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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 | 10 | #include "fd-util.h" |
e2341b6b | 11 | #include "glyph-util.h" |
3ffd4af2 | 12 | #include "random-util.h" |
7778dfff | 13 | #include "resolved-dns-cache.h" |
3ffd4af2 | 14 | #include "resolved-dns-transaction.h" |
6016fcb0 | 15 | #include "resolved-dnstls.h" |
aedf00a2 | 16 | #include "resolved-llmnr.h" |
6016fcb0 | 17 | #include "string-table.h" |
5d67a7ae | 18 | |
b214dc0f | 19 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 20 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 21 | |
dbc4661a MCO |
22 | /* After how much time to repeat classic DNS requests */ |
23 | #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX) | |
24 | ||
c61d2b44 LP |
25 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
26 | assert(t); | |
27 | ||
28 | t->received = dns_packet_unref(t->received); | |
29 | t->answer = dns_answer_unref(t->answer); | |
30 | t->answer_rcode = 0; | |
31 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
32 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
6f055e43 | 33 | t->answer_query_flags = 0; |
f5fbe71d | 34 | t->answer_nsec_ttl = UINT32_MAX; |
7cc6ed7b | 35 | t->answer_errno = 0; |
c61d2b44 LP |
36 | } |
37 | ||
c5b4f861 LP |
38 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
39 | DnsTransaction *z; | |
40 | ||
41 | assert(t); | |
42 | ||
43 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
44 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 45 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
46 | dns_transaction_gc(z); |
47 | } | |
48 | } | |
49 | ||
80710ade LP |
50 | static void dns_transaction_close_connection( |
51 | DnsTransaction *t, | |
52 | bool use_graveyard) { /* Set use_graveyard = false when you know the connection is already | |
53 | * dead, for example because you got a connection error back from the | |
54 | * kernel. In that case there's no point in keeping the fd around, | |
55 | * hence don't. */ | |
56 | int r; | |
57 | ||
f32f0e57 LP |
58 | assert(t); |
59 | ||
b30bf55d LP |
60 | if (t->stream) { |
61 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
98767d75 IT |
62 | LIST_REMOVE(transactions_by_stream, t->stream->transactions, t); |
63 | ||
64 | /* Remove packet in case it's still in the queue */ | |
65 | dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent)); | |
66 | ||
b30bf55d LP |
67 | t->stream = dns_stream_unref(t->stream); |
68 | } | |
69 | ||
97935302 | 70 | t->dns_udp_event_source = sd_event_source_disable_unref(t->dns_udp_event_source); |
80710ade LP |
71 | |
72 | /* If we have an UDP socket where we sent a packet, but never received one, then add it to the socket | |
73 | * graveyard, instead of closing it right away. That way it will stick around for a moment longer, | |
74 | * and the reply we might still get from the server will be eaten up instead of resulting in an ICMP | |
75 | * port unreachable error message. */ | |
76 | ||
77 | if (use_graveyard && t->dns_udp_fd >= 0 && t->sent && !t->received) { | |
78 | r = manager_add_socket_to_graveyard(t->scope->manager, t->dns_udp_fd); | |
79 | if (r < 0) | |
80 | log_debug_errno(r, "Failed to add UDP socket to graveyard, closing immediately: %m"); | |
81 | else | |
82 | TAKE_FD(t->dns_udp_fd); | |
83 | } | |
84 | ||
f32f0e57 LP |
85 | t->dns_udp_fd = safe_close(t->dns_udp_fd); |
86 | } | |
87 | ||
f535705a | 88 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
89 | assert(t); |
90 | ||
97935302 | 91 | t->timeout_event_source = sd_event_source_disable_unref(t->timeout_event_source); |
97cc656c LP |
92 | } |
93 | ||
ec2c5e43 | 94 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 95 | DnsQueryCandidate *c; |
ec2c5e43 | 96 | DnsZoneItem *i; |
547973de | 97 | DnsTransaction *z; |
ec2c5e43 LP |
98 | |
99 | if (!t) | |
100 | return NULL; | |
101 | ||
51e399bc LP |
102 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
103 | ||
80710ade | 104 | dns_transaction_close_connection(t, true); |
f535705a | 105 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 106 | |
ec2c5e43 | 107 | dns_packet_unref(t->sent); |
c61d2b44 | 108 | dns_transaction_reset_answer(t); |
ec2c5e43 | 109 | |
8300ba21 | 110 | dns_server_unref(t->server); |
ec2c5e43 LP |
111 | |
112 | if (t->scope) { | |
775ae354 LP |
113 | if (t->key) { |
114 | DnsTransaction *first; | |
115 | ||
116 | first = hashmap_get(t->scope->transactions_by_key, t->key); | |
117 | LIST_REMOVE(transactions_by_key, first, t); | |
118 | if (first) | |
119 | hashmap_replace(t->scope->transactions_by_key, first->key, first); | |
120 | else | |
121 | hashmap_remove(t->scope->transactions_by_key, t->key); | |
122 | } | |
ec2c5e43 | 123 | |
775ae354 | 124 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); |
ec2c5e43 | 125 | |
013668db LP |
126 | if (t->id != 0) |
127 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
128 | } | |
775ae354 | 129 | |
547973de | 130 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 131 | set_remove(c->transactions, t); |
547973de | 132 | set_free(t->notify_query_candidates); |
801ad6a6 | 133 | |
35aa04e9 LP |
134 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
135 | set_remove(c->transactions, t); | |
136 | set_free(t->notify_query_candidates_done); | |
137 | ||
547973de | 138 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 139 | i->probe_transaction = NULL; |
547973de LP |
140 | set_free(t->notify_zone_items); |
141 | ||
35aa04e9 LP |
142 | while ((i = set_steal_first(t->notify_zone_items_done))) |
143 | i->probe_transaction = NULL; | |
144 | set_free(t->notify_zone_items_done); | |
145 | ||
547973de LP |
146 | while ((z = set_steal_first(t->notify_transactions))) |
147 | set_remove(z->dnssec_transactions, t); | |
148 | set_free(t->notify_transactions); | |
149 | ||
35aa04e9 LP |
150 | while ((z = set_steal_first(t->notify_transactions_done))) |
151 | set_remove(z->dnssec_transactions, t); | |
152 | set_free(t->notify_transactions_done); | |
153 | ||
c5b4f861 | 154 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
155 | set_free(t->dnssec_transactions); |
156 | ||
157 | dns_answer_unref(t->validated_keys); | |
97cc656c | 158 | dns_resource_key_unref(t->key); |
775ae354 | 159 | dns_packet_unref(t->bypass); |
97cc656c | 160 | |
6b430fdb | 161 | return mfree(t); |
ec2c5e43 LP |
162 | } |
163 | ||
164 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
165 | ||
1f388301 | 166 | DnsTransaction* dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
167 | assert(t); |
168 | ||
1f388301 ZJS |
169 | /* Returns !NULL if we can't gc yet. */ |
170 | ||
ec2c5e43 | 171 | if (t->block_gc > 0) |
1f388301 | 172 | return t; |
ec2c5e43 | 173 | |
547973de | 174 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 175 | set_isempty(t->notify_query_candidates_done) && |
547973de | 176 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
177 | set_isempty(t->notify_zone_items_done) && |
178 | set_isempty(t->notify_transactions) && | |
1f388301 ZJS |
179 | set_isempty(t->notify_transactions_done)) |
180 | return dns_transaction_free(t); | |
51e399bc | 181 | |
1f388301 | 182 | return t; |
ec2c5e43 LP |
183 | } |
184 | ||
4dd15077 LP |
185 | static uint16_t pick_new_id(Manager *m) { |
186 | uint16_t new_id; | |
187 | ||
4ea8b443 ZJS |
188 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the |
189 | * number of transactions, and it's much lower than the space of IDs. */ | |
4dd15077 LP |
190 | |
191 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
192 | ||
193 | do | |
194 | random_bytes(&new_id, sizeof(new_id)); | |
195 | while (new_id == 0 || | |
196 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
197 | ||
198 | return new_id; | |
199 | } | |
200 | ||
775ae354 LP |
201 | static int key_ok( |
202 | DnsScope *scope, | |
203 | DnsResourceKey *key) { | |
ec2c5e43 | 204 | |
9eae2bf3 | 205 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 206 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 207 | return -EINVAL; |
d0129ddb LP |
208 | if (dns_type_is_obsolete(key->type)) |
209 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
210 | |
211 | /* We only support the IN class */ | |
4c701096 | 212 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
213 | return -EOPNOTSUPP; |
214 | ||
775ae354 LP |
215 | /* Don't allows DNSSEC RRs to be looked up via LLMNR/mDNS. They don't really make sense |
216 | * there, and it speeds up our queries if we refuse this early */ | |
217 | if (scope->protocol != DNS_PROTOCOL_DNS && | |
218 | dns_type_is_dnssec(key->type)) | |
219 | return -EOPNOTSUPP; | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | int dns_transaction_new( | |
225 | DnsTransaction **ret, | |
226 | DnsScope *s, | |
227 | DnsResourceKey *key, | |
228 | DnsPacket *bypass, | |
229 | uint64_t query_flags) { | |
230 | ||
231 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; | |
232 | int r; | |
233 | ||
234 | assert(ret); | |
235 | assert(s); | |
236 | ||
237 | if (key) { | |
238 | assert(!bypass); | |
239 | ||
240 | r = key_ok(s, key); | |
241 | if (r < 0) | |
242 | return r; | |
243 | } else { | |
244 | DnsResourceKey *qk; | |
245 | assert(bypass); | |
246 | ||
247 | r = dns_packet_validate_query(bypass); | |
248 | if (r < 0) | |
249 | return r; | |
250 | ||
251 | DNS_QUESTION_FOREACH(qk, bypass->question) { | |
252 | r = key_ok(s, qk); | |
253 | if (r < 0) | |
254 | return r; | |
255 | } | |
256 | } | |
257 | ||
b214dc0f LP |
258 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
259 | return -EBUSY; | |
260 | ||
d5099efc | 261 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
262 | if (r < 0) |
263 | return r; | |
264 | ||
775ae354 LP |
265 | if (key) { |
266 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); | |
267 | if (r < 0) | |
268 | return r; | |
269 | } | |
da0c630e | 270 | |
1ed31408 | 271 | t = new(DnsTransaction, 1); |
ec2c5e43 LP |
272 | if (!t) |
273 | return -ENOMEM; | |
274 | ||
1ed31408 LP |
275 | *t = (DnsTransaction) { |
276 | .dns_udp_fd = -1, | |
277 | .answer_source = _DNS_TRANSACTION_SOURCE_INVALID, | |
278 | .answer_dnssec_result = _DNSSEC_RESULT_INVALID, | |
f5fbe71d | 279 | .answer_nsec_ttl = UINT32_MAX, |
1ed31408 | 280 | .key = dns_resource_key_ref(key), |
775ae354 LP |
281 | .query_flags = query_flags, |
282 | .bypass = dns_packet_ref(bypass), | |
1ed31408 | 283 | .current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID, |
1ed4e584 LP |
284 | .clamp_feature_level_servfail = _DNS_SERVER_FEATURE_LEVEL_INVALID, |
285 | .clamp_feature_level_nxdomain = _DNS_SERVER_FEATURE_LEVEL_INVALID, | |
1ed31408 LP |
286 | .id = pick_new_id(s->manager), |
287 | }; | |
ec2c5e43 LP |
288 | |
289 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
290 | if (r < 0) { | |
291 | t->id = 0; | |
292 | return r; | |
293 | } | |
294 | ||
775ae354 LP |
295 | if (t->key) { |
296 | DnsTransaction *first; | |
297 | ||
298 | first = hashmap_get(s->transactions_by_key, t->key); | |
299 | LIST_PREPEND(transactions_by_key, first, t); | |
300 | ||
301 | r = hashmap_replace(s->transactions_by_key, first->key, first); | |
302 | if (r < 0) { | |
303 | LIST_REMOVE(transactions_by_key, first, t); | |
304 | return r; | |
305 | } | |
da0c630e LP |
306 | } |
307 | ||
f9ebb22a | 308 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
309 | t->scope = s; |
310 | ||
313cefa1 | 311 | s->manager->n_transactions_total++; |
a150ff5e | 312 | |
ec2c5e43 LP |
313 | if (ret) |
314 | *ret = t; | |
315 | ||
775ae354 | 316 | TAKE_PTR(t); |
ec2c5e43 LP |
317 | return 0; |
318 | } | |
319 | ||
4dd15077 LP |
320 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
321 | uint16_t new_id; | |
322 | assert(t); | |
323 | ||
324 | /* Pick a new ID for this transaction. */ | |
325 | ||
326 | new_id = pick_new_id(t->scope->manager); | |
327 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
328 | ||
329 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
330 | t->id = new_id; | |
331 | ||
332 | /* Make sure we generate a new packet with the new ID */ | |
333 | t->sent = dns_packet_unref(t->sent); | |
334 | } | |
335 | ||
ec2c5e43 | 336 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
202b76ae | 337 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 338 | DnsZoneItem *z; |
ec2c5e43 LP |
339 | |
340 | assert(t); | |
341 | assert(p); | |
94378145 | 342 | assert(t->scope->protocol == DNS_PROTOCOL_LLMNR); |
ec2c5e43 | 343 | |
94378145 | 344 | if (manager_packet_from_local_address(t->scope->manager, p) != 0) |
ec2c5e43 LP |
345 | return; |
346 | ||
a5784c49 LP |
347 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
348 | t->id, | |
42df9532 | 349 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
ec2c5e43 | 350 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 351 | t->scope->link ? t->scope->link->ifname : "*", |
202b76ae | 352 | af_to_name_short(t->scope->family), |
84dbb3fd | 353 | IN_ADDR_TO_STRING(p->family, &p->sender)); |
ec2c5e43 | 354 | |
a4076574 LP |
355 | /* RFC 4795, Section 4.1 says that the peer with the |
356 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
357 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
358 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
359 | return; |
360 | } | |
361 | ||
4d91eec4 | 362 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 363 | |
ec2c5e43 | 364 | t->block_gc++; |
35aa04e9 | 365 | |
547973de | 366 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
367 | /* First, make sure the zone item drops the reference |
368 | * to us */ | |
369 | dns_zone_item_probe_stop(z); | |
370 | ||
371 | /* Secondly, report this as conflict, so that we might | |
372 | * look for a different hostname */ | |
ec2c5e43 | 373 | dns_zone_item_conflict(z); |
3ef64445 | 374 | } |
ec2c5e43 LP |
375 | t->block_gc--; |
376 | ||
377 | dns_transaction_gc(t); | |
378 | } | |
379 | ||
380 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 381 | DnsQueryCandidate *c; |
ec2c5e43 | 382 | DnsZoneItem *z; |
547973de | 383 | DnsTransaction *d; |
7cc6ed7b | 384 | const char *st; |
202b76ae | 385 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
386 | |
387 | assert(t); | |
547973de | 388 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 389 | |
202b76ae | 390 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
42df9532 | 391 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str); |
202b76ae | 392 | |
f61dfddb | 393 | log_struct(LOG_NOTICE, |
2b044526 | 394 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
92663a5e ZJS |
395 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", |
396 | 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. */ | |
1ed4e584 LP |
475 | if (server != t->server) { |
476 | t->clamp_feature_level_servfail = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
477 | t->clamp_feature_level_nxdomain = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
478 | } | |
d001e0a3 | 479 | |
274b8748 | 480 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 481 | |
d001e0a3 | 482 | /* Clamp the feature level if that is requested. */ |
1ed4e584 LP |
483 | if (t->clamp_feature_level_servfail != _DNS_SERVER_FEATURE_LEVEL_INVALID && |
484 | t->current_feature_level > t->clamp_feature_level_servfail) | |
485 | t->current_feature_level = t->clamp_feature_level_servfail; | |
486 | if (t->clamp_feature_level_nxdomain != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
487 | t->current_feature_level > t->clamp_feature_level_nxdomain) | |
488 | t->current_feature_level = t->clamp_feature_level_nxdomain; | |
d001e0a3 LP |
489 | |
490 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
491 | ||
519ef046 LP |
492 | if (server == t->server) |
493 | return 0; | |
494 | ||
495 | dns_server_unref(t->server); | |
496 | t->server = dns_server_ref(server); | |
497 | ||
44db02d0 LP |
498 | t->n_picked_servers ++; |
499 | ||
8aa5afd2 | 500 | log_debug("Using DNS server %s for transaction %u.", strna(dns_server_string_full(t->server)), t->id); |
d001e0a3 | 501 | |
519ef046 LP |
502 | return 1; |
503 | } | |
504 | ||
d001e0a3 | 505 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
506 | int r; |
507 | ||
508 | assert(t); | |
509 | ||
7ef863a7 LP |
510 | /* Retries the transaction as it is, possibly on a different server */ |
511 | ||
ca55fb88 | 512 | if (next_server && t->scope->protocol == DNS_PROTOCOL_DNS) |
7ef863a7 LP |
513 | log_debug("Retrying transaction %" PRIu16 ", after switching servers.", t->id); |
514 | else | |
515 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
8d10d620 LP |
516 | |
517 | /* Before we try again, switch to a new server. */ | |
d001e0a3 | 518 | if (next_server) |
5e8bc852 | 519 | dns_scope_next_dns_server(t->scope, t->server); |
8d10d620 LP |
520 | |
521 | r = dns_transaction_go(t); | |
fd8a3017 LP |
522 | if (r < 0) |
523 | dns_transaction_complete_errno(t, r); | |
8d10d620 LP |
524 | } |
525 | ||
9147b591 LP |
526 | static bool dns_transaction_limited_retry(DnsTransaction *t) { |
527 | assert(t); | |
528 | ||
529 | /* If we haven't tried all different servers yet, let's try again with a different server */ | |
530 | ||
531 | if (t->n_picked_servers >= dns_scope_get_n_dns_servers(t->scope)) | |
532 | return false; | |
533 | ||
534 | dns_transaction_retry(t, /* next_server= */ true); | |
535 | return true; | |
536 | } | |
537 | ||
c02cf2f4 | 538 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
539 | int r; |
540 | ||
c02cf2f4 LP |
541 | assert(t); |
542 | ||
9147b591 LP |
543 | /* Restarts the transaction, under a new ID if the feature level of the server changed since we first |
544 | * tried, without changing DNS server. Returns > 0 if the transaction was restarted, 0 if not. */ | |
5278bbfe | 545 | |
c02cf2f4 LP |
546 | if (!t->server) |
547 | return 0; | |
548 | ||
549 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
550 | return 0; | |
551 | ||
552 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
553 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
554 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
555 | OPT RR or DO bit. One of these cases is documented here, for example: | |
556 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
557 | ||
4dd15077 LP |
558 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
559 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
560 | |
561 | r = dns_transaction_go(t); | |
562 | if (r < 0) | |
563 | return r; | |
564 | ||
565 | return 1; | |
c02cf2f4 LP |
566 | } |
567 | ||
98767d75 IT |
568 | static void on_transaction_stream_error(DnsTransaction *t, int error) { |
569 | assert(t); | |
ec2c5e43 | 570 | |
80710ade | 571 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 572 | |
a1a3f73a | 573 | if (ERRNO_IS_DISCONNECT(error)) { |
0791110f LP |
574 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
575 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
576 | * question on this scope. */ | |
577 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
daab72ea | 578 | return; |
0791110f LP |
579 | } |
580 | ||
d001e0a3 | 581 | dns_transaction_retry(t, true); |
daab72ea | 582 | return; |
ac720200 | 583 | } |
fd8a3017 LP |
584 | if (error != 0) |
585 | dns_transaction_complete_errno(t, error); | |
98767d75 IT |
586 | } |
587 | ||
43fc4baa LP |
588 | static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsStream *s, DnsPacket *p) { |
589 | bool encrypted; | |
590 | ||
98767d75 | 591 | assert(t); |
43fc4baa | 592 | assert(s); |
98767d75 IT |
593 | assert(p); |
594 | ||
43fc4baa LP |
595 | encrypted = s->encrypted; |
596 | ||
80710ade | 597 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 598 | |
a4076574 | 599 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 600 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
601 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
602 | return 0; | |
603 | } | |
604 | ||
605 | dns_scope_check_conflicts(t->scope, p); | |
606 | ||
ec2c5e43 | 607 | t->block_gc++; |
43fc4baa | 608 | dns_transaction_process_reply(t, p, encrypted); |
ec2c5e43 LP |
609 | t->block_gc--; |
610 | ||
519ef046 LP |
611 | /* If the response wasn't useful, then complete the transition |
612 | * now. After all, we are the worst feature set now with TCP | |
613 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
614 | if (t->state == DNS_TRANSACTION_PENDING) |
615 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
616 | else |
617 | dns_transaction_gc(t); | |
ec2c5e43 LP |
618 | |
619 | return 0; | |
620 | } | |
621 | ||
98767d75 | 622 | static int on_stream_complete(DnsStream *s, int error) { |
7172e4ee | 623 | assert(s); |
98767d75 IT |
624 | |
625 | if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) { | |
98767d75 IT |
626 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
627 | ||
628 | if (s->transactions) { | |
97d5d905 LP |
629 | DnsTransaction *t; |
630 | ||
98767d75 | 631 | t = s->transactions; |
3da3cdd5 | 632 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level); |
98767d75 IT |
633 | } |
634 | } | |
635 | ||
03677889 | 636 | if (error != 0) |
80a226b2 | 637 | LIST_FOREACH(transactions_by_stream, t, s->transactions) |
98767d75 | 638 | on_transaction_stream_error(t, error); |
98767d75 | 639 | |
97d5d905 | 640 | return 0; |
98767d75 IT |
641 | } |
642 | ||
624f907e | 643 | static int on_stream_packet(DnsStream *s, DnsPacket *p) { |
98767d75 IT |
644 | DnsTransaction *t; |
645 | ||
aa337a5e | 646 | assert(s); |
624f907e YW |
647 | assert(s->manager); |
648 | assert(p); | |
98767d75 IT |
649 | |
650 | t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); | |
b52eac20 LP |
651 | if (t && t->stream == s) /* Validate that the stream we got this on actually is the stream the |
652 | * transaction was using. */ | |
43fc4baa | 653 | return dns_transaction_on_stream_packet(t, s, p); |
98767d75 | 654 | |
8227cfa1 | 655 | /* Ignore incorrect transaction id as an old transaction can have been canceled. */ |
30f9e0bf | 656 | log_debug("Received unexpected TCP reply packet with id %" PRIu16 ", ignoring.", DNS_PACKET_ID(p)); |
aa337a5e | 657 | return 0; |
98767d75 IT |
658 | } |
659 | ||
da9de738 | 660 | static uint16_t dns_transaction_port(DnsTransaction *t) { |
775ae354 LP |
661 | assert(t); |
662 | ||
da9de738 YW |
663 | if (t->server->port > 0) |
664 | return t->server->port; | |
775ae354 | 665 | |
da9de738 | 666 | return DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53; |
ec962fba LP |
667 | } |
668 | ||
98767d75 | 669 | static int dns_transaction_emit_tcp(DnsTransaction *t) { |
e1158539 | 670 | usec_t stream_timeout_usec = DNS_STREAM_DEFAULT_TIMEOUT_USEC; |
98767d75 | 671 | _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; |
652ba568 | 672 | _cleanup_close_ int fd = -1; |
91ccab1e | 673 | union sockaddr_union sa; |
652ba568 | 674 | DnsStreamType type; |
ec2c5e43 LP |
675 | int r; |
676 | ||
677 | assert(t); | |
775ae354 | 678 | assert(t->sent); |
ec2c5e43 | 679 | |
80710ade | 680 | dns_transaction_close_connection(t, true); |
ec2c5e43 | 681 | |
106784eb | 682 | switch (t->scope->protocol) { |
519ef046 | 683 | |
106784eb | 684 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
685 | r = dns_transaction_pick_server(t); |
686 | if (r < 0) | |
687 | return r; | |
688 | ||
49ef064c LP |
689 | if (manager_server_is_stub(t->scope->manager, t->server)) |
690 | return -ELOOP; | |
691 | ||
775ae354 LP |
692 | if (!t->bypass) { |
693 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) | |
694 | return -EOPNOTSUPP; | |
91adc4db | 695 | |
775ae354 LP |
696 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
697 | if (r < 0) | |
698 | return r; | |
699 | } | |
519ef046 | 700 | |
5d67a7ae | 701 | if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted)) |
98767d75 IT |
702 | s = dns_stream_ref(t->server->stream); |
703 | else | |
da9de738 | 704 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, dns_transaction_port(t), &sa); |
98767d75 | 705 | |
e1158539 LP |
706 | /* Lower timeout in DNS-over-TLS opportunistic mode. In environments where DoT is blocked |
707 | * without ICMP response overly long delays when contacting DoT servers are nasty, in | |
708 | * particular if multiple DNS servers are defined which we try in turn and all are | |
709 | * blocked. Hence, substantially lower the timeout in that case. */ | |
710 | if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) && | |
711 | dns_server_get_dns_over_tls_mode(t->server) == DNS_OVER_TLS_OPPORTUNISTIC) | |
712 | stream_timeout_usec = DNS_STREAM_OPPORTUNISTIC_TLS_TIMEOUT_USEC; | |
713 | ||
652ba568 | 714 | type = DNS_STREAM_LOOKUP; |
106784eb | 715 | break; |
ec2c5e43 | 716 | |
106784eb | 717 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 718 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 719 | if (t->received) |
91ccab1e | 720 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa); |
ec2c5e43 LP |
721 | else { |
722 | union in_addr_union address; | |
a7f7d1bd | 723 | int family = AF_UNSPEC; |
ec2c5e43 LP |
724 | |
725 | /* Otherwise, try to talk to the owner of a | |
726 | * the IP address, in case this is a reverse | |
727 | * PTR lookup */ | |
f52e61da | 728 | |
42df9532 | 729 | r = dns_name_address(dns_resource_key_name(dns_transaction_key(t)), &family, &address); |
ec2c5e43 LP |
730 | if (r < 0) |
731 | return r; | |
732 | if (r == 0) | |
733 | return -EINVAL; | |
9e08a6e0 | 734 | if (family != t->scope->family) |
9318cdd3 | 735 | return -ESRCH; |
ec2c5e43 | 736 | |
91ccab1e | 737 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa); |
ec2c5e43 | 738 | } |
106784eb | 739 | |
652ba568 | 740 | type = DNS_STREAM_LLMNR_SEND; |
106784eb DM |
741 | break; |
742 | ||
743 | default: | |
ec2c5e43 | 744 | return -EAFNOSUPPORT; |
106784eb | 745 | } |
ec2c5e43 | 746 | |
98767d75 IT |
747 | if (!s) { |
748 | if (fd < 0) | |
749 | return fd; | |
ec2c5e43 | 750 | |
18230451 YW |
751 | r = dns_stream_new(t->scope->manager, &s, type, t->scope->protocol, fd, &sa, |
752 | on_stream_packet, on_stream_complete, stream_timeout_usec); | |
98767d75 IT |
753 | if (r < 0) |
754 | return r; | |
755 | ||
756 | fd = -1; | |
757 | ||
56ddbf10 | 758 | #if ENABLE_DNS_OVER_TLS |
199dda9c LP |
759 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
760 | DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) { | |
761 | ||
b02a7e1a | 762 | assert(t->server); |
6016fcb0 | 763 | r = dnstls_stream_connect_tls(s, t->server); |
5d67a7ae IT |
764 | if (r < 0) |
765 | return r; | |
766 | } | |
767 | #endif | |
768 | ||
19feb28f | 769 | if (t->server) { |
904dcaf9 | 770 | dns_server_unref_stream(t->server); |
19feb28f | 771 | s->server = dns_server_ref(t->server); |
8227cfa1 | 772 | t->server->stream = dns_stream_ref(s); |
19feb28f IT |
773 | } |
774 | ||
98767d75 IT |
775 | /* The interface index is difficult to determine if we are |
776 | * connecting to the local host, hence fill this in right away | |
777 | * instead of determining it from the socket */ | |
778 | s->ifindex = dns_scope_ifindex(t->scope); | |
779 | } | |
780 | ||
781 | t->stream = TAKE_PTR(s); | |
782 | LIST_PREPEND(transactions_by_stream, t->stream->transactions, t); | |
ec2c5e43 LP |
783 | |
784 | r = dns_stream_write_packet(t->stream, t->sent); | |
785 | if (r < 0) { | |
80710ade | 786 | dns_transaction_close_connection(t, /* use_graveyard= */ false); |
ec2c5e43 LP |
787 | return r; |
788 | } | |
789 | ||
519ef046 LP |
790 | dns_transaction_reset_answer(t); |
791 | ||
cbe4216d LP |
792 | t->tried_stream = true; |
793 | ||
ec2c5e43 LP |
794 | return 0; |
795 | } | |
796 | ||
547973de | 797 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
798 | assert(t); |
799 | ||
800 | /* For mDNS we cache whenever we get the packet, rather than | |
801 | * in each transaction. */ | |
802 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
803 | return; | |
804 | ||
ceeddf79 | 805 | /* Caching disabled? */ |
37d7a7d9 | 806 | if (t->scope->manager->enable_cache == DNS_CACHE_MODE_NO) |
ceeddf79 MP |
807 | return; |
808 | ||
775ae354 LP |
809 | /* If validation is turned off for this transaction, but DNSSEC is on, then let's not cache this */ |
810 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) && t->scope->dnssec_mode != DNSSEC_NO) | |
811 | return; | |
812 | ||
6d8325f6 PS |
813 | /* Packet from localhost? */ |
814 | if (!t->scope->manager->cache_from_localhost && | |
815 | in_addr_is_localhost(t->received->family, &t->received->sender) != 0) | |
547973de LP |
816 | return; |
817 | ||
547973de | 818 | dns_cache_put(&t->scope->cache, |
37d7a7d9 | 819 | t->scope->manager->enable_cache, |
42df9532 | 820 | dns_transaction_key(t), |
547973de LP |
821 | t->answer_rcode, |
822 | t->answer, | |
775ae354 LP |
823 | DNS_PACKET_CD(t->received) ? t->received : NULL, /* only cache full packets with CD on, |
824 | * since our usecase for caching them | |
825 | * is "bypass" mode which is only | |
826 | * enabled for CD packets. */ | |
6f055e43 | 827 | t->answer_query_flags, |
775ae354 | 828 | t->answer_dnssec_result, |
d3760be0 | 829 | t->answer_nsec_ttl, |
547973de LP |
830 | t->received->family, |
831 | &t->received->sender); | |
832 | } | |
833 | ||
105e1512 LP |
834 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
835 | DnsTransaction *dt; | |
105e1512 LP |
836 | |
837 | assert(t); | |
838 | ||
90e74a66 | 839 | SET_FOREACH(dt, t->dnssec_transactions) |
105e1512 LP |
840 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) |
841 | return true; | |
842 | ||
843 | return false; | |
844 | } | |
845 | ||
942eb2e7 LP |
846 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
847 | DnsTransaction *dt; | |
e30a62bf | 848 | int r; |
942eb2e7 LP |
849 | |
850 | assert(t); | |
851 | ||
852 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
853 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
854 | ||
90e74a66 | 855 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
856 | |
857 | switch (dt->state) { | |
858 | ||
859 | case DNS_TRANSACTION_NULL: | |
860 | case DNS_TRANSACTION_PENDING: | |
861 | case DNS_TRANSACTION_VALIDATING: | |
862 | /* Still ongoing */ | |
863 | return 0; | |
864 | ||
865 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 866 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
0d609349 | 867 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", FORMAT_DNS_RCODE(dt->answer_rcode)); |
942eb2e7 LP |
868 | goto fail; |
869 | } | |
870 | ||
b3c6b00a | 871 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
5238e957 | 872 | * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS |
b3c6b00a LP |
873 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar |
874 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
875 | |
876 | case DNS_TRANSACTION_SUCCESS: | |
877 | /* All good. */ | |
878 | break; | |
879 | ||
880 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
881 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
e30a62bf | 882 | * validation result */ |
942eb2e7 LP |
883 | |
884 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
885 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
886 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
887 | return 0; | |
888 | ||
942eb2e7 LP |
889 | default: |
890 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
891 | goto fail; | |
892 | } | |
893 | } | |
894 | ||
895 | /* All is ready, we can go and validate */ | |
896 | return 1; | |
897 | ||
898 | fail: | |
e30a62bf LP |
899 | /* Some auxiliary DNSSEC transaction failed for some reason. Maybe we learned something about the |
900 | * server due to this failure, and the feature level is now different? Let's see and restart the | |
901 | * transaction if so. If not, let's propagate the auxiliary failure. | |
902 | * | |
903 | * This is particularly relevant if an auxiliary request figured out that DNSSEC doesn't work, and we | |
904 | * are in permissive DNSSEC mode, and thus should restart things without DNSSEC magic. */ | |
905 | r = dns_transaction_maybe_restart(t); | |
906 | if (r < 0) | |
907 | return r; | |
908 | if (r > 0) | |
909 | return 0; /* don't validate just yet, we restarted things */ | |
910 | ||
942eb2e7 LP |
911 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; |
912 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
913 | return 0; | |
914 | } | |
915 | ||
547973de LP |
916 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
917 | int r; | |
918 | ||
919 | assert(t); | |
920 | ||
921 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 922 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
923 | if (r < 0) |
924 | goto fail; | |
942eb2e7 | 925 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
926 | return; |
927 | ||
c02cf2f4 LP |
928 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
929 | * restart the lookup immediately. */ | |
930 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
931 | if (r < 0) |
932 | goto fail; | |
c02cf2f4 LP |
933 | if (r > 0) /* Transaction got restarted... */ |
934 | return; | |
935 | ||
547973de LP |
936 | /* All our auxiliary DNSSEC transactions are complete now. Try |
937 | * to validate our RRset now. */ | |
938 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
939 | if (r == -EBADMSG) { |
940 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
941 | return; | |
942 | } | |
7cc6ed7b LP |
943 | if (r < 0) |
944 | goto fail; | |
547973de | 945 | |
b652d4a2 LP |
946 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
947 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
948 | |
949 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
950 | * that works. */ | |
951 | ||
9147b591 | 952 | if (dns_transaction_limited_retry(t)) |
e82b1132 | 953 | return; |
e82b1132 LP |
954 | |
955 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
956 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
957 | return; | |
958 | } | |
959 | ||
019036a4 | 960 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
961 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
962 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
963 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
964 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
965 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
966 | return; | |
967 | } | |
968 | ||
1e02e182 LP |
969 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
970 | dns_server_warn_downgrade(t->server); | |
971 | ||
547973de LP |
972 | dns_transaction_cache_answer(t); |
973 | ||
974 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
975 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
976 | else | |
3bbdc31d | 977 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
978 | |
979 | return; | |
980 | ||
981 | fail: | |
fd8a3017 | 982 | dns_transaction_complete_errno(t, r); |
547973de LP |
983 | } |
984 | ||
eac7cda2 LP |
985 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
986 | int r; | |
987 | ||
988 | assert(t); | |
989 | ||
990 | /* Checks whether the answer is positive, i.e. either a direct | |
991 | * answer to the question, or a CNAME/DNAME for it */ | |
992 | ||
42df9532 | 993 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), flags); |
eac7cda2 LP |
994 | if (r != 0) |
995 | return r; | |
996 | ||
42df9532 | 997 | r = dns_answer_find_cname_or_dname(t->answer, dns_transaction_key(t), NULL, flags); |
eac7cda2 LP |
998 | if (r != 0) |
999 | return r; | |
1000 | ||
1001 | return false; | |
1002 | } | |
1003 | ||
1004 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
1005 | int r; | |
1006 | ||
1007 | assert(t); | |
1008 | ||
1009 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
1010 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
1011 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
1012 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
1013 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
1014 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
1015 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
1016 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
1017 | * incomplete CNAME/DNAME chain. | |
1018 | * | |
1019 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
1020 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
1021 | * lookup. */ | |
1022 | ||
1023 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
1024 | return 0; | |
1025 | ||
1026 | r = dns_transaction_has_positive_answer(t, NULL); | |
1027 | if (r <= 0) | |
1028 | return r; | |
1029 | ||
1030 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1031 | return 0; | |
1032 | } | |
1033 | ||
43fc4baa | 1034 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p, bool encrypted) { |
acbf761b | 1035 | bool retry_with_tcp = false; |
ec2c5e43 LP |
1036 | int r; |
1037 | ||
1038 | assert(t); | |
1039 | assert(p); | |
9df3ba6c TG |
1040 | assert(t->scope); |
1041 | assert(t->scope->manager); | |
ec2c5e43 | 1042 | |
5a7e41a3 LP |
1043 | if (t->state != DNS_TRANSACTION_PENDING) |
1044 | return; | |
1045 | ||
ec2c5e43 LP |
1046 | /* Note that this call might invalidate the query. Callers |
1047 | * should hence not attempt to access the query or transaction | |
1048 | * after calling this function. */ | |
1049 | ||
f7155840 LP |
1050 | log_debug("Processing incoming packet of size %zu on transaction %" PRIu16" (rcode=%s).", |
1051 | p->size, | |
0d609349 | 1052 | t->id, FORMAT_DNS_RCODE(DNS_PACKET_RCODE(p))); |
b5efcf29 | 1053 | |
106784eb | 1054 | switch (t->scope->protocol) { |
b5efcf29 | 1055 | |
106784eb | 1056 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 1057 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 1058 | |
97ebebbc | 1059 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
1060 | return; |
1061 | ||
1062 | if (p->family != t->scope->family) | |
1063 | return; | |
1064 | ||
1065 | /* Tentative packets are not full responses but still | |
1066 | * useful for identifying uniqueness conflicts during | |
1067 | * probing. */ | |
8b757a38 | 1068 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
1069 | dns_transaction_tentative(t, p); |
1070 | return; | |
1071 | } | |
106784eb DM |
1072 | |
1073 | break; | |
1074 | ||
4e5bf5e1 | 1075 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 1076 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
1077 | |
1078 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
1079 | return; |
1080 | ||
1081 | if (p->family != t->scope->family) | |
1082 | return; | |
1083 | ||
1084 | break; | |
1085 | ||
106784eb | 1086 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
1087 | /* Note that we do not need to verify the |
1088 | * addresses/port numbers of incoming traffic, as we | |
1089 | * invoked connect() on our UDP socket in which case | |
1090 | * the kernel already does the needed verification for | |
1091 | * us. */ | |
106784eb DM |
1092 | break; |
1093 | ||
1094 | default: | |
04499a70 | 1095 | assert_not_reached(); |
ec2c5e43 LP |
1096 | } |
1097 | ||
899e3cda ZJS |
1098 | if (t->received != p) |
1099 | DNS_PACKET_REPLACE(t->received, dns_packet_ref(p)); | |
ec2c5e43 | 1100 | |
c3bc53e6 LP |
1101 | t->answer_source = DNS_TRANSACTION_NETWORK; |
1102 | ||
ec2c5e43 LP |
1103 | if (p->ipproto == IPPROTO_TCP) { |
1104 | if (DNS_PACKET_TC(p)) { | |
1105 | /* Truncated via TCP? Somebody must be fucking with us */ | |
1106 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1107 | return; | |
1108 | } | |
1109 | ||
1110 | if (DNS_PACKET_ID(p) != t->id) { | |
1111 | /* Not the reply to our query? Somebody must be fucking with us */ | |
1112 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1113 | return; | |
1114 | } | |
1115 | } | |
1116 | ||
9df3ba6c | 1117 | switch (t->scope->protocol) { |
8af5b883 | 1118 | |
9df3ba6c TG |
1119 | case DNS_PROTOCOL_DNS: |
1120 | assert(t->server); | |
1121 | ||
775ae354 LP |
1122 | if (!t->bypass && |
1123 | IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { | |
4e0b8b17 | 1124 | |
8af5b883 | 1125 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 1126 | |
7d581a65 | 1127 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
44db02d0 | 1128 | |
7d581a65 | 1129 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade |
44db02d0 LP |
1130 | * this transaction anymore, but let's see if it might make sense to send the request |
1131 | * to a different DNS server instead. If not let's process the response, and accept the | |
7d581a65 LP |
1132 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate |
1133 | * packet loss, but is not going to give us better rcodes should we actually have | |
1134 | * managed to get them already at UDP level. */ | |
1135 | ||
9147b591 | 1136 | if (dns_transaction_limited_retry(t)) |
44db02d0 | 1137 | return; |
44db02d0 LP |
1138 | |
1139 | /* Give up, accept the rcode */ | |
0d609349 | 1140 | log_debug("Server returned error: %s", FORMAT_DNS_RCODE(DNS_PACKET_RCODE(p))); |
d001e0a3 LP |
1141 | break; |
1142 | } | |
1143 | ||
8a33aa19 SS |
1144 | /* SERVFAIL can happen for many reasons and may be transient. |
1145 | * To avoid unnecessary downgrades retry once with the initial level. | |
1146 | * Check for clamp_feature_level_servfail having an invalid value as a sign that this is the | |
1147 | * first attempt to downgrade. If so, clamp to the current value so that the transaction | |
1148 | * is retried without actually downgrading. If the next try also fails we will downgrade by | |
1149 | * hitting the else branch below. */ | |
1150 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_SERVFAIL && | |
1151 | t->clamp_feature_level_servfail < 0) { | |
1152 | t->clamp_feature_level_servfail = t->current_feature_level; | |
1153 | log_debug("Server returned error %s, retrying transaction.", | |
0d609349 | 1154 | FORMAT_DNS_RCODE(DNS_PACKET_RCODE(p))); |
8a33aa19 SS |
1155 | } else { |
1156 | /* Reduce this feature level by one and try again. */ | |
1157 | switch (t->current_feature_level) { | |
1158 | case DNS_SERVER_FEATURE_LEVEL_TLS_DO: | |
1159 | t->clamp_feature_level_servfail = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN; | |
1160 | break; | |
1161 | case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN + 1: | |
1162 | /* Skip plain TLS when TLS is not supported */ | |
1163 | t->clamp_feature_level_servfail = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN - 1; | |
1164 | break; | |
1165 | default: | |
1166 | t->clamp_feature_level_servfail = t->current_feature_level - 1; | |
1167 | } | |
1168 | ||
1169 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
0d609349 | 1170 | FORMAT_DNS_RCODE(DNS_PACKET_RCODE(p)), |
8a33aa19 | 1171 | dns_server_feature_level_to_string(t->clamp_feature_level_servfail)); |
5d67a7ae | 1172 | } |
d001e0a3 | 1173 | |
d001e0a3 | 1174 | dns_transaction_retry(t, false /* use the same server */); |
4e0b8b17 | 1175 | return; |
eb08640a LP |
1176 | } |
1177 | ||
1178 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
1179 | /* This server refused our request? If so, try again, use a different server */ | |
1180 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
9147b591 LP |
1181 | |
1182 | if (dns_transaction_limited_retry(t)) | |
1183 | return; | |
1184 | ||
1185 | break; | |
eb08640a LP |
1186 | } |
1187 | ||
1188 | if (DNS_PACKET_TC(p)) | |
274b8748 | 1189 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
1190 | |
1191 | break; | |
8af5b883 | 1192 | |
9df3ba6c TG |
1193 | case DNS_PROTOCOL_LLMNR: |
1194 | case DNS_PROTOCOL_MDNS: | |
5777c613 | 1195 | dns_scope_packet_received(t->scope, p->timestamp - t->start_usec); |
9df3ba6c | 1196 | break; |
8af5b883 | 1197 | |
9df3ba6c | 1198 | default: |
04499a70 | 1199 | assert_not_reached(); |
9df3ba6c TG |
1200 | } |
1201 | ||
ec2c5e43 | 1202 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
1203 | |
1204 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
1205 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
1206 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1207 | return; | |
1208 | } | |
1209 | ||
acbf761b | 1210 | /* Response was truncated, let's try again with good old TCP */ |
f757cd85 | 1211 | log_debug("Reply truncated, retrying via TCP."); |
acbf761b | 1212 | retry_with_tcp = true; |
f757cd85 | 1213 | |
acbf761b LP |
1214 | } else if (t->scope->protocol == DNS_PROTOCOL_DNS && |
1215 | DNS_PACKET_IS_FRAGMENTED(p)) { | |
1216 | ||
1217 | /* Report the fragment size, so that we downgrade from LARGE to regular EDNS0 if needed */ | |
1218 | if (t->server) | |
1219 | dns_server_packet_udp_fragmented(t->server, dns_packet_size_unfragmented(p)); | |
1220 | ||
1221 | if (t->current_feature_level > DNS_SERVER_FEATURE_LEVEL_UDP) { | |
1222 | /* Packet was fragmented. Let's retry with TCP to avoid fragmentation attack | |
1223 | * issues. (We don't do that on the lowest feature level however, since crappy DNS | |
1224 | * servers often do not implement TCP, hence falling back to TCP on fragmentation is | |
1225 | * counter-productive there.) */ | |
1226 | ||
f7155840 LP |
1227 | log_debug("Reply fragmented, retrying via TCP. (Largest fragment size: %zu; Datagram size: %zu)", |
1228 | p->fragsize, p->size); | |
acbf761b LP |
1229 | retry_with_tcp = true; |
1230 | } | |
1231 | } | |
1232 | ||
1233 | if (retry_with_tcp) { | |
98767d75 | 1234 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 LP |
1235 | if (r == -ESRCH) { |
1236 | /* No servers found? Damn! */ | |
1237 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1238 | return; | |
1239 | } | |
91adc4db LP |
1240 | if (r == -EOPNOTSUPP) { |
1241 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1242 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1243 | return; | |
1244 | } | |
ec2c5e43 | 1245 | if (r < 0) { |
8af5b883 | 1246 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 1247 | * we immediately give up */ |
7cc6ed7b LP |
1248 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1249 | goto fail; | |
ec2c5e43 LP |
1250 | |
1251 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
9147b591 LP |
1252 | if (dns_transaction_limited_retry(t)) |
1253 | return; | |
1254 | ||
1255 | /* No new server to try, give up */ | |
1256 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
ec2c5e43 | 1257 | } |
2a6658ef LP |
1258 | |
1259 | return; | |
ec2c5e43 LP |
1260 | } |
1261 | ||
de54e62b | 1262 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
1263 | r = dns_packet_extract(p); |
1264 | if (r < 0) { | |
2c42a217 LP |
1265 | if (t->server) { |
1266 | dns_server_packet_invalid(t->server, t->current_feature_level); | |
1267 | ||
1268 | r = dns_transaction_maybe_restart(t); | |
1269 | if (r < 0) | |
1270 | goto fail; | |
1271 | if (r > 0) /* Transaction got restarted... */ | |
1272 | return; | |
1273 | } | |
1274 | ||
ec2c5e43 LP |
1275 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
1276 | return; | |
1277 | } | |
1278 | ||
1ed4e584 LP |
1279 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
1280 | !t->bypass && | |
1281 | DNS_PACKET_RCODE(p) == DNS_RCODE_NXDOMAIN && | |
1282 | p->opt && !DNS_PACKET_DO(p) && | |
1283 | DNS_SERVER_FEATURE_LEVEL_IS_EDNS0(t->current_feature_level) && | |
1284 | DNS_SERVER_FEATURE_LEVEL_IS_UDP(t->current_feature_level) && | |
1285 | t->scope->dnssec_mode != DNSSEC_YES) { | |
1286 | ||
1287 | /* Some captive portals are special in that the Aruba/Datavalet hardware will miss | |
1288 | * replacing the packets with the local server IP to point to the authenticated side | |
1289 | * of the network if EDNS0 is enabled. Instead they return NXDOMAIN, with DO bit set | |
1290 | * to zero... nothing to see here, yet respond with the captive portal IP, when using | |
1291 | * the more simple UDP level. | |
1292 | * | |
1293 | * Common portal names that fail like so are: | |
1294 | * secure.datavalet.io | |
1295 | * securelogin.arubanetworks.com | |
1296 | * securelogin.networks.mycompany.com | |
1297 | * | |
1298 | * Thus retry NXDOMAIN RCODES with a lower feature level. | |
1299 | * | |
1300 | * Do not lower the server's tracked feature level, as the captive portal should not | |
1301 | * be lying for the wider internet (e.g. _other_ queries were observed fine with | |
1302 | * EDNS0 on these networks, post auth), i.e. let's just lower the level transaction's | |
1303 | * feature level. | |
1304 | * | |
1305 | * This is reported as https://github.com/dns-violations/dns-violations/blob/master/2018/DVE-2018-0001.md | |
1306 | */ | |
1307 | ||
1308 | t->clamp_feature_level_nxdomain = DNS_SERVER_FEATURE_LEVEL_UDP; | |
1309 | ||
1310 | log_debug("Server returned error %s in EDNS0 mode, retrying transaction with reduced feature level %s (DVE-2018-0001 mitigation)", | |
0d609349 | 1311 | FORMAT_DNS_RCODE(DNS_PACKET_RCODE(p)), |
1ed4e584 LP |
1312 | dns_server_feature_level_to_string(t->clamp_feature_level_nxdomain)); |
1313 | ||
1314 | dns_transaction_retry(t, false /* use the same server */); | |
1315 | return; | |
1316 | } | |
1317 | ||
ed9717fc | 1318 | if (t->server) { |
d001e0a3 LP |
1319 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1320 | * rcode and subsequently downgraded the protocol */ | |
1321 | ||
1322 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1ed4e584 LP |
1323 | t->clamp_feature_level_servfail != _DNS_SERVER_FEATURE_LEVEL_INVALID) |
1324 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level_servfail); | |
d001e0a3 LP |
1325 | |
1326 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1327 | if (!p->opt) |
1328 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1329 | ||
d96275d8 LP |
1330 | /* Report that the server didn't copy our query DO bit from request to response */ |
1331 | if (DNS_PACKET_DO(t->sent) && !DNS_PACKET_DO(t->received)) | |
1332 | dns_server_packet_do_off(t->server, t->current_feature_level); | |
1333 | ||
acbf761b LP |
1334 | /* Report that we successfully received a packet. We keep track of the largest packet |
1335 | * size/fragment size we got. Which is useful for announcing the EDNS(0) packet size we can | |
1336 | * receive to our server. */ | |
1337 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, dns_packet_size_unfragmented(p)); | |
ed9717fc | 1338 | } |
de54e62b | 1339 | |
c02cf2f4 LP |
1340 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1341 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1342 | if (r < 0) |
1343 | goto fail; | |
c02cf2f4 LP |
1344 | if (r > 0) /* Transaction got restarted... */ |
1345 | return; | |
1346 | ||
8facd1ce LP |
1347 | /* When dealing with protocols other than mDNS only consider responses with equivalent query section |
1348 | * to the request. For mDNS this check doesn't make sense, because the section 6 of RFC6762 states | |
1349 | * that "Multicast DNS responses MUST NOT contain any questions in the Question Section". */ | |
1350 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
42df9532 | 1351 | r = dns_packet_is_reply_for(p, dns_transaction_key(t)); |
8facd1ce LP |
1352 | if (r < 0) |
1353 | goto fail; | |
1354 | if (r == 0) { | |
1355 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1356 | return; | |
547493c5 | 1357 | } |
8facd1ce | 1358 | } |
29815b6c | 1359 | |
775ae354 LP |
1360 | /* Install the answer as answer to the transaction. We ref the answer twice here: the main `answer` |
1361 | * field is later replaced by the DNSSEC validated subset. The 'answer_auxiliary' field carries the | |
1362 | * original complete record set, including RRSIG and friends. We use this when passing data to | |
1363 | * clients that ask for DNSSEC metadata. */ | |
1117a960 | 1364 | DNS_ANSWER_REPLACE(t->answer, dns_answer_ref(p->answer)); |
8facd1ce LP |
1365 | t->answer_rcode = DNS_PACKET_RCODE(p); |
1366 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
6f055e43 | 1367 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
43fc4baa | 1368 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_CONFIDENTIAL, encrypted); |
79e24931 | 1369 | |
8facd1ce LP |
1370 | r = dns_transaction_fix_rcode(t); |
1371 | if (r < 0) | |
1372 | goto fail; | |
eac7cda2 | 1373 | |
8facd1ce LP |
1374 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1375 | t->block_gc++; | |
1376 | r = dns_transaction_request_dnssec_keys(t); | |
1377 | t->block_gc--; | |
51e399bc | 1378 | |
8facd1ce LP |
1379 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ |
1380 | if (!dns_transaction_gc(t)) | |
1381 | return; | |
51e399bc | 1382 | |
8facd1ce LP |
1383 | /* Requesting additional keys might have resulted in this transaction to fail, since the auxiliary |
1384 | * request failed for some reason. If so, we are not in pending state anymore, and we should exit | |
1385 | * quickly. */ | |
1386 | if (t->state != DNS_TRANSACTION_PENDING) | |
1387 | return; | |
1388 | if (r < 0) | |
1389 | goto fail; | |
1390 | if (r > 0) { | |
1391 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1392 | t->state = DNS_TRANSACTION_VALIDATING; | |
80710ade | 1393 | dns_transaction_close_connection(t, true); |
8facd1ce LP |
1394 | dns_transaction_stop_timeout(t); |
1395 | return; | |
547493c5 | 1396 | } |
ec2c5e43 | 1397 | |
547973de | 1398 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1399 | return; |
1400 | ||
1401 | fail: | |
fd8a3017 | 1402 | dns_transaction_complete_errno(t, r); |
ec2c5e43 LP |
1403 | } |
1404 | ||
c19ffd9f TG |
1405 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1406 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1407 | DnsTransaction *t = userdata; | |
1408 | int r; | |
1409 | ||
1410 | assert(t); | |
1411 | assert(t->scope); | |
1412 | ||
1413 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
95d2155a | 1414 | if (ERRNO_IS_DISCONNECT(r)) { |
7e1851e3 | 1415 | usec_t usec; |
c19ffd9f | 1416 | |
f731fd5b ZJS |
1417 | /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the |
1418 | * next recvmsg(). Treat this like a lost packet. */ | |
7e1851e3 | 1419 | |
92ec902a | 1420 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
ba4e0427 | 1421 | assert_se(sd_event_now(t->scope->manager->event, CLOCK_BOOTTIME, &usec) >= 0); |
3da3cdd5 | 1422 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level); |
7e1851e3 | 1423 | |
d68dbb37 LP |
1424 | dns_transaction_close_connection(t, /* use_graveyard = */ false); |
1425 | ||
9147b591 LP |
1426 | if (dns_transaction_limited_retry(t)) /* Try a different server */ |
1427 | return 0; | |
1428 | ||
1429 | dns_transaction_complete_errno(t, r); | |
7e1851e3 LP |
1430 | return 0; |
1431 | } | |
1432 | if (r < 0) { | |
fd8a3017 | 1433 | dns_transaction_complete_errno(t, r); |
7e1851e3 LP |
1434 | return 0; |
1435 | } | |
f731fd5b ZJS |
1436 | if (r == 0) |
1437 | /* Spurious wakeup without any data */ | |
1438 | return 0; | |
7e1851e3 LP |
1439 | |
1440 | r = dns_packet_validate_reply(p); | |
1441 | if (r < 0) { | |
1442 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1443 | return 0; | |
1444 | } | |
1445 | if (r == 0) { | |
e09f605e | 1446 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1447 | return 0; |
1448 | } | |
1449 | ||
1450 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1451 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1452 | return 0; |
1453 | } | |
c19ffd9f | 1454 | |
43fc4baa | 1455 | dns_transaction_process_reply(t, p, false); |
c19ffd9f TG |
1456 | return 0; |
1457 | } | |
1458 | ||
49cce12d | 1459 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1460 | int r; |
1461 | ||
1462 | assert(t); | |
c19ffd9f | 1463 | |
519ef046 | 1464 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1465 | |
519ef046 | 1466 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1467 | if (r < 0) |
1468 | return r; | |
c19ffd9f | 1469 | |
49ef064c LP |
1470 | if (manager_server_is_stub(t->scope->manager, t->server)) |
1471 | return -ELOOP; | |
1472 | ||
5d67a7ae | 1473 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) |
7d581a65 | 1474 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1475 | |
775ae354 | 1476 | if (!t->bypass && !dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(dns_transaction_key(t)->type)) |
91adc4db LP |
1477 | return -EOPNOTSUPP; |
1478 | ||
519ef046 LP |
1479 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1480 | int fd; | |
1481 | ||
80710ade LP |
1482 | dns_transaction_close_connection(t, true); |
1483 | ||
1484 | /* Before we allocate a new UDP socket, let's process the graveyard a bit to free some fds */ | |
1485 | manager_socket_graveyard_process(t->scope->manager); | |
c19ffd9f | 1486 | |
da9de738 | 1487 | fd = dns_scope_socket_udp(t->scope, t->server); |
519ef046 LP |
1488 | if (fd < 0) |
1489 | return fd; | |
1490 | ||
1491 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1492 | if (r < 0) { | |
1493 | safe_close(fd); | |
1494 | return r; | |
1495 | } | |
1496 | ||
aa4a9deb | 1497 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1498 | t->dns_udp_fd = fd; |
1499 | } | |
1500 | ||
775ae354 LP |
1501 | if (!t->bypass) { |
1502 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); | |
1503 | if (r < 0) | |
1504 | return r; | |
1505 | } | |
519ef046 | 1506 | } else |
80710ade | 1507 | dns_transaction_close_connection(t, true); |
519ef046 | 1508 | |
d79677ab | 1509 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->server ? t->server->family : AF_UNSPEC, t->sent); |
471d40d9 TG |
1510 | if (r < 0) |
1511 | return r; | |
c19ffd9f | 1512 | |
519ef046 | 1513 | dns_transaction_reset_answer(t); |
be808ea0 | 1514 | |
471d40d9 | 1515 | return 0; |
c19ffd9f TG |
1516 | } |
1517 | ||
ec2c5e43 LP |
1518 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1519 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1520 | |
1521 | assert(s); | |
1522 | assert(t); | |
1523 | ||
213cb4f7 LP |
1524 | if (t->initial_jitter_scheduled && !t->initial_jitter_elapsed) { |
1525 | log_debug("Initial jitter phase for transaction %" PRIu16 " elapsed.", t->id); | |
1526 | t->initial_jitter_elapsed = true; | |
1527 | } else { | |
ef7ce6df DM |
1528 | /* Timeout reached? Increase the timeout for the server used */ |
1529 | switch (t->scope->protocol) { | |
49cce12d | 1530 | |
ef7ce6df DM |
1531 | case DNS_PROTOCOL_DNS: |
1532 | assert(t->server); | |
3da3cdd5 | 1533 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level); |
ef7ce6df | 1534 | break; |
49cce12d | 1535 | |
ef7ce6df DM |
1536 | case DNS_PROTOCOL_LLMNR: |
1537 | case DNS_PROTOCOL_MDNS: | |
1538 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1539 | break; |
49cce12d | 1540 | |
ef7ce6df | 1541 | default: |
04499a70 | 1542 | assert_not_reached(); |
ef7ce6df DM |
1543 | } |
1544 | ||
213cb4f7 | 1545 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
be808ea0 TG |
1546 | } |
1547 | ||
213cb4f7 LP |
1548 | dns_transaction_retry(t, /* next_server= */ true); /* try a different server, but given this means |
1549 | * packet loss, let's do so even if we already | |
1550 | * tried a bunch */ | |
ec2c5e43 LP |
1551 | return 0; |
1552 | } | |
1553 | ||
87b91644 YW |
1554 | static int dns_transaction_setup_timeout( |
1555 | DnsTransaction *t, | |
1556 | usec_t timeout_usec /* relative */, | |
1557 | usec_t next_usec /* CLOCK_BOOTTIME */) { | |
1558 | ||
1559 | int r; | |
1560 | ||
1561 | assert(t); | |
1562 | ||
1563 | dns_transaction_stop_timeout(t); | |
1564 | ||
1565 | r = sd_event_add_time_relative( | |
1566 | t->scope->manager->event, | |
1567 | &t->timeout_event_source, | |
1568 | CLOCK_BOOTTIME, | |
1569 | timeout_usec, 0, | |
1570 | on_transaction_timeout, t); | |
1571 | if (r < 0) | |
1572 | return r; | |
1573 | ||
1574 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); | |
1575 | ||
1576 | t->next_attempt_after = next_usec; | |
1577 | t->state = DNS_TRANSACTION_PENDING; | |
1578 | return 0; | |
1579 | } | |
1580 | ||
9df3ba6c TG |
1581 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1582 | assert(t); | |
1583 | assert(t->scope); | |
1584 | ||
1585 | switch (t->scope->protocol) { | |
49cce12d | 1586 | |
9df3ba6c | 1587 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1588 | |
1589 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1590 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1591 | * needlessly. */ | |
1592 | if (t->stream) | |
1593 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1594 | ||
dbc4661a | 1595 | return DNS_TIMEOUT_USEC; |
49cce12d | 1596 | |
9df3ba6c | 1597 | case DNS_PROTOCOL_MDNS: |
53fda2bb DR |
1598 | if (t->probing) |
1599 | return MDNS_PROBING_INTERVAL_USEC; | |
4b2ceb8a YW |
1600 | |
1601 | /* See RFC 6762 Section 5.1 suggests that timeout should be a few seconds. */ | |
1602 | assert(t->n_attempts > 0); | |
1603 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1604 | |
11a27c2e | 1605 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1606 | return t->scope->resend_timeout; |
49cce12d | 1607 | |
9df3ba6c | 1608 | default: |
04499a70 | 1609 | assert_not_reached(); |
9df3ba6c TG |
1610 | } |
1611 | } | |
1612 | ||
3f0a7b3a LP |
1613 | static void dns_transaction_randomize_answer(DnsTransaction *t) { |
1614 | int r; | |
1615 | ||
1616 | assert(t); | |
1617 | ||
1618 | /* Randomizes the order of the answer array. This is done for all cached responses, so that we return | |
1619 | * a different order each time. We do this only for DNS traffic, in order to do some minimal, crappy | |
1620 | * load balancing. We don't do this for LLMNR or mDNS, since the order (preferring link-local | |
1621 | * addresses, and such like) might have meaning there, and load balancing is pointless. */ | |
1622 | ||
1623 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1624 | return; | |
1625 | ||
1626 | /* No point in randomizing, if there's just one RR */ | |
1627 | if (dns_answer_size(t->answer) <= 1) | |
1628 | return; | |
1629 | ||
1630 | r = dns_answer_reserve_or_clone(&t->answer, 0); | |
1631 | if (r < 0) /* If this fails, just don't randomize, this is non-essential stuff after all */ | |
1632 | return (void) log_debug_errno(r, "Failed to clone answer record, not randomizing RR order of answer: %m"); | |
1633 | ||
1634 | dns_answer_randomize(t->answer); | |
1635 | } | |
1636 | ||
c842ff24 | 1637 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1638 | int r; |
1639 | ||
1640 | assert(t); | |
1641 | ||
4ea8b443 ZJS |
1642 | /* Returns 0 if dns_transaction_complete() has been called. In that case the transaction and query |
1643 | * candidate objects may have been invalidated and must not be accessed. Returns 1 if the transaction | |
1644 | * has been prepared. */ | |
1645 | ||
f535705a | 1646 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1647 | |
86b112a3 | 1648 | if (!dns_scope_network_good(t->scope)) { |
edbcc1fd LP |
1649 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); |
1650 | return 0; | |
1651 | } | |
1652 | ||
c3dbb132 | 1653 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
e53b8cc5 ZJS |
1654 | DnsTransactionState result; |
1655 | ||
1656 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) | |
1657 | /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve | |
1658 | * the name. */ | |
1659 | result = DNS_TRANSACTION_NOT_FOUND; | |
1660 | else | |
1661 | result = DNS_TRANSACTION_ATTEMPTS_MAX_REACHED; | |
1662 | ||
1663 | dns_transaction_complete(t, result); | |
ec2c5e43 LP |
1664 | return 0; |
1665 | } | |
1666 | ||
cbe4216d | 1667 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1668 | /* If we already tried via a stream, then we don't |
1669 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1670 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1671 | return 0; | |
1672 | } | |
1673 | ||
1674 | t->n_attempts++; | |
9df3ba6c | 1675 | t->start_usec = ts; |
c61d2b44 LP |
1676 | |
1677 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1678 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1679 | |
0d2cd476 | 1680 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
775ae354 LP |
1681 | if (t->scope->protocol == DNS_PROTOCOL_DNS && |
1682 | !FLAGS_SET(t->query_flags, SD_RESOLVED_NO_TRUST_ANCHOR)) { | |
42df9532 | 1683 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, dns_transaction_key(t), &t->answer); |
0d2cd476 LP |
1684 | if (r < 0) |
1685 | return r; | |
1686 | if (r > 0) { | |
1687 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1688 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
43fc4baa | 1689 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED|SD_RESOLVED_CONFIDENTIAL, true); |
0d2cd476 LP |
1690 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1691 | return 0; | |
1692 | } | |
b2b796b8 | 1693 | |
42df9532 LP |
1694 | if (dns_name_is_root(dns_resource_key_name(dns_transaction_key(t))) && |
1695 | dns_transaction_key(t)->type == DNS_TYPE_DS) { | |
b2b796b8 | 1696 | |
775ae354 LP |
1697 | /* Hmm, this is a request for the root DS? A DS RR doesn't exist in the root zone, |
1698 | * and if our trust anchor didn't know it either, this means we cannot do any DNSSEC | |
1699 | * logic anymore. */ | |
b2b796b8 | 1700 | |
1ed8c0fb | 1701 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
775ae354 LP |
1702 | /* We are in downgrade mode. In this case, synthesize an unsigned empty |
1703 | * response, so that the any lookup depending on this one can continue | |
1704 | * assuming there was no DS, and hence the root zone was unsigned. */ | |
b2b796b8 LP |
1705 | |
1706 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1707 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
6f055e43 | 1708 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
43fc4baa | 1709 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_CONFIDENTIAL, true); |
b2b796b8 LP |
1710 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1711 | } else | |
775ae354 LP |
1712 | /* If we are not in downgrade mode, then fail the lookup, because we cannot |
1713 | * reasonably answer it. There might be DS RRs, but we don't know them, and | |
1714 | * the DNS server won't tell them to us (and even if it would, we couldn't | |
1715 | * validate and trust them. */ | |
b2b796b8 LP |
1716 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1717 | ||
1718 | return 0; | |
1719 | } | |
0d2cd476 LP |
1720 | } |
1721 | ||
775ae354 LP |
1722 | /* Check the zone. */ |
1723 | if (!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_ZONE)) { | |
42df9532 | 1724 | r = dns_zone_lookup(&t->scope->zone, dns_transaction_key(t), dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1725 | if (r < 0) |
1726 | return r; | |
1727 | if (r > 0) { | |
ae6a4bbf | 1728 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1729 | t->answer_source = DNS_TRANSACTION_ZONE; |
43fc4baa | 1730 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED|SD_RESOLVED_CONFIDENTIAL, true); |
d746bb3e LP |
1731 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1732 | return 0; | |
1733 | } | |
1734 | } | |
1735 | ||
775ae354 LP |
1736 | /* Check the cache. */ |
1737 | if (!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_CACHE)) { | |
2c27fbca | 1738 | |
775ae354 LP |
1739 | /* Before trying the cache, let's make sure we figured out a server to use. Should this cause |
1740 | * a change of server this might flush the cache. */ | |
5cdb8930 | 1741 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1742 | |
4d926a69 LP |
1743 | /* Let's then prune all outdated entries */ |
1744 | dns_cache_prune(&t->scope->cache); | |
1745 | ||
775ae354 LP |
1746 | r = dns_cache_lookup( |
1747 | &t->scope->cache, | |
1748 | dns_transaction_key(t), | |
1749 | t->query_flags, | |
1750 | &t->answer_rcode, | |
1751 | &t->answer, | |
1752 | &t->received, | |
6f055e43 | 1753 | &t->answer_query_flags, |
775ae354 | 1754 | &t->answer_dnssec_result); |
4d926a69 LP |
1755 | if (r < 0) |
1756 | return r; | |
1757 | if (r > 0) { | |
3f0a7b3a LP |
1758 | dns_transaction_randomize_answer(t); |
1759 | ||
775ae354 LP |
1760 | if (t->bypass && t->scope->protocol == DNS_PROTOCOL_DNS && !t->received) |
1761 | /* When bypass mode is on, do not use cached data unless it came with a full | |
1762 | * packet. */ | |
1763 | dns_transaction_reset_answer(t); | |
1764 | else { | |
1765 | t->answer_source = DNS_TRANSACTION_CACHE; | |
1766 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
1767 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1768 | else | |
1769 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); | |
1770 | return 0; | |
1771 | } | |
4d926a69 | 1772 | } |
ec2c5e43 LP |
1773 | } |
1774 | ||
775ae354 LP |
1775 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_NETWORK)) { |
1776 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SOURCE); | |
1777 | return 0; | |
1778 | } | |
1779 | ||
1effe965 DM |
1780 | return 1; |
1781 | } | |
1782 | ||
325513bc YW |
1783 | static int dns_packet_append_zone(DnsPacket *p, DnsTransaction *t, DnsResourceKey *k, unsigned *nscount) { |
1784 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
1785 | bool tentative; | |
1786 | int r; | |
1787 | ||
1788 | assert(p); | |
1789 | assert(t); | |
1790 | assert(k); | |
1791 | ||
1792 | if (k->type != DNS_TYPE_ANY) | |
1793 | return 0; | |
1794 | ||
1795 | r = dns_zone_lookup(&t->scope->zone, k, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1796 | if (r < 0) | |
1797 | return r; | |
1798 | ||
1799 | return dns_packet_append_answer(p, answer, nscount); | |
1800 | } | |
1801 | ||
0afa57e2 | 1802 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
0afa57e2 | 1803 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
0d5ee47d | 1804 | _cleanup_set_free_ Set *keys = NULL; |
325513bc YW |
1805 | unsigned qdcount, ancount = 0 /* avoid false maybe-uninitialized warning */, nscount; |
1806 | bool add_known_answers = false; | |
0afa57e2 DM |
1807 | usec_t ts; |
1808 | int r; | |
1809 | ||
1810 | assert(t); | |
1811 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1812 | ||
e5abebab | 1813 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1814 | t->sent = dns_packet_unref(t->sent); |
1815 | ||
325513bc | 1816 | /* First, create a dummy packet to calculate packet size. */ |
0afa57e2 DM |
1817 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); |
1818 | if (r < 0) | |
1819 | return r; | |
1820 | ||
42df9532 | 1821 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
0afa57e2 DM |
1822 | if (r < 0) |
1823 | return r; | |
1824 | ||
1825 | qdcount = 1; | |
1826 | ||
42df9532 | 1827 | if (dns_key_is_shared(dns_transaction_key(t))) |
7778dfff DM |
1828 | add_known_answers = true; |
1829 | ||
325513bc YW |
1830 | r = dns_packet_append_zone(p, t, dns_transaction_key(t), NULL); |
1831 | if (r < 0) | |
1832 | return r; | |
1833 | ||
1834 | /* Save appended keys */ | |
1835 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(t)); | |
1836 | if (r < 0) | |
1837 | return r; | |
0d5ee47d | 1838 | |
0afa57e2 DM |
1839 | /* |
1840 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1841 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
5238e957 | 1842 | * in our current scope, and see whether their timing constraints allow them to be sent. |
0afa57e2 DM |
1843 | */ |
1844 | ||
ba4e0427 | 1845 | assert_se(sd_event_now(t->scope->manager->event, CLOCK_BOOTTIME, &ts) >= 0); |
0afa57e2 | 1846 | |
325513bc YW |
1847 | for (bool restart = true; restart;) { |
1848 | restart = false; | |
1849 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1850 | size_t saved_packet_size; | |
1851 | bool append = false; | |
0afa57e2 | 1852 | |
325513bc YW |
1853 | /* Skip ourselves */ |
1854 | if (other == t) | |
1855 | continue; | |
0afa57e2 | 1856 | |
325513bc YW |
1857 | if (other->state != DNS_TRANSACTION_PENDING) |
1858 | continue; | |
0afa57e2 | 1859 | |
325513bc YW |
1860 | if (other->next_attempt_after > ts) |
1861 | continue; | |
0afa57e2 | 1862 | |
325513bc YW |
1863 | if (!set_contains(keys, dns_transaction_key(other))) { |
1864 | r = dns_packet_append_key(p, dns_transaction_key(other), 0, &saved_packet_size); | |
1865 | /* If we can't stuff more questions into the packet, just give up. | |
1866 | * One of the 'other' transactions will fire later and take care of the rest. */ | |
1867 | if (r == -EMSGSIZE) | |
1868 | break; | |
1869 | if (r < 0) | |
1870 | return r; | |
0afa57e2 | 1871 | |
325513bc YW |
1872 | r = dns_packet_append_zone(p, t, dns_transaction_key(other), NULL); |
1873 | if (r == -EMSGSIZE) | |
1874 | break; | |
1875 | if (r < 0) | |
1876 | return r; | |
0afa57e2 | 1877 | |
325513bc YW |
1878 | append = true; |
1879 | } | |
0afa57e2 | 1880 | |
325513bc YW |
1881 | r = dns_transaction_prepare(other, ts); |
1882 | if (r < 0) | |
1883 | return r; | |
1884 | if (r == 0) { | |
1885 | if (append) | |
1886 | dns_packet_truncate(p, saved_packet_size); | |
0afa57e2 | 1887 | |
325513bc YW |
1888 | /* In this case, not only this transaction, but multiple transactions may be |
1889 | * freed. Hence, we need to restart the loop. */ | |
1890 | restart = true; | |
1891 | break; | |
1892 | } | |
aa4a9deb | 1893 | |
325513bc YW |
1894 | usec_t timeout = transaction_get_resend_timeout(other); |
1895 | r = dns_transaction_setup_timeout(other, timeout, usec_add(ts, timeout)); | |
1896 | if (r < 0) | |
1897 | return r; | |
0afa57e2 | 1898 | |
325513bc YW |
1899 | if (dns_key_is_shared(dns_transaction_key(other))) |
1900 | add_known_answers = true; | |
7778dfff | 1901 | |
325513bc YW |
1902 | if (append) { |
1903 | r = set_ensure_put(&keys, &dns_resource_key_hash_ops, dns_transaction_key(other)); | |
1904 | if (r < 0) | |
1905 | return r; | |
1906 | } | |
0d5ee47d | 1907 | |
325513bc YW |
1908 | qdcount++; |
1909 | if (qdcount >= UINT16_MAX) | |
1910 | break; | |
0d5ee47d | 1911 | } |
0afa57e2 DM |
1912 | } |
1913 | ||
7778dfff DM |
1914 | /* Append known answer section if we're asking for any shared record */ |
1915 | if (add_known_answers) { | |
325513bc | 1916 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p, ts, 0); |
7778dfff DM |
1917 | if (r < 0) |
1918 | return r; | |
325513bc YW |
1919 | |
1920 | ancount = be16toh(DNS_PACKET_HEADER(p)->ancount); | |
7778dfff DM |
1921 | } |
1922 | ||
5162b2a1 | 1923 | /* Then, create actual packet. */ |
325513bc YW |
1924 | p = dns_packet_unref(p); |
1925 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1926 | if (r < 0) | |
1927 | return r; | |
1928 | ||
1929 | /* Questions */ | |
1930 | DnsResourceKey *k; | |
1931 | SET_FOREACH(k, keys) { | |
1932 | r = dns_packet_append_key(p, k, 0, NULL); | |
1933 | if (r < 0) | |
1934 | return r; | |
1935 | } | |
1936 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0d5ee47d | 1937 | |
325513bc YW |
1938 | /* Known answers */ |
1939 | if (add_known_answers) { | |
1940 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p, ts, ancount); | |
0d5ee47d DR |
1941 | if (r < 0) |
1942 | return r; | |
325513bc | 1943 | } |
0d5ee47d | 1944 | |
325513bc YW |
1945 | /* Authorities */ |
1946 | nscount = 0; | |
1947 | SET_FOREACH(k, keys) { | |
1948 | r = dns_packet_append_zone(p, t, k, &nscount); | |
0d5ee47d DR |
1949 | if (r < 0) |
1950 | return r; | |
0d5ee47d DR |
1951 | } |
1952 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1953 | ||
1cc6c93a | 1954 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1955 | return 0; |
1956 | } | |
1957 | ||
1958 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1959 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1960 | int r; | |
1961 | ||
1962 | assert(t); | |
1963 | ||
1964 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1965 | return dns_transaction_make_packet_mdns(t); | |
1966 | ||
1967 | if (t->sent) | |
1968 | return 0; | |
1969 | ||
775ae354 LP |
1970 | if (t->bypass && t->bypass->protocol == t->scope->protocol) { |
1971 | /* If bypass logic is enabled and the protocol if the original packet and our scope match, | |
1972 | * take the original packet, copy it, and patch in our new ID */ | |
1973 | r = dns_packet_dup(&p, t->bypass); | |
1974 | if (r < 0) | |
1975 | return r; | |
1976 | } else { | |
1977 | r = dns_packet_new_query( | |
1978 | &p, t->scope->protocol, | |
1979 | /* min_alloc_dsize = */ 0, | |
1980 | /* dnssec_cd = */ !FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) && | |
1981 | t->scope->dnssec_mode != DNSSEC_NO); | |
1982 | if (r < 0) | |
1983 | return r; | |
0afa57e2 | 1984 | |
775ae354 LP |
1985 | r = dns_packet_append_key(p, dns_transaction_key(t), 0, NULL); |
1986 | if (r < 0) | |
1987 | return r; | |
1988 | ||
1989 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1990 | } | |
0afa57e2 | 1991 | |
0afa57e2 DM |
1992 | DNS_PACKET_HEADER(p)->id = t->id; |
1993 | ||
1cc6c93a | 1994 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1995 | return 0; |
1996 | } | |
1997 | ||
1effe965 DM |
1998 | int dns_transaction_go(DnsTransaction *t) { |
1999 | usec_t ts; | |
2000 | int r; | |
202b76ae | 2001 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
2002 | |
2003 | assert(t); | |
2004 | ||
4ea8b443 ZJS |
2005 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has |
2006 | * finished now. In the latter case, the transaction and query candidate objects must not be accessed. | |
2007 | */ | |
5278bbfe | 2008 | |
ba4e0427 | 2009 | assert_se(sd_event_now(t->scope->manager->event, CLOCK_BOOTTIME, &ts) >= 0); |
547973de | 2010 | |
c842ff24 | 2011 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
2012 | if (r <= 0) |
2013 | return r; | |
2014 | ||
213cb4f7 LP |
2015 | log_debug("Firing %s transaction %" PRIu16 " for <%s> scope %s on %s/%s (validate=%s).", |
2016 | t->bypass ? "bypass" : "regular", | |
a5784c49 | 2017 | t->id, |
42df9532 | 2018 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str), |
a5784c49 | 2019 | dns_protocol_to_string(t->scope->protocol), |
6ff79f76 | 2020 | t->scope->link ? t->scope->link->ifname : "*", |
775ae354 LP |
2021 | af_to_name_short(t->scope->family), |
2022 | yes_no(!FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE))); | |
1effe965 | 2023 | |
ef7ce6df | 2024 | if (!t->initial_jitter_scheduled && |
3742095b | 2025 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
765647ba | 2026 | usec_t jitter; |
6e068472 | 2027 | |
765647ba YW |
2028 | /* RFC 4795 Section 2.7 suggests all LLMNR queries should be delayed by a random time from 0 to |
2029 | * JITTER_INTERVAL. | |
2030 | * RFC 6762 Section 8.1 suggests initial probe queries should be delayed by a random time from | |
2031 | * 0 to 250ms. */ | |
6e068472 | 2032 | |
ef7ce6df | 2033 | t->initial_jitter_scheduled = true; |
87b91644 | 2034 | t->n_attempts = 0; |
6e068472 | 2035 | |
ea12bcc7 | 2036 | switch (t->scope->protocol) { |
519ef046 | 2037 | |
ea12bcc7 | 2038 | case DNS_PROTOCOL_LLMNR: |
9ee18bf4 | 2039 | jitter = random_u64_range(LLMNR_JITTER_INTERVAL_USEC); |
ea12bcc7 | 2040 | break; |
519ef046 | 2041 | |
ea12bcc7 | 2042 | case DNS_PROTOCOL_MDNS: |
765647ba YW |
2043 | if (t->probing) |
2044 | jitter = random_u64_range(MDNS_PROBING_INTERVAL_USEC); | |
2045 | else | |
2046 | jitter = 0; | |
ea12bcc7 DM |
2047 | break; |
2048 | default: | |
04499a70 | 2049 | assert_not_reached(); |
ea12bcc7 | 2050 | } |
6e068472 | 2051 | |
87b91644 | 2052 | r = dns_transaction_setup_timeout(t, jitter, ts); |
6e068472 LP |
2053 | if (r < 0) |
2054 | return r; | |
2055 | ||
2f9c3b2a LP |
2056 | log_debug("Delaying %s transaction %" PRIu16 " for " USEC_FMT "us.", |
2057 | dns_protocol_to_string(t->scope->protocol), | |
2058 | t->id, | |
2059 | jitter); | |
4ea8b443 | 2060 | return 1; |
6e068472 LP |
2061 | } |
2062 | ||
ec2c5e43 LP |
2063 | /* Otherwise, we need to ask the network */ |
2064 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
2065 | if (r < 0) |
2066 | return r; | |
2067 | ||
2068 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
42df9532 LP |
2069 | (dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "in-addr.arpa") > 0 || |
2070 | dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
2071 | |
2072 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
2073 | * always be made via TCP on LLMNR */ | |
98767d75 | 2074 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 2075 | } else { |
be808ea0 TG |
2076 | /* Try via UDP, and if that fails due to large size or lack of |
2077 | * support try via TCP */ | |
49cce12d | 2078 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
2079 | if (r == -EMSGSIZE) |
2080 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 2081 | else if (r == -EAGAIN) |
6c0bacc1 | 2082 | log_debug("Sending query via TCP since UDP isn't supported or DNS-over-TLS is selected."); |
4c701096 | 2083 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
98767d75 | 2084 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 2085 | } |
49ef064c LP |
2086 | if (r == -ELOOP) { |
2087 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
2088 | return r; | |
2089 | ||
2090 | /* One of our own stub listeners */ | |
2091 | log_debug_errno(r, "Detected that specified DNS server is our own extra listener, switching DNS servers."); | |
2092 | ||
5e8bc852 | 2093 | dns_scope_next_dns_server(t->scope, t->server); |
49ef064c LP |
2094 | |
2095 | if (dns_scope_get_dns_server(t->scope) == t->server) { | |
2096 | log_debug_errno(r, "Still pointing to extra listener after switching DNS servers, refusing operation."); | |
2097 | dns_transaction_complete(t, DNS_TRANSACTION_STUB_LOOP); | |
2098 | return 0; | |
2099 | } | |
be808ea0 | 2100 | |
49ef064c LP |
2101 | return dns_transaction_go(t); |
2102 | } | |
ec2c5e43 LP |
2103 | if (r == -ESRCH) { |
2104 | /* No servers to send this to? */ | |
2105 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
2106 | return 0; | |
91adc4db LP |
2107 | } |
2108 | if (r == -EOPNOTSUPP) { | |
2109 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
2110 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
2111 | return 0; | |
2112 | } | |
95d2155a | 2113 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(r)) { |
e94968ba | 2114 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
2115 | * answer this request with this protocol. */ |
2116 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
2117 | return 0; | |
2118 | } | |
91adc4db | 2119 | if (r < 0) { |
7cc6ed7b LP |
2120 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
2121 | return r; | |
13b551ac | 2122 | |
ec2c5e43 | 2123 | /* Couldn't send? Try immediately again, with a new server */ |
5e8bc852 | 2124 | dns_scope_next_dns_server(t->scope, t->server); |
ec2c5e43 LP |
2125 | |
2126 | return dns_transaction_go(t); | |
2127 | } | |
2128 | ||
87b91644 YW |
2129 | usec_t timeout = transaction_get_resend_timeout(t); |
2130 | r = dns_transaction_setup_timeout(t, timeout, usec_add(ts, timeout)); | |
ec2c5e43 LP |
2131 | if (r < 0) |
2132 | return r; | |
2133 | ||
ec2c5e43 LP |
2134 | return 1; |
2135 | } | |
2136 | ||
f2992dc1 LP |
2137 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
2138 | DnsTransaction *n; | |
f2992dc1 LP |
2139 | int r; |
2140 | ||
2141 | assert(t); | |
2142 | assert(aux); | |
2143 | ||
2144 | /* Try to find cyclic dependencies between transaction objects */ | |
2145 | ||
2146 | if (t == aux) | |
2147 | return 1; | |
2148 | ||
90e74a66 | 2149 | SET_FOREACH(n, aux->dnssec_transactions) { |
f2992dc1 LP |
2150 | r = dns_transaction_find_cyclic(t, n); |
2151 | if (r != 0) | |
2152 | return r; | |
2153 | } | |
2154 | ||
3eb6aa00 | 2155 | return 0; |
f2992dc1 LP |
2156 | } |
2157 | ||
547973de | 2158 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
29bd6012 | 2159 | _cleanup_(dns_transaction_gcp) DnsTransaction *aux = NULL; |
547973de LP |
2160 | int r; |
2161 | ||
2162 | assert(t); | |
2163 | assert(ret); | |
2164 | assert(key); | |
2165 | ||
775ae354 | 2166 | aux = dns_scope_find_transaction(t->scope, key, t->query_flags); |
547973de | 2167 | if (!aux) { |
775ae354 | 2168 | r = dns_transaction_new(&aux, t->scope, key, NULL, t->query_flags); |
547973de LP |
2169 | if (r < 0) |
2170 | return r; | |
2171 | } else { | |
2172 | if (set_contains(t->dnssec_transactions, aux)) { | |
2173 | *ret = aux; | |
2174 | return 0; | |
2175 | } | |
f2992dc1 LP |
2176 | |
2177 | r = dns_transaction_find_cyclic(t, aux); | |
2178 | if (r < 0) | |
2179 | return r; | |
2180 | if (r > 0) { | |
202b76ae ZJS |
2181 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
2182 | ||
baaa35ad ZJS |
2183 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), |
2184 | "Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
2185 | aux->id, | |
42df9532 | 2186 | dns_resource_key_to_string(dns_transaction_key(t), s, sizeof s), |
baaa35ad | 2187 | t->id, |
42df9532 | 2188 | dns_resource_key_to_string(dns_transaction_key(aux), saux, sizeof saux)); |
f2992dc1 | 2189 | } |
547973de LP |
2190 | } |
2191 | ||
35aa04e9 LP |
2192 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); |
2193 | if (r < 0) | |
29bd6012 | 2194 | return r; |
547973de | 2195 | |
de7fef4b | 2196 | r = set_ensure_put(&t->dnssec_transactions, NULL, aux); |
547973de | 2197 | if (r < 0) |
a75cb4e2 | 2198 | return r; |
547973de | 2199 | |
de7fef4b | 2200 | r = set_ensure_put(&aux->notify_transactions, NULL, t); |
547973de LP |
2201 | if (r < 0) { |
2202 | (void) set_remove(t->dnssec_transactions, aux); | |
29bd6012 | 2203 | return r; |
547973de LP |
2204 | } |
2205 | ||
29bd6012 | 2206 | *ret = TAKE_PTR(aux); |
547973de | 2207 | return 1; |
547973de LP |
2208 | } |
2209 | ||
2210 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
2211 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
2212 | DnsTransaction *aux; | |
2213 | int r; | |
2214 | ||
2215 | assert(t); | |
2216 | assert(key); | |
2217 | ||
2218 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 2219 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
2220 | if (r < 0) |
2221 | return r; | |
2222 | if (r > 0) { | |
2223 | r = dns_answer_extend(&t->validated_keys, a); | |
2224 | if (r < 0) | |
2225 | return r; | |
2226 | ||
2227 | return 0; | |
2228 | } | |
2229 | ||
2230 | /* This didn't work, ask for it via the network/cache then. */ | |
2231 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
2232 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
2233 | return 0; | |
547973de LP |
2234 | if (r < 0) |
2235 | return r; | |
2236 | ||
2237 | if (aux->state == DNS_TRANSACTION_NULL) { | |
2238 | r = dns_transaction_go(aux); | |
2239 | if (r < 0) | |
2240 | return r; | |
2241 | } | |
2242 | ||
f2992dc1 | 2243 | return 1; |
547973de LP |
2244 | } |
2245 | ||
8a516214 LP |
2246 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
2247 | int r; | |
2248 | ||
2249 | assert(t); | |
2250 | ||
c629ff58 | 2251 | /* Check whether the specified name is in the NTA |
8a516214 LP |
2252 | * database, either in the global one, or the link-local |
2253 | * one. */ | |
2254 | ||
2255 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
2256 | if (r != 0) | |
2257 | return r; | |
2258 | ||
2259 | if (!t->scope->link) | |
2260 | return 0; | |
2261 | ||
7e8a93b7 | 2262 | return link_negative_trust_anchor_lookup(t->scope->link, name); |
8a516214 LP |
2263 | } |
2264 | ||
26b23d11 | 2265 | static int dns_transaction_has_negative_answer(DnsTransaction *t) { |
105e1512 LP |
2266 | int r; |
2267 | ||
2268 | assert(t); | |
2269 | ||
2270 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
2271 | * RRs to prove it */ | |
2272 | ||
2273 | r = dns_transaction_has_positive_answer(t, NULL); | |
2274 | if (r < 0) | |
2275 | return r; | |
2276 | if (r > 0) | |
2277 | return false; | |
2278 | ||
8e54f5d9 LP |
2279 | /* Is this key explicitly listed as a negative trust anchor? |
2280 | * If so, it's nothing we need to care about */ | |
42df9532 | 2281 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
2282 | if (r < 0) |
2283 | return r; | |
26b23d11 | 2284 | return !r; |
105e1512 LP |
2285 | } |
2286 | ||
2287 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
2288 | int r; | |
2289 | ||
2290 | assert(t); | |
2291 | assert(rr); | |
2292 | ||
2293 | /* Check if the specified RR is the "primary" response, | |
2294 | * i.e. either matches the question precisely or is a | |
4cb94977 | 2295 | * CNAME/DNAME for it. */ |
105e1512 | 2296 | |
42df9532 | 2297 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
2298 | if (r != 0) |
2299 | return r; | |
2300 | ||
42df9532 | 2301 | return dns_resource_key_match_cname_or_dname(dns_transaction_key(t), rr->key, NULL); |
105e1512 LP |
2302 | } |
2303 | ||
92ec902a LP |
2304 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
2305 | assert(t); | |
2306 | ||
2307 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
2308 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
2309 | ||
2310 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
2311 | return false; | |
2312 | ||
2313 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
2314 | * be supported, hence return true. */ | |
2315 | if (!t->server) | |
2316 | return true; | |
2317 | ||
d001e0a3 LP |
2318 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
2319 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
2320 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
2321 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
2322 | |
2323 | return dns_server_dnssec_supported(t->server); | |
2324 | } | |
2325 | ||
2326 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
2327 | DnsTransaction *dt; | |
92ec902a LP |
2328 | |
2329 | assert(t); | |
2330 | ||
2331 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
2332 | ||
2333 | if (!dns_transaction_dnssec_supported(t)) | |
2334 | return false; | |
2335 | ||
90e74a66 | 2336 | SET_FOREACH(dt, t->dnssec_transactions) |
92ec902a LP |
2337 | if (!dns_transaction_dnssec_supported(dt)) |
2338 | return false; | |
2339 | ||
2340 | return true; | |
2341 | } | |
2342 | ||
547973de LP |
2343 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
2344 | DnsResourceRecord *rr; | |
105e1512 | 2345 | |
547973de LP |
2346 | int r; |
2347 | ||
2348 | assert(t); | |
2349 | ||
105e1512 LP |
2350 | /* |
2351 | * Retrieve all auxiliary RRs for the answer we got, so that | |
2352 | * we can verify signatures or prove that RRs are rightfully | |
2353 | * unsigned. Specifically: | |
2354 | * | |
2355 | * - For RRSIG we get the matching DNSKEY | |
2356 | * - For DNSKEY we get the matching DS | |
2357 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 2358 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 2359 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
2360 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
2361 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
2362 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
2363 | */ | |
2364 | ||
775ae354 | 2365 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) || t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 2366 | return 0; |
92ec902a LP |
2367 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
2368 | return 0; /* We only need to validate stuff from the network */ | |
2369 | if (!dns_transaction_dnssec_supported(t)) | |
5238e957 | 2370 | return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */ |
b652d4a2 | 2371 | |
547973de LP |
2372 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2373 | ||
105e1512 LP |
2374 | if (dns_type_is_pseudo(rr->key->type)) |
2375 | continue; | |
2376 | ||
8e54f5d9 | 2377 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 2378 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2379 | if (r < 0) |
2380 | return r; | |
2381 | if (r > 0) | |
2382 | continue; | |
2383 | ||
547973de LP |
2384 | switch (rr->key->type) { |
2385 | ||
2386 | case DNS_TYPE_RRSIG: { | |
2387 | /* For each RRSIG we request the matching DNSKEY */ | |
2388 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
2389 | ||
2390 | /* If this RRSIG is about a DNSKEY RR and the | |
2391 | * signer is the same as the owner, then we | |
2392 | * already have the DNSKEY, and we don't have | |
2393 | * to look for more. */ | |
2394 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 2395 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
2396 | if (r < 0) |
2397 | return r; | |
2398 | if (r > 0) | |
2399 | continue; | |
2400 | } | |
2401 | ||
105e1512 LP |
2402 | /* If the signer is not a parent of our |
2403 | * original query, then this is about an | |
2404 | * auxiliary RRset, but not anything we asked | |
2405 | * for. In this case we aren't interested, | |
2406 | * because we don't want to request additional | |
2407 | * RRs for stuff we didn't really ask for, and | |
2408 | * also to avoid request loops, where | |
2409 | * additional RRs from one transaction result | |
5238e957 | 2410 | * in another transaction whose additional RRs |
105e1512 LP |
2411 | * point back to the original transaction, and |
2412 | * we deadlock. */ | |
42df9532 | 2413 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), rr->rrsig.signer); |
547973de LP |
2414 | if (r < 0) |
2415 | return r; | |
2416 | if (r == 0) | |
2417 | continue; | |
2418 | ||
2419 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2420 | if (!dnskey) | |
2421 | return -ENOMEM; | |
2422 | ||
1c02e7ba ZJS |
2423 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2424 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2425 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2426 | if (r < 0) | |
2427 | return r; | |
2428 | break; | |
2429 | } | |
2430 | ||
2431 | case DNS_TYPE_DNSKEY: { | |
2432 | /* For each DNSKEY we request the matching DS */ | |
2433 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2434 | ||
105e1512 LP |
2435 | /* If the DNSKEY we are looking at is not for |
2436 | * zone we are interested in, nor any of its | |
2437 | * parents, we aren't interested, and don't | |
2438 | * request it. After all, we don't want to end | |
2439 | * up in request loops, and want to keep | |
2440 | * additional traffic down. */ | |
2441 | ||
42df9532 | 2442 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2443 | if (r < 0) |
2444 | return r; | |
2445 | if (r == 0) | |
2446 | continue; | |
2447 | ||
1c02e7ba | 2448 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2449 | if (!ds) |
2450 | return -ENOMEM; | |
2451 | ||
1c02e7ba ZJS |
2452 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2453 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2454 | r = dns_transaction_request_dnssec_rr(t, ds); |
2455 | if (r < 0) | |
2456 | return r; | |
547973de | 2457 | |
105e1512 LP |
2458 | break; |
2459 | } | |
2460 | ||
105e1512 LP |
2461 | case DNS_TYPE_SOA: |
2462 | case DNS_TYPE_NS: { | |
2463 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2464 | ||
2465 | /* For an unsigned SOA or NS, try to acquire | |
2466 | * the matching DS RR, as we are at a zone cut | |
2467 | * then, and whether a DS exists tells us | |
2468 | * whether the zone is signed. Do so only if | |
2469 | * this RR matches our original question, | |
2470 | * however. */ | |
2471 | ||
42df9532 | 2472 | r = dns_resource_key_match_rr(dns_transaction_key(t), rr, NULL); |
105e1512 LP |
2473 | if (r < 0) |
2474 | return r; | |
6993d264 LP |
2475 | if (r == 0) { |
2476 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
d51c4fca | 2477 | * a negative reply, and we need the SOA RR's TTL in order to cache a negative entry? |
6993d264 LP |
2478 | * If so, we need to validate it, too. */ |
2479 | ||
42df9532 | 2480 | r = dns_answer_match_key(t->answer, dns_transaction_key(t), NULL); |
6993d264 LP |
2481 | if (r < 0) |
2482 | return r; | |
2483 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2484 | * it. */ | |
2485 | continue; | |
d5acaa51 LP |
2486 | |
2487 | /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of | |
2488 | * what we are looking for, otherwise there's no value in it for us. */ | |
42df9532 | 2489 | r = dns_name_endswith(dns_resource_key_name(dns_transaction_key(t)), dns_resource_key_name(rr->key)); |
d5acaa51 LP |
2490 | if (r < 0) |
2491 | return r; | |
2492 | if (r == 0) | |
2493 | continue; | |
6993d264 | 2494 | } |
105e1512 LP |
2495 | |
2496 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2497 | if (r < 0) | |
2498 | return r; | |
2499 | if (r > 0) | |
2500 | continue; | |
2501 | ||
1c02e7ba | 2502 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2503 | if (!ds) |
2504 | return -ENOMEM; | |
2505 | ||
1c02e7ba ZJS |
2506 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2507 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2508 | r = dns_transaction_request_dnssec_rr(t, ds); |
2509 | if (r < 0) | |
2510 | return r; | |
2511 | ||
2512 | break; | |
105e1512 LP |
2513 | } |
2514 | ||
b63fca62 | 2515 | case DNS_TYPE_DS: |
105e1512 LP |
2516 | case DNS_TYPE_CNAME: |
2517 | case DNS_TYPE_DNAME: { | |
2518 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2519 | const char *name; | |
2520 | ||
2521 | /* CNAMEs and DNAMEs cannot be located at a | |
2522 | * zone apex, hence ask for the parent SOA for | |
2523 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2524 | * apex. But do all that only if this is | |
2525 | * actually a response to our original | |
b63fca62 LP |
2526 | * question. |
2527 | * | |
2528 | * Similar for DS RRs, which are signed when | |
2529 | * the parent SOA is signed. */ | |
105e1512 LP |
2530 | |
2531 | r = dns_transaction_is_primary_response(t, rr); | |
2532 | if (r < 0) | |
2533 | return r; | |
2534 | if (r == 0) | |
2535 | continue; | |
2536 | ||
2537 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2538 | if (r < 0) | |
2539 | return r; | |
2540 | if (r > 0) | |
2541 | continue; | |
2542 | ||
43e6779a LP |
2543 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2544 | if (r < 0) | |
2545 | return r; | |
2546 | if (r > 0) | |
2547 | continue; | |
2548 | ||
1c02e7ba | 2549 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2550 | r = dns_name_parent(&name); |
2551 | if (r < 0) | |
2552 | return r; | |
2553 | if (r == 0) | |
2554 | continue; | |
2555 | ||
2556 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2557 | if (!soa) | |
2558 | return -ENOMEM; | |
2559 | ||
1c02e7ba ZJS |
2560 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2561 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2562 | r = dns_transaction_request_dnssec_rr(t, soa); |
2563 | if (r < 0) | |
2564 | return r; | |
2565 | ||
2566 | break; | |
2567 | } | |
2568 | ||
2569 | default: { | |
2570 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2571 | ||
b63fca62 LP |
2572 | /* For other unsigned RRsets (including |
2573 | * NSEC/NSEC3!), look for proof the zone is | |
2574 | * unsigned, by requesting the SOA RR of the | |
2575 | * zone. However, do so only if they are | |
2576 | * directly relevant to our original | |
105e1512 LP |
2577 | * question. */ |
2578 | ||
2579 | r = dns_transaction_is_primary_response(t, rr); | |
2580 | if (r < 0) | |
2581 | return r; | |
2582 | if (r == 0) | |
2583 | continue; | |
2584 | ||
2585 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2586 | if (r < 0) | |
2587 | return r; | |
2588 | if (r > 0) | |
2589 | continue; | |
2590 | ||
1c02e7ba | 2591 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2592 | if (!soa) |
2593 | return -ENOMEM; | |
2594 | ||
1c02e7ba ZJS |
2595 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2596 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2597 | r = dns_transaction_request_dnssec_rr(t, soa); |
2598 | if (r < 0) | |
2599 | return r; | |
2600 | break; | |
547973de LP |
2601 | }} |
2602 | } | |
2603 | ||
105e1512 LP |
2604 | /* Above, we requested everything necessary to validate what |
2605 | * we got. Now, let's request what we need to validate what we | |
2606 | * didn't get... */ | |
2607 | ||
26b23d11 | 2608 | r = dns_transaction_has_negative_answer(t); |
105e1512 LP |
2609 | if (r < 0) |
2610 | return r; | |
2611 | if (r > 0) { | |
26b23d11 | 2612 | const char *name, *signed_status; |
4bbc06cc | 2613 | uint16_t type = 0; |
105e1512 | 2614 | |
42df9532 | 2615 | name = dns_resource_key_name(dns_transaction_key(t)); |
26b23d11 | 2616 | signed_status = dns_answer_contains_nsec_or_nsec3(t->answer) ? "signed" : "unsigned"; |
105e1512 | 2617 | |
4bbc06cc LP |
2618 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2619 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2620 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2621 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2622 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2623 | * to see if that is signed. */ | |
105e1512 | 2624 | |
42df9532 | 2625 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2626 | r = dns_name_parent(&name); |
4bbc06cc LP |
2627 | if (r > 0) { |
2628 | type = DNS_TYPE_SOA; | |
e2341b6b DT |
2629 | log_debug("Requesting parent SOA (%s %s) to validate transaction %" PRIu16 " (%s, %s empty DS response).", |
2630 | special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), name, t->id, | |
2631 | dns_resource_key_name(dns_transaction_key(t)), signed_status); | |
4bbc06cc | 2632 | } else |
105e1512 | 2633 | name = NULL; |
4bbc06cc | 2634 | |
42df9532 | 2635 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { |
4bbc06cc LP |
2636 | |
2637 | type = DNS_TYPE_DS; | |
e2341b6b DT |
2638 | log_debug("Requesting DS (%s %s) to validate transaction %" PRIu16 " (%s, %s empty SOA/NS response).", |
2639 | special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), name, t->id, name, signed_status); | |
4bbc06cc LP |
2640 | |
2641 | } else { | |
2642 | type = DNS_TYPE_SOA; | |
e2341b6b DT |
2643 | log_debug("Requesting SOA (%s %s) to validate transaction %" PRIu16 " (%s, %s empty non-SOA/NS/DS response).", |
2644 | special_glyph(SPECIAL_GLYPH_ARROW_RIGHT), name, t->id, name, signed_status); | |
4bbc06cc | 2645 | } |
105e1512 LP |
2646 | |
2647 | if (name) { | |
2648 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2649 | ||
42df9532 | 2650 | soa = dns_resource_key_new(dns_transaction_key(t)->class, type, name); |
105e1512 LP |
2651 | if (!soa) |
2652 | return -ENOMEM; | |
2653 | ||
2654 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2655 | if (r < 0) | |
2656 | return r; | |
2657 | } | |
2658 | } | |
2659 | ||
2660 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2661 | } |
2662 | ||
2663 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2664 | assert(t); |
547973de LP |
2665 | assert(source); |
2666 | ||
942eb2e7 LP |
2667 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2668 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2669 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2670 | |
942eb2e7 LP |
2671 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2672 | dns_transaction_process_dnssec(t); | |
547973de LP |
2673 | } |
2674 | ||
105e1512 | 2675 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
04617bf8 LP |
2676 | DnsAnswerItem *item; |
2677 | int r; | |
105e1512 LP |
2678 | |
2679 | assert(t); | |
2680 | ||
2681 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2682 | * RRs from the list of validated keys to the list of | |
2683 | * validated keys. */ | |
2684 | ||
04617bf8 | 2685 | DNS_ANSWER_FOREACH_ITEM(item, t->answer) { |
105e1512 | 2686 | |
04617bf8 | 2687 | r = dnssec_verify_dnskey_by_ds_search(item->rr, t->validated_keys); |
105e1512 LP |
2688 | if (r < 0) |
2689 | return r; | |
2690 | if (r == 0) | |
2691 | continue; | |
2692 | ||
2693 | /* If so, the DNSKEY is validated too. */ | |
04617bf8 | 2694 | r = dns_answer_add_extend(&t->validated_keys, item->rr, item->ifindex, item->flags|DNS_ANSWER_AUTHENTICATED, item->rrsig); |
105e1512 LP |
2695 | if (r < 0) |
2696 | return r; | |
2697 | } | |
2698 | ||
2699 | return 0; | |
2700 | } | |
2701 | ||
2702 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2703 | int r; |
2704 | ||
2705 | assert(t); | |
2706 | assert(rr); | |
2707 | ||
105e1512 LP |
2708 | /* Checks if the RR we are looking for must be signed with an |
2709 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2710 | |
b652d4a2 | 2711 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2712 | return false; |
56352fe9 | 2713 | |
105e1512 LP |
2714 | if (dns_type_is_pseudo(rr->key->type)) |
2715 | return -EINVAL; | |
56352fe9 | 2716 | |
1c02e7ba | 2717 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2718 | if (r < 0) |
2719 | return r; | |
2720 | if (r > 0) | |
2721 | return false; | |
2722 | ||
105e1512 | 2723 | switch (rr->key->type) { |
56352fe9 | 2724 | |
105e1512 LP |
2725 | case DNS_TYPE_RRSIG: |
2726 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2727 | return false; | |
2728 | ||
2729 | case DNS_TYPE_SOA: | |
2730 | case DNS_TYPE_NS: { | |
2731 | DnsTransaction *dt; | |
105e1512 | 2732 | |
b63fca62 | 2733 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 | 2734 | |
90e74a66 | 2735 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2736 | |
42df9532 | 2737 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2738 | continue; |
42df9532 | 2739 | if (dns_transaction_key(dt)->type != DNS_TYPE_DS) |
105e1512 LP |
2740 | continue; |
2741 | ||
42df9532 | 2742 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2743 | if (r < 0) |
2744 | return r; | |
2745 | if (r == 0) | |
2746 | continue; | |
2747 | ||
2748 | /* We found a DS transactions for the SOA/NS | |
2749 | * RRs we are looking at. If it discovered signed DS | |
2750 | * RRs, then we need to be signed, too. */ | |
2751 | ||
6f055e43 | 2752 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
097a2517 | 2753 | return false; |
105e1512 | 2754 | |
42df9532 | 2755 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
105e1512 LP |
2756 | } |
2757 | ||
2758 | /* We found nothing that proves this is safe to leave | |
2759 | * this unauthenticated, hence ask inist on | |
2760 | * authentication. */ | |
2761 | return true; | |
2762 | } | |
2763 | ||
b63fca62 | 2764 | case DNS_TYPE_DS: |
105e1512 LP |
2765 | case DNS_TYPE_CNAME: |
2766 | case DNS_TYPE_DNAME: { | |
2767 | const char *parent = NULL; | |
2768 | DnsTransaction *dt; | |
105e1512 | 2769 | |
b63fca62 LP |
2770 | /* |
2771 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2772 | * | |
2773 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2774 | */ | |
105e1512 | 2775 | |
90e74a66 | 2776 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2777 | |
42df9532 | 2778 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2779 | continue; |
42df9532 | 2780 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2781 | continue; |
2782 | ||
2783 | if (!parent) { | |
1c02e7ba | 2784 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2785 | r = dns_name_parent(&parent); |
2786 | if (r < 0) | |
2787 | return r; | |
2788 | if (r == 0) { | |
b63fca62 LP |
2789 | if (rr->key->type == DNS_TYPE_DS) |
2790 | return true; | |
2791 | ||
105e1512 | 2792 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
baaa35ad ZJS |
2793 | return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), |
2794 | "Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
105e1512 LP |
2795 | } |
2796 | } | |
2797 | ||
42df9532 | 2798 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), parent); |
105e1512 LP |
2799 | if (r < 0) |
2800 | return r; | |
2801 | if (r == 0) | |
2802 | continue; | |
2803 | ||
6f055e43 | 2804 | return FLAGS_SET(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED); |
105e1512 LP |
2805 | } |
2806 | ||
2807 | return true; | |
2808 | } | |
2809 | ||
2810 | default: { | |
2811 | DnsTransaction *dt; | |
105e1512 | 2812 | |
b63fca62 | 2813 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 | 2814 | |
90e74a66 | 2815 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2816 | |
42df9532 | 2817 | if (dns_transaction_key(dt)->class != rr->key->class) |
105e1512 | 2818 | continue; |
42df9532 | 2819 | if (dns_transaction_key(dt)->type != DNS_TYPE_SOA) |
105e1512 LP |
2820 | continue; |
2821 | ||
42df9532 | 2822 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), dns_resource_key_name(rr->key)); |
105e1512 LP |
2823 | if (r < 0) |
2824 | return r; | |
2825 | if (r == 0) | |
2826 | continue; | |
2827 | ||
6f055e43 LP |
2828 | /* We found the transaction that was supposed to find the SOA RR for us. It was |
2829 | * successful, but found no RR for us. This means we are not at a zone cut. In this | |
2830 | * case, we require authentication if the SOA lookup was authenticated too. */ | |
2831 | return FLAGS_SET(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED); | |
105e1512 LP |
2832 | } |
2833 | ||
2834 | return true; | |
2835 | }} | |
56352fe9 LP |
2836 | } |
2837 | ||
d33b6cf3 LP |
2838 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2839 | DnsTransaction *dt; | |
2840 | const char *tld; | |
d33b6cf3 LP |
2841 | int r; |
2842 | ||
2843 | /* If DNSSEC downgrade mode is on, checks whether the | |
2844 | * specified RR is one level below a TLD we have proven not to | |
2845 | * exist. In such a case we assume that this is a private | |
2846 | * domain, and permit it. | |
2847 | * | |
2848 | * This detects cases like the Fritz!Box router networks. Each | |
2849 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2850 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2851 | * are served by the router itself, while requests for the | |
2852 | * "box" domain will result in NXDOMAIN. | |
2853 | * | |
2854 | * Note that this logic is unable to detect cases where a | |
2855 | * router serves a private DNS zone directly under | |
2856 | * non-existing TLD. In such a case we cannot detect whether | |
2857 | * the TLD is supposed to exist or not, as all requests we | |
2858 | * make for it will be answered by the router's zone, and not | |
2859 | * by the root zone. */ | |
2860 | ||
2861 | assert(t); | |
2862 | ||
2863 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2864 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2865 | ||
1c02e7ba | 2866 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2867 | r = dns_name_parent(&tld); |
2868 | if (r < 0) | |
2869 | return r; | |
2870 | if (r == 0) | |
2871 | return false; /* Already the root domain */ | |
2872 | ||
2873 | if (!dns_name_is_single_label(tld)) | |
2874 | return false; | |
2875 | ||
90e74a66 | 2876 | SET_FOREACH(dt, t->dnssec_transactions) { |
d33b6cf3 | 2877 | |
42df9532 | 2878 | if (dns_transaction_key(dt)->class != key->class) |
d33b6cf3 LP |
2879 | continue; |
2880 | ||
42df9532 | 2881 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), tld); |
d33b6cf3 LP |
2882 | if (r < 0) |
2883 | return r; | |
2884 | if (r == 0) | |
2885 | continue; | |
2886 | ||
2887 | /* We found an auxiliary lookup we did for the TLD. If | |
2888 | * that returned with NXDOMAIN, we know the TLD didn't | |
2889 | * exist, and hence this might be a private zone. */ | |
2890 | ||
2891 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2892 | } | |
2893 | ||
2894 | return false; | |
2895 | } | |
2896 | ||
105e1512 | 2897 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2898 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2899 | DnsTransaction *dt; |
2900 | const char *name; | |
4bbc06cc | 2901 | uint16_t type = 0; |
105e1512 | 2902 | int r; |
56352fe9 LP |
2903 | |
2904 | assert(t); | |
2905 | ||
105e1512 LP |
2906 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2907 | * this negative reply */ | |
56352fe9 | 2908 | |
b652d4a2 | 2909 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2910 | return false; |
56352fe9 | 2911 | |
42df9532 | 2912 | if (dns_type_is_pseudo(dns_transaction_key(t)->type)) |
105e1512 LP |
2913 | return -EINVAL; |
2914 | ||
42df9532 | 2915 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(dns_transaction_key(t))); |
8e54f5d9 LP |
2916 | if (r < 0) |
2917 | return r; | |
2918 | if (r > 0) | |
2919 | return false; | |
2920 | ||
42df9532 | 2921 | r = dns_transaction_in_private_tld(t, dns_transaction_key(t)); |
d33b6cf3 LP |
2922 | if (r < 0) |
2923 | return r; | |
2924 | if (r > 0) { | |
2925 | /* The lookup is from a TLD that is proven not to | |
2926 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2927 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2928 | |
202b76ae | 2929 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
42df9532 | 2930 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
d33b6cf3 LP |
2931 | return false; |
2932 | } | |
2933 | ||
42df9532 | 2934 | name = dns_resource_key_name(dns_transaction_key(t)); |
105e1512 | 2935 | |
42df9532 | 2936 | if (dns_transaction_key(t)->type == DNS_TYPE_DS) { |
105e1512 | 2937 | |
4bbc06cc LP |
2938 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2939 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2940 | |
2941 | r = dns_name_parent(&name); | |
56352fe9 LP |
2942 | if (r < 0) |
2943 | return r; | |
2944 | if (r == 0) | |
105e1512 | 2945 | return true; |
4bbc06cc LP |
2946 | |
2947 | type = DNS_TYPE_SOA; | |
2948 | ||
42df9532 | 2949 | } else if (IN_SET(dns_transaction_key(t)->type, DNS_TYPE_SOA, DNS_TYPE_NS)) |
4bbc06cc LP |
2950 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ |
2951 | type = DNS_TYPE_DS; | |
2952 | else | |
2953 | /* For all other negative replies, check for the SOA lookup */ | |
2954 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2955 | |
2956 | /* For all other RRs we check the SOA on the same level to see | |
2957 | * if it's signed. */ | |
2958 | ||
90e74a66 | 2959 | SET_FOREACH(dt, t->dnssec_transactions) { |
105e1512 | 2960 | |
42df9532 | 2961 | if (dns_transaction_key(dt)->class != dns_transaction_key(t)->class) |
105e1512 | 2962 | continue; |
42df9532 | 2963 | if (dns_transaction_key(dt)->type != type) |
56352fe9 LP |
2964 | continue; |
2965 | ||
42df9532 | 2966 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), name); |
56352fe9 LP |
2967 | if (r < 0) |
2968 | return r; | |
105e1512 LP |
2969 | if (r == 0) |
2970 | continue; | |
2971 | ||
6f055e43 | 2972 | return FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED); |
56352fe9 LP |
2973 | } |
2974 | ||
105e1512 LP |
2975 | /* If in doubt, require NSEC/NSEC3 */ |
2976 | return true; | |
56352fe9 LP |
2977 | } |
2978 | ||
94aa7071 LP |
2979 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2980 | DnsResourceRecord *rrsig; | |
2981 | bool found = false; | |
2982 | int r; | |
2983 | ||
2984 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2985 | * the specified RRset is authenticated (i.e. has a matching | |
2986 | * DS RR). */ | |
2987 | ||
1c02e7ba | 2988 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2989 | if (r < 0) |
2990 | return r; | |
2991 | if (r > 0) | |
2992 | return false; | |
2993 | ||
94aa7071 LP |
2994 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2995 | DnsTransaction *dt; | |
94aa7071 LP |
2996 | |
2997 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2998 | if (r < 0) | |
2999 | return r; | |
3000 | if (r == 0) | |
3001 | continue; | |
3002 | ||
90e74a66 | 3003 | SET_FOREACH(dt, t->dnssec_transactions) { |
94aa7071 | 3004 | |
42df9532 | 3005 | if (dns_transaction_key(dt)->class != rr->key->class) |
94aa7071 LP |
3006 | continue; |
3007 | ||
42df9532 | 3008 | if (dns_transaction_key(dt)->type == DNS_TYPE_DNSKEY) { |
94aa7071 | 3009 | |
42df9532 | 3010 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
3011 | if (r < 0) |
3012 | return r; | |
3013 | if (r == 0) | |
3014 | continue; | |
3015 | ||
6f055e43 LP |
3016 | /* OK, we found an auxiliary DNSKEY lookup. If that lookup is authenticated, |
3017 | * report this. */ | |
94aa7071 | 3018 | |
6f055e43 | 3019 | if (FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
94aa7071 LP |
3020 | return true; |
3021 | ||
3022 | found = true; | |
3023 | ||
42df9532 | 3024 | } else if (dns_transaction_key(dt)->type == DNS_TYPE_DS) { |
94aa7071 | 3025 | |
42df9532 | 3026 | r = dns_name_equal(dns_resource_key_name(dns_transaction_key(dt)), rrsig->rrsig.signer); |
94aa7071 LP |
3027 | if (r < 0) |
3028 | return r; | |
3029 | if (r == 0) | |
3030 | continue; | |
3031 | ||
6f055e43 LP |
3032 | /* OK, we found an auxiliary DS lookup. If that lookup is authenticated and |
3033 | * non-zero, we won! */ | |
94aa7071 | 3034 | |
6f055e43 | 3035 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
94aa7071 LP |
3036 | return false; |
3037 | ||
42df9532 | 3038 | return dns_answer_match_key(dt->answer, dns_transaction_key(dt), NULL); |
94aa7071 LP |
3039 | } |
3040 | } | |
3041 | } | |
3042 | ||
3043 | return found ? false : -ENXIO; | |
3044 | } | |
3045 | ||
b652d4a2 LP |
3046 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
3047 | assert(t); | |
3048 | assert(rr); | |
3049 | ||
3050 | /* We know that the root domain is signed, hence if it appears | |
3051 | * not to be signed, there's a problem with the DNS server */ | |
3052 | ||
3053 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 3054 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
3055 | } |
3056 | ||
0f87f3e8 LP |
3057 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
3058 | DnsResourceRecord *rr; | |
3059 | int r; | |
3060 | ||
3061 | assert(t); | |
3062 | ||
3063 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
3064 | * for a key from our trust anchor. Note that we don't care | |
3065 | * whether the DNSKEY can be authenticated or not. It's | |
3066 | * sufficient if it is self-signed. */ | |
3067 | ||
3068 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 3069 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
3070 | if (r < 0) |
3071 | return r; | |
3072 | } | |
3073 | ||
3074 | return 0; | |
3075 | } | |
3076 | ||
c9c72065 LP |
3077 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
3078 | bool changed; | |
3079 | int r; | |
3080 | ||
3081 | assert(t); | |
3082 | ||
3083 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
3084 | * our trust anchors database considers revoked. */ | |
3085 | ||
3086 | do { | |
3087 | DnsResourceRecord *rr; | |
3088 | ||
3089 | changed = false; | |
3090 | ||
3091 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
3092 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
3093 | if (r < 0) | |
3094 | return r; | |
3095 | if (r > 0) { | |
3096 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
3097 | if (r < 0) | |
3098 | return r; | |
3099 | ||
3100 | assert(r > 0); | |
3101 | changed = true; | |
3102 | break; | |
3103 | } | |
3104 | } | |
3105 | } while (changed); | |
3106 | ||
3107 | return 0; | |
3108 | } | |
3109 | ||
942eb2e7 LP |
3110 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
3111 | DnsTransaction *dt; | |
942eb2e7 LP |
3112 | int r; |
3113 | ||
3114 | assert(t); | |
3115 | ||
3116 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
3117 | ||
90e74a66 | 3118 | SET_FOREACH(dt, t->dnssec_transactions) { |
942eb2e7 LP |
3119 | |
3120 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
3121 | continue; | |
3122 | ||
6f055e43 | 3123 | if (!FLAGS_SET(dt->answer_query_flags, SD_RESOLVED_AUTHENTICATED)) |
942eb2e7 LP |
3124 | continue; |
3125 | ||
3126 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
3127 | if (r < 0) | |
3128 | return r; | |
3129 | } | |
3130 | ||
3131 | return 0; | |
3132 | } | |
3133 | ||
c690b20a ZJS |
3134 | typedef enum { |
3135 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
3136 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
3137 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
3138 | } Phase; | |
3139 | ||
3140 | static int dnssec_validate_records( | |
3141 | DnsTransaction *t, | |
3142 | Phase phase, | |
3143 | bool *have_nsec, | |
3144 | DnsAnswer **validated) { | |
3145 | ||
547973de | 3146 | DnsResourceRecord *rr; |
56352fe9 | 3147 | int r; |
547973de | 3148 | |
c690b20a | 3149 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 3150 | |
c690b20a | 3151 | DNS_ANSWER_FOREACH(rr, t->answer) { |
71aee23d | 3152 | _unused_ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr_ref = dns_resource_record_ref(rr); |
c690b20a ZJS |
3153 | DnsResourceRecord *rrsig = NULL; |
3154 | DnssecResult result; | |
547973de | 3155 | |
c690b20a ZJS |
3156 | switch (rr->key->type) { |
3157 | case DNS_TYPE_RRSIG: | |
3158 | continue; | |
547973de | 3159 | |
c690b20a ZJS |
3160 | case DNS_TYPE_DNSKEY: |
3161 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
3162 | if (phase == DNSSEC_PHASE_NSEC) | |
3163 | continue; | |
3164 | break; | |
547973de | 3165 | |
c690b20a ZJS |
3166 | case DNS_TYPE_NSEC: |
3167 | case DNS_TYPE_NSEC3: | |
3168 | *have_nsec = true; | |
547973de | 3169 | |
c690b20a ZJS |
3170 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
3171 | if (phase == DNSSEC_PHASE_DNSKEY) | |
3172 | continue; | |
3173 | break; | |
105e1512 | 3174 | |
c690b20a ZJS |
3175 | default: |
3176 | /* We validate all other RRs only in the ALL phases */ | |
3177 | if (phase != DNSSEC_PHASE_ALL) | |
3178 | continue; | |
3179 | } | |
b652d4a2 | 3180 | |
04617bf8 LP |
3181 | r = dnssec_verify_rrset_search( |
3182 | t->answer, | |
3183 | rr->key, | |
3184 | t->validated_keys, | |
3185 | USEC_INFINITY, | |
3186 | &result, | |
3187 | &rrsig); | |
c690b20a ZJS |
3188 | if (r < 0) |
3189 | return r; | |
547973de | 3190 | |
c690b20a | 3191 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 3192 | |
c690b20a | 3193 | if (result == DNSSEC_VALIDATED) { |
04617bf8 | 3194 | assert(rrsig); |
942eb2e7 | 3195 | |
c690b20a ZJS |
3196 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
3197 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
3198 | * the set of validated keys for this transaction. */ | |
547973de | 3199 | |
04617bf8 | 3200 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED, rrsig); |
c690b20a ZJS |
3201 | if (r < 0) |
3202 | return r; | |
c9c72065 | 3203 | |
c690b20a ZJS |
3204 | /* Some of the DNSKEYs we just added might already have been revoked, |
3205 | * remove them again in that case. */ | |
3206 | r = dns_transaction_invalidate_revoked_keys(t); | |
3207 | if (r < 0) | |
3208 | return r; | |
3209 | } | |
547973de | 3210 | |
04617bf8 LP |
3211 | /* Add the validated RRset to the new list of validated RRsets, and remove it from |
3212 | * the unvalidated RRsets. We mark the RRset as authenticated and cacheable. */ | |
3213 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE, rrsig); | |
c690b20a ZJS |
3214 | if (r < 0) |
3215 | return r; | |
547973de | 3216 | |
c690b20a | 3217 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 3218 | |
c690b20a ZJS |
3219 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
3220 | return 1; | |
3221 | } | |
547973de | 3222 | |
c690b20a ZJS |
3223 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
3224 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
3225 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
3226 | if (phase != DNSSEC_PHASE_ALL) | |
3227 | continue; | |
0c7bff0a | 3228 | |
c690b20a ZJS |
3229 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
3230 | bool authenticated = false; | |
3231 | const char *source; | |
0c7bff0a | 3232 | |
04617bf8 LP |
3233 | assert(rrsig); |
3234 | ||
c690b20a | 3235 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 3236 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 3237 | |
c690b20a ZJS |
3238 | /* First step, determine the source of synthesis */ |
3239 | r = dns_resource_record_source(rrsig, &source); | |
3240 | if (r < 0) | |
3241 | return r; | |
0c7bff0a | 3242 | |
c690b20a | 3243 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 3244 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
3245 | source, |
3246 | rrsig->rrsig.signer, | |
3247 | &authenticated); | |
0c7bff0a | 3248 | |
c690b20a ZJS |
3249 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
3250 | if (r == 0) | |
3251 | result = DNSSEC_INVALID; | |
3252 | else { | |
04617bf8 LP |
3253 | r = dns_answer_move_by_key( |
3254 | validated, | |
3255 | &t->answer, | |
3256 | rr->key, | |
3257 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0, | |
3258 | rrsig); | |
c690b20a ZJS |
3259 | if (r < 0) |
3260 | return r; | |
3261 | ||
3262 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
3263 | ||
3264 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
3265 | return 1; | |
0c7bff0a | 3266 | } |
c690b20a | 3267 | } |
0c7bff0a | 3268 | |
c690b20a ZJS |
3269 | if (result == DNSSEC_NO_SIGNATURE) { |
3270 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
3271 | if (r < 0) |
3272 | return r; | |
c690b20a ZJS |
3273 | if (r == 0) { |
3274 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 3275 | * but remember that this is by no means authenticated. */ |
04617bf8 LP |
3276 | r = dns_answer_move_by_key( |
3277 | validated, | |
3278 | &t->answer, | |
3279 | rr->key, | |
3280 | 0, | |
3281 | NULL); | |
c690b20a ZJS |
3282 | if (r < 0) |
3283 | return r; | |
3284 | ||
3285 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
3286 | return 1; | |
3287 | } | |
547973de | 3288 | |
c690b20a ZJS |
3289 | r = dns_transaction_known_signed(t, rr); |
3290 | if (r < 0) | |
3291 | return r; | |
3292 | if (r > 0) { | |
3293 | /* This is an RR we know has to be signed. If it isn't this means | |
3294 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 3295 | |
c690b20a | 3296 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 3297 | |
c690b20a | 3298 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 3299 | |
c690b20a | 3300 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 3301 | |
04617bf8 | 3302 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
c9c72065 LP |
3303 | if (r < 0) |
3304 | return r; | |
547973de | 3305 | |
c690b20a ZJS |
3306 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3307 | return 1; | |
3308 | } | |
a150ff5e | 3309 | |
c690b20a ZJS |
3310 | /* Otherwise, fail */ |
3311 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
3312 | return 0; | |
f3cf586d | 3313 | } |
547973de | 3314 | |
c690b20a ZJS |
3315 | r = dns_transaction_in_private_tld(t, rr->key); |
3316 | if (r < 0) | |
3317 | return r; | |
3318 | if (r > 0) { | |
202b76ae | 3319 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 3320 | |
c690b20a ZJS |
3321 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
3322 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 3323 | |
202b76ae ZJS |
3324 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
3325 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 3326 | |
04617bf8 | 3327 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
0c7bff0a LP |
3328 | if (r < 0) |
3329 | return r; | |
0c7bff0a | 3330 | |
c690b20a ZJS |
3331 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3332 | return 1; | |
3333 | } | |
3334 | } | |
0c7bff0a | 3335 | |
c690b20a ZJS |
3336 | if (IN_SET(result, |
3337 | DNSSEC_MISSING_KEY, | |
3338 | DNSSEC_SIGNATURE_EXPIRED, | |
3339 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 3340 | |
c690b20a ZJS |
3341 | r = dns_transaction_dnskey_authenticated(t, rr); |
3342 | if (r < 0 && r != -ENXIO) | |
3343 | return r; | |
3344 | if (r == 0) { | |
3345 | /* The DNSKEY transaction was not authenticated, this means there's | |
3346 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 3347 | |
04617bf8 | 3348 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0, NULL); |
f3cf586d LP |
3349 | if (r < 0) |
3350 | return r; | |
b652d4a2 | 3351 | |
c690b20a ZJS |
3352 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3353 | return 1; | |
3354 | } | |
3355 | } | |
b652d4a2 | 3356 | |
c690b20a ZJS |
3357 | r = dns_transaction_is_primary_response(t, rr); |
3358 | if (r < 0) | |
3359 | return r; | |
3360 | if (r > 0) { | |
3361 | /* Look for a matching DNAME for this CNAME */ | |
3362 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
3363 | if (r < 0) | |
3364 | return r; | |
3365 | if (r == 0) { | |
3366 | /* Also look among the stuff we already validated */ | |
3367 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
3368 | if (r < 0) |
3369 | return r; | |
c690b20a | 3370 | } |
d33b6cf3 | 3371 | |
c690b20a ZJS |
3372 | if (r == 0) { |
3373 | if (IN_SET(result, | |
3374 | DNSSEC_INVALID, | |
3375 | DNSSEC_SIGNATURE_EXPIRED, | |
3376 | DNSSEC_NO_SIGNATURE)) | |
3377 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
3378 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
3379 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
3380 | ||
3381 | /* This is a primary response to our question, and it failed validation. | |
3382 | * That's fatal. */ | |
3383 | t->answer_dnssec_result = result; | |
3384 | return 0; | |
3385 | } | |
d33b6cf3 | 3386 | |
c690b20a ZJS |
3387 | /* This is a primary response, but we do have a DNAME RR |
3388 | * in the RR that can replay this CNAME, hence rely on | |
3389 | * that, and we can remove the CNAME in favour of it. */ | |
3390 | } | |
d33b6cf3 | 3391 | |
c690b20a ZJS |
3392 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
3393 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
3394 | if (r < 0) | |
3395 | return r; | |
d33b6cf3 | 3396 | |
c690b20a ZJS |
3397 | /* We dropped something from the answer, start from the beginning. */ |
3398 | return 1; | |
3399 | } | |
f3cf586d | 3400 | |
c690b20a ZJS |
3401 | return 2; /* Finito. */ |
3402 | } | |
94aa7071 | 3403 | |
c690b20a ZJS |
3404 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
3405 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
3406 | Phase phase; | |
3407 | DnsAnswerFlags flags; | |
3408 | int r; | |
202b76ae | 3409 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 3410 | |
c690b20a | 3411 | assert(t); |
94aa7071 | 3412 | |
775ae354 | 3413 | /* We have now collected all DS and DNSKEY RRs in t->validated_keys, let's see which RRs we can now |
c690b20a | 3414 | * authenticate with that. */ |
94aa7071 | 3415 | |
775ae354 | 3416 | if (FLAGS_SET(t->query_flags, SD_RESOLVED_NO_VALIDATE) || t->scope->dnssec_mode == DNSSEC_NO) |
c690b20a | 3417 | return 0; |
a150ff5e | 3418 | |
c690b20a ZJS |
3419 | /* Already validated */ |
3420 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
3421 | return 0; | |
105e1512 | 3422 | |
c690b20a ZJS |
3423 | /* Our own stuff needs no validation */ |
3424 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
3425 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
6f055e43 | 3426 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, true); |
c690b20a ZJS |
3427 | return 0; |
3428 | } | |
a150ff5e | 3429 | |
c690b20a ZJS |
3430 | /* Cached stuff is not affected by validation. */ |
3431 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
3432 | return 0; | |
f3cf586d | 3433 | |
c690b20a ZJS |
3434 | if (!dns_transaction_dnssec_supported_full(t)) { |
3435 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3436 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3437 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3438 | return 0; |
3439 | } | |
f3cf586d | 3440 | |
202b76ae ZJS |
3441 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3442 | t->id, | |
42df9532 | 3443 | dns_resource_key_to_string(dns_transaction_key(t), key_str, sizeof key_str)); |
547973de | 3444 | |
c690b20a ZJS |
3445 | /* First, see if this response contains any revoked trust |
3446 | * anchors we care about */ | |
3447 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3448 | if (r < 0) | |
3449 | return r; | |
43e6779a | 3450 | |
c690b20a ZJS |
3451 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3452 | r = dns_transaction_copy_validated(t); | |
3453 | if (r < 0) | |
3454 | return r; | |
43e6779a | 3455 | |
c690b20a ZJS |
3456 | /* Second, see if there are DNSKEYs we already know a |
3457 | * validated DS for. */ | |
3458 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3459 | if (r < 0) | |
3460 | return r; | |
43e6779a | 3461 | |
c690b20a ZJS |
3462 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3463 | * anchor says are revoked. After all we might have marked | |
3464 | * some keys revoked above, but they might still be lingering | |
3465 | * in our validated_keys list. */ | |
3466 | r = dns_transaction_invalidate_revoked_keys(t); | |
3467 | if (r < 0) | |
3468 | return r; | |
f3cf586d | 3469 | |
c690b20a ZJS |
3470 | phase = DNSSEC_PHASE_DNSKEY; |
3471 | for (;;) { | |
3472 | bool have_nsec = false; | |
f3cf586d | 3473 | |
c690b20a ZJS |
3474 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3475 | if (r <= 0) | |
3476 | return r; | |
547973de | 3477 | |
c690b20a ZJS |
3478 | /* Try again as long as we managed to achieve something */ |
3479 | if (r == 1) | |
547973de LP |
3480 | continue; |
3481 | ||
c690b20a | 3482 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3483 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3484 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3485 | continue; |
3486 | } | |
3487 | ||
c690b20a ZJS |
3488 | if (phase != DNSSEC_PHASE_ALL) { |
3489 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3490 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3491 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3492 | continue; |
547973de LP |
3493 | } |
3494 | ||
56352fe9 | 3495 | /* We're done */ |
547973de LP |
3496 | break; |
3497 | } | |
3498 | ||
1117a960 | 3499 | DNS_ANSWER_REPLACE(t->answer, TAKE_PTR(validated)); |
547973de | 3500 | |
72667f08 LP |
3501 | /* At this point the answer only contains validated |
3502 | * RRsets. Now, let's see if it actually answers the question | |
3503 | * we asked. If so, great! If it doesn't, then see if | |
3504 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3505 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3506 | if (r > 0) { |
105e1512 LP |
3507 | /* Yes, it answers the question! */ |
3508 | ||
3509 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3510 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3511 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 | 3512 | t->answer_rcode = DNS_RCODE_SUCCESS; |
6f055e43 | 3513 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, true); |
105e1512 LP |
3514 | } else { |
3515 | /* The answer is not fully authenticated. */ | |
019036a4 | 3516 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3517 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
105e1512 LP |
3518 | } |
3519 | ||
72667f08 LP |
3520 | } else if (r == 0) { |
3521 | DnssecNsecResult nr; | |
ed29bfdc | 3522 | bool authenticated = false; |
72667f08 LP |
3523 | |
3524 | /* Bummer! Let's check NSEC/NSEC3 */ | |
42df9532 | 3525 | r = dnssec_nsec_test(t->answer, dns_transaction_key(t), &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3526 | if (r < 0) |
3527 | return r; | |
3528 | ||
3529 | switch (nr) { | |
3530 | ||
3531 | case DNSSEC_NSEC_NXDOMAIN: | |
3532 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3533 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3534 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3535 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
6f055e43 | 3536 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, authenticated); |
7aa8ce98 | 3537 | |
42df9532 | 3538 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3539 | break; |
3540 | ||
3541 | case DNSSEC_NSEC_NODATA: | |
3542 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3543 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3544 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3545 | t->answer_rcode = DNS_RCODE_SUCCESS; |
6f055e43 | 3546 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, authenticated); |
7aa8ce98 | 3547 | |
42df9532 | 3548 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, dns_transaction_key(t)); |
72667f08 LP |
3549 | break; |
3550 | ||
105e1512 LP |
3551 | case DNSSEC_NSEC_OPTOUT: |
3552 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3553 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3554 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3555 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
7aa8ce98 | 3556 | |
42df9532 | 3557 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3558 | break; |
3559 | ||
72667f08 LP |
3560 | case DNSSEC_NSEC_NO_RR: |
3561 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3562 | |
3563 | r = dns_transaction_requires_nsec(t); | |
3564 | if (r < 0) | |
3565 | return r; | |
7aa8ce98 | 3566 | if (r > 0) { |
019036a4 | 3567 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
42df9532 | 3568 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
7aa8ce98 | 3569 | } else { |
019036a4 | 3570 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
6f055e43 | 3571 | SET_FLAG(t->answer_query_flags, SD_RESOLVED_AUTHENTICATED, false); |
42df9532 | 3572 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, dns_transaction_key(t)); |
105e1512 LP |
3573 | } |
3574 | ||
3575 | break; | |
3576 | ||
3577 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3578 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3579 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
42df9532 | 3580 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, dns_transaction_key(t)); |
72667f08 LP |
3581 | break; |
3582 | ||
3583 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3584 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3585 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3586 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
42df9532 | 3587 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, dns_transaction_key(t)); |
72667f08 LP |
3588 | break; |
3589 | ||
3590 | default: | |
04499a70 | 3591 | assert_not_reached(); |
72667f08 LP |
3592 | } |
3593 | } | |
3594 | ||
547973de LP |
3595 | return 1; |
3596 | } | |
3597 | ||
ec2c5e43 | 3598 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
e3e64a1a ZJS |
3599 | [DNS_TRANSACTION_NULL] = "null", |
3600 | [DNS_TRANSACTION_PENDING] = "pending", | |
3601 | [DNS_TRANSACTION_VALIDATING] = "validating", | |
3602 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", | |
3603 | [DNS_TRANSACTION_SUCCESS] = "success", | |
3604 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3605 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
ec2c5e43 | 3606 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", |
e3e64a1a ZJS |
3607 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", |
3608 | [DNS_TRANSACTION_ERRNO] = "errno", | |
3609 | [DNS_TRANSACTION_ABORTED] = "aborted", | |
3610 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", | |
3611 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", | |
3612 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", | |
3613 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", | |
3614 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", | |
3615 | [DNS_TRANSACTION_NO_SOURCE] = "no-source", | |
3616 | [DNS_TRANSACTION_STUB_LOOP] = "stub-loop", | |
ec2c5e43 LP |
3617 | }; |
3618 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3619 | |
3620 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
e3e64a1a ZJS |
3621 | [DNS_TRANSACTION_NETWORK] = "network", |
3622 | [DNS_TRANSACTION_CACHE] = "cache", | |
3623 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3624 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3625 | }; |
3626 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |