1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #include "sd-messages.h"
6 #include "alloc-util.h"
7 #include "dns-domain.h"
8 #include "errno-list.h"
9 #include "errno-util.h"
11 #include "random-util.h"
12 #include "resolved-dns-cache.h"
13 #include "resolved-dns-transaction.h"
14 #include "resolved-dnstls.h"
15 #include "resolved-llmnr.h"
16 #include "string-table.h"
18 #define TRANSACTIONS_MAX 4096
19 #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
21 /* After how much time to repeat classic DNS requests */
22 #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX)
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
->ifname
: "*",
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", strna(dns_server_string_full(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
->ifname
: "*",
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.", strna(dns_server_string_full(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
);
466 dns_transaction_retry(t
, true);
470 t
->answer_errno
= error
;
471 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
475 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
479 dns_transaction_close_connection(t
);
481 if (dns_packet_validate_reply(p
) <= 0) {
482 log_debug("Invalid TCP reply packet.");
483 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
487 dns_scope_check_conflicts(t
->scope
, p
);
490 dns_transaction_process_reply(t
, p
);
493 /* If the response wasn't useful, then complete the transition
494 * now. After all, we are the worst feature set now with TCP
495 * sockets, and there's really no point in retrying. */
496 if (t
->state
== DNS_TRANSACTION_PENDING
)
497 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
499 dns_transaction_gc(t
);
504 static int on_stream_complete(DnsStream
*s
, int error
) {
507 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
508 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
510 if (s
->transactions
) {
514 dns_server_packet_lost(t
->server
, IPPROTO_TCP
, t
->current_feature_level
);
519 DnsTransaction
*t
, *n
;
521 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
522 on_transaction_stream_error(t
, error
);
528 static int on_stream_packet(DnsStream
*s
) {
529 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
534 /* Take ownership of packet to be able to receive new packets */
535 p
= dns_stream_take_read_packet(s
);
538 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
540 return dns_transaction_on_stream_packet(t
, p
);
542 /* Ignore incorrect transaction id as an old transaction can have been canceled. */
543 log_debug("Received unexpected TCP reply packet with id %" PRIu16
", ignoring.", DNS_PACKET_ID(p
));
547 static uint16_t dns_transaction_port(DnsTransaction
*t
) {
548 if (t
->server
->port
> 0)
549 return t
->server
->port
;
550 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) ? 853 : 53;
553 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
554 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
555 _cleanup_close_
int fd
= -1;
556 union sockaddr_union sa
;
562 dns_transaction_close_connection(t
);
564 switch (t
->scope
->protocol
) {
566 case DNS_PROTOCOL_DNS
:
567 r
= dns_transaction_pick_server(t
);
571 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
574 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
578 if (t
->server
->stream
&& (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) == t
->server
->stream
->encrypted
))
579 s
= dns_stream_ref(t
->server
->stream
);
581 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, dns_transaction_port(t
), &sa
);
583 type
= DNS_STREAM_LOOKUP
;
586 case DNS_PROTOCOL_LLMNR
:
587 /* When we already received a reply to this (but it was truncated), send to its sender address */
589 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
, &sa
);
591 union in_addr_union address
;
592 int family
= AF_UNSPEC
;
594 /* Otherwise, try to talk to the owner of a
595 * the IP address, in case this is a reverse
598 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
603 if (family
!= t
->scope
->family
)
606 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
, &sa
);
609 type
= DNS_STREAM_LLMNR_SEND
;
613 return -EAFNOSUPPORT
;
620 r
= dns_stream_new(t
->scope
->manager
, &s
, type
, t
->scope
->protocol
, fd
, &sa
);
626 #if ENABLE_DNS_OVER_TLS
627 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
&&
628 DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
)) {
631 r
= dnstls_stream_connect_tls(s
, t
->server
);
638 dns_server_unref_stream(t
->server
);
639 s
->server
= dns_server_ref(t
->server
);
640 t
->server
->stream
= dns_stream_ref(s
);
643 s
->complete
= on_stream_complete
;
644 s
->on_packet
= on_stream_packet
;
646 /* The interface index is difficult to determine if we are
647 * connecting to the local host, hence fill this in right away
648 * instead of determining it from the socket */
649 s
->ifindex
= dns_scope_ifindex(t
->scope
);
652 t
->stream
= TAKE_PTR(s
);
653 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
655 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
657 dns_transaction_close_connection(t
);
661 dns_transaction_reset_answer(t
);
663 t
->tried_stream
= true;
668 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
671 /* For mDNS we cache whenever we get the packet, rather than
672 * in each transaction. */
673 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
676 /* Caching disabled? */
677 if (t
->scope
->manager
->enable_cache
== DNS_CACHE_MODE_NO
)
680 /* We never cache if this packet is from the local host, under
681 * the assumption that a locally running DNS server would
682 * cache this anyway, and probably knows better when to flush
683 * the cache then we could. */
684 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
687 dns_cache_put(&t
->scope
->cache
,
688 t
->scope
->manager
->enable_cache
,
692 t
->answer_authenticated
,
696 &t
->received
->sender
);
699 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
705 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
706 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
712 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
718 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
719 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
721 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
725 case DNS_TRANSACTION_NULL
:
726 case DNS_TRANSACTION_PENDING
:
727 case DNS_TRANSACTION_VALIDATING
:
731 case DNS_TRANSACTION_RCODE_FAILURE
:
732 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
733 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
737 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
738 * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
739 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
740 * RRs to make unsigned proofs. */
742 case DNS_TRANSACTION_SUCCESS
:
746 case DNS_TRANSACTION_DNSSEC_FAILED
:
747 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
748 * validationr result */
750 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
751 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
752 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
756 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
761 /* All is ready, we can go and validate */
765 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
766 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
770 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
775 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
776 r
= dns_transaction_dnssec_ready(t
);
779 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
782 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
783 * restart the lookup immediately. */
784 r
= dns_transaction_maybe_restart(t
);
787 if (r
> 0) /* Transaction got restarted... */
790 /* All our auxiliary DNSSEC transactions are complete now. Try
791 * to validate our RRset now. */
792 r
= dns_transaction_validate_dnssec(t
);
794 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
800 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
801 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
803 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
806 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
807 /* We tried fewer servers on this transaction than we know, let's try another one then */
808 dns_transaction_retry(t
, true);
812 /* OK, let's give up, apparently all servers we tried didn't work. */
813 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
817 if (!IN_SET(t
->answer_dnssec_result
,
818 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
819 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
820 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
821 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
822 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
826 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
827 dns_server_warn_downgrade(t
->server
);
829 dns_transaction_cache_answer(t
);
831 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
832 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
834 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
839 t
->answer_errno
= -r
;
840 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
843 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
848 /* Checks whether the answer is positive, i.e. either a direct
849 * answer to the question, or a CNAME/DNAME for it */
851 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
855 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
862 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
867 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
868 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
869 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
870 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
871 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
872 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
873 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
874 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
875 * incomplete CNAME/DNAME chain.
877 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
878 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
881 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
884 r
= dns_transaction_has_positive_answer(t
, NULL
);
888 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
892 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
899 assert(t
->scope
->manager
);
901 if (t
->state
!= DNS_TRANSACTION_PENDING
)
904 /* Note that this call might invalidate the query. Callers
905 * should hence not attempt to access the query or transaction
906 * after calling this function. */
908 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
909 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
911 switch (t
->scope
->protocol
) {
913 case DNS_PROTOCOL_LLMNR
:
914 /* For LLMNR we will not accept any packets from other interfaces */
916 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
919 if (p
->family
!= t
->scope
->family
)
922 /* Tentative packets are not full responses but still
923 * useful for identifying uniqueness conflicts during
925 if (DNS_PACKET_LLMNR_T(p
)) {
926 dns_transaction_tentative(t
, p
);
932 case DNS_PROTOCOL_MDNS
:
933 /* For mDNS we will not accept any packets from other interfaces */
935 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
938 if (p
->family
!= t
->scope
->family
)
943 case DNS_PROTOCOL_DNS
:
944 /* Note that we do not need to verify the
945 * addresses/port numbers of incoming traffic, as we
946 * invoked connect() on our UDP socket in which case
947 * the kernel already does the needed verification for
952 assert_not_reached("Invalid DNS protocol.");
955 if (t
->received
!= p
) {
956 dns_packet_unref(t
->received
);
957 t
->received
= dns_packet_ref(p
);
960 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
962 if (p
->ipproto
== IPPROTO_TCP
) {
963 if (DNS_PACKET_TC(p
)) {
964 /* Truncated via TCP? Somebody must be fucking with us */
965 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
969 if (DNS_PACKET_ID(p
) != t
->id
) {
970 /* Not the reply to our query? Somebody must be fucking with us */
971 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
976 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
978 switch (t
->scope
->protocol
) {
980 case DNS_PROTOCOL_DNS
:
983 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
985 /* Request failed, immediately try again with reduced features */
987 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
989 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
990 * this transaction anymore, but let's see if it might make sense to send the request
991 * to a different DNS server instead. If not let's process the response, and accept the
992 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
993 * packet loss, but is not going to give us better rcodes should we actually have
994 * managed to get them already at UDP level. */
996 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
997 /* We tried fewer servers on this transaction than we know, let's try another one then */
998 dns_transaction_retry(t
, true);
1002 /* Give up, accept the rcode */
1003 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1007 /* Reduce this feature level by one and try again. */
1008 switch (t
->current_feature_level
) {
1009 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1010 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1012 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1013 /* Skip plain TLS when TLS is not supported */
1014 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1017 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1020 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1021 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1022 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1024 dns_transaction_retry(t
, false /* use the same server */);
1028 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1029 /* This server refused our request? If so, try again, use a different server */
1030 log_debug("Server returned REFUSED, switching servers, and retrying.");
1031 dns_transaction_retry(t
, true /* pick a new server */);
1035 if (DNS_PACKET_TC(p
))
1036 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1040 case DNS_PROTOCOL_LLMNR
:
1041 case DNS_PROTOCOL_MDNS
:
1042 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1046 assert_not_reached("Invalid DNS protocol.");
1049 if (DNS_PACKET_TC(p
)) {
1051 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1052 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1053 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1057 log_debug("Reply truncated, retrying via TCP.");
1059 /* Response was truncated, let's try again with good old TCP */
1060 r
= dns_transaction_emit_tcp(t
);
1062 /* No servers found? Damn! */
1063 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1066 if (r
== -EOPNOTSUPP
) {
1067 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1068 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1072 /* On LLMNR, if we cannot connect to the host,
1073 * we immediately give up */
1074 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1077 /* On DNS, couldn't send? Try immediately again, with a new server */
1078 dns_transaction_retry(t
, true);
1084 /* After the superficial checks, actually parse the message. */
1085 r
= dns_packet_extract(p
);
1087 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1092 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1093 * rcode and subsequently downgraded the protocol */
1095 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1096 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1097 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1099 /* Report that the OPT RR was missing */
1101 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1103 /* Report that we successfully received a packet */
1104 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1107 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1108 r
= dns_transaction_maybe_restart(t
);
1111 if (r
> 0) /* Transaction got restarted... */
1114 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1116 /* When dealing with protocols other than mDNS only consider responses with
1117 * equivalent query section to the request. For mDNS this check doesn't make
1118 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1119 * contain any questions in the Question Section". */
1120 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1121 r
= dns_packet_is_reply_for(p
, t
->key
);
1125 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1130 /* Install the answer as answer to the transaction */
1131 dns_answer_unref(t
->answer
);
1132 t
->answer
= dns_answer_ref(p
->answer
);
1133 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1134 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1135 t
->answer_authenticated
= false;
1137 r
= dns_transaction_fix_rcode(t
);
1141 /* Block GC while starting requests for additional DNSSEC RRs */
1143 r
= dns_transaction_request_dnssec_keys(t
);
1146 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1147 if (!dns_transaction_gc(t
))
1150 /* Requesting additional keys might have resulted in
1151 * this transaction to fail, since the auxiliary
1152 * request failed for some reason. If so, we are not
1153 * in pending state anymore, and we should exit
1155 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1160 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1161 t
->state
= DNS_TRANSACTION_VALIDATING
;
1162 dns_transaction_close_connection(t
);
1163 dns_transaction_stop_timeout(t
);
1168 dns_transaction_process_dnssec(t
);
1172 t
->answer_errno
= -r
;
1173 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1176 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1177 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1178 DnsTransaction
*t
= userdata
;
1184 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1185 if (ERRNO_IS_DISCONNECT(-r
)) {
1188 /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the
1189 * next recvmsg(). Treat this like a lost packet. */
1191 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1192 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1193 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1195 dns_transaction_retry(t
, true);
1199 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1200 t
->answer_errno
= -r
;
1204 /* Spurious wakeup without any data */
1207 r
= dns_packet_validate_reply(p
);
1209 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1213 log_debug("Received inappropriate DNS packet as response, ignoring.");
1217 if (DNS_PACKET_ID(p
) != t
->id
) {
1218 log_debug("Received packet with incorrect transaction ID, ignoring.");
1222 dns_transaction_process_reply(t
, p
);
1226 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1231 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1233 r
= dns_transaction_pick_server(t
);
1237 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1238 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1240 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1243 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1246 dns_transaction_close_connection(t
);
1248 fd
= dns_scope_socket_udp(t
->scope
, t
->server
);
1252 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1258 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1262 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1266 dns_transaction_close_connection(t
);
1268 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1272 dns_transaction_reset_answer(t
);
1277 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1278 DnsTransaction
*t
= userdata
;
1283 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1284 /* Timeout reached? Increase the timeout for the server used */
1285 switch (t
->scope
->protocol
) {
1287 case DNS_PROTOCOL_DNS
:
1289 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1292 case DNS_PROTOCOL_LLMNR
:
1293 case DNS_PROTOCOL_MDNS
:
1294 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1298 assert_not_reached("Invalid DNS protocol.");
1301 if (t
->initial_jitter_scheduled
)
1302 t
->initial_jitter_elapsed
= true;
1305 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1307 dns_transaction_retry(t
, true);
1311 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1315 switch (t
->scope
->protocol
) {
1317 case DNS_PROTOCOL_DNS
:
1319 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1320 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1323 return TRANSACTION_TCP_TIMEOUT_USEC
;
1325 return DNS_TIMEOUT_USEC
;
1327 case DNS_PROTOCOL_MDNS
:
1328 assert(t
->n_attempts
> 0);
1330 return MDNS_PROBING_INTERVAL_USEC
;
1332 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1334 case DNS_PROTOCOL_LLMNR
:
1335 return t
->scope
->resend_timeout
;
1338 assert_not_reached("Invalid DNS protocol.");
1342 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1347 dns_transaction_stop_timeout(t
);
1349 if (!dns_scope_network_good(t
->scope
)) {
1350 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1354 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1355 DnsTransactionState result
;
1357 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
)
1358 /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve
1360 result
= DNS_TRANSACTION_NOT_FOUND
;
1362 result
= DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
;
1364 dns_transaction_complete(t
, result
);
1368 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1369 /* If we already tried via a stream, then we don't
1370 * retry on LLMNR. See RFC 4795, Section 2.7. */
1371 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1378 dns_transaction_reset_answer(t
);
1379 dns_transaction_flush_dnssec_transactions(t
);
1381 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1382 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1383 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1387 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1388 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1389 t
->answer_authenticated
= true;
1390 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1394 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1395 t
->key
->type
== DNS_TYPE_DS
) {
1397 /* Hmm, this is a request for the root DS? A
1398 * DS RR doesn't exist in the root zone, and
1399 * if our trust anchor didn't know it either,
1400 * this means we cannot do any DNSSEC logic
1403 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1404 /* We are in downgrade mode. In this
1405 * case, synthesize an unsigned empty
1406 * response, so that the any lookup
1407 * depending on this one can continue
1408 * assuming there was no DS, and hence
1409 * the root zone was unsigned. */
1411 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1412 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1413 t
->answer_authenticated
= false;
1414 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1416 /* If we are not in downgrade mode,
1417 * then fail the lookup, because we
1418 * cannot reasonably answer it. There
1419 * might be DS RRs, but we don't know
1420 * them, and the DNS server won't tell
1421 * them to us (and even if it would,
1422 * we couldn't validate and trust them. */
1423 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1429 /* Check the zone, but only if this transaction is not used
1430 * for probing or verifying a zone item. */
1431 if (set_isempty(t
->notify_zone_items
)) {
1433 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1437 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1438 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1439 t
->answer_authenticated
= true;
1440 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1445 /* Check the cache, but only if this transaction is not used
1446 * for probing or verifying a zone item. */
1447 if (set_isempty(t
->notify_zone_items
)) {
1449 /* Before trying the cache, let's make sure we figured out a
1450 * server to use. Should this cause a change of server this
1451 * might flush the cache. */
1452 (void) dns_scope_get_dns_server(t
->scope
);
1454 /* Let's then prune all outdated entries */
1455 dns_cache_prune(&t
->scope
->cache
);
1457 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1461 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1462 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1463 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1465 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1473 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1475 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1476 bool add_known_answers
= false;
1477 DnsTransaction
*other
;
1479 DnsResourceKey
*tkey
;
1480 _cleanup_set_free_ Set
*keys
= NULL
;
1482 unsigned nscount
= 0;
1487 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1489 /* Discard any previously prepared packet, so we can start over and coalesce again */
1490 t
->sent
= dns_packet_unref(t
->sent
);
1492 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1496 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1502 if (dns_key_is_shared(t
->key
))
1503 add_known_answers
= true;
1505 if (t
->key
->type
== DNS_TYPE_ANY
) {
1506 r
= set_ensure_put(&keys
, &dns_resource_key_hash_ops
, t
->key
);
1512 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1513 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1514 * in our current scope, and see whether their timing constraints allow them to be sent.
