1238106Sdes/* 2238106Sdes * iterator/iterator.c - iterative resolver DNS query response module 3238106Sdes * 4238106Sdes * Copyright (c) 2007, NLnet Labs. All rights reserved. 5238106Sdes * 6238106Sdes * This software is open source. 7238106Sdes * 8238106Sdes * Redistribution and use in source and binary forms, with or without 9238106Sdes * modification, are permitted provided that the following conditions 10238106Sdes * are met: 11238106Sdes * 12238106Sdes * Redistributions of source code must retain the above copyright notice, 13238106Sdes * this list of conditions and the following disclaimer. 14238106Sdes * 15238106Sdes * Redistributions in binary form must reproduce the above copyright notice, 16238106Sdes * this list of conditions and the following disclaimer in the documentation 17238106Sdes * and/or other materials provided with the distribution. 18238106Sdes * 19238106Sdes * Neither the name of the NLNET LABS nor the names of its contributors may 20238106Sdes * be used to endorse or promote products derived from this software without 21238106Sdes * specific prior written permission. 22238106Sdes * 23238106Sdes * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24269257Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25269257Sdes * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26269257Sdes * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27269257Sdes * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28269257Sdes * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29269257Sdes * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30269257Sdes * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31269257Sdes * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32269257Sdes * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33269257Sdes * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34238106Sdes */ 35238106Sdes 36238106Sdes/** 37238106Sdes * \file 38238106Sdes * 39238106Sdes * This file contains a module that performs recusive iterative DNS query 40238106Sdes * processing. 41238106Sdes */ 42238106Sdes 43238106Sdes#include "config.h" 44238106Sdes#include "iterator/iterator.h" 45238106Sdes#include "iterator/iter_utils.h" 46238106Sdes#include "iterator/iter_hints.h" 47238106Sdes#include "iterator/iter_fwd.h" 48238106Sdes#include "iterator/iter_donotq.h" 49238106Sdes#include "iterator/iter_delegpt.h" 50238106Sdes#include "iterator/iter_resptype.h" 51238106Sdes#include "iterator/iter_scrub.h" 52238106Sdes#include "iterator/iter_priv.h" 53238106Sdes#include "validator/val_neg.h" 54238106Sdes#include "services/cache/dns.h" 55238106Sdes#include "services/cache/infra.h" 56238106Sdes#include "util/module.h" 57238106Sdes#include "util/netevent.h" 58238106Sdes#include "util/net_help.h" 59238106Sdes#include "util/regional.h" 60238106Sdes#include "util/data/dname.h" 61238106Sdes#include "util/data/msgencode.h" 62238106Sdes#include "util/fptr_wlist.h" 63238106Sdes#include "util/config_file.h" 64269257Sdes#include "ldns/rrdef.h" 65269257Sdes#include "ldns/wire2str.h" 66269257Sdes#include "ldns/parseutil.h" 67269257Sdes#include "ldns/sbuffer.h" 68238106Sdes 69238106Sdesint 70238106Sdesiter_init(struct module_env* env, int id) 71238106Sdes{ 72238106Sdes struct iter_env* iter_env = (struct iter_env*)calloc(1, 73238106Sdes sizeof(struct iter_env)); 74238106Sdes if(!iter_env) { 75238106Sdes log_err("malloc failure"); 76238106Sdes return 0; 77238106Sdes } 78238106Sdes env->modinfo[id] = (void*)iter_env; 79238106Sdes if(!iter_apply_cfg(iter_env, env->cfg)) { 80238106Sdes log_err("iterator: could not apply configuration settings."); 81238106Sdes return 0; 82238106Sdes } 83238106Sdes return 1; 84238106Sdes} 85238106Sdes 86238106Sdesvoid 87238106Sdesiter_deinit(struct module_env* env, int id) 88238106Sdes{ 89238106Sdes struct iter_env* iter_env; 90238106Sdes if(!env || !env->modinfo[id]) 91238106Sdes return; 92238106Sdes iter_env = (struct iter_env*)env->modinfo[id]; 93238106Sdes free(iter_env->target_fetch_policy); 94238106Sdes priv_delete(iter_env->priv); 95238106Sdes donotq_delete(iter_env->donotq); 96238106Sdes free(iter_env); 97238106Sdes env->modinfo[id] = NULL; 98238106Sdes} 99238106Sdes 100238106Sdes/** new query for iterator */ 101238106Sdesstatic int 102238106Sdesiter_new(struct module_qstate* qstate, int id) 103238106Sdes{ 104238106Sdes struct iter_qstate* iq = (struct iter_qstate*)regional_alloc( 105238106Sdes qstate->region, sizeof(struct iter_qstate)); 106238106Sdes qstate->minfo[id] = iq; 107238106Sdes if(!iq) 108238106Sdes return 0; 109238106Sdes memset(iq, 0, sizeof(*iq)); 110238106Sdes iq->state = INIT_REQUEST_STATE; 111238106Sdes iq->final_state = FINISHED_STATE; 112238106Sdes iq->an_prepend_list = NULL; 113238106Sdes iq->an_prepend_last = NULL; 114238106Sdes iq->ns_prepend_list = NULL; 115238106Sdes iq->ns_prepend_last = NULL; 116238106Sdes iq->dp = NULL; 117238106Sdes iq->depth = 0; 118238106Sdes iq->num_target_queries = 0; 119238106Sdes iq->num_current_queries = 0; 120238106Sdes iq->query_restart_count = 0; 121238106Sdes iq->referral_count = 0; 122238106Sdes iq->sent_count = 0; 123275854Sdelphij iq->target_count = NULL; 124238106Sdes iq->wait_priming_stub = 0; 125238106Sdes iq->refetch_glue = 0; 126238106Sdes iq->dnssec_expected = 0; 127238106Sdes iq->dnssec_lame_query = 0; 128238106Sdes iq->chase_flags = qstate->query_flags; 129238106Sdes /* Start with the (current) qname. */ 130238106Sdes iq->qchase = qstate->qinfo; 131238106Sdes outbound_list_init(&iq->outlist); 132238106Sdes return 1; 133238106Sdes} 134238106Sdes 135238106Sdes/** 136238106Sdes * Transition to the next state. This can be used to advance a currently 137238106Sdes * processing event. It cannot be used to reactivate a forEvent. 138238106Sdes * 139238106Sdes * @param iq: iterator query state 140238106Sdes * @param nextstate The state to transition to. 141238106Sdes * @return true. This is so this can be called as the return value for the 142238106Sdes * actual process*State() methods. (Transitioning to the next state 143238106Sdes * implies further processing). 144238106Sdes */ 145238106Sdesstatic int 146238106Sdesnext_state(struct iter_qstate* iq, enum iter_state nextstate) 147238106Sdes{ 148238106Sdes /* If transitioning to a "response" state, make sure that there is a 149238106Sdes * response */ 150238106Sdes if(iter_state_is_responsestate(nextstate)) { 151238106Sdes if(iq->response == NULL) { 152238106Sdes log_err("transitioning to response state sans " 153238106Sdes "response."); 154238106Sdes } 155238106Sdes } 156238106Sdes iq->state = nextstate; 157238106Sdes return 1; 158238106Sdes} 159238106Sdes 160238106Sdes/** 161238106Sdes * Transition an event to its final state. Final states always either return 162238106Sdes * a result up the module chain, or reactivate a dependent event. Which 163238106Sdes * final state to transtion to is set in the module state for the event when 164238106Sdes * it was created, and depends on the original purpose of the event. 165238106Sdes * 166238106Sdes * The response is stored in the qstate->buf buffer. 167238106Sdes * 168238106Sdes * @param iq: iterator query state 169238106Sdes * @return false. This is so this method can be used as the return value for 170238106Sdes * the processState methods. (Transitioning to the final state 171238106Sdes */ 172238106Sdesstatic int 173238106Sdesfinal_state(struct iter_qstate* iq) 174238106Sdes{ 175238106Sdes return next_state(iq, iq->final_state); 176238106Sdes} 177238106Sdes 178238106Sdes/** 179238106Sdes * Callback routine to handle errors in parent query states 180238106Sdes * @param qstate: query state that failed. 181238106Sdes * @param id: module id. 182238106Sdes * @param super: super state. 183238106Sdes */ 184238106Sdesstatic void 185238106Sdeserror_supers(struct module_qstate* qstate, int id, struct module_qstate* super) 186238106Sdes{ 187238106Sdes struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; 188238106Sdes 189238106Sdes if(qstate->qinfo.qtype == LDNS_RR_TYPE_A || 190238106Sdes qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) { 191238106Sdes /* mark address as failed. */ 192238106Sdes struct delegpt_ns* dpns = NULL; 193238106Sdes if(super_iq->dp) 194238106Sdes dpns = delegpt_find_ns(super_iq->dp, 195238106Sdes qstate->qinfo.qname, qstate->qinfo.qname_len); 196238106Sdes if(!dpns) { 197238106Sdes /* not interested */ 198238106Sdes verbose(VERB_ALGO, "subq error, but not interested"); 199238106Sdes log_query_info(VERB_ALGO, "superq", &super->qinfo); 200238106Sdes if(super_iq->dp) 201238106Sdes delegpt_log(VERB_ALGO, super_iq->dp); 202238106Sdes log_assert(0); 203238106Sdes return; 204238106Sdes } else { 205238106Sdes /* see if the failure did get (parent-lame) info */ 206238106Sdes if(!cache_fill_missing(super->env, 207238106Sdes super_iq->qchase.qclass, super->region, 208238106Sdes super_iq->dp)) 209238106Sdes log_err("out of memory adding missing"); 210238106Sdes } 211238106Sdes dpns->resolved = 1; /* mark as failed */ 212238106Sdes super_iq->num_target_queries--; 213238106Sdes } 214238106Sdes if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) { 215238106Sdes /* prime failed to get delegation */ 216238106Sdes super_iq->dp = NULL; 217238106Sdes } 218238106Sdes /* evaluate targets again */ 219238106Sdes super_iq->state = QUERYTARGETS_STATE; 220238106Sdes /* super becomes runnable, and will process this change */ 221238106Sdes} 222238106Sdes 223238106Sdes/** 224238106Sdes * Return an error to the client 225238106Sdes * @param qstate: our query state 226238106Sdes * @param id: module id 227238106Sdes * @param rcode: error code (DNS errcode). 228238106Sdes * @return: 0 for use by caller, to make notation easy, like: 229238106Sdes * return error_response(..). 230238106Sdes */ 231238106Sdesstatic int 232238106Sdeserror_response(struct module_qstate* qstate, int id, int rcode) 233238106Sdes{ 234238106Sdes verbose(VERB_QUERY, "return error response %s", 235269257Sdes sldns_lookup_by_id(sldns_rcodes, rcode)? 236269257Sdes sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??"); 237238106Sdes qstate->return_rcode = rcode; 238238106Sdes qstate->return_msg = NULL; 239238106Sdes qstate->ext_state[id] = module_finished; 240238106Sdes return 0; 241238106Sdes} 242238106Sdes 243238106Sdes/** 244238106Sdes * Return an error to the client and cache the error code in the 245238106Sdes * message cache (so per qname, qtype, qclass). 246238106Sdes * @param qstate: our query state 247238106Sdes * @param id: module id 248238106Sdes * @param rcode: error code (DNS errcode). 249238106Sdes * @return: 0 for use by caller, to make notation easy, like: 250238106Sdes * return error_response(..). 251238106Sdes */ 252238106Sdesstatic int 253238106Sdeserror_response_cache(struct module_qstate* qstate, int id, int rcode) 254238106Sdes{ 255238106Sdes /* store in cache */ 256238106Sdes struct reply_info err; 257238106Sdes memset(&err, 0, sizeof(err)); 258238106Sdes err.flags = (uint16_t)(BIT_QR | BIT_RA); 259238106Sdes FLAGS_SET_RCODE(err.flags, rcode); 260238106Sdes err.qdcount = 1; 261238106Sdes err.ttl = NORR_TTL; 262238106Sdes err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl); 263238106Sdes /* do not waste time trying to validate this servfail */ 264238106Sdes err.security = sec_status_indeterminate; 265238106Sdes verbose(VERB_ALGO, "store error response in message cache"); 266249141Sdes iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL); 267238106Sdes return error_response(qstate, id, rcode); 268238106Sdes} 269238106Sdes 270238106Sdes/** check if prepend item is duplicate item */ 271238106Sdesstatic int 272238106Sdesprepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to, 273238106Sdes struct ub_packed_rrset_key* dup) 274238106Sdes{ 275238106Sdes size_t i; 276238106Sdes for(i=0; i<to; i++) { 277238106Sdes if(sets[i]->rk.type == dup->rk.type && 278238106Sdes sets[i]->rk.rrset_class == dup->rk.rrset_class && 279238106Sdes sets[i]->rk.dname_len == dup->rk.dname_len && 280238106Sdes query_dname_compare(sets[i]->rk.dname, dup->rk.dname) 281238106Sdes == 0) 282238106Sdes return 1; 283238106Sdes } 284238106Sdes return 0; 285238106Sdes} 286238106Sdes 287238106Sdes/** prepend the prepend list in the answer and authority section of dns_msg */ 288238106Sdesstatic int 289238106Sdesiter_prepend(struct iter_qstate* iq, struct dns_msg* msg, 290238106Sdes struct regional* region) 291238106Sdes{ 292238106Sdes struct iter_prep_list* p; 293238106Sdes struct ub_packed_rrset_key** sets; 294238106Sdes size_t num_an = 0, num_ns = 0;; 295238106Sdes for(p = iq->an_prepend_list; p; p = p->next) 296238106Sdes num_an++; 297238106Sdes for(p = iq->ns_prepend_list; p; p = p->next) 298238106Sdes num_ns++; 299238106Sdes if(num_an + num_ns == 0) 300238106Sdes return 1; 301238106Sdes verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns); 302238106Sdes sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) * 303238106Sdes sizeof(struct ub_packed_rrset_key*)); 304238106Sdes if(!sets) 305238106Sdes return 0; 306238106Sdes /* ANSWER section */ 307238106Sdes num_an = 0; 308238106Sdes for(p = iq->an_prepend_list; p; p = p->next) { 309238106Sdes sets[num_an++] = p->rrset; 310238106Sdes } 311238106Sdes memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets * 312238106Sdes sizeof(struct ub_packed_rrset_key*)); 313238106Sdes /* AUTH section */ 314238106Sdes num_ns = 0; 315238106Sdes for(p = iq->ns_prepend_list; p; p = p->next) { 316238106Sdes if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an, 317238106Sdes num_ns, p->rrset) || prepend_is_duplicate( 318238106Sdes msg->rep->rrsets+msg->rep->an_numrrsets, 319238106Sdes msg->rep->ns_numrrsets, p->rrset)) 320238106Sdes continue; 321238106Sdes sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset; 322238106Sdes } 323238106Sdes memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns, 324238106Sdes msg->rep->rrsets + msg->rep->an_numrrsets, 325238106Sdes (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) * 326238106Sdes sizeof(struct ub_packed_rrset_key*)); 327238106Sdes 328238106Sdes /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because 329238106Sdes * this is what recursors should give. */ 330238106Sdes msg->rep->rrset_count += num_an + num_ns; 331238106Sdes msg->rep->an_numrrsets += num_an; 332238106Sdes msg->rep->ns_numrrsets += num_ns; 333238106Sdes msg->rep->rrsets = sets; 334238106Sdes return 1; 335238106Sdes} 336238106Sdes 337238106Sdes/** 338238106Sdes * Add rrset to ANSWER prepend list 339238106Sdes * @param qstate: query state. 340238106Sdes * @param iq: iterator query state. 341238106Sdes * @param rrset: rrset to add. 342238106Sdes * @return false on failure (malloc). 343238106Sdes */ 344238106Sdesstatic int 345238106Sdesiter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq, 346238106Sdes struct ub_packed_rrset_key* rrset) 347238106Sdes{ 348238106Sdes struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 349238106Sdes qstate->region, sizeof(struct iter_prep_list)); 350238106Sdes if(!p) 351238106Sdes return 0; 352238106Sdes p->rrset = rrset; 353238106Sdes p->next = NULL; 354238106Sdes /* add at end */ 355238106Sdes if(iq->an_prepend_last) 356238106Sdes iq->an_prepend_last->next = p; 357238106Sdes else iq->an_prepend_list = p; 358238106Sdes iq->an_prepend_last = p; 359238106Sdes return 1; 360238106Sdes} 361238106Sdes 362238106Sdes/** 363238106Sdes * Add rrset to AUTHORITY prepend list 364238106Sdes * @param qstate: query state. 365238106Sdes * @param iq: iterator query state. 366238106Sdes * @param rrset: rrset to add. 367238106Sdes * @return false on failure (malloc). 368238106Sdes */ 369238106Sdesstatic int 370238106Sdesiter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq, 371238106Sdes struct ub_packed_rrset_key* rrset) 372238106Sdes{ 373238106Sdes struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc( 374238106Sdes qstate->region, sizeof(struct iter_prep_list)); 375238106Sdes if(!p) 376238106Sdes return 0; 377238106Sdes p->rrset = rrset; 378238106Sdes p->next = NULL; 379238106Sdes /* add at end */ 380238106Sdes if(iq->ns_prepend_last) 381238106Sdes iq->ns_prepend_last->next = p; 382238106Sdes else iq->ns_prepend_list = p; 383238106Sdes iq->ns_prepend_last = p; 384238106Sdes return 1; 385238106Sdes} 386238106Sdes 387238106Sdes/** 388238106Sdes * Given a CNAME response (defined as a response containing a CNAME or DNAME 389238106Sdes * that does not answer the request), process the response, modifying the 390238106Sdes * state as necessary. This follows the CNAME/DNAME chain and returns the 391238106Sdes * final query name. 392238106Sdes * 393238106Sdes * sets the new query name, after following the CNAME/DNAME chain. 394238106Sdes * @param qstate: query state. 395238106Sdes * @param iq: iterator query state. 396238106Sdes * @param msg: the response. 397238106Sdes * @param mname: returned target new query name. 398238106Sdes * @param mname_len: length of mname. 399238106Sdes * @return false on (malloc) error. 400238106Sdes */ 401238106Sdesstatic int 402238106Sdeshandle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq, 403238106Sdes struct dns_msg* msg, uint8_t** mname, size_t* mname_len) 404238106Sdes{ 405238106Sdes size_t i; 406238106Sdes /* Start with the (current) qname. */ 407238106Sdes *mname = iq->qchase.qname; 408238106Sdes *mname_len = iq->qchase.qname_len; 409238106Sdes 410238106Sdes /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and 411238106Sdes * DNAMES. */ 412238106Sdes for(i=0; i<msg->rep->an_numrrsets; i++) { 413238106Sdes struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 414238106Sdes /* If there is a (relevant) DNAME, add it to the list. 415238106Sdes * We always expect there to be CNAME that was generated 416238106Sdes * by this DNAME following, so we don't process the DNAME 417238106Sdes * directly. */ 418238106Sdes if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME && 419238106Sdes dname_strict_subdomain_c(*mname, r->rk.dname)) { 420238106Sdes if(!iter_add_prepend_answer(qstate, iq, r)) 421238106Sdes return 0; 422238106Sdes continue; 423238106Sdes } 424238106Sdes 425238106Sdes if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME && 426238106Sdes query_dname_compare(*mname, r->rk.dname) == 0) { 427238106Sdes /* Add this relevant CNAME rrset to the prepend list.*/ 428238106Sdes if(!iter_add_prepend_answer(qstate, iq, r)) 429238106Sdes return 0; 430238106Sdes get_cname_target(r, mname, mname_len); 431238106Sdes } 432238106Sdes 433238106Sdes /* Other rrsets in the section are ignored. */ 434238106Sdes } 435238106Sdes /* add authority rrsets to authority prepend, for wildcarded CNAMEs */ 436238106Sdes for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets + 437238106Sdes msg->rep->ns_numrrsets; i++) { 438238106Sdes struct ub_packed_rrset_key* r = msg->rep->rrsets[i]; 439238106Sdes /* only add NSEC/NSEC3, as they may be needed for validation */ 440238106Sdes if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC || 441238106Sdes ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) { 442238106Sdes if(!iter_add_prepend_auth(qstate, iq, r)) 443238106Sdes return 0; 444238106Sdes } 445238106Sdes } 446238106Sdes return 1; 447238106Sdes} 448238106Sdes 449275854Sdelphij/** create target count structure for this query */ 450275854Sdelphijstatic void 451275854Sdelphijtarget_count_create(struct iter_qstate* iq) 452275854Sdelphij{ 453275854Sdelphij if(!iq->target_count) { 454275854Sdelphij iq->target_count = (int*)calloc(2, sizeof(int)); 455275854Sdelphij /* if calloc fails we simply do not track this number */ 456275854Sdelphij if(iq->target_count) 457275854Sdelphij iq->target_count[0] = 1; 458275854Sdelphij } 459275854Sdelphij} 460275854Sdelphij 461275854Sdelphijstatic void 462275854Sdelphijtarget_count_increase(struct iter_qstate* iq, int num) 463275854Sdelphij{ 464275854Sdelphij target_count_create(iq); 465275854Sdelphij if(iq->target_count) 466275854Sdelphij iq->target_count[1] += num; 467275854Sdelphij} 468275854Sdelphij 469238106Sdes/** 470238106Sdes * Generate a subrequest. 471238106Sdes * Generate a local request event. Local events are tied to this module, and 472238106Sdes * have a correponding (first tier) event that is waiting for this event to 473238106Sdes * resolve to continue. 474238106Sdes * 475238106Sdes * @param qname The query name for this request. 476238106Sdes * @param qnamelen length of qname 477238106Sdes * @param qtype The query type for this request. 478238106Sdes * @param qclass The query class for this request. 479238106Sdes * @param qstate The event that is generating this event. 480238106Sdes * @param id: module id. 481238106Sdes * @param iq: The iterator state that is generating this event. 482238106Sdes * @param initial_state The initial response state (normally this 483238106Sdes * is QUERY_RESP_STATE, unless it is known that the request won't 484238106Sdes * need iterative processing 485238106Sdes * @param finalstate The final state for the response to this request. 486238106Sdes * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does 487238106Sdes * not need initialisation. 488238106Sdes * @param v: if true, validation is done on the subquery. 489238106Sdes * @return false on error (malloc). 490238106Sdes */ 491238106Sdesstatic int 492238106Sdesgenerate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype, 493238106Sdes uint16_t qclass, struct module_qstate* qstate, int id, 494238106Sdes struct iter_qstate* iq, enum iter_state initial_state, 495238106Sdes enum iter_state finalstate, struct module_qstate** subq_ret, int v) 496238106Sdes{ 497238106Sdes struct module_qstate* subq = NULL; 498238106Sdes struct iter_qstate* subiq = NULL; 499238106Sdes uint16_t qflags = 0; /* OPCODE QUERY, no flags */ 500238106Sdes struct query_info qinf; 501238106Sdes int prime = (finalstate == PRIME_RESP_STATE)?1:0; 502238106Sdes qinf.qname = qname; 503238106Sdes qinf.qname_len = qnamelen; 504238106Sdes qinf.qtype = qtype; 505238106Sdes qinf.qclass = qclass; 506238106Sdes 507238106Sdes /* RD should be set only when sending the query back through the INIT 508238106Sdes * state. */ 509238106Sdes if(initial_state == INIT_REQUEST_STATE) 510238106Sdes qflags |= BIT_RD; 511238106Sdes /* We set the CD flag so we can send this through the "head" of 512238106Sdes * the resolution chain, which might have a validator. We are 513238106Sdes * uninterested in validating things not on the direct resolution 514238106Sdes * path. */ 515238106Sdes if(!v) 516238106Sdes qflags |= BIT_CD; 517238106Sdes 518238106Sdes /* attach subquery, lookup existing or make a new one */ 519238106Sdes fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub)); 520238106Sdes if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, &subq)) { 521238106Sdes return 0; 522238106Sdes } 523238106Sdes *subq_ret = subq; 524238106Sdes if(subq) { 525238106Sdes /* initialise the new subquery */ 526238106Sdes subq->curmod = id; 527238106Sdes subq->ext_state[id] = module_state_initial; 528238106Sdes subq->minfo[id] = regional_alloc(subq->region, 529238106Sdes sizeof(struct iter_qstate)); 530238106Sdes if(!subq->minfo[id]) { 531238106Sdes log_err("init subq: out of memory"); 532238106Sdes fptr_ok(fptr_whitelist_modenv_kill_sub( 533238106Sdes qstate->env->kill_sub)); 534238106Sdes (*qstate->env->kill_sub)(subq); 535238106Sdes return 0; 536238106Sdes } 537238106Sdes subiq = (struct iter_qstate*)subq->minfo[id]; 538238106Sdes memset(subiq, 0, sizeof(*subiq)); 539238106Sdes subiq->num_target_queries = 0; 540275854Sdelphij target_count_create(iq); 541275854Sdelphij subiq->target_count = iq->target_count; 542275854Sdelphij if(iq->target_count) 543275854Sdelphij iq->target_count[0] ++; /* extra reference */ 544238106Sdes subiq->num_current_queries = 0; 545238106Sdes subiq->depth = iq->depth+1; 546238106Sdes outbound_list_init(&subiq->outlist); 547238106Sdes subiq->state = initial_state; 548238106Sdes subiq->final_state = finalstate; 549238106Sdes subiq->qchase = subq->qinfo; 550238106Sdes subiq->chase_flags = subq->query_flags; 551238106Sdes subiq->refetch_glue = 0; 552238106Sdes } 553238106Sdes return 1; 554238106Sdes} 555238106Sdes 556238106Sdes/** 557238106Sdes * Generate and send a root priming request. 558238106Sdes * @param qstate: the qtstate that triggered the need to prime. 559238106Sdes * @param iq: iterator query state. 560238106Sdes * @param id: module id. 561238106Sdes * @param qclass: the class to prime. 562238106Sdes * @return 0 on failure 563238106Sdes */ 564238106Sdesstatic int 565238106Sdesprime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id, 566238106Sdes uint16_t qclass) 567238106Sdes{ 568238106Sdes struct delegpt* dp; 569238106Sdes struct module_qstate* subq; 570238106Sdes verbose(VERB_DETAIL, "priming . %s NS", 571269257Sdes sldns_lookup_by_id(sldns_rr_classes, (int)qclass)? 572269257Sdes sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??"); 573238106Sdes dp = hints_lookup_root(qstate->env->hints, qclass); 574238106Sdes if(!dp) { 575238106Sdes verbose(VERB_ALGO, "Cannot prime due to lack of hints"); 576238106Sdes return 0; 577238106Sdes } 578238106Sdes /* Priming requests start at the QUERYTARGETS state, skipping 579238106Sdes * the normal INIT state logic (which would cause an infloop). */ 580238106Sdes if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS, 581238106Sdes qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE, 582238106Sdes &subq, 0)) { 583238106Sdes verbose(VERB_ALGO, "could not prime root"); 584238106Sdes return 0; 585238106Sdes } 586238106Sdes if(subq) { 587238106Sdes struct iter_qstate* subiq = 588238106Sdes (struct iter_qstate*)subq->minfo[id]; 589238106Sdes /* Set the initial delegation point to the hint. 590238106Sdes * copy dp, it is now part of the root prime query. 591238106Sdes * dp was part of in the fixed hints structure. */ 592238106Sdes subiq->dp = delegpt_copy(dp, subq->region); 593238106Sdes if(!subiq->dp) { 594238106Sdes log_err("out of memory priming root, copydp"); 595238106Sdes fptr_ok(fptr_whitelist_modenv_kill_sub( 596238106Sdes qstate->env->kill_sub)); 597238106Sdes (*qstate->env->kill_sub)(subq); 598238106Sdes return 0; 599238106Sdes } 600238106Sdes /* there should not be any target queries. */ 601238106Sdes subiq->num_target_queries = 0; 602238106Sdes subiq->dnssec_expected = iter_indicates_dnssec( 603238106Sdes qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 604238106Sdes } 605238106Sdes 606238106Sdes /* this module stops, our submodule starts, and does the query. */ 607238106Sdes qstate->ext_state[id] = module_wait_subquery; 608238106Sdes return 1; 609238106Sdes} 610238106Sdes 611238106Sdes/** 612238106Sdes * Generate and process a stub priming request. This method tests for the 613238106Sdes * need to prime a stub zone, so it is safe to call for every request. 614238106Sdes * 615238106Sdes * @param qstate: the qtstate that triggered the need to prime. 616238106Sdes * @param iq: iterator query state. 617238106Sdes * @param id: module id. 618238106Sdes * @param qname: request name. 619238106Sdes * @param qclass: request class. 620238106Sdes * @return true if a priming subrequest was made, false if not. The will only 621238106Sdes * issue a priming request if it detects an unprimed stub. 622238106Sdes * Uses value of 2 to signal during stub-prime in root-prime situation 623238106Sdes * that a noprime-stub is available and resolution can continue. 624238106Sdes */ 625238106Sdesstatic int 626238106Sdesprime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id, 627238106Sdes uint8_t* qname, uint16_t qclass) 628238106Sdes{ 629238106Sdes /* Lookup the stub hint. This will return null if the stub doesn't 630238106Sdes * need to be re-primed. */ 631238106Sdes struct iter_hints_stub* stub; 632238106Sdes struct delegpt* stub_dp; 633238106Sdes struct module_qstate* subq; 634238106Sdes 635238106Sdes if(!qname) return 0; 636238106Sdes stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp); 637238106Sdes /* The stub (if there is one) does not need priming. */ 638238106Sdes if(!stub) 639238106Sdes return 0; 640238106Sdes stub_dp = stub->dp; 641238106Sdes 642238106Sdes /* is it a noprime stub (always use) */ 643238106Sdes if(stub->noprime) { 644238106Sdes int r = 0; 645238106Sdes if(iq->dp == NULL) r = 2; 646238106Sdes /* copy the dp out of the fixed hints structure, so that 647238106Sdes * it can be changed when servicing this query */ 648238106Sdes iq->dp = delegpt_copy(stub_dp, qstate->region); 649238106Sdes if(!iq->dp) { 650238106Sdes log_err("out of memory priming stub"); 651238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 652238106Sdes return 1; /* return 1 to make module stop, with error */ 653238106Sdes } 654238106Sdes log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name, 655238106Sdes LDNS_RR_TYPE_NS, qclass); 656238106Sdes return r; 657238106Sdes } 658238106Sdes 659238106Sdes /* Otherwise, we need to (re)prime the stub. */ 660238106Sdes log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name, 661238106Sdes LDNS_RR_TYPE_NS, qclass); 662238106Sdes 663238106Sdes /* Stub priming events start at the QUERYTARGETS state to avoid the 664238106Sdes * redundant INIT state processing. */ 665238106Sdes if(!generate_sub_request(stub_dp->name, stub_dp->namelen, 666238106Sdes LDNS_RR_TYPE_NS, qclass, qstate, id, iq, 667238106Sdes QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) { 668238106Sdes verbose(VERB_ALGO, "could not prime stub"); 669238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 670238106Sdes return 1; /* return 1 to make module stop, with error */ 671238106Sdes } 672238106Sdes if(subq) { 673238106Sdes struct iter_qstate* subiq = 674238106Sdes (struct iter_qstate*)subq->minfo[id]; 675238106Sdes 676238106Sdes /* Set the initial delegation point to the hint. */ 677238106Sdes /* make copy to avoid use of stub dp by different qs/threads */ 678238106Sdes subiq->dp = delegpt_copy(stub_dp, subq->region); 679238106Sdes if(!subiq->dp) { 680238106Sdes log_err("out of memory priming stub, copydp"); 681238106Sdes fptr_ok(fptr_whitelist_modenv_kill_sub( 682238106Sdes qstate->env->kill_sub)); 683238106Sdes (*qstate->env->kill_sub)(subq); 684238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 685238106Sdes return 1; /* return 1 to make module stop, with error */ 686238106Sdes } 687238106Sdes /* there should not be any target queries -- although there 688238106Sdes * wouldn't be anyway, since stub hints never have 689238106Sdes * missing targets. */ 690238106Sdes subiq->num_target_queries = 0; 691238106Sdes subiq->wait_priming_stub = 1; 692238106Sdes subiq->dnssec_expected = iter_indicates_dnssec( 693238106Sdes qstate->env, subiq->dp, NULL, subq->qinfo.qclass); 694238106Sdes } 695238106Sdes 696238106Sdes /* this module stops, our submodule starts, and does the query. */ 697238106Sdes qstate->ext_state[id] = module_wait_subquery; 698238106Sdes return 1; 699238106Sdes} 700238106Sdes 701238106Sdes/** 702238106Sdes * Generate A and AAAA checks for glue that is in-zone for the referral 703238106Sdes * we just got to obtain authoritative information on the adresses. 704238106Sdes * 705238106Sdes * @param qstate: the qtstate that triggered the need to prime. 706238106Sdes * @param iq: iterator query state. 707238106Sdes * @param id: module id. 708238106Sdes */ 709238106Sdesstatic void 710238106Sdesgenerate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq, 711238106Sdes int id) 712238106Sdes{ 713238106Sdes struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 714238106Sdes struct module_qstate* subq; 715238106Sdes size_t i; 716238106Sdes struct reply_info* rep = iq->response->rep; 717238106Sdes struct ub_packed_rrset_key* s; 718238106Sdes log_assert(iq->dp); 719238106Sdes 720238106Sdes if(iq->depth == ie->max_dependency_depth) 721238106Sdes return; 722238106Sdes /* walk through additional, and check if in-zone, 723238106Sdes * only relevant A, AAAA are left after scrub anyway */ 724238106Sdes for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) { 725238106Sdes s = rep->rrsets[i]; 726238106Sdes /* check *ALL* addresses that are transmitted in additional*/ 727238106Sdes /* is it an address ? */ 728238106Sdes if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A || 729238106Sdes ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) { 730238106Sdes continue; 731238106Sdes } 732238106Sdes /* is this query the same as the A/AAAA check for it */ 733238106Sdes if(qstate->qinfo.qtype == ntohs(s->rk.type) && 734238106Sdes qstate->qinfo.qclass == ntohs(s->rk.rrset_class) && 735238106Sdes query_dname_compare(qstate->qinfo.qname, 736238106Sdes s->rk.dname)==0 && 737238106Sdes (qstate->query_flags&BIT_RD) && 738238106Sdes !(qstate->query_flags&BIT_CD)) 739238106Sdes continue; 740238106Sdes 741238106Sdes /* generate subrequest for it */ 742238106Sdes log_nametypeclass(VERB_ALGO, "schedule addr fetch", 743238106Sdes s->rk.dname, ntohs(s->rk.type), 744238106Sdes ntohs(s->rk.rrset_class)); 745238106Sdes if(!generate_sub_request(s->rk.dname, s->rk.dname_len, 746238106Sdes ntohs(s->rk.type), ntohs(s->rk.rrset_class), 747238106Sdes qstate, id, iq, 748238106Sdes INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 749238106Sdes verbose(VERB_ALGO, "could not generate addr check"); 750238106Sdes return; 751238106Sdes } 752238106Sdes /* ignore subq - not need for more init */ 753238106Sdes } 754238106Sdes} 755238106Sdes 756238106Sdes/** 757238106Sdes * Generate a NS check request to obtain authoritative information 758238106Sdes * on an NS rrset. 759238106Sdes * 760238106Sdes * @param qstate: the qtstate that triggered the need to prime. 761238106Sdes * @param iq: iterator query state. 762238106Sdes * @param id: module id. 763238106Sdes */ 764238106Sdesstatic void 765238106Sdesgenerate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id) 766238106Sdes{ 767238106Sdes struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 768238106Sdes struct module_qstate* subq; 769238106Sdes log_assert(iq->dp); 770238106Sdes 771238106Sdes if(iq->depth == ie->max_dependency_depth) 772238106Sdes return; 773238106Sdes /* is this query the same as the nscheck? */ 774238106Sdes if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS && 775238106Sdes query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 776238106Sdes (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 777238106Sdes /* spawn off A, AAAA queries for in-zone glue to check */ 778238106Sdes generate_a_aaaa_check(qstate, iq, id); 779238106Sdes return; 780238106Sdes } 781238106Sdes 782238106Sdes log_nametypeclass(VERB_ALGO, "schedule ns fetch", 783238106Sdes iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass); 784238106Sdes if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 785238106Sdes LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 786238106Sdes INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 787238106Sdes verbose(VERB_ALGO, "could not generate ns check"); 788238106Sdes return; 789238106Sdes } 790238106Sdes if(subq) { 791238106Sdes struct iter_qstate* subiq = 792238106Sdes (struct iter_qstate*)subq->minfo[id]; 793238106Sdes 794238106Sdes /* make copy to avoid use of stub dp by different qs/threads */ 795238106Sdes /* refetch glue to start higher up the tree */ 796238106Sdes subiq->refetch_glue = 1; 797238106Sdes subiq->dp = delegpt_copy(iq->dp, subq->region); 798238106Sdes if(!subiq->dp) { 799238106Sdes log_err("out of memory generating ns check, copydp"); 800238106Sdes fptr_ok(fptr_whitelist_modenv_kill_sub( 801238106Sdes qstate->env->kill_sub)); 802238106Sdes (*qstate->env->kill_sub)(subq); 803238106Sdes return; 804238106Sdes } 805238106Sdes } 806238106Sdes} 807238106Sdes 808238106Sdes/** 809238106Sdes * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we 810238106Sdes * just got in a referral (where we have dnssec_expected, thus have trust 811238106Sdes * anchors above it). Note that right after calling this routine the 812238106Sdes * iterator detached subqueries (because of following the referral), and thus 813238106Sdes * the DNSKEY query becomes detached, its return stored in the cache for 814238106Sdes * later lookup by the validator. This cache lookup by the validator avoids 815238106Sdes * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now 816238106Sdes * performed at about the same time the original query is sent to the domain, 817238106Sdes * thus the two answers are likely to be returned at about the same time, 818238106Sdes * saving a roundtrip from the validated lookup. 819238106Sdes * 820238106Sdes * @param qstate: the qtstate that triggered the need to prime. 821238106Sdes * @param iq: iterator query state. 822238106Sdes * @param id: module id. 823238106Sdes */ 824238106Sdesstatic void 825238106Sdesgenerate_dnskey_prefetch(struct module_qstate* qstate, 826238106Sdes struct iter_qstate* iq, int id) 827238106Sdes{ 828238106Sdes struct module_qstate* subq; 829238106Sdes log_assert(iq->dp); 830238106Sdes 831238106Sdes /* is this query the same as the prefetch? */ 832238106Sdes if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY && 833238106Sdes query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 && 834238106Sdes (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){ 835238106Sdes return; 836238106Sdes } 837238106Sdes 838238106Sdes /* if the DNSKEY is in the cache this lookup will stop quickly */ 839238106Sdes log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch", 840238106Sdes iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass); 841238106Sdes if(!generate_sub_request(iq->dp->name, iq->dp->namelen, 842238106Sdes LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq, 843238106Sdes INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 844238106Sdes /* we'll be slower, but it'll work */ 845238106Sdes verbose(VERB_ALGO, "could not generate dnskey prefetch"); 846238106Sdes return; 847238106Sdes } 848238106Sdes if(subq) { 849238106Sdes struct iter_qstate* subiq = 850238106Sdes (struct iter_qstate*)subq->minfo[id]; 851238106Sdes /* this qstate has the right delegation for the dnskey lookup*/ 852238106Sdes /* make copy to avoid use of stub dp by different qs/threads */ 853238106Sdes subiq->dp = delegpt_copy(iq->dp, subq->region); 854238106Sdes /* if !subiq->dp, it'll start from the cache, no problem */ 855238106Sdes } 856238106Sdes} 857238106Sdes 858238106Sdes/** 859238106Sdes * See if the query needs forwarding. 860238106Sdes * 861238106Sdes * @param qstate: query state. 862238106Sdes * @param iq: iterator query state. 863238106Sdes * @return true if the request is forwarded, false if not. 864238106Sdes * If returns true but, iq->dp is NULL then a malloc failure occurred. 865238106Sdes */ 866238106Sdesstatic int 867238106Sdesforward_request(struct module_qstate* qstate, struct iter_qstate* iq) 868238106Sdes{ 869238106Sdes struct delegpt* dp; 870238106Sdes uint8_t* delname = iq->qchase.qname; 871238106Sdes size_t delnamelen = iq->qchase.qname_len; 872238106Sdes if(iq->refetch_glue) { 873238106Sdes delname = iq->dp->name; 874238106Sdes delnamelen = iq->dp->namelen; 875238106Sdes } 876238106Sdes /* strip one label off of DS query to lookup higher for it */ 877238106Sdes if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) 878238106Sdes && !dname_is_root(iq->qchase.qname)) 879238106Sdes dname_remove_label(&delname, &delnamelen); 880238106Sdes dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass); 881238106Sdes if(!dp) 882238106Sdes return 0; 883238106Sdes /* send recursion desired to forward addr */ 884238106Sdes iq->chase_flags |= BIT_RD; 885238106Sdes iq->dp = delegpt_copy(dp, qstate->region); 886238106Sdes /* iq->dp checked by caller */ 887238106Sdes verbose(VERB_ALGO, "forwarding request"); 888238106Sdes return 1; 889238106Sdes} 890238106Sdes 891238106Sdes/** 892238106Sdes * Process the initial part of the request handling. This state roughly 893238106Sdes * corresponds to resolver algorithms steps 1 (find answer in cache) and 2 894238106Sdes * (find the best servers to ask). 895238106Sdes * 896238106Sdes * Note that all requests start here, and query restarts revisit this state. 897238106Sdes * 898238106Sdes * This state either generates: 1) a response, from cache or error, 2) a 899238106Sdes * priming event, or 3) forwards the request to the next state (init2, 900238106Sdes * generally). 901238106Sdes * 902238106Sdes * @param qstate: query state. 903238106Sdes * @param iq: iterator query state. 904238106Sdes * @param ie: iterator shared global environment. 905238106Sdes * @param id: module id. 906238106Sdes * @return true if the event needs more request processing immediately, 907238106Sdes * false if not. 908238106Sdes */ 909238106Sdesstatic int 910238106SdesprocessInitRequest(struct module_qstate* qstate, struct iter_qstate* iq, 911238106Sdes struct iter_env* ie, int id) 912238106Sdes{ 913238106Sdes uint8_t* delname; 914238106Sdes size_t delnamelen; 915238106Sdes struct dns_msg* msg; 916238106Sdes 917238106Sdes log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo); 918238106Sdes /* check effort */ 919238106Sdes 920238106Sdes /* We enforce a maximum number of query restarts. This is primarily a 921238106Sdes * cheap way to prevent CNAME loops. */ 922238106Sdes if(iq->query_restart_count > MAX_RESTART_COUNT) { 923238106Sdes verbose(VERB_QUERY, "request has exceeded the maximum number" 924238106Sdes " of query restarts with %d", iq->query_restart_count); 925238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 926238106Sdes } 927238106Sdes 928238106Sdes /* We enforce a maximum recursion/dependency depth -- in general, 929238106Sdes * this is unnecessary for dependency loops (although it will 930238106Sdes * catch those), but it provides a sensible limit to the amount 931238106Sdes * of work required to answer a given query. */ 932238106Sdes verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth); 933238106Sdes if(iq->depth > ie->max_dependency_depth) { 934238106Sdes verbose(VERB_QUERY, "request has exceeded the maximum " 935238106Sdes "dependency depth with depth of %d", iq->depth); 936238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 937238106Sdes } 938238106Sdes 939238106Sdes /* If the request is qclass=ANY, setup to generate each class */ 940238106Sdes if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) { 941238106Sdes iq->qchase.qclass = 0; 942238106Sdes return next_state(iq, COLLECT_CLASS_STATE); 943238106Sdes } 944238106Sdes 945238106Sdes /* Resolver Algorithm Step 1 -- Look for the answer in local data. */ 946238106Sdes 947238106Sdes /* This either results in a query restart (CNAME cache response), a 948238106Sdes * terminating response (ANSWER), or a cache miss (null). */ 949238106Sdes 950238106Sdes if(qstate->blacklist) { 951238106Sdes /* if cache, or anything else, was blacklisted then 952238106Sdes * getting older results from cache is a bad idea, no cache */ 953238106Sdes verbose(VERB_ALGO, "cache blacklisted, going to the network"); 954238106Sdes msg = NULL; 955238106Sdes } else { 956238106Sdes msg = dns_cache_lookup(qstate->env, iq->qchase.qname, 957238106Sdes iq->qchase.qname_len, iq->qchase.qtype, 958238106Sdes iq->qchase.qclass, qstate->region, qstate->env->scratch); 959238106Sdes if(!msg && qstate->env->neg_cache) { 960238106Sdes /* lookup in negative cache; may result in 961238106Sdes * NOERROR/NODATA or NXDOMAIN answers that need validation */ 962238106Sdes msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase, 963238106Sdes qstate->region, qstate->env->rrset_cache, 964238106Sdes qstate->env->scratch_buffer, 965238106Sdes *qstate->env->now, 1/*add SOA*/, NULL); 966238106Sdes } 967238106Sdes /* item taken from cache does not match our query name, thus 968238106Sdes * security needs to be re-examined later */ 969238106Sdes if(msg && query_dname_compare(qstate->qinfo.qname, 970238106Sdes iq->qchase.qname) != 0) 971238106Sdes msg->rep->security = sec_status_unchecked; 972238106Sdes } 973238106Sdes if(msg) { 974238106Sdes /* handle positive cache response */ 975238106Sdes enum response_type type = response_type_from_cache(msg, 976238106Sdes &iq->qchase); 977238106Sdes if(verbosity >= VERB_ALGO) { 978238106Sdes log_dns_msg("msg from cache lookup", &msg->qinfo, 979238106Sdes msg->rep); 980238106Sdes verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d", 981238106Sdes (int)msg->rep->ttl, 982238106Sdes (int)msg->rep->prefetch_ttl); 983238106Sdes } 984238106Sdes 985238106Sdes if(type == RESPONSE_TYPE_CNAME) { 986238106Sdes uint8_t* sname = 0; 987238106Sdes size_t slen = 0; 988238106Sdes verbose(VERB_ALGO, "returning CNAME response from " 989238106Sdes "cache"); 990238106Sdes if(!handle_cname_response(qstate, iq, msg, 991238106Sdes &sname, &slen)) 992238106Sdes return error_response(qstate, id, 993238106Sdes LDNS_RCODE_SERVFAIL); 994238106Sdes iq->qchase.qname = sname; 995238106Sdes iq->qchase.qname_len = slen; 996238106Sdes /* This *is* a query restart, even if it is a cheap 997238106Sdes * one. */ 998238106Sdes iq->dp = NULL; 999238106Sdes iq->refetch_glue = 0; 1000238106Sdes iq->query_restart_count++; 1001238106Sdes iq->sent_count = 0; 1002238106Sdes sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1003238106Sdes return next_state(iq, INIT_REQUEST_STATE); 1004238106Sdes } 1005238106Sdes 1006238106Sdes /* if from cache, NULL, else insert 'cache IP' len=0 */ 1007238106Sdes if(qstate->reply_origin) 1008238106Sdes sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1009238106Sdes /* it is an answer, response, to final state */ 1010238106Sdes verbose(VERB_ALGO, "returning answer from cache."); 1011238106Sdes iq->response = msg; 1012238106Sdes return final_state(iq); 1013238106Sdes } 1014238106Sdes 1015238106Sdes /* attempt to forward the request */ 1016238106Sdes if(forward_request(qstate, iq)) 1017238106Sdes { 1018238106Sdes if(!iq->dp) { 1019238106Sdes log_err("alloc failure for forward dp"); 1020238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1021238106Sdes } 1022238106Sdes iq->refetch_glue = 0; 1023238106Sdes /* the request has been forwarded. 1024238106Sdes * forwarded requests need to be immediately sent to the 1025238106Sdes * next state, QUERYTARGETS. */ 1026238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1027238106Sdes } 1028238106Sdes 1029238106Sdes /* Resolver Algorithm Step 2 -- find the "best" servers. */ 1030238106Sdes 1031238106Sdes /* first, adjust for DS queries. To avoid the grandparent problem, 1032238106Sdes * we just look for the closest set of server to the parent of qname. 1033238106Sdes * When re-fetching glue we also need to ask the parent. 1034238106Sdes */ 1035238106Sdes if(iq->refetch_glue) { 1036238106Sdes if(!iq->dp) { 1037238106Sdes log_err("internal or malloc fail: no dp for refetch"); 1038238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1039238106Sdes } 1040238106Sdes delname = iq->dp->name; 1041238106Sdes delnamelen = iq->dp->namelen; 1042238106Sdes } else { 1043238106Sdes delname = iq->qchase.qname; 1044238106Sdes delnamelen = iq->qchase.qname_len; 1045238106Sdes } 1046238106Sdes if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue || 1047238106Sdes (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) { 1048238106Sdes /* remove first label from delname, root goes to hints, 1049238106Sdes * but only to fetch glue, not for qtype=DS. */ 1050238106Sdes /* also when prefetching an NS record, fetch it again from 1051238106Sdes * its parent, just as if it expired, so that you do not 1052238106Sdes * get stuck on an older nameserver that gives old NSrecords */ 1053238106Sdes if(dname_is_root(delname) && (iq->refetch_glue || 1054238106Sdes (iq->qchase.qtype == LDNS_RR_TYPE_NS && 1055238106Sdes qstate->prefetch_leeway))) 1056238106Sdes delname = NULL; /* go to root priming */ 1057238106Sdes else dname_remove_label(&delname, &delnamelen); 1058238106Sdes } 1059238106Sdes /* delname is the name to lookup a delegation for. If NULL rootprime */ 1060238106Sdes while(1) { 1061238106Sdes 1062238106Sdes /* Lookup the delegation in the cache. If null, then the 1063238106Sdes * cache needs to be primed for the qclass. */ 1064238106Sdes if(delname) 1065238106Sdes iq->dp = dns_cache_find_delegation(qstate->env, delname, 1066238106Sdes delnamelen, iq->qchase.qtype, iq->qchase.qclass, 1067238106Sdes qstate->region, &iq->deleg_msg, 1068238106Sdes *qstate->env->now+qstate->prefetch_leeway); 1069238106Sdes else iq->dp = NULL; 1070238106Sdes 1071238106Sdes /* If the cache has returned nothing, then we have a 1072238106Sdes * root priming situation. */ 1073238106Sdes if(iq->dp == NULL) { 1074238106Sdes /* if there is a stub, then no root prime needed */ 1075238106Sdes int r = prime_stub(qstate, iq, id, delname, 1076238106Sdes iq->qchase.qclass); 1077238106Sdes if(r == 2) 1078238106Sdes break; /* got noprime-stub-zone, continue */ 1079238106Sdes else if(r) 1080238106Sdes return 0; /* stub prime request made */ 1081238106Sdes if(forwards_lookup_root(qstate->env->fwds, 1082238106Sdes iq->qchase.qclass)) { 1083238106Sdes /* forward zone root, no root prime needed */ 1084238106Sdes /* fill in some dp - safety belt */ 1085238106Sdes iq->dp = hints_lookup_root(qstate->env->hints, 1086238106Sdes iq->qchase.qclass); 1087238106Sdes if(!iq->dp) { 1088238106Sdes log_err("internal error: no hints dp"); 1089238106Sdes return error_response(qstate, id, 1090238106Sdes LDNS_RCODE_SERVFAIL); 1091238106Sdes } 1092238106Sdes iq->dp = delegpt_copy(iq->dp, qstate->region); 1093238106Sdes if(!iq->dp) { 1094238106Sdes log_err("out of memory in safety belt"); 1095238106Sdes return error_response(qstate, id, 1096238106Sdes LDNS_RCODE_SERVFAIL); 1097238106Sdes } 1098238106Sdes return next_state(iq, INIT_REQUEST_2_STATE); 1099238106Sdes } 1100238106Sdes /* Note that the result of this will set a new 1101238106Sdes * DelegationPoint based on the result of priming. */ 1102238106Sdes if(!prime_root(qstate, iq, id, iq->qchase.qclass)) 1103238106Sdes return error_response(qstate, id, 1104238106Sdes LDNS_RCODE_REFUSED); 1105238106Sdes 1106238106Sdes /* priming creates and sends a subordinate query, with 1107238106Sdes * this query as the parent. So further processing for 1108238106Sdes * this event will stop until reactivated by the 1109238106Sdes * results of priming. */ 1110238106Sdes return 0; 1111238106Sdes } 1112238106Sdes 1113238106Sdes /* see if this dp not useless. 1114238106Sdes * It is useless if: 1115238106Sdes * o all NS items are required glue. 1116238106Sdes * or the query is for NS item that is required glue. 1117238106Sdes * o no addresses are provided. 1118238106Sdes * o RD qflag is on. 1119238106Sdes * Instead, go up one level, and try to get even further 1120238106Sdes * If the root was useless, use safety belt information. 1121238106Sdes * Only check cache returns, because replies for servers 1122238106Sdes * could be useless but lead to loops (bumping into the 1123238106Sdes * same server reply) if useless-checked. 1124238106Sdes */ 1125238106Sdes if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags, 1126238106Sdes iq->dp)) { 1127238106Sdes if(dname_is_root(iq->dp->name)) { 1128238106Sdes /* use safety belt */ 1129238106Sdes verbose(VERB_QUERY, "Cache has root NS but " 1130238106Sdes "no addresses. Fallback to the safety belt."); 1131238106Sdes iq->dp = hints_lookup_root(qstate->env->hints, 1132238106Sdes iq->qchase.qclass); 1133238106Sdes /* note deleg_msg is from previous lookup, 1134238106Sdes * but RD is on, so it is not used */ 1135238106Sdes if(!iq->dp) { 1136238106Sdes log_err("internal error: no hints dp"); 1137238106Sdes return error_response(qstate, id, 1138238106Sdes LDNS_RCODE_REFUSED); 1139238106Sdes } 1140238106Sdes iq->dp = delegpt_copy(iq->dp, qstate->region); 1141238106Sdes if(!iq->dp) { 1142238106Sdes log_err("out of memory in safety belt"); 1143238106Sdes return error_response(qstate, id, 1144238106Sdes LDNS_RCODE_SERVFAIL); 1145238106Sdes } 1146238106Sdes break; 1147238106Sdes } else { 1148238106Sdes verbose(VERB_ALGO, 1149238106Sdes "cache delegation was useless:"); 1150238106Sdes delegpt_log(VERB_ALGO, iq->dp); 1151238106Sdes /* go up */ 1152238106Sdes delname = iq->dp->name; 1153238106Sdes delnamelen = iq->dp->namelen; 1154238106Sdes dname_remove_label(&delname, &delnamelen); 1155238106Sdes } 1156238106Sdes } else break; 1157238106Sdes } 1158238106Sdes 1159238106Sdes verbose(VERB_ALGO, "cache delegation returns delegpt"); 1160238106Sdes delegpt_log(VERB_ALGO, iq->dp); 1161238106Sdes 1162238106Sdes /* Otherwise, set the current delegation point and move on to the 1163238106Sdes * next state. */ 1164238106Sdes return next_state(iq, INIT_REQUEST_2_STATE); 1165238106Sdes} 1166238106Sdes 1167238106Sdes/** 1168238106Sdes * Process the second part of the initial request handling. This state 1169238106Sdes * basically exists so that queries that generate root priming events have 1170238106Sdes * the same init processing as ones that do not. Request events that reach 1171238106Sdes * this state must have a valid currentDelegationPoint set. 1172238106Sdes * 1173238106Sdes * This part is primarly handling stub zone priming. Events that reach this 1174238106Sdes * state must have a current delegation point. 1175238106Sdes * 1176238106Sdes * @param qstate: query state. 1177238106Sdes * @param iq: iterator query state. 1178238106Sdes * @param id: module id. 1179238106Sdes * @return true if the event needs more request processing immediately, 1180238106Sdes * false if not. 1181238106Sdes */ 1182238106Sdesstatic int 1183238106SdesprocessInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq, 1184238106Sdes int id) 1185238106Sdes{ 1186238106Sdes uint8_t* delname; 1187238106Sdes size_t delnamelen; 1188238106Sdes log_query_info(VERB_QUERY, "resolving (init part 2): ", 1189238106Sdes &qstate->qinfo); 1190238106Sdes 1191238106Sdes if(iq->refetch_glue) { 1192238106Sdes if(!iq->dp) { 1193238106Sdes log_err("internal or malloc fail: no dp for refetch"); 1194238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1195238106Sdes } 1196238106Sdes delname = iq->dp->name; 1197238106Sdes delnamelen = iq->dp->namelen; 1198238106Sdes } else { 1199238106Sdes delname = iq->qchase.qname; 1200238106Sdes delnamelen = iq->qchase.qname_len; 1201238106Sdes } 1202238106Sdes if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) { 1203238106Sdes if(!dname_is_root(delname)) 1204238106Sdes dname_remove_label(&delname, &delnamelen); 1205238106Sdes iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */ 1206238106Sdes } 1207238106Sdes /* Check to see if we need to prime a stub zone. */ 1208238106Sdes if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) { 1209238106Sdes /* A priming sub request was made */ 1210238106Sdes return 0; 1211238106Sdes } 1212238106Sdes 1213238106Sdes /* most events just get forwarded to the next state. */ 1214238106Sdes return next_state(iq, INIT_REQUEST_3_STATE); 1215238106Sdes} 1216238106Sdes 1217238106Sdes/** 1218238106Sdes * Process the third part of the initial request handling. This state exists 1219238106Sdes * as a separate state so that queries that generate stub priming events 1220238106Sdes * will get the tail end of the init process but not repeat the stub priming 1221238106Sdes * check. 1222238106Sdes * 1223238106Sdes * @param qstate: query state. 1224238106Sdes * @param iq: iterator query state. 1225238106Sdes * @param id: module id. 1226238106Sdes * @return true, advancing the event to the QUERYTARGETS_STATE. 1227238106Sdes */ 1228238106Sdesstatic int 1229238106SdesprocessInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq, 1230238106Sdes int id) 1231238106Sdes{ 1232238106Sdes log_query_info(VERB_QUERY, "resolving (init part 3): ", 1233238106Sdes &qstate->qinfo); 1234238106Sdes /* if the cache reply dp equals a validation anchor or msg has DS, 1235238106Sdes * then DNSSEC RRSIGs are expected in the reply */ 1236238106Sdes iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp, 1237238106Sdes iq->deleg_msg, iq->qchase.qclass); 1238238106Sdes 1239238106Sdes /* If the RD flag wasn't set, then we just finish with the 1240238106Sdes * cached referral as the response. */ 1241238106Sdes if(!(qstate->query_flags & BIT_RD)) { 1242238106Sdes iq->response = iq->deleg_msg; 1243269257Sdes if(verbosity >= VERB_ALGO && iq->response) 1244238106Sdes log_dns_msg("no RD requested, using delegation msg", 1245238106Sdes &iq->response->qinfo, iq->response->rep); 1246238106Sdes if(qstate->reply_origin) 1247238106Sdes sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region); 1248238106Sdes return final_state(iq); 1249238106Sdes } 1250238106Sdes /* After this point, unset the RD flag -- this query is going to 1251238106Sdes * be sent to an auth. server. */ 1252238106Sdes iq->chase_flags &= ~BIT_RD; 1253238106Sdes 1254238106Sdes /* if dnssec expected, fetch key for the trust-anchor or cached-DS */ 1255238106Sdes if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 1256238106Sdes !(qstate->query_flags&BIT_CD)) { 1257238106Sdes generate_dnskey_prefetch(qstate, iq, id); 1258238106Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 1259238106Sdes qstate->env->detach_subs)); 1260238106Sdes (*qstate->env->detach_subs)(qstate); 1261238106Sdes } 1262238106Sdes 1263238106Sdes /* Jump to the next state. */ 1264238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1265238106Sdes} 1266238106Sdes 1267238106Sdes/** 1268238106Sdes * Given a basic query, generate a parent-side "target" query. 1269238106Sdes * These are subordinate queries for missing delegation point target addresses, 1270238106Sdes * for which only the parent of the delegation provides correct IP addresses. 1271238106Sdes * 1272238106Sdes * @param qstate: query state. 1273238106Sdes * @param iq: iterator query state. 1274238106Sdes * @param id: module id. 1275238106Sdes * @param name: target qname. 1276238106Sdes * @param namelen: target qname length. 1277238106Sdes * @param qtype: target qtype (either A or AAAA). 1278238106Sdes * @param qclass: target qclass. 1279238106Sdes * @return true on success, false on failure. 1280238106Sdes */ 1281238106Sdesstatic int 1282238106Sdesgenerate_parentside_target_query(struct module_qstate* qstate, 1283238106Sdes struct iter_qstate* iq, int id, uint8_t* name, size_t namelen, 1284238106Sdes uint16_t qtype, uint16_t qclass) 1285238106Sdes{ 1286238106Sdes struct module_qstate* subq; 1287238106Sdes if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1288238106Sdes id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1289238106Sdes return 0; 1290238106Sdes if(subq) { 1291238106Sdes struct iter_qstate* subiq = 1292238106Sdes (struct iter_qstate*)subq->minfo[id]; 1293238106Sdes /* blacklist the cache - we want to fetch parent stuff */ 1294238106Sdes sock_list_insert(&subq->blacklist, NULL, 0, subq->region); 1295238106Sdes subiq->query_for_pside_glue = 1; 1296238106Sdes if(dname_subdomain_c(name, iq->dp->name)) { 1297238106Sdes subiq->dp = delegpt_copy(iq->dp, subq->region); 1298238106Sdes subiq->dnssec_expected = iter_indicates_dnssec( 1299238106Sdes qstate->env, subiq->dp, NULL, 1300238106Sdes subq->qinfo.qclass); 1301238106Sdes subiq->refetch_glue = 1; 1302238106Sdes } else { 1303238106Sdes subiq->dp = dns_cache_find_delegation(qstate->env, 1304238106Sdes name, namelen, qtype, qclass, subq->region, 1305238106Sdes &subiq->deleg_msg, 1306238106Sdes *qstate->env->now+subq->prefetch_leeway); 1307238106Sdes /* if no dp, then it's from root, refetch unneeded */ 1308238106Sdes if(subiq->dp) { 1309238106Sdes subiq->dnssec_expected = iter_indicates_dnssec( 1310238106Sdes qstate->env, subiq->dp, NULL, 1311238106Sdes subq->qinfo.qclass); 1312238106Sdes subiq->refetch_glue = 1; 1313238106Sdes } 1314238106Sdes } 1315238106Sdes } 1316238106Sdes log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass); 1317238106Sdes return 1; 1318238106Sdes} 1319238106Sdes 1320238106Sdes/** 1321238106Sdes * Given a basic query, generate a "target" query. These are subordinate 1322238106Sdes * queries for missing delegation point target addresses. 1323238106Sdes * 1324238106Sdes * @param qstate: query state. 1325238106Sdes * @param iq: iterator query state. 1326238106Sdes * @param id: module id. 1327238106Sdes * @param name: target qname. 1328238106Sdes * @param namelen: target qname length. 1329238106Sdes * @param qtype: target qtype (either A or AAAA). 1330238106Sdes * @param qclass: target qclass. 1331238106Sdes * @return true on success, false on failure. 1332238106Sdes */ 1333238106Sdesstatic int 1334238106Sdesgenerate_target_query(struct module_qstate* qstate, struct iter_qstate* iq, 1335238106Sdes int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass) 1336238106Sdes{ 1337238106Sdes struct module_qstate* subq; 1338238106Sdes if(!generate_sub_request(name, namelen, qtype, qclass, qstate, 1339238106Sdes id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) 1340238106Sdes return 0; 1341238106Sdes log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass); 1342238106Sdes return 1; 1343238106Sdes} 1344238106Sdes 1345238106Sdes/** 1346238106Sdes * Given an event at a certain state, generate zero or more target queries 1347238106Sdes * for it's current delegation point. 1348238106Sdes * 1349238106Sdes * @param qstate: query state. 1350238106Sdes * @param iq: iterator query state. 1351238106Sdes * @param ie: iterator shared global environment. 1352238106Sdes * @param id: module id. 1353238106Sdes * @param maxtargets: The maximum number of targets to query for. 1354238106Sdes * if it is negative, there is no maximum number of targets. 1355238106Sdes * @param num: returns the number of queries generated and processed, 1356238106Sdes * which may be zero if there were no missing targets. 1357238106Sdes * @return false on error. 1358238106Sdes */ 1359238106Sdesstatic int 1360238106Sdesquery_for_targets(struct module_qstate* qstate, struct iter_qstate* iq, 1361238106Sdes struct iter_env* ie, int id, int maxtargets, int* num) 1362238106Sdes{ 1363238106Sdes int query_count = 0; 1364238106Sdes struct delegpt_ns* ns; 1365238106Sdes int missing; 1366238106Sdes int toget = 0; 1367238106Sdes 1368238106Sdes if(iq->depth == ie->max_dependency_depth) 1369238106Sdes return 0; 1370275854Sdelphij if(iq->depth > 0 && iq->target_count && 1371275854Sdelphij iq->target_count[1] > MAX_TARGET_COUNT) { 1372275854Sdelphij verbose(VERB_QUERY, "request has exceeded the maximum " 1373275854Sdelphij "number of glue fetches %d", iq->target_count[1]); 1374275854Sdelphij return 0; 1375275854Sdelphij } 1376238106Sdes 1377238106Sdes iter_mark_cycle_targets(qstate, iq->dp); 1378238106Sdes missing = (int)delegpt_count_missing_targets(iq->dp); 1379238106Sdes log_assert(maxtargets != 0); /* that would not be useful */ 1380238106Sdes 1381238106Sdes /* Generate target requests. Basically, any missing targets 1382238106Sdes * are queried for here, regardless if it is necessary to do 1383238106Sdes * so to continue processing. */ 1384238106Sdes if(maxtargets < 0 || maxtargets > missing) 1385238106Sdes toget = missing; 1386238106Sdes else toget = maxtargets; 1387238106Sdes if(toget == 0) { 1388238106Sdes *num = 0; 1389238106Sdes return 1; 1390238106Sdes } 1391238106Sdes /* select 'toget' items from the total of 'missing' items */ 1392238106Sdes log_assert(toget <= missing); 1393238106Sdes 1394238106Sdes /* loop over missing targets */ 1395238106Sdes for(ns = iq->dp->nslist; ns; ns = ns->next) { 1396238106Sdes if(ns->resolved) 1397238106Sdes continue; 1398238106Sdes 1399238106Sdes /* randomly select this item with probability toget/missing */ 1400238106Sdes if(!iter_ns_probability(qstate->env->rnd, toget, missing)) { 1401238106Sdes /* do not select this one, next; select toget number 1402238106Sdes * of items from a list one less in size */ 1403238106Sdes missing --; 1404238106Sdes continue; 1405238106Sdes } 1406238106Sdes 1407238106Sdes if(ie->supports_ipv6 && !ns->got6) { 1408238106Sdes /* Send the AAAA request. */ 1409238106Sdes if(!generate_target_query(qstate, iq, id, 1410238106Sdes ns->name, ns->namelen, 1411238106Sdes LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) { 1412238106Sdes *num = query_count; 1413238106Sdes if(query_count > 0) 1414238106Sdes qstate->ext_state[id] = module_wait_subquery; 1415238106Sdes return 0; 1416238106Sdes } 1417238106Sdes query_count++; 1418238106Sdes } 1419238106Sdes /* Send the A request. */ 1420238106Sdes if(ie->supports_ipv4 && !ns->got4) { 1421238106Sdes if(!generate_target_query(qstate, iq, id, 1422238106Sdes ns->name, ns->namelen, 1423238106Sdes LDNS_RR_TYPE_A, iq->qchase.qclass)) { 1424238106Sdes *num = query_count; 1425238106Sdes if(query_count > 0) 1426238106Sdes qstate->ext_state[id] = module_wait_subquery; 1427238106Sdes return 0; 1428238106Sdes } 1429238106Sdes query_count++; 1430238106Sdes } 1431238106Sdes 1432238106Sdes /* mark this target as in progress. */ 1433238106Sdes ns->resolved = 1; 1434238106Sdes missing--; 1435238106Sdes toget--; 1436238106Sdes if(toget == 0) 1437238106Sdes break; 1438238106Sdes } 1439238106Sdes *num = query_count; 1440238106Sdes if(query_count > 0) 1441238106Sdes qstate->ext_state[id] = module_wait_subquery; 1442238106Sdes 1443238106Sdes return 1; 1444238106Sdes} 1445238106Sdes 1446269257Sdes/** see if last resort is possible - does config allow queries to parent */ 1447269257Sdesstatic int 1448269257Sdescan_have_last_resort(struct module_env* env, struct delegpt* dp, 1449269257Sdes struct iter_qstate* iq) 1450269257Sdes{ 1451269257Sdes struct delegpt* fwddp; 1452269257Sdes struct iter_hints_stub* stub; 1453269257Sdes /* do not process a last resort (the parent side) if a stub 1454269257Sdes * or forward is configured, because we do not want to go 'above' 1455269257Sdes * the configured servers */ 1456269257Sdes if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*) 1457269257Sdes name_tree_find(&env->hints->tree, dp->name, dp->namelen, 1458269257Sdes dp->namelabs, iq->qchase.qclass)) && 1459269257Sdes /* has_parent side is turned off for stub_first, where we 1460269257Sdes * are allowed to go to the parent */ 1461269257Sdes stub->dp->has_parent_side_NS) { 1462269257Sdes verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL"); 1463269257Sdes return 0; 1464269257Sdes } 1465269257Sdes if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) && 1466269257Sdes /* has_parent_side is turned off for forward_first, where 1467269257Sdes * we are allowed to go to the parent */ 1468269257Sdes fwddp->has_parent_side_NS) { 1469269257Sdes verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL"); 1470269257Sdes return 0; 1471269257Sdes } 1472269257Sdes return 1; 1473269257Sdes} 1474269257Sdes 1475238106Sdes/** 1476238106Sdes * Called by processQueryTargets when it would like extra targets to query 1477238106Sdes * but it seems to be out of options. At last resort some less appealing 1478238106Sdes * options are explored. If there are no more options, the result is SERVFAIL 1479238106Sdes * 1480238106Sdes * @param qstate: query state. 1481238106Sdes * @param iq: iterator query state. 1482238106Sdes * @param ie: iterator shared global environment. 1483238106Sdes * @param id: module id. 1484238106Sdes * @return true if the event requires more request processing immediately, 1485238106Sdes * false if not. 1486238106Sdes */ 1487238106Sdesstatic int 1488238106SdesprocessLastResort(struct module_qstate* qstate, struct iter_qstate* iq, 1489238106Sdes struct iter_env* ie, int id) 1490238106Sdes{ 1491238106Sdes struct delegpt_ns* ns; 1492238106Sdes int query_count = 0; 1493238106Sdes verbose(VERB_ALGO, "No more query targets, attempting last resort"); 1494238106Sdes log_assert(iq->dp); 1495238106Sdes 1496269257Sdes if(!can_have_last_resort(qstate->env, iq->dp, iq)) { 1497269257Sdes /* fail -- no more targets, no more hope of targets, no hope 1498269257Sdes * of a response. */ 1499269257Sdes return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1500269257Sdes } 1501249141Sdes if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) { 1502249141Sdes struct delegpt* p = hints_lookup_root(qstate->env->hints, 1503249141Sdes iq->qchase.qclass); 1504249141Sdes if(p) { 1505249141Sdes struct delegpt_ns* ns; 1506249141Sdes struct delegpt_addr* a; 1507249141Sdes iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1508249141Sdes for(ns = p->nslist; ns; ns=ns->next) { 1509249141Sdes (void)delegpt_add_ns(iq->dp, qstate->region, 1510269257Sdes ns->name, ns->lame); 1511249141Sdes } 1512249141Sdes for(a = p->target_list; a; a=a->next_target) { 1513249141Sdes (void)delegpt_add_addr(iq->dp, qstate->region, 1514249141Sdes &a->addr, a->addrlen, a->bogus, 1515249141Sdes a->lame); 1516249141Sdes } 1517249141Sdes } 1518249141Sdes iq->dp->has_parent_side_NS = 1; 1519249141Sdes } else if(!iq->dp->has_parent_side_NS) { 1520238106Sdes if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp, 1521238106Sdes qstate->region, &qstate->qinfo) 1522238106Sdes || !iq->dp->has_parent_side_NS) { 1523238106Sdes /* if: malloc failure in lookup go up to try */ 1524238106Sdes /* if: no parent NS in cache - go up one level */ 1525238106Sdes verbose(VERB_ALGO, "try to grab parent NS"); 1526238106Sdes iq->store_parent_NS = iq->dp; 1527249141Sdes iq->chase_flags &= ~BIT_RD; /* go to authorities */ 1528238106Sdes iq->deleg_msg = NULL; 1529238106Sdes iq->refetch_glue = 1; 1530238106Sdes iq->query_restart_count++; 1531238106Sdes iq->sent_count = 0; 1532238106Sdes return next_state(iq, INIT_REQUEST_STATE); 1533238106Sdes } 1534238106Sdes } 1535238106Sdes /* see if that makes new names available */ 1536238106Sdes if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 1537238106Sdes qstate->region, iq->dp)) 1538238106Sdes log_err("out of memory in cache_fill_missing"); 1539238106Sdes if(iq->dp->usable_list) { 1540238106Sdes verbose(VERB_ALGO, "try parent-side-name, w. glue from cache"); 1541238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1542238106Sdes } 1543238106Sdes /* try to fill out parent glue from cache */ 1544238106Sdes if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp, 1545238106Sdes qstate->region, &qstate->qinfo)) { 1546238106Sdes /* got parent stuff from cache, see if we can continue */ 1547238106Sdes verbose(VERB_ALGO, "try parent-side glue from cache"); 1548238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1549238106Sdes } 1550238106Sdes /* query for an extra name added by the parent-NS record */ 1551238106Sdes if(delegpt_count_missing_targets(iq->dp) > 0) { 1552238106Sdes int qs = 0; 1553238106Sdes verbose(VERB_ALGO, "try parent-side target name"); 1554238106Sdes if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) { 1555238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1556238106Sdes } 1557238106Sdes iq->num_target_queries += qs; 1558275854Sdelphij target_count_increase(iq, qs); 1559238106Sdes if(qs != 0) { 1560238106Sdes qstate->ext_state[id] = module_wait_subquery; 1561238106Sdes return 0; /* and wait for them */ 1562238106Sdes } 1563238106Sdes } 1564238106Sdes if(iq->depth == ie->max_dependency_depth) { 1565238106Sdes verbose(VERB_QUERY, "maxdepth and need more nameservers, fail"); 1566238106Sdes return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1567238106Sdes } 1568275854Sdelphij if(iq->depth > 0 && iq->target_count && 1569275854Sdelphij iq->target_count[1] > MAX_TARGET_COUNT) { 1570275854Sdelphij verbose(VERB_QUERY, "request has exceeded the maximum " 1571275854Sdelphij "number of glue fetches %d", iq->target_count[1]); 1572275854Sdelphij return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1573275854Sdelphij } 1574238106Sdes /* mark cycle targets for parent-side lookups */ 1575238106Sdes iter_mark_pside_cycle_targets(qstate, iq->dp); 1576238106Sdes /* see if we can issue queries to get nameserver addresses */ 1577238106Sdes /* this lookup is not randomized, but sequential. */ 1578238106Sdes for(ns = iq->dp->nslist; ns; ns = ns->next) { 1579238106Sdes /* query for parent-side A and AAAA for nameservers */ 1580238106Sdes if(ie->supports_ipv6 && !ns->done_pside6) { 1581238106Sdes /* Send the AAAA request. */ 1582238106Sdes if(!generate_parentside_target_query(qstate, iq, id, 1583238106Sdes ns->name, ns->namelen, 1584238106Sdes LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) 1585238106Sdes return error_response(qstate, id, 1586238106Sdes LDNS_RCODE_SERVFAIL); 1587238106Sdes ns->done_pside6 = 1; 1588238106Sdes query_count++; 1589238106Sdes } 1590238106Sdes if(ie->supports_ipv4 && !ns->done_pside4) { 1591238106Sdes /* Send the A request. */ 1592238106Sdes if(!generate_parentside_target_query(qstate, iq, id, 1593238106Sdes ns->name, ns->namelen, 1594238106Sdes LDNS_RR_TYPE_A, iq->qchase.qclass)) 1595238106Sdes return error_response(qstate, id, 1596238106Sdes LDNS_RCODE_SERVFAIL); 1597238106Sdes ns->done_pside4 = 1; 1598238106Sdes query_count++; 1599238106Sdes } 1600238106Sdes if(query_count != 0) { /* suspend to await results */ 1601238106Sdes verbose(VERB_ALGO, "try parent-side glue lookup"); 1602238106Sdes iq->num_target_queries += query_count; 1603275854Sdelphij target_count_increase(iq, query_count); 1604238106Sdes qstate->ext_state[id] = module_wait_subquery; 1605238106Sdes return 0; 1606238106Sdes } 1607238106Sdes } 1608238106Sdes 1609238106Sdes /* if this was a parent-side glue query itself, then store that 1610238106Sdes * failure in cache. */ 1611238106Sdes if(iq->query_for_pside_glue && !iq->pside_glue) 1612238106Sdes iter_store_parentside_neg(qstate->env, &qstate->qinfo, 1613238106Sdes iq->deleg_msg?iq->deleg_msg->rep: 1614238106Sdes (iq->response?iq->response->rep:NULL)); 1615238106Sdes 1616238106Sdes verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL"); 1617238106Sdes /* fail -- no more targets, no more hope of targets, no hope 1618238106Sdes * of a response. */ 1619238106Sdes return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1620238106Sdes} 1621238106Sdes 1622238106Sdes/** 1623238106Sdes * Try to find the NS record set that will resolve a qtype DS query. Due 1624238106Sdes * to grandparent/grandchild reasons we did not get a proper lookup right 1625238106Sdes * away. We need to create type NS queries until we get the right parent 1626238106Sdes * for this lookup. We remove labels from the query to find the right point. 1627238106Sdes * If we end up at the old dp name, then there is no solution. 1628238106Sdes * 1629238106Sdes * @param qstate: query state. 1630238106Sdes * @param iq: iterator query state. 1631238106Sdes * @param id: module id. 1632238106Sdes * @return true if the event requires more immediate processing, false if 1633238106Sdes * not. This is generally only true when forwarding the request to 1634238106Sdes * the final state (i.e., on answer). 1635238106Sdes */ 1636238106Sdesstatic int 1637249141SdesprocessDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id) 1638238106Sdes{ 1639238106Sdes struct module_qstate* subq = NULL; 1640238106Sdes verbose(VERB_ALGO, "processDSNSFind"); 1641238106Sdes 1642238106Sdes if(!iq->dsns_point) { 1643238106Sdes /* initialize */ 1644238106Sdes iq->dsns_point = iq->qchase.qname; 1645238106Sdes iq->dsns_point_len = iq->qchase.qname_len; 1646238106Sdes } 1647238106Sdes /* robustcheck for internal error: we are not underneath the dp */ 1648238106Sdes if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) { 1649238106Sdes return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1650238106Sdes } 1651238106Sdes 1652238106Sdes /* go up one (more) step, until we hit the dp, if so, end */ 1653238106Sdes dname_remove_label(&iq->dsns_point, &iq->dsns_point_len); 1654238106Sdes if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) { 1655238106Sdes /* there was no inbetween nameserver, use the old delegation 1656238106Sdes * point again. And this time, because dsns_point is nonNULL 1657238106Sdes * we are going to accept the (bad) result */ 1658238106Sdes iq->state = QUERYTARGETS_STATE; 1659238106Sdes return 1; 1660238106Sdes } 1661238106Sdes iq->state = DSNS_FIND_STATE; 1662238106Sdes 1663238106Sdes /* spawn NS lookup (validation not needed, this is for DS lookup) */ 1664238106Sdes log_nametypeclass(VERB_ALGO, "fetch nameservers", 1665238106Sdes iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass); 1666238106Sdes if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len, 1667238106Sdes LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq, 1668238106Sdes INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) { 1669238106Sdes return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL); 1670238106Sdes } 1671238106Sdes 1672238106Sdes return 0; 1673238106Sdes} 1674238106Sdes 1675238106Sdes/** 1676238106Sdes * This is the request event state where the request will be sent to one of 1677238106Sdes * its current query targets. This state also handles issuing target lookup 1678238106Sdes * queries for missing target IP addresses. Queries typically iterate on 1679238106Sdes * this state, both when they are just trying different targets for a given 1680238106Sdes * delegation point, and when they change delegation points. This state 1681238106Sdes * roughly corresponds to RFC 1034 algorithm steps 3 and 4. 1682238106Sdes * 1683238106Sdes * @param qstate: query state. 1684238106Sdes * @param iq: iterator query state. 1685238106Sdes * @param ie: iterator shared global environment. 1686238106Sdes * @param id: module id. 1687238106Sdes * @return true if the event requires more request processing immediately, 1688238106Sdes * false if not. This state only returns true when it is generating 1689238106Sdes * a SERVFAIL response because the query has hit a dead end. 1690238106Sdes */ 1691238106Sdesstatic int 1692238106SdesprocessQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq, 1693238106Sdes struct iter_env* ie, int id) 1694238106Sdes{ 1695238106Sdes int tf_policy; 1696238106Sdes struct delegpt_addr* target; 1697238106Sdes struct outbound_entry* outq; 1698238106Sdes 1699238106Sdes /* NOTE: a request will encounter this state for each target it 1700238106Sdes * needs to send a query to. That is, at least one per referral, 1701238106Sdes * more if some targets timeout or return throwaway answers. */ 1702238106Sdes 1703238106Sdes log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo); 1704238106Sdes verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, " 1705238106Sdes "currentqueries %d sentcount %d", iq->num_target_queries, 1706238106Sdes iq->num_current_queries, iq->sent_count); 1707238106Sdes 1708238106Sdes /* Make sure that we haven't run away */ 1709238106Sdes /* FIXME: is this check even necessary? */ 1710238106Sdes if(iq->referral_count > MAX_REFERRAL_COUNT) { 1711238106Sdes verbose(VERB_QUERY, "request has exceeded the maximum " 1712238106Sdes "number of referrrals with %d", iq->referral_count); 1713238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1714238106Sdes } 1715238106Sdes if(iq->sent_count > MAX_SENT_COUNT) { 1716238106Sdes verbose(VERB_QUERY, "request has exceeded the maximum " 1717238106Sdes "number of sends with %d", iq->sent_count); 1718238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1719238106Sdes } 1720238106Sdes 1721238106Sdes /* Make sure we have a delegation point, otherwise priming failed 1722238106Sdes * or another failure occurred */ 1723238106Sdes if(!iq->dp) { 1724238106Sdes verbose(VERB_QUERY, "Failed to get a delegation, giving up"); 1725238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1726238106Sdes } 1727238106Sdes if(!ie->supports_ipv6) 1728238106Sdes delegpt_no_ipv6(iq->dp); 1729238106Sdes if(!ie->supports_ipv4) 1730238106Sdes delegpt_no_ipv4(iq->dp); 1731238106Sdes delegpt_log(VERB_ALGO, iq->dp); 1732238106Sdes 1733238106Sdes if(iq->num_current_queries>0) { 1734238106Sdes /* already busy answering a query, this restart is because 1735238106Sdes * more delegpt addrs became available, wait for existing 1736238106Sdes * query. */ 1737238106Sdes verbose(VERB_ALGO, "woke up, but wait for outstanding query"); 1738238106Sdes qstate->ext_state[id] = module_wait_reply; 1739238106Sdes return 0; 1740238106Sdes } 1741238106Sdes 1742238106Sdes tf_policy = 0; 1743238106Sdes /* < not <=, because although the array is large enough for <=, the 1744238106Sdes * generated query will immediately be discarded due to depth and 1745238106Sdes * that servfail is cached, which is not good as opportunism goes. */ 1746238106Sdes if(iq->depth < ie->max_dependency_depth 1747238106Sdes && iq->sent_count < TARGET_FETCH_STOP) { 1748238106Sdes tf_policy = ie->target_fetch_policy[iq->depth]; 1749238106Sdes } 1750238106Sdes 1751238106Sdes /* if in 0x20 fallback get as many targets as possible */ 1752238106Sdes if(iq->caps_fallback) { 1753238106Sdes int extra = 0; 1754238106Sdes size_t naddr, nres, navail; 1755238106Sdes if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) { 1756238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 1757238106Sdes } 1758238106Sdes iq->num_target_queries += extra; 1759275854Sdelphij target_count_increase(iq, extra); 1760238106Sdes if(iq->num_target_queries > 0) { 1761238106Sdes /* wait to get all targets, we want to try em */ 1762238106Sdes verbose(VERB_ALGO, "wait for all targets for fallback"); 1763238106Sdes qstate->ext_state[id] = module_wait_reply; 1764238106Sdes return 0; 1765238106Sdes } 1766238106Sdes /* did we do enough fallback queries already? */ 1767238106Sdes delegpt_count_addr(iq->dp, &naddr, &nres, &navail); 1768238106Sdes /* the current caps_server is the number of fallbacks sent. 1769238106Sdes * the original query is one that matched too, so we have 1770238106Sdes * caps_server+1 number of matching queries now */ 1771238106Sdes if(iq->caps_server+1 >= naddr*3 || 1772238106Sdes iq->caps_server+1 >= MAX_SENT_COUNT) { 1773238106Sdes /* we're done, process the response */ 1774238106Sdes verbose(VERB_ALGO, "0x20 fallback had %d responses " 1775238106Sdes "match for %d wanted, done.", 1776238106Sdes (int)iq->caps_server+1, (int)naddr*3); 1777238106Sdes iq->caps_fallback = 0; 1778238106Sdes iter_dec_attempts(iq->dp, 3); /* space for fallback */ 1779238106Sdes iq->num_current_queries++; /* RespState decrements it*/ 1780238106Sdes iq->referral_count++; /* make sure we don't loop */ 1781238106Sdes iq->sent_count = 0; 1782238106Sdes iq->state = QUERY_RESP_STATE; 1783238106Sdes return 1; 1784238106Sdes } 1785238106Sdes verbose(VERB_ALGO, "0x20 fallback number %d", 1786238106Sdes (int)iq->caps_server); 1787238106Sdes 1788238106Sdes /* if there is a policy to fetch missing targets 1789238106Sdes * opportunistically, do it. we rely on the fact that once a 1790238106Sdes * query (or queries) for a missing name have been issued, 1791238106Sdes * they will not show up again. */ 1792238106Sdes } else if(tf_policy != 0) { 1793238106Sdes int extra = 0; 1794238106Sdes verbose(VERB_ALGO, "attempt to get extra %d targets", 1795238106Sdes tf_policy); 1796238106Sdes (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra); 1797238106Sdes /* errors ignored, these targets are not strictly necessary for 1798238106Sdes * this result, we do not have to reply with SERVFAIL */ 1799238106Sdes iq->num_target_queries += extra; 1800275854Sdelphij target_count_increase(iq, extra); 1801238106Sdes } 1802238106Sdes 1803238106Sdes /* Add the current set of unused targets to our queue. */ 1804238106Sdes delegpt_add_unused_targets(iq->dp); 1805238106Sdes 1806238106Sdes /* Select the next usable target, filtering out unsuitable targets. */ 1807238106Sdes target = iter_server_selection(ie, qstate->env, iq->dp, 1808238106Sdes iq->dp->name, iq->dp->namelen, iq->qchase.qtype, 1809238106Sdes &iq->dnssec_lame_query, &iq->chase_to_rd, 1810238106Sdes iq->num_target_queries, qstate->blacklist); 1811238106Sdes 1812238106Sdes /* If no usable target was selected... */ 1813238106Sdes if(!target) { 1814238106Sdes /* Here we distinguish between three states: generate a new 1815238106Sdes * target query, just wait, or quit (with a SERVFAIL). 1816238106Sdes * We have the following information: number of active 1817238106Sdes * target queries, number of active current queries, 1818238106Sdes * the presence of missing targets at this delegation 1819238106Sdes * point, and the given query target policy. */ 1820238106Sdes 1821238106Sdes /* Check for the wait condition. If this is true, then 1822238106Sdes * an action must be taken. */ 1823238106Sdes if(iq->num_target_queries==0 && iq->num_current_queries==0) { 1824238106Sdes /* If there is nothing to wait for, then we need 1825238106Sdes * to distinguish between generating (a) new target 1826238106Sdes * query, or failing. */ 1827238106Sdes if(delegpt_count_missing_targets(iq->dp) > 0) { 1828238106Sdes int qs = 0; 1829238106Sdes verbose(VERB_ALGO, "querying for next " 1830238106Sdes "missing target"); 1831238106Sdes if(!query_for_targets(qstate, iq, ie, id, 1832238106Sdes 1, &qs)) { 1833238106Sdes return error_response(qstate, id, 1834238106Sdes LDNS_RCODE_SERVFAIL); 1835238106Sdes } 1836238106Sdes if(qs == 0 && 1837238106Sdes delegpt_count_missing_targets(iq->dp) == 0){ 1838238106Sdes /* it looked like there were missing 1839238106Sdes * targets, but they did not turn up. 1840238106Sdes * Try the bad choices again (if any), 1841238106Sdes * when we get back here missing==0, 1842238106Sdes * so this is not a loop. */ 1843238106Sdes return 1; 1844238106Sdes } 1845238106Sdes iq->num_target_queries += qs; 1846275854Sdelphij target_count_increase(iq, qs); 1847238106Sdes } 1848238106Sdes /* Since a target query might have been made, we 1849238106Sdes * need to check again. */ 1850238106Sdes if(iq->num_target_queries == 0) { 1851238106Sdes return processLastResort(qstate, iq, ie, id); 1852238106Sdes } 1853238106Sdes } 1854238106Sdes 1855238106Sdes /* otherwise, we have no current targets, so submerge 1856238106Sdes * until one of the target or direct queries return. */ 1857238106Sdes if(iq->num_target_queries>0 && iq->num_current_queries>0) { 1858238106Sdes verbose(VERB_ALGO, "no current targets -- waiting " 1859238106Sdes "for %d targets to resolve or %d outstanding" 1860238106Sdes " queries to respond", iq->num_target_queries, 1861238106Sdes iq->num_current_queries); 1862238106Sdes qstate->ext_state[id] = module_wait_reply; 1863238106Sdes } else if(iq->num_target_queries>0) { 1864238106Sdes verbose(VERB_ALGO, "no current targets -- waiting " 1865238106Sdes "for %d targets to resolve.", 1866238106Sdes iq->num_target_queries); 1867238106Sdes qstate->ext_state[id] = module_wait_subquery; 1868238106Sdes } else { 1869238106Sdes verbose(VERB_ALGO, "no current targets -- waiting " 1870238106Sdes "for %d outstanding queries to respond.", 1871238106Sdes iq->num_current_queries); 1872238106Sdes qstate->ext_state[id] = module_wait_reply; 1873238106Sdes } 1874238106Sdes return 0; 1875238106Sdes } 1876238106Sdes 1877238106Sdes /* We have a valid target. */ 1878238106Sdes if(verbosity >= VERB_QUERY) { 1879238106Sdes log_query_info(VERB_QUERY, "sending query:", &iq->qchase); 1880238106Sdes log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name, 1881238106Sdes &target->addr, target->addrlen); 1882238106Sdes verbose(VERB_ALGO, "dnssec status: %s%s", 1883238106Sdes iq->dnssec_expected?"expected": "not expected", 1884238106Sdes iq->dnssec_lame_query?" but lame_query anyway": ""); 1885238106Sdes } 1886238106Sdes fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query)); 1887238106Sdes outq = (*qstate->env->send_query)( 1888238106Sdes iq->qchase.qname, iq->qchase.qname_len, 1889238106Sdes iq->qchase.qtype, iq->qchase.qclass, 1890238106Sdes iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD, 1891238106Sdes iq->dnssec_expected, &target->addr, target->addrlen, 1892238106Sdes iq->dp->name, iq->dp->namelen, qstate); 1893238106Sdes if(!outq) { 1894238106Sdes log_addr(VERB_DETAIL, "error sending query to auth server", 1895238106Sdes &target->addr, target->addrlen); 1896238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1897238106Sdes } 1898238106Sdes outbound_list_insert(&iq->outlist, outq); 1899238106Sdes iq->num_current_queries++; 1900238106Sdes iq->sent_count++; 1901238106Sdes qstate->ext_state[id] = module_wait_reply; 1902238106Sdes 1903238106Sdes return 0; 1904238106Sdes} 1905238106Sdes 1906238106Sdes/** find NS rrset in given list */ 1907238106Sdesstatic struct ub_packed_rrset_key* 1908238106Sdesfind_NS(struct reply_info* rep, size_t from, size_t to) 1909238106Sdes{ 1910238106Sdes size_t i; 1911238106Sdes for(i=from; i<to; i++) { 1912238106Sdes if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS) 1913238106Sdes return rep->rrsets[i]; 1914238106Sdes } 1915238106Sdes return NULL; 1916238106Sdes} 1917238106Sdes 1918238106Sdes 1919238106Sdes/** 1920238106Sdes * Process the query response. All queries end up at this state first. This 1921238106Sdes * process generally consists of analyzing the response and routing the 1922238106Sdes * event to the next state (either bouncing it back to a request state, or 1923238106Sdes * terminating the processing for this event). 1924238106Sdes * 1925238106Sdes * @param qstate: query state. 1926238106Sdes * @param iq: iterator query state. 1927238106Sdes * @param id: module id. 1928238106Sdes * @return true if the event requires more immediate processing, false if 1929238106Sdes * not. This is generally only true when forwarding the request to 1930238106Sdes * the final state (i.e., on answer). 1931238106Sdes */ 1932238106Sdesstatic int 1933238106SdesprocessQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq, 1934238106Sdes int id) 1935238106Sdes{ 1936238106Sdes int dnsseclame = 0; 1937238106Sdes enum response_type type; 1938238106Sdes iq->num_current_queries--; 1939238106Sdes if(iq->response == NULL) { 1940238106Sdes iq->chase_to_rd = 0; 1941238106Sdes iq->dnssec_lame_query = 0; 1942238106Sdes verbose(VERB_ALGO, "query response was timeout"); 1943238106Sdes return next_state(iq, QUERYTARGETS_STATE); 1944238106Sdes } 1945238106Sdes type = response_type_from_server( 1946238106Sdes (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 1947238106Sdes iq->response, &iq->qchase, iq->dp); 1948238106Sdes iq->chase_to_rd = 0; 1949238106Sdes if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) { 1950238106Sdes /* When forwarding (RD bit is set), we handle referrals 1951238106Sdes * differently. No queries should be sent elsewhere */ 1952238106Sdes type = RESPONSE_TYPE_ANSWER; 1953238106Sdes } 1954238106Sdes if(iq->dnssec_expected && !iq->dnssec_lame_query && 1955238106Sdes !(iq->chase_flags&BIT_RD) 1956238106Sdes && type != RESPONSE_TYPE_LAME 1957238106Sdes && type != RESPONSE_TYPE_REC_LAME 1958238106Sdes && type != RESPONSE_TYPE_THROWAWAY 1959238106Sdes && type != RESPONSE_TYPE_UNTYPED) { 1960238106Sdes /* a possible answer, see if it is missing DNSSEC */ 1961238106Sdes /* but not when forwarding, so we dont mark fwder lame */ 1962269257Sdes if(!iter_msg_has_dnssec(iq->response)) { 1963269257Sdes /* Mark this address as dnsseclame in this dp, 1964269257Sdes * because that will make serverselection disprefer 1965269257Sdes * it, but also, once it is the only final option, 1966269257Sdes * use dnssec-lame-bypass if it needs to query there.*/ 1967269257Sdes if(qstate->reply) { 1968269257Sdes struct delegpt_addr* a = delegpt_find_addr( 1969269257Sdes iq->dp, &qstate->reply->addr, 1970269257Sdes qstate->reply->addrlen); 1971269257Sdes if(a) a->dnsseclame = 1; 1972269257Sdes } 1973269257Sdes /* test the answer is from the zone we expected, 1974269257Sdes * otherwise, (due to parent,child on same server), we 1975269257Sdes * might mark the server,zone lame inappropriately */ 1976269257Sdes if(!iter_msg_from_zone(iq->response, iq->dp, type, 1977269257Sdes iq->qchase.qclass)) 1978269257Sdes qstate->reply = NULL; 1979238106Sdes type = RESPONSE_TYPE_LAME; 1980238106Sdes dnsseclame = 1; 1981238106Sdes } 1982238106Sdes } else iq->dnssec_lame_query = 0; 1983238106Sdes /* see if referral brings us close to the target */ 1984238106Sdes if(type == RESPONSE_TYPE_REFERRAL) { 1985238106Sdes struct ub_packed_rrset_key* ns = find_NS( 1986238106Sdes iq->response->rep, iq->response->rep->an_numrrsets, 1987238106Sdes iq->response->rep->an_numrrsets 1988238106Sdes + iq->response->rep->ns_numrrsets); 1989238106Sdes if(!ns) ns = find_NS(iq->response->rep, 0, 1990238106Sdes iq->response->rep->an_numrrsets); 1991238106Sdes if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name) 1992238106Sdes || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){ 1993238106Sdes verbose(VERB_ALGO, "bad referral, throwaway"); 1994238106Sdes type = RESPONSE_TYPE_THROWAWAY; 1995238106Sdes } else 1996238106Sdes iter_scrub_ds(iq->response, ns, iq->dp->name); 1997238106Sdes } else iter_scrub_ds(iq->response, NULL, NULL); 1998238106Sdes 1999238106Sdes /* handle each of the type cases */ 2000238106Sdes if(type == RESPONSE_TYPE_ANSWER) { 2001238106Sdes /* ANSWER type responses terminate the query algorithm, 2002238106Sdes * so they sent on their */ 2003238106Sdes if(verbosity >= VERB_DETAIL) { 2004238106Sdes verbose(VERB_DETAIL, "query response was %s", 2005238106Sdes FLAGS_GET_RCODE(iq->response->rep->flags) 2006238106Sdes ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER": 2007238106Sdes (iq->response->rep->an_numrrsets?"ANSWER": 2008238106Sdes "nodata ANSWER")); 2009238106Sdes } 2010238106Sdes /* if qtype is DS, check we have the right level of answer, 2011238106Sdes * like grandchild answer but we need the middle, reject it */ 2012238106Sdes if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 2013238106Sdes && !(iq->chase_flags&BIT_RD) 2014238106Sdes && iter_ds_toolow(iq->response, iq->dp) 2015249141Sdes && iter_dp_cangodown(&iq->qchase, iq->dp)) { 2016249141Sdes /* close down outstanding requests to be discarded */ 2017249141Sdes outbound_list_clear(&iq->outlist); 2018249141Sdes iq->num_current_queries = 0; 2019249141Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 2020249141Sdes qstate->env->detach_subs)); 2021249141Sdes (*qstate->env->detach_subs)(qstate); 2022249141Sdes iq->num_target_queries = 0; 2023238106Sdes return processDSNSFind(qstate, iq, id); 2024249141Sdes } 2025249141Sdes iter_dns_store(qstate->env, &iq->response->qinfo, 2026238106Sdes iq->response->rep, 0, qstate->prefetch_leeway, 2027238106Sdes iq->dp&&iq->dp->has_parent_side_NS, 2028249141Sdes qstate->region); 2029238106Sdes /* close down outstanding requests to be discarded */ 2030238106Sdes outbound_list_clear(&iq->outlist); 2031238106Sdes iq->num_current_queries = 0; 2032238106Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 2033238106Sdes qstate->env->detach_subs)); 2034238106Sdes (*qstate->env->detach_subs)(qstate); 2035238106Sdes iq->num_target_queries = 0; 2036238106Sdes if(qstate->reply) 2037238106Sdes sock_list_insert(&qstate->reply_origin, 2038238106Sdes &qstate->reply->addr, qstate->reply->addrlen, 2039238106Sdes qstate->region); 2040238106Sdes return final_state(iq); 2041238106Sdes } else if(type == RESPONSE_TYPE_REFERRAL) { 2042238106Sdes /* REFERRAL type responses get a reset of the 2043238106Sdes * delegation point, and back to the QUERYTARGETS_STATE. */ 2044238106Sdes verbose(VERB_DETAIL, "query response was REFERRAL"); 2045238106Sdes 2046238106Sdes /* if hardened, only store referral if we asked for it */ 2047238106Sdes if(!qstate->env->cfg->harden_referral_path || 2048238106Sdes ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS 2049238106Sdes && (qstate->query_flags&BIT_RD) 2050238106Sdes && !(qstate->query_flags&BIT_CD) 2051238106Sdes /* we know that all other NS rrsets are scrubbed 2052238106Sdes * away, thus on referral only one is left. 2053238106Sdes * see if that equals the query name... */ 2054238106Sdes && ( /* auth section, but sometimes in answer section*/ 2055238106Sdes reply_find_rrset_section_ns(iq->response->rep, 2056238106Sdes iq->qchase.qname, iq->qchase.qname_len, 2057238106Sdes LDNS_RR_TYPE_NS, iq->qchase.qclass) 2058238106Sdes || reply_find_rrset_section_an(iq->response->rep, 2059238106Sdes iq->qchase.qname, iq->qchase.qname_len, 2060238106Sdes LDNS_RR_TYPE_NS, iq->qchase.qclass) 2061238106Sdes ) 2062238106Sdes )) { 2063238106Sdes /* Store the referral under the current query */ 2064238106Sdes /* no prefetch-leeway, since its not the answer */ 2065249141Sdes iter_dns_store(qstate->env, &iq->response->qinfo, 2066249141Sdes iq->response->rep, 1, 0, 0, NULL); 2067238106Sdes if(iq->store_parent_NS) 2068238106Sdes iter_store_parentside_NS(qstate->env, 2069238106Sdes iq->response->rep); 2070238106Sdes if(qstate->env->neg_cache) 2071238106Sdes val_neg_addreferral(qstate->env->neg_cache, 2072238106Sdes iq->response->rep, iq->dp->name); 2073238106Sdes } 2074238106Sdes /* store parent-side-in-zone-glue, if directly queried for */ 2075238106Sdes if(iq->query_for_pside_glue && !iq->pside_glue) { 2076238106Sdes iq->pside_glue = reply_find_rrset(iq->response->rep, 2077238106Sdes iq->qchase.qname, iq->qchase.qname_len, 2078238106Sdes iq->qchase.qtype, iq->qchase.qclass); 2079238106Sdes if(iq->pside_glue) { 2080238106Sdes log_rrset_key(VERB_ALGO, "found parent-side " 2081238106Sdes "glue", iq->pside_glue); 2082238106Sdes iter_store_parentside_rrset(qstate->env, 2083238106Sdes iq->pside_glue); 2084238106Sdes } 2085238106Sdes } 2086238106Sdes 2087238106Sdes /* Reset the event state, setting the current delegation 2088238106Sdes * point to the referral. */ 2089238106Sdes iq->deleg_msg = iq->response; 2090238106Sdes iq->dp = delegpt_from_message(iq->response, qstate->region); 2091238106Sdes if(!iq->dp) 2092238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2093238106Sdes if(!cache_fill_missing(qstate->env, iq->qchase.qclass, 2094238106Sdes qstate->region, iq->dp)) 2095238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2096238106Sdes if(iq->store_parent_NS && query_dname_compare(iq->dp->name, 2097238106Sdes iq->store_parent_NS->name) == 0) 2098238106Sdes iter_merge_retry_counts(iq->dp, iq->store_parent_NS); 2099238106Sdes delegpt_log(VERB_ALGO, iq->dp); 2100238106Sdes /* Count this as a referral. */ 2101238106Sdes iq->referral_count++; 2102238106Sdes iq->sent_count = 0; 2103238106Sdes /* see if the next dp is a trust anchor, or a DS was sent 2104238106Sdes * along, indicating dnssec is expected for next zone */ 2105238106Sdes iq->dnssec_expected = iter_indicates_dnssec(qstate->env, 2106238106Sdes iq->dp, iq->response, iq->qchase.qclass); 2107238106Sdes /* if dnssec, validating then also fetch the key for the DS */ 2108238106Sdes if(iq->dnssec_expected && qstate->env->cfg->prefetch_key && 2109238106Sdes !(qstate->query_flags&BIT_CD)) 2110238106Sdes generate_dnskey_prefetch(qstate, iq, id); 2111238106Sdes 2112238106Sdes /* spawn off NS and addr to auth servers for the NS we just 2113238106Sdes * got in the referral. This gets authoritative answer 2114238106Sdes * (answer section trust level) rrset. 2115238106Sdes * right after, we detach the subs, answer goes to cache. */ 2116238106Sdes if(qstate->env->cfg->harden_referral_path) 2117238106Sdes generate_ns_check(qstate, iq, id); 2118238106Sdes 2119238106Sdes /* stop current outstanding queries. 2120238106Sdes * FIXME: should the outstanding queries be waited for and 2121238106Sdes * handled? Say by a subquery that inherits the outbound_entry. 2122238106Sdes */ 2123238106Sdes outbound_list_clear(&iq->outlist); 2124238106Sdes iq->num_current_queries = 0; 2125238106Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 2126238106Sdes qstate->env->detach_subs)); 2127238106Sdes (*qstate->env->detach_subs)(qstate); 2128238106Sdes iq->num_target_queries = 0; 2129238106Sdes verbose(VERB_ALGO, "cleared outbound list for next round"); 2130238106Sdes return next_state(iq, QUERYTARGETS_STATE); 2131238106Sdes } else if(type == RESPONSE_TYPE_CNAME) { 2132238106Sdes uint8_t* sname = NULL; 2133238106Sdes size_t snamelen = 0; 2134238106Sdes /* CNAME type responses get a query restart (i.e., get a 2135238106Sdes * reset of the query state and go back to INIT_REQUEST_STATE). 2136238106Sdes */ 2137238106Sdes verbose(VERB_DETAIL, "query response was CNAME"); 2138238106Sdes if(verbosity >= VERB_ALGO) 2139238106Sdes log_dns_msg("cname msg", &iq->response->qinfo, 2140238106Sdes iq->response->rep); 2141238106Sdes /* if qtype is DS, check we have the right level of answer, 2142238106Sdes * like grandchild answer but we need the middle, reject it */ 2143238106Sdes if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point 2144238106Sdes && !(iq->chase_flags&BIT_RD) 2145238106Sdes && iter_ds_toolow(iq->response, iq->dp) 2146249141Sdes && iter_dp_cangodown(&iq->qchase, iq->dp)) { 2147249141Sdes outbound_list_clear(&iq->outlist); 2148249141Sdes iq->num_current_queries = 0; 2149249141Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 2150249141Sdes qstate->env->detach_subs)); 2151249141Sdes (*qstate->env->detach_subs)(qstate); 2152249141Sdes iq->num_target_queries = 0; 2153238106Sdes return processDSNSFind(qstate, iq, id); 2154249141Sdes } 2155238106Sdes /* Process the CNAME response. */ 2156238106Sdes if(!handle_cname_response(qstate, iq, iq->response, 2157238106Sdes &sname, &snamelen)) 2158238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2159238106Sdes /* cache the CNAME response under the current query */ 2160238106Sdes /* NOTE : set referral=1, so that rrsets get stored but not 2161238106Sdes * the partial query answer (CNAME only). */ 2162238106Sdes /* prefetchleeway applied because this updates answer parts */ 2163249141Sdes iter_dns_store(qstate->env, &iq->response->qinfo, 2164238106Sdes iq->response->rep, 1, qstate->prefetch_leeway, 2165249141Sdes iq->dp&&iq->dp->has_parent_side_NS, NULL); 2166238106Sdes /* set the current request's qname to the new value. */ 2167238106Sdes iq->qchase.qname = sname; 2168238106Sdes iq->qchase.qname_len = snamelen; 2169238106Sdes /* Clear the query state, since this is a query restart. */ 2170238106Sdes iq->deleg_msg = NULL; 2171238106Sdes iq->dp = NULL; 2172238106Sdes iq->dsns_point = NULL; 2173238106Sdes /* Note the query restart. */ 2174238106Sdes iq->query_restart_count++; 2175238106Sdes iq->sent_count = 0; 2176238106Sdes 2177238106Sdes /* stop current outstanding queries. 2178238106Sdes * FIXME: should the outstanding queries be waited for and 2179238106Sdes * handled? Say by a subquery that inherits the outbound_entry. 2180238106Sdes */ 2181238106Sdes outbound_list_clear(&iq->outlist); 2182238106Sdes iq->num_current_queries = 0; 2183238106Sdes fptr_ok(fptr_whitelist_modenv_detach_subs( 2184238106Sdes qstate->env->detach_subs)); 2185238106Sdes (*qstate->env->detach_subs)(qstate); 2186238106Sdes iq->num_target_queries = 0; 2187238106Sdes if(qstate->reply) 2188238106Sdes sock_list_insert(&qstate->reply_origin, 2189238106Sdes &qstate->reply->addr, qstate->reply->addrlen, 2190238106Sdes qstate->region); 2191238106Sdes verbose(VERB_ALGO, "cleared outbound list for query restart"); 2192238106Sdes /* go to INIT_REQUEST_STATE for new qname. */ 2193238106Sdes return next_state(iq, INIT_REQUEST_STATE); 2194238106Sdes } else if(type == RESPONSE_TYPE_LAME) { 2195238106Sdes /* Cache the LAMEness. */ 2196238106Sdes verbose(VERB_DETAIL, "query response was %sLAME", 2197238106Sdes dnsseclame?"DNSSEC ":""); 2198238106Sdes if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2199238106Sdes log_err("mark lame: mismatch in qname and dpname"); 2200238106Sdes /* throwaway this reply below */ 2201238106Sdes } else if(qstate->reply) { 2202238106Sdes /* need addr for lameness cache, but we may have 2203238106Sdes * gotten this from cache, so test to be sure */ 2204238106Sdes if(!infra_set_lame(qstate->env->infra_cache, 2205238106Sdes &qstate->reply->addr, qstate->reply->addrlen, 2206238106Sdes iq->dp->name, iq->dp->namelen, 2207238106Sdes *qstate->env->now, dnsseclame, 0, 2208238106Sdes iq->qchase.qtype)) 2209238106Sdes log_err("mark host lame: out of memory"); 2210269257Sdes } 2211238106Sdes } else if(type == RESPONSE_TYPE_REC_LAME) { 2212238106Sdes /* Cache the LAMEness. */ 2213238106Sdes verbose(VERB_DETAIL, "query response REC_LAME: " 2214238106Sdes "recursive but not authoritative server"); 2215238106Sdes if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) { 2216238106Sdes log_err("mark rec_lame: mismatch in qname and dpname"); 2217238106Sdes /* throwaway this reply below */ 2218238106Sdes } else if(qstate->reply) { 2219238106Sdes /* need addr for lameness cache, but we may have 2220238106Sdes * gotten this from cache, so test to be sure */ 2221238106Sdes verbose(VERB_DETAIL, "mark as REC_LAME"); 2222238106Sdes if(!infra_set_lame(qstate->env->infra_cache, 2223238106Sdes &qstate->reply->addr, qstate->reply->addrlen, 2224238106Sdes iq->dp->name, iq->dp->namelen, 2225238106Sdes *qstate->env->now, 0, 1, iq->qchase.qtype)) 2226238106Sdes log_err("mark host lame: out of memory"); 2227238106Sdes } 2228238106Sdes } else if(type == RESPONSE_TYPE_THROWAWAY) { 2229238106Sdes /* LAME and THROWAWAY responses are handled the same way. 2230238106Sdes * In this case, the event is just sent directly back to 2231238106Sdes * the QUERYTARGETS_STATE without resetting anything, 2232238106Sdes * because, clearly, the next target must be tried. */ 2233238106Sdes verbose(VERB_DETAIL, "query response was THROWAWAY"); 2234238106Sdes } else { 2235238106Sdes log_warn("A query response came back with an unknown type: %d", 2236238106Sdes (int)type); 2237238106Sdes } 2238238106Sdes 2239238106Sdes /* LAME, THROWAWAY and "unknown" all end up here. 2240238106Sdes * Recycle to the QUERYTARGETS state to hopefully try a 2241238106Sdes * different target. */ 2242238106Sdes return next_state(iq, QUERYTARGETS_STATE); 2243238106Sdes} 2244238106Sdes 2245238106Sdes/** 2246238106Sdes * Return priming query results to interestes super querystates. 2247238106Sdes * 2248238106Sdes * Sets the delegation point and delegation message (not nonRD queries). 2249238106Sdes * This is a callback from walk_supers. 2250238106Sdes * 2251238106Sdes * @param qstate: priming query state that finished. 2252238106Sdes * @param id: module id. 2253238106Sdes * @param forq: the qstate for which priming has been done. 2254238106Sdes */ 2255238106Sdesstatic void 2256238106Sdesprime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq) 2257238106Sdes{ 2258238106Sdes struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2259238106Sdes struct delegpt* dp = NULL; 2260238106Sdes 2261238106Sdes log_assert(qstate->is_priming || foriq->wait_priming_stub); 2262238106Sdes log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2263238106Sdes /* Convert our response to a delegation point */ 2264238106Sdes dp = delegpt_from_message(qstate->return_msg, forq->region); 2265238106Sdes if(!dp) { 2266238106Sdes /* if there is no convertable delegation point, then 2267238106Sdes * the ANSWER type was (presumably) a negative answer. */ 2268238106Sdes verbose(VERB_ALGO, "prime response was not a positive " 2269238106Sdes "ANSWER; failing"); 2270238106Sdes foriq->dp = NULL; 2271238106Sdes foriq->state = QUERYTARGETS_STATE; 2272238106Sdes return; 2273238106Sdes } 2274238106Sdes 2275238106Sdes log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo); 2276238106Sdes delegpt_log(VERB_ALGO, dp); 2277238106Sdes foriq->dp = dp; 2278238106Sdes foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region); 2279238106Sdes if(!foriq->deleg_msg) { 2280238106Sdes log_err("copy prime response: out of memory"); 2281238106Sdes foriq->dp = NULL; 2282238106Sdes foriq->state = QUERYTARGETS_STATE; 2283238106Sdes return; 2284238106Sdes } 2285238106Sdes 2286238106Sdes /* root priming responses go to init stage 2, priming stub 2287238106Sdes * responses to to stage 3. */ 2288238106Sdes if(foriq->wait_priming_stub) { 2289238106Sdes foriq->state = INIT_REQUEST_3_STATE; 2290238106Sdes foriq->wait_priming_stub = 0; 2291238106Sdes } else foriq->state = INIT_REQUEST_2_STATE; 2292238106Sdes /* because we are finished, the parent will be reactivated */ 2293238106Sdes} 2294238106Sdes 2295238106Sdes/** 2296238106Sdes * This handles the response to a priming query. This is used to handle both 2297238106Sdes * root and stub priming responses. This is basically the equivalent of the 2298238106Sdes * QUERY_RESP_STATE, but will not handle CNAME responses and will treat 2299238106Sdes * REFERRALs as ANSWERS. It will also update and reactivate the originating 2300238106Sdes * event. 2301238106Sdes * 2302238106Sdes * @param qstate: query state. 2303238106Sdes * @param id: module id. 2304238106Sdes * @return true if the event needs more immediate processing, false if not. 2305238106Sdes * This state always returns false. 2306238106Sdes */ 2307238106Sdesstatic int 2308238106SdesprocessPrimeResponse(struct module_qstate* qstate, int id) 2309238106Sdes{ 2310238106Sdes struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2311238106Sdes enum response_type type; 2312238106Sdes iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */ 2313238106Sdes type = response_type_from_server( 2314238106Sdes (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd), 2315238106Sdes iq->response, &iq->qchase, iq->dp); 2316238106Sdes if(type == RESPONSE_TYPE_ANSWER) { 2317238106Sdes qstate->return_rcode = LDNS_RCODE_NOERROR; 2318238106Sdes qstate->return_msg = iq->response; 2319238106Sdes } else { 2320238106Sdes qstate->return_rcode = LDNS_RCODE_SERVFAIL; 2321238106Sdes qstate->return_msg = NULL; 2322238106Sdes } 2323238106Sdes 2324238106Sdes /* validate the root or stub after priming (if enabled). 2325238106Sdes * This is the same query as the prime query, but with validation. 2326238106Sdes * Now that we are primed, the additional queries that validation 2327238106Sdes * may need can be resolved, such as DLV. */ 2328238106Sdes if(qstate->env->cfg->harden_referral_path) { 2329238106Sdes struct module_qstate* subq = NULL; 2330238106Sdes log_nametypeclass(VERB_ALGO, "schedule prime validation", 2331238106Sdes qstate->qinfo.qname, qstate->qinfo.qtype, 2332238106Sdes qstate->qinfo.qclass); 2333238106Sdes if(!generate_sub_request(qstate->qinfo.qname, 2334238106Sdes qstate->qinfo.qname_len, qstate->qinfo.qtype, 2335238106Sdes qstate->qinfo.qclass, qstate, id, iq, 2336238106Sdes INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 2337238106Sdes verbose(VERB_ALGO, "could not generate prime check"); 2338238106Sdes } 2339238106Sdes generate_a_aaaa_check(qstate, iq, id); 2340238106Sdes } 2341238106Sdes 2342238106Sdes /* This event is finished. */ 2343238106Sdes qstate->ext_state[id] = module_finished; 2344238106Sdes return 0; 2345238106Sdes} 2346238106Sdes 2347238106Sdes/** 2348238106Sdes * Do final processing on responses to target queries. Events reach this 2349238106Sdes * state after the iterative resolution algorithm terminates. This state is 2350238106Sdes * responsible for reactiving the original event, and housekeeping related 2351238106Sdes * to received target responses (caching, updating the current delegation 2352238106Sdes * point, etc). 2353238106Sdes * Callback from walk_supers for every super state that is interested in 2354238106Sdes * the results from this query. 2355238106Sdes * 2356238106Sdes * @param qstate: query state. 2357238106Sdes * @param id: module id. 2358238106Sdes * @param forq: super query state. 2359238106Sdes */ 2360238106Sdesstatic void 2361238106SdesprocessTargetResponse(struct module_qstate* qstate, int id, 2362238106Sdes struct module_qstate* forq) 2363238106Sdes{ 2364238106Sdes struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2365238106Sdes struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2366238106Sdes struct ub_packed_rrset_key* rrset; 2367238106Sdes struct delegpt_ns* dpns; 2368238106Sdes log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR); 2369238106Sdes 2370238106Sdes foriq->state = QUERYTARGETS_STATE; 2371238106Sdes log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo); 2372238106Sdes log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo); 2373238106Sdes 2374238106Sdes /* check to see if parent event is still interested (in orig name). */ 2375238106Sdes if(!foriq->dp) { 2376238106Sdes verbose(VERB_ALGO, "subq: parent not interested, was reset"); 2377238106Sdes return; /* not interested anymore */ 2378238106Sdes } 2379238106Sdes dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname, 2380238106Sdes qstate->qinfo.qname_len); 2381238106Sdes if(!dpns) { 2382238106Sdes /* If not interested, just stop processing this event */ 2383238106Sdes verbose(VERB_ALGO, "subq: parent not interested anymore"); 2384238106Sdes /* could be because parent was jostled out of the cache, 2385238106Sdes and a new identical query arrived, that does not want it*/ 2386238106Sdes return; 2387238106Sdes } 2388238106Sdes 2389238106Sdes /* Tell the originating event that this target query has finished 2390238106Sdes * (regardless if it succeeded or not). */ 2391238106Sdes foriq->num_target_queries--; 2392238106Sdes 2393238106Sdes /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */ 2394238106Sdes if(iq->pside_glue) { 2395238106Sdes /* if the pside_glue is NULL, then it could not be found, 2396238106Sdes * the done_pside is already set when created and a cache 2397238106Sdes * entry created in processFinished so nothing to do here */ 2398238106Sdes log_rrset_key(VERB_ALGO, "add parentside glue to dp", 2399238106Sdes iq->pside_glue); 2400238106Sdes if(!delegpt_add_rrset(foriq->dp, forq->region, 2401238106Sdes iq->pside_glue, 1)) 2402238106Sdes log_err("out of memory adding pside glue"); 2403238106Sdes } 2404238106Sdes 2405238106Sdes /* This response is relevant to the current query, so we 2406238106Sdes * add (attempt to add, anyway) this target(s) and reactivate 2407238106Sdes * the original event. 2408238106Sdes * NOTE: we could only look for the AnswerRRset if the 2409238106Sdes * response type was ANSWER. */ 2410238106Sdes rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep); 2411238106Sdes if(rrset) { 2412238106Sdes /* if CNAMEs have been followed - add new NS to delegpt. */ 2413238106Sdes /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */ 2414238106Sdes if(!delegpt_find_ns(foriq->dp, rrset->rk.dname, 2415238106Sdes rrset->rk.dname_len)) { 2416238106Sdes /* if dpns->lame then set newcname ns lame too */ 2417238106Sdes if(!delegpt_add_ns(foriq->dp, forq->region, 2418269257Sdes rrset->rk.dname, dpns->lame)) 2419238106Sdes log_err("out of memory adding cnamed-ns"); 2420238106Sdes } 2421238106Sdes /* if dpns->lame then set the address(es) lame too */ 2422238106Sdes if(!delegpt_add_rrset(foriq->dp, forq->region, rrset, 2423269257Sdes dpns->lame)) 2424238106Sdes log_err("out of memory adding targets"); 2425238106Sdes verbose(VERB_ALGO, "added target response"); 2426238106Sdes delegpt_log(VERB_ALGO, foriq->dp); 2427238106Sdes } else { 2428238106Sdes verbose(VERB_ALGO, "iterator TargetResponse failed"); 2429238106Sdes dpns->resolved = 1; /* fail the target */ 2430238106Sdes } 2431238106Sdes} 2432238106Sdes 2433238106Sdes/** 2434238106Sdes * Process response for DS NS Find queries, that attempt to find the delegation 2435238106Sdes * point where we ask the DS query from. 2436238106Sdes * 2437238106Sdes * @param qstate: query state. 2438238106Sdes * @param id: module id. 2439238106Sdes * @param forq: super query state. 2440238106Sdes */ 2441238106Sdesstatic void 2442238106SdesprocessDSNSResponse(struct module_qstate* qstate, int id, 2443238106Sdes struct module_qstate* forq) 2444238106Sdes{ 2445238106Sdes struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2446238106Sdes 2447238106Sdes /* if the finished (iq->response) query has no NS set: continue 2448238106Sdes * up to look for the right dp; nothing to change, do DPNSstate */ 2449238106Sdes if(qstate->return_rcode != LDNS_RCODE_NOERROR) 2450238106Sdes return; /* seek further */ 2451238106Sdes /* find the NS RRset (without allowing CNAMEs) */ 2452238106Sdes if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname, 2453238106Sdes qstate->qinfo.qname_len, LDNS_RR_TYPE_NS, 2454238106Sdes qstate->qinfo.qclass)){ 2455238106Sdes return; /* seek further */ 2456238106Sdes } 2457238106Sdes 2458238106Sdes /* else, store as DP and continue at querytargets */ 2459238106Sdes foriq->state = QUERYTARGETS_STATE; 2460238106Sdes foriq->dp = delegpt_from_message(qstate->return_msg, forq->region); 2461238106Sdes if(!foriq->dp) { 2462238106Sdes log_err("out of memory in dsns dp alloc"); 2463238106Sdes return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */ 2464238106Sdes } 2465238106Sdes /* success, go query the querytargets in the new dp (and go down) */ 2466238106Sdes} 2467238106Sdes 2468238106Sdes/** 2469238106Sdes * Process response for qclass=ANY queries for a particular class. 2470238106Sdes * Append to result or error-exit. 2471238106Sdes * 2472238106Sdes * @param qstate: query state. 2473238106Sdes * @param id: module id. 2474238106Sdes * @param forq: super query state. 2475238106Sdes */ 2476238106Sdesstatic void 2477238106SdesprocessClassResponse(struct module_qstate* qstate, int id, 2478238106Sdes struct module_qstate* forq) 2479238106Sdes{ 2480238106Sdes struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id]; 2481238106Sdes struct dns_msg* from = qstate->return_msg; 2482238106Sdes log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo); 2483238106Sdes log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo); 2484238106Sdes if(qstate->return_rcode != LDNS_RCODE_NOERROR) { 2485238106Sdes /* cause servfail for qclass ANY query */ 2486238106Sdes foriq->response = NULL; 2487238106Sdes foriq->state = FINISHED_STATE; 2488238106Sdes return; 2489238106Sdes } 2490238106Sdes /* append result */ 2491238106Sdes if(!foriq->response) { 2492238106Sdes /* allocate the response: copy RCODE, sec_state */ 2493238106Sdes foriq->response = dns_copy_msg(from, forq->region); 2494238106Sdes if(!foriq->response) { 2495238106Sdes log_err("malloc failed for qclass ANY response"); 2496238106Sdes foriq->state = FINISHED_STATE; 2497238106Sdes return; 2498238106Sdes } 2499238106Sdes foriq->response->qinfo.qclass = forq->qinfo.qclass; 2500238106Sdes /* qclass ANY does not receive the AA flag on replies */ 2501238106Sdes foriq->response->rep->authoritative = 0; 2502238106Sdes } else { 2503238106Sdes struct dns_msg* to = foriq->response; 2504238106Sdes /* add _from_ this response _to_ existing collection */ 2505238106Sdes /* if there are records, copy RCODE */ 2506238106Sdes /* lower sec_state if this message is lower */ 2507238106Sdes if(from->rep->rrset_count != 0) { 2508238106Sdes size_t n = from->rep->rrset_count+to->rep->rrset_count; 2509238106Sdes struct ub_packed_rrset_key** dest, **d; 2510238106Sdes /* copy appropriate rcode */ 2511238106Sdes to->rep->flags = from->rep->flags; 2512238106Sdes /* copy rrsets */ 2513238106Sdes dest = regional_alloc(forq->region, sizeof(dest[0])*n); 2514238106Sdes if(!dest) { 2515238106Sdes log_err("malloc failed in collect ANY"); 2516238106Sdes foriq->state = FINISHED_STATE; 2517238106Sdes return; 2518238106Sdes } 2519238106Sdes d = dest; 2520238106Sdes /* copy AN */ 2521238106Sdes memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets 2522238106Sdes * sizeof(dest[0])); 2523238106Sdes dest += to->rep->an_numrrsets; 2524238106Sdes memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets 2525238106Sdes * sizeof(dest[0])); 2526238106Sdes dest += from->rep->an_numrrsets; 2527238106Sdes /* copy NS */ 2528238106Sdes memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets, 2529238106Sdes to->rep->ns_numrrsets * sizeof(dest[0])); 2530238106Sdes dest += to->rep->ns_numrrsets; 2531238106Sdes memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets, 2532238106Sdes from->rep->ns_numrrsets * sizeof(dest[0])); 2533238106Sdes dest += from->rep->ns_numrrsets; 2534238106Sdes /* copy AR */ 2535238106Sdes memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+ 2536238106Sdes to->rep->ns_numrrsets, 2537238106Sdes to->rep->ar_numrrsets * sizeof(dest[0])); 2538238106Sdes dest += to->rep->ar_numrrsets; 2539238106Sdes memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+ 2540238106Sdes from->rep->ns_numrrsets, 2541238106Sdes from->rep->ar_numrrsets * sizeof(dest[0])); 2542238106Sdes /* update counts */ 2543238106Sdes to->rep->rrsets = d; 2544238106Sdes to->rep->an_numrrsets += from->rep->an_numrrsets; 2545238106Sdes to->rep->ns_numrrsets += from->rep->ns_numrrsets; 2546238106Sdes to->rep->ar_numrrsets += from->rep->ar_numrrsets; 2547238106Sdes to->rep->rrset_count = n; 2548238106Sdes } 2549238106Sdes if(from->rep->security < to->rep->security) /* lowest sec */ 2550238106Sdes to->rep->security = from->rep->security; 2551238106Sdes if(from->rep->qdcount != 0) /* insert qd if appropriate */ 2552238106Sdes to->rep->qdcount = from->rep->qdcount; 2553238106Sdes if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */ 2554238106Sdes to->rep->ttl = from->rep->ttl; 2555238106Sdes if(from->rep->prefetch_ttl < to->rep->prefetch_ttl) 2556238106Sdes to->rep->prefetch_ttl = from->rep->prefetch_ttl; 2557238106Sdes } 2558238106Sdes /* are we done? */ 2559238106Sdes foriq->num_current_queries --; 2560238106Sdes if(foriq->num_current_queries == 0) 2561238106Sdes foriq->state = FINISHED_STATE; 2562238106Sdes} 2563238106Sdes 2564238106Sdes/** 2565238106Sdes * Collect class ANY responses and make them into one response. This 2566238106Sdes * state is started and it creates queries for all classes (that have 2567238106Sdes * root hints). The answers are then collected. 2568238106Sdes * 2569238106Sdes * @param qstate: query state. 2570238106Sdes * @param id: module id. 2571238106Sdes * @return true if the event needs more immediate processing, false if not. 2572238106Sdes */ 2573238106Sdesstatic int 2574238106SdesprocessCollectClass(struct module_qstate* qstate, int id) 2575238106Sdes{ 2576238106Sdes struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2577238106Sdes struct module_qstate* subq; 2578238106Sdes /* If qchase.qclass == 0 then send out queries for all classes. 2579238106Sdes * Otherwise, do nothing (wait for all answers to arrive and the 2580238106Sdes * processClassResponse to put them together, and that moves us 2581238106Sdes * towards the Finished state when done. */ 2582238106Sdes if(iq->qchase.qclass == 0) { 2583238106Sdes uint16_t c = 0; 2584238106Sdes iq->qchase.qclass = LDNS_RR_CLASS_ANY; 2585238106Sdes while(iter_get_next_root(qstate->env->hints, 2586238106Sdes qstate->env->fwds, &c)) { 2587238106Sdes /* generate query for this class */ 2588238106Sdes log_nametypeclass(VERB_ALGO, "spawn collect query", 2589238106Sdes qstate->qinfo.qname, qstate->qinfo.qtype, c); 2590238106Sdes if(!generate_sub_request(qstate->qinfo.qname, 2591238106Sdes qstate->qinfo.qname_len, qstate->qinfo.qtype, 2592238106Sdes c, qstate, id, iq, INIT_REQUEST_STATE, 2593238106Sdes FINISHED_STATE, &subq, 2594238106Sdes (int)!(qstate->query_flags&BIT_CD))) { 2595238106Sdes return error_response(qstate, id, 2596238106Sdes LDNS_RCODE_SERVFAIL); 2597238106Sdes } 2598238106Sdes /* ignore subq, no special init required */ 2599238106Sdes iq->num_current_queries ++; 2600238106Sdes if(c == 0xffff) 2601238106Sdes break; 2602238106Sdes else c++; 2603238106Sdes } 2604238106Sdes /* if no roots are configured at all, return */ 2605238106Sdes if(iq->num_current_queries == 0) { 2606238106Sdes verbose(VERB_ALGO, "No root hints or fwds, giving up " 2607238106Sdes "on qclass ANY"); 2608238106Sdes return error_response(qstate, id, LDNS_RCODE_REFUSED); 2609238106Sdes } 2610238106Sdes /* return false, wait for queries to return */ 2611238106Sdes } 2612238106Sdes /* if woke up here because of an answer, wait for more answers */ 2613238106Sdes return 0; 2614238106Sdes} 2615238106Sdes 2616238106Sdes/** 2617238106Sdes * This handles the final state for first-tier responses (i.e., responses to 2618238106Sdes * externally generated queries). 2619238106Sdes * 2620238106Sdes * @param qstate: query state. 2621238106Sdes * @param iq: iterator query state. 2622238106Sdes * @param id: module id. 2623238106Sdes * @return true if the event needs more processing, false if not. Since this 2624238106Sdes * is the final state for an event, it always returns false. 2625238106Sdes */ 2626238106Sdesstatic int 2627238106SdesprocessFinished(struct module_qstate* qstate, struct iter_qstate* iq, 2628238106Sdes int id) 2629238106Sdes{ 2630238106Sdes log_query_info(VERB_QUERY, "finishing processing for", 2631238106Sdes &qstate->qinfo); 2632238106Sdes 2633238106Sdes /* store negative cache element for parent side glue. */ 2634238106Sdes if(iq->query_for_pside_glue && !iq->pside_glue) 2635238106Sdes iter_store_parentside_neg(qstate->env, &qstate->qinfo, 2636238106Sdes iq->deleg_msg?iq->deleg_msg->rep: 2637238106Sdes (iq->response?iq->response->rep:NULL)); 2638238106Sdes if(!iq->response) { 2639238106Sdes verbose(VERB_ALGO, "No response is set, servfail"); 2640238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2641238106Sdes } 2642238106Sdes 2643238106Sdes /* Make sure that the RA flag is set (since the presence of 2644238106Sdes * this module means that recursion is available) */ 2645238106Sdes iq->response->rep->flags |= BIT_RA; 2646238106Sdes 2647238106Sdes /* Clear the AA flag */ 2648238106Sdes /* FIXME: does this action go here or in some other module? */ 2649238106Sdes iq->response->rep->flags &= ~BIT_AA; 2650238106Sdes 2651238106Sdes /* make sure QR flag is on */ 2652238106Sdes iq->response->rep->flags |= BIT_QR; 2653238106Sdes 2654238106Sdes /* we have finished processing this query */ 2655238106Sdes qstate->ext_state[id] = module_finished; 2656238106Sdes 2657238106Sdes /* TODO: we are using a private TTL, trim the response. */ 2658238106Sdes /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */ 2659238106Sdes 2660238106Sdes /* prepend any items we have accumulated */ 2661238106Sdes if(iq->an_prepend_list || iq->ns_prepend_list) { 2662238106Sdes if(!iter_prepend(iq, iq->response, qstate->region)) { 2663238106Sdes log_err("prepend rrsets: out of memory"); 2664238106Sdes return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2665238106Sdes } 2666238106Sdes /* reset the query name back */ 2667238106Sdes iq->response->qinfo = qstate->qinfo; 2668238106Sdes /* the security state depends on the combination */ 2669238106Sdes iq->response->rep->security = sec_status_unchecked; 2670238106Sdes /* store message with the finished prepended items, 2671238106Sdes * but only if we did recursion. The nonrecursion referral 2672238106Sdes * from cache does not need to be stored in the msg cache. */ 2673238106Sdes if(qstate->query_flags&BIT_RD) { 2674249141Sdes iter_dns_store(qstate->env, &qstate->qinfo, 2675238106Sdes iq->response->rep, 0, qstate->prefetch_leeway, 2676238106Sdes iq->dp&&iq->dp->has_parent_side_NS, 2677249141Sdes qstate->region); 2678238106Sdes } 2679238106Sdes } 2680238106Sdes qstate->return_rcode = LDNS_RCODE_NOERROR; 2681238106Sdes qstate->return_msg = iq->response; 2682238106Sdes return 0; 2683238106Sdes} 2684238106Sdes 2685238106Sdes/* 2686238106Sdes * Return priming query results to interestes super querystates. 2687238106Sdes * 2688238106Sdes * Sets the delegation point and delegation message (not nonRD queries). 2689238106Sdes * This is a callback from walk_supers. 2690238106Sdes * 2691238106Sdes * @param qstate: query state that finished. 2692238106Sdes * @param id: module id. 2693238106Sdes * @param super: the qstate to inform. 2694238106Sdes */ 2695238106Sdesvoid 2696238106Sdesiter_inform_super(struct module_qstate* qstate, int id, 2697238106Sdes struct module_qstate* super) 2698238106Sdes{ 2699238106Sdes if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY) 2700238106Sdes processClassResponse(qstate, id, super); 2701238106Sdes else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) 2702238106Sdes super->minfo[id])->state == DSNS_FIND_STATE) 2703238106Sdes processDSNSResponse(qstate, id, super); 2704238106Sdes else if(qstate->return_rcode != LDNS_RCODE_NOERROR) 2705238106Sdes error_supers(qstate, id, super); 2706238106Sdes else if(qstate->is_priming) 2707238106Sdes prime_supers(qstate, id, super); 2708238106Sdes else processTargetResponse(qstate, id, super); 2709238106Sdes} 2710238106Sdes 2711238106Sdes/** 2712238106Sdes * Handle iterator state. 2713238106Sdes * Handle events. This is the real processing loop for events, responsible 2714238106Sdes * for moving events through the various states. If a processing method 2715238106Sdes * returns true, then it will be advanced to the next state. If false, then 2716238106Sdes * processing will stop. 2717238106Sdes * 2718238106Sdes * @param qstate: query state. 2719238106Sdes * @param ie: iterator shared global environment. 2720238106Sdes * @param iq: iterator query state. 2721238106Sdes * @param id: module id. 2722238106Sdes */ 2723238106Sdesstatic void 2724238106Sdesiter_handle(struct module_qstate* qstate, struct iter_qstate* iq, 2725238106Sdes struct iter_env* ie, int id) 2726238106Sdes{ 2727238106Sdes int cont = 1; 2728238106Sdes while(cont) { 2729238106Sdes verbose(VERB_ALGO, "iter_handle processing q with state %s", 2730238106Sdes iter_state_to_string(iq->state)); 2731238106Sdes switch(iq->state) { 2732238106Sdes case INIT_REQUEST_STATE: 2733238106Sdes cont = processInitRequest(qstate, iq, ie, id); 2734238106Sdes break; 2735238106Sdes case INIT_REQUEST_2_STATE: 2736238106Sdes cont = processInitRequest2(qstate, iq, id); 2737238106Sdes break; 2738238106Sdes case INIT_REQUEST_3_STATE: 2739238106Sdes cont = processInitRequest3(qstate, iq, id); 2740238106Sdes break; 2741238106Sdes case QUERYTARGETS_STATE: 2742238106Sdes cont = processQueryTargets(qstate, iq, ie, id); 2743238106Sdes break; 2744238106Sdes case QUERY_RESP_STATE: 2745238106Sdes cont = processQueryResponse(qstate, iq, id); 2746238106Sdes break; 2747238106Sdes case PRIME_RESP_STATE: 2748238106Sdes cont = processPrimeResponse(qstate, id); 2749238106Sdes break; 2750238106Sdes case COLLECT_CLASS_STATE: 2751238106Sdes cont = processCollectClass(qstate, id); 2752238106Sdes break; 2753238106Sdes case DSNS_FIND_STATE: 2754238106Sdes cont = processDSNSFind(qstate, iq, id); 2755238106Sdes break; 2756238106Sdes case FINISHED_STATE: 2757238106Sdes cont = processFinished(qstate, iq, id); 2758238106Sdes break; 2759238106Sdes default: 2760238106Sdes log_warn("iterator: invalid state: %d", 2761238106Sdes iq->state); 2762238106Sdes cont = 0; 2763238106Sdes break; 2764238106Sdes } 2765238106Sdes } 2766238106Sdes} 2767238106Sdes 2768238106Sdes/** 2769238106Sdes * This is the primary entry point for processing request events. Note that 2770238106Sdes * this method should only be used by external modules. 2771238106Sdes * @param qstate: query state. 2772238106Sdes * @param ie: iterator shared global environment. 2773238106Sdes * @param iq: iterator query state. 2774238106Sdes * @param id: module id. 2775238106Sdes */ 2776238106Sdesstatic void 2777238106Sdesprocess_request(struct module_qstate* qstate, struct iter_qstate* iq, 2778238106Sdes struct iter_env* ie, int id) 2779238106Sdes{ 2780238106Sdes /* external requests start in the INIT state, and finish using the 2781238106Sdes * FINISHED state. */ 2782238106Sdes iq->state = INIT_REQUEST_STATE; 2783238106Sdes iq->final_state = FINISHED_STATE; 2784238106Sdes verbose(VERB_ALGO, "process_request: new external request event"); 2785238106Sdes iter_handle(qstate, iq, ie, id); 2786238106Sdes} 2787238106Sdes 2788238106Sdes/** process authoritative server reply */ 2789238106Sdesstatic void 2790238106Sdesprocess_response(struct module_qstate* qstate, struct iter_qstate* iq, 2791238106Sdes struct iter_env* ie, int id, struct outbound_entry* outbound, 2792238106Sdes enum module_ev event) 2793238106Sdes{ 2794238106Sdes struct msg_parse* prs; 2795238106Sdes struct edns_data edns; 2796269257Sdes sldns_buffer* pkt; 2797238106Sdes 2798238106Sdes verbose(VERB_ALGO, "process_response: new external response event"); 2799238106Sdes iq->response = NULL; 2800238106Sdes iq->state = QUERY_RESP_STATE; 2801238106Sdes if(event == module_event_noreply || event == module_event_error) { 2802238106Sdes goto handle_it; 2803238106Sdes } 2804238106Sdes if( (event != module_event_reply && event != module_event_capsfail) 2805238106Sdes || !qstate->reply) { 2806238106Sdes log_err("Bad event combined with response"); 2807238106Sdes outbound_list_remove(&iq->outlist, outbound); 2808238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2809238106Sdes return; 2810238106Sdes } 2811238106Sdes 2812238106Sdes /* parse message */ 2813238106Sdes prs = (struct msg_parse*)regional_alloc(qstate->env->scratch, 2814238106Sdes sizeof(struct msg_parse)); 2815238106Sdes if(!prs) { 2816238106Sdes log_err("out of memory on incoming message"); 2817238106Sdes /* like packet got dropped */ 2818238106Sdes goto handle_it; 2819238106Sdes } 2820238106Sdes memset(prs, 0, sizeof(*prs)); 2821238106Sdes memset(&edns, 0, sizeof(edns)); 2822238106Sdes pkt = qstate->reply->c->buffer; 2823269257Sdes sldns_buffer_set_position(pkt, 0); 2824238106Sdes if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) { 2825238106Sdes verbose(VERB_ALGO, "parse error on reply packet"); 2826238106Sdes goto handle_it; 2827238106Sdes } 2828238106Sdes /* edns is not examined, but removed from message to help cache */ 2829238106Sdes if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR) 2830238106Sdes goto handle_it; 2831238106Sdes /* remove CD-bit, we asked for in case we handle validation ourself */ 2832238106Sdes prs->flags &= ~BIT_CD; 2833238106Sdes 2834238106Sdes /* normalize and sanitize: easy to delete items from linked lists */ 2835238106Sdes if(!scrub_message(pkt, prs, &iq->qchase, iq->dp->name, 2836238106Sdes qstate->env->scratch, qstate->env, ie)) 2837238106Sdes goto handle_it; 2838238106Sdes 2839238106Sdes /* allocate response dns_msg in region */ 2840238106Sdes iq->response = dns_alloc_msg(pkt, prs, qstate->region); 2841238106Sdes if(!iq->response) 2842238106Sdes goto handle_it; 2843238106Sdes log_query_info(VERB_DETAIL, "response for", &qstate->qinfo); 2844238106Sdes log_name_addr(VERB_DETAIL, "reply from", iq->dp->name, 2845238106Sdes &qstate->reply->addr, qstate->reply->addrlen); 2846238106Sdes if(verbosity >= VERB_ALGO) 2847238106Sdes log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo, 2848238106Sdes iq->response->rep); 2849238106Sdes 2850238106Sdes if(event == module_event_capsfail) { 2851238106Sdes if(!iq->caps_fallback) { 2852238106Sdes /* start fallback */ 2853238106Sdes iq->caps_fallback = 1; 2854238106Sdes iq->caps_server = 0; 2855238106Sdes iq->caps_reply = iq->response->rep; 2856238106Sdes iq->state = QUERYTARGETS_STATE; 2857238106Sdes iq->num_current_queries--; 2858238106Sdes verbose(VERB_DETAIL, "Capsforid: starting fallback"); 2859238106Sdes goto handle_it; 2860238106Sdes } else { 2861238106Sdes /* check if reply is the same, otherwise, fail */ 2862238106Sdes if(!reply_equal(iq->response->rep, iq->caps_reply, 2863269257Sdes qstate->env->scratch)) { 2864238106Sdes verbose(VERB_DETAIL, "Capsforid fallback: " 2865238106Sdes "getting different replies, failed"); 2866238106Sdes outbound_list_remove(&iq->outlist, outbound); 2867238106Sdes (void)error_response(qstate, id, 2868238106Sdes LDNS_RCODE_SERVFAIL); 2869238106Sdes return; 2870238106Sdes } 2871238106Sdes /* continue the fallback procedure at next server */ 2872238106Sdes iq->caps_server++; 2873238106Sdes iq->state = QUERYTARGETS_STATE; 2874238106Sdes iq->num_current_queries--; 2875238106Sdes verbose(VERB_DETAIL, "Capsforid: reply is equal. " 2876238106Sdes "go to next fallback"); 2877238106Sdes goto handle_it; 2878238106Sdes } 2879238106Sdes } 2880238106Sdes iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */ 2881238106Sdes 2882238106Sdeshandle_it: 2883238106Sdes outbound_list_remove(&iq->outlist, outbound); 2884238106Sdes iter_handle(qstate, iq, ie, id); 2885238106Sdes} 2886238106Sdes 2887238106Sdesvoid 2888238106Sdesiter_operate(struct module_qstate* qstate, enum module_ev event, int id, 2889238106Sdes struct outbound_entry* outbound) 2890238106Sdes{ 2891238106Sdes struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id]; 2892238106Sdes struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id]; 2893238106Sdes verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s", 2894238106Sdes id, strextstate(qstate->ext_state[id]), strmodulevent(event)); 2895238106Sdes if(iq) log_query_info(VERB_QUERY, "iterator operate: query", 2896238106Sdes &qstate->qinfo); 2897238106Sdes if(iq && qstate->qinfo.qname != iq->qchase.qname) 2898238106Sdes log_query_info(VERB_QUERY, "iterator operate: chased to", 2899238106Sdes &iq->qchase); 2900238106Sdes 2901238106Sdes /* perform iterator state machine */ 2902238106Sdes if((event == module_event_new || event == module_event_pass) && 2903238106Sdes iq == NULL) { 2904238106Sdes if(!iter_new(qstate, id)) { 2905238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2906238106Sdes return; 2907238106Sdes } 2908238106Sdes iq = (struct iter_qstate*)qstate->minfo[id]; 2909238106Sdes process_request(qstate, iq, ie, id); 2910238106Sdes return; 2911238106Sdes } 2912238106Sdes if(iq && event == module_event_pass) { 2913238106Sdes iter_handle(qstate, iq, ie, id); 2914238106Sdes return; 2915238106Sdes } 2916238106Sdes if(iq && outbound) { 2917238106Sdes process_response(qstate, iq, ie, id, outbound, event); 2918238106Sdes return; 2919238106Sdes } 2920238106Sdes if(event == module_event_error) { 2921238106Sdes verbose(VERB_ALGO, "got called with event error, giving up"); 2922238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2923238106Sdes return; 2924238106Sdes } 2925238106Sdes 2926238106Sdes log_err("bad event for iterator"); 2927238106Sdes (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL); 2928238106Sdes} 2929238106Sdes 2930238106Sdesvoid 2931238106Sdesiter_clear(struct module_qstate* qstate, int id) 2932238106Sdes{ 2933238106Sdes struct iter_qstate* iq; 2934238106Sdes if(!qstate) 2935238106Sdes return; 2936238106Sdes iq = (struct iter_qstate*)qstate->minfo[id]; 2937238106Sdes if(iq) { 2938238106Sdes outbound_list_clear(&iq->outlist); 2939275854Sdelphij if(iq->target_count && --iq->target_count[0] == 0) 2940275854Sdelphij free(iq->target_count); 2941238106Sdes iq->num_current_queries = 0; 2942238106Sdes } 2943238106Sdes qstate->minfo[id] = NULL; 2944238106Sdes} 2945238106Sdes 2946238106Sdessize_t 2947238106Sdesiter_get_mem(struct module_env* env, int id) 2948238106Sdes{ 2949238106Sdes struct iter_env* ie = (struct iter_env*)env->modinfo[id]; 2950238106Sdes if(!ie) 2951238106Sdes return 0; 2952238106Sdes return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1) 2953238106Sdes + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv); 2954238106Sdes} 2955238106Sdes 2956238106Sdes/** 2957238106Sdes * The iterator function block 2958238106Sdes */ 2959238106Sdesstatic struct module_func_block iter_block = { 2960238106Sdes "iterator", 2961238106Sdes &iter_init, &iter_deinit, &iter_operate, &iter_inform_super, 2962238106Sdes &iter_clear, &iter_get_mem 2963238106Sdes}; 2964238106Sdes 2965238106Sdesstruct module_func_block* 2966238106Sdesiter_get_funcblock(void) 2967238106Sdes{ 2968238106Sdes return &iter_block; 2969238106Sdes} 2970238106Sdes 2971238106Sdesconst char* 2972238106Sdesiter_state_to_string(enum iter_state state) 2973238106Sdes{ 2974238106Sdes switch (state) 2975238106Sdes { 2976238106Sdes case INIT_REQUEST_STATE : 2977238106Sdes return "INIT REQUEST STATE"; 2978238106Sdes case INIT_REQUEST_2_STATE : 2979238106Sdes return "INIT REQUEST STATE (stage 2)"; 2980238106Sdes case INIT_REQUEST_3_STATE: 2981238106Sdes return "INIT REQUEST STATE (stage 3)"; 2982238106Sdes case QUERYTARGETS_STATE : 2983238106Sdes return "QUERY TARGETS STATE"; 2984238106Sdes case PRIME_RESP_STATE : 2985238106Sdes return "PRIME RESPONSE STATE"; 2986238106Sdes case COLLECT_CLASS_STATE : 2987238106Sdes return "COLLECT CLASS STATE"; 2988238106Sdes case DSNS_FIND_STATE : 2989238106Sdes return "DSNS FIND STATE"; 2990238106Sdes case QUERY_RESP_STATE : 2991238106Sdes return "QUERY RESPONSE STATE"; 2992238106Sdes case FINISHED_STATE : 2993238106Sdes return "FINISHED RESPONSE STATE"; 2994238106Sdes default : 2995238106Sdes return "UNKNOWN ITER STATE"; 2996238106Sdes } 2997238106Sdes} 2998238106Sdes 2999238106Sdesint 3000238106Sdesiter_state_is_responsestate(enum iter_state s) 3001238106Sdes{ 3002238106Sdes switch(s) { 3003238106Sdes case INIT_REQUEST_STATE : 3004238106Sdes case INIT_REQUEST_2_STATE : 3005238106Sdes case INIT_REQUEST_3_STATE : 3006238106Sdes case QUERYTARGETS_STATE : 3007238106Sdes case COLLECT_CLASS_STATE : 3008238106Sdes return 0; 3009238106Sdes default: 3010238106Sdes break; 3011238106Sdes } 3012238106Sdes return 1; 3013238106Sdes} 3014