/* * 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. * @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); /** * 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. * @return: the socket. -1 on error. */ int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto, int* reuseport); #endif /* LISTEN_DNSPORT_H */