1517 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1519 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1521 /* Skip ourselves */
1525 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1528 if (other
->next_attempt_after
> ts
)
1531 if (qdcount
>= UINT16_MAX
)
1534 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1537 * If we can't stuff more questions into the packet, just give up.
1538 * One of the 'other' transactions will fire later and take care of the rest.
1546 r
= dns_transaction_prepare(other
, ts
);
1550 ts
+= transaction_get_resend_timeout(other
);
1552 r
= sd_event_add_time(
1553 other
->scope
->manager
->event
,
1554 &other
->timeout_event_source
,
1555 clock_boottime_or_monotonic(),
1557 on_transaction_timeout
, other
);
1561 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1563 other
->state
= DNS_TRANSACTION_PENDING
;
1564 other
->next_attempt_after
= ts
;
1568 if (dns_key_is_shared(other
->key
))
1569 add_known_answers
= true;
1571 if (other
->key
->type
== DNS_TYPE_ANY
) {
1572 r
= set_ensure_put(&keys
, &dns_resource_key_hash_ops
, other
->key
);
1578 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1580 /* Append known answer section if we're asking for any shared record */
1581 if (add_known_answers
) {
1582 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1587 SET_FOREACH(tkey
, keys
, i
) {
1588 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1591 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1595 r
= dns_packet_append_answer(p
, answer
);
1599 nscount
+= dns_answer_size(answer
);
1601 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1603 t
->sent
= TAKE_PTR(p
);
1608 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1609 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1614 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1615 return dns_transaction_make_packet_mdns(t
);
1620 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1624 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1628 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1629 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1631 t
->sent
= TAKE_PTR(p
);
1636 int dns_transaction_go(DnsTransaction
*t
) {
1639 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1643 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1646 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1648 r
= dns_transaction_prepare(t
, ts
);
1652 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1654 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1655 dns_protocol_to_string(t
->scope
->protocol
),
1656 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
1657 af_to_name_short(t
->scope
->family
));
1659 if (!t
->initial_jitter_scheduled
&&
1660 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1661 usec_t jitter
, accuracy
;
1663 /* RFC 4795 Section 2.7 suggests all queries should be
1664 * delayed by a random time from 0 to JITTER_INTERVAL. */
1666 t
->initial_jitter_scheduled
= true;
1668 random_bytes(&jitter
, sizeof(jitter
));
1670 switch (t
->scope
->protocol
) {
1672 case DNS_PROTOCOL_LLMNR
:
1673 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1674 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1677 case DNS_PROTOCOL_MDNS
:
1678 jitter
%= MDNS_JITTER_RANGE_USEC
;
1679 jitter
+= MDNS_JITTER_MIN_USEC
;
1680 accuracy
= MDNS_JITTER_RANGE_USEC
;
1683 assert_not_reached("bad protocol");
1686 r
= sd_event_add_time(
1687 t
->scope
->manager
->event
,
1688 &t
->timeout_event_source
,
1689 clock_boottime_or_monotonic(),
1690 ts
+ jitter
, accuracy
,
1691 on_transaction_timeout
, t
);
1695 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1698 t
->next_attempt_after
= ts
;
1699 t
->state
= DNS_TRANSACTION_PENDING
;
1701 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1705 /* Otherwise, we need to ask the network */
1706 r
= dns_transaction_make_packet(t
);
1710 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1711 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1712 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1714 /* RFC 4795, Section 2.4. says reverse lookups shall
1715 * always be made via TCP on LLMNR */
1716 r
= dns_transaction_emit_tcp(t
);
1718 /* Try via UDP, and if that fails due to large size or lack of
1719 * support try via TCP */
1720 r
= dns_transaction_emit_udp(t
);
1722 log_debug("Sending query via TCP since it is too large.");
1723 else if (r
== -EAGAIN
)
1724 log_debug("Sending query via TCP since UDP isn't supported.");
1725 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1726 r
= dns_transaction_emit_tcp(t
);
1730 /* No servers to send this to? */
1731 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1734 if (r
== -EOPNOTSUPP
) {
1735 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1736 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1739 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1740 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1741 * answer this request with this protocol. */
1742 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1746 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1749 /* Couldn't send? Try immediately again, with a new server */
1750 dns_scope_next_dns_server(t
->scope
);
1752 return dns_transaction_go(t
);
1755 ts
+= transaction_get_resend_timeout(t
);
1757 r
= sd_event_add_time(
1758 t
->scope
->manager
->event
,
1759 &t
->timeout_event_source
,
1760 clock_boottime_or_monotonic(),
1762 on_transaction_timeout
, t
);
1766 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1768 t
->state
= DNS_TRANSACTION_PENDING
;
1769 t
->next_attempt_after
= ts
;
1774 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1782 /* Try to find cyclic dependencies between transaction objects */
1787 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1788 r
= dns_transaction_find_cyclic(t
, n
);
1796 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1797 _cleanup_(dns_transaction_gcp
) DnsTransaction
*aux
= NULL
;
1804 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1806 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1810 if (set_contains(t
->dnssec_transactions
, aux
)) {
1815 r
= dns_transaction_find_cyclic(t
, aux
);
1819 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1821 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1822 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1824 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1826 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1830 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1834 r
= set_ensure_put(&t
->dnssec_transactions
, NULL
, aux
);
1838 r
= set_ensure_put(&aux
->notify_transactions
, NULL
, t
);
1840 (void) set_remove(t
->dnssec_transactions
, aux
);
1844 *ret
= TAKE_PTR(aux
);
1848 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1849 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1850 DnsTransaction
*aux
;
1856 /* Try to get the data from the trust anchor */
1857 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1861 r
= dns_answer_extend(&t
->validated_keys
, a
);
1868 /* This didn't work, ask for it via the network/cache then. */
1869 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1870 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1875 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1876 r
= dns_transaction_go(aux
);
1884 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1889 /* Check whether the specified name is in the NTA
1890 * database, either in the global one, or the link-local
1893 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1897 if (!t
->scope
->link
)
1900 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1903 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1908 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1909 * RRs to prove it */
1911 r
= dns_transaction_has_positive_answer(t
, NULL
);
1917 /* Is this key explicitly listed as a negative trust anchor?
1918 * If so, it's nothing we need to care about */
1919 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1925 /* The answer does not contain any RRs that match to the
1926 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1927 * included. If not, the answer is unsigned. */
1929 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1938 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1944 /* Check if the specified RR is the "primary" response,
1945 * i.e. either matches the question precisely or is a
1946 * CNAME/DNAME for it. */
1948 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1952 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1955 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1958 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1959 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1961 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1964 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1965 * be supported, hence return true. */
1969 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1970 * the server is known to support currently, as the transaction feature level might be lower than what the
1971 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1972 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1974 return dns_server_dnssec_supported(t
->server
);
1977 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1983 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1985 if (!dns_transaction_dnssec_supported(t
))
1988 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1989 if (!dns_transaction_dnssec_supported(dt
))
1995 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
1996 DnsResourceRecord
*rr
;
2003 * Retrieve all auxiliary RRs for the answer we got, so that
2004 * we can verify signatures or prove that RRs are rightfully
2005 * unsigned. Specifically:
2007 * - For RRSIG we get the matching DNSKEY
2008 * - For DNSKEY we get the matching DS
2009 * - For unsigned SOA/NS we get the matching DS
2010 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2011 * - For other unsigned RRs we get the matching SOA RR
2012 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2013 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2014 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2017 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2019 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2020 return 0; /* We only need to validate stuff from the network */
2021 if (!dns_transaction_dnssec_supported(t
))
2022 return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */
2024 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2026 if (dns_type_is_pseudo(rr
->key
->type
))
2029 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2030 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2036 switch (rr
->key
->type
) {
2038 case DNS_TYPE_RRSIG
: {
2039 /* For each RRSIG we request the matching DNSKEY */
2040 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2042 /* If this RRSIG is about a DNSKEY RR and the
2043 * signer is the same as the owner, then we
2044 * already have the DNSKEY, and we don't have
2045 * to look for more. */
2046 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2047 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2054 /* If the signer is not a parent of our
2055 * original query, then this is about an
2056 * auxiliary RRset, but not anything we asked
2057 * for. In this case we aren't interested,
2058 * because we don't want to request additional
2059 * RRs for stuff we didn't really ask for, and
2060 * also to avoid request loops, where
2061 * additional RRs from one transaction result
2062 * in another transaction whose additional RRs
2063 * point back to the original transaction, and
2065 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2071 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2075 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2076 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2077 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2083 case DNS_TYPE_DNSKEY
: {
2084 /* For each DNSKEY we request the matching DS */
2085 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2087 /* If the DNSKEY we are looking at is not for
2088 * zone we are interested in, nor any of its
2089 * parents, we aren't interested, and don't
2090 * request it. After all, we don't want to end
2091 * up in request loops, and want to keep
2092 * additional traffic down. */
2094 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2100 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2104 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2105 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2106 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2115 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2117 /* For an unsigned SOA or NS, try to acquire
2118 * the matching DS RR, as we are at a zone cut
2119 * then, and whether a DS exists tells us
2120 * whether the zone is signed. Do so only if
2121 * this RR matches our original question,
2124 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2128 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2129 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2130 * If so, we need to validate it, too. */
2132 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2135 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2139 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2140 * what we are looking for, otherwise there's no value in it for us. */
2141 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2148 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2154 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2158 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2159 t
->id
, dns_resource_key_name(rr
->key
));
2160 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2168 case DNS_TYPE_CNAME
:
2169 case DNS_TYPE_DNAME
: {
2170 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2173 /* CNAMEs and DNAMEs cannot be located at a
2174 * zone apex, hence ask for the parent SOA for
2175 * unsigned CNAME/DNAME RRs, maybe that's the
2176 * apex. But do all that only if this is
2177 * actually a response to our original
2180 * Similar for DS RRs, which are signed when
2181 * the parent SOA is signed. */
2183 r
= dns_transaction_is_primary_response(t
, rr
);
2189 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2195 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2201 name
= dns_resource_key_name(rr
->key
);
2202 r
= dns_name_parent(&name
);
2208 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2212 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2213 t
->id
, dns_resource_key_name(rr
->key
));
2214 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2222 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2224 /* For other unsigned RRsets (including
2225 * NSEC/NSEC3!), look for proof the zone is
2226 * unsigned, by requesting the SOA RR of the
2227 * zone. However, do so only if they are
2228 * directly relevant to our original
2231 r
= dns_transaction_is_primary_response(t
, rr
);
2237 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2243 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2247 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2248 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2249 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2256 /* Above, we requested everything necessary to validate what
2257 * we got. Now, let's request what we need to validate what we
2260 r
= dns_transaction_has_unsigned_negative_answer(t
);
2267 name
= dns_resource_key_name(t
->key
);
2269 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2270 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2271 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2272 * though they have further children. If this was a DS request, then it's signed when the parent zone
2273 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2274 * to see if that is signed. */
2276 if (t
->key
->type
== DNS_TYPE_DS
) {
2277 r
= dns_name_parent(&name
);
2279 type
= DNS_TYPE_SOA
;
2280 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2281 name
, t
->id
, dns_resource_key_name(t
->key
));
2285 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2288 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2292 type
= DNS_TYPE_SOA
;
2293 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2298 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2300 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2304 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2310 return dns_transaction_dnssec_is_live(t
);
2313 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2317 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2318 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2319 the state is VALIDATING however, we should check if we are complete now. */
2321 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2322 dns_transaction_process_dnssec(t
);
2325 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2326 DnsResourceRecord
*rr
;
2331 /* Add all DNSKEY RRs from the answer that are validated by DS
2332 * RRs from the list of validated keys to the list of
2333 * validated keys. */
2335 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2337 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2343 /* If so, the DNSKEY is validated too. */
2344 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2352 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2358 /* Checks if the RR we are looking for must be signed with an
2359 * RRSIG. This is used for positive responses. */
2361 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2364 if (dns_type_is_pseudo(rr
->key
->type
))
2367 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2373 switch (rr
->key
->type
) {
2375 case DNS_TYPE_RRSIG
:
2376 /* RRSIGs are the signatures themselves, they need no signing. */
2384 /* For SOA or NS RRs we look for a matching DS transaction */
2386 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2388 if (dt
->key
->class != rr
->key
->class)
2390 if (dt
->key
->type
!= DNS_TYPE_DS
)
2393 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2399 /* We found a DS transactions for the SOA/NS
2400 * RRs we are looking at. If it discovered signed DS
2401 * RRs, then we need to be signed, too. */
2403 if (!dt
->answer_authenticated
)
2406 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2409 /* We found nothing that proves this is safe to leave
2410 * this unauthenticated, hence ask inist on
2411 * authentication. */
2416 case DNS_TYPE_CNAME
:
2417 case DNS_TYPE_DNAME
: {
2418 const char *parent
= NULL
;
2423 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2425 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2428 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2430 if (dt
->key
->class != rr
->key
->class)
2432 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2436 parent
= dns_resource_key_name(rr
->key
);
2437 r
= dns_name_parent(&parent
);
2441 if (rr
->key
->type
== DNS_TYPE_DS
)
2444 /* A CNAME/DNAME without a parent? That's sooo weird. */
2445 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2446 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2450 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2456 return t
->answer_authenticated
;
2466 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2468 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2470 if (dt
->key
->class != rr
->key
->class)
2472 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2475 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2481 /* We found the transaction that was supposed to find
2482 * the SOA RR for us. It was successful, but found no
2483 * RR for us. This means we are not at a zone cut. In
2484 * this case, we require authentication if the SOA
2485 * lookup was authenticated too. */
2486 return t
->answer_authenticated
;
2493 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2499 /* If DNSSEC downgrade mode is on, checks whether the
2500 * specified RR is one level below a TLD we have proven not to
2501 * exist. In such a case we assume that this is a private
2502 * domain, and permit it.
2504 * This detects cases like the Fritz!Box router networks. Each
2505 * Fritz!Box router serves a private "fritz.box" zone, in the
2506 * non-existing TLD "box". Requests for the "fritz.box" domain
2507 * are served by the router itself, while requests for the
2508 * "box" domain will result in NXDOMAIN.
2510 * Note that this logic is unable to detect cases where a
2511 * router serves a private DNS zone directly under
2512 * non-existing TLD. In such a case we cannot detect whether
2513 * the TLD is supposed to exist or not, as all requests we
2514 * make for it will be answered by the router's zone, and not
2515 * by the root zone. */
2519 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2520 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2522 tld
= dns_resource_key_name(key
);
2523 r
= dns_name_parent(&tld
);
2527 return false; /* Already the root domain */
2529 if (!dns_name_is_single_label(tld
))
2532 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2534 if (dt
->key
->class != key
->class)
2537 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2543 /* We found an auxiliary lookup we did for the TLD. If
2544 * that returned with NXDOMAIN, we know the TLD didn't
2545 * exist, and hence this might be a private zone. */
2547 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2553 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2554 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2563 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2564 * this negative reply */
2566 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2569 if (dns_type_is_pseudo(t
->key
->type
))
2572 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2578 r
= dns_transaction_in_private_tld(t
, t
->key
);
2582 /* The lookup is from a TLD that is proven not to
2583 * exist, and we are in downgrade mode, hence ignore
2584 * that fact that we didn't get any NSEC RRs. */
2586 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2587 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2591 name
= dns_resource_key_name(t
->key
);
2593 if (t
->key
->type
== DNS_TYPE_DS
) {
2595 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2596 * hence check the parent SOA in this case. */
2598 r
= dns_name_parent(&name
);
2604 type
= DNS_TYPE_SOA
;
2606 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2607 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2610 /* For all other negative replies, check for the SOA lookup */
2611 type
= DNS_TYPE_SOA
;
2613 /* For all other RRs we check the SOA on the same level to see
2614 * if it's signed. */
2616 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2618 if (dt
->key
->class != t
->key
->class)
2620 if (dt
->key
->type
!= type
)
2623 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2629 return dt
->answer_authenticated
;
2632 /* If in doubt, require NSEC/NSEC3 */
2636 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2637 DnsResourceRecord
*rrsig
;
2641 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2642 * the specified RRset is authenticated (i.e. has a matching
2645 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2651 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2655 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2661 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2663 if (dt
->key
->class != rr
->key
->class)
2666 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2668 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2674 /* OK, we found an auxiliary DNSKEY
2675 * lookup. If that lookup is
2676 * authenticated, report this. */
2678 if (dt
->answer_authenticated
)
2683 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2685 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2691 /* OK, we found an auxiliary DS
2692 * lookup. If that lookup is
2693 * authenticated and non-zero, we
2696 if (!dt
->answer_authenticated
)
2699 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2704 return found
? false : -ENXIO
;
2707 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2711 /* We know that the root domain is signed, hence if it appears
2712 * not to be signed, there's a problem with the DNS server */
2714 return rr
->key
->class == DNS_CLASS_IN
&&
2715 dns_name_is_root(dns_resource_key_name(rr
->key
));
2718 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2719 DnsResourceRecord
*rr
;
2724 /* Maybe warn the user that we encountered a revoked DNSKEY
2725 * for a key from our trust anchor. Note that we don't care
2726 * whether the DNSKEY can be authenticated or not. It's
2727 * sufficient if it is self-signed. */
2729 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2730 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2738 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2744 /* Removes all DNSKEY/DS objects from t->validated_keys that
2745 * our trust anchors database considers revoked. */
2748 DnsResourceRecord
*rr
;
2752 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2753 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2757 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2771 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2778 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2780 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2782 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2785 if (!dt
->answer_authenticated
)
2788 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2797 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2798 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2799 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2802 static int dnssec_validate_records(
2806 DnsAnswer
**validated
) {
2808 DnsResourceRecord
*rr
;
2811 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2813 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2814 DnsResourceRecord
*rrsig
= NULL
;
2815 DnssecResult result
;
2817 switch (rr
->key
->type
) {
2818 case DNS_TYPE_RRSIG
:
2821 case DNS_TYPE_DNSKEY
:
2822 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2823 if (phase
== DNSSEC_PHASE_NSEC
)
2828 case DNS_TYPE_NSEC3
:
2831 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2832 if (phase
== DNSSEC_PHASE_DNSKEY
)
2837 /* We validate all other RRs only in the ALL phases */
2838 if (phase
!= DNSSEC_PHASE_ALL
)
2842 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2846 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2848 if (result
== DNSSEC_VALIDATED
) {
2850 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2851 /* If we just validated a DNSKEY RRset, then let's add these keys to
2852 * the set of validated keys for this transaction. */
2854 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2858 /* Some of the DNSKEYs we just added might already have been revoked,
2859 * remove them again in that case. */
2860 r
= dns_transaction_invalidate_revoked_keys(t
);
2865 /* Add the validated RRset to the new list of validated
2866 * RRsets, and remove it from the unvalidated RRsets.
2867 * We mark the RRset as authenticated and cacheable. */
2868 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2872 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2874 /* Exit the loop, we dropped something from the answer, start from the beginning */
2878 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2879 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2880 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2881 if (phase
!= DNSSEC_PHASE_ALL
)
2884 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2885 bool authenticated
= false;
2888 /* This RRset validated, but as a wildcard. This means we need
2889 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2891 /* First step, determine the source of synthesis */
2892 r
= dns_resource_record_source(rrsig
, &source
);
2896 r
= dnssec_test_positive_wildcard(*validated
,
2897 dns_resource_key_name(rr
->key
),
2899 rrsig
->rrsig
.signer
,
2902 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2904 result
= DNSSEC_INVALID
;
2906 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2907 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2911 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2913 /* Exit the loop, we dropped something from the answer, start from the beginning */
2918 if (result
== DNSSEC_NO_SIGNATURE
) {
2919 r
= dns_transaction_requires_rrsig(t
, rr
);
2923 /* Data does not require signing. In that case, just copy it over,
2924 * but remember that this is by no means authenticated. */
2925 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2929 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2933 r
= dns_transaction_known_signed(t
, rr
);
2937 /* This is an RR we know has to be signed. If it isn't this means
2938 * the server is not attaching RRSIGs, hence complain. */
2940 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2942 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2944 /* Downgrading is OK? If so, just consider the information unsigned */
2946 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2950 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2954 /* Otherwise, fail */
2955 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2959 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2963 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2965 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2966 * mode, hence ignore the fact that this was not signed. */
2968 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2969 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2971 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2975 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2982 DNSSEC_SIGNATURE_EXPIRED
,
2983 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2985 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2986 if (r
< 0 && r
!= -ENXIO
)
2989 /* The DNSKEY transaction was not authenticated, this means there's
2990 * no DS for this, which means it's OK if no keys are found for this signature. */
2992 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2996 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
3001 r
= dns_transaction_is_primary_response(t
, rr
);
3005 /* Look for a matching DNAME for this CNAME */
3006 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
3010 /* Also look among the stuff we already validated */
3011 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3019 DNSSEC_SIGNATURE_EXPIRED
,
3020 DNSSEC_NO_SIGNATURE
))
3021 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3022 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3023 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3025 /* This is a primary response to our question, and it failed validation.
3027 t
->answer_dnssec_result
= result
;
3031 /* This is a primary response, but we do have a DNAME RR
3032 * in the RR that can replay this CNAME, hence rely on
3033 * that, and we can remove the CNAME in favour of it. */
3036 /* This is just some auxiliary data. Just remove the RRset and continue. */
3037 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3041 /* We dropped something from the answer, start from the beginning. */
3045 return 2; /* Finito. */
3048 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3049 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3051 DnsAnswerFlags flags
;
3053 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3057 /* We have now collected all DS and DNSKEY RRs in
3058 * t->validated_keys, let's see which RRs we can now
3059 * authenticate with that. */
3061 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3064 /* Already validated */
3065 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3068 /* Our own stuff needs no validation */
3069 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3070 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3071 t
->answer_authenticated
= true;
3075 /* Cached stuff is not affected by validation. */
3076 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3079 if (!dns_transaction_dnssec_supported_full(t
)) {
3080 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3081 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3082 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3086 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3088 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3090 /* First, see if this response contains any revoked trust
3091 * anchors we care about */
3092 r
= dns_transaction_check_revoked_trust_anchors(t
);
3096 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3097 r
= dns_transaction_copy_validated(t
);
3101 /* Second, see if there are DNSKEYs we already know a
3102 * validated DS for. */
3103 r
= dns_transaction_validate_dnskey_by_ds(t
);
3107 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3108 * anchor says are revoked. After all we might have marked
3109 * some keys revoked above, but they might still be lingering
3110 * in our validated_keys list. */
3111 r
= dns_transaction_invalidate_revoked_keys(t
);
3115 phase
= DNSSEC_PHASE_DNSKEY
;
3117 bool have_nsec
= false;
3119 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3123 /* Try again as long as we managed to achieve something */
3127 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3128 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3129 phase
= DNSSEC_PHASE_NSEC
;
3133 if (phase
!= DNSSEC_PHASE_ALL
) {
3134 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3135 * Note that in this third phase we start to remove RRs we couldn't validate. */
3136 phase
= DNSSEC_PHASE_ALL
;
3144 dns_answer_unref(t
->answer
);
3145 t
->answer
= TAKE_PTR(validated
);
3147 /* At this point the answer only contains validated
3148 * RRsets. Now, let's see if it actually answers the question
3149 * we asked. If so, great! If it doesn't, then see if
3150 * NSEC/NSEC3 can prove this. */
3151 r
= dns_transaction_has_positive_answer(t
, &flags
);
3153 /* Yes, it answers the question! */
3155 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3156 /* The answer is fully authenticated, yay. */
3157 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3158 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3159 t
->answer_authenticated
= true;
3161 /* The answer is not fully authenticated. */
3162 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3163 t
->answer_authenticated
= false;
3166 } else if (r
== 0) {
3167 DnssecNsecResult nr
;
3168 bool authenticated
= false;
3170 /* Bummer! Let's check NSEC/NSEC3 */
3171 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3177 case DNSSEC_NSEC_NXDOMAIN
:
3178 /* NSEC proves the domain doesn't exist. Very good. */
3179 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3180 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3181 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3182 t
->answer_authenticated
= authenticated
;
3184 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3187 case DNSSEC_NSEC_NODATA
:
3188 /* NSEC proves that there's no data here, very good. */
3189 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3190 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3191 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3192 t
->answer_authenticated
= authenticated
;
3194 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3197 case DNSSEC_NSEC_OPTOUT
:
3198 /* NSEC3 says the data might not be signed */
3199 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3200 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3201 t
->answer_authenticated
= false;
3203 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3206 case DNSSEC_NSEC_NO_RR
:
3207 /* No NSEC data? Bummer! */
3209 r
= dns_transaction_requires_nsec(t
);
3213 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3214 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3216 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3217 t
->answer_authenticated
= false;
3218 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3223 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3224 /* We don't know the NSEC3 algorithm used? */
3225 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3226 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3229 case DNSSEC_NSEC_FOUND
:
3230 case DNSSEC_NSEC_CNAME
:
3231 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3232 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3233 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3237 assert_not_reached("Unexpected NSEC result.");
3244 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3245 [DNS_TRANSACTION_NULL
] = "null",
3246 [DNS_TRANSACTION_PENDING
] = "pending",
3247 [DNS_TRANSACTION_VALIDATING
] = "validating",
3248 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3249 [DNS_TRANSACTION_SUCCESS
] = "success",
3250 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3251 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3252 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3253 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3254 [DNS_TRANSACTION_ERRNO
] = "errno",
3255 [DNS_TRANSACTION_ABORTED
] = "aborted",
3256 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3257 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3258 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3259 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3260 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3262 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3264 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3265 [DNS_TRANSACTION_NETWORK
] = "network",
3266 [DNS_TRANSACTION_CACHE
] = "cache",
3267 [DNS_TRANSACTION_ZONE
] = "zone",
3268 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3270 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);