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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 | ||
8d10d620 LP |
339 | static void dns_transaction_retry(DnsTransaction *t) { |
340 | int r; | |
341 | ||
342 | assert(t); | |
343 | ||
344 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
345 | ||
346 | /* Before we try again, switch to a new server. */ | |
347 | dns_scope_next_dns_server(t->scope); | |
348 | ||
349 | r = dns_transaction_go(t); | |
350 | if (r < 0) | |
351 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
352 | } | |
353 | ||
ec2c5e43 LP |
354 | static int on_stream_complete(DnsStream *s, int error) { |
355 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
356 | DnsTransaction *t; | |
357 | ||
358 | assert(s); | |
359 | assert(s->transaction); | |
360 | ||
361 | /* Copy the data we care about out of the stream before we | |
362 | * destroy it. */ | |
363 | t = s->transaction; | |
364 | p = dns_packet_ref(s->read_packet); | |
365 | ||
366 | t->stream = dns_stream_free(t->stream); | |
367 | ||
ac720200 LP |
368 | if (IN_SET(error, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE)) { |
369 | dns_transaction_complete(t, DNS_TRANSACTION_CONNECTION_FAILURE); | |
370 | return 0; | |
371 | } | |
372 | ||
ec2c5e43 LP |
373 | if (error != 0) { |
374 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
375 | return 0; | |
376 | } | |
377 | ||
a4076574 | 378 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 379 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
380 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
381 | return 0; | |
382 | } | |
383 | ||
384 | dns_scope_check_conflicts(t->scope, p); | |
385 | ||
ec2c5e43 LP |
386 | t->block_gc++; |
387 | dns_transaction_process_reply(t, p); | |
388 | t->block_gc--; | |
389 | ||
519ef046 LP |
390 | /* If the response wasn't useful, then complete the transition |
391 | * now. After all, we are the worst feature set now with TCP | |
392 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
393 | if (t->state == DNS_TRANSACTION_PENDING) |
394 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
395 | else |
396 | dns_transaction_gc(t); | |
ec2c5e43 LP |
397 | |
398 | return 0; | |
399 | } | |
400 | ||
401 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
402 | _cleanup_close_ int fd = -1; | |
403 | int r; | |
404 | ||
405 | assert(t); | |
406 | ||
519ef046 | 407 | dns_transaction_close_connection(t); |
ec2c5e43 | 408 | |
106784eb | 409 | switch (t->scope->protocol) { |
519ef046 | 410 | |
106784eb | 411 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
412 | r = dns_transaction_pick_server(t); |
413 | if (r < 0) | |
414 | return r; | |
415 | ||
416 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
417 | if (r < 0) | |
418 | return r; | |
419 | ||
420 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 421 | break; |
ec2c5e43 | 422 | |
106784eb | 423 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 424 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 425 | if (t->received) |
519ef046 | 426 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
427 | else { |
428 | union in_addr_union address; | |
a7f7d1bd | 429 | int family = AF_UNSPEC; |
ec2c5e43 LP |
430 | |
431 | /* Otherwise, try to talk to the owner of a | |
432 | * the IP address, in case this is a reverse | |
433 | * PTR lookup */ | |
f52e61da LP |
434 | |
435 | r = dns_name_address(DNS_RESOURCE_KEY_NAME(t->key), &family, &address); | |
ec2c5e43 LP |
436 | if (r < 0) |
437 | return r; | |
438 | if (r == 0) | |
439 | return -EINVAL; | |
9e08a6e0 | 440 | if (family != t->scope->family) |
9318cdd3 | 441 | return -ESRCH; |
ec2c5e43 | 442 | |
519ef046 | 443 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 444 | } |
106784eb DM |
445 | |
446 | break; | |
447 | ||
448 | default: | |
ec2c5e43 | 449 | return -EAFNOSUPPORT; |
106784eb | 450 | } |
ec2c5e43 LP |
451 | |
452 | if (fd < 0) | |
453 | return fd; | |
454 | ||
455 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
456 | if (r < 0) | |
457 | return r; | |
ec2c5e43 LP |
458 | fd = -1; |
459 | ||
460 | r = dns_stream_write_packet(t->stream, t->sent); | |
461 | if (r < 0) { | |
462 | t->stream = dns_stream_free(t->stream); | |
463 | return r; | |
464 | } | |
465 | ||
ec2c5e43 LP |
466 | t->stream->complete = on_stream_complete; |
467 | t->stream->transaction = t; | |
468 | ||
469 | /* The interface index is difficult to determine if we are | |
470 | * connecting to the local host, hence fill this in right away | |
471 | * instead of determining it from the socket */ | |
472 | if (t->scope->link) | |
473 | t->stream->ifindex = t->scope->link->ifindex; | |
474 | ||
519ef046 LP |
475 | dns_transaction_reset_answer(t); |
476 | ||
cbe4216d LP |
477 | t->tried_stream = true; |
478 | ||
ec2c5e43 LP |
479 | return 0; |
480 | } | |
481 | ||
547973de | 482 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
483 | assert(t); |
484 | ||
485 | /* For mDNS we cache whenever we get the packet, rather than | |
486 | * in each transaction. */ | |
487 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
488 | return; | |
489 | ||
490 | /* We never cache if this packet is from the local host, under | |
491 | * the assumption that a locally running DNS server would | |
492 | * cache this anyway, and probably knows better when to flush | |
493 | * the cache then we could. */ | |
494 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
495 | return; | |
496 | ||
547973de LP |
497 | dns_cache_put(&t->scope->cache, |
498 | t->key, | |
499 | t->answer_rcode, | |
500 | t->answer, | |
547973de | 501 | t->answer_authenticated, |
d3760be0 | 502 | t->answer_nsec_ttl, |
547973de LP |
503 | 0, |
504 | t->received->family, | |
505 | &t->received->sender); | |
506 | } | |
507 | ||
105e1512 LP |
508 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
509 | DnsTransaction *dt; | |
510 | Iterator i; | |
511 | ||
512 | assert(t); | |
513 | ||
514 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
515 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
516 | return true; | |
517 | ||
518 | return false; | |
519 | } | |
520 | ||
547973de LP |
521 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
522 | int r; | |
523 | ||
524 | assert(t); | |
525 | ||
526 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
105e1512 | 527 | if (dns_transaction_dnssec_is_live(t)) |
547973de LP |
528 | return; |
529 | ||
530 | /* All our auxiliary DNSSEC transactions are complete now. Try | |
531 | * to validate our RRset now. */ | |
532 | r = dns_transaction_validate_dnssec(t); | |
533 | if (r < 0) { | |
534 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
535 | return; | |
536 | } | |
537 | ||
b652d4a2 LP |
538 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
539 | t->scope->dnssec_mode == DNSSEC_YES) { | |
540 | /* We are not in automatic downgrade mode, and the | |
541 | * server is bad, refuse operation. */ | |
542 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
543 | return; | |
544 | } | |
545 | ||
019036a4 | 546 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
547 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
548 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
549 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
550 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
551 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
552 | return; | |
553 | } | |
554 | ||
555 | dns_transaction_cache_answer(t); | |
556 | ||
557 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
558 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
559 | else | |
3bbdc31d | 560 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
547973de LP |
561 | } |
562 | ||
ec2c5e43 | 563 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 564 | usec_t ts; |
ec2c5e43 LP |
565 | int r; |
566 | ||
567 | assert(t); | |
568 | assert(p); | |
9df3ba6c TG |
569 | assert(t->scope); |
570 | assert(t->scope->manager); | |
ec2c5e43 | 571 | |
5a7e41a3 LP |
572 | if (t->state != DNS_TRANSACTION_PENDING) |
573 | return; | |
574 | ||
ec2c5e43 LP |
575 | /* Note that this call might invalidate the query. Callers |
576 | * should hence not attempt to access the query or transaction | |
577 | * after calling this function. */ | |
578 | ||
b5efcf29 LP |
579 | log_debug("Processing incoming packet on transaction %" PRIu16".", t->id); |
580 | ||
106784eb | 581 | switch (t->scope->protocol) { |
b5efcf29 | 582 | |
106784eb | 583 | case DNS_PROTOCOL_LLMNR: |
ec2c5e43 LP |
584 | assert(t->scope->link); |
585 | ||
586 | /* For LLMNR we will not accept any packets from other | |
587 | * interfaces */ | |
588 | ||
589 | if (p->ifindex != t->scope->link->ifindex) | |
590 | return; | |
591 | ||
592 | if (p->family != t->scope->family) | |
593 | return; | |
594 | ||
595 | /* Tentative packets are not full responses but still | |
596 | * useful for identifying uniqueness conflicts during | |
597 | * probing. */ | |
8b757a38 | 598 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
599 | dns_transaction_tentative(t, p); |
600 | return; | |
601 | } | |
106784eb DM |
602 | |
603 | break; | |
604 | ||
4e5bf5e1 DM |
605 | case DNS_PROTOCOL_MDNS: |
606 | assert(t->scope->link); | |
607 | ||
608 | /* For mDNS we will not accept any packets from other interfaces */ | |
609 | if (p->ifindex != t->scope->link->ifindex) | |
610 | return; | |
611 | ||
612 | if (p->family != t->scope->family) | |
613 | return; | |
614 | ||
615 | break; | |
616 | ||
106784eb | 617 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
618 | /* Note that we do not need to verify the |
619 | * addresses/port numbers of incoming traffic, as we | |
620 | * invoked connect() on our UDP socket in which case | |
621 | * the kernel already does the needed verification for | |
622 | * us. */ | |
106784eb DM |
623 | break; |
624 | ||
625 | default: | |
9c56a6f3 | 626 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
627 | } |
628 | ||
ec2c5e43 LP |
629 | if (t->received != p) { |
630 | dns_packet_unref(t->received); | |
631 | t->received = dns_packet_ref(p); | |
632 | } | |
633 | ||
c3bc53e6 LP |
634 | t->answer_source = DNS_TRANSACTION_NETWORK; |
635 | ||
ec2c5e43 LP |
636 | if (p->ipproto == IPPROTO_TCP) { |
637 | if (DNS_PACKET_TC(p)) { | |
638 | /* Truncated via TCP? Somebody must be fucking with us */ | |
639 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
640 | return; | |
641 | } | |
642 | ||
643 | if (DNS_PACKET_ID(p) != t->id) { | |
644 | /* Not the reply to our query? Somebody must be fucking with us */ | |
645 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
646 | return; | |
647 | } | |
648 | } | |
649 | ||
38a03f06 | 650 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
651 | |
652 | switch (t->scope->protocol) { | |
8af5b883 | 653 | |
9df3ba6c TG |
654 | case DNS_PROTOCOL_DNS: |
655 | assert(t->server); | |
656 | ||
4e0b8b17 TG |
657 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
658 | ||
8af5b883 | 659 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 TG |
660 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
661 | ||
662 | dns_server_packet_failed(t->server, t->current_features); | |
8d10d620 | 663 | dns_transaction_retry(t); |
4e0b8b17 TG |
664 | return; |
665 | } else | |
d74fb368 | 666 | dns_server_packet_received(t->server, t->current_features, ts - t->start_usec, p->size); |
9df3ba6c TG |
667 | |
668 | break; | |
8af5b883 | 669 | |
9df3ba6c TG |
670 | case DNS_PROTOCOL_LLMNR: |
671 | case DNS_PROTOCOL_MDNS: | |
672 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 673 | break; |
8af5b883 | 674 | |
9df3ba6c | 675 | default: |
8af5b883 | 676 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
677 | } |
678 | ||
ec2c5e43 | 679 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
680 | |
681 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
682 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
683 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
684 | return; | |
685 | } | |
686 | ||
ec2c5e43 LP |
687 | /* Response was truncated, let's try again with good old TCP */ |
688 | r = dns_transaction_open_tcp(t); | |
689 | if (r == -ESRCH) { | |
690 | /* No servers found? Damn! */ | |
691 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
692 | return; | |
693 | } | |
694 | if (r < 0) { | |
8af5b883 | 695 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 LP |
696 | * we immediately give up */ |
697 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { | |
698 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
699 | return; | |
700 | } | |
701 | ||
702 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
8d10d620 | 703 | dns_transaction_retry(t); |
ec2c5e43 | 704 | } |
2a6658ef LP |
705 | |
706 | return; | |
ec2c5e43 LP |
707 | } |
708 | ||
8af5b883 | 709 | /* Parse message, if it isn't parsed yet. */ |
ec2c5e43 LP |
710 | r = dns_packet_extract(p); |
711 | if (r < 0) { | |
712 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
713 | return; | |
714 | } | |
715 | ||
b5efcf29 LP |
716 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { |
717 | ||
547493c5 | 718 | /* Only consider responses with equivalent query section to the request */ |
8af5b883 LP |
719 | r = dns_packet_is_reply_for(p, t->key); |
720 | if (r < 0) { | |
721 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
722 | return; | |
723 | } | |
724 | if (r == 0) { | |
547493c5 DM |
725 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
726 | return; | |
727 | } | |
29815b6c | 728 | |
547493c5 DM |
729 | /* Install the answer as answer to the transaction */ |
730 | dns_answer_unref(t->answer); | |
731 | t->answer = dns_answer_ref(p->answer); | |
732 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 733 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 734 | t->answer_authenticated = false; |
79e24931 | 735 | |
51e399bc LP |
736 | /* Block GC while starting requests for additional DNSSEC RRs */ |
737 | t->block_gc++; | |
547973de | 738 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
739 | t->block_gc--; |
740 | ||
741 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
742 | if (!dns_transaction_gc(t)) | |
743 | return; | |
744 | ||
745 | /* Requesting additional keys might have resulted in | |
746 | * this transaction to fail, since the auxiliary | |
747 | * request failed for some reason. If so, we are not | |
748 | * in pending state anymore, and we should exit | |
749 | * quickly. */ | |
750 | if (t->state != DNS_TRANSACTION_PENDING) | |
751 | return; | |
547973de LP |
752 | if (r < 0) { |
753 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
754 | return; | |
755 | } | |
756 | if (r > 0) { | |
757 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
758 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
759 | dns_transaction_close_connection(t); |
760 | dns_transaction_stop_timeout(t); | |
547973de LP |
761 | return; |
762 | } | |
547493c5 | 763 | } |
ec2c5e43 | 764 | |
547973de | 765 | dns_transaction_process_dnssec(t); |
ec2c5e43 LP |
766 | } |
767 | ||
c19ffd9f TG |
768 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
769 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
770 | DnsTransaction *t = userdata; | |
771 | int r; | |
772 | ||
773 | assert(t); | |
774 | assert(t->scope); | |
775 | ||
776 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
777 | if (r <= 0) | |
778 | return r; | |
779 | ||
780 | if (dns_packet_validate_reply(p) > 0 && | |
9df3ba6c | 781 | DNS_PACKET_ID(p) == t->id) |
c19ffd9f | 782 | dns_transaction_process_reply(t, p); |
9df3ba6c | 783 | else |
2c6bf498 | 784 | log_debug("Invalid DNS UDP packet, ignoring."); |
c19ffd9f TG |
785 | |
786 | return 0; | |
787 | } | |
788 | ||
49cce12d | 789 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
790 | int r; |
791 | ||
792 | assert(t); | |
c19ffd9f | 793 | |
519ef046 | 794 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 795 | |
519ef046 | 796 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
797 | if (r < 0) |
798 | return r; | |
c19ffd9f | 799 | |
519ef046 LP |
800 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_UDP) |
801 | return -EAGAIN; | |
802 | ||
803 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ | |
804 | int fd; | |
805 | ||
806 | dns_transaction_close_connection(t); | |
c19ffd9f | 807 | |
519ef046 LP |
808 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
809 | if (fd < 0) | |
810 | return fd; | |
811 | ||
812 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
813 | if (r < 0) { | |
814 | safe_close(fd); | |
815 | return r; | |
816 | } | |
817 | ||
aa4a9deb | 818 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
819 | t->dns_udp_fd = fd; |
820 | } | |
821 | ||
822 | r = dns_server_adjust_opt(t->server, t->sent, t->current_features); | |
823 | if (r < 0) | |
824 | return r; | |
825 | } else | |
826 | dns_transaction_close_connection(t); | |
827 | ||
828 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
829 | if (r < 0) |
830 | return r; | |
c19ffd9f | 831 | |
519ef046 | 832 | dns_transaction_reset_answer(t); |
be808ea0 | 833 | |
471d40d9 | 834 | return 0; |
c19ffd9f TG |
835 | } |
836 | ||
ec2c5e43 LP |
837 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
838 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
839 | |
840 | assert(s); | |
841 | assert(t); | |
842 | ||
ef7ce6df DM |
843 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
844 | /* Timeout reached? Increase the timeout for the server used */ | |
845 | switch (t->scope->protocol) { | |
49cce12d | 846 | |
ef7ce6df DM |
847 | case DNS_PROTOCOL_DNS: |
848 | assert(t->server); | |
ef7ce6df | 849 | dns_server_packet_lost(t->server, t->current_features, usec - t->start_usec); |
ef7ce6df | 850 | break; |
49cce12d | 851 | |
ef7ce6df DM |
852 | case DNS_PROTOCOL_LLMNR: |
853 | case DNS_PROTOCOL_MDNS: | |
854 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 855 | break; |
49cce12d | 856 | |
ef7ce6df DM |
857 | default: |
858 | assert_not_reached("Invalid DNS protocol."); | |
859 | } | |
860 | ||
861 | if (t->initial_jitter_scheduled) | |
862 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
863 | } |
864 | ||
423659ab LP |
865 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
866 | ||
8d10d620 | 867 | dns_transaction_retry(t); |
ec2c5e43 LP |
868 | return 0; |
869 | } | |
870 | ||
9df3ba6c TG |
871 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
872 | assert(t); | |
873 | assert(t->scope); | |
874 | ||
875 | switch (t->scope->protocol) { | |
49cce12d | 876 | |
9df3ba6c TG |
877 | case DNS_PROTOCOL_DNS: |
878 | assert(t->server); | |
9df3ba6c | 879 | return t->server->resend_timeout; |
49cce12d | 880 | |
9df3ba6c | 881 | case DNS_PROTOCOL_MDNS: |
11a27c2e DM |
882 | assert(t->n_attempts > 0); |
883 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 884 | |
11a27c2e | 885 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 886 | return t->scope->resend_timeout; |
49cce12d | 887 | |
9df3ba6c TG |
888 | default: |
889 | assert_not_reached("Invalid DNS protocol."); | |
890 | } | |
891 | } | |
892 | ||
c842ff24 | 893 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
894 | int r; |
895 | ||
896 | assert(t); | |
897 | ||
f535705a | 898 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 899 | |
ec2c5e43 LP |
900 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
901 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
902 | return 0; | |
903 | } | |
904 | ||
cbe4216d | 905 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
906 | /* If we already tried via a stream, then we don't |
907 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
908 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
909 | return 0; | |
910 | } | |
911 | ||
912 | t->n_attempts++; | |
9df3ba6c | 913 | t->start_usec = ts; |
c61d2b44 LP |
914 | |
915 | dns_transaction_reset_answer(t); | |
ec2c5e43 | 916 | |
0d2cd476 LP |
917 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
918 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 919 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
920 | if (r < 0) |
921 | return r; | |
922 | if (r > 0) { | |
923 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
924 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 925 | t->answer_authenticated = true; |
0d2cd476 LP |
926 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
927 | return 0; | |
928 | } | |
b2b796b8 LP |
929 | |
930 | if (dns_name_is_root(DNS_RESOURCE_KEY_NAME(t->key)) && | |
931 | t->key->type == DNS_TYPE_DS) { | |
932 | ||
933 | /* Hmm, this is a request for the root DS? A | |
934 | * DS RR doesn't exist in the root zone, and | |
935 | * if our trust anchor didn't know it either, | |
936 | * this means we cannot do any DNSSEC logic | |
937 | * anymore. */ | |
938 | ||
1ed8c0fb | 939 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
940 | /* We are in downgrade mode. In this |
941 | * case, synthesize an unsigned empty | |
942 | * response, so that the any lookup | |
943 | * depending on this one can continue | |
944 | * assuming there was no DS, and hence | |
945 | * the root zone was unsigned. */ | |
946 | ||
947 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
948 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
949 | t->answer_authenticated = false; | |
950 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
951 | } else | |
952 | /* If we are not in downgrade mode, | |
953 | * then fail the lookup, because we | |
954 | * cannot reasonably answer it. There | |
955 | * might be DS RRs, but we don't know | |
956 | * them, and the DNS server won't tell | |
957 | * them to us (and even if it would, | |
958 | * we couldn't validate it and trust | |
959 | * it). */ | |
960 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); | |
961 | ||
962 | return 0; | |
963 | } | |
0d2cd476 LP |
964 | } |
965 | ||
966 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 967 | * for probing or verifying a zone item. */ |
547973de | 968 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 969 | |
ae6a4bbf | 970 | r = dns_zone_lookup(&t->scope->zone, t->key, &t->answer, NULL, NULL); |
d746bb3e LP |
971 | if (r < 0) |
972 | return r; | |
973 | if (r > 0) { | |
ae6a4bbf | 974 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 975 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 976 | t->answer_authenticated = true; |
d746bb3e LP |
977 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
978 | return 0; | |
979 | } | |
980 | } | |
981 | ||
4d926a69 LP |
982 | /* Check the cache, but only if this transaction is not used |
983 | * for probing or verifying a zone item. */ | |
547973de | 984 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 985 | |
4d926a69 LP |
986 | /* Before trying the cache, let's make sure we figured out a |
987 | * server to use. Should this cause a change of server this | |
988 | * might flush the cache. */ | |
989 | dns_scope_get_dns_server(t->scope); | |
2c27fbca | 990 | |
4d926a69 LP |
991 | /* Let's then prune all outdated entries */ |
992 | dns_cache_prune(&t->scope->cache); | |
993 | ||
931851e8 | 994 | r = dns_cache_lookup(&t->scope->cache, t->key, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
995 | if (r < 0) |
996 | return r; | |
997 | if (r > 0) { | |
c3bc53e6 | 998 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 999 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1000 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1001 | else | |
3bbdc31d | 1002 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1003 | return 0; |
1004 | } | |
ec2c5e43 LP |
1005 | } |
1006 | ||
1effe965 DM |
1007 | return 1; |
1008 | } | |
1009 | ||
0afa57e2 DM |
1010 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1011 | ||
1012 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1013 | bool add_known_answers = false; |
0afa57e2 DM |
1014 | DnsTransaction *other; |
1015 | unsigned qdcount; | |
1016 | usec_t ts; | |
1017 | int r; | |
1018 | ||
1019 | assert(t); | |
1020 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1021 | ||
e5abebab | 1022 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1023 | t->sent = dns_packet_unref(t->sent); |
1024 | ||
1025 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1026 | if (r < 0) | |
1027 | return r; | |
1028 | ||
1029 | r = dns_packet_append_key(p, t->key, NULL); | |
1030 | if (r < 0) | |
1031 | return r; | |
1032 | ||
1033 | qdcount = 1; | |
1034 | ||
7778dfff DM |
1035 | if (dns_key_is_shared(t->key)) |
1036 | add_known_answers = true; | |
1037 | ||
0afa57e2 DM |
1038 | /* |
1039 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1040 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1041 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1042 | */ | |
1043 | ||
1044 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1045 | ||
1046 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1047 | ||
1048 | /* Skip ourselves */ | |
1049 | if (other == t) | |
1050 | continue; | |
1051 | ||
1052 | if (other->state != DNS_TRANSACTION_PENDING) | |
1053 | continue; | |
1054 | ||
1055 | if (other->next_attempt_after > ts) | |
1056 | continue; | |
1057 | ||
1058 | if (qdcount >= UINT16_MAX) | |
1059 | break; | |
1060 | ||
1061 | r = dns_packet_append_key(p, other->key, NULL); | |
1062 | ||
1063 | /* | |
1064 | * If we can't stuff more questions into the packet, just give up. | |
1065 | * One of the 'other' transactions will fire later and take care of the rest. | |
1066 | */ | |
1067 | if (r == -EMSGSIZE) | |
1068 | break; | |
1069 | ||
1070 | if (r < 0) | |
1071 | return r; | |
1072 | ||
c842ff24 | 1073 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1074 | if (r <= 0) |
1075 | continue; | |
1076 | ||
1077 | ts += transaction_get_resend_timeout(other); | |
1078 | ||
1079 | r = sd_event_add_time( | |
1080 | other->scope->manager->event, | |
1081 | &other->timeout_event_source, | |
1082 | clock_boottime_or_monotonic(), | |
1083 | ts, 0, | |
1084 | on_transaction_timeout, other); | |
1085 | if (r < 0) | |
1086 | return r; | |
1087 | ||
aa4a9deb LP |
1088 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1089 | ||
0afa57e2 DM |
1090 | other->state = DNS_TRANSACTION_PENDING; |
1091 | other->next_attempt_after = ts; | |
1092 | ||
1093 | qdcount ++; | |
7778dfff DM |
1094 | |
1095 | if (dns_key_is_shared(other->key)) | |
1096 | add_known_answers = true; | |
0afa57e2 DM |
1097 | } |
1098 | ||
1099 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1100 | |
7778dfff DM |
1101 | /* Append known answer section if we're asking for any shared record */ |
1102 | if (add_known_answers) { | |
1103 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1104 | if (r < 0) | |
1105 | return r; | |
1106 | } | |
1107 | ||
0afa57e2 DM |
1108 | t->sent = p; |
1109 | p = NULL; | |
1110 | ||
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1115 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1116 | int r; | |
1117 | ||
1118 | assert(t); | |
1119 | ||
1120 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1121 | return dns_transaction_make_packet_mdns(t); | |
1122 | ||
1123 | if (t->sent) | |
1124 | return 0; | |
1125 | ||
b652d4a2 | 1126 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1127 | if (r < 0) |
1128 | return r; | |
1129 | ||
1130 | r = dns_scope_good_key(t->scope, t->key); | |
1131 | if (r < 0) | |
1132 | return r; | |
1133 | if (r == 0) | |
1134 | return -EDOM; | |
1135 | ||
1136 | r = dns_packet_append_key(p, t->key, NULL); | |
1137 | if (r < 0) | |
1138 | return r; | |
1139 | ||
1140 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1141 | DNS_PACKET_HEADER(p)->id = t->id; | |
1142 | ||
1143 | t->sent = p; | |
1144 | p = NULL; | |
1145 | ||
1146 | return 0; | |
1147 | } | |
1148 | ||
1effe965 DM |
1149 | int dns_transaction_go(DnsTransaction *t) { |
1150 | usec_t ts; | |
1151 | int r; | |
1152 | ||
1153 | assert(t); | |
1154 | ||
1155 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
547973de | 1156 | |
c842ff24 | 1157 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1158 | if (r <= 0) |
1159 | return r; | |
1160 | ||
a5784c49 LP |
1161 | log_debug("Excercising transaction %" PRIu16 " for <%s> on scope %s on %s/%s.", |
1162 | t->id, | |
1163 | dns_transaction_key_string(t), | |
1164 | dns_protocol_to_string(t->scope->protocol), | |
1165 | t->scope->link ? t->scope->link->name : "*", | |
1166 | t->scope->family == AF_UNSPEC ? "*" : af_to_name(t->scope->family)); | |
1effe965 | 1167 | |
ef7ce6df | 1168 | if (!t->initial_jitter_scheduled && |
ea12bcc7 DM |
1169 | (t->scope->protocol == DNS_PROTOCOL_LLMNR || |
1170 | t->scope->protocol == DNS_PROTOCOL_MDNS)) { | |
1171 | usec_t jitter, accuracy; | |
6e068472 LP |
1172 | |
1173 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1174 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1175 | ||
ef7ce6df | 1176 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1177 | |
1178 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1179 | |
1180 | switch (t->scope->protocol) { | |
519ef046 | 1181 | |
ea12bcc7 DM |
1182 | case DNS_PROTOCOL_LLMNR: |
1183 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1184 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1185 | break; | |
519ef046 | 1186 | |
ea12bcc7 DM |
1187 | case DNS_PROTOCOL_MDNS: |
1188 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1189 | jitter += MDNS_JITTER_MIN_USEC; | |
1190 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1191 | break; | |
1192 | default: | |
1193 | assert_not_reached("bad protocol"); | |
1194 | } | |
6e068472 LP |
1195 | |
1196 | r = sd_event_add_time( | |
1197 | t->scope->manager->event, | |
1198 | &t->timeout_event_source, | |
1199 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1200 | ts + jitter, accuracy, |
6e068472 LP |
1201 | on_transaction_timeout, t); |
1202 | if (r < 0) | |
1203 | return r; | |
1204 | ||
aa4a9deb LP |
1205 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1206 | ||
6e068472 | 1207 | t->n_attempts = 0; |
a9da14e1 | 1208 | t->next_attempt_after = ts; |
6e068472 LP |
1209 | t->state = DNS_TRANSACTION_PENDING; |
1210 | ||
ea12bcc7 | 1211 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1212 | return 0; |
1213 | } | |
1214 | ||
ec2c5e43 LP |
1215 | /* Otherwise, we need to ask the network */ |
1216 | r = dns_transaction_make_packet(t); | |
1217 | if (r == -EDOM) { | |
1218 | /* Not the right request to make on this network? | |
1219 | * (i.e. an A request made on IPv6 or an AAAA request | |
1220 | * made on IPv4, on LLMNR or mDNS.) */ | |
1221 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1222 | return 0; | |
1223 | } | |
1224 | if (r < 0) | |
1225 | return r; | |
1226 | ||
1227 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
f52e61da LP |
1228 | (dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "in-addr.arpa") > 0 || |
1229 | dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1230 | |
1231 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1232 | * always be made via TCP on LLMNR */ | |
1233 | r = dns_transaction_open_tcp(t); | |
1234 | } else { | |
be808ea0 TG |
1235 | /* Try via UDP, and if that fails due to large size or lack of |
1236 | * support try via TCP */ | |
49cce12d | 1237 | r = dns_transaction_emit_udp(t); |
be808ea0 | 1238 | if (r == -EMSGSIZE || r == -EAGAIN) |
ec2c5e43 LP |
1239 | r = dns_transaction_open_tcp(t); |
1240 | } | |
be808ea0 | 1241 | |
ec2c5e43 LP |
1242 | if (r == -ESRCH) { |
1243 | /* No servers to send this to? */ | |
1244 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1245 | return 0; | |
8300ba21 | 1246 | } else if (r < 0) { |
13b551ac LP |
1247 | if (t->scope->protocol != DNS_PROTOCOL_DNS) { |
1248 | dns_transaction_complete(t, DNS_TRANSACTION_RESOURCES); | |
1249 | return 0; | |
1250 | } | |
1251 | ||
ec2c5e43 | 1252 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1253 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1254 | |
1255 | return dns_transaction_go(t); | |
1256 | } | |
1257 | ||
a9da14e1 DM |
1258 | ts += transaction_get_resend_timeout(t); |
1259 | ||
9a015429 LP |
1260 | r = sd_event_add_time( |
1261 | t->scope->manager->event, | |
1262 | &t->timeout_event_source, | |
1263 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1264 | ts, 0, |
9a015429 | 1265 | on_transaction_timeout, t); |
ec2c5e43 LP |
1266 | if (r < 0) |
1267 | return r; | |
1268 | ||
aa4a9deb LP |
1269 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1270 | ||
ec2c5e43 | 1271 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1272 | t->next_attempt_after = ts; |
1273 | ||
ec2c5e43 LP |
1274 | return 1; |
1275 | } | |
1276 | ||
f2992dc1 LP |
1277 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1278 | DnsTransaction *n; | |
1279 | Iterator i; | |
1280 | int r; | |
1281 | ||
1282 | assert(t); | |
1283 | assert(aux); | |
1284 | ||
1285 | /* Try to find cyclic dependencies between transaction objects */ | |
1286 | ||
1287 | if (t == aux) | |
1288 | return 1; | |
1289 | ||
3eb6aa00 | 1290 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1291 | r = dns_transaction_find_cyclic(t, n); |
1292 | if (r != 0) | |
1293 | return r; | |
1294 | } | |
1295 | ||
3eb6aa00 | 1296 | return 0; |
f2992dc1 LP |
1297 | } |
1298 | ||
547973de LP |
1299 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1300 | DnsTransaction *aux; | |
1301 | int r; | |
1302 | ||
1303 | assert(t); | |
1304 | assert(ret); | |
1305 | assert(key); | |
1306 | ||
1307 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1308 | if (!aux) { | |
1309 | r = dns_transaction_new(&aux, t->scope, key); | |
1310 | if (r < 0) | |
1311 | return r; | |
1312 | } else { | |
1313 | if (set_contains(t->dnssec_transactions, aux)) { | |
1314 | *ret = aux; | |
1315 | return 0; | |
1316 | } | |
f2992dc1 LP |
1317 | |
1318 | r = dns_transaction_find_cyclic(t, aux); | |
1319 | if (r < 0) | |
1320 | return r; | |
1321 | if (r > 0) { | |
1322 | log_debug("Detected potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
1323 | aux->id, | |
1324 | strna(dns_transaction_key_string(aux)), | |
1325 | t->id, | |
1326 | strna(dns_transaction_key_string(t))); | |
1327 | return -ELOOP; | |
1328 | } | |
547973de LP |
1329 | } |
1330 | ||
1331 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1332 | if (r < 0) | |
1333 | goto gc; | |
1334 | ||
1335 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1336 | if (r < 0) | |
1337 | goto gc; | |
1338 | ||
1339 | r = set_put(t->dnssec_transactions, aux); | |
1340 | if (r < 0) | |
1341 | goto gc; | |
1342 | ||
1343 | r = set_put(aux->notify_transactions, t); | |
1344 | if (r < 0) { | |
1345 | (void) set_remove(t->dnssec_transactions, aux); | |
1346 | goto gc; | |
1347 | } | |
1348 | ||
1349 | *ret = aux; | |
1350 | return 1; | |
1351 | ||
1352 | gc: | |
1353 | dns_transaction_gc(aux); | |
1354 | return r; | |
1355 | } | |
1356 | ||
1357 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1358 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1359 | DnsTransaction *aux; | |
1360 | int r; | |
1361 | ||
1362 | assert(t); | |
1363 | assert(key); | |
1364 | ||
1365 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1366 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1367 | if (r < 0) |
1368 | return r; | |
1369 | if (r > 0) { | |
1370 | r = dns_answer_extend(&t->validated_keys, a); | |
1371 | if (r < 0) | |
1372 | return r; | |
1373 | ||
1374 | return 0; | |
1375 | } | |
1376 | ||
1377 | /* This didn't work, ask for it via the network/cache then. */ | |
1378 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1379 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1380 | return 0; | |
547973de LP |
1381 | if (r < 0) |
1382 | return r; | |
1383 | ||
1384 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1385 | r = dns_transaction_go(aux); | |
1386 | if (r < 0) | |
1387 | return r; | |
1388 | } | |
1389 | ||
f2992dc1 | 1390 | return 1; |
547973de LP |
1391 | } |
1392 | ||
105e1512 LP |
1393 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
1394 | int r; | |
1395 | ||
1396 | assert(t); | |
1397 | ||
1398 | /* Checks whether the answer is positive, i.e. either a direct | |
1399 | * answer to the question, or a CNAME/DNAME for it */ | |
1400 | ||
1401 | r = dns_answer_match_key(t->answer, t->key, flags); | |
1402 | if (r != 0) | |
1403 | return r; | |
1404 | ||
1405 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
1406 | if (r != 0) | |
1407 | return r; | |
1408 | ||
1409 | return false; | |
1410 | } | |
1411 | ||
8a516214 LP |
1412 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1413 | int r; | |
1414 | ||
1415 | assert(t); | |
1416 | ||
1417 | /* Check whether the specified name is in the the NTA | |
1418 | * database, either in the global one, or the link-local | |
1419 | * one. */ | |
1420 | ||
1421 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1422 | if (r != 0) | |
1423 | return r; | |
1424 | ||
1425 | if (!t->scope->link) | |
1426 | return 0; | |
1427 | ||
1428 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1429 | } | |
1430 | ||
105e1512 LP |
1431 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1432 | int r; | |
1433 | ||
1434 | assert(t); | |
1435 | ||
1436 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1437 | * RRs to prove it */ | |
1438 | ||
1439 | r = dns_transaction_has_positive_answer(t, NULL); | |
1440 | if (r < 0) | |
1441 | return r; | |
1442 | if (r > 0) | |
1443 | return false; | |
1444 | ||
8e54f5d9 LP |
1445 | /* Is this key explicitly listed as a negative trust anchor? |
1446 | * If so, it's nothing we need to care about */ | |
8a516214 | 1447 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); |
8e54f5d9 LP |
1448 | if (r < 0) |
1449 | return r; | |
1450 | if (r > 0) | |
1451 | return false; | |
1452 | ||
105e1512 LP |
1453 | /* The answer does not contain any RRs that match to the |
1454 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1455 | * included. If not, the answer is unsigned. */ | |
1456 | ||
1457 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1458 | if (r < 0) | |
1459 | return r; | |
1460 | if (r > 0) | |
1461 | return false; | |
1462 | ||
1463 | return true; | |
1464 | } | |
1465 | ||
1466 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1467 | int r; | |
1468 | ||
1469 | assert(t); | |
1470 | assert(rr); | |
1471 | ||
1472 | /* Check if the specified RR is the "primary" response, | |
1473 | * i.e. either matches the question precisely or is a | |
1474 | * CNAME/DNAME for it, or is any kind of NSEC/NSEC3 RR */ | |
1475 | ||
1476 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1477 | if (r != 0) | |
1478 | return r; | |
1479 | ||
1480 | r = dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); | |
1481 | if (r != 0) | |
1482 | return r; | |
1483 | ||
1484 | if (rr->key->type == DNS_TYPE_NSEC3) { | |
1485 | const char *p; | |
1486 | ||
1487 | p = DNS_RESOURCE_KEY_NAME(rr->key); | |
1488 | r = dns_name_parent(&p); | |
1489 | if (r < 0) | |
1490 | return r; | |
1491 | if (r > 0) { | |
1492 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), p); | |
1493 | if (r < 0) | |
1494 | return r; | |
1495 | if (r > 0) | |
1496 | return true; | |
1497 | } | |
1498 | } | |
1499 | ||
1500 | return rr->key->type == DNS_TYPE_NSEC; | |
1501 | } | |
1502 | ||
547973de LP |
1503 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1504 | DnsResourceRecord *rr; | |
105e1512 | 1505 | |
547973de LP |
1506 | int r; |
1507 | ||
1508 | assert(t); | |
1509 | ||
105e1512 LP |
1510 | /* |
1511 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1512 | * we can verify signatures or prove that RRs are rightfully | |
1513 | * unsigned. Specifically: | |
1514 | * | |
1515 | * - For RRSIG we get the matching DNSKEY | |
1516 | * - For DNSKEY we get the matching DS | |
1517 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1518 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 LP |
1519 | * - For other unsigned RRs we get the matching SOA RR |
1520 | * - For SOA/NS/DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
1521 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR | |
1522 | */ | |
1523 | ||
b652d4a2 | 1524 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
1525 | return 0; |
1526 | ||
b652d4a2 LP |
1527 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO) |
1528 | return 0; /* Server doesn't do DNSSEC, there's no point in requesting any RRs then. */ | |
1529 | if (t->server && t->server->rrsig_missing) | |
1530 | return 0; /* Server handles DNSSEC requests, but isn't augmenting responses with RRSIGs. No point in trying DNSSEC then. */ | |
1531 | ||
547973de LP |
1532 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1533 | ||
105e1512 LP |
1534 | if (dns_type_is_pseudo(rr->key->type)) |
1535 | continue; | |
1536 | ||
8e54f5d9 | 1537 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
8a516214 | 1538 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
1539 | if (r < 0) |
1540 | return r; | |
1541 | if (r > 0) | |
1542 | continue; | |
1543 | ||
547973de LP |
1544 | switch (rr->key->type) { |
1545 | ||
1546 | case DNS_TYPE_RRSIG: { | |
1547 | /* For each RRSIG we request the matching DNSKEY */ | |
1548 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1549 | ||
1550 | /* If this RRSIG is about a DNSKEY RR and the | |
1551 | * signer is the same as the owner, then we | |
1552 | * already have the DNSKEY, and we don't have | |
1553 | * to look for more. */ | |
1554 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1555 | r = dns_name_equal(rr->rrsig.signer, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1556 | if (r < 0) | |
1557 | return r; | |
1558 | if (r > 0) | |
1559 | continue; | |
1560 | } | |
1561 | ||
105e1512 LP |
1562 | /* If the signer is not a parent of our |
1563 | * original query, then this is about an | |
1564 | * auxiliary RRset, but not anything we asked | |
1565 | * for. In this case we aren't interested, | |
1566 | * because we don't want to request additional | |
1567 | * RRs for stuff we didn't really ask for, and | |
1568 | * also to avoid request loops, where | |
1569 | * additional RRs from one transaction result | |
1570 | * in another transaction whose additonal RRs | |
1571 | * point back to the original transaction, and | |
1572 | * we deadlock. */ | |
1573 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), rr->rrsig.signer); | |
547973de LP |
1574 | if (r < 0) |
1575 | return r; | |
1576 | if (r == 0) | |
1577 | continue; | |
1578 | ||
1579 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
1580 | if (!dnskey) | |
1581 | return -ENOMEM; | |
1582 | ||
105e1512 | 1583 | 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 |
1584 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
1585 | if (r < 0) | |
1586 | return r; | |
1587 | break; | |
1588 | } | |
1589 | ||
1590 | case DNS_TYPE_DNSKEY: { | |
1591 | /* For each DNSKEY we request the matching DS */ | |
1592 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1593 | ||
105e1512 LP |
1594 | /* If the DNSKEY we are looking at is not for |
1595 | * zone we are interested in, nor any of its | |
1596 | * parents, we aren't interested, and don't | |
1597 | * request it. After all, we don't want to end | |
1598 | * up in request loops, and want to keep | |
1599 | * additional traffic down. */ | |
1600 | ||
1601 | r = dns_name_endswith(DNS_RESOURCE_KEY_NAME(t->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1602 | if (r < 0) | |
1603 | return r; | |
1604 | if (r == 0) | |
1605 | continue; | |
1606 | ||
547973de LP |
1607 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); |
1608 | if (!ds) | |
1609 | return -ENOMEM; | |
1610 | ||
0c857028 | 1611 | 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 |
1612 | r = dns_transaction_request_dnssec_rr(t, ds); |
1613 | if (r < 0) | |
1614 | return r; | |
547973de | 1615 | |
105e1512 LP |
1616 | break; |
1617 | } | |
1618 | ||
105e1512 LP |
1619 | case DNS_TYPE_SOA: |
1620 | case DNS_TYPE_NS: { | |
1621 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
1622 | ||
1623 | /* For an unsigned SOA or NS, try to acquire | |
1624 | * the matching DS RR, as we are at a zone cut | |
1625 | * then, and whether a DS exists tells us | |
1626 | * whether the zone is signed. Do so only if | |
1627 | * this RR matches our original question, | |
1628 | * however. */ | |
1629 | ||
1630 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1631 | if (r < 0) | |
1632 | return r; | |
1633 | if (r == 0) | |
1634 | continue; | |
1635 | ||
1636 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1637 | if (r < 0) | |
1638 | return r; | |
1639 | if (r > 0) | |
1640 | continue; | |
1641 | ||
1642 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1643 | if (!ds) | |
1644 | return -ENOMEM; | |
1645 | ||
1646 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", t->id, DNS_RESOURCE_KEY_NAME(rr->key)); | |
547973de LP |
1647 | r = dns_transaction_request_dnssec_rr(t, ds); |
1648 | if (r < 0) | |
1649 | return r; | |
1650 | ||
1651 | break; | |
105e1512 LP |
1652 | } |
1653 | ||
b63fca62 | 1654 | case DNS_TYPE_DS: |
105e1512 LP |
1655 | case DNS_TYPE_CNAME: |
1656 | case DNS_TYPE_DNAME: { | |
1657 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1658 | const char *name; | |
1659 | ||
1660 | /* CNAMEs and DNAMEs cannot be located at a | |
1661 | * zone apex, hence ask for the parent SOA for | |
1662 | * unsigned CNAME/DNAME RRs, maybe that's the | |
1663 | * apex. But do all that only if this is | |
1664 | * actually a response to our original | |
b63fca62 LP |
1665 | * question. |
1666 | * | |
1667 | * Similar for DS RRs, which are signed when | |
1668 | * the parent SOA is signed. */ | |
105e1512 LP |
1669 | |
1670 | r = dns_transaction_is_primary_response(t, rr); | |
1671 | if (r < 0) | |
1672 | return r; | |
1673 | if (r == 0) | |
1674 | continue; | |
1675 | ||
1676 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1677 | if (r < 0) | |
1678 | return r; | |
1679 | if (r > 0) | |
1680 | continue; | |
1681 | ||
1682 | name = DNS_RESOURCE_KEY_NAME(rr->key); | |
1683 | r = dns_name_parent(&name); | |
1684 | if (r < 0) | |
1685 | return r; | |
1686 | if (r == 0) | |
1687 | continue; | |
1688 | ||
1689 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
1690 | if (!soa) | |
1691 | return -ENOMEM; | |
1692 | ||
b63fca62 | 1693 | 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 |
1694 | r = dns_transaction_request_dnssec_rr(t, soa); |
1695 | if (r < 0) | |
1696 | return r; | |
1697 | ||
1698 | break; | |
1699 | } | |
1700 | ||
1701 | default: { | |
1702 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1703 | ||
b63fca62 LP |
1704 | /* For other unsigned RRsets (including |
1705 | * NSEC/NSEC3!), look for proof the zone is | |
1706 | * unsigned, by requesting the SOA RR of the | |
1707 | * zone. However, do so only if they are | |
1708 | * directly relevant to our original | |
105e1512 LP |
1709 | * question. */ |
1710 | ||
1711 | r = dns_transaction_is_primary_response(t, rr); | |
1712 | if (r < 0) | |
1713 | return r; | |
1714 | if (r == 0) | |
1715 | continue; | |
1716 | ||
1717 | r = dnssec_has_rrsig(t->answer, rr->key); | |
1718 | if (r < 0) | |
1719 | return r; | |
1720 | if (r > 0) | |
1721 | continue; | |
1722 | ||
1723 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, DNS_RESOURCE_KEY_NAME(rr->key)); | |
1724 | if (!soa) | |
1725 | return -ENOMEM; | |
1726 | ||
db5b0e92 | 1727 | 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 |
1728 | r = dns_transaction_request_dnssec_rr(t, soa); |
1729 | if (r < 0) | |
1730 | return r; | |
1731 | break; | |
547973de LP |
1732 | }} |
1733 | } | |
1734 | ||
105e1512 LP |
1735 | /* Above, we requested everything necessary to validate what |
1736 | * we got. Now, let's request what we need to validate what we | |
1737 | * didn't get... */ | |
1738 | ||
1739 | r = dns_transaction_has_unsigned_negative_answer(t); | |
1740 | if (r < 0) | |
1741 | return r; | |
1742 | if (r > 0) { | |
1743 | const char *name; | |
1744 | ||
1745 | name = DNS_RESOURCE_KEY_NAME(t->key); | |
1746 | ||
1747 | /* If this was a SOA or NS request, then this | |
1748 | * indicates that we are not at a zone apex, hence ask | |
1749 | * the parent name instead. If this was a DS request, | |
1750 | * then it's signed when the parent zone is signed, | |
1751 | * hence ask the parent in that case, too. */ | |
1752 | ||
1753 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
1754 | r = dns_name_parent(&name); | |
1755 | if (r < 0) | |
1756 | return r; | |
1757 | if (r > 0) | |
1758 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1759 | else | |
1760 | name = NULL; | |
1761 | } else | |
1762 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", t->id, DNS_RESOURCE_KEY_NAME(t->key)); | |
1763 | ||
1764 | if (name) { | |
1765 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
1766 | ||
1767 | soa = dns_resource_key_new(t->key->class, DNS_TYPE_SOA, name); | |
1768 | if (!soa) | |
1769 | return -ENOMEM; | |
1770 | ||
1771 | r = dns_transaction_request_dnssec_rr(t, soa); | |
1772 | if (r < 0) | |
1773 | return r; | |
1774 | } | |
1775 | } | |
1776 | ||
1777 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
1778 | } |
1779 | ||
1780 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
1781 | int r; | |
1782 | ||
1783 | assert(t); | |
547973de LP |
1784 | assert(source); |
1785 | ||
105e1512 LP |
1786 | if (!IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)) |
1787 | return; | |
1788 | ||
547973de | 1789 | /* Invoked whenever any of our auxiliary DNSSEC transactions |
105e1512 LP |
1790 | completed its work. We copy any RRs from that transaction |
1791 | over into our list of validated keys -- but only if the | |
1792 | answer is authenticated. | |
1793 | ||
1794 | Note that we fail our transaction if the auxiliary | |
1795 | transaction failed, except on NXDOMAIN. This is because | |
1796 | some broken DNS servers (Akamai...) will return NXDOMAIN | |
1797 | for empty non-terminals. */ | |
1798 | ||
6773896e | 1799 | switch (source->state) { |
547973de | 1800 | |
6773896e LP |
1801 | case DNS_TRANSACTION_DNSSEC_FAILED: |
1802 | ||
1803 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(source->answer_dnssec_result)); | |
1804 | t->answer_dnssec_result = source->answer_dnssec_result; /* Copy error code over */ | |
1805 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
1806 | break; | |
1807 | ||
1808 | case DNS_TRANSACTION_RCODE_FAILURE: | |
1809 | ||
1810 | if (source->answer_rcode != DNS_RCODE_NXDOMAIN) { | |
1811 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%i.", source->answer_rcode); | |
105e1512 | 1812 | goto fail; |
547973de | 1813 | } |
547973de | 1814 | |
6773896e LP |
1815 | /* fall-through: NXDOMAIN is good enough for us */ |
1816 | ||
1817 | case DNS_TRANSACTION_SUCCESS: | |
1818 | if (source->answer_authenticated) { | |
1819 | r = dns_answer_extend(&t->validated_keys, source->answer); | |
1820 | if (r < 0) { | |
1821 | log_error_errno(r, "Failed to merge validated DNSSEC key data: %m"); | |
1822 | goto fail; | |
1823 | } | |
1824 | } | |
1825 | ||
1826 | /* If the state is still PENDING, we are still in the loop | |
1827 | * that adds further DNSSEC transactions, hence don't check if | |
1828 | * we are ready yet. If the state is VALIDATING however, we | |
1829 | * should check if we are complete now. */ | |
1830 | if (t->state == DNS_TRANSACTION_VALIDATING) | |
1831 | dns_transaction_process_dnssec(t); | |
1832 | break; | |
1833 | ||
1834 | default: | |
1835 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(source->state)); | |
1836 | goto fail; | |
1837 | } | |
105e1512 LP |
1838 | |
1839 | return; | |
1840 | ||
1841 | fail: | |
019036a4 | 1842 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; |
105e1512 | 1843 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
547973de LP |
1844 | } |
1845 | ||
105e1512 LP |
1846 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
1847 | DnsResourceRecord *rr; | |
1848 | int ifindex, r; | |
1849 | ||
1850 | assert(t); | |
1851 | ||
1852 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
1853 | * RRs from the list of validated keys to the list of | |
1854 | * validated keys. */ | |
1855 | ||
1856 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
1857 | ||
1858 | r = dnssec_verify_dnskey_search(rr, t->validated_keys); | |
1859 | if (r < 0) | |
1860 | return r; | |
1861 | if (r == 0) | |
1862 | continue; | |
1863 | ||
1864 | /* If so, the DNSKEY is validated too. */ | |
1865 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
1866 | if (r < 0) | |
1867 | return r; | |
1868 | } | |
1869 | ||
1870 | return 0; | |
1871 | } | |
1872 | ||
1873 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
1874 | int r; |
1875 | ||
1876 | assert(t); | |
1877 | assert(rr); | |
1878 | ||
105e1512 LP |
1879 | /* Checks if the RR we are looking for must be signed with an |
1880 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 1881 | |
b652d4a2 | 1882 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 1883 | return false; |
56352fe9 | 1884 | |
105e1512 LP |
1885 | if (dns_type_is_pseudo(rr->key->type)) |
1886 | return -EINVAL; | |
56352fe9 | 1887 | |
8a516214 | 1888 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
1889 | if (r < 0) |
1890 | return r; | |
1891 | if (r > 0) | |
1892 | return false; | |
1893 | ||
105e1512 | 1894 | switch (rr->key->type) { |
56352fe9 | 1895 | |
105e1512 LP |
1896 | case DNS_TYPE_RRSIG: |
1897 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
1898 | return false; | |
1899 | ||
1900 | case DNS_TYPE_SOA: | |
1901 | case DNS_TYPE_NS: { | |
1902 | DnsTransaction *dt; | |
1903 | Iterator i; | |
1904 | ||
b63fca62 | 1905 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
1906 | |
1907 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1908 | ||
1909 | if (dt->key->class != rr->key->class) | |
1910 | continue; | |
1911 | if (dt->key->type != DNS_TYPE_DS) | |
1912 | continue; | |
1913 | ||
1914 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1915 | if (r < 0) | |
1916 | return r; | |
1917 | if (r == 0) | |
1918 | continue; | |
1919 | ||
1920 | /* We found a DS transactions for the SOA/NS | |
1921 | * RRs we are looking at. If it discovered signed DS | |
1922 | * RRs, then we need to be signed, too. */ | |
1923 | ||
097a2517 TA |
1924 | if (!dt->answer_authenticated) |
1925 | return false; | |
105e1512 | 1926 | |
097a2517 | 1927 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
1928 | } |
1929 | ||
1930 | /* We found nothing that proves this is safe to leave | |
1931 | * this unauthenticated, hence ask inist on | |
1932 | * authentication. */ | |
1933 | return true; | |
1934 | } | |
1935 | ||
b63fca62 | 1936 | case DNS_TYPE_DS: |
105e1512 LP |
1937 | case DNS_TYPE_CNAME: |
1938 | case DNS_TYPE_DNAME: { | |
1939 | const char *parent = NULL; | |
1940 | DnsTransaction *dt; | |
1941 | Iterator i; | |
1942 | ||
b63fca62 LP |
1943 | /* |
1944 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
1945 | * | |
1946 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
1947 | */ | |
105e1512 LP |
1948 | |
1949 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1950 | ||
1951 | if (dt->key->class != rr->key->class) | |
1952 | continue; | |
1953 | if (dt->key->type != DNS_TYPE_SOA) | |
1954 | continue; | |
1955 | ||
1956 | if (!parent) { | |
1957 | parent = DNS_RESOURCE_KEY_NAME(rr->key); | |
1958 | r = dns_name_parent(&parent); | |
1959 | if (r < 0) | |
1960 | return r; | |
1961 | if (r == 0) { | |
b63fca62 LP |
1962 | if (rr->key->type == DNS_TYPE_DS) |
1963 | return true; | |
1964 | ||
105e1512 LP |
1965 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
1966 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
1967 | return -EBADMSG; | |
1968 | } | |
1969 | } | |
1970 | ||
1971 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), parent); | |
1972 | if (r < 0) | |
1973 | return r; | |
1974 | if (r == 0) | |
1975 | continue; | |
1976 | ||
1977 | return t->answer_authenticated; | |
1978 | } | |
1979 | ||
1980 | return true; | |
1981 | } | |
1982 | ||
1983 | default: { | |
1984 | DnsTransaction *dt; | |
1985 | Iterator i; | |
1986 | ||
b63fca62 | 1987 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
1988 | |
1989 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
1990 | ||
1991 | if (dt->key->class != rr->key->class) | |
1992 | continue; | |
1993 | if (dt->key->type != DNS_TYPE_SOA) | |
1994 | continue; | |
1995 | ||
1996 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), DNS_RESOURCE_KEY_NAME(rr->key)); | |
1997 | if (r < 0) | |
1998 | return r; | |
1999 | if (r == 0) | |
2000 | continue; | |
2001 | ||
2002 | /* We found the transaction that was supposed to find | |
2003 | * the SOA RR for us. It was successful, but found no | |
2004 | * RR for us. This means we are not at a zone cut. In | |
2005 | * this case, we require authentication if the SOA | |
2006 | * lookup was authenticated too. */ | |
2007 | return t->answer_authenticated; | |
2008 | } | |
2009 | ||
2010 | return true; | |
2011 | }} | |
56352fe9 LP |
2012 | } |
2013 | ||
d33b6cf3 LP |
2014 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2015 | DnsTransaction *dt; | |
2016 | const char *tld; | |
2017 | Iterator i; | |
2018 | int r; | |
2019 | ||
2020 | /* If DNSSEC downgrade mode is on, checks whether the | |
2021 | * specified RR is one level below a TLD we have proven not to | |
2022 | * exist. In such a case we assume that this is a private | |
2023 | * domain, and permit it. | |
2024 | * | |
2025 | * This detects cases like the Fritz!Box router networks. Each | |
2026 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2027 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2028 | * are served by the router itself, while requests for the | |
2029 | * "box" domain will result in NXDOMAIN. | |
2030 | * | |
2031 | * Note that this logic is unable to detect cases where a | |
2032 | * router serves a private DNS zone directly under | |
2033 | * non-existing TLD. In such a case we cannot detect whether | |
2034 | * the TLD is supposed to exist or not, as all requests we | |
2035 | * make for it will be answered by the router's zone, and not | |
2036 | * by the root zone. */ | |
2037 | ||
2038 | assert(t); | |
2039 | ||
2040 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2041 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2042 | ||
2043 | tld = DNS_RESOURCE_KEY_NAME(key); | |
2044 | r = dns_name_parent(&tld); | |
2045 | if (r < 0) | |
2046 | return r; | |
2047 | if (r == 0) | |
2048 | return false; /* Already the root domain */ | |
2049 | ||
2050 | if (!dns_name_is_single_label(tld)) | |
2051 | return false; | |
2052 | ||
2053 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2054 | ||
2055 | if (dt->key->class != key->class) | |
2056 | continue; | |
2057 | ||
2058 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), tld); | |
2059 | if (r < 0) | |
2060 | return r; | |
2061 | if (r == 0) | |
2062 | continue; | |
2063 | ||
2064 | /* We found an auxiliary lookup we did for the TLD. If | |
2065 | * that returned with NXDOMAIN, we know the TLD didn't | |
2066 | * exist, and hence this might be a private zone. */ | |
2067 | ||
2068 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2069 | } | |
2070 | ||
2071 | return false; | |
2072 | } | |
2073 | ||
105e1512 LP |
2074 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
2075 | DnsTransaction *dt; | |
2076 | const char *name; | |
2077 | Iterator i; | |
2078 | int r; | |
56352fe9 LP |
2079 | |
2080 | assert(t); | |
2081 | ||
105e1512 LP |
2082 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2083 | * this negative reply */ | |
56352fe9 | 2084 | |
b652d4a2 | 2085 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2086 | return false; |
56352fe9 | 2087 | |
105e1512 LP |
2088 | if (dns_type_is_pseudo(t->key->type)) |
2089 | return -EINVAL; | |
2090 | ||
8a516214 | 2091 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(t->key)); |
8e54f5d9 LP |
2092 | if (r < 0) |
2093 | return r; | |
2094 | if (r > 0) | |
2095 | return false; | |
2096 | ||
d33b6cf3 LP |
2097 | r = dns_transaction_in_private_tld(t, t->key); |
2098 | if (r < 0) | |
2099 | return r; | |
2100 | if (r > 0) { | |
2101 | /* The lookup is from a TLD that is proven not to | |
2102 | * exist, and we are in downgrade mode, hence ignore | |
2103 | * that fact that we didn't get any NSEC RRs.*/ | |
2104 | ||
2105 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", dns_transaction_key_string(t)); | |
2106 | return false; | |
2107 | } | |
2108 | ||
105e1512 LP |
2109 | name = DNS_RESOURCE_KEY_NAME(t->key); |
2110 | ||
2111 | if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS, DNS_TYPE_DS)) { | |
2112 | ||
2113 | /* We got a negative reply for this SOA/NS lookup? If | |
2114 | * so, then we are not at a zone apex, and thus should | |
2115 | * look at the result of the parent SOA lookup. | |
2116 | * | |
2117 | * We got a negative reply for this DS lookup? DS RRs | |
2118 | * are signed when their parent zone is signed, hence | |
2119 | * also check the parent SOA in this case. */ | |
2120 | ||
2121 | r = dns_name_parent(&name); | |
56352fe9 LP |
2122 | if (r < 0) |
2123 | return r; | |
2124 | if (r == 0) | |
105e1512 LP |
2125 | return true; |
2126 | } | |
2127 | ||
2128 | /* For all other RRs we check the SOA on the same level to see | |
2129 | * if it's signed. */ | |
2130 | ||
2131 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2132 | ||
2133 | if (dt->key->class != t->key->class) | |
2134 | continue; | |
2135 | if (dt->key->type != DNS_TYPE_SOA) | |
56352fe9 LP |
2136 | continue; |
2137 | ||
105e1512 | 2138 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), name); |
56352fe9 LP |
2139 | if (r < 0) |
2140 | return r; | |
105e1512 LP |
2141 | if (r == 0) |
2142 | continue; | |
2143 | ||
2144 | return dt->answer_authenticated; | |
56352fe9 LP |
2145 | } |
2146 | ||
105e1512 LP |
2147 | /* If in doubt, require NSEC/NSEC3 */ |
2148 | return true; | |
56352fe9 LP |
2149 | } |
2150 | ||
94aa7071 LP |
2151 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2152 | DnsResourceRecord *rrsig; | |
2153 | bool found = false; | |
2154 | int r; | |
2155 | ||
2156 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2157 | * the specified RRset is authenticated (i.e. has a matching | |
2158 | * DS RR). */ | |
2159 | ||
8a516214 | 2160 | r = dns_transaction_negative_trust_anchor_lookup(t, DNS_RESOURCE_KEY_NAME(rr->key)); |
8e54f5d9 LP |
2161 | if (r < 0) |
2162 | return r; | |
2163 | if (r > 0) | |
2164 | return false; | |
2165 | ||
94aa7071 LP |
2166 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2167 | DnsTransaction *dt; | |
2168 | Iterator i; | |
2169 | ||
2170 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2171 | if (r < 0) | |
2172 | return r; | |
2173 | if (r == 0) | |
2174 | continue; | |
2175 | ||
2176 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2177 | ||
2178 | if (dt->key->class != rr->key->class) | |
2179 | continue; | |
2180 | ||
2181 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2182 | ||
2183 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2184 | if (r < 0) | |
2185 | return r; | |
2186 | if (r == 0) | |
2187 | continue; | |
2188 | ||
2189 | /* OK, we found an auxiliary DNSKEY | |
2190 | * lookup. If that lookup is | |
2191 | * authenticated, report this. */ | |
2192 | ||
2193 | if (dt->answer_authenticated) | |
2194 | return true; | |
2195 | ||
2196 | found = true; | |
2197 | ||
2198 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2199 | ||
2200 | r = dns_name_equal(DNS_RESOURCE_KEY_NAME(dt->key), rrsig->rrsig.signer); | |
2201 | if (r < 0) | |
2202 | return r; | |
2203 | if (r == 0) | |
2204 | continue; | |
2205 | ||
2206 | /* OK, we found an auxiliary DS | |
2207 | * lookup. If that lookup is | |
2208 | * authenticated and non-zero, we | |
2209 | * won! */ | |
2210 | ||
2211 | if (!dt->answer_authenticated) | |
2212 | return false; | |
2213 | ||
2214 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2215 | } | |
2216 | } | |
2217 | } | |
2218 | ||
2219 | return found ? false : -ENXIO; | |
2220 | } | |
2221 | ||
b652d4a2 LP |
2222 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2223 | assert(t); | |
2224 | assert(rr); | |
2225 | ||
2226 | /* We know that the root domain is signed, hence if it appears | |
2227 | * not to be signed, there's a problem with the DNS server */ | |
2228 | ||
2229 | return rr->key->class == DNS_CLASS_IN && | |
2230 | dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key)); | |
2231 | } | |
2232 | ||
0f87f3e8 LP |
2233 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2234 | DnsResourceRecord *rr; | |
2235 | int r; | |
2236 | ||
2237 | assert(t); | |
2238 | ||
2239 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2240 | * for a key from our trust anchor. Note that we don't care | |
2241 | * whether the DNSKEY can be authenticated or not. It's | |
2242 | * sufficient if it is self-signed. */ | |
2243 | ||
2244 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2245 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2246 | if (r < 0) |
2247 | return r; | |
2248 | } | |
2249 | ||
2250 | return 0; | |
2251 | } | |
2252 | ||
c9c72065 LP |
2253 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2254 | bool changed; | |
2255 | int r; | |
2256 | ||
2257 | assert(t); | |
2258 | ||
2259 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2260 | * our trust anchors database considers revoked. */ | |
2261 | ||
2262 | do { | |
2263 | DnsResourceRecord *rr; | |
2264 | ||
2265 | changed = false; | |
2266 | ||
2267 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2268 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2269 | if (r < 0) | |
2270 | return r; | |
2271 | if (r > 0) { | |
2272 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2273 | if (r < 0) | |
2274 | return r; | |
2275 | ||
2276 | assert(r > 0); | |
2277 | changed = true; | |
2278 | break; | |
2279 | } | |
2280 | } | |
2281 | } while (changed); | |
2282 | ||
2283 | return 0; | |
2284 | } | |
2285 | ||
547973de LP |
2286 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2287 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
0c7bff0a LP |
2288 | enum { |
2289 | PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2290 | PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2291 | PHASE_ALL, /* Phase #3, validate everything else */ | |
2292 | } phase; | |
547973de | 2293 | DnsResourceRecord *rr; |
105e1512 | 2294 | DnsAnswerFlags flags; |
56352fe9 | 2295 | int r; |
547973de LP |
2296 | |
2297 | assert(t); | |
2298 | ||
2299 | /* We have now collected all DS and DNSKEY RRs in | |
2300 | * t->validated_keys, let's see which RRs we can now | |
2301 | * authenticate with that. */ | |
2302 | ||
b652d4a2 | 2303 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de LP |
2304 | return 0; |
2305 | ||
2306 | /* Already validated */ | |
019036a4 | 2307 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) |
547973de LP |
2308 | return 0; |
2309 | ||
105e1512 | 2310 | /* Our own stuff needs no validation */ |
547973de | 2311 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { |
019036a4 | 2312 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
547973de LP |
2313 | t->answer_authenticated = true; |
2314 | return 0; | |
2315 | } | |
2316 | ||
105e1512 LP |
2317 | /* Cached stuff is not affected by validation. */ |
2318 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2319 | return 0; | |
2320 | ||
b652d4a2 LP |
2321 | if (t->current_features < DNS_SERVER_FEATURE_LEVEL_DO || |
2322 | (t->server && t->server->rrsig_missing)) { | |
2323 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
2324 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2325 | return 0; | |
2326 | } | |
2327 | ||
a5784c49 | 2328 | log_debug("Validating response from transaction %" PRIu16 " (%s).", t->id, dns_transaction_key_string(t)); |
547973de | 2329 | |
c9c72065 LP |
2330 | /* First, see if this response contains any revoked trust |
2331 | * anchors we care about */ | |
0f87f3e8 LP |
2332 | r = dns_transaction_check_revoked_trust_anchors(t); |
2333 | if (r < 0) | |
2334 | return r; | |
2335 | ||
c9c72065 LP |
2336 | /* Second, see if there are DNSKEYs we already know a |
2337 | * validated DS for. */ | |
56352fe9 LP |
2338 | r = dns_transaction_validate_dnskey_by_ds(t); |
2339 | if (r < 0) | |
2340 | return r; | |
547973de | 2341 | |
c9c72065 LP |
2342 | /* Third, remove all DNSKEY and DS RRs again that our trust |
2343 | * anchor says are revoked. After all we might have marked | |
2344 | * some keys revoked above, but they might still be lingering | |
2345 | * in our validated_keys list. */ | |
2346 | r = dns_transaction_invalidate_revoked_keys(t); | |
2347 | if (r < 0) | |
2348 | return r; | |
2349 | ||
0c7bff0a | 2350 | phase = PHASE_DNSKEY; |
547973de | 2351 | for (;;) { |
0c7bff0a | 2352 | bool changed = false, have_nsec = false; |
547973de LP |
2353 | |
2354 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
0c7bff0a | 2355 | DnsResourceRecord *rrsig = NULL; |
547973de LP |
2356 | DnssecResult result; |
2357 | ||
0c7bff0a LP |
2358 | switch (rr->key->type) { |
2359 | ||
2360 | case DNS_TYPE_RRSIG: | |
547973de LP |
2361 | continue; |
2362 | ||
0c7bff0a LP |
2363 | case DNS_TYPE_DNSKEY: |
2364 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2365 | if (phase == PHASE_NSEC) | |
2366 | continue; | |
2367 | break; | |
2368 | ||
2369 | case DNS_TYPE_NSEC: | |
2370 | case DNS_TYPE_NSEC3: | |
2371 | have_nsec = true; | |
2372 | ||
2373 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ | |
2374 | if (phase == PHASE_DNSKEY) | |
2375 | continue; | |
2376 | ||
2377 | break; | |
2378 | ||
2379 | default: | |
2380 | /* We validate all other RRs only in the ALL phases */ | |
2381 | if (phase != PHASE_ALL) | |
2382 | continue; | |
2383 | ||
2384 | break; | |
2385 | } | |
2386 | ||
2387 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); | |
547973de LP |
2388 | if (r < 0) |
2389 | return r; | |
2390 | ||
7b50eb2e | 2391 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
547973de | 2392 | |
56352fe9 | 2393 | if (result == DNSSEC_VALIDATED) { |
547973de | 2394 | |
547973de LP |
2395 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2396 | /* If we just validated a | |
2397 | * DNSKEY RRset, then let's | |
2398 | * add these keys to the set | |
2399 | * of validated keys for this | |
2400 | * transaction. */ | |
2401 | ||
105e1512 | 2402 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
547973de LP |
2403 | if (r < 0) |
2404 | return r; | |
c9c72065 LP |
2405 | |
2406 | /* some of the DNSKEYs we just | |
2407 | * added might already have | |
2408 | * been revoked, remove them | |
2409 | * again in that case. */ | |
2410 | r = dns_transaction_invalidate_revoked_keys(t); | |
2411 | if (r < 0) | |
2412 | return r; | |
547973de LP |
2413 | } |
2414 | ||
105e1512 LP |
2415 | /* Add the validated RRset to the new |
2416 | * list of validated RRsets, and | |
2417 | * remove it from the unvalidated | |
2418 | * RRsets. We mark the RRset as | |
2419 | * authenticated and cacheable. */ | |
2420 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
547973de LP |
2421 | if (r < 0) |
2422 | return r; | |
2423 | ||
a150ff5e LP |
2424 | t->scope->manager->n_dnssec_secure++; |
2425 | ||
56352fe9 | 2426 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
547973de LP |
2427 | changed = true; |
2428 | break; | |
f3cf586d | 2429 | } |
547973de | 2430 | |
0c7bff0a LP |
2431 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2432 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, we | |
2433 | * cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2434 | if (phase != PHASE_ALL) | |
f3cf586d | 2435 | continue; |
b652d4a2 | 2436 | |
0c7bff0a LP |
2437 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2438 | bool authenticated = false; | |
2439 | const char *suffix; | |
2440 | ||
2441 | /* This RRset validated, but as a wildcard. This means we need to proof via NSEC/NSEC3 | |
2442 | * that no matching non-wildcard RR exists. | |
2443 | * | |
2444 | * See RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4*/ | |
2445 | ||
2446 | r = dns_name_suffix(DNS_RESOURCE_KEY_NAME(rr->key), rrsig->rrsig.labels, &suffix); | |
2447 | if (r < 0) | |
2448 | return r; | |
2449 | if (r == 0) | |
2450 | return -EBADMSG; | |
2451 | ||
2452 | r = dns_name_parent(&suffix); | |
2453 | if (r < 0) | |
2454 | return r; | |
2455 | if (r == 0) | |
2456 | return -EBADMSG; | |
2457 | ||
2458 | r = dnssec_nsec_test_between(validated, DNS_RESOURCE_KEY_NAME(rr->key), suffix, &authenticated); | |
2459 | if (r < 0) | |
2460 | return r; | |
2461 | ||
2462 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ | |
2463 | if (r == 0 || !authenticated) | |
2464 | result = DNSSEC_INVALID; | |
2465 | ||
2466 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2467 | if (r < 0) | |
2468 | return r; | |
2469 | ||
2470 | t->scope->manager->n_dnssec_secure++; | |
2471 | ||
2472 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2473 | changed = true; | |
2474 | break; | |
2475 | } | |
2476 | ||
f3cf586d LP |
2477 | if (result == DNSSEC_NO_SIGNATURE) { |
2478 | r = dns_transaction_requires_rrsig(t, rr); | |
2479 | if (r < 0) | |
2480 | return r; | |
2481 | if (r == 0) { | |
2482 | /* Data does not require signing. In that case, just copy it over, | |
2483 | * but remember that this is by no means authenticated.*/ | |
2484 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
b652d4a2 LP |
2485 | if (r < 0) |
2486 | return r; | |
b652d4a2 | 2487 | |
f3cf586d LP |
2488 | t->scope->manager->n_dnssec_insecure++; |
2489 | changed = true; | |
2490 | break; | |
2491 | } | |
b652d4a2 | 2492 | |
f3cf586d LP |
2493 | r = dns_transaction_known_signed(t, rr); |
2494 | if (r < 0) | |
2495 | return r; | |
2496 | if (r > 0) { | |
2497 | /* This is an RR we know has to be signed. If it isn't this means | |
2498 | * the server is not attaching RRSIGs, hence complain. */ | |
d33b6cf3 | 2499 | |
f3cf586d | 2500 | dns_server_packet_rrsig_missing(t->server); |
d33b6cf3 | 2501 | |
f3cf586d | 2502 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
d33b6cf3 | 2503 | |
f3cf586d | 2504 | /* Downgrading is OK? If so, just consider the information unsigned */ |
d33b6cf3 LP |
2505 | |
2506 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2507 | if (r < 0) | |
2508 | return r; | |
2509 | ||
2510 | t->scope->manager->n_dnssec_insecure++; | |
2511 | changed = true; | |
2512 | break; | |
2513 | } | |
f3cf586d LP |
2514 | |
2515 | /* Otherwise, fail */ | |
2516 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2517 | return 0; | |
94aa7071 LP |
2518 | } |
2519 | ||
f3cf586d LP |
2520 | r = dns_transaction_in_private_tld(t, rr->key); |
2521 | if (r < 0) | |
2522 | return r; | |
2523 | if (r > 0) { | |
2524 | _cleanup_free_ char *s = NULL; | |
94aa7071 | 2525 | |
f3cf586d LP |
2526 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2527 | * mode, hence ignore the fact that this was not signed. */ | |
94aa7071 | 2528 | |
f3cf586d LP |
2529 | (void) dns_resource_key_to_string(rr->key, &s); |
2530 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", strna(s ? strstrip(s) : NULL)); | |
94aa7071 | 2531 | |
f3cf586d LP |
2532 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); |
2533 | if (r < 0) | |
2534 | return r; | |
a150ff5e | 2535 | |
f3cf586d LP |
2536 | t->scope->manager->n_dnssec_insecure++; |
2537 | changed = true; | |
2538 | break; | |
105e1512 | 2539 | } |
f3cf586d | 2540 | } |
105e1512 | 2541 | |
f3cf586d LP |
2542 | if (IN_SET(result, |
2543 | DNSSEC_MISSING_KEY, | |
2544 | DNSSEC_SIGNATURE_EXPIRED, | |
2545 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
a150ff5e | 2546 | |
f3cf586d LP |
2547 | r = dns_transaction_dnskey_authenticated(t, rr); |
2548 | if (r < 0 && r != -ENXIO) | |
547973de | 2549 | return r; |
f3cf586d LP |
2550 | if (r == 0) { |
2551 | /* The DNSKEY transaction was not authenticated, this means there's | |
2552 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
2553 | ||
2554 | r = dns_answer_move_by_key(&validated, &t->answer, rr->key, 0); | |
2555 | if (r < 0) | |
2556 | return r; | |
2557 | ||
2558 | t->scope->manager->n_dnssec_insecure++; | |
2559 | changed = true; | |
2560 | break; | |
547973de | 2561 | } |
f3cf586d | 2562 | } |
547973de | 2563 | |
f3cf586d LP |
2564 | if (IN_SET(result, |
2565 | DNSSEC_INVALID, | |
2566 | DNSSEC_SIGNATURE_EXPIRED, | |
2567 | DNSSEC_NO_SIGNATURE)) | |
2568 | t->scope->manager->n_dnssec_bogus++; | |
2569 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2570 | t->scope->manager->n_dnssec_indeterminate++; | |
547973de | 2571 | |
f3cf586d LP |
2572 | r = dns_transaction_is_primary_response(t, rr); |
2573 | if (r < 0) | |
2574 | return r; | |
2575 | if (r > 0) { | |
2576 | /* This is a primary response | |
2577 | * to our question, and it | |
2578 | * failed validation. That's | |
2579 | * fatal. */ | |
2580 | t->answer_dnssec_result = result; | |
2581 | return 0; | |
547973de | 2582 | } |
f3cf586d LP |
2583 | |
2584 | /* This is just some auxiliary | |
2585 | * data. Just remove the RRset and | |
2586 | * continue. */ | |
2587 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2588 | if (r < 0) | |
2589 | return r; | |
2590 | ||
2591 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2592 | changed = true; | |
2593 | break; | |
547973de LP |
2594 | } |
2595 | ||
0c7bff0a | 2596 | /* Restart the inner loop as long as we managed to achieve something */ |
547973de LP |
2597 | if (changed) |
2598 | continue; | |
2599 | ||
0c7bff0a LP |
2600 | if (phase == PHASE_DNSKEY && have_nsec) { |
2601 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ | |
2602 | phase = PHASE_NSEC; | |
2603 | continue; | |
2604 | } | |
2605 | ||
2606 | if (phase != PHASE_ALL) { | |
2607 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. Note that in this | |
2608 | * third phase we start to remove RRs we couldn't validate. */ | |
2609 | phase = PHASE_ALL; | |
56352fe9 | 2610 | continue; |
547973de LP |
2611 | } |
2612 | ||
56352fe9 | 2613 | /* We're done */ |
547973de LP |
2614 | break; |
2615 | } | |
2616 | ||
2617 | dns_answer_unref(t->answer); | |
2618 | t->answer = validated; | |
2619 | validated = NULL; | |
2620 | ||
72667f08 LP |
2621 | /* At this point the answer only contains validated |
2622 | * RRsets. Now, let's see if it actually answers the question | |
2623 | * we asked. If so, great! If it doesn't, then see if | |
2624 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 2625 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 2626 | if (r > 0) { |
105e1512 LP |
2627 | /* Yes, it answers the question! */ |
2628 | ||
2629 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
2630 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 2631 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
2632 | t->answer_rcode = DNS_RCODE_SUCCESS; |
2633 | t->answer_authenticated = true; | |
2634 | } else { | |
2635 | /* The answer is not fully authenticated. */ | |
019036a4 | 2636 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2637 | t->answer_authenticated = false; |
2638 | } | |
2639 | ||
72667f08 LP |
2640 | } else if (r == 0) { |
2641 | DnssecNsecResult nr; | |
ed29bfdc | 2642 | bool authenticated = false; |
72667f08 LP |
2643 | |
2644 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 2645 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
2646 | if (r < 0) |
2647 | return r; | |
2648 | ||
2649 | switch (nr) { | |
2650 | ||
2651 | case DNSSEC_NSEC_NXDOMAIN: | |
2652 | /* NSEC proves the domain doesn't exist. Very good. */ | |
105e1512 | 2653 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2654 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2655 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 2656 | t->answer_authenticated = authenticated; |
72667f08 LP |
2657 | break; |
2658 | ||
2659 | case DNSSEC_NSEC_NODATA: | |
2660 | /* NSEC proves that there's no data here, very good. */ | |
105e1512 | 2661 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); |
019036a4 | 2662 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 2663 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 2664 | t->answer_authenticated = authenticated; |
72667f08 LP |
2665 | break; |
2666 | ||
105e1512 LP |
2667 | case DNSSEC_NSEC_OPTOUT: |
2668 | /* NSEC3 says the data might not be signed */ | |
2669 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, dns_transaction_key_string(t)); | |
019036a4 | 2670 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2671 | t->answer_authenticated = false; |
2672 | break; | |
2673 | ||
72667f08 LP |
2674 | case DNSSEC_NSEC_NO_RR: |
2675 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
2676 | |
2677 | r = dns_transaction_requires_nsec(t); | |
2678 | if (r < 0) | |
2679 | return r; | |
2680 | if (r > 0) | |
019036a4 | 2681 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
105e1512 | 2682 | else { |
019036a4 | 2683 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
2684 | t->answer_authenticated = false; |
2685 | } | |
2686 | ||
2687 | break; | |
2688 | ||
2689 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
2690 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 2691 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
72667f08 LP |
2692 | break; |
2693 | ||
2694 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 2695 | case DNSSEC_NSEC_CNAME: |
72667f08 | 2696 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 2697 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
72667f08 LP |
2698 | break; |
2699 | ||
2700 | default: | |
2701 | assert_not_reached("Unexpected NSEC result."); | |
2702 | } | |
2703 | } | |
2704 | ||
547973de LP |
2705 | return 1; |
2706 | } | |
2707 | ||
a5784c49 LP |
2708 | const char *dns_transaction_key_string(DnsTransaction *t) { |
2709 | assert(t); | |
2710 | ||
2711 | if (!t->key_string) { | |
2712 | if (dns_resource_key_to_string(t->key, &t->key_string) < 0) | |
2713 | return "n/a"; | |
2714 | } | |
2715 | ||
2716 | return strstrip(t->key_string); | |
2717 | } | |
2718 | ||
ec2c5e43 LP |
2719 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
2720 | [DNS_TRANSACTION_NULL] = "null", | |
2721 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 2722 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 2723 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
2724 | [DNS_TRANSACTION_SUCCESS] = "success", |
2725 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
2726 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
2727 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
2728 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
2729 | [DNS_TRANSACTION_RESOURCES] = "resources", | |
ac720200 | 2730 | [DNS_TRANSACTION_CONNECTION_FAILURE] = "connection-failure", |
ec2c5e43 | 2731 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 2732 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 2733 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
ec2c5e43 LP |
2734 | }; |
2735 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
2736 | |
2737 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
2738 | [DNS_TRANSACTION_NETWORK] = "network", | |
2739 | [DNS_TRANSACTION_CACHE] = "cache", | |
2740 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 2741 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
2742 | }; |
2743 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |