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-llmnr.h"
15 #if ENABLE_DNS_OVER_TLS
16 #include "resolved-dnstls.h"
18 #include "string-table.h"
20 #define TRANSACTIONS_MAX 4096
21 #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
23 /* After how much time to repeat classic DNS requests */
24 #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX)
26 static void dns_transaction_reset_answer(DnsTransaction
*t
) {
29 t
->received
= dns_packet_unref(t
->received
);
30 t
->answer
= dns_answer_unref(t
->answer
);
32 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
33 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
34 t
->answer_authenticated
= false;
35 t
->answer_nsec_ttl
= (uint32_t) -1;
39 static void dns_transaction_flush_dnssec_transactions(DnsTransaction
*t
) {
44 while ((z
= set_steal_first(t
->dnssec_transactions
))) {
45 set_remove(z
->notify_transactions
, t
);
46 set_remove(z
->notify_transactions_done
, t
);
47 dns_transaction_gc(z
);
51 static void dns_transaction_close_connection(DnsTransaction
*t
) {
55 /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
56 LIST_REMOVE(transactions_by_stream
, t
->stream
->transactions
, t
);
58 /* Remove packet in case it's still in the queue */
59 dns_packet_unref(ordered_set_remove(t
->stream
->write_queue
, t
->sent
));
61 t
->stream
= dns_stream_unref(t
->stream
);
64 t
->dns_udp_event_source
= sd_event_source_unref(t
->dns_udp_event_source
);
65 t
->dns_udp_fd
= safe_close(t
->dns_udp_fd
);
68 static void dns_transaction_stop_timeout(DnsTransaction
*t
) {
71 t
->timeout_event_source
= sd_event_source_unref(t
->timeout_event_source
);
74 DnsTransaction
* dns_transaction_free(DnsTransaction
*t
) {
82 log_debug("Freeing transaction %" PRIu16
".", t
->id
);
84 dns_transaction_close_connection(t
);
85 dns_transaction_stop_timeout(t
);
87 dns_packet_unref(t
->sent
);
88 dns_transaction_reset_answer(t
);
90 dns_server_unref(t
->server
);
93 hashmap_remove_value(t
->scope
->transactions_by_key
, t
->key
, t
);
94 LIST_REMOVE(transactions_by_scope
, t
->scope
->transactions
, t
);
97 hashmap_remove(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
100 while ((c
= set_steal_first(t
->notify_query_candidates
)))
101 set_remove(c
->transactions
, t
);
102 set_free(t
->notify_query_candidates
);
104 while ((c
= set_steal_first(t
->notify_query_candidates_done
)))
105 set_remove(c
->transactions
, t
);
106 set_free(t
->notify_query_candidates_done
);
108 while ((i
= set_steal_first(t
->notify_zone_items
)))
109 i
->probe_transaction
= NULL
;
110 set_free(t
->notify_zone_items
);
112 while ((i
= set_steal_first(t
->notify_zone_items_done
)))
113 i
->probe_transaction
= NULL
;
114 set_free(t
->notify_zone_items_done
);
116 while ((z
= set_steal_first(t
->notify_transactions
)))
117 set_remove(z
->dnssec_transactions
, t
);
118 set_free(t
->notify_transactions
);
120 while ((z
= set_steal_first(t
->notify_transactions_done
)))
121 set_remove(z
->dnssec_transactions
, t
);
122 set_free(t
->notify_transactions_done
);
124 dns_transaction_flush_dnssec_transactions(t
);
125 set_free(t
->dnssec_transactions
);
127 dns_answer_unref(t
->validated_keys
);
128 dns_resource_key_unref(t
->key
);
133 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction
*, dns_transaction_free
);
135 bool dns_transaction_gc(DnsTransaction
*t
) {
141 if (set_isempty(t
->notify_query_candidates
) &&
142 set_isempty(t
->notify_query_candidates_done
) &&
143 set_isempty(t
->notify_zone_items
) &&
144 set_isempty(t
->notify_zone_items_done
) &&
145 set_isempty(t
->notify_transactions
) &&
146 set_isempty(t
->notify_transactions_done
)) {
147 dns_transaction_free(t
);
154 static uint16_t pick_new_id(Manager
*m
) {
157 /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of
158 * transactions, and it's much lower than the space of IDs. */
160 assert_cc(TRANSACTIONS_MAX
< 0xFFFF);
163 random_bytes(&new_id
, sizeof(new_id
));
164 while (new_id
== 0 ||
165 hashmap_get(m
->dns_transactions
, UINT_TO_PTR(new_id
)));
170 int dns_transaction_new(DnsTransaction
**ret
, DnsScope
*s
, DnsResourceKey
*key
) {
171 _cleanup_(dns_transaction_freep
) DnsTransaction
*t
= NULL
;
178 /* Don't allow looking up invalid or pseudo RRs */
179 if (!dns_type_is_valid_query(key
->type
))
181 if (dns_type_is_obsolete(key
->type
))
184 /* We only support the IN class */
185 if (!IN_SET(key
->class, DNS_CLASS_IN
, DNS_CLASS_ANY
))
188 if (hashmap_size(s
->manager
->dns_transactions
) >= TRANSACTIONS_MAX
)
191 r
= hashmap_ensure_allocated(&s
->manager
->dns_transactions
, NULL
);
195 r
= hashmap_ensure_allocated(&s
->transactions_by_key
, &dns_resource_key_hash_ops
);
199 t
= new0(DnsTransaction
, 1);
204 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
205 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
206 t
->answer_nsec_ttl
= (uint32_t) -1;
207 t
->key
= dns_resource_key_ref(key
);
208 t
->current_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
209 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
211 t
->id
= pick_new_id(s
->manager
);
213 r
= hashmap_put(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), t
);
219 r
= hashmap_replace(s
->transactions_by_key
, t
->key
, t
);
221 hashmap_remove(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
225 LIST_PREPEND(transactions_by_scope
, s
->transactions
, t
);
228 s
->manager
->n_transactions_total
++;
238 static void dns_transaction_shuffle_id(DnsTransaction
*t
) {
242 /* Pick a new ID for this transaction. */
244 new_id
= pick_new_id(t
->scope
->manager
);
245 assert_se(hashmap_remove_and_put(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), UINT_TO_PTR(new_id
), t
) >= 0);
247 log_debug("Transaction %" PRIu16
" is now %" PRIu16
".", t
->id
, new_id
);
250 /* Make sure we generate a new packet with the new ID */
251 t
->sent
= dns_packet_unref(t
->sent
);
254 static void dns_transaction_tentative(DnsTransaction
*t
, DnsPacket
*p
) {
255 _cleanup_free_
char *pretty
= NULL
;
256 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
262 if (manager_our_packet(t
->scope
->manager
, p
) != 0)
265 (void) in_addr_to_string(p
->family
, &p
->sender
, &pretty
);
267 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s got tentative packet from %s.",
269 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
270 dns_protocol_to_string(t
->scope
->protocol
),
271 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
272 af_to_name_short(t
->scope
->family
),
275 /* RFC 4795, Section 4.1 says that the peer with the
276 * lexicographically smaller IP address loses */
277 if (memcmp(&p
->sender
, &p
->destination
, FAMILY_ADDRESS_SIZE(p
->family
)) >= 0) {
278 log_debug("Peer has lexicographically larger IP address and thus lost in the conflict.");
282 log_debug("We have the lexicographically larger IP address and thus lost in the conflict.");
286 while ((z
= set_first(t
->notify_zone_items
))) {
287 /* First, make sure the zone item drops the reference
289 dns_zone_item_probe_stop(z
);
291 /* Secondly, report this as conflict, so that we might
292 * look for a different hostname */
293 dns_zone_item_conflict(z
);
297 dns_transaction_gc(t
);
300 void dns_transaction_complete(DnsTransaction
*t
, DnsTransactionState state
) {
301 DnsQueryCandidate
*c
;
305 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
308 assert(!DNS_TRANSACTION_IS_LIVE(state
));
310 if (state
== DNS_TRANSACTION_DNSSEC_FAILED
) {
311 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
);
313 log_struct(LOG_NOTICE
,
314 "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR
,
315 LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str
, dnssec_result_to_string(t
->answer_dnssec_result
)),
316 "DNS_TRANSACTION=%" PRIu16
, t
->id
,
317 "DNS_QUESTION=%s", key_str
,
318 "DNSSEC_RESULT=%s", dnssec_result_to_string(t
->answer_dnssec_result
),
319 "DNS_SERVER=%s", dns_server_string(t
->server
),
320 "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t
->server
->possible_feature_level
));
323 /* Note that this call might invalidate the query. Callers
324 * should hence not attempt to access the query or transaction
325 * after calling this function. */
327 if (state
== DNS_TRANSACTION_ERRNO
)
328 st
= errno_to_name(t
->answer_errno
);
330 st
= dns_transaction_state_to_string(state
);
332 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).",
334 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
335 dns_protocol_to_string(t
->scope
->protocol
),
336 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
337 af_to_name_short(t
->scope
->family
),
339 t
->answer_source
< 0 ? "none" : dns_transaction_source_to_string(t
->answer_source
),
340 t
->answer_authenticated
? "authenticated" : "unsigned");
344 dns_transaction_close_connection(t
);
345 dns_transaction_stop_timeout(t
);
347 /* Notify all queries that are interested, but make sure the
348 * transaction isn't freed while we are still looking at it */
351 SET_FOREACH_MOVE(c
, t
->notify_query_candidates_done
, t
->notify_query_candidates
)
352 dns_query_candidate_notify(c
);
353 SWAP_TWO(t
->notify_query_candidates
, t
->notify_query_candidates_done
);
355 SET_FOREACH_MOVE(z
, t
->notify_zone_items_done
, t
->notify_zone_items
)
356 dns_zone_item_notify(z
);
357 SWAP_TWO(t
->notify_zone_items
, t
->notify_zone_items_done
);
358 if (t
->probing
&& t
->state
== DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
)
359 (void) dns_scope_announce(t
->scope
, false);
361 SET_FOREACH_MOVE(d
, t
->notify_transactions_done
, t
->notify_transactions
)
362 dns_transaction_notify(d
, t
);
363 SWAP_TWO(t
->notify_transactions
, t
->notify_transactions_done
);
366 dns_transaction_gc(t
);
369 static int dns_transaction_pick_server(DnsTransaction
*t
) {
373 assert(t
->scope
->protocol
== DNS_PROTOCOL_DNS
);
375 /* Pick a DNS server and a feature level for it. */
377 server
= dns_scope_get_dns_server(t
->scope
);
381 /* If we changed the server invalidate the feature level clamping, as the new server might have completely
382 * different properties. */
383 if (server
!= t
->server
)
384 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
386 t
->current_feature_level
= dns_server_possible_feature_level(server
);
388 /* Clamp the feature level if that is requested. */
389 if (t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
&&
390 t
->current_feature_level
> t
->clamp_feature_level
)
391 t
->current_feature_level
= t
->clamp_feature_level
;
393 log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t
->current_feature_level
), t
->id
);
395 if (server
== t
->server
)
398 dns_server_unref(t
->server
);
399 t
->server
= dns_server_ref(server
);
401 t
->n_picked_servers
++;
403 log_debug("Using DNS server %s for transaction %u.", dns_server_string(t
->server
), t
->id
);
408 static void dns_transaction_retry(DnsTransaction
*t
, bool next_server
) {
413 log_debug("Retrying transaction %" PRIu16
".", t
->id
);
415 /* Before we try again, switch to a new server. */
417 dns_scope_next_dns_server(t
->scope
);
419 r
= dns_transaction_go(t
);
421 t
->answer_errno
= -r
;
422 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
426 static int dns_transaction_maybe_restart(DnsTransaction
*t
) {
431 /* Returns > 0 if the transaction was restarted, 0 if not */
436 if (t
->current_feature_level
<= dns_server_possible_feature_level(t
->server
))
439 /* The server's current feature level is lower than when we sent the original query. We learnt something from
440 the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to
441 restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include
442 OPT RR or DO bit. One of these cases is documented here, for example:
443 https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */
445 log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID.");
446 dns_transaction_shuffle_id(t
);
448 r
= dns_transaction_go(t
);
455 static void on_transaction_stream_error(DnsTransaction
*t
, int error
) {
458 dns_transaction_close_connection(t
);
460 if (ERRNO_IS_DISCONNECT(error
)) {
461 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
) {
462 /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
463 * question on this scope. */
464 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
468 dns_transaction_retry(t
, true);
472 t
->answer_errno
= error
;
473 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
477 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
481 dns_transaction_close_connection(t
);
483 if (dns_packet_validate_reply(p
) <= 0) {
484 log_debug("Invalid TCP reply packet.");
485 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
489 dns_scope_check_conflicts(t
->scope
, p
);
492 dns_transaction_process_reply(t
, p
);
495 /* If the response wasn't useful, then complete the transition
496 * now. After all, we are the worst feature set now with TCP
497 * sockets, and there's really no point in retrying. */
498 if (t
->state
== DNS_TRANSACTION_PENDING
)
499 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
501 dns_transaction_gc(t
);
506 static int on_stream_complete(DnsStream
*s
, int error
) {
509 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
510 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
512 if (s
->transactions
) {
516 dns_server_packet_lost(t
->server
, IPPROTO_TCP
, t
->current_feature_level
);
521 DnsTransaction
*t
, *n
;
523 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
524 on_transaction_stream_error(t
, error
);
530 static int on_stream_packet(DnsStream
*s
) {
531 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
536 /* Take ownership of packet to be able to receive new packets */
537 p
= dns_stream_take_read_packet(s
);
540 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
542 return dns_transaction_on_stream_packet(t
, p
);
544 /* Ignore incorrect transaction id as an old transaction can have been canceled. */
545 log_debug("Received unexpected TCP reply packet with id %" PRIu16
", ignoring.", DNS_PACKET_ID(p
));
549 static uint16_t dns_port_for_feature_level(DnsServerFeatureLevel level
) {
550 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(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_port_for_feature_level(t
->current_feature_level
), &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
)
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
,
691 t
->answer_authenticated
,
695 &t
->received
->sender
);
698 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
704 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
705 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
711 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
717 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
718 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
720 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
724 case DNS_TRANSACTION_NULL
:
725 case DNS_TRANSACTION_PENDING
:
726 case DNS_TRANSACTION_VALIDATING
:
730 case DNS_TRANSACTION_RCODE_FAILURE
:
731 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
732 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
736 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
737 * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
738 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
739 * RRs to make unsigned proofs. */
741 case DNS_TRANSACTION_SUCCESS
:
745 case DNS_TRANSACTION_DNSSEC_FAILED
:
746 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
747 * validationr result */
749 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
750 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
751 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
755 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
760 /* All is ready, we can go and validate */
764 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
765 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
769 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
774 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
775 r
= dns_transaction_dnssec_ready(t
);
778 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
781 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
782 * restart the lookup immediately. */
783 r
= dns_transaction_maybe_restart(t
);
786 if (r
> 0) /* Transaction got restarted... */
789 /* All our auxiliary DNSSEC transactions are complete now. Try
790 * to validate our RRset now. */
791 r
= dns_transaction_validate_dnssec(t
);
793 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
799 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
800 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
802 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
805 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
806 /* We tried fewer servers on this transaction than we know, let's try another one then */
807 dns_transaction_retry(t
, true);
811 /* OK, let's give up, apparently all servers we tried didn't work. */
812 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
816 if (!IN_SET(t
->answer_dnssec_result
,
817 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
818 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
819 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
820 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
821 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
825 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
826 dns_server_warn_downgrade(t
->server
);
828 dns_transaction_cache_answer(t
);
830 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
831 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
833 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
838 t
->answer_errno
= -r
;
839 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
842 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
847 /* Checks whether the answer is positive, i.e. either a direct
848 * answer to the question, or a CNAME/DNAME for it */
850 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
854 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
861 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
866 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
867 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
868 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
869 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
870 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
871 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
872 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
873 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
874 * incomplete CNAME/DNAME chain.
876 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
877 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
880 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
883 r
= dns_transaction_has_positive_answer(t
, NULL
);
887 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
891 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
898 assert(t
->scope
->manager
);
900 if (t
->state
!= DNS_TRANSACTION_PENDING
)
903 /* Note that this call might invalidate the query. Callers
904 * should hence not attempt to access the query or transaction
905 * after calling this function. */
907 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
908 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
910 switch (t
->scope
->protocol
) {
912 case DNS_PROTOCOL_LLMNR
:
913 /* For LLMNR we will not accept any packets from other interfaces */
915 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
918 if (p
->family
!= t
->scope
->family
)
921 /* Tentative packets are not full responses but still
922 * useful for identifying uniqueness conflicts during
924 if (DNS_PACKET_LLMNR_T(p
)) {
925 dns_transaction_tentative(t
, p
);
931 case DNS_PROTOCOL_MDNS
:
932 /* For mDNS we will not accept any packets from other interfaces */
934 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
937 if (p
->family
!= t
->scope
->family
)
942 case DNS_PROTOCOL_DNS
:
943 /* Note that we do not need to verify the
944 * addresses/port numbers of incoming traffic, as we
945 * invoked connect() on our UDP socket in which case
946 * the kernel already does the needed verification for
951 assert_not_reached("Invalid DNS protocol.");
954 if (t
->received
!= p
) {
955 dns_packet_unref(t
->received
);
956 t
->received
= dns_packet_ref(p
);
959 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
961 if (p
->ipproto
== IPPROTO_TCP
) {
962 if (DNS_PACKET_TC(p
)) {
963 /* Truncated via TCP? Somebody must be fucking with us */
964 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
968 if (DNS_PACKET_ID(p
) != t
->id
) {
969 /* Not the reply to our query? Somebody must be fucking with us */
970 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
975 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
977 switch (t
->scope
->protocol
) {
979 case DNS_PROTOCOL_DNS
:
982 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
984 /* Request failed, immediately try again with reduced features */
986 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
988 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
989 * this transaction anymore, but let's see if it might make sense to send the request
990 * to a different DNS server instead. If not let's process the response, and accept the
991 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
992 * packet loss, but is not going to give us better rcodes should we actually have
993 * managed to get them already at UDP level. */
995 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
996 /* We tried fewer servers on this transaction than we know, let's try another one then */
997 dns_transaction_retry(t
, true);
1001 /* Give up, accept the rcode */
1002 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1006 /* Reduce this feature level by one and try again. */
1007 switch (t
->current_feature_level
) {
1008 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1009 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1011 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1012 /* Skip plain TLS when TLS is not supported */
1013 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1016 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1019 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1020 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1021 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1023 dns_transaction_retry(t
, false /* use the same server */);
1027 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1028 /* This server refused our request? If so, try again, use a different server */
1029 log_debug("Server returned REFUSED, switching servers, and retrying.");
1030 dns_transaction_retry(t
, true /* pick a new server */);
1034 if (DNS_PACKET_TC(p
))
1035 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1039 case DNS_PROTOCOL_LLMNR
:
1040 case DNS_PROTOCOL_MDNS
:
1041 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1045 assert_not_reached("Invalid DNS protocol.");
1048 if (DNS_PACKET_TC(p
)) {
1050 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1051 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1052 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1056 log_debug("Reply truncated, retrying via TCP.");
1058 /* Response was truncated, let's try again with good old TCP */
1059 r
= dns_transaction_emit_tcp(t
);
1061 /* No servers found? Damn! */
1062 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1065 if (r
== -EOPNOTSUPP
) {
1066 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1067 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1071 /* On LLMNR, if we cannot connect to the host,
1072 * we immediately give up */
1073 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1076 /* On DNS, couldn't send? Try immediately again, with a new server */
1077 dns_transaction_retry(t
, true);
1083 /* After the superficial checks, actually parse the message. */
1084 r
= dns_packet_extract(p
);
1086 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1091 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1092 * rcode and subsequently downgraded the protocol */
1094 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1095 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1096 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1098 /* Report that the OPT RR was missing */
1100 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1102 /* Report that we successfully received a packet */
1103 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1106 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1107 r
= dns_transaction_maybe_restart(t
);
1110 if (r
> 0) /* Transaction got restarted... */
1113 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1115 /* When dealing with protocols other than mDNS only consider responses with
1116 * equivalent query section to the request. For mDNS this check doesn't make
1117 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1118 * contain any questions in the Question Section". */
1119 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1120 r
= dns_packet_is_reply_for(p
, t
->key
);
1124 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1129 /* Install the answer as answer to the transaction */
1130 dns_answer_unref(t
->answer
);
1131 t
->answer
= dns_answer_ref(p
->answer
);
1132 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1133 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1134 t
->answer_authenticated
= false;
1136 r
= dns_transaction_fix_rcode(t
);
1140 /* Block GC while starting requests for additional DNSSEC RRs */
1142 r
= dns_transaction_request_dnssec_keys(t
);
1145 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1146 if (!dns_transaction_gc(t
))
1149 /* Requesting additional keys might have resulted in
1150 * this transaction to fail, since the auxiliary
1151 * request failed for some reason. If so, we are not
1152 * in pending state anymore, and we should exit
1154 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1159 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1160 t
->state
= DNS_TRANSACTION_VALIDATING
;
1161 dns_transaction_close_connection(t
);
1162 dns_transaction_stop_timeout(t
);
1167 dns_transaction_process_dnssec(t
);
1171 t
->answer_errno
= -r
;
1172 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1175 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1176 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1177 DnsTransaction
*t
= userdata
;
1183 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1184 if (ERRNO_IS_DISCONNECT(-r
)) {
1187 /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next
1188 * recvmsg(). Treat this like a lost packet. */
1190 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1191 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1192 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1194 dns_transaction_retry(t
, true);
1198 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1199 t
->answer_errno
= -r
;
1203 r
= dns_packet_validate_reply(p
);
1205 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1209 log_debug("Received inappropriate DNS packet as response, ignoring.");
1213 if (DNS_PACKET_ID(p
) != t
->id
) {
1214 log_debug("Received packet with incorrect transaction ID, ignoring.");
1218 dns_transaction_process_reply(t
, p
);
1222 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1227 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1229 r
= dns_transaction_pick_server(t
);
1233 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1234 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1236 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1239 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1242 dns_transaction_close_connection(t
);
1244 fd
= dns_scope_socket_udp(t
->scope
, t
->server
, 53);
1248 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1254 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1258 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1262 dns_transaction_close_connection(t
);
1264 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1268 dns_transaction_reset_answer(t
);
1273 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1274 DnsTransaction
*t
= userdata
;
1279 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1280 /* Timeout reached? Increase the timeout for the server used */
1281 switch (t
->scope
->protocol
) {
1283 case DNS_PROTOCOL_DNS
:
1285 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1288 case DNS_PROTOCOL_LLMNR
:
1289 case DNS_PROTOCOL_MDNS
:
1290 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1294 assert_not_reached("Invalid DNS protocol.");
1297 if (t
->initial_jitter_scheduled
)
1298 t
->initial_jitter_elapsed
= true;
1301 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1303 dns_transaction_retry(t
, true);
1307 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1311 switch (t
->scope
->protocol
) {
1313 case DNS_PROTOCOL_DNS
:
1315 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1316 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1319 return TRANSACTION_TCP_TIMEOUT_USEC
;
1321 return DNS_TIMEOUT_USEC
;
1323 case DNS_PROTOCOL_MDNS
:
1324 assert(t
->n_attempts
> 0);
1326 return MDNS_PROBING_INTERVAL_USEC
;
1328 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1330 case DNS_PROTOCOL_LLMNR
:
1331 return t
->scope
->resend_timeout
;
1334 assert_not_reached("Invalid DNS protocol.");
1338 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1343 dns_transaction_stop_timeout(t
);
1345 if (!dns_scope_network_good(t
->scope
)) {
1346 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1350 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1351 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1355 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1356 /* If we already tried via a stream, then we don't
1357 * retry on LLMNR. See RFC 4795, Section 2.7. */
1358 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1365 dns_transaction_reset_answer(t
);
1366 dns_transaction_flush_dnssec_transactions(t
);
1368 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1369 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1370 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1374 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1375 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1376 t
->answer_authenticated
= true;
1377 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1381 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1382 t
->key
->type
== DNS_TYPE_DS
) {
1384 /* Hmm, this is a request for the root DS? A
1385 * DS RR doesn't exist in the root zone, and
1386 * if our trust anchor didn't know it either,
1387 * this means we cannot do any DNSSEC logic
1390 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1391 /* We are in downgrade mode. In this
1392 * case, synthesize an unsigned empty
1393 * response, so that the any lookup
1394 * depending on this one can continue
1395 * assuming there was no DS, and hence
1396 * the root zone was unsigned. */
1398 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1399 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1400 t
->answer_authenticated
= false;
1401 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1403 /* If we are not in downgrade mode,
1404 * then fail the lookup, because we
1405 * cannot reasonably answer it. There
1406 * might be DS RRs, but we don't know
1407 * them, and the DNS server won't tell
1408 * them to us (and even if it would,
1409 * we couldn't validate and trust them. */
1410 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1416 /* Check the zone, but only if this transaction is not used
1417 * for probing or verifying a zone item. */
1418 if (set_isempty(t
->notify_zone_items
)) {
1420 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1424 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1425 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1426 t
->answer_authenticated
= true;
1427 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1432 /* Check the cache, but only if this transaction is not used
1433 * for probing or verifying a zone item. */
1434 if (set_isempty(t
->notify_zone_items
)) {
1436 /* Before trying the cache, let's make sure we figured out a
1437 * server to use. Should this cause a change of server this
1438 * might flush the cache. */
1439 (void) dns_scope_get_dns_server(t
->scope
);
1441 /* Let's then prune all outdated entries */
1442 dns_cache_prune(&t
->scope
->cache
);
1444 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1448 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1449 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1450 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1452 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1460 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1462 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1463 bool add_known_answers
= false;
1464 DnsTransaction
*other
;
1466 DnsResourceKey
*tkey
;
1467 _cleanup_set_free_ Set
*keys
= NULL
;
1469 unsigned nscount
= 0;
1474 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1476 /* Discard any previously prepared packet, so we can start over and coalesce again */
1477 t
->sent
= dns_packet_unref(t
->sent
);
1479 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1483 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1489 if (dns_key_is_shared(t
->key
))
1490 add_known_answers
= true;
1492 if (t
->key
->type
== DNS_TYPE_ANY
) {
1493 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1497 r
= set_put(keys
, t
->key
);
1503 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1504 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1505 * in our current scope, and see whether their timing contraints allow them to be sent.
1508 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1510 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1512 /* Skip ourselves */
1516 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1519 if (other
->next_attempt_after
> ts
)
1522 if (qdcount
>= UINT16_MAX
)
1525 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1528 * If we can't stuff more questions into the packet, just give up.
1529 * One of the 'other' transactions will fire later and take care of the rest.
1537 r
= dns_transaction_prepare(other
, ts
);
1541 ts
+= transaction_get_resend_timeout(other
);
1543 r
= sd_event_add_time(
1544 other
->scope
->manager
->event
,
1545 &other
->timeout_event_source
,
1546 clock_boottime_or_monotonic(),
1548 on_transaction_timeout
, other
);
1552 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1554 other
->state
= DNS_TRANSACTION_PENDING
;
1555 other
->next_attempt_after
= ts
;
1559 if (dns_key_is_shared(other
->key
))
1560 add_known_answers
= true;
1562 if (other
->key
->type
== DNS_TYPE_ANY
) {
1563 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1567 r
= set_put(keys
, other
->key
);
1573 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1575 /* Append known answer section if we're asking for any shared record */
1576 if (add_known_answers
) {
1577 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1582 SET_FOREACH(tkey
, keys
, i
) {
1583 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1586 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1590 r
= dns_packet_append_answer(p
, answer
);
1594 nscount
+= dns_answer_size(answer
);
1596 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1598 t
->sent
= TAKE_PTR(p
);
1603 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1604 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1609 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1610 return dns_transaction_make_packet_mdns(t
);
1615 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1619 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1623 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1624 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1626 t
->sent
= TAKE_PTR(p
);
1631 int dns_transaction_go(DnsTransaction
*t
) {
1634 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1638 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1641 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1643 r
= dns_transaction_prepare(t
, ts
);
1647 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1649 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1650 dns_protocol_to_string(t
->scope
->protocol
),
1651 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
1652 af_to_name_short(t
->scope
->family
));
1654 if (!t
->initial_jitter_scheduled
&&
1655 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1656 usec_t jitter
, accuracy
;
1658 /* RFC 4795 Section 2.7 suggests all queries should be
1659 * delayed by a random time from 0 to JITTER_INTERVAL. */
1661 t
->initial_jitter_scheduled
= true;
1663 random_bytes(&jitter
, sizeof(jitter
));
1665 switch (t
->scope
->protocol
) {
1667 case DNS_PROTOCOL_LLMNR
:
1668 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1669 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1672 case DNS_PROTOCOL_MDNS
:
1673 jitter
%= MDNS_JITTER_RANGE_USEC
;
1674 jitter
+= MDNS_JITTER_MIN_USEC
;
1675 accuracy
= MDNS_JITTER_RANGE_USEC
;
1678 assert_not_reached("bad protocol");
1681 r
= sd_event_add_time(
1682 t
->scope
->manager
->event
,
1683 &t
->timeout_event_source
,
1684 clock_boottime_or_monotonic(),
1685 ts
+ jitter
, accuracy
,
1686 on_transaction_timeout
, t
);
1690 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1693 t
->next_attempt_after
= ts
;
1694 t
->state
= DNS_TRANSACTION_PENDING
;
1696 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1700 /* Otherwise, we need to ask the network */
1701 r
= dns_transaction_make_packet(t
);
1705 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1706 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1707 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1709 /* RFC 4795, Section 2.4. says reverse lookups shall
1710 * always be made via TCP on LLMNR */
1711 r
= dns_transaction_emit_tcp(t
);
1713 /* Try via UDP, and if that fails due to large size or lack of
1714 * support try via TCP */
1715 r
= dns_transaction_emit_udp(t
);
1717 log_debug("Sending query via TCP since it is too large.");
1718 else if (r
== -EAGAIN
)
1719 log_debug("Sending query via TCP since UDP isn't supported.");
1720 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1721 r
= dns_transaction_emit_tcp(t
);
1725 /* No servers to send this to? */
1726 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1729 if (r
== -EOPNOTSUPP
) {
1730 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1731 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1734 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1735 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1736 * answer this request with this protocol. */
1737 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1741 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1744 /* Couldn't send? Try immediately again, with a new server */
1745 dns_scope_next_dns_server(t
->scope
);
1747 return dns_transaction_go(t
);
1750 ts
+= transaction_get_resend_timeout(t
);
1752 r
= sd_event_add_time(
1753 t
->scope
->manager
->event
,
1754 &t
->timeout_event_source
,
1755 clock_boottime_or_monotonic(),
1757 on_transaction_timeout
, t
);
1761 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1763 t
->state
= DNS_TRANSACTION_PENDING
;
1764 t
->next_attempt_after
= ts
;
1769 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1777 /* Try to find cyclic dependencies between transaction objects */
1782 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1783 r
= dns_transaction_find_cyclic(t
, n
);
1791 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1792 DnsTransaction
*aux
;
1799 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1801 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1805 if (set_contains(t
->dnssec_transactions
, aux
)) {
1810 r
= dns_transaction_find_cyclic(t
, aux
);
1814 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1816 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1817 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1819 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1821 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1825 r
= set_ensure_allocated(&t
->dnssec_transactions
, NULL
);
1829 r
= set_ensure_allocated(&aux
->notify_transactions
, NULL
);
1833 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1837 r
= set_put(t
->dnssec_transactions
, aux
);
1841 r
= set_put(aux
->notify_transactions
, t
);
1843 (void) set_remove(t
->dnssec_transactions
, aux
);
1851 dns_transaction_gc(aux
);
1855 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1856 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1857 DnsTransaction
*aux
;
1863 /* Try to get the data from the trust anchor */
1864 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1868 r
= dns_answer_extend(&t
->validated_keys
, a
);
1875 /* This didn't work, ask for it via the network/cache then. */
1876 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1877 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1882 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1883 r
= dns_transaction_go(aux
);
1891 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1896 /* Check whether the specified name is in the NTA
1897 * database, either in the global one, or the link-local
1900 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1904 if (!t
->scope
->link
)
1907 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1910 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1915 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1916 * RRs to prove it */
1918 r
= dns_transaction_has_positive_answer(t
, NULL
);
1924 /* Is this key explicitly listed as a negative trust anchor?
1925 * If so, it's nothing we need to care about */
1926 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1932 /* The answer does not contain any RRs that match to the
1933 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1934 * included. If not, the answer is unsigned. */
1936 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1945 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1951 /* Check if the specified RR is the "primary" response,
1952 * i.e. either matches the question precisely or is a
1953 * CNAME/DNAME for it. */
1955 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1959 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1962 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1965 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1966 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1968 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1971 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1972 * be supported, hence return true. */
1976 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1977 * the server is known to support currently, as the transaction feature level might be lower than what the
1978 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1979 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1981 return dns_server_dnssec_supported(t
->server
);
1984 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1990 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1992 if (!dns_transaction_dnssec_supported(t
))
1995 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1996 if (!dns_transaction_dnssec_supported(dt
))
2002 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
2003 DnsResourceRecord
*rr
;
2010 * Retrieve all auxiliary RRs for the answer we got, so that
2011 * we can verify signatures or prove that RRs are rightfully
2012 * unsigned. Specifically:
2014 * - For RRSIG we get the matching DNSKEY
2015 * - For DNSKEY we get the matching DS
2016 * - For unsigned SOA/NS we get the matching DS
2017 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2018 * - For other unsigned RRs we get the matching SOA RR
2019 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2020 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2021 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2024 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2026 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2027 return 0; /* We only need to validate stuff from the network */
2028 if (!dns_transaction_dnssec_supported(t
))
2029 return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */
2031 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2033 if (dns_type_is_pseudo(rr
->key
->type
))
2036 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2037 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2043 switch (rr
->key
->type
) {
2045 case DNS_TYPE_RRSIG
: {
2046 /* For each RRSIG we request the matching DNSKEY */
2047 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2049 /* If this RRSIG is about a DNSKEY RR and the
2050 * signer is the same as the owner, then we
2051 * already have the DNSKEY, and we don't have
2052 * to look for more. */
2053 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2054 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2061 /* If the signer is not a parent of our
2062 * original query, then this is about an
2063 * auxiliary RRset, but not anything we asked
2064 * for. In this case we aren't interested,
2065 * because we don't want to request additional
2066 * RRs for stuff we didn't really ask for, and
2067 * also to avoid request loops, where
2068 * additional RRs from one transaction result
2069 * in another transaction whose additonal RRs
2070 * point back to the original transaction, and
2072 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2078 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2082 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2083 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2084 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2090 case DNS_TYPE_DNSKEY
: {
2091 /* For each DNSKEY we request the matching DS */
2092 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2094 /* If the DNSKEY we are looking at is not for
2095 * zone we are interested in, nor any of its
2096 * parents, we aren't interested, and don't
2097 * request it. After all, we don't want to end
2098 * up in request loops, and want to keep
2099 * additional traffic down. */
2101 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2107 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2111 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2112 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2113 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2122 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2124 /* For an unsigned SOA or NS, try to acquire
2125 * the matching DS RR, as we are at a zone cut
2126 * then, and whether a DS exists tells us
2127 * whether the zone is signed. Do so only if
2128 * this RR matches our original question,
2131 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2135 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2136 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2137 * If so, we need to validate it, too. */
2139 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2142 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2146 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2147 * what we are looking for, otherwise there's no value in it for us. */
2148 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2155 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2161 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2165 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2166 t
->id
, dns_resource_key_name(rr
->key
));
2167 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2175 case DNS_TYPE_CNAME
:
2176 case DNS_TYPE_DNAME
: {
2177 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2180 /* CNAMEs and DNAMEs cannot be located at a
2181 * zone apex, hence ask for the parent SOA for
2182 * unsigned CNAME/DNAME RRs, maybe that's the
2183 * apex. But do all that only if this is
2184 * actually a response to our original
2187 * Similar for DS RRs, which are signed when
2188 * the parent SOA is signed. */
2190 r
= dns_transaction_is_primary_response(t
, rr
);
2196 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2202 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2208 name
= dns_resource_key_name(rr
->key
);
2209 r
= dns_name_parent(&name
);
2215 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2219 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2220 t
->id
, dns_resource_key_name(rr
->key
));
2221 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2229 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2231 /* For other unsigned RRsets (including
2232 * NSEC/NSEC3!), look for proof the zone is
2233 * unsigned, by requesting the SOA RR of the
2234 * zone. However, do so only if they are
2235 * directly relevant to our original
2238 r
= dns_transaction_is_primary_response(t
, rr
);
2244 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2250 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2254 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2255 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2256 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2263 /* Above, we requested everything necessary to validate what
2264 * we got. Now, let's request what we need to validate what we
2267 r
= dns_transaction_has_unsigned_negative_answer(t
);
2274 name
= dns_resource_key_name(t
->key
);
2276 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2277 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2278 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2279 * though they have further children. If this was a DS request, then it's signed when the parent zone
2280 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2281 * to see if that is signed. */
2283 if (t
->key
->type
== DNS_TYPE_DS
) {
2284 r
= dns_name_parent(&name
);
2286 type
= DNS_TYPE_SOA
;
2287 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2288 name
, t
->id
, dns_resource_key_name(t
->key
));
2292 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2295 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2299 type
= DNS_TYPE_SOA
;
2300 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2305 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2307 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2311 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2317 return dns_transaction_dnssec_is_live(t
);
2320 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2324 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2325 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2326 the state is VALIDATING however, we should check if we are complete now. */
2328 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2329 dns_transaction_process_dnssec(t
);
2332 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2333 DnsResourceRecord
*rr
;
2338 /* Add all DNSKEY RRs from the answer that are validated by DS
2339 * RRs from the list of validated keys to the list of
2340 * validated keys. */
2342 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2344 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2350 /* If so, the DNSKEY is validated too. */
2351 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2359 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2365 /* Checks if the RR we are looking for must be signed with an
2366 * RRSIG. This is used for positive responses. */
2368 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2371 if (dns_type_is_pseudo(rr
->key
->type
))
2374 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2380 switch (rr
->key
->type
) {
2382 case DNS_TYPE_RRSIG
:
2383 /* RRSIGs are the signatures themselves, they need no signing. */
2391 /* For SOA or NS RRs we look for a matching DS transaction */
2393 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2395 if (dt
->key
->class != rr
->key
->class)
2397 if (dt
->key
->type
!= DNS_TYPE_DS
)
2400 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2406 /* We found a DS transactions for the SOA/NS
2407 * RRs we are looking at. If it discovered signed DS
2408 * RRs, then we need to be signed, too. */
2410 if (!dt
->answer_authenticated
)
2413 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2416 /* We found nothing that proves this is safe to leave
2417 * this unauthenticated, hence ask inist on
2418 * authentication. */
2423 case DNS_TYPE_CNAME
:
2424 case DNS_TYPE_DNAME
: {
2425 const char *parent
= NULL
;
2430 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2432 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2435 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2437 if (dt
->key
->class != rr
->key
->class)
2439 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2443 parent
= dns_resource_key_name(rr
->key
);
2444 r
= dns_name_parent(&parent
);
2448 if (rr
->key
->type
== DNS_TYPE_DS
)
2451 /* A CNAME/DNAME without a parent? That's sooo weird. */
2452 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2453 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2457 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2463 return t
->answer_authenticated
;
2473 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2475 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2477 if (dt
->key
->class != rr
->key
->class)
2479 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2482 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2488 /* We found the transaction that was supposed to find
2489 * the SOA RR for us. It was successful, but found no
2490 * RR for us. This means we are not at a zone cut. In
2491 * this case, we require authentication if the SOA
2492 * lookup was authenticated too. */
2493 return t
->answer_authenticated
;
2500 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2506 /* If DNSSEC downgrade mode is on, checks whether the
2507 * specified RR is one level below a TLD we have proven not to
2508 * exist. In such a case we assume that this is a private
2509 * domain, and permit it.
2511 * This detects cases like the Fritz!Box router networks. Each
2512 * Fritz!Box router serves a private "fritz.box" zone, in the
2513 * non-existing TLD "box". Requests for the "fritz.box" domain
2514 * are served by the router itself, while requests for the
2515 * "box" domain will result in NXDOMAIN.
2517 * Note that this logic is unable to detect cases where a
2518 * router serves a private DNS zone directly under
2519 * non-existing TLD. In such a case we cannot detect whether
2520 * the TLD is supposed to exist or not, as all requests we
2521 * make for it will be answered by the router's zone, and not
2522 * by the root zone. */
2526 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2527 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2529 tld
= dns_resource_key_name(key
);
2530 r
= dns_name_parent(&tld
);
2534 return false; /* Already the root domain */
2536 if (!dns_name_is_single_label(tld
))
2539 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2541 if (dt
->key
->class != key
->class)
2544 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2550 /* We found an auxiliary lookup we did for the TLD. If
2551 * that returned with NXDOMAIN, we know the TLD didn't
2552 * exist, and hence this might be a private zone. */
2554 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2560 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2561 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2570 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2571 * this negative reply */
2573 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2576 if (dns_type_is_pseudo(t
->key
->type
))
2579 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2585 r
= dns_transaction_in_private_tld(t
, t
->key
);
2589 /* The lookup is from a TLD that is proven not to
2590 * exist, and we are in downgrade mode, hence ignore
2591 * that fact that we didn't get any NSEC RRs. */
2593 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2594 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2598 name
= dns_resource_key_name(t
->key
);
2600 if (t
->key
->type
== DNS_TYPE_DS
) {
2602 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2603 * hence check the parent SOA in this case. */
2605 r
= dns_name_parent(&name
);
2611 type
= DNS_TYPE_SOA
;
2613 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2614 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2617 /* For all other negative replies, check for the SOA lookup */
2618 type
= DNS_TYPE_SOA
;
2620 /* For all other RRs we check the SOA on the same level to see
2621 * if it's signed. */
2623 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2625 if (dt
->key
->class != t
->key
->class)
2627 if (dt
->key
->type
!= type
)
2630 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2636 return dt
->answer_authenticated
;
2639 /* If in doubt, require NSEC/NSEC3 */
2643 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2644 DnsResourceRecord
*rrsig
;
2648 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2649 * the specified RRset is authenticated (i.e. has a matching
2652 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2658 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2662 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2668 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2670 if (dt
->key
->class != rr
->key
->class)
2673 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2675 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2681 /* OK, we found an auxiliary DNSKEY
2682 * lookup. If that lookup is
2683 * authenticated, report this. */
2685 if (dt
->answer_authenticated
)
2690 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2692 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2698 /* OK, we found an auxiliary DS
2699 * lookup. If that lookup is
2700 * authenticated and non-zero, we
2703 if (!dt
->answer_authenticated
)
2706 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2711 return found
? false : -ENXIO
;
2714 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2718 /* We know that the root domain is signed, hence if it appears
2719 * not to be signed, there's a problem with the DNS server */
2721 return rr
->key
->class == DNS_CLASS_IN
&&
2722 dns_name_is_root(dns_resource_key_name(rr
->key
));
2725 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2726 DnsResourceRecord
*rr
;
2731 /* Maybe warn the user that we encountered a revoked DNSKEY
2732 * for a key from our trust anchor. Note that we don't care
2733 * whether the DNSKEY can be authenticated or not. It's
2734 * sufficient if it is self-signed. */
2736 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2737 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2745 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2751 /* Removes all DNSKEY/DS objects from t->validated_keys that
2752 * our trust anchors database considers revoked. */
2755 DnsResourceRecord
*rr
;
2759 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2760 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2764 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2778 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2785 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2787 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2789 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2792 if (!dt
->answer_authenticated
)
2795 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2804 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2805 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2806 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2809 static int dnssec_validate_records(
2813 DnsAnswer
**validated
) {
2815 DnsResourceRecord
*rr
;
2818 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2820 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2821 DnsResourceRecord
*rrsig
= NULL
;
2822 DnssecResult result
;
2824 switch (rr
->key
->type
) {
2825 case DNS_TYPE_RRSIG
:
2828 case DNS_TYPE_DNSKEY
:
2829 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2830 if (phase
== DNSSEC_PHASE_NSEC
)
2835 case DNS_TYPE_NSEC3
:
2838 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2839 if (phase
== DNSSEC_PHASE_DNSKEY
)
2844 /* We validate all other RRs only in the ALL phases */
2845 if (phase
!= DNSSEC_PHASE_ALL
)
2849 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2853 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2855 if (result
== DNSSEC_VALIDATED
) {
2857 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2858 /* If we just validated a DNSKEY RRset, then let's add these keys to
2859 * the set of validated keys for this transaction. */
2861 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2865 /* Some of the DNSKEYs we just added might already have been revoked,
2866 * remove them again in that case. */
2867 r
= dns_transaction_invalidate_revoked_keys(t
);
2872 /* Add the validated RRset to the new list of validated
2873 * RRsets, and remove it from the unvalidated RRsets.
2874 * We mark the RRset as authenticated and cacheable. */
2875 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2879 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2881 /* Exit the loop, we dropped something from the answer, start from the beginning */
2885 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2886 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2887 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2888 if (phase
!= DNSSEC_PHASE_ALL
)
2891 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2892 bool authenticated
= false;
2895 /* This RRset validated, but as a wildcard. This means we need
2896 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2898 /* First step, determine the source of synthesis */
2899 r
= dns_resource_record_source(rrsig
, &source
);
2903 r
= dnssec_test_positive_wildcard(*validated
,
2904 dns_resource_key_name(rr
->key
),
2906 rrsig
->rrsig
.signer
,
2909 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2911 result
= DNSSEC_INVALID
;
2913 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2914 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2918 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2920 /* Exit the loop, we dropped something from the answer, start from the beginning */
2925 if (result
== DNSSEC_NO_SIGNATURE
) {
2926 r
= dns_transaction_requires_rrsig(t
, rr
);
2930 /* Data does not require signing. In that case, just copy it over,
2931 * but remember that this is by no means authenticated. */
2932 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2936 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2940 r
= dns_transaction_known_signed(t
, rr
);
2944 /* This is an RR we know has to be signed. If it isn't this means
2945 * the server is not attaching RRSIGs, hence complain. */
2947 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2949 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2951 /* Downgrading is OK? If so, just consider the information unsigned */
2953 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2957 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2961 /* Otherwise, fail */
2962 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2966 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2970 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2972 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2973 * mode, hence ignore the fact that this was not signed. */
2975 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2976 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2978 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2982 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2989 DNSSEC_SIGNATURE_EXPIRED
,
2990 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2992 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2993 if (r
< 0 && r
!= -ENXIO
)
2996 /* The DNSKEY transaction was not authenticated, this means there's
2997 * no DS for this, which means it's OK if no keys are found for this signature. */
2999 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
3003 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
3008 r
= dns_transaction_is_primary_response(t
, rr
);
3012 /* Look for a matching DNAME for this CNAME */
3013 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
3017 /* Also look among the stuff we already validated */
3018 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3026 DNSSEC_SIGNATURE_EXPIRED
,
3027 DNSSEC_NO_SIGNATURE
))
3028 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3029 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3030 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3032 /* This is a primary response to our question, and it failed validation.
3034 t
->answer_dnssec_result
= result
;
3038 /* This is a primary response, but we do have a DNAME RR
3039 * in the RR that can replay this CNAME, hence rely on
3040 * that, and we can remove the CNAME in favour of it. */
3043 /* This is just some auxiliary data. Just remove the RRset and continue. */
3044 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3048 /* We dropped something from the answer, start from the beginning. */
3052 return 2; /* Finito. */
3055 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3056 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3058 DnsAnswerFlags flags
;
3060 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3064 /* We have now collected all DS and DNSKEY RRs in
3065 * t->validated_keys, let's see which RRs we can now
3066 * authenticate with that. */
3068 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3071 /* Already validated */
3072 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3075 /* Our own stuff needs no validation */
3076 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3077 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3078 t
->answer_authenticated
= true;
3082 /* Cached stuff is not affected by validation. */
3083 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3086 if (!dns_transaction_dnssec_supported_full(t
)) {
3087 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3088 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3089 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3093 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3095 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3097 /* First, see if this response contains any revoked trust
3098 * anchors we care about */
3099 r
= dns_transaction_check_revoked_trust_anchors(t
);
3103 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3104 r
= dns_transaction_copy_validated(t
);
3108 /* Second, see if there are DNSKEYs we already know a
3109 * validated DS for. */
3110 r
= dns_transaction_validate_dnskey_by_ds(t
);
3114 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3115 * anchor says are revoked. After all we might have marked
3116 * some keys revoked above, but they might still be lingering
3117 * in our validated_keys list. */
3118 r
= dns_transaction_invalidate_revoked_keys(t
);
3122 phase
= DNSSEC_PHASE_DNSKEY
;
3124 bool have_nsec
= false;
3126 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3130 /* Try again as long as we managed to achieve something */
3134 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3135 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3136 phase
= DNSSEC_PHASE_NSEC
;
3140 if (phase
!= DNSSEC_PHASE_ALL
) {
3141 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3142 * Note that in this third phase we start to remove RRs we couldn't validate. */
3143 phase
= DNSSEC_PHASE_ALL
;
3151 dns_answer_unref(t
->answer
);
3152 t
->answer
= TAKE_PTR(validated
);
3154 /* At this point the answer only contains validated
3155 * RRsets. Now, let's see if it actually answers the question
3156 * we asked. If so, great! If it doesn't, then see if
3157 * NSEC/NSEC3 can prove this. */
3158 r
= dns_transaction_has_positive_answer(t
, &flags
);
3160 /* Yes, it answers the question! */
3162 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3163 /* The answer is fully authenticated, yay. */
3164 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3165 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3166 t
->answer_authenticated
= true;
3168 /* The answer is not fully authenticated. */
3169 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3170 t
->answer_authenticated
= false;
3173 } else if (r
== 0) {
3174 DnssecNsecResult nr
;
3175 bool authenticated
= false;
3177 /* Bummer! Let's check NSEC/NSEC3 */
3178 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3184 case DNSSEC_NSEC_NXDOMAIN
:
3185 /* NSEC proves the domain doesn't exist. Very good. */
3186 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3187 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3188 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3189 t
->answer_authenticated
= authenticated
;
3191 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3194 case DNSSEC_NSEC_NODATA
:
3195 /* NSEC proves that there's no data here, very good. */
3196 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3197 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3198 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3199 t
->answer_authenticated
= authenticated
;
3201 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3204 case DNSSEC_NSEC_OPTOUT
:
3205 /* NSEC3 says the data might not be signed */
3206 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3207 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3208 t
->answer_authenticated
= false;
3210 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3213 case DNSSEC_NSEC_NO_RR
:
3214 /* No NSEC data? Bummer! */
3216 r
= dns_transaction_requires_nsec(t
);
3220 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3221 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3223 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3224 t
->answer_authenticated
= false;
3225 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3230 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3231 /* We don't know the NSEC3 algorithm used? */
3232 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3233 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3236 case DNSSEC_NSEC_FOUND
:
3237 case DNSSEC_NSEC_CNAME
:
3238 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3239 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3240 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3244 assert_not_reached("Unexpected NSEC result.");
3251 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3252 [DNS_TRANSACTION_NULL
] = "null",
3253 [DNS_TRANSACTION_PENDING
] = "pending",
3254 [DNS_TRANSACTION_VALIDATING
] = "validating",
3255 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3256 [DNS_TRANSACTION_SUCCESS
] = "success",
3257 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3258 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3259 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3260 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3261 [DNS_TRANSACTION_ERRNO
] = "errno",
3262 [DNS_TRANSACTION_ABORTED
] = "aborted",
3263 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3264 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3265 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3266 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3267 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3269 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3271 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3272 [DNS_TRANSACTION_NETWORK
] = "network",
3273 [DNS_TRANSACTION_CACHE
] = "cache",
3274 [DNS_TRANSACTION_ZONE
] = "zone",
3275 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3277 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);