1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #include "sd-messages.h"
6 #include "alloc-util.h"
7 #include "dns-domain.h"
8 #include "errno-list.h"
9 #include "errno-util.h"
11 #include "random-util.h"
12 #include "resolved-dns-cache.h"
13 #include "resolved-dns-transaction.h"
14 #include "resolved-dnstls.h"
15 #include "resolved-llmnr.h"
16 #include "string-table.h"
18 #define TRANSACTIONS_MAX 4096
19 #define TRANSACTION_TCP_TIMEOUT_USEC (10U*USEC_PER_SEC)
21 /* After how much time to repeat classic DNS requests */
22 #define DNS_TIMEOUT_USEC (SD_RESOLVED_QUERY_TIMEOUT_USEC / DNS_TRANSACTION_ATTEMPTS_MAX)
24 static void dns_transaction_reset_answer(DnsTransaction
*t
) {
27 t
->received
= dns_packet_unref(t
->received
);
28 t
->answer
= dns_answer_unref(t
->answer
);
30 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
31 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
32 t
->answer_authenticated
= false;
33 t
->answer_nsec_ttl
= (uint32_t) -1;
37 static void dns_transaction_flush_dnssec_transactions(DnsTransaction
*t
) {
42 while ((z
= set_steal_first(t
->dnssec_transactions
))) {
43 set_remove(z
->notify_transactions
, t
);
44 set_remove(z
->notify_transactions_done
, t
);
45 dns_transaction_gc(z
);
49 static void dns_transaction_close_connection(DnsTransaction
*t
) {
53 /* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
54 LIST_REMOVE(transactions_by_stream
, t
->stream
->transactions
, t
);
56 /* Remove packet in case it's still in the queue */
57 dns_packet_unref(ordered_set_remove(t
->stream
->write_queue
, t
->sent
));
59 t
->stream
= dns_stream_unref(t
->stream
);
62 t
->dns_udp_event_source
= sd_event_source_unref(t
->dns_udp_event_source
);
63 t
->dns_udp_fd
= safe_close(t
->dns_udp_fd
);
66 static void dns_transaction_stop_timeout(DnsTransaction
*t
) {
69 t
->timeout_event_source
= sd_event_source_unref(t
->timeout_event_source
);
72 DnsTransaction
* dns_transaction_free(DnsTransaction
*t
) {
80 log_debug("Freeing transaction %" PRIu16
".", t
->id
);
82 dns_transaction_close_connection(t
);
83 dns_transaction_stop_timeout(t
);
85 dns_packet_unref(t
->sent
);
86 dns_transaction_reset_answer(t
);
88 dns_server_unref(t
->server
);
91 hashmap_remove_value(t
->scope
->transactions_by_key
, t
->key
, t
);
92 LIST_REMOVE(transactions_by_scope
, t
->scope
->transactions
, t
);
95 hashmap_remove(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
98 while ((c
= set_steal_first(t
->notify_query_candidates
)))
99 set_remove(c
->transactions
, t
);
100 set_free(t
->notify_query_candidates
);
102 while ((c
= set_steal_first(t
->notify_query_candidates_done
)))
103 set_remove(c
->transactions
, t
);
104 set_free(t
->notify_query_candidates_done
);
106 while ((i
= set_steal_first(t
->notify_zone_items
)))
107 i
->probe_transaction
= NULL
;
108 set_free(t
->notify_zone_items
);
110 while ((i
= set_steal_first(t
->notify_zone_items_done
)))
111 i
->probe_transaction
= NULL
;
112 set_free(t
->notify_zone_items_done
);
114 while ((z
= set_steal_first(t
->notify_transactions
)))
115 set_remove(z
->dnssec_transactions
, t
);
116 set_free(t
->notify_transactions
);
118 while ((z
= set_steal_first(t
->notify_transactions_done
)))
119 set_remove(z
->dnssec_transactions
, t
);
120 set_free(t
->notify_transactions_done
);
122 dns_transaction_flush_dnssec_transactions(t
);
123 set_free(t
->dnssec_transactions
);
125 dns_answer_unref(t
->validated_keys
);
126 dns_resource_key_unref(t
->key
);
131 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction
*, dns_transaction_free
);
133 bool dns_transaction_gc(DnsTransaction
*t
) {
139 if (set_isempty(t
->notify_query_candidates
) &&
140 set_isempty(t
->notify_query_candidates_done
) &&
141 set_isempty(t
->notify_zone_items
) &&
142 set_isempty(t
->notify_zone_items_done
) &&
143 set_isempty(t
->notify_transactions
) &&
144 set_isempty(t
->notify_transactions_done
)) {
145 dns_transaction_free(t
);
152 static uint16_t pick_new_id(Manager
*m
) {
155 /* Find a fresh, unused transaction id. Note that this loop is bounded because there's a limit on the number of
156 * transactions, and it's much lower than the space of IDs. */
158 assert_cc(TRANSACTIONS_MAX
< 0xFFFF);
161 random_bytes(&new_id
, sizeof(new_id
));
162 while (new_id
== 0 ||
163 hashmap_get(m
->dns_transactions
, UINT_TO_PTR(new_id
)));
168 int dns_transaction_new(DnsTransaction
**ret
, DnsScope
*s
, DnsResourceKey
*key
) {
169 _cleanup_(dns_transaction_freep
) DnsTransaction
*t
= NULL
;
176 /* Don't allow looking up invalid or pseudo RRs */
177 if (!dns_type_is_valid_query(key
->type
))
179 if (dns_type_is_obsolete(key
->type
))
182 /* We only support the IN class */
183 if (!IN_SET(key
->class, DNS_CLASS_IN
, DNS_CLASS_ANY
))
186 if (hashmap_size(s
->manager
->dns_transactions
) >= TRANSACTIONS_MAX
)
189 r
= hashmap_ensure_allocated(&s
->manager
->dns_transactions
, NULL
);
193 r
= hashmap_ensure_allocated(&s
->transactions_by_key
, &dns_resource_key_hash_ops
);
197 t
= new0(DnsTransaction
, 1);
202 t
->answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
;
203 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
204 t
->answer_nsec_ttl
= (uint32_t) -1;
205 t
->key
= dns_resource_key_ref(key
);
206 t
->current_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
207 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
209 t
->id
= pick_new_id(s
->manager
);
211 r
= hashmap_put(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), t
);
217 r
= hashmap_replace(s
->transactions_by_key
, t
->key
, t
);
219 hashmap_remove(s
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
));
223 LIST_PREPEND(transactions_by_scope
, s
->transactions
, t
);
226 s
->manager
->n_transactions_total
++;
236 static void dns_transaction_shuffle_id(DnsTransaction
*t
) {
240 /* Pick a new ID for this transaction. */
242 new_id
= pick_new_id(t
->scope
->manager
);
243 assert_se(hashmap_remove_and_put(t
->scope
->manager
->dns_transactions
, UINT_TO_PTR(t
->id
), UINT_TO_PTR(new_id
), t
) >= 0);
245 log_debug("Transaction %" PRIu16
" is now %" PRIu16
".", t
->id
, new_id
);
248 /* Make sure we generate a new packet with the new ID */
249 t
->sent
= dns_packet_unref(t
->sent
);
252 static void dns_transaction_tentative(DnsTransaction
*t
, DnsPacket
*p
) {
253 _cleanup_free_
char *pretty
= NULL
;
254 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
260 if (manager_our_packet(t
->scope
->manager
, p
) != 0)
263 (void) in_addr_to_string(p
->family
, &p
->sender
, &pretty
);
265 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s got tentative packet from %s.",
267 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
268 dns_protocol_to_string(t
->scope
->protocol
),
269 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
270 af_to_name_short(t
->scope
->family
),
273 /* RFC 4795, Section 4.1 says that the peer with the
274 * lexicographically smaller IP address loses */
275 if (memcmp(&p
->sender
, &p
->destination
, FAMILY_ADDRESS_SIZE(p
->family
)) >= 0) {
276 log_debug("Peer has lexicographically larger IP address and thus lost in the conflict.");
280 log_debug("We have the lexicographically larger IP address and thus lost in the conflict.");
284 while ((z
= set_first(t
->notify_zone_items
))) {
285 /* First, make sure the zone item drops the reference
287 dns_zone_item_probe_stop(z
);
289 /* Secondly, report this as conflict, so that we might
290 * look for a different hostname */
291 dns_zone_item_conflict(z
);
295 dns_transaction_gc(t
);
298 void dns_transaction_complete(DnsTransaction
*t
, DnsTransactionState state
) {
299 DnsQueryCandidate
*c
;
303 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
306 assert(!DNS_TRANSACTION_IS_LIVE(state
));
308 if (state
== DNS_TRANSACTION_DNSSEC_FAILED
) {
309 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
);
311 log_struct(LOG_NOTICE
,
312 "MESSAGE_ID=" SD_MESSAGE_DNSSEC_FAILURE_STR
,
313 LOG_MESSAGE("DNSSEC validation failed for question %s: %s", key_str
, dnssec_result_to_string(t
->answer_dnssec_result
)),
314 "DNS_TRANSACTION=%" PRIu16
, t
->id
,
315 "DNS_QUESTION=%s", key_str
,
316 "DNSSEC_RESULT=%s", dnssec_result_to_string(t
->answer_dnssec_result
),
317 "DNS_SERVER=%s", dns_server_string(t
->server
),
318 "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(t
->server
->possible_feature_level
));
321 /* Note that this call might invalidate the query. Callers
322 * should hence not attempt to access the query or transaction
323 * after calling this function. */
325 if (state
== DNS_TRANSACTION_ERRNO
)
326 st
= errno_to_name(t
->answer_errno
);
328 st
= dns_transaction_state_to_string(state
);
330 log_debug("Transaction %" PRIu16
" for <%s> on scope %s on %s/%s now complete with <%s> from %s (%s).",
332 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
333 dns_protocol_to_string(t
->scope
->protocol
),
334 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
335 af_to_name_short(t
->scope
->family
),
337 t
->answer_source
< 0 ? "none" : dns_transaction_source_to_string(t
->answer_source
),
338 t
->answer_authenticated
? "authenticated" : "unsigned");
342 dns_transaction_close_connection(t
);
343 dns_transaction_stop_timeout(t
);
345 /* Notify all queries that are interested, but make sure the
346 * transaction isn't freed while we are still looking at it */
349 SET_FOREACH_MOVE(c
, t
->notify_query_candidates_done
, t
->notify_query_candidates
)
350 dns_query_candidate_notify(c
);
351 SWAP_TWO(t
->notify_query_candidates
, t
->notify_query_candidates_done
);
353 SET_FOREACH_MOVE(z
, t
->notify_zone_items_done
, t
->notify_zone_items
)
354 dns_zone_item_notify(z
);
355 SWAP_TWO(t
->notify_zone_items
, t
->notify_zone_items_done
);
356 if (t
->probing
&& t
->state
== DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
)
357 (void) dns_scope_announce(t
->scope
, false);
359 SET_FOREACH_MOVE(d
, t
->notify_transactions_done
, t
->notify_transactions
)
360 dns_transaction_notify(d
, t
);
361 SWAP_TWO(t
->notify_transactions
, t
->notify_transactions_done
);
364 dns_transaction_gc(t
);
