884 | ||
885 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
886 | return 0; | |
887 | } | |
888 | ||
ec2c5e43 | 889 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 890 | usec_t ts; |
ec2c5e43 LP |
891 | int r; |
892 | ||
893 | assert(t); | |
894 | assert(p); | |
9df3ba6c TG |
895 | assert(t->scope); |
896 | assert(t->scope->manager); | |
ec2c5e43 | 897 | |
5a7e41a3 LP |
898 | if (t->state != DNS_TRANSACTION_PENDING) |
899 | return; | |
900 | ||
ec2c5e43 LP |
901 | /* Note that this call might invalidate the query. Callers |
902 | * should hence not attempt to access the query or transaction | |
903 | * after calling this function. */ | |
904 | ||
11833205 ZJS |
905 | log_debug("Processing incoming packet on transaction %" PRIu16" (rcode=%s).", |
906 | t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); | |
b5efcf29 | 907 | |
106784eb | 908 | switch (t->scope->protocol) { |
b5efcf29 | 909 | |
106784eb | 910 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 911 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 912 | |
97ebebbc | 913 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
914 | return; |
915 | ||
916 | if (p->family != t->scope->family) | |
917 | return; | |
918 | ||
919 | /* Tentative packets are not full responses but still | |
920 | * useful for identifying uniqueness conflicts during | |
921 | * probing. */ | |
8b757a38 | 922 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
923 | dns_transaction_tentative(t, p); |
924 | return; | |
925 | } | |
106784eb DM |
926 | |
927 | break; | |
928 | ||
4e5bf5e1 | 929 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 930 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
931 | |
932 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
933 | return; |
934 | ||
935 | if (p->family != t->scope->family) | |
936 | return; | |
937 | ||
938 | break; | |
939 | ||
106784eb | 940 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
941 | /* Note that we do not need to verify the |
942 | * addresses/port numbers of incoming traffic, as we | |
943 | * invoked connect() on our UDP socket in which case | |
944 | * the kernel already does the needed verification for | |
945 | * us. */ | |
106784eb DM |
946 | break; |
947 | ||
948 | default: | |
9c56a6f3 | 949 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
950 | } |
951 | ||
ec2c5e43 LP |
952 | if (t->received != p) { |
953 | dns_packet_unref(t->received); | |
954 | t->received = dns_packet_ref(p); | |
955 | } | |
956 | ||
c3bc53e6 LP |
957 | t->answer_source = DNS_TRANSACTION_NETWORK; |
958 | ||
ec2c5e43 LP |
959 | if (p->ipproto == IPPROTO_TCP) { |
960 | if (DNS_PACKET_TC(p)) { | |
961 | /* Truncated via TCP? Somebody must be fucking with us */ | |
962 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
963 | return; | |
964 | } | |
965 | ||
966 | if (DNS_PACKET_ID(p) != t->id) { | |
967 | /* Not the reply to our query? Somebody must be fucking with us */ | |
968 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
969 | return; | |
970 | } | |
971 | } | |
972 | ||
38a03f06 | 973 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
974 | |
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: | |
1039 | dns_scope_packet_received(t->scope, ts - 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 | ||
8b419837 | 1111 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
b5efcf29 | 1112 | |
8b419837 DR |
1113 | /* When dealing with protocols other than mDNS only consider responses with |
1114 | * equivalent query section to the request. For mDNS this check doesn't make | |
1115 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1116 | * contain any questions in the Question Section". */ | |
1117 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1118 | r = dns_packet_is_reply_for(p, t->key); | |
1119 | if (r < 0) | |
1120 | goto fail; | |
1121 | if (r == 0) { | |
1122 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1123 | return; | |
1124 | } | |
547493c5 | 1125 | } |
29815b6c | 1126 | |
547493c5 DM |
1127 | /* Install the answer as answer to the transaction */ |
1128 | dns_answer_unref(t->answer); | |
1129 | t->answer = dns_answer_ref(p->answer); | |
1130 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1131 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1132 | t->answer_authenticated = false; |
79e24931 | 1133 | |
eac7cda2 LP |
1134 | r = dns_transaction_fix_rcode(t); |
1135 | if (r < 0) | |
1136 | goto fail; | |
1137 | ||
51e399bc LP |
1138 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1139 | t->block_gc++; | |
547973de | 1140 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1141 | t->block_gc--; |
1142 | ||
1143 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1144 | if (!dns_transaction_gc(t)) | |
1145 | return; | |
1146 | ||
1147 | /* Requesting additional keys might have resulted in | |
1148 | * this transaction to fail, since the auxiliary | |
1149 | * request failed for some reason. If so, we are not | |
1150 | * in pending state anymore, and we should exit | |
1151 | * quickly. */ | |
1152 | if (t->state != DNS_TRANSACTION_PENDING) | |
1153 | return; | |
7cc6ed7b LP |
1154 | if (r < 0) |
1155 | goto fail; | |
547973de LP |
1156 | if (r > 0) { |
1157 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1158 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1159 | dns_transaction_close_connection(t); |
1160 | dns_transaction_stop_timeout(t); | |
547973de LP |
1161 | return; |
1162 | } | |
547493c5 | 1163 | } |
ec2c5e43 | 1164 | |
547973de | 1165 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1166 | return; |
1167 | ||
1168 | fail: | |
1169 | t->answer_errno = -r; | |
1170 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1171 | } |
1172 | ||
c19ffd9f TG |
1173 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1174 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1175 | DnsTransaction *t = userdata; | |
1176 | int r; | |
1177 | ||
1178 | assert(t); | |
1179 | assert(t->scope); | |
1180 | ||
1181 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1182 | if (ERRNO_IS_DISCONNECT(-r)) { |
1183 | usec_t usec; | |
c19ffd9f | 1184 | |
7e1851e3 LP |
1185 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1186 | * recvmsg(). Treat this like a lost packet. */ | |
1187 | ||
92ec902a | 1188 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1189 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
3da3cdd5 | 1190 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level); |
7e1851e3 | 1191 | |
d001e0a3 | 1192 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1193 | return 0; |
1194 | } | |
1195 | if (r < 0) { | |
7cc6ed7b LP |
1196 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1197 | t->answer_errno = -r; | |
7e1851e3 LP |
1198 | return 0; |
1199 | } | |
1200 | ||
1201 | r = dns_packet_validate_reply(p); | |
1202 | if (r < 0) { | |
1203 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1204 | return 0; | |
1205 | } | |
1206 | if (r == 0) { | |
e09f605e | 1207 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1208 | return 0; |
1209 | } | |
1210 | ||
1211 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1212 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1213 | return 0; |
1214 | } | |
c19ffd9f | 1215 | |
7e1851e3 | 1216 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1217 | return 0; |
1218 | } | |
1219 | ||
49cce12d | 1220 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1221 | int r; |
1222 | ||
1223 | assert(t); | |
c19ffd9f | 1224 | |
519ef046 | 1225 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1226 | |
519ef046 | 1227 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1228 | if (r < 0) |
1229 | return r; | |
c19ffd9f | 1230 | |
5d67a7ae | 1231 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) |
7d581a65 | 1232 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1233 | |
92ec902a | 1234 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1235 | return -EOPNOTSUPP; |
1236 | ||
519ef046 LP |
1237 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1238 | int fd; | |
1239 | ||
1240 | dns_transaction_close_connection(t); | |
c19ffd9f | 1241 | |
519ef046 LP |
1242 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1243 | if (fd < 0) | |
1244 | return fd; | |
1245 | ||
1246 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1247 | if (r < 0) { | |
1248 | safe_close(fd); | |
1249 | return r; | |
1250 | } | |
1251 | ||
aa4a9deb | 1252 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1253 | t->dns_udp_fd = fd; |
1254 | } | |
1255 | ||
274b8748 | 1256 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1257 | if (r < 0) |
1258 | return r; | |
1259 | } else | |
1260 | dns_transaction_close_connection(t); | |
1261 | ||
1262 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1263 | if (r < 0) |
1264 | return r; | |
c19ffd9f | 1265 | |
519ef046 | 1266 | dns_transaction_reset_answer(t); |
be808ea0 | 1267 | |
471d40d9 | 1268 | return 0; |
c19ffd9f TG |
1269 | } |
1270 | ||
ec2c5e43 LP |
1271 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1272 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1273 | |
1274 | assert(s); | |
1275 | assert(t); | |
1276 | ||
ef7ce6df DM |
1277 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1278 | /* Timeout reached? Increase the timeout for the server used */ | |
1279 | switch (t->scope->protocol) { | |
49cce12d | 1280 | |
ef7ce6df DM |
1281 | case DNS_PROTOCOL_DNS: |
1282 | assert(t->server); | |
3da3cdd5 | 1283 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level); |
ef7ce6df | 1284 | break; |
49cce12d | 1285 | |
ef7ce6df DM |
1286 | case DNS_PROTOCOL_LLMNR: |
1287 | case DNS_PROTOCOL_MDNS: | |
1288 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1289 | break; |
49cce12d | 1290 | |
ef7ce6df DM |
1291 | default: |
1292 | assert_not_reached("Invalid DNS protocol."); | |
1293 | } | |
1294 | ||
1295 | if (t->initial_jitter_scheduled) | |
1296 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1297 | } |
1298 | ||
423659ab LP |
1299 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1300 | ||
d001e0a3 | 1301 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1302 | return 0; |
1303 | } | |
1304 | ||
9df3ba6c TG |
1305 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1306 | assert(t); | |
1307 | assert(t->scope); | |
1308 | ||
1309 | switch (t->scope->protocol) { | |
49cce12d | 1310 | |
9df3ba6c | 1311 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1312 | |
1313 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1314 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1315 | * needlessly. */ | |
1316 | if (t->stream) | |
1317 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1318 | ||
dbc4661a | 1319 | return DNS_TIMEOUT_USEC; |
49cce12d | 1320 | |
9df3ba6c | 1321 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1322 | assert(t->n_attempts > 0); |
53fda2bb DR |
1323 | if (t->probing) |
1324 | return MDNS_PROBING_INTERVAL_USEC; | |
1325 | else | |
1326 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1327 | |
11a27c2e | 1328 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1329 | return t->scope->resend_timeout; |
49cce12d | 1330 | |
9df3ba6c TG |
1331 | default: |
1332 | assert_not_reached("Invalid DNS protocol."); | |
1333 | } | |
1334 | } | |
1335 | ||
c842ff24 | 1336 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1337 | int r; |
1338 | ||
1339 | assert(t); | |
1340 | ||
f535705a | 1341 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1342 | |
86b112a3 | 1343 | if (!dns_scope_network_good(t->scope)) { |
edbcc1fd LP |
1344 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); |
1345 | return 0; | |
1346 | } | |
1347 | ||
ec2c5e43 LP |
1348 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1349 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1350 | return 0; | |
1351 | } | |
1352 | ||
cbe4216d | 1353 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1354 | /* If we already tried via a stream, then we don't |
1355 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1356 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | t->n_attempts++; | |
9df3ba6c | 1361 | t->start_usec = ts; |
c61d2b44 LP |
1362 | |
1363 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1364 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1365 | |
0d2cd476 LP |
1366 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1367 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1368 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1369 | if (r < 0) |
1370 | return r; | |
1371 | if (r > 0) { | |
1372 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1373 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1374 | t->answer_authenticated = true; |
0d2cd476 LP |
1375 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1376 | return 0; | |
1377 | } | |
b2b796b8 | 1378 | |
1c02e7ba | 1379 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1380 | t->key->type == DNS_TYPE_DS) { |
1381 | ||
1382 | /* Hmm, this is a request for the root DS? A | |
1383 | * DS RR doesn't exist in the root zone, and | |
1384 | * if our trust anchor didn't know it either, | |
1385 | * this means we cannot do any DNSSEC logic | |
1386 | * anymore. */ | |
1387 | ||
1ed8c0fb | 1388 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1389 | /* We are in downgrade mode. In this |
1390 | * case, synthesize an unsigned empty | |
1391 | * response, so that the any lookup | |
1392 | * depending on this one can continue | |
1393 | * assuming there was no DS, and hence | |
1394 | * the root zone was unsigned. */ | |
1395 | ||
1396 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1397 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1398 | t->answer_authenticated = false; | |
1399 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1400 | } else | |
1401 | /* If we are not in downgrade mode, | |
1402 | * then fail the lookup, because we | |
1403 | * cannot reasonably answer it. There | |
1404 | * might be DS RRs, but we don't know | |
1405 | * them, and the DNS server won't tell | |
1406 | * them to us (and even if it would, | |
202b76ae | 1407 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1408 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1409 | ||
1410 | return 0; | |
1411 | } | |
0d2cd476 LP |
1412 | } |
1413 | ||
1414 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1415 | * for probing or verifying a zone item. */ |
547973de | 1416 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1417 | |
97ebebbc | 1418 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1419 | if (r < 0) |
1420 | return r; | |
1421 | if (r > 0) { | |
ae6a4bbf | 1422 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1423 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1424 | t->answer_authenticated = true; |
d746bb3e LP |
1425 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1426 | return 0; | |
1427 | } | |
1428 | } | |
1429 | ||
4d926a69 LP |
1430 | /* Check the cache, but only if this transaction is not used |
1431 | * for probing or verifying a zone item. */ | |
547973de | 1432 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1433 | |
4d926a69 LP |
1434 | /* Before trying the cache, let's make sure we figured out a |
1435 | * server to use. Should this cause a change of server this | |
1436 | * might flush the cache. */ | |
5cdb8930 | 1437 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1438 | |
4d926a69 LP |
1439 | /* Let's then prune all outdated entries */ |
1440 | dns_cache_prune(&t->scope->cache); | |
1441 | ||
17c8de63 | 1442 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1443 | if (r < 0) |
1444 | return r; | |
1445 | if (r > 0) { | |
c3bc53e6 | 1446 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1447 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1448 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1449 | else | |
3bbdc31d | 1450 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1451 | return 0; |
1452 | } | |
ec2c5e43 LP |
1453 | } |
1454 | ||
1effe965 DM |
1455 | return 1; |
1456 | } | |
1457 | ||
0afa57e2 DM |
1458 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1459 | ||
1460 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1461 | bool add_known_answers = false; |
0afa57e2 | 1462 | DnsTransaction *other; |
0d5ee47d DR |
1463 | Iterator i; |
1464 | DnsResourceKey *tkey; | |
1465 | _cleanup_set_free_ Set *keys = NULL; | |
0afa57e2 | 1466 | unsigned qdcount; |
0d5ee47d | 1467 | unsigned nscount = 0; |
0afa57e2 DM |
1468 | usec_t ts; |
1469 | int r; | |
1470 | ||
1471 | assert(t); | |
1472 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1473 | ||
e5abebab | 1474 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1475 | t->sent = dns_packet_unref(t->sent); |
1476 | ||
1477 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1478 | if (r < 0) | |
1479 | return r; | |
1480 | ||
58ab31d5 | 1481 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1482 | if (r < 0) |
1483 | return r; | |
1484 | ||
1485 | qdcount = 1; | |
1486 | ||
7778dfff DM |
1487 | if (dns_key_is_shared(t->key)) |
1488 | add_known_answers = true; | |
1489 | ||
0d5ee47d DR |
1490 | if (t->key->type == DNS_TYPE_ANY) { |
1491 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1492 | if (r < 0) | |
1493 | return r; | |
1494 | ||
1495 | r = set_put(keys, t->key); | |
1496 | if (r < 0) | |
1497 | return r; | |
1498 | } | |
1499 | ||
0afa57e2 DM |
1500 | /* |
1501 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1502 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1503 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1504 | */ | |
1505 | ||
1506 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1507 | ||
1508 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1509 | ||
1510 | /* Skip ourselves */ | |
1511 | if (other == t) | |
1512 | continue; | |
1513 | ||
1514 | if (other->state != DNS_TRANSACTION_PENDING) | |
1515 | continue; | |
1516 | ||
1517 | if (other->next_attempt_after > ts) | |
1518 | continue; | |
1519 | ||
1520 | if (qdcount >= UINT16_MAX) | |
1521 | break; | |
1522 | ||
58ab31d5 | 1523 | r = dns_packet_append_key(p, other->key, 0, NULL); |
0afa57e2 DM |
1524 | |
1525 | /* | |
1526 | * If we can't stuff more questions into the packet, just give up. | |
1527 | * One of the 'other' transactions will fire later and take care of the rest. | |
1528 | */ | |
1529 | if (r == -EMSGSIZE) | |
1530 | break; | |
1531 | ||
1532 | if (r < 0) | |
1533 | return r; | |
1534 | ||
c842ff24 | 1535 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1536 | if (r <= 0) |
1537 | continue; | |
1538 | ||
1539 | ts += transaction_get_resend_timeout(other); | |
1540 | ||
1541 | r = sd_event_add_time( | |
1542 | other->scope->manager->event, | |
1543 | &other->timeout_event_source, | |
1544 | clock_boottime_or_monotonic(), | |
1545 | ts, 0, | |
1546 | on_transaction_timeout, other); | |
1547 | if (r < 0) | |
1548 | return r; | |
1549 | ||
ff537038 | 1550 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1551 | |
0afa57e2 DM |
1552 | other->state = DNS_TRANSACTION_PENDING; |
1553 | other->next_attempt_after = ts; | |
1554 | ||
313cefa1 | 1555 | qdcount++; |
7778dfff DM |
1556 | |
1557 | if (dns_key_is_shared(other->key)) | |
1558 | add_known_answers = true; | |
0d5ee47d DR |
1559 | |
1560 | if (other->key->type == DNS_TYPE_ANY) { | |
1561 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1562 | if (r < 0) | |
1563 | return r; | |
1564 | ||
1565 | r = set_put(keys, other->key); | |
1566 | if (r < 0) | |
1567 | return r; | |
1568 | } | |
0afa57e2 DM |
1569 | } |
1570 | ||
1571 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1572 | |
7778dfff DM |
