2 * iterator/iterator.c - iterative resolver DNS query response module
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 * This file contains a module that performs recusive iterative DNS query
44 #include "iterator/iterator.h"
45 #include "iterator/iter_utils.h"
46 #include "iterator/iter_hints.h"
47 #include "iterator/iter_fwd.h"
48 #include "iterator/iter_donotq.h"
49 #include "iterator/iter_delegpt.h"
50 #include "iterator/iter_resptype.h"
51 #include "iterator/iter_scrub.h"
52 #include "iterator/iter_priv.h"
53 #include "validator/val_neg.h"
54 #include "services/cache/dns.h"
55 #include "services/cache/infra.h"
56 #include "util/module.h"
57 #include "util/netevent.h"
58 #include "util/net_help.h"
59 #include "util/regional.h"
60 #include "util/data/dname.h"
61 #include "util/data/msgencode.h"
62 #include "util/fptr_wlist.h"
63 #include "util/config_file.h"
64 #include "util/random.h"
65 #include "sldns/rrdef.h"
66 #include "sldns/wire2str.h"
67 #include "sldns/str2wire.h"
68 #include "sldns/parseutil.h"
69 #include "sldns/sbuffer.h"
72 iter_init(struct module_env* env, int id)
74 struct iter_env* iter_env = (struct iter_env*)calloc(1,
75 sizeof(struct iter_env));
77 log_err("malloc failure");
80 env->modinfo[id] = (void*)iter_env;
81 if(!iter_apply_cfg(iter_env, env->cfg)) {
82 log_err("iterator: could not apply configuration settings.");
89 /** delete caps_whitelist element */
91 caps_free(struct rbnode_t* n, void* ATTR_UNUSED(d))
94 free(((struct name_tree_node*)n)->name);
100 iter_deinit(struct module_env* env, int id)
102 struct iter_env* iter_env;
103 if(!env || !env->modinfo[id])
105 iter_env = (struct iter_env*)env->modinfo[id];
106 free(iter_env->target_fetch_policy);
107 priv_delete(iter_env->priv);
108 donotq_delete(iter_env->donotq);
109 if(iter_env->caps_white) {
110 traverse_postorder(iter_env->caps_white, caps_free, NULL);
111 free(iter_env->caps_white);
114 env->modinfo[id] = NULL;
117 /** new query for iterator */
119 iter_new(struct module_qstate* qstate, int id)
121 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc(
122 qstate->region, sizeof(struct iter_qstate));
123 qstate->minfo[id] = iq;
126 memset(iq, 0, sizeof(*iq));
127 iq->state = INIT_REQUEST_STATE;
128 iq->final_state = FINISHED_STATE;
129 iq->an_prepend_list = NULL;
130 iq->an_prepend_last = NULL;
131 iq->ns_prepend_list = NULL;
132 iq->ns_prepend_last = NULL;
135 iq->num_target_queries = 0;
136 iq->num_current_queries = 0;
137 iq->query_restart_count = 0;
138 iq->referral_count = 0;
140 iq->ratelimit_ok = 0;
141 iq->target_count = NULL;
142 iq->wait_priming_stub = 0;
143 iq->refetch_glue = 0;
144 iq->dnssec_expected = 0;
145 iq->dnssec_lame_query = 0;
146 iq->chase_flags = qstate->query_flags;
147 /* Start with the (current) qname. */
148 iq->qchase = qstate->qinfo;
149 outbound_list_init(&iq->outlist);
150 iq->minimise_count = 0;
151 iq->minimise_timeout_count = 0;
152 if (qstate->env->cfg->qname_minimisation)
153 iq->minimisation_state = INIT_MINIMISE_STATE;
155 iq->minimisation_state = DONOT_MINIMISE_STATE;
157 memset(&iq->qinfo_out, 0, sizeof(struct query_info));
162 * Transition to the next state. This can be used to advance a currently
163 * processing event. It cannot be used to reactivate a forEvent.
165 * @param iq: iterator query state
166 * @param nextstate The state to transition to.
167 * @return true. This is so this can be called as the return value for the
168 * actual process*State() methods. (Transitioning to the next state
169 * implies further processing).
172 next_state(struct iter_qstate* iq, enum iter_state nextstate)
174 /* If transitioning to a "response" state, make sure that there is a
176 if(iter_state_is_responsestate(nextstate)) {
177 if(iq->response == NULL) {
178 log_err("transitioning to response state sans "
182 iq->state = nextstate;
187 * Transition an event to its final state. Final states always either return
188 * a result up the module chain, or reactivate a dependent event. Which
189 * final state to transition to is set in the module state for the event when
190 * it was created, and depends on the original purpose of the event.
192 * The response is stored in the qstate->buf buffer.
194 * @param iq: iterator query state
195 * @return false. This is so this method can be used as the return value for
196 * the processState methods. (Transitioning to the final state
199 final_state(struct iter_qstate* iq)
201 return next_state(iq, iq->final_state);
205 * Callback routine to handle errors in parent query states
206 * @param qstate: query state that failed.
207 * @param id: module id.
208 * @param super: super state.
211 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
213 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
215 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
216 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
217 /* mark address as failed. */
218 struct delegpt_ns* dpns = NULL;
219 super_iq->num_target_queries--;
221 dpns = delegpt_find_ns(super_iq->dp,
222 qstate->qinfo.qname, qstate->qinfo.qname_len);
225 verbose(VERB_ALGO, "subq error, but not interested");
226 log_query_info(VERB_ALGO, "superq", &super->qinfo);
228 delegpt_log(VERB_ALGO, super_iq->dp);
232 /* see if the failure did get (parent-lame) info */
233 if(!cache_fill_missing(super->env,
234 super_iq->qchase.qclass, super->region,
236 log_err("out of memory adding missing");
238 dpns->resolved = 1; /* mark as failed */
240 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
241 /* prime failed to get delegation */
244 /* evaluate targets again */
245 super_iq->state = QUERYTARGETS_STATE;
246 /* super becomes runnable, and will process this change */
250 * Return an error to the client
251 * @param qstate: our query state
252 * @param id: module id
253 * @param rcode: error code (DNS errcode).
254 * @return: 0 for use by caller, to make notation easy, like:
255 * return error_response(..).
258 error_response(struct module_qstate* qstate, int id, int rcode)
260 verbose(VERB_QUERY, "return error response %s",
261 sldns_lookup_by_id(sldns_rcodes, rcode)?
262 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
263 qstate->return_rcode = rcode;
264 qstate->return_msg = NULL;
265 qstate->ext_state[id] = module_finished;
270 * Return an error to the client and cache the error code in the
271 * message cache (so per qname, qtype, qclass).
272 * @param qstate: our query state
273 * @param id: module id
274 * @param rcode: error code (DNS errcode).
275 * @return: 0 for use by caller, to make notation easy, like:
276 * return error_response(..).
279 error_response_cache(struct module_qstate* qstate, int id, int rcode)
282 struct reply_info err;
283 if(qstate->prefetch_leeway > NORR_TTL) {
284 verbose(VERB_ALGO, "error response for prefetch in cache");
285 /* attempt to adjust the cache entry prefetch */
286 if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,
287 NORR_TTL, qstate->query_flags))
288 return error_response(qstate, id, rcode);
289 /* if that fails (not in cache), fall through to store err */
291 memset(&err, 0, sizeof(err));
292 err.flags = (uint16_t)(BIT_QR | BIT_RA);
293 FLAGS_SET_RCODE(err.flags, rcode);
296 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
297 /* do not waste time trying to validate this servfail */
298 err.security = sec_status_indeterminate;
299 verbose(VERB_ALGO, "store error response in message cache");
300 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL,
301 qstate->query_flags);
302 return error_response(qstate, id, rcode);
305 /** check if prepend item is duplicate item */
307 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
308 struct ub_packed_rrset_key* dup)
311 for(i=0; i<to; i++) {
312 if(sets[i]->rk.type == dup->rk.type &&
313 sets[i]->rk.rrset_class == dup->rk.rrset_class &&
314 sets[i]->rk.dname_len == dup->rk.dname_len &&
315 query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
322 /** prepend the prepend list in the answer and authority section of dns_msg */
324 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
325 struct regional* region)
327 struct iter_prep_list* p;
328 struct ub_packed_rrset_key** sets;
329 size_t num_an = 0, num_ns = 0;;
330 for(p = iq->an_prepend_list; p; p = p->next)
332 for(p = iq->ns_prepend_list; p; p = p->next)
334 if(num_an + num_ns == 0)
336 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
337 if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX ||
338 msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */
339 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) *
340 sizeof(struct ub_packed_rrset_key*));
345 for(p = iq->an_prepend_list; p; p = p->next) {
346 sets[num_an++] = p->rrset;
348 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
349 sizeof(struct ub_packed_rrset_key*));
352 for(p = iq->ns_prepend_list; p; p = p->next) {
353 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
354 num_ns, p->rrset) || prepend_is_duplicate(
355 msg->rep->rrsets+msg->rep->an_numrrsets,
356 msg->rep->ns_numrrsets, p->rrset))
358 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
360 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
361 msg->rep->rrsets + msg->rep->an_numrrsets,
362 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
363 sizeof(struct ub_packed_rrset_key*));
365 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
366 * this is what recursors should give. */
367 msg->rep->rrset_count += num_an + num_ns;
368 msg->rep->an_numrrsets += num_an;
369 msg->rep->ns_numrrsets += num_ns;
370 msg->rep->rrsets = sets;
375 * Add rrset to ANSWER prepend list
376 * @param qstate: query state.
377 * @param iq: iterator query state.
378 * @param rrset: rrset to add.
379 * @return false on failure (malloc).
382 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq,
383 struct ub_packed_rrset_key* rrset)
385 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
386 qstate->region, sizeof(struct iter_prep_list));
392 if(iq->an_prepend_last)
393 iq->an_prepend_last->next = p;
394 else iq->an_prepend_list = p;
395 iq->an_prepend_last = p;
400 * Add rrset to AUTHORITY prepend list
401 * @param qstate: query state.
402 * @param iq: iterator query state.
403 * @param rrset: rrset to add.
404 * @return false on failure (malloc).
407 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq,
408 struct ub_packed_rrset_key* rrset)
410 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
411 qstate->region, sizeof(struct iter_prep_list));
417 if(iq->ns_prepend_last)
418 iq->ns_prepend_last->next = p;
419 else iq->ns_prepend_list = p;
420 iq->ns_prepend_last = p;
425 * Given a CNAME response (defined as a response containing a CNAME or DNAME
426 * that does not answer the request), process the response, modifying the
427 * state as necessary. This follows the CNAME/DNAME chain and returns the
430 * sets the new query name, after following the CNAME/DNAME chain.
431 * @param qstate: query state.
432 * @param iq: iterator query state.
433 * @param msg: the response.
434 * @param mname: returned target new query name.
435 * @param mname_len: length of mname.
436 * @return false on (malloc) error.
439 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
440 struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
443 /* Start with the (current) qname. */
444 *mname = iq->qchase.qname;
445 *mname_len = iq->qchase.qname_len;
447 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
449 for(i=0; i<msg->rep->an_numrrsets; i++) {
450 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
451 /* If there is a (relevant) DNAME, add it to the list.
452 * We always expect there to be CNAME that was generated
453 * by this DNAME following, so we don't process the DNAME
455 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
456 dname_strict_subdomain_c(*mname, r->rk.dname)) {
457 if(!iter_add_prepend_answer(qstate, iq, r))
462 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
463 query_dname_compare(*mname, r->rk.dname) == 0) {
464 /* Add this relevant CNAME rrset to the prepend list.*/
465 if(!iter_add_prepend_answer(qstate, iq, r))
467 get_cname_target(r, mname, mname_len);
470 /* Other rrsets in the section are ignored. */
472 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */
473 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
474 msg->rep->ns_numrrsets; i++) {
475 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
476 /* only add NSEC/NSEC3, as they may be needed for validation */
477 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
478 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
479 if(!iter_add_prepend_auth(qstate, iq, r))
486 /** see if target name is caps-for-id whitelisted */
488 is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq)
490 if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */
491 return name_tree_lookup(ie->caps_white, iq->qchase.qname,
492 iq->qchase.qname_len, dname_count_labels(iq->qchase.qname),
493 iq->qchase.qclass) != NULL;
496 /** create target count structure for this query */
498 target_count_create(struct iter_qstate* iq)
500 if(!iq->target_count) {
501 iq->target_count = (int*)calloc(2, sizeof(int));
502 /* if calloc fails we simply do not track this number */
504 iq->target_count[0] = 1;
509 target_count_increase(struct iter_qstate* iq, int num)
511 target_count_create(iq);
513 iq->target_count[1] += num;
517 * Generate a subrequest.
518 * Generate a local request event. Local events are tied to this module, and
519 * have a corresponding (first tier) event that is waiting for this event to
520 * resolve to continue.
522 * @param qname The query name for this request.
523 * @param qnamelen length of qname
524 * @param qtype The query type for this request.
525 * @param qclass The query class for this request.
526 * @param qstate The event that is generating this event.
527 * @param id: module id.
528 * @param iq: The iterator state that is generating this event.
529 * @param initial_state The initial response state (normally this
530 * is QUERY_RESP_STATE, unless it is known that the request won't
531 * need iterative processing
532 * @param finalstate The final state for the response to this request.
533 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
534 * not need initialisation.
535 * @param v: if true, validation is done on the subquery.
536 * @return false on error (malloc).
539 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
540 uint16_t qclass, struct module_qstate* qstate, int id,
541 struct iter_qstate* iq, enum iter_state initial_state,
542 enum iter_state finalstate, struct module_qstate** subq_ret, int v)
544 struct module_qstate* subq = NULL;
545 struct iter_qstate* subiq = NULL;
546 uint16_t qflags = 0; /* OPCODE QUERY, no flags */
547 struct query_info qinf;
548 int prime = (finalstate == PRIME_RESP_STATE)?1:0;
551 qinf.qname_len = qnamelen;
553 qinf.qclass = qclass;
555 /* RD should be set only when sending the query back through the INIT
557 if(initial_state == INIT_REQUEST_STATE)
559 /* We set the CD flag so we can send this through the "head" of
560 * the resolution chain, which might have a validator. We are
561 * uninterested in validating things not on the direct resolution
568 /* attach subquery, lookup existing or make a new one */
569 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
570 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, valrec,
576 /* initialise the new subquery */
578 subq->ext_state[id] = module_state_initial;
579 subq->minfo[id] = regional_alloc(subq->region,
580 sizeof(struct iter_qstate));
581 if(!subq->minfo[id]) {
582 log_err("init subq: out of memory");
583 fptr_ok(fptr_whitelist_modenv_kill_sub(
584 qstate->env->kill_sub));
585 (*qstate->env->kill_sub)(subq);
588 subiq = (struct iter_qstate*)subq->minfo[id];
589 memset(subiq, 0, sizeof(*subiq));
590 subiq->num_target_queries = 0;
591 target_count_create(iq);
592 subiq->target_count = iq->target_count;
594 iq->target_count[0] ++; /* extra reference */
595 subiq->num_current_queries = 0;
596 subiq->depth = iq->depth+1;
597 outbound_list_init(&subiq->outlist);
598 subiq->state = initial_state;
599 subiq->final_state = finalstate;
600 subiq->qchase = subq->qinfo;
601 subiq->chase_flags = subq->query_flags;
602 subiq->refetch_glue = 0;
603 if(qstate->env->cfg->qname_minimisation)
604 subiq->minimisation_state = INIT_MINIMISE_STATE;
606 subiq->minimisation_state = DONOT_MINIMISE_STATE;
607 memset(&subiq->qinfo_out, 0, sizeof(struct query_info));
613 * Generate and send a root priming request.
614 * @param qstate: the qtstate that triggered the need to prime.
615 * @param iq: iterator query state.
616 * @param id: module id.
617 * @param qclass: the class to prime.
618 * @return 0 on failure
621 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
625 struct module_qstate* subq;
626 verbose(VERB_DETAIL, "priming . %s NS",
627 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)?
628 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??");
629 dp = hints_lookup_root(qstate->env->hints, qclass);
631 verbose(VERB_ALGO, "Cannot prime due to lack of hints");
634 /* Priming requests start at the QUERYTARGETS state, skipping
635 * the normal INIT state logic (which would cause an infloop). */
636 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
637 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
639 verbose(VERB_ALGO, "could not prime root");
643 struct iter_qstate* subiq =
644 (struct iter_qstate*)subq->minfo[id];
645 /* Set the initial delegation point to the hint.
646 * copy dp, it is now part of the root prime query.
647 * dp was part of in the fixed hints structure. */
648 subiq->dp = delegpt_copy(dp, subq->region);
650 log_err("out of memory priming root, copydp");
651 fptr_ok(fptr_whitelist_modenv_kill_sub(
652 qstate->env->kill_sub));
653 (*qstate->env->kill_sub)(subq);
656 /* there should not be any target queries. */
657 subiq->num_target_queries = 0;
658 subiq->dnssec_expected = iter_indicates_dnssec(
659 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
662 /* this module stops, our submodule starts, and does the query. */
663 qstate->ext_state[id] = module_wait_subquery;
668 * Generate and process a stub priming request. This method tests for the
669 * need to prime a stub zone, so it is safe to call for every request.
671 * @param qstate: the qtstate that triggered the need to prime.
672 * @param iq: iterator query state.
673 * @param id: module id.
674 * @param qname: request name.
675 * @param qclass: request class.
676 * @return true if a priming subrequest was made, false if not. The will only
677 * issue a priming request if it detects an unprimed stub.
678 * Uses value of 2 to signal during stub-prime in root-prime situation
679 * that a noprime-stub is available and resolution can continue.
682 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id,
683 uint8_t* qname, uint16_t qclass)
685 /* Lookup the stub hint. This will return null if the stub doesn't
686 * need to be re-primed. */
687 struct iter_hints_stub* stub;
688 struct delegpt* stub_dp;
689 struct module_qstate* subq;
692 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
693 /* The stub (if there is one) does not need priming. */
698 /* is it a noprime stub (always use) */
701 if(iq->dp == NULL) r = 2;
702 /* copy the dp out of the fixed hints structure, so that
703 * it can be changed when servicing this query */
704 iq->dp = delegpt_copy(stub_dp, qstate->region);
706 log_err("out of memory priming stub");
707 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
708 return 1; /* return 1 to make module stop, with error */
710 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
711 LDNS_RR_TYPE_NS, qclass);
715 /* Otherwise, we need to (re)prime the stub. */
716 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name,
717 LDNS_RR_TYPE_NS, qclass);
719 /* Stub priming events start at the QUERYTARGETS state to avoid the
720 * redundant INIT state processing. */
721 if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
722 LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
723 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) {
724 verbose(VERB_ALGO, "could not prime stub");
725 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
726 return 1; /* return 1 to make module stop, with error */
729 struct iter_qstate* subiq =
730 (struct iter_qstate*)subq->minfo[id];
732 /* Set the initial delegation point to the hint. */
733 /* make copy to avoid use of stub dp by different qs/threads */
734 subiq->dp = delegpt_copy(stub_dp, subq->region);
736 log_err("out of memory priming stub, copydp");
737 fptr_ok(fptr_whitelist_modenv_kill_sub(
738 qstate->env->kill_sub));
739 (*qstate->env->kill_sub)(subq);
740 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
741 return 1; /* return 1 to make module stop, with error */
743 /* there should not be any target queries -- although there
744 * wouldn't be anyway, since stub hints never have
745 * missing targets. */
746 subiq->num_target_queries = 0;
747 subiq->wait_priming_stub = 1;
748 subiq->dnssec_expected = iter_indicates_dnssec(
749 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
752 /* this module stops, our submodule starts, and does the query. */
753 qstate->ext_state[id] = module_wait_subquery;
758 * Generate A and AAAA checks for glue that is in-zone for the referral
759 * we just got to obtain authoritative information on the adresses.
761 * @param qstate: the qtstate that triggered the need to prime.
762 * @param iq: iterator query state.
763 * @param id: module id.
766 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
769 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
770 struct module_qstate* subq;
772 struct reply_info* rep = iq->response->rep;
773 struct ub_packed_rrset_key* s;
776 if(iq->depth == ie->max_dependency_depth)
778 /* walk through additional, and check if in-zone,
779 * only relevant A, AAAA are left after scrub anyway */
780 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
782 /* check *ALL* addresses that are transmitted in additional*/
783 /* is it an address ? */
784 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
785 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
788 /* is this query the same as the A/AAAA check for it */
789 if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
790 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
791 query_dname_compare(qstate->qinfo.qname,
793 (qstate->query_flags&BIT_RD) &&
794 !(qstate->query_flags&BIT_CD))
797 /* generate subrequest for it */
798 log_nametypeclass(VERB_ALGO, "schedule addr fetch",
799 s->rk.dname, ntohs(s->rk.type),
800 ntohs(s->rk.rrset_class));
801 if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
802 ntohs(s->rk.type), ntohs(s->rk.rrset_class),
804 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
805 verbose(VERB_ALGO, "could not generate addr check");
808 /* ignore subq - not need for more init */
813 * Generate a NS check request to obtain authoritative information
816 * @param qstate: the qtstate that triggered the need to prime.
817 * @param iq: iterator query state.
818 * @param id: module id.
821 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
823 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
824 struct module_qstate* subq;
827 if(iq->depth == ie->max_dependency_depth)
829 /* is this query the same as the nscheck? */
830 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
831 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
832 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
833 /* spawn off A, AAAA queries for in-zone glue to check */
834 generate_a_aaaa_check(qstate, iq, id);
838 log_nametypeclass(VERB_ALGO, "schedule ns fetch",
839 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
840 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
841 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
842 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
843 verbose(VERB_ALGO, "could not generate ns check");
847 struct iter_qstate* subiq =
848 (struct iter_qstate*)subq->minfo[id];
850 /* make copy to avoid use of stub dp by different qs/threads */
851 /* refetch glue to start higher up the tree */
852 subiq->refetch_glue = 1;
853 subiq->dp = delegpt_copy(iq->dp, subq->region);
855 log_err("out of memory generating ns check, copydp");
856 fptr_ok(fptr_whitelist_modenv_kill_sub(
857 qstate->env->kill_sub));
858 (*qstate->env->kill_sub)(subq);
865 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
866 * just got in a referral (where we have dnssec_expected, thus have trust
867 * anchors above it). Note that right after calling this routine the
868 * iterator detached subqueries (because of following the referral), and thus
869 * the DNSKEY query becomes detached, its return stored in the cache for
870 * later lookup by the validator. This cache lookup by the validator avoids
871 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
872 * performed at about the same time the original query is sent to the domain,
873 * thus the two answers are likely to be returned at about the same time,
874 * saving a roundtrip from the validated lookup.
876 * @param qstate: the qtstate that triggered the need to prime.
877 * @param iq: iterator query state.
878 * @param id: module id.
881 generate_dnskey_prefetch(struct module_qstate* qstate,
882 struct iter_qstate* iq, int id)
884 struct module_qstate* subq;
887 /* is this query the same as the prefetch? */
888 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
889 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
890 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
894 /* if the DNSKEY is in the cache this lookup will stop quickly */
895 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
896 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
897 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
898 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
899 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
900 /* we'll be slower, but it'll work */
901 verbose(VERB_ALGO, "could not generate dnskey prefetch");
905 struct iter_qstate* subiq =
906 (struct iter_qstate*)subq->minfo[id];
907 /* this qstate has the right delegation for the dnskey lookup*/
908 /* make copy to avoid use of stub dp by different qs/threads */
909 subiq->dp = delegpt_copy(iq->dp, subq->region);
910 /* if !subiq->dp, it'll start from the cache, no problem */
915 * See if the query needs forwarding.
917 * @param qstate: query state.
918 * @param iq: iterator query state.
919 * @return true if the request is forwarded, false if not.
920 * If returns true but, iq->dp is NULL then a malloc failure occurred.
923 forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
926 uint8_t* delname = iq->qchase.qname;
927 size_t delnamelen = iq->qchase.qname_len;
928 if(iq->refetch_glue) {
929 delname = iq->dp->name;
930 delnamelen = iq->dp->namelen;
932 /* strip one label off of DS query to lookup higher for it */
933 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
934 && !dname_is_root(iq->qchase.qname))
935 dname_remove_label(&delname, &delnamelen);
936 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
939 /* send recursion desired to forward addr */
940 iq->chase_flags |= BIT_RD;
941 iq->dp = delegpt_copy(dp, qstate->region);
942 /* iq->dp checked by caller */
943 verbose(VERB_ALGO, "forwarding request");
948 * Process the initial part of the request handling. This state roughly
949 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2
950 * (find the best servers to ask).
952 * Note that all requests start here, and query restarts revisit this state.
954 * This state either generates: 1) a response, from cache or error, 2) a
955 * priming event, or 3) forwards the request to the next state (init2,
958 * @param qstate: query state.
959 * @param iq: iterator query state.
960 * @param ie: iterator shared global environment.
961 * @param id: module id.
962 * @return true if the event needs more request processing immediately,
966 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
967 struct iter_env* ie, int id)
973 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
976 /* We enforce a maximum number of query restarts. This is primarily a
977 * cheap way to prevent CNAME loops. */
978 if(iq->query_restart_count > MAX_RESTART_COUNT) {
979 verbose(VERB_QUERY, "request has exceeded the maximum number"
980 " of query restarts with %d", iq->query_restart_count);
981 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
984 /* We enforce a maximum recursion/dependency depth -- in general,
985 * this is unnecessary for dependency loops (although it will
986 * catch those), but it provides a sensible limit to the amount
987 * of work required to answer a given query. */
988 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
989 if(iq->depth > ie->max_dependency_depth) {
990 verbose(VERB_QUERY, "request has exceeded the maximum "
991 "dependency depth with depth of %d", iq->depth);
992 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
995 /* If the request is qclass=ANY, setup to generate each class */
996 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
997 iq->qchase.qclass = 0;
998 return next_state(iq, COLLECT_CLASS_STATE);
1001 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */
1003 /* This either results in a query restart (CNAME cache response), a
1004 * terminating response (ANSWER), or a cache miss (null). */
1006 if(qstate->blacklist) {
1007 /* if cache, or anything else, was blacklisted then
1008 * getting older results from cache is a bad idea, no cache */
1009 verbose(VERB_ALGO, "cache blacklisted, going to the network");
1012 msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
1013 iq->qchase.qname_len, iq->qchase.qtype,
1014 iq->qchase.qclass, qstate->query_flags,
1015 qstate->region, qstate->env->scratch);
1016 if(!msg && qstate->env->neg_cache) {
1017 /* lookup in negative cache; may result in
1018 * NOERROR/NODATA or NXDOMAIN answers that need validation */
1019 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
1020 qstate->region, qstate->env->rrset_cache,
1021 qstate->env->scratch_buffer,
1022 *qstate->env->now, 1/*add SOA*/, NULL);
1024 /* item taken from cache does not match our query name, thus
1025 * security needs to be re-examined later */
1026 if(msg && query_dname_compare(qstate->qinfo.qname,
1027 iq->qchase.qname) != 0)
1028 msg->rep->security = sec_status_unchecked;
1031 /* handle positive cache response */
1032 enum response_type type = response_type_from_cache(msg,
1034 if(verbosity >= VERB_ALGO) {
1035 log_dns_msg("msg from cache lookup", &msg->qinfo,
1037 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
1039 (int)msg->rep->prefetch_ttl);
1042 if(type == RESPONSE_TYPE_CNAME) {
1045 verbose(VERB_ALGO, "returning CNAME response from "
1047 if(!handle_cname_response(qstate, iq, msg,
1049 return error_response(qstate, id,
1050 LDNS_RCODE_SERVFAIL);
1051 iq->qchase.qname = sname;
1052 iq->qchase.qname_len = slen;
1053 /* This *is* a query restart, even if it is a cheap
1056 iq->refetch_glue = 0;
1057 iq->query_restart_count++;
1059 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1060 if(qstate->env->cfg->qname_minimisation)
1061 iq->minimisation_state = INIT_MINIMISE_STATE;
1062 return next_state(iq, INIT_REQUEST_STATE);
1065 /* if from cache, NULL, else insert 'cache IP' len=0 */
1066 if(qstate->reply_origin)
1067 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1068 /* it is an answer, response, to final state */
1069 verbose(VERB_ALGO, "returning answer from cache.");
1071 return final_state(iq);
1074 /* attempt to forward the request */
1075 if(forward_request(qstate, iq))
1078 log_err("alloc failure for forward dp");
1079 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1081 iq->refetch_glue = 0;
1082 iq->minimisation_state = DONOT_MINIMISE_STATE;
1083 /* the request has been forwarded.
1084 * forwarded requests need to be immediately sent to the
1085 * next state, QUERYTARGETS. */
1086 return next_state(iq, QUERYTARGETS_STATE);
1089 /* Resolver Algorithm Step 2 -- find the "best" servers. */
1091 /* first, adjust for DS queries. To avoid the grandparent problem,
1092 * we just look for the closest set of server to the parent of qname.
1093 * When re-fetching glue we also need to ask the parent.
1095 if(iq->refetch_glue) {
1097 log_err("internal or malloc fail: no dp for refetch");
1098 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1100 delname = iq->dp->name;
1101 delnamelen = iq->dp->namelen;
1103 delname = iq->qchase.qname;
1104 delnamelen = iq->qchase.qname_len;
1106 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
1107 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) {
1108 /* remove first label from delname, root goes to hints,
1109 * but only to fetch glue, not for qtype=DS. */
1110 /* also when prefetching an NS record, fetch it again from
1111 * its parent, just as if it expired, so that you do not
1112 * get stuck on an older nameserver that gives old NSrecords */
1113 if(dname_is_root(delname) && (iq->refetch_glue ||
1114 (iq->qchase.qtype == LDNS_RR_TYPE_NS &&
1115 qstate->prefetch_leeway)))
1116 delname = NULL; /* go to root priming */
1117 else dname_remove_label(&delname, &delnamelen);
1119 /* delname is the name to lookup a delegation for. If NULL rootprime */
1122 /* Lookup the delegation in the cache. If null, then the
1123 * cache needs to be primed for the qclass. */
1125 iq->dp = dns_cache_find_delegation(qstate->env, delname,
1126 delnamelen, iq->qchase.qtype, iq->qchase.qclass,
1127 qstate->region, &iq->deleg_msg,
1128 *qstate->env->now+qstate->prefetch_leeway);
1131 /* If the cache has returned nothing, then we have a
1132 * root priming situation. */
1133 if(iq->dp == NULL) {
1134 /* if there is a stub, then no root prime needed */
1135 int r = prime_stub(qstate, iq, id, delname,
1138 break; /* got noprime-stub-zone, continue */
1140 return 0; /* stub prime request made */
1141 if(forwards_lookup_root(qstate->env->fwds,
1142 iq->qchase.qclass)) {
1143 /* forward zone root, no root prime needed */
1144 /* fill in some dp - safety belt */
1145 iq->dp = hints_lookup_root(qstate->env->hints,
1148 log_err("internal error: no hints dp");
1149 return error_response(qstate, id,
1150 LDNS_RCODE_SERVFAIL);
1152 iq->dp = delegpt_copy(iq->dp, qstate->region);
1154 log_err("out of memory in safety belt");
1155 return error_response(qstate, id,
1156 LDNS_RCODE_SERVFAIL);
1158 return next_state(iq, INIT_REQUEST_2_STATE);
1160 /* Note that the result of this will set a new
1161 * DelegationPoint based on the result of priming. */
1162 if(!prime_root(qstate, iq, id, iq->qchase.qclass))
1163 return error_response(qstate, id,
1164 LDNS_RCODE_REFUSED);
1166 /* priming creates and sends a subordinate query, with
1167 * this query as the parent. So further processing for
1168 * this event will stop until reactivated by the
1169 * results of priming. */
1172 if(!iq->ratelimit_ok && qstate->prefetch_leeway)
1173 iq->ratelimit_ok = 1; /* allow prefetches, this keeps
1174 otherwise valid data in the cache */
1175 if(!iq->ratelimit_ok && infra_ratelimit_exceeded(
1176 qstate->env->infra_cache, iq->dp->name,
1177 iq->dp->namelen, *qstate->env->now)) {
1178 /* and increment the rate, so that the rate for time
1179 * now will also exceed the rate, keeping cache fresh */
1180 (void)infra_ratelimit_inc(qstate->env->infra_cache,
1181 iq->dp->name, iq->dp->namelen,
1183 /* see if we are passed through with slip factor */
1184 if(qstate->env->cfg->ratelimit_factor != 0 &&
1185 ub_random_max(qstate->env->rnd,
1186 qstate->env->cfg->ratelimit_factor) == 1) {
1187 iq->ratelimit_ok = 1;
1188 log_nametypeclass(VERB_ALGO, "ratelimit allowed through for "
1189 "delegation point", iq->dp->name,
1190 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
1192 log_nametypeclass(VERB_ALGO, "ratelimit exceeded with "
1193 "delegation point", iq->dp->name,
1194 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
1195 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1199 /* see if this dp not useless.
1201 * o all NS items are required glue.
1202 * or the query is for NS item that is required glue.
1203 * o no addresses are provided.
1205 * Instead, go up one level, and try to get even further
1206 * If the root was useless, use safety belt information.
1207 * Only check cache returns, because replies for servers
1208 * could be useless but lead to loops (bumping into the
1209 * same server reply) if useless-checked.
1211 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
1213 if(dname_is_root(iq->dp->name)) {
1214 /* use safety belt */
1215 verbose(VERB_QUERY, "Cache has root NS but "
1216 "no addresses. Fallback to the safety belt.");
1217 iq->dp = hints_lookup_root(qstate->env->hints,
1219 /* note deleg_msg is from previous lookup,
1220 * but RD is on, so it is not used */
1222 log_err("internal error: no hints dp");
1223 return error_response(qstate, id,
1224 LDNS_RCODE_REFUSED);
1226 iq->dp = delegpt_copy(iq->dp, qstate->region);
1228 log_err("out of memory in safety belt");
1229 return error_response(qstate, id,
1230 LDNS_RCODE_SERVFAIL);
1235 "cache delegation was useless:");
1236 delegpt_log(VERB_ALGO, iq->dp);
1238 delname = iq->dp->name;
1239 delnamelen = iq->dp->namelen;
1240 dname_remove_label(&delname, &delnamelen);
1245 verbose(VERB_ALGO, "cache delegation returns delegpt");
1246 delegpt_log(VERB_ALGO, iq->dp);
1248 /* Otherwise, set the current delegation point and move on to the
1250 return next_state(iq, INIT_REQUEST_2_STATE);
1254 * Process the second part of the initial request handling. This state
1255 * basically exists so that queries that generate root priming events have
1256 * the same init processing as ones that do not. Request events that reach
1257 * this state must have a valid currentDelegationPoint set.
1259 * This part is primarly handling stub zone priming. Events that reach this
1260 * state must have a current delegation point.
1262 * @param qstate: query state.
1263 * @param iq: iterator query state.
1264 * @param id: module id.
1265 * @return true if the event needs more request processing immediately,
1269 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
1274 log_query_info(VERB_QUERY, "resolving (init part 2): ",
1277 if(iq->refetch_glue) {
1279 log_err("internal or malloc fail: no dp for refetch");
1280 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1282 delname = iq->dp->name;
1283 delnamelen = iq->dp->namelen;
1285 delname = iq->qchase.qname;
1286 delnamelen = iq->qchase.qname_len;
1288 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
1289 if(!dname_is_root(delname))
1290 dname_remove_label(&delname, &delnamelen);
1291 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
1293 /* Check to see if we need to prime a stub zone. */
1294 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
1295 /* A priming sub request was made */
1299 /* most events just get forwarded to the next state. */
1300 return next_state(iq, INIT_REQUEST_3_STATE);
1304 * Process the third part of the initial request handling. This state exists
1305 * as a separate state so that queries that generate stub priming events
1306 * will get the tail end of the init process but not repeat the stub priming
1309 * @param qstate: query state.
1310 * @param iq: iterator query state.
1311 * @param id: module id.
1312 * @return true, advancing the event to the QUERYTARGETS_STATE.
1315 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
1318 log_query_info(VERB_QUERY, "resolving (init part 3): ",
1320 /* if the cache reply dp equals a validation anchor or msg has DS,
1321 * then DNSSEC RRSIGs are expected in the reply */
1322 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
1323 iq->deleg_msg, iq->qchase.qclass);
1325 /* If the RD flag wasn't set, then we just finish with the
1326 * cached referral as the response. */
1327 if(!(qstate->query_flags & BIT_RD)) {
1328 iq->response = iq->deleg_msg;
1329 if(verbosity >= VERB_ALGO && iq->response)
1330 log_dns_msg("no RD requested, using delegation msg",
1331 &iq->response->qinfo, iq->response->rep);
1332 if(qstate->reply_origin)
1333 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1334 return final_state(iq);
1336 /* After this point, unset the RD flag -- this query is going to
1337 * be sent to an auth. server. */
1338 iq->chase_flags &= ~BIT_RD;
1340 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */
1341 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
1342 !(qstate->query_flags&BIT_CD)) {
1343 generate_dnskey_prefetch(qstate, iq, id);
1344 fptr_ok(fptr_whitelist_modenv_detach_subs(
1345 qstate->env->detach_subs));
1346 (*qstate->env->detach_subs)(qstate);
1349 /* Jump to the next state. */
1350 return next_state(iq, QUERYTARGETS_STATE);
1354 * Given a basic query, generate a parent-side "target" query.
1355 * These are subordinate queries for missing delegation point target addresses,
1356 * for which only the parent of the delegation provides correct IP addresses.
1358 * @param qstate: query state.
1359 * @param iq: iterator query state.
1360 * @param id: module id.
1361 * @param name: target qname.
1362 * @param namelen: target qname length.
1363 * @param qtype: target qtype (either A or AAAA).
1364 * @param qclass: target qclass.
1365 * @return true on success, false on failure.
1368 generate_parentside_target_query(struct module_qstate* qstate,
1369 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen,
1370 uint16_t qtype, uint16_t qclass)
1372 struct module_qstate* subq;
1373 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1374 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
1377 struct iter_qstate* subiq =
1378 (struct iter_qstate*)subq->minfo[id];
1379 /* blacklist the cache - we want to fetch parent stuff */
1380 sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
1381 subiq->query_for_pside_glue = 1;
1382 if(dname_subdomain_c(name, iq->dp->name)) {
1383 subiq->dp = delegpt_copy(iq->dp, subq->region);
1384 subiq->dnssec_expected = iter_indicates_dnssec(
1385 qstate->env, subiq->dp, NULL,
1386 subq->qinfo.qclass);
1387 subiq->refetch_glue = 1;
1389 subiq->dp = dns_cache_find_delegation(qstate->env,
1390 name, namelen, qtype, qclass, subq->region,
1392 *qstate->env->now+subq->prefetch_leeway);
1393 /* if no dp, then it's from root, refetch unneeded */
1395 subiq->dnssec_expected = iter_indicates_dnssec(
1396 qstate->env, subiq->dp, NULL,
1397 subq->qinfo.qclass);
1398 subiq->refetch_glue = 1;
1402 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
1407 * Given a basic query, generate a "target" query. These are subordinate
1408 * queries for missing delegation point target addresses.
1410 * @param qstate: query state.
1411 * @param iq: iterator query state.
1412 * @param id: module id.
1413 * @param name: target qname.
1414 * @param namelen: target qname length.
1415 * @param qtype: target qtype (either A or AAAA).
1416 * @param qclass: target qclass.
1417 * @return true on success, false on failure.
1420 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
1421 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
1423 struct module_qstate* subq;
1424 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1425 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
1427 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
1432 * Given an event at a certain state, generate zero or more target queries
1433 * for it's current delegation point.
1435 * @param qstate: query state.
1436 * @param iq: iterator query state.
1437 * @param ie: iterator shared global environment.
1438 * @param id: module id.
1439 * @param maxtargets: The maximum number of targets to query for.
1440 * if it is negative, there is no maximum number of targets.
1441 * @param num: returns the number of queries generated and processed,
1442 * which may be zero if there were no missing targets.
1443 * @return false on error.
1446 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
1447 struct iter_env* ie, int id, int maxtargets, int* num)
1449 int query_count = 0;
1450 struct delegpt_ns* ns;
1454 if(iq->depth == ie->max_dependency_depth)
1456 if(iq->depth > 0 && iq->target_count &&
1457 iq->target_count[1] > MAX_TARGET_COUNT) {
1458 char s[LDNS_MAX_DOMAINLEN+1];
1459 dname_str(qstate->qinfo.qname, s);
1460 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1461 "number of glue fetches %d", s, iq->target_count[1]);
1465 iter_mark_cycle_targets(qstate, iq->dp);
1466 missing = (int)delegpt_count_missing_targets(iq->dp);
1467 log_assert(maxtargets != 0); /* that would not be useful */
1469 /* Generate target requests. Basically, any missing targets
1470 * are queried for here, regardless if it is necessary to do
1471 * so to continue processing. */
1472 if(maxtargets < 0 || maxtargets > missing)
1474 else toget = maxtargets;
1479 /* select 'toget' items from the total of 'missing' items */
1480 log_assert(toget <= missing);
1482 /* loop over missing targets */
1483 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1487 /* randomly select this item with probability toget/missing */
1488 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
1489 /* do not select this one, next; select toget number
1490 * of items from a list one less in size */
1495 if(ie->supports_ipv6 && !ns->got6) {
1496 /* Send the AAAA request. */
1497 if(!generate_target_query(qstate, iq, id,
1498 ns->name, ns->namelen,
1499 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
1502 qstate->ext_state[id] = module_wait_subquery;
1507 /* Send the A request. */
1508 if(ie->supports_ipv4 && !ns->got4) {
1509 if(!generate_target_query(qstate, iq, id,
1510 ns->name, ns->namelen,
1511 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
1514 qstate->ext_state[id] = module_wait_subquery;
1520 /* mark this target as in progress. */
1529 qstate->ext_state[id] = module_wait_subquery;
1534 /** see if last resort is possible - does config allow queries to parent */
1536 can_have_last_resort(struct module_env* env, struct delegpt* dp,
1537 struct iter_qstate* iq)
1539 struct delegpt* fwddp;
1540 struct iter_hints_stub* stub;
1541 /* do not process a last resort (the parent side) if a stub
1542 * or forward is configured, because we do not want to go 'above'
1543 * the configured servers */
1544 if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*)
1545 name_tree_find(&env->hints->tree, dp->name, dp->namelen,
1546 dp->namelabs, iq->qchase.qclass)) &&
1547 /* has_parent side is turned off for stub_first, where we
1548 * are allowed to go to the parent */
1549 stub->dp->has_parent_side_NS) {
1550 verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL");
1553 if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) &&
1554 /* has_parent_side is turned off for forward_first, where
1555 * we are allowed to go to the parent */
1556 fwddp->has_parent_side_NS) {
1557 verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL");
1564 * Called by processQueryTargets when it would like extra targets to query
1565 * but it seems to be out of options. At last resort some less appealing
1566 * options are explored. If there are no more options, the result is SERVFAIL
1568 * @param qstate: query state.
1569 * @param iq: iterator query state.
1570 * @param ie: iterator shared global environment.
1571 * @param id: module id.
1572 * @return true if the event requires more request processing immediately,
1576 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
1577 struct iter_env* ie, int id)
1579 struct delegpt_ns* ns;
1580 int query_count = 0;
1581 verbose(VERB_ALGO, "No more query targets, attempting last resort");
1584 if(!can_have_last_resort(qstate->env, iq->dp, iq)) {
1585 /* fail -- no more targets, no more hope of targets, no hope
1587 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1589 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
1590 struct delegpt* p = hints_lookup_root(qstate->env->hints,
1593 struct delegpt_ns* ns;
1594 struct delegpt_addr* a;
1595 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1596 for(ns = p->nslist; ns; ns=ns->next) {
1597 (void)delegpt_add_ns(iq->dp, qstate->region,
1598 ns->name, ns->lame);
1600 for(a = p->target_list; a; a=a->next_target) {
1601 (void)delegpt_add_addr(iq->dp, qstate->region,
1602 &a->addr, a->addrlen, a->bogus,
1606 iq->dp->has_parent_side_NS = 1;
1607 } else if(!iq->dp->has_parent_side_NS) {
1608 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
1609 qstate->region, &qstate->qinfo)
1610 || !iq->dp->has_parent_side_NS) {
1611 /* if: malloc failure in lookup go up to try */
1612 /* if: no parent NS in cache - go up one level */
1613 verbose(VERB_ALGO, "try to grab parent NS");
1614 iq->store_parent_NS = iq->dp;
1615 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1616 iq->deleg_msg = NULL;
1617 iq->refetch_glue = 1;
1618 iq->query_restart_count++;
1620 if(qstate->env->cfg->qname_minimisation)
1621 iq->minimisation_state = INIT_MINIMISE_STATE;
1622 return next_state(iq, INIT_REQUEST_STATE);
1625 /* see if that makes new names available */
1626 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
1627 qstate->region, iq->dp))
1628 log_err("out of memory in cache_fill_missing");
1629 if(iq->dp->usable_list) {
1630 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
1631 return next_state(iq, QUERYTARGETS_STATE);
1633 /* try to fill out parent glue from cache */
1634 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
1635 qstate->region, &qstate->qinfo)) {
1636 /* got parent stuff from cache, see if we can continue */
1637 verbose(VERB_ALGO, "try parent-side glue from cache");
1638 return next_state(iq, QUERYTARGETS_STATE);
1640 /* query for an extra name added by the parent-NS record */
1641 if(delegpt_count_missing_targets(iq->dp) > 0) {
1643 verbose(VERB_ALGO, "try parent-side target name");
1644 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
1645 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1647 iq->num_target_queries += qs;
1648 target_count_increase(iq, qs);
1650 qstate->ext_state[id] = module_wait_subquery;
1651 return 0; /* and wait for them */
1654 if(iq->depth == ie->max_dependency_depth) {
1655 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
1656 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1658 if(iq->depth > 0 && iq->target_count &&
1659 iq->target_count[1] > MAX_TARGET_COUNT) {
1660 char s[LDNS_MAX_DOMAINLEN+1];
1661 dname_str(qstate->qinfo.qname, s);
1662 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1663 "number of glue fetches %d", s, iq->target_count[1]);
1664 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1666 /* mark cycle targets for parent-side lookups */
1667 iter_mark_pside_cycle_targets(qstate, iq->dp);
1668 /* see if we can issue queries to get nameserver addresses */
1669 /* this lookup is not randomized, but sequential. */
1670 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1671 /* query for parent-side A and AAAA for nameservers */
1672 if(ie->supports_ipv6 && !ns->done_pside6) {
1673 /* Send the AAAA request. */
1674 if(!generate_parentside_target_query(qstate, iq, id,
1675 ns->name, ns->namelen,
1676 LDNS_RR_TYPE_AAAA, iq->qchase.qclass))
1677 return error_response(qstate, id,
1678 LDNS_RCODE_SERVFAIL);
1679 ns->done_pside6 = 1;
1682 if(ie->supports_ipv4 && !ns->done_pside4) {
1683 /* Send the A request. */
1684 if(!generate_parentside_target_query(qstate, iq, id,
1685 ns->name, ns->namelen,
1686 LDNS_RR_TYPE_A, iq->qchase.qclass))
1687 return error_response(qstate, id,
1688 LDNS_RCODE_SERVFAIL);
1689 ns->done_pside4 = 1;
1692 if(query_count != 0) { /* suspend to await results */
1693 verbose(VERB_ALGO, "try parent-side glue lookup");
1694 iq->num_target_queries += query_count;
1695 target_count_increase(iq, query_count);
1696 qstate->ext_state[id] = module_wait_subquery;
1701 /* if this was a parent-side glue query itself, then store that
1702 * failure in cache. */
1703 if(iq->query_for_pside_glue && !iq->pside_glue)
1704 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
1705 iq->deleg_msg?iq->deleg_msg->rep:
1706 (iq->response?iq->response->rep:NULL));
1708 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
1709 /* fail -- no more targets, no more hope of targets, no hope
1711 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1715 * Try to find the NS record set that will resolve a qtype DS query. Due
1716 * to grandparent/grandchild reasons we did not get a proper lookup right
1717 * away. We need to create type NS queries until we get the right parent
1718 * for this lookup. We remove labels from the query to find the right point.
1719 * If we end up at the old dp name, then there is no solution.
1721 * @param qstate: query state.
1722 * @param iq: iterator query state.
1723 * @param id: module id.
1724 * @return true if the event requires more immediate processing, false if
1725 * not. This is generally only true when forwarding the request to
1726 * the final state (i.e., on answer).
1729 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
1731 struct module_qstate* subq = NULL;
1732 verbose(VERB_ALGO, "processDSNSFind");
1734 if(!iq->dsns_point) {
1736 iq->dsns_point = iq->qchase.qname;
1737 iq->dsns_point_len = iq->qchase.qname_len;
1739 /* robustcheck for internal error: we are not underneath the dp */
1740 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
1741 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1744 /* go up one (more) step, until we hit the dp, if so, end */
1745 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
1746 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
1747 /* there was no inbetween nameserver, use the old delegation
1748 * point again. And this time, because dsns_point is nonNULL
1749 * we are going to accept the (bad) result */
1750 iq->state = QUERYTARGETS_STATE;
1753 iq->state = DSNS_FIND_STATE;
1755 /* spawn NS lookup (validation not needed, this is for DS lookup) */
1756 log_nametypeclass(VERB_ALGO, "fetch nameservers",
1757 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
1758 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
1759 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
1760 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
1761 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1768 * This is the request event state where the request will be sent to one of
1769 * its current query targets. This state also handles issuing target lookup
1770 * queries for missing target IP addresses. Queries typically iterate on
1771 * this state, both when they are just trying different targets for a given
1772 * delegation point, and when they change delegation points. This state
1773 * roughly corresponds to RFC 1034 algorithm steps 3 and 4.
1775 * @param qstate: query state.
1776 * @param iq: iterator query state.
1777 * @param ie: iterator shared global environment.
1778 * @param id: module id.
1779 * @return true if the event requires more request processing immediately,
1780 * false if not. This state only returns true when it is generating
1781 * a SERVFAIL response because the query has hit a dead end.
1784 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
1785 struct iter_env* ie, int id)
1788 struct delegpt_addr* target;
1789 struct outbound_entry* outq;
1790 /* EDNS options to set on outgoing packet */
1791 struct edns_option* opt_list = NULL;
1793 /* NOTE: a request will encounter this state for each target it
1794 * needs to send a query to. That is, at least one per referral,
1795 * more if some targets timeout or return throwaway answers. */
1797 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
1798 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
1799 "currentqueries %d sentcount %d", iq->num_target_queries,
1800 iq->num_current_queries, iq->sent_count);
1802 /* Make sure that we haven't run away */
1803 /* FIXME: is this check even necessary? */
1804 if(iq->referral_count > MAX_REFERRAL_COUNT) {
1805 verbose(VERB_QUERY, "request has exceeded the maximum "
1806 "number of referrrals with %d", iq->referral_count);
1807 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1809 if(iq->sent_count > MAX_SENT_COUNT) {
1810 verbose(VERB_QUERY, "request has exceeded the maximum "
1811 "number of sends with %d", iq->sent_count);
1812 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1815 /* Make sure we have a delegation point, otherwise priming failed
1816 * or another failure occurred */
1818 verbose(VERB_QUERY, "Failed to get a delegation, giving up");
1819 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1821 if(!ie->supports_ipv6)
1822 delegpt_no_ipv6(iq->dp);
1823 if(!ie->supports_ipv4)
1824 delegpt_no_ipv4(iq->dp);
1825 delegpt_log(VERB_ALGO, iq->dp);
1827 if(iq->num_current_queries>0) {
1828 /* already busy answering a query, this restart is because
1829 * more delegpt addrs became available, wait for existing
1831 verbose(VERB_ALGO, "woke up, but wait for outstanding query");
1832 qstate->ext_state[id] = module_wait_reply;
1837 /* < not <=, because although the array is large enough for <=, the
1838 * generated query will immediately be discarded due to depth and
1839 * that servfail is cached, which is not good as opportunism goes. */
1840 if(iq->depth < ie->max_dependency_depth
1841 && iq->sent_count < TARGET_FETCH_STOP) {
1842 tf_policy = ie->target_fetch_policy[iq->depth];
1845 /* if in 0x20 fallback get as many targets as possible */
1846 if(iq->caps_fallback) {
1848 size_t naddr, nres, navail;
1849 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
1850 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1852 iq->num_target_queries += extra;
1853 target_count_increase(iq, extra);
1854 if(iq->num_target_queries > 0) {
1855 /* wait to get all targets, we want to try em */
1856 verbose(VERB_ALGO, "wait for all targets for fallback");
1857 qstate->ext_state[id] = module_wait_reply;
1860 /* did we do enough fallback queries already? */
1861 delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
1862 /* the current caps_server is the number of fallbacks sent.
1863 * the original query is one that matched too, so we have
1864 * caps_server+1 number of matching queries now */
1865 if(iq->caps_server+1 >= naddr*3 ||
1866 iq->caps_server*2+2 >= MAX_SENT_COUNT) {
1867 /* *2 on sentcount check because ipv6 may fail */
1868 /* we're done, process the response */
1869 verbose(VERB_ALGO, "0x20 fallback had %d responses "
1870 "match for %d wanted, done.",
1871 (int)iq->caps_server+1, (int)naddr*3);
1872 iq->response = iq->caps_response;
1873 iq->caps_fallback = 0;
1874 iter_dec_attempts(iq->dp, 3); /* space for fallback */
1875 iq->num_current_queries++; /* RespState decrements it*/
1876 iq->referral_count++; /* make sure we don't loop */
1878 iq->state = QUERY_RESP_STATE;
1881 verbose(VERB_ALGO, "0x20 fallback number %d",
1882 (int)iq->caps_server);
1884 /* if there is a policy to fetch missing targets
1885 * opportunistically, do it. we rely on the fact that once a
1886 * query (or queries) for a missing name have been issued,
1887 * they will not show up again. */
1888 } else if(tf_policy != 0) {
1890 verbose(VERB_ALGO, "attempt to get extra %d targets",
1892 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
1893 /* errors ignored, these targets are not strictly necessary for
1894 * this result, we do not have to reply with SERVFAIL */
1895 iq->num_target_queries += extra;
1896 target_count_increase(iq, extra);
1899 /* Add the current set of unused targets to our queue. */
1900 delegpt_add_unused_targets(iq->dp);
1902 /* Select the next usable target, filtering out unsuitable targets. */
1903 target = iter_server_selection(ie, qstate->env, iq->dp,
1904 iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
1905 &iq->dnssec_lame_query, &iq->chase_to_rd,
1906 iq->num_target_queries, qstate->blacklist);
1908 /* If no usable target was selected... */
1910 /* Here we distinguish between three states: generate a new
1911 * target query, just wait, or quit (with a SERVFAIL).
1912 * We have the following information: number of active
1913 * target queries, number of active current queries,
1914 * the presence of missing targets at this delegation
1915 * point, and the given query target policy. */
1917 /* Check for the wait condition. If this is true, then
1918 * an action must be taken. */
1919 if(iq->num_target_queries==0 && iq->num_current_queries==0) {
1920 /* If there is nothing to wait for, then we need
1921 * to distinguish between generating (a) new target
1922 * query, or failing. */
1923 if(delegpt_count_missing_targets(iq->dp) > 0) {
1925 verbose(VERB_ALGO, "querying for next "
1927 if(!query_for_targets(qstate, iq, ie, id,
1929 return error_response(qstate, id,
1930 LDNS_RCODE_SERVFAIL);
1933 delegpt_count_missing_targets(iq->dp) == 0){
1934 /* it looked like there were missing
1935 * targets, but they did not turn up.
1936 * Try the bad choices again (if any),
1937 * when we get back here missing==0,
1938 * so this is not a loop. */
1941 iq->num_target_queries += qs;
1942 target_count_increase(iq, qs);
1944 /* Since a target query might have been made, we
1945 * need to check again. */
1946 if(iq->num_target_queries == 0) {
1947 /* if in capsforid fallback, instead of last
1948 * resort, we agree with the current reply
1949 * we have (if any) (our count of addrs bad)*/
1950 if(iq->caps_fallback && iq->caps_reply) {
1951 /* we're done, process the response */
1952 verbose(VERB_ALGO, "0x20 fallback had %d responses, "
1953 "but no more servers except "
1954 "last resort, done.",
1955 (int)iq->caps_server+1);
1956 iq->response = iq->caps_response;
1957 iq->caps_fallback = 0;
1958 iter_dec_attempts(iq->dp, 3); /* space for fallback */
1959 iq->num_current_queries++; /* RespState decrements it*/
1960 iq->referral_count++; /* make sure we don't loop */
1962 iq->state = QUERY_RESP_STATE;
1965 return processLastResort(qstate, iq, ie, id);
1969 /* otherwise, we have no current targets, so submerge
1970 * until one of the target or direct queries return. */
1971 if(iq->num_target_queries>0 && iq->num_current_queries>0) {
1972 verbose(VERB_ALGO, "no current targets -- waiting "
1973 "for %d targets to resolve or %d outstanding"
1974 " queries to respond", iq->num_target_queries,
1975 iq->num_current_queries);
1976 qstate->ext_state[id] = module_wait_reply;
1977 } else if(iq->num_target_queries>0) {
1978 verbose(VERB_ALGO, "no current targets -- waiting "
1979 "for %d targets to resolve.",
1980 iq->num_target_queries);
1981 qstate->ext_state[id] = module_wait_subquery;
1983 verbose(VERB_ALGO, "no current targets -- waiting "
1984 "for %d outstanding queries to respond.",
1985 iq->num_current_queries);
1986 qstate->ext_state[id] = module_wait_reply;
1991 /* if not forwarding, check ratelimits per delegationpoint name */
1992 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
1993 if(!infra_ratelimit_inc(qstate->env->infra_cache, iq->dp->name,
1994 iq->dp->namelen, *qstate->env->now)) {
1995 verbose(VERB_ALGO, "query exceeded ratelimits");
1996 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2000 if(iq->minimisation_state == INIT_MINIMISE_STATE) {
2001 /* (Re)set qinfo_out to (new) delegation point, except when
2002 * qinfo_out is already a subdomain of dp. This happens when
2003 * increasing by more than one label at once (QNAMEs with more
2004 * than MAX_MINIMISE_COUNT labels). */
2005 if(!(iq->qinfo_out.qname_len
2006 && dname_subdomain_c(iq->qchase.qname,
2007 iq->qinfo_out.qname)
2008 && dname_subdomain_c(iq->qinfo_out.qname,
2010 iq->qinfo_out.qname = iq->dp->name;
2011 iq->qinfo_out.qname_len = iq->dp->namelen;
2012 iq->qinfo_out.qtype = LDNS_RR_TYPE_A;
2013 iq->qinfo_out.qclass = iq->qchase.qclass;
2014 iq->minimise_count = 0;
2017 iq->minimisation_state = MINIMISE_STATE;
2019 if(iq->minimisation_state == MINIMISE_STATE) {
2020 int qchaselabs = dname_count_labels(iq->qchase.qname);
2021 int labdiff = qchaselabs -
2022 dname_count_labels(iq->qinfo_out.qname);
2024 iq->qinfo_out.qname = iq->qchase.qname;
2025 iq->qinfo_out.qname_len = iq->qchase.qname_len;
2026 iq->minimise_count++;
2027 iq->minimise_timeout_count = 0;
2029 iter_dec_attempts(iq->dp, 1);
2031 /* Limit number of iterations for QNAMEs with more
2032 * than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB
2033 * labels of QNAME always individually.
2035 if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 &&
2036 iq->minimise_count > MINIMISE_ONE_LAB) {
2037 if(iq->minimise_count < MAX_MINIMISE_COUNT) {
2038 int multilabs = qchaselabs - 1 -
2040 int extralabs = multilabs /
2041 MINIMISE_MULTIPLE_LABS;
2043 if (MAX_MINIMISE_COUNT - iq->minimise_count >=
2044 multilabs % MINIMISE_MULTIPLE_LABS)
2045 /* Default behaviour is to add 1 label
2046 * every iteration. Therefore, decrement
2047 * the extralabs by 1 */
2049 if (extralabs < labdiff)
2050 labdiff -= extralabs;
2054 /* Last minimised iteration, send all labels with
2061 verbose(VERB_QUERY, "removing %d labels", labdiff-1);
2062 dname_remove_labels(&iq->qinfo_out.qname,
2063 &iq->qinfo_out.qname_len,
2066 if(labdiff < 1 || (labdiff < 2
2067 && (iq->qchase.qtype == LDNS_RR_TYPE_DS
2068 || iq->qchase.qtype == LDNS_RR_TYPE_A)))
2069 /* Stop minimising this query, resolve "as usual" */
2070 iq->minimisation_state = DONOT_MINIMISE_STATE;
2072 struct dns_msg* msg = dns_cache_lookup(qstate->env,
2073 iq->qinfo_out.qname, iq->qinfo_out.qname_len,
2074 iq->qinfo_out.qtype, iq->qinfo_out.qclass,
2075 qstate->query_flags, qstate->region,
2076 qstate->env->scratch);
2077 if(msg && msg->rep->an_numrrsets == 0
2078 && FLAGS_GET_RCODE(msg->rep->flags) ==
2080 /* no need to send query if it is already
2081 * cached as NOERROR/NODATA */
2085 if(iq->minimisation_state == SKIP_MINIMISE_STATE) {
2086 iq->minimise_timeout_count++;
2087 if(iq->minimise_timeout_count < MAX_MINIMISE_TIMEOUT_COUNT)
2088 /* Do not increment qname, continue incrementing next
2090 iq->minimisation_state = MINIMISE_STATE;
2092 /* Too many time-outs detected for this QNAME and QTYPE.
2093 * We give up, disable QNAME minimisation. */
2094 iq->minimisation_state = DONOT_MINIMISE_STATE;
2096 if(iq->minimisation_state == DONOT_MINIMISE_STATE)
2097 iq->qinfo_out = iq->qchase;
2099 /* We have a valid target. */
2100 if(verbosity >= VERB_QUERY) {
2101 log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out);
2102 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
2103 &target->addr, target->addrlen);
2104 verbose(VERB_ALGO, "dnssec status: %s%s",
2105 iq->dnssec_expected?"expected": "not expected",
2106 iq->dnssec_lame_query?" but lame_query anyway": "");
2108 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
2109 outq = (*qstate->env->send_query)(
2110 iq->qinfo_out.qname, iq->qinfo_out.qname_len,
2111 iq->qinfo_out.qtype, iq->qinfo_out.qclass,
2112 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0),
2113 /* unset CD if to forwarder(RD set) and not dnssec retry
2114 * (blacklist nonempty) and no trust-anchors are configured
2115 * above the qname or on the first attempt when dnssec is on */
2116 EDNS_DO| ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&&
2117 !qstate->blacklist&&(!iter_indicates_dnssec_fwd(qstate->env,
2118 &iq->qinfo_out)||target->attempts==1)?0:BIT_CD),
2119 iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted(
2120 ie, iq), opt_list, &target->addr, target->addrlen,
2121 iq->dp->name, iq->dp->namelen, qstate);
2123 log_addr(VERB_DETAIL, "error sending query to auth server",
2124 &target->addr, target->addrlen);
2125 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok)
2126 infra_ratelimit_dec(qstate->env->infra_cache, iq->dp->name,
2127 iq->dp->namelen, *qstate->env->now);
2128 return next_state(iq, QUERYTARGETS_STATE);
2130 outbound_list_insert(&iq->outlist, outq);
2131 iq->num_current_queries++;
2133 qstate->ext_state[id] = module_wait_reply;
2138 /** find NS rrset in given list */
2139 static struct ub_packed_rrset_key*
2140 find_NS(struct reply_info* rep, size_t from, size_t to)
2143 for(i=from; i<to; i++) {
2144 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
2145 return rep->rrsets[i];
2152 * Process the query response. All queries end up at this state first. This
2153 * process generally consists of analyzing the response and routing the
2154 * event to the next state (either bouncing it back to a request state, or
2155 * terminating the processing for this event).
2157 * @param qstate: query state.
2158 * @param iq: iterator query state.
2159 * @param id: module id.
2160 * @return true if the event requires more immediate processing, false if
2161 * not. This is generally only true when forwarding the request to
2162 * the final state (i.e., on answer).
2165 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
2169 enum response_type type;
2170 iq->num_current_queries--;
2171 if(iq->response == NULL) {
2172 /* Don't increment qname when QNAME minimisation is enabled */
2173 if(qstate->env->cfg->qname_minimisation)
2174 iq->minimisation_state = SKIP_MINIMISE_STATE;
2175 iq->chase_to_rd = 0;
2176 iq->dnssec_lame_query = 0;
2177 verbose(VERB_ALGO, "query response was timeout");
2178 return next_state(iq, QUERYTARGETS_STATE);
2180 type = response_type_from_server(
2181 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
2182 iq->response, &iq->qchase, iq->dp);
2183 iq->chase_to_rd = 0;
2184 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) {
2185 /* When forwarding (RD bit is set), we handle referrals
2186 * differently. No queries should be sent elsewhere */
2187 type = RESPONSE_TYPE_ANSWER;
2189 if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected
2190 && !iq->dnssec_lame_query &&
2191 !(iq->chase_flags&BIT_RD)
2192 && iq->sent_count < DNSSEC_LAME_DETECT_COUNT
2193 && type != RESPONSE_TYPE_LAME
2194 && type != RESPONSE_TYPE_REC_LAME
2195 && type != RESPONSE_TYPE_THROWAWAY
2196 && type != RESPONSE_TYPE_UNTYPED) {
2197 /* a possible answer, see if it is missing DNSSEC */
2198 /* but not when forwarding, so we dont mark fwder lame */
2199 if(!iter_msg_has_dnssec(iq->response)) {
2200 /* Mark this address as dnsseclame in this dp,
2201 * because that will make serverselection disprefer
2202 * it, but also, once it is the only final option,
2203 * use dnssec-lame-bypass if it needs to query there.*/
2205 struct delegpt_addr* a = delegpt_find_addr(
2206 iq->dp, &qstate->reply->addr,
2207 qstate->reply->addrlen);
2208 if(a) a->dnsseclame = 1;
2210 /* test the answer is from the zone we expected,
2211 * otherwise, (due to parent,child on same server), we
2212 * might mark the server,zone lame inappropriately */
2213 if(!iter_msg_from_zone(iq->response, iq->dp, type,
2215 qstate->reply = NULL;
2216 type = RESPONSE_TYPE_LAME;
2219 } else iq->dnssec_lame_query = 0;
2220 /* see if referral brings us close to the target */
2221 if(type == RESPONSE_TYPE_REFERRAL) {
2222 struct ub_packed_rrset_key* ns = find_NS(
2223 iq->response->rep, iq->response->rep->an_numrrsets,
2224 iq->response->rep->an_numrrsets
2225 + iq->response->rep->ns_numrrsets);
2226 if(!ns) ns = find_NS(iq->response->rep, 0,
2227 iq->response->rep->an_numrrsets);
2228 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
2229 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
2230 verbose(VERB_ALGO, "bad referral, throwaway");
2231 type = RESPONSE_TYPE_THROWAWAY;
2233 iter_scrub_ds(iq->response, ns, iq->dp->name);
2234 } else iter_scrub_ds(iq->response, NULL, NULL);
2236 /* handle each of the type cases */
2237 if(type == RESPONSE_TYPE_ANSWER) {
2238 /* ANSWER type responses terminate the query algorithm,
2239 * so they sent on their */
2240 if(verbosity >= VERB_DETAIL) {
2241 verbose(VERB_DETAIL, "query response was %s",
2242 FLAGS_GET_RCODE(iq->response->rep->flags)
2243 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
2244 (iq->response->rep->an_numrrsets?"ANSWER":
2247 /* if qtype is DS, check we have the right level of answer,
2248 * like grandchild answer but we need the middle, reject it */
2249 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
2250 && !(iq->chase_flags&BIT_RD)
2251 && iter_ds_toolow(iq->response, iq->dp)
2252 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
2253 /* close down outstanding requests to be discarded */
2254 outbound_list_clear(&iq->outlist);
2255 iq->num_current_queries = 0;
2256 fptr_ok(fptr_whitelist_modenv_detach_subs(
2257 qstate->env->detach_subs));
2258 (*qstate->env->detach_subs)(qstate);
2259 iq->num_target_queries = 0;
2260 return processDSNSFind(qstate, iq, id);
2262 iter_dns_store(qstate->env, &iq->response->qinfo,
2263 iq->response->rep, 0, qstate->prefetch_leeway,
2264 iq->dp&&iq->dp->has_parent_side_NS,
2265 qstate->region, qstate->query_flags);
2266 /* close down outstanding requests to be discarded */
2267 outbound_list_clear(&iq->outlist);
2268 iq->num_current_queries = 0;
2269 fptr_ok(fptr_whitelist_modenv_detach_subs(
2270 qstate->env->detach_subs));
2271 (*qstate->env->detach_subs)(qstate);
2272 iq->num_target_queries = 0;
2274 sock_list_insert(&qstate->reply_origin,
2275 &qstate->reply->addr, qstate->reply->addrlen,
2277 if(iq->minimisation_state != DONOT_MINIMISE_STATE) {
2278 /* Best effort qname-minimisation.
2279 * Stop minimising and send full query when RCODE
2280 * is not NOERROR. */
2281 if(FLAGS_GET_RCODE(iq->response->rep->flags) !=
2283 iq->minimisation_state = DONOT_MINIMISE_STATE;
2284 if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
2285 LDNS_RCODE_NXDOMAIN) {
2286 /* Stop resolving when NXDOMAIN is DNSSEC
2287 * signed. Based on assumption that namservers
2288 * serving signed zones do not return NXDOMAIN
2289 * for empty-non-terminals. */
2290 if(iq->dnssec_expected)
2291 return final_state(iq);
2292 /* Make subrequest to validate intermediate
2293 * NXDOMAIN if harden-below-nxdomain is
2295 if(qstate->env->cfg->harden_below_nxdomain) {
2296 struct module_qstate* subq = NULL;
2297 log_query_info(VERB_QUERY,
2298 "schedule NXDOMAIN validation:",
2299 &iq->response->qinfo);
2300 if(!generate_sub_request(
2301 iq->response->qinfo.qname,
2302 iq->response->qinfo.qname_len,
2303 iq->response->qinfo.qtype,
2304 iq->response->qinfo.qclass,
2307 FINISHED_STATE, &subq, 1))
2309 "could not validate NXDOMAIN "
2313 return next_state(iq, QUERYTARGETS_STATE);
2315 return final_state(iq);
2316 } else if(type == RESPONSE_TYPE_REFERRAL) {
2317 /* REFERRAL type responses get a reset of the
2318 * delegation point, and back to the QUERYTARGETS_STATE. */
2319 verbose(VERB_DETAIL, "query response was REFERRAL");
2321 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
2322 /* we have a referral, no ratelimit, we can send
2323 * our queries to the given name */
2324 infra_ratelimit_dec(qstate->env->infra_cache,
2325 iq->dp->name, iq->dp->namelen,
2329 /* if hardened, only store referral if we asked for it */
2330 if(!qstate->env->cfg->harden_referral_path ||
2331 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
2332 && (qstate->query_flags&BIT_RD)
2333 && !(qstate->query_flags&BIT_CD)
2334 /* we know that all other NS rrsets are scrubbed
2335 * away, thus on referral only one is left.
2336 * see if that equals the query name... */
2337 && ( /* auth section, but sometimes in answer section*/
2338 reply_find_rrset_section_ns(iq->response->rep,
2339 iq->qchase.qname, iq->qchase.qname_len,
2340 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2341 || reply_find_rrset_section_an(iq->response->rep,
2342 iq->qchase.qname, iq->qchase.qname_len,
2343 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2346 /* Store the referral under the current query */
2347 /* no prefetch-leeway, since its not the answer */
2348 iter_dns_store(qstate->env, &iq->response->qinfo,
2349 iq->response->rep, 1, 0, 0, NULL, 0);
2350 if(iq->store_parent_NS)
2351 iter_store_parentside_NS(qstate->env,
2353 if(qstate->env->neg_cache)
2354 val_neg_addreferral(qstate->env->neg_cache,
2355 iq->response->rep, iq->dp->name);
2357 /* store parent-side-in-zone-glue, if directly queried for */
2358 if(iq->query_for_pside_glue && !iq->pside_glue) {
2359 iq->pside_glue = reply_find_rrset(iq->response->rep,
2360 iq->qchase.qname, iq->qchase.qname_len,
2361 iq->qchase.qtype, iq->qchase.qclass);
2362 if(iq->pside_glue) {
2363 log_rrset_key(VERB_ALGO, "found parent-side "
2364 "glue", iq->pside_glue);
2365 iter_store_parentside_rrset(qstate->env,
2370 /* Reset the event state, setting the current delegation
2371 * point to the referral. */
2372 iq->deleg_msg = iq->response;
2373 iq->dp = delegpt_from_message(iq->response, qstate->region);
2374 if (qstate->env->cfg->qname_minimisation)
2375 iq->minimisation_state = INIT_MINIMISE_STATE;
2377 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2378 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
2379 qstate->region, iq->dp))
2380 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2381 if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
2382 iq->store_parent_NS->name) == 0)
2383 iter_merge_retry_counts(iq->dp, iq->store_parent_NS);
2384 delegpt_log(VERB_ALGO, iq->dp);
2385 /* Count this as a referral. */
2386 iq->referral_count++;
2388 /* see if the next dp is a trust anchor, or a DS was sent
2389 * along, indicating dnssec is expected for next zone */
2390 iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
2391 iq->dp, iq->response, iq->qchase.qclass);
2392 /* if dnssec, validating then also fetch the key for the DS */
2393 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
2394 !(qstate->query_flags&BIT_CD))
2395 generate_dnskey_prefetch(qstate, iq, id);
2397 /* spawn off NS and addr to auth servers for the NS we just
2398 * got in the referral. This gets authoritative answer
2399 * (answer section trust level) rrset.
2400 * right after, we detach the subs, answer goes to cache. */
2401 if(qstate->env->cfg->harden_referral_path)
2402 generate_ns_check(qstate, iq, id);
2404 /* stop current outstanding queries.
2405 * FIXME: should the outstanding queries be waited for and
2406 * handled? Say by a subquery that inherits the outbound_entry.
2408 outbound_list_clear(&iq->outlist);
2409 iq->num_current_queries = 0;
2410 fptr_ok(fptr_whitelist_modenv_detach_subs(
2411 qstate->env->detach_subs));
2412 (*qstate->env->detach_subs)(qstate);
2413 iq->num_target_queries = 0;
2414 verbose(VERB_ALGO, "cleared outbound list for next round");
2415 return next_state(iq, QUERYTARGETS_STATE);
2416 } else if(type == RESPONSE_TYPE_CNAME) {
2417 uint8_t* sname = NULL;
2418 size_t snamelen = 0;
2419 /* CNAME type responses get a query restart (i.e., get a
2420 * reset of the query state and go back to INIT_REQUEST_STATE).
2422 verbose(VERB_DETAIL, "query response was CNAME");
2423 if(verbosity >= VERB_ALGO)
2424 log_dns_msg("cname msg", &iq->response->qinfo,
2426 /* if qtype is DS, check we have the right level of answer,
2427 * like grandchild answer but we need the middle, reject it */
2428 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
2429 && !(iq->chase_flags&BIT_RD)
2430 && iter_ds_toolow(iq->response, iq->dp)
2431 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
2432 outbound_list_clear(&iq->outlist);
2433 iq->num_current_queries = 0;
2434 fptr_ok(fptr_whitelist_modenv_detach_subs(
2435 qstate->env->detach_subs));
2436 (*qstate->env->detach_subs)(qstate);
2437 iq->num_target_queries = 0;
2438 return processDSNSFind(qstate, iq, id);
2440 /* Process the CNAME response. */
2441 if(!handle_cname_response(qstate, iq, iq->response,
2443 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2444 /* cache the CNAME response under the current query */
2445 /* NOTE : set referral=1, so that rrsets get stored but not
2446 * the partial query answer (CNAME only). */
2447 /* prefetchleeway applied because this updates answer parts */
2448 iter_dns_store(qstate->env, &iq->response->qinfo,
2449 iq->response->rep, 1, qstate->prefetch_leeway,
2450 iq->dp&&iq->dp->has_parent_side_NS, NULL,
2451 qstate->query_flags);
2452 /* set the current request's qname to the new value. */
2453 iq->qchase.qname = sname;
2454 iq->qchase.qname_len = snamelen;
2455 if (qstate->env->cfg->qname_minimisation)
2456 iq->minimisation_state = INIT_MINIMISE_STATE;
2457 /* Clear the query state, since this is a query restart. */
2458 iq->deleg_msg = NULL;
2460 iq->dsns_point = NULL;
2461 /* Note the query restart. */
2462 iq->query_restart_count++;
2465 /* stop current outstanding queries.
2466 * FIXME: should the outstanding queries be waited for and
2467 * handled? Say by a subquery that inherits the outbound_entry.
2469 outbound_list_clear(&iq->outlist);
2470 iq->num_current_queries = 0;
2471 fptr_ok(fptr_whitelist_modenv_detach_subs(
2472 qstate->env->detach_subs));
2473 (*qstate->env->detach_subs)(qstate);
2474 iq->num_target_queries = 0;
2476 sock_list_insert(&qstate->reply_origin,
2477 &qstate->reply->addr, qstate->reply->addrlen,
2479 verbose(VERB_ALGO, "cleared outbound list for query restart");
2480 /* go to INIT_REQUEST_STATE for new qname. */
2481 return next_state(iq, INIT_REQUEST_STATE);
2482 } else if(type == RESPONSE_TYPE_LAME) {
2483 /* Cache the LAMEness. */
2484 verbose(VERB_DETAIL, "query response was %sLAME",
2485 dnsseclame?"DNSSEC ":"");
2486 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
2487 log_err("mark lame: mismatch in qname and dpname");
2488 /* throwaway this reply below */
2489 } else if(qstate->reply) {
2490 /* need addr for lameness cache, but we may have
2491 * gotten this from cache, so test to be sure */
2492 if(!infra_set_lame(qstate->env->infra_cache,
2493 &qstate->reply->addr, qstate->reply->addrlen,
2494 iq->dp->name, iq->dp->namelen,
2495 *qstate->env->now, dnsseclame, 0,
2497 log_err("mark host lame: out of memory");
2499 } else if(type == RESPONSE_TYPE_REC_LAME) {
2500 /* Cache the LAMEness. */
2501 verbose(VERB_DETAIL, "query response REC_LAME: "
2502 "recursive but not authoritative server");
2503 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
2504 log_err("mark rec_lame: mismatch in qname and dpname");
2505 /* throwaway this reply below */
2506 } else if(qstate->reply) {
2507 /* need addr for lameness cache, but we may have
2508 * gotten this from cache, so test to be sure */
2509 verbose(VERB_DETAIL, "mark as REC_LAME");
2510 if(!infra_set_lame(qstate->env->infra_cache,
2511 &qstate->reply->addr, qstate->reply->addrlen,
2512 iq->dp->name, iq->dp->namelen,
2513 *qstate->env->now, 0, 1, iq->qchase.qtype))
2514 log_err("mark host lame: out of memory");
2516 } else if(type == RESPONSE_TYPE_THROWAWAY) {
2517 /* LAME and THROWAWAY responses are handled the same way.
2518 * In this case, the event is just sent directly back to
2519 * the QUERYTARGETS_STATE without resetting anything,
2520 * because, clearly, the next target must be tried. */
2521 verbose(VERB_DETAIL, "query response was THROWAWAY");
2523 log_warn("A query response came back with an unknown type: %d",
2527 /* LAME, THROWAWAY and "unknown" all end up here.
2528 * Recycle to the QUERYTARGETS state to hopefully try a
2529 * different target. */
2530 if (qstate->env->cfg->qname_minimisation)
2531 iq->minimisation_state = DONOT_MINIMISE_STATE;
2532 return next_state(iq, QUERYTARGETS_STATE);
2536 * Return priming query results to interested super querystates.
2538 * Sets the delegation point and delegation message (not nonRD queries).
2539 * This is a callback from walk_supers.
2541 * @param qstate: priming query state that finished.
2542 * @param id: module id.
2543 * @param forq: the qstate for which priming has been done.
2546 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
2548 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2549 struct delegpt* dp = NULL;
2551 log_assert(qstate->is_priming || foriq->wait_priming_stub);
2552 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
2553 /* Convert our response to a delegation point */
2554 dp = delegpt_from_message(qstate->return_msg, forq->region);
2556 /* if there is no convertable delegation point, then
2557 * the ANSWER type was (presumably) a negative answer. */
2558 verbose(VERB_ALGO, "prime response was not a positive "
2561 foriq->state = QUERYTARGETS_STATE;
2565 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
2566 delegpt_log(VERB_ALGO, dp);
2568 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
2569 if(!foriq->deleg_msg) {
2570 log_err("copy prime response: out of memory");
2572 foriq->state = QUERYTARGETS_STATE;
2576 /* root priming responses go to init stage 2, priming stub
2577 * responses to to stage 3. */
2578 if(foriq->wait_priming_stub) {
2579 foriq->state = INIT_REQUEST_3_STATE;
2580 foriq->wait_priming_stub = 0;
2581 } else foriq->state = INIT_REQUEST_2_STATE;
2582 /* because we are finished, the parent will be reactivated */
2586 * This handles the response to a priming query. This is used to handle both
2587 * root and stub priming responses. This is basically the equivalent of the
2588 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat
2589 * REFERRALs as ANSWERS. It will also update and reactivate the originating
2592 * @param qstate: query state.
2593 * @param id: module id.
2594 * @return true if the event needs more immediate processing, false if not.
2595 * This state always returns false.
2598 processPrimeResponse(struct module_qstate* qstate, int id)
2600 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2601 enum response_type type;
2602 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
2603 type = response_type_from_server(
2604 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
2605 iq->response, &iq->qchase, iq->dp);
2606 if(type == RESPONSE_TYPE_ANSWER) {
2607 qstate->return_rcode = LDNS_RCODE_NOERROR;
2608 qstate->return_msg = iq->response;
2610 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
2611 qstate->return_msg = NULL;
2614 /* validate the root or stub after priming (if enabled).
2615 * This is the same query as the prime query, but with validation.
2616 * Now that we are primed, the additional queries that validation
2617 * may need can be resolved, such as DLV. */
2618 if(qstate->env->cfg->harden_referral_path) {
2619 struct module_qstate* subq = NULL;
2620 log_nametypeclass(VERB_ALGO, "schedule prime validation",
2621 qstate->qinfo.qname, qstate->qinfo.qtype,
2622 qstate->qinfo.qclass);
2623 if(!generate_sub_request(qstate->qinfo.qname,
2624 qstate->qinfo.qname_len, qstate->qinfo.qtype,
2625 qstate->qinfo.qclass, qstate, id, iq,
2626 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
2627 verbose(VERB_ALGO, "could not generate prime check");
2629 generate_a_aaaa_check(qstate, iq, id);
2632 /* This event is finished. */
2633 qstate->ext_state[id] = module_finished;
2638 * Do final processing on responses to target queries. Events reach this
2639 * state after the iterative resolution algorithm terminates. This state is
2640 * responsible for reactiving the original event, and housekeeping related
2641 * to received target responses (caching, updating the current delegation
2643 * Callback from walk_supers for every super state that is interested in
2644 * the results from this query.
2646 * @param qstate: query state.
2647 * @param id: module id.
2648 * @param forq: super query state.
2651 processTargetResponse(struct module_qstate* qstate, int id,
2652 struct module_qstate* forq)
2654 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2655 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2656 struct ub_packed_rrset_key* rrset;
2657 struct delegpt_ns* dpns;
2658 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
2660 foriq->state = QUERYTARGETS_STATE;
2661 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
2662 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
2664 /* Tell the originating event that this target query has finished
2665 * (regardless if it succeeded or not). */
2666 foriq->num_target_queries--;
2668 /* check to see if parent event is still interested (in orig name). */
2670 verbose(VERB_ALGO, "subq: parent not interested, was reset");
2671 return; /* not interested anymore */
2673 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
2674 qstate->qinfo.qname_len);
2676 /* If not interested, just stop processing this event */
2677 verbose(VERB_ALGO, "subq: parent not interested anymore");
2678 /* could be because parent was jostled out of the cache,
2679 and a new identical query arrived, that does not want it*/
2683 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
2684 if(iq->pside_glue) {
2685 /* if the pside_glue is NULL, then it could not be found,
2686 * the done_pside is already set when created and a cache
2687 * entry created in processFinished so nothing to do here */
2688 log_rrset_key(VERB_ALGO, "add parentside glue to dp",
2690 if(!delegpt_add_rrset(foriq->dp, forq->region,
2692 log_err("out of memory adding pside glue");
2695 /* This response is relevant to the current query, so we
2696 * add (attempt to add, anyway) this target(s) and reactivate
2697 * the original event.
2698 * NOTE: we could only look for the AnswerRRset if the
2699 * response type was ANSWER. */
2700 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
2702 /* if CNAMEs have been followed - add new NS to delegpt. */
2703 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
2704 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
2705 rrset->rk.dname_len)) {
2706 /* if dpns->lame then set newcname ns lame too */
2707 if(!delegpt_add_ns(foriq->dp, forq->region,
2708 rrset->rk.dname, dpns->lame))
2709 log_err("out of memory adding cnamed-ns");
2711 /* if dpns->lame then set the address(es) lame too */
2712 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
2714 log_err("out of memory adding targets");
2715 verbose(VERB_ALGO, "added target response");
2716 delegpt_log(VERB_ALGO, foriq->dp);
2718 verbose(VERB_ALGO, "iterator TargetResponse failed");
2719 dpns->resolved = 1; /* fail the target */
2724 * Process response for DS NS Find queries, that attempt to find the delegation
2725 * point where we ask the DS query from.
2727 * @param qstate: query state.
2728 * @param id: module id.
2729 * @param forq: super query state.
2732 processDSNSResponse(struct module_qstate* qstate, int id,
2733 struct module_qstate* forq)
2735 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2737 /* if the finished (iq->response) query has no NS set: continue
2738 * up to look for the right dp; nothing to change, do DPNSstate */
2739 if(qstate->return_rcode != LDNS_RCODE_NOERROR)
2740 return; /* seek further */
2741 /* find the NS RRset (without allowing CNAMEs) */
2742 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
2743 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
2744 qstate->qinfo.qclass)){
2745 return; /* seek further */
2748 /* else, store as DP and continue at querytargets */
2749 foriq->state = QUERYTARGETS_STATE;
2750 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
2752 log_err("out of memory in dsns dp alloc");
2753 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
2755 /* success, go query the querytargets in the new dp (and go down) */
2759 * Process response for qclass=ANY queries for a particular class.
2760 * Append to result or error-exit.
2762 * @param qstate: query state.
2763 * @param id: module id.
2764 * @param forq: super query state.
2767 processClassResponse(struct module_qstate* qstate, int id,
2768 struct module_qstate* forq)
2770 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2771 struct dns_msg* from = qstate->return_msg;
2772 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
2773 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
2774 if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
2775 /* cause servfail for qclass ANY query */
2776 foriq->response = NULL;
2777 foriq->state = FINISHED_STATE;
2781 if(!foriq->response) {
2782 /* allocate the response: copy RCODE, sec_state */
2783 foriq->response = dns_copy_msg(from, forq->region);
2784 if(!foriq->response) {
2785 log_err("malloc failed for qclass ANY response");
2786 foriq->state = FINISHED_STATE;
2789 foriq->response->qinfo.qclass = forq->qinfo.qclass;
2790 /* qclass ANY does not receive the AA flag on replies */
2791 foriq->response->rep->authoritative = 0;
2793 struct dns_msg* to = foriq->response;
2794 /* add _from_ this response _to_ existing collection */
2795 /* if there are records, copy RCODE */
2796 /* lower sec_state if this message is lower */
2797 if(from->rep->rrset_count != 0) {
2798 size_t n = from->rep->rrset_count+to->rep->rrset_count;
2799 struct ub_packed_rrset_key** dest, **d;
2800 /* copy appropriate rcode */
2801 to->rep->flags = from->rep->flags;
2803 if(from->rep->rrset_count > RR_COUNT_MAX ||
2804 to->rep->rrset_count > RR_COUNT_MAX) {
2805 log_err("malloc failed (too many rrsets) in collect ANY");
2806 foriq->state = FINISHED_STATE;
2807 return; /* integer overflow protection */
2809 dest = regional_alloc(forq->region, sizeof(dest[0])*n);
2811 log_err("malloc failed in collect ANY");
2812 foriq->state = FINISHED_STATE;
2817 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
2819 dest += to->rep->an_numrrsets;
2820 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
2822 dest += from->rep->an_numrrsets;
2824 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
2825 to->rep->ns_numrrsets * sizeof(dest[0]));
2826 dest += to->rep->ns_numrrsets;
2827 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
2828 from->rep->ns_numrrsets * sizeof(dest[0]));
2829 dest += from->rep->ns_numrrsets;
2831 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
2832 to->rep->ns_numrrsets,
2833 to->rep->ar_numrrsets * sizeof(dest[0]));
2834 dest += to->rep->ar_numrrsets;
2835 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
2836 from->rep->ns_numrrsets,
2837 from->rep->ar_numrrsets * sizeof(dest[0]));
2839 to->rep->rrsets = d;
2840 to->rep->an_numrrsets += from->rep->an_numrrsets;
2841 to->rep->ns_numrrsets += from->rep->ns_numrrsets;
2842 to->rep->ar_numrrsets += from->rep->ar_numrrsets;
2843 to->rep->rrset_count = n;
2845 if(from->rep->security < to->rep->security) /* lowest sec */
2846 to->rep->security = from->rep->security;
2847 if(from->rep->qdcount != 0) /* insert qd if appropriate */
2848 to->rep->qdcount = from->rep->qdcount;
2849 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
2850 to->rep->ttl = from->rep->ttl;
2851 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
2852 to->rep->prefetch_ttl = from->rep->prefetch_ttl;
2855 foriq->num_current_queries --;
2856 if(foriq->num_current_queries == 0)
2857 foriq->state = FINISHED_STATE;
2861 * Collect class ANY responses and make them into one response. This
2862 * state is started and it creates queries for all classes (that have
2863 * root hints). The answers are then collected.
2865 * @param qstate: query state.
2866 * @param id: module id.
2867 * @return true if the event needs more immediate processing, false if not.
2870 processCollectClass(struct module_qstate* qstate, int id)
2872 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2873 struct module_qstate* subq;
2874 /* If qchase.qclass == 0 then send out queries for all classes.
2875 * Otherwise, do nothing (wait for all answers to arrive and the
2876 * processClassResponse to put them together, and that moves us
2877 * towards the Finished state when done. */
2878 if(iq->qchase.qclass == 0) {
2880 iq->qchase.qclass = LDNS_RR_CLASS_ANY;
2881 while(iter_get_next_root(qstate->env->hints,
2882 qstate->env->fwds, &c)) {
2883 /* generate query for this class */
2884 log_nametypeclass(VERB_ALGO, "spawn collect query",
2885 qstate->qinfo.qname, qstate->qinfo.qtype, c);
2886 if(!generate_sub_request(qstate->qinfo.qname,
2887 qstate->qinfo.qname_len, qstate->qinfo.qtype,
2888 c, qstate, id, iq, INIT_REQUEST_STATE,
2889 FINISHED_STATE, &subq,
2890 (int)!(qstate->query_flags&BIT_CD))) {
2891 return error_response(qstate, id,
2892 LDNS_RCODE_SERVFAIL);
2894 /* ignore subq, no special init required */
2895 iq->num_current_queries ++;
2900 /* if no roots are configured at all, return */
2901 if(iq->num_current_queries == 0) {
2902 verbose(VERB_ALGO, "No root hints or fwds, giving up "
2904 return error_response(qstate, id, LDNS_RCODE_REFUSED);
2906 /* return false, wait for queries to return */
2908 /* if woke up here because of an answer, wait for more answers */
2913 * This handles the final state for first-tier responses (i.e., responses to
2914 * externally generated queries).
2916 * @param qstate: query state.
2917 * @param iq: iterator query state.
2918 * @param id: module id.
2919 * @return true if the event needs more processing, false if not. Since this
2920 * is the final state for an event, it always returns false.
2923 processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
2926 log_query_info(VERB_QUERY, "finishing processing for",
2929 /* store negative cache element for parent side glue. */
2930 if(iq->query_for_pside_glue && !iq->pside_glue)
2931 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
2932 iq->deleg_msg?iq->deleg_msg->rep:
2933 (iq->response?iq->response->rep:NULL));
2935 verbose(VERB_ALGO, "No response is set, servfail");
2936 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2939 /* Make sure that the RA flag is set (since the presence of
2940 * this module means that recursion is available) */
2941 iq->response->rep->flags |= BIT_RA;
2943 /* Clear the AA flag */
2944 /* FIXME: does this action go here or in some other module? */
2945 iq->response->rep->flags &= ~BIT_AA;
2947 /* make sure QR flag is on */
2948 iq->response->rep->flags |= BIT_QR;
2950 /* we have finished processing this query */
2951 qstate->ext_state[id] = module_finished;
2953 /* TODO: we are using a private TTL, trim the response. */
2954 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
2956 /* prepend any items we have accumulated */
2957 if(iq->an_prepend_list || iq->ns_prepend_list) {
2958 if(!iter_prepend(iq, iq->response, qstate->region)) {
2959 log_err("prepend rrsets: out of memory");
2960 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2962 /* reset the query name back */
2963 iq->response->qinfo = qstate->qinfo;
2964 /* the security state depends on the combination */
2965 iq->response->rep->security = sec_status_unchecked;
2966 /* store message with the finished prepended items,
2967 * but only if we did recursion. The nonrecursion referral
2968 * from cache does not need to be stored in the msg cache. */
2969 if(qstate->query_flags&BIT_RD) {
2970 iter_dns_store(qstate->env, &qstate->qinfo,
2971 iq->response->rep, 0, qstate->prefetch_leeway,
2972 iq->dp&&iq->dp->has_parent_side_NS,
2973 qstate->region, qstate->query_flags);
2976 qstate->return_rcode = LDNS_RCODE_NOERROR;
2977 qstate->return_msg = iq->response;
2982 * Return priming query results to interestes super querystates.
2984 * Sets the delegation point and delegation message (not nonRD queries).
2985 * This is a callback from walk_supers.
2987 * @param qstate: query state that finished.
2988 * @param id: module id.
2989 * @param super: the qstate to inform.
2992 iter_inform_super(struct module_qstate* qstate, int id,
2993 struct module_qstate* super)
2995 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
2996 processClassResponse(qstate, id, super);
2997 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
2998 super->minfo[id])->state == DSNS_FIND_STATE)
2999 processDSNSResponse(qstate, id, super);
3000 else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
3001 error_supers(qstate, id, super);
3002 else if(qstate->is_priming)
3003 prime_supers(qstate, id, super);
3004 else processTargetResponse(qstate, id, super);
3008 * Handle iterator state.
3009 * Handle events. This is the real processing loop for events, responsible
3010 * for moving events through the various states. If a processing method
3011 * returns true, then it will be advanced to the next state. If false, then
3012 * processing will stop.
3014 * @param qstate: query state.
3015 * @param ie: iterator shared global environment.
3016 * @param iq: iterator query state.
3017 * @param id: module id.
3020 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
3021 struct iter_env* ie, int id)
3025 verbose(VERB_ALGO, "iter_handle processing q with state %s",
3026 iter_state_to_string(iq->state));
3028 case INIT_REQUEST_STATE:
3029 cont = processInitRequest(qstate, iq, ie, id);
3031 case INIT_REQUEST_2_STATE:
3032 cont = processInitRequest2(qstate, iq, id);
3034 case INIT_REQUEST_3_STATE:
3035 cont = processInitRequest3(qstate, iq, id);
3037 case QUERYTARGETS_STATE:
3038 cont = processQueryTargets(qstate, iq, ie, id);
3040 case QUERY_RESP_STATE:
3041 cont = processQueryResponse(qstate, iq, id);
3043 case PRIME_RESP_STATE:
3044 cont = processPrimeResponse(qstate, id);
3046 case COLLECT_CLASS_STATE:
3047 cont = processCollectClass(qstate, id);
3049 case DSNS_FIND_STATE:
3050 cont = processDSNSFind(qstate, iq, id);
3052 case FINISHED_STATE:
3053 cont = processFinished(qstate, iq, id);
3056 log_warn("iterator: invalid state: %d",
3065 * This is the primary entry point for processing request events. Note that
3066 * this method should only be used by external modules.
3067 * @param qstate: query state.
3068 * @param ie: iterator shared global environment.
3069 * @param iq: iterator query state.
3070 * @param id: module id.
3073 process_request(struct module_qstate* qstate, struct iter_qstate* iq,
3074 struct iter_env* ie, int id)
3076 /* external requests start in the INIT state, and finish using the
3077 * FINISHED state. */
3078 iq->state = INIT_REQUEST_STATE;
3079 iq->final_state = FINISHED_STATE;
3080 verbose(VERB_ALGO, "process_request: new external request event");
3081 iter_handle(qstate, iq, ie, id);
3084 /** process authoritative server reply */
3086 process_response(struct module_qstate* qstate, struct iter_qstate* iq,
3087 struct iter_env* ie, int id, struct outbound_entry* outbound,
3088 enum module_ev event)
3090 struct msg_parse* prs;
3091 struct edns_data edns;
3094 verbose(VERB_ALGO, "process_response: new external response event");
3095 iq->response = NULL;
3096 iq->state = QUERY_RESP_STATE;
3097 if(event == module_event_noreply || event == module_event_error) {
3098 if(event == module_event_noreply && iq->sent_count >= 3 &&
3099 qstate->env->cfg->use_caps_bits_for_id &&
3100 !iq->caps_fallback) {
3101 /* start fallback */
3102 iq->caps_fallback = 1;
3103 iq->caps_server = 0;
3104 iq->caps_reply = NULL;
3105 iq->caps_response = NULL;
3106 iq->state = QUERYTARGETS_STATE;
3107 iq->num_current_queries--;
3108 /* need fresh attempts for the 0x20 fallback, if
3109 * that was the cause for the failure */
3110 iter_dec_attempts(iq->dp, 3);
3111 verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback");
3116 if( (event != module_event_reply && event != module_event_capsfail)
3117 || !qstate->reply) {
3118 log_err("Bad event combined with response");
3119 outbound_list_remove(&iq->outlist, outbound);
3120 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3125 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
3126 sizeof(struct msg_parse));
3128 log_err("out of memory on incoming message");
3129 /* like packet got dropped */
3132 memset(prs, 0, sizeof(*prs));
3133 memset(&edns, 0, sizeof(edns));
3134 pkt = qstate->reply->c->buffer;
3135 sldns_buffer_set_position(pkt, 0);
3136 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
3137 verbose(VERB_ALGO, "parse error on reply packet");
3140 /* edns is not examined, but removed from message to help cache */
3141 if(parse_extract_edns(prs, &edns, qstate->env->scratch) !=
3144 /* remove CD-bit, we asked for in case we handle validation ourself */
3145 prs->flags &= ~BIT_CD;
3147 /* normalize and sanitize: easy to delete items from linked lists */
3148 if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name,
3149 qstate->env->scratch, qstate->env, ie)) {
3150 /* if 0x20 enabled, start fallback, but we have no message */
3151 if(event == module_event_capsfail && !iq->caps_fallback) {
3152 iq->caps_fallback = 1;
3153 iq->caps_server = 0;
3154 iq->caps_reply = NULL;
3155 iq->caps_response = NULL;
3156 iq->state = QUERYTARGETS_STATE;
3157 iq->num_current_queries--;
3158 verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response");
3163 /* allocate response dns_msg in region */
3164 iq->response = dns_alloc_msg(pkt, prs, qstate->region);
3167 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
3168 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
3169 &qstate->reply->addr, qstate->reply->addrlen);
3170 if(verbosity >= VERB_ALGO)
3171 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
3174 if(event == module_event_capsfail || iq->caps_fallback) {
3175 /* for fallback we care about main answer, not additionals */
3176 /* removing that makes comparison more likely to succeed */
3177 caps_strip_reply(iq->response->rep);
3178 if(!iq->caps_fallback) {
3179 /* start fallback */
3180 iq->caps_fallback = 1;
3181 iq->caps_server = 0;
3182 iq->caps_reply = iq->response->rep;
3183 iq->caps_response = iq->response;
3184 iq->state = QUERYTARGETS_STATE;
3185 iq->num_current_queries--;
3186 verbose(VERB_DETAIL, "Capsforid: starting fallback");
3189 /* check if reply is the same, otherwise, fail */
3190 if(!iq->caps_reply) {
3191 iq->caps_reply = iq->response->rep;
3192 iq->caps_response = iq->response;
3193 iq->caps_server = -1; /*become zero at ++,
3194 so that we start the full set of trials */
3195 } else if(caps_failed_rcode(iq->caps_reply) &&
3196 !caps_failed_rcode(iq->response->rep)) {
3197 /* prefer to upgrade to non-SERVFAIL */
3198 iq->caps_reply = iq->response->rep;
3199 iq->caps_response = iq->response;
3200 } else if(!caps_failed_rcode(iq->caps_reply) &&
3201 caps_failed_rcode(iq->response->rep)) {
3202 /* if we have non-SERVFAIL as answer then
3203 * we can ignore SERVFAILs for the equality
3205 /* no instructions here, skip other else */
3206 } else if(caps_failed_rcode(iq->caps_reply) &&
3207 caps_failed_rcode(iq->response->rep)) {
3208 /* failure is same as other failure in fallbk*/
3209 /* no instructions here, skip other else */
3210 } else if(!reply_equal(iq->response->rep, iq->caps_reply,
3211 qstate->env->scratch)) {
3212 verbose(VERB_DETAIL, "Capsforid fallback: "
3213 "getting different replies, failed");
3214 outbound_list_remove(&iq->outlist, outbound);
3215 (void)error_response(qstate, id,
3216 LDNS_RCODE_SERVFAIL);
3219 /* continue the fallback procedure at next server */
3221 iq->state = QUERYTARGETS_STATE;
3222 iq->num_current_queries--;
3223 verbose(VERB_DETAIL, "Capsforid: reply is equal. "
3224 "go to next fallback");
3228 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
3231 outbound_list_remove(&iq->outlist, outbound);
3232 iter_handle(qstate, iq, ie, id);
3236 iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
3237 struct outbound_entry* outbound)
3239 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
3240 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3241 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
3242 id, strextstate(qstate->ext_state[id]), strmodulevent(event));
3243 if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
3245 if(iq && qstate->qinfo.qname != iq->qchase.qname)
3246 log_query_info(VERB_QUERY, "iterator operate: chased to",
3249 /* perform iterator state machine */
3250 if((event == module_event_new || event == module_event_pass) &&
3252 if(!iter_new(qstate, id)) {
3253 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3256 iq = (struct iter_qstate*)qstate->minfo[id];
3257 process_request(qstate, iq, ie, id);
3260 if(iq && event == module_event_pass) {
3261 iter_handle(qstate, iq, ie, id);
3264 if(iq && outbound) {
3265 process_response(qstate, iq, ie, id, outbound, event);
3268 if(event == module_event_error) {
3269 verbose(VERB_ALGO, "got called with event error, giving up");
3270 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3274 log_err("bad event for iterator");
3275 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3279 iter_clear(struct module_qstate* qstate, int id)
3281 struct iter_qstate* iq;
3284 iq = (struct iter_qstate*)qstate->minfo[id];
3286 outbound_list_clear(&iq->outlist);
3287 if(iq->target_count && --iq->target_count[0] == 0)
3288 free(iq->target_count);
3289 iq->num_current_queries = 0;
3291 qstate->minfo[id] = NULL;
3295 iter_get_mem(struct module_env* env, int id)
3297 struct iter_env* ie = (struct iter_env*)env->modinfo[id];
3300 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
3301 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
3305 * The iterator function block
3307 static struct module_func_block iter_block = {
3309 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
3310 &iter_clear, &iter_get_mem
3313 struct module_func_block*
3314 iter_get_funcblock(void)
3320 iter_state_to_string(enum iter_state state)
3324 case INIT_REQUEST_STATE :
3325 return "INIT REQUEST STATE";
3326 case INIT_REQUEST_2_STATE :
3327 return "INIT REQUEST STATE (stage 2)";
3328 case INIT_REQUEST_3_STATE:
3329 return "INIT REQUEST STATE (stage 3)";
3330 case QUERYTARGETS_STATE :
3331 return "QUERY TARGETS STATE";
3332 case PRIME_RESP_STATE :
3333 return "PRIME RESPONSE STATE";
3334 case COLLECT_CLASS_STATE :
3335 return "COLLECT CLASS STATE";
3336 case DSNS_FIND_STATE :
3337 return "DSNS FIND STATE";
3338 case QUERY_RESP_STATE :
3339 return "QUERY RESPONSE STATE";
3340 case FINISHED_STATE :
3341 return "FINISHED RESPONSE STATE";
3343 return "UNKNOWN ITER STATE";
3348 iter_state_is_responsestate(enum iter_state s)
3351 case INIT_REQUEST_STATE :
3352 case INIT_REQUEST_2_STATE :
3353 case INIT_REQUEST_3_STATE :
3354 case QUERYTARGETS_STATE :
3355 case COLLECT_CLASS_STATE :