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
) {
506 _cleanup_(dns_stream_unrefp
) DnsStream
*p
= NULL
;
508 /* Do not let new transactions use this stream */
509 if (s
->server
&& s
->server
->stream
== s
)
510 p
= TAKE_PTR(s
->server
->stream
);
512 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
513 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
515 if (s
->transactions
) {
519 dns_server_packet_lost(t
->server
, IPPROTO_TCP
, t
->current_feature_level
);
524 DnsTransaction
*t
, *n
;
526 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
527 on_transaction_stream_error(t
, error
);
533 static int on_stream_packet(DnsStream
*s
) {
534 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
539 /* Take ownership of packet to be able to receive new packets */
540 p
= dns_stream_take_read_packet(s
);
543 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
545 return dns_transaction_on_stream_packet(t
, p
);
547 /* Ignore incorrect transaction id as transaction can have been canceled */
548 if (dns_packet_validate_reply(p
) <= 0) {
549 log_debug("Invalid TCP reply packet.");
550 on_stream_complete(s
, 0);
556 static uint16_t dns_port_for_feature_level(DnsServerFeatureLevel level
) {
557 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(level
) ? 853 : 53;
560 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
561 _cleanup_close_
int fd
= -1;
562 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
563 union sockaddr_union sa
;
568 dns_transaction_close_connection(t
);
570 switch (t
->scope
->protocol
) {
572 case DNS_PROTOCOL_DNS
:
573 r
= dns_transaction_pick_server(t
);
577 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
580 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
584 if (t
->server
->stream
&& (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) == t
->server
->stream
->encrypted
))
585 s
= dns_stream_ref(t
->server
->stream
);
587 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, dns_port_for_feature_level(t
->current_feature_level
), &sa
);
591 case DNS_PROTOCOL_LLMNR
:
592 /* When we already received a reply to this (but it was truncated), send to its sender address */
594 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
, &sa
);
596 union in_addr_union address
;
597 int family
= AF_UNSPEC
;
599 /* Otherwise, try to talk to the owner of a
600 * the IP address, in case this is a reverse
603 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
608 if (family
!= t
->scope
->family
)
611 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
, &sa
);
617 return -EAFNOSUPPORT
;
624 r
= dns_stream_new(t
->scope
->manager
, &s
, t
->scope
->protocol
, fd
, &sa
);
630 #if ENABLE_DNS_OVER_TLS
631 if (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
)) {
633 r
= dnstls_stream_connect_tls(s
, t
->server
);
640 dns_stream_unref(t
->server
->stream
);
641 t
->server
->stream
= dns_stream_ref(s
);
642 s
->server
= dns_server_ref(t
->server
);
645 s
->complete
= on_stream_complete
;
646 s
->on_packet
= on_stream_packet
;
648 /* The interface index is difficult to determine if we are
649 * connecting to the local host, hence fill this in right away
650 * instead of determining it from the socket */
651 s
->ifindex
= dns_scope_ifindex(t
->scope
);
654 t
->stream
= TAKE_PTR(s
);
655 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
657 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
659 dns_transaction_close_connection(t
);
663 dns_transaction_reset_answer(t
);
665 t
->tried_stream
= true;
670 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
673 /* For mDNS we cache whenever we get the packet, rather than
674 * in each transaction. */
675 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
678 /* Caching disabled? */
679 if (!t
->scope
->manager
->enable_cache
)
682 /* We never cache if this packet is from the local host, under
683 * the assumption that a locally running DNS server would
684 * cache this anyway, and probably knows better when to flush
685 * the cache then we could. */
686 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
689 dns_cache_put(&t
->scope
->cache
,
693 t
->answer_authenticated
,
697 &t
->received
->sender
);
700 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
706 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
707 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
713 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
719 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
720 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
722 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
726 case DNS_TRANSACTION_NULL
:
727 case DNS_TRANSACTION_PENDING
:
728 case DNS_TRANSACTION_VALIDATING
:
732 case DNS_TRANSACTION_RCODE_FAILURE
:
733 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
734 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
738 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
739 * erronously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
740 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
741 * RRs to make unsigned proofs. */
743 case DNS_TRANSACTION_SUCCESS
:
747 case DNS_TRANSACTION_DNSSEC_FAILED
:
748 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
749 * validationr result */
751 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
752 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
753 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
757 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
762 /* All is ready, we can go and validate */
766 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
767 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
771 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
776 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
777 r
= dns_transaction_dnssec_ready(t
);
780 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
783 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
784 * restart the lookup immediately. */
785 r
= dns_transaction_maybe_restart(t
);
788 if (r
> 0) /* Transaction got restarted... */
791 /* All our auxiliary DNSSEC transactions are complete now. Try
792 * to validate our RRset now. */
793 r
= dns_transaction_validate_dnssec(t
);
795 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
801 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
802 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
804 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
807 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
808 /* We tried fewer servers on this transaction than we know, let's try another one then */
809 dns_transaction_retry(t
, true);
813 /* OK, let's give up, apparently all servers we tried didn't work. */
814 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
818 if (!IN_SET(t
->answer_dnssec_result
,
819 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
820 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
821 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
822 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
823 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
827 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
828 dns_server_warn_downgrade(t
->server
);
830 dns_transaction_cache_answer(t
);
832 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
833 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
835 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
840 t
->answer_errno
= -r
;
841 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
844 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
849 /* Checks whether the answer is positive, i.e. either a direct
850 * answer to the question, or a CNAME/DNAME for it */
852 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
856 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
863 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
868 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
869 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
870 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
871 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
872 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
873 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
874 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
875 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
876 * incomplete CNAME/DNAME chain.
878 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
879 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
882 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
885 r
= dns_transaction_has_positive_answer(t
, NULL
);
889 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
893 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
900 assert(t
->scope
->manager
);
902 if (t
->state
!= DNS_TRANSACTION_PENDING
)
905 /* Note that this call might invalidate the query. Callers
906 * should hence not attempt to access the query or transaction
907 * after calling this function. */
909 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
910 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
912 switch (t
->scope
->protocol
) {
914 case DNS_PROTOCOL_LLMNR
:
915 /* For LLMNR we will not accept any packets from other interfaces */
917 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
920 if (p
->family
!= t
->scope
->family
)
923 /* Tentative packets are not full responses but still
924 * useful for identifying uniqueness conflicts during
926 if (DNS_PACKET_LLMNR_T(p
)) {
927 dns_transaction_tentative(t
, p
);
933 case DNS_PROTOCOL_MDNS
:
934 /* For mDNS we will not accept any packets from other interfaces */
936 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
939 if (p
->family
!= t
->scope
->family
)
944 case DNS_PROTOCOL_DNS
:
945 /* Note that we do not need to verify the
946 * addresses/port numbers of incoming traffic, as we
947 * invoked connect() on our UDP socket in which case
948 * the kernel already does the needed verification for
953 assert_not_reached("Invalid DNS protocol.");
956 if (t
->received
!= p
) {
957 dns_packet_unref(t
->received
);
958 t
->received
= dns_packet_ref(p
);
961 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
963 if (p
->ipproto
== IPPROTO_TCP
) {
964 if (DNS_PACKET_TC(p
)) {
965 /* Truncated via TCP? Somebody must be fucking with us */
966 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
970 if (DNS_PACKET_ID(p
) != t
->id
) {
971 /* Not the reply to our query? Somebody must be fucking with us */
972 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
977 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
979 switch (t
->scope
->protocol
) {
981 case DNS_PROTOCOL_DNS
:
984 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
986 /* Request failed, immediately try again with reduced features */
988 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
990 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
991 * this transaction anymore, but let's see if it might make sense to send the request
992 * to a different DNS server instead. If not let's process the response, and accept the
993 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
994 * packet loss, but is not going to give us better rcodes should we actually have
995 * managed to get them already at UDP level. */
997 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
998 /* We tried fewer servers on this transaction than we know, let's try another one then */
999 dns_transaction_retry(t
, true);
1003 /* Give up, accept the rcode */
1004 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1008 /* Reduce this feature level by one and try again. */
1009 switch (t
->current_feature_level
) {
1010 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1011 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1013 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1014 /* Skip plain TLS when TLS is not supported */
1015 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1018 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1021 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1022 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1023 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1025 dns_transaction_retry(t
, false /* use the same server */);
1029 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1030 /* This server refused our request? If so, try again, use a different server */
1031 log_debug("Server returned REFUSED, switching servers, and retrying.");
1032 dns_transaction_retry(t
, true /* pick a new server */);
1036 if (DNS_PACKET_TC(p
))
1037 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1041 case DNS_PROTOCOL_LLMNR
:
1042 case DNS_PROTOCOL_MDNS
:
1043 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1047 assert_not_reached("Invalid DNS protocol.");
1050 if (DNS_PACKET_TC(p
)) {
1052 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1053 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1054 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1058 log_debug("Reply truncated, retrying via TCP.");
1060 /* Response was truncated, let's try again with good old TCP */
1061 r
= dns_transaction_emit_tcp(t
);
1063 /* No servers found? Damn! */
1064 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1067 if (r
== -EOPNOTSUPP
) {
1068 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1069 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1073 /* On LLMNR, if we cannot connect to the host,
1074 * we immediately give up */
1075 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1078 /* On DNS, couldn't send? Try immediately again, with a new server */
1079 dns_transaction_retry(t
, true);
1085 /* After the superficial checks, actually parse the message. */
1086 r
= dns_packet_extract(p
);
1088 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1093 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1094 * rcode and subsequently downgraded the protocol */
1096 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1097 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1098 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1100 /* Report that the OPT RR was missing */
1102 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1104 /* Report that we successfully received a packet */
1105 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1108 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1109 r
= dns_transaction_maybe_restart(t
);
1112 if (r
> 0) /* Transaction got restarted... */
1115 if (IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1117 /* When dealing with protocols other than mDNS only consider responses with
1118 * equivalent query section to the request. For mDNS this check doesn't make
1119 * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT
1120 * contain any questions in the Question Section". */
1121 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1122 r
= dns_packet_is_reply_for(p
, t
->key
);
1126 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1131 /* Install the answer as answer to the transaction */
1132 dns_answer_unref(t
->answer
);
1133 t
->answer
= dns_answer_ref(p
->answer
);
1134 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1135 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1136 t
->answer_authenticated
= false;
1138 r
= dns_transaction_fix_rcode(t
);
1142 /* Block GC while starting requests for additional DNSSEC RRs */
1144 r
= dns_transaction_request_dnssec_keys(t
);
1147 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1148 if (!dns_transaction_gc(t
))
1151 /* Requesting additional keys might have resulted in
1152 * this transaction to fail, since the auxiliary
1153 * request failed for some reason. If so, we are not
1154 * in pending state anymore, and we should exit
1156 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1161 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1162 t
->state
= DNS_TRANSACTION_VALIDATING
;
1163 dns_transaction_close_connection(t
);
1164 dns_transaction_stop_timeout(t
);
1169 dns_transaction_process_dnssec(t
);
1173 t
->answer_errno
= -r
;
1174 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1177 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1178 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1179 DnsTransaction
*t
= userdata
;
1185 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1186 if (ERRNO_IS_DISCONNECT(-r
)) {
1189 /* UDP connection failure get reported via ICMP and then are possible delivered to us on the next
1190 * recvmsg(). Treat this like a lost packet. */
1192 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1193 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1194 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1196 dns_transaction_retry(t
, true);
1200 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
1201 t
->answer_errno
= -r
;
1205 r
= dns_packet_validate_reply(p
);
1207 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1211 log_debug("Received inappropriate DNS packet as response, ignoring.");
1215 if (DNS_PACKET_ID(p
) != t
->id
) {
1216 log_debug("Received packet with incorrect transaction ID, ignoring.");
1220 dns_transaction_process_reply(t
, p
);
1224 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1229 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1231 r
= dns_transaction_pick_server(t
);
1235 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1236 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1238 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1241 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1244 dns_transaction_close_connection(t
);
1246 fd
= dns_scope_socket_udp(t
->scope
, t
->server
, 53);
1250 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1256 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1260 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1264 dns_transaction_close_connection(t
);
1266 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1270 dns_transaction_reset_answer(t
);
1275 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1276 DnsTransaction
*t
= userdata
;
1281 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1282 /* Timeout reached? Increase the timeout for the server used */
1283 switch (t
->scope
->protocol
) {
1285 case DNS_PROTOCOL_DNS
:
1287 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1290 case DNS_PROTOCOL_LLMNR
:
1291 case DNS_PROTOCOL_MDNS
:
1292 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1296 assert_not_reached("Invalid DNS protocol.");
1299 if (t
->initial_jitter_scheduled
)
1300 t
->initial_jitter_elapsed
= true;
1303 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1305 dns_transaction_retry(t
, true);
1309 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1313 switch (t
->scope
->protocol
) {
1315 case DNS_PROTOCOL_DNS
:
1317 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1318 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1321 return TRANSACTION_TCP_TIMEOUT_USEC
;
1323 return DNS_TIMEOUT_USEC
;
1325 case DNS_PROTOCOL_MDNS
:
1326 assert(t
->n_attempts
> 0);
1328 return MDNS_PROBING_INTERVAL_USEC
;
1330 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1332 case DNS_PROTOCOL_LLMNR
:
1333 return t
->scope
->resend_timeout
;
1336 assert_not_reached("Invalid DNS protocol.");
1340 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1345 dns_transaction_stop_timeout(t
);
1347 if (!dns_scope_network_good(t
->scope
)) {
1348 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1352 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1353 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1357 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1358 /* If we already tried via a stream, then we don't
1359 * retry on LLMNR. See RFC 4795, Section 2.7. */
1360 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1367 dns_transaction_reset_answer(t
);
1368 dns_transaction_flush_dnssec_transactions(t
);
1370 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1371 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1372 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1376 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1377 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1378 t
->answer_authenticated
= true;
1379 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1383 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1384 t
->key
->type
== DNS_TYPE_DS
) {
1386 /* Hmm, this is a request for the root DS? A
1387 * DS RR doesn't exist in the root zone, and
1388 * if our trust anchor didn't know it either,
1389 * this means we cannot do any DNSSEC logic
1392 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1393 /* We are in downgrade mode. In this
1394 * case, synthesize an unsigned empty
1395 * response, so that the any lookup
1396 * depending on this one can continue
1397 * assuming there was no DS, and hence
1398 * the root zone was unsigned. */
1400 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1401 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1402 t
->answer_authenticated
= false;
1403 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1405 /* If we are not in downgrade mode,
1406 * then fail the lookup, because we
1407 * cannot reasonably answer it. There
1408 * might be DS RRs, but we don't know
1409 * them, and the DNS server won't tell
1410 * them to us (and even if it would,
1411 * we couldn't validate and trust them. */
1412 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1418 /* Check the zone, but only if this transaction is not used
1419 * for probing or verifying a zone item. */
1420 if (set_isempty(t
->notify_zone_items
)) {
1422 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1426 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1427 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1428 t
->answer_authenticated
= true;
1429 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1434 /* Check the cache, but only if this transaction is not used
1435 * for probing or verifying a zone item. */
1436 if (set_isempty(t
->notify_zone_items
)) {
1438 /* Before trying the cache, let's make sure we figured out a
1439 * server to use. Should this cause a change of server this
1440 * might flush the cache. */
1441 (void) dns_scope_get_dns_server(t
->scope
);
1443 /* Let's then prune all outdated entries */
1444 dns_cache_prune(&t
->scope
->cache
);
1446 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1450 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1451 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1452 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1454 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1462 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1464 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1465 bool add_known_answers
= false;
1466 DnsTransaction
*other
;
1468 DnsResourceKey
*tkey
;
1469 _cleanup_set_free_ Set
*keys
= NULL
;
1471 unsigned nscount
= 0;
1476 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1478 /* Discard any previously prepared packet, so we can start over and coalesce again */
1479 t
->sent
= dns_packet_unref(t
->sent
);
1481 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1485 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1491 if (dns_key_is_shared(t
->key
))
1492 add_known_answers
= true;
1494 if (t
->key
->type
== DNS_TYPE_ANY
) {
1495 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1499 r
= set_put(keys
, t
->key
);
1505 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1506 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1507 * in our current scope, and see whether their timing contraints allow them to be sent.
1510 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1512 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1514 /* Skip ourselves */
1518 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1521 if (other
->next_attempt_after
> ts
)
1524 if (qdcount
>= UINT16_MAX
)
1527 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1530 * If we can't stuff more questions into the packet, just give up.
1531 * One of the 'other' transactions will fire later and take care of the rest.
1539 r
= dns_transaction_prepare(other
, ts
);
1543 ts
+= transaction_get_resend_timeout(other
);
1545 r
= sd_event_add_time(
1546 other
->scope
->manager
->event
,
1547 &other
->timeout_event_source
,
1548 clock_boottime_or_monotonic(),
1550 on_transaction_timeout
, other
);
1554 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1556 other
->state
= DNS_TRANSACTION_PENDING
;
1557 other
->next_attempt_after
= ts
;
1561 if (dns_key_is_shared(other
->key
))
1562 add_known_answers
= true;
1564 if (other
->key
->type
== DNS_TYPE_ANY
) {
1565 r
= set_ensure_allocated(&keys
, &dns_resource_key_hash_ops
);
1569 r
= set_put(keys
, other
->key
);
1575 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1577 /* Append known answer section if we're asking for any shared record */
1578 if (add_known_answers
) {
1579 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1584 SET_FOREACH(tkey
, keys
, i
) {
1585 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1588 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1592 r
= dns_packet_append_answer(p
, answer
);
1596 nscount
+= dns_answer_size(answer
);
1598 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1600 t
->sent
= TAKE_PTR(p
);
1605 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1606 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1611 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1612 return dns_transaction_make_packet_mdns(t
);
1617 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1621 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1625 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1626 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1628 t
->sent
= TAKE_PTR(p
);
1633 int dns_transaction_go(DnsTransaction
*t
) {
1636 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1640 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1643 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1645 r
= dns_transaction_prepare(t
, ts
);
1649 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1651 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1652 dns_protocol_to_string(t
->scope
->protocol
),
1653 t
->scope
->link
? t
->scope
->link
->name
: "*",
1654 af_to_name_short(t
->scope
->family
));
1656 if (!t
->initial_jitter_scheduled
&&
1657 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1658 usec_t jitter
, accuracy
;
1660 /* RFC 4795 Section 2.7 suggests all queries should be
1661 * delayed by a random time from 0 to JITTER_INTERVAL. */
1663 t
->initial_jitter_scheduled
= true;
1665 random_bytes(&jitter
, sizeof(jitter
));
1667 switch (t
->scope
->protocol
) {
1669 case DNS_PROTOCOL_LLMNR
:
1670 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1671 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1674 case DNS_PROTOCOL_MDNS
:
1675 jitter
%= MDNS_JITTER_RANGE_USEC
;
1676 jitter
+= MDNS_JITTER_MIN_USEC
;
1677 accuracy
= MDNS_JITTER_RANGE_USEC
;
1680 assert_not_reached("bad protocol");
1683 r
= sd_event_add_time(
1684 t
->scope
->manager
->event
,
1685 &t
->timeout_event_source
,
1686 clock_boottime_or_monotonic(),
1687 ts
+ jitter
, accuracy
,
1688 on_transaction_timeout
, t
);
1692 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1695 t
->next_attempt_after
= ts
;
1696 t
->state
= DNS_TRANSACTION_PENDING
;
1698 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1702 /* Otherwise, we need to ask the network */
1703 r
= dns_transaction_make_packet(t
);
1707 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1708 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1709 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1711 /* RFC 4795, Section 2.4. says reverse lookups shall
1712 * always be made via TCP on LLMNR */
1713 r
= dns_transaction_emit_tcp(t
);
1715 /* Try via UDP, and if that fails due to large size or lack of
1716 * support try via TCP */
1717 r
= dns_transaction_emit_udp(t
);
1719 log_debug("Sending query via TCP since it is too large.");
1720 else if (r
== -EAGAIN
)
1721 log_debug("Sending query via TCP since UDP isn't supported.");
1722 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1723 r
= dns_transaction_emit_tcp(t
);
1727 /* No servers to send this to? */
1728 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1731 if (r
== -EOPNOTSUPP
) {
1732 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1733 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1736 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(-r
)) {
1737 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1738 * answer this request with this protocol. */
1739 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1743 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1746 /* Couldn't send? Try immediately again, with a new server */
1747 dns_scope_next_dns_server(t
->scope
);
1749 return dns_transaction_go(t
);
1752 ts
+= transaction_get_resend_timeout(t
);
1754 r
= sd_event_add_time(
1755 t
->scope
->manager
->event
,
1756 &t
->timeout_event_source
,
1757 clock_boottime_or_monotonic(),
1759 on_transaction_timeout
, t
);
1763 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1765 t
->state
= DNS_TRANSACTION_PENDING
;
1766 t
->next_attempt_after
= ts
;
1771 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1779 /* Try to find cyclic dependencies between transaction objects */
1784 SET_FOREACH(n
, aux
->dnssec_transactions
, i
) {
1785 r
= dns_transaction_find_cyclic(t
, n
);
1793 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1794 DnsTransaction
*aux
;
1801 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1803 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1807 if (set_contains(t
->dnssec_transactions
, aux
)) {
1812 r
= dns_transaction_find_cyclic(t
, aux
);
1816 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1818 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1819 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1821 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1823 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1827 r
= set_ensure_allocated(&t
->dnssec_transactions
, NULL
);
1831 r
= set_ensure_allocated(&aux
->notify_transactions
, NULL
);
1835 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1839 r
= set_put(t
->dnssec_transactions
, aux
);
1843 r
= set_put(aux
->notify_transactions
, t
);
1845 (void) set_remove(t
->dnssec_transactions
, aux
);
1853 dns_transaction_gc(aux
);
1857 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1858 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1859 DnsTransaction
*aux
;
1865 /* Try to get the data from the trust anchor */
1866 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1870 r
= dns_answer_extend(&t
->validated_keys
, a
);
1877 /* This didn't work, ask for it via the network/cache then. */
1878 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1879 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1884 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1885 r
= dns_transaction_go(aux
);
1893 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1898 /* Check whether the specified name is in the NTA
1899 * database, either in the global one, or the link-local
1902 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1906 if (!t
->scope
->link
)
1909 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1912 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1917 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1918 * RRs to prove it */
1920 r
= dns_transaction_has_positive_answer(t
, NULL
);
1926 /* Is this key explicitly listed as a negative trust anchor?
1927 * If so, it's nothing we need to care about */
1928 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1934 /* The answer does not contain any RRs that match to the
1935 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1936 * included. If not, the answer is unsigned. */
1938 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1947 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1953 /* Check if the specified RR is the "primary" response,
1954 * i.e. either matches the question precisely or is a
1955 * CNAME/DNAME for it. */
1957 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1961 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1964 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1967 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1968 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1970 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1973 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1974 * be supported, hence return true. */
1978 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1979 * the server is known to support currently, as the transaction feature level might be lower than what the
1980 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1981 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1983 return dns_server_dnssec_supported(t
->server
);
1986 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1992 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1994 if (!dns_transaction_dnssec_supported(t
))
1997 SET_FOREACH(dt
, t
->dnssec_transactions
, i
)
1998 if (!dns_transaction_dnssec_supported(dt
))
2004 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
2005 DnsResourceRecord
*rr
;
2012 * Retrieve all auxiliary RRs for the answer we got, so that
2013 * we can verify signatures or prove that RRs are rightfully
2014 * unsigned. Specifically:
2016 * - For RRSIG we get the matching DNSKEY
2017 * - For DNSKEY we get the matching DS
2018 * - For unsigned SOA/NS we get the matching DS
2019 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2020 * - For other unsigned RRs we get the matching SOA RR
2021 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2022 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2023 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2026 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2028 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2029 return 0; /* We only need to validate stuff from the network */
2030 if (!dns_transaction_dnssec_supported(t
))
2031 return 0; /* If we can't do DNSSEC anyway there's no point in geting the auxiliary RRs */
2033 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2035 if (dns_type_is_pseudo(rr
->key
->type
))
2038 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2039 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2045 switch (rr
->key
->type
) {
2047 case DNS_TYPE_RRSIG
: {
2048 /* For each RRSIG we request the matching DNSKEY */
2049 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2051 /* If this RRSIG is about a DNSKEY RR and the
2052 * signer is the same as the owner, then we
2053 * already have the DNSKEY, and we don't have
2054 * to look for more. */
2055 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2056 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2063 /* If the signer is not a parent of our
2064 * original query, then this is about an
2065 * auxiliary RRset, but not anything we asked
2066 * for. In this case we aren't interested,
2067 * because we don't want to request additional
2068 * RRs for stuff we didn't really ask for, and
2069 * also to avoid request loops, where
2070 * additional RRs from one transaction result
2071 * in another transaction whose additonal RRs
2072 * point back to the original transaction, and
2074 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2080 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2084 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2085 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2086 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2092 case DNS_TYPE_DNSKEY
: {
2093 /* For each DNSKEY we request the matching DS */
2094 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2096 /* If the DNSKEY we are looking at is not for
2097 * zone we are interested in, nor any of its
2098 * parents, we aren't interested, and don't
2099 * request it. After all, we don't want to end
2100 * up in request loops, and want to keep
2101 * additional traffic down. */
2103 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2109 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2113 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2114 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2115 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2124 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2126 /* For an unsigned SOA or NS, try to acquire
2127 * the matching DS RR, as we are at a zone cut
2128 * then, and whether a DS exists tells us
2129 * whether the zone is signed. Do so only if
2130 * this RR matches our original question,
2133 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2137 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2138 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2139 * If so, we need to validate it, too. */
2141 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2144 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2149 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2155 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2159 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2160 t
->id
, dns_resource_key_name(rr
->key
));
2161 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2169 case DNS_TYPE_CNAME
:
2170 case DNS_TYPE_DNAME
: {
2171 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2174 /* CNAMEs and DNAMEs cannot be located at a
2175 * zone apex, hence ask for the parent SOA for
2176 * unsigned CNAME/DNAME RRs, maybe that's the
2177 * apex. But do all that only if this is
2178 * actually a response to our original
2181 * Similar for DS RRs, which are signed when
2182 * the parent SOA is signed. */
2184 r
= dns_transaction_is_primary_response(t
, rr
);
2190 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2196 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2202 name
= dns_resource_key_name(rr
->key
);
2203 r
= dns_name_parent(&name
);
2209 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2213 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2214 t
->id
, dns_resource_key_name(rr
->key
));
2215 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2223 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2225 /* For other unsigned RRsets (including
2226 * NSEC/NSEC3!), look for proof the zone is
2227 * unsigned, by requesting the SOA RR of the
2228 * zone. However, do so only if they are
2229 * directly relevant to our original
2232 r
= dns_transaction_is_primary_response(t
, rr
);
2238 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2244 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2248 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2249 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2250 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2257 /* Above, we requested everything necessary to validate what
2258 * we got. Now, let's request what we need to validate what we
2261 r
= dns_transaction_has_unsigned_negative_answer(t
);
2268 name
= dns_resource_key_name(t
->key
);
2270 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2271 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2272 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2273 * though they have further children. If this was a DS request, then it's signed when the parent zone
2274 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2275 * to see if that is signed. */
2277 if (t
->key
->type
== DNS_TYPE_DS
) {
2278 r
= dns_name_parent(&name
);
2280 type
= DNS_TYPE_SOA
;
2281 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2282 t
->id
, dns_resource_key_name(t
->key
));
2286 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2289 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2290 t
->id
, dns_resource_key_name(t
->key
));
2293 type
= DNS_TYPE_SOA
;
2294 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2295 t
->id
, dns_resource_key_name(t
->key
));
2299 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2301 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2305 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2311 return dns_transaction_dnssec_is_live(t
);
2314 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2318 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2319 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2320 the state is VALIDATING however, we should check if we are complete now. */
2322 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2323 dns_transaction_process_dnssec(t
);
2326 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2327 DnsResourceRecord
*rr
;
2332 /* Add all DNSKEY RRs from the answer that are validated by DS
2333 * RRs from the list of validated keys to the list of
2334 * validated keys. */
2336 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2338 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2344 /* If so, the DNSKEY is validated too. */
2345 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2353 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2359 /* Checks if the RR we are looking for must be signed with an
2360 * RRSIG. This is used for positive responses. */
2362 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2365 if (dns_type_is_pseudo(rr
->key
->type
))
2368 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2374 switch (rr
->key
->type
) {
2376 case DNS_TYPE_RRSIG
:
2377 /* RRSIGs are the signatures themselves, they need no signing. */
2385 /* For SOA or NS RRs we look for a matching DS transaction */
2387 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2389 if (dt
->key
->class != rr
->key
->class)
2391 if (dt
->key
->type
!= DNS_TYPE_DS
)
2394 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2400 /* We found a DS transactions for the SOA/NS
2401 * RRs we are looking at. If it discovered signed DS
2402 * RRs, then we need to be signed, too. */
2404 if (!dt
->answer_authenticated
)
2407 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2410 /* We found nothing that proves this is safe to leave
2411 * this unauthenticated, hence ask inist on
2412 * authentication. */
2417 case DNS_TYPE_CNAME
:
2418 case DNS_TYPE_DNAME
: {
2419 const char *parent
= NULL
;
2424 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2426 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2429 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2431 if (dt
->key
->class != rr
->key
->class)
2433 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2437 parent
= dns_resource_key_name(rr
->key
);
2438 r
= dns_name_parent(&parent
);
2442 if (rr
->key
->type
== DNS_TYPE_DS
)
2445 /* A CNAME/DNAME without a parent? That's sooo weird. */
2446 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2447 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2451 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2457 return t
->answer_authenticated
;
2467 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2469 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2471 if (dt
->key
->class != rr
->key
->class)
2473 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2476 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2482 /* We found the transaction that was supposed to find
2483 * the SOA RR for us. It was successful, but found no
2484 * RR for us. This means we are not at a zone cut. In
2485 * this case, we require authentication if the SOA
2486 * lookup was authenticated too. */
2487 return t
->answer_authenticated
;
2494 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2500 /* If DNSSEC downgrade mode is on, checks whether the
2501 * specified RR is one level below a TLD we have proven not to
2502 * exist. In such a case we assume that this is a private
2503 * domain, and permit it.
2505 * This detects cases like the Fritz!Box router networks. Each
2506 * Fritz!Box router serves a private "fritz.box" zone, in the
2507 * non-existing TLD "box". Requests for the "fritz.box" domain
2508 * are served by the router itself, while requests for the
2509 * "box" domain will result in NXDOMAIN.
2511 * Note that this logic is unable to detect cases where a
2512 * router serves a private DNS zone directly under
2513 * non-existing TLD. In such a case we cannot detect whether
2514 * the TLD is supposed to exist or not, as all requests we
2515 * make for it will be answered by the router's zone, and not
2516 * by the root zone. */
2520 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2521 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2523 tld
= dns_resource_key_name(key
);
2524 r
= dns_name_parent(&tld
);
2528 return false; /* Already the root domain */
2530 if (!dns_name_is_single_label(tld
))
2533 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2535 if (dt
->key
->class != key
->class)
2538 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2544 /* We found an auxiliary lookup we did for the TLD. If
2545 * that returned with NXDOMAIN, we know the TLD didn't
2546 * exist, and hence this might be a private zone. */
2548 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2554 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2555 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2564 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2565 * this negative reply */
2567 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2570 if (dns_type_is_pseudo(t
->key
->type
))
2573 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2579 r
= dns_transaction_in_private_tld(t
, t
->key
);
2583 /* The lookup is from a TLD that is proven not to
2584 * exist, and we are in downgrade mode, hence ignore
2585 * that fact that we didn't get any NSEC RRs. */
2587 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2588 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2592 name
= dns_resource_key_name(t
->key
);
2594 if (t
->key
->type
== DNS_TYPE_DS
) {
2596 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2597 * hence check the parent SOA in this case. */
2599 r
= dns_name_parent(&name
);
2605 type
= DNS_TYPE_SOA
;
2607 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2608 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2611 /* For all other negative replies, check for the SOA lookup */
2612 type
= DNS_TYPE_SOA
;
2614 /* For all other RRs we check the SOA on the same level to see
2615 * if it's signed. */
2617 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2619 if (dt
->key
->class != t
->key
->class)
2621 if (dt
->key
->type
!= type
)
2624 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2630 return dt
->answer_authenticated
;
2633 /* If in doubt, require NSEC/NSEC3 */
2637 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2638 DnsResourceRecord
*rrsig
;
2642 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2643 * the specified RRset is authenticated (i.e. has a matching
2646 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2652 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2656 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2662 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2664 if (dt
->key
->class != rr
->key
->class)
2667 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2669 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2675 /* OK, we found an auxiliary DNSKEY
2676 * lookup. If that lookup is
2677 * authenticated, report this. */
2679 if (dt
->answer_authenticated
)
2684 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2686 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2692 /* OK, we found an auxiliary DS
2693 * lookup. If that lookup is
2694 * authenticated and non-zero, we
2697 if (!dt
->answer_authenticated
)
2700 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2705 return found
? false : -ENXIO
;
2708 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2712 /* We know that the root domain is signed, hence if it appears
2713 * not to be signed, there's a problem with the DNS server */
2715 return rr
->key
->class == DNS_CLASS_IN
&&
2716 dns_name_is_root(dns_resource_key_name(rr
->key
));
2719 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2720 DnsResourceRecord
*rr
;
2725 /* Maybe warn the user that we encountered a revoked DNSKEY
2726 * for a key from our trust anchor. Note that we don't care
2727 * whether the DNSKEY can be authenticated or not. It's
2728 * sufficient if it is self-signed. */
2730 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2731 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2739 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2745 /* Removes all DNSKEY/DS objects from t->validated_keys that
2746 * our trust anchors database considers revoked. */
2749 DnsResourceRecord
*rr
;
2753 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2754 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2758 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2772 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2779 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2781 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2783 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2786 if (!dt
->answer_authenticated
)
2789 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2798 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2799 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2800 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2803 static int dnssec_validate_records(
2807 DnsAnswer
**validated
) {
2809 DnsResourceRecord
*rr
;
2812 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2814 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2815 DnsResourceRecord
*rrsig
= NULL
;
2816 DnssecResult result
;
2818 switch (rr
->key
->type
) {
2819 case DNS_TYPE_RRSIG
:
2822 case DNS_TYPE_DNSKEY
:
2823 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2824 if (phase
== DNSSEC_PHASE_NSEC
)
2829 case DNS_TYPE_NSEC3
:
2832 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2833 if (phase
== DNSSEC_PHASE_DNSKEY
)
2838 /* We validate all other RRs only in the ALL phases */
2839 if (phase
!= DNSSEC_PHASE_ALL
)
2843 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2847 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2849 if (result
== DNSSEC_VALIDATED
) {
2851 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2852 /* If we just validated a DNSKEY RRset, then let's add these keys to
2853 * the set of validated keys for this transaction. */
2855 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2859 /* Some of the DNSKEYs we just added might already have been revoked,
2860 * remove them again in that case. */
2861 r
= dns_transaction_invalidate_revoked_keys(t
);
2866 /* Add the validated RRset to the new list of validated
2867 * RRsets, and remove it from the unvalidated RRsets.
2868 * We mark the RRset as authenticated and cacheable. */
2869 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2873 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2875 /* Exit the loop, we dropped something from the answer, start from the beginning */
2879 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2880 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2881 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2882 if (phase
!= DNSSEC_PHASE_ALL
)
2885 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2886 bool authenticated
= false;
2889 /* This RRset validated, but as a wildcard. This means we need
2890 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2892 /* First step, determine the source of synthesis */
2893 r
= dns_resource_record_source(rrsig
, &source
);
2897 r
= dnssec_test_positive_wildcard(*validated
,
2898 dns_resource_key_name(rr
->key
),
2900 rrsig
->rrsig
.signer
,
2903 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2905 result
= DNSSEC_INVALID
;
2907 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2908 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2912 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2914 /* Exit the loop, we dropped something from the answer, start from the beginning */
2919 if (result
== DNSSEC_NO_SIGNATURE
) {
2920 r
= dns_transaction_requires_rrsig(t
, rr
);
2924 /* Data does not require signing. In that case, just copy it over,
2925 * but remember that this is by no means authenticated. */
2926 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2930 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2934 r
= dns_transaction_known_signed(t
, rr
);
2938 /* This is an RR we know has to be signed. If it isn't this means
2939 * the server is not attaching RRSIGs, hence complain. */
2941 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2943 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2945 /* Downgrading is OK? If so, just consider the information unsigned */
2947 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2951 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2955 /* Otherwise, fail */
2956 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2960 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2964 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2966 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2967 * mode, hence ignore the fact that this was not signed. */
2969 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2970 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2972 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2976 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2983 DNSSEC_SIGNATURE_EXPIRED
,
2984 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2986 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2987 if (r
< 0 && r
!= -ENXIO
)
2990 /* The DNSKEY transaction was not authenticated, this means there's
2991 * no DS for this, which means it's OK if no keys are found for this signature. */
2993 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2997 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
3002 r
= dns_transaction_is_primary_response(t
, rr
);
3006 /* Look for a matching DNAME for this CNAME */
3007 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
3011 /* Also look among the stuff we already validated */
3012 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3020 DNSSEC_SIGNATURE_EXPIRED
,
3021 DNSSEC_NO_SIGNATURE
))
3022 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3023 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3024 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3026 /* This is a primary response to our question, and it failed validation.
3028 t
->answer_dnssec_result
= result
;
3032 /* This is a primary response, but we do have a DNAME RR
3033 * in the RR that can replay this CNAME, hence rely on
3034 * that, and we can remove the CNAME in favour of it. */
3037 /* This is just some auxiliary data. Just remove the RRset and continue. */
3038 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3042 /* We dropped something from the answer, start from the beginning. */
3046 return 2; /* Finito. */
3049 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3050 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3052 DnsAnswerFlags flags
;
3054 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3058 /* We have now collected all DS and DNSKEY RRs in
3059 * t->validated_keys, let's see which RRs we can now
3060 * authenticate with that. */
3062 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3065 /* Already validated */
3066 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3069 /* Our own stuff needs no validation */
3070 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3071 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3072 t
->answer_authenticated
= true;
3076 /* Cached stuff is not affected by validation. */
3077 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3080 if (!dns_transaction_dnssec_supported_full(t
)) {
3081 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3082 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3083 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3087 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3089 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3091 /* First, see if this response contains any revoked trust
3092 * anchors we care about */
3093 r
= dns_transaction_check_revoked_trust_anchors(t
);
3097 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3098 r
= dns_transaction_copy_validated(t
);
3102 /* Second, see if there are DNSKEYs we already know a
3103 * validated DS for. */
3104 r
= dns_transaction_validate_dnskey_by_ds(t
);
3108 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3109 * anchor says are revoked. After all we might have marked
3110 * some keys revoked above, but they might still be lingering
3111 * in our validated_keys list. */
3112 r
= dns_transaction_invalidate_revoked_keys(t
);
3116 phase
= DNSSEC_PHASE_DNSKEY
;
3118 bool have_nsec
= false;
3120 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3124 /* Try again as long as we managed to achieve something */
3128 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3129 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3130 phase
= DNSSEC_PHASE_NSEC
;
3134 if (phase
!= DNSSEC_PHASE_ALL
) {
3135 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3136 * Note that in this third phase we start to remove RRs we couldn't validate. */
3137 phase
= DNSSEC_PHASE_ALL
;
3145 dns_answer_unref(t
->answer
);
3146 t
->answer
= TAKE_PTR(validated
);
3148 /* At this point the answer only contains validated
3149 * RRsets. Now, let's see if it actually answers the question
3150 * we asked. If so, great! If it doesn't, then see if
3151 * NSEC/NSEC3 can prove this. */
3152 r
= dns_transaction_has_positive_answer(t
, &flags
);
3154 /* Yes, it answers the question! */
3156 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3157 /* The answer is fully authenticated, yay. */
3158 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3159 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3160 t
->answer_authenticated
= true;
3162 /* The answer is not fully authenticated. */
3163 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3164 t
->answer_authenticated
= false;
3167 } else if (r
== 0) {
3168 DnssecNsecResult nr
;
3169 bool authenticated
= false;
3171 /* Bummer! Let's check NSEC/NSEC3 */
3172 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3178 case DNSSEC_NSEC_NXDOMAIN
:
3179 /* NSEC proves the domain doesn't exist. Very good. */
3180 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3181 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3182 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3183 t
->answer_authenticated
= authenticated
;
3185 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3188 case DNSSEC_NSEC_NODATA
:
3189 /* NSEC proves that there's no data here, very good. */
3190 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3191 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3192 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3193 t
->answer_authenticated
= authenticated
;
3195 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3198 case DNSSEC_NSEC_OPTOUT
:
3199 /* NSEC3 says the data might not be signed */
3200 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3201 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3202 t
->answer_authenticated
= false;
3204 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3207 case DNSSEC_NSEC_NO_RR
:
3208 /* No NSEC data? Bummer! */
3210 r
= dns_transaction_requires_nsec(t
);
3214 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3215 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3217 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3218 t
->answer_authenticated
= false;
3219 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3224 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3225 /* We don't know the NSEC3 algorithm used? */
3226 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3227 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3230 case DNSSEC_NSEC_FOUND
:
3231 case DNSSEC_NSEC_CNAME
:
3232 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3233 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3234 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3238 assert_not_reached("Unexpected NSEC result.");
3245 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3246 [DNS_TRANSACTION_NULL
] = "null",
3247 [DNS_TRANSACTION_PENDING
] = "pending",
3248 [DNS_TRANSACTION_VALIDATING
] = "validating",
3249 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3250 [DNS_TRANSACTION_SUCCESS
] = "success",
3251 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3252 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3253 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3254 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3255 [DNS_TRANSACTION_ERRNO
] = "errno",
3256 [DNS_TRANSACTION_ABORTED
] = "aborted",
3257 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3258 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3259 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3260 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3261 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3263 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3265 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3266 [DNS_TRANSACTION_NETWORK
] = "network",
3267 [DNS_TRANSACTION_CACHE
] = "cache",
3268 [DNS_TRANSACTION_ZONE
] = "zone",
3269 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3271 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);