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 recursive 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/rrset.h" 56 #include "services/cache/infra.h" 57 #include "services/authzone.h" 58 #include "util/module.h" 59 #include "util/netevent.h" 60 #include "util/net_help.h" 61 #include "util/regional.h" 62 #include "util/data/dname.h" 63 #include "util/data/msgencode.h" 64 #include "util/fptr_wlist.h" 65 #include "util/config_file.h" 66 #include "util/random.h" 67 #include "sldns/rrdef.h" 68 #include "sldns/wire2str.h" 69 #include "sldns/str2wire.h" 70 #include "sldns/parseutil.h" 71 #include "sldns/sbuffer.h" 72 73 /* number of packets */ 74 int MAX_GLOBAL_QUOTA = 128; 75 /* in msec */ 76 int UNKNOWN_SERVER_NICENESS = 376; 77 /* in msec */ 78 int USEFUL_SERVER_TOP_TIMEOUT = 120000; 79 /* Equals USEFUL_SERVER_TOP_TIMEOUT*4 */ 80 int BLACKLIST_PENALTY = (120000*4); 81 82 static void target_count_increase_nx(struct iter_qstate* iq, int num); 83 84 int 85 iter_init(struct module_env* env, int id) 86 { 87 struct iter_env* iter_env = (struct iter_env*)calloc(1, 88 sizeof(struct iter_env)); 89 if(!iter_env) { 90 log_err("malloc failure"); 91 return 0; 92 } 93 env->modinfo[id] = (void*)iter_env; 94 95 lock_basic_init(&iter_env->queries_ratelimit_lock); 96 lock_protect(&iter_env->queries_ratelimit_lock, 97 &iter_env->num_queries_ratelimited, 98 sizeof(iter_env->num_queries_ratelimited)); 99 100 if(!iter_apply_cfg(iter_env, env->cfg)) { 101 log_err("iterator: could not apply configuration settings."); 102 return 0; 103 } 104 105 return 1; 106 } 107 108 /** delete caps_whitelist element */ 109 static void 110 caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d)) 111 { 112 if(n) { 113 free(((struct name_tree_node*)n)->name); 114 free(n); 115 } 116 } 117 118 void 119 iter_deinit(struct module_env* env, int id) 120 { 121 struct iter_env* iter_env; 122 if(!env || !env->modinfo[id]) 123 return; 124 iter_env = (struct iter_env*)env->modinfo[id]; 125 lock_basic_destroy(&iter_env->queries_ratelimit_lock); 126 free(iter_env->target_fetch_policy); 127 priv_delete(iter_env->priv); 128 donotq_delete(iter_env->donotq); 129 if(iter_env->caps_white) { 130 traverse_postorder(iter_env->caps_white, caps_free, NULL); 131 free(iter_env->caps_white); 132 } 133 free(iter_env); 134 env->modinfo[id] = NULL; 135 } 136 137 /** new query for iterator */ 138 static int 139 iter_new(struct module_qstate* qstate, int id) 140 { 141 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( 142 qstate->region, sizeof(struct iter_qstate)); 143 qstate->minfo[id] = iq; 144 if(!iq) 145 return 0; 146 memset(iq, 0, sizeof(*iq)); 147 iq->state = INIT_REQUEST_STATE; 148 iq->final_state = FINISHED_STATE; 149 iq->an_prepend_list = NULL; 150 iq->an_prepend_last = NULL; 151 iq->ns_prepend_list = NULL; 152 iq->ns_prepend_last = NULL; 153 iq->dp = NULL; 154 iq->depth = 0; 155 iq->num_target_queries = 0; 156 iq->num_current_queries = 0; 157 iq->query_restart_count = 0; 158 iq->referral_count = 0; 159 iq->sent_count = 0; 160 iq->ratelimit_ok = 0; 161 iq->target_count = NULL; 162 iq->dp_target_count = 0; 163 iq->wait_priming_stub = 0; 164 iq->refetch_glue = 0; 165 iq->dnssec_expected = 0; 166 iq->dnssec_lame_query = 0; 167 iq->chase_flags = qstate->query_flags; 168 /* Start with the (current) qname. */ 169 iq->qchase = qstate->qinfo; 170 outbound_list_init(&iq->outlist); 171 iq->minimise_count = 0; 172 iq->timeout_count = 0; 173 if (qstate->env->cfg->qname_minimisation) 174 iq->minimisation_state = INIT_MINIMISE_STATE; 175 else 176 iq->minimisation_state = DONOT_MINIMISE_STATE; 177 178 memset(&iq->qinfo_out, 0, sizeof(struct query_info)); 179 return 1; 180 } 181 182 /** 183 * Transition to the next state. This can be used to advance a currently 184 * processing event. It cannot be used to reactivate a forEvent. 185 * 186 * @param iq: iterator query state 187 * @param nextstate The state to transition to. 188 * @return true. This is so this can be called as the return value for the 189 * actual process*State() methods. (Transitioning to the next state 190 * implies further processing). 191 */ 192 static int 193 next_state(struct iter_qstate* iq, enum iter_state nextstate) 194 { 195 /* If transitioning to a "response" state, make sure that there is a 196 * response */ 197 if(iter_state_is_responsestate(nextstate)) { 198 if(iq->response == NULL) { 199 log_err("transitioning to response state sans " 200 "response."); 201 } 202 } 203 iq->state = nextstate; 204 return 1; 205 } 206 207 /** 208 * Transition an event to its final state. Final states always either return 209 * a result up the module chain, or reactivate a dependent event. Which 210 * final state to transition to is set in the module state for the event when 211 * it was created, and depends on the original purpose of the event. 212 * 213 * The response is stored in the qstate->buf buffer. 214 * 215 * @param iq: iterator query state 216 * @return false. This is so this method can be used as the return value for 217 * the processState methods. (Transitioning to the final state 218 */ 219 static int 220 final_state(struct iter_qstate* iq) 221 { 222 return next_state(iq, iq->final_state); 223 } 224 225 /** 226 * Callback routine to handle errors in parent query states 227 * @param qstate: query state that failed. 228 * @param id: module id. 229 * @param super: super state. 230 */ 231 static void 232 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super) 233 { 234 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 235 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; 236 237 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || 238 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { 239 /* mark address as failed. */ 240 struct delegpt_ns* dpns = NULL; 241 super_iq->num_target_queries--; 242 if(super_iq->dp) 243 dpns = delegpt_find_ns(super_iq->dp, 244 qstate->qinfo.qname, qstate->qinfo.qname_len); 245 if(!dpns) { 246 /* not interested */ 247 /* this can happen, for eg. qname minimisation asked 248 * for an NXDOMAIN to be validated, and used qtype 249 * A for that, and the error of that, the name, is 250 * not listed in super_iq->dp */ 251 verbose(VERB_ALGO, "subq error, but not interested"); 252 log_query_info(VERB_ALGO, "superq", &super->qinfo); 253 return; 254 } else { 255 /* see if the failure did get (parent-lame) info */ 256 if(!cache_fill_missing(super->env, super_iq->qchase.qclass, 257 super->region, super_iq->dp, 0)) 258 log_err("out of memory adding missing"); 259 } 260 delegpt_mark_neg(dpns, qstate->qinfo.qtype); 261 if((dpns->got4 == 2 || (!ie->supports_ipv4 && !ie->use_nat64)) && 262 (dpns->got6 == 2 || !ie->supports_ipv6)) { 263 dpns->resolved = 1; /* mark as failed */ 264 target_count_increase_nx(super_iq, 1); 265 } 266 } 267 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { 268 /* prime failed to get delegation */ 269 super_iq->dp = NULL; 270 } 271 /* evaluate targets again */ 272 super_iq->state = QUERYTARGETS_STATE; 273 /* super becomes runnable, and will process this change */ 274 } 275 276 /** 277 * Return an error to the client 278 * @param qstate: our query state 279 * @param id: module id 280 * @param rcode: error code (DNS errcode). 281 * @return: 0 for use by caller, to make notation easy, like: 282 * return error_response(..). 283 */ 284 static int 285 error_response(struct module_qstate* qstate, int id, int rcode) 286 { 287 verbose(VERB_QUERY, "return error response %s", 288 sldns_lookup_by_id(sldns_rcodes, rcode)? 289 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??"); 290 qstate->return_rcode = rcode; 291 qstate->return_msg = NULL; 292 qstate->ext_state[id] = module_finished; 293 return 0; 294 } 295 296 /** 297 * Return an error to the client and cache the error code in the 298 * message cache (so per qname, qtype, qclass). 299 * @param qstate: our query state 300 * @param id: module id 301 * @param rcode: error code (DNS errcode). 302 * @return: 0 for use by caller, to make notation easy, like: 303 * return error_response(..). 304 */ 305 static int 306 error_response_cache(struct module_qstate* qstate, int id, int rcode) 307 { 308 struct reply_info err; 309 struct msgreply_entry* msg; 310 if(qstate->no_cache_store) { 311 return error_response(qstate, id, rcode); 312 } 313 if(qstate->prefetch_leeway > NORR_TTL) { 314 verbose(VERB_ALGO, "error response for prefetch in cache"); 315 /* attempt to adjust the cache entry prefetch */ 316 if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo, 317 NORR_TTL, qstate->query_flags)) 318 return error_response(qstate, id, rcode); 319 /* if that fails (not in cache), fall through to store err */ 320 } 321 if((msg=msg_cache_lookup(qstate->env, 322 qstate->qinfo.qname, qstate->qinfo.qname_len, 323 qstate->qinfo.qtype, qstate->qinfo.qclass, 324 qstate->query_flags, 0, 325 qstate->env->cfg->serve_expired)) != NULL) { 326 struct reply_info* rep = (struct reply_info*)msg->entry.data; 327 if(qstate->env->cfg->serve_expired && rep) { 328 if(qstate->env->cfg->serve_expired_ttl_reset && 329 *qstate->env->now + qstate->env->cfg->serve_expired_ttl 330 > rep->serve_expired_ttl) { 331 verbose(VERB_ALGO, "reset serve-expired-ttl for " 332 "response in cache"); 333 rep->serve_expired_ttl = *qstate->env->now + 334 qstate->env->cfg->serve_expired_ttl; 335 } 336 verbose(VERB_ALGO, "set serve-expired-norec-ttl for " 337 "response in cache"); 338 rep->serve_expired_norec_ttl = NORR_TTL + 339 *qstate->env->now; 340 } 341 if(rep && (FLAGS_GET_RCODE(rep->flags) == 342 LDNS_RCODE_NOERROR || 343 FLAGS_GET_RCODE(rep->flags) == 344 LDNS_RCODE_NXDOMAIN || 345 FLAGS_GET_RCODE(rep->flags) == 346 LDNS_RCODE_YXDOMAIN) && 347 (qstate->env->cfg->serve_expired || 348 *qstate->env->now <= rep->ttl)) { 349 /* we have a good entry, don't overwrite */ 350 lock_rw_unlock(&msg->entry.lock); 351 return error_response(qstate, id, rcode); 352 } 353 lock_rw_unlock(&msg->entry.lock); 354 /* nothing interesting is cached (already error response or 355 * expired good record when we don't serve expired), so this 356 * servfail cache entry is useful (stops waste of time on this 357 * servfail NORR_TTL) */ 358 } 359 /* store in cache */ 360 memset(&err, 0, sizeof(err)); 361 err.flags = (uint16_t)(BIT_QR | BIT_RA); 362 FLAGS_SET_RCODE(err.flags, rcode); 363 err.qdcount = 1; 364 err.ttl = NORR_TTL; 365 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); 366 err.serve_expired_ttl = NORR_TTL; 367 /* do not waste time trying to validate this servfail */ 368 err.security = sec_status_indeterminate; 369 verbose(VERB_ALGO, "store error response in message cache"); 370 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL, 371 qstate->query_flags, qstate->qstarttime); 372 return error_response(qstate, id, rcode); 373 } 374 375 /** check if prepend item is duplicate item */ 376 static int 377 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, 378 struct ub_packed_rrset_key* dup) 379 { 380 size_t i; 381 for(i=0; i<to; i++) { 382 if(sets[i]->rk.type == dup->rk.type && 383 sets[i]->rk.rrset_class == dup->rk.rrset_class && 384 sets[i]->rk.dname_len == dup->rk.dname_len && 385 query_dname_compare(sets[i]->rk.dname, dup->rk.dname) 386 == 0) 387 return 1; 388 } 389 return 0; 390 } 391 392 /** prepend the prepend list in the answer and authority section of dns_msg */ 393 static int 394 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg, 395 struct regional* region) 396 { 397 struct iter_prep_list* p; 398 struct ub_packed_rrset_key** sets; 399 size_t num_an = 0, num_ns = 0;; 400 for(p = iq->an_prepend_list; p; p = p->next) 401 num_an++; 402 for(p = iq->ns_prepend_list; p; p = p->next) 403 num_ns++; 404 if(num_an + num_ns == 0) 405 return 1; 406 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); 407 if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX || 408 msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */ 409 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * 410 sizeof(struct ub_packed_rrset_key*)); 411 if(!sets) 412 return 0; 413 /* ANSWER section */ 414 num_an = 0; 415 for(p = iq->an_prepend_list; p; p = p->next) { 416 sets[num_an++] = p->rrset; 417 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl) { 418 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset); 419 msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl); 420 msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL; 421 } 422 } 423 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * 424 sizeof(struct ub_packed_rrset_key*)); 425 /* AUTH section */ 426 num_ns = 0; 427 for(p = iq->ns_prepend_list; p; p = p->next) { 428 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, 429 num_ns, p->rrset) || prepend_is_duplicate( 430 msg->rep->rrsets+msg->rep->an_numrrsets, 431 msg->rep->ns_numrrsets, p->rrset)) 432 continue; 433 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; 434 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl) { 435 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset); 436 msg->rep->prefetch_ttl = PREFETCH_TTL_CALC(msg->rep->ttl); 437 msg->rep->serve_expired_ttl = msg->rep->ttl + SERVE_EXPIRED_TTL; 438 } 439 } 440 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, 441 msg->rep->rrsets + msg->rep->an_numrrsets, 442 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * 443 sizeof(struct ub_packed_rrset_key*)); 444 445 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because 446 * this is what recursors should give. */ 447 msg->rep->rrset_count += num_an + num_ns; 448 msg->rep->an_numrrsets += num_an; 449 msg->rep->ns_numrrsets += num_ns; 450 msg->rep->rrsets = sets; 451 return 1; 452 } 453 454 /** 455 * Find rrset in ANSWER prepend list. 456 * to avoid duplicate DNAMEs when a DNAME is traversed twice. 457 * @param iq: iterator query state. 458 * @param rrset: rrset to add. 459 * @return false if not found 460 */ 461 static int 462 iter_find_rrset_in_prepend_answer(struct iter_qstate* iq, 463 struct ub_packed_rrset_key* rrset) 464 { 465 struct iter_prep_list* p = iq->an_prepend_list; 466 while(p) { 467 if(ub_rrset_compare(p->rrset, rrset) == 0 && 468 rrsetdata_equal((struct packed_rrset_data*)p->rrset 469 ->entry.data, (struct packed_rrset_data*)rrset 470 ->entry.data)) 471 return 1; 472 p = p->next; 473 } 474 return 0; 475 } 476 477 /** 478 * Add rrset to ANSWER prepend list 479 * @param qstate: query state. 480 * @param iq: iterator query state. 481 * @param rrset: rrset to add. 482 * @return false on failure (malloc). 483 */ 484 static int 485 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, 486 struct ub_packed_rrset_key* rrset) 487 { 488 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 489 qstate->region, sizeof(struct iter_prep_list)); 490 if(!p) 491 return 0; 492 p->rrset = rrset; 493 p->next = NULL; 494 /* add at end */ 495 if(iq->an_prepend_last) 496 iq->an_prepend_last->next = p; 497 else iq->an_prepend_list = p; 498 iq->an_prepend_last = p; 499 return 1; 500 } 501 502 /** 503 * Add rrset to AUTHORITY prepend list 504 * @param qstate: query state. 505 * @param iq: iterator query state. 506 * @param rrset: rrset to add. 507 * @return false on failure (malloc). 508 */ 509 static int 510 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, 511 struct ub_packed_rrset_key* rrset) 512 { 513 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 514 qstate->region, sizeof(struct iter_prep_list)); 515 if(!p) 516 return 0; 517 p->rrset = rrset; 518 p->next = NULL; 519 /* add at end */ 520 if(iq->ns_prepend_last) 521 iq->ns_prepend_last->next = p; 522 else iq->ns_prepend_list = p; 523 iq->ns_prepend_last = p; 524 return 1; 525 } 526 527 /** 528 * Given a CNAME response (defined as a response containing a CNAME or DNAME 529 * that does not answer the request), process the response, modifying the 530 * state as necessary. This follows the CNAME/DNAME chain and returns the 531 * final query name. 532 * 533 * sets the new query name, after following the CNAME/DNAME chain. 534 * @param qstate: query state. 535 * @param iq: iterator query state. 536 * @param msg: the response. 537 * @param mname: returned target new query name. 538 * @param mname_len: length of mname. 539 * @return false on (malloc) error. 540 */ 541 static int 542 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, 543 struct dns_msg* msg, uint8_t** mname, size_t* mname_len) 544 { 545 size_t i; 546 /* Start with the (current) qname. */ 547 *mname = iq->qchase.qname; 548 *mname_len = iq->qchase.qname_len; 549 550 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and 551 * DNAMES. */ 552 for(i=0; i<msg->rep->an_numrrsets; i++) { 553 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 554 /* If there is a (relevant) DNAME, add it to the list. 555 * We always expect there to be CNAME that was generated 556 * by this DNAME following, so we don't process the DNAME 557 * directly. */ 558 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && 559 dname_strict_subdomain_c(*mname, r->rk.dname) && 560 !iter_find_rrset_in_prepend_answer(iq, r)) { 561 if(!iter_add_prepend_answer(qstate, iq, r)) 562 return 0; 563 continue; 564 } 565 566 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && 567 query_dname_compare(*mname, r->rk.dname) == 0 && 568 !iter_find_rrset_in_prepend_answer(iq, r)) { 569 /* Add this relevant CNAME rrset to the prepend list.*/ 570 if(!iter_add_prepend_answer(qstate, iq, r)) 571 return 0; 572 get_cname_target(r, mname, mname_len); 573 } 574 575 /* Other rrsets in the section are ignored. */ 576 } 577 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ 578 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + 579 msg->rep->ns_numrrsets; i++) { 580 struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 581 /* only add NSEC/NSEC3, as they may be needed for validation */ 582 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC || 583 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { 584 if(!iter_add_prepend_auth(qstate, iq, r)) 585 return 0; 586 } 587 } 588 return 1; 589 } 590 591 /** fill fail address for later recovery */ 592 static void 593 fill_fail_addr(struct iter_qstate* iq, struct sockaddr_storage* addr, 594 socklen_t addrlen) 595 { 596 if(addrlen == 0) { 597 iq->fail_addr_type = 0; 598 return; 599 } 600 if(((struct sockaddr_in*)addr)->sin_family == AF_INET) { 601 iq->fail_addr_type = 4; 602 memcpy(&iq->fail_addr.in, 603 &((struct sockaddr_in*)addr)->sin_addr, 604 sizeof(iq->fail_addr.in)); 605 } 606 #ifdef AF_INET6 607 else if(((struct sockaddr_in*)addr)->sin_family == AF_INET6) { 608 iq->fail_addr_type = 6; 609 memcpy(&iq->fail_addr.in6, 610 &((struct sockaddr_in6*)addr)->sin6_addr, 611 sizeof(iq->fail_addr.in6)); 612 } 613 #endif 614 else { 615 iq->fail_addr_type = 0; 616 } 617 } 618 619 /** print fail addr to string */ 620 static void 621 print_fail_addr(struct iter_qstate* iq, char* buf, size_t len) 622 { 623 if(iq->fail_addr_type == 4) { 624 if(inet_ntop(AF_INET, &iq->fail_addr.in, buf, 625 (socklen_t)len) == 0) 626 (void)strlcpy(buf, "(inet_ntop error)", len); 627 } 628 #ifdef AF_INET6 629 else if(iq->fail_addr_type == 6) { 630 if(inet_ntop(AF_INET6, &iq->fail_addr.in6, buf, 631 (socklen_t)len) == 0) 632 (void)strlcpy(buf, "(inet_ntop error)", len); 633 } 634 #endif 635 else 636 (void)strlcpy(buf, "", len); 637 } 638 639 /** add response specific error information for log servfail */ 640 static void 641 errinf_reply(struct module_qstate* qstate, struct iter_qstate* iq) 642 { 643 if(qstate->env->cfg->val_log_level < 2 && !qstate->env->cfg->log_servfail) 644 return; 645 if((qstate->reply && qstate->reply->remote_addrlen != 0) || 646 (iq->fail_addr_type != 0)) { 647 char from[256], frm[512]; 648 if(qstate->reply && qstate->reply->remote_addrlen != 0) 649 addr_to_str(&qstate->reply->remote_addr, 650 qstate->reply->remote_addrlen, from, 651 sizeof(from)); 652 else 653 print_fail_addr(iq, from, sizeof(from)); 654 snprintf(frm, sizeof(frm), "from %s", from); 655 errinf(qstate, frm); 656 } 657 if(iq->scrub_failures || iq->parse_failures) { 658 if(iq->scrub_failures) 659 errinf(qstate, "upstream response failed scrub"); 660 if(iq->parse_failures) 661 errinf(qstate, "could not parse upstream response"); 662 } else if(iq->response == NULL && iq->timeout_count != 0) { 663 errinf(qstate, "upstream server timeout"); 664 } else if(iq->response == NULL) { 665 errinf(qstate, "no server to query"); 666 if(iq->dp) { 667 if(iq->dp->target_list == NULL) 668 errinf(qstate, "no addresses for nameservers"); 669 else errinf(qstate, "nameserver addresses not usable"); 670 if(iq->dp->nslist == NULL) 671 errinf(qstate, "have no nameserver names"); 672 if(iq->dp->bogus) 673 errinf(qstate, "NS record was dnssec bogus"); 674 } 675 } 676 if(iq->response && iq->response->rep) { 677 if(FLAGS_GET_RCODE(iq->response->rep->flags) != 0) { 678 char rcode[256], rc[32]; 679 (void)sldns_wire2str_rcode_buf( 680 FLAGS_GET_RCODE(iq->response->rep->flags), 681 rc, sizeof(rc)); 682 snprintf(rcode, sizeof(rcode), "got %s", rc); 683 errinf(qstate, rcode); 684 } else { 685 /* rcode NOERROR */ 686 if(iq->response->rep->an_numrrsets == 0) { 687 errinf(qstate, "nodata answer"); 688 } 689 } 690 } 691 } 692 693 /** see if last resort is possible - does config allow queries to parent */ 694 static int 695 can_have_last_resort(struct module_env* env, uint8_t* nm, size_t ATTR_UNUSED(nmlen), 696 uint16_t qclass, int* have_dp, struct delegpt** retdp, 697 struct regional* region) 698 { 699 struct delegpt* dp = NULL; 700 int nolock = 0; 701 /* do not process a last resort (the parent side) if a stub 702 * or forward is configured, because we do not want to go 'above' 703 * the configured servers */ 704 if(!dname_is_root(nm) && 705 (dp = hints_find(env->hints, nm, qclass, nolock)) && 706 /* has_parent side is turned off for stub_first, where we 707 * are allowed to go to the parent */ 708 dp->has_parent_side_NS) { 709 if(retdp) *retdp = delegpt_copy(dp, region); 710 lock_rw_unlock(&env->hints->lock); 711 if(have_dp) *have_dp = 1; 712 return 0; 713 } 714 if(dp) { 715 lock_rw_unlock(&env->hints->lock); 716 dp = NULL; 717 } 718 if((dp = forwards_find(env->fwds, nm, qclass, nolock)) && 719 /* has_parent_side is turned off for forward_first, where 720 * we are allowed to go to the parent */ 721 dp->has_parent_side_NS) { 722 if(retdp) *retdp = delegpt_copy(dp, region); 723 lock_rw_unlock(&env->fwds->lock); 724 if(have_dp) *have_dp = 1; 725 return 0; 726 } 727 /* lock_() calls are macros that could be nothing, surround in {} */ 728 if(dp) { lock_rw_unlock(&env->fwds->lock); } 729 return 1; 730 } 731 732 /** see if target name is caps-for-id whitelisted */ 733 static int 734 is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq) 735 { 736 if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */ 737 return name_tree_lookup(ie->caps_white, iq->qchase.qname, 738 iq->qchase.qname_len, dname_count_labels(iq->qchase.qname), 739 iq->qchase.qclass) != NULL; 740 } 741 742 /** 743 * Create target count structure for this query. This is always explicitly 744 * created for the parent query. 745 */ 746 static void 747 target_count_create(struct iter_qstate* iq) 748 { 749 if(!iq->target_count) { 750 iq->target_count = (int*)calloc(TARGET_COUNT_MAX, sizeof(int)); 751 /* if calloc fails we simply do not track this number */ 752 if(iq->target_count) { 753 iq->target_count[TARGET_COUNT_REF] = 1; 754 iq->nxns_dp = (uint8_t**)calloc(1, sizeof(uint8_t*)); 755 } 756 } 757 } 758 759 static void 760 target_count_increase(struct iter_qstate* iq, int num) 761 { 762 target_count_create(iq); 763 if(iq->target_count) 764 iq->target_count[TARGET_COUNT_QUERIES] += num; 765 iq->dp_target_count++; 766 } 767 768 static void 769 target_count_increase_nx(struct iter_qstate* iq, int num) 770 { 771 target_count_create(iq); 772 if(iq->target_count) 773 iq->target_count[TARGET_COUNT_NX] += num; 774 } 775 776 static void 777 target_count_increase_global_quota(struct iter_qstate* iq, int num) 778 { 779 target_count_create(iq); 780 if(iq->target_count) 781 iq->target_count[TARGET_COUNT_GLOBAL_QUOTA] += num; 782 } 783 784 /** 785 * Generate a subrequest. 786 * Generate a local request event. Local events are tied to this module, and 787 * have a corresponding (first tier) event that is waiting for this event to 788 * resolve to continue. 789 * 790 * @param qname The query name for this request. 791 * @param qnamelen length of qname 792 * @param qtype The query type for this request. 793 * @param qclass The query class for this request. 794 * @param qstate The event that is generating this event. 795 * @param id: module id. 796 * @param iq: The iterator state that is generating this event. 797 * @param initial_state The initial response state (normally this 798 * is QUERY_RESP_STATE, unless it is known that the request won't 799 * need iterative processing 800 * @param finalstate The final state for the response to this request. 801 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does 802 * not need initialisation. 803 * @param v: if true, validation is done on the subquery. 804 * @param detached: true if this qstate should not attach to the subquery 805 * @return false on error (malloc). 806 */ 807 static int 808 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, 809 uint16_t qclass, struct module_qstate* qstate, int id, 810 struct iter_qstate* iq, enum iter_state initial_state, 811 enum iter_state finalstate, struct module_qstate** subq_ret, int v, 812 int detached) 813 { 814 struct module_qstate* subq = NULL; 815 struct iter_qstate* subiq = NULL; 816 uint16_t qflags = 0; /* OPCODE QUERY, no flags */ 817 struct query_info qinf; 818 int prime = (finalstate == PRIME_RESP_STATE)?1:0; 819 int valrec = 0; 820 qinf.qname = qname; 821 qinf.qname_len = qnamelen; 822 qinf.qtype = qtype; 823 qinf.qclass = qclass; 824 qinf.local_alias = NULL; 825 826 /* RD should be set only when sending the query back through the INIT 827 * state. */ 828 if(initial_state == INIT_REQUEST_STATE) 829 qflags |= BIT_RD; 830 /* We set the CD flag so we can send this through the "head" of 831 * the resolution chain, which might have a validator. We are 832 * uninterested in validating things not on the direct resolution 833 * path. */ 834 if(!v) { 835 qflags |= BIT_CD; 836 valrec = 1; 837 } 838 839 if(detached) { 840 struct mesh_state* sub = NULL; 841 fptr_ok(fptr_whitelist_modenv_add_sub( 842 qstate->env->add_sub)); 843 if(!(*qstate->env->add_sub)(qstate, &qinf, 844 qflags, prime, valrec, &subq, &sub)){ 845 return 0; 846 } 847 } 848 else { 849 /* attach subquery, lookup existing or make a new one */ 850 fptr_ok(fptr_whitelist_modenv_attach_sub( 851 qstate->env->attach_sub)); 852 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, 853 valrec, &subq)) { 854 return 0; 855 } 856 } 857 *subq_ret = subq; 858 if(subq) { 859 /* initialise the new subquery */ 860 subq->curmod = id; 861 subq->ext_state[id] = module_state_initial; 862 subq->minfo[id] = regional_alloc(subq->region, 863 sizeof(struct iter_qstate)); 864 if(!subq->minfo[id]) { 865 log_err("init subq: out of memory"); 866 fptr_ok(fptr_whitelist_modenv_kill_sub( 867 qstate->env->kill_sub)); 868 (*qstate->env->kill_sub)(subq); 869 return 0; 870 } 871 subiq = (struct iter_qstate*)subq->minfo[id]; 872 memset(subiq, 0, sizeof(*subiq)); 873 subiq->num_target_queries = 0; 874 target_count_create(iq); 875 subiq->target_count = iq->target_count; 876 if(iq->target_count) { 877 iq->target_count[TARGET_COUNT_REF] ++; /* extra reference */ 878 subiq->nxns_dp = iq->nxns_dp; 879 } 880 subiq->dp_target_count = 0; 881 subiq->num_current_queries = 0; 882 subiq->depth = iq->depth+1; 883 outbound_list_init(&subiq->outlist); 884 subiq->state = initial_state; 885 subiq->final_state = finalstate; 886 subiq->qchase = subq->qinfo; 887 subiq->chase_flags = subq->query_flags; 888 subiq->refetch_glue = 0; 889 if(qstate->env->cfg->qname_minimisation) 890 subiq->minimisation_state = INIT_MINIMISE_STATE; 891 else 892 subiq->minimisation_state = DONOT_MINIMISE_STATE; 893 memset(&subiq->qinfo_out, 0, sizeof(struct query_info)); 894 } 895 return 1; 896 } 897 898 /** 899 * Generate and send a root priming request. 900 * @param qstate: the qtstate that triggered the need to prime. 901 * @param iq: iterator query state. 902 * @param id: module id. 903 * @param qclass: the class to prime. 904 * @return 0 on failure 905 */ 906 static int 907 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id, 908 uint16_t qclass) 909 { 910 struct delegpt* dp; 911 struct module_qstate* subq; 912 int nolock = 0; 913 verbose(VERB_DETAIL, "priming . %s NS", 914 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)? 915 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??"); 916 dp = hints_find_root(qstate->env->hints, qclass, nolock); 917 if(!dp) { 918 verbose(VERB_ALGO, "Cannot prime due to lack of hints"); 919 return 0; 920 } 921 /* Priming requests start at the QUERYTARGETS state, skipping 922 * the normal INIT state logic (which would cause an infloop). */ 923 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, 924 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE, 925 &subq, 0, 0)) { 926 lock_rw_unlock(&qstate->env->hints->lock); 927 verbose(VERB_ALGO, "could not prime root"); 928 return 0; 929 } 930 if(subq) { 931 struct iter_qstate* subiq = 932 (struct iter_qstate*)subq->minfo[id]; 933 /* Set the initial delegation point to the hint. 934 * copy dp, it is now part of the root prime query. 935 * dp was part of in the fixed hints structure. */ 936 subiq->dp = delegpt_copy(dp, subq->region); 937 lock_rw_unlock(&qstate->env->hints->lock); 938 if(!subiq->dp) { 939 log_err("out of memory priming root, copydp"); 940 fptr_ok(fptr_whitelist_modenv_kill_sub( 941 qstate->env->kill_sub)); 942 (*qstate->env->kill_sub)(subq); 943 return 0; 944 } 945 /* there should not be any target queries. */ 946 subiq->num_target_queries = 0; 947 subiq->dnssec_expected = iter_indicates_dnssec( 948 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 949 } else { 950 lock_rw_unlock(&qstate->env->hints->lock); 951 } 952 953 /* this module stops, our submodule starts, and does the query. */ 954 qstate->ext_state[id] = module_wait_subquery; 955 return 1; 956 } 957 958 /** 959 * Generate and process a stub priming request. This method tests for the 960 * need to prime a stub zone, so it is safe to call for every request. 961 * 962 * @param qstate: the qtstate that triggered the need to prime. 963 * @param iq: iterator query state. 964 * @param id: module id. 965 * @param qname: request name. 966 * @param qclass: request class. 967 * @return true if a priming subrequest was made, false if not. The will only 968 * issue a priming request if it detects an unprimed stub. 969 * Uses value of 2 to signal during stub-prime in root-prime situation 970 * that a noprime-stub is available and resolution can continue. 971 */ 972 static int 973 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id, 974 uint8_t* qname, uint16_t qclass) 975 { 976 /* Lookup the stub hint. This will return null if the stub doesn't 977 * need to be re-primed. */ 978 struct iter_hints_stub* stub; 979 struct delegpt* stub_dp; 980 struct module_qstate* subq; 981 int nolock = 0; 982 983 if(!qname) return 0; 984 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp, 985 nolock); 986 /* The stub (if there is one) does not need priming. */ 987 if(!stub) return 0; 988 stub_dp = stub->dp; 989 /* if we have an auth_zone dp, and stub is equal, don't prime stub 990 * yet, unless we want to fallback and avoid the auth_zone */ 991 if(!iq->auth_zone_avoid && iq->dp && iq->dp->auth_dp && 992 query_dname_compare(iq->dp->name, stub_dp->name) == 0) { 993 lock_rw_unlock(&qstate->env->hints->lock); 994 return 0; 995 } 996 997 /* is it a noprime stub (always use) */ 998 if(stub->noprime) { 999 int r = 0; 1000 if(iq->dp == NULL) r = 2; 1001 /* copy the dp out of the fixed hints structure, so that 1002 * it can be changed when servicing this query */ 1003 iq->dp = delegpt_copy(stub_dp, qstate->region); 1004 lock_rw_unlock(&qstate->env->hints->lock); 1005 if(!iq->dp) { 1006 log_err("out of memory priming stub"); 1007 errinf(qstate, "malloc failure, priming stub"); 1008 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1009 return 1; /* return 1 to make module stop, with error */ 1010 } 1011 log_nametypeclass(VERB_DETAIL, "use stub", iq->dp->name, 1012 LDNS_RR_TYPE_NS, qclass); 1013 return r; 1014 } 1015 1016 /* Otherwise, we need to (re)prime the stub. */ 1017 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name, 1018 LDNS_RR_TYPE_NS, qclass); 1019 1020 /* Stub priming events start at the QUERYTARGETS state to avoid the 1021 * redundant INIT state processing. */ 1022 if(!generate_sub_request(stub_dp->name, stub_dp->namelen, 1023 LDNS_RR_TYPE_NS, qclass, qstate, id, iq, 1024 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0, 0)) { 1025 lock_rw_unlock(&qstate->env->hints->lock); 1026 verbose(VERB_ALGO, "could not prime stub"); 1027 errinf(qstate, "could not generate lookup for stub prime"); 1028 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1029 return 1; /* return 1 to make module stop, with error */ 1030 } 1031 if(subq) { 1032 struct iter_qstate* subiq = 1033 (struct iter_qstate*)subq->minfo[id]; 1034 1035 /* Set the initial delegation point to the hint. */ 1036 /* make copy to avoid use of stub dp by different qs/threads */ 1037 subiq->dp = delegpt_copy(stub_dp, subq->region); 1038 lock_rw_unlock(&qstate->env->hints->lock); 1039 if(!subiq->dp) { 1040 log_err("out of memory priming stub, copydp"); 1041 fptr_ok(fptr_whitelist_modenv_kill_sub( 1042 qstate->env->kill_sub)); 1043 (*qstate->env->kill_sub)(subq); 1044 errinf(qstate, "malloc failure, in stub prime"); 1045 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1046 return 1; /* return 1 to make module stop, with error */ 1047 } 1048 /* there should not be any target queries -- although there 1049 * wouldn't be anyway, since stub hints never have 1050 * missing targets. */ 1051 subiq->num_target_queries = 0; 1052 subiq->wait_priming_stub = 1; 1053 subiq->dnssec_expected = iter_indicates_dnssec( 1054 qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 1055 } else { 1056 lock_rw_unlock(&qstate->env->hints->lock); 1057 } 1058 1059 /* this module stops, our submodule starts, and does the query. */ 1060 qstate->ext_state[id] = module_wait_subquery; 1061 return 1; 1062 } 1063 1064 /** 1065 * Generate a delegation point for an auth zone (unless cached dp is better) 1066 * false on alloc failure. 1067 */ 1068 static int 1069 auth_zone_delegpt(struct module_qstate* qstate, struct iter_qstate* iq, 1070 uint8_t* delname, size_t delnamelen) 1071 { 1072 struct auth_zone* z; 1073 if(iq->auth_zone_avoid) 1074 return 1; 1075 if(!delname) { 1076 delname = iq->qchase.qname; 1077 delnamelen = iq->qchase.qname_len; 1078 } 1079 lock_rw_rdlock(&qstate->env->auth_zones->lock); 1080 z = auth_zones_find_zone(qstate->env->auth_zones, delname, delnamelen, 1081 qstate->qinfo.qclass); 1082 if(!z) { 1083 lock_rw_unlock(&qstate->env->auth_zones->lock); 1084 return 1; 1085 } 1086 lock_rw_rdlock(&z->lock); 1087 lock_rw_unlock(&qstate->env->auth_zones->lock); 1088 if(z->for_upstream) { 1089 if(iq->dp && query_dname_compare(z->name, iq->dp->name) == 0 1090 && iq->dp->auth_dp && qstate->blacklist && 1091 z->fallback_enabled) { 1092 /* cache is blacklisted and fallback, and we 1093 * already have an auth_zone dp */ 1094 if(verbosity>=VERB_ALGO) { 1095 char buf[255+1]; 1096 dname_str(z->name, buf); 1097 verbose(VERB_ALGO, "auth_zone %s " 1098 "fallback because cache blacklisted", 1099 buf); 1100 } 1101 lock_rw_unlock(&z->lock); 1102 iq->dp = NULL; 1103 return 1; 1104 } 1105 if(iq->dp==NULL || dname_subdomain_c(z->name, iq->dp->name)) { 1106 struct delegpt* dp; 1107 if(qstate->blacklist && z->fallback_enabled) { 1108 /* cache is blacklisted because of a DNSSEC 1109 * validation failure, and the zone allows 1110 * fallback to the internet, query there. */ 1111 if(verbosity>=VERB_ALGO) { 1112 char buf[255+1]; 1113 dname_str(z->name, buf); 1114 verbose(VERB_ALGO, "auth_zone %s " 1115 "fallback because cache blacklisted", 1116 buf); 1117 } 1118 lock_rw_unlock(&z->lock); 1119 return 1; 1120 } 1121 dp = (struct delegpt*)regional_alloc_zero( 1122 qstate->region, sizeof(*dp)); 1123 if(!dp) { 1124 log_err("alloc failure"); 1125 if(z->fallback_enabled) { 1126 lock_rw_unlock(&z->lock); 1127 return 1; /* just fallback */ 1128 } 1129 lock_rw_unlock(&z->lock); 1130 errinf(qstate, "malloc failure"); 1131 return 0; 1132 } 1133 dp->name = regional_alloc_init(qstate->region, 1134 z->name, z->namelen); 1135 if(!dp->name) { 1136 log_err("alloc failure"); 1137 if(z->fallback_enabled) { 1138 lock_rw_unlock(&z->lock); 1139 return 1; /* just fallback */ 1140 } 1141 lock_rw_unlock(&z->lock); 1142 errinf(qstate, "malloc failure"); 1143 return 0; 1144 } 1145 dp->namelen = z->namelen; 1146 dp->namelabs = z->namelabs; 1147 dp->auth_dp = 1; 1148 iq->dp = dp; 1149 } 1150 } 1151 1152 lock_rw_unlock(&z->lock); 1153 return 1; 1154 } 1155 1156 /** 1157 * Generate A and AAAA checks for glue that is in-zone for the referral 1158 * we just got to obtain authoritative information on the addresses. 1159 * 1160 * @param qstate: the qtstate that triggered the need to prime. 1161 * @param iq: iterator query state. 1162 * @param id: module id. 1163 */ 1164 static void 1165 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq, 1166 int id) 1167 { 1168 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 1169 struct module_qstate* subq; 1170 size_t i; 1171 struct reply_info* rep = iq->response->rep; 1172 struct ub_packed_rrset_key* s; 1173 log_assert(iq->dp); 1174 1175 if(iq->depth == ie->max_dependency_depth) 1176 return; 1177 /* walk through additional, and check if in-zone, 1178 * only relevant A, AAAA are left after scrub anyway */ 1179 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { 1180 s = rep->rrsets[i]; 1181 /* check *ALL* addresses that are transmitted in additional*/ 1182 /* is it an address ? */ 1183 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A || 1184 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) { 1185 continue; 1186 } 1187 /* is this query the same as the A/AAAA check for it */ 1188 if(qstate->qinfo.qtype == ntohs(s->rk.type) && 1189 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) && 1190 query_dname_compare(qstate->qinfo.qname, 1191 s->rk.dname)==0 && 1192 (qstate->query_flags&BIT_RD) && 1193 !(qstate->query_flags&BIT_CD)) 1194 continue; 1195 1196 /* generate subrequest for it */ 1197 log_nametypeclass(VERB_ALGO, "schedule addr fetch", 1198 s->rk.dname, ntohs(s->rk.type), 1199 ntohs(s->rk.rrset_class)); 1200 if(!generate_sub_request(s->rk.dname, s->rk.dname_len, 1201 ntohs(s->rk.type), ntohs(s->rk.rrset_class), 1202 qstate, id, iq, 1203 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) { 1204 verbose(VERB_ALGO, "could not generate addr check"); 1205 return; 1206 } 1207 /* ignore subq - not need for more init */ 1208 } 1209 } 1210 1211 /** 1212 * Generate a NS check request to obtain authoritative information 1213 * on an NS rrset. 1214 * 1215 * @param qstate: the qstate that triggered the need to prime. 1216 * @param iq: iterator query state. 1217 * @param id: module id. 1218 */ 1219 static void 1220 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id) 1221 { 1222 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 1223 struct module_qstate* subq; 1224 log_assert(iq->dp); 1225 1226 if(iq->depth == ie->max_dependency_depth) 1227 return; 1228 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, 1229 iq->qchase.qclass, NULL, NULL, NULL)) 1230 return; 1231 /* is this query the same as the nscheck? */ 1232 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS && 1233 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 1234 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 1235 /* spawn off A, AAAA queries for in-zone glue to check */ 1236 generate_a_aaaa_check(qstate, iq, id); 1237 return; 1238 } 1239 /* no need to get the NS record for DS, it is above the zonecut */ 1240 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS) 1241 return; 1242 1243 log_nametypeclass(VERB_ALGO, "schedule ns fetch", 1244 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 1245 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 1246 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 1247 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) { 1248 verbose(VERB_ALGO, "could not generate ns check"); 1249 return; 1250 } 1251 if(subq) { 1252 struct iter_qstate* subiq = 1253 (struct iter_qstate*)subq->minfo[id]; 1254 1255 /* make copy to avoid use of stub dp by different qs/threads */ 1256 /* refetch glue to start higher up the tree */ 1257 subiq->refetch_glue = 1; 1258 subiq->dp = delegpt_copy(iq->dp, subq->region); 1259 if(!subiq->dp) { 1260 log_err("out of memory generating ns check, copydp"); 1261 fptr_ok(fptr_whitelist_modenv_kill_sub( 1262 qstate->env->kill_sub)); 1263 (*qstate->env->kill_sub)(subq); 1264 return; 1265 } 1266 } 1267 } 1268 1269 /** 1270 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we 1271 * just got in a referral (where we have dnssec_expected, thus have trust 1272 * anchors above it). Note that right after calling this routine the 1273 * iterator detached subqueries (because of following the referral), and thus 1274 * the DNSKEY query becomes detached, its return stored in the cache for 1275 * later lookup by the validator. This cache lookup by the validator avoids 1276 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now 1277 * performed at about the same time the original query is sent to the domain, 1278 * thus the two answers are likely to be returned at about the same time, 1279 * saving a roundtrip from the validated lookup. 1280 * 1281 * @param qstate: the qtstate that triggered the need to prime. 1282 * @param iq: iterator query state. 1283 * @param id: module id. 1284 */ 1285 static void 1286 generate_dnskey_prefetch(struct module_qstate* qstate, 1287 struct iter_qstate* iq, int id) 1288 { 1289 struct module_qstate* subq; 1290 log_assert(iq->dp); 1291 1292 /* is this query the same as the prefetch? */ 1293 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY && 1294 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 1295 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 1296 return; 1297 } 1298 /* we do not generate this prefetch when the query list is full, 1299 * the query is fetched, if needed, when the validator wants it. 1300 * At that time the validator waits for it, after spawning it. 1301 * This means there is one state that uses cpu and a socket, the 1302 * spawned while this one waits, and not several at the same time, 1303 * if we had created the lookup here. And this helps to keep 1304 * the total load down, but the query still succeeds to resolve. */ 1305 if(mesh_jostle_exceeded(qstate->env->mesh)) 1306 return; 1307 1308 /* if the DNSKEY is in the cache this lookup will stop quickly */ 1309 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch", 1310 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass); 1311 if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 1312 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq, 1313 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) { 1314 /* we'll be slower, but it'll work */ 1315 verbose(VERB_ALGO, "could not generate dnskey prefetch"); 1316 return; 1317 } 1318 if(subq) { 1319 struct iter_qstate* subiq = 1320 (struct iter_qstate*)subq->minfo[id]; 1321 /* this qstate has the right delegation for the dnskey lookup*/ 1322 /* make copy to avoid use of stub dp by different qs/threads */ 1323 subiq->dp = delegpt_copy(iq->dp, subq->region); 1324 /* if !subiq->dp, it'll start from the cache, no problem */ 1325 } 1326 } 1327 1328 /** 1329 * See if the query needs forwarding. 1330 * 1331 * @param qstate: query state. 1332 * @param iq: iterator query state. 1333 * @return true if the request is forwarded, false if not. 1334 * If returns true but, iq->dp is NULL then a malloc failure occurred. 1335 */ 1336 static int 1337 forward_request(struct module_qstate* qstate, struct iter_qstate* iq) 1338 { 1339 struct delegpt* dp; 1340 uint8_t* delname = iq->qchase.qname; 1341 size_t delnamelen = iq->qchase.qname_len; 1342 int nolock = 0; 1343 if(iq->refetch_glue && iq->dp) { 1344 delname = iq->dp->name; 1345 delnamelen = iq->dp->namelen; 1346 } 1347 /* strip one label off of DS query to lookup higher for it */ 1348 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) 1349 && !dname_is_root(iq->qchase.qname)) 1350 dname_remove_label(&delname, &delnamelen); 1351 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass, 1352 nolock); 1353 if(!dp) return 0; 1354 /* send recursion desired to forward addr */ 1355 iq->chase_flags |= BIT_RD; 1356 iq->dp = delegpt_copy(dp, qstate->region); 1357 lock_rw_unlock(&qstate->env->fwds->lock); 1358 /* iq->dp checked by caller */ 1359 verbose(VERB_ALGO, "forwarding request"); 1360 return 1; 1361 } 1362 1363 /** 1364 * Process the initial part of the request handling. This state roughly 1365 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2 1366 * (find the best servers to ask). 1367 * 1368 * Note that all requests start here, and query restarts revisit this state. 1369 * 1370 * This state either generates: 1) a response, from cache or error, 2) a 1371 * priming event, or 3) forwards the request to the next state (init2, 1372 * generally). 1373 * 1374 * @param qstate: query state. 1375 * @param iq: iterator query state. 1376 * @param ie: iterator shared global environment. 1377 * @param id: module id. 1378 * @return true if the event needs more request processing immediately, 1379 * false if not. 1380 */ 1381 static int 1382 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq, 1383 struct iter_env* ie, int id) 1384 { 1385 uint8_t dpname_storage[LDNS_MAX_DOMAINLEN+1]; 1386 uint8_t* delname, *dpname=NULL; 1387 size_t delnamelen, dpnamelen=0; 1388 struct dns_msg* msg = NULL; 1389 1390 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo); 1391 /* check effort */ 1392 1393 /* We enforce a maximum number of query restarts. This is primarily a 1394 * cheap way to prevent CNAME loops. */ 1395 if(iq->query_restart_count > ie->max_query_restarts) { 1396 verbose(VERB_QUERY, "request has exceeded the maximum number" 1397 " of query restarts with %d", iq->query_restart_count); 1398 errinf(qstate, "request has exceeded the maximum number " 1399 "restarts (eg. indirections)"); 1400 if(iq->qchase.qname) 1401 errinf_dname(qstate, "stop at", iq->qchase.qname); 1402 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1403 } 1404 1405 /* We enforce a maximum recursion/dependency depth -- in general, 1406 * this is unnecessary for dependency loops (although it will 1407 * catch those), but it provides a sensible limit to the amount 1408 * of work required to answer a given query. */ 1409 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth); 1410 if(iq->depth > ie->max_dependency_depth) { 1411 verbose(VERB_QUERY, "request has exceeded the maximum " 1412 "dependency depth with depth of %d", iq->depth); 1413 errinf(qstate, "request has exceeded the maximum dependency " 1414 "depth (eg. nameserver lookup recursion)"); 1415 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1416 } 1417 1418 /* If the request is qclass=ANY, setup to generate each class */ 1419 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) { 1420 iq->qchase.qclass = 0; 1421 return next_state(iq, COLLECT_CLASS_STATE); 1422 } 1423 1424 /* 1425 * If we are restricted by a forward-zone or a stub-zone, we 1426 * can't re-fetch glue for this delegation point. 1427 * we won’t try to re-fetch glue if the iq->dp is null. 1428 */ 1429 if (iq->refetch_glue && 1430 iq->dp && 1431 !can_have_last_resort(qstate->env, iq->dp->name, 1432 iq->dp->namelen, iq->qchase.qclass, NULL, NULL, NULL)) { 1433 iq->refetch_glue = 0; 1434 } 1435 1436 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */ 1437 1438 /* This either results in a query restart (CNAME cache response), a 1439 * terminating response (ANSWER), or a cache miss (null). */ 1440 1441 /* Check RPZ for override */ 1442 if(qstate->env->auth_zones) { 1443 /* apply rpz qname triggers, like after cname */ 1444 struct dns_msg* forged_response = 1445 rpz_callback_from_iterator_cname(qstate, iq); 1446 if(forged_response) { 1447 uint8_t* sname = 0; 1448 size_t slen = 0; 1449 int count = 0; 1450 while(forged_response && reply_find_rrset_section_an( 1451 forged_response->rep, iq->qchase.qname, 1452 iq->qchase.qname_len, LDNS_RR_TYPE_CNAME, 1453 iq->qchase.qclass) && 1454 iq->qchase.qtype != LDNS_RR_TYPE_CNAME && 1455 count++ < ie->max_query_restarts) { 1456 /* another cname to follow */ 1457 if(!handle_cname_response(qstate, iq, forged_response, 1458 &sname, &slen)) { 1459 errinf(qstate, "malloc failure, CNAME info"); 1460 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1461 } 1462 iq->qchase.qname = sname; 1463 iq->qchase.qname_len = slen; 1464 forged_response = 1465 rpz_callback_from_iterator_cname(qstate, iq); 1466 } 1467 if(forged_response != NULL) { 1468 qstate->ext_state[id] = module_finished; 1469 qstate->return_rcode = LDNS_RCODE_NOERROR; 1470 qstate->return_msg = forged_response; 1471 iq->response = forged_response; 1472 next_state(iq, FINISHED_STATE); 1473 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) { 1474 log_err("rpz: after cached cname, prepend rrsets: out of memory"); 1475 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1476 } 1477 qstate->return_msg->qinfo = qstate->qinfo; 1478 return 0; 1479 } 1480 /* Follow the CNAME response */ 1481 iq->dp = NULL; 1482 iq->refetch_glue = 0; 1483 iq->query_restart_count++; 1484 iq->sent_count = 0; 1485 iq->dp_target_count = 0; 1486 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1487 if(qstate->env->cfg->qname_minimisation) 1488 iq->minimisation_state = INIT_MINIMISE_STATE; 1489 return next_state(iq, INIT_REQUEST_STATE); 1490 } 1491 } 1492 1493 if (iter_stub_fwd_no_cache(qstate, &iq->qchase, &dpname, &dpnamelen, 1494 dpname_storage, sizeof(dpname_storage))) { 1495 /* Asked to not query cache. */ 1496 verbose(VERB_ALGO, "no-cache set, going to the network"); 1497 qstate->no_cache_lookup = 1; 1498 qstate->no_cache_store = 1; 1499 msg = NULL; 1500 } else if(qstate->blacklist) { 1501 /* if cache, or anything else, was blacklisted then 1502 * getting older results from cache is a bad idea, no cache */ 1503 verbose(VERB_ALGO, "cache blacklisted, going to the network"); 1504 msg = NULL; 1505 } else if(!qstate->no_cache_lookup) { 1506 msg = dns_cache_lookup(qstate->env, iq->qchase.qname, 1507 iq->qchase.qname_len, iq->qchase.qtype, 1508 iq->qchase.qclass, qstate->query_flags, 1509 qstate->region, qstate->env->scratch, 0, dpname, 1510 dpnamelen); 1511 if(!msg && qstate->env->neg_cache && 1512 iter_qname_indicates_dnssec(qstate->env, &iq->qchase)) { 1513 /* lookup in negative cache; may result in 1514 * NOERROR/NODATA or NXDOMAIN answers that need validation */ 1515 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase, 1516 qstate->region, qstate->env->rrset_cache, 1517 qstate->env->scratch_buffer, 1518 *qstate->env->now, 1/*add SOA*/, NULL, 1519 qstate->env->cfg); 1520 } 1521 /* item taken from cache does not match our query name, thus 1522 * security needs to be re-examined later */ 1523 if(msg && query_dname_compare(qstate->qinfo.qname, 1524 iq->qchase.qname) != 0) 1525 msg->rep->security = sec_status_unchecked; 1526 } 1527 if(msg) { 1528 /* handle positive cache response */ 1529 enum response_type type = response_type_from_cache(msg, 1530 &iq->qchase); 1531 if(verbosity >= VERB_ALGO) { 1532 log_dns_msg("msg from cache lookup", &msg->qinfo, 1533 msg->rep); 1534 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d", 1535 (int)msg->rep->ttl, 1536 (int)msg->rep->prefetch_ttl); 1537 } 1538 1539 if(type == RESPONSE_TYPE_CNAME) { 1540 uint8_t* sname = 0; 1541 size_t slen = 0; 1542 verbose(VERB_ALGO, "returning CNAME response from " 1543 "cache"); 1544 if(!handle_cname_response(qstate, iq, msg, 1545 &sname, &slen)) { 1546 errinf(qstate, "failed to prepend CNAME " 1547 "components, malloc failure"); 1548 return error_response(qstate, id, 1549 LDNS_RCODE_SERVFAIL); 1550 } 1551 iq->qchase.qname = sname; 1552 iq->qchase.qname_len = slen; 1553 /* This *is* a query restart, even if it is a cheap 1554 * one. */ 1555 iq->dp = NULL; 1556 iq->refetch_glue = 0; 1557 iq->query_restart_count++; 1558 iq->sent_count = 0; 1559 iq->dp_target_count = 0; 1560 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1561 if(qstate->env->cfg->qname_minimisation) 1562 iq->minimisation_state = INIT_MINIMISE_STATE; 1563 return next_state(iq, INIT_REQUEST_STATE); 1564 } 1565 /* if from cache, NULL, else insert 'cache IP' len=0 */ 1566 if(qstate->reply_origin) 1567 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1568 if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_SERVFAIL) 1569 errinf(qstate, "SERVFAIL in cache"); 1570 /* it is an answer, response, to final state */ 1571 verbose(VERB_ALGO, "returning answer from cache."); 1572 iq->response = msg; 1573 return final_state(iq); 1574 } 1575 1576 /* attempt to forward the request */ 1577 if(forward_request(qstate, iq)) 1578 { 1579 if(!iq->dp) { 1580 log_err("alloc failure for forward dp"); 1581 errinf(qstate, "malloc failure for forward zone"); 1582 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1583 } 1584 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 1585 qstate->region, iq->dp, 0)) { 1586 errinf(qstate, "malloc failure, copy extra info into delegation point"); 1587 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1588 } 1589 if((qstate->query_flags&BIT_RD)==0) { 1590 /* If the server accepts RD=0 queries and forwards 1591 * with RD=1, then if the server is listed as an NS 1592 * entry, it starts query loops. Stop that loop by 1593 * disallowing the query. The RD=0 was previously used 1594 * to check the cache with allow_snoop. For stubs, 1595 * the iterator pass would have primed the stub and 1596 * then cached information can be used for further 1597 * queries. */ 1598 verbose(VERB_ALGO, "cannot forward RD=0 query, to stop query loops"); 1599 errinf(qstate, "cannot forward RD=0 query"); 1600 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1601 } 1602 iq->refetch_glue = 0; 1603 iq->minimisation_state = DONOT_MINIMISE_STATE; 1604 /* the request has been forwarded. 1605 * forwarded requests need to be immediately sent to the 1606 * next state, QUERYTARGETS. */ 1607 return next_state(iq, QUERYTARGETS_STATE); 1608 } 1609 1610 /* Resolver Algorithm Step 2 -- find the "best" servers. */ 1611 1612 /* first, adjust for DS queries. To avoid the grandparent problem, 1613 * we just look for the closest set of server to the parent of qname. 1614 * When re-fetching glue we also need to ask the parent. 1615 */ 1616 if(iq->refetch_glue) { 1617 if(!iq->dp) { 1618 log_err("internal or malloc fail: no dp for refetch"); 1619 errinf(qstate, "malloc failure, for delegation info"); 1620 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1621 } 1622 delname = iq->dp->name; 1623 delnamelen = iq->dp->namelen; 1624 } else { 1625 delname = iq->qchase.qname; 1626 delnamelen = iq->qchase.qname_len; 1627 } 1628 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue || 1629 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway 1630 && can_have_last_resort(qstate->env, delname, delnamelen, iq->qchase.qclass, NULL, NULL, NULL))) { 1631 /* remove first label from delname, root goes to hints, 1632 * but only to fetch glue, not for qtype=DS. */ 1633 /* also when prefetching an NS record, fetch it again from 1634 * its parent, just as if it expired, so that you do not 1635 * get stuck on an older nameserver that gives old NSrecords */ 1636 if(dname_is_root(delname) && (iq->refetch_glue || 1637 (iq->qchase.qtype == LDNS_RR_TYPE_NS && 1638 qstate->prefetch_leeway))) 1639 delname = NULL; /* go to root priming */ 1640 else dname_remove_label(&delname, &delnamelen); 1641 } 1642 /* delname is the name to lookup a delegation for. If NULL rootprime */ 1643 while(1) { 1644 1645 /* Lookup the delegation in the cache. If null, then the 1646 * cache needs to be primed for the qclass. */ 1647 if(delname) 1648 iq->dp = dns_cache_find_delegation(qstate->env, delname, 1649 delnamelen, iq->qchase.qtype, iq->qchase.qclass, 1650 qstate->region, &iq->deleg_msg, 1651 *qstate->env->now+qstate->prefetch_leeway, 1, 1652 dpname, dpnamelen); 1653 else iq->dp = NULL; 1654 1655 /* If the cache has returned nothing, then we have a 1656 * root priming situation. */ 1657 if(iq->dp == NULL) { 1658 int r; 1659 int nolock = 0; 1660 /* if under auth zone, no prime needed */ 1661 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen)) 1662 return error_response(qstate, id, 1663 LDNS_RCODE_SERVFAIL); 1664 if(iq->dp) /* use auth zone dp */ 1665 return next_state(iq, INIT_REQUEST_2_STATE); 1666 /* if there is a stub, then no root prime needed */ 1667 r = prime_stub(qstate, iq, id, delname, 1668 iq->qchase.qclass); 1669 if(r == 2) 1670 break; /* got noprime-stub-zone, continue */ 1671 else if(r) 1672 return 0; /* stub prime request made */ 1673 if(forwards_lookup_root(qstate->env->fwds, 1674 iq->qchase.qclass, nolock)) { 1675 lock_rw_unlock(&qstate->env->fwds->lock); 1676 /* forward zone root, no root prime needed */ 1677 /* fill in some dp - safety belt */ 1678 iq->dp = hints_find_root(qstate->env->hints, 1679 iq->qchase.qclass, nolock); 1680 if(!iq->dp) { 1681 log_err("internal error: no hints dp"); 1682 errinf(qstate, "no hints for this class"); 1683 return error_response_cache(qstate, id, 1684 LDNS_RCODE_SERVFAIL); 1685 } 1686 iq->dp = delegpt_copy(iq->dp, qstate->region); 1687 lock_rw_unlock(&qstate->env->hints->lock); 1688 if(!iq->dp) { 1689 log_err("out of memory in safety belt"); 1690 errinf(qstate, "malloc failure, in safety belt"); 1691 return error_response(qstate, id, 1692 LDNS_RCODE_SERVFAIL); 1693 } 1694 return next_state(iq, INIT_REQUEST_2_STATE); 1695 } 1696 /* Note that the result of this will set a new 1697 * DelegationPoint based on the result of priming. */ 1698 if(!prime_root(qstate, iq, id, iq->qchase.qclass)) 1699 return error_response(qstate, id, 1700 LDNS_RCODE_REFUSED); 1701 1702 /* priming creates and sends a subordinate query, with 1703 * this query as the parent. So further processing for 1704 * this event will stop until reactivated by the 1705 * results of priming. */ 1706 return 0; 1707 } 1708 if(!iq->ratelimit_ok && qstate->prefetch_leeway) 1709 iq->ratelimit_ok = 1; /* allow prefetches, this keeps 1710 otherwise valid data in the cache */ 1711 1712 /* see if this dp not useless. 1713 * It is useless if: 1714 * o all NS items are required glue. 1715 * or the query is for NS item that is required glue. 1716 * o no addresses are provided. 1717 * o RD qflag is on. 1718 * Instead, go up one level, and try to get even further 1719 * If the root was useless, use safety belt information. 1720 * Only check cache returns, because replies for servers 1721 * could be useless but lead to loops (bumping into the 1722 * same server reply) if useless-checked. 1723 */ 1724 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, 1725 iq->dp, ie->supports_ipv4, ie->supports_ipv6, 1726 ie->use_nat64)) { 1727 int have_dp = 0; 1728 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, iq->qchase.qclass, &have_dp, &iq->dp, qstate->region)) { 1729 if(have_dp) { 1730 verbose(VERB_QUERY, "cache has stub " 1731 "or fwd but no addresses, " 1732 "fallback to config"); 1733 if(have_dp && !iq->dp) { 1734 log_err("out of memory in " 1735 "stub/fwd fallback"); 1736 errinf(qstate, "malloc failure, for fallback to config"); 1737 return error_response(qstate, 1738 id, LDNS_RCODE_SERVFAIL); 1739 } 1740 break; 1741 } 1742 verbose(VERB_ALGO, "useless dp " 1743 "but cannot go up, servfail"); 1744 delegpt_log(VERB_ALGO, iq->dp); 1745 errinf(qstate, "no useful nameservers, " 1746 "and cannot go up"); 1747 errinf_dname(qstate, "for zone", iq->dp->name); 1748 return error_response(qstate, id, 1749 LDNS_RCODE_SERVFAIL); 1750 } 1751 if(dname_is_root(iq->dp->name)) { 1752 /* use safety belt */ 1753 int nolock = 0; 1754 verbose(VERB_QUERY, "Cache has root NS but " 1755 "no addresses. Fallback to the safety belt."); 1756 iq->dp = hints_find_root(qstate->env->hints, 1757 iq->qchase.qclass, nolock); 1758 /* note deleg_msg is from previous lookup, 1759 * but RD is on, so it is not used */ 1760 if(!iq->dp) { 1761 log_err("internal error: no hints dp"); 1762 return error_response(qstate, id, 1763 LDNS_RCODE_REFUSED); 1764 } 1765 iq->dp = delegpt_copy(iq->dp, qstate->region); 1766 lock_rw_unlock(&qstate->env->hints->lock); 1767 if(!iq->dp) { 1768 log_err("out of memory in safety belt"); 1769 errinf(qstate, "malloc failure, in safety belt, for root"); 1770 return error_response(qstate, id, 1771 LDNS_RCODE_SERVFAIL); 1772 } 1773 break; 1774 } else { 1775 verbose(VERB_ALGO, 1776 "cache delegation was useless:"); 1777 delegpt_log(VERB_ALGO, iq->dp); 1778 /* go up */ 1779 delname = iq->dp->name; 1780 delnamelen = iq->dp->namelen; 1781 dname_remove_label(&delname, &delnamelen); 1782 } 1783 } else break; 1784 } 1785 1786 verbose(VERB_ALGO, "cache delegation returns delegpt"); 1787 delegpt_log(VERB_ALGO, iq->dp); 1788 1789 /* Otherwise, set the current delegation point and move on to the 1790 * next state. */ 1791 return next_state(iq, INIT_REQUEST_2_STATE); 1792 } 1793 1794 /** 1795 * Process the second part of the initial request handling. This state 1796 * basically exists so that queries that generate root priming events have 1797 * the same init processing as ones that do not. Request events that reach 1798 * this state must have a valid currentDelegationPoint set. 1799 * 1800 * This part is primarily handling stub zone priming. Events that reach this 1801 * state must have a current delegation point. 1802 * 1803 * @param qstate: query state. 1804 * @param iq: iterator query state. 1805 * @param id: module id. 1806 * @return true if the event needs more request processing immediately, 1807 * false if not. 1808 */ 1809 static int 1810 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq, 1811 int id) 1812 { 1813 uint8_t* delname; 1814 size_t delnamelen; 1815 log_query_info(VERB_QUERY, "resolving (init part 2): ", 1816 &qstate->qinfo); 1817 1818 delname = iq->qchase.qname; 1819 delnamelen = iq->qchase.qname_len; 1820 if(iq->refetch_glue) { 1821 struct iter_hints_stub* stub; 1822 int nolock = 0; 1823 if(!iq->dp) { 1824 log_err("internal or malloc fail: no dp for refetch"); 1825 errinf(qstate, "malloc failure, no delegation info"); 1826 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1827 } 1828 /* Do not send queries above stub, do not set delname to dp if 1829 * this is above stub without stub-first. */ 1830 stub = hints_lookup_stub( 1831 qstate->env->hints, iq->qchase.qname, iq->qchase.qclass, 1832 iq->dp, nolock); 1833 if(!stub || !stub->dp->has_parent_side_NS || 1834 dname_subdomain_c(iq->dp->name, stub->dp->name)) { 1835 delname = iq->dp->name; 1836 delnamelen = iq->dp->namelen; 1837 } 1838 /* lock_() calls are macros that could be nothing, surround in {} */ 1839 if(stub) { lock_rw_unlock(&qstate->env->hints->lock); } 1840 } 1841 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) { 1842 if(!dname_is_root(delname)) 1843 dname_remove_label(&delname, &delnamelen); 1844 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */ 1845 } 1846 1847 /* see if we have an auth zone to answer from, improves dp from cache 1848 * (if any dp from cache) with auth zone dp, if that is lower */ 1849 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen)) 1850 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1851 1852 /* Check to see if we need to prime a stub zone. */ 1853 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) { 1854 /* A priming sub request was made */ 1855 return 0; 1856 } 1857 1858 /* most events just get forwarded to the next state. */ 1859 return next_state(iq, INIT_REQUEST_3_STATE); 1860 } 1861 1862 /** 1863 * Process the third part of the initial request handling. This state exists 1864 * as a separate state so that queries that generate stub priming events 1865 * will get the tail end of the init process but not repeat the stub priming 1866 * check. 1867 * 1868 * @param qstate: query state. 1869 * @param iq: iterator query state. 1870 * @param id: module id. 1871 * @return true, advancing the event to the QUERYTARGETS_STATE. 1872 */ 1873 static int 1874 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq, 1875 int id) 1876 { 1877 log_query_info(VERB_QUERY, "resolving (init part 3): ", 1878 &qstate->qinfo); 1879 /* if the cache reply dp equals a validation anchor or msg has DS, 1880 * then DNSSEC RRSIGs are expected in the reply */ 1881 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp, 1882 iq->deleg_msg, iq->qchase.qclass); 1883 1884 /* If the RD flag wasn't set, then we just finish with the 1885 * cached referral as the response. */ 1886 if(!(qstate->query_flags & BIT_RD) && iq->deleg_msg) { 1887 iq->response = iq->deleg_msg; 1888 if(verbosity >= VERB_ALGO && iq->response) 1889 log_dns_msg("no RD requested, using delegation msg", 1890 &iq->response->qinfo, iq->response->rep); 1891 if(qstate->reply_origin) 1892 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1893 return final_state(iq); 1894 } 1895 /* After this point, unset the RD flag -- this query is going to 1896 * be sent to an auth. server. */ 1897 iq->chase_flags &= ~BIT_RD; 1898 1899 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */ 1900 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 1901 !(qstate->query_flags&BIT_CD)) { 1902 generate_dnskey_prefetch(qstate, iq, id); 1903 fptr_ok(fptr_whitelist_modenv_detach_subs( 1904 qstate->env->detach_subs)); 1905 (*qstate->env->detach_subs)(qstate); 1906 } 1907 1908 /* Jump to the next state. */ 1909 return next_state(iq, QUERYTARGETS_STATE); 1910 } 1911 1912 /** 1913 * Given a basic query, generate a parent-side "target" query. 1914 * These are subordinate queries for missing delegation point target addresses, 1915 * for which only the parent of the delegation provides correct IP addresses. 1916 * 1917 * @param qstate: query state. 1918 * @param iq: iterator query state. 1919 * @param id: module id. 1920 * @param name: target qname. 1921 * @param namelen: target qname length. 1922 * @param qtype: target qtype (either A or AAAA). 1923 * @param qclass: target qclass. 1924 * @return true on success, false on failure. 1925 */ 1926 static int 1927 generate_parentside_target_query(struct module_qstate* qstate, 1928 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen, 1929 uint16_t qtype, uint16_t qclass) 1930 { 1931 struct module_qstate* subq; 1932 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1933 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) 1934 return 0; 1935 if(subq) { 1936 struct iter_qstate* subiq = 1937 (struct iter_qstate*)subq->minfo[id]; 1938 /* blacklist the cache - we want to fetch parent stuff */ 1939 sock_list_insert(&subq->blacklist, NULL, 0, subq->region); 1940 subiq->query_for_pside_glue = 1; 1941 if(dname_subdomain_c(name, iq->dp->name)) { 1942 subiq->dp = delegpt_copy(iq->dp, subq->region); 1943 subiq->dnssec_expected = iter_indicates_dnssec( 1944 qstate->env, subiq->dp, NULL, 1945 subq->qinfo.qclass); 1946 subiq->refetch_glue = 1; 1947 } else { 1948 subiq->dp = dns_cache_find_delegation(qstate->env, 1949 name, namelen, qtype, qclass, subq->region, 1950 &subiq->deleg_msg, 1951 *qstate->env->now+subq->prefetch_leeway, 1952 1, NULL, 0); 1953 /* if no dp, then it's from root, refetch unneeded */ 1954 if(subiq->dp) { 1955 subiq->dnssec_expected = iter_indicates_dnssec( 1956 qstate->env, subiq->dp, NULL, 1957 subq->qinfo.qclass); 1958 subiq->refetch_glue = 1; 1959 } 1960 } 1961 } 1962 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass); 1963 return 1; 1964 } 1965 1966 /** 1967 * Given a basic query, generate a "target" query. These are subordinate 1968 * queries for missing delegation point target addresses. 1969 * 1970 * @param qstate: query state. 1971 * @param iq: iterator query state. 1972 * @param id: module id. 1973 * @param name: target qname. 1974 * @param namelen: target qname length. 1975 * @param qtype: target qtype (either A or AAAA). 1976 * @param qclass: target qclass. 1977 * @return true on success, false on failure. 1978 */ 1979 static int 1980 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq, 1981 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass) 1982 { 1983 struct module_qstate* subq; 1984 if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1985 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) 1986 return 0; 1987 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass); 1988 return 1; 1989 } 1990 1991 /** 1992 * Given an event at a certain state, generate zero or more target queries 1993 * for it's current delegation point. 1994 * 1995 * @param qstate: query state. 1996 * @param iq: iterator query state. 1997 * @param ie: iterator shared global environment. 1998 * @param id: module id. 1999 * @param maxtargets: The maximum number of targets to query for. 2000 * if it is negative, there is no maximum number of targets. 2001 * @param num: returns the number of queries generated and processed, 2002 * which may be zero if there were no missing targets. 2003 * @return 0 on success, nonzero on error. 1 means temporary failure and 2004 * 2 means the failure can be cached. 2005 */ 2006 static int 2007 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq, 2008 struct iter_env* ie, int id, int maxtargets, int* num) 2009 { 2010 int query_count = 0; 2011 struct delegpt_ns* ns; 2012 int missing; 2013 int toget = 0; 2014 2015 iter_mark_cycle_targets(qstate, iq->dp); 2016 missing = (int)delegpt_count_missing_targets(iq->dp, NULL); 2017 log_assert(maxtargets != 0); /* that would not be useful */ 2018 2019 /* Generate target requests. Basically, any missing targets 2020 * are queried for here, regardless if it is necessary to do 2021 * so to continue processing. */ 2022 if(maxtargets < 0 || maxtargets > missing) 2023 toget = missing; 2024 else toget = maxtargets; 2025 if(toget == 0) { 2026 *num = 0; 2027 return 0; 2028 } 2029 2030 /* now that we are sure that a target query is going to be made, 2031 * check the limits. */ 2032 if(iq->depth == ie->max_dependency_depth) 2033 return 1; 2034 if(iq->depth > 0 && iq->target_count && 2035 iq->target_count[TARGET_COUNT_QUERIES] > MAX_TARGET_COUNT) { 2036 char s[LDNS_MAX_DOMAINLEN+1]; 2037 dname_str(qstate->qinfo.qname, s); 2038 verbose(VERB_QUERY, "request %s has exceeded the maximum " 2039 "number of glue fetches %d", s, 2040 iq->target_count[TARGET_COUNT_QUERIES]); 2041 return 2; 2042 } 2043 if(iq->dp_target_count > MAX_DP_TARGET_COUNT) { 2044 char s[LDNS_MAX_DOMAINLEN+1]; 2045 dname_str(qstate->qinfo.qname, s); 2046 verbose(VERB_QUERY, "request %s has exceeded the maximum " 2047 "number of glue fetches %d to a single delegation point", 2048 s, iq->dp_target_count); 2049 return 2; 2050 } 2051 2052 /* select 'toget' items from the total of 'missing' items */ 2053 log_assert(toget <= missing); 2054 2055 /* loop over missing targets */ 2056 for(ns = iq->dp->nslist; ns; ns = ns->next) { 2057 if(ns->resolved) 2058 continue; 2059 2060 /* randomly select this item with probability toget/missing */ 2061 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) { 2062 /* do not select this one, next; select toget number 2063 * of items from a list one less in size */ 2064 missing --; 2065 continue; 2066 } 2067 2068 if(ie->supports_ipv6 && 2069 ((ns->lame && !ns->done_pside6) || 2070 (!ns->lame && !ns->got6))) { 2071 /* Send the AAAA request. */ 2072 if(!generate_target_query(qstate, iq, id, 2073 ns->name, ns->namelen, 2074 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { 2075 *num = query_count; 2076 if(query_count > 0) 2077 qstate->ext_state[id] = module_wait_subquery; 2078 return 1; 2079 } 2080 query_count++; 2081 /* If the mesh query list is full, exit the loop here. 2082 * This makes the routine spawn one query at a time, 2083 * and this means there is no query state load 2084 * increase, because the spawned state uses cpu and a 2085 * socket while this state waits for that spawned 2086 * state. Next time we can look up further targets */ 2087 if(mesh_jostle_exceeded(qstate->env->mesh)) { 2088 /* If no ip4 query is possible, that makes 2089 * this ns resolved. */ 2090 if(!((ie->supports_ipv4 || ie->use_nat64) && 2091 ((ns->lame && !ns->done_pside4) || 2092 (!ns->lame && !ns->got4)))) { 2093 ns->resolved = 1; 2094 } 2095 break; 2096 } 2097 } 2098 /* Send the A request. */ 2099 if((ie->supports_ipv4 || ie->use_nat64) && 2100 ((ns->lame && !ns->done_pside4) || 2101 (!ns->lame && !ns->got4))) { 2102 if(!generate_target_query(qstate, iq, id, 2103 ns->name, ns->namelen, 2104 LDNS_RR_TYPE_A, iq->qchase.qclass)) { 2105 *num = query_count; 2106 if(query_count > 0) 2107 qstate->ext_state[id] = module_wait_subquery; 2108 return 1; 2109 } 2110 query_count++; 2111 /* If the mesh query list is full, exit the loop. */ 2112 if(mesh_jostle_exceeded(qstate->env->mesh)) { 2113 /* With the ip6 query already checked for, 2114 * this makes the ns resolved. It is no longer 2115 * a missing target. */ 2116 ns->resolved = 1; 2117 break; 2118 } 2119 } 2120 2121 /* mark this target as in progress. */ 2122 ns->resolved = 1; 2123 missing--; 2124 toget--; 2125 if(toget == 0) 2126 break; 2127 } 2128 *num = query_count; 2129 if(query_count > 0) 2130 qstate->ext_state[id] = module_wait_subquery; 2131 2132 return 0; 2133 } 2134 2135 /** 2136 * Called by processQueryTargets when it would like extra targets to query 2137 * but it seems to be out of options. At last resort some less appealing 2138 * options are explored. If there are no more options, the result is SERVFAIL 2139 * 2140 * @param qstate: query state. 2141 * @param iq: iterator query state. 2142 * @param ie: iterator shared global environment. 2143 * @param id: module id. 2144 * @return true if the event requires more request processing immediately, 2145 * false if not. 2146 */ 2147 static int 2148 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq, 2149 struct iter_env* ie, int id) 2150 { 2151 struct delegpt_ns* ns; 2152 int query_count = 0; 2153 verbose(VERB_ALGO, "No more query targets, attempting last resort"); 2154 log_assert(iq->dp); 2155 2156 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, 2157 iq->qchase.qclass, NULL, NULL, NULL)) { 2158 /* fail -- no more targets, no more hope of targets, no hope 2159 * of a response. */ 2160 errinf(qstate, "all the configured stub or forward servers failed,"); 2161 errinf_dname(qstate, "at zone", iq->dp->name); 2162 errinf_reply(qstate, iq); 2163 verbose(VERB_QUERY, "configured stub or forward servers failed -- returning SERVFAIL"); 2164 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2165 } 2166 if(qstate->env->cfg->harden_unverified_glue) { 2167 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 2168 qstate->region, iq->dp, PACKED_RRSET_UNVERIFIED_GLUE)) 2169 log_err("out of memory in cache_fill_missing"); 2170 if(iq->dp->usable_list) { 2171 verbose(VERB_ALGO, "try unverified glue from cache"); 2172 return next_state(iq, QUERYTARGETS_STATE); 2173 } 2174 } 2175 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) { 2176 struct delegpt* dp; 2177 int nolock = 0; 2178 dp = hints_find_root(qstate->env->hints, 2179 iq->qchase.qclass, nolock); 2180 if(dp) { 2181 struct delegpt_addr* a; 2182 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 2183 for(ns = dp->nslist; ns; ns=ns->next) { 2184 (void)delegpt_add_ns(iq->dp, qstate->region, 2185 ns->name, ns->lame, ns->tls_auth_name, 2186 ns->port); 2187 } 2188 for(a = dp->target_list; a; a=a->next_target) { 2189 (void)delegpt_add_addr(iq->dp, qstate->region, 2190 &a->addr, a->addrlen, a->bogus, 2191 a->lame, a->tls_auth_name, -1, NULL); 2192 } 2193 lock_rw_unlock(&qstate->env->hints->lock); 2194 } 2195 iq->dp->has_parent_side_NS = 1; 2196 } else if(!iq->dp->has_parent_side_NS) { 2197 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp, 2198 qstate->region, &qstate->qinfo) 2199 || !iq->dp->has_parent_side_NS) { 2200 /* if: malloc failure in lookup go up to try */ 2201 /* if: no parent NS in cache - go up one level */ 2202 verbose(VERB_ALGO, "try to grab parent NS"); 2203 iq->store_parent_NS = iq->dp; 2204 iq->chase_flags &= ~BIT_RD; /* go to authorities */ 2205 iq->deleg_msg = NULL; 2206 iq->refetch_glue = 1; 2207 iq->query_restart_count++; 2208 iq->sent_count = 0; 2209 iq->dp_target_count = 0; 2210 if(qstate->env->cfg->qname_minimisation) 2211 iq->minimisation_state = INIT_MINIMISE_STATE; 2212 return next_state(iq, INIT_REQUEST_STATE); 2213 } 2214 } 2215 /* see if that makes new names available */ 2216 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 2217 qstate->region, iq->dp, 0)) 2218 log_err("out of memory in cache_fill_missing"); 2219 if(iq->dp->usable_list) { 2220 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache"); 2221 return next_state(iq, QUERYTARGETS_STATE); 2222 } 2223 /* try to fill out parent glue from cache */ 2224 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp, 2225 qstate->region, &qstate->qinfo)) { 2226 /* got parent stuff from cache, see if we can continue */ 2227 verbose(VERB_ALGO, "try parent-side glue from cache"); 2228 return next_state(iq, QUERYTARGETS_STATE); 2229 } 2230 /* query for an extra name added by the parent-NS record */ 2231 if(delegpt_count_missing_targets(iq->dp, NULL) > 0) { 2232 int qs = 0, ret; 2233 verbose(VERB_ALGO, "try parent-side target name"); 2234 if((ret=query_for_targets(qstate, iq, ie, id, 1, &qs))!=0) { 2235 errinf(qstate, "could not fetch nameserver"); 2236 errinf_dname(qstate, "at zone", iq->dp->name); 2237 if(ret == 1) 2238 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2239 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2240 } 2241 iq->num_target_queries += qs; 2242 target_count_increase(iq, qs); 2243 if(qs != 0) { 2244 qstate->ext_state[id] = module_wait_subquery; 2245 return 0; /* and wait for them */ 2246 } 2247 } 2248 if(iq->depth == ie->max_dependency_depth) { 2249 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail"); 2250 errinf(qstate, "cannot fetch more nameservers because at max dependency depth"); 2251 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2252 } 2253 if(iq->depth > 0 && iq->target_count && 2254 iq->target_count[TARGET_COUNT_QUERIES] > MAX_TARGET_COUNT) { 2255 char s[LDNS_MAX_DOMAINLEN+1]; 2256 dname_str(qstate->qinfo.qname, s); 2257 verbose(VERB_QUERY, "request %s has exceeded the maximum " 2258 "number of glue fetches %d", s, 2259 iq->target_count[TARGET_COUNT_QUERIES]); 2260 errinf(qstate, "exceeded the maximum number of glue fetches"); 2261 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2262 } 2263 /* mark cycle targets for parent-side lookups */ 2264 iter_mark_pside_cycle_targets(qstate, iq->dp); 2265 /* see if we can issue queries to get nameserver addresses */ 2266 /* this lookup is not randomized, but sequential. */ 2267 for(ns = iq->dp->nslist; ns; ns = ns->next) { 2268 /* if this nameserver is at a delegation point, but that 2269 * delegation point is a stub and we cannot go higher, skip*/ 2270 if( ((ie->supports_ipv6 && !ns->done_pside6) || 2271 ((ie->supports_ipv4 || ie->use_nat64) && !ns->done_pside4)) && 2272 !can_have_last_resort(qstate->env, ns->name, ns->namelen, 2273 iq->qchase.qclass, NULL, NULL, NULL)) { 2274 log_nametypeclass(VERB_ALGO, "cannot pside lookup ns " 2275 "because it is also a stub/forward,", 2276 ns->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 2277 if(ie->supports_ipv6) ns->done_pside6 = 1; 2278 if(ie->supports_ipv4 || ie->use_nat64) ns->done_pside4 = 1; 2279 continue; 2280 } 2281 /* query for parent-side A and AAAA for nameservers */ 2282 if(ie->supports_ipv6 && !ns->done_pside6) { 2283 /* Send the AAAA request. */ 2284 if(!generate_parentside_target_query(qstate, iq, id, 2285 ns->name, ns->namelen, 2286 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { 2287 errinf_dname(qstate, "could not generate nameserver AAAA lookup for", ns->name); 2288 return error_response(qstate, id, 2289 LDNS_RCODE_SERVFAIL); 2290 } 2291 ns->done_pside6 = 1; 2292 query_count++; 2293 if(mesh_jostle_exceeded(qstate->env->mesh)) { 2294 /* Wait for the lookup; do not spawn multiple 2295 * lookups at a time. */ 2296 verbose(VERB_ALGO, "try parent-side glue lookup"); 2297 iq->num_target_queries += query_count; 2298 target_count_increase(iq, query_count); 2299 qstate->ext_state[id] = module_wait_subquery; 2300 return 0; 2301 } 2302 } 2303 if((ie->supports_ipv4 || ie->use_nat64) && !ns->done_pside4) { 2304 /* Send the A request. */ 2305 if(!generate_parentside_target_query(qstate, iq, id, 2306 ns->name, ns->namelen, 2307 LDNS_RR_TYPE_A, iq->qchase.qclass)) { 2308 errinf_dname(qstate, "could not generate nameserver A lookup for", ns->name); 2309 return error_response(qstate, id, 2310 LDNS_RCODE_SERVFAIL); 2311 } 2312 ns->done_pside4 = 1; 2313 query_count++; 2314 } 2315 if(query_count != 0) { /* suspend to await results */ 2316 verbose(VERB_ALGO, "try parent-side glue lookup"); 2317 iq->num_target_queries += query_count; 2318 target_count_increase(iq, query_count); 2319 qstate->ext_state[id] = module_wait_subquery; 2320 return 0; 2321 } 2322 } 2323 2324 /* if this was a parent-side glue query itself, then store that 2325 * failure in cache. */ 2326 if(!qstate->no_cache_store && iq->query_for_pside_glue 2327 && !iq->pside_glue) 2328 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 2329 iq->deleg_msg?iq->deleg_msg->rep: 2330 (iq->response?iq->response->rep:NULL)); 2331 2332 errinf(qstate, "all servers for this domain failed,"); 2333 errinf_dname(qstate, "at zone", iq->dp->name); 2334 errinf_reply(qstate, iq); 2335 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL"); 2336 /* fail -- no more targets, no more hope of targets, no hope 2337 * of a response. */ 2338 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2339 } 2340 2341 /** 2342 * Try to find the NS record set that will resolve a qtype DS query. Due 2343 * to grandparent/grandchild reasons we did not get a proper lookup right 2344 * away. We need to create type NS queries until we get the right parent 2345 * for this lookup. We remove labels from the query to find the right point. 2346 * If we end up at the old dp name, then there is no solution. 2347 * 2348 * @param qstate: query state. 2349 * @param iq: iterator query state. 2350 * @param id: module id. 2351 * @return true if the event requires more immediate processing, false if 2352 * not. This is generally only true when forwarding the request to 2353 * the final state (i.e., on answer). 2354 */ 2355 static int 2356 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id) 2357 { 2358 struct module_qstate* subq = NULL; 2359 verbose(VERB_ALGO, "processDSNSFind"); 2360 2361 if(!iq->dsns_point) { 2362 /* initialize */ 2363 iq->dsns_point = iq->qchase.qname; 2364 iq->dsns_point_len = iq->qchase.qname_len; 2365 } 2366 /* robustcheck for internal error: we are not underneath the dp */ 2367 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) { 2368 errinf_dname(qstate, "for DS query parent-child nameserver search the query is not under the zone", iq->dp->name); 2369 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2370 } 2371 2372 /* go up one (more) step, until we hit the dp, if so, end */ 2373 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len); 2374 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) { 2375 /* there was no inbetween nameserver, use the old delegation 2376 * point again. And this time, because dsns_point is nonNULL 2377 * we are going to accept the (bad) result */ 2378 iq->state = QUERYTARGETS_STATE; 2379 return 1; 2380 } 2381 iq->state = DSNS_FIND_STATE; 2382 2383 /* spawn NS lookup (validation not needed, this is for DS lookup) */ 2384 log_nametypeclass(VERB_ALGO, "fetch nameservers", 2385 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass); 2386 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len, 2387 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 2388 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) { 2389 errinf_dname(qstate, "for DS query parent-child nameserver search, could not generate NS lookup for", iq->dsns_point); 2390 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2391 } 2392 2393 return 0; 2394 } 2395 2396 /** 2397 * Check if we wait responses for sent queries and update the iterator's 2398 * external state. 2399 */ 2400 static void 2401 check_waiting_queries(struct iter_qstate* iq, struct module_qstate* qstate, 2402 int id) 2403 { 2404 if(iq->num_target_queries>0 && iq->num_current_queries>0) { 2405 verbose(VERB_ALGO, "waiting for %d targets to " 2406 "resolve or %d outstanding queries to " 2407 "respond", iq->num_target_queries, 2408 iq->num_current_queries); 2409 qstate->ext_state[id] = module_wait_reply; 2410 } else if(iq->num_target_queries>0) { 2411 verbose(VERB_ALGO, "waiting for %d targets to " 2412 "resolve", iq->num_target_queries); 2413 qstate->ext_state[id] = module_wait_subquery; 2414 } else { 2415 verbose(VERB_ALGO, "waiting for %d " 2416 "outstanding queries to respond", 2417 iq->num_current_queries); 2418 qstate->ext_state[id] = module_wait_reply; 2419 } 2420 } 2421 2422 /** 2423 * This is the request event state where the request will be sent to one of 2424 * its current query targets. This state also handles issuing target lookup 2425 * queries for missing target IP addresses. Queries typically iterate on 2426 * this state, both when they are just trying different targets for a given 2427 * delegation point, and when they change delegation points. This state 2428 * roughly corresponds to RFC 1034 algorithm steps 3 and 4. 2429 * 2430 * @param qstate: query state. 2431 * @param iq: iterator query state. 2432 * @param ie: iterator shared global environment. 2433 * @param id: module id. 2434 * @return true if the event requires more request processing immediately, 2435 * false if not. This state only returns true when it is generating 2436 * a SERVFAIL response because the query has hit a dead end. 2437 */ 2438 static int 2439 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq, 2440 struct iter_env* ie, int id) 2441 { 2442 int tf_policy; 2443 struct delegpt_addr* target; 2444 struct outbound_entry* outq; 2445 struct sockaddr_storage real_addr; 2446 socklen_t real_addrlen; 2447 int auth_fallback = 0; 2448 uint8_t* qout_orig = NULL; 2449 size_t qout_orig_len = 0; 2450 int sq_check_ratelimit = 1; 2451 int sq_was_ratelimited = 0; 2452 int can_do_promisc = 0; 2453 2454 /* NOTE: a request will encounter this state for each target it 2455 * needs to send a query to. That is, at least one per referral, 2456 * more if some targets timeout or return throwaway answers. */ 2457 2458 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo); 2459 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, " 2460 "currentqueries %d sentcount %d", iq->num_target_queries, 2461 iq->num_current_queries, iq->sent_count); 2462 2463 /* Make sure that we haven't run away */ 2464 if(iq->referral_count > MAX_REFERRAL_COUNT) { 2465 verbose(VERB_QUERY, "request has exceeded the maximum " 2466 "number of referrrals with %d", iq->referral_count); 2467 errinf(qstate, "exceeded the maximum of referrals"); 2468 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2469 } 2470 if(iq->sent_count > ie->max_sent_count) { 2471 verbose(VERB_QUERY, "request has exceeded the maximum " 2472 "number of sends with %d", iq->sent_count); 2473 errinf(qstate, "exceeded the maximum number of sends"); 2474 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2475 } 2476 2477 /* Check if we reached MAX_TARGET_NX limit without a fallback activation. */ 2478 if(iq->target_count && !*iq->nxns_dp && 2479 iq->target_count[TARGET_COUNT_NX] > MAX_TARGET_NX) { 2480 struct delegpt_ns* ns; 2481 /* If we can wait for resolution, do so. */ 2482 if(iq->num_target_queries>0 || iq->num_current_queries>0) { 2483 check_waiting_queries(iq, qstate, id); 2484 return 0; 2485 } 2486 verbose(VERB_ALGO, "request has exceeded the maximum " 2487 "number of nxdomain nameserver lookups (%d) with %d", 2488 MAX_TARGET_NX, iq->target_count[TARGET_COUNT_NX]); 2489 /* Check for dp because we require one below */ 2490 if(!iq->dp) { 2491 verbose(VERB_QUERY, "Failed to get a delegation, " 2492 "giving up"); 2493 errinf(qstate, "failed to get a delegation (eg. prime " 2494 "failure)"); 2495 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2496 } 2497 /* We reached the limit but we already have parent side 2498 * information; stop resolution */ 2499 if(iq->dp->has_parent_side_NS) { 2500 verbose(VERB_ALGO, "parent-side information is " 2501 "already present for the delegation point, no " 2502 "fallback possible"); 2503 errinf(qstate, "exceeded the maximum nameserver nxdomains"); 2504 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2505 } 2506 verbose(VERB_ALGO, "initiating parent-side fallback for " 2507 "nxdomain nameserver lookups"); 2508 /* Mark all the current NSes as resolved to allow for parent 2509 * fallback */ 2510 for(ns=iq->dp->nslist; ns; ns=ns->next) { 2511 ns->resolved = 1; 2512 } 2513 /* Note the delegation point that triggered the NXNS fallback; 2514 * no reason for shared queries to keep trying there. 2515 * This also marks the fallback activation. */ 2516 *iq->nxns_dp = malloc(iq->dp->namelen); 2517 if(!*iq->nxns_dp) { 2518 verbose(VERB_ALGO, "out of memory while initiating " 2519 "fallback"); 2520 errinf(qstate, "exceeded the maximum nameserver " 2521 "nxdomains (malloc)"); 2522 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2523 } 2524 memcpy(*iq->nxns_dp, iq->dp->name, iq->dp->namelen); 2525 } else if(iq->target_count && *iq->nxns_dp) { 2526 /* Handle the NXNS fallback case. */ 2527 /* If we can wait for resolution, do so. */ 2528 if(iq->num_target_queries>0 || iq->num_current_queries>0) { 2529 check_waiting_queries(iq, qstate, id); 2530 return 0; 2531 } 2532 /* Check for dp because we require one below */ 2533 if(!iq->dp) { 2534 verbose(VERB_QUERY, "Failed to get a delegation, " 2535 "giving up"); 2536 errinf(qstate, "failed to get a delegation (eg. prime " 2537 "failure)"); 2538 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2539 } 2540 2541 if(iq->target_count[TARGET_COUNT_NX] > MAX_TARGET_NX_FALLBACK) { 2542 verbose(VERB_ALGO, "request has exceeded the maximum " 2543 "number of fallback nxdomain nameserver " 2544 "lookups (%d) with %d", MAX_TARGET_NX_FALLBACK, 2545 iq->target_count[TARGET_COUNT_NX]); 2546 errinf(qstate, "exceeded the maximum nameserver nxdomains"); 2547 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2548 } 2549 2550 if(!iq->dp->has_parent_side_NS) { 2551 struct delegpt_ns* ns; 2552 if(!dname_canonical_compare(*iq->nxns_dp, iq->dp->name)) { 2553 verbose(VERB_ALGO, "this delegation point " 2554 "initiated the fallback, marking the " 2555 "nslist as resolved"); 2556 for(ns=iq->dp->nslist; ns; ns=ns->next) { 2557 ns->resolved = 1; 2558 } 2559 } 2560 } 2561 } 2562 2563 /* Make sure we have a delegation point, otherwise priming failed 2564 * or another failure occurred */ 2565 if(!iq->dp) { 2566 verbose(VERB_QUERY, "Failed to get a delegation, giving up"); 2567 errinf(qstate, "failed to get a delegation (eg. prime failure)"); 2568 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2569 } 2570 if(!ie->supports_ipv6) 2571 delegpt_no_ipv6(iq->dp); 2572 if(!ie->supports_ipv4 && !ie->use_nat64) 2573 delegpt_no_ipv4(iq->dp); 2574 delegpt_log(VERB_ALGO, iq->dp); 2575 2576 if(iq->num_current_queries>0) { 2577 /* already busy answering a query, this restart is because 2578 * more delegpt addrs became available, wait for existing 2579 * query. */ 2580 verbose(VERB_ALGO, "woke up, but wait for outstanding query"); 2581 qstate->ext_state[id] = module_wait_reply; 2582 return 0; 2583 } 2584 2585 if(iq->minimisation_state == INIT_MINIMISE_STATE 2586 && !(iq->chase_flags & BIT_RD)) { 2587 /* (Re)set qinfo_out to (new) delegation point, except when 2588 * qinfo_out is already a subdomain of dp. This happens when 2589 * increasing by more than one label at once (QNAMEs with more 2590 * than MAX_MINIMISE_COUNT labels). */ 2591 if(!(iq->qinfo_out.qname_len 2592 && dname_subdomain_c(iq->qchase.qname, 2593 iq->qinfo_out.qname) 2594 && dname_subdomain_c(iq->qinfo_out.qname, 2595 iq->dp->name))) { 2596 iq->qinfo_out.qname = iq->dp->name; 2597 iq->qinfo_out.qname_len = iq->dp->namelen; 2598 iq->qinfo_out.qtype = LDNS_RR_TYPE_A; 2599 iq->qinfo_out.qclass = iq->qchase.qclass; 2600 iq->qinfo_out.local_alias = NULL; 2601 iq->minimise_count = 0; 2602 } 2603 2604 iq->minimisation_state = MINIMISE_STATE; 2605 } 2606 if(iq->minimisation_state == MINIMISE_STATE) { 2607 int qchaselabs = dname_count_labels(iq->qchase.qname); 2608 int labdiff = qchaselabs - 2609 dname_count_labels(iq->qinfo_out.qname); 2610 2611 qout_orig = iq->qinfo_out.qname; 2612 qout_orig_len = iq->qinfo_out.qname_len; 2613 iq->qinfo_out.qname = iq->qchase.qname; 2614 iq->qinfo_out.qname_len = iq->qchase.qname_len; 2615 iq->minimise_count++; 2616 iq->timeout_count = 0; 2617 2618 iter_dec_attempts(iq->dp, 1, ie->outbound_msg_retry); 2619 2620 /* Limit number of iterations for QNAMEs with more 2621 * than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB 2622 * labels of QNAME always individually. 2623 */ 2624 if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 && 2625 iq->minimise_count > MINIMISE_ONE_LAB) { 2626 if(iq->minimise_count < MAX_MINIMISE_COUNT) { 2627 int multilabs = qchaselabs - 1 - 2628 MINIMISE_ONE_LAB; 2629 int extralabs = multilabs / 2630 MINIMISE_MULTIPLE_LABS; 2631 2632 if (MAX_MINIMISE_COUNT - iq->minimise_count >= 2633 multilabs % MINIMISE_MULTIPLE_LABS) 2634 /* Default behaviour is to add 1 label 2635 * every iteration. Therefore, decrement 2636 * the extralabs by 1 */ 2637 extralabs--; 2638 if (extralabs < labdiff) 2639 labdiff -= extralabs; 2640 else 2641 labdiff = 1; 2642 } 2643 /* Last minimised iteration, send all labels with 2644 * QTYPE=NS */ 2645 else 2646 labdiff = 1; 2647 } 2648 2649 if(labdiff > 1) { 2650 verbose(VERB_QUERY, "removing %d labels", labdiff-1); 2651 dname_remove_labels(&iq->qinfo_out.qname, 2652 &iq->qinfo_out.qname_len, 2653 labdiff-1); 2654 } 2655 if(labdiff < 1 || (labdiff < 2 2656 && (iq->qchase.qtype == LDNS_RR_TYPE_DS 2657 || iq->qchase.qtype == LDNS_RR_TYPE_A))) 2658 /* Stop minimising this query, resolve "as usual" */ 2659 iq->minimisation_state = DONOT_MINIMISE_STATE; 2660 else if(!qstate->no_cache_lookup) { 2661 struct dns_msg* msg = dns_cache_lookup(qstate->env, 2662 iq->qinfo_out.qname, iq->qinfo_out.qname_len, 2663 iq->qinfo_out.qtype, iq->qinfo_out.qclass, 2664 qstate->query_flags, qstate->region, 2665 qstate->env->scratch, 0, iq->dp->name, 2666 iq->dp->namelen); 2667 if(msg && FLAGS_GET_RCODE(msg->rep->flags) == 2668 LDNS_RCODE_NOERROR) 2669 /* no need to send query if it is already 2670 * cached as NOERROR */ 2671 return 1; 2672 if(msg && FLAGS_GET_RCODE(msg->rep->flags) == 2673 LDNS_RCODE_NXDOMAIN && 2674 qstate->env->need_to_validate && 2675 qstate->env->cfg->harden_below_nxdomain) { 2676 if(msg->rep->security == sec_status_secure) { 2677 iq->response = msg; 2678 return final_state(iq); 2679 } 2680 if(msg->rep->security == sec_status_unchecked) { 2681 struct module_qstate* subq = NULL; 2682 if(!generate_sub_request( 2683 iq->qinfo_out.qname, 2684 iq->qinfo_out.qname_len, 2685 iq->qinfo_out.qtype, 2686 iq->qinfo_out.qclass, 2687 qstate, id, iq, 2688 INIT_REQUEST_STATE, 2689 FINISHED_STATE, &subq, 1, 1)) 2690 verbose(VERB_ALGO, 2691 "could not validate NXDOMAIN " 2692 "response"); 2693 } 2694 } 2695 if(msg && FLAGS_GET_RCODE(msg->rep->flags) == 2696 LDNS_RCODE_NXDOMAIN) { 2697 /* return and add a label in the next 2698 * minimisation iteration. 2699 */ 2700 return 1; 2701 } 2702 } 2703 } 2704 if(iq->minimisation_state == SKIP_MINIMISE_STATE) { 2705 if(iq->timeout_count < MAX_MINIMISE_TIMEOUT_COUNT) 2706 /* Do not increment qname, continue incrementing next 2707 * iteration */ 2708 iq->minimisation_state = MINIMISE_STATE; 2709 else if(!qstate->env->cfg->qname_minimisation_strict) 2710 /* Too many time-outs detected for this QNAME and QTYPE. 2711 * We give up, disable QNAME minimisation. */ 2712 iq->minimisation_state = DONOT_MINIMISE_STATE; 2713 } 2714 if(iq->minimisation_state == DONOT_MINIMISE_STATE) 2715 iq->qinfo_out = iq->qchase; 2716 2717 /* now find an answer to this query */ 2718 /* see if authority zones have an answer */ 2719 /* now we know the dp, we can check the auth zone for locally hosted 2720 * contents */ 2721 if(!iq->auth_zone_avoid && qstate->blacklist) { 2722 if(auth_zones_can_fallback(qstate->env->auth_zones, 2723 iq->dp->name, iq->dp->namelen, iq->qinfo_out.qclass)) { 2724 /* if cache is blacklisted and this zone allows us 2725 * to fallback to the internet, then do so, and 2726 * fetch results from the internet servers */ 2727 iq->auth_zone_avoid = 1; 2728 } 2729 } 2730 if(iq->auth_zone_avoid) { 2731 iq->auth_zone_avoid = 0; 2732 auth_fallback = 1; 2733 } else if(auth_zones_lookup(qstate->env->auth_zones, &iq->qinfo_out, 2734 qstate->region, &iq->response, &auth_fallback, iq->dp->name, 2735 iq->dp->namelen)) { 2736 /* use this as a response to be processed by the iterator */ 2737 if(verbosity >= VERB_ALGO) { 2738 log_dns_msg("msg from auth zone", 2739 &iq->response->qinfo, iq->response->rep); 2740 } 2741 if((iq->chase_flags&BIT_RD) && !(iq->response->rep->flags&BIT_AA)) { 2742 verbose(VERB_ALGO, "forwarder, ignoring referral from auth zone"); 2743 } else { 2744 lock_rw_wrlock(&qstate->env->auth_zones->lock); 2745 qstate->env->auth_zones->num_query_up++; 2746 lock_rw_unlock(&qstate->env->auth_zones->lock); 2747 iq->num_current_queries++; 2748 iq->chase_to_rd = 0; 2749 iq->dnssec_lame_query = 0; 2750 iq->auth_zone_response = 1; 2751 return next_state(iq, QUERY_RESP_STATE); 2752 } 2753 } 2754 iq->auth_zone_response = 0; 2755 if(auth_fallback == 0) { 2756 /* like we got servfail from the auth zone lookup, and 2757 * no internet fallback */ 2758 verbose(VERB_ALGO, "auth zone lookup failed, no fallback," 2759 " servfail"); 2760 errinf(qstate, "auth zone lookup failed, fallback is off"); 2761 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2762 } 2763 if(iq->dp->auth_dp) { 2764 /* we wanted to fallback, but had no delegpt, only the 2765 * auth zone generated delegpt, create an actual one */ 2766 iq->auth_zone_avoid = 1; 2767 return next_state(iq, INIT_REQUEST_STATE); 2768 } 2769 /* but mostly, fallback==1 (like, when no such auth zone exists) 2770 * and we continue with lookups */ 2771 2772 tf_policy = 0; 2773 /* < not <=, because although the array is large enough for <=, the 2774 * generated query will immediately be discarded due to depth and 2775 * that servfail is cached, which is not good as opportunism goes. */ 2776 if(iq->depth < ie->max_dependency_depth 2777 && iq->num_target_queries == 0 2778 && (!iq->target_count || iq->target_count[TARGET_COUNT_NX]==0) 2779 && iq->sent_count < TARGET_FETCH_STOP) { 2780 can_do_promisc = 1; 2781 } 2782 /* if the mesh query list is full, then do not waste cpu and sockets to 2783 * fetch promiscuous targets. They can be looked up when needed. */ 2784 if(can_do_promisc && !mesh_jostle_exceeded(qstate->env->mesh)) { 2785 tf_policy = ie->target_fetch_policy[iq->depth]; 2786 } 2787 2788 /* if in 0x20 fallback get as many targets as possible */ 2789 if(iq->caps_fallback) { 2790 int extra = 0, ret; 2791 size_t naddr, nres, navail; 2792 if((ret=query_for_targets(qstate, iq, ie, id, -1, &extra))!=0) { 2793 errinf(qstate, "could not fetch nameservers for 0x20 fallback"); 2794 if(ret == 1) 2795 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2796 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 2797 } 2798 iq->num_target_queries += extra; 2799 target_count_increase(iq, extra); 2800 if(iq->num_target_queries > 0) { 2801 /* wait to get all targets, we want to try em */ 2802 verbose(VERB_ALGO, "wait for all targets for fallback"); 2803 qstate->ext_state[id] = module_wait_reply; 2804 /* undo qname minimise step because we'll get back here 2805 * to do it again */ 2806 if(qout_orig && iq->minimise_count > 0) { 2807 iq->minimise_count--; 2808 iq->qinfo_out.qname = qout_orig; 2809 iq->qinfo_out.qname_len = qout_orig_len; 2810 } 2811 return 0; 2812 } 2813 /* did we do enough fallback queries already? */ 2814 delegpt_count_addr(iq->dp, &naddr, &nres, &navail); 2815 /* the current caps_server is the number of fallbacks sent. 2816 * the original query is one that matched too, so we have 2817 * caps_server+1 number of matching queries now */ 2818 if(iq->caps_server+1 >= naddr*3 || 2819 iq->caps_server*2+2 >= (size_t)ie->max_sent_count) { 2820 /* *2 on sentcount check because ipv6 may fail */ 2821 /* we're done, process the response */ 2822 verbose(VERB_ALGO, "0x20 fallback had %d responses " 2823 "match for %d wanted, done.", 2824 (int)iq->caps_server+1, (int)naddr*3); 2825 iq->response = iq->caps_response; 2826 iq->caps_fallback = 0; 2827 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry); /* space for fallback */ 2828 iq->num_current_queries++; /* RespState decrements it*/ 2829 iq->referral_count++; /* make sure we don't loop */ 2830 iq->sent_count = 0; 2831 iq->dp_target_count = 0; 2832 iq->state = QUERY_RESP_STATE; 2833 return 1; 2834 } 2835 verbose(VERB_ALGO, "0x20 fallback number %d", 2836 (int)iq->caps_server); 2837 2838 /* if there is a policy to fetch missing targets 2839 * opportunistically, do it. we rely on the fact that once a 2840 * query (or queries) for a missing name have been issued, 2841 * they will not show up again. */ 2842 } else if(tf_policy != 0) { 2843 int extra = 0; 2844 verbose(VERB_ALGO, "attempt to get extra %d targets", 2845 tf_policy); 2846 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra); 2847 /* errors ignored, these targets are not strictly necessary for 2848 * this result, we do not have to reply with SERVFAIL */ 2849 iq->num_target_queries += extra; 2850 target_count_increase(iq, extra); 2851 } 2852 2853 /* Add the current set of unused targets to our queue. */ 2854 delegpt_add_unused_targets(iq->dp); 2855 2856 if(qstate->env->auth_zones) { 2857 uint8_t* sname = NULL; 2858 size_t snamelen = 0; 2859 /* apply rpz triggers at query time; nameserver IP and dname */ 2860 struct dns_msg* forged_response_after_cname; 2861 struct dns_msg* forged_response = rpz_callback_from_iterator_module(qstate, iq); 2862 int count = 0; 2863 while(forged_response && reply_find_rrset_section_an( 2864 forged_response->rep, iq->qchase.qname, 2865 iq->qchase.qname_len, LDNS_RR_TYPE_CNAME, 2866 iq->qchase.qclass) && 2867 iq->qchase.qtype != LDNS_RR_TYPE_CNAME && 2868 count++ < ie->max_query_restarts) { 2869 /* another cname to follow */ 2870 if(!handle_cname_response(qstate, iq, forged_response, 2871 &sname, &snamelen)) { 2872 errinf(qstate, "malloc failure, CNAME info"); 2873 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2874 } 2875 iq->qchase.qname = sname; 2876 iq->qchase.qname_len = snamelen; 2877 forged_response_after_cname = 2878 rpz_callback_from_iterator_cname(qstate, iq); 2879 if(forged_response_after_cname) { 2880 forged_response = forged_response_after_cname; 2881 } else { 2882 /* Follow the CNAME with a query restart */ 2883 iq->deleg_msg = NULL; 2884 iq->dp = NULL; 2885 iq->dsns_point = NULL; 2886 iq->auth_zone_response = 0; 2887 iq->refetch_glue = 0; 2888 iq->query_restart_count++; 2889 iq->sent_count = 0; 2890 iq->dp_target_count = 0; 2891 if(qstate->env->cfg->qname_minimisation) 2892 iq->minimisation_state = INIT_MINIMISE_STATE; 2893 outbound_list_clear(&iq->outlist); 2894 iq->num_current_queries = 0; 2895 fptr_ok(fptr_whitelist_modenv_detach_subs( 2896 qstate->env->detach_subs)); 2897 (*qstate->env->detach_subs)(qstate); 2898 iq->num_target_queries = 0; 2899 return next_state(iq, INIT_REQUEST_STATE); 2900 } 2901 } 2902 if(forged_response != NULL) { 2903 qstate->ext_state[id] = module_finished; 2904 qstate->return_rcode = LDNS_RCODE_NOERROR; 2905 qstate->return_msg = forged_response; 2906 iq->response = forged_response; 2907 next_state(iq, FINISHED_STATE); 2908 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) { 2909 log_err("rpz: prepend rrsets: out of memory"); 2910 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2911 } 2912 return 0; 2913 } 2914 } 2915 2916 /* Select the next usable target, filtering out unsuitable targets. */ 2917 target = iter_server_selection(ie, qstate->env, iq->dp, 2918 iq->dp->name, iq->dp->namelen, iq->qchase.qtype, 2919 &iq->dnssec_lame_query, &iq->chase_to_rd, 2920 iq->num_target_queries, qstate->blacklist, 2921 qstate->prefetch_leeway); 2922 2923 /* If no usable target was selected... */ 2924 if(!target) { 2925 /* Here we distinguish between three states: generate a new 2926 * target query, just wait, or quit (with a SERVFAIL). 2927 * We have the following information: number of active 2928 * target queries, number of active current queries, 2929 * the presence of missing targets at this delegation 2930 * point, and the given query target policy. */ 2931 2932 /* Check for the wait condition. If this is true, then 2933 * an action must be taken. */ 2934 if(iq->num_target_queries==0 && iq->num_current_queries==0) { 2935 /* If there is nothing to wait for, then we need 2936 * to distinguish between generating (a) new target 2937 * query, or failing. */ 2938 if(delegpt_count_missing_targets(iq->dp, NULL) > 0) { 2939 int qs = 0, ret; 2940 verbose(VERB_ALGO, "querying for next " 2941 "missing target"); 2942 if((ret=query_for_targets(qstate, iq, ie, id, 2943 1, &qs))!=0) { 2944 errinf(qstate, "could not fetch nameserver"); 2945 errinf_dname(qstate, "at zone", iq->dp->name); 2946 if(ret == 1) 2947 return error_response(qstate, id, 2948 LDNS_RCODE_SERVFAIL); 2949 return error_response_cache(qstate, id, 2950 LDNS_RCODE_SERVFAIL); 2951 } 2952 if(qs == 0 && 2953 delegpt_count_missing_targets(iq->dp, NULL) == 0){ 2954 /* it looked like there were missing 2955 * targets, but they did not turn up. 2956 * Try the bad choices again (if any), 2957 * when we get back here missing==0, 2958 * so this is not a loop. */ 2959 return 1; 2960 } 2961 if(qs == 0) { 2962 /* There should be targets now, and 2963 * if there are not, it should not 2964 * wait for no targets. Stop it from 2965 * waiting forever, or looping to 2966 * here, as a safeguard. */ 2967 errinf(qstate, "could not generate nameserver lookups"); 2968 errinf_dname(qstate, "at zone", iq->dp->name); 2969 return error_response(qstate, id, 2970 LDNS_RCODE_SERVFAIL); 2971 } 2972 iq->num_target_queries += qs; 2973 target_count_increase(iq, qs); 2974 } 2975 /* Since a target query might have been made, we 2976 * need to check again. */ 2977 if(iq->num_target_queries == 0) { 2978 /* if in capsforid fallback, instead of last 2979 * resort, we agree with the current reply 2980 * we have (if any) (our count of addrs bad)*/ 2981 if(iq->caps_fallback && iq->caps_reply) { 2982 /* we're done, process the response */ 2983 verbose(VERB_ALGO, "0x20 fallback had %d responses, " 2984 "but no more servers except " 2985 "last resort, done.", 2986 (int)iq->caps_server+1); 2987 iq->response = iq->caps_response; 2988 iq->caps_fallback = 0; 2989 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry); /* space for fallback */ 2990 iq->num_current_queries++; /* RespState decrements it*/ 2991 iq->referral_count++; /* make sure we don't loop */ 2992 iq->sent_count = 0; 2993 iq->dp_target_count = 0; 2994 iq->state = QUERY_RESP_STATE; 2995 return 1; 2996 } 2997 return processLastResort(qstate, iq, ie, id); 2998 } 2999 } 3000 3001 /* otherwise, we have no current targets, so submerge 3002 * until one of the target or direct queries return. */ 3003 verbose(VERB_ALGO, "no current targets"); 3004 check_waiting_queries(iq, qstate, id); 3005 /* undo qname minimise step because we'll get back here 3006 * to do it again */ 3007 if(qout_orig && iq->minimise_count > 0) { 3008 iq->minimise_count--; 3009 iq->qinfo_out.qname = qout_orig; 3010 iq->qinfo_out.qname_len = qout_orig_len; 3011 } 3012 return 0; 3013 } 3014 3015 /* We have a target. We could have created promiscuous target 3016 * queries but we are currently under pressure (mesh_jostle_exceeded). 3017 * If we are configured to allow promiscuous target queries and haven't 3018 * gone out to the network for a target query for this delegation, then 3019 * it is possible to slip in a promiscuous one with a 1/10 chance. */ 3020 if(can_do_promisc && tf_policy == 0 && iq->depth == 0 3021 && iq->depth < ie->max_dependency_depth 3022 && ie->target_fetch_policy[iq->depth] != 0 3023 && iq->dp_target_count == 0 3024 && !ub_random_max(qstate->env->rnd, 10)) { 3025 int extra = 0; 3026 verbose(VERB_ALGO, "available target exists in cache but " 3027 "attempt to get extra 1 target"); 3028 (void)query_for_targets(qstate, iq, ie, id, 1, &extra); 3029 /* errors ignored, these targets are not strictly necessary for 3030 * this result, we do not have to reply with SERVFAIL */ 3031 if(extra > 0) { 3032 iq->num_target_queries += extra; 3033 target_count_increase(iq, extra); 3034 check_waiting_queries(iq, qstate, id); 3035 /* undo qname minimise step because we'll get back here 3036 * to do it again */ 3037 if(qout_orig && iq->minimise_count > 0) { 3038 iq->minimise_count--; 3039 iq->qinfo_out.qname = qout_orig; 3040 iq->qinfo_out.qname_len = qout_orig_len; 3041 } 3042 return 0; 3043 } 3044 } 3045 3046 target_count_increase_global_quota(iq, 1); 3047 if(iq->target_count && iq->target_count[TARGET_COUNT_GLOBAL_QUOTA] 3048 > MAX_GLOBAL_QUOTA) { 3049 char s[LDNS_MAX_DOMAINLEN+1]; 3050 dname_str(qstate->qinfo.qname, s); 3051 verbose(VERB_QUERY, "request %s has exceeded the maximum " 3052 "global quota on number of upstream queries %d", s, 3053 iq->target_count[TARGET_COUNT_GLOBAL_QUOTA]); 3054 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 3055 } 3056 3057 /* Do not check ratelimit for forwarding queries or if we already got a 3058 * pass. */ 3059 sq_check_ratelimit = (!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok); 3060 /* We have a valid target. */ 3061 if(verbosity >= VERB_QUERY) { 3062 log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out); 3063 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name, 3064 &target->addr, target->addrlen); 3065 verbose(VERB_ALGO, "dnssec status: %s%s", 3066 iq->dnssec_expected?"expected": "not expected", 3067 iq->dnssec_lame_query?" but lame_query anyway": ""); 3068 } 3069 3070 real_addr = target->addr; 3071 real_addrlen = target->addrlen; 3072 3073 if(ie->use_nat64 && target->addr.ss_family == AF_INET) { 3074 addr_to_nat64(&target->addr, &ie->nat64_prefix_addr, 3075 ie->nat64_prefix_addrlen, ie->nat64_prefix_net, 3076 &real_addr, &real_addrlen); 3077 log_name_addr(VERB_QUERY, "applied NAT64:", 3078 iq->dp->name, &real_addr, real_addrlen); 3079 } 3080 3081 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query)); 3082 outq = (*qstate->env->send_query)(&iq->qinfo_out, 3083 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), 3084 /* unset CD if to forwarder(RD set) and not dnssec retry 3085 * (blacklist nonempty) and no trust-anchors are configured 3086 * above the qname or on the first attempt when dnssec is on */ 3087 (qstate->env->cfg->disable_edns_do?0:EDNS_DO)| 3088 ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&& 3089 !qstate->blacklist&&(!iter_qname_indicates_dnssec(qstate->env, 3090 &iq->qinfo_out)||target->attempts==1)?0:BIT_CD), 3091 iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted( 3092 ie, iq), sq_check_ratelimit, &real_addr, real_addrlen, 3093 iq->dp->name, iq->dp->namelen, 3094 (iq->dp->tcp_upstream || qstate->env->cfg->tcp_upstream), 3095 (iq->dp->ssl_upstream || qstate->env->cfg->ssl_upstream), 3096 target->tls_auth_name, qstate, &sq_was_ratelimited); 3097 if(!outq) { 3098 if(sq_was_ratelimited) { 3099 lock_basic_lock(&ie->queries_ratelimit_lock); 3100 ie->num_queries_ratelimited++; 3101 lock_basic_unlock(&ie->queries_ratelimit_lock); 3102 verbose(VERB_ALGO, "query exceeded ratelimits"); 3103 qstate->was_ratelimited = 1; 3104 errinf_dname(qstate, "exceeded ratelimit for zone", 3105 iq->dp->name); 3106 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 3107 } 3108 log_addr(VERB_QUERY, "error sending query to auth server", 3109 &real_addr, real_addrlen); 3110 if(qstate->env->cfg->qname_minimisation) 3111 iq->minimisation_state = SKIP_MINIMISE_STATE; 3112 return next_state(iq, QUERYTARGETS_STATE); 3113 } 3114 outbound_list_insert(&iq->outlist, outq); 3115 iq->num_current_queries++; 3116 iq->sent_count++; 3117 qstate->ext_state[id] = module_wait_reply; 3118 3119 return 0; 3120 } 3121 3122 /** find NS rrset in given list */ 3123 static struct ub_packed_rrset_key* 3124 find_NS(struct reply_info* rep, size_t from, size_t to) 3125 { 3126 size_t i; 3127 for(i=from; i<to; i++) { 3128 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) 3129 return rep->rrsets[i]; 3130 } 3131 return NULL; 3132 } 3133 3134 3135 /** 3136 * Process the query response. All queries end up at this state first. This 3137 * process generally consists of analyzing the response and routing the 3138 * event to the next state (either bouncing it back to a request state, or 3139 * terminating the processing for this event). 3140 * 3141 * @param qstate: query state. 3142 * @param iq: iterator query state. 3143 * @param ie: iterator shared global environment. 3144 * @param id: module id. 3145 * @return true if the event requires more immediate processing, false if 3146 * not. This is generally only true when forwarding the request to 3147 * the final state (i.e., on answer). 3148 */ 3149 static int 3150 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq, 3151 struct iter_env* ie, int id) 3152 { 3153 int dnsseclame = 0, origtypecname = 0, orig_empty_nodata_found; 3154 enum response_type type; 3155 3156 iq->num_current_queries--; 3157 3158 if(!inplace_cb_query_response_call(qstate->env, qstate, iq->response)) 3159 log_err("unable to call query_response callback"); 3160 3161 if(iq->response == NULL) { 3162 /* Don't increment qname when QNAME minimisation is enabled */ 3163 if(qstate->env->cfg->qname_minimisation) { 3164 iq->minimisation_state = SKIP_MINIMISE_STATE; 3165 } 3166 iq->timeout_count++; 3167 iq->chase_to_rd = 0; 3168 iq->dnssec_lame_query = 0; 3169 verbose(VERB_ALGO, "query response was timeout"); 3170 return next_state(iq, QUERYTARGETS_STATE); 3171 } 3172 iq->timeout_count = 0; 3173 orig_empty_nodata_found = iq->empty_nodata_found; 3174 type = response_type_from_server( 3175 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 3176 iq->response, &iq->qinfo_out, iq->dp, &iq->empty_nodata_found); 3177 iq->chase_to_rd = 0; 3178 /* remove TC flag, if this is erroneously set by TCP upstream */ 3179 iq->response->rep->flags &= ~BIT_TC; 3180 if(orig_empty_nodata_found != iq->empty_nodata_found && 3181 iq->empty_nodata_found < EMPTY_NODATA_RETRY_COUNT) { 3182 /* try to search at another server */ 3183 if(qstate->reply) { 3184 struct delegpt_addr* a = delegpt_find_addr( 3185 iq->dp, &qstate->reply->remote_addr, 3186 qstate->reply->remote_addrlen); 3187 /* make selection disprefer it */ 3188 if(a) a->lame = 1; 3189 } 3190 return next_state(iq, QUERYTARGETS_STATE); 3191 } 3192 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD) && 3193 !iq->auth_zone_response) { 3194 /* When forwarding (RD bit is set), we handle referrals 3195 * differently. No queries should be sent elsewhere */ 3196 type = RESPONSE_TYPE_ANSWER; 3197 } 3198 if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected 3199 && !iq->dnssec_lame_query && 3200 !(iq->chase_flags&BIT_RD) 3201 && iq->sent_count < DNSSEC_LAME_DETECT_COUNT 3202 && type != RESPONSE_TYPE_LAME 3203 && type != RESPONSE_TYPE_REC_LAME 3204 && type != RESPONSE_TYPE_THROWAWAY 3205 && type != RESPONSE_TYPE_UNTYPED) { 3206 /* a possible answer, see if it is missing DNSSEC */ 3207 /* but not when forwarding, so we dont mark fwder lame */ 3208 if(!iter_msg_has_dnssec(iq->response)) { 3209 /* Mark this address as dnsseclame in this dp, 3210 * because that will make serverselection disprefer 3211 * it, but also, once it is the only final option, 3212 * use dnssec-lame-bypass if it needs to query there.*/ 3213 if(qstate->reply) { 3214 struct delegpt_addr* a = delegpt_find_addr( 3215 iq->dp, &qstate->reply->remote_addr, 3216 qstate->reply->remote_addrlen); 3217 if(a) a->dnsseclame = 1; 3218 } 3219 /* test the answer is from the zone we expected, 3220 * otherwise, (due to parent,child on same server), we 3221 * might mark the server,zone lame inappropriately */ 3222 if(!iter_msg_from_zone(iq->response, iq->dp, type, 3223 iq->qchase.qclass)) 3224 qstate->reply = NULL; 3225 type = RESPONSE_TYPE_LAME; 3226 dnsseclame = 1; 3227 } 3228 } else iq->dnssec_lame_query = 0; 3229 /* see if referral brings us close to the target */ 3230 if(type == RESPONSE_TYPE_REFERRAL) { 3231 struct ub_packed_rrset_key* ns = find_NS( 3232 iq->response->rep, iq->response->rep->an_numrrsets, 3233 iq->response->rep->an_numrrsets 3234 + iq->response->rep->ns_numrrsets); 3235 if(!ns) ns = find_NS(iq->response->rep, 0, 3236 iq->response->rep->an_numrrsets); 3237 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name) 3238 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){ 3239 verbose(VERB_ALGO, "bad referral, throwaway"); 3240 type = RESPONSE_TYPE_THROWAWAY; 3241 } else 3242 iter_scrub_ds(iq->response, ns, iq->dp->name); 3243 } else iter_scrub_ds(iq->response, NULL, NULL); 3244 if(type == RESPONSE_TYPE_THROWAWAY && 3245 FLAGS_GET_RCODE(iq->response->rep->flags) == LDNS_RCODE_YXDOMAIN) { 3246 /* YXDOMAIN is a permanent error, no need to retry */ 3247 type = RESPONSE_TYPE_ANSWER; 3248 } 3249 if(type == RESPONSE_TYPE_CNAME) 3250 origtypecname = 1; 3251 if(type == RESPONSE_TYPE_CNAME && iq->response->rep->an_numrrsets >= 1 3252 && ntohs(iq->response->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DNAME) { 3253 uint8_t* sname = NULL; 3254 size_t snamelen = 0; 3255 get_cname_target(iq->response->rep->rrsets[0], &sname, 3256 &snamelen); 3257 if(snamelen && dname_subdomain_c(sname, iq->response->rep->rrsets[0]->rk.dname)) { 3258 /* DNAME to a subdomain loop; do not recurse */ 3259 type = RESPONSE_TYPE_ANSWER; 3260 } 3261 } 3262 if(type == RESPONSE_TYPE_CNAME && 3263 iq->qchase.qtype == LDNS_RR_TYPE_CNAME && 3264 iq->minimisation_state == MINIMISE_STATE && 3265 query_dname_compare(iq->qchase.qname, iq->qinfo_out.qname) == 0) { 3266 /* The minimised query for full QTYPE and hidden QTYPE can be 3267 * classified as CNAME response type, even when the original 3268 * QTYPE=CNAME. This should be treated as answer response type. 3269 */ 3270 type = RESPONSE_TYPE_ANSWER; 3271 } 3272 3273 /* handle each of the type cases */ 3274 if(type == RESPONSE_TYPE_ANSWER) { 3275 /* ANSWER type responses terminate the query algorithm, 3276 * so they sent on their */ 3277 if(verbosity >= VERB_DETAIL) { 3278 verbose(VERB_DETAIL, "query response was %s", 3279 FLAGS_GET_RCODE(iq->response->rep->flags) 3280 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER": 3281 (iq->response->rep->an_numrrsets?"ANSWER": 3282 "nodata ANSWER")); 3283 } 3284 /* if qtype is DS, check we have the right level of answer, 3285 * like grandchild answer but we need the middle, reject it */ 3286 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 3287 && !(iq->chase_flags&BIT_RD) 3288 && iter_ds_toolow(iq->response, iq->dp) 3289 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 3290 /* close down outstanding requests to be discarded */ 3291 outbound_list_clear(&iq->outlist); 3292 iq->num_current_queries = 0; 3293 fptr_ok(fptr_whitelist_modenv_detach_subs( 3294 qstate->env->detach_subs)); 3295 (*qstate->env->detach_subs)(qstate); 3296 iq->num_target_queries = 0; 3297 return processDSNSFind(qstate, iq, id); 3298 } 3299 if(!qstate->no_cache_store) 3300 iter_dns_store(qstate->env, &iq->response->qinfo, 3301 iq->response->rep, 3302 iq->qchase.qtype != iq->response->qinfo.qtype, 3303 qstate->prefetch_leeway, 3304 iq->dp&&iq->dp->has_parent_side_NS, 3305 qstate->region, qstate->query_flags, 3306 qstate->qstarttime); 3307 /* close down outstanding requests to be discarded */ 3308 outbound_list_clear(&iq->outlist); 3309 iq->num_current_queries = 0; 3310 fptr_ok(fptr_whitelist_modenv_detach_subs( 3311 qstate->env->detach_subs)); 3312 (*qstate->env->detach_subs)(qstate); 3313 iq->num_target_queries = 0; 3314 if(qstate->reply) 3315 sock_list_insert(&qstate->reply_origin, 3316 &qstate->reply->remote_addr, 3317 qstate->reply->remote_addrlen, qstate->region); 3318 if(iq->minimisation_state != DONOT_MINIMISE_STATE 3319 && !(iq->chase_flags & BIT_RD)) { 3320 if(FLAGS_GET_RCODE(iq->response->rep->flags) != 3321 LDNS_RCODE_NOERROR) { 3322 if(qstate->env->cfg->qname_minimisation_strict) { 3323 if(FLAGS_GET_RCODE(iq->response->rep->flags) == 3324 LDNS_RCODE_NXDOMAIN) { 3325 iter_scrub_nxdomain(iq->response); 3326 return final_state(iq); 3327 } 3328 return error_response_cache(qstate, id, 3329 LDNS_RCODE_SERVFAIL); 3330 } 3331 /* Best effort qname-minimisation. 3332 * Stop minimising and send full query when 3333 * RCODE is not NOERROR. */ 3334 iq->minimisation_state = DONOT_MINIMISE_STATE; 3335 } 3336 if(FLAGS_GET_RCODE(iq->response->rep->flags) == 3337 LDNS_RCODE_NXDOMAIN && !origtypecname) { 3338 /* Stop resolving when NXDOMAIN is DNSSEC 3339 * signed. Based on assumption that nameservers 3340 * serving signed zones do not return NXDOMAIN 3341 * for empty-non-terminals. */ 3342 /* If this response is actually a CNAME type, 3343 * the nxdomain rcode may not be for the qname, 3344 * and so it is not the final response. */ 3345 if(iq->dnssec_expected) 3346 return final_state(iq); 3347 /* Make subrequest to validate intermediate 3348 * NXDOMAIN if harden-below-nxdomain is 3349 * enabled. */ 3350 if(qstate->env->cfg->harden_below_nxdomain && 3351 qstate->env->need_to_validate) { 3352 struct module_qstate* subq = NULL; 3353 log_query_info(VERB_QUERY, 3354 "schedule NXDOMAIN validation:", 3355 &iq->response->qinfo); 3356 if(!generate_sub_request( 3357 iq->response->qinfo.qname, 3358 iq->response->qinfo.qname_len, 3359 iq->response->qinfo.qtype, 3360 iq->response->qinfo.qclass, 3361 qstate, id, iq, 3362 INIT_REQUEST_STATE, 3363 FINISHED_STATE, &subq, 1, 1)) 3364 verbose(VERB_ALGO, 3365 "could not validate NXDOMAIN " 3366 "response"); 3367 } 3368 } 3369 return next_state(iq, QUERYTARGETS_STATE); 3370 } 3371 return final_state(iq); 3372 } else if(type == RESPONSE_TYPE_REFERRAL) { 3373 struct delegpt* old_dp = NULL; 3374 /* REFERRAL type responses get a reset of the 3375 * delegation point, and back to the QUERYTARGETS_STATE. */ 3376 verbose(VERB_DETAIL, "query response was REFERRAL"); 3377 3378 /* if hardened, only store referral if we asked for it */ 3379 if(!qstate->no_cache_store && 3380 (!qstate->env->cfg->harden_referral_path || 3381 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS 3382 && (qstate->query_flags&BIT_RD) 3383 && !(qstate->query_flags&BIT_CD) 3384 /* we know that all other NS rrsets are scrubbed 3385 * away, thus on referral only one is left. 3386 * see if that equals the query name... */ 3387 && ( /* auth section, but sometimes in answer section*/ 3388 reply_find_rrset_section_ns(iq->response->rep, 3389 iq->qchase.qname, iq->qchase.qname_len, 3390 LDNS_RR_TYPE_NS, iq->qchase.qclass) 3391 || reply_find_rrset_section_an(iq->response->rep, 3392 iq->qchase.qname, iq->qchase.qname_len, 3393 LDNS_RR_TYPE_NS, iq->qchase.qclass) 3394 ) 3395 ))) { 3396 /* Store the referral under the current query */ 3397 /* no prefetch-leeway, since its not the answer */ 3398 iter_dns_store(qstate->env, &iq->response->qinfo, 3399 iq->response->rep, 1, 0, 0, NULL, 0, 3400 qstate->qstarttime); 3401 if(iq->store_parent_NS) 3402 iter_store_parentside_NS(qstate->env, 3403 iq->response->rep); 3404 if(qstate->env->neg_cache) 3405 val_neg_addreferral(qstate->env->neg_cache, 3406 iq->response->rep, iq->dp->name); 3407 } 3408 /* store parent-side-in-zone-glue, if directly queried for */ 3409 if(!qstate->no_cache_store && iq->query_for_pside_glue 3410 && !iq->pside_glue) { 3411 iq->pside_glue = reply_find_rrset(iq->response->rep, 3412 iq->qchase.qname, iq->qchase.qname_len, 3413 iq->qchase.qtype, iq->qchase.qclass); 3414 if(iq->pside_glue) { 3415 log_rrset_key(VERB_ALGO, "found parent-side " 3416 "glue", iq->pside_glue); 3417 iter_store_parentside_rrset(qstate->env, 3418 iq->pside_glue); 3419 } 3420 } 3421 3422 /* Reset the event state, setting the current delegation 3423 * point to the referral. */ 3424 iq->deleg_msg = iq->response; 3425 /* Keep current delegation point for label comparison */ 3426 old_dp = iq->dp; 3427 iq->dp = delegpt_from_message(iq->response, qstate->region); 3428 if (qstate->env->cfg->qname_minimisation) 3429 iq->minimisation_state = INIT_MINIMISE_STATE; 3430 if(!iq->dp) { 3431 errinf(qstate, "malloc failure, for delegation point"); 3432 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3433 } 3434 if(old_dp->namelabs + 1 < iq->dp->namelabs) { 3435 /* We got a grandchild delegation (more than one label 3436 * difference) than expected. Check for in-between 3437 * delegations in the cache and remove them. 3438 * They could prove problematic when they expire 3439 * and rrset_expired_above() encounters them during 3440 * delegation cache lookups. */ 3441 uint8_t* qname = iq->dp->name; 3442 size_t qnamelen = iq->dp->namelen; 3443 rrset_cache_remove_above(qstate->env->rrset_cache, 3444 &qname, &qnamelen, LDNS_RR_TYPE_NS, 3445 iq->qchase.qclass, *qstate->env->now, 3446 old_dp->name, old_dp->namelen); 3447 } 3448 if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 3449 qstate->region, iq->dp, 0)) { 3450 errinf(qstate, "malloc failure, copy extra info into delegation point"); 3451 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3452 } 3453 if(iq->store_parent_NS && query_dname_compare(iq->dp->name, 3454 iq->store_parent_NS->name) == 0) 3455 iter_merge_retry_counts(iq->dp, iq->store_parent_NS, 3456 ie->outbound_msg_retry); 3457 delegpt_log(VERB_ALGO, iq->dp); 3458 /* Count this as a referral. */ 3459 iq->referral_count++; 3460 iq->sent_count = 0; 3461 iq->dp_target_count = 0; 3462 /* see if the next dp is a trust anchor, or a DS was sent 3463 * along, indicating dnssec is expected for next zone */ 3464 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, 3465 iq->dp, iq->response, iq->qchase.qclass); 3466 /* if dnssec, validating then also fetch the key for the DS */ 3467 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 3468 !(qstate->query_flags&BIT_CD)) 3469 generate_dnskey_prefetch(qstate, iq, id); 3470 3471 /* spawn off NS and addr to auth servers for the NS we just 3472 * got in the referral. This gets authoritative answer 3473 * (answer section trust level) rrset. 3474 * right after, we detach the subs, answer goes to cache. */ 3475 if(qstate->env->cfg->harden_referral_path) 3476 generate_ns_check(qstate, iq, id); 3477 3478 /* stop current outstanding queries. 3479 * FIXME: should the outstanding queries be waited for and 3480 * handled? Say by a subquery that inherits the outbound_entry. 3481 */ 3482 outbound_list_clear(&iq->outlist); 3483 iq->num_current_queries = 0; 3484 fptr_ok(fptr_whitelist_modenv_detach_subs( 3485 qstate->env->detach_subs)); 3486 (*qstate->env->detach_subs)(qstate); 3487 iq->num_target_queries = 0; 3488 iq->response = NULL; 3489 iq->fail_addr_type = 0; 3490 verbose(VERB_ALGO, "cleared outbound list for next round"); 3491 return next_state(iq, QUERYTARGETS_STATE); 3492 } else if(type == RESPONSE_TYPE_CNAME) { 3493 uint8_t* sname = NULL; 3494 size_t snamelen = 0; 3495 /* CNAME type responses get a query restart (i.e., get a 3496 * reset of the query state and go back to INIT_REQUEST_STATE). 3497 */ 3498 verbose(VERB_DETAIL, "query response was CNAME"); 3499 if(verbosity >= VERB_ALGO) 3500 log_dns_msg("cname msg", &iq->response->qinfo, 3501 iq->response->rep); 3502 /* if qtype is DS, check we have the right level of answer, 3503 * like grandchild answer but we need the middle, reject it */ 3504 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 3505 && !(iq->chase_flags&BIT_RD) 3506 && iter_ds_toolow(iq->response, iq->dp) 3507 && iter_dp_cangodown(&iq->qchase, iq->dp)) { 3508 outbound_list_clear(&iq->outlist); 3509 iq->num_current_queries = 0; 3510 fptr_ok(fptr_whitelist_modenv_detach_subs( 3511 qstate->env->detach_subs)); 3512 (*qstate->env->detach_subs)(qstate); 3513 iq->num_target_queries = 0; 3514 return processDSNSFind(qstate, iq, id); 3515 } 3516 /* Process the CNAME response. */ 3517 if(!handle_cname_response(qstate, iq, iq->response, 3518 &sname, &snamelen)) { 3519 errinf(qstate, "malloc failure, CNAME info"); 3520 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3521 } 3522 /* cache the CNAME response under the current query */ 3523 /* NOTE : set referral=1, so that rrsets get stored but not 3524 * the partial query answer (CNAME only). */ 3525 /* prefetchleeway applied because this updates answer parts */ 3526 if(!qstate->no_cache_store) 3527 iter_dns_store(qstate->env, &iq->response->qinfo, 3528 iq->response->rep, 1, qstate->prefetch_leeway, 3529 iq->dp&&iq->dp->has_parent_side_NS, NULL, 3530 qstate->query_flags, qstate->qstarttime); 3531 /* set the current request's qname to the new value. */ 3532 iq->qchase.qname = sname; 3533 iq->qchase.qname_len = snamelen; 3534 if(qstate->env->auth_zones) { 3535 /* apply rpz qname triggers after cname */ 3536 struct dns_msg* forged_response = 3537 rpz_callback_from_iterator_cname(qstate, iq); 3538 int count = 0; 3539 while(forged_response && reply_find_rrset_section_an( 3540 forged_response->rep, iq->qchase.qname, 3541 iq->qchase.qname_len, LDNS_RR_TYPE_CNAME, 3542 iq->qchase.qclass) && 3543 iq->qchase.qtype != LDNS_RR_TYPE_CNAME && 3544 count++ < ie->max_query_restarts) { 3545 /* another cname to follow */ 3546 if(!handle_cname_response(qstate, iq, forged_response, 3547 &sname, &snamelen)) { 3548 errinf(qstate, "malloc failure, CNAME info"); 3549 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3550 } 3551 iq->qchase.qname = sname; 3552 iq->qchase.qname_len = snamelen; 3553 forged_response = 3554 rpz_callback_from_iterator_cname(qstate, iq); 3555 } 3556 if(forged_response != NULL) { 3557 qstate->ext_state[id] = module_finished; 3558 qstate->return_rcode = LDNS_RCODE_NOERROR; 3559 qstate->return_msg = forged_response; 3560 iq->response = forged_response; 3561 next_state(iq, FINISHED_STATE); 3562 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) { 3563 log_err("rpz: after cname, prepend rrsets: out of memory"); 3564 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 3565 } 3566 qstate->return_msg->qinfo = qstate->qinfo; 3567 return 0; 3568 } 3569 } 3570 /* Clear the query state, since this is a query restart. */ 3571 iq->deleg_msg = NULL; 3572 iq->dp = NULL; 3573 iq->dsns_point = NULL; 3574 iq->auth_zone_response = 0; 3575 iq->sent_count = 0; 3576 iq->dp_target_count = 0; 3577 if(iq->minimisation_state != MINIMISE_STATE) 3578 /* Only count as query restart when it is not an extra 3579 * query as result of qname minimisation. */ 3580 iq->query_restart_count++; 3581 if(qstate->env->cfg->qname_minimisation) 3582 iq->minimisation_state = INIT_MINIMISE_STATE; 3583 3584 /* stop current outstanding queries. 3585 * FIXME: should the outstanding queries be waited for and 3586 * handled? Say by a subquery that inherits the outbound_entry. 3587 */ 3588 outbound_list_clear(&iq->outlist); 3589 iq->num_current_queries = 0; 3590 fptr_ok(fptr_whitelist_modenv_detach_subs( 3591 qstate->env->detach_subs)); 3592 (*qstate->env->detach_subs)(qstate); 3593 iq->num_target_queries = 0; 3594 if(qstate->reply) 3595 sock_list_insert(&qstate->reply_origin, 3596 &qstate->reply->remote_addr, 3597 qstate->reply->remote_addrlen, qstate->region); 3598 verbose(VERB_ALGO, "cleared outbound list for query restart"); 3599 /* go to INIT_REQUEST_STATE for new qname. */ 3600 return next_state(iq, INIT_REQUEST_STATE); 3601 } else if(type == RESPONSE_TYPE_LAME) { 3602 /* Cache the LAMEness. */ 3603 verbose(VERB_DETAIL, "query response was %sLAME", 3604 dnsseclame?"DNSSEC ":""); 3605 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 3606 log_err("mark lame: mismatch in qname and dpname"); 3607 /* throwaway this reply below */ 3608 } else if(qstate->reply) { 3609 /* need addr for lameness cache, but we may have 3610 * gotten this from cache, so test to be sure */ 3611 if(!infra_set_lame(qstate->env->infra_cache, 3612 &qstate->reply->remote_addr, 3613 qstate->reply->remote_addrlen, 3614 iq->dp->name, iq->dp->namelen, 3615 *qstate->env->now, dnsseclame, 0, 3616 iq->qchase.qtype)) 3617 log_err("mark host lame: out of memory"); 3618 } 3619 } else if(type == RESPONSE_TYPE_REC_LAME) { 3620 /* Cache the LAMEness. */ 3621 verbose(VERB_DETAIL, "query response REC_LAME: " 3622 "recursive but not authoritative server"); 3623 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 3624 log_err("mark rec_lame: mismatch in qname and dpname"); 3625 /* throwaway this reply below */ 3626 } else if(qstate->reply) { 3627 /* need addr for lameness cache, but we may have 3628 * gotten this from cache, so test to be sure */ 3629 verbose(VERB_DETAIL, "mark as REC_LAME"); 3630 if(!infra_set_lame(qstate->env->infra_cache, 3631 &qstate->reply->remote_addr, 3632 qstate->reply->remote_addrlen, 3633 iq->dp->name, iq->dp->namelen, 3634 *qstate->env->now, 0, 1, iq->qchase.qtype)) 3635 log_err("mark host lame: out of memory"); 3636 } 3637 } else if(type == RESPONSE_TYPE_THROWAWAY) { 3638 /* LAME and THROWAWAY responses are handled the same way. 3639 * In this case, the event is just sent directly back to 3640 * the QUERYTARGETS_STATE without resetting anything, 3641 * because, clearly, the next target must be tried. */ 3642 verbose(VERB_DETAIL, "query response was THROWAWAY"); 3643 } else { 3644 log_warn("A query response came back with an unknown type: %d", 3645 (int)type); 3646 } 3647 3648 /* LAME, THROWAWAY and "unknown" all end up here. 3649 * Recycle to the QUERYTARGETS state to hopefully try a 3650 * different target. */ 3651 if (qstate->env->cfg->qname_minimisation && 3652 !qstate->env->cfg->qname_minimisation_strict) 3653 iq->minimisation_state = DONOT_MINIMISE_STATE; 3654 if(iq->auth_zone_response) { 3655 /* can we fallback? */ 3656 iq->auth_zone_response = 0; 3657 if(!auth_zones_can_fallback(qstate->env->auth_zones, 3658 iq->dp->name, iq->dp->namelen, qstate->qinfo.qclass)) { 3659 verbose(VERB_ALGO, "auth zone response bad, and no" 3660 " fallback possible, servfail"); 3661 errinf_dname(qstate, "response is bad, no fallback, " 3662 "for auth zone", iq->dp->name); 3663 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 3664 } 3665 verbose(VERB_ALGO, "auth zone response was bad, " 3666 "fallback enabled"); 3667 iq->auth_zone_avoid = 1; 3668 if(iq->dp->auth_dp) { 3669 /* we are using a dp for the auth zone, with no 3670 * nameservers, get one first */ 3671 iq->dp = NULL; 3672 return next_state(iq, INIT_REQUEST_STATE); 3673 } 3674 } 3675 return next_state(iq, QUERYTARGETS_STATE); 3676 } 3677 3678 /** 3679 * Return priming query results to interested super querystates. 3680 * 3681 * Sets the delegation point and delegation message (not nonRD queries). 3682 * This is a callback from walk_supers. 3683 * 3684 * @param qstate: priming query state that finished. 3685 * @param id: module id. 3686 * @param forq: the qstate for which priming has been done. 3687 */ 3688 static void 3689 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq) 3690 { 3691 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 3692 struct delegpt* dp = NULL; 3693 3694 log_assert(qstate->is_priming || foriq->wait_priming_stub); 3695 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 3696 /* Convert our response to a delegation point */ 3697 dp = delegpt_from_message(qstate->return_msg, forq->region); 3698 if(!dp) { 3699 /* if there is no convertible delegation point, then 3700 * the ANSWER type was (presumably) a negative answer. */ 3701 verbose(VERB_ALGO, "prime response was not a positive " 3702 "ANSWER; failing"); 3703 foriq->dp = NULL; 3704 foriq->state = QUERYTARGETS_STATE; 3705 return; 3706 } 3707 3708 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo); 3709 delegpt_log(VERB_ALGO, dp); 3710 foriq->dp = dp; 3711 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region); 3712 if(!foriq->deleg_msg) { 3713 log_err("copy prime response: out of memory"); 3714 foriq->dp = NULL; 3715 foriq->state = QUERYTARGETS_STATE; 3716 return; 3717 } 3718 3719 /* root priming responses go to init stage 2, priming stub 3720 * responses to to stage 3. */ 3721 if(foriq->wait_priming_stub) { 3722 foriq->state = INIT_REQUEST_3_STATE; 3723 foriq->wait_priming_stub = 0; 3724 } else foriq->state = INIT_REQUEST_2_STATE; 3725 /* because we are finished, the parent will be reactivated */ 3726 } 3727 3728 /** 3729 * This handles the response to a priming query. This is used to handle both 3730 * root and stub priming responses. This is basically the equivalent of the 3731 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat 3732 * REFERRALs as ANSWERS. It will also update and reactivate the originating 3733 * event. 3734 * 3735 * @param qstate: query state. 3736 * @param id: module id. 3737 * @return true if the event needs more immediate processing, false if not. 3738 * This state always returns false. 3739 */ 3740 static int 3741 processPrimeResponse(struct module_qstate* qstate, int id) 3742 { 3743 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 3744 enum response_type type; 3745 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */ 3746 type = response_type_from_server( 3747 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 3748 iq->response, &iq->qchase, iq->dp, NULL); 3749 if(type == RESPONSE_TYPE_ANSWER) { 3750 qstate->return_rcode = LDNS_RCODE_NOERROR; 3751 qstate->return_msg = iq->response; 3752 } else { 3753 errinf(qstate, "prime response did not get an answer"); 3754 errinf_dname(qstate, "for", qstate->qinfo.qname); 3755 qstate->return_rcode = LDNS_RCODE_SERVFAIL; 3756 qstate->return_msg = NULL; 3757 } 3758 3759 /* validate the root or stub after priming (if enabled). 3760 * This is the same query as the prime query, but with validation. 3761 * Now that we are primed, the additional queries that validation 3762 * may need can be resolved. */ 3763 if(qstate->env->cfg->harden_referral_path) { 3764 struct module_qstate* subq = NULL; 3765 log_nametypeclass(VERB_ALGO, "schedule prime validation", 3766 qstate->qinfo.qname, qstate->qinfo.qtype, 3767 qstate->qinfo.qclass); 3768 if(!generate_sub_request(qstate->qinfo.qname, 3769 qstate->qinfo.qname_len, qstate->qinfo.qtype, 3770 qstate->qinfo.qclass, qstate, id, iq, 3771 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) { 3772 verbose(VERB_ALGO, "could not generate prime check"); 3773 } 3774 generate_a_aaaa_check(qstate, iq, id); 3775 } 3776 3777 /* This event is finished. */ 3778 qstate->ext_state[id] = module_finished; 3779 return 0; 3780 } 3781 3782 /** 3783 * Do final processing on responses to target queries. Events reach this 3784 * state after the iterative resolution algorithm terminates. This state is 3785 * responsible for reactivating the original event, and housekeeping related 3786 * to received target responses (caching, updating the current delegation 3787 * point, etc). 3788 * Callback from walk_supers for every super state that is interested in 3789 * the results from this query. 3790 * 3791 * @param qstate: query state. 3792 * @param id: module id. 3793 * @param forq: super query state. 3794 */ 3795 static void 3796 processTargetResponse(struct module_qstate* qstate, int id, 3797 struct module_qstate* forq) 3798 { 3799 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 3800 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 3801 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 3802 struct ub_packed_rrset_key* rrset; 3803 struct delegpt_ns* dpns; 3804 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 3805 3806 foriq->state = QUERYTARGETS_STATE; 3807 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo); 3808 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo); 3809 3810 /* Tell the originating event that this target query has finished 3811 * (regardless if it succeeded or not). */ 3812 foriq->num_target_queries--; 3813 3814 /* check to see if parent event is still interested (in orig name). */ 3815 if(!foriq->dp) { 3816 verbose(VERB_ALGO, "subq: parent not interested, was reset"); 3817 return; /* not interested anymore */ 3818 } 3819 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname, 3820 qstate->qinfo.qname_len); 3821 if(!dpns) { 3822 /* If not interested, just stop processing this event */ 3823 verbose(VERB_ALGO, "subq: parent not interested anymore"); 3824 /* could be because parent was jostled out of the cache, 3825 and a new identical query arrived, that does not want it*/ 3826 return; 3827 } 3828 3829 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */ 3830 if(iq->pside_glue) { 3831 /* if the pside_glue is NULL, then it could not be found, 3832 * the done_pside is already set when created and a cache 3833 * entry created in processFinished so nothing to do here */ 3834 log_rrset_key(VERB_ALGO, "add parentside glue to dp", 3835 iq->pside_glue); 3836 if(!delegpt_add_rrset(foriq->dp, forq->region, 3837 iq->pside_glue, 1, NULL)) 3838 log_err("out of memory adding pside glue"); 3839 } 3840 3841 /* This response is relevant to the current query, so we 3842 * add (attempt to add, anyway) this target(s) and reactivate 3843 * the original event. 3844 * NOTE: we could only look for the AnswerRRset if the 3845 * response type was ANSWER. */ 3846 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep); 3847 if(rrset) { 3848 int additions = 0; 3849 /* if CNAMEs have been followed - add new NS to delegpt. */ 3850 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */ 3851 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname, 3852 rrset->rk.dname_len)) { 3853 /* if dpns->lame then set newcname ns lame too */ 3854 if(!delegpt_add_ns(foriq->dp, forq->region, 3855 rrset->rk.dname, dpns->lame, dpns->tls_auth_name, 3856 dpns->port)) 3857 log_err("out of memory adding cnamed-ns"); 3858 } 3859 /* if dpns->lame then set the address(es) lame too */ 3860 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset, 3861 dpns->lame, &additions)) 3862 log_err("out of memory adding targets"); 3863 if(!additions) { 3864 /* no new addresses, increase the nxns counter, like 3865 * this could be a list of wildcards with no new 3866 * addresses */ 3867 target_count_increase_nx(foriq, 1); 3868 } 3869 verbose(VERB_ALGO, "added target response"); 3870 delegpt_log(VERB_ALGO, foriq->dp); 3871 } else { 3872 verbose(VERB_ALGO, "iterator TargetResponse failed"); 3873 delegpt_mark_neg(dpns, qstate->qinfo.qtype); 3874 if((dpns->got4 == 2 || (!ie->supports_ipv4 && !ie->use_nat64)) && 3875 (dpns->got6 == 2 || !ie->supports_ipv6)) { 3876 dpns->resolved = 1; /* fail the target */ 3877 /* do not count cached answers */ 3878 if(qstate->reply_origin && qstate->reply_origin->len != 0) { 3879 target_count_increase_nx(foriq, 1); 3880 } 3881 } 3882 } 3883 } 3884 3885 /** 3886 * Process response for DS NS Find queries, that attempt to find the delegation 3887 * point where we ask the DS query from. 3888 * 3889 * @param qstate: query state. 3890 * @param id: module id. 3891 * @param forq: super query state. 3892 */ 3893 static void 3894 processDSNSResponse(struct module_qstate* qstate, int id, 3895 struct module_qstate* forq) 3896 { 3897 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 3898 3899 /* if the finished (iq->response) query has no NS set: continue 3900 * up to look for the right dp; nothing to change, do DPNSstate */ 3901 if(qstate->return_rcode != LDNS_RCODE_NOERROR) 3902 return; /* seek further */ 3903 /* find the NS RRset (without allowing CNAMEs) */ 3904 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname, 3905 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS, 3906 qstate->qinfo.qclass)){ 3907 return; /* seek further */ 3908 } 3909 3910 /* else, store as DP and continue at querytargets */ 3911 foriq->state = QUERYTARGETS_STATE; 3912 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region); 3913 if(!foriq->dp) { 3914 log_err("out of memory in dsns dp alloc"); 3915 errinf(qstate, "malloc failure, in DS search"); 3916 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */ 3917 } 3918 /* success, go query the querytargets in the new dp (and go down) */ 3919 } 3920 3921 /** 3922 * Process response for qclass=ANY queries for a particular class. 3923 * Append to result or error-exit. 3924 * 3925 * @param qstate: query state. 3926 * @param id: module id. 3927 * @param forq: super query state. 3928 */ 3929 static void 3930 processClassResponse(struct module_qstate* qstate, int id, 3931 struct module_qstate* forq) 3932 { 3933 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 3934 struct dns_msg* from = qstate->return_msg; 3935 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo); 3936 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo); 3937 if(qstate->return_rcode != LDNS_RCODE_NOERROR) { 3938 /* cause servfail for qclass ANY query */ 3939 foriq->response = NULL; 3940 foriq->state = FINISHED_STATE; 3941 return; 3942 } 3943 /* append result */ 3944 if(!foriq->response) { 3945 /* allocate the response: copy RCODE, sec_state */ 3946 foriq->response = dns_copy_msg(from, forq->region); 3947 if(!foriq->response) { 3948 log_err("malloc failed for qclass ANY response"); 3949 foriq->state = FINISHED_STATE; 3950 return; 3951 } 3952 foriq->response->qinfo.qclass = forq->qinfo.qclass; 3953 /* qclass ANY does not receive the AA flag on replies */ 3954 foriq->response->rep->authoritative = 0; 3955 } else { 3956 struct dns_msg* to = foriq->response; 3957 /* add _from_ this response _to_ existing collection */ 3958 /* if there are records, copy RCODE */ 3959 /* lower sec_state if this message is lower */ 3960 if(from->rep->rrset_count != 0) { 3961 size_t n = from->rep->rrset_count+to->rep->rrset_count; 3962 struct ub_packed_rrset_key** dest, **d; 3963 /* copy appropriate rcode */ 3964 to->rep->flags = from->rep->flags; 3965 /* copy rrsets */ 3966 if(from->rep->rrset_count > RR_COUNT_MAX || 3967 to->rep->rrset_count > RR_COUNT_MAX) { 3968 log_err("malloc failed (too many rrsets) in collect ANY"); 3969 foriq->state = FINISHED_STATE; 3970 return; /* integer overflow protection */ 3971 } 3972 dest = regional_alloc(forq->region, sizeof(dest[0])*n); 3973 if(!dest) { 3974 log_err("malloc failed in collect ANY"); 3975 foriq->state = FINISHED_STATE; 3976 return; 3977 } 3978 d = dest; 3979 /* copy AN */ 3980 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets 3981 * sizeof(dest[0])); 3982 dest += to->rep->an_numrrsets; 3983 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets 3984 * sizeof(dest[0])); 3985 dest += from->rep->an_numrrsets; 3986 /* copy NS */ 3987 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets, 3988 to->rep->ns_numrrsets * sizeof(dest[0])); 3989 dest += to->rep->ns_numrrsets; 3990 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets, 3991 from->rep->ns_numrrsets * sizeof(dest[0])); 3992 dest += from->rep->ns_numrrsets; 3993 /* copy AR */ 3994 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+ 3995 to->rep->ns_numrrsets, 3996 to->rep->ar_numrrsets * sizeof(dest[0])); 3997 dest += to->rep->ar_numrrsets; 3998 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+ 3999 from->rep->ns_numrrsets, 4000 from->rep->ar_numrrsets * sizeof(dest[0])); 4001 /* update counts */ 4002 to->rep->rrsets = d; 4003 to->rep->an_numrrsets += from->rep->an_numrrsets; 4004 to->rep->ns_numrrsets += from->rep->ns_numrrsets; 4005 to->rep->ar_numrrsets += from->rep->ar_numrrsets; 4006 to->rep->rrset_count = n; 4007 } 4008 if(from->rep->security < to->rep->security) /* lowest sec */ 4009 to->rep->security = from->rep->security; 4010 if(from->rep->qdcount != 0) /* insert qd if appropriate */ 4011 to->rep->qdcount = from->rep->qdcount; 4012 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */ 4013 to->rep->ttl = from->rep->ttl; 4014 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl) 4015 to->rep->prefetch_ttl = from->rep->prefetch_ttl; 4016 if(from->rep->serve_expired_ttl < to->rep->serve_expired_ttl) 4017 to->rep->serve_expired_ttl = from->rep->serve_expired_ttl; 4018 if(from->rep->serve_expired_norec_ttl < to->rep->serve_expired_norec_ttl) 4019 to->rep->serve_expired_norec_ttl = from->rep->serve_expired_norec_ttl; 4020 } 4021 /* are we done? */ 4022 foriq->num_current_queries --; 4023 if(foriq->num_current_queries == 0) 4024 foriq->state = FINISHED_STATE; 4025 } 4026 4027 /** 4028 * Collect class ANY responses and make them into one response. This 4029 * state is started and it creates queries for all classes (that have 4030 * root hints). The answers are then collected. 4031 * 4032 * @param qstate: query state. 4033 * @param id: module id. 4034 * @return true if the event needs more immediate processing, false if not. 4035 */ 4036 static int 4037 processCollectClass(struct module_qstate* qstate, int id) 4038 { 4039 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 4040 struct module_qstate* subq; 4041 /* If qchase.qclass == 0 then send out queries for all classes. 4042 * Otherwise, do nothing (wait for all answers to arrive and the 4043 * processClassResponse to put them together, and that moves us 4044 * towards the Finished state when done. */ 4045 if(iq->qchase.qclass == 0) { 4046 uint16_t c = 0; 4047 iq->qchase.qclass = LDNS_RR_CLASS_ANY; 4048 while(iter_get_next_root(qstate->env->hints, 4049 qstate->env->fwds, &c)) { 4050 /* generate query for this class */ 4051 log_nametypeclass(VERB_ALGO, "spawn collect query", 4052 qstate->qinfo.qname, qstate->qinfo.qtype, c); 4053 if(!generate_sub_request(qstate->qinfo.qname, 4054 qstate->qinfo.qname_len, qstate->qinfo.qtype, 4055 c, qstate, id, iq, INIT_REQUEST_STATE, 4056 FINISHED_STATE, &subq, 4057 (int)!(qstate->query_flags&BIT_CD), 0)) { 4058 errinf(qstate, "could not generate class ANY" 4059 " lookup query"); 4060 return error_response(qstate, id, 4061 LDNS_RCODE_SERVFAIL); 4062 } 4063 /* ignore subq, no special init required */ 4064 iq->num_current_queries ++; 4065 if(c == 0xffff) 4066 break; 4067 else c++; 4068 } 4069 /* if no roots are configured at all, return */ 4070 if(iq->num_current_queries == 0) { 4071 verbose(VERB_ALGO, "No root hints or fwds, giving up " 4072 "on qclass ANY"); 4073 return error_response_cache(qstate, id, LDNS_RCODE_REFUSED); 4074 } 4075 /* return false, wait for queries to return */ 4076 } 4077 /* if woke up here because of an answer, wait for more answers */ 4078 return 0; 4079 } 4080 4081 /** 4082 * This handles the final state for first-tier responses (i.e., responses to 4083 * externally generated queries). 4084 * 4085 * @param qstate: query state. 4086 * @param iq: iterator query state. 4087 * @param id: module id. 4088 * @return true if the event needs more processing, false if not. Since this 4089 * is the final state for an event, it always returns false. 4090 */ 4091 static int 4092 processFinished(struct module_qstate* qstate, struct iter_qstate* iq, 4093 int id) 4094 { 4095 log_query_info(VERB_QUERY, "finishing processing for", 4096 &qstate->qinfo); 4097 4098 /* store negative cache element for parent side glue. */ 4099 if(!qstate->no_cache_store && iq->query_for_pside_glue 4100 && !iq->pside_glue) 4101 iter_store_parentside_neg(qstate->env, &qstate->qinfo, 4102 iq->deleg_msg?iq->deleg_msg->rep: 4103 (iq->response?iq->response->rep:NULL)); 4104 if(!iq->response) { 4105 verbose(VERB_ALGO, "No response is set, servfail"); 4106 errinf(qstate, "(no response found at query finish)"); 4107 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4108 } 4109 4110 /* Make sure that the RA flag is set (since the presence of 4111 * this module means that recursion is available) */ 4112 iq->response->rep->flags |= BIT_RA; 4113 4114 /* Clear the AA flag */ 4115 /* FIXME: does this action go here or in some other module? */ 4116 iq->response->rep->flags &= ~BIT_AA; 4117 4118 /* make sure QR flag is on */ 4119 iq->response->rep->flags |= BIT_QR; 4120 4121 /* explicitly set the EDE string to NULL */ 4122 iq->response->rep->reason_bogus_str = NULL; 4123 if((qstate->env->cfg->val_log_level >= 2 || 4124 qstate->env->cfg->log_servfail) && qstate->errinf && 4125 !qstate->env->cfg->val_log_squelch) { 4126 char* err_str = errinf_to_str_misc(qstate); 4127 if(err_str) { 4128 verbose(VERB_ALGO, "iterator EDE: %s", err_str); 4129 iq->response->rep->reason_bogus_str = err_str; 4130 } 4131 } 4132 4133 /* we have finished processing this query */ 4134 qstate->ext_state[id] = module_finished; 4135 4136 /* TODO: we are using a private TTL, trim the response. */ 4137 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */ 4138 4139 /* prepend any items we have accumulated */ 4140 if(iq->an_prepend_list || iq->ns_prepend_list) { 4141 if(!iter_prepend(iq, iq->response, qstate->region)) { 4142 log_err("prepend rrsets: out of memory"); 4143 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4144 } 4145 /* reset the query name back */ 4146 iq->response->qinfo = qstate->qinfo; 4147 /* the security state depends on the combination */ 4148 iq->response->rep->security = sec_status_unchecked; 4149 /* store message with the finished prepended items, 4150 * but only if we did recursion. The nonrecursion referral 4151 * from cache does not need to be stored in the msg cache. */ 4152 if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) { 4153 iter_dns_store(qstate->env, &qstate->qinfo, 4154 iq->response->rep, 0, qstate->prefetch_leeway, 4155 iq->dp&&iq->dp->has_parent_side_NS, 4156 qstate->region, qstate->query_flags, 4157 qstate->qstarttime); 4158 } 4159 } 4160 qstate->return_rcode = LDNS_RCODE_NOERROR; 4161 qstate->return_msg = iq->response; 4162 return 0; 4163 } 4164 4165 /* 4166 * Return priming query results to interested super querystates. 4167 * 4168 * Sets the delegation point and delegation message (not nonRD queries). 4169 * This is a callback from walk_supers. 4170 * 4171 * @param qstate: query state that finished. 4172 * @param id: module id. 4173 * @param super: the qstate to inform. 4174 */ 4175 void 4176 iter_inform_super(struct module_qstate* qstate, int id, 4177 struct module_qstate* super) 4178 { 4179 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY) 4180 processClassResponse(qstate, id, super); 4181 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) 4182 super->minfo[id])->state == DSNS_FIND_STATE) 4183 processDSNSResponse(qstate, id, super); 4184 else if(qstate->return_rcode != LDNS_RCODE_NOERROR) 4185 error_supers(qstate, id, super); 4186 else if(qstate->is_priming) 4187 prime_supers(qstate, id, super); 4188 else processTargetResponse(qstate, id, super); 4189 } 4190 4191 /** 4192 * Handle iterator state. 4193 * Handle events. This is the real processing loop for events, responsible 4194 * for moving events through the various states. If a processing method 4195 * returns true, then it will be advanced to the next state. If false, then 4196 * processing will stop. 4197 * 4198 * @param qstate: query state. 4199 * @param ie: iterator shared global environment. 4200 * @param iq: iterator query state. 4201 * @param id: module id. 4202 */ 4203 static void 4204 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq, 4205 struct iter_env* ie, int id) 4206 { 4207 int cont = 1; 4208 while(cont) { 4209 verbose(VERB_ALGO, "iter_handle processing q with state %s", 4210 iter_state_to_string(iq->state)); 4211 switch(iq->state) { 4212 case INIT_REQUEST_STATE: 4213 cont = processInitRequest(qstate, iq, ie, id); 4214 break; 4215 case INIT_REQUEST_2_STATE: 4216 cont = processInitRequest2(qstate, iq, id); 4217 break; 4218 case INIT_REQUEST_3_STATE: 4219 cont = processInitRequest3(qstate, iq, id); 4220 break; 4221 case QUERYTARGETS_STATE: 4222 cont = processQueryTargets(qstate, iq, ie, id); 4223 break; 4224 case QUERY_RESP_STATE: 4225 cont = processQueryResponse(qstate, iq, ie, id); 4226 break; 4227 case PRIME_RESP_STATE: 4228 cont = processPrimeResponse(qstate, id); 4229 break; 4230 case COLLECT_CLASS_STATE: 4231 cont = processCollectClass(qstate, id); 4232 break; 4233 case DSNS_FIND_STATE: 4234 cont = processDSNSFind(qstate, iq, id); 4235 break; 4236 case FINISHED_STATE: 4237 cont = processFinished(qstate, iq, id); 4238 break; 4239 default: 4240 log_warn("iterator: invalid state: %d", 4241 iq->state); 4242 cont = 0; 4243 break; 4244 } 4245 } 4246 } 4247 4248 /** 4249 * This is the primary entry point for processing request events. Note that 4250 * this method should only be used by external modules. 4251 * @param qstate: query state. 4252 * @param ie: iterator shared global environment. 4253 * @param iq: iterator query state. 4254 * @param id: module id. 4255 */ 4256 static void 4257 process_request(struct module_qstate* qstate, struct iter_qstate* iq, 4258 struct iter_env* ie, int id) 4259 { 4260 /* external requests start in the INIT state, and finish using the 4261 * FINISHED state. */ 4262 iq->state = INIT_REQUEST_STATE; 4263 iq->final_state = FINISHED_STATE; 4264 verbose(VERB_ALGO, "process_request: new external request event"); 4265 iter_handle(qstate, iq, ie, id); 4266 } 4267 4268 /** process authoritative server reply */ 4269 static void 4270 process_response(struct module_qstate* qstate, struct iter_qstate* iq, 4271 struct iter_env* ie, int id, struct outbound_entry* outbound, 4272 enum module_ev event) 4273 { 4274 struct msg_parse* prs; 4275 struct edns_data edns; 4276 sldns_buffer* pkt; 4277 4278 verbose(VERB_ALGO, "process_response: new external response event"); 4279 iq->response = NULL; 4280 iq->state = QUERY_RESP_STATE; 4281 if(event == module_event_noreply || event == module_event_error) { 4282 if(event == module_event_noreply && iq->timeout_count >= 3 && 4283 qstate->env->cfg->use_caps_bits_for_id && 4284 !iq->caps_fallback && !is_caps_whitelisted(ie, iq)) { 4285 /* start fallback */ 4286 iq->caps_fallback = 1; 4287 iq->caps_server = 0; 4288 iq->caps_reply = NULL; 4289 iq->caps_response = NULL; 4290 iq->caps_minimisation_state = DONOT_MINIMISE_STATE; 4291 iq->state = QUERYTARGETS_STATE; 4292 iq->num_current_queries--; 4293 /* need fresh attempts for the 0x20 fallback, if 4294 * that was the cause for the failure */ 4295 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry); 4296 verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback"); 4297 goto handle_it; 4298 } 4299 goto handle_it; 4300 } 4301 if( (event != module_event_reply && event != module_event_capsfail) 4302 || !qstate->reply) { 4303 log_err("Bad event combined with response"); 4304 outbound_list_remove(&iq->outlist, outbound); 4305 errinf(qstate, "module iterator received wrong internal event with a response message"); 4306 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4307 return; 4308 } 4309 4310 /* parse message */ 4311 fill_fail_addr(iq, &qstate->reply->remote_addr, 4312 qstate->reply->remote_addrlen); 4313 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch, 4314 sizeof(struct msg_parse)); 4315 if(!prs) { 4316 log_err("out of memory on incoming message"); 4317 /* like packet got dropped */ 4318 goto handle_it; 4319 } 4320 memset(prs, 0, sizeof(*prs)); 4321 memset(&edns, 0, sizeof(edns)); 4322 pkt = qstate->reply->c->buffer; 4323 sldns_buffer_set_position(pkt, 0); 4324 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) { 4325 verbose(VERB_ALGO, "parse error on reply packet"); 4326 iq->parse_failures++; 4327 goto handle_it; 4328 } 4329 /* edns is not examined, but removed from message to help cache */ 4330 if(parse_extract_edns_from_response_msg(prs, &edns, qstate->env->scratch) != 4331 LDNS_RCODE_NOERROR) { 4332 iq->parse_failures++; 4333 goto handle_it; 4334 } 4335 4336 /* Copy the edns options we may got from the back end */ 4337 if(edns.opt_list_in) { 4338 qstate->edns_opts_back_in = edns_opt_copy_region(edns.opt_list_in, 4339 qstate->region); 4340 if(!qstate->edns_opts_back_in) { 4341 log_err("out of memory on incoming message"); 4342 /* like packet got dropped */ 4343 goto handle_it; 4344 } 4345 } 4346 if(!inplace_cb_edns_back_parsed_call(qstate->env, qstate)) { 4347 log_err("unable to call edns_back_parsed callback"); 4348 goto handle_it; 4349 } 4350 4351 /* remove CD-bit, we asked for in case we handle validation ourself */ 4352 prs->flags &= ~BIT_CD; 4353 4354 /* normalize and sanitize: easy to delete items from linked lists */ 4355 if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name, 4356 qstate->env->scratch, qstate->env, qstate, ie)) { 4357 /* if 0x20 enabled, start fallback, but we have no message */ 4358 if(event == module_event_capsfail && !iq->caps_fallback) { 4359 iq->caps_fallback = 1; 4360 iq->caps_server = 0; 4361 iq->caps_reply = NULL; 4362 iq->caps_response = NULL; 4363 iq->caps_minimisation_state = DONOT_MINIMISE_STATE; 4364 iq->state = QUERYTARGETS_STATE; 4365 iq->num_current_queries--; 4366 verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response"); 4367 } 4368 iq->scrub_failures++; 4369 goto handle_it; 4370 } 4371 4372 /* allocate response dns_msg in region */ 4373 iq->response = dns_alloc_msg(pkt, prs, qstate->region); 4374 if(!iq->response) 4375 goto handle_it; 4376 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo); 4377 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name, 4378 &qstate->reply->remote_addr, qstate->reply->remote_addrlen); 4379 if(verbosity >= VERB_ALGO) 4380 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo, 4381 iq->response->rep); 4382 4383 if(qstate->env->cfg->aggressive_nsec) { 4384 limit_nsec_ttl(iq->response); 4385 } 4386 if(event == module_event_capsfail || iq->caps_fallback) { 4387 if(qstate->env->cfg->qname_minimisation && 4388 iq->minimisation_state != DONOT_MINIMISE_STATE) { 4389 /* Skip QNAME minimisation for next query, since that 4390 * one has to match the current query. */ 4391 iq->minimisation_state = SKIP_MINIMISE_STATE; 4392 } 4393 /* for fallback we care about main answer, not additionals */ 4394 /* removing that makes comparison more likely to succeed */ 4395 caps_strip_reply(iq->response->rep); 4396 4397 if(iq->caps_fallback && 4398 iq->caps_minimisation_state != iq->minimisation_state) { 4399 /* QNAME minimisation state has changed, restart caps 4400 * fallback. */ 4401 iq->caps_fallback = 0; 4402 } 4403 4404 if(!iq->caps_fallback) { 4405 /* start fallback */ 4406 iq->caps_fallback = 1; 4407 iq->caps_server = 0; 4408 iq->caps_reply = iq->response->rep; 4409 iq->caps_response = iq->response; 4410 iq->caps_minimisation_state = iq->minimisation_state; 4411 iq->state = QUERYTARGETS_STATE; 4412 iq->num_current_queries--; 4413 verbose(VERB_DETAIL, "Capsforid: starting fallback"); 4414 goto handle_it; 4415 } else { 4416 /* check if reply is the same, otherwise, fail */ 4417 if(!iq->caps_reply) { 4418 iq->caps_reply = iq->response->rep; 4419 iq->caps_response = iq->response; 4420 iq->caps_server = -1; /*become zero at ++, 4421 so that we start the full set of trials */ 4422 } else if(caps_failed_rcode(iq->caps_reply) && 4423 !caps_failed_rcode(iq->response->rep)) { 4424 /* prefer to upgrade to non-SERVFAIL */ 4425 iq->caps_reply = iq->response->rep; 4426 iq->caps_response = iq->response; 4427 } else if(!caps_failed_rcode(iq->caps_reply) && 4428 caps_failed_rcode(iq->response->rep)) { 4429 /* if we have non-SERVFAIL as answer then 4430 * we can ignore SERVFAILs for the equality 4431 * comparison */ 4432 /* no instructions here, skip other else */ 4433 } else if(caps_failed_rcode(iq->caps_reply) && 4434 caps_failed_rcode(iq->response->rep)) { 4435 /* failure is same as other failure in fallbk*/ 4436 /* no instructions here, skip other else */ 4437 } else if(!reply_equal(iq->response->rep, iq->caps_reply, 4438 qstate->env->scratch)) { 4439 verbose(VERB_DETAIL, "Capsforid fallback: " 4440 "getting different replies, failed"); 4441 outbound_list_remove(&iq->outlist, outbound); 4442 errinf(qstate, "0x20 failed, then got different replies in fallback"); 4443 (void)error_response_cache(qstate, id, 4444 LDNS_RCODE_SERVFAIL); 4445 return; 4446 } 4447 /* continue the fallback procedure at next server */ 4448 iq->caps_server++; 4449 iq->state = QUERYTARGETS_STATE; 4450 iq->num_current_queries--; 4451 verbose(VERB_DETAIL, "Capsforid: reply is equal. " 4452 "go to next fallback"); 4453 goto handle_it; 4454 } 4455 } 4456 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */ 4457 4458 handle_it: 4459 outbound_list_remove(&iq->outlist, outbound); 4460 iter_handle(qstate, iq, ie, id); 4461 } 4462 4463 void 4464 iter_operate(struct module_qstate* qstate, enum module_ev event, int id, 4465 struct outbound_entry* outbound) 4466 { 4467 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 4468 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 4469 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s", 4470 id, strextstate(qstate->ext_state[id]), strmodulevent(event)); 4471 if(iq) log_query_info(VERB_QUERY, "iterator operate: query", 4472 &qstate->qinfo); 4473 if(iq && qstate->qinfo.qname != iq->qchase.qname) 4474 log_query_info(VERB_QUERY, "iterator operate: chased to", 4475 &iq->qchase); 4476 4477 /* perform iterator state machine */ 4478 if((event == module_event_new || event == module_event_pass) && 4479 iq == NULL) { 4480 if(!iter_new(qstate, id)) { 4481 errinf(qstate, "malloc failure, new iterator module allocation"); 4482 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4483 return; 4484 } 4485 iq = (struct iter_qstate*)qstate->minfo[id]; 4486 process_request(qstate, iq, ie, id); 4487 return; 4488 } 4489 if(iq && event == module_event_pass) { 4490 iter_handle(qstate, iq, ie, id); 4491 return; 4492 } 4493 if(iq && outbound) { 4494 process_response(qstate, iq, ie, id, outbound, event); 4495 return; 4496 } 4497 if(event == module_event_error) { 4498 verbose(VERB_ALGO, "got called with event error, giving up"); 4499 errinf(qstate, "iterator module got the error event"); 4500 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4501 return; 4502 } 4503 4504 log_err("bad event for iterator"); 4505 errinf(qstate, "iterator module received wrong event"); 4506 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 4507 } 4508 4509 void 4510 iter_clear(struct module_qstate* qstate, int id) 4511 { 4512 struct iter_qstate* iq; 4513 if(!qstate) 4514 return; 4515 iq = (struct iter_qstate*)qstate->minfo[id]; 4516 if(iq) { 4517 outbound_list_clear(&iq->outlist); 4518 if(iq->target_count && --iq->target_count[TARGET_COUNT_REF] == 0) { 4519 free(iq->target_count); 4520 if(*iq->nxns_dp) free(*iq->nxns_dp); 4521 free(iq->nxns_dp); 4522 } 4523 iq->num_current_queries = 0; 4524 } 4525 qstate->minfo[id] = NULL; 4526 } 4527 4528 size_t 4529 iter_get_mem(struct module_env* env, int id) 4530 { 4531 struct iter_env* ie = (struct iter_env*)env->modinfo[id]; 4532 if(!ie) 4533 return 0; 4534 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1) 4535 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv); 4536 } 4537 4538 /** 4539 * The iterator function block 4540 */ 4541 static struct module_func_block iter_block = { 4542 "iterator", 4543 NULL, NULL, &iter_init, &iter_deinit, &iter_operate, 4544 &iter_inform_super, &iter_clear, &iter_get_mem 4545 }; 4546 4547 struct module_func_block* 4548 iter_get_funcblock(void) 4549 { 4550 return &iter_block; 4551 } 4552 4553 const char* 4554 iter_state_to_string(enum iter_state state) 4555 { 4556 switch (state) 4557 { 4558 case INIT_REQUEST_STATE : 4559 return "INIT REQUEST STATE"; 4560 case INIT_REQUEST_2_STATE : 4561 return "INIT REQUEST STATE (stage 2)"; 4562 case INIT_REQUEST_3_STATE: 4563 return "INIT REQUEST STATE (stage 3)"; 4564 case QUERYTARGETS_STATE : 4565 return "QUERY TARGETS STATE"; 4566 case PRIME_RESP_STATE : 4567 return "PRIME RESPONSE STATE"; 4568 case COLLECT_CLASS_STATE : 4569 return "COLLECT CLASS STATE"; 4570 case DSNS_FIND_STATE : 4571 return "DSNS FIND STATE"; 4572 case QUERY_RESP_STATE : 4573 return "QUERY RESPONSE STATE"; 4574 case FINISHED_STATE : 4575 return "FINISHED RESPONSE STATE"; 4576 default : 4577 return "UNKNOWN ITER STATE"; 4578 } 4579 } 4580 4581 int 4582 iter_state_is_responsestate(enum iter_state s) 4583 { 4584 switch(s) { 4585 case INIT_REQUEST_STATE : 4586 case INIT_REQUEST_2_STATE : 4587 case INIT_REQUEST_3_STATE : 4588 case QUERYTARGETS_STATE : 4589 case COLLECT_CLASS_STATE : 4590 return 0; 4591 default: 4592 break; 4593 } 4594 return 1; 4595 } 4596