conn.c File Reference

#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <sys/socket.h>
#include <unistd.h>
#include "config.h"
#include "conn.h"
#include "constants.h"
#include "lru_cache.h"
#include "query.h"
#include "utils.h"

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Functions
static char *	listener_err_to_str (int err)
void	conn_tcp_release (conn_tcp_t *conn_tcp)
void	conn_udp_release (conn_udp_t *conn_udp)
void	conn_release (conn_t *conn)
conn_t *	conn_new_tcp (int fd, config_t *cfg, int ip_version, struct sockaddr_storage *client_ip, struct sockaddr_storage *local_ip)
conn_udp_t *	conn_udp_new (config_t *cfg, int family)
void	conn_udp_vectors_reset (conn_udp_t *conn_udp)
static int	listener_start (config_t *cfg, int family, int protocol, int *err_no)
conn_t *	conn_listener_provision (config_t *cfg, int family, int protocol, char *err_buf, size_t err_buf_len)
void	conn_fifo_enqueue_read (conn_fifo_queue_t *queue, conn_t *conn)
conn_t *	conn_fifo_dequeue_read (conn_fifo_queue_t *queue)
void	conn_fifo_enqueue_gen (conn_fifo_queue_t *queue, conn_t *conn)
conn_t *	conn_fifo_dequeue_gen (conn_fifo_queue_t *queue)
void	conn_fifo_enqueue_write (conn_fifo_queue_t *queue, conn_t *conn)
conn_t *	conn_fifo_dequeue_write (conn_fifo_queue_t *queue)
void	conn_fifo_enqueue_release (conn_fifo_queue_t *queue, conn_t *conn)
conn_t *	conn_fifo_dequeue_release (conn_fifo_queue_t *queue)
void	conn_fifo_remove_from_read_queue (conn_fifo_queue_t *queue, conn_t *conn_rm)
void	conn_fifo_remove_from_write_queue (conn_fifo_queue_t *queue, conn_t *conn_rm)
conn_t *	conn_lru_cache_get (conn_t **lru, uint64_t id)
bool	conn_tcp_id_assign (uint64_t *id, conn_t **lru, uint64_t *base)

Detailed Description

Author

Faruk Grozdanic

Copyright

Released under MIT license.

Copyright (c) 2025 Faruk Grozdanic

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Function Documentation

listener_err_to_str()

static char * listener_err_to_str ( int  err )

static

Function returns string matching a listener error enumerated by listener_start_error_t.

Parameters

err	ID to return string message for.

Returns

String matching error id. String returned is a constant.

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listener_start()

static int listener_start ( config_t *  cfg, int  family, int  protocol, int *  err_no  )

static

Start a TCP or UDP DNS listener.

Starts a listener for given IP family and protocol. Socket is created and socket options set. If protocol is TCP listen() is called to start listening for new TCP connections on socket.

Parameters

cfg	Configuration object that has settings: tcp_listener_port, tcp_writebuff_size, tcp_listener_port, -tcp_listener_pending_conns_max, udp_socket_recvbuff_size, udp_socket_sendbuff_size, udp_listener_port.
family	IP family to start a listener for, valid options are: AF_INET, AF_INET6.
protocol	Protocol to start listener for, valid options are: IPPROTO_TCP, IPPROTO_UDP.
err_no	Where to store value of errno if error was encountered.

Returns

On success returns a socket descriptor for started listener. On error returns negative number representing error. Errors are of enum type listener_start_error_t: typedef enum listener_start_error_e { LISTENER_ERR_SOCKET = -1, LISTENER_ERR_SOCKET_OPT_REUSEADDR = -2, LISTENER_ERR_SOCKET_OPT_REUSEPORT = -3, LISTENER_ERR_BIND = -4, LISTENER_ERR_LISTEN = -5, LISTENER_ERR_MALLOC = -6, LISTENER_ERR_SOCKET_OPT_IP_PKTINFO = -7, LISTENER_ERR_SOCKET_OPT_IPV6_V6ONLY = -8, LISTENER_ERR_SOCKET_OPT_IPV6_RECVPKTINFO = -9, } listener_start_error_t;

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