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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
ec2c5e43 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2014 Lennart Poettering | |
ec2c5e43 LP |
6 | ***/ |
7 | ||
62cc1c55 | 8 | #include "sd-messages.h" |
beef6a5f | 9 | |
ec2c5e43 | 10 | #include "af-list.h" |
b5efdb8a | 11 | #include "alloc-util.h" |
f52e61da | 12 | #include "dns-domain.h" |
7cc6ed7b | 13 | #include "errno-list.h" |
3ffd4af2 LP |
14 | #include "fd-util.h" |
15 | #include "random-util.h" | |
7778dfff | 16 | #include "resolved-dns-cache.h" |
3ffd4af2 LP |
17 | #include "resolved-dns-transaction.h" |
18 | #include "resolved-llmnr.h" | |
8b43440b | 19 | #include "string-table.h" |
ec2c5e43 | 20 | |
b214dc0f | 21 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 22 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 23 | |
c61d2b44 LP |
24 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
25 | assert(t); | |
26 | ||
27 | t->received = dns_packet_unref(t->received); | |
28 | t->answer = dns_answer_unref(t->answer); | |
29 | t->answer_rcode = 0; | |
30 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
31 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
32 | t->answer_authenticated = false; | |
d3760be0 | 33 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 34 | t->answer_errno = 0; |
c61d2b44 LP |
35 | } |
36 | ||
c5b4f861 LP |
37 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
38 | DnsTransaction *z; | |
39 | ||
40 | assert(t); | |
41 | ||
42 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
43 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 44 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
45 | dns_transaction_gc(z); |
46 | } | |
47 | } | |
48 | ||
f32f0e57 LP |
49 | static void dns_transaction_close_connection(DnsTransaction *t) { |
50 | assert(t); | |
51 | ||
b30bf55d LP |
52 | if (t->stream) { |
53 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
54 | t->stream->complete = NULL; | |
55 | t->stream->on_packet = NULL; | |
56 | t->stream->transaction = NULL; | |
57 | t->stream = dns_stream_unref(t->stream); | |
58 | } | |
59 | ||
f32f0e57 LP |
60 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
61 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
62 | } | |
63 | ||
f535705a | 64 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
65 | assert(t); |
66 | ||
67 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
68 | } |
69 | ||
ec2c5e43 | 70 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 71 | DnsQueryCandidate *c; |
ec2c5e43 | 72 | DnsZoneItem *i; |
547973de | 73 | DnsTransaction *z; |
ec2c5e43 LP |
74 | |
75 | if (!t) | |
76 | return NULL; | |
77 | ||
51e399bc LP |
78 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
79 | ||
f32f0e57 | 80 | dns_transaction_close_connection(t); |
f535705a | 81 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 82 | |
ec2c5e43 | 83 | dns_packet_unref(t->sent); |
c61d2b44 | 84 | dns_transaction_reset_answer(t); |
ec2c5e43 | 85 | |
8300ba21 | 86 | dns_server_unref(t->server); |
ec2c5e43 LP |
87 | |
88 | if (t->scope) { | |
f9ebb22a LP |
89 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
90 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
91 | |
92 | if (t->id != 0) | |
93 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
94 | } | |
95 | ||
547973de | 96 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 97 | set_remove(c->transactions, t); |
547973de | 98 | set_free(t->notify_query_candidates); |
801ad6a6 | 99 | |
35aa04e9 LP |
100 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
101 | set_remove(c->transactions, t); | |
102 | set_free(t->notify_query_candidates_done); | |
103 | ||
547973de | 104 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 105 | i->probe_transaction = NULL; |
547973de LP |
106 | set_free(t->notify_zone_items); |
107 | ||
35aa04e9 LP |
108 | while ((i = set_steal_first(t->notify_zone_items_done))) |
109 | i->probe_transaction = NULL; | |
110 | set_free(t->notify_zone_items_done); | |
111 | ||
547973de LP |
112 | while ((z = set_steal_first(t->notify_transactions))) |
113 | set_remove(z->dnssec_transactions, t); | |
114 | set_free(t->notify_transactions); | |
115 | ||
35aa04e9 LP |
116 | while ((z = set_steal_first(t->notify_transactions_done))) |
117 | set_remove(z->dnssec_transactions, t); | |
118 | set_free(t->notify_transactions_done); | |
119 | ||
c5b4f861 | 120 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
121 | set_free(t->dnssec_transactions); |
122 | ||
123 | dns_answer_unref(t->validated_keys); | |
97cc656c | 124 | dns_resource_key_unref(t->key); |
97cc656c | 125 | |
6b430fdb | 126 | return mfree(t); |
ec2c5e43 LP |
127 | } |
128 | ||
129 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
130 | ||
51e399bc | 131 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
132 | assert(t); |
133 | ||
134 | if (t->block_gc > 0) | |
51e399bc | 135 | return true; |
ec2c5e43 | 136 | |
547973de | 137 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 138 | set_isempty(t->notify_query_candidates_done) && |
547973de | 139 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
140 | set_isempty(t->notify_zone_items_done) && |
141 | set_isempty(t->notify_transactions) && | |
142 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 143 | dns_transaction_free(t); |
51e399bc LP |
144 | return false; |
145 | } | |
146 | ||
147 | return true; | |
ec2c5e43 LP |
148 | } |
149 | ||
4dd15077 LP |
150 | static uint16_t pick_new_id(Manager *m) { |
151 | uint16_t new_id; | |
152 | ||
153 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
154 | * transactions, and it's much lower than the space of IDs. */ | |
155 | ||
156 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
157 | ||
158 | do | |
159 | random_bytes(&new_id, sizeof(new_id)); | |
160 | while (new_id == 0 || | |
161 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
162 | ||
163 | return new_id; | |
164 | } | |
165 | ||
f52e61da | 166 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
167 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
168 | int r; | |
169 | ||
170 | assert(ret); | |
171 | assert(s); | |
f52e61da | 172 | assert(key); |
ec2c5e43 | 173 | |
9eae2bf3 | 174 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 175 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 176 | return -EINVAL; |
d0129ddb LP |
177 | if (dns_type_is_obsolete(key->type)) |
178 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
179 | |
180 | /* We only support the IN class */ | |
4c701096 | 181 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
182 | return -EOPNOTSUPP; |
183 | ||
b214dc0f LP |
184 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
185 | return -EBUSY; | |
186 | ||
d5099efc | 187 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
188 | if (r < 0) |
189 | return r; | |
190 | ||
f9ebb22a | 191 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
192 | if (r < 0) |
193 | return r; | |
194 | ||
ec2c5e43 LP |
195 | t = new0(DnsTransaction, 1); |
196 | if (!t) | |
197 | return -ENOMEM; | |
198 | ||
4667e00a | 199 | t->dns_udp_fd = -1; |
c3bc53e6 | 200 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 201 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 202 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 203 | t->key = dns_resource_key_ref(key); |
274b8748 | 204 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
d001e0a3 | 205 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 206 | |
4dd15077 | 207 | t->id = pick_new_id(s->manager); |
ec2c5e43 LP |
208 | |
209 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
210 | if (r < 0) { | |
211 | t->id = 0; | |
212 | return r; | |
213 | } | |
214 | ||
f9ebb22a | 215 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
216 | if (r < 0) { |
217 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
218 | return r; | |
219 | } | |
220 | ||
f9ebb22a | 221 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
222 | t->scope = s; |
223 | ||
313cefa1 | 224 | s->manager->n_transactions_total++; |
a150ff5e | 225 | |
ec2c5e43 LP |
226 | if (ret) |
227 | *ret = t; | |
228 | ||
229 | t = NULL; | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
4dd15077 LP |
234 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
235 | uint16_t new_id; | |
236 | assert(t); | |
237 | ||
238 | /* Pick a new ID for this transaction. */ | |
239 | ||
240 | new_id = pick_new_id(t->scope->manager); | |
241 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
242 | ||
243 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
244 | t->id = new_id; | |
245 | ||
246 | /* Make sure we generate a new packet with the new ID */ | |
247 | t->sent = dns_packet_unref(t->sent); | |
248 | } | |
249 | ||
ec2c5e43 | 250 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 251 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 252 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 253 | DnsZoneItem *z; |
ec2c5e43 LP |
254 | |
255 | assert(t); | |
256 | assert(p); | |
257 | ||
258 | if (manager_our_packet(t->scope->manager, p) != 0) | |
259 | return; | |
260 | ||
164d025d | 261 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 262 | |
a5784c49 LP |
263 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
264 | t->id, | |
202b76ae | 265 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
266 | dns_protocol_to_string(t->scope->protocol), |
267 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 268 | af_to_name_short(t->scope->family), |
164d025d | 269 | strnull(pretty)); |
ec2c5e43 | 270 | |
a4076574 LP |
271 | /* RFC 4795, Section 4.1 says that the peer with the |
272 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
273 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
274 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
275 | return; |
276 | } | |
277 | ||
4d91eec4 | 278 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 279 | |
ec2c5e43 | 280 | t->block_gc++; |
35aa04e9 | 281 | |
547973de | 282 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
283 | /* First, make sure the zone item drops the reference |
284 | * to us */ | |
285 | dns_zone_item_probe_stop(z); | |
286 | ||
287 | /* Secondly, report this as conflict, so that we might | |
288 | * look for a different hostname */ | |
ec2c5e43 | 289 | dns_zone_item_conflict(z); |
3ef64445 | 290 | } |
ec2c5e43 LP |
291 | t->block_gc--; |
292 | ||
293 | dns_transaction_gc(t); | |
294 | } | |
295 | ||
296 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 297 | DnsQueryCandidate *c; |
ec2c5e43 | 298 | DnsZoneItem *z; |
547973de | 299 | DnsTransaction *d; |
7cc6ed7b | 300 | const char *st; |
202b76ae | 301 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
302 | |
303 | assert(t); | |
547973de | 304 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 305 | |
202b76ae ZJS |
306 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
307 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
308 | ||
f61dfddb | 309 | log_struct(LOG_NOTICE, |
2b044526 | 310 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
202b76ae | 311 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 312 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 313 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 314 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
1e02e182 LP |
315 | "DNS_SERVER=%s", dns_server_string(t->server), |
316 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level), | |
f61dfddb | 317 | NULL); |
202b76ae | 318 | } |
f61dfddb | 319 | |
ec2c5e43 LP |
320 | /* Note that this call might invalidate the query. Callers |
321 | * should hence not attempt to access the query or transaction | |
322 | * after calling this function. */ | |
323 | ||
7cc6ed7b LP |
324 | if (state == DNS_TRANSACTION_ERRNO) |
325 | st = errno_to_name(t->answer_errno); | |
326 | else | |
327 | st = dns_transaction_state_to_string(state); | |
328 | ||
a5784c49 LP |
329 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
330 | t->id, | |
202b76ae | 331 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
332 | dns_protocol_to_string(t->scope->protocol), |
333 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 334 | af_to_name_short(t->scope->family), |
7cc6ed7b | 335 | st, |
a5784c49 LP |
336 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
337 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
338 | |
339 | t->state = state; | |
340 | ||
f32f0e57 | 341 | dns_transaction_close_connection(t); |
f535705a | 342 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
343 | |
344 | /* Notify all queries that are interested, but make sure the | |
345 | * transaction isn't freed while we are still looking at it */ | |
346 | t->block_gc++; | |
f7014757 | 347 | |
35aa04e9 | 348 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 349 | dns_query_candidate_notify(c); |
35aa04e9 | 350 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 351 | |
35aa04e9 LP |
352 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
353 | dns_zone_item_notify(z); | |
354 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
8d67e72c | 355 | if (t->probing && t->state == DNS_TRANSACTION_ATTEMPTS_MAX_REACHED) |
1a63fc54 | 356 | (void) dns_scope_announce(t->scope, false); |
f7014757 | 357 | |
35aa04e9 LP |
358 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
359 | dns_transaction_notify(d, t); | |
360 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
361 | |
362 | t->block_gc--; | |
ec2c5e43 LP |
363 | dns_transaction_gc(t); |
364 | } | |
365 | ||
519ef046 LP |
366 | static int dns_transaction_pick_server(DnsTransaction *t) { |
367 | DnsServer *server; | |
368 | ||
369 | assert(t); | |
370 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
371 | ||
d001e0a3 LP |
372 | /* Pick a DNS server and a feature level for it. */ |
373 | ||
519ef046 LP |
374 | server = dns_scope_get_dns_server(t->scope); |
375 | if (!server) | |
376 | return -ESRCH; | |
377 | ||
d001e0a3 LP |
378 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
379 | * different properties. */ | |
380 | if (server != t->server) | |
381 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
382 | ||
274b8748 | 383 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 384 | |
d001e0a3 LP |
385 | /* Clamp the feature level if that is requested. */ |
386 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
387 | t->current_feature_level > t->clamp_feature_level) | |
388 | t->current_feature_level = t->clamp_feature_level; | |
389 | ||
390 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
391 | ||
519ef046 LP |
392 | if (server == t->server) |
393 | return 0; | |
394 | ||
395 | dns_server_unref(t->server); | |
396 | t->server = dns_server_ref(server); | |
397 | ||
44db02d0 LP |
398 | t->n_picked_servers ++; |
399 | ||
d001e0a3 LP |
400 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
401 | ||
519ef046 LP |
402 | return 1; |
403 | } | |
404 | ||
d001e0a3 | 405 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
406 | int r; |
407 | ||
408 | assert(t); | |
409 | ||
410 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
411 | ||
412 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
413 | if (next_server) |
414 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
415 | |
416 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
417 | if (r < 0) { |
418 | t->answer_errno = -r; | |
419 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
420 | } | |
8d10d620 LP |
421 | } |
422 | ||
c02cf2f4 | 423 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
424 | int r; |
425 | ||
c02cf2f4 LP |
426 | assert(t); |
427 | ||
5278bbfe LP |
428 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
429 | ||
c02cf2f4 LP |
430 | if (!t->server) |
431 | return 0; | |
432 | ||
433 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
434 | return 0; | |
435 | ||
436 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
437 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
438 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
439 | OPT RR or DO bit. One of these cases is documented here, for example: | |
440 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
441 | ||
4dd15077 LP |
442 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
443 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
444 | |
445 | r = dns_transaction_go(t); | |
446 | if (r < 0) | |
447 | return r; | |
448 | ||
449 | return 1; | |
c02cf2f4 LP |
450 | } |
451 | ||
ec2c5e43 LP |
452 | static int on_stream_complete(DnsStream *s, int error) { |
453 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
454 | DnsTransaction *t; | |
455 | ||
456 | assert(s); | |
457 | assert(s->transaction); | |
458 | ||
459 | /* Copy the data we care about out of the stream before we | |
460 | * destroy it. */ | |
461 | t = s->transaction; | |
462 | p = dns_packet_ref(s->read_packet); | |
463 | ||
b30bf55d | 464 | dns_transaction_close_connection(t); |
ec2c5e43 | 465 | |
a1a3f73a LP |
466 | if (ERRNO_IS_DISCONNECT(error)) { |
467 | usec_t usec; | |
468 | ||
0791110f LP |
469 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
470 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
471 | * question on this scope. */ | |
472 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
473 | return 0; | |
474 | } | |
475 | ||
92ec902a | 476 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); |
a1a3f73a | 477 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 478 | dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec); |
a1a3f73a | 479 | |
d001e0a3 | 480 | dns_transaction_retry(t, true); |
ac720200 LP |
481 | return 0; |
482 | } | |
ec2c5e43 | 483 | if (error != 0) { |
7cc6ed7b LP |
484 | t->answer_errno = error; |
485 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
486 | return 0; |
487 | } | |
488 | ||
a4076574 | 489 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 490 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
491 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
492 | return 0; | |
493 | } | |
494 | ||
495 | dns_scope_check_conflicts(t->scope, p); | |
496 | ||
ec2c5e43 LP |
497 | t->block_gc++; |
498 | dns_transaction_process_reply(t, p); | |
499 | t->block_gc--; | |
500 | ||
519ef046 LP |
501 | /* If the response wasn't useful, then complete the transition |
502 | * now. After all, we are the worst feature set now with TCP | |
503 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
504 | if (t->state == DNS_TRANSACTION_PENDING) |
505 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
506 | else |
507 | dns_transaction_gc(t); | |
ec2c5e43 LP |
508 | |
509 | return 0; | |
510 | } | |
511 | ||
512 | static int dns_transaction_open_tcp(DnsTransaction *t) { | |
513 | _cleanup_close_ int fd = -1; | |
514 | int r; | |
515 | ||
516 | assert(t); | |
517 | ||
519ef046 | 518 | dns_transaction_close_connection(t); |
ec2c5e43 | 519 | |
106784eb | 520 | switch (t->scope->protocol) { |
519ef046 | 521 | |
106784eb | 522 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
523 | r = dns_transaction_pick_server(t); |
524 | if (r < 0) | |
525 | return r; | |
526 | ||
92ec902a | 527 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
528 | return -EOPNOTSUPP; |
529 | ||
274b8748 | 530 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
531 | if (r < 0) |
532 | return r; | |
533 | ||
534 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53); | |
106784eb | 535 | break; |
ec2c5e43 | 536 | |
106784eb | 537 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 538 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 539 | if (t->received) |
519ef046 | 540 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port); |
ec2c5e43 LP |
541 | else { |
542 | union in_addr_union address; | |
a7f7d1bd | 543 | int family = AF_UNSPEC; |
ec2c5e43 LP |
544 | |
545 | /* Otherwise, try to talk to the owner of a | |
546 | * the IP address, in case this is a reverse | |
547 | * PTR lookup */ | |
f52e61da | 548 | |
1c02e7ba | 549 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
550 | if (r < 0) |
551 | return r; | |
552 | if (r == 0) | |
553 | return -EINVAL; | |
9e08a6e0 | 554 | if (family != t->scope->family) |
9318cdd3 | 555 | return -ESRCH; |
ec2c5e43 | 556 | |
519ef046 | 557 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT); |
ec2c5e43 | 558 | } |
106784eb DM |
559 | |
560 | break; | |
561 | ||
562 | default: | |
ec2c5e43 | 563 | return -EAFNOSUPPORT; |
106784eb | 564 | } |
ec2c5e43 LP |
565 | |
566 | if (fd < 0) | |
567 | return fd; | |
568 | ||
569 | r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd); | |
570 | if (r < 0) | |
571 | return r; | |
ec2c5e43 LP |
572 | fd = -1; |
573 | ||
574 | r = dns_stream_write_packet(t->stream, t->sent); | |
575 | if (r < 0) { | |
b30bf55d | 576 | t->stream = dns_stream_unref(t->stream); |
ec2c5e43 LP |
577 | return r; |
578 | } | |
579 | ||
ec2c5e43 LP |
580 | t->stream->complete = on_stream_complete; |
581 | t->stream->transaction = t; | |
582 | ||
583 | /* The interface index is difficult to determine if we are | |
584 | * connecting to the local host, hence fill this in right away | |
585 | * instead of determining it from the socket */ | |
97ebebbc | 586 | t->stream->ifindex = dns_scope_ifindex(t->scope); |
ec2c5e43 | 587 | |
519ef046 LP |
588 | dns_transaction_reset_answer(t); |
589 | ||
cbe4216d LP |
590 | t->tried_stream = true; |
591 | ||
ec2c5e43 LP |
592 | return 0; |
593 | } | |
594 | ||
547973de | 595 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
596 | assert(t); |
597 | ||
598 | /* For mDNS we cache whenever we get the packet, rather than | |
599 | * in each transaction. */ | |
600 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
601 | return; | |
602 | ||
ceeddf79 MP |
603 | /* Caching disabled? */ |
604 | if (!t->scope->manager->enable_cache) | |
605 | return; | |
606 | ||
547973de LP |
607 | /* We never cache if this packet is from the local host, under |
608 | * the assumption that a locally running DNS server would | |
609 | * cache this anyway, and probably knows better when to flush | |
610 | * the cache then we could. */ | |
611 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
612 | return; | |
613 | ||
547973de LP |
614 | dns_cache_put(&t->scope->cache, |
615 | t->key, | |
616 | t->answer_rcode, | |
617 | t->answer, | |
547973de | 618 | t->answer_authenticated, |
d3760be0 | 619 | t->answer_nsec_ttl, |
547973de LP |
620 | 0, |
621 | t->received->family, | |
622 | &t->received->sender); | |
623 | } | |
624 | ||
105e1512 LP |
625 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
626 | DnsTransaction *dt; | |
627 | Iterator i; | |
628 | ||
629 | assert(t); | |
630 | ||
631 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
632 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
633 | return true; | |
634 | ||
635 | return false; | |
636 | } | |
637 | ||
942eb2e7 LP |
638 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
639 | DnsTransaction *dt; | |
640 | Iterator i; | |
641 | ||
642 | assert(t); | |
643 | ||
644 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
645 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
646 | ||
647 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
648 | ||
649 | switch (dt->state) { | |
650 | ||
651 | case DNS_TRANSACTION_NULL: | |
652 | case DNS_TRANSACTION_PENDING: | |
653 | case DNS_TRANSACTION_VALIDATING: | |
654 | /* Still ongoing */ | |
655 | return 0; | |
656 | ||
657 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 658 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
659 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
660 | goto fail; | |
661 | } | |
662 | ||
b3c6b00a LP |
663 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
664 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
665 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
666 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
667 | |
668 | case DNS_TRANSACTION_SUCCESS: | |
669 | /* All good. */ | |
670 | break; | |
671 | ||
672 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
673 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
674 | * validationr result */ | |
675 | ||
676 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
677 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
678 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
679 | return 0; | |
680 | ||
681 | ||
682 | default: | |
683 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
684 | goto fail; | |
685 | } | |
686 | } | |
687 | ||
688 | /* All is ready, we can go and validate */ | |
689 | return 1; | |
690 | ||
691 | fail: | |
692 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
693 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
694 | return 0; | |
695 | } | |
696 | ||
547973de LP |
697 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
698 | int r; | |
699 | ||
700 | assert(t); | |
701 | ||
702 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 703 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
704 | if (r < 0) |
705 | goto fail; | |
942eb2e7 | 706 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
707 | return; |
708 | ||
c02cf2f4 LP |
709 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
710 | * restart the lookup immediately. */ | |
711 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
712 | if (r < 0) |
713 | goto fail; | |
c02cf2f4 LP |
714 | if (r > 0) /* Transaction got restarted... */ |
715 | return; | |
716 | ||
547973de LP |
717 | /* All our auxiliary DNSSEC transactions are complete now. Try |
718 | * to validate our RRset now. */ | |
719 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
720 | if (r == -EBADMSG) { |
721 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
722 | return; | |
723 | } | |
7cc6ed7b LP |
724 | if (r < 0) |
725 | goto fail; | |
547973de | 726 | |
b652d4a2 LP |
727 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
728 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
729 | |
730 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
731 | * that works. */ | |
732 | ||
733 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { | |
734 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
735 | dns_transaction_retry(t, true); | |
736 | return; | |
737 | } | |
738 | ||
739 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
740 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
741 | return; | |
742 | } | |
743 | ||
019036a4 | 744 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
745 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
746 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
747 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
748 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
749 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
750 | return; | |
751 | } | |
752 | ||
1e02e182 LP |
753 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
754 | dns_server_warn_downgrade(t->server); | |
755 | ||
547973de LP |
756 | dns_transaction_cache_answer(t); |
757 | ||
758 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
759 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
760 | else | |
3bbdc31d | 761 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
762 | |
763 | return; | |
764 | ||
765 | fail: | |
766 | t->answer_errno = -r; | |
767 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
768 | } |
769 | ||
eac7cda2 LP |
770 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
771 | int r; | |
772 | ||
773 | assert(t); | |
774 | ||
775 | /* Checks whether the answer is positive, i.e. either a direct | |
776 | * answer to the question, or a CNAME/DNAME for it */ | |
777 | ||
778 | r = dns_answer_match_key(t->answer, t->key, flags); | |
779 | if (r != 0) | |
780 | return r; | |
781 | ||
782 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
783 | if (r != 0) | |
784 | return r; | |
785 | ||
786 | return false; | |
787 | } | |
788 | ||
789 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
790 | int r; | |
791 | ||
792 | assert(t); | |
793 | ||
794 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
795 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
796 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
797 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
798 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
799 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
800 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
801 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
802 | * incomplete CNAME/DNAME chain. | |
803 | * | |
804 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
805 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
806 | * lookup. */ | |
807 | ||
808 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
809 | return 0; | |
810 | ||
811 | r = dns_transaction_has_positive_answer(t, NULL); | |
812 | if (r <= 0) | |
813 | return r; | |
814 | ||
815 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
816 | return 0; | |
817 | } | |
818 | ||
ec2c5e43 | 819 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 820 | usec_t ts; |
ec2c5e43 LP |
821 | int r; |
822 | ||
823 | assert(t); | |
824 | assert(p); | |
9df3ba6c TG |
825 | assert(t->scope); |
826 | assert(t->scope->manager); | |
ec2c5e43 | 827 | |
5a7e41a3 LP |
828 | if (t->state != DNS_TRANSACTION_PENDING) |
829 | return; | |
830 | ||
ec2c5e43 LP |
831 | /* Note that this call might invalidate the query. Callers |
832 | * should hence not attempt to access the query or transaction | |
833 | * after calling this function. */ | |
834 | ||
1fdeaeb7 | 835 | log_debug("Processing incoming packet on transaction %" PRIu16". (rcode=%s)", t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
b5efcf29 | 836 | |
106784eb | 837 | switch (t->scope->protocol) { |
b5efcf29 | 838 | |
106784eb | 839 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 840 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 841 | |
97ebebbc | 842 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
843 | return; |
844 | ||
845 | if (p->family != t->scope->family) | |
846 | return; | |
847 | ||
848 | /* Tentative packets are not full responses but still | |
849 | * useful for identifying uniqueness conflicts during | |
850 | * probing. */ | |
8b757a38 | 851 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
852 | dns_transaction_tentative(t, p); |
853 | return; | |
854 | } | |
106784eb DM |
855 | |
856 | break; | |
857 | ||
4e5bf5e1 | 858 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 859 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
860 | |
861 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
862 | return; |
863 | ||
864 | if (p->family != t->scope->family) | |
865 | return; | |
866 | ||
867 | break; | |
868 | ||
106784eb | 869 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
870 | /* Note that we do not need to verify the |
871 | * addresses/port numbers of incoming traffic, as we | |
872 | * invoked connect() on our UDP socket in which case | |
873 | * the kernel already does the needed verification for | |
874 | * us. */ | |
106784eb DM |
875 | break; |
876 | ||
877 | default: | |
9c56a6f3 | 878 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
879 | } |
880 | ||
ec2c5e43 LP |
881 | if (t->received != p) { |
882 | dns_packet_unref(t->received); | |
883 | t->received = dns_packet_ref(p); | |
884 | } | |
885 | ||
c3bc53e6 LP |
886 | t->answer_source = DNS_TRANSACTION_NETWORK; |
887 | ||
ec2c5e43 LP |
888 | if (p->ipproto == IPPROTO_TCP) { |
889 | if (DNS_PACKET_TC(p)) { | |
890 | /* Truncated via TCP? Somebody must be fucking with us */ | |
891 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
892 | return; | |
893 | } | |
894 | ||
895 | if (DNS_PACKET_ID(p) != t->id) { | |
896 | /* Not the reply to our query? Somebody must be fucking with us */ | |
897 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
898 | return; | |
899 | } | |
900 | } | |
901 | ||
38a03f06 | 902 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
903 | |
904 | switch (t->scope->protocol) { | |
8af5b883 | 905 | |
9df3ba6c TG |
906 | case DNS_PROTOCOL_DNS: |
907 | assert(t->server); | |
908 | ||
4e0b8b17 TG |
909 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
910 | ||
8af5b883 | 911 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 912 | |
7d581a65 | 913 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
44db02d0 | 914 | |
7d581a65 | 915 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade |
44db02d0 LP |
916 | * this transaction anymore, but let's see if it might make sense to send the request |
917 | * to a different DNS server instead. If not let's process the response, and accept the | |
7d581a65 LP |
918 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate |
919 | * packet loss, but is not going to give us better rcodes should we actually have | |
920 | * managed to get them already at UDP level. */ | |
921 | ||
44db02d0 LP |
922 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { |
923 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
924 | dns_transaction_retry(t, true); | |
925 | return; | |
926 | } | |
927 | ||
928 | /* Give up, accept the rcode */ | |
d001e0a3 LP |
929 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
930 | break; | |
931 | } | |
932 | ||
933 | /* Reduce this feature level by one and try again. */ | |
934 | t->clamp_feature_level = t->current_feature_level - 1; | |
935 | ||
936 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
937 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
938 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
939 | ||
940 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 941 | return; |
eb08640a LP |
942 | } |
943 | ||
944 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
945 | /* This server refused our request? If so, try again, use a different server */ | |
946 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
947 | dns_transaction_retry(t, true /* pick a new server */); | |
948 | return; | |
949 | } | |
950 | ||
951 | if (DNS_PACKET_TC(p)) | |
274b8748 | 952 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
953 | |
954 | break; | |
8af5b883 | 955 | |
9df3ba6c TG |
956 | case DNS_PROTOCOL_LLMNR: |
957 | case DNS_PROTOCOL_MDNS: | |
958 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 959 | break; |
8af5b883 | 960 | |
9df3ba6c | 961 | default: |
8af5b883 | 962 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
963 | } |
964 | ||
ec2c5e43 | 965 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
966 | |
967 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
968 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
969 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
970 | return; | |
971 | } | |
972 | ||
f757cd85 LP |
973 | log_debug("Reply truncated, retrying via TCP."); |
974 | ||
ec2c5e43 LP |
975 | /* Response was truncated, let's try again with good old TCP */ |
976 | r = dns_transaction_open_tcp(t); | |
977 | if (r == -ESRCH) { | |
978 | /* No servers found? Damn! */ | |
979 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
980 | return; | |
981 | } | |
91adc4db LP |
982 | if (r == -EOPNOTSUPP) { |
983 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
984 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
985 | return; | |
986 | } | |
ec2c5e43 | 987 | if (r < 0) { |
8af5b883 | 988 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 989 | * we immediately give up */ |
7cc6ed7b LP |
990 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
991 | goto fail; | |
ec2c5e43 LP |
992 | |
993 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 994 | dns_transaction_retry(t, true); |
ec2c5e43 | 995 | } |
2a6658ef LP |
996 | |
997 | return; | |
ec2c5e43 LP |
998 | } |
999 | ||
de54e62b | 1000 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
1001 | r = dns_packet_extract(p); |
1002 | if (r < 0) { | |
1003 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1004 | return; | |
1005 | } | |
1006 | ||
ed9717fc | 1007 | if (t->server) { |
d001e0a3 LP |
1008 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1009 | * rcode and subsequently downgraded the protocol */ | |
1010 | ||
1011 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1012 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1013 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1014 | ||
1015 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1016 | if (!p->opt) |
1017 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1018 | ||
d001e0a3 | 1019 | /* Report that we successfully received a packet */ |
ed9717fc LP |
1020 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); |
1021 | } | |
de54e62b | 1022 | |
c02cf2f4 LP |
1023 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1024 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1025 | if (r < 0) |
1026 | goto fail; | |
c02cf2f4 LP |
1027 | if (r > 0) /* Transaction got restarted... */ |
1028 | return; | |
1029 | ||
8b419837 | 1030 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
b5efcf29 | 1031 | |
8b419837 DR |
1032 | /* When dealing with protocols other than mDNS only consider responses with |
1033 | * equivalent query section to the request. For mDNS this check doesn't make | |
1034 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1035 | * contain any questions in the Question Section". */ | |
1036 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1037 | r = dns_packet_is_reply_for(p, t->key); | |
1038 | if (r < 0) | |
1039 | goto fail; | |
1040 | if (r == 0) { | |
1041 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1042 | return; | |
1043 | } | |
547493c5 | 1044 | } |
29815b6c | 1045 | |
547493c5 DM |
1046 | /* Install the answer as answer to the transaction */ |
1047 | dns_answer_unref(t->answer); | |
1048 | t->answer = dns_answer_ref(p->answer); | |
1049 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1050 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1051 | t->answer_authenticated = false; |
79e24931 | 1052 | |
eac7cda2 LP |
1053 | r = dns_transaction_fix_rcode(t); |
1054 | if (r < 0) | |
1055 | goto fail; | |
1056 | ||
51e399bc LP |
1057 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1058 | t->block_gc++; | |
547973de | 1059 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1060 | t->block_gc--; |
1061 | ||
1062 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1063 | if (!dns_transaction_gc(t)) | |
1064 | return; | |
1065 | ||
1066 | /* Requesting additional keys might have resulted in | |
1067 | * this transaction to fail, since the auxiliary | |
1068 | * request failed for some reason. If so, we are not | |
1069 | * in pending state anymore, and we should exit | |
1070 | * quickly. */ | |
1071 | if (t->state != DNS_TRANSACTION_PENDING) | |
1072 | return; | |
7cc6ed7b LP |
1073 | if (r < 0) |
1074 | goto fail; | |
547973de LP |
1075 | if (r > 0) { |
1076 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1077 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1078 | dns_transaction_close_connection(t); |
1079 | dns_transaction_stop_timeout(t); | |
547973de LP |
1080 | return; |
1081 | } | |
547493c5 | 1082 | } |
ec2c5e43 | 1083 | |
547973de | 1084 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1085 | return; |
1086 | ||
1087 | fail: | |
1088 | t->answer_errno = -r; | |
1089 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1090 | } |
1091 | ||
c19ffd9f TG |
1092 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1093 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1094 | DnsTransaction *t = userdata; | |
1095 | int r; | |
1096 | ||
1097 | assert(t); | |
1098 | assert(t->scope); | |
1099 | ||
1100 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1101 | if (ERRNO_IS_DISCONNECT(-r)) { |
1102 | usec_t usec; | |
c19ffd9f | 1103 | |
7e1851e3 LP |
1104 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1105 | * recvmsg(). Treat this like a lost packet. */ | |
1106 | ||
92ec902a | 1107 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1108 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1109 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 | 1110 | |
d001e0a3 | 1111 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1112 | return 0; |
1113 | } | |
1114 | if (r < 0) { | |
7cc6ed7b LP |
1115 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1116 | t->answer_errno = -r; | |
7e1851e3 LP |
1117 | return 0; |
1118 | } | |
1119 | ||
1120 | r = dns_packet_validate_reply(p); | |
1121 | if (r < 0) { | |
1122 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1123 | return 0; | |
1124 | } | |
1125 | if (r == 0) { | |
e09f605e | 1126 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1127 | return 0; |
1128 | } | |
1129 | ||
1130 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1131 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1132 | return 0; |
1133 | } | |
c19ffd9f | 1134 | |
7e1851e3 | 1135 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1136 | return 0; |
1137 | } | |
1138 | ||
49cce12d | 1139 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1140 | int r; |
1141 | ||
1142 | assert(t); | |
c19ffd9f | 1143 | |
519ef046 | 1144 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1145 | |
519ef046 | 1146 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1147 | if (r < 0) |
1148 | return r; | |
c19ffd9f | 1149 | |
274b8748 | 1150 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP) |
7d581a65 | 1151 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1152 | |
92ec902a | 1153 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1154 | return -EOPNOTSUPP; |
1155 | ||
519ef046 LP |
1156 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1157 | int fd; | |
1158 | ||
1159 | dns_transaction_close_connection(t); | |
c19ffd9f | 1160 | |
519ef046 LP |
1161 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1162 | if (fd < 0) | |
1163 | return fd; | |
1164 | ||
1165 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1166 | if (r < 0) { | |
1167 | safe_close(fd); | |
1168 | return r; | |
1169 | } | |
1170 | ||
aa4a9deb | 1171 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1172 | t->dns_udp_fd = fd; |
1173 | } | |
1174 | ||
274b8748 | 1175 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1176 | if (r < 0) |
1177 | return r; | |
1178 | } else | |
1179 | dns_transaction_close_connection(t); | |
1180 | ||
1181 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1182 | if (r < 0) |
1183 | return r; | |
c19ffd9f | 1184 | |
519ef046 | 1185 | dns_transaction_reset_answer(t); |
be808ea0 | 1186 | |
471d40d9 | 1187 | return 0; |
c19ffd9f TG |
1188 | } |
1189 | ||
ec2c5e43 LP |
1190 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1191 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1192 | |
1193 | assert(s); | |
1194 | assert(t); | |
1195 | ||
ef7ce6df DM |
1196 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1197 | /* Timeout reached? Increase the timeout for the server used */ | |
1198 | switch (t->scope->protocol) { | |
49cce12d | 1199 | |
ef7ce6df DM |
1200 | case DNS_PROTOCOL_DNS: |
1201 | assert(t->server); | |
274b8748 | 1202 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1203 | break; |
49cce12d | 1204 | |
ef7ce6df DM |
1205 | case DNS_PROTOCOL_LLMNR: |
1206 | case DNS_PROTOCOL_MDNS: | |
1207 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1208 | break; |
49cce12d | 1209 | |
ef7ce6df DM |
1210 | default: |
1211 | assert_not_reached("Invalid DNS protocol."); | |
1212 | } | |
1213 | ||
1214 | if (t->initial_jitter_scheduled) | |
1215 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1216 | } |
1217 | ||
423659ab LP |
1218 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1219 | ||
d001e0a3 | 1220 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1221 | return 0; |
1222 | } | |
1223 | ||
9df3ba6c TG |
1224 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1225 | assert(t); | |
1226 | assert(t->scope); | |
1227 | ||
dc349f5f | 1228 | |
9df3ba6c | 1229 | switch (t->scope->protocol) { |
49cce12d | 1230 | |
9df3ba6c | 1231 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1232 | |
1233 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1234 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1235 | * needlessly. */ | |
1236 | if (t->stream) | |
1237 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1238 | ||
9df3ba6c | 1239 | assert(t->server); |
9df3ba6c | 1240 | return t->server->resend_timeout; |
49cce12d | 1241 | |
9df3ba6c | 1242 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1243 | assert(t->n_attempts > 0); |
53fda2bb DR |
1244 | if (t->probing) |
1245 | return MDNS_PROBING_INTERVAL_USEC; | |
1246 | else | |
1247 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1248 | |
11a27c2e | 1249 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1250 | return t->scope->resend_timeout; |
49cce12d | 1251 | |
9df3ba6c TG |
1252 | default: |
1253 | assert_not_reached("Invalid DNS protocol."); | |
1254 | } | |
1255 | } | |
1256 | ||
c842ff24 | 1257 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1258 | int r; |
1259 | ||
1260 | assert(t); | |
1261 | ||
f535705a | 1262 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1263 | |
edbcc1fd LP |
1264 | r = dns_scope_network_good(t->scope); |
1265 | if (r < 0) | |
1266 | return r; | |
1267 | if (r == 0) { | |
1268 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1269 | return 0; | |
1270 | } | |
1271 | ||
ec2c5e43 LP |
1272 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1273 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1274 | return 0; | |
1275 | } | |
1276 | ||
cbe4216d | 1277 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1278 | /* If we already tried via a stream, then we don't |
1279 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1280 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1281 | return 0; | |
1282 | } | |
1283 | ||
1284 | t->n_attempts++; | |
9df3ba6c | 1285 | t->start_usec = ts; |
c61d2b44 LP |
1286 | |
1287 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1288 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1289 | |
0d2cd476 LP |
1290 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1291 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1292 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1293 | if (r < 0) |
1294 | return r; | |
1295 | if (r > 0) { | |
1296 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1297 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1298 | t->answer_authenticated = true; |
0d2cd476 LP |
1299 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1300 | return 0; | |
1301 | } | |
b2b796b8 | 1302 | |
1c02e7ba | 1303 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1304 | t->key->type == DNS_TYPE_DS) { |
1305 | ||
1306 | /* Hmm, this is a request for the root DS? A | |
1307 | * DS RR doesn't exist in the root zone, and | |
1308 | * if our trust anchor didn't know it either, | |
1309 | * this means we cannot do any DNSSEC logic | |
1310 | * anymore. */ | |
1311 | ||
1ed8c0fb | 1312 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1313 | /* We are in downgrade mode. In this |
1314 | * case, synthesize an unsigned empty | |
1315 | * response, so that the any lookup | |
1316 | * depending on this one can continue | |
1317 | * assuming there was no DS, and hence | |
1318 | * the root zone was unsigned. */ | |
1319 | ||
1320 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1321 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1322 | t->answer_authenticated = false; | |
1323 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1324 | } else | |
1325 | /* If we are not in downgrade mode, | |
1326 | * then fail the lookup, because we | |
1327 | * cannot reasonably answer it. There | |
1328 | * might be DS RRs, but we don't know | |
1329 | * them, and the DNS server won't tell | |
1330 | * them to us (and even if it would, | |
202b76ae | 1331 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1332 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1333 | ||
1334 | return 0; | |
1335 | } | |
0d2cd476 LP |
1336 | } |
1337 | ||
1338 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1339 | * for probing or verifying a zone item. */ |
547973de | 1340 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1341 | |
97ebebbc | 1342 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1343 | if (r < 0) |
1344 | return r; | |
1345 | if (r > 0) { | |
ae6a4bbf | 1346 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1347 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1348 | t->answer_authenticated = true; |
d746bb3e LP |
1349 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1350 | return 0; | |
1351 | } | |
1352 | } | |
1353 | ||
4d926a69 LP |
1354 | /* Check the cache, but only if this transaction is not used |
1355 | * for probing or verifying a zone item. */ | |
547973de | 1356 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1357 | |
4d926a69 LP |
1358 | /* Before trying the cache, let's make sure we figured out a |
1359 | * server to use. Should this cause a change of server this | |
1360 | * might flush the cache. */ | |
5cdb8930 | 1361 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1362 | |
4d926a69 LP |
1363 | /* Let's then prune all outdated entries */ |
1364 | dns_cache_prune(&t->scope->cache); | |
1365 | ||
17c8de63 | 1366 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1367 | if (r < 0) |
1368 | return r; | |
1369 | if (r > 0) { | |
c3bc53e6 | 1370 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1371 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1372 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1373 | else | |
3bbdc31d | 1374 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1375 | return 0; |
1376 | } | |
ec2c5e43 LP |
1377 | } |
1378 | ||
1effe965 DM |
1379 | return 1; |
1380 | } | |
1381 | ||
0afa57e2 DM |
1382 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1383 | ||
1384 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1385 | bool add_known_answers = false; |
0afa57e2 | 1386 | DnsTransaction *other; |
0d5ee47d DR |
1387 | Iterator i; |
1388 | DnsResourceKey *tkey; | |
1389 | _cleanup_set_free_ Set *keys = NULL; | |
0afa57e2 | 1390 | unsigned qdcount; |
0d5ee47d | 1391 | unsigned nscount = 0; |
0afa57e2 DM |
1392 | usec_t ts; |
1393 | int r; | |
1394 | ||
1395 | assert(t); | |
1396 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1397 | ||
e5abebab | 1398 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1399 | t->sent = dns_packet_unref(t->sent); |
1400 | ||
1401 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1402 | if (r < 0) | |
1403 | return r; | |
1404 | ||
58ab31d5 | 1405 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1406 | if (r < 0) |
1407 | return r; | |
1408 | ||
1409 | qdcount = 1; | |
1410 | ||
7778dfff DM |
1411 | if (dns_key_is_shared(t->key)) |
1412 | add_known_answers = true; | |
1413 | ||
0d5ee47d DR |
1414 | if (t->key->type == DNS_TYPE_ANY) { |
1415 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1416 | if (r < 0) | |
1417 | return r; | |
1418 | ||
1419 | r = set_put(keys, t->key); | |
1420 | if (r < 0) | |
1421 | return r; | |
1422 | } | |
1423 | ||
0afa57e2 DM |
1424 | /* |
1425 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1426 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1427 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1428 | */ | |
1429 | ||
1430 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1431 | ||
1432 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1433 | ||
1434 | /* Skip ourselves */ | |
1435 | if (other == t) | |
1436 | continue; | |
1437 | ||
1438 | if (other->state != DNS_TRANSACTION_PENDING) | |
1439 | continue; | |
1440 | ||
1441 | if (other->next_attempt_after > ts) | |
1442 | continue; | |
1443 | ||
1444 | if (qdcount >= UINT16_MAX) | |
1445 | break; | |
1446 | ||
58ab31d5 | 1447 | r = dns_packet_append_key(p, other->key, 0, NULL); |
0afa57e2 DM |
1448 | |
1449 | /* | |
1450 | * If we can't stuff more questions into the packet, just give up. | |
1451 | * One of the 'other' transactions will fire later and take care of the rest. | |
1452 | */ | |
1453 | if (r == -EMSGSIZE) | |
1454 | break; | |
1455 | ||
1456 | if (r < 0) | |
1457 | return r; | |
1458 | ||
c842ff24 | 1459 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1460 | if (r <= 0) |
1461 | continue; | |
1462 | ||
1463 | ts += transaction_get_resend_timeout(other); | |
1464 | ||
1465 | r = sd_event_add_time( | |
1466 | other->scope->manager->event, | |
1467 | &other->timeout_event_source, | |
1468 | clock_boottime_or_monotonic(), | |
1469 | ts, 0, | |
1470 | on_transaction_timeout, other); | |
1471 | if (r < 0) | |
1472 | return r; | |
1473 | ||
ff537038 | 1474 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1475 | |
0afa57e2 DM |
1476 | other->state = DNS_TRANSACTION_PENDING; |
1477 | other->next_attempt_after = ts; | |
1478 | ||
313cefa1 | 1479 | qdcount++; |
7778dfff DM |
1480 | |
1481 | if (dns_key_is_shared(other->key)) | |
1482 | add_known_answers = true; | |
0d5ee47d DR |
1483 | |
1484 | if (other->key->type == DNS_TYPE_ANY) { | |
1485 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1486 | if (r < 0) | |
1487 | return r; | |
1488 | ||
1489 | r = set_put(keys, other->key); | |
1490 | if (r < 0) | |
1491 | return r; | |
1492 | } | |
0afa57e2 DM |
1493 | } |
1494 | ||
1495 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1496 | |
7778dfff DM |
1497 | /* Append known answer section if we're asking for any shared record */ |
1498 | if (add_known_answers) { | |
1499 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1500 | if (r < 0) | |
1501 | return r; | |
1502 | } | |
1503 | ||
0d5ee47d DR |
1504 | SET_FOREACH(tkey, keys, i) { |
1505 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
1506 | bool tentative; | |
1507 | ||
1508 | r = dns_zone_lookup(&t->scope->zone, tkey, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1509 | if (r < 0) | |
1510 | return r; | |
1511 | ||
1512 | r = dns_packet_append_answer(p, answer); | |
1513 | if (r < 0) | |
1514 | return r; | |
1515 | ||
1516 | nscount += dns_answer_size(answer); | |
1517 | } | |
1518 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1519 | ||
1cc6c93a | 1520 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1521 | |
1522 | return 0; | |
1523 | } | |
1524 | ||
1525 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1526 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1527 | int r; | |
1528 | ||
1529 | assert(t); | |
1530 | ||
1531 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1532 | return dns_transaction_make_packet_mdns(t); | |
1533 | ||
1534 | if (t->sent) | |
1535 | return 0; | |
1536 | ||
b652d4a2 | 1537 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1538 | if (r < 0) |
1539 | return r; | |
1540 | ||
58ab31d5 | 1541 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1542 | if (r < 0) |
1543 | return r; | |
1544 | ||
1545 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1546 | DNS_PACKET_HEADER(p)->id = t->id; | |
1547 | ||
1cc6c93a | 1548 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1549 | |
1550 | return 0; | |
1551 | } | |
1552 | ||
1effe965 DM |
1553 | int dns_transaction_go(DnsTransaction *t) { |
1554 | usec_t ts; | |
1555 | int r; | |
202b76ae | 1556 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1557 | |
1558 | assert(t); | |
1559 | ||
5278bbfe LP |
1560 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1561 | * now. */ | |
1562 | ||
1effe965 | 1563 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1564 | |
c842ff24 | 1565 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1566 | if (r <= 0) |
1567 | return r; | |
1568 | ||
202b76ae | 1569 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1570 | t->id, |
202b76ae | 1571 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1572 | dns_protocol_to_string(t->scope->protocol), |
1573 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1574 | af_to_name_short(t->scope->family)); |
1effe965 | 1575 | |
ef7ce6df | 1576 | if (!t->initial_jitter_scheduled && |
3742095b | 1577 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1578 | usec_t jitter, accuracy; |
6e068472 LP |
1579 | |
1580 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1581 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1582 | ||
ef7ce6df | 1583 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1584 | |
1585 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1586 | |
1587 | switch (t->scope->protocol) { | |
519ef046 | 1588 | |
ea12bcc7 DM |
1589 | case DNS_PROTOCOL_LLMNR: |
1590 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1591 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1592 | break; | |
519ef046 | 1593 | |
ea12bcc7 DM |
1594 | case DNS_PROTOCOL_MDNS: |
1595 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1596 | jitter += MDNS_JITTER_MIN_USEC; | |
1597 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1598 | break; | |
1599 | default: | |
1600 | assert_not_reached("bad protocol"); | |
1601 | } | |
6e068472 LP |
1602 | |
1603 | r = sd_event_add_time( | |
1604 | t->scope->manager->event, | |
1605 | &t->timeout_event_source, | |
1606 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1607 | ts + jitter, accuracy, |
6e068472 LP |
1608 | on_transaction_timeout, t); |
1609 | if (r < 0) | |
1610 | return r; | |
1611 | ||
aa4a9deb LP |
1612 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1613 | ||
6e068472 | 1614 | t->n_attempts = 0; |
a9da14e1 | 1615 | t->next_attempt_after = ts; |
6e068472 LP |
1616 | t->state = DNS_TRANSACTION_PENDING; |
1617 | ||
ea12bcc7 | 1618 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1619 | return 0; |
1620 | } | |
1621 | ||
ec2c5e43 LP |
1622 | /* Otherwise, we need to ask the network */ |
1623 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1624 | if (r < 0) |
1625 | return r; | |
1626 | ||
1627 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1628 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1629 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1630 | |
1631 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1632 | * always be made via TCP on LLMNR */ | |
1633 | r = dns_transaction_open_tcp(t); | |
1634 | } else { | |
be808ea0 TG |
1635 | /* Try via UDP, and if that fails due to large size or lack of |
1636 | * support try via TCP */ | |
49cce12d | 1637 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1638 | if (r == -EMSGSIZE) |
1639 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1640 | else if (r == -EAGAIN) |
034e8031 | 1641 | log_debug("Sending query via TCP since server doesn't support UDP."); |
4c701096 | 1642 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
ec2c5e43 LP |
1643 | r = dns_transaction_open_tcp(t); |
1644 | } | |
be808ea0 | 1645 | |
ec2c5e43 LP |
1646 | if (r == -ESRCH) { |
1647 | /* No servers to send this to? */ | |
1648 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1649 | return 0; | |
91adc4db LP |
1650 | } |
1651 | if (r == -EOPNOTSUPP) { | |
1652 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1653 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1654 | return 0; | |
1655 | } | |
0791110f | 1656 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1657 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1658 | * answer this request with this protocol. */ |
1659 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1660 | return 0; | |
1661 | } | |
91adc4db | 1662 | if (r < 0) { |
7cc6ed7b LP |
1663 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1664 | return r; | |
13b551ac | 1665 | |
ec2c5e43 | 1666 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1667 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1668 | |
1669 | return dns_transaction_go(t); | |
1670 | } | |
1671 | ||
a9da14e1 DM |
1672 | ts += transaction_get_resend_timeout(t); |
1673 | ||
9a015429 LP |
1674 | r = sd_event_add_time( |
1675 | t->scope->manager->event, | |
1676 | &t->timeout_event_source, | |
1677 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1678 | ts, 0, |
9a015429 | 1679 | on_transaction_timeout, t); |
ec2c5e43 LP |
1680 | if (r < 0) |
1681 | return r; | |
1682 | ||
aa4a9deb LP |
1683 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1684 | ||
ec2c5e43 | 1685 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1686 | t->next_attempt_after = ts; |
1687 | ||
ec2c5e43 LP |
1688 | return 1; |
1689 | } | |
1690 | ||
f2992dc1 LP |
1691 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1692 | DnsTransaction *n; | |
1693 | Iterator i; | |
1694 | int r; | |
1695 | ||
1696 | assert(t); | |
1697 | assert(aux); | |
1698 | ||
1699 | /* Try to find cyclic dependencies between transaction objects */ | |
1700 | ||
1701 | if (t == aux) | |
1702 | return 1; | |
1703 | ||
3eb6aa00 | 1704 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1705 | r = dns_transaction_find_cyclic(t, n); |
1706 | if (r != 0) | |
1707 | return r; | |
1708 | } | |
1709 | ||
3eb6aa00 | 1710 | return 0; |
f2992dc1 LP |
1711 | } |
1712 | ||
547973de LP |
1713 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1714 | DnsTransaction *aux; | |
1715 | int r; | |
1716 | ||
1717 | assert(t); | |
1718 | assert(ret); | |
1719 | assert(key); | |
1720 | ||
1721 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1722 | if (!aux) { | |
1723 | r = dns_transaction_new(&aux, t->scope, key); | |
1724 | if (r < 0) | |
1725 | return r; | |
1726 | } else { | |
1727 | if (set_contains(t->dnssec_transactions, aux)) { | |
1728 | *ret = aux; | |
1729 | return 0; | |
1730 | } | |
f2992dc1 LP |
1731 | |
1732 | r = dns_transaction_find_cyclic(t, aux); | |
1733 | if (r < 0) | |
1734 | return r; | |
1735 | if (r > 0) { | |
202b76ae ZJS |
1736 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1737 | ||
1738 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1739 | aux->id, |
202b76ae | 1740 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1741 | t->id, |
202b76ae ZJS |
1742 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1743 | ||
f2992dc1 LP |
1744 | return -ELOOP; |
1745 | } | |
547973de LP |
1746 | } |
1747 | ||
1748 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1749 | if (r < 0) | |
1750 | goto gc; | |
1751 | ||
1752 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1753 | if (r < 0) | |
35aa04e9 LP |
1754 | goto gc; |
1755 | ||
1756 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1757 | if (r < 0) | |
547973de LP |
1758 | goto gc; |
1759 | ||
1760 | r = set_put(t->dnssec_transactions, aux); | |
1761 | if (r < 0) | |
1762 | goto gc; | |
1763 | ||
1764 | r = set_put(aux->notify_transactions, t); | |
1765 | if (r < 0) { | |
1766 | (void) set_remove(t->dnssec_transactions, aux); | |
1767 | goto gc; | |
1768 | } | |
1769 | ||
1770 | *ret = aux; | |
1771 | return 1; | |
1772 | ||
1773 | gc: | |
1774 | dns_transaction_gc(aux); | |
1775 | return r; | |
1776 | } | |
1777 | ||
1778 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1779 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1780 | DnsTransaction *aux; | |
1781 | int r; | |
1782 | ||
1783 | assert(t); | |
1784 | assert(key); | |
1785 | ||
1786 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1787 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1788 | if (r < 0) |
1789 | return r; | |
1790 | if (r > 0) { | |
1791 | r = dns_answer_extend(&t->validated_keys, a); | |
1792 | if (r < 0) | |
1793 | return r; | |
1794 | ||
1795 | return 0; | |
1796 | } | |
1797 | ||
1798 | /* This didn't work, ask for it via the network/cache then. */ | |
1799 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1800 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1801 | return 0; | |
547973de LP |
1802 | if (r < 0) |
1803 | return r; | |
1804 | ||
1805 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1806 | r = dns_transaction_go(aux); | |
1807 | if (r < 0) | |
1808 | return r; | |
1809 | } | |
1810 | ||
f2992dc1 | 1811 | return 1; |
547973de LP |
1812 | } |
1813 | ||
8a516214 LP |
1814 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1815 | int r; | |
1816 | ||
1817 | assert(t); | |
1818 | ||
c629ff58 | 1819 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1820 | * database, either in the global one, or the link-local |
1821 | * one. */ | |
1822 | ||
1823 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1824 | if (r != 0) | |
1825 | return r; | |
1826 | ||
1827 | if (!t->scope->link) | |
1828 | return 0; | |
1829 | ||
1830 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1831 | } | |
1832 | ||
105e1512 LP |
1833 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1834 | int r; | |
1835 | ||
1836 | assert(t); | |
1837 | ||
1838 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1839 | * RRs to prove it */ | |
1840 | ||
1841 | r = dns_transaction_has_positive_answer(t, NULL); | |
1842 | if (r < 0) | |
1843 | return r; | |
1844 | if (r > 0) | |
1845 | return false; | |
1846 | ||
8e54f5d9 LP |
1847 | /* Is this key explicitly listed as a negative trust anchor? |
1848 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1849 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1850 | if (r < 0) |
1851 | return r; | |
1852 | if (r > 0) | |
1853 | return false; | |
1854 | ||
105e1512 LP |
1855 | /* The answer does not contain any RRs that match to the |
1856 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1857 | * included. If not, the answer is unsigned. */ | |
1858 | ||
1859 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1860 | if (r < 0) | |
1861 | return r; | |
1862 | if (r > 0) | |
1863 | return false; | |
1864 | ||
1865 | return true; | |
1866 | } | |
1867 | ||
1868 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1869 | int r; | |
1870 | ||
1871 | assert(t); | |
1872 | assert(rr); | |
1873 | ||
1874 | /* Check if the specified RR is the "primary" response, | |
1875 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1876 | * CNAME/DNAME for it. */ |
105e1512 LP |
1877 | |
1878 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1879 | if (r != 0) | |
1880 | return r; | |
1881 | ||
4cb94977 | 1882 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
1883 | } |
1884 | ||
92ec902a LP |
1885 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
1886 | assert(t); | |
1887 | ||
1888 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
1889 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
1890 | ||
1891 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
1892 | return false; | |
1893 | ||
1894 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
1895 | * be supported, hence return true. */ | |
1896 | if (!t->server) | |
1897 | return true; | |
1898 | ||
d001e0a3 LP |
1899 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
1900 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
1901 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
1902 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
1903 | |
1904 | return dns_server_dnssec_supported(t->server); | |
1905 | } | |
1906 | ||
1907 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
1908 | DnsTransaction *dt; | |
1909 | Iterator i; | |
1910 | ||
1911 | assert(t); | |
1912 | ||
1913 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
1914 | ||
1915 | if (!dns_transaction_dnssec_supported(t)) | |
1916 | return false; | |
1917 | ||
1918 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
1919 | if (!dns_transaction_dnssec_supported(dt)) | |
1920 | return false; | |
1921 | ||
1922 | return true; | |
1923 | } | |
1924 | ||
547973de LP |
1925 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
1926 | DnsResourceRecord *rr; | |
105e1512 | 1927 | |
547973de LP |
1928 | int r; |
1929 | ||
1930 | assert(t); | |
1931 | ||
105e1512 LP |
1932 | /* |
1933 | * Retrieve all auxiliary RRs for the answer we got, so that | |
1934 | * we can verify signatures or prove that RRs are rightfully | |
1935 | * unsigned. Specifically: | |
1936 | * | |
1937 | * - For RRSIG we get the matching DNSKEY | |
1938 | * - For DNSKEY we get the matching DS | |
1939 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 1940 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 1941 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
1942 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
1943 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
1944 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
1945 | */ | |
1946 | ||
b652d4a2 | 1947 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 1948 | return 0; |
92ec902a LP |
1949 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
1950 | return 0; /* We only need to validate stuff from the network */ | |
1951 | if (!dns_transaction_dnssec_supported(t)) | |
1952 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 1953 | |
547973de LP |
1954 | DNS_ANSWER_FOREACH(rr, t->answer) { |
1955 | ||
105e1512 LP |
1956 | if (dns_type_is_pseudo(rr->key->type)) |
1957 | continue; | |
1958 | ||
8e54f5d9 | 1959 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 1960 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
1961 | if (r < 0) |
1962 | return r; | |
1963 | if (r > 0) | |
1964 | continue; | |
1965 | ||
547973de LP |
1966 | switch (rr->key->type) { |
1967 | ||
1968 | case DNS_TYPE_RRSIG: { | |
1969 | /* For each RRSIG we request the matching DNSKEY */ | |
1970 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
1971 | ||
1972 | /* If this RRSIG is about a DNSKEY RR and the | |
1973 | * signer is the same as the owner, then we | |
1974 | * already have the DNSKEY, and we don't have | |
1975 | * to look for more. */ | |
1976 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 1977 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
1978 | if (r < 0) |
1979 | return r; | |
1980 | if (r > 0) | |
1981 | continue; | |
1982 | } | |
1983 | ||
105e1512 LP |
1984 | /* If the signer is not a parent of our |
1985 | * original query, then this is about an | |
1986 | * auxiliary RRset, but not anything we asked | |
1987 | * for. In this case we aren't interested, | |
1988 | * because we don't want to request additional | |
1989 | * RRs for stuff we didn't really ask for, and | |
1990 | * also to avoid request loops, where | |
1991 | * additional RRs from one transaction result | |
1992 | * in another transaction whose additonal RRs | |
1993 | * point back to the original transaction, and | |
1994 | * we deadlock. */ | |
1c02e7ba | 1995 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
1996 | if (r < 0) |
1997 | return r; | |
1998 | if (r == 0) | |
1999 | continue; | |
2000 | ||
2001 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2002 | if (!dnskey) | |
2003 | return -ENOMEM; | |
2004 | ||
1c02e7ba ZJS |
2005 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2006 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2007 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2008 | if (r < 0) | |
2009 | return r; | |
2010 | break; | |
2011 | } | |
2012 | ||
2013 | case DNS_TYPE_DNSKEY: { | |
2014 | /* For each DNSKEY we request the matching DS */ | |
2015 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2016 | ||
105e1512 LP |
2017 | /* If the DNSKEY we are looking at is not for |
2018 | * zone we are interested in, nor any of its | |
2019 | * parents, we aren't interested, and don't | |
2020 | * request it. After all, we don't want to end | |
2021 | * up in request loops, and want to keep | |
2022 | * additional traffic down. */ | |
2023 | ||
1c02e7ba | 2024 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2025 | if (r < 0) |
2026 | return r; | |
2027 | if (r == 0) | |
2028 | continue; | |
2029 | ||
1c02e7ba | 2030 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2031 | if (!ds) |
2032 | return -ENOMEM; | |
2033 | ||
1c02e7ba ZJS |
2034 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2035 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2036 | r = dns_transaction_request_dnssec_rr(t, ds); |
2037 | if (r < 0) | |
2038 | return r; | |
547973de | 2039 | |
105e1512 LP |
2040 | break; |
2041 | } | |
2042 | ||
105e1512 LP |
2043 | case DNS_TYPE_SOA: |
2044 | case DNS_TYPE_NS: { | |
2045 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2046 | ||
2047 | /* For an unsigned SOA or NS, try to acquire | |
2048 | * the matching DS RR, as we are at a zone cut | |
2049 | * then, and whether a DS exists tells us | |
2050 | * whether the zone is signed. Do so only if | |
2051 | * this RR matches our original question, | |
2052 | * however. */ | |
2053 | ||
2054 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
2055 | if (r < 0) | |
2056 | return r; | |
6993d264 LP |
2057 | if (r == 0) { |
2058 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
2059 | * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry? | |
2060 | * If so, we need to validate it, too. */ | |
2061 | ||
2062 | r = dns_answer_match_key(t->answer, t->key, NULL); | |
2063 | if (r < 0) | |
2064 | return r; | |
2065 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2066 | * it. */ | |
2067 | continue; | |
2068 | } | |
105e1512 LP |
2069 | |
2070 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2071 | if (r < 0) | |
2072 | return r; | |
2073 | if (r > 0) | |
2074 | continue; | |
2075 | ||
1c02e7ba | 2076 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2077 | if (!ds) |
2078 | return -ENOMEM; | |
2079 | ||
1c02e7ba ZJS |
2080 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2081 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2082 | r = dns_transaction_request_dnssec_rr(t, ds); |
2083 | if (r < 0) | |
2084 | return r; | |
2085 | ||
2086 | break; | |
105e1512 LP |
2087 | } |
2088 | ||
b63fca62 | 2089 | case DNS_TYPE_DS: |
105e1512 LP |
2090 | case DNS_TYPE_CNAME: |
2091 | case DNS_TYPE_DNAME: { | |
2092 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2093 | const char *name; | |
2094 | ||
2095 | /* CNAMEs and DNAMEs cannot be located at a | |
2096 | * zone apex, hence ask for the parent SOA for | |
2097 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2098 | * apex. But do all that only if this is | |
2099 | * actually a response to our original | |
b63fca62 LP |
2100 | * question. |
2101 | * | |
2102 | * Similar for DS RRs, which are signed when | |
2103 | * the parent SOA is signed. */ | |
105e1512 LP |
2104 | |
2105 | r = dns_transaction_is_primary_response(t, rr); | |
2106 | if (r < 0) | |
2107 | return r; | |
2108 | if (r == 0) | |
2109 | continue; | |
2110 | ||
2111 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2112 | if (r < 0) | |
2113 | return r; | |
2114 | if (r > 0) | |
2115 | continue; | |
2116 | ||
43e6779a LP |
2117 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2118 | if (r < 0) | |
2119 | return r; | |
2120 | if (r > 0) | |
2121 | continue; | |
2122 | ||
1c02e7ba | 2123 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2124 | r = dns_name_parent(&name); |
2125 | if (r < 0) | |
2126 | return r; | |
2127 | if (r == 0) | |
2128 | continue; | |
2129 | ||
2130 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2131 | if (!soa) | |
2132 | return -ENOMEM; | |
2133 | ||
1c02e7ba ZJS |
2134 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2135 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2136 | r = dns_transaction_request_dnssec_rr(t, soa); |
2137 | if (r < 0) | |
2138 | return r; | |
2139 | ||
2140 | break; | |
2141 | } | |
2142 | ||
2143 | default: { | |
2144 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2145 | ||
b63fca62 LP |
2146 | /* For other unsigned RRsets (including |
2147 | * NSEC/NSEC3!), look for proof the zone is | |
2148 | * unsigned, by requesting the SOA RR of the | |
2149 | * zone. However, do so only if they are | |
2150 | * directly relevant to our original | |
105e1512 LP |
2151 | * question. */ |
2152 | ||
2153 | r = dns_transaction_is_primary_response(t, rr); | |
2154 | if (r < 0) | |
2155 | return r; | |
2156 | if (r == 0) | |
2157 | continue; | |
2158 | ||
2159 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2160 | if (r < 0) | |
2161 | return r; | |
2162 | if (r > 0) | |
2163 | continue; | |
2164 | ||
1c02e7ba | 2165 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2166 | if (!soa) |
2167 | return -ENOMEM; | |
2168 | ||
1c02e7ba ZJS |
2169 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2170 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2171 | r = dns_transaction_request_dnssec_rr(t, soa); |
2172 | if (r < 0) | |
2173 | return r; | |
2174 | break; | |
547973de LP |
2175 | }} |
2176 | } | |
2177 | ||
105e1512 LP |
2178 | /* Above, we requested everything necessary to validate what |
2179 | * we got. Now, let's request what we need to validate what we | |
2180 | * didn't get... */ | |
2181 | ||
2182 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2183 | if (r < 0) | |
2184 | return r; | |
2185 | if (r > 0) { | |
2186 | const char *name; | |
4bbc06cc | 2187 | uint16_t type = 0; |
105e1512 | 2188 | |
1c02e7ba | 2189 | name = dns_resource_key_name(t->key); |
105e1512 | 2190 | |
4bbc06cc LP |
2191 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2192 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2193 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2194 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2195 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2196 | * to see if that is signed. */ | |
105e1512 | 2197 | |
4bbc06cc | 2198 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2199 | r = dns_name_parent(&name); |
4bbc06cc LP |
2200 | if (r > 0) { |
2201 | type = DNS_TYPE_SOA; | |
2202 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2203 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2204 | } else |
105e1512 | 2205 | name = NULL; |
4bbc06cc LP |
2206 | |
2207 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2208 | ||
2209 | type = DNS_TYPE_DS; | |
2210 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2211 | t->id, dns_resource_key_name(t->key)); | |
2212 | ||
2213 | } else { | |
2214 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2215 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2216 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2217 | } |
105e1512 LP |
2218 | |
2219 | if (name) { | |
2220 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2221 | ||
4bbc06cc | 2222 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2223 | if (!soa) |
2224 | return -ENOMEM; | |
2225 | ||
2226 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2227 | if (r < 0) | |
2228 | return r; | |
2229 | } | |
2230 | } | |
2231 | ||
2232 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2233 | } |
2234 | ||
2235 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2236 | assert(t); |
547973de LP |
2237 | assert(source); |
2238 | ||
942eb2e7 LP |
2239 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2240 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2241 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2242 | |
942eb2e7 LP |
2243 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2244 | dns_transaction_process_dnssec(t); | |
547973de LP |
2245 | } |
2246 | ||
105e1512 LP |
2247 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2248 | DnsResourceRecord *rr; | |
2249 | int ifindex, r; | |
2250 | ||
2251 | assert(t); | |
2252 | ||
2253 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2254 | * RRs from the list of validated keys to the list of | |
2255 | * validated keys. */ | |
2256 | ||
2257 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2258 | ||
96bb7673 | 2259 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2260 | if (r < 0) |
2261 | return r; | |
2262 | if (r == 0) | |
2263 | continue; | |
2264 | ||
2265 | /* If so, the DNSKEY is validated too. */ | |
2266 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2267 | if (r < 0) | |
2268 | return r; | |
2269 | } | |
2270 | ||
2271 | return 0; | |
2272 | } | |
2273 | ||
2274 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2275 | int r; |
2276 | ||
2277 | assert(t); | |
2278 | assert(rr); | |
2279 | ||
105e1512 LP |
2280 | /* Checks if the RR we are looking for must be signed with an |
2281 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2282 | |
b652d4a2 | 2283 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2284 | return false; |
56352fe9 | 2285 | |
105e1512 LP |
2286 | if (dns_type_is_pseudo(rr->key->type)) |
2287 | return -EINVAL; | |
56352fe9 | 2288 | |
1c02e7ba | 2289 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2290 | if (r < 0) |
2291 | return r; | |
2292 | if (r > 0) | |
2293 | return false; | |
2294 | ||
105e1512 | 2295 | switch (rr->key->type) { |
56352fe9 | 2296 | |
105e1512 LP |
2297 | case DNS_TYPE_RRSIG: |
2298 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2299 | return false; | |
2300 | ||
2301 | case DNS_TYPE_SOA: | |
2302 | case DNS_TYPE_NS: { | |
2303 | DnsTransaction *dt; | |
2304 | Iterator i; | |
2305 | ||
b63fca62 | 2306 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2307 | |
2308 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2309 | ||
2310 | if (dt->key->class != rr->key->class) | |
2311 | continue; | |
2312 | if (dt->key->type != DNS_TYPE_DS) | |
2313 | continue; | |
2314 | ||
1c02e7ba | 2315 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2316 | if (r < 0) |
2317 | return r; | |
2318 | if (r == 0) | |
2319 | continue; | |
2320 | ||
2321 | /* We found a DS transactions for the SOA/NS | |
2322 | * RRs we are looking at. If it discovered signed DS | |
2323 | * RRs, then we need to be signed, too. */ | |
2324 | ||
097a2517 TA |
2325 | if (!dt->answer_authenticated) |
2326 | return false; | |
105e1512 | 2327 | |
097a2517 | 2328 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2329 | } |
2330 | ||
2331 | /* We found nothing that proves this is safe to leave | |
2332 | * this unauthenticated, hence ask inist on | |
2333 | * authentication. */ | |
2334 | return true; | |
2335 | } | |
2336 | ||
b63fca62 | 2337 | case DNS_TYPE_DS: |
105e1512 LP |
2338 | case DNS_TYPE_CNAME: |
2339 | case DNS_TYPE_DNAME: { | |
2340 | const char *parent = NULL; | |
2341 | DnsTransaction *dt; | |
2342 | Iterator i; | |
2343 | ||
b63fca62 LP |
2344 | /* |
2345 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2346 | * | |
2347 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2348 | */ | |
105e1512 LP |
2349 | |
2350 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2351 | ||
2352 | if (dt->key->class != rr->key->class) | |
2353 | continue; | |
2354 | if (dt->key->type != DNS_TYPE_SOA) | |
2355 | continue; | |
2356 | ||
2357 | if (!parent) { | |
1c02e7ba | 2358 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2359 | r = dns_name_parent(&parent); |
2360 | if (r < 0) | |
2361 | return r; | |
2362 | if (r == 0) { | |
b63fca62 LP |
2363 | if (rr->key->type == DNS_TYPE_DS) |
2364 | return true; | |
2365 | ||
105e1512 LP |
2366 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2367 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2368 | return -EBADMSG; | |
2369 | } | |
2370 | } | |
2371 | ||
1c02e7ba | 2372 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2373 | if (r < 0) |
2374 | return r; | |
2375 | if (r == 0) | |
2376 | continue; | |
2377 | ||
2378 | return t->answer_authenticated; | |
2379 | } | |
2380 | ||
2381 | return true; | |
2382 | } | |
2383 | ||
2384 | default: { | |
2385 | DnsTransaction *dt; | |
2386 | Iterator i; | |
2387 | ||
b63fca62 | 2388 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2389 | |
2390 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2391 | ||
2392 | if (dt->key->class != rr->key->class) | |
2393 | continue; | |
2394 | if (dt->key->type != DNS_TYPE_SOA) | |
2395 | continue; | |
2396 | ||
1c02e7ba | 2397 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2398 | if (r < 0) |
2399 | return r; | |
2400 | if (r == 0) | |
2401 | continue; | |
2402 | ||
2403 | /* We found the transaction that was supposed to find | |
2404 | * the SOA RR for us. It was successful, but found no | |
2405 | * RR for us. This means we are not at a zone cut. In | |
2406 | * this case, we require authentication if the SOA | |
2407 | * lookup was authenticated too. */ | |
2408 | return t->answer_authenticated; | |
2409 | } | |
2410 | ||
2411 | return true; | |
2412 | }} | |
56352fe9 LP |
2413 | } |
2414 | ||
d33b6cf3 LP |
2415 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2416 | DnsTransaction *dt; | |
2417 | const char *tld; | |
2418 | Iterator i; | |
2419 | int r; | |
2420 | ||
2421 | /* If DNSSEC downgrade mode is on, checks whether the | |
2422 | * specified RR is one level below a TLD we have proven not to | |
2423 | * exist. In such a case we assume that this is a private | |
2424 | * domain, and permit it. | |
2425 | * | |
2426 | * This detects cases like the Fritz!Box router networks. Each | |
2427 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2428 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2429 | * are served by the router itself, while requests for the | |
2430 | * "box" domain will result in NXDOMAIN. | |
2431 | * | |
2432 | * Note that this logic is unable to detect cases where a | |
2433 | * router serves a private DNS zone directly under | |
2434 | * non-existing TLD. In such a case we cannot detect whether | |
2435 | * the TLD is supposed to exist or not, as all requests we | |
2436 | * make for it will be answered by the router's zone, and not | |
2437 | * by the root zone. */ | |
2438 | ||
2439 | assert(t); | |
2440 | ||
2441 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2442 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2443 | ||
1c02e7ba | 2444 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2445 | r = dns_name_parent(&tld); |
2446 | if (r < 0) | |
2447 | return r; | |
2448 | if (r == 0) | |
2449 | return false; /* Already the root domain */ | |
2450 | ||
2451 | if (!dns_name_is_single_label(tld)) | |
2452 | return false; | |
2453 | ||
2454 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2455 | ||
2456 | if (dt->key->class != key->class) | |
2457 | continue; | |
2458 | ||
1c02e7ba | 2459 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2460 | if (r < 0) |
2461 | return r; | |
2462 | if (r == 0) | |
2463 | continue; | |
2464 | ||
2465 | /* We found an auxiliary lookup we did for the TLD. If | |
2466 | * that returned with NXDOMAIN, we know the TLD didn't | |
2467 | * exist, and hence this might be a private zone. */ | |
2468 | ||
2469 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2470 | } | |
2471 | ||
2472 | return false; | |
2473 | } | |
2474 | ||
105e1512 | 2475 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2476 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2477 | DnsTransaction *dt; |
2478 | const char *name; | |
4bbc06cc | 2479 | uint16_t type = 0; |
105e1512 LP |
2480 | Iterator i; |
2481 | int r; | |
56352fe9 LP |
2482 | |
2483 | assert(t); | |
2484 | ||
105e1512 LP |
2485 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2486 | * this negative reply */ | |
56352fe9 | 2487 | |
b652d4a2 | 2488 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2489 | return false; |
56352fe9 | 2490 | |
105e1512 LP |
2491 | if (dns_type_is_pseudo(t->key->type)) |
2492 | return -EINVAL; | |
2493 | ||
1c02e7ba | 2494 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2495 | if (r < 0) |
2496 | return r; | |
2497 | if (r > 0) | |
2498 | return false; | |
2499 | ||
d33b6cf3 LP |
2500 | r = dns_transaction_in_private_tld(t, t->key); |
2501 | if (r < 0) | |
2502 | return r; | |
2503 | if (r > 0) { | |
2504 | /* The lookup is from a TLD that is proven not to | |
2505 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2506 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2507 | |
202b76ae ZJS |
2508 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2509 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2510 | return false; |
2511 | } | |
2512 | ||
1c02e7ba | 2513 | name = dns_resource_key_name(t->key); |
105e1512 | 2514 | |
4bbc06cc | 2515 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2516 | |
4bbc06cc LP |
2517 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2518 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2519 | |
2520 | r = dns_name_parent(&name); | |
56352fe9 LP |
2521 | if (r < 0) |
2522 | return r; | |
2523 | if (r == 0) | |
105e1512 | 2524 | return true; |
4bbc06cc LP |
2525 | |
2526 | type = DNS_TYPE_SOA; | |
2527 | ||
2528 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2529 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2530 | type = DNS_TYPE_DS; | |
2531 | else | |
2532 | /* For all other negative replies, check for the SOA lookup */ | |
2533 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2534 | |
2535 | /* For all other RRs we check the SOA on the same level to see | |
2536 | * if it's signed. */ | |
2537 | ||
2538 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2539 | ||
2540 | if (dt->key->class != t->key->class) | |
2541 | continue; | |
4bbc06cc | 2542 | if (dt->key->type != type) |
56352fe9 LP |
2543 | continue; |
2544 | ||
1c02e7ba | 2545 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2546 | if (r < 0) |
2547 | return r; | |
105e1512 LP |
2548 | if (r == 0) |
2549 | continue; | |
2550 | ||
2551 | return dt->answer_authenticated; | |
56352fe9 LP |
2552 | } |
2553 | ||
105e1512 LP |
2554 | /* If in doubt, require NSEC/NSEC3 */ |
2555 | return true; | |
56352fe9 LP |
2556 | } |
2557 | ||
94aa7071 LP |
2558 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2559 | DnsResourceRecord *rrsig; | |
2560 | bool found = false; | |
2561 | int r; | |
2562 | ||
2563 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2564 | * the specified RRset is authenticated (i.e. has a matching | |
2565 | * DS RR). */ | |
2566 | ||
1c02e7ba | 2567 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2568 | if (r < 0) |
2569 | return r; | |
2570 | if (r > 0) | |
2571 | return false; | |
2572 | ||
94aa7071 LP |
2573 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2574 | DnsTransaction *dt; | |
2575 | Iterator i; | |
2576 | ||
2577 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2578 | if (r < 0) | |
2579 | return r; | |
2580 | if (r == 0) | |
2581 | continue; | |
2582 | ||
2583 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2584 | ||
2585 | if (dt->key->class != rr->key->class) | |
2586 | continue; | |
2587 | ||
2588 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2589 | ||
1c02e7ba | 2590 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2591 | if (r < 0) |
2592 | return r; | |
2593 | if (r == 0) | |
2594 | continue; | |
2595 | ||
2596 | /* OK, we found an auxiliary DNSKEY | |
2597 | * lookup. If that lookup is | |
2598 | * authenticated, report this. */ | |
2599 | ||
2600 | if (dt->answer_authenticated) | |
2601 | return true; | |
2602 | ||
2603 | found = true; | |
2604 | ||
2605 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2606 | ||
1c02e7ba | 2607 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2608 | if (r < 0) |
2609 | return r; | |
2610 | if (r == 0) | |
2611 | continue; | |
2612 | ||
2613 | /* OK, we found an auxiliary DS | |
2614 | * lookup. If that lookup is | |
2615 | * authenticated and non-zero, we | |
2616 | * won! */ | |
2617 | ||
2618 | if (!dt->answer_authenticated) | |
2619 | return false; | |
2620 | ||
2621 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2622 | } | |
2623 | } | |
2624 | } | |
2625 | ||
2626 | return found ? false : -ENXIO; | |
2627 | } | |
2628 | ||
b652d4a2 LP |
2629 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2630 | assert(t); | |
2631 | assert(rr); | |
2632 | ||
2633 | /* We know that the root domain is signed, hence if it appears | |
2634 | * not to be signed, there's a problem with the DNS server */ | |
2635 | ||
2636 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2637 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2638 | } |
2639 | ||
0f87f3e8 LP |
2640 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2641 | DnsResourceRecord *rr; | |
2642 | int r; | |
2643 | ||
2644 | assert(t); | |
2645 | ||
2646 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2647 | * for a key from our trust anchor. Note that we don't care | |
2648 | * whether the DNSKEY can be authenticated or not. It's | |
2649 | * sufficient if it is self-signed. */ | |
2650 | ||
2651 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2652 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2653 | if (r < 0) |
2654 | return r; | |
2655 | } | |
2656 | ||
2657 | return 0; | |
2658 | } | |
2659 | ||
c9c72065 LP |
2660 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2661 | bool changed; | |
2662 | int r; | |
2663 | ||
2664 | assert(t); | |
2665 | ||
2666 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2667 | * our trust anchors database considers revoked. */ | |
2668 | ||
2669 | do { | |
2670 | DnsResourceRecord *rr; | |
2671 | ||
2672 | changed = false; | |
2673 | ||
2674 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2675 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2676 | if (r < 0) | |
2677 | return r; | |
2678 | if (r > 0) { | |
2679 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2680 | if (r < 0) | |
2681 | return r; | |
2682 | ||
2683 | assert(r > 0); | |
2684 | changed = true; | |
2685 | break; | |
2686 | } | |
2687 | } | |
2688 | } while (changed); | |
2689 | ||
2690 | return 0; | |
2691 | } | |
2692 | ||
942eb2e7 LP |
2693 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2694 | DnsTransaction *dt; | |
2695 | Iterator i; | |
2696 | int r; | |
2697 | ||
2698 | assert(t); | |
2699 | ||
2700 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2701 | ||
2702 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2703 | ||
2704 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2705 | continue; | |
2706 | ||
2707 | if (!dt->answer_authenticated) | |
2708 | continue; | |
2709 | ||
2710 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2711 | if (r < 0) | |
2712 | return r; | |
2713 | } | |
2714 | ||
2715 | return 0; | |
2716 | } | |
2717 | ||
c690b20a ZJS |
2718 | typedef enum { |
2719 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2720 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2721 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2722 | } Phase; | |
2723 | ||
2724 | static int dnssec_validate_records( | |
2725 | DnsTransaction *t, | |
2726 | Phase phase, | |
2727 | bool *have_nsec, | |
2728 | DnsAnswer **validated) { | |
2729 | ||
547973de | 2730 | DnsResourceRecord *rr; |
56352fe9 | 2731 | int r; |
547973de | 2732 | |
c690b20a | 2733 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2734 | |
c690b20a ZJS |
2735 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2736 | DnsResourceRecord *rrsig = NULL; | |
2737 | DnssecResult result; | |
547973de | 2738 | |
c690b20a ZJS |
2739 | switch (rr->key->type) { |
2740 | case DNS_TYPE_RRSIG: | |
2741 | continue; | |
547973de | 2742 | |
c690b20a ZJS |
2743 | case DNS_TYPE_DNSKEY: |
2744 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2745 | if (phase == DNSSEC_PHASE_NSEC) | |
2746 | continue; | |
2747 | break; | |
547973de | 2748 | |
c690b20a ZJS |
2749 | case DNS_TYPE_NSEC: |
2750 | case DNS_TYPE_NSEC3: | |
2751 | *have_nsec = true; | |
547973de | 2752 | |
c690b20a ZJS |
2753 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2754 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2755 | continue; | |
2756 | break; | |
105e1512 | 2757 | |
c690b20a ZJS |
2758 | default: |
2759 | /* We validate all other RRs only in the ALL phases */ | |
2760 | if (phase != DNSSEC_PHASE_ALL) | |
2761 | continue; | |
2762 | } | |
b652d4a2 | 2763 | |
c690b20a ZJS |
2764 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2765 | if (r < 0) | |
2766 | return r; | |
547973de | 2767 | |
c690b20a | 2768 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2769 | |
c690b20a | 2770 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2771 | |
c690b20a ZJS |
2772 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2773 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2774 | * the set of validated keys for this transaction. */ | |
547973de | 2775 | |
c690b20a ZJS |
2776 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2777 | if (r < 0) | |
2778 | return r; | |
c9c72065 | 2779 | |
c690b20a ZJS |
2780 | /* Some of the DNSKEYs we just added might already have been revoked, |
2781 | * remove them again in that case. */ | |
2782 | r = dns_transaction_invalidate_revoked_keys(t); | |
2783 | if (r < 0) | |
2784 | return r; | |
2785 | } | |
547973de | 2786 | |
c690b20a ZJS |
2787 | /* Add the validated RRset to the new list of validated |
2788 | * RRsets, and remove it from the unvalidated RRsets. | |
2789 | * We mark the RRset as authenticated and cacheable. */ | |
2790 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2791 | if (r < 0) | |
2792 | return r; | |
547973de | 2793 | |
c690b20a | 2794 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2795 | |
c690b20a ZJS |
2796 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2797 | return 1; | |
2798 | } | |
547973de | 2799 | |
c690b20a ZJS |
2800 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2801 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2802 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2803 | if (phase != DNSSEC_PHASE_ALL) | |
2804 | continue; | |
0c7bff0a | 2805 | |
c690b20a ZJS |
2806 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2807 | bool authenticated = false; | |
2808 | const char *source; | |
0c7bff0a | 2809 | |
c690b20a | 2810 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 2811 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 2812 | |
c690b20a ZJS |
2813 | /* First step, determine the source of synthesis */ |
2814 | r = dns_resource_record_source(rrsig, &source); | |
2815 | if (r < 0) | |
2816 | return r; | |
0c7bff0a | 2817 | |
c690b20a | 2818 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2819 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2820 | source, |
2821 | rrsig->rrsig.signer, | |
2822 | &authenticated); | |
0c7bff0a | 2823 | |
c690b20a ZJS |
2824 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2825 | if (r == 0) | |
2826 | result = DNSSEC_INVALID; | |
2827 | else { | |
2828 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2829 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2830 | if (r < 0) | |
2831 | return r; | |
2832 | ||
2833 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2834 | ||
2835 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2836 | return 1; | |
0c7bff0a | 2837 | } |
c690b20a | 2838 | } |
0c7bff0a | 2839 | |
c690b20a ZJS |
2840 | if (result == DNSSEC_NO_SIGNATURE) { |
2841 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2842 | if (r < 0) |
2843 | return r; | |
c690b20a ZJS |
2844 | if (r == 0) { |
2845 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 2846 | * but remember that this is by no means authenticated. */ |
c690b20a ZJS |
2847 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
2848 | if (r < 0) | |
2849 | return r; | |
2850 | ||
2851 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2852 | return 1; | |
2853 | } | |
547973de | 2854 | |
c690b20a ZJS |
2855 | r = dns_transaction_known_signed(t, rr); |
2856 | if (r < 0) | |
2857 | return r; | |
2858 | if (r > 0) { | |
2859 | /* This is an RR we know has to be signed. If it isn't this means | |
2860 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2861 | |
c690b20a | 2862 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2863 | |
c690b20a | 2864 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2865 | |
c690b20a | 2866 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2867 | |
c690b20a | 2868 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2869 | if (r < 0) |
2870 | return r; | |
547973de | 2871 | |
c690b20a ZJS |
2872 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2873 | return 1; | |
2874 | } | |
a150ff5e | 2875 | |
c690b20a ZJS |
2876 | /* Otherwise, fail */ |
2877 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2878 | return 0; | |
f3cf586d | 2879 | } |
547973de | 2880 | |
c690b20a ZJS |
2881 | r = dns_transaction_in_private_tld(t, rr->key); |
2882 | if (r < 0) | |
2883 | return r; | |
2884 | if (r > 0) { | |
202b76ae | 2885 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 2886 | |
c690b20a ZJS |
2887 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
2888 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 2889 | |
202b76ae ZJS |
2890 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
2891 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 2892 | |
c690b20a | 2893 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
2894 | if (r < 0) |
2895 | return r; | |
0c7bff0a | 2896 | |
c690b20a ZJS |
2897 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2898 | return 1; | |
2899 | } | |
2900 | } | |
0c7bff0a | 2901 | |
c690b20a ZJS |
2902 | if (IN_SET(result, |
2903 | DNSSEC_MISSING_KEY, | |
2904 | DNSSEC_SIGNATURE_EXPIRED, | |
2905 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 2906 | |
c690b20a ZJS |
2907 | r = dns_transaction_dnskey_authenticated(t, rr); |
2908 | if (r < 0 && r != -ENXIO) | |
2909 | return r; | |
2910 | if (r == 0) { | |
2911 | /* The DNSKEY transaction was not authenticated, this means there's | |
2912 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 2913 | |
c690b20a | 2914 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
2915 | if (r < 0) |
2916 | return r; | |
b652d4a2 | 2917 | |
c690b20a ZJS |
2918 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2919 | return 1; | |
2920 | } | |
2921 | } | |
b652d4a2 | 2922 | |
c690b20a ZJS |
2923 | r = dns_transaction_is_primary_response(t, rr); |
2924 | if (r < 0) | |
2925 | return r; | |
2926 | if (r > 0) { | |
2927 | /* Look for a matching DNAME for this CNAME */ | |
2928 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
2929 | if (r < 0) | |
2930 | return r; | |
2931 | if (r == 0) { | |
2932 | /* Also look among the stuff we already validated */ | |
2933 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
2934 | if (r < 0) |
2935 | return r; | |
c690b20a | 2936 | } |
d33b6cf3 | 2937 | |
c690b20a ZJS |
2938 | if (r == 0) { |
2939 | if (IN_SET(result, | |
2940 | DNSSEC_INVALID, | |
2941 | DNSSEC_SIGNATURE_EXPIRED, | |
2942 | DNSSEC_NO_SIGNATURE)) | |
2943 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
2944 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
2945 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
2946 | ||
2947 | /* This is a primary response to our question, and it failed validation. | |
2948 | * That's fatal. */ | |
2949 | t->answer_dnssec_result = result; | |
2950 | return 0; | |
2951 | } | |
d33b6cf3 | 2952 | |
c690b20a ZJS |
2953 | /* This is a primary response, but we do have a DNAME RR |
2954 | * in the RR that can replay this CNAME, hence rely on | |
2955 | * that, and we can remove the CNAME in favour of it. */ | |
2956 | } | |
d33b6cf3 | 2957 | |
c690b20a ZJS |
2958 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
2959 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
2960 | if (r < 0) | |
2961 | return r; | |
d33b6cf3 | 2962 | |
c690b20a ZJS |
2963 | /* We dropped something from the answer, start from the beginning. */ |
2964 | return 1; | |
2965 | } | |
f3cf586d | 2966 | |
c690b20a ZJS |
2967 | return 2; /* Finito. */ |
2968 | } | |
94aa7071 | 2969 | |
c690b20a ZJS |
2970 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
2971 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
2972 | Phase phase; | |
2973 | DnsAnswerFlags flags; | |
2974 | int r; | |
202b76ae | 2975 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 2976 | |
c690b20a | 2977 | assert(t); |
94aa7071 | 2978 | |
c690b20a ZJS |
2979 | /* We have now collected all DS and DNSKEY RRs in |
2980 | * t->validated_keys, let's see which RRs we can now | |
2981 | * authenticate with that. */ | |
94aa7071 | 2982 | |
c690b20a ZJS |
2983 | if (t->scope->dnssec_mode == DNSSEC_NO) |
2984 | return 0; | |
a150ff5e | 2985 | |
c690b20a ZJS |
2986 | /* Already validated */ |
2987 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
2988 | return 0; | |
105e1512 | 2989 | |
c690b20a ZJS |
2990 | /* Our own stuff needs no validation */ |
2991 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
2992 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
2993 | t->answer_authenticated = true; | |
2994 | return 0; | |
2995 | } | |
a150ff5e | 2996 | |
c690b20a ZJS |
2997 | /* Cached stuff is not affected by validation. */ |
2998 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
2999 | return 0; | |
f3cf586d | 3000 | |
c690b20a ZJS |
3001 | if (!dns_transaction_dnssec_supported_full(t)) { |
3002 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3003 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3004 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3005 | return 0; |
3006 | } | |
f3cf586d | 3007 | |
202b76ae ZJS |
3008 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3009 | t->id, | |
3010 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 3011 | |
c690b20a ZJS |
3012 | /* First, see if this response contains any revoked trust |
3013 | * anchors we care about */ | |
3014 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3015 | if (r < 0) | |
3016 | return r; | |
43e6779a | 3017 | |
c690b20a ZJS |
3018 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3019 | r = dns_transaction_copy_validated(t); | |
3020 | if (r < 0) | |
3021 | return r; | |
43e6779a | 3022 | |
c690b20a ZJS |
3023 | /* Second, see if there are DNSKEYs we already know a |
3024 | * validated DS for. */ | |
3025 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3026 | if (r < 0) | |
3027 | return r; | |
43e6779a | 3028 | |
c690b20a ZJS |
3029 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3030 | * anchor says are revoked. After all we might have marked | |
3031 | * some keys revoked above, but they might still be lingering | |
3032 | * in our validated_keys list. */ | |
3033 | r = dns_transaction_invalidate_revoked_keys(t); | |
3034 | if (r < 0) | |
3035 | return r; | |
f3cf586d | 3036 | |
c690b20a ZJS |
3037 | phase = DNSSEC_PHASE_DNSKEY; |
3038 | for (;;) { | |
3039 | bool have_nsec = false; | |
f3cf586d | 3040 | |
c690b20a ZJS |
3041 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3042 | if (r <= 0) | |
3043 | return r; | |
547973de | 3044 | |
c690b20a ZJS |
3045 | /* Try again as long as we managed to achieve something */ |
3046 | if (r == 1) | |
547973de LP |
3047 | continue; |
3048 | ||
c690b20a | 3049 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3050 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3051 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3052 | continue; |
3053 | } | |
3054 | ||
c690b20a ZJS |
3055 | if (phase != DNSSEC_PHASE_ALL) { |
3056 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3057 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3058 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3059 | continue; |
547973de LP |
3060 | } |
3061 | ||
56352fe9 | 3062 | /* We're done */ |
547973de LP |
3063 | break; |
3064 | } | |
3065 | ||
3066 | dns_answer_unref(t->answer); | |
1cc6c93a | 3067 | t->answer = TAKE_PTR(validated); |
547973de | 3068 | |
72667f08 LP |
3069 | /* At this point the answer only contains validated |
3070 | * RRsets. Now, let's see if it actually answers the question | |
3071 | * we asked. If so, great! If it doesn't, then see if | |
3072 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3073 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3074 | if (r > 0) { |
105e1512 LP |
3075 | /* Yes, it answers the question! */ |
3076 | ||
3077 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3078 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3079 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3080 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3081 | t->answer_authenticated = true; | |
3082 | } else { | |
3083 | /* The answer is not fully authenticated. */ | |
019036a4 | 3084 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3085 | t->answer_authenticated = false; |
3086 | } | |
3087 | ||
72667f08 LP |
3088 | } else if (r == 0) { |
3089 | DnssecNsecResult nr; | |
ed29bfdc | 3090 | bool authenticated = false; |
72667f08 LP |
3091 | |
3092 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3093 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3094 | if (r < 0) |
3095 | return r; | |
3096 | ||
3097 | switch (nr) { | |
3098 | ||
3099 | case DNSSEC_NSEC_NXDOMAIN: | |
3100 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3101 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3102 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3103 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3104 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3105 | |
59c5b597 | 3106 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3107 | break; |
3108 | ||
3109 | case DNSSEC_NSEC_NODATA: | |
3110 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3111 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3112 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3113 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3114 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3115 | |
59c5b597 | 3116 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3117 | break; |
3118 | ||
105e1512 LP |
3119 | case DNSSEC_NSEC_OPTOUT: |
3120 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3121 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3122 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3123 | t->answer_authenticated = false; |
7aa8ce98 | 3124 | |
59c5b597 | 3125 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3126 | break; |
3127 | ||
72667f08 LP |
3128 | case DNSSEC_NSEC_NO_RR: |
3129 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3130 | |
3131 | r = dns_transaction_requires_nsec(t); | |
3132 | if (r < 0) | |
3133 | return r; | |
7aa8ce98 | 3134 | if (r > 0) { |
019036a4 | 3135 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3136 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3137 | } else { |
019036a4 | 3138 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3139 | t->answer_authenticated = false; |
59c5b597 | 3140 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3141 | } |
3142 | ||
3143 | break; | |
3144 | ||
3145 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3146 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3147 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3148 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3149 | break; |
3150 | ||
3151 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3152 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3153 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3154 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3155 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3156 | break; |
3157 | ||
3158 | default: | |
3159 | assert_not_reached("Unexpected NSEC result."); | |
3160 | } | |
3161 | } | |
3162 | ||
547973de LP |
3163 | return 1; |
3164 | } | |
3165 | ||
ec2c5e43 LP |
3166 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3167 | [DNS_TRANSACTION_NULL] = "null", | |
3168 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3169 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3170 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3171 | [DNS_TRANSACTION_SUCCESS] = "success", |
3172 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3173 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3174 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3175 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3176 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3177 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3178 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3179 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3180 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3181 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3182 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3183 | }; |
3184 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3185 | |
3186 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3187 | [DNS_TRANSACTION_NETWORK] = "network", | |
3188 | [DNS_TRANSACTION_CACHE] = "cache", | |
3189 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3190 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3191 | }; |
3192 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |