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Commit | Line | Data |
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ec2c5e43 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2014 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
beef6a5f LP |
20 | #include <sd-messages.h> |
21 | ||
ec2c5e43 | 22 | #include "af-list.h" |
b5efdb8a | 23 | #include "alloc-util.h" |
f52e61da | 24 | #include "dns-domain.h" |
7cc6ed7b | 25 | #include "errno-list.h" |
3ffd4af2 LP |
26 | #include "fd-util.h" |
27 | #include "random-util.h" | |
7778dfff | 28 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
29 | #include "resolved-dns-transaction.h" |
30 | #include "resolved-llmnr.h" | |
8b43440b | 31 | #include "string-table.h" |
ec2c5e43 | 32 | |
b214dc0f LP |
33 | #define TRANSACTIONS_MAX 4096 |
34 | ||
c61d2b44 LP |
35 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
36 | assert(t); | |
37 | ||
38 | t->received = dns_packet_unref(t->received); | |
39 | t->answer = dns_answer_unref(t->answer); | |
40 | t->answer_rcode = 0; | |
41 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
42 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
43 | t->answer_authenticated = false; | |
d3760be0 | 44 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 45 | t->answer_errno = 0; |
c61d2b44 LP |
46 | } |
47 | ||
c5b4f861 LP |
48 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
49 | DnsTransaction *z; | |
50 | ||
51 | assert(t); | |
52 | ||
53 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
54 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 55 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
56 | dns_transaction_gc(z); |
57 | } | |
58 | } | |
59 | ||
f32f0e57 LP |
60 | static void dns_transaction_close_connection(DnsTransaction *t) { |
61 | assert(t); | |
62 | ||
b30bf55d LP |
63 | if (t->stream) { |
64 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
65 | t->stream->complete = NULL; | |
66 | t->stream->on_packet = NULL; | |
67 | t->stream->transaction = NULL; | |
68 | t->stream = dns_stream_unref(t->stream); | |
69 | } | |
70 | ||
f32f0e57 LP |
71 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
72 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
73 | } | |
74 | ||
f535705a | 75 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
76 | assert(t); |
77 | ||
78 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
79 | } |
80 | ||
ec2c5e43 | 81 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 82 | DnsQueryCandidate *c; |
ec2c5e43 | 83 | DnsZoneItem *i; |
547973de | 84 | DnsTransaction *z; |
ec2c5e43 LP |
85 | |
86 | if (!t) | |
87 | return NULL; | |
88 | ||
51e399bc LP |
89 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
90 | ||
f32f0e57 | 91 | dns_transaction_close_connection(t); |
f535705a | 92 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 93 | |
ec2c5e43 | 94 | dns_packet_unref(t->sent); |
c61d2b44 | 95 | dns_transaction_reset_answer(t); |
ec2c5e43 | 96 | |
8300ba21 | 97 | dns_server_unref(t->server); |
ec2c5e43 LP |
98 | |
99 | if (t->scope) { | |
f9ebb22a LP |
100 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
101 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
102 | |
103 | if (t->id != 0) | |
104 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
105 | } | |
106 | ||
547973de | 107 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 108 | set_remove(c->transactions, t); |
547973de | 109 | set_free(t->notify_query_candidates); |
801ad6a6 | 110 | |
35aa04e9 LP |
111 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
112 | set_remove(c->transactions, t); | |
113 | set_free(t->notify_query_candidates_done); | |
114 | ||
547973de | 115 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 116 | i->probe_transaction = NULL; |
547973de LP |
117 | set_free(t->notify_zone_items); |
118 | ||
35aa04e9 LP |
119 | while ((i = set_steal_first(t->notify_zone_items_done))) |
120 | i->probe_transaction = NULL; | |
121 | set_free(t->notify_zone_items_done); | |
122 | ||
547973de LP |
123 | while ((z = set_steal_first(t->notify_transactions))) |
124 | set_remove(z->dnssec_transactions, t); | |
125 | set_free(t->notify_transactions); | |
126 | ||
35aa04e9 LP |
127 | while ((z = set_steal_first(t->notify_transactions_done))) |
128 | set_remove(z->dnssec_transactions, t); | |
129 | set_free(t->notify_transactions_done); | |
130 | ||
c5b4f861 | 131 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
132 | set_free(t->dnssec_transactions); |
133 | ||
134 | dns_answer_unref(t->validated_keys); | |
97cc656c | 135 | dns_resource_key_unref(t->key); |
97cc656c | 136 | |
6b430fdb | 137 | return mfree(t); |
ec2c5e43 LP |
138 | } |
139 | ||
140 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
141 | ||
51e399bc | 142 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
143 | assert(t); |
144 | ||
145 | if (t->block_gc > 0) | |
51e399bc | 146 | return true; |
ec2c5e43 | 147 | |
547973de | 148 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 149 | set_isempty(t->notify_query_candidates_done) && |
547973de | 150 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
151 | set_isempty(t->notify_zone_items_done) && |
152 | set_isempty(t->notify_transactions) && | |
153 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 154 | dns_transaction_free(t); |
51e399bc LP |
155 | return false; |
156 | } | |
157 | ||
158 | return true; | |
ec2c5e43 LP |
159 | } |
160 | ||
4dd15077 LP |
161 | static uint16_t pick_new_id(Manager *m) { |
162 | uint16_t new_id; | |
163 | ||
164 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
165 | * transactions, and it's much lower than the space of IDs. */ | |
166 | ||
167 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
168 | ||
169 | do | |
170 | random_bytes(&new_id, sizeof(new_id)); | |
171 | while (new_id == 0 || | |
172 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
173 | ||
174 | return new_id; | |
175 | } | |
176 | ||
f52e61da | 177 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
178 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
179 | int r; | |
180 | ||
181 | assert(ret); | |
182 | assert(s); | |
f52e61da | 183 | assert(key); |
ec2c5e43 | 184 | |
9eae2bf3 | 185 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 186 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 187 | return -EINVAL; |
d0129ddb LP |
188 | if (dns_type_is_obsolete(key->type)) |
189 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
190 | |
191 | /* We only support the IN class */ | |
c463eb78 | 192 | if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) |
9eae2bf3 LP |
193 | return -EOPNOTSUPP; |
194 | ||
b214dc0f LP |
195 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
196 | return -EBUSY; | |
197 | ||
d5099efc | 198 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
199 | if (r < 0) |
200 | return r; | |
201 | ||
f9ebb22a | 202 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
203 | if (r < 0) |
204 | return r; | |
205 | ||
ec2c5e43 LP |
206 | t = new0(DnsTransaction, 1); |
207 | if (!t) | |
208 | return -ENOMEM; | |
209 | ||
4667e00a | 210 | t->dns_udp_fd = -1; |
c3bc53e6 | 211 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 212 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 213 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 214 | t->key = dns_resource_key_ref(key); |
274b8748 | 215 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
d001e0a3 | 216 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 217 | |
4dd15077 | 218 | t->id = pick_new_id(s->manager); |
ec2c5e43 LP |
219 | |
220 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
221 | if (r < 0) { | |
222 | t->id = 0; | |
223 | return r; | |
224 | } | |
225 | ||
f9ebb22a | 226 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
227 | if (r < 0) { |
228 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
229 | return r; | |
230 | } | |
231 | ||
f9ebb22a | 232 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
233 | t->scope = s; |
234 | ||
313cefa1 | 235 | s->manager->n_transactions_total++; |
a150ff5e | 236 | |
ec2c5e43 LP |
237 | if (ret) |
238 | *ret = t; | |
239 | ||
240 | t = NULL; | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
4dd15077 LP |
245 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
246 | uint16_t new_id; | |
247 | assert(t); | |
248 | ||
249 | /* Pick a new ID for this transaction. */ | |
250 | ||
251 | new_id = pick_new_id(t->scope->manager); | |
252 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
253 | ||
254 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
255 | t->id = new_id; | |
256 | ||
257 | /* Make sure we generate a new packet with the new ID */ | |
258 | t->sent = dns_packet_unref(t->sent); | |
259 | } | |
260 | ||
ec2c5e43 | 261 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 262 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 263 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 264 | DnsZoneItem *z; |
ec2c5e43 LP |
265 | |
266 | assert(t); | |
267 | assert(p); | |
268 | ||
269 | if (manager_our_packet(t->scope->manager, p) != 0) | |
270 | return; | |
271 | ||
164d025d | 272 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 273 | |
a5784c49 LP |
274 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
275 | t->id, | |
202b76ae | 276 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
277 | dns_protocol_to_string(t->scope->protocol), |
278 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 279 | af_to_name_short(t->scope->family), |
164d025d | 280 | strnull(pretty)); |
ec2c5e43 | 281 | |
a4076574 LP |
282 | /* RFC 4795, Section 4.1 says that the peer with the |
283 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
284 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
285 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
286 | return; |
287 | } | |
288 | ||
4d91eec4 | 289 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 290 | |
ec2c5e43 | 291 | t->block_gc++; |
35aa04e9 | 292 | |
547973de | 293 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
294 | /* First, make sure the zone item drops the reference |
295 | * to us */ | |
296 | dns_zone_item_probe_stop(z); | |
297 | ||
298 | /* Secondly, report this as conflict, so that we might | |
299 | * look for a different hostname */ | |
ec2c5e43 | 300 | dns_zone_item_conflict(z); |
3ef64445 | 301 | } |
ec2c5e43 LP |
302 | t->block_gc--; |
303 | ||
304 | dns_transaction_gc(t); | |
305 | } | |
306 | ||
307 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 308 | DnsQueryCandidate *c; |
ec2c5e43 | 309 | DnsZoneItem *z; |
547973de | 310 | DnsTransaction *d; |
7cc6ed7b | 311 | const char *st; |
202b76ae | 312 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
313 | |
314 | assert(t); | |
547973de | 315 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 316 | |
202b76ae ZJS |
317 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
318 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
319 | ||
f61dfddb | 320 | log_struct(LOG_NOTICE, |
beef6a5f | 321 | LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), |
202b76ae | 322 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 323 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 324 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 325 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
1e02e182 LP |
326 | "DNS_SERVER=%s", dns_server_string(t->server), |
327 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level), | |
f61dfddb | 328 | NULL); |
202b76ae | 329 | } |
f61dfddb | 330 | |
ec2c5e43 LP |
331 | /* Note that this call might invalidate the query. Callers |
332 | * should hence not attempt to access the query or transaction | |
333 | * after calling this function. */ | |
334 | ||
7cc6ed7b LP |
335 | if (state == DNS_TRANSACTION_ERRNO) |
336 | st = errno_to_name(t->answer_errno); | |
337 | else | |
338 | st = dns_transaction_state_to_string(state); | |
339 | ||
a5784c49 LP |
340 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
341 | t->id, | |
202b76ae | 342 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
343 | dns_protocol_to_string(t->scope->protocol), |
344 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 345 | af_to_name_short(t->scope->family), |
7cc6ed7b | 346 | st, |
a5784c49 LP |
347 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
348 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
349 | |
350 | t->state = state; | |
351 | ||
f32f0e57 | 352 | dns_transaction_close_connection(t); |
f535705a | 353 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
354 | |
355 | /* Notify all queries that are interested, but make sure the | |
356 | * transaction isn't freed while we are still looking at it */ | |
357 | t->block_gc++; | |
f7014757 | 358 | |
35aa04e9 | 359 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 360 | dns_query_candidate_notify(c); |
35aa04e9 | 361 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 362 | |
35aa04e9 LP |
363 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
364 | dns_zone_item_notify(z); | |
365 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
c3ae4188 DR |
366 | if (t->probing) |
367 | dns_scope_announce(t->scope, false); | |
f7014757 | 368 | |
35aa04e9 LP |
369 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
370 | dns_transaction_notify(d, t); | |
371 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
372 | |
373 | t->block_gc--; | |
ec2c5e43 LP |
374 | dns_transaction_gc(t); |
375 | } | |
376 | ||
519ef046 LP |
377 | static int dns_transaction_pick_server(DnsTransaction *t) { |
378 | DnsServer *server; | |
379 | ||
380 | assert(t); | |
381 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
382 | ||
d001e0a3 LP |
383 | /* Pick a DNS server and a feature level for it. */ |
384 | ||
519ef046 LP |
385 | server = dns_scope_get_dns_server(t->scope); |
386 | if (!server) | |
387 | return -ESRCH; | |
388 | ||
d001e0a3 LP |
389 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
390 | * different properties. */ | |
391 | if (server != t->server) | |
392 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
393 | ||
274b8748 | 394 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 395 | |
d001e0a3 LP |
396 | /* Clamp the feature level if that is requested. */ |
397 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
398 | t->current_feature_level > t->clamp_feature_level) | |
399 | t->current_feature_level = t->clamp_feature_level; | |
400 | ||
401 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
402 | ||
519ef046 LP |
403 | if (server == t->server) |
404 | return 0; | |
405 | ||
406 | dns_server_unref(t->server); | |
407 | t->server = dns_server_ref(server); | |
408 | ||
d001e0a3 LP |
409 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
410 | ||
519ef046 LP |
411 | return 1; |
412 | } | |
413 | ||
d001e0a3 | 414 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
415 | int r; |
416 | ||
417 | assert(t); | |
418 | ||
419 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
420 | ||
421 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
422 | if (next_server) |
423 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
424 | |
425 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
426 | if (r < 0) { |
427 | t->answer_errno = -r; | |
428 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
429 | } | |
8d10d620 LP |
430 | } |
431 | ||
c02cf2f4 | 432 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
433 | int r; |
434 | ||
c02cf2f4 LP |
435 | assert(t); |
436 | ||
5278bbfe LP |
437 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
438 | ||
c02cf2f4 LP |
439 | if (!t->server) |
440 | return 0; | |
441 | ||
442 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
443 | return 0; | |
444 | ||
445 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
446 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
447 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
448 | OPT RR or DO bit. One of these cases is documented here, for example: | |
449 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
450 | ||
4dd15077 LP |
451 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
452 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
453 | |
454 | r = dns_transaction_go(t); | |
455 | if (r < 0) | |
456 | return r; | |
457 | ||
458 | return 1; | |
c02cf2f4 LP |
459 | } |
460 | ||
ec2c5e43 LP |
461 | static int on_stream_complete(DnsStream *s, int error) { |
462 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
463 | DnsTransaction *t; | |
464 | ||
465 | assert(s); | |
466 | assert(s->transaction); | |
467 | ||
468 | /* Copy the data we care about out of the stream before we | |
469 | * destroy it. */ | |
470 | t = s->transaction; | |
471 | p = dns_packet_ref(s->read_packet); | |
472 | ||
b30bf55d | 473 | dns_transaction_close_connection(t); |
ec2c5e43 | 474 | |
a1a3f73a LP |
475 | if (ERRNO_IS_DISCONNECT(error)) { |
476 | usec_t usec; | |
477 | ||
0791110f LP |
478 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
479 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
480 | * question on this scope. */ | |
481 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
482 | return 0; | |
483 | } | |
484 | ||
92ec902a | 485 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 486 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 487 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a | 488 | |
d001e0a3 | 489 | dns_transaction_retry(t, true); |
ac720200 LP |
490 | return 0; |
491 | } | |
ec2c5e43 | 492 | if (error != 0) { |
7cc6ed7b LP |
493 | t->answer_errno = error; |
494 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
495 | return 0; |
496 | } | |
497 | ||
a4076574 | 498 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 499 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
500 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
501 | return 0; | |
502 | } | |
503 | ||
504 | dns_scope_check_conflicts(t->scope, p); | |
505 | ||
ec2c5e43 LP |
506 | t->block_gc++; |
507 | dns_transaction_process_reply(t, p); | |
508 | t->block_gc--; | |
509 | ||
519ef046 LP |
510 | /* If the response wasn't useful, then complete the transition |
511 | * now. After all, we are the worst feature set now with TCP | |
512 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
513 | if (t->state == DNS_TRANSACTION_PENDING) |
514 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
515 | else |
516 | dns_transaction_gc(t); | |
ec2c5e43 LP |
517 | |
518 | return 0; | |
519 | } | |
520 | ||
521 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
522 | _cleanup_close_ int fd = -1; | |
523 | int r; | |
524 | ||
525 | assert(t); | |
526 | ||
519ef046 | 527 | dns_transaction_close_connection(t); |
ec2c5e43 | 528 | |
106784eb | 529 | switch (t->scope->protocol) { |
519ef046 | 530 | |
106784eb | 531 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
532 | r = dns_transaction_pick_server(t); |
533 | if (r < 0) | |
534 | return r; | |
535 | ||
92ec902a | 536 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
537 | return -EOPNOTSUPP; |
538 | ||
274b8748 | 539 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
540 | if (r < 0) |
541 | return r; | |
542 | ||
543 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 544 | break; |
ec2c5e43 | 545 | |
106784eb | 546 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 547 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 548 | if (t->received) |
519ef046 | 549 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
550 | else { |
551 | union in_addr_union address; | |
a7f7d1bd | 552 | int family = AF_UNSPEC; |
ec2c5e43 LP |
553 | |
554 | /* Otherwise, try to talk to the owner of a | |
555 | * the IP address, in case this is a reverse | |
556 | * PTR lookup */ | |
f52e61da | 557 | |
1c02e7ba | 558 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
559 | if (r < 0) |
560 | return r; | |
561 | if (r == 0) | |
562 | return -EINVAL; | |
9e08a6e0 | 563 | if (family != t->scope->family) |
9318cdd3 | 564 | return -ESRCH; |
ec2c5e43 | 565 | |
519ef046 | 566 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 567 | } |
106784eb DM |
568 | |
569 | break; | |
570 | ||
571 | default: | |
ec2c5e43 | 572 | return -EAFNOSUPPORT; |
106784eb | 573 | } |
ec2c5e43 LP |
574 | |
575 | if (fd < 0) | |
576 | return fd; | |
577 | ||
578 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
579 | if (r < 0) | |
580 | return r; | |
ec2c5e43 LP |
581 | fd = -1; |
582 | ||
583 | r = dns_stream_write_packet(t->stream, t->sent); | |
584 | if (r < 0) { | |
b30bf55d | 585 | t->stream = dns_stream_unref(t->stream); |
ec2c5e43 LP |
586 | return r; |
587 | } | |
588 | ||
ec2c5e43 LP |
589 | t->stream->complete = on_stream_complete; |
590 | t->stream->transaction = t; | |
591 | ||
592 | /* The interface index is difficult to determine if we are | |
593 | * connecting to the local host, hence fill this in right away | |
594 | * instead of determining it from the socket */ | |
97ebebbc | 595 | t->stream->ifindex = dns_scope_ifindex(t->scope); |
ec2c5e43 | 596 | |
519ef046 LP |
597 | dns_transaction_reset_answer(t); |
598 | ||
cbe4216d LP |
599 | t->tried_stream = true; |
600 | ||
ec2c5e43 LP |
601 | return 0; |
602 | } | |
603 | ||
547973de | 604 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
605 | assert(t); |
606 | ||
607 | /* For mDNS we cache whenever we get the packet, rather than | |
608 | * in each transaction. */ | |
609 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
610 | return; | |
611 | ||
ceeddf79 MP |
612 | /* Caching disabled? */ |
613 | if (!t->scope->manager->enable_cache) | |
614 | return; | |
615 | ||
547973de LP |
616 | /* We never cache if this packet is from the local host, under |
617 | * the assumption that a locally running DNS server would | |
618 | * cache this anyway, and probably knows better when to flush | |
619 | * the cache then we could. */ | |
620 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
621 | return; | |
622 | ||
547973de LP |
623 | dns_cache_put(&t->scope->cache, |
624 | t->key, | |
625 | t->answer_rcode, | |
626 | t->answer, | |
547973de | 627 | t->answer_authenticated, |
d3760be0 | 628 | t->answer_nsec_ttl, |
547973de LP |
629 | 0, |
630 | t->received->family, | |
631 | &t->received->sender); | |
632 | } | |
633 | ||
105e1512 LP |
634 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
635 | DnsTransaction *dt; | |
636 | Iterator i; | |
637 | ||
638 | assert(t); | |
639 | ||
640 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
641 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
642 | return true; | |
643 | ||
644 | return false; | |
645 | } | |
646 | ||
942eb2e7 LP |
647 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
648 | DnsTransaction *dt; | |
649 | Iterator i; | |
650 | ||
651 | assert(t); | |
652 | ||
653 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
654 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
655 | ||
656 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
657 | ||
658 | switch (dt->state) { | |
659 | ||
660 | case DNS_TRANSACTION_NULL: | |
661 | case DNS_TRANSACTION_PENDING: | |
662 | case DNS_TRANSACTION_VALIDATING: | |
663 | /* Still ongoing */ | |
664 | return 0; | |
665 | ||
666 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 667 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
668 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
669 | goto fail; | |
670 | } | |
671 | ||
b3c6b00a LP |
672 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
673 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
674 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
675 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
676 | |
677 | case DNS_TRANSACTION_SUCCESS: | |
678 | /* All good. */ | |
679 | break; | |
680 | ||
681 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
682 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
683 | * validationr result */ | |
684 | ||
685 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
686 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
687 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
688 | return 0; | |
689 | ||
690 | ||
691 | default: | |
692 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
693 | goto fail; | |
694 | } | |
695 | } | |
696 | ||
697 | /* All is ready, we can go and validate */ | |
698 | return 1; | |
699 | ||
700 | fail: | |
701 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
702 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
703 | return 0; | |
704 | } | |
705 | ||
547973de LP |
706 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
707 | int r; | |
708 | ||
709 | assert(t); | |
710 | ||
711 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 712 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
713 | if (r < 0) |
714 | goto fail; | |
942eb2e7 | 715 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
716 | return; |
717 | ||
c02cf2f4 LP |
718 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
719 | * restart the lookup immediately. */ | |
720 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
721 | if (r < 0) |
722 | goto fail; | |
c02cf2f4 LP |
723 | if (r > 0) /* Transaction got restarted... */ |
724 | return; | |
725 | ||
547973de LP |
726 | /* All our auxiliary DNSSEC transactions are complete now. Try |
727 | * to validate our RRset now. */ | |
728 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
729 | if (r == -EBADMSG) { |
730 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
731 | return; | |
732 | } | |
7cc6ed7b LP |
733 | if (r < 0) |
734 | goto fail; | |
547973de | 735 | |
b652d4a2 LP |
736 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
737 | t->scope->dnssec_mode == DNSSEC_YES) { | |
738 | /* We are not in automatic downgrade mode, and the | |
739 | * server is bad, refuse operation. */ | |
740 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
741 | return; | |
742 | } | |
743 | ||
019036a4 | 744 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
745 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
746 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
747 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
748 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
749 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
750 | return; | |
751 | } | |
752 | ||
1e02e182 LP |
753 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
754 | dns_server_warn_downgrade(t->server); | |
755 | ||
547973de LP |
756 | dns_transaction_cache_answer(t); |
757 | ||
758 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
759 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
760 | else | |
3bbdc31d | 761 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
762 | |
763 | return; | |
764 | ||
765 | fail: | |
766 | t->answer_errno = -r; | |
767 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
768 | } |
769 | ||
eac7cda2 LP |
770 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
771 | int r; | |
772 | ||
773 | assert(t); | |
774 | ||
775 | /* Checks whether the answer is positive, i.e. either a direct | |
776 | * answer to the question, or a CNAME/DNAME for it */ | |
777 | ||
778 | r = dns_answer_match_key(t->answer, t->key, flags); | |
779 | if (r != 0) | |
780 | return r; | |
781 | ||
782 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
783 | if (r != 0) | |
784 | return r; | |
785 | ||
786 | return false; | |
787 | } | |
788 | ||
789 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
790 | int r; | |
791 | ||
792 | assert(t); | |
793 | ||
794 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
795 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
796 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
797 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
798 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
799 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
800 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
801 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
802 | * incomplete CNAME/DNAME chain. | |
803 | * | |
804 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
805 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
806 | * lookup. */ | |
807 | ||
808 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
809 | return 0; | |
810 | ||
811 | r = dns_transaction_has_positive_answer(t, NULL); | |
812 | if (r <= 0) | |
813 | return r; | |
814 | ||
815 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
816 | return 0; | |
817 | } | |
818 | ||
ec2c5e43 | 819 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 820 | usec_t ts; |
ec2c5e43 LP |
821 | int r; |
822 | ||
823 | assert(t); | |
824 | assert(p); | |
9df3ba6c TG |
825 | assert(t->scope); |
826 | assert(t->scope->manager); | |
ec2c5e43 | 827 | |
5a7e41a3 LP |
828 | if (t->state != DNS_TRANSACTION_PENDING) |
829 | return; | |
830 | ||
ec2c5e43 LP |
831 | /* Note that this call might invalidate the query. Callers |
832 | * should hence not attempt to access the query or transaction | |
833 | * after calling this function. */ | |
834 | ||
b5efcf29 LP |
835 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
836 | ||
106784eb | 837 | switch (t->scope->protocol) { |
b5efcf29 | 838 | |
106784eb | 839 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 840 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 841 | |
97ebebbc | 842 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
843 | return; |
844 | ||
845 | if (p->family != t->scope->family) | |
846 | return; | |
847 | ||
848 | /* Tentative packets are not full responses but still | |
849 | * useful for identifying uniqueness conflicts during | |
850 | * probing. */ | |
8b757a38 | 851 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
852 | dns_transaction_tentative(t, p); |
853 | return; | |
854 | } | |
106784eb DM |
855 | |
856 | break; | |
857 | ||
4e5bf5e1 | 858 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 859 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
860 | |
861 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
862 | return; |
863 | ||
864 | if (p->family != t->scope->family) | |
865 | return; | |
866 | ||
867 | break; | |
868 | ||
106784eb | 869 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
870 | /* Note that we do not need to verify the |
871 | * addresses/port numbers of incoming traffic, as we | |
872 | * invoked connect() on our UDP socket in which case | |
873 | * the kernel already does the needed verification for | |
874 | * us. */ | |
106784eb DM |
875 | break; |
876 | ||
877 | default: | |
9c56a6f3 | 878 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
879 | } |
880 | ||
ec2c5e43 LP |
881 | if (t->received != p) { |
882 | dns_packet_unref(t->received); | |
883 | t->received = dns_packet_ref(p); | |
884 | } | |
885 | ||
c3bc53e6 LP |
886 | t->answer_source = DNS_TRANSACTION_NETWORK; |
887 | ||
ec2c5e43 LP |
888 | if (p->ipproto == IPPROTO_TCP) { |
889 | if (DNS_PACKET_TC(p)) { | |
890 | /* Truncated via TCP? Somebody must be fucking with us */ | |
891 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
892 | return; | |
893 | } | |
894 | ||
895 | if (DNS_PACKET_ID(p) != t->id) { | |
896 | /* Not the reply to our query? Somebody must be fucking with us */ | |
897 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
898 | return; | |
899 | } | |
900 | } | |
901 | ||
38a03f06 | 902 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
903 | |
904 | switch (t->scope->protocol) { | |
8af5b883 | 905 | |
9df3ba6c TG |
906 | case DNS_PROTOCOL_DNS: |
907 | assert(t->server); | |
908 | ||
4e0b8b17 TG |
909 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
910 | ||
8af5b883 | 911 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 912 | |
d001e0a3 LP |
913 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_WORST) { |
914 | /* This was already at the lowest possible feature level? If so, we can't downgrade | |
915 | * this transaction anymore, hence let's process the response, and accept the rcode. */ | |
916 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); | |
917 | break; | |
918 | } | |
919 | ||
920 | /* Reduce this feature level by one and try again. */ | |
921 | t->clamp_feature_level = t->current_feature_level - 1; | |
922 | ||
923 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
924 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
925 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
926 | ||
927 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 928 | return; |
eb08640a LP |
929 | } |
930 | ||
931 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
932 | /* This server refused our request? If so, try again, use a different server */ | |
933 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
934 | dns_transaction_retry(t, true /* pick a new server */); | |
935 | return; | |
936 | } | |
937 | ||
938 | if (DNS_PACKET_TC(p)) | |
274b8748 | 939 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
940 | |
941 | break; | |
8af5b883 | 942 | |
9df3ba6c TG |
943 | case DNS_PROTOCOL_LLMNR: |
944 | case DNS_PROTOCOL_MDNS: | |
945 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 946 | break; |
8af5b883 | 947 | |
9df3ba6c | 948 | default: |
8af5b883 | 949 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
950 | } |
951 | ||
ec2c5e43 | 952 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
953 | |
954 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
955 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
956 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
957 | return; | |
958 | } | |
959 | ||
f757cd85 LP |
960 | log_debug("Reply truncated, retrying via TCP."); |
961 | ||
ec2c5e43 LP |
962 | /* Response was truncated, let's try again with good old TCP */ |
963 | r = dns_transaction_open_tcp(t); | |
964 | if (r == -ESRCH) { | |
965 | /* No servers found? Damn! */ | |
966 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
967 | return; | |
968 | } | |
91adc4db LP |
969 | if (r == -EOPNOTSUPP) { |
970 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
971 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
972 | return; | |
973 | } | |
ec2c5e43 | 974 | if (r < 0) { |
8af5b883 | 975 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 976 | * we immediately give up */ |
7cc6ed7b LP |
977 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
978 | goto fail; | |
ec2c5e43 LP |
979 | |
980 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 981 | dns_transaction_retry(t, true); |
ec2c5e43 | 982 | } |
2a6658ef LP |
983 | |
984 | return; | |
ec2c5e43 LP |
985 | } |
986 | ||
de54e62b | 987 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
988 | r = dns_packet_extract(p); |
989 | if (r < 0) { | |
990 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
991 | return; | |
992 | } | |
993 | ||
ed9717fc | 994 | if (t->server) { |
d001e0a3 LP |
995 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
996 | * rcode and subsequently downgraded the protocol */ | |
997 | ||
998 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
999 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1000 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1001 | ||
1002 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1003 | if (!p->opt) |
1004 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1005 | ||
d001e0a3 | 1006 | /* Report that we successfully received a packet */ |
ed9717fc LP |
1007 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); |
1008 | } | |
de54e62b | 1009 | |
c02cf2f4 LP |
1010 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1011 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1012 | if (r < 0) |
1013 | goto fail; | |
c02cf2f4 LP |
1014 | if (r > 0) /* Transaction got restarted... */ |
1015 | return; | |
1016 | ||
8b419837 | 1017 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
b5efcf29 | 1018 | |
8b419837 DR |
1019 | /* When dealing with protocols other than mDNS only consider responses with |
1020 | * equivalent query section to the request. For mDNS this check doesn't make | |
1021 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1022 | * contain any questions in the Question Section". */ | |
1023 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1024 | r = dns_packet_is_reply_for(p, t->key); | |
1025 | if (r < 0) | |
1026 | goto fail; | |
1027 | if (r == 0) { | |
1028 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1029 | return; | |
1030 | } | |
547493c5 | 1031 | } |
29815b6c | 1032 | |
547493c5 DM |
1033 | /* Install the answer as answer to the transaction */ |
1034 | dns_answer_unref(t->answer); | |
1035 | t->answer = dns_answer_ref(p->answer); | |
1036 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1037 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1038 | t->answer_authenticated = false; |
79e24931 | 1039 | |
eac7cda2 LP |
1040 | r = dns_transaction_fix_rcode(t); |
1041 | if (r < 0) | |
1042 | goto fail; | |
1043 | ||
51e399bc LP |
1044 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1045 | t->block_gc++; | |
547973de | 1046 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1047 | t->block_gc--; |
1048 | ||
1049 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1050 | if (!dns_transaction_gc(t)) | |
1051 | return; | |
1052 | ||
1053 | /* Requesting additional keys might have resulted in | |
1054 | * this transaction to fail, since the auxiliary | |
1055 | * request failed for some reason. If so, we are not | |
1056 | * in pending state anymore, and we should exit | |
1057 | * quickly. */ | |
1058 | if (t->state != DNS_TRANSACTION_PENDING) | |
1059 | return; | |
7cc6ed7b LP |
1060 | if (r < 0) |
1061 | goto fail; | |
547973de LP |
1062 | if (r > 0) { |
1063 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1064 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1065 | dns_transaction_close_connection(t); |
1066 | dns_transaction_stop_timeout(t); | |
547973de LP |
1067 | return; |
1068 | } | |
547493c5 | 1069 | } |
ec2c5e43 | 1070 | |
547973de | 1071 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1072 | return; |
1073 | ||
1074 | fail: | |
1075 | t->answer_errno = -r; | |
1076 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1077 | } |
1078 | ||
c19ffd9f TG |
1079 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1080 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1081 | DnsTransaction *t = userdata; | |
1082 | int r; | |
1083 | ||
1084 | assert(t); | |
1085 | assert(t->scope); | |
1086 | ||
1087 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1088 | if (ERRNO_IS_DISCONNECT(-r)) { |
1089 | usec_t usec; | |
c19ffd9f | 1090 | |
7e1851e3 LP |
1091 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1092 | * recvmsg(). Treat this like a lost packet. */ | |
1093 | ||
92ec902a | 1094 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1095 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1096 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 | 1097 | |
d001e0a3 | 1098 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1099 | return 0; |
1100 | } | |
1101 | if (r < 0) { | |
7cc6ed7b LP |
1102 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1103 | t->answer_errno = -r; | |
7e1851e3 LP |
1104 | return 0; |
1105 | } | |
1106 | ||
1107 | r = dns_packet_validate_reply(p); | |
1108 | if (r < 0) { | |
1109 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1110 | return 0; | |
1111 | } | |
1112 | if (r == 0) { | |
e09f605e | 1113 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1114 | return 0; |
1115 | } | |
1116 | ||
1117 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1118 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1119 | return 0; |
1120 | } | |
c19ffd9f | 1121 | |
7e1851e3 | 1122 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1123 | return 0; |
1124 | } | |
1125 | ||
49cce12d | 1126 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1127 | int r; |
1128 | ||
1129 | assert(t); | |
c19ffd9f | 1130 | |
519ef046 | 1131 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1132 | |
519ef046 | 1133 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1134 | if (r < 0) |
1135 | return r; | |
c19ffd9f | 1136 | |
274b8748 | 1137 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
519ef046 LP |
1138 | return -EAGAIN; |
1139 | ||
92ec902a | 1140 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1141 | return -EOPNOTSUPP; |
1142 | ||
519ef046 LP |
1143 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1144 | int fd; | |
1145 | ||
1146 | dns_transaction_close_connection(t); | |
c19ffd9f | 1147 | |
519ef046 LP |
1148 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1149 | if (fd < 0) | |
1150 | return fd; | |
1151 | ||
1152 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1153 | if (r < 0) { | |
1154 | safe_close(fd); | |
1155 | return r; | |
1156 | } | |
1157 | ||
aa4a9deb | 1158 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1159 | t->dns_udp_fd = fd; |
1160 | } | |
1161 | ||
274b8748 | 1162 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1163 | if (r < 0) |
1164 | return r; | |
1165 | } else | |
1166 | dns_transaction_close_connection(t); | |
1167 | ||
1168 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1169 | if (r < 0) |
1170 | return r; | |
c19ffd9f | 1171 | |
519ef046 | 1172 | dns_transaction_reset_answer(t); |
be808ea0 | 1173 | |
471d40d9 | 1174 | return 0; |
c19ffd9f TG |
1175 | } |
1176 | ||
ec2c5e43 LP |
1177 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1178 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1179 | |
1180 | assert(s); | |
1181 | assert(t); | |
1182 | ||
ef7ce6df DM |
1183 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1184 | /* Timeout reached? Increase the timeout for the server used */ | |
1185 | switch (t->scope->protocol) { | |
49cce12d | 1186 | |
ef7ce6df DM |
1187 | case DNS_PROTOCOL_DNS: |
1188 | assert(t->server); | |
274b8748 | 1189 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1190 | break; |
49cce12d | 1191 | |
ef7ce6df DM |
1192 | case DNS_PROTOCOL_LLMNR: |
1193 | case DNS_PROTOCOL_MDNS: | |
1194 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1195 | break; |
49cce12d | 1196 | |
ef7ce6df DM |
1197 | default: |
1198 | assert_not_reached("Invalid DNS protocol."); | |
1199 | } | |
1200 | ||
1201 | if (t->initial_jitter_scheduled) | |
1202 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1203 | } |
1204 | ||
423659ab LP |
1205 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1206 | ||
d001e0a3 | 1207 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1208 | return 0; |
1209 | } | |
1210 | ||
9df3ba6c TG |
1211 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1212 | assert(t); | |
1213 | assert(t->scope); | |
1214 | ||
1215 | switch (t->scope->protocol) { | |
49cce12d | 1216 | |
9df3ba6c TG |
1217 | case DNS_PROTOCOL_DNS: |
1218 | assert(t->server); | |
9df3ba6c | 1219 | return t->server->resend_timeout; |
49cce12d | 1220 | |
9df3ba6c | 1221 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1222 | assert(t->n_attempts > 0); |
53fda2bb DR |
1223 | if (t->probing) |
1224 | return MDNS_PROBING_INTERVAL_USEC; | |
1225 | else | |
1226 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1227 | |
11a27c2e | 1228 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1229 | return t->scope->resend_timeout; |
49cce12d | 1230 | |
9df3ba6c TG |
1231 | default: |
1232 | assert_not_reached("Invalid DNS protocol."); | |
1233 | } | |
1234 | } | |
1235 | ||
c842ff24 | 1236 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1237 | int r; |
1238 | ||
1239 | assert(t); | |
1240 | ||
f535705a | 1241 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1242 | |
edbcc1fd LP |
1243 | r = dns_scope_network_good(t->scope); |
1244 | if (r < 0) | |
1245 | return r; | |
1246 | if (r == 0) { | |
1247 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1248 | return 0; | |
1249 | } | |
1250 | ||
ec2c5e43 LP |
1251 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1252 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1253 | return 0; | |
1254 | } | |
1255 | ||
cbe4216d | 1256 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1257 | /* If we already tried via a stream, then we don't |
1258 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1259 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1260 | return 0; | |
1261 | } | |
1262 | ||
1263 | t->n_attempts++; | |
9df3ba6c | 1264 | t->start_usec = ts; |
c61d2b44 LP |
1265 | |
1266 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1267 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1268 | |
0d2cd476 LP |
1269 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1270 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1271 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1272 | if (r < 0) |
1273 | return r; | |
1274 | if (r > 0) { | |
1275 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1276 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1277 | t->answer_authenticated = true; |
0d2cd476 LP |
1278 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1279 | return 0; | |
1280 | } | |
b2b796b8 | 1281 | |
1c02e7ba | 1282 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1283 | t->key->type == DNS_TYPE_DS) { |
1284 | ||
1285 | /* Hmm, this is a request for the root DS? A | |
1286 | * DS RR doesn't exist in the root zone, and | |
1287 | * if our trust anchor didn't know it either, | |
1288 | * this means we cannot do any DNSSEC logic | |
1289 | * anymore. */ | |
1290 | ||
1ed8c0fb | 1291 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1292 | /* We are in downgrade mode. In this |
1293 | * case, synthesize an unsigned empty | |
1294 | * response, so that the any lookup | |
1295 | * depending on this one can continue | |
1296 | * assuming there was no DS, and hence | |
1297 | * the root zone was unsigned. */ | |
1298 | ||
1299 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1300 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1301 | t->answer_authenticated = false; | |
1302 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1303 | } else | |
1304 | /* If we are not in downgrade mode, | |
1305 | * then fail the lookup, because we | |
1306 | * cannot reasonably answer it. There | |
1307 | * might be DS RRs, but we don't know | |
1308 | * them, and the DNS server won't tell | |
1309 | * them to us (and even if it would, | |
202b76ae | 1310 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1311 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1312 | ||
1313 | return 0; | |
1314 | } | |
0d2cd476 LP |
1315 | } |
1316 | ||
1317 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1318 | * for probing or verifying a zone item. */ |
547973de | 1319 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1320 | |
97ebebbc | 1321 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1322 | if (r < 0) |
1323 | return r; | |
1324 | if (r > 0) { | |
ae6a4bbf | 1325 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1326 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1327 | t->answer_authenticated = true; |
d746bb3e LP |
1328 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1329 | return 0; | |
1330 | } | |
1331 | } | |
1332 | ||
4d926a69 LP |
1333 | /* Check the cache, but only if this transaction is not used |
1334 | * for probing or verifying a zone item. */ | |
547973de | 1335 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1336 | |
4d926a69 LP |
1337 | /* Before trying the cache, let's make sure we figured out a |
1338 | * server to use. Should this cause a change of server this | |
1339 | * might flush the cache. */ | |
1340 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 1341 | |
4d926a69 LP |
1342 | /* Let's then prune all outdated entries */ |
1343 | dns_cache_prune(&t->scope->cache); | |
1344 | ||
17c8de63 | 1345 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1346 | if (r < 0) |
1347 | return r; | |
1348 | if (r > 0) { | |
c3bc53e6 | 1349 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1350 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1351 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1352 | else | |
3bbdc31d | 1353 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1354 | return 0; |
1355 | } | |
ec2c5e43 LP |
1356 | } |
1357 | ||
1effe965 DM |
1358 | return 1; |
1359 | } | |
1360 | ||
0afa57e2 DM |
1361 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1362 | ||
1363 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1364 | bool add_known_answers = false; |
0afa57e2 DM |
1365 | DnsTransaction *other; |
1366 | unsigned qdcount; | |
1367 | usec_t ts; | |
1368 | int r; | |
1369 | ||
1370 | assert(t); | |
1371 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1372 | ||
e5abebab | 1373 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1374 | t->sent = dns_packet_unref(t->sent); |
1375 | ||
1376 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1377 | if (r < 0) | |
1378 | return r; | |
1379 | ||
58ab31d5 | 1380 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1381 | if (r < 0) |
1382 | return r; | |
1383 | ||
1384 | qdcount = 1; | |
1385 | ||
7778dfff DM |
1386 | if (dns_key_is_shared(t->key)) |
1387 | add_known_answers = true; | |
1388 | ||
0afa57e2 DM |
1389 | /* |
1390 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1391 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1392 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1393 | */ | |
1394 | ||
1395 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1396 | ||
1397 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1398 | ||
1399 | /* Skip ourselves */ | |
1400 | if (other == t) | |
1401 | continue; | |
1402 | ||
1403 | if (other->state != DNS_TRANSACTION_PENDING) | |
1404 | continue; | |
1405 | ||
1406 | if (other->next_attempt_after > ts) | |
1407 | continue; | |
1408 | ||
1409 | if (qdcount >= UINT16_MAX) | |
1410 | break; | |
1411 | ||
58ab31d5 | 1412 | r = dns_packet_append_key(p, other->key, 0, NULL); |
0afa57e2 DM |
1413 | |
1414 | /* | |
1415 | * If we can't stuff more questions into the packet, just give up. | |
1416 | * One of the 'other' transactions will fire later and take care of the rest. | |
1417 | */ | |
1418 | if (r == -EMSGSIZE) | |
1419 | break; | |
1420 | ||
1421 | if (r < 0) | |
1422 | return r; | |
1423 | ||
c842ff24 | 1424 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1425 | if (r <= 0) |
1426 | continue; | |
1427 | ||
1428 | ts += transaction_get_resend_timeout(other); | |
1429 | ||
1430 | r = sd_event_add_time( | |
1431 | other->scope->manager->event, | |
1432 | &other->timeout_event_source, | |
1433 | clock_boottime_or_monotonic(), | |
1434 | ts, 0, | |
1435 | on_transaction_timeout, other); | |
1436 | if (r < 0) | |
1437 | return r; | |
1438 | ||
ff537038 | 1439 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1440 | |
0afa57e2 DM |
1441 | other->state = DNS_TRANSACTION_PENDING; |
1442 | other->next_attempt_after = ts; | |
1443 | ||
313cefa1 | 1444 | qdcount++; |
7778dfff DM |
1445 | |
1446 | if (dns_key_is_shared(other->key)) | |
1447 | add_known_answers = true; | |
0afa57e2 DM |
1448 | } |
1449 | ||
1450 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1451 | |
7778dfff DM |
1452 | /* Append known answer section if we're asking for any shared record */ |
1453 | if (add_known_answers) { | |
1454 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1455 | if (r < 0) | |
1456 | return r; | |
1457 | } | |
1458 | ||
0afa57e2 DM |
1459 | t->sent = p; |
1460 | p = NULL; | |
1461 | ||
1462 | return 0; | |
1463 | } | |
1464 | ||
1465 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1466 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1467 | int r; | |
1468 | ||
1469 | assert(t); | |
1470 | ||
1471 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1472 | return dns_transaction_make_packet_mdns(t); | |
1473 | ||
1474 | if (t->sent) | |
1475 | return 0; | |
1476 | ||
b652d4a2 | 1477 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1478 | if (r < 0) |
1479 | return r; | |
1480 | ||
58ab31d5 | 1481 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1482 | if (r < 0) |
1483 | return r; | |
1484 | ||
1485 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1486 | DNS_PACKET_HEADER(p)->id = t->id; | |
1487 | ||
1488 | t->sent = p; | |
1489 | p = NULL; | |
1490 | ||
1491 | return 0; | |
1492 | } | |
1493 | ||
1effe965 DM |
1494 | int dns_transaction_go(DnsTransaction *t) { |
1495 | usec_t ts; | |
1496 | int r; | |
202b76ae | 1497 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1498 | |
1499 | assert(t); | |
1500 | ||
5278bbfe LP |
1501 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1502 | * now. */ | |
1503 | ||
1effe965 | 1504 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1505 | |
c842ff24 | 1506 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1507 | if (r <= 0) |
1508 | return r; | |
1509 | ||
202b76ae | 1510 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1511 | t->id, |
202b76ae | 1512 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1513 | dns_protocol_to_string(t->scope->protocol), |
1514 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1515 | af_to_name_short(t->scope->family)); |
1effe965 | 1516 | |
ef7ce6df | 1517 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1518 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1519 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1520 | usec_t jitter, accuracy; | |
6e068472 LP |
1521 | |
1522 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1523 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1524 | ||
ef7ce6df | 1525 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1526 | |
1527 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1528 | |
1529 | switch (t->scope->protocol) { | |
519ef046 | 1530 | |
ea12bcc7 DM |
1531 | case DNS_PROTOCOL_LLMNR: |
1532 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1533 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1534 | break; | |
519ef046 | 1535 | |
ea12bcc7 DM |
1536 | case DNS_PROTOCOL_MDNS: |
1537 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1538 | jitter += MDNS_JITTER_MIN_USEC; | |
1539 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1540 | break; | |
1541 | default: | |
1542 | assert_not_reached("bad protocol"); | |
1543 | } | |
6e068472 LP |
1544 | |
1545 | r = sd_event_add_time( | |
1546 | t->scope->manager->event, | |
1547 | &t->timeout_event_source, | |
1548 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1549 | ts + jitter, accuracy, |
6e068472 LP |
1550 | on_transaction_timeout, t); |
1551 | if (r < 0) | |
1552 | return r; | |
1553 | ||
aa4a9deb LP |
1554 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1555 | ||
6e068472 | 1556 | t->n_attempts = 0; |
a9da14e1 | 1557 | t->next_attempt_after = ts; |
6e068472 LP |
1558 | t->state = DNS_TRANSACTION_PENDING; |
1559 | ||
ea12bcc7 | 1560 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1561 | return 0; |
1562 | } | |
1563 | ||
ec2c5e43 LP |
1564 | /* Otherwise, we need to ask the network */ |
1565 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1566 | if (r < 0) |
1567 | return r; | |
1568 | ||
1569 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1570 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1571 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1572 | |
1573 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1574 | * always be made via TCP on LLMNR */ | |
1575 | r = dns_transaction_open_tcp(t); | |
1576 | } else { | |
be808ea0 TG |
1577 | /* Try via UDP, and if that fails due to large size or lack of |
1578 | * support try via TCP */ | |
49cce12d | 1579 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1580 | if (r == -EMSGSIZE) |
1581 | log_debug("Sending query via TCP since it is too large."); | |
034e8031 LP |
1582 | if (r == -EAGAIN) |
1583 | log_debug("Sending query via TCP since server doesn't support UDP."); | |
be808ea0 | 1584 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1585 | r = dns_transaction_open_tcp(t); |
1586 | } | |
be808ea0 | 1587 | |
ec2c5e43 LP |
1588 | if (r == -ESRCH) { |
1589 | /* No servers to send this to? */ | |
1590 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1591 | return 0; | |
91adc4db LP |
1592 | } |
1593 | if (r == -EOPNOTSUPP) { | |
1594 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1595 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1596 | return 0; | |
1597 | } | |
0791110f | 1598 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1599 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1600 | * answer this request with this protocol. */ |
1601 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1602 | return 0; | |
1603 | } | |
91adc4db | 1604 | if (r < 0) { |
7cc6ed7b LP |
1605 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1606 | return r; | |
13b551ac | 1607 | |
ec2c5e43 | 1608 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1609 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1610 | |
1611 | return dns_transaction_go(t); | |
1612 | } | |
1613 | ||
a9da14e1 DM |
1614 | ts += transaction_get_resend_timeout(t); |
1615 | ||
9a015429 LP |
1616 | r = sd_event_add_time( |
1617 | t->scope->manager->event, | |
1618 | &t->timeout_event_source, | |
1619 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1620 | ts, 0, |
9a015429 | 1621 | on_transaction_timeout, t); |
ec2c5e43 LP |
1622 | if (r < 0) |
1623 | return r; | |
1624 | ||
aa4a9deb LP |
1625 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1626 | ||
ec2c5e43 | 1627 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1628 | t->next_attempt_after = ts; |
1629 | ||
ec2c5e43 LP |
1630 | return 1; |
1631 | } | |
1632 | ||
f2992dc1 LP |
1633 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1634 | DnsTransaction *n; | |
1635 | Iterator i; | |
1636 | int r; | |
1637 | ||
1638 | assert(t); | |
1639 | assert(aux); | |
1640 | ||
1641 | /* Try to find cyclic dependencies between transaction objects */ | |
1642 | ||
1643 | if (t == aux) | |
1644 | return 1; | |
1645 | ||
3eb6aa00 | 1646 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1647 | r = dns_transaction_find_cyclic(t, n); |
1648 | if (r != 0) | |
1649 | return r; | |
1650 | } | |
1651 | ||
3eb6aa00 | 1652 | return 0; |
f2992dc1 LP |
1653 | } |
1654 | ||
547973de LP |
1655 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1656 | DnsTransaction *aux; | |
1657 | int r; | |
1658 | ||
1659 | assert(t); | |
1660 | assert(ret); | |
1661 | assert(key); | |
1662 | ||
1663 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1664 | if (!aux) { | |
1665 | r = dns_transaction_new(&aux, t->scope, key); | |
1666 | if (r < 0) | |
1667 | return r; | |
1668 | } else { | |
1669 | if (set_contains(t->dnssec_transactions, aux)) { | |
1670 | *ret = aux; | |
1671 | return 0; | |
1672 | } | |
f2992dc1 LP |
1673 | |
1674 | r = dns_transaction_find_cyclic(t, aux); | |
1675 | if (r < 0) | |
1676 | return r; | |
1677 | if (r > 0) { | |
202b76ae ZJS |
1678 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1679 | ||
1680 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1681 | aux->id, |
202b76ae | 1682 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1683 | t->id, |
202b76ae ZJS |
1684 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1685 | ||
f2992dc1 LP |
1686 | return -ELOOP; |
1687 | } | |
547973de LP |
1688 | } |
1689 | ||
1690 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1691 | if (r < 0) | |
1692 | goto gc; | |
1693 | ||
1694 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1695 | if (r < 0) | |
35aa04e9 LP |
1696 | goto gc; |
1697 | ||
1698 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1699 | if (r < 0) | |
547973de LP |
1700 | goto gc; |
1701 | ||
1702 | r = set_put(t->dnssec_transactions, aux); | |
1703 | if (r < 0) | |
1704 | goto gc; | |
1705 | ||
1706 | r = set_put(aux->notify_transactions, t); | |
1707 | if (r < 0) { | |
1708 | (void) set_remove(t->dnssec_transactions, aux); | |
1709 | goto gc; | |
1710 | } | |
1711 | ||
1712 | *ret = aux; | |
1713 | return 1; | |
1714 | ||
1715 | gc: | |
1716 | dns_transaction_gc(aux); | |
1717 | return r; | |
1718 | } | |
1719 | ||
1720 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1721 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1722 | DnsTransaction *aux; | |
1723 | int r; | |
1724 | ||
1725 | assert(t); | |
1726 | assert(key); | |
1727 | ||
1728 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1729 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1730 | if (r < 0) |
1731 | return r; | |
1732 | if (r > 0) { | |
1733 | r = dns_answer_extend(&t->validated_keys, a); | |
1734 | if (r < 0) | |
1735 | return r; | |
1736 | ||
1737 | return 0; | |
1738 | } | |
1739 | ||
1740 | /* This didn't work, ask for it via the network/cache then. */ | |
1741 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1742 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1743 | return 0; | |
547973de LP |
1744 | if (r < 0) |
1745 | return r; | |
1746 | ||
1747 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1748 | r = dns_transaction_go(aux); | |
1749 | if (r < 0) | |
1750 | return r; | |
1751 | } | |
1752 | ||
f2992dc1 | 1753 | return 1; |
547973de LP |
1754 | } |
1755 | ||
8a516214 LP |
1756 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1757 | int r; | |
1758 | ||
1759 | assert(t); | |
1760 | ||
c629ff58 | 1761 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1762 | * database, either in the global one, or the link-local |
1763 | * one. */ | |
1764 | ||
1765 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1766 | if (r != 0) | |
1767 | return r; | |
1768 | ||
1769 | if (!t->scope->link) | |
1770 | return 0; | |
1771 | ||
1772 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1773 | } | |
1774 | ||
105e1512 LP |
1775 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1776 | int r; | |
1777 | ||
1778 | assert(t); | |
1779 | ||
1780 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1781 | * RRs to prove it */ | |
1782 | ||
1783 | r = dns_transaction_has_positive_answer(t, NULL); | |
1784 | if (r < 0) | |
1785 | return r; | |
1786 | if (r > 0) | |
1787 | return false; | |
1788 | ||
8e54f5d9 LP |
1789 | /* Is this key explicitly listed as a negative trust anchor? |
1790 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1791 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1792 | if (r < 0) |
1793 | return r; | |
1794 | if (r > 0) | |
1795 | return false; | |
1796 | ||
105e1512 LP |
1797 | /* The answer does not contain any RRs that match to the |
1798 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1799 | * included. If not, the answer is unsigned. */ | |
1800 | ||
1801 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1802 | if (r < 0) | |
1803 | return r; | |
1804 | if (r > 0) | |
1805 | return false; | |
1806 | ||
1807 | return true; | |
1808 | } | |
1809 | ||
1810 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1811 | int r; | |
1812 | ||
1813 | assert(t); | |
1814 | assert(rr); | |
1815 | ||
1816 | /* Check if the specified RR is the "primary" response, | |
1817 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1818 | * CNAME/DNAME for it. */ |
105e1512 LP |
1819 | |
1820 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1821 | if (r != 0) | |
1822 | return r; | |
1823 | ||
4cb94977 | 1824 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1825 | } |
1826 | ||
92ec902a LP |
1827 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1828 | assert(t); | |
1829 | ||
1830 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1831 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1832 | ||
1833 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1834 | return false; | |
1835 | ||
1836 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1837 | * be supported, hence return true. */ | |
1838 | if (!t->server) | |
1839 | return true; | |
1840 | ||
d001e0a3 LP |
1841 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1842 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1843 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1844 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1845 | |
1846 | return dns_server_dnssec_supported(t->server); | |
1847 | } | |
1848 | ||
1849 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1850 | DnsTransaction *dt; | |
1851 | Iterator i; | |
1852 | ||
1853 | assert(t); | |
1854 | ||
1855 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1856 | ||
1857 | if (!dns_transaction_dnssec_supported(t)) | |
1858 | return false; | |
1859 | ||
1860 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1861 | if (!dns_transaction_dnssec_supported(dt)) | |
1862 | return false; | |
1863 | ||
1864 | return true; | |
1865 | } | |
1866 | ||
547973de LP |
1867 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1868 | DnsResourceRecord *rr; | |
105e1512 | 1869 | |
547973de LP |
1870 | int r; |
1871 | ||
1872 | assert(t); | |
1873 | ||
105e1512 LP |
1874 | /* |
1875 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1876 | * we can verify signatures or prove that RRs are rightfully | |
1877 | * unsigned. Specifically: | |
1878 | * | |
1879 | * - For RRSIG we get the matching DNSKEY | |
1880 | * - For DNSKEY we get the matching DS | |
1881 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1882 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 1883 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
1884 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
1885 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
1886 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
1887 | */ | |
1888 | ||
b652d4a2 | 1889 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1890 | return 0; |
92ec902a LP |
1891 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1892 | return 0; /* We only need to validate stuff from the network */ | |
1893 | if (!dns_transaction_dnssec_supported(t)) | |
1894 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1895 | |
547973de LP |
1896 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1897 | ||
105e1512 LP |
1898 | if (dns_type_is_pseudo(rr->key->type)) |
1899 | continue; | |
1900 | ||
8e54f5d9 | 1901 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 1902 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
1903 | if (r < 0) |
1904 | return r; | |
1905 | if (r > 0) | |
1906 | continue; | |
1907 | ||
547973de LP |
1908 | switch (rr->key->type) { |
1909 | ||
1910 | case DNS_TYPE_RRSIG: { | |
1911 | /* For each RRSIG we request the matching DNSKEY */ | |
1912 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1913 | ||
1914 | /* If this RRSIG is about a DNSKEY RR and the | |
1915 | * signer is the same as the owner, then we | |
1916 | * already have the DNSKEY, and we don't have | |
1917 | * to look for more. */ | |
1918 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 1919 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
1920 | if (r < 0) |
1921 | return r; | |
1922 | if (r > 0) | |
1923 | continue; | |
1924 | } | |
1925 | ||
105e1512 LP |
1926 | /* If the signer is not a parent of our |
1927 | * original query, then this is about an | |
1928 | * auxiliary RRset, but not anything we asked | |
1929 | * for. In this case we aren't interested, | |
1930 | * because we don't want to request additional | |
1931 | * RRs for stuff we didn't really ask for, and | |
1932 | * also to avoid request loops, where | |
1933 | * additional RRs from one transaction result | |
1934 | * in another transaction whose additonal RRs | |
1935 | * point back to the original transaction, and | |
1936 | * we deadlock. */ | |
1c02e7ba | 1937 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
1938 | if (r < 0) |
1939 | return r; | |
1940 | if (r == 0) | |
1941 | continue; | |
1942 | ||
1943 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1944 | if (!dnskey) | |
1945 | return -ENOMEM; | |
1946 | ||
1c02e7ba ZJS |
1947 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
1948 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
1949 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1950 | if (r < 0) | |
1951 | return r; | |
1952 | break; | |
1953 | } | |
1954 | ||
1955 | case DNS_TYPE_DNSKEY: { | |
1956 | /* For each DNSKEY we request the matching DS */ | |
1957 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1958 | ||
105e1512 LP |
1959 | /* If the DNSKEY we are looking at is not for |
1960 | * zone we are interested in, nor any of its | |
1961 | * parents, we aren't interested, and don't | |
1962 | * request it. After all, we don't want to end | |
1963 | * up in request loops, and want to keep | |
1964 | * additional traffic down. */ | |
1965 | ||
1c02e7ba | 1966 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
1967 | if (r < 0) |
1968 | return r; | |
1969 | if (r == 0) | |
1970 | continue; | |
1971 | ||
1c02e7ba | 1972 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
1973 | if (!ds) |
1974 | return -ENOMEM; | |
1975 | ||
1c02e7ba ZJS |
1976 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
1977 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
1978 | r = dns_transaction_request_dnssec_rr(t, ds); |
1979 | if (r < 0) | |
1980 | return r; | |
547973de | 1981 | |
105e1512 LP |
1982 | break; |
1983 | } | |
1984 | ||
105e1512 LP |
1985 | case DNS_TYPE_SOA: |
1986 | case DNS_TYPE_NS: { | |
1987 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1988 | ||
1989 | /* For an unsigned SOA or NS, try to acquire | |
1990 | * the matching DS RR, as we are at a zone cut | |
1991 | * then, and whether a DS exists tells us | |
1992 | * whether the zone is signed. Do so only if | |
1993 | * this RR matches our original question, | |
1994 | * however. */ | |
1995 | ||
1996 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1997 | if (r < 0) | |
1998 | return r; | |
1999 | if (r == 0) | |
2000 | continue; | |
2001 | ||
2002 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2003 | if (r < 0) | |
2004 | return r; | |
2005 | if (r > 0) | |
2006 | continue; | |
2007 | ||
1c02e7ba | 2008 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2009 | if (!ds) |
2010 | return -ENOMEM; | |
2011 | ||
1c02e7ba ZJS |
2012 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2013 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2014 | r = dns_transaction_request_dnssec_rr(t, ds); |
2015 | if (r < 0) | |
2016 | return r; | |
2017 | ||
2018 | break; | |
105e1512 LP |
2019 | } |
2020 | ||
b63fca62 | 2021 | case DNS_TYPE_DS: |
105e1512 LP |
2022 | case DNS_TYPE_CNAME: |
2023 | case DNS_TYPE_DNAME: { | |
2024 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2025 | const char *name; | |
2026 | ||
2027 | /* CNAMEs and DNAMEs cannot be located at a | |
2028 | * zone apex, hence ask for the parent SOA for | |
2029 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2030 | * apex. But do all that only if this is | |
2031 | * actually a response to our original | |
b63fca62 LP |
2032 | * question. |
2033 | * | |
2034 | * Similar for DS RRs, which are signed when | |
2035 | * the parent SOA is signed. */ | |
105e1512 LP |
2036 | |
2037 | r = dns_transaction_is_primary_response(t, rr); | |
2038 | if (r < 0) | |
2039 | return r; | |
2040 | if (r == 0) | |
2041 | continue; | |
2042 | ||
2043 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2044 | if (r < 0) | |
2045 | return r; | |
2046 | if (r > 0) | |
2047 | continue; | |
2048 | ||
43e6779a LP |
2049 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2050 | if (r < 0) | |
2051 | return r; | |
2052 | if (r > 0) | |
2053 | continue; | |
2054 | ||
1c02e7ba | 2055 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2056 | r = dns_name_parent(&name); |
2057 | if (r < 0) | |
2058 | return r; | |
2059 | if (r == 0) | |
2060 | continue; | |
2061 | ||
2062 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2063 | if (!soa) | |
2064 | return -ENOMEM; | |
2065 | ||
1c02e7ba ZJS |
2066 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2067 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2068 | r = dns_transaction_request_dnssec_rr(t, soa); |
2069 | if (r < 0) | |
2070 | return r; | |
2071 | ||
2072 | break; | |
2073 | } | |
2074 | ||
2075 | default: { | |
2076 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2077 | ||
b63fca62 LP |
2078 | /* For other unsigned RRsets (including |
2079 | * NSEC/NSEC3!), look for proof the zone is | |
2080 | * unsigned, by requesting the SOA RR of the | |
2081 | * zone. However, do so only if they are | |
2082 | * directly relevant to our original | |
105e1512 LP |
2083 | * question. */ |
2084 | ||
2085 | r = dns_transaction_is_primary_response(t, rr); | |
2086 | if (r < 0) | |
2087 | return r; | |
2088 | if (r == 0) | |
2089 | continue; | |
2090 | ||
2091 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2092 | if (r < 0) | |
2093 | return r; | |
2094 | if (r > 0) | |
2095 | continue; | |
2096 | ||
1c02e7ba | 2097 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2098 | if (!soa) |
2099 | return -ENOMEM; | |
2100 | ||
1c02e7ba ZJS |
2101 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2102 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2103 | r = dns_transaction_request_dnssec_rr(t, soa); |
2104 | if (r < 0) | |
2105 | return r; | |
2106 | break; | |
547973de LP |
2107 | }} |
2108 | } | |
2109 | ||
105e1512 LP |
2110 | /* Above, we requested everything necessary to validate what |
2111 | * we got. Now, let's request what we need to validate what we | |
2112 | * didn't get... */ | |
2113 | ||
2114 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2115 | if (r < 0) | |
2116 | return r; | |
2117 | if (r > 0) { | |
2118 | const char *name; | |
4bbc06cc | 2119 | uint16_t type = 0; |
105e1512 | 2120 | |
1c02e7ba | 2121 | name = dns_resource_key_name(t->key); |
105e1512 | 2122 | |
4bbc06cc LP |
2123 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2124 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2125 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2126 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2127 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2128 | * to see if that is signed. */ | |
105e1512 | 2129 | |
4bbc06cc | 2130 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2131 | r = dns_name_parent(&name); |
4bbc06cc LP |
2132 | if (r > 0) { |
2133 | type = DNS_TYPE_SOA; | |
2134 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2135 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2136 | } else |
105e1512 | 2137 | name = NULL; |
4bbc06cc LP |
2138 | |
2139 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2140 | ||
2141 | type = DNS_TYPE_DS; | |
2142 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2143 | t->id, dns_resource_key_name(t->key)); | |
2144 | ||
2145 | } else { | |
2146 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2147 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2148 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2149 | } |
105e1512 LP |
2150 | |
2151 | if (name) { | |
2152 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2153 | ||
4bbc06cc | 2154 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2155 | if (!soa) |
2156 | return -ENOMEM; | |
2157 | ||
2158 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2159 | if (r < 0) | |
2160 | return r; | |
2161 | } | |
2162 | } | |
2163 | ||
2164 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2165 | } |
2166 | ||
2167 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2168 | assert(t); |
547973de LP |
2169 | assert(source); |
2170 | ||
942eb2e7 LP |
2171 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2172 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2173 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2174 | |
942eb2e7 LP |
2175 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2176 | dns_transaction_process_dnssec(t); | |
547973de LP |
2177 | } |
2178 | ||
105e1512 LP |
2179 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2180 | DnsResourceRecord *rr; | |
2181 | int ifindex, r; | |
2182 | ||
2183 | assert(t); | |
2184 | ||
2185 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2186 | * RRs from the list of validated keys to the list of | |
2187 | * validated keys. */ | |
2188 | ||
2189 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2190 | ||
96bb7673 | 2191 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2192 | if (r < 0) |
2193 | return r; | |
2194 | if (r == 0) | |
2195 | continue; | |
2196 | ||
2197 | /* If so, the DNSKEY is validated too. */ | |
2198 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2199 | if (r < 0) | |
2200 | return r; | |
2201 | } | |
2202 | ||
2203 | return 0; | |
2204 | } | |
2205 | ||
2206 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2207 | int r; |
2208 | ||
2209 | assert(t); | |
2210 | assert(rr); | |
2211 | ||
105e1512 LP |
2212 | /* Checks if the RR we are looking for must be signed with an |
2213 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2214 | |
b652d4a2 | 2215 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2216 | return false; |
56352fe9 | 2217 | |
105e1512 LP |
2218 | if (dns_type_is_pseudo(rr->key->type)) |
2219 | return -EINVAL; | |
56352fe9 | 2220 | |
1c02e7ba | 2221 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2222 | if (r < 0) |
2223 | return r; | |
2224 | if (r > 0) | |
2225 | return false; | |
2226 | ||
105e1512 | 2227 | switch (rr->key->type) { |
56352fe9 | 2228 | |
105e1512 LP |
2229 | case DNS_TYPE_RRSIG: |
2230 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2231 | return false; | |
2232 | ||
2233 | case DNS_TYPE_SOA: | |
2234 | case DNS_TYPE_NS: { | |
2235 | DnsTransaction *dt; | |
2236 | Iterator i; | |
2237 | ||
b63fca62 | 2238 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2239 | |
2240 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2241 | ||
2242 | if (dt->key->class != rr->key->class) | |
2243 | continue; | |
2244 | if (dt->key->type != DNS_TYPE_DS) | |
2245 | continue; | |
2246 | ||
1c02e7ba | 2247 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2248 | if (r < 0) |
2249 | return r; | |
2250 | if (r == 0) | |
2251 | continue; | |
2252 | ||
2253 | /* We found a DS transactions for the SOA/NS | |
2254 | * RRs we are looking at. If it discovered signed DS | |
2255 | * RRs, then we need to be signed, too. */ | |
2256 | ||
097a2517 TA |
2257 | if (!dt->answer_authenticated) |
2258 | return false; | |
105e1512 | 2259 | |
097a2517 | 2260 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2261 | } |
2262 | ||
2263 | /* We found nothing that proves this is safe to leave | |
2264 | * this unauthenticated, hence ask inist on | |
2265 | * authentication. */ | |
2266 | return true; | |
2267 | } | |
2268 | ||
b63fca62 | 2269 | case DNS_TYPE_DS: |
105e1512 LP |
2270 | case DNS_TYPE_CNAME: |
2271 | case DNS_TYPE_DNAME: { | |
2272 | const char *parent = NULL; | |
2273 | DnsTransaction *dt; | |
2274 | Iterator i; | |
2275 | ||
b63fca62 LP |
2276 | /* |
2277 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2278 | * | |
2279 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2280 | */ | |
105e1512 LP |
2281 | |
2282 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2283 | ||
2284 | if (dt->key->class != rr->key->class) | |
2285 | continue; | |
2286 | if (dt->key->type != DNS_TYPE_SOA) | |
2287 | continue; | |
2288 | ||
2289 | if (!parent) { | |
1c02e7ba | 2290 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2291 | r = dns_name_parent(&parent); |
2292 | if (r < 0) | |
2293 | return r; | |
2294 | if (r == 0) { | |
b63fca62 LP |
2295 | if (rr->key->type == DNS_TYPE_DS) |
2296 | return true; | |
2297 | ||
105e1512 LP |
2298 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2299 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2300 | return -EBADMSG; | |
2301 | } | |
2302 | } | |
2303 | ||
1c02e7ba | 2304 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2305 | if (r < 0) |
2306 | return r; | |
2307 | if (r == 0) | |
2308 | continue; | |
2309 | ||
2310 | return t->answer_authenticated; | |
2311 | } | |
2312 | ||
2313 | return true; | |
2314 | } | |
2315 | ||
2316 | default: { | |
2317 | DnsTransaction *dt; | |
2318 | Iterator i; | |
2319 | ||
b63fca62 | 2320 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2321 | |
2322 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2323 | ||
2324 | if (dt->key->class != rr->key->class) | |
2325 | continue; | |
2326 | if (dt->key->type != DNS_TYPE_SOA) | |
2327 | continue; | |
2328 | ||
1c02e7ba | 2329 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2330 | if (r < 0) |
2331 | return r; | |
2332 | if (r == 0) | |
2333 | continue; | |
2334 | ||
2335 | /* We found the transaction that was supposed to find | |
2336 | * the SOA RR for us. It was successful, but found no | |
2337 | * RR for us. This means we are not at a zone cut. In | |
2338 | * this case, we require authentication if the SOA | |
2339 | * lookup was authenticated too. */ | |
2340 | return t->answer_authenticated; | |
2341 | } | |
2342 | ||
2343 | return true; | |
2344 | }} | |
56352fe9 LP |
2345 | } |
2346 | ||
d33b6cf3 LP |
2347 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2348 | DnsTransaction *dt; | |
2349 | const char *tld; | |
2350 | Iterator i; | |
2351 | int r; | |
2352 | ||
2353 | /* If DNSSEC downgrade mode is on, checks whether the | |
2354 | * specified RR is one level below a TLD we have proven not to | |
2355 | * exist. In such a case we assume that this is a private | |
2356 | * domain, and permit it. | |
2357 | * | |
2358 | * This detects cases like the Fritz!Box router networks. Each | |
2359 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2360 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2361 | * are served by the router itself, while requests for the | |
2362 | * "box" domain will result in NXDOMAIN. | |
2363 | * | |
2364 | * Note that this logic is unable to detect cases where a | |
2365 | * router serves a private DNS zone directly under | |
2366 | * non-existing TLD. In such a case we cannot detect whether | |
2367 | * the TLD is supposed to exist or not, as all requests we | |
2368 | * make for it will be answered by the router's zone, and not | |
2369 | * by the root zone. */ | |
2370 | ||
2371 | assert(t); | |
2372 | ||
2373 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2374 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2375 | ||
1c02e7ba | 2376 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2377 | r = dns_name_parent(&tld); |
2378 | if (r < 0) | |
2379 | return r; | |
2380 | if (r == 0) | |
2381 | return false; /* Already the root domain */ | |
2382 | ||
2383 | if (!dns_name_is_single_label(tld)) | |
2384 | return false; | |
2385 | ||
2386 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2387 | ||
2388 | if (dt->key->class != key->class) | |
2389 | continue; | |
2390 | ||
1c02e7ba | 2391 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2392 | if (r < 0) |
2393 | return r; | |
2394 | if (r == 0) | |
2395 | continue; | |
2396 | ||
2397 | /* We found an auxiliary lookup we did for the TLD. If | |
2398 | * that returned with NXDOMAIN, we know the TLD didn't | |
2399 | * exist, and hence this might be a private zone. */ | |
2400 | ||
2401 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2402 | } | |
2403 | ||
2404 | return false; | |
2405 | } | |
2406 | ||
105e1512 | 2407 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2408 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2409 | DnsTransaction *dt; |
2410 | const char *name; | |
4bbc06cc | 2411 | uint16_t type = 0; |
105e1512 LP |
2412 | Iterator i; |
2413 | int r; | |
56352fe9 LP |
2414 | |
2415 | assert(t); | |
2416 | ||
105e1512 LP |
2417 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2418 | * this negative reply */ | |
56352fe9 | 2419 | |
b652d4a2 | 2420 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2421 | return false; |
56352fe9 | 2422 | |
105e1512 LP |
2423 | if (dns_type_is_pseudo(t->key->type)) |
2424 | return -EINVAL; | |
2425 | ||
1c02e7ba | 2426 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2427 | if (r < 0) |
2428 | return r; | |
2429 | if (r > 0) | |
2430 | return false; | |
2431 | ||
d33b6cf3 LP |
2432 | r = dns_transaction_in_private_tld(t, t->key); |
2433 | if (r < 0) | |
2434 | return r; | |
2435 | if (r > 0) { | |
2436 | /* The lookup is from a TLD that is proven not to | |
2437 | * exist, and we are in downgrade mode, hence ignore | |
2438 | * that fact that we didn't get any NSEC RRs.*/ | |
2439 | ||
202b76ae ZJS |
2440 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2441 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2442 | return false; |
2443 | } | |
2444 | ||
1c02e7ba | 2445 | name = dns_resource_key_name(t->key); |
105e1512 | 2446 | |
4bbc06cc | 2447 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2448 | |
4bbc06cc LP |
2449 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2450 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2451 | |
2452 | r = dns_name_parent(&name); | |
56352fe9 LP |
2453 | if (r < 0) |
2454 | return r; | |
2455 | if (r == 0) | |
105e1512 | 2456 | return true; |
4bbc06cc LP |
2457 | |
2458 | type = DNS_TYPE_SOA; | |
2459 | ||
2460 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2461 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2462 | type = DNS_TYPE_DS; | |
2463 | else | |
2464 | /* For all other negative replies, check for the SOA lookup */ | |
2465 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2466 | |
2467 | /* For all other RRs we check the SOA on the same level to see | |
2468 | * if it's signed. */ | |
2469 | ||
2470 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2471 | ||
2472 | if (dt->key->class != t->key->class) | |
2473 | continue; | |
4bbc06cc | 2474 | if (dt->key->type != type) |
56352fe9 LP |
2475 | continue; |
2476 | ||
1c02e7ba | 2477 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2478 | if (r < 0) |
2479 | return r; | |
105e1512 LP |
2480 | if (r == 0) |
2481 | continue; | |
2482 | ||
2483 | return dt->answer_authenticated; | |
56352fe9 LP |
2484 | } |
2485 | ||
105e1512 LP |
2486 | /* If in doubt, require NSEC/NSEC3 */ |
2487 | return true; | |
56352fe9 LP |
2488 | } |
2489 | ||
94aa7071 LP |
2490 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2491 | DnsResourceRecord *rrsig; | |
2492 | bool found = false; | |
2493 | int r; | |
2494 | ||
2495 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2496 | * the specified RRset is authenticated (i.e. has a matching | |
2497 | * DS RR). */ | |
2498 | ||
1c02e7ba | 2499 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2500 | if (r < 0) |
2501 | return r; | |
2502 | if (r > 0) | |
2503 | return false; | |
2504 | ||
94aa7071 LP |
2505 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2506 | DnsTransaction *dt; | |
2507 | Iterator i; | |
2508 | ||
2509 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2510 | if (r < 0) | |
2511 | return r; | |
2512 | if (r == 0) | |
2513 | continue; | |
2514 | ||
2515 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2516 | ||
2517 | if (dt->key->class != rr->key->class) | |
2518 | continue; | |
2519 | ||
2520 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2521 | ||
1c02e7ba | 2522 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2523 | if (r < 0) |
2524 | return r; | |
2525 | if (r == 0) | |
2526 | continue; | |
2527 | ||
2528 | /* OK, we found an auxiliary DNSKEY | |
2529 | * lookup. If that lookup is | |
2530 | * authenticated, report this. */ | |
2531 | ||
2532 | if (dt->answer_authenticated) | |
2533 | return true; | |
2534 | ||
2535 | found = true; | |
2536 | ||
2537 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2538 | ||
1c02e7ba | 2539 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2540 | if (r < 0) |
2541 | return r; | |
2542 | if (r == 0) | |
2543 | continue; | |
2544 | ||
2545 | /* OK, we found an auxiliary DS | |
2546 | * lookup. If that lookup is | |
2547 | * authenticated and non-zero, we | |
2548 | * won! */ | |
2549 | ||
2550 | if (!dt->answer_authenticated) | |
2551 | return false; | |
2552 | ||
2553 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2554 | } | |
2555 | } | |
2556 | } | |
2557 | ||
2558 | return found ? false : -ENXIO; | |
2559 | } | |
2560 | ||
b652d4a2 LP |
2561 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2562 | assert(t); | |
2563 | assert(rr); | |
2564 | ||
2565 | /* We know that the root domain is signed, hence if it appears | |
2566 | * not to be signed, there's a problem with the DNS server */ | |
2567 | ||
2568 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2569 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2570 | } |
2571 | ||
0f87f3e8 LP |
2572 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2573 | DnsResourceRecord *rr; | |
2574 | int r; | |
2575 | ||
2576 | assert(t); | |
2577 | ||
2578 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2579 | * for a key from our trust anchor. Note that we don't care | |
2580 | * whether the DNSKEY can be authenticated or not. It's | |
2581 | * sufficient if it is self-signed. */ | |
2582 | ||
2583 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2584 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2585 | if (r < 0) |
2586 | return r; | |
2587 | } | |
2588 | ||
2589 | return 0; | |
2590 | } | |
2591 | ||
c9c72065 LP |
2592 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2593 | bool changed; | |
2594 | int r; | |
2595 | ||
2596 | assert(t); | |
2597 | ||
2598 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2599 | * our trust anchors database considers revoked. */ | |
2600 | ||
2601 | do { | |
2602 | DnsResourceRecord *rr; | |
2603 | ||
2604 | changed = false; | |
2605 | ||
2606 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2607 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2608 | if (r < 0) | |
2609 | return r; | |
2610 | if (r > 0) { | |
2611 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2612 | if (r < 0) | |
2613 | return r; | |
2614 | ||
2615 | assert(r > 0); | |
2616 | changed = true; | |
2617 | break; | |
2618 | } | |
2619 | } | |
2620 | } while (changed); | |
2621 | ||
2622 | return 0; | |
2623 | } | |
2624 | ||
942eb2e7 LP |
2625 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2626 | DnsTransaction *dt; | |
2627 | Iterator i; | |
2628 | int r; | |
2629 | ||
2630 | assert(t); | |
2631 | ||
2632 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2633 | ||
2634 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2635 | ||
2636 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2637 | continue; | |
2638 | ||
2639 | if (!dt->answer_authenticated) | |
2640 | continue; | |
2641 | ||
2642 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2643 | if (r < 0) | |
2644 | return r; | |
2645 | } | |
2646 | ||
2647 | return 0; | |
2648 | } | |
2649 | ||
c690b20a ZJS |
2650 | typedef enum { |
2651 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2652 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2653 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2654 | } Phase; | |
2655 | ||
2656 | static int dnssec_validate_records( | |
2657 | DnsTransaction *t, | |
2658 | Phase phase, | |
2659 | bool *have_nsec, | |
2660 | DnsAnswer **validated) { | |
2661 | ||
547973de | 2662 | DnsResourceRecord *rr; |
56352fe9 | 2663 | int r; |
547973de | 2664 | |
c690b20a | 2665 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2666 | |
c690b20a ZJS |
2667 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2668 | DnsResourceRecord *rrsig = NULL; | |
2669 | DnssecResult result; | |
547973de | 2670 | |
c690b20a ZJS |
2671 | switch (rr->key->type) { |
2672 | case DNS_TYPE_RRSIG: | |
2673 | continue; | |
547973de | 2674 | |
c690b20a ZJS |
2675 | case DNS_TYPE_DNSKEY: |
2676 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2677 | if (phase == DNSSEC_PHASE_NSEC) | |
2678 | continue; | |
2679 | break; | |
547973de | 2680 | |
c690b20a ZJS |
2681 | case DNS_TYPE_NSEC: |
2682 | case DNS_TYPE_NSEC3: | |
2683 | *have_nsec = true; | |
547973de | 2684 | |
c690b20a ZJS |
2685 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2686 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2687 | continue; | |
2688 | break; | |
105e1512 | 2689 | |
c690b20a ZJS |
2690 | default: |
2691 | /* We validate all other RRs only in the ALL phases */ | |
2692 | if (phase != DNSSEC_PHASE_ALL) | |
2693 | continue; | |
2694 | } | |
b652d4a2 | 2695 | |
c690b20a ZJS |
2696 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2697 | if (r < 0) | |
2698 | return r; | |
547973de | 2699 | |
c690b20a | 2700 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2701 | |
c690b20a | 2702 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2703 | |
c690b20a ZJS |
2704 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2705 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2706 | * the set of validated keys for this transaction. */ | |
547973de | 2707 | |
c690b20a ZJS |
2708 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2709 | if (r < 0) | |
2710 | return r; | |
c9c72065 | 2711 | |
c690b20a ZJS |
2712 | /* Some of the DNSKEYs we just added might already have been revoked, |
2713 | * remove them again in that case. */ | |
2714 | r = dns_transaction_invalidate_revoked_keys(t); | |
2715 | if (r < 0) | |
2716 | return r; | |
2717 | } | |
547973de | 2718 | |
c690b20a ZJS |
2719 | /* Add the validated RRset to the new list of validated |
2720 | * RRsets, and remove it from the unvalidated RRsets. | |
2721 | * We mark the RRset as authenticated and cacheable. */ | |
2722 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2723 | if (r < 0) | |
2724 | return r; | |
547973de | 2725 | |
c690b20a | 2726 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2727 | |
c690b20a ZJS |
2728 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2729 | return 1; | |
2730 | } | |
547973de | 2731 | |
c690b20a ZJS |
2732 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2733 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2734 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2735 | if (phase != DNSSEC_PHASE_ALL) | |
2736 | continue; | |
0c7bff0a | 2737 | |
c690b20a ZJS |
2738 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2739 | bool authenticated = false; | |
2740 | const char *source; | |
0c7bff0a | 2741 | |
c690b20a ZJS |
2742 | /* This RRset validated, but as a wildcard. This means we need |
2743 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists.*/ | |
0c7bff0a | 2744 | |
c690b20a ZJS |
2745 | /* First step, determine the source of synthesis */ |
2746 | r = dns_resource_record_source(rrsig, &source); | |
2747 | if (r < 0) | |
2748 | return r; | |
0c7bff0a | 2749 | |
c690b20a | 2750 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2751 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2752 | source, |
2753 | rrsig->rrsig.signer, | |
2754 | &authenticated); | |
0c7bff0a | 2755 | |
c690b20a ZJS |
2756 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2757 | if (r == 0) | |
2758 | result = DNSSEC_INVALID; | |
2759 | else { | |
2760 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2761 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2762 | if (r < 0) | |
2763 | return r; | |
2764 | ||
2765 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2766 | ||
2767 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2768 | return 1; | |
0c7bff0a | 2769 | } |
c690b20a | 2770 | } |
0c7bff0a | 2771 | |
c690b20a ZJS |
2772 | if (result == DNSSEC_NO_SIGNATURE) { |
2773 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2774 | if (r < 0) |
2775 | return r; | |
c690b20a ZJS |
2776 | if (r == 0) { |
2777 | /* Data does not require signing. In that case, just copy it over, | |
2778 | * but remember that this is by no means authenticated.*/ | |
2779 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); | |
2780 | if (r < 0) | |
2781 | return r; | |
2782 | ||
2783 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2784 | return 1; | |
2785 | } | |
547973de | 2786 | |
c690b20a ZJS |
2787 | r = dns_transaction_known_signed(t, rr); |
2788 | if (r < 0) | |
2789 | return r; | |
2790 | if (r > 0) { | |
2791 | /* This is an RR we know has to be signed. If it isn't this means | |
2792 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2793 | |
c690b20a | 2794 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2795 | |
c690b20a | 2796 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2797 | |
c690b20a | 2798 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2799 | |
c690b20a | 2800 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2801 | if (r < 0) |
2802 | return r; | |
547973de | 2803 | |
c690b20a ZJS |
2804 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2805 | return 1; | |
2806 | } | |
a150ff5e | 2807 | |
c690b20a ZJS |
2808 | /* Otherwise, fail */ |
2809 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2810 | return 0; | |
f3cf586d | 2811 | } |
547973de | 2812 | |
c690b20a ZJS |
2813 | r = dns_transaction_in_private_tld(t, rr->key); |
2814 | if (r < 0) | |
2815 | return r; | |
2816 | if (r > 0) { | |
202b76ae | 2817 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2818 | |
c690b20a ZJS |
2819 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2820 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2821 | |
202b76ae ZJS |
2822 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2823 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2824 | |
c690b20a | 2825 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2826 | if (r < 0) |
2827 | return r; | |
0c7bff0a | 2828 | |
c690b20a ZJS |
2829 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2830 | return 1; | |
2831 | } | |
2832 | } | |
0c7bff0a | 2833 | |
c690b20a ZJS |
2834 | if (IN_SET(result, |
2835 | DNSSEC_MISSING_KEY, | |
2836 | DNSSEC_SIGNATURE_EXPIRED, | |
2837 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2838 | |
c690b20a ZJS |
2839 | r = dns_transaction_dnskey_authenticated(t, rr); |
2840 | if (r < 0 && r != -ENXIO) | |
2841 | return r; | |
2842 | if (r == 0) { | |
2843 | /* The DNSKEY transaction was not authenticated, this means there's | |
2844 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2845 | |
c690b20a | 2846 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2847 | if (r < 0) |
2848 | return r; | |
b652d4a2 | 2849 | |
c690b20a ZJS |
2850 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2851 | return 1; | |
2852 | } | |
2853 | } | |
b652d4a2 | 2854 | |
c690b20a ZJS |
2855 | r = dns_transaction_is_primary_response(t, rr); |
2856 | if (r < 0) | |
2857 | return r; | |
2858 | if (r > 0) { | |
2859 | /* Look for a matching DNAME for this CNAME */ | |
2860 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2861 | if (r < 0) | |
2862 | return r; | |
2863 | if (r == 0) { | |
2864 | /* Also look among the stuff we already validated */ | |
2865 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2866 | if (r < 0) |
2867 | return r; | |
c690b20a | 2868 | } |
d33b6cf3 | 2869 | |
c690b20a ZJS |
2870 | if (r == 0) { |
2871 | if (IN_SET(result, | |
2872 | DNSSEC_INVALID, | |
2873 | DNSSEC_SIGNATURE_EXPIRED, | |
2874 | DNSSEC_NO_SIGNATURE)) | |
2875 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
2876 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2877 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
2878 | ||
2879 | /* This is a primary response to our question, and it failed validation. | |
2880 | * That's fatal. */ | |
2881 | t->answer_dnssec_result = result; | |
2882 | return 0; | |
2883 | } | |
d33b6cf3 | 2884 | |
c690b20a ZJS |
2885 | /* This is a primary response, but we do have a DNAME RR |
2886 | * in the RR that can replay this CNAME, hence rely on | |
2887 | * that, and we can remove the CNAME in favour of it. */ | |
2888 | } | |
d33b6cf3 | 2889 | |
c690b20a ZJS |
2890 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
2891 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2892 | if (r < 0) | |
2893 | return r; | |
d33b6cf3 | 2894 | |
c690b20a ZJS |
2895 | /* We dropped something from the answer, start from the beginning. */ |
2896 | return 1; | |
2897 | } | |
f3cf586d | 2898 | |
c690b20a ZJS |
2899 | return 2; /* Finito. */ |
2900 | } | |
94aa7071 | 2901 | |
c690b20a ZJS |
2902 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2903 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
2904 | Phase phase; | |
2905 | DnsAnswerFlags flags; | |
2906 | int r; | |
202b76ae | 2907 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 2908 | |
c690b20a | 2909 | assert(t); |
94aa7071 | 2910 | |
c690b20a ZJS |
2911 | /* We have now collected all DS and DNSKEY RRs in |
2912 | * t->validated_keys, let's see which RRs we can now | |
2913 | * authenticate with that. */ | |
94aa7071 | 2914 | |
c690b20a ZJS |
2915 | if (t->scope->dnssec_mode == DNSSEC_NO) |
2916 | return 0; | |
a150ff5e | 2917 | |
c690b20a ZJS |
2918 | /* Already validated */ |
2919 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
2920 | return 0; | |
105e1512 | 2921 | |
c690b20a ZJS |
2922 | /* Our own stuff needs no validation */ |
2923 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
2924 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
2925 | t->answer_authenticated = true; | |
2926 | return 0; | |
2927 | } | |
a150ff5e | 2928 | |
c690b20a ZJS |
2929 | /* Cached stuff is not affected by validation. */ |
2930 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2931 | return 0; | |
f3cf586d | 2932 | |
c690b20a ZJS |
2933 | if (!dns_transaction_dnssec_supported_full(t)) { |
2934 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2935 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 2936 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
2937 | return 0; |
2938 | } | |
f3cf586d | 2939 | |
202b76ae ZJS |
2940 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
2941 | t->id, | |
2942 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 2943 | |
c690b20a ZJS |
2944 | /* First, see if this response contains any revoked trust |
2945 | * anchors we care about */ | |
2946 | r = dns_transaction_check_revoked_trust_anchors(t); | |
2947 | if (r < 0) | |
2948 | return r; | |
43e6779a | 2949 | |
c690b20a ZJS |
2950 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
2951 | r = dns_transaction_copy_validated(t); | |
2952 | if (r < 0) | |
2953 | return r; | |
43e6779a | 2954 | |
c690b20a ZJS |
2955 | /* Second, see if there are DNSKEYs we already know a |
2956 | * validated DS for. */ | |
2957 | r = dns_transaction_validate_dnskey_by_ds(t); | |
2958 | if (r < 0) | |
2959 | return r; | |
43e6779a | 2960 | |
c690b20a ZJS |
2961 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
2962 | * anchor says are revoked. After all we might have marked | |
2963 | * some keys revoked above, but they might still be lingering | |
2964 | * in our validated_keys list. */ | |
2965 | r = dns_transaction_invalidate_revoked_keys(t); | |
2966 | if (r < 0) | |
2967 | return r; | |
f3cf586d | 2968 | |
c690b20a ZJS |
2969 | phase = DNSSEC_PHASE_DNSKEY; |
2970 | for (;;) { | |
2971 | bool have_nsec = false; | |
f3cf586d | 2972 | |
c690b20a ZJS |
2973 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
2974 | if (r <= 0) | |
2975 | return r; | |
547973de | 2976 | |
c690b20a ZJS |
2977 | /* Try again as long as we managed to achieve something */ |
2978 | if (r == 1) | |
547973de LP |
2979 | continue; |
2980 | ||
c690b20a | 2981 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 2982 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 2983 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
2984 | continue; |
2985 | } | |
2986 | ||
c690b20a ZJS |
2987 | if (phase != DNSSEC_PHASE_ALL) { |
2988 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
2989 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
2990 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 2991 | continue; |
547973de LP |
2992 | } |
2993 | ||
56352fe9 | 2994 | /* We're done */ |
547973de LP |
2995 | break; |
2996 | } | |
2997 | ||
2998 | dns_answer_unref(t->answer); | |
2999 | t->answer = validated; | |
3000 | validated = NULL; | |
3001 | ||
72667f08 LP |
3002 | /* At this point the answer only contains validated |
3003 | * RRsets. Now, let's see if it actually answers the question | |
3004 | * we asked. If so, great! If it doesn't, then see if | |
3005 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3006 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3007 | if (r > 0) { |
105e1512 LP |
3008 | /* Yes, it answers the question! */ |
3009 | ||
3010 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3011 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3012 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3013 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3014 | t->answer_authenticated = true; | |
3015 | } else { | |
3016 | /* The answer is not fully authenticated. */ | |
019036a4 | 3017 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3018 | t->answer_authenticated = false; |
3019 | } | |
3020 | ||
72667f08 LP |
3021 | } else if (r == 0) { |
3022 | DnssecNsecResult nr; | |
ed29bfdc | 3023 | bool authenticated = false; |
72667f08 LP |
3024 | |
3025 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3026 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3027 | if (r < 0) |
3028 | return r; | |
3029 | ||
3030 | switch (nr) { | |
3031 | ||
3032 | case DNSSEC_NSEC_NXDOMAIN: | |
3033 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3034 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3035 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3036 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3037 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3038 | |
59c5b597 | 3039 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3040 | break; |
3041 | ||
3042 | case DNSSEC_NSEC_NODATA: | |
3043 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3044 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3045 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3046 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3047 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3048 | |
59c5b597 | 3049 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3050 | break; |
3051 | ||
105e1512 LP |
3052 | case DNSSEC_NSEC_OPTOUT: |
3053 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3054 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3055 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3056 | t->answer_authenticated = false; |
7aa8ce98 | 3057 | |
59c5b597 | 3058 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3059 | break; |
3060 | ||
72667f08 LP |
3061 | case DNSSEC_NSEC_NO_RR: |
3062 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3063 | |
3064 | r = dns_transaction_requires_nsec(t); | |
3065 | if (r < 0) | |
3066 | return r; | |
7aa8ce98 | 3067 | if (r > 0) { |
019036a4 | 3068 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3069 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3070 | } else { |
019036a4 | 3071 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3072 | t->answer_authenticated = false; |
59c5b597 | 3073 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3074 | } |
3075 | ||
3076 | break; | |
3077 | ||
3078 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3079 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3080 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3081 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3082 | break; |
3083 | ||
3084 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3085 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3086 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3087 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3088 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3089 | break; |
3090 | ||
3091 | default: | |
3092 | assert_not_reached("Unexpected NSEC result."); | |
3093 | } | |
3094 | } | |
3095 | ||
547973de LP |
3096 | return 1; |
3097 | } | |
3098 | ||
ec2c5e43 LP |
3099 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3100 | [DNS_TRANSACTION_NULL] = "null", | |
3101 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3102 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3103 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3104 | [DNS_TRANSACTION_SUCCESS] = "success", |
3105 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3106 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3107 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3108 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3109 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3110 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3111 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3112 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3113 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3114 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3115 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3116 | }; |
3117 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3118 | |
3119 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3120 | [DNS_TRANSACTION_NETWORK] = "network", | |
3121 | [DNS_TRANSACTION_CACHE] = "cache", | |
3122 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3123 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3124 | }; |
3125 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |