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 LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
39 * This file contains a module that performs recusive iterative DNS query
44 #include <ldns/ldns.h>
45 #include "iterator/iterator.h"
46 #include "iterator/iter_utils.h"
47 #include "iterator/iter_hints.h"
48 #include "iterator/iter_fwd.h"
49 #include "iterator/iter_donotq.h"
50 #include "iterator/iter_delegpt.h"
51 #include "iterator/iter_resptype.h"
52 #include "iterator/iter_scrub.h"
53 #include "iterator/iter_priv.h"
54 #include "validator/val_neg.h"
55 #include "services/cache/dns.h"
56 #include "services/cache/infra.h"
57 #include "util/module.h"
58 #include "util/netevent.h"
59 #include "util/net_help.h"
60 #include "util/regional.h"
61 #include "util/data/dname.h"
62 #include "util/data/msgencode.h"
63 #include "util/fptr_wlist.h"
64 #include "util/config_file.h"
67 iter_init(struct module_env* env, int id)
69 struct iter_env* iter_env = (struct iter_env*)calloc(1,
70 sizeof(struct iter_env));
72 log_err("malloc failure");
75 env->modinfo[id] = (void*)iter_env;
76 if(!iter_apply_cfg(iter_env, env->cfg)) {
77 log_err("iterator: could not apply configuration settings.");
84 iter_deinit(struct module_env* env, int id)
86 struct iter_env* iter_env;
87 if(!env || !env->modinfo[id])
89 iter_env = (struct iter_env*)env->modinfo[id];
90 free(iter_env->target_fetch_policy);
91 priv_delete(iter_env->priv);
92 donotq_delete(iter_env->donotq);
94 env->modinfo[id] = NULL;
97 /** new query for iterator */
99 iter_new(struct module_qstate* qstate, int id)
101 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc(
102 qstate->region, sizeof(struct iter_qstate));
103 qstate->minfo[id] = iq;
106 memset(iq, 0, sizeof(*iq));
107 iq->state = INIT_REQUEST_STATE;
108 iq->final_state = FINISHED_STATE;
109 iq->an_prepend_list = NULL;
110 iq->an_prepend_last = NULL;
111 iq->ns_prepend_list = NULL;
112 iq->ns_prepend_last = NULL;
115 iq->num_target_queries = 0;
116 iq->num_current_queries = 0;
117 iq->query_restart_count = 0;
118 iq->referral_count = 0;
120 iq->wait_priming_stub = 0;
121 iq->refetch_glue = 0;
122 iq->dnssec_expected = 0;
123 iq->dnssec_lame_query = 0;
124 iq->chase_flags = qstate->query_flags;
125 /* Start with the (current) qname. */
126 iq->qchase = qstate->qinfo;
127 outbound_list_init(&iq->outlist);
132 * Transition to the next state. This can be used to advance a currently
133 * processing event. It cannot be used to reactivate a forEvent.
135 * @param iq: iterator query state
136 * @param nextstate The state to transition to.
137 * @return true. This is so this can be called as the return value for the
138 * actual process*State() methods. (Transitioning to the next state
139 * implies further processing).
142 next_state(struct iter_qstate* iq, enum iter_state nextstate)
144 /* If transitioning to a "response" state, make sure that there is a
146 if(iter_state_is_responsestate(nextstate)) {
147 if(iq->response == NULL) {
148 log_err("transitioning to response state sans "
152 iq->state = nextstate;
157 * Transition an event to its final state. Final states always either return
158 * a result up the module chain, or reactivate a dependent event. Which
159 * final state to transtion to is set in the module state for the event when
160 * it was created, and depends on the original purpose of the event.
162 * The response is stored in the qstate->buf buffer.
164 * @param iq: iterator query state
165 * @return false. This is so this method can be used as the return value for
166 * the processState methods. (Transitioning to the final state
169 final_state(struct iter_qstate* iq)
171 return next_state(iq, iq->final_state);
175 * Callback routine to handle errors in parent query states
176 * @param qstate: query state that failed.
177 * @param id: module id.
178 * @param super: super state.
181 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
183 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
185 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
186 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
187 /* mark address as failed. */
188 struct delegpt_ns* dpns = NULL;
190 dpns = delegpt_find_ns(super_iq->dp,
191 qstate->qinfo.qname, qstate->qinfo.qname_len);
194 verbose(VERB_ALGO, "subq error, but not interested");
195 log_query_info(VERB_ALGO, "superq", &super->qinfo);
197 delegpt_log(VERB_ALGO, super_iq->dp);
201 /* see if the failure did get (parent-lame) info */
202 if(!cache_fill_missing(super->env,
203 super_iq->qchase.qclass, super->region,
205 log_err("out of memory adding missing");
207 dpns->resolved = 1; /* mark as failed */
208 super_iq->num_target_queries--;
210 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
211 /* prime failed to get delegation */
214 /* evaluate targets again */
215 super_iq->state = QUERYTARGETS_STATE;
216 /* super becomes runnable, and will process this change */
220 * Return an error to the client
221 * @param qstate: our query state
222 * @param id: module id
223 * @param rcode: error code (DNS errcode).
224 * @return: 0 for use by caller, to make notation easy, like:
225 * return error_response(..).
228 error_response(struct module_qstate* qstate, int id, int rcode)
230 verbose(VERB_QUERY, "return error response %s",
231 ldns_lookup_by_id(ldns_rcodes, rcode)?
232 ldns_lookup_by_id(ldns_rcodes, rcode)->name:"??");
233 qstate->return_rcode = rcode;
234 qstate->return_msg = NULL;
235 qstate->ext_state[id] = module_finished;
240 * Return an error to the client and cache the error code in the
241 * message cache (so per qname, qtype, qclass).
242 * @param qstate: our query state
243 * @param id: module id
244 * @param rcode: error code (DNS errcode).
245 * @return: 0 for use by caller, to make notation easy, like:
246 * return error_response(..).
249 error_response_cache(struct module_qstate* qstate, int id, int rcode)
252 struct reply_info err;
253 memset(&err, 0, sizeof(err));
254 err.flags = (uint16_t)(BIT_QR | BIT_RA);
255 FLAGS_SET_RCODE(err.flags, rcode);
258 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
259 /* do not waste time trying to validate this servfail */
260 err.security = sec_status_indeterminate;
261 verbose(VERB_ALGO, "store error response in message cache");
262 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL);
263 return error_response(qstate, id, rcode);
266 /** check if prepend item is duplicate item */
268 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
269 struct ub_packed_rrset_key* dup)
272 for(i=0; i<to; i++) {
273 if(sets[i]->rk.type == dup->rk.type &&
274 sets[i]->rk.rrset_class == dup->rk.rrset_class &&
275 sets[i]->rk.dname_len == dup->rk.dname_len &&
276 query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
283 /** prepend the prepend list in the answer and authority section of dns_msg */
285 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
286 struct regional* region)
288 struct iter_prep_list* p;
289 struct ub_packed_rrset_key** sets;
290 size_t num_an = 0, num_ns = 0;;
291 for(p = iq->an_prepend_list; p; p = p->next)
293 for(p = iq->ns_prepend_list; p; p = p->next)
295 if(num_an + num_ns == 0)
297 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
298 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) *
299 sizeof(struct ub_packed_rrset_key*));
304 for(p = iq->an_prepend_list; p; p = p->next) {
305 sets[num_an++] = p->rrset;
307 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
308 sizeof(struct ub_packed_rrset_key*));
311 for(p = iq->ns_prepend_list; p; p = p->next) {
312 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
313 num_ns, p->rrset) || prepend_is_duplicate(
314 msg->rep->rrsets+msg->rep->an_numrrsets,
315 msg->rep->ns_numrrsets, p->rrset))
317 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
319 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
320 msg->rep->rrsets + msg->rep->an_numrrsets,
321 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
322 sizeof(struct ub_packed_rrset_key*));
324 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
325 * this is what recursors should give. */
326 msg->rep->rrset_count += num_an + num_ns;
327 msg->rep->an_numrrsets += num_an;
328 msg->rep->ns_numrrsets += num_ns;
329 msg->rep->rrsets = sets;
334 * Add rrset to ANSWER prepend list
335 * @param qstate: query state.
336 * @param iq: iterator query state.
337 * @param rrset: rrset to add.
338 * @return false on failure (malloc).
341 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq,
342 struct ub_packed_rrset_key* rrset)
344 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
345 qstate->region, sizeof(struct iter_prep_list));
351 if(iq->an_prepend_last)
352 iq->an_prepend_last->next = p;
353 else iq->an_prepend_list = p;
354 iq->an_prepend_last = p;
359 * Add rrset to AUTHORITY prepend list
360 * @param qstate: query state.
361 * @param iq: iterator query state.
362 * @param rrset: rrset to add.
363 * @return false on failure (malloc).
366 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq,
367 struct ub_packed_rrset_key* rrset)
369 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
370 qstate->region, sizeof(struct iter_prep_list));
376 if(iq->ns_prepend_last)
377 iq->ns_prepend_last->next = p;
378 else iq->ns_prepend_list = p;
379 iq->ns_prepend_last = p;
384 * Given a CNAME response (defined as a response containing a CNAME or DNAME
385 * that does not answer the request), process the response, modifying the
386 * state as necessary. This follows the CNAME/DNAME chain and returns the
389 * sets the new query name, after following the CNAME/DNAME chain.
390 * @param qstate: query state.
391 * @param iq: iterator query state.
392 * @param msg: the response.
393 * @param mname: returned target new query name.
394 * @param mname_len: length of mname.
395 * @return false on (malloc) error.
398 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
399 struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
402 /* Start with the (current) qname. */
403 *mname = iq->qchase.qname;
404 *mname_len = iq->qchase.qname_len;
406 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
408 for(i=0; i<msg->rep->an_numrrsets; i++) {
409 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
410 /* If there is a (relevant) DNAME, add it to the list.
411 * We always expect there to be CNAME that was generated
412 * by this DNAME following, so we don't process the DNAME
414 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
415 dname_strict_subdomain_c(*mname, r->rk.dname)) {
416 if(!iter_add_prepend_answer(qstate, iq, r))
421 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
422 query_dname_compare(*mname, r->rk.dname) == 0) {
423 /* Add this relevant CNAME rrset to the prepend list.*/
424 if(!iter_add_prepend_answer(qstate, iq, r))
426 get_cname_target(r, mname, mname_len);
429 /* Other rrsets in the section are ignored. */
431 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */
432 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
433 msg->rep->ns_numrrsets; i++) {
434 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
435 /* only add NSEC/NSEC3, as they may be needed for validation */
436 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
437 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
438 if(!iter_add_prepend_auth(qstate, iq, r))
446 * Generate a subrequest.
447 * Generate a local request event. Local events are tied to this module, and
448 * have a correponding (first tier) event that is waiting for this event to
449 * resolve to continue.
451 * @param qname The query name for this request.
452 * @param qnamelen length of qname
453 * @param qtype The query type for this request.
454 * @param qclass The query class for this request.
455 * @param qstate The event that is generating this event.
456 * @param id: module id.
457 * @param iq: The iterator state that is generating this event.
458 * @param initial_state The initial response state (normally this
459 * is QUERY_RESP_STATE, unless it is known that the request won't
460 * need iterative processing
461 * @param finalstate The final state for the response to this request.
462 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
463 * not need initialisation.
464 * @param v: if true, validation is done on the subquery.
465 * @return false on error (malloc).
468 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
469 uint16_t qclass, struct module_qstate* qstate, int id,
470 struct iter_qstate* iq, enum iter_state initial_state,
471 enum iter_state finalstate, struct module_qstate** subq_ret, int v)
473 struct module_qstate* subq = NULL;
474 struct iter_qstate* subiq = NULL;
475 uint16_t qflags = 0; /* OPCODE QUERY, no flags */
476 struct query_info qinf;
477 int prime = (finalstate == PRIME_RESP_STATE)?1:0;
479 qinf.qname_len = qnamelen;
481 qinf.qclass = qclass;
483 /* RD should be set only when sending the query back through the INIT
485 if(initial_state == INIT_REQUEST_STATE)
487 /* We set the CD flag so we can send this through the "head" of
488 * the resolution chain, which might have a validator. We are
489 * uninterested in validating things not on the direct resolution
494 /* attach subquery, lookup existing or make a new one */
495 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
496 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime, &subq)) {
501 /* initialise the new subquery */
503 subq->ext_state[id] = module_state_initial;
504 subq->minfo[id] = regional_alloc(subq->region,
505 sizeof(struct iter_qstate));
506 if(!subq->minfo[id]) {
507 log_err("init subq: out of memory");
508 fptr_ok(fptr_whitelist_modenv_kill_sub(
509 qstate->env->kill_sub));
510 (*qstate->env->kill_sub)(subq);
513 subiq = (struct iter_qstate*)subq->minfo[id];
514 memset(subiq, 0, sizeof(*subiq));
515 subiq->num_target_queries = 0;
516 subiq->num_current_queries = 0;
517 subiq->depth = iq->depth+1;
518 outbound_list_init(&subiq->outlist);
519 subiq->state = initial_state;
520 subiq->final_state = finalstate;
521 subiq->qchase = subq->qinfo;
522 subiq->chase_flags = subq->query_flags;
523 subiq->refetch_glue = 0;
529 * Generate and send a root priming request.
530 * @param qstate: the qtstate that triggered the need to prime.
531 * @param iq: iterator query state.
532 * @param id: module id.
533 * @param qclass: the class to prime.
534 * @return 0 on failure
537 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
541 struct module_qstate* subq;
542 verbose(VERB_DETAIL, "priming . %s NS",
543 ldns_lookup_by_id(ldns_rr_classes, (int)qclass)?
544 ldns_lookup_by_id(ldns_rr_classes, (int)qclass)->name:"??");
545 dp = hints_lookup_root(qstate->env->hints, qclass);
547 verbose(VERB_ALGO, "Cannot prime due to lack of hints");
550 /* Priming requests start at the QUERYTARGETS state, skipping
551 * the normal INIT state logic (which would cause an infloop). */
552 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
553 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
555 verbose(VERB_ALGO, "could not prime root");
559 struct iter_qstate* subiq =
560 (struct iter_qstate*)subq->minfo[id];
561 /* Set the initial delegation point to the hint.
562 * copy dp, it is now part of the root prime query.
563 * dp was part of in the fixed hints structure. */
564 subiq->dp = delegpt_copy(dp, subq->region);
566 log_err("out of memory priming root, copydp");
567 fptr_ok(fptr_whitelist_modenv_kill_sub(
568 qstate->env->kill_sub));
569 (*qstate->env->kill_sub)(subq);
572 /* there should not be any target queries. */
573 subiq->num_target_queries = 0;
574 subiq->dnssec_expected = iter_indicates_dnssec(
575 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
578 /* this module stops, our submodule starts, and does the query. */
579 qstate->ext_state[id] = module_wait_subquery;
584 * Generate and process a stub priming request. This method tests for the
585 * need to prime a stub zone, so it is safe to call for every request.
587 * @param qstate: the qtstate that triggered the need to prime.
588 * @param iq: iterator query state.
589 * @param id: module id.
590 * @param qname: request name.
591 * @param qclass: request class.
592 * @return true if a priming subrequest was made, false if not. The will only
593 * issue a priming request if it detects an unprimed stub.
594 * Uses value of 2 to signal during stub-prime in root-prime situation
595 * that a noprime-stub is available and resolution can continue.
598 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id,
599 uint8_t* qname, uint16_t qclass)
601 /* Lookup the stub hint. This will return null if the stub doesn't
602 * need to be re-primed. */
603 struct iter_hints_stub* stub;
604 struct delegpt* stub_dp;
605 struct module_qstate* subq;
608 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
609 /* The stub (if there is one) does not need priming. */
614 /* is it a noprime stub (always use) */
617 if(iq->dp == NULL) r = 2;
618 /* copy the dp out of the fixed hints structure, so that
619 * it can be changed when servicing this query */
620 iq->dp = delegpt_copy(stub_dp, qstate->region);
622 log_err("out of memory priming stub");
623 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
624 return 1; /* return 1 to make module stop, with error */
626 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
627 LDNS_RR_TYPE_NS, qclass);
631 /* Otherwise, we need to (re)prime the stub. */
632 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name,
633 LDNS_RR_TYPE_NS, qclass);
635 /* Stub priming events start at the QUERYTARGETS state to avoid the
636 * redundant INIT state processing. */
637 if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
638 LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
639 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0)) {
640 verbose(VERB_ALGO, "could not prime stub");
641 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
642 return 1; /* return 1 to make module stop, with error */
645 struct iter_qstate* subiq =
646 (struct iter_qstate*)subq->minfo[id];
648 /* Set the initial delegation point to the hint. */
649 /* make copy to avoid use of stub dp by different qs/threads */
650 subiq->dp = delegpt_copy(stub_dp, subq->region);
652 log_err("out of memory priming stub, copydp");
653 fptr_ok(fptr_whitelist_modenv_kill_sub(
654 qstate->env->kill_sub));
655 (*qstate->env->kill_sub)(subq);
656 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
657 return 1; /* return 1 to make module stop, with error */
659 /* there should not be any target queries -- although there
660 * wouldn't be anyway, since stub hints never have
661 * missing targets. */
662 subiq->num_target_queries = 0;
663 subiq->wait_priming_stub = 1;
664 subiq->dnssec_expected = iter_indicates_dnssec(
665 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
668 /* this module stops, our submodule starts, and does the query. */
669 qstate->ext_state[id] = module_wait_subquery;
674 * Generate A and AAAA checks for glue that is in-zone for the referral
675 * we just got to obtain authoritative information on the adresses.
677 * @param qstate: the qtstate that triggered the need to prime.
678 * @param iq: iterator query state.
679 * @param id: module id.
682 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
685 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
686 struct module_qstate* subq;
688 struct reply_info* rep = iq->response->rep;
689 struct ub_packed_rrset_key* s;
692 if(iq->depth == ie->max_dependency_depth)
694 /* walk through additional, and check if in-zone,
695 * only relevant A, AAAA are left after scrub anyway */
696 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
698 /* check *ALL* addresses that are transmitted in additional*/
699 /* is it an address ? */
700 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
701 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
704 /* is this query the same as the A/AAAA check for it */
705 if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
706 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
707 query_dname_compare(qstate->qinfo.qname,
709 (qstate->query_flags&BIT_RD) &&
710 !(qstate->query_flags&BIT_CD))
713 /* generate subrequest for it */
714 log_nametypeclass(VERB_ALGO, "schedule addr fetch",
715 s->rk.dname, ntohs(s->rk.type),
716 ntohs(s->rk.rrset_class));
717 if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
718 ntohs(s->rk.type), ntohs(s->rk.rrset_class),
720 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
721 verbose(VERB_ALGO, "could not generate addr check");
724 /* ignore subq - not need for more init */
729 * Generate a NS check request to obtain authoritative information
732 * @param qstate: the qtstate that triggered the need to prime.
733 * @param iq: iterator query state.
734 * @param id: module id.
737 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
739 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
740 struct module_qstate* subq;
743 if(iq->depth == ie->max_dependency_depth)
745 /* is this query the same as the nscheck? */
746 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
747 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
748 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
749 /* spawn off A, AAAA queries for in-zone glue to check */
750 generate_a_aaaa_check(qstate, iq, id);
754 log_nametypeclass(VERB_ALGO, "schedule ns fetch",
755 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
756 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
757 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
758 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
759 verbose(VERB_ALGO, "could not generate ns check");
763 struct iter_qstate* subiq =
764 (struct iter_qstate*)subq->minfo[id];
766 /* make copy to avoid use of stub dp by different qs/threads */
767 /* refetch glue to start higher up the tree */
768 subiq->refetch_glue = 1;
769 subiq->dp = delegpt_copy(iq->dp, subq->region);
771 log_err("out of memory generating ns check, copydp");
772 fptr_ok(fptr_whitelist_modenv_kill_sub(
773 qstate->env->kill_sub));
774 (*qstate->env->kill_sub)(subq);
781 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
782 * just got in a referral (where we have dnssec_expected, thus have trust
783 * anchors above it). Note that right after calling this routine the
784 * iterator detached subqueries (because of following the referral), and thus
785 * the DNSKEY query becomes detached, its return stored in the cache for
786 * later lookup by the validator. This cache lookup by the validator avoids
787 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
788 * performed at about the same time the original query is sent to the domain,
789 * thus the two answers are likely to be returned at about the same time,
790 * saving a roundtrip from the validated lookup.
792 * @param qstate: the qtstate that triggered the need to prime.
793 * @param iq: iterator query state.
794 * @param id: module id.
797 generate_dnskey_prefetch(struct module_qstate* qstate,
798 struct iter_qstate* iq, int id)
800 struct module_qstate* subq;
803 /* is this query the same as the prefetch? */
804 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
805 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
806 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
810 /* if the DNSKEY is in the cache this lookup will stop quickly */
811 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
812 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
813 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
814 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
815 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
816 /* we'll be slower, but it'll work */
817 verbose(VERB_ALGO, "could not generate dnskey prefetch");
821 struct iter_qstate* subiq =
822 (struct iter_qstate*)subq->minfo[id];
823 /* this qstate has the right delegation for the dnskey lookup*/
824 /* make copy to avoid use of stub dp by different qs/threads */
825 subiq->dp = delegpt_copy(iq->dp, subq->region);
826 /* if !subiq->dp, it'll start from the cache, no problem */
831 * See if the query needs forwarding.
833 * @param qstate: query state.
834 * @param iq: iterator query state.
835 * @return true if the request is forwarded, false if not.
836 * If returns true but, iq->dp is NULL then a malloc failure occurred.
839 forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
842 uint8_t* delname = iq->qchase.qname;
843 size_t delnamelen = iq->qchase.qname_len;
844 if(iq->refetch_glue) {
845 delname = iq->dp->name;
846 delnamelen = iq->dp->namelen;
848 /* strip one label off of DS query to lookup higher for it */
849 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
850 && !dname_is_root(iq->qchase.qname))
851 dname_remove_label(&delname, &delnamelen);
852 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
855 /* send recursion desired to forward addr */
856 iq->chase_flags |= BIT_RD;
857 iq->dp = delegpt_copy(dp, qstate->region);
858 /* iq->dp checked by caller */
859 verbose(VERB_ALGO, "forwarding request");
864 * Process the initial part of the request handling. This state roughly
865 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2
866 * (find the best servers to ask).
868 * Note that all requests start here, and query restarts revisit this state.
870 * This state either generates: 1) a response, from cache or error, 2) a
871 * priming event, or 3) forwards the request to the next state (init2,
874 * @param qstate: query state.
875 * @param iq: iterator query state.
876 * @param ie: iterator shared global environment.
877 * @param id: module id.
878 * @return true if the event needs more request processing immediately,
882 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
883 struct iter_env* ie, int id)
889 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
892 /* We enforce a maximum number of query restarts. This is primarily a
893 * cheap way to prevent CNAME loops. */
894 if(iq->query_restart_count > MAX_RESTART_COUNT) {
895 verbose(VERB_QUERY, "request has exceeded the maximum number"
896 " of query restarts with %d", iq->query_restart_count);
897 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
900 /* We enforce a maximum recursion/dependency depth -- in general,
901 * this is unnecessary for dependency loops (although it will
902 * catch those), but it provides a sensible limit to the amount
903 * of work required to answer a given query. */
904 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
905 if(iq->depth > ie->max_dependency_depth) {
906 verbose(VERB_QUERY, "request has exceeded the maximum "
907 "dependency depth with depth of %d", iq->depth);
908 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
911 /* If the request is qclass=ANY, setup to generate each class */
912 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
913 iq->qchase.qclass = 0;
914 return next_state(iq, COLLECT_CLASS_STATE);
917 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */
919 /* This either results in a query restart (CNAME cache response), a
920 * terminating response (ANSWER), or a cache miss (null). */
922 if(qstate->blacklist) {
923 /* if cache, or anything else, was blacklisted then
924 * getting older results from cache is a bad idea, no cache */
925 verbose(VERB_ALGO, "cache blacklisted, going to the network");
928 msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
929 iq->qchase.qname_len, iq->qchase.qtype,
930 iq->qchase.qclass, qstate->region, qstate->env->scratch);
931 if(!msg && qstate->env->neg_cache) {
932 /* lookup in negative cache; may result in
933 * NOERROR/NODATA or NXDOMAIN answers that need validation */
934 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
935 qstate->region, qstate->env->rrset_cache,
936 qstate->env->scratch_buffer,
937 *qstate->env->now, 1/*add SOA*/, NULL);
939 /* item taken from cache does not match our query name, thus
940 * security needs to be re-examined later */
941 if(msg && query_dname_compare(qstate->qinfo.qname,
942 iq->qchase.qname) != 0)
943 msg->rep->security = sec_status_unchecked;
946 /* handle positive cache response */
947 enum response_type type = response_type_from_cache(msg,
949 if(verbosity >= VERB_ALGO) {
950 log_dns_msg("msg from cache lookup", &msg->qinfo,
952 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
954 (int)msg->rep->prefetch_ttl);
957 if(type == RESPONSE_TYPE_CNAME) {
960 verbose(VERB_ALGO, "returning CNAME response from "
962 if(!handle_cname_response(qstate, iq, msg,
964 return error_response(qstate, id,
965 LDNS_RCODE_SERVFAIL);
966 iq->qchase.qname = sname;
967 iq->qchase.qname_len = slen;
968 /* This *is* a query restart, even if it is a cheap
971 iq->refetch_glue = 0;
972 iq->query_restart_count++;
974 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
975 return next_state(iq, INIT_REQUEST_STATE);
978 /* if from cache, NULL, else insert 'cache IP' len=0 */
979 if(qstate->reply_origin)
980 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
981 /* it is an answer, response, to final state */
982 verbose(VERB_ALGO, "returning answer from cache.");
984 return final_state(iq);
987 /* attempt to forward the request */
988 if(forward_request(qstate, iq))
991 log_err("alloc failure for forward dp");
992 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
994 iq->refetch_glue = 0;
995 /* the request has been forwarded.
996 * forwarded requests need to be immediately sent to the
997 * next state, QUERYTARGETS. */
998 return next_state(iq, QUERYTARGETS_STATE);
1001 /* Resolver Algorithm Step 2 -- find the "best" servers. */
1003 /* first, adjust for DS queries. To avoid the grandparent problem,
1004 * we just look for the closest set of server to the parent of qname.
1005 * When re-fetching glue we also need to ask the parent.
1007 if(iq->refetch_glue) {
1009 log_err("internal or malloc fail: no dp for refetch");
1010 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1012 delname = iq->dp->name;
1013 delnamelen = iq->dp->namelen;
1015 delname = iq->qchase.qname;
1016 delnamelen = iq->qchase.qname_len;
1018 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
1019 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway)) {
1020 /* remove first label from delname, root goes to hints,
1021 * but only to fetch glue, not for qtype=DS. */
1022 /* also when prefetching an NS record, fetch it again from
1023 * its parent, just as if it expired, so that you do not
1024 * get stuck on an older nameserver that gives old NSrecords */
1025 if(dname_is_root(delname) && (iq->refetch_glue ||
1026 (iq->qchase.qtype == LDNS_RR_TYPE_NS &&
1027 qstate->prefetch_leeway)))
1028 delname = NULL; /* go to root priming */
1029 else dname_remove_label(&delname, &delnamelen);
1031 /* delname is the name to lookup a delegation for. If NULL rootprime */
1034 /* Lookup the delegation in the cache. If null, then the
1035 * cache needs to be primed for the qclass. */
1037 iq->dp = dns_cache_find_delegation(qstate->env, delname,
1038 delnamelen, iq->qchase.qtype, iq->qchase.qclass,
1039 qstate->region, &iq->deleg_msg,
1040 *qstate->env->now+qstate->prefetch_leeway);
1043 /* If the cache has returned nothing, then we have a
1044 * root priming situation. */
1045 if(iq->dp == NULL) {
1046 /* if there is a stub, then no root prime needed */
1047 int r = prime_stub(qstate, iq, id, delname,
1050 break; /* got noprime-stub-zone, continue */
1052 return 0; /* stub prime request made */
1053 if(forwards_lookup_root(qstate->env->fwds,
1054 iq->qchase.qclass)) {
1055 /* forward zone root, no root prime needed */
1056 /* fill in some dp - safety belt */
1057 iq->dp = hints_lookup_root(qstate->env->hints,
1060 log_err("internal error: no hints dp");
1061 return error_response(qstate, id,
1062 LDNS_RCODE_SERVFAIL);
1064 iq->dp = delegpt_copy(iq->dp, qstate->region);
1066 log_err("out of memory in safety belt");
1067 return error_response(qstate, id,
1068 LDNS_RCODE_SERVFAIL);
1070 return next_state(iq, INIT_REQUEST_2_STATE);
1072 /* Note that the result of this will set a new
1073 * DelegationPoint based on the result of priming. */
1074 if(!prime_root(qstate, iq, id, iq->qchase.qclass))
1075 return error_response(qstate, id,
1076 LDNS_RCODE_REFUSED);
1078 /* priming creates and sends a subordinate query, with
1079 * this query as the parent. So further processing for
1080 * this event will stop until reactivated by the
1081 * results of priming. */
1085 /* see if this dp not useless.
1087 * o all NS items are required glue.
1088 * or the query is for NS item that is required glue.
1089 * o no addresses are provided.
1091 * Instead, go up one level, and try to get even further
1092 * If the root was useless, use safety belt information.
1093 * Only check cache returns, because replies for servers
1094 * could be useless but lead to loops (bumping into the
1095 * same server reply) if useless-checked.
1097 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
1099 if(dname_is_root(iq->dp->name)) {
1100 /* use safety belt */
1101 verbose(VERB_QUERY, "Cache has root NS but "
1102 "no addresses. Fallback to the safety belt.");
1103 iq->dp = hints_lookup_root(qstate->env->hints,
1105 /* note deleg_msg is from previous lookup,
1106 * but RD is on, so it is not used */
1108 log_err("internal error: no hints dp");
1109 return error_response(qstate, id,
1110 LDNS_RCODE_REFUSED);
1112 iq->dp = delegpt_copy(iq->dp, qstate->region);
1114 log_err("out of memory in safety belt");
1115 return error_response(qstate, id,
1116 LDNS_RCODE_SERVFAIL);
1121 "cache delegation was useless:");
1122 delegpt_log(VERB_ALGO, iq->dp);
1124 delname = iq->dp->name;
1125 delnamelen = iq->dp->namelen;
1126 dname_remove_label(&delname, &delnamelen);
1131 verbose(VERB_ALGO, "cache delegation returns delegpt");
1132 delegpt_log(VERB_ALGO, iq->dp);
1134 /* Otherwise, set the current delegation point and move on to the
1136 return next_state(iq, INIT_REQUEST_2_STATE);
1140 * Process the second part of the initial request handling. This state
1141 * basically exists so that queries that generate root priming events have
1142 * the same init processing as ones that do not. Request events that reach
1143 * this state must have a valid currentDelegationPoint set.
1145 * This part is primarly handling stub zone priming. Events that reach this
1146 * state must have a current delegation point.
1148 * @param qstate: query state.
1149 * @param iq: iterator query state.
1150 * @param id: module id.
1151 * @return true if the event needs more request processing immediately,
1155 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
1160 log_query_info(VERB_QUERY, "resolving (init part 2): ",
1163 if(iq->refetch_glue) {
1165 log_err("internal or malloc fail: no dp for refetch");
1166 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1168 delname = iq->dp->name;
1169 delnamelen = iq->dp->namelen;
1171 delname = iq->qchase.qname;
1172 delnamelen = iq->qchase.qname_len;
1174 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
1175 if(!dname_is_root(delname))
1176 dname_remove_label(&delname, &delnamelen);
1177 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
1179 /* Check to see if we need to prime a stub zone. */
1180 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
1181 /* A priming sub request was made */
1185 /* most events just get forwarded to the next state. */
1186 return next_state(iq, INIT_REQUEST_3_STATE);
1190 * Process the third part of the initial request handling. This state exists
1191 * as a separate state so that queries that generate stub priming events
1192 * will get the tail end of the init process but not repeat the stub priming
1195 * @param qstate: query state.
1196 * @param iq: iterator query state.
1197 * @param id: module id.
1198 * @return true, advancing the event to the QUERYTARGETS_STATE.
1201 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
1204 log_query_info(VERB_QUERY, "resolving (init part 3): ",
1206 /* if the cache reply dp equals a validation anchor or msg has DS,
1207 * then DNSSEC RRSIGs are expected in the reply */
1208 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
1209 iq->deleg_msg, iq->qchase.qclass);
1211 /* If the RD flag wasn't set, then we just finish with the
1212 * cached referral as the response. */
1213 if(!(qstate->query_flags & BIT_RD)) {
1214 iq->response = iq->deleg_msg;
1215 if(verbosity >= VERB_ALGO)
1216 log_dns_msg("no RD requested, using delegation msg",
1217 &iq->response->qinfo, iq->response->rep);
1218 if(qstate->reply_origin)
1219 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1220 return final_state(iq);
1222 /* After this point, unset the RD flag -- this query is going to
1223 * be sent to an auth. server. */
1224 iq->chase_flags &= ~BIT_RD;
1226 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */
1227 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
1228 !(qstate->query_flags&BIT_CD)) {
1229 generate_dnskey_prefetch(qstate, iq, id);
1230 fptr_ok(fptr_whitelist_modenv_detach_subs(
1231 qstate->env->detach_subs));
1232 (*qstate->env->detach_subs)(qstate);
1235 /* Jump to the next state. */
1236 return next_state(iq, QUERYTARGETS_STATE);
1240 * Given a basic query, generate a parent-side "target" query.
1241 * These are subordinate queries for missing delegation point target addresses,
1242 * for which only the parent of the delegation provides correct IP addresses.
1244 * @param qstate: query state.
1245 * @param iq: iterator query state.
1246 * @param id: module id.
1247 * @param name: target qname.
1248 * @param namelen: target qname length.
1249 * @param qtype: target qtype (either A or AAAA).
1250 * @param qclass: target qclass.
1251 * @return true on success, false on failure.
1254 generate_parentside_target_query(struct module_qstate* qstate,
1255 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen,
1256 uint16_t qtype, uint16_t qclass)
1258 struct module_qstate* subq;
1259 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1260 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
1263 struct iter_qstate* subiq =
1264 (struct iter_qstate*)subq->minfo[id];
1265 /* blacklist the cache - we want to fetch parent stuff */
1266 sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
1267 subiq->query_for_pside_glue = 1;
1268 if(dname_subdomain_c(name, iq->dp->name)) {
1269 subiq->dp = delegpt_copy(iq->dp, subq->region);
1270 subiq->dnssec_expected = iter_indicates_dnssec(
1271 qstate->env, subiq->dp, NULL,
1272 subq->qinfo.qclass);
1273 subiq->refetch_glue = 1;
1275 subiq->dp = dns_cache_find_delegation(qstate->env,
1276 name, namelen, qtype, qclass, subq->region,
1278 *qstate->env->now+subq->prefetch_leeway);
1279 /* if no dp, then it's from root, refetch unneeded */
1281 subiq->dnssec_expected = iter_indicates_dnssec(
1282 qstate->env, subiq->dp, NULL,
1283 subq->qinfo.qclass);
1284 subiq->refetch_glue = 1;
1288 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
1293 * Given a basic query, generate a "target" query. These are subordinate
1294 * queries for missing delegation point target addresses.
1296 * @param qstate: query state.
1297 * @param iq: iterator query state.
1298 * @param id: module id.
1299 * @param name: target qname.
1300 * @param namelen: target qname length.
1301 * @param qtype: target qtype (either A or AAAA).
1302 * @param qclass: target qclass.
1303 * @return true on success, false on failure.
1306 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
1307 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
1309 struct module_qstate* subq;
1310 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1311 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0))
1313 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
1318 * Given an event at a certain state, generate zero or more target queries
1319 * for it's current delegation point.
1321 * @param qstate: query state.
1322 * @param iq: iterator query state.
1323 * @param ie: iterator shared global environment.
1324 * @param id: module id.
1325 * @param maxtargets: The maximum number of targets to query for.
1326 * if it is negative, there is no maximum number of targets.
1327 * @param num: returns the number of queries generated and processed,
1328 * which may be zero if there were no missing targets.
1329 * @return false on error.
1332 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
1333 struct iter_env* ie, int id, int maxtargets, int* num)
1335 int query_count = 0;
1336 struct delegpt_ns* ns;
1340 if(iq->depth == ie->max_dependency_depth)
1343 iter_mark_cycle_targets(qstate, iq->dp);
1344 missing = (int)delegpt_count_missing_targets(iq->dp);
1345 log_assert(maxtargets != 0); /* that would not be useful */
1347 /* Generate target requests. Basically, any missing targets
1348 * are queried for here, regardless if it is necessary to do
1349 * so to continue processing. */
1350 if(maxtargets < 0 || maxtargets > missing)
1352 else toget = maxtargets;
1357 /* select 'toget' items from the total of 'missing' items */
1358 log_assert(toget <= missing);
1360 /* loop over missing targets */
1361 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1365 /* randomly select this item with probability toget/missing */
1366 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
1367 /* do not select this one, next; select toget number
1368 * of items from a list one less in size */
1373 if(ie->supports_ipv6 && !ns->got6) {
1374 /* Send the AAAA request. */
1375 if(!generate_target_query(qstate, iq, id,
1376 ns->name, ns->namelen,
1377 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
1380 qstate->ext_state[id] = module_wait_subquery;
1385 /* Send the A request. */
1386 if(ie->supports_ipv4 && !ns->got4) {
1387 if(!generate_target_query(qstate, iq, id,
1388 ns->name, ns->namelen,
1389 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
1392 qstate->ext_state[id] = module_wait_subquery;
1398 /* mark this target as in progress. */
1407 qstate->ext_state[id] = module_wait_subquery;
1412 /** see if last resort is possible - does config allow queries to parent */
1414 can_have_last_resort(struct module_env* env, struct delegpt* dp,
1415 struct iter_qstate* iq)
1417 struct delegpt* fwddp;
1418 struct iter_hints_stub* stub;
1419 /* do not process a last resort (the parent side) if a stub
1420 * or forward is configured, because we do not want to go 'above'
1421 * the configured servers */
1422 if(!dname_is_root(dp->name) && (stub = (struct iter_hints_stub*)
1423 name_tree_find(&env->hints->tree, dp->name, dp->namelen,
1424 dp->namelabs, iq->qchase.qclass)) &&
1425 /* has_parent side is turned off for stub_first, where we
1426 * are allowed to go to the parent */
1427 stub->dp->has_parent_side_NS) {
1428 verbose(VERB_QUERY, "configured stub servers failed -- returning SERVFAIL");
1431 if((fwddp = forwards_find(env->fwds, dp->name, iq->qchase.qclass)) &&
1432 /* has_parent_side is turned off for forward_first, where
1433 * we are allowed to go to the parent */
1434 fwddp->has_parent_side_NS) {
1435 verbose(VERB_QUERY, "configured forward servers failed -- returning SERVFAIL");
1442 * Called by processQueryTargets when it would like extra targets to query
1443 * but it seems to be out of options. At last resort some less appealing
1444 * options are explored. If there are no more options, the result is SERVFAIL
1446 * @param qstate: query state.
1447 * @param iq: iterator query state.
1448 * @param ie: iterator shared global environment.
1449 * @param id: module id.
1450 * @return true if the event requires more request processing immediately,
1454 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
1455 struct iter_env* ie, int id)
1457 struct delegpt_ns* ns;
1458 int query_count = 0;
1459 verbose(VERB_ALGO, "No more query targets, attempting last resort");
1462 if(!can_have_last_resort(qstate->env, iq->dp, iq)) {
1463 /* fail -- no more targets, no more hope of targets, no hope
1465 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1467 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
1468 struct delegpt* p = hints_lookup_root(qstate->env->hints,
1471 struct delegpt_ns* ns;
1472 struct delegpt_addr* a;
1473 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1474 for(ns = p->nslist; ns; ns=ns->next) {
1475 (void)delegpt_add_ns(iq->dp, qstate->region,
1476 ns->name, ns->lame);
1478 for(a = p->target_list; a; a=a->next_target) {
1479 (void)delegpt_add_addr(iq->dp, qstate->region,
1480 &a->addr, a->addrlen, a->bogus,
1484 iq->dp->has_parent_side_NS = 1;
1485 } else if(!iq->dp->has_parent_side_NS) {
1486 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
1487 qstate->region, &qstate->qinfo)
1488 || !iq->dp->has_parent_side_NS) {
1489 /* if: malloc failure in lookup go up to try */
1490 /* if: no parent NS in cache - go up one level */
1491 verbose(VERB_ALGO, "try to grab parent NS");
1492 iq->store_parent_NS = iq->dp;
1493 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1494 iq->deleg_msg = NULL;
1495 iq->refetch_glue = 1;
1496 iq->query_restart_count++;
1498 return next_state(iq, INIT_REQUEST_STATE);
1501 /* see if that makes new names available */
1502 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
1503 qstate->region, iq->dp))
1504 log_err("out of memory in cache_fill_missing");
1505 if(iq->dp->usable_list) {
1506 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
1507 return next_state(iq, QUERYTARGETS_STATE);
1509 /* try to fill out parent glue from cache */
1510 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
1511 qstate->region, &qstate->qinfo)) {
1512 /* got parent stuff from cache, see if we can continue */
1513 verbose(VERB_ALGO, "try parent-side glue from cache");
1514 return next_state(iq, QUERYTARGETS_STATE);
1516 /* query for an extra name added by the parent-NS record */
1517 if(delegpt_count_missing_targets(iq->dp) > 0) {
1519 verbose(VERB_ALGO, "try parent-side target name");
1520 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
1521 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1523 iq->num_target_queries += qs;
1525 qstate->ext_state[id] = module_wait_subquery;
1526 return 0; /* and wait for them */
1529 if(iq->depth == ie->max_dependency_depth) {
1530 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
1531 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1533 /* mark cycle targets for parent-side lookups */
1534 iter_mark_pside_cycle_targets(qstate, iq->dp);
1535 /* see if we can issue queries to get nameserver addresses */
1536 /* this lookup is not randomized, but sequential. */
1537 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1538 /* query for parent-side A and AAAA for nameservers */
1539 if(ie->supports_ipv6 && !ns->done_pside6) {
1540 /* Send the AAAA request. */
1541 if(!generate_parentside_target_query(qstate, iq, id,
1542 ns->name, ns->namelen,
1543 LDNS_RR_TYPE_AAAA, iq->qchase.qclass))
1544 return error_response(qstate, id,
1545 LDNS_RCODE_SERVFAIL);
1546 ns->done_pside6 = 1;
1549 if(ie->supports_ipv4 && !ns->done_pside4) {
1550 /* Send the A request. */
1551 if(!generate_parentside_target_query(qstate, iq, id,
1552 ns->name, ns->namelen,
1553 LDNS_RR_TYPE_A, iq->qchase.qclass))
1554 return error_response(qstate, id,
1555 LDNS_RCODE_SERVFAIL);
1556 ns->done_pside4 = 1;
1559 if(query_count != 0) { /* suspend to await results */
1560 verbose(VERB_ALGO, "try parent-side glue lookup");
1561 iq->num_target_queries += query_count;
1562 qstate->ext_state[id] = module_wait_subquery;
1567 /* if this was a parent-side glue query itself, then store that
1568 * failure in cache. */
1569 if(iq->query_for_pside_glue && !iq->pside_glue)
1570 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
1571 iq->deleg_msg?iq->deleg_msg->rep:
1572 (iq->response?iq->response->rep:NULL));
1574 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
1575 /* fail -- no more targets, no more hope of targets, no hope
1577 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1581 * Try to find the NS record set that will resolve a qtype DS query. Due
1582 * to grandparent/grandchild reasons we did not get a proper lookup right
1583 * away. We need to create type NS queries until we get the right parent
1584 * for this lookup. We remove labels from the query to find the right point.
1585 * If we end up at the old dp name, then there is no solution.
1587 * @param qstate: query state.
1588 * @param iq: iterator query state.
1589 * @param id: module id.
1590 * @return true if the event requires more immediate processing, false if
1591 * not. This is generally only true when forwarding the request to
1592 * the final state (i.e., on answer).
1595 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
1597 struct module_qstate* subq = NULL;
1598 verbose(VERB_ALGO, "processDSNSFind");
1600 if(!iq->dsns_point) {
1602 iq->dsns_point = iq->qchase.qname;
1603 iq->dsns_point_len = iq->qchase.qname_len;
1605 /* robustcheck for internal error: we are not underneath the dp */
1606 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
1607 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1610 /* go up one (more) step, until we hit the dp, if so, end */
1611 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
1612 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
1613 /* there was no inbetween nameserver, use the old delegation
1614 * point again. And this time, because dsns_point is nonNULL
1615 * we are going to accept the (bad) result */
1616 iq->state = QUERYTARGETS_STATE;
1619 iq->state = DSNS_FIND_STATE;
1621 /* spawn NS lookup (validation not needed, this is for DS lookup) */
1622 log_nametypeclass(VERB_ALGO, "fetch nameservers",
1623 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
1624 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
1625 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
1626 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
1627 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1634 * This is the request event state where the request will be sent to one of
1635 * its current query targets. This state also handles issuing target lookup
1636 * queries for missing target IP addresses. Queries typically iterate on
1637 * this state, both when they are just trying different targets for a given
1638 * delegation point, and when they change delegation points. This state
1639 * roughly corresponds to RFC 1034 algorithm steps 3 and 4.
1641 * @param qstate: query state.
1642 * @param iq: iterator query state.
1643 * @param ie: iterator shared global environment.
1644 * @param id: module id.
1645 * @return true if the event requires more request processing immediately,
1646 * false if not. This state only returns true when it is generating
1647 * a SERVFAIL response because the query has hit a dead end.
1650 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
1651 struct iter_env* ie, int id)
1654 struct delegpt_addr* target;
1655 struct outbound_entry* outq;
1657 /* NOTE: a request will encounter this state for each target it
1658 * needs to send a query to. That is, at least one per referral,
1659 * more if some targets timeout or return throwaway answers. */
1661 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
1662 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
1663 "currentqueries %d sentcount %d", iq->num_target_queries,
1664 iq->num_current_queries, iq->sent_count);
1666 /* Make sure that we haven't run away */
1667 /* FIXME: is this check even necessary? */
1668 if(iq->referral_count > MAX_REFERRAL_COUNT) {
1669 verbose(VERB_QUERY, "request has exceeded the maximum "
1670 "number of referrrals with %d", iq->referral_count);
1671 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1673 if(iq->sent_count > MAX_SENT_COUNT) {
1674 verbose(VERB_QUERY, "request has exceeded the maximum "
1675 "number of sends with %d", iq->sent_count);
1676 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1679 /* Make sure we have a delegation point, otherwise priming failed
1680 * or another failure occurred */
1682 verbose(VERB_QUERY, "Failed to get a delegation, giving up");
1683 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1685 if(!ie->supports_ipv6)
1686 delegpt_no_ipv6(iq->dp);
1687 if(!ie->supports_ipv4)
1688 delegpt_no_ipv4(iq->dp);
1689 delegpt_log(VERB_ALGO, iq->dp);
1691 if(iq->num_current_queries>0) {
1692 /* already busy answering a query, this restart is because
1693 * more delegpt addrs became available, wait for existing
1695 verbose(VERB_ALGO, "woke up, but wait for outstanding query");
1696 qstate->ext_state[id] = module_wait_reply;
1701 /* < not <=, because although the array is large enough for <=, the
1702 * generated query will immediately be discarded due to depth and
1703 * that servfail is cached, which is not good as opportunism goes. */
1704 if(iq->depth < ie->max_dependency_depth
1705 && iq->sent_count < TARGET_FETCH_STOP) {
1706 tf_policy = ie->target_fetch_policy[iq->depth];
1709 /* if in 0x20 fallback get as many targets as possible */
1710 if(iq->caps_fallback) {
1712 size_t naddr, nres, navail;
1713 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
1714 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1716 iq->num_target_queries += extra;
1717 if(iq->num_target_queries > 0) {
1718 /* wait to get all targets, we want to try em */
1719 verbose(VERB_ALGO, "wait for all targets for fallback");
1720 qstate->ext_state[id] = module_wait_reply;
1723 /* did we do enough fallback queries already? */
1724 delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
1725 /* the current caps_server is the number of fallbacks sent.
1726 * the original query is one that matched too, so we have
1727 * caps_server+1 number of matching queries now */
1728 if(iq->caps_server+1 >= naddr*3 ||
1729 iq->caps_server+1 >= MAX_SENT_COUNT) {
1730 /* we're done, process the response */
1731 verbose(VERB_ALGO, "0x20 fallback had %d responses "
1732 "match for %d wanted, done.",
1733 (int)iq->caps_server+1, (int)naddr*3);
1734 iq->caps_fallback = 0;
1735 iter_dec_attempts(iq->dp, 3); /* space for fallback */
1736 iq->num_current_queries++; /* RespState decrements it*/
1737 iq->referral_count++; /* make sure we don't loop */
1739 iq->state = QUERY_RESP_STATE;
1742 verbose(VERB_ALGO, "0x20 fallback number %d",
1743 (int)iq->caps_server);
1745 /* if there is a policy to fetch missing targets
1746 * opportunistically, do it. we rely on the fact that once a
1747 * query (or queries) for a missing name have been issued,
1748 * they will not show up again. */
1749 } else if(tf_policy != 0) {
1751 verbose(VERB_ALGO, "attempt to get extra %d targets",
1753 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
1754 /* errors ignored, these targets are not strictly necessary for
1755 * this result, we do not have to reply with SERVFAIL */
1756 iq->num_target_queries += extra;
1759 /* Add the current set of unused targets to our queue. */
1760 delegpt_add_unused_targets(iq->dp);
1762 /* Select the next usable target, filtering out unsuitable targets. */
1763 target = iter_server_selection(ie, qstate->env, iq->dp,
1764 iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
1765 &iq->dnssec_lame_query, &iq->chase_to_rd,
1766 iq->num_target_queries, qstate->blacklist);
1768 /* If no usable target was selected... */
1770 /* Here we distinguish between three states: generate a new
1771 * target query, just wait, or quit (with a SERVFAIL).
1772 * We have the following information: number of active
1773 * target queries, number of active current queries,
1774 * the presence of missing targets at this delegation
1775 * point, and the given query target policy. */
1777 /* Check for the wait condition. If this is true, then
1778 * an action must be taken. */
1779 if(iq->num_target_queries==0 && iq->num_current_queries==0) {
1780 /* If there is nothing to wait for, then we need
1781 * to distinguish between generating (a) new target
1782 * query, or failing. */
1783 if(delegpt_count_missing_targets(iq->dp) > 0) {
1785 verbose(VERB_ALGO, "querying for next "
1787 if(!query_for_targets(qstate, iq, ie, id,
1789 return error_response(qstate, id,
1790 LDNS_RCODE_SERVFAIL);
1793 delegpt_count_missing_targets(iq->dp) == 0){
1794 /* it looked like there were missing
1795 * targets, but they did not turn up.
1796 * Try the bad choices again (if any),
1797 * when we get back here missing==0,
1798 * so this is not a loop. */
1801 iq->num_target_queries += qs;
1803 /* Since a target query might have been made, we
1804 * need to check again. */
1805 if(iq->num_target_queries == 0) {
1806 return processLastResort(qstate, iq, ie, id);
1810 /* otherwise, we have no current targets, so submerge
1811 * until one of the target or direct queries return. */
1812 if(iq->num_target_queries>0 && iq->num_current_queries>0) {
1813 verbose(VERB_ALGO, "no current targets -- waiting "
1814 "for %d targets to resolve or %d outstanding"
1815 " queries to respond", iq->num_target_queries,
1816 iq->num_current_queries);
1817 qstate->ext_state[id] = module_wait_reply;
1818 } else if(iq->num_target_queries>0) {
1819 verbose(VERB_ALGO, "no current targets -- waiting "
1820 "for %d targets to resolve.",
1821 iq->num_target_queries);
1822 qstate->ext_state[id] = module_wait_subquery;
1824 verbose(VERB_ALGO, "no current targets -- waiting "
1825 "for %d outstanding queries to respond.",
1826 iq->num_current_queries);
1827 qstate->ext_state[id] = module_wait_reply;
1832 /* We have a valid target. */
1833 if(verbosity >= VERB_QUERY) {
1834 log_query_info(VERB_QUERY, "sending query:", &iq->qchase);
1835 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
1836 &target->addr, target->addrlen);
1837 verbose(VERB_ALGO, "dnssec status: %s%s",
1838 iq->dnssec_expected?"expected": "not expected",
1839 iq->dnssec_lame_query?" but lame_query anyway": "");
1841 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
1842 outq = (*qstate->env->send_query)(
1843 iq->qchase.qname, iq->qchase.qname_len,
1844 iq->qchase.qtype, iq->qchase.qclass,
1845 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0), EDNS_DO|BIT_CD,
1846 iq->dnssec_expected, &target->addr, target->addrlen,
1847 iq->dp->name, iq->dp->namelen, qstate);
1849 log_addr(VERB_DETAIL, "error sending query to auth server",
1850 &target->addr, target->addrlen);
1851 return next_state(iq, QUERYTARGETS_STATE);
1853 outbound_list_insert(&iq->outlist, outq);
1854 iq->num_current_queries++;
1856 qstate->ext_state[id] = module_wait_reply;
1861 /** find NS rrset in given list */
1862 static struct ub_packed_rrset_key*
1863 find_NS(struct reply_info* rep, size_t from, size_t to)
1866 for(i=from; i<to; i++) {
1867 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
1868 return rep->rrsets[i];
1875 * Process the query response. All queries end up at this state first. This
1876 * process generally consists of analyzing the response and routing the
1877 * event to the next state (either bouncing it back to a request state, or
1878 * terminating the processing for this event).
1880 * @param qstate: query state.
1881 * @param iq: iterator query state.
1882 * @param id: module id.
1883 * @return true if the event requires more immediate processing, false if
1884 * not. This is generally only true when forwarding the request to
1885 * the final state (i.e., on answer).
1888 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
1892 enum response_type type;
1893 iq->num_current_queries--;
1894 if(iq->response == NULL) {
1895 iq->chase_to_rd = 0;
1896 iq->dnssec_lame_query = 0;
1897 verbose(VERB_ALGO, "query response was timeout");
1898 return next_state(iq, QUERYTARGETS_STATE);
1900 type = response_type_from_server(
1901 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
1902 iq->response, &iq->qchase, iq->dp);
1903 iq->chase_to_rd = 0;
1904 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD)) {
1905 /* When forwarding (RD bit is set), we handle referrals
1906 * differently. No queries should be sent elsewhere */
1907 type = RESPONSE_TYPE_ANSWER;
1909 if(iq->dnssec_expected && !iq->dnssec_lame_query &&
1910 !(iq->chase_flags&BIT_RD)
1911 && type != RESPONSE_TYPE_LAME
1912 && type != RESPONSE_TYPE_REC_LAME
1913 && type != RESPONSE_TYPE_THROWAWAY
1914 && type != RESPONSE_TYPE_UNTYPED) {
1915 /* a possible answer, see if it is missing DNSSEC */
1916 /* but not when forwarding, so we dont mark fwder lame */
1917 if(!iter_msg_has_dnssec(iq->response)) {
1918 /* Mark this address as dnsseclame in this dp,
1919 * because that will make serverselection disprefer
1920 * it, but also, once it is the only final option,
1921 * use dnssec-lame-bypass if it needs to query there.*/
1923 struct delegpt_addr* a = delegpt_find_addr(
1924 iq->dp, &qstate->reply->addr,
1925 qstate->reply->addrlen);
1926 if(a) a->dnsseclame = 1;
1928 /* test the answer is from the zone we expected,
1929 * otherwise, (due to parent,child on same server), we
1930 * might mark the server,zone lame inappropriately */
1931 if(!iter_msg_from_zone(iq->response, iq->dp, type,
1933 qstate->reply = NULL;
1934 type = RESPONSE_TYPE_LAME;
1937 } else iq->dnssec_lame_query = 0;
1938 /* see if referral brings us close to the target */
1939 if(type == RESPONSE_TYPE_REFERRAL) {
1940 struct ub_packed_rrset_key* ns = find_NS(
1941 iq->response->rep, iq->response->rep->an_numrrsets,
1942 iq->response->rep->an_numrrsets
1943 + iq->response->rep->ns_numrrsets);
1944 if(!ns) ns = find_NS(iq->response->rep, 0,
1945 iq->response->rep->an_numrrsets);
1946 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
1947 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
1948 verbose(VERB_ALGO, "bad referral, throwaway");
1949 type = RESPONSE_TYPE_THROWAWAY;
1951 iter_scrub_ds(iq->response, ns, iq->dp->name);
1952 } else iter_scrub_ds(iq->response, NULL, NULL);
1954 /* handle each of the type cases */
1955 if(type == RESPONSE_TYPE_ANSWER) {
1956 /* ANSWER type responses terminate the query algorithm,
1957 * so they sent on their */
1958 if(verbosity >= VERB_DETAIL) {
1959 verbose(VERB_DETAIL, "query response was %s",
1960 FLAGS_GET_RCODE(iq->response->rep->flags)
1961 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
1962 (iq->response->rep->an_numrrsets?"ANSWER":
1965 /* if qtype is DS, check we have the right level of answer,
1966 * like grandchild answer but we need the middle, reject it */
1967 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
1968 && !(iq->chase_flags&BIT_RD)
1969 && iter_ds_toolow(iq->response, iq->dp)
1970 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
1971 /* close down outstanding requests to be discarded */
1972 outbound_list_clear(&iq->outlist);
1973 iq->num_current_queries = 0;
1974 fptr_ok(fptr_whitelist_modenv_detach_subs(
1975 qstate->env->detach_subs));
1976 (*qstate->env->detach_subs)(qstate);
1977 iq->num_target_queries = 0;
1978 return processDSNSFind(qstate, iq, id);
1980 iter_dns_store(qstate->env, &iq->response->qinfo,
1981 iq->response->rep, 0, qstate->prefetch_leeway,
1982 iq->dp&&iq->dp->has_parent_side_NS,
1984 /* close down outstanding requests to be discarded */
1985 outbound_list_clear(&iq->outlist);
1986 iq->num_current_queries = 0;
1987 fptr_ok(fptr_whitelist_modenv_detach_subs(
1988 qstate->env->detach_subs));
1989 (*qstate->env->detach_subs)(qstate);
1990 iq->num_target_queries = 0;
1992 sock_list_insert(&qstate->reply_origin,
1993 &qstate->reply->addr, qstate->reply->addrlen,
1995 return final_state(iq);
1996 } else if(type == RESPONSE_TYPE_REFERRAL) {
1997 /* REFERRAL type responses get a reset of the
1998 * delegation point, and back to the QUERYTARGETS_STATE. */
1999 verbose(VERB_DETAIL, "query response was REFERRAL");
2001 /* if hardened, only store referral if we asked for it */
2002 if(!qstate->env->cfg->harden_referral_path ||
2003 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
2004 && (qstate->query_flags&BIT_RD)
2005 && !(qstate->query_flags&BIT_CD)
2006 /* we know that all other NS rrsets are scrubbed
2007 * away, thus on referral only one is left.
2008 * see if that equals the query name... */
2009 && ( /* auth section, but sometimes in answer section*/
2010 reply_find_rrset_section_ns(iq->response->rep,
2011 iq->qchase.qname, iq->qchase.qname_len,
2012 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2013 || reply_find_rrset_section_an(iq->response->rep,
2014 iq->qchase.qname, iq->qchase.qname_len,
2015 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2018 /* Store the referral under the current query */
2019 /* no prefetch-leeway, since its not the answer */
2020 iter_dns_store(qstate->env, &iq->response->qinfo,
2021 iq->response->rep, 1, 0, 0, NULL);
2022 if(iq->store_parent_NS)
2023 iter_store_parentside_NS(qstate->env,
2025 if(qstate->env->neg_cache)
2026 val_neg_addreferral(qstate->env->neg_cache,
2027 iq->response->rep, iq->dp->name);
2029 /* store parent-side-in-zone-glue, if directly queried for */
2030 if(iq->query_for_pside_glue && !iq->pside_glue) {
2031 iq->pside_glue = reply_find_rrset(iq->response->rep,
2032 iq->qchase.qname, iq->qchase.qname_len,
2033 iq->qchase.qtype, iq->qchase.qclass);
2034 if(iq->pside_glue) {
2035 log_rrset_key(VERB_ALGO, "found parent-side "
2036 "glue", iq->pside_glue);
2037 iter_store_parentside_rrset(qstate->env,
2042 /* Reset the event state, setting the current delegation
2043 * point to the referral. */
2044 iq->deleg_msg = iq->response;
2045 iq->dp = delegpt_from_message(iq->response, qstate->region);
2047 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2048 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
2049 qstate->region, iq->dp))
2050 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2051 if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
2052 iq->store_parent_NS->name) == 0)
2053 iter_merge_retry_counts(iq->dp, iq->store_parent_NS);
2054 delegpt_log(VERB_ALGO, iq->dp);
2055 /* Count this as a referral. */
2056 iq->referral_count++;
2058 /* see if the next dp is a trust anchor, or a DS was sent
2059 * along, indicating dnssec is expected for next zone */
2060 iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
2061 iq->dp, iq->response, iq->qchase.qclass);
2062 /* if dnssec, validating then also fetch the key for the DS */
2063 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
2064 !(qstate->query_flags&BIT_CD))
2065 generate_dnskey_prefetch(qstate, iq, id);
2067 /* spawn off NS and addr to auth servers for the NS we just
2068 * got in the referral. This gets authoritative answer
2069 * (answer section trust level) rrset.
2070 * right after, we detach the subs, answer goes to cache. */
2071 if(qstate->env->cfg->harden_referral_path)
2072 generate_ns_check(qstate, iq, id);
2074 /* stop current outstanding queries.
2075 * FIXME: should the outstanding queries be waited for and
2076 * handled? Say by a subquery that inherits the outbound_entry.
2078 outbound_list_clear(&iq->outlist);
2079 iq->num_current_queries = 0;
2080 fptr_ok(fptr_whitelist_modenv_detach_subs(
2081 qstate->env->detach_subs));
2082 (*qstate->env->detach_subs)(qstate);
2083 iq->num_target_queries = 0;
2084 verbose(VERB_ALGO, "cleared outbound list for next round");
2085 return next_state(iq, QUERYTARGETS_STATE);
2086 } else if(type == RESPONSE_TYPE_CNAME) {
2087 uint8_t* sname = NULL;
2088 size_t snamelen = 0;
2089 /* CNAME type responses get a query restart (i.e., get a
2090 * reset of the query state and go back to INIT_REQUEST_STATE).
2092 verbose(VERB_DETAIL, "query response was CNAME");
2093 if(verbosity >= VERB_ALGO)
2094 log_dns_msg("cname msg", &iq->response->qinfo,
2096 /* if qtype is DS, check we have the right level of answer,
2097 * like grandchild answer but we need the middle, reject it */
2098 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
2099 && !(iq->chase_flags&BIT_RD)
2100 && iter_ds_toolow(iq->response, iq->dp)
2101 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
2102 outbound_list_clear(&iq->outlist);
2103 iq->num_current_queries = 0;
2104 fptr_ok(fptr_whitelist_modenv_detach_subs(
2105 qstate->env->detach_subs));
2106 (*qstate->env->detach_subs)(qstate);
2107 iq->num_target_queries = 0;
2108 return processDSNSFind(qstate, iq, id);
2110 /* Process the CNAME response. */
2111 if(!handle_cname_response(qstate, iq, iq->response,
2113 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2114 /* cache the CNAME response under the current query */
2115 /* NOTE : set referral=1, so that rrsets get stored but not
2116 * the partial query answer (CNAME only). */
2117 /* prefetchleeway applied because this updates answer parts */
2118 iter_dns_store(qstate->env, &iq->response->qinfo,
2119 iq->response->rep, 1, qstate->prefetch_leeway,
2120 iq->dp&&iq->dp->has_parent_side_NS, NULL);
2121 /* set the current request's qname to the new value. */
2122 iq->qchase.qname = sname;
2123 iq->qchase.qname_len = snamelen;
2124 /* Clear the query state, since this is a query restart. */
2125 iq->deleg_msg = NULL;
2127 iq->dsns_point = NULL;
2128 /* Note the query restart. */
2129 iq->query_restart_count++;
2132 /* stop current outstanding queries.
2133 * FIXME: should the outstanding queries be waited for and
2134 * handled? Say by a subquery that inherits the outbound_entry.
2136 outbound_list_clear(&iq->outlist);
2137 iq->num_current_queries = 0;
2138 fptr_ok(fptr_whitelist_modenv_detach_subs(
2139 qstate->env->detach_subs));
2140 (*qstate->env->detach_subs)(qstate);
2141 iq->num_target_queries = 0;
2143 sock_list_insert(&qstate->reply_origin,
2144 &qstate->reply->addr, qstate->reply->addrlen,
2146 verbose(VERB_ALGO, "cleared outbound list for query restart");
2147 /* go to INIT_REQUEST_STATE for new qname. */
2148 return next_state(iq, INIT_REQUEST_STATE);
2149 } else if(type == RESPONSE_TYPE_LAME) {
2150 /* Cache the LAMEness. */
2151 verbose(VERB_DETAIL, "query response was %sLAME",
2152 dnsseclame?"DNSSEC ":"");
2153 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
2154 log_err("mark lame: mismatch in qname and dpname");
2155 /* throwaway this reply below */
2156 } else if(qstate->reply) {
2157 /* need addr for lameness cache, but we may have
2158 * gotten this from cache, so test to be sure */
2159 if(!infra_set_lame(qstate->env->infra_cache,
2160 &qstate->reply->addr, qstate->reply->addrlen,
2161 iq->dp->name, iq->dp->namelen,
2162 *qstate->env->now, dnsseclame, 0,
2164 log_err("mark host lame: out of memory");
2166 } else if(type == RESPONSE_TYPE_REC_LAME) {
2167 /* Cache the LAMEness. */
2168 verbose(VERB_DETAIL, "query response REC_LAME: "
2169 "recursive but not authoritative server");
2170 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
2171 log_err("mark rec_lame: mismatch in qname and dpname");
2172 /* throwaway this reply below */
2173 } else if(qstate->reply) {
2174 /* need addr for lameness cache, but we may have
2175 * gotten this from cache, so test to be sure */
2176 verbose(VERB_DETAIL, "mark as REC_LAME");
2177 if(!infra_set_lame(qstate->env->infra_cache,
2178 &qstate->reply->addr, qstate->reply->addrlen,
2179 iq->dp->name, iq->dp->namelen,
2180 *qstate->env->now, 0, 1, iq->qchase.qtype))
2181 log_err("mark host lame: out of memory");
2183 } else if(type == RESPONSE_TYPE_THROWAWAY) {
2184 /* LAME and THROWAWAY responses are handled the same way.
2185 * In this case, the event is just sent directly back to
2186 * the QUERYTARGETS_STATE without resetting anything,
2187 * because, clearly, the next target must be tried. */
2188 verbose(VERB_DETAIL, "query response was THROWAWAY");
2190 log_warn("A query response came back with an unknown type: %d",
2194 /* LAME, THROWAWAY and "unknown" all end up here.
2195 * Recycle to the QUERYTARGETS state to hopefully try a
2196 * different target. */
2197 return next_state(iq, QUERYTARGETS_STATE);
2201 * Return priming query results to interestes super querystates.
2203 * Sets the delegation point and delegation message (not nonRD queries).
2204 * This is a callback from walk_supers.
2206 * @param qstate: priming query state that finished.
2207 * @param id: module id.
2208 * @param forq: the qstate for which priming has been done.
2211 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
2213 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2214 struct delegpt* dp = NULL;
2216 log_assert(qstate->is_priming || foriq->wait_priming_stub);
2217 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
2218 /* Convert our response to a delegation point */
2219 dp = delegpt_from_message(qstate->return_msg, forq->region);
2221 /* if there is no convertable delegation point, then
2222 * the ANSWER type was (presumably) a negative answer. */
2223 verbose(VERB_ALGO, "prime response was not a positive "
2226 foriq->state = QUERYTARGETS_STATE;
2230 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
2231 delegpt_log(VERB_ALGO, dp);
2233 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
2234 if(!foriq->deleg_msg) {
2235 log_err("copy prime response: out of memory");
2237 foriq->state = QUERYTARGETS_STATE;
2241 /* root priming responses go to init stage 2, priming stub
2242 * responses to to stage 3. */
2243 if(foriq->wait_priming_stub) {
2244 foriq->state = INIT_REQUEST_3_STATE;
2245 foriq->wait_priming_stub = 0;
2246 } else foriq->state = INIT_REQUEST_2_STATE;
2247 /* because we are finished, the parent will be reactivated */
2251 * This handles the response to a priming query. This is used to handle both
2252 * root and stub priming responses. This is basically the equivalent of the
2253 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat
2254 * REFERRALs as ANSWERS. It will also update and reactivate the originating
2257 * @param qstate: query state.
2258 * @param id: module id.
2259 * @return true if the event needs more immediate processing, false if not.
2260 * This state always returns false.
2263 processPrimeResponse(struct module_qstate* qstate, int id)
2265 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2266 enum response_type type;
2267 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
2268 type = response_type_from_server(
2269 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
2270 iq->response, &iq->qchase, iq->dp);
2271 if(type == RESPONSE_TYPE_ANSWER) {
2272 qstate->return_rcode = LDNS_RCODE_NOERROR;
2273 qstate->return_msg = iq->response;
2275 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
2276 qstate->return_msg = NULL;
2279 /* validate the root or stub after priming (if enabled).
2280 * This is the same query as the prime query, but with validation.
2281 * Now that we are primed, the additional queries that validation
2282 * may need can be resolved, such as DLV. */
2283 if(qstate->env->cfg->harden_referral_path) {
2284 struct module_qstate* subq = NULL;
2285 log_nametypeclass(VERB_ALGO, "schedule prime validation",
2286 qstate->qinfo.qname, qstate->qinfo.qtype,
2287 qstate->qinfo.qclass);
2288 if(!generate_sub_request(qstate->qinfo.qname,
2289 qstate->qinfo.qname_len, qstate->qinfo.qtype,
2290 qstate->qinfo.qclass, qstate, id, iq,
2291 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) {
2292 verbose(VERB_ALGO, "could not generate prime check");
2294 generate_a_aaaa_check(qstate, iq, id);
2297 /* This event is finished. */
2298 qstate->ext_state[id] = module_finished;
2303 * Do final processing on responses to target queries. Events reach this
2304 * state after the iterative resolution algorithm terminates. This state is
2305 * responsible for reactiving the original event, and housekeeping related
2306 * to received target responses (caching, updating the current delegation
2308 * Callback from walk_supers for every super state that is interested in
2309 * the results from this query.
2311 * @param qstate: query state.
2312 * @param id: module id.
2313 * @param forq: super query state.
2316 processTargetResponse(struct module_qstate* qstate, int id,
2317 struct module_qstate* forq)
2319 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2320 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2321 struct ub_packed_rrset_key* rrset;
2322 struct delegpt_ns* dpns;
2323 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
2325 foriq->state = QUERYTARGETS_STATE;
2326 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
2327 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
2329 /* check to see if parent event is still interested (in orig name). */
2331 verbose(VERB_ALGO, "subq: parent not interested, was reset");
2332 return; /* not interested anymore */
2334 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
2335 qstate->qinfo.qname_len);
2337 /* If not interested, just stop processing this event */
2338 verbose(VERB_ALGO, "subq: parent not interested anymore");
2339 /* could be because parent was jostled out of the cache,
2340 and a new identical query arrived, that does not want it*/
2344 /* Tell the originating event that this target query has finished
2345 * (regardless if it succeeded or not). */
2346 foriq->num_target_queries--;
2348 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
2349 if(iq->pside_glue) {
2350 /* if the pside_glue is NULL, then it could not be found,
2351 * the done_pside is already set when created and a cache
2352 * entry created in processFinished so nothing to do here */
2353 log_rrset_key(VERB_ALGO, "add parentside glue to dp",
2355 if(!delegpt_add_rrset(foriq->dp, forq->region,
2357 log_err("out of memory adding pside glue");
2360 /* This response is relevant to the current query, so we
2361 * add (attempt to add, anyway) this target(s) and reactivate
2362 * the original event.
2363 * NOTE: we could only look for the AnswerRRset if the
2364 * response type was ANSWER. */
2365 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
2367 /* if CNAMEs have been followed - add new NS to delegpt. */
2368 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
2369 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
2370 rrset->rk.dname_len)) {
2371 /* if dpns->lame then set newcname ns lame too */
2372 if(!delegpt_add_ns(foriq->dp, forq->region,
2373 rrset->rk.dname, dpns->lame))
2374 log_err("out of memory adding cnamed-ns");
2376 /* if dpns->lame then set the address(es) lame too */
2377 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
2379 log_err("out of memory adding targets");
2380 verbose(VERB_ALGO, "added target response");
2381 delegpt_log(VERB_ALGO, foriq->dp);
2383 verbose(VERB_ALGO, "iterator TargetResponse failed");
2384 dpns->resolved = 1; /* fail the target */
2389 * Process response for DS NS Find queries, that attempt to find the delegation
2390 * point where we ask the DS query from.
2392 * @param qstate: query state.
2393 * @param id: module id.
2394 * @param forq: super query state.
2397 processDSNSResponse(struct module_qstate* qstate, int id,
2398 struct module_qstate* forq)
2400 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2402 /* if the finished (iq->response) query has no NS set: continue
2403 * up to look for the right dp; nothing to change, do DPNSstate */
2404 if(qstate->return_rcode != LDNS_RCODE_NOERROR)
2405 return; /* seek further */
2406 /* find the NS RRset (without allowing CNAMEs) */
2407 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
2408 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
2409 qstate->qinfo.qclass)){
2410 return; /* seek further */
2413 /* else, store as DP and continue at querytargets */
2414 foriq->state = QUERYTARGETS_STATE;
2415 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
2417 log_err("out of memory in dsns dp alloc");
2418 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
2420 /* success, go query the querytargets in the new dp (and go down) */
2424 * Process response for qclass=ANY queries for a particular class.
2425 * Append to result or error-exit.
2427 * @param qstate: query state.
2428 * @param id: module id.
2429 * @param forq: super query state.
2432 processClassResponse(struct module_qstate* qstate, int id,
2433 struct module_qstate* forq)
2435 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
2436 struct dns_msg* from = qstate->return_msg;
2437 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
2438 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
2439 if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
2440 /* cause servfail for qclass ANY query */
2441 foriq->response = NULL;
2442 foriq->state = FINISHED_STATE;
2446 if(!foriq->response) {
2447 /* allocate the response: copy RCODE, sec_state */
2448 foriq->response = dns_copy_msg(from, forq->region);
2449 if(!foriq->response) {
2450 log_err("malloc failed for qclass ANY response");
2451 foriq->state = FINISHED_STATE;
2454 foriq->response->qinfo.qclass = forq->qinfo.qclass;
2455 /* qclass ANY does not receive the AA flag on replies */
2456 foriq->response->rep->authoritative = 0;
2458 struct dns_msg* to = foriq->response;
2459 /* add _from_ this response _to_ existing collection */
2460 /* if there are records, copy RCODE */
2461 /* lower sec_state if this message is lower */
2462 if(from->rep->rrset_count != 0) {
2463 size_t n = from->rep->rrset_count+to->rep->rrset_count;
2464 struct ub_packed_rrset_key** dest, **d;
2465 /* copy appropriate rcode */
2466 to->rep->flags = from->rep->flags;
2468 dest = regional_alloc(forq->region, sizeof(dest[0])*n);
2470 log_err("malloc failed in collect ANY");
2471 foriq->state = FINISHED_STATE;
2476 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
2478 dest += to->rep->an_numrrsets;
2479 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
2481 dest += from->rep->an_numrrsets;
2483 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
2484 to->rep->ns_numrrsets * sizeof(dest[0]));
2485 dest += to->rep->ns_numrrsets;
2486 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
2487 from->rep->ns_numrrsets * sizeof(dest[0]));
2488 dest += from->rep->ns_numrrsets;
2490 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
2491 to->rep->ns_numrrsets,
2492 to->rep->ar_numrrsets * sizeof(dest[0]));
2493 dest += to->rep->ar_numrrsets;
2494 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
2495 from->rep->ns_numrrsets,
2496 from->rep->ar_numrrsets * sizeof(dest[0]));
2498 to->rep->rrsets = d;
2499 to->rep->an_numrrsets += from->rep->an_numrrsets;
2500 to->rep->ns_numrrsets += from->rep->ns_numrrsets;
2501 to->rep->ar_numrrsets += from->rep->ar_numrrsets;
2502 to->rep->rrset_count = n;
2504 if(from->rep->security < to->rep->security) /* lowest sec */
2505 to->rep->security = from->rep->security;
2506 if(from->rep->qdcount != 0) /* insert qd if appropriate */
2507 to->rep->qdcount = from->rep->qdcount;
2508 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
2509 to->rep->ttl = from->rep->ttl;
2510 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
2511 to->rep->prefetch_ttl = from->rep->prefetch_ttl;
2514 foriq->num_current_queries --;
2515 if(foriq->num_current_queries == 0)
2516 foriq->state = FINISHED_STATE;
2520 * Collect class ANY responses and make them into one response. This
2521 * state is started and it creates queries for all classes (that have
2522 * root hints). The answers are then collected.
2524 * @param qstate: query state.
2525 * @param id: module id.
2526 * @return true if the event needs more immediate processing, false if not.
2529 processCollectClass(struct module_qstate* qstate, int id)
2531 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2532 struct module_qstate* subq;
2533 /* If qchase.qclass == 0 then send out queries for all classes.
2534 * Otherwise, do nothing (wait for all answers to arrive and the
2535 * processClassResponse to put them together, and that moves us
2536 * towards the Finished state when done. */
2537 if(iq->qchase.qclass == 0) {
2539 iq->qchase.qclass = LDNS_RR_CLASS_ANY;
2540 while(iter_get_next_root(qstate->env->hints,
2541 qstate->env->fwds, &c)) {
2542 /* generate query for this class */
2543 log_nametypeclass(VERB_ALGO, "spawn collect query",
2544 qstate->qinfo.qname, qstate->qinfo.qtype, c);
2545 if(!generate_sub_request(qstate->qinfo.qname,
2546 qstate->qinfo.qname_len, qstate->qinfo.qtype,
2547 c, qstate, id, iq, INIT_REQUEST_STATE,
2548 FINISHED_STATE, &subq,
2549 (int)!(qstate->query_flags&BIT_CD))) {
2550 return error_response(qstate, id,
2551 LDNS_RCODE_SERVFAIL);
2553 /* ignore subq, no special init required */
2554 iq->num_current_queries ++;
2559 /* if no roots are configured at all, return */
2560 if(iq->num_current_queries == 0) {
2561 verbose(VERB_ALGO, "No root hints or fwds, giving up "
2563 return error_response(qstate, id, LDNS_RCODE_REFUSED);
2565 /* return false, wait for queries to return */
2567 /* if woke up here because of an answer, wait for more answers */
2572 * This handles the final state for first-tier responses (i.e., responses to
2573 * externally generated queries).
2575 * @param qstate: query state.
2576 * @param iq: iterator query state.
2577 * @param id: module id.
2578 * @return true if the event needs more processing, false if not. Since this
2579 * is the final state for an event, it always returns false.
2582 processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
2585 log_query_info(VERB_QUERY, "finishing processing for",
2588 /* store negative cache element for parent side glue. */
2589 if(iq->query_for_pside_glue && !iq->pside_glue)
2590 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
2591 iq->deleg_msg?iq->deleg_msg->rep:
2592 (iq->response?iq->response->rep:NULL));
2594 verbose(VERB_ALGO, "No response is set, servfail");
2595 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2598 /* Make sure that the RA flag is set (since the presence of
2599 * this module means that recursion is available) */
2600 iq->response->rep->flags |= BIT_RA;
2602 /* Clear the AA flag */
2603 /* FIXME: does this action go here or in some other module? */
2604 iq->response->rep->flags &= ~BIT_AA;
2606 /* make sure QR flag is on */
2607 iq->response->rep->flags |= BIT_QR;
2609 /* we have finished processing this query */
2610 qstate->ext_state[id] = module_finished;
2612 /* TODO: we are using a private TTL, trim the response. */
2613 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
2615 /* prepend any items we have accumulated */
2616 if(iq->an_prepend_list || iq->ns_prepend_list) {
2617 if(!iter_prepend(iq, iq->response, qstate->region)) {
2618 log_err("prepend rrsets: out of memory");
2619 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2621 /* reset the query name back */
2622 iq->response->qinfo = qstate->qinfo;
2623 /* the security state depends on the combination */
2624 iq->response->rep->security = sec_status_unchecked;
2625 /* store message with the finished prepended items,
2626 * but only if we did recursion. The nonrecursion referral
2627 * from cache does not need to be stored in the msg cache. */
2628 if(qstate->query_flags&BIT_RD) {
2629 iter_dns_store(qstate->env, &qstate->qinfo,
2630 iq->response->rep, 0, qstate->prefetch_leeway,
2631 iq->dp&&iq->dp->has_parent_side_NS,
2635 qstate->return_rcode = LDNS_RCODE_NOERROR;
2636 qstate->return_msg = iq->response;
2641 * Return priming query results to interestes super querystates.
2643 * Sets the delegation point and delegation message (not nonRD queries).
2644 * This is a callback from walk_supers.
2646 * @param qstate: query state that finished.
2647 * @param id: module id.
2648 * @param super: the qstate to inform.
2651 iter_inform_super(struct module_qstate* qstate, int id,
2652 struct module_qstate* super)
2654 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
2655 processClassResponse(qstate, id, super);
2656 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
2657 super->minfo[id])->state == DSNS_FIND_STATE)
2658 processDSNSResponse(qstate, id, super);
2659 else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
2660 error_supers(qstate, id, super);
2661 else if(qstate->is_priming)
2662 prime_supers(qstate, id, super);
2663 else processTargetResponse(qstate, id, super);
2667 * Handle iterator state.
2668 * Handle events. This is the real processing loop for events, responsible
2669 * for moving events through the various states. If a processing method
2670 * returns true, then it will be advanced to the next state. If false, then
2671 * processing will stop.
2673 * @param qstate: query state.
2674 * @param ie: iterator shared global environment.
2675 * @param iq: iterator query state.
2676 * @param id: module id.
2679 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
2680 struct iter_env* ie, int id)
2684 verbose(VERB_ALGO, "iter_handle processing q with state %s",
2685 iter_state_to_string(iq->state));
2687 case INIT_REQUEST_STATE:
2688 cont = processInitRequest(qstate, iq, ie, id);
2690 case INIT_REQUEST_2_STATE:
2691 cont = processInitRequest2(qstate, iq, id);
2693 case INIT_REQUEST_3_STATE:
2694 cont = processInitRequest3(qstate, iq, id);
2696 case QUERYTARGETS_STATE:
2697 cont = processQueryTargets(qstate, iq, ie, id);
2699 case QUERY_RESP_STATE:
2700 cont = processQueryResponse(qstate, iq, id);
2702 case PRIME_RESP_STATE:
2703 cont = processPrimeResponse(qstate, id);
2705 case COLLECT_CLASS_STATE:
2706 cont = processCollectClass(qstate, id);
2708 case DSNS_FIND_STATE:
2709 cont = processDSNSFind(qstate, iq, id);
2711 case FINISHED_STATE:
2712 cont = processFinished(qstate, iq, id);
2715 log_warn("iterator: invalid state: %d",
2724 * This is the primary entry point for processing request events. Note that
2725 * this method should only be used by external modules.
2726 * @param qstate: query state.
2727 * @param ie: iterator shared global environment.
2728 * @param iq: iterator query state.
2729 * @param id: module id.
2732 process_request(struct module_qstate* qstate, struct iter_qstate* iq,
2733 struct iter_env* ie, int id)
2735 /* external requests start in the INIT state, and finish using the
2736 * FINISHED state. */
2737 iq->state = INIT_REQUEST_STATE;
2738 iq->final_state = FINISHED_STATE;
2739 verbose(VERB_ALGO, "process_request: new external request event");
2740 iter_handle(qstate, iq, ie, id);
2743 /** process authoritative server reply */
2745 process_response(struct module_qstate* qstate, struct iter_qstate* iq,
2746 struct iter_env* ie, int id, struct outbound_entry* outbound,
2747 enum module_ev event)
2749 struct msg_parse* prs;
2750 struct edns_data edns;
2753 verbose(VERB_ALGO, "process_response: new external response event");
2754 iq->response = NULL;
2755 iq->state = QUERY_RESP_STATE;
2756 if(event == module_event_noreply || event == module_event_error) {
2759 if( (event != module_event_reply && event != module_event_capsfail)
2760 || !qstate->reply) {
2761 log_err("Bad event combined with response");
2762 outbound_list_remove(&iq->outlist, outbound);
2763 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2768 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
2769 sizeof(struct msg_parse));
2771 log_err("out of memory on incoming message");
2772 /* like packet got dropped */
2775 memset(prs, 0, sizeof(*prs));
2776 memset(&edns, 0, sizeof(edns));
2777 pkt = qstate->reply->c->buffer;
2778 ldns_buffer_set_position(pkt, 0);
2779 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
2780 verbose(VERB_ALGO, "parse error on reply packet");
2783 /* edns is not examined, but removed from message to help cache */
2784 if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR)
2786 /* remove CD-bit, we asked for in case we handle validation ourself */
2787 prs->flags &= ~BIT_CD;
2789 /* normalize and sanitize: easy to delete items from linked lists */
2790 if(!scrub_message(pkt, prs, &iq->qchase, iq->dp->name,
2791 qstate->env->scratch, qstate->env, ie))
2794 /* allocate response dns_msg in region */
2795 iq->response = dns_alloc_msg(pkt, prs, qstate->region);
2798 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
2799 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
2800 &qstate->reply->addr, qstate->reply->addrlen);
2801 if(verbosity >= VERB_ALGO)
2802 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
2805 if(event == module_event_capsfail) {
2806 if(!iq->caps_fallback) {
2807 /* start fallback */
2808 iq->caps_fallback = 1;
2809 iq->caps_server = 0;
2810 iq->caps_reply = iq->response->rep;
2811 iq->state = QUERYTARGETS_STATE;
2812 iq->num_current_queries--;
2813 verbose(VERB_DETAIL, "Capsforid: starting fallback");
2816 /* check if reply is the same, otherwise, fail */
2817 if(!reply_equal(iq->response->rep, iq->caps_reply,
2818 qstate->env->scratch_buffer)) {
2819 verbose(VERB_DETAIL, "Capsforid fallback: "
2820 "getting different replies, failed");
2821 outbound_list_remove(&iq->outlist, outbound);
2822 (void)error_response(qstate, id,
2823 LDNS_RCODE_SERVFAIL);
2826 /* continue the fallback procedure at next server */
2828 iq->state = QUERYTARGETS_STATE;
2829 iq->num_current_queries--;
2830 verbose(VERB_DETAIL, "Capsforid: reply is equal. "
2831 "go to next fallback");
2835 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
2838 outbound_list_remove(&iq->outlist, outbound);
2839 iter_handle(qstate, iq, ie, id);
2843 iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
2844 struct outbound_entry* outbound)
2846 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
2847 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
2848 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
2849 id, strextstate(qstate->ext_state[id]), strmodulevent(event));
2850 if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
2852 if(iq && qstate->qinfo.qname != iq->qchase.qname)
2853 log_query_info(VERB_QUERY, "iterator operate: chased to",
2856 /* perform iterator state machine */
2857 if((event == module_event_new || event == module_event_pass) &&
2859 if(!iter_new(qstate, id)) {
2860 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2863 iq = (struct iter_qstate*)qstate->minfo[id];
2864 process_request(qstate, iq, ie, id);
2867 if(iq && event == module_event_pass) {
2868 iter_handle(qstate, iq, ie, id);
2871 if(iq && outbound) {
2872 process_response(qstate, iq, ie, id, outbound, event);
2875 if(event == module_event_error) {
2876 verbose(VERB_ALGO, "got called with event error, giving up");
2877 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2881 log_err("bad event for iterator");
2882 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2886 iter_clear(struct module_qstate* qstate, int id)
2888 struct iter_qstate* iq;
2891 iq = (struct iter_qstate*)qstate->minfo[id];
2893 outbound_list_clear(&iq->outlist);
2894 iq->num_current_queries = 0;
2896 qstate->minfo[id] = NULL;
2900 iter_get_mem(struct module_env* env, int id)
2902 struct iter_env* ie = (struct iter_env*)env->modinfo[id];
2905 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
2906 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
2910 * The iterator function block
2912 static struct module_func_block iter_block = {
2914 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
2915 &iter_clear, &iter_get_mem
2918 struct module_func_block*
2919 iter_get_funcblock(void)
2925 iter_state_to_string(enum iter_state state)
2929 case INIT_REQUEST_STATE :
2930 return "INIT REQUEST STATE";
2931 case INIT_REQUEST_2_STATE :
2932 return "INIT REQUEST STATE (stage 2)";
2933 case INIT_REQUEST_3_STATE:
2934 return "INIT REQUEST STATE (stage 3)";
2935 case QUERYTARGETS_STATE :
2936 return "QUERY TARGETS STATE";
2937 case PRIME_RESP_STATE :
2938 return "PRIME RESPONSE STATE";
2939 case COLLECT_CLASS_STATE :
2940 return "COLLECT CLASS STATE";
2941 case DSNS_FIND_STATE :
2942 return "DSNS FIND STATE";
2943 case QUERY_RESP_STATE :
2944 return "QUERY RESPONSE STATE";
2945 case FINISHED_STATE :
2946 return "FINISHED RESPONSE STATE";
2948 return "UNKNOWN ITER STATE";
2953 iter_state_is_responsestate(enum iter_state s)
2956 case INIT_REQUEST_STATE :
2957 case INIT_REQUEST_2_STATE :
2958 case INIT_REQUEST_3_STATE :
2959 case QUERYTARGETS_STATE :
2960 case COLLECT_CLASS_STATE :