2 * services/listen_dnsport.h - listen on port 53 for incoming DNS queries.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
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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"
53 * Listening for queries structure.
54 * Contains list of query-listen sockets.
56 struct listen_dnsport {
57 /** Base for select calls */
58 struct comm_base* base;
60 /** buffer shared by UDP connections, since there is only one
61 datagram at any time. */
62 struct sldns_buffer* udp_buff;
64 struct sldns_buffer* dnscrypt_udp_buff;
66 /** list of comm points used to get incoming events */
67 struct listen_list* cps;
71 * Single linked list to store event points.
75 struct listen_list* next;
77 struct comm_point* com;
88 /** udp ipv6 (v4mapped) for use with ancillary data */
90 /** ssl over tcp type */
92 /** udp type + dnscrypt*/
93 listen_type_udp_dnscrypt,
94 /** tcp type + dnscrypt */
95 listen_type_tcp_dnscrypt,
96 /** udp ipv6 (v4mapped) for use with ancillary data + dnscrypt*/
97 listen_type_udpancil_dnscrypt
102 * Single linked list to store shared ports that have been
103 * opened for use by all threads.
107 struct listen_port* next;
108 /** file descriptor, open and ready for use */
110 /** type of file descriptor, udp or tcp */
111 enum listen_type ftype;
115 * Create shared listening ports
116 * Getaddrinfo, create socket, bind and listen to zero or more
117 * interfaces for IP4 and/or IP6, for UDP and/or TCP.
118 * On the given port number. It creates the sockets.
119 * @param cfg: settings on what ports to open.
120 * @param reuseport: set to true if you want reuseport, or NULL to not have it,
121 * set to false on exit if reuseport failed to apply (because of no
123 * @return: linked list of ports or NULL on error.
125 struct listen_port* listening_ports_open(struct config_file* cfg,
129 * Close and delete the (list of) listening ports.
131 void listening_ports_free(struct listen_port* list);
134 * Create commpoints with for this thread for the shared ports.
135 * @param base: the comm_base that provides event functionality.
136 * for default all ifs.
137 * @param ports: the list of shared ports.
138 * @param bufsize: size of datagram buffer.
139 * @param tcp_accept_count: max number of simultaneous TCP connections
141 * @param tcp_idle_timeout: idle timeout for TCP connections in msec.
142 * @param tcp_conn_limit: TCP connection limit info.
143 * @param sslctx: nonNULL if ssl context.
144 * @param dtenv: nonNULL if dnstap enabled.
145 * @param cb: callback function when a request arrives. It is passed
146 * the packet and user argument. Return true to send a reply.
147 * @param cb_arg: user data argument for callback function.
148 * @return: the malloced listening structure, ready for use. NULL on error.
150 struct listen_dnsport* listen_create(struct comm_base* base,
151 struct listen_port* ports, size_t bufsize,
152 int tcp_accept_count, int tcp_idle_timeout,
153 struct tcl_list* tcp_conn_limit, void* sslctx,
154 struct dt_env *dtenv, comm_point_callback_type* cb, void* cb_arg);
157 * delete the listening structure
158 * @param listen: listening structure.
160 void listen_delete(struct listen_dnsport* listen);
163 * delete listen_list of commpoints. Calls commpointdelete() on items.
164 * This may close the fds or not depending on flags.
165 * @param list: to delete.
167 void listen_list_delete(struct listen_list* list);
170 * get memory size used by the listening structs
171 * @param listen: listening structure.
172 * @return: size in bytes.
174 size_t listen_get_mem(struct listen_dnsport* listen);
177 * stop accept handlers for TCP (until enabled again)
178 * @param listen: listening structure.
180 void listen_stop_accept(struct listen_dnsport* listen);
183 * start accept handlers for TCP (was stopped before)
184 * @param listen: listening structure.
186 void listen_start_accept(struct listen_dnsport* listen);
189 * Create and bind nonblocking UDP socket
190 * @param family: for socket call.
191 * @param socktype: for socket call.
192 * @param addr: for bind call.
193 * @param addrlen: for bind call.
194 * @param v6only: if enabled, IP6 sockets get IP6ONLY option set.
195 * if enabled with value 2 IP6ONLY option is disabled.
196 * @param inuse: on error, this is set true if the port was in use.
197 * @param noproto: on error, this is set true if cause is that the
198 IPv6 proto (family) is not available.
199 * @param rcv: set size on rcvbuf with socket option, if 0 it is not set.
200 * @param snd: set size on sndbuf with socket option, if 0 it is not set.
201 * @param listen: if true, this is a listening UDP port, eg port 53, and
202 * set SO_REUSEADDR on it.
203 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
204 * listening UDP port. Set to false on return if it failed to do so.
205 * @param transparent: set IP_TRANSPARENT socket option.
206 * @param freebind: set IP_FREEBIND socket option.
207 * @param use_systemd: if true, fetch sockets from systemd.
208 * @param dscp: DSCP to use.
209 * @return: the socket. -1 on error.
211 int create_udp_sock(int family, int socktype, struct sockaddr* addr,
212 socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv,
213 int snd, int listen, int* reuseport, int transparent, int freebind, int use_systemd, int dscp);
216 * Create and bind TCP listening socket
217 * @param addr: address info ready to make socket.
218 * @param v6only: enable ip6 only flag on ip6 sockets.
219 * @param noproto: if error caused by lack of protocol support.
220 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
221 * listening UDP port. Set to false on return if it failed to do so.
222 * @param transparent: set IP_TRANSPARENT socket option.
223 * @param mss: maximum segment size of the socket. if zero, leaves the default.
224 * @param freebind: set IP_FREEBIND socket option.
225 * @param use_systemd: if true, fetch sockets from systemd.
226 * @param dscp: DSCP to use.
227 * @return: the socket. -1 on error.
229 int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto,
230 int* reuseport, int transparent, int mss, int freebind, int use_systemd, int dscp);
233 * Create and bind local listening socket
234 * @param path: path to the socket.
235 * @param noproto: on error, this is set true if cause is that local sockets
237 * @param use_systemd: if true, fetch sockets from systemd.
238 * @return: the socket. -1 on error.
240 int create_local_accept_sock(const char* path, int* noproto, int use_systemd);
243 * TCP request info. List of requests outstanding on the channel, that
244 * are asked for but not yet answered back.
246 struct tcp_req_info {
247 /** the TCP comm point for this. Its buffer is used for read/write */
248 struct comm_point* cp;
249 /** the buffer to use to spool reply from mesh into,
250 * it can then be copied to the result list and written.
251 * it is a pointer to the shared udp buffer. */
252 struct sldns_buffer* spool_buffer;
253 /** are we in worker_handle function call (for recursion callback)*/
254 int in_worker_handle;
255 /** is the comm point dropped (by worker handle).
256 * That means we have to disconnect the channel. */
258 /** is the comm point set to send_reply (by mesh new client in worker
259 * handle), if so answer is available in c.buffer */
261 /** read channel has closed, just write pending results */
265 /** number of outstanding requests */
267 /** list of outstanding requests */
268 struct tcp_req_open_item* open_req_list;
269 /** number of pending writeable results */
271 /** list of pending writable result packets, malloced one at a time */
272 struct tcp_req_done_item* done_req_list;
276 * List of open items in TCP channel
278 struct tcp_req_open_item {
280 struct tcp_req_open_item* next;
281 /** the mesh area of the mesh_state */
282 struct mesh_area* mesh;
283 /** the mesh state */
284 struct mesh_state* mesh_state;
288 * List of done items in TCP channel
290 struct tcp_req_done_item {
292 struct tcp_req_done_item* next;
293 /** the buffer with packet contents */
295 /** length of the buffer */
300 * Create tcp request info structure that keeps track of open
301 * requests on the TCP channel that are resolved at the same time,
302 * and the pending results that have to get written back to that client.
303 * @param spoolbuf: shared buffer
304 * @return new structure or NULL on alloc failure.
306 struct tcp_req_info* tcp_req_info_create(struct sldns_buffer* spoolbuf);
309 * Delete tcp request structure. Called by owning commpoint.
310 * Removes mesh entry references and stored results from the lists.
311 * @param req: the tcp request info
313 void tcp_req_info_delete(struct tcp_req_info* req);
316 * Clear tcp request structure. Removes list entries, sets it up ready
317 * for the next connection.
318 * @param req: tcp request info structure.
320 void tcp_req_info_clear(struct tcp_req_info* req);
323 * Remove mesh state entry from list in tcp_req_info.
324 * caller has to manage the mesh state reply entry in the mesh state.
325 * @param req: the tcp req info that has the entry removed from the list.
326 * @param m: the state removed from the list.
328 void tcp_req_info_remove_mesh_state(struct tcp_req_info* req,
329 struct mesh_state* m);
332 * Handle write done of the last result packet
333 * @param req: the tcp req info.
335 void tcp_req_info_handle_writedone(struct tcp_req_info* req);
338 * Handle read done of a new request from the client
339 * @param req: the tcp req info.
341 void tcp_req_info_handle_readdone(struct tcp_req_info* req);
344 * Add mesh state to the tcp req list of open requests.
345 * So the comm_reply can be removed off the mesh reply list when
346 * the tcp channel has to be closed (for other reasons then that that
347 * request was done, eg. channel closed by client or some format error).
348 * @param req: tcp req info structure. It keeps track of the simultaneous
349 * requests and results on a tcp (or TLS) channel.
350 * @param mesh: mesh area for the state.
351 * @param m: mesh state to add.
352 * @return 0 on failure (malloc failure).
354 int tcp_req_info_add_meshstate(struct tcp_req_info* req,
355 struct mesh_area* mesh, struct mesh_state* m);
358 * Send reply on tcp simultaneous answer channel. May queue it up.
359 * @param req: request info structure.
361 void tcp_req_info_send_reply(struct tcp_req_info* req);
363 /** the read channel has closed
364 * @param req: request. remaining queries are looked up and answered.
365 * @return zero if nothing to do, just close the tcp.
367 int tcp_req_info_handle_read_close(struct tcp_req_info* req);
369 /** get the size of currently used tcp stream wait buffers (in bytes) */
370 size_t tcp_req_info_get_stream_buffer_size(void);
372 char* set_ip_dscp(int socket, int addrfamily, int ds);
373 char* sock_strerror(int errn);
375 #endif /* LISTEN_DNSPORT_H */