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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); | |
f7014757 | 366 | |
35aa04e9 LP |
367 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
368 | dns_transaction_notify(d, t); | |
369 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
370 | |
371 | t->block_gc--; | |
ec2c5e43 LP |
372 | dns_transaction_gc(t); |
373 | } | |
374 | ||
519ef046 LP |
375 | static int dns_transaction_pick_server(DnsTransaction *t) { |
376 | DnsServer *server; | |
377 | ||
378 | assert(t); | |
379 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
380 | ||
d001e0a3 LP |
381 | /* Pick a DNS server and a feature level for it. */ |
382 | ||
519ef046 LP |
383 | server = dns_scope_get_dns_server(t->scope); |
384 | if (!server) | |
385 | return -ESRCH; | |
386 | ||
d001e0a3 LP |
387 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
388 | * different properties. */ | |
389 | if (server != t->server) | |
390 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
391 | ||
274b8748 | 392 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 393 | |
d001e0a3 LP |
394 | /* Clamp the feature level if that is requested. */ |
395 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
396 | t->current_feature_level > t->clamp_feature_level) | |
397 | t->current_feature_level = t->clamp_feature_level; | |
398 | ||
399 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
400 | ||
519ef046 LP |
401 | if (server == t->server) |
402 | return 0; | |
403 | ||
404 | dns_server_unref(t->server); | |
405 | t->server = dns_server_ref(server); | |
406 | ||
d001e0a3 LP |
407 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
408 | ||
519ef046 LP |
409 | return 1; |
410 | } | |
411 | ||
d001e0a3 | 412 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
413 | int r; |
414 | ||
415 | assert(t); | |
416 | ||
417 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
418 | ||
419 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
420 | if (next_server) |
421 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
422 | |
423 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
424 | if (r < 0) { |
425 | t->answer_errno = -r; | |
426 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
427 | } | |
8d10d620 LP |
428 | } |
429 | ||
c02cf2f4 | 430 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
431 | int r; |
432 | ||
c02cf2f4 LP |
433 | assert(t); |
434 | ||
5278bbfe LP |
435 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
436 | ||
c02cf2f4 LP |
437 | if (!t->server) |
438 | return 0; | |
439 | ||
440 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
441 | return 0; | |
442 | ||
443 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
444 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
445 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
446 | OPT RR or DO bit. One of these cases is documented here, for example: | |
447 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
448 | ||
4dd15077 LP |
449 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
450 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
451 | |
452 | r = dns_transaction_go(t); | |
453 | if (r < 0) | |
454 | return r; | |
455 | ||
456 | return 1; | |
c02cf2f4 LP |
457 | } |
458 | ||
ec2c5e43 LP |
459 | static int on_stream_complete(DnsStream *s, int error) { |
460 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
461 | DnsTransaction *t; | |
462 | ||
463 | assert(s); | |
464 | assert(s->transaction); | |
465 | ||
466 | /* Copy the data we care about out of the stream before we | |
467 | * destroy it. */ | |
468 | t = s->transaction; | |
469 | p = dns_packet_ref(s->read_packet); | |
470 | ||
b30bf55d | 471 | dns_transaction_close_connection(t); |
ec2c5e43 | 472 | |
a1a3f73a LP |
473 | if (ERRNO_IS_DISCONNECT(error)) { |
474 | usec_t usec; | |
475 | ||
0791110f LP |
476 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
477 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
478 | * question on this scope. */ | |
479 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
480 | return 0; | |
481 | } | |
482 | ||
92ec902a | 483 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 484 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 485 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a | 486 | |
d001e0a3 | 487 | dns_transaction_retry(t, true); |
ac720200 LP |
488 | return 0; |
489 | } | |
ec2c5e43 | 490 | if (error != 0) { |
7cc6ed7b LP |
491 | t->answer_errno = error; |
492 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
493 | return 0; |
494 | } | |
495 | ||
a4076574 | 496 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 497 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
498 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
499 | return 0; | |
500 | } | |
501 | ||
502 | dns_scope_check_conflicts(t->scope, p); | |
503 | ||
ec2c5e43 LP |
504 | t->block_gc++; |
505 | dns_transaction_process_reply(t, p); | |
506 | t->block_gc--; | |
507 | ||
519ef046 LP |
508 | /* If the response wasn't useful, then complete the transition |
509 | * now. After all, we are the worst feature set now with TCP | |
510 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
511 | if (t->state == DNS_TRANSACTION_PENDING) |
512 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
513 | else |
514 | dns_transaction_gc(t); | |
ec2c5e43 LP |
515 | |
516 | return 0; | |
517 | } | |
518 | ||
519 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
520 | _cleanup_close_ int fd = -1; | |
521 | int r; | |
522 | ||
523 | assert(t); | |
524 | ||
519ef046 | 525 | dns_transaction_close_connection(t); |
ec2c5e43 | 526 | |
106784eb | 527 | switch (t->scope->protocol) { |
519ef046 | 528 | |
106784eb | 529 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
530 | r = dns_transaction_pick_server(t); |
531 | if (r < 0) | |
532 | return r; | |
533 | ||
92ec902a | 534 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
535 | return -EOPNOTSUPP; |
536 | ||
274b8748 | 537 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
538 | if (r < 0) |
539 | return r; | |
540 | ||
541 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 542 | break; |
ec2c5e43 | 543 | |
106784eb | 544 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 545 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 546 | if (t->received) |
519ef046 | 547 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
548 | else { |
549 | union in_addr_union address; | |
a7f7d1bd | 550 | int family = AF_UNSPEC; |
ec2c5e43 LP |
551 | |
552 | /* Otherwise, try to talk to the owner of a | |
553 | * the IP address, in case this is a reverse | |
554 | * PTR lookup */ | |
f52e61da | 555 | |
1c02e7ba | 556 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
557 | if (r < 0) |
558 | return r; | |
559 | if (r == 0) | |
560 | return -EINVAL; | |
9e08a6e0 | 561 | if (family != t->scope->family) |
9318cdd3 | 562 | return -ESRCH; |
ec2c5e43 | 563 | |
519ef046 | 564 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 565 | } |
106784eb DM |
566 | |
567 | break; | |
568 | ||
569 | default: | |
ec2c5e43 | 570 | return -EAFNOSUPPORT; |
106784eb | 571 | } |
ec2c5e43 LP |
572 | |
573 | if (fd < 0) | |
574 | return fd; | |
575 | ||
576 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
577 | if (r < 0) | |
578 | return r; | |
ec2c5e43 LP |
579 | fd = -1; |
580 | ||
581 | r = dns_stream_write_packet(t->stream, t->sent); | |
582 | if (r < 0) { | |
b30bf55d | 583 | t->stream = dns_stream_unref(t->stream); |
ec2c5e43 LP |
584 | return r; |
585 | } | |
586 | ||
ec2c5e43 LP |
587 | t->stream->complete = on_stream_complete; |
588 | t->stream->transaction = t; | |
589 | ||
590 | /* The interface index is difficult to determine if we are | |
591 | * connecting to the local host, hence fill this in right away | |
592 | * instead of determining it from the socket */ | |
97ebebbc | 593 | t->stream->ifindex = dns_scope_ifindex(t->scope); |
ec2c5e43 | 594 | |
519ef046 LP |
595 | dns_transaction_reset_answer(t); |
596 | ||
cbe4216d LP |
597 | t->tried_stream = true; |
598 | ||
ec2c5e43 LP |
599 | return 0; |
600 | } | |
601 | ||
547973de | 602 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
603 | assert(t); |
604 | ||
605 | /* For mDNS we cache whenever we get the packet, rather than | |
606 | * in each transaction. */ | |
607 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
608 | return; | |
609 | ||
ceeddf79 MP |
610 | /* Caching disabled? */ |
611 | if (!t->scope->manager->enable_cache) | |
612 | return; | |
613 | ||
547973de LP |
614 | /* We never cache if this packet is from the local host, under |
615 | * the assumption that a locally running DNS server would | |
616 | * cache this anyway, and probably knows better when to flush | |
617 | * the cache then we could. */ | |
618 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
619 | return; | |
620 | ||
547973de LP |
621 | dns_cache_put(&t->scope->cache, |
622 | t->key, | |
623 | t->answer_rcode, | |
624 | t->answer, | |
547973de | 625 | t->answer_authenticated, |
d3760be0 | 626 | t->answer_nsec_ttl, |
547973de LP |
627 | 0, |
628 | t->received->family, | |
629 | &t->received->sender); | |
630 | } | |
631 | ||
105e1512 LP |
632 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
633 | DnsTransaction *dt; | |
634 | Iterator i; | |
635 | ||
636 | assert(t); | |
637 | ||
638 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
639 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
640 | return true; | |
641 | ||
642 | return false; | |
643 | } | |
644 | ||
942eb2e7 LP |
645 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
646 | DnsTransaction *dt; | |
647 | Iterator i; | |
648 | ||
649 | assert(t); | |
650 | ||
651 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
652 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
653 | ||
654 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
655 | ||
656 | switch (dt->state) { | |
657 | ||
658 | case DNS_TRANSACTION_NULL: | |
659 | case DNS_TRANSACTION_PENDING: | |
660 | case DNS_TRANSACTION_VALIDATING: | |
661 | /* Still ongoing */ | |
662 | return 0; | |
663 | ||
664 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 665 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
666 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
667 | goto fail; | |
668 | } | |
669 | ||
b3c6b00a LP |
670 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
671 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
672 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
673 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
674 | |
675 | case DNS_TRANSACTION_SUCCESS: | |
676 | /* All good. */ | |
677 | break; | |
678 | ||
679 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
680 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
681 | * validationr result */ | |
682 | ||
683 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
684 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
685 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
686 | return 0; | |
687 | ||
688 | ||
689 | default: | |
690 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
691 | goto fail; | |
692 | } | |
693 | } | |
694 | ||
695 | /* All is ready, we can go and validate */ | |
696 | return 1; | |
697 | ||
698 | fail: | |
699 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
700 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
701 | return 0; | |
702 | } | |
703 | ||
547973de LP |
704 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
705 | int r; | |
706 | ||
707 | assert(t); | |
708 | ||
709 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 710 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
711 | if (r < 0) |
712 | goto fail; | |
942eb2e7 | 713 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
714 | return; |
715 | ||
c02cf2f4 LP |
716 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
717 | * restart the lookup immediately. */ | |
