1 /* 2 * util/module.h - DNS handling module interface 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 contains the interface for DNS handling modules. 40 * 41 * The module interface uses the DNS modules as state machines. The 42 * state machines are activated in sequence to operate on queries. Once 43 * they are done, the reply is passed back. In the usual setup the mesh 44 * is the caller of the state machines and once things are done sends replies 45 * and invokes result callbacks. 46 * 47 * The module provides a number of functions, listed in the module_func_block. 48 * The module is inited and destroyed and memory usage queries, for the 49 * module as a whole, for entire-module state (such as a cache). And per-query 50 * functions are called, operate to move the state machine and cleanup of 51 * the per-query state. 52 * 53 * Most per-query state should simply be allocated in the query region. 54 * This is destroyed at the end of the query. 55 * 56 * The module environment contains services and information and caches 57 * shared by the modules and the rest of the system. It also contains 58 * function pointers for module-specific tasks (like sending queries). 59 * 60 * *** Example module calls for a normal query 61 * 62 * In this example, the query does not need recursion, all the other data 63 * can be found in the cache. This makes the example shorter. 64 * 65 * At the start of the program the iterator module is initialised. 66 * The iterator module sets up its global state, such as donotquery lists 67 * and private address trees. 68 * 69 * A query comes in, and a mesh entry is created for it. The mesh 70 * starts the resolution process. The validator module is the first 71 * in the list of modules, and it is started on this new query. The 72 * operate() function is called. The validator decides it needs not do 73 * anything yet until there is a result and returns wait_module, that 74 * causes the next module in the list to be started. 75 * 76 * The next module is the iterator. It is started on the passed query and 77 * decides to perform a lookup. For this simple example, the delegation 78 * point information is available, and all the iterator wants to do is 79 * send a UDP query. The iterator uses env.send_query() to send the 80 * query. Then the iterator suspends (returns from the operate call). 81 * 82 * When the UDP reply comes back (and on errors and timeouts), the 83 * operate function is called for the query, on the iterator module, 84 * with the event that there is a reply. The iterator decides that this 85 * is enough, the work is done. It returns the value finished from the 86 * operate call, which causes the previous module to be started. 87 * 88 * The previous module, the validator module, is started with the event 89 * that the iterator module is done. The validator decides to validate 90 * the query. Once it is done (which could take recursive lookups, but 91 * in this example no recursive lookups are needed), it returns from the 92 * operate function with finished. 93 * 94 * There is no previous module from the validator module, and the mesh 95 * takes this to mean that the query is finally done. The mesh invokes 96 * callbacks and sends packets to queriers. 97 * 98 * If other modules had been waiting (recursively) on the answer to this 99 * query, then the mesh will tell them about it. It calls the inform_super 100 * routine on all the waiting modules, and once that is done it calls all of 101 * them with the operate() call. During inform_super the query that is done 102 * still exists and information can be copied from it (but the module should 103 * not really re-entry codepoints and services). During the operate call 104 * the modules can use stored state to continue operation with the results. 105 * (network buffers are used to contain the answer packet during the 106 * inform_super phase, but after that the network buffers will be cleared 107 * of their contents so that other tasks can be performed). 108 * 109 * *** Example module calls for recursion 110 * 111 * A module is called in operate, and it decides that it wants to perform 112 * recursion. That is, it wants the full state-machine-list to operate on 113 * a different query. It calls env.attach_sub() to create a new query state. 114 * The routine returns the newly created state, and potentially the module 115 * can edit the module-states for the newly created query (i.e. pass along 116 * some information, like delegation points). The module then suspends, 117 * returns from the operate routine. 118 * 119 * The mesh meanwhile will have the newly created query (or queries) on 120 * a waiting list, and will call operate() on this query (or queries). 121 * It starts again at the start of the module list for them. The query 122 * (or queries) continue to operate their state machines, until they are 123 * done. When they are done the mesh calls inform_super on the module that 124 * wanted the recursion. After that the mesh calls operate() on the module 125 * that wanted to do the recursion, and during this phase the module could, 126 * for example, decide to create more recursions. 127 * 128 * If the module decides it no longer wants the recursive information 129 * it can call detach_subs. Those queries will still run to completion, 130 * potentially filling the cache with information. Inform_super is not 131 * called any more. 132 * 133 * The iterator module will fetch items from the cache, so a recursion 134 * attempt may complete very quickly if the item is in cache. The calling 135 * module has to wait for completion or eventual timeout. A recursive query 136 * that times out returns a servfail rcode (servfail is also returned for 137 * other errors during the lookup). 138 * 139 * Results are passed in the qstate, the rcode member is used to pass 140 * errors without requiring memory allocation, so that the code can continue 141 * in out-of-memory conditions. If the rcode member is 0 (NOERROR) then 142 * the dns_msg entry contains a filled out message. This message may 143 * also contain an rcode that is nonzero, but in this case additional 144 * information (query, additional) can be passed along. 145 * 146 * The rcode and dns_msg are used to pass the result from the rightmost 147 * module towards the leftmost modules and then towards the user. 148 * 149 * If you want to avoid recursion-cycles where queries need other queries 150 * that need the first one, use detect_cycle() to see if that will happen. 151 * 152 */ 153 154 #ifndef UTIL_MODULE_H 155 #define UTIL_MODULE_H 156 #include "util/storage/lruhash.h" 157 #include "util/data/msgreply.h" 158 #include "util/data/msgparse.h" 159 struct sldns_buffer; 160 struct alloc_cache; 161 struct rrset_cache; 162 struct key_cache; 163 struct config_file; 164 struct slabhash; 165 struct query_info; 166 struct edns_data; 167 struct regional; 168 struct worker; 169 struct comm_base; 170 struct auth_zones; 171 struct outside_network; 172 struct module_qstate; 173 struct ub_randstate; 174 struct mesh_area; 175 struct mesh_state; 176 struct val_anchors; 177 struct val_neg_cache; 178 struct iter_forwards; 179 struct iter_hints; 180 struct views; 181 struct respip_set; 182 struct respip_client_info; 183 struct respip_addr_info; 184 struct module_stack; 185 186 /** Maximum number of modules in operation */ 187 #define MAX_MODULE 16 188 189 /** Maximum number of known edns options */ 190 #define MAX_KNOWN_EDNS_OPTS 256 191 192 struct errinf_strlist { 193 /** next item in list */ 194 struct errinf_strlist* next; 195 /** config option string */ 196 char* str; 197 /** EDE code companion to the error str */ 198 int reason_bogus; 199 }; 200 201 enum inplace_cb_list_type { 202 /* Inplace callbacks for when a resolved reply is ready to be sent to the 203 * front.*/ 204 inplace_cb_reply = 0, 205 /* Inplace callbacks for when a reply is given from the cache. */ 206 inplace_cb_reply_cache, 207 /* Inplace callbacks for when a reply is given with local data 208 * (or Chaos reply). */ 209 inplace_cb_reply_local, 210 /* Inplace callbacks for when the reply is servfail. */ 211 inplace_cb_reply_servfail, 212 /* Inplace callbacks for when a query is ready to be sent to the back.*/ 213 inplace_cb_query, 214 /* Inplace callback for when a reply is received from the back. */ 215 inplace_cb_query_response, 216 /* Inplace callback for when EDNS is parsed on a reply received from the 217 * back. */ 218 inplace_cb_edns_back_parsed, 219 /* Total number of types. Used for array initialization. 220 * Should always be last. */ 221 inplace_cb_types_total 222 }; 223 224 225 /** Known edns option. Can be populated during modules' init. */ 226 struct edns_known_option { 227 /** type of this edns option */ 228 uint16_t opt_code; 229 /** whether the option needs to bypass the cache stage */ 230 int bypass_cache_stage; 231 /** whether the option needs mesh aggregation */ 232 int no_aggregation; 233 }; 234 235 /** 236 * Inplace callback list of registered routines to be called. 237 */ 238 struct inplace_cb { 239 /** next in list */ 240 struct inplace_cb* next; 241 /** Inplace callback routine */ 242 void* cb; 243 void* cb_arg; 244 /** module id */ 245 int id; 246 }; 247 248 /** 249 * Inplace callback function called before replying. 250 * Called as func(qinfo, qstate, rep, rcode, edns, opt_list_out, repinfo, 251 * region, id, python_callback) 252 * Where: 253 * qinfo: the query info. 254 * qstate: the module state. NULL when calling before the query reaches the 255 * mesh states. 256 * rep: reply_info. Could be NULL. 257 * rcode: the return code. 258 * edns: the edns_data of the reply. When qstate is NULL, it is also used as 259 * the edns input. 260 * opt_list_out: the edns options list for the reply. 261 * repinfo: reply information for a communication point. NULL when calling 262 * during the mesh states; the same could be found from 263 * qstate->mesh_info->reply_list. 264 * region: region to store data. 265 * id: module id. 266 * python_callback: only used for registering a python callback function. 267 */ 268 typedef int inplace_cb_reply_func_type(struct query_info* qinfo, 269 struct module_qstate* qstate, struct reply_info* rep, int rcode, 270 struct edns_data* edns, struct edns_option** opt_list_out, 271 struct comm_reply* repinfo, struct regional* region, 272 struct timeval* start_time, int id, void* callback); 273 274 /** 275 * Inplace callback function called before sending the query to a nameserver. 276 * Called as func(qinfo, flags, qstate, addr, addrlen, zone, zonelen, region, 277 * id, python_callback) 278 * Where: 279 * qinfo: query info. 280 * flags: flags of the query. 281 * qstate: query state. 282 * addr: to which server to send the query. 283 * addrlen: length of addr. 284 * zone: name of the zone of the delegation point. wireformat dname. 285 * This is the delegation point name for which the server is deemed 286 * authoritative. 287 * zonelen: length of zone. 288 * region: region to store data. 289 * id: module id. 290 * python_callback: only used for registering a python callback function. 291 */ 292 typedef int inplace_cb_query_func_type(struct query_info* qinfo, uint16_t flags, 293 struct module_qstate* qstate, struct sockaddr_storage* addr, 294 socklen_t addrlen, uint8_t* zone, size_t zonelen, struct regional* region, 295 int id, void* callback); 296 297 /** 298 * Inplace callback function called after parsing edns on query reply. 299 * Called as func(qstate, id, cb_args) 300 * Where: 301 * qstate: the query state. 302 * id: module id. 303 * cb_args: argument passed when registering callback. 304 */ 305 typedef int inplace_cb_edns_back_parsed_func_type(struct module_qstate* qstate, 306 int id, void* cb_args); 307 308 /** 309 * Inplace callback function called after parsing query response. 310 * Called as func(qstate, response, id, cb_args) 311 * Where: 312 * qstate: the query state. 313 * response: query response. 314 * id: module id. 315 * cb_args: argument passed when registering callback. 316 */ 317 typedef int inplace_cb_query_response_func_type(struct module_qstate* qstate, 318 struct dns_msg* response, int id, void* cb_args); 319 320 /** 321 * Function called when looking for (expired) cached answers during the serve 322 * expired logic. 323 * Called as func(qstate, lookup_qinfo, &is_expired) 324 * Where: 325 * qstate: the query state. 326 * lookup_qinfo: the qinfo to lookup for. 327 * is_expired: set if the cached answer is expired. 328 */ 329 typedef struct dns_msg* serve_expired_lookup_func_type( 330 struct module_qstate* qstate, struct query_info* lookup_qinfo, 331 int* is_expired); 332 333 /** 334 * Module environment. 335 * Services and data provided to the module. 336 */ 337 struct module_env { 338 /* --- data --- */ 339 /** config file with config options */ 340 struct config_file* cfg; 341 /** shared message cache */ 342 struct slabhash* msg_cache; 343 /** shared rrset cache */ 344 struct rrset_cache* rrset_cache; 345 /** shared infrastructure cache (edns, lameness) */ 346 struct infra_cache* infra_cache; 347 /** shared key cache */ 348 struct key_cache* key_cache; 349 350 /* --- services --- */ 351 /** 352 * Send serviced DNS query to server. UDP/TCP and EDNS is handled. 353 * operate() should return with wait_reply. Later on a callback 354 * will cause operate() to be called with event timeout or reply. 355 * The time until a timeout is calculated from roundtrip timing, 356 * several UDP retries are attempted. 357 * @param qinfo: query info. 358 * @param flags: host order flags word, with opcode and CD bit. 359 * @param dnssec: if set, EDNS record will have bits set. 360 * If EDNS_DO bit is set, DO bit is set in EDNS records. 361 * If BIT_CD is set, CD bit is set in queries with EDNS records. 362 * @param want_dnssec: if set, the validator wants DNSSEC. Without 363 * EDNS, the answer is likely to be useless for this domain. 364 * @param nocaps: do not use caps_for_id, use the qname as given. 365 * (ignored if caps_for_id is disabled). 366 * @param check_ratelimit: if set, will check ratelimit before sending out. 367 * @param addr: where to. 368 * @param addrlen: length of addr. 369 * @param zone: delegation point name. 370 * @param zonelen: length of zone name. 371 * @param tcp_upstream: use TCP for upstream queries. 372 * @param ssl_upstream: use SSL for upstream queries. 373 * @param tls_auth_name: if ssl_upstream, use this name with TLS 374 * authentication. 375 * @param q: which query state to reactivate upon return. 376 * @param was_ratelimited: it will signal back if the query failed to pass the 377 * ratelimit check. 378 * @return: false on failure (memory or socket related). no query was 379 * sent. Or returns an outbound entry with qsent and qstate set. 380 * This outbound_entry will be used on later module invocations 381 * that involve this query (timeout, error or reply). 382 */ 383 struct outbound_entry* (*send_query)(struct query_info* qinfo, 384 uint16_t flags, int dnssec, int want_dnssec, int nocaps, 385 int check_ratelimit, 386 struct sockaddr_storage* addr, socklen_t addrlen, 387 uint8_t* zone, size_t zonelen, int tcp_upstream, int ssl_upstream, 388 char* tls_auth_name, struct module_qstate* q, int* was_ratelimited); 389 390 /** 391 * Detach-subqueries. 392 * Remove all sub-query references from this query state. 393 * Keeps super-references of those sub-queries correct. 394 * Updates stat items in mesh_area structure. 395 * @param qstate: used to find mesh state. 396 */ 397 void (*detach_subs)(struct module_qstate* qstate); 398 399 /** 400 * Attach subquery. 401 * Creates it if it does not exist already. 402 * Keeps sub and super references correct. 403 * Updates stat items in mesh_area structure. 404 * Pass if it is priming query or not. 405 * return: 406 * o if error (malloc) happened. 407 * o need to initialise the new state (module init; it is a new state). 408 * so that the next run of the query with this module is successful. 409 * o no init needed, attachment successful. 410 * 411 * @param qstate: the state to find mesh state, and that wants to 412 * receive the results from the new subquery. 413 * @param qinfo: what to query for (copied). 414 * @param qflags: what flags to use (RD, CD flag or not). 415 * @param prime: if it is a (stub) priming query. 416 * @param valrec: validation lookup recursion, does not need validation 417 * @param newq: If the new subquery needs initialisation, it is 418 * returned, otherwise NULL is returned. 419 * @return: false on error, true if success (and init may be needed). 420 */ 421 int (*attach_sub)(struct module_qstate* qstate, 422 struct query_info* qinfo, uint16_t qflags, int prime, 423 int valrec, struct module_qstate** newq); 424 425 /** 426 * Add detached query. 427 * Creates it if it does not exist already. 428 * Does not make super/sub references. 429 * Performs a cycle detection - for double check - and fails if there is 430 * one. 431 * Updates stat items in mesh_area structure. 432 * Pass if it is priming query or not. 433 * return: 434 * o if error (malloc) happened. 435 * o need to initialise the new state (module init; it is a new state). 436 * so that the next run of the query with this module is successful. 437 * o no init needed, attachment successful. 438 * o added subquery, created if it did not exist already. 439 * 440 * @param qstate: the state to find mesh state, and that wants to receive 441 * the results from the new subquery. 442 * @param qinfo: what to query for (copied). 443 * @param qflags: what flags to use (RD / CD flag or not). 444 * @param prime: if it is a (stub) priming query. 445 * @param valrec: if it is a validation recursion query (lookup of key, DS). 446 * @param newq: If the new subquery needs initialisation, it is returned, 447 * otherwise NULL is returned. 448 * @param sub: The added mesh state, created if it did not exist already. 449 * @return: false on error, true if success (and init may be needed). 450 */ 451 int (*add_sub)(struct module_qstate* qstate, 452 struct query_info* qinfo, uint16_t qflags, int prime, 453 int valrec, struct module_qstate** newq, 454 struct mesh_state** sub); 455 456 /** 457 * Kill newly attached sub. If attach_sub returns newq for 458 * initialisation, but that fails, then this routine will cleanup and 459 * delete the freshly created sub. 460 * @param newq: the new subquery that is no longer needed. 461 * It is removed. 462 */ 463 void (*kill_sub)(struct module_qstate* newq); 464 465 /** 466 * Detect if adding a dependency for qstate on name,type,class will 467 * create a dependency cycle. 468 * @param qstate: given mesh querystate. 469 * @param qinfo: query info for dependency. 470 * @param flags: query flags of dependency, RD/CD flags. 471 * @param prime: if dependency is a priming query or not. 472 * @param valrec: validation lookup recursion, does not need validation 473 * @return true if the name,type,class exists and the given 474 * qstate mesh exists as a dependency of that name. Thus 475 * if qstate becomes dependent on name,type,class then a 476 * cycle is created. 477 */ 478 int (*detect_cycle)(struct module_qstate* qstate, 479 struct query_info* qinfo, uint16_t flags, int prime, 480 int valrec); 481 482 /** region for temporary usage. May be cleared after operate() call. */ 483 struct regional* scratch; 484 /** buffer for temporary usage. May be cleared after operate() call. */ 485 struct sldns_buffer* scratch_buffer; 486 /** internal data for daemon - worker thread. */ 487 struct worker* worker; 488 /** the worker event base */ 489 struct comm_base* worker_base; 490 /** the outside network */ 491 struct outside_network* outnet; 492 /** mesh area with query state dependencies */ 493 struct mesh_area* mesh; 494 /** allocation service */ 495 struct alloc_cache* alloc; 496 /** random table to generate random numbers */ 497 struct ub_randstate* rnd; 498 /** time in seconds, converted to integer */ 499 time_t* now; 500 /** time in microseconds. Relatively recent. */ 501 struct timeval* now_tv; 502 /** is validation required for messages, controls client-facing 503 * validation status (AD bits) and servfails */ 504 int need_to_validate; 505 /** trusted key storage; these are the configured keys, if not NULL, 506 * otherwise configured by validator. These are the trust anchors, 507 * and are not primed and ready for validation, but on the bright 508 * side, they are read only memory, thus no locks and fast. */ 509 struct val_anchors* anchors; 510 /** negative cache, configured by the validator. if not NULL, 511 * contains NSEC record lookup trees. */ 512 struct val_neg_cache* neg_cache; 513 /** the 5011-probe timer (if any) */ 514 struct comm_timer* probe_timer; 515 /** auth zones */ 516 struct auth_zones* auth_zones; 517 /** Mapping of forwarding zones to targets. 518 * iterator forwarder information. */ 519 struct iter_forwards* fwds; 520 /** 521 * iterator stub information. 522 * The hints -- these aren't stored in the cache because they don't 523 * expire. The hints are always used to "prime" the cache. Note 524 * that both root hints and stub zone "hints" are stored in this 525 * data structure. 526 */ 527 struct iter_hints* hints; 528 /** views structure containing view tree */ 529 struct views* views; 530 /** response-ip set with associated actions and tags. */ 531 struct respip_set* respip_set; 532 /** module specific data. indexed by module id. */ 533 void* modinfo[MAX_MODULE]; 534 535 /* Shared linked list of inplace callback functions */ 536 struct inplace_cb* inplace_cb_lists[inplace_cb_types_total]; 537 538 /** 539 * Shared array of known edns options (size MAX_KNOWN_EDNS_OPTS). 540 * Filled by edns literate modules during init. 541 */ 542 struct edns_known_option* edns_known_options; 543 /* Number of known edns options */ 544 size_t edns_known_options_num; 545 /** EDNS client string information */ 546 struct edns_strings* edns_strings; 547 548 /** module stack */ 549 struct module_stack* modstack; 550 #ifdef USE_CACHEDB 551 /** the cachedb enabled value, copied and stored here. */ 552 int cachedb_enabled; 553 #endif 554 /* Make every mesh state unique, do not aggregate mesh states. */ 555 int unique_mesh; 556 }; 557 558 /** 559 * External visible states of the module state machine 560 * Modules may also have an internal state. 561 * Modules are supposed to run to completion or until blocked. 562 */ 563 enum module_ext_state { 564 /** initial state - new query */ 565 module_state_initial = 0, 566 /** waiting for reply to outgoing network query */ 567 module_wait_reply, 568 /** module is waiting for another module */ 569 module_wait_module, 570 /** module is waiting for another module; that other is restarted */ 571 module_restart_next, 572 /** module is waiting for sub-query */ 573 module_wait_subquery, 574 /** module could not finish the query */ 575 module_error, 576 /** module is finished with query */ 577 module_finished 578 }; 579 580 /** 581 * Events that happen to modules, that start or wakeup modules. 582 */ 583 enum module_ev { 584 /** new query */ 585 module_event_new = 0, 586 /** query passed by other module */ 587 module_event_pass, 588 /** reply inbound from server */ 589 module_event_reply, 590 /** no reply, timeout or other error */ 591 module_event_noreply, 592 /** reply is there, but capitalisation check failed */ 593 module_event_capsfail, 594 /** next module is done, and its reply is awaiting you */ 595 module_event_moddone, 596 /** error */ 597 module_event_error 598 }; 599 600 /** 601 * Linked list of sockaddrs 602 * May be allocated such that only 'len' bytes of addr exist for the structure. 603 */ 604 struct sock_list { 605 /** next in list */ 606 struct sock_list* next; 607 /** length of addr */ 608 socklen_t len; 609 /** sockaddr */ 610 struct sockaddr_storage addr; 611 }; 612 613 struct respip_action_info; 614 615 /** 616 * Struct to hold relevant data for serve expired 617 */ 618 struct serve_expired_data { 619 struct comm_timer* timer; 620 serve_expired_lookup_func_type* get_cached_answer; 621 }; 622 623 /** 624 * Module state, per query. 625 */ 626 struct module_qstate { 627 /** which query is being answered: name, type, class */ 628 struct query_info qinfo; 629 /** flags uint16 from query */ 630 uint16_t query_flags; 631 /** if this is a (stub or root) priming query (with hints) */ 632 int is_priming; 633 /** if this is a validation recursion query that does not get 634 * validation itself */ 635 int is_valrec; 636 #ifdef CLIENT_SUBNET 637 /** the client network address is needed for the client-subnet option 638 * when prefetching, but we can't use reply_list in mesh_info, because 639 * we don't want to send a reply for the internal query. */ 640 struct sockaddr_storage client_addr; 641 #endif 642 643 /** comm_reply contains server replies */ 644 struct comm_reply* reply; 645 /** the reply message, with message for client and calling module */ 646 struct dns_msg* return_msg; 647 /** the rcode, in case of error, instead of a reply message */ 648 int return_rcode; 649 /** origin of the reply (can be NULL from cache, list for cnames) */ 650 struct sock_list* reply_origin; 651 /** IP blacklist for queries */ 652 struct sock_list* blacklist; 653 /** region for this query. Cleared when query process finishes. */ 654 struct regional* region; 655 /** failure reason information if val-log-level is high */ 656 struct errinf_strlist* errinf; 657 /** which module is executing */ 658 int curmod; 659 /** module states */ 660 enum module_ext_state ext_state[MAX_MODULE]; 661 /** module specific data for query. indexed by module id. */ 662 void* minfo[MAX_MODULE]; 663 /** environment for this query */ 664 struct module_env* env; 665 /** mesh related information for this query */ 666 struct mesh_state* mesh_info; 667 /** how many seconds before expiry is this prefetched (0 if not) */ 668 time_t prefetch_leeway; 669 /** serve expired data */ 670 struct serve_expired_data* serve_expired_data; 671 672 /** incoming edns options from the front end */ 673 struct edns_option* edns_opts_front_in; 674 /** outgoing edns options to the back end */ 675 struct edns_option* edns_opts_back_out; 676 /** incoming edns options from the back end */ 677 struct edns_option* edns_opts_back_in; 678 /** outgoing edns options to the front end */ 679 struct edns_option* edns_opts_front_out; 680 /** whether modules should answer from the cache */ 681 int no_cache_lookup; 682 /** whether modules should store answer in the cache */ 683 int no_cache_store; 684 /** whether to refetch a fresh answer on finishing this state*/ 685 int need_refetch; 686 /** whether the query (or a subquery) was ratelimited */ 687 int was_ratelimited; 688 /** time when query was started. This is when the qstate is created. 689 * This is used so that type NS data cannot be overwritten by them 690 * expiring while the lookup is in progress, using data fetched from 691 * those servers. By comparing expiry time with qstarttime for type NS. 692 */ 693 time_t qstarttime; 694 /** whether a message from cachedb will be used for the reply */ 695 int is_cachedb_answer; 696 697 /** 698 * Attributes of clients that share the qstate that may affect IP-based 699 * actions. 700 */ 701 struct respip_client_info* client_info; 702 703 /** Extended result of response-ip action processing, mainly 704 * for logging purposes. */ 705 struct respip_action_info* respip_action_info; 706 /** if the query has been modified by rpz processing. */ 707 int rpz_applied; 708 /** if the query is rpz passthru, no further rpz processing for it */ 709 int rpz_passthru; 710 /* Flag tcp required. */ 711 int tcp_required; 712 713 /** whether the reply should be dropped */ 714 int is_drop; 715 }; 716 717 /** 718 * Module functionality block 719 */ 720 struct module_func_block { 721 /** text string name of module */ 722 const char* name; 723 724 /** 725 * Set up the module for start. This is called only once at startup. 726 * Privileged operations like opening device files may be done here. 727 * The function ptr can be NULL, if it is not used. 728 * @param env: module environment. 729 * @param id: module id number. 730 * return: 0 on error 731 */ 732 int (*startup)(struct module_env* env, int id); 733 734 /** 735 * Close down the module for stop. This is called only once before 736 * shutdown to free resources allocated during startup(). 737 * Closing privileged ports or files must be done here. 738 * The function ptr can be NULL, if it is not used. 739 * @param env: module environment. 740 * @param id: module id number. 741 */ 742 void (*destartup)(struct module_env* env, int id); 743 744 /** 745 * Initialise the module. Called when restarting or reloading the 746 * daemon. 747 * This is the place to apply settings from the config file. 748 * @param env: module environment. 749 * @param id: module id number. 750 * return: 0 on error 751 */ 752 int (*init)(struct module_env* env, int id); 753 754 /** 755 * Deinitialise the module, undo stuff done during init(). 756 * Called before reloading the daemon. 757 * @param env: module environment. 758 * @param id: module id number. 759 */ 760 void (*deinit)(struct module_env* env, int id); 761 762 /** 763 * accept a new query, or work further on existing query. 764 * Changes the qstate->ext_state to be correct on exit. 765 * @param ev: event that causes the module state machine to 766 * (re-)activate. 767 * @param qstate: the query state. 768 * Note that this method is not allowed to change the 769 * query state 'identity', that is query info, qflags, 770 * and priming status. 771 * Attach a subquery to get results to a different query. 772 * @param id: module id number that operate() is called on. 773 * @param outbound: if not NULL this event is due to the reply/timeout 774 * or error on this outbound query. 775 * @return: if at exit the ext_state is: 776 * o wait_module: next module is started. (with pass event). 777 * o error or finished: previous module is resumed. 778 * o otherwise it waits until that event happens (assumes 779 * the service routine to make subrequest or send message 780 * have been called. 781 */ 782 void (*operate)(struct module_qstate* qstate, enum module_ev event, 783 int id, struct outbound_entry* outbound); 784 785 /** 786 * inform super querystate about the results from this subquerystate. 787 * Is called when the querystate is finished. The method invoked is 788 * the one from the current module active in the super querystate. 789 * @param qstate: the query state that is finished. 790 * Examine return_rcode and return_reply in the qstate. 791 * @param id: module id for this module. 792 * This coincides with the current module for the super qstate. 793 * @param super: the super querystate that needs to be informed. 794 */ 795 void (*inform_super)(struct module_qstate* qstate, int id, 796 struct module_qstate* super); 797 798 /** 799 * clear module specific data 800 */ 801 void (*clear)(struct module_qstate* qstate, int id); 802 803 /** 804 * How much memory is the module specific data using. 805 * @param env: module environment. 806 * @param id: the module id. 807 * @return the number of bytes that are alloced. 808 */ 809 size_t (*get_mem)(struct module_env* env, int id); 810 }; 811 812 /** 813 * Debug utility: module external qstate to string 814 * @param s: the state value. 815 * @return descriptive string. 816 */ 817 const char* strextstate(enum module_ext_state s); 818 819 /** 820 * Debug utility: module event to string 821 * @param e: the module event value. 822 * @return descriptive string. 823 */ 824 const char* strmodulevent(enum module_ev e); 825 826 /** 827 * Append text to the error info for validation. 828 * @param qstate: query state. 829 * @param str: copied into query region and appended. 830 * Failures to allocate are logged. 831 */ 832 void errinf(struct module_qstate* qstate, const char* str); 833 void errinf_ede(struct module_qstate* qstate, const char* str, 834 sldns_ede_code reason_bogus); 835 836 /** 837 * Append text to error info: from 1.2.3.4 838 * @param qstate: query state. 839 * @param origin: sock list with origin of trouble. 840 * Every element added. 841 * If NULL: nothing is added. 842 * if 0len element: 'from cache' is added. 843 */ 844 void errinf_origin(struct module_qstate* qstate, struct sock_list *origin); 845 846 /** 847 * Append text to error info: for RRset name type class 848 * @param qstate: query state. 849 * @param rr: rrset_key. 850 */ 851 void errinf_rrset(struct module_qstate* qstate, struct ub_packed_rrset_key *rr); 852 853 /** 854 * Append text to error info: str dname 855 * @param qstate: query state. 856 * @param str: explanation string 857 * @param dname: the dname. 858 */ 859 void errinf_dname(struct module_qstate* qstate, const char* str, 860 uint8_t* dname); 861 862 /** 863 * Create error info in string. For validation failures. 864 * @param qstate: query state. 865 * @param region: the region for the result or NULL for malloced result. 866 * @return string or NULL on malloc failure (already logged). 867 * This string is malloced if region is NULL and has to be freed by caller. 868 */ 869 char* errinf_to_str_bogus(struct module_qstate* qstate, struct regional* region); 870 871 /** 872 * Check the sldns_ede_code of the qstate->errinf. 873 * @param qstate: query state. 874 * @return the latest explicitly set sldns_ede_code or LDNS_EDE_NONE. 875 */ 876 sldns_ede_code errinf_to_reason_bogus(struct module_qstate* qstate); 877 878 /** 879 * Create error info in string. For other servfails. 880 * @param qstate: query state. 881 * @return string or NULL on malloc failure (already logged). 882 */ 883 char* errinf_to_str_servfail(struct module_qstate* qstate); 884 885 /** 886 * Create error info in string. For misc failures that are not servfail. 887 * @param qstate: query state. 888 * @return string or NULL on malloc failure (already logged). 889 */ 890 char* errinf_to_str_misc(struct module_qstate* qstate); 891 892 /** 893 * Initialize the edns known options by allocating the required space. 894 * @param env: the module environment. 895 * @return false on failure (no memory). 896 */ 897 int edns_known_options_init(struct module_env* env); 898 899 /** 900 * Free the allocated space for the known edns options. 901 * @param env: the module environment. 902 */ 903 void edns_known_options_delete(struct module_env* env); 904 905 /** 906 * Register a known edns option. Overwrite the flags if it is already 907 * registered. Used before creating workers to register known edns options. 908 * @param opt_code: the edns option code. 909 * @param bypass_cache_stage: whether the option interacts with the cache. 910 * @param no_aggregation: whether the option implies more specific 911 * aggregation. 912 * @param env: the module environment. 913 * @return true on success, false on failure (registering more options than 914 * allowed or trying to register after the environment is copied to the 915 * threads.) 916 */ 917 int edns_register_option(uint16_t opt_code, int bypass_cache_stage, 918 int no_aggregation, struct module_env* env); 919 920 /** 921 * Register an inplace callback function. 922 * @param cb: pointer to the callback function. 923 * @param type: inplace callback type. 924 * @param cbarg: argument for the callback function, or NULL. 925 * @param env: the module environment. 926 * @param id: module id. 927 * @return true on success, false on failure (out of memory or trying to 928 * register after the environment is copied to the threads.) 929 */ 930 int 931 inplace_cb_register(void* cb, enum inplace_cb_list_type type, void* cbarg, 932 struct module_env* env, int id); 933 934 /** 935 * Delete callback for specified type and module id. 936 * @param env: the module environment. 937 * @param type: inplace callback type. 938 * @param id: module id. 939 */ 940 void 941 inplace_cb_delete(struct module_env* env, enum inplace_cb_list_type type, 942 int id); 943 944 /** 945 * Delete all the inplace callback linked lists. 946 * @param env: the module environment. 947 */ 948 void inplace_cb_lists_delete(struct module_env* env); 949 950 /** 951 * Check if an edns option is known. 952 * @param opt_code: the edns option code. 953 * @param env: the module environment. 954 * @return pointer to registered option if the edns option is known, 955 * NULL otherwise. 956 */ 957 struct edns_known_option* edns_option_is_known(uint16_t opt_code, 958 struct module_env* env); 959 960 /** 961 * Check if an edns option needs to bypass the reply from cache stage. 962 * @param list: the edns options. 963 * @param env: the module environment. 964 * @return true if an edns option needs to bypass the cache stage, 965 * false otherwise. 966 */ 967 int edns_bypass_cache_stage(struct edns_option* list, 968 struct module_env* env); 969 970 /** 971 * Check if an unique mesh state is required. Might be triggered by EDNS option 972 * or set for the complete env. 973 * @param list: the edns options. 974 * @param env: the module environment. 975 * @return true if an edns option needs a unique mesh state, 976 * false otherwise. 977 */ 978 int unique_mesh_state(struct edns_option* list, struct module_env* env); 979 980 /** 981 * Log the known edns options. 982 * @param level: the desired verbosity level. 983 * @param env: the module environment. 984 */ 985 void log_edns_known_options(enum verbosity_value level, 986 struct module_env* env); 987 988 /** 989 * Copy state that may have happened in the subquery and is always relevant to 990 * the super. 991 * @param qstate: query state that finished. 992 * @param id: module id. 993 * @param super: the qstate to inform. 994 */ 995 void copy_state_to_super(struct module_qstate* qstate, int id, 996 struct module_qstate* super); 997 998 #endif /* UTIL_MODULE_H */ 999