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"
46struct listen_list;
47struct config_file;
48struct addrinfo;
49
50/**
51 * Listening for queries structure.
52 * Contains list of query-listen sockets.
53 */
54struct 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 */
69struct 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 */
79enum 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 */
94struct 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 */
111struct listen_port* listening_ports_open(struct config_file* cfg);
112
113/**
114 * Close and delete the (list of) listening ports.
115 */
116void 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 */
132struct 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 */
140void 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 */
147void 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 */
154size_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 */
160void listen_stop_accept(struct listen_dnsport* listen);
161
162/**
163 * start accept handlers for TCP (was stopped before)
164 * @param listen: listening structure.
165 */
166void 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 */
183int 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 */
194int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto);
195
196#endif /* LISTEN_DNSPORT_H */
197