1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
6 This file is part of systemd.
8 Copyright 2014 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 typedef struct DnsTransaction DnsTransaction
;
25 typedef enum DnsTransactionState DnsTransactionState
;
26 typedef enum DnsTransactionSource DnsTransactionSource
;
28 enum DnsTransactionState
{
30 DNS_TRANSACTION_PENDING
,
31 DNS_TRANSACTION_VALIDATING
,
32 DNS_TRANSACTION_RCODE_FAILURE
,
33 DNS_TRANSACTION_SUCCESS
,
34 DNS_TRANSACTION_NO_SERVERS
,
35 DNS_TRANSACTION_TIMEOUT
,
36 DNS_TRANSACTION_ATTEMPTS_MAX_REACHED
,
37 DNS_TRANSACTION_INVALID_REPLY
,
38 DNS_TRANSACTION_RESOURCES
,
39 DNS_TRANSACTION_ABORTED
,
40 DNS_TRANSACTION_DNSSEC_FAILED
,
41 DNS_TRANSACTION_NO_TRUST_ANCHOR
,
42 DNS_TRANSACTION_RR_TYPE_UNSUPPORTED
,
43 _DNS_TRANSACTION_STATE_MAX
,
44 _DNS_TRANSACTION_STATE_INVALID
= -1
47 #define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)
49 enum DnsTransactionSource
{
50 DNS_TRANSACTION_NETWORK
,
51 DNS_TRANSACTION_CACHE
,
53 DNS_TRANSACTION_TRUST_ANCHOR
,
54 _DNS_TRANSACTION_SOURCE_MAX
,
55 _DNS_TRANSACTION_SOURCE_INVALID
= -1
58 #include "resolved-dns-answer.h"
59 #include "resolved-dns-packet.h"
60 #include "resolved-dns-question.h"
61 #include "resolved-dns-scope.h"
63 struct DnsTransaction
{
69 DnsTransactionState state
;
75 bool initial_jitter_scheduled
:1;
76 bool initial_jitter_elapsed
:1;
78 DnsPacket
*sent
, *received
;
82 DnssecResult answer_dnssec_result
;
83 DnsTransactionSource answer_source
;
84 uint32_t answer_nsec_ttl
;
86 /* Indicates whether the primary answer is authenticated,
87 * i.e. whether the RRs from answer which directly match the
88 * question are authenticated, or, if there are none, whether
89 * the NODATA or NXDOMAIN case is. It says nothing about
90 * additional RRs listed in the answer, however they have
91 * their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit
92 * is defined different than the AD bit in DNS packets, as
93 * that covers more than just the actual primary answer. */
94 bool answer_authenticated
;
96 /* Contains DNSKEY, DS, SOA RRs we already verified and need
97 * to authenticate this reply */
98 DnsAnswer
*validated_keys
;
101 usec_t next_attempt_after
;
102 sd_event_source
*timeout_event_source
;
105 /* UDP connection logic, if we need it */
107 sd_event_source
*dns_udp_event_source
;
109 /* TCP connection logic, if we need it */
112 /* The active server */
115 /* The features of the DNS server at time of transaction start */
116 DnsServerFeatureLevel current_features
;
118 /* Query candidates this transaction is referenced by and that
119 * shall be notified about this specific transaction
121 Set
*notify_query_candidates
;
123 /* Zone items this transaction is referenced by and that shall
124 * be notified about completion. */
125 Set
*notify_zone_items
;
127 /* Other transactions that this transactions is referenced by
128 * and that shall be notified about completion. This is used
129 * when transactions want to validate their RRsets, but need
130 * another DNSKEY or DS RR to do so. */
131 Set
*notify_transactions
;
133 /* The opposite direction: the transactions this transaction
134 * created in order to request DNSKEY or DS RRs. */
135 Set
*dnssec_transactions
;
139 LIST_FIELDS(DnsTransaction
, transactions_by_scope
);
142 int dns_transaction_new(DnsTransaction
**ret
, DnsScope
*s
, DnsResourceKey
*key
);
143 DnsTransaction
* dns_transaction_free(DnsTransaction
*t
);
145 bool dns_transaction_gc(DnsTransaction
*t
);
146 int dns_transaction_go(DnsTransaction
*t
);
148 void dns_transaction_process_reply(DnsTransaction
*t
, DnsPacket
*p
);
149 void dns_transaction_complete(DnsTransaction
*t
, DnsTransactionState state
);
151 void dns_transaction_notify(DnsTransaction
*t
, DnsTransaction
*source
);
152 int dns_transaction_validate_dnssec(DnsTransaction
*t
);
153 int dns_transaction_request_dnssec_keys(DnsTransaction
*t
);
155 const char *dns_transaction_key_string(DnsTransaction
*t
);
157 const char* dns_transaction_state_to_string(DnsTransactionState p
) _const_
;
158 DnsTransactionState
dns_transaction_state_from_string(const char *s
) _pure_
;
160 const char* dns_transaction_source_to_string(DnsTransactionSource p
) _const_
;
161 DnsTransactionSource
dns_transaction_source_from_string(const char *s
) _pure_
;
163 /* LLMNR Jitter interval, see RFC 4795 Section 7 */
164 #define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC)
166 /* mDNS Jitter interval, see RFC 6762 Section 5.2 */
167 #define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC)
168 #define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC)
170 /* Maximum attempts to send DNS requests, across all DNS servers */
171 #define DNS_TRANSACTION_ATTEMPTS_MAX 16
173 /* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */
174 #define LLMNR_TRANSACTION_ATTEMPTS_MAX 3
176 #define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX)