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 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * 39 * This file contains a module that performs recusive iterative DNS query 40 * processing. 41 */ 42 43 #include "config.h" 44 #include "iterator/iterator.h" 45 #include "iterator/iter_utils.h" 46 #include "iterator/iter_hints.h" 47 #include "iterator/iter_fwd.h" 48 #include "iterator/iter_donotq.h" 49 #include "iterator/iter_delegpt.h" 50 #include "iterator/iter_resptype.h" 51 #include "iterator/iter_scrub.h" 52 #include "iterator/iter_priv.h" 53 #include "validator/val_neg.h" 54 #include "services/cache/dns.h" 55 #include "services/cache/infra.h" 56 #include "util/module.h" 57 #include "util/netevent.h" 58 #include "util/net_help.h" 59 #include "util/regional.h" 60 #include "util/data/dname.h" 61 #include "util/data/msgencode.h" 62 #include "util/fptr_wlist.h" 63 #include "util/config_file.h" 64 #include "util/random.h" 65 #include "sldns/rrdef.h" 66 #include "sldns/wire2str.h" 67 #include "sldns/str2wire.h" 68 #include "sldns/parseutil.h" 69 #include "sldns/sbuffer.h" 70 71 int 72 iter_init(struct module_env* env, int id) 73 { 74 struct iter_env* iter_env = (struct iter_env*)calloc(1, 75 sizeof(struct iter_env)); 76 if(!iter_env) { 77 log_err("malloc failure"); 78 return 0; 79 } 80 env->modinfo[id] = (void*)iter_env; 81 if(!iter_apply_cfg(iter_env, env->cfg)) { 82 log_err("iterator: could not apply configuration settings."); 83 return 0; 84 } 85 86 return 1; 87 } 88 89 /** delete caps_whitelist element */ 90 static void 91 caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d)) 92 { 93 if(n) { 94 free(((struct name_tree_node*)n)->name); 95 free(n); 96 } 97 } 98 99 void 100 iter_deinit(struct module_env* env, int id) 101 { 102 struct iter_env* iter_env; 103 if(!env || !env->modinfo[id]) 104 return; 105 iter_env = (struct iter_env*)env->modinfo[id]; 106 free(iter_env->target_fetch_policy); 107 priv_delete(iter_env->priv); 108 donotq_delete(iter_env->donotq); 109 if(iter_env->caps_white) { 110 traverse_postorder(iter_env->caps_white, caps_free, NULL); 111 free(iter_env->caps_white); 112 } 113 free(iter_env); 114 env->modinfo[id] = NULL; 115 } 116 117 /** new query for iterator */ 118 static int 119 iter_new(struct module_qstate* qstate, int id) 120 { 121 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( 122 qstate->region, sizeof(struct iter_qstate)); 123 qstate->minfo[id] = iq; 124 if(!iq) 125 return 0; 126 memset(iq, 0, sizeof(*iq)); 127 iq->state = INIT_REQUEST_STATE; 128 iq->final_state = FINISHED_STATE; 129 iq->an_prepend_list = NULL; 130 iq->an_prepend_last = NULL; 131 iq->ns_prepend_list = NULL; 132 iq->ns_prepend_last = NULL; 133 iq->dp = NULL; 134 iq->depth = 0; 135 iq->num_target_queries = 0; 136 iq->num_current_queries = 0; 137 iq->query_restart_count = 0; 138 iq->referral_count = 0; 139 iq->sent_count = 0; 140 iq->ratelimit_ok = 0; 141 iq->target_count = NULL; 142 iq->wait_priming_stub = 0; 143 iq->refetch_glue = 0; 144 iq->dnssec_expected = 0; 145 iq->dnssec_lame_query = 0; 146 iq->chase_flags = qstate->query_flags; 147 /* Start with the (current) qname. */ 148 iq->qchase = qstate->qinfo; 149 outbound_list_init(&iq->outlist); 150 iq->minimise_count = 0; 151 iq->minimise_timeout_count = 0; 152 if (qstate->env->cfg->qname_minimisation) 153 iq->minimisation_state = INIT_MINIMISE_STATE; 154 else 155 iq->minimisation_state = DONOT_MINIMISE_STATE; 156 157 memset(&iq->qinfo_out, 0, sizeof(struct query_info)); 158 return 1; 159 } 160 161 /** 162 * Transition to the next state. This can be used to advance a currently 163 * processing event. It cannot be used to reactivate a forEvent. 164 * 165 * @param iq: iterator query state 166 * @param nextstate The state to transition to. 167 * @return true. This is so this can be called as the return value for the 168 * actual process*State() methods. (Transitioning to the next state 169 * implies further processing). 170 */ 171 static int 172 next_state(struct iter_qstate* iq, enum iter_state nextstate) 173 { 174 /* If transitioning to a "response" state, make sure that there is a 175 * response */ 176 if(iter_state_is_responsestate(nextstate)) { 177 if(iq->response == NULL) { 178 log_err("transitioning to response state sans " 179 "response."); 180 } 181 } 182 iq->state = nextstate; 183 return 1; 184 } 185 186 /** 187 * Transition an event to its final state. Final states always either return 188 * a result up the module chain, or reactivate a dependent event. Which 189 * final state to transition to is set in the module state for the event when 190 * it was created, and depends on the original purpose of the event. 191 * 192 * The response is stored in the qstate->buf buffer. 193 * 194 * @param iq: iterator query state 195 * @return false. This is so this method can be used as the return value for 196 * the processState methods. (Transitioning to the final state 197 */ 198 static int 199 final_state(struct iter_qstate* iq) 200 { 201 return next_state(iq, iq->final_state); 202 } 203 204 /** 205 * Callback routine to handle errors in parent query states 206 * @param qstate: query state that failed. 207 * @param id: module id. 208 * @param super: super state. 209 */ 210 static void 211 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super) 212 { 213 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; 214 215 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || 216 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { 217 /* mark address as failed. */ 218 struct delegpt_ns* dpns = NULL; 219 super_iq->num_target_queries--; 220 if(super_iq->dp) 221 dpns = delegpt_find_ns(super_iq->dp, 222 qstate->qinfo.qname, qstate->qinfo.qname_len); 223 if(!dpns) { 224 /* not interested */ 225 verbose(VERB_ALGO, "subq error, but not interested"); 226 log_query_info(VERB_ALGO, "superq", &super->qinfo); 227 if(super_iq->dp) 228 delegpt_log(VERB_ALGO, super_iq->dp); 229 log_assert(0); 230 return; 231 } else { 232 /* see if the failure did get (parent-lame) info */ 233 if(!cache_fill_missing(super->env, super_iq->qchase.qclass, 234 super->region, super_iq->dp)) 235 log_err("out of memory adding missing"); 236 } 237 dpns->resolved = 1; /* mark as failed */ 238 } 239 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { 240 /* prime failed to get delegation */ 241 super_iq->dp = NULL; 242 } 243 /* evaluate targets again */ 244 super_iq->state = QUERYTARGETS_STATE; 245 /* super becomes runnable, and will process this change */ 246 } 247 248 /** 249 * Return an error to the client 250 * @param qstate: our query state 251 * @param id: module id 252 * @param rcode: error code (DNS errcode). 253 * @return: 0 for use by caller, to make notation easy, like: 254 * return error_response(..). 255 */ 256 static int 257 error_response(struct module_qstate* qstate, int id, int rcode) 258 { 259 verbose(VERB_QUERY, "return error response %s", 260 sldns_lookup_by_id(sldns_rcodes, rcode)? 261 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??"); 262 qstate->return_rcode = rcode; 263 qstate->return_msg = NULL; 264 qstate->ext_state[id] = module_finished; 265 return 0; 266 } 267 268 /** 269 * Return an error to the client and cache the error code in the 270 * message cache (so per qname, qtype, qclass). 271 * @param qstate: our query state 272 * @param id: module id 273 * @param rcode: error code (DNS errcode). 274 * @return: 0 for use by caller, to make notation easy, like: 275 * return error_response(..). 276 */ 277 static int 278 error_response_cache(struct module_qstate* qstate, int id, int rcode) 279 { 280 if(!qstate->no_cache_store) { 281 /* store in cache */ 282 struct reply_info err; 283 if(qstate->prefetch_leeway > NORR_TTL) { 284 verbose(VERB_ALGO, "error response for prefetch in cache"); 285 /* attempt to adjust the cache entry prefetch */ 286 if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo, 287 NORR_TTL, qstate->query_flags)) 288 return error_response(qstate, id, rcode); 289 /* if that fails (not in cache), fall through to store err */ 290 } 291 if(qstate->env->cfg->serve_expired) { 292 /* if serving expired contents, and such content is 293 * already available, don't overwrite this servfail */ 294 struct msgreply_entry* msg; 295 if((msg=msg_cache_lookup(qstate->env, 296 qstate->qinfo.qname, qstate->qinfo.qname_len, 297 qstate->qinfo.qtype, qstate->qinfo.qclass, 298 qstate->query_flags, 0, 0)) 299 != NULL) { 300 lock_rw_unlock(&msg->entry.lock); 301 return error_response(qstate, id, rcode); 302 } 303 /* serving expired contents, but nothing is cached 304 * at all, so the servfail cache entry is useful 305 * (stops waste of time on this servfail NORR_TTL) */ 306 } 307 memset(&err, 0, sizeof(err)); 308 err.flags = (uint16_t)(BIT_QR | BIT_RA); 309 FLAGS_SET_RCODE(err.flags, rcode); 310 err.qdcount = 1; 311 err.ttl = NORR_TTL; 312 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); 313 /* do not waste time trying to validate this servfail */ 314 err.security = sec_status_indeterminate; 315 verbose(VERB_ALGO, "store error response in message cache"); 316 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL, 317 qstate->query_flags); 318 } 319 return error_response(qstate, id, rcode); 320 } 321 322 /** check if prepend item is duplicate item */ 323 static int 324 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, 325 struct ub_packed_rrset_key* dup) 326 { 327 size_t i; 328 for(i=0; i<to; i++) { 329 if(sets[i]->rk.type == dup->rk.type && 330 sets[i]->rk.rrset_class == dup->rk.rrset_class && 331 sets[i]->rk.dname_len == dup->rk.dname_len && 332 query_dname_compare(sets[i]->rk.dname, dup->rk.dname) 333 == 0) 334 return 1; 335 } 336 return 0; 337 } 338 339 /** prepend the prepend list in the answer and authority section of dns_msg */ 340 static int 341 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, 342 struct regional* region) 343 { 344 struct iter_prep_list* p; 345 struct ub_packed_rrset_key** sets; 346 size_t num_an = 0, num_ns = 0;; 347 for(p = iq->an_prepend_list; p; p = p->next) 348 num_an++; 349 for(p = iq->ns_prepend_list; p; p = p->next) 350 num_ns++; 351 if(num_an + num_ns == 0) 352 return 1; 353 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); 354 if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX || 355 msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */ 356 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * 357 sizeof(struct ub_packed_rrset_key*)); 358 if(!sets) 359 return 0; 360 /* ANSWER section */ 361 num_an = 0; 362 for(p = iq->an_prepend_list; p; p = p->next) { 363 sets[num_an++] = p->rrset; 364 } 365 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * 366 sizeof(struct ub_packed_rrset_key*)); 367 /* AUTH section */ 368 num_ns = 0; 369 for(p = iq->ns_prepend_list; p; p = p->next) { 370 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, 371 num_ns, p->rrset) || prepend_is_duplicate( 372 msg->rep->rrsets+msg->rep->an_numrrsets, 373 msg->rep->ns_numrrsets, p->rrset)) 374 continue; 375 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; 376 } 377 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, 378 msg->rep->rrsets + msg->rep->an_numrrsets, 379 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * 380 sizeof(struct ub_packed_rrset_key*)); 381 382 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because 383 * this is what recursors should give. */ 384 msg->rep->rrset_count += num_an + num_ns; 385 msg->rep->an_numrrsets += num_an; 386 msg->rep->ns_numrrsets += num_ns; 387 msg->rep->rrsets = sets; 388 return 1; 389 } 390 391 /** 392 * Find rrset in ANSWER prepend list. 393 * to avoid duplicate DNAMEs when a DNAME is traversed twice. 394 * @param iq: iterator query state. 395 * @param rrset: rrset to add. 396 * @return false if not found 397 */ 398 static int 399 iter_find_rrset_in_prepend_answer(struct iter_qstate* iq, 400 struct ub_packed_rrset_key* rrset) 401 { 402 struct iter_prep_list* p = iq->an_prepend_list; 403 while(p) { 404 if(ub_rrset_compare(p->rrset, rrset) == 0 && 405 rrsetdata_equal((struct packed_rrset_data*)p->rrset 406 ->entry.data, (struct packed_rrset_data*)rrset 407 ->entry.data)) 408 return 1; 409 p = p->next; 410 } 411 return 0; 412 } 413 414 /** 415 * Add rrset to ANSWER prepend list 416 * @param qstate: query state. 417 * @param iq: iterator query state. 418 * @param rrset: rrset to add. 419 * @return false on failure (malloc). 420 */ 421 static int 422 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, 423 struct ub_packed_rrset_key* rrset) 424 { 425 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 426 qstate->region, sizeof(struct iter_prep_list)); 427 if(!p) 428 return 0; 429 p->rrset = rrset; 430 p->next = NULL; 431 /* add at end */ 432 if(iq->an_prepend_last) 433 iq->an_prepend_last->next = p; 434 else iq->an_prepend_list = p; 435 iq->an_prepend_last = p; 436 return 1; 437 } 438 439 /** 440 * Add rrset to AUTHORITY prepend list 441 * @param qstate: query state. 442 * @param iq: iterator query state. 443 * @param rrset: rrset to add. 444 * @return false on failure (malloc). 445 */ 446 static int 447 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, 448 struct ub_packed_rrset_key* rrset) 449 { 450 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 451 qstate->region, sizeof(struct iter_prep_list)); 452 if(!p) 453 return 0; 454 p->rrset = rrset; 455 p->next = NULL; 456 /* add at end */ 457 if(iq->ns_prepend_last) 458 iq->ns_prepend_last->next = p; 459 else iq->ns_prepend_list = p; 460 iq->ns_prepend_last = p; 461 return 1; 462 } 463 464 /** 465 * Given a CNAME response (defined as a response containing a CNAME or DNAME 466 * that does not answer the request), process the response, modifying the 467 * state as necessary. This follows the CNAME/DNAME chain and returns the 468 * final query name. 469 * 470 * sets the new query name, after following the CNAME/DNAME chain. 471 * @param qstate: query state. 472 * @param iq: iterator query state. 473 * @param msg: the response. 474 * @param mname: returned target new query name. 475 * @param mname_len: length of mname. 476 * @return false on (malloc) error. 477 */ 478 static int 479 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, 480 struct dns_msg* msg, uint8_t** mname, size_t* mname_len) 481 { 482 size_t i; 483 /* Start with the (current) qname. */ 484 *mname = iq->qchase.qname; 485 *mname_len = iq->qchase.qname_len; 486 487 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and 488 * DNAMES. */ 489 for(i=0; i<msg->rep->an_numrrsets; i++) { 490 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 491 /* If there is a (relevant) DNAME, add it to the list. 492 * We always expect there to be CNAME that was generated 493 * by this DNAME following, so we don't process the DNAME 494 * directly. */ 495 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && 496 dname_strict_subdomain_c(*mname, r->rk.dname) && 497 !iter_find_rrset_in_prepend_answer(iq, r)) { 498 if(!iter_add_prepend_answer(qstate, iq, r)) 499 return 0; 500 continue; 501 } 502 503 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && 504 query_dname_compare(*mname, r->rk.dname) == 0 && 505 !iter_find_rrset_in_prepend_answer(iq, r)) { 506 /* Add this relevant CNAME rrset to the prepend list.*/ 507 if(!iter_add_prepend_answer(qstate, iq, r)) 508 return 0; 509 get_cname_target(r, mname, mname_len); 510 } 511 512 /* Other rrsets in the section are ignored. */ 513 } 514 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ 515 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + 516 msg->rep->ns_numrrsets; i++) { 517 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 518 /* only add NSEC/NSEC3, as they may be needed for validation */ 519 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC || 520 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { 521 if(!iter_add_prepend_auth(qstate, iq, r)) 522 return 0; 523 } 524 } 525 return 1; 526 } 527 528 /** see if last resort is possible - does config allow queries to parent */ 529 static int 530 can_have_last_resort(struct module_env* env, uint8_t* nm, size_t nmlen, 531 uint16_t qclass) 532 { 533 struct delegpt* fwddp; 534 struct iter_hints_stub* stub; 535 int labs = dname_count_labels(nm); 536 /* do not process a last resort (the parent side) if a stub 537 * or forward is configured, because we do not want to go 'above' 538 * the configured servers */ 539 if(!dname_is_root(nm) && (stub = (struct iter_hints_stub*) 540 name_tree_find(&env->hints->tree, nm, nmlen, labs, qclass)) && 541 /* has_parent side is turned off for stub_first, where we 542 * are allowed to go to the parent */ 543 stub->dp->has_parent_side_NS) { 544 return 0; 545 } 546 if((fwddp = forwards_find(env->fwds, nm, qclass)) && 547 /* has_parent_side is turned off for forward_first, where 548 * we are allowed to go to the parent */ 549 fwddp->has_parent_side_NS) { 550 return 0; 551 } 552 return 1; 553 } 554 555 /** see if target name is caps-for-id whitelisted */ 556 static int 557 is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq) 558 { 559 if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */ 560 return name_tree_lookup(ie->caps_white, iq->qchase.qname, 561 iq->qchase.qname_len, dname_count_labels(iq->qchase.qname), 562 iq->qchase.qclass) != NULL; 563 } 564 565 /** create target count structure for this query */ 566 static void 567 target_count_create(struct iter_qstate* iq) 568 { 569 if(!iq->target_count) { 570 iq->target_count = (int*)calloc(2, sizeof(int)); 571 /* if calloc fails we simply do not track this number */ 572 if(iq->target_count) 573 iq->target_count[0] = 1; 574 } 575 } 576 577 static void 578 target_count_increase(struct iter_qstate* iq, int num) 579 { 580 target_count_create(iq); 581 if(iq->target_count) 582 iq->target_count[1] += num; 583 } 584 585 /** 586 * Generate a subrequest. 587 * Generate a local request event. Local events are tied to this module, and 588 * have a corresponding (first tier) event that is waiting for this event to 589 * resolve to continue. 590 * 591 * @param qname The query name for this request. 592 * @param qnamelen length of qname 593 * @param qtype The query type for this request. 594 * @param qclass The query class for this request. 595 * @param qstate The event that is generating this event. 596 * @param id: module id. 597 * @param iq: The iterator state that is generating this event. 598 * @param initial_state The initial response state (normally this 599 * is QUERY_RESP_STATE, unless it is known that the request won't 600 * need iterative processing 601 * @param finalstate The final state for the response to this request. 602 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does 603 * not need initialisation. 604 * @param v: if true, validation is done on the subquery. 605 * @return false on error (malloc). 606 */ 607 static int 608 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, 609 uint16_t qclass, struct module_qstate* qstate, int id, 610 struct iter_qstate* iq, enum iter_state initial_state, 611 enum iter_state finalstate, struct module_qstate** subq_ret, int v) 612 { 613 struct module_qstate* subq = NULL; 614 struct iter_qstate* subiq = NULL; 615 uint16_t qflags = 0; /* OPCODE QUERY, no flags */ 616 struct query_info qinf; 617 int prime = (finalstate == PRIME_RESP_STATE)?1:0; 618 int valrec = 0; 619 qinf.qname = qname; 620 qinf.qname_len = qnamelen; 621 qinf.qtype = qtype; 622 qinf.qclass = qclass; 623 qinf.local_alias = NULL; 624 625 /* RD should be set only when sending the query back through the INIT 626 * state. */ 627 if(initial_state == INIT_REQUEST_STATE) 628 qflags |= BIT_RD; 629 /* We set the CD flag so we can send this through the "head" of 630 * the resolution chain, which might have a validator. We are 631 * uninterested in validating things not on the direct resolution 632 * path. */ 633 if(!v) { 634 qflags |= BIT_CD; 635 valrec = 1; 636 } 637 638 /* attach subquery, lookup existing or make a new one */ 639 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub)); 640 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, valrec, 641 &subq)) { 642 return 0; 643 } 644 *subq_ret = subq; 645 if(subq) { 646 /* initialise the new subquery */ 647 subq->curmod = id; 648 subq->ext_state[id] = module_state_initial; 649 subq->minfo[id] = regional_alloc(subq->region, 650 sizeof(struct iter_qstate)); 651 if(!subq->minfo[id]) { 652 log_err("init subq: out of memory"); 653 fptr_ok(fptr_whitelist_modenv_kill_sub( 654 qstate->env->kill_sub)); 655 (*qstate->env->kill_sub)(subq); 656 return 0; 657 } 658 subiq = (struct iter_qstate*)subq->minfo[id]; 659 memset(subiq, 0, sizeof(*subiq)); 660 subiq->num_target_queries = 0; 661 target_count_create(iq); 662 subiq->target_count = iq->target_count; 663 if(iq->target_count) 664 iq->target_count[0] ++; /* extra reference */ 665 subiq->num_current_queries = 0; 666 subiq->depth = iq->depth+1; 667 outbound_list_init(&subiq->outlist); 668 subiq->state = initial_state; 669 subiq->final_state = finalstate; 670 subiq->qchase = subq->qinfo; 671 subiq->chase_flags = subq->query_flags; 672 subiq->refetch_glue = 0; 673 if(qstate->env->cfg->qname_minimisation) 674 subiq->minimisation_state = INIT_MINIMISE_STATE; 675 else 676 subiq->minimisation_state = DONOT_MINIMISE_STATE; 677 memset(&subiq->qinfo_out, 0, sizeof(struct query_info)); 678 } 679 return 1; 680 } 681 682 /** 683 * Generate and send a root priming request. 684 * @param qstate: the qtstate that triggered the need to prime. 685 * @param iq: iterator query state. 686 * @param id: module id. 687 * @param qclass: the class to prime. 688 * @return 0 on failure 689 */ 690 static int 691 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id, 692 uint16_t qclass) 693 { 694 struct delegpt* dp; 695 struct module_qstate* subq; 696 verbose(VERB_DETAIL, "priming . %s NS", 697 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)? 698 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??"); 699 dp = hints_lookup_root(qstate->env->hints, qclass); 700 if(!dp) { 701 verbose(VERB_ALGO, "Cannot prime due to lack of hints"); 702 return 0; 703 } 704 /* Priming requests start at the QUERYTARGETS state, skipping 705 * the normal INIT state logic (which would cause an infloop). */ 706 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, 707 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE, 708 &subq, 0)) { 709 verbose(VERB_ALGO, "could not prime root"); 710 return 0; 711 } 712 if(subq) { 713 struct iter_qstate* subiq = 714 (struct iter_qstate*)subq->minfo[id]; 715 /* Set the initial delegation point to the hint. 716 * copy dp, it is now part of the root prime query. 717 * dp was part of in the fixed hints structure. */ 718 subiq->dp = delegpt_copy(dp, subq->region); 719 if(!subiq->dp) { 720 log_err("out of memory priming root, copydp"); 721 fptr_ok(fptr_whitelist_modenv_kill_sub( 722 qstate->env->kill_sub)); 723 (*qstate->env->kill_sub)(subq); 724 return 0; 725 } 726 /* there should not be any target queries. */ 727 subiq->num_target_queries = 0; 728 subiq->dnssec_expected = iter_indicates_dnssec( 729 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 730 } 731 732 /* this module stops, our submodule starts, and does the query. */ 733 qstate->ext_state[id] = module_wait_subquery; 734 return 1; 735 } 736 737 /** 738 * Generate and process a stub priming request. This method tests for the 739 * need to prime a stub zone, so it is safe to call for every request. 740 * 741 * @param qstate: the qtstate that triggered the need to prime. 742 * @param iq: iterator query state. 743 * @param id: module id. 744 * @param qname: request name. 745 * @param qclass: request class. 746 * @return true if a priming subrequest was made, false if not. The will only 747 * issue a priming request if it detects an unprimed stub. 748 * Uses value of 2 to signal during stub-prime in root-prime situation 749 * that a noprime-stub is available and resolution can continue. 750 */ 751 static int 752 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id, 753 uint8_t* qname, uint16_t qclass) 754 { 755 /* Lookup the stub hint. This will return null if the stub doesn't 756 * need to be re-primed. */ 757 struct iter_hints_stub* stub; 758 struct delegpt* stub_dp; 759 struct module_qstate* subq; 760 761 if(!qname) return 0; 762 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp); 763 /* The stub (if there is one) does not need priming. */ 764 if(!stub) 765 return 0; 766 stub_dp = stub->dp; 767 768 /* is it a noprime stub (always use) */ 769 if(stub->noprime) { 770 int r = 0; 771 if(iq->dp == NULL) r = 2; 772 /* copy the dp out of the fixed hints structure, so that 773 * it can be changed when servicing this query */ 774 iq->dp = delegpt_copy(stub_dp, qstate->region); 775 if(!iq->dp) { 776 log_err("out of memory priming stub"); 777 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 778 return 1; /* return 1 to make module stop, with error */ 779 } 780 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name, 781 LDNS_RR_TYPE_NS, qclass); 782 return r; 783 } 784 785 /* Otherwise, we need to (re)prime the stub. */ 786 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name, 787 LDNS_RR_TYPE_NS, qclass); 788 789 /* Stub priming events start at the QUERYTARGETS state to avoid the 790 * redundant INIT state processing. */ 791 if(!generate_sub_request(stub_dp->name, stub_dp->namelen, 792 LDNS_RR_TYPE_NS, qclass, qstate, id, iq, 793 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) { 794 verbose(VERB_ALGO, "could not prime stub"); 795 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 796 return 1; /* return 1 to make module stop, with error */ 797 } 798 if(subq) { 799 struct iter_qstate* subiq = 800 (struct iter_qstate*)subq->minfo[id]; 801 802 /* Set the initial delegation point to the hint. */ 803 /* make copy to avoid use of stub dp by different qs/threads */ 804 subiq->dp = delegpt_copy(stub_dp, subq->region); 805 if(!subiq->dp) { 806 log_err("out of memory priming stub, copydp"); 807 fptr_ok(fptr_whitelist_modenv_kill_sub( 808 qstate->env->kill_sub)); 809 (*qstate->env->kill_sub)(subq); 810 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 811 return 1; /* return 1 to make module stop, with error */ 812 } 813 /* there should not be any target queries -- although there 814 * wouldn't be anyway, since stub hints never have 815 * missing targets. */ 816 subiq->num_target_queries = 0; 817 subiq->wait_priming_stub = 1; 818 subiq->dnssec_expected = iter_indicates_dnssec( 819 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 820 } 821 822 /* this module stops, our submodule starts, and does the query. */ 823 qstate->ext_state[id] = module_wait_subquery; 824 return 1; 825 } 826 827 /** 828 * Generate A and AAAA checks for glue that is in-zone for the referral 829 * we just got to obtain authoritative information on the adresses. 830 * 831 * @param qstate: the qtstate that triggered the need to prime. 832 * @param iq: iterator query state. 833 * @param id: module id. 834 */ 835 static void 836 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq, 837 int id) 838 { 839 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 840 struct module_qstate* subq; 841 size_t i; 842 struct reply_info* rep = iq->response->rep; 843 struct ub_packed_rrset_key* s; 844 log_assert(iq->dp); 845 846 if(iq->depth == ie->max_dependency_depth) 847 return; 848 /* walk through additional, and check if in-zone, 849 * only relevant A, AAAA are left after scrub anyway */ 850 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { 851 s = rep->rrsets[i]; 852 /* check *ALL* addresses that are transmitted in additional*/ 853 /* is it an address ? */ 854 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A || 855 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) { 856 continue; 857 } 858 /* is this query the same as the A/AAAA check for it */ 859 if(qstate->qinfo.qtype == ntohs(s->rk.type) && 860 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) && 861 query_dname_compare(qstate->qinfo.qname, 862 s->rk.dname)==0 && 863 (qstate->query_flags&BIT_RD) && 864 !(qstate->query_flags&BIT_CD)) 865 continue; 866 867 /* generate subrequest for it */ 868 log_nametypeclass(VERB_ALGO, "schedule addr fetch", 869 s->rk.dname, ntohs(s->rk.type), 870 ntohs(s->rk.rrset_class)); 871 if(!generate_sub_request(s->rk.dname, s->rk.dname_len, 872 ntohs(s->rk.type), ntohs(s->rk.rrset_class), 873 qstate, id, iq, 874 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 875 verbose(VERB_ALGO, "could not generate addr check"); 876 return; 877 } 878 /* ignore subq - not need for more init */ 879 } 880 } 881 882 /** 883 * Generate a NS check request to obtain authoritative information 884 * on an NS rrset. 885 * 886 * @param qstate: the qtstate that triggered the need to prime. 887 * @param iq: iterator query state. 888 * @param id: module id. 889 */ 890 static void 891 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id) 892 { 893 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 894 struct module_qstate* subq; 895 log_assert(iq->dp); 896 897 if(iq->depth == ie->max_dependency_depth) 898 return; 899 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, 900 iq->qchase.qclass)) 901 return; 902 /* is this query the same as the nscheck? */ 903 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS && 904 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 905 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 906 /* spawn off A, AAAA queries for in-zone glue to check */ 907 generate_a_aaaa_check(qstate, iq, id); 908 return; 909 } 910 911 log_nametypeclass(VERB_ALGO, "schedule ns fetch", 912 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 913 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 914 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 915 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 916 verbose(VERB_ALGO, "could not generate ns check"); 917 return; 918 } 919 if(subq) { 920 struct iter_qstate* subiq = 921 (struct iter_qstate*)subq->minfo[id]; 922 923 /* make copy to avoid use of stub dp by different qs/threads */ 924 /* refetch glue to start higher up the tree */ 925 subiq->refetch_glue = 1; 926 subiq->dp = delegpt_copy(iq->dp, subq->region); 927 if(!subiq->dp) { 928 log_err("out of memory generating ns check, copydp"); 929 fptr_ok(fptr_whitelist_modenv_kill_sub( 930 qstate->env->kill_sub)); 931 (*qstate->env->kill_sub)(subq); 932 return; 933 } 934 } 935 } 936 937 /** 938 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we 939 * just got in a referral (where we have dnssec_expected, thus have trust 940 * anchors above it). Note that right after calling this routine the 941 * iterator detached subqueries (because of following the referral), and thus 942 * the DNSKEY query becomes detached, its return stored in the cache for 943 * later lookup by the validator. This cache lookup by the validator avoids 944 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now 945 * performed at about the same time the original query is sent to the domain, 946 * thus the two answers are likely to be returned at about the same time, 947 * saving a roundtrip from the validated lookup. 948 * 949 * @param qstate: the qtstate that triggered the need to prime. 950 * @param iq: iterator query state. 951 * @param id: module id. 952 */ 953 static void 954 generate_dnskey_prefetch(struct module_qstate* qstate, 955 struct iter_qstate* iq, int id) 956 { 957 struct module_qstate* subq; 958 log_assert(iq->dp); 959 960 /* is this query the same as the prefetch? */ 961 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY && 962 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 963 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 964 return; 965 } 966 967 /* if the DNSKEY is in the cache this lookup will stop quickly */ 968 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch", 969 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass); 970 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 971 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq, 972 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 973 /* we'll be slower, but it'll work */ 974 verbose(VERB_ALGO, "could not generate dnskey prefetch"); 975 return; 976 } 977 if(subq) { 978 struct iter_qstate* subiq = 979 (struct iter_qstate*)subq->minfo[id]; 980 /* this qstate has the right delegation for the dnskey lookup*/ 981 /* make copy to avoid use of stub dp by different qs/threads */ 982 subiq->dp = delegpt_copy(iq->dp, subq->region); 983 /* if !subiq->dp, it'll start from the cache, no problem */ 984 } 985 } 986 987 /** 988 * See if the query needs forwarding. 989 * 990 * @param qstate: query state. 991 * @param iq: iterator query state. 992 * @return true if the request is forwarded, false if not. 993 * If returns true but, iq->dp is NULL then a malloc failure occurred. 994 */ 995 static int 996 forward_request(struct module_qstate* qstate, struct iter_qstate* iq) 997 { 998 struct delegpt* dp; 999 uint8_t* delname = iq->qchase.qname; 1000 size_t delnamelen = iq->qchase.qname_len; 1001 if(iq->refetch_glue) { 1002 delname = iq->dp->name; 1003 delnamelen = iq->dp->namelen; 1004 } 1005 /* strip one label off of DS query to lookup higher for it */ 1006 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) 1007 && !dname_is_root(iq->qchase.qname)) 1008 dname_remove_label(&delname, &delnamelen); 1009 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass); 1010 if(!dp) 1011 return 0; 1012 /* send recursion desired to forward addr */ 1013 iq->chase_flags |= BIT_RD; 1014 iq->dp = delegpt_copy(dp, qstate->region); 1015 /* iq->dp checked by caller */ 1016 verbose(VERB_ALGO, "forwarding request"); 1017 return 1; 1018 } 1019 1020 /** 1021 * Process the initial part of the request handling. This state roughly 1022 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2 1023 * (find the best servers to ask). 1024 * 1025 * Note that all requests start here, and query restarts revisit this state. 1026 * 1027 * This state either generates: 1) a response, from cache or error, 2) a 1028 * priming event, or 3) forwards the request to the next state (init2, 1029 * generally). 1030 * 1031 * @param qstate: query state. 1032 * @param iq: iterator query state. 1033 * @param ie: iterator shared global environment. 1034 * @param id: module id. 1035 * @return true if the event needs more request processing immediately, 1036 * false if not. 1037 */ 1038 static int 1039 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq, 1040 struct iter_env* ie, int id) 1041 { 1042 uint8_t* delname; 1043 size_t delnamelen; 1044 struct dns_msg* msg = NULL; 1045 1046 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo); 1047 /* check effort */ 1048 1049 /* We enforce a maximum number of query restarts. This is primarily a 1050 * cheap way to prevent CNAME loops. */ 1051 if(iq->query_restart_count > MAX_RESTART_COUNT) { 1052 verbose(VERB_QUERY, "request has exceeded the maximum number" 1053 " of query restarts with %d", iq->query_restart_count); 1054 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1055 } 1056 1057 /* We enforce a maximum recursion/dependency depth -- in general, 1058 * this is unnecessary for dependency loops (although it will 1059 * catch those), but it provides a sensible limit to the amount 1060 * of work required to answer a given query. */ 1061 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth); 1062 if(iq->depth > ie->max_dependency_depth) { 1063 verbose(VERB_QUERY, "request has exceeded the maximum " 1064 "dependency depth with depth of %d", iq->depth); 1065 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1066 } 1067 1068 /* If the request is qclass=ANY, setup to generate each class */ 1069 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) { 1070 iq->qchase.qclass = 0; 1071 return next_state(iq, COLLECT_CLASS_STATE); 1072 } 1073 1074 /* 1075 * If we are restricted by a forward-zone or a stub-zone, we 1076 * can't re-fetch glue for this delegation point. 1077 * we won’t try to re-fetch glue if the iq->dp is null. 1078 */ 1079 if (iq->refetch_glue && 1080 iq->dp && 1081 !can_have_last_resort(qstate->env, 1082 iq->dp->name, 1083 iq->dp->namelen, 1084 iq->qchase.qclass)) { 1085 iq->refetch_glue = 0; 1086 } 1087 1088 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */ 1089 1090 /* This either results in a query restart (CNAME cache response), a 1091 * terminating response (ANSWER), or a cache miss (null). */ 1092 1093 if(qstate->blacklist) { 1094 /* if cache, or anything else, was blacklisted then 1095 * getting older results from cache is a bad idea, no cache */ 1096 verbose(VERB_ALGO, "cache blacklisted, going to the network"); 1097 msg = NULL; 1098 } else if(!qstate->no_cache_lookup) { 1099 msg = dns_cache_lookup(qstate->env, iq->qchase.qname, 1100 iq->qchase.qname_len, iq->qchase.qtype, 1101 iq->qchase.qclass, qstate->query_flags, 1102 qstate->region, qstate->env->scratch); 1103 if(!msg && qstate->env->neg_cache) { 1104 /* lookup in negative cache; may result in 1105 * NOERROR/NODATA or NXDOMAIN answers that need validation */ 1106 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase, 1107 qstate->region, qstate->env->rrset_cache, 1108 qstate->env->scratch_buffer, 1109 *qstate->env->now, 1/*add SOA*/, NULL); 1110 } 1111 /* item taken from cache does not match our query name, thus 1112 * security needs to be re-examined later */ 1113 if(msg && query_dname_compare(qstate->qinfo.qname, 1114 iq->qchase.qname) != 0) 1115 msg->rep->security = sec_status_unchecked; 1116 } 1117 if(msg) { 1118 /* handle positive cache response */ 1119 enum response_type type = response_type_from_cache(msg, 1120 &iq->qchase); 1121 if(verbosity >= VERB_ALGO) { 1122 log_dns_msg("msg from cache lookup", &msg->qinfo, 1123 msg->rep); 1124 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d", 1125 (int)msg->rep->ttl, 1126 (int)msg->rep->prefetch_ttl); 1127 } 1128 1129 if(type == RESPONSE_TYPE_CNAME) { 1130 uint8_t* sname = 0; 1131 size_t slen = 0; 1132 verbose(VERB_ALGO, "returning CNAME response from " 1133 "cache"); 1134 if(!handle_cname_response(qstate, iq, msg, 1135 &sname, &slen)) 1136 return error_response(qstate, id, 1137 LDNS_RCODE_SERVFAIL); 1138 iq->qchase.qname = sname; 1139 iq->qchase.qname_len = slen; 1140 /* This *is* a query restart, even if it is a cheap 1141 * one. */ 1142 iq->dp = NULL; 1143 iq->refetch_glue = 0; 1144 iq->query_restart_count++; 1145 iq->sent_count = 0; 1146 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1147 if(qstate->env->cfg->qname_minimisation) 1148 iq->minimisation_state = INIT_MINIMISE_STATE; 1149 return next_state(iq, INIT_REQUEST_STATE); 1150 } 1151 1152 /* if from cache, NULL, else insert 'cache IP' len=0 */ 1153 if(qstate->reply_origin) 1154 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1155 /* it is an answer, response, to final state */ 1156 verbose(VERB_ALGO, "returning answer from cache."); 1157 iq->response = msg; 1158 return final_state(iq); 1159 } 1160 1161 /* attempt to forward the request */ 1162 if(forward_request(qstate, iq)) 1163 { 1164 if(!iq->dp) { 1165 log_err("alloc failure for forward dp"); 1166 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1167 } 1168 iq->refetch_glue = 0; 1169 iq->minimisation_state = DONOT_MINIMISE_STATE; 1170 /* the request has been forwarded. 1171 * forwarded requests need to be immediately sent to the 1172 * next state, QUERYTARGETS. */ 1173 return next_state(iq, QUERYTARGETS_STATE); 1174 } 1175 1176 /* Resolver Algorithm Step 2 -- find the "best" servers. */ 1177 1178 /* first, adjust for DS queries. To avoid the grandparent problem, 1179 * we just look for the closest set of server to the parent of qname. 1180 * When re-fetching glue we also need to ask the parent. 1181 */ 1182 if(iq->refetch_glue) { 1183 if(!iq->dp) { 1184 log_err("internal or malloc fail: no dp for refetch"); 1185 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1186 } 1187 delname = iq->dp->name; 1188 delnamelen = iq->dp->namelen; 1189 } else { 1190 delname = iq->qchase.qname; 1191 delnamelen = iq->qchase.qname_len; 1192 } 1193 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue || 1194 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) { 1195 /* remove first label from delname, root goes to hints, 1196 * but only to fetch glue, not for qtype=DS. */ 1197 /* also when prefetching an NS record, fetch it again from 1198 * its parent, just as if it expired, so that you do not 1199 * get stuck on an older nameserver that gives old NSrecords */ 1200 if(dname_is_root(delname) && (iq->refetch_glue || 1201 (iq->qchase.qtype == LDNS_RR_TYPE_NS && 1202 qstate->prefetch_leeway))) 1203 delname = NULL; /* go to root priming */ 1204 else dname_remove_label(&delname, &delnamelen); 1205 } 1206 /* delname is the name to lookup a delegation for. If NULL rootprime */ 1207 while(1) { 1208 1209 /* Lookup the delegation in the cache. If null, then the 1210 * cache needs to be primed for the qclass. */ 1211 if(delname) 1212 iq->dp = dns_cache_find_delegation(qstate->env, delname, 1213 delnamelen, iq->qchase.qtype, iq->qchase.qclass, 1214 qstate->region, &iq->deleg_msg, 1215 *qstate->env->now+qstate->prefetch_leeway); 1216 else iq->dp = NULL; 1217 1218 /* If the cache has returned nothing, then we have a 1219 * root priming situation. */ 1220 if(iq->dp == NULL) { 1221 /* if there is a stub, then no root prime needed */ 1222 int r = prime_stub(qstate, iq, id, delname, 1223 iq->qchase.qclass); 1224 if(r == 2) 1225 break; /* got noprime-stub-zone, continue */ 1226 else if(r) 1227 return 0; /* stub prime request made */ 1228 if(forwards_lookup_root(qstate->env->fwds, 1229 iq->qchase.qclass)) { 1230 /* forward zone root, no root prime needed */ 1231 /* fill in some dp - safety belt */ 1232 iq->dp = hints_lookup_root(qstate->env->hints, 1233 iq->qchase.qclass); 1234 if(!iq->dp) { 1235 log_err("internal error: no hints dp"); 1236 return error_response(qstate, id, 1237 LDNS_RCODE_SERVFAIL); 1238 } 1239 iq->dp = delegpt_copy(iq->dp, qstate->region); 1240 if(!iq->dp) { 1241 log_err("out of memory in safety belt"); 1242 return error_response(qstate, id, 1243 LDNS_RCODE_SERVFAIL); 1244 } 1245 return next_state(iq, INIT_REQUEST_2_STATE); 1246 } 1247 /* Note that the result of this will set a new 1248 * DelegationPoint based on the result of priming. */ 1249 if(!prime_root(qstate, iq, id, iq->qchase.qclass)) 1250 return error_response(qstate, id, 1251 LDNS_RCODE_REFUSED); 1252 1253 /* priming creates and sends a subordinate query, with 1254 * this query as the parent. So further processing for 1255 * this event will stop until reactivated by the 1256 * results of priming. */ 1257 return 0; 1258 } 1259 if(!iq->ratelimit_ok && qstate->prefetch_leeway) 1260 iq->ratelimit_ok = 1; /* allow prefetches, this keeps 1261 otherwise valid data in the cache */ 1262 if(!iq->ratelimit_ok && infra_ratelimit_exceeded( 1263 qstate->env->infra_cache, iq->dp->name, 1264 iq->dp->namelen, *qstate->env->now)) { 1265 /* and increment the rate, so that the rate for time 1266 * now will also exceed the rate, keeping cache fresh */ 1267 (void)infra_ratelimit_inc(qstate->env->infra_cache, 1268 iq->dp->name, iq->dp->namelen, 1269 *qstate->env->now); 1270 /* see if we are passed through with slip factor */ 1271 if(qstate->env->cfg->ratelimit_factor != 0 && 1272 ub_random_max(qstate->env->rnd, 1273 qstate->env->cfg->ratelimit_factor) == 1) { 1274 iq->ratelimit_ok = 1; 1275 log_nametypeclass(VERB_ALGO, "ratelimit allowed through for " 1276 "delegation point", iq->dp->name, 1277 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN); 1278 } else { 1279 log_nametypeclass(VERB_ALGO, "ratelimit exceeded with " 1280 "delegation point", iq->dp->name, 1281 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN); 1282 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1283 } 1284 } 1285 1286 /* see if this dp not useless. 1287 * It is useless if: 1288 * o all NS items are required glue. 1289 * or the query is for NS item that is required glue. 1290 * o no addresses are provided. 1291 * o RD qflag is on. 1292 * Instead, go up one level, and try to get even further 1293 * If the root was useless, use safety belt information. 1294 * Only check cache returns, because replies for servers 1295 * could be useless but lead to loops (bumping into the 1296 * same server reply) if useless-checked. 1297 */ 1298 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, 1299 iq->dp)) { 1300 if(dname_is_root(iq->dp->name)) { 1301 /* use safety belt */ 1302 verbose(VERB_QUERY, "Cache has root NS but " 1303 "no addresses. Fallback to the safety belt."); 1304 iq->dp = hints_lookup_root(qstate->env->hints, 1305 iq->qchase.qclass); 1306 /* note deleg_msg is from previous lookup, 1307 * but RD is on, so it is not used */ 1308 if(!iq->dp) { 1309 log_err("internal error: no hints dp"); 1310 return error_response(qstate, id, 1311 LDNS_RCODE_REFUSED); 1312 } 1313 iq->dp = delegpt_copy(iq->dp, qstate->region); 1314 if(!iq->dp) { 1315 log_err("out of memory in safety belt"); 1316 return error_response(qstate, id, 1317 LDNS_RCODE_SERVFAIL); 1318 } 1319 break; 1320 } else { 1321 verbose(VERB_ALGO, 1322 "cache delegation was useless:"); 1323 delegpt_log(VERB_ALGO, iq->dp); 1324 /* go up */ 1325 delname = iq->dp->name; 1326 delnamelen = iq->dp->namelen; 1327 dname_remove_label(&delname, &delnamelen); 1328 } 1329 } else break; 1330 } 1331 1332 verbose(VERB_ALGO, "cache delegation returns delegpt"); 1333 delegpt_log(VERB_ALGO, iq->dp); 1334 1335 /* Otherwise, set the current delegation point and move on to the 1336 * next state. */ 1337 return next_state(iq, INIT_REQUEST_2_STATE); 1338 } 1339 1340 /** 1341 * Process the second part of the initial request handling. This state 1342 * basically exists so that queries that generate root priming events have 1343 * the same init processing as ones that do not. Request events that reach 1344 * this state must have a valid currentDelegationPoint set. 1345 * 1346 * This part is primarly handling stub zone priming. Events that reach this 1347 * state must have a current delegation point. 1348 * 1349 * @param qstate: query state. 1350 * @param iq: iterator query state. 1351 * @param id: module id. 1352 * @return true if the event needs more request processing immediately, 1353 * false if not. 1354 */ 1355 static int 1356 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq, 1357 int id) 1358 { 1359 uint8_t* delname; 1360 size_t delnamelen; 1361 log_query_info(VERB_QUERY, "resolving (init part 2): ", 1362 &qstate->qinfo); 1363 1364 if(iq->refetch_glue) { 1365 if(!iq->dp) { 1366 log_err("internal or malloc fail: no dp for refetch"); 1367 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1368 } 1369 delname = iq->dp->name; 1370 delnamelen = iq->dp->namelen; 1371 } else { 1372 delname = iq->qchase.qname; 1373 delnamelen = iq->qchase.qname_len; 1374 } 1375 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) { 1376 if(!dname_is_root(delname)) 1377 dname_remove_label(&delname, &delnamelen); 1378 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */ 1379 } 1380 /* Check to see if we need to prime a stub zone. */ 1381 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) { 1382 /* A priming sub request was made */ 1383 return 0; 1384 } 1385 1386 /* most events just get forwarded to the next state. */ 1387 return next_state(iq, INIT_REQUEST_3_STATE); 1388 } 1389 1390 /** 1391 * Process the third part of the initial request handling. This state exists 1392 * as a separate state so that queries that generate stub priming events 1393 * will get the tail end of the init process but not repeat the stub priming 1394 * check. 1395 * 1396 * @param qstate: query state. 1397 * @param iq: iterator query state. 1398 * @param id: module id. 1399 * @return true, advancing the event to the QUERYTARGETS_STATE. 1400 */ 1401 static int 1402 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq, 1403 int id) 1404 { 1405 log_query_info(VERB_QUERY, "resolving (init part 3): ", 1406 &qstate->qinfo); 1407 /* if the cache reply dp equals a validation anchor or msg has DS, 1408 * then DNSSEC RRSIGs are expected in the reply */ 1409 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp, 1410 iq->deleg_msg, iq->qchase.qclass); 1411 1412 /* If the RD flag wasn't set, then we just finish with the 1413 * cached referral as the response. */ 1414 if(!(qstate->query_flags & BIT_RD) && iq->deleg_msg) { 1415 iq->response = iq->deleg_msg; 1416 if(verbosity >= VERB_ALGO && iq->response) 1417 log_dns_msg("no RD requested, using delegation msg", 1418 &iq->response->qinfo, iq->response->rep); 1419 if(qstate->reply_origin) 1420 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1421 return final_state(iq); 1422 } 1423 /* After this point, unset the RD flag -- this query is going to 1424 * be sent to an auth. server. */ 1425 iq->chase_flags &= ~BIT_RD; 1426 1427 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */ 1428 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 1429 !(qstate->query_flags&BIT_CD)) { 1430 generate_dnskey_prefetch(qstate, iq, id); 1431 fptr_ok(fptr_whitelist_modenv_detach_subs( 1432 qstate->env->detach_subs)); 1433 (*qstate->env->detach_subs)(qstate); 1434 } 1435 1436 /* Jump to the next state. */ 1437 return next_state(iq, QUERYTARGETS_STATE); 1438 } 1439 1440 /** 1441 * Given a basic query, generate a parent-side "target" query. 1442 * These are subordinate queries for missing delegation point target addresses, 1443 * for which only the parent of the delegation provides correct IP addresses. 1444 * 1445 * @param qstate: query state. 1446 * @param iq: iterator query state. 1447 * @param id: module id. 1448 * @param name: target qname. 1449 * @param namelen: target qname length. 1450 * @param qtype: target qtype (either A or AAAA). 1451 * @param qclass: target qclass. 1452 * @return true on success, false on failure. 1453 */ 1454 static int 1455 generate_parentside_target_query(struct module_qstate* qstate, 1456 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen, 1457 uint16_t qtype, uint16_t qclass) 1458 { 1459 struct module_qstate* subq; 1460 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1461 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1462 return 0; 1463 if(subq) { 1464 struct iter_qstate* subiq = 1465 (struct iter_qstate*)subq->minfo[id]; 1466 /* blacklist the cache - we want to fetch parent stuff */ 1467 sock_list_insert(&subq->blacklist, NULL, 0, subq->region); 1468 subiq->query_for_pside_glue = 1; 1469 if(dname_subdomain_c(name, iq->dp->name)) { 1470 subiq->dp = delegpt_copy(iq->dp, subq->region); 1471 subiq->dnssec_expected = iter_indicates_dnssec( 1472 qstate->env, subiq->dp, NULL, 1473 subq->qinfo.qclass); 1474 subiq->refetch_glue = 1; 1475 } else { 1476 subiq->dp = dns_cache_find_delegation(qstate->env, 1477 name, namelen, qtype, qclass, subq->region, 1478 &subiq->deleg_msg, 1479 *qstate->env->now+subq->prefetch_leeway); 1480 /* if no dp, then it's from root, refetch unneeded */ 1481 if(subiq->dp) { 1482 subiq->dnssec_expected = iter_indicates_dnssec( 1483 qstate->env, subiq->dp, NULL, 1484 subq->qinfo.qclass); 1485 subiq->refetch_glue = 1; 1486 } 1487 } 1488 } 1489 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass); 1490 return 1; 1491 } 1492 1493 /** 1494 * Given a basic query, generate a "target" query. These are subordinate 1495 * queries for missing delegation point target addresses. 1496 * 1497 * @param qstate: query state. 1498 * @param iq: iterator query state. 1499 * @param id: module id. 1500 * @param name: target qname. 1501 * @param namelen: target qname length. 1502 * @param qtype: target qtype (either A or AAAA). 1503 * @param qclass: target qclass. 1504 * @return true on success, false on failure. 1505 */ 1506 static int 1507 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq, 1508 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass) 1509 { 1510 struct module_qstate* subq; 1511 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1512 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1513 return 0; 1514 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass); 1515 return 1; 1516 } 1517 1518 /** 1519 * Given an event at a certain state, generate zero or more target queries 1520 * for it's current delegation point. 1521 * 1522 * @param qstate: query state. 1523 * @param iq: iterator query state. 1524 * @param ie: iterator shared global environment. 1525 * @param id: module id. 1526 * @param maxtargets: The maximum number of targets to query for. 1527 * if it is negative, there is no maximum number of targets. 1528 * @param num: returns the number of queries generated and processed, 1529 * which may be zero if there were no missing targets. 1530 * @return false on error. 1531 */ 1532 static int 1533 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq, 1534 struct iter_env* ie, int id, int maxtargets, int* num) 1535 { 1536 int query_count = 0; 1537 struct delegpt_ns* ns; 1538 int missing; 1539 int toget = 0; 1540 1541 if(iq->depth == ie->max_dependency_depth) 1542 return 0; 1543 if(iq->depth > 0 && iq->target_count && 1544 iq->target_count[1] > MAX_TARGET_COUNT) { 1545 char s[LDNS_MAX_DOMAINLEN+1]; 1546 dname_str(qstate->qinfo.qname, s); 1547 verbose(VERB_QUERY, "request %s has exceeded the maximum " 1548 "number of glue fetches %d", s, iq->target_count[1]); 1549 return 0; 1550 } 1551 1552 iter_mark_cycle_targets(qstate, iq->dp); 1553 missing = (int)delegpt_count_missing_targets(iq->dp); 1554 log_assert(maxtargets != 0); /* that would not be useful */ 1555 1556 /* Generate target requests. Basically, any missing targets 1557 * are queried for here, regardless if it is necessary to do 1558 * so to continue processing. */ 1559 if(maxtargets < 0 || maxtargets > missing) 1560 toget = missing; 1561 else toget = maxtargets; 1562 if(toget == 0) { 1563 *num = 0; 1564 return 1; 1565 } 1566 /* select 'toget' items from the total of 'missing' items */ 1567 log_assert(toget <= missing); 1568 1569 /* loop over missing targets */ 1570 for(ns = iq->dp->nslist; ns; ns = ns->next) { 1571 if(ns->resolved) 1572 continue; 1573 1574 /* randomly select this item with probability toget/missing */ 1575 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) { 1576 /* do not select this one, next; select toget number 1577 * of items from a list one less in size */ 1578 missing --; 1579 continue; 1580 } 1581 1582 if(ie->supports_ipv6 && !ns->got6) { 1583 /* Send the AAAA request. */ 1584 if(!generate_target_query(qstate, iq, id, 1585 ns->name, ns->namelen, 1586 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { 1587 *num = query_count; 1588 if(query_count > 0) 1589 qstate->ext_state[id] = module_wait_subquery; 1590 return 0; 1591 } 1592 query_count++; 1593 } 1594 /* Send the A request. */ 1595 if(ie->supports_ipv4 && !ns->got4) { 1596 if(!generate_target_query(qstate, iq, id, 1597 ns->name, ns->namelen, 1598 LDNS_RR_TYPE_A, iq->qchase.qclass)) { 1599 *num = query_count; 1600 if(query_count > 0) 1601 qstate->ext_state[id] = module_wait_subquery; 1602 return 0; 1603 } 1604 query_count++; 1605 } 1606 1607 /* mark this target as in progress. */ 1608 ns->resolved = 1; 1609 missing--; 1610 toget--; 1611 if(toget == 0) 1612 break; 1613 } 1614 *num = query_count; 1615 if(query_count > 0) 1616 qstate->ext_state[id] = module_wait_subquery; 1617 1618 return 1; 1619 } 1620 1621 /** 1622 * Called by processQueryTargets when it would like extra targets to query 1623 * but it seems to be out of options. At last resort some less appealing 1624 * options are explored. If there are no more options, the result is SERVFAIL 1625 * 1626 * @param qstate: query state. 1627 * @param iq: iterator query state. 1628 * @param ie: iterator shared global environment. 1629 * @param id: module id. 1630 * @return true if the event requires more request processing immediately, 1631 * false if not. 1632 */ 1633 static int 1634 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq, 1635 struct iter_env* ie, int id) 1636 { 1637 struct delegpt_ns* ns; 1638 int query_count = 0; 1639 verbose(VERB_ALGO, "No more query targets, attempting last resort"); 1640 log_assert(iq->dp); 1641 1642 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, 1643 iq->qchase.qclass)) { 1644 /* fail -- no more targets, no more hope of targets, no hope 1645 * of a response. */ 1646 verbose(VERB_QUERY, "configured stub or forward servers failed -- returning SERVFAIL"); 1647 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1648 } 1649 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) { 1650 struct delegpt* p = hints_lookup_root(qstate->env->hints, 1651 iq->qchase.qclass); 1652 if(p) { 1653 struct delegpt_ns* ns; 1654 struct delegpt_addr* a; 1655 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1656 for(ns = p->nslist; ns; ns=ns->next) { 1657 (void)delegpt_add_ns(iq->dp, qstate->region, 1658 ns->name, ns->lame); 1659 } 1660 for(a = p->target_list; a; a=a->next_target) { 1661 (void)delegpt_add_addr(iq->dp, qstate->region, 1662 &a->addr, a->addrlen, a->bogus, 1663 a->lame); 1664 } 1665 } 1666 iq->dp->has_parent_side_NS = 1; 1667 } else if(!iq->dp->has_parent_side_NS) { 1668 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp, 1669 qstate->region, &qstate->qinfo) 1670 || !iq->dp->has_parent_side_NS) { 1671 /* if: malloc failure in lookup go up to try */ 1672 /* if: no parent NS in cache - go up one level */ 1673 verbose(VERB_ALGO, "try to grab parent NS"); 1674 iq->store_parent_NS = iq->dp; 1675 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1676 iq->deleg_msg = NULL; 1677 iq->refetch_glue = 1; 1678 iq->query_restart_count++; 1679 iq->sent_count = 0; 1680 if(qstate->env->cfg->qname_minimisation) 1681 iq->minimisation_state = INIT_MINIMISE_STATE; 1682 return next_state(iq, INIT_REQUEST_STATE); 1683 } 1684 } 1685 /* see if that makes new names available */ 1686 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 1687 qstate->region, iq->dp)) 1688 log_err("out of memory in cache_fill_missing"); 1689 if(iq->dp->usable_list) { 1690 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache"); 1691 return next_state(iq, QUERYTARGETS_STATE); 1692 } 1693 /* try to fill out parent glue from cache */ 1694 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp, 1695 qstate->region, &qstate->qinfo)) { 1696 /* got parent stuff from cache, see if we can continue */ 1697 verbose(VERB_ALGO, "try parent-side glue from cache"); 1698 return next_state(iq, QUERYTARGETS_STATE); 1699 } 1700 /* query for an extra name added by the parent-NS record */ 1701 if(delegpt_count_missing_targets(iq->dp) > 0) { 1702 int qs = 0; 1703 verbose(VERB_ALGO, "try parent-side target name"); 1704 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) { 1705 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1706 } 1707 iq->num_target_queries += qs; 1708 target_count_increase(iq, qs); 1709 if(qs != 0) { 1710 qstate->ext_state[id] = module_wait_subquery; 1711 return 0; /* and wait for them */ 1712 } 1713 } 1714 if(iq->depth == ie->max_dependency_depth) { 1715 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail"); 1716 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1717 } 1718 if(iq->depth > 0 && iq->target_count && 1719 iq->target_count[1] > MAX_TARGET_COUNT) { 1720 char s[LDNS_MAX_DOMAINLEN+1]; 1721 dname_str(qstate->qinfo.qname, s); 1722 verbose(VERB_QUERY, "request %s has exceeded the maximum " 1723 "number of glue fetches %d", s, iq->target_count[1]); 1724 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1725 } 1726 /* mark cycle targets for parent-side lookups */ 1727 iter_mark_pside_cycle_targets(qstate, iq->dp); 1728 /* see if we can issue queries to get nameserver addresses */ 1729 /* this lookup is not randomized, but sequential. */ 1730 for(ns = iq->dp->nslist; ns; ns = ns->next) { 1731 /* if this nameserver is at a delegation point, but that 1732 * delegation point is a stub and we cannot go higher, skip*/ 1733 if( ((ie->supports_ipv6 && !ns->done_pside6) || 1734 (ie->supports_ipv4 && !ns->done_pside4)) && 1735 !can_have_last_resort(qstate->env, ns->name, ns->namelen, 1736 iq->qchase.qclass)) { 1737 log_nametypeclass(VERB_ALGO, "cannot pside lookup ns " 1738 "because it is also a stub/forward,", 1739 ns->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 1740 if(ie->supports_ipv6) ns->done_pside6 = 1; 1741 if(ie->supports_ipv4) ns->done_pside4 = 1; 1742 continue; 1743 } 1744 /* query for parent-side A and AAAA for nameservers */ 1745 if(ie->supports_ipv6 && !ns->done_pside6) { 1746 /* Send the AAAA request. */ 1747 if(!generate_parentside_target_query(qstate, iq, id, 1748 ns->name, ns->namelen, 1749 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) 1750 return error_response(qstate, id, 1751 LDNS_RCODE_SERVFAIL); 1752 ns->done_pside6 = 1; 1753 query_count++; 1754 } 1755 if(ie->supports_ipv4 && !ns->done_pside4) { 1756 /* Send the A request. */ 1757 if(!generate_parentside_target_query(qstate, iq, id, 1758 ns->name, ns->namelen, 1759 LDNS_RR_TYPE_A, iq->qchase.qclass)) 1760 return error_response(qstate, id, 1761 LDNS_RCODE_SERVFAIL); 1762 ns->done_pside4 = 1; 1763 query_count++; 1764 } 1765 if(query_count != 0) { /* suspend to await results */ 1766 verbose(VERB_ALGO, "try parent-side glue lookup"); 1767 iq->num_target_queries += query_count; 1768 target_count_increase(iq, query_count); 1769 qstate->ext_state[id] = module_wait_subquery; 1770 return 0; 1771 } 1772 } 1773 1774 /* if this was a parent-side glue query itself, then store that 1775 * failure in cache. */ 1776 if(!qstate->no_cache_store && iq->query_for_pside_glue 1777 && !iq->pside_glue) 1778 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 1779 iq->deleg_msg?iq->deleg_msg->rep: 1780 (iq->response?iq->response->rep:NULL)); 1781 1782 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL"); 1783 /* fail -- no more targets, no more hope of targets, no hope 1784 * of a response. */ 1785 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1786 } 1787 1788 /** 1789 * Try to find the NS record set that will resolve a qtype DS query. Due 1790 * to grandparent/grandchild reasons we did not get a proper lookup right 1791 * away. We need to create type NS queries until we get the right parent 1792 * for this lookup. We remove labels from the query to find the right point. 1793 * If we end up at the old dp name, then there is no solution. 1794 * 1795 * @param qstate: query state. 1796 * @param iq: iterator query state. 1797 * @param id: module id. 1798 * @return true if the event requires more immediate processing, false if 1799 * not. This is generally only true when forwarding the request to 1800 * the final state (i.e., on answer). 1801 */ 1802 static int 1803 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id) 1804 { 1805 struct module_qstate* subq = NULL; 1806 verbose(VERB_ALGO, "processDSNSFind"); 1807 1808 if(!iq->dsns_point) { 1809 /* initialize */ 1810 iq->dsns_point = iq->qchase.qname; 1811 iq->dsns_point_len = iq->qchase.qname_len; 1812 } 1813 /* robustcheck for internal error: we are not underneath the dp */ 1814 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) { 1815 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1816 } 1817 1818 /* go up one (more) step, until we hit the dp, if so, end */ 1819 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len); 1820 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) { 1821 /* there was no inbetween nameserver, use the old delegation 1822 * point again. And this time, because dsns_point is nonNULL 1823 * we are going to accept the (bad) result */ 1824 iq->state = QUERYTARGETS_STATE; 1825 return 1; 1826 } 1827 iq->state = DSNS_FIND_STATE; 1828 1829 /* spawn NS lookup (validation not needed, this is for DS lookup) */ 1830 log_nametypeclass(VERB_ALGO, "fetch nameservers", 1831 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass); 1832 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len, 1833 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 1834 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 1835 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1836 } 1837 1838 return 0; 1839 } 1840 1841 /** 1842 * This is the request event state where the request will be sent to one of 1843 * its current query targets. This state also handles issuing target lookup 1844 * queries for missing target IP addresses. Queries typically iterate on 1845 * this state, both when they are just trying different targets for a given 1846 * delegation point, and when they change delegation points. This state 1847 * roughly corresponds to RFC 1034 algorithm steps 3 and 4. 1848 * 1849 * @param qstate: query state. 1850 * @param iq: iterator query state. 1851 * @param ie: iterator shared global environment. 1852 * @param id: module id. 1853 * @return true if the event requires more request processing immediately, 1854 * false if not. This state only returns true when it is generating 1855 * a SERVFAIL response because the query has hit a dead end. 1856 */ 1857 static int 1858 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq, 1859 struct iter_env* ie, int id) 1860 { 1861 int tf_policy; 1862 struct delegpt_addr* target; 1863 struct outbound_entry* outq; 1864 1865 /* NOTE: a request will encounter this state for each target it 1866 * needs to send a query to. That is, at least one per referral, 1867 * more if some targets timeout or return throwaway answers. */ 1868 1869 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo); 1870 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, " 1871 "currentqueries %d sentcount %d", iq->num_target_queries, 1872 iq->num_current_queries, iq->sent_count); 1873 1874 /* Make sure that we haven't run away */ 1875 /* FIXME: is this check even necessary? */ 1876 if(iq->referral_count > MAX_REFERRAL_COUNT) { 1877 verbose(VERB_QUERY, "request has exceeded the maximum " 1878 "number of referrrals with %d", iq->referral_count); 1879 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1880 } 1881 if(iq->sent_count > MAX_SENT_COUNT) { 1882 verbose(VERB_QUERY, "request has exceeded the maximum " 1883 "number of sends with %d", iq->sent_count); 1884 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1885 } 1886 1887 /* Make sure we have a delegation point, otherwise priming failed 1888 * or another failure occurred */ 1889 if(!iq->dp) { 1890 verbose(VERB_QUERY, "Failed to get a delegation, giving up"); 1891 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1892 } 1893 if(!ie->supports_ipv6) 1894 delegpt_no_ipv6(iq->dp); 1895 if(!ie->supports_ipv4) 1896 delegpt_no_ipv4(iq->dp); 1897 delegpt_log(VERB_ALGO, iq->dp); 1898 1899 if(iq->num_current_queries>0) { 1900 /* already busy answering a query, this restart is because 1901 * more delegpt addrs became available, wait for existing 1902 * query. */ 1903 verbose(VERB_ALGO, "woke up, but wait for outstanding query"); 1904 qstate->ext_state[id] = module_wait_reply; 1905 return 0; 1906 } 1907 1908 tf_policy = 0; 1909 /* < not <=, because although the array is large enough for <=, the 1910 * generated query will immediately be discarded due to depth and 1911 * that servfail is cached, which is not good as opportunism goes. */ 1912 if(iq->depth < ie->max_dependency_depth 1913 && iq->sent_count < TARGET_FETCH_STOP) { 1914 tf_policy = ie->target_fetch_policy[iq->depth]; 1915 } 1916 1917 /* if in 0x20 fallback get as many targets as possible */ 1918 if(iq->caps_fallback) { 1919 int extra = 0; 1920 size_t naddr, nres, navail; 1921 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) { 1922 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1923 } 1924 iq->num_target_queries += extra; 1925 target_count_increase(iq, extra); 1926 if(iq->num_target_queries > 0) { 1927 /* wait to get all targets, we want to try em */ 1928 verbose(VERB_ALGO, "wait for all targets for fallback"); 1929 qstate->ext_state[id] = module_wait_reply; 1930 return 0; 1931 } 1932 /* did we do enough fallback queries already? */ 1933 delegpt_count_addr(iq->dp, &naddr, &nres, &navail); 1934 /* the current caps_server is the number of fallbacks sent. 1935 * the original query is one that matched too, so we have 1936 * caps_server+1 number of matching queries now */ 1937 if(iq->caps_server+1 >= naddr*3 || 1938 iq->caps_server*2+2 >= MAX_SENT_COUNT) { 1939 /* *2 on sentcount check because ipv6 may fail */ 1940 /* we're done, process the response */ 1941 verbose(VERB_ALGO, "0x20 fallback had %d responses " 1942 "match for %d wanted, done.", 1943 (int)iq->caps_server+1, (int)naddr*3); 1944 iq->response = iq->caps_response; 1945 iq->caps_fallback = 0; 1946 iter_dec_attempts(iq->dp, 3); /* space for fallback */ 1947 iq->num_current_queries++; /* RespState decrements it*/ 1948 iq->referral_count++; /* make sure we don't loop */ 1949 iq->sent_count = 0; 1950 iq->state = QUERY_RESP_STATE; 1951 return 1; 1952 } 1953 verbose(VERB_ALGO, "0x20 fallback number %d", 1954 (int)iq->caps_server); 1955 1956 /* if there is a policy to fetch missing targets 1957 * opportunistically, do it. we rely on the fact that once a 1958 * query (or queries) for a missing name have been issued, 1959 * they will not show up again. */ 1960 } else if(tf_policy != 0) { 1961 int extra = 0; 1962 verbose(VERB_ALGO, "attempt to get extra %d targets", 1963 tf_policy); 1964 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra); 1965 /* errors ignored, these targets are not strictly necessary for 1966 * this result, we do not have to reply with SERVFAIL */ 1967 iq->num_target_queries += extra; 1968 target_count_increase(iq, extra); 1969 } 1970 1971 /* Add the current set of unused targets to our queue. */ 1972 delegpt_add_unused_targets(iq->dp); 1973 1974 /* Select the next usable target, filtering out unsuitable targets. */ 1975 target = iter_server_selection(ie, qstate->env, iq->dp, 1976 iq->dp->name, iq->dp->namelen, iq->qchase.qtype, 1977 &iq->dnssec_lame_query, &iq->chase_to_rd, 1978 iq->num_target_queries, qstate->blacklist); 1979 1980 /* If no usable target was selected... */ 1981 if(!target) { 1982 /* Here we distinguish between three states: generate a new 1983 * target query, just wait, or quit (with a SERVFAIL). 1984 * We have the following information: number of active 1985 * target queries, number of active current queries, 1986 * the presence of missing targets at this delegation 1987 * point, and the given query target policy. */ 1988 1989 /* Check for the wait condition. If this is true, then 1990 * an action must be taken. */ 1991 if(iq->num_target_queries==0 && iq->num_current_queries==0) { 1992 /* If there is nothing to wait for, then we need 1993 * to distinguish between generating (a) new target 1994 * query, or failing. */ 1995 if(delegpt_count_missing_targets(iq->dp) > 0) { 1996 int qs = 0; 1997 verbose(VERB_ALGO, "querying for next " 1998 "missing target"); 1999 if(!query_for_targets(qstate, iq, ie, id, 2000 1, &qs)) { 2001 return error_response(qstate, id, 2002 LDNS_RCODE_SERVFAIL); 2003 } 2004 if(qs == 0 && 2005 delegpt_count_missing_targets(iq->dp) == 0){ 2006 /* it looked like there were missing 2007 * targets, but they did not turn up. 2008 * Try the bad choices again (if any), 2009 * when we get back here missing==0, 2010 * so this is not a loop. */ 2011 return 1; 2012 } 2013 iq->num_target_queries += qs; 2014 target_count_increase(iq, qs); 2015 } 2016 /* Since a target query might have been made, we 2017 * need to check again. */ 2018 if(iq->num_target_queries == 0) { 2019 /* if in capsforid fallback, instead of last 2020 * resort, we agree with the current reply 2021 * we have (if any) (our count of addrs bad)*/ 2022 if(iq->caps_fallback && iq->caps_reply) { 2023 /* we're done, process the response */ 2024 verbose(VERB_ALGO, "0x20 fallback had %d responses, " 2025 "but no more servers except " 2026 "last resort, done.", 2027 (int)iq->caps_server+1); 2028 iq->response = iq->caps_response; 2029 iq->caps_fallback = 0; 2030 iter_dec_attempts(iq->dp, 3); /* space for fallback */ 2031 iq->num_current_queries++; /* RespState decrements it*/ 2032 iq->referral_count++; /* make sure we don't loop */ 2033 iq->sent_count = 0; 2034 iq->state = QUERY_RESP_STATE; 2035 return 1; 2036 } 2037 return processLastResort(qstate, iq, ie, id); 2038 } 2039 } 2040 2041 /* otherwise, we have no current targets, so submerge 2042 * until one of the target or direct queries return. */ 2043 if(iq->num_target_queries>0 && iq->num_current_queries>0) { 2044 verbose(VERB_ALGO, "no current targets -- waiting " 2045 "for %d targets to resolve or %d outstanding" 2046 " queries to respond", iq->num_target_queries, 2047 iq->num_current_queries); 2048 qstate->ext_state[id] = module_wait_reply; 2049 } else if(iq->num_target_queries>0) { 2050 verbose(VERB_ALGO, "no current targets -- waiting " 2051 "for %d targets to resolve.", 2052 iq->num_target_queries); 2053 qstate->ext_state[id] = module_wait_subquery; 2054 } else { 2055 verbose(VERB_ALGO, "no current targets -- waiting " 2056 "for %d outstanding queries to respond.", 2057 iq->num_current_queries); 2058 qstate->ext_state[id] = module_wait_reply; 2059 } 2060 return 0; 2061 } 2062 2063 /* if not forwarding, check ratelimits per delegationpoint name */ 2064 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) { 2065 if(!infra_ratelimit_inc(qstate->env->infra_cache, iq->dp->name, 2066 iq->dp->namelen, *qstate->env->now)) { 2067 verbose(VERB_ALGO, "query exceeded ratelimits"); 2068 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2069 } 2070 } 2071 2072 if(iq->minimisation_state == INIT_MINIMISE_STATE) { 2073 /* (Re)set qinfo_out to (new) delegation point, except when 2074 * qinfo_out is already a subdomain of dp. This happens when 2075 * increasing by more than one label at once (QNAMEs with more 2076 * than MAX_MINIMISE_COUNT labels). */ 2077 if(!(iq->qinfo_out.qname_len 2078 && dname_subdomain_c(iq->qchase.qname, 2079 iq->qinfo_out.qname) 2080 && dname_subdomain_c(iq->qinfo_out.qname, 2081 iq->dp->name))) { 2082 iq->qinfo_out.qname = iq->dp->name; 2083 iq->qinfo_out.qname_len = iq->dp->namelen; 2084 iq->qinfo_out.qtype = LDNS_RR_TYPE_A; 2085 iq->qinfo_out.qclass = iq->qchase.qclass; 2086 iq->qinfo_out.local_alias = NULL; 2087 iq->minimise_count = 0; 2088 } 2089 2090 iq->minimisation_state = MINIMISE_STATE; 2091 } 2092 if(iq->minimisation_state == MINIMISE_STATE) { 2093 int qchaselabs = dname_count_labels(iq->qchase.qname); 2094 int labdiff = qchaselabs - 2095 dname_count_labels(iq->qinfo_out.qname); 2096 2097 iq->qinfo_out.qname = iq->qchase.qname; 2098 iq->qinfo_out.qname_len = iq->qchase.qname_len; 2099 iq->minimise_count++; 2100 iq->minimise_timeout_count = 0; 2101 2102 iter_dec_attempts(iq->dp, 1); 2103 2104 /* Limit number of iterations for QNAMEs with more 2105 * than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB 2106 * labels of QNAME always individually. 2107 */ 2108 if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 && 2109 iq->minimise_count > MINIMISE_ONE_LAB) { 2110 if(iq->minimise_count < MAX_MINIMISE_COUNT) { 2111 int multilabs = qchaselabs - 1 - 2112 MINIMISE_ONE_LAB; 2113 int extralabs = multilabs / 2114 MINIMISE_MULTIPLE_LABS; 2115 2116 if (MAX_MINIMISE_COUNT - iq->minimise_count >= 2117 multilabs % MINIMISE_MULTIPLE_LABS) 2118 /* Default behaviour is to add 1 label 2119 * every iteration. Therefore, decrement 2120 * the extralabs by 1 */ 2121 extralabs--; 2122 if (extralabs < labdiff) 2123 labdiff -= extralabs; 2124 else 2125 labdiff = 1; 2126 } 2127 /* Last minimised iteration, send all labels with 2128 * QTYPE=NS */ 2129 else 2130 labdiff = 1; 2131 } 2132 2133 if(labdiff > 1) { 2134 verbose(VERB_QUERY, "removing %d labels", labdiff-1); 2135 dname_remove_labels(&iq->qinfo_out.qname, 2136 &iq->qinfo_out.qname_len, 2137 labdiff-1); 2138 } 2139 if(labdiff < 1 || (labdiff < 2 2140 && (iq->qchase.qtype == LDNS_RR_TYPE_DS 2141 || iq->qchase.qtype == LDNS_RR_TYPE_A))) 2142 /* Stop minimising this query, resolve "as usual" */ 2143 iq->minimisation_state = DONOT_MINIMISE_STATE; 2144 else if(!qstate->no_cache_lookup) { 2145 struct dns_msg* msg = dns_cache_lookup(qstate->env, 2146 iq->qinfo_out.qname, iq->qinfo_out.qname_len, 2147 iq->qinfo_out.qtype, iq->qinfo_out.qclass, 2148 qstate->query_flags, qstate->region, 2149 qstate->env->scratch); 2150 if(msg && msg->rep->an_numrrsets == 0 2151 && FLAGS_GET_RCODE(msg->rep->flags) == 2152 LDNS_RCODE_NOERROR) 2153 /* no need to send query if it is already 2154 * cached as NOERROR/NODATA */ 2155 return 1; 2156 } 2157 } 2158 if(iq->minimisation_state == SKIP_MINIMISE_STATE) { 2159 iq->minimise_timeout_count++; 2160 if(iq->minimise_timeout_count < MAX_MINIMISE_TIMEOUT_COUNT) 2161 /* Do not increment qname, continue incrementing next 2162 * iteration */ 2163 iq->minimisation_state = MINIMISE_STATE; 2164 else if(!qstate->env->cfg->qname_minimisation_strict) 2165 /* Too many time-outs detected for this QNAME and QTYPE. 2166 * We give up, disable QNAME minimisation. */ 2167 iq->minimisation_state = DONOT_MINIMISE_STATE; 2168 } 2169 if(iq->minimisation_state == DONOT_MINIMISE_STATE) 2170 iq->qinfo_out = iq->qchase; 2171 2172 /* We have a valid target. */ 2173 if(verbosity >= VERB_QUERY) { 2174 log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out); 2175 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name, 2176 &target->addr, target->addrlen); 2177 verbose(VERB_ALGO, "dnssec status: %s%s", 2178 iq->dnssec_expected?"expected": "not expected", 2179 iq->dnssec_lame_query?" but lame_query anyway": ""); 2180 } 2181 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query)); 2182 outq = (*qstate->env->send_query)(&iq->qinfo_out, 2183 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), 2184 /* unset CD if to forwarder(RD set) and not dnssec retry 2185 * (blacklist nonempty) and no trust-anchors are configured 2186 * above the qname or on the first attempt when dnssec is on */ 2187 EDNS_DO| ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&& 2188 !qstate->blacklist&&(!iter_indicates_dnssec_fwd(qstate->env, 2189 &iq->qinfo_out)||target->attempts==1)?0:BIT_CD), 2190 iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted( 2191 ie, iq), &target->addr, target->addrlen, 2192 iq->dp->name, iq->dp->namelen, 2193 (iq->dp->ssl_upstream || qstate->env->cfg->ssl_upstream), qstate); 2194 if(!outq) { 2195 log_addr(VERB_DETAIL, "error sending query to auth server", 2196 &target->addr, target->addrlen); 2197 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) 2198 infra_ratelimit_dec(qstate->env->infra_cache, iq->dp->name, 2199 iq->dp->namelen, *qstate->env->now); 2200 return next_state(iq, QUERYTARGETS_STATE); 2201 } 2202 outbound_list_insert(&iq->outlist, outq); 2203 iq->num_current_queries++; 2204 iq->sent_count++; 2205 qstate->ext_state[id] = module_wait_reply; 2206 2207 return 0; 2208 } 2209 2210 /** find NS rrset in given list */ 2211 static struct ub_packed_rrset_key* 2212 find_NS(struct reply_info* rep, size_t from, size_t to) 2213 { 2214 size_t i; 2215 for(i=from; i<to; i++) { 2216 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) 2217 return rep->rrsets[i]; 2218 } 2219 return NULL; 2220 } 2221 2222 2223 /** 2224 * Process the query response. All queries end up at this state first. This 2225 * process generally consists of analyzing the response and routing the 2226 * event to the next state (either bouncing it back to a request state, or 2227 * terminating the processing for this event). 2228 * 2229 * @param qstate: query state. 2230 * @param iq: iterator query state. 2231 * @param id: module id. 2232 * @return true if the event requires more immediate processing, false if 2233 * not. This is generally only true when forwarding the request to 2234 * the final state (i.e., on answer). 2235 */ 2236 static int 2237 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq, 2238 int id) 2239 { 2240 int dnsseclame = 0; 2241 enum response_type type; 2242 iq->num_current_queries--; 2243 2244 if(!inplace_cb_query_response_call(qstate->env, qstate, iq->response)) 2245 log_err("unable to call query_response callback"); 2246 2247 if(iq->response == NULL) { 2248 /* Don't increment qname when QNAME minimisation is enabled */ 2249 if(qstate->env->cfg->qname_minimisation) 2250 iq->minimisation_state = SKIP_MINIMISE_STATE; 2251 iq->chase_to_rd = 0; 2252 iq->dnssec_lame_query = 0; 2253 verbose(VERB_ALGO, "query response was timeout"); 2254 return next_state(iq, QUERYTARGETS_STATE); 2255 } 2256 type = response_type_from_server( 2257 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 2258 iq->response, &iq->qchase, iq->dp); 2259 iq->chase_to_rd = 0; 2260 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) { 2261 /* When forwarding (RD bit is set), we handle referrals 2262 * differently. No queries should be sent elsewhere */ 2263 type = RESPONSE_TYPE_ANSWER; 2264 } 2265 if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected 2266 && !iq->dnssec_lame_query && 2267 !(iq->chase_flags&BIT_RD) 2268 && iq->sent_count < DNSSEC_LAME_DETECT_COUNT 2269 && type != RESPONSE_TYPE_LAME 2270 && type != RESPONSE_TYPE_REC_LAME 2271 && type != RESPONSE_TYPE_THROWAWAY 2272 && type != RESPONSE_TYPE_UNTYPED) { 2273 /* a possible answer, see if it is missing DNSSEC */ 2274 /* but not when forwarding, so we dont mark fwder lame */ 2275 if(!iter_msg_has_dnssec(iq->response)) { 2276 /* Mark this address as dnsseclame in this dp, 2277 * because that will make serverselection disprefer 2278 * it, but also, once it is the only final option, 2279 * use dnssec-lame-bypass if it needs to query there.*/ 2280 if(qstate->reply) { 2281 struct delegpt_addr* a = delegpt_find_addr( 2282 iq->dp, &qstate->reply->addr, 2283 qstate->reply->addrlen); 2284 if(a) a->dnsseclame = 1; 2285 } 2286 /* test the answer is from the zone we expected, 2287 * otherwise, (due to parent,child on same server), we 2288 * might mark the server,zone lame inappropriately */ 2289 if(!iter_msg_from_zone(iq->response, iq->dp, type, 2290 iq->qchase.qclass)) 2291 qstate->reply = NULL; 2292 type = RESPONSE_TYPE_LAME; 2293 dnsseclame = 1; 2294 } 2295 } else iq->dnssec_lame_query = 0; 2296 /* see if referral brings us close to the target */ 2297 if(type == RESPONSE_TYPE_REFERRAL) { 2298 struct ub_packed_rrset_key* ns = find_NS( 2299 iq->response->rep, iq->response->rep->an_numrrsets, 2300 iq->response->rep->an_numrrsets 2301 + iq->response->rep->ns_numrrsets); 2302 if(!ns) ns = find_NS(iq->response->rep, 0, 2303 iq->response->rep->an_numrrsets); 2304 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name) 2305 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){ 2306 verbose(VERB_ALGO, "bad referral, throwaway"); 2307 type = RESPONSE_TYPE_THROWAWAY; 2308 } else 2309 iter_scrub_ds(iq->response, ns, iq->dp->name); 2310 } else iter_scrub_ds(iq->response, NULL, NULL); 2311 if(type == RESPONSE_TYPE_THROWAWAY && 2312 FLAGS_GET_RCODE(iq->response->rep->flags) == LDNS_RCODE_YXDOMAIN) { 2313 /* YXDOMAIN is a permanent error, no need to retry */ 2314 type = RESPONSE_TYPE_ANSWER; 2315 } 2316 if(type == RESPONSE_TYPE_CNAME && iq->response->rep->an_numrrsets >= 1 2317 && ntohs(iq->response->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DNAME) { 2318 uint8_t* sname = NULL; 2319 size_t snamelen = 0; 2320 get_cname_target(iq->response->rep->rrsets[0], &sname, 2321 &snamelen); 2322 if(snamelen && dname_subdomain_c(sname, iq->response->rep->rrsets[0]->rk.dname)) { 2323 /* DNAME to a subdomain loop; do not recurse */ 2324 type = RESPONSE_TYPE_ANSWER; 2325 } 2326 } 2327 2328 /* handle each of the type cases */ 2329 if(type == RESPONSE_TYPE_ANSWER) { 2330 /* ANSWER type responses terminate the query algorithm, 2331 * so they sent on their */ 2332 if(verbosity >= VERB_DETAIL) { 2333 verbose(VERB_DETAIL, "query response was %s", 2334 FLAGS_GET_RCODE(iq->response->rep->flags) 2335 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER": 2336 (iq->response->rep->an_numrrsets?"ANSWER": 2337 "nodata ANSWER")); 2338 } 2339 /* if qtype is DS, check we have the right level of answer, 2340 * like grandchild answer but we need the middle, reject it */ 2341 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 2342 && !(iq->chase_flags&BIT_RD) 2343 && iter_ds_toolow(iq->response, iq->dp) 2344 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 2345 /* close down outstanding requests to be discarded */ 2346 outbound_list_clear(&iq->outlist); 2347 iq->num_current_queries = 0; 2348 fptr_ok(fptr_whitelist_modenv_detach_subs( 2349 qstate->env->detach_subs)); 2350 (*qstate->env->detach_subs)(qstate); 2351 iq->num_target_queries = 0; 2352 return processDSNSFind(qstate, iq, id); 2353 } 2354 if(!qstate->no_cache_store) 2355 iter_dns_store(qstate->env, &iq->response->qinfo, 2356 iq->response->rep, 0, qstate->prefetch_leeway, 2357 iq->dp&&iq->dp->has_parent_side_NS, 2358 qstate->region, qstate->query_flags); 2359 /* close down outstanding requests to be discarded */ 2360 outbound_list_clear(&iq->outlist); 2361 iq->num_current_queries = 0; 2362 fptr_ok(fptr_whitelist_modenv_detach_subs( 2363 qstate->env->detach_subs)); 2364 (*qstate->env->detach_subs)(qstate); 2365 iq->num_target_queries = 0; 2366 if(qstate->reply) 2367 sock_list_insert(&qstate->reply_origin, 2368 &qstate->reply->addr, qstate->reply->addrlen, 2369 qstate->region); 2370 if(iq->minimisation_state != DONOT_MINIMISE_STATE) { 2371 if(FLAGS_GET_RCODE(iq->response->rep->flags) != 2372 LDNS_RCODE_NOERROR) { 2373 if(qstate->env->cfg->qname_minimisation_strict) 2374 return final_state(iq); 2375 /* Best effort qname-minimisation. 2376 * Stop minimising and send full query when 2377 * RCODE is not NOERROR. */ 2378 iq->minimisation_state = DONOT_MINIMISE_STATE; 2379 } 2380 if(FLAGS_GET_RCODE(iq->response->rep->flags) == 2381 LDNS_RCODE_NXDOMAIN) { 2382 /* Stop resolving when NXDOMAIN is DNSSEC 2383 * signed. Based on assumption that namservers 2384 * serving signed zones do not return NXDOMAIN 2385 * for empty-non-terminals. */ 2386 if(iq->dnssec_expected) 2387 return final_state(iq); 2388 /* Make subrequest to validate intermediate 2389 * NXDOMAIN if harden-below-nxdomain is 2390 * enabled. */ 2391 if(qstate->env->cfg->harden_below_nxdomain) { 2392 struct module_qstate* subq = NULL; 2393 log_query_info(VERB_QUERY, 2394 "schedule NXDOMAIN validation:", 2395 &iq->response->qinfo); 2396 if(!generate_sub_request( 2397 iq->response->qinfo.qname, 2398 iq->response->qinfo.qname_len, 2399 iq->response->qinfo.qtype, 2400 iq->response->qinfo.qclass, 2401 qstate, id, iq, 2402 INIT_REQUEST_STATE, 2403 FINISHED_STATE, &subq, 1)) 2404 verbose(VERB_ALGO, 2405 "could not validate NXDOMAIN " 2406 "response"); 2407 } 2408 } 2409 return next_state(iq, QUERYTARGETS_STATE); 2410 } 2411 return final_state(iq); 2412 } else if(type == RESPONSE_TYPE_REFERRAL) { 2413 /* REFERRAL type responses get a reset of the 2414 * delegation point, and back to the QUERYTARGETS_STATE. */ 2415 verbose(VERB_DETAIL, "query response was REFERRAL"); 2416 2417 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) { 2418 /* we have a referral, no ratelimit, we can send 2419 * our queries to the given name */ 2420 infra_ratelimit_dec(qstate->env->infra_cache, 2421 iq->dp->name, iq->dp->namelen, 2422 *qstate->env->now); 2423 } 2424 2425 /* if hardened, only store referral if we asked for it */ 2426 if(!qstate->no_cache_store && 2427 (!qstate->env->cfg->harden_referral_path || 2428 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS 2429 && (qstate->query_flags&BIT_RD) 2430 && !(qstate->query_flags&BIT_CD) 2431 /* we know that all other NS rrsets are scrubbed 2432 * away, thus on referral only one is left. 2433 * see if that equals the query name... */ 2434 && ( /* auth section, but sometimes in answer section*/ 2435 reply_find_rrset_section_ns(iq->response->rep, 2436 iq->qchase.qname, iq->qchase.qname_len, 2437 LDNS_RR_TYPE_NS, iq->qchase.qclass) 2438 || reply_find_rrset_section_an(iq->response->rep, 2439 iq->qchase.qname, iq->qchase.qname_len, 2440 LDNS_RR_TYPE_NS, iq->qchase.qclass) 2441 ) 2442 ))) { 2443 /* Store the referral under the current query */ 2444 /* no prefetch-leeway, since its not the answer */ 2445 iter_dns_store(qstate->env, &iq->response->qinfo, 2446 iq->response->rep, 1, 0, 0, NULL, 0); 2447 if(iq->store_parent_NS) 2448 iter_store_parentside_NS(qstate->env, 2449 iq->response->rep); 2450 if(qstate->env->neg_cache) 2451 val_neg_addreferral(qstate->env->neg_cache, 2452 iq->response->rep, iq->dp->name); 2453 } 2454 /* store parent-side-in-zone-glue, if directly queried for */ 2455 if(!qstate->no_cache_store && iq->query_for_pside_glue 2456 && !iq->pside_glue) { 2457 iq->pside_glue = reply_find_rrset(iq->response->rep, 2458 iq->qchase.qname, iq->qchase.qname_len, 2459 iq->qchase.qtype, iq->qchase.qclass); 2460 if(iq->pside_glue) { 2461 log_rrset_key(VERB_ALGO, "found parent-side " 2462 "glue", iq->pside_glue); 2463 iter_store_parentside_rrset(qstate->env, 2464 iq->pside_glue); 2465 } 2466 } 2467 2468 /* Reset the event state, setting the current delegation 2469 * point to the referral. */ 2470 iq->deleg_msg = iq->response; 2471 iq->dp = delegpt_from_message(iq->response, qstate->region); 2472 if (qstate->env->cfg->qname_minimisation) 2473 iq->minimisation_state = INIT_MINIMISE_STATE; 2474 if(!iq->dp) 2475 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2476 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 2477 qstate->region, iq->dp)) 2478 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2479 if(iq->store_parent_NS && query_dname_compare(iq->dp->name, 2480 iq->store_parent_NS->name) == 0) 2481 iter_merge_retry_counts(iq->dp, iq->store_parent_NS); 2482 delegpt_log(VERB_ALGO, iq->dp); 2483 /* Count this as a referral. */ 2484 iq->referral_count++; 2485 iq->sent_count = 0; 2486 /* see if the next dp is a trust anchor, or a DS was sent 2487 * along, indicating dnssec is expected for next zone */ 2488 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, 2489 iq->dp, iq->response, iq->qchase.qclass); 2490 /* if dnssec, validating then also fetch the key for the DS */ 2491 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 2492 !(qstate->query_flags&BIT_CD)) 2493 generate_dnskey_prefetch(qstate, iq, id); 2494 2495 /* spawn off NS and addr to auth servers for the NS we just 2496 * got in the referral. This gets authoritative answer 2497 * (answer section trust level) rrset. 2498 * right after, we detach the subs, answer goes to cache. */ 2499 if(qstate->env->cfg->harden_referral_path) 2500 generate_ns_check(qstate, iq, id); 2501 2502 /* stop current outstanding queries. 2503 * FIXME: should the outstanding queries be waited for and 2504 * handled? Say by a subquery that inherits the outbound_entry. 2505 */ 2506 outbound_list_clear(&iq->outlist); 2507 iq->num_current_queries = 0; 2508 fptr_ok(fptr_whitelist_modenv_detach_subs( 2509 qstate->env->detach_subs)); 2510 (*qstate->env->detach_subs)(qstate); 2511 iq->num_target_queries = 0; 2512 verbose(VERB_ALGO, "cleared outbound list for next round"); 2513 return next_state(iq, QUERYTARGETS_STATE); 2514 } else if(type == RESPONSE_TYPE_CNAME) { 2515 uint8_t* sname = NULL; 2516 size_t snamelen = 0; 2517 /* CNAME type responses get a query restart (i.e., get a 2518 * reset of the query state and go back to INIT_REQUEST_STATE). 2519 */ 2520 verbose(VERB_DETAIL, "query response was CNAME"); 2521 if(verbosity >= VERB_ALGO) 2522 log_dns_msg("cname msg", &iq->response->qinfo, 2523 iq->response->rep); 2524 /* if qtype is DS, check we have the right level of answer, 2525 * like grandchild answer but we need the middle, reject it */ 2526 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 2527 && !(iq->chase_flags&BIT_RD) 2528 && iter_ds_toolow(iq->response, iq->dp) 2529 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 2530 outbound_list_clear(&iq->outlist); 2531 iq->num_current_queries = 0; 2532 fptr_ok(fptr_whitelist_modenv_detach_subs( 2533 qstate->env->detach_subs)); 2534 (*qstate->env->detach_subs)(qstate); 2535 iq->num_target_queries = 0; 2536 return processDSNSFind(qstate, iq, id); 2537 } 2538 /* Process the CNAME response. */ 2539 if(!handle_cname_response(qstate, iq, iq->response, 2540 &sname, &snamelen)) 2541 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2542 /* cache the CNAME response under the current query */ 2543 /* NOTE : set referral=1, so that rrsets get stored but not 2544 * the partial query answer (CNAME only). */ 2545 /* prefetchleeway applied because this updates answer parts */ 2546 if(!qstate->no_cache_store) 2547 iter_dns_store(qstate->env, &iq->response->qinfo, 2548 iq->response->rep, 1, qstate->prefetch_leeway, 2549 iq->dp&&iq->dp->has_parent_side_NS, NULL, 2550 qstate->query_flags); 2551 /* set the current request's qname to the new value. */ 2552 iq->qchase.qname = sname; 2553 iq->qchase.qname_len = snamelen; 2554 if (qstate->env->cfg->qname_minimisation) 2555 iq->minimisation_state = INIT_MINIMISE_STATE; 2556 /* Clear the query state, since this is a query restart. */ 2557 iq->deleg_msg = NULL; 2558 iq->dp = NULL; 2559 iq->dsns_point = NULL; 2560 /* Note the query restart. */ 2561 iq->query_restart_count++; 2562 iq->sent_count = 0; 2563 2564 /* stop current outstanding queries. 2565 * FIXME: should the outstanding queries be waited for and 2566 * handled? Say by a subquery that inherits the outbound_entry. 2567 */ 2568 outbound_list_clear(&iq->outlist); 2569 iq->num_current_queries = 0; 2570 fptr_ok(fptr_whitelist_modenv_detach_subs( 2571 qstate->env->detach_subs)); 2572 (*qstate->env->detach_subs)(qstate); 2573 iq->num_target_queries = 0; 2574 if(qstate->reply) 2575 sock_list_insert(&qstate->reply_origin, 2576 &qstate->reply->addr, qstate->reply->addrlen, 2577 qstate->region); 2578 verbose(VERB_ALGO, "cleared outbound list for query restart"); 2579 /* go to INIT_REQUEST_STATE for new qname. */ 2580 return next_state(iq, INIT_REQUEST_STATE); 2581 } else if(type == RESPONSE_TYPE_LAME) { 2582 /* Cache the LAMEness. */ 2583 verbose(VERB_DETAIL, "query response was %sLAME", 2584 dnsseclame?"DNSSEC ":""); 2585 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2586 log_err("mark lame: mismatch in qname and dpname"); 2587 /* throwaway this reply below */ 2588 } else if(qstate->reply) { 2589 /* need addr for lameness cache, but we may have 2590 * gotten this from cache, so test to be sure */ 2591 if(!infra_set_lame(qstate->env->infra_cache, 2592 &qstate->reply->addr, qstate->reply->addrlen, 2593 iq->dp->name, iq->dp->namelen, 2594 *qstate->env->now, dnsseclame, 0, 2595 iq->qchase.qtype)) 2596 log_err("mark host lame: out of memory"); 2597 } 2598 } else if(type == RESPONSE_TYPE_REC_LAME) { 2599 /* Cache the LAMEness. */ 2600 verbose(VERB_DETAIL, "query response REC_LAME: " 2601 "recursive but not authoritative server"); 2602 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2603 log_err("mark rec_lame: mismatch in qname and dpname"); 2604 /* throwaway this reply below */ 2605 } else if(qstate->reply) { 2606 /* need addr for lameness cache, but we may have 2607 * gotten this from cache, so test to be sure */ 2608 verbose(VERB_DETAIL, "mark as REC_LAME"); 2609 if(!infra_set_lame(qstate->env->infra_cache, 2610 &qstate->reply->addr, qstate->reply->addrlen, 2611 iq->dp->name, iq->dp->namelen, 2612 *qstate->env->now, 0, 1, iq->qchase.qtype)) 2613 log_err("mark host lame: out of memory"); 2614 } 2615 } else if(type == RESPONSE_TYPE_THROWAWAY) { 2616 /* LAME and THROWAWAY responses are handled the same way. 2617 * In this case, the event is just sent directly back to 2618 * the QUERYTARGETS_STATE without resetting anything, 2619 * because, clearly, the next target must be tried. */ 2620 verbose(VERB_DETAIL, "query response was THROWAWAY"); 2621 } else { 2622 log_warn("A query response came back with an unknown type: %d", 2623 (int)type); 2624 } 2625 2626 /* LAME, THROWAWAY and "unknown" all end up here. 2627 * Recycle to the QUERYTARGETS state to hopefully try a 2628 * different target. */ 2629 if (qstate->env->cfg->qname_minimisation && 2630 !qstate->env->cfg->qname_minimisation_strict) 2631 iq->minimisation_state = DONOT_MINIMISE_STATE; 2632 return next_state(iq, QUERYTARGETS_STATE); 2633 } 2634 2635 /** 2636 * Return priming query results to interested super querystates. 2637 * 2638 * Sets the delegation point and delegation message (not nonRD queries). 2639 * This is a callback from walk_supers. 2640 * 2641 * @param qstate: priming query state that finished. 2642 * @param id: module id. 2643 * @param forq: the qstate for which priming has been done. 2644 */ 2645 static void 2646 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq) 2647 { 2648 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2649 struct delegpt* dp = NULL; 2650 2651 log_assert(qstate->is_priming || foriq->wait_priming_stub); 2652 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2653 /* Convert our response to a delegation point */ 2654 dp = delegpt_from_message(qstate->return_msg, forq->region); 2655 if(!dp) { 2656 /* if there is no convertable delegation point, then 2657 * the ANSWER type was (presumably) a negative answer. */ 2658 verbose(VERB_ALGO, "prime response was not a positive " 2659 "ANSWER; failing"); 2660 foriq->dp = NULL; 2661 foriq->state = QUERYTARGETS_STATE; 2662 return; 2663 } 2664 2665 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo); 2666 delegpt_log(VERB_ALGO, dp); 2667 foriq->dp = dp; 2668 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region); 2669 if(!foriq->deleg_msg) { 2670 log_err("copy prime response: out of memory"); 2671 foriq->dp = NULL; 2672 foriq->state = QUERYTARGETS_STATE; 2673 return; 2674 } 2675 2676 /* root priming responses go to init stage 2, priming stub 2677 * responses to to stage 3. */ 2678 if(foriq->wait_priming_stub) { 2679 foriq->state = INIT_REQUEST_3_STATE; 2680 foriq->wait_priming_stub = 0; 2681 } else foriq->state = INIT_REQUEST_2_STATE; 2682 /* because we are finished, the parent will be reactivated */ 2683 } 2684 2685 /** 2686 * This handles the response to a priming query. This is used to handle both 2687 * root and stub priming responses. This is basically the equivalent of the 2688 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat 2689 * REFERRALs as ANSWERS. It will also update and reactivate the originating 2690 * event. 2691 * 2692 * @param qstate: query state. 2693 * @param id: module id. 2694 * @return true if the event needs more immediate processing, false if not. 2695 * This state always returns false. 2696 */ 2697 static int 2698 processPrimeResponse(struct module_qstate* qstate, int id) 2699 { 2700 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2701 enum response_type type; 2702 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */ 2703 type = response_type_from_server( 2704 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 2705 iq->response, &iq->qchase, iq->dp); 2706 if(type == RESPONSE_TYPE_ANSWER) { 2707 qstate->return_rcode = LDNS_RCODE_NOERROR; 2708 qstate->return_msg = iq->response; 2709 } else { 2710 qstate->return_rcode = LDNS_RCODE_SERVFAIL; 2711 qstate->return_msg = NULL; 2712 } 2713 2714 /* validate the root or stub after priming (if enabled). 2715 * This is the same query as the prime query, but with validation. 2716 * Now that we are primed, the additional queries that validation 2717 * may need can be resolved, such as DLV. */ 2718 if(qstate->env->cfg->harden_referral_path) { 2719 struct module_qstate* subq = NULL; 2720 log_nametypeclass(VERB_ALGO, "schedule prime validation", 2721 qstate->qinfo.qname, qstate->qinfo.qtype, 2722 qstate->qinfo.qclass); 2723 if(!generate_sub_request(qstate->qinfo.qname, 2724 qstate->qinfo.qname_len, qstate->qinfo.qtype, 2725 qstate->qinfo.qclass, qstate, id, iq, 2726 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 2727 verbose(VERB_ALGO, "could not generate prime check"); 2728 } 2729 generate_a_aaaa_check(qstate, iq, id); 2730 } 2731 2732 /* This event is finished. */ 2733 qstate->ext_state[id] = module_finished; 2734 return 0; 2735 } 2736 2737 /** 2738 * Do final processing on responses to target queries. Events reach this 2739 * state after the iterative resolution algorithm terminates. This state is 2740 * responsible for reactiving the original event, and housekeeping related 2741 * to received target responses (caching, updating the current delegation 2742 * point, etc). 2743 * Callback from walk_supers for every super state that is interested in 2744 * the results from this query. 2745 * 2746 * @param qstate: query state. 2747 * @param id: module id. 2748 * @param forq: super query state. 2749 */ 2750 static void 2751 processTargetResponse(struct module_qstate* qstate, int id, 2752 struct module_qstate* forq) 2753 { 2754 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2755 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2756 struct ub_packed_rrset_key* rrset; 2757 struct delegpt_ns* dpns; 2758 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2759 2760 foriq->state = QUERYTARGETS_STATE; 2761 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo); 2762 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo); 2763 2764 /* Tell the originating event that this target query has finished 2765 * (regardless if it succeeded or not). */ 2766 foriq->num_target_queries--; 2767 2768 /* check to see if parent event is still interested (in orig name). */ 2769 if(!foriq->dp) { 2770 verbose(VERB_ALGO, "subq: parent not interested, was reset"); 2771 return; /* not interested anymore */ 2772 } 2773 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname, 2774 qstate->qinfo.qname_len); 2775 if(!dpns) { 2776 /* If not interested, just stop processing this event */ 2777 verbose(VERB_ALGO, "subq: parent not interested anymore"); 2778 /* could be because parent was jostled out of the cache, 2779 and a new identical query arrived, that does not want it*/ 2780 return; 2781 } 2782 2783 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */ 2784 if(iq->pside_glue) { 2785 /* if the pside_glue is NULL, then it could not be found, 2786 * the done_pside is already set when created and a cache 2787 * entry created in processFinished so nothing to do here */ 2788 log_rrset_key(VERB_ALGO, "add parentside glue to dp", 2789 iq->pside_glue); 2790 if(!delegpt_add_rrset(foriq->dp, forq->region, 2791 iq->pside_glue, 1)) 2792 log_err("out of memory adding pside glue"); 2793 } 2794 2795 /* This response is relevant to the current query, so we 2796 * add (attempt to add, anyway) this target(s) and reactivate 2797 * the original event. 2798 * NOTE: we could only look for the AnswerRRset if the 2799 * response type was ANSWER. */ 2800 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep); 2801 if(rrset) { 2802 /* if CNAMEs have been followed - add new NS to delegpt. */ 2803 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */ 2804 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname, 2805 rrset->rk.dname_len)) { 2806 /* if dpns->lame then set newcname ns lame too */ 2807 if(!delegpt_add_ns(foriq->dp, forq->region, 2808 rrset->rk.dname, dpns->lame)) 2809 log_err("out of memory adding cnamed-ns"); 2810 } 2811 /* if dpns->lame then set the address(es) lame too */ 2812 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset, 2813 dpns->lame)) 2814 log_err("out of memory adding targets"); 2815 verbose(VERB_ALGO, "added target response"); 2816 delegpt_log(VERB_ALGO, foriq->dp); 2817 } else { 2818 verbose(VERB_ALGO, "iterator TargetResponse failed"); 2819 dpns->resolved = 1; /* fail the target */ 2820 } 2821 } 2822 2823 /** 2824 * Process response for DS NS Find queries, that attempt to find the delegation 2825 * point where we ask the DS query from. 2826 * 2827 * @param qstate: query state. 2828 * @param id: module id. 2829 * @param forq: super query state. 2830 */ 2831 static void 2832 processDSNSResponse(struct module_qstate* qstate, int id, 2833 struct module_qstate* forq) 2834 { 2835 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2836 2837 /* if the finished (iq->response) query has no NS set: continue 2838 * up to look for the right dp; nothing to change, do DPNSstate */ 2839 if(qstate->return_rcode != LDNS_RCODE_NOERROR) 2840 return; /* seek further */ 2841 /* find the NS RRset (without allowing CNAMEs) */ 2842 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname, 2843 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS, 2844 qstate->qinfo.qclass)){ 2845 return; /* seek further */ 2846 } 2847 2848 /* else, store as DP and continue at querytargets */ 2849 foriq->state = QUERYTARGETS_STATE; 2850 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region); 2851 if(!foriq->dp) { 2852 log_err("out of memory in dsns dp alloc"); 2853 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */ 2854 } 2855 /* success, go query the querytargets in the new dp (and go down) */ 2856 } 2857 2858 /** 2859 * Process response for qclass=ANY queries for a particular class. 2860 * Append to result or error-exit. 2861 * 2862 * @param qstate: query state. 2863 * @param id: module id. 2864 * @param forq: super query state. 2865 */ 2866 static void 2867 processClassResponse(struct module_qstate* qstate, int id, 2868 struct module_qstate* forq) 2869 { 2870 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2871 struct dns_msg* from = qstate->return_msg; 2872 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo); 2873 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo); 2874 if(qstate->return_rcode != LDNS_RCODE_NOERROR) { 2875 /* cause servfail for qclass ANY query */ 2876 foriq->response = NULL; 2877 foriq->state = FINISHED_STATE; 2878 return; 2879 } 2880 /* append result */ 2881 if(!foriq->response) { 2882 /* allocate the response: copy RCODE, sec_state */ 2883 foriq->response = dns_copy_msg(from, forq->region); 2884 if(!foriq->response) { 2885 log_err("malloc failed for qclass ANY response"); 2886 foriq->state = FINISHED_STATE; 2887 return; 2888 } 2889 foriq->response->qinfo.qclass = forq->qinfo.qclass; 2890 /* qclass ANY does not receive the AA flag on replies */ 2891 foriq->response->rep->authoritative = 0; 2892 } else { 2893 struct dns_msg* to = foriq->response; 2894 /* add _from_ this response _to_ existing collection */ 2895 /* if there are records, copy RCODE */ 2896 /* lower sec_state if this message is lower */ 2897 if(from->rep->rrset_count != 0) { 2898 size_t n = from->rep->rrset_count+to->rep->rrset_count; 2899 struct ub_packed_rrset_key** dest, **d; 2900 /* copy appropriate rcode */ 2901 to->rep->flags = from->rep->flags; 2902 /* copy rrsets */ 2903 if(from->rep->rrset_count > RR_COUNT_MAX || 2904 to->rep->rrset_count > RR_COUNT_MAX) { 2905 log_err("malloc failed (too many rrsets) in collect ANY"); 2906 foriq->state = FINISHED_STATE; 2907 return; /* integer overflow protection */ 2908 } 2909 dest = regional_alloc(forq->region, sizeof(dest[0])*n); 2910 if(!dest) { 2911 log_err("malloc failed in collect ANY"); 2912 foriq->state = FINISHED_STATE; 2913 return; 2914 } 2915 d = dest; 2916 /* copy AN */ 2917 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets 2918 * sizeof(dest[0])); 2919 dest += to->rep->an_numrrsets; 2920 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets 2921 * sizeof(dest[0])); 2922 dest += from->rep->an_numrrsets; 2923 /* copy NS */ 2924 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets, 2925 to->rep->ns_numrrsets * sizeof(dest[0])); 2926 dest += to->rep->ns_numrrsets; 2927 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets, 2928 from->rep->ns_numrrsets * sizeof(dest[0])); 2929 dest += from->rep->ns_numrrsets; 2930 /* copy AR */ 2931 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+ 2932 to->rep->ns_numrrsets, 2933 to->rep->ar_numrrsets * sizeof(dest[0])); 2934 dest += to->rep->ar_numrrsets; 2935 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+ 2936 from->rep->ns_numrrsets, 2937 from->rep->ar_numrrsets * sizeof(dest[0])); 2938 /* update counts */ 2939 to->rep->rrsets = d; 2940 to->rep->an_numrrsets += from->rep->an_numrrsets; 2941 to->rep->ns_numrrsets += from->rep->ns_numrrsets; 2942 to->rep->ar_numrrsets += from->rep->ar_numrrsets; 2943 to->rep->rrset_count = n; 2944 } 2945 if(from->rep->security < to->rep->security) /* lowest sec */ 2946 to->rep->security = from->rep->security; 2947 if(from->rep->qdcount != 0) /* insert qd if appropriate */ 2948 to->rep->qdcount = from->rep->qdcount; 2949 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */ 2950 to->rep->ttl = from->rep->ttl; 2951 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl) 2952 to->rep->prefetch_ttl = from->rep->prefetch_ttl; 2953 } 2954 /* are we done? */ 2955 foriq->num_current_queries --; 2956 if(foriq->num_current_queries == 0) 2957 foriq->state = FINISHED_STATE; 2958 } 2959 2960 /** 2961 * Collect class ANY responses and make them into one response. This 2962 * state is started and it creates queries for all classes (that have 2963 * root hints). The answers are then collected. 2964 * 2965 * @param qstate: query state. 2966 * @param id: module id. 2967 * @return true if the event needs more immediate processing, false if not. 2968 */ 2969 static int 2970 processCollectClass(struct module_qstate* qstate, int id) 2971 { 2972 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2973 struct module_qstate* subq; 2974 /* If qchase.qclass == 0 then send out queries for all classes. 2975 * Otherwise, do nothing (wait for all answers to arrive and the 2976 * processClassResponse to put them together, and that moves us 2977 * towards the Finished state when done. */ 2978 if(iq->qchase.qclass == 0) { 2979 uint16_t c = 0; 2980 iq->qchase.qclass = LDNS_RR_CLASS_ANY; 2981 while(iter_get_next_root(qstate->env->hints, 2982 qstate->env->fwds, &c)) { 2983 /* generate query for this class */ 2984 log_nametypeclass(VERB_ALGO, "spawn collect query", 2985 qstate->qinfo.qname, qstate->qinfo.qtype, c); 2986 if(!generate_sub_request(qstate->qinfo.qname, 2987 qstate->qinfo.qname_len, qstate->qinfo.qtype, 2988 c, qstate, id, iq, INIT_REQUEST_STATE, 2989 FINISHED_STATE, &subq, 2990 (int)!(qstate->query_flags&BIT_CD))) { 2991 return error_response(qstate, id, 2992 LDNS_RCODE_SERVFAIL); 2993 } 2994 /* ignore subq, no special init required */ 2995 iq->num_current_queries ++; 2996 if(c == 0xffff) 2997 break; 2998 else c++; 2999 } 3000 /* if no roots are configured at all, return */ 3001 if(iq->num_current_queries == 0) { 3002 verbose(VERB_ALGO, "No root hints or fwds, giving up " 3003 "on qclass ANY"); 3004 return error_response(qstate, id, LDNS_RCODE_REFUSED); 3005 } 3006 /* return false, wait for queries to return */ 3007 } 3008 /* if woke up here because of an answer, wait for more answers */ 3009 return 0; 3010 } 3011 3012 /** 3013 * This handles the final state for first-tier responses (i.e., responses to 3014 * externally generated queries). 3015 * 3016 * @param qstate: query state. 3017 * @param iq: iterator query state. 3018 * @param id: module id. 3019 * @return true if the event needs more processing, false if not. Since this 3020 * is the final state for an event, it always returns false. 3021 */ 3022 static int 3023 processFinished(struct module_qstate* qstate, struct iter_qstate* iq, 3024 int id) 3025 { 3026 log_query_info(VERB_QUERY, "finishing processing for", 3027 &qstate->qinfo); 3028 3029 /* store negative cache element for parent side glue. */ 3030 if(!qstate->no_cache_store && iq->query_for_pside_glue 3031 && !iq->pside_glue) 3032 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 3033 iq->deleg_msg?iq->deleg_msg->rep: 3034 (iq->response?iq->response->rep:NULL)); 3035 if(!iq->response) { 3036 verbose(VERB_ALGO, "No response is set, servfail"); 3037 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3038 } 3039 3040 /* Make sure that the RA flag is set (since the presence of 3041 * this module means that recursion is available) */ 3042 iq->response->rep->flags |= BIT_RA; 3043 3044 /* Clear the AA flag */ 3045 /* FIXME: does this action go here or in some other module? */ 3046 iq->response->rep->flags &= ~BIT_AA; 3047 3048 /* make sure QR flag is on */ 3049 iq->response->rep->flags |= BIT_QR; 3050 3051 /* we have finished processing this query */ 3052 qstate->ext_state[id] = module_finished; 3053 3054 /* TODO: we are using a private TTL, trim the response. */ 3055 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */ 3056 3057 /* prepend any items we have accumulated */ 3058 if(iq->an_prepend_list || iq->ns_prepend_list) { 3059 if(!iter_prepend(iq, iq->response, qstate->region)) { 3060 log_err("prepend rrsets: out of memory"); 3061 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3062 } 3063 /* reset the query name back */ 3064 iq->response->qinfo = qstate->qinfo; 3065 /* the security state depends on the combination */ 3066 iq->response->rep->security = sec_status_unchecked; 3067 /* store message with the finished prepended items, 3068 * but only if we did recursion. The nonrecursion referral 3069 * from cache does not need to be stored in the msg cache. */ 3070 if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) { 3071 iter_dns_store(qstate->env, &qstate->qinfo, 3072 iq->response->rep, 0, qstate->prefetch_leeway, 3073 iq->dp&&iq->dp->has_parent_side_NS, 3074 qstate->region, qstate->query_flags); 3075 } 3076 } 3077 qstate->return_rcode = LDNS_RCODE_NOERROR; 3078 qstate->return_msg = iq->response; 3079 return 0; 3080 } 3081 3082 /* 3083 * Return priming query results to interestes super querystates. 3084 * 3085 * Sets the delegation point and delegation message (not nonRD queries). 3086 * This is a callback from walk_supers. 3087 * 3088 * @param qstate: query state that finished. 3089 * @param id: module id. 3090 * @param super: the qstate to inform. 3091 */ 3092 void 3093 iter_inform_super(struct module_qstate* qstate, int id, 3094 struct module_qstate* super) 3095 { 3096 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY) 3097 processClassResponse(qstate, id, super); 3098 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) 3099 super->minfo[id])->state == DSNS_FIND_STATE) 3100 processDSNSResponse(qstate, id, super); 3101 else if(qstate->return_rcode != LDNS_RCODE_NOERROR) 3102 error_supers(qstate, id, super); 3103 else if(qstate->is_priming) 3104 prime_supers(qstate, id, super); 3105 else processTargetResponse(qstate, id, super); 3106 } 3107 3108 /** 3109 * Handle iterator state. 3110 * Handle events. This is the real processing loop for events, responsible 3111 * for moving events through the various states. If a processing method 3112 * returns true, then it will be advanced to the next state. If false, then 3113 * processing will stop. 3114 * 3115 * @param qstate: query state. 3116 * @param ie: iterator shared global environment. 3117 * @param iq: iterator query state. 3118 * @param id: module id. 3119 */ 3120 static void 3121 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq, 3122 struct iter_env* ie, int id) 3123 { 3124 int cont = 1; 3125 while(cont) { 3126 verbose(VERB_ALGO, "iter_handle processing q with state %s", 3127 iter_state_to_string(iq->state)); 3128 switch(iq->state) { 3129 case INIT_REQUEST_STATE: 3130 cont = processInitRequest(qstate, iq, ie, id); 3131 break; 3132 case INIT_REQUEST_2_STATE: 3133 cont = processInitRequest2(qstate, iq, id); 3134 break; 3135 case INIT_REQUEST_3_STATE: 3136 cont = processInitRequest3(qstate, iq, id); 3137 break; 3138 case QUERYTARGETS_STATE: 3139 cont = processQueryTargets(qstate, iq, ie, id); 3140 break; 3141 case QUERY_RESP_STATE: 3142 cont = processQueryResponse(qstate, iq, id); 3143 break; 3144 case PRIME_RESP_STATE: 3145 cont = processPrimeResponse(qstate, id); 3146 break; 3147 case COLLECT_CLASS_STATE: 3148 cont = processCollectClass(qstate, id); 3149 break; 3150 case DSNS_FIND_STATE: 3151 cont = processDSNSFind(qstate, iq, id); 3152 break; 3153 case FINISHED_STATE: 3154 cont = processFinished(qstate, iq, id); 3155 break; 3156 default: 3157 log_warn("iterator: invalid state: %d", 3158 iq->state); 3159 cont = 0; 3160 break; 3161 } 3162 } 3163 } 3164 3165 /** 3166 * This is the primary entry point for processing request events. Note that 3167 * this method should only be used by external modules. 3168 * @param qstate: query state. 3169 * @param ie: iterator shared global environment. 3170 * @param iq: iterator query state. 3171 * @param id: module id. 3172 */ 3173 static void 3174 process_request(struct module_qstate* qstate, struct iter_qstate* iq, 3175 struct iter_env* ie, int id) 3176 { 3177 /* external requests start in the INIT state, and finish using the 3178 * FINISHED state. */ 3179 iq->state = INIT_REQUEST_STATE; 3180 iq->final_state = FINISHED_STATE; 3181 verbose(VERB_ALGO, "process_request: new external request event"); 3182 iter_handle(qstate, iq, ie, id); 3183 } 3184 3185 /** process authoritative server reply */ 3186 static void 3187 process_response(struct module_qstate* qstate, struct iter_qstate* iq, 3188 struct iter_env* ie, int id, struct outbound_entry* outbound, 3189 enum module_ev event) 3190 { 3191 struct msg_parse* prs; 3192 struct edns_data edns; 3193 sldns_buffer* pkt; 3194 3195 verbose(VERB_ALGO, "process_response: new external response event"); 3196 iq->response = NULL; 3197 iq->state = QUERY_RESP_STATE; 3198 if(event == module_event_noreply || event == module_event_error) { 3199 if(event == module_event_noreply && iq->sent_count >= 3 && 3200 qstate->env->cfg->use_caps_bits_for_id && 3201 !iq->caps_fallback) { 3202 /* start fallback */ 3203 iq->caps_fallback = 1; 3204 iq->caps_server = 0; 3205 iq->caps_reply = NULL; 3206 iq->caps_response = NULL; 3207 iq->state = QUERYTARGETS_STATE; 3208 iq->num_current_queries--; 3209 /* need fresh attempts for the 0x20 fallback, if 3210 * that was the cause for the failure */ 3211 iter_dec_attempts(iq->dp, 3); 3212 verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback"); 3213 goto handle_it; 3214 } 3215 goto handle_it; 3216 } 3217 if( (event != module_event_reply && event != module_event_capsfail) 3218 || !qstate->reply) { 3219 log_err("Bad event combined with response"); 3220 outbound_list_remove(&iq->outlist, outbound); 3221 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3222 return; 3223 } 3224 3225 /* parse message */ 3226 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch, 3227 sizeof(struct msg_parse)); 3228 if(!prs) { 3229 log_err("out of memory on incoming message"); 3230 /* like packet got dropped */ 3231 goto handle_it; 3232 } 3233 memset(prs, 0, sizeof(*prs)); 3234 memset(&edns, 0, sizeof(edns)); 3235 pkt = qstate->reply->c->buffer; 3236 sldns_buffer_set_position(pkt, 0); 3237 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) { 3238 verbose(VERB_ALGO, "parse error on reply packet"); 3239 goto handle_it; 3240 } 3241 /* edns is not examined, but removed from message to help cache */ 3242 if(parse_extract_edns(prs, &edns, qstate->env->scratch) != 3243 LDNS_RCODE_NOERROR) 3244 goto handle_it; 3245 3246 /* Copy the edns options we may got from the back end */ 3247 if(edns.opt_list) { 3248 qstate->edns_opts_back_in = edns_opt_copy_region(edns.opt_list, 3249 qstate->region); 3250 if(!qstate->edns_opts_back_in) { 3251 log_err("out of memory on incoming message"); 3252 /* like packet got dropped */ 3253 goto handle_it; 3254 } 3255 if(!inplace_cb_edns_back_parsed_call(qstate->env, qstate)) { 3256 log_err("unable to call edns_back_parsed callback"); 3257 goto handle_it; 3258 } 3259 } 3260 3261 /* remove CD-bit, we asked for in case we handle validation ourself */ 3262 prs->flags &= ~BIT_CD; 3263 3264 /* normalize and sanitize: easy to delete items from linked lists */ 3265 if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name, 3266 qstate->env->scratch, qstate->env, ie)) { 3267 /* if 0x20 enabled, start fallback, but we have no message */ 3268 if(event == module_event_capsfail && !iq->caps_fallback) { 3269 iq->caps_fallback = 1; 3270 iq->caps_server = 0; 3271 iq->caps_reply = NULL; 3272 iq->caps_response = NULL; 3273 iq->state = QUERYTARGETS_STATE; 3274 iq->num_current_queries--; 3275 verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response"); 3276 } 3277 goto handle_it; 3278 } 3279 3280 /* allocate response dns_msg in region */ 3281 iq->response = dns_alloc_msg(pkt, prs, qstate->region); 3282 if(!iq->response) 3283 goto handle_it; 3284 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo); 3285 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name, 3286 &qstate->reply->addr, qstate->reply->addrlen); 3287 if(verbosity >= VERB_ALGO) 3288 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo, 3289 iq->response->rep); 3290 3291 if(event == module_event_capsfail || iq->caps_fallback) { 3292 /* for fallback we care about main answer, not additionals */ 3293 /* removing that makes comparison more likely to succeed */ 3294 caps_strip_reply(iq->response->rep); 3295 if(!iq->caps_fallback) { 3296 /* start fallback */ 3297 iq->caps_fallback = 1; 3298 iq->caps_server = 0; 3299 iq->caps_reply = iq->response->rep; 3300 iq->caps_response = iq->response; 3301 iq->state = QUERYTARGETS_STATE; 3302 iq->num_current_queries--; 3303 verbose(VERB_DETAIL, "Capsforid: starting fallback"); 3304 goto handle_it; 3305 } else { 3306 /* check if reply is the same, otherwise, fail */ 3307 if(!iq->caps_reply) { 3308 iq->caps_reply = iq->response->rep; 3309 iq->caps_response = iq->response; 3310 iq->caps_server = -1; /*become zero at ++, 3311 so that we start the full set of trials */ 3312 } else if(caps_failed_rcode(iq->caps_reply) && 3313 !caps_failed_rcode(iq->response->rep)) { 3314 /* prefer to upgrade to non-SERVFAIL */ 3315 iq->caps_reply = iq->response->rep; 3316 iq->caps_response = iq->response; 3317 } else if(!caps_failed_rcode(iq->caps_reply) && 3318 caps_failed_rcode(iq->response->rep)) { 3319 /* if we have non-SERVFAIL as answer then 3320 * we can ignore SERVFAILs for the equality 3321 * comparison */ 3322 /* no instructions here, skip other else */ 3323 } else if(caps_failed_rcode(iq->caps_reply) && 3324 caps_failed_rcode(iq->response->rep)) { 3325 /* failure is same as other failure in fallbk*/ 3326 /* no instructions here, skip other else */ 3327 } else if(!reply_equal(iq->response->rep, iq->caps_reply, 3328 qstate->env->scratch)) { 3329 verbose(VERB_DETAIL, "Capsforid fallback: " 3330 "getting different replies, failed"); 3331 outbound_list_remove(&iq->outlist, outbound); 3332 (void)error_response(qstate, id, 3333 LDNS_RCODE_SERVFAIL); 3334 return; 3335 } 3336 /* continue the fallback procedure at next server */ 3337 iq->caps_server++; 3338 iq->state = QUERYTARGETS_STATE; 3339 iq->num_current_queries--; 3340 verbose(VERB_DETAIL, "Capsforid: reply is equal. " 3341 "go to next fallback"); 3342 goto handle_it; 3343 } 3344 } 3345 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */ 3346 3347 handle_it: 3348 outbound_list_remove(&iq->outlist, outbound); 3349 iter_handle(qstate, iq, ie, id); 3350 } 3351 3352 void 3353 iter_operate(struct module_qstate* qstate, enum module_ev event, int id, 3354 struct outbound_entry* outbound) 3355 { 3356 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 3357 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 3358 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s", 3359 id, strextstate(qstate->ext_state[id]), strmodulevent(event)); 3360 if(iq) log_query_info(VERB_QUERY, "iterator operate: query", 3361 &qstate->qinfo); 3362 if(iq && qstate->qinfo.qname != iq->qchase.qname) 3363 log_query_info(VERB_QUERY, "iterator operate: chased to", 3364 &iq->qchase); 3365 3366 /* perform iterator state machine */ 3367 if((event == module_event_new || event == module_event_pass) && 3368 iq == NULL) { 3369 if(!iter_new(qstate, id)) { 3370 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3371 return; 3372 } 3373 iq = (struct iter_qstate*)qstate->minfo[id]; 3374 process_request(qstate, iq, ie, id); 3375 return; 3376 } 3377 if(iq && event == module_event_pass) { 3378 iter_handle(qstate, iq, ie, id); 3379 return; 3380 } 3381 if(iq && outbound) { 3382 process_response(qstate, iq, ie, id, outbound, event); 3383 return; 3384 } 3385 if(event == module_event_error) { 3386 verbose(VERB_ALGO, "got called with event error, giving up"); 3387 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3388 return; 3389 } 3390 3391 log_err("bad event for iterator"); 3392 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3393 } 3394 3395 void 3396 iter_clear(struct module_qstate* qstate, int id) 3397 { 3398 struct iter_qstate* iq; 3399 if(!qstate) 3400 return; 3401 iq = (struct iter_qstate*)qstate->minfo[id]; 3402 if(iq) { 3403 outbound_list_clear(&iq->outlist); 3404 if(iq->target_count && --iq->target_count[0] == 0) 3405 free(iq->target_count); 3406 iq->num_current_queries = 0; 3407 } 3408 qstate->minfo[id] = NULL; 3409 } 3410 3411 size_t 3412 iter_get_mem(struct module_env* env, int id) 3413 { 3414 struct iter_env* ie = (struct iter_env*)env->modinfo[id]; 3415 if(!ie) 3416 return 0; 3417 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1) 3418 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv); 3419 } 3420 3421 /** 3422 * The iterator function block 3423 */ 3424 static struct module_func_block iter_block = { 3425 "iterator", 3426 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super, 3427 &iter_clear, &iter_get_mem 3428 }; 3429 3430 struct module_func_block* 3431 iter_get_funcblock(void) 3432 { 3433 return &iter_block; 3434 } 3435 3436 const char* 3437 iter_state_to_string(enum iter_state state) 3438 { 3439 switch (state) 3440 { 3441 case INIT_REQUEST_STATE : 3442 return "INIT REQUEST STATE"; 3443 case INIT_REQUEST_2_STATE : 3444 return "INIT REQUEST STATE (stage 2)"; 3445 case INIT_REQUEST_3_STATE: 3446 return "INIT REQUEST STATE (stage 3)"; 3447 case QUERYTARGETS_STATE : 3448 return "QUERY TARGETS STATE"; 3449 case PRIME_RESP_STATE : 3450 return "PRIME RESPONSE STATE"; 3451 case COLLECT_CLASS_STATE : 3452 return "COLLECT CLASS STATE"; 3453 case DSNS_FIND_STATE : 3454 return "DSNS FIND STATE"; 3455 case QUERY_RESP_STATE : 3456 return "QUERY RESPONSE STATE"; 3457 case FINISHED_STATE : 3458 return "FINISHED RESPONSE STATE"; 3459 default : 3460 return "UNKNOWN ITER STATE"; 3461 } 3462 } 3463 3464 int 3465 iter_state_is_responsestate(enum iter_state s) 3466 { 3467 switch(s) { 3468 case INIT_REQUEST_STATE : 3469 case INIT_REQUEST_2_STATE : 3470 case INIT_REQUEST_3_STATE : 3471 case QUERYTARGETS_STATE : 3472 case COLLECT_CLASS_STATE : 3473 return 0; 3474 default: 3475 break; 3476 } 3477 return 1; 3478 } 3479