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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 | ||
f32f0e57 LP |
46 | static void dns_transaction_close_connection(DnsTransaction *t) { |
47 | assert(t); | |
48 | ||
49 | t->stream = dns_stream_free(t->stream); | |
50 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); | |
51 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
52 | } | |
53 | ||
f535705a | 54 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
55 | assert(t); |
56 | ||
57 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
58 | } |
59 | ||
ec2c5e43 | 60 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 61 | DnsQueryCandidate *c; |
ec2c5e43 | 62 | DnsZoneItem *i; |
547973de | 63 | DnsTransaction *z; |
ec2c5e43 LP |
64 | |
65 | if (!t) | |
66 | return NULL; | |
67 | ||
51e399bc LP |
68 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
69 | ||
f32f0e57 | 70 | dns_transaction_close_connection(t); |
f535705a | 71 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 72 | |
ec2c5e43 | 73 | dns_packet_unref(t->sent); |
c61d2b44 | 74 | dns_transaction_reset_answer(t); |
ec2c5e43 | 75 | |
8300ba21 | 76 | dns_server_unref(t->server); |
ec2c5e43 LP |
77 | |
78 | if (t->scope) { | |
f9ebb22a LP |
79 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
80 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
81 | |
82 | if (t->id != 0) | |
83 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
84 | } | |
85 | ||
547973de | 86 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 87 | set_remove(c->transactions, t); |
547973de | 88 | set_free(t->notify_query_candidates); |
801ad6a6 | 89 | |
547973de | 90 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 91 | i->probe_transaction = NULL; |
547973de LP |
92 | set_free(t->notify_zone_items); |
93 | ||
94 | while ((z = set_steal_first(t->notify_transactions))) | |
95 | set_remove(z->dnssec_transactions, t); | |
96 | set_free(t->notify_transactions); | |
97 | ||
98 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
99 | set_remove(z->notify_transactions, t); | |
100 | dns_transaction_gc(z); | |
101 | } | |
102 | set_free(t->dnssec_transactions); | |
103 | ||
104 | dns_answer_unref(t->validated_keys); | |
97cc656c | 105 | dns_resource_key_unref(t->key); |
a5784c49 | 106 | free(t->key_string); |
97cc656c | 107 | |
ec2c5e43 LP |
108 | free(t); |
109 | return NULL; | |
110 | } | |
111 | ||
112 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
113 | ||
51e399bc | 114 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
115 | assert(t); |
116 | ||
117 | if (t->block_gc > 0) | |
51e399bc | 118 | return true; |
ec2c5e43 | 119 | |
547973de LP |
120 | if (set_isempty(t->notify_query_candidates) && |
121 | set_isempty(t->notify_zone_items) && | |
51e399bc | 122 | set_isempty(t->notify_transactions)) { |
ec2c5e43 | 123 | dns_transaction_free(t); |
51e399bc LP |
124 | return false; |
125 | } | |
126 | ||
127 | return true; | |
ec2c5e43 LP |
128 | } |
129 | ||
f52e61da | 130 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
131 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
132 | int r; | |
133 | ||
134 | assert(ret); | |
135 | assert(s); | |
f52e61da | 136 | assert(key); |
ec2c5e43 | 137 | |
9eae2bf3 | 138 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 139 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 LP |
140 | return -EINVAL; |
141 | ||
142 | /* We only support the IN class */ | |
c463eb78 | 143 | if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) |
9eae2bf3 LP |
144 | return -EOPNOTSUPP; |
145 | ||
d5099efc | 146 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
147 | if (r < 0) |
148 | return r; | |
149 | ||
f9ebb22a | 150 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
151 | if (r < 0) |
152 | return r; | |
153 | ||
ec2c5e43 LP |
154 | t = new0(DnsTransaction, 1); |
155 | if (!t) | |
156 | return -ENOMEM; | |
157 | ||
4667e00a | 158 | t->dns_udp_fd = -1; |
c3bc53e6 | 159 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 160 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 161 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 162 | t->key = dns_resource_key_ref(key); |
ec2c5e43 | 163 | |
da0c630e | 164 | /* Find a fresh, unused transaction id */ |
ec2c5e43 LP |
165 | do |
166 | random_bytes(&t->id, sizeof(t->id)); | |
167 | while (t->id == 0 || | |
168 | hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); | |
169 | ||
170 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
171 | if (r < 0) { | |
172 | t->id = 0; | |
173 | return r; | |
174 | } | |
175 | ||
f9ebb22a | 176 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
177 | if (r < 0) { |
178 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
179 | return r; | |
180 | } | |
181 | ||
f9ebb22a | 182 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
183 | t->scope = s; |
184 | ||
a150ff5e LP |
185 | s->manager->n_transactions_total ++; |
186 | ||
ec2c5e43 LP |
187 | if (ret) |
188 | *ret = t; | |
189 | ||
190 | t = NULL; | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
ec2c5e43 | 195 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 196 | _cleanup_free_ char *pretty = NULL; |
ec2c5e43 | 197 | DnsZoneItem *z; |
ec2c5e43 LP |
198 | |
199 | assert(t); | |
200 | assert(p); | |
201 | ||
202 | if (manager_our_packet(t->scope->manager, p) != 0) | |
203 | return; | |
204 | ||
2fb3034c LP |
205 | in_addr_to_string(p->family, &p->sender, &pretty); |
206 | ||
a5784c49 LP |
207 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
208 | t->id, | |
209 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
210 | dns_protocol_to_string(t->scope->protocol), |
211 | t->scope->link ? t->scope->link->name : "*", | |
2fb3034c LP |
212 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), |
213 | pretty); | |
ec2c5e43 | 214 | |
a4076574 LP |
215 | /* RFC 4795, Section 4.1 says that the peer with the |
216 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
217 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
218 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
219 | return; |
220 | } | |
221 | ||
4d91eec4 | 222 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 223 | |
ec2c5e43 | 224 | t->block_gc++; |
547973de | 225 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
226 | /* First, make sure the zone item drops the reference |
227 | * to us */ | |
228 | dns_zone_item_probe_stop(z); | |
229 | ||
230 | /* Secondly, report this as conflict, so that we might | |
231 | * look for a different hostname */ | |
ec2c5e43 | 232 | dns_zone_item_conflict(z); |
3ef64445 | 233 | } |
ec2c5e43 LP |
234 | t->block_gc--; |
235 | ||
236 | dns_transaction_gc(t); | |
237 | } | |
238 | ||
239 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 240 | DnsQueryCandidate *c; |
ec2c5e43 | 241 | DnsZoneItem *z; |
547973de | 242 | DnsTransaction *d; |
ec2c5e43 LP |
243 | Iterator i; |
244 | ||
245 | assert(t); | |
547973de | 246 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 247 | |
f61dfddb LP |
248 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) |
249 | log_struct(LOG_NOTICE, | |
beef6a5f | 250 | LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_FAILURE), |
f61dfddb LP |
251 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", dns_transaction_key_string(t), dnssec_result_to_string(t->answer_dnssec_result)), |
252 | "DNS_TRANSACTION=%" PRIu16, t->id, | |
253 | "DNS_QUESTION=%s", dns_transaction_key_string(t), | |
254 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), | |
255 | NULL); | |
256 | ||
ec2c5e43 LP |
257 | /* Note that this call might invalidate the query. Callers |
258 | * should hence not attempt to access the query or transaction | |
259 | * after calling this function. */ | |
260 | ||
a5784c49 LP |
261 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
262 | t->id, | |
263 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
264 | dns_protocol_to_string(t->scope->protocol), |
265 | t->scope->link ? t->scope->link->name : "*", | |
266 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), | |
c3bc53e6 | 267 | dns_transaction_state_to_string(state), |
a5784c49 LP |
268 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
269 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
270 | |
271 | t->state = state; | |
272 | ||
f32f0e57 | 273 | dns_transaction_close_connection(t); |
f535705a | 274 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
275 | |
276 | /* Notify all queries that are interested, but make sure the | |
277 | * transaction isn't freed while we are still looking at it */ | |
278 | t->block_gc++; | |
f7014757 | 279 | |
547973de LP |
280 | SET_FOREACH(c, t->notify_query_candidates, i) |
281 | dns_query_candidate_notify(c); | |
282 | SET_FOREACH(z, t->notify_zone_items, i) | |
283 | dns_zone_item_notify(z); | |
ec2c5e43 | 284 | |
f7014757 LP |
285 | if (!set_isempty(t->notify_transactions)) { |
286 | DnsTransaction **nt; | |
287 | unsigned j, n = 0; | |
288 | ||
289 | /* We need to be careful when notifying other | |
290 | * transactions, as that might destroy other | |
291 | * transactions in our list. Hence, in order to be | |
292 | * able to safely iterate through the list of | |
293 | * transactions, take a GC lock on all of them | |
294 | * first. Then, in a second loop, notify them, but | |
295 | * first unlock that specific transaction. */ | |
296 | ||
297 | nt = newa(DnsTransaction*, set_size(t->notify_transactions)); | |
298 | SET_FOREACH(d, t->notify_transactions, i) { | |
299 | nt[n++] = d; | |
300 | d->block_gc++; | |
301 | } | |
302 | ||
303 | assert(n == set_size(t->notify_transactions)); | |
304 | ||
305 | for (j = 0; j < n; j++) { | |
306 | if (set_contains(t->notify_transactions, nt[j])) | |
307 | dns_transaction_notify(nt[j], t); | |
308 | ||
309 | nt[j]->block_gc--; | |
310 | dns_transaction_gc(nt[j]); | |
311 | } | |
312 | } | |
313 | ||
314 | t->block_gc--; | |
ec2c5e43 LP |
315 | dns_transaction_gc(t); |
316 | } | |
317 | ||
519ef046 LP |
318 | static int dns_transaction_pick_server(DnsTransaction *t) { |
319 | DnsServer *server; | |
320 | ||
321 | assert(t); | |
322 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
323 | ||
324 | server = dns_scope_get_dns_server(t->scope); | |
325 | if (!server) | |
326 | return -ESRCH; | |
327 | ||
f4461e56 | 328 | t->current_features = dns_server_possible_feature_level(server); |
519ef046 LP |
329 | |
330 | if (server == t->server) | |
331 | return 0; | |
332 | ||
333 | dns_server_unref(t->server); | |
334 | t->server = dns_server_ref(server); | |
335 | ||
336 | return 1; | |
337 | } | |
338 | ||
ec2c5e43 LP |
339 | static int on_stream_complete(DnsStream *s, int error) { |
340 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
341 | DnsTransaction *t; | |
342 | ||
343 | assert(s); | |
344 | assert(s->transaction); | |
345 | ||
346 | /* Copy the data we care about out of the stream before we | |
347 | * destroy it. */ | |
348 | t = s->transaction; | |
349 | p = dns_packet_ref(s->read_packet); | |
350 | ||
351 | t->stream = dns_stream_free(t->stream); | |
352 | ||
ac720200 LP |
353 | if (IN_SET(error, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE)) { |
354 | dns_transaction_complete(t, DNS_TRANSACTION_CONNECTION_FAILURE); | |
355 | return 0; | |
356 | } | |
357 | ||
ec2c5e43 LP |
358 | if (error != 0) { |
359 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
360 | return 0; | |
361 | } | |
362 | ||
a4076574 | 363 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 364 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
365 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
366 | return 0; | |
367 | } | |
368 | ||
369 | dns_scope_check_conflicts(t->scope, p); | |
370 | ||
ec2c5e43 LP |
371 | t->block_gc++; |
372 | dns_transaction_process_reply(t, p); | |
373 | t->block_gc--; | |
374 | ||
519ef046 LP |
375 | /* If the response wasn't useful, then complete the transition |
376 | * now. After all, we are the worst feature set now with TCP | |
377 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
378 | if (t->state == DNS_TRANSACTION_PENDING) |
379 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
380 | else |
381 | dns_transaction_gc(t); | |
ec2c5e43 LP |
382 | |
383 | return 0; | |
384 | } | |
385 | ||
386 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
387 | _cleanup_close_ int fd = -1; | |
388 | int r; | |
389 | ||
390 | assert(t); | |
391 | ||
519ef046 | 392 | dns_transaction_close_connection(t); |
ec2c5e43 | 393 | |
106784eb | 394 | switch (t->scope->protocol) { |
519ef046 | 395 | |
106784eb | 396 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
397 | r = dns_transaction_pick_server(t); |
398 | if (r < 0) | |
399 | return r; | |
400 | ||
401 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
402 | if (r < 0) | |
403 | return r; | |
404 | ||
405 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 406 | break; |
ec2c5e43 | 407 | |
106784eb | 408 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 409 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 410 | if (t->received) |
519ef046 | 411 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
412 | else { |
413 | union in_addr_union address; | |
a7f7d1bd | 414 | int family = AF_UNSPEC; |
ec2c5e43 LP |
415 | |
416 | /* Otherwise, try to talk to the owner of a | |
417 | * the IP address, in case this is a reverse | |
418 | * PTR lookup */ | |
f52e61da LP |
419 | |
420 | r = dns_name_address(DNS_RESOURCE_KEY_NAME(t->key), &family, &address); | |
ec2c5e43 LP |
421 | if (r < 0) |
422 | return r; | |
423 | if (r == 0) | |
424 | return -EINVAL; | |
9e08a6e0 | 425 | if (family != t->scope->family) |
9318cdd3 | 426 | return -ESRCH; |
ec2c5e43 | 427 | |
519ef046 | 428 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 429 | } |
106784eb DM |
430 | |
431 | break; | |
432 | ||
433 | default: | |
ec2c5e43 | 434 | return -EAFNOSUPPORT; |
106784eb | 435 | } |
ec2c5e43 LP |
436 | |
437 | if (fd < 0) | |
438 | return fd; | |
439 | ||
440 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
441 | if (r < 0) | |
442 | return r; | |
ec2c5e43 LP |
443 | fd = -1; |
444 | ||
445 | r = dns_stream_write_packet(t->stream, t->sent); | |
446 | if (r < 0) { | |
447 | t->stream = dns_stream_free(t->stream); | |
448 | return r; | |
449 | } | |
450 | ||
ec2c5e43 LP |
451 | t->stream->complete = on_stream_complete; |
452 | t->stream->transaction = t; | |
453 | ||
454 | /* The interface index is difficult to determine if we are | |
455 | * connecting to the local host, hence fill this in right away | |
456 | * instead of determining it from the socket */ | |
457 | if (t->scope->link) | |
458 | t->stream->ifindex = t->scope->link->ifindex; | |
459 | ||
519ef046 LP |
460 | dns_transaction_reset_answer(t); |
461 | ||
cbe4216d LP |
462 | t->tried_stream = true; |
463 | ||
ec2c5e43 LP |
464 | return 0; |
465 | } | |
466 | ||
547973de | 467 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
468 | assert(t); |
469 | ||
470 | /* For mDNS we cache whenever we get the packet, rather than | |
471 | * in each transaction. */ | |
472 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
473 | return; | |
474 | ||
475 | /* We never cache if this packet is from the local host, under | |
476 | * the assumption that a locally running DNS server would | |
477 | * cache this anyway, and probably knows better when to flush | |
478 | * the cache then we could. */ | |
479 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
480 | return; | |
481 | ||
547973de LP |
482 | dns_cache_put(&t->scope->cache, |
483 | t->key, | |
484 | t->answer_rcode, | |
485 | t->answer, | |
547973de | 486 | t->answer_authenticated, |
d3760be0 | 487 | t->answer_nsec_ttl, |
547973de LP |
488 | 0, |
489 | t->received->family, | |
490 | &t->received->sender); | |
491 | } | |
492 | ||
105e1512 LP |
493 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
494 | DnsTransaction *dt; | |
495 | Iterator i; | |
496 | ||
497 | assert(t); | |
498 | ||
499 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
500 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
501 | return true; | |
502 | ||
503 | return false; | |
504 | } | |
505 | ||
547973de LP |
506 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
507 | int r; | |
508 | ||
509 | assert(t); | |
510 | ||
511 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
105e1512 | 512 | if (dns_transaction_dnssec_is_live(t)) |
547973de LP |
513 | return; |
514 | ||
515 | /* All our auxiliary DNSSEC transactions are complete now. Try | |
516 | * to validate our RRset now. */ | |
517 | r = dns_transaction_validate_dnssec(t); | |
518 | if (r < 0) { | |
519 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
520 | return; | |
521 | } | |
522 | ||
b652d4a2 LP |
523 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
524 | t->scope->dnssec_mode == DNSSEC_YES) { | |
525 | /* We are not in automatic downgrade mode, and the | |
526 | * server is bad, refuse operation. */ | |
527 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
528 | return; | |
529 | } | |
530 | ||
019036a4 | 531 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
532 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
533 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
534 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
535 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
536 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
537 | return; | |
538 | } | |
539 | ||
540 | dns_transaction_cache_answer(t); | |
541 | ||
542 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
543 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
544 | else | |
3bbdc31d | 545 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
547973de LP |
546 | } |
547 | ||
ec2c5e43 | 548 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 549 | usec_t ts; |
ec2c5e43 LP |
550 | int r; |
551 | ||
552 | assert(t); | |
553 | assert(p); | |
9df3ba6c TG |
554 | assert(t->scope); |
555 | assert(t->scope->manager); | |
ec2c5e43 | 556 | |
5a7e41a3 LP |
557 | if (t->state != DNS_TRANSACTION_PENDING) |
558 | return; | |
559 | ||
ec2c5e43 LP |
560 | /* Note that this call might invalidate the query. Callers |
561 | * should hence not attempt to access the query or transaction | |
562 | * after calling this function. */ | |
563 | ||
b5efcf29 LP |
564 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
565 | ||
106784eb | 566 | switch (t->scope->protocol) { |
b5efcf29 | 567 | |
106784eb | 568 | case DNS_PROTOCOL_LLMNR: |
ec2c5e43 LP |
569 | assert(t->scope->link); |
570 | ||
571 | /* For LLMNR we will not accept any packets from other | |
572 | * interfaces */ | |
573 | ||
574 | if (p->ifindex != t->scope->link->ifindex) | |
575 | return; | |
576 | ||
577 | if (p->family != t->scope->family) | |
578 | return; | |
579 | ||
580 | /* Tentative packets are not full responses but still | |
581 | * useful for identifying uniqueness conflicts during | |
582 | * probing. */ | |
8b757a38 | 583 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
584 | dns_transaction_tentative(t, p); |
585 | return; | |
586 | } | |
106784eb DM |
587 | |
588 | break; | |
589 | ||
4e5bf5e1 DM |
590 | case DNS_PROTOCOL_MDNS: |
591 | assert(t->scope->link); | |
592 | ||
593 | /* For mDNS we will not accept any packets from other interfaces */ | |
594 | if (p->ifindex != t->scope->link->ifindex) | |
595 | return; | |
596 | ||
597 | if (p->family != t->scope->family) | |
598 | return; | |
599 | ||
600 | break; | |
601 | ||
106784eb | 602 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
603 | /* Note that we do not need to verify the |
604 | * addresses/port numbers of incoming traffic, as we | |
605 | * invoked connect() on our UDP socket in which case | |
606 | * the kernel already does the needed verification for | |
607 | * us. */ | |
106784eb DM |
608 | break; |
609 | ||
610 | default: | |
9c56a6f3 | 611 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
612 | } |
613 | ||
ec2c5e43 LP |
614 | if (t->received != p) { |
615 | dns_packet_unref(t->received); | |
616 | t->received = dns_packet_ref(p); | |
617 | } | |
618 | ||
c3bc53e6 LP |
619 | t->answer_source = DNS_TRANSACTION_NETWORK; |
620 | ||
ec2c5e43 LP |
621 | if (p->ipproto == IPPROTO_TCP) { |
622 | if (DNS_PACKET_TC(p)) { | |
623 | /* Truncated via TCP? Somebody must be fucking with us */ | |
624 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
625 | return; | |
626 | } | |
627 | ||
628 | if (DNS_PACKET_ID(p) != t->id) { | |
629 | /* Not the reply to our query? Somebody must be fucking with us */ | |
630 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
631 | return; | |
632 | } | |
633 | } | |
634 | ||
38a03f06 | 635 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
636 | |
637 | switch (t->scope->protocol) { | |
8af5b883 | 638 | |
9df3ba6c TG |
639 | case DNS_PROTOCOL_DNS: |
640 | assert(t->server); | |
641 | ||
4e0b8b17 TG |
642 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
643 | ||
8af5b883 | 644 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 TG |
645 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
646 | ||
647 | dns_server_packet_failed(t->server, t->current_features); | |
648 | ||
649 | r = dns_transaction_go(t); | |
650 | if (r < 0) { | |
651 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
652 | return; | |
653 | } | |
654 | ||
655 | return; | |
656 | } else | |
d74fb368 | 657 | dns_server_packet_received(t->server, t->current_features, ts - t->start_usec, p->size); |
9df3ba6c TG |
658 | |
659 | break; | |
8af5b883 | 660 | |
9df3ba6c TG |
661 | case DNS_PROTOCOL_LLMNR: |
662 | case DNS_PROTOCOL_MDNS: | |
663 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 664 | break; |
8af5b883 | 665 | |
9df3ba6c | 666 | default: |
8af5b883 | 667 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
668 | } |
669 | ||
ec2c5e43 | 670 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
671 | |
672 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
673 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
674 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
675 | return; | |
676 | } | |
677 | ||
ec2c5e43 LP |
678 | /* Response was truncated, let's try again with good old TCP */ |
679 | r = dns_transaction_open_tcp(t); | |
680 | if (r == -ESRCH) { | |
681 | /* No servers found? Damn! */ | |
682 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
683 | return; | |
684 | } | |
685 | if (r < 0) { | |
8af5b883 | 686 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 LP |
687 | * we immediately give up */ |
688 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { | |
689 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
690 | return; | |
691 | } | |
692 | ||
693 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
519ef046 | 694 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
695 | |
696 | r = dns_transaction_go(t); | |
697 | if (r < 0) { | |
698 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
699 | return; | |
700 | } | |
ec2c5e43 | 701 | } |
2a6658ef LP |
702 | |
703 | return; | |
ec2c5e43 LP |
704 | } |
705 | ||
8af5b883 | 706 | /* Parse message, if it isn't parsed yet. */ |
ec2c5e43 LP |
707 | r = dns_packet_extract(p); |
708 | if (r < 0) { | |
709 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
710 | return; | |
711 | } | |
712 | ||
b5efcf29 LP |
713 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { |
714 | ||
547493c5 | 715 | /* Only consider responses with equivalent query section to the request */ |
8af5b883 LP |
716 | r = dns_packet_is_reply_for(p, t->key); |
717 | if (r < 0) { | |
718 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
719 | return; | |
720 | } | |
721 | if (r == 0) { | |
547493c5 DM |
722 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
723 | return; | |
724 | } | |
29815b6c | 725 | |
547493c5 DM |
726 | /* Install the answer as answer to the transaction */ |
727 | dns_answer_unref(t->answer); | |
728 | t->answer = dns_answer_ref(p->answer); | |
729 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 730 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 731 | t->answer_authenticated = false; |
79e24931 | 732 | |
51e399bc LP |
733 | /* Block GC while starting requests for additional DNSSEC RRs */ |
734 | t->block_gc++; | |
547973de | 735 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
736 | t->block_gc--; |
737 | ||
738 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
739 | if (!dns_transaction_gc(t)) | |
740 | return; | |
741 | ||
742 | /* Requesting additional keys might have resulted in | |
743 | * this transaction to fail, since the auxiliary | |
744 | * request failed for some reason. If so, we are not | |
745 | * in pending state anymore, and we should exit | |
746 | * quickly. */ | |
747 | if (t->state != DNS_TRANSACTION_PENDING) | |
748 | return; | |
547973de LP |
749 | if (r < 0) { |
750 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
751 | return; | |
752 | } | |
753 | if (r > 0) { | |
754 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
755 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
756 | dns_transaction_close_connection(t); |
757 | dns_transaction_stop_timeout(t); | |
547973de LP |
758 | return; |
759 | } | |
547493c5 | 760 | } |
ec2c5e43 | 761 | |
547973de | 762 | dns_transaction_process_dnssec(t); |
ec2c5e43 LP |
763 | } |
764 | ||
c19ffd9f TG |
765 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
766 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
767 | DnsTransaction *t = userdata; | |
768 | int r; | |
769 | ||
770 | assert(t); | |
771 | assert(t->scope); | |
772 | ||
773 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
774 | if (r <= 0) | |
775 | return r; | |
776 | ||
777 | if (dns_packet_validate_reply(p) > 0 && | |
9df3ba6c | 778 | DNS_PACKET_ID(p) == t->id) |
c19ffd9f | 779 | dns_transaction_process_reply(t, p); |
9df3ba6c | 780 | else |
2c6bf498 | 781 | log_debug("Invalid DNS UDP packet, ignoring."); |
c19ffd9f TG |
782 | |
783 | return 0; | |
784 | } | |
785 | ||
49cce12d | 786 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
787 | int r; |
788 | ||
789 | assert(t); | |
c19ffd9f | 790 | |
519ef046 | 791 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 792 | |
519ef046 | 793 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
794 | if (r < 0) |
795 | return r; | |
c19ffd9f | 796 | |
519ef046 LP |
797 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_UDP) |
798 | return -EAGAIN; | |
799 | ||
800 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ | |
801 | int fd; | |
802 | ||
803 | dns_transaction_close_connection(t); | |
c19ffd9f | 804 | |
519ef046 LP |
805 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
806 | if (fd < 0) | |
807 | return fd; | |
808 | ||
809 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
810 | if (r < 0) { | |
811 | safe_close(fd); | |
812 | return r; | |
813 | } | |
814 | ||
815 | t->dns_udp_fd = fd; | |
816 | } | |
817 | ||
818 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
819 | if (r < 0) | |
820 | return r; | |
821 | } else | |
822 | dns_transaction_close_connection(t); | |
823 | ||
824 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
825 | if (r < 0) |
826 | return r; | |
c19ffd9f | 827 | |
519ef046 | 828 | dns_transaction_reset_answer(t); |
be808ea0 | 829 | |
471d40d9 | 830 | return 0; |
c19ffd9f TG |
831 | } |
832 | ||
ec2c5e43 LP |
833 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
834 | DnsTransaction *t = userdata; | |
835 | int r; | |
836 | ||
837 | assert(s); | |
838 | assert(t); | |
839 | ||
ef7ce6df DM |
840 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
841 | /* Timeout reached? Increase the timeout for the server used */ | |
842 | switch (t->scope->protocol) { | |
49cce12d | 843 | |
ef7ce6df DM |
844 | case DNS_PROTOCOL_DNS: |
845 | assert(t->server); | |
ef7ce6df | 846 | dns_server_packet_lost(t->server, t->current_features, usec - t->start_usec); |
ef7ce6df | 847 | break; |
49cce12d | 848 | |
ef7ce6df DM |
849 | case DNS_PROTOCOL_LLMNR: |
850 | case DNS_PROTOCOL_MDNS: | |
851 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 852 | break; |
49cce12d | 853 | |
ef7ce6df DM |
854 | default: |
855 | assert_not_reached("Invalid DNS protocol."); | |
856 | } | |
857 | ||
858 | if (t->initial_jitter_scheduled) | |
859 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
860 | } |
861 | ||
423659ab LP |
862 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
863 | ||
be808ea0 | 864 | /* ...and try again with a new server */ |
519ef046 | 865 | dns_scope_next_dns_server(t->scope); |
be808ea0 | 866 | |
ec2c5e43 LP |
867 | r = dns_transaction_go(t); |
868 | if (r < 0) | |
869 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
870 | ||
871 | return 0; | |
872 | } | |
873 | ||
9df3ba6c TG |
874 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
875 | assert(t); | |
876 | assert(t->scope); | |
877 | ||
878 | switch (t->scope->protocol) { | |
49cce12d | 879 | |
9df3ba6c TG |
880 | case DNS_PROTOCOL_DNS: |
881 | assert(t->server); | |
9df3ba6c | 882 | return t->server->resend_timeout; |
49cce12d | 883 | |
9df3ba6c | 884 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
885 | assert(t->n_attempts > 0); |
886 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 887 | |
11a27c2e | 888 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 889 | return t->scope->resend_timeout; |
49cce12d | 890 | |
9df3ba6c TG |
891 | default: |
892 | assert_not_reached("Invalid DNS protocol."); | |
893 | } | |
894 | } | |
895 | ||
c842ff24 | 896 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
897 | int r; |
898 | ||
899 | assert(t); | |
900 | ||
f535705a | 901 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 902 | |
ec2c5e43 LP |
903 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
904 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
905 | return 0; | |
906 | } | |
907 | ||
cbe4216d | 908 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
909 | /* If we already tried via a stream, then we don't |
910 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
911 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
912 | return 0; | |
913 | } | |
914 | ||
915 | t->n_attempts++; | |
9df3ba6c | 916 | t->start_usec = ts; |
c61d2b44 LP |
917 | |
918 | dns_transaction_reset_answer(t); | |
ec2c5e43 | 919 | |
0d2cd476 LP |
920 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
921 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 922 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
923 | if (r < 0) |
924 | return r; | |
925 | if (r > 0) { | |
926 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
927 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 928 | t->answer_authenticated = true; |
0d2cd476 LP |
929 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
930 | return 0; | |
931 | } | |
b2b796b8 LP |
932 | |
933 | if (dns_name_is_root(DNS_RESOURCE_KEY_NAME(t->key)) && | |
934 | t->key->type == DNS_TYPE_DS) { | |
935 | ||
936 | /* Hmm, this is a request for the root DS? A | |
937 | * DS RR doesn't exist in the root zone, and | |
938 | * if our trust anchor didn't know it either, | |
939 | * this means we cannot do any DNSSEC logic | |
940 | * anymore. */ | |
941 | ||
1ed8c0fb | 942 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
943 | /* We are in downgrade mode. In this |
944 | * case, synthesize an unsigned empty | |
945 | * response, so that the any lookup | |
946 | * depending on this one can continue | |
947 | * assuming there was no DS, and hence | |
948 | * the root zone was unsigned. */ | |
949 | ||
950 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
951 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
952 | t->answer_authenticated = false; | |
953 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
954 | } else | |
955 | /* If we are not in downgrade mode, | |
956 | * then fail the lookup, because we | |
957 | * cannot reasonably answer it. There | |
958 | * might be DS RRs, but we don't know | |
959 | * them, and the DNS server won't tell | |
960 | * them to us (and even if it would, | |
961 | * we couldn't validate it and trust | |
962 | * it). */ | |
963 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); | |
964 | ||
965 | return 0; | |
966 | } | |
0d2cd476 LP |
967 | } |
968 | ||
969 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 970 | * for probing or verifying a zone item. */ |
547973de | 971 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 972 | |
ae6a4bbf | 973 | r = dns_zone_lookup(&t->scope->zone, t->key, &t->answer, NULL, NULL); |
d746bb3e LP |
974 | if (r < 0) |
975 | return r; | |
976 | if (r > 0) { | |
ae6a4bbf | 977 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 978 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 979 | t->answer_authenticated = true; |
d746bb3e LP |
980 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
981 | return 0; | |
982 | } | |
983 | } | |
984 | ||
4d926a69 LP |
985 | /* Check the cache, but only if this transaction is not used |
986 | * for probing or verifying a zone item. */ | |
547973de | 987 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 988 | |
4d926a69 LP |
989 | /* Before trying the cache, let's make sure we figured out a |
990 | * server to use. Should this cause a change of server this | |
991 | * might flush the cache. */ | |
992 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 993 | |
4d926a69 LP |
994 | /* Let's then prune all outdated entries */ |
995 | dns_cache_prune(&t->scope->cache); | |
996 | ||
931851e8 | 997 | r = dns_cache_lookup(&t->scope->cache, t->key, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
998 | if (r < 0) |
999 | return r; | |
1000 | if (r > 0) { | |
c3bc53e6 | 1001 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1002 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1003 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1004 | else | |
3bbdc31d | 1005 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1006 | return 0; |
1007 | } | |
ec2c5e43 LP |
1008 | } |
1009 | ||
1effe965 DM |
1010 | return 1; |
1011 | } | |
1012 | ||
0afa57e2 DM |
1013 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1014 | ||
1015 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1016 | bool add_known_answers = false; |
0afa57e2 DM |
1017 | DnsTransaction *other; |
1018 | unsigned qdcount; | |
1019 | usec_t ts; | |
1020 | int r; | |
1021 | ||
1022 | assert(t); | |
1023 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1024 | ||
e5abebab | 1025 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1026 | t->sent = dns_packet_unref(t->sent); |
1027 | ||
1028 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1029 | if (r < 0) | |
1030 | return r; | |
1031 | ||
1032 | r = dns_packet_append_key(p, t->key, NULL); | |
1033 | if (r < 0) | |
1034 | return r; | |
1035 | ||
1036 | qdcount = 1; | |
1037 | ||
7778dfff DM |
1038 | if (dns_key_is_shared(t->key)) |
1039 | add_known_answers = true; | |
1040 | ||
0afa57e2 DM |
1041 | /* |
1042 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1043 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1044 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1045 | */ | |
1046 | ||
1047 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1048 | ||
1049 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1050 | ||
1051 | /* Skip ourselves */ | |
1052 | if (other == t) | |
1053 | continue; | |
1054 | ||
1055 | if (other->state != DNS_TRANSACTION_PENDING) | |
1056 | continue; | |
1057 | ||
1058 | if (other->next_attempt_after > ts) | |
1059 | continue; | |
1060 | ||
1061 | if (qdcount >= UINT16_MAX) | |
1062 | break; | |
1063 | ||
1064 | r = dns_packet_append_key(p, other->key, NULL); | |
1065 | ||
1066 | /* | |
1067 | * If we can't stuff more questions into the packet, just give up. | |
1068 | * One of the 'other' transactions will fire later and take care of the rest. | |
1069 | */ | |
1070 | if (r == -EMSGSIZE) | |
1071 | break; | |
1072 | ||
1073 | if (r < 0) | |
1074 | return r; | |
1075 | ||
c842ff24 | 1076 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1077 | if (r <= 0) |
1078 | continue; | |
1079 | ||
1080 | ts += transaction_get_resend_timeout(other); | |
1081 | ||
1082 | r = sd_event_add_time( | |
1083 | other->scope->manager->event, | |
1084 | &other->timeout_event_source, | |
1085 | clock_boottime_or_monotonic(), | |
1086 | ts, 0, | |
1087 | on_transaction_timeout, other); | |
1088 | if (r < 0) | |
1089 | return r; | |
1090 | ||
1091 | other->state = DNS_TRANSACTION_PENDING; | |
1092 | other->next_attempt_after = ts; | |
1093 | ||
1094 | qdcount ++; | |
7778dfff DM |
1095 | |
1096 | if (dns_key_is_shared(other->key)) | |
1097 | add_known_answers = true; | |
0afa57e2 DM |
1098 | } |
1099 | ||
1100 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1101 | |
7778dfff DM |
1102 | /* Append known answer section if we're asking for any shared record */ |
1103 | if (add_known_answers) { | |
1104 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1105 | if (r < 0) | |
1106 | return r; | |
1107 | } | |
1108 | ||
0afa57e2 DM |
1109 | t->sent = p; |
1110 | p = NULL; | |
1111 | ||
1112 | return 0; | |
1113 | } | |
1114 | ||
1115 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1116 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1117 | int r; | |
1118 | ||
1119 | assert(t); | |
1120 | ||
1121 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1122 | return dns_transaction_make_packet_mdns(t); | |
1123 | ||
1124 | if (t->sent) | |
1125 | return 0; | |
1126 | ||
b652d4a2 | 1127 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1128 | if (r < 0) |
1129 | return r; | |
1130 | ||
1131 | r = dns_scope_good_key(t->scope, t->key); | |
1132 | if (r < 0) | |
1133 | return r; | |
1134 | if (r == 0) | |
1135 | return -EDOM; | |
1136 | ||
1137 | r = dns_packet_append_key(p, t->key, NULL); | |
1138 | if (r < 0) | |
1139 | return r; | |
1140 | ||
1141 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1142 | DNS_PACKET_HEADER(p)->id = t->id; | |
1143 | ||
1144 | t->sent = p; | |
1145 | p = NULL; | |
1146 | ||
1147 | return 0; | |
1148 | } | |
1149 | ||
1effe965 DM |
1150 | int dns_transaction_go(DnsTransaction *t) { |
1151 | usec_t ts; | |
1152 | int r; | |
1153 | ||
1154 | assert(t); | |
1155 | ||
1156 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
547973de | 1157 | |
c842ff24 | 1158 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1159 | if (r <= 0) |
1160 | return r; | |
1161 | ||
a5784c49 LP |
1162 | log_debug("Excercising transaction %" PRIu16 " for <%s> on scope %s on %s/%s.", |
1163 | t->id, | |
1164 | dns_transaction_key_string(t), | |
1165 | dns_protocol_to_string(t->scope->protocol), | |
1166 | t->scope->link ? t->scope->link->name : "*", | |
1167 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); | |
1effe965 | 1168 | |
ef7ce6df | 1169 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1170 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1171 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1172 | usec_t jitter, accuracy; | |
6e068472 LP |
1173 | |
1174 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1175 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1176 | ||
ef7ce6df | 1177 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1178 | |
1179 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1180 | |
1181 | switch (t->scope->protocol) { | |
519ef046 | 1182 | |
ea12bcc7 DM |
1183 | case DNS_PROTOCOL_LLMNR: |
1184 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1185 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1186 | break; | |
519ef046 | 1187 | |
ea12bcc7 DM |
1188 | case DNS_PROTOCOL_MDNS: |
1189 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1190 | jitter += MDNS_JITTER_MIN_USEC; | |
1191 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1192 | break; | |
1193 | default: | |
1194 | assert_not_reached("bad protocol"); | |
1195 | } | |
6e068472 LP |
1196 | |
1197 | r = sd_event_add_time( | |
1198 | t->scope->manager->event, | |
1199 | &t->timeout_event_source, | |
1200 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1201 | ts + jitter, accuracy, |
6e068472 LP |
1202 | on_transaction_timeout, t); |
1203 | if (r < 0) | |
1204 | return r; | |
1205 | ||
1206 | t->n_attempts = 0; | |
a9da14e1 | 1207 | t->next_attempt_after = ts; |
6e068472 LP |
1208 | t->state = DNS_TRANSACTION_PENDING; |
1209 | ||
ea12bcc7 | 1210 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1211 | return 0; |
1212 | } | |
1213 | ||
ec2c5e43 LP |
1214 | /* Otherwise, we need to ask the network */ |
1215 | r = dns_transaction_make_packet(t); | |
1216 | if (r == -EDOM) { | |
1217 | /* Not the right request to make on this network? | |
1218 | * (i.e. an A request made on IPv6 or an AAAA request | |
1219 | * made on IPv4, on LLMNR or mDNS.) */ | |
1220 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1221 | return 0; | |
1222 | } | |
1223 | if (r < 0) | |
1224 | return r; | |
1225 | ||
1226 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
f52e61da LP |
1227 | (dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "in-addr.arpa") > 0 || |
1228 | dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1229 | |
1230 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1231 | * always be made via TCP on LLMNR */ | |
1232 | r = dns_transaction_open_tcp(t); | |
1233 | } else { | |
be808ea0 TG |
1234 | /* Try via UDP, and if that fails due to large size or lack of |
1235 | * support try via TCP */ | |
49cce12d | 1236 | r = dns_transaction_emit_udp(t); |
be808ea0 | 1237 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1238 | r = dns_transaction_open_tcp(t); |
1239 | } | |
be808ea0 | 1240 | |
ec2c5e43 LP |
1241 | if (r == -ESRCH) { |
1242 | /* No servers to send this to? */ | |
1243 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1244 | return 0; | |
8300ba21 | 1245 | } else if (r < 0) { |
13b551ac LP |
1246 | if (t->scope->protocol != DNS_PROTOCOL_DNS) { |
1247 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
1248 | return 0; | |
1249 | } | |
1250 | ||
ec2c5e43 | 1251 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1252 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1253 | |
1254 | return dns_transaction_go(t); | |
1255 | } | |
1256 | ||
a9da14e1 DM |
1257 | ts += transaction_get_resend_timeout(t); |
1258 | ||
9a015429 LP |
1259 | r = sd_event_add_time( |
1260 | t->scope->manager->event, | |
1261 | &t->timeout_event_source, | |
1262 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1263 | ts, 0, |
9a015429 | 1264 | on_transaction_timeout, t); |
ec2c5e43 LP |
1265 | if (r < 0) |
1266 | return r; | |
1267 | ||
1268 | t->state = DNS_TRANSACTION_PENDING; | |
a9da14e1 DM |
1269 | t->next_attempt_after = ts; |
1270 | ||
ec2c5e43 LP |
1271 | return 1; |
1272 | } | |
1273 | ||
f2992dc1 LP |
1274 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1275 | DnsTransaction *n; | |
1276 | Iterator i; | |
1277 | int r; | |
1278 | ||
1279 | assert(t); | |
1280 | assert(aux); | |
1281 | ||
1282 | /* Try to find cyclic dependencies between transaction objects */ | |
1283 | ||
1284 | if (t == aux) | |
1285 | return 1; | |
1286 | ||
1287 | SET_FOREACH(n, aux->notify_transactions, i) { | |
1288 | r = dns_transaction_find_cyclic(t, n); | |
1289 | if (r != 0) | |
1290 | return r; | |
1291 | } | |
1292 | ||
1293 | return r; | |
1294 | } | |
1295 | ||
547973de LP |
1296 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1297 | DnsTransaction *aux; | |
1298 | int r; | |
1299 | ||
1300 | assert(t); | |
1301 | assert(ret); | |
1302 | assert(key); | |
1303 | ||
1304 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1305 | if (!aux) { | |
1306 | r = dns_transaction_new(&aux, t->scope, key); | |
1307 | if (r < 0) | |
1308 | return r; | |
1309 | } else { | |
1310 | if (set_contains(t->dnssec_transactions, aux)) { | |
1311 | *ret = aux; | |
1312 | return 0; | |
1313 | } | |
f2992dc1 LP |
1314 | |
1315 | r = dns_transaction_find_cyclic(t, aux); | |
1316 | if (r < 0) | |
1317 | return r; | |
1318 | if (r > 0) { | |
1319 | log_debug("Detected potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1320 | aux->id, | |
1321 | strna(dns_transaction_key_string(aux)), | |
1322 | t->id, | |
1323 | strna(dns_transaction_key_string(t))); | |
1324 | return -ELOOP; | |
1325 | } | |
547973de LP |
1326 | } |
1327 | ||
1328 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1329 | if (r < 0) | |
1330 | goto gc; | |
1331 | ||
1332 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1333 | if (r < 0) | |
1334 | goto gc; | |
1335 | ||
1336 | r = set_put(t->dnssec_transactions, aux); | |
1337 | if (r < 0) | |
1338 | goto gc; | |
1339 | ||
1340 | r = set_put(aux->notify_transactions, t); | |
1341 | if (r < 0) { | |
1342 | (void) set_remove(t->dnssec_transactions, aux); | |
1343 | goto gc; | |
1344 | } | |
1345 | ||
1346 | *ret = aux; | |
1347 | return 1; | |
1348 | ||
1349 | gc: | |
1350 | dns_transaction_gc(aux); | |
1351 | return r; | |
1352 | } | |
1353 | ||
1354 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1355 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1356 | DnsTransaction *aux; | |
1357 | int r; | |
1358 | ||
1359 | assert(t); | |
1360 | assert(key); | |
1361 | ||
1362 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1363 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1364 | if (r < 0) |
1365 | return r; | |
1366 | if (r > 0) { | |
1367 | r = dns_answer_extend(&t->validated_keys, a); | |
1368 | if (r < 0) | |
1369 | return r; | |
1370 | ||
1371 | return 0; | |
1372 | } | |
1373 | ||
1374 | /* This didn't work, ask for it via the network/cache then. */ | |
1375 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1376 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1377 | return 0; | |
547973de LP |
1378 | if (r < 0) |
1379 | return r; | |
1380 | ||
1381 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1382 | r = dns_transaction_go(aux); | |
1383 | if (r < 0) | |
1384 | return r; | |
1385 | } | |
1386 | ||
f2992dc1 | 1387 | return 1; |
547973de LP |
1388 | } |
1389 | ||
105e1512 LP |
1390 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
1391 | int r; | |
1392 | ||
1393 | assert(t); | |
1394 | ||
1395 | /* Checks whether the answer is positive, i.e. either a direct | |
1396 | * answer to the question, or a CNAME/DNAME for it */ | |
1397 | ||
1398 | r = dns_answer_match_key(t->answer, t->key, flags); | |
1399 | if (r != 0) | |
1400 | return r; | |
1401 | ||
1402 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
1403 | if (r != 0) | |
1404 | return r; | |
1405 | ||
1406 | return false; | |
1407 | } | |
1408 | ||
1409 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { | |
1410 | int r; | |
1411 | ||
1412 | assert(t); | |
1413 | ||
1414 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1415 | * RRs to prove it */ | |
1416 | ||
1417 | r = dns_transaction_has_positive_answer(t, NULL); | |
1418 | if (r < 0) | |
1419 | return r; | |
1420 | if (r > 0) | |
1421 | return false; | |
1422 | ||
8e54f5d9 LP |
1423 | /* Is this key explicitly listed as a negative trust anchor? |
1424 | * If so, it's nothing we need to care about */ | |
1425 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, DNS_RESOURCE_KEY_NAME(t->key)); | |
1426 | if (r < 0) | |
1427 | return r; | |
1428 | if (r > 0) | |
1429 | return false; | |
1430 | ||
105e1512 LP |
1431 | /* The answer does not contain any RRs that match to the |
1432 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1433 | * included. If not, the answer is unsigned. */ | |
1434 | ||
1435 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1436 | if (r < 0) | |
1437 | return r; | |
1438 | if (r > 0) | |
1439 | return false; | |
1440 | ||
1441 | return true; | |
1442 | } | |
1443 | ||
1444 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1445 | int r; | |
1446 | ||
1447 | assert(t); | |
1448 | assert(rr); | |
1449 | ||
1450 | /* Check if the specified RR is the "primary" response, | |
1451 | * i.e. either matches the question precisely or is a | |
1452 | * CNAME/DNAME for it, or is any kind of NSEC/NSEC3 RR */ | |
1453 | ||
1454 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1455 | if (r != 0) | |
1456 | return r; | |
1457 | ||
1458 | r = dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); | |
1459 | if (r != 0) | |
1460 | return r; | |
1461 | ||
1462 | if (rr->key->type == DNS_TYPE_NSEC3) { | |
1463 | const char *p; | |
1464 | ||
1465 | p = DNS_RESOURCE_KEY_NAME(rr->key); | |
1466 | r = dns_name_parent(&p); | |
1467 | if (r < 0) | |
1468 | return r; | |
1469 | if (r > 0) { | |
1470 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), p); | |
1471 | if (r < 0) | |
1472 | return r; | |
1473 | if (r > 0) | |
1474 | return true; | |
1475 | } | |
1476 | } | |
1477 | ||
1478 | return rr->key->type == DNS_TYPE_NSEC; | |
1479 | } | |
1480 | ||
547973de LP |
1481 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1482 | DnsResourceRecord *rr; | |
105e1512 | 1483 | |
547973de LP |
1484 | int r; |
1485 | ||
1486 | assert(t); | |
1487 | ||
105e1512 LP |
1488 | /* |
1489 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1490 | * we can verify signatures or prove that RRs are rightfully | |
1491 | * unsigned. Specifically: | |
1492 | * | |
1493 | * - For RRSIG we get the matching DNSKEY | |
1494 | * - For DNSKEY we get the matching DS | |
1495 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1496 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 LP |
1497 | * - For other unsigned RRs we get the matching SOA RR |
1498 | * - For SOA/NS/DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
1499 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR | |
1500 | */ | |
1501 | ||
b652d4a2 | 1502 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
1503 | return 0; |
1504 | ||
b652d4a2 LP |
1505 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO) |
1506 | return 0; /* Server doesn't do DNSSEC, there's no point in requesting any RRs then. */ | |
1507 | if (t->server && t->server->rrsig_missing) | |
1508 | return 0; /* Server handles DNSSEC requests, but isn't augmenting responses with RRSIGs. No point in trying DNSSEC then. */ | |
1509 | ||
547973de LP |
1510 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1511 | ||
105e1512 LP |
1512 | if (dns_type_is_pseudo(rr->key->type)) |
1513 | continue; | |
1514 | ||
8e54f5d9 LP |
1515 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1516 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1517 | if (r < 0) | |
1518 | return r; | |
1519 | if (r > 0) | |
1520 | continue; | |
1521 | ||
547973de LP |
1522 | switch (rr->key->type) { |
1523 | ||
1524 | case DNS_TYPE_RRSIG: { | |
1525 | /* For each RRSIG we request the matching DNSKEY */ | |
1526 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1527 | ||
1528 | /* If this RRSIG is about a DNSKEY RR and the | |
1529 | * signer is the same as the owner, then we | |
1530 | * already have the DNSKEY, and we don't have | |
1531 | * to look for more. */ | |
1532 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1533 | r = dns_name_equal(rr->rrsig.signer, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1534 | if (r < 0) | |
1535 | return r; | |
1536 | if (r > 0) | |
1537 | continue; | |
1538 | } | |
1539 | ||
105e1512 LP |
1540 | /* If the signer is not a parent of our |
1541 | * original query, then this is about an | |
1542 | * auxiliary RRset, but not anything we asked | |
1543 | * for. In this case we aren't interested, | |
1544 | * because we don't want to request additional | |
1545 | * RRs for stuff we didn't really ask for, and | |
1546 | * also to avoid request loops, where | |
1547 | * additional RRs from one transaction result | |
1548 | * in another transaction whose additonal RRs | |
1549 | * point back to the original transaction, and | |
1550 | * we deadlock. */ | |
1551 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), rr->rrsig.signer); | |
547973de LP |
1552 | if (r < 0) |
1553 | return r; | |
1554 | if (r == 0) | |
1555 | continue; | |
1556 | ||
1557 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1558 | if (!dnskey) | |
1559 | return -ENOMEM; | |
1560 | ||
105e1512 | 1561 | 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 |
1562 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1563 | if (r < 0) | |
1564 | return r; | |
1565 | break; | |
1566 | } | |
1567 | ||
1568 | case DNS_TYPE_DNSKEY: { | |
1569 | /* For each DNSKEY we request the matching DS */ | |
1570 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1571 | ||
105e1512 LP |
1572 | /* If the DNSKEY we are looking at is not for |
1573 | * zone we are interested in, nor any of its | |
1574 | * parents, we aren't interested, and don't | |
1575 | * request it. After all, we don't want to end | |
1576 | * up in request loops, and want to keep | |
1577 | * additional traffic down. */ | |
1578 | ||
1579 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1580 | if (r < 0) | |
1581 | return r; | |
1582 | if (r == 0) | |
1583 | continue; | |
1584 | ||
547973de LP |
1585 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); |
1586 | if (!ds) | |
1587 | return -ENOMEM; | |
1588 | ||
0c857028 | 1589 | 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 |
1590 | r = dns_transaction_request_dnssec_rr(t, ds); |
1591 | if (r < 0) | |
1592 | return r; | |
547973de | 1593 | |
105e1512 LP |
1594 | break; |
1595 | } | |
1596 | ||
105e1512 LP |
1597 | case DNS_TYPE_SOA: |
1598 | case DNS_TYPE_NS: { | |
1599 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1600 | ||
1601 | /* For an unsigned SOA or NS, try to acquire | |
1602 | * the matching DS RR, as we are at a zone cut | |
1603 | * then, and whether a DS exists tells us | |
1604 | * whether the zone is signed. Do so only if | |
1605 | * this RR matches our original question, | |
1606 | * however. */ | |
1607 | ||
1608 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1609 | if (r < 0) | |
1610 | return r; | |
1611 | if (r == 0) | |
1612 | continue; | |
1613 | ||
1614 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1615 | if (r < 0) | |
1616 | return r; | |
1617 | if (r > 0) | |
1618 | continue; | |
1619 | ||
1620 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1621 | if (!ds) | |
1622 | return -ENOMEM; | |
1623 | ||
1624 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); | |
547973de LP |
1625 | r = dns_transaction_request_dnssec_rr(t, ds); |
1626 | if (r < 0) | |
1627 | return r; | |
1628 | ||
1629 | break; | |
105e1512 LP |
1630 | } |
1631 | ||
b63fca62 | 1632 | case DNS_TYPE_DS: |
105e1512 LP |
1633 | case DNS_TYPE_CNAME: |
1634 | case DNS_TYPE_DNAME: { | |
1635 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1636 | const char *name; | |
1637 | ||
1638 | /* CNAMEs and DNAMEs cannot be located at a | |
1639 | * zone apex, hence ask for the parent SOA for | |
1640 | * unsigned CNAME/DNAME RRs, maybe that's the | |
1641 | * apex. But do all that only if this is | |
1642 | * actually a response to our original | |
b63fca62 LP |
1643 | * question. |
1644 | * | |
1645 | * Similar for DS RRs, which are signed when | |
1646 | * the parent SOA is signed. */ | |
105e1512 LP |
1647 | |
1648 | r = dns_transaction_is_primary_response(t, rr); | |
1649 | if (r < 0) | |
1650 | return r; | |
1651 | if (r == 0) | |
1652 | continue; | |
1653 | ||
1654 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1655 | if (r < 0) | |
1656 | return r; | |
1657 | if (r > 0) | |
1658 | continue; | |
1659 | ||
1660 | name = DNS_RESOURCE_KEY_NAME(rr->key); | |
1661 | r = dns_name_parent(&name); | |
1662 | if (r < 0) | |
1663 | return r; | |
1664 | if (r == 0) | |
1665 | continue; | |
1666 | ||
1667 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
1668 | if (!soa) | |
1669 | return -ENOMEM; | |
1670 | ||
b63fca62 | 1671 | 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 |
1672 | r = dns_transaction_request_dnssec_rr(t, soa); |
1673 | if (r < 0) | |
1674 | return r; | |
1675 | ||
1676 | break; | |
1677 | } | |
1678 | ||
1679 | default: { | |
1680 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1681 | ||
b63fca62 LP |
1682 | /* For other unsigned RRsets (including |
1683 | * NSEC/NSEC3!), look for proof the zone is | |
1684 | * unsigned, by requesting the SOA RR of the | |
1685 | * zone. However, do so only if they are | |
1686 | * directly relevant to our original | |
105e1512 LP |
1687 | * question. */ |
1688 | ||
1689 | r = dns_transaction_is_primary_response(t, rr); | |
1690 | if (r < 0) | |
1691 | return r; | |
1692 | if (r == 0) | |
1693 | continue; | |
1694 | ||
1695 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1696 | if (r < 0) | |
1697 | return r; | |
1698 | if (r > 0) | |
1699 | continue; | |
1700 | ||
1701 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1702 | if (!soa) | |
1703 | return -ENOMEM; | |
1704 | ||
db5b0e92 | 1705 | 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 |
1706 | r = dns_transaction_request_dnssec_rr(t, soa); |
1707 | if (r < 0) | |
1708 | return r; | |
1709 | break; | |
547973de LP |
1710 | }} |
1711 | } | |
1712 | ||
105e1512 LP |
1713 | /* Above, we requested everything necessary to validate what |
1714 | * we got. Now, let's request what we need to validate what we | |
1715 | * didn't get... */ | |
1716 | ||
1717 | r = dns_transaction_has_unsigned_negative_answer(t); | |
1718 | if (r < 0) | |
1719 | return r; | |
1720 | if (r > 0) { | |
1721 | const char *name; | |
1722 | ||
1723 | name = DNS_RESOURCE_KEY_NAME(t->key); | |
1724 | ||
1725 | /* If this was a SOA or NS request, then this | |
1726 | * indicates that we are not at a zone apex, hence ask | |
1727 | * the parent name instead. If this was a DS request, | |
1728 | * then it's signed when the parent zone is signed, | |
1729 | * hence ask the parent in that case, too. */ | |
1730 | ||
1731 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
1732 | r = dns_name_parent(&name); | |
1733 | if (r < 0) | |
1734 | return r; | |
1735 | if (r > 0) | |
1736 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1737 | else | |
1738 | name = NULL; | |
1739 | } else | |
1740 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1741 | ||
1742 | if (name) { | |
1743 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1744 | ||
1745 | soa = dns_resource_key_new(t->key->class, DNS_TYPE_SOA, name); | |
1746 | if (!soa) | |
1747 | return -ENOMEM; | |
1748 | ||
1749 | r = dns_transaction_request_dnssec_rr(t, soa); | |
1750 | if (r < 0) | |
1751 | return r; | |
1752 | } | |
1753 | } | |
1754 | ||
1755 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
1756 | } |
1757 | ||
1758 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
1759 | int r; | |
1760 | ||
1761 | assert(t); | |
547973de LP |
1762 | assert(source); |
1763 | ||
105e1512 LP |
1764 | if (!IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) |
1765 | return; | |
1766 | ||
547973de | 1767 | /* Invoked whenever any of our auxiliary DNSSEC transactions |
105e1512 LP |
1768 | completed its work. We copy any RRs from that transaction |
1769 | over into our list of validated keys -- but only if the | |
1770 | answer is authenticated. | |
1771 | ||
1772 | Note that we fail our transaction if the auxiliary | |
1773 | transaction failed, except on NXDOMAIN. This is because | |
1774 | some broken DNS servers (Akamai...) will return NXDOMAIN | |
1775 | for empty non-terminals. */ | |
1776 | ||
6773896e | 1777 | switch (source->state) { |
547973de | 1778 | |
6773896e LP |
1779 | case DNS_TRANSACTION_DNSSEC_FAILED: |
1780 | ||
1781 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(source->answer_dnssec_result)); | |
1782 | t->answer_dnssec_result = source->answer_dnssec_result; /* Copy error code over */ | |
1783 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
1784 | break; | |
1785 | ||
1786 | case DNS_TRANSACTION_RCODE_FAILURE: | |
1787 | ||
1788 | if (source->answer_rcode != DNS_RCODE_NXDOMAIN) { | |
1789 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%i.", source->answer_rcode); | |
105e1512 | 1790 | goto fail; |
547973de | 1791 | } |
547973de | 1792 | |
6773896e LP |
1793 | /* fall-through: NXDOMAIN is good enough for us */ |
1794 | ||
1795 | case DNS_TRANSACTION_SUCCESS: | |
1796 | if (source->answer_authenticated) { | |
1797 | r = dns_answer_extend(&t->validated_keys, source->answer); | |
1798 | if (r < 0) { | |
1799 | log_error_errno(r, "Failed to merge validated DNSSEC key data: %m"); | |
1800 | goto fail; | |
1801 | } | |
1802 | } | |
1803 | ||
1804 | /* If the state is still PENDING, we are still in the loop | |
1805 | * that adds further DNSSEC transactions, hence don't check if | |
1806 | * we are ready yet. If the state is VALIDATING however, we | |
1807 | * should check if we are complete now. */ | |
1808 | if (t->state == DNS_TRANSACTION_VALIDATING) | |
1809 | dns_transaction_process_dnssec(t); | |
1810 | break; | |
1811 | ||
1812 | default: | |
1813 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(source->state)); | |
1814 | goto fail; | |
1815 | } | |
105e1512 LP |
1816 | |
1817 | return; | |
1818 | ||
1819 | fail: | |
019036a4 | 1820 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; |
105e1512 | 1821 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
547973de LP |
1822 | } |
1823 | ||
105e1512 LP |
1824 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
1825 | DnsResourceRecord *rr; | |
1826 | int ifindex, r; | |
1827 | ||
1828 | assert(t); | |
1829 | ||
1830 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
1831 | * RRs from the list of validated keys to the list of | |
1832 | * validated keys. */ | |
1833 | ||
1834 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
1835 | ||
1836 | r = dnssec_verify_dnskey_search(rr, t->validated_keys); | |
1837 | if (r < 0) | |
1838 | return r; | |
1839 | if (r == 0) | |
1840 | continue; | |
1841 | ||
1842 | /* If so, the DNSKEY is validated too. */ | |
1843 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
1844 | if (r < 0) | |
1845 | return r; | |
1846 | } | |
1847 | ||
1848 | return 0; | |
1849 | } | |
1850 | ||
1851 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
1852 | int r; |
1853 | ||
1854 | assert(t); | |
1855 | assert(rr); | |
1856 | ||
105e1512 LP |
1857 | /* Checks if the RR we are looking for must be signed with an |
1858 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 1859 | |
b652d4a2 | 1860 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 1861 | return false; |
56352fe9 | 1862 | |
105e1512 LP |
1863 | if (dns_type_is_pseudo(rr->key->type)) |
1864 | return -EINVAL; | |
56352fe9 | 1865 | |
8e54f5d9 LP |
1866 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, DNS_RESOURCE_KEY_NAME(rr->key)); |
1867 | if (r < 0) | |
1868 | return r; | |
1869 | if (r > 0) | |
1870 | return false; | |
1871 | ||
105e1512 | 1872 | switch (rr->key->type) { |
56352fe9 | 1873 | |
105e1512 LP |
1874 | case DNS_TYPE_RRSIG: |
1875 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
1876 | return false; | |
1877 | ||
1878 | case DNS_TYPE_SOA: | |
1879 | case DNS_TYPE_NS: { | |
1880 | DnsTransaction *dt; | |
1881 | Iterator i; | |
1882 | ||
b63fca62 | 1883 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
1884 | |
1885 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1886 | ||
1887 | if (dt->key->class != rr->key->class) | |
1888 | continue; | |
1889 | if (dt->key->type != DNS_TYPE_DS) | |
1890 | continue; | |
1891 | ||
1892 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1893 | if (r < 0) | |
1894 | return r; | |
1895 | if (r == 0) | |
1896 | continue; | |
1897 | ||
1898 | /* We found a DS transactions for the SOA/NS | |
1899 | * RRs we are looking at. If it discovered signed DS | |
1900 | * RRs, then we need to be signed, too. */ | |
1901 | ||
097a2517 TA |
1902 | if (!dt->answer_authenticated) |
1903 | return false; | |
105e1512 | 1904 | |
097a2517 | 1905 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
1906 | } |
1907 | ||
1908 | /* We found nothing that proves this is safe to leave | |
1909 | * this unauthenticated, hence ask inist on | |
1910 | * authentication. */ | |
1911 | return true; | |
1912 | } | |
1913 | ||
b63fca62 | 1914 | case DNS_TYPE_DS: |
105e1512 LP |
1915 | case DNS_TYPE_CNAME: |
1916 | case DNS_TYPE_DNAME: { | |
1917 | const char *parent = NULL; | |
1918 | DnsTransaction *dt; | |
1919 | Iterator i; | |
1920 | ||
b63fca62 LP |
1921 | /* |
1922 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
1923 | * | |
1924 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
1925 | */ | |
105e1512 LP |
1926 | |
1927 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1928 | ||
1929 | if (dt->key->class != rr->key->class) | |
1930 | continue; | |
1931 | if (dt->key->type != DNS_TYPE_SOA) | |
1932 | continue; | |
1933 | ||
1934 | if (!parent) { | |
1935 | parent = DNS_RESOURCE_KEY_NAME(rr->key); | |
1936 | r = dns_name_parent(&parent); | |
1937 | if (r < 0) | |
1938 | return r; | |
1939 | if (r == 0) { | |
b63fca62 LP |
1940 | if (rr->key->type == DNS_TYPE_DS) |
1941 | return true; | |
1942 | ||
105e1512 LP |
1943 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
1944 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
1945 | return -EBADMSG; | |
1946 | } | |
1947 | } | |
1948 | ||
1949 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), parent); | |
1950 | if (r < 0) | |
1951 | return r; | |
1952 | if (r == 0) | |
1953 | continue; | |
1954 | ||
1955 | return t->answer_authenticated; | |
1956 | } | |
1957 | ||
1958 | return true; | |
1959 | } | |
1960 | ||
1961 | default: { | |
1962 | DnsTransaction *dt; | |
1963 | Iterator i; | |
1964 | ||
b63fca62 | 1965 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
1966 | |
1967 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1968 | ||
1969 | if (dt->key->class != rr->key->class) | |
1970 | continue; | |
1971 | if (dt->key->type != DNS_TYPE_SOA) | |
1972 | continue; | |
1973 | ||
1974 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1975 | if (r < 0) | |
1976 | return r; | |
1977 | if (r == 0) | |
1978 | continue; | |
1979 | ||
1980 | /* We found the transaction that was supposed to find | |
1981 | * the SOA RR for us. It was successful, but found no | |
1982 | * RR for us. This means we are not at a zone cut. In | |
1983 | * this case, we require authentication if the SOA | |
1984 | * lookup was authenticated too. */ | |
1985 | return t->answer_authenticated; | |
1986 | } | |
1987 | ||
1988 | return true; | |
1989 | }} | |
56352fe9 LP |
1990 | } |
1991 | ||
105e1512 LP |
1992 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
1993 | DnsTransaction *dt; | |
1994 | const char *name; | |
1995 | Iterator i; | |
1996 | int r; | |
56352fe9 LP |
1997 | |
1998 | assert(t); | |
1999 | ||
105e1512 LP |
2000 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2001 | * this negative reply */ | |
56352fe9 | 2002 | |
b652d4a2 | 2003 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2004 | return false; |
56352fe9 | 2005 | |
105e1512 LP |
2006 | if (dns_type_is_pseudo(t->key->type)) |
2007 | return -EINVAL; | |
2008 | ||
8e54f5d9 LP |
2009 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, DNS_RESOURCE_KEY_NAME(t->key)); |
2010 | if (r < 0) | |
2011 | return r; | |
2012 | if (r > 0) | |
2013 | return false; | |
2014 | ||
105e1512 LP |
2015 | name = DNS_RESOURCE_KEY_NAME(t->key); |
2016 | ||
2017 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
2018 | ||
2019 | /* We got a negative reply for this SOA/NS lookup? If | |
2020 | * so, then we are not at a zone apex, and thus should | |
2021 | * look at the result of the parent SOA lookup. | |
2022 | * | |
2023 | * We got a negative reply for this DS lookup? DS RRs | |
2024 | * are signed when their parent zone is signed, hence | |
2025 | * also check the parent SOA in this case. */ | |
2026 | ||
2027 | r = dns_name_parent(&name); | |
56352fe9 LP |
2028 | if (r < 0) |
2029 | return r; | |
2030 | if (r == 0) | |
105e1512 LP |
2031 | return true; |
2032 | } | |
2033 | ||
2034 | /* For all other RRs we check the SOA on the same level to see | |
2035 | * if it's signed. */ | |
2036 | ||
2037 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2038 | ||
2039 | if (dt->key->class != t->key->class) | |
2040 | continue; | |
2041 | if (dt->key->type != DNS_TYPE_SOA) | |
56352fe9 LP |
2042 | continue; |
2043 | ||
105e1512 | 2044 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), name); |
56352fe9 LP |
2045 | if (r < 0) |
2046 | return r; | |
105e1512 LP |
2047 | if (r == 0) |
2048 | continue; | |
2049 | ||
2050 | return dt->answer_authenticated; | |
56352fe9 LP |
2051 | } |
2052 | ||
105e1512 LP |
2053 | /* If in doubt, require NSEC/NSEC3 */ |
2054 | return true; | |
56352fe9 LP |
2055 | } |
2056 | ||
94aa7071 LP |
2057 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2058 | DnsResourceRecord *rrsig; | |
2059 | bool found = false; | |
2060 | int r; | |
2061 | ||
2062 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2063 | * the specified RRset is authenticated (i.e. has a matching | |
2064 | * DS RR). */ | |
2065 | ||
8e54f5d9 LP |
2066 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, DNS_RESOURCE_KEY_NAME(rr->key)); |
2067 | if (r < 0) | |
2068 | return r; | |
2069 | if (r > 0) | |
2070 | return false; | |
2071 | ||
94aa7071 LP |
2072 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2073 | DnsTransaction *dt; | |
2074 | Iterator i; | |
2075 | ||
2076 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2077 | if (r < 0) | |
2078 | return r; | |
2079 | if (r == 0) | |
2080 | continue; | |
2081 | ||
2082 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2083 | ||
2084 | if (dt->key->class != rr->key->class) | |
2085 | continue; | |
2086 | ||
2087 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2088 | ||
2089 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2090 | if (r < 0) | |
2091 | return r; | |
2092 | if (r == 0) | |
2093 | continue; | |
2094 | ||
2095 | /* OK, we found an auxiliary DNSKEY | |
2096 | * lookup. If that lookup is | |
2097 | * authenticated, report this. */ | |
2098 | ||
2099 | if (dt->answer_authenticated) | |
2100 | return true; | |
2101 | ||
2102 | found = true; | |
2103 | ||
2104 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2105 | ||
2106 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2107 | if (r < 0) | |
2108 | return r; | |
2109 | if (r == 0) | |
2110 | continue; | |
2111 | ||
2112 | /* OK, we found an auxiliary DS | |
2113 | * lookup. If that lookup is | |
2114 | * authenticated and non-zero, we | |
2115 | * won! */ | |
2116 | ||
2117 | if (!dt->answer_authenticated) | |
2118 | return false; | |
2119 | ||
2120 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2121 | } | |
2122 | } | |
2123 | } | |
2124 | ||
2125 | return found ? false : -ENXIO; | |
2126 | } | |
2127 | ||
b652d4a2 LP |
2128 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2129 | assert(t); | |
2130 | assert(rr); | |
2131 | ||
2132 | /* We know that the root domain is signed, hence if it appears | |
2133 | * not to be signed, there's a problem with the DNS server */ | |
2134 | ||
2135 | return rr->key->class == DNS_CLASS_IN && | |
2136 | dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key)); | |
2137 | } | |
2138 | ||
547973de LP |
2139 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2140 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
56352fe9 | 2141 | bool dnskeys_finalized = false; |
547973de | 2142 | DnsResourceRecord *rr; |
105e1512 | 2143 | DnsAnswerFlags flags; |
56352fe9 | 2144 | int r; |
547973de LP |
2145 | |
2146 | assert(t); | |
2147 | ||
2148 | /* We have now collected all DS and DNSKEY RRs in | |
2149 | * t->validated_keys, let's see which RRs we can now | |
2150 | * authenticate with that. */ | |
2151 | ||
b652d4a2 | 2152 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
2153 | return 0; |
2154 | ||
2155 | /* Already validated */ | |
019036a4 | 2156 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) |
547973de LP |
2157 | return 0; |
2158 | ||
105e1512 | 2159 | /* Our own stuff needs no validation */ |
547973de | 2160 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { |
019036a4 | 2161 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
547973de LP |
2162 | t->answer_authenticated = true; |
2163 | return 0; | |
2164 | } | |
2165 | ||
105e1512 LP |
2166 | /* Cached stuff is not affected by validation. */ |
2167 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2168 | return 0; | |
2169 | ||
b652d4a2 LP |
2170 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO || |
2171 | (t->server && t->server->rrsig_missing)) { | |
2172 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2173 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2174 | return 0; | |
2175 | } | |
2176 | ||
a5784c49 | 2177 | log_debug("Validating response from transaction %" PRIu16 " (%s).", t->id, dns_transaction_key_string(t)); |
547973de LP |
2178 | |
2179 | /* First see if there are DNSKEYs we already known a validated DS for. */ | |
56352fe9 LP |
2180 | r = dns_transaction_validate_dnskey_by_ds(t); |
2181 | if (r < 0) | |
2182 | return r; | |
547973de LP |
2183 | |
2184 | for (;;) { | |
56352fe9 | 2185 | bool changed = false; |
547973de LP |
2186 | |
2187 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
2188 | DnssecResult result; | |
2189 | ||
2190 | if (rr->key->type == DNS_TYPE_RRSIG) | |
2191 | continue; | |
2192 | ||
2193 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result); | |
2194 | if (r < 0) | |
2195 | return r; | |
2196 | ||
7b50eb2e | 2197 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
547973de | 2198 | |
56352fe9 | 2199 | if (result == DNSSEC_VALIDATED) { |
547973de | 2200 | |
547973de LP |
2201 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2202 | /* If we just validated a | |
2203 | * DNSKEY RRset, then let's | |
2204 | * add these keys to the set | |
2205 | * of validated keys for this | |
2206 | * transaction. */ | |
2207 | ||
105e1512 | 2208 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
547973de LP |
2209 | if (r < 0) |
2210 | return r; | |
0c857028 LP |
2211 | |
2212 | /* Maybe warn the user that we | |
2213 | * encountered a revoked | |
2214 | * DNSKEY for a key from our | |
2215 | * trust anchor */ | |
2216 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, t->answer, rr->key); | |
2217 | if (r < 0) | |
2218 | return r; | |
547973de LP |
2219 | } |
2220 | ||
105e1512 LP |
2221 | /* Add the validated RRset to the new |
2222 | * list of validated RRsets, and | |
2223 | * remove it from the unvalidated | |
2224 | * RRsets. We mark the RRset as | |
2225 | * authenticated and cacheable. */ | |
2226 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
547973de LP |
2227 | if (r < 0) |
2228 | return r; | |
2229 | ||
a150ff5e LP |
2230 | t->scope->manager->n_dnssec_secure++; |
2231 | ||
56352fe9 | 2232 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2233 | changed = true; |
2234 | break; | |
2235 | ||
56352fe9 | 2236 | } else if (dnskeys_finalized) { |
94aa7071 | 2237 | |
56352fe9 LP |
2238 | /* If we haven't read all DNSKEYs yet |
2239 | * a negative result of the validation | |
2240 | * is irrelevant, as there might be | |
2241 | * more DNSKEYs coming. */ | |
547973de | 2242 | |
105e1512 LP |
2243 | if (result == DNSSEC_NO_SIGNATURE) { |
2244 | r = dns_transaction_requires_rrsig(t, rr); | |
2245 | if (r < 0) | |
2246 | return r; | |
2247 | if (r == 0) { | |
2248 | /* Data does not require signing. In that case, just copy it over, | |
2249 | * but remember that this is by no means authenticated.*/ | |
2250 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2251 | if (r < 0) | |
2252 | return r; | |
2253 | ||
a150ff5e LP |
2254 | t->scope->manager->n_dnssec_insecure++; |
2255 | ||
105e1512 LP |
2256 | changed = true; |
2257 | break; | |
2258 | } | |
b652d4a2 LP |
2259 | |
2260 | r = dns_transaction_known_signed(t, rr); | |
2261 | if (r < 0) | |
2262 | return r; | |
2263 | if (r > 0) { | |
2264 | /* This is an RR we know has to be signed. If it isn't this means | |
2265 | * the server is not attaching RRSIGs, hence complain. */ | |
2266 | ||
2267 | dns_server_packet_rrsig_missing(t->server); | |
2268 | ||
1ed8c0fb | 2269 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b652d4a2 LP |
2270 | |
2271 | /* Downgrading is OK? If so, just consider the information unsigned */ | |
2272 | ||
2273 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2274 | if (r < 0) | |
2275 | return r; | |
2276 | ||
2277 | t->scope->manager->n_dnssec_insecure++; | |
2278 | changed = true; | |
2279 | break; | |
2280 | } | |
2281 | ||
2282 | /* Otherwise, fail */ | |
2283 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2284 | return 0; | |
2285 | } | |
94aa7071 LP |
2286 | } |
2287 | ||
2288 | if (IN_SET(result, | |
2289 | DNSSEC_MISSING_KEY, | |
2290 | DNSSEC_SIGNATURE_EXPIRED, | |
2291 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
2292 | ||
2293 | r = dns_transaction_dnskey_authenticated(t, rr); | |
2294 | if (r < 0 && r != -ENXIO) | |
2295 | return r; | |
2296 | if (r == 0) { | |
2297 | /* The DNSKEY transaction was not authenticated, this means there's | |
2298 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
2299 | ||
2300 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2301 | if (r < 0) | |
2302 | return r; | |
2303 | ||
a150ff5e LP |
2304 | t->scope->manager->n_dnssec_insecure++; |
2305 | ||
94aa7071 LP |
2306 | changed = true; |
2307 | break; | |
2308 | } | |
105e1512 LP |
2309 | } |
2310 | ||
a150ff5e LP |
2311 | if (IN_SET(result, |
2312 | DNSSEC_INVALID, | |
2313 | DNSSEC_SIGNATURE_EXPIRED, | |
2314 | DNSSEC_NO_SIGNATURE, | |
2315 | DNSSEC_UNSUPPORTED_ALGORITHM)) | |
2316 | t->scope->manager->n_dnssec_bogus++; | |
2317 | else | |
2318 | t->scope->manager->n_dnssec_indeterminate++; | |
2319 | ||
56352fe9 | 2320 | r = dns_transaction_is_primary_response(t, rr); |
547973de LP |
2321 | if (r < 0) |
2322 | return r; | |
2323 | if (r > 0) { | |
56352fe9 LP |
2324 | /* This is a primary response |
2325 | * to our question, and it | |
2326 | * failed validation. That's | |
2327 | * fatal. */ | |
019036a4 | 2328 | t->answer_dnssec_result = result; |
547973de LP |
2329 | return 0; |
2330 | } | |
2331 | ||
56352fe9 LP |
2332 | /* This is just some auxiliary |
2333 | * data. Just remove the RRset and | |
2334 | * continue. */ | |
547973de LP |
2335 | r = dns_answer_remove_by_key(&t->answer, rr->key); |
2336 | if (r < 0) | |
2337 | return r; | |
2338 | ||
56352fe9 | 2339 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2340 | changed = true; |
2341 | break; | |
547973de | 2342 | } |
547973de LP |
2343 | } |
2344 | ||
2345 | if (changed) | |
2346 | continue; | |
2347 | ||
56352fe9 LP |
2348 | if (!dnskeys_finalized) { |
2349 | /* OK, now we know we have added all DNSKEYs | |
2350 | * we possibly could to our validated | |
2351 | * list. Now run the whole thing once more, | |
2352 | * and strip everything we still cannot | |
2353 | * validate. | |
2354 | */ | |
2355 | dnskeys_finalized = true; | |
2356 | continue; | |
547973de LP |
2357 | } |
2358 | ||
56352fe9 | 2359 | /* We're done */ |
547973de LP |
2360 | break; |
2361 | } | |
2362 | ||
2363 | dns_answer_unref(t->answer); | |
2364 | t->answer = validated; | |
2365 | validated = NULL; | |
2366 | ||
72667f08 LP |
2367 | /* At this point the answer only contains validated |
2368 | * RRsets. Now, let's see if it actually answers the question | |
2369 | * we asked. If so, great! If it doesn't, then see if | |
2370 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2371 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2372 | if (r > 0) { |
105e1512 LP |
2373 | /* Yes, it answers the question! */ |
2374 | ||
2375 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2376 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2377 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2378 | t->answer_rcode = DNS_RCODE_SUCCESS; |
2379 | t->answer_authenticated = true; | |
2380 | } else { | |
2381 | /* The answer is not fully authenticated. */ | |
019036a4 | 2382 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2383 | t->answer_authenticated = false; |
2384 | } | |
2385 | ||
72667f08 LP |
2386 | } else if (r == 0) { |
2387 | DnssecNsecResult nr; | |
ed29bfdc | 2388 | bool authenticated = false; |
72667f08 LP |
2389 | |
2390 | /* Bummer! Let's check NSEC/NSEC3 */ | |
d3760be0 | 2391 | r = dnssec_test_nsec(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
2392 | if (r < 0) |
2393 | return r; | |
2394 | ||
2395 | switch (nr) { | |
2396 | ||
2397 | case DNSSEC_NSEC_NXDOMAIN: | |
2398 | /* NSEC proves the domain doesn't exist. Very good. */ | |
105e1512 | 2399 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2400 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2401 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 2402 | t->answer_authenticated = authenticated; |
72667f08 LP |
2403 | break; |
2404 | ||
2405 | case DNSSEC_NSEC_NODATA: | |
2406 | /* NSEC proves that there's no data here, very good. */ | |
105e1512 | 2407 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2408 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2409 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 2410 | t->answer_authenticated = authenticated; |
72667f08 LP |
2411 | break; |
2412 | ||
105e1512 LP |
2413 | case DNSSEC_NSEC_OPTOUT: |
2414 | /* NSEC3 says the data might not be signed */ | |
2415 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); | |
019036a4 | 2416 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2417 | t->answer_authenticated = false; |
2418 | break; | |
2419 | ||
72667f08 LP |
2420 | case DNSSEC_NSEC_NO_RR: |
2421 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
2422 | |
2423 | r = dns_transaction_requires_nsec(t); | |
2424 | if (r < 0) | |
2425 | return r; | |
2426 | if (r > 0) | |
019036a4 | 2427 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
105e1512 | 2428 | else { |
019036a4 | 2429 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2430 | t->answer_authenticated = false; |
2431 | } | |
2432 | ||
2433 | break; | |
2434 | ||
2435 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
2436 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 2437 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
72667f08 LP |
2438 | break; |
2439 | ||
2440 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 2441 | case DNSSEC_NSEC_CNAME: |
72667f08 | 2442 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 2443 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
72667f08 LP |
2444 | break; |
2445 | ||
2446 | default: | |
2447 | assert_not_reached("Unexpected NSEC result."); | |
2448 | } | |
2449 | } | |
2450 | ||
547973de LP |
2451 | return 1; |
2452 | } | |
2453 | ||
a5784c49 LP |
2454 | const char *dns_transaction_key_string(DnsTransaction *t) { |
2455 | assert(t); | |
2456 | ||
2457 | if (!t->key_string) { | |
2458 | if (dns_resource_key_to_string(t->key, &t->key_string) < 0) | |
2459 | return "n/a"; | |
2460 | } | |
2461 | ||
2462 | return strstrip(t->key_string); | |
2463 | } | |
2464 | ||
ec2c5e43 LP |
2465 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
2466 | [DNS_TRANSACTION_NULL] = "null", | |
2467 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 2468 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 2469 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
2470 | [DNS_TRANSACTION_SUCCESS] = "success", |
2471 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
2472 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
2473 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
2474 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
2475 | [DNS_TRANSACTION_RESOURCES] = "resources", | |
ac720200 | 2476 | [DNS_TRANSACTION_CONNECTION_FAILURE] = "connection-failure", |
ec2c5e43 | 2477 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 2478 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 2479 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
ec2c5e43 LP |
2480 | }; |
2481 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
2482 | |
2483 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
2484 | [DNS_TRANSACTION_NETWORK] = "network", | |
2485 | [DNS_TRANSACTION_CACHE] = "cache", | |
2486 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 2487 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
2488 | }; |
2489 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |