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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 | |
5d67a7ae IT |
21 | #if HAVE_GNUTLS |
22 | #include <gnutls/socket.h> | |
23 | #endif | |
24 | ||
b214dc0f | 25 | #define TRANSACTIONS_MAX 4096 |
dc349f5f | 26 | #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC) |
b214dc0f | 27 | |
c61d2b44 LP |
28 | static void dns_transaction_reset_answer(DnsTransaction *t) { |
29 | assert(t); | |
30 | ||
31 | t->received = dns_packet_unref(t->received); | |
32 | t->answer = dns_answer_unref(t->answer); | |
33 | t->answer_rcode = 0; | |
34 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; | |
35 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; | |
36 | t->answer_authenticated = false; | |
d3760be0 | 37 | t->answer_nsec_ttl = (uint32_t) -1; |
7cc6ed7b | 38 | t->answer_errno = 0; |
c61d2b44 LP |
39 | } |
40 | ||
c5b4f861 LP |
41 | static void dns_transaction_flush_dnssec_transactions(DnsTransaction *t) { |
42 | DnsTransaction *z; | |
43 | ||
44 | assert(t); | |
45 | ||
46 | while ((z = set_steal_first(t->dnssec_transactions))) { | |
47 | set_remove(z->notify_transactions, t); | |
35aa04e9 | 48 | set_remove(z->notify_transactions_done, t); |
c5b4f861 LP |
49 | dns_transaction_gc(z); |
50 | } | |
51 | } | |
52 | ||
f32f0e57 LP |
53 | static void dns_transaction_close_connection(DnsTransaction *t) { |
54 | assert(t); | |
55 | ||
b30bf55d LP |
56 | if (t->stream) { |
57 | /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */ | |
98767d75 IT |
58 | LIST_REMOVE(transactions_by_stream, t->stream->transactions, t); |
59 | ||
60 | /* Remove packet in case it's still in the queue */ | |
61 | dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent)); | |
62 | ||
b30bf55d LP |
63 | t->stream = dns_stream_unref(t->stream); |
64 | } | |
65 | ||
f32f0e57 LP |
66 | t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source); |
67 | t->dns_udp_fd = safe_close(t->dns_udp_fd); | |
68 | } | |
69 | ||
f535705a | 70 | static void dns_transaction_stop_timeout(DnsTransaction *t) { |
97cc656c LP |
71 | assert(t); |
72 | ||
73 | t->timeout_event_source = sd_event_source_unref(t->timeout_event_source); | |
97cc656c LP |
74 | } |
75 | ||
ec2c5e43 | 76 | DnsTransaction* dns_transaction_free(DnsTransaction *t) { |
801ad6a6 | 77 | DnsQueryCandidate *c; |
ec2c5e43 | 78 | DnsZoneItem *i; |
547973de | 79 | DnsTransaction *z; |
ec2c5e43 LP |
80 | |
81 | if (!t) | |
82 | return NULL; | |
83 | ||
51e399bc LP |
84 | log_debug("Freeing transaction %" PRIu16 ".", t->id); |
85 | ||
f32f0e57 | 86 | dns_transaction_close_connection(t); |
f535705a | 87 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 88 | |
ec2c5e43 | 89 | dns_packet_unref(t->sent); |
c61d2b44 | 90 | dns_transaction_reset_answer(t); |
ec2c5e43 | 91 | |
8300ba21 | 92 | dns_server_unref(t->server); |
ec2c5e43 LP |
93 | |
94 | if (t->scope) { | |
f9ebb22a LP |
95 | hashmap_remove_value(t->scope->transactions_by_key, t->key, t); |
96 | LIST_REMOVE(transactions_by_scope, t->scope->transactions, t); | |
ec2c5e43 LP |
97 | |
98 | if (t->id != 0) | |
99 | hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
100 | } | |
101 | ||
547973de | 102 | while ((c = set_steal_first(t->notify_query_candidates))) |
801ad6a6 | 103 | set_remove(c->transactions, t); |
547973de | 104 | set_free(t->notify_query_candidates); |
801ad6a6 | 105 | |
35aa04e9 LP |
106 | while ((c = set_steal_first(t->notify_query_candidates_done))) |
107 | set_remove(c->transactions, t); | |
108 | set_free(t->notify_query_candidates_done); | |
109 | ||
547973de | 110 | while ((i = set_steal_first(t->notify_zone_items))) |
ec2c5e43 | 111 | i->probe_transaction = NULL; |
547973de LP |
112 | set_free(t->notify_zone_items); |
113 | ||
35aa04e9 LP |
114 | while ((i = set_steal_first(t->notify_zone_items_done))) |
115 | i->probe_transaction = NULL; | |
116 | set_free(t->notify_zone_items_done); | |
117 | ||
547973de LP |
118 | while ((z = set_steal_first(t->notify_transactions))) |
119 | set_remove(z->dnssec_transactions, t); | |
120 | set_free(t->notify_transactions); | |
121 | ||
35aa04e9 LP |
122 | while ((z = set_steal_first(t->notify_transactions_done))) |
123 | set_remove(z->dnssec_transactions, t); | |
124 | set_free(t->notify_transactions_done); | |
125 | ||
c5b4f861 | 126 | dns_transaction_flush_dnssec_transactions(t); |
547973de LP |
127 | set_free(t->dnssec_transactions); |
128 | ||
129 | dns_answer_unref(t->validated_keys); | |
97cc656c | 130 | dns_resource_key_unref(t->key); |
97cc656c | 131 | |
6b430fdb | 132 | return mfree(t); |
ec2c5e43 LP |
133 | } |
134 | ||
135 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_free); | |
136 | ||
51e399bc | 137 | bool dns_transaction_gc(DnsTransaction *t) { |
ec2c5e43 LP |
138 | assert(t); |
139 | ||
140 | if (t->block_gc > 0) | |
51e399bc | 141 | return true; |
ec2c5e43 | 142 | |
547973de | 143 | if (set_isempty(t->notify_query_candidates) && |
35aa04e9 | 144 | set_isempty(t->notify_query_candidates_done) && |
547973de | 145 | set_isempty(t->notify_zone_items) && |
35aa04e9 LP |
146 | set_isempty(t->notify_zone_items_done) && |
147 | set_isempty(t->notify_transactions) && | |
148 | set_isempty(t->notify_transactions_done)) { | |
ec2c5e43 | 149 | dns_transaction_free(t); |
51e399bc LP |
150 | return false; |
151 | } | |
152 | ||
153 | return true; | |
ec2c5e43 LP |
154 | } |
155 | ||
4dd15077 LP |
156 | static uint16_t pick_new_id(Manager *m) { |
157 | uint16_t new_id; | |
158 | ||
159 | /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of | |
160 | * transactions, and it's much lower than the space of IDs. */ | |
161 | ||
162 | assert_cc(TRANSACTIONS_MAX < 0xFFFF); | |
163 | ||
164 | do | |
165 | random_bytes(&new_id, sizeof(new_id)); | |
166 | while (new_id == 0 || | |
167 | hashmap_get(m->dns_transactions, UINT_TO_PTR(new_id))); | |
168 | ||
169 | return new_id; | |
170 | } | |
171 | ||
f52e61da | 172 | int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key) { |
ec2c5e43 LP |
173 | _cleanup_(dns_transaction_freep) DnsTransaction *t = NULL; |
174 | int r; | |
175 | ||
176 | assert(ret); | |
177 | assert(s); | |
f52e61da | 178 | assert(key); |
ec2c5e43 | 179 | |
9eae2bf3 | 180 | /* Don't allow looking up invalid or pseudo RRs */ |
c463eb78 | 181 | if (!dns_type_is_valid_query(key->type)) |
9eae2bf3 | 182 | return -EINVAL; |
d0129ddb LP |
183 | if (dns_type_is_obsolete(key->type)) |
184 | return -EOPNOTSUPP; | |
9eae2bf3 LP |
185 | |
186 | /* We only support the IN class */ | |
4c701096 | 187 | if (!IN_SET(key->class, DNS_CLASS_IN, DNS_CLASS_ANY)) |
9eae2bf3 LP |
188 | return -EOPNOTSUPP; |
189 | ||
b214dc0f LP |
190 | if (hashmap_size(s->manager->dns_transactions) >= TRANSACTIONS_MAX) |
191 | return -EBUSY; | |
192 | ||
d5099efc | 193 | r = hashmap_ensure_allocated(&s->manager->dns_transactions, NULL); |
ec2c5e43 LP |
194 | if (r < 0) |
195 | return r; | |
196 | ||
f9ebb22a | 197 | r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops); |
da0c630e LP |
198 | if (r < 0) |
199 | return r; | |
200 | ||
ec2c5e43 LP |
201 | t = new0(DnsTransaction, 1); |
202 | if (!t) | |
203 | return -ENOMEM; | |
204 | ||
4667e00a | 205 | t->dns_udp_fd = -1; |
c3bc53e6 | 206 | t->answer_source = _DNS_TRANSACTION_SOURCE_INVALID; |
019036a4 | 207 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
d3760be0 | 208 | t->answer_nsec_ttl = (uint32_t) -1; |
f52e61da | 209 | t->key = dns_resource_key_ref(key); |
274b8748 | 210 | t->current_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
d001e0a3 | 211 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; |
ec2c5e43 | 212 | |
4dd15077 | 213 | t->id = pick_new_id(s->manager); |
ec2c5e43 LP |
214 | |
215 | r = hashmap_put(s->manager->dns_transactions, UINT_TO_PTR(t->id), t); | |
216 | if (r < 0) { | |
217 | t->id = 0; | |
218 | return r; | |
219 | } | |
220 | ||
f9ebb22a | 221 | r = hashmap_replace(s->transactions_by_key, t->key, t); |
da0c630e LP |
222 | if (r < 0) { |
223 | hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id)); | |
224 | return r; | |
225 | } | |
226 | ||
f9ebb22a | 227 | LIST_PREPEND(transactions_by_scope, s->transactions, t); |
ec2c5e43 LP |
228 | t->scope = s; |
229 | ||
313cefa1 | 230 | s->manager->n_transactions_total++; |
a150ff5e | 231 | |
ec2c5e43 LP |
232 | if (ret) |
233 | *ret = t; | |
234 | ||
235 | t = NULL; | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
4dd15077 LP |
240 | static void dns_transaction_shuffle_id(DnsTransaction *t) { |
241 | uint16_t new_id; | |
242 | assert(t); | |
243 | ||
244 | /* Pick a new ID for this transaction. */ | |
245 | ||
246 | new_id = pick_new_id(t->scope->manager); | |
247 | assert_se(hashmap_remove_and_put(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id), UINT_TO_PTR(new_id), t) >= 0); | |
248 | ||
249 | log_debug("Transaction %" PRIu16 " is now %" PRIu16 ".", t->id, new_id); | |
250 | t->id = new_id; | |
251 | ||
252 | /* Make sure we generate a new packet with the new ID */ | |
253 | t->sent = dns_packet_unref(t->sent); | |
254 | } | |
255 | ||
ec2c5e43 | 256 | static void dns_transaction_tentative(DnsTransaction *t, DnsPacket *p) { |
2fb3034c | 257 | _cleanup_free_ char *pretty = NULL; |
202b76ae | 258 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 | 259 | DnsZoneItem *z; |
ec2c5e43 LP |
260 | |
261 | assert(t); | |
262 | assert(p); | |
263 | ||
264 | if (manager_our_packet(t->scope->manager, p) != 0) | |
265 | return; | |
266 | ||
164d025d | 267 | (void) in_addr_to_string(p->family, &p->sender, &pretty); |
2fb3034c | 268 | |
a5784c49 LP |
269 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s got tentative packet from %s.", |
270 | t->id, | |
202b76ae | 271 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
272 | dns_protocol_to_string(t->scope->protocol), |
273 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 274 | af_to_name_short(t->scope->family), |
164d025d | 275 | strnull(pretty)); |
ec2c5e43 | 276 | |
a4076574 LP |
277 | /* RFC 4795, Section 4.1 says that the peer with the |
278 | * lexicographically smaller IP address loses */ | |
4d91eec4 LP |
279 | if (memcmp(&p->sender, &p->destination, FAMILY_ADDRESS_SIZE(p->family)) >= 0) { |
280 | log_debug("Peer has lexicographically larger IP address and thus lost in the conflict."); | |
a4076574 LP |
281 | return; |
282 | } | |
283 | ||
4d91eec4 | 284 | log_debug("We have the lexicographically larger IP address and thus lost in the conflict."); |
a4076574 | 285 | |
ec2c5e43 | 286 | t->block_gc++; |
35aa04e9 | 287 | |
547973de | 288 | while ((z = set_first(t->notify_zone_items))) { |
3ef64445 LP |
289 | /* First, make sure the zone item drops the reference |
290 | * to us */ | |
291 | dns_zone_item_probe_stop(z); | |
292 | ||
293 | /* Secondly, report this as conflict, so that we might | |
294 | * look for a different hostname */ | |
ec2c5e43 | 295 | dns_zone_item_conflict(z); |
3ef64445 | 296 | } |
ec2c5e43 LP |
297 | t->block_gc--; |
298 | ||
299 | dns_transaction_gc(t); | |
300 | } | |
301 | ||
302 | void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) { | |
801ad6a6 | 303 | DnsQueryCandidate *c; |
ec2c5e43 | 304 | DnsZoneItem *z; |
547973de | 305 | DnsTransaction *d; |
7cc6ed7b | 306 | const char *st; |
202b76ae | 307 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
ec2c5e43 LP |
308 | |
309 | assert(t); | |
547973de | 310 | assert(!DNS_TRANSACTION_IS_LIVE(state)); |
e56187ca | 311 | |
202b76ae ZJS |
312 | if (state == DNS_TRANSACTION_DNSSEC_FAILED) { |
313 | dns_resource_key_to_string(t->key, key_str, sizeof key_str); | |
314 | ||
f61dfddb | 315 | log_struct(LOG_NOTICE, |
2b044526 | 316 | "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR, |
202b76ae | 317 | LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str, dnssec_result_to_string(t->answer_dnssec_result)), |
f61dfddb | 318 | "DNS_TRANSACTION=%" PRIu16, t->id, |
202b76ae | 319 | "DNS_QUESTION=%s", key_str, |
f61dfddb | 320 | "DNSSEC_RESULT=%s", dnssec_result_to_string(t->answer_dnssec_result), |
1e02e182 | 321 | "DNS_SERVER=%s", dns_server_string(t->server), |
a1230ff9 | 322 | "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t->server->possible_feature_level)); |
202b76ae | 323 | } |
f61dfddb | 324 | |
ec2c5e43 LP |
325 | /* Note that this call might invalidate the query. Callers |
326 | * should hence not attempt to access the query or transaction | |
327 | * after calling this function. */ | |
328 | ||
7cc6ed7b LP |
329 | if (state == DNS_TRANSACTION_ERRNO) |
330 | st = errno_to_name(t->answer_errno); | |
331 | else | |
332 | st = dns_transaction_state_to_string(state); | |
333 | ||
a5784c49 LP |
334 | log_debug("Transaction %" PRIu16 " for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).", |
335 | t->id, | |
202b76ae | 336 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
ec2c5e43 LP |
337 | dns_protocol_to_string(t->scope->protocol), |
338 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 339 | af_to_name_short(t->scope->family), |
7cc6ed7b | 340 | st, |
a5784c49 LP |
341 | t->answer_source < 0 ? "none" : dns_transaction_source_to_string(t->answer_source), |
342 | t->answer_authenticated ? "authenticated" : "unsigned"); | |
ec2c5e43 LP |
343 | |
344 | t->state = state; | |
345 | ||
f32f0e57 | 346 | dns_transaction_close_connection(t); |
f535705a | 347 | dns_transaction_stop_timeout(t); |
ec2c5e43 LP |
348 | |
349 | /* Notify all queries that are interested, but make sure the | |
350 | * transaction isn't freed while we are still looking at it */ | |
351 | t->block_gc++; | |
f7014757 | 352 | |
35aa04e9 | 353 | SET_FOREACH_MOVE(c, t->notify_query_candidates_done, t->notify_query_candidates) |
547973de | 354 | dns_query_candidate_notify(c); |
35aa04e9 | 355 | SWAP_TWO(t->notify_query_candidates, t->notify_query_candidates_done); |
ec2c5e43 | 356 | |
35aa04e9 LP |
357 | SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items) |
358 | dns_zone_item_notify(z); | |
359 | SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done); | |
8d67e72c | 360 | if (t->probing && t->state == DNS_TRANSACTION_ATTEMPTS_MAX_REACHED) |
1a63fc54 | 361 | (void) dns_scope_announce(t->scope, false); |
f7014757 | 362 | |
35aa04e9 LP |
363 | SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions) |
364 | dns_transaction_notify(d, t); | |
365 | SWAP_TWO(t->notify_transactions, t->notify_transactions_done); | |
f7014757 LP |
366 | |
367 | t->block_gc--; | |
ec2c5e43 LP |
368 | dns_transaction_gc(t); |
369 | } | |
370 | ||
519ef046 LP |
371 | static int dns_transaction_pick_server(DnsTransaction *t) { |
372 | DnsServer *server; | |
373 | ||
374 | assert(t); | |
375 | assert(t->scope->protocol == DNS_PROTOCOL_DNS); | |
376 | ||
d001e0a3 LP |
377 | /* Pick a DNS server and a feature level for it. */ |
378 | ||
519ef046 LP |
379 | server = dns_scope_get_dns_server(t->scope); |
380 | if (!server) | |
381 | return -ESRCH; | |
382 | ||
d001e0a3 LP |
383 | /* If we changed the server invalidate the feature level clamping, as the new server might have completely |
384 | * different properties. */ | |
385 | if (server != t->server) | |
386 | t->clamp_feature_level = _DNS_SERVER_FEATURE_LEVEL_INVALID; | |
387 | ||
274b8748 | 388 | t->current_feature_level = dns_server_possible_feature_level(server); |
519ef046 | 389 | |
d001e0a3 LP |
390 | /* Clamp the feature level if that is requested. */ |
391 | if (t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID && | |
392 | t->current_feature_level > t->clamp_feature_level) | |
393 | t->current_feature_level = t->clamp_feature_level; | |
394 | ||
395 | log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t->current_feature_level), t->id); | |
396 | ||
519ef046 LP |
397 | if (server == t->server) |
398 | return 0; | |
399 | ||
400 | dns_server_unref(t->server); | |
401 | t->server = dns_server_ref(server); | |
402 | ||
44db02d0 LP |
403 | t->n_picked_servers ++; |
404 | ||
d001e0a3 LP |
405 | log_debug("Using DNS server %s for transaction %u.", dns_server_string(t->server), t->id); |
406 | ||
519ef046 LP |
407 | return 1; |
408 | } | |
409 | ||
d001e0a3 | 410 | static void dns_transaction_retry(DnsTransaction *t, bool next_server) { |
8d10d620 LP |
411 | int r; |
412 | ||
413 | assert(t); | |
414 | ||
415 | log_debug("Retrying transaction %" PRIu16 ".", t->id); | |
416 | ||
417 | /* Before we try again, switch to a new server. */ | |
d001e0a3 LP |
418 | if (next_server) |
419 | dns_scope_next_dns_server(t->scope); | |
8d10d620 LP |
420 | |
421 | r = dns_transaction_go(t); | |
7cc6ed7b LP |
422 | if (r < 0) { |
423 | t->answer_errno = -r; | |
424 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
425 | } | |
8d10d620 LP |
426 | } |
427 | ||
c02cf2f4 | 428 | static int dns_transaction_maybe_restart(DnsTransaction *t) { |
5278bbfe LP |
429 | int r; |
430 | ||
c02cf2f4 LP |
431 | assert(t); |
432 | ||
5278bbfe LP |
433 | /* Returns > 0 if the transaction was restarted, 0 if not */ |
434 | ||
c02cf2f4 LP |
435 | if (!t->server) |
436 | return 0; | |
437 | ||
438 | if (t->current_feature_level <= dns_server_possible_feature_level(t->server)) | |
439 | return 0; | |
440 | ||
441 | /* The server's current feature level is lower than when we sent the original query. We learnt something from | |
442 | the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to | |
443 | restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include | |
444 | OPT RR or DO bit. One of these cases is documented here, for example: | |
445 | https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */ | |
446 | ||
4dd15077 LP |
447 | log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID."); |
448 | dns_transaction_shuffle_id(t); | |
5278bbfe LP |
449 | |
450 | r = dns_transaction_go(t); | |
451 | if (r < 0) | |
452 | return r; | |
453 | ||
454 | return 1; | |
c02cf2f4 LP |
455 | } |
456 | ||
98767d75 IT |
457 | static void on_transaction_stream_error(DnsTransaction *t, int error) { |
458 | assert(t); | |
ec2c5e43 | 459 | |
b30bf55d | 460 | dns_transaction_close_connection(t); |
ec2c5e43 | 461 | |
a1a3f73a | 462 | if (ERRNO_IS_DISCONNECT(error)) { |
0791110f LP |
463 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR) { |
464 | /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the | |
465 | * question on this scope. */ | |
466 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
0791110f LP |
467 | } |
468 | ||
d001e0a3 | 469 | dns_transaction_retry(t, true); |
ac720200 | 470 | } |
ec2c5e43 | 471 | if (error != 0) { |
7cc6ed7b LP |
472 | t->answer_errno = error; |
473 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 | 474 | } |
98767d75 IT |
475 | } |
476 | ||
477 | static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsPacket *p) { | |
478 | assert(t); | |
479 | assert(p); | |
480 | ||
481 | dns_transaction_close_connection(t); | |
ec2c5e43 | 482 | |
a4076574 | 483 | if (dns_packet_validate_reply(p) <= 0) { |
a20b9592 | 484 | log_debug("Invalid TCP reply packet."); |
a4076574 LP |
485 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); |
486 | return 0; | |
487 | } | |
488 | ||
489 | dns_scope_check_conflicts(t->scope, p); | |
490 | ||
ec2c5e43 LP |
491 | t->block_gc++; |
492 | dns_transaction_process_reply(t, p); | |
493 | t->block_gc--; | |
494 | ||
519ef046 LP |
495 | /* If the response wasn't useful, then complete the transition |
496 | * now. After all, we are the worst feature set now with TCP | |
497 | * sockets, and there's really no point in retrying. */ | |
ec2c5e43 LP |
498 | if (t->state == DNS_TRANSACTION_PENDING) |
499 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
598f44bd LP |
500 | else |
501 | dns_transaction_gc(t); | |
ec2c5e43 LP |
502 | |
503 | return 0; | |
504 | } | |
505 | ||
5d67a7ae IT |
506 | static int on_stream_connection(DnsStream *s) { |
507 | #if HAVE_GNUTLS | |
508 | /* Store TLS Ticket for faster succesive TLS handshakes */ | |
509 | if (s->tls_session && s->server) { | |
510 | if (s->server->tls_session_data.data) | |
511 | gnutls_free(s->server->tls_session_data.data); | |
512 | ||
513 | gnutls_session_get_data2(s->tls_session, &s->server->tls_session_data); | |
514 | } | |
515 | #endif | |
516 | ||
517 | return 0; | |
518 | } | |
519 | ||
98767d75 IT |
520 | static int on_stream_complete(DnsStream *s, int error) { |
521 | DnsTransaction *t, *n; | |
522 | int r = 0; | |
523 | ||
524 | /* Do not let new transactions use this stream */ | |
525 | if (s->server && s->server->stream == s) | |
526 | s->server->stream = dns_stream_unref(s->server->stream); | |
527 | ||
528 | if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) { | |
529 | usec_t usec; | |
530 | ||
531 | log_debug_errno(error, "Connection failure for DNS TCP stream: %m"); | |
532 | ||
533 | if (s->transactions) { | |
534 | t = s->transactions; | |
535 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); | |
536 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); | |
537 | } | |
538 | } | |
539 | ||
540 | LIST_FOREACH_SAFE(transactions_by_stream, t, n, s->transactions) | |
541 | if (error != 0) | |
542 | on_transaction_stream_error(t, error); | |
543 | else if (DNS_PACKET_ID(s->read_packet) == t->id) | |
544 | /* As each transaction have a unique id the return code is only set once */ | |
545 | r = dns_transaction_on_stream_packet(t, s->read_packet); | |
546 | ||
547 | return r; | |
548 | } | |
549 | ||
550 | static int dns_stream_on_packet(DnsStream *s) { | |
551 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
552 | int r = 0; | |
553 | DnsTransaction *t; | |
554 | ||
555 | /* Take ownership of packet to be able to receive new packets */ | |
556 | p = TAKE_PTR(s->read_packet); | |
557 | s->n_read = 0; | |
558 | ||
559 | t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); | |
560 | ||
561 | /* Ignore incorrect transaction id as transaction can have been canceled */ | |
562 | if (t) | |
563 | r = dns_transaction_on_stream_packet(t, p); | |
564 | else { | |
565 | if (dns_packet_validate_reply(p) <= 0) { | |
566 | log_debug("Invalid TCP reply packet."); | |
567 | on_stream_complete(s, 0); | |
568 | } | |
569 | return 0; | |
570 | } | |
571 | ||
572 | return r; | |
573 | } | |
574 | ||
575 | static int dns_transaction_emit_tcp(DnsTransaction *t) { | |
ec2c5e43 | 576 | _cleanup_close_ int fd = -1; |
98767d75 | 577 | _cleanup_(dns_stream_unrefp) DnsStream *s = NULL; |
91ccab1e | 578 | union sockaddr_union sa; |
ec2c5e43 | 579 | int r; |
5d67a7ae IT |
580 | #if HAVE_GNUTLS |
581 | gnutls_session_t gs; | |
582 | #endif | |
ec2c5e43 LP |
583 | |
584 | assert(t); | |
585 | ||
519ef046 | 586 | dns_transaction_close_connection(t); |
ec2c5e43 | 587 | |
106784eb | 588 | switch (t->scope->protocol) { |
519ef046 | 589 | |
106784eb | 590 | case DNS_PROTOCOL_DNS: |
519ef046 LP |
591 | r = dns_transaction_pick_server(t); |
592 | if (r < 0) | |
593 | return r; | |
594 | ||
92ec902a | 595 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
596 | return -EOPNOTSUPP; |
597 | ||
274b8748 | 598 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
599 | if (r < 0) |
600 | return r; | |
601 | ||
5d67a7ae | 602 | if (t->server->stream && (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) == t->server->stream->encrypted)) |
98767d75 IT |
603 | s = dns_stream_ref(t->server->stream); |
604 | else | |
5d67a7ae | 605 | fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level) ? 853 : 53, &sa); |
98767d75 | 606 | |
106784eb | 607 | break; |
ec2c5e43 | 608 | |
106784eb | 609 | case DNS_PROTOCOL_LLMNR: |
a8f6397f | 610 | /* When we already received a reply to this (but it was truncated), send to its sender address */ |
ec2c5e43 | 611 | if (t->received) |
91ccab1e | 612 | fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port, &sa); |
ec2c5e43 LP |
613 | else { |
614 | union in_addr_union address; | |
a7f7d1bd | 615 | int family = AF_UNSPEC; |
ec2c5e43 LP |
616 | |
617 | /* Otherwise, try to talk to the owner of a | |
618 | * the IP address, in case this is a reverse | |
619 | * PTR lookup */ | |
f52e61da | 620 | |
1c02e7ba | 621 | r = dns_name_address(dns_resource_key_name(t->key), &family, &address); |
ec2c5e43 LP |
622 | if (r < 0) |
623 | return r; | |
624 | if (r == 0) | |
625 | return -EINVAL; | |
9e08a6e0 | 626 | if (family != t->scope->family) |
9318cdd3 | 627 | return -ESRCH; |
ec2c5e43 | 628 | |
91ccab1e | 629 | fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT, &sa); |
ec2c5e43 | 630 | } |
106784eb DM |
631 | |
632 | break; | |
633 | ||
634 | default: | |
ec2c5e43 | 635 | return -EAFNOSUPPORT; |
106784eb | 636 | } |
ec2c5e43 | 637 | |
98767d75 IT |
638 | if (!s) { |
639 | if (fd < 0) | |
640 | return fd; | |
ec2c5e43 | 641 | |
91ccab1e | 642 | r = dns_stream_new(t->scope->manager, &s, t->scope->protocol, fd, &sa); |
98767d75 IT |
643 | if (r < 0) |
644 | return r; | |
645 | ||
646 | fd = -1; | |
647 | ||
648 | if (t->server) { | |
649 | dns_stream_unref(t->server->stream); | |
650 | t->server->stream = dns_stream_ref(s); | |
651 | s->server = dns_server_ref(t->server); | |
652 | } | |
653 | ||
5d67a7ae IT |
654 | #if HAVE_GNUTLS |
655 | if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) { | |
656 | r = gnutls_init(&gs, GNUTLS_CLIENT | GNUTLS_ENABLE_FALSE_START | GNUTLS_NONBLOCK); | |
657 | if (r < 0) | |
658 | return r; | |
659 | ||
660 | /* As DNS-over-TLS is a recent protocol, older TLS versions can be disabled */ | |
661 | r = gnutls_priority_set_direct(gs, "NORMAL:-VERS-ALL:+VERS-TLS1.2", NULL); | |
662 | if (r < 0) | |
663 | return r; | |
664 | ||
665 | r = gnutls_credentials_set(gs, GNUTLS_CRD_CERTIFICATE, t->server->tls_cert_cred); | |
666 | if (r < 0) | |
667 | return r; | |
668 | ||
669 | if (t->server && t->server->tls_session_data.size > 0) | |
670 | gnutls_session_set_data(gs, t->server->tls_session_data.data, t->server->tls_session_data.size); | |
671 | ||
672 | gnutls_handshake_set_timeout(gs, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT); | |
673 | ||
674 | r = dns_stream_connect_tls(s, gs); | |
675 | if (r < 0) | |
676 | return r; | |
677 | } | |
678 | #endif | |
679 | ||
680 | s->on_connection = on_stream_connection; | |
98767d75 IT |
681 | s->complete = on_stream_complete; |
682 | s->on_packet = dns_stream_on_packet; | |
683 | ||
684 | /* The interface index is difficult to determine if we are | |
685 | * connecting to the local host, hence fill this in right away | |
686 | * instead of determining it from the socket */ | |
687 | s->ifindex = dns_scope_ifindex(t->scope); | |
688 | } | |
689 | ||
690 | t->stream = TAKE_PTR(s); | |
691 | LIST_PREPEND(transactions_by_stream, t->stream->transactions, t); | |
ec2c5e43 LP |
692 | |
693 | r = dns_stream_write_packet(t->stream, t->sent); | |
694 | if (r < 0) { | |
98767d75 | 695 | dns_transaction_close_connection(t); |
ec2c5e43 LP |
696 | return r; |
697 | } | |
698 | ||
519ef046 LP |
699 | dns_transaction_reset_answer(t); |
700 | ||
cbe4216d LP |
701 | t->tried_stream = true; |
702 | ||
ec2c5e43 LP |
703 | return 0; |
704 | } | |
705 | ||
547973de | 706 | static void dns_transaction_cache_answer(DnsTransaction *t) { |
547973de LP |
707 | assert(t); |
708 | ||
709 | /* For mDNS we cache whenever we get the packet, rather than | |
710 | * in each transaction. */ | |
711 | if (!IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) | |
712 | return; | |
713 | ||
ceeddf79 MP |
714 | /* Caching disabled? */ |
715 | if (!t->scope->manager->enable_cache) | |
716 | return; | |
717 | ||
547973de LP |
718 | /* We never cache if this packet is from the local host, under |
719 | * the assumption that a locally running DNS server would | |
720 | * cache this anyway, and probably knows better when to flush | |
721 | * the cache then we could. */ | |
722 | if (!DNS_PACKET_SHALL_CACHE(t->received)) | |
723 | return; | |
724 | ||
547973de LP |
725 | dns_cache_put(&t->scope->cache, |
726 | t->key, | |
727 | t->answer_rcode, | |
728 | t->answer, | |
547973de | 729 | t->answer_authenticated, |
d3760be0 | 730 | t->answer_nsec_ttl, |
547973de LP |
731 | 0, |
732 | t->received->family, | |
733 | &t->received->sender); | |
734 | } | |
735 | ||
105e1512 LP |
736 | static bool dns_transaction_dnssec_is_live(DnsTransaction *t) { |
737 | DnsTransaction *dt; | |
738 | Iterator i; | |
739 | ||
740 | assert(t); | |
741 | ||
742 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
743 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
744 | return true; | |
745 | ||
746 | return false; | |
747 | } | |
748 | ||
942eb2e7 LP |
749 | static int dns_transaction_dnssec_ready(DnsTransaction *t) { |
750 | DnsTransaction *dt; | |
751 | Iterator i; | |
752 | ||
753 | assert(t); | |
754 | ||
755 | /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still | |
756 | * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */ | |
757 | ||
758 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
759 | ||
760 | switch (dt->state) { | |
761 | ||
762 | case DNS_TRANSACTION_NULL: | |
763 | case DNS_TRANSACTION_PENDING: | |
764 | case DNS_TRANSACTION_VALIDATING: | |
765 | /* Still ongoing */ | |
766 | return 0; | |
767 | ||
768 | case DNS_TRANSACTION_RCODE_FAILURE: | |
b3c6b00a | 769 | if (!IN_SET(dt->answer_rcode, DNS_RCODE_NXDOMAIN, DNS_RCODE_SERVFAIL)) { |
942eb2e7 LP |
770 | log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt->answer_rcode)); |
771 | goto fail; | |
772 | } | |
773 | ||
b3c6b00a LP |
774 | /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers |
775 | * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS | |
776 | * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar | |
777 | * RRs to make unsigned proofs. */ | |
942eb2e7 LP |
778 | |
779 | case DNS_TRANSACTION_SUCCESS: | |
780 | /* All good. */ | |
781 | break; | |
782 | ||
783 | case DNS_TRANSACTION_DNSSEC_FAILED: | |
784 | /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC | |
785 | * validationr result */ | |
786 | ||
787 | log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt->answer_dnssec_result)); | |
788 | t->answer_dnssec_result = dt->answer_dnssec_result; /* Copy error code over */ | |
789 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
790 | return 0; | |
791 | ||
942eb2e7 LP |
792 | default: |
793 | log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt->state)); | |
794 | goto fail; | |
795 | } | |
796 | } | |
797 | ||
798 | /* All is ready, we can go and validate */ | |
799 | return 1; | |
800 | ||
801 | fail: | |
802 | t->answer_dnssec_result = DNSSEC_FAILED_AUXILIARY; | |
803 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); | |
804 | return 0; | |
805 | } | |
806 | ||
547973de LP |
807 | static void dns_transaction_process_dnssec(DnsTransaction *t) { |
808 | int r; | |
809 | ||
810 | assert(t); | |
811 | ||
812 | /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */ | |
942eb2e7 | 813 | r = dns_transaction_dnssec_ready(t); |
7cc6ed7b LP |
814 | if (r < 0) |
815 | goto fail; | |
942eb2e7 | 816 | if (r == 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */ |
547973de LP |
817 | return; |
818 | ||
c02cf2f4 LP |
819 | /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better |
820 | * restart the lookup immediately. */ | |
821 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
822 | if (r < 0) |
823 | goto fail; | |
c02cf2f4 LP |
824 | if (r > 0) /* Transaction got restarted... */ |
825 | return; | |
826 | ||
547973de LP |
827 | /* All our auxiliary DNSSEC transactions are complete now. Try |
828 | * to validate our RRset now. */ | |
829 | r = dns_transaction_validate_dnssec(t); | |
fcfaff12 LP |
830 | if (r == -EBADMSG) { |
831 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
832 | return; | |
833 | } | |
7cc6ed7b LP |
834 | if (r < 0) |
835 | goto fail; | |
547973de | 836 | |
b652d4a2 LP |
837 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER && |
838 | t->scope->dnssec_mode == DNSSEC_YES) { | |
e82b1132 LP |
839 | |
840 | /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe | |
841 | * that works. */ | |
842 | ||
843 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { | |
844 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
845 | dns_transaction_retry(t, true); | |
846 | return; | |
847 | } | |
848 | ||
849 | /* OK, let's give up, apparently all servers we tried didn't work. */ | |
b652d4a2 LP |
850 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
851 | return; | |
852 | } | |
853 | ||
019036a4 | 854 | if (!IN_SET(t->answer_dnssec_result, |
b652d4a2 LP |
855 | _DNSSEC_RESULT_INVALID, /* No DNSSEC validation enabled */ |
856 | DNSSEC_VALIDATED, /* Answer is signed and validated successfully */ | |
857 | DNSSEC_UNSIGNED, /* Answer is right-fully unsigned */ | |
858 | DNSSEC_INCOMPATIBLE_SERVER)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */ | |
547973de LP |
859 | dns_transaction_complete(t, DNS_TRANSACTION_DNSSEC_FAILED); |
860 | return; | |
861 | } | |
862 | ||
1e02e182 LP |
863 | if (t->answer_dnssec_result == DNSSEC_INCOMPATIBLE_SERVER) |
864 | dns_server_warn_downgrade(t->server); | |
865 | ||
547973de LP |
866 | dns_transaction_cache_answer(t); |
867 | ||
868 | if (t->answer_rcode == DNS_RCODE_SUCCESS) | |
869 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
870 | else | |
3bbdc31d | 871 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
7cc6ed7b LP |
872 | |
873 | return; | |
874 | ||
875 | fail: | |
876 | t->answer_errno = -r; | |
877 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
547973de LP |
878 | } |
879 | ||
eac7cda2 LP |
880 | static int dns_transaction_has_positive_answer(DnsTransaction *t, DnsAnswerFlags *flags) { |
881 | int r; | |
882 | ||
883 | assert(t); | |
884 | ||
885 | /* Checks whether the answer is positive, i.e. either a direct | |
886 | * answer to the question, or a CNAME/DNAME for it */ | |
887 | ||
888 | r = dns_answer_match_key(t->answer, t->key, flags); | |
889 | if (r != 0) | |
890 | return r; | |
891 | ||
892 | r = dns_answer_find_cname_or_dname(t->answer, t->key, NULL, flags); | |
893 | if (r != 0) | |
894 | return r; | |
895 | ||
896 | return false; | |
897 | } | |
898 | ||
899 | static int dns_transaction_fix_rcode(DnsTransaction *t) { | |
900 | int r; | |
901 | ||
902 | assert(t); | |
903 | ||
904 | /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the | |
905 | * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a | |
906 | * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first | |
907 | * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when | |
908 | * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle | |
909 | * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a | |
910 | * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server | |
911 | * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an | |
912 | * incomplete CNAME/DNAME chain. | |
913 | * | |
914 | * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS, | |
915 | * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new | |
916 | * lookup. */ | |
917 | ||
918 | if (t->answer_rcode != DNS_RCODE_NXDOMAIN) | |
919 | return 0; | |
920 | ||
921 | r = dns_transaction_has_positive_answer(t, NULL); | |
922 | if (r <= 0) | |
923 | return r; | |
924 | ||
925 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
926 | return 0; | |
927 | } | |
928 | ||
ec2c5e43 | 929 | void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { |
9df3ba6c | 930 | usec_t ts; |
ec2c5e43 LP |
931 | int r; |
932 | ||
933 | assert(t); | |
934 | assert(p); | |
9df3ba6c TG |
935 | assert(t->scope); |
936 | assert(t->scope->manager); | |
ec2c5e43 | 937 | |
5a7e41a3 LP |
938 | if (t->state != DNS_TRANSACTION_PENDING) |
939 | return; | |
940 | ||
ec2c5e43 LP |
941 | /* Note that this call might invalidate the query. Callers |
942 | * should hence not attempt to access the query or transaction | |
943 | * after calling this function. */ | |
944 | ||
1fdeaeb7 | 945 | log_debug("Processing incoming packet on transaction %" PRIu16". (rcode=%s)", t->id, dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
b5efcf29 | 946 | |
106784eb | 947 | switch (t->scope->protocol) { |
b5efcf29 | 948 | |
106784eb | 949 | case DNS_PROTOCOL_LLMNR: |
97ebebbc | 950 | /* For LLMNR we will not accept any packets from other interfaces */ |
ec2c5e43 | 951 | |
97ebebbc | 952 | if (p->ifindex != dns_scope_ifindex(t->scope)) |
ec2c5e43 LP |
953 | return; |
954 | ||
955 | if (p->family != t->scope->family) | |
956 | return; | |
957 | ||
958 | /* Tentative packets are not full responses but still | |
959 | * useful for identifying uniqueness conflicts during | |
960 | * probing. */ | |
8b757a38 | 961 | if (DNS_PACKET_LLMNR_T(p)) { |
ec2c5e43 LP |
962 | dns_transaction_tentative(t, p); |
963 | return; | |
964 | } | |
106784eb DM |
965 | |
966 | break; | |
967 | ||
4e5bf5e1 | 968 | case DNS_PROTOCOL_MDNS: |
4e5bf5e1 | 969 | /* For mDNS we will not accept any packets from other interfaces */ |
97ebebbc LP |
970 | |
971 | if (p->ifindex != dns_scope_ifindex(t->scope)) | |
4e5bf5e1 DM |
972 | return; |
973 | ||
974 | if (p->family != t->scope->family) | |
975 | return; | |
976 | ||
977 | break; | |
978 | ||
106784eb | 979 | case DNS_PROTOCOL_DNS: |
8ad182a1 LP |
980 | /* Note that we do not need to verify the |
981 | * addresses/port numbers of incoming traffic, as we | |
982 | * invoked connect() on our UDP socket in which case | |
983 | * the kernel already does the needed verification for | |
984 | * us. */ | |
106784eb DM |
985 | break; |
986 | ||
987 | default: | |
9c56a6f3 | 988 | assert_not_reached("Invalid DNS protocol."); |
ec2c5e43 LP |
989 | } |
990 | ||
ec2c5e43 LP |
991 | if (t->received != p) { |
992 | dns_packet_unref(t->received); | |
993 | t->received = dns_packet_ref(p); | |
994 | } | |
995 | ||
c3bc53e6 LP |
996 | t->answer_source = DNS_TRANSACTION_NETWORK; |
997 | ||
ec2c5e43 LP |
998 | if (p->ipproto == IPPROTO_TCP) { |
999 | if (DNS_PACKET_TC(p)) { | |
1000 | /* Truncated via TCP? Somebody must be fucking with us */ | |
1001 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1002 | return; | |
1003 | } | |
1004 | ||
1005 | if (DNS_PACKET_ID(p) != t->id) { | |
1006 | /* Not the reply to our query? Somebody must be fucking with us */ | |
1007 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1008 | return; | |
1009 | } | |
1010 | } | |
1011 | ||
38a03f06 | 1012 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
9df3ba6c TG |
1013 | |
1014 | switch (t->scope->protocol) { | |
8af5b883 | 1015 | |
9df3ba6c TG |
1016 | case DNS_PROTOCOL_DNS: |
1017 | assert(t->server); | |
1018 | ||
4e0b8b17 TG |
1019 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_FORMERR, DNS_RCODE_SERVFAIL, DNS_RCODE_NOTIMP)) { |
1020 | ||
8af5b883 | 1021 | /* Request failed, immediately try again with reduced features */ |
4e0b8b17 | 1022 | |
7d581a65 | 1023 | if (t->current_feature_level <= DNS_SERVER_FEATURE_LEVEL_UDP) { |
44db02d0 | 1024 | |
7d581a65 | 1025 | /* This was already at UDP feature level? If so, it doesn't make sense to downgrade |
44db02d0 LP |
1026 | * this transaction anymore, but let's see if it might make sense to send the request |
1027 | * to a different DNS server instead. If not let's process the response, and accept the | |
7d581a65 LP |
1028 | * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate |
1029 | * packet loss, but is not going to give us better rcodes should we actually have | |
1030 | * managed to get them already at UDP level. */ | |
1031 | ||
44db02d0 LP |
1032 | if (t->n_picked_servers < dns_scope_get_n_dns_servers(t->scope)) { |
1033 | /* We tried fewer servers on this transaction than we know, let's try another one then */ | |
1034 | dns_transaction_retry(t, true); | |
1035 | return; | |
1036 | } | |
1037 | ||
1038 | /* Give up, accept the rcode */ | |
d001e0a3 LP |
1039 | log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p))); |
1040 | break; | |
1041 | } | |
1042 | ||
1043 | /* Reduce this feature level by one and try again. */ | |
5d67a7ae IT |
1044 | switch (t->current_feature_level) { |
1045 | case DNS_SERVER_FEATURE_LEVEL_TLS_DO: | |
1046 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN; | |
1047 | break; | |
1048 | case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN + 1: | |
1049 | /* Skip plain TLS when TLS is not supported */ | |
1050 | t->clamp_feature_level = DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN - 1; | |
1051 | break; | |
1052 | default: | |
1053 | t->clamp_feature_level = t->current_feature_level - 1; | |
1054 | } | |
d001e0a3 LP |
1055 | |
1056 | log_debug("Server returned error %s, retrying transaction with reduced feature level %s.", | |
1057 | dns_rcode_to_string(DNS_PACKET_RCODE(p)), | |
1058 | dns_server_feature_level_to_string(t->clamp_feature_level)); | |
1059 | ||
1060 | dns_transaction_retry(t, false /* use the same server */); | |
4e0b8b17 | 1061 | return; |
eb08640a LP |
1062 | } |
1063 | ||
1064 | if (DNS_PACKET_RCODE(p) == DNS_RCODE_REFUSED) { | |
1065 | /* This server refused our request? If so, try again, use a different server */ | |
1066 | log_debug("Server returned REFUSED, switching servers, and retrying."); | |
1067 | dns_transaction_retry(t, true /* pick a new server */); | |
1068 | return; | |
1069 | } | |
1070 | ||
1071 | if (DNS_PACKET_TC(p)) | |
274b8748 | 1072 | dns_server_packet_truncated(t->server, t->current_feature_level); |
9df3ba6c TG |
1073 | |
1074 | break; | |
8af5b883 | 1075 | |
9df3ba6c TG |
1076 | case DNS_PROTOCOL_LLMNR: |
1077 | case DNS_PROTOCOL_MDNS: | |
1078 | dns_scope_packet_received(t->scope, ts - t->start_usec); | |
9df3ba6c | 1079 | break; |
8af5b883 | 1080 | |
9df3ba6c | 1081 | default: |
8af5b883 | 1082 | assert_not_reached("Invalid DNS protocol."); |
9df3ba6c TG |
1083 | } |
1084 | ||
ec2c5e43 | 1085 | if (DNS_PACKET_TC(p)) { |
547493c5 DM |
1086 | |
1087 | /* Truncated packets for mDNS are not allowed. Give up immediately. */ | |
1088 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) { | |
1089 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1090 | return; | |
1091 | } | |
1092 | ||
f757cd85 LP |
1093 | log_debug("Reply truncated, retrying via TCP."); |
1094 | ||
ec2c5e43 | 1095 | /* Response was truncated, let's try again with good old TCP */ |
98767d75 | 1096 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 LP |
1097 | if (r == -ESRCH) { |
1098 | /* No servers found? Damn! */ | |
1099 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1100 | return; | |
1101 | } | |
91adc4db LP |
1102 | if (r == -EOPNOTSUPP) { |
1103 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1104 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1105 | return; | |
1106 | } | |
ec2c5e43 | 1107 | if (r < 0) { |
8af5b883 | 1108 | /* On LLMNR, if we cannot connect to the host, |
ec2c5e43 | 1109 | * we immediately give up */ |
7cc6ed7b LP |
1110 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1111 | goto fail; | |
ec2c5e43 LP |
1112 | |
1113 | /* On DNS, couldn't send? Try immediately again, with a new server */ | |
d001e0a3 | 1114 | dns_transaction_retry(t, true); |
ec2c5e43 | 1115 | } |
2a6658ef LP |
1116 | |
1117 | return; | |
ec2c5e43 LP |
1118 | } |
1119 | ||
de54e62b | 1120 | /* After the superficial checks, actually parse the message. */ |
ec2c5e43 LP |
1121 | r = dns_packet_extract(p); |
1122 | if (r < 0) { | |
1123 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1124 | return; | |
1125 | } | |
1126 | ||
ed9717fc | 1127 | if (t->server) { |
d001e0a3 LP |
1128 | /* Report that we successfully received a valid packet with a good rcode after we initially got a bad |
1129 | * rcode and subsequently downgraded the protocol */ | |
1130 | ||
1131 | if (IN_SET(DNS_PACKET_RCODE(p), DNS_RCODE_SUCCESS, DNS_RCODE_NXDOMAIN) && | |
1132 | t->clamp_feature_level != _DNS_SERVER_FEATURE_LEVEL_INVALID) | |
1133 | dns_server_packet_rcode_downgrade(t->server, t->clamp_feature_level); | |
1134 | ||
1135 | /* Report that the OPT RR was missing */ | |
ed9717fc LP |
1136 | if (!p->opt) |
1137 | dns_server_packet_bad_opt(t->server, t->current_feature_level); | |
1138 | ||
d001e0a3 | 1139 | /* Report that we successfully received a packet */ |
ed9717fc LP |
1140 | dns_server_packet_received(t->server, p->ipproto, t->current_feature_level, ts - t->start_usec, p->size); |
1141 | } | |
de54e62b | 1142 | |
c02cf2f4 LP |
1143 | /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */ |
1144 | r = dns_transaction_maybe_restart(t); | |
7cc6ed7b LP |
1145 | if (r < 0) |
1146 | goto fail; | |
c02cf2f4 LP |
1147 | if (r > 0) /* Transaction got restarted... */ |
1148 | return; | |
1149 | ||
8b419837 | 1150 | if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
b5efcf29 | 1151 | |
8b419837 DR |
1152 | /* When dealing with protocols other than mDNS only consider responses with |
1153 | * equivalent query section to the request. For mDNS this check doesn't make | |
1154 | * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT | |
1155 | * contain any questions in the Question Section". */ | |
1156 | if (t->scope->protocol != DNS_PROTOCOL_MDNS) { | |
1157 | r = dns_packet_is_reply_for(p, t->key); | |
1158 | if (r < 0) | |
1159 | goto fail; | |
1160 | if (r == 0) { | |
1161 | dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); | |
1162 | return; | |
1163 | } | |
547493c5 | 1164 | } |
29815b6c | 1165 | |
547493c5 DM |
1166 | /* Install the answer as answer to the transaction */ |
1167 | dns_answer_unref(t->answer); | |
1168 | t->answer = dns_answer_ref(p->answer); | |
1169 | t->answer_rcode = DNS_PACKET_RCODE(p); | |
919c2ae0 | 1170 | t->answer_dnssec_result = _DNSSEC_RESULT_INVALID; |
105e1512 | 1171 | t->answer_authenticated = false; |
79e24931 | 1172 | |
eac7cda2 LP |
1173 | r = dns_transaction_fix_rcode(t); |
1174 | if (r < 0) | |
1175 | goto fail; | |
1176 | ||
51e399bc LP |
1177 | /* Block GC while starting requests for additional DNSSEC RRs */ |
1178 | t->block_gc++; | |
547973de | 1179 | r = dns_transaction_request_dnssec_keys(t); |
51e399bc LP |
1180 | t->block_gc--; |
1181 | ||
1182 | /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */ | |
1183 | if (!dns_transaction_gc(t)) | |
1184 | return; | |
1185 | ||
1186 | /* Requesting additional keys might have resulted in | |
1187 | * this transaction to fail, since the auxiliary | |
1188 | * request failed for some reason. If so, we are not | |
1189 | * in pending state anymore, and we should exit | |
1190 | * quickly. */ | |
1191 | if (t->state != DNS_TRANSACTION_PENDING) | |
1192 | return; | |
7cc6ed7b LP |
1193 | if (r < 0) |
1194 | goto fail; | |
547973de LP |
1195 | if (r > 0) { |
1196 | /* There are DNSSEC transactions pending now. Update the state accordingly. */ | |
1197 | t->state = DNS_TRANSACTION_VALIDATING; | |
f535705a LP |
1198 | dns_transaction_close_connection(t); |
1199 | dns_transaction_stop_timeout(t); | |
547973de LP |
1200 | return; |
1201 | } | |
547493c5 | 1202 | } |
ec2c5e43 | 1203 | |
547973de | 1204 | dns_transaction_process_dnssec(t); |
7cc6ed7b LP |
1205 | return; |
1206 | ||
1207 | fail: | |
1208 | t->answer_errno = -r; | |
1209 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); | |
ec2c5e43 LP |
1210 | } |
1211 | ||
c19ffd9f TG |
1212 | static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { |
1213 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1214 | DnsTransaction *t = userdata; | |
1215 | int r; | |
1216 | ||
1217 | assert(t); | |
1218 | assert(t->scope); | |
1219 | ||
1220 | r = manager_recv(t->scope->manager, fd, DNS_PROTOCOL_DNS, &p); | |
7e1851e3 LP |
1221 | if (ERRNO_IS_DISCONNECT(-r)) { |
1222 | usec_t usec; | |
c19ffd9f | 1223 | |
7e1851e3 LP |
1224 | /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next |
1225 | * recvmsg(). Treat this like a lost packet. */ | |
1226 | ||
92ec902a | 1227 | log_debug_errno(r, "Connection failure for DNS UDP packet: %m"); |
7e1851e3 | 1228 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0); |
274b8748 | 1229 | dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
7e1851e3 | 1230 | |
d001e0a3 | 1231 | dns_transaction_retry(t, true); |
7e1851e3 LP |
1232 | return 0; |
1233 | } | |
1234 | if (r < 0) { | |
7cc6ed7b LP |
1235 | dns_transaction_complete(t, DNS_TRANSACTION_ERRNO); |
1236 | t->answer_errno = -r; | |
7e1851e3 LP |
1237 | return 0; |
1238 | } | |
1239 | ||
1240 | r = dns_packet_validate_reply(p); | |
1241 | if (r < 0) { | |
1242 | log_debug_errno(r, "Received invalid DNS packet as response, ignoring: %m"); | |
1243 | return 0; | |
1244 | } | |
1245 | if (r == 0) { | |
e09f605e | 1246 | log_debug("Received inappropriate DNS packet as response, ignoring."); |
7e1851e3 LP |
1247 | return 0; |
1248 | } | |
1249 | ||
1250 | if (DNS_PACKET_ID(p) != t->id) { | |
e09f605e | 1251 | log_debug("Received packet with incorrect transaction ID, ignoring."); |
7e1851e3 LP |
1252 | return 0; |
1253 | } | |
c19ffd9f | 1254 | |
7e1851e3 | 1255 | dns_transaction_process_reply(t, p); |
c19ffd9f TG |
1256 | return 0; |
1257 | } | |
1258 | ||
49cce12d | 1259 | static int dns_transaction_emit_udp(DnsTransaction *t) { |
c19ffd9f TG |
1260 | int r; |
1261 | ||
1262 | assert(t); | |
c19ffd9f | 1263 | |
519ef046 | 1264 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { |
c19ffd9f | 1265 | |
519ef046 | 1266 | r = dns_transaction_pick_server(t); |
471d40d9 TG |
1267 | if (r < 0) |
1268 | return r; | |
c19ffd9f | 1269 | |
5d67a7ae | 1270 | if (t->current_feature_level < DNS_SERVER_FEATURE_LEVEL_UDP || DNS_SERVER_FEATURE_LEVEL_IS_TLS(t->current_feature_level)) |
7d581a65 | 1271 | return -EAGAIN; /* Sorry, can't do UDP, try TCP! */ |
519ef046 | 1272 | |
92ec902a | 1273 | if (!dns_server_dnssec_supported(t->server) && dns_type_is_dnssec(t->key->type)) |
91adc4db LP |
1274 | return -EOPNOTSUPP; |
1275 | ||
519ef046 LP |
1276 | if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */ |
1277 | int fd; | |
1278 | ||
1279 | dns_transaction_close_connection(t); | |
c19ffd9f | 1280 | |
519ef046 LP |
1281 | fd = dns_scope_socket_udp(t->scope, t->server, 53); |
1282 | if (fd < 0) | |
1283 | return fd; | |
1284 | ||
1285 | r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t); | |
1286 | if (r < 0) { | |
1287 | safe_close(fd); | |
1288 | return r; | |
1289 | } | |
1290 | ||
aa4a9deb | 1291 | (void) sd_event_source_set_description(t->dns_udp_event_source, "dns-transaction-udp"); |
519ef046 LP |
1292 | t->dns_udp_fd = fd; |
1293 | } | |
1294 | ||
274b8748 | 1295 | r = dns_server_adjust_opt(t->server, t->sent, t->current_feature_level); |
519ef046 LP |
1296 | if (r < 0) |
1297 | return r; | |
1298 | } else | |
1299 | dns_transaction_close_connection(t); | |
1300 | ||
1301 | r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent); | |
471d40d9 TG |
1302 | if (r < 0) |
1303 | return r; | |
c19ffd9f | 1304 | |
519ef046 | 1305 | dns_transaction_reset_answer(t); |
be808ea0 | 1306 | |
471d40d9 | 1307 | return 0; |
c19ffd9f TG |
1308 | } |
1309 | ||
ec2c5e43 LP |
1310 | static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) { |
1311 | DnsTransaction *t = userdata; | |
ec2c5e43 LP |
1312 | |
1313 | assert(s); | |
1314 | assert(t); | |
1315 | ||
ef7ce6df DM |
1316 | if (!t->initial_jitter_scheduled || t->initial_jitter_elapsed) { |
1317 | /* Timeout reached? Increase the timeout for the server used */ | |
1318 | switch (t->scope->protocol) { | |
49cce12d | 1319 | |
ef7ce6df DM |
1320 | case DNS_PROTOCOL_DNS: |
1321 | assert(t->server); | |
274b8748 | 1322 | dns_server_packet_lost(t->server, t->stream ? IPPROTO_TCP : IPPROTO_UDP, t->current_feature_level, usec - t->start_usec); |
ef7ce6df | 1323 | break; |
49cce12d | 1324 | |
ef7ce6df DM |
1325 | case DNS_PROTOCOL_LLMNR: |
1326 | case DNS_PROTOCOL_MDNS: | |
1327 | dns_scope_packet_lost(t->scope, usec - t->start_usec); | |
ef7ce6df | 1328 | break; |
49cce12d | 1329 | |
ef7ce6df DM |
1330 | default: |
1331 | assert_not_reached("Invalid DNS protocol."); | |
1332 | } | |
1333 | ||
1334 | if (t->initial_jitter_scheduled) | |
1335 | t->initial_jitter_elapsed = true; | |
be808ea0 TG |
1336 | } |
1337 | ||
423659ab LP |
1338 | log_debug("Timeout reached on transaction %" PRIu16 ".", t->id); |
1339 | ||
d001e0a3 | 1340 | dns_transaction_retry(t, true); |
ec2c5e43 LP |
1341 | return 0; |
1342 | } | |
1343 | ||
9df3ba6c TG |
1344 | static usec_t transaction_get_resend_timeout(DnsTransaction *t) { |
1345 | assert(t); | |
1346 | assert(t->scope); | |
1347 | ||
1348 | switch (t->scope->protocol) { | |
49cce12d | 1349 | |
9df3ba6c | 1350 | case DNS_PROTOCOL_DNS: |
dc349f5f LP |
1351 | |
1352 | /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly | |
1353 | * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that | |
1354 | * needlessly. */ | |
1355 | if (t->stream) | |
1356 | return TRANSACTION_TCP_TIMEOUT_USEC; | |
1357 | ||
9df3ba6c | 1358 | assert(t->server); |
9df3ba6c | 1359 | return t->server->resend_timeout; |
49cce12d | 1360 | |
9df3ba6c | 1361 | case DNS_PROTOCOL_MDNS: |
11a27c2e | 1362 | assert(t->n_attempts > 0); |
53fda2bb DR |
1363 | if (t->probing) |
1364 | return MDNS_PROBING_INTERVAL_USEC; | |
1365 | else | |
1366 | return (1 << (t->n_attempts - 1)) * USEC_PER_SEC; | |
49cce12d | 1367 | |
11a27c2e | 1368 | case DNS_PROTOCOL_LLMNR: |
9df3ba6c | 1369 | return t->scope->resend_timeout; |
49cce12d | 1370 | |
9df3ba6c TG |
1371 | default: |
1372 | assert_not_reached("Invalid DNS protocol."); | |
1373 | } | |
1374 | } | |
1375 | ||
c842ff24 | 1376 | static int dns_transaction_prepare(DnsTransaction *t, usec_t ts) { |
ec2c5e43 LP |
1377 | int r; |
1378 | ||
1379 | assert(t); | |
1380 | ||
f535705a | 1381 | dns_transaction_stop_timeout(t); |
ec2c5e43 | 1382 | |
edbcc1fd LP |
1383 | r = dns_scope_network_good(t->scope); |
1384 | if (r < 0) | |
1385 | return r; | |
1386 | if (r == 0) { | |
1387 | dns_transaction_complete(t, DNS_TRANSACTION_NETWORK_DOWN); | |
1388 | return 0; | |
1389 | } | |
1390 | ||
ec2c5e43 LP |
1391 | if (t->n_attempts >= TRANSACTION_ATTEMPTS_MAX(t->scope->protocol)) { |
1392 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1393 | return 0; | |
1394 | } | |
1395 | ||
cbe4216d | 1396 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && t->tried_stream) { |
ec2c5e43 LP |
1397 | /* If we already tried via a stream, then we don't |
1398 | * retry on LLMNR. See RFC 4795, Section 2.7. */ | |
1399 | dns_transaction_complete(t, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED); | |
1400 | return 0; | |
1401 | } | |
1402 | ||
1403 | t->n_attempts++; | |
9df3ba6c | 1404 | t->start_usec = ts; |
c61d2b44 LP |
1405 | |
1406 | dns_transaction_reset_answer(t); | |
c5b4f861 | 1407 | dns_transaction_flush_dnssec_transactions(t); |
ec2c5e43 | 1408 | |
0d2cd476 LP |
1409 | /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */ |
1410 | if (t->scope->protocol == DNS_PROTOCOL_DNS) { | |
8e54f5d9 | 1411 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, t->key, &t->answer); |
0d2cd476 LP |
1412 | if (r < 0) |
1413 | return r; | |
1414 | if (r > 0) { | |
1415 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1416 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
931851e8 | 1417 | t->answer_authenticated = true; |
0d2cd476 LP |
1418 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1419 | return 0; | |
1420 | } | |
b2b796b8 | 1421 | |
1c02e7ba | 1422 | if (dns_name_is_root(dns_resource_key_name(t->key)) && |
b2b796b8 LP |
1423 | t->key->type == DNS_TYPE_DS) { |
1424 | ||
1425 | /* Hmm, this is a request for the root DS? A | |
1426 | * DS RR doesn't exist in the root zone, and | |
1427 | * if our trust anchor didn't know it either, | |
1428 | * this means we cannot do any DNSSEC logic | |
1429 | * anymore. */ | |
1430 | ||
1ed8c0fb | 1431 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
b2b796b8 LP |
1432 | /* We are in downgrade mode. In this |
1433 | * case, synthesize an unsigned empty | |
1434 | * response, so that the any lookup | |
1435 | * depending on this one can continue | |
1436 | * assuming there was no DS, and hence | |
1437 | * the root zone was unsigned. */ | |
1438 | ||
1439 | t->answer_rcode = DNS_RCODE_SUCCESS; | |
1440 | t->answer_source = DNS_TRANSACTION_TRUST_ANCHOR; | |
1441 | t->answer_authenticated = false; | |
1442 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); | |
1443 | } else | |
1444 | /* If we are not in downgrade mode, | |
1445 | * then fail the lookup, because we | |
1446 | * cannot reasonably answer it. There | |
1447 | * might be DS RRs, but we don't know | |
1448 | * them, and the DNS server won't tell | |
1449 | * them to us (and even if it would, | |
202b76ae | 1450 | * we couldn't validate and trust them. */ |
b2b796b8 LP |
1451 | dns_transaction_complete(t, DNS_TRANSACTION_NO_TRUST_ANCHOR); |
1452 | ||
1453 | return 0; | |
1454 | } | |
0d2cd476 LP |
1455 | } |
1456 | ||
1457 | /* Check the zone, but only if this transaction is not used | |
d746bb3e | 1458 | * for probing or verifying a zone item. */ |
547973de | 1459 | if (set_isempty(t->notify_zone_items)) { |
d746bb3e | 1460 | |
97ebebbc | 1461 | r = dns_zone_lookup(&t->scope->zone, t->key, dns_scope_ifindex(t->scope), &t->answer, NULL, NULL); |
d746bb3e LP |
1462 | if (r < 0) |
1463 | return r; | |
1464 | if (r > 0) { | |
ae6a4bbf | 1465 | t->answer_rcode = DNS_RCODE_SUCCESS; |
c3bc53e6 | 1466 | t->answer_source = DNS_TRANSACTION_ZONE; |
931851e8 | 1467 | t->answer_authenticated = true; |
d746bb3e LP |
1468 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1469 | return 0; | |
1470 | } | |
1471 | } | |
1472 | ||
4d926a69 LP |
1473 | /* Check the cache, but only if this transaction is not used |
1474 | * for probing or verifying a zone item. */ | |
547973de | 1475 | if (set_isempty(t->notify_zone_items)) { |
2c27fbca | 1476 | |
4d926a69 LP |
1477 | /* Before trying the cache, let's make sure we figured out a |
1478 | * server to use. Should this cause a change of server this | |
1479 | * might flush the cache. */ | |
5cdb8930 | 1480 | (void) dns_scope_get_dns_server(t->scope); |
2c27fbca | 1481 | |
4d926a69 LP |
1482 | /* Let's then prune all outdated entries */ |
1483 | dns_cache_prune(&t->scope->cache); | |
1484 | ||
17c8de63 | 1485 | r = dns_cache_lookup(&t->scope->cache, t->key, t->clamp_ttl, &t->answer_rcode, &t->answer, &t->answer_authenticated); |
4d926a69 LP |
1486 | if (r < 0) |
1487 | return r; | |
1488 | if (r > 0) { | |
c3bc53e6 | 1489 | t->answer_source = DNS_TRANSACTION_CACHE; |
ae6a4bbf | 1490 | if (t->answer_rcode == DNS_RCODE_SUCCESS) |
4d926a69 LP |
1491 | dns_transaction_complete(t, DNS_TRANSACTION_SUCCESS); |
1492 | else | |
3bbdc31d | 1493 | dns_transaction_complete(t, DNS_TRANSACTION_RCODE_FAILURE); |
4d926a69 LP |
1494 | return 0; |
1495 | } | |
ec2c5e43 LP |
1496 | } |
1497 | ||
1effe965 DM |
1498 | return 1; |
1499 | } | |
1500 | ||
0afa57e2 DM |
1501 | static int dns_transaction_make_packet_mdns(DnsTransaction *t) { |
1502 | ||
1503 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
7778dfff | 1504 | bool add_known_answers = false; |
0afa57e2 | 1505 | DnsTransaction *other; |
0d5ee47d DR |
1506 | Iterator i; |
1507 | DnsResourceKey *tkey; | |
1508 | _cleanup_set_free_ Set *keys = NULL; | |
0afa57e2 | 1509 | unsigned qdcount; |
0d5ee47d | 1510 | unsigned nscount = 0; |
0afa57e2 DM |
1511 | usec_t ts; |
1512 | int r; | |
1513 | ||
1514 | assert(t); | |
1515 | assert(t->scope->protocol == DNS_PROTOCOL_MDNS); | |
1516 | ||
e5abebab | 1517 | /* Discard any previously prepared packet, so we can start over and coalesce again */ |
0afa57e2 DM |
1518 | t->sent = dns_packet_unref(t->sent); |
1519 | ||
1520 | r = dns_packet_new_query(&p, t->scope->protocol, 0, false); | |
1521 | if (r < 0) | |
1522 | return r; | |
1523 | ||
58ab31d5 | 1524 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1525 | if (r < 0) |
1526 | return r; | |
1527 | ||
1528 | qdcount = 1; | |
1529 | ||
7778dfff DM |
1530 | if (dns_key_is_shared(t->key)) |
1531 | add_known_answers = true; | |
1532 | ||
0d5ee47d DR |
1533 | if (t->key->type == DNS_TYPE_ANY) { |
1534 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1535 | if (r < 0) | |
1536 | return r; | |
1537 | ||
1538 | r = set_put(keys, t->key); | |
1539 | if (r < 0) | |
1540 | return r; | |
1541 | } | |
1542 | ||
0afa57e2 DM |
1543 | /* |
1544 | * For mDNS, we want to coalesce as many open queries in pending transactions into one single | |
1545 | * query packet on the wire as possible. To achieve that, we iterate through all pending transactions | |
1546 | * in our current scope, and see whether their timing contraints allow them to be sent. | |
1547 | */ | |
1548 | ||
1549 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1550 | ||
1551 | LIST_FOREACH(transactions_by_scope, other, t->scope->transactions) { | |
1552 | ||
1553 | /* Skip ourselves */ | |
1554 | if (other == t) | |
1555 | continue; | |
1556 | ||
1557 | if (other->state != DNS_TRANSACTION_PENDING) | |
1558 | continue; | |
1559 | ||
1560 | if (other->next_attempt_after > ts) | |
1561 | continue; | |
1562 | ||
1563 | if (qdcount >= UINT16_MAX) | |
1564 | break; | |
1565 | ||
58ab31d5 | 1566 | r = dns_packet_append_key(p, other->key, 0, NULL); |
0afa57e2 DM |
1567 | |
1568 | /* | |
1569 | * If we can't stuff more questions into the packet, just give up. | |
1570 | * One of the 'other' transactions will fire later and take care of the rest. | |
1571 | */ | |
1572 | if (r == -EMSGSIZE) | |
1573 | break; | |
1574 | ||
1575 | if (r < 0) | |
1576 | return r; | |
1577 | ||
c842ff24 | 1578 | r = dns_transaction_prepare(other, ts); |
0afa57e2 DM |
1579 | if (r <= 0) |
1580 | continue; | |
1581 | ||
1582 | ts += transaction_get_resend_timeout(other); | |
1583 | ||
1584 | r = sd_event_add_time( | |
1585 | other->scope->manager->event, | |
1586 | &other->timeout_event_source, | |
1587 | clock_boottime_or_monotonic(), | |
1588 | ts, 0, | |
1589 | on_transaction_timeout, other); | |
1590 | if (r < 0) | |
1591 | return r; | |
1592 | ||
ff537038 | 1593 | (void) sd_event_source_set_description(other->timeout_event_source, "dns-transaction-timeout"); |
aa4a9deb | 1594 | |
0afa57e2 DM |
1595 | other->state = DNS_TRANSACTION_PENDING; |
1596 | other->next_attempt_after = ts; | |
1597 | ||
313cefa1 | 1598 | qdcount++; |
7778dfff DM |
1599 | |
1600 | if (dns_key_is_shared(other->key)) | |
1601 | add_known_answers = true; | |
0d5ee47d DR |
1602 | |
1603 | if (other->key->type == DNS_TYPE_ANY) { | |
1604 | r = set_ensure_allocated(&keys, &dns_resource_key_hash_ops); | |
1605 | if (r < 0) | |
1606 | return r; | |
1607 | ||
1608 | r = set_put(keys, other->key); | |
1609 | if (r < 0) | |
1610 | return r; | |
1611 | } | |
0afa57e2 DM |
1612 | } |
1613 | ||
1614 | DNS_PACKET_HEADER(p)->qdcount = htobe16(qdcount); | |
0afa57e2 | 1615 | |
7778dfff DM |
1616 | /* Append known answer section if we're asking for any shared record */ |
1617 | if (add_known_answers) { | |
1618 | r = dns_cache_export_shared_to_packet(&t->scope->cache, p); | |
1619 | if (r < 0) | |
1620 | return r; | |
1621 | } | |
1622 | ||
0d5ee47d DR |
1623 | SET_FOREACH(tkey, keys, i) { |
1624 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; | |
1625 | bool tentative; | |
1626 | ||
1627 | r = dns_zone_lookup(&t->scope->zone, tkey, t->scope->link->ifindex, &answer, NULL, &tentative); | |
1628 | if (r < 0) | |
1629 | return r; | |
1630 | ||
1631 | r = dns_packet_append_answer(p, answer); | |
1632 | if (r < 0) | |
1633 | return r; | |
1634 | ||
1635 | nscount += dns_answer_size(answer); | |
1636 | } | |
1637 | DNS_PACKET_HEADER(p)->nscount = htobe16(nscount); | |
1638 | ||
1cc6c93a | 1639 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1640 | |
1641 | return 0; | |
1642 | } | |
1643 | ||
1644 | static int dns_transaction_make_packet(DnsTransaction *t) { | |
1645 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1646 | int r; | |
1647 | ||
1648 | assert(t); | |
1649 | ||
1650 | if (t->scope->protocol == DNS_PROTOCOL_MDNS) | |
1651 | return dns_transaction_make_packet_mdns(t); | |
1652 | ||
1653 | if (t->sent) | |
1654 | return 0; | |
1655 | ||
b652d4a2 | 1656 | r = dns_packet_new_query(&p, t->scope->protocol, 0, t->scope->dnssec_mode != DNSSEC_NO); |
0afa57e2 DM |
1657 | if (r < 0) |
1658 | return r; | |
1659 | ||
58ab31d5 | 1660 | r = dns_packet_append_key(p, t->key, 0, NULL); |
0afa57e2 DM |
1661 | if (r < 0) |
1662 | return r; | |
1663 | ||
1664 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); | |
1665 | DNS_PACKET_HEADER(p)->id = t->id; | |
1666 | ||
1cc6c93a | 1667 | t->sent = TAKE_PTR(p); |
0afa57e2 DM |
1668 | |
1669 | return 0; | |
1670 | } | |
1671 | ||
1effe965 DM |
1672 | int dns_transaction_go(DnsTransaction *t) { |
1673 | usec_t ts; | |
1674 | int r; | |
202b76ae | 1675 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
1effe965 DM |
1676 | |
1677 | assert(t); | |
1678 | ||
5278bbfe LP |
1679 | /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished |
1680 | * now. */ | |
1681 | ||
1effe965 | 1682 | assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); |
547973de | 1683 | |
c842ff24 | 1684 | r = dns_transaction_prepare(t, ts); |
1effe965 DM |
1685 | if (r <= 0) |
1686 | return r; | |
1687 | ||
202b76ae | 1688 | log_debug("Transaction %" PRIu16 " for <%s> scope %s on %s/%s.", |
a5784c49 | 1689 | t->id, |
202b76ae | 1690 | dns_resource_key_to_string(t->key, key_str, sizeof key_str), |
a5784c49 LP |
1691 | dns_protocol_to_string(t->scope->protocol), |
1692 | t->scope->link ? t->scope->link->name : "*", | |
202b76ae | 1693 | af_to_name_short(t->scope->family)); |
1effe965 | 1694 | |
ef7ce6df | 1695 | if (!t->initial_jitter_scheduled && |
3742095b | 1696 | IN_SET(t->scope->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { |
ea12bcc7 | 1697 | usec_t jitter, accuracy; |
6e068472 LP |
1698 | |
1699 | /* RFC 4795 Section 2.7 suggests all queries should be | |
1700 | * delayed by a random time from 0 to JITTER_INTERVAL. */ | |
1701 | ||
ef7ce6df | 1702 | t->initial_jitter_scheduled = true; |
6e068472 LP |
1703 | |
1704 | random_bytes(&jitter, sizeof(jitter)); | |
ea12bcc7 DM |
1705 | |
1706 | switch (t->scope->protocol) { | |
519ef046 | 1707 | |
ea12bcc7 DM |
1708 | case DNS_PROTOCOL_LLMNR: |
1709 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1710 | accuracy = LLMNR_JITTER_INTERVAL_USEC; | |
1711 | break; | |
519ef046 | 1712 | |
ea12bcc7 DM |
1713 | case DNS_PROTOCOL_MDNS: |
1714 | jitter %= MDNS_JITTER_RANGE_USEC; | |
1715 | jitter += MDNS_JITTER_MIN_USEC; | |
1716 | accuracy = MDNS_JITTER_RANGE_USEC; | |
1717 | break; | |
1718 | default: | |
1719 | assert_not_reached("bad protocol"); | |
1720 | } | |
6e068472 LP |
1721 | |
1722 | r = sd_event_add_time( | |
1723 | t->scope->manager->event, | |
1724 | &t->timeout_event_source, | |
1725 | clock_boottime_or_monotonic(), | |
ea12bcc7 | 1726 | ts + jitter, accuracy, |
6e068472 LP |
1727 | on_transaction_timeout, t); |
1728 | if (r < 0) | |
1729 | return r; | |
1730 | ||
aa4a9deb LP |
1731 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1732 | ||
6e068472 | 1733 | t->n_attempts = 0; |
a9da14e1 | 1734 | t->next_attempt_after = ts; |
6e068472 LP |
1735 | t->state = DNS_TRANSACTION_PENDING; |
1736 | ||
ea12bcc7 | 1737 | log_debug("Delaying %s transaction for " USEC_FMT "us.", dns_protocol_to_string(t->scope->protocol), jitter); |
6e068472 LP |
1738 | return 0; |
1739 | } | |
1740 | ||
ec2c5e43 LP |
1741 | /* Otherwise, we need to ask the network */ |
1742 | r = dns_transaction_make_packet(t); | |
ec2c5e43 LP |
1743 | if (r < 0) |
1744 | return r; | |
1745 | ||
1746 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && | |
1c02e7ba ZJS |
1747 | (dns_name_endswith(dns_resource_key_name(t->key), "in-addr.arpa") > 0 || |
1748 | dns_name_endswith(dns_resource_key_name(t->key), "ip6.arpa") > 0)) { | |
ec2c5e43 LP |
1749 | |
1750 | /* RFC 4795, Section 2.4. says reverse lookups shall | |
1751 | * always be made via TCP on LLMNR */ | |
98767d75 | 1752 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1753 | } else { |
be808ea0 TG |
1754 | /* Try via UDP, and if that fails due to large size or lack of |
1755 | * support try via TCP */ | |
49cce12d | 1756 | r = dns_transaction_emit_udp(t); |
29ab0552 LP |
1757 | if (r == -EMSGSIZE) |
1758 | log_debug("Sending query via TCP since it is too large."); | |
dc349f5f | 1759 | else if (r == -EAGAIN) |
5d67a7ae | 1760 | log_debug("Sending query via TCP since UDP isn't supported."); |
4c701096 | 1761 | if (IN_SET(r, -EMSGSIZE, -EAGAIN)) |
98767d75 | 1762 | r = dns_transaction_emit_tcp(t); |
ec2c5e43 | 1763 | } |
be808ea0 | 1764 | |
ec2c5e43 LP |
1765 | if (r == -ESRCH) { |
1766 | /* No servers to send this to? */ | |
1767 | dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS); | |
1768 | return 0; | |
91adc4db LP |
1769 | } |
1770 | if (r == -EOPNOTSUPP) { | |
1771 | /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */ | |
1772 | dns_transaction_complete(t, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED); | |
1773 | return 0; | |
1774 | } | |
0791110f | 1775 | if (t->scope->protocol == DNS_PROTOCOL_LLMNR && ERRNO_IS_DISCONNECT(-r)) { |
e94968ba | 1776 | /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot |
0791110f LP |
1777 | * answer this request with this protocol. */ |
1778 | dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND); | |
1779 | return 0; | |
1780 | } | |
91adc4db | 1781 | if (r < 0) { |
7cc6ed7b LP |
1782 | if (t->scope->protocol != DNS_PROTOCOL_DNS) |
1783 | return r; | |
13b551ac | 1784 | |
ec2c5e43 | 1785 | /* Couldn't send? Try immediately again, with a new server */ |
519ef046 | 1786 | dns_scope_next_dns_server(t->scope); |
ec2c5e43 LP |
1787 | |
1788 | return dns_transaction_go(t); | |
1789 | } | |
1790 | ||
a9da14e1 DM |
1791 | ts += transaction_get_resend_timeout(t); |
1792 | ||
9a015429 LP |
1793 | r = sd_event_add_time( |
1794 | t->scope->manager->event, | |
1795 | &t->timeout_event_source, | |
1796 | clock_boottime_or_monotonic(), | |
a9da14e1 | 1797 | ts, 0, |
9a015429 | 1798 | on_transaction_timeout, t); |
ec2c5e43 LP |
1799 | if (r < 0) |
1800 | return r; | |
1801 | ||
aa4a9deb LP |
1802 | (void) sd_event_source_set_description(t->timeout_event_source, "dns-transaction-timeout"); |
1803 | ||
ec2c5e43 | 1804 | t->state = DNS_TRANSACTION_PENDING; |
a9da14e1 DM |
1805 | t->next_attempt_after = ts; |
1806 | ||
ec2c5e43 LP |
1807 | return 1; |
1808 | } | |
1809 | ||
f2992dc1 LP |
1810 | static int dns_transaction_find_cyclic(DnsTransaction *t, DnsTransaction *aux) { |
1811 | DnsTransaction *n; | |
1812 | Iterator i; | |
1813 | int r; | |
1814 | ||
1815 | assert(t); | |
1816 | assert(aux); | |
1817 | ||
1818 | /* Try to find cyclic dependencies between transaction objects */ | |
1819 | ||
1820 | if (t == aux) | |
1821 | return 1; | |
1822 | ||
3eb6aa00 | 1823 | SET_FOREACH(n, aux->dnssec_transactions, i) { |
f2992dc1 LP |
1824 | r = dns_transaction_find_cyclic(t, n); |
1825 | if (r != 0) | |
1826 | return r; | |
1827 | } | |
1828 | ||
3eb6aa00 | 1829 | return 0; |
f2992dc1 LP |
1830 | } |
1831 | ||
547973de LP |
1832 | static int dns_transaction_add_dnssec_transaction(DnsTransaction *t, DnsResourceKey *key, DnsTransaction **ret) { |
1833 | DnsTransaction *aux; | |
1834 | int r; | |
1835 | ||
1836 | assert(t); | |
1837 | assert(ret); | |
1838 | assert(key); | |
1839 | ||
1840 | aux = dns_scope_find_transaction(t->scope, key, true); | |
1841 | if (!aux) { | |
1842 | r = dns_transaction_new(&aux, t->scope, key); | |
1843 | if (r < 0) | |
1844 | return r; | |
1845 | } else { | |
1846 | if (set_contains(t->dnssec_transactions, aux)) { | |
1847 | *ret = aux; | |
1848 | return 0; | |
1849 | } | |
f2992dc1 LP |
1850 | |
1851 | r = dns_transaction_find_cyclic(t, aux); | |
1852 | if (r < 0) | |
1853 | return r; | |
1854 | if (r > 0) { | |
202b76ae ZJS |
1855 | char s[DNS_RESOURCE_KEY_STRING_MAX], saux[DNS_RESOURCE_KEY_STRING_MAX]; |
1856 | ||
1857 | log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16 " (%s) as dependency for %" PRIu16 " (%s).", | |
f2992dc1 | 1858 | aux->id, |
202b76ae | 1859 | dns_resource_key_to_string(t->key, s, sizeof s), |
f2992dc1 | 1860 | t->id, |
202b76ae ZJS |
1861 | dns_resource_key_to_string(aux->key, saux, sizeof saux)); |
1862 | ||
f2992dc1 LP |
1863 | return -ELOOP; |
1864 | } | |
547973de LP |
1865 | } |
1866 | ||
1867 | r = set_ensure_allocated(&t->dnssec_transactions, NULL); | |
1868 | if (r < 0) | |
1869 | goto gc; | |
1870 | ||
1871 | r = set_ensure_allocated(&aux->notify_transactions, NULL); | |
1872 | if (r < 0) | |
35aa04e9 LP |
1873 | goto gc; |
1874 | ||
1875 | r = set_ensure_allocated(&aux->notify_transactions_done, NULL); | |
1876 | if (r < 0) | |
547973de LP |
1877 | goto gc; |
1878 | ||
1879 | r = set_put(t->dnssec_transactions, aux); | |
1880 | if (r < 0) | |
1881 | goto gc; | |
1882 | ||
1883 | r = set_put(aux->notify_transactions, t); | |
1884 | if (r < 0) { | |
1885 | (void) set_remove(t->dnssec_transactions, aux); | |
1886 | goto gc; | |
1887 | } | |
1888 | ||
1889 | *ret = aux; | |
1890 | return 1; | |
1891 | ||
1892 | gc: | |
1893 | dns_transaction_gc(aux); | |
1894 | return r; | |
1895 | } | |
1896 | ||
1897 | static int dns_transaction_request_dnssec_rr(DnsTransaction *t, DnsResourceKey *key) { | |
1898 | _cleanup_(dns_answer_unrefp) DnsAnswer *a = NULL; | |
1899 | DnsTransaction *aux; | |
1900 | int r; | |
1901 | ||
1902 | assert(t); | |
1903 | assert(key); | |
1904 | ||
1905 | /* Try to get the data from the trust anchor */ | |
8e54f5d9 | 1906 | r = dns_trust_anchor_lookup_positive(&t->scope->manager->trust_anchor, key, &a); |
547973de LP |
1907 | if (r < 0) |
1908 | return r; | |
1909 | if (r > 0) { | |
1910 | r = dns_answer_extend(&t->validated_keys, a); | |
1911 | if (r < 0) | |
1912 | return r; | |
1913 | ||
1914 | return 0; | |
1915 | } | |
1916 | ||
1917 | /* This didn't work, ask for it via the network/cache then. */ | |
1918 | r = dns_transaction_add_dnssec_transaction(t, key, &aux); | |
f2992dc1 LP |
1919 | if (r == -ELOOP) /* This would result in a cyclic dependency */ |
1920 | return 0; | |
547973de LP |
1921 | if (r < 0) |
1922 | return r; | |
1923 | ||
1924 | if (aux->state == DNS_TRANSACTION_NULL) { | |
1925 | r = dns_transaction_go(aux); | |
1926 | if (r < 0) | |
1927 | return r; | |
1928 | } | |
1929 | ||
f2992dc1 | 1930 | return 1; |
547973de LP |
1931 | } |
1932 | ||
8a516214 LP |
1933 | static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction *t, const char *name) { |
1934 | int r; | |
1935 | ||
1936 | assert(t); | |
1937 | ||
c629ff58 | 1938 | /* Check whether the specified name is in the NTA |
8a516214 LP |
1939 | * database, either in the global one, or the link-local |
1940 | * one. */ | |
1941 | ||
1942 | r = dns_trust_anchor_lookup_negative(&t->scope->manager->trust_anchor, name); | |
1943 | if (r != 0) | |
1944 | return r; | |
1945 | ||
1946 | if (!t->scope->link) | |
1947 | return 0; | |
1948 | ||
1949 | return set_contains(t->scope->link->dnssec_negative_trust_anchors, name); | |
1950 | } | |
1951 | ||
105e1512 LP |
1952 | static int dns_transaction_has_unsigned_negative_answer(DnsTransaction *t) { |
1953 | int r; | |
1954 | ||
1955 | assert(t); | |
1956 | ||
1957 | /* Checks whether the answer is negative, and lacks NSEC/NSEC3 | |
1958 | * RRs to prove it */ | |
1959 | ||
1960 | r = dns_transaction_has_positive_answer(t, NULL); | |
1961 | if (r < 0) | |
1962 | return r; | |
1963 | if (r > 0) | |
1964 | return false; | |
1965 | ||
8e54f5d9 LP |
1966 | /* Is this key explicitly listed as a negative trust anchor? |
1967 | * If so, it's nothing we need to care about */ | |
1c02e7ba | 1968 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
1969 | if (r < 0) |
1970 | return r; | |
1971 | if (r > 0) | |
1972 | return false; | |
1973 | ||
105e1512 LP |
1974 | /* The answer does not contain any RRs that match to the |
1975 | * question. If so, let's see if there are any NSEC/NSEC3 RRs | |
1976 | * included. If not, the answer is unsigned. */ | |
1977 | ||
1978 | r = dns_answer_contains_nsec_or_nsec3(t->answer); | |
1979 | if (r < 0) | |
1980 | return r; | |
1981 | if (r > 0) | |
1982 | return false; | |
1983 | ||
1984 | return true; | |
1985 | } | |
1986 | ||
1987 | static int dns_transaction_is_primary_response(DnsTransaction *t, DnsResourceRecord *rr) { | |
1988 | int r; | |
1989 | ||
1990 | assert(t); | |
1991 | assert(rr); | |
1992 | ||
1993 | /* Check if the specified RR is the "primary" response, | |
1994 | * i.e. either matches the question precisely or is a | |
4cb94977 | 1995 | * CNAME/DNAME for it. */ |
105e1512 LP |
1996 | |
1997 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
1998 | if (r != 0) | |
1999 | return r; | |
2000 | ||
4cb94977 | 2001 | return dns_resource_key_match_cname_or_dname(t->key, rr->key, NULL); |
105e1512 LP |
2002 | } |
2003 | ||
92ec902a LP |
2004 | static bool dns_transaction_dnssec_supported(DnsTransaction *t) { |
2005 | assert(t); | |
2006 | ||
2007 | /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon | |
2008 | * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */ | |
2009 | ||
2010 | if (t->scope->protocol != DNS_PROTOCOL_DNS) | |
2011 | return false; | |
2012 | ||
2013 | /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well | |
2014 | * be supported, hence return true. */ | |
2015 | if (!t->server) | |
2016 | return true; | |
2017 | ||
d001e0a3 LP |
2018 | /* Note that we do not check the feature level actually used for the transaction but instead the feature level |
2019 | * the server is known to support currently, as the transaction feature level might be lower than what the | |
2020 | * server actually supports, since we might have downgraded this transaction's feature level because we got a | |
2021 | * SERVFAIL earlier and wanted to check whether downgrading fixes it. */ | |
92ec902a LP |
2022 | |
2023 | return dns_server_dnssec_supported(t->server); | |
2024 | } | |
2025 | ||
2026 | static bool dns_transaction_dnssec_supported_full(DnsTransaction *t) { | |
2027 | DnsTransaction *dt; | |
2028 | Iterator i; | |
2029 | ||
2030 | assert(t); | |
2031 | ||
2032 | /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */ | |
2033 | ||
2034 | if (!dns_transaction_dnssec_supported(t)) | |
2035 | return false; | |
2036 | ||
2037 | SET_FOREACH(dt, t->dnssec_transactions, i) | |
2038 | if (!dns_transaction_dnssec_supported(dt)) | |
2039 | return false; | |
2040 | ||
2041 | return true; | |
2042 | } | |
2043 | ||
547973de LP |
2044 | int dns_transaction_request_dnssec_keys(DnsTransaction *t) { |
2045 | DnsResourceRecord *rr; | |
105e1512 | 2046 | |
547973de LP |
2047 | int r; |
2048 | ||
2049 | assert(t); | |
2050 | ||
105e1512 LP |
2051 | /* |
2052 | * Retrieve all auxiliary RRs for the answer we got, so that | |
2053 | * we can verify signatures or prove that RRs are rightfully | |
2054 | * unsigned. Specifically: | |
2055 | * | |
2056 | * - For RRSIG we get the matching DNSKEY | |
2057 | * - For DNSKEY we get the matching DS | |
2058 | * - For unsigned SOA/NS we get the matching DS | |
b63fca62 | 2059 | * - For unsigned CNAME/DNAME/DS we get the parent SOA RR |
105e1512 | 2060 | * - For other unsigned RRs we get the matching SOA RR |
4bbc06cc LP |
2061 | * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR |
2062 | * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR | |
105e1512 LP |
2063 | * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR |
2064 | */ | |
2065 | ||
b652d4a2 | 2066 | if (t->scope->dnssec_mode == DNSSEC_NO) |
547973de | 2067 | return 0; |
92ec902a LP |
2068 | if (t->answer_source != DNS_TRANSACTION_NETWORK) |
2069 | return 0; /* We only need to validate stuff from the network */ | |
2070 | if (!dns_transaction_dnssec_supported(t)) | |
2071 | return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */ | |
b652d4a2 | 2072 | |
547973de LP |
2073 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2074 | ||
105e1512 LP |
2075 | if (dns_type_is_pseudo(rr->key->type)) |
2076 | continue; | |
2077 | ||
8e54f5d9 | 2078 | /* If this RR is in the negative trust anchor, we don't need to validate it. */ |
1c02e7ba | 2079 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2080 | if (r < 0) |
2081 | return r; | |
2082 | if (r > 0) | |
2083 | continue; | |
2084 | ||
547973de LP |
2085 | switch (rr->key->type) { |
2086 | ||
2087 | case DNS_TYPE_RRSIG: { | |
2088 | /* For each RRSIG we request the matching DNSKEY */ | |
2089 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *dnskey = NULL; | |
2090 | ||
2091 | /* If this RRSIG is about a DNSKEY RR and the | |
2092 | * signer is the same as the owner, then we | |
2093 | * already have the DNSKEY, and we don't have | |
2094 | * to look for more. */ | |
2095 | if (rr->rrsig.type_covered == DNS_TYPE_DNSKEY) { | |
1c02e7ba | 2096 | r = dns_name_equal(rr->rrsig.signer, dns_resource_key_name(rr->key)); |
547973de LP |
2097 | if (r < 0) |
2098 | return r; | |
2099 | if (r > 0) | |
2100 | continue; | |
2101 | } | |
2102 | ||
105e1512 LP |
2103 | /* If the signer is not a parent of our |
2104 | * original query, then this is about an | |
2105 | * auxiliary RRset, but not anything we asked | |
2106 | * for. In this case we aren't interested, | |
2107 | * because we don't want to request additional | |
2108 | * RRs for stuff we didn't really ask for, and | |
2109 | * also to avoid request loops, where | |
2110 | * additional RRs from one transaction result | |
2111 | * in another transaction whose additonal RRs | |
2112 | * point back to the original transaction, and | |
2113 | * we deadlock. */ | |
1c02e7ba | 2114 | r = dns_name_endswith(dns_resource_key_name(t->key), rr->rrsig.signer); |
547973de LP |
2115 | if (r < 0) |
2116 | return r; | |
2117 | if (r == 0) | |
2118 | continue; | |
2119 | ||
2120 | dnskey = dns_resource_key_new(rr->key->class, DNS_TYPE_DNSKEY, rr->rrsig.signer); | |
2121 | if (!dnskey) | |
2122 | return -ENOMEM; | |
2123 | ||
1c02e7ba ZJS |
2124 | log_debug("Requesting DNSKEY to validate transaction %" PRIu16" (%s, RRSIG with key tag: %" PRIu16 ").", |
2125 | t->id, dns_resource_key_name(rr->key), rr->rrsig.key_tag); | |
547973de LP |
2126 | r = dns_transaction_request_dnssec_rr(t, dnskey); |
2127 | if (r < 0) | |
2128 | return r; | |
2129 | break; | |
2130 | } | |
2131 | ||
2132 | case DNS_TYPE_DNSKEY: { | |
2133 | /* For each DNSKEY we request the matching DS */ | |
2134 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2135 | ||
105e1512 LP |
2136 | /* If the DNSKEY we are looking at is not for |
2137 | * zone we are interested in, nor any of its | |
2138 | * parents, we aren't interested, and don't | |
2139 | * request it. After all, we don't want to end | |
2140 | * up in request loops, and want to keep | |
2141 | * additional traffic down. */ | |
2142 | ||
1c02e7ba | 2143 | r = dns_name_endswith(dns_resource_key_name(t->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2144 | if (r < 0) |
2145 | return r; | |
2146 | if (r == 0) | |
2147 | continue; | |
2148 | ||
1c02e7ba | 2149 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
547973de LP |
2150 | if (!ds) |
2151 | return -ENOMEM; | |
2152 | ||
1c02e7ba ZJS |
2153 | log_debug("Requesting DS to validate transaction %" PRIu16" (%s, DNSKEY with key tag: %" PRIu16 ").", |
2154 | t->id, dns_resource_key_name(rr->key), dnssec_keytag(rr, false)); | |
105e1512 LP |
2155 | r = dns_transaction_request_dnssec_rr(t, ds); |
2156 | if (r < 0) | |
2157 | return r; | |
547973de | 2158 | |
105e1512 LP |
2159 | break; |
2160 | } | |
2161 | ||
105e1512 LP |
2162 | case DNS_TYPE_SOA: |
2163 | case DNS_TYPE_NS: { | |
2164 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *ds = NULL; | |
2165 | ||
2166 | /* For an unsigned SOA or NS, try to acquire | |
2167 | * the matching DS RR, as we are at a zone cut | |
2168 | * then, and whether a DS exists tells us | |
2169 | * whether the zone is signed. Do so only if | |
2170 | * this RR matches our original question, | |
2171 | * however. */ | |
2172 | ||
2173 | r = dns_resource_key_match_rr(t->key, rr, NULL); | |
2174 | if (r < 0) | |
2175 | return r; | |
6993d264 LP |
2176 | if (r == 0) { |
2177 | /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is | |
2178 | * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry? | |
2179 | * If so, we need to validate it, too. */ | |
2180 | ||
2181 | r = dns_answer_match_key(t->answer, t->key, NULL); | |
2182 | if (r < 0) | |
2183 | return r; | |
2184 | if (r > 0) /* positive reply, we won't need the SOA and hence don't need to validate | |
2185 | * it. */ | |
2186 | continue; | |
2187 | } | |
105e1512 LP |
2188 | |
2189 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2190 | if (r < 0) | |
2191 | return r; | |
2192 | if (r > 0) | |
2193 | continue; | |
2194 | ||
1c02e7ba | 2195 | ds = dns_resource_key_new(rr->key->class, DNS_TYPE_DS, dns_resource_key_name(rr->key)); |
105e1512 LP |
2196 | if (!ds) |
2197 | return -ENOMEM; | |
2198 | ||
1c02e7ba ZJS |
2199 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned SOA/NS RRset).", |
2200 | t->id, dns_resource_key_name(rr->key)); | |
547973de LP |
2201 | r = dns_transaction_request_dnssec_rr(t, ds); |
2202 | if (r < 0) | |
2203 | return r; | |
2204 | ||
2205 | break; | |
105e1512 LP |
2206 | } |
2207 | ||
b63fca62 | 2208 | case DNS_TYPE_DS: |
105e1512 LP |
2209 | case DNS_TYPE_CNAME: |
2210 | case DNS_TYPE_DNAME: { | |
2211 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2212 | const char *name; | |
2213 | ||
2214 | /* CNAMEs and DNAMEs cannot be located at a | |
2215 | * zone apex, hence ask for the parent SOA for | |
2216 | * unsigned CNAME/DNAME RRs, maybe that's the | |
2217 | * apex. But do all that only if this is | |
2218 | * actually a response to our original | |
b63fca62 LP |
2219 | * question. |
2220 | * | |
2221 | * Similar for DS RRs, which are signed when | |
2222 | * the parent SOA is signed. */ | |
105e1512 LP |
2223 | |
2224 | r = dns_transaction_is_primary_response(t, rr); | |
2225 | if (r < 0) | |
2226 | return r; | |
2227 | if (r == 0) | |
2228 | continue; | |
2229 | ||
2230 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2231 | if (r < 0) | |
2232 | return r; | |
2233 | if (r > 0) | |
2234 | continue; | |
2235 | ||
43e6779a LP |
2236 | r = dns_answer_has_dname_for_cname(t->answer, rr); |
2237 | if (r < 0) | |
2238 | return r; | |
2239 | if (r > 0) | |
2240 | continue; | |
2241 | ||
1c02e7ba | 2242 | name = dns_resource_key_name(rr->key); |
105e1512 LP |
2243 | r = dns_name_parent(&name); |
2244 | if (r < 0) | |
2245 | return r; | |
2246 | if (r == 0) | |
2247 | continue; | |
2248 | ||
2249 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, name); | |
2250 | if (!soa) | |
2251 | return -ENOMEM; | |
2252 | ||
1c02e7ba ZJS |
2253 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned CNAME/DNAME/DS RRset).", |
2254 | t->id, dns_resource_key_name(rr->key)); | |
105e1512 LP |
2255 | r = dns_transaction_request_dnssec_rr(t, soa); |
2256 | if (r < 0) | |
2257 | return r; | |
2258 | ||
2259 | break; | |
2260 | } | |
2261 | ||
2262 | default: { | |
2263 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2264 | ||
b63fca62 LP |
2265 | /* For other unsigned RRsets (including |
2266 | * NSEC/NSEC3!), look for proof the zone is | |
2267 | * unsigned, by requesting the SOA RR of the | |
2268 | * zone. However, do so only if they are | |
2269 | * directly relevant to our original | |
105e1512 LP |
2270 | * question. */ |
2271 | ||
2272 | r = dns_transaction_is_primary_response(t, rr); | |
2273 | if (r < 0) | |
2274 | return r; | |
2275 | if (r == 0) | |
2276 | continue; | |
2277 | ||
2278 | r = dnssec_has_rrsig(t->answer, rr->key); | |
2279 | if (r < 0) | |
2280 | return r; | |
2281 | if (r > 0) | |
2282 | continue; | |
2283 | ||
1c02e7ba | 2284 | soa = dns_resource_key_new(rr->key->class, DNS_TYPE_SOA, dns_resource_key_name(rr->key)); |
105e1512 LP |
2285 | if (!soa) |
2286 | return -ENOMEM; | |
2287 | ||
1c02e7ba ZJS |
2288 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned non-SOA/NS RRset <%s>).", |
2289 | t->id, dns_resource_key_name(rr->key), dns_resource_record_to_string(rr)); | |
105e1512 LP |
2290 | r = dns_transaction_request_dnssec_rr(t, soa); |
2291 | if (r < 0) | |
2292 | return r; | |
2293 | break; | |
547973de LP |
2294 | }} |
2295 | } | |
2296 | ||
105e1512 LP |
2297 | /* Above, we requested everything necessary to validate what |
2298 | * we got. Now, let's request what we need to validate what we | |
2299 | * didn't get... */ | |
2300 | ||
2301 | r = dns_transaction_has_unsigned_negative_answer(t); | |
2302 | if (r < 0) | |
2303 | return r; | |
2304 | if (r > 0) { | |
2305 | const char *name; | |
4bbc06cc | 2306 | uint16_t type = 0; |
105e1512 | 2307 | |
1c02e7ba | 2308 | name = dns_resource_key_name(t->key); |
105e1512 | 2309 | |
4bbc06cc LP |
2310 | /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this |
2311 | * could also be used as indication that we are not at a zone apex, but in real world setups there are | |
2312 | * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even | |
2313 | * though they have further children. If this was a DS request, then it's signed when the parent zone | |
2314 | * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR, | |
2315 | * to see if that is signed. */ | |
105e1512 | 2316 | |
4bbc06cc | 2317 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2318 | r = dns_name_parent(&name); |
4bbc06cc LP |
2319 | if (r > 0) { |
2320 | type = DNS_TYPE_SOA; | |
2321 | log_debug("Requesting parent SOA to validate transaction %" PRIu16 " (%s, unsigned empty DS response).", | |
1c02e7ba | 2322 | t->id, dns_resource_key_name(t->key)); |
4bbc06cc | 2323 | } else |
105e1512 | 2324 | name = NULL; |
4bbc06cc LP |
2325 | |
2326 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) { | |
2327 | ||
2328 | type = DNS_TYPE_DS; | |
2329 | log_debug("Requesting DS to validate transaction %" PRIu16 " (%s, unsigned empty SOA/NS response).", | |
2330 | t->id, dns_resource_key_name(t->key)); | |
2331 | ||
2332 | } else { | |
2333 | type = DNS_TYPE_SOA; | |
1c02e7ba ZJS |
2334 | log_debug("Requesting SOA to validate transaction %" PRIu16 " (%s, unsigned empty non-SOA/NS/DS response).", |
2335 | t->id, dns_resource_key_name(t->key)); | |
4bbc06cc | 2336 | } |
105e1512 LP |
2337 | |
2338 | if (name) { | |
2339 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *soa = NULL; | |
2340 | ||
4bbc06cc | 2341 | soa = dns_resource_key_new(t->key->class, type, name); |
105e1512 LP |
2342 | if (!soa) |
2343 | return -ENOMEM; | |
2344 | ||
2345 | r = dns_transaction_request_dnssec_rr(t, soa); | |
2346 | if (r < 0) | |
2347 | return r; | |
2348 | } | |
2349 | } | |
2350 | ||
2351 | return dns_transaction_dnssec_is_live(t); | |
547973de LP |
2352 | } |
2353 | ||
2354 | void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source) { | |
547973de | 2355 | assert(t); |
547973de LP |
2356 | assert(source); |
2357 | ||
942eb2e7 LP |
2358 | /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING, |
2359 | we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If | |
2360 | the state is VALIDATING however, we should check if we are complete now. */ | |
105e1512 | 2361 | |
942eb2e7 LP |
2362 | if (t->state == DNS_TRANSACTION_VALIDATING) |
2363 | dns_transaction_process_dnssec(t); | |
547973de LP |
2364 | } |
2365 | ||
105e1512 LP |
2366 | static int dns_transaction_validate_dnskey_by_ds(DnsTransaction *t) { |
2367 | DnsResourceRecord *rr; | |
2368 | int ifindex, r; | |
2369 | ||
2370 | assert(t); | |
2371 | ||
2372 | /* Add all DNSKEY RRs from the answer that are validated by DS | |
2373 | * RRs from the list of validated keys to the list of | |
2374 | * validated keys. */ | |
2375 | ||
2376 | DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, t->answer) { | |
2377 | ||
96bb7673 | 2378 | r = dnssec_verify_dnskey_by_ds_search(rr, t->validated_keys); |
105e1512 LP |
2379 | if (r < 0) |
2380 | return r; | |
2381 | if (r == 0) | |
2382 | continue; | |
2383 | ||
2384 | /* If so, the DNSKEY is validated too. */ | |
2385 | r = dns_answer_add_extend(&t->validated_keys, rr, ifindex, DNS_ANSWER_AUTHENTICATED); | |
2386 | if (r < 0) | |
2387 | return r; | |
2388 | } | |
2389 | ||
2390 | return 0; | |
2391 | } | |
2392 | ||
2393 | static int dns_transaction_requires_rrsig(DnsTransaction *t, DnsResourceRecord *rr) { | |
56352fe9 LP |
2394 | int r; |
2395 | ||
2396 | assert(t); | |
2397 | assert(rr); | |
2398 | ||
105e1512 LP |
2399 | /* Checks if the RR we are looking for must be signed with an |
2400 | * RRSIG. This is used for positive responses. */ | |
24a5b982 | 2401 | |
b652d4a2 | 2402 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2403 | return false; |
56352fe9 | 2404 | |
105e1512 LP |
2405 | if (dns_type_is_pseudo(rr->key->type)) |
2406 | return -EINVAL; | |
56352fe9 | 2407 | |
1c02e7ba | 2408 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2409 | if (r < 0) |
2410 | return r; | |
2411 | if (r > 0) | |
2412 | return false; | |
2413 | ||
105e1512 | 2414 | switch (rr->key->type) { |
56352fe9 | 2415 | |
105e1512 LP |
2416 | case DNS_TYPE_RRSIG: |
2417 | /* RRSIGs are the signatures themselves, they need no signing. */ | |
2418 | return false; | |
2419 | ||
2420 | case DNS_TYPE_SOA: | |
2421 | case DNS_TYPE_NS: { | |
2422 | DnsTransaction *dt; | |
2423 | Iterator i; | |
2424 | ||
b63fca62 | 2425 | /* For SOA or NS RRs we look for a matching DS transaction */ |
105e1512 LP |
2426 | |
2427 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2428 | ||
2429 | if (dt->key->class != rr->key->class) | |
2430 | continue; | |
2431 | if (dt->key->type != DNS_TYPE_DS) | |
2432 | continue; | |
2433 | ||
1c02e7ba | 2434 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2435 | if (r < 0) |
2436 | return r; | |
2437 | if (r == 0) | |
2438 | continue; | |
2439 | ||
2440 | /* We found a DS transactions for the SOA/NS | |
2441 | * RRs we are looking at. If it discovered signed DS | |
2442 | * RRs, then we need to be signed, too. */ | |
2443 | ||
097a2517 TA |
2444 | if (!dt->answer_authenticated) |
2445 | return false; | |
105e1512 | 2446 | |
097a2517 | 2447 | return dns_answer_match_key(dt->answer, dt->key, NULL); |
105e1512 LP |
2448 | } |
2449 | ||
2450 | /* We found nothing that proves this is safe to leave | |
2451 | * this unauthenticated, hence ask inist on | |
2452 | * authentication. */ | |
2453 | return true; | |
2454 | } | |
2455 | ||
b63fca62 | 2456 | case DNS_TYPE_DS: |
105e1512 LP |
2457 | case DNS_TYPE_CNAME: |
2458 | case DNS_TYPE_DNAME: { | |
2459 | const char *parent = NULL; | |
2460 | DnsTransaction *dt; | |
2461 | Iterator i; | |
2462 | ||
b63fca62 LP |
2463 | /* |
2464 | * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA. | |
2465 | * | |
2466 | * DS RRs are signed if the parent is signed, hence also look at the parent SOA | |
2467 | */ | |
105e1512 LP |
2468 | |
2469 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2470 | ||
2471 | if (dt->key->class != rr->key->class) | |
2472 | continue; | |
2473 | if (dt->key->type != DNS_TYPE_SOA) | |
2474 | continue; | |
2475 | ||
2476 | if (!parent) { | |
1c02e7ba | 2477 | parent = dns_resource_key_name(rr->key); |
105e1512 LP |
2478 | r = dns_name_parent(&parent); |
2479 | if (r < 0) | |
2480 | return r; | |
2481 | if (r == 0) { | |
b63fca62 LP |
2482 | if (rr->key->type == DNS_TYPE_DS) |
2483 | return true; | |
2484 | ||
105e1512 LP |
2485 | /* A CNAME/DNAME without a parent? That's sooo weird. */ |
2486 | log_debug("Transaction %" PRIu16 " claims CNAME/DNAME at root. Refusing.", t->id); | |
2487 | return -EBADMSG; | |
2488 | } | |
2489 | } | |
2490 | ||
1c02e7ba | 2491 | r = dns_name_equal(dns_resource_key_name(dt->key), parent); |
105e1512 LP |
2492 | if (r < 0) |
2493 | return r; | |
2494 | if (r == 0) | |
2495 | continue; | |
2496 | ||
2497 | return t->answer_authenticated; | |
2498 | } | |
2499 | ||
2500 | return true; | |
2501 | } | |
2502 | ||
2503 | default: { | |
2504 | DnsTransaction *dt; | |
2505 | Iterator i; | |
2506 | ||
b63fca62 | 2507 | /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */ |
105e1512 LP |
2508 | |
2509 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2510 | ||
2511 | if (dt->key->class != rr->key->class) | |
2512 | continue; | |
2513 | if (dt->key->type != DNS_TYPE_SOA) | |
2514 | continue; | |
2515 | ||
1c02e7ba | 2516 | r = dns_name_equal(dns_resource_key_name(dt->key), dns_resource_key_name(rr->key)); |
105e1512 LP |
2517 | if (r < 0) |
2518 | return r; | |
2519 | if (r == 0) | |
2520 | continue; | |
2521 | ||
2522 | /* We found the transaction that was supposed to find | |
2523 | * the SOA RR for us. It was successful, but found no | |
2524 | * RR for us. This means we are not at a zone cut. In | |
2525 | * this case, we require authentication if the SOA | |
2526 | * lookup was authenticated too. */ | |
2527 | return t->answer_authenticated; | |
2528 | } | |
2529 | ||
2530 | return true; | |
2531 | }} | |
56352fe9 LP |
2532 | } |
2533 | ||
d33b6cf3 LP |
2534 | static int dns_transaction_in_private_tld(DnsTransaction *t, const DnsResourceKey *key) { |
2535 | DnsTransaction *dt; | |
2536 | const char *tld; | |
2537 | Iterator i; | |
2538 | int r; | |
2539 | ||
2540 | /* If DNSSEC downgrade mode is on, checks whether the | |
2541 | * specified RR is one level below a TLD we have proven not to | |
2542 | * exist. In such a case we assume that this is a private | |
2543 | * domain, and permit it. | |
2544 | * | |
2545 | * This detects cases like the Fritz!Box router networks. Each | |
2546 | * Fritz!Box router serves a private "fritz.box" zone, in the | |
2547 | * non-existing TLD "box". Requests for the "fritz.box" domain | |
2548 | * are served by the router itself, while requests for the | |
2549 | * "box" domain will result in NXDOMAIN. | |
2550 | * | |
2551 | * Note that this logic is unable to detect cases where a | |
2552 | * router serves a private DNS zone directly under | |
2553 | * non-existing TLD. In such a case we cannot detect whether | |
2554 | * the TLD is supposed to exist or not, as all requests we | |
2555 | * make for it will be answered by the router's zone, and not | |
2556 | * by the root zone. */ | |
2557 | ||
2558 | assert(t); | |
2559 | ||
2560 | if (t->scope->dnssec_mode != DNSSEC_ALLOW_DOWNGRADE) | |
2561 | return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */ | |
2562 | ||
1c02e7ba | 2563 | tld = dns_resource_key_name(key); |
d33b6cf3 LP |
2564 | r = dns_name_parent(&tld); |
2565 | if (r < 0) | |
2566 | return r; | |
2567 | if (r == 0) | |
2568 | return false; /* Already the root domain */ | |
2569 | ||
2570 | if (!dns_name_is_single_label(tld)) | |
2571 | return false; | |
2572 | ||
2573 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2574 | ||
2575 | if (dt->key->class != key->class) | |
2576 | continue; | |
2577 | ||
1c02e7ba | 2578 | r = dns_name_equal(dns_resource_key_name(dt->key), tld); |
d33b6cf3 LP |
2579 | if (r < 0) |
2580 | return r; | |
2581 | if (r == 0) | |
2582 | continue; | |
2583 | ||
2584 | /* We found an auxiliary lookup we did for the TLD. If | |
2585 | * that returned with NXDOMAIN, we know the TLD didn't | |
2586 | * exist, and hence this might be a private zone. */ | |
2587 | ||
2588 | return dt->answer_rcode == DNS_RCODE_NXDOMAIN; | |
2589 | } | |
2590 | ||
2591 | return false; | |
2592 | } | |
2593 | ||
105e1512 | 2594 | static int dns_transaction_requires_nsec(DnsTransaction *t) { |
4bbc06cc | 2595 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
105e1512 LP |
2596 | DnsTransaction *dt; |
2597 | const char *name; | |
4bbc06cc | 2598 | uint16_t type = 0; |
105e1512 LP |
2599 | Iterator i; |
2600 | int r; | |
56352fe9 LP |
2601 | |
2602 | assert(t); | |
2603 | ||
105e1512 LP |
2604 | /* Checks if we need to insist on NSEC/NSEC3 RRs for proving |
2605 | * this negative reply */ | |
56352fe9 | 2606 | |
b652d4a2 | 2607 | if (t->scope->dnssec_mode == DNSSEC_NO) |
105e1512 | 2608 | return false; |
56352fe9 | 2609 | |
105e1512 LP |
2610 | if (dns_type_is_pseudo(t->key->type)) |
2611 | return -EINVAL; | |
2612 | ||
1c02e7ba | 2613 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(t->key)); |
8e54f5d9 LP |
2614 | if (r < 0) |
2615 | return r; | |
2616 | if (r > 0) | |
2617 | return false; | |
2618 | ||
d33b6cf3 LP |
2619 | r = dns_transaction_in_private_tld(t, t->key); |
2620 | if (r < 0) | |
2621 | return r; | |
2622 | if (r > 0) { | |
2623 | /* The lookup is from a TLD that is proven not to | |
2624 | * exist, and we are in downgrade mode, hence ignore | |
13e785f7 | 2625 | * that fact that we didn't get any NSEC RRs. */ |
d33b6cf3 | 2626 | |
202b76ae ZJS |
2627 | log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.", |
2628 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
d33b6cf3 LP |
2629 | return false; |
2630 | } | |
2631 | ||
1c02e7ba | 2632 | name = dns_resource_key_name(t->key); |
105e1512 | 2633 | |
4bbc06cc | 2634 | if (t->key->type == DNS_TYPE_DS) { |
105e1512 | 2635 | |
4bbc06cc LP |
2636 | /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed, |
2637 | * hence check the parent SOA in this case. */ | |
105e1512 LP |
2638 | |
2639 | r = dns_name_parent(&name); | |
56352fe9 LP |
2640 | if (r < 0) |
2641 | return r; | |
2642 | if (r == 0) | |
105e1512 | 2643 | return true; |
4bbc06cc LP |
2644 | |
2645 | type = DNS_TYPE_SOA; | |
2646 | ||
2647 | } else if (IN_SET(t->key->type, DNS_TYPE_SOA, DNS_TYPE_NS)) | |
2648 | /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */ | |
2649 | type = DNS_TYPE_DS; | |
2650 | else | |
2651 | /* For all other negative replies, check for the SOA lookup */ | |
2652 | type = DNS_TYPE_SOA; | |
105e1512 LP |
2653 | |
2654 | /* For all other RRs we check the SOA on the same level to see | |
2655 | * if it's signed. */ | |
2656 | ||
2657 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2658 | ||
2659 | if (dt->key->class != t->key->class) | |
2660 | continue; | |
4bbc06cc | 2661 | if (dt->key->type != type) |
56352fe9 LP |
2662 | continue; |
2663 | ||
1c02e7ba | 2664 | r = dns_name_equal(dns_resource_key_name(dt->key), name); |
56352fe9 LP |
2665 | if (r < 0) |
2666 | return r; | |
105e1512 LP |
2667 | if (r == 0) |
2668 | continue; | |
2669 | ||
2670 | return dt->answer_authenticated; | |
56352fe9 LP |
2671 | } |
2672 | ||
105e1512 LP |
2673 | /* If in doubt, require NSEC/NSEC3 */ |
2674 | return true; | |
56352fe9 LP |
2675 | } |
2676 | ||
94aa7071 LP |
2677 | static int dns_transaction_dnskey_authenticated(DnsTransaction *t, DnsResourceRecord *rr) { |
2678 | DnsResourceRecord *rrsig; | |
2679 | bool found = false; | |
2680 | int r; | |
2681 | ||
2682 | /* Checks whether any of the DNSKEYs used for the RRSIGs for | |
2683 | * the specified RRset is authenticated (i.e. has a matching | |
2684 | * DS RR). */ | |
2685 | ||
1c02e7ba | 2686 | r = dns_transaction_negative_trust_anchor_lookup(t, dns_resource_key_name(rr->key)); |
8e54f5d9 LP |
2687 | if (r < 0) |
2688 | return r; | |
2689 | if (r > 0) | |
2690 | return false; | |
2691 | ||
94aa7071 LP |
2692 | DNS_ANSWER_FOREACH(rrsig, t->answer) { |
2693 | DnsTransaction *dt; | |
2694 | Iterator i; | |
2695 | ||
2696 | r = dnssec_key_match_rrsig(rr->key, rrsig); | |
2697 | if (r < 0) | |
2698 | return r; | |
2699 | if (r == 0) | |
2700 | continue; | |
2701 | ||
2702 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2703 | ||
2704 | if (dt->key->class != rr->key->class) | |
2705 | continue; | |
2706 | ||
2707 | if (dt->key->type == DNS_TYPE_DNSKEY) { | |
2708 | ||
1c02e7ba | 2709 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2710 | if (r < 0) |
2711 | return r; | |
2712 | if (r == 0) | |
2713 | continue; | |
2714 | ||
2715 | /* OK, we found an auxiliary DNSKEY | |
2716 | * lookup. If that lookup is | |
2717 | * authenticated, report this. */ | |
2718 | ||
2719 | if (dt->answer_authenticated) | |
2720 | return true; | |
2721 | ||
2722 | found = true; | |
2723 | ||
2724 | } else if (dt->key->type == DNS_TYPE_DS) { | |
2725 | ||
1c02e7ba | 2726 | r = dns_name_equal(dns_resource_key_name(dt->key), rrsig->rrsig.signer); |
94aa7071 LP |
2727 | if (r < 0) |
2728 | return r; | |
2729 | if (r == 0) | |
2730 | continue; | |
2731 | ||
2732 | /* OK, we found an auxiliary DS | |
2733 | * lookup. If that lookup is | |
2734 | * authenticated and non-zero, we | |
2735 | * won! */ | |
2736 | ||
2737 | if (!dt->answer_authenticated) | |
2738 | return false; | |
2739 | ||
2740 | return dns_answer_match_key(dt->answer, dt->key, NULL); | |
2741 | } | |
2742 | } | |
2743 | } | |
2744 | ||
2745 | return found ? false : -ENXIO; | |
2746 | } | |
2747 | ||
b652d4a2 LP |
2748 | static int dns_transaction_known_signed(DnsTransaction *t, DnsResourceRecord *rr) { |
2749 | assert(t); | |
2750 | assert(rr); | |
2751 | ||
2752 | /* We know that the root domain is signed, hence if it appears | |
2753 | * not to be signed, there's a problem with the DNS server */ | |
2754 | ||
2755 | return rr->key->class == DNS_CLASS_IN && | |
1c02e7ba | 2756 | dns_name_is_root(dns_resource_key_name(rr->key)); |
b652d4a2 LP |
2757 | } |
2758 | ||
0f87f3e8 LP |
2759 | static int dns_transaction_check_revoked_trust_anchors(DnsTransaction *t) { |
2760 | DnsResourceRecord *rr; | |
2761 | int r; | |
2762 | ||
2763 | assert(t); | |
2764 | ||
2765 | /* Maybe warn the user that we encountered a revoked DNSKEY | |
2766 | * for a key from our trust anchor. Note that we don't care | |
2767 | * whether the DNSKEY can be authenticated or not. It's | |
2768 | * sufficient if it is self-signed. */ | |
2769 | ||
2770 | DNS_ANSWER_FOREACH(rr, t->answer) { | |
d424da2a | 2771 | r = dns_trust_anchor_check_revoked(&t->scope->manager->trust_anchor, rr, t->answer); |
0f87f3e8 LP |
2772 | if (r < 0) |
2773 | return r; | |
2774 | } | |
2775 | ||
2776 | return 0; | |
2777 | } | |
2778 | ||
c9c72065 LP |
2779 | static int dns_transaction_invalidate_revoked_keys(DnsTransaction *t) { |
2780 | bool changed; | |
2781 | int r; | |
2782 | ||
2783 | assert(t); | |
2784 | ||
2785 | /* Removes all DNSKEY/DS objects from t->validated_keys that | |
2786 | * our trust anchors database considers revoked. */ | |
2787 | ||
2788 | do { | |
2789 | DnsResourceRecord *rr; | |
2790 | ||
2791 | changed = false; | |
2792 | ||
2793 | DNS_ANSWER_FOREACH(rr, t->validated_keys) { | |
2794 | r = dns_trust_anchor_is_revoked(&t->scope->manager->trust_anchor, rr); | |
2795 | if (r < 0) | |
2796 | return r; | |
2797 | if (r > 0) { | |
2798 | r = dns_answer_remove_by_rr(&t->validated_keys, rr); | |
2799 | if (r < 0) | |
2800 | return r; | |
2801 | ||
2802 | assert(r > 0); | |
2803 | changed = true; | |
2804 | break; | |
2805 | } | |
2806 | } | |
2807 | } while (changed); | |
2808 | ||
2809 | return 0; | |
2810 | } | |
2811 | ||
942eb2e7 LP |
2812 | static int dns_transaction_copy_validated(DnsTransaction *t) { |
2813 | DnsTransaction *dt; | |
2814 | Iterator i; | |
2815 | int r; | |
2816 | ||
2817 | assert(t); | |
2818 | ||
2819 | /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */ | |
2820 | ||
2821 | SET_FOREACH(dt, t->dnssec_transactions, i) { | |
2822 | ||
2823 | if (DNS_TRANSACTION_IS_LIVE(dt->state)) | |
2824 | continue; | |
2825 | ||
2826 | if (!dt->answer_authenticated) | |
2827 | continue; | |
2828 | ||
2829 | r = dns_answer_extend(&t->validated_keys, dt->answer); | |
2830 | if (r < 0) | |
2831 | return r; | |
2832 | } | |
2833 | ||
2834 | return 0; | |
2835 | } | |
2836 | ||
c690b20a ZJS |
2837 | typedef enum { |
2838 | DNSSEC_PHASE_DNSKEY, /* Phase #1, only validate DNSKEYs */ | |
2839 | DNSSEC_PHASE_NSEC, /* Phase #2, only validate NSEC+NSEC3 */ | |
2840 | DNSSEC_PHASE_ALL, /* Phase #3, validate everything else */ | |
2841 | } Phase; | |
2842 | ||
2843 | static int dnssec_validate_records( | |
2844 | DnsTransaction *t, | |
2845 | Phase phase, | |
2846 | bool *have_nsec, | |
2847 | DnsAnswer **validated) { | |
2848 | ||
547973de | 2849 | DnsResourceRecord *rr; |
56352fe9 | 2850 | int r; |
547973de | 2851 | |
c690b20a | 2852 | /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */ |
547973de | 2853 | |
c690b20a ZJS |
2854 | DNS_ANSWER_FOREACH(rr, t->answer) { |
2855 | DnsResourceRecord *rrsig = NULL; | |
2856 | DnssecResult result; | |
547973de | 2857 | |
c690b20a ZJS |
2858 | switch (rr->key->type) { |
2859 | case DNS_TYPE_RRSIG: | |
2860 | continue; | |
547973de | 2861 | |
c690b20a ZJS |
2862 | case DNS_TYPE_DNSKEY: |
2863 | /* We validate DNSKEYs only in the DNSKEY and ALL phases */ | |
2864 | if (phase == DNSSEC_PHASE_NSEC) | |
2865 | continue; | |
2866 | break; | |
547973de | 2867 | |
c690b20a ZJS |
2868 | case DNS_TYPE_NSEC: |
2869 | case DNS_TYPE_NSEC3: | |
2870 | *have_nsec = true; | |
547973de | 2871 | |
c690b20a ZJS |
2872 | /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */ |
2873 | if (phase == DNSSEC_PHASE_DNSKEY) | |
2874 | continue; | |
2875 | break; | |
105e1512 | 2876 | |
c690b20a ZJS |
2877 | default: |
2878 | /* We validate all other RRs only in the ALL phases */ | |
2879 | if (phase != DNSSEC_PHASE_ALL) | |
2880 | continue; | |
2881 | } | |
b652d4a2 | 2882 | |
c690b20a ZJS |
2883 | r = dnssec_verify_rrset_search(t->answer, rr->key, t->validated_keys, USEC_INFINITY, &result, &rrsig); |
2884 | if (r < 0) | |
2885 | return r; | |
547973de | 2886 | |
c690b20a | 2887 | log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr)), dnssec_result_to_string(result)); |
0f87f3e8 | 2888 | |
c690b20a | 2889 | if (result == DNSSEC_VALIDATED) { |
942eb2e7 | 2890 | |
c690b20a ZJS |
2891 | if (rr->key->type == DNS_TYPE_DNSKEY) { |
2892 | /* If we just validated a DNSKEY RRset, then let's add these keys to | |
2893 | * the set of validated keys for this transaction. */ | |
547973de | 2894 | |
c690b20a ZJS |
2895 | r = dns_answer_copy_by_key(&t->validated_keys, t->answer, rr->key, DNS_ANSWER_AUTHENTICATED); |
2896 | if (r < 0) | |
2897 | return r; | |
c9c72065 | 2898 | |
c690b20a ZJS |
2899 | /* Some of the DNSKEYs we just added might already have been revoked, |
2900 | * remove them again in that case. */ | |
2901 | r = dns_transaction_invalidate_revoked_keys(t); | |
2902 | if (r < 0) | |
2903 | return r; | |
2904 | } | |
547973de | 2905 | |
c690b20a ZJS |
2906 | /* Add the validated RRset to the new list of validated |
2907 | * RRsets, and remove it from the unvalidated RRsets. | |
2908 | * We mark the RRset as authenticated and cacheable. */ | |
2909 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE); | |
2910 | if (r < 0) | |
2911 | return r; | |
547973de | 2912 | |
c690b20a | 2913 | manager_dnssec_verdict(t->scope->manager, DNSSEC_SECURE, rr->key); |
0c7bff0a | 2914 | |
c690b20a ZJS |
2915 | /* Exit the loop, we dropped something from the answer, start from the beginning */ |
2916 | return 1; | |
2917 | } | |
547973de | 2918 | |
c690b20a ZJS |
2919 | /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as |
2920 | * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet, | |
2921 | * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */ | |
2922 | if (phase != DNSSEC_PHASE_ALL) | |
2923 | continue; | |
0c7bff0a | 2924 | |
c690b20a ZJS |
2925 | if (result == DNSSEC_VALIDATED_WILDCARD) { |
2926 | bool authenticated = false; | |
2927 | const char *source; | |
0c7bff0a | 2928 | |
c690b20a | 2929 | /* This RRset validated, but as a wildcard. This means we need |
13e785f7 | 2930 | * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */ |
0c7bff0a | 2931 | |
c690b20a ZJS |
2932 | /* First step, determine the source of synthesis */ |
2933 | r = dns_resource_record_source(rrsig, &source); | |
2934 | if (r < 0) | |
2935 | return r; | |
0c7bff0a | 2936 | |
c690b20a | 2937 | r = dnssec_test_positive_wildcard(*validated, |
1c02e7ba | 2938 | dns_resource_key_name(rr->key), |
c690b20a ZJS |
2939 | source, |
2940 | rrsig->rrsig.signer, | |
2941 | &authenticated); | |
0c7bff0a | 2942 | |
c690b20a ZJS |
2943 | /* Unless the NSEC proof showed that the key really doesn't exist something is off. */ |
2944 | if (r == 0) | |
2945 | result = DNSSEC_INVALID; | |
2946 | else { | |
2947 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, | |
2948 | authenticated ? (DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHEABLE) : 0); | |
2949 | if (r < 0) | |
2950 | return r; | |
2951 | ||
2952 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, rr->key); | |
2953 | ||
2954 | /* Exit the loop, we dropped something from the answer, start from the beginning */ | |
2955 | return 1; | |
0c7bff0a | 2956 | } |
c690b20a | 2957 | } |
0c7bff0a | 2958 | |
c690b20a ZJS |
2959 | if (result == DNSSEC_NO_SIGNATURE) { |
2960 | r = dns_transaction_requires_rrsig(t, rr); | |
547973de LP |
2961 | if (r < 0) |
2962 | return r; | |
c690b20a ZJS |
2963 | if (r == 0) { |
2964 | /* Data does not require signing. In that case, just copy it over, | |
13e785f7 | 2965 | * but remember that this is by no means authenticated. */ |
c690b20a ZJS |
2966 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
2967 | if (r < 0) | |
2968 | return r; | |
2969 | ||
2970 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); | |
2971 | return 1; | |
2972 | } | |
547973de | 2973 | |
c690b20a ZJS |
2974 | r = dns_transaction_known_signed(t, rr); |
2975 | if (r < 0) | |
2976 | return r; | |
2977 | if (r > 0) { | |
2978 | /* This is an RR we know has to be signed. If it isn't this means | |
2979 | * the server is not attaching RRSIGs, hence complain. */ | |
547973de | 2980 | |
c690b20a | 2981 | dns_server_packet_rrsig_missing(t->server, t->current_feature_level); |
547973de | 2982 | |
c690b20a | 2983 | if (t->scope->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE) { |
547973de | 2984 | |
c690b20a | 2985 | /* Downgrading is OK? If so, just consider the information unsigned */ |
c9c72065 | 2986 | |
c690b20a | 2987 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
c9c72065 LP |
2988 | if (r < 0) |
2989 | return r; | |
547973de | 2990 | |
c690b20a ZJS |
2991 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
2992 | return 1; | |
2993 | } | |
a150ff5e | 2994 | |
c690b20a ZJS |
2995 | /* Otherwise, fail */ |
2996 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
2997 | return 0; | |
f3cf586d | 2998 | } |
547973de | 2999 | |
c690b20a ZJS |
3000 | r = dns_transaction_in_private_tld(t, rr->key); |
3001 | if (r < 0) | |
3002 | return r; | |
3003 | if (r > 0) { | |
202b76ae | 3004 | char s[DNS_RESOURCE_KEY_STRING_MAX]; |
b652d4a2 | 3005 | |
c690b20a ZJS |
3006 | /* The data is from a TLD that is proven not to exist, and we are in downgrade |
3007 | * mode, hence ignore the fact that this was not signed. */ | |
0c7bff0a | 3008 | |
202b76ae ZJS |
3009 | log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.", |
3010 | dns_resource_key_to_string(rr->key, s, sizeof s)); | |
0c7bff0a | 3011 | |
c690b20a | 3012 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
0c7bff0a LP |
3013 | if (r < 0) |
3014 | return r; | |
0c7bff0a | 3015 | |
c690b20a ZJS |
3016 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3017 | return 1; | |
3018 | } | |
3019 | } | |
0c7bff0a | 3020 | |
c690b20a ZJS |
3021 | if (IN_SET(result, |
3022 | DNSSEC_MISSING_KEY, | |
3023 | DNSSEC_SIGNATURE_EXPIRED, | |
3024 | DNSSEC_UNSUPPORTED_ALGORITHM)) { | |
0c7bff0a | 3025 | |
c690b20a ZJS |
3026 | r = dns_transaction_dnskey_authenticated(t, rr); |
3027 | if (r < 0 && r != -ENXIO) | |
3028 | return r; | |
3029 | if (r == 0) { | |
3030 | /* The DNSKEY transaction was not authenticated, this means there's | |
3031 | * no DS for this, which means it's OK if no keys are found for this signature. */ | |
0c7bff0a | 3032 | |
c690b20a | 3033 | r = dns_answer_move_by_key(validated, &t->answer, rr->key, 0); |
f3cf586d LP |
3034 | if (r < 0) |
3035 | return r; | |
b652d4a2 | 3036 | |
c690b20a ZJS |
3037 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, rr->key); |
3038 | return 1; | |
3039 | } | |
3040 | } | |
b652d4a2 | 3041 | |
c690b20a ZJS |
3042 | r = dns_transaction_is_primary_response(t, rr); |
3043 | if (r < 0) | |
3044 | return r; | |
3045 | if (r > 0) { | |
3046 | /* Look for a matching DNAME for this CNAME */ | |
3047 | r = dns_answer_has_dname_for_cname(t->answer, rr); | |
3048 | if (r < 0) | |
3049 | return r; | |
3050 | if (r == 0) { | |
3051 | /* Also look among the stuff we already validated */ | |
3052 | r = dns_answer_has_dname_for_cname(*validated, rr); | |
f3cf586d LP |
3053 | if (r < 0) |
3054 | return r; | |
c690b20a | 3055 | } |
d33b6cf3 | 3056 | |
c690b20a ZJS |
3057 | if (r == 0) { |
3058 | if (IN_SET(result, | |
3059 | DNSSEC_INVALID, | |
3060 | DNSSEC_SIGNATURE_EXPIRED, | |
3061 | DNSSEC_NO_SIGNATURE)) | |
3062 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, rr->key); | |
3063 | else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */ | |
3064 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, rr->key); | |
3065 | ||
3066 | /* This is a primary response to our question, and it failed validation. | |
3067 | * That's fatal. */ | |
3068 | t->answer_dnssec_result = result; | |
3069 | return 0; | |
3070 | } | |
d33b6cf3 | 3071 | |
c690b20a ZJS |
3072 | /* This is a primary response, but we do have a DNAME RR |
3073 | * in the RR that can replay this CNAME, hence rely on | |
3074 | * that, and we can remove the CNAME in favour of it. */ | |
3075 | } | |
d33b6cf3 | 3076 | |
c690b20a ZJS |
3077 | /* This is just some auxiliary data. Just remove the RRset and continue. */ |
3078 | r = dns_answer_remove_by_key(&t->answer, rr->key); | |
3079 | if (r < 0) | |
3080 | return r; | |
d33b6cf3 | 3081 | |
c690b20a ZJS |
3082 | /* We dropped something from the answer, start from the beginning. */ |
3083 | return 1; | |
3084 | } | |
f3cf586d | 3085 | |
c690b20a ZJS |
3086 | return 2; /* Finito. */ |
3087 | } | |
94aa7071 | 3088 | |
c690b20a ZJS |
3089 | int dns_transaction_validate_dnssec(DnsTransaction *t) { |
3090 | _cleanup_(dns_answer_unrefp) DnsAnswer *validated = NULL; | |
3091 | Phase phase; | |
3092 | DnsAnswerFlags flags; | |
3093 | int r; | |
202b76ae | 3094 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; |
94aa7071 | 3095 | |
c690b20a | 3096 | assert(t); |
94aa7071 | 3097 | |
c690b20a ZJS |
3098 | /* We have now collected all DS and DNSKEY RRs in |
3099 | * t->validated_keys, let's see which RRs we can now | |
3100 | * authenticate with that. */ | |
94aa7071 | 3101 | |
c690b20a ZJS |
3102 | if (t->scope->dnssec_mode == DNSSEC_NO) |
3103 | return 0; | |
a150ff5e | 3104 | |
c690b20a ZJS |
3105 | /* Already validated */ |
3106 | if (t->answer_dnssec_result != _DNSSEC_RESULT_INVALID) | |
3107 | return 0; | |
105e1512 | 3108 | |
c690b20a ZJS |
3109 | /* Our own stuff needs no validation */ |
3110 | if (IN_SET(t->answer_source, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR)) { | |
3111 | t->answer_dnssec_result = DNSSEC_VALIDATED; | |
3112 | t->answer_authenticated = true; | |
3113 | return 0; | |
3114 | } | |
a150ff5e | 3115 | |
c690b20a ZJS |
3116 | /* Cached stuff is not affected by validation. */ |
3117 | if (t->answer_source != DNS_TRANSACTION_NETWORK) | |
3118 | return 0; | |
f3cf586d | 3119 | |
c690b20a ZJS |
3120 | if (!dns_transaction_dnssec_supported_full(t)) { |
3121 | /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */ | |
3122 | t->answer_dnssec_result = DNSSEC_INCOMPATIBLE_SERVER; | |
d001e0a3 | 3123 | log_debug("Not validating response for %" PRIu16 ", used server feature level does not support DNSSEC.", t->id); |
c690b20a ZJS |
3124 | return 0; |
3125 | } | |
f3cf586d | 3126 | |
202b76ae ZJS |
3127 | log_debug("Validating response from transaction %" PRIu16 " (%s).", |
3128 | t->id, | |
3129 | dns_resource_key_to_string(t->key, key_str, sizeof key_str)); | |
547973de | 3130 | |
c690b20a ZJS |
3131 | /* First, see if this response contains any revoked trust |
3132 | * anchors we care about */ | |
3133 | r = dns_transaction_check_revoked_trust_anchors(t); | |
3134 | if (r < 0) | |
3135 | return r; | |
43e6779a | 3136 | |
c690b20a ZJS |
3137 | /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */ |
3138 | r = dns_transaction_copy_validated(t); | |
3139 | if (r < 0) | |
3140 | return r; | |
43e6779a | 3141 | |
c690b20a ZJS |
3142 | /* Second, see if there are DNSKEYs we already know a |
3143 | * validated DS for. */ | |
3144 | r = dns_transaction_validate_dnskey_by_ds(t); | |
3145 | if (r < 0) | |
3146 | return r; | |
43e6779a | 3147 | |
c690b20a ZJS |
3148 | /* Fourth, remove all DNSKEY and DS RRs again that our trust |
3149 | * anchor says are revoked. After all we might have marked | |
3150 | * some keys revoked above, but they might still be lingering | |
3151 | * in our validated_keys list. */ | |
3152 | r = dns_transaction_invalidate_revoked_keys(t); | |
3153 | if (r < 0) | |
3154 | return r; | |
f3cf586d | 3155 | |
c690b20a ZJS |
3156 | phase = DNSSEC_PHASE_DNSKEY; |
3157 | for (;;) { | |
3158 | bool have_nsec = false; | |
f3cf586d | 3159 | |
c690b20a ZJS |
3160 | r = dnssec_validate_records(t, phase, &have_nsec, &validated); |
3161 | if (r <= 0) | |
3162 | return r; | |
547973de | 3163 | |
c690b20a ZJS |
3164 | /* Try again as long as we managed to achieve something */ |
3165 | if (r == 1) | |
547973de LP |
3166 | continue; |
3167 | ||
c690b20a | 3168 | if (phase == DNSSEC_PHASE_DNSKEY && have_nsec) { |
0c7bff0a | 3169 | /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */ |
c690b20a | 3170 | phase = DNSSEC_PHASE_NSEC; |
0c7bff0a LP |
3171 | continue; |
3172 | } | |
3173 | ||
c690b20a ZJS |
3174 | if (phase != DNSSEC_PHASE_ALL) { |
3175 | /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now. | |
3176 | * Note that in this third phase we start to remove RRs we couldn't validate. */ | |
3177 | phase = DNSSEC_PHASE_ALL; | |
56352fe9 | 3178 | continue; |
547973de LP |
3179 | } |
3180 | ||
56352fe9 | 3181 | /* We're done */ |
547973de LP |
3182 | break; |
3183 | } | |
3184 | ||
3185 | dns_answer_unref(t->answer); | |
1cc6c93a | 3186 | t->answer = TAKE_PTR(validated); |
547973de | 3187 | |
72667f08 LP |
3188 | /* At this point the answer only contains validated |
3189 | * RRsets. Now, let's see if it actually answers the question | |
3190 | * we asked. If so, great! If it doesn't, then see if | |
3191 | * NSEC/NSEC3 can prove this. */ | |
105e1512 | 3192 | r = dns_transaction_has_positive_answer(t, &flags); |
72667f08 | 3193 | if (r > 0) { |
105e1512 LP |
3194 | /* Yes, it answers the question! */ |
3195 | ||
3196 | if (flags & DNS_ANSWER_AUTHENTICATED) { | |
3197 | /* The answer is fully authenticated, yay. */ | |
019036a4 | 3198 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
105e1512 LP |
3199 | t->answer_rcode = DNS_RCODE_SUCCESS; |
3200 | t->answer_authenticated = true; | |
3201 | } else { | |
3202 | /* The answer is not fully authenticated. */ | |
019036a4 | 3203 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 LP |
3204 | t->answer_authenticated = false; |
3205 | } | |
3206 | ||
72667f08 LP |
3207 | } else if (r == 0) { |
3208 | DnssecNsecResult nr; | |
ed29bfdc | 3209 | bool authenticated = false; |
72667f08 LP |
3210 | |
3211 | /* Bummer! Let's check NSEC/NSEC3 */ | |
0c7bff0a | 3212 | r = dnssec_nsec_test(t->answer, t->key, &nr, &authenticated, &t->answer_nsec_ttl); |
72667f08 LP |
3213 | if (r < 0) |
3214 | return r; | |
3215 | ||
3216 | switch (nr) { | |
3217 | ||
3218 | case DNSSEC_NSEC_NXDOMAIN: | |
3219 | /* NSEC proves the domain doesn't exist. Very good. */ | |
202b76ae | 3220 | log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3221 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3222 | t->answer_rcode = DNS_RCODE_NXDOMAIN; |
ed29bfdc | 3223 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3224 | |
59c5b597 | 3225 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3226 | break; |
3227 | ||
3228 | case DNSSEC_NSEC_NODATA: | |
3229 | /* NSEC proves that there's no data here, very good. */ | |
202b76ae | 3230 | log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3231 | t->answer_dnssec_result = DNSSEC_VALIDATED; |
72667f08 | 3232 | t->answer_rcode = DNS_RCODE_SUCCESS; |
ed29bfdc | 3233 | t->answer_authenticated = authenticated; |
7aa8ce98 | 3234 | |
59c5b597 | 3235 | manager_dnssec_verdict(t->scope->manager, authenticated ? DNSSEC_SECURE : DNSSEC_INSECURE, t->key); |
72667f08 LP |
3236 | break; |
3237 | ||
105e1512 LP |
3238 | case DNSSEC_NSEC_OPTOUT: |
3239 | /* NSEC3 says the data might not be signed */ | |
202b76ae | 3240 | log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t->id, key_str); |
019036a4 | 3241 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3242 | t->answer_authenticated = false; |
7aa8ce98 | 3243 | |
59c5b597 | 3244 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3245 | break; |
3246 | ||
72667f08 LP |
3247 | case DNSSEC_NSEC_NO_RR: |
3248 | /* No NSEC data? Bummer! */ | |
105e1512 LP |
3249 | |
3250 | r = dns_transaction_requires_nsec(t); | |
3251 | if (r < 0) | |
3252 | return r; | |
7aa8ce98 | 3253 | if (r > 0) { |
019036a4 | 3254 | t->answer_dnssec_result = DNSSEC_NO_SIGNATURE; |
59c5b597 | 3255 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
7aa8ce98 | 3256 | } else { |
019036a4 | 3257 | t->answer_dnssec_result = DNSSEC_UNSIGNED; |
105e1512 | 3258 | t->answer_authenticated = false; |
59c5b597 | 3259 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INSECURE, t->key); |
105e1512 LP |
3260 | } |
3261 | ||
3262 | break; | |
3263 | ||
3264 | case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM: | |
3265 | /* We don't know the NSEC3 algorithm used? */ | |
019036a4 | 3266 | t->answer_dnssec_result = DNSSEC_UNSUPPORTED_ALGORITHM; |
59c5b597 | 3267 | manager_dnssec_verdict(t->scope->manager, DNSSEC_INDETERMINATE, t->key); |
72667f08 LP |
3268 | break; |
3269 | ||
3270 | case DNSSEC_NSEC_FOUND: | |
146035b3 | 3271 | case DNSSEC_NSEC_CNAME: |
72667f08 | 3272 | /* NSEC says it needs to be there, but we couldn't find it? Bummer! */ |
019036a4 | 3273 | t->answer_dnssec_result = DNSSEC_NSEC_MISMATCH; |
59c5b597 | 3274 | manager_dnssec_verdict(t->scope->manager, DNSSEC_BOGUS, t->key); |
72667f08 LP |
3275 | break; |
3276 | ||
3277 | default: | |
3278 | assert_not_reached("Unexpected NSEC result."); | |
3279 | } | |
3280 | } | |
3281 | ||
547973de LP |
3282 | return 1; |
3283 | } | |
3284 | ||
ec2c5e43 LP |
3285 | static const char* const dns_transaction_state_table[_DNS_TRANSACTION_STATE_MAX] = { |
3286 | [DNS_TRANSACTION_NULL] = "null", | |
3287 | [DNS_TRANSACTION_PENDING] = "pending", | |
547973de | 3288 | [DNS_TRANSACTION_VALIDATING] = "validating", |
3bbdc31d | 3289 | [DNS_TRANSACTION_RCODE_FAILURE] = "rcode-failure", |
ec2c5e43 LP |
3290 | [DNS_TRANSACTION_SUCCESS] = "success", |
3291 | [DNS_TRANSACTION_NO_SERVERS] = "no-servers", | |
3292 | [DNS_TRANSACTION_TIMEOUT] = "timeout", | |
3293 | [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED] = "attempts-max-reached", | |
3294 | [DNS_TRANSACTION_INVALID_REPLY] = "invalid-reply", | |
7cc6ed7b | 3295 | [DNS_TRANSACTION_ERRNO] = "errno", |
ec2c5e43 | 3296 | [DNS_TRANSACTION_ABORTED] = "aborted", |
547973de | 3297 | [DNS_TRANSACTION_DNSSEC_FAILED] = "dnssec-failed", |
b2b796b8 | 3298 | [DNS_TRANSACTION_NO_TRUST_ANCHOR] = "no-trust-anchor", |
91adc4db | 3299 | [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED] = "rr-type-unsupported", |
edbcc1fd | 3300 | [DNS_TRANSACTION_NETWORK_DOWN] = "network-down", |
0791110f | 3301 | [DNS_TRANSACTION_NOT_FOUND] = "not-found", |
ec2c5e43 LP |
3302 | }; |
3303 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state, DnsTransactionState); | |
c3bc53e6 LP |
3304 | |
3305 | static const char* const dns_transaction_source_table[_DNS_TRANSACTION_SOURCE_MAX] = { | |
3306 | [DNS_TRANSACTION_NETWORK] = "network", | |
3307 | [DNS_TRANSACTION_CACHE] = "cache", | |
3308 | [DNS_TRANSACTION_ZONE] = "zone", | |
0d2cd476 | 3309 | [DNS_TRANSACTION_TRUST_ANCHOR] = "trust-anchor", |
c3bc53e6 LP |
3310 | }; |
3311 | DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source, DnsTransactionSource); |