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 * socket properties (just like NSD nsd_socket structure definition) 107 */ 108 struct unbound_socket { 109 /** socket-address structure */ 110 struct addrinfo * addr; 111 /** socket descriptor returned by socket() syscall */ 112 int s; 113 /** address family (AF_INET/IF_INET6) */ 114 int fam; 115 }; 116 117 /** 118 * Single linked list to store shared ports that have been 119 * opened for use by all threads. 120 */ 121 struct listen_port { 122 /** next in list */ 123 struct listen_port* next; 124 /** file descriptor, open and ready for use */ 125 int fd; 126 /** type of file descriptor, udp or tcp */ 127 enum listen_type ftype; 128 /** fill in unbpound_socket structure for every opened socket at Unbound startup */ 129 struct unbound_socket* socket; 130 }; 131 132 /** 133 * Create shared listening ports 134 * Getaddrinfo, create socket, bind and listen to zero or more 135 * interfaces for IP4 and/or IP6, for UDP and/or TCP. 136 * On the given port number. It creates the sockets. 137 * @param cfg: settings on what ports to open. 138 * @param ifs: interfaces to open, array of IP addresses, "ip[@port]". 139 * @param num_ifs: length of ifs. 140 * @param reuseport: set to true if you want reuseport, or NULL to not have it, 141 * set to false on exit if reuseport failed to apply (because of no 142 * kernel support). 143 * @return: linked list of ports or NULL on error. 144 */ 145 struct listen_port* listening_ports_open(struct config_file* cfg, 146 char** ifs, int num_ifs, int* reuseport); 147 148 /** 149 * Close and delete the (list of) listening ports. 150 */ 151 void listening_ports_free(struct listen_port* list); 152 153 struct config_strlist; 154 /** 155 * Resolve interface names in config and store result IP addresses 156 * @param ifs: array of interfaces. The list of interface names, if not NULL. 157 * @param num_ifs: length of ifs array. 158 * @param list: if not NULL, this is used as the list of interface names. 159 * @param resif: string array (malloced array of malloced strings) with 160 * result. NULL if cfg has none. 161 * @param num_resif: length of resif. Zero if cfg has zero num_ifs. 162 * @return 0 on failure. 163 */ 164 int resolve_interface_names(char** ifs, int num_ifs, 165 struct config_strlist* list, char*** resif, int* num_resif); 166 167 /** 168 * Create commpoints with for this thread for the shared ports. 169 * @param base: the comm_base that provides event functionality. 170 * for default all ifs. 171 * @param ports: the list of shared ports. 172 * @param bufsize: size of datagram buffer. 173 * @param tcp_accept_count: max number of simultaneous TCP connections 174 * from clients. 175 * @param tcp_idle_timeout: idle timeout for TCP connections in msec. 176 * @param harden_large_queries: whether query size should be limited. 177 * @param http_max_streams: maximum number of HTTP/2 streams per connection. 178 * @param http_endpoint: HTTP endpoint to service queries on 179 * @param http_notls: no TLS for http downstream 180 * @param tcp_conn_limit: TCP connection limit info. 181 * @param sslctx: nonNULL if ssl context. 182 * @param dtenv: nonNULL if dnstap enabled. 183 * @param cb: callback function when a request arrives. It is passed 184 * the packet and user argument. Return true to send a reply. 185 * @param cb_arg: user data argument for callback function. 186 * @return: the malloced listening structure, ready for use. NULL on error. 187 */ 188 struct listen_dnsport* 189 listen_create(struct comm_base* base, struct listen_port* ports, 190 size_t bufsize, int tcp_accept_count, int tcp_idle_timeout, 191 int harden_large_queries, uint32_t http_max_streams, 192 char* http_endpoint, int http_notls, struct tcl_list* tcp_conn_limit, 193 void* sslctx, struct dt_env* dtenv, comm_point_callback_type* cb, 194 void *cb_arg); 195 196 /** 197 * delete the listening structure 198 * @param listen: listening structure. 199 */ 200 void listen_delete(struct listen_dnsport* listen); 201 202 /** 203 * delete listen_list of commpoints. Calls commpointdelete() on items. 204 * This may close the fds or not depending on flags. 205 * @param list: to delete. 206 */ 207 void listen_list_delete(struct listen_list* list); 208 209 /** 210 * get memory size used by the listening structs 211 * @param listen: listening structure. 212 * @return: size in bytes. 213 */ 214 size_t listen_get_mem(struct listen_dnsport* listen); 215 216 /** 217 * stop accept handlers for TCP (until enabled again) 218 * @param listen: listening structure. 219 */ 220 void listen_stop_accept(struct listen_dnsport* listen); 221 222 /** 223 * start accept handlers for TCP (was stopped before) 224 * @param listen: listening structure. 225 */ 226 void listen_start_accept(struct listen_dnsport* listen); 227 228 /** 229 * Create and bind nonblocking UDP socket 230 * @param family: for socket call. 231 * @param socktype: for socket call. 232 * @param addr: for bind call. 233 * @param addrlen: for bind call. 234 * @param v6only: if enabled, IP6 sockets get IP6ONLY option set. 235 * if enabled with value 2 IP6ONLY option is disabled. 236 * @param inuse: on error, this is set true if the port was in use. 237 * @param noproto: on error, this is set true if cause is that the 238 IPv6 proto (family) is not available. 239 * @param rcv: set size on rcvbuf with socket option, if 0 it is not set. 240 * @param snd: set size on sndbuf with socket option, if 0 it is not set. 241 * @param listen: if true, this is a listening UDP port, eg port 53, and 242 * set SO_REUSEADDR on it. 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 freebind: set IP_FREEBIND socket option. 247 * @param use_systemd: if true, fetch sockets from systemd. 248 * @param dscp: DSCP to use. 249 * @return: the socket. -1 on error. 250 */ 251 int create_udp_sock(int family, int socktype, struct sockaddr* addr, 252 socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv, 253 int snd, int listen, int* reuseport, int transparent, int freebind, int use_systemd, int dscp); 254 255 /** 256 * Create and bind TCP listening socket 257 * @param addr: address info ready to make socket. 258 * @param v6only: enable ip6 only flag on ip6 sockets. 259 * @param noproto: if error caused by lack of protocol support. 260 * @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on 261 * listening UDP port. Set to false on return if it failed to do so. 262 * @param transparent: set IP_TRANSPARENT socket option. 263 * @param mss: maximum segment size of the socket. if zero, leaves the default. 264 * @param nodelay: if true set TCP_NODELAY and TCP_QUICKACK socket options. 265 * @param freebind: set IP_FREEBIND socket option. 266 * @param use_systemd: if true, fetch sockets from systemd. 267 * @param dscp: DSCP to use. 268 * @return: the socket. -1 on error. 269 */ 270 int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto, 271 int* reuseport, int transparent, int mss, int nodelay, int freebind, 272 int use_systemd, int dscp); 273 274 /** 275 * Create and bind local listening socket 276 * @param path: path to the socket. 277 * @param noproto: on error, this is set true if cause is that local sockets 278 * are not supported. 279 * @param use_systemd: if true, fetch sockets from systemd. 280 * @return: the socket. -1 on error. 281 */ 282 int create_local_accept_sock(const char* path, int* noproto, int use_systemd); 283 284 /** 285 * TCP request info. List of requests outstanding on the channel, that 286 * are asked for but not yet answered back. 287 */ 288 struct tcp_req_info { 289 /** the TCP comm point for this. Its buffer is used for read/write */ 290 struct comm_point* cp; 291 /** the buffer to use to spool reply from mesh into, 292 * it can then be copied to the result list and written. 293 * it is a pointer to the shared udp buffer. */ 294 struct sldns_buffer* spool_buffer; 295 /** are we in worker_handle function call (for recursion callback)*/ 296 int in_worker_handle; 297 /** is the comm point dropped (by worker handle). 298 * That means we have to disconnect the channel. */ 299 int is_drop; 300 /** is the comm point set to send_reply (by mesh new client in worker 301 * handle), if so answer is available in c.buffer */ 302 int is_reply; 303 /** read channel has closed, just write pending results */ 304 int read_is_closed; 305 /** read again */ 306 int read_again; 307 /** number of outstanding requests */ 308 int num_open_req; 309 /** list of outstanding requests */ 310 struct tcp_req_open_item* open_req_list; 311 /** number of pending writeable results */ 312 int num_done_req; 313 /** list of pending writable result packets, malloced one at a time */ 314 struct tcp_req_done_item* done_req_list; 315 }; 316 317 /** 318 * List of open items in TCP channel 319 */ 320 struct tcp_req_open_item { 321 /** next in list */ 322 struct tcp_req_open_item* next; 323 /** the mesh area of the mesh_state */ 324 struct mesh_area* mesh; 325 /** the mesh state */ 326 struct mesh_state* mesh_state; 327 }; 328 329 /** 330 * List of done items in TCP channel 331 */ 332 struct tcp_req_done_item { 333 /** next in list */ 334 struct tcp_req_done_item* next; 335 /** the buffer with packet contents */ 336 uint8_t* buf; 337 /** length of the buffer */ 338 size_t len; 339 }; 340 341 /** 342 * Create tcp request info structure that keeps track of open 343 * requests on the TCP channel that are resolved at the same time, 344 * and the pending results that have to get written back to that client. 345 * @param spoolbuf: shared buffer 346 * @return new structure or NULL on alloc failure. 347 */ 348 struct tcp_req_info* tcp_req_info_create(struct sldns_buffer* spoolbuf); 349 350 /** 351 * Delete tcp request structure. Called by owning commpoint. 352 * Removes mesh entry references and stored results from the lists. 353 * @param req: the tcp request info 354 */ 355 void tcp_req_info_delete(struct tcp_req_info* req); 356 357 /** 358 * Clear tcp request structure. Removes list entries, sets it up ready 359 * for the next connection. 360 * @param req: tcp request info structure. 361 */ 362 void tcp_req_info_clear(struct tcp_req_info* req); 363 364 /** 365 * Remove mesh state entry from list in tcp_req_info. 366 * caller has to manage the mesh state reply entry in the mesh state. 367 * @param req: the tcp req info that has the entry removed from the list. 368 * @param m: the state removed from the list. 369 */ 370 void tcp_req_info_remove_mesh_state(struct tcp_req_info* req, 371 struct mesh_state* m); 372 373 /** 374 * Handle write done of the last result packet 375 * @param req: the tcp req info. 376 */ 377 void tcp_req_info_handle_writedone(struct tcp_req_info* req); 378 379 /** 380 * Handle read done of a new request from the client 381 * @param req: the tcp req info. 382 */ 383 void tcp_req_info_handle_readdone(struct tcp_req_info* req); 384 385 /** 386 * Add mesh state to the tcp req list of open requests. 387 * So the comm_reply can be removed off the mesh reply list when 388 * the tcp channel has to be closed (for other reasons then that that 389 * request was done, eg. channel closed by client or some format error). 390 * @param req: tcp req info structure. It keeps track of the simultaneous 391 * requests and results on a tcp (or TLS) channel. 392 * @param mesh: mesh area for the state. 393 * @param m: mesh state to add. 394 * @return 0 on failure (malloc failure). 395 */ 396 int tcp_req_info_add_meshstate(struct tcp_req_info* req, 397 struct mesh_area* mesh, struct mesh_state* m); 398 399 /** 400 * Send reply on tcp simultaneous answer channel. May queue it up. 401 * @param req: request info structure. 402 */ 403 void tcp_req_info_send_reply(struct tcp_req_info* req); 404 405 /** the read channel has closed 406 * @param req: request. remaining queries are looked up and answered. 407 * @return zero if nothing to do, just close the tcp. 408 */ 409 int tcp_req_info_handle_read_close(struct tcp_req_info* req); 410 411 /** get the size of currently used tcp stream wait buffers (in bytes) */ 412 size_t tcp_req_info_get_stream_buffer_size(void); 413 414 /** get the size of currently used HTTP2 query buffers (in bytes) */ 415 size_t http2_get_query_buffer_size(void); 416 /** get the size of currently used HTTP2 response buffers (in bytes) */ 417 size_t http2_get_response_buffer_size(void); 418 419 #ifdef HAVE_NGHTTP2 420 /** 421 * Create nghttp2 callbacks to handle HTTP2 requests. 422 * @return malloc'ed struct, NULL on failure 423 */ 424 nghttp2_session_callbacks* http2_req_callbacks_create(void); 425 426 /** Free http2 stream buffers and decrease buffer counters */ 427 void http2_req_stream_clear(struct http2_stream* h2_stream); 428 429 /** 430 * DNS response ready to be submitted to nghttp2, to be prepared for sending 431 * out. Response is stored in c->buffer. Copy to rbuffer because the c->buffer 432 * might be used before this will be send out. 433 * @param h2_session: http2 session, containing c->buffer which contains answer 434 * @param h2_stream: http2 stream, containing buffer to store answer in 435 * @return 0 on error, 1 otherwise 436 */ 437 int http2_submit_dns_response(struct http2_session* h2_session); 438 #else 439 int http2_submit_dns_response(void* v); 440 #endif /* HAVE_NGHTTP2 */ 441 442 char* set_ip_dscp(int socket, int addrfamily, int ds); 443 444 /** for debug and profiling purposes only 445 * @param ub_sock: the structure containing created socket info we want to print or log for 446 */ 447 void verbose_print_unbound_socket(struct unbound_socket* ub_sock); 448 449 #endif /* LISTEN_DNSPORT_H */ 450