1 /* 2 * services/mesh.h - deal with mesh of query states and handle events for that. 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 functions to assist in dealing with a mesh of 40 * query states. This mesh is supposed to be thread-specific. 41 * It consists of query states (per qname, qtype, qclass) and connections 42 * between query states and the super and subquery states, and replies to 43 * send back to clients. 44 */ 45 46 #ifndef SERVICES_MESH_H 47 #define SERVICES_MESH_H 48 49 #include "util/rbtree.h" 50 #include "util/netevent.h" 51 #include "util/data/msgparse.h" 52 #include "util/module.h" 53 #include "services/modstack.h" 54 #include "services/rpz.h" 55 #include "libunbound/unbound.h" 56 struct sldns_buffer; 57 struct mesh_state; 58 struct mesh_reply; 59 struct mesh_cb; 60 struct query_info; 61 struct reply_info; 62 struct outbound_entry; 63 struct timehist; 64 struct respip_client_info; 65 66 /** 67 * Maximum number of mesh state activations. Any more is likely an 68 * infinite loop in the module. It is then terminated. 69 */ 70 #define MESH_MAX_ACTIVATION 10000 71 72 /** 73 * Max number of references-to-references-to-references.. search size. 74 * Any more is treated like 'too large', and the creation of a new 75 * dependency is failed (so that no loops can be created). 76 */ 77 #define MESH_MAX_SUBSUB 1024 78 79 /** 80 * Mesh of query states 81 */ 82 struct mesh_area { 83 /** active module stack */ 84 struct module_stack mods; 85 /** environment for new states */ 86 struct module_env* env; 87 88 /** set of runnable queries (mesh_state.run_node) */ 89 rbtree_type run; 90 /** rbtree of all current queries (mesh_state.node)*/ 91 rbtree_type all; 92 93 /** count of the total number of mesh_reply entries */ 94 size_t num_reply_addrs; 95 /** count of the number of mesh_states that have mesh_replies 96 * Because a state can send results to multiple reply addresses, 97 * this number must be equal or lower than num_reply_addrs. */ 98 size_t num_reply_states; 99 /** number of mesh_states that have no mesh_replies, and also 100 * an empty set of super-states, thus are 'toplevel' or detached 101 * internal opportunistic queries */ 102 size_t num_detached_states; 103 /** number of reply states in the forever list */ 104 size_t num_forever_states; 105 106 /** max total number of reply states to have */ 107 size_t max_reply_states; 108 /** max forever number of reply states to have */ 109 size_t max_forever_states; 110 111 /** stats, cumulative number of reply states jostled out */ 112 size_t stats_jostled; 113 /** stats, cumulative number of incoming client msgs dropped */ 114 size_t stats_dropped; 115 /** stats, number of expired replies sent */ 116 size_t ans_expired; 117 /** stats, number of cached replies from cachedb */ 118 size_t ans_cachedb; 119 /** number of replies sent */ 120 size_t replies_sent; 121 /** sum of waiting times for the replies */ 122 struct timeval replies_sum_wait; 123 /** histogram of time values */ 124 struct timehist* histogram; 125 /** (extended stats) secure replies */ 126 size_t ans_secure; 127 /** (extended stats) bogus replies */ 128 size_t ans_bogus; 129 /** (extended stats) rcodes in replies */ 130 size_t ans_rcode[UB_STATS_RCODE_NUM]; 131 /** (extended stats) rcode nodata in replies */ 132 size_t ans_nodata; 133 /** (extended stats) type of applied RPZ action */ 134 size_t rpz_action[UB_STATS_RPZ_ACTION_NUM]; 135 136 /** backup of query if other operations recurse and need the 137 * network buffers */ 138 struct sldns_buffer* qbuf_bak; 139 140 /** double linked list of the run-to-completion query states. 141 * These are query states with a reply */ 142 struct mesh_state* forever_first; 143 /** last entry in run forever list */ 144 struct mesh_state* forever_last; 145 146 /** double linked list of the query states that can be jostled out 147 * by new queries if too old. These are query states with a reply */ 148 struct mesh_state* jostle_first; 149 /** last entry in jostle list - this is the entry that is newest */ 150 struct mesh_state* jostle_last; 151 /** timeout for jostling. if age is lower, it does not get jostled. */ 152 struct timeval jostle_max; 153 154 /** If we need to use response ip (value passed from daemon)*/ 155 int use_response_ip; 156 /** If we need to use RPZ (value passed from daemon) */ 157 int use_rpz; 158 }; 159 160 /** 161 * A mesh query state 162 * Unique per qname, qtype, qclass (from the qstate). 163 * And RD / CD flag; in case a client turns it off. 164 * And priming queries are different from ordinary queries (because of hints). 165 * 166 * The entire structure is allocated in a region, this region is the qstate 167 * region. All parts (rbtree nodes etc) are also allocated in the region. 168 */ 169 struct mesh_state { 170 /** node in mesh_area all tree, key is this struct. Must be first. */ 171 rbnode_type node; 172 /** node in mesh_area runnable tree, key is this struct */ 173 rbnode_type run_node; 174 /** the query state. Note that the qinfo and query_flags 175 * may not change. */ 176 struct module_qstate s; 177 /** the list of replies to clients for the results */ 178 struct mesh_reply* reply_list; 179 /** the list of callbacks for the results */ 180 struct mesh_cb* cb_list; 181 /** set of superstates (that want this state's result) 182 * contains struct mesh_state_ref* */ 183 rbtree_type super_set; 184 /** set of substates (that this state needs to continue) 185 * contains struct mesh_state_ref* */ 186 rbtree_type sub_set; 187 /** number of activations for the mesh state */ 188 size_t num_activated; 189 190 /** previous in linked list for reply states */ 191 struct mesh_state* prev; 192 /** next in linked list for reply states */ 193 struct mesh_state* next; 194 /** if this state is in the forever list, jostle list, or neither */ 195 enum mesh_list_select { mesh_no_list, mesh_forever_list, 196 mesh_jostle_list } list_select; 197 /** pointer to this state for uniqueness or NULL */ 198 struct mesh_state* unique; 199 200 /** true if replies have been sent out (at end for alignment) */ 201 uint8_t replies_sent; 202 }; 203 204 /** 205 * Rbtree reference to a mesh_state. 206 * Used in super_set and sub_set. 207 */ 208 struct mesh_state_ref { 209 /** node in rbtree for set, key is this structure */ 210 rbnode_type node; 211 /** the mesh state */ 212 struct mesh_state* s; 213 }; 214 215 /** 216 * Reply to a client 217 */ 218 struct mesh_reply { 219 /** next in reply list */ 220 struct mesh_reply* next; 221 /** the query reply destination, packet buffer and where to send. */ 222 struct comm_reply query_reply; 223 /** edns data from query */ 224 struct edns_data edns; 225 /** the time when request was entered */ 226 struct timeval start_time; 227 /** id of query, in network byteorder. */ 228 uint16_t qid; 229 /** flags of query, for reply flags */ 230 uint16_t qflags; 231 /** qname from this query. len same as mesh qinfo. */ 232 uint8_t* qname; 233 /** same as that in query_info. */ 234 struct local_rrset* local_alias; 235 /** send query to this http2 stream, if set */ 236 struct http2_stream* h2_stream; 237 }; 238 239 /** 240 * Mesh result callback func. 241 * called as func(cb_arg, rcode, buffer_with_reply, security, why_bogus, 242 * was_ratelimited); 243 */ 244 typedef void (*mesh_cb_func_type)(void* cb_arg, int rcode, struct sldns_buffer*, 245 enum sec_status, char* why_bogus, int was_ratelimited); 246 247 /** 248 * Callback to result routine 249 */ 250 struct mesh_cb { 251 /** next in list */ 252 struct mesh_cb* next; 253 /** edns data from query */ 254 struct edns_data edns; 255 /** id of query, in network byteorder. */ 256 uint16_t qid; 257 /** flags of query, for reply flags */ 258 uint16_t qflags; 259 /** buffer for reply */ 260 struct sldns_buffer* buf; 261 /** callback routine for results. if rcode != 0 buf has message. 262 * called as cb(cb_arg, rcode, buf, sec_state, why_bogus, was_ratelimited); 263 */ 264 mesh_cb_func_type cb; 265 /** user arg for callback */ 266 void* cb_arg; 267 }; 268 269 /* ------------------- Functions for worker -------------------- */ 270 271 /** 272 * Allocate mesh, to empty. 273 * @param stack: module stack to activate, copied (as readonly reference). 274 * @param env: environment for new queries. 275 * @return mesh: the new mesh or NULL on error. 276 */ 277 struct mesh_area* mesh_create(struct module_stack* stack, 278 struct module_env* env); 279 280 /** 281 * Delete mesh, and all query states and replies in it. 282 * @param mesh: the mesh to delete. 283 */ 284 void mesh_delete(struct mesh_area* mesh); 285 286 /** 287 * New query incoming from clients. Create new query state if needed, and 288 * add mesh_reply to it. Returns error to client on malloc failures. 289 * Will run the mesh area queries to process if a new query state is created. 290 * 291 * @param mesh: the mesh. 292 * @param qinfo: query from client. 293 * @param cinfo: additional information associated with the query client. 294 * 'cinfo' itself is ephemeral but data pointed to by its members 295 * can be assumed to be valid and unchanged until the query processing is 296 * completed. 297 * @param qflags: flags from client query. 298 * @param edns: edns data from client query. 299 * @param rep: where to reply to. 300 * @param qid: query id to reply with. 301 * @param rpz_passthru: if true, the rpz passthru was previously found and 302 * further rpz processing is stopped. 303 */ 304 void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo, 305 struct respip_client_info* cinfo, uint16_t qflags, 306 struct edns_data* edns, struct comm_reply* rep, uint16_t qid, 307 int rpz_passthru); 308 309 /** 310 * New query with callback. Create new query state if needed, and 311 * add mesh_cb to it. 312 * Will run the mesh area queries to process if a new query state is created. 313 * 314 * @param mesh: the mesh. 315 * @param qinfo: query from client. 316 * @param qflags: flags from client query. 317 * @param edns: edns data from client query. 318 * @param buf: buffer for reply contents. 319 * @param qid: query id to reply with. 320 * @param cb: callback function. 321 * @param cb_arg: callback user arg. 322 * @param rpz_passthru: if true, the rpz passthru was previously found and 323 * further rpz processing is stopped. 324 * @return 0 on error. 325 */ 326 int mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo, 327 uint16_t qflags, struct edns_data* edns, struct sldns_buffer* buf, 328 uint16_t qid, mesh_cb_func_type cb, void* cb_arg, int rpz_passthru); 329 330 /** 331 * New prefetch message. Create new query state if needed. 332 * Will run the mesh area queries to process if a new query state is created. 333 * 334 * @param mesh: the mesh. 335 * @param qinfo: query from client. 336 * @param qflags: flags from client query. 337 * @param leeway: TTL leeway what to expire earlier for this update. 338 * @param rpz_passthru: if true, the rpz passthru was previously found and 339 * further rpz processing is stopped. 340 * @param addr: sockaddr_storage for the client; to be used with subnet. 341 * @param opt_list: edns opt_list from the client; to be used when subnet is 342 * enabled. 343 */ 344 void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo, 345 uint16_t qflags, time_t leeway, int rpz_passthru, 346 struct sockaddr_storage* addr, struct edns_option* opt_list); 347 348 /** 349 * Handle new event from the wire. A serviced query has returned. 350 * The query state will be made runnable, and the mesh_area will process 351 * query states until processing is complete. 352 * 353 * @param mesh: the query mesh. 354 * @param e: outbound entry, with query state to run and reply pointer. 355 * @param reply: the comm point reply info. 356 * @param what: NETEVENT_* error code (if not 0, what is wrong, TIMEOUT). 357 */ 358 void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e, 359 struct comm_reply* reply, int what); 360 361 /* ------------------- Functions for module environment --------------- */ 362 363 /** 364 * Detach-subqueries. 365 * Remove all sub-query references from this query state. 366 * Keeps super-references of those sub-queries correct. 367 * Updates stat items in mesh_area structure. 368 * @param qstate: used to find mesh state. 369 */ 370 void mesh_detach_subs(struct module_qstate* qstate); 371 372 /** 373 * Attach subquery. 374 * Creates it if it does not exist already. 375 * Keeps sub and super references correct. 376 * Performs a cycle detection - for double check - and fails if there is one. 377 * Also fails if the sub-sub-references become too large. 378 * Updates stat items in mesh_area structure. 379 * Pass if it is priming query or not. 380 * return: 381 * o if error (malloc) happened. 382 * o need to initialise the new state (module init; it is a new state). 383 * so that the next run of the query with this module is successful. 384 * o no init needed, attachment successful. 385 * 386 * @param qstate: the state to find mesh state, and that wants to receive 387 * the results from the new subquery. 388 * @param qinfo: what to query for (copied). 389 * @param qflags: what flags to use (RD / CD flag or not). 390 * @param prime: if it is a (stub) priming query. 391 * @param valrec: if it is a validation recursion query (lookup of key, DS). 392 * @param newq: If the new subquery needs initialisation, it is returned, 393 * otherwise NULL is returned. 394 * @return: false on error, true if success (and init may be needed). 395 */ 396 int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo, 397 uint16_t qflags, int prime, int valrec, struct module_qstate** newq); 398 399 /** 400 * Add detached query. 401 * Creates it if it does not exist already. 402 * Does not make super/sub references. 403 * Performs a cycle detection - for double check - and fails if there is one. 404 * Updates stat items in mesh_area structure. 405 * Pass if it is priming query or not. 406 * return: 407 * o if error (malloc) happened. 408 * o need to initialise the new state (module init; it is a new state). 409 * so that the next run of the query with this module is successful. 410 * o no init needed, attachment successful. 411 * o added subquery, created if it did not exist already. 412 * 413 * @param qstate: the state to find mesh state, and that wants to receive 414 * the results from the new subquery. 415 * @param qinfo: what to query for (copied). 416 * @param qflags: what flags to use (RD / CD flag or not). 417 * @param prime: if it is a (stub) priming query. 418 * @param valrec: if it is a validation recursion query (lookup of key, DS). 419 * @param newq: If the new subquery needs initialisation, it is returned, 420 * otherwise NULL is returned. 421 * @param sub: The added mesh state, created if it did not exist already. 422 * @return: false on error, true if success (and init may be needed). 423 */ 424 int mesh_add_sub(struct module_qstate* qstate, struct query_info* qinfo, 425 uint16_t qflags, int prime, int valrec, struct module_qstate** newq, 426 struct mesh_state** sub); 427 428 /** 429 * Query state is done, send messages to reply entries. 430 * Encode messages using reply entry values and the querystate (with original 431 * qinfo), using given reply_info. 432 * Pass errcode != 0 if an error reply is needed. 433 * If no reply entries, nothing is done. 434 * Must be called before a module can module_finished or return module_error. 435 * The module must handle the super query states itself as well. 436 * 437 * @param mstate: mesh state that is done. return_rcode and return_msg 438 * are used for replies. 439 * return_rcode: if not 0 (NOERROR) an error is sent back (and 440 * return_msg is ignored). 441 * return_msg: reply to encode and send back to clients. 442 */ 443 void mesh_query_done(struct mesh_state* mstate); 444 445 /** 446 * Call inform_super for the super query states that are interested in the 447 * results from this query state. These can then be changed for error 448 * or results. 449 * Called when a module is module_finished or returns module_error. 450 * The super query states become runnable with event module_event_pass, 451 * it calls the current module for the super with the inform_super event. 452 * 453 * @param mesh: mesh area to add newly runnable modules to. 454 * @param mstate: the state that has results, used to find mesh state. 455 */ 456 void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate); 457 458 /** 459 * Delete mesh state, cleanup and also rbtrees and so on. 460 * Will detach from all super/subnodes. 461 * @param qstate: to remove. 462 */ 463 void mesh_state_delete(struct module_qstate* qstate); 464 465 /* ------------------- Functions for mesh -------------------- */ 466 467 /** 468 * Create and initialize a new mesh state and its query state 469 * Does not put the mesh state into rbtrees and so on. 470 * @param env: module environment to set. 471 * @param qinfo: query info that the mesh is for. 472 * @param cinfo: control info for the query client (can be NULL). 473 * @param qflags: flags for query (RD / CD flag). 474 * @param prime: if true, it is a priming query, set is_priming on mesh state. 475 * @param valrec: if true, it is a validation recursion query, and sets 476 * is_valrec on the mesh state. 477 * @return: new mesh state or NULL on allocation error. 478 */ 479 struct mesh_state* mesh_state_create(struct module_env* env, 480 struct query_info* qinfo, struct respip_client_info* cinfo, 481 uint16_t qflags, int prime, int valrec); 482 483 /** 484 * Make a mesh state unique. 485 * A unique mesh state uses it's unique member to point to itself. 486 * @param mstate: mesh state to check. 487 */ 488 void mesh_state_make_unique(struct mesh_state* mstate); 489 490 /** 491 * Cleanup a mesh state and its query state. Does not do rbtree or 492 * reference cleanup. 493 * @param mstate: mesh state to cleanup. Its pointer may no longer be used 494 * afterwards. Cleanup rbtrees before calling this function. 495 */ 496 void mesh_state_cleanup(struct mesh_state* mstate); 497 498 /** 499 * Delete all mesh states from the mesh. 500 * @param mesh: the mesh area to clear 501 */ 502 void mesh_delete_all(struct mesh_area* mesh); 503 504 /** 505 * Find a mesh state in the mesh area. Pass relevant flags. 506 * 507 * @param mesh: the mesh area to look in. 508 * @param cinfo: if non-NULL client specific info that may affect IP-based 509 * actions that apply to the query result. 510 * @param qinfo: what query 511 * @param qflags: if RD / CD bit is set or not. 512 * @param prime: if it is a priming query. 513 * @param valrec: if it is a validation-recursion query. 514 * @return: mesh state or NULL if not found. 515 */ 516 struct mesh_state* mesh_area_find(struct mesh_area* mesh, 517 struct respip_client_info* cinfo, struct query_info* qinfo, 518 uint16_t qflags, int prime, int valrec); 519 520 /** 521 * Setup attachment super/sub relation between super and sub mesh state. 522 * The relation must not be present when calling the function. 523 * Does not update stat items in mesh_area. 524 * @param super: super state. 525 * @param sub: sub state. 526 * @return: 0 on alloc error. 527 */ 528 int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub); 529 530 /** 531 * Create new reply structure and attach it to a mesh state. 532 * Does not update stat items in mesh area. 533 * @param s: the mesh state. 534 * @param edns: edns data for reply (bufsize). 535 * @param rep: comm point reply info. 536 * @param qid: ID of reply. 537 * @param qflags: original query flags. 538 * @param qinfo: original query info. 539 * @return: 0 on alloc error. 540 */ 541 int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns, 542 struct comm_reply* rep, uint16_t qid, uint16_t qflags, 543 const struct query_info* qinfo); 544 545 /** 546 * Create new callback structure and attach it to a mesh state. 547 * Does not update stat items in mesh area. 548 * @param s: the mesh state. 549 * @param edns: edns data for reply (bufsize). 550 * @param buf: buffer for reply 551 * @param cb: callback to call with results. 552 * @param cb_arg: callback user arg. 553 * @param qid: ID of reply. 554 * @param qflags: original query flags. 555 * @return: 0 on alloc error. 556 */ 557 int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns, 558 struct sldns_buffer* buf, mesh_cb_func_type cb, void* cb_arg, 559 uint16_t qid, uint16_t qflags); 560 561 /** 562 * Run the mesh. Run all runnable mesh states. Which can create new 563 * runnable mesh states. Until completion. Automatically called by 564 * mesh_report_reply and mesh_new_client as needed. 565 * @param mesh: mesh area. 566 * @param mstate: first mesh state to run. 567 * @param ev: event the mstate. Others get event_pass. 568 * @param e: if a reply, its outbound entry. 569 */ 570 void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate, 571 enum module_ev ev, struct outbound_entry* e); 572 573 /** 574 * Print some stats about the mesh to the log. 575 * @param mesh: the mesh to print it for. 576 * @param str: descriptive string to go with it. 577 */ 578 void mesh_stats(struct mesh_area* mesh, const char* str); 579 580 /** 581 * Clear the stats that the mesh keeps (number of queries serviced) 582 * @param mesh: the mesh 583 */ 584 void mesh_stats_clear(struct mesh_area* mesh); 585 586 /** 587 * Print all the states in the mesh to the log. 588 * @param mesh: the mesh to print all states of. 589 */ 590 void mesh_log_list(struct mesh_area* mesh); 591 592 /** 593 * Calculate memory size in use by mesh and all queries inside it. 594 * @param mesh: the mesh to examine. 595 * @return size in bytes. 596 */ 597 size_t mesh_get_mem(struct mesh_area* mesh); 598 599 /** 600 * Find cycle; see if the given mesh is in the targets sub, or sub-sub, ... 601 * trees. 602 * If the sub-sub structure is too large, it returns 'a cycle'=2. 603 * @param qstate: given mesh querystate. 604 * @param qinfo: query info for dependency. 605 * @param flags: query flags of dependency. 606 * @param prime: if dependency is a priming query or not. 607 * @param valrec: if it is a validation recursion query (lookup of key, DS). 608 * @return true if the name,type,class exists and the given qstate mesh exists 609 * as a dependency of that name. Thus if qstate becomes dependent on 610 * name,type,class then a cycle is created, this is return value 1. 611 * Too large to search is value 2 (also true). 612 */ 613 int mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo, 614 uint16_t flags, int prime, int valrec); 615 616 /** compare two mesh_states */ 617 int mesh_state_compare(const void* ap, const void* bp); 618 619 /** compare two mesh references */ 620 int mesh_state_ref_compare(const void* ap, const void* bp); 621 622 /** 623 * Make space for another recursion state for a reply in the mesh 624 * @param mesh: mesh area 625 * @param qbuf: query buffer to save if recursion is invoked to make space. 626 * This buffer is necessary, because the following sequence in calls 627 * can result in an overwrite of the incoming query: 628 * delete_other_mesh_query - iter_clean - serviced_delete - waiting 629 * udp query is sent - on error callback - callback sends SERVFAIL reply 630 * over the same network channel, and shared UDP buffer is overwritten. 631 * You can pass NULL if there is no buffer that must be backed up. 632 * @return false if no space is available. 633 */ 634 int mesh_make_new_space(struct mesh_area* mesh, struct sldns_buffer* qbuf); 635 636 /** 637 * Insert mesh state into a double linked list. Inserted at end. 638 * @param m: mesh state. 639 * @param fp: pointer to the first-elem-pointer of the list. 640 * @param lp: pointer to the last-elem-pointer of the list. 641 */ 642 void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp, 643 struct mesh_state** lp); 644 645 /** 646 * Remove mesh state from a double linked list. Remove from any position. 647 * @param m: mesh state. 648 * @param fp: pointer to the first-elem-pointer of the list. 649 * @param lp: pointer to the last-elem-pointer of the list. 650 */ 651 void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp, 652 struct mesh_state** lp); 653 654 /** 655 * Remove mesh reply entry from the reply entry list. Searches for 656 * the comm_point pointer. 657 * @param mesh: to update the counters. 658 * @param m: the mesh state. 659 * @param cp: the comm_point to remove from the list. 660 */ 661 void mesh_state_remove_reply(struct mesh_area* mesh, struct mesh_state* m, 662 struct comm_point* cp); 663 664 /** Callback for when the serve expired client timer has run out. Tries to 665 * find an expired answer in the cache and reply that to the client. 666 * @param arg: the argument passed to the callback. 667 */ 668 void mesh_serve_expired_callback(void* arg); 669 670 /** 671 * Try to get a (expired) cached answer. 672 * This needs to behave like the worker's answer_from_cache() in order to have 673 * the same behavior as when replying from cache. 674 * @param qstate: the module qstate. 675 * @param lookup_qinfo: the query info to look for in the cache. 676 * @param is_expired: set if the cached answer is expired. 677 * @return dns_msg if a cached answer was found, otherwise NULL. 678 */ 679 struct dns_msg* 680 mesh_serve_expired_lookup(struct module_qstate* qstate, 681 struct query_info* lookup_qinfo, int* is_expired); 682 683 /** 684 * See if the mesh has space for more queries. You can allocate queries 685 * anyway, but this checks for the allocated space. 686 * @param mesh: mesh area. 687 * @return true if the query list is full. 688 * It checks the number of all queries, not just number of reply states, 689 * that have a client address. So that spawned queries count too, 690 * that were created by the iterator, or other modules. 691 */ 692 int mesh_jostle_exceeded(struct mesh_area* mesh); 693 694 /** 695 * Give the serve expired responses. 696 * @param mstate: mesh state for query that has serve_expired_data. 697 */ 698 void mesh_respond_serve_expired(struct mesh_state* mstate); 699 700 #endif /* SERVICES_MESH_H */ 701