1573 | /* Append known answer section if we're asking for any shared record */ |
1574 | if (add_known_answers) { | |
1575 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1576 | if (r < 0) | |
1577 | return r; | |
1578 | } | |
1579 | ||
0d5ee47d DR |
1580 | SET_FOREACH(tkey, keys, i) { |
1581 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
1582 | bool tentative; | |
1583 | ||
1584 | r = dns_zone_lookup(&t->scope->zone, tkey, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1585 | if (r < 0) | |
1586 | return r; | |
1587 | ||
1588 | r = dns_packet_append_answer(p, answer); | |
1589 | if (r < 0) | |
1590 | return r; | |
1591 | ||
1592 | nscount += dns_answer_size(answer); | |
1593 | } | |
1594 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1595 | ||
1cc6c93a | 1596 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1597 | |
1598 | return 0; | |
1599 | } | |
1600 | ||
1601 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1602 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1603 | int r; | |
1604 | ||
1605 | assert(t); | |
1606 | ||
1607 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1608 | return dns_transaction_make_packet_mdns(t); | |
1609 | ||
1610 | if (t->sent) | |
1611 | return 0; | |
1612 | ||
b652d4a2 | 1613 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1614 | if (r < 0) |
1615 | return r; | |
1616 | ||
58ab31d5 | 1617 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1618 | if (r < 0) |
1619 | return r; | |
1620 | ||
1621 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1622 | DNS_PACKET_HEADER(p)->id = t->id; | |
1623 | ||
1cc6c93a | 1624 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1625 | |
1626 | return 0; | |
1627 | } | |
1628 | ||
1effe965 DM |
1629 | int dns_transaction_go(DnsTransaction *t) { |
1630 | usec_t ts; | |
1631 | int r; | |
202b76ae | 1632 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1633 | |
1634 | assert(t); | |
1635 | ||
5278bbfe LP |
1636 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1637 | * now. */ | |
1638 | ||
1effe965 | 1639 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1640 | |
c842ff24 | 1641 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1642 | if (r <= 0) |
1643 | return r; | |
1644 | ||
202b76ae | 1645 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1646 | t->id, |
202b76ae | 1647 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1648 | dns_protocol_to_string(t->scope->protocol), |
1649 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1650 | af_to_name_short(t->scope->family)); |
1effe965 | 1651 | |
ef7ce6df | 1652 | if (!t->initial_jitter_scheduled && |
3742095b | 1653 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1654 | usec_t jitter, accuracy; |
6e068472 LP |
1655 | |
1656 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1657 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1658 | ||
ef7ce6df | 1659 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1660 | |
1661 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1662 | |
1663 | switch (t->scope->protocol) { | |
519ef046 | 1664 | |
ea12bcc7 DM |
1665 | case DNS_PROTOCOL_LLMNR: |
1666 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1667 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1668 | break; | |
519ef046 | 1669 | |
ea12bcc7 DM |
1670 | case DNS_PROTOCOL_MDNS: |
1671 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1672 | jitter += MDNS_JITTER_MIN_USEC; | |
1673 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1674 | break; | |
1675 | default: | |
1676 | assert_not_reached("bad protocol"); | |
1677 | } | |
6e068472 LP |
1678 | |
1679 | r = sd_event_add_time( | |
1680 | t->scope->manager->event, | |
1681 | &t->timeout_event_source, | |
1682 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1683 | ts + jitter, accuracy, |
6e068472 LP |
1684 | on_transaction_timeout, t); |
1685 | if (r < 0) | |
1686 | return r; | |
1687 | ||
aa4a9deb LP |
1688 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1689 | ||
6e068472 | 1690 | t->n_attempts = 0; |
a9da14e1 | 1691 | t->next_attempt_after = ts; |
6e068472 LP |
1692 | t->state = DNS_TRANSACTION_PENDING; |
1693 | ||
ea12bcc7 | 1694 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1695 | return 0; |
1696 | } | |
1697 | ||
ec2c5e43 LP |
1698 | /* Otherwise, we need to ask the network */ |
1699 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1700 | if (r < 0) |
1701 | return r; | |
1702 | ||
1703 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1704 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1705 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1706 | |
1707 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1708 | * always be made via TCP on LLMNR */ | |
98767d75 | 1709 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1710 | } else { |
be808ea0 TG |
1711 | /* Try via UDP, and if that fails due to large size or lack of |
1712 | * support try via TCP */ | |
49cce12d | 1713 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1714 | if (r == -EMSGSIZE) |
1715 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1716 | else if (r == -EAGAIN) |
5d67a7ae | 1717 | log_debug("Sending query via TCP since UDP isn't supported."); |
4c701096 | 1718 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
98767d75 | 1719 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1720 | } |
be808ea0 | 1721 | |
ec2c5e43 LP |
1722 | if (r == -ESRCH) { |
1723 | /* No servers to send this to? */ | |
1724 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1725 | return 0; | |
91adc4db LP |
1726 | } |
1727 | if (r == -EOPNOTSUPP) { | |
1728 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1729 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1730 | return 0; | |
1731 | } | |
0791110f | 1732 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1733 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1734 | * answer this request with this protocol. */ |
1735 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1736 | return 0; | |
1737 | } | |
91adc4db | 1738 | if (r < 0) { |
7cc6ed7b LP |
1739 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1740 | return r; | |
13b551ac | 1741 | |
ec2c5e43 | 1742 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1743 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1744 | |
1745 | return dns_transaction_go(t); | |
1746 | } | |
1747 | ||
a9da14e1 DM |
1748 | ts += transaction_get_resend_timeout(t); |
1749 | ||
9a015429 LP |
1750 | r = sd_event_add_time( |
1751 | t->scope->manager->event, | |
1752 | &t->timeout_event_source, | |
1753 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1754 | ts, 0, |
9a015429 | 1755 | on_transaction_timeout, t); |
ec2c5e43 LP |
1756 | if (r < 0) |
1757 | return r; | |
1758 | ||
aa4a9deb LP |
1759 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1760 | ||
ec2c5e43 | 1761 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1762 | t->next_attempt_after = ts; |
1763 | ||
ec2c5e43 LP |
1764 | return 1; |
1765 | } | |
1766 | ||
f2992dc1 LP |
1767 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1768 | DnsTransaction *n; | |
1769 | Iterator i; | |
1770 | int r; | |
1771 | ||
1772 | assert(t); | |
1773 | assert(aux); | |
1774 | ||
1775 | /* Try to find cyclic dependencies between transaction objects */ | |
1776 | ||
1777 | if (t == aux) | |
1778 | return 1; | |
1779 | ||
3eb6aa00 | 1780 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1781 | r = dns_transaction_find_cyclic(t, n); |
1782 | if (r != 0) | |
1783 | return r; | |
1784 | } | |
1785 | ||
3eb6aa00 | 1786 | return 0; |
f2992dc1 LP |
1787 | } |
1788 | ||
547973de LP |
1789 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1790 | DnsTransaction *aux; | |
1791 | int r; | |
1792 | ||
1793 | assert(t); | |
1794 | assert(ret); | |
1795 | assert(key); | |
1796 | ||
1797 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1798 | if (!aux) { | |
1799 | r = dns_transaction_new(&aux, t->scope, key); | |
1800 | if (r < 0) | |
1801 | return r; | |
1802 | } else { | |
1803 | if (set_contains(t->dnssec_transactions, aux)) { | |
1804 | *ret = aux; | |
1805 | return 0; | |
1806 | } | |
f2992dc1 LP |
1807 | |
1808 | r = dns_transaction_find_cyclic(t, aux); | |
1809 | if (r < 0) | |
1810 | return r; | |
1811 | if (r > 0) { | |
202b76ae ZJS |
1812 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1813 | ||
baaa35ad ZJS |
1814 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), |
1815 | "Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1816 | aux->id, | |
1817 | dns_resource_key_to_string(t->key, s, sizeof s), | |
1818 | t->id, | |
1819 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); | |
f2992dc1 | 1820 | } |
547973de LP |
1821 | } |
1822 | ||
1823 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1824 | if (r < 0) | |
1825 | goto gc; | |
1826 | ||
1827 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1828 | if (r < 0) | |
35aa04e9 LP |
1829 | goto gc; |
1830 | ||
1831 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1832 | if (r < 0) | |
547973de LP |
1833 | goto gc; |
1834 | ||
1835 | r = set_put(t->dnssec_transactions, aux); | |
1836 | if (r < 0) | |
1837 | goto gc; | |
1838 | ||
1839 | r = set_put(aux->notify_transactions, t); | |
1840 | if (r < 0) { | |
1841 | (void) set_remove(t->dnssec_transactions, aux); | |
1842 | goto gc; | |
1843 | } | |
1844 | ||
1845 | *ret = aux; | |
1846 | return 1; | |
1847 | ||
1848 | gc: | |
1849 | dns_transaction_gc(aux); | |
1850 | return r; | |
1851 | } | |
1852 | ||
1853 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1854 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1855 | DnsTransaction *aux; | |
1856 | int r; | |
1857 | ||
1858 | assert(t); | |
1859 | assert(key); | |
1860 | ||
1861 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1862 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1863 | if (r < 0) |
1864 | return r; | |
1865 | if (r > 0) { | |
1866 | r = dns_answer_extend(&t->validated_keys, a); | |
1867 | if (r < 0) | |
1868 | return r; | |
1869 | ||
1870 | return 0; | |
1871 | } | |
1872 | ||
1873 | /* This didn't work, ask for it via the network/cache then. */ | |
1874 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1875 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1876 | return 0; | |
547973de LP |
1877 | if (r < 0) |
1878 | return r; | |
1879 | ||
1880 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1881 | r = dns_transaction_go(aux); | |
1882 | if (r < 0) | |
1883 | return r; | |
1884 | } | |
1885 | ||
f2992dc1 | 1886 | return 1; |
547973de LP |
1887 | } |
1888 | ||
8a516214 LP |
1889 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1890 | int r; | |
1891 | ||
1892 | assert(t); | |
1893 | ||
c629ff58 | 1894 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1895 | * database, either in the global one, or the link-local |
1896 | * one. */ | |
1897 | ||
1898 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1899 | if (r != 0) | |
1900 | return r; | |
1901 | ||
1902 | if (!t->scope->link) | |
1903 | return 0; | |
1904 | ||
1905 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1906 | } | |
1907 | ||
105e1512 LP |
1908 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1909 | int r; | |
1910 | ||
1911 | assert(t); | |
1912 | ||
1913 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1914 | * RRs to prove it */ | |
1915 | ||
1916 | r = dns_transaction_has_positive_answer(t, NULL); | |
1917 | if (r < 0) | |
1918 | return r; | |
1919 | if (r > 0) | |
1920 | return false; | |
1921 | ||
8e54f5d9 LP |
1922 | /* Is this key explicitly listed as a negative trust anchor? |
1923 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1924 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1925 | if (r < 0) |
1926 | return r; | |
1927 | if (r > 0) | |
1928 | return false; | |
1929 | ||
105e1512 LP |
1930 | /* The answer does not contain any RRs that match to the |
1931 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1932 | * included. If not, the answer is unsigned. */ | |
1933 | ||
1934 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1935 | if (r < 0) | |
1936 | return r; | |
1937 | if (r > 0) | |
1938 | return false; | |
1939 | ||
1940 | return true; | |
1941 | } | |
1942 | ||
1943 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1944 | int r; | |
1945 | ||
1946 | assert(t); | |
1947 | assert(rr); | |
1948 | ||
1949 | /* Check if the specified RR is the "primary" response, | |
1950 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1951 | * CNAME/DNAME for it. */ |
105e1512 LP |
1952 | |
1953 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1954 | if (r != 0) | |
1955 | return r; | |
1956 | ||
4cb94977 | 1957 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1958 | } |
1959 | ||
92ec902a LP |
1960 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1961 | assert(t); | |
1962 | ||
1963 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1964 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1965 | ||
1966 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1967 | return false; | |
1968 | ||
1969 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1970 | * be supported, hence return true. */ | |
1971 | if (!t->server) | |
1972 | return true; | |
1973 | ||
d001e0a3 LP |
1974 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1975 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1976 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1977 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1978 | |
1979 | return dns_server_dnssec_supported(t->server); | |
1980 | } | |
1981 | ||
1982 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1983 | DnsTransaction *dt; | |
1984 | Iterator i; | |
1985 | ||
1986 | assert(t); | |
1987 | ||
1988 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1989 | ||
1990 | if (!dns_transaction_dnssec_supported(t)) | |
1991 | return false; | |
1992 | ||
1993 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1994 | if (!dns_transaction_dnssec_supported(dt)) | |
1995 | return false; | |
1996 | ||
1997 | return true; | |
1998 | } | |
1999 | ||
547973de LP |
2000 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
2001 | DnsResourceRecord *rr; | |
105e1512 | 2002 | |
547973de LP |
2003 | int r; |
2004 | ||
2005 | assert(t); | |
2006 | ||
105e1512 LP |
2007 | /* |
2008 | * Retrieve all auxiliary RRs for the answer we got, so that | |
2009 | * we can verify signatures or prove that RRs are rightfully | |
2010 | * unsigned. Specifically: | |
2011 | * | |
2012 | * - For RRSIG we get the matching DNSKEY | |
2013 | * - For DNSKEY we get the matching DS | |
2014 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 2015 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 2016 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
2017 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
2018 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
2019 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
2020 | */ | |
2021 | ||
b652d4a2 | 2022 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 2023 | return 0; |
92ec902a LP |
2024 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
2025 | return 0; /* We only need to validate stuff from the network */ | |
2026 | if (!dns_transaction_dnssec_supported(t)) | |
2027 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 2028 | |
547973de LP |
2029 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2030 | ||
105e1512 LP |
2031 | if (dns_type_is_pseudo(rr->key->type)) |
2032 | continue; | |
2033 | ||
8e54f5d9 | 2034 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 2035 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2036 | if (r < 0) |
2037 | return r; | |
2038 | if (r > 0) | |
2039 | continue; | |
2040 | ||
547973de LP |
2041 | switch (rr->key->type) { |
2042 | ||
2043 | case DNS_TYPE_RRSIG: { | |
2044 | /* For each RRSIG we request the matching DNSKEY */ | |
2045 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
2046 | ||
2047 | /* If this RRSIG is about a DNSKEY RR and the | |
2048 | * signer is the same as the owner, then we | |
2049 | * already have the DNSKEY, and we don't have | |
2050 | * to look for more. */ | |
2051 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 2052 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
2053 | if (r < 0) |
2054 | return r; | |
2055 | if (r > 0) | |
2056 | continue; | |
2057 | } | |
2058 | ||
105e1512 LP |
2059 | /* If the signer is not a parent of our |
2060 | * original query, then this is about an | |
2061 | * auxiliary RRset, but not anything we asked | |
2062 | * for. In this case we aren't interested, | |
2063 | * because we don't want to request additional | |
2064 | * RRs for stuff we didn't really ask for, and | |
2065 | * also to avoid request loops, where | |
2066 | * additional RRs from one transaction result | |
2067 | * in another transaction whose additonal RRs | |
2068 | * point back to the original transaction, and | |
2069 | * we deadlock. */ | |
1c02e7ba | 2070 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
2071 | if (r < 0) |
2072 | return r; | |
2073 | if (r == 0) | |
2074 | continue; | |
2075 | ||
2076 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2077 | if (!dnskey) | |
2078 | return -ENOMEM; | |
2079 | ||
1c02e7ba ZJS |
2080 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2081 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2082 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2083 | if (r < 0) | |
2084 | return r; | |
2085 | break; | |
2086 | } | |
2087 | ||
2088 | case DNS_TYPE_DNSKEY: { | |
2089 | /* For each DNSKEY we request the matching DS */ | |
2090 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2091 | ||
105e1512 LP |
2092 | /* If the DNSKEY we are looking at is not for |
2093 | * zone we are interested in, nor any of its | |
2094 | * parents, we aren't interested, and don't | |
2095 | * request it. After all, we don't want to end | |
2096 | * up in request loops, and want to keep | |
2097 | * additional traffic down. */ | |
2098 | ||
1c02e7ba | 2099 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2100 | if (r < 0) |
2101 | return r; | |
2102 | if (r == 0) | |
2103 | continue; | |
2104 | ||
1c02e7ba | 2105 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2106 | if (!ds) |
2107 | return -ENOMEM; | |
2108 | ||
1c02e7ba ZJS |
2109 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2110 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2111 | r = dns_transaction_request_dnssec_rr(t, ds); |
2112 | if (r < 0) | |
2113 | return r; | |
547973de | 2114 | |
105e1512 LP |
2115 | break; |
2116 | } | |
2117 | ||
105e1512 LP |
2118 | case DNS_TYPE_SOA: |
2119 | case DNS_TYPE_NS: { | |
2120 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2121 | ||
2122 | /* For an unsigned SOA or NS, try to acquire | |
2123 | * the matching DS RR, as we are at a zone cut | |
2124 | * then, and whether a DS exists tells us | |
2125 | * whether the zone is signed. Do so only if | |
2126 | * this RR matches our original question, | |
2127 | * however. */ | |
2128 | ||
2129 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
2130 | if (r < 0) | |
2131 | return r; | |
6993d264 LP |
2132 | if (r == 0) { |
2133 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
2134 | * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry? | |
2135 | * If so, we need to validate it, too. */ | |
2136 | ||
2137 | r = dns_answer_match_key(t->answer, t->key, NULL); | |
2138 | if (r < 0) | |
2139 | return r; | |
2140 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2141 | * it. */ | |
2142 | continue; | |
2143 | } | |
105e1512 LP |
2144 | |
2145 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2146 | if (r < 0) | |
