1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2014 Lennart Poettering
8 #include "sd-messages.h"
11 #include "alloc-util.h"
12 #include "dns-domain.h"
13 #include "errno-list.h"
15 #include "random-util.h"
16 #include "resolved-dns-cache.h"
17 #include "resolved-dns-transaction.h"
18 #include "resolved-llmnr.h"
19 #include "string-table.h"
21 #define TRANSACTIONS_MAX 4096
22 #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
24 static void dns_transaction_reset_answer(DnsTransaction
*t
) {
27 t
->received
= dns_packet_unref(t
->received
);
28 t
->answer
= dns_answer_unref(t
->answer
);
30 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
31 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
32 t
->answer_authenticated
= false;
33 t
->answer_nsec_ttl
= (uint32_t) -1;
37 static void dns_transaction_flush_dnssec_transactions(DnsTransaction
*t
) {
42 while ((z
= set_steal_first(t
->dnssec_transactions
))) {
43 set_remove(z
->notify_transactions
, t
);
44 set_remove(z
->notify_transactions_done
, t
);
45 dns_transaction_gc(z
);
49 static void dns_transaction_close_connection(DnsTransaction
*t
) {
53 /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
54 LIST_REMOVE(transactions_by_stream
, t
->stream
->transactions
, t
);
56 /* Remove packet in case it's still in the queue */
57 dns_packet_unref(ordered_set_remove(t
->stream
->write_queue
, t
->sent
));
59 t
->stream
= dns_stream_unref(t
->stream
);
62 t
->dns_udp_event_source
= sd_event_source_unref(t
->dns_udp_event_source
);
63 t
->dns_udp_fd
= safe_close(t
->dns_udp_fd
);
66 static void dns_transaction_stop_timeout(DnsTransaction
*t
) {
69 t
->timeout_event_source
= sd_event_source_unref(t
->timeout_event_source
);
72 DnsTransaction
* dns_transaction_free(DnsTransaction
*t
) {
80 log_debug("Freeing transaction %" PRIu16
".", t
->id
);
82 dns_transaction_close_connection(t
);
83 dns_transaction_stop_timeout(t
);
85 dns_packet_unref(t
->sent
);
86 dns_transaction_reset_answer(t
);
88 dns_server_unref(t
->server
);
91 hashmap_remove_value(t
->scope
->transactions_by_key
, t
->key
, t
);
92 LIST_REMOVE(transactions_by_scope
, t
->scope
->transactions
, t
);
95 hashmap_remove(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
98 while ((c
= set_steal_first(t
->notify_query_candidates
)))
99 set_remove(c
->transactions
, t
);
100 set_free(t
->notify_query_candidates
);
102 while ((c
= set_steal_first(t
->notify_query_candidates_done
)))
103 set_remove(c
->transactions
, t
);
104 set_free(t
->notify_query_candidates_done
);
106 while ((i
= set_steal_first(t
->notify_zone_items
)))
107 i
->probe_transaction
= NULL
;
108 set_free(t
->notify_zone_items
);
110 while ((i
= set_steal_first(t
->notify_zone_items_done
)))
111 i
->probe_transaction
= NULL
;
112 set_free(t
->notify_zone_items_done
);
114 while ((z
= set_steal_first(t
->notify_transactions
)))
115 set_remove(z
->dnssec_transactions
, t
);
116 set_free(t
->notify_transactions
);
118 while ((z
= set_steal_first(t
->notify_transactions_done
)))
119 set_remove(z
->dnssec_transactions
, t
);
120 set_free(t
->notify_transactions_done
);
122 dns_transaction_flush_dnssec_transactions(t
);
123 set_free(t
->dnssec_transactions
);
125 dns_answer_unref(t
->validated_keys
);
126 dns_resource_key_unref(t
->key
);
131 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction
*, dns_transaction_free
);
133 bool dns_transaction_gc(DnsTransaction
*t
) {
139 if (set_isempty(t
->notify_query_candidates
) &&
140 set_isempty(t
->notify_query_candidates_done
) &&
141 set_isempty(t
->notify_zone_items
) &&
142 set_isempty(t
->notify_zone_items_done
) &&
143 set_isempty(t
->notify_transactions
) &&
144 set_isempty(t
->notify_transactions_done
)) {
145 dns_transaction_free(t
);
152 static uint16_t pick_new_id(Manager
*m
) {
155 /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of
156 * transactions, and it's much lower than the space of IDs. */
158 assert_cc(TRANSACTIONS_MAX
< 0xFFFF);
161 random_bytes(&new_id
, sizeof(new_id
));
162 while (new_id
== 0 ||
163 hashmap_get(m
->dns_transactions
, UINT_TO_PTR(new_id
)));
168 int dns_transaction_new(DnsTransaction
**ret
, DnsScope
*s
, DnsResourceKey
*key
) {
169 _cleanup_(dns_transaction_freep
) DnsTransaction
*t
= NULL
;
176 /* Don't allow looking up invalid or pseudo RRs */
177 if (!dns_type_is_valid_query(key
->type
))
179 if (dns_type_is_obsolete(key
->type
))
182 /* We only support the IN class */
183 if (!IN_SET(key
->class, DNS_CLASS_IN
, DNS_CLASS_ANY
))
186 if (hashmap_size(s
->manager
->dns_transactions
) >= TRANSACTIONS_MAX
)
189 r
= hashmap_ensure_allocated(&s
->manager
->dns_transactions
, NULL
);
193 r
= hashmap_ensure_allocated(&s
->transactions_by_key
, &dns_resource_key_hash_ops
);
197 t
= new0(DnsTransaction
, 1);
202 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
203 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
204 t
->answer_nsec_ttl
= (uint32_t) -1;
205 t
->key
= dns_resource_key_ref(key
);
206 t
->current_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
207 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
209 t
->id
= pick_new_id(s
->manager
);
211 r
= hashmap_put(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), t
);
217 r
= hashmap_replace(s
->transactions_by_key
, t
->key
, t
);
219 hashmap_remove(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
223 LIST_PREPEND(transactions_by_scope
, s
->transactions
, t
);
226 s
->manager
->n_transactions_total
++;
236 static void dns_transaction_shuffle_id(DnsTransaction
*t
) {
240 /* Pick a new ID for this transaction. */
242 new_id
= pick_new_id(t
->scope
->manager
);
243 assert_se(hashmap_remove_and_put(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), UINT_TO_PTR(new_id
), t
) >= 0);
245 log_debug("Transaction %" PRIu16
" is now %" PRIu16
".", t
->id
, new_id
);
248 /* Make sure we generate a new packet with the new ID */
249 t
->sent
= dns_packet_unref(t
->sent
);
252 static void dns_transaction_tentative(DnsTransaction
*t
, DnsPacket
*p
) {
253 _cleanup_free_
char *pretty
= NULL
;
254 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
260 if (manager_our_packet(t
->scope
->manager
, p
) != 0)
263 (void) in_addr_to_string(p
->family
, &p
->sender
, &pretty
);
265 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s got tentative packet from %s.",
267 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
268 dns_protocol_to_string(t
->scope
->protocol
),
269 t
->scope
->link
? t
->scope
->link
->name
: "*",
270 af_to_name_short(t
->scope
->family
),
273 /* RFC 4795, Section 4.1 says that the peer with the
274 * lexicographically smaller IP address loses */
275 if (memcmp(&p
->sender
, &p
->destination
, FAMILY_ADDRESS_SIZE(p
->family
)) >= 0) {
276 log_debug("Peer has lexicographically larger IP address and thus lost in the conflict.");
280 log_debug("We have the lexicographically larger IP address and thus lost in the conflict.");
284 while ((z
= set_first(t
->notify_zone_items
))) {
285 /* First, make sure the zone item drops the reference
287 dns_zone_item_probe_stop(z
);
289 /* Secondly, report this as conflict, so that we might
290 * look for a different hostname */
291 dns_zone_item_conflict(z
);
295 dns_transaction_gc(t
);
298 void dns_transaction_complete(DnsTransaction
*t
, DnsTransactionState state
) {
299 DnsQueryCandidate
*c
;
303 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
306 assert(!DNS_TRANSACTION_IS_LIVE(state
));
308 if (state
== DNS_TRANSACTION_DNSSEC_FAILED
) {
309 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
);
311 log_struct(LOG_NOTICE
,
312 "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR
,
313 LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str
, dnssec_result_to_string(t
->answer_dnssec_result
)),
314 "DNS_TRANSACTION=%" PRIu16
, t
->id
,
315 "DNS_QUESTION=%s", key_str
,
316 "DNSSEC_RESULT=%s", dnssec_result_to_string(t
->answer_dnssec_result
),
317 "DNS_SERVER=%s", dns_server_string(t
->server
),
318 "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t
->server
->possible_feature_level
));
321 /* Note that this call might invalidate the query. Callers
322 * should hence not attempt to access the query or transaction
323 * after calling this function. */
325 if (state
== DNS_TRANSACTION_ERRNO
)
326 st
= errno_to_name(t
->answer_errno
);
328 st
= dns_transaction_state_to_string(state
);
330 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).",
332 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
333 dns_protocol_to_string(t
->scope
->protocol
),
334 t
->scope
->link
? t
->scope
->link
->name
: "*",
335 af_to_name_short(t
->scope
->family
),
337 t
->answer_source
< 0 ? "none" : dns_transaction_source_to_string(t
->answer_source
),
338 t
->answer_authenticated
? "authenticated" : "unsigned");
342 dns_transaction_close_connection(t
);
343 dns_transaction_stop_timeout(t
);
345 /* Notify all queries that are interested, but make sure the
346 * transaction isn't freed while we are still looking at it */
349 SET_FOREACH_MOVE(c
, t
->notify_query_candidates_done
, t
->notify_query_candidates
)
350 dns_query_candidate_notify(c
);
351 SWAP_TWO(t
->notify_query_candidates
, t
->notify_query_candidates_done
);
353 SET_FOREACH_MOVE(z
, t
->notify_zone_items_done
, t
->notify_zone_items
)
354 dns_zone_item_notify(z
);
355 SWAP_TWO(t
->notify_zone_items
, t
->notify_zone_items_done
);
356 if (t
->probing
&& t
->state
== DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
)
357 (void) dns_scope_announce(t
->scope
, false);
359 SET_FOREACH_MOVE(d
, t
->notify_transactions_done
, t
->notify_transactions
)
360 dns_transaction_notify(d
, t
);
361 SWAP_TWO(t
->notify_transactions
, t
->notify_transactions_done
);
364 dns_transaction_gc(t
);
367 static int dns_transaction_pick_server(DnsTransaction
*t
) {
371 assert(t
->scope
->protocol
== DNS_PROTOCOL_DNS
);
373 /* Pick a DNS server and a feature level for it. */
375 server
= dns_scope_get_dns_server(t
->scope
);
379 /* If we changed the server invalidate the feature level clamping, as the new server might have completely
380 * different properties. */
381 if (server
!= t
->server
)
382 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
384 t
->current_feature_level
= dns_server_possible_feature_level(server
);
386 /* Clamp the feature level if that is requested. */
387 if (t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
&&
388 t
->current_feature_level
> t
->clamp_feature_level
)
389 t
->current_feature_level
= t
->clamp_feature_level
;
391 log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t
->current_feature_level
), t
->id
);
393 if (server
== t
->server
)
396 dns_server_unref(t
->server
);
397 t
->server
= dns_server_ref(server
);
399 t
->n_picked_servers
++;
401 log_debug("Using DNS server %s for transaction %u.", dns_server_string(t
->server
), t
->id
);
406 static void dns_transaction_retry(DnsTransaction
*t
, bool next_server
) {
411 log_debug("Retrying transaction %" PRIu16
".", t
->id
);
413 /* Before we try again, switch to a new server. */
415 dns_scope_next_dns_server(t
->scope
);
417 r
= dns_transaction_go(t
);
419 t
->answer_errno
= -r
;
420 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
424 static int dns_transaction_maybe_restart(DnsTransaction
*t
) {
429 /* Returns > 0 if the transaction was restarted, 0 if not */
434 if (t
->current_feature_level
<= dns_server_possible_feature_level(t
->server
))
437 /* The server's current feature level is lower than when we sent the original query. We learnt something from
438 the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to
439 restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include
440 OPT RR or DO bit. One of these cases is documented here, for example:
441 https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */
443 log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID.");
444 dns_transaction_shuffle_id(t
);
446 r
= dns_transaction_go(t
);
453 static void on_transaction_stream_error(DnsTransaction
*t
, int error
) {
456 dns_transaction_close_connection(t
);
458 if (ERRNO_IS_DISCONNECT(error
)) {
459 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
) {
460 /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
461 * question on this scope. */
462 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
465 dns_transaction_retry(t
, true);
468 t
->answer_errno
= error
;
469 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
473 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
477 dns_transaction_close_connection(t
);
479 if (dns_packet_validate_reply(p
) <= 0) {
480 log_debug("Invalid TCP reply packet.");
481 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
485 dns_scope_check_conflicts(t
->scope
, p
);
488 dns_transaction_process_reply(t
, p
);
491 /* If the response wasn't useful, then complete the transition
492 * now. After all, we are the worst feature set now with TCP
493 * sockets, and there's really no point in retrying. */
494 if (t
->state
== DNS_TRANSACTION_PENDING
)
495 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
497 dns_transaction_gc(t
);
502 static int on_stream_complete(DnsStream
*s
, int error
) {
503 DnsTransaction
*t
, *n
;
506 /* Do not let new transactions use this stream */
507 if (s
->server
&& s
->server
->stream
== s
)
508 s
->server
->stream
= dns_stream_unref(s
->server
->stream
);
510 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
513 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
515 if (s
->transactions
) {
517 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
518 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
, usec
- t
->start_usec
);
522 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
524 on_transaction_stream_error(t
, error
);
525 else if (DNS_PACKET_ID(s
->read_packet
) == t
->id
)
526 /* As each transaction have a unique id the return code is only set once */
527 r
= dns_transaction_on_stream_packet(t
, s
->read_packet
);
532 static int dns_stream_on_packet(DnsStream
*s
) {
533 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
537 /* Take ownership of packet to be able to receive new packets */
538 p
= TAKE_PTR(s
->read_packet
);
541 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
543 /* Ignore incorrect transaction id as transaction can have been canceled */
545 r
= dns_transaction_on_stream_packet(t
, p
);
547 if (dns_packet_validate_reply(p
) <= 0) {
548 log_debug("Invalid TCP reply packet.");
549 on_stream_complete(s
, 0);
557 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
558 _cleanup_close_
int fd
= -1;
559 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
564 dns_transaction_close_connection(t
);
566 switch (t
->scope
->protocol
) {
568 case DNS_PROTOCOL_DNS
:
569 r
= dns_transaction_pick_server(t
);
573 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
576 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
580 if (t
->server
->stream
)
581 s
= dns_stream_ref(t
->server
->stream
);
583 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, 53);
587 case DNS_PROTOCOL_LLMNR
:
588 /* When we already received a reply to this (but it was truncated), send to its sender address */
590 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
);
592 union in_addr_union address
;
593 int family
= AF_UNSPEC
;
595 /* Otherwise, try to talk to the owner of a
596 * the IP address, in case this is a reverse
599 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
604 if (family
!= t
->scope
->family
)
607 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
);
613 return -EAFNOSUPPORT
;
620 r
= dns_stream_new(t
->scope
->manager
, &s
, t
->scope
->protocol
, fd
);
627 dns_stream_unref(t
->server
->stream
);
628 t
->server
->stream
= dns_stream_ref(s
);
629 s
->server
= dns_server_ref(t
->server
);
632 s
->complete
= on_stream_complete
;
633 s
->on_packet
= dns_stream_on_packet
;
635 /* The interface index is difficult to determine if we are
636 * connecting to the local host, hence fill this in right away
637 * instead of determining it from the socket */
638 s
->ifindex
= dns_scope_ifindex(t
->scope
);
641 t
->stream
= TAKE_PTR(s
);
642 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
644 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
646 dns_transaction_close_connection(t
);
650 dns_transaction_reset_answer(t
);
652 t
->tried_stream
= true;
657 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
660 /* For mDNS we cache whenever we get the packet, rather than
661 * in each transaction. */
662 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
665 /* Caching disabled? */
666 if (!t
->scope
->manager
->enable_cache
)
669 /* We never cache if this packet is from the local host, under
670 * the assumption that a locally running DNS server would
671 * cache this anyway, and probably knows better when to flush
672 * the cache then we could. */
673 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
676 dns_cache_put(&t
->scope
->cache
,
680 t
->answer_authenticated
,
684 &t
->received
->sender
);
687 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
693 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
694 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
700 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
706 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
707 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
709 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
713 case DNS_TRANSACTION_NULL
:
714 case DNS_TRANSACTION_PENDING
:
715 case DNS_TRANSACTION_VALIDATING
:
719 case DNS_TRANSACTION_RCODE_FAILURE
:
720 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
721 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
725 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
726 * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
727 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
728 * RRs to make unsigned proofs. */
730 case DNS_TRANSACTION_SUCCESS
:
734 case DNS_TRANSACTION_DNSSEC_FAILED
:
735 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
736 * validationr result */
738 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
739 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
740 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
744 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
749 /* All is ready, we can go and validate */
753 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
754 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
758 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
763 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
764 r
= dns_transaction_dnssec_ready(t
);
767 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
770 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
771 * restart the lookup immediately. */
772 r
= dns_transaction_maybe_restart(t
);
775 if (r
> 0) /* Transaction got restarted... */
778 /* All our auxiliary DNSSEC transactions are complete now. Try
779 * to validate our RRset now. */
780 r
= dns_transaction_validate_dnssec(t
);
782 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
788 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
789 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
791 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
794 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
795 /* We tried fewer servers on this transaction than we know, let's try another one then */
796 dns_transaction_retry(t
, true);
800 /* OK, let's give up, apparently all servers we tried didn't work. */
801 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
805 if (!IN_SET(t
->answer_dnssec_result
,
806 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
807 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
808 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
809 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
810 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
814 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
815 dns_server_warn_downgrade(t
->server
);
817 dns_transaction_cache_answer(t
);
819 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
820 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
822 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
827 t
->answer_errno
= -r
;
828 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
831 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
836 /* Checks whether the answer is positive, i.e. either a direct
837 * answer to the question, or a CNAME/DNAME for it */
839 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
843 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
850 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
855 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
856 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
857 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
858 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
859 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
860 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
861 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
862 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
863 * incomplete CNAME/DNAME chain.
865 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
866 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
869 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
872 r
= dns_transaction_has_positive_answer(t
, NULL
);
876 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
880 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
887 assert(t
->scope
->manager
);
889 if (t
->state
!= DNS_TRANSACTION_PENDING
)
892 /* Note that this call might invalidate the query. Callers
893 * should hence not attempt to access the query or transaction
894 * after calling this function. */
896 log_debug("Processing incoming packet on transaction %" PRIu16
". (rcode=%s)", t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
898 switch (t
->scope
->protocol
) {
900 case DNS_PROTOCOL_LLMNR
:
901 /* For LLMNR we will not accept any packets from other interfaces */
903 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
906 if (p
->family
!= t
->scope
->family
)
909 /* Tentative packets are not full responses but still
910 * useful for identifying uniqueness conflicts during
912 if (DNS_PACKET_LLMNR_T(p
)) {
913 dns_transaction_tentative(t
, p
);
919 case DNS_PROTOCOL_MDNS
:
920 /* For mDNS we will not accept any packets from other interfaces */
922 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
925 if (p
->family
!= t
->scope
->family
)
930 case DNS_PROTOCOL_DNS
:
931 /* Note that we do not need to verify the
932 * addresses/port numbers of incoming traffic, as we
933 * invoked connect() on our UDP socket in which case
934 * the kernel already does the needed verification for
939 assert_not_reached("Invalid DNS protocol.");
942 if (t
->received
!= p
) {
943 dns_packet_unref(t
->received
);
944 t
->received
= dns_packet_ref(p
);
947 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
949 if (p
->ipproto
== IPPROTO_TCP
) {
950 if (DNS_PACKET_TC(p
)) {
951 /* Truncated via TCP? Somebody must be fucking with us */
952 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
956 if (DNS_PACKET_ID(p
) != t
->id
) {
957 /* Not the reply to our query? Somebody must be fucking with us */
958 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
963 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
965 switch (t
->scope
->protocol
) {
967 case DNS_PROTOCOL_DNS
:
970 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
972 /* Request failed, immediately try again with reduced features */
974 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
976 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
977 * this transaction anymore, but let's see if it might make sense to send the request
978 * to a different DNS server instead. If not let's process the response, and accept the
979 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
980 * packet loss, but is not going to give us better rcodes should we actually have
981 * managed to get them already at UDP level. */
983 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
984 /* We tried fewer servers on this transaction than we know, let's try another one then */
985 dns_transaction_retry(t
, true);
989 /* Give up, accept the rcode */
990 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
994 /* Reduce this feature level by one and try again. */
995 t
->clamp_feature_level
= t
->current_feature_level
- 1;
997 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
998 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
999 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1001 dns_transaction_retry(t
, false /* use the same server */);
1005 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1006 /* This server refused our request? If so, try again, use a different server */
1007 log_debug("Server returned REFUSED, switching servers, and retrying.");
1008 dns_transaction_retry(t
, true /* pick a new server */);
1012 if (DNS_PACKET_TC(p
))
1013 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1017 case DNS_PROTOCOL_LLMNR
:
1018 case DNS_PROTOCOL_MDNS
:
1019 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1023 assert_not_reached("Invalid DNS protocol.");
1026 if (DNS_PACKET_TC(p
)) {
1028 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1029 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1030 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1034 log_debug("Reply truncated, retrying via TCP.");
1036 /* Response was truncated, let's try again with good old TCP */
1037 r
= dns_transaction_emit_tcp(t
);
1039 /* No servers found? Damn! */
1040 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1043 if (r
== -EOPNOTSUPP
) {
1044 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1045 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1049 /* On LLMNR, if we cannot connect to the host,
1050 * we immediately give up */
1051 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1054 /* On DNS, couldn't send? Try immediately again, with a new server */
1055 dns_transaction_retry(t
, true);
1061 /* After the superficial checks, actually parse the message. */
1062 r
= dns_packet_extract(p
);
1064 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1069 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1070 * rcode and subsequently downgraded the protocol */
1072 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1073 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1074 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1076 /* Report that the OPT RR was missing */
1078 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1080 /* Report that we successfully received a packet */
1081 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, ts
- t
->start_usec
, p
->size
);
1084 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1085 r
= dns_transaction_maybe_restart(t
);
1088 if (r
> 0) /* Transaction got restarted... */
1091 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1093 /* When dealing with protocols other than mDNS only consider responses with
1094 * equivalent query section to the request. For mDNS this check doesn't make
1095 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1096 * contain any questions in the Question Section". */
1097 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1098 r
= dns_packet_is_reply_for(p
, t
->key
);
1102 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1107 /* Install the answer as answer to the transaction */
1108 dns_answer_unref(t
->answer
);
1109 t
->answer
= dns_answer_ref(p
->answer
);
1110 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1111 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1112 t
->answer_authenticated
= false;
1114 r
= dns_transaction_fix_rcode(t
);
1118 /* Block GC while starting requests for additional DNSSEC RRs */
1120 r
= dns_transaction_request_dnssec_keys(t
);
1123 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1124 if (!dns_transaction_gc(t
))
1127 /* Requesting additional keys might have resulted in
1128 * this transaction to fail, since the auxiliary
1129 * request failed for some reason. If so, we are not
1130 * in pending state anymore, and we should exit
1132 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1137 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1138 t
->state
= DNS_TRANSACTION_VALIDATING
;
1139 dns_transaction_close_connection(t
);
1140 dns_transaction_stop_timeout(t
);
1145 dns_transaction_process_dnssec(t
);
1149 t
->answer_errno
= -r
;
1150 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1153 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1154 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1155 DnsTransaction
*t
= userdata
;
1161 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1162 if (ERRNO_IS_DISCONNECT(-r
)) {
1165 /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next
1166 * recvmsg(). Treat this like a lost packet. */
1168 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1169 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1170 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
, usec
- t
->start_usec
);
1172 dns_transaction_retry(t
, true);
1176 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1177 t
->answer_errno
= -r
;
1181 r
= dns_packet_validate_reply(p
);
1183 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1187 log_debug("Received inappropriate DNS packet as response, ignoring.");
1191 if (DNS_PACKET_ID(p
) != t
->id
) {
1192 log_debug("Received packet with incorrect transaction ID, ignoring.");
1196 dns_transaction_process_reply(t
, p
);
1200 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1205 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1207 r
= dns_transaction_pick_server(t
);
1211 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
)
1212 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1214 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1217 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1220 dns_transaction_close_connection(t
);
1222 fd
= dns_scope_socket_udp(t
->scope
, t
->server
, 53);
1226 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1232 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1236 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1240 dns_transaction_close_connection(t
);
1242 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1246 dns_transaction_reset_answer(t
);
1251 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1252 DnsTransaction
*t
= userdata
;
1257 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1258 /* Timeout reached? Increase the timeout for the server used */
1259 switch (t
->scope
->protocol
) {
1261 case DNS_PROTOCOL_DNS
:
1263 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
, usec
- t
->start_usec
);
1266 case DNS_PROTOCOL_LLMNR
:
1267 case DNS_PROTOCOL_MDNS
:
1268 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1272 assert_not_reached("Invalid DNS protocol.");
1275 if (t
->initial_jitter_scheduled
)
1276 t
->initial_jitter_elapsed
= true;
1279 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1281 dns_transaction_retry(t
, true);
1285 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1289 switch (t
->scope
->protocol
) {
1291 case DNS_PROTOCOL_DNS
:
1293 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1294 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1297 return TRANSACTION_TCP_TIMEOUT_USEC
;
1300 return t
->server
->resend_timeout
;
1302 case DNS_PROTOCOL_MDNS
:
1303 assert(t
->n_attempts
> 0);
1305 return MDNS_PROBING_INTERVAL_USEC
;
1307 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1309 case DNS_PROTOCOL_LLMNR
:
1310 return t
->scope
->resend_timeout
;
1313 assert_not_reached("Invalid DNS protocol.");
1317 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1322 dns_transaction_stop_timeout(t
);
1324 r
= dns_scope_network_good(t
->scope
);
1328 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1332 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1333 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1337 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1338 /* If we already tried via a stream, then we don't
1339 * retry on LLMNR. See RFC 4795, Section 2.7. */
1340 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1347 dns_transaction_reset_answer(t
);
1348 dns_transaction_flush_dnssec_transactions(t
);
1350 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1351 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1352 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1356 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1357 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1358 t
->answer_authenticated
= true;
1359 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1363 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1364 t
->key
->type
== DNS_TYPE_DS
) {
1366 /* Hmm, this is a request for the root DS? A
1367 * DS RR doesn't exist in the root zone, and
1368 * if our trust anchor didn't know it either,
1369 * this means we cannot do any DNSSEC logic
1372 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1373 /* We are in downgrade mode. In this
1374 * case, synthesize an unsigned empty
1375 * response, so that the any lookup
1376 * depending on this one can continue
1377 * assuming there was no DS, and hence
1378 * the root zone was unsigned. */
1380 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1381 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1382 t
->answer_authenticated
= false;
1383 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1385 /* If we are not in downgrade mode,
1386 * then fail the lookup, because we
1387 * cannot reasonably answer it. There
1388 * might be DS RRs, but we don't know
1389 * them, and the DNS server won't tell
1390 * them to us (and even if it would,
1391 * we couldn't validate and trust them. */
1392 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1398 /* Check the zone, but only if this transaction is not used
1399 * for probing or verifying a zone item. */
1400 if (set_isempty(t
->notify_zone_items
)) {
1402 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1406 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1407 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1408 t
->answer_authenticated
= true;
1409 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1414 /* Check the cache, but only if this transaction is not used
1415 * for probing or verifying a zone item. */
1416 if (set_isempty(t
->notify_zone_items
)) {
1418 /* Before trying the cache, let's make sure we figured out a
1419 * server to use. Should this cause a change of server this
1420 * might flush the cache. */
1421 (void) dns_scope_get_dns_server(t
->scope
);
1423 /* Let's then prune all outdated entries */
1424 dns_cache_prune(&t
->scope
->cache
);
1426 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1430 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1431 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1432 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1434 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1442 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1444 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1445 bool add_known_answers
= false;
1446 DnsTransaction
*other
;
1448 DnsResourceKey
*tkey
;
1449 _cleanup_set_free_ Set
*keys
= NULL
;
1451 unsigned nscount
= 0;
1456 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1458 /* Discard any previously prepared packet, so we can start over and coalesce again */
1459 t
->sent
= dns_packet_unref(t
->sent
);
1461 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1465 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1471 if (dns_key_is_shared(t
->key
))
1472 add_known_answers
= true;
1474 if (t
->key
->type
== DNS_TYPE_ANY
) {
1475 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1479 r
= set_put(keys
, t
->key
);
1485 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1486 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1487 * in our current scope, and see whether their timing contraints allow them to be sent.
1490 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1492 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1494 /* Skip ourselves */
1498 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1501 if (other
->next_attempt_after
> ts
)
1504 if (qdcount
>= UINT16_MAX
)
1507 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1510 * If we can't stuff more questions into the packet, just give up.
1511 * One of the 'other' transactions will fire later and take care of the rest.
1519 r
= dns_transaction_prepare(other
, ts
);
1523 ts
+= transaction_get_resend_timeout(other
);
1525 r
= sd_event_add_time(
1526 other
->scope
->manager
->event
,
1527 &other
->timeout_event_source
,
1528 clock_boottime_or_monotonic(),
1530 on_transaction_timeout
, other
);
1534 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1536 other
->state
= DNS_TRANSACTION_PENDING
;
1537 other
->next_attempt_after
= ts
;
1541 if (dns_key_is_shared(other
->key
))
1542 add_known_answers
= true;
1544 if (other
->key
->type
== DNS_TYPE_ANY
) {
1545 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1549 r
= set_put(keys
, other
->key
);
1555 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1557 /* Append known answer section if we're asking for any shared record */
1558 if (add_known_answers
) {
1559 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1564 SET_FOREACH(tkey
, keys
, i
) {
1565 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1568 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1572 r
= dns_packet_append_answer(p
, answer
);
1576 nscount
+= dns_answer_size(answer
);
1578 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1580 t
->sent
= TAKE_PTR(p
);
1585 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1586 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1591 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1592 return dns_transaction_make_packet_mdns(t
);
1597 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1601 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1605 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1606 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1608 t
->sent
= TAKE_PTR(p
);
1613 int dns_transaction_go(DnsTransaction
*t
) {
1616 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1620 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1623 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1625 r
= dns_transaction_prepare(t
, ts
);
1629 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1631 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1632 dns_protocol_to_string(t
->scope
->protocol
),
1633 t
->scope
->link
? t
->scope
->link
->name
: "*",
1634 af_to_name_short(t
->scope
->family
));
1636 if (!t
->initial_jitter_scheduled
&&
1637 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1638 usec_t jitter
, accuracy
;
1640 /* RFC 4795 Section 2.7 suggests all queries should be
1641 * delayed by a random time from 0 to JITTER_INTERVAL. */
1643 t
->initial_jitter_scheduled
= true;
1645 random_bytes(&jitter
, sizeof(jitter
));
1647 switch (t
->scope
->protocol
) {
1649 case DNS_PROTOCOL_LLMNR
:
1650 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1651 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1654 case DNS_PROTOCOL_MDNS
:
1655 jitter
%= MDNS_JITTER_RANGE_USEC
;
1656 jitter
+= MDNS_JITTER_MIN_USEC
;
1657 accuracy
= MDNS_JITTER_RANGE_USEC
;
1660 assert_not_reached("bad protocol");
1663 r
= sd_event_add_time(
1664 t
->scope
->manager
->event
,
1665 &t
->timeout_event_source
,
1666 clock_boottime_or_monotonic(),
1667 ts
+ jitter
, accuracy
,
1668 on_transaction_timeout
, t
);
1672 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1675 t
->next_attempt_after
= ts
;
1676 t
->state
= DNS_TRANSACTION_PENDING
;
1678 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1682 /* Otherwise, we need to ask the network */
1683 r
= dns_transaction_make_packet(t
);
1687 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1688 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1689 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1691 /* RFC 4795, Section 2.4. says reverse lookups shall
1692 * always be made via TCP on LLMNR */
1693 r
= dns_transaction_emit_tcp(t
);
1695 /* Try via UDP, and if that fails due to large size or lack of
1696 * support try via TCP */
1697 r
= dns_transaction_emit_udp(t
);
1699 log_debug("Sending query via TCP since it is too large.");
1700 else if (r
== -EAGAIN
)
1701 log_debug("Sending query via TCP since server doesn't support UDP.");
1702 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1703 r
= dns_transaction_emit_tcp(t
);
1707 /* No servers to send this to? */
1708 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1711 if (r
== -EOPNOTSUPP
) {
1712 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1713 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1716 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1717 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1718 * answer this request with this protocol. */
1719 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1723 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1726 /* Couldn't send? Try immediately again, with a new server */
1727 dns_scope_next_dns_server(t
->scope
);
1729 return dns_transaction_go(t
);
1732 ts
+= transaction_get_resend_timeout(t
);
1734 r
= sd_event_add_time(
1735 t
->scope
->manager
->event
,
1736 &t
->timeout_event_source
,
1737 clock_boottime_or_monotonic(),
1739 on_transaction_timeout
, t
);
1743 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1745 t
->state
= DNS_TRANSACTION_PENDING
;
1746 t
->next_attempt_after
= ts
;
1751 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1759 /* Try to find cyclic dependencies between transaction objects */
1764 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1765 r
= dns_transaction_find_cyclic(t
, n
);
1773 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1774 DnsTransaction
*aux
;
1781 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1783 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1787 if (set_contains(t
->dnssec_transactions
, aux
)) {
1792 r
= dns_transaction_find_cyclic(t
, aux
);
1796 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1798 log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1800 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1802 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1808 r
= set_ensure_allocated(&t
->dnssec_transactions
, NULL
);
1812 r
= set_ensure_allocated(&aux
->notify_transactions
, NULL
);
1816 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1820 r
= set_put(t
->dnssec_transactions
, aux
);
1824 r
= set_put(aux
->notify_transactions
, t
);
1826 (void) set_remove(t
->dnssec_transactions
, aux
);
1834 dns_transaction_gc(aux
);
1838 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1839 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1840 DnsTransaction
*aux
;
1846 /* Try to get the data from the trust anchor */
1847 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1851 r
= dns_answer_extend(&t
->validated_keys
, a
);
1858 /* This didn't work, ask for it via the network/cache then. */
1859 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1860 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1865 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1866 r
= dns_transaction_go(aux
);
1874 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1879 /* Check whether the specified name is in the NTA
1880 * database, either in the global one, or the link-local
1883 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1887 if (!t
->scope
->link
)
1890 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1893 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1898 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1899 * RRs to prove it */
1901 r
= dns_transaction_has_positive_answer(t
, NULL
);
1907 /* Is this key explicitly listed as a negative trust anchor?
1908 * If so, it's nothing we need to care about */
1909 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1915 /* The answer does not contain any RRs that match to the
1916 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1917 * included. If not, the answer is unsigned. */
1919 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1928 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1934 /* Check if the specified RR is the "primary" response,
1935 * i.e. either matches the question precisely or is a
1936 * CNAME/DNAME for it. */
1938 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1942 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1945 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1948 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1949 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1951 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1954 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1955 * be supported, hence return true. */
1959 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1960 * the server is known to support currently, as the transaction feature level might be lower than what the
1961 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1962 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1964 return dns_server_dnssec_supported(t
->server
);
1967 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1973 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1975 if (!dns_transaction_dnssec_supported(t
))
1978 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1979 if (!dns_transaction_dnssec_supported(dt
))
1985 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
1986 DnsResourceRecord
*rr
;
1993 * Retrieve all auxiliary RRs for the answer we got, so that
1994 * we can verify signatures or prove that RRs are rightfully
1995 * unsigned. Specifically:
1997 * - For RRSIG we get the matching DNSKEY
1998 * - For DNSKEY we get the matching DS
1999 * - For unsigned SOA/NS we get the matching DS
2000 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2001 * - For other unsigned RRs we get the matching SOA RR
2002 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2003 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2004 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2007 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2009 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2010 return 0; /* We only need to validate stuff from the network */
2011 if (!dns_transaction_dnssec_supported(t
))
2012 return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */
2014 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2016 if (dns_type_is_pseudo(rr
->key
->type
))
2019 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2020 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2026 switch (rr
->key
->type
) {
2028 case DNS_TYPE_RRSIG
: {
2029 /* For each RRSIG we request the matching DNSKEY */
2030 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2032 /* If this RRSIG is about a DNSKEY RR and the
2033 * signer is the same as the owner, then we
2034 * already have the DNSKEY, and we don't have
2035 * to look for more. */
2036 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2037 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2044 /* If the signer is not a parent of our
2045 * original query, then this is about an
2046 * auxiliary RRset, but not anything we asked
2047 * for. In this case we aren't interested,
2048 * because we don't want to request additional
2049 * RRs for stuff we didn't really ask for, and
2050 * also to avoid request loops, where
2051 * additional RRs from one transaction result
2052 * in another transaction whose additonal RRs
2053 * point back to the original transaction, and
2055 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2061 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2065 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2066 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2067 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2073 case DNS_TYPE_DNSKEY
: {
2074 /* For each DNSKEY we request the matching DS */
2075 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2077 /* If the DNSKEY we are looking at is not for
2078 * zone we are interested in, nor any of its
2079 * parents, we aren't interested, and don't
2080 * request it. After all, we don't want to end
2081 * up in request loops, and want to keep
2082 * additional traffic down. */
2084 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2090 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2094 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2095 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2096 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2105 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2107 /* For an unsigned SOA or NS, try to acquire
2108 * the matching DS RR, as we are at a zone cut
2109 * then, and whether a DS exists tells us
2110 * whether the zone is signed. Do so only if
2111 * this RR matches our original question,
2114 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2118 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2119 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2120 * If so, we need to validate it, too. */
2122 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2125 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2130 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2136 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2140 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2141 t
->id
, dns_resource_key_name(rr
->key
));
2142 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2150 case DNS_TYPE_CNAME
:
2151 case DNS_TYPE_DNAME
: {
2152 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2155 /* CNAMEs and DNAMEs cannot be located at a
2156 * zone apex, hence ask for the parent SOA for
2157 * unsigned CNAME/DNAME RRs, maybe that's the
2158 * apex. But do all that only if this is
2159 * actually a response to our original
2162 * Similar for DS RRs, which are signed when
2163 * the parent SOA is signed. */
2165 r
= dns_transaction_is_primary_response(t
, rr
);
2171 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2177 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2183 name
= dns_resource_key_name(rr
->key
);
2184 r
= dns_name_parent(&name
);
2190 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2194 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2195 t
->id
, dns_resource_key_name(rr
->key
));
2196 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2204 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2206 /* For other unsigned RRsets (including
2207 * NSEC/NSEC3!), look for proof the zone is
2208 * unsigned, by requesting the SOA RR of the
2209 * zone. However, do so only if they are
2210 * directly relevant to our original
2213 r
= dns_transaction_is_primary_response(t
, rr
);
2219 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2225 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2229 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2230 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2231 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2238 /* Above, we requested everything necessary to validate what
2239 * we got. Now, let's request what we need to validate what we
2242 r
= dns_transaction_has_unsigned_negative_answer(t
);
2249 name
= dns_resource_key_name(t
->key
);
2251 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2252 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2253 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2254 * though they have further children. If this was a DS request, then it's signed when the parent zone
2255 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2256 * to see if that is signed. */
2258 if (t
->key
->type
== DNS_TYPE_DS
) {
2259 r
= dns_name_parent(&name
);
2261 type
= DNS_TYPE_SOA
;
2262 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2263 t
->id
, dns_resource_key_name(t
->key
));
2267 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2270 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2271 t
->id
, dns_resource_key_name(t
->key
));
2274 type
= DNS_TYPE_SOA
;
2275 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2276 t
->id
, dns_resource_key_name(t
->key
));
2280 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2282 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2286 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2292 return dns_transaction_dnssec_is_live(t
);
2295 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2299 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2300 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2301 the state is VALIDATING however, we should check if we are complete now. */
2303 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2304 dns_transaction_process_dnssec(t
);
2307 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2308 DnsResourceRecord
*rr
;
2313 /* Add all DNSKEY RRs from the answer that are validated by DS
2314 * RRs from the list of validated keys to the list of
2315 * validated keys. */
2317 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2319 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2325 /* If so, the DNSKEY is validated too. */
2326 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2334 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2340 /* Checks if the RR we are looking for must be signed with an
2341 * RRSIG. This is used for positive responses. */
2343 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2346 if (dns_type_is_pseudo(rr
->key
->type
))
2349 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2355 switch (rr
->key
->type
) {
2357 case DNS_TYPE_RRSIG
:
2358 /* RRSIGs are the signatures themselves, they need no signing. */
2366 /* For SOA or NS RRs we look for a matching DS transaction */
2368 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2370 if (dt
->key
->class != rr
->key
->class)
2372 if (dt
->key
->type
!= DNS_TYPE_DS
)
2375 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2381 /* We found a DS transactions for the SOA/NS
2382 * RRs we are looking at. If it discovered signed DS
2383 * RRs, then we need to be signed, too. */
2385 if (!dt
->answer_authenticated
)
2388 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2391 /* We found nothing that proves this is safe to leave
2392 * this unauthenticated, hence ask inist on
2393 * authentication. */
2398 case DNS_TYPE_CNAME
:
2399 case DNS_TYPE_DNAME
: {
2400 const char *parent
= NULL
;
2405 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2407 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2410 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2412 if (dt
->key
->class != rr
->key
->class)
2414 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2418 parent
= dns_resource_key_name(rr
->key
);
2419 r
= dns_name_parent(&parent
);
2423 if (rr
->key
->type
== DNS_TYPE_DS
)
2426 /* A CNAME/DNAME without a parent? That's sooo weird. */
2427 log_debug("Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2432 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2438 return t
->answer_authenticated
;
2448 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2450 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2452 if (dt
->key
->class != rr
->key
->class)
2454 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2457 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2463 /* We found the transaction that was supposed to find
2464 * the SOA RR for us. It was successful, but found no
2465 * RR for us. This means we are not at a zone cut. In
2466 * this case, we require authentication if the SOA
2467 * lookup was authenticated too. */
2468 return t
->answer_authenticated
;
2475 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2481 /* If DNSSEC downgrade mode is on, checks whether the
2482 * specified RR is one level below a TLD we have proven not to
2483 * exist. In such a case we assume that this is a private
2484 * domain, and permit it.
2486 * This detects cases like the Fritz!Box router networks. Each
2487 * Fritz!Box router serves a private "fritz.box" zone, in the
2488 * non-existing TLD "box". Requests for the "fritz.box" domain
2489 * are served by the router itself, while requests for the
2490 * "box" domain will result in NXDOMAIN.
2492 * Note that this logic is unable to detect cases where a
2493 * router serves a private DNS zone directly under
2494 * non-existing TLD. In such a case we cannot detect whether
2495 * the TLD is supposed to exist or not, as all requests we
2496 * make for it will be answered by the router's zone, and not
2497 * by the root zone. */
2501 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2502 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2504 tld
= dns_resource_key_name(key
);
2505 r
= dns_name_parent(&tld
);
2509 return false; /* Already the root domain */
2511 if (!dns_name_is_single_label(tld
))
2514 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2516 if (dt
->key
->class != key
->class)
2519 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2525 /* We found an auxiliary lookup we did for the TLD. If
2526 * that returned with NXDOMAIN, we know the TLD didn't
2527 * exist, and hence this might be a private zone. */
2529 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2535 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2536 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2545 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2546 * this negative reply */
2548 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2551 if (dns_type_is_pseudo(t
->key
->type
))
2554 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2560 r
= dns_transaction_in_private_tld(t
, t
->key
);
2564 /* The lookup is from a TLD that is proven not to
2565 * exist, and we are in downgrade mode, hence ignore
2566 * that fact that we didn't get any NSEC RRs. */
2568 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2569 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2573 name
= dns_resource_key_name(t
->key
);
2575 if (t
->key
->type
== DNS_TYPE_DS
) {
2577 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2578 * hence check the parent SOA in this case. */
2580 r
= dns_name_parent(&name
);
2586 type
= DNS_TYPE_SOA
;
2588 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2589 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2592 /* For all other negative replies, check for the SOA lookup */
2593 type
= DNS_TYPE_SOA
;
2595 /* For all other RRs we check the SOA on the same level to see
2596 * if it's signed. */
2598 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2600 if (dt
->key
->class != t
->key
->class)
2602 if (dt
->key
->type
!= type
)
2605 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2611 return dt
->answer_authenticated
;
2614 /* If in doubt, require NSEC/NSEC3 */
2618 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2619 DnsResourceRecord
*rrsig
;
2623 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2624 * the specified RRset is authenticated (i.e. has a matching
2627 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2633 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2637 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2643 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2645 if (dt
->key
->class != rr
->key
->class)
2648 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2650 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2656 /* OK, we found an auxiliary DNSKEY
2657 * lookup. If that lookup is
2658 * authenticated, report this. */
2660 if (dt
->answer_authenticated
)
2665 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2667 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2673 /* OK, we found an auxiliary DS
2674 * lookup. If that lookup is
2675 * authenticated and non-zero, we
2678 if (!dt
->answer_authenticated
)
2681 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2686 return found
? false : -ENXIO
;
2689 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2693 /* We know that the root domain is signed, hence if it appears
2694 * not to be signed, there's a problem with the DNS server */
2696 return rr
->key
->class == DNS_CLASS_IN
&&
2697 dns_name_is_root(dns_resource_key_name(rr
->key
));
2700 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2701 DnsResourceRecord
*rr
;
2706 /* Maybe warn the user that we encountered a revoked DNSKEY
2707 * for a key from our trust anchor. Note that we don't care
2708 * whether the DNSKEY can be authenticated or not. It's
2709 * sufficient if it is self-signed. */
2711 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2712 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2720 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2726 /* Removes all DNSKEY/DS objects from t->validated_keys that
2727 * our trust anchors database considers revoked. */
2730 DnsResourceRecord
*rr
;
2734 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2735 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2739 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2753 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2760 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2762 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2764 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2767 if (!dt
->answer_authenticated
)
2770 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2779 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2780 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2781 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2784 static int dnssec_validate_records(
2788 DnsAnswer
**validated
) {
2790 DnsResourceRecord
*rr
;
2793 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2795 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2796 DnsResourceRecord
*rrsig
= NULL
;
2797 DnssecResult result
;
2799 switch (rr
->key
->type
) {
2800 case DNS_TYPE_RRSIG
:
2803 case DNS_TYPE_DNSKEY
:
2804 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2805 if (phase
== DNSSEC_PHASE_NSEC
)
2810 case DNS_TYPE_NSEC3
:
2813 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2814 if (phase
== DNSSEC_PHASE_DNSKEY
)
2819 /* We validate all other RRs only in the ALL phases */
2820 if (phase
!= DNSSEC_PHASE_ALL
)
2824 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2828 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2830 if (result
== DNSSEC_VALIDATED
) {
2832 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2833 /* If we just validated a DNSKEY RRset, then let's add these keys to
2834 * the set of validated keys for this transaction. */
2836 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2840 /* Some of the DNSKEYs we just added might already have been revoked,
2841 * remove them again in that case. */
2842 r
= dns_transaction_invalidate_revoked_keys(t
);
2847 /* Add the validated RRset to the new list of validated
2848 * RRsets, and remove it from the unvalidated RRsets.
2849 * We mark the RRset as authenticated and cacheable. */
2850 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2854 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2856 /* Exit the loop, we dropped something from the answer, start from the beginning */
2860 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2861 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2862 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2863 if (phase
!= DNSSEC_PHASE_ALL
)
2866 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2867 bool authenticated
= false;
2870 /* This RRset validated, but as a wildcard. This means we need
2871 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2873 /* First step, determine the source of synthesis */
2874 r
= dns_resource_record_source(rrsig
, &source
);
2878 r
= dnssec_test_positive_wildcard(*validated
,
2879 dns_resource_key_name(rr
->key
),
2881 rrsig
->rrsig
.signer
,
2884 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2886 result
= DNSSEC_INVALID
;
2888 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2889 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2893 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2895 /* Exit the loop, we dropped something from the answer, start from the beginning */
2900 if (result
== DNSSEC_NO_SIGNATURE
) {
2901 r
= dns_transaction_requires_rrsig(t
, rr
);
2905 /* Data does not require signing. In that case, just copy it over,
2906 * but remember that this is by no means authenticated. */
2907 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2911 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2915 r
= dns_transaction_known_signed(t
, rr
);
2919 /* This is an RR we know has to be signed. If it isn't this means
2920 * the server is not attaching RRSIGs, hence complain. */
2922 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2924 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2926 /* Downgrading is OK? If so, just consider the information unsigned */
2928 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2932 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2936 /* Otherwise, fail */
2937 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2941 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2945 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2947 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2948 * mode, hence ignore the fact that this was not signed. */
2950 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2951 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2953 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2957 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2964 DNSSEC_SIGNATURE_EXPIRED
,
2965 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2967 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2968 if (r
< 0 && r
!= -ENXIO
)
2971 /* The DNSKEY transaction was not authenticated, this means there's
2972 * no DS for this, which means it's OK if no keys are found for this signature. */
2974 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2978 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2983 r
= dns_transaction_is_primary_response(t
, rr
);
2987 /* Look for a matching DNAME for this CNAME */
2988 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2992 /* Also look among the stuff we already validated */
2993 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3001 DNSSEC_SIGNATURE_EXPIRED
,
3002 DNSSEC_NO_SIGNATURE
))
3003 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3004 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3005 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3007 /* This is a primary response to our question, and it failed validation.
3009 t
->answer_dnssec_result
= result
;
3013 /* This is a primary response, but we do have a DNAME RR
3014 * in the RR that can replay this CNAME, hence rely on
3015 * that, and we can remove the CNAME in favour of it. */
3018 /* This is just some auxiliary data. Just remove the RRset and continue. */
3019 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3023 /* We dropped something from the answer, start from the beginning. */
3027 return 2; /* Finito. */
3030 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3031 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3033 DnsAnswerFlags flags
;
3035 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3039 /* We have now collected all DS and DNSKEY RRs in
3040 * t->validated_keys, let's see which RRs we can now
3041 * authenticate with that. */
3043 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3046 /* Already validated */
3047 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3050 /* Our own stuff needs no validation */
3051 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3052 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3053 t
->answer_authenticated
= true;
3057 /* Cached stuff is not affected by validation. */
3058 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3061 if (!dns_transaction_dnssec_supported_full(t
)) {
3062 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3063 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3064 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3068 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3070 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3072 /* First, see if this response contains any revoked trust
3073 * anchors we care about */
3074 r
= dns_transaction_check_revoked_trust_anchors(t
);
3078 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3079 r
= dns_transaction_copy_validated(t
);
3083 /* Second, see if there are DNSKEYs we already know a
3084 * validated DS for. */
3085 r
= dns_transaction_validate_dnskey_by_ds(t
);
3089 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3090 * anchor says are revoked. After all we might have marked
3091 * some keys revoked above, but they might still be lingering
3092 * in our validated_keys list. */
3093 r
= dns_transaction_invalidate_revoked_keys(t
);
3097 phase
= DNSSEC_PHASE_DNSKEY
;
3099 bool have_nsec
= false;
3101 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3105 /* Try again as long as we managed to achieve something */
3109 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3110 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3111 phase
= DNSSEC_PHASE_NSEC
;
3115 if (phase
!= DNSSEC_PHASE_ALL
) {
3116 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3117 * Note that in this third phase we start to remove RRs we couldn't validate. */
3118 phase
= DNSSEC_PHASE_ALL
;
3126 dns_answer_unref(t
->answer
);
3127 t
->answer
= TAKE_PTR(validated
);
3129 /* At this point the answer only contains validated
3130 * RRsets. Now, let's see if it actually answers the question
3131 * we asked. If so, great! If it doesn't, then see if
3132 * NSEC/NSEC3 can prove this. */
3133 r
= dns_transaction_has_positive_answer(t
, &flags
);
3135 /* Yes, it answers the question! */
3137 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3138 /* The answer is fully authenticated, yay. */
3139 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3140 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3141 t
->answer_authenticated
= true;
3143 /* The answer is not fully authenticated. */
3144 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3145 t
->answer_authenticated
= false;
3148 } else if (r
== 0) {
3149 DnssecNsecResult nr
;
3150 bool authenticated
= false;
3152 /* Bummer! Let's check NSEC/NSEC3 */
3153 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3159 case DNSSEC_NSEC_NXDOMAIN
:
3160 /* NSEC proves the domain doesn't exist. Very good. */
3161 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3162 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3163 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3164 t
->answer_authenticated
= authenticated
;
3166 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3169 case DNSSEC_NSEC_NODATA
:
3170 /* NSEC proves that there's no data here, very good. */
3171 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3172 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3173 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3174 t
->answer_authenticated
= authenticated
;
3176 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3179 case DNSSEC_NSEC_OPTOUT
:
3180 /* NSEC3 says the data might not be signed */
3181 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3182 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3183 t
->answer_authenticated
= false;
3185 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3188 case DNSSEC_NSEC_NO_RR
:
3189 /* No NSEC data? Bummer! */
3191 r
= dns_transaction_requires_nsec(t
);
3195 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3196 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3198 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3199 t
->answer_authenticated
= false;
3200 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3205 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3206 /* We don't know the NSEC3 algorithm used? */
3207 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3208 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3211 case DNSSEC_NSEC_FOUND
:
3212 case DNSSEC_NSEC_CNAME
:
3213 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3214 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3215 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3219 assert_not_reached("Unexpected NSEC result.");
3226 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3227 [DNS_TRANSACTION_NULL
] = "null",
3228 [DNS_TRANSACTION_PENDING
] = "pending",
3229 [DNS_TRANSACTION_VALIDATING
] = "validating",
3230 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3231 [DNS_TRANSACTION_SUCCESS
] = "success",
3232 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3233 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3234 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3235 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3236 [DNS_TRANSACTION_ERRNO
] = "errno",
3237 [DNS_TRANSACTION_ABORTED
] = "aborted",
3238 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3239 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3240 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3241 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3242 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3244 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3246 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3247 [DNS_TRANSACTION_NETWORK
] = "network",
3248 [DNS_TRANSACTION_CACHE
] = "cache",
3249 [DNS_TRANSACTION_ZONE
] = "zone",
3250 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3252 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);