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
;
560 union sockaddr_union sa
;
565 dns_transaction_close_connection(t
);
567 switch (t
->scope
->protocol
) {
569 case DNS_PROTOCOL_DNS
:
570 r
= dns_transaction_pick_server(t
);
574 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
577 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
581 if (t
->server
->stream
)
582 s
= dns_stream_ref(t
->server
->stream
);
584 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, 53, &sa
);
588 case DNS_PROTOCOL_LLMNR
:
589 /* When we already received a reply to this (but it was truncated), send to its sender address */
591 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
, &sa
);
593 union in_addr_union address
;
594 int family
= AF_UNSPEC
;
596 /* Otherwise, try to talk to the owner of a
597 * the IP address, in case this is a reverse
600 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
605 if (family
!= t
->scope
->family
)
608 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
, &sa
);
614 return -EAFNOSUPPORT
;
621 r
= dns_stream_new(t
->scope
->manager
, &s
, t
->scope
->protocol
, fd
, &sa
);
628 dns_stream_unref(t
->server
->stream
);
629 t
->server
->stream
= dns_stream_ref(s
);
630 s
->server
= dns_server_ref(t
->server
);
633 s
->complete
= on_stream_complete
;
634 s
->on_packet
= dns_stream_on_packet
;
636 /* The interface index is difficult to determine if we are
637 * connecting to the local host, hence fill this in right away
638 * instead of determining it from the socket */
639 s
->ifindex
= dns_scope_ifindex(t
->scope
);
642 t
->stream
= TAKE_PTR(s
);
643 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
645 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
647 dns_transaction_close_connection(t
);
651 dns_transaction_reset_answer(t
);
653 t
->tried_stream
= true;
658 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
661 /* For mDNS we cache whenever we get the packet, rather than
662 * in each transaction. */
663 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
666 /* Caching disabled? */
667 if (!t
->scope
->manager
->enable_cache
)
670 /* We never cache if this packet is from the local host, under
671 * the assumption that a locally running DNS server would
672 * cache this anyway, and probably knows better when to flush
673 * the cache then we could. */
674 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
677 dns_cache_put(&t
->scope
->cache
,
681 t
->answer_authenticated
,
685 &t
->received
->sender
);
688 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
694 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
695 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
701 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
707 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
708 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
710 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
714 case DNS_TRANSACTION_NULL
:
715 case DNS_TRANSACTION_PENDING
:
716 case DNS_TRANSACTION_VALIDATING
:
720 case DNS_TRANSACTION_RCODE_FAILURE
:
721 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
722 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
726 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
727 * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
728 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
729 * RRs to make unsigned proofs. */
731 case DNS_TRANSACTION_SUCCESS
:
735 case DNS_TRANSACTION_DNSSEC_FAILED
:
736 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
737 * validationr result */
739 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
740 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
741 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
745 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
750 /* All is ready, we can go and validate */
754 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
755 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
759 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
764 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
765 r
= dns_transaction_dnssec_ready(t
);
768 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
771 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
772 * restart the lookup immediately. */
773 r
= dns_transaction_maybe_restart(t
);
776 if (r
> 0) /* Transaction got restarted... */
779 /* All our auxiliary DNSSEC transactions are complete now. Try
780 * to validate our RRset now. */
781 r
= dns_transaction_validate_dnssec(t
);
783 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
789 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
790 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
792 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
795 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
796 /* We tried fewer servers on this transaction than we know, let's try another one then */
797 dns_transaction_retry(t
, true);
801 /* OK, let's give up, apparently all servers we tried didn't work. */
802 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
806 if (!IN_SET(t
->answer_dnssec_result
,
807 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
808 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
809 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
810 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
811 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
815 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
816 dns_server_warn_downgrade(t
->server
);
818 dns_transaction_cache_answer(t
);
820 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
821 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
823 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
828 t
->answer_errno
= -r
;
829 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
832 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
837 /* Checks whether the answer is positive, i.e. either a direct
838 * answer to the question, or a CNAME/DNAME for it */
840 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
844 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
851 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
856 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
857 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
858 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
859 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
860 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
861 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
862 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
863 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
864 * incomplete CNAME/DNAME chain.
866 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
867 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
870 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
873 r
= dns_transaction_has_positive_answer(t
, NULL
);
877 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
881 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
888 assert(t
->scope
->manager
);
890 if (t
->state
!= DNS_TRANSACTION_PENDING
)
893 /* Note that this call might invalidate the query. Callers
894 * should hence not attempt to access the query or transaction
895 * after calling this function. */
897 log_debug("Processing incoming packet on transaction %" PRIu16
". (rcode=%s)", t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
899 switch (t
->scope
->protocol
) {
901 case DNS_PROTOCOL_LLMNR
:
902 /* For LLMNR we will not accept any packets from other interfaces */
904 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
907 if (p
->family
!= t
->scope
->family
)
910 /* Tentative packets are not full responses but still
911 * useful for identifying uniqueness conflicts during
913 if (DNS_PACKET_LLMNR_T(p
)) {
914 dns_transaction_tentative(t
, p
);
920 case DNS_PROTOCOL_MDNS
:
921 /* For mDNS we will not accept any packets from other interfaces */
923 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
926 if (p
->family
!= t
->scope
->family
)
931 case DNS_PROTOCOL_DNS
:
932 /* Note that we do not need to verify the
933 * addresses/port numbers of incoming traffic, as we
934 * invoked connect() on our UDP socket in which case
935 * the kernel already does the needed verification for
940 assert_not_reached("Invalid DNS protocol.");
943 if (t
->received
!= p
) {
944 dns_packet_unref(t
->received
);
945 t
->received
= dns_packet_ref(p
);
948 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
950 if (p
->ipproto
== IPPROTO_TCP
) {
951 if (DNS_PACKET_TC(p
)) {
952 /* Truncated via TCP? Somebody must be fucking with us */
953 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
957 if (DNS_PACKET_ID(p
) != t
->id
) {
958 /* Not the reply to our query? Somebody must be fucking with us */
959 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
964 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
966 switch (t
->scope
->protocol
) {
968 case DNS_PROTOCOL_DNS
:
971 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
973 /* Request failed, immediately try again with reduced features */
975 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
977 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
978 * this transaction anymore, but let's see if it might make sense to send the request
979 * to a different DNS server instead. If not let's process the response, and accept the
980 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
981 * packet loss, but is not going to give us better rcodes should we actually have
982 * managed to get them already at UDP level. */
984 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
985 /* We tried fewer servers on this transaction than we know, let's try another one then */
986 dns_transaction_retry(t
, true);
990 /* Give up, accept the rcode */
991 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
995 /* Reduce this feature level by one and try again. */
996 t
->clamp_feature_level
= t
->current_feature_level
- 1;
998 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
999 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1000 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1002 dns_transaction_retry(t
, false /* use the same server */);
1006 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1007 /* This server refused our request? If so, try again, use a different server */
1008 log_debug("Server returned REFUSED, switching servers, and retrying.");
1009 dns_transaction_retry(t
, true /* pick a new server */);
1013 if (DNS_PACKET_TC(p
))
1014 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1018 case DNS_PROTOCOL_LLMNR
:
1019 case DNS_PROTOCOL_MDNS
:
1020 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1024 assert_not_reached("Invalid DNS protocol.");
1027 if (DNS_PACKET_TC(p
)) {
1029 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1030 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1031 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1035 log_debug("Reply truncated, retrying via TCP.");
1037 /* Response was truncated, let's try again with good old TCP */
1038 r
= dns_transaction_emit_tcp(t
);
1040 /* No servers found? Damn! */
1041 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1044 if (r
== -EOPNOTSUPP
) {
1045 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1046 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1050 /* On LLMNR, if we cannot connect to the host,
1051 * we immediately give up */
1052 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1055 /* On DNS, couldn't send? Try immediately again, with a new server */
1056 dns_transaction_retry(t
, true);
1062 /* After the superficial checks, actually parse the message. */
1063 r
= dns_packet_extract(p
);
1065 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1070 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1071 * rcode and subsequently downgraded the protocol */
1073 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1074 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1075 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1077 /* Report that the OPT RR was missing */
1079 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1081 /* Report that we successfully received a packet */
1082 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, ts
- t
->start_usec
, p
->size
);
1085 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1086 r
= dns_transaction_maybe_restart(t
);
1089 if (r
> 0) /* Transaction got restarted... */
1092 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1094 /* When dealing with protocols other than mDNS only consider responses with
1095 * equivalent query section to the request. For mDNS this check doesn't make
1096 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1097 * contain any questions in the Question Section". */
1098 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1099 r
= dns_packet_is_reply_for(p
, t
->key
);
1103 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1108 /* Install the answer as answer to the transaction */
1109 dns_answer_unref(t
->answer
);
1110 t
->answer
= dns_answer_ref(p
->answer
);
1111 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1112 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1113 t
->answer_authenticated
= false;
1115 r
= dns_transaction_fix_rcode(t
);
1119 /* Block GC while starting requests for additional DNSSEC RRs */
1121 r
= dns_transaction_request_dnssec_keys(t
);
1124 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1125 if (!dns_transaction_gc(t
))
1128 /* Requesting additional keys might have resulted in
1129 * this transaction to fail, since the auxiliary
1130 * request failed for some reason. If so, we are not
1131 * in pending state anymore, and we should exit
1133 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1138 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1139 t
->state
= DNS_TRANSACTION_VALIDATING
;
1140 dns_transaction_close_connection(t
);
1141 dns_transaction_stop_timeout(t
);
1146 dns_transaction_process_dnssec(t
);
1150 t
->answer_errno
= -r
;
1151 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1154 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1155 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1156 DnsTransaction
*t
= userdata
;
1162 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1163 if (ERRNO_IS_DISCONNECT(-r
)) {
1166 /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next
1167 * recvmsg(). Treat this like a lost packet. */
1169 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1170 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1171 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
, usec
- t
->start_usec
);
1173 dns_transaction_retry(t
, true);
1177 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1178 t
->answer_errno
= -r
;
1182 r
= dns_packet_validate_reply(p
);
1184 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1188 log_debug("Received inappropriate DNS packet as response, ignoring.");
1192 if (DNS_PACKET_ID(p
) != t
->id
) {
1193 log_debug("Received packet with incorrect transaction ID, ignoring.");
1197 dns_transaction_process_reply(t
, p
);
1201 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1206 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1208 r
= dns_transaction_pick_server(t
);
1212 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
)
1213 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1215 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1218 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1221 dns_transaction_close_connection(t
);
1223 fd
= dns_scope_socket_udp(t
->scope
, t
->server
, 53);
1227 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1233 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1237 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1241 dns_transaction_close_connection(t
);
1243 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1247 dns_transaction_reset_answer(t
);
1252 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1253 DnsTransaction
*t
= userdata
;
1258 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1259 /* Timeout reached? Increase the timeout for the server used */
1260 switch (t
->scope
->protocol
) {
1262 case DNS_PROTOCOL_DNS
:
1264 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
, usec
- t
->start_usec
);
1267 case DNS_PROTOCOL_LLMNR
:
1268 case DNS_PROTOCOL_MDNS
:
1269 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1273 assert_not_reached("Invalid DNS protocol.");
1276 if (t
->initial_jitter_scheduled
)
1277 t
->initial_jitter_elapsed
= true;
1280 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1282 dns_transaction_retry(t
, true);
1286 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1290 switch (t
->scope
->protocol
) {
1292 case DNS_PROTOCOL_DNS
:
1294 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1295 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1298 return TRANSACTION_TCP_TIMEOUT_USEC
;
1301 return t
->server
->resend_timeout
;
1303 case DNS_PROTOCOL_MDNS
:
1304 assert(t
->n_attempts
> 0);
1306 return MDNS_PROBING_INTERVAL_USEC
;
1308 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1310 case DNS_PROTOCOL_LLMNR
:
1311 return t
->scope
->resend_timeout
;
1314 assert_not_reached("Invalid DNS protocol.");
1318 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1323 dns_transaction_stop_timeout(t
);
1325 r
= dns_scope_network_good(t
->scope
);
1329 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1333 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1334 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1338 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1339 /* If we already tried via a stream, then we don't
1340 * retry on LLMNR. See RFC 4795, Section 2.7. */
1341 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1348 dns_transaction_reset_answer(t
);
1349 dns_transaction_flush_dnssec_transactions(t
);
1351 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1352 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1353 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1357 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1358 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1359 t
->answer_authenticated
= true;
1360 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1364 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1365 t
->key
->type
== DNS_TYPE_DS
) {
1367 /* Hmm, this is a request for the root DS? A
1368 * DS RR doesn't exist in the root zone, and
1369 * if our trust anchor didn't know it either,
1370 * this means we cannot do any DNSSEC logic
1373 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1374 /* We are in downgrade mode. In this
1375 * case, synthesize an unsigned empty
1376 * response, so that the any lookup
1377 * depending on this one can continue
1378 * assuming there was no DS, and hence
1379 * the root zone was unsigned. */
1381 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1382 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1383 t
->answer_authenticated
= false;
1384 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1386 /* If we are not in downgrade mode,
1387 * then fail the lookup, because we
1388 * cannot reasonably answer it. There
1389 * might be DS RRs, but we don't know
1390 * them, and the DNS server won't tell
1391 * them to us (and even if it would,
1392 * we couldn't validate and trust them. */
1393 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1399 /* Check the zone, but only if this transaction is not used
1400 * for probing or verifying a zone item. */
1401 if (set_isempty(t
->notify_zone_items
)) {
1403 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1407 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1408 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1409 t
->answer_authenticated
= true;
1410 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1415 /* Check the cache, but only if this transaction is not used
1416 * for probing or verifying a zone item. */
1417 if (set_isempty(t
->notify_zone_items
)) {
1419 /* Before trying the cache, let's make sure we figured out a
1420 * server to use. Should this cause a change of server this
1421 * might flush the cache. */
1422 (void) dns_scope_get_dns_server(t
->scope
);
1424 /* Let's then prune all outdated entries */
1425 dns_cache_prune(&t
->scope
->cache
);
1427 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1431 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1432 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1433 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1435 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1443 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1445 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1446 bool add_known_answers
= false;
1447 DnsTransaction
*other
;
1449 DnsResourceKey
*tkey
;
1450 _cleanup_set_free_ Set
*keys
= NULL
;
1452 unsigned nscount
= 0;
1457 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1459 /* Discard any previously prepared packet, so we can start over and coalesce again */
1460 t
->sent
= dns_packet_unref(t
->sent
);
1462 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1466 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1472 if (dns_key_is_shared(t
->key
))
1473 add_known_answers
= true;
1475 if (t
->key
->type
== DNS_TYPE_ANY
) {
1476 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1480 r
= set_put(keys
, t
->key
);
1486 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1487 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1488 * in our current scope, and see whether their timing contraints allow them to be sent.
1491 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1493 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1495 /* Skip ourselves */
1499 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1502 if (other
->next_attempt_after
> ts
)
1505 if (qdcount
>= UINT16_MAX
)
1508 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1511 * If we can't stuff more questions into the packet, just give up.
1512 * One of the 'other' transactions will fire later and take care of the rest.
1520 r
= dns_transaction_prepare(other
, ts
);
1524 ts
+= transaction_get_resend_timeout(other
);
1526 r
= sd_event_add_time(
1527 other
->scope
->manager
->event
,
1528 &other
->timeout_event_source
,
1529 clock_boottime_or_monotonic(),
1531 on_transaction_timeout
, other
);
1535 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1537 other
->state
= DNS_TRANSACTION_PENDING
;
1538 other
->next_attempt_after
= ts
;
1542 if (dns_key_is_shared(other
->key
))
1543 add_known_answers
= true;
1545 if (other
->key
->type
== DNS_TYPE_ANY
) {
1546 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1550 r
= set_put(keys
, other
->key
);
1556 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1558 /* Append known answer section if we're asking for any shared record */
1559 if (add_known_answers
) {
1560 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1565 SET_FOREACH(tkey
, keys
, i
) {
1566 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1569 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1573 r
= dns_packet_append_answer(p
, answer
);
1577 nscount
+= dns_answer_size(answer
);
1579 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1581 t
->sent
= TAKE_PTR(p
);
1586 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1587 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1592 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1593 return dns_transaction_make_packet_mdns(t
);
1598 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1602 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1606 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1607 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1609 t
->sent
= TAKE_PTR(p
);
1614 int dns_transaction_go(DnsTransaction
*t
) {
1617 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1621 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1624 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1626 r
= dns_transaction_prepare(t
, ts
);
1630 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1632 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1633 dns_protocol_to_string(t
->scope
->protocol
),
1634 t
->scope
->link
? t
->scope
->link
->name
: "*",
1635 af_to_name_short(t
->scope
->family
));
1637 if (!t
->initial_jitter_scheduled
&&
1638 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1639 usec_t jitter
, accuracy
;
1641 /* RFC 4795 Section 2.7 suggests all queries should be
1642 * delayed by a random time from 0 to JITTER_INTERVAL. */
1644 t
->initial_jitter_scheduled
= true;
1646 random_bytes(&jitter
, sizeof(jitter
));
1648 switch (t
->scope
->protocol
) {
1650 case DNS_PROTOCOL_LLMNR
:
1651 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1652 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1655 case DNS_PROTOCOL_MDNS
:
1656 jitter
%= MDNS_JITTER_RANGE_USEC
;
1657 jitter
+= MDNS_JITTER_MIN_USEC
;
1658 accuracy
= MDNS_JITTER_RANGE_USEC
;
1661 assert_not_reached("bad protocol");
1664 r
= sd_event_add_time(
1665 t
->scope
->manager
->event
,
1666 &t
->timeout_event_source
,
1667 clock_boottime_or_monotonic(),
1668 ts
+ jitter
, accuracy
,
1669 on_transaction_timeout
, t
);
1673 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1676 t
->next_attempt_after
= ts
;
1677 t
->state
= DNS_TRANSACTION_PENDING
;
1679 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1683 /* Otherwise, we need to ask the network */
1684 r
= dns_transaction_make_packet(t
);
1688 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1689 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1690 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1692 /* RFC 4795, Section 2.4. says reverse lookups shall
1693 * always be made via TCP on LLMNR */
1694 r
= dns_transaction_emit_tcp(t
);
1696 /* Try via UDP, and if that fails due to large size or lack of
1697 * support try via TCP */
1698 r
= dns_transaction_emit_udp(t
);
1700 log_debug("Sending query via TCP since it is too large.");
1701 else if (r
== -EAGAIN
)
1702 log_debug("Sending query via TCP since server doesn't support UDP.");
1703 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1704 r
= dns_transaction_emit_tcp(t
);
1708 /* No servers to send this to? */
1709 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1712 if (r
== -EOPNOTSUPP
) {
1713 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1714 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1717 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1718 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1719 * answer this request with this protocol. */
1720 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1724 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1727 /* Couldn't send? Try immediately again, with a new server */
1728 dns_scope_next_dns_server(t
->scope
);
1730 return dns_transaction_go(t
);
1733 ts
+= transaction_get_resend_timeout(t
);
1735 r
= sd_event_add_time(
1736 t
->scope
->manager
->event
,
1737 &t
->timeout_event_source
,
1738 clock_boottime_or_monotonic(),
1740 on_transaction_timeout
, t
);
1744 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1746 t
->state
= DNS_TRANSACTION_PENDING
;
1747 t
->next_attempt_after
= ts
;
1752 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1760 /* Try to find cyclic dependencies between transaction objects */
1765 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1766 r
= dns_transaction_find_cyclic(t
, n
);
1774 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1775 DnsTransaction
*aux
;
1782 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1784 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1788 if (set_contains(t
->dnssec_transactions
, aux
)) {
1793 r
= dns_transaction_find_cyclic(t
, aux
);
1797 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1799 log_debug("Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1801 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1803 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1809 r
= set_ensure_allocated(&t
->dnssec_transactions
, NULL
);
1813 r
= set_ensure_allocated(&aux
->notify_transactions
, NULL
);
1817 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1821 r
= set_put(t
->dnssec_transactions
, aux
);
1825 r
= set_put(aux
->notify_transactions
, t
);
1827 (void) set_remove(t
->dnssec_transactions
, aux
);
1835 dns_transaction_gc(aux
);
1839 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1840 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1841 DnsTransaction
*aux
;
1847 /* Try to get the data from the trust anchor */
1848 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1852 r
= dns_answer_extend(&t
->validated_keys
, a
);
1859 /* This didn't work, ask for it via the network/cache then. */
1860 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1861 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1866 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1867 r
= dns_transaction_go(aux
);
1875 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1880 /* Check whether the specified name is in the NTA
1881 * database, either in the global one, or the link-local
1884 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1888 if (!t
->scope
->link
)
1891 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1894 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1899 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1900 * RRs to prove it */
1902 r
= dns_transaction_has_positive_answer(t
, NULL
);
1908 /* Is this key explicitly listed as a negative trust anchor?
1909 * If so, it's nothing we need to care about */
1910 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1916 /* The answer does not contain any RRs that match to the
1917 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1918 * included. If not, the answer is unsigned. */
1920 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1929 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1935 /* Check if the specified RR is the "primary" response,
1936 * i.e. either matches the question precisely or is a
1937 * CNAME/DNAME for it. */
1939 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1943 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1946 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1949 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1950 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1952 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1955 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1956 * be supported, hence return true. */
1960 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1961 * the server is known to support currently, as the transaction feature level might be lower than what the
1962 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1963 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1965 return dns_server_dnssec_supported(t
->server
);
1968 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1974 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1976 if (!dns_transaction_dnssec_supported(t
))
1979 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1980 if (!dns_transaction_dnssec_supported(dt
))
1986 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
1987 DnsResourceRecord
*rr
;
1994 * Retrieve all auxiliary RRs for the answer we got, so that
1995 * we can verify signatures or prove that RRs are rightfully
1996 * unsigned. Specifically:
1998 * - For RRSIG we get the matching DNSKEY
1999 * - For DNSKEY we get the matching DS
2000 * - For unsigned SOA/NS we get the matching DS
2001 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2002 * - For other unsigned RRs we get the matching SOA RR
2003 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2004 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2005 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2008 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2010 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2011 return 0; /* We only need to validate stuff from the network */
2012 if (!dns_transaction_dnssec_supported(t
))
2013 return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */
2015 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2017 if (dns_type_is_pseudo(rr
->key
->type
))
2020 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2021 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2027 switch (rr
->key
->type
) {
2029 case DNS_TYPE_RRSIG
: {
2030 /* For each RRSIG we request the matching DNSKEY */
2031 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2033 /* If this RRSIG is about a DNSKEY RR and the
2034 * signer is the same as the owner, then we
2035 * already have the DNSKEY, and we don't have
2036 * to look for more. */
2037 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2038 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2045 /* If the signer is not a parent of our
2046 * original query, then this is about an
2047 * auxiliary RRset, but not anything we asked
2048 * for. In this case we aren't interested,
2049 * because we don't want to request additional
2050 * RRs for stuff we didn't really ask for, and
2051 * also to avoid request loops, where
2052 * additional RRs from one transaction result
2053 * in another transaction whose additonal RRs
2054 * point back to the original transaction, and
2056 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2062 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2066 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2067 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2068 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2074 case DNS_TYPE_DNSKEY
: {
2075 /* For each DNSKEY we request the matching DS */
2076 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2078 /* If the DNSKEY we are looking at is not for
2079 * zone we are interested in, nor any of its
2080 * parents, we aren't interested, and don't
2081 * request it. After all, we don't want to end
2082 * up in request loops, and want to keep
2083 * additional traffic down. */
2085 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2091 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2095 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2096 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2097 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2106 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2108 /* For an unsigned SOA or NS, try to acquire
2109 * the matching DS RR, as we are at a zone cut
2110 * then, and whether a DS exists tells us
2111 * whether the zone is signed. Do so only if
2112 * this RR matches our original question,
2115 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2119 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2120 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2121 * If so, we need to validate it, too. */
2123 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2126 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2131 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2137 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2141 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2142 t
->id
, dns_resource_key_name(rr
->key
));
2143 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2151 case DNS_TYPE_CNAME
:
2152 case DNS_TYPE_DNAME
: {
2153 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2156 /* CNAMEs and DNAMEs cannot be located at a
2157 * zone apex, hence ask for the parent SOA for
2158 * unsigned CNAME/DNAME RRs, maybe that's the
2159 * apex. But do all that only if this is
2160 * actually a response to our original
2163 * Similar for DS RRs, which are signed when
2164 * the parent SOA is signed. */
2166 r
= dns_transaction_is_primary_response(t
, rr
);
2172 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2178 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2184 name
= dns_resource_key_name(rr
->key
);
2185 r
= dns_name_parent(&name
);
2191 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2195 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2196 t
->id
, dns_resource_key_name(rr
->key
));
2197 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2205 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2207 /* For other unsigned RRsets (including
2208 * NSEC/NSEC3!), look for proof the zone is
2209 * unsigned, by requesting the SOA RR of the
2210 * zone. However, do so only if they are
2211 * directly relevant to our original
2214 r
= dns_transaction_is_primary_response(t
, rr
);
2220 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2226 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2230 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2231 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2232 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2239 /* Above, we requested everything necessary to validate what
2240 * we got. Now, let's request what we need to validate what we
2243 r
= dns_transaction_has_unsigned_negative_answer(t
);
2250 name
= dns_resource_key_name(t
->key
);
2252 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2253 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2254 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2255 * though they have further children. If this was a DS request, then it's signed when the parent zone
2256 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2257 * to see if that is signed. */
2259 if (t
->key
->type
== DNS_TYPE_DS
) {
2260 r
= dns_name_parent(&name
);
2262 type
= DNS_TYPE_SOA
;
2263 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2264 t
->id
, dns_resource_key_name(t
->key
));
2268 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2271 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2272 t
->id
, dns_resource_key_name(t
->key
));
2275 type
= DNS_TYPE_SOA
;
2276 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2277 t
->id
, dns_resource_key_name(t
->key
));
2281 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2283 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2287 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2293 return dns_transaction_dnssec_is_live(t
);
2296 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2300 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2301 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2302 the state is VALIDATING however, we should check if we are complete now. */
2304 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2305 dns_transaction_process_dnssec(t
);
2308 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2309 DnsResourceRecord
*rr
;
2314 /* Add all DNSKEY RRs from the answer that are validated by DS
2315 * RRs from the list of validated keys to the list of
2316 * validated keys. */
2318 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2320 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2326 /* If so, the DNSKEY is validated too. */
2327 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2335 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2341 /* Checks if the RR we are looking for must be signed with an
2342 * RRSIG. This is used for positive responses. */
2344 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2347 if (dns_type_is_pseudo(rr
->key
->type
))
2350 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2356 switch (rr
->key
->type
) {
2358 case DNS_TYPE_RRSIG
:
2359 /* RRSIGs are the signatures themselves, they need no signing. */
2367 /* For SOA or NS RRs we look for a matching DS transaction */
2369 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2371 if (dt
->key
->class != rr
->key
->class)
2373 if (dt
->key
->type
!= DNS_TYPE_DS
)
2376 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2382 /* We found a DS transactions for the SOA/NS
2383 * RRs we are looking at. If it discovered signed DS
2384 * RRs, then we need to be signed, too. */
2386 if (!dt
->answer_authenticated
)
2389 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2392 /* We found nothing that proves this is safe to leave
2393 * this unauthenticated, hence ask inist on
2394 * authentication. */
2399 case DNS_TYPE_CNAME
:
2400 case DNS_TYPE_DNAME
: {
2401 const char *parent
= NULL
;
2406 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2408 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2411 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2413 if (dt
->key
->class != rr
->key
->class)
2415 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2419 parent
= dns_resource_key_name(rr
->key
);
2420 r
= dns_name_parent(&parent
);
2424 if (rr
->key
->type
== DNS_TYPE_DS
)
2427 /* A CNAME/DNAME without a parent? That's sooo weird. */
2428 log_debug("Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2433 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2439 return t
->answer_authenticated
;
2449 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2451 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2453 if (dt
->key
->class != rr
->key
->class)
2455 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2458 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2464 /* We found the transaction that was supposed to find
2465 * the SOA RR for us. It was successful, but found no
2466 * RR for us. This means we are not at a zone cut. In
2467 * this case, we require authentication if the SOA
2468 * lookup was authenticated too. */
2469 return t
->answer_authenticated
;
2476 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2482 /* If DNSSEC downgrade mode is on, checks whether the
2483 * specified RR is one level below a TLD we have proven not to
2484 * exist. In such a case we assume that this is a private
2485 * domain, and permit it.
2487 * This detects cases like the Fritz!Box router networks. Each
2488 * Fritz!Box router serves a private "fritz.box" zone, in the
2489 * non-existing TLD "box". Requests for the "fritz.box" domain
2490 * are served by the router itself, while requests for the
2491 * "box" domain will result in NXDOMAIN.
2493 * Note that this logic is unable to detect cases where a
2494 * router serves a private DNS zone directly under
2495 * non-existing TLD. In such a case we cannot detect whether
2496 * the TLD is supposed to exist or not, as all requests we
2497 * make for it will be answered by the router's zone, and not
2498 * by the root zone. */
2502 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2503 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2505 tld
= dns_resource_key_name(key
);
2506 r
= dns_name_parent(&tld
);
2510 return false; /* Already the root domain */
2512 if (!dns_name_is_single_label(tld
))
2515 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2517 if (dt
->key
->class != key
->class)
2520 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2526 /* We found an auxiliary lookup we did for the TLD. If
2527 * that returned with NXDOMAIN, we know the TLD didn't
2528 * exist, and hence this might be a private zone. */
2530 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2536 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2537 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2546 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2547 * this negative reply */
2549 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2552 if (dns_type_is_pseudo(t
->key
->type
))
2555 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2561 r
= dns_transaction_in_private_tld(t
, t
->key
);
2565 /* The lookup is from a TLD that is proven not to
2566 * exist, and we are in downgrade mode, hence ignore
2567 * that fact that we didn't get any NSEC RRs. */
2569 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2570 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2574 name
= dns_resource_key_name(t
->key
);
2576 if (t
->key
->type
== DNS_TYPE_DS
) {
2578 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2579 * hence check the parent SOA in this case. */
2581 r
= dns_name_parent(&name
);
2587 type
= DNS_TYPE_SOA
;
2589 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2590 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2593 /* For all other negative replies, check for the SOA lookup */
2594 type
= DNS_TYPE_SOA
;
2596 /* For all other RRs we check the SOA on the same level to see
2597 * if it's signed. */
2599 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2601 if (dt
->key
->class != t
->key
->class)
2603 if (dt
->key
->type
!= type
)
2606 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2612 return dt
->answer_authenticated
;
2615 /* If in doubt, require NSEC/NSEC3 */
2619 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2620 DnsResourceRecord
*rrsig
;
2624 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2625 * the specified RRset is authenticated (i.e. has a matching
2628 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2634 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2638 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2644 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2646 if (dt
->key
->class != rr
->key
->class)
2649 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2651 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2657 /* OK, we found an auxiliary DNSKEY
2658 * lookup. If that lookup is
2659 * authenticated, report this. */
2661 if (dt
->answer_authenticated
)
2666 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2668 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2674 /* OK, we found an auxiliary DS
2675 * lookup. If that lookup is
2676 * authenticated and non-zero, we
2679 if (!dt
->answer_authenticated
)
2682 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2687 return found
? false : -ENXIO
;
2690 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2694 /* We know that the root domain is signed, hence if it appears
2695 * not to be signed, there's a problem with the DNS server */
2697 return rr
->key
->class == DNS_CLASS_IN
&&
2698 dns_name_is_root(dns_resource_key_name(rr
->key
));
2701 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2702 DnsResourceRecord
*rr
;
2707 /* Maybe warn the user that we encountered a revoked DNSKEY
2708 * for a key from our trust anchor. Note that we don't care
2709 * whether the DNSKEY can be authenticated or not. It's
2710 * sufficient if it is self-signed. */
2712 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2713 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2721 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2727 /* Removes all DNSKEY/DS objects from t->validated_keys that
2728 * our trust anchors database considers revoked. */
2731 DnsResourceRecord
*rr
;
2735 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2736 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2740 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2754 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2761 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2763 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2765 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2768 if (!dt
->answer_authenticated
)
2771 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2780 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2781 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2782 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2785 static int dnssec_validate_records(
2789 DnsAnswer
**validated
) {
2791 DnsResourceRecord
*rr
;
2794 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2796 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2797 DnsResourceRecord
*rrsig
= NULL
;
2798 DnssecResult result
;
2800 switch (rr
->key
->type
) {
2801 case DNS_TYPE_RRSIG
:
2804 case DNS_TYPE_DNSKEY
:
2805 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2806 if (phase
== DNSSEC_PHASE_NSEC
)
2811 case DNS_TYPE_NSEC3
:
2814 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2815 if (phase
== DNSSEC_PHASE_DNSKEY
)
2820 /* We validate all other RRs only in the ALL phases */
2821 if (phase
!= DNSSEC_PHASE_ALL
)
2825 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2829 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2831 if (result
== DNSSEC_VALIDATED
) {
2833 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2834 /* If we just validated a DNSKEY RRset, then let's add these keys to
2835 * the set of validated keys for this transaction. */
2837 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2841 /* Some of the DNSKEYs we just added might already have been revoked,
2842 * remove them again in that case. */
2843 r
= dns_transaction_invalidate_revoked_keys(t
);
2848 /* Add the validated RRset to the new list of validated
2849 * RRsets, and remove it from the unvalidated RRsets.
2850 * We mark the RRset as authenticated and cacheable. */
2851 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2855 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2857 /* Exit the loop, we dropped something from the answer, start from the beginning */
2861 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2862 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2863 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2864 if (phase
!= DNSSEC_PHASE_ALL
)
2867 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2868 bool authenticated
= false;
2871 /* This RRset validated, but as a wildcard. This means we need
2872 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2874 /* First step, determine the source of synthesis */
2875 r
= dns_resource_record_source(rrsig
, &source
);
2879 r
= dnssec_test_positive_wildcard(*validated
,
2880 dns_resource_key_name(rr
->key
),
2882 rrsig
->rrsig
.signer
,
2885 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2887 result
= DNSSEC_INVALID
;
2889 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2890 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2894 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2896 /* Exit the loop, we dropped something from the answer, start from the beginning */
2901 if (result
== DNSSEC_NO_SIGNATURE
) {
2902 r
= dns_transaction_requires_rrsig(t
, rr
);
2906 /* Data does not require signing. In that case, just copy it over,
2907 * but remember that this is by no means authenticated. */
2908 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2912 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2916 r
= dns_transaction_known_signed(t
, rr
);
2920 /* This is an RR we know has to be signed. If it isn't this means
2921 * the server is not attaching RRSIGs, hence complain. */
2923 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2925 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2927 /* Downgrading is OK? If so, just consider the information unsigned */
2929 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2933 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2937 /* Otherwise, fail */
2938 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2942 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2946 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2948 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2949 * mode, hence ignore the fact that this was not signed. */
2951 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2952 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2954 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2958 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2965 DNSSEC_SIGNATURE_EXPIRED
,
2966 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2968 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2969 if (r
< 0 && r
!= -ENXIO
)
2972 /* The DNSKEY transaction was not authenticated, this means there's
2973 * no DS for this, which means it's OK if no keys are found for this signature. */
2975 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2979 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2984 r
= dns_transaction_is_primary_response(t
, rr
);
2988 /* Look for a matching DNAME for this CNAME */
2989 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2993 /* Also look among the stuff we already validated */
2994 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3002 DNSSEC_SIGNATURE_EXPIRED
,
3003 DNSSEC_NO_SIGNATURE
))
3004 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3005 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3006 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3008 /* This is a primary response to our question, and it failed validation.
3010 t
->answer_dnssec_result
= result
;
3014 /* This is a primary response, but we do have a DNAME RR
3015 * in the RR that can replay this CNAME, hence rely on
3016 * that, and we can remove the CNAME in favour of it. */
3019 /* This is just some auxiliary data. Just remove the RRset and continue. */
3020 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3024 /* We dropped something from the answer, start from the beginning. */
3028 return 2; /* Finito. */
3031 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3032 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3034 DnsAnswerFlags flags
;
3036 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3040 /* We have now collected all DS and DNSKEY RRs in
3041 * t->validated_keys, let's see which RRs we can now
3042 * authenticate with that. */
3044 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3047 /* Already validated */
3048 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3051 /* Our own stuff needs no validation */
3052 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3053 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3054 t
->answer_authenticated
= true;
3058 /* Cached stuff is not affected by validation. */
3059 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3062 if (!dns_transaction_dnssec_supported_full(t
)) {
3063 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3064 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3065 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3069 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3071 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3073 /* First, see if this response contains any revoked trust
3074 * anchors we care about */
3075 r
= dns_transaction_check_revoked_trust_anchors(t
);
3079 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3080 r
= dns_transaction_copy_validated(t
);
3084 /* Second, see if there are DNSKEYs we already know a
3085 * validated DS for. */
3086 r
= dns_transaction_validate_dnskey_by_ds(t
);
3090 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3091 * anchor says are revoked. After all we might have marked
3092 * some keys revoked above, but they might still be lingering
3093 * in our validated_keys list. */
3094 r
= dns_transaction_invalidate_revoked_keys(t
);
3098 phase
= DNSSEC_PHASE_DNSKEY
;
3100 bool have_nsec
= false;
3102 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3106 /* Try again as long as we managed to achieve something */
3110 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3111 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3112 phase
= DNSSEC_PHASE_NSEC
;
3116 if (phase
!= DNSSEC_PHASE_ALL
) {
3117 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3118 * Note that in this third phase we start to remove RRs we couldn't validate. */
3119 phase
= DNSSEC_PHASE_ALL
;
3127 dns_answer_unref(t
->answer
);
3128 t
->answer
= TAKE_PTR(validated
);
3130 /* At this point the answer only contains validated
3131 * RRsets. Now, let's see if it actually answers the question
3132 * we asked. If so, great! If it doesn't, then see if
3133 * NSEC/NSEC3 can prove this. */
3134 r
= dns_transaction_has_positive_answer(t
, &flags
);
3136 /* Yes, it answers the question! */
3138 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3139 /* The answer is fully authenticated, yay. */
3140 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3141 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3142 t
->answer_authenticated
= true;
3144 /* The answer is not fully authenticated. */
3145 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3146 t
->answer_authenticated
= false;
3149 } else if (r
== 0) {
3150 DnssecNsecResult nr
;
3151 bool authenticated
= false;
3153 /* Bummer! Let's check NSEC/NSEC3 */
3154 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3160 case DNSSEC_NSEC_NXDOMAIN
:
3161 /* NSEC proves the domain doesn't exist. Very good. */
3162 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3163 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3164 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3165 t
->answer_authenticated
= authenticated
;
3167 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3170 case DNSSEC_NSEC_NODATA
:
3171 /* NSEC proves that there's no data here, very good. */
3172 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3173 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3174 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3175 t
->answer_authenticated
= authenticated
;
3177 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3180 case DNSSEC_NSEC_OPTOUT
:
3181 /* NSEC3 says the data might not be signed */
3182 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3183 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3184 t
->answer_authenticated
= false;
3186 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3189 case DNSSEC_NSEC_NO_RR
:
3190 /* No NSEC data? Bummer! */
3192 r
= dns_transaction_requires_nsec(t
);
3196 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3197 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3199 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3200 t
->answer_authenticated
= false;
3201 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3206 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3207 /* We don't know the NSEC3 algorithm used? */
3208 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3209 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3212 case DNSSEC_NSEC_FOUND
:
3213 case DNSSEC_NSEC_CNAME
:
3214 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3215 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3216 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3220 assert_not_reached("Unexpected NSEC result.");
3227 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3228 [DNS_TRANSACTION_NULL
] = "null",
3229 [DNS_TRANSACTION_PENDING
] = "pending",
3230 [DNS_TRANSACTION_VALIDATING
] = "validating",
3231 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3232 [DNS_TRANSACTION_SUCCESS
] = "success",
3233 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3234 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3235 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3236 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3237 [DNS_TRANSACTION_ERRNO
] = "errno",
3238 [DNS_TRANSACTION_ABORTED
] = "aborted",
3239 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3240 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3241 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3242 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3243 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3245 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3247 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3248 [DNS_TRANSACTION_NETWORK
] = "network",
3249 [DNS_TRANSACTION_CACHE
] = "cache",
3250 [DNS_TRANSACTION_ZONE
] = "zone",
3251 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3253 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);