718 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
719 | if (r < 0) |
720 | goto fail; | |
c02cf2f4 LP |
721 | if (r > 0) /* Transaction got restarted... */ |
722 | return; | |
723 | ||
547973de LP |
724 | /* All our auxiliary DNSSEC transactions are complete now. Try |
725 | * to validate our RRset now. */ | |
726 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
727 | if (r == -EBADMSG) { |
728 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
729 | return; | |
730 | } | |
7cc6ed7b LP |
731 | if (r < 0) |
732 | goto fail; | |
547973de | 733 | |
b652d4a2 LP |
734 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
735 | t->scope->dnssec_mode == DNSSEC_YES) { | |
736 | /* We are not in automatic downgrade mode, and the | |
737 | * server is bad, refuse operation. */ | |
738 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
739 | return; | |
740 | } | |
741 | ||
019036a4 | 742 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
743 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
744 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
745 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
746 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
747 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
748 | return; | |
749 | } | |
750 | ||
1e02e182 LP |
751 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
752 | dns_server_warn_downgrade(t->server); | |
753 | ||
547973de LP |
754 | dns_transaction_cache_answer(t); |
755 | ||
756 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
757 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
758 | else | |
3bbdc31d | 759 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
760 | |
761 | return; | |
762 | ||
763 | fail: | |
764 | t->answer_errno = -r; | |
765 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
766 | } |
767 | ||
eac7cda2 LP |
768 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
769 | int r; | |
770 | ||
771 | assert(t); | |
772 | ||
773 | /* Checks whether the answer is positive, i.e. either a direct | |
774 | * answer to the question, or a CNAME/DNAME for it */ | |
775 | ||
776 | r = dns_answer_match_key(t->answer, t->key, flags); | |
777 | if (r != 0) | |
778 | return r; | |
779 | ||
780 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
781 | if (r != 0) | |
782 | return r; | |
783 | ||
784 | return false; | |
785 | } | |
786 | ||
787 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
788 | int r; | |
789 | ||
790 | assert(t); | |
791 | ||
792 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
793 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
794 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
795 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
796 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
797 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
798 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
799 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
800 | * incomplete CNAME/DNAME chain. | |
801 | * | |
802 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
803 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
804 | * lookup. */ | |
805 | ||
806 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
807 | return 0; | |
808 | ||
809 | r = dns_transaction_has_positive_answer(t, NULL); | |
810 | if (r <= 0) | |
811 | return r; | |
812 | ||
813 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
814 | return 0; | |
815 | } | |
816 | ||
ec2c5e43 | 817 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 818 | usec_t ts; |
ec2c5e43 LP |
819 | int r; |
820 | ||
821 | assert(t); | |
822 | assert(p); | |
9df3ba6c TG |
823 | assert(t->scope); |
824 | assert(t->scope->manager); | |
ec2c5e43 | 825 | |
5a7e41a3 LP |
826 | if (t->state != DNS_TRANSACTION_PENDING) |
827 | return; | |
828 | ||
ec2c5e43 LP |
829 | /* Note that this call might invalidate the query. Callers |
830 | * should hence not attempt to access the query or transaction | |
831 | * after calling this function. */ | |
832 | ||
b5efcf29 LP |
833 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
834 | ||
106784eb | 835 | switch (t->scope->protocol) { |
b5efcf29 | 836 | |
106784eb | 837 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 838 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 839 | |
97ebebbc | 840 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
841 | return; |
842 | ||
843 | if (p->family != t->scope->family) | |
844 | return; | |
845 | ||
846 | /* Tentative packets are not full responses but still | |
847 | * useful for identifying uniqueness conflicts during | |
848 | * probing. */ | |
8b757a38 | 849 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
850 | dns_transaction_tentative(t, p); |
851 | return; | |
852 | } | |
106784eb DM |
853 | |
854 | break; | |
855 | ||
4e5bf5e1 | 856 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 857 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
858 | |
859 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
860 | return; |
861 | ||
862 | if (p->family != t->scope->family) | |
863 | return; | |
864 | ||
865 | break; | |
866 | ||
106784eb | 867 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
868 | /* Note that we do not need to verify the |
869 | * addresses/port numbers of incoming traffic, as we | |
870 | * invoked connect() on our UDP socket in which case | |
871 | * the kernel already does the needed verification for | |
872 | * us. */ | |
106784eb DM |
873 | break; |
874 | ||
875 | default: | |
9c56a6f3 | 876 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
877 | } |
878 | ||
ec2c5e43 LP |
879 | if (t->received != p) { |
880 | dns_packet_unref(t->received); | |
881 | t->received = dns_packet_ref(p); | |
882 | } | |
883 | ||
c3bc53e6 LP |
884 | t->answer_source = DNS_TRANSACTION_NETWORK; |
885 | ||
ec2c5e43 LP |
886 | if (p->ipproto == IPPROTO_TCP) { |
887 | if (DNS_PACKET_TC(p)) { | |
888 | /* Truncated via TCP? Somebody must be fucking with us */ | |
889 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
890 | return; | |
891 | } | |
892 | ||
893 | if (DNS_PACKET_ID(p) != t->id) { | |
894 | /* Not the reply to our query? Somebody must be fucking with us */ | |
895 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
896 | return; | |
897 | } | |
898 | } | |
899 | ||
38a03f06 | 900 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
901 | |
902 | switch (t->scope->protocol) { | |
8af5b883 | 903 | |
9df3ba6c TG |
904 | case DNS_PROTOCOL_DNS: |
905 | assert(t->server); | |
906 | ||
4e0b8b17 TG |
907 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
908 | ||
8af5b883 | 909 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 910 | |
d001e0a3 LP |
911 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_WORST) { |
912 | /* This was already at the lowest possible feature level? If so, we can't downgrade | |
913 | * this transaction anymore, hence let's process the response, and accept the rcode. */ | |
914 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); | |
915 | break; | |
916 | } | |
917 | ||
918 | /* Reduce this feature level by one and try again. */ | |
919 | t->clamp_feature_level = t->current_feature_level - 1; | |
920 | ||
921 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
922 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
923 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
924 | ||
925 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 926 | return; |
6bb2c085 | 927 | } else if (DNS_PACKET_TC(p)) |
274b8748 | 928 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
929 | |
930 | break; | |
8af5b883 | 931 | |
9df3ba6c TG |
932 | case DNS_PROTOCOL_LLMNR: |
933 | case DNS_PROTOCOL_MDNS: | |
934 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 935 | break; |
8af5b883 | 936 | |
9df3ba6c | 937 | default: |
8af5b883 | 938 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
939 | } |
940 | ||
ec2c5e43 | 941 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
942 | |
943 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
944 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
945 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
946 | return; | |
947 | } | |
948 | ||
f757cd85 LP |
949 | log_debug("Reply truncated, retrying via TCP."); |
950 | ||
ec2c5e43 LP |
951 | /* Response was truncated, let's try again with good old TCP */ |
952 | r = dns_transaction_open_tcp(t); | |
953 | if (r == -ESRCH) { | |
954 | /* No servers found? Damn! */ | |
955 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
956 | return; | |
957 | } | |
91adc4db LP |
958 | if (r == -EOPNOTSUPP) { |
959 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
960 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
961 | return; | |
962 | } | |
ec2c5e43 | 963 | if (r < 0) { |
8af5b883 | 964 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 965 | * we immediately give up */ |
7cc6ed7b LP |
966 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
967 | goto fail; | |
ec2c5e43 LP |
968 | |
969 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 970 | dns_transaction_retry(t, true); |
ec2c5e43 | 971 | } |
2a6658ef LP |
972 | |
973 | return; | |
ec2c5e43 LP |
974 | } |
975 | ||
de54e62b | 976 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
977 | r = dns_packet_extract(p); |
978 | if (r < 0) { | |
979 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
980 | return; | |
981 | } | |
982 | ||
ed9717fc | 983 | if (t->server) { |
d001e0a3 LP |
984 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
985 | * rcode and subsequently downgraded the protocol */ | |
986 | ||
987 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
988 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
989 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
990 | ||
991 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
992 | if (!p->opt) |
993 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
994 | ||
d001e0a3 | 995 | /* Report that we successfully received a packet */ |
ed9717fc LP |
996 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); |
997 | } | |
de54e62b | 998 | |
c02cf2f4 LP |
999 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1000 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1001 | if (r < 0) |
1002 | goto fail; | |
c02cf2f4 LP |
1003 | if (r > 0) /* Transaction got restarted... */ |
1004 | return; | |
1005 | ||
8b419837 DR |
1006 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
1007 | ||
1008 | /* When dealing with protocols other than mDNS only consider responses with | |
1009 | * equivalent query section to the request. For mDNS this check doesn't make | |
1010 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1011 | * contain any questions in the Question Section". */ | |
1012 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1013 | r = dns_packet_is_reply_for(p, t->key); | |
1014 | if (r < 0) | |
1015 | goto fail; | |
1016 | if (r == 0) { | |
1017 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1018 | return; | |
1019 | } | |
547493c5 | 1020 | } |
29815b6c | 1021 | |
547493c5 DM |
1022 | /* Install the answer as answer to the transaction */ |
1023 | dns_answer_unref(t->answer); | |
1024 | t->answer = dns_answer_ref(p->answer); | |
1025 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1026 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1027 | t->answer_authenticated = false; |
79e24931 | 1028 | |
eac7cda2 LP |
1029 | r = dns_transaction_fix_rcode(t); |
1030 | if (r < 0) | |
1031 | goto fail; | |
1032 | ||
51e399bc LP |
1033 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1034 | t->block_gc++; | |
547973de | 1035 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1036 | t->block_gc--; |
1037 | ||
1038 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1039 | if (!dns_transaction_gc(t)) | |
1040 | return; | |
1041 | ||
1042 | /* Requesting additional keys might have resulted in | |
1043 | * this transaction to fail, since the auxiliary | |
1044 | * request failed for some reason. If so, we are not | |
1045 | * in pending state anymore, and we should exit | |
1046 | * quickly. */ | |
1047 | if (t->state != DNS_TRANSACTION_PENDING) | |
1048 | return; | |
7cc6ed7b LP |
1049 | if (r < 0) |
1050 | goto fail; | |
547973de LP |
1051 | if (r > 0) { |
1052 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1053 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1054 | dns_transaction_close_connection(t); |
1055 | dns_transaction_stop_timeout(t); | |
547973de LP |
1056 | return; |
1057 | } | |
547493c5 | 1058 | } |
ec2c5e43 | 1059 | |
547973de | 1060 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1061 | return; |
1062 | ||
1063 | fail: | |
1064 | t->answer_errno = -r; | |
1065 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1066 | } |
1067 | ||
c19ffd9f TG |
1068 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1069 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1070 | DnsTransaction *t = userdata; | |
1071 | int r; | |
1072 | ||
1073 | assert(t); | |
1074 | assert(t->scope); | |
1075 | ||
1076 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1077 | if (ERRNO_IS_DISCONNECT(-r)) { |
1078 | usec_t usec; | |
c19ffd9f | 1079 | |
7e1851e3 LP |
1080 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1081 | * recvmsg(). Treat this like a lost packet. */ | |
1082 | ||
92ec902a | 1083 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1084 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1085 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 | 1086 | |
d001e0a3 | 1087 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1088 | return 0; |
1089 | } | |
1090 | if (r < 0) { | |
7cc6ed7b LP |
1091 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1092 | t->answer_errno = -r; | |
7e1851e3 LP |
1093 | return 0; |
1094 | } | |
1095 | ||
1096 | r = dns_packet_validate_reply(p); | |
1097 | if (r < 0) { | |
1098 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1099 | return 0; | |
1100 | } | |
1101 | if (r == 0) { | |
e09f605e | 1102 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1103 | return 0; |
1104 | } | |
1105 | ||
1106 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1107 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1108 | return 0; |
1109 | } | |
c19ffd9f | 1110 | |
7e1851e3 | 1111 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1112 | return 0; |
1113 | } | |
1114 | ||
49cce12d | 1115 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1116 | int r; |
1117 | ||
1118 | assert(t); | |
c19ffd9f | 1119 | |
519ef046 | 1120 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1121 | |
519ef046 | 1122 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1123 | if (r < 0) |
1124 | return r; | |
c19ffd9f | 1125 | |
274b8748 | 1126 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
519ef046 LP |
1127 | return -EAGAIN; |
1128 | ||
92ec902a | 1129 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1130 | return -EOPNOTSUPP; |
1131 | ||
519ef046 LP |
1132 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1133 | int fd; | |
1134 | ||
1135 | dns_transaction_close_connection(t); | |
c19ffd9f | 1136 | |
519ef046 LP |
1137 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1138 | if (fd < 0) | |
1139 | return fd; | |
1140 | ||
1141 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1142 | if (r < 0) { | |
1143 | safe_close(fd); | |
1144 | return r; | |
1145 | } | |
1146 | ||
aa4a9deb | 1147 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1148 | t->dns_udp_fd = fd; |
1149 | } | |
1150 | ||
274b8748 | 1151 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1152 | if (r < 0) |
1153 | return r; | |
1154 | } else | |
1155 | dns_transaction_close_connection(t); | |
1156 | ||
1157 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1158 | if (r < 0) |
1159 | return r; | |
c19ffd9f | 1160 | |
519ef046 | 1161 | dns_transaction_reset_answer(t); |
be808ea0 | 1162 | |
471d40d9 | 1163 | return 0; |
c19ffd9f TG |
1164 | } |
1165 | ||
ec2c5e43 LP |
1166 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1167 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1168 | |
1169 | assert(s); | |
1170 | assert(t); | |
1171 | ||
ef7ce6df DM |
1172 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1173 | /* Timeout reached? Increase the timeout for the server used */ | |
1174 | switch (t->scope->protocol) { | |
49cce12d | 1175 | |
ef7ce6df DM |
1176 | case DNS_PROTOCOL_DNS: |
1177 | assert(t->server); | |
274b8748 | 1178 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1179 | break; |
49cce12d | 1180 | |
ef7ce6df DM |
1181 | case DNS_PROTOCOL_LLMNR: |
1182 | case DNS_PROTOCOL_MDNS: | |
1183 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1184 | break; |
49cce12d | 1185 | |
ef7ce6df DM |
1186 | default: |
1187 | assert_not_reached("Invalid DNS protocol."); | |
1188 | } | |
1189 | ||
1190 | if (t->initial_jitter_scheduled) | |
1191 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1192 | } |
1193 | ||
423659ab LP |
1194 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1195 | ||
d001e0a3 | 1196 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1197 | return 0; |
1198 | } | |
1199 | ||
9df3ba6c TG |
1200 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1201 | assert(t); | |
1202 | assert(t->scope); | |
1203 | ||
1204 | switch (t->scope->protocol) { | |
49cce12d | 1205 | |
9df3ba6c TG |
1206 | case DNS_PROTOCOL_DNS: |
1207 | assert(t->server); | |
9df3ba6c | 1208 | return t->server->resend_timeout; |
49cce12d | 1209 | |
9df3ba6c | 1210 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
1211 | assert(t->n_attempts > 0); |
1212 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1213 | |
11a27c2e | 1214 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1215 | return t->scope->resend_timeout; |
49cce12d | 1216 | |
9df3ba6c TG |
1217 | default: |
1218 | assert_not_reached("Invalid DNS protocol."); | |
1219 | } | |
1220 | } | |
1221 | ||
c842ff24 | 1222 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1223 | int r; |
1224 | ||
1225 | assert(t); | |
1226 | ||
f535705a | 1227 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1228 | |
edbcc1fd LP |
1229 | r = dns_scope_network_good(t->scope); |
1230 | if (r < 0) | |
1231 | return r; | |
1232 | if (r == 0) { | |
1233 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1234 | return 0; | |
1235 | } | |
1236 | ||
ec2c5e43 LP |
1237 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1238 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1239 | return 0; | |
1240 | } | |
1241 | ||
cbe4216d | 1242 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1243 | /* If we already tried via a stream, then we don't |
1244 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1245 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1246 | return 0; | |
1247 | } | |
1248 | ||
1249 | t->n_attempts++; | |
9df3ba6c | 1250 | t->start_usec = ts; |
c61d2b44 LP |
1251 | |
1252 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1253 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1254 | |
0d2cd476 LP |
1255 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1256 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1257 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1258 | if (r < 0) |
1259 | return r; | |
1260 | if (r > 0) { | |
1261 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1262 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1263 | t->answer_authenticated = true; |
0d2cd476 LP |
1264 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1265 | return 0; | |
1266 | } | |
b2b796b8 | 1267 | |
1c02e7ba | 1268 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1269 | t->key->type == DNS_TYPE_DS) { |
1270 | ||
1271 | /* Hmm, this is a request for the root DS? A | |
1272 | * DS RR doesn't exist in the root zone, and | |
1273 | * if our trust anchor didn't know it either, | |
1274 | * this means we cannot do any DNSSEC logic | |
1275 | * anymore. */ | |
1276 | ||
1ed8c0fb | 1277 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1278 | /* We are in downgrade mode. In this |
1279 | * case, synthesize an unsigned empty | |
1280 | * response, so that the any lookup | |
1281 | * depending on this one can continue | |
1282 | * assuming there was no DS, and hence | |
1283 | * the root zone was unsigned. */ | |
1284 | ||
1285 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1286 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1287 | t->answer_authenticated = false; | |
1288 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1289 | } else | |
1290 | /* If we are not in downgrade mode, | |
1291 | * then fail the lookup, because we | |
1292 | * cannot reasonably answer it. There | |
1293 | * might be DS RRs, but we don't know | |
1294 | * them, and the DNS server won't tell | |
1295 | * them to us (and even if it would, | |
202b76ae | 1296 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1297 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1298 | ||
1299 | return 0; | |
1300 | } | |
0d2cd476 LP |
1301 | } |
1302 | ||
1303 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1304 | * for probing or verifying a zone item. */ |
547973de | 1305 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1306 | |
97ebebbc | 1307 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1308 | if (r < 0) |
1309 | return r; | |
1310 | if (r > 0) { | |
ae6a4bbf | 1311 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1312 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1313 | t->answer_authenticated = true; |
d746bb3e LP |
1314 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1315 | return 0; | |
1316 | } | |
1317 | } | |
1318 | ||
4d926a69 LP |
1319 | /* Check the cache, but only if this transaction is not used |
1320 | * for probing or verifying a zone item. */ | |
547973de | 1321 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1322 | |
4d926a69 LP |
1323 | /* Before trying the cache, let's make sure we figured out a |
1324 | * server to use. Should this cause a change of server this | |
1325 | * might flush the cache. */ | |
1326 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 1327 | |
4d926a69 LP |
1328 | /* Let's then prune all outdated entries */ |
1329 | dns_cache_prune(&t->scope->cache); | |
1330 | ||
17c8de63 | 1331 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1332 | if (r < 0) |
1333 | return r; | |
1334 | if (r > 0) { | |
c3bc53e6 | 1335 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1336 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1337 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1338 | else | |
3bbdc31d | 1339 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1340 | return 0; |
1341 | } | |
ec2c5e43 LP |
1342 | } |
1343 | ||
1effe965 DM |
1344 | return 1; |
1345 | } | |
1346 | ||
0afa57e2 DM |
1347 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1348 | ||
1349 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1350 | bool add_known_answers = false; |
0afa57e2 DM |
1351 | DnsTransaction *other; |
1352 | unsigned qdcount; | |
1353 | usec_t ts; | |
1354 | int r; | |
1355 | ||
1356 | assert(t); | |
1357 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1358 | ||
e5abebab | 1359 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1360 | t->sent = dns_packet_unref(t->sent); |
1361 | ||
1362 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1363 | if (r < 0) | |
1364 | return r; | |
1365 | ||
1366 | r = dns_packet_append_key(p, t->key, NULL); | |
1367 | if (r < 0) | |
1368 | return r; | |
1369 | ||
1370 | qdcount = 1; | |
1371 | ||
7778dfff DM |
1372 | if (dns_key_is_shared(t->key)) |
1373 | add_known_answers = true; | |
1374 | ||
0afa57e2 DM |
1375 | /* |
1376 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1377 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1378 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1379 | */ | |
1380 | ||
1381 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1382 | ||
1383 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1384 | ||
1385 | /* Skip ourselves */ | |
1386 | if (other == t) | |
1387 | continue; | |
1388 | ||
1389 | if (other->state != DNS_TRANSACTION_PENDING) | |
1390 | continue; | |
1391 | ||
1392 | if (other->next_attempt_after > ts) | |
1393 | continue; | |
1394 | ||
1395 | if (qdcount >= UINT16_MAX) | |
1396 | break; | |
1397 | ||
1398 | r = dns_packet_append_key(p, other->key, NULL); | |
1399 | ||
1400 | /* | |
1401 | * If we can't stuff more questions into the packet, just give up. | |
1402 | * One of the 'other' transactions will fire later and take care of the rest. | |
1403 | */ | |
1404 | if (r == -EMSGSIZE) | |
1405 | break; | |
1406 | ||
1407 | if (r < 0) | |
1408 | return r; | |
1409 | ||
c842ff24 | 1410 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1411 | if (r <= 0) |
1412 | continue; | |
1413 | ||
1414 | ts += transaction_get_resend_timeout(other); | |
1415 | ||
1416 | r = sd_event_add_time( | |
1417 | other->scope->manager->event, | |
1418 | &other->timeout_event_source, | |
1419 | clock_boottime_or_monotonic(), | |
1420 | ts, 0, | |
1421 | on_transaction_timeout, other); | |
1422 | if (r < 0) | |
1423 | return r; | |
1424 | ||
aa4a9deb LP |
1425 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1426 | ||
0afa57e2 DM |
1427 | other->state = DNS_TRANSACTION_PENDING; |
1428 | other->next_attempt_after = ts; | |
1429 | ||
313cefa1 | 1430 | qdcount++; |
7778dfff DM |
1431 | |
1432 | if (dns_key_is_shared(other->key)) | |
1433 | add_known_answers = true; | |
0afa57e2 DM |
1434 | } |
1435 | ||
1436 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1437 | |
7778dfff DM |
1438 | /* Append known answer section if we're asking for any shared record */ |
1439 | if (add_known_answers) { | |
1440 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1441 | if (r < 0) | |
1442 | return r; | |
1443 | } | |
1444 | ||
0afa57e2 DM |
1445 | t->sent = p; |
1446 | p = NULL; | |
1447 | ||
1448 | return 0; | |
1449 | } | |
1450 | ||
1451 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1452 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1453 | int r; | |
1454 | ||
1455 | assert(t); | |
1456 | ||
1457 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1458 | return dns_transaction_make_packet_mdns(t); | |
1459 | ||
1460 | if (t->sent) | |
1461 | return 0; | |
1462 | ||
b652d4a2 | 1463 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1464 | if (r < 0) |
1465 | return r; | |
1466 | ||
0afa57e2 DM |
1467 | r = dns_packet_append_key(p, t->key, NULL); |
1468 | if (r < 0) | |
1469 | return r; | |
1470 | ||
1471 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1472 | DNS_PACKET_HEADER(p)->id = t->id; | |
1473 | ||
1474 | t->sent = p; | |
1475 | p = NULL; | |
1476 | ||
1477 | return 0; | |
1478 | } | |
1479 | ||
1effe965 DM |
1480 | int dns_transaction_go(DnsTransaction *t) { |
1481 | usec_t ts; | |
1482 | int r; | |
202b76ae | 1483 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1484 | |
1485 | assert(t); | |
1486 | ||
5278bbfe LP |
1487 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1488 | * now. */ | |
1489 | ||
1effe965 | 1490 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1491 | |
c842ff24 | 1492 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1493 | if (r <= 0) |
1494 | return r; | |
1495 | ||
202b76ae | 1496 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1497 | t->id, |
202b76ae | 1498 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1499 | dns_protocol_to_string(t->scope->protocol), |
1500 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1501 | af_to_name_short(t->scope->family)); |
1effe965 | 1502 | |
ef7ce6df | 1503 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1504 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1505 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1506 | usec_t jitter, accuracy; | |
6e068472 LP |
1507 | |
1508 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1509 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1510 | ||
ef7ce6df | 1511 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1512 | |
1513 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1514 | |
1515 | switch (t->scope->protocol) { | |
519ef046 | 1516 | |
ea12bcc7 DM |
1517 | case DNS_PROTOCOL_LLMNR: |
1518 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1519 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1520 | break; | |
519ef046 | 1521 | |
ea12bcc7 DM |
1522 | case DNS_PROTOCOL_MDNS: |
1523 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1524 | jitter += MDNS_JITTER_MIN_USEC; | |
1525 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1526 | break; | |
1527 | default: | |
1528 | assert_not_reached("bad protocol"); | |
1529 | } | |
6e068472 LP |
1530 | |
1531 | r = sd_event_add_time( | |
1532 | t->scope->manager->event, | |
1533 | &t->timeout_event_source, | |
1534 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1535 | ts + jitter, accuracy, |
6e068472 LP |
1536 | on_transaction_timeout, t); |
1537 | if (r < 0) | |
1538 | return r; | |
1539 | ||
aa4a9deb LP |
1540 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1541 | ||
6e068472 | 1542 | t->n_attempts = 0; |
a9da14e1 | 1543 | t->next_attempt_after = ts; |
6e068472 LP |
1544 | t->state = DNS_TRANSACTION_PENDING; |
1545 | ||
ea12bcc7 | 1546 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1547 | return 0; |
1548 | } | |
1549 | ||
ec2c5e43 LP |
1550 | /* Otherwise, we need to ask the network */ |
1551 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1552 | if (r < 0) |
1553 | return r; | |
1554 | ||
1555 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1556 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1557 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1558 | |
1559 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1560 | * always be made via TCP on LLMNR */ | |
1561 | r = dns_transaction_open_tcp(t); | |
1562 | } else { | |
be808ea0 TG |
1563 | /* Try via UDP, and if that fails due to large size or lack of |
1564 | * support try via TCP */ | |
49cce12d | 1565 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1566 | if (r == -EMSGSIZE) |
1567 | log_debug("Sending query via TCP since it is too large."); | |
034e8031 LP |
1568 | if (r == -EAGAIN) |
1569 | log_debug("Sending query via TCP since server doesn't support UDP."); | |
be808ea0 | 1570 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1571 | r = dns_transaction_open_tcp(t); |
1572 | } | |
be808ea0 | 1573 | |
ec2c5e43 LP |
1574 | if (r == -ESRCH) { |
1575 | /* No servers to send this to? */ | |
1576 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1577 | return 0; | |
91adc4db LP |
1578 | } |
1579 | if (r == -EOPNOTSUPP) { | |
1580 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1581 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1582 | return 0; | |
1583 | } | |
0791110f | 1584 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1585 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1586 | * answer this request with this protocol. */ |
1587 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1588 | return 0; | |
1589 | } | |
91adc4db | 1590 | if (r < 0) { |
7cc6ed7b LP |
1591 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1592 | return r; | |
13b551ac | 1593 | |
ec2c5e43 | 1594 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1595 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1596 | |
1597 | return dns_transaction_go(t); | |
1598 | } | |
1599 | ||
a9da14e1 DM |
1600 | ts += transaction_get_resend_timeout(t); |
1601 | ||
9a015429 LP |
1602 | r = sd_event_add_time( |
1603 | t->scope->manager->event, | |
1604 | &t->timeout_event_source, | |
1605 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1606 | ts, 0, |
9a015429 | 1607 | on_transaction_timeout, t); |
ec2c5e43 LP |
1608 | if (r < 0) |
1609 | return r; | |
1610 | ||
aa4a9deb LP |
1611 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1612 | ||
ec2c5e43 | 1613 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1614 | t->next_attempt_after = ts; |
1615 | ||
ec2c5e43 LP |
1616 | return 1; |
1617 | } | |
1618 | ||
f2992dc1 LP |
1619 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1620 | DnsTransaction *n; | |
1621 | Iterator i; | |
1622 | int r; | |
1623 | ||
1624 | assert(t); | |
1625 | assert(aux); | |
1626 | ||
1627 | /* Try to find cyclic dependencies between transaction objects */ | |
1628 | ||
1629 | if (t == aux) | |
1630 | return 1; | |
1631 | ||
3eb6aa00 | 1632 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1633 | r = dns_transaction_find_cyclic(t, n); |
1634 | if (r != 0) | |
1635 | return r; | |
1636 | } | |
1637 | ||
3eb6aa00 | 1638 | return 0; |
f2992dc1 LP |
1639 | } |
1640 | ||
547973de LP |
1641 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1642 | DnsTransaction *aux; | |
1643 | int r; | |
1644 | ||
1645 | assert(t); | |
1646 | assert(ret); | |
1647 | assert(key); | |
1648 | ||
1649 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1650 | if (!aux) { | |
1651 | r = dns_transaction_new(&aux, t->scope, key); | |
1652 | if (r < 0) | |
1653 | return r; | |
1654 | } else { | |
1655 | if (set_contains(t->dnssec_transactions, aux)) { | |
1656 | *ret = aux; | |
1657 | return 0; | |
1658 | } | |
f2992dc1 LP |
1659 | |
1660 | r = dns_transaction_find_cyclic(t, aux); | |
1661 | if (r < 0) | |
1662 | return r; | |
1663 | if (r > 0) { | |
202b76ae ZJS |
1664 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1665 | ||
1666 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1667 | aux->id, |
202b76ae | 1668 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1669 | t->id, |
202b76ae ZJS |
1670 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1671 | ||
f2992dc1 LP |
1672 | return -ELOOP; |
1673 | } | |
547973de LP |
1674 | } |
1675 | ||
1676 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1677 | if (r < 0) | |
1678 | goto gc; | |
1679 | ||
1680 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1681 | if (r < 0) | |
35aa04e9 LP |
1682 | goto gc; |
1683 | ||
1684 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1685 | if (r < 0) | |
547973de LP |
1686 | goto gc; |
1687 | ||
1688 | r = set_put(t->dnssec_transactions, aux); | |
1689 | if (r < 0) | |
1690 | goto gc; | |
1691 | ||
1692 | r = set_put(aux->notify_transactions, t); | |
1693 | if (r < 0) { | |
1694 | (void) set_remove(t->dnssec_transactions, aux); | |
1695 | goto gc; | |
1696 | } | |
1697 | ||
1698 | *ret = aux; | |
1699 | return 1; | |
1700 | ||
1701 | gc: | |
1702 | dns_transaction_gc(aux); | |
1703 | return r; | |
1704 | } | |
1705 | ||
1706 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1707 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1708 | DnsTransaction *aux; | |
1709 | int r; | |
1710 | ||
1711 | assert(t); | |
1712 | assert(key); | |
1713 | ||
1714 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1715 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1716 | if (r < 0) |
1717 | return r; | |
1718 | if (r > 0) { | |
1719 | r = dns_answer_extend(&t->validated_keys, a); | |
1720 | if (r < 0) | |
1721 | return r; | |
1722 | ||
1723 | return 0; | |
1724 | } | |
1725 | ||
1726 | /* This didn't work, ask for it via the network/cache then. */ | |
1727 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1728 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1729 | return 0; | |
547973de LP |
1730 | if (r < 0) |
1731 | return r; | |
1732 | ||
1733 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1734 | r = dns_transaction_go(aux); | |
1735 | if (r < 0) | |
1736 | return r; | |
1737 | } | |
1738 | ||
f2992dc1 | 1739 | return 1; |
547973de LP |
1740 | } |
1741 | ||
8a516214 LP |
1742 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1743 | int r; | |
1744 | ||
1745 | assert(t); | |
1746 | ||
c629ff58 | 1747 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1748 | * database, either in the global one, or the link-local |
1749 | * one. */ | |
1750 | ||
1751 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1752 | if (r != 0) | |
1753 | return r; | |
1754 | ||
1755 | if (!t->scope->link) | |
1756 | return 0; | |
1757 | ||
1758 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1759 | } | |
1760 | ||
105e1512 LP |
1761 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1762 | int r; | |
1763 | ||
1764 | assert(t); | |
1765 | ||
1766 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1767 | * RRs to prove it */ | |
1768 | ||
1769 | r = dns_transaction_has_positive_answer(t, NULL); | |
1770 | if (r < 0) | |
1771 | return r; | |
1772 | if (r > 0) | |
1773 | return false; | |
1774 | ||
8e54f5d9 LP |
1775 | /* Is this key explicitly listed as a negative trust anchor? |
1776 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1777 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1778 | if (r < 0) |
1779 | return r; | |
1780 | if (r > 0) | |
1781 | return false; | |
1782 | ||
105e1512 LP |
1783 | /* The answer does not contain any RRs that match to the |
1784 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1785 | * included. If not, the answer is unsigned. */ | |
1786 | ||
1787 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1788 | if (r < 0) | |
1789 | return r; | |
1790 | if (r > 0) | |
1791 | return false; | |
1792 | ||
1793 | return true; | |
1794 | } | |
1795 | ||
1796 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1797 | int r; | |
1798 | ||
1799 | assert(t); | |
1800 | assert(rr); | |
1801 | ||
1802 | /* Check if the specified RR is the "primary" response, | |
1803 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1804 | * CNAME/DNAME for it. */ |
105e1512 LP |
1805 | |
1806 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1807 | if (r != 0) | |
1808 | return r; | |
1809 | ||
4cb94977 | 1810 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1811 | } |
1812 | ||
92ec902a LP |
1813 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1814 | assert(t); | |
1815 | ||
1816 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1817 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1818 | ||
1819 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1820 | return false; | |
1821 | ||
1822 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1823 | * be supported, hence return true. */ | |
1824 | if (!t->server) | |
1825 | return true; | |
1826 | ||
d001e0a3 LP |
1827 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1828 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1829 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1830 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1831 | |
1832 | return dns_server_dnssec_supported(t->server); | |
1833 | } | |
1834 | ||
1835 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1836 | DnsTransaction *dt; | |
1837 | Iterator i; | |
1838 | ||
1839 | assert(t); | |
1840 | ||
1841 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1842 | ||
1843 | if (!dns_transaction_dnssec_supported(t)) | |
1844 | return false; | |
1845 | ||
1846 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1847 | if (!dns_transaction_dnssec_supported(dt)) | |
1848 | return false; | |
1849 | ||
1850 | return true; | |
1851 | } | |
1852 | ||
547973de LP |
1853 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1854 | DnsResourceRecord *rr; | |
105e1512 | 1855 | |
547973de LP |
1856 | int r; |
1857 | ||
1858 | assert(t); | |
1859 | ||
105e1512 LP |
1860 | /* |
1861 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1862 | * we can verify signatures or prove that RRs are rightfully | |
1863 | * unsigned. Specifically: | |
1864 | * | |
1865 | * - For RRSIG we get the matching DNSKEY | |
1866 | * - For DNSKEY we get the matching DS | |
1867 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1868 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 1869 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
1870 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
1871 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
1872 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
1873 | */ | |
1874 | ||
b652d4a2 | 1875 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1876 | return 0; |
92ec902a LP |
1877 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1878 | return 0; /* We only need to validate stuff from the network */ | |
1879 | if (!dns_transaction_dnssec_supported(t)) | |
1880 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1881 | |
547973de LP |
1882 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1883 | ||
105e1512 LP |
1884 | if (dns_type_is_pseudo(rr->key->type)) |
1885 | continue; | |
1886 | ||
8e54f5d9 | 1887 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 1888 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
1889 | if (r < 0) |
1890 | return r; | |
1891 | if (r > 0) | |
1892 | continue; | |
1893 | ||
547973de LP |
1894 | switch (rr->key->type) { |
1895 | ||
1896 | case DNS_TYPE_RRSIG: { | |
1897 | /* For each RRSIG we request the matching DNSKEY */ | |
1898 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1899 | ||
1900 | /* If this RRSIG is about a DNSKEY RR and the | |
1901 | * signer is the same as the owner, then we | |
1902 | * already have the DNSKEY, and we don't have | |
1903 | * to look for more. */ | |
1904 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 1905 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
1906 | if (r < 0) |
1907 | return r; | |
1908 | if (r > 0) | |
1909 | continue; | |
1910 | } | |
1911 | ||
105e1512 LP |
1912 | /* If the signer is not a parent of our |
1913 | * original query, then this is about an | |
1914 | * auxiliary RRset, but not anything we asked | |
1915 | * for. In this case we aren't interested, | |
1916 | * because we don't want to request additional | |
1917 | * RRs for stuff we didn't really ask for, and | |
1918 | * also to avoid request loops, where | |
1919 | * additional RRs from one transaction result | |
1920 | * in another transaction whose additonal RRs | |
1921 | * point back to the original transaction, and | |
1922 | * we deadlock. */ | |
1c02e7ba | 1923 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
1924 | if (r < 0) |
1925 | return r; | |
1926 | if (r == 0) | |
1927 | continue; | |
1928 | ||
1929 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1930 | if (!dnskey) | |
1931 | return -ENOMEM; | |
1932 | ||
1c02e7ba ZJS |
1933 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
1934 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
1935 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1936 | if (r < 0) | |
1937 | return r; | |
1938 | break; | |
1939 | } | |
1940 | ||
1941 | case DNS_TYPE_DNSKEY: { | |
1942 | /* For each DNSKEY we request the matching DS */ | |
1943 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1944 | ||
105e1512 LP |
1945 | /* If the DNSKEY we are looking at is not for |
1946 | * zone we are interested in, nor any of its | |
1947 | * parents, we aren't interested, and don't | |
1948 | * request it. After all, we don't want to end | |
1949 | * up in request loops, and want to keep | |
1950 | * additional traffic down. */ | |
1951 | ||
1c02e7ba | 1952 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
1953 | if (r < 0) |
1954 | return r; | |
1955 | if (r == 0) | |
1956 | continue; | |
1957 | ||
1c02e7ba | 1958 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
1959 | if (!ds) |
1960 | return -ENOMEM; | |
1961 | ||
1c02e7ba ZJS |
1962 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
1963 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
1964 | r = dns_transaction_request_dnssec_rr(t, ds); |
1965 | if (r < 0) | |
1966 | return r; | |
547973de | 1967 | |
105e1512 LP |
1968 | break; |
1969 | } | |
1970 | ||
105e1512 LP |
1971 | case DNS_TYPE_SOA: |
1972 | case DNS_TYPE_NS: { | |
1973 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1974 | ||
1975 | /* For an unsigned SOA or NS, try to acquire | |
1976 | * the matching DS RR, as we are at a zone cut | |
1977 | * then, and whether a DS exists tells us | |
1978 | * whether the zone is signed. Do so only if | |
1979 | * this RR matches our original question, | |
1980 | * however. */ | |
1981 | ||
1982 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1983 | if (r < 0) | |
1984 | return r; | |
1985 | if (r == 0) | |
1986 | continue; | |
1987 | ||
1988 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1989 | if (r < 0) | |
1990 | return r; | |
1991 | if (r > 0) | |
1992 | continue; | |
1993 | ||
1c02e7ba | 1994 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
1995 | if (!ds) |
1996 | return -ENOMEM; | |
1997 | ||
1c02e7ba ZJS |
1998 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
1999 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2000 | r = dns_transaction_request_dnssec_rr(t, ds); |
2001 | if (r < 0) | |
2002 | return r; | |
2003 | ||
2004 | break; | |
105e1512 LP |
2005 | } |
2006 | ||
b63fca62 | 2007 | case DNS_TYPE_DS: |
105e1512 LP |
2008 | case DNS_TYPE_CNAME: |
2009 | case DNS_TYPE_DNAME: { | |
2010 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2011 | const char *name; | |
2012 | ||
2013 | /* CNAMEs and DNAMEs cannot be located at a | |
2014 | * zone apex, hence ask for the parent SOA for | |
2015 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2016 | * apex. But do all that only if this is | |
2017 | * actually a response to our original | |
b63fca62 LP |
2018 | * question. |
2019 | * | |
2020 | * Similar for DS RRs, which are signed when | |
2021 | * the parent SOA is signed. */ | |
105e1512 LP |
2022 | |
2023 | r = dns_transaction_is_primary_response(t, rr); | |
2024 | if (r < 0) | |
2025 | return r; | |
2026 | if (r == 0) | |
2027 | continue; | |
2028 | ||
2029 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2030 | if (r < 0) | |
2031 | return r; | |
2032 | if (r > 0) | |
2033 | continue; | |
2034 | ||
43e6779a LP |
2035 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2036 | if (r < 0) | |
2037 | return r; | |
2038 | if (r > 0) | |
2039 | continue; | |
2040 | ||
1c02e7ba | 2041 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2042 | r = dns_name_parent(&name); |
2043 | if (r < 0) | |
2044 | return r; | |
2045 | if (r == 0) | |
2046 | continue; | |
2047 | ||
2048 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2049 | if (!soa) | |
2050 | return -ENOMEM; | |
2051 | ||
1c02e7ba ZJS |
2052 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2053 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2054 | r = dns_transaction_request_dnssec_rr(t, soa); |
2055 | if (r < 0) | |
2056 | return r; | |
2057 | ||
2058 | break; | |
2059 | } | |
2060 | ||
2061 | default: { | |
2062 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2063 | ||
b63fca62 LP |
2064 | /* For other unsigned RRsets (including |
2065 | * NSEC/NSEC3!), look for proof the zone is | |
2066 | * unsigned, by requesting the SOA RR of the | |
2067 | * zone. However, do so only if they are | |
2068 | * directly relevant to our original | |
105e1512 LP |
2069 | * question. */ |
2070 | ||
2071 | r = dns_transaction_is_primary_response(t, rr); | |
2072 | if (r < 0) | |
2073 | return r; | |
2074 | if (r == 0) | |
2075 | continue; | |
2076 | ||
2077 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2078 | if (r < 0) | |
2079 | return r; | |
2080 | if (r > 0) | |
2081 | continue; | |
2082 | ||
1c02e7ba | 2083 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2084 | if (!soa) |
2085 | return -ENOMEM; | |
2086 | ||
1c02e7ba ZJS |
2087 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2088 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2089 | r = dns_transaction_request_dnssec_rr(t, soa); |
2090 | if (r < 0) | |
2091 | return r; | |
2092 | break; | |
547973de LP |
2093 | }} |
2094 | } | |
2095 | ||
105e1512 LP |
2096 | /* Above, we requested everything necessary to validate what |
2097 | * we got. Now, let's request what we need to validate what we | |
2098 | * didn't get... */ | |
2099 | ||
2100 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2101 | if (r < 0) | |
2102 | return r; | |
2103 | if (r > 0) { | |
2104 | const char *name; | |
4bbc06cc | 2105 | uint16_t type = 0; |
105e1512 | 2106 | |
1c02e7ba | 2107 | name = dns_resource_key_name(t->key); |
105e1512 | 2108 | |
4bbc06cc LP |
2109 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2110 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2111 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2112 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2113 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2114 | * to see if that is signed. */ | |
105e1512 | 2115 | |
4bbc06cc | 2116 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2117 | r = dns_name_parent(&name); |
4bbc06cc LP |
2118 | if (r > 0) { |
2119 | type = DNS_TYPE_SOA; | |
2120 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2121 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2122 | } else |
105e1512 | 2123 | name = NULL; |
4bbc06cc LP |
2124 | |
2125 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2126 | ||
2127 | type = DNS_TYPE_DS; | |
2128 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2129 | t->id, dns_resource_key_name(t->key)); | |
2130 | ||
2131 | } else { | |
2132 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2133 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2134 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2135 | } |
105e1512 LP |
2136 | |
2137 | if (name) { | |
2138 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2139 | ||
4bbc06cc | 2140 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2141 | if (!soa) |
2142 | return -ENOMEM; | |
2143 | ||
2144 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2145 | if (r < 0) | |
2146 | return r; | |
2147 | } | |
2148 | } | |
2149 | ||
2150 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2151 | } |
2152 | ||
2153 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2154 | assert(t); |
547973de LP |
2155 | assert(source); |
2156 | ||
942eb2e7 LP |
2157 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2158 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2159 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2160 | |
942eb2e7 LP |
2161 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2162 | dns_transaction_process_dnssec(t); | |
547973de LP |
2163 | } |
2164 | ||
105e1512 LP |
2165 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2166 | DnsResourceRecord *rr; | |
2167 | int ifindex, r; | |
2168 | ||
2169 | assert(t); | |
2170 | ||
2171 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2172 | * RRs from the list of validated keys to the list of | |
2173 | * validated keys. */ | |
2174 | ||
2175 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2176 | ||
96bb7673 | 2177 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2178 | if (r < 0) |
2179 | return r; | |
2180 | if (r == 0) | |
2181 | continue; | |
2182 | ||
2183 | /* If so, the DNSKEY is validated too. */ | |
2184 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2185 | if (r < 0) | |
2186 | return r; | |
2187 | } | |
2188 | ||
2189 | return 0; | |
2190 | } | |
2191 | ||
2192 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2193 | int r; |
2194 | ||
2195 | assert(t); | |
2196 | assert(rr); | |
2197 | ||
105e1512 LP |
2198 | /* Checks if the RR we are looking for must be signed with an |
2199 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2200 | |
b652d4a2 | 2201 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2202 | return false; |
56352fe9 | 2203 | |
105e1512 LP |
2204 | if (dns_type_is_pseudo(rr->key->type)) |
2205 | return -EINVAL; | |
56352fe9 | 2206 | |
1c02e7ba | 2207 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2208 | if (r < 0) |
2209 | return r; | |
2210 | if (r > 0) | |
2211 | return false; | |
2212 | ||
105e1512 | 2213 | switch (rr->key->type) { |
56352fe9 | 2214 | |
105e1512 LP |
2215 | case DNS_TYPE_RRSIG: |
2216 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2217 | return false; | |
2218 | ||
2219 | case DNS_TYPE_SOA: | |
2220 | case DNS_TYPE_NS: { | |
2221 | DnsTransaction *dt; | |
2222 | Iterator i; | |
2223 | ||
b63fca62 | 2224 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2225 | |
2226 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2227 | ||
2228 | if (dt->key->class != rr->key->class) | |
2229 | continue; | |
2230 | if (dt->key->type != DNS_TYPE_DS) | |
2231 | continue; | |
2232 | ||
1c02e7ba | 2233 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2234 | if (r < 0) |
2235 | return r; | |
2236 | if (r == 0) | |
2237 | continue; | |
2238 | ||
2239 | /* We found a DS transactions for the SOA/NS | |
2240 | * RRs we are looking at. If it discovered signed DS | |
2241 | * RRs, then we need to be signed, too. */ | |
2242 | ||
097a2517 TA |
2243 | if (!dt->answer_authenticated) |
2244 | return false; | |
105e1512 | 2245 | |
097a2517 | 2246 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2247 | } |
2248 | ||
2249 | /* We found nothing that proves this is safe to leave | |
2250 | * this unauthenticated, hence ask inist on | |
2251 | * authentication. */ | |
2252 | return true; | |
2253 | } | |
2254 | ||
b63fca62 | 2255 | case DNS_TYPE_DS: |
105e1512 LP |
2256 | case DNS_TYPE_CNAME: |
2257 | case DNS_TYPE_DNAME: { | |
2258 | const char *parent = NULL; | |
2259 | DnsTransaction *dt; | |
2260 | Iterator i; | |
2261 | ||
b63fca62 LP |
2262 | /* |
2263 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2264 | * | |
2265 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2266 | */ | |
105e1512 LP |
2267 | |
2268 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2269 | ||
2270 | if (dt->key->class != rr->key->class) | |
2271 | continue; | |
2272 | if (dt->key->type != DNS_TYPE_SOA) | |
2273 | continue; | |
2274 | ||
2275 | if (!parent) { | |
1c02e7ba | 2276 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2277 | r = dns_name_parent(&parent); |
2278 | if (r < 0) | |
2279 | return r; | |
2280 | if (r == 0) { | |
b63fca62 LP |
2281 | if (rr->key->type == DNS_TYPE_DS) |
2282 | return true; | |
2283 | ||
105e1512 LP |
2284 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2285 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2286 | return -EBADMSG; | |
2287 | } | |
2288 | } | |
2289 | ||
1c02e7ba | 2290 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2291 | if (r < 0) |
2292 | return r; | |
2293 | if (r == 0) | |
2294 | continue; | |
2295 | ||
2296 | return t->answer_authenticated; | |
2297 | } | |
2298 | ||
2299 | return true; | |
2300 | } | |
2301 | ||
2302 | default: { | |
2303 | DnsTransaction *dt; | |
2304 | Iterator i; | |
2305 | ||
b63fca62 | 2306 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2307 | |
2308 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2309 | ||
2310 | if (dt->key->class != rr->key->class) | |
2311 | continue; | |
2312 | if (dt->key->type != DNS_TYPE_SOA) | |
2313 | continue; | |
2314 | ||
1c02e7ba | 2315 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2316 | if (r < 0) |
2317 | return r; | |
2318 | if (r == 0) | |
2319 | continue; | |
2320 | ||
2321 | /* We found the transaction that was supposed to find | |
2322 | * the SOA RR for us. It was successful, but found no | |
2323 | * RR for us. This means we are not at a zone cut. In | |
2324 | * this case, we require authentication if the SOA | |
2325 | * lookup was authenticated too. */ | |
2326 | return t->answer_authenticated; | |
2327 | } | |
2328 | ||
2329 | return true; | |
2330 | }} | |
56352fe9 LP |
2331 | } |
2332 | ||
d33b6cf3 LP |
2333 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2334 | DnsTransaction *dt; | |
2335 | const char *tld; | |
2336 | Iterator i; | |
2337 | int r; | |
2338 | ||
2339 | /* If DNSSEC downgrade mode is on, checks whether the | |
2340 | * specified RR is one level below a TLD we have proven not to | |
2341 | * exist. In such a case we assume that this is a private | |
2342 | * domain, and permit it. | |
2343 | * | |
2344 | * This detects cases like the Fritz!Box router networks. Each | |
2345 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2346 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2347 | * are served by the router itself, while requests for the | |
2348 | * "box" domain will result in NXDOMAIN. | |
2349 | * | |
2350 | * Note that this logic is unable to detect cases where a | |
2351 | * router serves a private DNS zone directly under | |
2352 | * non-existing TLD. In such a case we cannot detect whether | |
2353 | * the TLD is supposed to exist or not, as all requests we | |
2354 | * make for it will be answered by the router's zone, and not | |
2355 | * by the root zone. */ | |
2356 | ||
2357 | assert(t); | |
2358 | ||
2359 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2360 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2361 | ||
1c02e7ba | 2362 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2363 | r = dns_name_parent(&tld); |
2364 | if (r < 0) | |
2365 | return r; | |
2366 | if (r == 0) | |
2367 | return false; /* Already the root domain */ | |
2368 | ||
2369 | if (!dns_name_is_single_label(tld)) | |
2370 | return false; | |
2371 | ||
2372 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2373 | ||
2374 | if (dt->key->class != key->class) | |
2375 | continue; | |
2376 | ||
1c02e7ba | 2377 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2378 | if (r < 0) |
2379 | return r; | |
2380 | if (r == 0) | |
2381 | continue; | |
2382 | ||
2383 | /* We found an auxiliary lookup we did for the TLD. If | |
2384 | * that returned with NXDOMAIN, we know the TLD didn't | |
2385 | * exist, and hence this might be a private zone. */ | |
2386 | ||
2387 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2388 | } | |
2389 | ||
2390 | return false; | |
2391 | } | |
2392 | ||
105e1512 | 2393 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2394 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2395 | DnsTransaction *dt; |
2396 | const char *name; | |
4bbc06cc | 2397 | uint16_t type = 0; |
105e1512 LP |
2398 | Iterator i; |
2399 | int r; | |
56352fe9 LP |
2400 | |
2401 | assert(t); | |
2402 | ||
105e1512 LP |
2403 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2404 | * this negative reply */ | |
56352fe9 | 2405 | |
b652d4a2 | 2406 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2407 | return false; |
56352fe9 | 2408 | |
105e1512 LP |
2409 | if (dns_type_is_pseudo(t->key->type)) |
2410 | return -EINVAL; | |
2411 | ||
1c02e7ba | 2412 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2413 | if (r < 0) |
2414 | return r; | |
2415 | if (r > 0) | |
2416 | return false; | |
2417 | ||
d33b6cf3 LP |
2418 | r = dns_transaction_in_private_tld(t, t->key); |
2419 | if (r < 0) | |
2420 | return r; | |
2421 | if (r > 0) { | |
2422 | /* The lookup is from a TLD that is proven not to | |
2423 | * exist, and we are in downgrade mode, hence ignore | |
2424 | * that fact that we didn't get any NSEC RRs.*/ | |
2425 | ||
202b76ae ZJS |
2426 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2427 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2428 | return false; |
2429 | } | |
2430 | ||
1c02e7ba | 2431 | name = dns_resource_key_name(t->key); |
105e1512 | 2432 | |
4bbc06cc | 2433 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2434 | |
4bbc06cc LP |
2435 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2436 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2437 | |
2438 | r = dns_name_parent(&name); | |
56352fe9 LP |
2439 | if (r < 0) |
2440 | return r; | |
2441 | if (r == 0) | |
105e1512 | 2442 | return true; |
4bbc06cc LP |
2443 | |
2444 | type = DNS_TYPE_SOA; | |
2445 | ||
2446 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2447 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2448 | type = DNS_TYPE_DS; | |
2449 | else | |
2450 | /* For all other negative replies, check for the SOA lookup */ | |
2451 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2452 | |
2453 | /* For all other RRs we check the SOA on the same level to see | |
2454 | * if it's signed. */ | |
2455 | ||
2456 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2457 | ||
2458 | if (dt->key->class != t->key->class) | |
2459 | continue; | |
4bbc06cc | 2460 | if (dt->key->type != type) |
56352fe9 LP |
2461 | continue; |
2462 | ||
1c02e7ba | 2463 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2464 | if (r < 0) |
2465 | return r; | |
105e1512 LP |
2466 | if (r == 0) |
2467 | continue; | |
2468 | ||
2469 | return dt->answer_authenticated; | |
56352fe9 LP |
2470 | } |
2471 | ||
105e1512 LP |
2472 | /* If in doubt, require NSEC/NSEC3 */ |
2473 | return true; | |
56352fe9 LP |
2474 | } |
2475 | ||
94aa7071 LP |
2476 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2477 | DnsResourceRecord *rrsig; | |
2478 | bool found = false; | |
2479 | int r; | |
2480 | ||
2481 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2482 | * the specified RRset is authenticated (i.e. has a matching | |
2483 | * DS RR). */ | |
2484 | ||
1c02e7ba | 2485 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2486 | if (r < 0) |
2487 | return r; | |
2488 | if (r > 0) | |
2489 | return false; | |
2490 | ||
94aa7071 LP |
2491 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2492 | DnsTransaction *dt; | |
2493 | Iterator i; | |
2494 | ||
2495 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2496 | if (r < 0) | |
2497 | return r; | |
2498 | if (r == 0) | |
2499 | continue; | |
2500 | ||
2501 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2502 | ||
2503 | if (dt->key->class != rr->key->class) | |
2504 | continue; | |
2505 | ||
2506 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2507 | ||
1c02e7ba | 2508 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2509 | if (r < 0) |
2510 | return r; | |
2511 | if (r == 0) | |
2512 | continue; | |
2513 | ||
2514 | /* OK, we found an auxiliary DNSKEY | |
2515 | * lookup. If that lookup is | |
2516 | * authenticated, report this. */ | |
2517 | ||
2518 | if (dt->answer_authenticated) | |
2519 | return true; | |
2520 | ||
2521 | found = true; | |
2522 | ||
2523 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2524 | ||
1c02e7ba | 2525 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2526 | if (r < 0) |
2527 | return r; | |
2528 | if (r == 0) | |
2529 | continue; | |
2530 | ||
2531 | /* OK, we found an auxiliary DS | |
2532 | * lookup. If that lookup is | |
2533 | * authenticated and non-zero, we | |
2534 | * won! */ | |
2535 | ||
2536 | if (!dt->answer_authenticated) | |
2537 | return false; | |
2538 | ||
2539 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2540 | } | |
2541 | } | |
2542 | } | |
2543 | ||
2544 | return found ? false : -ENXIO; | |
2545 | } | |
2546 | ||
b652d4a2 LP |
2547 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2548 | assert(t); | |
2549 | assert(rr); | |
2550 | ||
2551 | /* We know that the root domain is signed, hence if it appears | |
2552 | * not to be signed, there's a problem with the DNS server */ | |
2553 | ||
2554 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2555 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2556 | } |
2557 | ||
0f87f3e8 LP |
2558 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2559 | DnsResourceRecord *rr; | |
2560 | int r; | |
2561 | ||
2562 | assert(t); | |
2563 | ||
2564 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2565 | * for a key from our trust anchor. Note that we don't care | |
2566 | * whether the DNSKEY can be authenticated or not. It's | |
2567 | * sufficient if it is self-signed. */ | |
2568 | ||
2569 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2570 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2571 | if (r < 0) |
2572 | return r; | |
2573 | } | |
2574 | ||
2575 | return 0; | |
2576 | } | |
2577 | ||
c9c72065 LP |
2578 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2579 | bool changed; | |
2580 | int r; | |
2581 | ||
2582 | assert(t); | |
2583 | ||
2584 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2585 | * our trust anchors database considers revoked. */ | |
2586 | ||
2587 | do { | |
2588 | DnsResourceRecord *rr; | |
2589 | ||
2590 | changed = false; | |
2591 | ||
2592 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2593 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2594 | if (r < 0) | |
2595 | return r; | |
2596 | if (r > 0) { | |
2597 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2598 | if (r < 0) | |
2599 | return r; | |
2600 | ||
2601 | assert(r > 0); | |
2602 | changed = true; | |
2603 | break; | |
2604 | } | |
2605 | } | |
2606 | } while (changed); | |
2607 | ||
2608 | return 0; | |
2609 | } | |
2610 | ||
942eb2e7 LP |
2611 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2612 | DnsTransaction *dt; | |
2613 | Iterator i; | |
2614 | int r; | |
2615 | ||
2616 | assert(t); | |
2617 | ||
2618 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2619 | ||
2620 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2621 | ||
2622 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2623 | continue; | |
2624 | ||
2625 | if (!dt->answer_authenticated) | |
2626 | continue; | |
2627 | ||
2628 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2629 | if (r < 0) | |
2630 | return r; | |
2631 | } | |
2632 | ||
2633 | return 0; | |
2634 | } | |
2635 | ||
c690b20a ZJS |
2636 | typedef enum { |
2637 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2638 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2639 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2640 | } Phase; | |
2641 | ||
2642 | static int dnssec_validate_records( | |
2643 | DnsTransaction *t, | |
2644 | Phase phase, | |
2645 | bool *have_nsec, | |
2646 | DnsAnswer **validated) { | |
2647 | ||
547973de | 2648 | DnsResourceRecord *rr; |
56352fe9 | 2649 | int r; |
547973de | 2650 | |
c690b20a | 2651 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2652 | |
c690b20a ZJS |
2653 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2654 | DnsResourceRecord *rrsig = NULL; | |
2655 | DnssecResult result; | |
547973de | 2656 | |
c690b20a ZJS |
2657 | switch (rr->key->type) { |
2658 | case DNS_TYPE_RRSIG: | |
2659 | continue; | |
547973de | 2660 | |
c690b20a ZJS |
2661 | case DNS_TYPE_DNSKEY: |
2662 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2663 | if (phase == DNSSEC_PHASE_NSEC) | |
2664 | continue; | |
2665 | break; | |
547973de | 2666 | |
c690b20a ZJS |
2667 | case DNS_TYPE_NSEC: |
2668 | case DNS_TYPE_NSEC3: | |
2669 | *have_nsec = true; | |
547973de | 2670 | |
c690b20a ZJS |
2671 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2672 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2673 | continue; | |
2674 | break; | |
105e1512 | 2675 | |
c690b20a ZJS |
2676 | default: |
2677 | /* We validate all other RRs only in the ALL phases */ | |
2678 | if (phase != DNSSEC_PHASE_ALL) | |
2679 | continue; | |
2680 | } | |
b652d4a2 | 2681 | |
c690b20a ZJS |
2682 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2683 | if (r < 0) | |
2684 | return r; | |
547973de | 2685 | |
c690b20a | 2686 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2687 | |
c690b20a | 2688 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2689 | |
c690b20a ZJS |
2690 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2691 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2692 | * the set of validated keys for this transaction. */ | |
547973de | 2693 | |
c690b20a ZJS |
2694 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2695 | if (r < 0) | |
2696 | return r; | |
c9c72065 | 2697 | |
c690b20a ZJS |
2698 | /* Some of the DNSKEYs we just added might already have been revoked, |
2699 | * remove them again in that case. */ | |
2700 | r = dns_transaction_invalidate_revoked_keys(t); | |
2701 | if (r < 0) | |
2702 | return r; | |
2703 | } | |
547973de | 2704 | |
c690b20a ZJS |
2705 | /* Add the validated RRset to the new list of validated |
2706 | * RRsets, and remove it from the unvalidated RRsets. | |
2707 | * We mark the RRset as authenticated and cacheable. */ | |
2708 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2709 | if (r < 0) | |
2710 | return r; | |
547973de | 2711 | |
c690b20a | 2712 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2713 | |
c690b20a ZJS |
2714 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2715 | return 1; | |
2716 | } | |
547973de | 2717 | |
c690b20a ZJS |
2718 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2719 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2720 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2721 | if (phase != DNSSEC_PHASE_ALL) | |
2722 | continue; | |
0c7bff0a | 2723 | |
c690b20a ZJS |
2724 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2725 | bool authenticated = false; | |
2726 | const char *source; | |
0c7bff0a | 2727 | |
c690b20a ZJS |
2728 | /* This RRset validated, but as a wildcard. This means we need |
2729 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists.*/ | |
0c7bff0a | 2730 | |
c690b20a ZJS |
2731 | /* First step, determine the source of synthesis */ |
2732 | r = dns_resource_record_source(rrsig, &source); | |
2733 | if (r < 0) | |
2734 | return r; | |
0c7bff0a | 2735 | |
c690b20a | 2736 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2737 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2738 | source, |
2739 | rrsig->rrsig.signer, | |
2740 | &authenticated); | |
0c7bff0a | 2741 | |
c690b20a ZJS |
2742 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2743 | if (r == 0) | |
2744 | result = DNSSEC_INVALID; | |
2745 | else { | |
2746 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2747 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2748 | if (r < 0) | |
2749 | return r; | |
2750 | ||
2751 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2752 | ||
2753 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2754 | return 1; | |
0c7bff0a | 2755 | } |
c690b20a | 2756 | } |
0c7bff0a | 2757 | |
c690b20a ZJS |
2758 | if (result == DNSSEC_NO_SIGNATURE) { |
2759 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2760 | if (r < 0) |
2761 | return r; | |
c690b20a ZJS |
2762 | if (r == 0) { |
2763 | /* Data does not require signing. In that case, just copy it over, | |
2764 | * but remember that this is by no means authenticated.*/ | |
2765 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); | |
2766 | if (r < 0) | |
2767 | return r; | |
2768 | ||
2769 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2770 | return 1; | |
2771 | } | |
547973de | 2772 | |
c690b20a ZJS |
2773 | r = dns_transaction_known_signed(t, rr); |
2774 | if (r < 0) | |
2775 | return r; | |
2776 | if (r > 0) { | |
2777 | /* This is an RR we know has to be signed. If it isn't this means | |
2778 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2779 | |
c690b20a | 2780 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2781 | |
c690b20a | 2782 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2783 | |
c690b20a | 2784 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2785 | |
c690b20a | 2786 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2787 | if (r < 0) |
2788 | return r; | |
547973de | 2789 | |
c690b20a ZJS |
2790 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2791 | return 1; | |
2792 | } | |
a150ff5e | 2793 | |
c690b20a ZJS |
2794 | /* Otherwise, fail */ |
2795 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2796 | return 0; | |
f3cf586d | 2797 | } |
547973de | 2798 | |
c690b20a ZJS |
2799 | r = dns_transaction_in_private_tld(t, rr->key); |
2800 | if (r < 0) | |
2801 | return r; | |
2802 | if (r > 0) { | |
202b76ae | 2803 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2804 | |
c690b20a ZJS |
2805 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2806 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2807 | |
202b76ae ZJS |
2808 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2809 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2810 | |
c690b20a | 2811 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2812 | if (r < 0) |
2813 | return r; | |
0c7bff0a | 2814 | |
c690b20a ZJS |
2815 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2816 | return 1; | |
2817 | } | |
2818 | } | |
0c7bff0a | 2819 | |
c690b20a ZJS |
2820 | if (IN_SET(result, |
2821 | DNSSEC_MISSING_KEY, | |
2822 | DNSSEC_SIGNATURE_EXPIRED, | |
2823 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2824 | |
c690b20a ZJS |
2825 | r = dns_transaction_dnskey_authenticated(t, rr); |
2826 | if (r < 0 && r != -ENXIO) | |
2827 | return r; | |
2828 | if (r == 0) { | |
2829 | /* The DNSKEY transaction was not authenticated, this means there's | |
2830 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2831 | |
c690b20a | 2832 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2833 | if (r < 0) |
2834 | return r; | |
b652d4a2 | 2835 | |
c690b20a ZJS |
2836 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2837 | return 1; | |
2838 | } | |
2839 | } | |
b652d4a2 | 2840 | |
c690b20a ZJS |
2841 | r = dns_transaction_is_primary_response(t, rr); |
2842 | if (r < 0) | |
2843 | return r; | |
2844 | if (r > 0) { | |
2845 | /* Look for a matching DNAME for this CNAME */ | |
2846 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2847 | if (r < 0) | |
2848 | return r; | |
2849 | if (r == 0) { | |
2850 | /* Also look among the stuff we already validated */ | |
2851 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2852 | if (r < 0) |
2853 | return r; | |
c690b20a | 2854 | } |
d33b6cf3 | 2855 | |
c690b20a ZJS |
2856 | if (r == 0) { |
2857 | if (IN_SET(result, | |
2858 | DNSSEC_INVALID, | |
2859 | DNSSEC_SIGNATURE_EXPIRED, | |
2860 | DNSSEC_NO_SIGNATURE)) | |
2861 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
2862 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2863 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
2864 | ||
2865 | /* This is a primary response to our question, and it failed validation. | |
2866 | * That's fatal. */ | |
2867 | t->answer_dnssec_result = result; | |
2868 | return 0; | |
2869 | } | |
d33b6cf3 | 2870 | |
c690b20a ZJS |
2871 | /* This is a primary response, but we do have a DNAME RR |
2872 | * in the RR that can replay this CNAME, hence rely on | |
2873 | * that, and we can remove the CNAME in favour of it. */ | |
2874 | } | |
d33b6cf3 | 2875 | |
c690b20a ZJS |
2876 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
2877 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2878 | if (r < 0) | |
2879 | return r; | |
d33b6cf3 | 2880 | |
c690b20a ZJS |
2881 | /* We dropped something from the answer, start from the beginning. */ |
2882 | return 1; | |
2883 | } | |
f3cf586d | 2884 | |
c690b20a ZJS |
2885 | return 2; /* Finito. */ |
2886 | } | |
94aa7071 | 2887 | |
c690b20a ZJS |
2888 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2889 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
2890 | Phase phase; | |
2891 | DnsAnswerFlags flags; | |
2892 | int r; | |
202b76ae | 2893 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 2894 | |
c690b20a | 2895 | assert(t); |
94aa7071 | 2896 | |
c690b20a ZJS |
2897 | /* We have now collected all DS and DNSKEY RRs in |
2898 | * t->validated_keys, let's see which RRs we can now | |
2899 | * authenticate with that. */ | |
94aa7071 | 2900 | |
c690b20a ZJS |
2901 | if (t->scope->dnssec_mode == DNSSEC_NO) |
2902 | return 0; | |
a150ff5e | 2903 | |
c690b20a ZJS |
2904 | /* Already validated */ |
2905 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
2906 | return 0; | |
105e1512 | 2907 | |
c690b20a ZJS |
2908 | /* Our own stuff needs no validation */ |
2909 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
2910 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
2911 | t->answer_authenticated = true; | |
2912 | return 0; | |
2913 | } | |
a150ff5e | 2914 | |
c690b20a ZJS |
2915 | /* Cached stuff is not affected by validation. */ |
2916 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2917 | return 0; | |
f3cf586d | 2918 | |
c690b20a ZJS |
2919 | if (!dns_transaction_dnssec_supported_full(t)) { |
2920 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2921 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 2922 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
2923 | return 0; |
2924 | } | |
f3cf586d | 2925 | |
202b76ae ZJS |
2926 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
2927 | t->id, | |
2928 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 2929 | |
c690b20a ZJS |
2930 | /* First, see if this response contains any revoked trust |
2931 | * anchors we care about */ | |
2932 | r = dns_transaction_check_revoked_trust_anchors(t); | |
2933 | if (r < 0) | |
2934 | return r; | |
43e6779a | 2935 | |
c690b20a ZJS |
2936 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
2937 | r = dns_transaction_copy_validated(t); | |
2938 | if (r < 0) | |
2939 | return r; | |
43e6779a | 2940 | |
c690b20a ZJS |
2941 | /* Second, see if there are DNSKEYs we already know a |
2942 | * validated DS for. */ | |
2943 | r = dns_transaction_validate_dnskey_by_ds(t); | |
2944 | if (r < 0) | |
2945 | return r; | |
43e6779a | 2946 | |
c690b20a ZJS |
2947 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
2948 | * anchor says are revoked. After all we might have marked | |
2949 | * some keys revoked above, but they might still be lingering | |
2950 | * in our validated_keys list. */ | |
2951 | r = dns_transaction_invalidate_revoked_keys(t); | |
2952 | if (r < 0) | |
2953 | return r; | |
f3cf586d | 2954 | |
c690b20a ZJS |
2955 | phase = DNSSEC_PHASE_DNSKEY; |
2956 | for (;;) { | |
2957 | bool have_nsec = false; | |
f3cf586d | 2958 | |
c690b20a ZJS |
2959 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
2960 | if (r <= 0) | |
2961 | return r; | |
547973de | 2962 | |
c690b20a ZJS |
2963 | /* Try again as long as we managed to achieve something */ |
2964 | if (r == 1) | |
547973de LP |
2965 | continue; |
2966 | ||
c690b20a | 2967 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 2968 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 2969 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
2970 | continue; |
2971 | } | |
2972 | ||
c690b20a ZJS |
2973 | if (phase != DNSSEC_PHASE_ALL) { |
2974 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
2975 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
2976 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 2977 | continue; |
547973de LP |
2978 | } |
2979 | ||
56352fe9 | 2980 | /* We're done */ |
547973de LP |
2981 | break; |
2982 | } | |
2983 | ||
2984 | dns_answer_unref(t->answer); | |
2985 | t->answer = validated; | |
2986 | validated = NULL; | |
2987 | ||
72667f08 LP |
2988 | /* At this point the answer only contains validated |
2989 | * RRsets. Now, let's see if it actually answers the question | |
2990 | * we asked. If so, great! If it doesn't, then see if | |
2991 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2992 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2993 | if (r > 0) { |
105e1512 LP |
2994 | /* Yes, it answers the question! */ |
2995 | ||
2996 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2997 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2998 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2999 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3000 | t->answer_authenticated = true; | |
3001 | } else { | |
3002 | /* The answer is not fully authenticated. */ | |
019036a4 | 3003 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3004 | t->answer_authenticated = false; |
3005 | } | |
3006 | ||
72667f08 LP |
3007 | } else if (r == 0) { |
3008 | DnssecNsecResult nr; | |
ed29bfdc | 3009 | bool authenticated = false; |
72667f08 LP |
3010 | |
3011 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3012 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3013 | if (r < 0) |
3014 | return r; | |
3015 | ||
3016 | switch (nr) { | |
3017 | ||
3018 | case DNSSEC_NSEC_NXDOMAIN: | |
3019 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3020 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3021 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3022 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3023 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3024 | |
59c5b597 | 3025 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3026 | break; |
3027 | ||
3028 | case DNSSEC_NSEC_NODATA: | |
3029 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3030 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3031 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3032 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3033 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3034 | |
59c5b597 | 3035 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3036 | break; |
3037 | ||
105e1512 LP |
3038 | case DNSSEC_NSEC_OPTOUT: |
3039 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3040 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3041 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3042 | t->answer_authenticated = false; |
7aa8ce98 | 3043 | |
59c5b597 | 3044 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3045 | break; |
3046 | ||
72667f08 LP |
3047 | case DNSSEC_NSEC_NO_RR: |
3048 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3049 | |
3050 | r = dns_transaction_requires_nsec(t); | |
3051 | if (r < 0) | |
3052 | return r; | |
7aa8ce98 | 3053 | if (r > 0) { |
019036a4 | 3054 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3055 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3056 | } else { |
019036a4 | 3057 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3058 | t->answer_authenticated = false; |
59c5b597 | 3059 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3060 | } |
3061 | ||
3062 | break; | |
3063 | ||
3064 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3065 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3066 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3067 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3068 | break; |
3069 | ||
3070 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3071 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3072 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3073 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3074 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3075 | break; |
3076 | ||
3077 | default: | |
3078 | assert_not_reached("Unexpected NSEC result."); | |
3079 | } | |
3080 | } | |
3081 | ||
547973de LP |
3082 | return 1; |
3083 | } | |
3084 | ||
ec2c5e43 LP |
3085 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3086 | [DNS_TRANSACTION_NULL] = "null", | |
3087 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3088 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3089 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3090 | [DNS_TRANSACTION_SUCCESS] = "success", |
3091 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3092 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3093 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3094 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3095 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3096 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3097 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3098 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3099 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3100 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3101 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3102 | }; |
3103 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3104 | |
3105 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3106 | [DNS_TRANSACTION_NETWORK] = "network", | |
3107 | [DNS_TRANSACTION_CACHE] = "cache", | |
3108 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3109 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3110 | }; |
3111 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |