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