iterator.c revision 275854
1/* 2 * iterator/iterator.c - iterative resolver DNS query response module 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 LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36/** 37 * \file 38 * 39 * This file contains a module that performs recusive iterative DNS query 40 * processing. 41 */ 42 43#include "config.h" 44#include <ldns/ldns.h> 45#include "iterator/iterator.h" 46#include "iterator/iter_utils.h" 47#include "iterator/iter_hints.h" 48#include "iterator/iter_fwd.h" 49#include "iterator/iter_donotq.h" 50#include "iterator/iter_delegpt.h" 51#include "iterator/iter_resptype.h" 52#include "iterator/iter_scrub.h" 53#include "iterator/iter_priv.h" 54#include "validator/val_neg.h" 55#include "services/cache/dns.h" 56#include "services/cache/infra.h" 57#include "util/module.h" 58#include "util/netevent.h" 59#include "util/net_help.h" 60#include "util/regional.h" 61#include "util/data/dname.h" 62#include "util/data/msgencode.h" 63#include "util/fptr_wlist.h" 64#include "util/config_file.h" 65 66int 67iter_init(struct module_env* env, int id) 68{ 69 struct iter_env* iter_env = (struct iter_env*)calloc(1, 70 sizeof(struct iter_env)); 71 if(!iter_env) { 72 log_err("malloc failure"); 73 return 0; 74 } 75 env->modinfo[id] = (void*)iter_env; 76 if(!iter_apply_cfg(iter_env, env->cfg)) { 77 log_err("iterator: could not apply configuration settings."); 78 return 0; 79 } 80 return 1; 81} 82 83void 84iter_deinit(struct module_env* env, int id) 85{ 86 struct iter_env* iter_env; 87 if(!env || !env->modinfo[id]) 88 return; 89 iter_env = (struct iter_env*)env->modinfo[id]; 90 free(iter_env->target_fetch_policy); 91 priv_delete(iter_env->priv); 92 donotq_delete(iter_env->donotq); 93 free(iter_env); 94 env->modinfo[id] = NULL; 95} 96 97/** new query for iterator */ 98static int 99iter_new(struct module_qstate* qstate, int id) 100{ 101 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( 102 qstate->region, sizeof(struct iter_qstate)); 103 qstate->minfo[id] = iq; 104 if(!iq) 105 return 0; 106 memset(iq, 0, sizeof(*iq)); 107 iq->state = INIT_REQUEST_STATE; 108 iq->final_state = FINISHED_STATE; 109 iq->an_prepend_list = NULL; 110 iq->an_prepend_last = NULL; 111 iq->ns_prepend_list = NULL; 112 iq->ns_prepend_last = NULL; 113 iq->dp = NULL; 114 iq->depth = 0; 115 iq->num_target_queries = 0; 116 iq->num_current_queries = 0; 117 iq->query_restart_count = 0; 118 iq->referral_count = 0; 119 iq->sent_count = 0; 120 iq->target_count = NULL; 121 iq->wait_priming_stub = 0; 122 iq->refetch_glue = 0; 123 iq->dnssec_expected = 0; 124 iq->dnssec_lame_query = 0; 125 iq->chase_flags = qstate->query_flags; 126 /* Start with the (current) qname. */ 127 iq->qchase = qstate->qinfo; 128 outbound_list_init(&iq->outlist); 129 return 1; 130} 131 132/** 133 * Transition to the next state. This can be used to advance a currently 134 * processing event. It cannot be used to reactivate a forEvent. 135 * 136 * @param iq: iterator query state 137 * @param nextstate The state to transition to. 138 * @return true. This is so this can be called as the return value for the 139 * actual process*State() methods. (Transitioning to the next state 140 * implies further processing). 141 */ 142static int 143next_state(struct iter_qstate* iq, enum iter_state nextstate) 144{ 145 /* If transitioning to a "response" state, make sure that there is a 146 * response */ 147 if(iter_state_is_responsestate(nextstate)) { 148 if(iq->response == NULL) { 149 log_err("transitioning to response state sans " 150 "response."); 151 } 152 } 153 iq->state = nextstate; 154 return 1; 155} 156 157/** 158 * Transition an event to its final state. Final states always either return 159 * a result up the module chain, or reactivate a dependent event. Which 160 * final state to transtion to is set in the module state for the event when 161 * it was created, and depends on the original purpose of the event. 162 * 163 * The response is stored in the qstate->buf buffer. 164 * 165 * @param iq: iterator query state 166 * @return false. This is so this method can be used as the return value for 167 * the processState methods. (Transitioning to the final state 168 */ 169static int 170final_state(struct iter_qstate* iq) 171{ 172 return next_state(iq, iq->final_state); 173} 174 175/** 176 * Callback routine to handle errors in parent query states 177 * @param qstate: query state that failed. 178 * @param id: module id. 179 * @param super: super state. 180 */ 181static void 182error_supers(struct module_qstate* qstate, int id, struct module_qstate* super) 183{ 184 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; 185 186 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || 187 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { 188 /* mark address as failed. */ 189 struct delegpt_ns* dpns = NULL; 190 if(super_iq->dp) 191 dpns = delegpt_find_ns(super_iq->dp, 192 qstate->qinfo.qname, qstate->qinfo.qname_len); 193 if(!dpns) { 194 /* not interested */ 195 verbose(VERB_ALGO, "subq error, but not interested"); 196 log_query_info(VERB_ALGO, "superq", &super->qinfo); 197 if(super_iq->dp) 198 delegpt_log(VERB_ALGO, super_iq->dp); 199 log_assert(0); 200 return; 201 } else { 202 /* see if the failure did get (parent-lame) info */ 203 if(!cache_fill_missing(super->env, 204 super_iq->qchase.qclass, super->region, 205 super_iq->dp)) 206 log_err("out of memory adding missing"); 207 } 208 dpns->resolved = 1; /* mark as failed */ 209 super_iq->num_target_queries--; 210 } 211 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { 212 /* prime failed to get delegation */ 213 super_iq->dp = NULL; 214 } 215 /* evaluate targets again */ 216 super_iq->state = QUERYTARGETS_STATE; 217 /* super becomes runnable, and will process this change */ 218} 219 220/** 221 * Return an error to the client 222 * @param qstate: our query state 223 * @param id: module id 224 * @param rcode: error code (DNS errcode). 225 * @return: 0 for use by caller, to make notation easy, like: 226 * return error_response(..). 227 */ 228static int 229error_response(struct module_qstate* qstate, int id, int rcode) 230{ 231 verbose(VERB_QUERY, "return error response %s", 232 ldns_lookup_by_id(ldns_rcodes, rcode)? 233 ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??"); 234 qstate->return_rcode = rcode; 235 qstate->return_msg = NULL; 236 qstate->ext_state[id] = module_finished; 237 return 0; 238} 239 240/** 241 * Return an error to the client and cache the error code in the 242 * message cache (so per qname, qtype, qclass). 243 * @param qstate: our query state 244 * @param id: module id 245 * @param rcode: error code (DNS errcode). 246 * @return: 0 for use by caller, to make notation easy, like: 247 * return error_response(..). 248 */ 249static int 250error_response_cache(struct module_qstate* qstate, int id, int rcode) 251{ 252 /* store in cache */ 253 struct reply_info err; 254 memset(&err, 0, sizeof(err)); 255 err.flags = (uint16_t)(BIT_QR | BIT_RA); 256 FLAGS_SET_RCODE(err.flags, rcode); 257 err.qdcount = 1; 258 err.ttl = NORR_TTL; 259 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); 260 /* do not waste time trying to validate this servfail */ 261 err.security = sec_status_indeterminate; 262 verbose(VERB_ALGO, "store error response in message cache"); 263 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL); 264 return error_response(qstate, id, rcode); 265} 266 267/** check if prepend item is duplicate item */ 268static int 269prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, 270 struct ub_packed_rrset_key* dup) 271{ 272 size_t i; 273 for(i=0; i<to; i++) { 274 if(sets[i]->rk.type == dup->rk.type && 275 sets[i]->rk.rrset_class == dup->rk.rrset_class && 276 sets[i]->rk.dname_len == dup->rk.dname_len && 277 query_dname_compare(sets[i]->rk.dname, dup->rk.dname) 278 == 0) 279 return 1; 280 } 281 return 0; 282} 283 284/** prepend the prepend list in the answer and authority section of dns_msg */ 285static int 286iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, 287 struct regional* region) 288{ 289 struct iter_prep_list* p; 290 struct ub_packed_rrset_key** sets; 291 size_t num_an = 0, num_ns = 0;; 292 for(p = iq->an_prepend_list; p; p = p->next) 293 num_an++; 294 for(p = iq->ns_prepend_list; p; p = p->next) 295 num_ns++; 296 if(num_an + num_ns == 0) 297 return 1; 298 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); 299 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * 300 sizeof(struct ub_packed_rrset_key*)); 301 if(!sets) 302 return 0; 303 /* ANSWER section */ 304 num_an = 0; 305 for(p = iq->an_prepend_list; p; p = p->next) { 306 sets[num_an++] = p->rrset; 307 } 308 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * 309 sizeof(struct ub_packed_rrset_key*)); 310 /* AUTH section */ 311 num_ns = 0; 312 for(p = iq->ns_prepend_list; p; p = p->next) { 313 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, 314 num_ns, p->rrset) || prepend_is_duplicate( 315 msg->rep->rrsets+msg->rep->an_numrrsets, 316 msg->rep->ns_numrrsets, p->rrset)) 317 continue; 318 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; 319 } 320 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, 321 msg->rep->rrsets + msg->rep->an_numrrsets, 322 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * 323 sizeof(struct ub_packed_rrset_key*)); 324 325 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because 326 * this is what recursors should give. */ 327 msg->rep->rrset_count += num_an + num_ns; 328 msg->rep->an_numrrsets += num_an; 329 msg->rep->ns_numrrsets += num_ns; 330 msg->rep->rrsets = sets; 331 return 1; 332} 333 334/** 335 * Add rrset to ANSWER prepend list 336 * @param qstate: query state. 337 * @param iq: iterator query state. 338 * @param rrset: rrset to add. 339 * @return false on failure (malloc). 340 */ 341static int 342iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, 343 struct ub_packed_rrset_key* rrset) 344{ 345 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 346 qstate->region, sizeof(struct iter_prep_list)); 347 if(!p) 348 return 0; 349 p->rrset = rrset; 350 p->next = NULL; 351 /* add at end */ 352 if(iq->an_prepend_last) 353 iq->an_prepend_last->next = p; 354 else iq->an_prepend_list = p; 355 iq->an_prepend_last = p; 356 return 1; 357} 358 359/** 360 * Add rrset to AUTHORITY prepend list 361 * @param qstate: query state. 362 * @param iq: iterator query state. 363 * @param rrset: rrset to add. 364 * @return false on failure (malloc). 365 */ 366static int 367iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, 368 struct ub_packed_rrset_key* rrset) 369{ 370 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 371 qstate->region, sizeof(struct iter_prep_list)); 372 if(!p) 373 return 0; 374 p->rrset = rrset; 375 p->next = NULL; 376 /* add at end */ 377 if(iq->ns_prepend_last) 378 iq->ns_prepend_last->next = p; 379 else iq->ns_prepend_list = p; 380 iq->ns_prepend_last = p; 381 return 1; 382} 383 384/** 385 * Given a CNAME response (defined as a response containing a CNAME or DNAME 386 * that does not answer the request), process the response, modifying the 387 * state as necessary. This follows the CNAME/DNAME chain and returns the 388 * final query name. 389 * 390 * sets the new query name, after following the CNAME/DNAME chain. 391 * @param qstate: query state. 392 * @param iq: iterator query state. 393 * @param msg: the response. 394 * @param mname: returned target new query name. 395 * @param mname_len: length of mname. 396 * @return false on (malloc) error. 397 */ 398static int 399handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, 400 struct dns_msg* msg, uint8_t** mname, size_t* mname_len) 401{ 402 size_t i; 403 /* Start with the (current) qname. */ 404 *mname = iq->qchase.qname; 405 *mname_len = iq->qchase.qname_len; 406 407 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and 408 * DNAMES. */ 409 for(i=0; i<msg->rep->an_numrrsets; i++) { 410 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 411 /* If there is a (relevant) DNAME, add it to the list. 412 * We always expect there to be CNAME that was generated 413 * by this DNAME following, so we don't process the DNAME 414 * directly. */ 415 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && 416 dname_strict_subdomain_c(*mname, r->rk.dname)) { 417 if(!iter_add_prepend_answer(qstate, iq, r)) 418 return 0; 419 continue; 420 } 421 422 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && 423 query_dname_compare(*mname, r->rk.dname) == 0) { 424 /* Add this relevant CNAME rrset to the prepend list.*/ 425 if(!iter_add_prepend_answer(qstate, iq, r)) 426 return 0; 427 get_cname_target(r, mname, mname_len); 428 } 429 430 /* Other rrsets in the section are ignored. */ 431 } 432 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ 433 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + 434 msg->rep->ns_numrrsets; i++) { 435 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 436 /* only add NSEC/NSEC3, as they may be needed for validation */ 437 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC || 438 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { 439 if(!iter_add_prepend_auth(qstate, iq, r)) 440 return 0; 441 } 442 } 443 return 1; 444} 445 446/** create target count structure for this query */ 447static void 448target_count_create(struct iter_qstate* iq) 449{ 450 if(!iq->target_count) { 451 iq->target_count = (int*)calloc(2, sizeof(int)); 452 /* if calloc fails we simply do not track this number */ 453 if(iq->target_count) 454 iq->target_count[0] = 1; 455 } 456} 457 458static void 459target_count_increase(struct iter_qstate* iq, int num) 460{ 461 target_count_create(iq); 462 if(iq->target_count) 463 iq->target_count[1] += num; 464} 465 466/** 467 * Generate a subrequest. 468 * Generate a local request event. Local events are tied to this module, and 469 * have a correponding (first tier) event that is waiting for this event to 470 * resolve to continue. 471 * 472 * @param qname The query name for this request. 473 * @param qnamelen length of qname 474 * @param qtype The query type for this request. 475 * @param qclass The query class for this request. 476 * @param qstate The event that is generating this event. 477 * @param id: module id. 478 * @param iq: The iterator state that is generating this event. 479 * @param initial_state The initial response state (normally this 480 * is QUERY_RESP_STATE, unless it is known that the request won't 481 * need iterative processing 482 * @param finalstate The final state for the response to this request. 483 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does 484 * not need initialisation. 485 * @param v: if true, validation is done on the subquery. 486 * @return false on error (malloc). 487 */ 488static int 489generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, 490 uint16_t qclass, struct module_qstate* qstate, int id, 491 struct iter_qstate* iq, enum iter_state initial_state, 492 enum iter_state finalstate, struct module_qstate** subq_ret, int v) 493{ 494 struct module_qstate* subq = NULL; 495 struct iter_qstate* subiq = NULL; 496 uint16_t qflags = 0; /* OPCODE QUERY, no flags */ 497 struct query_info qinf; 498 int prime = (finalstate == PRIME_RESP_STATE)?1:0; 499 qinf.qname = qname; 500 qinf.qname_len = qnamelen; 501 qinf.qtype = qtype; 502 qinf.qclass = qclass; 503 504 /* RD should be set only when sending the query back through the INIT 505 * state. */ 506 if(initial_state == INIT_REQUEST_STATE) 507 qflags |= BIT_RD; 508 /* We set the CD flag so we can send this through the "head" of 509 * the resolution chain, which might have a validator. We are 510 * uninterested in validating things not on the direct resolution 511 * path. */ 512 if(!v) 513 qflags |= BIT_CD; 514 515 /* attach subquery, lookup existing or make a new one */ 516 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub)); 517 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, &subq)) { 518 return 0; 519 } 520 *subq_ret = subq; 521 if(subq) { 522 /* initialise the new subquery */ 523 subq->curmod = id; 524 subq->ext_state[id] = module_state_initial; 525 subq->minfo[id] = regional_alloc(subq->region, 526 sizeof(struct iter_qstate)); 527 if(!subq->minfo[id]) { 528 log_err("init subq: out of memory"); 529 fptr_ok(fptr_whitelist_modenv_kill_sub( 530 qstate->env->kill_sub)); 531 (*qstate->env->kill_sub)(subq); 532 return 0; 533 } 534 subiq = (struct iter_qstate*)subq->minfo[id]; 535 memset(subiq, 0, sizeof(*subiq)); 536 subiq->num_target_queries = 0; 537 target_count_create(iq); 538 subiq->target_count = iq->target_count; 539 if(iq->target_count) 540 iq->target_count[0] ++; /* extra reference */ 541 subiq->num_current_queries = 0; 542 subiq->depth = iq->depth+1; 543 outbound_list_init(&subiq->outlist); 544 subiq->state = initial_state; 545 subiq->final_state = finalstate; 546 subiq->qchase = subq->qinfo; 547 subiq->chase_flags = subq->query_flags; 548 subiq->refetch_glue = 0; 549 } 550 return 1; 551} 552 553/** 554 * Generate and send a root priming request. 555 * @param qstate: the qtstate that triggered the need to prime. 556 * @param iq: iterator query state. 557 * @param id: module id. 558 * @param qclass: the class to prime. 559 * @return 0 on failure 560 */ 561static int 562prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id, 563 uint16_t qclass) 564{ 565 struct delegpt* dp; 566 struct module_qstate* subq; 567 verbose(VERB_DETAIL, "priming . %s NS", 568 ldns_lookup_by_id(ldns_rr_classes, (int)qclass)? 569 ldns_lookup_by_id(ldns_rr_classes, (int)qclass)->name:"??"); 570 dp = hints_lookup_root(qstate->env->hints, qclass); 571 if(!dp) { 572 verbose(VERB_ALGO, "Cannot prime due to lack of hints"); 573 return 0; 574 } 575 /* Priming requests start at the QUERYTARGETS state, skipping 576 * the normal INIT state logic (which would cause an infloop). */ 577 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, 578 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE, 579 &subq, 0)) { 580 verbose(VERB_ALGO, "could not prime root"); 581 return 0; 582 } 583 if(subq) { 584 struct iter_qstate* subiq = 585 (struct iter_qstate*)subq->minfo[id]; 586 /* Set the initial delegation point to the hint. 587 * copy dp, it is now part of the root prime query. 588 * dp was part of in the fixed hints structure. */ 589 subiq->dp = delegpt_copy(dp, subq->region); 590 if(!subiq->dp) { 591 log_err("out of memory priming root, copydp"); 592 fptr_ok(fptr_whitelist_modenv_kill_sub( 593 qstate->env->kill_sub)); 594 (*qstate->env->kill_sub)(subq); 595 return 0; 596 } 597 /* there should not be any target queries. */ 598 subiq->num_target_queries = 0; 599 subiq->dnssec_expected = iter_indicates_dnssec( 600 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 601 } 602 603 /* this module stops, our submodule starts, and does the query. */ 604 qstate->ext_state[id] = module_wait_subquery; 605 return 1; 606} 607 608/** 609 * Generate and process a stub priming request. This method tests for the 610 * need to prime a stub zone, so it is safe to call for every request. 611 * 612 * @param qstate: the qtstate that triggered the need to prime. 613 * @param iq: iterator query state. 614 * @param id: module id. 615 * @param qname: request name. 616 * @param qclass: request class. 617 * @return true if a priming subrequest was made, false if not. The will only 618 * issue a priming request if it detects an unprimed stub. 619 * Uses value of 2 to signal during stub-prime in root-prime situation 620 * that a noprime-stub is available and resolution can continue. 621 */ 622static int 623prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id, 624 uint8_t* qname, uint16_t qclass) 625{ 626 /* Lookup the stub hint. This will return null if the stub doesn't 627 * need to be re-primed. */ 628 struct iter_hints_stub* stub; 629 struct delegpt* stub_dp; 630 struct module_qstate* subq; 631 632 if(!qname) return 0; 633 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp); 634 /* The stub (if there is one) does not need priming. */ 635 if(!stub) 636 return 0; 637 stub_dp = stub->dp; 638 639 /* is it a noprime stub (always use) */ 640 if(stub->noprime) { 641 int r = 0; 642 if(iq->dp == NULL) r = 2; 643 /* copy the dp out of the fixed hints structure, so that 644 * it can be changed when servicing this query */ 645 iq->dp = delegpt_copy(stub_dp, qstate->region); 646 if(!iq->dp) { 647 log_err("out of memory priming stub"); 648 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 649 return 1; /* return 1 to make module stop, with error */ 650 } 651 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name, 652 LDNS_RR_TYPE_NS, qclass); 653 return r; 654 } 655 656 /* Otherwise, we need to (re)prime the stub. */ 657 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name, 658 LDNS_RR_TYPE_NS, qclass); 659 660 /* Stub priming events start at the QUERYTARGETS state to avoid the 661 * redundant INIT state processing. */ 662 if(!generate_sub_request(stub_dp->name, stub_dp->namelen, 663 LDNS_RR_TYPE_NS, qclass, qstate, id, iq, 664 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) { 665 verbose(VERB_ALGO, "could not prime stub"); 666 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 667 return 1; /* return 1 to make module stop, with error */ 668 } 669 if(subq) { 670 struct iter_qstate* subiq = 671 (struct iter_qstate*)subq->minfo[id]; 672 673 /* Set the initial delegation point to the hint. */ 674 /* make copy to avoid use of stub dp by different qs/threads */ 675 subiq->dp = delegpt_copy(stub_dp, subq->region); 676 if(!subiq->dp) { 677 log_err("out of memory priming stub, copydp"); 678 fptr_ok(fptr_whitelist_modenv_kill_sub( 679 qstate->env->kill_sub)); 680 (*qstate->env->kill_sub)(subq); 681 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 682 return 1; /* return 1 to make module stop, with error */ 683 } 684 /* there should not be any target queries -- although there 685 * wouldn't be anyway, since stub hints never have 686 * missing targets. */ 687 subiq->num_target_queries = 0; 688 subiq->wait_priming_stub = 1; 689 subiq->dnssec_expected = iter_indicates_dnssec( 690 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 691 } 692 693 /* this module stops, our submodule starts, and does the query. */ 694 qstate->ext_state[id] = module_wait_subquery; 695 return 1; 696} 697 698/** 699 * Generate A and AAAA checks for glue that is in-zone for the referral 700 * we just got to obtain authoritative information on the adresses. 701 * 702 * @param qstate: the qtstate that triggered the need to prime. 703 * @param iq: iterator query state. 704 * @param id: module id. 705 */ 706static void 707generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq, 708 int id) 709{ 710 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 711 struct module_qstate* subq; 712 size_t i; 713 struct reply_info* rep = iq->response->rep; 714 struct ub_packed_rrset_key* s; 715 log_assert(iq->dp); 716 717 if(iq->depth == ie->max_dependency_depth) 718 return; 719 /* walk through additional, and check if in-zone, 720 * only relevant A, AAAA are left after scrub anyway */ 721 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { 722 s = rep->rrsets[i]; 723 /* check *ALL* addresses that are transmitted in additional*/ 724 /* is it an address ? */ 725 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A || 726 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) { 727 continue; 728 } 729 /* is this query the same as the A/AAAA check for it */ 730 if(qstate->qinfo.qtype == ntohs(s->rk.type) && 731 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) && 732 query_dname_compare(qstate->qinfo.qname, 733 s->rk.dname)==0 && 734 (qstate->query_flags&BIT_RD) && 735 !(qstate->query_flags&BIT_CD)) 736 continue; 737 738 /* generate subrequest for it */ 739 log_nametypeclass(VERB_ALGO, "schedule addr fetch", 740 s->rk.dname, ntohs(s->rk.type), 741 ntohs(s->rk.rrset_class)); 742 if(!generate_sub_request(s->rk.dname, s->rk.dname_len, 743 ntohs(s->rk.type), ntohs(s->rk.rrset_class), 744 qstate, id, iq, 745 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 746 verbose(VERB_ALGO, "could not generate addr check"); 747 return; 748 } 749 /* ignore subq - not need for more init */ 750 } 751} 752 753/** 754 * Generate a NS check request to obtain authoritative information 755 * on an NS rrset. 756 * 757 * @param qstate: the qtstate that triggered the need to prime. 758 * @param iq: iterator query state. 759 * @param id: module id. 760 */ 761static void 762generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id) 763{ 764 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 765 struct module_qstate* subq; 766 log_assert(iq->dp); 767 768 if(iq->depth == ie->max_dependency_depth) 769 return; 770 /* is this query the same as the nscheck? */ 771 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS && 772 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 773 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 774 /* spawn off A, AAAA queries for in-zone glue to check */ 775 generate_a_aaaa_check(qstate, iq, id); 776 return; 777 } 778 779 log_nametypeclass(VERB_ALGO, "schedule ns fetch", 780 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 781 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 782 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 783 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 784 verbose(VERB_ALGO, "could not generate ns check"); 785 return; 786 } 787 if(subq) { 788 struct iter_qstate* subiq = 789 (struct iter_qstate*)subq->minfo[id]; 790 791 /* make copy to avoid use of stub dp by different qs/threads */ 792 /* refetch glue to start higher up the tree */ 793 subiq->refetch_glue = 1; 794 subiq->dp = delegpt_copy(iq->dp, subq->region); 795 if(!subiq->dp) { 796 log_err("out of memory generating ns check, copydp"); 797 fptr_ok(fptr_whitelist_modenv_kill_sub( 798 qstate->env->kill_sub)); 799 (*qstate->env->kill_sub)(subq); 800 return; 801 } 802 } 803} 804 805/** 806 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we 807 * just got in a referral (where we have dnssec_expected, thus have trust 808 * anchors above it). Note that right after calling this routine the 809 * iterator detached subqueries (because of following the referral), and thus 810 * the DNSKEY query becomes detached, its return stored in the cache for 811 * later lookup by the validator. This cache lookup by the validator avoids 812 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now 813 * performed at about the same time the original query is sent to the domain, 814 * thus the two answers are likely to be returned at about the same time, 815 * saving a roundtrip from the validated lookup. 816 * 817 * @param qstate: the qtstate that triggered the need to prime. 818 * @param iq: iterator query state. 819 * @param id: module id. 820 */ 821static void 822generate_dnskey_prefetch(struct module_qstate* qstate, 823 struct iter_qstate* iq, int id) 824{ 825 struct module_qstate* subq; 826 log_assert(iq->dp); 827 828 /* is this query the same as the prefetch? */ 829 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY && 830 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 831 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 832 return; 833 } 834 835 /* if the DNSKEY is in the cache this lookup will stop quickly */ 836 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch", 837 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass); 838 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 839 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq, 840 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 841 /* we'll be slower, but it'll work */ 842 verbose(VERB_ALGO, "could not generate dnskey prefetch"); 843 return; 844 } 845 if(subq) { 846 struct iter_qstate* subiq = 847 (struct iter_qstate*)subq->minfo[id]; 848 /* this qstate has the right delegation for the dnskey lookup*/ 849 /* make copy to avoid use of stub dp by different qs/threads */ 850 subiq->dp = delegpt_copy(iq->dp, subq->region); 851 /* if !subiq->dp, it'll start from the cache, no problem */ 852 } 853} 854 855/** 856 * See if the query needs forwarding. 857 * 858 * @param qstate: query state. 859 * @param iq: iterator query state. 860 * @return true if the request is forwarded, false if not. 861 * If returns true but, iq->dp is NULL then a malloc failure occurred. 862 */ 863static int 864forward_request(struct module_qstate* qstate, struct iter_qstate* iq) 865{ 866 struct delegpt* dp; 867 uint8_t* delname = iq->qchase.qname; 868 size_t delnamelen = iq->qchase.qname_len; 869 if(iq->refetch_glue) { 870 delname = iq->dp->name; 871 delnamelen = iq->dp->namelen; 872 } 873 /* strip one label off of DS query to lookup higher for it */ 874 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) 875 && !dname_is_root(iq->qchase.qname)) 876 dname_remove_label(&delname, &delnamelen); 877 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass); 878 if(!dp) 879 return 0; 880 /* send recursion desired to forward addr */ 881 iq->chase_flags |= BIT_RD; 882 iq->dp = delegpt_copy(dp, qstate->region); 883 /* iq->dp checked by caller */ 884 verbose(VERB_ALGO, "forwarding request"); 885 return 1; 886} 887 888/** 889 * Process the initial part of the request handling. This state roughly 890 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2 891 * (find the best servers to ask). 892 * 893 * Note that all requests start here, and query restarts revisit this state. 894 * 895 * This state either generates: 1) a response, from cache or error, 2) a 896 * priming event, or 3) forwards the request to the next state (init2, 897 * generally). 898 * 899 * @param qstate: query state. 900 * @param iq: iterator query state. 901 * @param ie: iterator shared global environment. 902 * @param id: module id. 903 * @return true if the event needs more request processing immediately, 904 * false if not. 905 */ 906static int 907processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq, 908 struct iter_env* ie, int id) 909{ 910 uint8_t* delname; 911 size_t delnamelen; 912 struct dns_msg* msg; 913 914 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo); 915 /* check effort */ 916 917 /* We enforce a maximum number of query restarts. This is primarily a 918 * cheap way to prevent CNAME loops. */ 919 if(iq->query_restart_count > MAX_RESTART_COUNT) { 920 verbose(VERB_QUERY, "request has exceeded the maximum number" 921 " of query restarts with %d", iq->query_restart_count); 922 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 923 } 924 925 /* We enforce a maximum recursion/dependency depth -- in general, 926 * this is unnecessary for dependency loops (although it will 927 * catch those), but it provides a sensible limit to the amount 928 * of work required to answer a given query. */ 929 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth); 930 if(iq->depth > ie->max_dependency_depth) { 931 verbose(VERB_QUERY, "request has exceeded the maximum " 932 "dependency depth with depth of %d", iq->depth); 933 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 934 } 935 936 /* If the request is qclass=ANY, setup to generate each class */ 937 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) { 938 iq->qchase.qclass = 0; 939 return next_state(iq, COLLECT_CLASS_STATE); 940 } 941 942 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */ 943 944 /* This either results in a query restart (CNAME cache response), a 945 * terminating response (ANSWER), or a cache miss (null). */ 946 947 if(qstate->blacklist) { 948 /* if cache, or anything else, was blacklisted then 949 * getting older results from cache is a bad idea, no cache */ 950 verbose(VERB_ALGO, "cache blacklisted, going to the network"); 951 msg = NULL; 952 } else { 953 msg = dns_cache_lookup(qstate->env, iq->qchase.qname, 954 iq->qchase.qname_len, iq->qchase.qtype, 955 iq->qchase.qclass, qstate->region, qstate->env->scratch); 956 if(!msg && qstate->env->neg_cache) { 957 /* lookup in negative cache; may result in 958 * NOERROR/NODATA or NXDOMAIN answers that need validation */ 959 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase, 960 qstate->region, qstate->env->rrset_cache, 961 qstate->env->scratch_buffer, 962 *qstate->env->now, 1/*add SOA*/, NULL); 963 } 964 /* item taken from cache does not match our query name, thus 965 * security needs to be re-examined later */ 966 if(msg && query_dname_compare(qstate->qinfo.qname, 967 iq->qchase.qname) != 0) 968 msg->rep->security = sec_status_unchecked; 969 } 970 if(msg) { 971 /* handle positive cache response */ 972 enum response_type type = response_type_from_cache(msg, 973 &iq->qchase); 974 if(verbosity >= VERB_ALGO) { 975 log_dns_msg("msg from cache lookup", &msg->qinfo, 976 msg->rep); 977 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d", 978 (int)msg->rep->ttl, 979 (int)msg->rep->prefetch_ttl); 980 } 981 982 if(type == RESPONSE_TYPE_CNAME) { 983 uint8_t* sname = 0; 984 size_t slen = 0; 985 verbose(VERB_ALGO, "returning CNAME response from " 986 "cache"); 987 if(!handle_cname_response(qstate, iq, msg, 988 &sname, &slen)) 989 return error_response(qstate, id, 990 LDNS_RCODE_SERVFAIL); 991 iq->qchase.qname = sname; 992 iq->qchase.qname_len = slen; 993 /* This *is* a query restart, even if it is a cheap 994 * one. */ 995 iq->dp = NULL; 996 iq->refetch_glue = 0; 997 iq->query_restart_count++; 998 iq->sent_count = 0; 999 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1000 return next_state(iq, INIT_REQUEST_STATE); 1001 } 1002 1003 /* if from cache, NULL, else insert 'cache IP' len=0 */ 1004 if(qstate->reply_origin) 1005 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1006 /* it is an answer, response, to final state */ 1007 verbose(VERB_ALGO, "returning answer from cache."); 1008 iq->response = msg; 1009 return final_state(iq); 1010 } 1011 1012 /* attempt to forward the request */ 1013 if(forward_request(qstate, iq)) 1014 { 1015 if(!iq->dp) { 1016 log_err("alloc failure for forward dp"); 1017 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1018 } 1019 iq->refetch_glue = 0; 1020 /* the request has been forwarded. 1021 * forwarded requests need to be immediately sent to the 1022 * next state, QUERYTARGETS. */ 1023 return next_state(iq, QUERYTARGETS_STATE); 1024 } 1025 1026 /* Resolver Algorithm Step 2 -- find the "best" servers. */ 1027 1028 /* first, adjust for DS queries. To avoid the grandparent problem, 1029 * we just look for the closest set of server to the parent of qname. 1030 * When re-fetching glue we also need to ask the parent. 1031 */ 1032 if(iq->refetch_glue) { 1033 if(!iq->dp) { 1034 log_err("internal or malloc fail: no dp for refetch"); 1035 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1036 } 1037 delname = iq->dp->name; 1038 delnamelen = iq->dp->namelen; 1039 } else { 1040 delname = iq->qchase.qname; 1041 delnamelen = iq->qchase.qname_len; 1042 } 1043 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue || 1044 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) { 1045 /* remove first label from delname, root goes to hints, 1046 * but only to fetch glue, not for qtype=DS. */ 1047 /* also when prefetching an NS record, fetch it again from 1048 * its parent, just as if it expired, so that you do not 1049 * get stuck on an older nameserver that gives old NSrecords */ 1050 if(dname_is_root(delname) && (iq->refetch_glue || 1051 (iq->qchase.qtype == LDNS_RR_TYPE_NS && 1052 qstate->prefetch_leeway))) 1053 delname = NULL; /* go to root priming */ 1054 else dname_remove_label(&delname, &delnamelen); 1055 } 1056 /* delname is the name to lookup a delegation for. If NULL rootprime */ 1057 while(1) { 1058 1059 /* Lookup the delegation in the cache. If null, then the 1060 * cache needs to be primed for the qclass. */ 1061 if(delname) 1062 iq->dp = dns_cache_find_delegation(qstate->env, delname, 1063 delnamelen, iq->qchase.qtype, iq->qchase.qclass, 1064 qstate->region, &iq->deleg_msg, 1065 *qstate->env->now+qstate->prefetch_leeway); 1066 else iq->dp = NULL; 1067 1068 /* If the cache has returned nothing, then we have a 1069 * root priming situation. */ 1070 if(iq->dp == NULL) { 1071 /* if there is a stub, then no root prime needed */ 1072 int r = prime_stub(qstate, iq, id, delname, 1073 iq->qchase.qclass); 1074 if(r == 2) 1075 break; /* got noprime-stub-zone, continue */ 1076 else if(r) 1077 return 0; /* stub prime request made */ 1078 if(forwards_lookup_root(qstate->env->fwds, 1079 iq->qchase.qclass)) { 1080 /* forward zone root, no root prime needed */ 1081 /* fill in some dp - safety belt */ 1082 iq->dp = hints_lookup_root(qstate->env->hints, 1083 iq->qchase.qclass); 1084 if(!iq->dp) { 1085 log_err("internal error: no hints dp"); 1086 return error_response(qstate, id, 1087 LDNS_RCODE_SERVFAIL); 1088 } 1089 iq->dp = delegpt_copy(iq->dp, qstate->region); 1090 if(!iq->dp) { 1091 log_err("out of memory in safety belt"); 1092 return error_response(qstate, id, 1093 LDNS_RCODE_SERVFAIL); 1094 } 1095 return next_state(iq, INIT_REQUEST_2_STATE); 1096 } 1097 /* Note that the result of this will set a new 1098 * DelegationPoint based on the result of priming. */ 1099 if(!prime_root(qstate, iq, id, iq->qchase.qclass)) 1100 return error_response(qstate, id, 1101 LDNS_RCODE_REFUSED); 1102 1103 /* priming creates and sends a subordinate query, with 1104 * this query as the parent. So further processing for 1105 * this event will stop until reactivated by the 1106 * results of priming. */ 1107 return 0; 1108 } 1109 1110 /* see if this dp not useless. 1111 * It is useless if: 1112 * o all NS items are required glue. 1113 * or the query is for NS item that is required glue. 1114 * o no addresses are provided. 1115 * o RD qflag is on. 1116 * Instead, go up one level, and try to get even further 1117 * If the root was useless, use safety belt information. 1118 * Only check cache returns, because replies for servers 1119 * could be useless but lead to loops (bumping into the 1120 * same server reply) if useless-checked. 1121 */ 1122 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, 1123 iq->dp)) { 1124 if(dname_is_root(iq->dp->name)) { 1125 /* use safety belt */ 1126 verbose(VERB_QUERY, "Cache has root NS but " 1127 "no addresses. Fallback to the safety belt."); 1128 iq->dp = hints_lookup_root(qstate->env->hints, 1129 iq->qchase.qclass); 1130 /* note deleg_msg is from previous lookup, 1131 * but RD is on, so it is not used */ 1132 if(!iq->dp) { 1133 log_err("internal error: no hints dp"); 1134 return error_response(qstate, id, 1135 LDNS_RCODE_REFUSED); 1136 } 1137 iq->dp = delegpt_copy(iq->dp, qstate->region); 1138 if(!iq->dp) { 1139 log_err("out of memory in safety belt"); 1140 return error_response(qstate, id, 1141 LDNS_RCODE_SERVFAIL); 1142 } 1143 break; 1144 } else { 1145 verbose(VERB_ALGO, 1146 "cache delegation was useless:"); 1147 delegpt_log(VERB_ALGO, iq->dp); 1148 /* go up */ 1149 delname = iq->dp->name; 1150 delnamelen = iq->dp->namelen; 1151 dname_remove_label(&delname, &delnamelen); 1152 } 1153 } else break; 1154 } 1155 1156 verbose(VERB_ALGO, "cache delegation returns delegpt"); 1157 delegpt_log(VERB_ALGO, iq->dp); 1158 1159 /* Otherwise, set the current delegation point and move on to the 1160 * next state. */ 1161 return next_state(iq, INIT_REQUEST_2_STATE); 1162} 1163 1164/** 1165 * Process the second part of the initial request handling. This state 1166 * basically exists so that queries that generate root priming events have 1167 * the same init processing as ones that do not. Request events that reach 1168 * this state must have a valid currentDelegationPoint set. 1169 * 1170 * This part is primarly handling stub zone priming. Events that reach this 1171 * state must have a current delegation point. 1172 * 1173 * @param qstate: query state. 1174 * @param iq: iterator query state. 1175 * @param id: module id. 1176 * @return true if the event needs more request processing immediately, 1177 * false if not. 1178 */ 1179static int 1180processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq, 1181 int id) 1182{ 1183 uint8_t* delname; 1184 size_t delnamelen; 1185 log_query_info(VERB_QUERY, "resolving (init part 2): ", 1186 &qstate->qinfo); 1187 1188 if(iq->refetch_glue) { 1189 if(!iq->dp) { 1190 log_err("internal or malloc fail: no dp for refetch"); 1191 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1192 } 1193 delname = iq->dp->name; 1194 delnamelen = iq->dp->namelen; 1195 } else { 1196 delname = iq->qchase.qname; 1197 delnamelen = iq->qchase.qname_len; 1198 } 1199 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) { 1200 if(!dname_is_root(delname)) 1201 dname_remove_label(&delname, &delnamelen); 1202 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */ 1203 } 1204 /* Check to see if we need to prime a stub zone. */ 1205 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) { 1206 /* A priming sub request was made */ 1207 return 0; 1208 } 1209 1210 /* most events just get forwarded to the next state. */ 1211 return next_state(iq, INIT_REQUEST_3_STATE); 1212} 1213 1214/** 1215 * Process the third part of the initial request handling. This state exists 1216 * as a separate state so that queries that generate stub priming events 1217 * will get the tail end of the init process but not repeat the stub priming 1218 * check. 1219 * 1220 * @param qstate: query state. 1221 * @param iq: iterator query state. 1222 * @param id: module id. 1223 * @return true, advancing the event to the QUERYTARGETS_STATE. 1224 */ 1225static int 1226processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq, 1227 int id) 1228{ 1229 log_query_info(VERB_QUERY, "resolving (init part 3): ", 1230 &qstate->qinfo); 1231 /* if the cache reply dp equals a validation anchor or msg has DS, 1232 * then DNSSEC RRSIGs are expected in the reply */ 1233 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp, 1234 iq->deleg_msg, iq->qchase.qclass); 1235 1236 /* If the RD flag wasn't set, then we just finish with the 1237 * cached referral as the response. */ 1238 if(!(qstate->query_flags & BIT_RD)) { 1239 iq->response = iq->deleg_msg; 1240 if(verbosity >= VERB_ALGO) 1241 log_dns_msg("no RD requested, using delegation msg", 1242 &iq->response->qinfo, iq->response->rep); 1243 if(qstate->reply_origin) 1244 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1245 return final_state(iq); 1246 } 1247 /* After this point, unset the RD flag -- this query is going to 1248 * be sent to an auth. server. */ 1249 iq->chase_flags &= ~BIT_RD; 1250 1251 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */ 1252 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 1253 !(qstate->query_flags&BIT_CD)) { 1254 generate_dnskey_prefetch(qstate, iq, id); 1255 fptr_ok(fptr_whitelist_modenv_detach_subs( 1256 qstate->env->detach_subs)); 1257 (*qstate->env->detach_subs)(qstate); 1258 } 1259 1260 /* Jump to the next state. */ 1261 return next_state(iq, QUERYTARGETS_STATE); 1262} 1263 1264/** 1265 * Given a basic query, generate a parent-side "target" query. 1266 * These are subordinate queries for missing delegation point target addresses, 1267 * for which only the parent of the delegation provides correct IP addresses. 1268 * 1269 * @param qstate: query state. 1270 * @param iq: iterator query state. 1271 * @param id: module id. 1272 * @param name: target qname. 1273 * @param namelen: target qname length. 1274 * @param qtype: target qtype (either A or AAAA). 1275 * @param qclass: target qclass. 1276 * @return true on success, false on failure. 1277 */ 1278static int 1279generate_parentside_target_query(struct module_qstate* qstate, 1280 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen, 1281 uint16_t qtype, uint16_t qclass) 1282{ 1283 struct module_qstate* subq; 1284 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1285 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1286 return 0; 1287 if(subq) { 1288 struct iter_qstate* subiq = 1289 (struct iter_qstate*)subq->minfo[id]; 1290 /* blacklist the cache - we want to fetch parent stuff */ 1291 sock_list_insert(&subq->blacklist, NULL, 0, subq->region); 1292 subiq->query_for_pside_glue = 1; 1293 if(dname_subdomain_c(name, iq->dp->name)) { 1294 subiq->dp = delegpt_copy(iq->dp, subq->region); 1295 subiq->dnssec_expected = iter_indicates_dnssec( 1296 qstate->env, subiq->dp, NULL, 1297 subq->qinfo.qclass); 1298 subiq->refetch_glue = 1; 1299 } else { 1300 subiq->dp = dns_cache_find_delegation(qstate->env, 1301 name, namelen, qtype, qclass, subq->region, 1302 &subiq->deleg_msg, 1303 *qstate->env->now+subq->prefetch_leeway); 1304 /* if no dp, then it's from root, refetch unneeded */ 1305 if(subiq->dp) { 1306 subiq->dnssec_expected = iter_indicates_dnssec( 1307 qstate->env, subiq->dp, NULL, 1308 subq->qinfo.qclass); 1309 subiq->refetch_glue = 1; 1310 } 1311 } 1312 } 1313 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass); 1314 return 1; 1315} 1316 1317/** 1318 * Given a basic query, generate a "target" query. These are subordinate 1319 * queries for missing delegation point target addresses. 1320 * 1321 * @param qstate: query state. 1322 * @param iq: iterator query state. 1323 * @param id: module id. 1324 * @param name: target qname. 1325 * @param namelen: target qname length. 1326 * @param qtype: target qtype (either A or AAAA). 1327 * @param qclass: target qclass. 1328 * @return true on success, false on failure. 1329 */ 1330static int 1331generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq, 1332 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass) 1333{ 1334 struct module_qstate* subq; 1335 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1336 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1337 return 0; 1338 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass); 1339 return 1; 1340} 1341 1342/** 1343 * Given an event at a certain state, generate zero or more target queries 1344 * for it's current delegation point. 1345 * 1346 * @param qstate: query state. 1347 * @param iq: iterator query state. 1348 * @param ie: iterator shared global environment. 1349 * @param id: module id. 1350 * @param maxtargets: The maximum number of targets to query for. 1351 * if it is negative, there is no maximum number of targets. 1352 * @param num: returns the number of queries generated and processed, 1353 * which may be zero if there were no missing targets. 1354 * @return false on error. 1355 */ 1356static int 1357query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq, 1358 struct iter_env* ie, int id, int maxtargets, int* num) 1359{ 1360 int query_count = 0; 1361 struct delegpt_ns* ns; 1362 int missing; 1363 int toget = 0; 1364 1365 if(iq->depth == ie->max_dependency_depth) 1366 return 0; 1367 if(iq->depth > 0 && iq->target_count && 1368 iq->target_count[1] > MAX_TARGET_COUNT) { 1369 verbose(VERB_QUERY, "request has exceeded the maximum " 1370 "number of glue fetches %d", iq->target_count[1]); 1371 return 0; 1372 } 1373 1374 iter_mark_cycle_targets(qstate, iq->dp); 1375 missing = (int)delegpt_count_missing_targets(iq->dp); 1376 log_assert(maxtargets != 0); /* that would not be useful */ 1377 1378 /* Generate target requests. Basically, any missing targets 1379 * are queried for here, regardless if it is necessary to do 1380 * so to continue processing. */ 1381 if(maxtargets < 0 || maxtargets > missing) 1382 toget = missing; 1383 else toget = maxtargets; 1384 if(toget == 0) { 1385 *num = 0; 1386 return 1; 1387 } 1388 /* select 'toget' items from the total of 'missing' items */ 1389 log_assert(toget <= missing); 1390 1391 /* loop over missing targets */ 1392 for(ns = iq->dp->nslist; ns; ns = ns->next) { 1393 if(ns->resolved) 1394 continue; 1395 1396 /* randomly select this item with probability toget/missing */ 1397 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) { 1398 /* do not select this one, next; select toget number 1399 * of items from a list one less in size */ 1400 missing --; 1401 continue; 1402 } 1403 1404 if(ie->supports_ipv6 && !ns->got6) { 1405 /* Send the AAAA request. */ 1406 if(!generate_target_query(qstate, iq, id, 1407 ns->name, ns->namelen, 1408 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { 1409 *num = query_count; 1410 if(query_count > 0) 1411 qstate->ext_state[id] = module_wait_subquery; 1412 return 0; 1413 } 1414 query_count++; 1415 } 1416 /* Send the A request. */ 1417 if(ie->supports_ipv4 && !ns->got4) { 1418 if(!generate_target_query(qstate, iq, id, 1419 ns->name, ns->namelen, 1420 LDNS_RR_TYPE_A, iq->qchase.qclass)) { 1421 *num = query_count; 1422 if(query_count > 0) 1423 qstate->ext_state[id] = module_wait_subquery; 1424 return 0; 1425 } 1426 query_count++; 1427 } 1428 1429 /* mark this target as in progress. */ 1430 ns->resolved = 1; 1431 missing--; 1432 toget--; 1433 if(toget == 0) 1434 break; 1435 } 1436 *num = query_count; 1437 if(query_count > 0) 1438 qstate->ext_state[id] = module_wait_subquery; 1439 1440 return 1; 1441} 1442 1443/** 1444 * Called by processQueryTargets when it would like extra targets to query 1445 * but it seems to be out of options. At last resort some less appealing 1446 * options are explored. If there are no more options, the result is SERVFAIL 1447 * 1448 * @param qstate: query state. 1449 * @param iq: iterator query state. 1450 * @param ie: iterator shared global environment. 1451 * @param id: module id. 1452 * @return true if the event requires more request processing immediately, 1453 * false if not. 1454 */ 1455static int 1456processLastResort(struct module_qstate* qstate, struct iter_qstate* iq, 1457 struct iter_env* ie, int id) 1458{ 1459 struct delegpt_ns* ns; 1460 int query_count = 0; 1461 verbose(VERB_ALGO, "No more query targets, attempting last resort"); 1462 log_assert(iq->dp); 1463 1464 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) { 1465 struct delegpt* p = hints_lookup_root(qstate->env->hints, 1466 iq->qchase.qclass); 1467 if(p) { 1468 struct delegpt_ns* ns; 1469 struct delegpt_addr* a; 1470 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1471 for(ns = p->nslist; ns; ns=ns->next) { 1472 (void)delegpt_add_ns(iq->dp, qstate->region, 1473 ns->name, (int)ns->lame); 1474 } 1475 for(a = p->target_list; a; a=a->next_target) { 1476 (void)delegpt_add_addr(iq->dp, qstate->region, 1477 &a->addr, a->addrlen, a->bogus, 1478 a->lame); 1479 } 1480 } 1481 iq->dp->has_parent_side_NS = 1; 1482 } else if(!iq->dp->has_parent_side_NS) { 1483 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp, 1484 qstate->region, &qstate->qinfo) 1485 || !iq->dp->has_parent_side_NS) { 1486 /* if: malloc failure in lookup go up to try */ 1487 /* if: no parent NS in cache - go up one level */ 1488 verbose(VERB_ALGO, "try to grab parent NS"); 1489 iq->store_parent_NS = iq->dp; 1490 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1491 iq->deleg_msg = NULL; 1492 iq->refetch_glue = 1; 1493 iq->query_restart_count++; 1494 iq->sent_count = 0; 1495 return next_state(iq, INIT_REQUEST_STATE); 1496 } 1497 } 1498 /* see if that makes new names available */ 1499 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 1500 qstate->region, iq->dp)) 1501 log_err("out of memory in cache_fill_missing"); 1502 if(iq->dp->usable_list) { 1503 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache"); 1504 return next_state(iq, QUERYTARGETS_STATE); 1505 } 1506 /* try to fill out parent glue from cache */ 1507 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp, 1508 qstate->region, &qstate->qinfo)) { 1509 /* got parent stuff from cache, see if we can continue */ 1510 verbose(VERB_ALGO, "try parent-side glue from cache"); 1511 return next_state(iq, QUERYTARGETS_STATE); 1512 } 1513 /* query for an extra name added by the parent-NS record */ 1514 if(delegpt_count_missing_targets(iq->dp) > 0) { 1515 int qs = 0; 1516 verbose(VERB_ALGO, "try parent-side target name"); 1517 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) { 1518 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1519 } 1520 iq->num_target_queries += qs; 1521 target_count_increase(iq, qs); 1522 if(qs != 0) { 1523 qstate->ext_state[id] = module_wait_subquery; 1524 return 0; /* and wait for them */ 1525 } 1526 } 1527 if(iq->depth == ie->max_dependency_depth) { 1528 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail"); 1529 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1530 } 1531 if(iq->depth > 0 && iq->target_count && 1532 iq->target_count[1] > MAX_TARGET_COUNT) { 1533 verbose(VERB_QUERY, "request has exceeded the maximum " 1534 "number of glue fetches %d", iq->target_count[1]); 1535 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1536 } 1537 /* mark cycle targets for parent-side lookups */ 1538 iter_mark_pside_cycle_targets(qstate, iq->dp); 1539 /* see if we can issue queries to get nameserver addresses */ 1540 /* this lookup is not randomized, but sequential. */ 1541 for(ns = iq->dp->nslist; ns; ns = ns->next) { 1542 /* query for parent-side A and AAAA for nameservers */ 1543 if(ie->supports_ipv6 && !ns->done_pside6) { 1544 /* Send the AAAA request. */ 1545 if(!generate_parentside_target_query(qstate, iq, id, 1546 ns->name, ns->namelen, 1547 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) 1548 return error_response(qstate, id, 1549 LDNS_RCODE_SERVFAIL); 1550 ns->done_pside6 = 1; 1551 query_count++; 1552 } 1553 if(ie->supports_ipv4 && !ns->done_pside4) { 1554 /* Send the A request. */ 1555 if(!generate_parentside_target_query(qstate, iq, id, 1556 ns->name, ns->namelen, 1557 LDNS_RR_TYPE_A, iq->qchase.qclass)) 1558 return error_response(qstate, id, 1559 LDNS_RCODE_SERVFAIL); 1560 ns->done_pside4 = 1; 1561 query_count++; 1562 } 1563 if(query_count != 0) { /* suspend to await results */ 1564 verbose(VERB_ALGO, "try parent-side glue lookup"); 1565 iq->num_target_queries += query_count; 1566 target_count_increase(iq, query_count); 1567 qstate->ext_state[id] = module_wait_subquery; 1568 return 0; 1569 } 1570 } 1571 1572 /* if this was a parent-side glue query itself, then store that 1573 * failure in cache. */ 1574 if(iq->query_for_pside_glue && !iq->pside_glue) 1575 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 1576 iq->deleg_msg?iq->deleg_msg->rep: 1577 (iq->response?iq->response->rep:NULL)); 1578 1579 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL"); 1580 /* fail -- no more targets, no more hope of targets, no hope 1581 * of a response. */ 1582 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1583} 1584 1585/** 1586 * Try to find the NS record set that will resolve a qtype DS query. Due 1587 * to grandparent/grandchild reasons we did not get a proper lookup right 1588 * away. We need to create type NS queries until we get the right parent 1589 * for this lookup. We remove labels from the query to find the right point. 1590 * If we end up at the old dp name, then there is no solution. 1591 * 1592 * @param qstate: query state. 1593 * @param iq: iterator query state. 1594 * @param id: module id. 1595 * @return true if the event requires more immediate processing, false if 1596 * not. This is generally only true when forwarding the request to 1597 * the final state (i.e., on answer). 1598 */ 1599static int 1600processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id) 1601{ 1602 struct module_qstate* subq = NULL; 1603 verbose(VERB_ALGO, "processDSNSFind"); 1604 1605 if(!iq->dsns_point) { 1606 /* initialize */ 1607 iq->dsns_point = iq->qchase.qname; 1608 iq->dsns_point_len = iq->qchase.qname_len; 1609 } 1610 /* robustcheck for internal error: we are not underneath the dp */ 1611 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) { 1612 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1613 } 1614 1615 /* go up one (more) step, until we hit the dp, if so, end */ 1616 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len); 1617 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) { 1618 /* there was no inbetween nameserver, use the old delegation 1619 * point again. And this time, because dsns_point is nonNULL 1620 * we are going to accept the (bad) result */ 1621 iq->state = QUERYTARGETS_STATE; 1622 return 1; 1623 } 1624 iq->state = DSNS_FIND_STATE; 1625 1626 /* spawn NS lookup (validation not needed, this is for DS lookup) */ 1627 log_nametypeclass(VERB_ALGO, "fetch nameservers", 1628 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass); 1629 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len, 1630 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 1631 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 1632 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1633 } 1634 1635 return 0; 1636} 1637 1638/** 1639 * This is the request event state where the request will be sent to one of 1640 * its current query targets. This state also handles issuing target lookup 1641 * queries for missing target IP addresses. Queries typically iterate on 1642 * this state, both when they are just trying different targets for a given 1643 * delegation point, and when they change delegation points. This state 1644 * roughly corresponds to RFC 1034 algorithm steps 3 and 4. 1645 * 1646 * @param qstate: query state. 1647 * @param iq: iterator query state. 1648 * @param ie: iterator shared global environment. 1649 * @param id: module id. 1650 * @return true if the event requires more request processing immediately, 1651 * false if not. This state only returns true when it is generating 1652 * a SERVFAIL response because the query has hit a dead end. 1653 */ 1654static int 1655processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq, 1656 struct iter_env* ie, int id) 1657{ 1658 int tf_policy; 1659 struct delegpt_addr* target; 1660 struct outbound_entry* outq; 1661 1662 /* NOTE: a request will encounter this state for each target it 1663 * needs to send a query to. That is, at least one per referral, 1664 * more if some targets timeout or return throwaway answers. */ 1665 1666 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo); 1667 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, " 1668 "currentqueries %d sentcount %d", iq->num_target_queries, 1669 iq->num_current_queries, iq->sent_count); 1670 1671 /* Make sure that we haven't run away */ 1672 /* FIXME: is this check even necessary? */ 1673 if(iq->referral_count > MAX_REFERRAL_COUNT) { 1674 verbose(VERB_QUERY, "request has exceeded the maximum " 1675 "number of referrrals with %d", iq->referral_count); 1676 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1677 } 1678 if(iq->sent_count > MAX_SENT_COUNT) { 1679 verbose(VERB_QUERY, "request has exceeded the maximum " 1680 "number of sends with %d", iq->sent_count); 1681 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1682 } 1683 1684 /* Make sure we have a delegation point, otherwise priming failed 1685 * or another failure occurred */ 1686 if(!iq->dp) { 1687 verbose(VERB_QUERY, "Failed to get a delegation, giving up"); 1688 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1689 } 1690 if(!ie->supports_ipv6) 1691 delegpt_no_ipv6(iq->dp); 1692 if(!ie->supports_ipv4) 1693 delegpt_no_ipv4(iq->dp); 1694 delegpt_log(VERB_ALGO, iq->dp); 1695 1696 if(iq->num_current_queries>0) { 1697 /* already busy answering a query, this restart is because 1698 * more delegpt addrs became available, wait for existing 1699 * query. */ 1700 verbose(VERB_ALGO, "woke up, but wait for outstanding query"); 1701 qstate->ext_state[id] = module_wait_reply; 1702 return 0; 1703 } 1704 1705 tf_policy = 0; 1706 /* < not <=, because although the array is large enough for <=, the 1707 * generated query will immediately be discarded due to depth and 1708 * that servfail is cached, which is not good as opportunism goes. */ 1709 if(iq->depth < ie->max_dependency_depth 1710 && iq->sent_count < TARGET_FETCH_STOP) { 1711 tf_policy = ie->target_fetch_policy[iq->depth]; 1712 } 1713 1714 /* if in 0x20 fallback get as many targets as possible */ 1715 if(iq->caps_fallback) { 1716 int extra = 0; 1717 size_t naddr, nres, navail; 1718 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) { 1719 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1720 } 1721 iq->num_target_queries += extra; 1722 target_count_increase(iq, extra); 1723 if(iq->num_target_queries > 0) { 1724 /* wait to get all targets, we want to try em */ 1725 verbose(VERB_ALGO, "wait for all targets for fallback"); 1726 qstate->ext_state[id] = module_wait_reply; 1727 return 0; 1728 } 1729 /* did we do enough fallback queries already? */ 1730 delegpt_count_addr(iq->dp, &naddr, &nres, &navail); 1731 /* the current caps_server is the number of fallbacks sent. 1732 * the original query is one that matched too, so we have 1733 * caps_server+1 number of matching queries now */ 1734 if(iq->caps_server+1 >= naddr*3 || 1735 iq->caps_server+1 >= MAX_SENT_COUNT) { 1736 /* we're done, process the response */ 1737 verbose(VERB_ALGO, "0x20 fallback had %d responses " 1738 "match for %d wanted, done.", 1739 (int)iq->caps_server+1, (int)naddr*3); 1740 iq->caps_fallback = 0; 1741 iter_dec_attempts(iq->dp, 3); /* space for fallback */ 1742 iq->num_current_queries++; /* RespState decrements it*/ 1743 iq->referral_count++; /* make sure we don't loop */ 1744 iq->sent_count = 0; 1745 iq->state = QUERY_RESP_STATE; 1746 return 1; 1747 } 1748 verbose(VERB_ALGO, "0x20 fallback number %d", 1749 (int)iq->caps_server); 1750 1751 /* if there is a policy to fetch missing targets 1752 * opportunistically, do it. we rely on the fact that once a 1753 * query (or queries) for a missing name have been issued, 1754 * they will not show up again. */ 1755 } else if(tf_policy != 0) { 1756 int extra = 0; 1757 verbose(VERB_ALGO, "attempt to get extra %d targets", 1758 tf_policy); 1759 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra); 1760 /* errors ignored, these targets are not strictly necessary for 1761 * this result, we do not have to reply with SERVFAIL */ 1762 iq->num_target_queries += extra; 1763 target_count_increase(iq, extra); 1764 } 1765 1766 /* Add the current set of unused targets to our queue. */ 1767 delegpt_add_unused_targets(iq->dp); 1768 1769 /* Select the next usable target, filtering out unsuitable targets. */ 1770 target = iter_server_selection(ie, qstate->env, iq->dp, 1771 iq->dp->name, iq->dp->namelen, iq->qchase.qtype, 1772 &iq->dnssec_lame_query, &iq->chase_to_rd, 1773 iq->num_target_queries, qstate->blacklist); 1774 1775 /* If no usable target was selected... */ 1776 if(!target) { 1777 /* Here we distinguish between three states: generate a new 1778 * target query, just wait, or quit (with a SERVFAIL). 1779 * We have the following information: number of active 1780 * target queries, number of active current queries, 1781 * the presence of missing targets at this delegation 1782 * point, and the given query target policy. */ 1783 1784 /* Check for the wait condition. If this is true, then 1785 * an action must be taken. */ 1786 if(iq->num_target_queries==0 && iq->num_current_queries==0) { 1787 /* If there is nothing to wait for, then we need 1788 * to distinguish between generating (a) new target 1789 * query, or failing. */ 1790 if(delegpt_count_missing_targets(iq->dp) > 0) { 1791 int qs = 0; 1792 verbose(VERB_ALGO, "querying for next " 1793 "missing target"); 1794 if(!query_for_targets(qstate, iq, ie, id, 1795 1, &qs)) { 1796 return error_response(qstate, id, 1797 LDNS_RCODE_SERVFAIL); 1798 } 1799 if(qs == 0 && 1800 delegpt_count_missing_targets(iq->dp) == 0){ 1801 /* it looked like there were missing 1802 * targets, but they did not turn up. 1803 * Try the bad choices again (if any), 1804 * when we get back here missing==0, 1805 * so this is not a loop. */ 1806 return 1; 1807 } 1808 iq->num_target_queries += qs; 1809 target_count_increase(iq, qs); 1810 } 1811 /* Since a target query might have been made, we 1812 * need to check again. */ 1813 if(iq->num_target_queries == 0) { 1814 return processLastResort(qstate, iq, ie, id); 1815 } 1816 } 1817 1818 /* otherwise, we have no current targets, so submerge 1819 * until one of the target or direct queries return. */ 1820 if(iq->num_target_queries>0 && iq->num_current_queries>0) { 1821 verbose(VERB_ALGO, "no current targets -- waiting " 1822 "for %d targets to resolve or %d outstanding" 1823 " queries to respond", iq->num_target_queries, 1824 iq->num_current_queries); 1825 qstate->ext_state[id] = module_wait_reply; 1826 } else if(iq->num_target_queries>0) { 1827 verbose(VERB_ALGO, "no current targets -- waiting " 1828 "for %d targets to resolve.", 1829 iq->num_target_queries); 1830 qstate->ext_state[id] = module_wait_subquery; 1831 } else { 1832 verbose(VERB_ALGO, "no current targets -- waiting " 1833 "for %d outstanding queries to respond.", 1834 iq->num_current_queries); 1835 qstate->ext_state[id] = module_wait_reply; 1836 } 1837 return 0; 1838 } 1839 1840 /* We have a valid target. */ 1841 if(verbosity >= VERB_QUERY) { 1842 log_query_info(VERB_QUERY, "sending query:", &iq->qchase); 1843 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name, 1844 &target->addr, target->addrlen); 1845 verbose(VERB_ALGO, "dnssec status: %s%s", 1846 iq->dnssec_expected?"expected": "not expected", 1847 iq->dnssec_lame_query?" but lame_query anyway": ""); 1848 } 1849 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query)); 1850 outq = (*qstate->env->send_query)( 1851 iq->qchase.qname, iq->qchase.qname_len, 1852 iq->qchase.qtype, iq->qchase.qclass, 1853 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD, 1854 iq->dnssec_expected, &target->addr, target->addrlen, 1855 iq->dp->name, iq->dp->namelen, qstate); 1856 if(!outq) { 1857 log_addr(VERB_DETAIL, "error sending query to auth server", 1858 &target->addr, target->addrlen); 1859 return next_state(iq, QUERYTARGETS_STATE); 1860 } 1861 outbound_list_insert(&iq->outlist, outq); 1862 iq->num_current_queries++; 1863 iq->sent_count++; 1864 qstate->ext_state[id] = module_wait_reply; 1865 1866 return 0; 1867} 1868 1869/** find NS rrset in given list */ 1870static struct ub_packed_rrset_key* 1871find_NS(struct reply_info* rep, size_t from, size_t to) 1872{ 1873 size_t i; 1874 for(i=from; i<to; i++) { 1875 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) 1876 return rep->rrsets[i]; 1877 } 1878 return NULL; 1879} 1880 1881 1882/** 1883 * Process the query response. All queries end up at this state first. This 1884 * process generally consists of analyzing the response and routing the 1885 * event to the next state (either bouncing it back to a request state, or 1886 * terminating the processing for this event). 1887 * 1888 * @param qstate: query state. 1889 * @param iq: iterator query state. 1890 * @param id: module id. 1891 * @return true if the event requires more immediate processing, false if 1892 * not. This is generally only true when forwarding the request to 1893 * the final state (i.e., on answer). 1894 */ 1895static int 1896processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq, 1897 int id) 1898{ 1899 int dnsseclame = 0; 1900 enum response_type type; 1901 iq->num_current_queries--; 1902 if(iq->response == NULL) { 1903 iq->chase_to_rd = 0; 1904 iq->dnssec_lame_query = 0; 1905 verbose(VERB_ALGO, "query response was timeout"); 1906 return next_state(iq, QUERYTARGETS_STATE); 1907 } 1908 type = response_type_from_server( 1909 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 1910 iq->response, &iq->qchase, iq->dp); 1911 iq->chase_to_rd = 0; 1912 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) { 1913 /* When forwarding (RD bit is set), we handle referrals 1914 * differently. No queries should be sent elsewhere */ 1915 type = RESPONSE_TYPE_ANSWER; 1916 } 1917 if(iq->dnssec_expected && !iq->dnssec_lame_query && 1918 !(iq->chase_flags&BIT_RD) 1919 && type != RESPONSE_TYPE_LAME 1920 && type != RESPONSE_TYPE_REC_LAME 1921 && type != RESPONSE_TYPE_THROWAWAY 1922 && type != RESPONSE_TYPE_UNTYPED) { 1923 /* a possible answer, see if it is missing DNSSEC */ 1924 /* but not when forwarding, so we dont mark fwder lame */ 1925 /* also make sure the answer is from the zone we expected, 1926 * otherwise, (due to parent,child on same server), we 1927 * might mark the server,zone lame inappropriately */ 1928 if(!iter_msg_has_dnssec(iq->response) && 1929 iter_msg_from_zone(iq->response, iq->dp, type, 1930 iq->qchase.qclass)) { 1931 type = RESPONSE_TYPE_LAME; 1932 dnsseclame = 1; 1933 } 1934 } else iq->dnssec_lame_query = 0; 1935 /* see if referral brings us close to the target */ 1936 if(type == RESPONSE_TYPE_REFERRAL) { 1937 struct ub_packed_rrset_key* ns = find_NS( 1938 iq->response->rep, iq->response->rep->an_numrrsets, 1939 iq->response->rep->an_numrrsets 1940 + iq->response->rep->ns_numrrsets); 1941 if(!ns) ns = find_NS(iq->response->rep, 0, 1942 iq->response->rep->an_numrrsets); 1943 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name) 1944 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){ 1945 verbose(VERB_ALGO, "bad referral, throwaway"); 1946 type = RESPONSE_TYPE_THROWAWAY; 1947 } else 1948 iter_scrub_ds(iq->response, ns, iq->dp->name); 1949 } else iter_scrub_ds(iq->response, NULL, NULL); 1950 1951 /* handle each of the type cases */ 1952 if(type == RESPONSE_TYPE_ANSWER) { 1953 /* ANSWER type responses terminate the query algorithm, 1954 * so they sent on their */ 1955 if(verbosity >= VERB_DETAIL) { 1956 verbose(VERB_DETAIL, "query response was %s", 1957 FLAGS_GET_RCODE(iq->response->rep->flags) 1958 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER": 1959 (iq->response->rep->an_numrrsets?"ANSWER": 1960 "nodata ANSWER")); 1961 } 1962 /* if qtype is DS, check we have the right level of answer, 1963 * like grandchild answer but we need the middle, reject it */ 1964 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 1965 && !(iq->chase_flags&BIT_RD) 1966 && iter_ds_toolow(iq->response, iq->dp) 1967 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 1968 /* close down outstanding requests to be discarded */ 1969 outbound_list_clear(&iq->outlist); 1970 iq->num_current_queries = 0; 1971 fptr_ok(fptr_whitelist_modenv_detach_subs( 1972 qstate->env->detach_subs)); 1973 (*qstate->env->detach_subs)(qstate); 1974 iq->num_target_queries = 0; 1975 return processDSNSFind(qstate, iq, id); 1976 } 1977 iter_dns_store(qstate->env, &iq->response->qinfo, 1978 iq->response->rep, 0, qstate->prefetch_leeway, 1979 iq->dp&&iq->dp->has_parent_side_NS, 1980 qstate->region); 1981 /* close down outstanding requests to be discarded */ 1982 outbound_list_clear(&iq->outlist); 1983 iq->num_current_queries = 0; 1984 fptr_ok(fptr_whitelist_modenv_detach_subs( 1985 qstate->env->detach_subs)); 1986 (*qstate->env->detach_subs)(qstate); 1987 iq->num_target_queries = 0; 1988 if(qstate->reply) 1989 sock_list_insert(&qstate->reply_origin, 1990 &qstate->reply->addr, qstate->reply->addrlen, 1991 qstate->region); 1992 return final_state(iq); 1993 } else if(type == RESPONSE_TYPE_REFERRAL) { 1994 /* REFERRAL type responses get a reset of the 1995 * delegation point, and back to the QUERYTARGETS_STATE. */ 1996 verbose(VERB_DETAIL, "query response was REFERRAL"); 1997 1998 /* if hardened, only store referral if we asked for it */ 1999 if(!qstate->env->cfg->harden_referral_path || 2000 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS 2001 && (qstate->query_flags&BIT_RD) 2002 && !(qstate->query_flags&BIT_CD) 2003 /* we know that all other NS rrsets are scrubbed 2004 * away, thus on referral only one is left. 2005 * see if that equals the query name... */ 2006 && ( /* auth section, but sometimes in answer section*/ 2007 reply_find_rrset_section_ns(iq->response->rep, 2008 iq->qchase.qname, iq->qchase.qname_len, 2009 LDNS_RR_TYPE_NS, iq->qchase.qclass) 2010 || reply_find_rrset_section_an(iq->response->rep, 2011 iq->qchase.qname, iq->qchase.qname_len, 2012 LDNS_RR_TYPE_NS, iq->qchase.qclass) 2013 ) 2014 )) { 2015 /* Store the referral under the current query */ 2016 /* no prefetch-leeway, since its not the answer */ 2017 iter_dns_store(qstate->env, &iq->response->qinfo, 2018 iq->response->rep, 1, 0, 0, NULL); 2019 if(iq->store_parent_NS) 2020 iter_store_parentside_NS(qstate->env, 2021 iq->response->rep); 2022 if(qstate->env->neg_cache) 2023 val_neg_addreferral(qstate->env->neg_cache, 2024 iq->response->rep, iq->dp->name); 2025 } 2026 /* store parent-side-in-zone-glue, if directly queried for */ 2027 if(iq->query_for_pside_glue && !iq->pside_glue) { 2028 iq->pside_glue = reply_find_rrset(iq->response->rep, 2029 iq->qchase.qname, iq->qchase.qname_len, 2030 iq->qchase.qtype, iq->qchase.qclass); 2031 if(iq->pside_glue) { 2032 log_rrset_key(VERB_ALGO, "found parent-side " 2033 "glue", iq->pside_glue); 2034 iter_store_parentside_rrset(qstate->env, 2035 iq->pside_glue); 2036 } 2037 } 2038 2039 /* Reset the event state, setting the current delegation 2040 * point to the referral. */ 2041 iq->deleg_msg = iq->response; 2042 iq->dp = delegpt_from_message(iq->response, qstate->region); 2043 if(!iq->dp) 2044 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2045 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 2046 qstate->region, iq->dp)) 2047 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2048 if(iq->store_parent_NS && query_dname_compare(iq->dp->name, 2049 iq->store_parent_NS->name) == 0) 2050 iter_merge_retry_counts(iq->dp, iq->store_parent_NS); 2051 delegpt_log(VERB_ALGO, iq->dp); 2052 /* Count this as a referral. */ 2053 iq->referral_count++; 2054 iq->sent_count = 0; 2055 /* see if the next dp is a trust anchor, or a DS was sent 2056 * along, indicating dnssec is expected for next zone */ 2057 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, 2058 iq->dp, iq->response, iq->qchase.qclass); 2059 /* if dnssec, validating then also fetch the key for the DS */ 2060 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 2061 !(qstate->query_flags&BIT_CD)) 2062 generate_dnskey_prefetch(qstate, iq, id); 2063 2064 /* spawn off NS and addr to auth servers for the NS we just 2065 * got in the referral. This gets authoritative answer 2066 * (answer section trust level) rrset. 2067 * right after, we detach the subs, answer goes to cache. */ 2068 if(qstate->env->cfg->harden_referral_path) 2069 generate_ns_check(qstate, iq, id); 2070 2071 /* stop current outstanding queries. 2072 * FIXME: should the outstanding queries be waited for and 2073 * handled? Say by a subquery that inherits the outbound_entry. 2074 */ 2075 outbound_list_clear(&iq->outlist); 2076 iq->num_current_queries = 0; 2077 fptr_ok(fptr_whitelist_modenv_detach_subs( 2078 qstate->env->detach_subs)); 2079 (*qstate->env->detach_subs)(qstate); 2080 iq->num_target_queries = 0; 2081 verbose(VERB_ALGO, "cleared outbound list for next round"); 2082 return next_state(iq, QUERYTARGETS_STATE); 2083 } else if(type == RESPONSE_TYPE_CNAME) { 2084 uint8_t* sname = NULL; 2085 size_t snamelen = 0; 2086 /* CNAME type responses get a query restart (i.e., get a 2087 * reset of the query state and go back to INIT_REQUEST_STATE). 2088 */ 2089 verbose(VERB_DETAIL, "query response was CNAME"); 2090 if(verbosity >= VERB_ALGO) 2091 log_dns_msg("cname msg", &iq->response->qinfo, 2092 iq->response->rep); 2093 /* if qtype is DS, check we have the right level of answer, 2094 * like grandchild answer but we need the middle, reject it */ 2095 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 2096 && !(iq->chase_flags&BIT_RD) 2097 && iter_ds_toolow(iq->response, iq->dp) 2098 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 2099 outbound_list_clear(&iq->outlist); 2100 iq->num_current_queries = 0; 2101 fptr_ok(fptr_whitelist_modenv_detach_subs( 2102 qstate->env->detach_subs)); 2103 (*qstate->env->detach_subs)(qstate); 2104 iq->num_target_queries = 0; 2105 return processDSNSFind(qstate, iq, id); 2106 } 2107 /* Process the CNAME response. */ 2108 if(!handle_cname_response(qstate, iq, iq->response, 2109 &sname, &snamelen)) 2110 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2111 /* cache the CNAME response under the current query */ 2112 /* NOTE : set referral=1, so that rrsets get stored but not 2113 * the partial query answer (CNAME only). */ 2114 /* prefetchleeway applied because this updates answer parts */ 2115 iter_dns_store(qstate->env, &iq->response->qinfo, 2116 iq->response->rep, 1, qstate->prefetch_leeway, 2117 iq->dp&&iq->dp->has_parent_side_NS, NULL); 2118 /* set the current request's qname to the new value. */ 2119 iq->qchase.qname = sname; 2120 iq->qchase.qname_len = snamelen; 2121 /* Clear the query state, since this is a query restart. */ 2122 iq->deleg_msg = NULL; 2123 iq->dp = NULL; 2124 iq->dsns_point = NULL; 2125 /* Note the query restart. */ 2126 iq->query_restart_count++; 2127 iq->sent_count = 0; 2128 2129 /* stop current outstanding queries. 2130 * FIXME: should the outstanding queries be waited for and 2131 * handled? Say by a subquery that inherits the outbound_entry. 2132 */ 2133 outbound_list_clear(&iq->outlist); 2134 iq->num_current_queries = 0; 2135 fptr_ok(fptr_whitelist_modenv_detach_subs( 2136 qstate->env->detach_subs)); 2137 (*qstate->env->detach_subs)(qstate); 2138 iq->num_target_queries = 0; 2139 if(qstate->reply) 2140 sock_list_insert(&qstate->reply_origin, 2141 &qstate->reply->addr, qstate->reply->addrlen, 2142 qstate->region); 2143 verbose(VERB_ALGO, "cleared outbound list for query restart"); 2144 /* go to INIT_REQUEST_STATE for new qname. */ 2145 return next_state(iq, INIT_REQUEST_STATE); 2146 } else if(type == RESPONSE_TYPE_LAME) { 2147 /* Cache the LAMEness. */ 2148 verbose(VERB_DETAIL, "query response was %sLAME", 2149 dnsseclame?"DNSSEC ":""); 2150 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2151 log_err("mark lame: mismatch in qname and dpname"); 2152 /* throwaway this reply below */ 2153 } else if(qstate->reply) { 2154 /* need addr for lameness cache, but we may have 2155 * gotten this from cache, so test to be sure */ 2156 if(!infra_set_lame(qstate->env->infra_cache, 2157 &qstate->reply->addr, qstate->reply->addrlen, 2158 iq->dp->name, iq->dp->namelen, 2159 *qstate->env->now, dnsseclame, 0, 2160 iq->qchase.qtype)) 2161 log_err("mark host lame: out of memory"); 2162 } else log_err("%slame response from cache", 2163 dnsseclame?"DNSSEC ":""); 2164 } else if(type == RESPONSE_TYPE_REC_LAME) { 2165 /* Cache the LAMEness. */ 2166 verbose(VERB_DETAIL, "query response REC_LAME: " 2167 "recursive but not authoritative server"); 2168 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2169 log_err("mark rec_lame: mismatch in qname and dpname"); 2170 /* throwaway this reply below */ 2171 } else if(qstate->reply) { 2172 /* need addr for lameness cache, but we may have 2173 * gotten this from cache, so test to be sure */ 2174 verbose(VERB_DETAIL, "mark as REC_LAME"); 2175 if(!infra_set_lame(qstate->env->infra_cache, 2176 &qstate->reply->addr, qstate->reply->addrlen, 2177 iq->dp->name, iq->dp->namelen, 2178 *qstate->env->now, 0, 1, iq->qchase.qtype)) 2179 log_err("mark host lame: out of memory"); 2180 } 2181 } else if(type == RESPONSE_TYPE_THROWAWAY) { 2182 /* LAME and THROWAWAY responses are handled the same way. 2183 * In this case, the event is just sent directly back to 2184 * the QUERYTARGETS_STATE without resetting anything, 2185 * because, clearly, the next target must be tried. */ 2186 verbose(VERB_DETAIL, "query response was THROWAWAY"); 2187 } else { 2188 log_warn("A query response came back with an unknown type: %d", 2189 (int)type); 2190 } 2191 2192 /* LAME, THROWAWAY and "unknown" all end up here. 2193 * Recycle to the QUERYTARGETS state to hopefully try a 2194 * different target. */ 2195 return next_state(iq, QUERYTARGETS_STATE); 2196} 2197 2198/** 2199 * Return priming query results to interestes super querystates. 2200 * 2201 * Sets the delegation point and delegation message (not nonRD queries). 2202 * This is a callback from walk_supers. 2203 * 2204 * @param qstate: priming query state that finished. 2205 * @param id: module id. 2206 * @param forq: the qstate for which priming has been done. 2207 */ 2208static void 2209prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq) 2210{ 2211 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2212 struct delegpt* dp = NULL; 2213 2214 log_assert(qstate->is_priming || foriq->wait_priming_stub); 2215 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2216 /* Convert our response to a delegation point */ 2217 dp = delegpt_from_message(qstate->return_msg, forq->region); 2218 if(!dp) { 2219 /* if there is no convertable delegation point, then 2220 * the ANSWER type was (presumably) a negative answer. */ 2221 verbose(VERB_ALGO, "prime response was not a positive " 2222 "ANSWER; failing"); 2223 foriq->dp = NULL; 2224 foriq->state = QUERYTARGETS_STATE; 2225 return; 2226 } 2227 2228 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo); 2229 delegpt_log(VERB_ALGO, dp); 2230 foriq->dp = dp; 2231 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region); 2232 if(!foriq->deleg_msg) { 2233 log_err("copy prime response: out of memory"); 2234 foriq->dp = NULL; 2235 foriq->state = QUERYTARGETS_STATE; 2236 return; 2237 } 2238 2239 /* root priming responses go to init stage 2, priming stub 2240 * responses to to stage 3. */ 2241 if(foriq->wait_priming_stub) { 2242 foriq->state = INIT_REQUEST_3_STATE; 2243 foriq->wait_priming_stub = 0; 2244 } else foriq->state = INIT_REQUEST_2_STATE; 2245 /* because we are finished, the parent will be reactivated */ 2246} 2247 2248/** 2249 * This handles the response to a priming query. This is used to handle both 2250 * root and stub priming responses. This is basically the equivalent of the 2251 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat 2252 * REFERRALs as ANSWERS. It will also update and reactivate the originating 2253 * event. 2254 * 2255 * @param qstate: query state. 2256 * @param id: module id. 2257 * @return true if the event needs more immediate processing, false if not. 2258 * This state always returns false. 2259 */ 2260static int 2261processPrimeResponse(struct module_qstate* qstate, int id) 2262{ 2263 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2264 enum response_type type; 2265 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */ 2266 type = response_type_from_server( 2267 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 2268 iq->response, &iq->qchase, iq->dp); 2269 if(type == RESPONSE_TYPE_ANSWER) { 2270 qstate->return_rcode = LDNS_RCODE_NOERROR; 2271 qstate->return_msg = iq->response; 2272 } else { 2273 qstate->return_rcode = LDNS_RCODE_SERVFAIL; 2274 qstate->return_msg = NULL; 2275 } 2276 2277 /* validate the root or stub after priming (if enabled). 2278 * This is the same query as the prime query, but with validation. 2279 * Now that we are primed, the additional queries that validation 2280 * may need can be resolved, such as DLV. */ 2281 if(qstate->env->cfg->harden_referral_path) { 2282 struct module_qstate* subq = NULL; 2283 log_nametypeclass(VERB_ALGO, "schedule prime validation", 2284 qstate->qinfo.qname, qstate->qinfo.qtype, 2285 qstate->qinfo.qclass); 2286 if(!generate_sub_request(qstate->qinfo.qname, 2287 qstate->qinfo.qname_len, qstate->qinfo.qtype, 2288 qstate->qinfo.qclass, qstate, id, iq, 2289 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 2290 verbose(VERB_ALGO, "could not generate prime check"); 2291 } 2292 generate_a_aaaa_check(qstate, iq, id); 2293 } 2294 2295 /* This event is finished. */ 2296 qstate->ext_state[id] = module_finished; 2297 return 0; 2298} 2299 2300/** 2301 * Do final processing on responses to target queries. Events reach this 2302 * state after the iterative resolution algorithm terminates. This state is 2303 * responsible for reactiving the original event, and housekeeping related 2304 * to received target responses (caching, updating the current delegation 2305 * point, etc). 2306 * Callback from walk_supers for every super state that is interested in 2307 * the results from this query. 2308 * 2309 * @param qstate: query state. 2310 * @param id: module id. 2311 * @param forq: super query state. 2312 */ 2313static void 2314processTargetResponse(struct module_qstate* qstate, int id, 2315 struct module_qstate* forq) 2316{ 2317 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2318 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2319 struct ub_packed_rrset_key* rrset; 2320 struct delegpt_ns* dpns; 2321 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2322 2323 foriq->state = QUERYTARGETS_STATE; 2324 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo); 2325 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo); 2326 2327 /* check to see if parent event is still interested (in orig name). */ 2328 if(!foriq->dp) { 2329 verbose(VERB_ALGO, "subq: parent not interested, was reset"); 2330 return; /* not interested anymore */ 2331 } 2332 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname, 2333 qstate->qinfo.qname_len); 2334 if(!dpns) { 2335 /* If not interested, just stop processing this event */ 2336 verbose(VERB_ALGO, "subq: parent not interested anymore"); 2337 /* could be because parent was jostled out of the cache, 2338 and a new identical query arrived, that does not want it*/ 2339 return; 2340 } 2341 2342 /* Tell the originating event that this target query has finished 2343 * (regardless if it succeeded or not). */ 2344 foriq->num_target_queries--; 2345 2346 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */ 2347 if(iq->pside_glue) { 2348 /* if the pside_glue is NULL, then it could not be found, 2349 * the done_pside is already set when created and a cache 2350 * entry created in processFinished so nothing to do here */ 2351 log_rrset_key(VERB_ALGO, "add parentside glue to dp", 2352 iq->pside_glue); 2353 if(!delegpt_add_rrset(foriq->dp, forq->region, 2354 iq->pside_glue, 1)) 2355 log_err("out of memory adding pside glue"); 2356 } 2357 2358 /* This response is relevant to the current query, so we 2359 * add (attempt to add, anyway) this target(s) and reactivate 2360 * the original event. 2361 * NOTE: we could only look for the AnswerRRset if the 2362 * response type was ANSWER. */ 2363 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep); 2364 if(rrset) { 2365 /* if CNAMEs have been followed - add new NS to delegpt. */ 2366 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */ 2367 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname, 2368 rrset->rk.dname_len)) { 2369 /* if dpns->lame then set newcname ns lame too */ 2370 if(!delegpt_add_ns(foriq->dp, forq->region, 2371 rrset->rk.dname, (int)dpns->lame)) 2372 log_err("out of memory adding cnamed-ns"); 2373 } 2374 /* if dpns->lame then set the address(es) lame too */ 2375 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset, 2376 (int)dpns->lame)) 2377 log_err("out of memory adding targets"); 2378 verbose(VERB_ALGO, "added target response"); 2379 delegpt_log(VERB_ALGO, foriq->dp); 2380 } else { 2381 verbose(VERB_ALGO, "iterator TargetResponse failed"); 2382 dpns->resolved = 1; /* fail the target */ 2383 } 2384} 2385 2386/** 2387 * Process response for DS NS Find queries, that attempt to find the delegation 2388 * point where we ask the DS query from. 2389 * 2390 * @param qstate: query state. 2391 * @param id: module id. 2392 * @param forq: super query state. 2393 */ 2394static void 2395processDSNSResponse(struct module_qstate* qstate, int id, 2396 struct module_qstate* forq) 2397{ 2398 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2399 2400 /* if the finished (iq->response) query has no NS set: continue 2401 * up to look for the right dp; nothing to change, do DPNSstate */ 2402 if(qstate->return_rcode != LDNS_RCODE_NOERROR) 2403 return; /* seek further */ 2404 /* find the NS RRset (without allowing CNAMEs) */ 2405 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname, 2406 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS, 2407 qstate->qinfo.qclass)){ 2408 return; /* seek further */ 2409 } 2410 2411 /* else, store as DP and continue at querytargets */ 2412 foriq->state = QUERYTARGETS_STATE; 2413 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region); 2414 if(!foriq->dp) { 2415 log_err("out of memory in dsns dp alloc"); 2416 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */ 2417 } 2418 /* success, go query the querytargets in the new dp (and go down) */ 2419} 2420 2421/** 2422 * Process response for qclass=ANY queries for a particular class. 2423 * Append to result or error-exit. 2424 * 2425 * @param qstate: query state. 2426 * @param id: module id. 2427 * @param forq: super query state. 2428 */ 2429static void 2430processClassResponse(struct module_qstate* qstate, int id, 2431 struct module_qstate* forq) 2432{ 2433 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2434 struct dns_msg* from = qstate->return_msg; 2435 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo); 2436 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo); 2437 if(qstate->return_rcode != LDNS_RCODE_NOERROR) { 2438 /* cause servfail for qclass ANY query */ 2439 foriq->response = NULL; 2440 foriq->state = FINISHED_STATE; 2441 return; 2442 } 2443 /* append result */ 2444 if(!foriq->response) { 2445 /* allocate the response: copy RCODE, sec_state */ 2446 foriq->response = dns_copy_msg(from, forq->region); 2447 if(!foriq->response) { 2448 log_err("malloc failed for qclass ANY response"); 2449 foriq->state = FINISHED_STATE; 2450 return; 2451 } 2452 foriq->response->qinfo.qclass = forq->qinfo.qclass; 2453 /* qclass ANY does not receive the AA flag on replies */ 2454 foriq->response->rep->authoritative = 0; 2455 } else { 2456 struct dns_msg* to = foriq->response; 2457 /* add _from_ this response _to_ existing collection */ 2458 /* if there are records, copy RCODE */ 2459 /* lower sec_state if this message is lower */ 2460 if(from->rep->rrset_count != 0) { 2461 size_t n = from->rep->rrset_count+to->rep->rrset_count; 2462 struct ub_packed_rrset_key** dest, **d; 2463 /* copy appropriate rcode */ 2464 to->rep->flags = from->rep->flags; 2465 /* copy rrsets */ 2466 dest = regional_alloc(forq->region, sizeof(dest[0])*n); 2467 if(!dest) { 2468 log_err("malloc failed in collect ANY"); 2469 foriq->state = FINISHED_STATE; 2470 return; 2471 } 2472 d = dest; 2473 /* copy AN */ 2474 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets 2475 * sizeof(dest[0])); 2476 dest += to->rep->an_numrrsets; 2477 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets 2478 * sizeof(dest[0])); 2479 dest += from->rep->an_numrrsets; 2480 /* copy NS */ 2481 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets, 2482 to->rep->ns_numrrsets * sizeof(dest[0])); 2483 dest += to->rep->ns_numrrsets; 2484 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets, 2485 from->rep->ns_numrrsets * sizeof(dest[0])); 2486 dest += from->rep->ns_numrrsets; 2487 /* copy AR */ 2488 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+ 2489 to->rep->ns_numrrsets, 2490 to->rep->ar_numrrsets * sizeof(dest[0])); 2491 dest += to->rep->ar_numrrsets; 2492 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+ 2493 from->rep->ns_numrrsets, 2494 from->rep->ar_numrrsets * sizeof(dest[0])); 2495 /* update counts */ 2496 to->rep->rrsets = d; 2497 to->rep->an_numrrsets += from->rep->an_numrrsets; 2498 to->rep->ns_numrrsets += from->rep->ns_numrrsets; 2499 to->rep->ar_numrrsets += from->rep->ar_numrrsets; 2500 to->rep->rrset_count = n; 2501 } 2502 if(from->rep->security < to->rep->security) /* lowest sec */ 2503 to->rep->security = from->rep->security; 2504 if(from->rep->qdcount != 0) /* insert qd if appropriate */ 2505 to->rep->qdcount = from->rep->qdcount; 2506 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */ 2507 to->rep->ttl = from->rep->ttl; 2508 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl) 2509 to->rep->prefetch_ttl = from->rep->prefetch_ttl; 2510 } 2511 /* are we done? */ 2512 foriq->num_current_queries --; 2513 if(foriq->num_current_queries == 0) 2514 foriq->state = FINISHED_STATE; 2515} 2516 2517/** 2518 * Collect class ANY responses and make them into one response. This 2519 * state is started and it creates queries for all classes (that have 2520 * root hints). The answers are then collected. 2521 * 2522 * @param qstate: query state. 2523 * @param id: module id. 2524 * @return true if the event needs more immediate processing, false if not. 2525 */ 2526static int 2527processCollectClass(struct module_qstate* qstate, int id) 2528{ 2529 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2530 struct module_qstate* subq; 2531 /* If qchase.qclass == 0 then send out queries for all classes. 2532 * Otherwise, do nothing (wait for all answers to arrive and the 2533 * processClassResponse to put them together, and that moves us 2534 * towards the Finished state when done. */ 2535 if(iq->qchase.qclass == 0) { 2536 uint16_t c = 0; 2537 iq->qchase.qclass = LDNS_RR_CLASS_ANY; 2538 while(iter_get_next_root(qstate->env->hints, 2539 qstate->env->fwds, &c)) { 2540 /* generate query for this class */ 2541 log_nametypeclass(VERB_ALGO, "spawn collect query", 2542 qstate->qinfo.qname, qstate->qinfo.qtype, c); 2543 if(!generate_sub_request(qstate->qinfo.qname, 2544 qstate->qinfo.qname_len, qstate->qinfo.qtype, 2545 c, qstate, id, iq, INIT_REQUEST_STATE, 2546 FINISHED_STATE, &subq, 2547 (int)!(qstate->query_flags&BIT_CD))) { 2548 return error_response(qstate, id, 2549 LDNS_RCODE_SERVFAIL); 2550 } 2551 /* ignore subq, no special init required */ 2552 iq->num_current_queries ++; 2553 if(c == 0xffff) 2554 break; 2555 else c++; 2556 } 2557 /* if no roots are configured at all, return */ 2558 if(iq->num_current_queries == 0) { 2559 verbose(VERB_ALGO, "No root hints or fwds, giving up " 2560 "on qclass ANY"); 2561 return error_response(qstate, id, LDNS_RCODE_REFUSED); 2562 } 2563 /* return false, wait for queries to return */ 2564 } 2565 /* if woke up here because of an answer, wait for more answers */ 2566 return 0; 2567} 2568 2569/** 2570 * This handles the final state for first-tier responses (i.e., responses to 2571 * externally generated queries). 2572 * 2573 * @param qstate: query state. 2574 * @param iq: iterator query state. 2575 * @param id: module id. 2576 * @return true if the event needs more processing, false if not. Since this 2577 * is the final state for an event, it always returns false. 2578 */ 2579static int 2580processFinished(struct module_qstate* qstate, struct iter_qstate* iq, 2581 int id) 2582{ 2583 log_query_info(VERB_QUERY, "finishing processing for", 2584 &qstate->qinfo); 2585 2586 /* store negative cache element for parent side glue. */ 2587 if(iq->query_for_pside_glue && !iq->pside_glue) 2588 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 2589 iq->deleg_msg?iq->deleg_msg->rep: 2590 (iq->response?iq->response->rep:NULL)); 2591 if(!iq->response) { 2592 verbose(VERB_ALGO, "No response is set, servfail"); 2593 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2594 } 2595 2596 /* Make sure that the RA flag is set (since the presence of 2597 * this module means that recursion is available) */ 2598 iq->response->rep->flags |= BIT_RA; 2599 2600 /* Clear the AA flag */ 2601 /* FIXME: does this action go here or in some other module? */ 2602 iq->response->rep->flags &= ~BIT_AA; 2603 2604 /* make sure QR flag is on */ 2605 iq->response->rep->flags |= BIT_QR; 2606 2607 /* we have finished processing this query */ 2608 qstate->ext_state[id] = module_finished; 2609 2610 /* TODO: we are using a private TTL, trim the response. */ 2611 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */ 2612 2613 /* prepend any items we have accumulated */ 2614 if(iq->an_prepend_list || iq->ns_prepend_list) { 2615 if(!iter_prepend(iq, iq->response, qstate->region)) { 2616 log_err("prepend rrsets: out of memory"); 2617 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2618 } 2619 /* reset the query name back */ 2620 iq->response->qinfo = qstate->qinfo; 2621 /* the security state depends on the combination */ 2622 iq->response->rep->security = sec_status_unchecked; 2623 /* store message with the finished prepended items, 2624 * but only if we did recursion. The nonrecursion referral 2625 * from cache does not need to be stored in the msg cache. */ 2626 if(qstate->query_flags&BIT_RD) { 2627 iter_dns_store(qstate->env, &qstate->qinfo, 2628 iq->response->rep, 0, qstate->prefetch_leeway, 2629 iq->dp&&iq->dp->has_parent_side_NS, 2630 qstate->region); 2631 } 2632 } 2633 qstate->return_rcode = LDNS_RCODE_NOERROR; 2634 qstate->return_msg = iq->response; 2635 return 0; 2636} 2637 2638/* 2639 * Return priming query results to interestes super querystates. 2640 * 2641 * Sets the delegation point and delegation message (not nonRD queries). 2642 * This is a callback from walk_supers. 2643 * 2644 * @param qstate: query state that finished. 2645 * @param id: module id. 2646 * @param super: the qstate to inform. 2647 */ 2648void 2649iter_inform_super(struct module_qstate* qstate, int id, 2650 struct module_qstate* super) 2651{ 2652 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY) 2653 processClassResponse(qstate, id, super); 2654 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) 2655 super->minfo[id])->state == DSNS_FIND_STATE) 2656 processDSNSResponse(qstate, id, super); 2657 else if(qstate->return_rcode != LDNS_RCODE_NOERROR) 2658 error_supers(qstate, id, super); 2659 else if(qstate->is_priming) 2660 prime_supers(qstate, id, super); 2661 else processTargetResponse(qstate, id, super); 2662} 2663 2664/** 2665 * Handle iterator state. 2666 * Handle events. This is the real processing loop for events, responsible 2667 * for moving events through the various states. If a processing method 2668 * returns true, then it will be advanced to the next state. If false, then 2669 * processing will stop. 2670 * 2671 * @param qstate: query state. 2672 * @param ie: iterator shared global environment. 2673 * @param iq: iterator query state. 2674 * @param id: module id. 2675 */ 2676static void 2677iter_handle(struct module_qstate* qstate, struct iter_qstate* iq, 2678 struct iter_env* ie, int id) 2679{ 2680 int cont = 1; 2681 while(cont) { 2682 verbose(VERB_ALGO, "iter_handle processing q with state %s", 2683 iter_state_to_string(iq->state)); 2684 switch(iq->state) { 2685 case INIT_REQUEST_STATE: 2686 cont = processInitRequest(qstate, iq, ie, id); 2687 break; 2688 case INIT_REQUEST_2_STATE: 2689 cont = processInitRequest2(qstate, iq, id); 2690 break; 2691 case INIT_REQUEST_3_STATE: 2692 cont = processInitRequest3(qstate, iq, id); 2693 break; 2694 case QUERYTARGETS_STATE: 2695 cont = processQueryTargets(qstate, iq, ie, id); 2696 break; 2697 case QUERY_RESP_STATE: 2698 cont = processQueryResponse(qstate, iq, id); 2699 break; 2700 case PRIME_RESP_STATE: 2701 cont = processPrimeResponse(qstate, id); 2702 break; 2703 case COLLECT_CLASS_STATE: 2704 cont = processCollectClass(qstate, id); 2705 break; 2706 case DSNS_FIND_STATE: 2707 cont = processDSNSFind(qstate, iq, id); 2708 break; 2709 case FINISHED_STATE: 2710 cont = processFinished(qstate, iq, id); 2711 break; 2712 default: 2713 log_warn("iterator: invalid state: %d", 2714 iq->state); 2715 cont = 0; 2716 break; 2717 } 2718 } 2719} 2720 2721/** 2722 * This is the primary entry point for processing request events. Note that 2723 * this method should only be used by external modules. 2724 * @param qstate: query state. 2725 * @param ie: iterator shared global environment. 2726 * @param iq: iterator query state. 2727 * @param id: module id. 2728 */ 2729static void 2730process_request(struct module_qstate* qstate, struct iter_qstate* iq, 2731 struct iter_env* ie, int id) 2732{ 2733 /* external requests start in the INIT state, and finish using the 2734 * FINISHED state. */ 2735 iq->state = INIT_REQUEST_STATE; 2736 iq->final_state = FINISHED_STATE; 2737 verbose(VERB_ALGO, "process_request: new external request event"); 2738 iter_handle(qstate, iq, ie, id); 2739} 2740 2741/** process authoritative server reply */ 2742static void 2743process_response(struct module_qstate* qstate, struct iter_qstate* iq, 2744 struct iter_env* ie, int id, struct outbound_entry* outbound, 2745 enum module_ev event) 2746{ 2747 struct msg_parse* prs; 2748 struct edns_data edns; 2749 ldns_buffer* pkt; 2750 2751 verbose(VERB_ALGO, "process_response: new external response event"); 2752 iq->response = NULL; 2753 iq->state = QUERY_RESP_STATE; 2754 if(event == module_event_noreply || event == module_event_error) { 2755 goto handle_it; 2756 } 2757 if( (event != module_event_reply && event != module_event_capsfail) 2758 || !qstate->reply) { 2759 log_err("Bad event combined with response"); 2760 outbound_list_remove(&iq->outlist, outbound); 2761 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2762 return; 2763 } 2764 2765 /* parse message */ 2766 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch, 2767 sizeof(struct msg_parse)); 2768 if(!prs) { 2769 log_err("out of memory on incoming message"); 2770 /* like packet got dropped */ 2771 goto handle_it; 2772 } 2773 memset(prs, 0, sizeof(*prs)); 2774 memset(&edns, 0, sizeof(edns)); 2775 pkt = qstate->reply->c->buffer; 2776 ldns_buffer_set_position(pkt, 0); 2777 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) { 2778 verbose(VERB_ALGO, "parse error on reply packet"); 2779 goto handle_it; 2780 } 2781 /* edns is not examined, but removed from message to help cache */ 2782 if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR) 2783 goto handle_it; 2784 /* remove CD-bit, we asked for in case we handle validation ourself */ 2785 prs->flags &= ~BIT_CD; 2786 2787 /* normalize and sanitize: easy to delete items from linked lists */ 2788 if(!scrub_message(pkt, prs, &iq->qchase, iq->dp->name, 2789 qstate->env->scratch, qstate->env, ie)) 2790 goto handle_it; 2791 2792 /* allocate response dns_msg in region */ 2793 iq->response = dns_alloc_msg(pkt, prs, qstate->region); 2794 if(!iq->response) 2795 goto handle_it; 2796 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo); 2797 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name, 2798 &qstate->reply->addr, qstate->reply->addrlen); 2799 if(verbosity >= VERB_ALGO) 2800 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo, 2801 iq->response->rep); 2802 2803 if(event == module_event_capsfail) { 2804 if(!iq->caps_fallback) { 2805 /* start fallback */ 2806 iq->caps_fallback = 1; 2807 iq->caps_server = 0; 2808 iq->caps_reply = iq->response->rep; 2809 iq->state = QUERYTARGETS_STATE; 2810 iq->num_current_queries--; 2811 verbose(VERB_DETAIL, "Capsforid: starting fallback"); 2812 goto handle_it; 2813 } else { 2814 /* check if reply is the same, otherwise, fail */ 2815 if(!reply_equal(iq->response->rep, iq->caps_reply, 2816 qstate->env->scratch_buffer)) { 2817 verbose(VERB_DETAIL, "Capsforid fallback: " 2818 "getting different replies, failed"); 2819 outbound_list_remove(&iq->outlist, outbound); 2820 (void)error_response(qstate, id, 2821 LDNS_RCODE_SERVFAIL); 2822 return; 2823 } 2824 /* continue the fallback procedure at next server */ 2825 iq->caps_server++; 2826 iq->state = QUERYTARGETS_STATE; 2827 iq->num_current_queries--; 2828 verbose(VERB_DETAIL, "Capsforid: reply is equal. " 2829 "go to next fallback"); 2830 goto handle_it; 2831 } 2832 } 2833 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */ 2834 2835handle_it: 2836 outbound_list_remove(&iq->outlist, outbound); 2837 iter_handle(qstate, iq, ie, id); 2838} 2839 2840void 2841iter_operate(struct module_qstate* qstate, enum module_ev event, int id, 2842 struct outbound_entry* outbound) 2843{ 2844 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 2845 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2846 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s", 2847 id, strextstate(qstate->ext_state[id]), strmodulevent(event)); 2848 if(iq) log_query_info(VERB_QUERY, "iterator operate: query", 2849 &qstate->qinfo); 2850 if(iq && qstate->qinfo.qname != iq->qchase.qname) 2851 log_query_info(VERB_QUERY, "iterator operate: chased to", 2852 &iq->qchase); 2853 2854 /* perform iterator state machine */ 2855 if((event == module_event_new || event == module_event_pass) && 2856 iq == NULL) { 2857 if(!iter_new(qstate, id)) { 2858 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2859 return; 2860 } 2861 iq = (struct iter_qstate*)qstate->minfo[id]; 2862 process_request(qstate, iq, ie, id); 2863 return; 2864 } 2865 if(iq && event == module_event_pass) { 2866 iter_handle(qstate, iq, ie, id); 2867 return; 2868 } 2869 if(iq && outbound) { 2870 process_response(qstate, iq, ie, id, outbound, event); 2871 return; 2872 } 2873 if(event == module_event_error) { 2874 verbose(VERB_ALGO, "got called with event error, giving up"); 2875 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2876 return; 2877 } 2878 2879 log_err("bad event for iterator"); 2880 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2881} 2882 2883void 2884iter_clear(struct module_qstate* qstate, int id) 2885{ 2886 struct iter_qstate* iq; 2887 if(!qstate) 2888 return; 2889 iq = (struct iter_qstate*)qstate->minfo[id]; 2890 if(iq) { 2891 outbound_list_clear(&iq->outlist); 2892 if(iq->target_count && --iq->target_count[0] == 0) 2893 free(iq->target_count); 2894 iq->num_current_queries = 0; 2895 } 2896 qstate->minfo[id] = NULL; 2897} 2898 2899size_t 2900iter_get_mem(struct module_env* env, int id) 2901{ 2902 struct iter_env* ie = (struct iter_env*)env->modinfo[id]; 2903 if(!ie) 2904 return 0; 2905 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1) 2906 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv); 2907} 2908 2909/** 2910 * The iterator function block 2911 */ 2912static struct module_func_block iter_block = { 2913 "iterator", 2914 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super, 2915 &iter_clear, &iter_get_mem 2916}; 2917 2918struct module_func_block* 2919iter_get_funcblock(void) 2920{ 2921 return &iter_block; 2922} 2923 2924const char* 2925iter_state_to_string(enum iter_state state) 2926{ 2927 switch (state) 2928 { 2929 case INIT_REQUEST_STATE : 2930 return "INIT REQUEST STATE"; 2931 case INIT_REQUEST_2_STATE : 2932 return "INIT REQUEST STATE (stage 2)"; 2933 case INIT_REQUEST_3_STATE: 2934 return "INIT REQUEST STATE (stage 3)"; 2935 case QUERYTARGETS_STATE : 2936 return "QUERY TARGETS STATE"; 2937 case PRIME_RESP_STATE : 2938 return "PRIME RESPONSE STATE"; 2939 case COLLECT_CLASS_STATE : 2940 return "COLLECT CLASS STATE"; 2941 case DSNS_FIND_STATE : 2942 return "DSNS FIND STATE"; 2943 case QUERY_RESP_STATE : 2944 return "QUERY RESPONSE STATE"; 2945 case FINISHED_STATE : 2946 return "FINISHED RESPONSE STATE"; 2947 default : 2948 return "UNKNOWN ITER STATE"; 2949 } 2950} 2951 2952int 2953iter_state_is_responsestate(enum iter_state s) 2954{ 2955 switch(s) { 2956 case INIT_REQUEST_STATE : 2957 case INIT_REQUEST_2_STATE : 2958 case INIT_REQUEST_3_STATE : 2959 case QUERYTARGETS_STATE : 2960 case COLLECT_CLASS_STATE : 2961 return 0; 2962 default: 2963 break; 2964 } 2965 return 1; 2966} 2967