0db643664c
With access to the server when creating the socket, we can connect() to the server and hence simplify message sending and receiving in follow-up patches.
117 lines
3.8 KiB
C
117 lines
3.8 KiB
C
/*-*- 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-scope.h"
|
|
#include "resolved-dns-packet.h"
|
|
#include "resolved-dns-question.h"
|
|
#include "resolved-dns-answer.h"
|
|
|
|
struct DnsTransaction {
|
|
DnsScope *scope;
|
|
|
|
DnsQuestion *question;
|
|
|
|
DnsTransactionState state;
|
|
uint16_t id;
|
|
|
|
bool initial_jitter;
|
|
|
|
DnsPacket *sent, *received;
|
|
DnsAnswer *cached;
|
|
int cached_rcode;
|
|
|
|
sd_event_source *timeout_event_source;
|
|
unsigned n_attempts;
|
|
|
|
int dns_fd;
|
|
sd_event_source *dns_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, DnsQuestion *q);
|
|
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);
|
|
|
|
int transaction_dns_fd(DnsTransaction *t, DnsServer **server);
|
|
|
|
const char* dns_transaction_state_to_string(DnsTransactionState p) _const_;
|
|
DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_;
|
|
|
|
/* After how much time to repeat classic DNS requests */
|
|
#define DNS_TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC)
|
|
|
|
/* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */
|
|
#define LLMNR_TRANSACTION_TIMEOUT_USEC (1 * USEC_PER_SEC)
|
|
|
|
/* 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 8
|
|
|
|
/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */
|
|
#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3
|
|
|
|
#define TRANSACTION_TIMEOUT_USEC(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_TIMEOUT_USEC : DNS_TRANSACTION_TIMEOUT_USEC)
|
|
#define TRANSACTION_ATTEMPTS_MAX(p) (p == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX)
|