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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 | ||
22 | #include "af-list.h" | |
b5efdb8a | 23 | #include "alloc-util.h" |
f52e61da | 24 | #include "dns-domain.h" |
3ffd4af2 LP |
25 | #include "fd-util.h" |
26 | #include "random-util.h" | |
7778dfff | 27 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
28 | #include "resolved-dns-transaction.h" |
29 | #include "resolved-llmnr.h" | |
8b43440b | 30 | #include "string-table.h" |
ec2c5e43 | 31 | |
c61d2b44 LP |
32 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
33 | assert(t); | |
34 | ||
35 | t->received = dns_packet_unref(t->received); | |
36 | t->answer = dns_answer_unref(t->answer); | |
37 | t->answer_rcode = 0; | |
38 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
39 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
40 | t->answer_authenticated = false; | |
41 | } | |
42 | ||
f32f0e57 LP |
43 | static void dns_transaction_close_connection(DnsTransaction *t) { |
44 | assert(t); | |
45 | ||
46 | t->stream = dns_stream_free(t->stream); | |
47 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); | |
48 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
49 | } | |
50 | ||
97cc656c LP |
51 | static void dns_transaction_stop(DnsTransaction *t) { |
52 | assert(t); | |
53 | ||
54 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
55 | t->stream = dns_stream_free(t->stream); | |
56 | ||
57 | /* Note that we do not drop the UDP socket here, as we want to | |
58 | * reuse it to repeat the interaction. */ | |
59 | } | |
60 | ||
ec2c5e43 | 61 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 62 | DnsQueryCandidate *c; |
ec2c5e43 | 63 | DnsZoneItem *i; |
547973de | 64 | DnsTransaction *z; |
ec2c5e43 LP |
65 | |
66 | if (!t) | |
67 | return NULL; | |
68 | ||
f32f0e57 | 69 | dns_transaction_close_connection(t); |
97cc656c | 70 | dns_transaction_stop(t); |
ec2c5e43 | 71 | |
ec2c5e43 | 72 | dns_packet_unref(t->sent); |
c61d2b44 | 73 | dns_transaction_reset_answer(t); |
ec2c5e43 | 74 | |
8300ba21 | 75 | dns_server_unref(t->server); |
ec2c5e43 LP |
76 | |
77 | if (t->scope) { | |
f9ebb22a LP |
78 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
79 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
80 | |
81 | if (t->id != 0) | |
82 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
83 | } | |
84 | ||
547973de | 85 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 86 | set_remove(c->transactions, t); |
547973de | 87 | set_free(t->notify_query_candidates); |
801ad6a6 | 88 | |
547973de | 89 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 90 | i->probe_transaction = NULL; |
547973de LP |
91 | set_free(t->notify_zone_items); |
92 | ||
93 | while ((z = set_steal_first(t->notify_transactions))) | |
94 | set_remove(z->dnssec_transactions, t); | |
95 | set_free(t->notify_transactions); | |
96 | ||
97 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
98 | set_remove(z->notify_transactions, t); | |
99 | dns_transaction_gc(z); | |
100 | } | |
101 | set_free(t->dnssec_transactions); | |
102 | ||
103 | dns_answer_unref(t->validated_keys); | |
97cc656c | 104 | dns_resource_key_unref(t->key); |
a5784c49 | 105 | free(t->key_string); |
97cc656c | 106 | |
ec2c5e43 LP |
107 | free(t); |
108 | return NULL; | |
109 | } | |
110 | ||
111 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
112 | ||
113 | void dns_transaction_gc(DnsTransaction *t) { | |
114 | assert(t); | |
115 | ||
116 | if (t->block_gc > 0) | |
117 | return; | |
118 | ||
547973de LP |
119 | if (set_isempty(t->notify_query_candidates) && |
120 | set_isempty(t->notify_zone_items) && | |
121 | set_isempty(t->notify_transactions)) | |
ec2c5e43 LP |
122 | dns_transaction_free(t); |
123 | } | |
124 | ||
f52e61da | 125 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
126 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
127 | int r; | |
128 | ||
129 | assert(ret); | |
130 | assert(s); | |
f52e61da | 131 | assert(key); |
ec2c5e43 | 132 | |
9eae2bf3 | 133 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 134 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 LP |
135 | return -EINVAL; |
136 | ||
137 | /* We only support the IN class */ | |
c463eb78 | 138 | if (key->class != DNS_CLASS_IN && key->class != DNS_CLASS_ANY) |
9eae2bf3 LP |
139 | return -EOPNOTSUPP; |
140 | ||
d5099efc | 141 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
142 | if (r < 0) |
143 | return r; | |
144 | ||
f9ebb22a | 145 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
146 | if (r < 0) |
147 | return r; | |
148 | ||
ec2c5e43 LP |
149 | t = new0(DnsTransaction, 1); |
150 | if (!t) | |
151 | return -ENOMEM; | |
152 | ||
4667e00a | 153 | t->dns_udp_fd = -1; |
c3bc53e6 | 154 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 155 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
f52e61da | 156 | t->key = dns_resource_key_ref(key); |
ec2c5e43 | 157 | |
da0c630e | 158 | /* Find a fresh, unused transaction id */ |
ec2c5e43 LP |
159 | do |
160 | random_bytes(&t->id, sizeof(t->id)); | |
161 | while (t->id == 0 || | |
162 | hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(t->id))); | |
163 | ||
164 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
165 | if (r < 0) { | |
166 | t->id = 0; | |
167 | return r; | |
168 | } | |
169 | ||
f9ebb22a | 170 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
171 | if (r < 0) { |
172 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
173 | return r; | |
174 | } | |
175 | ||
f9ebb22a | 176 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
177 | t->scope = s; |
178 | ||
a150ff5e LP |
179 | s->manager->n_transactions_total ++; |
180 | ||
ec2c5e43 LP |
181 | if (ret) |
182 | *ret = t; | |
183 | ||
184 | t = NULL; | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
ec2c5e43 | 189 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 190 | _cleanup_free_ char *pretty = NULL; |
ec2c5e43 | 191 | DnsZoneItem *z; |
ec2c5e43 LP |
192 | |
193 | assert(t); | |
194 | assert(p); | |
195 | ||
196 | if (manager_our_packet(t->scope->manager, p) != 0) | |
197 | return; | |
198 | ||
2fb3034c LP |
199 | in_addr_to_string(p->family, &p->sender, &pretty); |
200 | ||
a5784c49 LP |
201 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
202 | t->id, | |
203 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
204 | dns_protocol_to_string(t->scope->protocol), |
205 | t->scope->link ? t->scope->link->name : "*", | |
2fb3034c LP |
206 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), |
207 | pretty); | |
ec2c5e43 | 208 | |
a4076574 LP |
209 | /* RFC 4795, Section 4.1 says that the peer with the |
210 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
211 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
212 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
213 | return; |
214 | } | |
215 | ||
4d91eec4 | 216 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 217 | |
ec2c5e43 | 218 | t->block_gc++; |
547973de | 219 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
220 | /* First, make sure the zone item drops the reference |
221 | * to us */ | |
222 | dns_zone_item_probe_stop(z); | |
223 | ||
224 | /* Secondly, report this as conflict, so that we might | |
225 | * look for a different hostname */ | |
ec2c5e43 | 226 | dns_zone_item_conflict(z); |
3ef64445 | 227 | } |
ec2c5e43 LP |
228 | t->block_gc--; |
229 | ||
230 | dns_transaction_gc(t); | |
231 | } | |
232 | ||
233 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 234 | DnsQueryCandidate *c; |
ec2c5e43 | 235 | DnsZoneItem *z; |
547973de | 236 | DnsTransaction *d; |
ec2c5e43 LP |
237 | Iterator i; |
238 | ||
239 | assert(t); | |
547973de | 240 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 241 | |
f61dfddb LP |
242 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) |
243 | log_struct(LOG_NOTICE, | |
244 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", dns_transaction_key_string(t), dnssec_result_to_string(t->answer_dnssec_result)), | |
245 | "DNS_TRANSACTION=%" PRIu16, t->id, | |
246 | "DNS_QUESTION=%s", dns_transaction_key_string(t), | |
247 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), | |
248 | NULL); | |
249 | ||
ec2c5e43 LP |
250 | /* Note that this call might invalidate the query. Callers |
251 | * should hence not attempt to access the query or transaction | |
252 | * after calling this function. */ | |
253 | ||
a5784c49 LP |
254 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
255 | t->id, | |
256 | dns_transaction_key_string(t), | |
ec2c5e43 LP |
257 | dns_protocol_to_string(t->scope->protocol), |
258 | t->scope->link ? t->scope->link->name : "*", | |
259 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family), | |
c3bc53e6 | 260 | dns_transaction_state_to_string(state), |
a5784c49 LP |
261 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
262 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
263 | |
264 | t->state = state; | |
265 | ||
f32f0e57 | 266 | dns_transaction_close_connection(t); |
ec2c5e43 LP |
267 | dns_transaction_stop(t); |
268 | ||
269 | /* Notify all queries that are interested, but make sure the | |
270 | * transaction isn't freed while we are still looking at it */ | |
271 | t->block_gc++; | |
f7014757 | 272 | |
547973de LP |
273 | SET_FOREACH(c, t->notify_query_candidates, i) |
274 | dns_query_candidate_notify(c); | |
275 | SET_FOREACH(z, t->notify_zone_items, i) | |
276 | dns_zone_item_notify(z); | |
ec2c5e43 | 277 | |
f7014757 LP |
278 | if (!set_isempty(t->notify_transactions)) { |
279 | DnsTransaction **nt; | |
280 | unsigned j, n = 0; | |
281 | ||
282 | /* We need to be careful when notifying other | |
283 | * transactions, as that might destroy other | |
284 | * transactions in our list. Hence, in order to be | |
285 | * able to safely iterate through the list of | |
286 | * transactions, take a GC lock on all of them | |
287 | * first. Then, in a second loop, notify them, but | |
288 | * first unlock that specific transaction. */ | |
289 | ||
290 | nt = newa(DnsTransaction*, set_size(t->notify_transactions)); | |
291 | SET_FOREACH(d, t->notify_transactions, i) { | |
292 | nt[n++] = d; | |
293 | d->block_gc++; | |
294 | } | |
295 | ||
296 | assert(n == set_size(t->notify_transactions)); | |
297 | ||
298 | for (j = 0; j < n; j++) { | |
299 | if (set_contains(t->notify_transactions, nt[j])) | |
300 | dns_transaction_notify(nt[j], t); | |
301 | ||
302 | nt[j]->block_gc--; | |
303 | dns_transaction_gc(nt[j]); | |
304 | } | |
305 | } | |
306 | ||
307 | t->block_gc--; | |
ec2c5e43 LP |
308 | dns_transaction_gc(t); |
309 | } | |
310 | ||
519ef046 LP |
311 | static int dns_transaction_pick_server(DnsTransaction *t) { |
312 | DnsServer *server; | |
313 | ||
314 | assert(t); | |
315 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
316 | ||
317 | server = dns_scope_get_dns_server(t->scope); | |
318 | if (!server) | |
319 | return -ESRCH; | |
320 | ||
f4461e56 | 321 | t->current_features = dns_server_possible_feature_level(server); |
519ef046 LP |
322 | |
323 | if (server == t->server) | |
324 | return 0; | |
325 | ||
326 | dns_server_unref(t->server); | |
327 | t->server = dns_server_ref(server); | |
328 | ||
329 | return 1; | |
330 | } | |
331 | ||
ec2c5e43 LP |
332 | static int on_stream_complete(DnsStream *s, int error) { |
333 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
334 | DnsTransaction *t; | |
335 | ||
336 | assert(s); | |
337 | assert(s->transaction); | |
338 | ||
339 | /* Copy the data we care about out of the stream before we | |
340 | * destroy it. */ | |
341 | t = s->transaction; | |
342 | p = dns_packet_ref(s->read_packet); | |
343 | ||
344 | t->stream = dns_stream_free(t->stream); | |
345 | ||
ac720200 LP |
346 | if (IN_SET(error, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE)) { |
347 | dns_transaction_complete(t, DNS_TRANSACTION_CONNECTION_FAILURE); | |
348 | return 0; | |
349 | } | |
350 | ||
ec2c5e43 LP |
351 | if (error != 0) { |
352 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
353 | return 0; | |
354 | } | |
355 | ||
a4076574 | 356 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 357 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
358 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
359 | return 0; | |
360 | } | |
361 | ||
362 | dns_scope_check_conflicts(t->scope, p); | |
363 | ||
ec2c5e43 LP |
364 | t->block_gc++; |
365 | dns_transaction_process_reply(t, p); | |
366 | t->block_gc--; | |
367 | ||
519ef046 LP |
368 | /* If the response wasn't useful, then complete the transition |
369 | * now. After all, we are the worst feature set now with TCP | |
370 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
371 | if (t->state == DNS_TRANSACTION_PENDING) |
372 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
373 | else |
374 | dns_transaction_gc(t); | |
ec2c5e43 LP |
375 | |
376 | return 0; | |
377 | } | |
378 | ||
379 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
380 | _cleanup_close_ int fd = -1; | |
381 | int r; | |
382 | ||
383 | assert(t); | |
384 | ||
519ef046 | 385 | dns_transaction_close_connection(t); |
ec2c5e43 | 386 | |
106784eb | 387 | switch (t->scope->protocol) { |
519ef046 | 388 | |
106784eb | 389 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
390 | r = dns_transaction_pick_server(t); |
391 | if (r < 0) | |
392 | return r; | |
393 | ||
394 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
395 | if (r < 0) | |
396 | return r; | |
397 | ||
398 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 399 | break; |
ec2c5e43 | 400 | |
106784eb | 401 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 402 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 403 | if (t->received) |
519ef046 | 404 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
405 | else { |
406 | union in_addr_union address; | |
a7f7d1bd | 407 | int family = AF_UNSPEC; |
ec2c5e43 LP |
408 | |
409 | /* Otherwise, try to talk to the owner of a | |
410 | * the IP address, in case this is a reverse | |
411 | * PTR lookup */ | |
f52e61da LP |
412 | |
413 | r = dns_name_address(DNS_RESOURCE_KEY_NAME(t->key), &family, &address); | |
ec2c5e43 LP |
414 | if (r < 0) |
415 | return r; | |
416 | if (r == 0) | |
417 | return -EINVAL; | |
9e08a6e0 | 418 | if (family != t->scope->family) |
9318cdd3 | 419 | return -ESRCH; |
ec2c5e43 | 420 | |
519ef046 | 421 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 422 | } |
106784eb DM |
423 | |
424 | break; | |
425 | ||
426 | default: | |
ec2c5e43 | 427 | return -EAFNOSUPPORT; |
106784eb | 428 | } |
ec2c5e43 LP |
429 | |
430 | if (fd < 0) | |
431 | return fd; | |
432 | ||
433 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
434 | if (r < 0) | |
435 | return r; | |
ec2c5e43 LP |
436 | fd = -1; |
437 | ||
438 | r = dns_stream_write_packet(t->stream, t->sent); | |
439 | if (r < 0) { | |
440 | t->stream = dns_stream_free(t->stream); | |
441 | return r; | |
442 | } | |
443 | ||
ec2c5e43 LP |
444 | t->stream->complete = on_stream_complete; |
445 | t->stream->transaction = t; | |
446 | ||
447 | /* The interface index is difficult to determine if we are | |
448 | * connecting to the local host, hence fill this in right away | |
449 | * instead of determining it from the socket */ | |
450 | if (t->scope->link) | |
451 | t->stream->ifindex = t->scope->link->ifindex; | |
452 | ||
519ef046 LP |
453 | dns_transaction_reset_answer(t); |
454 | ||
cbe4216d LP |
455 | t->tried_stream = true; |
456 | ||
ec2c5e43 LP |
457 | return 0; |
458 | } | |
459 | ||
547973de | 460 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
461 | assert(t); |
462 | ||
463 | /* For mDNS we cache whenever we get the packet, rather than | |
464 | * in each transaction. */ | |
465 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
466 | return; | |
467 | ||
468 | /* We never cache if this packet is from the local host, under | |
469 | * the assumption that a locally running DNS server would | |
470 | * cache this anyway, and probably knows better when to flush | |
471 | * the cache then we could. */ | |
472 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
473 | return; | |
474 | ||
547973de LP |
475 | dns_cache_put(&t->scope->cache, |
476 | t->key, | |
477 | t->answer_rcode, | |
478 | t->answer, | |
547973de LP |
479 | t->answer_authenticated, |
480 | 0, | |
481 | t->received->family, | |
482 | &t->received->sender); | |
483 | } | |
484 | ||
105e1512 LP |
485 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
486 | DnsTransaction *dt; | |
487 | Iterator i; | |
488 | ||
489 | assert(t); | |
490 | ||
491 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
492 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
493 | return true; | |
494 | ||
495 | return false; | |
496 | } | |
497 | ||
547973de LP |
498 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
499 | int r; | |
500 | ||
501 | assert(t); | |
502 | ||
503 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
105e1512 | 504 | if (dns_transaction_dnssec_is_live(t)) |
547973de LP |
505 | return; |
506 | ||
507 | /* All our auxiliary DNSSEC transactions are complete now. Try | |
508 | * to validate our RRset now. */ | |
509 | r = dns_transaction_validate_dnssec(t); | |
510 | if (r < 0) { | |
511 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
512 | return; | |
513 | } | |
514 | ||
b652d4a2 LP |
515 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
516 | t->scope->dnssec_mode == DNSSEC_YES) { | |
517 | /* We are not in automatic downgrade mode, and the | |
518 | * server is bad, refuse operation. */ | |
519 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
520 | return; | |
521 | } | |
522 | ||
019036a4 | 523 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
524 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
525 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
526 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
527 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
528 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
529 | return; | |
530 | } | |
531 | ||
532 | dns_transaction_cache_answer(t); | |
533 | ||
534 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
535 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
536 | else | |
3bbdc31d | 537 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
547973de LP |
538 | } |
539 | ||
ec2c5e43 | 540 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 541 | usec_t ts; |
ec2c5e43 LP |
542 | int r; |
543 | ||
544 | assert(t); | |
545 | assert(p); | |
9df3ba6c TG |
546 | assert(t->scope); |
547 | assert(t->scope->manager); | |
ec2c5e43 | 548 | |
5a7e41a3 LP |
549 | if (t->state != DNS_TRANSACTION_PENDING) |
550 | return; | |
551 | ||
ec2c5e43 LP |
552 | /* Note that this call might invalidate the query. Callers |
553 | * should hence not attempt to access the query or transaction | |
554 | * after calling this function. */ | |
555 | ||
b5efcf29 LP |
556 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
557 | ||
106784eb | 558 | switch (t->scope->protocol) { |
b5efcf29 | 559 | |
106784eb | 560 | case DNS_PROTOCOL_LLMNR: |
ec2c5e43 LP |
561 | assert(t->scope->link); |
562 | ||
563 | /* For LLMNR we will not accept any packets from other | |
564 | * interfaces */ | |
565 | ||
566 | if (p->ifindex != t->scope->link->ifindex) | |
567 | return; | |
568 | ||
569 | if (p->family != t->scope->family) | |
570 | return; | |
571 | ||
572 | /* Tentative packets are not full responses but still | |
573 | * useful for identifying uniqueness conflicts during | |
574 | * probing. */ | |
8b757a38 | 575 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
576 | dns_transaction_tentative(t, p); |
577 | return; | |
578 | } | |
106784eb DM |
579 | |
580 | break; | |
581 | ||
4e5bf5e1 DM |
582 | case DNS_PROTOCOL_MDNS: |
583 | assert(t->scope->link); | |
584 | ||
585 | /* For mDNS we will not accept any packets from other interfaces */ | |
586 | if (p->ifindex != t->scope->link->ifindex) | |
587 | return; | |
588 | ||
589 | if (p->family != t->scope->family) | |
590 | return; | |
591 | ||
592 | break; | |
593 | ||
106784eb DM |
594 | case DNS_PROTOCOL_DNS: |
595 | break; | |
596 | ||
597 | default: | |
9c56a6f3 | 598 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
599 | } |
600 | ||
ec2c5e43 LP |
601 | if (t->received != p) { |
602 | dns_packet_unref(t->received); | |
603 | t->received = dns_packet_ref(p); | |
604 | } | |
605 | ||
c3bc53e6 LP |
606 | t->answer_source = DNS_TRANSACTION_NETWORK; |
607 | ||
ec2c5e43 LP |
608 | if (p->ipproto == IPPROTO_TCP) { |
609 | if (DNS_PACKET_TC(p)) { | |
610 | /* Truncated via TCP? Somebody must be fucking with us */ | |
611 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
612 | return; | |
613 | } | |
614 | ||
615 | if (DNS_PACKET_ID(p) != t->id) { | |
616 | /* Not the reply to our query? Somebody must be fucking with us */ | |
617 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
618 | return; | |
619 | } | |
620 | } | |
621 | ||
38a03f06 | 622 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
623 | |
624 | switch (t->scope->protocol) { | |
8af5b883 | 625 | |
9df3ba6c TG |
626 | case DNS_PROTOCOL_DNS: |
627 | assert(t->server); | |
628 | ||
4e0b8b17 TG |
629 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
630 | ||
8af5b883 | 631 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 TG |
632 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
633 | ||
634 | dns_server_packet_failed(t->server, t->current_features); | |
635 | ||
636 | r = dns_transaction_go(t); | |
637 | if (r < 0) { | |
638 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
639 | return; | |
640 | } | |
641 | ||
642 | return; | |
643 | } else | |
d74fb368 | 644 | dns_server_packet_received(t->server, t->current_features, ts - t->start_usec, p->size); |
9df3ba6c TG |
645 | |
646 | break; | |
8af5b883 | 647 | |
9df3ba6c TG |
648 | case DNS_PROTOCOL_LLMNR: |
649 | case DNS_PROTOCOL_MDNS: | |
650 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 651 | break; |
8af5b883 | 652 | |
9df3ba6c | 653 | default: |
8af5b883 | 654 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
655 | } |
656 | ||
ec2c5e43 | 657 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
658 | |
659 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
660 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
661 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
662 | return; | |
663 | } | |
664 | ||
ec2c5e43 LP |
665 | /* Response was truncated, let's try again with good old TCP */ |
666 | r = dns_transaction_open_tcp(t); | |
667 | if (r == -ESRCH) { | |
668 | /* No servers found? Damn! */ | |
669 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
670 | return; | |
671 | } | |
672 | if (r < 0) { | |
8af5b883 | 673 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 LP |
674 | * we immediately give up */ |
675 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { | |
676 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
677 | return; | |
678 | } | |
679 | ||
680 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
519ef046 | 681 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
682 | |
683 | r = dns_transaction_go(t); | |
684 | if (r < 0) { | |
685 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
686 | return; | |
687 | } | |
ec2c5e43 | 688 | } |
2a6658ef LP |
689 | |
690 | return; | |
ec2c5e43 LP |
691 | } |
692 | ||
8af5b883 | 693 | /* Parse message, if it isn't parsed yet. */ |
ec2c5e43 LP |
694 | r = dns_packet_extract(p); |
695 | if (r < 0) { | |
696 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
697 | return; | |
698 | } | |
699 | ||
b5efcf29 LP |
700 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { |
701 | ||
547493c5 | 702 | /* Only consider responses with equivalent query section to the request */ |
8af5b883 LP |
703 | r = dns_packet_is_reply_for(p, t->key); |
704 | if (r < 0) { | |
705 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
706 | return; | |
707 | } | |
708 | if (r == 0) { | |
547493c5 DM |
709 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
710 | return; | |
711 | } | |
29815b6c | 712 | |
547493c5 DM |
713 | /* Install the answer as answer to the transaction */ |
714 | dns_answer_unref(t->answer); | |
715 | t->answer = dns_answer_ref(p->answer); | |
716 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 717 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 718 | t->answer_authenticated = false; |
79e24931 | 719 | |
547973de LP |
720 | r = dns_transaction_request_dnssec_keys(t); |
721 | if (r < 0) { | |
722 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
723 | return; | |
724 | } | |
725 | if (r > 0) { | |
726 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
727 | t->state = DNS_TRANSACTION_VALIDATING; | |
423659ab | 728 | dns_transaction_stop(t); |
547973de LP |
729 | return; |
730 | } | |
547493c5 | 731 | } |
ec2c5e43 | 732 | |
547973de | 733 | dns_transaction_process_dnssec(t); |
ec2c5e43 LP |
734 | } |
735 | ||
c19ffd9f TG |
736 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
737 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
738 | DnsTransaction *t = userdata; | |
739 | int r; | |
740 | ||
741 | assert(t); | |
742 | assert(t->scope); | |
743 | ||
744 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
745 | if (r <= 0) | |
746 | return r; | |
747 | ||
748 | if (dns_packet_validate_reply(p) > 0 && | |
9df3ba6c | 749 | DNS_PACKET_ID(p) == t->id) |
c19ffd9f | 750 | dns_transaction_process_reply(t, p); |
9df3ba6c | 751 | else |
2c6bf498 | 752 | log_debug("Invalid DNS UDP packet, ignoring."); |
c19ffd9f TG |
753 | |
754 | return 0; | |
755 | } | |
756 | ||
49cce12d | 757 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
758 | int r; |
759 | ||
760 | assert(t); | |
c19ffd9f | 761 | |
519ef046 | 762 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 763 | |
519ef046 | 764 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
765 | if (r < 0) |
766 | return r; | |
c19ffd9f | 767 | |
519ef046 LP |
768 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_UDP) |
769 | return -EAGAIN; | |
770 | ||
771 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ | |
772 | int fd; | |
773 | ||
774 | dns_transaction_close_connection(t); | |
c19ffd9f | 775 | |
519ef046 LP |
776 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
777 | if (fd < 0) | |
778 | return fd; | |
779 | ||
780 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
781 | if (r < 0) { | |
782 | safe_close(fd); | |
783 | return r; | |
784 | } | |
785 | ||
786 | t->dns_udp_fd = fd; | |
787 | } | |
788 | ||
789 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
790 | if (r < 0) | |
791 | return r; | |
792 | } else | |
793 | dns_transaction_close_connection(t); | |
794 | ||
795 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
796 | if (r < 0) |
797 | return r; | |
c19ffd9f | 798 | |
519ef046 | 799 | dns_transaction_reset_answer(t); |
be808ea0 | 800 | |
471d40d9 | 801 | return 0; |
c19ffd9f TG |
802 | } |
803 | ||
ec2c5e43 LP |
804 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
805 | DnsTransaction *t = userdata; | |
806 | int r; | |
807 | ||
808 | assert(s); | |
809 | assert(t); | |
810 | ||
ef7ce6df DM |
811 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
812 | /* Timeout reached? Increase the timeout for the server used */ | |
813 | switch (t->scope->protocol) { | |
49cce12d | 814 | |
ef7ce6df DM |
815 | case DNS_PROTOCOL_DNS: |
816 | assert(t->server); | |
ef7ce6df | 817 | dns_server_packet_lost(t->server, t->current_features, usec - t->start_usec); |
ef7ce6df | 818 | break; |
49cce12d | 819 | |
ef7ce6df DM |
820 | case DNS_PROTOCOL_LLMNR: |
821 | case DNS_PROTOCOL_MDNS: | |
822 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 823 | break; |
49cce12d | 824 | |
ef7ce6df DM |
825 | default: |
826 | assert_not_reached("Invalid DNS protocol."); | |
827 | } | |
828 | ||
829 | if (t->initial_jitter_scheduled) | |
830 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
831 | } |
832 | ||
423659ab LP |
833 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
834 | ||
be808ea0 | 835 | /* ...and try again with a new server */ |
519ef046 | 836 | dns_scope_next_dns_server(t->scope); |
be808ea0 | 837 | |
ec2c5e43 LP |
838 | r = dns_transaction_go(t); |
839 | if (r < 0) | |
840 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
841 | ||
842 | return 0; | |
843 | } | |
844 | ||
9df3ba6c TG |
845 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
846 | assert(t); | |
847 | assert(t->scope); | |
848 | ||
849 | switch (t->scope->protocol) { | |
49cce12d | 850 | |
9df3ba6c TG |
851 | case DNS_PROTOCOL_DNS: |
852 | assert(t->server); | |
9df3ba6c | 853 | return t->server->resend_timeout; |
49cce12d | 854 | |
9df3ba6c | 855 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
856 | assert(t->n_attempts > 0); |
857 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 858 | |
11a27c2e | 859 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 860 | return t->scope->resend_timeout; |
49cce12d | 861 | |
9df3ba6c TG |
862 | default: |
863 | assert_not_reached("Invalid DNS protocol."); | |
864 | } | |
865 | } | |
866 | ||
c842ff24 | 867 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
868 | int r; |
869 | ||
870 | assert(t); | |
871 | ||
ec2c5e43 LP |
872 | dns_transaction_stop(t); |
873 | ||
ec2c5e43 LP |
874 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
875 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
876 | return 0; | |
877 | } | |
878 | ||
cbe4216d | 879 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
880 | /* If we already tried via a stream, then we don't |
881 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
882 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
883 | return 0; | |
884 | } | |
885 | ||
886 | t->n_attempts++; | |
9df3ba6c | 887 | t->start_usec = ts; |
c61d2b44 LP |
888 | |
889 | dns_transaction_reset_answer(t); | |
ec2c5e43 | 890 | |
0d2cd476 LP |
891 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
892 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
893 | r = dns_trust_anchor_lookup(&t->scope->manager->trust_anchor, t->key, &t->answer); | |
894 | if (r < 0) | |
895 | return r; | |
896 | if (r > 0) { | |
897 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
898 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 899 | t->answer_authenticated = true; |
0d2cd476 LP |
900 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
901 | return 0; | |
902 | } | |
903 | } | |
904 | ||
905 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 906 | * for probing or verifying a zone item. */ |
547973de | 907 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 908 | |
ae6a4bbf | 909 | r = dns_zone_lookup(&t->scope->zone, t->key, &t->answer, NULL, NULL); |
d746bb3e LP |
910 | if (r < 0) |
911 | return r; | |
912 | if (r > 0) { | |
ae6a4bbf | 913 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 914 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 915 | t->answer_authenticated = true; |
d746bb3e LP |
916 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
917 | return 0; | |
918 | } | |
919 | } | |
920 | ||
4d926a69 LP |
921 | /* Check the cache, but only if this transaction is not used |
922 | * for probing or verifying a zone item. */ | |
547973de | 923 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 924 | |
4d926a69 LP |
925 | /* Before trying the cache, let's make sure we figured out a |
926 | * server to use. Should this cause a change of server this | |
927 | * might flush the cache. */ | |
928 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 929 | |
4d926a69 LP |
930 | /* Let's then prune all outdated entries */ |
931 | dns_cache_prune(&t->scope->cache); | |
932 | ||
931851e8 | 933 | r = dns_cache_lookup(&t->scope->cache, t->key, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
934 | if (r < 0) |
935 | return r; | |
936 | if (r > 0) { | |
c3bc53e6 | 937 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 938 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
939 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
940 | else | |
3bbdc31d | 941 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
942 | return 0; |
943 | } | |
ec2c5e43 LP |
944 | } |
945 | ||
1effe965 DM |
946 | return 1; |
947 | } | |
948 | ||
0afa57e2 DM |
949 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
950 | ||
951 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 952 | bool add_known_answers = false; |
0afa57e2 DM |
953 | DnsTransaction *other; |
954 | unsigned qdcount; | |
955 | usec_t ts; | |
956 | int r; | |
957 | ||
958 | assert(t); | |
959 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
960 | ||
e5abebab | 961 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
962 | t->sent = dns_packet_unref(t->sent); |
963 | ||
964 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
965 | if (r < 0) | |
966 | return r; | |
967 | ||
968 | r = dns_packet_append_key(p, t->key, NULL); | |
969 | if (r < 0) | |
970 | return r; | |
971 | ||
972 | qdcount = 1; | |
973 | ||
7778dfff DM |
974 | if (dns_key_is_shared(t->key)) |
975 | add_known_answers = true; | |
976 | ||
0afa57e2 DM |
977 | /* |
978 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
979 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
980 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
981 | */ | |
982 | ||
983 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
984 | ||
985 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
986 | ||
987 | /* Skip ourselves */ | |
988 | if (other == t) | |
989 | continue; | |
990 | ||
991 | if (other->state != DNS_TRANSACTION_PENDING) | |
992 | continue; | |
993 | ||
994 | if (other->next_attempt_after > ts) | |
995 | continue; | |
996 | ||
997 | if (qdcount >= UINT16_MAX) | |
998 | break; | |
999 | ||
1000 | r = dns_packet_append_key(p, other->key, NULL); | |
1001 | ||
1002 | /* | |
1003 | * If we can't stuff more questions into the packet, just give up. | |
1004 | * One of the 'other' transactions will fire later and take care of the rest. | |
1005 | */ | |
1006 | if (r == -EMSGSIZE) | |
1007 | break; | |
1008 | ||
1009 | if (r < 0) | |
1010 | return r; | |
1011 | ||
c842ff24 | 1012 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1013 | if (r <= 0) |
1014 | continue; | |
1015 | ||
1016 | ts += transaction_get_resend_timeout(other); | |
1017 | ||
1018 | r = sd_event_add_time( | |
1019 | other->scope->manager->event, | |
1020 | &other->timeout_event_source, | |
1021 | clock_boottime_or_monotonic(), | |
1022 | ts, 0, | |
1023 | on_transaction_timeout, other); | |
1024 | if (r < 0) | |
1025 | return r; | |
1026 | ||
1027 | other->state = DNS_TRANSACTION_PENDING; | |
1028 | other->next_attempt_after = ts; | |
1029 | ||
1030 | qdcount ++; | |
7778dfff DM |
1031 | |
1032 | if (dns_key_is_shared(other->key)) | |
1033 | add_known_answers = true; | |
0afa57e2 DM |
1034 | } |
1035 | ||
1036 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1037 | |
7778dfff DM |
1038 | /* Append known answer section if we're asking for any shared record */ |
1039 | if (add_known_answers) { | |
1040 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1041 | if (r < 0) | |
1042 | return r; | |
1043 | } | |
1044 | ||
0afa57e2 DM |
1045 | t->sent = p; |
1046 | p = NULL; | |
1047 | ||
1048 | return 0; | |
1049 | } | |
1050 | ||
1051 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1052 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1053 | int r; | |
1054 | ||
1055 | assert(t); | |
1056 | ||
1057 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1058 | return dns_transaction_make_packet_mdns(t); | |
1059 | ||
1060 | if (t->sent) | |
1061 | return 0; | |
1062 | ||
b652d4a2 | 1063 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1064 | if (r < 0) |
1065 | return r; | |
1066 | ||
1067 | r = dns_scope_good_key(t->scope, t->key); | |
1068 | if (r < 0) | |
1069 | return r; | |
1070 | if (r == 0) | |
1071 | return -EDOM; | |
1072 | ||
1073 | r = dns_packet_append_key(p, t->key, NULL); | |
1074 | if (r < 0) | |
1075 | return r; | |
1076 | ||
1077 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1078 | DNS_PACKET_HEADER(p)->id = t->id; | |
1079 | ||
1080 | t->sent = p; | |
1081 | p = NULL; | |
1082 | ||
1083 | return 0; | |
1084 | } | |
1085 | ||
1effe965 DM |
1086 | int dns_transaction_go(DnsTransaction *t) { |
1087 | usec_t ts; | |
1088 | int r; | |
1089 | ||
1090 | assert(t); | |
1091 | ||
1092 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
547973de | 1093 | |
c842ff24 | 1094 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1095 | if (r <= 0) |
1096 | return r; | |
1097 | ||
a5784c49 LP |
1098 | log_debug("Excercising transaction %" PRIu16 " for <%s> on scope %s on %s/%s.", |
1099 | t->id, | |
1100 | dns_transaction_key_string(t), | |
1101 | dns_protocol_to_string(t->scope->protocol), | |
1102 | t->scope->link ? t->scope->link->name : "*", | |
1103 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); | |
1effe965 | 1104 | |
ef7ce6df | 1105 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1106 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1107 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1108 | usec_t jitter, accuracy; | |
6e068472 LP |
1109 | |
1110 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1111 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1112 | ||
ef7ce6df | 1113 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1114 | |
1115 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1116 | |
1117 | switch (t->scope->protocol) { | |
519ef046 | 1118 | |
ea12bcc7 DM |
1119 | case DNS_PROTOCOL_LLMNR: |
1120 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1121 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1122 | break; | |
519ef046 | 1123 | |
ea12bcc7 DM |
1124 | case DNS_PROTOCOL_MDNS: |
1125 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1126 | jitter += MDNS_JITTER_MIN_USEC; | |
1127 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1128 | break; | |
1129 | default: | |
1130 | assert_not_reached("bad protocol"); | |
1131 | } | |
6e068472 LP |
1132 | |
1133 | r = sd_event_add_time( | |
1134 | t->scope->manager->event, | |
1135 | &t->timeout_event_source, | |
1136 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1137 | ts + jitter, accuracy, |
6e068472 LP |
1138 | on_transaction_timeout, t); |
1139 | if (r < 0) | |
1140 | return r; | |
1141 | ||
1142 | t->n_attempts = 0; | |
a9da14e1 | 1143 | t->next_attempt_after = ts; |
6e068472 LP |
1144 | t->state = DNS_TRANSACTION_PENDING; |
1145 | ||
ea12bcc7 | 1146 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1147 | return 0; |
1148 | } | |
1149 | ||
ec2c5e43 LP |
1150 | /* Otherwise, we need to ask the network */ |
1151 | r = dns_transaction_make_packet(t); | |
1152 | if (r == -EDOM) { | |
1153 | /* Not the right request to make on this network? | |
1154 | * (i.e. an A request made on IPv6 or an AAAA request | |
1155 | * made on IPv4, on LLMNR or mDNS.) */ | |
1156 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1157 | return 0; | |
1158 | } | |
1159 | if (r < 0) | |
1160 | return r; | |
1161 | ||
1162 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
f52e61da LP |
1163 | (dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "in-addr.arpa") > 0 || |
1164 | dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1165 | |
1166 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1167 | * always be made via TCP on LLMNR */ | |
1168 | r = dns_transaction_open_tcp(t); | |
1169 | } else { | |
be808ea0 TG |
1170 | /* Try via UDP, and if that fails due to large size or lack of |
1171 | * support try via TCP */ | |
49cce12d | 1172 | r = dns_transaction_emit_udp(t); |
be808ea0 | 1173 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1174 | r = dns_transaction_open_tcp(t); |
1175 | } | |
be808ea0 | 1176 | |
ec2c5e43 LP |
1177 | if (r == -ESRCH) { |
1178 | /* No servers to send this to? */ | |
1179 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1180 | return 0; | |
8300ba21 | 1181 | } else if (r < 0) { |
13b551ac LP |
1182 | if (t->scope->protocol != DNS_PROTOCOL_DNS) { |
1183 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
1184 | return 0; | |
1185 | } | |
1186 | ||
ec2c5e43 | 1187 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1188 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1189 | |
1190 | return dns_transaction_go(t); | |
1191 | } | |
1192 | ||
a9da14e1 DM |
1193 | ts += transaction_get_resend_timeout(t); |
1194 | ||
9a015429 LP |
1195 | r = sd_event_add_time( |
1196 | t->scope->manager->event, | |
1197 | &t->timeout_event_source, | |
1198 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1199 | ts, 0, |
9a015429 | 1200 | on_transaction_timeout, t); |
ec2c5e43 LP |
1201 | if (r < 0) |
1202 | return r; | |
1203 | ||
1204 | t->state = DNS_TRANSACTION_PENDING; | |
a9da14e1 DM |
1205 | t->next_attempt_after = ts; |
1206 | ||
ec2c5e43 LP |
1207 | return 1; |
1208 | } | |
1209 | ||
547973de LP |
1210 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1211 | DnsTransaction *aux; | |
1212 | int r; | |
1213 | ||
1214 | assert(t); | |
1215 | assert(ret); | |
1216 | assert(key); | |
1217 | ||
1218 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1219 | if (!aux) { | |
1220 | r = dns_transaction_new(&aux, t->scope, key); | |
1221 | if (r < 0) | |
1222 | return r; | |
1223 | } else { | |
1224 | if (set_contains(t->dnssec_transactions, aux)) { | |
1225 | *ret = aux; | |
1226 | return 0; | |
1227 | } | |
1228 | } | |
1229 | ||
1230 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1231 | if (r < 0) | |
1232 | goto gc; | |
1233 | ||
1234 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1235 | if (r < 0) | |
1236 | goto gc; | |
1237 | ||
1238 | r = set_put(t->dnssec_transactions, aux); | |
1239 | if (r < 0) | |
1240 | goto gc; | |
1241 | ||
1242 | r = set_put(aux->notify_transactions, t); | |
1243 | if (r < 0) { | |
1244 | (void) set_remove(t->dnssec_transactions, aux); | |
1245 | goto gc; | |
1246 | } | |
1247 | ||
1248 | *ret = aux; | |
1249 | return 1; | |
1250 | ||
1251 | gc: | |
1252 | dns_transaction_gc(aux); | |
1253 | return r; | |
1254 | } | |
1255 | ||
1256 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1257 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1258 | DnsTransaction *aux; | |
1259 | int r; | |
1260 | ||
1261 | assert(t); | |
1262 | assert(key); | |
1263 | ||
aae6a86e LP |
1264 | r = dns_resource_key_equal(t->key, key); |
1265 | if (r < 0) | |
1266 | return r; | |
1267 | if (r > 0) /* Don't go in circles */ | |
1268 | return 0; | |
1269 | ||
547973de LP |
1270 | /* Try to get the data from the trust anchor */ |
1271 | r = dns_trust_anchor_lookup(&t->scope->manager->trust_anchor, key, &a); | |
1272 | if (r < 0) | |
1273 | return r; | |
1274 | if (r > 0) { | |
1275 | r = dns_answer_extend(&t->validated_keys, a); | |
1276 | if (r < 0) | |
1277 | return r; | |
1278 | ||
1279 | return 0; | |
1280 | } | |
1281 | ||
1282 | /* This didn't work, ask for it via the network/cache then. */ | |
1283 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
1284 | if (r < 0) | |
1285 | return r; | |
1286 | ||
1287 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1288 | r = dns_transaction_go(aux); | |
1289 | if (r < 0) | |
1290 | return r; | |
1291 | } | |
1292 | ||
1293 | return 0; | |
1294 | } | |
1295 | ||
105e1512 LP |
1296 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
1297 | int r; | |
1298 | ||
1299 | assert(t); | |
1300 | ||
1301 | /* Checks whether the answer is positive, i.e. either a direct | |
1302 | * answer to the question, or a CNAME/DNAME for it */ | |
1303 | ||
1304 | r = dns_answer_match_key(t->answer, t->key, flags); | |
1305 | if (r != 0) | |
1306 | return r; | |
1307 | ||
1308 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
1309 | if (r != 0) | |
1310 | return r; | |
1311 | ||
1312 | return false; | |
1313 | } | |
1314 | ||
1315 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { | |
1316 | int r; | |
1317 | ||
1318 | assert(t); | |
1319 | ||
1320 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1321 | * RRs to prove it */ | |
1322 | ||
1323 | r = dns_transaction_has_positive_answer(t, NULL); | |
1324 | if (r < 0) | |
1325 | return r; | |
1326 | if (r > 0) | |
1327 | return false; | |
1328 | ||
1329 | /* The answer does not contain any RRs that match to the | |
1330 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1331 | * included. If not, the answer is unsigned. */ | |
1332 | ||
1333 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1334 | if (r < 0) | |
1335 | return r; | |
1336 | if (r > 0) | |
1337 | return false; | |
1338 | ||
1339 | return true; | |
1340 | } | |
1341 | ||
1342 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1343 | int r; | |
1344 | ||
1345 | assert(t); | |
1346 | assert(rr); | |
1347 | ||
1348 | /* Check if the specified RR is the "primary" response, | |
1349 | * i.e. either matches the question precisely or is a | |
1350 | * CNAME/DNAME for it, or is any kind of NSEC/NSEC3 RR */ | |
1351 | ||
1352 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1353 | if (r != 0) | |
1354 | return r; | |
1355 | ||
1356 | r = dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); | |
1357 | if (r != 0) | |
1358 | return r; | |
1359 | ||
1360 | if (rr->key->type == DNS_TYPE_NSEC3) { | |
1361 | const char *p; | |
1362 | ||
1363 | p = DNS_RESOURCE_KEY_NAME(rr->key); | |
1364 | r = dns_name_parent(&p); | |
1365 | if (r < 0) | |
1366 | return r; | |
1367 | if (r > 0) { | |
1368 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), p); | |
1369 | if (r < 0) | |
1370 | return r; | |
1371 | if (r > 0) | |
1372 | return true; | |
1373 | } | |
1374 | } | |
1375 | ||
1376 | return rr->key->type == DNS_TYPE_NSEC; | |
1377 | } | |
1378 | ||
547973de LP |
1379 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1380 | DnsResourceRecord *rr; | |
105e1512 | 1381 | |
547973de LP |
1382 | int r; |
1383 | ||
1384 | assert(t); | |
1385 | ||
105e1512 LP |
1386 | /* |
1387 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1388 | * we can verify signatures or prove that RRs are rightfully | |
1389 | * unsigned. Specifically: | |
1390 | * | |
1391 | * - For RRSIG we get the matching DNSKEY | |
1392 | * - For DNSKEY we get the matching DS | |
1393 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1394 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 LP |
1395 | * - For other unsigned RRs we get the matching SOA RR |
1396 | * - For SOA/NS/DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
1397 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR | |
1398 | */ | |
1399 | ||
b652d4a2 | 1400 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
1401 | return 0; |
1402 | ||
b652d4a2 LP |
1403 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO) |
1404 | return 0; /* Server doesn't do DNSSEC, there's no point in requesting any RRs then. */ | |
1405 | if (t->server && t->server->rrsig_missing) | |
1406 | return 0; /* Server handles DNSSEC requests, but isn't augmenting responses with RRSIGs. No point in trying DNSSEC then. */ | |
1407 | ||
547973de LP |
1408 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1409 | ||
105e1512 LP |
1410 | if (dns_type_is_pseudo(rr->key->type)) |
1411 | continue; | |
1412 | ||
547973de LP |
1413 | switch (rr->key->type) { |
1414 | ||
1415 | case DNS_TYPE_RRSIG: { | |
1416 | /* For each RRSIG we request the matching DNSKEY */ | |
1417 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1418 | ||
1419 | /* If this RRSIG is about a DNSKEY RR and the | |
1420 | * signer is the same as the owner, then we | |
1421 | * already have the DNSKEY, and we don't have | |
1422 | * to look for more. */ | |
1423 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1424 | r = dns_name_equal(rr->rrsig.signer, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1425 | if (r < 0) | |
1426 | return r; | |
1427 | if (r > 0) | |
1428 | continue; | |
1429 | } | |
1430 | ||
105e1512 LP |
1431 | /* If the signer is not a parent of our |
1432 | * original query, then this is about an | |
1433 | * auxiliary RRset, but not anything we asked | |
1434 | * for. In this case we aren't interested, | |
1435 | * because we don't want to request additional | |
1436 | * RRs for stuff we didn't really ask for, and | |
1437 | * also to avoid request loops, where | |
1438 | * additional RRs from one transaction result | |
1439 | * in another transaction whose additonal RRs | |
1440 | * point back to the original transaction, and | |
1441 | * we deadlock. */ | |
1442 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), rr->rrsig.signer); | |
547973de LP |
1443 | if (r < 0) |
1444 | return r; | |
1445 | if (r == 0) | |
1446 | continue; | |
1447 | ||
1448 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1449 | if (!dnskey) | |
1450 | return -ENOMEM; | |
1451 | ||
105e1512 | 1452 | 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 |
1453 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1454 | if (r < 0) | |
1455 | return r; | |
1456 | break; | |
1457 | } | |
1458 | ||
1459 | case DNS_TYPE_DNSKEY: { | |
1460 | /* For each DNSKEY we request the matching DS */ | |
1461 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1462 | ||
105e1512 LP |
1463 | /* If the DNSKEY we are looking at is not for |
1464 | * zone we are interested in, nor any of its | |
1465 | * parents, we aren't interested, and don't | |
1466 | * request it. After all, we don't want to end | |
1467 | * up in request loops, and want to keep | |
1468 | * additional traffic down. */ | |
1469 | ||
1470 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1471 | if (r < 0) | |
1472 | return r; | |
1473 | if (r == 0) | |
1474 | continue; | |
1475 | ||
547973de LP |
1476 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); |
1477 | if (!ds) | |
1478 | return -ENOMEM; | |
1479 | ||
105e1512 LP |
1480 | 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)); |
1481 | r = dns_transaction_request_dnssec_rr(t, ds); | |
1482 | if (r < 0) | |
1483 | return r; | |
547973de | 1484 | |
105e1512 LP |
1485 | break; |
1486 | } | |
1487 | ||
105e1512 LP |
1488 | case DNS_TYPE_SOA: |
1489 | case DNS_TYPE_NS: { | |
1490 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1491 | ||
1492 | /* For an unsigned SOA or NS, try to acquire | |
1493 | * the matching DS RR, as we are at a zone cut | |
1494 | * then, and whether a DS exists tells us | |
1495 | * whether the zone is signed. Do so only if | |
1496 | * this RR matches our original question, | |
1497 | * however. */ | |
1498 | ||
1499 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1500 | if (r < 0) | |
1501 | return r; | |
1502 | if (r == 0) | |
1503 | continue; | |
1504 | ||
1505 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1506 | if (r < 0) | |
1507 | return r; | |
1508 | if (r > 0) | |
1509 | continue; | |
1510 | ||
1511 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1512 | if (!ds) | |
1513 | return -ENOMEM; | |
1514 | ||
1515 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); | |
547973de LP |
1516 | r = dns_transaction_request_dnssec_rr(t, ds); |
1517 | if (r < 0) | |
1518 | return r; | |
1519 | ||
1520 | break; | |
105e1512 LP |
1521 | } |
1522 | ||
b63fca62 | 1523 | case DNS_TYPE_DS: |
105e1512 LP |
1524 | case DNS_TYPE_CNAME: |
1525 | case DNS_TYPE_DNAME: { | |
1526 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1527 | const char *name; | |
1528 | ||
1529 | /* CNAMEs and DNAMEs cannot be located at a | |
1530 | * zone apex, hence ask for the parent SOA for | |
1531 | * unsigned CNAME/DNAME RRs, maybe that's the | |
1532 | * apex. But do all that only if this is | |
1533 | * actually a response to our original | |
b63fca62 LP |
1534 | * question. |
1535 | * | |
1536 | * Similar for DS RRs, which are signed when | |
1537 | * the parent SOA is signed. */ | |
105e1512 LP |
1538 | |
1539 | r = dns_transaction_is_primary_response(t, rr); | |
1540 | if (r < 0) | |
1541 | return r; | |
1542 | if (r == 0) | |
1543 | continue; | |
1544 | ||
1545 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1546 | if (r < 0) | |
1547 | return r; | |
1548 | if (r > 0) | |
1549 | continue; | |
1550 | ||
1551 | name = DNS_RESOURCE_KEY_NAME(rr->key); | |
1552 | r = dns_name_parent(&name); | |
1553 | if (r < 0) | |
1554 | return r; | |
1555 | if (r == 0) | |
1556 | continue; | |
1557 | ||
1558 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
1559 | if (!soa) | |
1560 | return -ENOMEM; | |
1561 | ||
b63fca62 | 1562 | 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 |
1563 | r = dns_transaction_request_dnssec_rr(t, soa); |
1564 | if (r < 0) | |
1565 | return r; | |
1566 | ||
1567 | break; | |
1568 | } | |
1569 | ||
1570 | default: { | |
1571 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1572 | ||
b63fca62 LP |
1573 | /* For other unsigned RRsets (including |
1574 | * NSEC/NSEC3!), look for proof the zone is | |
1575 | * unsigned, by requesting the SOA RR of the | |
1576 | * zone. However, do so only if they are | |
1577 | * directly relevant to our original | |
105e1512 LP |
1578 | * question. */ |
1579 | ||
1580 | r = dns_transaction_is_primary_response(t, rr); | |
1581 | if (r < 0) | |
1582 | return r; | |
1583 | if (r == 0) | |
1584 | continue; | |
1585 | ||
1586 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1587 | if (r < 0) | |
1588 | return r; | |
1589 | if (r > 0) | |
1590 | continue; | |
1591 | ||
1592 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1593 | if (!soa) | |
1594 | return -ENOMEM; | |
1595 | ||
db5b0e92 | 1596 | 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 |
1597 | r = dns_transaction_request_dnssec_rr(t, soa); |
1598 | if (r < 0) | |
1599 | return r; | |
1600 | break; | |
547973de LP |
1601 | }} |
1602 | } | |
1603 | ||
105e1512 LP |
1604 | /* Above, we requested everything necessary to validate what |
1605 | * we got. Now, let's request what we need to validate what we | |
1606 | * didn't get... */ | |
1607 | ||
1608 | r = dns_transaction_has_unsigned_negative_answer(t); | |
1609 | if (r < 0) | |
1610 | return r; | |
1611 | if (r > 0) { | |
1612 | const char *name; | |
1613 | ||
1614 | name = DNS_RESOURCE_KEY_NAME(t->key); | |
1615 | ||
1616 | /* If this was a SOA or NS request, then this | |
1617 | * indicates that we are not at a zone apex, hence ask | |
1618 | * the parent name instead. If this was a DS request, | |
1619 | * then it's signed when the parent zone is signed, | |
1620 | * hence ask the parent in that case, too. */ | |
1621 | ||
1622 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
1623 | r = dns_name_parent(&name); | |
1624 | if (r < 0) | |
1625 | return r; | |
1626 | if (r > 0) | |
1627 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1628 | else | |
1629 | name = NULL; | |
1630 | } else | |
1631 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1632 | ||
1633 | if (name) { | |
1634 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1635 | ||
1636 | soa = dns_resource_key_new(t->key->class, DNS_TYPE_SOA, name); | |
1637 | if (!soa) | |
1638 | return -ENOMEM; | |
1639 | ||
1640 | r = dns_transaction_request_dnssec_rr(t, soa); | |
1641 | if (r < 0) | |
1642 | return r; | |
1643 | } | |
1644 | } | |
1645 | ||
1646 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
1647 | } |
1648 | ||
1649 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
1650 | int r; | |
1651 | ||
1652 | assert(t); | |
547973de LP |
1653 | assert(source); |
1654 | ||
105e1512 LP |
1655 | if (!IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) |
1656 | return; | |
1657 | ||
547973de | 1658 | /* Invoked whenever any of our auxiliary DNSSEC transactions |
105e1512 LP |
1659 | completed its work. We copy any RRs from that transaction |
1660 | over into our list of validated keys -- but only if the | |
1661 | answer is authenticated. | |
1662 | ||
1663 | Note that we fail our transaction if the auxiliary | |
1664 | transaction failed, except on NXDOMAIN. This is because | |
1665 | some broken DNS servers (Akamai...) will return NXDOMAIN | |
1666 | for empty non-terminals. */ | |
1667 | ||
6773896e | 1668 | switch (source->state) { |
547973de | 1669 | |
6773896e LP |
1670 | case DNS_TRANSACTION_DNSSEC_FAILED: |
1671 | ||
1672 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(source->answer_dnssec_result)); | |
1673 | t->answer_dnssec_result = source->answer_dnssec_result; /* Copy error code over */ | |
1674 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
1675 | break; | |
1676 | ||
1677 | case DNS_TRANSACTION_RCODE_FAILURE: | |
1678 | ||
1679 | if (source->answer_rcode != DNS_RCODE_NXDOMAIN) { | |
1680 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%i.", source->answer_rcode); | |
105e1512 | 1681 | goto fail; |
547973de | 1682 | } |
547973de | 1683 | |
6773896e LP |
1684 | /* fall-through: NXDOMAIN is good enough for us */ |
1685 | ||
1686 | case DNS_TRANSACTION_SUCCESS: | |
1687 | if (source->answer_authenticated) { | |
1688 | r = dns_answer_extend(&t->validated_keys, source->answer); | |
1689 | if (r < 0) { | |
1690 | log_error_errno(r, "Failed to merge validated DNSSEC key data: %m"); | |
1691 | goto fail; | |
1692 | } | |
1693 | } | |
1694 | ||
1695 | /* If the state is still PENDING, we are still in the loop | |
1696 | * that adds further DNSSEC transactions, hence don't check if | |
1697 | * we are ready yet. If the state is VALIDATING however, we | |
1698 | * should check if we are complete now. */ | |
1699 | if (t->state == DNS_TRANSACTION_VALIDATING) | |
1700 | dns_transaction_process_dnssec(t); | |
1701 | break; | |
1702 | ||
1703 | default: | |
1704 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(source->state)); | |
1705 | goto fail; | |
1706 | } | |
105e1512 LP |
1707 | |
1708 | return; | |
1709 | ||
1710 | fail: | |
019036a4 | 1711 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; |
105e1512 | 1712 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
547973de LP |
1713 | } |
1714 | ||
105e1512 LP |
1715 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
1716 | DnsResourceRecord *rr; | |
1717 | int ifindex, r; | |
1718 | ||
1719 | assert(t); | |
1720 | ||
1721 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
1722 | * RRs from the list of validated keys to the list of | |
1723 | * validated keys. */ | |
1724 | ||
1725 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
1726 | ||
1727 | r = dnssec_verify_dnskey_search(rr, t->validated_keys); | |
1728 | if (r < 0) | |
1729 | return r; | |
1730 | if (r == 0) | |
1731 | continue; | |
1732 | ||
1733 | /* If so, the DNSKEY is validated too. */ | |
1734 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
1735 | if (r < 0) | |
1736 | return r; | |
1737 | } | |
1738 | ||
1739 | return 0; | |
1740 | } | |
1741 | ||
1742 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
1743 | int r; |
1744 | ||
1745 | assert(t); | |
1746 | assert(rr); | |
1747 | ||
105e1512 LP |
1748 | /* Checks if the RR we are looking for must be signed with an |
1749 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 1750 | |
b652d4a2 | 1751 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 1752 | return false; |
56352fe9 | 1753 | |
105e1512 LP |
1754 | if (dns_type_is_pseudo(rr->key->type)) |
1755 | return -EINVAL; | |
56352fe9 | 1756 | |
105e1512 | 1757 | switch (rr->key->type) { |
56352fe9 | 1758 | |
105e1512 LP |
1759 | case DNS_TYPE_RRSIG: |
1760 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
1761 | return false; | |
1762 | ||
1763 | case DNS_TYPE_SOA: | |
1764 | case DNS_TYPE_NS: { | |
1765 | DnsTransaction *dt; | |
1766 | Iterator i; | |
1767 | ||
b63fca62 | 1768 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
1769 | |
1770 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1771 | ||
1772 | if (dt->key->class != rr->key->class) | |
1773 | continue; | |
1774 | if (dt->key->type != DNS_TYPE_DS) | |
1775 | continue; | |
1776 | ||
1777 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1778 | if (r < 0) | |
1779 | return r; | |
1780 | if (r == 0) | |
1781 | continue; | |
1782 | ||
1783 | /* We found a DS transactions for the SOA/NS | |
1784 | * RRs we are looking at. If it discovered signed DS | |
1785 | * RRs, then we need to be signed, too. */ | |
1786 | ||
097a2517 TA |
1787 | if (!dt->answer_authenticated) |
1788 | return false; | |
105e1512 | 1789 | |
097a2517 | 1790 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
1791 | } |
1792 | ||
1793 | /* We found nothing that proves this is safe to leave | |
1794 | * this unauthenticated, hence ask inist on | |
1795 | * authentication. */ | |
1796 | return true; | |
1797 | } | |
1798 | ||
b63fca62 | 1799 | case DNS_TYPE_DS: |
105e1512 LP |
1800 | case DNS_TYPE_CNAME: |
1801 | case DNS_TYPE_DNAME: { | |
1802 | const char *parent = NULL; | |
1803 | DnsTransaction *dt; | |
1804 | Iterator i; | |
1805 | ||
b63fca62 LP |
1806 | /* |
1807 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
1808 | * | |
1809 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
1810 | */ | |
105e1512 LP |
1811 | |
1812 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1813 | ||
1814 | if (dt->key->class != rr->key->class) | |
1815 | continue; | |
1816 | if (dt->key->type != DNS_TYPE_SOA) | |
1817 | continue; | |
1818 | ||
1819 | if (!parent) { | |
1820 | parent = DNS_RESOURCE_KEY_NAME(rr->key); | |
1821 | r = dns_name_parent(&parent); | |
1822 | if (r < 0) | |
1823 | return r; | |
1824 | if (r == 0) { | |
b63fca62 LP |
1825 | if (rr->key->type == DNS_TYPE_DS) |
1826 | return true; | |
1827 | ||
105e1512 LP |
1828 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
1829 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
1830 | return -EBADMSG; | |
1831 | } | |
1832 | } | |
1833 | ||
1834 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), parent); | |
1835 | if (r < 0) | |
1836 | return r; | |
1837 | if (r == 0) | |
1838 | continue; | |
1839 | ||
1840 | return t->answer_authenticated; | |
1841 | } | |
1842 | ||
1843 | return true; | |
1844 | } | |
1845 | ||
1846 | default: { | |
1847 | DnsTransaction *dt; | |
1848 | Iterator i; | |
1849 | ||
b63fca62 | 1850 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
1851 | |
1852 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1853 | ||
1854 | if (dt->key->class != rr->key->class) | |
1855 | continue; | |
1856 | if (dt->key->type != DNS_TYPE_SOA) | |
1857 | continue; | |
1858 | ||
1859 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1860 | if (r < 0) | |
1861 | return r; | |
1862 | if (r == 0) | |
1863 | continue; | |
1864 | ||
1865 | /* We found the transaction that was supposed to find | |
1866 | * the SOA RR for us. It was successful, but found no | |
1867 | * RR for us. This means we are not at a zone cut. In | |
1868 | * this case, we require authentication if the SOA | |
1869 | * lookup was authenticated too. */ | |
1870 | return t->answer_authenticated; | |
1871 | } | |
1872 | ||
1873 | return true; | |
1874 | }} | |
56352fe9 LP |
1875 | } |
1876 | ||
105e1512 LP |
1877 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
1878 | DnsTransaction *dt; | |
1879 | const char *name; | |
1880 | Iterator i; | |
1881 | int r; | |
56352fe9 LP |
1882 | |
1883 | assert(t); | |
1884 | ||
105e1512 LP |
1885 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
1886 | * this negative reply */ | |
56352fe9 | 1887 | |
b652d4a2 | 1888 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 1889 | return false; |
56352fe9 | 1890 | |
105e1512 LP |
1891 | if (dns_type_is_pseudo(t->key->type)) |
1892 | return -EINVAL; | |
1893 | ||
1894 | name = DNS_RESOURCE_KEY_NAME(t->key); | |
1895 | ||
1896 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
1897 | ||
1898 | /* We got a negative reply for this SOA/NS lookup? If | |
1899 | * so, then we are not at a zone apex, and thus should | |
1900 | * look at the result of the parent SOA lookup. | |
1901 | * | |
1902 | * We got a negative reply for this DS lookup? DS RRs | |
1903 | * are signed when their parent zone is signed, hence | |
1904 | * also check the parent SOA in this case. */ | |
1905 | ||
1906 | r = dns_name_parent(&name); | |
56352fe9 LP |
1907 | if (r < 0) |
1908 | return r; | |
1909 | if (r == 0) | |
105e1512 LP |
1910 | return true; |
1911 | } | |
1912 | ||
1913 | /* For all other RRs we check the SOA on the same level to see | |
1914 | * if it's signed. */ | |
1915 | ||
1916 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1917 | ||
1918 | if (dt->key->class != t->key->class) | |
1919 | continue; | |
1920 | if (dt->key->type != DNS_TYPE_SOA) | |
56352fe9 LP |
1921 | continue; |
1922 | ||
105e1512 | 1923 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), name); |
56352fe9 LP |
1924 | if (r < 0) |
1925 | return r; | |
105e1512 LP |
1926 | if (r == 0) |
1927 | continue; | |
1928 | ||
1929 | return dt->answer_authenticated; | |
56352fe9 LP |
1930 | } |
1931 | ||
105e1512 LP |
1932 | /* If in doubt, require NSEC/NSEC3 */ |
1933 | return true; | |
56352fe9 LP |
1934 | } |
1935 | ||
94aa7071 LP |
1936 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
1937 | DnsResourceRecord *rrsig; | |
1938 | bool found = false; | |
1939 | int r; | |
1940 | ||
1941 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
1942 | * the specified RRset is authenticated (i.e. has a matching | |
1943 | * DS RR). */ | |
1944 | ||
1945 | DNS_ANSWER_FOREACH(rrsig, t->answer) { | |
1946 | DnsTransaction *dt; | |
1947 | Iterator i; | |
1948 | ||
1949 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
1950 | if (r < 0) | |
1951 | return r; | |
1952 | if (r == 0) | |
1953 | continue; | |
1954 | ||
1955 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1956 | ||
1957 | if (dt->key->class != rr->key->class) | |
1958 | continue; | |
1959 | ||
1960 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
1961 | ||
1962 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
1963 | if (r < 0) | |
1964 | return r; | |
1965 | if (r == 0) | |
1966 | continue; | |
1967 | ||
1968 | /* OK, we found an auxiliary DNSKEY | |
1969 | * lookup. If that lookup is | |
1970 | * authenticated, report this. */ | |
1971 | ||
1972 | if (dt->answer_authenticated) | |
1973 | return true; | |
1974 | ||
1975 | found = true; | |
1976 | ||
1977 | } else if (dt->key->type == DNS_TYPE_DS) { | |
1978 | ||
1979 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
1980 | if (r < 0) | |
1981 | return r; | |
1982 | if (r == 0) | |
1983 | continue; | |
1984 | ||
1985 | /* OK, we found an auxiliary DS | |
1986 | * lookup. If that lookup is | |
1987 | * authenticated and non-zero, we | |
1988 | * won! */ | |
1989 | ||
1990 | if (!dt->answer_authenticated) | |
1991 | return false; | |
1992 | ||
1993 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
1994 | } | |
1995 | } | |
1996 | } | |
1997 | ||
1998 | return found ? false : -ENXIO; | |
1999 | } | |
2000 | ||
b652d4a2 LP |
2001 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2002 | assert(t); | |
2003 | assert(rr); | |
2004 | ||
2005 | /* We know that the root domain is signed, hence if it appears | |
2006 | * not to be signed, there's a problem with the DNS server */ | |
2007 | ||
2008 | return rr->key->class == DNS_CLASS_IN && | |
2009 | dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key)); | |
2010 | } | |
2011 | ||
547973de LP |
2012 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2013 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
56352fe9 | 2014 | bool dnskeys_finalized = false; |
547973de | 2015 | DnsResourceRecord *rr; |
105e1512 | 2016 | DnsAnswerFlags flags; |
56352fe9 | 2017 | int r; |
547973de LP |
2018 | |
2019 | assert(t); | |
2020 | ||
2021 | /* We have now collected all DS and DNSKEY RRs in | |
2022 | * t->validated_keys, let's see which RRs we can now | |
2023 | * authenticate with that. */ | |
2024 | ||
b652d4a2 | 2025 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
2026 | return 0; |
2027 | ||
2028 | /* Already validated */ | |
019036a4 | 2029 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) |
547973de LP |
2030 | return 0; |
2031 | ||
105e1512 | 2032 | /* Our own stuff needs no validation */ |
547973de | 2033 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { |
019036a4 | 2034 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
547973de LP |
2035 | t->answer_authenticated = true; |
2036 | return 0; | |
2037 | } | |
2038 | ||
105e1512 LP |
2039 | /* Cached stuff is not affected by validation. */ |
2040 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2041 | return 0; | |
2042 | ||
b652d4a2 LP |
2043 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO || |
2044 | (t->server && t->server->rrsig_missing)) { | |
2045 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2046 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2047 | return 0; | |
2048 | } | |
2049 | ||
a5784c49 | 2050 | log_debug("Validating response from transaction %" PRIu16 " (%s).", t->id, dns_transaction_key_string(t)); |
547973de LP |
2051 | |
2052 | /* First see if there are DNSKEYs we already known a validated DS for. */ | |
56352fe9 LP |
2053 | r = dns_transaction_validate_dnskey_by_ds(t); |
2054 | if (r < 0) | |
2055 | return r; | |
547973de LP |
2056 | |
2057 | for (;;) { | |
56352fe9 | 2058 | bool changed = false; |
547973de LP |
2059 | |
2060 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
2061 | DnssecResult result; | |
2062 | ||
2063 | if (rr->key->type == DNS_TYPE_RRSIG) | |
2064 | continue; | |
2065 | ||
2066 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result); | |
2067 | if (r < 0) | |
2068 | return r; | |
2069 | ||
7b50eb2e | 2070 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
547973de | 2071 | |
56352fe9 | 2072 | if (result == DNSSEC_VALIDATED) { |
547973de | 2073 | |
547973de LP |
2074 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2075 | /* If we just validated a | |
2076 | * DNSKEY RRset, then let's | |
2077 | * add these keys to the set | |
2078 | * of validated keys for this | |
2079 | * transaction. */ | |
2080 | ||
105e1512 | 2081 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
547973de LP |
2082 | if (r < 0) |
2083 | return r; | |
2084 | } | |
2085 | ||
105e1512 LP |
2086 | /* Add the validated RRset to the new |
2087 | * list of validated RRsets, and | |
2088 | * remove it from the unvalidated | |
2089 | * RRsets. We mark the RRset as | |
2090 | * authenticated and cacheable. */ | |
2091 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
547973de LP |
2092 | if (r < 0) |
2093 | return r; | |
2094 | ||
a150ff5e LP |
2095 | t->scope->manager->n_dnssec_secure++; |
2096 | ||
56352fe9 | 2097 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2098 | changed = true; |
2099 | break; | |
2100 | ||
56352fe9 | 2101 | } else if (dnskeys_finalized) { |
94aa7071 | 2102 | |
56352fe9 LP |
2103 | /* If we haven't read all DNSKEYs yet |
2104 | * a negative result of the validation | |
2105 | * is irrelevant, as there might be | |
2106 | * more DNSKEYs coming. */ | |
547973de | 2107 | |
105e1512 LP |
2108 | if (result == DNSSEC_NO_SIGNATURE) { |
2109 | r = dns_transaction_requires_rrsig(t, rr); | |
2110 | if (r < 0) | |
2111 | return r; | |
2112 | if (r == 0) { | |
2113 | /* Data does not require signing. In that case, just copy it over, | |
2114 | * but remember that this is by no means authenticated.*/ | |
2115 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2116 | if (r < 0) | |
2117 | return r; | |
2118 | ||
a150ff5e LP |
2119 | t->scope->manager->n_dnssec_insecure++; |
2120 | ||
105e1512 LP |
2121 | changed = true; |
2122 | break; | |
2123 | } | |
b652d4a2 LP |
2124 | |
2125 | r = dns_transaction_known_signed(t, rr); | |
2126 | if (r < 0) | |
2127 | return r; | |
2128 | if (r > 0) { | |
2129 | /* This is an RR we know has to be signed. If it isn't this means | |
2130 | * the server is not attaching RRSIGs, hence complain. */ | |
2131 | ||
2132 | dns_server_packet_rrsig_missing(t->server); | |
2133 | ||
2134 | if (t->scope->dnssec_mode == DNSSEC_DOWNGRADE_OK) { | |
2135 | ||
2136 | /* Downgrading is OK? If so, just consider the information unsigned */ | |
2137 | ||
2138 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2139 | if (r < 0) | |
2140 | return r; | |
2141 | ||
2142 | t->scope->manager->n_dnssec_insecure++; | |
2143 | changed = true; | |
2144 | break; | |
2145 | } | |
2146 | ||
2147 | /* Otherwise, fail */ | |
2148 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2149 | return 0; | |
2150 | } | |
94aa7071 LP |
2151 | } |
2152 | ||
2153 | if (IN_SET(result, | |
2154 | DNSSEC_MISSING_KEY, | |
2155 | DNSSEC_SIGNATURE_EXPIRED, | |
2156 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
2157 | ||
2158 | r = dns_transaction_dnskey_authenticated(t, rr); | |
2159 | if (r < 0 && r != -ENXIO) | |
2160 | return r; | |
2161 | if (r == 0) { | |
2162 | /* The DNSKEY transaction was not authenticated, this means there's | |
2163 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
2164 | ||
2165 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2166 | if (r < 0) | |
2167 | return r; | |
2168 | ||
a150ff5e LP |
2169 | t->scope->manager->n_dnssec_insecure++; |
2170 | ||
94aa7071 LP |
2171 | changed = true; |
2172 | break; | |
2173 | } | |
105e1512 LP |
2174 | } |
2175 | ||
a150ff5e LP |
2176 | if (IN_SET(result, |
2177 | DNSSEC_INVALID, | |
2178 | DNSSEC_SIGNATURE_EXPIRED, | |
2179 | DNSSEC_NO_SIGNATURE, | |
2180 | DNSSEC_UNSUPPORTED_ALGORITHM)) | |
2181 | t->scope->manager->n_dnssec_bogus++; | |
2182 | else | |
2183 | t->scope->manager->n_dnssec_indeterminate++; | |
2184 | ||
56352fe9 | 2185 | r = dns_transaction_is_primary_response(t, rr); |
547973de LP |
2186 | if (r < 0) |
2187 | return r; | |
2188 | if (r > 0) { | |
56352fe9 LP |
2189 | /* This is a primary response |
2190 | * to our question, and it | |
2191 | * failed validation. That's | |
2192 | * fatal. */ | |
019036a4 | 2193 | t->answer_dnssec_result = result; |
547973de LP |
2194 | return 0; |
2195 | } | |
2196 | ||
56352fe9 LP |
2197 | /* This is just some auxiliary |
2198 | * data. Just remove the RRset and | |
2199 | * continue. */ | |
547973de LP |
2200 | r = dns_answer_remove_by_key(&t->answer, rr->key); |
2201 | if (r < 0) | |
2202 | return r; | |
2203 | ||
56352fe9 | 2204 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2205 | changed = true; |
2206 | break; | |
547973de | 2207 | } |
547973de LP |
2208 | } |
2209 | ||
2210 | if (changed) | |
2211 | continue; | |
2212 | ||
56352fe9 LP |
2213 | if (!dnskeys_finalized) { |
2214 | /* OK, now we know we have added all DNSKEYs | |
2215 | * we possibly could to our validated | |
2216 | * list. Now run the whole thing once more, | |
2217 | * and strip everything we still cannot | |
2218 | * validate. | |
2219 | */ | |
2220 | dnskeys_finalized = true; | |
2221 | continue; | |
547973de LP |
2222 | } |
2223 | ||
56352fe9 | 2224 | /* We're done */ |
547973de LP |
2225 | break; |
2226 | } | |
2227 | ||
2228 | dns_answer_unref(t->answer); | |
2229 | t->answer = validated; | |
2230 | validated = NULL; | |
2231 | ||
72667f08 LP |
2232 | /* At this point the answer only contains validated |
2233 | * RRsets. Now, let's see if it actually answers the question | |
2234 | * we asked. If so, great! If it doesn't, then see if | |
2235 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2236 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2237 | if (r > 0) { |
105e1512 LP |
2238 | /* Yes, it answers the question! */ |
2239 | ||
2240 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2241 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2242 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2243 | t->answer_rcode = DNS_RCODE_SUCCESS; |
2244 | t->answer_authenticated = true; | |
2245 | } else { | |
2246 | /* The answer is not fully authenticated. */ | |
019036a4 | 2247 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2248 | t->answer_authenticated = false; |
2249 | } | |
2250 | ||
72667f08 LP |
2251 | } else if (r == 0) { |
2252 | DnssecNsecResult nr; | |
ed29bfdc | 2253 | bool authenticated = false; |
72667f08 LP |
2254 | |
2255 | /* Bummer! Let's check NSEC/NSEC3 */ | |
ed29bfdc | 2256 | r = dnssec_test_nsec(t->answer, t->key, &nr, &authenticated); |
72667f08 LP |
2257 | if (r < 0) |
2258 | return r; | |
2259 | ||
2260 | switch (nr) { | |
2261 | ||
2262 | case DNSSEC_NSEC_NXDOMAIN: | |
2263 | /* NSEC proves the domain doesn't exist. Very good. */ | |
105e1512 | 2264 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2265 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2266 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 2267 | t->answer_authenticated = authenticated; |
72667f08 LP |
2268 | break; |
2269 | ||
2270 | case DNSSEC_NSEC_NODATA: | |
2271 | /* NSEC proves that there's no data here, very good. */ | |
105e1512 | 2272 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2273 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2274 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 2275 | t->answer_authenticated = authenticated; |
72667f08 LP |
2276 | break; |
2277 | ||
105e1512 LP |
2278 | case DNSSEC_NSEC_OPTOUT: |
2279 | /* NSEC3 says the data might not be signed */ | |
2280 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); | |
019036a4 | 2281 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2282 | t->answer_authenticated = false; |
2283 | break; | |
2284 | ||
72667f08 LP |
2285 | case DNSSEC_NSEC_NO_RR: |
2286 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
2287 | |
2288 | r = dns_transaction_requires_nsec(t); | |
2289 | if (r < 0) | |
2290 | return r; | |
2291 | if (r > 0) | |
019036a4 | 2292 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
105e1512 | 2293 | else { |
019036a4 | 2294 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2295 | t->answer_authenticated = false; |
2296 | } | |
2297 | ||
2298 | break; | |
2299 | ||
2300 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
2301 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 2302 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
72667f08 LP |
2303 | break; |
2304 | ||
2305 | case DNSSEC_NSEC_FOUND: | |
2306 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ | |
019036a4 | 2307 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
72667f08 LP |
2308 | break; |
2309 | ||
2310 | default: | |
2311 | assert_not_reached("Unexpected NSEC result."); | |
2312 | } | |
2313 | } | |
2314 | ||
547973de LP |
2315 | return 1; |
2316 | } | |
2317 | ||
a5784c49 LP |
2318 | const char *dns_transaction_key_string(DnsTransaction *t) { |
2319 | assert(t); | |
2320 | ||
2321 | if (!t->key_string) { | |
2322 | if (dns_resource_key_to_string(t->key, &t->key_string) < 0) | |
2323 | return "n/a"; | |
2324 | } | |
2325 | ||
2326 | return strstrip(t->key_string); | |
2327 | } | |
2328 | ||
ec2c5e43 LP |
2329 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
2330 | [DNS_TRANSACTION_NULL] = "null", | |
2331 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 2332 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 2333 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
2334 | [DNS_TRANSACTION_SUCCESS] = "success", |
2335 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
2336 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
2337 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
2338 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
2339 | [DNS_TRANSACTION_RESOURCES] = "resources", | |
ac720200 | 2340 | [DNS_TRANSACTION_CONNECTION_FAILURE] = "connection-failure", |
ec2c5e43 | 2341 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 2342 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
ec2c5e43 LP |
2343 | }; |
2344 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
2345 | |
2346 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
2347 | [DNS_TRANSACTION_NETWORK] = "network", | |
2348 | [DNS_TRANSACTION_CACHE] = "cache", | |
2349 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 2350 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
2351 | }; |
2352 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |