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/*
* services/listen_dnsport.h - listen on port 53 for incoming DNS queries.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file has functions to get queries from clients.
*/
#ifndef LISTEN_DNSPORT_H
#define LISTEN_DNSPORT_H
#include "util/netevent.h"
struct listen_list;
struct config_file;
struct addrinfo;
struct sldns_buffer;
/**
* Listening for queries structure.
* Contains list of query-listen sockets.
*/
struct listen_dnsport {
/** Base for select calls */
struct comm_base* base;
/** buffer shared by UDP connections, since there is only one
datagram at any time. */
struct sldns_buffer* udp_buff;
/** list of comm points used to get incoming events */
struct listen_list* cps;
};
/**
* Single linked list to store event points.
*/
struct listen_list {
/** next in list */
struct listen_list* next;
/** event info */
struct comm_point* com;
};
/**
* type of ports
*/
enum listen_type {
/** udp type */
listen_type_udp,
/** tcp type */
listen_type_tcp,
/** udp ipv6 (v4mapped) for use with ancillary data */
listen_type_udpancil,
/** ssl over tcp type */
listen_type_ssl
};
/**
* Single linked list to store shared ports that have been
* opened for use by all threads.
*/
struct listen_port {
/** next in list */
struct listen_port* next;
/** file descriptor, open and ready for use */
int fd;
/** type of file descriptor, udp or tcp */
enum listen_type ftype;
};
/**
* Create shared listening ports
* Getaddrinfo, create socket, bind and listen to zero or more
* interfaces for IP4 and/or IP6, for UDP and/or TCP.
* On the given port number. It creates the sockets.
* @param cfg: settings on what ports to open.
* @param reuseport: set to true if you want reuseport, or NULL to not have it,
* set to false on exit if reuseport failed to apply (because of no
* kernel support).
* @return: linked list of ports or NULL on error.
*/
struct listen_port* listening_ports_open(struct config_file* cfg,
int* reuseport);
/**
* Close and delete the (list of) listening ports.
*/
void listening_ports_free(struct listen_port* list);
/**
* Create commpoints with for this thread for the shared ports.
* @param base: the comm_base that provides event functionality.
* for default all ifs.
* @param ports: the list of shared ports.
* @param bufsize: size of datagram buffer.
* @param tcp_accept_count: max number of simultaneous TCP connections
* from clients.
* @param sslctx: nonNULL if ssl context.
* @param dtenv: nonNULL if dnstap enabled.
* @param cb: callback function when a request arrives. It is passed
* the packet and user argument. Return true to send a reply.
* @param cb_arg: user data argument for callback function.
* @return: the malloced listening structure, ready for use. NULL on error.
*/
struct listen_dnsport* listen_create(struct comm_base* base,
struct listen_port* ports, size_t bufsize, int tcp_accept_count,
void* sslctx, struct dt_env *dtenv, comm_point_callback_t* cb,
void* cb_arg);
/**
* delete the listening structure
* @param listen: listening structure.
*/
void listen_delete(struct listen_dnsport* listen);
/**
* delete listen_list of commpoints. Calls commpointdelete() on items.
* This may close the fds or not depending on flags.
* @param list: to delete.
*/
void listen_list_delete(struct listen_list* list);
/**
* get memory size used by the listening structs
* @param listen: listening structure.
* @return: size in bytes.
*/
size_t listen_get_mem(struct listen_dnsport* listen);
/**
* stop accept handlers for TCP (until enabled again)
* @param listen: listening structure.
*/
void listen_stop_accept(struct listen_dnsport* listen);
/**
* start accept handlers for TCP (was stopped before)
* @param listen: listening structure.
*/
void listen_start_accept(struct listen_dnsport* listen);
/**
* Create and bind nonblocking UDP socket
* @param family: for socket call.
* @param socktype: for socket call.
* @param addr: for bind call.
* @param addrlen: for bind call.
* @param v6only: if enabled, IP6 sockets get IP6ONLY option set.
* if enabled with value 2 IP6ONLY option is disabled.
* @param inuse: on error, this is set true if the port was in use.
* @param noproto: on error, this is set true if cause is that the
IPv6 proto (family) is not available.
* @param rcv: set size on rcvbuf with socket option, if 0 it is not set.
* @param snd: set size on sndbuf with socket option, if 0 it is not set.
* @param listen: if true, this is a listening UDP port, eg port 53, and
* set SO_REUSEADDR on it.
* @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
* listening UDP port. Set to false on return if it failed to do so.
* @param transparent: set IP_TRANSPARENT socket option.
* @param freebind: set IP_FREEBIND socket option.
* @return: the socket. -1 on error.
*/
int create_udp_sock(int family, int socktype, struct sockaddr* addr,
socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv,
int snd, int listen, int* reuseport, int transparent, int freebind);
/**
* Create and bind TCP listening socket
* @param addr: address info ready to make socket.
* @param v6only: enable ip6 only flag on ip6 sockets.
* @param noproto: if error caused by lack of protocol support.
* @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
* listening UDP port. Set to false on return if it failed to do so.
* @param transparent: set IP_TRANSPARENT socket option.
* @param mss: maximum segment size of the socket. if zero, leaves the default.
* @param freebind: set IP_FREEBIND socket option.
* @return: the socket. -1 on error.
*/
int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto,
int* reuseport, int transparent, int mss, int freebind);
/**
* Create and bind local listening socket
* @param path: path to the socket.
* @param noproto: on error, this is set true if cause is that local sockets
* are not supported.
* @return: the socket. -1 on error.
*/
int create_local_accept_sock(const char* path, int* noproto);
#endif /* LISTEN_DNSPORT_H */
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