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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
ec2c5e43 | 2 | |
62cc1c55 | 3 | #include "sd-messages.h" |
beef6a5f | 4 | |
ec2c5e43 | 5 | #include "af-list.h" |
b5efdb8a | 6 | #include "alloc-util.h" |
f52e61da | 7 | #include "dns-domain.h" |
7cc6ed7b | 8 | #include "errno-list.h" |
c3fecddf | 9 | #include "errno-util.h" |
3ffd4af2 LP |
10 | #include "fd-util.h" |
11 | #include "random-util.h" | |
7778dfff | 12 | #include "resolved-dns-cache.h" |
3ffd4af2 | 13 | #include "resolved-dns-transaction.h" |
6016fcb0 | 14 | #include "resolved-dnstls.h" |
aedf00a2 | 15 | #include "resolved-llmnr.h" |
6016fcb0 | 16 | #include "string-table.h" |
5d67a7ae | 17 | |
b214dc0f | 18 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 19 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 20 | |
dbc4661a MCO |
21 | /* After how much time to repeat classic DNS requests */ |
22 | #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX) | |
23 | ||
c61d2b44 LP |
24 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
25 | assert(t); | |
26 | ||
27 | t->received = dns_packet_unref(t->received); | |
28 | t->answer = dns_answer_unref(t->answer); | |
29 | t->answer_rcode = 0; | |
30 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
31 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
6f055e43 | 32 | t->answer_query_flags = 0; |
d3760be0 | 33 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 34 | t->answer_errno = 0; |
c61d2b44 LP |
35 | } |
36 | ||
c5b4f861 LP |
37 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
38 | DnsTransaction *z; | |
39 | ||
40 | assert(t); | |
41 | ||
42 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
43 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 44 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
45 | dns_transaction_gc(z); |
46 | } | |
47 | } | |
48 | ||
80710ade LP |
49 | static void dns_transaction_close_connection( |
50 | DnsTransaction *t, | |
51 | bool use_graveyard) { /* Set use_graveyard = false when you know the connection is already | |
52 | * dead, for example because you got a connection error back from the | |
53 | * kernel. In that case there's no point in keeping the fd around, | |
54 | * hence don't. */ | |
55 | int r; | |
56 | ||
f32f0e57 LP |
57 | assert(t); |
58 | ||
b30bf55d LP |
59 | if (t->stream) { |
60 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
98767d75 IT |
61 | LIST_REMOVE(transactions_by_stream, t->stream->transactions, t); |
62 | ||
63 | /* Remove packet in case it's still in the queue */ | |
64 | dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent)); | |
65 | ||
b30bf55d LP |
66 | t->stream = dns_stream_unref(t->stream); |
67 | } | |
68 | ||
f32f0e57 | 69 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
80710ade LP |
70 | |
71 | /* If we have an UDP socket where we sent a packet, but never received one, then add it to the socket | |
72 | * graveyard, instead of closing it right away. That way it will stick around for a moment longer, | |
73 | * and the reply we might still get from the server will be eaten up instead of resulting in an ICMP | |
74 | * port unreachable error message. */ | |
75 | ||
76 | if (use_graveyard && t->dns_udp_fd >= 0 && t->sent && !t->received) { | |
77 | r = manager_add_socket_to_graveyard(t->scope->manager, t->dns_udp_fd); | |
78 | if (r < 0) | |
79 | log_debug_errno(r, "Failed to add UDP socket to graveyard, closing immediately: %m"); | |
80 | else | |
81 | TAKE_FD(t->dns_udp_fd); | |
82 | } | |
83 | ||
f32f0e57 LP |
84 | t->dns_udp_fd = safe_close(t->dns_udp_fd); |
85 | } | |
86 | ||
f535705a | 87 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
88 | assert(t); |
89 | ||
90 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
91 | } |
92 | ||
ec2c5e43 | 93 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 94 | DnsQueryCandidate *c; |
ec2c5e43 | 95 | DnsZoneItem *i; |
547973de | 96 | DnsTransaction *z; |
ec2c5e43 LP |
97 | |
98 | if (!t) | |
99 | return NULL; | |
100 | ||
51e399bc LP |
101 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
102 | ||
80710ade | 103 | dns_transaction_close_connection(t, true); |
f535705a | 104 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 105 | |
ec2c5e43 | 106 | dns_packet_unref(t->sent); |
c61d2b44 | 107 | dns_transaction_reset_answer(t); |
ec2c5e43 | 108 | |
8300ba21 | 109 | dns_server_unref(t->server); |
ec2c5e43 LP |
110 | |
111 | if (t->scope) { | |
775ae354 LP |
112 | if (t->key) { |
113 | DnsTransaction *first; | |
114 | ||
115 | first = hashmap_get(t->scope->transactions_by_key, t->key); | |
116 | LIST_REMOVE(transactions_by_key, first, t); | |
117 | if (first) | |
118 | hashmap_replace(t->scope->transactions_by_key, first->key, first); | |
119 | else | |
120 | hashmap_remove(t->scope->transactions_by_key, t->key); | |
121 | } | |
ec2c5e43 | 122 | |
775ae354 | 123 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); |
ec2c5e43 LP |
124 | } |
125 | ||
775ae354 LP |
126 | if (t->id != 0) |
127 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
128 | ||
547973de | 129 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 130 | set_remove(c->transactions, t); |
547973de | 131 | set_free(t->notify_query_candidates); |
801ad6a6 | 132 | |
35aa04e9 LP |
133 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
134 | set_remove(c->transactions, t); | |
135 | set_free(t->notify_query_candidates_done); | |
136 | ||
547973de | 137 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 138 | i->probe_transaction = NULL; |
547973de LP |
139 | set_free(t->notify_zone_items); |
140 | ||
35aa04e9 LP |
141 | while ((i = set_steal_first(t->notify_zone_items_done))) |
142 | i->probe_transaction = NULL; | |
143 | set_free(t->notify_zone_items_done); | |
144 | ||
547973de LP |
145 | while ((z = set_steal_first(t->notify_transactions))) |
146 | set_remove(z->dnssec_transactions, t); | |
147 | set_free(t->notify_transactions); | |
148 | ||
35aa04e9 LP |
149 | while ((z = set_steal_first(t->notify_transactions_done))) |
150 | set_remove(z->dnssec_transactions, t); | |
151 | set_free(t->notify_transactions_done); | |
152 | ||
c5b4f861 | 153 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
154 | set_free(t->dnssec_transactions); |
155 | ||
156 | dns_answer_unref(t->validated_keys); | |
97cc656c | 157 | dns_resource_key_unref(t->key); |
775ae354 | 158 | dns_packet_unref(t->bypass); |
97cc656c | 159 | |
6b430fdb | 160 | return mfree(t); |
ec2c5e43 LP |
161 | } |
162 | ||
163 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
164 | ||
51e399bc | 165 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
166 | assert(t); |
167 | ||
168 | if (t->block_gc > 0) | |
51e399bc | 169 | return true; |
ec2c5e43 | 170 | |
547973de | 171 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 172 | set_isempty(t->notify_query_candidates_done) && |
547973de | 173 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
174 | set_isempty(t->notify_zone_items_done) && |
175 | set_isempty(t->notify_transactions) && | |
176 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 177 | dns_transaction_free(t); |
51e399bc LP |
178 | return false; |
179 | } | |
180 | ||
181 | return true; | |
ec2c5e43 LP |
182 | } |
183 | ||
4dd15077 LP |
184 | static uint16_t pick_new_id(Manager *m) { |
185 | uint16_t new_id; | |
186 | ||
4ea8b443 ZJS |
187 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the |
188 | * number of transactions, and it's much lower than the space of IDs. */ | |
4dd15077 LP |
189 | |
190 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
191 | ||
192 | do | |
193 | random_bytes(&new_id, sizeof(new_id)); | |
194 | while (new_id == 0 || | |
195 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
196 | ||
197 | return new_id; | |
198 | } | |
199 | ||
775ae354 LP |
200 | static int key_ok( |
201 | DnsScope *scope, | |
202 | DnsResourceKey *key) { | |
ec2c5e43 | 203 | |
9eae2bf3 | 204 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 205 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 206 | return -EINVAL; |
d0129ddb LP |
207 | if (dns_type_is_obsolete(key->type)) |
208 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
209 | |
210 | /* We only support the IN class */ | |
4c701096 | 211 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
212 | return -EOPNOTSUPP; |
213 | ||
775ae354 LP |
214 | /* Don't allows DNSSEC RRs to be looked up via LLMNR/mDNS. They don't really make sense |
215 | * there, and it speeds up our queries if we refuse this early */ | |
216 | if (scope->protocol != DNS_PROTOCOL_DNS && | |
217 | dns_type_is_dnssec(key->type)) | |
218 | return -EOPNOTSUPP; | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | int dns_transaction_new( | |
224 | DnsTransaction **ret, | |
225 | DnsScope *s, | |
226 | DnsResourceKey *key, | |
227 | DnsPacket *bypass, | |
228 | uint64_t query_flags) { | |
229 | ||
230 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; | |
231 | int r; | |
232 | ||
233 | assert(ret); | |
234 | assert(s); | |
235 | ||
236 | if (key) { | |
237 | assert(!bypass); | |
238 | ||
239 | r = key_ok(s, key); | |
240 | if (r < 0) | |
241 | return r; | |
242 | } else { | |
243 | DnsResourceKey *qk; | |
244 | assert(bypass); | |
245 | ||
246 | r = dns_packet_validate_query(bypass); | |
247 | if (r < 0) | |
248 | return r; | |
249 | ||
250 | DNS_QUESTION_FOREACH(qk, bypass->question) { | |
251 | r = key_ok(s, qk); | |
252 | if (r < 0) | |
253 | return r; | |
254 | } | |
255 | } | |
256 | ||
b214dc0f LP |
257 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
258 | return -EBUSY; | |
259 | ||
d5099efc | 260 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
261 | if (r < 0) |
262 | return r; | |
263 | ||
775ae354 LP |
264 | if (key) { |
265 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); | |
266 | if (r < 0) | |
267 | return r; | |
268 | } | |
da0c630e | 269 | |
1ed31408 | 270 | t = new(DnsTransaction, 1); |
ec2c5e43 LP |
271 | if (!t) |
272 | return -ENOMEM; | |
273 | ||
1ed31408 LP |
274 | *t = (DnsTransaction) { |
275 | .dns_udp_fd = -1, | |
276 | .answer_source = _DNS_TRANSACTION_SOURCE_INVALID, | |
277 | .answer_dnssec_result = _DNSSEC_RESULT_INVALID, | |
278 | .answer_nsec_ttl = (uint32_t) -1, | |
279 | .key = dns_resource_key_ref(key), | |
775ae354 LP |
280 | .query_flags = query_flags, |
281 | .bypass = dns_packet_ref(bypass), | |
1ed31408 LP |
282 | .current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID, |
283 | .clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID, | |
284 | .id = pick_new_id(s->manager), | |
285 | }; | |
ec2c5e43 LP |
286 | |
287 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
288 | if (r < 0) { | |
289 | t->id = 0; | |
290 | return r; | |
291 | } | |
292 | ||
775ae354 LP |
293 | if (t->key) { |
294 | DnsTransaction *first; | |
295 | ||
296 | first = hashmap_get(s->transactions_by_key, t->key); | |
297 | LIST_PREPEND(transactions_by_key, first, t); | |
298 | ||
299 | r = hashmap_replace(s->transactions_by_key, first->key, first); | |
300 | if (r < 0) { | |
301 | LIST_REMOVE(transactions_by_key, first, t); | |
302 | return r; | |
303 | } | |
da0c630e LP |
304 | } |
305 | ||
f9ebb22a | 306 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
307 | t->scope = s; |
308 | ||
313cefa1 | 309 | s->manager->n_transactions_total++; |
a150ff5e | 310 | |
ec2c5e43 LP |
311 | if (ret) |
312 | *ret = t; | |
313 | ||
775ae354 | 314 | TAKE_PTR(t); |
ec2c5e43 LP |
315 | return 0; |
316 | } | |
317 | ||
4dd15077 LP |
318 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
319 | uint16_t new_id; | |
320 | assert(t); | |
321 | ||
322 | /* Pick a new ID for this transaction. */ | |
323 | ||
324 | new_id = pick_new_id(t->scope->manager); | |
325 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
326 | ||
327 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
328 | t->id = new_id; | |
329 | ||
330 | /* Make sure we generate a new packet with the new ID */ | |
331 | t->sent = dns_packet_unref(t->sent); | |
332 | } | |
333 | ||
ec2c5e43 | 334 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 335 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 336 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 337 | DnsZoneItem *z; |
ec2c5e43 LP |
338 | |
339 | assert(t); | |
340 | assert(p); | |
94378145 | 341 | assert(t->scope->protocol == DNS_PROTOCOL_LLMNR); |
ec2c5e43 | 342 | |
94378145 | 343 | if (manager_packet_from_local_address(t->scope->manager, p) != 0) |
ec2c5e43 LP |
344 | return; |
345 | ||
164d025d | 346 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 347 | |
a5784c49 LP |
348 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
349 | t->id, | |
42df9532 | 350 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
ec2c5e43 | 351 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 352 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 353 | af_to_name_short(t->scope->family), |
164d025d | 354 | strnull(pretty)); |
ec2c5e43 | 355 | |
a4076574 LP |
356 | /* RFC 4795, Section 4.1 says that the peer with the |
357 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
358 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
359 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
360 | return; |
361 | } | |
362 | ||
4d91eec4 | 363 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 364 | |
ec2c5e43 | 365 | t->block_gc++; |
35aa04e9 | 366 | |
547973de | 367 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
368 | /* First, make sure the zone item drops the reference |
369 | * to us */ | |
370 | dns_zone_item_probe_stop(z); | |
371 | ||
372 | /* Secondly, report this as conflict, so that we might | |
373 | * look for a different hostname */ | |
ec2c5e43 | 374 | dns_zone_item_conflict(z); |
3ef64445 | 375 | } |
ec2c5e43 LP |
376 | t->block_gc--; |
377 | ||
378 | dns_transaction_gc(t); | |
379 | } | |
380 | ||
381 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 382 | DnsQueryCandidate *c; |
ec2c5e43 | 383 | DnsZoneItem *z; |
547973de | 384 | DnsTransaction *d; |
7cc6ed7b | 385 | const char *st; |
202b76ae | 386 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
387 | |
388 | assert(t); | |
547973de | 389 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 390 | |
202b76ae | 391 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
42df9532 | 392 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str); |
202b76ae | 393 | |
f61dfddb | 394 | log_struct(LOG_NOTICE, |
2b044526 | 395 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
202b76ae | 396 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 397 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 398 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 399 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
8aa5afd2 | 400 | "DNS_SERVER=%s", strna(dns_server_string_full(t->server)), |
a1230ff9 | 401 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level)); |
202b76ae | 402 | } |
f61dfddb | 403 | |
ec2c5e43 LP |
404 | /* Note that this call might invalidate the query. Callers |
405 | * should hence not attempt to access the query or transaction | |
406 | * after calling this function. */ | |
407 | ||
7cc6ed7b LP |
408 | if (state == DNS_TRANSACTION_ERRNO) |
409 | st = errno_to_name(t->answer_errno); | |
410 | else | |
411 | st = dns_transaction_state_to_string(state); | |
412 | ||
43fc4baa | 413 | log_debug("%s transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s; %s).", |
775ae354 | 414 | t->bypass ? "Bypass" : "Regular", |
a5784c49 | 415 | t->id, |
42df9532 | 416 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
ec2c5e43 | 417 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 418 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 419 | af_to_name_short(t->scope->family), |
7cc6ed7b | 420 | st, |
a5784c49 | 421 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
775ae354 | 422 | FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) ? "not validated" : |
43fc4baa LP |
423 | (FLAGS_SET(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED) ? "authenticated" : "unsigned"), |
424 | FLAGS_SET(t->answer_query_flags, SD_RESOLVED_CONFIDENTIAL) ? "confidential" : "non-confidential"); | |
ec2c5e43 LP |
425 | |
426 | t->state = state; | |
427 | ||
80710ade | 428 | dns_transaction_close_connection(t, true); |
f535705a | 429 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
430 | |
431 | /* Notify all queries that are interested, but make sure the | |
432 | * transaction isn't freed while we are still looking at it */ | |
433 | t->block_gc++; | |
f7014757 | 434 | |
35aa04e9 | 435 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 436 | dns_query_candidate_notify(c); |
35aa04e9 | 437 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 438 | |
35aa04e9 LP |
439 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
440 | dns_zone_item_notify(z); | |
441 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
8d67e72c | 442 | if (t->probing && t->state == DNS_TRANSACTION_ATTEMPTS_MAX_REACHED) |
1a63fc54 | 443 | (void) dns_scope_announce(t->scope, false); |
f7014757 | 444 | |
35aa04e9 LP |
445 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
446 | dns_transaction_notify(d, t); | |
447 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
448 | |
449 | t->block_gc--; | |
ec2c5e43 LP |
450 | dns_transaction_gc(t); |
451 | } | |
452 | ||
fd8a3017 LP |
453 | static void dns_transaction_complete_errno(DnsTransaction *t, int error) { |
454 | assert(t); | |
455 | assert(error != 0); | |
456 | ||
457 | t->answer_errno = abs(error); | |
458 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
459 | } | |
460 | ||
519ef046 LP |
461 | static int dns_transaction_pick_server(DnsTransaction *t) { |
462 | DnsServer *server; | |
463 | ||
464 | assert(t); | |
465 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
466 | ||
d001e0a3 LP |
467 | /* Pick a DNS server and a feature level for it. */ |
468 | ||
519ef046 LP |
469 | server = dns_scope_get_dns_server(t->scope); |
470 | if (!server) | |
471 | return -ESRCH; | |
472 | ||
d001e0a3 LP |
473 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
474 | * different properties. */ | |
475 | if (server != t->server) | |
476 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
477 | ||
274b8748 | 478 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 479 | |
d001e0a3 LP |
480 | /* Clamp the feature level if that is requested. */ |
481 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
482 | t->current_feature_level > t->clamp_feature_level) | |
483 | t->current_feature_level = t->clamp_feature_level; | |
484 | ||
485 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
486 | ||
519ef046 LP |
487 | if (server == t->server) |
488 | return 0; | |
489 | ||
490 | dns_server_unref(t->server); | |
491 | t->server = dns_server_ref(server); | |
492 | ||
44db02d0 LP |
493 | t->n_picked_servers ++; |
494 | ||
8aa5afd2 | 495 | log_debug("Using DNS server %s for transaction %u.", strna(dns_server_string_full(t->server)), t->id); |
d001e0a3 | 496 | |
519ef046 LP |
497 | return 1; |
498 | } | |
499 | ||
d001e0a3 | 500 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
501 | int r; |
502 | ||
503 | assert(t); | |
504 | ||
505 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
506 | ||
507 | /* Before we try again, switch to a new server. */ | |
d001e0a3 | 508 | if (next_server) |
5e8bc852 | 509 | dns_scope_next_dns_server(t->scope, t->server); |
8d10d620 LP |
510 | |
511 | r = dns_transaction_go(t); | |
fd8a3017 LP |
512 | if (r < 0) |
513 | dns_transaction_complete_errno(t, r); | |
8d10d620 LP |
514 | } |
515 | ||
c02cf2f4 | 516 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
517 | int r; |
518 | ||
c02cf2f4 LP |
519 | assert(t); |
520 | ||
5278bbfe LP |
521 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
522 | ||
c02cf2f4 LP |
523 | if (!t->server) |
524 | return 0; | |
525 | ||
526 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
527 | return 0; | |
528 | ||
529 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
530 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
531 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
532 | OPT RR or DO bit. One of these cases is documented here, for example: | |
533 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
534 | ||
4dd15077 LP |
535 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
536 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
537 | |
538 | r = dns_transaction_go(t); | |
539 | if (r < 0) | |
540 | return r; | |
541 | ||
542 | return 1; | |
c02cf2f4 LP |
543 | } |
544 | ||
98767d75 IT |
545 | static void on_transaction_stream_error(DnsTransaction *t, int error) { |
546 | assert(t); | |
ec2c5e43 | 547 | |
80710ade | 548 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 549 | |
a1a3f73a | 550 | if (ERRNO_IS_DISCONNECT(error)) { |
0791110f LP |
551 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
552 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
553 | * question on this scope. */ | |
554 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
daab72ea | 555 | return; |
0791110f LP |
556 | } |
557 | ||
d001e0a3 | 558 | dns_transaction_retry(t, true); |
daab72ea | 559 | return; |
ac720200 | 560 | } |
fd8a3017 LP |
561 | if (error != 0) |
562 | dns_transaction_complete_errno(t, error); | |
98767d75 IT |
563 | } |
564 | ||
43fc4baa LP |
565 | static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsStream *s, DnsPacket *p) { |
566 | bool encrypted; | |
567 | ||
98767d75 | 568 | assert(t); |
43fc4baa | 569 | assert(s); |
98767d75 IT |
570 | assert(p); |
571 | ||
43fc4baa LP |
572 | encrypted = s->encrypted; |
573 | ||
80710ade | 574 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 575 | |
a4076574 | 576 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 577 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
578 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
579 | return 0; | |
580 | } | |
581 | ||
582 | dns_scope_check_conflicts(t->scope, p); | |
583 | ||
ec2c5e43 | 584 | t->block_gc++; |
43fc4baa | 585 | dns_transaction_process_reply(t, p, encrypted); |
ec2c5e43 LP |
586 | t->block_gc--; |
587 | ||
519ef046 LP |
588 | /* If the response wasn't useful, then complete the transition |
589 | * now. After all, we are the worst feature set now with TCP | |
590 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
591 | if (t->state == DNS_TRANSACTION_PENDING) |
592 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
593 | else |
594 | dns_transaction_gc(t); | |
ec2c5e43 LP |
595 | |
596 | return 0; | |
597 | } | |
598 | ||
98767d75 | 599 | static int on_stream_complete(DnsStream *s, int error) { |
7172e4ee | 600 | assert(s); |
98767d75 IT |
601 | |
602 | if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) { | |
98767d75 IT |
603 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
604 | ||
605 | if (s->transactions) { | |
97d5d905 LP |
606 | DnsTransaction *t; |
607 | ||
98767d75 | 608 | t = s->transactions; |
3da3cdd5 | 609 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level); |
98767d75 IT |
610 | } |
611 | } | |
612 | ||
97d5d905 LP |
613 | if (error != 0) { |
614 | DnsTransaction *t, *n; | |
615 | ||
616 | LIST_FOREACH_SAFE(transactions_by_stream, t, n, s->transactions) | |
98767d75 | 617 | on_transaction_stream_error(t, error); |
97d5d905 | 618 | } |
98767d75 | 619 | |
97d5d905 | 620 | return 0; |
98767d75 IT |
621 | } |
622 | ||
747a8a74 | 623 | static int on_stream_packet(DnsStream *s) { |
98767d75 | 624 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
98767d75 IT |
625 | DnsTransaction *t; |
626 | ||
aa337a5e LP |
627 | assert(s); |
628 | ||
98767d75 | 629 | /* Take ownership of packet to be able to receive new packets */ |
43fc4baa | 630 | assert_se(p = dns_stream_take_read_packet(s)); |
98767d75 IT |
631 | |
632 | t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); | |
aa337a5e | 633 | if (t) |
43fc4baa | 634 | return dns_transaction_on_stream_packet(t, s, p); |
98767d75 | 635 | |
8227cfa1 | 636 | /* Ignore incorrect transaction id as an old transaction can have been canceled. */ |
30f9e0bf | 637 | log_debug("Received unexpected TCP reply packet with id %" PRIu16 ", ignoring.", DNS_PACKET_ID(p)); |
aa337a5e | 638 | return 0; |
98767d75 IT |
639 | } |
640 | ||
da9de738 | 641 | static uint16_t dns_transaction_port(DnsTransaction *t) { |
775ae354 LP |
642 | assert(t); |
643 | ||
da9de738 YW |
644 | if (t->server->port > 0) |
645 | return t->server->port; | |
775ae354 | 646 | |
da9de738 | 647 | return DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53; |
ec962fba LP |
648 | } |
649 | ||
98767d75 | 650 | static int dns_transaction_emit_tcp(DnsTransaction *t) { |
98767d75 | 651 | _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; |
652ba568 | 652 | _cleanup_close_ int fd = -1; |
91ccab1e | 653 | union sockaddr_union sa; |
652ba568 | 654 | DnsStreamType type; |
ec2c5e43 LP |
655 | int r; |
656 | ||
657 | assert(t); | |
775ae354 | 658 | assert(t->sent); |
ec2c5e43 | 659 | |
80710ade | 660 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 661 | |
106784eb | 662 | switch (t->scope->protocol) { |
519ef046 | 663 | |
106784eb | 664 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
665 | r = dns_transaction_pick_server(t); |
666 | if (r < 0) | |
667 | return r; | |
668 | ||
49ef064c LP |
669 | if (manager_server_is_stub(t->scope->manager, t->server)) |
670 | return -ELOOP; | |
671 | ||
775ae354 LP |
672 | if (!t->bypass) { |
673 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) | |
674 | return -EOPNOTSUPP; | |
91adc4db | 675 | |
775ae354 LP |
676 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
677 | if (r < 0) | |
678 | return r; | |
679 | } | |
519ef046 | 680 | |
5d67a7ae | 681 | if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted)) |
98767d75 IT |
682 | s = dns_stream_ref(t->server->stream); |
683 | else | |
da9de738 | 684 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, dns_transaction_port(t), &sa); |
98767d75 | 685 | |
652ba568 | 686 | type = DNS_STREAM_LOOKUP; |
106784eb | 687 | break; |
ec2c5e43 | 688 | |
106784eb | 689 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 690 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 691 | if (t->received) |
91ccab1e | 692 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa); |
ec2c5e43 LP |
693 | else { |
694 | union in_addr_union address; | |
a7f7d1bd | 695 | int family = AF_UNSPEC; |
ec2c5e43 LP |
696 | |
697 | /* Otherwise, try to talk to the owner of a | |
698 | * the IP address, in case this is a reverse | |
699 | * PTR lookup */ | |
f52e61da | 700 | |
42df9532 | 701 | r = dns_name_address(dns_resource_key_name(dns_transaction_key(t)), &family, &address); |
ec2c5e43 LP |
702 | if (r < 0) |
703 | return r; | |
704 | if (r == 0) | |
705 | return -EINVAL; | |
9e08a6e0 | 706 | if (family != t->scope->family) |
9318cdd3 | 707 | return -ESRCH; |
ec2c5e43 | 708 | |
91ccab1e | 709 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa); |
ec2c5e43 | 710 | } |
106784eb | 711 | |
652ba568 | 712 | type = DNS_STREAM_LLMNR_SEND; |
106784eb DM |
713 | break; |
714 | ||
715 | default: | |
ec2c5e43 | 716 | return -EAFNOSUPPORT; |
106784eb | 717 | } |
ec2c5e43 | 718 | |
98767d75 IT |
719 | if (!s) { |
720 | if (fd < 0) | |
721 | return fd; | |
ec2c5e43 | 722 | |
652ba568 | 723 | r = dns_stream_new(t->scope->manager, &s, type, t->scope->protocol, fd, &sa); |
98767d75 IT |
724 | if (r < 0) |
725 | return r; | |
726 | ||
727 | fd = -1; | |
728 | ||
56ddbf10 | 729 | #if ENABLE_DNS_OVER_TLS |
199dda9c LP |
730 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
731 | DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) { | |
732 | ||
b02a7e1a | 733 | assert(t->server); |
6016fcb0 | 734 | r = dnstls_stream_connect_tls(s, t->server); |
5d67a7ae IT |
735 | if (r < 0) |
736 | return r; | |
737 | } | |
738 | #endif | |
739 | ||
19feb28f | 740 | if (t->server) { |
904dcaf9 | 741 | dns_server_unref_stream(t->server); |
19feb28f | 742 | s->server = dns_server_ref(t->server); |
8227cfa1 | 743 | t->server->stream = dns_stream_ref(s); |
19feb28f IT |
744 | } |
745 | ||
98767d75 | 746 | s->complete = on_stream_complete; |
747a8a74 | 747 | s->on_packet = on_stream_packet; |
98767d75 IT |
748 | |
749 | /* The interface index is difficult to determine if we are | |
750 | * connecting to the local host, hence fill this in right away | |
751 | * instead of determining it from the socket */ | |
752 | s->ifindex = dns_scope_ifindex(t->scope); | |
753 | } | |
754 | ||
755 | t->stream = TAKE_PTR(s); | |
756 | LIST_PREPEND(transactions_by_stream, t->stream->transactions, t); | |
ec2c5e43 LP |
757 | |
758 | r = dns_stream_write_packet(t->stream, t->sent); | |
759 | if (r < 0) { | |
80710ade | 760 | dns_transaction_close_connection(t, /* use_graveyard= */ false); |
ec2c5e43 LP |
761 | return r; |
762 | } | |
763 | ||
519ef046 LP |
764 | dns_transaction_reset_answer(t); |
765 | ||
cbe4216d LP |
766 | t->tried_stream = true; |
767 | ||
ec2c5e43 LP |
768 | return 0; |
769 | } | |
770 | ||
547973de | 771 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
772 | assert(t); |
773 | ||
774 | /* For mDNS we cache whenever we get the packet, rather than | |
775 | * in each transaction. */ | |
776 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
777 | return; | |
778 | ||
ceeddf79 | 779 | /* Caching disabled? */ |
37d7a7d9 | 780 | if (t->scope->manager->enable_cache == DNS_CACHE_MODE_NO) |
ceeddf79 MP |
781 | return; |
782 | ||
775ae354 LP |
783 | /* If validation is turned off for this transaction, but DNSSEC is on, then let's not cache this */ |
784 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) && t->scope->dnssec_mode != DNSSEC_NO) | |
785 | return; | |
786 | ||
6d8325f6 PS |
787 | /* Packet from localhost? */ |
788 | if (!t->scope->manager->cache_from_localhost && | |
789 | in_addr_is_localhost(t->received->family, &t->received->sender) != 0) | |
547973de LP |
790 | return; |
791 | ||
547973de | 792 | dns_cache_put(&t->scope->cache, |
37d7a7d9 | 793 | t->scope->manager->enable_cache, |
42df9532 | 794 | dns_transaction_key(t), |
547973de LP |
795 | t->answer_rcode, |
796 | t->answer, | |
775ae354 LP |
797 | DNS_PACKET_CD(t->received) ? t->received : NULL, /* only cache full packets with CD on, |
798 | * since our usecase for caching them | |
799 | * is "bypass" mode which is only | |
800 | * enabled for CD packets. */ | |
6f055e43 | 801 | t->answer_query_flags, |
775ae354 | 802 | t->answer_dnssec_result, |
d3760be0 | 803 | t->answer_nsec_ttl, |
547973de LP |
804 | t->received->family, |
805 | &t->received->sender); | |
806 | } | |
807 | ||
105e1512 LP |
808 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
809 | DnsTransaction *dt; | |
105e1512 LP |
810 | |
811 | assert(t); | |
812 | ||
90e74a66 | 813 | SET_FOREACH(dt, t->dnssec_transactions) |
105e1512 LP |
814 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) |
815 | return true; | |
816 | ||
817 | return false; | |
818 | } | |
819 | ||
942eb2e7 LP |
820 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
821 | DnsTransaction *dt; | |
942eb2e7 LP |
822 | |
823 | assert(t); | |
824 | ||
825 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
826 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
827 | ||
90e74a66 | 828 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
829 | |
830 | switch (dt->state) { | |
831 | ||
832 | case DNS_TRANSACTION_NULL: | |
833 | case DNS_TRANSACTION_PENDING: | |
834 | case DNS_TRANSACTION_VALIDATING: | |
835 | /* Still ongoing */ | |
836 | return 0; | |
837 | ||
838 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 839 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
840 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
841 | goto fail; | |
842 | } | |
843 | ||
b3c6b00a | 844 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
5238e957 | 845 | * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS |
b3c6b00a LP |
846 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar |
847 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
848 | |
849 | case DNS_TRANSACTION_SUCCESS: | |
850 | /* All good. */ | |
851 | break; | |
852 | ||
853 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
854 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
855 | * validationr result */ | |
856 | ||
857 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
858 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
859 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
860 | return 0; | |
861 | ||
942eb2e7 LP |
862 | default: |
863 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
864 | goto fail; | |
865 | } | |
866 | } | |
867 | ||
868 | /* All is ready, we can go and validate */ | |
869 | return 1; | |
870 | ||
871 | fail: | |
872 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
873 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
874 | return 0; | |
875 | } | |
876 | ||
547973de LP |
877 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
878 | int r; | |
879 | ||
880 | assert(t); | |
881 | ||
882 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 883 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
884 | if (r < 0) |
885 | goto fail; | |
942eb2e7 | 886 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
887 | return; |
888 | ||
c02cf2f4 LP |
889 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
890 | * restart the lookup immediately. */ | |
891 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
892 | if (r < 0) |
893 | goto fail; | |
c02cf2f4 LP |
894 | if (r > 0) /* Transaction got restarted... */ |
895 | return; | |
896 | ||
547973de LP |
897 | /* All our auxiliary DNSSEC transactions are complete now. Try |
898 | * to validate our RRset now. */ | |
899 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
900 | if (r == -EBADMSG) { |
901 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
902 | return; | |
903 | } | |
7cc6ed7b LP |
904 | if (r < 0) |
905 | goto fail; | |
547973de | 906 | |
b652d4a2 LP |
907 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
908 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
909 | |
910 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
911 | * that works. */ | |
912 | ||
913 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { | |
914 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
915 | dns_transaction_retry(t, true); | |
916 | return; | |
917 | } | |
918 | ||
919 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
920 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
921 | return; | |
922 | } | |
923 | ||
019036a4 | 924 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
925 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
926 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
927 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
928 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
929 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
930 | return; | |
931 | } | |
932 | ||
1e02e182 LP |
933 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
934 | dns_server_warn_downgrade(t->server); | |
935 | ||
547973de LP |
936 | dns_transaction_cache_answer(t); |
937 | ||
938 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
939 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
940 | else | |
3bbdc31d | 941 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
942 | |
943 | return; | |
944 | ||
945 | fail: | |
fd8a3017 | 946 | dns_transaction_complete_errno(t, r); |
547973de LP |
947 | } |
948 | ||
eac7cda2 LP |
949 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
950 | int r; | |
951 | ||
952 | assert(t); | |
953 | ||
954 | /* Checks whether the answer is positive, i.e. either a direct | |
955 | * answer to the question, or a CNAME/DNAME for it */ | |
956 | ||
42df9532 | 957 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), flags); |
eac7cda2 LP |
958 | if (r != 0) |
959 | return r; | |
960 | ||
42df9532 | 961 | r = dns_answer_find_cname_or_dname(t->answer, dns_transaction_key(t), NULL, flags); |
eac7cda2 LP |
962 | if (r != 0) |
963 | return r; | |
964 | ||
965 | return false; | |
966 | } | |
967 | ||
968 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
969 | int r; | |
970 | ||
971 | assert(t); | |
972 | ||
973 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
974 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
975 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
976 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
977 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
978 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
979 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
980 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
981 | * incomplete CNAME/DNAME chain. | |
982 | * | |
983 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
984 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
985 | * lookup. */ | |
986 | ||
987 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
988 | return 0; | |
989 | ||
990 | r = dns_transaction_has_positive_answer(t, NULL); | |
991 | if (r <= 0) | |
992 | return r; | |
993 | ||
994 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
995 | return 0; | |
996 | } | |
997 | ||
43fc4baa | 998 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p, bool encrypted) { |
ec2c5e43 LP |
999 | int r; |
1000 | ||
1001 | assert(t); | |
1002 | assert(p); | |
9df3ba6c TG |
1003 | assert(t->scope); |
1004 | assert(t->scope->manager); | |
ec2c5e43 | 1005 | |
5a7e41a3 LP |
1006 | if (t->state != DNS_TRANSACTION_PENDING) |
1007 | return; | |
1008 | ||
ec2c5e43 LP |
1009 | /* Note that this call might invalidate the query. Callers |
1010 | * should hence not attempt to access the query or transaction | |
1011 | * after calling this function. */ | |
1012 | ||
11833205 ZJS |
1013 | log_debug("Processing incoming packet on transaction %" PRIu16" (rcode=%s).", |
1014 | t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); | |
b5efcf29 | 1015 | |
106784eb | 1016 | switch (t->scope->protocol) { |
b5efcf29 | 1017 | |
106784eb | 1018 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 1019 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 1020 | |
97ebebbc | 1021 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
1022 | return; |
1023 | ||
1024 | if (p->family != t->scope->family) | |
1025 | return; | |
1026 | ||
1027 | /* Tentative packets are not full responses but still | |
1028 | * useful for identifying uniqueness conflicts during | |
1029 | * probing. */ | |
8b757a38 | 1030 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
1031 | dns_transaction_tentative(t, p); |
1032 | return; | |
1033 | } | |
106784eb DM |
1034 | |
1035 | break; | |
1036 | ||
4e5bf5e1 | 1037 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 1038 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
1039 | |
1040 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
1041 | return; |
1042 | ||
1043 | if (p->family != t->scope->family) | |
1044 | return; | |
1045 | ||
1046 | break; | |
1047 | ||
106784eb | 1048 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
1049 | /* Note that we do not need to verify the |
1050 | * addresses/port numbers of incoming traffic, as we | |
1051 | * invoked connect() on our UDP socket in which case | |
1052 | * the kernel already does the needed verification for | |
1053 | * us. */ | |
106784eb DM |
1054 | break; |
1055 | ||
1056 | default: | |
9c56a6f3 | 1057 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
1058 | } |
1059 | ||
ec2c5e43 LP |
1060 | if (t->received != p) { |
1061 | dns_packet_unref(t->received); | |
1062 | t->received = dns_packet_ref(p); | |
1063 | } | |
1064 | ||
c3bc53e6 LP |
1065 | t->answer_source = DNS_TRANSACTION_NETWORK; |
1066 | ||
ec2c5e43 LP |
1067 | if (p->ipproto == IPPROTO_TCP) { |
1068 | if (DNS_PACKET_TC(p)) { | |
1069 | /* Truncated via TCP? Somebody must be fucking with us */ | |
1070 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1071 | return; | |
1072 | } | |
1073 | ||
1074 | if (DNS_PACKET_ID(p) != t->id) { | |
1075 | /* Not the reply to our query? Somebody must be fucking with us */ | |
1076 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1077 | return; | |
1078 | } | |
1079 | } | |
1080 | ||
9df3ba6c | 1081 | switch (t->scope->protocol) { |
8af5b883 | 1082 | |
9df3ba6c TG |
1083 | case DNS_PROTOCOL_DNS: |
1084 | assert(t->server); | |
1085 | ||
775ae354 LP |
1086 | if (!t->bypass && |
1087 | IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { | |
4e0b8b17 | 1088 | |
8af5b883 | 1089 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 1090 | |
7d581a65 | 1091 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
44db02d0 | 1092 | |
7d581a65 | 1093 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade |
44db02d0 LP |
1094 | * this transaction anymore, but let's see if it might make sense to send the request |
1095 | * to a different DNS server instead. If not let's process the response, and accept the | |
7d581a65 LP |
1096 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate |
1097 | * packet loss, but is not going to give us better rcodes should we actually have | |
1098 | * managed to get them already at UDP level. */ | |
1099 | ||
44db02d0 LP |
1100 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { |
1101 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
1102 | dns_transaction_retry(t, true); | |
1103 | return; | |
1104 | } | |
1105 | ||
1106 | /* Give up, accept the rcode */ | |
d001e0a3 LP |
1107 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
1108 | break; | |
1109 | } | |
1110 | ||
1111 | /* Reduce this feature level by one and try again. */ | |
5d67a7ae IT |
1112 | switch (t->current_feature_level) { |
1113 | case DNS_SERVER_FEATURE_LEVEL_TLS_DO: | |
1114 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN; | |
1115 | break; | |
1116 | case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN + 1: | |
1117 | /* Skip plain TLS when TLS is not supported */ | |
1118 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN - 1; | |
1119 | break; | |
1120 | default: | |
1121 | t->clamp_feature_level = t->current_feature_level - 1; | |
1122 | } | |
d001e0a3 LP |
1123 | |
1124 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
1125 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
1126 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
1127 | ||
1128 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 1129 | return; |
eb08640a LP |
1130 | } |
1131 | ||
1132 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
1133 | /* This server refused our request? If so, try again, use a different server */ | |
1134 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
1135 | dns_transaction_retry(t, true /* pick a new server */); | |
1136 | return; | |
1137 | } | |
1138 | ||
1139 | if (DNS_PACKET_TC(p)) | |
274b8748 | 1140 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
1141 | |
1142 | break; | |
8af5b883 | 1143 | |
9df3ba6c TG |
1144 | case DNS_PROTOCOL_LLMNR: |
1145 | case DNS_PROTOCOL_MDNS: | |
5777c613 | 1146 | dns_scope_packet_received(t->scope, p->timestamp - t->start_usec); |
9df3ba6c | 1147 | break; |
8af5b883 | 1148 | |
9df3ba6c | 1149 | default: |
8af5b883 | 1150 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
1151 | } |
1152 | ||
ec2c5e43 | 1153 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
1154 | |
1155 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
1156 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
1157 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1158 | return; | |
1159 | } | |
1160 | ||
f757cd85 LP |
1161 | log_debug("Reply truncated, retrying via TCP."); |
1162 | ||
ec2c5e43 | 1163 | /* Response was truncated, let's try again with good old TCP */ |
98767d75 | 1164 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 LP |
1165 | if (r == -ESRCH) { |
1166 | /* No servers found? Damn! */ | |
1167 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1168 | return; | |
1169 | } | |
91adc4db LP |
1170 | if (r == -EOPNOTSUPP) { |
1171 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1172 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1173 | return; | |
1174 | } | |
ec2c5e43 | 1175 | if (r < 0) { |
8af5b883 | 1176 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 1177 | * we immediately give up */ |
7cc6ed7b LP |
1178 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1179 | goto fail; | |
ec2c5e43 LP |
1180 | |
1181 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 1182 | dns_transaction_retry(t, true); |
ec2c5e43 | 1183 | } |
2a6658ef LP |
1184 | |
1185 | return; | |
ec2c5e43 LP |
1186 | } |
1187 | ||
de54e62b | 1188 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
1189 | r = dns_packet_extract(p); |
1190 | if (r < 0) { | |
1191 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1192 | return; | |
1193 | } | |
1194 | ||
ed9717fc | 1195 | if (t->server) { |
d001e0a3 LP |
1196 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1197 | * rcode and subsequently downgraded the protocol */ | |
1198 | ||
1199 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1200 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1201 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1202 | ||
1203 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1204 | if (!p->opt) |
1205 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1206 | ||
d001e0a3 | 1207 | /* Report that we successfully received a packet */ |
dbc4661a | 1208 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, p->size); |
ed9717fc | 1209 | } |
de54e62b | 1210 | |
c02cf2f4 LP |
1211 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1212 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1213 | if (r < 0) |
1214 | goto fail; | |
c02cf2f4 LP |
1215 | if (r > 0) /* Transaction got restarted... */ |
1216 | return; | |
1217 | ||
8facd1ce LP |
1218 | /* When dealing with protocols other than mDNS only consider responses with equivalent query section |
1219 | * to the request. For mDNS this check doesn't make sense, because the section 6 of RFC6762 states | |
1220 | * that "Multicast DNS responses MUST NOT contain any questions in the Question Section". */ | |
1221 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
42df9532 | 1222 | r = dns_packet_is_reply_for(p, dns_transaction_key(t)); |
8facd1ce LP |
1223 | if (r < 0) |
1224 | goto fail; | |
1225 | if (r == 0) { | |
1226 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1227 | return; | |
547493c5 | 1228 | } |
8facd1ce | 1229 | } |
29815b6c | 1230 | |
775ae354 LP |
1231 | /* Install the answer as answer to the transaction. We ref the answer twice here: the main `answer` |
1232 | * field is later replaced by the DNSSEC validated subset. The 'answer_auxiliary' field carries the | |
1233 | * original complete record set, including RRSIG and friends. We use this when passing data to | |
1234 | * clients that ask for DNSSEC metadata. */ | |
8facd1ce LP |
1235 | dns_answer_unref(t->answer); |
1236 | t->answer = dns_answer_ref(p->answer); | |
1237 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
1238 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
6f055e43 | 1239 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
43fc4baa | 1240 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_CONFIDENTIAL, encrypted); |
79e24931 | 1241 | |
8facd1ce LP |
1242 | r = dns_transaction_fix_rcode(t); |
1243 | if (r < 0) | |
1244 | goto fail; | |
eac7cda2 | 1245 | |
8facd1ce LP |
1246 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1247 | t->block_gc++; | |
1248 | r = dns_transaction_request_dnssec_keys(t); | |
1249 | t->block_gc--; | |
51e399bc | 1250 | |
8facd1ce LP |
1251 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ |
1252 | if (!dns_transaction_gc(t)) | |
1253 | return; | |
51e399bc | 1254 | |
8facd1ce LP |
1255 | /* Requesting additional keys might have resulted in this transaction to fail, since the auxiliary |
1256 | * request failed for some reason. If so, we are not in pending state anymore, and we should exit | |
1257 | * quickly. */ | |
1258 | if (t->state != DNS_TRANSACTION_PENDING) | |
1259 | return; | |
1260 | if (r < 0) | |
1261 | goto fail; | |
1262 | if (r > 0) { | |
1263 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1264 | t->state = DNS_TRANSACTION_VALIDATING; | |
80710ade | 1265 | dns_transaction_close_connection(t, true); |
8facd1ce LP |
1266 | dns_transaction_stop_timeout(t); |
1267 | return; | |
547493c5 | 1268 | } |
ec2c5e43 | 1269 | |
547973de | 1270 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1271 | return; |
1272 | ||
1273 | fail: | |
fd8a3017 | 1274 | dns_transaction_complete_errno(t, r); |
ec2c5e43 LP |
1275 | } |
1276 | ||
c19ffd9f TG |
1277 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1278 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1279 | DnsTransaction *t = userdata; | |
1280 | int r; | |
1281 | ||
1282 | assert(t); | |
1283 | assert(t->scope); | |
1284 | ||
1285 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
95d2155a | 1286 | if (ERRNO_IS_DISCONNECT(r)) { |
7e1851e3 | 1287 | usec_t usec; |
c19ffd9f | 1288 | |
f731fd5b ZJS |
1289 | /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the |
1290 | * next recvmsg(). Treat this like a lost packet. */ | |
7e1851e3 | 1291 | |
92ec902a | 1292 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1293 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
3da3cdd5 | 1294 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level); |
7e1851e3 | 1295 | |
d68dbb37 LP |
1296 | dns_transaction_close_connection(t, /* use_graveyard = */ false); |
1297 | ||
d001e0a3 | 1298 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1299 | return 0; |
1300 | } | |
1301 | if (r < 0) { | |
fd8a3017 | 1302 | dns_transaction_complete_errno(t, r); |
7e1851e3 LP |
1303 | return 0; |
1304 | } | |
f731fd5b ZJS |
1305 | if (r == 0) |
1306 | /* Spurious wakeup without any data */ | |
1307 | return 0; | |
7e1851e3 LP |
1308 | |
1309 | r = dns_packet_validate_reply(p); | |
1310 | if (r < 0) { | |
1311 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1312 | return 0; | |
1313 | } | |
1314 | if (r == 0) { | |
e09f605e | 1315 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1316 | return 0; |
1317 | } | |
1318 | ||
1319 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1320 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1321 | return 0; |
1322 | } | |
c19ffd9f | 1323 | |
43fc4baa | 1324 | dns_transaction_process_reply(t, p, false); |
c19ffd9f TG |
1325 | return 0; |
1326 | } | |
1327 | ||
49cce12d | 1328 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1329 | int r; |
1330 | ||
1331 | assert(t); | |
c19ffd9f | 1332 | |
519ef046 | 1333 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1334 | |
519ef046 | 1335 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1336 | if (r < 0) |
1337 | return r; | |
c19ffd9f | 1338 | |
49ef064c LP |
1339 | if (manager_server_is_stub(t->scope->manager, t->server)) |
1340 | return -ELOOP; | |
1341 | ||
5d67a7ae | 1342 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) |
7d581a65 | 1343 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1344 | |
775ae354 | 1345 | if (!t->bypass && !dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) |
91adc4db LP |
1346 | return -EOPNOTSUPP; |
1347 | ||
519ef046 LP |
1348 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1349 | int fd; | |
1350 | ||
80710ade LP |
1351 | dns_transaction_close_connection(t, true); |
1352 | ||
1353 | /* Before we allocate a new UDP socket, let's process the graveyard a bit to free some fds */ | |
1354 | manager_socket_graveyard_process(t->scope->manager); | |
c19ffd9f | 1355 | |
da9de738 | 1356 | fd = dns_scope_socket_udp(t->scope, t->server); |
519ef046 LP |
1357 | if (fd < 0) |
1358 | return fd; | |
1359 | ||
1360 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1361 | if (r < 0) { | |
1362 | safe_close(fd); | |
1363 | return r; | |
1364 | } | |
1365 | ||
aa4a9deb | 1366 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1367 | t->dns_udp_fd = fd; |
1368 | } | |
1369 | ||
775ae354 LP |
1370 | if (!t->bypass) { |
1371 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); | |
1372 | if (r < 0) | |
1373 | return r; | |
1374 | } | |
519ef046 | 1375 | } else |
80710ade | 1376 | dns_transaction_close_connection(t, true); |
519ef046 LP |
1377 | |
1378 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1379 | if (r < 0) |
1380 | return r; | |
c19ffd9f | 1381 | |
519ef046 | 1382 | dns_transaction_reset_answer(t); |
be808ea0 | 1383 | |
471d40d9 | 1384 | return 0; |
c19ffd9f TG |
1385 | } |
1386 | ||
ec2c5e43 LP |
1387 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1388 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1389 | |
1390 | assert(s); | |
1391 | assert(t); | |
1392 | ||
ef7ce6df DM |
1393 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1394 | /* Timeout reached? Increase the timeout for the server used */ | |
1395 | switch (t->scope->protocol) { | |
49cce12d | 1396 | |
ef7ce6df DM |
1397 | case DNS_PROTOCOL_DNS: |
1398 | assert(t->server); | |
3da3cdd5 | 1399 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level); |
ef7ce6df | 1400 | break; |
49cce12d | 1401 | |
ef7ce6df DM |
1402 | case DNS_PROTOCOL_LLMNR: |
1403 | case DNS_PROTOCOL_MDNS: | |
1404 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1405 | break; |
49cce12d | 1406 | |
ef7ce6df DM |
1407 | default: |
1408 | assert_not_reached("Invalid DNS protocol."); | |
1409 | } | |
1410 | ||
1411 | if (t->initial_jitter_scheduled) | |
1412 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1413 | } |
1414 | ||
423659ab LP |
1415 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1416 | ||
d001e0a3 | 1417 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1418 | return 0; |
1419 | } | |
1420 | ||
9df3ba6c TG |
1421 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1422 | assert(t); | |
1423 | assert(t->scope); | |
1424 | ||
1425 | switch (t->scope->protocol) { | |
49cce12d | 1426 | |
9df3ba6c | 1427 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1428 | |
1429 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1430 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1431 | * needlessly. */ | |
1432 | if (t->stream) | |
1433 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1434 | ||
dbc4661a | 1435 | return DNS_TIMEOUT_USEC; |
49cce12d | 1436 | |
9df3ba6c | 1437 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1438 | assert(t->n_attempts > 0); |
53fda2bb DR |
1439 | if (t->probing) |
1440 | return MDNS_PROBING_INTERVAL_USEC; | |
1441 | else | |
1442 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1443 | |
11a27c2e | 1444 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1445 | return t->scope->resend_timeout; |
49cce12d | 1446 | |
9df3ba6c TG |
1447 | default: |
1448 | assert_not_reached("Invalid DNS protocol."); | |
1449 | } | |
1450 | } | |
1451 | ||
3f0a7b3a LP |
1452 | static void dns_transaction_randomize_answer(DnsTransaction *t) { |
1453 | int r; | |
1454 | ||
1455 | assert(t); | |
1456 | ||
1457 | /* Randomizes the order of the answer array. This is done for all cached responses, so that we return | |
1458 | * a different order each time. We do this only for DNS traffic, in order to do some minimal, crappy | |
1459 | * load balancing. We don't do this for LLMNR or mDNS, since the order (preferring link-local | |
1460 | * addresses, and such like) might have meaning there, and load balancing is pointless. */ | |
1461 | ||
1462 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1463 | return; | |
1464 | ||
1465 | /* No point in randomizing, if there's just one RR */ | |
1466 | if (dns_answer_size(t->answer) <= 1) | |
1467 | return; | |
1468 | ||
1469 | r = dns_answer_reserve_or_clone(&t->answer, 0); | |
1470 | if (r < 0) /* If this fails, just don't randomize, this is non-essential stuff after all */ | |
1471 | return (void) log_debug_errno(r, "Failed to clone answer record, not randomizing RR order of answer: %m"); | |
1472 | ||
1473 | dns_answer_randomize(t->answer); | |
1474 | } | |
1475 | ||
c842ff24 | 1476 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1477 | int r; |
1478 | ||
1479 | assert(t); | |
1480 | ||
4ea8b443 ZJS |
1481 | /* Returns 0 if dns_transaction_complete() has been called. In that case the transaction and query |
1482 | * candidate objects may have been invalidated and must not be accessed. Returns 1 if the transaction | |
1483 | * has been prepared. */ | |
1484 | ||
f535705a | 1485 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1486 | |
86b112a3 | 1487 | if (!dns_scope_network_good(t->scope)) { |
edbcc1fd LP |
1488 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); |
1489 | return 0; | |
1490 | } | |
1491 | ||
ec2c5e43 | 1492 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
e53b8cc5 ZJS |
1493 | DnsTransactionState result; |
1494 | ||
1495 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) | |
1496 | /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve | |
1497 | * the name. */ | |
1498 | result = DNS_TRANSACTION_NOT_FOUND; | |
1499 | else | |
1500 | result = DNS_TRANSACTION_ATTEMPTS_MAX_REACHED; | |
1501 | ||
1502 | dns_transaction_complete(t, result); | |
ec2c5e43 LP |
1503 | return 0; |
1504 | } | |
1505 | ||
cbe4216d | 1506 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1507 | /* If we already tried via a stream, then we don't |
1508 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1509 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1510 | return 0; | |
1511 | } | |
1512 | ||
1513 | t->n_attempts++; | |
9df3ba6c | 1514 | t->start_usec = ts; |
c61d2b44 LP |
1515 | |
1516 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1517 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1518 | |
0d2cd476 | 1519 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
775ae354 LP |
1520 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
1521 | !FLAGS_SET(t->query_flags, SD_RESOLVED_NO_TRUST_ANCHOR)) { | |
42df9532 | 1522 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, dns_transaction_key(t), &t->answer); |
0d2cd476 LP |
1523 | if (r < 0) |
1524 | return r; | |
1525 | if (r > 0) { | |
1526 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1527 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
43fc4baa | 1528 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED|SD_RESOLVED_CONFIDENTIAL, true); |
0d2cd476 LP |
1529 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1530 | return 0; | |
1531 | } | |
b2b796b8 | 1532 | |
42df9532 LP |
1533 | if (dns_name_is_root(dns_resource_key_name(dns_transaction_key(t))) && |
1534 | dns_transaction_key(t)->type == DNS_TYPE_DS) { | |
b2b796b8 | 1535 | |
775ae354 LP |
1536 | /* Hmm, this is a request for the root DS? A DS RR doesn't exist in the root zone, |
1537 | * and if our trust anchor didn't know it either, this means we cannot do any DNSSEC | |
1538 | * logic anymore. */ | |
b2b796b8 | 1539 | |
1ed8c0fb | 1540 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
775ae354 LP |
1541 | /* We are in downgrade mode. In this case, synthesize an unsigned empty |
1542 | * response, so that the any lookup depending on this one can continue | |
1543 | * assuming there was no DS, and hence the root zone was unsigned. */ | |
b2b796b8 LP |
1544 | |
1545 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1546 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
6f055e43 | 1547 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
43fc4baa | 1548 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_CONFIDENTIAL, true); |
b2b796b8 LP |
1549 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1550 | } else | |
775ae354 LP |
1551 | /* If we are not in downgrade mode, then fail the lookup, because we cannot |
1552 | * reasonably answer it. There might be DS RRs, but we don't know them, and | |
1553 | * the DNS server won't tell them to us (and even if it would, we couldn't | |
1554 | * validate and trust them. */ | |
b2b796b8 LP |
1555 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1556 | ||
1557 | return 0; | |
1558 | } | |
0d2cd476 LP |
1559 | } |
1560 | ||
775ae354 LP |
1561 | /* Check the zone. */ |
1562 | if (!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_ZONE)) { | |
42df9532 | 1563 | r = dns_zone_lookup(&t->scope->zone, dns_transaction_key(t), dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1564 | if (r < 0) |
1565 | return r; | |
1566 | if (r > 0) { | |
ae6a4bbf | 1567 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1568 | t->answer_source = DNS_TRANSACTION_ZONE; |
43fc4baa | 1569 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED|SD_RESOLVED_CONFIDENTIAL, true); |
d746bb3e LP |
1570 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1571 | return 0; | |
1572 | } | |
1573 | } | |
1574 | ||
775ae354 LP |
1575 | /* Check the cache. */ |
1576 | if (!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_CACHE)) { | |
2c27fbca | 1577 | |
775ae354 LP |
1578 | /* Before trying the cache, let's make sure we figured out a server to use. Should this cause |
1579 | * a change of server this might flush the cache. */ | |
5cdb8930 | 1580 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1581 | |
4d926a69 LP |
1582 | /* Let's then prune all outdated entries */ |
1583 | dns_cache_prune(&t->scope->cache); | |
1584 | ||
775ae354 LP |
1585 | r = dns_cache_lookup( |
1586 | &t->scope->cache, | |
1587 | dns_transaction_key(t), | |
1588 | t->query_flags, | |
1589 | &t->answer_rcode, | |
1590 | &t->answer, | |
1591 | &t->received, | |
6f055e43 | 1592 | &t->answer_query_flags, |
775ae354 | 1593 | &t->answer_dnssec_result); |
4d926a69 LP |
1594 | if (r < 0) |
1595 | return r; | |
1596 | if (r > 0) { | |
3f0a7b3a LP |
1597 | dns_transaction_randomize_answer(t); |
1598 | ||
775ae354 LP |
1599 | if (t->bypass && t->scope->protocol == DNS_PROTOCOL_DNS && !t->received) |
1600 | /* When bypass mode is on, do not use cached data unless it came with a full | |
1601 | * packet. */ | |
1602 | dns_transaction_reset_answer(t); | |
1603 | else { | |
1604 | t->answer_source = DNS_TRANSACTION_CACHE; | |
1605 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
1606 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1607 | else | |
1608 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); | |
1609 | return 0; | |
1610 | } | |
4d926a69 | 1611 | } |
ec2c5e43 LP |
1612 | } |
1613 | ||
775ae354 LP |
1614 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_NETWORK)) { |
1615 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SOURCE); | |
1616 | return 0; | |
1617 | } | |
1618 | ||
1effe965 DM |
1619 | return 1; |
1620 | } | |
1621 | ||
0afa57e2 | 1622 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
0afa57e2 | 1623 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
7778dfff | 1624 | bool add_known_answers = false; |
0afa57e2 | 1625 | DnsTransaction *other; |
0d5ee47d DR |
1626 | DnsResourceKey *tkey; |
1627 | _cleanup_set_free_ Set *keys = NULL; | |
0afa57e2 | 1628 | unsigned qdcount; |
0d5ee47d | 1629 | unsigned nscount = 0; |
0afa57e2 DM |
1630 | usec_t ts; |
1631 | int r; | |
1632 | ||
1633 | assert(t); | |
1634 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1635 | ||
e5abebab | 1636 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1637 | t->sent = dns_packet_unref(t->sent); |
1638 | ||
1639 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1640 | if (r < 0) | |
1641 | return r; | |
1642 | ||
42df9532 | 1643 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
0afa57e2 DM |
1644 | if (r < 0) |
1645 | return r; | |
1646 | ||
1647 | qdcount = 1; | |
1648 | ||
42df9532 | 1649 | if (dns_key_is_shared(dns_transaction_key(t))) |
7778dfff DM |
1650 | add_known_answers = true; |
1651 | ||
42df9532 LP |
1652 | if (dns_transaction_key(t)->type == DNS_TYPE_ANY) { |
1653 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(t)); | |
0d5ee47d DR |
1654 | if (r < 0) |
1655 | return r; | |
1656 | } | |
1657 | ||
0afa57e2 DM |
1658 | /* |
1659 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1660 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
5238e957 | 1661 | * in our current scope, and see whether their timing constraints allow them to be sent. |
0afa57e2 DM |
1662 | */ |
1663 | ||
1664 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1665 | ||
1666 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1667 | ||
1668 | /* Skip ourselves */ | |
1669 | if (other == t) | |
1670 | continue; | |
1671 | ||
1672 | if (other->state != DNS_TRANSACTION_PENDING) | |
1673 | continue; | |
1674 | ||
1675 | if (other->next_attempt_after > ts) | |
1676 | continue; | |
1677 | ||
1678 | if (qdcount >= UINT16_MAX) | |
1679 | break; | |
1680 | ||
42df9532 | 1681 | r = dns_packet_append_key(p, dns_transaction_key(other), 0, NULL); |
0afa57e2 DM |
1682 | |
1683 | /* | |
1684 | * If we can't stuff more questions into the packet, just give up. | |
1685 | * One of the 'other' transactions will fire later and take care of the rest. | |
1686 | */ | |
1687 | if (r == -EMSGSIZE) | |
1688 | break; | |
1689 | ||
1690 | if (r < 0) | |
1691 | return r; | |
1692 | ||
c842ff24 | 1693 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1694 | if (r <= 0) |
1695 | continue; | |
1696 | ||
1697 | ts += transaction_get_resend_timeout(other); | |
1698 | ||
1699 | r = sd_event_add_time( | |
1700 | other->scope->manager->event, | |
1701 | &other->timeout_event_source, | |
1702 | clock_boottime_or_monotonic(), | |
1703 | ts, 0, | |
1704 | on_transaction_timeout, other); | |
1705 | if (r < 0) | |
1706 | return r; | |
1707 | ||
ff537038 | 1708 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1709 | |
0afa57e2 DM |
1710 | other->state = DNS_TRANSACTION_PENDING; |
1711 | other->next_attempt_after = ts; | |
1712 | ||
313cefa1 | 1713 | qdcount++; |
7778dfff | 1714 | |
42df9532 | 1715 | if (dns_key_is_shared(dns_transaction_key(other))) |
7778dfff | 1716 | add_known_answers = true; |
0d5ee47d | 1717 | |
42df9532 LP |
1718 | if (dns_transaction_key(other)->type == DNS_TYPE_ANY) { |
1719 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(other)); | |
0d5ee47d DR |
1720 | if (r < 0) |
1721 | return r; | |
1722 | } | |
0afa57e2 DM |
1723 | } |
1724 | ||
1725 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1726 | |
7778dfff DM |
1727 | /* Append known answer section if we're asking for any shared record */ |
1728 | if (add_known_answers) { | |
1729 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1730 | if (r < 0) | |
1731 | return r; | |
1732 | } | |
1733 | ||
90e74a66 | 1734 | SET_FOREACH(tkey, keys) { |
0d5ee47d DR |
1735 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
1736 | bool tentative; | |
1737 | ||
1738 | r = dns_zone_lookup(&t->scope->zone, tkey, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1739 | if (r < 0) | |
1740 | return r; | |
1741 | ||
6f76e68a | 1742 | r = dns_packet_append_answer(p, answer, &nscount); |
0d5ee47d DR |
1743 | if (r < 0) |
1744 | return r; | |
0d5ee47d DR |
1745 | } |
1746 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1747 | ||
1cc6c93a | 1748 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1749 | |
1750 | return 0; | |
1751 | } | |
1752 | ||
1753 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1754 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1755 | int r; | |
1756 | ||
1757 | assert(t); | |
1758 | ||
1759 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1760 | return dns_transaction_make_packet_mdns(t); | |
1761 | ||
1762 | if (t->sent) | |
1763 | return 0; | |
1764 | ||
775ae354 LP |
1765 | if (t->bypass && t->bypass->protocol == t->scope->protocol) { |
1766 | /* If bypass logic is enabled and the protocol if the original packet and our scope match, | |
1767 | * take the original packet, copy it, and patch in our new ID */ | |
1768 | r = dns_packet_dup(&p, t->bypass); | |
1769 | if (r < 0) | |
1770 | return r; | |
1771 | } else { | |
1772 | r = dns_packet_new_query( | |
1773 | &p, t->scope->protocol, | |
1774 | /* min_alloc_dsize = */ 0, | |
1775 | /* dnssec_cd = */ !FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) && | |
1776 | t->scope->dnssec_mode != DNSSEC_NO); | |
1777 | if (r < 0) | |
1778 | return r; | |
0afa57e2 | 1779 | |
775ae354 LP |
1780 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
1781 | if (r < 0) | |
1782 | return r; | |
1783 | ||
1784 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1785 | } | |
0afa57e2 | 1786 | |
0afa57e2 DM |
1787 | DNS_PACKET_HEADER(p)->id = t->id; |
1788 | ||
1cc6c93a | 1789 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1790 | return 0; |
1791 | } | |
1792 | ||
1effe965 DM |
1793 | int dns_transaction_go(DnsTransaction *t) { |
1794 | usec_t ts; | |
1795 | int r; | |
202b76ae | 1796 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1797 | |
1798 | assert(t); | |
1799 | ||
4ea8b443 ZJS |
1800 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has |
1801 | * finished now. In the latter case, the transaction and query candidate objects must not be accessed. | |
1802 | */ | |
5278bbfe | 1803 | |
1effe965 | 1804 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1805 | |
c842ff24 | 1806 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1807 | if (r <= 0) |
1808 | return r; | |
1809 | ||
775ae354 LP |
1810 | log_debug("%s transaction %" PRIu16 " for <%s> scope %s on %s/%s (validate=%s).", |
1811 | t->bypass ? "Bypass" : "Regular", | |
a5784c49 | 1812 | t->id, |
42df9532 | 1813 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
a5784c49 | 1814 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 1815 | t->scope->link ? t->scope->link->ifname : "*", |
775ae354 LP |
1816 | af_to_name_short(t->scope->family), |
1817 | yes_no(!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE))); | |
1effe965 | 1818 | |
ef7ce6df | 1819 | if (!t->initial_jitter_scheduled && |
3742095b | 1820 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1821 | usec_t jitter, accuracy; |
6e068472 LP |
1822 | |
1823 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1824 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1825 | ||
ef7ce6df | 1826 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1827 | |
1828 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1829 | |
1830 | switch (t->scope->protocol) { | |
519ef046 | 1831 | |
ea12bcc7 DM |
1832 | case DNS_PROTOCOL_LLMNR: |
1833 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1834 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1835 | break; | |
519ef046 | 1836 | |
ea12bcc7 DM |
1837 | case DNS_PROTOCOL_MDNS: |
1838 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1839 | jitter += MDNS_JITTER_MIN_USEC; | |
1840 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1841 | break; | |
1842 | default: | |
1843 | assert_not_reached("bad protocol"); | |
1844 | } | |
6e068472 LP |
1845 | |
1846 | r = sd_event_add_time( | |
1847 | t->scope->manager->event, | |
1848 | &t->timeout_event_source, | |
1849 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1850 | ts + jitter, accuracy, |
6e068472 LP |
1851 | on_transaction_timeout, t); |
1852 | if (r < 0) | |
1853 | return r; | |
1854 | ||
aa4a9deb LP |
1855 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1856 | ||
6e068472 | 1857 | t->n_attempts = 0; |
a9da14e1 | 1858 | t->next_attempt_after = ts; |
6e068472 LP |
1859 | t->state = DNS_TRANSACTION_PENDING; |
1860 | ||
ea12bcc7 | 1861 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
4ea8b443 | 1862 | return 1; |
6e068472 LP |
1863 | } |
1864 | ||
ec2c5e43 LP |
1865 | /* Otherwise, we need to ask the network */ |
1866 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1867 | if (r < 0) |
1868 | return r; | |
1869 | ||
1870 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
42df9532 LP |
1871 | (dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "in-addr.arpa") > 0 || |
1872 | dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1873 | |
1874 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1875 | * always be made via TCP on LLMNR */ | |
98767d75 | 1876 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1877 | } else { |
be808ea0 TG |
1878 | /* Try via UDP, and if that fails due to large size or lack of |
1879 | * support try via TCP */ | |
49cce12d | 1880 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1881 | if (r == -EMSGSIZE) |
1882 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1883 | else if (r == -EAGAIN) |
6c0bacc1 | 1884 | log_debug("Sending query via TCP since UDP isn't supported or DNS-over-TLS is selected."); |
4c701096 | 1885 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
98767d75 | 1886 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1887 | } |
49ef064c LP |
1888 | if (r == -ELOOP) { |
1889 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1890 | return r; | |
1891 | ||
1892 | /* One of our own stub listeners */ | |
1893 | log_debug_errno(r, "Detected that specified DNS server is our own extra listener, switching DNS servers."); | |
1894 | ||
5e8bc852 | 1895 | dns_scope_next_dns_server(t->scope, t->server); |
49ef064c LP |
1896 | |
1897 | if (dns_scope_get_dns_server(t->scope) == t->server) { | |
1898 | log_debug_errno(r, "Still pointing to extra listener after switching DNS servers, refusing operation."); | |
1899 | dns_transaction_complete(t, DNS_TRANSACTION_STUB_LOOP); | |
1900 | return 0; | |
1901 | } | |
be808ea0 | 1902 | |
49ef064c LP |
1903 | return dns_transaction_go(t); |
1904 | } | |
ec2c5e43 LP |
1905 | if (r == -ESRCH) { |
1906 | /* No servers to send this to? */ | |
1907 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1908 | return 0; | |
91adc4db LP |
1909 | } |
1910 | if (r == -EOPNOTSUPP) { | |
1911 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1912 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1913 | return 0; | |
1914 | } | |
95d2155a | 1915 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(r)) { |
e94968ba | 1916 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1917 | * answer this request with this protocol. */ |
1918 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1919 | return 0; | |
1920 | } | |
91adc4db | 1921 | if (r < 0) { |
7cc6ed7b LP |
1922 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1923 | return r; | |
13b551ac | 1924 | |
ec2c5e43 | 1925 | /* Couldn't send? Try immediately again, with a new server */ |
5e8bc852 | 1926 | dns_scope_next_dns_server(t->scope, t->server); |
ec2c5e43 LP |
1927 | |
1928 | return dns_transaction_go(t); | |
1929 | } | |
1930 | ||
a9da14e1 DM |
1931 | ts += transaction_get_resend_timeout(t); |
1932 | ||
9a015429 LP |
1933 | r = sd_event_add_time( |
1934 | t->scope->manager->event, | |
1935 | &t->timeout_event_source, | |
1936 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1937 | ts, 0, |
9a015429 | 1938 | on_transaction_timeout, t); |
ec2c5e43 LP |
1939 | if (r < 0) |
1940 | return r; | |
1941 | ||
aa4a9deb LP |
1942 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1943 | ||
ec2c5e43 | 1944 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1945 | t->next_attempt_after = ts; |
1946 | ||
ec2c5e43 LP |
1947 | return 1; |
1948 | } | |
1949 | ||
f2992dc1 LP |
1950 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1951 | DnsTransaction *n; | |
f2992dc1 LP |
1952 | int r; |
1953 | ||
1954 | assert(t); | |
1955 | assert(aux); | |
1956 | ||
1957 | /* Try to find cyclic dependencies between transaction objects */ | |
1958 | ||
1959 | if (t == aux) | |
1960 | return 1; | |
1961 | ||
90e74a66 | 1962 | SET_FOREACH(n, aux->dnssec_transactions) { |
f2992dc1 LP |
1963 | r = dns_transaction_find_cyclic(t, n); |
1964 | if (r != 0) | |
1965 | return r; | |
1966 | } | |
1967 | ||
3eb6aa00 | 1968 | return 0; |
f2992dc1 LP |
1969 | } |
1970 | ||
547973de | 1971 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
29bd6012 | 1972 | _cleanup_(dns_transaction_gcp) DnsTransaction *aux = NULL; |
547973de LP |
1973 | int r; |
1974 | ||
1975 | assert(t); | |
1976 | assert(ret); | |
1977 | assert(key); | |
1978 | ||
775ae354 | 1979 | aux = dns_scope_find_transaction(t->scope, key, t->query_flags); |
547973de | 1980 | if (!aux) { |
775ae354 | 1981 | r = dns_transaction_new(&aux, t->scope, key, NULL, t->query_flags); |
547973de LP |
1982 | if (r < 0) |
1983 | return r; | |
1984 | } else { | |
1985 | if (set_contains(t->dnssec_transactions, aux)) { | |
1986 | *ret = aux; | |
1987 | return 0; | |
1988 | } | |
f2992dc1 LP |
1989 | |
1990 | r = dns_transaction_find_cyclic(t, aux); | |
1991 | if (r < 0) | |
1992 | return r; | |
1993 | if (r > 0) { | |
202b76ae ZJS |
1994 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1995 | ||
baaa35ad ZJS |
1996 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), |
1997 | "Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1998 | aux->id, | |
42df9532 | 1999 | dns_resource_key_to_string(dns_transaction_key(t), s, sizeof s), |
baaa35ad | 2000 | t->id, |
42df9532 | 2001 | dns_resource_key_to_string(dns_transaction_key(aux), saux, sizeof saux)); |
f2992dc1 | 2002 | } |
547973de LP |
2003 | } |
2004 | ||
35aa04e9 LP |
2005 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); |
2006 | if (r < 0) | |
29bd6012 | 2007 | return r; |
547973de | 2008 | |
de7fef4b | 2009 | r = set_ensure_put(&t->dnssec_transactions, NULL, aux); |
547973de | 2010 | if (r < 0) |
a75cb4e2 | 2011 | return r; |
547973de | 2012 | |
de7fef4b | 2013 | r = set_ensure_put(&aux->notify_transactions, NULL, t); |
547973de LP |
2014 | if (r < 0) { |
2015 | (void) set_remove(t->dnssec_transactions, aux); | |
29bd6012 | 2016 | return r; |
547973de LP |
2017 | } |
2018 | ||
29bd6012 | 2019 | *ret = TAKE_PTR(aux); |
547973de | 2020 | return 1; |
547973de LP |
2021 | } |
2022 | ||
2023 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
2024 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
2025 | DnsTransaction *aux; | |
2026 | int r; | |
2027 | ||
2028 | assert(t); | |
2029 | assert(key); | |
2030 | ||
2031 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 2032 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
2033 | if (r < 0) |
2034 | return r; | |
2035 | if (r > 0) { | |
2036 | r = dns_answer_extend(&t->validated_keys, a); | |
2037 | if (r < 0) | |
2038 | return r; | |
2039 | ||
2040 | return 0; | |
2041 | } | |
2042 | ||
2043 | /* This didn't work, ask for it via the network/cache then. */ | |
2044 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
2045 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
2046 | return 0; | |
547973de LP |
2047 | if (r < 0) |
2048 | return r; | |
2049 | ||
2050 | if (aux->state == DNS_TRANSACTION_NULL) { | |
2051 | r = dns_transaction_go(aux); | |
2052 | if (r < 0) | |
2053 | return r; | |
2054 | } | |
2055 | ||
f2992dc1 | 2056 | return 1; |
547973de LP |
2057 | } |
2058 | ||
8a516214 LP |
2059 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
2060 | int r; | |
2061 | ||
2062 | assert(t); | |
2063 | ||
c629ff58 | 2064 | /* Check whether the specified name is in the NTA |
8a516214 LP |
2065 | * database, either in the global one, or the link-local |
2066 | * one. */ | |
2067 | ||
2068 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
2069 | if (r != 0) | |
2070 | return r; | |
2071 | ||
2072 | if (!t->scope->link) | |
2073 | return 0; | |
2074 | ||
7e8a93b7 | 2075 | return link_negative_trust_anchor_lookup(t->scope->link, name); |
8a516214 LP |
2076 | } |
2077 | ||
105e1512 LP |
2078 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
2079 | int r; | |
2080 | ||
2081 | assert(t); | |
2082 | ||
2083 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
2084 | * RRs to prove it */ | |
2085 | ||
2086 | r = dns_transaction_has_positive_answer(t, NULL); | |
2087 | if (r < 0) | |
2088 | return r; | |
2089 | if (r > 0) | |
2090 | return false; | |
2091 | ||
8e54f5d9 LP |
2092 | /* Is this key explicitly listed as a negative trust anchor? |
2093 | * If so, it's nothing we need to care about */ | |
42df9532 | 2094 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
2095 | if (r < 0) |
2096 | return r; | |
2097 | if (r > 0) | |
2098 | return false; | |
2099 | ||
105e1512 LP |
2100 | /* The answer does not contain any RRs that match to the |
2101 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
2102 | * included. If not, the answer is unsigned. */ | |
2103 | ||
2104 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
2105 | if (r < 0) | |
2106 | return r; | |
2107 | if (r > 0) | |
2108 | return false; | |
2109 | ||
2110 | return true; | |
2111 | } | |
2112 | ||
2113 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
2114 | int r; | |
2115 | ||
2116 | assert(t); | |
2117 | assert(rr); | |
2118 | ||
2119 | /* Check if the specified RR is the "primary" response, | |
2120 | * i.e. either matches the question precisely or is a | |
4cb94977 | 2121 | * CNAME/DNAME for it. */ |
105e1512 | 2122 | |
42df9532 | 2123 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
2124 | if (r != 0) |
2125 | return r; | |
2126 | ||
42df9532 | 2127 | return dns_resource_key_match_cname_or_dname(dns_transaction_key(t), rr->key, NULL); |
105e1512 LP |
2128 | } |
2129 | ||
92ec902a LP |
2130 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
2131 | assert(t); | |
2132 | ||
2133 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
2134 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
2135 | ||
2136 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
2137 | return false; | |
2138 | ||
2139 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
2140 | * be supported, hence return true. */ | |
2141 | if (!t->server) | |
2142 | return true; | |
2143 | ||
d001e0a3 LP |
2144 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
2145 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
2146 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
2147 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
2148 | |
2149 | return dns_server_dnssec_supported(t->server); | |
2150 | } | |
2151 | ||
2152 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
2153 | DnsTransaction *dt; | |
92ec902a LP |
2154 | |
2155 | assert(t); | |
2156 | ||
2157 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
2158 | ||
2159 | if (!dns_transaction_dnssec_supported(t)) | |
2160 | return false; | |
2161 | ||
90e74a66 | 2162 | SET_FOREACH(dt, t->dnssec_transactions) |
92ec902a LP |
2163 | if (!dns_transaction_dnssec_supported(dt)) |
2164 | return false; | |
2165 | ||
2166 | return true; | |
2167 | } | |
2168 | ||
547973de LP |
2169 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
2170 | DnsResourceRecord *rr; | |
105e1512 | 2171 | |
547973de LP |
2172 | int r; |
2173 | ||
2174 | assert(t); | |
2175 | ||
105e1512 LP |
2176 | /* |
2177 | * Retrieve all auxiliary RRs for the answer we got, so that | |
2178 | * we can verify signatures or prove that RRs are rightfully | |
2179 | * unsigned. Specifically: | |
2180 | * | |
2181 | * - For RRSIG we get the matching DNSKEY | |
2182 | * - For DNSKEY we get the matching DS | |
2183 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 2184 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 2185 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
2186 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
2187 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
2188 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
2189 | */ | |
2190 | ||
775ae354 | 2191 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) || t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 2192 | return 0; |
92ec902a LP |
2193 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
2194 | return 0; /* We only need to validate stuff from the network */ | |
2195 | if (!dns_transaction_dnssec_supported(t)) | |
5238e957 | 2196 | return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */ |
b652d4a2 | 2197 | |
547973de LP |
2198 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2199 | ||
105e1512 LP |
2200 | if (dns_type_is_pseudo(rr->key->type)) |
2201 | continue; | |
2202 | ||
8e54f5d9 | 2203 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 2204 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2205 | if (r < 0) |
2206 | return r; | |
2207 | if (r > 0) | |
2208 | continue; | |
2209 | ||
547973de LP |
2210 | switch (rr->key->type) { |
2211 | ||
2212 | case DNS_TYPE_RRSIG: { | |
2213 | /* For each RRSIG we request the matching DNSKEY */ | |
2214 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
2215 | ||
2216 | /* If this RRSIG is about a DNSKEY RR and the | |
2217 | * signer is the same as the owner, then we | |
2218 | * already have the DNSKEY, and we don't have | |
2219 | * to look for more. */ | |
2220 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 2221 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
2222 | if (r < 0) |
2223 | return r; | |
2224 | if (r > 0) | |
2225 | continue; | |
2226 | } | |
2227 | ||
105e1512 LP |
2228 | /* If the signer is not a parent of our |
2229 | * original query, then this is about an | |
2230 | * auxiliary RRset, but not anything we asked | |
2231 | * for. In this case we aren't interested, | |
2232 | * because we don't want to request additional | |
2233 | * RRs for stuff we didn't really ask for, and | |
2234 | * also to avoid request loops, where | |
2235 | * additional RRs from one transaction result | |
5238e957 | 2236 | * in another transaction whose additional RRs |
105e1512 LP |
2237 | * point back to the original transaction, and |
2238 | * we deadlock. */ | |
42df9532 | 2239 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), rr->rrsig.signer); |
547973de LP |
2240 | if (r < 0) |
2241 | return r; | |
2242 | if (r == 0) | |
2243 | continue; | |
2244 | ||
2245 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2246 | if (!dnskey) | |
2247 | return -ENOMEM; | |
2248 | ||
1c02e7ba ZJS |
2249 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2250 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2251 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2252 | if (r < 0) | |
2253 | return r; | |
2254 | break; | |
2255 | } | |
2256 | ||
2257 | case DNS_TYPE_DNSKEY: { | |
2258 | /* For each DNSKEY we request the matching DS */ | |
2259 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2260 | ||
105e1512 LP |
2261 | /* If the DNSKEY we are looking at is not for |
2262 | * zone we are interested in, nor any of its | |
2263 | * parents, we aren't interested, and don't | |
2264 | * request it. After all, we don't want to end | |
2265 | * up in request loops, and want to keep | |
2266 | * additional traffic down. */ | |
2267 | ||
42df9532 | 2268 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2269 | if (r < 0) |
2270 | return r; | |
2271 | if (r == 0) | |
2272 | continue; | |
2273 | ||
1c02e7ba | 2274 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2275 | if (!ds) |
2276 | return -ENOMEM; | |
2277 | ||
1c02e7ba ZJS |
2278 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2279 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2280 | r = dns_transaction_request_dnssec_rr(t, ds); |
2281 | if (r < 0) | |
2282 | return r; | |
547973de | 2283 | |
105e1512 LP |
2284 | break; |
2285 | } | |
2286 | ||
105e1512 LP |
2287 | case DNS_TYPE_SOA: |
2288 | case DNS_TYPE_NS: { | |
2289 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2290 | ||
2291 | /* For an unsigned SOA or NS, try to acquire | |
2292 | * the matching DS RR, as we are at a zone cut | |
2293 | * then, and whether a DS exists tells us | |
2294 | * whether the zone is signed. Do so only if | |
2295 | * this RR matches our original question, | |
2296 | * however. */ | |
2297 | ||
42df9532 | 2298 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
2299 | if (r < 0) |
2300 | return r; | |
6993d264 LP |
2301 | if (r == 0) { |
2302 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
d51c4fca | 2303 | * a negative reply, and we need the SOA RR's TTL in order to cache a negative entry? |
6993d264 LP |
2304 | * If so, we need to validate it, too. */ |
2305 | ||
42df9532 | 2306 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), NULL); |
6993d264 LP |
2307 | if (r < 0) |
2308 | return r; | |
2309 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2310 | * it. */ | |
2311 | continue; | |
d5acaa51 LP |
2312 | |
2313 | /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of | |
2314 | * what we are looking for, otherwise there's no value in it for us. */ | |
42df9532 | 2315 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
d5acaa51 LP |
2316 | if (r < 0) |
2317 | return r; | |
2318 | if (r == 0) | |
2319 | continue; | |
6993d264 | 2320 | } |
105e1512 LP |
2321 | |
2322 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2323 | if (r < 0) | |
2324 | return r; | |
2325 | if (r > 0) | |
2326 | continue; | |
2327 | ||
1c02e7ba | 2328 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2329 | if (!ds) |
2330 | return -ENOMEM; | |
2331 | ||
1c02e7ba ZJS |
2332 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2333 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2334 | r = dns_transaction_request_dnssec_rr(t, ds); |
2335 | if (r < 0) | |
2336 | return r; | |
2337 | ||
2338 | break; | |
105e1512 LP |
2339 | } |
2340 | ||
b63fca62 | 2341 | case DNS_TYPE_DS: |
105e1512 LP |
2342 | case DNS_TYPE_CNAME: |
2343 | case DNS_TYPE_DNAME: { | |
2344 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2345 | const char *name; | |
2346 | ||
2347 | /* CNAMEs and DNAMEs cannot be located at a | |
2348 | * zone apex, hence ask for the parent SOA for | |
2349 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2350 | * apex. But do all that only if this is | |
2351 | * actually a response to our original | |
b63fca62 LP |
2352 | * question. |
2353 | * | |
2354 | * Similar for DS RRs, which are signed when | |
2355 | * the parent SOA is signed. */ | |
105e1512 LP |
2356 | |
2357 | r = dns_transaction_is_primary_response(t, rr); | |
2358 | if (r < 0) | |
2359 | return r; | |
2360 | if (r == 0) | |
2361 | continue; | |
2362 | ||
2363 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2364 | if (r < 0) | |
2365 | return r; | |
2366 | if (r > 0) | |
2367 | continue; | |
2368 | ||
43e6779a LP |
2369 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2370 | if (r < 0) | |
2371 | return r; | |
2372 | if (r > 0) | |
2373 | continue; | |
2374 | ||
1c02e7ba | 2375 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2376 | r = dns_name_parent(&name); |
2377 | if (r < 0) | |
2378 | return r; | |
2379 | if (r == 0) | |
2380 | continue; | |
2381 | ||
2382 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2383 | if (!soa) | |
2384 | return -ENOMEM; | |
2385 | ||
1c02e7ba ZJS |
2386 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2387 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2388 | r = dns_transaction_request_dnssec_rr(t, soa); |
2389 | if (r < 0) | |
2390 | return r; | |
2391 | ||
2392 | break; | |
2393 | } | |
2394 | ||
2395 | default: { | |
2396 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2397 | ||
b63fca62 LP |
2398 | /* For other unsigned RRsets (including |
2399 | * NSEC/NSEC3!), look for proof the zone is | |
2400 | * unsigned, by requesting the SOA RR of the | |
2401 | * zone. However, do so only if they are | |
2402 | * directly relevant to our original | |
105e1512 LP |
2403 | * question. */ |
2404 | ||
2405 | r = dns_transaction_is_primary_response(t, rr); | |
2406 | if (r < 0) | |
2407 | return r; | |
2408 | if (r == 0) | |
2409 | continue; | |
2410 | ||
2411 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2412 | if (r < 0) | |
2413 | return r; | |
2414 | if (r > 0) | |
2415 | continue; | |
2416 | ||
1c02e7ba | 2417 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2418 | if (!soa) |
2419 | return -ENOMEM; | |
2420 | ||
1c02e7ba ZJS |
2421 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2422 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2423 | r = dns_transaction_request_dnssec_rr(t, soa); |
2424 | if (r < 0) | |
2425 | return r; | |
2426 | break; | |
547973de LP |
2427 | }} |
2428 | } | |
2429 | ||
105e1512 LP |
2430 | /* Above, we requested everything necessary to validate what |
2431 | * we got. Now, let's request what we need to validate what we | |
2432 | * didn't get... */ | |
2433 | ||
2434 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2435 | if (r < 0) | |
2436 | return r; | |
2437 | if (r > 0) { | |
2438 | const char *name; | |
4bbc06cc | 2439 | uint16_t type = 0; |
105e1512 | 2440 | |
42df9532 | 2441 | name = dns_resource_key_name(dns_transaction_key(t)); |
105e1512 | 2442 | |
4bbc06cc LP |
2443 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2444 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2445 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2446 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2447 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2448 | * to see if that is signed. */ | |
105e1512 | 2449 | |
42df9532 | 2450 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2451 | r = dns_name_parent(&name); |
4bbc06cc LP |
2452 | if (r > 0) { |
2453 | type = DNS_TYPE_SOA; | |
6d72da2f | 2454 | log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", |
42df9532 | 2455 | name, t->id, dns_resource_key_name(dns_transaction_key(t))); |
4bbc06cc | 2456 | } else |
105e1512 | 2457 | name = NULL; |
4bbc06cc | 2458 | |
42df9532 | 2459 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { |
4bbc06cc LP |
2460 | |
2461 | type = DNS_TYPE_DS; | |
6d72da2f LP |
2462 | log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", |
2463 | name, t->id, name); | |
4bbc06cc LP |
2464 | |
2465 | } else { | |
2466 | type = DNS_TYPE_SOA; | |
6d72da2f LP |
2467 | log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2468 | name, t->id, name); | |
4bbc06cc | 2469 | } |
105e1512 LP |
2470 | |
2471 | if (name) { | |
2472 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2473 | ||
42df9532 | 2474 | soa = dns_resource_key_new(dns_transaction_key(t)->class, type, name); |
105e1512 LP |
2475 | if (!soa) |
2476 | return -ENOMEM; | |
2477 | ||
2478 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2479 | if (r < 0) | |
2480 | return r; | |
2481 | } | |
2482 | } | |
2483 | ||
2484 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2485 | } |
2486 | ||
2487 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2488 | assert(t); |
547973de LP |
2489 | assert(source); |
2490 | ||
942eb2e7 LP |
2491 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2492 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2493 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2494 | |
942eb2e7 LP |
2495 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2496 | dns_transaction_process_dnssec(t); | |
547973de LP |
2497 | } |
2498 | ||
105e1512 | 2499 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
04617bf8 LP |
2500 | DnsAnswerItem *item; |
2501 | int r; | |
105e1512 LP |
2502 | |
2503 | assert(t); | |
2504 | ||
2505 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2506 | * RRs from the list of validated keys to the list of | |
2507 | * validated keys. */ | |
2508 | ||
04617bf8 | 2509 | DNS_ANSWER_FOREACH_ITEM(item, t->answer) { |
105e1512 | 2510 | |
04617bf8 | 2511 | r = dnssec_verify_dnskey_by_ds_search(item->rr, t->validated_keys); |
105e1512 LP |
2512 | if (r < 0) |
2513 | return r; | |
2514 | if (r == 0) | |
2515 | continue; | |
2516 | ||
2517 | /* If so, the DNSKEY is validated too. */ | |
04617bf8 | 2518 | r = dns_answer_add_extend(&t->validated_keys, item->rr, item->ifindex, item->flags|DNS_ANSWER_AUTHENTICATED, item->rrsig); |
105e1512 LP |
2519 | if (r < 0) |
2520 | return r; | |
2521 | } | |
2522 | ||
2523 | return 0; | |
2524 | } | |
2525 | ||
2526 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2527 | int r; |
2528 | ||
2529 | assert(t); | |
2530 | assert(rr); | |
2531 | ||
105e1512 LP |
2532 | /* Checks if the RR we are looking for must be signed with an |
2533 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2534 | |
b652d4a2 | 2535 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2536 | return false; |
56352fe9 | 2537 | |
105e1512 LP |
2538 | if (dns_type_is_pseudo(rr->key->type)) |
2539 | return -EINVAL; | |
56352fe9 | 2540 | |
1c02e7ba | 2541 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2542 | if (r < 0) |
2543 | return r; | |
2544 | if (r > 0) | |
2545 | return false; | |
2546 | ||
105e1512 | 2547 | switch (rr->key->type) { |
56352fe9 | 2548 | |
105e1512 LP |
2549 | case DNS_TYPE_RRSIG: |
2550 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2551 | return false; | |
2552 | ||
2553 | case DNS_TYPE_SOA: | |
2554 | case DNS_TYPE_NS: { | |
2555 | DnsTransaction *dt; | |
105e1512 | 2556 | |
b63fca62 | 2557 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 | 2558 | |
90e74a66 | 2559 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2560 | |
42df9532 | 2561 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2562 | continue; |
42df9532 | 2563 | if (dns_transaction_key(dt)->type != DNS_TYPE_DS) |
105e1512 LP |
2564 | continue; |
2565 | ||
42df9532 | 2566 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2567 | if (r < 0) |
2568 | return r; | |
2569 | if (r == 0) | |
2570 | continue; | |
2571 | ||
2572 | /* We found a DS transactions for the SOA/NS | |
2573 | * RRs we are looking at. If it discovered signed DS | |
2574 | * RRs, then we need to be signed, too. */ | |
2575 | ||
6f055e43 | 2576 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
097a2517 | 2577 | return false; |
105e1512 | 2578 | |
42df9532 | 2579 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
105e1512 LP |
2580 | } |
2581 | ||
2582 | /* We found nothing that proves this is safe to leave | |
2583 | * this unauthenticated, hence ask inist on | |
2584 | * authentication. */ | |
2585 | return true; | |
2586 | } | |
2587 | ||
b63fca62 | 2588 | case DNS_TYPE_DS: |
105e1512 LP |
2589 | case DNS_TYPE_CNAME: |
2590 | case DNS_TYPE_DNAME: { | |
2591 | const char *parent = NULL; | |
2592 | DnsTransaction *dt; | |
105e1512 | 2593 | |
b63fca62 LP |
2594 | /* |
2595 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2596 | * | |
2597 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2598 | */ | |
105e1512 | 2599 | |
90e74a66 | 2600 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2601 | |
42df9532 | 2602 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2603 | continue; |
42df9532 | 2604 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2605 | continue; |
2606 | ||
2607 | if (!parent) { | |
1c02e7ba | 2608 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2609 | r = dns_name_parent(&parent); |
2610 | if (r < 0) | |
2611 | return r; | |
2612 | if (r == 0) { | |
b63fca62 LP |
2613 | if (rr->key->type == DNS_TYPE_DS) |
2614 | return true; | |
2615 | ||
105e1512 | 2616 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
baaa35ad ZJS |
2617 | return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), |
2618 | "Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
105e1512 LP |
2619 | } |
2620 | } | |
2621 | ||
42df9532 | 2622 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), parent); |
105e1512 LP |
2623 | if (r < 0) |
2624 | return r; | |
2625 | if (r == 0) | |
2626 | continue; | |
2627 | ||
6f055e43 | 2628 | return FLAGS_SET(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED); |
105e1512 LP |
2629 | } |
2630 | ||
2631 | return true; | |
2632 | } | |
2633 | ||
2634 | default: { | |
2635 | DnsTransaction *dt; | |
105e1512 | 2636 | |
b63fca62 | 2637 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 | 2638 | |
90e74a66 | 2639 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2640 | |
42df9532 | 2641 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2642 | continue; |
42df9532 | 2643 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2644 | continue; |
2645 | ||
42df9532 | 2646 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2647 | if (r < 0) |
2648 | return r; | |
2649 | if (r == 0) | |
2650 | continue; | |
2651 | ||
6f055e43 LP |
2652 | /* We found the transaction that was supposed to find the SOA RR for us. It was |
2653 | * successful, but found no RR for us. This means we are not at a zone cut. In this | |
2654 | * case, we require authentication if the SOA lookup was authenticated too. */ | |
2655 | return FLAGS_SET(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED); | |
105e1512 LP |
2656 | } |
2657 | ||
2658 | return true; | |
2659 | }} | |
56352fe9 LP |
2660 | } |
2661 | ||
d33b6cf3 LP |
2662 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2663 | DnsTransaction *dt; | |
2664 | const char *tld; | |
d33b6cf3 LP |
2665 | int r; |
2666 | ||
2667 | /* If DNSSEC downgrade mode is on, checks whether the | |
2668 | * specified RR is one level below a TLD we have proven not to | |
2669 | * exist. In such a case we assume that this is a private | |
2670 | * domain, and permit it. | |
2671 | * | |
2672 | * This detects cases like the Fritz!Box router networks. Each | |
2673 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2674 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2675 | * are served by the router itself, while requests for the | |
2676 | * "box" domain will result in NXDOMAIN. | |
2677 | * | |
2678 | * Note that this logic is unable to detect cases where a | |
2679 | * router serves a private DNS zone directly under | |
2680 | * non-existing TLD. In such a case we cannot detect whether | |
2681 | * the TLD is supposed to exist or not, as all requests we | |
2682 | * make for it will be answered by the router's zone, and not | |
2683 | * by the root zone. */ | |
2684 | ||
2685 | assert(t); | |
2686 | ||
2687 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2688 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2689 | ||
1c02e7ba | 2690 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2691 | r = dns_name_parent(&tld); |
2692 | if (r < 0) | |
2693 | return r; | |
2694 | if (r == 0) | |
2695 | return false; /* Already the root domain */ | |
2696 | ||
2697 | if (!dns_name_is_single_label(tld)) | |
2698 | return false; | |
2699 | ||
90e74a66 | 2700 | SET_FOREACH(dt, t->dnssec_transactions) { |
d33b6cf3 | 2701 | |
42df9532 | 2702 | if (dns_transaction_key(dt)->class != key->class) |
d33b6cf3 LP |
2703 | continue; |
2704 | ||
42df9532 | 2705 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), tld); |
d33b6cf3 LP |
2706 | if (r < 0) |
2707 | return r; | |
2708 | if (r == 0) | |
2709 | continue; | |
2710 | ||
2711 | /* We found an auxiliary lookup we did for the TLD. If | |
2712 | * that returned with NXDOMAIN, we know the TLD didn't | |
2713 | * exist, and hence this might be a private zone. */ | |
2714 | ||
2715 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2716 | } | |
2717 | ||
2718 | return false; | |
2719 | } | |
2720 | ||
105e1512 | 2721 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2722 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2723 | DnsTransaction *dt; |
2724 | const char *name; | |
4bbc06cc | 2725 | uint16_t type = 0; |
105e1512 | 2726 | int r; |
56352fe9 LP |
2727 | |
2728 | assert(t); | |
2729 | ||
105e1512 LP |
2730 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2731 | * this negative reply */ | |
56352fe9 | 2732 | |
b652d4a2 | 2733 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2734 | return false; |
56352fe9 | 2735 | |
42df9532 | 2736 | if (dns_type_is_pseudo(dns_transaction_key(t)->type)) |
105e1512 LP |
2737 | return -EINVAL; |
2738 | ||
42df9532 | 2739 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
2740 | if (r < 0) |
2741 | return r; | |
2742 | if (r > 0) | |
2743 | return false; | |
2744 | ||
42df9532 | 2745 | r = dns_transaction_in_private_tld(t, dns_transaction_key(t)); |
d33b6cf3 LP |
2746 | if (r < 0) |
2747 | return r; | |
2748 | if (r > 0) { | |
2749 | /* The lookup is from a TLD that is proven not to | |
2750 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2751 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2752 | |
202b76ae | 2753 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
42df9532 | 2754 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
d33b6cf3 LP |
2755 | return false; |
2756 | } | |
2757 | ||
42df9532 | 2758 | name = dns_resource_key_name(dns_transaction_key(t)); |
105e1512 | 2759 | |
42df9532 | 2760 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2761 | |
4bbc06cc LP |
2762 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2763 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2764 | |
2765 | r = dns_name_parent(&name); | |
56352fe9 LP |
2766 | if (r < 0) |
2767 | return r; | |
2768 | if (r == 0) | |
105e1512 | 2769 | return true; |
4bbc06cc LP |
2770 | |
2771 | type = DNS_TYPE_SOA; | |
2772 | ||
42df9532 | 2773 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) |
4bbc06cc LP |
2774 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ |
2775 | type = DNS_TYPE_DS; | |
2776 | else | |
2777 | /* For all other negative replies, check for the SOA lookup */ | |
2778 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2779 | |
2780 | /* For all other RRs we check the SOA on the same level to see | |
2781 | * if it's signed. */ | |
2782 | ||
90e74a66 | 2783 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2784 | |
42df9532 | 2785 | if (dns_transaction_key(dt)->class != dns_transaction_key(t)->class) |
105e1512 | 2786 | continue; |
42df9532 | 2787 | if (dns_transaction_key(dt)->type != type) |
56352fe9 LP |
2788 | continue; |
2789 | ||
42df9532 | 2790 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), name); |
56352fe9 LP |
2791 | if (r < 0) |
2792 | return r; | |
105e1512 LP |
2793 | if (r == 0) |
2794 | continue; | |
2795 | ||
6f055e43 | 2796 | return FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED); |
56352fe9 LP |
2797 | } |
2798 | ||
105e1512 LP |
2799 | /* If in doubt, require NSEC/NSEC3 */ |
2800 | return true; | |
56352fe9 LP |
2801 | } |
2802 | ||
94aa7071 LP |
2803 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2804 | DnsResourceRecord *rrsig; | |
2805 | bool found = false; | |
2806 | int r; | |
2807 | ||
2808 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2809 | * the specified RRset is authenticated (i.e. has a matching | |
2810 | * DS RR). */ | |
2811 | ||
1c02e7ba | 2812 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2813 | if (r < 0) |
2814 | return r; | |
2815 | if (r > 0) | |
2816 | return false; | |
2817 | ||
94aa7071 LP |
2818 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2819 | DnsTransaction *dt; | |
94aa7071 LP |
2820 | |
2821 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2822 | if (r < 0) | |
2823 | return r; | |
2824 | if (r == 0) | |
2825 | continue; | |
2826 | ||
90e74a66 | 2827 | SET_FOREACH(dt, t->dnssec_transactions) { |
94aa7071 | 2828 | |
42df9532 | 2829 | if (dns_transaction_key(dt)->class != rr->key->class) |
94aa7071 LP |
2830 | continue; |
2831 | ||
42df9532 | 2832 | if (dns_transaction_key(dt)->type == DNS_TYPE_DNSKEY) { |
94aa7071 | 2833 | |
42df9532 | 2834 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
2835 | if (r < 0) |
2836 | return r; | |
2837 | if (r == 0) | |
2838 | continue; | |
2839 | ||
6f055e43 LP |
2840 | /* OK, we found an auxiliary DNSKEY lookup. If that lookup is authenticated, |
2841 | * report this. */ | |
94aa7071 | 2842 | |
6f055e43 | 2843 | if (FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
94aa7071 LP |
2844 | return true; |
2845 | ||
2846 | found = true; | |
2847 | ||
42df9532 | 2848 | } else if (dns_transaction_key(dt)->type == DNS_TYPE_DS) { |
94aa7071 | 2849 | |
42df9532 | 2850 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
2851 | if (r < 0) |
2852 | return r; | |
2853 | if (r == 0) | |
2854 | continue; | |
2855 | ||
6f055e43 LP |
2856 | /* OK, we found an auxiliary DS lookup. If that lookup is authenticated and |
2857 | * non-zero, we won! */ | |
94aa7071 | 2858 | |
6f055e43 | 2859 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
94aa7071 LP |
2860 | return false; |
2861 | ||
42df9532 | 2862 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
94aa7071 LP |
2863 | } |
2864 | } | |
2865 | } | |
2866 | ||
2867 | return found ? false : -ENXIO; | |
2868 | } | |
2869 | ||
b652d4a2 LP |
2870 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2871 | assert(t); | |
2872 | assert(rr); | |
2873 | ||
2874 | /* We know that the root domain is signed, hence if it appears | |
2875 | * not to be signed, there's a problem with the DNS server */ | |
2876 | ||
2877 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2878 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2879 | } |
2880 | ||
0f87f3e8 LP |
2881 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2882 | DnsResourceRecord *rr; | |
2883 | int r; | |
2884 | ||
2885 | assert(t); | |
2886 | ||
2887 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2888 | * for a key from our trust anchor. Note that we don't care | |
2889 | * whether the DNSKEY can be authenticated or not. It's | |
2890 | * sufficient if it is self-signed. */ | |
2891 | ||
2892 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2893 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2894 | if (r < 0) |
2895 | return r; | |
2896 | } | |
2897 | ||
2898 | return 0; | |
2899 | } | |
2900 | ||
c9c72065 LP |
2901 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2902 | bool changed; | |
2903 | int r; | |
2904 | ||
2905 | assert(t); | |
2906 | ||
2907 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2908 | * our trust anchors database considers revoked. */ | |
2909 | ||
2910 | do { | |
2911 | DnsResourceRecord *rr; | |
2912 | ||
2913 | changed = false; | |
2914 | ||
2915 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2916 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2917 | if (r < 0) | |
2918 | return r; | |
2919 | if (r > 0) { | |
2920 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2921 | if (r < 0) | |
2922 | return r; | |
2923 | ||
2924 | assert(r > 0); | |
2925 | changed = true; | |
2926 | break; | |
2927 | } | |
2928 | } | |
2929 | } while (changed); | |
2930 | ||
2931 | return 0; | |
2932 | } | |
2933 | ||
942eb2e7 LP |
2934 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2935 | DnsTransaction *dt; | |
942eb2e7 LP |
2936 | int r; |
2937 | ||
2938 | assert(t); | |
2939 | ||
2940 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2941 | ||
90e74a66 | 2942 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
2943 | |
2944 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2945 | continue; | |
2946 | ||
6f055e43 | 2947 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
942eb2e7 LP |
2948 | continue; |
2949 | ||
2950 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2951 | if (r < 0) | |
2952 | return r; | |
2953 | } | |
2954 | ||
2955 | return 0; | |
2956 | } | |
2957 | ||
c690b20a ZJS |
2958 | typedef enum { |
2959 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2960 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2961 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2962 | } Phase; | |
2963 | ||
2964 | static int dnssec_validate_records( | |
2965 | DnsTransaction *t, | |
2966 | Phase phase, | |
2967 | bool *have_nsec, | |
2968 | DnsAnswer **validated) { | |
2969 | ||
547973de | 2970 | DnsResourceRecord *rr; |
56352fe9 | 2971 | int r; |
547973de | 2972 | |
c690b20a | 2973 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2974 | |
c690b20a ZJS |
2975 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2976 | DnsResourceRecord *rrsig = NULL; | |
2977 | DnssecResult result; | |
547973de | 2978 | |
c690b20a ZJS |
2979 | switch (rr->key->type) { |
2980 | case DNS_TYPE_RRSIG: | |
2981 | continue; | |
547973de | 2982 | |
c690b20a ZJS |
2983 | case DNS_TYPE_DNSKEY: |
2984 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2985 | if (phase == DNSSEC_PHASE_NSEC) | |
2986 | continue; | |
2987 | break; | |
547973de | 2988 | |
c690b20a ZJS |
2989 | case DNS_TYPE_NSEC: |
2990 | case DNS_TYPE_NSEC3: | |
2991 | *have_nsec = true; | |
547973de | 2992 | |
c690b20a ZJS |
2993 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2994 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2995 | continue; | |
2996 | break; | |
105e1512 | 2997 | |
c690b20a ZJS |
2998 | default: |
2999 | /* We validate all other RRs only in the ALL phases */ | |
3000 | if (phase != DNSSEC_PHASE_ALL) | |
3001 | continue; | |
3002 | } | |
b652d4a2 | 3003 | |
04617bf8 LP |
3004 | r = dnssec_verify_rrset_search( |
3005 | t->answer, | |
3006 | rr->key, | |
3007 | t->validated_keys, | |
3008 | USEC_INFINITY, | |
3009 | &result, | |
3010 | &rrsig); | |
c690b20a ZJS |
3011 | if (r < 0) |
3012 | return r; | |
547973de | 3013 | |
c690b20a | 3014 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 3015 | |
c690b20a | 3016 | if (result == DNSSEC_VALIDATED) { |
04617bf8 | 3017 | assert(rrsig); |
942eb2e7 | 3018 | |
c690b20a ZJS |
3019 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
3020 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
3021 | * the set of validated keys for this transaction. */ | |
547973de | 3022 | |
04617bf8 | 3023 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED, rrsig); |
c690b20a ZJS |
3024 | if (r < 0) |
3025 | return r; | |
c9c72065 | 3026 | |
c690b20a ZJS |
3027 | /* Some of the DNSKEYs we just added might already have been revoked, |
3028 | * remove them again in that case. */ | |
3029 | r = dns_transaction_invalidate_revoked_keys(t); | |
3030 | if (r < 0) | |
3031 | return r; | |
3032 | } | |
547973de | 3033 | |
04617bf8 LP |
3034 | /* Add the validated RRset to the new list of validated RRsets, and remove it from |
3035 | * the unvalidated RRsets. We mark the RRset as authenticated and cacheable. */ | |
3036 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE, rrsig); | |
c690b20a ZJS |
3037 | if (r < 0) |
3038 | return r; | |
547973de | 3039 | |
c690b20a | 3040 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 3041 | |
c690b20a ZJS |
3042 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
3043 | return 1; | |
3044 | } | |
547973de | 3045 | |
c690b20a ZJS |
3046 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
3047 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
3048 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
3049 | if (phase != DNSSEC_PHASE_ALL) | |
3050 | continue; | |
0c7bff0a | 3051 | |
c690b20a ZJS |
3052 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
3053 | bool authenticated = false; | |
3054 | const char *source; | |
0c7bff0a | 3055 | |
04617bf8 LP |
3056 | assert(rrsig); |
3057 | ||
c690b20a | 3058 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 3059 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 3060 | |
c690b20a ZJS |
3061 | /* First step, determine the source of synthesis */ |
3062 | r = dns_resource_record_source(rrsig, &source); | |
3063 | if (r < 0) | |
3064 | return r; | |
0c7bff0a | 3065 | |
c690b20a | 3066 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 3067 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
3068 | source, |
3069 | rrsig->rrsig.signer, | |
3070 | &authenticated); | |
0c7bff0a | 3071 | |
c690b20a ZJS |
3072 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
3073 | if (r == 0) | |
3074 | result = DNSSEC_INVALID; | |
3075 | else { | |
04617bf8 LP |
3076 | r = dns_answer_move_by_key( |
3077 | validated, | |
3078 | &t->answer, | |
3079 | rr->key, | |
3080 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0, | |
3081 | rrsig); | |
c690b20a ZJS |
3082 | if (r < 0) |
3083 | return r; | |
3084 | ||
3085 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
3086 | ||
3087 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
3088 | return 1; | |
0c7bff0a | 3089 | } |
c690b20a | 3090 | } |
0c7bff0a | 3091 | |
c690b20a ZJS |
3092 | if (result == DNSSEC_NO_SIGNATURE) { |
3093 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
3094 | if (r < 0) |
3095 | return r; | |
c690b20a ZJS |
3096 | if (r == 0) { |
3097 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 3098 | * but remember that this is by no means authenticated. */ |
04617bf8 LP |
3099 | r = dns_answer_move_by_key( |
3100 | validated, | |
3101 | &t->answer, | |
3102 | rr->key, | |
3103 | 0, | |
3104 | NULL); | |
c690b20a ZJS |
3105 | if (r < 0) |
3106 | return r; | |
3107 | ||
3108 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
3109 | return 1; | |
3110 | } | |
547973de | 3111 | |
c690b20a ZJS |
3112 | r = dns_transaction_known_signed(t, rr); |
3113 | if (r < 0) | |
3114 | return r; | |
3115 | if (r > 0) { | |
3116 | /* This is an RR we know has to be signed. If it isn't this means | |
3117 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 3118 | |
c690b20a | 3119 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 3120 | |
c690b20a | 3121 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 3122 | |
c690b20a | 3123 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 3124 | |
04617bf8 | 3125 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
c9c72065 LP |
3126 | if (r < 0) |
3127 | return r; | |
547973de | 3128 | |
c690b20a ZJS |
3129 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3130 | return 1; | |
3131 | } | |
a150ff5e | 3132 | |
c690b20a ZJS |
3133 | /* Otherwise, fail */ |
3134 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
3135 | return 0; | |
f3cf586d | 3136 | } |
547973de | 3137 | |
c690b20a ZJS |
3138 | r = dns_transaction_in_private_tld(t, rr->key); |
3139 | if (r < 0) | |
3140 | return r; | |
3141 | if (r > 0) { | |
202b76ae | 3142 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 3143 | |
c690b20a ZJS |
3144 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
3145 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 3146 | |
202b76ae ZJS |
3147 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
3148 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 3149 | |
04617bf8 | 3150 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
0c7bff0a LP |
3151 | if (r < 0) |
3152 | return r; | |
0c7bff0a | 3153 | |
c690b20a ZJS |
3154 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3155 | return 1; | |
3156 | } | |
3157 | } | |
0c7bff0a | 3158 | |
c690b20a ZJS |
3159 | if (IN_SET(result, |
3160 | DNSSEC_MISSING_KEY, | |
3161 | DNSSEC_SIGNATURE_EXPIRED, | |
3162 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 3163 | |
c690b20a ZJS |
3164 | r = dns_transaction_dnskey_authenticated(t, rr); |
3165 | if (r < 0 && r != -ENXIO) | |
3166 | return r; | |
3167 | if (r == 0) { | |
3168 | /* The DNSKEY transaction was not authenticated, this means there's | |
3169 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 3170 | |
04617bf8 | 3171 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
f3cf586d LP |
3172 | if (r < 0) |
3173 | return r; | |
b652d4a2 | 3174 | |
c690b20a ZJS |
3175 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3176 | return 1; | |
3177 | } | |
3178 | } | |
b652d4a2 | 3179 | |
c690b20a ZJS |
3180 | r = dns_transaction_is_primary_response(t, rr); |
3181 | if (r < 0) | |
3182 | return r; | |
3183 | if (r > 0) { | |
3184 | /* Look for a matching DNAME for this CNAME */ | |
3185 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
3186 | if (r < 0) | |
3187 | return r; | |
3188 | if (r == 0) { | |
3189 | /* Also look among the stuff we already validated */ | |
3190 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
3191 | if (r < 0) |
3192 | return r; | |
c690b20a | 3193 | } |
d33b6cf3 | 3194 | |
c690b20a ZJS |
3195 | if (r == 0) { |
3196 | if (IN_SET(result, | |
3197 | DNSSEC_INVALID, | |
3198 | DNSSEC_SIGNATURE_EXPIRED, | |
3199 | DNSSEC_NO_SIGNATURE)) | |
3200 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
3201 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
3202 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
3203 | ||
3204 | /* This is a primary response to our question, and it failed validation. | |
3205 | * That's fatal. */ | |
3206 | t->answer_dnssec_result = result; | |
3207 | return 0; | |
3208 | } | |
d33b6cf3 | 3209 | |
c690b20a ZJS |
3210 | /* This is a primary response, but we do have a DNAME RR |
3211 | * in the RR that can replay this CNAME, hence rely on | |
3212 | * that, and we can remove the CNAME in favour of it. */ | |
3213 | } | |
d33b6cf3 | 3214 | |
c690b20a ZJS |
3215 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
3216 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
3217 | if (r < 0) | |
3218 | return r; | |
d33b6cf3 | 3219 | |
c690b20a ZJS |
3220 | /* We dropped something from the answer, start from the beginning. */ |
3221 | return 1; | |
3222 | } | |
f3cf586d | 3223 | |
c690b20a ZJS |
3224 | return 2; /* Finito. */ |
3225 | } | |
94aa7071 | 3226 | |
c690b20a ZJS |
3227 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
3228 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
3229 | Phase phase; | |
3230 | DnsAnswerFlags flags; | |
3231 | int r; | |
202b76ae | 3232 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 3233 | |
c690b20a | 3234 | assert(t); |
94aa7071 | 3235 | |
775ae354 | 3236 | /* We have now collected all DS and DNSKEY RRs in t->validated_keys, let's see which RRs we can now |
c690b20a | 3237 | * authenticate with that. */ |
94aa7071 | 3238 | |
775ae354 | 3239 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) || t->scope->dnssec_mode == DNSSEC_NO) |
c690b20a | 3240 | return 0; |
a150ff5e | 3241 | |
c690b20a ZJS |
3242 | /* Already validated */ |
3243 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
3244 | return 0; | |
105e1512 | 3245 | |
c690b20a ZJS |
3246 | /* Our own stuff needs no validation */ |
3247 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
3248 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
6f055e43 | 3249 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, true); |
c690b20a ZJS |
3250 | return 0; |
3251 | } | |
a150ff5e | 3252 | |
c690b20a ZJS |
3253 | /* Cached stuff is not affected by validation. */ |
3254 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
3255 | return 0; | |
f3cf586d | 3256 | |
c690b20a ZJS |
3257 | if (!dns_transaction_dnssec_supported_full(t)) { |
3258 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3259 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3260 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3261 | return 0; |
3262 | } | |
f3cf586d | 3263 | |
202b76ae ZJS |
3264 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3265 | t->id, | |
42df9532 | 3266 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
547973de | 3267 | |
c690b20a ZJS |
3268 | /* First, see if this response contains any revoked trust |
3269 | * anchors we care about */ | |
3270 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3271 | if (r < 0) | |
3272 | return r; | |
43e6779a | 3273 | |
c690b20a ZJS |
3274 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3275 | r = dns_transaction_copy_validated(t); | |
3276 | if (r < 0) | |
3277 | return r; | |
43e6779a | 3278 | |
c690b20a ZJS |
3279 | /* Second, see if there are DNSKEYs we already know a |
3280 | * validated DS for. */ | |
3281 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3282 | if (r < 0) | |
3283 | return r; | |
43e6779a | 3284 | |
c690b20a ZJS |
3285 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3286 | * anchor says are revoked. After all we might have marked | |
3287 | * some keys revoked above, but they might still be lingering | |
3288 | * in our validated_keys list. */ | |
3289 | r = dns_transaction_invalidate_revoked_keys(t); | |
3290 | if (r < 0) | |
3291 | return r; | |
f3cf586d | 3292 | |
c690b20a ZJS |
3293 | phase = DNSSEC_PHASE_DNSKEY; |
3294 | for (;;) { | |
3295 | bool have_nsec = false; | |
f3cf586d | 3296 | |
c690b20a ZJS |
3297 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3298 | if (r <= 0) | |
3299 | return r; | |
547973de | 3300 | |
c690b20a ZJS |
3301 | /* Try again as long as we managed to achieve something */ |
3302 | if (r == 1) | |
547973de LP |
3303 | continue; |
3304 | ||
c690b20a | 3305 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3306 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3307 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3308 | continue; |
3309 | } | |
3310 | ||
c690b20a ZJS |
3311 | if (phase != DNSSEC_PHASE_ALL) { |
3312 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3313 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3314 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3315 | continue; |
547973de LP |
3316 | } |
3317 | ||
56352fe9 | 3318 | /* We're done */ |
547973de LP |
3319 | break; |
3320 | } | |
3321 | ||
3322 | dns_answer_unref(t->answer); | |
1cc6c93a | 3323 | t->answer = TAKE_PTR(validated); |
547973de | 3324 | |
72667f08 LP |
3325 | /* At this point the answer only contains validated |
3326 | * RRsets. Now, let's see if it actually answers the question | |
3327 | * we asked. If so, great! If it doesn't, then see if | |
3328 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3329 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3330 | if (r > 0) { |
105e1512 LP |
3331 | /* Yes, it answers the question! */ |
3332 | ||
3333 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3334 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3335 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 | 3336 | t->answer_rcode = DNS_RCODE_SUCCESS; |
6f055e43 | 3337 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, true); |
105e1512 LP |
3338 | } else { |
3339 | /* The answer is not fully authenticated. */ | |
019036a4 | 3340 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3341 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
105e1512 LP |
3342 | } |
3343 | ||
72667f08 LP |
3344 | } else if (r == 0) { |
3345 | DnssecNsecResult nr; | |
ed29bfdc | 3346 | bool authenticated = false; |
72667f08 LP |
3347 | |
3348 | /* Bummer! Let's check NSEC/NSEC3 */ | |
42df9532 | 3349 | r = dnssec_nsec_test(t->answer, dns_transaction_key(t), &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3350 | if (r < 0) |
3351 | return r; | |
3352 | ||
3353 | switch (nr) { | |
3354 | ||
3355 | case DNSSEC_NSEC_NXDOMAIN: | |
3356 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3357 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3358 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3359 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
6f055e43 | 3360 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, authenticated); |
7aa8ce98 | 3361 | |
42df9532 | 3362 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3363 | break; |
3364 | ||
3365 | case DNSSEC_NSEC_NODATA: | |
3366 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3367 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3368 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3369 | t->answer_rcode = DNS_RCODE_SUCCESS; |
6f055e43 | 3370 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, authenticated); |
7aa8ce98 | 3371 | |
42df9532 | 3372 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3373 | break; |
3374 | ||
105e1512 LP |
3375 | case DNSSEC_NSEC_OPTOUT: |
3376 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3377 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3378 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3379 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
7aa8ce98 | 3380 | |
42df9532 | 3381 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3382 | break; |
3383 | ||
72667f08 LP |
3384 | case DNSSEC_NSEC_NO_RR: |
3385 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3386 | |
3387 | r = dns_transaction_requires_nsec(t); | |
3388 | if (r < 0) | |
3389 | return r; | |
7aa8ce98 | 3390 | if (r > 0) { |
019036a4 | 3391 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
42df9532 | 3392 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
7aa8ce98 | 3393 | } else { |
019036a4 | 3394 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3395 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
42df9532 | 3396 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3397 | } |
3398 | ||
3399 | break; | |
3400 | ||
3401 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3402 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3403 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
42df9532 | 3404 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, dns_transaction_key(t)); |
72667f08 LP |
3405 | break; |
3406 | ||
3407 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3408 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3409 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3410 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
42df9532 | 3411 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
72667f08 LP |
3412 | break; |
3413 | ||
3414 | default: | |
3415 | assert_not_reached("Unexpected NSEC result."); | |
3416 | } | |
3417 | } | |
3418 | ||
547973de LP |
3419 | return 1; |
3420 | } | |
3421 | ||
ec2c5e43 LP |
3422 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3423 | [DNS_TRANSACTION_NULL] = "null", | |
3424 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3425 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3426 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3427 | [DNS_TRANSACTION_SUCCESS] = "success", |
3428 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3429 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3430 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3431 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3432 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3433 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3434 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3435 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3436 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3437 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3438 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
775ae354 | 3439 | [DNS_TRANSACTION_NO_SOURCE] = "no-source", |
49ef064c | 3440 | [DNS_TRANSACTION_STUB_LOOP] = "stub-loop", |
ec2c5e43 LP |
3441 | }; |
3442 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3443 | |
3444 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3445 | [DNS_TRANSACTION_NETWORK] = "network", | |
3446 | [DNS_TRANSACTION_CACHE] = "cache", | |
3447 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3448 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3449 | }; |
3450 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |