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ec2c5e43 LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
beef6a5f LP |
22 | #include <sd-messages.h> |
23 | ||
ec2c5e43 | 24 | #include "af-list.h" |
b5efdb8a | 25 | #include "alloc-util.h" |
f52e61da | 26 | #include "dns-domain.h" |
3ffd4af2 LP |
27 | #include "fd-util.h" |
28 | #include "random-util.h" | |
7778dfff | 29 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
30 | #include "resolved-dns-transaction.h" |
31 | #include "resolved-llmnr.h" | |
8b43440b | 32 | #include "string-table.h" |
ec2c5e43 | 33 | |
c61d2b44 LP |
34 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
35 | assert(t); | |
36 | ||
37 | t->received = dns_packet_unref(t->received); | |
38 | t->answer = dns_answer_unref(t->answer); | |
39 | t->answer_rcode = 0; | |
40 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
41 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
42 | t->answer_authenticated = false; | |
d3760be0 | 43 | t->answer_nsec_ttl = (uint32_t) -1; |
c61d2b44 LP |
44 | } |
45 | ||
c5b4f861 LP |
46 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
47 | DnsTransaction *z; | |
48 | ||
49 | assert(t); | |
50 | ||
51 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
52 | set_remove(z->notify_transactions, t); | |
53 | dns_transaction_gc(z); | |
54 | } | |
55 | } | |
56 | ||
f32f0e57 LP |
57 | static void dns_transaction_close_connection(DnsTransaction *t) { |
58 | assert(t); | |
59 | ||
60 | t->stream = dns_stream_free(t->stream); | |
61 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); | |
62 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
63 | } | |
64 | ||
f535705a | 65 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
66 | assert(t); |
67 | ||
68 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
69 | } |
70 | ||
ec2c5e43 | 71 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 72 | DnsQueryCandidate *c; |
ec2c5e43 | 73 | DnsZoneItem *i; |
547973de | 74 | DnsTransaction *z; |
ec2c5e43 LP |
75 | |
76 | if (!t) | |
77 | return NULL; | |
78 | ||
51e399bc LP |
79 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
80 | ||
f32f0e57 | 81 | dns_transaction_close_connection(t); |
f535705a | 82 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 83 | |
ec2c5e43 | 84 | dns_packet_unref(t->sent); |
c61d2b44 | 85 | dns_transaction_reset_answer(t); |
ec2c5e43 | 86 | |
8300ba21 | 87 | dns_server_unref(t->server); |
ec2c5e43 LP |
88 | |
89 | if (t->scope) { | |
f9ebb22a LP |
90 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
91 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
92 | |
93 | if (t->id != 0) | |
94 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
95 | } | |
96 | ||
547973de | 97 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 98 | set_remove(c->transactions, t); |
547973de | 99 | set_free(t->notify_query_candidates); |
801ad6a6 | 100 | |
547973de | 101 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 102 | i->probe_transaction = NULL; |
547973de LP |
103 | set_free(t->notify_zone_items); |
104 | ||
105 | while ((z = set_steal_first(t->notify_transactions))) | |
106 | set_remove(z->dnssec_transactions, t); | |
107 | set_free(t->notify_transactions); | |
108 | ||
c5b4f861 | 109 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
110 | set_free(t->dnssec_transactions); |
111 | ||
112 | dns_answer_unref(t->validated_keys); | |
97cc656c | 113 | dns_resource_key_unref(t->key); |
a5784c49 | 114 | free(t->key_string); |
97cc656c | 115 | |
ec2c5e43 LP |
116 | free(t); |
117 | return NULL; | |
118 | } | |
119 | ||
120 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
121 | ||
51e399bc | 122 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
123 | assert(t); |
124 | ||
125 | if (t->block_gc > 0) | |
51e399bc | 126 | return true; |
ec2c5e43 | 127 | |
547973de LP |
128 | if (set_isempty(t->notify_query_candidates) && |
129 | set_isempty(t->notify_zone_items) && | |
51e399bc | 130 | set_isempty(t->notify_transactions)) { |
ec2c5e43 | 131 | dns_transaction_free(t); |
51e399bc LP |
132 | return false; |
133 | } | |
134 | ||
135 | return true; | |
ec2c5e43 LP |
136 | } |
137 | ||
f52e61da | 138 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
139 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
140 | int r; | |
141 | ||
142 | assert(ret); | |
143 | assert(s); | |
f52e61da | 144 | assert(key); |
ec2c5e43 | 145 | |
9eae2bf3 | 146 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 147 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 148 | return -EINVAL; |
d0129ddb LP |
149 | if (dns_type_is_obsolete(key->type)) |
150 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
151 | |
152 | /* We only support the IN class */ | |
c463eb78 | 153 | if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) |
9eae2bf3 LP |
154 | return -EOPNOTSUPP; |
155 | ||
d5099efc | 156 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
157 | if (r < 0) |
158 | return r; | |
159 | ||
f9ebb22a | 160 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
161 | if (r < 0) |
162 | return r; | |
163 | ||
ec2c5e43 LP |
164 | t = new0(DnsTransaction, 1); |
165 | if (!t) | |
166 | return -ENOMEM; | |
167 | ||
4667e00a | 168 | t->dns_udp_fd = -1; |
c3bc53e6 | 169 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 170 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 171 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 172 | t->key = dns_resource_key_ref(key); |
274b8748 | 173 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 174 | |
da0c630e | 175 | /* Find a fresh, unused transaction id */ |
ec2c5e43 LP |
176 | do |
177 | random_bytes(&t->id, sizeof(t->id)); | |
178 | while (t->id == 0 || | |
179 | hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); | |
180 | ||
181 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
182 | if (r < 0) { | |
183 | t->id = 0; | |
184 | return r; | |
185 | } | |
186 | ||
f9ebb22a | 187 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
188 | if (r < 0) { |
189 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
190 | return r; | |
191 | } | |
192 | ||
f9ebb22a | 193 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
194 | t->scope = s; |
195 | ||
a150ff5e LP |
196 | s->manager->n_transactions_total ++; |
197 | ||
ec2c5e43 LP |
198 | if (ret) |
199 | *ret = t; | |
200 | ||
201 | t = NULL; | |
202 | ||
203 | return 0; | |
204 | } | |
205 | ||
ec2c5e43 | 206 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 207 | _cleanup_free_ char *pretty = NULL; |
ec2c5e43 | 208 | DnsZoneItem *z; |
ec2c5e43 LP |
209 | |
210 | assert(t); | |
211 | assert(p); | |
212 | ||
213 | if (manager_our_packet(t->scope->manager, p) != 0) | |
214 | return; | |
215 | ||
2fb3034c LP |
216 | in_addr_to_string(p->family, &p->sender, &pretty); |
217 | ||
a5784c49 LP |
218 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
219 | t->id, | |
220 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
221 | dns_protocol_to_string(t->scope->protocol), |
222 | t->scope->link ? t->scope->link->name : "*", | |
2fb3034c LP |
223 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), |
224 | pretty); | |
ec2c5e43 | 225 | |
a4076574 LP |
226 | /* RFC 4795, Section 4.1 says that the peer with the |
227 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
228 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
229 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
230 | return; |
231 | } | |
232 | ||
4d91eec4 | 233 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 234 | |
ec2c5e43 | 235 | t->block_gc++; |
547973de | 236 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
237 | /* First, make sure the zone item drops the reference |
238 | * to us */ | |
239 | dns_zone_item_probe_stop(z); | |
240 | ||
241 | /* Secondly, report this as conflict, so that we might | |
242 | * look for a different hostname */ | |
ec2c5e43 | 243 | dns_zone_item_conflict(z); |
3ef64445 | 244 | } |
ec2c5e43 LP |
245 | t->block_gc--; |
246 | ||
247 | dns_transaction_gc(t); | |
248 | } | |
249 | ||
250 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 251 | DnsQueryCandidate *c; |
ec2c5e43 | 252 | DnsZoneItem *z; |
547973de | 253 | DnsTransaction *d; |
ec2c5e43 LP |
254 | Iterator i; |
255 | ||
256 | assert(t); | |
547973de | 257 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 258 | |
f61dfddb LP |
259 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) |
260 | log_struct(LOG_NOTICE, | |
beef6a5f | 261 | LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), |
f61dfddb LP |
262 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", dns_transaction_key_string(t), dnssec_result_to_string(t->answer_dnssec_result)), |
263 | "DNS_TRANSACTION=%" PRIu16, t->id, | |
264 | "DNS_QUESTION=%s", dns_transaction_key_string(t), | |
265 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), | |
266 | NULL); | |
267 | ||
ec2c5e43 LP |
268 | /* Note that this call might invalidate the query. Callers |
269 | * should hence not attempt to access the query or transaction | |
270 | * after calling this function. */ | |
271 | ||
a5784c49 LP |
272 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
273 | t->id, | |
274 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
275 | dns_protocol_to_string(t->scope->protocol), |
276 | t->scope->link ? t->scope->link->name : "*", | |
277 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), | |
c3bc53e6 | 278 | dns_transaction_state_to_string(state), |
a5784c49 LP |
279 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
280 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
281 | |
282 | t->state = state; | |
283 | ||
f32f0e57 | 284 | dns_transaction_close_connection(t); |
f535705a | 285 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
286 | |
287 | /* Notify all queries that are interested, but make sure the | |
288 | * transaction isn't freed while we are still looking at it */ | |
289 | t->block_gc++; | |
f7014757 | 290 | |
547973de LP |
291 | SET_FOREACH(c, t->notify_query_candidates, i) |
292 | dns_query_candidate_notify(c); | |
293 | SET_FOREACH(z, t->notify_zone_items, i) | |
294 | dns_zone_item_notify(z); | |
ec2c5e43 | 295 | |
f7014757 LP |
296 | if (!set_isempty(t->notify_transactions)) { |
297 | DnsTransaction **nt; | |
298 | unsigned j, n = 0; | |
299 | ||
300 | /* We need to be careful when notifying other | |
301 | * transactions, as that might destroy other | |
302 | * transactions in our list. Hence, in order to be | |
303 | * able to safely iterate through the list of | |
304 | * transactions, take a GC lock on all of them | |
305 | * first. Then, in a second loop, notify them, but | |
306 | * first unlock that specific transaction. */ | |
307 | ||
308 | nt = newa(DnsTransaction*, set_size(t->notify_transactions)); | |
309 | SET_FOREACH(d, t->notify_transactions, i) { | |
310 | nt[n++] = d; | |
311 | d->block_gc++; | |
312 | } | |
313 | ||
314 | assert(n == set_size(t->notify_transactions)); | |
315 | ||
316 | for (j = 0; j < n; j++) { | |
317 | if (set_contains(t->notify_transactions, nt[j])) | |
318 | dns_transaction_notify(nt[j], t); | |
319 | ||
320 | nt[j]->block_gc--; | |
321 | dns_transaction_gc(nt[j]); | |
322 | } | |
323 | } | |
324 | ||
325 | t->block_gc--; | |
ec2c5e43 LP |
326 | dns_transaction_gc(t); |
327 | } | |
328 | ||
519ef046 LP |
329 | static int dns_transaction_pick_server(DnsTransaction *t) { |
330 | DnsServer *server; | |
331 | ||
332 | assert(t); | |
333 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
334 | ||
335 | server = dns_scope_get_dns_server(t->scope); | |
336 | if (!server) | |
337 | return -ESRCH; | |
338 | ||
274b8748 | 339 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 LP |
340 | |
341 | if (server == t->server) | |
342 | return 0; | |
343 | ||
344 | dns_server_unref(t->server); | |
345 | t->server = dns_server_ref(server); | |
346 | ||
347 | return 1; | |
348 | } | |
349 | ||
8d10d620 LP |
350 | static void dns_transaction_retry(DnsTransaction *t) { |
351 | int r; | |
352 | ||
353 | assert(t); | |
354 | ||
355 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
356 | ||
357 | /* Before we try again, switch to a new server. */ | |
358 | dns_scope_next_dns_server(t->scope); | |
359 | ||
360 | r = dns_transaction_go(t); | |
361 | if (r < 0) | |
362 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
363 | } | |
364 | ||
c02cf2f4 LP |
365 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
366 | assert(t); | |
367 | ||
368 | if (!t->server) | |
369 | return 0; | |
370 | ||
371 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
372 | return 0; | |
373 | ||
374 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
375 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
376 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
377 | OPT RR or DO bit. One of these cases is documented here, for example: | |
378 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
379 | ||
380 | log_debug("Server feature level is now lower than when we began our transaction. Restarting."); | |
381 | return dns_transaction_go(t); | |
382 | } | |
383 | ||
ec2c5e43 LP |
384 | static int on_stream_complete(DnsStream *s, int error) { |
385 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
386 | DnsTransaction *t; | |
387 | ||
388 | assert(s); | |
389 | assert(s->transaction); | |
390 | ||
391 | /* Copy the data we care about out of the stream before we | |
392 | * destroy it. */ | |
393 | t = s->transaction; | |
394 | p = dns_packet_ref(s->read_packet); | |
395 | ||
396 | t->stream = dns_stream_free(t->stream); | |
397 | ||
a1a3f73a LP |
398 | if (ERRNO_IS_DISCONNECT(error)) { |
399 | usec_t usec; | |
400 | ||
92ec902a | 401 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 402 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 403 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a LP |
404 | |
405 | dns_transaction_retry(t); | |
ac720200 LP |
406 | return 0; |
407 | } | |
ec2c5e43 LP |
408 | if (error != 0) { |
409 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
410 | return 0; | |
411 | } | |
412 | ||
a4076574 | 413 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 414 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
415 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
416 | return 0; | |
417 | } | |
418 | ||
419 | dns_scope_check_conflicts(t->scope, p); | |
420 | ||
ec2c5e43 LP |
421 | t->block_gc++; |
422 | dns_transaction_process_reply(t, p); | |
423 | t->block_gc--; | |
424 | ||
519ef046 LP |
425 | /* If the response wasn't useful, then complete the transition |
426 | * now. After all, we are the worst feature set now with TCP | |
427 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
428 | if (t->state == DNS_TRANSACTION_PENDING) |
429 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
430 | else |
431 | dns_transaction_gc(t); | |
ec2c5e43 LP |
432 | |
433 | return 0; | |
434 | } | |
435 | ||
436 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
437 | _cleanup_close_ int fd = -1; | |
438 | int r; | |
439 | ||
440 | assert(t); | |
441 | ||
519ef046 | 442 | dns_transaction_close_connection(t); |
ec2c5e43 | 443 | |
106784eb | 444 | switch (t->scope->protocol) { |
519ef046 | 445 | |
106784eb | 446 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
447 | r = dns_transaction_pick_server(t); |
448 | if (r < 0) | |
449 | return r; | |
450 | ||
92ec902a | 451 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
452 | return -EOPNOTSUPP; |
453 | ||
274b8748 | 454 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
455 | if (r < 0) |
456 | return r; | |
457 | ||
458 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 459 | break; |
ec2c5e43 | 460 | |
106784eb | 461 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 462 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 463 | if (t->received) |
519ef046 | 464 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
465 | else { |
466 | union in_addr_union address; | |
a7f7d1bd | 467 | int family = AF_UNSPEC; |
ec2c5e43 LP |
468 | |
469 | /* Otherwise, try to talk to the owner of a | |
470 | * the IP address, in case this is a reverse | |
471 | * PTR lookup */ | |
f52e61da LP |
472 | |
473 | r = dns_name_address(DNS_RESOURCE_KEY_NAME(t->key), &family, &address); | |
ec2c5e43 LP |
474 | if (r < 0) |
475 | return r; | |
476 | if (r == 0) | |
477 | return -EINVAL; | |
9e08a6e0 | 478 | if (family != t->scope->family) |
9318cdd3 | 479 | return -ESRCH; |
ec2c5e43 | 480 | |
519ef046 | 481 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 482 | } |
106784eb DM |
483 | |
484 | break; | |
485 | ||
486 | default: | |
ec2c5e43 | 487 | return -EAFNOSUPPORT; |
106784eb | 488 | } |
ec2c5e43 LP |
489 | |
490 | if (fd < 0) | |
491 | return fd; | |
492 | ||
493 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
494 | if (r < 0) | |
495 | return r; | |
ec2c5e43 LP |
496 | fd = -1; |
497 | ||
498 | r = dns_stream_write_packet(t->stream, t->sent); | |
499 | if (r < 0) { | |
500 | t->stream = dns_stream_free(t->stream); | |
501 | return r; | |
502 | } | |
503 | ||
ec2c5e43 LP |
504 | t->stream->complete = on_stream_complete; |
505 | t->stream->transaction = t; | |
506 | ||
507 | /* The interface index is difficult to determine if we are | |
508 | * connecting to the local host, hence fill this in right away | |
509 | * instead of determining it from the socket */ | |
510 | if (t->scope->link) | |
511 | t->stream->ifindex = t->scope->link->ifindex; | |
512 | ||
519ef046 LP |
513 | dns_transaction_reset_answer(t); |
514 | ||
cbe4216d LP |
515 | t->tried_stream = true; |
516 | ||
ec2c5e43 LP |
517 | return 0; |
518 | } | |
519 | ||
547973de | 520 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
521 | assert(t); |
522 | ||
523 | /* For mDNS we cache whenever we get the packet, rather than | |
524 | * in each transaction. */ | |
525 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
526 | return; | |
527 | ||
528 | /* We never cache if this packet is from the local host, under | |
529 | * the assumption that a locally running DNS server would | |
530 | * cache this anyway, and probably knows better when to flush | |
531 | * the cache then we could. */ | |
532 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
533 | return; | |
534 | ||
547973de LP |
535 | dns_cache_put(&t->scope->cache, |
536 | t->key, | |
537 | t->answer_rcode, | |
538 | t->answer, | |
547973de | 539 | t->answer_authenticated, |
d3760be0 | 540 | t->answer_nsec_ttl, |
547973de LP |
541 | 0, |
542 | t->received->family, | |
543 | &t->received->sender); | |
544 | } | |
545 | ||
105e1512 LP |
546 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
547 | DnsTransaction *dt; | |
548 | Iterator i; | |
549 | ||
550 | assert(t); | |
551 | ||
552 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
553 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
554 | return true; | |
555 | ||
556 | return false; | |
557 | } | |
558 | ||
547973de LP |
559 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
560 | int r; | |
561 | ||
562 | assert(t); | |
563 | ||
564 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
105e1512 | 565 | if (dns_transaction_dnssec_is_live(t)) |
547973de LP |
566 | return; |
567 | ||
c02cf2f4 LP |
568 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
569 | * restart the lookup immediately. */ | |
570 | r = dns_transaction_maybe_restart(t); | |
571 | if (r < 0) { | |
572 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
573 | return; | |
574 | } | |
575 | if (r > 0) /* Transaction got restarted... */ | |
576 | return; | |
577 | ||
547973de LP |
578 | /* All our auxiliary DNSSEC transactions are complete now. Try |
579 | * to validate our RRset now. */ | |
580 | r = dns_transaction_validate_dnssec(t); | |
581 | if (r < 0) { | |
582 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
583 | return; | |
584 | } | |
585 | ||
b652d4a2 LP |
586 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
587 | t->scope->dnssec_mode == DNSSEC_YES) { | |
588 | /* We are not in automatic downgrade mode, and the | |
589 | * server is bad, refuse operation. */ | |
590 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
591 | return; | |
592 | } | |
593 | ||
019036a4 | 594 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
595 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
596 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
597 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
598 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
599 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
600 | return; | |
601 | } | |
602 | ||
603 | dns_transaction_cache_answer(t); | |
604 | ||
605 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
606 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
607 | else | |
3bbdc31d | 608 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
547973de LP |
609 | } |
610 | ||
ec2c5e43 | 611 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 612 | usec_t ts; |
ec2c5e43 LP |
613 | int r; |
614 | ||
615 | assert(t); | |
616 | assert(p); | |
9df3ba6c TG |
617 | assert(t->scope); |
618 | assert(t->scope->manager); | |
ec2c5e43 | 619 | |
5a7e41a3 LP |
620 | if (t->state != DNS_TRANSACTION_PENDING) |
621 | return; | |
622 | ||
ec2c5e43 LP |
623 | /* Note that this call might invalidate the query. Callers |
624 | * should hence not attempt to access the query or transaction | |
625 | * after calling this function. */ | |
626 | ||
b5efcf29 LP |
627 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
628 | ||
106784eb | 629 | switch (t->scope->protocol) { |
b5efcf29 | 630 | |
106784eb | 631 | case DNS_PROTOCOL_LLMNR: |
ec2c5e43 LP |
632 | assert(t->scope->link); |
633 | ||
634 | /* For LLMNR we will not accept any packets from other | |
635 | * interfaces */ | |
636 | ||
637 | if (p->ifindex != t->scope->link->ifindex) | |
638 | return; | |
639 | ||
640 | if (p->family != t->scope->family) | |
641 | return; | |
642 | ||
643 | /* Tentative packets are not full responses but still | |
644 | * useful for identifying uniqueness conflicts during | |
645 | * probing. */ | |
8b757a38 | 646 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
647 | dns_transaction_tentative(t, p); |
648 | return; | |
649 | } | |
106784eb DM |
650 | |
651 | break; | |
652 | ||
4e5bf5e1 DM |
653 | case DNS_PROTOCOL_MDNS: |
654 | assert(t->scope->link); | |
655 | ||
656 | /* For mDNS we will not accept any packets from other interfaces */ | |
657 | if (p->ifindex != t->scope->link->ifindex) | |
658 | return; | |
659 | ||
660 | if (p->family != t->scope->family) | |
661 | return; | |
662 | ||
663 | break; | |
664 | ||
106784eb | 665 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
666 | /* Note that we do not need to verify the |
667 | * addresses/port numbers of incoming traffic, as we | |
668 | * invoked connect() on our UDP socket in which case | |
669 | * the kernel already does the needed verification for | |
670 | * us. */ | |
106784eb DM |
671 | break; |
672 | ||
673 | default: | |
9c56a6f3 | 674 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
675 | } |
676 | ||
ec2c5e43 LP |
677 | if (t->received != p) { |
678 | dns_packet_unref(t->received); | |
679 | t->received = dns_packet_ref(p); | |
680 | } | |
681 | ||
c3bc53e6 LP |
682 | t->answer_source = DNS_TRANSACTION_NETWORK; |
683 | ||
ec2c5e43 LP |
684 | if (p->ipproto == IPPROTO_TCP) { |
685 | if (DNS_PACKET_TC(p)) { | |
686 | /* Truncated via TCP? Somebody must be fucking with us */ | |
687 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
688 | return; | |
689 | } | |
690 | ||
691 | if (DNS_PACKET_ID(p) != t->id) { | |
692 | /* Not the reply to our query? Somebody must be fucking with us */ | |
693 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
694 | return; | |
695 | } | |
696 | } | |
697 | ||
38a03f06 | 698 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
699 | |
700 | switch (t->scope->protocol) { | |
8af5b883 | 701 | |
9df3ba6c TG |
702 | case DNS_PROTOCOL_DNS: |
703 | assert(t->server); | |
704 | ||
4e0b8b17 TG |
705 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
706 | ||
8af5b883 | 707 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 TG |
708 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
709 | ||
274b8748 | 710 | dns_server_packet_failed(t->server, t->current_feature_level); |
8d10d620 | 711 | dns_transaction_retry(t); |
4e0b8b17 | 712 | return; |
6bb2c085 | 713 | } else if (DNS_PACKET_TC(p)) |
274b8748 | 714 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
715 | |
716 | break; | |
8af5b883 | 717 | |
9df3ba6c TG |
718 | case DNS_PROTOCOL_LLMNR: |
719 | case DNS_PROTOCOL_MDNS: | |
720 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 721 | break; |
8af5b883 | 722 | |
9df3ba6c | 723 | default: |
8af5b883 | 724 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
725 | } |
726 | ||
ec2c5e43 | 727 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
728 | |
729 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
730 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
731 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
732 | return; | |
733 | } | |
734 | ||
f757cd85 LP |
735 | log_debug("Reply truncated, retrying via TCP."); |
736 | ||
ec2c5e43 LP |
737 | /* Response was truncated, let's try again with good old TCP */ |
738 | r = dns_transaction_open_tcp(t); | |
739 | if (r == -ESRCH) { | |
740 | /* No servers found? Damn! */ | |
741 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
742 | return; | |
743 | } | |
91adc4db LP |
744 | if (r == -EOPNOTSUPP) { |
745 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
746 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
747 | return; | |
748 | } | |
ec2c5e43 | 749 | if (r < 0) { |
8af5b883 | 750 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 751 | * we immediately give up */ |
034e8031 | 752 | if (t->scope->protocol != DNS_PROTOCOL_DNS) { |
ec2c5e43 LP |
753 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); |
754 | return; | |
755 | } | |
756 | ||
757 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
8d10d620 | 758 | dns_transaction_retry(t); |
ec2c5e43 | 759 | } |
2a6658ef LP |
760 | |
761 | return; | |
ec2c5e43 LP |
762 | } |
763 | ||
de54e62b | 764 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
765 | r = dns_packet_extract(p); |
766 | if (r < 0) { | |
767 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
768 | return; | |
769 | } | |
770 | ||
de54e62b | 771 | /* Report that the OPT RR was missing */ |
ed9717fc LP |
772 | if (t->server) { |
773 | if (!p->opt) | |
774 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
775 | ||
776 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); | |
777 | } | |
de54e62b | 778 | |
c02cf2f4 LP |
779 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
780 | r = dns_transaction_maybe_restart(t); | |
781 | if (r < 0) { | |
782 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
783 | return; | |
784 | } | |
785 | if (r > 0) /* Transaction got restarted... */ | |
786 | return; | |
787 | ||
b5efcf29 LP |
788 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { |
789 | ||
547493c5 | 790 | /* Only consider responses with equivalent query section to the request */ |
8af5b883 LP |
791 | r = dns_packet_is_reply_for(p, t->key); |
792 | if (r < 0) { | |
793 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
794 | return; | |
795 | } | |
796 | if (r == 0) { | |
547493c5 DM |
797 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
798 | return; | |
799 | } | |
29815b6c | 800 | |
547493c5 DM |
801 | /* Install the answer as answer to the transaction */ |
802 | dns_answer_unref(t->answer); | |
803 | t->answer = dns_answer_ref(p->answer); | |
804 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 805 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 806 | t->answer_authenticated = false; |
79e24931 | 807 | |
51e399bc LP |
808 | /* Block GC while starting requests for additional DNSSEC RRs */ |
809 | t->block_gc++; | |
547973de | 810 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
811 | t->block_gc--; |
812 | ||
813 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
814 | if (!dns_transaction_gc(t)) | |
815 | return; | |
816 | ||
817 | /* Requesting additional keys might have resulted in | |
818 | * this transaction to fail, since the auxiliary | |
819 | * request failed for some reason. If so, we are not | |
820 | * in pending state anymore, and we should exit | |
821 | * quickly. */ | |
822 | if (t->state != DNS_TRANSACTION_PENDING) | |
823 | return; | |
547973de LP |
824 | if (r < 0) { |
825 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
826 | return; | |
827 | } | |
828 | if (r > 0) { | |
829 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
830 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
831 | dns_transaction_close_connection(t); |
832 | dns_transaction_stop_timeout(t); | |
547973de LP |
833 | return; |
834 | } | |
547493c5 | 835 | } |
ec2c5e43 | 836 | |
547973de | 837 | dns_transaction_process_dnssec(t); |
ec2c5e43 LP |
838 | } |
839 | ||
c19ffd9f TG |
840 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
841 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
842 | DnsTransaction *t = userdata; | |
843 | int r; | |
844 | ||
845 | assert(t); | |
846 | assert(t->scope); | |
847 | ||
848 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
849 | if (ERRNO_IS_DISCONNECT(-r)) { |
850 | usec_t usec; | |
c19ffd9f | 851 | |
7e1851e3 LP |
852 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
853 | * recvmsg(). Treat this like a lost packet. */ | |
854 | ||
92ec902a | 855 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 856 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 857 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 LP |
858 | |
859 | dns_transaction_retry(t); | |
860 | return 0; | |
861 | } | |
862 | if (r < 0) { | |
863 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
864 | return 0; | |
865 | } | |
866 | ||
867 | r = dns_packet_validate_reply(p); | |
868 | if (r < 0) { | |
869 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
870 | return 0; | |
871 | } | |
872 | if (r == 0) { | |
873 | log_debug("Received inappropriate DNS packet as response, ignoring: %m"); | |
874 | return 0; | |
875 | } | |
876 | ||
877 | if (DNS_PACKET_ID(p) != t->id) { | |
878 | log_debug("Received packet with incorrect transaction ID, ignoring: %m"); | |
879 | return 0; | |
880 | } | |
c19ffd9f | 881 | |
7e1851e3 | 882 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
883 | return 0; |
884 | } | |
885 | ||
49cce12d | 886 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
887 | int r; |
888 | ||
889 | assert(t); | |
c19ffd9f | 890 | |
519ef046 | 891 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 892 | |
519ef046 | 893 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
894 | if (r < 0) |
895 | return r; | |
c19ffd9f | 896 | |
274b8748 | 897 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
519ef046 LP |
898 | return -EAGAIN; |
899 | ||
92ec902a | 900 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
901 | return -EOPNOTSUPP; |
902 | ||
519ef046 LP |
903 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
904 | int fd; | |
905 | ||
906 | dns_transaction_close_connection(t); | |
c19ffd9f | 907 | |
519ef046 LP |
908 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
909 | if (fd < 0) | |
910 | return fd; | |
911 | ||
912 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
913 | if (r < 0) { | |
914 | safe_close(fd); | |
915 | return r; | |
916 | } | |
917 | ||
aa4a9deb | 918 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
919 | t->dns_udp_fd = fd; |
920 | } | |
921 | ||
274b8748 | 922 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
923 | if (r < 0) |
924 | return r; | |
925 | } else | |
926 | dns_transaction_close_connection(t); | |
927 | ||
928 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
929 | if (r < 0) |
930 | return r; | |
c19ffd9f | 931 | |
519ef046 | 932 | dns_transaction_reset_answer(t); |
be808ea0 | 933 | |
471d40d9 | 934 | return 0; |
c19ffd9f TG |
935 | } |
936 | ||
ec2c5e43 LP |
937 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
938 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
939 | |
940 | assert(s); | |
941 | assert(t); | |
942 | ||
ef7ce6df DM |
943 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
944 | /* Timeout reached? Increase the timeout for the server used */ | |
945 | switch (t->scope->protocol) { | |
49cce12d | 946 | |
ef7ce6df DM |
947 | case DNS_PROTOCOL_DNS: |
948 | assert(t->server); | |
274b8748 | 949 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 950 | break; |
49cce12d | 951 | |
ef7ce6df DM |
952 | case DNS_PROTOCOL_LLMNR: |
953 | case DNS_PROTOCOL_MDNS: | |
954 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 955 | break; |
49cce12d | 956 | |
ef7ce6df DM |
957 | default: |
958 | assert_not_reached("Invalid DNS protocol."); | |
959 | } | |
960 | ||
961 | if (t->initial_jitter_scheduled) | |
962 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
963 | } |
964 | ||
423659ab LP |
965 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
966 | ||
8d10d620 | 967 | dns_transaction_retry(t); |
ec2c5e43 LP |
968 | return 0; |
969 | } | |
970 | ||
9df3ba6c TG |
971 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
972 | assert(t); | |
973 | assert(t->scope); | |
974 | ||
975 | switch (t->scope->protocol) { | |
49cce12d | 976 | |
9df3ba6c TG |
977 | case DNS_PROTOCOL_DNS: |
978 | assert(t->server); | |
9df3ba6c | 979 | return t->server->resend_timeout; |
49cce12d | 980 | |
9df3ba6c | 981 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
982 | assert(t->n_attempts > 0); |
983 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 984 | |
11a27c2e | 985 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 986 | return t->scope->resend_timeout; |
49cce12d | 987 | |
9df3ba6c TG |
988 | default: |
989 | assert_not_reached("Invalid DNS protocol."); | |
990 | } | |
991 | } | |
992 | ||
c842ff24 | 993 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
994 | int r; |
995 | ||
996 | assert(t); | |
997 | ||
f535705a | 998 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 999 | |
ec2c5e43 LP |
1000 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1001 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1002 | return 0; | |
1003 | } | |
1004 | ||
cbe4216d | 1005 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1006 | /* If we already tried via a stream, then we don't |
1007 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1008 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1009 | return 0; | |
1010 | } | |
1011 | ||
1012 | t->n_attempts++; | |
9df3ba6c | 1013 | t->start_usec = ts; |
c61d2b44 LP |
1014 | |
1015 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1016 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1017 | |
0d2cd476 LP |
1018 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1019 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1020 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1021 | if (r < 0) |
1022 | return r; | |
1023 | if (r > 0) { | |
1024 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1025 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1026 | t->answer_authenticated = true; |
0d2cd476 LP |
1027 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1028 | return 0; | |
1029 | } | |
b2b796b8 LP |
1030 | |
1031 | if (dns_name_is_root(DNS_RESOURCE_KEY_NAME(t->key)) && | |
1032 | t->key->type == DNS_TYPE_DS) { | |
1033 | ||
1034 | /* Hmm, this is a request for the root DS? A | |
1035 | * DS RR doesn't exist in the root zone, and | |
1036 | * if our trust anchor didn't know it either, | |
1037 | * this means we cannot do any DNSSEC logic | |
1038 | * anymore. */ | |
1039 | ||
1ed8c0fb | 1040 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1041 | /* We are in downgrade mode. In this |
1042 | * case, synthesize an unsigned empty | |
1043 | * response, so that the any lookup | |
1044 | * depending on this one can continue | |
1045 | * assuming there was no DS, and hence | |
1046 | * the root zone was unsigned. */ | |
1047 | ||
1048 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1049 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1050 | t->answer_authenticated = false; | |
1051 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1052 | } else | |
1053 | /* If we are not in downgrade mode, | |
1054 | * then fail the lookup, because we | |
1055 | * cannot reasonably answer it. There | |
1056 | * might be DS RRs, but we don't know | |
1057 | * them, and the DNS server won't tell | |
1058 | * them to us (and even if it would, | |
1059 | * we couldn't validate it and trust | |
1060 | * it). */ | |
1061 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); | |
1062 | ||
1063 | return 0; | |
1064 | } | |
0d2cd476 LP |
1065 | } |
1066 | ||
1067 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1068 | * for probing or verifying a zone item. */ |
547973de | 1069 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1070 | |
ae6a4bbf | 1071 | r = dns_zone_lookup(&t->scope->zone, t->key, &t->answer, NULL, NULL); |
d746bb3e LP |
1072 | if (r < 0) |
1073 | return r; | |
1074 | if (r > 0) { | |
ae6a4bbf | 1075 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1076 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1077 | t->answer_authenticated = true; |
d746bb3e LP |
1078 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1079 | return 0; | |
1080 | } | |
1081 | } | |
1082 | ||
4d926a69 LP |
1083 | /* Check the cache, but only if this transaction is not used |
1084 | * for probing or verifying a zone item. */ | |
547973de | 1085 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1086 | |
4d926a69 LP |
1087 | /* Before trying the cache, let's make sure we figured out a |
1088 | * server to use. Should this cause a change of server this | |
1089 | * might flush the cache. */ | |
1090 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 1091 | |
4d926a69 LP |
1092 | /* Let's then prune all outdated entries */ |
1093 | dns_cache_prune(&t->scope->cache); | |
1094 | ||
931851e8 | 1095 | r = dns_cache_lookup(&t->scope->cache, t->key, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1096 | if (r < 0) |
1097 | return r; | |
1098 | if (r > 0) { | |
c3bc53e6 | 1099 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1100 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1101 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1102 | else | |
3bbdc31d | 1103 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1104 | return 0; |
1105 | } | |
ec2c5e43 LP |
1106 | } |
1107 | ||
1effe965 DM |
1108 | return 1; |
1109 | } | |
1110 | ||
0afa57e2 DM |
1111 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1112 | ||
1113 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1114 | bool add_known_answers = false; |
0afa57e2 DM |
1115 | DnsTransaction *other; |
1116 | unsigned qdcount; | |
1117 | usec_t ts; | |
1118 | int r; | |
1119 | ||
1120 | assert(t); | |
1121 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1122 | ||
e5abebab | 1123 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1124 | t->sent = dns_packet_unref(t->sent); |
1125 | ||
1126 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1127 | if (r < 0) | |
1128 | return r; | |
1129 | ||
1130 | r = dns_packet_append_key(p, t->key, NULL); | |
1131 | if (r < 0) | |
1132 | return r; | |
1133 | ||
1134 | qdcount = 1; | |
1135 | ||
7778dfff DM |
1136 | if (dns_key_is_shared(t->key)) |
1137 | add_known_answers = true; | |
1138 | ||
0afa57e2 DM |
1139 | /* |
1140 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1141 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1142 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1143 | */ | |
1144 | ||
1145 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1146 | ||
1147 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1148 | ||
1149 | /* Skip ourselves */ | |
1150 | if (other == t) | |
1151 | continue; | |
1152 | ||
1153 | if (other->state != DNS_TRANSACTION_PENDING) | |
1154 | continue; | |
1155 | ||
1156 | if (other->next_attempt_after > ts) | |
1157 | continue; | |
1158 | ||
1159 | if (qdcount >= UINT16_MAX) | |
1160 | break; | |
1161 | ||
1162 | r = dns_packet_append_key(p, other->key, NULL); | |
1163 | ||
1164 | /* | |
1165 | * If we can't stuff more questions into the packet, just give up. | |
1166 | * One of the 'other' transactions will fire later and take care of the rest. | |
1167 | */ | |
1168 | if (r == -EMSGSIZE) | |
1169 | break; | |
1170 | ||
1171 | if (r < 0) | |
1172 | return r; | |
1173 | ||
c842ff24 | 1174 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1175 | if (r <= 0) |
1176 | continue; | |
1177 | ||
1178 | ts += transaction_get_resend_timeout(other); | |
1179 | ||
1180 | r = sd_event_add_time( | |
1181 | other->scope->manager->event, | |
1182 | &other->timeout_event_source, | |
1183 | clock_boottime_or_monotonic(), | |
1184 | ts, 0, | |
1185 | on_transaction_timeout, other); | |
1186 | if (r < 0) | |
1187 | return r; | |
1188 | ||
aa4a9deb LP |
1189 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1190 | ||
0afa57e2 DM |
1191 | other->state = DNS_TRANSACTION_PENDING; |
1192 | other->next_attempt_after = ts; | |
1193 | ||
1194 | qdcount ++; | |
7778dfff DM |
1195 | |
1196 | if (dns_key_is_shared(other->key)) | |
1197 | add_known_answers = true; | |
0afa57e2 DM |
1198 | } |
1199 | ||
1200 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1201 | |
7778dfff DM |
1202 | /* Append known answer section if we're asking for any shared record */ |
1203 | if (add_known_answers) { | |
1204 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1205 | if (r < 0) | |
1206 | return r; | |
1207 | } | |
1208 | ||
0afa57e2 DM |
1209 | t->sent = p; |
1210 | p = NULL; | |
1211 | ||
1212 | return 0; | |
1213 | } | |
1214 | ||
1215 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1216 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1217 | int r; | |
1218 | ||
1219 | assert(t); | |
1220 | ||
1221 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1222 | return dns_transaction_make_packet_mdns(t); | |
1223 | ||
1224 | if (t->sent) | |
1225 | return 0; | |
1226 | ||
b652d4a2 | 1227 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1228 | if (r < 0) |
1229 | return r; | |
1230 | ||
1231 | r = dns_scope_good_key(t->scope, t->key); | |
1232 | if (r < 0) | |
1233 | return r; | |
1234 | if (r == 0) | |
1235 | return -EDOM; | |
1236 | ||
1237 | r = dns_packet_append_key(p, t->key, NULL); | |
1238 | if (r < 0) | |
1239 | return r; | |
1240 | ||
1241 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1242 | DNS_PACKET_HEADER(p)->id = t->id; | |
1243 | ||
1244 | t->sent = p; | |
1245 | p = NULL; | |
1246 | ||
1247 | return 0; | |
1248 | } | |
1249 | ||
1effe965 DM |
1250 | int dns_transaction_go(DnsTransaction *t) { |
1251 | usec_t ts; | |
1252 | int r; | |
1253 | ||
1254 | assert(t); | |
1255 | ||
1256 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
547973de | 1257 | |
c842ff24 | 1258 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1259 | if (r <= 0) |
1260 | return r; | |
1261 | ||
a5784c49 LP |
1262 | log_debug("Excercising transaction %" PRIu16 " for <%s> on scope %s on %s/%s.", |
1263 | t->id, | |
1264 | dns_transaction_key_string(t), | |
1265 | dns_protocol_to_string(t->scope->protocol), | |
1266 | t->scope->link ? t->scope->link->name : "*", | |
1267 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); | |
1effe965 | 1268 | |
ef7ce6df | 1269 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1270 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1271 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1272 | usec_t jitter, accuracy; | |
6e068472 LP |
1273 | |
1274 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1275 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1276 | ||
ef7ce6df | 1277 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1278 | |
1279 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1280 | |
1281 | switch (t->scope->protocol) { | |
519ef046 | 1282 | |
ea12bcc7 DM |
1283 | case DNS_PROTOCOL_LLMNR: |
1284 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1285 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1286 | break; | |
519ef046 | 1287 | |
ea12bcc7 DM |
1288 | case DNS_PROTOCOL_MDNS: |
1289 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1290 | jitter += MDNS_JITTER_MIN_USEC; | |
1291 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1292 | break; | |
1293 | default: | |
1294 | assert_not_reached("bad protocol"); | |
1295 | } | |
6e068472 LP |
1296 | |
1297 | r = sd_event_add_time( | |
1298 | t->scope->manager->event, | |
1299 | &t->timeout_event_source, | |
1300 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1301 | ts + jitter, accuracy, |
6e068472 LP |
1302 | on_transaction_timeout, t); |
1303 | if (r < 0) | |
1304 | return r; | |
1305 | ||
aa4a9deb LP |
1306 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1307 | ||
6e068472 | 1308 | t->n_attempts = 0; |
a9da14e1 | 1309 | t->next_attempt_after = ts; |
6e068472 LP |
1310 | t->state = DNS_TRANSACTION_PENDING; |
1311 | ||
ea12bcc7 | 1312 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1313 | return 0; |
1314 | } | |
1315 | ||
ec2c5e43 LP |
1316 | /* Otherwise, we need to ask the network */ |
1317 | r = dns_transaction_make_packet(t); | |
1318 | if (r == -EDOM) { | |
1319 | /* Not the right request to make on this network? | |
1320 | * (i.e. an A request made on IPv6 or an AAAA request | |
1321 | * made on IPv4, on LLMNR or mDNS.) */ | |
1322 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1323 | return 0; | |
1324 | } | |
1325 | if (r < 0) | |
1326 | return r; | |
1327 | ||
1328 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
f52e61da LP |
1329 | (dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "in-addr.arpa") > 0 || |
1330 | dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1331 | |
1332 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1333 | * always be made via TCP on LLMNR */ | |
1334 | r = dns_transaction_open_tcp(t); | |
1335 | } else { | |
be808ea0 TG |
1336 | /* Try via UDP, and if that fails due to large size or lack of |
1337 | * support try via TCP */ | |
49cce12d | 1338 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1339 | if (r == -EMSGSIZE) |
1340 | log_debug("Sending query via TCP since it is too large."); | |
034e8031 LP |
1341 | if (r == -EAGAIN) |
1342 | log_debug("Sending query via TCP since server doesn't support UDP."); | |
be808ea0 | 1343 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1344 | r = dns_transaction_open_tcp(t); |
1345 | } | |
be808ea0 | 1346 | |
ec2c5e43 LP |
1347 | if (r == -ESRCH) { |
1348 | /* No servers to send this to? */ | |
1349 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1350 | return 0; | |
91adc4db LP |
1351 | } |
1352 | if (r == -EOPNOTSUPP) { | |
1353 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1354 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1355 | return 0; | |
1356 | } | |
1357 | if (r < 0) { | |
13b551ac LP |
1358 | if (t->scope->protocol != DNS_PROTOCOL_DNS) { |
1359 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
1360 | return 0; | |
1361 | } | |
1362 | ||
ec2c5e43 | 1363 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1364 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1365 | |
1366 | return dns_transaction_go(t); | |
1367 | } | |
1368 | ||
a9da14e1 DM |
1369 | ts += transaction_get_resend_timeout(t); |
1370 | ||
9a015429 LP |
1371 | r = sd_event_add_time( |
1372 | t->scope->manager->event, | |
1373 | &t->timeout_event_source, | |
1374 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1375 | ts, 0, |
9a015429 | 1376 | on_transaction_timeout, t); |
ec2c5e43 LP |
1377 | if (r < 0) |
1378 | return r; | |
1379 | ||
aa4a9deb LP |
1380 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1381 | ||
ec2c5e43 | 1382 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1383 | t->next_attempt_after = ts; |
1384 | ||
ec2c5e43 LP |
1385 | return 1; |
1386 | } | |
1387 | ||
f2992dc1 LP |
1388 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1389 | DnsTransaction *n; | |
1390 | Iterator i; | |
1391 | int r; | |
1392 | ||
1393 | assert(t); | |
1394 | assert(aux); | |
1395 | ||
1396 | /* Try to find cyclic dependencies between transaction objects */ | |
1397 | ||
1398 | if (t == aux) | |
1399 | return 1; | |
1400 | ||
3eb6aa00 | 1401 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1402 | r = dns_transaction_find_cyclic(t, n); |
1403 | if (r != 0) | |
1404 | return r; | |
1405 | } | |
1406 | ||
3eb6aa00 | 1407 | return 0; |
f2992dc1 LP |
1408 | } |
1409 | ||
547973de LP |
1410 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1411 | DnsTransaction *aux; | |
1412 | int r; | |
1413 | ||
1414 | assert(t); | |
1415 | assert(ret); | |
1416 | assert(key); | |
1417 | ||
1418 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1419 | if (!aux) { | |
1420 | r = dns_transaction_new(&aux, t->scope, key); | |
1421 | if (r < 0) | |
1422 | return r; | |
1423 | } else { | |
1424 | if (set_contains(t->dnssec_transactions, aux)) { | |
1425 | *ret = aux; | |
1426 | return 0; | |
1427 | } | |
f2992dc1 LP |
1428 | |
1429 | r = dns_transaction_find_cyclic(t, aux); | |
1430 | if (r < 0) | |
1431 | return r; | |
1432 | if (r > 0) { | |
1433 | log_debug("Detected potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1434 | aux->id, | |
1435 | strna(dns_transaction_key_string(aux)), | |
1436 | t->id, | |
1437 | strna(dns_transaction_key_string(t))); | |
1438 | return -ELOOP; | |
1439 | } | |
547973de LP |
1440 | } |
1441 | ||
1442 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1443 | if (r < 0) | |
1444 | goto gc; | |
1445 | ||
1446 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1447 | if (r < 0) | |
1448 | goto gc; | |
1449 | ||
1450 | r = set_put(t->dnssec_transactions, aux); | |
1451 | if (r < 0) | |
1452 | goto gc; | |
1453 | ||
1454 | r = set_put(aux->notify_transactions, t); | |
1455 | if (r < 0) { | |
1456 | (void) set_remove(t->dnssec_transactions, aux); | |
1457 | goto gc; | |
1458 | } | |
1459 | ||
1460 | *ret = aux; | |
1461 | return 1; | |
1462 | ||
1463 | gc: | |
1464 | dns_transaction_gc(aux); | |
1465 | return r; | |
1466 | } | |
1467 | ||
1468 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1469 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1470 | DnsTransaction *aux; | |
1471 | int r; | |
1472 | ||
1473 | assert(t); | |
1474 | assert(key); | |
1475 | ||
1476 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1477 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1478 | if (r < 0) |
1479 | return r; | |
1480 | if (r > 0) { | |
1481 | r = dns_answer_extend(&t->validated_keys, a); | |
1482 | if (r < 0) | |
1483 | return r; | |
1484 | ||
1485 | return 0; | |
1486 | } | |
1487 | ||
1488 | /* This didn't work, ask for it via the network/cache then. */ | |
1489 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1490 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1491 | return 0; | |
547973de LP |
1492 | if (r < 0) |
1493 | return r; | |
1494 | ||
1495 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1496 | r = dns_transaction_go(aux); | |
1497 | if (r < 0) | |
1498 | return r; | |
1499 | } | |
1500 | ||
f2992dc1 | 1501 | return 1; |
547973de LP |
1502 | } |
1503 | ||
105e1512 LP |
1504 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
1505 | int r; | |
1506 | ||
1507 | assert(t); | |
1508 | ||
1509 | /* Checks whether the answer is positive, i.e. either a direct | |
1510 | * answer to the question, or a CNAME/DNAME for it */ | |
1511 | ||
1512 | r = dns_answer_match_key(t->answer, t->key, flags); | |
1513 | if (r != 0) | |
1514 | return r; | |
1515 | ||
1516 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
1517 | if (r != 0) | |
1518 | return r; | |
1519 | ||
1520 | return false; | |
1521 | } | |
1522 | ||
8a516214 LP |
1523 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1524 | int r; | |
1525 | ||
1526 | assert(t); | |
1527 | ||
1528 | /* Check whether the specified name is in the the NTA | |
1529 | * database, either in the global one, or the link-local | |
1530 | * one. */ | |
1531 | ||
1532 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1533 | if (r != 0) | |
1534 | return r; | |
1535 | ||
1536 | if (!t->scope->link) | |
1537 | return 0; | |
1538 | ||
1539 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1540 | } | |
1541 | ||
105e1512 LP |
1542 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1543 | int r; | |
1544 | ||
1545 | assert(t); | |
1546 | ||
1547 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1548 | * RRs to prove it */ | |
1549 | ||
1550 | r = dns_transaction_has_positive_answer(t, NULL); | |
1551 | if (r < 0) | |
1552 | return r; | |
1553 | if (r > 0) | |
1554 | return false; | |
1555 | ||
8e54f5d9 LP |
1556 | /* Is this key explicitly listed as a negative trust anchor? |
1557 | * If so, it's nothing we need to care about */ | |
8a516214 | 1558 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); |
8e54f5d9 LP |
1559 | if (r < 0) |
1560 | return r; | |
1561 | if (r > 0) | |
1562 | return false; | |
1563 | ||
105e1512 LP |
1564 | /* The answer does not contain any RRs that match to the |
1565 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1566 | * included. If not, the answer is unsigned. */ | |
1567 | ||
1568 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1569 | if (r < 0) | |
1570 | return r; | |
1571 | if (r > 0) | |
1572 | return false; | |
1573 | ||
1574 | return true; | |
1575 | } | |
1576 | ||
1577 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1578 | int r; | |
1579 | ||
1580 | assert(t); | |
1581 | assert(rr); | |
1582 | ||
1583 | /* Check if the specified RR is the "primary" response, | |
1584 | * i.e. either matches the question precisely or is a | |
1585 | * CNAME/DNAME for it, or is any kind of NSEC/NSEC3 RR */ | |
1586 | ||
1587 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1588 | if (r != 0) | |
1589 | return r; | |
1590 | ||
1591 | r = dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); | |
1592 | if (r != 0) | |
1593 | return r; | |
1594 | ||
1595 | if (rr->key->type == DNS_TYPE_NSEC3) { | |
1596 | const char *p; | |
1597 | ||
1598 | p = DNS_RESOURCE_KEY_NAME(rr->key); | |
1599 | r = dns_name_parent(&p); | |
1600 | if (r < 0) | |
1601 | return r; | |
1602 | if (r > 0) { | |
1603 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), p); | |
1604 | if (r < 0) | |
1605 | return r; | |
1606 | if (r > 0) | |
1607 | return true; | |
1608 | } | |
1609 | } | |
1610 | ||
1611 | return rr->key->type == DNS_TYPE_NSEC; | |
1612 | } | |
1613 | ||
92ec902a LP |
1614 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1615 | assert(t); | |
1616 | ||
1617 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1618 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1619 | ||
1620 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1621 | return false; | |
1622 | ||
1623 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1624 | * be supported, hence return true. */ | |
1625 | if (!t->server) | |
1626 | return true; | |
1627 | ||
274b8748 | 1628 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_DO) |
92ec902a LP |
1629 | return false; |
1630 | ||
1631 | return dns_server_dnssec_supported(t->server); | |
1632 | } | |
1633 | ||
1634 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1635 | DnsTransaction *dt; | |
1636 | Iterator i; | |
1637 | ||
1638 | assert(t); | |
1639 | ||
1640 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1641 | ||
1642 | if (!dns_transaction_dnssec_supported(t)) | |
1643 | return false; | |
1644 | ||
1645 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1646 | if (!dns_transaction_dnssec_supported(dt)) | |
1647 | return false; | |
1648 | ||
1649 | return true; | |
1650 | } | |
1651 | ||
547973de LP |
1652 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1653 | DnsResourceRecord *rr; | |
105e1512 | 1654 | |
547973de LP |
1655 | int r; |
1656 | ||
1657 | assert(t); | |
1658 | ||
105e1512 LP |
1659 | /* |
1660 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1661 | * we can verify signatures or prove that RRs are rightfully | |
1662 | * unsigned. Specifically: | |
1663 | * | |
1664 | * - For RRSIG we get the matching DNSKEY | |
1665 | * - For DNSKEY we get the matching DS | |
1666 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1667 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 LP |
1668 | * - For other unsigned RRs we get the matching SOA RR |
1669 | * - For SOA/NS/DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
1670 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR | |
1671 | */ | |
1672 | ||
b652d4a2 | 1673 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1674 | return 0; |
92ec902a LP |
1675 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1676 | return 0; /* We only need to validate stuff from the network */ | |
1677 | if (!dns_transaction_dnssec_supported(t)) | |
1678 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1679 | |
547973de LP |
1680 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1681 | ||
105e1512 LP |
1682 | if (dns_type_is_pseudo(rr->key->type)) |
1683 | continue; | |
1684 | ||
8e54f5d9 | 1685 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
8a516214 | 1686 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
1687 | if (r < 0) |
1688 | return r; | |
1689 | if (r > 0) | |
1690 | continue; | |
1691 | ||
547973de LP |
1692 | switch (rr->key->type) { |
1693 | ||
1694 | case DNS_TYPE_RRSIG: { | |
1695 | /* For each RRSIG we request the matching DNSKEY */ | |
1696 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1697 | ||
1698 | /* If this RRSIG is about a DNSKEY RR and the | |
1699 | * signer is the same as the owner, then we | |
1700 | * already have the DNSKEY, and we don't have | |
1701 | * to look for more. */ | |
1702 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1703 | r = dns_name_equal(rr->rrsig.signer, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1704 | if (r < 0) | |
1705 | return r; | |
1706 | if (r > 0) | |
1707 | continue; | |
1708 | } | |
1709 | ||
105e1512 LP |
1710 | /* If the signer is not a parent of our |
1711 | * original query, then this is about an | |
1712 | * auxiliary RRset, but not anything we asked | |
1713 | * for. In this case we aren't interested, | |
1714 | * because we don't want to request additional | |
1715 | * RRs for stuff we didn't really ask for, and | |
1716 | * also to avoid request loops, where | |
1717 | * additional RRs from one transaction result | |
1718 | * in another transaction whose additonal RRs | |
1719 | * point back to the original transaction, and | |
1720 | * we deadlock. */ | |
1721 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), rr->rrsig.signer); | |
547973de LP |
1722 | if (r < 0) |
1723 | return r; | |
1724 | if (r == 0) | |
1725 | continue; | |
1726 | ||
1727 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1728 | if (!dnskey) | |
1729 | return -ENOMEM; | |
1730 | ||
105e1512 | 1731 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", t->id, DNS_RESOURCE_KEY_NAME(rr->key), rr->rrsig.key_tag); |
547973de LP |
1732 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1733 | if (r < 0) | |
1734 | return r; | |
1735 | break; | |
1736 | } | |
1737 | ||
1738 | case DNS_TYPE_DNSKEY: { | |
1739 | /* For each DNSKEY we request the matching DS */ | |
1740 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1741 | ||
105e1512 LP |
1742 | /* If the DNSKEY we are looking at is not for |
1743 | * zone we are interested in, nor any of its | |
1744 | * parents, we aren't interested, and don't | |
1745 | * request it. After all, we don't want to end | |
1746 | * up in request loops, and want to keep | |
1747 | * additional traffic down. */ | |
1748 | ||
1749 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1750 | if (r < 0) | |
1751 | return r; | |
1752 | if (r == 0) | |
1753 | continue; | |
1754 | ||
547973de LP |
1755 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); |
1756 | if (!ds) | |
1757 | return -ENOMEM; | |
1758 | ||
0c857028 | 1759 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", t->id, DNS_RESOURCE_KEY_NAME(rr->key), dnssec_keytag(rr, false)); |
105e1512 LP |
1760 | r = dns_transaction_request_dnssec_rr(t, ds); |
1761 | if (r < 0) | |
1762 | return r; | |
547973de | 1763 | |
105e1512 LP |
1764 | break; |
1765 | } | |
1766 | ||
105e1512 LP |
1767 | case DNS_TYPE_SOA: |
1768 | case DNS_TYPE_NS: { | |
1769 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1770 | ||
1771 | /* For an unsigned SOA or NS, try to acquire | |
1772 | * the matching DS RR, as we are at a zone cut | |
1773 | * then, and whether a DS exists tells us | |
1774 | * whether the zone is signed. Do so only if | |
1775 | * this RR matches our original question, | |
1776 | * however. */ | |
1777 | ||
1778 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1779 | if (r < 0) | |
1780 | return r; | |
1781 | if (r == 0) | |
1782 | continue; | |
1783 | ||
1784 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1785 | if (r < 0) | |
1786 | return r; | |
1787 | if (r > 0) | |
1788 | continue; | |
1789 | ||
1790 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1791 | if (!ds) | |
1792 | return -ENOMEM; | |
1793 | ||
1794 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); | |
547973de LP |
1795 | r = dns_transaction_request_dnssec_rr(t, ds); |
1796 | if (r < 0) | |
1797 | return r; | |
1798 | ||
1799 | break; | |
105e1512 LP |
1800 | } |
1801 | ||
b63fca62 | 1802 | case DNS_TYPE_DS: |
105e1512 LP |
1803 | case DNS_TYPE_CNAME: |
1804 | case DNS_TYPE_DNAME: { | |
1805 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1806 | const char *name; | |
1807 | ||
1808 | /* CNAMEs and DNAMEs cannot be located at a | |
1809 | * zone apex, hence ask for the parent SOA for | |
1810 | * unsigned CNAME/DNAME RRs, maybe that's the | |
1811 | * apex. But do all that only if this is | |
1812 | * actually a response to our original | |
b63fca62 LP |
1813 | * question. |
1814 | * | |
1815 | * Similar for DS RRs, which are signed when | |
1816 | * the parent SOA is signed. */ | |
105e1512 LP |
1817 | |
1818 | r = dns_transaction_is_primary_response(t, rr); | |
1819 | if (r < 0) | |
1820 | return r; | |
1821 | if (r == 0) | |
1822 | continue; | |
1823 | ||
1824 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1825 | if (r < 0) | |
1826 | return r; | |
1827 | if (r > 0) | |
1828 | continue; | |
1829 | ||
43e6779a LP |
1830 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
1831 | if (r < 0) | |
1832 | return r; | |
1833 | if (r > 0) | |
1834 | continue; | |
1835 | ||
105e1512 LP |
1836 | name = DNS_RESOURCE_KEY_NAME(rr->key); |
1837 | r = dns_name_parent(&name); | |
1838 | if (r < 0) | |
1839 | return r; | |
1840 | if (r == 0) | |
1841 | continue; | |
1842 | ||
1843 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
1844 | if (!soa) | |
1845 | return -ENOMEM; | |
1846 | ||
b63fca62 | 1847 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); |
105e1512 LP |
1848 | r = dns_transaction_request_dnssec_rr(t, soa); |
1849 | if (r < 0) | |
1850 | return r; | |
1851 | ||
1852 | break; | |
1853 | } | |
1854 | ||
1855 | default: { | |
1856 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1857 | ||
b63fca62 LP |
1858 | /* For other unsigned RRsets (including |
1859 | * NSEC/NSEC3!), look for proof the zone is | |
1860 | * unsigned, by requesting the SOA RR of the | |
1861 | * zone. However, do so only if they are | |
1862 | * directly relevant to our original | |
105e1512 LP |
1863 | * question. */ |
1864 | ||
1865 | r = dns_transaction_is_primary_response(t, rr); | |
1866 | if (r < 0) | |
1867 | return r; | |
1868 | if (r == 0) | |
1869 | continue; | |
1870 | ||
1871 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1872 | if (r < 0) | |
1873 | return r; | |
1874 | if (r > 0) | |
1875 | continue; | |
1876 | ||
1877 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1878 | if (!soa) | |
1879 | return -ENOMEM; | |
1880 | ||
db5b0e92 | 1881 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", t->id, DNS_RESOURCE_KEY_NAME(rr->key), dns_resource_record_to_string(rr)); |
105e1512 LP |
1882 | r = dns_transaction_request_dnssec_rr(t, soa); |
1883 | if (r < 0) | |
1884 | return r; | |
1885 | break; | |
547973de LP |
1886 | }} |
1887 | } | |
1888 | ||
105e1512 LP |
1889 | /* Above, we requested everything necessary to validate what |
1890 | * we got. Now, let's request what we need to validate what we | |
1891 | * didn't get... */ | |
1892 | ||
1893 | r = dns_transaction_has_unsigned_negative_answer(t); | |
1894 | if (r < 0) | |
1895 | return r; | |
1896 | if (r > 0) { | |
1897 | const char *name; | |
1898 | ||
1899 | name = DNS_RESOURCE_KEY_NAME(t->key); | |
1900 | ||
1901 | /* If this was a SOA or NS request, then this | |
1902 | * indicates that we are not at a zone apex, hence ask | |
1903 | * the parent name instead. If this was a DS request, | |
1904 | * then it's signed when the parent zone is signed, | |
1905 | * hence ask the parent in that case, too. */ | |
1906 | ||
1907 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
1908 | r = dns_name_parent(&name); | |
1909 | if (r < 0) | |
1910 | return r; | |
1911 | if (r > 0) | |
1912 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1913 | else | |
1914 | name = NULL; | |
1915 | } else | |
1916 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1917 | ||
1918 | if (name) { | |
1919 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1920 | ||
1921 | soa = dns_resource_key_new(t->key->class, DNS_TYPE_SOA, name); | |
1922 | if (!soa) | |
1923 | return -ENOMEM; | |
1924 | ||
1925 | r = dns_transaction_request_dnssec_rr(t, soa); | |
1926 | if (r < 0) | |
1927 | return r; | |
1928 | } | |
1929 | } | |
1930 | ||
1931 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
1932 | } |
1933 | ||
1934 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
1935 | int r; | |
1936 | ||
1937 | assert(t); | |
547973de LP |
1938 | assert(source); |
1939 | ||
105e1512 LP |
1940 | if (!IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) |
1941 | return; | |
1942 | ||
547973de | 1943 | /* Invoked whenever any of our auxiliary DNSSEC transactions |
105e1512 LP |
1944 | completed its work. We copy any RRs from that transaction |
1945 | over into our list of validated keys -- but only if the | |
1946 | answer is authenticated. | |
1947 | ||
1948 | Note that we fail our transaction if the auxiliary | |
1949 | transaction failed, except on NXDOMAIN. This is because | |
1950 | some broken DNS servers (Akamai...) will return NXDOMAIN | |
1951 | for empty non-terminals. */ | |
1952 | ||
6773896e | 1953 | switch (source->state) { |
547973de | 1954 | |
6773896e LP |
1955 | case DNS_TRANSACTION_DNSSEC_FAILED: |
1956 | ||
1957 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(source->answer_dnssec_result)); | |
1958 | t->answer_dnssec_result = source->answer_dnssec_result; /* Copy error code over */ | |
1959 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
1960 | break; | |
1961 | ||
1962 | case DNS_TRANSACTION_RCODE_FAILURE: | |
1963 | ||
1964 | if (source->answer_rcode != DNS_RCODE_NXDOMAIN) { | |
1965 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%i.", source->answer_rcode); | |
105e1512 | 1966 | goto fail; |
547973de | 1967 | } |
547973de | 1968 | |
6773896e LP |
1969 | /* fall-through: NXDOMAIN is good enough for us */ |
1970 | ||
1971 | case DNS_TRANSACTION_SUCCESS: | |
1972 | if (source->answer_authenticated) { | |
1973 | r = dns_answer_extend(&t->validated_keys, source->answer); | |
1974 | if (r < 0) { | |
1975 | log_error_errno(r, "Failed to merge validated DNSSEC key data: %m"); | |
1976 | goto fail; | |
1977 | } | |
1978 | } | |
1979 | ||
1980 | /* If the state is still PENDING, we are still in the loop | |
1981 | * that adds further DNSSEC transactions, hence don't check if | |
1982 | * we are ready yet. If the state is VALIDATING however, we | |
1983 | * should check if we are complete now. */ | |
1984 | if (t->state == DNS_TRANSACTION_VALIDATING) | |
1985 | dns_transaction_process_dnssec(t); | |
1986 | break; | |
1987 | ||
1988 | default: | |
1989 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(source->state)); | |
1990 | goto fail; | |
1991 | } | |
105e1512 LP |
1992 | |
1993 | return; | |
1994 | ||
1995 | fail: | |
019036a4 | 1996 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; |
105e1512 | 1997 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
547973de LP |
1998 | } |
1999 | ||
105e1512 LP |
2000 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2001 | DnsResourceRecord *rr; | |
2002 | int ifindex, r; | |
2003 | ||
2004 | assert(t); | |
2005 | ||
2006 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2007 | * RRs from the list of validated keys to the list of | |
2008 | * validated keys. */ | |
2009 | ||
2010 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2011 | ||
96bb7673 | 2012 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2013 | if (r < 0) |
2014 | return r; | |
2015 | if (r == 0) | |
2016 | continue; | |
2017 | ||
2018 | /* If so, the DNSKEY is validated too. */ | |
2019 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2020 | if (r < 0) | |
2021 | return r; | |
2022 | } | |
2023 | ||
2024 | return 0; | |
2025 | } | |
2026 | ||
2027 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2028 | int r; |
2029 | ||
2030 | assert(t); | |
2031 | assert(rr); | |
2032 | ||
105e1512 LP |
2033 | /* Checks if the RR we are looking for must be signed with an |
2034 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2035 | |
b652d4a2 | 2036 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2037 | return false; |
56352fe9 | 2038 | |
105e1512 LP |
2039 | if (dns_type_is_pseudo(rr->key->type)) |
2040 | return -EINVAL; | |
56352fe9 | 2041 | |
8a516214 | 2042 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
2043 | if (r < 0) |
2044 | return r; | |
2045 | if (r > 0) | |
2046 | return false; | |
2047 | ||
105e1512 | 2048 | switch (rr->key->type) { |
56352fe9 | 2049 | |
105e1512 LP |
2050 | case DNS_TYPE_RRSIG: |
2051 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2052 | return false; | |
2053 | ||
2054 | case DNS_TYPE_SOA: | |
2055 | case DNS_TYPE_NS: { | |
2056 | DnsTransaction *dt; | |
2057 | Iterator i; | |
2058 | ||
b63fca62 | 2059 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2060 | |
2061 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2062 | ||
2063 | if (dt->key->class != rr->key->class) | |
2064 | continue; | |
2065 | if (dt->key->type != DNS_TYPE_DS) | |
2066 | continue; | |
2067 | ||
2068 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
2069 | if (r < 0) | |
2070 | return r; | |
2071 | if (r == 0) | |
2072 | continue; | |
2073 | ||
2074 | /* We found a DS transactions for the SOA/NS | |
2075 | * RRs we are looking at. If it discovered signed DS | |
2076 | * RRs, then we need to be signed, too. */ | |
2077 | ||
097a2517 TA |
2078 | if (!dt->answer_authenticated) |
2079 | return false; | |
105e1512 | 2080 | |
097a2517 | 2081 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2082 | } |
2083 | ||
2084 | /* We found nothing that proves this is safe to leave | |
2085 | * this unauthenticated, hence ask inist on | |
2086 | * authentication. */ | |
2087 | return true; | |
2088 | } | |
2089 | ||
b63fca62 | 2090 | case DNS_TYPE_DS: |
105e1512 LP |
2091 | case DNS_TYPE_CNAME: |
2092 | case DNS_TYPE_DNAME: { | |
2093 | const char *parent = NULL; | |
2094 | DnsTransaction *dt; | |
2095 | Iterator i; | |
2096 | ||
b63fca62 LP |
2097 | /* |
2098 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2099 | * | |
2100 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2101 | */ | |
105e1512 LP |
2102 | |
2103 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2104 | ||
2105 | if (dt->key->class != rr->key->class) | |
2106 | continue; | |
2107 | if (dt->key->type != DNS_TYPE_SOA) | |
2108 | continue; | |
2109 | ||
2110 | if (!parent) { | |
2111 | parent = DNS_RESOURCE_KEY_NAME(rr->key); | |
2112 | r = dns_name_parent(&parent); | |
2113 | if (r < 0) | |
2114 | return r; | |
2115 | if (r == 0) { | |
b63fca62 LP |
2116 | if (rr->key->type == DNS_TYPE_DS) |
2117 | return true; | |
2118 | ||
105e1512 LP |
2119 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2120 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2121 | return -EBADMSG; | |
2122 | } | |
2123 | } | |
2124 | ||
2125 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), parent); | |
2126 | if (r < 0) | |
2127 | return r; | |
2128 | if (r == 0) | |
2129 | continue; | |
2130 | ||
2131 | return t->answer_authenticated; | |
2132 | } | |
2133 | ||
2134 | return true; | |
2135 | } | |
2136 | ||
2137 | default: { | |
2138 | DnsTransaction *dt; | |
2139 | Iterator i; | |
2140 | ||
b63fca62 | 2141 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2142 | |
2143 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2144 | ||
2145 | if (dt->key->class != rr->key->class) | |
2146 | continue; | |
2147 | if (dt->key->type != DNS_TYPE_SOA) | |
2148 | continue; | |
2149 | ||
2150 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
2151 | if (r < 0) | |
2152 | return r; | |
2153 | if (r == 0) | |
2154 | continue; | |
2155 | ||
2156 | /* We found the transaction that was supposed to find | |
2157 | * the SOA RR for us. It was successful, but found no | |
2158 | * RR for us. This means we are not at a zone cut. In | |
2159 | * this case, we require authentication if the SOA | |
2160 | * lookup was authenticated too. */ | |
2161 | return t->answer_authenticated; | |
2162 | } | |
2163 | ||
2164 | return true; | |
2165 | }} | |
56352fe9 LP |
2166 | } |
2167 | ||
d33b6cf3 LP |
2168 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2169 | DnsTransaction *dt; | |
2170 | const char *tld; | |
2171 | Iterator i; | |
2172 | int r; | |
2173 | ||
2174 | /* If DNSSEC downgrade mode is on, checks whether the | |
2175 | * specified RR is one level below a TLD we have proven not to | |
2176 | * exist. In such a case we assume that this is a private | |
2177 | * domain, and permit it. | |
2178 | * | |
2179 | * This detects cases like the Fritz!Box router networks. Each | |
2180 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2181 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2182 | * are served by the router itself, while requests for the | |
2183 | * "box" domain will result in NXDOMAIN. | |
2184 | * | |
2185 | * Note that this logic is unable to detect cases where a | |
2186 | * router serves a private DNS zone directly under | |
2187 | * non-existing TLD. In such a case we cannot detect whether | |
2188 | * the TLD is supposed to exist or not, as all requests we | |
2189 | * make for it will be answered by the router's zone, and not | |
2190 | * by the root zone. */ | |
2191 | ||
2192 | assert(t); | |
2193 | ||
2194 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2195 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2196 | ||
2197 | tld = DNS_RESOURCE_KEY_NAME(key); | |
2198 | r = dns_name_parent(&tld); | |
2199 | if (r < 0) | |
2200 | return r; | |
2201 | if (r == 0) | |
2202 | return false; /* Already the root domain */ | |
2203 | ||
2204 | if (!dns_name_is_single_label(tld)) | |
2205 | return false; | |
2206 | ||
2207 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2208 | ||
2209 | if (dt->key->class != key->class) | |
2210 | continue; | |
2211 | ||
2212 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), tld); | |
2213 | if (r < 0) | |
2214 | return r; | |
2215 | if (r == 0) | |
2216 | continue; | |
2217 | ||
2218 | /* We found an auxiliary lookup we did for the TLD. If | |
2219 | * that returned with NXDOMAIN, we know the TLD didn't | |
2220 | * exist, and hence this might be a private zone. */ | |
2221 | ||
2222 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2223 | } | |
2224 | ||
2225 | return false; | |
2226 | } | |
2227 | ||
105e1512 LP |
2228 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
2229 | DnsTransaction *dt; | |
2230 | const char *name; | |
2231 | Iterator i; | |
2232 | int r; | |
56352fe9 LP |
2233 | |
2234 | assert(t); | |
2235 | ||
105e1512 LP |
2236 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2237 | * this negative reply */ | |
56352fe9 | 2238 | |
b652d4a2 | 2239 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2240 | return false; |
56352fe9 | 2241 | |
105e1512 LP |
2242 | if (dns_type_is_pseudo(t->key->type)) |
2243 | return -EINVAL; | |
2244 | ||
8a516214 | 2245 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); |
8e54f5d9 LP |
2246 | if (r < 0) |
2247 | return r; | |
2248 | if (r > 0) | |
2249 | return false; | |
2250 | ||
d33b6cf3 LP |
2251 | r = dns_transaction_in_private_tld(t, t->key); |
2252 | if (r < 0) | |
2253 | return r; | |
2254 | if (r > 0) { | |
2255 | /* The lookup is from a TLD that is proven not to | |
2256 | * exist, and we are in downgrade mode, hence ignore | |
2257 | * that fact that we didn't get any NSEC RRs.*/ | |
2258 | ||
2259 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", dns_transaction_key_string(t)); | |
2260 | return false; | |
2261 | } | |
2262 | ||
105e1512 LP |
2263 | name = DNS_RESOURCE_KEY_NAME(t->key); |
2264 | ||
2265 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
2266 | ||
2267 | /* We got a negative reply for this SOA/NS lookup? If | |
2268 | * so, then we are not at a zone apex, and thus should | |
2269 | * look at the result of the parent SOA lookup. | |
2270 | * | |
2271 | * We got a negative reply for this DS lookup? DS RRs | |
2272 | * are signed when their parent zone is signed, hence | |
2273 | * also check the parent SOA in this case. */ | |
2274 | ||
2275 | r = dns_name_parent(&name); | |
56352fe9 LP |
2276 | if (r < 0) |
2277 | return r; | |
2278 | if (r == 0) | |
105e1512 LP |
2279 | return true; |
2280 | } | |
2281 | ||
2282 | /* For all other RRs we check the SOA on the same level to see | |
2283 | * if it's signed. */ | |
2284 | ||
2285 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2286 | ||
2287 | if (dt->key->class != t->key->class) | |
2288 | continue; | |
2289 | if (dt->key->type != DNS_TYPE_SOA) | |
56352fe9 LP |
2290 | continue; |
2291 | ||
105e1512 | 2292 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), name); |
56352fe9 LP |
2293 | if (r < 0) |
2294 | return r; | |
105e1512 LP |
2295 | if (r == 0) |
2296 | continue; | |
2297 | ||
2298 | return dt->answer_authenticated; | |
56352fe9 LP |
2299 | } |
2300 | ||
105e1512 LP |
2301 | /* If in doubt, require NSEC/NSEC3 */ |
2302 | return true; | |
56352fe9 LP |
2303 | } |
2304 | ||
94aa7071 LP |
2305 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2306 | DnsResourceRecord *rrsig; | |
2307 | bool found = false; | |
2308 | int r; | |
2309 | ||
2310 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2311 | * the specified RRset is authenticated (i.e. has a matching | |
2312 | * DS RR). */ | |
2313 | ||
8a516214 | 2314 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
2315 | if (r < 0) |
2316 | return r; | |
2317 | if (r > 0) | |
2318 | return false; | |
2319 | ||
94aa7071 LP |
2320 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2321 | DnsTransaction *dt; | |
2322 | Iterator i; | |
2323 | ||
2324 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2325 | if (r < 0) | |
2326 | return r; | |
2327 | if (r == 0) | |
2328 | continue; | |
2329 | ||
2330 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2331 | ||
2332 | if (dt->key->class != rr->key->class) | |
2333 | continue; | |
2334 | ||
2335 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2336 | ||
2337 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2338 | if (r < 0) | |
2339 | return r; | |
2340 | if (r == 0) | |
2341 | continue; | |
2342 | ||
2343 | /* OK, we found an auxiliary DNSKEY | |
2344 | * lookup. If that lookup is | |
2345 | * authenticated, report this. */ | |
2346 | ||
2347 | if (dt->answer_authenticated) | |
2348 | return true; | |
2349 | ||
2350 | found = true; | |
2351 | ||
2352 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2353 | ||
2354 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2355 | if (r < 0) | |
2356 | return r; | |
2357 | if (r == 0) | |
2358 | continue; | |
2359 | ||
2360 | /* OK, we found an auxiliary DS | |
2361 | * lookup. If that lookup is | |
2362 | * authenticated and non-zero, we | |
2363 | * won! */ | |
2364 | ||
2365 | if (!dt->answer_authenticated) | |
2366 | return false; | |
2367 | ||
2368 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2369 | } | |
2370 | } | |
2371 | } | |
2372 | ||
2373 | return found ? false : -ENXIO; | |
2374 | } | |
2375 | ||
b652d4a2 LP |
2376 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2377 | assert(t); | |
2378 | assert(rr); | |
2379 | ||
2380 | /* We know that the root domain is signed, hence if it appears | |
2381 | * not to be signed, there's a problem with the DNS server */ | |
2382 | ||
2383 | return rr->key->class == DNS_CLASS_IN && | |
2384 | dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key)); | |
2385 | } | |
2386 | ||
0f87f3e8 LP |
2387 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2388 | DnsResourceRecord *rr; | |
2389 | int r; | |
2390 | ||
2391 | assert(t); | |
2392 | ||
2393 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2394 | * for a key from our trust anchor. Note that we don't care | |
2395 | * whether the DNSKEY can be authenticated or not. It's | |
2396 | * sufficient if it is self-signed. */ | |
2397 | ||
2398 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2399 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2400 | if (r < 0) |
2401 | return r; | |
2402 | } | |
2403 | ||
2404 | return 0; | |
2405 | } | |
2406 | ||
c9c72065 LP |
2407 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2408 | bool changed; | |
2409 | int r; | |
2410 | ||
2411 | assert(t); | |
2412 | ||
2413 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2414 | * our trust anchors database considers revoked. */ | |
2415 | ||
2416 | do { | |
2417 | DnsResourceRecord *rr; | |
2418 | ||
2419 | changed = false; | |
2420 | ||
2421 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2422 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2423 | if (r < 0) | |
2424 | return r; | |
2425 | if (r > 0) { | |
2426 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2427 | if (r < 0) | |
2428 | return r; | |
2429 | ||
2430 | assert(r > 0); | |
2431 | changed = true; | |
2432 | break; | |
2433 | } | |
2434 | } | |
2435 | } while (changed); | |
2436 | ||
2437 | return 0; | |
2438 | } | |
2439 | ||
547973de LP |
2440 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2441 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
0c7bff0a LP |
2442 | enum { |
2443 | PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2444 | PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2445 | PHASE_ALL, /* Phase #3, validate everything else */ | |
2446 | } phase; | |
547973de | 2447 | DnsResourceRecord *rr; |
105e1512 | 2448 | DnsAnswerFlags flags; |
56352fe9 | 2449 | int r; |
547973de LP |
2450 | |
2451 | assert(t); | |
2452 | ||
2453 | /* We have now collected all DS and DNSKEY RRs in | |
2454 | * t->validated_keys, let's see which RRs we can now | |
2455 | * authenticate with that. */ | |
2456 | ||
b652d4a2 | 2457 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
2458 | return 0; |
2459 | ||
2460 | /* Already validated */ | |
019036a4 | 2461 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) |
547973de LP |
2462 | return 0; |
2463 | ||
105e1512 | 2464 | /* Our own stuff needs no validation */ |
547973de | 2465 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { |
019036a4 | 2466 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
547973de LP |
2467 | t->answer_authenticated = true; |
2468 | return 0; | |
2469 | } | |
2470 | ||
105e1512 LP |
2471 | /* Cached stuff is not affected by validation. */ |
2472 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2473 | return 0; | |
2474 | ||
92ec902a | 2475 | if (!dns_transaction_dnssec_supported_full(t)) { |
b652d4a2 LP |
2476 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ |
2477 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
de54e62b | 2478 | log_debug("Not validating response, server lacks DNSSEC support."); |
b652d4a2 LP |
2479 | return 0; |
2480 | } | |
2481 | ||
a5784c49 | 2482 | log_debug("Validating response from transaction %" PRIu16 " (%s).", t->id, dns_transaction_key_string(t)); |
547973de | 2483 | |
c9c72065 LP |
2484 | /* First, see if this response contains any revoked trust |
2485 | * anchors we care about */ | |
0f87f3e8 LP |
2486 | r = dns_transaction_check_revoked_trust_anchors(t); |
2487 | if (r < 0) | |
2488 | return r; | |
2489 | ||
c9c72065 LP |
2490 | /* Second, see if there are DNSKEYs we already know a |
2491 | * validated DS for. */ | |
56352fe9 LP |
2492 | r = dns_transaction_validate_dnskey_by_ds(t); |
2493 | if (r < 0) | |
2494 | return r; | |
547973de | 2495 | |
c9c72065 LP |
2496 | /* Third, remove all DNSKEY and DS RRs again that our trust |
2497 | * anchor says are revoked. After all we might have marked | |
2498 | * some keys revoked above, but they might still be lingering | |
2499 | * in our validated_keys list. */ | |
2500 | r = dns_transaction_invalidate_revoked_keys(t); | |
2501 | if (r < 0) | |
2502 | return r; | |
2503 | ||
0c7bff0a | 2504 | phase = PHASE_DNSKEY; |
547973de | 2505 | for (;;) { |
0c7bff0a | 2506 | bool changed = false, have_nsec = false; |
547973de LP |
2507 | |
2508 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
0c7bff0a | 2509 | DnsResourceRecord *rrsig = NULL; |
547973de LP |
2510 | DnssecResult result; |
2511 | ||
0c7bff0a LP |
2512 | switch (rr->key->type) { |
2513 | ||
2514 | case DNS_TYPE_RRSIG: | |
547973de LP |
2515 | continue; |
2516 | ||
0c7bff0a LP |
2517 | case DNS_TYPE_DNSKEY: |
2518 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2519 | if (phase == PHASE_NSEC) | |
2520 | continue; | |
2521 | break; | |
2522 | ||
2523 | case DNS_TYPE_NSEC: | |
2524 | case DNS_TYPE_NSEC3: | |
2525 | have_nsec = true; | |
2526 | ||
2527 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ | |
2528 | if (phase == PHASE_DNSKEY) | |
2529 | continue; | |
2530 | ||
2531 | break; | |
2532 | ||
2533 | default: | |
2534 | /* We validate all other RRs only in the ALL phases */ | |
2535 | if (phase != PHASE_ALL) | |
2536 | continue; | |
2537 | ||
2538 | break; | |
2539 | } | |
2540 | ||
2541 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); | |
547973de LP |
2542 | if (r < 0) |
2543 | return r; | |
2544 | ||
7b50eb2e | 2545 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
547973de | 2546 | |
56352fe9 | 2547 | if (result == DNSSEC_VALIDATED) { |
547973de | 2548 | |
547973de LP |
2549 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2550 | /* If we just validated a | |
2551 | * DNSKEY RRset, then let's | |
2552 | * add these keys to the set | |
2553 | * of validated keys for this | |
2554 | * transaction. */ | |
2555 | ||
105e1512 | 2556 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
547973de LP |
2557 | if (r < 0) |
2558 | return r; | |
c9c72065 LP |
2559 | |
2560 | /* some of the DNSKEYs we just | |
2561 | * added might already have | |
2562 | * been revoked, remove them | |
2563 | * again in that case. */ | |
2564 | r = dns_transaction_invalidate_revoked_keys(t); | |
2565 | if (r < 0) | |
2566 | return r; | |
547973de LP |
2567 | } |
2568 | ||
105e1512 LP |
2569 | /* Add the validated RRset to the new |
2570 | * list of validated RRsets, and | |
2571 | * remove it from the unvalidated | |
2572 | * RRsets. We mark the RRset as | |
2573 | * authenticated and cacheable. */ | |
2574 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
547973de LP |
2575 | if (r < 0) |
2576 | return r; | |
2577 | ||
a150ff5e LP |
2578 | t->scope->manager->n_dnssec_secure++; |
2579 | ||
56352fe9 | 2580 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2581 | changed = true; |
2582 | break; | |
f3cf586d | 2583 | } |
547973de | 2584 | |
0c7bff0a LP |
2585 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2586 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, we | |
2587 | * cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2588 | if (phase != PHASE_ALL) | |
f3cf586d | 2589 | continue; |
b652d4a2 | 2590 | |
0c7bff0a LP |
2591 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2592 | bool authenticated = false; | |
e926785a | 2593 | const char *source; |
0c7bff0a | 2594 | |
e926785a LP |
2595 | /* This RRset validated, but as a wildcard. This means we need to prove via NSEC/NSEC3 |
2596 | * that no matching non-wildcard RR exists.*/ | |
0c7bff0a | 2597 | |
e926785a | 2598 | /* First step, determine the source of synthesis */ |
97c67192 | 2599 | r = dns_resource_record_source(rrsig, &source); |
0c7bff0a LP |
2600 | if (r < 0) |
2601 | return r; | |
0c7bff0a | 2602 | |
e926785a LP |
2603 | r = dnssec_test_positive_wildcard( |
2604 | validated, | |
2605 | DNS_RESOURCE_KEY_NAME(rr->key), | |
2606 | source, | |
2607 | rrsig->rrsig.signer, | |
2608 | &authenticated); | |
0c7bff0a LP |
2609 | |
2610 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ | |
372dd764 | 2611 | if (r == 0) |
0c7bff0a | 2612 | result = DNSSEC_INVALID; |
372dd764 LP |
2613 | else { |
2614 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2615 | if (r < 0) | |
2616 | return r; | |
0c7bff0a | 2617 | |
372dd764 LP |
2618 | if (authenticated) |
2619 | t->scope->manager->n_dnssec_secure++; | |
2620 | else | |
2621 | t->scope->manager->n_dnssec_insecure++; | |
0c7bff0a | 2622 | |
372dd764 LP |
2623 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2624 | changed = true; | |
2625 | break; | |
2626 | } | |
0c7bff0a LP |
2627 | } |
2628 | ||
f3cf586d LP |
2629 | if (result == DNSSEC_NO_SIGNATURE) { |
2630 | r = dns_transaction_requires_rrsig(t, rr); | |
2631 | if (r < 0) | |
2632 | return r; | |
2633 | if (r == 0) { | |
2634 | /* Data does not require signing. In that case, just copy it over, | |
2635 | * but remember that this is by no means authenticated.*/ | |
2636 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
b652d4a2 LP |
2637 | if (r < 0) |
2638 | return r; | |
b652d4a2 | 2639 | |
f3cf586d LP |
2640 | t->scope->manager->n_dnssec_insecure++; |
2641 | changed = true; | |
2642 | break; | |
2643 | } | |
b652d4a2 | 2644 | |
f3cf586d LP |
2645 | r = dns_transaction_known_signed(t, rr); |
2646 | if (r < 0) | |
2647 | return r; | |
2648 | if (r > 0) { | |
2649 | /* This is an RR we know has to be signed. If it isn't this means | |
2650 | * the server is not attaching RRSIGs, hence complain. */ | |
d33b6cf3 | 2651 | |
de54e62b | 2652 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
d33b6cf3 | 2653 | |
f3cf586d | 2654 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
d33b6cf3 | 2655 | |
f3cf586d | 2656 | /* Downgrading is OK? If so, just consider the information unsigned */ |
d33b6cf3 LP |
2657 | |
2658 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2659 | if (r < 0) | |
2660 | return r; | |
2661 | ||
2662 | t->scope->manager->n_dnssec_insecure++; | |
2663 | changed = true; | |
2664 | break; | |
2665 | } | |
f3cf586d LP |
2666 | |
2667 | /* Otherwise, fail */ | |
2668 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2669 | return 0; | |
94aa7071 LP |
2670 | } |
2671 | ||
f3cf586d LP |
2672 | r = dns_transaction_in_private_tld(t, rr->key); |
2673 | if (r < 0) | |
2674 | return r; | |
2675 | if (r > 0) { | |
2676 | _cleanup_free_ char *s = NULL; | |
94aa7071 | 2677 | |
f3cf586d LP |
2678 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2679 | * mode, hence ignore the fact that this was not signed. */ | |
94aa7071 | 2680 | |
f3cf586d LP |
2681 | (void) dns_resource_key_to_string(rr->key, &s); |
2682 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", strna(s ? strstrip(s) : NULL)); | |
94aa7071 | 2683 | |
f3cf586d LP |
2684 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); |
2685 | if (r < 0) | |
2686 | return r; | |
a150ff5e | 2687 | |
f3cf586d LP |
2688 | t->scope->manager->n_dnssec_insecure++; |
2689 | changed = true; | |
2690 | break; | |
105e1512 | 2691 | } |
f3cf586d | 2692 | } |
105e1512 | 2693 | |
f3cf586d LP |
2694 | if (IN_SET(result, |
2695 | DNSSEC_MISSING_KEY, | |
2696 | DNSSEC_SIGNATURE_EXPIRED, | |
2697 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
a150ff5e | 2698 | |
f3cf586d LP |
2699 | r = dns_transaction_dnskey_authenticated(t, rr); |
2700 | if (r < 0 && r != -ENXIO) | |
547973de | 2701 | return r; |
f3cf586d LP |
2702 | if (r == 0) { |
2703 | /* The DNSKEY transaction was not authenticated, this means there's | |
2704 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
2705 | ||
2706 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2707 | if (r < 0) | |
2708 | return r; | |
2709 | ||
2710 | t->scope->manager->n_dnssec_insecure++; | |
2711 | changed = true; | |
2712 | break; | |
547973de | 2713 | } |
f3cf586d | 2714 | } |
547973de | 2715 | |
f3cf586d LP |
2716 | if (IN_SET(result, |
2717 | DNSSEC_INVALID, | |
2718 | DNSSEC_SIGNATURE_EXPIRED, | |
2719 | DNSSEC_NO_SIGNATURE)) | |
2720 | t->scope->manager->n_dnssec_bogus++; | |
2721 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2722 | t->scope->manager->n_dnssec_indeterminate++; | |
547973de | 2723 | |
f3cf586d LP |
2724 | r = dns_transaction_is_primary_response(t, rr); |
2725 | if (r < 0) | |
2726 | return r; | |
2727 | if (r > 0) { | |
43e6779a LP |
2728 | |
2729 | /* Look for a matching DNAME for this CNAME */ | |
2730 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2731 | if (r < 0) | |
2732 | return r; | |
2733 | if (r == 0) { | |
2734 | /* Also look among the stuff we already validated */ | |
2735 | r = dns_answer_has_dname_for_cname(validated, rr); | |
2736 | if (r < 0) | |
2737 | return r; | |
2738 | } | |
2739 | ||
2740 | if (r == 0) { | |
2741 | /* This is a primary response to our question, and it failed validation. That's | |
2742 | * fatal. */ | |
2743 | t->answer_dnssec_result = result; | |
2744 | return 0; | |
2745 | } | |
2746 | ||
2747 | /* This is a primary response, but we do have a DNAME RR in the RR that can replay this | |
2748 | * CNAME, hence rely on that, and we can remove the CNAME in favour of it. */ | |
547973de | 2749 | } |
f3cf586d | 2750 | |
43e6779a | 2751 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
f3cf586d LP |
2752 | r = dns_answer_remove_by_key(&t->answer, rr->key); |
2753 | if (r < 0) | |
2754 | return r; | |
2755 | ||
2756 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2757 | changed = true; | |
2758 | break; | |
547973de LP |
2759 | } |
2760 | ||
0c7bff0a | 2761 | /* Restart the inner loop as long as we managed to achieve something */ |
547973de LP |
2762 | if (changed) |
2763 | continue; | |
2764 | ||
0c7bff0a LP |
2765 | if (phase == PHASE_DNSKEY && have_nsec) { |
2766 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ | |
2767 | phase = PHASE_NSEC; | |
2768 | continue; | |
2769 | } | |
2770 | ||
2771 | if (phase != PHASE_ALL) { | |
2772 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. Note that in this | |
2773 | * third phase we start to remove RRs we couldn't validate. */ | |
2774 | phase = PHASE_ALL; | |
56352fe9 | 2775 | continue; |
547973de LP |
2776 | } |
2777 | ||
56352fe9 | 2778 | /* We're done */ |
547973de LP |
2779 | break; |
2780 | } | |
2781 | ||
2782 | dns_answer_unref(t->answer); | |
2783 | t->answer = validated; | |
2784 | validated = NULL; | |
2785 | ||
72667f08 LP |
2786 | /* At this point the answer only contains validated |
2787 | * RRsets. Now, let's see if it actually answers the question | |
2788 | * we asked. If so, great! If it doesn't, then see if | |
2789 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2790 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2791 | if (r > 0) { |
105e1512 LP |
2792 | /* Yes, it answers the question! */ |
2793 | ||
2794 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2795 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2796 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2797 | t->answer_rcode = DNS_RCODE_SUCCESS; |
2798 | t->answer_authenticated = true; | |
2799 | } else { | |
2800 | /* The answer is not fully authenticated. */ | |
019036a4 | 2801 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2802 | t->answer_authenticated = false; |
2803 | } | |
2804 | ||
72667f08 LP |
2805 | } else if (r == 0) { |
2806 | DnssecNsecResult nr; | |
ed29bfdc | 2807 | bool authenticated = false; |
72667f08 LP |
2808 | |
2809 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 2810 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
2811 | if (r < 0) |
2812 | return r; | |
2813 | ||
2814 | switch (nr) { | |
2815 | ||
2816 | case DNSSEC_NSEC_NXDOMAIN: | |
2817 | /* NSEC proves the domain doesn't exist. Very good. */ | |
105e1512 | 2818 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2819 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2820 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 2821 | t->answer_authenticated = authenticated; |
72667f08 LP |
2822 | break; |
2823 | ||
2824 | case DNSSEC_NSEC_NODATA: | |
2825 | /* NSEC proves that there's no data here, very good. */ | |
105e1512 | 2826 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2827 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2828 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 2829 | t->answer_authenticated = authenticated; |
72667f08 LP |
2830 | break; |
2831 | ||
105e1512 LP |
2832 | case DNSSEC_NSEC_OPTOUT: |
2833 | /* NSEC3 says the data might not be signed */ | |
2834 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); | |
019036a4 | 2835 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2836 | t->answer_authenticated = false; |
2837 | break; | |
2838 | ||
72667f08 LP |
2839 | case DNSSEC_NSEC_NO_RR: |
2840 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
2841 | |
2842 | r = dns_transaction_requires_nsec(t); | |
2843 | if (r < 0) | |
2844 | return r; | |
2845 | if (r > 0) | |
019036a4 | 2846 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
105e1512 | 2847 | else { |
019036a4 | 2848 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2849 | t->answer_authenticated = false; |
2850 | } | |
2851 | ||
2852 | break; | |
2853 | ||
2854 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
2855 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 2856 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
72667f08 LP |
2857 | break; |
2858 | ||
2859 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 2860 | case DNSSEC_NSEC_CNAME: |
72667f08 | 2861 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 2862 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
72667f08 LP |
2863 | break; |
2864 | ||
2865 | default: | |
2866 | assert_not_reached("Unexpected NSEC result."); | |
2867 | } | |
2868 | } | |
2869 | ||
547973de LP |
2870 | return 1; |
2871 | } | |
2872 | ||
a5784c49 LP |
2873 | const char *dns_transaction_key_string(DnsTransaction *t) { |
2874 | assert(t); | |
2875 | ||
2876 | if (!t->key_string) { | |
2877 | if (dns_resource_key_to_string(t->key, &t->key_string) < 0) | |
2878 | return "n/a"; | |
2879 | } | |
2880 | ||
2881 | return strstrip(t->key_string); | |
2882 | } | |
2883 | ||
ec2c5e43 LP |
2884 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
2885 | [DNS_TRANSACTION_NULL] = "null", | |
2886 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 2887 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 2888 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
2889 | [DNS_TRANSACTION_SUCCESS] = "success", |
2890 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
2891 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
2892 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
2893 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
2894 | [DNS_TRANSACTION_RESOURCES] = "resources", | |
2895 | [DNS_TRANSACTION_ABORTED] = "aborted", | |
547973de | 2896 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 2897 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 2898 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
ec2c5e43 LP |
2899 | }; |
2900 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
2901 | |
2902 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
2903 | [DNS_TRANSACTION_NETWORK] = "network", | |
2904 | [DNS_TRANSACTION_CACHE] = "cache", | |
2905 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 2906 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
2907 | }; |
2908 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |