2 * services/listen_dnsport.h - listen on port 53 for incoming DNS queries.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
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39 * This file has functions to get queries from clients.
42 #ifndef LISTEN_DNSPORT_H
43 #define LISTEN_DNSPORT_H
45 #include "util/netevent.h"
52 * Listening for queries structure.
53 * Contains list of query-listen sockets.
55 struct listen_dnsport {
56 /** Base for select calls */
57 struct comm_base* base;
59 /** buffer shared by UDP connections, since there is only one
60 datagram at any time. */
61 struct sldns_buffer* udp_buff;
63 struct sldns_buffer* dnscrypt_udp_buff;
65 /** list of comm points used to get incoming events */
66 struct listen_list* cps;
70 * Single linked list to store event points.
74 struct listen_list* next;
76 struct comm_point* com;
87 /** udp ipv6 (v4mapped) for use with ancillary data */
89 /** ssl over tcp type */
91 /** udp type + dnscrypt*/
92 listen_type_udp_dnscrypt,
93 /** tcp type + dnscrypt */
94 listen_type_tcp_dnscrypt,
95 /** udp ipv6 (v4mapped) for use with ancillary data + dnscrypt*/
96 listen_type_udpancil_dnscrypt
101 * Single linked list to store shared ports that have been
102 * opened for use by all threads.
106 struct listen_port* next;
107 /** file descriptor, open and ready for use */
109 /** type of file descriptor, udp or tcp */
110 enum listen_type ftype;
114 * Create shared listening ports
115 * Getaddrinfo, create socket, bind and listen to zero or more
116 * interfaces for IP4 and/or IP6, for UDP and/or TCP.
117 * On the given port number. It creates the sockets.
118 * @param cfg: settings on what ports to open.
119 * @param reuseport: set to true if you want reuseport, or NULL to not have it,
120 * set to false on exit if reuseport failed to apply (because of no
122 * @return: linked list of ports or NULL on error.
124 struct listen_port* listening_ports_open(struct config_file* cfg,
128 * Close and delete the (list of) listening ports.
130 void listening_ports_free(struct listen_port* list);
133 * Create commpoints with for this thread for the shared ports.
134 * @param base: the comm_base that provides event functionality.
135 * for default all ifs.
136 * @param ports: the list of shared ports.
137 * @param bufsize: size of datagram buffer.
138 * @param tcp_accept_count: max number of simultaneous TCP connections
140 * @param sslctx: nonNULL if ssl context.
141 * @param dtenv: nonNULL if dnstap enabled.
142 * @param cb: callback function when a request arrives. It is passed
143 * the packet and user argument. Return true to send a reply.
144 * @param cb_arg: user data argument for callback function.
145 * @return: the malloced listening structure, ready for use. NULL on error.
147 struct listen_dnsport* listen_create(struct comm_base* base,
148 struct listen_port* ports, size_t bufsize, int tcp_accept_count,
149 void* sslctx, struct dt_env *dtenv, comm_point_callback_type* cb,
153 * delete the listening structure
154 * @param listen: listening structure.
156 void listen_delete(struct listen_dnsport* listen);
159 * delete listen_list of commpoints. Calls commpointdelete() on items.
160 * This may close the fds or not depending on flags.
161 * @param list: to delete.
163 void listen_list_delete(struct listen_list* list);
166 * get memory size used by the listening structs
167 * @param listen: listening structure.
168 * @return: size in bytes.
170 size_t listen_get_mem(struct listen_dnsport* listen);
173 * stop accept handlers for TCP (until enabled again)
174 * @param listen: listening structure.
176 void listen_stop_accept(struct listen_dnsport* listen);
179 * start accept handlers for TCP (was stopped before)
180 * @param listen: listening structure.
182 void listen_start_accept(struct listen_dnsport* listen);
185 * Create and bind nonblocking UDP socket
186 * @param family: for socket call.
187 * @param socktype: for socket call.
188 * @param addr: for bind call.
189 * @param addrlen: for bind call.
190 * @param v6only: if enabled, IP6 sockets get IP6ONLY option set.
191 * if enabled with value 2 IP6ONLY option is disabled.
192 * @param inuse: on error, this is set true if the port was in use.
193 * @param noproto: on error, this is set true if cause is that the
194 IPv6 proto (family) is not available.
195 * @param rcv: set size on rcvbuf with socket option, if 0 it is not set.
196 * @param snd: set size on sndbuf with socket option, if 0 it is not set.
197 * @param listen: if true, this is a listening UDP port, eg port 53, and
198 * set SO_REUSEADDR on it.
199 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
200 * listening UDP port. Set to false on return if it failed to do so.
201 * @param transparent: set IP_TRANSPARENT socket option.
202 * @param freebind: set IP_FREEBIND socket option.
203 * @param use_systemd: if true, fetch sockets from systemd.
204 * @return: the socket. -1 on error.
206 int create_udp_sock(int family, int socktype, struct sockaddr* addr,
207 socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv,
208 int snd, int listen, int* reuseport, int transparent, int freebind, int use_systemd);
211 * Create and bind TCP listening socket
212 * @param addr: address info ready to make socket.
213 * @param v6only: enable ip6 only flag on ip6 sockets.
214 * @param noproto: if error caused by lack of protocol support.
215 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
216 * listening UDP port. Set to false on return if it failed to do so.
217 * @param transparent: set IP_TRANSPARENT socket option.
218 * @param mss: maximum segment size of the socket. if zero, leaves the default.
219 * @param freebind: set IP_FREEBIND socket option.
220 * @param use_systemd: if true, fetch sockets from systemd.
221 * @return: the socket. -1 on error.
223 int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto,
224 int* reuseport, int transparent, int mss, int freebind, int use_systemd);
227 * Create and bind local listening socket
228 * @param path: path to the socket.
229 * @param noproto: on error, this is set true if cause is that local sockets
231 * @param use_systemd: if true, fetch sockets from systemd.
232 * @return: the socket. -1 on error.
234 int create_local_accept_sock(const char* path, int* noproto, int use_systemd);
236 #endif /* LISTEN_DNSPORT_H */