367 static int dns_transaction_pick_server(DnsTransaction
*t
) {
371 assert(t
->scope
->protocol
== DNS_PROTOCOL_DNS
);
373 /* Pick a DNS server and a feature level for it. */
375 server
= dns_scope_get_dns_server(t
->scope
);
379 /* If we changed the server invalidate the feature level clamping, as the new server might have completely
380 * different properties. */
381 if (server
!= t
->server
)
382 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
384 t
->current_feature_level
= dns_server_possible_feature_level(server
);
386 /* Clamp the feature level if that is requested. */
387 if (t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
&&
388 t
->current_feature_level
> t
->clamp_feature_level
)
389 t
->current_feature_level
= t
->clamp_feature_level
;
391 log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t
->current_feature_level
), t
->id
);
393 if (server
== t
->server
)
396 dns_server_unref(t
->server
);
397 t
->server
= dns_server_ref(server
);
399 t
->n_picked_servers
++;
401 log_debug("Using DNS server %s for transaction %u.", dns_server_string(t
->server
), t
->id
);
406 static void dns_transaction_retry(DnsTransaction
*t
, bool next_server
) {
411 log_debug("Retrying transaction %" PRIu16
".", t
->id
);
413 /* Before we try again, switch to a new server. */
415 dns_scope_next_dns_server(t
->scope
);
417 r
= dns_transaction_go(t
);
419 t
->answer_errno
= -r
;
420 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
424 static int dns_transaction_maybe_restart(DnsTransaction
*t
) {
429 /* Returns > 0 if the transaction was restarted, 0 if not */
434 if (t
->current_feature_level
<= dns_server_possible_feature_level(t
->server
))
437 /* The server's current feature level is lower than when we sent the original query. We learnt something from
438 the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to
439 restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include
440 OPT RR or DO bit. One of these cases is documented here, for example:
441 https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */
443 log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID.");
444 dns_transaction_shuffle_id(t
);
446 r
= dns_transaction_go(t
);
453 static void on_transaction_stream_error(DnsTransaction
*t
, int error
) {
456 dns_transaction_close_connection(t
);
458 if (ERRNO_IS_DISCONNECT(error
)) {
459 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
) {
460 /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
461 * question on this scope. */
462 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
466 dns_transaction_retry(t
, true);
470 t
->answer_errno
= error
;
471 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
475 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
479 dns_transaction_close_connection(t
);
481 if (dns_packet_validate_reply(p
) <= 0) {
482 log_debug("Invalid TCP reply packet.");
483 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
487 dns_scope_check_conflicts(t
->scope
, p
);
490 dns_transaction_process_reply(t
, p
);
493 /* If the response wasn't useful, then complete the transition
494 * now. After all, we are the worst feature set now with TCP
495 * sockets, and there's really no point in retrying. */
496 if (t
->state
== DNS_TRANSACTION_PENDING
)
497 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
499 dns_transaction_gc(t
);
504 static int on_stream_complete(DnsStream
*s
, int error
) {
507 if (ERRNO_IS_DISCONNECT(error
) && s
->protocol
!= DNS_PROTOCOL_LLMNR
) {
508 log_debug_errno(error
, "Connection failure for DNS TCP stream: %m");
510 if (s
->transactions
) {
514 dns_server_packet_lost(t
->server
, IPPROTO_TCP
, t
->current_feature_level
);
519 DnsTransaction
*t
, *n
;
521 LIST_FOREACH_SAFE(transactions_by_stream
, t
, n
, s
->transactions
)
522 on_transaction_stream_error(t
, error
);
528 static int on_stream_packet(DnsStream
*s
) {
529 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
534 /* Take ownership of packet to be able to receive new packets */
535 p
= dns_stream_take_read_packet(s
);
538 t
= hashmap_get(s
->manager
->dns_transactions
, UINT_TO_PTR(DNS_PACKET_ID(p
)));
540 return dns_transaction_on_stream_packet(t
, p
);
542 /* Ignore incorrect transaction id as an old transaction can have been canceled. */
543 log_debug("Received unexpected TCP reply packet with id %" PRIu16
", ignoring.", DNS_PACKET_ID(p
));
547 static uint16_t dns_port_for_feature_level(DnsServerFeatureLevel level
) {
548 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(level
) ? 853 : 53;
551 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
552 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
553 _cleanup_close_
int fd
= -1;
554 union sockaddr_union sa
;
560 dns_transaction_close_connection(t
);
562 switch (t
->scope
->protocol
) {
564 case DNS_PROTOCOL_DNS
:
565 r
= dns_transaction_pick_server(t
);
569 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
572 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
576 if (t
->server
->stream
&& (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) == t
->server
->stream
->encrypted
))
577 s
= dns_stream_ref(t
->server
->stream
);
579 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, dns_port_for_feature_level(t
->current_feature_level
), &sa
);
581 type
= DNS_STREAM_LOOKUP
;
584 case DNS_PROTOCOL_LLMNR
:
585 /* When we already received a reply to this (but it was truncated), send to its sender address */
587 fd
= dns_scope_socket_tcp(t
->scope
, t
->received
->family
, &t
->received
->sender
, NULL
, t
->received
->sender_port
, &sa
);
589 union in_addr_union address
;
590 int family
= AF_UNSPEC
;
592 /* Otherwise, try to talk to the owner of a
593 * the IP address, in case this is a reverse
596 r
= dns_name_address(dns_resource_key_name(t
->key
), &family
, &address
);
601 if (family
!= t
->scope
->family
)
604 fd
= dns_scope_socket_tcp(t
->scope
, family
, &address
, NULL
, LLMNR_PORT
, &sa
);
607 type
= DNS_STREAM_LLMNR_SEND
;
611 return -EAFNOSUPPORT
;
618 r
= dns_stream_new(t
->scope
->manager
, &s
, type
, t
->scope
->protocol
, fd
, &sa
);
624 #if ENABLE_DNS_OVER_TLS
625 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
&&
626 DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
)) {
629 r
= dnstls_stream_connect_tls(s
, t
->server
);
636 dns_server_unref_stream(t
->server
);
637 s
->server
= dns_server_ref(t
->server
);
638 t
->server
->stream
= dns_stream_ref(s
);
641 s
->complete
= on_stream_complete
;
642 s
->on_packet
= on_stream_packet
;
644 /* The interface index is difficult to determine if we are
645 * connecting to the local host, hence fill this in right away
646 * instead of determining it from the socket */
647 s
->ifindex
= dns_scope_ifindex(t
->scope
);
650 t
->stream
= TAKE_PTR(s
);
651 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
653 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
655 dns_transaction_close_connection(t
);
659 dns_transaction_reset_answer(t
);
661 t
->tried_stream
= true;
666 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
669 /* For mDNS we cache whenever we get the packet, rather than
670 * in each transaction. */
671 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
674 /* Caching disabled? */
675 if (t
->scope
->manager
->enable_cache
== DNS_CACHE_MODE_NO
)
678 /* We never cache if this packet is from the local host, under
679 * the assumption that a locally running DNS server would
680 * cache this anyway, and probably knows better when to flush
681 * the cache then we could. */
682 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
685 dns_cache_put(&t
->scope
->cache
,
686 t
->scope
->manager
->enable_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 * erroneously 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 failures get reported via ICMP and then are possibly delivered to us on the
1187 * next 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 /* Spurious wakeup without any data */
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 constraints 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
->ifname
: "*",
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 getting 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 additional 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
2148 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2149 * what we are looking for, otherwise there's no value in it for us. */
2150 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2157 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2163 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2167 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2168 t
->id
, dns_resource_key_name(rr
->key
));
2169 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2177 case DNS_TYPE_CNAME
:
2178 case DNS_TYPE_DNAME
: {
2179 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2182 /* CNAMEs and DNAMEs cannot be located at a
2183 * zone apex, hence ask for the parent SOA for
2184 * unsigned CNAME/DNAME RRs, maybe that's the
2185 * apex. But do all that only if this is
2186 * actually a response to our original
2189 * Similar for DS RRs, which are signed when
2190 * the parent SOA is signed. */
2192 r
= dns_transaction_is_primary_response(t
, rr
);
2198 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2204 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2210 name
= dns_resource_key_name(rr
->key
);
2211 r
= dns_name_parent(&name
);
2217 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2221 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2222 t
->id
, dns_resource_key_name(rr
->key
));
2223 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2231 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2233 /* For other unsigned RRsets (including
2234 * NSEC/NSEC3!), look for proof the zone is
2235 * unsigned, by requesting the SOA RR of the
2236 * zone. However, do so only if they are
2237 * directly relevant to our original
2240 r
= dns_transaction_is_primary_response(t
, rr
);
2246 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2252 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2256 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2257 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2258 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2265 /* Above, we requested everything necessary to validate what
2266 * we got. Now, let's request what we need to validate what we
2269 r
= dns_transaction_has_unsigned_negative_answer(t
);
2276 name
= dns_resource_key_name(t
->key
);
2278 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2279 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2280 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2281 * though they have further children. If this was a DS request, then it's signed when the parent zone
2282 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2283 * to see if that is signed. */
2285 if (t
->key
->type
== DNS_TYPE_DS
) {
2286 r
= dns_name_parent(&name
);
2288 type
= DNS_TYPE_SOA
;
2289 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2290 name
, t
->id
, dns_resource_key_name(t
->key
));
2294 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2297 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2301 type
= DNS_TYPE_SOA
;
2302 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2307 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2309 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2313 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2319 return dns_transaction_dnssec_is_live(t
);
2322 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2326 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2327 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2328 the state is VALIDATING however, we should check if we are complete now. */
2330 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2331 dns_transaction_process_dnssec(t
);
2334 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2335 DnsResourceRecord
*rr
;
2340 /* Add all DNSKEY RRs from the answer that are validated by DS
2341 * RRs from the list of validated keys to the list of
2342 * validated keys. */
2344 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2346 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2352 /* If so, the DNSKEY is validated too. */
2353 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2361 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2367 /* Checks if the RR we are looking for must be signed with an
2368 * RRSIG. This is used for positive responses. */
2370 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2373 if (dns_type_is_pseudo(rr
->key
->type
))
2376 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2382 switch (rr
->key
->type
) {
2384 case DNS_TYPE_RRSIG
:
2385 /* RRSIGs are the signatures themselves, they need no signing. */
2393 /* For SOA or NS RRs we look for a matching DS transaction */
2395 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2397 if (dt
->key
->class != rr
->key
->class)
2399 if (dt
->key
->type
!= DNS_TYPE_DS
)
2402 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2408 /* We found a DS transactions for the SOA/NS
2409 * RRs we are looking at. If it discovered signed DS
2410 * RRs, then we need to be signed, too. */
2412 if (!dt
->answer_authenticated
)
2415 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2418 /* We found nothing that proves this is safe to leave
2419 * this unauthenticated, hence ask inist on
2420 * authentication. */
2425 case DNS_TYPE_CNAME
:
2426 case DNS_TYPE_DNAME
: {
2427 const char *parent
= NULL
;
2432 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2434 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2437 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2439 if (dt
->key
->class != rr
->key
->class)
2441 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2445 parent
= dns_resource_key_name(rr
->key
);
2446 r
= dns_name_parent(&parent
);
2450 if (rr
->key
->type
== DNS_TYPE_DS
)
2453 /* A CNAME/DNAME without a parent? That's sooo weird. */
2454 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2455 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2459 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2465 return t
->answer_authenticated
;
2475 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2477 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2479 if (dt
->key
->class != rr
->key
->class)
2481 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2484 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2490 /* We found the transaction that was supposed to find
2491 * the SOA RR for us. It was successful, but found no
2492 * RR for us. This means we are not at a zone cut. In
2493 * this case, we require authentication if the SOA
2494 * lookup was authenticated too. */
2495 return t
->answer_authenticated
;
2502 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2508 /* If DNSSEC downgrade mode is on, checks whether the
2509 * specified RR is one level below a TLD we have proven not to
2510 * exist. In such a case we assume that this is a private
2511 * domain, and permit it.
2513 * This detects cases like the Fritz!Box router networks. Each
2514 * Fritz!Box router serves a private "fritz.box" zone, in the
2515 * non-existing TLD "box". Requests for the "fritz.box" domain
2516 * are served by the router itself, while requests for the
2517 * "box" domain will result in NXDOMAIN.
2519 * Note that this logic is unable to detect cases where a
2520 * router serves a private DNS zone directly under
2521 * non-existing TLD. In such a case we cannot detect whether
2522 * the TLD is supposed to exist or not, as all requests we
2523 * make for it will be answered by the router's zone, and not
2524 * by the root zone. */
2528 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2529 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2531 tld
= dns_resource_key_name(key
);
2532 r
= dns_name_parent(&tld
);
2536 return false; /* Already the root domain */
2538 if (!dns_name_is_single_label(tld
))
2541 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2543 if (dt
->key
->class != key
->class)
2546 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2552 /* We found an auxiliary lookup we did for the TLD. If
2553 * that returned with NXDOMAIN, we know the TLD didn't
2554 * exist, and hence this might be a private zone. */
2556 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2562 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2563 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2572 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2573 * this negative reply */
2575 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2578 if (dns_type_is_pseudo(t
->key
->type
))
2581 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2587 r
= dns_transaction_in_private_tld(t
, t
->key
);
2591 /* The lookup is from a TLD that is proven not to
2592 * exist, and we are in downgrade mode, hence ignore
2593 * that fact that we didn't get any NSEC RRs. */
2595 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2596 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2600 name
= dns_resource_key_name(t
->key
);
2602 if (t
->key
->type
== DNS_TYPE_DS
) {
2604 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2605 * hence check the parent SOA in this case. */
2607 r
= dns_name_parent(&name
);
2613 type
= DNS_TYPE_SOA
;
2615 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2616 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2619 /* For all other negative replies, check for the SOA lookup */
2620 type
= DNS_TYPE_SOA
;
2622 /* For all other RRs we check the SOA on the same level to see
2623 * if it's signed. */
2625 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2627 if (dt
->key
->class != t
->key
->class)
2629 if (dt
->key
->type
!= type
)
2632 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2638 return dt
->answer_authenticated
;
2641 /* If in doubt, require NSEC/NSEC3 */
2645 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2646 DnsResourceRecord
*rrsig
;
2650 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2651 * the specified RRset is authenticated (i.e. has a matching
2654 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2660 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2664 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2670 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2672 if (dt
->key
->class != rr
->key
->class)
2675 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2677 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2683 /* OK, we found an auxiliary DNSKEY
2684 * lookup. If that lookup is
2685 * authenticated, report this. */
2687 if (dt
->answer_authenticated
)
2692 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2694 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2700 /* OK, we found an auxiliary DS
2701 * lookup. If that lookup is
2702 * authenticated and non-zero, we
2705 if (!dt
->answer_authenticated
)
2708 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2713 return found
? false : -ENXIO
;
2716 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2720 /* We know that the root domain is signed, hence if it appears
2721 * not to be signed, there's a problem with the DNS server */
2723 return rr
->key
->class == DNS_CLASS_IN
&&
2724 dns_name_is_root(dns_resource_key_name(rr
->key
));
2727 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2728 DnsResourceRecord
*rr
;
2733 /* Maybe warn the user that we encountered a revoked DNSKEY
2734 * for a key from our trust anchor. Note that we don't care
2735 * whether the DNSKEY can be authenticated or not. It's
2736 * sufficient if it is self-signed. */
2738 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2739 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2747 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2753 /* Removes all DNSKEY/DS objects from t->validated_keys that
2754 * our trust anchors database considers revoked. */
2757 DnsResourceRecord
*rr
;
2761 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2762 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2766 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2780 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2787 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2789 SET_FOREACH(dt
, t
->dnssec_transactions
, i
) {
2791 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2794 if (!dt
->answer_authenticated
)
2797 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2806 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2807 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2808 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2811 static int dnssec_validate_records(
2815 DnsAnswer
**validated
) {
2817 DnsResourceRecord
*rr
;
2820 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2822 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2823 DnsResourceRecord
*rrsig
= NULL
;
2824 DnssecResult result
;
2826 switch (rr
->key
->type
) {
2827 case DNS_TYPE_RRSIG
:
2830 case DNS_TYPE_DNSKEY
:
2831 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2832 if (phase
== DNSSEC_PHASE_NSEC
)
2837 case DNS_TYPE_NSEC3
:
2840 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2841 if (phase
== DNSSEC_PHASE_DNSKEY
)
2846 /* We validate all other RRs only in the ALL phases */
2847 if (phase
!= DNSSEC_PHASE_ALL
)
2851 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2855 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2857 if (result
== DNSSEC_VALIDATED
) {
2859 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2860 /* If we just validated a DNSKEY RRset, then let's add these keys to
2861 * the set of validated keys for this transaction. */
2863 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2867 /* Some of the DNSKEYs we just added might already have been revoked,
2868 * remove them again in that case. */
2869 r
= dns_transaction_invalidate_revoked_keys(t
);
2874 /* Add the validated RRset to the new list of validated
2875 * RRsets, and remove it from the unvalidated RRsets.
2876 * We mark the RRset as authenticated and cacheable. */
2877 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2881 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2883 /* Exit the loop, we dropped something from the answer, start from the beginning */
2887 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2888 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2889 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2890 if (phase
!= DNSSEC_PHASE_ALL
)
2893 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2894 bool authenticated
= false;
2897 /* This RRset validated, but as a wildcard. This means we need
2898 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2900 /* First step, determine the source of synthesis */
2901 r
= dns_resource_record_source(rrsig
, &source
);
2905 r
= dnssec_test_positive_wildcard(*validated
,
2906 dns_resource_key_name(rr
->key
),
2908 rrsig
->rrsig
.signer
,
2911 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2913 result
= DNSSEC_INVALID
;
2915 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2916 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2920 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2922 /* Exit the loop, we dropped something from the answer, start from the beginning */
2927 if (result
== DNSSEC_NO_SIGNATURE
) {
2928 r
= dns_transaction_requires_rrsig(t
, rr
);
2932 /* Data does not require signing. In that case, just copy it over,
2933 * but remember that this is by no means authenticated. */
2934 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2938 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2942 r
= dns_transaction_known_signed(t
, rr
);
2946 /* This is an RR we know has to be signed. If it isn't this means
2947 * the server is not attaching RRSIGs, hence complain. */
2949 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2951 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2953 /* Downgrading is OK? If so, just consider the information unsigned */
2955 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2959 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2963 /* Otherwise, fail */
2964 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2968 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2972 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2974 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2975 * mode, hence ignore the fact that this was not signed. */
2977 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2978 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2980 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2984 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2991 DNSSEC_SIGNATURE_EXPIRED
,
2992 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2994 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2995 if (r
< 0 && r
!= -ENXIO
)
2998 /* The DNSKEY transaction was not authenticated, this means there's
2999 * no DS for this, which means it's OK if no keys are found for this signature. */
3001 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
3005 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
3010 r
= dns_transaction_is_primary_response(t
, rr
);
3014 /* Look for a matching DNAME for this CNAME */
3015 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
3019 /* Also look among the stuff we already validated */
3020 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3028 DNSSEC_SIGNATURE_EXPIRED
,
3029 DNSSEC_NO_SIGNATURE
))
3030 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3031 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3032 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3034 /* This is a primary response to our question, and it failed validation.
3036 t
->answer_dnssec_result
= result
;
3040 /* This is a primary response, but we do have a DNAME RR
3041 * in the RR that can replay this CNAME, hence rely on
3042 * that, and we can remove the CNAME in favour of it. */
3045 /* This is just some auxiliary data. Just remove the RRset and continue. */
3046 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3050 /* We dropped something from the answer, start from the beginning. */
3054 return 2; /* Finito. */
3057 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3058 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3060 DnsAnswerFlags flags
;
3062 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3066 /* We have now collected all DS and DNSKEY RRs in
3067 * t->validated_keys, let's see which RRs we can now
3068 * authenticate with that. */
3070 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3073 /* Already validated */
3074 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3077 /* Our own stuff needs no validation */
3078 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3079 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3080 t
->answer_authenticated
= true;
3084 /* Cached stuff is not affected by validation. */
3085 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3088 if (!dns_transaction_dnssec_supported_full(t
)) {
3089 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3090 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3091 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3095 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3097 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3099 /* First, see if this response contains any revoked trust
3100 * anchors we care about */
3101 r
= dns_transaction_check_revoked_trust_anchors(t
);
3105 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3106 r
= dns_transaction_copy_validated(t
);
3110 /* Second, see if there are DNSKEYs we already know a
3111 * validated DS for. */
3112 r
= dns_transaction_validate_dnskey_by_ds(t
);
3116 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3117 * anchor says are revoked. After all we might have marked
3118 * some keys revoked above, but they might still be lingering
3119 * in our validated_keys list. */
3120 r
= dns_transaction_invalidate_revoked_keys(t
);
3124 phase
= DNSSEC_PHASE_DNSKEY
;
3126 bool have_nsec
= false;
3128 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3132 /* Try again as long as we managed to achieve something */
3136 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3137 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3138 phase
= DNSSEC_PHASE_NSEC
;
3142 if (phase
!= DNSSEC_PHASE_ALL
) {
3143 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3144 * Note that in this third phase we start to remove RRs we couldn't validate. */
3145 phase
= DNSSEC_PHASE_ALL
;
3153 dns_answer_unref(t
->answer
);
3154 t
->answer
= TAKE_PTR(validated
);
3156 /* At this point the answer only contains validated
3157 * RRsets. Now, let's see if it actually answers the question
3158 * we asked. If so, great! If it doesn't, then see if
3159 * NSEC/NSEC3 can prove this. */
3160 r
= dns_transaction_has_positive_answer(t
, &flags
);
3162 /* Yes, it answers the question! */
3164 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3165 /* The answer is fully authenticated, yay. */
3166 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3167 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3168 t
->answer_authenticated
= true;
3170 /* The answer is not fully authenticated. */
3171 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3172 t
->answer_authenticated
= false;
3175 } else if (r
== 0) {
3176 DnssecNsecResult nr
;
3177 bool authenticated
= false;
3179 /* Bummer! Let's check NSEC/NSEC3 */
3180 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3186 case DNSSEC_NSEC_NXDOMAIN
:
3187 /* NSEC proves the domain doesn't exist. Very good. */
3188 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3189 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3190 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3191 t
->answer_authenticated
= authenticated
;
3193 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3196 case DNSSEC_NSEC_NODATA
:
3197 /* NSEC proves that there's no data here, very good. */
3198 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3199 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3200 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3201 t
->answer_authenticated
= authenticated
;
3203 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3206 case DNSSEC_NSEC_OPTOUT
:
3207 /* NSEC3 says the data might not be signed */
3208 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3209 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3210 t
->answer_authenticated
= false;
3212 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3215 case DNSSEC_NSEC_NO_RR
:
3216 /* No NSEC data? Bummer! */
3218 r
= dns_transaction_requires_nsec(t
);
3222 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3223 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3225 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3226 t
->answer_authenticated
= false;
3227 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3232 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3233 /* We don't know the NSEC3 algorithm used? */
3234 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3235 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3238 case DNSSEC_NSEC_FOUND
:
3239 case DNSSEC_NSEC_CNAME
:
3240 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3241 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3242 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3246 assert_not_reached("Unexpected NSEC result.");
3253 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3254 [DNS_TRANSACTION_NULL
] = "null",
3255 [DNS_TRANSACTION_PENDING
] = "pending",
3256 [DNS_TRANSACTION_VALIDATING
] = "validating",
3257 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3258 [DNS_TRANSACTION_SUCCESS
] = "success",
3259 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3260 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3261 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3262 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3263 [DNS_TRANSACTION_ERRNO
] = "errno",
3264 [DNS_TRANSACTION_ABORTED
] = "aborted",
3265 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3266 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3267 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3268 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3269 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3271 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3273 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3274 [DNS_TRANSACTION_NETWORK
] = "network",
3275 [DNS_TRANSACTION_CACHE
] = "cache",
3276 [DNS_TRANSACTION_ZONE
] = "zone",
3277 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3279 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);