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