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 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 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE 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 #ifdef HAVE_NGHTTP2_NGHTTP2_H 47 #include <nghttp2/nghttp2.h> 48 #endif 49 struct listen_list; 50 struct config_file; 51 struct addrinfo; 52 struct sldns_buffer; 53 struct tcl_list; 54 55 /** 56 * Listening for queries structure. 57 * Contains list of query-listen sockets. 58 */ 59 struct listen_dnsport { 60 /** Base for select calls */ 61 struct comm_base* base; 62 63 /** buffer shared by UDP connections, since there is only one 64 datagram at any time. */ 65 struct sldns_buffer* udp_buff; 66 #ifdef USE_DNSCRYPT 67 struct sldns_buffer* dnscrypt_udp_buff; 68 #endif 69 /** list of comm points used to get incoming events */ 70 struct listen_list* cps; 71 }; 72 73 /** 74 * Single linked list to store event points. 75 */ 76 struct listen_list { 77 /** next in list */ 78 struct listen_list* next; 79 /** event info */ 80 struct comm_point* com; 81 }; 82 83 /** 84 * type of ports 85 */ 86 enum listen_type { 87 /** udp type */ 88 listen_type_udp, 89 /** tcp type */ 90 listen_type_tcp, 91 /** udp ipv6 (v4mapped) for use with ancillary data */ 92 listen_type_udpancil, 93 /** ssl over tcp type */ 94 listen_type_ssl, 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 */ 102 listen_type_http 103 }; 104 105 /** 106 * Single linked list to store shared ports that have been 107 * opened for use by all threads. 108 */ 109 struct listen_port { 110 /** next in list */ 111 struct listen_port* next; 112 /** file descriptor, open and ready for use */ 113 int fd; 114 /** type of file descriptor, udp or tcp */ 115 enum listen_type ftype; 116 }; 117 118 /** 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 128 * kernel support). 129 * @return: linked list of ports or NULL on error. 130 */ 131 struct listen_port* listening_ports_open(struct config_file* cfg, 132 char** ifs, int num_ifs, int* reuseport); 133 134 /** 135 * Close and delete the (list of) listening ports. 136 */ 137 void listening_ports_free(struct listen_port* list); 138 139 /** 140 * Resolve interface names in config and store result IP addresses 141 * @param cfg: config 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. 146 */ 147 int resolve_interface_names(struct config_file* cfg, char*** resif, 148 int* num_resif); 149 150 /** 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 157 * from clients. 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. 170 */ 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, 177 void *cb_arg); 178 179 /** 180 * delete the listening structure 181 * @param listen: listening structure. 182 */ 183 void listen_delete(struct listen_dnsport* listen); 184 185 /** 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. 189 */ 190 void listen_list_delete(struct listen_list* list); 191 192 /** 193 * get memory size used by the listening structs 194 * @param listen: listening structure. 195 * @return: size in bytes. 196 */ 197 size_t listen_get_mem(struct listen_dnsport* listen); 198 199 /** 200 * stop accept handlers for TCP (until enabled again) 201 * @param listen: listening structure. 202 */ 203 void listen_stop_accept(struct listen_dnsport* listen); 204 205 /** 206 * start accept handlers for TCP (was stopped before) 207 * @param listen: listening structure. 208 */ 209 void listen_start_accept(struct listen_dnsport* listen); 210 211 /** 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. 233 */ 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); 237 238 /** 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. 252 */ 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); 256 257 /** 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 261 * are not supported. 262 * @param use_systemd: if true, fetch sockets from systemd. 263 * @return: the socket. -1 on error. 264 */ 265 int create_local_accept_sock(const char* path, int* noproto, int use_systemd); 266 267 /** 268 * TCP request info. List of requests outstanding on the channel, that 269 * are asked for but not yet answered back. 270 */ 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. */ 282 int is_drop; 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 */ 285 int is_reply; 286 /** read channel has closed, just write pending results */ 287 int read_is_closed; 288 /** read again */ 289 int read_again; 290 /** number of outstanding requests */ 291 int num_open_req; 292 /** list of outstanding requests */ 293 struct tcp_req_open_item* open_req_list; 294 /** number of pending writeable results */ 295 int num_done_req; 296 /** list of pending writable result packets, malloced one at a time */ 297 struct tcp_req_done_item* done_req_list; 298 }; 299 300 /** 301 * List of open items in TCP channel 302 */ 303 struct tcp_req_open_item { 304 /** next in list */ 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; 310 }; 311 312 /** 313 * List of done items in TCP channel 314 */ 315 struct tcp_req_done_item { 316 /** next in list */ 317 struct tcp_req_done_item* next; 318 /** the buffer with packet contents */ 319 uint8_t* buf; 320 /** length of the buffer */ 321 size_t len; 322 }; 323 324 /** 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. 330 */ 331 struct tcp_req_info* tcp_req_info_create(struct sldns_buffer* spoolbuf); 332 333 /** 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 337 */ 338 void tcp_req_info_delete(struct tcp_req_info* req); 339 340 /** 341 * Clear tcp request structure. Removes list entries, sets it up ready 342 * for the next connection. 343 * @param req: tcp request info structure. 344 */ 345 void tcp_req_info_clear(struct tcp_req_info* req); 346 347 /** 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. 352 */ 353 void tcp_req_info_remove_mesh_state(struct tcp_req_info* req, 354 struct mesh_state* m); 355 356 /** 357 * Handle write done of the last result packet 358 * @param req: the tcp req info. 359 */ 360 void tcp_req_info_handle_writedone(struct tcp_req_info* req); 361 362 /** 363 * Handle read done of a new request from the client 364 * @param req: the tcp req info. 365 */ 366 void tcp_req_info_handle_readdone(struct tcp_req_info* req); 367 368 /** 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). 378 */ 379 int tcp_req_info_add_meshstate(struct tcp_req_info* req, 380 struct mesh_area* mesh, struct mesh_state* m); 381 382 /** 383 * Send reply on tcp simultaneous answer channel. May queue it up. 384 * @param req: request info structure. 385 */ 386 void tcp_req_info_send_reply(struct tcp_req_info* req); 387 388 /** 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. 391 */ 392 int tcp_req_info_handle_read_close(struct tcp_req_info* req); 393 394 /** get the size of currently used tcp stream wait buffers (in bytes) */ 395 size_t tcp_req_info_get_stream_buffer_size(void); 396 397 /** 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); 401 402 #ifdef HAVE_NGHTTP2 403 /** 404 * Create nghttp2 callbacks to handle HTTP2 requests. 405 * @return malloc'ed struct, NULL on failure 406 */ 407 nghttp2_session_callbacks* http2_req_callbacks_create(void); 408 409 /** Free http2 stream buffers and decrease buffer counters */ 410 void http2_req_stream_clear(struct http2_stream* h2_stream); 411 412 /** 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 419 */ 420 int http2_submit_dns_response(struct http2_session* h2_session); 421 #else 422 int http2_submit_dns_response(void* v); 423 #endif /* HAVE_NGHTTP2 */ 424 425 char* set_ip_dscp(int socket, int addrfamily, int ds); 426 427 #endif /* LISTEN_DNSPORT_H */ 428