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 module_qstate; 170 struct ub_randstate; 171 struct mesh_area; 172 struct mesh_state; 173 struct val_anchors; 174 struct val_neg_cache; 175 struct iter_forwards; 176 struct iter_hints; 177 struct respip_set; 178 struct respip_client_info; 179 struct respip_addr_info; 180 181 /** Maximum number of modules in operation */ 182 #define MAX_MODULE 16 183 184 /** Maximum number of known edns options */ 185 #define MAX_KNOWN_EDNS_OPTS 256 186 187 enum inplace_cb_list_type { 188 /* Inplace callbacks for when a resolved reply is ready to be sent to the 189 * front.*/ 190 inplace_cb_reply = 0, 191 /* Inplace callbacks for when a reply is given from the cache. */ 192 inplace_cb_reply_cache, 193 /* Inplace callbacks for when a reply is given with local data 194 * (or Chaos reply). */ 195 inplace_cb_reply_local, 196 /* Inplace callbacks for when the reply is servfail. */ 197 inplace_cb_reply_servfail, 198 /* Inplace callbacks for when a query is ready to be sent to the back.*/ 199 inplace_cb_query, 200 /* Inplace callback for when a reply is received from the back. */ 201 inplace_cb_query_response, 202 /* Inplace callback for when EDNS is parsed on a reply received from the 203 * back. */ 204 inplace_cb_edns_back_parsed, 205 /* Total number of types. Used for array initialization. 206 * Should always be last. */ 207 inplace_cb_types_total 208 }; 209 210 211 /** Known edns option. Can be populated during modules' init. */ 212 struct edns_known_option { 213 /** type of this edns option */ 214 uint16_t opt_code; 215 /** whether the option needs to bypass the cache stage */ 216 int bypass_cache_stage; 217 /** whether the option needs mesh aggregation */ 218 int no_aggregation; 219 }; 220 221 /** 222 * Inplace callback list of registered routines to be called. 223 */ 224 struct inplace_cb { 225 /** next in list */ 226 struct inplace_cb* next; 227 /** Inplace callback routine */ 228 void* cb; 229 void* cb_arg; 230 /** module id */ 231 int id; 232 }; 233 234 /** 235 * Inplace callback function called before replying. 236 * Called as func(edns, qstate, opt_list_out, qinfo, reply_info, rcode, 237 * region, python_callback) 238 * Where: 239 * qinfo: the query info. 240 * qstate: the module state. NULL when calling before the query reaches the 241 * mesh states. 242 * rep: reply_info. Could be NULL. 243 * rcode: the return code. 244 * edns: the edns_data of the reply. When qstate is NULL, it is also used as 245 * the edns input. 246 * opt_list_out: the edns options list for the reply. 247 * region: region to store data. 248 * python_callback: only used for registering a python callback function. 249 */ 250 typedef int inplace_cb_reply_func_type(struct query_info* qinfo, 251 struct module_qstate* qstate, struct reply_info* rep, int rcode, 252 struct edns_data* edns, struct edns_option** opt_list_out, 253 struct regional* region, int id, void* callback); 254 255 /** 256 * Inplace callback function called before sending the query to a nameserver. 257 * Called as func(qinfo, flags, qstate, addr, addrlen, zone, zonelen, region, 258 * python_callback) 259 * Where: 260 * qinfo: query info. 261 * flags: flags of the query. 262 * qstate: query state. 263 * addr: to which server to send the query. 264 * addrlen: length of addr. 265 * zone: name of the zone of the delegation point. wireformat dname. 266 * This is the delegation point name for which the server is deemed 267 * authoritative. 268 * zonelen: length of zone. 269 * region: region to store data. 270 * python_callback: only used for registering a python callback function. 271 */ 272 typedef int inplace_cb_query_func_type(struct query_info* qinfo, uint16_t flags, 273 struct module_qstate* qstate, struct sockaddr_storage* addr, 274 socklen_t addrlen, uint8_t* zone, size_t zonelen, struct regional* region, 275 int id, void* callback); 276 277 /** 278 * Inplace callback function called after parsing edns on query reply. 279 * Called as func(qstate, cb_args) 280 * Where: 281 * qstate: the query state 282 * id: module id 283 * cb_args: argument passed when registering callback. 284 */ 285 typedef int inplace_cb_edns_back_parsed_func_type(struct module_qstate* qstate, 286 int id, void* cb_args); 287 288 /** 289 * Inplace callback function called after parsing query response. 290 * Called as func(qstate, id, cb_args) 291 * Where: 292 * qstate: the query state 293 * response: query response 294 * id: module id 295 * cb_args: argument passed when registering callback. 296 */ 297 typedef int inplace_cb_query_response_func_type(struct module_qstate* qstate, 298 struct dns_msg* response, int id, void* cb_args); 299 300 /** 301 * Module environment. 302 * Services and data provided to the module. 303 */ 304 struct module_env { 305 /* --- data --- */ 306 /** config file with config options */ 307 struct config_file* cfg; 308 /** shared message cache */ 309 struct slabhash* msg_cache; 310 /** shared rrset cache */ 311 struct rrset_cache* rrset_cache; 312 /** shared infrastructure cache (edns, lameness) */ 313 struct infra_cache* infra_cache; 314 /** shared key cache */ 315 struct key_cache* key_cache; 316 317 /* --- services --- */ 318 /** 319 * Send serviced DNS query to server. UDP/TCP and EDNS is handled. 320 * operate() should return with wait_reply. Later on a callback 321 * will cause operate() to be called with event timeout or reply. 322 * The time until a timeout is calculated from roundtrip timing, 323 * several UDP retries are attempted. 324 * @param qinfo: query info. 325 * @param flags: host order flags word, with opcode and CD bit. 326 * @param dnssec: if set, EDNS record will have bits set. 327 * If EDNS_DO bit is set, DO bit is set in EDNS records. 328 * If BIT_CD is set, CD bit is set in queries with EDNS records. 329 * @param want_dnssec: if set, the validator wants DNSSEC. Without 330 * EDNS, the answer is likely to be useless for this domain. 331 * @param nocaps: do not use caps_for_id, use the qname as given. 332 * (ignored if caps_for_id is disabled). 333 * @param addr: where to. 334 * @param addrlen: length of addr. 335 * @param zone: delegation point name. 336 * @param zonelen: length of zone name. 337 * @param ssl_upstream: use SSL for upstream queries. 338 * @param q: wich query state to reactivate upon return. 339 * @return: false on failure (memory or socket related). no query was 340 * sent. Or returns an outbound entry with qsent and qstate set. 341 * This outbound_entry will be used on later module invocations 342 * that involve this query (timeout, error or reply). 343 */ 344 struct outbound_entry* (*send_query)(struct query_info* qinfo, 345 uint16_t flags, int dnssec, int want_dnssec, int nocaps, 346 struct sockaddr_storage* addr, socklen_t addrlen, 347 uint8_t* zone, size_t zonelen, int ssl_upstream, 348 struct module_qstate* q); 349 350 /** 351 * Detach-subqueries. 352 * Remove all sub-query references from this query state. 353 * Keeps super-references of those sub-queries correct. 354 * Updates stat items in mesh_area structure. 355 * @param qstate: used to find mesh state. 356 */ 357 void (*detach_subs)(struct module_qstate* qstate); 358 359 /** 360 * Attach subquery. 361 * Creates it if it does not exist already. 362 * Keeps sub and super references correct. 363 * Updates stat items in mesh_area structure. 364 * Pass if it is priming query or not. 365 * return: 366 * o if error (malloc) happened. 367 * o need to initialise the new state (module init; it is a new state). 368 * so that the next run of the query with this module is successful. 369 * o no init needed, attachment successful. 370 * 371 * @param qstate: the state to find mesh state, and that wants to 372 * receive the results from the new subquery. 373 * @param qinfo: what to query for (copied). 374 * @param qflags: what flags to use (RD, CD flag or not). 375 * @param prime: if it is a (stub) priming query. 376 * @param valrec: validation lookup recursion, does not need validation 377 * @param newq: If the new subquery needs initialisation, it is 378 * returned, otherwise NULL is returned. 379 * @return: false on error, true if success (and init may be needed). 380 */ 381 int (*attach_sub)(struct module_qstate* qstate, 382 struct query_info* qinfo, uint16_t qflags, int prime, 383 int valrec, struct module_qstate** newq); 384 385 /** 386 * Add detached query. 387 * Creates it if it does not exist already. 388 * Does not make super/sub references. 389 * Performs a cycle detection - for double check - and fails if there is 390 * one. 391 * Updates stat items in mesh_area structure. 392 * Pass if it is priming query or not. 393 * return: 394 * o if error (malloc) happened. 395 * o need to initialise the new state (module init; it is a new state). 396 * so that the next run of the query with this module is successful. 397 * o no init needed, attachment successful. 398 * o added subquery, created if it did not exist already. 399 * 400 * @param qstate: the state to find mesh state, and that wants to receive 401 * the results from the new subquery. 402 * @param qinfo: what to query for (copied). 403 * @param qflags: what flags to use (RD / CD flag or not). 404 * @param prime: if it is a (stub) priming query. 405 * @param valrec: if it is a validation recursion query (lookup of key, DS). 406 * @param newq: If the new subquery needs initialisation, it is returned, 407 * otherwise NULL is returned. 408 * @param sub: The added mesh state, created if it did not exist already. 409 * @return: false on error, true if success (and init may be needed). 410 */ 411 int (*add_sub)(struct module_qstate* qstate, 412 struct query_info* qinfo, uint16_t qflags, int prime, 413 int valrec, struct module_qstate** newq, 414 struct mesh_state** sub); 415 416 /** 417 * Kill newly attached sub. If attach_sub returns newq for 418 * initialisation, but that fails, then this routine will cleanup and 419 * delete the fresly created sub. 420 * @param newq: the new subquery that is no longer needed. 421 * It is removed. 422 */ 423 void (*kill_sub)(struct module_qstate* newq); 424 425 /** 426 * Detect if adding a dependency for qstate on name,type,class will 427 * create a dependency cycle. 428 * @param qstate: given mesh querystate. 429 * @param qinfo: query info for dependency. 430 * @param flags: query flags of dependency, RD/CD flags. 431 * @param prime: if dependency is a priming query or not. 432 * @param valrec: validation lookup recursion, does not need validation 433 * @return true if the name,type,class exists and the given 434 * qstate mesh exists as a dependency of that name. Thus 435 * if qstate becomes dependent on name,type,class then a 436 * cycle is created. 437 */ 438 int (*detect_cycle)(struct module_qstate* qstate, 439 struct query_info* qinfo, uint16_t flags, int prime, 440 int valrec); 441 442 /** region for temporary usage. May be cleared after operate() call. */ 443 struct regional* scratch; 444 /** buffer for temporary usage. May be cleared after operate() call. */ 445 struct sldns_buffer* scratch_buffer; 446 /** internal data for daemon - worker thread. */ 447 struct worker* worker; 448 /** mesh area with query state dependencies */ 449 struct mesh_area* mesh; 450 /** allocation service */ 451 struct alloc_cache* alloc; 452 /** random table to generate random numbers */ 453 struct ub_randstate* rnd; 454 /** time in seconds, converted to integer */ 455 time_t* now; 456 /** time in microseconds. Relatively recent. */ 457 struct timeval* now_tv; 458 /** is validation required for messages, controls client-facing 459 * validation status (AD bits) and servfails */ 460 int need_to_validate; 461 /** trusted key storage; these are the configured keys, if not NULL, 462 * otherwise configured by validator. These are the trust anchors, 463 * and are not primed and ready for validation, but on the bright 464 * side, they are read only memory, thus no locks and fast. */ 465 struct val_anchors* anchors; 466 /** negative cache, configured by the validator. if not NULL, 467 * contains NSEC record lookup trees. */ 468 struct val_neg_cache* neg_cache; 469 /** the 5011-probe timer (if any) */ 470 struct comm_timer* probe_timer; 471 /** Mapping of forwarding zones to targets. 472 * iterator forwarder information. per-thread, created by worker */ 473 struct iter_forwards* fwds; 474 /** 475 * iterator forwarder information. per-thread, created by worker. 476 * The hints -- these aren't stored in the cache because they don't 477 * expire. The hints are always used to "prime" the cache. Note 478 * that both root hints and stub zone "hints" are stored in this 479 * data structure. 480 */ 481 struct iter_hints* hints; 482 /** module specific data. indexed by module id. */ 483 void* modinfo[MAX_MODULE]; 484 485 /* Shared linked list of inplace callback functions */ 486 struct inplace_cb* inplace_cb_lists[inplace_cb_types_total]; 487 488 /** 489 * Shared array of known edns options (size MAX_KNOWN_EDNS_OPTS). 490 * Filled by edns literate modules during init. 491 */ 492 struct edns_known_option* edns_known_options; 493 /* Number of known edns options */ 494 size_t edns_known_options_num; 495 496 /* Make every mesh state unique, do not aggregate mesh states. */ 497 int unique_mesh; 498 }; 499 500 /** 501 * External visible states of the module state machine 502 * Modules may also have an internal state. 503 * Modules are supposed to run to completion or until blocked. 504 */ 505 enum module_ext_state { 506 /** initial state - new query */ 507 module_state_initial = 0, 508 /** waiting for reply to outgoing network query */ 509 module_wait_reply, 510 /** module is waiting for another module */ 511 module_wait_module, 512 /** module is waiting for another module; that other is restarted */ 513 module_restart_next, 514 /** module is waiting for sub-query */ 515 module_wait_subquery, 516 /** module could not finish the query */ 517 module_error, 518 /** module is finished with query */ 519 module_finished 520 }; 521 522 /** 523 * Events that happen to modules, that start or wakeup modules. 524 */ 525 enum module_ev { 526 /** new query */ 527 module_event_new = 0, 528 /** query passed by other module */ 529 module_event_pass, 530 /** reply inbound from server */ 531 module_event_reply, 532 /** no reply, timeout or other error */ 533 module_event_noreply, 534 /** reply is there, but capitalisation check failed */ 535 module_event_capsfail, 536 /** next module is done, and its reply is awaiting you */ 537 module_event_moddone, 538 /** error */ 539 module_event_error 540 }; 541 542 /** 543 * Linked list of sockaddrs 544 * May be allocated such that only 'len' bytes of addr exist for the structure. 545 */ 546 struct sock_list { 547 /** next in list */ 548 struct sock_list* next; 549 /** length of addr */ 550 socklen_t len; 551 /** sockaddr */ 552 struct sockaddr_storage addr; 553 }; 554 555 struct respip_action_info; 556 557 /** 558 * Module state, per query. 559 */ 560 struct module_qstate { 561 /** which query is being answered: name, type, class */ 562 struct query_info qinfo; 563 /** flags uint16 from query */ 564 uint16_t query_flags; 565 /** if this is a (stub or root) priming query (with hints) */ 566 int is_priming; 567 /** if this is a validation recursion query that does not get 568 * validation itself */ 569 int is_valrec; 570 571 /** comm_reply contains server replies */ 572 struct comm_reply* reply; 573 /** the reply message, with message for client and calling module */ 574 struct dns_msg* return_msg; 575 /** the rcode, in case of error, instead of a reply message */ 576 int return_rcode; 577 /** origin of the reply (can be NULL from cache, list for cnames) */ 578 struct sock_list* reply_origin; 579 /** IP blacklist for queries */ 580 struct sock_list* blacklist; 581 /** region for this query. Cleared when query process finishes. */ 582 struct regional* region; 583 /** failure reason information if val-log-level is high */ 584 struct config_strlist* errinf; 585 586 /** which module is executing */ 587 int curmod; 588 /** module states */ 589 enum module_ext_state ext_state[MAX_MODULE]; 590 /** module specific data for query. indexed by module id. */ 591 void* minfo[MAX_MODULE]; 592 /** environment for this query */ 593 struct module_env* env; 594 /** mesh related information for this query */ 595 struct mesh_state* mesh_info; 596 /** how many seconds before expiry is this prefetched (0 if not) */ 597 time_t prefetch_leeway; 598 599 /** incoming edns options from the front end */ 600 struct edns_option* edns_opts_front_in; 601 /** outgoing edns options to the back end */ 602 struct edns_option* edns_opts_back_out; 603 /** incoming edns options from the back end */ 604 struct edns_option* edns_opts_back_in; 605 /** outgoing edns options to the front end */ 606 struct edns_option* edns_opts_front_out; 607 /** whether modules should answer from the cache */ 608 int no_cache_lookup; 609 /** whether modules should store answer in the cache */ 610 int no_cache_store; 611 612 /** 613 * Attributes of clients that share the qstate that may affect IP-based 614 * actions. 615 */ 616 struct respip_client_info* client_info; 617 618 /** Extended result of response-ip action processing, mainly 619 * for logging purposes. */ 620 struct respip_action_info* respip_action_info; 621 622 /** whether the reply should be dropped */ 623 int is_drop; 624 }; 625 626 /** 627 * Module functionality block 628 */ 629 struct module_func_block { 630 /** text string name of module */ 631 const char* name; 632 633 /** 634 * init the module. Called once for the global state. 635 * This is the place to apply settings from the config file. 636 * @param env: module environment. 637 * @param id: module id number. 638 * return: 0 on error 639 */ 640 int (*init)(struct module_env* env, int id); 641 642 /** 643 * de-init, delete, the module. Called once for the global state. 644 * @param env: module environment. 645 * @param id: module id number. 646 */ 647 void (*deinit)(struct module_env* env, int id); 648 649 /** 650 * accept a new query, or work further on existing query. 651 * Changes the qstate->ext_state to be correct on exit. 652 * @param ev: event that causes the module state machine to 653 * (re-)activate. 654 * @param qstate: the query state. 655 * Note that this method is not allowed to change the 656 * query state 'identity', that is query info, qflags, 657 * and priming status. 658 * Attach a subquery to get results to a different query. 659 * @param id: module id number that operate() is called on. 660 * @param outbound: if not NULL this event is due to the reply/timeout 661 * or error on this outbound query. 662 * @return: if at exit the ext_state is: 663 * o wait_module: next module is started. (with pass event). 664 * o error or finished: previous module is resumed. 665 * o otherwise it waits until that event happens (assumes 666 * the service routine to make subrequest or send message 667 * have been called. 668 */ 669 void (*operate)(struct module_qstate* qstate, enum module_ev event, 670 int id, struct outbound_entry* outbound); 671 672 /** 673 * inform super querystate about the results from this subquerystate. 674 * Is called when the querystate is finished. The method invoked is 675 * the one from the current module active in the super querystate. 676 * @param qstate: the query state that is finished. 677 * Examine return_rcode and return_reply in the qstate. 678 * @param id: module id for this module. 679 * This coincides with the current module for the super qstate. 680 * @param super: the super querystate that needs to be informed. 681 */ 682 void (*inform_super)(struct module_qstate* qstate, int id, 683 struct module_qstate* super); 684 685 /** 686 * clear module specific data 687 */ 688 void (*clear)(struct module_qstate* qstate, int id); 689 690 /** 691 * How much memory is the module specific data using. 692 * @param env: module environment. 693 * @param id: the module id. 694 * @return the number of bytes that are alloced. 695 */ 696 size_t (*get_mem)(struct module_env* env, int id); 697 }; 698 699 /** 700 * Debug utility: module external qstate to string 701 * @param s: the state value. 702 * @return descriptive string. 703 */ 704 const char* strextstate(enum module_ext_state s); 705 706 /** 707 * Debug utility: module event to string 708 * @param e: the module event value. 709 * @return descriptive string. 710 */ 711 const char* strmodulevent(enum module_ev e); 712 713 /** 714 * Initialize the edns known options by allocating the required space. 715 * @param env: the module environment. 716 * @return false on failure (no memory). 717 */ 718 int edns_known_options_init(struct module_env* env); 719 720 /** 721 * Free the allocated space for the known edns options. 722 * @param env: the module environment. 723 */ 724 void edns_known_options_delete(struct module_env* env); 725 726 /** 727 * Register a known edns option. Overwrite the flags if it is already 728 * registered. Used before creating workers to register known edns options. 729 * @param opt_code: the edns option code. 730 * @param bypass_cache_stage: whether the option interacts with the cache. 731 * @param no_aggregation: whether the option implies more specific 732 * aggregation. 733 * @param env: the module environment. 734 * @return true on success, false on failure (registering more options than 735 * allowed or trying to register after the environment is copied to the 736 * threads.) 737 */ 738 int edns_register_option(uint16_t opt_code, int bypass_cache_stage, 739 int no_aggregation, struct module_env* env); 740 741 /** 742 * Register an inplace callback function. 743 * @param cb: pointer to the callback function. 744 * @param type: inplace callback type. 745 * @param cbarg: argument for the callback function, or NULL. 746 * @param env: the module environment. 747 * @param id: module id. 748 * @return true on success, false on failure (out of memory or trying to 749 * register after the environment is copied to the threads.) 750 */ 751 int 752 inplace_cb_register(void* cb, enum inplace_cb_list_type type, void* cbarg, 753 struct module_env* env, int id); 754 755 /** 756 * Delete callback for specified type and module id. 757 * @param env: the module environment. 758 * @param type: inplace callback type. 759 * @param id: module id. 760 */ 761 void 762 inplace_cb_delete(struct module_env* env, enum inplace_cb_list_type type, 763 int id); 764 765 /** 766 * Delete all the inplace callback linked lists. 767 * @param env: the module environment. 768 */ 769 void inplace_cb_lists_delete(struct module_env* env); 770 771 /** 772 * Check if an edns option is known. 773 * @param opt_code: the edns option code. 774 * @param env: the module environment. 775 * @return pointer to registered option if the edns option is known, 776 * NULL otherwise. 777 */ 778 struct edns_known_option* edns_option_is_known(uint16_t opt_code, 779 struct module_env* env); 780 781 /** 782 * Check if an edns option needs to bypass the reply from cache stage. 783 * @param list: the edns options. 784 * @param env: the module environment. 785 * @return true if an edns option needs to bypass the cache stage, 786 * false otherwise. 787 */ 788 int edns_bypass_cache_stage(struct edns_option* list, 789 struct module_env* env); 790 791 /** 792 * Check if an unique mesh state is required. Might be triggered by EDNS option 793 * or set for the complete env. 794 * @param list: the edns options. 795 * @param env: the module environment. 796 * @return true if an edns option needs a unique mesh state, 797 * false otherwise. 798 */ 799 int unique_mesh_state(struct edns_option* list, struct module_env* env); 800 801 /** 802 * Log the known edns options. 803 * @param level: the desired verbosity level. 804 * @param env: the module environment. 805 */ 806 void log_edns_known_options(enum verbosity_value level, 807 struct module_env* env); 808 809 #endif /* UTIL_MODULE_H */ 810