2147 | return r; | |
2148 | if (r > 0) | |
2149 | continue; | |
2150 | ||
1c02e7ba | 2151 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2152 | if (!ds) |
2153 | return -ENOMEM; | |
2154 | ||
1c02e7ba ZJS |
2155 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2156 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2157 | r = dns_transaction_request_dnssec_rr(t, ds); |
2158 | if (r < 0) | |
2159 | return r; | |
2160 | ||
2161 | break; | |
105e1512 LP |
2162 | } |
2163 | ||
b63fca62 | 2164 | case DNS_TYPE_DS: |
105e1512 LP |
2165 | case DNS_TYPE_CNAME: |
2166 | case DNS_TYPE_DNAME: { | |
2167 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2168 | const char *name; | |
2169 | ||
2170 | /* CNAMEs and DNAMEs cannot be located at a | |
2171 | * zone apex, hence ask for the parent SOA for | |
2172 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2173 | * apex. But do all that only if this is | |
2174 | * actually a response to our original | |
b63fca62 LP |
2175 | * question. |
2176 | * | |
2177 | * Similar for DS RRs, which are signed when | |
2178 | * the parent SOA is signed. */ | |
105e1512 LP |
2179 | |
2180 | r = dns_transaction_is_primary_response(t, rr); | |
2181 | if (r < 0) | |
2182 | return r; | |
2183 | if (r == 0) | |
2184 | continue; | |
2185 | ||
2186 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2187 | if (r < 0) | |
2188 | return r; | |
2189 | if (r > 0) | |
2190 | continue; | |
2191 | ||
43e6779a LP |
2192 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2193 | if (r < 0) | |
2194 | return r; | |
2195 | if (r > 0) | |
2196 | continue; | |
2197 | ||
1c02e7ba | 2198 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2199 | r = dns_name_parent(&name); |
2200 | if (r < 0) | |
2201 | return r; | |
2202 | if (r == 0) | |
2203 | continue; | |
2204 | ||
2205 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2206 | if (!soa) | |
2207 | return -ENOMEM; | |
2208 | ||
1c02e7ba ZJS |
2209 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2210 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2211 | r = dns_transaction_request_dnssec_rr(t, soa); |
2212 | if (r < 0) | |
2213 | return r; | |
2214 | ||
2215 | break; | |
2216 | } | |
2217 | ||
2218 | default: { | |
2219 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2220 | ||
b63fca62 LP |
2221 | /* For other unsigned RRsets (including |
2222 | * NSEC/NSEC3!), look for proof the zone is | |
2223 | * unsigned, by requesting the SOA RR of the | |
2224 | * zone. However, do so only if they are | |
2225 | * directly relevant to our original | |
105e1512 LP |
2226 | * question. */ |
2227 | ||
2228 | r = dns_transaction_is_primary_response(t, rr); | |
2229 | if (r < 0) | |
2230 | return r; | |
2231 | if (r == 0) | |
2232 | continue; | |
2233 | ||
2234 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2235 | if (r < 0) | |
2236 | return r; | |
2237 | if (r > 0) | |
2238 | continue; | |
2239 | ||
1c02e7ba | 2240 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2241 | if (!soa) |
2242 | return -ENOMEM; | |
2243 | ||
1c02e7ba ZJS |
2244 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2245 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2246 | r = dns_transaction_request_dnssec_rr(t, soa); |
2247 | if (r < 0) | |
2248 | return r; | |
2249 | break; | |
547973de LP |
2250 | }} |
2251 | } | |
2252 | ||
105e1512 LP |
2253 | /* Above, we requested everything necessary to validate what |
2254 | * we got. Now, let's request what we need to validate what we | |
2255 | * didn't get... */ | |
2256 | ||
2257 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2258 | if (r < 0) | |
2259 | return r; | |
2260 | if (r > 0) { | |
2261 | const char *name; | |
4bbc06cc | 2262 | uint16_t type = 0; |
105e1512 | 2263 | |
1c02e7ba | 2264 | name = dns_resource_key_name(t->key); |
105e1512 | 2265 | |
4bbc06cc LP |
2266 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2267 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2268 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2269 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2270 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2271 | * to see if that is signed. */ | |
105e1512 | 2272 | |
4bbc06cc | 2273 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2274 | r = dns_name_parent(&name); |
4bbc06cc LP |
2275 | if (r > 0) { |
2276 | type = DNS_TYPE_SOA; | |
2277 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2278 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2279 | } else |
105e1512 | 2280 | name = NULL; |
4bbc06cc LP |
2281 | |
2282 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2283 | ||
2284 | type = DNS_TYPE_DS; | |
2285 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2286 | t->id, dns_resource_key_name(t->key)); | |
2287 | ||
2288 | } else { | |
2289 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2290 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2291 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2292 | } |
105e1512 LP |
2293 | |
2294 | if (name) { | |
2295 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2296 | ||
4bbc06cc | 2297 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2298 | if (!soa) |
2299 | return -ENOMEM; | |
2300 | ||
2301 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2302 | if (r < 0) | |
2303 | return r; | |
2304 | } | |
2305 | } | |
2306 | ||
2307 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2308 | } |
2309 | ||
2310 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2311 | assert(t); |
547973de LP |
2312 | assert(source); |
2313 | ||
942eb2e7 LP |
2314 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2315 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2316 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2317 | |
942eb2e7 LP |
2318 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2319 | dns_transaction_process_dnssec(t); | |
547973de LP |
2320 | } |
2321 | ||
105e1512 LP |
2322 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2323 | DnsResourceRecord *rr; | |
2324 | int ifindex, r; | |
2325 | ||
2326 | assert(t); | |
2327 | ||
2328 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2329 | * RRs from the list of validated keys to the list of | |
2330 | * validated keys. */ | |
2331 | ||
2332 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2333 | ||
96bb7673 | 2334 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2335 | if (r < 0) |
2336 | return r; | |
2337 | if (r == 0) | |
2338 | continue; | |
2339 | ||
2340 | /* If so, the DNSKEY is validated too. */ | |
2341 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2342 | if (r < 0) | |
2343 | return r; | |
2344 | } | |
2345 | ||
2346 | return 0; | |
2347 | } | |
2348 | ||
2349 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2350 | int r; |
2351 | ||
2352 | assert(t); | |
2353 | assert(rr); | |
2354 | ||
105e1512 LP |
2355 | /* Checks if the RR we are looking for must be signed with an |
2356 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2357 | |
b652d4a2 | 2358 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2359 | return false; |
56352fe9 | 2360 | |
105e1512 LP |
2361 | if (dns_type_is_pseudo(rr->key->type)) |
2362 | return -EINVAL; | |
56352fe9 | 2363 | |
1c02e7ba | 2364 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2365 | if (r < 0) |
2366 | return r; | |
2367 | if (r > 0) | |
2368 | return false; | |
2369 | ||
105e1512 | 2370 | switch (rr->key->type) { |
56352fe9 | 2371 | |
105e1512 LP |
2372 | case DNS_TYPE_RRSIG: |
2373 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2374 | return false; | |
2375 | ||
2376 | case DNS_TYPE_SOA: | |
2377 | case DNS_TYPE_NS: { | |
2378 | DnsTransaction *dt; | |
2379 | Iterator i; | |
2380 | ||
b63fca62 | 2381 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2382 | |
2383 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2384 | ||
2385 | if (dt->key->class != rr->key->class) | |
2386 | continue; | |
2387 | if (dt->key->type != DNS_TYPE_DS) | |
2388 | continue; | |
2389 | ||
1c02e7ba | 2390 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2391 | if (r < 0) |
2392 | return r; | |
2393 | if (r == 0) | |
2394 | continue; | |
2395 | ||
2396 | /* We found a DS transactions for the SOA/NS | |
2397 | * RRs we are looking at. If it discovered signed DS | |
2398 | * RRs, then we need to be signed, too. */ | |
2399 | ||
097a2517 TA |
2400 | if (!dt->answer_authenticated) |
2401 | return false; | |
105e1512 | 2402 | |
097a2517 | 2403 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2404 | } |
2405 | ||
2406 | /* We found nothing that proves this is safe to leave | |
2407 | * this unauthenticated, hence ask inist on | |
2408 | * authentication. */ | |
2409 | return true; | |
2410 | } | |
2411 | ||
b63fca62 | 2412 | case DNS_TYPE_DS: |
105e1512 LP |
2413 | case DNS_TYPE_CNAME: |
2414 | case DNS_TYPE_DNAME: { | |
2415 | const char *parent = NULL; | |
2416 | DnsTransaction *dt; | |
2417 | Iterator i; | |
2418 | ||
b63fca62 LP |
2419 | /* |
2420 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2421 | * | |
2422 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2423 | */ | |
105e1512 LP |
2424 | |
2425 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2426 | ||
2427 | if (dt->key->class != rr->key->class) | |
2428 | continue; | |
2429 | if (dt->key->type != DNS_TYPE_SOA) | |
2430 | continue; | |
2431 | ||
2432 | if (!parent) { | |
1c02e7ba | 2433 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2434 | r = dns_name_parent(&parent); |
2435 | if (r < 0) | |
2436 | return r; | |
2437 | if (r == 0) { | |
b63fca62 LP |
2438 | if (rr->key->type == DNS_TYPE_DS) |
2439 | return true; | |
2440 | ||
105e1512 | 2441 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
baaa35ad ZJS |
2442 | return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), |
2443 | "Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
