1 /* 2 * services/outside_network.h - listen to answers from the network 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 send queries to authoritative servers, 40 * and wait for the pending answer, with timeouts. 41 */ 42 43 #ifndef OUTSIDE_NETWORK_H 44 #define OUTSIDE_NETWORK_H 45 46 #include "util/rbtree.h" 47 #include "util/netevent.h" 48 #include "dnstap/dnstap_config.h" 49 struct pending; 50 struct pending_timeout; 51 struct ub_randstate; 52 struct pending_tcp; 53 struct waiting_tcp; 54 struct waiting_udp; 55 struct infra_cache; 56 struct port_comm; 57 struct port_if; 58 struct sldns_buffer; 59 struct serviced_query; 60 struct dt_env; 61 62 /** 63 * Send queries to outside servers and wait for answers from servers. 64 * Contains answer-listen sockets. 65 */ 66 struct outside_network { 67 /** Base for select calls */ 68 struct comm_base* base; 69 /** pointer to time in seconds */ 70 time_t* now_secs; 71 /** pointer to time in microseconds */ 72 struct timeval* now_tv; 73 74 /** buffer shared by UDP connections, since there is only one 75 datagram at any time. */ 76 struct sldns_buffer* udp_buff; 77 /** serviced_callbacks malloc overhead when processing multiple 78 * identical serviced queries to the same server. */ 79 size_t svcd_overhead; 80 /** use x20 bits to encode additional ID random bits */ 81 int use_caps_for_id; 82 /** outside network wants to quit. Stop queued msgs from sent. */ 83 int want_to_quit; 84 85 /** number of unwanted replies received (for statistics) */ 86 size_t unwanted_replies; 87 /** cumulative total of unwanted replies (for defense) */ 88 size_t unwanted_total; 89 /** threshold when to take defensive action. If 0 then never. */ 90 size_t unwanted_threshold; 91 /** what action to take, called when defensive action is needed */ 92 void (*unwanted_action)(void*); 93 /** user param for action */ 94 void* unwanted_param; 95 96 /** linked list of available commpoints, unused file descriptors, 97 * for use as outgoing UDP ports. cp.fd=-1 in them. */ 98 struct port_comm* unused_fds; 99 /** if udp is done */ 100 int do_udp; 101 /** if udp is delay-closed (delayed answers do not meet closed port)*/ 102 int delayclose; 103 /** timeout for delayclose */ 104 struct timeval delay_tv; 105 106 /** array of outgoing IP4 interfaces */ 107 struct port_if* ip4_ifs; 108 /** number of outgoing IP4 interfaces */ 109 int num_ip4; 110 111 /** array of outgoing IP6 interfaces */ 112 struct port_if* ip6_ifs; 113 /** number of outgoing IP6 interfaces */ 114 int num_ip6; 115 116 /** pending udp queries waiting to be sent out, waiting for fd */ 117 struct pending* udp_wait_first; 118 /** last pending udp query in list */ 119 struct pending* udp_wait_last; 120 121 /** pending udp answers. sorted by id, addr */ 122 rbtree_t* pending; 123 /** serviced queries, sorted by qbuf, addr, dnssec */ 124 rbtree_t* serviced; 125 /** host cache, pointer but not owned by outnet. */ 126 struct infra_cache* infra; 127 /** where to get random numbers */ 128 struct ub_randstate* rnd; 129 /** ssl context to create ssl wrapped TCP with DNS connections */ 130 void* sslctx; 131 #ifdef USE_DNSTAP 132 /** dnstap environment */ 133 struct dt_env* dtenv; 134 #endif 135 /** maximum segment size of tcp socket */ 136 int tcp_mss; 137 138 /** 139 * Array of tcp pending used for outgoing TCP connections. 140 * Each can be used to establish a TCP connection with a server. 141 * The file descriptors are -1 if they are free, and need to be 142 * opened for the tcp connection. Can be used for ip4 and ip6. 143 */ 144 struct pending_tcp **tcp_conns; 145 /** number of tcp communication points. */ 146 size_t num_tcp; 147 /** number of tcp communication points in use. */ 148 size_t num_tcp_outgoing; 149 /** list of tcp comm points that are free for use */ 150 struct pending_tcp* tcp_free; 151 /** list of tcp queries waiting for a buffer */ 152 struct waiting_tcp* tcp_wait_first; 153 /** last of waiting query list */ 154 struct waiting_tcp* tcp_wait_last; 155 }; 156 157 /** 158 * Outgoing interface. Ports available and currently used are tracked 159 * per interface 160 */ 161 struct port_if { 162 /** address ready to allocate new socket (except port no). */ 163 struct sockaddr_storage addr; 164 /** length of addr field */ 165 socklen_t addrlen; 166 167 /** the available ports array. These are unused. 168 * Only the first total-inuse part is filled. */ 169 int* avail_ports; 170 /** the total number of available ports (size of the array) */ 171 int avail_total; 172 173 /** array of the commpoints currently in use. 174 * allocated for max number of fds, first part in use. */ 175 struct port_comm** out; 176 /** max number of fds, size of out array */ 177 int maxout; 178 /** number of commpoints (and thus also ports) in use */ 179 int inuse; 180 }; 181 182 /** 183 * Outgoing commpoint for UDP port. 184 */ 185 struct port_comm { 186 /** next in free list */ 187 struct port_comm* next; 188 /** which port number (when in use) */ 189 int number; 190 /** interface it is used in */ 191 struct port_if* pif; 192 /** index in the out array of the interface */ 193 int index; 194 /** number of outstanding queries on this port */ 195 int num_outstanding; 196 /** UDP commpoint, fd=-1 if not in use */ 197 struct comm_point* cp; 198 }; 199 200 /** 201 * A query that has an answer pending for it. 202 */ 203 struct pending { 204 /** redblacktree entry, key is the pending struct(id, addr). */ 205 rbnode_t node; 206 /** the ID for the query. int so that a value out of range can 207 * be used to signify a pending that is for certain not present in 208 * the rbtree. (and for which deletion is safe). */ 209 unsigned int id; 210 /** remote address. */ 211 struct sockaddr_storage addr; 212 /** length of addr field in use. */ 213 socklen_t addrlen; 214 /** comm point it was sent on (and reply must come back on). */ 215 struct port_comm* pc; 216 /** timeout event */ 217 struct comm_timer* timer; 218 /** callback for the timeout, error or reply to the message */ 219 comm_point_callback_t* cb; 220 /** callback user argument */ 221 void* cb_arg; 222 /** the outside network it is part of */ 223 struct outside_network* outnet; 224 /** the corresponding serviced_query */ 225 struct serviced_query* sq; 226 227 /*---- filled if udp pending is waiting -----*/ 228 /** next in waiting list. */ 229 struct pending* next_waiting; 230 /** timeout in msec */ 231 int timeout; 232 /** The query itself, the query packet to send. */ 233 uint8_t* pkt; 234 /** length of query packet. */ 235 size_t pkt_len; 236 }; 237 238 /** 239 * Pending TCP query to server. 240 */ 241 struct pending_tcp { 242 /** next in list of free tcp comm points, or NULL. */ 243 struct pending_tcp* next_free; 244 /** the ID for the query; checked in reply */ 245 uint16_t id; 246 /** tcp comm point it was sent on (and reply must come back on). */ 247 struct comm_point* c; 248 /** the query being serviced, NULL if the pending_tcp is unused. */ 249 struct waiting_tcp* query; 250 }; 251 252 /** 253 * Query waiting for TCP buffer. 254 */ 255 struct waiting_tcp { 256 /** 257 * next in waiting list. 258 * if pkt==0, this points to the pending_tcp structure. 259 */ 260 struct waiting_tcp* next_waiting; 261 /** timeout event; timer keeps running whether the query is 262 * waiting for a buffer or the tcp reply is pending */ 263 struct comm_timer* timer; 264 /** the outside network it is part of */ 265 struct outside_network* outnet; 266 /** remote address. */ 267 struct sockaddr_storage addr; 268 /** length of addr field in use. */ 269 socklen_t addrlen; 270 /** 271 * The query itself, the query packet to send. 272 * allocated after the waiting_tcp structure. 273 * set to NULL when the query is serviced and it part of pending_tcp. 274 * if this is NULL, the next_waiting points to the pending_tcp. 275 */ 276 uint8_t* pkt; 277 /** length of query packet. */ 278 size_t pkt_len; 279 /** callback for the timeout, error or reply to the message */ 280 comm_point_callback_t* cb; 281 /** callback user argument */ 282 void* cb_arg; 283 /** if it uses ssl upstream */ 284 int ssl_upstream; 285 }; 286 287 /** 288 * Callback to party interested in serviced query results. 289 */ 290 struct service_callback { 291 /** next in callback list */ 292 struct service_callback* next; 293 /** callback function */ 294 comm_point_callback_t* cb; 295 /** user argument for callback function */ 296 void* cb_arg; 297 }; 298 299 /** fallback size for fragmentation for EDNS in IPv4 */ 300 #define EDNS_FRAG_SIZE_IP4 1472 301 /** fallback size for EDNS in IPv6, fits one fragment with ip6-tunnel-ids */ 302 #define EDNS_FRAG_SIZE_IP6 1232 303 304 /** 305 * Query service record. 306 * Contains query and destination. UDP, TCP, EDNS are all tried. 307 * complete with retries and timeouts. A number of interested parties can 308 * receive a callback. 309 */ 310 struct serviced_query { 311 /** The rbtree node, key is this record */ 312 rbnode_t node; 313 /** The query that needs to be answered. Starts with flags u16, 314 * then qdcount, ..., including qname, qtype, qclass. Does not include 315 * EDNS record. */ 316 uint8_t* qbuf; 317 /** length of qbuf. */ 318 size_t qbuflen; 319 /** If an EDNS section is included, the DO/CD bit will be turned on. */ 320 int dnssec; 321 /** We want signatures, or else the answer is likely useless */ 322 int want_dnssec; 323 /** ignore capsforid */ 324 int nocaps; 325 /** tcp upstream used, use tcp, or ssl_upstream for SSL */ 326 int tcp_upstream, ssl_upstream; 327 /** where to send it */ 328 struct sockaddr_storage addr; 329 /** length of addr field in use. */ 330 socklen_t addrlen; 331 /** zone name, uncompressed domain name in wireformat */ 332 uint8_t* zone; 333 /** length of zone name */ 334 size_t zonelen; 335 /** qtype */ 336 int qtype; 337 /** current status */ 338 enum serviced_query_status { 339 /** initial status */ 340 serviced_initial, 341 /** UDP with EDNS sent */ 342 serviced_query_UDP_EDNS, 343 /** UDP without EDNS sent */ 344 serviced_query_UDP, 345 /** TCP with EDNS sent */ 346 serviced_query_TCP_EDNS, 347 /** TCP without EDNS sent */ 348 serviced_query_TCP, 349 /** probe to test EDNS lameness (EDNS is dropped) */ 350 serviced_query_PROBE_EDNS, 351 /** probe to test noEDNS0 (EDNS gives FORMERRorNOTIMP) */ 352 serviced_query_UDP_EDNS_fallback, 353 /** probe to test TCP noEDNS0 (EDNS gives FORMERRorNOTIMP) */ 354 serviced_query_TCP_EDNS_fallback, 355 /** send UDP query with EDNS1480 (or 1280) */ 356 serviced_query_UDP_EDNS_FRAG 357 } 358 /** variable with current status */ 359 status; 360 /** true if serviced_query is scheduled for deletion already */ 361 int to_be_deleted; 362 /** number of UDP retries */ 363 int retry; 364 /** time last UDP was sent */ 365 struct timeval last_sent_time; 366 /** rtt of last (UDP) message */ 367 int last_rtt; 368 /** do we know edns probe status already, for UDP_EDNS queries */ 369 int edns_lame_known; 370 /** outside network this is part of */ 371 struct outside_network* outnet; 372 /** list of interested parties that need callback on results. */ 373 struct service_callback* cblist; 374 /** the UDP or TCP query that is pending, see status which */ 375 void* pending; 376 }; 377 378 /** 379 * Create outside_network structure with N udp ports. 380 * @param base: the communication base to use for event handling. 381 * @param bufsize: size for network buffers. 382 * @param num_ports: number of udp ports to open per interface. 383 * @param ifs: interface names (or NULL for default interface). 384 * These interfaces must be able to access all authoritative servers. 385 * @param num_ifs: number of names in array ifs. 386 * @param do_ip4: service IP4. 387 * @param do_ip6: service IP6. 388 * @param num_tcp: number of outgoing tcp buffers to preallocate. 389 * @param infra: pointer to infra cached used for serviced queries. 390 * @param rnd: stored to create random numbers for serviced queries. 391 * @param use_caps_for_id: enable to use 0x20 bits to encode id randomness. 392 * @param availports: array of available ports. 393 * @param numavailports: number of available ports in array. 394 * @param unwanted_threshold: when to take defensive action. 395 * @param unwanted_action: the action to take. 396 * @param unwanted_param: user parameter to action. 397 * @param tcp_mss: maximum segment size of tcp socket. 398 * @param do_udp: if udp is done. 399 * @param sslctx: context to create outgoing connections with (if enabled). 400 * @param delayclose: if not 0, udp sockets are delayed before timeout closure. 401 * msec to wait on timeouted udp sockets. 402 * @param dtenv: environment to send dnstap events with (if enabled). 403 * @return: the new structure (with no pending answers) or NULL on error. 404 */ 405 struct outside_network* outside_network_create(struct comm_base* base, 406 size_t bufsize, size_t num_ports, char** ifs, int num_ifs, 407 int do_ip4, int do_ip6, size_t num_tcp, struct infra_cache* infra, 408 struct ub_randstate* rnd, int use_caps_for_id, int* availports, 409 int numavailports, size_t unwanted_threshold, int tcp_mss, 410 void (*unwanted_action)(void*), void* unwanted_param, int do_udp, 411 void* sslctx, int delayclose, struct dt_env *dtenv); 412 413 /** 414 * Delete outside_network structure. 415 * @param outnet: object to delete. 416 */ 417 void outside_network_delete(struct outside_network* outnet); 418 419 /** 420 * Prepare for quit. Sends no more queries, even if queued up. 421 * @param outnet: object to prepare for removal 422 */ 423 void outside_network_quit_prepare(struct outside_network* outnet); 424 425 /** 426 * Send UDP query, create pending answer. 427 * Changes the ID for the query to be random and unique for that destination. 428 * @param sq: serviced query. 429 * @param packet: wireformat query to send to destination. 430 * @param timeout: in milliseconds from now. 431 * @param callback: function to call on error, timeout or reply. 432 * @param callback_arg: user argument for callback function. 433 * @return: NULL on error for malloc or socket. Else the pending query object. 434 */ 435 struct pending* pending_udp_query(struct serviced_query* sq, 436 struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback, 437 void* callback_arg); 438 439 /** 440 * Send TCP query. May wait for TCP buffer. Selects ID to be random, and 441 * checks id. 442 * @param sq: serviced query. 443 * @param packet: wireformat query to send to destination. copied from. 444 * @param timeout: in seconds from now. 445 * Timer starts running now. Timer may expire if all buffers are used, 446 * without any query been sent to the server yet. 447 * @param callback: function to call on error, timeout or reply. 448 * @param callback_arg: user argument for callback function. 449 * @return: false on error for malloc or socket. Else the pending TCP object. 450 */ 451 struct waiting_tcp* pending_tcp_query(struct serviced_query* sq, 452 struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback, 453 void* callback_arg); 454 455 /** 456 * Delete pending answer. 457 * @param outnet: outside network the pending query is part of. 458 * Internal feature: if outnet is NULL, p is not unlinked from rbtree. 459 * @param p: deleted 460 */ 461 void pending_delete(struct outside_network* outnet, struct pending* p); 462 463 /** 464 * Perform a serviced query to the authoritative servers. 465 * Duplicate efforts are detected, and EDNS, TCP and UDP retry is performed. 466 * @param outnet: outside network, with rbtree of serviced queries. 467 * @param qname: what qname to query. 468 * @param qnamelen: length of qname in octets including 0 root label. 469 * @param qtype: rrset type to query (host format) 470 * @param qclass: query class. (host format) 471 * @param flags: flags u16 (host format), includes opcode, CD bit. 472 * @param dnssec: if set, DO bit is set in EDNS queries. 473 * If the value includes BIT_CD, CD bit is set when in EDNS queries. 474 * If the value includes BIT_DO, DO bit is set when in EDNS queries. 475 * @param want_dnssec: signatures are needed, without EDNS the answer is 476 * likely to be useless. 477 * @param nocaps: ignore use_caps_for_id and use unperturbed qname. 478 * @param tcp_upstream: use TCP for upstream queries. 479 * @param ssl_upstream: use SSL for upstream queries. 480 * @param callback: callback function. 481 * @param callback_arg: user argument to callback function. 482 * @param addr: to which server to send the query. 483 * @param addrlen: length of addr. 484 * @param zone: name of the zone of the delegation point. wireformat dname. 485 This is the delegation point name for which the server is deemed 486 authoritative. 487 * @param zonelen: length of zone. 488 * @param buff: scratch buffer to create query contents in. Empty on exit. 489 * @return 0 on error, or pointer to serviced query that is used to answer 490 * this serviced query may be shared with other callbacks as well. 491 */ 492 struct serviced_query* outnet_serviced_query(struct outside_network* outnet, 493 uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, 494 uint16_t flags, int dnssec, int want_dnssec, int nocaps, 495 int tcp_upstream, int ssl_upstream, struct sockaddr_storage* addr, 496 socklen_t addrlen, uint8_t* zone, size_t zonelen, 497 comm_point_callback_t* callback, void* callback_arg, 498 struct sldns_buffer* buff); 499 500 /** 501 * Remove service query callback. 502 * If that leads to zero callbacks, the query is completely cancelled. 503 * @param sq: serviced query to adjust. 504 * @param cb_arg: callback argument of callback that needs removal. 505 * same as the callback_arg to outnet_serviced_query(). 506 */ 507 void outnet_serviced_query_stop(struct serviced_query* sq, void* cb_arg); 508 509 /** 510 * Get memory size in use by outside network. 511 * Counts buffers and outstanding query (serviced queries) malloced data. 512 * @param outnet: outside network structure. 513 * @return size in bytes. 514 */ 515 size_t outnet_get_mem(struct outside_network* outnet); 516 517 /** 518 * Get memory size in use by serviced query while it is servicing callbacks. 519 * This takes into account the pre-deleted status of it; it will be deleted 520 * when the callbacks are done. 521 * @param sq: serviced query. 522 * @return size in bytes. 523 */ 524 size_t serviced_get_mem(struct serviced_query* sq); 525 526 /** callback for incoming udp answers from the network */ 527 int outnet_udp_cb(struct comm_point* c, void* arg, int error, 528 struct comm_reply *reply_info); 529 530 /** callback for pending tcp connections */ 531 int outnet_tcp_cb(struct comm_point* c, void* arg, int error, 532 struct comm_reply *reply_info); 533 534 /** callback for udp timeout */ 535 void pending_udp_timer_cb(void *arg); 536 537 /** callback for udp delay for timeout */ 538 void pending_udp_timer_delay_cb(void *arg); 539 540 /** callback for outgoing TCP timer event */ 541 void outnet_tcptimer(void* arg); 542 543 /** callback for serviced query UDP answers */ 544 int serviced_udp_callback(struct comm_point* c, void* arg, int error, 545 struct comm_reply* rep); 546 547 /** TCP reply or error callback for serviced queries */ 548 int serviced_tcp_callback(struct comm_point* c, void* arg, int error, 549 struct comm_reply* rep); 550 551 /** compare function of pending rbtree */ 552 int pending_cmp(const void* key1, const void* key2); 553 554 /** compare function of serviced query rbtree */ 555 int serviced_cmp(const void* key1, const void* key2); 556 557 #endif /* OUTSIDE_NETWORK_H */ 558