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.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
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.
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.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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"
46 #ifdef HAVE_NGHTTP2_NGHTTP2_H
47 #include <nghttp2/nghttp2.h>
56 * Listening for queries structure.
57 * Contains list of query-listen sockets.
59 struct listen_dnsport {
60 /** Base for select calls */
61 struct comm_base* base;
63 /** buffer shared by UDP connections, since there is only one
64 datagram at any time. */
65 struct sldns_buffer* udp_buff;
67 struct sldns_buffer* dnscrypt_udp_buff;
69 /** list of comm points used to get incoming events */
70 struct listen_list* cps;
74 * Single linked list to store event points.
78 struct listen_list* next;
80 struct comm_point* com;
91 /** udp ipv6 (v4mapped) for use with ancillary data */
93 /** ssl over tcp type */
95 /** udp type + dnscrypt*/
96 listen_type_udp_dnscrypt,
97 /** tcp type + dnscrypt */
98 listen_type_tcp_dnscrypt,
99 /** udp ipv6 (v4mapped) for use with ancillary data + dnscrypt*/
100 listen_type_udpancil_dnscrypt,
101 /** HTTP(2) over TLS over TCP */
106 * Single linked list to store shared ports that have been
107 * opened for use by all threads.
111 struct listen_port* next;
112 /** file descriptor, open and ready for use */
114 /** type of file descriptor, udp or tcp */
115 enum listen_type ftype;
119 * Create shared listening ports
120 * Getaddrinfo, create socket, bind and listen to zero or more
121 * interfaces for IP4 and/or IP6, for UDP and/or TCP.
122 * On the given port number. It creates the sockets.
123 * @param cfg: settings on what ports to open.
124 * @param ifs: interfaces to open, array of IP addresses, "ip[@port]".
125 * @param num_ifs: length of ifs.
126 * @param reuseport: set to true if you want reuseport, or NULL to not have it,
127 * set to false on exit if reuseport failed to apply (because of no
129 * @return: linked list of ports or NULL on error.
131 struct listen_port* listening_ports_open(struct config_file* cfg,
132 char** ifs, int num_ifs, int* reuseport);
135 * Close and delete the (list of) listening ports.
137 void listening_ports_free(struct listen_port* list);
140 * Resolve interface names in config and store result IP addresses
142 * @param resif: string array (malloced array of malloced strings) with
143 * result. NULL if cfg has none.
144 * @param num_resif: length of resif. Zero if cfg has zero num_ifs.
145 * @return 0 on failure.
147 int resolve_interface_names(struct config_file* cfg, char*** resif,
151 * Create commpoints with for this thread for the shared ports.
152 * @param base: the comm_base that provides event functionality.
153 * for default all ifs.
154 * @param ports: the list of shared ports.
155 * @param bufsize: size of datagram buffer.
156 * @param tcp_accept_count: max number of simultaneous TCP connections
158 * @param tcp_idle_timeout: idle timeout for TCP connections in msec.
159 * @param harden_large_queries: whether query size should be limited.
160 * @param http_max_streams: maximum number of HTTP/2 streams per connection.
161 * @param http_endpoint: HTTP endpoint to service queries on
162 * @param http_notls: no TLS for http downstream
163 * @param tcp_conn_limit: TCP connection limit info.
164 * @param sslctx: nonNULL if ssl context.
165 * @param dtenv: nonNULL if dnstap enabled.
166 * @param cb: callback function when a request arrives. It is passed
167 * the packet and user argument. Return true to send a reply.
168 * @param cb_arg: user data argument for callback function.
169 * @return: the malloced listening structure, ready for use. NULL on error.
171 struct listen_dnsport*
172 listen_create(struct comm_base* base, struct listen_port* ports,
173 size_t bufsize, int tcp_accept_count, int tcp_idle_timeout,
174 int harden_large_queries, uint32_t http_max_streams,
175 char* http_endpoint, int http_notls, struct tcl_list* tcp_conn_limit,
176 void* sslctx, struct dt_env* dtenv, comm_point_callback_type* cb,
180 * delete the listening structure
181 * @param listen: listening structure.
183 void listen_delete(struct listen_dnsport* listen);
186 * delete listen_list of commpoints. Calls commpointdelete() on items.
187 * This may close the fds or not depending on flags.
188 * @param list: to delete.
190 void listen_list_delete(struct listen_list* list);
193 * get memory size used by the listening structs
194 * @param listen: listening structure.
195 * @return: size in bytes.
197 size_t listen_get_mem(struct listen_dnsport* listen);
200 * stop accept handlers for TCP (until enabled again)
201 * @param listen: listening structure.
203 void listen_stop_accept(struct listen_dnsport* listen);
206 * start accept handlers for TCP (was stopped before)
207 * @param listen: listening structure.
209 void listen_start_accept(struct listen_dnsport* listen);
212 * Create and bind nonblocking UDP socket
213 * @param family: for socket call.
214 * @param socktype: for socket call.
215 * @param addr: for bind call.
216 * @param addrlen: for bind call.
217 * @param v6only: if enabled, IP6 sockets get IP6ONLY option set.
218 * if enabled with value 2 IP6ONLY option is disabled.
219 * @param inuse: on error, this is set true if the port was in use.
220 * @param noproto: on error, this is set true if cause is that the
221 IPv6 proto (family) is not available.
222 * @param rcv: set size on rcvbuf with socket option, if 0 it is not set.
223 * @param snd: set size on sndbuf with socket option, if 0 it is not set.
224 * @param listen: if true, this is a listening UDP port, eg port 53, and
225 * set SO_REUSEADDR on it.
226 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
227 * listening UDP port. Set to false on return if it failed to do so.
228 * @param transparent: set IP_TRANSPARENT socket option.
229 * @param freebind: set IP_FREEBIND socket option.
230 * @param use_systemd: if true, fetch sockets from systemd.
231 * @param dscp: DSCP to use.
232 * @return: the socket. -1 on error.
234 int create_udp_sock(int family, int socktype, struct sockaddr* addr,
235 socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv,
236 int snd, int listen, int* reuseport, int transparent, int freebind, int use_systemd, int dscp);
239 * Create and bind TCP listening socket
240 * @param addr: address info ready to make socket.
241 * @param v6only: enable ip6 only flag on ip6 sockets.
242 * @param noproto: if error caused by lack of protocol support.
243 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
244 * listening UDP port. Set to false on return if it failed to do so.
245 * @param transparent: set IP_TRANSPARENT socket option.
246 * @param mss: maximum segment size of the socket. if zero, leaves the default.
247 * @param nodelay: if true set TCP_NODELAY and TCP_QUICKACK socket options.
248 * @param freebind: set IP_FREEBIND socket option.
249 * @param use_systemd: if true, fetch sockets from systemd.
250 * @param dscp: DSCP to use.
251 * @return: the socket. -1 on error.
253 int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto,
254 int* reuseport, int transparent, int mss, int nodelay, int freebind,
255 int use_systemd, int dscp);
258 * Create and bind local listening socket
259 * @param path: path to the socket.
260 * @param noproto: on error, this is set true if cause is that local sockets
262 * @param use_systemd: if true, fetch sockets from systemd.
263 * @return: the socket. -1 on error.
265 int create_local_accept_sock(const char* path, int* noproto, int use_systemd);
268 * TCP request info. List of requests outstanding on the channel, that
269 * are asked for but not yet answered back.
271 struct tcp_req_info {
272 /** the TCP comm point for this. Its buffer is used for read/write */
273 struct comm_point* cp;
274 /** the buffer to use to spool reply from mesh into,
275 * it can then be copied to the result list and written.
276 * it is a pointer to the shared udp buffer. */
277 struct sldns_buffer* spool_buffer;
278 /** are we in worker_handle function call (for recursion callback)*/
279 int in_worker_handle;
280 /** is the comm point dropped (by worker handle).
281 * That means we have to disconnect the channel. */
283 /** is the comm point set to send_reply (by mesh new client in worker
284 * handle), if so answer is available in c.buffer */
286 /** read channel has closed, just write pending results */
290 /** number of outstanding requests */
292 /** list of outstanding requests */
293 struct tcp_req_open_item* open_req_list;
294 /** number of pending writeable results */
296 /** list of pending writable result packets, malloced one at a time */
297 struct tcp_req_done_item* done_req_list;
301 * List of open items in TCP channel
303 struct tcp_req_open_item {
305 struct tcp_req_open_item* next;
306 /** the mesh area of the mesh_state */
307 struct mesh_area* mesh;
308 /** the mesh state */
309 struct mesh_state* mesh_state;
313 * List of done items in TCP channel
315 struct tcp_req_done_item {
317 struct tcp_req_done_item* next;
318 /** the buffer with packet contents */
320 /** length of the buffer */
325 * Create tcp request info structure that keeps track of open
326 * requests on the TCP channel that are resolved at the same time,
327 * and the pending results that have to get written back to that client.
328 * @param spoolbuf: shared buffer
329 * @return new structure or NULL on alloc failure.
331 struct tcp_req_info* tcp_req_info_create(struct sldns_buffer* spoolbuf);
334 * Delete tcp request structure. Called by owning commpoint.
335 * Removes mesh entry references and stored results from the lists.
336 * @param req: the tcp request info
338 void tcp_req_info_delete(struct tcp_req_info* req);
341 * Clear tcp request structure. Removes list entries, sets it up ready
342 * for the next connection.
343 * @param req: tcp request info structure.
345 void tcp_req_info_clear(struct tcp_req_info* req);
348 * Remove mesh state entry from list in tcp_req_info.
349 * caller has to manage the mesh state reply entry in the mesh state.
350 * @param req: the tcp req info that has the entry removed from the list.
351 * @param m: the state removed from the list.
353 void tcp_req_info_remove_mesh_state(struct tcp_req_info* req,
354 struct mesh_state* m);
357 * Handle write done of the last result packet
358 * @param req: the tcp req info.
360 void tcp_req_info_handle_writedone(struct tcp_req_info* req);
363 * Handle read done of a new request from the client
364 * @param req: the tcp req info.
366 void tcp_req_info_handle_readdone(struct tcp_req_info* req);
369 * Add mesh state to the tcp req list of open requests.
370 * So the comm_reply can be removed off the mesh reply list when
371 * the tcp channel has to be closed (for other reasons then that that
372 * request was done, eg. channel closed by client or some format error).
373 * @param req: tcp req info structure. It keeps track of the simultaneous
374 * requests and results on a tcp (or TLS) channel.
375 * @param mesh: mesh area for the state.
376 * @param m: mesh state to add.
377 * @return 0 on failure (malloc failure).
379 int tcp_req_info_add_meshstate(struct tcp_req_info* req,
380 struct mesh_area* mesh, struct mesh_state* m);
383 * Send reply on tcp simultaneous answer channel. May queue it up.
384 * @param req: request info structure.
386 void tcp_req_info_send_reply(struct tcp_req_info* req);
388 /** the read channel has closed
389 * @param req: request. remaining queries are looked up and answered.
390 * @return zero if nothing to do, just close the tcp.
392 int tcp_req_info_handle_read_close(struct tcp_req_info* req);
394 /** get the size of currently used tcp stream wait buffers (in bytes) */
395 size_t tcp_req_info_get_stream_buffer_size(void);
397 /** get the size of currently used HTTP2 query buffers (in bytes) */
398 size_t http2_get_query_buffer_size(void);
399 /** get the size of currently used HTTP2 response buffers (in bytes) */
400 size_t http2_get_response_buffer_size(void);
404 * Create nghttp2 callbacks to handle HTTP2 requests.
405 * @return malloc'ed struct, NULL on failure
407 nghttp2_session_callbacks* http2_req_callbacks_create();
409 /** Free http2 stream buffers and decrease buffer counters */
410 void http2_req_stream_clear(struct http2_stream* h2_stream);
413 * DNS response ready to be submitted to nghttp2, to be prepared for sending
414 * out. Response is stored in c->buffer. Copy to rbuffer because the c->buffer
415 * might be used before this will be send out.
416 * @param h2_session: http2 session, containing c->buffer which contains answer
417 * @param h2_stream: http2 stream, containing buffer to store answer in
418 * @return 0 on error, 1 otherwise
420 int http2_submit_dns_response(struct http2_session* h2_session);
422 int http2_submit_dns_response(void* v);
423 #endif /* HAVE_NGHTTP2 */
425 char* set_ip_dscp(int socket, int addrfamily, int ds);
427 #endif /* LISTEN_DNSPORT_H */