1 /* 2 * services/listen_dnsport.h - listen on port 53 for incoming DNS queries. 3 * 4 * Copyright (c) 2007, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * 39 * This file has functions to get queries from clients. 40 */ 41 42 #ifndef LISTEN_DNSPORT_H 43 #define LISTEN_DNSPORT_H 44 45 #include "util/netevent.h" 46 struct listen_list; 47 struct config_file; 48 struct addrinfo; 49 50 /** 51 * Listening for queries structure. 52 * Contains list of query-listen sockets. 53 */ 54 struct listen_dnsport { 55 /** Base for select calls */ 56 struct comm_base* base; 57 58 /** buffer shared by UDP connections, since there is only one 59 datagram at any time. */ 60 ldns_buffer* udp_buff; 61 62 /** list of comm points used to get incoming events */ 63 struct listen_list* cps; 64 }; 65 66 /** 67 * Single linked list to store event points. 68 */ 69 struct listen_list { 70 /** next in list */ 71 struct listen_list* next; 72 /** event info */ 73 struct comm_point* com; 74 }; 75 76 /** 77 * type of ports 78 */ 79 enum listen_type { 80 /** udp type */ 81 listen_type_udp, 82 /** tcp type */ 83 listen_type_tcp, 84 /** udp ipv6 (v4mapped) for use with ancillary data */ 85 listen_type_udpancil, 86 /** ssl over tcp type */ 87 listen_type_ssl 88 }; 89 90 /** 91 * Single linked list to store shared ports that have been 92 * opened for use by all threads. 93 */ 94 struct listen_port { 95 /** next in list */ 96 struct listen_port* next; 97 /** file descriptor, open and ready for use */ 98 int fd; 99 /** type of file descriptor, udp or tcp */ 100 enum listen_type ftype; 101 }; 102 103 /** 104 * Create shared listening ports 105 * Getaddrinfo, create socket, bind and listen to zero or more 106 * interfaces for IP4 and/or IP6, for UDP and/or TCP. 107 * On the given port number. It creates the sockets. 108 * @param cfg: settings on what ports to open. 109 * @return: linked list of ports or NULL on error. 110 */ 111 struct listen_port* listening_ports_open(struct config_file* cfg); 112 113 /** 114 * Close and delete the (list of) listening ports. 115 */ 116 void listening_ports_free(struct listen_port* list); 117 118 /** 119 * Create commpoints with for this thread for the shared ports. 120 * @param base: the comm_base that provides event functionality. 121 * for default all ifs. 122 * @param ports: the list of shared ports. 123 * @param bufsize: size of datagram buffer. 124 * @param tcp_accept_count: max number of simultaneous TCP connections 125 * from clients. 126 * @param sslctx: nonNULL if ssl context. 127 * @param cb: callback function when a request arrives. It is passed 128 * the packet and user argument. Return true to send a reply. 129 * @param cb_arg: user data argument for callback function. 130 * @return: the malloced listening structure, ready for use. NULL on error. 131 */ 132 struct listen_dnsport* listen_create(struct comm_base* base, 133 struct listen_port* ports, size_t bufsize, int tcp_accept_count, 134 void* sslctx, comm_point_callback_t* cb, void* cb_arg); 135 136 /** 137 * delete the listening structure 138 * @param listen: listening structure. 139 */ 140 void listen_delete(struct listen_dnsport* listen); 141 142 /** 143 * delete listen_list of commpoints. Calls commpointdelete() on items. 144 * This may close the fds or not depending on flags. 145 * @param list: to delete. 146 */ 147 void listen_list_delete(struct listen_list* list); 148 149 /** 150 * get memory size used by the listening structs 151 * @param listen: listening structure. 152 * @return: size in bytes. 153 */ 154 size_t listen_get_mem(struct listen_dnsport* listen); 155 156 /** 157 * stop accept handlers for TCP (until enabled again) 158 * @param listen: listening structure. 159 */ 160 void listen_stop_accept(struct listen_dnsport* listen); 161 162 /** 163 * start accept handlers for TCP (was stopped before) 164 * @param listen: listening structure. 165 */ 166 void listen_start_accept(struct listen_dnsport* listen); 167 168 /** 169 * Create and bind nonblocking UDP socket 170 * @param family: for socket call. 171 * @param socktype: for socket call. 172 * @param addr: for bind call. 173 * @param addrlen: for bind call. 174 * @param v6only: if enabled, IP6 sockets get IP6ONLY option set. 175 * if enabled with value 2 IP6ONLY option is disabled. 176 * @param inuse: on error, this is set true if the port was in use. 177 * @param noproto: on error, this is set true if cause is that the 178 IPv6 proto (family) is not available. 179 * @param rcv: set size on rcvbuf with socket option, if 0 it is not set. 180 * @param snd: set size on sndbuf with socket option, if 0 it is not set. 181 * @return: the socket. -1 on error. 182 */ 183 int create_udp_sock(int family, int socktype, struct sockaddr* addr, 184 socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv, 185 int snd); 186 187 /** 188 * Create and bind TCP listening socket 189 * @param addr: address info ready to make socket. 190 * @param v6only: enable ip6 only flag on ip6 sockets. 191 * @param noproto: if error caused by lack of protocol support. 192 * @return: the socket. -1 on error. 193 */ 194 int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto); 195 196 #endif /* LISTEN_DNSPORT_H */ 197