/* SPDX-License-Identifier: LGPL-2.1+ */ #pragma once /*** This file is part of systemd. Copyright 2014 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . ***/ typedef struct DnsTransaction DnsTransaction; typedef enum DnsTransactionState DnsTransactionState; typedef enum DnsTransactionSource DnsTransactionSource; enum DnsTransactionState { DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING, DNS_TRANSACTION_RCODE_FAILURE, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NO_SERVERS, DNS_TRANSACTION_TIMEOUT, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, DNS_TRANSACTION_INVALID_REPLY, DNS_TRANSACTION_ERRNO, DNS_TRANSACTION_ABORTED, DNS_TRANSACTION_DNSSEC_FAILED, DNS_TRANSACTION_NO_TRUST_ANCHOR, DNS_TRANSACTION_RR_TYPE_UNSUPPORTED, DNS_TRANSACTION_NETWORK_DOWN, DNS_TRANSACTION_NOT_FOUND, /* like NXDOMAIN, but when LLMNR/TCP connections fail */ _DNS_TRANSACTION_STATE_MAX, _DNS_TRANSACTION_STATE_INVALID = -1 }; #define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING) enum DnsTransactionSource { DNS_TRANSACTION_NETWORK, DNS_TRANSACTION_CACHE, DNS_TRANSACTION_ZONE, DNS_TRANSACTION_TRUST_ANCHOR, _DNS_TRANSACTION_SOURCE_MAX, _DNS_TRANSACTION_SOURCE_INVALID = -1 }; #include "resolved-dns-answer.h" #include "resolved-dns-packet.h" #include "resolved-dns-question.h" #include "resolved-dns-scope.h" #include "resolved-dns-server.h" #include "resolved-dns-stream.h" struct DnsTransaction { DnsScope *scope; DnsResourceKey *key; DnsTransactionState state; uint16_t id; bool tried_stream:1; bool initial_jitter_scheduled:1; bool initial_jitter_elapsed:1; bool clamp_ttl:1; bool probing:1; DnsPacket *sent, *received; DnsAnswer *answer; int answer_rcode; DnssecResult answer_dnssec_result; DnsTransactionSource answer_source; uint32_t answer_nsec_ttl; int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */ /* Indicates whether the primary answer is authenticated, * i.e. whether the RRs from answer which directly match the * question are authenticated, or, if there are none, whether * the NODATA or NXDOMAIN case is. It says nothing about * additional RRs listed in the answer, however they have * their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit * is defined different than the AD bit in DNS packets, as * that covers more than just the actual primary answer. */ bool answer_authenticated; /* Contains DNSKEY, DS, SOA RRs we already verified and need * to authenticate this reply */ DnsAnswer *validated_keys; usec_t start_usec; usec_t next_attempt_after; sd_event_source *timeout_event_source; unsigned n_attempts; /* UDP connection logic, if we need it */ int dns_udp_fd; sd_event_source *dns_udp_event_source; /* TCP connection logic, if we need it */ DnsStream *stream; /* The active server */ DnsServer *server; /* The features of the DNS server at time of transaction start */ DnsServerFeatureLevel current_feature_level; /* If we got SERVFAIL back, we retry the lookup, using a lower feature level than we used before. */ DnsServerFeatureLevel clamp_feature_level; /* Query candidates this transaction is referenced by and that * shall be notified about this specific transaction * completing. */ Set *notify_query_candidates, *notify_query_candidates_done; /* Zone items this transaction is referenced by and that shall * be notified about completion. */ Set *notify_zone_items, *notify_zone_items_done; /* Other transactions that this transactions is referenced by * and that shall be notified about completion. This is used * when transactions want to validate their RRsets, but need * another DNSKEY or DS RR to do so. */ Set *notify_transactions, *notify_transactions_done; /* The opposite direction: the transactions this transaction * created in order to request DNSKEY or DS RRs. */ Set *dnssec_transactions; unsigned block_gc; LIST_FIELDS(DnsTransaction, transactions_by_scope); }; int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key); DnsTransaction* dns_transaction_free(DnsTransaction *t); bool dns_transaction_gc(DnsTransaction *t); int dns_transaction_go(DnsTransaction *t); void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p); void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state); void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source); int dns_transaction_validate_dnssec(DnsTransaction *t); int dns_transaction_request_dnssec_keys(DnsTransaction *t); const char* dns_transaction_state_to_string(DnsTransactionState p) _const_; DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_; const char* dns_transaction_source_to_string(DnsTransactionSource p) _const_; DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_; /* LLMNR Jitter interval, see RFC 4795 Section 7 */ #define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC) /* mDNS Jitter interval, see RFC 6762 Section 5.2 */ #define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC) #define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC) /* mDNS probing interval, see RFC 6762 Section 8.1 */ #define MDNS_PROBING_INTERVAL_USEC (250 * USEC_PER_MSEC) /* Maximum attempts to send DNS requests, across all DNS servers */ #define DNS_TRANSACTION_ATTEMPTS_MAX 24 /* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ #define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 /* Maximum attempts to send MDNS requests, see RFC 6762 Section 8.1 */ #define MDNS_TRANSACTION_ATTEMPTS_MAX 3 #define TRANSACTION_ATTEMPTS_MAX(p) (((p) == DNS_PROTOCOL_LLMNR) ? \ LLMNR_TRANSACTION_ATTEMPTS_MAX : \ (((p) == DNS_PROTOCOL_MDNS) ? \ MDNS_TRANSACTION_ATTEMPTS_MAX : \ DNS_TRANSACTION_ATTEMPTS_MAX))