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