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
156 * number of 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 /* Packet from localhost? */
686 if (!t
->scope
->manager
->cache_from_localhost
&&
687 in_addr_is_localhost(t
->received
->family
, &t
->received
->sender
) != 0)
690 dns_cache_put(&t
->scope
->cache
,
691 t
->scope
->manager
->enable_cache
,
695 t
->answer_authenticated
,
699 &t
->received
->sender
);
702 static bool dns_transaction_dnssec_is_live(DnsTransaction
*t
) {
707 SET_FOREACH(dt
, t
->dnssec_transactions
)
708 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
714 static int dns_transaction_dnssec_ready(DnsTransaction
*t
) {
719 /* Checks whether the auxiliary DNSSEC transactions of our transaction have completed, or are still
720 * ongoing. Returns 0, if we aren't ready for the DNSSEC validation, positive if we are. */
722 SET_FOREACH(dt
, t
->dnssec_transactions
) {
726 case DNS_TRANSACTION_NULL
:
727 case DNS_TRANSACTION_PENDING
:
728 case DNS_TRANSACTION_VALIDATING
:
732 case DNS_TRANSACTION_RCODE_FAILURE
:
733 if (!IN_SET(dt
->answer_rcode
, DNS_RCODE_NXDOMAIN
, DNS_RCODE_SERVFAIL
)) {
734 log_debug("Auxiliary DNSSEC RR query failed with rcode=%s.", dns_rcode_to_string(dt
->answer_rcode
));
738 /* Fall-through: NXDOMAIN/SERVFAIL is good enough for us. This is because some DNS servers
739 * erroneously return NXDOMAIN/SERVFAIL for empty non-terminals (Akamai...) or missing DS
740 * records (Facebook), and we need to handle that nicely, when asking for parent SOA or similar
741 * RRs to make unsigned proofs. */
743 case DNS_TRANSACTION_SUCCESS
:
747 case DNS_TRANSACTION_DNSSEC_FAILED
:
748 /* We handle DNSSEC failures different from other errors, as we care about the DNSSEC
749 * validationr result */
751 log_debug("Auxiliary DNSSEC RR query failed validation: %s", dnssec_result_to_string(dt
->answer_dnssec_result
));
752 t
->answer_dnssec_result
= dt
->answer_dnssec_result
; /* Copy error code over */
753 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
757 log_debug("Auxiliary DNSSEC RR query failed with %s", dns_transaction_state_to_string(dt
->state
));
762 /* All is ready, we can go and validate */
766 t
->answer_dnssec_result
= DNSSEC_FAILED_AUXILIARY
;
767 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
771 static void dns_transaction_process_dnssec(DnsTransaction
*t
) {
776 /* Are there ongoing DNSSEC transactions? If so, let's wait for them. */
777 r
= dns_transaction_dnssec_ready(t
);
780 if (r
== 0) /* We aren't ready yet (or one of our auxiliary transactions failed, and we shouldn't validate now */
783 /* See if we learnt things from the additional DNSSEC transactions, that we didn't know before, and better
784 * restart the lookup immediately. */
785 r
= dns_transaction_maybe_restart(t
);
788 if (r
> 0) /* Transaction got restarted... */
791 /* All our auxiliary DNSSEC transactions are complete now. Try
792 * to validate our RRset now. */
793 r
= dns_transaction_validate_dnssec(t
);
795 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
801 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
&&
802 t
->scope
->dnssec_mode
== DNSSEC_YES
) {
804 /* We are not in automatic downgrade mode, and the server is bad. Let's try a different server, maybe
807 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
808 /* We tried fewer servers on this transaction than we know, let's try another one then */
809 dns_transaction_retry(t
, true);
813 /* OK, let's give up, apparently all servers we tried didn't work. */
814 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
818 if (!IN_SET(t
->answer_dnssec_result
,
819 _DNSSEC_RESULT_INVALID
, /* No DNSSEC validation enabled */
820 DNSSEC_VALIDATED
, /* Answer is signed and validated successfully */
821 DNSSEC_UNSIGNED
, /* Answer is right-fully unsigned */
822 DNSSEC_INCOMPATIBLE_SERVER
)) { /* Server does not do DNSSEC (Yay, we are downgrade attack vulnerable!) */
823 dns_transaction_complete(t
, DNS_TRANSACTION_DNSSEC_FAILED
);
827 if (t
->answer_dnssec_result
== DNSSEC_INCOMPATIBLE_SERVER
)
828 dns_server_warn_downgrade(t
->server
);
830 dns_transaction_cache_answer(t
);
832 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
833 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
835 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
840 dns_transaction_complete_errno(t
, r
);
843 static int dns_transaction_has_positive_answer(DnsTransaction
*t
, DnsAnswerFlags
*flags
) {
848 /* Checks whether the answer is positive, i.e. either a direct
849 * answer to the question, or a CNAME/DNAME for it */
851 r
= dns_answer_match_key(t
->answer
, t
->key
, flags
);
855 r
= dns_answer_find_cname_or_dname(t
->answer
, t
->key
, NULL
, flags
);
862 static int dns_transaction_fix_rcode(DnsTransaction
*t
) {
867 /* Fix up the RCODE to SUCCESS if we get at least one matching RR in a response. Note that this contradicts the
868 * DNS RFCs a bit. Specifically, RFC 6604 Section 3 clarifies that the RCODE shall say something about a
869 * CNAME/DNAME chain element coming after the last chain element contained in the message, and not the first
870 * one included. However, it also indicates that not all DNS servers implement this correctly. Moreover, when
871 * using DNSSEC we usually only can prove the first element of a CNAME/DNAME chain anyway, hence let's settle
872 * on always processing the RCODE as referring to the immediate look-up we do, i.e. the first element of a
873 * CNAME/DNAME chain. This way, we uniformly handle CNAME/DNAME chains, regardless if the DNS server
874 * incorrectly implements RCODE, whether DNSSEC is in use, or whether the DNS server only supplied us with an
875 * incomplete CNAME/DNAME chain.
877 * Or in other words: if we get at least one positive reply in a message we patch NXDOMAIN to become SUCCESS,
878 * and then rely on the CNAME chasing logic to figure out that there's actually a CNAME error with a new
881 if (t
->answer_rcode
!= DNS_RCODE_NXDOMAIN
)
884 r
= dns_transaction_has_positive_answer(t
, NULL
);
888 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
892 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
) {
898 assert(t
->scope
->manager
);
900 if (t
->state
!= DNS_TRANSACTION_PENDING
)
903 /* Note that this call might invalidate the query. Callers
904 * should hence not attempt to access the query or transaction
905 * after calling this function. */
907 log_debug("Processing incoming packet on transaction %" PRIu16
" (rcode=%s).",
908 t
->id
, dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
910 switch (t
->scope
->protocol
) {
912 case DNS_PROTOCOL_LLMNR
:
913 /* For LLMNR we will not accept any packets from other interfaces */
915 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
918 if (p
->family
!= t
->scope
->family
)
921 /* Tentative packets are not full responses but still
922 * useful for identifying uniqueness conflicts during
924 if (DNS_PACKET_LLMNR_T(p
)) {
925 dns_transaction_tentative(t
, p
);
931 case DNS_PROTOCOL_MDNS
:
932 /* For mDNS we will not accept any packets from other interfaces */
934 if (p
->ifindex
!= dns_scope_ifindex(t
->scope
))
937 if (p
->family
!= t
->scope
->family
)
942 case DNS_PROTOCOL_DNS
:
943 /* Note that we do not need to verify the
944 * addresses/port numbers of incoming traffic, as we
945 * invoked connect() on our UDP socket in which case
946 * the kernel already does the needed verification for
951 assert_not_reached("Invalid DNS protocol.");
954 if (t
->received
!= p
) {
955 dns_packet_unref(t
->received
);
956 t
->received
= dns_packet_ref(p
);
959 t
->answer_source
= DNS_TRANSACTION_NETWORK
;
961 if (p
->ipproto
== IPPROTO_TCP
) {
962 if (DNS_PACKET_TC(p
)) {
963 /* Truncated via TCP? Somebody must be fucking with us */
964 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
968 if (DNS_PACKET_ID(p
) != t
->id
) {
969 /* Not the reply to our query? Somebody must be fucking with us */
970 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
975 switch (t
->scope
->protocol
) {
977 case DNS_PROTOCOL_DNS
:
980 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_FORMERR
, DNS_RCODE_SERVFAIL
, DNS_RCODE_NOTIMP
)) {
982 /* Request failed, immediately try again with reduced features */
984 if (t
->current_feature_level
<= DNS_SERVER_FEATURE_LEVEL_UDP
) {
986 /* This was already at UDP feature level? If so, it doesn't make sense to downgrade
987 * this transaction anymore, but let's see if it might make sense to send the request
988 * to a different DNS server instead. If not let's process the response, and accept the
989 * rcode. Note that we don't retry on TCP, since that's a suitable way to mitigate
990 * packet loss, but is not going to give us better rcodes should we actually have
991 * managed to get them already at UDP level. */
993 if (t
->n_picked_servers
< dns_scope_get_n_dns_servers(t
->scope
)) {
994 /* We tried fewer servers on this transaction than we know, let's try another one then */
995 dns_transaction_retry(t
, true);
999 /* Give up, accept the rcode */
1000 log_debug("Server returned error: %s", dns_rcode_to_string(DNS_PACKET_RCODE(p
)));
1004 /* Reduce this feature level by one and try again. */
1005 switch (t
->current_feature_level
) {
1006 case DNS_SERVER_FEATURE_LEVEL_TLS_DO
:
1007 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
;
1009 case DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
+ 1:
1010 /* Skip plain TLS when TLS is not supported */
1011 t
->clamp_feature_level
= DNS_SERVER_FEATURE_LEVEL_TLS_PLAIN
- 1;
1014 t
->clamp_feature_level
= t
->current_feature_level
- 1;
1017 log_debug("Server returned error %s, retrying transaction with reduced feature level %s.",
1018 dns_rcode_to_string(DNS_PACKET_RCODE(p
)),
1019 dns_server_feature_level_to_string(t
->clamp_feature_level
));
1021 dns_transaction_retry(t
, false /* use the same server */);
1025 if (DNS_PACKET_RCODE(p
) == DNS_RCODE_REFUSED
) {
1026 /* This server refused our request? If so, try again, use a different server */
1027 log_debug("Server returned REFUSED, switching servers, and retrying.");
1028 dns_transaction_retry(t
, true /* pick a new server */);
1032 if (DNS_PACKET_TC(p
))
1033 dns_server_packet_truncated(t
->server
, t
->current_feature_level
);
1037 case DNS_PROTOCOL_LLMNR
:
1038 case DNS_PROTOCOL_MDNS
:
1039 dns_scope_packet_received(t
->scope
, p
->timestamp
- t
->start_usec
);
1043 assert_not_reached("Invalid DNS protocol.");
1046 if (DNS_PACKET_TC(p
)) {
1048 /* Truncated packets for mDNS are not allowed. Give up immediately. */
1049 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
) {
1050 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1054 log_debug("Reply truncated, retrying via TCP.");
1056 /* Response was truncated, let's try again with good old TCP */
1057 r
= dns_transaction_emit_tcp(t
);
1059 /* No servers found? Damn! */
1060 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1063 if (r
== -EOPNOTSUPP
) {
1064 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1065 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1069 /* On LLMNR, if we cannot connect to the host,
1070 * we immediately give up */
1071 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1074 /* On DNS, couldn't send? Try immediately again, with a new server */
1075 dns_transaction_retry(t
, true);
1081 /* After the superficial checks, actually parse the message. */
1082 r
= dns_packet_extract(p
);
1084 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1089 /* Report that we successfully received a valid packet with a good rcode after we initially got a bad
1090 * rcode and subsequently downgraded the protocol */
1092 if (IN_SET(DNS_PACKET_RCODE(p
), DNS_RCODE_SUCCESS
, DNS_RCODE_NXDOMAIN
) &&
1093 t
->clamp_feature_level
!= _DNS_SERVER_FEATURE_LEVEL_INVALID
)
1094 dns_server_packet_rcode_downgrade(t
->server
, t
->clamp_feature_level
);
1096 /* Report that the OPT RR was missing */
1098 dns_server_packet_bad_opt(t
->server
, t
->current_feature_level
);
1100 /* Report that we successfully received a packet */
1101 dns_server_packet_received(t
->server
, p
->ipproto
, t
->current_feature_level
, p
->size
);
1104 /* See if we know things we didn't know before that indicate we better restart the lookup immediately. */
1105 r
= dns_transaction_maybe_restart(t
);
1108 if (r
> 0) /* Transaction got restarted... */
1111 /* When dealing with protocols other than mDNS only consider responses with equivalent query section
1112 * to the request. For mDNS this check doesn't make sense, because the section 6 of RFC6762 states
1113 * that "Multicast DNS responses MUST NOT contain any questions in the Question Section". */
1114 if (t
->scope
->protocol
!= DNS_PROTOCOL_MDNS
) {
1115 r
= dns_packet_is_reply_for(p
, t
->key
);
1119 dns_transaction_complete(t
, DNS_TRANSACTION_INVALID_REPLY
);
1124 /* Install the answer as answer to the transaction */
1125 dns_answer_unref(t
->answer
);
1126 t
->answer
= dns_answer_ref(p
->answer
);
1127 t
->answer_rcode
= DNS_PACKET_RCODE(p
);
1128 t
->answer_dnssec_result
= _DNSSEC_RESULT_INVALID
;
1129 t
->answer_authenticated
= false;
1131 r
= dns_transaction_fix_rcode(t
);
1135 /* Block GC while starting requests for additional DNSSEC RRs */
1137 r
= dns_transaction_request_dnssec_keys(t
);
1140 /* Maybe the transaction is ready for GC'ing now? If so, free it and return. */
1141 if (!dns_transaction_gc(t
))
1144 /* Requesting additional keys might have resulted in this transaction to fail, since the auxiliary
1145 * request failed for some reason. If so, we are not in pending state anymore, and we should exit
1147 if (t
->state
!= DNS_TRANSACTION_PENDING
)
1152 /* There are DNSSEC transactions pending now. Update the state accordingly. */
1153 t
->state
= DNS_TRANSACTION_VALIDATING
;
1154 dns_transaction_close_connection(t
);
1155 dns_transaction_stop_timeout(t
);
1159 dns_transaction_process_dnssec(t
);
1163 dns_transaction_complete_errno(t
, r
);
1166 static int on_dns_packet(sd_event_source
*s
, int fd
, uint32_t revents
, void *userdata
) {
1167 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1168 DnsTransaction
*t
= userdata
;
1174 r
= manager_recv(t
->scope
->manager
, fd
, DNS_PROTOCOL_DNS
, &p
);
1175 if (ERRNO_IS_DISCONNECT(r
)) {
1178 /* UDP connection failures get reported via ICMP and then are possibly delivered to us on the
1179 * next recvmsg(). Treat this like a lost packet. */
1181 log_debug_errno(r
, "Connection failure for DNS UDP packet: %m");
1182 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &usec
) >= 0);
1183 dns_server_packet_lost(t
->server
, IPPROTO_UDP
, t
->current_feature_level
);
1185 dns_transaction_retry(t
, true);
1189 dns_transaction_complete_errno(t
, r
);
1193 /* Spurious wakeup without any data */
1196 r
= dns_packet_validate_reply(p
);
1198 log_debug_errno(r
, "Received invalid DNS packet as response, ignoring: %m");
1202 log_debug("Received inappropriate DNS packet as response, ignoring.");
1206 if (DNS_PACKET_ID(p
) != t
->id
) {
1207 log_debug("Received packet with incorrect transaction ID, ignoring.");
1211 dns_transaction_process_reply(t
, p
);
1215 static int dns_transaction_emit_udp(DnsTransaction
*t
) {
1220 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1222 r
= dns_transaction_pick_server(t
);
1226 if (t
->current_feature_level
< DNS_SERVER_FEATURE_LEVEL_UDP
|| DNS_SERVER_FEATURE_LEVEL_IS_TLS(t
->current_feature_level
))
1227 return -EAGAIN
; /* Sorry, can't do UDP, try TCP! */
1229 if (!dns_server_dnssec_supported(t
->server
) && dns_type_is_dnssec(t
->key
->type
))
1232 if (r
> 0 || t
->dns_udp_fd
< 0) { /* Server changed, or no connection yet. */
1235 dns_transaction_close_connection(t
);
1237 fd
= dns_scope_socket_udp(t
->scope
, t
->server
);
1241 r
= sd_event_add_io(t
->scope
->manager
->event
, &t
->dns_udp_event_source
, fd
, EPOLLIN
, on_dns_packet
, t
);
1247 (void) sd_event_source_set_description(t
->dns_udp_event_source
, "dns-transaction-udp");
1251 r
= dns_server_adjust_opt(t
->server
, t
->sent
, t
->current_feature_level
);
1255 dns_transaction_close_connection(t
);
1257 r
= dns_scope_emit_udp(t
->scope
, t
->dns_udp_fd
, t
->sent
);
1261 dns_transaction_reset_answer(t
);
1266 static int on_transaction_timeout(sd_event_source
*s
, usec_t usec
, void *userdata
) {
1267 DnsTransaction
*t
= userdata
;
1272 if (!t
->initial_jitter_scheduled
|| t
->initial_jitter_elapsed
) {
1273 /* Timeout reached? Increase the timeout for the server used */
1274 switch (t
->scope
->protocol
) {
1276 case DNS_PROTOCOL_DNS
:
1278 dns_server_packet_lost(t
->server
, t
->stream
? IPPROTO_TCP
: IPPROTO_UDP
, t
->current_feature_level
);
1281 case DNS_PROTOCOL_LLMNR
:
1282 case DNS_PROTOCOL_MDNS
:
1283 dns_scope_packet_lost(t
->scope
, usec
- t
->start_usec
);
1287 assert_not_reached("Invalid DNS protocol.");
1290 if (t
->initial_jitter_scheduled
)
1291 t
->initial_jitter_elapsed
= true;
1294 log_debug("Timeout reached on transaction %" PRIu16
".", t
->id
);
1296 dns_transaction_retry(t
, true);
1300 static usec_t
transaction_get_resend_timeout(DnsTransaction
*t
) {
1304 switch (t
->scope
->protocol
) {
1306 case DNS_PROTOCOL_DNS
:
1308 /* When we do TCP, grant a much longer timeout, as in this case there's no need for us to quickly
1309 * resend, as the kernel does that anyway for us, and we really don't want to interrupt it in that
1312 return TRANSACTION_TCP_TIMEOUT_USEC
;
1314 return DNS_TIMEOUT_USEC
;
1316 case DNS_PROTOCOL_MDNS
:
1317 assert(t
->n_attempts
> 0);
1319 return MDNS_PROBING_INTERVAL_USEC
;
1321 return (1 << (t
->n_attempts
- 1)) * USEC_PER_SEC
;
1323 case DNS_PROTOCOL_LLMNR
:
1324 return t
->scope
->resend_timeout
;
1327 assert_not_reached("Invalid DNS protocol.");
1331 static int dns_transaction_prepare(DnsTransaction
*t
, usec_t ts
) {
1336 /* Returns 0 if dns_transaction_complete() has been called. In that case the transaction and query
1337 * candidate objects may have been invalidated and must not be accessed. Returns 1 if the transaction
1338 * has been prepared. */
1340 dns_transaction_stop_timeout(t
);
1342 if (!dns_scope_network_good(t
->scope
)) {
1343 dns_transaction_complete(t
, DNS_TRANSACTION_NETWORK_DOWN
);
1347 if (t
->n_attempts
>= TRANSACTION_ATTEMPTS_MAX(t
->scope
->protocol
)) {
1348 DnsTransactionState result
;
1350 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
)
1351 /* If we didn't find anything on LLMNR, it's not an error, but a failure to resolve
1353 result
= DNS_TRANSACTION_NOT_FOUND
;
1355 result
= DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
;
1357 dns_transaction_complete(t
, result
);
1361 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& t
->tried_stream
) {
1362 /* If we already tried via a stream, then we don't
1363 * retry on LLMNR. See RFC 4795, Section 2.7. */
1364 dns_transaction_complete(t
, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
);
1371 dns_transaction_reset_answer(t
);
1372 dns_transaction_flush_dnssec_transactions(t
);
1374 /* Check the trust anchor. Do so only on classic DNS, since DNSSEC does not apply otherwise. */
1375 if (t
->scope
->protocol
== DNS_PROTOCOL_DNS
) {
1376 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, t
->key
, &t
->answer
);
1380 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1381 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1382 t
->answer_authenticated
= true;
1383 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1387 if (dns_name_is_root(dns_resource_key_name(t
->key
)) &&
1388 t
->key
->type
== DNS_TYPE_DS
) {
1390 /* Hmm, this is a request for the root DS? A
1391 * DS RR doesn't exist in the root zone, and
1392 * if our trust anchor didn't know it either,
1393 * this means we cannot do any DNSSEC logic
1396 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
1397 /* We are in downgrade mode. In this
1398 * case, synthesize an unsigned empty
1399 * response, so that the any lookup
1400 * depending on this one can continue
1401 * assuming there was no DS, and hence
1402 * the root zone was unsigned. */
1404 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1405 t
->answer_source
= DNS_TRANSACTION_TRUST_ANCHOR
;
1406 t
->answer_authenticated
= false;
1407 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1409 /* If we are not in downgrade mode,
1410 * then fail the lookup, because we
1411 * cannot reasonably answer it. There
1412 * might be DS RRs, but we don't know
1413 * them, and the DNS server won't tell
1414 * them to us (and even if it would,
1415 * we couldn't validate and trust them. */
1416 dns_transaction_complete(t
, DNS_TRANSACTION_NO_TRUST_ANCHOR
);
1422 /* Check the zone, but only if this transaction is not used
1423 * for probing or verifying a zone item. */
1424 if (set_isempty(t
->notify_zone_items
)) {
1426 r
= dns_zone_lookup(&t
->scope
->zone
, t
->key
, dns_scope_ifindex(t
->scope
), &t
->answer
, NULL
, NULL
);
1430 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
1431 t
->answer_source
= DNS_TRANSACTION_ZONE
;
1432 t
->answer_authenticated
= true;
1433 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1438 /* Check the cache, but only if this transaction is not used
1439 * for probing or verifying a zone item. */
1440 if (set_isempty(t
->notify_zone_items
)) {
1442 /* Before trying the cache, let's make sure we figured out a
1443 * server to use. Should this cause a change of server this
1444 * might flush the cache. */
1445 (void) dns_scope_get_dns_server(t
->scope
);
1447 /* Let's then prune all outdated entries */
1448 dns_cache_prune(&t
->scope
->cache
);
1450 r
= dns_cache_lookup(&t
->scope
->cache
, t
->key
, t
->clamp_ttl
, &t
->answer_rcode
, &t
->answer
, &t
->answer_authenticated
);
1454 t
->answer_source
= DNS_TRANSACTION_CACHE
;
1455 if (t
->answer_rcode
== DNS_RCODE_SUCCESS
)
1456 dns_transaction_complete(t
, DNS_TRANSACTION_SUCCESS
);
1458 dns_transaction_complete(t
, DNS_TRANSACTION_RCODE_FAILURE
);
1466 static int dns_transaction_make_packet_mdns(DnsTransaction
*t
) {
1467 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1468 bool add_known_answers
= false;
1469 DnsTransaction
*other
;
1470 DnsResourceKey
*tkey
;
1471 _cleanup_set_free_ Set
*keys
= NULL
;
1473 unsigned nscount
= 0;
1478 assert(t
->scope
->protocol
== DNS_PROTOCOL_MDNS
);
1480 /* Discard any previously prepared packet, so we can start over and coalesce again */
1481 t
->sent
= dns_packet_unref(t
->sent
);
1483 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, false);
1487 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1493 if (dns_key_is_shared(t
->key
))
1494 add_known_answers
= true;
1496 if (t
->key
->type
== DNS_TYPE_ANY
) {
1497 r
= set_ensure_put(&keys
, &dns_resource_key_hash_ops
, t
->key
);
1503 * For mDNS, we want to coalesce as many open queries in pending transactions into one single
1504 * query packet on the wire as possible. To achieve that, we iterate through all pending transactions
1505 * in our current scope, and see whether their timing constraints allow them to be sent.
1508 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1510 LIST_FOREACH(transactions_by_scope
, other
, t
->scope
->transactions
) {
1512 /* Skip ourselves */
1516 if (other
->state
!= DNS_TRANSACTION_PENDING
)
1519 if (other
->next_attempt_after
> ts
)
1522 if (qdcount
>= UINT16_MAX
)
1525 r
= dns_packet_append_key(p
, other
->key
, 0, NULL
);
1528 * If we can't stuff more questions into the packet, just give up.
1529 * One of the 'other' transactions will fire later and take care of the rest.
1537 r
= dns_transaction_prepare(other
, ts
);
1541 ts
+= transaction_get_resend_timeout(other
);
1543 r
= sd_event_add_time(
1544 other
->scope
->manager
->event
,
1545 &other
->timeout_event_source
,
1546 clock_boottime_or_monotonic(),
1548 on_transaction_timeout
, other
);
1552 (void) sd_event_source_set_description(other
->timeout_event_source
, "dns-transaction-timeout");
1554 other
->state
= DNS_TRANSACTION_PENDING
;
1555 other
->next_attempt_after
= ts
;
1559 if (dns_key_is_shared(other
->key
))
1560 add_known_answers
= true;
1562 if (other
->key
->type
== DNS_TYPE_ANY
) {
1563 r
= set_ensure_put(&keys
, &dns_resource_key_hash_ops
, other
->key
);
1569 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(qdcount
);
1571 /* Append known answer section if we're asking for any shared record */
1572 if (add_known_answers
) {
1573 r
= dns_cache_export_shared_to_packet(&t
->scope
->cache
, p
);
1578 SET_FOREACH(tkey
, keys
) {
1579 _cleanup_(dns_answer_unrefp
) DnsAnswer
*answer
= NULL
;
1582 r
= dns_zone_lookup(&t
->scope
->zone
, tkey
, t
->scope
->link
->ifindex
, &answer
, NULL
, &tentative
);
1586 r
= dns_packet_append_answer(p
, answer
);
1590 nscount
+= dns_answer_size(answer
);
1592 DNS_PACKET_HEADER(p
)->nscount
= htobe16(nscount
);
1594 t
->sent
= TAKE_PTR(p
);
1599 static int dns_transaction_make_packet(DnsTransaction
*t
) {
1600 _cleanup_(dns_packet_unrefp
) DnsPacket
*p
= NULL
;
1605 if (t
->scope
->protocol
== DNS_PROTOCOL_MDNS
)
1606 return dns_transaction_make_packet_mdns(t
);
1611 r
= dns_packet_new_query(&p
, t
->scope
->protocol
, 0, t
->scope
->dnssec_mode
!= DNSSEC_NO
);
1615 r
= dns_packet_append_key(p
, t
->key
, 0, NULL
);
1619 DNS_PACKET_HEADER(p
)->qdcount
= htobe16(1);
1620 DNS_PACKET_HEADER(p
)->id
= t
->id
;
1622 t
->sent
= TAKE_PTR(p
);
1627 int dns_transaction_go(DnsTransaction
*t
) {
1630 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
1634 /* Returns > 0 if the transaction is now pending, returns 0 if could be processed immediately and has
1635 * finished now. In the latter case, the transaction and query candidate objects must not be accessed.
1638 assert_se(sd_event_now(t
->scope
->manager
->event
, clock_boottime_or_monotonic(), &ts
) >= 0);
1640 r
= dns_transaction_prepare(t
, ts
);
1644 log_debug("Transaction %" PRIu16
" for <%s> scope %s on %s/%s.",
1646 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
),
1647 dns_protocol_to_string(t
->scope
->protocol
),
1648 t
->scope
->link
? t
->scope
->link
->ifname
: "*",
1649 af_to_name_short(t
->scope
->family
));
1651 if (!t
->initial_jitter_scheduled
&&
1652 IN_SET(t
->scope
->protocol
, DNS_PROTOCOL_LLMNR
, DNS_PROTOCOL_MDNS
)) {
1653 usec_t jitter
, accuracy
;
1655 /* RFC 4795 Section 2.7 suggests all queries should be
1656 * delayed by a random time from 0 to JITTER_INTERVAL. */
1658 t
->initial_jitter_scheduled
= true;
1660 random_bytes(&jitter
, sizeof(jitter
));
1662 switch (t
->scope
->protocol
) {
1664 case DNS_PROTOCOL_LLMNR
:
1665 jitter
%= LLMNR_JITTER_INTERVAL_USEC
;
1666 accuracy
= LLMNR_JITTER_INTERVAL_USEC
;
1669 case DNS_PROTOCOL_MDNS
:
1670 jitter
%= MDNS_JITTER_RANGE_USEC
;
1671 jitter
+= MDNS_JITTER_MIN_USEC
;
1672 accuracy
= MDNS_JITTER_RANGE_USEC
;
1675 assert_not_reached("bad protocol");
1678 r
= sd_event_add_time(
1679 t
->scope
->manager
->event
,
1680 &t
->timeout_event_source
,
1681 clock_boottime_or_monotonic(),
1682 ts
+ jitter
, accuracy
,
1683 on_transaction_timeout
, t
);
1687 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1690 t
->next_attempt_after
= ts
;
1691 t
->state
= DNS_TRANSACTION_PENDING
;
1693 log_debug("Delaying %s transaction for " USEC_FMT
"us.", dns_protocol_to_string(t
->scope
->protocol
), jitter
);
1697 /* Otherwise, we need to ask the network */
1698 r
= dns_transaction_make_packet(t
);
1702 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&&
1703 (dns_name_endswith(dns_resource_key_name(t
->key
), "in-addr.arpa") > 0 ||
1704 dns_name_endswith(dns_resource_key_name(t
->key
), "ip6.arpa") > 0)) {
1706 /* RFC 4795, Section 2.4. says reverse lookups shall
1707 * always be made via TCP on LLMNR */
1708 r
= dns_transaction_emit_tcp(t
);
1710 /* Try via UDP, and if that fails due to large size or lack of
1711 * support try via TCP */
1712 r
= dns_transaction_emit_udp(t
);
1714 log_debug("Sending query via TCP since it is too large.");
1715 else if (r
== -EAGAIN
)
1716 log_debug("Sending query via TCP since UDP isn't supported or DNS-over-TLS is selected.");
1717 if (IN_SET(r
, -EMSGSIZE
, -EAGAIN
))
1718 r
= dns_transaction_emit_tcp(t
);
1722 /* No servers to send this to? */
1723 dns_transaction_complete(t
, DNS_TRANSACTION_NO_SERVERS
);
1726 if (r
== -EOPNOTSUPP
) {
1727 /* Tried to ask for DNSSEC RRs, on a server that doesn't do DNSSEC */
1728 dns_transaction_complete(t
, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
);
1731 if (t
->scope
->protocol
== DNS_PROTOCOL_LLMNR
&& ERRNO_IS_DISCONNECT(r
)) {
1732 /* On LLMNR, if we cannot connect to a host via TCP when doing reverse lookups. This means we cannot
1733 * answer this request with this protocol. */
1734 dns_transaction_complete(t
, DNS_TRANSACTION_NOT_FOUND
);
1738 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1741 /* Couldn't send? Try immediately again, with a new server */
1742 dns_scope_next_dns_server(t
->scope
);
1744 return dns_transaction_go(t
);
1747 ts
+= transaction_get_resend_timeout(t
);
1749 r
= sd_event_add_time(
1750 t
->scope
->manager
->event
,
1751 &t
->timeout_event_source
,
1752 clock_boottime_or_monotonic(),
1754 on_transaction_timeout
, t
);
1758 (void) sd_event_source_set_description(t
->timeout_event_source
, "dns-transaction-timeout");
1760 t
->state
= DNS_TRANSACTION_PENDING
;
1761 t
->next_attempt_after
= ts
;
1766 static int dns_transaction_find_cyclic(DnsTransaction
*t
, DnsTransaction
*aux
) {
1773 /* Try to find cyclic dependencies between transaction objects */
1778 SET_FOREACH(n
, aux
->dnssec_transactions
) {
1779 r
= dns_transaction_find_cyclic(t
, n
);
1787 static int dns_transaction_add_dnssec_transaction(DnsTransaction
*t
, DnsResourceKey
*key
, DnsTransaction
**ret
) {
1788 _cleanup_(dns_transaction_gcp
) DnsTransaction
*aux
= NULL
;
1795 aux
= dns_scope_find_transaction(t
->scope
, key
, true);
1797 r
= dns_transaction_new(&aux
, t
->scope
, key
);
1801 if (set_contains(t
->dnssec_transactions
, aux
)) {
1806 r
= dns_transaction_find_cyclic(t
, aux
);
1810 char s
[DNS_RESOURCE_KEY_STRING_MAX
], saux
[DNS_RESOURCE_KEY_STRING_MAX
];
1812 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
1813 "Potential cyclic dependency, refusing to add transaction %" PRIu16
" (%s) as dependency for %" PRIu16
" (%s).",
1815 dns_resource_key_to_string(t
->key
, s
, sizeof s
),
1817 dns_resource_key_to_string(aux
->key
, saux
, sizeof saux
));
1821 r
= set_ensure_allocated(&aux
->notify_transactions_done
, NULL
);
1825 r
= set_ensure_put(&t
->dnssec_transactions
, NULL
, aux
);
1829 r
= set_ensure_put(&aux
->notify_transactions
, NULL
, t
);
1831 (void) set_remove(t
->dnssec_transactions
, aux
);
1835 *ret
= TAKE_PTR(aux
);
1839 static int dns_transaction_request_dnssec_rr(DnsTransaction
*t
, DnsResourceKey
*key
) {
1840 _cleanup_(dns_answer_unrefp
) DnsAnswer
*a
= NULL
;
1841 DnsTransaction
*aux
;
1847 /* Try to get the data from the trust anchor */
1848 r
= dns_trust_anchor_lookup_positive(&t
->scope
->manager
->trust_anchor
, key
, &a
);
1852 r
= dns_answer_extend(&t
->validated_keys
, a
);
1859 /* This didn't work, ask for it via the network/cache then. */
1860 r
= dns_transaction_add_dnssec_transaction(t
, key
, &aux
);
1861 if (r
== -ELOOP
) /* This would result in a cyclic dependency */
1866 if (aux
->state
== DNS_TRANSACTION_NULL
) {
1867 r
= dns_transaction_go(aux
);
1875 static int dns_transaction_negative_trust_anchor_lookup(DnsTransaction
*t
, const char *name
) {
1880 /* Check whether the specified name is in the NTA
1881 * database, either in the global one, or the link-local
1884 r
= dns_trust_anchor_lookup_negative(&t
->scope
->manager
->trust_anchor
, name
);
1888 if (!t
->scope
->link
)
1891 return link_negative_trust_anchor_lookup(t
->scope
->link
, name
);
1894 static int dns_transaction_has_unsigned_negative_answer(DnsTransaction
*t
) {
1899 /* Checks whether the answer is negative, and lacks NSEC/NSEC3
1900 * RRs to prove it */
1902 r
= dns_transaction_has_positive_answer(t
, NULL
);
1908 /* Is this key explicitly listed as a negative trust anchor?
1909 * If so, it's nothing we need to care about */
1910 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
1916 /* The answer does not contain any RRs that match to the
1917 * question. If so, let's see if there are any NSEC/NSEC3 RRs
1918 * included. If not, the answer is unsigned. */
1920 r
= dns_answer_contains_nsec_or_nsec3(t
->answer
);
1929 static int dns_transaction_is_primary_response(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
1935 /* Check if the specified RR is the "primary" response,
1936 * i.e. either matches the question precisely or is a
1937 * CNAME/DNAME for it. */
1939 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
1943 return dns_resource_key_match_cname_or_dname(t
->key
, rr
->key
, NULL
);
1946 static bool dns_transaction_dnssec_supported(DnsTransaction
*t
) {
1949 /* Checks whether our transaction's DNS server is assumed to be compatible with DNSSEC. Returns false as soon
1950 * as we changed our mind about a server, and now believe it is incompatible with DNSSEC. */
1952 if (t
->scope
->protocol
!= DNS_PROTOCOL_DNS
)
1955 /* If we have picked no server, then we are working from the cache or some other source, and DNSSEC might well
1956 * be supported, hence return true. */
1960 /* Note that we do not check the feature level actually used for the transaction but instead the feature level
1961 * the server is known to support currently, as the transaction feature level might be lower than what the
1962 * server actually supports, since we might have downgraded this transaction's feature level because we got a
1963 * SERVFAIL earlier and wanted to check whether downgrading fixes it. */
1965 return dns_server_dnssec_supported(t
->server
);
1968 static bool dns_transaction_dnssec_supported_full(DnsTransaction
*t
) {
1973 /* Checks whether our transaction our any of the auxiliary transactions couldn't do DNSSEC. */
1975 if (!dns_transaction_dnssec_supported(t
))
1978 SET_FOREACH(dt
, t
->dnssec_transactions
)
1979 if (!dns_transaction_dnssec_supported(dt
))
1985 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
) {
1986 DnsResourceRecord
*rr
;
1993 * Retrieve all auxiliary RRs for the answer we got, so that
1994 * we can verify signatures or prove that RRs are rightfully
1995 * unsigned. Specifically:
1997 * - For RRSIG we get the matching DNSKEY
1998 * - For DNSKEY we get the matching DS
1999 * - For unsigned SOA/NS we get the matching DS
2000 * - For unsigned CNAME/DNAME/DS we get the parent SOA RR
2001 * - For other unsigned RRs we get the matching SOA RR
2002 * - For SOA/NS queries with no matching response RR, and no NSEC/NSEC3, the DS RR
2003 * - For DS queries with no matching response RRs, and no NSEC/NSEC3, the parent's SOA RR
2004 * - For other queries with no matching response RRs, and no NSEC/NSEC3, the SOA RR
2007 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2009 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
2010 return 0; /* We only need to validate stuff from the network */
2011 if (!dns_transaction_dnssec_supported(t
))
2012 return 0; /* If we can't do DNSSEC anyway there's no point in getting the auxiliary RRs */
2014 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2016 if (dns_type_is_pseudo(rr
->key
->type
))
2019 /* If this RR is in the negative trust anchor, we don't need to validate it. */
2020 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2026 switch (rr
->key
->type
) {
2028 case DNS_TYPE_RRSIG
: {
2029 /* For each RRSIG we request the matching DNSKEY */
2030 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*dnskey
= NULL
;
2032 /* If this RRSIG is about a DNSKEY RR and the
2033 * signer is the same as the owner, then we
2034 * already have the DNSKEY, and we don't have
2035 * to look for more. */
2036 if (rr
->rrsig
.type_covered
== DNS_TYPE_DNSKEY
) {
2037 r
= dns_name_equal(rr
->rrsig
.signer
, dns_resource_key_name(rr
->key
));
2044 /* If the signer is not a parent of our
2045 * original query, then this is about an
2046 * auxiliary RRset, but not anything we asked
2047 * for. In this case we aren't interested,
2048 * because we don't want to request additional
2049 * RRs for stuff we didn't really ask for, and
2050 * also to avoid request loops, where
2051 * additional RRs from one transaction result
2052 * in another transaction whose additional RRs
2053 * point back to the original transaction, and
2055 r
= dns_name_endswith(dns_resource_key_name(t
->key
), rr
->rrsig
.signer
);
2061 dnskey
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DNSKEY
, rr
->rrsig
.signer
);
2065 log_debug("Requesting DNSKEY to validate transaction %" PRIu16
" (%s, RRSIG with key tag: %" PRIu16
").",
2066 t
->id
, dns_resource_key_name(rr
->key
), rr
->rrsig
.key_tag
);
2067 r
= dns_transaction_request_dnssec_rr(t
, dnskey
);
2073 case DNS_TYPE_DNSKEY
: {
2074 /* For each DNSKEY we request the matching DS */
2075 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2077 /* If the DNSKEY we are looking at is not for
2078 * zone we are interested in, nor any of its
2079 * parents, we aren't interested, and don't
2080 * request it. After all, we don't want to end
2081 * up in request loops, and want to keep
2082 * additional traffic down. */
2084 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2090 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2094 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, DNSKEY with key tag: %" PRIu16
").",
2095 t
->id
, dns_resource_key_name(rr
->key
), dnssec_keytag(rr
, false));
2096 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2105 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*ds
= NULL
;
2107 /* For an unsigned SOA or NS, try to acquire
2108 * the matching DS RR, as we are at a zone cut
2109 * then, and whether a DS exists tells us
2110 * whether the zone is signed. Do so only if
2111 * this RR matches our original question,
2114 r
= dns_resource_key_match_rr(t
->key
, rr
, NULL
);
2118 /* Hmm, so this SOA RR doesn't match our original question. In this case, maybe this is
2119 * a negative reply, and we need the SOA RR's TTL in order to cache a negative entry?
2120 * If so, we need to validate it, too. */
2122 r
= dns_answer_match_key(t
->answer
, t
->key
, NULL
);
2125 if (r
> 0) /* positive reply, we won't need the SOA and hence don't need to validate
2129 /* Only bother with this if the SOA/NS RR we are looking at is actually a parent of
2130 * what we are looking for, otherwise there's no value in it for us. */
2131 r
= dns_name_endswith(dns_resource_key_name(t
->key
), dns_resource_key_name(rr
->key
));
2138 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2144 ds
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_DS
, dns_resource_key_name(rr
->key
));
2148 log_debug("Requesting DS to validate transaction %" PRIu16
" (%s, unsigned SOA/NS RRset).",
2149 t
->id
, dns_resource_key_name(rr
->key
));
2150 r
= dns_transaction_request_dnssec_rr(t
, ds
);
2158 case DNS_TYPE_CNAME
:
2159 case DNS_TYPE_DNAME
: {
2160 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2163 /* CNAMEs and DNAMEs cannot be located at a
2164 * zone apex, hence ask for the parent SOA for
2165 * unsigned CNAME/DNAME RRs, maybe that's the
2166 * apex. But do all that only if this is
2167 * actually a response to our original
2170 * Similar for DS RRs, which are signed when
2171 * the parent SOA is signed. */
2173 r
= dns_transaction_is_primary_response(t
, rr
);
2179 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2185 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2191 name
= dns_resource_key_name(rr
->key
);
2192 r
= dns_name_parent(&name
);
2198 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, name
);
2202 log_debug("Requesting parent SOA to validate transaction %" PRIu16
" (%s, unsigned CNAME/DNAME/DS RRset).",
2203 t
->id
, dns_resource_key_name(rr
->key
));
2204 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2212 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2214 /* For other unsigned RRsets (including
2215 * NSEC/NSEC3!), look for proof the zone is
2216 * unsigned, by requesting the SOA RR of the
2217 * zone. However, do so only if they are
2218 * directly relevant to our original
2221 r
= dns_transaction_is_primary_response(t
, rr
);
2227 r
= dnssec_has_rrsig(t
->answer
, rr
->key
);
2233 soa
= dns_resource_key_new(rr
->key
->class, DNS_TYPE_SOA
, dns_resource_key_name(rr
->key
));
2237 log_debug("Requesting SOA to validate transaction %" PRIu16
" (%s, unsigned non-SOA/NS RRset <%s>).",
2238 t
->id
, dns_resource_key_name(rr
->key
), dns_resource_record_to_string(rr
));
2239 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2246 /* Above, we requested everything necessary to validate what
2247 * we got. Now, let's request what we need to validate what we
2250 r
= dns_transaction_has_unsigned_negative_answer(t
);
2257 name
= dns_resource_key_name(t
->key
);
2259 /* If this was a SOA or NS request, then check if there's a DS RR for the same domain. Note that this
2260 * could also be used as indication that we are not at a zone apex, but in real world setups there are
2261 * too many broken DNS servers (Hello, incapdns.net!) where non-terminal zones return NXDOMAIN even
2262 * though they have further children. If this was a DS request, then it's signed when the parent zone
2263 * is signed, hence ask the parent SOA in that case. If this was any other RR then ask for the SOA RR,
2264 * to see if that is signed. */
2266 if (t
->key
->type
== DNS_TYPE_DS
) {
2267 r
= dns_name_parent(&name
);
2269 type
= DNS_TYPE_SOA
;
2270 log_debug("Requesting parent SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty DS response).",
2271 name
, t
->id
, dns_resource_key_name(t
->key
));
2275 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
)) {
2278 log_debug("Requesting DS (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty SOA/NS response).",
2282 type
= DNS_TYPE_SOA
;
2283 log_debug("Requesting SOA (→ %s) to validate transaction %" PRIu16
" (%s, unsigned empty non-SOA/NS/DS response).",
2288 _cleanup_(dns_resource_key_unrefp
) DnsResourceKey
*soa
= NULL
;
2290 soa
= dns_resource_key_new(t
->key
->class, type
, name
);
2294 r
= dns_transaction_request_dnssec_rr(t
, soa
);
2300 return dns_transaction_dnssec_is_live(t
);
2303 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
) {
2307 /* Invoked whenever any of our auxiliary DNSSEC transactions completed its work. If the state is still PENDING,
2308 we are still in the loop that adds further DNSSEC transactions, hence don't check if we are ready yet. If
2309 the state is VALIDATING however, we should check if we are complete now. */
2311 if (t
->state
== DNS_TRANSACTION_VALIDATING
)
2312 dns_transaction_process_dnssec(t
);
2315 static int dns_transaction_validate_dnskey_by_ds(DnsTransaction
*t
) {
2316 DnsResourceRecord
*rr
;
2321 /* Add all DNSKEY RRs from the answer that are validated by DS
2322 * RRs from the list of validated keys to the list of
2323 * validated keys. */
2325 DNS_ANSWER_FOREACH_IFINDEX(rr
, ifindex
, t
->answer
) {
2327 r
= dnssec_verify_dnskey_by_ds_search(rr
, t
->validated_keys
);
2333 /* If so, the DNSKEY is validated too. */
2334 r
= dns_answer_add_extend(&t
->validated_keys
, rr
, ifindex
, DNS_ANSWER_AUTHENTICATED
);
2342 static int dns_transaction_requires_rrsig(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2348 /* Checks if the RR we are looking for must be signed with an
2349 * RRSIG. This is used for positive responses. */
2351 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2354 if (dns_type_is_pseudo(rr
->key
->type
))
2357 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2363 switch (rr
->key
->type
) {
2365 case DNS_TYPE_RRSIG
:
2366 /* RRSIGs are the signatures themselves, they need no signing. */
2373 /* For SOA or NS RRs we look for a matching DS transaction */
2375 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2377 if (dt
->key
->class != rr
->key
->class)
2379 if (dt
->key
->type
!= DNS_TYPE_DS
)
2382 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2388 /* We found a DS transactions for the SOA/NS
2389 * RRs we are looking at. If it discovered signed DS
2390 * RRs, then we need to be signed, too. */
2392 if (!dt
->answer_authenticated
)
2395 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2398 /* We found nothing that proves this is safe to leave
2399 * this unauthenticated, hence ask inist on
2400 * authentication. */
2405 case DNS_TYPE_CNAME
:
2406 case DNS_TYPE_DNAME
: {
2407 const char *parent
= NULL
;
2411 * CNAME/DNAME RRs cannot be located at a zone apex, hence look directly for the parent SOA.
2413 * DS RRs are signed if the parent is signed, hence also look at the parent SOA
2416 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2418 if (dt
->key
->class != rr
->key
->class)
2420 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2424 parent
= dns_resource_key_name(rr
->key
);
2425 r
= dns_name_parent(&parent
);
2429 if (rr
->key
->type
== DNS_TYPE_DS
)
2432 /* A CNAME/DNAME without a parent? That's sooo weird. */
2433 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG
),
2434 "Transaction %" PRIu16
" claims CNAME/DNAME at root. Refusing.", t
->id
);
2438 r
= dns_name_equal(dns_resource_key_name(dt
->key
), parent
);
2444 return t
->answer_authenticated
;
2453 /* Any other kind of RR (including DNSKEY/NSEC/NSEC3). Let's see if our SOA lookup was authenticated */
2455 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2457 if (dt
->key
->class != rr
->key
->class)
2459 if (dt
->key
->type
!= DNS_TYPE_SOA
)
2462 r
= dns_name_equal(dns_resource_key_name(dt
->key
), dns_resource_key_name(rr
->key
));
2468 /* We found the transaction that was supposed to find
2469 * the SOA RR for us. It was successful, but found no
2470 * RR for us. This means we are not at a zone cut. In
2471 * this case, we require authentication if the SOA
2472 * lookup was authenticated too. */
2473 return t
->answer_authenticated
;
2480 static int dns_transaction_in_private_tld(DnsTransaction
*t
, const DnsResourceKey
*key
) {
2485 /* If DNSSEC downgrade mode is on, checks whether the
2486 * specified RR is one level below a TLD we have proven not to
2487 * exist. In such a case we assume that this is a private
2488 * domain, and permit it.
2490 * This detects cases like the Fritz!Box router networks. Each
2491 * Fritz!Box router serves a private "fritz.box" zone, in the
2492 * non-existing TLD "box". Requests for the "fritz.box" domain
2493 * are served by the router itself, while requests for the
2494 * "box" domain will result in NXDOMAIN.
2496 * Note that this logic is unable to detect cases where a
2497 * router serves a private DNS zone directly under
2498 * non-existing TLD. In such a case we cannot detect whether
2499 * the TLD is supposed to exist or not, as all requests we
2500 * make for it will be answered by the router's zone, and not
2501 * by the root zone. */
2505 if (t
->scope
->dnssec_mode
!= DNSSEC_ALLOW_DOWNGRADE
)
2506 return false; /* In strict DNSSEC mode what doesn't exist, doesn't exist */
2508 tld
= dns_resource_key_name(key
);
2509 r
= dns_name_parent(&tld
);
2513 return false; /* Already the root domain */
2515 if (!dns_name_is_single_label(tld
))
2518 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2520 if (dt
->key
->class != key
->class)
2523 r
= dns_name_equal(dns_resource_key_name(dt
->key
), tld
);
2529 /* We found an auxiliary lookup we did for the TLD. If
2530 * that returned with NXDOMAIN, we know the TLD didn't
2531 * exist, and hence this might be a private zone. */
2533 return dt
->answer_rcode
== DNS_RCODE_NXDOMAIN
;
2539 static int dns_transaction_requires_nsec(DnsTransaction
*t
) {
2540 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
2548 /* Checks if we need to insist on NSEC/NSEC3 RRs for proving
2549 * this negative reply */
2551 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
2554 if (dns_type_is_pseudo(t
->key
->type
))
2557 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(t
->key
));
2563 r
= dns_transaction_in_private_tld(t
, t
->key
);
2567 /* The lookup is from a TLD that is proven not to
2568 * exist, and we are in downgrade mode, hence ignore
2569 * that fact that we didn't get any NSEC RRs. */
2571 log_info("Detected a negative query %s in a private DNS zone, permitting unsigned response.",
2572 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
2576 name
= dns_resource_key_name(t
->key
);
2578 if (t
->key
->type
== DNS_TYPE_DS
) {
2580 /* We got a negative reply for this DS lookup? DS RRs are signed when their parent zone is signed,
2581 * hence check the parent SOA in this case. */
2583 r
= dns_name_parent(&name
);
2589 type
= DNS_TYPE_SOA
;
2591 } else if (IN_SET(t
->key
->type
, DNS_TYPE_SOA
, DNS_TYPE_NS
))
2592 /* We got a negative reply for this SOA/NS lookup? If so, check if there's a DS RR for this */
2595 /* For all other negative replies, check for the SOA lookup */
2596 type
= DNS_TYPE_SOA
;
2598 /* For all other RRs we check the SOA on the same level to see
2599 * if it's signed. */
2601 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2603 if (dt
->key
->class != t
->key
->class)
2605 if (dt
->key
->type
!= type
)
2608 r
= dns_name_equal(dns_resource_key_name(dt
->key
), name
);
2614 return dt
->answer_authenticated
;
2617 /* If in doubt, require NSEC/NSEC3 */
2621 static int dns_transaction_dnskey_authenticated(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2622 DnsResourceRecord
*rrsig
;
2626 /* Checks whether any of the DNSKEYs used for the RRSIGs for
2627 * the specified RRset is authenticated (i.e. has a matching
2630 r
= dns_transaction_negative_trust_anchor_lookup(t
, dns_resource_key_name(rr
->key
));
2636 DNS_ANSWER_FOREACH(rrsig
, t
->answer
) {
2639 r
= dnssec_key_match_rrsig(rr
->key
, rrsig
);
2645 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2647 if (dt
->key
->class != rr
->key
->class)
2650 if (dt
->key
->type
== DNS_TYPE_DNSKEY
) {
2652 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2658 /* OK, we found an auxiliary DNSKEY
2659 * lookup. If that lookup is
2660 * authenticated, report this. */
2662 if (dt
->answer_authenticated
)
2667 } else if (dt
->key
->type
== DNS_TYPE_DS
) {
2669 r
= dns_name_equal(dns_resource_key_name(dt
->key
), rrsig
->rrsig
.signer
);
2675 /* OK, we found an auxiliary DS
2676 * lookup. If that lookup is
2677 * authenticated and non-zero, we
2680 if (!dt
->answer_authenticated
)
2683 return dns_answer_match_key(dt
->answer
, dt
->key
, NULL
);
2688 return found
? false : -ENXIO
;
2691 static int dns_transaction_known_signed(DnsTransaction
*t
, DnsResourceRecord
*rr
) {
2695 /* We know that the root domain is signed, hence if it appears
2696 * not to be signed, there's a problem with the DNS server */
2698 return rr
->key
->class == DNS_CLASS_IN
&&
2699 dns_name_is_root(dns_resource_key_name(rr
->key
));
2702 static int dns_transaction_check_revoked_trust_anchors(DnsTransaction
*t
) {
2703 DnsResourceRecord
*rr
;
2708 /* Maybe warn the user that we encountered a revoked DNSKEY
2709 * for a key from our trust anchor. Note that we don't care
2710 * whether the DNSKEY can be authenticated or not. It's
2711 * sufficient if it is self-signed. */
2713 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2714 r
= dns_trust_anchor_check_revoked(&t
->scope
->manager
->trust_anchor
, rr
, t
->answer
);
2722 static int dns_transaction_invalidate_revoked_keys(DnsTransaction
*t
) {
2728 /* Removes all DNSKEY/DS objects from t->validated_keys that
2729 * our trust anchors database considers revoked. */
2732 DnsResourceRecord
*rr
;
2736 DNS_ANSWER_FOREACH(rr
, t
->validated_keys
) {
2737 r
= dns_trust_anchor_is_revoked(&t
->scope
->manager
->trust_anchor
, rr
);
2741 r
= dns_answer_remove_by_rr(&t
->validated_keys
, rr
);
2755 static int dns_transaction_copy_validated(DnsTransaction
*t
) {
2761 /* Copy all validated RRs from the auxiliary DNSSEC transactions into our set of validated RRs */
2763 SET_FOREACH(dt
, t
->dnssec_transactions
) {
2765 if (DNS_TRANSACTION_IS_LIVE(dt
->state
))
2768 if (!dt
->answer_authenticated
)
2771 r
= dns_answer_extend(&t
->validated_keys
, dt
->answer
);
2780 DNSSEC_PHASE_DNSKEY
, /* Phase #1, only validate DNSKEYs */
2781 DNSSEC_PHASE_NSEC
, /* Phase #2, only validate NSEC+NSEC3 */
2782 DNSSEC_PHASE_ALL
, /* Phase #3, validate everything else */
2785 static int dnssec_validate_records(
2789 DnsAnswer
**validated
) {
2791 DnsResourceRecord
*rr
;
2794 /* Returns negative on error, 0 if validation failed, 1 to restart validation, 2 when finished. */
2796 DNS_ANSWER_FOREACH(rr
, t
->answer
) {
2797 DnsResourceRecord
*rrsig
= NULL
;
2798 DnssecResult result
;
2800 switch (rr
->key
->type
) {
2801 case DNS_TYPE_RRSIG
:
2804 case DNS_TYPE_DNSKEY
:
2805 /* We validate DNSKEYs only in the DNSKEY and ALL phases */
2806 if (phase
== DNSSEC_PHASE_NSEC
)
2811 case DNS_TYPE_NSEC3
:
2814 /* We validate NSEC/NSEC3 only in the NSEC and ALL phases */
2815 if (phase
== DNSSEC_PHASE_DNSKEY
)
2820 /* We validate all other RRs only in the ALL phases */
2821 if (phase
!= DNSSEC_PHASE_ALL
)
2825 r
= dnssec_verify_rrset_search(t
->answer
, rr
->key
, t
->validated_keys
, USEC_INFINITY
, &result
, &rrsig
);
2829 log_debug("Looking at %s: %s", strna(dns_resource_record_to_string(rr
)), dnssec_result_to_string(result
));
2831 if (result
== DNSSEC_VALIDATED
) {
2833 if (rr
->key
->type
== DNS_TYPE_DNSKEY
) {
2834 /* If we just validated a DNSKEY RRset, then let's add these keys to
2835 * the set of validated keys for this transaction. */
2837 r
= dns_answer_copy_by_key(&t
->validated_keys
, t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
);
2841 /* Some of the DNSKEYs we just added might already have been revoked,
2842 * remove them again in that case. */
2843 r
= dns_transaction_invalidate_revoked_keys(t
);
2848 /* Add the validated RRset to the new list of validated
2849 * RRsets, and remove it from the unvalidated RRsets.
2850 * We mark the RRset as authenticated and cacheable. */
2851 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
);
2855 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_SECURE
, rr
->key
);
2857 /* Exit the loop, we dropped something from the answer, start from the beginning */
2861 /* If we haven't read all DNSKEYs yet a negative result of the validation is irrelevant, as
2862 * there might be more DNSKEYs coming. Similar, if we haven't read all NSEC/NSEC3 RRs yet,
2863 * we cannot do positive wildcard proofs yet, as those require the NSEC/NSEC3 RRs. */
2864 if (phase
!= DNSSEC_PHASE_ALL
)
2867 if (result
== DNSSEC_VALIDATED_WILDCARD
) {
2868 bool authenticated
= false;
2871 /* This RRset validated, but as a wildcard. This means we need
2872 * to prove via NSEC/NSEC3 that no matching non-wildcard RR exists. */
2874 /* First step, determine the source of synthesis */
2875 r
= dns_resource_record_source(rrsig
, &source
);
2879 r
= dnssec_test_positive_wildcard(*validated
,
2880 dns_resource_key_name(rr
->key
),
2882 rrsig
->rrsig
.signer
,
2885 /* Unless the NSEC proof showed that the key really doesn't exist something is off. */
2887 result
= DNSSEC_INVALID
;
2889 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
,
2890 authenticated
? (DNS_ANSWER_AUTHENTICATED
|DNS_ANSWER_CACHEABLE
) : 0);
2894 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, rr
->key
);
2896 /* Exit the loop, we dropped something from the answer, start from the beginning */
2901 if (result
== DNSSEC_NO_SIGNATURE
) {
2902 r
= dns_transaction_requires_rrsig(t
, rr
);
2906 /* Data does not require signing. In that case, just copy it over,
2907 * but remember that this is by no means authenticated. */
2908 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2912 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2916 r
= dns_transaction_known_signed(t
, rr
);
2920 /* This is an RR we know has to be signed. If it isn't this means
2921 * the server is not attaching RRSIGs, hence complain. */
2923 dns_server_packet_rrsig_missing(t
->server
, t
->current_feature_level
);
2925 if (t
->scope
->dnssec_mode
== DNSSEC_ALLOW_DOWNGRADE
) {
2927 /* Downgrading is OK? If so, just consider the information unsigned */
2929 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2933 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2937 /* Otherwise, fail */
2938 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
2942 r
= dns_transaction_in_private_tld(t
, rr
->key
);
2946 char s
[DNS_RESOURCE_KEY_STRING_MAX
];
2948 /* The data is from a TLD that is proven not to exist, and we are in downgrade
2949 * mode, hence ignore the fact that this was not signed. */
2951 log_info("Detected RRset %s is in a private DNS zone, permitting unsigned RRs.",
2952 dns_resource_key_to_string(rr
->key
, s
, sizeof s
));
2954 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2958 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2965 DNSSEC_SIGNATURE_EXPIRED
,
2966 DNSSEC_UNSUPPORTED_ALGORITHM
)) {
2968 r
= dns_transaction_dnskey_authenticated(t
, rr
);
2969 if (r
< 0 && r
!= -ENXIO
)
2972 /* The DNSKEY transaction was not authenticated, this means there's
2973 * no DS for this, which means it's OK if no keys are found for this signature. */
2975 r
= dns_answer_move_by_key(validated
, &t
->answer
, rr
->key
, 0);
2979 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, rr
->key
);
2984 r
= dns_transaction_is_primary_response(t
, rr
);
2988 /* Look for a matching DNAME for this CNAME */
2989 r
= dns_answer_has_dname_for_cname(t
->answer
, rr
);
2993 /* Also look among the stuff we already validated */
2994 r
= dns_answer_has_dname_for_cname(*validated
, rr
);
3002 DNSSEC_SIGNATURE_EXPIRED
,
3003 DNSSEC_NO_SIGNATURE
))
3004 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, rr
->key
);
3005 else /* DNSSEC_MISSING_KEY or DNSSEC_UNSUPPORTED_ALGORITHM */
3006 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, rr
->key
);
3008 /* This is a primary response to our question, and it failed validation.
3010 t
->answer_dnssec_result
= result
;
3014 /* This is a primary response, but we do have a DNAME RR
3015 * in the RR that can replay this CNAME, hence rely on
3016 * that, and we can remove the CNAME in favour of it. */
3019 /* This is just some auxiliary data. Just remove the RRset and continue. */
3020 r
= dns_answer_remove_by_key(&t
->answer
, rr
->key
);
3024 /* We dropped something from the answer, start from the beginning. */
3028 return 2; /* Finito. */
3031 int dns_transaction_validate_dnssec(DnsTransaction
*t
) {
3032 _cleanup_(dns_answer_unrefp
) DnsAnswer
*validated
= NULL
;
3034 DnsAnswerFlags flags
;
3036 char key_str
[DNS_RESOURCE_KEY_STRING_MAX
];
3040 /* We have now collected all DS and DNSKEY RRs in
3041 * t->validated_keys, let's see which RRs we can now
3042 * authenticate with that. */
3044 if (t
->scope
->dnssec_mode
== DNSSEC_NO
)
3047 /* Already validated */
3048 if (t
->answer_dnssec_result
!= _DNSSEC_RESULT_INVALID
)
3051 /* Our own stuff needs no validation */
3052 if (IN_SET(t
->answer_source
, DNS_TRANSACTION_ZONE
, DNS_TRANSACTION_TRUST_ANCHOR
)) {
3053 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3054 t
->answer_authenticated
= true;
3058 /* Cached stuff is not affected by validation. */
3059 if (t
->answer_source
!= DNS_TRANSACTION_NETWORK
)
3062 if (!dns_transaction_dnssec_supported_full(t
)) {
3063 /* The server does not support DNSSEC, or doesn't augment responses with RRSIGs. */
3064 t
->answer_dnssec_result
= DNSSEC_INCOMPATIBLE_SERVER
;
3065 log_debug("Not validating response for %" PRIu16
", used server feature level does not support DNSSEC.", t
->id
);
3069 log_debug("Validating response from transaction %" PRIu16
" (%s).",
3071 dns_resource_key_to_string(t
->key
, key_str
, sizeof key_str
));
3073 /* First, see if this response contains any revoked trust
3074 * anchors we care about */
3075 r
= dns_transaction_check_revoked_trust_anchors(t
);
3079 /* Third, copy all RRs we acquired successfully from auxiliary RRs over. */
3080 r
= dns_transaction_copy_validated(t
);
3084 /* Second, see if there are DNSKEYs we already know a
3085 * validated DS for. */
3086 r
= dns_transaction_validate_dnskey_by_ds(t
);
3090 /* Fourth, remove all DNSKEY and DS RRs again that our trust
3091 * anchor says are revoked. After all we might have marked
3092 * some keys revoked above, but they might still be lingering
3093 * in our validated_keys list. */
3094 r
= dns_transaction_invalidate_revoked_keys(t
);
3098 phase
= DNSSEC_PHASE_DNSKEY
;
3100 bool have_nsec
= false;
3102 r
= dnssec_validate_records(t
, phase
, &have_nsec
, &validated
);
3106 /* Try again as long as we managed to achieve something */
3110 if (phase
== DNSSEC_PHASE_DNSKEY
&& have_nsec
) {
3111 /* OK, we processed all DNSKEYs, and there are NSEC/NSEC3 RRs, look at those now. */
3112 phase
= DNSSEC_PHASE_NSEC
;
3116 if (phase
!= DNSSEC_PHASE_ALL
) {
3117 /* OK, we processed all DNSKEYs and NSEC/NSEC3 RRs, look at all the rest now.
3118 * Note that in this third phase we start to remove RRs we couldn't validate. */
3119 phase
= DNSSEC_PHASE_ALL
;
3127 dns_answer_unref(t
->answer
);
3128 t
->answer
= TAKE_PTR(validated
);
3130 /* At this point the answer only contains validated
3131 * RRsets. Now, let's see if it actually answers the question
3132 * we asked. If so, great! If it doesn't, then see if
3133 * NSEC/NSEC3 can prove this. */
3134 r
= dns_transaction_has_positive_answer(t
, &flags
);
3136 /* Yes, it answers the question! */
3138 if (flags
& DNS_ANSWER_AUTHENTICATED
) {
3139 /* The answer is fully authenticated, yay. */
3140 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3141 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3142 t
->answer_authenticated
= true;
3144 /* The answer is not fully authenticated. */
3145 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3146 t
->answer_authenticated
= false;
3149 } else if (r
== 0) {
3150 DnssecNsecResult nr
;
3151 bool authenticated
= false;
3153 /* Bummer! Let's check NSEC/NSEC3 */
3154 r
= dnssec_nsec_test(t
->answer
, t
->key
, &nr
, &authenticated
, &t
->answer_nsec_ttl
);
3160 case DNSSEC_NSEC_NXDOMAIN
:
3161 /* NSEC proves the domain doesn't exist. Very good. */
3162 log_debug("Proved NXDOMAIN via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3163 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3164 t
->answer_rcode
= DNS_RCODE_NXDOMAIN
;
3165 t
->answer_authenticated
= authenticated
;
3167 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3170 case DNSSEC_NSEC_NODATA
:
3171 /* NSEC proves that there's no data here, very good. */
3172 log_debug("Proved NODATA via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3173 t
->answer_dnssec_result
= DNSSEC_VALIDATED
;
3174 t
->answer_rcode
= DNS_RCODE_SUCCESS
;
3175 t
->answer_authenticated
= authenticated
;
3177 manager_dnssec_verdict(t
->scope
->manager
, authenticated
? DNSSEC_SECURE
: DNSSEC_INSECURE
, t
->key
);
3180 case DNSSEC_NSEC_OPTOUT
:
3181 /* NSEC3 says the data might not be signed */
3182 log_debug("Data is NSEC3 opt-out via NSEC/NSEC3 for transaction %u (%s)", t
->id
, key_str
);
3183 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3184 t
->answer_authenticated
= false;
3186 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3189 case DNSSEC_NSEC_NO_RR
:
3190 /* No NSEC data? Bummer! */
3192 r
= dns_transaction_requires_nsec(t
);
3196 t
->answer_dnssec_result
= DNSSEC_NO_SIGNATURE
;
3197 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3199 t
->answer_dnssec_result
= DNSSEC_UNSIGNED
;
3200 t
->answer_authenticated
= false;
3201 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INSECURE
, t
->key
);
3206 case DNSSEC_NSEC_UNSUPPORTED_ALGORITHM
:
3207 /* We don't know the NSEC3 algorithm used? */
3208 t
->answer_dnssec_result
= DNSSEC_UNSUPPORTED_ALGORITHM
;
3209 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_INDETERMINATE
, t
->key
);
3212 case DNSSEC_NSEC_FOUND
:
3213 case DNSSEC_NSEC_CNAME
:
3214 /* NSEC says it needs to be there, but we couldn't find it? Bummer! */
3215 t
->answer_dnssec_result
= DNSSEC_NSEC_MISMATCH
;
3216 manager_dnssec_verdict(t
->scope
->manager
, DNSSEC_BOGUS
, t
->key
);
3220 assert_not_reached("Unexpected NSEC result.");
3227 static const char* const dns_transaction_state_table
[_DNS_TRANSACTION_STATE_MAX
] = {
3228 [DNS_TRANSACTION_NULL
] = "null",
3229 [DNS_TRANSACTION_PENDING
] = "pending",
3230 [DNS_TRANSACTION_VALIDATING
] = "validating",
3231 [DNS_TRANSACTION_RCODE_FAILURE
] = "rcode-failure",
3232 [DNS_TRANSACTION_SUCCESS
] = "success",
3233 [DNS_TRANSACTION_NO_SERVERS
] = "no-servers",
3234 [DNS_TRANSACTION_TIMEOUT
] = "timeout",
3235 [DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
] = "attempts-max-reached",
3236 [DNS_TRANSACTION_INVALID_REPLY
] = "invalid-reply",
3237 [DNS_TRANSACTION_ERRNO
] = "errno",
3238 [DNS_TRANSACTION_ABORTED
] = "aborted",
3239 [DNS_TRANSACTION_DNSSEC_FAILED
] = "dnssec-failed",
3240 [DNS_TRANSACTION_NO_TRUST_ANCHOR
] = "no-trust-anchor",
3241 [DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
] = "rr-type-unsupported",
3242 [DNS_TRANSACTION_NETWORK_DOWN
] = "network-down",
3243 [DNS_TRANSACTION_NOT_FOUND
] = "not-found",
3245 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_state
, DnsTransactionState
);
3247 static const char* const dns_transaction_source_table
[_DNS_TRANSACTION_SOURCE_MAX
] = {
3248 [DNS_TRANSACTION_NETWORK
] = "network",
3249 [DNS_TRANSACTION_CACHE
] = "cache",
3250 [DNS_TRANSACTION_ZONE
] = "zone",
3251 [DNS_TRANSACTION_TRUST_ANCHOR
] = "trust-anchor",
3253 DEFINE_STRING_TABLE_LOOKUP(dns_transaction_source
, DnsTransactionSource
);