105e1512 LP |
2444 | } |
2445 | } | |
2446 | ||
1c02e7ba | 2447 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2448 | if (r < 0) |
2449 | return r; | |
2450 | if (r == 0) | |
2451 | continue; | |
2452 | ||
2453 | return t->answer_authenticated; | |
2454 | } | |
2455 | ||
2456 | return true; | |
2457 | } | |
2458 | ||
2459 | default: { | |
2460 | DnsTransaction *dt; | |
2461 | Iterator i; | |
2462 | ||
b63fca62 | 2463 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2464 | |
2465 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2466 | ||
2467 | if (dt->key->class != rr->key->class) | |
2468 | continue; | |
2469 | if (dt->key->type != DNS_TYPE_SOA) | |
2470 | continue; | |
2471 | ||
1c02e7ba | 2472 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2473 | if (r < 0) |
2474 | return r; | |
2475 | if (r == 0) | |
2476 | continue; | |
2477 | ||
2478 | /* We found the transaction that was supposed to find | |
2479 | * the SOA RR for us. It was successful, but found no | |
2480 | * RR for us. This means we are not at a zone cut. In | |
2481 | * this case, we require authentication if the SOA | |
2482 | * lookup was authenticated too. */ | |
2483 | return t->answer_authenticated; | |
2484 | } | |
2485 | ||
2486 | return true; | |
2487 | }} | |
56352fe9 LP |
2488 | } |
2489 | ||
d33b6cf3 LP |
2490 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2491 | DnsTransaction *dt; | |
2492 | const char *tld; | |
2493 | Iterator i; | |
2494 | int r; | |
2495 | ||
2496 | /* If DNSSEC downgrade mode is on, checks whether the | |
2497 | * specified RR is one level below a TLD we have proven not to | |
2498 | * exist. In such a case we assume that this is a private | |
2499 | * domain, and permit it. | |
2500 | * | |
2501 | * This detects cases like the Fritz!Box router networks. Each | |
2502 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2503 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2504 | * are served by the router itself, while requests for the | |
2505 | * "box" domain will result in NXDOMAIN. | |
2506 | * | |
2507 | * Note that this logic is unable to detect cases where a | |
2508 | * router serves a private DNS zone directly under | |
2509 | * non-existing TLD. In such a case we cannot detect whether | |
2510 | * the TLD is supposed to exist or not, as all requests we | |
2511 | * make for it will be answered by the router's zone, and not | |
2512 | * by the root zone. */ | |
2513 | ||
2514 | assert(t); | |
2515 | ||
2516 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2517 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2518 | ||
1c02e7ba | 2519 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2520 | r = dns_name_parent(&tld); |
2521 | if (r < 0) | |
2522 | return r; | |
2523 | if (r == 0) | |
2524 | return false; /* Already the root domain */ | |
2525 | ||
2526 | if (!dns_name_is_single_label(tld)) | |
2527 | return false; | |
2528 | ||
2529 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2530 | ||
2531 | if (dt->key->class != key->class) | |
2532 | continue; | |
2533 | ||
1c02e7ba | 2534 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2535 | if (r < 0) |
2536 | return r; | |
2537 | if (r == 0) | |
2538 | continue; | |
2539 | ||
2540 | /* We found an auxiliary lookup we did for the TLD. If | |
2541 | * that returned with NXDOMAIN, we know the TLD didn't | |
2542 | * exist, and hence this might be a private zone. */ | |
2543 | ||
2544 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2545 | } | |
2546 | ||
2547 | return false; | |
2548 | } | |
2549 | ||
105e1512 | 2550 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2551 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2552 | DnsTransaction *dt; |
2553 | const char *name; | |
4bbc06cc | 2554 | uint16_t type = 0; |
105e1512 LP |
2555 | Iterator i; |
2556 | int r; | |
56352fe9 LP |
2557 | |
2558 | assert(t); | |
2559 | ||
105e1512 LP |
2560 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2561 | * this negative reply */ | |
56352fe9 | 2562 | |
b652d4a2 | 2563 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2564 | return false; |
56352fe9 | 2565 | |
105e1512 LP |
2566 | if (dns_type_is_pseudo(t->key->type)) |
2567 | return -EINVAL; | |
2568 | ||
1c02e7ba | 2569 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2570 | if (r < 0) |
2571 | return r; | |
2572 | if (r > 0) | |
2573 | return false; | |
2574 | ||
d33b6cf3 LP |
2575 | r = dns_transaction_in_private_tld(t, t->key); |
2576 | if (r < 0) | |
2577 | return r; | |
2578 | if (r > 0) { | |
2579 | /* The lookup is from a TLD that is proven not to | |
2580 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2581 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2582 | |
202b76ae ZJS |
2583 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2584 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2585 | return false; |
2586 | } | |
2587 | ||
1c02e7ba | 2588 | name = dns_resource_key_name(t->key); |
105e1512 | 2589 | |
4bbc06cc | 2590 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2591 | |
4bbc06cc LP |
2592 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2593 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2594 | |
2595 | r = dns_name_parent(&name); | |
56352fe9 LP |
2596 | if (r < 0) |
2597 | return r; | |
2598 | if (r == 0) | |
105e1512 | 2599 | return true; |
4bbc06cc LP |
2600 | |
2601 | type = DNS_TYPE_SOA; | |
2602 | ||
2603 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2604 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2605 | type = DNS_TYPE_DS; | |
2606 | else | |
2607 | /* For all other negative replies, check for the SOA lookup */ | |
2608 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2609 | |
2610 | /* For all other RRs we check the SOA on the same level to see | |
2611 | * if it's signed. */ | |
2612 | ||
2613 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2614 | ||
2615 | if (dt->key->class != t->key->class) | |
2616 | continue; | |
4bbc06cc | 2617 | if (dt->key->type != type) |
56352fe9 LP |
2618 | continue; |
2619 | ||
1c02e7ba | 2620 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2621 | if (r < 0) |
2622 | return r; | |
105e1512 LP |
2623 | if (r == 0) |
2624 | continue; | |
2625 | ||
2626 | return dt->answer_authenticated; | |
56352fe9 LP |
2627 | } |
2628 | ||
105e1512 LP |
2629 | /* If in doubt, require NSEC/NSEC3 */ |
2630 | return true; | |
56352fe9 LP |
2631 | } |
2632 | ||
94aa7071 LP |
2633 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2634 | DnsResourceRecord *rrsig; | |
2635 | bool found = false; | |
2636 | int r; | |
2637 | ||
2638 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2639 | * the specified RRset is authenticated (i.e. has a matching | |
2640 | * DS RR). */ | |
2641 | ||
1c02e7ba | 2642 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2643 | if (r < 0) |
2644 | return r; | |
2645 | if (r > 0) | |
2646 | return false; | |
2647 | ||
94aa7071 LP |
2648 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2649 | DnsTransaction *dt; | |
2650 | Iterator i; | |
2651 | ||
2652 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2653 | if (r < 0) | |
2654 | return r; | |
2655 | if (r == 0) | |
2656 | continue; | |
2657 | ||
2658 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2659 | ||
2660 | if (dt->key->class != rr->key->class) | |
2661 | continue; | |
2662 | ||
2663 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2664 | ||
1c02e7ba | 2665 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2666 | if (r < 0) |
2667 | return r; | |
2668 | if (r == 0) | |
2669 | continue; | |
2670 | ||
2671 | /* OK, we found an auxiliary DNSKEY | |
2672 | * lookup. If that lookup is | |
2673 | * authenticated, report this. */ | |
2674 | ||
2675 | if (dt->answer_authenticated) | |
2676 | return true; | |
2677 | ||
2678 | found = true; | |
2679 | ||
2680 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2681 | ||
1c02e7ba | 2682 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2683 | if (r < 0) |
2684 | return r; | |
2685 | if (r == 0) | |
2686 | continue; | |
2687 | ||
2688 | /* OK, we found an auxiliary DS | |
2689 | * lookup. If that lookup is | |
2690 | * authenticated and non-zero, we | |
2691 | * won! */ | |
2692 | ||
2693 | if (!dt->answer_authenticated) | |
2694 | return false; | |
2695 | ||
2696 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2697 | } | |
2698 | } | |
2699 | } | |
2700 | ||
2701 | return found ? false : -ENXIO; | |
2702 | } | |
2703 | ||
b652d4a2 LP |
2704 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2705 | assert(t); | |
2706 | assert(rr); | |
2707 | ||
2708 | /* We know that the root domain is signed, hence if it appears | |
2709 | * not to be signed, there's a problem with the DNS server */ | |
2710 | ||
2711 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2712 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2713 | } |
2714 | ||
0f87f3e8 LP |
2715 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2716 | DnsResourceRecord *rr; | |
2717 | int r; | |
2718 | ||
2719 | assert(t); | |
2720 | ||
2721 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2722 | * for a key from our trust anchor. Note that we don't care | |
2723 | * whether the DNSKEY can be authenticated or not. It's | |
2724 | * sufficient if it is self-signed. */ | |
2725 | ||
2726 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2727 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2728 | if (r < 0) |
2729 | return r; | |
2730 | } | |
2731 | ||
2732 | return 0; | |
2733 | } | |
2734 | ||
c9c72065 LP |
2735 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2736 | bool changed; | |
2737 | int r; | |
2738 | ||
2739 | assert(t); | |
2740 | ||
2741 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2742 | * our trust anchors database considers revoked. */ | |
