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"
10 #include "random-util.h"
11 #include "resolved-dns-cache.h"
12 #include "resolved-dns-transaction.h"
13 #include "resolved-llmnr.h"
14 #if ENABLE_DNS_OVER_TLS
15 #include "resolved-dnstls.h"
17 #include "string-table.h"
19 #define TRANSACTIONS_MAX 4096
20 #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
22 /* After how much time to repeat classic DNS requests */
23 #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX)
25 static void dns_transaction_reset_answer(DnsTransaction
*t
) {
28 t
->received
= dns_packet_unref(t
->received
);
29 t
->answer
= dns_answer_unref(t
->answer
);
31 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
32 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
33 t
->answer_authenticated
= false;
34 t
->answer_nsec_ttl
= (uint32_t) -1;
38 static void dns_transaction_flush_dnssec_transactions(DnsTransaction
*t
) {
43 while ((z
= set_steal_first(t
->dnssec_transactions
))) {
44 set_remove(z
->notify_transactions
, t
);
45 set_remove(z
->notify_transactions_done
, t
);
46 dns_transaction_gc(z
);
50 static void dns_transaction_close_connection(DnsTransaction
*t
) {
54 /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
55 LIST_REMOVE(transactions_by_stream
, t
->stream
->transactions
, t
);
57 /* Remove packet in case it's still in the queue */
58 dns_packet_unref(ordered_set_remove(t
->stream
->write_queue
, t
->sent
));
60 t
->stream
= dns_stream_unref(t
->stream
);
63 t
->dns_udp_event_source
= sd_event_source_unref(t
->dns_udp_event_source
);
64 t
->dns_udp_fd
= safe_close(t
->dns_udp_fd
);
67 static void dns_transaction_stop_timeout(DnsTransaction
*t
) {
70 t
->timeout_event_source
= sd_event_source_unref(t
->timeout_event_source
);
73 DnsTransaction
* dns_transaction_free(DnsTransaction
*t
) {
81 log_debug("Freeing transaction %" PRIu16
".", t
->id
);
83 dns_transaction_close_connection(t
);
84 dns_transaction_stop_timeout(t
);
86 dns_packet_unref(t
->sent
);
87 dns_transaction_reset_answer(t
);
89 dns_server_unref(t
->server
);
92 hashmap_remove_value(t
->scope
->transactions_by_key
, t
->key
, t
);
93 LIST_REMOVE(transactions_by_scope
, t
->scope
->transactions
, t
);
96 hashmap_remove(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
99 while ((c
= set_steal_first(t
->notify_query_candidates
)))
100 set_remove(c
->transactions
, t
);
101 set_free(t
->notify_query_candidates
);
103 while ((c
= set_steal_first(t
->notify_query_candidates_done
)))
104 set_remove(c
->transactions
, t
);
105 set_free(t
->notify_query_candidates_done
);
107 while ((i
= set_steal_first(t
->notify_zone_items
)))
108 i
->probe_transaction
= NULL
;
109 set_free(t
->notify_zone_items
);
111 while ((i
= set_steal_first(t
->notify_zone_items_done
)))
112 i
->probe_transaction
= NULL
;
113 set_free(t
->notify_zone_items_done
);
115 while ((z
= set_steal_first(t
->notify_transactions
)))
116 set_remove(z
->dnssec_transactions
, t
);
117 set_free(t
->notify_transactions
);
119 while ((z
= set_steal_first(t
->notify_transactions_done
)))
120 set_remove(z
->dnssec_transactions
, t
);
121 set_free(t
->notify_transactions_done
);
123 dns_transaction_flush_dnssec_transactions(t
);
124 set_free(t
->dnssec_transactions
);
126 dns_answer_unref(t
->validated_keys
);
127 dns_resource_key_unref(t
->key
);
132 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction
*, dns_transaction_free
);
134 bool dns_transaction_gc(DnsTransaction
*t
) {
140 if (set_isempty(t
->notify_query_candidates
) &&
141 set_isempty(t
->notify_query_candidates_done
) &&
142 set_isempty(t
->notify_zone_items
) &&
143 set_isempty(t
->notify_zone_items_done
) &&
144 set_isempty(t
->notify_transactions
) &&
145 set_isempty(t
->notify_transactions_done
)) {
146 dns_transaction_free(t
);
153 static uint16_t pick_new_id(Manager
*m
) {
156 /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of
157 * transactions, and it's much lower than the space of IDs. */
159 assert_cc(TRANSACTIONS_MAX
< 0xFFFF);
162 random_bytes(&new_id
, sizeof(new_id
));
163 while (new_id
== 0 ||
164 hashmap_get(m
->dns_transactions
, UINT_TO_PTR(new_id
)));
169 int dns_transaction_new(DnsTransaction
**ret
, DnsScope
*s
, DnsResourceKey
*key
) {
170 _cleanup_(dns_transaction_freep
) DnsTransaction
*t
= NULL
;
177 /* Don't allow looking up invalid or pseudo RRs */
178 if (!dns_type_is_valid_query(key
->type
))
180 if (dns_type_is_obsolete(key
->type
))
183 /* We only support the IN class */
184 if (!IN_SET(key
->class, DNS_CLASS_IN
, DNS_CLASS_ANY
))
187 if (hashmap_size(s
->manager
->dns_transactions
) >= TRANSACTIONS_MAX
)
190 r
= hashmap_ensure_allocated(&s
->manager
->dns_transactions
, NULL
);
194 r
= hashmap_ensure_allocated(&s
->transactions_by_key
, &dns_resource_key_hash_ops
);
198 t
= new0(DnsTransaction
, 1);
203 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
204 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
205 t
->answer_nsec_ttl
= (uint32_t) -1;
206 t
->key
= dns_resource_key_ref(key
);
207 t
->current_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
208 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
210 t
->id
= pick_new_id(s
->manager
);
212 r
= hashmap_put(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), t
);
218 r
= hashmap_replace(s
->transactions_by_key
, t
->key
, t
);
220 hashmap_remove(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
224 LIST_PREPEND(transactions_by_scope
, s
->transactions
, t
);
227 s
->manager
->n_transactions_total
++;
237 static void dns_transaction_shuffle_id(DnsTransaction
*t
) {
241 /* Pick a new ID for this transaction. */
243 new_id
= pick_new_id(t
->scope
->manager
);
244 assert_se(hashmap_remove_and_put(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), UINT_TO_PTR(new_id
), t
) >= 0);
246 log_debug("Transaction %" PRIu16
" is now %" PRIu16
".", t
->id
, new_id
);
249 /* Make sure we generate a new packet with the new ID */
250 t
->sent
= dns_packet_unref(t
->sent
);
253 static void dns_transaction_tentative(DnsTransaction
*t
, DnsPacket
*p
) {
254 _cleanup_free_
char *pretty
= NULL
;
255 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
261 if (manager_our_packet(t
->scope
->manager
, p
) != 0)
264 (void) in_addr_to_string(p
->family
, &p
->sender
, &pretty
);
266 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s got tentative packet from %s.",
268 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
269 dns_protocol_to_string(t
->scope
->protocol
),
270 t
->scope
->link
? t
->scope
->link
->name
: "*",
271 af_to_name_short(t
->scope
->family
),
274 /* RFC 4795, Section 4.1 says that the peer with the
275 * lexicographically smaller IP address loses */
276 if (memcmp(&p
->sender
, &p
->destination
, FAMILY_ADDRESS_SIZE(p
->family
)) >= 0) {
277 log_debug("Peer has lexicographically larger IP address and thus lost in the conflict.");
281 log_debug("We have the lexicographically larger IP address and thus lost in the conflict.");
285 while ((z
= set_first(t
->notify_zone_items
))) {
286 /* First, make sure the zone item drops the reference
288 dns_zone_item_probe_stop(z
);
290 /* Secondly, report this as conflict, so that we might
291 * look for a different hostname */
292 dns_zone_item_conflict(z
);
296 dns_transaction_gc(t
);
299 void dns_transaction_complete(DnsTransaction
*t
, DnsTransactionState state
) {
300 DnsQueryCandidate
*c
;
304 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
307 assert(!DNS_TRANSACTION_IS_LIVE(state
));
309 if (state
== DNS_TRANSACTION_DNSSEC_FAILED
) {
310 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
);
312 log_struct(LOG_NOTICE
,
313 "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR
,
314 LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str
, dnssec_result_to_string(t
->answer_dnssec_result
)),
315 "DNS_TRANSACTION=%" PRIu16
, t
->id
,
316 "DNS_QUESTION=%s", key_str
,
317 "DNSSEC_RESULT=%s", dnssec_result_to_string(t
->answer_dnssec_result
),
318 "DNS_SERVER=%s", dns_server_string(t
->server
),
319 "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t
->server
->possible_feature_level
));
322 /* Note that this call might invalidate the query. Callers
323 * should hence not attempt to access the query or transaction
324 * after calling this function. */
326 if (state
== DNS_TRANSACTION_ERRNO
)
327 st
= errno_to_name(t
->answer_errno
);
329 st
= dns_transaction_state_to_string(state
);
331 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).",
333 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
334 dns_protocol_to_string(t
->scope
->protocol
),
335 t
->scope
->link
? t
->scope
->link
->name
: "*",
336 af_to_name_short(t
->scope
->family
),
338 t
->answer_source
< 0 ? "none" : dns_transaction_source_to_string(t
->answer_source
),
339 t
->answer_authenticated
? "authenticated" : "unsigned");
343 dns_transaction_close_connection(t
);
344 dns_transaction_stop_timeout(t
);
346 /* Notify all queries that are interested, but make sure the
347 * transaction isn't freed while we are still looking at it */
350 SET_FOREACH_MOVE(c
, t
->notify_query_candidates_done
, t
->notify_query_candidates
)
351 dns_query_candidate_notify(c
);
352 SWAP_TWO(t
->notify_query_candidates
, t
->notify_query_candidates_done
);
354 SET_FOREACH_MOVE(z
, t
->notify_zone_items_done
, t
->notify_zone_items
)
355 dns_zone_item_notify(z
);
356 SWAP_TWO(t
->notify_zone_items
, t
->notify_zone_items_done
);
357 if (t
->probing
&& t
->state
== DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
)
358 (void) dns_scope_announce(t
->scope
, false);
360 SET_FOREACH_MOVE(d
, t
->notify_transactions_done
, t
->notify_transactions
)
361 dns_transaction_notify(d
, t
);
362 SWAP_TWO(t
->notify_transactions
, t
->notify_transactions_done
);
365 dns_transaction_gc(t
);
368 static int dns_transaction_pick_server(DnsTransaction
*t
) {
372 assert(t
->scope
->protocol
== DNS_PROTOCOL_DNS
);
374 /* Pick a DNS server and a feature level for it. */
376 server
= dns_scope_get_dns_server(t
->scope
);
380 /* If we changed the server invalidate the feature level clamping, as the new server might have completely
381 * different properties. */
382 if (server
!= t
->server
)
383 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
385 t
->current_feature_level
= dns_server_possible_feature_level(server
);
387 /* Clamp the feature level if that is requested. */
388 if (t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
&&
389 t
->current_feature_level
> t
->clamp_feature_level
)
390 t
->current_feature_level
= t
->clamp_feature_level
;
392 log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t
->current_feature_level
), t
->id
);
394 if (server
== t
->server
)
397 dns_server_unref(t
->server
);
398 t
->server
= dns_server_ref(server
);
400 t
->n_picked_servers
++;
402 log_debug("Using DNS server %s for transaction %u.", dns_server_string(t
->server
), t
->id
);
407 static void dns_transaction_retry(DnsTransaction
*t
, bool next_server
) {
412 log_debug("Retrying transaction %" PRIu16
".", t
->id
);
414 /* Before we try again, switch to a new server. */
416 dns_scope_next_dns_server(t
->scope
);
418 r
= dns_transaction_go(t
);
420 t
->answer_errno
= -r
;
421 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
425 static int dns_transaction_maybe_restart(DnsTransaction
*t
) {
430 /* Returns > 0 if the transaction was restarted, 0 if not */
435 if (t
->current_feature_level
<= dns_server_possible_feature_level(t
->server
))
438 /* The server's current feature level is lower than when we sent the original query. We learnt something from
439 the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to
440 restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include
441 OPT RR or DO bit. One of these cases is documented here, for example:
442 https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */
444 log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID.");
445 dns_transaction_shuffle_id(t
);
447 r
= dns_transaction_go(t
);
454 static void on_transaction_stream_error(DnsTransaction
*t
, int error
) {
457 dns_transaction_close_connection(t
);
459 if (ERRNO_IS_DISCONNECT(error
)) {
460 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
) {
461 /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
462 * question on this scope. */
463 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
467 dns_transaction_retry(t
, true);
471 t
->answer_errno
= error
;
472 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
476 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
480 dns_transaction_close_connection(t
);
482 if (dns_packet_validate_reply(p
) <= 0) {
483 log_debug("Invalid TCP reply packet.");
484 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
488 dns_scope_check_conflicts(t
->scope
, p
);
491 dns_transaction_process_reply(t
, p
);
494 /* If the response wasn't useful, then complete the transition
495 * now. After all, we are the worst feature set now with TCP
496 * sockets, and there's really no point in retrying. */
497 if (t
->state
== DNS_TRANSACTION_PENDING
)
498 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
500 dns_transaction_gc(t
);
505 static int on_stream_complete(DnsStream
*s
, int error
) {
508 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
509 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
511 if (s
->transactions
) {
515 dns_server_packet_lost(t
->server
, IPPROTO_TCP
, t
->current_feature_level
);
520 DnsTransaction
*t
, *n
;
522 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
523 on_transaction_stream_error(t
, error
);
529 static int on_stream_packet(DnsStream
*s
) {
530 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
535 /* Take ownership of packet to be able to receive new packets */
536 p
= dns_stream_take_read_packet(s
);
539 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
541 return dns_transaction_on_stream_packet(t
, p
);
543 /* Ignore incorrect transaction id as an old transaction can have been canceled. */
544 log_debug("Received unexpected TCP reply packet with id %" PRIu16
", ignoring.", t
->id
);
548 static uint16_t dns_port_for_feature_level(DnsServerFeatureLevel level
) {
549 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(level
) ? 853 : 53;
552 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
553 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
554 _cleanup_close_
int fd
= -1;
555 union sockaddr_union sa
;
561 dns_transaction_close_connection(t
);
563 switch (t
->scope
->protocol
) {
565 case DNS_PROTOCOL_DNS
:
566 r
= dns_transaction_pick_server(t
);
570 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
573 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
577 if (t
->server
->stream
&& (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) == t
->server
->stream
->encrypted
))
578 s
= dns_stream_ref(t
->server
->stream
);
580 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, dns_port_for_feature_level(t
->current_feature_level
), &sa
);
582 type
= DNS_STREAM_LOOKUP
;
585 case DNS_PROTOCOL_LLMNR
:
586 /* When we already received a reply to this (but it was truncated), send to its sender address */
588 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
, &sa
);
590 union in_addr_union address
;
591 int family
= AF_UNSPEC
;
593 /* Otherwise, try to talk to the owner of a
594 * the IP address, in case this is a reverse
597 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
602 if (family
!= t
->scope
->family
)
605 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
, &sa
);
608 type
= DNS_STREAM_LLMNR_SEND
;
612 return -EAFNOSUPPORT
;
619 r
= dns_stream_new(t
->scope
->manager
, &s
, type
, t
->scope
->protocol
, fd
, &sa
);
625 #if ENABLE_DNS_OVER_TLS
626 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
&&
627 DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
)) {
630 r
= dnstls_stream_connect_tls(s
, t
->server
);
637 dns_server_unref_stream(t
->server
);
638 s
->server
= dns_server_ref(t
->server
);
639 t
->server
->stream
= dns_stream_ref(s
);
642 s
->complete
= on_stream_complete
;
643 s
->on_packet
= on_stream_packet
;
645 /* The interface index is difficult to determine if we are
646 * connecting to the local host, hence fill this in right away
647 * instead of determining it from the socket */
648 s
->ifindex
= dns_scope_ifindex(t
->scope
);
651 t
->stream
= TAKE_PTR(s
);
652 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
654 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
656 dns_transaction_close_connection(t
);
660 dns_transaction_reset_answer(t
);
662 t
->tried_stream
= true;
667 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
670 /* For mDNS we cache whenever we get the packet, rather than
671 * in each transaction. */
672 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
675 /* Caching disabled? */
676 if (!t
->scope
->manager
->enable_cache
)
679 /* We never cache if this packet is from the local host, under
680 * the assumption that a locally running DNS server would
681 * cache this anyway, and probably knows better when to flush
682 * the cache then we could. */
683 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
686 dns_cache_put(&t
->scope
->cache
,
690 t
->answer_authenticated
,
694 &t
->received
->sender
);
697 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
703 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
704 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
710 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
716 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
717 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
719 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
723 case DNS_TRANSACTION_NULL
:
724 case DNS_TRANSACTION_PENDING
:
725 case DNS_TRANSACTION_VALIDATING
:
729 case DNS_TRANSACTION_RCODE_FAILURE
:
730 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
731 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
735 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
736 * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
737 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
738 * RRs to make unsigned proofs. */
740 case DNS_TRANSACTION_SUCCESS
:
744 case DNS_TRANSACTION_DNSSEC_FAILED
:
745 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
746 * validationr result */
748 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
749 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
750 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
754 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
759 /* All is ready, we can go and validate */
763 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
764 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
768 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
773 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
774 r
= dns_transaction_dnssec_ready(t
);
777 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
780 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
781 * restart the lookup immediately. */
782 r
= dns_transaction_maybe_restart(t
);
785 if (r
> 0) /* Transaction got restarted... */
788 /* All our auxiliary DNSSEC transactions are complete now. Try
789 * to validate our RRset now. */
790 r
= dns_transaction_validate_dnssec(t
);
792 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
798 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
799 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
801 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
804 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
805 /* We tried fewer servers on this transaction than we know, let's try another one then */
806 dns_transaction_retry(t
, true);
810 /* OK, let's give up, apparently all servers we tried didn't work. */
811 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
815 if (!IN_SET(t
->answer_dnssec_result
,
816 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
817 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
818 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
819 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
820 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
824 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
825 dns_server_warn_downgrade(t
->server
);
827 dns_transaction_cache_answer(t
);
829 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
830 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
832 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
837 t
->answer_errno
= -r
;
838 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
841 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
846 /* Checks whether the answer is positive, i.e. either a direct
847 * answer to the question, or a CNAME/DNAME for it */
849 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
853 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
860 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
865 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
866 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
867 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
868 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
869 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
870 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
871 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
872 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
873 * incomplete CNAME/DNAME chain.
875 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
876 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
879 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
882 r
= dns_transaction_has_positive_answer(t
, NULL
);
886 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
890 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
897 assert(t
->scope
->manager
);
899 if (t
->state
!= DNS_TRANSACTION_PENDING
)
902 /* Note that this call might invalidate the query. Callers
903 * should hence not attempt to access the query or transaction
904 * after calling this function. */
906 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
907 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
909 switch (t
->scope
->protocol
) {
911 case DNS_PROTOCOL_LLMNR
:
912 /* For LLMNR we will not accept any packets from other interfaces */
914 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
917 if (p
->family
!= t
->scope
->family
)
920 /* Tentative packets are not full responses but still
921 * useful for identifying uniqueness conflicts during
923 if (DNS_PACKET_LLMNR_T(p
)) {
924 dns_transaction_tentative(t
, p
);
930 case DNS_PROTOCOL_MDNS
:
931 /* For mDNS we will not accept any packets from other interfaces */
933 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
936 if (p
->family
!= t
->scope
->family
)
941 case DNS_PROTOCOL_DNS
:
942 /* Note that we do not need to verify the
943 * addresses/port numbers of incoming traffic, as we
944 * invoked connect() on our UDP socket in which case
945 * the kernel already does the needed verification for
950 assert_not_reached("Invalid DNS protocol.");
953 if (t
->received
!= p
) {
954 dns_packet_unref(t
->received
);
955 t
->received
= dns_packet_ref(p
);
958 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
960 if (p
->ipproto
== IPPROTO_TCP
) {
961 if (DNS_PACKET_TC(p
)) {
962 /* Truncated via TCP? Somebody must be fucking with us */
963 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
967 if (DNS_PACKET_ID(p
) != t
->id
) {
968 /* Not the reply to our query? Somebody must be fucking with us */
969 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
974 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
976 switch (t
->scope
->protocol
) {
978 case DNS_PROTOCOL_DNS
:
981 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
983 /* Request failed, immediately try again with reduced features */
985 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
987 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
988 * this transaction anymore, but let's see if it might make sense to send the request
989 * to a different DNS server instead. If not let's process the response, and accept the
990 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
991 * packet loss, but is not going to give us better rcodes should we actually have
992 * managed to get them already at UDP level. */
994 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
995 /* We tried fewer servers on this transaction than we know, let's try another one then */
996 dns_transaction_retry(t
, true);
1000 /* Give up, accept the rcode */
1001 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1005 /* Reduce this feature level by one and try again. */
1006 switch (t
->current_feature_level
) {
1007 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1008 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1010 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1011 /* Skip plain TLS when TLS is not supported */
1012 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1015 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1018 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1019 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1020 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1022 dns_transaction_retry(t
, false /* use the same server */);
1026 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1027 /* This server refused our request? If so, try again, use a different server */
1028 log_debug("Server returned REFUSED, switching servers, and retrying.");
1029 dns_transaction_retry(t
, true /* pick a new server */);
1033 if (DNS_PACKET_TC(p
))
1034 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1038 case DNS_PROTOCOL_LLMNR
:
1039 case DNS_PROTOCOL_MDNS
:
1040 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1044 assert_not_reached("Invalid DNS protocol.");
1047 if (DNS_PACKET_TC(p
)) {
1049 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1050 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1051 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1055 log_debug("Reply truncated, retrying via TCP.");
1057 /* Response was truncated, let's try again with good old TCP */
1058 r
= dns_transaction_emit_tcp(t
);
1060 /* No servers found? Damn! */
1061 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1064 if (r
== -EOPNOTSUPP
) {
1065 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1066 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1070 /* On LLMNR, if we cannot connect to the host,
1071 * we immediately give up */
1072 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1075 /* On DNS, couldn't send? Try immediately again, with a new server */
1076 dns_transaction_retry(t
, true);
1082 /* After the superficial checks, actually parse the message. */
1083 r
= dns_packet_extract(p
);
1085 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1090 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1091 * rcode and subsequently downgraded the protocol */
1093 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1094 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1095 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1097 /* Report that the OPT RR was missing */
1099 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1101 /* Report that we successfully received a packet */
1102 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1105 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1106 r
= dns_transaction_maybe_restart(t
);
1109 if (r
> 0) /* Transaction got restarted... */
1112 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1114 /* When dealing with protocols other than mDNS only consider responses with
1115 * equivalent query section to the request. For mDNS this check doesn't make
1116 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1117 * contain any questions in the Question Section". */
1118 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1119 r
= dns_packet_is_reply_for(p
, t
->key
);
1123 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1128 /* Install the answer as answer to the transaction */
1129 dns_answer_unref(t
->answer
);
1130 t
->answer
= dns_answer_ref(p
->answer
);
1131 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1132 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1133 t
->answer_authenticated
= false;
1135 r
= dns_transaction_fix_rcode(t
);
1139 /* Block GC while starting requests for additional DNSSEC RRs */
1141 r
= dns_transaction_request_dnssec_keys(t
);
1144 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1145 if (!dns_transaction_gc(t
))
1148 /* Requesting additional keys might have resulted in
1149 * this transaction to fail, since the auxiliary
1150 * request failed for some reason. If so, we are not
1151 * in pending state anymore, and we should exit
1153 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1158 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1159 t
->state
= DNS_TRANSACTION_VALIDATING
;
1160 dns_transaction_close_connection(t
);
1161 dns_transaction_stop_timeout(t
);
1166 dns_transaction_process_dnssec(t
);
1170 t
->answer_errno
= -r
;
1171 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1174 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1175 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1176 DnsTransaction
*t
= userdata
;
1182 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1183 if (ERRNO_IS_DISCONNECT(-r
)) {
1186 /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next
1187 * recvmsg(). Treat this like a lost packet. */
1189 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1190 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1191 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1193 dns_transaction_retry(t
, true);
1197 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1198 t
->answer_errno
= -r
;
1202 r
= dns_packet_validate_reply(p
);
1204 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1208 log_debug("Received inappropriate DNS packet as response, ignoring.");
1212 if (DNS_PACKET_ID(p
) != t
->id
) {
1213 log_debug("Received packet with incorrect transaction ID, ignoring.");
1217 dns_transaction_process_reply(t
, p
);
1221 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1226 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1228 r
= dns_transaction_pick_server(t
);
1232 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1233 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1235 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1238 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1241 dns_transaction_close_connection(t
);
1243 fd
= dns_scope_socket_udp(t
->scope
, t
->server
, 53);
1247 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1253 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1257 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1261 dns_transaction_close_connection(t
);
1263 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1267 dns_transaction_reset_answer(t
);
1272 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1273 DnsTransaction
*t
= userdata
;
1278 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1279 /* Timeout reached? Increase the timeout for the server used */
1280 switch (t
->scope
->protocol
) {
1282 case DNS_PROTOCOL_DNS
:
1284 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1287 case DNS_PROTOCOL_LLMNR
:
1288 case DNS_PROTOCOL_MDNS
:
1289 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1293 assert_not_reached("Invalid DNS protocol.");
1296 if (t
->initial_jitter_scheduled
)
1297 t
->initial_jitter_elapsed
= true;
1300 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1302 dns_transaction_retry(t
, true);
1306 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1310 switch (t
->scope
->protocol
) {
1312 case DNS_PROTOCOL_DNS
:
1314 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1315 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1318 return TRANSACTION_TCP_TIMEOUT_USEC
;
1320 return DNS_TIMEOUT_USEC
;
1322 case DNS_PROTOCOL_MDNS
:
1323 assert(t
->n_attempts
> 0);
1325 return MDNS_PROBING_INTERVAL_USEC
;
1327 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1329 case DNS_PROTOCOL_LLMNR
:
1330 return t
->scope
->resend_timeout
;
1333 assert_not_reached("Invalid DNS protocol.");
1337 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1342 dns_transaction_stop_timeout(t
);
1344 if (!dns_scope_network_good(t
->scope
)) {
1345 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1349 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1350 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1354 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1355 /* If we already tried via a stream, then we don't
1356 * retry on LLMNR. See RFC 4795, Section 2.7. */
1357 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1364 dns_transaction_reset_answer(t
);
1365 dns_transaction_flush_dnssec_transactions(t
);
1367 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1368 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1369 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1373 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1374 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1375 t
->answer_authenticated
= true;
1376 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1380 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1381 t
->key
->type
== DNS_TYPE_DS
) {
1383 /* Hmm, this is a request for the root DS? A
1384 * DS RR doesn't exist in the root zone, and
1385 * if our trust anchor didn't know it either,
1386 * this means we cannot do any DNSSEC logic
1389 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1390 /* We are in downgrade mode. In this
1391 * case, synthesize an unsigned empty
1392 * response, so that the any lookup
1393 * depending on this one can continue
1394 * assuming there was no DS, and hence
1395 * the root zone was unsigned. */
1397 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1398 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1399 t
->answer_authenticated
= false;
1400 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1402 /* If we are not in downgrade mode,
1403 * then fail the lookup, because we
1404 * cannot reasonably answer it. There
1405 * might be DS RRs, but we don't know
1406 * them, and the DNS server won't tell
1407 * them to us (and even if it would,
1408 * we couldn't validate and trust them. */
1409 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1415 /* Check the zone, but only if this transaction is not used
1416 * for probing or verifying a zone item. */
1417 if (set_isempty(t
->notify_zone_items
)) {
1419 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1423 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1424 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1425 t
->answer_authenticated
= true;
1426 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1431 /* Check the cache, but only if this transaction is not used
1432 * for probing or verifying a zone item. */
1433 if (set_isempty(t
->notify_zone_items
)) {
1435 /* Before trying the cache, let's make sure we figured out a
1436 * server to use. Should this cause a change of server this
1437 * might flush the cache. */
1438 (void) dns_scope_get_dns_server(t
->scope
);
1440 /* Let's then prune all outdated entries */
1441 dns_cache_prune(&t
->scope
->cache
);
1443 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1447 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1448 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1449 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1451 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1459 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1461 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1462 bool add_known_answers
= false;
1463 DnsTransaction
*other
;
1465 DnsResourceKey
*tkey
;
1466 _cleanup_set_free_ Set
*keys
= NULL
;
1468 unsigned nscount
= 0;
1473 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1475 /* Discard any previously prepared packet, so we can start over and coalesce again */
1476 t
->sent
= dns_packet_unref(t
->sent
);
1478 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1482 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1488 if (dns_key_is_shared(t
->key
))
1489 add_known_answers
= true;
1491 if (t
->key
->type
== DNS_TYPE_ANY
) {
1492 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1496 r
= set_put(keys
, t
->key
);
1502 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1503 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1504 * in our current scope, and see whether their timing contraints allow them to be sent.
1507 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1509 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1511 /* Skip ourselves */
1515 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1518 if (other
->next_attempt_after
> ts
)
1521 if (qdcount
>= UINT16_MAX
)
1524 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1527 * If we can't stuff more questions into the packet, just give up.
1528 * One of the 'other' transactions will fire later and take care of the rest.
1536 r
= dns_transaction_prepare(other
, ts
);
1540 ts
+= transaction_get_resend_timeout(other
);
1542 r
= sd_event_add_time(
1543 other
->scope
->manager
->event
,
1544 &other
->timeout_event_source
,
1545 clock_boottime_or_monotonic(),
1547 on_transaction_timeout
, other
);
1551 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1553 other
->state
= DNS_TRANSACTION_PENDING
;
1554 other
->next_attempt_after
= ts
;
1558 if (dns_key_is_shared(other
->key
))
1559 add_known_answers
= true;
1561 if (other
->key
->type
== DNS_TYPE_ANY
) {
1562 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1566 r
= set_put(keys
, other
->key
);
1572 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1574 /* Append known answer section if we're asking for any shared record */
1575 if (add_known_answers
) {
1576 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1581 SET_FOREACH(tkey
, keys
, i
) {
1582 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1585 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1589 r
= dns_packet_append_answer(p
, answer
);
1593 nscount
+= dns_answer_size(answer
);
1595 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1597 t
->sent
= TAKE_PTR(p
);
1602 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1603 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1608 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1609 return dns_transaction_make_packet_mdns(t
);
1614 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1618 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1622 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1623 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1625 t
->sent
= TAKE_PTR(p
);
1630 int dns_transaction_go(DnsTransaction
*t
) {
1633 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1637 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1640 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1642 r
= dns_transaction_prepare(t
, ts
);
1646 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1648 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1649 dns_protocol_to_string(t
->scope
->protocol
),
1650 t
->scope
->link
? t
->scope
->link
->name
: "*",
1651 af_to_name_short(t
->scope
->family
));
1653 if (!t
->initial_jitter_scheduled
&&
1654 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1655 usec_t jitter
, accuracy
;
1657 /* RFC 4795 Section 2.7 suggests all queries should be
1658 * delayed by a random time from 0 to JITTER_INTERVAL. */
1660 t
->initial_jitter_scheduled
= true;
1662 random_bytes(&jitter
, sizeof(jitter
));
1664 switch (t
->scope
->protocol
) {
1666 case DNS_PROTOCOL_LLMNR
:
1667 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1668 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1671 case DNS_PROTOCOL_MDNS
:
1672 jitter
%= MDNS_JITTER_RANGE_USEC
;
1673 jitter
+= MDNS_JITTER_MIN_USEC
;
1674 accuracy
= MDNS_JITTER_RANGE_USEC
;
1677 assert_not_reached("bad protocol");
1680 r
= sd_event_add_time(
1681 t
->scope
->manager
->event
,
1682 &t
->timeout_event_source
,
1683 clock_boottime_or_monotonic(),
1684 ts
+ jitter
, accuracy
,
1685 on_transaction_timeout
, t
);
1689 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1692 t
->next_attempt_after
= ts
;
1693 t
->state
= DNS_TRANSACTION_PENDING
;
1695 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1699 /* Otherwise, we need to ask the network */
1700 r
= dns_transaction_make_packet(t
);
1704 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1705 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1706 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1708 /* RFC 4795, Section 2.4. says reverse lookups shall
1709 * always be made via TCP on LLMNR */
1710 r
= dns_transaction_emit_tcp(t
);
1712 /* Try via UDP, and if that fails due to large size or lack of
1713 * support try via TCP */
1714 r
= dns_transaction_emit_udp(t
);
1716 log_debug("Sending query via TCP since it is too large.");
1717 else if (r
== -EAGAIN
)
1718 log_debug("Sending query via TCP since UDP isn't supported.");
1719 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1720 r
= dns_transaction_emit_tcp(t
);
1724 /* No servers to send this to? */
1725 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1728 if (r
== -EOPNOTSUPP
) {
1729 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1730 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1733 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1734 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1735 * answer this request with this protocol. */
1736 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1740 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1743 /* Couldn't send? Try immediately again, with a new server */
1744 dns_scope_next_dns_server(t
->scope
);
1746 return dns_transaction_go(t
);
1749 ts
+= transaction_get_resend_timeout(t
);
1751 r
= sd_event_add_time(
1752 t
->scope
->manager
->event
,
1753 &t
->timeout_event_source
,
1754 clock_boottime_or_monotonic(),
1756 on_transaction_timeout
, t
);
1760 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1762 t
->state
= DNS_TRANSACTION_PENDING
;
1763 t
->next_attempt_after
= ts
;
1768 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1776 /* Try to find cyclic dependencies between transaction objects */
1781 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1782 r
= dns_transaction_find_cyclic(t
, n
);
1790 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1791 DnsTransaction
*aux
;
1798 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1800 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1804 if (set_contains(t
->dnssec_transactions
, aux
)) {
1809 r
= dns_transaction_find_cyclic(t
, aux
);
1813 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1815 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1816 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1818 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1820 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1824 r
= set_ensure_allocated(&t
->dnssec_transactions
, NULL
);
1828 r
= set_ensure_allocated(&aux
->notify_transactions
, NULL
);
1832 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1836 r
= set_put(t
->dnssec_transactions
, aux
);
1840 r
= set_put(aux
->notify_transactions
, t
);
1842 (void) set_remove(t
->dnssec_transactions
, aux
);
1850 dns_transaction_gc(aux
);
1854 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1855 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1856 DnsTransaction
*aux
;
1862 /* Try to get the data from the trust anchor */
1863 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1867 r
= dns_answer_extend(&t
->validated_keys
, a
);
1874 /* This didn't work, ask for it via the network/cache then. */
1875 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1876 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1881 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1882 r
= dns_transaction_go(aux
);
1890 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1895 /* Check whether the specified name is in the NTA
1896 * database, either in the global one, or the link-local
1899 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1903 if (!t
->scope
->link
)
1906 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1909 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1914 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1915 * RRs to prove it */
1917 r
= dns_transaction_has_positive_answer(t
, NULL
);
1923 /* Is this key explicitly listed as a negative trust anchor?
1924 * If so, it's nothing we need to care about */
1925 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1931 /* The answer does not contain any RRs that match to the
1932 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1933 * included. If not, the answer is unsigned. */
1935 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1944 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1950 /* Check if the specified RR is the "primary" response,
1951 * i.e. either matches the question precisely or is a
1952 * CNAME/DNAME for it. */
1954 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1958 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1961 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1964 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1965 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1967 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1970 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1971 * be supported, hence return true. */
1975 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1976 * the server is known to support currently, as the transaction feature level might be lower than what the
1977 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1978 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1980 return dns_server_dnssec_supported(t
->server
);
1983 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1989 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1991 if (!dns_transaction_dnssec_supported(t
))
1994 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1995 if (!dns_transaction_dnssec_supported(dt
))
2001 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
2002 DnsResourceRecord
*rr
;
2009 * Retrieve all auxiliary RRs for the answer we got, so that
2010 * we can verify signatures or prove that RRs are rightfully
2011 * unsigned. Specifically:
2013 * - For RRSIG we get the matching DNSKEY
2014 * - For DNSKEY we get the matching DS
2015 * - For unsigned SOA/NS we get the matching DS
2016 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2017 * - For other unsigned RRs we get the matching SOA RR
2018 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2019 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2020 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2023 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2025 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2026 return 0; /* We only need to validate stuff from the network */
2027 if (!dns_transaction_dnssec_supported(t
))
2028 return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */
2030 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2032 if (dns_type_is_pseudo(rr
->key
->type
))
2035 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2036 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2042 switch (rr
->key
->type
) {
2044 case DNS_TYPE_RRSIG
: {
2045 /* For each RRSIG we request the matching DNSKEY */
2046 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2048 /* If this RRSIG is about a DNSKEY RR and the
2049 * signer is the same as the owner, then we
2050 * already have the DNSKEY, and we don't have
2051 * to look for more. */
2052 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2053 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2060 /* If the signer is not a parent of our
2061 * original query, then this is about an
2062 * auxiliary RRset, but not anything we asked
2063 * for. In this case we aren't interested,
2064 * because we don't want to request additional
2065 * RRs for stuff we didn't really ask for, and
2066 * also to avoid request loops, where
2067 * additional RRs from one transaction result
2068 * in another transaction whose additonal RRs
2069 * point back to the original transaction, and
2071 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2077 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2081 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2082 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2083 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2089 case DNS_TYPE_DNSKEY
: {
2090 /* For each DNSKEY we request the matching DS */
2091 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2093 /* If the DNSKEY we are looking at is not for
2094 * zone we are interested in, nor any of its
2095 * parents, we aren't interested, and don't
2096 * request it. After all, we don't want to end
2097 * up in request loops, and want to keep
2098 * additional traffic down. */
2100 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2106 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2110 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2111 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2112 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2121 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2123 /* For an unsigned SOA or NS, try to acquire
2124 * the matching DS RR, as we are at a zone cut
2125 * then, and whether a DS exists tells us
2126 * whether the zone is signed. Do so only if
2127 * this RR matches our original question,
2130 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2134 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2135 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2136 * If so, we need to validate it, too. */
2138 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2141 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2145 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2146 * what we are looking for, otherwise there's no value in it for us. */
2147 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2154 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2160 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2164 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2165 t
->id
, dns_resource_key_name(rr
->key
));
2166 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2174 case DNS_TYPE_CNAME
:
2175 case DNS_TYPE_DNAME
: {
2176 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2179 /* CNAMEs and DNAMEs cannot be located at a
2180 * zone apex, hence ask for the parent SOA for
2181 * unsigned CNAME/DNAME RRs, maybe that's the
2182 * apex. But do all that only if this is
2183 * actually a response to our original
2186 * Similar for DS RRs, which are signed when
2187 * the parent SOA is signed. */
2189 r
= dns_transaction_is_primary_response(t
, rr
);
2195 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2201 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2207 name
= dns_resource_key_name(rr
->key
);
2208 r
= dns_name_parent(&name
);
2214 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2218 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2219 t
->id
, dns_resource_key_name(rr
->key
));
2220 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2228 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2230 /* For other unsigned RRsets (including
2231 * NSEC/NSEC3!), look for proof the zone is
2232 * unsigned, by requesting the SOA RR of the
2233 * zone. However, do so only if they are
2234 * directly relevant to our original
2237 r
= dns_transaction_is_primary_response(t
, rr
);
2243 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2249 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2253 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2254 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2255 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2262 /* Above, we requested everything necessary to validate what
2263 * we got. Now, let's request what we need to validate what we
2266 r
= dns_transaction_has_unsigned_negative_answer(t
);
2273 name
= dns_resource_key_name(t
->key
);
2275 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2276 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2277 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2278 * though they have further children. If this was a DS request, then it's signed when the parent zone
2279 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2280 * to see if that is signed. */
2282 if (t
->key
->type
== DNS_TYPE_DS
) {
2283 r
= dns_name_parent(&name
);
2285 type
= DNS_TYPE_SOA
;
2286 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2287 name
, t
->id
, dns_resource_key_name(t
->key
));
2291 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2294 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2298 type
= DNS_TYPE_SOA
;
2299 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2304 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2306 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2310 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2316 return dns_transaction_dnssec_is_live(t
);
2319 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2323 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2324 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2325 the state is VALIDATING however, we should check if we are complete now. */
2327 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2328 dns_transaction_process_dnssec(t
);
2331 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2332 DnsResourceRecord
*rr
;
2337 /* Add all DNSKEY RRs from the answer that are validated by DS
2338 * RRs from the list of validated keys to the list of
2339 * validated keys. */
2341 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2343 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2349 /* If so, the DNSKEY is validated too. */
2350 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2358 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2364 /* Checks if the RR we are looking for must be signed with an
2365 * RRSIG. This is used for positive responses. */
2367 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2370 if (dns_type_is_pseudo(rr
->key
->type
))
2373 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2379 switch (rr
->key
->type
) {
2381 case DNS_TYPE_RRSIG
:
2382 /* RRSIGs are the signatures themselves, they need no signing. */
2390 /* For SOA or NS RRs we look for a matching DS transaction */
2392 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2394 if (dt
->key
->class != rr
->key
->class)
2396 if (dt
->key
->type
!= DNS_TYPE_DS
)
2399 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2405 /* We found a DS transactions for the SOA/NS
2406 * RRs we are looking at. If it discovered signed DS
2407 * RRs, then we need to be signed, too. */
2409 if (!dt
->answer_authenticated
)
2412 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2415 /* We found nothing that proves this is safe to leave
2416 * this unauthenticated, hence ask inist on
2417 * authentication. */
2422 case DNS_TYPE_CNAME
:
2423 case DNS_TYPE_DNAME
: {
2424 const char *parent
= NULL
;
2429 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2431 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2434 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2436 if (dt
->key
->class != rr
->key
->class)
2438 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2442 parent
= dns_resource_key_name(rr
->key
);
2443 r
= dns_name_parent(&parent
);
2447 if (rr
->key
->type
== DNS_TYPE_DS
)
2450 /* A CNAME/DNAME without a parent? That's sooo weird. */
2451 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2452 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2456 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2462 return t
->answer_authenticated
;
2472 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2474 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2476 if (dt
->key
->class != rr
->key
->class)
2478 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2481 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2487 /* We found the transaction that was supposed to find
2488 * the SOA RR for us. It was successful, but found no
2489 * RR for us. This means we are not at a zone cut. In
2490 * this case, we require authentication if the SOA
2491 * lookup was authenticated too. */
2492 return t
->answer_authenticated
;
2499 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2505 /* If DNSSEC downgrade mode is on, checks whether the
2506 * specified RR is one level below a TLD we have proven not to
2507 * exist. In such a case we assume that this is a private
2508 * domain, and permit it.
2510 * This detects cases like the Fritz!Box router networks. Each
2511 * Fritz!Box router serves a private "fritz.box" zone, in the
2512 * non-existing TLD "box". Requests for the "fritz.box" domain
2513 * are served by the router itself, while requests for the
2514 * "box" domain will result in NXDOMAIN.
2516 * Note that this logic is unable to detect cases where a
2517 * router serves a private DNS zone directly under
2518 * non-existing TLD. In such a case we cannot detect whether
2519 * the TLD is supposed to exist or not, as all requests we
2520 * make for it will be answered by the router's zone, and not
2521 * by the root zone. */
2525 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2526 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2528 tld
= dns_resource_key_name(key
);
2529 r
= dns_name_parent(&tld
);
2533 return false; /* Already the root domain */
2535 if (!dns_name_is_single_label(tld
))
2538 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2540 if (dt
->key
->class != key
->class)
2543 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2549 /* We found an auxiliary lookup we did for the TLD. If
2550 * that returned with NXDOMAIN, we know the TLD didn't
2551 * exist, and hence this might be a private zone. */
2553 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2559 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2560 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2569 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2570 * this negative reply */
2572 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2575 if (dns_type_is_pseudo(t
->key
->type
))
2578 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2584 r
= dns_transaction_in_private_tld(t
, t
->key
);
2588 /* The lookup is from a TLD that is proven not to
2589 * exist, and we are in downgrade mode, hence ignore
2590 * that fact that we didn't get any NSEC RRs. */
2592 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2593 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2597 name
= dns_resource_key_name(t
->key
);
2599 if (t
->key
->type
== DNS_TYPE_DS
) {
2601 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2602 * hence check the parent SOA in this case. */
2604 r
= dns_name_parent(&name
);
2610 type
= DNS_TYPE_SOA
;
2612 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2613 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2616 /* For all other negative replies, check for the SOA lookup */
2617 type
= DNS_TYPE_SOA
;
2619 /* For all other RRs we check the SOA on the same level to see
2620 * if it's signed. */
2622 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2624 if (dt
->key
->class != t
->key
->class)
2626 if (dt
->key
->type
!= type
)
2629 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2635 return dt
->answer_authenticated
;
2638 /* If in doubt, require NSEC/NSEC3 */
2642 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2643 DnsResourceRecord
*rrsig
;
2647 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2648 * the specified RRset is authenticated (i.e. has a matching
2651 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2657 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2661 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2667 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2669 if (dt
->key
->class != rr
->key
->class)
2672 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2674 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2680 /* OK, we found an auxiliary DNSKEY
2681 * lookup. If that lookup is
2682 * authenticated, report this. */
2684 if (dt
->answer_authenticated
)
2689 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2691 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2697 /* OK, we found an auxiliary DS
2698 * lookup. If that lookup is
2699 * authenticated and non-zero, we
2702 if (!dt
->answer_authenticated
)
2705 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2710 return found
? false : -ENXIO
;
2713 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2717 /* We know that the root domain is signed, hence if it appears
2718 * not to be signed, there's a problem with the DNS server */
2720 return rr
->key
->class == DNS_CLASS_IN
&&
2721 dns_name_is_root(dns_resource_key_name(rr
->key
));
2724 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2725 DnsResourceRecord
*rr
;
2730 /* Maybe warn the user that we encountered a revoked DNSKEY
2731 * for a key from our trust anchor. Note that we don't care
2732 * whether the DNSKEY can be authenticated or not. It's
2733 * sufficient if it is self-signed. */
2735 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2736 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2744 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2750 /* Removes all DNSKEY/DS objects from t->validated_keys that
2751 * our trust anchors database considers revoked. */
2754 DnsResourceRecord
*rr
;
2758 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2759 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2763 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2777 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2784 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2786 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2788 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2791 if (!dt
->answer_authenticated
)
2794 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2803 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2804 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2805 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2808 static int dnssec_validate_records(
2812 DnsAnswer
**validated
) {
2814 DnsResourceRecord
*rr
;
2817 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2819 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2820 DnsResourceRecord
*rrsig
= NULL
;
2821 DnssecResult result
;
2823 switch (rr
->key
->type
) {
2824 case DNS_TYPE_RRSIG
:
2827 case DNS_TYPE_DNSKEY
:
2828 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2829 if (phase
== DNSSEC_PHASE_NSEC
)
2834 case DNS_TYPE_NSEC3
:
2837 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2838 if (phase
== DNSSEC_PHASE_DNSKEY
)
2843 /* We validate all other RRs only in the ALL phases */
2844 if (phase
!= DNSSEC_PHASE_ALL
)
2848 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2852 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2854 if (result
== DNSSEC_VALIDATED
) {
2856 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2857 /* If we just validated a DNSKEY RRset, then let's add these keys to
2858 * the set of validated keys for this transaction. */
2860 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2864 /* Some of the DNSKEYs we just added might already have been revoked,
2865 * remove them again in that case. */
2866 r
= dns_transaction_invalidate_revoked_keys(t
);
2871 /* Add the validated RRset to the new list of validated
2872 * RRsets, and remove it from the unvalidated RRsets.
2873 * We mark the RRset as authenticated and cacheable. */
2874 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2878 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2880 /* Exit the loop, we dropped something from the answer, start from the beginning */
2884 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2885 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2886 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2887 if (phase
!= DNSSEC_PHASE_ALL
)
2890 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2891 bool authenticated
= false;
2894 /* This RRset validated, but as a wildcard. This means we need
2895 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2897 /* First step, determine the source of synthesis */
2898 r
= dns_resource_record_source(rrsig
, &source
);
2902 r
= dnssec_test_positive_wildcard(*validated
,
2903 dns_resource_key_name(rr
->key
),
2905 rrsig
->rrsig
.signer
,
2908 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2910 result
= DNSSEC_INVALID
;
2912 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2913 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2917 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2919 /* Exit the loop, we dropped something from the answer, start from the beginning */
2924 if (result
== DNSSEC_NO_SIGNATURE
) {
2925 r
= dns_transaction_requires_rrsig(t
, rr
);
2929 /* Data does not require signing. In that case, just copy it over,
2930 * but remember that this is by no means authenticated. */
2931 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2935 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2939 r
= dns_transaction_known_signed(t
, rr
);
2943 /* This is an RR we know has to be signed. If it isn't this means
2944 * the server is not attaching RRSIGs, hence complain. */
2946 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2948 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2950 /* Downgrading is OK? If so, just consider the information unsigned */
2952 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2956 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2960 /* Otherwise, fail */
2961 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2965 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2969 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2971 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2972 * mode, hence ignore the fact that this was not signed. */
2974 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2975 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2977 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2981 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2988 DNSSEC_SIGNATURE_EXPIRED
,
2989 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2991 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2992 if (r
< 0 && r
!= -ENXIO
)
2995 /* The DNSKEY transaction was not authenticated, this means there's
2996 * no DS for this, which means it's OK if no keys are found for this signature. */
2998 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
3002 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
3007 r
= dns_transaction_is_primary_response(t
, rr
);
3011 /* Look for a matching DNAME for this CNAME */
3012 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
3016 /* Also look among the stuff we already validated */
3017 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3025 DNSSEC_SIGNATURE_EXPIRED
,
3026 DNSSEC_NO_SIGNATURE
))
3027 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3028 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3029 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3031 /* This is a primary response to our question, and it failed validation.
3033 t
->answer_dnssec_result
= result
;
3037 /* This is a primary response, but we do have a DNAME RR
3038 * in the RR that can replay this CNAME, hence rely on
3039 * that, and we can remove the CNAME in favour of it. */
3042 /* This is just some auxiliary data. Just remove the RRset and continue. */
3043 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3047 /* We dropped something from the answer, start from the beginning. */
3051 return 2; /* Finito. */
3054 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3055 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3057 DnsAnswerFlags flags
;
3059 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3063 /* We have now collected all DS and DNSKEY RRs in
3064 * t->validated_keys, let's see which RRs we can now
3065 * authenticate with that. */
3067 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3070 /* Already validated */
3071 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3074 /* Our own stuff needs no validation */
3075 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3076 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3077 t
->answer_authenticated
= true;
3081 /* Cached stuff is not affected by validation. */
3082 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3085 if (!dns_transaction_dnssec_supported_full(t
)) {
3086 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3087 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3088 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3092 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3094 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3096 /* First, see if this response contains any revoked trust
3097 * anchors we care about */
3098 r
= dns_transaction_check_revoked_trust_anchors(t
);
3102 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3103 r
= dns_transaction_copy_validated(t
);
3107 /* Second, see if there are DNSKEYs we already know a
3108 * validated DS for. */
3109 r
= dns_transaction_validate_dnskey_by_ds(t
);
3113 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3114 * anchor says are revoked. After all we might have marked
3115 * some keys revoked above, but they might still be lingering
3116 * in our validated_keys list. */
3117 r
= dns_transaction_invalidate_revoked_keys(t
);
3121 phase
= DNSSEC_PHASE_DNSKEY
;
3123 bool have_nsec
= false;
3125 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3129 /* Try again as long as we managed to achieve something */
3133 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3134 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3135 phase
= DNSSEC_PHASE_NSEC
;
3139 if (phase
!= DNSSEC_PHASE_ALL
) {
3140 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3141 * Note that in this third phase we start to remove RRs we couldn't validate. */
3142 phase
= DNSSEC_PHASE_ALL
;
3150 dns_answer_unref(t
->answer
);
3151 t
->answer
= TAKE_PTR(validated
);
3153 /* At this point the answer only contains validated
3154 * RRsets. Now, let's see if it actually answers the question
3155 * we asked. If so, great! If it doesn't, then see if
3156 * NSEC/NSEC3 can prove this. */
3157 r
= dns_transaction_has_positive_answer(t
, &flags
);
3159 /* Yes, it answers the question! */
3161 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3162 /* The answer is fully authenticated, yay. */
3163 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3164 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3165 t
->answer_authenticated
= true;
3167 /* The answer is not fully authenticated. */
3168 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3169 t
->answer_authenticated
= false;
3172 } else if (r
== 0) {
3173 DnssecNsecResult nr
;
3174 bool authenticated
= false;
3176 /* Bummer! Let's check NSEC/NSEC3 */
3177 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3183 case DNSSEC_NSEC_NXDOMAIN
:
3184 /* NSEC proves the domain doesn't exist. Very good. */
3185 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3186 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3187 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3188 t
->answer_authenticated
= authenticated
;
3190 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3193 case DNSSEC_NSEC_NODATA
:
3194 /* NSEC proves that there's no data here, very good. */
3195 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3196 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3197 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3198 t
->answer_authenticated
= authenticated
;
3200 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3203 case DNSSEC_NSEC_OPTOUT
:
3204 /* NSEC3 says the data might not be signed */
3205 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3206 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3207 t
->answer_authenticated
= false;
3209 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3212 case DNSSEC_NSEC_NO_RR
:
3213 /* No NSEC data? Bummer! */
3215 r
= dns_transaction_requires_nsec(t
);
3219 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3220 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3222 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3223 t
->answer_authenticated
= false;
3224 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3229 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3230 /* We don't know the NSEC3 algorithm used? */
3231 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3232 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3235 case DNSSEC_NSEC_FOUND
:
3236 case DNSSEC_NSEC_CNAME
:
3237 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3238 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3239 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3243 assert_not_reached("Unexpected NSEC result.");
3250 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3251 [DNS_TRANSACTION_NULL
] = "null",
3252 [DNS_TRANSACTION_PENDING
] = "pending",
3253 [DNS_TRANSACTION_VALIDATING
] = "validating",
3254 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3255 [DNS_TRANSACTION_SUCCESS
] = "success",
3256 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3257 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3258 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3259 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3260 [DNS_TRANSACTION_ERRNO
] = "errno",
3261 [DNS_TRANSACTION_ABORTED
] = "aborted",
3262 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3263 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3264 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3265 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3266 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3268 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3270 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3271 [DNS_TRANSACTION_NETWORK
] = "network",
3272 [DNS_TRANSACTION_CACHE
] = "cache",
3273 [DNS_TRANSACTION_ZONE
] = "zone",
3274 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3276 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);