1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
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
= new(DnsTransaction
, 1);
201 *t
= (DnsTransaction
) {
203 .answer_source
= _DNS_TRANSACTION_SOURCE_INVALID
,
204 .answer_dnssec_result
= _DNSSEC_RESULT_INVALID
,
205 .answer_nsec_ttl
= (uint32_t) -1,
206 .key
= dns_resource_key_ref(key
),
207 .current_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
,
208 .clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
,
209 .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
->ifname
: "*",
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", strna(dns_server_string_full(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
->ifname
: "*",
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 void dns_transaction_complete_errno(DnsTransaction
*t
, int error
) {
372 t
->answer_errno
= abs(error
);
373 dns_transaction_complete(t
, DNS_TRANSACTION_ERRNO
);
376 static int dns_transaction_pick_server(DnsTransaction
*t
) {
380 assert(t
->scope
->protocol
== DNS_PROTOCOL_DNS
);
382 /* Pick a DNS server and a feature level for it. */
384 server
= dns_scope_get_dns_server(t
->scope
);
388 /* If we changed the server invalidate the feature level clamping, as the new server might have completely
389 * different properties. */
390 if (server
!= t
->server
)
391 t
->clamp_feature_level
= _DNS_SERVER_FEATURE_LEVEL_INVALID
;
393 t
->current_feature_level
= dns_server_possible_feature_level(server
);
395 /* Clamp the feature level if that is requested. */
396 if (t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
&&
397 t
->current_feature_level
> t
->clamp_feature_level
)
398 t
->current_feature_level
= t
->clamp_feature_level
;
400 log_debug("Using feature level %s for transaction %u.", dns_server_feature_level_to_string(t
->current_feature_level
), t
->id
);
402 if (server
== t
->server
)
405 dns_server_unref(t
->server
);
406 t
->server
= dns_server_ref(server
);
408 t
->n_picked_servers
++;
410 log_debug("Using DNS server %s for transaction %u.", strna(dns_server_string_full(t
->server
)), t
->id
);
415 static void dns_transaction_retry(DnsTransaction
*t
, bool next_server
) {
420 log_debug("Retrying transaction %" PRIu16
".", t
->id
);
422 /* Before we try again, switch to a new server. */
424 dns_scope_next_dns_server(t
->scope
);
426 r
= dns_transaction_go(t
);
428 dns_transaction_complete_errno(t
, r
);
431 static int dns_transaction_maybe_restart(DnsTransaction
*t
) {
436 /* Returns > 0 if the transaction was restarted, 0 if not */
441 if (t
->current_feature_level
<= dns_server_possible_feature_level(t
->server
))
444 /* The server's current feature level is lower than when we sent the original query. We learnt something from
445 the response or possibly an auxiliary DNSSEC response that we didn't know before. We take that as reason to
446 restart the whole transaction. This is a good idea to deal with servers that respond rubbish if we include
447 OPT RR or DO bit. One of these cases is documented here, for example:
448 https://open.nlnetlabs.nl/pipermail/dnssec-trigger/2014-November/000376.html */
450 log_debug("Server feature level is now lower than when we began our transaction. Restarting with new ID.");
451 dns_transaction_shuffle_id(t
);
453 r
= dns_transaction_go(t
);
460 static void on_transaction_stream_error(DnsTransaction
*t
, int error
) {
463 dns_transaction_close_connection(t
);
465 if (ERRNO_IS_DISCONNECT(error
)) {
466 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
) {
467 /* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
468 * question on this scope. */
469 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
473 dns_transaction_retry(t
, true);
477 dns_transaction_complete_errno(t
, error
);
480 static int dns_transaction_on_stream_packet(DnsTransaction
*t
, DnsPacket
*p
) {
484 dns_transaction_close_connection(t
);
486 if (dns_packet_validate_reply(p
) <= 0) {
487 log_debug("Invalid TCP reply packet.");
488 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
492 dns_scope_check_conflicts(t
->scope
, p
);
495 dns_transaction_process_reply(t
, p
);
498 /* If the response wasn't useful, then complete the transition
499 * now. After all, we are the worst feature set now with TCP
500 * sockets, and there's really no point in retrying. */
501 if (t
->state
== DNS_TRANSACTION_PENDING
)
502 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
504 dns_transaction_gc(t
);
509 static int on_stream_complete(DnsStream
*s
, int error
) {
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 an old transaction can have been canceled. */
548 log_debug("Received unexpected TCP reply packet with id %" PRIu16
", ignoring.", DNS_PACKET_ID(p
));
552 static uint16_t dns_transaction_port(DnsTransaction
*t
) {
553 if (t
->server
->port
> 0)
554 return t
->server
->port
;
555 return DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) ? 853 : 53;
558 static int dns_transaction_emit_tcp(DnsTransaction
*t
) {
559 _cleanup_(dns_stream_unrefp
) DnsStream
*s
= NULL
;
560 _cleanup_close_
int fd
= -1;
561 union sockaddr_union sa
;
567 dns_transaction_close_connection(t
);
569 switch (t
->scope
->protocol
) {
571 case DNS_PROTOCOL_DNS
:
572 r
= dns_transaction_pick_server(t
);
576 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
579 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
583 if (t
->server
->stream
&& (DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
) == t
->server
->stream
->encrypted
))
584 s
= dns_stream_ref(t
->server
->stream
);
586 fd
= dns_scope_socket_tcp(t
->scope
, AF_UNSPEC
, NULL
, t
->server
, dns_transaction_port(t
), &sa
);
588 type
= DNS_STREAM_LOOKUP
;
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
);
614 type
= DNS_STREAM_LLMNR_SEND
;
618 return -EAFNOSUPPORT
;
625 r
= dns_stream_new(t
->scope
->manager
, &s
, type
, t
->scope
->protocol
, fd
, &sa
);
631 #if ENABLE_DNS_OVER_TLS
632 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
&&
633 DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
)) {
636 r
= dnstls_stream_connect_tls(s
, t
->server
);
643 dns_server_unref_stream(t
->server
);
644 s
->server
= dns_server_ref(t
->server
);
645 t
->server
->stream
= dns_stream_ref(s
);
648 s
->complete
= on_stream_complete
;
649 s
->on_packet
= on_stream_packet
;
651 /* The interface index is difficult to determine if we are
652 * connecting to the local host, hence fill this in right away
653 * instead of determining it from the socket */
654 s
->ifindex
= dns_scope_ifindex(t
->scope
);
657 t
->stream
= TAKE_PTR(s
);
658 LIST_PREPEND(transactions_by_stream
, t
->stream
->transactions
, t
);
660 r
= dns_stream_write_packet(t
->stream
, t
->sent
);
662 dns_transaction_close_connection(t
);
666 dns_transaction_reset_answer(t
);
668 t
->tried_stream
= true;
673 static void dns_transaction_cache_answer(DnsTransaction
*t
) {
676 /* For mDNS we cache whenever we get the packet, rather than
677 * in each transaction. */
678 if (!IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_DNS
, DNS_PROTOCOL_LLMNR
))
681 /* Caching disabled? */
682 if (t
->scope
->manager
->enable_cache
== DNS_CACHE_MODE_NO
)
685 /* We never cache if this packet is from the local host, under
686 * the assumption that a locally running DNS server would
687 * cache this anyway, and probably knows better when to flush
688 * the cache then we could. */
689 if (!DNS_PACKET_SHALL_CACHE(t
->received
))
692 dns_cache_put(&t
->scope
->cache
,
693 t
->scope
->manager
->enable_cache
,
697 t
->answer_authenticated
,
701 &t
->received
->sender
);
704 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
709 SET_FOREACH(dt
, t
->dnssec_transactions
)
710 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
716 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
721 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
722 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
724 SET_FOREACH(dt
, t
->dnssec_transactions
) {
728 case DNS_TRANSACTION_NULL
:
729 case DNS_TRANSACTION_PENDING
:
730 case DNS_TRANSACTION_VALIDATING
:
734 case DNS_TRANSACTION_RCODE_FAILURE
:
735 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
736 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
740 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
741 * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
742 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
743 * RRs to make unsigned proofs. */
745 case DNS_TRANSACTION_SUCCESS
:
749 case DNS_TRANSACTION_DNSSEC_FAILED
:
750 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
751 * validationr result */
753 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
754 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
755 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
759 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
764 /* All is ready, we can go and validate */
768 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
769 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
773 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
778 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
779 r
= dns_transaction_dnssec_ready(t
);
782 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
785 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
786 * restart the lookup immediately. */
787 r
= dns_transaction_maybe_restart(t
);
790 if (r
> 0) /* Transaction got restarted... */
793 /* All our auxiliary DNSSEC transactions are complete now. Try
794 * to validate our RRset now. */
795 r
= dns_transaction_validate_dnssec(t
);
797 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
803 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
804 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
806 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
809 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
810 /* We tried fewer servers on this transaction than we know, let's try another one then */
811 dns_transaction_retry(t
, true);
815 /* OK, let's give up, apparently all servers we tried didn't work. */
816 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
820 if (!IN_SET(t
->answer_dnssec_result
,
821 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
822 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
823 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
824 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
825 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
829 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
830 dns_server_warn_downgrade(t
->server
);
832 dns_transaction_cache_answer(t
);
834 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
835 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
837 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
842 dns_transaction_complete_errno(t
, r
);
845 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
850 /* Checks whether the answer is positive, i.e. either a direct
851 * answer to the question, or a CNAME/DNAME for it */
853 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
857 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
864 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
869 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
870 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
871 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
872 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
873 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
874 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
875 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
876 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
877 * incomplete CNAME/DNAME chain.
879 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
880 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
883 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
886 r
= dns_transaction_has_positive_answer(t
, NULL
);
890 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
894 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
901 assert(t
->scope
->manager
);
903 if (t
->state
!= DNS_TRANSACTION_PENDING
)
906 /* Note that this call might invalidate the query. Callers
907 * should hence not attempt to access the query or transaction
908 * after calling this function. */
910 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
911 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
913 switch (t
->scope
->protocol
) {
915 case DNS_PROTOCOL_LLMNR
:
916 /* For LLMNR we will not accept any packets from other interfaces */
918 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
921 if (p
->family
!= t
->scope
->family
)
924 /* Tentative packets are not full responses but still
925 * useful for identifying uniqueness conflicts during
927 if (DNS_PACKET_LLMNR_T(p
)) {
928 dns_transaction_tentative(t
, p
);
934 case DNS_PROTOCOL_MDNS
:
935 /* For mDNS we will not accept any packets from other interfaces */
937 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
940 if (p
->family
!= t
->scope
->family
)
945 case DNS_PROTOCOL_DNS
:
946 /* Note that we do not need to verify the
947 * addresses/port numbers of incoming traffic, as we
948 * invoked connect() on our UDP socket in which case
949 * the kernel already does the needed verification for
954 assert_not_reached("Invalid DNS protocol.");
957 if (t
->received
!= p
) {
958 dns_packet_unref(t
->received
);
959 t
->received
= dns_packet_ref(p
);
962 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
964 if (p
->ipproto
== IPPROTO_TCP
) {
965 if (DNS_PACKET_TC(p
)) {
966 /* Truncated via TCP? Somebody must be fucking with us */
967 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
971 if (DNS_PACKET_ID(p
) != t
->id
) {
972 /* Not the reply to our query? Somebody must be fucking with us */
973 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
978 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
980 switch (t
->scope
->protocol
) {
982 case DNS_PROTOCOL_DNS
:
985 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
987 /* Request failed, immediately try again with reduced features */
989 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
991 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
992 * this transaction anymore, but let's see if it might make sense to send the request
993 * to a different DNS server instead. If not let's process the response, and accept the
994 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
995 * packet loss, but is not going to give us better rcodes should we actually have
996 * managed to get them already at UDP level. */
998 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
999 /* We tried fewer servers on this transaction than we know, let's try another one then */
1000 dns_transaction_retry(t
, true);
1004 /* Give up, accept the rcode */
1005 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1009 /* Reduce this feature level by one and try again. */
1010 switch (t
->current_feature_level
) {
1011 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1012 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1014 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1015 /* Skip plain TLS when TLS is not supported */
1016 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1019 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1022 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1023 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1024 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1026 dns_transaction_retry(t
, false /* use the same server */);
1030 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1031 /* This server refused our request? If so, try again, use a different server */
1032 log_debug("Server returned REFUSED, switching servers, and retrying.");
1033 dns_transaction_retry(t
, true /* pick a new server */);
1037 if (DNS_PACKET_TC(p
))
1038 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1042 case DNS_PROTOCOL_LLMNR
:
1043 case DNS_PROTOCOL_MDNS
:
1044 dns_scope_packet_received(t
->scope
, ts
- t
->start_usec
);
1048 assert_not_reached("Invalid DNS protocol.");
1051 if (DNS_PACKET_TC(p
)) {
1053 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1054 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1055 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1059 log_debug("Reply truncated, retrying via TCP.");
1061 /* Response was truncated, let's try again with good old TCP */
1062 r
= dns_transaction_emit_tcp(t
);
1064 /* No servers found? Damn! */
1065 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1068 if (r
== -EOPNOTSUPP
) {
1069 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1070 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1074 /* On LLMNR, if we cannot connect to the host,
1075 * we immediately give up */
1076 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1079 /* On DNS, couldn't send? Try immediately again, with a new server */
1080 dns_transaction_retry(t
, true);
1086 /* After the superficial checks, actually parse the message. */
1087 r
= dns_packet_extract(p
);
1089 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1094 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1095 * rcode and subsequently downgraded the protocol */
1097 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1098 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1099 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1101 /* Report that the OPT RR was missing */
1103 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1105 /* Report that we successfully received a packet */
1106 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1109 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1110 r
= dns_transaction_maybe_restart(t
);
1113 if (r
> 0) /* Transaction got restarted... */
1116 /* When dealing with protocols other than mDNS only consider responses with equivalent query section
1117 * to the request. For mDNS this check doesn't make sense, because the section 6 of RFC6762 states
1118 * that "Multicast DNS responses MUST NOT contain any questions in the Question Section". */
1119 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1120 r
= dns_packet_is_reply_for(p
, t
->key
);
1124 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1129 /* Install the answer as answer to the transaction */
1130 dns_answer_unref(t
->answer
);
1131 t
->answer
= dns_answer_ref(p
->answer
);
1132 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1133 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1134 t
->answer_authenticated
= false;
1136 r
= dns_transaction_fix_rcode(t
);
1140 /* Block GC while starting requests for additional DNSSEC RRs */
1142 r
= dns_transaction_request_dnssec_keys(t
);
1145 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1146 if (!dns_transaction_gc(t
))
1149 /* Requesting additional keys might have resulted in this transaction to fail, since the auxiliary
1150 * request failed for some reason. If so, we are not in pending state anymore, and we should exit
1152 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1157 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1158 t
->state
= DNS_TRANSACTION_VALIDATING
;
1159 dns_transaction_close_connection(t
);
1160 dns_transaction_stop_timeout(t
);
1164 dns_transaction_process_dnssec(t
);
1168 dns_transaction_complete_errno(t
, r
);
1171 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1172 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1173 DnsTransaction
*t
= userdata
;
1179 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1180 if (ERRNO_IS_DISCONNECT(r
)) {
1183 /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the
1184 * next recvmsg(). Treat this like a lost packet. */
1186 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1187 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1188 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1190 dns_transaction_retry(t
, true);
1194 dns_transaction_complete_errno(t
, r
);
1198 /* Spurious wakeup without any data */
1201 r
= dns_packet_validate_reply(p
);
1203 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1207 log_debug("Received inappropriate DNS packet as response, ignoring.");
1211 if (DNS_PACKET_ID(p
) != t
->id
) {
1212 log_debug("Received packet with incorrect transaction ID, ignoring.");
1216 dns_transaction_process_reply(t
, p
);
1220 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1225 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1227 r
= dns_transaction_pick_server(t
);
1231 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1232 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1234 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1237 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1240 dns_transaction_close_connection(t
);
1242 fd
= dns_scope_socket_udp(t
->scope
, t
->server
);
1246 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1252 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1256 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1260 dns_transaction_close_connection(t
);
1262 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1266 dns_transaction_reset_answer(t
);
1271 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1272 DnsTransaction
*t
= userdata
;
1277 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1278 /* Timeout reached? Increase the timeout for the server used */
1279 switch (t
->scope
->protocol
) {
1281 case DNS_PROTOCOL_DNS
:
1283 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1286 case DNS_PROTOCOL_LLMNR
:
1287 case DNS_PROTOCOL_MDNS
:
1288 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1292 assert_not_reached("Invalid DNS protocol.");
1295 if (t
->initial_jitter_scheduled
)
1296 t
->initial_jitter_elapsed
= true;
1299 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1301 dns_transaction_retry(t
, true);
1305 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1309 switch (t
->scope
->protocol
) {
1311 case DNS_PROTOCOL_DNS
:
1313 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1314 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1317 return TRANSACTION_TCP_TIMEOUT_USEC
;
1319 return DNS_TIMEOUT_USEC
;
1321 case DNS_PROTOCOL_MDNS
:
1322 assert(t
->n_attempts
> 0);
1324 return MDNS_PROBING_INTERVAL_USEC
;
1326 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1328 case DNS_PROTOCOL_LLMNR
:
1329 return t
->scope
->resend_timeout
;
1332 assert_not_reached("Invalid DNS protocol.");
1336 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1341 dns_transaction_stop_timeout(t
);
1343 if (!dns_scope_network_good(t
->scope
)) {
1344 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1348 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1349 DnsTransactionState result
;
1351 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
)
1352 /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve
1354 result
= DNS_TRANSACTION_NOT_FOUND
;
1356 result
= DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
;
1358 dns_transaction_complete(t
, result
);
1362 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1363 /* If we already tried via a stream, then we don't
1364 * retry on LLMNR. See RFC 4795, Section 2.7. */
1365 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1372 dns_transaction_reset_answer(t
);
1373 dns_transaction_flush_dnssec_transactions(t
);
1375 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1376 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1377 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1381 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1382 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1383 t
->answer_authenticated
= true;
1384 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1388 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1389 t
->key
->type
== DNS_TYPE_DS
) {
1391 /* Hmm, this is a request for the root DS? A
1392 * DS RR doesn't exist in the root zone, and
1393 * if our trust anchor didn't know it either,
1394 * this means we cannot do any DNSSEC logic
1397 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1398 /* We are in downgrade mode. In this
1399 * case, synthesize an unsigned empty
1400 * response, so that the any lookup
1401 * depending on this one can continue
1402 * assuming there was no DS, and hence
1403 * the root zone was unsigned. */
1405 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1406 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1407 t
->answer_authenticated
= false;
1408 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1410 /* If we are not in downgrade mode,
1411 * then fail the lookup, because we
1412 * cannot reasonably answer it. There
1413 * might be DS RRs, but we don't know
1414 * them, and the DNS server won't tell
1415 * them to us (and even if it would,
1416 * we couldn't validate and trust them. */
1417 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1423 /* Check the zone, but only if this transaction is not used
1424 * for probing or verifying a zone item. */
1425 if (set_isempty(t
->notify_zone_items
)) {
1427 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1431 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1432 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1433 t
->answer_authenticated
= true;
1434 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1439 /* Check the cache, but only if this transaction is not used
1440 * for probing or verifying a zone item. */
1441 if (set_isempty(t
->notify_zone_items
)) {
1443 /* Before trying the cache, let's make sure we figured out a
1444 * server to use. Should this cause a change of server this
1445 * might flush the cache. */
1446 (void) dns_scope_get_dns_server(t
->scope
);
1448 /* Let's then prune all outdated entries */
1449 dns_cache_prune(&t
->scope
->cache
);
1451 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1455 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1456 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1457 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1459 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1467 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1469 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1470 bool add_known_answers
= false;
1471 DnsTransaction
*other
;
1472 DnsResourceKey
*tkey
;
1473 _cleanup_set_free_ Set
*keys
= NULL
;
1475 unsigned nscount
= 0;
1480 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1482 /* Discard any previously prepared packet, so we can start over and coalesce again */
1483 t
->sent
= dns_packet_unref(t
->sent
);
1485 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1489 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1495 if (dns_key_is_shared(t
->key
))
1496 add_known_answers
= true;
1498 if (t
->key
->type
== DNS_TYPE_ANY
) {
1499 r
= set_ensure_put(&keys
, &dns_resource_key_hash_ops
, 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_put(&keys
, &dns_resource_key_hash_ops
, other
->key
);
1571 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1573 /* Append known answer section if we're asking for any shared record */
1574 if (add_known_answers
) {
1575 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1580 SET_FOREACH(tkey
, keys
) {
1581 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1584 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1588 r
= dns_packet_append_answer(p
, answer
);
1592 nscount
+= dns_answer_size(answer
);
1594 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1596 t
->sent
= TAKE_PTR(p
);
1601 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1602 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1607 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1608 return dns_transaction_make_packet_mdns(t
);
1613 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1617 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1621 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1622 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1624 t
->sent
= TAKE_PTR(p
);
1629 int dns_transaction_go(DnsTransaction
*t
) {
1632 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1636 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has finished
1639 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1641 r
= dns_transaction_prepare(t
, ts
);
1645 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1647 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1648 dns_protocol_to_string(t
->scope
->protocol
),
1649 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
1650 af_to_name_short(t
->scope
->family
));
1652 if (!t
->initial_jitter_scheduled
&&
1653 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1654 usec_t jitter
, accuracy
;
1656 /* RFC 4795 Section 2.7 suggests all queries should be
1657 * delayed by a random time from 0 to JITTER_INTERVAL. */
1659 t
->initial_jitter_scheduled
= true;
1661 random_bytes(&jitter
, sizeof(jitter
));
1663 switch (t
->scope
->protocol
) {
1665 case DNS_PROTOCOL_LLMNR
:
1666 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1667 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1670 case DNS_PROTOCOL_MDNS
:
1671 jitter
%= MDNS_JITTER_RANGE_USEC
;
1672 jitter
+= MDNS_JITTER_MIN_USEC
;
1673 accuracy
= MDNS_JITTER_RANGE_USEC
;
1676 assert_not_reached("bad protocol");
1679 r
= sd_event_add_time(
1680 t
->scope
->manager
->event
,
1681 &t
->timeout_event_source
,
1682 clock_boottime_or_monotonic(),
1683 ts
+ jitter
, accuracy
,
1684 on_transaction_timeout
, t
);
1688 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1691 t
->next_attempt_after
= ts
;
1692 t
->state
= DNS_TRANSACTION_PENDING
;
1694 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1698 /* Otherwise, we need to ask the network */
1699 r
= dns_transaction_make_packet(t
);
1703 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1704 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1705 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1707 /* RFC 4795, Section 2.4. says reverse lookups shall
1708 * always be made via TCP on LLMNR */
1709 r
= dns_transaction_emit_tcp(t
);
1711 /* Try via UDP, and if that fails due to large size or lack of
1712 * support try via TCP */
1713 r
= dns_transaction_emit_udp(t
);
1715 log_debug("Sending query via TCP since it is too large.");
1716 else if (r
== -EAGAIN
)
1717 log_debug("Sending query via TCP since UDP isn't supported.");
1718 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1719 r
= dns_transaction_emit_tcp(t
);
1723 /* No servers to send this to? */
1724 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1727 if (r
== -EOPNOTSUPP
) {
1728 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1729 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1732 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(r
)) {
1733 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1734 * answer this request with this protocol. */
1735 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1739 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1742 /* Couldn't send? Try immediately again, with a new server */
1743 dns_scope_next_dns_server(t
->scope
);
1745 return dns_transaction_go(t
);
1748 ts
+= transaction_get_resend_timeout(t
);
1750 r
= sd_event_add_time(
1751 t
->scope
->manager
->event
,
1752 &t
->timeout_event_source
,
1753 clock_boottime_or_monotonic(),
1755 on_transaction_timeout
, t
);
1759 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1761 t
->state
= DNS_TRANSACTION_PENDING
;
1762 t
->next_attempt_after
= ts
;
1767 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1774 /* Try to find cyclic dependencies between transaction objects */
1779 SET_FOREACH(n
, aux
->dnssec_transactions
) {
1780 r
= dns_transaction_find_cyclic(t
, n
);
1788 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1789 _cleanup_(dns_transaction_gcp
) DnsTransaction
*aux
= NULL
;
1796 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1798 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1802 if (set_contains(t
->dnssec_transactions
, aux
)) {
1807 r
= dns_transaction_find_cyclic(t
, aux
);
1811 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1813 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1814 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1816 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1818 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1822 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1826 r
= set_ensure_put(&t
->dnssec_transactions
, NULL
, aux
);
1830 r
= set_ensure_put(&aux
->notify_transactions
, NULL
, t
);
1832 (void) set_remove(t
->dnssec_transactions
, aux
);
1836 *ret
= TAKE_PTR(aux
);
1840 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1841 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1842 DnsTransaction
*aux
;
1848 /* Try to get the data from the trust anchor */
1849 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1853 r
= dns_answer_extend(&t
->validated_keys
, a
);
1860 /* This didn't work, ask for it via the network/cache then. */
1861 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1862 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1867 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1868 r
= dns_transaction_go(aux
);
1876 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1881 /* Check whether the specified name is in the NTA
1882 * database, either in the global one, or the link-local
1885 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1889 if (!t
->scope
->link
)
1892 return set_contains(t
->scope
->link
->dnssec_negative_trust_anchors
, name
);
1895 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1900 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1901 * RRs to prove it */
1903 r
= dns_transaction_has_positive_answer(t
, NULL
);
1909 /* Is this key explicitly listed as a negative trust anchor?
1910 * If so, it's nothing we need to care about */
1911 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1917 /* The answer does not contain any RRs that match to the
1918 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1919 * included. If not, the answer is unsigned. */
1921 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1930 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1936 /* Check if the specified RR is the "primary" response,
1937 * i.e. either matches the question precisely or is a
1938 * CNAME/DNAME for it. */
1940 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1944 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1947 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1950 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1951 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1953 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1956 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1957 * be supported, hence return true. */
1961 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1962 * the server is known to support currently, as the transaction feature level might be lower than what the
1963 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1964 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1966 return dns_server_dnssec_supported(t
->server
);
1969 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1974 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1976 if (!dns_transaction_dnssec_supported(t
))
1979 SET_FOREACH(dt
, t
->dnssec_transactions
)
1980 if (!dns_transaction_dnssec_supported(dt
))
1986 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
1987 DnsResourceRecord
*rr
;
1994 * Retrieve all auxiliary RRs for the answer we got, so that
1995 * we can verify signatures or prove that RRs are rightfully
1996 * unsigned. Specifically:
1998 * - For RRSIG we get the matching DNSKEY
1999 * - For DNSKEY we get the matching DS
2000 * - For unsigned SOA/NS we get the matching DS
2001 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2002 * - For other unsigned RRs we get the matching SOA RR
2003 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2004 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2005 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2008 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2010 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2011 return 0; /* We only need to validate stuff from the network */
2012 if (!dns_transaction_dnssec_supported(t
))
2013 return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */
2015 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2017 if (dns_type_is_pseudo(rr
->key
->type
))
2020 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2021 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2027 switch (rr
->key
->type
) {
2029 case DNS_TYPE_RRSIG
: {
2030 /* For each RRSIG we request the matching DNSKEY */
2031 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2033 /* If this RRSIG is about a DNSKEY RR and the
2034 * signer is the same as the owner, then we
2035 * already have the DNSKEY, and we don't have
2036 * to look for more. */
2037 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2038 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2045 /* If the signer is not a parent of our
2046 * original query, then this is about an
2047 * auxiliary RRset, but not anything we asked
2048 * for. In this case we aren't interested,
2049 * because we don't want to request additional
2050 * RRs for stuff we didn't really ask for, and
2051 * also to avoid request loops, where
2052 * additional RRs from one transaction result
2053 * in another transaction whose additional RRs
2054 * point back to the original transaction, and
2056 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2062 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2066 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2067 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2068 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2074 case DNS_TYPE_DNSKEY
: {
2075 /* For each DNSKEY we request the matching DS */
2076 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2078 /* If the DNSKEY we are looking at is not for
2079 * zone we are interested in, nor any of its
2080 * parents, we aren't interested, and don't
2081 * request it. After all, we don't want to end
2082 * up in request loops, and want to keep
2083 * additional traffic down. */
2085 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2091 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2095 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2096 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2097 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2106 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2108 /* For an unsigned SOA or NS, try to acquire
2109 * the matching DS RR, as we are at a zone cut
2110 * then, and whether a DS exists tells us
2111 * whether the zone is signed. Do so only if
2112 * this RR matches our original question,
2115 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2119 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2120 * a negative reply, and we need the a SOA RR's TTL in order to cache a negative entry?
2121 * If so, we need to validate it, too. */
2123 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2126 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2130 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2131 * what we are looking for, otherwise there's no value in it for us. */
2132 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2139 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2145 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2149 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2150 t
->id
, dns_resource_key_name(rr
->key
));
2151 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2159 case DNS_TYPE_CNAME
:
2160 case DNS_TYPE_DNAME
: {
2161 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2164 /* CNAMEs and DNAMEs cannot be located at a
2165 * zone apex, hence ask for the parent SOA for
2166 * unsigned CNAME/DNAME RRs, maybe that's the
2167 * apex. But do all that only if this is
2168 * actually a response to our original
2171 * Similar for DS RRs, which are signed when
2172 * the parent SOA is signed. */
2174 r
= dns_transaction_is_primary_response(t
, rr
);
2180 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2186 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2192 name
= dns_resource_key_name(rr
->key
);
2193 r
= dns_name_parent(&name
);
2199 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2203 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2204 t
->id
, dns_resource_key_name(rr
->key
));
2205 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2213 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2215 /* For other unsigned RRsets (including
2216 * NSEC/NSEC3!), look for proof the zone is
2217 * unsigned, by requesting the SOA RR of the
2218 * zone. However, do so only if they are
2219 * directly relevant to our original
2222 r
= dns_transaction_is_primary_response(t
, rr
);
2228 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2234 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2238 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2239 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2240 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2247 /* Above, we requested everything necessary to validate what
2248 * we got. Now, let's request what we need to validate what we
2251 r
= dns_transaction_has_unsigned_negative_answer(t
);
2258 name
= dns_resource_key_name(t
->key
);
2260 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2261 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2262 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2263 * though they have further children. If this was a DS request, then it's signed when the parent zone
2264 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2265 * to see if that is signed. */
2267 if (t
->key
->type
== DNS_TYPE_DS
) {
2268 r
= dns_name_parent(&name
);
2270 type
= DNS_TYPE_SOA
;
2271 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2272 name
, t
->id
, dns_resource_key_name(t
->key
));
2276 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2279 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2283 type
= DNS_TYPE_SOA
;
2284 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2289 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2291 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2295 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2301 return dns_transaction_dnssec_is_live(t
);
2304 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2308 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2309 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2310 the state is VALIDATING however, we should check if we are complete now. */
2312 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2313 dns_transaction_process_dnssec(t
);
2316 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2317 DnsResourceRecord
*rr
;
2322 /* Add all DNSKEY RRs from the answer that are validated by DS
2323 * RRs from the list of validated keys to the list of
2324 * validated keys. */
2326 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2328 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2334 /* If so, the DNSKEY is validated too. */
2335 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2343 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2349 /* Checks if the RR we are looking for must be signed with an
2350 * RRSIG. This is used for positive responses. */
2352 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2355 if (dns_type_is_pseudo(rr
->key
->type
))
2358 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2364 switch (rr
->key
->type
) {
2366 case DNS_TYPE_RRSIG
:
2367 /* RRSIGs are the signatures themselves, they need no signing. */
2374 /* For SOA or NS RRs we look for a matching DS transaction */
2376 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2378 if (dt
->key
->class != rr
->key
->class)
2380 if (dt
->key
->type
!= DNS_TYPE_DS
)
2383 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2389 /* We found a DS transactions for the SOA/NS
2390 * RRs we are looking at. If it discovered signed DS
2391 * RRs, then we need to be signed, too. */
2393 if (!dt
->answer_authenticated
)
2396 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2399 /* We found nothing that proves this is safe to leave
2400 * this unauthenticated, hence ask inist on
2401 * authentication. */
2406 case DNS_TYPE_CNAME
:
2407 case DNS_TYPE_DNAME
: {
2408 const char *parent
= NULL
;
2412 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2414 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2417 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2419 if (dt
->key
->class != rr
->key
->class)
2421 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2425 parent
= dns_resource_key_name(rr
->key
);
2426 r
= dns_name_parent(&parent
);
2430 if (rr
->key
->type
== DNS_TYPE_DS
)
2433 /* A CNAME/DNAME without a parent? That's sooo weird. */
2434 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2435 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2439 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2445 return t
->answer_authenticated
;
2454 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2456 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2458 if (dt
->key
->class != rr
->key
->class)
2460 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2463 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2469 /* We found the transaction that was supposed to find
2470 * the SOA RR for us. It was successful, but found no
2471 * RR for us. This means we are not at a zone cut. In
2472 * this case, we require authentication if the SOA
2473 * lookup was authenticated too. */
2474 return t
->answer_authenticated
;
2481 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2486 /* If DNSSEC downgrade mode is on, checks whether the
2487 * specified RR is one level below a TLD we have proven not to
2488 * exist. In such a case we assume that this is a private
2489 * domain, and permit it.
2491 * This detects cases like the Fritz!Box router networks. Each
2492 * Fritz!Box router serves a private "fritz.box" zone, in the
2493 * non-existing TLD "box". Requests for the "fritz.box" domain
2494 * are served by the router itself, while requests for the
2495 * "box" domain will result in NXDOMAIN.
2497 * Note that this logic is unable to detect cases where a
2498 * router serves a private DNS zone directly under
2499 * non-existing TLD. In such a case we cannot detect whether
2500 * the TLD is supposed to exist or not, as all requests we
2501 * make for it will be answered by the router's zone, and not
2502 * by the root zone. */
2506 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2507 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2509 tld
= dns_resource_key_name(key
);
2510 r
= dns_name_parent(&tld
);
2514 return false; /* Already the root domain */
2516 if (!dns_name_is_single_label(tld
))
2519 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2521 if (dt
->key
->class != key
->class)
2524 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2530 /* We found an auxiliary lookup we did for the TLD. If
2531 * that returned with NXDOMAIN, we know the TLD didn't
2532 * exist, and hence this might be a private zone. */
2534 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2540 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2541 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2549 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2550 * this negative reply */
2552 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2555 if (dns_type_is_pseudo(t
->key
->type
))
2558 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2564 r
= dns_transaction_in_private_tld(t
, t
->key
);
2568 /* The lookup is from a TLD that is proven not to
2569 * exist, and we are in downgrade mode, hence ignore
2570 * that fact that we didn't get any NSEC RRs. */
2572 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2573 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2577 name
= dns_resource_key_name(t
->key
);
2579 if (t
->key
->type
== DNS_TYPE_DS
) {
2581 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2582 * hence check the parent SOA in this case. */
2584 r
= dns_name_parent(&name
);
2590 type
= DNS_TYPE_SOA
;
2592 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2593 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2596 /* For all other negative replies, check for the SOA lookup */
2597 type
= DNS_TYPE_SOA
;
2599 /* For all other RRs we check the SOA on the same level to see
2600 * if it's signed. */
2602 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2604 if (dt
->key
->class != t
->key
->class)
2606 if (dt
->key
->type
!= type
)
2609 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2615 return dt
->answer_authenticated
;
2618 /* If in doubt, require NSEC/NSEC3 */
2622 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2623 DnsResourceRecord
*rrsig
;
2627 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2628 * the specified RRset is authenticated (i.e. has a matching
2631 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2637 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2640 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2646 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2648 if (dt
->key
->class != rr
->key
->class)
2651 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2653 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2659 /* OK, we found an auxiliary DNSKEY
2660 * lookup. If that lookup is
2661 * authenticated, report this. */
2663 if (dt
->answer_authenticated
)
2668 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2670 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2676 /* OK, we found an auxiliary DS
2677 * lookup. If that lookup is
2678 * authenticated and non-zero, we
2681 if (!dt
->answer_authenticated
)
2684 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2689 return found
? false : -ENXIO
;
2692 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2696 /* We know that the root domain is signed, hence if it appears
2697 * not to be signed, there's a problem with the DNS server */
2699 return rr
->key
->class == DNS_CLASS_IN
&&
2700 dns_name_is_root(dns_resource_key_name(rr
->key
));
2703 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2704 DnsResourceRecord
*rr
;
2709 /* Maybe warn the user that we encountered a revoked DNSKEY
2710 * for a key from our trust anchor. Note that we don't care
2711 * whether the DNSKEY can be authenticated or not. It's
2712 * sufficient if it is self-signed. */
2714 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2715 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2723 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2729 /* Removes all DNSKEY/DS objects from t->validated_keys that
2730 * our trust anchors database considers revoked. */
2733 DnsResourceRecord
*rr
;
2737 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2738 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2742 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2756 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2762 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2764 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2766 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2769 if (!dt
->answer_authenticated
)
2772 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2781 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2782 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2783 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2786 static int dnssec_validate_records(
2790 DnsAnswer
**validated
) {
2792 DnsResourceRecord
*rr
;
2795 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2797 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2798 DnsResourceRecord
*rrsig
= NULL
;
2799 DnssecResult result
;
2801 switch (rr
->key
->type
) {
2802 case DNS_TYPE_RRSIG
:
2805 case DNS_TYPE_DNSKEY
:
2806 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2807 if (phase
== DNSSEC_PHASE_NSEC
)
2812 case DNS_TYPE_NSEC3
:
2815 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2816 if (phase
== DNSSEC_PHASE_DNSKEY
)
2821 /* We validate all other RRs only in the ALL phases */
2822 if (phase
!= DNSSEC_PHASE_ALL
)
2826 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2830 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2832 if (result
== DNSSEC_VALIDATED
) {
2834 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2835 /* If we just validated a DNSKEY RRset, then let's add these keys to
2836 * the set of validated keys for this transaction. */
2838 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2842 /* Some of the DNSKEYs we just added might already have been revoked,
2843 * remove them again in that case. */
2844 r
= dns_transaction_invalidate_revoked_keys(t
);
2849 /* Add the validated RRset to the new list of validated
2850 * RRsets, and remove it from the unvalidated RRsets.
2851 * We mark the RRset as authenticated and cacheable. */
2852 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2856 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2858 /* Exit the loop, we dropped something from the answer, start from the beginning */
2862 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2863 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2864 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2865 if (phase
!= DNSSEC_PHASE_ALL
)
2868 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2869 bool authenticated
= false;
2872 /* This RRset validated, but as a wildcard. This means we need
2873 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2875 /* First step, determine the source of synthesis */
2876 r
= dns_resource_record_source(rrsig
, &source
);
2880 r
= dnssec_test_positive_wildcard(*validated
,
2881 dns_resource_key_name(rr
->key
),
2883 rrsig
->rrsig
.signer
,
2886 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2888 result
= DNSSEC_INVALID
;
2890 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2891 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2895 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2897 /* Exit the loop, we dropped something from the answer, start from the beginning */
2902 if (result
== DNSSEC_NO_SIGNATURE
) {
2903 r
= dns_transaction_requires_rrsig(t
, rr
);
2907 /* Data does not require signing. In that case, just copy it over,
2908 * but remember that this is by no means authenticated. */
2909 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2913 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2917 r
= dns_transaction_known_signed(t
, rr
);
2921 /* This is an RR we know has to be signed. If it isn't this means
2922 * the server is not attaching RRSIGs, hence complain. */
2924 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2926 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2928 /* Downgrading is OK? If so, just consider the information unsigned */
2930 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2934 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2938 /* Otherwise, fail */
2939 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2943 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2947 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2949 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2950 * mode, hence ignore the fact that this was not signed. */
2952 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2953 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2955 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2959 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2966 DNSSEC_SIGNATURE_EXPIRED
,
2967 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2969 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2970 if (r
< 0 && r
!= -ENXIO
)
2973 /* The DNSKEY transaction was not authenticated, this means there's
2974 * no DS for this, which means it's OK if no keys are found for this signature. */
2976 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2980 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2985 r
= dns_transaction_is_primary_response(t
, rr
);
2989 /* Look for a matching DNAME for this CNAME */
2990 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2994 /* Also look among the stuff we already validated */
2995 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3003 DNSSEC_SIGNATURE_EXPIRED
,
3004 DNSSEC_NO_SIGNATURE
))
3005 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3006 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3007 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3009 /* This is a primary response to our question, and it failed validation.
3011 t
->answer_dnssec_result
= result
;
3015 /* This is a primary response, but we do have a DNAME RR
3016 * in the RR that can replay this CNAME, hence rely on
3017 * that, and we can remove the CNAME in favour of it. */
3020 /* This is just some auxiliary data. Just remove the RRset and continue. */
3021 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3025 /* We dropped something from the answer, start from the beginning. */
3029 return 2; /* Finito. */
3032 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3033 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3035 DnsAnswerFlags flags
;
3037 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3041 /* We have now collected all DS and DNSKEY RRs in
3042 * t->validated_keys, let's see which RRs we can now
3043 * authenticate with that. */
3045 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3048 /* Already validated */
3049 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3052 /* Our own stuff needs no validation */
3053 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3054 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3055 t
->answer_authenticated
= true;
3059 /* Cached stuff is not affected by validation. */
3060 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3063 if (!dns_transaction_dnssec_supported_full(t
)) {
3064 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3065 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3066 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3070 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3072 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3074 /* First, see if this response contains any revoked trust
3075 * anchors we care about */
3076 r
= dns_transaction_check_revoked_trust_anchors(t
);
3080 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3081 r
= dns_transaction_copy_validated(t
);
3085 /* Second, see if there are DNSKEYs we already know a
3086 * validated DS for. */
3087 r
= dns_transaction_validate_dnskey_by_ds(t
);
3091 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3092 * anchor says are revoked. After all we might have marked
3093 * some keys revoked above, but they might still be lingering
3094 * in our validated_keys list. */
3095 r
= dns_transaction_invalidate_revoked_keys(t
);
3099 phase
= DNSSEC_PHASE_DNSKEY
;
3101 bool have_nsec
= false;
3103 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3107 /* Try again as long as we managed to achieve something */
3111 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3112 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3113 phase
= DNSSEC_PHASE_NSEC
;
3117 if (phase
!= DNSSEC_PHASE_ALL
) {
3118 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3119 * Note that in this third phase we start to remove RRs we couldn't validate. */
3120 phase
= DNSSEC_PHASE_ALL
;
3128 dns_answer_unref(t
->answer
);
3129 t
->answer
= TAKE_PTR(validated
);
3131 /* At this point the answer only contains validated
3132 * RRsets. Now, let's see if it actually answers the question
3133 * we asked. If so, great! If it doesn't, then see if
3134 * NSEC/NSEC3 can prove this. */
3135 r
= dns_transaction_has_positive_answer(t
, &flags
);
3137 /* Yes, it answers the question! */
3139 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3140 /* The answer is fully authenticated, yay. */
3141 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3142 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3143 t
->answer_authenticated
= true;
3145 /* The answer is not fully authenticated. */
3146 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3147 t
->answer_authenticated
= false;
3150 } else if (r
== 0) {
3151 DnssecNsecResult nr
;
3152 bool authenticated
= false;
3154 /* Bummer! Let's check NSEC/NSEC3 */
3155 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3161 case DNSSEC_NSEC_NXDOMAIN
:
3162 /* NSEC proves the domain doesn't exist. Very good. */
3163 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3164 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3165 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3166 t
->answer_authenticated
= authenticated
;
3168 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3171 case DNSSEC_NSEC_NODATA
:
3172 /* NSEC proves that there's no data here, very good. */
3173 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3174 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3175 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3176 t
->answer_authenticated
= authenticated
;
3178 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3181 case DNSSEC_NSEC_OPTOUT
:
3182 /* NSEC3 says the data might not be signed */
3183 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3184 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3185 t
->answer_authenticated
= false;
3187 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3190 case DNSSEC_NSEC_NO_RR
:
3191 /* No NSEC data? Bummer! */
3193 r
= dns_transaction_requires_nsec(t
);
3197 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3198 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3200 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3201 t
->answer_authenticated
= false;
3202 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3207 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3208 /* We don't know the NSEC3 algorithm used? */
3209 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3210 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3213 case DNSSEC_NSEC_FOUND
:
3214 case DNSSEC_NSEC_CNAME
:
3215 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3216 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3217 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3221 assert_not_reached("Unexpected NSEC result.");
3228 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3229 [DNS_TRANSACTION_NULL
] = "null",
3230 [DNS_TRANSACTION_PENDING
] = "pending",
3231 [DNS_TRANSACTION_VALIDATING
] = "validating",
3232 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3233 [DNS_TRANSACTION_SUCCESS
] = "success",
3234 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3235 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3236 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3237 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3238 [DNS_TRANSACTION_ERRNO
] = "errno",
3239 [DNS_TRANSACTION_ABORTED
] = "aborted",
3240 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3241 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3242 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3243 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3244 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3246 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3248 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3249 [DNS_TRANSACTION_NETWORK
] = "network",
3250 [DNS_TRANSACTION_CACHE
] = "cache",
3251 [DNS_TRANSACTION_ZONE
] = "zone",
3252 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3254 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);