2743 | ||
2744 | do { | |
2745 | DnsResourceRecord *rr; | |
2746 | ||
2747 | changed = false; | |
2748 | ||
2749 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2750 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2751 | if (r < 0) | |
2752 | return r; | |
2753 | if (r > 0) { | |
2754 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2755 | if (r < 0) | |
2756 | return r; | |
2757 | ||
2758 | assert(r > 0); | |
2759 | changed = true; | |
2760 | break; | |
2761 | } | |
2762 | } | |
2763 | } while (changed); | |
2764 | ||
2765 | return 0; | |
2766 | } | |
2767 | ||
942eb2e7 LP |
2768 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2769 | DnsTransaction *dt; | |
2770 | Iterator i; | |
2771 | int r; | |
2772 | ||
2773 | assert(t); | |
2774 | ||
2775 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2776 | ||
2777 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2778 | ||
2779 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2780 | continue; | |
2781 | ||
2782 | if (!dt->answer_authenticated) | |
2783 | continue; | |
2784 | ||
2785 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2786 | if (r < 0) | |
2787 | return r; | |
2788 | } | |
2789 | ||
2790 | return 0; | |
2791 | } | |
2792 | ||
c690b20a ZJS |
2793 | typedef enum { |
2794 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2795 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2796 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2797 | } Phase; | |
2798 | ||
2799 | static int dnssec_validate_records( | |
2800 | DnsTransaction *t, | |
2801 | Phase phase, | |
2802 | bool *have_nsec, | |
2803 | DnsAnswer **validated) { | |
2804 | ||
547973de | 2805 | DnsResourceRecord *rr; |
56352fe9 | 2806 | int r; |
547973de | 2807 | |
c690b20a | 2808 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2809 | |
c690b20a ZJS |
2810 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2811 | DnsResourceRecord *rrsig = NULL; | |
2812 | DnssecResult result; | |
547973de | 2813 | |
c690b20a ZJS |
2814 | switch (rr->key->type) { |
2815 | case DNS_TYPE_RRSIG: | |
2816 | continue; | |
547973de | 2817 | |
c690b20a ZJS |
2818 | case DNS_TYPE_DNSKEY: |
2819 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2820 | if (phase == DNSSEC_PHASE_NSEC) | |
2821 | continue; | |
2822 | break; | |
547973de | 2823 | |
c690b20a ZJS |
2824 | case DNS_TYPE_NSEC: |
2825 | case DNS_TYPE_NSEC3: | |
2826 | *have_nsec = true; | |
547973de | 2827 | |
c690b20a ZJS |
2828 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2829 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2830 | continue; | |
2831 | break; | |
105e1512 | 2832 | |
c690b20a ZJS |
2833 | default: |
2834 | /* We validate all other RRs only in the ALL phases */ | |
2835 | if (phase != DNSSEC_PHASE_ALL) | |
2836 | continue; | |
2837 | } | |
b652d4a2 | 2838 | |
c690b20a ZJS |
2839 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2840 | if (r < 0) | |
2841 | return r; | |
547973de | 2842 | |
c690b20a | 2843 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2844 | |
c690b20a | 2845 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2846 | |
c690b20a ZJS |
2847 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2848 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2849 | * the set of validated keys for this transaction. */ | |
547973de | 2850 | |
c690b20a ZJS |
2851 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2852 | if (r < 0) | |
2853 | return r; | |
c9c72065 | 2854 | |
c690b20a ZJS |
2855 | /* Some of the DNSKEYs we just added might already have been revoked, |
2856 | * remove them again in that case. */ | |
2857 | r = dns_transaction_invalidate_revoked_keys(t); | |
2858 | if (r < 0) | |
2859 | return r; | |
2860 | } | |
547973de | 2861 | |
c690b20a ZJS |
2862 | /* Add the validated RRset to the new list of validated |
2863 | * RRsets, and remove it from the unvalidated RRsets. | |
2864 | * We mark the RRset as authenticated and cacheable. */ | |
2865 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2866 | if (r < 0) | |
2867 | return r; | |
547973de | 2868 | |
c690b20a | 2869 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2870 | |
c690b20a ZJS |
2871 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2872 | return 1; | |
2873 | } | |
547973de | 2874 | |
c690b20a ZJS |
2875 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2876 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2877 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2878 | if (phase != DNSSEC_PHASE_ALL) | |
2879 | continue; | |
0c7bff0a | 2880 | |
c690b20a ZJS |
2881 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2882 | bool authenticated = false; | |
2883 | const char *source; | |
0c7bff0a | 2884 | |
c690b20a | 2885 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 2886 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 2887 | |
c690b20a ZJS |
2888 | /* First step, determine the source of synthesis */ |
2889 | r = dns_resource_record_source(rrsig, &source); | |
2890 | if (r < 0) | |
2891 | return r; | |
0c7bff0a | 2892 | |
c690b20a | 2893 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2894 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2895 | source, |
2896 | rrsig->rrsig.signer, | |
2897 | &authenticated); | |
0c7bff0a | 2898 | |
c690b20a ZJS |
2899 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2900 | if (r == 0) | |
2901 | result = DNSSEC_INVALID; | |
2902 | else { | |
2903 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2904 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2905 | if (r < 0) | |
2906 | return r; | |
2907 | ||
2908 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2909 | ||
2910 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2911 | return 1; | |
0c7bff0a | 2912 | } |
c690b20a | 2913 | } |
0c7bff0a | 2914 | |
c690b20a ZJS |
2915 | if (result == DNSSEC_NO_SIGNATURE) { |
2916 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2917 | if (r < 0) |
2918 | return r; | |
c690b20a ZJS |
2919 | if (r == 0) { |
2920 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 2921 | * but remember that this is by no means authenticated. */ |
c690b20a ZJS |
2922 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
2923 | if (r < 0) | |
2924 | return r; | |
2925 | ||
2926 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2927 | return 1; | |
2928 | } | |
547973de | 2929 | |
c690b20a ZJS |
2930 | r = dns_transaction_known_signed(t, rr); |
2931 | if (r < 0) | |
2932 | return r; | |
2933 | if (r > 0) { | |
2934 | /* This is an RR we know has to be signed. If it isn't this means | |
2935 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2936 | |
c690b20a | 2937 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2938 | |
c690b20a | 2939 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2940 | |
c690b20a | 2941 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2942 | |
c690b20a | 2943 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2944 | if (r < 0) |
2945 | return r; | |
547973de | 2946 | |
c690b20a ZJS |
2947 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2948 | return 1; | |
2949 | } | |
a150ff5e | 2950 | |
c690b20a ZJS |
2951 | /* Otherwise, fail */ |
2952 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2953 | return 0; | |
f3cf586d | 2954 | } |
547973de | 2955 | |
c690b20a ZJS |
2956 | r = dns_transaction_in_private_tld(t, rr->key); |
2957 | if (r < 0) | |
2958 | return r; | |
2959 | if (r > 0) { | |
202b76ae | 2960 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2961 | |
c690b20a ZJS |
2962 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2963 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2964 | |
202b76ae ZJS |
2965 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2966 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2967 | |
c690b20a | 2968 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2969 | if (r < 0) |
2970 | return r; | |
0c7bff0a | 2971 | |
c690b20a ZJS |
2972 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2973 | return 1; | |
2974 | } | |
2975 | } | |
0c7bff0a | 2976 | |
c690b20a ZJS |
2977 | if (IN_SET(result, |
2978 | DNSSEC_MISSING_KEY, | |
2979 | DNSSEC_SIGNATURE_EXPIRED, | |
2980 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2981 | |
c690b20a ZJS |
2982 | r = dns_transaction_dnskey_authenticated(t, rr); |
2983 | if (r < 0 && r != -ENXIO) | |
2984 | return r; | |
2985 | if (r == 0) { | |
2986 | /* The DNSKEY transaction was not authenticated, this means there's | |
2987 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2988 | |
c690b20a | 2989 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2990 | if (r < 0) |
2991 | return r; | |
b652d4a2 | 2992 | |
c690b20a ZJS |
2993 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2994 | return 1; | |
2995 | } | |
2996 | } | |
b652d4a2 | 2997 | |
c690b20a ZJS |
2998 | r = dns_transaction_is_primary_response(t, rr); |
2999 | if (r < 0) | |
3000 | return r; | |
3001 | if (r > 0) { | |
3002 | /* Look for a matching DNAME for this CNAME */ | |
3003 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
3004 | if (r < 0) | |
3005 | return r; | |
3006 | if (r == 0) { | |
3007 | /* Also look among the stuff we already validated */ | |
3008 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
3009 | if (r < 0) |
3010 | return r; | |
c690b20a | 3011 | } |
d33b6cf3 | 3012 | |
c690b20a ZJS |
3013 | if (r == 0) { |
3014 | if (IN_SET(result, | |
3015 | DNSSEC_INVALID, | |
3016 | DNSSEC_SIGNATURE_EXPIRED, | |
3017 | DNSSEC_NO_SIGNATURE)) | |
3018 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
3019 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
3020 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
3021 | ||
3022 | /* This is a primary response to our question, and it failed validation. | |
3023 | * That's fatal. */ | |
3024 | t->answer_dnssec_result = result; | |
3025 | return 0; | |
3026 | } | |
d33b6cf3 | 3027 | |
c690b20a ZJS |
3028 | /* This is a primary response, but we do have a DNAME RR |
3029 | * in the RR that can replay this CNAME, hence rely on | |
3030 | * that, and we can remove the CNAME in favour of it. */ | |
3031 | } | |
d33b6cf3 | 3032 | |
c690b20a ZJS |
3033 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
3034 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
3035 | if (r < 0) | |
3036 | return r; | |
d33b6cf3 | 3037 | |
c690b20a ZJS |
3038 | /* We dropped something from the answer, start from the beginning. */ |
3039 | return 1; | |
3040 | } | |
f3cf586d | 3041 | |
c690b20a ZJS |
3042 | return 2; /* Finito. */ |
3043 | } | |
94aa7071 | 3044 | |
c690b20a ZJS |
3045 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
3046 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
3047 | Phase phase; | |
3048 | DnsAnswerFlags flags; | |
3049 | int r; | |
202b76ae | 3050 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 3051 | |
c690b20a | 3052 | assert(t); |
94aa7071 | 3053 | |
c690b20a ZJS |
3054 | /* We have now collected all DS and DNSKEY RRs in |
3055 | * t->validated_keys, let's see which RRs we can now | |
3056 | * authenticate with that. */ | |
94aa7071 | 3057 | |
c690b20a ZJS |
3058 | if (t->scope->dnssec_mode == DNSSEC_NO) |
3059 | return 0; | |
a150ff5e | 3060 | |
c690b20a ZJS |
3061 | /* Already validated */ |
3062 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
3063 | return 0; | |
105e1512 | 3064 | |
c690b20a ZJS |
3065 | /* Our own stuff needs no validation */ |
3066 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
3067 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
3068 | t->answer_authenticated = true; | |
3069 | return 0; | |
3070 | } | |
a150ff5e | 3071 | |
c690b20a ZJS |
3072 | /* Cached stuff is not affected by validation. */ |
3073 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
3074 | return 0; | |
f3cf586d | 3075 | |
c690b20a ZJS |
3076 | if (!dns_transaction_dnssec_supported_full(t)) { |
3077 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3078 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3079 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3080 | return 0; |
3081 | } | |
f3cf586d | 3082 | |
202b76ae ZJS |
3083 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3084 | t->id, | |
3085 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 3086 | |
c690b20a ZJS |
3087 | /* First, see if this response contains any revoked trust |
3088 | * anchors we care about */ | |
3089 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3090 | if (r < 0) | |
3091 | return r; | |
43e6779a | 3092 | |
c690b20a ZJS |
3093 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3094 | r = dns_transaction_copy_validated(t); | |
3095 | if (r < 0) | |
3096 | return r; | |
43e6779a | 3097 | |
c690b20a ZJS |
3098 | /* Second, see if there are DNSKEYs we already know a |
3099 | * validated DS for. */ | |
3100 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3101 | if (r < 0) | |
3102 | return r; | |
43e6779a | 3103 | |
c690b20a ZJS |
3104 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3105 | * anchor says are revoked. After all we might have marked | |
3106 | * some keys revoked above, but they might still be lingering | |
3107 | * in our validated_keys list. */ | |
3108 | r = dns_transaction_invalidate_revoked_keys(t); | |
3109 | if (r < 0) | |
3110 | return r; | |
f3cf586d | 3111 | |
c690b20a ZJS |
3112 | phase = DNSSEC_PHASE_DNSKEY; |
3113 | for (;;) { | |
3114 | bool have_nsec = false; | |
f3cf586d | 3115 | |
c690b20a ZJS |
3116 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3117 | if (r <= 0) | |
3118 | return r; | |
547973de | 3119 | |
c690b20a ZJS |
3120 | /* Try again as long as we managed to achieve something */ |
3121 | if (r == 1) | |
547973de LP |
3122 | continue; |
3123 | ||
c690b20a | 3124 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3125 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3126 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3127 | continue; |
3128 | } | |
3129 | ||
c690b20a ZJS |
3130 | if (phase != DNSSEC_PHASE_ALL) { |
3131 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3132 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3133 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3134 | continue; |
547973de LP |
3135 | } |
3136 | ||
56352fe9 | 3137 | /* We're done */ |
547973de LP |
3138 | break; |
3139 | } | |
3140 | ||
3141 | dns_answer_unref(t->answer); | |
1cc6c93a | 3142 | t->answer = TAKE_PTR(validated); |
547973de | 3143 | |
72667f08 LP |
3144 | /* At this point the answer only contains validated |
3145 | * RRsets. Now, let's see if it actually answers the question | |
3146 | * we asked. If so, great! If it doesn't, then see if | |
3147 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3148 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3149 | if (r > 0) { |
105e1512 LP |
3150 | /* Yes, it answers the question! */ |
3151 | ||
3152 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3153 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3154 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3155 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3156 | t->answer_authenticated = true; | |
3157 | } else { | |
3158 | /* The answer is not fully authenticated. */ | |
019036a4 | 3159 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3160 | t->answer_authenticated = false; |
3161 | } | |
3162 | ||
72667f08 LP |
3163 | } else if (r == 0) { |
3164 | DnssecNsecResult nr; | |
ed29bfdc | 3165 | bool authenticated = false; |
72667f08 LP |
3166 | |
3167 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3168 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3169 | if (r < 0) |
3170 | return r; | |
3171 | ||
3172 | switch (nr) { | |
3173 | ||
3174 | case DNSSEC_NSEC_NXDOMAIN: | |
3175 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3176 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3177 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3178 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3179 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3180 | |
59c5b597 | 3181 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3182 | break; |
3183 | ||
3184 | case DNSSEC_NSEC_NODATA: | |
3185 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3186 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3187 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3188 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3189 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3190 | |
59c5b597 | 3191 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3192 | break; |
3193 | ||
105e1512 LP |
3194 | case DNSSEC_NSEC_OPTOUT: |
3195 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3196 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3197 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3198 | t->answer_authenticated = false; |
7aa8ce98 | 3199 | |
59c5b597 | 3200 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3201 | break; |
3202 | ||
72667f08 LP |
3203 | case DNSSEC_NSEC_NO_RR: |
3204 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3205 | |
3206 | r = dns_transaction_requires_nsec(t); | |
3207 | if (r < 0) | |
3208 | return r; | |
7aa8ce98 | 3209 | if (r > 0) { |
019036a4 | 3210 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3211 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3212 | } else { |
019036a4 | 3213 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3214 | t->answer_authenticated = false; |
59c5b597 | 3215 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3216 | } |
3217 | ||
3218 | break; | |
3219 | ||
3220 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3221 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3222 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3223 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3224 | break; |
3225 | ||
3226 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3227 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3228 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3229 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3230 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3231 | break; |
3232 | ||
3233 | default: | |
3234 | assert_not_reached("Unexpected NSEC result."); | |
3235 | } | |
3236 | } | |
3237 | ||
547973de LP |
3238 | return 1; |
3239 | } | |
3240 | ||
ec2c5e43 LP |
3241 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3242 | [DNS_TRANSACTION_NULL] = "null", | |
3243 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3244 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3245 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3246 | [DNS_TRANSACTION_SUCCESS] = "success", |
3247 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3248 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3249 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3250 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3251 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3252 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3253 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3254 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3255 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3256 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3257 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3258 | }; |
3259 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3260 | |
3261 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3262 | [DNS_TRANSACTION_NETWORK] = "network", | |
3263 | [DNS_TRANSACTION_CACHE] = "cache", | |
3264 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3265 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3266 | }; |
3267 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |