/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ #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 <http://www.gnu.org/licenses/>. ***/ typedef struct DnsTransaction DnsTransaction; typedef enum DnsTransactionState DnsTransactionState; enum DnsTransactionState { DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_FAILURE, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_NO_SERVERS, DNS_TRANSACTION_TIMEOUT, DNS_TRANSACTION_ATTEMPTS_MAX_REACHED, DNS_TRANSACTION_INVALID_REPLY, DNS_TRANSACTION_RESOURCES, DNS_TRANSACTION_ABORTED, _DNS_TRANSACTION_STATE_MAX, _DNS_TRANSACTION_STATE_INVALID = -1 }; #include "resolved-dns-answer.h" #include "resolved-dns-packet.h" #include "resolved-dns-question.h" #include "resolved-dns-scope.h" struct DnsTransaction { DnsScope *scope; DnsResourceKey *key; DnsTransactionState state; uint16_t id; bool initial_jitter; DnsPacket *sent, *received; DnsAnswer *cached; int cached_rcode; usec_t start_usec; sd_event_source *timeout_event_source; unsigned n_attempts; int dns_udp_fd; sd_event_source *dns_udp_event_source; /* The active server */ DnsServer *server; /* TCP connection logic, if we need it */ DnsStream *stream; /* Queries this transaction is referenced by and that shall be * notified about this specific transaction completing. */ Set *queries; /* Zone items this transaction is referenced by and that shall * be notified about completion. */ Set *zone_items; 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); void 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); const char* dns_transaction_state_to_string(DnsTransactionState p) _const_; DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_; /* LLMNR Jitter interval, see RFC 4795 Section 7 */ #define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC) /* Maximum attempts to send DNS requests, across all DNS servers */ #define DNS_TRANSACTION_ATTEMPTS_MAX 16 /* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */ #define LLMNR_TRANSACTION_ATTEMPTS_MAX 3 #define TRANSACTION_ATTEMPTS_MAX(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX)