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
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19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 * This file contains a module that performs recursive iterative DNS query
44 #include "iterator/iterator.h"
45 #include "iterator/iter_utils.h"
46 #include "iterator/iter_hints.h"
47 #include "iterator/iter_fwd.h"
48 #include "iterator/iter_donotq.h"
49 #include "iterator/iter_delegpt.h"
50 #include "iterator/iter_resptype.h"
51 #include "iterator/iter_scrub.h"
52 #include "iterator/iter_priv.h"
53 #include "validator/val_neg.h"
54 #include "services/cache/dns.h"
55 #include "services/cache/infra.h"
56 #include "services/authzone.h"
57 #include "util/module.h"
58 #include "util/netevent.h"
59 #include "util/net_help.h"
60 #include "util/regional.h"
61 #include "util/data/dname.h"
62 #include "util/data/msgencode.h"
63 #include "util/fptr_wlist.h"
64 #include "util/config_file.h"
65 #include "util/random.h"
66 #include "sldns/rrdef.h"
67 #include "sldns/wire2str.h"
68 #include "sldns/str2wire.h"
69 #include "sldns/parseutil.h"
70 #include "sldns/sbuffer.h"
73 int UNKNOWN_SERVER_NICENESS = 376;
75 static void target_count_increase_nx(struct iter_qstate* iq, int num);
78 iter_init(struct module_env* env, int id)
80 struct iter_env* iter_env = (struct iter_env*)calloc(1,
81 sizeof(struct iter_env));
83 log_err("malloc failure");
86 env->modinfo[id] = (void*)iter_env;
88 lock_basic_init(&iter_env->queries_ratelimit_lock);
89 lock_protect(&iter_env->queries_ratelimit_lock,
90 &iter_env->num_queries_ratelimited,
91 sizeof(iter_env->num_queries_ratelimited));
93 if(!iter_apply_cfg(iter_env, env->cfg)) {
94 log_err("iterator: could not apply configuration settings.");
101 /** delete caps_whitelist element */
103 caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d))
106 free(((struct name_tree_node*)n)->name);
112 iter_deinit(struct module_env* env, int id)
114 struct iter_env* iter_env;
115 if(!env || !env->modinfo[id])
117 iter_env = (struct iter_env*)env->modinfo[id];
118 lock_basic_destroy(&iter_env->queries_ratelimit_lock);
119 free(iter_env->target_fetch_policy);
120 priv_delete(iter_env->priv);
121 donotq_delete(iter_env->donotq);
122 if(iter_env->caps_white) {
123 traverse_postorder(iter_env->caps_white, caps_free, NULL);
124 free(iter_env->caps_white);
127 env->modinfo[id] = NULL;
130 /** new query for iterator */
132 iter_new(struct module_qstate* qstate, int id)
134 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc(
135 qstate->region, sizeof(struct iter_qstate));
136 qstate->minfo[id] = iq;
139 memset(iq, 0, sizeof(*iq));
140 iq->state = INIT_REQUEST_STATE;
141 iq->final_state = FINISHED_STATE;
142 iq->an_prepend_list = NULL;
143 iq->an_prepend_last = NULL;
144 iq->ns_prepend_list = NULL;
145 iq->ns_prepend_last = NULL;
148 iq->num_target_queries = 0;
149 iq->num_current_queries = 0;
150 iq->query_restart_count = 0;
151 iq->referral_count = 0;
153 iq->ratelimit_ok = 0;
154 iq->target_count = NULL;
155 iq->dp_target_count = 0;
156 iq->wait_priming_stub = 0;
157 iq->refetch_glue = 0;
158 iq->dnssec_expected = 0;
159 iq->dnssec_lame_query = 0;
160 iq->chase_flags = qstate->query_flags;
161 /* Start with the (current) qname. */
162 iq->qchase = qstate->qinfo;
163 outbound_list_init(&iq->outlist);
164 iq->minimise_count = 0;
165 iq->timeout_count = 0;
166 if (qstate->env->cfg->qname_minimisation)
167 iq->minimisation_state = INIT_MINIMISE_STATE;
169 iq->minimisation_state = DONOT_MINIMISE_STATE;
171 memset(&iq->qinfo_out, 0, sizeof(struct query_info));
176 * Transition to the next state. This can be used to advance a currently
177 * processing event. It cannot be used to reactivate a forEvent.
179 * @param iq: iterator query state
180 * @param nextstate The state to transition to.
181 * @return true. This is so this can be called as the return value for the
182 * actual process*State() methods. (Transitioning to the next state
183 * implies further processing).
186 next_state(struct iter_qstate* iq, enum iter_state nextstate)
188 /* If transitioning to a "response" state, make sure that there is a
190 if(iter_state_is_responsestate(nextstate)) {
191 if(iq->response == NULL) {
192 log_err("transitioning to response state sans "
196 iq->state = nextstate;
201 * Transition an event to its final state. Final states always either return
202 * a result up the module chain, or reactivate a dependent event. Which
203 * final state to transition to is set in the module state for the event when
204 * it was created, and depends on the original purpose of the event.
206 * The response is stored in the qstate->buf buffer.
208 * @param iq: iterator query state
209 * @return false. This is so this method can be used as the return value for
210 * the processState methods. (Transitioning to the final state
213 final_state(struct iter_qstate* iq)
215 return next_state(iq, iq->final_state);
219 * Callback routine to handle errors in parent query states
220 * @param qstate: query state that failed.
221 * @param id: module id.
222 * @param super: super state.
225 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
227 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
228 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
230 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
231 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
232 /* mark address as failed. */
233 struct delegpt_ns* dpns = NULL;
234 super_iq->num_target_queries--;
236 dpns = delegpt_find_ns(super_iq->dp,
237 qstate->qinfo.qname, qstate->qinfo.qname_len);
240 /* this can happen, for eg. qname minimisation asked
241 * for an NXDOMAIN to be validated, and used qtype
242 * A for that, and the error of that, the name, is
243 * not listed in super_iq->dp */
244 verbose(VERB_ALGO, "subq error, but not interested");
245 log_query_info(VERB_ALGO, "superq", &super->qinfo);
248 /* see if the failure did get (parent-lame) info */
249 if(!cache_fill_missing(super->env, super_iq->qchase.qclass,
250 super->region, super_iq->dp))
251 log_err("out of memory adding missing");
253 delegpt_mark_neg(dpns, qstate->qinfo.qtype);
254 dpns->resolved = 1; /* mark as failed */
255 if((dpns->got4 == 2 || !ie->supports_ipv4) &&
256 (dpns->got6 == 2 || !ie->supports_ipv6))
257 target_count_increase_nx(super_iq, 1);
259 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
260 /* prime failed to get delegation */
263 /* evaluate targets again */
264 super_iq->state = QUERYTARGETS_STATE;
265 /* super becomes runnable, and will process this change */
269 * Return an error to the client
270 * @param qstate: our query state
271 * @param id: module id
272 * @param rcode: error code (DNS errcode).
273 * @return: 0 for use by caller, to make notation easy, like:
274 * return error_response(..).
277 error_response(struct module_qstate* qstate, int id, int rcode)
279 verbose(VERB_QUERY, "return error response %s",
280 sldns_lookup_by_id(sldns_rcodes, rcode)?
281 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
282 qstate->return_rcode = rcode;
283 qstate->return_msg = NULL;
284 qstate->ext_state[id] = module_finished;
289 * Return an error to the client and cache the error code in the
290 * message cache (so per qname, qtype, qclass).
291 * @param qstate: our query state
292 * @param id: module id
293 * @param rcode: error code (DNS errcode).
294 * @return: 0 for use by caller, to make notation easy, like:
295 * return error_response(..).
298 error_response_cache(struct module_qstate* qstate, int id, int rcode)
300 if(!qstate->no_cache_store) {
302 struct reply_info err;
303 if(qstate->prefetch_leeway > NORR_TTL) {
304 verbose(VERB_ALGO, "error response for prefetch in cache");
305 /* attempt to adjust the cache entry prefetch */
306 if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,
307 NORR_TTL, qstate->query_flags))
308 return error_response(qstate, id, rcode);
309 /* if that fails (not in cache), fall through to store err */
311 if(qstate->env->cfg->serve_expired) {
312 /* if serving expired contents, and such content is
313 * already available, don't overwrite this servfail */
314 struct msgreply_entry* msg;
315 if((msg=msg_cache_lookup(qstate->env,
316 qstate->qinfo.qname, qstate->qinfo.qname_len,
317 qstate->qinfo.qtype, qstate->qinfo.qclass,
318 qstate->query_flags, 0,
319 qstate->env->cfg->serve_expired_ttl_reset))
321 if(qstate->env->cfg->serve_expired_ttl_reset) {
322 struct reply_info* rep =
323 (struct reply_info*)msg->entry.data;
324 if(rep && *qstate->env->now +
325 qstate->env->cfg->serve_expired_ttl >
326 rep->serve_expired_ttl) {
327 rep->serve_expired_ttl =
329 qstate->env->cfg->serve_expired_ttl;
332 lock_rw_unlock(&msg->entry.lock);
333 return error_response(qstate, id, rcode);
335 /* serving expired contents, but nothing is cached
336 * at all, so the servfail cache entry is useful
337 * (stops waste of time on this servfail NORR_TTL) */
339 /* don't overwrite existing (non-expired) data in
340 * cache with a servfail */
341 struct msgreply_entry* msg;
342 if((msg=msg_cache_lookup(qstate->env,
343 qstate->qinfo.qname, qstate->qinfo.qname_len,
344 qstate->qinfo.qtype, qstate->qinfo.qclass,
345 qstate->query_flags, *qstate->env->now, 0))
347 struct reply_info* rep = (struct reply_info*)
349 if(FLAGS_GET_RCODE(rep->flags) ==
350 LDNS_RCODE_NOERROR ||
351 FLAGS_GET_RCODE(rep->flags) ==
352 LDNS_RCODE_NXDOMAIN) {
353 /* we have a good entry,
355 lock_rw_unlock(&msg->entry.lock);
356 return error_response(qstate, id, rcode);
358 lock_rw_unlock(&msg->entry.lock);
362 memset(&err, 0, sizeof(err));
363 err.flags = (uint16_t)(BIT_QR | BIT_RA);
364 FLAGS_SET_RCODE(err.flags, rcode);
367 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
368 err.serve_expired_ttl = NORR_TTL;
369 /* do not waste time trying to validate this servfail */
370 err.security = sec_status_indeterminate;
371 verbose(VERB_ALGO, "store error response in message cache");
372 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL,
373 qstate->query_flags);
375 return error_response(qstate, id, rcode);
378 /** check if prepend item is duplicate item */
380 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
381 struct ub_packed_rrset_key* dup)
384 for(i=0; i<to; i++) {
385 if(sets[i]->rk.type == dup->rk.type &&
386 sets[i]->rk.rrset_class == dup->rk.rrset_class &&
387 sets[i]->rk.dname_len == dup->rk.dname_len &&
388 query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
395 /** prepend the prepend list in the answer and authority section of dns_msg */
397 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
398 struct regional* region)
400 struct iter_prep_list* p;
401 struct ub_packed_rrset_key** sets;
402 size_t num_an = 0, num_ns = 0;;
403 for(p = iq->an_prepend_list; p; p = p->next)
405 for(p = iq->ns_prepend_list; p; p = p->next)
407 if(num_an + num_ns == 0)
409 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
410 if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX ||
411 msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */
412 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) *
413 sizeof(struct ub_packed_rrset_key*));
418 for(p = iq->an_prepend_list; p; p = p->next) {
419 sets[num_an++] = p->rrset;
420 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl)
421 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset);
423 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
424 sizeof(struct ub_packed_rrset_key*));
427 for(p = iq->ns_prepend_list; p; p = p->next) {
428 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
429 num_ns, p->rrset) || prepend_is_duplicate(
430 msg->rep->rrsets+msg->rep->an_numrrsets,
431 msg->rep->ns_numrrsets, p->rrset))
433 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
434 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl)
435 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset);
437 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
438 msg->rep->rrsets + msg->rep->an_numrrsets,
439 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
440 sizeof(struct ub_packed_rrset_key*));
442 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
443 * this is what recursors should give. */
444 msg->rep->rrset_count += num_an + num_ns;
445 msg->rep->an_numrrsets += num_an;
446 msg->rep->ns_numrrsets += num_ns;
447 msg->rep->rrsets = sets;
452 * Find rrset in ANSWER prepend list.
453 * to avoid duplicate DNAMEs when a DNAME is traversed twice.
454 * @param iq: iterator query state.
455 * @param rrset: rrset to add.
456 * @return false if not found
459 iter_find_rrset_in_prepend_answer(struct iter_qstate* iq,
460 struct ub_packed_rrset_key* rrset)
462 struct iter_prep_list* p = iq->an_prepend_list;
464 if(ub_rrset_compare(p->rrset, rrset) == 0 &&
465 rrsetdata_equal((struct packed_rrset_data*)p->rrset
466 ->entry.data, (struct packed_rrset_data*)rrset
475 * Add rrset to ANSWER prepend list
476 * @param qstate: query state.
477 * @param iq: iterator query state.
478 * @param rrset: rrset to add.
479 * @return false on failure (malloc).
482 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq,
483 struct ub_packed_rrset_key* rrset)
485 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
486 qstate->region, sizeof(struct iter_prep_list));
492 if(iq->an_prepend_last)
493 iq->an_prepend_last->next = p;
494 else iq->an_prepend_list = p;
495 iq->an_prepend_last = p;
500 * Add rrset to AUTHORITY prepend list
501 * @param qstate: query state.
502 * @param iq: iterator query state.
503 * @param rrset: rrset to add.
504 * @return false on failure (malloc).
507 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq,
508 struct ub_packed_rrset_key* rrset)
510 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
511 qstate->region, sizeof(struct iter_prep_list));
517 if(iq->ns_prepend_last)
518 iq->ns_prepend_last->next = p;
519 else iq->ns_prepend_list = p;
520 iq->ns_prepend_last = p;
525 * Given a CNAME response (defined as a response containing a CNAME or DNAME
526 * that does not answer the request), process the response, modifying the
527 * state as necessary. This follows the CNAME/DNAME chain and returns the
530 * sets the new query name, after following the CNAME/DNAME chain.
531 * @param qstate: query state.
532 * @param iq: iterator query state.
533 * @param msg: the response.
534 * @param mname: returned target new query name.
535 * @param mname_len: length of mname.
536 * @return false on (malloc) error.
539 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
540 struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
543 /* Start with the (current) qname. */
544 *mname = iq->qchase.qname;
545 *mname_len = iq->qchase.qname_len;
547 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
549 for(i=0; i<msg->rep->an_numrrsets; i++) {
550 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
551 /* If there is a (relevant) DNAME, add it to the list.
552 * We always expect there to be CNAME that was generated
553 * by this DNAME following, so we don't process the DNAME
555 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
556 dname_strict_subdomain_c(*mname, r->rk.dname) &&
557 !iter_find_rrset_in_prepend_answer(iq, r)) {
558 if(!iter_add_prepend_answer(qstate, iq, r))
563 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
564 query_dname_compare(*mname, r->rk.dname) == 0 &&
565 !iter_find_rrset_in_prepend_answer(iq, r)) {
566 /* Add this relevant CNAME rrset to the prepend list.*/
567 if(!iter_add_prepend_answer(qstate, iq, r))
569 get_cname_target(r, mname, mname_len);
572 /* Other rrsets in the section are ignored. */
574 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */
575 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
576 msg->rep->ns_numrrsets; i++) {
577 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
578 /* only add NSEC/NSEC3, as they may be needed for validation */
579 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
580 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
581 if(!iter_add_prepend_auth(qstate, iq, r))
588 /** see if last resort is possible - does config allow queries to parent */
590 can_have_last_resort(struct module_env* env, uint8_t* nm, size_t nmlen,
591 uint16_t qclass, struct delegpt** retdp)
593 struct delegpt* fwddp;
594 struct iter_hints_stub* stub;
595 int labs = dname_count_labels(nm);
596 /* do not process a last resort (the parent side) if a stub
597 * or forward is configured, because we do not want to go 'above'
598 * the configured servers */
599 if(!dname_is_root(nm) && (stub = (struct iter_hints_stub*)
600 name_tree_find(&env->hints->tree, nm, nmlen, labs, qclass)) &&
601 /* has_parent side is turned off for stub_first, where we
602 * are allowed to go to the parent */
603 stub->dp->has_parent_side_NS) {
604 if(retdp) *retdp = stub->dp;
607 if((fwddp = forwards_find(env->fwds, nm, qclass)) &&
608 /* has_parent_side is turned off for forward_first, where
609 * we are allowed to go to the parent */
610 fwddp->has_parent_side_NS) {
611 if(retdp) *retdp = fwddp;
617 /** see if target name is caps-for-id whitelisted */
619 is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq)
621 if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */
622 return name_tree_lookup(ie->caps_white, iq->qchase.qname,
623 iq->qchase.qname_len, dname_count_labels(iq->qchase.qname),
624 iq->qchase.qclass) != NULL;
627 /** create target count structure for this query */
629 target_count_create(struct iter_qstate* iq)
631 if(!iq->target_count) {
632 iq->target_count = (int*)calloc(3, sizeof(int));
633 /* if calloc fails we simply do not track this number */
635 iq->target_count[0] = 1;
640 target_count_increase(struct iter_qstate* iq, int num)
642 target_count_create(iq);
644 iq->target_count[1] += num;
645 iq->dp_target_count++;
649 target_count_increase_nx(struct iter_qstate* iq, int num)
651 target_count_create(iq);
653 iq->target_count[2] += num;
657 * Generate a subrequest.
658 * Generate a local request event. Local events are tied to this module, and
659 * have a corresponding (first tier) event that is waiting for this event to
660 * resolve to continue.
662 * @param qname The query name for this request.
663 * @param qnamelen length of qname
664 * @param qtype The query type for this request.
665 * @param qclass The query class for this request.
666 * @param qstate The event that is generating this event.
667 * @param id: module id.
668 * @param iq: The iterator state that is generating this event.
669 * @param initial_state The initial response state (normally this
670 * is QUERY_RESP_STATE, unless it is known that the request won't
671 * need iterative processing
672 * @param finalstate The final state for the response to this request.
673 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
674 * not need initialisation.
675 * @param v: if true, validation is done on the subquery.
676 * @param detached: true if this qstate should not attach to the subquery
677 * @return false on error (malloc).
680 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
681 uint16_t qclass, struct module_qstate* qstate, int id,
682 struct iter_qstate* iq, enum iter_state initial_state,
683 enum iter_state finalstate, struct module_qstate** subq_ret, int v,
686 struct module_qstate* subq = NULL;
687 struct iter_qstate* subiq = NULL;
688 uint16_t qflags = 0; /* OPCODE QUERY, no flags */
689 struct query_info qinf;
690 int prime = (finalstate == PRIME_RESP_STATE)?1:0;
693 qinf.qname_len = qnamelen;
695 qinf.qclass = qclass;
696 qinf.local_alias = NULL;
698 /* RD should be set only when sending the query back through the INIT
700 if(initial_state == INIT_REQUEST_STATE)
702 /* We set the CD flag so we can send this through the "head" of
703 * the resolution chain, which might have a validator. We are
704 * uninterested in validating things not on the direct resolution
712 struct mesh_state* sub = NULL;
713 fptr_ok(fptr_whitelist_modenv_add_sub(
714 qstate->env->add_sub));
715 if(!(*qstate->env->add_sub)(qstate, &qinf,
716 qflags, prime, valrec, &subq, &sub)){
721 /* attach subquery, lookup existing or make a new one */
722 fptr_ok(fptr_whitelist_modenv_attach_sub(
723 qstate->env->attach_sub));
724 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime,
731 /* initialise the new subquery */
733 subq->ext_state[id] = module_state_initial;
734 subq->minfo[id] = regional_alloc(subq->region,
735 sizeof(struct iter_qstate));
736 if(!subq->minfo[id]) {
737 log_err("init subq: out of memory");
738 fptr_ok(fptr_whitelist_modenv_kill_sub(
739 qstate->env->kill_sub));
740 (*qstate->env->kill_sub)(subq);
743 subiq = (struct iter_qstate*)subq->minfo[id];
744 memset(subiq, 0, sizeof(*subiq));
745 subiq->num_target_queries = 0;
746 target_count_create(iq);
747 subiq->target_count = iq->target_count;
749 iq->target_count[0] ++; /* extra reference */
750 subiq->dp_target_count = 0;
751 subiq->num_current_queries = 0;
752 subiq->depth = iq->depth+1;
753 outbound_list_init(&subiq->outlist);
754 subiq->state = initial_state;
755 subiq->final_state = finalstate;
756 subiq->qchase = subq->qinfo;
757 subiq->chase_flags = subq->query_flags;
758 subiq->refetch_glue = 0;
759 if(qstate->env->cfg->qname_minimisation)
760 subiq->minimisation_state = INIT_MINIMISE_STATE;
762 subiq->minimisation_state = DONOT_MINIMISE_STATE;
763 memset(&subiq->qinfo_out, 0, sizeof(struct query_info));
769 * Generate and send a root priming request.
770 * @param qstate: the qtstate that triggered the need to prime.
771 * @param iq: iterator query state.
772 * @param id: module id.
773 * @param qclass: the class to prime.
774 * @return 0 on failure
777 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
781 struct module_qstate* subq;
782 verbose(VERB_DETAIL, "priming . %s NS",
783 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)?
784 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??");
785 dp = hints_lookup_root(qstate->env->hints, qclass);
787 verbose(VERB_ALGO, "Cannot prime due to lack of hints");
790 /* Priming requests start at the QUERYTARGETS state, skipping
791 * the normal INIT state logic (which would cause an infloop). */
792 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
793 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
795 verbose(VERB_ALGO, "could not prime root");
799 struct iter_qstate* subiq =
800 (struct iter_qstate*)subq->minfo[id];
801 /* Set the initial delegation point to the hint.
802 * copy dp, it is now part of the root prime query.
803 * dp was part of in the fixed hints structure. */
804 subiq->dp = delegpt_copy(dp, subq->region);
806 log_err("out of memory priming root, copydp");
807 fptr_ok(fptr_whitelist_modenv_kill_sub(
808 qstate->env->kill_sub));
809 (*qstate->env->kill_sub)(subq);
812 /* there should not be any target queries. */
813 subiq->num_target_queries = 0;
814 subiq->dnssec_expected = iter_indicates_dnssec(
815 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
818 /* this module stops, our submodule starts, and does the query. */
819 qstate->ext_state[id] = module_wait_subquery;
824 * Generate and process a stub priming request. This method tests for the
825 * need to prime a stub zone, so it is safe to call for every request.
827 * @param qstate: the qtstate that triggered the need to prime.
828 * @param iq: iterator query state.
829 * @param id: module id.
830 * @param qname: request name.
831 * @param qclass: request class.
832 * @return true if a priming subrequest was made, false if not. The will only
833 * issue a priming request if it detects an unprimed stub.
834 * Uses value of 2 to signal during stub-prime in root-prime situation
835 * that a noprime-stub is available and resolution can continue.
838 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id,
839 uint8_t* qname, uint16_t qclass)
841 /* Lookup the stub hint. This will return null if the stub doesn't
842 * need to be re-primed. */
843 struct iter_hints_stub* stub;
844 struct delegpt* stub_dp;
845 struct module_qstate* subq;
848 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
849 /* The stub (if there is one) does not need priming. */
853 /* if we have an auth_zone dp, and stub is equal, don't prime stub
854 * yet, unless we want to fallback and avoid the auth_zone */
855 if(!iq->auth_zone_avoid && iq->dp && iq->dp->auth_dp &&
856 query_dname_compare(iq->dp->name, stub_dp->name) == 0)
859 /* is it a noprime stub (always use) */
862 if(iq->dp == NULL) r = 2;
863 /* copy the dp out of the fixed hints structure, so that
864 * it can be changed when servicing this query */
865 iq->dp = delegpt_copy(stub_dp, qstate->region);
867 log_err("out of memory priming stub");
868 errinf(qstate, "malloc failure, priming stub");
869 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
870 return 1; /* return 1 to make module stop, with error */
872 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
873 LDNS_RR_TYPE_NS, qclass);
877 /* Otherwise, we need to (re)prime the stub. */
878 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name,
879 LDNS_RR_TYPE_NS, qclass);
881 /* Stub priming events start at the QUERYTARGETS state to avoid the
882 * redundant INIT state processing. */
883 if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
884 LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
885 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0, 0)) {
886 verbose(VERB_ALGO, "could not prime stub");
887 errinf(qstate, "could not generate lookup for stub prime");
888 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
889 return 1; /* return 1 to make module stop, with error */
892 struct iter_qstate* subiq =
893 (struct iter_qstate*)subq->minfo[id];
895 /* Set the initial delegation point to the hint. */
896 /* make copy to avoid use of stub dp by different qs/threads */
897 subiq->dp = delegpt_copy(stub_dp, subq->region);
899 log_err("out of memory priming stub, copydp");
900 fptr_ok(fptr_whitelist_modenv_kill_sub(
901 qstate->env->kill_sub));
902 (*qstate->env->kill_sub)(subq);
903 errinf(qstate, "malloc failure, in stub prime");
904 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
905 return 1; /* return 1 to make module stop, with error */
907 /* there should not be any target queries -- although there
908 * wouldn't be anyway, since stub hints never have
909 * missing targets. */
910 subiq->num_target_queries = 0;
911 subiq->wait_priming_stub = 1;
912 subiq->dnssec_expected = iter_indicates_dnssec(
913 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
916 /* this module stops, our submodule starts, and does the query. */
917 qstate->ext_state[id] = module_wait_subquery;
922 * Generate a delegation point for an auth zone (unless cached dp is better)
923 * false on alloc failure.
926 auth_zone_delegpt(struct module_qstate* qstate, struct iter_qstate* iq,
927 uint8_t* delname, size_t delnamelen)
930 if(iq->auth_zone_avoid)
933 delname = iq->qchase.qname;
934 delnamelen = iq->qchase.qname_len;
936 lock_rw_rdlock(&qstate->env->auth_zones->lock);
937 z = auth_zones_find_zone(qstate->env->auth_zones, delname, delnamelen,
938 qstate->qinfo.qclass);
940 lock_rw_unlock(&qstate->env->auth_zones->lock);
943 lock_rw_rdlock(&z->lock);
944 lock_rw_unlock(&qstate->env->auth_zones->lock);
945 if(z->for_upstream) {
946 if(iq->dp && query_dname_compare(z->name, iq->dp->name) == 0
947 && iq->dp->auth_dp && qstate->blacklist &&
948 z->fallback_enabled) {
949 /* cache is blacklisted and fallback, and we
950 * already have an auth_zone dp */
951 if(verbosity>=VERB_ALGO) {
953 dname_str(z->name, buf);
954 verbose(VERB_ALGO, "auth_zone %s "
955 "fallback because cache blacklisted",
958 lock_rw_unlock(&z->lock);
962 if(iq->dp==NULL || dname_subdomain_c(z->name, iq->dp->name)) {
964 if(qstate->blacklist && z->fallback_enabled) {
965 /* cache is blacklisted because of a DNSSEC
966 * validation failure, and the zone allows
967 * fallback to the internet, query there. */
968 if(verbosity>=VERB_ALGO) {
970 dname_str(z->name, buf);
971 verbose(VERB_ALGO, "auth_zone %s "
972 "fallback because cache blacklisted",
975 lock_rw_unlock(&z->lock);
978 dp = (struct delegpt*)regional_alloc_zero(
979 qstate->region, sizeof(*dp));
981 log_err("alloc failure");
982 if(z->fallback_enabled) {
983 lock_rw_unlock(&z->lock);
984 return 1; /* just fallback */
986 lock_rw_unlock(&z->lock);
987 errinf(qstate, "malloc failure");
990 dp->name = regional_alloc_init(qstate->region,
991 z->name, z->namelen);
993 log_err("alloc failure");
994 if(z->fallback_enabled) {
995 lock_rw_unlock(&z->lock);
996 return 1; /* just fallback */
998 lock_rw_unlock(&z->lock);
999 errinf(qstate, "malloc failure");
1002 dp->namelen = z->namelen;
1003 dp->namelabs = z->namelabs;
1009 lock_rw_unlock(&z->lock);
1014 * Generate A and AAAA checks for glue that is in-zone for the referral
1015 * we just got to obtain authoritative information on the addresses.
1017 * @param qstate: the qtstate that triggered the need to prime.
1018 * @param iq: iterator query state.
1019 * @param id: module id.
1022 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
1025 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
1026 struct module_qstate* subq;
1028 struct reply_info* rep = iq->response->rep;
1029 struct ub_packed_rrset_key* s;
1032 if(iq->depth == ie->max_dependency_depth)
1034 /* walk through additional, and check if in-zone,
1035 * only relevant A, AAAA are left after scrub anyway */
1036 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
1038 /* check *ALL* addresses that are transmitted in additional*/
1039 /* is it an address ? */
1040 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
1041 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
1044 /* is this query the same as the A/AAAA check for it */
1045 if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
1046 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
1047 query_dname_compare(qstate->qinfo.qname,
1049 (qstate->query_flags&BIT_RD) &&
1050 !(qstate->query_flags&BIT_CD))
1053 /* generate subrequest for it */
1054 log_nametypeclass(VERB_ALGO, "schedule addr fetch",
1055 s->rk.dname, ntohs(s->rk.type),
1056 ntohs(s->rk.rrset_class));
1057 if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
1058 ntohs(s->rk.type), ntohs(s->rk.rrset_class),
1060 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
1061 verbose(VERB_ALGO, "could not generate addr check");
1064 /* ignore subq - not need for more init */
1069 * Generate a NS check request to obtain authoritative information
1072 * @param qstate: the qtstate that triggered the need to prime.
1073 * @param iq: iterator query state.
1074 * @param id: module id.
1077 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
1079 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
1080 struct module_qstate* subq;
1083 if(iq->depth == ie->max_dependency_depth)
1085 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen,
1086 iq->qchase.qclass, NULL))
1088 /* is this query the same as the nscheck? */
1089 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
1090 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
1091 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
1092 /* spawn off A, AAAA queries for in-zone glue to check */
1093 generate_a_aaaa_check(qstate, iq, id);
1096 /* no need to get the NS record for DS, it is above the zonecut */
1097 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS)
1100 log_nametypeclass(VERB_ALGO, "schedule ns fetch",
1101 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
1102 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
1103 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
1104 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
1105 verbose(VERB_ALGO, "could not generate ns check");
1109 struct iter_qstate* subiq =
1110 (struct iter_qstate*)subq->minfo[id];
1112 /* make copy to avoid use of stub dp by different qs/threads */
1113 /* refetch glue to start higher up the tree */
1114 subiq->refetch_glue = 1;
1115 subiq->dp = delegpt_copy(iq->dp, subq->region);
1117 log_err("out of memory generating ns check, copydp");
1118 fptr_ok(fptr_whitelist_modenv_kill_sub(
1119 qstate->env->kill_sub));
1120 (*qstate->env->kill_sub)(subq);
1127 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
1128 * just got in a referral (where we have dnssec_expected, thus have trust
1129 * anchors above it). Note that right after calling this routine the
1130 * iterator detached subqueries (because of following the referral), and thus
1131 * the DNSKEY query becomes detached, its return stored in the cache for
1132 * later lookup by the validator. This cache lookup by the validator avoids
1133 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
1134 * performed at about the same time the original query is sent to the domain,
1135 * thus the two answers are likely to be returned at about the same time,
1136 * saving a roundtrip from the validated lookup.
1138 * @param qstate: the qtstate that triggered the need to prime.
1139 * @param iq: iterator query state.
1140 * @param id: module id.
1143 generate_dnskey_prefetch(struct module_qstate* qstate,
1144 struct iter_qstate* iq, int id)
1146 struct module_qstate* subq;
1149 /* is this query the same as the prefetch? */
1150 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
1151 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
1152 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
1156 /* if the DNSKEY is in the cache this lookup will stop quickly */
1157 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
1158 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
1159 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
1160 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
1161 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) {
1162 /* we'll be slower, but it'll work */
1163 verbose(VERB_ALGO, "could not generate dnskey prefetch");
1167 struct iter_qstate* subiq =
1168 (struct iter_qstate*)subq->minfo[id];
1169 /* this qstate has the right delegation for the dnskey lookup*/
1170 /* make copy to avoid use of stub dp by different qs/threads */
1171 subiq->dp = delegpt_copy(iq->dp, subq->region);
1172 /* if !subiq->dp, it'll start from the cache, no problem */
1177 * See if the query needs forwarding.
1179 * @param qstate: query state.
1180 * @param iq: iterator query state.
1181 * @return true if the request is forwarded, false if not.
1182 * If returns true but, iq->dp is NULL then a malloc failure occurred.
1185 forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
1188 uint8_t* delname = iq->qchase.qname;
1189 size_t delnamelen = iq->qchase.qname_len;
1190 if(iq->refetch_glue && iq->dp) {
1191 delname = iq->dp->name;
1192 delnamelen = iq->dp->namelen;
1194 /* strip one label off of DS query to lookup higher for it */
1195 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
1196 && !dname_is_root(iq->qchase.qname))
1197 dname_remove_label(&delname, &delnamelen);
1198 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
1201 /* send recursion desired to forward addr */
1202 iq->chase_flags |= BIT_RD;
1203 iq->dp = delegpt_copy(dp, qstate->region);
1204 /* iq->dp checked by caller */
1205 verbose(VERB_ALGO, "forwarding request");
1210 * Process the initial part of the request handling. This state roughly
1211 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2
1212 * (find the best servers to ask).
1214 * Note that all requests start here, and query restarts revisit this state.
1216 * This state either generates: 1) a response, from cache or error, 2) a
1217 * priming event, or 3) forwards the request to the next state (init2,
1220 * @param qstate: query state.
1221 * @param iq: iterator query state.
1222 * @param ie: iterator shared global environment.
1223 * @param id: module id.
1224 * @return true if the event needs more request processing immediately,
1228 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
1229 struct iter_env* ie, int id)
1233 struct dns_msg* msg = NULL;
1235 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
1238 /* We enforce a maximum number of query restarts. This is primarily a
1239 * cheap way to prevent CNAME loops. */
1240 if(iq->query_restart_count > MAX_RESTART_COUNT) {
1241 verbose(VERB_QUERY, "request has exceeded the maximum number"
1242 " of query restarts with %d", iq->query_restart_count);
1243 errinf(qstate, "request has exceeded the maximum number "
1244 "restarts (eg. indirections)");
1245 if(iq->qchase.qname)
1246 errinf_dname(qstate, "stop at", iq->qchase.qname);
1247 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1250 /* We enforce a maximum recursion/dependency depth -- in general,
1251 * this is unnecessary for dependency loops (although it will
1252 * catch those), but it provides a sensible limit to the amount
1253 * of work required to answer a given query. */
1254 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
1255 if(iq->depth > ie->max_dependency_depth) {
1256 verbose(VERB_QUERY, "request has exceeded the maximum "
1257 "dependency depth with depth of %d", iq->depth);
1258 errinf(qstate, "request has exceeded the maximum dependency "
1259 "depth (eg. nameserver lookup recursion)");
1260 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1263 /* If the request is qclass=ANY, setup to generate each class */
1264 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
1265 iq->qchase.qclass = 0;
1266 return next_state(iq, COLLECT_CLASS_STATE);
1270 * If we are restricted by a forward-zone or a stub-zone, we
1271 * can't re-fetch glue for this delegation point.
1272 * we won’t try to re-fetch glue if the iq->dp is null.
1274 if (iq->refetch_glue &&
1276 !can_have_last_resort(qstate->env, iq->dp->name,
1277 iq->dp->namelen, iq->qchase.qclass, NULL)) {
1278 iq->refetch_glue = 0;
1281 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */
1283 /* This either results in a query restart (CNAME cache response), a
1284 * terminating response (ANSWER), or a cache miss (null). */
1286 if (iter_stub_fwd_no_cache(qstate, &iq->qchase)) {
1287 /* Asked to not query cache. */
1288 verbose(VERB_ALGO, "no-cache set, going to the network");
1289 qstate->no_cache_lookup = 1;
1290 qstate->no_cache_store = 1;
1292 } else if(qstate->blacklist) {
1293 /* if cache, or anything else, was blacklisted then
1294 * getting older results from cache is a bad idea, no cache */
1295 verbose(VERB_ALGO, "cache blacklisted, going to the network");
1297 } else if(!qstate->no_cache_lookup) {
1298 msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
1299 iq->qchase.qname_len, iq->qchase.qtype,
1300 iq->qchase.qclass, qstate->query_flags,
1301 qstate->region, qstate->env->scratch, 0);
1302 if(!msg && qstate->env->neg_cache &&
1303 iter_qname_indicates_dnssec(qstate->env, &iq->qchase)) {
1304 /* lookup in negative cache; may result in
1305 * NOERROR/NODATA or NXDOMAIN answers that need validation */
1306 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
1307 qstate->region, qstate->env->rrset_cache,
1308 qstate->env->scratch_buffer,
1309 *qstate->env->now, 1/*add SOA*/, NULL,
1312 /* item taken from cache does not match our query name, thus
1313 * security needs to be re-examined later */
1314 if(msg && query_dname_compare(qstate->qinfo.qname,
1315 iq->qchase.qname) != 0)
1316 msg->rep->security = sec_status_unchecked;
1319 /* handle positive cache response */
1320 enum response_type type = response_type_from_cache(msg,
1322 if(verbosity >= VERB_ALGO) {
1323 log_dns_msg("msg from cache lookup", &msg->qinfo,
1325 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
1327 (int)msg->rep->prefetch_ttl);
1330 if(type == RESPONSE_TYPE_CNAME) {
1333 verbose(VERB_ALGO, "returning CNAME response from "
1335 if(!handle_cname_response(qstate, iq, msg,
1337 errinf(qstate, "failed to prepend CNAME "
1338 "components, malloc failure");
1339 return error_response(qstate, id,
1340 LDNS_RCODE_SERVFAIL);
1342 iq->qchase.qname = sname;
1343 iq->qchase.qname_len = slen;
1344 /* This *is* a query restart, even if it is a cheap
1347 iq->refetch_glue = 0;
1348 iq->query_restart_count++;
1350 iq->dp_target_count = 0;
1351 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1352 if(qstate->env->cfg->qname_minimisation)
1353 iq->minimisation_state = INIT_MINIMISE_STATE;
1354 return next_state(iq, INIT_REQUEST_STATE);
1357 /* if from cache, NULL, else insert 'cache IP' len=0 */
1358 if(qstate->reply_origin)
1359 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1360 if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_SERVFAIL)
1361 errinf(qstate, "SERVFAIL in cache");
1362 /* it is an answer, response, to final state */
1363 verbose(VERB_ALGO, "returning answer from cache.");
1365 return final_state(iq);
1368 /* attempt to forward the request */
1369 if(forward_request(qstate, iq))
1372 log_err("alloc failure for forward dp");
1373 errinf(qstate, "malloc failure for forward zone");
1374 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1376 iq->refetch_glue = 0;
1377 iq->minimisation_state = DONOT_MINIMISE_STATE;
1378 /* the request has been forwarded.
1379 * forwarded requests need to be immediately sent to the
1380 * next state, QUERYTARGETS. */
1381 return next_state(iq, QUERYTARGETS_STATE);
1384 /* Resolver Algorithm Step 2 -- find the "best" servers. */
1386 /* first, adjust for DS queries. To avoid the grandparent problem,
1387 * we just look for the closest set of server to the parent of qname.
1388 * When re-fetching glue we also need to ask the parent.
1390 if(iq->refetch_glue) {
1392 log_err("internal or malloc fail: no dp for refetch");
1393 errinf(qstate, "malloc failure, for delegation info");
1394 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1396 delname = iq->dp->name;
1397 delnamelen = iq->dp->namelen;
1399 delname = iq->qchase.qname;
1400 delnamelen = iq->qchase.qname_len;
1402 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
1403 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway
1404 && can_have_last_resort(qstate->env, delname, delnamelen, iq->qchase.qclass, NULL))) {
1405 /* remove first label from delname, root goes to hints,
1406 * but only to fetch glue, not for qtype=DS. */
1407 /* also when prefetching an NS record, fetch it again from
1408 * its parent, just as if it expired, so that you do not
1409 * get stuck on an older nameserver that gives old NSrecords */
1410 if(dname_is_root(delname) && (iq->refetch_glue ||
1411 (iq->qchase.qtype == LDNS_RR_TYPE_NS &&
1412 qstate->prefetch_leeway)))
1413 delname = NULL; /* go to root priming */
1414 else dname_remove_label(&delname, &delnamelen);
1416 /* delname is the name to lookup a delegation for. If NULL rootprime */
1419 /* Lookup the delegation in the cache. If null, then the
1420 * cache needs to be primed for the qclass. */
1422 iq->dp = dns_cache_find_delegation(qstate->env, delname,
1423 delnamelen, iq->qchase.qtype, iq->qchase.qclass,
1424 qstate->region, &iq->deleg_msg,
1425 *qstate->env->now+qstate->prefetch_leeway);
1428 /* If the cache has returned nothing, then we have a
1429 * root priming situation. */
1430 if(iq->dp == NULL) {
1432 /* if under auth zone, no prime needed */
1433 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen))
1434 return error_response(qstate, id,
1435 LDNS_RCODE_SERVFAIL);
1436 if(iq->dp) /* use auth zone dp */
1437 return next_state(iq, INIT_REQUEST_2_STATE);
1438 /* if there is a stub, then no root prime needed */
1439 r = prime_stub(qstate, iq, id, delname,
1442 break; /* got noprime-stub-zone, continue */
1444 return 0; /* stub prime request made */
1445 if(forwards_lookup_root(qstate->env->fwds,
1446 iq->qchase.qclass)) {
1447 /* forward zone root, no root prime needed */
1448 /* fill in some dp - safety belt */
1449 iq->dp = hints_lookup_root(qstate->env->hints,
1452 log_err("internal error: no hints dp");
1453 errinf(qstate, "no hints for this class");
1454 return error_response(qstate, id,
1455 LDNS_RCODE_SERVFAIL);
1457 iq->dp = delegpt_copy(iq->dp, qstate->region);
1459 log_err("out of memory in safety belt");
1460 errinf(qstate, "malloc failure, in safety belt");
1461 return error_response(qstate, id,
1462 LDNS_RCODE_SERVFAIL);
1464 return next_state(iq, INIT_REQUEST_2_STATE);
1466 /* Note that the result of this will set a new
1467 * DelegationPoint based on the result of priming. */
1468 if(!prime_root(qstate, iq, id, iq->qchase.qclass))
1469 return error_response(qstate, id,
1470 LDNS_RCODE_REFUSED);
1472 /* priming creates and sends a subordinate query, with
1473 * this query as the parent. So further processing for
1474 * this event will stop until reactivated by the
1475 * results of priming. */
1478 if(!iq->ratelimit_ok && qstate->prefetch_leeway)
1479 iq->ratelimit_ok = 1; /* allow prefetches, this keeps
1480 otherwise valid data in the cache */
1481 if(!iq->ratelimit_ok && infra_ratelimit_exceeded(
1482 qstate->env->infra_cache, iq->dp->name,
1483 iq->dp->namelen, *qstate->env->now)) {
1484 /* and increment the rate, so that the rate for time
1485 * now will also exceed the rate, keeping cache fresh */
1486 (void)infra_ratelimit_inc(qstate->env->infra_cache,
1487 iq->dp->name, iq->dp->namelen,
1488 *qstate->env->now, &qstate->qinfo,
1490 /* see if we are passed through with slip factor */
1491 if(qstate->env->cfg->ratelimit_factor != 0 &&
1492 ub_random_max(qstate->env->rnd,
1493 qstate->env->cfg->ratelimit_factor) == 1) {
1494 iq->ratelimit_ok = 1;
1495 log_nametypeclass(VERB_ALGO, "ratelimit allowed through for "
1496 "delegation point", iq->dp->name,
1497 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
1499 lock_basic_lock(&ie->queries_ratelimit_lock);
1500 ie->num_queries_ratelimited++;
1501 lock_basic_unlock(&ie->queries_ratelimit_lock);
1502 log_nametypeclass(VERB_ALGO, "ratelimit exceeded with "
1503 "delegation point", iq->dp->name,
1504 LDNS_RR_TYPE_NS, LDNS_RR_CLASS_IN);
1505 qstate->was_ratelimited = 1;
1506 errinf(qstate, "query was ratelimited");
1507 errinf_dname(qstate, "for zone", iq->dp->name);
1508 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1512 /* see if this dp not useless.
1514 * o all NS items are required glue.
1515 * or the query is for NS item that is required glue.
1516 * o no addresses are provided.
1518 * Instead, go up one level, and try to get even further
1519 * If the root was useless, use safety belt information.
1520 * Only check cache returns, because replies for servers
1521 * could be useless but lead to loops (bumping into the
1522 * same server reply) if useless-checked.
1524 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
1526 struct delegpt* retdp = NULL;
1527 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, iq->qchase.qclass, &retdp)) {
1529 verbose(VERB_QUERY, "cache has stub "
1530 "or fwd but no addresses, "
1531 "fallback to config");
1532 iq->dp = delegpt_copy(retdp,
1535 log_err("out of memory in "
1536 "stub/fwd fallback");
1537 errinf(qstate, "malloc failure, for fallback to config");
1538 return error_response(qstate,
1539 id, LDNS_RCODE_SERVFAIL);
1543 verbose(VERB_ALGO, "useless dp "
1544 "but cannot go up, servfail");
1545 delegpt_log(VERB_ALGO, iq->dp);
1546 errinf(qstate, "no useful nameservers, "
1547 "and cannot go up");
1548 errinf_dname(qstate, "for zone", iq->dp->name);
1549 return error_response(qstate, id,
1550 LDNS_RCODE_SERVFAIL);
1552 if(dname_is_root(iq->dp->name)) {
1553 /* use safety belt */
1554 verbose(VERB_QUERY, "Cache has root NS but "
1555 "no addresses. Fallback to the safety belt.");
1556 iq->dp = hints_lookup_root(qstate->env->hints,
1558 /* note deleg_msg is from previous lookup,
1559 * but RD is on, so it is not used */
1561 log_err("internal error: no hints dp");
1562 return error_response(qstate, id,
1563 LDNS_RCODE_REFUSED);
1565 iq->dp = delegpt_copy(iq->dp, qstate->region);
1567 log_err("out of memory in safety belt");
1568 errinf(qstate, "malloc failure, in safety belt, for root");
1569 return error_response(qstate, id,
1570 LDNS_RCODE_SERVFAIL);
1575 "cache delegation was useless:");
1576 delegpt_log(VERB_ALGO, iq->dp);
1578 delname = iq->dp->name;
1579 delnamelen = iq->dp->namelen;
1580 dname_remove_label(&delname, &delnamelen);
1585 verbose(VERB_ALGO, "cache delegation returns delegpt");
1586 delegpt_log(VERB_ALGO, iq->dp);
1588 /* Otherwise, set the current delegation point and move on to the
1590 return next_state(iq, INIT_REQUEST_2_STATE);
1594 * Process the second part of the initial request handling. This state
1595 * basically exists so that queries that generate root priming events have
1596 * the same init processing as ones that do not. Request events that reach
1597 * this state must have a valid currentDelegationPoint set.
1599 * This part is primarily handling stub zone priming. Events that reach this
1600 * state must have a current delegation point.
1602 * @param qstate: query state.
1603 * @param iq: iterator query state.
1604 * @param id: module id.
1605 * @return true if the event needs more request processing immediately,
1609 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
1614 log_query_info(VERB_QUERY, "resolving (init part 2): ",
1617 delname = iq->qchase.qname;
1618 delnamelen = iq->qchase.qname_len;
1619 if(iq->refetch_glue) {
1620 struct iter_hints_stub* stub;
1622 log_err("internal or malloc fail: no dp for refetch");
1623 errinf(qstate, "malloc failure, no delegation info");
1624 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1626 /* Do not send queries above stub, do not set delname to dp if
1627 * this is above stub without stub-first. */
1628 stub = hints_lookup_stub(
1629 qstate->env->hints, iq->qchase.qname, iq->qchase.qclass,
1631 if(!stub || !stub->dp->has_parent_side_NS ||
1632 dname_subdomain_c(iq->dp->name, stub->dp->name)) {
1633 delname = iq->dp->name;
1634 delnamelen = iq->dp->namelen;
1637 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
1638 if(!dname_is_root(delname))
1639 dname_remove_label(&delname, &delnamelen);
1640 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
1643 /* see if we have an auth zone to answer from, improves dp from cache
1644 * (if any dp from cache) with auth zone dp, if that is lower */
1645 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen))
1646 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1648 /* Check to see if we need to prime a stub zone. */
1649 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
1650 /* A priming sub request was made */
1654 /* most events just get forwarded to the next state. */
1655 return next_state(iq, INIT_REQUEST_3_STATE);
1659 * Process the third part of the initial request handling. This state exists
1660 * as a separate state so that queries that generate stub priming events
1661 * will get the tail end of the init process but not repeat the stub priming
1664 * @param qstate: query state.
1665 * @param iq: iterator query state.
1666 * @param id: module id.
1667 * @return true, advancing the event to the QUERYTARGETS_STATE.
1670 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
1673 log_query_info(VERB_QUERY, "resolving (init part 3): ",
1675 /* if the cache reply dp equals a validation anchor or msg has DS,
1676 * then DNSSEC RRSIGs are expected in the reply */
1677 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
1678 iq->deleg_msg, iq->qchase.qclass);
1680 /* If the RD flag wasn't set, then we just finish with the
1681 * cached referral as the response. */
1682 if(!(qstate->query_flags & BIT_RD) && iq->deleg_msg) {
1683 iq->response = iq->deleg_msg;
1684 if(verbosity >= VERB_ALGO && iq->response)
1685 log_dns_msg("no RD requested, using delegation msg",
1686 &iq->response->qinfo, iq->response->rep);
1687 if(qstate->reply_origin)
1688 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1689 return final_state(iq);
1691 /* After this point, unset the RD flag -- this query is going to
1692 * be sent to an auth. server. */
1693 iq->chase_flags &= ~BIT_RD;
1695 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */
1696 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
1697 !(qstate->query_flags&BIT_CD)) {
1698 generate_dnskey_prefetch(qstate, iq, id);
1699 fptr_ok(fptr_whitelist_modenv_detach_subs(
1700 qstate->env->detach_subs));
1701 (*qstate->env->detach_subs)(qstate);
1704 /* Jump to the next state. */
1705 return next_state(iq, QUERYTARGETS_STATE);
1709 * Given a basic query, generate a parent-side "target" query.
1710 * These are subordinate queries for missing delegation point target addresses,
1711 * for which only the parent of the delegation provides correct IP addresses.
1713 * @param qstate: query state.
1714 * @param iq: iterator query state.
1715 * @param id: module id.
1716 * @param name: target qname.
1717 * @param namelen: target qname length.
1718 * @param qtype: target qtype (either A or AAAA).
1719 * @param qclass: target qclass.
1720 * @return true on success, false on failure.
1723 generate_parentside_target_query(struct module_qstate* qstate,
1724 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen,
1725 uint16_t qtype, uint16_t qclass)
1727 struct module_qstate* subq;
1728 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1729 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0))
1732 struct iter_qstate* subiq =
1733 (struct iter_qstate*)subq->minfo[id];
1734 /* blacklist the cache - we want to fetch parent stuff */
1735 sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
1736 subiq->query_for_pside_glue = 1;
1737 if(dname_subdomain_c(name, iq->dp->name)) {
1738 subiq->dp = delegpt_copy(iq->dp, subq->region);
1739 subiq->dnssec_expected = iter_indicates_dnssec(
1740 qstate->env, subiq->dp, NULL,
1741 subq->qinfo.qclass);
1742 subiq->refetch_glue = 1;
1744 subiq->dp = dns_cache_find_delegation(qstate->env,
1745 name, namelen, qtype, qclass, subq->region,
1747 *qstate->env->now+subq->prefetch_leeway);
1748 /* if no dp, then it's from root, refetch unneeded */
1750 subiq->dnssec_expected = iter_indicates_dnssec(
1751 qstate->env, subiq->dp, NULL,
1752 subq->qinfo.qclass);
1753 subiq->refetch_glue = 1;
1757 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
1762 * Given a basic query, generate a "target" query. These are subordinate
1763 * queries for missing delegation point target addresses.
1765 * @param qstate: query state.
1766 * @param iq: iterator query state.
1767 * @param id: module id.
1768 * @param name: target qname.
1769 * @param namelen: target qname length.
1770 * @param qtype: target qtype (either A or AAAA).
1771 * @param qclass: target qclass.
1772 * @return true on success, false on failure.
1775 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
1776 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
1778 struct module_qstate* subq;
1779 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1780 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0))
1782 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
1787 * Given an event at a certain state, generate zero or more target queries
1788 * for it's current delegation point.
1790 * @param qstate: query state.
1791 * @param iq: iterator query state.
1792 * @param ie: iterator shared global environment.
1793 * @param id: module id.
1794 * @param maxtargets: The maximum number of targets to query for.
1795 * if it is negative, there is no maximum number of targets.
1796 * @param num: returns the number of queries generated and processed,
1797 * which may be zero if there were no missing targets.
1798 * @return false on error.
1801 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
1802 struct iter_env* ie, int id, int maxtargets, int* num)
1804 int query_count = 0;
1805 struct delegpt_ns* ns;
1809 if(iq->depth == ie->max_dependency_depth)
1811 if(iq->depth > 0 && iq->target_count &&
1812 iq->target_count[1] > MAX_TARGET_COUNT) {
1813 char s[LDNS_MAX_DOMAINLEN+1];
1814 dname_str(qstate->qinfo.qname, s);
1815 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1816 "number of glue fetches %d", s, iq->target_count[1]);
1819 if(iq->dp_target_count > MAX_DP_TARGET_COUNT) {
1820 char s[LDNS_MAX_DOMAINLEN+1];
1821 dname_str(qstate->qinfo.qname, s);
1822 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1823 "number of glue fetches %d to a single delegation point",
1824 s, iq->dp_target_count);
1828 iter_mark_cycle_targets(qstate, iq->dp);
1829 missing = (int)delegpt_count_missing_targets(iq->dp);
1830 log_assert(maxtargets != 0); /* that would not be useful */
1832 /* Generate target requests. Basically, any missing targets
1833 * are queried for here, regardless if it is necessary to do
1834 * so to continue processing. */
1835 if(maxtargets < 0 || maxtargets > missing)
1837 else toget = maxtargets;
1842 /* select 'toget' items from the total of 'missing' items */
1843 log_assert(toget <= missing);
1845 /* loop over missing targets */
1846 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1850 /* randomly select this item with probability toget/missing */
1851 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
1852 /* do not select this one, next; select toget number
1853 * of items from a list one less in size */
1858 if(ie->supports_ipv6 && !ns->got6) {
1859 /* Send the AAAA request. */
1860 if(!generate_target_query(qstate, iq, id,
1861 ns->name, ns->namelen,
1862 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
1865 qstate->ext_state[id] = module_wait_subquery;
1870 /* Send the A request. */
1871 if(ie->supports_ipv4 && !ns->got4) {
1872 if(!generate_target_query(qstate, iq, id,
1873 ns->name, ns->namelen,
1874 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
1877 qstate->ext_state[id] = module_wait_subquery;
1883 /* mark this target as in progress. */
1892 qstate->ext_state[id] = module_wait_subquery;
1898 * Called by processQueryTargets when it would like extra targets to query
1899 * but it seems to be out of options. At last resort some less appealing
1900 * options are explored. If there are no more options, the result is SERVFAIL
1902 * @param qstate: query state.
1903 * @param iq: iterator query state.
1904 * @param ie: iterator shared global environment.
1905 * @param id: module id.
1906 * @return true if the event requires more request processing immediately,
1910 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
1911 struct iter_env* ie, int id)
1913 struct delegpt_ns* ns;
1914 int query_count = 0;
1915 verbose(VERB_ALGO, "No more query targets, attempting last resort");
1918 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen,
1919 iq->qchase.qclass, NULL)) {
1920 /* fail -- no more targets, no more hope of targets, no hope
1922 errinf(qstate, "all the configured stub or forward servers failed,");
1923 errinf_dname(qstate, "at zone", iq->dp->name);
1924 verbose(VERB_QUERY, "configured stub or forward servers failed -- returning SERVFAIL");
1925 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1927 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
1928 struct delegpt* p = hints_lookup_root(qstate->env->hints,
1931 struct delegpt_addr* a;
1932 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1933 for(ns = p->nslist; ns; ns=ns->next) {
1934 (void)delegpt_add_ns(iq->dp, qstate->region,
1935 ns->name, ns->lame);
1937 for(a = p->target_list; a; a=a->next_target) {
1938 (void)delegpt_add_addr(iq->dp, qstate->region,
1939 &a->addr, a->addrlen, a->bogus,
1940 a->lame, a->tls_auth_name, NULL);
1943 iq->dp->has_parent_side_NS = 1;
1944 } else if(!iq->dp->has_parent_side_NS) {
1945 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
1946 qstate->region, &qstate->qinfo)
1947 || !iq->dp->has_parent_side_NS) {
1948 /* if: malloc failure in lookup go up to try */
1949 /* if: no parent NS in cache - go up one level */
1950 verbose(VERB_ALGO, "try to grab parent NS");
1951 iq->store_parent_NS = iq->dp;
1952 iq->chase_flags &= ~BIT_RD; /* go to authorities */
1953 iq->deleg_msg = NULL;
1954 iq->refetch_glue = 1;
1955 iq->query_restart_count++;
1957 iq->dp_target_count = 0;
1958 if(qstate->env->cfg->qname_minimisation)
1959 iq->minimisation_state = INIT_MINIMISE_STATE;
1960 return next_state(iq, INIT_REQUEST_STATE);
1963 /* see if that makes new names available */
1964 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
1965 qstate->region, iq->dp))
1966 log_err("out of memory in cache_fill_missing");
1967 if(iq->dp->usable_list) {
1968 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
1969 return next_state(iq, QUERYTARGETS_STATE);
1971 /* try to fill out parent glue from cache */
1972 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
1973 qstate->region, &qstate->qinfo)) {
1974 /* got parent stuff from cache, see if we can continue */
1975 verbose(VERB_ALGO, "try parent-side glue from cache");
1976 return next_state(iq, QUERYTARGETS_STATE);
1978 /* query for an extra name added by the parent-NS record */
1979 if(delegpt_count_missing_targets(iq->dp) > 0) {
1981 verbose(VERB_ALGO, "try parent-side target name");
1982 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
1983 errinf(qstate, "could not fetch nameserver");
1984 errinf_dname(qstate, "at zone", iq->dp->name);
1985 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1987 iq->num_target_queries += qs;
1988 target_count_increase(iq, qs);
1990 qstate->ext_state[id] = module_wait_subquery;
1991 return 0; /* and wait for them */
1994 if(iq->depth == ie->max_dependency_depth) {
1995 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
1996 errinf(qstate, "cannot fetch more nameservers because at max dependency depth");
1997 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
1999 if(iq->depth > 0 && iq->target_count &&
2000 iq->target_count[1] > MAX_TARGET_COUNT) {
2001 char s[LDNS_MAX_DOMAINLEN+1];
2002 dname_str(qstate->qinfo.qname, s);
2003 verbose(VERB_QUERY, "request %s has exceeded the maximum "
2004 "number of glue fetches %d", s, iq->target_count[1]);
2005 errinf(qstate, "exceeded the maximum number of glue fetches");
2006 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2008 /* mark cycle targets for parent-side lookups */
2009 iter_mark_pside_cycle_targets(qstate, iq->dp);
2010 /* see if we can issue queries to get nameserver addresses */
2011 /* this lookup is not randomized, but sequential. */
2012 for(ns = iq->dp->nslist; ns; ns = ns->next) {
2013 /* if this nameserver is at a delegation point, but that
2014 * delegation point is a stub and we cannot go higher, skip*/
2015 if( ((ie->supports_ipv6 && !ns->done_pside6) ||
2016 (ie->supports_ipv4 && !ns->done_pside4)) &&
2017 !can_have_last_resort(qstate->env, ns->name, ns->namelen,
2018 iq->qchase.qclass, NULL)) {
2019 log_nametypeclass(VERB_ALGO, "cannot pside lookup ns "
2020 "because it is also a stub/forward,",
2021 ns->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
2022 if(ie->supports_ipv6) ns->done_pside6 = 1;
2023 if(ie->supports_ipv4) ns->done_pside4 = 1;
2026 /* query for parent-side A and AAAA for nameservers */
2027 if(ie->supports_ipv6 && !ns->done_pside6) {
2028 /* Send the AAAA request. */
2029 if(!generate_parentside_target_query(qstate, iq, id,
2030 ns->name, ns->namelen,
2031 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
2032 errinf_dname(qstate, "could not generate nameserver AAAA lookup for", ns->name);
2033 return error_response(qstate, id,
2034 LDNS_RCODE_SERVFAIL);
2036 ns->done_pside6 = 1;
2039 if(ie->supports_ipv4 && !ns->done_pside4) {
2040 /* Send the A request. */
2041 if(!generate_parentside_target_query(qstate, iq, id,
2042 ns->name, ns->namelen,
2043 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
2044 errinf_dname(qstate, "could not generate nameserver A lookup for", ns->name);
2045 return error_response(qstate, id,
2046 LDNS_RCODE_SERVFAIL);
2048 ns->done_pside4 = 1;
2051 if(query_count != 0) { /* suspend to await results */
2052 verbose(VERB_ALGO, "try parent-side glue lookup");
2053 iq->num_target_queries += query_count;
2054 target_count_increase(iq, query_count);
2055 qstate->ext_state[id] = module_wait_subquery;
2060 /* if this was a parent-side glue query itself, then store that
2061 * failure in cache. */
2062 if(!qstate->no_cache_store && iq->query_for_pside_glue
2064 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
2065 iq->deleg_msg?iq->deleg_msg->rep:
2066 (iq->response?iq->response->rep:NULL));
2068 errinf(qstate, "all servers for this domain failed,");
2069 errinf_dname(qstate, "at zone", iq->dp->name);
2070 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
2071 /* fail -- no more targets, no more hope of targets, no hope
2073 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2077 * Try to find the NS record set that will resolve a qtype DS query. Due
2078 * to grandparent/grandchild reasons we did not get a proper lookup right
2079 * away. We need to create type NS queries until we get the right parent
2080 * for this lookup. We remove labels from the query to find the right point.
2081 * If we end up at the old dp name, then there is no solution.
2083 * @param qstate: query state.
2084 * @param iq: iterator query state.
2085 * @param id: module id.
2086 * @return true if the event requires more immediate processing, false if
2087 * not. This is generally only true when forwarding the request to
2088 * the final state (i.e., on answer).
2091 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
2093 struct module_qstate* subq = NULL;
2094 verbose(VERB_ALGO, "processDSNSFind");
2096 if(!iq->dsns_point) {
2098 iq->dsns_point = iq->qchase.qname;
2099 iq->dsns_point_len = iq->qchase.qname_len;
2101 /* robustcheck for internal error: we are not underneath the dp */
2102 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
2103 errinf_dname(qstate, "for DS query parent-child nameserver search the query is not under the zone", iq->dp->name);
2104 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2107 /* go up one (more) step, until we hit the dp, if so, end */
2108 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
2109 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
2110 /* there was no inbetween nameserver, use the old delegation
2111 * point again. And this time, because dsns_point is nonNULL
2112 * we are going to accept the (bad) result */
2113 iq->state = QUERYTARGETS_STATE;
2116 iq->state = DSNS_FIND_STATE;
2118 /* spawn NS lookup (validation not needed, this is for DS lookup) */
2119 log_nametypeclass(VERB_ALGO, "fetch nameservers",
2120 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
2121 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
2122 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
2123 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) {
2124 errinf_dname(qstate, "for DS query parent-child nameserver search, could not generate NS lookup for", iq->dsns_point);
2125 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2132 * This is the request event state where the request will be sent to one of
2133 * its current query targets. This state also handles issuing target lookup
2134 * queries for missing target IP addresses. Queries typically iterate on
2135 * this state, both when they are just trying different targets for a given
2136 * delegation point, and when they change delegation points. This state
2137 * roughly corresponds to RFC 1034 algorithm steps 3 and 4.
2139 * @param qstate: query state.
2140 * @param iq: iterator query state.
2141 * @param ie: iterator shared global environment.
2142 * @param id: module id.
2143 * @return true if the event requires more request processing immediately,
2144 * false if not. This state only returns true when it is generating
2145 * a SERVFAIL response because the query has hit a dead end.
2148 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
2149 struct iter_env* ie, int id)
2152 struct delegpt_addr* target;
2153 struct outbound_entry* outq;
2154 int auth_fallback = 0;
2155 uint8_t* qout_orig = NULL;
2156 size_t qout_orig_len = 0;
2158 /* NOTE: a request will encounter this state for each target it
2159 * needs to send a query to. That is, at least one per referral,
2160 * more if some targets timeout or return throwaway answers. */
2162 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
2163 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
2164 "currentqueries %d sentcount %d", iq->num_target_queries,
2165 iq->num_current_queries, iq->sent_count);
2167 /* Make sure that we haven't run away */
2168 /* FIXME: is this check even necessary? */
2169 if(iq->referral_count > MAX_REFERRAL_COUNT) {
2170 verbose(VERB_QUERY, "request has exceeded the maximum "
2171 "number of referrrals with %d", iq->referral_count);
2172 errinf(qstate, "exceeded the maximum of referrals");
2173 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2175 if(iq->sent_count > MAX_SENT_COUNT) {
2176 verbose(VERB_QUERY, "request has exceeded the maximum "
2177 "number of sends with %d", iq->sent_count);
2178 errinf(qstate, "exceeded the maximum number of sends");
2179 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2181 if(iq->target_count && iq->target_count[2] > MAX_TARGET_NX) {
2182 verbose(VERB_QUERY, "request has exceeded the maximum "
2183 " number of nxdomain nameserver lookups with %d",
2184 iq->target_count[2]);
2185 errinf(qstate, "exceeded the maximum nameserver nxdomains");
2186 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2189 /* Make sure we have a delegation point, otherwise priming failed
2190 * or another failure occurred */
2192 verbose(VERB_QUERY, "Failed to get a delegation, giving up");
2193 errinf(qstate, "failed to get a delegation (eg. prime failure)");
2194 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2196 if(!ie->supports_ipv6)
2197 delegpt_no_ipv6(iq->dp);
2198 if(!ie->supports_ipv4)
2199 delegpt_no_ipv4(iq->dp);
2200 delegpt_log(VERB_ALGO, iq->dp);
2202 if(iq->num_current_queries>0) {
2203 /* already busy answering a query, this restart is because
2204 * more delegpt addrs became available, wait for existing
2206 verbose(VERB_ALGO, "woke up, but wait for outstanding query");
2207 qstate->ext_state[id] = module_wait_reply;
2211 if(iq->minimisation_state == INIT_MINIMISE_STATE
2212 && !(iq->chase_flags & BIT_RD)) {
2213 /* (Re)set qinfo_out to (new) delegation point, except when
2214 * qinfo_out is already a subdomain of dp. This happens when
2215 * increasing by more than one label at once (QNAMEs with more
2216 * than MAX_MINIMISE_COUNT labels). */
2217 if(!(iq->qinfo_out.qname_len
2218 && dname_subdomain_c(iq->qchase.qname,
2219 iq->qinfo_out.qname)
2220 && dname_subdomain_c(iq->qinfo_out.qname,
2222 iq->qinfo_out.qname = iq->dp->name;
2223 iq->qinfo_out.qname_len = iq->dp->namelen;
2224 iq->qinfo_out.qtype = LDNS_RR_TYPE_A;
2225 iq->qinfo_out.qclass = iq->qchase.qclass;
2226 iq->qinfo_out.local_alias = NULL;
2227 iq->minimise_count = 0;
2230 iq->minimisation_state = MINIMISE_STATE;
2232 if(iq->minimisation_state == MINIMISE_STATE) {
2233 int qchaselabs = dname_count_labels(iq->qchase.qname);
2234 int labdiff = qchaselabs -
2235 dname_count_labels(iq->qinfo_out.qname);
2237 qout_orig = iq->qinfo_out.qname;
2238 qout_orig_len = iq->qinfo_out.qname_len;
2239 iq->qinfo_out.qname = iq->qchase.qname;
2240 iq->qinfo_out.qname_len = iq->qchase.qname_len;
2241 iq->minimise_count++;
2242 iq->timeout_count = 0;
2244 iter_dec_attempts(iq->dp, 1);
2246 /* Limit number of iterations for QNAMEs with more
2247 * than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB
2248 * labels of QNAME always individually.
2250 if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 &&
2251 iq->minimise_count > MINIMISE_ONE_LAB) {
2252 if(iq->minimise_count < MAX_MINIMISE_COUNT) {
2253 int multilabs = qchaselabs - 1 -
2255 int extralabs = multilabs /
2256 MINIMISE_MULTIPLE_LABS;
2258 if (MAX_MINIMISE_COUNT - iq->minimise_count >=
2259 multilabs % MINIMISE_MULTIPLE_LABS)
2260 /* Default behaviour is to add 1 label
2261 * every iteration. Therefore, decrement
2262 * the extralabs by 1 */
2264 if (extralabs < labdiff)
2265 labdiff -= extralabs;
2269 /* Last minimised iteration, send all labels with
2276 verbose(VERB_QUERY, "removing %d labels", labdiff-1);
2277 dname_remove_labels(&iq->qinfo_out.qname,
2278 &iq->qinfo_out.qname_len,
2281 if(labdiff < 1 || (labdiff < 2
2282 && (iq->qchase.qtype == LDNS_RR_TYPE_DS
2283 || iq->qchase.qtype == LDNS_RR_TYPE_A)))
2284 /* Stop minimising this query, resolve "as usual" */
2285 iq->minimisation_state = DONOT_MINIMISE_STATE;
2286 else if(!qstate->no_cache_lookup) {
2287 struct dns_msg* msg = dns_cache_lookup(qstate->env,
2288 iq->qinfo_out.qname, iq->qinfo_out.qname_len,
2289 iq->qinfo_out.qtype, iq->qinfo_out.qclass,
2290 qstate->query_flags, qstate->region,
2291 qstate->env->scratch, 0);
2292 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2294 /* no need to send query if it is already
2295 * cached as NOERROR */
2297 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2298 LDNS_RCODE_NXDOMAIN &&
2299 qstate->env->need_to_validate &&
2300 qstate->env->cfg->harden_below_nxdomain) {
2301 if(msg->rep->security == sec_status_secure) {
2303 return final_state(iq);
2305 if(msg->rep->security == sec_status_unchecked) {
2306 struct module_qstate* subq = NULL;
2307 if(!generate_sub_request(
2308 iq->qinfo_out.qname,
2309 iq->qinfo_out.qname_len,
2310 iq->qinfo_out.qtype,
2311 iq->qinfo_out.qclass,
2314 FINISHED_STATE, &subq, 1, 1))
2316 "could not validate NXDOMAIN "
2320 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2321 LDNS_RCODE_NXDOMAIN) {
2322 /* return and add a label in the next
2323 * minimisation iteration.
2329 if(iq->minimisation_state == SKIP_MINIMISE_STATE) {
2330 if(iq->timeout_count < MAX_MINIMISE_TIMEOUT_COUNT)
2331 /* Do not increment qname, continue incrementing next
2333 iq->minimisation_state = MINIMISE_STATE;
2334 else if(!qstate->env->cfg->qname_minimisation_strict)
2335 /* Too many time-outs detected for this QNAME and QTYPE.
2336 * We give up, disable QNAME minimisation. */
2337 iq->minimisation_state = DONOT_MINIMISE_STATE;
2339 if(iq->minimisation_state == DONOT_MINIMISE_STATE)
2340 iq->qinfo_out = iq->qchase;
2342 /* now find an answer to this query */
2343 /* see if authority zones have an answer */
2344 /* now we know the dp, we can check the auth zone for locally hosted
2346 if(!iq->auth_zone_avoid && qstate->blacklist) {
2347 if(auth_zones_can_fallback(qstate->env->auth_zones,
2348 iq->dp->name, iq->dp->namelen, iq->qinfo_out.qclass)) {
2349 /* if cache is blacklisted and this zone allows us
2350 * to fallback to the internet, then do so, and
2351 * fetch results from the internet servers */
2352 iq->auth_zone_avoid = 1;
2355 if(iq->auth_zone_avoid) {
2356 iq->auth_zone_avoid = 0;
2358 } else if(auth_zones_lookup(qstate->env->auth_zones, &iq->qinfo_out,
2359 qstate->region, &iq->response, &auth_fallback, iq->dp->name,
2361 /* use this as a response to be processed by the iterator */
2362 if(verbosity >= VERB_ALGO) {
2363 log_dns_msg("msg from auth zone",
2364 &iq->response->qinfo, iq->response->rep);
2366 if((iq->chase_flags&BIT_RD) && !(iq->response->rep->flags&BIT_AA)) {
2367 verbose(VERB_ALGO, "forwarder, ignoring referral from auth zone");
2369 lock_rw_wrlock(&qstate->env->auth_zones->lock);
2370 qstate->env->auth_zones->num_query_up++;
2371 lock_rw_unlock(&qstate->env->auth_zones->lock);
2372 iq->num_current_queries++;
2373 iq->chase_to_rd = 0;
2374 iq->dnssec_lame_query = 0;
2375 iq->auth_zone_response = 1;
2376 return next_state(iq, QUERY_RESP_STATE);
2379 iq->auth_zone_response = 0;
2380 if(auth_fallback == 0) {
2381 /* like we got servfail from the auth zone lookup, and
2382 * no internet fallback */
2383 verbose(VERB_ALGO, "auth zone lookup failed, no fallback,"
2385 errinf(qstate, "auth zone lookup failed, fallback is off");
2386 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2388 if(iq->dp->auth_dp) {
2389 /* we wanted to fallback, but had no delegpt, only the
2390 * auth zone generated delegpt, create an actual one */
2391 iq->auth_zone_avoid = 1;
2392 return next_state(iq, INIT_REQUEST_STATE);
2394 /* but mostly, fallback==1 (like, when no such auth zone exists)
2395 * and we continue with lookups */
2398 /* < not <=, because although the array is large enough for <=, the
2399 * generated query will immediately be discarded due to depth and
2400 * that servfail is cached, which is not good as opportunism goes. */
2401 if(iq->depth < ie->max_dependency_depth
2402 && iq->num_target_queries == 0
2403 && (!iq->target_count || iq->target_count[2]==0)
2404 && iq->sent_count < TARGET_FETCH_STOP) {
2405 tf_policy = ie->target_fetch_policy[iq->depth];
2408 /* if in 0x20 fallback get as many targets as possible */
2409 if(iq->caps_fallback) {
2411 size_t naddr, nres, navail;
2412 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
2413 errinf(qstate, "could not fetch nameservers for 0x20 fallback");
2414 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2416 iq->num_target_queries += extra;
2417 target_count_increase(iq, extra);
2418 if(iq->num_target_queries > 0) {
2419 /* wait to get all targets, we want to try em */
2420 verbose(VERB_ALGO, "wait for all targets for fallback");
2421 qstate->ext_state[id] = module_wait_reply;
2422 /* undo qname minimise step because we'll get back here
2424 if(qout_orig && iq->minimise_count > 0) {
2425 iq->minimise_count--;
2426 iq->qinfo_out.qname = qout_orig;
2427 iq->qinfo_out.qname_len = qout_orig_len;
2431 /* did we do enough fallback queries already? */
2432 delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
2433 /* the current caps_server is the number of fallbacks sent.
2434 * the original query is one that matched too, so we have
2435 * caps_server+1 number of matching queries now */
2436 if(iq->caps_server+1 >= naddr*3 ||
2437 iq->caps_server*2+2 >= MAX_SENT_COUNT) {
2438 /* *2 on sentcount check because ipv6 may fail */
2439 /* we're done, process the response */
2440 verbose(VERB_ALGO, "0x20 fallback had %d responses "
2441 "match for %d wanted, done.",
2442 (int)iq->caps_server+1, (int)naddr*3);
2443 iq->response = iq->caps_response;
2444 iq->caps_fallback = 0;
2445 iter_dec_attempts(iq->dp, 3); /* space for fallback */
2446 iq->num_current_queries++; /* RespState decrements it*/
2447 iq->referral_count++; /* make sure we don't loop */
2449 iq->dp_target_count = 0;
2450 iq->state = QUERY_RESP_STATE;
2453 verbose(VERB_ALGO, "0x20 fallback number %d",
2454 (int)iq->caps_server);
2456 /* if there is a policy to fetch missing targets
2457 * opportunistically, do it. we rely on the fact that once a
2458 * query (or queries) for a missing name have been issued,
2459 * they will not show up again. */
2460 } else if(tf_policy != 0) {
2462 verbose(VERB_ALGO, "attempt to get extra %d targets",
2464 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
2465 /* errors ignored, these targets are not strictly necessary for
2466 * this result, we do not have to reply with SERVFAIL */
2467 iq->num_target_queries += extra;
2468 target_count_increase(iq, extra);
2471 /* Add the current set of unused targets to our queue. */
2472 delegpt_add_unused_targets(iq->dp);
2474 /* Select the next usable target, filtering out unsuitable targets. */
2475 target = iter_server_selection(ie, qstate->env, iq->dp,
2476 iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
2477 &iq->dnssec_lame_query, &iq->chase_to_rd,
2478 iq->num_target_queries, qstate->blacklist,
2479 qstate->prefetch_leeway);
2481 /* If no usable target was selected... */
2483 /* Here we distinguish between three states: generate a new
2484 * target query, just wait, or quit (with a SERVFAIL).
2485 * We have the following information: number of active
2486 * target queries, number of active current queries,
2487 * the presence of missing targets at this delegation
2488 * point, and the given query target policy. */
2490 /* Check for the wait condition. If this is true, then
2491 * an action must be taken. */
2492 if(iq->num_target_queries==0 && iq->num_current_queries==0) {
2493 /* If there is nothing to wait for, then we need
2494 * to distinguish between generating (a) new target
2495 * query, or failing. */
2496 if(delegpt_count_missing_targets(iq->dp) > 0) {
2498 verbose(VERB_ALGO, "querying for next "
2500 if(!query_for_targets(qstate, iq, ie, id,
2502 errinf(qstate, "could not fetch nameserver");
2503 errinf_dname(qstate, "at zone", iq->dp->name);
2504 return error_response(qstate, id,
2505 LDNS_RCODE_SERVFAIL);
2508 delegpt_count_missing_targets(iq->dp) == 0){
2509 /* it looked like there were missing
2510 * targets, but they did not turn up.
2511 * Try the bad choices again (if any),
2512 * when we get back here missing==0,
2513 * so this is not a loop. */
2516 iq->num_target_queries += qs;
2517 target_count_increase(iq, qs);
2519 /* Since a target query might have been made, we
2520 * need to check again. */
2521 if(iq->num_target_queries == 0) {
2522 /* if in capsforid fallback, instead of last
2523 * resort, we agree with the current reply
2524 * we have (if any) (our count of addrs bad)*/
2525 if(iq->caps_fallback && iq->caps_reply) {
2526 /* we're done, process the response */
2527 verbose(VERB_ALGO, "0x20 fallback had %d responses, "
2528 "but no more servers except "
2529 "last resort, done.",
2530 (int)iq->caps_server+1);
2531 iq->response = iq->caps_response;
2532 iq->caps_fallback = 0;
2533 iter_dec_attempts(iq->dp, 3); /* space for fallback */
2534 iq->num_current_queries++; /* RespState decrements it*/
2535 iq->referral_count++; /* make sure we don't loop */
2537 iq->dp_target_count = 0;
2538 iq->state = QUERY_RESP_STATE;
2541 return processLastResort(qstate, iq, ie, id);
2545 /* otherwise, we have no current targets, so submerge
2546 * until one of the target or direct queries return. */
2547 if(iq->num_target_queries>0 && iq->num_current_queries>0) {
2548 verbose(VERB_ALGO, "no current targets -- waiting "
2549 "for %d targets to resolve or %d outstanding"
2550 " queries to respond", iq->num_target_queries,
2551 iq->num_current_queries);
2552 qstate->ext_state[id] = module_wait_reply;
2553 } else if(iq->num_target_queries>0) {
2554 verbose(VERB_ALGO, "no current targets -- waiting "
2555 "for %d targets to resolve.",
2556 iq->num_target_queries);
2557 qstate->ext_state[id] = module_wait_subquery;
2559 verbose(VERB_ALGO, "no current targets -- waiting "
2560 "for %d outstanding queries to respond.",
2561 iq->num_current_queries);
2562 qstate->ext_state[id] = module_wait_reply;
2564 /* undo qname minimise step because we'll get back here
2566 if(qout_orig && iq->minimise_count > 0) {
2567 iq->minimise_count--;
2568 iq->qinfo_out.qname = qout_orig;
2569 iq->qinfo_out.qname_len = qout_orig_len;
2574 /* if not forwarding, check ratelimits per delegationpoint name */
2575 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
2576 if(!infra_ratelimit_inc(qstate->env->infra_cache, iq->dp->name,
2577 iq->dp->namelen, *qstate->env->now, &qstate->qinfo,
2579 lock_basic_lock(&ie->queries_ratelimit_lock);
2580 ie->num_queries_ratelimited++;
2581 lock_basic_unlock(&ie->queries_ratelimit_lock);
2582 verbose(VERB_ALGO, "query exceeded ratelimits");
2583 qstate->was_ratelimited = 1;
2584 errinf_dname(qstate, "exceeded ratelimit for zone",
2586 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2590 /* We have a valid target. */
2591 if(verbosity >= VERB_QUERY) {
2592 log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out);
2593 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
2594 &target->addr, target->addrlen);
2595 verbose(VERB_ALGO, "dnssec status: %s%s",
2596 iq->dnssec_expected?"expected": "not expected",
2597 iq->dnssec_lame_query?" but lame_query anyway": "");
2599 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
2600 outq = (*qstate->env->send_query)(&iq->qinfo_out,
2601 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0),
2602 /* unset CD if to forwarder(RD set) and not dnssec retry
2603 * (blacklist nonempty) and no trust-anchors are configured
2604 * above the qname or on the first attempt when dnssec is on */
2605 EDNS_DO| ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&&
2606 !qstate->blacklist&&(!iter_qname_indicates_dnssec(qstate->env,
2607 &iq->qinfo_out)||target->attempts==1)?0:BIT_CD),
2608 iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted(
2609 ie, iq), &target->addr, target->addrlen,
2610 iq->dp->name, iq->dp->namelen,
2611 (iq->dp->ssl_upstream || qstate->env->cfg->ssl_upstream),
2612 target->tls_auth_name, qstate);
2614 log_addr(VERB_DETAIL, "error sending query to auth server",
2615 &target->addr, target->addrlen);
2616 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok)
2617 infra_ratelimit_dec(qstate->env->infra_cache, iq->dp->name,
2618 iq->dp->namelen, *qstate->env->now);
2619 if(qstate->env->cfg->qname_minimisation)
2620 iq->minimisation_state = SKIP_MINIMISE_STATE;
2621 return next_state(iq, QUERYTARGETS_STATE);
2623 outbound_list_insert(&iq->outlist, outq);
2624 iq->num_current_queries++;
2626 qstate->ext_state[id] = module_wait_reply;
2631 /** find NS rrset in given list */
2632 static struct ub_packed_rrset_key*
2633 find_NS(struct reply_info* rep, size_t from, size_t to)
2636 for(i=from; i<to; i++) {
2637 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
2638 return rep->rrsets[i];
2645 * Process the query response. All queries end up at this state first. This
2646 * process generally consists of analyzing the response and routing the
2647 * event to the next state (either bouncing it back to a request state, or
2648 * terminating the processing for this event).
2650 * @param qstate: query state.
2651 * @param iq: iterator query state.
2652 * @param id: module id.
2653 * @return true if the event requires more immediate processing, false if
2654 * not. This is generally only true when forwarding the request to
2655 * the final state (i.e., on answer).
2658 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
2662 enum response_type type;
2663 iq->num_current_queries--;
2665 if(!inplace_cb_query_response_call(qstate->env, qstate, iq->response))
2666 log_err("unable to call query_response callback");
2668 if(iq->response == NULL) {
2669 /* Don't increment qname when QNAME minimisation is enabled */
2670 if(qstate->env->cfg->qname_minimisation) {
2671 iq->minimisation_state = SKIP_MINIMISE_STATE;
2673 iq->timeout_count++;
2674 iq->chase_to_rd = 0;
2675 iq->dnssec_lame_query = 0;
2676 verbose(VERB_ALGO, "query response was timeout");
2677 return next_state(iq, QUERYTARGETS_STATE);
2679 iq->timeout_count = 0;
2680 type = response_type_from_server(
2681 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
2682 iq->response, &iq->qinfo_out, iq->dp);
2683 iq->chase_to_rd = 0;
2684 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD) &&
2685 !iq->auth_zone_response) {
2686 /* When forwarding (RD bit is set), we handle referrals
2687 * differently. No queries should be sent elsewhere */
2688 type = RESPONSE_TYPE_ANSWER;
2690 if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected
2691 && !iq->dnssec_lame_query &&
2692 !(iq->chase_flags&BIT_RD)
2693 && iq->sent_count < DNSSEC_LAME_DETECT_COUNT
2694 && type != RESPONSE_TYPE_LAME
2695 && type != RESPONSE_TYPE_REC_LAME
2696 && type != RESPONSE_TYPE_THROWAWAY
2697 && type != RESPONSE_TYPE_UNTYPED) {
2698 /* a possible answer, see if it is missing DNSSEC */
2699 /* but not when forwarding, so we dont mark fwder lame */
2700 if(!iter_msg_has_dnssec(iq->response)) {
2701 /* Mark this address as dnsseclame in this dp,
2702 * because that will make serverselection disprefer
2703 * it, but also, once it is the only final option,
2704 * use dnssec-lame-bypass if it needs to query there.*/
2706 struct delegpt_addr* a = delegpt_find_addr(
2707 iq->dp, &qstate->reply->addr,
2708 qstate->reply->addrlen);
2709 if(a) a->dnsseclame = 1;
2711 /* test the answer is from the zone we expected,
2712 * otherwise, (due to parent,child on same server), we
2713 * might mark the server,zone lame inappropriately */
2714 if(!iter_msg_from_zone(iq->response, iq->dp, type,
2716 qstate->reply = NULL;
2717 type = RESPONSE_TYPE_LAME;
2720 } else iq->dnssec_lame_query = 0;
2721 /* see if referral brings us close to the target */
2722 if(type == RESPONSE_TYPE_REFERRAL) {
2723 struct ub_packed_rrset_key* ns = find_NS(
2724 iq->response->rep, iq->response->rep->an_numrrsets,
2725 iq->response->rep->an_numrrsets
2726 + iq->response->rep->ns_numrrsets);
2727 if(!ns) ns = find_NS(iq->response->rep, 0,
2728 iq->response->rep->an_numrrsets);
2729 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
2730 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
2731 verbose(VERB_ALGO, "bad referral, throwaway");
2732 type = RESPONSE_TYPE_THROWAWAY;
2734 iter_scrub_ds(iq->response, ns, iq->dp->name);
2735 } else iter_scrub_ds(iq->response, NULL, NULL);
2736 if(type == RESPONSE_TYPE_THROWAWAY &&
2737 FLAGS_GET_RCODE(iq->response->rep->flags) == LDNS_RCODE_YXDOMAIN) {
2738 /* YXDOMAIN is a permanent error, no need to retry */
2739 type = RESPONSE_TYPE_ANSWER;
2741 if(type == RESPONSE_TYPE_CNAME && iq->response->rep->an_numrrsets >= 1
2742 && ntohs(iq->response->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DNAME) {
2743 uint8_t* sname = NULL;
2744 size_t snamelen = 0;
2745 get_cname_target(iq->response->rep->rrsets[0], &sname,
2747 if(snamelen && dname_subdomain_c(sname, iq->response->rep->rrsets[0]->rk.dname)) {
2748 /* DNAME to a subdomain loop; do not recurse */
2749 type = RESPONSE_TYPE_ANSWER;
2751 } else if(type == RESPONSE_TYPE_CNAME &&
2752 iq->qchase.qtype == LDNS_RR_TYPE_CNAME &&
2753 iq->minimisation_state == MINIMISE_STATE &&
2754 query_dname_compare(iq->qchase.qname, iq->qinfo_out.qname) == 0) {
2755 /* The minimised query for full QTYPE and hidden QTYPE can be
2756 * classified as CNAME response type, even when the original
2757 * QTYPE=CNAME. This should be treated as answer response type.
2759 type = RESPONSE_TYPE_ANSWER;
2762 /* handle each of the type cases */
2763 if(type == RESPONSE_TYPE_ANSWER) {
2764 /* ANSWER type responses terminate the query algorithm,
2765 * so they sent on their */
2766 if(verbosity >= VERB_DETAIL) {
2767 verbose(VERB_DETAIL, "query response was %s",
2768 FLAGS_GET_RCODE(iq->response->rep->flags)
2769 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
2770 (iq->response->rep->an_numrrsets?"ANSWER":
2773 /* if qtype is DS, check we have the right level of answer,
2774 * like grandchild answer but we need the middle, reject it */
2775 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
2776 && !(iq->chase_flags&BIT_RD)
2777 && iter_ds_toolow(iq->response, iq->dp)
2778 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
2779 /* close down outstanding requests to be discarded */
2780 outbound_list_clear(&iq->outlist);
2781 iq->num_current_queries = 0;
2782 fptr_ok(fptr_whitelist_modenv_detach_subs(
2783 qstate->env->detach_subs));
2784 (*qstate->env->detach_subs)(qstate);
2785 iq->num_target_queries = 0;
2786 return processDSNSFind(qstate, iq, id);
2788 if(!qstate->no_cache_store)
2789 iter_dns_store(qstate->env, &iq->response->qinfo,
2790 iq->response->rep, 0, qstate->prefetch_leeway,
2791 iq->dp&&iq->dp->has_parent_side_NS,
2792 qstate->region, qstate->query_flags);
2793 /* close down outstanding requests to be discarded */
2794 outbound_list_clear(&iq->outlist);
2795 iq->num_current_queries = 0;
2796 fptr_ok(fptr_whitelist_modenv_detach_subs(
2797 qstate->env->detach_subs));
2798 (*qstate->env->detach_subs)(qstate);
2799 iq->num_target_queries = 0;
2801 sock_list_insert(&qstate->reply_origin,
2802 &qstate->reply->addr, qstate->reply->addrlen,
2804 if(iq->minimisation_state != DONOT_MINIMISE_STATE
2805 && !(iq->chase_flags & BIT_RD)) {
2806 if(FLAGS_GET_RCODE(iq->response->rep->flags) !=
2807 LDNS_RCODE_NOERROR) {
2808 if(qstate->env->cfg->qname_minimisation_strict) {
2809 if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
2810 LDNS_RCODE_NXDOMAIN) {
2811 iter_scrub_nxdomain(iq->response);
2812 return final_state(iq);
2814 return error_response(qstate, id,
2815 LDNS_RCODE_SERVFAIL);
2817 /* Best effort qname-minimisation.
2818 * Stop minimising and send full query when
2819 * RCODE is not NOERROR. */
2820 iq->minimisation_state = DONOT_MINIMISE_STATE;
2822 if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
2823 LDNS_RCODE_NXDOMAIN) {
2824 /* Stop resolving when NXDOMAIN is DNSSEC
2825 * signed. Based on assumption that nameservers
2826 * serving signed zones do not return NXDOMAIN
2827 * for empty-non-terminals. */
2828 if(iq->dnssec_expected)
2829 return final_state(iq);
2830 /* Make subrequest to validate intermediate
2831 * NXDOMAIN if harden-below-nxdomain is
2833 if(qstate->env->cfg->harden_below_nxdomain &&
2834 qstate->env->need_to_validate) {
2835 struct module_qstate* subq = NULL;
2836 log_query_info(VERB_QUERY,
2837 "schedule NXDOMAIN validation:",
2838 &iq->response->qinfo);
2839 if(!generate_sub_request(
2840 iq->response->qinfo.qname,
2841 iq->response->qinfo.qname_len,
2842 iq->response->qinfo.qtype,
2843 iq->response->qinfo.qclass,
2846 FINISHED_STATE, &subq, 1, 1))
2848 "could not validate NXDOMAIN "
2852 return next_state(iq, QUERYTARGETS_STATE);
2854 return final_state(iq);
2855 } else if(type == RESPONSE_TYPE_REFERRAL) {
2856 /* REFERRAL type responses get a reset of the
2857 * delegation point, and back to the QUERYTARGETS_STATE. */
2858 verbose(VERB_DETAIL, "query response was REFERRAL");
2860 if(!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok) {
2861 /* we have a referral, no ratelimit, we can send
2862 * our queries to the given name */
2863 infra_ratelimit_dec(qstate->env->infra_cache,
2864 iq->dp->name, iq->dp->namelen,
2868 /* if hardened, only store referral if we asked for it */
2869 if(!qstate->no_cache_store &&
2870 (!qstate->env->cfg->harden_referral_path ||
2871 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
2872 && (qstate->query_flags&BIT_RD)
2873 && !(qstate->query_flags&BIT_CD)
2874 /* we know that all other NS rrsets are scrubbed
2875 * away, thus on referral only one is left.
2876 * see if that equals the query name... */
2877 && ( /* auth section, but sometimes in answer section*/
2878 reply_find_rrset_section_ns(iq->response->rep,
2879 iq->qchase.qname, iq->qchase.qname_len,
2880 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2881 || reply_find_rrset_section_an(iq->response->rep,
2882 iq->qchase.qname, iq->qchase.qname_len,
2883 LDNS_RR_TYPE_NS, iq->qchase.qclass)
2886 /* Store the referral under the current query */
2887 /* no prefetch-leeway, since its not the answer */
2888 iter_dns_store(qstate->env, &iq->response->qinfo,
2889 iq->response->rep, 1, 0, 0, NULL, 0);
2890 if(iq->store_parent_NS)
2891 iter_store_parentside_NS(qstate->env,
2893 if(qstate->env->neg_cache)
2894 val_neg_addreferral(qstate->env->neg_cache,
2895 iq->response->rep, iq->dp->name);
2897 /* store parent-side-in-zone-glue, if directly queried for */
2898 if(!qstate->no_cache_store && iq->query_for_pside_glue
2899 && !iq->pside_glue) {
2900 iq->pside_glue = reply_find_rrset(iq->response->rep,
2901 iq->qchase.qname, iq->qchase.qname_len,
2902 iq->qchase.qtype, iq->qchase.qclass);
2903 if(iq->pside_glue) {
2904 log_rrset_key(VERB_ALGO, "found parent-side "
2905 "glue", iq->pside_glue);
2906 iter_store_parentside_rrset(qstate->env,
2911 /* Reset the event state, setting the current delegation
2912 * point to the referral. */
2913 iq->deleg_msg = iq->response;
2914 iq->dp = delegpt_from_message(iq->response, qstate->region);
2915 if (qstate->env->cfg->qname_minimisation)
2916 iq->minimisation_state = INIT_MINIMISE_STATE;
2918 errinf(qstate, "malloc failure, for delegation point");
2919 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2921 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
2922 qstate->region, iq->dp)) {
2923 errinf(qstate, "malloc failure, copy extra info into delegation point");
2924 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2926 if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
2927 iq->store_parent_NS->name) == 0)
2928 iter_merge_retry_counts(iq->dp, iq->store_parent_NS);
2929 delegpt_log(VERB_ALGO, iq->dp);
2930 /* Count this as a referral. */
2931 iq->referral_count++;
2933 iq->dp_target_count = 0;
2934 /* see if the next dp is a trust anchor, or a DS was sent
2935 * along, indicating dnssec is expected for next zone */
2936 iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
2937 iq->dp, iq->response, iq->qchase.qclass);
2938 /* if dnssec, validating then also fetch the key for the DS */
2939 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
2940 !(qstate->query_flags&BIT_CD))
2941 generate_dnskey_prefetch(qstate, iq, id);
2943 /* spawn off NS and addr to auth servers for the NS we just
2944 * got in the referral. This gets authoritative answer
2945 * (answer section trust level) rrset.
2946 * right after, we detach the subs, answer goes to cache. */
2947 if(qstate->env->cfg->harden_referral_path)
2948 generate_ns_check(qstate, iq, id);
2950 /* stop current outstanding queries.
2951 * FIXME: should the outstanding queries be waited for and
2952 * handled? Say by a subquery that inherits the outbound_entry.
2954 outbound_list_clear(&iq->outlist);
2955 iq->num_current_queries = 0;
2956 fptr_ok(fptr_whitelist_modenv_detach_subs(
2957 qstate->env->detach_subs));
2958 (*qstate->env->detach_subs)(qstate);
2959 iq->num_target_queries = 0;
2960 verbose(VERB_ALGO, "cleared outbound list for next round");
2961 return next_state(iq, QUERYTARGETS_STATE);
2962 } else if(type == RESPONSE_TYPE_CNAME) {
2963 uint8_t* sname = NULL;
2964 size_t snamelen = 0;
2965 /* CNAME type responses get a query restart (i.e., get a
2966 * reset of the query state and go back to INIT_REQUEST_STATE).
2968 verbose(VERB_DETAIL, "query response was CNAME");
2969 if(verbosity >= VERB_ALGO)
2970 log_dns_msg("cname msg", &iq->response->qinfo,
2972 /* if qtype is DS, check we have the right level of answer,
2973 * like grandchild answer but we need the middle, reject it */
2974 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
2975 && !(iq->chase_flags&BIT_RD)
2976 && iter_ds_toolow(iq->response, iq->dp)
2977 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
2978 outbound_list_clear(&iq->outlist);
2979 iq->num_current_queries = 0;
2980 fptr_ok(fptr_whitelist_modenv_detach_subs(
2981 qstate->env->detach_subs));
2982 (*qstate->env->detach_subs)(qstate);
2983 iq->num_target_queries = 0;
2984 return processDSNSFind(qstate, iq, id);
2986 /* Process the CNAME response. */
2987 if(!handle_cname_response(qstate, iq, iq->response,
2988 &sname, &snamelen)) {
2989 errinf(qstate, "malloc failure, CNAME info");
2990 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2992 /* cache the CNAME response under the current query */
2993 /* NOTE : set referral=1, so that rrsets get stored but not
2994 * the partial query answer (CNAME only). */
2995 /* prefetchleeway applied because this updates answer parts */
2996 if(!qstate->no_cache_store)
2997 iter_dns_store(qstate->env, &iq->response->qinfo,
2998 iq->response->rep, 1, qstate->prefetch_leeway,
2999 iq->dp&&iq->dp->has_parent_side_NS, NULL,
3000 qstate->query_flags);
3001 /* set the current request's qname to the new value. */
3002 iq->qchase.qname = sname;
3003 iq->qchase.qname_len = snamelen;
3004 /* Clear the query state, since this is a query restart. */
3005 iq->deleg_msg = NULL;
3007 iq->dsns_point = NULL;
3008 iq->auth_zone_response = 0;
3010 iq->dp_target_count = 0;
3011 if(iq->minimisation_state != MINIMISE_STATE)
3012 /* Only count as query restart when it is not an extra
3013 * query as result of qname minimisation. */
3014 iq->query_restart_count++;
3015 if(qstate->env->cfg->qname_minimisation)
3016 iq->minimisation_state = INIT_MINIMISE_STATE;
3018 /* stop current outstanding queries.
3019 * FIXME: should the outstanding queries be waited for and
3020 * handled? Say by a subquery that inherits the outbound_entry.
3022 outbound_list_clear(&iq->outlist);
3023 iq->num_current_queries = 0;
3024 fptr_ok(fptr_whitelist_modenv_detach_subs(
3025 qstate->env->detach_subs));
3026 (*qstate->env->detach_subs)(qstate);
3027 iq->num_target_queries = 0;
3029 sock_list_insert(&qstate->reply_origin,
3030 &qstate->reply->addr, qstate->reply->addrlen,
3032 verbose(VERB_ALGO, "cleared outbound list for query restart");
3033 /* go to INIT_REQUEST_STATE for new qname. */
3034 return next_state(iq, INIT_REQUEST_STATE);
3035 } else if(type == RESPONSE_TYPE_LAME) {
3036 /* Cache the LAMEness. */
3037 verbose(VERB_DETAIL, "query response was %sLAME",
3038 dnsseclame?"DNSSEC ":"");
3039 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
3040 log_err("mark lame: mismatch in qname and dpname");
3041 /* throwaway this reply below */
3042 } else if(qstate->reply) {
3043 /* need addr for lameness cache, but we may have
3044 * gotten this from cache, so test to be sure */
3045 if(!infra_set_lame(qstate->env->infra_cache,
3046 &qstate->reply->addr, qstate->reply->addrlen,
3047 iq->dp->name, iq->dp->namelen,
3048 *qstate->env->now, dnsseclame, 0,
3050 log_err("mark host lame: out of memory");
3052 } else if(type == RESPONSE_TYPE_REC_LAME) {
3053 /* Cache the LAMEness. */
3054 verbose(VERB_DETAIL, "query response REC_LAME: "
3055 "recursive but not authoritative server");
3056 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
3057 log_err("mark rec_lame: mismatch in qname and dpname");
3058 /* throwaway this reply below */
3059 } else if(qstate->reply) {
3060 /* need addr for lameness cache, but we may have
3061 * gotten this from cache, so test to be sure */
3062 verbose(VERB_DETAIL, "mark as REC_LAME");
3063 if(!infra_set_lame(qstate->env->infra_cache,
3064 &qstate->reply->addr, qstate->reply->addrlen,
3065 iq->dp->name, iq->dp->namelen,
3066 *qstate->env->now, 0, 1, iq->qchase.qtype))
3067 log_err("mark host lame: out of memory");
3069 } else if(type == RESPONSE_TYPE_THROWAWAY) {
3070 /* LAME and THROWAWAY responses are handled the same way.
3071 * In this case, the event is just sent directly back to
3072 * the QUERYTARGETS_STATE without resetting anything,
3073 * because, clearly, the next target must be tried. */
3074 verbose(VERB_DETAIL, "query response was THROWAWAY");
3076 log_warn("A query response came back with an unknown type: %d",
3080 /* LAME, THROWAWAY and "unknown" all end up here.
3081 * Recycle to the QUERYTARGETS state to hopefully try a
3082 * different target. */
3083 if (qstate->env->cfg->qname_minimisation &&
3084 !qstate->env->cfg->qname_minimisation_strict)
3085 iq->minimisation_state = DONOT_MINIMISE_STATE;
3086 if(iq->auth_zone_response) {
3087 /* can we fallback? */
3088 iq->auth_zone_response = 0;
3089 if(!auth_zones_can_fallback(qstate->env->auth_zones,
3090 iq->dp->name, iq->dp->namelen, qstate->qinfo.qclass)) {
3091 verbose(VERB_ALGO, "auth zone response bad, and no"
3092 " fallback possible, servfail");
3093 errinf_dname(qstate, "response is bad, no fallback, "
3094 "for auth zone", iq->dp->name);
3095 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3097 verbose(VERB_ALGO, "auth zone response was bad, "
3098 "fallback enabled");
3099 iq->auth_zone_avoid = 1;
3100 if(iq->dp->auth_dp) {
3101 /* we are using a dp for the auth zone, with no
3102 * nameservers, get one first */
3104 return next_state(iq, INIT_REQUEST_STATE);
3107 return next_state(iq, QUERYTARGETS_STATE);
3111 * Return priming query results to interested super querystates.
3113 * Sets the delegation point and delegation message (not nonRD queries).
3114 * This is a callback from walk_supers.
3116 * @param qstate: priming query state that finished.
3117 * @param id: module id.
3118 * @param forq: the qstate for which priming has been done.
3121 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
3123 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3124 struct delegpt* dp = NULL;
3126 log_assert(qstate->is_priming || foriq->wait_priming_stub);
3127 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
3128 /* Convert our response to a delegation point */
3129 dp = delegpt_from_message(qstate->return_msg, forq->region);
3131 /* if there is no convertable delegation point, then
3132 * the ANSWER type was (presumably) a negative answer. */
3133 verbose(VERB_ALGO, "prime response was not a positive "
3136 foriq->state = QUERYTARGETS_STATE;
3140 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
3141 delegpt_log(VERB_ALGO, dp);
3143 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
3144 if(!foriq->deleg_msg) {
3145 log_err("copy prime response: out of memory");
3147 foriq->state = QUERYTARGETS_STATE;
3151 /* root priming responses go to init stage 2, priming stub
3152 * responses to to stage 3. */
3153 if(foriq->wait_priming_stub) {
3154 foriq->state = INIT_REQUEST_3_STATE;
3155 foriq->wait_priming_stub = 0;
3156 } else foriq->state = INIT_REQUEST_2_STATE;
3157 /* because we are finished, the parent will be reactivated */
3161 * This handles the response to a priming query. This is used to handle both
3162 * root and stub priming responses. This is basically the equivalent of the
3163 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat
3164 * REFERRALs as ANSWERS. It will also update and reactivate the originating
3167 * @param qstate: query state.
3168 * @param id: module id.
3169 * @return true if the event needs more immediate processing, false if not.
3170 * This state always returns false.
3173 processPrimeResponse(struct module_qstate* qstate, int id)
3175 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3176 enum response_type type;
3177 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
3178 type = response_type_from_server(
3179 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
3180 iq->response, &iq->qchase, iq->dp);
3181 if(type == RESPONSE_TYPE_ANSWER) {
3182 qstate->return_rcode = LDNS_RCODE_NOERROR;
3183 qstate->return_msg = iq->response;
3185 errinf(qstate, "prime response did not get an answer");
3186 errinf_dname(qstate, "for", qstate->qinfo.qname);
3187 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
3188 qstate->return_msg = NULL;
3191 /* validate the root or stub after priming (if enabled).
3192 * This is the same query as the prime query, but with validation.
3193 * Now that we are primed, the additional queries that validation
3194 * may need can be resolved, such as DLV. */
3195 if(qstate->env->cfg->harden_referral_path) {
3196 struct module_qstate* subq = NULL;
3197 log_nametypeclass(VERB_ALGO, "schedule prime validation",
3198 qstate->qinfo.qname, qstate->qinfo.qtype,
3199 qstate->qinfo.qclass);
3200 if(!generate_sub_request(qstate->qinfo.qname,
3201 qstate->qinfo.qname_len, qstate->qinfo.qtype,
3202 qstate->qinfo.qclass, qstate, id, iq,
3203 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
3204 verbose(VERB_ALGO, "could not generate prime check");
3206 generate_a_aaaa_check(qstate, iq, id);
3209 /* This event is finished. */
3210 qstate->ext_state[id] = module_finished;
3215 * Do final processing on responses to target queries. Events reach this
3216 * state after the iterative resolution algorithm terminates. This state is
3217 * responsible for reactivating the original event, and housekeeping related
3218 * to received target responses (caching, updating the current delegation
3220 * Callback from walk_supers for every super state that is interested in
3221 * the results from this query.
3223 * @param qstate: query state.
3224 * @param id: module id.
3225 * @param forq: super query state.
3228 processTargetResponse(struct module_qstate* qstate, int id,
3229 struct module_qstate* forq)
3231 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
3232 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3233 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3234 struct ub_packed_rrset_key* rrset;
3235 struct delegpt_ns* dpns;
3236 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
3238 foriq->state = QUERYTARGETS_STATE;
3239 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
3240 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
3242 /* Tell the originating event that this target query has finished
3243 * (regardless if it succeeded or not). */
3244 foriq->num_target_queries--;
3246 /* check to see if parent event is still interested (in orig name). */
3248 verbose(VERB_ALGO, "subq: parent not interested, was reset");
3249 return; /* not interested anymore */
3251 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
3252 qstate->qinfo.qname_len);
3254 /* If not interested, just stop processing this event */
3255 verbose(VERB_ALGO, "subq: parent not interested anymore");
3256 /* could be because parent was jostled out of the cache,
3257 and a new identical query arrived, that does not want it*/
3261 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
3262 if(iq->pside_glue) {
3263 /* if the pside_glue is NULL, then it could not be found,
3264 * the done_pside is already set when created and a cache
3265 * entry created in processFinished so nothing to do here */
3266 log_rrset_key(VERB_ALGO, "add parentside glue to dp",
3268 if(!delegpt_add_rrset(foriq->dp, forq->region,
3269 iq->pside_glue, 1, NULL))
3270 log_err("out of memory adding pside glue");
3273 /* This response is relevant to the current query, so we
3274 * add (attempt to add, anyway) this target(s) and reactivate
3275 * the original event.
3276 * NOTE: we could only look for the AnswerRRset if the
3277 * response type was ANSWER. */
3278 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
3281 /* if CNAMEs have been followed - add new NS to delegpt. */
3282 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
3283 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
3284 rrset->rk.dname_len)) {
3285 /* if dpns->lame then set newcname ns lame too */
3286 if(!delegpt_add_ns(foriq->dp, forq->region,
3287 rrset->rk.dname, dpns->lame))
3288 log_err("out of memory adding cnamed-ns");
3290 /* if dpns->lame then set the address(es) lame too */
3291 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
3292 dpns->lame, &additions))
3293 log_err("out of memory adding targets");
3295 /* no new addresses, increase the nxns counter, like
3296 * this could be a list of wildcards with no new
3298 target_count_increase_nx(foriq, 1);
3300 verbose(VERB_ALGO, "added target response");
3301 delegpt_log(VERB_ALGO, foriq->dp);
3303 verbose(VERB_ALGO, "iterator TargetResponse failed");
3304 delegpt_mark_neg(dpns, qstate->qinfo.qtype);
3305 dpns->resolved = 1; /* fail the target */
3306 if((dpns->got4 == 2 || !ie->supports_ipv4) &&
3307 (dpns->got6 == 2 || !ie->supports_ipv6))
3308 target_count_increase_nx(foriq, 1);
3313 * Process response for DS NS Find queries, that attempt to find the delegation
3314 * point where we ask the DS query from.
3316 * @param qstate: query state.
3317 * @param id: module id.
3318 * @param forq: super query state.
3321 processDSNSResponse(struct module_qstate* qstate, int id,
3322 struct module_qstate* forq)
3324 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3326 /* if the finished (iq->response) query has no NS set: continue
3327 * up to look for the right dp; nothing to change, do DPNSstate */
3328 if(qstate->return_rcode != LDNS_RCODE_NOERROR)
3329 return; /* seek further */
3330 /* find the NS RRset (without allowing CNAMEs) */
3331 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
3332 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
3333 qstate->qinfo.qclass)){
3334 return; /* seek further */
3337 /* else, store as DP and continue at querytargets */
3338 foriq->state = QUERYTARGETS_STATE;
3339 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
3341 log_err("out of memory in dsns dp alloc");
3342 errinf(qstate, "malloc failure, in DS search");
3343 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
3345 /* success, go query the querytargets in the new dp (and go down) */
3349 * Process response for qclass=ANY queries for a particular class.
3350 * Append to result or error-exit.
3352 * @param qstate: query state.
3353 * @param id: module id.
3354 * @param forq: super query state.
3357 processClassResponse(struct module_qstate* qstate, int id,
3358 struct module_qstate* forq)
3360 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3361 struct dns_msg* from = qstate->return_msg;
3362 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
3363 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
3364 if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
3365 /* cause servfail for qclass ANY query */
3366 foriq->response = NULL;
3367 foriq->state = FINISHED_STATE;
3371 if(!foriq->response) {
3372 /* allocate the response: copy RCODE, sec_state */
3373 foriq->response = dns_copy_msg(from, forq->region);
3374 if(!foriq->response) {
3375 log_err("malloc failed for qclass ANY response");
3376 foriq->state = FINISHED_STATE;
3379 foriq->response->qinfo.qclass = forq->qinfo.qclass;
3380 /* qclass ANY does not receive the AA flag on replies */
3381 foriq->response->rep->authoritative = 0;
3383 struct dns_msg* to = foriq->response;
3384 /* add _from_ this response _to_ existing collection */
3385 /* if there are records, copy RCODE */
3386 /* lower sec_state if this message is lower */
3387 if(from->rep->rrset_count != 0) {
3388 size_t n = from->rep->rrset_count+to->rep->rrset_count;
3389 struct ub_packed_rrset_key** dest, **d;
3390 /* copy appropriate rcode */
3391 to->rep->flags = from->rep->flags;
3393 if(from->rep->rrset_count > RR_COUNT_MAX ||
3394 to->rep->rrset_count > RR_COUNT_MAX) {
3395 log_err("malloc failed (too many rrsets) in collect ANY");
3396 foriq->state = FINISHED_STATE;
3397 return; /* integer overflow protection */
3399 dest = regional_alloc(forq->region, sizeof(dest[0])*n);
3401 log_err("malloc failed in collect ANY");
3402 foriq->state = FINISHED_STATE;
3407 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
3409 dest += to->rep->an_numrrsets;
3410 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
3412 dest += from->rep->an_numrrsets;
3414 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
3415 to->rep->ns_numrrsets * sizeof(dest[0]));
3416 dest += to->rep->ns_numrrsets;
3417 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
3418 from->rep->ns_numrrsets * sizeof(dest[0]));
3419 dest += from->rep->ns_numrrsets;
3421 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
3422 to->rep->ns_numrrsets,
3423 to->rep->ar_numrrsets * sizeof(dest[0]));
3424 dest += to->rep->ar_numrrsets;
3425 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
3426 from->rep->ns_numrrsets,
3427 from->rep->ar_numrrsets * sizeof(dest[0]));
3429 to->rep->rrsets = d;
3430 to->rep->an_numrrsets += from->rep->an_numrrsets;
3431 to->rep->ns_numrrsets += from->rep->ns_numrrsets;
3432 to->rep->ar_numrrsets += from->rep->ar_numrrsets;
3433 to->rep->rrset_count = n;
3435 if(from->rep->security < to->rep->security) /* lowest sec */
3436 to->rep->security = from->rep->security;
3437 if(from->rep->qdcount != 0) /* insert qd if appropriate */
3438 to->rep->qdcount = from->rep->qdcount;
3439 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
3440 to->rep->ttl = from->rep->ttl;
3441 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
3442 to->rep->prefetch_ttl = from->rep->prefetch_ttl;
3443 if(from->rep->serve_expired_ttl < to->rep->serve_expired_ttl)
3444 to->rep->serve_expired_ttl = from->rep->serve_expired_ttl;
3447 foriq->num_current_queries --;
3448 if(foriq->num_current_queries == 0)
3449 foriq->state = FINISHED_STATE;
3453 * Collect class ANY responses and make them into one response. This
3454 * state is started and it creates queries for all classes (that have
3455 * root hints). The answers are then collected.
3457 * @param qstate: query state.
3458 * @param id: module id.
3459 * @return true if the event needs more immediate processing, false if not.
3462 processCollectClass(struct module_qstate* qstate, int id)
3464 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3465 struct module_qstate* subq;
3466 /* If qchase.qclass == 0 then send out queries for all classes.
3467 * Otherwise, do nothing (wait for all answers to arrive and the
3468 * processClassResponse to put them together, and that moves us
3469 * towards the Finished state when done. */
3470 if(iq->qchase.qclass == 0) {
3472 iq->qchase.qclass = LDNS_RR_CLASS_ANY;
3473 while(iter_get_next_root(qstate->env->hints,
3474 qstate->env->fwds, &c)) {
3475 /* generate query for this class */
3476 log_nametypeclass(VERB_ALGO, "spawn collect query",
3477 qstate->qinfo.qname, qstate->qinfo.qtype, c);
3478 if(!generate_sub_request(qstate->qinfo.qname,
3479 qstate->qinfo.qname_len, qstate->qinfo.qtype,
3480 c, qstate, id, iq, INIT_REQUEST_STATE,
3481 FINISHED_STATE, &subq,
3482 (int)!(qstate->query_flags&BIT_CD), 0)) {
3483 errinf(qstate, "could not generate class ANY"
3485 return error_response(qstate, id,
3486 LDNS_RCODE_SERVFAIL);
3488 /* ignore subq, no special init required */
3489 iq->num_current_queries ++;
3494 /* if no roots are configured at all, return */
3495 if(iq->num_current_queries == 0) {
3496 verbose(VERB_ALGO, "No root hints or fwds, giving up "
3498 return error_response(qstate, id, LDNS_RCODE_REFUSED);
3500 /* return false, wait for queries to return */
3502 /* if woke up here because of an answer, wait for more answers */
3507 * This handles the final state for first-tier responses (i.e., responses to
3508 * externally generated queries).
3510 * @param qstate: query state.
3511 * @param iq: iterator query state.
3512 * @param id: module id.
3513 * @return true if the event needs more processing, false if not. Since this
3514 * is the final state for an event, it always returns false.
3517 processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
3520 log_query_info(VERB_QUERY, "finishing processing for",
3523 /* store negative cache element for parent side glue. */
3524 if(!qstate->no_cache_store && iq->query_for_pside_glue
3526 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
3527 iq->deleg_msg?iq->deleg_msg->rep:
3528 (iq->response?iq->response->rep:NULL));
3530 verbose(VERB_ALGO, "No response is set, servfail");
3531 errinf(qstate, "(no response found at query finish)");
3532 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3535 /* Make sure that the RA flag is set (since the presence of
3536 * this module means that recursion is available) */
3537 iq->response->rep->flags |= BIT_RA;
3539 /* Clear the AA flag */
3540 /* FIXME: does this action go here or in some other module? */
3541 iq->response->rep->flags &= ~BIT_AA;
3543 /* make sure QR flag is on */
3544 iq->response->rep->flags |= BIT_QR;
3546 /* we have finished processing this query */
3547 qstate->ext_state[id] = module_finished;
3549 /* TODO: we are using a private TTL, trim the response. */
3550 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
3552 /* prepend any items we have accumulated */
3553 if(iq->an_prepend_list || iq->ns_prepend_list) {
3554 if(!iter_prepend(iq, iq->response, qstate->region)) {
3555 log_err("prepend rrsets: out of memory");
3556 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3558 /* reset the query name back */
3559 iq->response->qinfo = qstate->qinfo;
3560 /* the security state depends on the combination */
3561 iq->response->rep->security = sec_status_unchecked;
3562 /* store message with the finished prepended items,
3563 * but only if we did recursion. The nonrecursion referral
3564 * from cache does not need to be stored in the msg cache. */
3565 if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) {
3566 iter_dns_store(qstate->env, &qstate->qinfo,
3567 iq->response->rep, 0, qstate->prefetch_leeway,
3568 iq->dp&&iq->dp->has_parent_side_NS,
3569 qstate->region, qstate->query_flags);
3572 qstate->return_rcode = LDNS_RCODE_NOERROR;
3573 qstate->return_msg = iq->response;
3578 * Return priming query results to interested super querystates.
3580 * Sets the delegation point and delegation message (not nonRD queries).
3581 * This is a callback from walk_supers.
3583 * @param qstate: query state that finished.
3584 * @param id: module id.
3585 * @param super: the qstate to inform.
3588 iter_inform_super(struct module_qstate* qstate, int id,
3589 struct module_qstate* super)
3591 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
3592 processClassResponse(qstate, id, super);
3593 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
3594 super->minfo[id])->state == DSNS_FIND_STATE)
3595 processDSNSResponse(qstate, id, super);
3596 else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
3597 error_supers(qstate, id, super);
3598 else if(qstate->is_priming)
3599 prime_supers(qstate, id, super);
3600 else processTargetResponse(qstate, id, super);
3604 * Handle iterator state.
3605 * Handle events. This is the real processing loop for events, responsible
3606 * for moving events through the various states. If a processing method
3607 * returns true, then it will be advanced to the next state. If false, then
3608 * processing will stop.
3610 * @param qstate: query state.
3611 * @param ie: iterator shared global environment.
3612 * @param iq: iterator query state.
3613 * @param id: module id.
3616 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
3617 struct iter_env* ie, int id)
3621 verbose(VERB_ALGO, "iter_handle processing q with state %s",
3622 iter_state_to_string(iq->state));
3624 case INIT_REQUEST_STATE:
3625 cont = processInitRequest(qstate, iq, ie, id);
3627 case INIT_REQUEST_2_STATE:
3628 cont = processInitRequest2(qstate, iq, id);
3630 case INIT_REQUEST_3_STATE:
3631 cont = processInitRequest3(qstate, iq, id);
3633 case QUERYTARGETS_STATE:
3634 cont = processQueryTargets(qstate, iq, ie, id);
3636 case QUERY_RESP_STATE:
3637 cont = processQueryResponse(qstate, iq, id);
3639 case PRIME_RESP_STATE:
3640 cont = processPrimeResponse(qstate, id);
3642 case COLLECT_CLASS_STATE:
3643 cont = processCollectClass(qstate, id);
3645 case DSNS_FIND_STATE:
3646 cont = processDSNSFind(qstate, iq, id);
3648 case FINISHED_STATE:
3649 cont = processFinished(qstate, iq, id);
3652 log_warn("iterator: invalid state: %d",
3661 * This is the primary entry point for processing request events. Note that
3662 * this method should only be used by external modules.
3663 * @param qstate: query state.
3664 * @param ie: iterator shared global environment.
3665 * @param iq: iterator query state.
3666 * @param id: module id.
3669 process_request(struct module_qstate* qstate, struct iter_qstate* iq,
3670 struct iter_env* ie, int id)
3672 /* external requests start in the INIT state, and finish using the
3673 * FINISHED state. */
3674 iq->state = INIT_REQUEST_STATE;
3675 iq->final_state = FINISHED_STATE;
3676 verbose(VERB_ALGO, "process_request: new external request event");
3677 iter_handle(qstate, iq, ie, id);
3680 /** process authoritative server reply */
3682 process_response(struct module_qstate* qstate, struct iter_qstate* iq,
3683 struct iter_env* ie, int id, struct outbound_entry* outbound,
3684 enum module_ev event)
3686 struct msg_parse* prs;
3687 struct edns_data edns;
3690 verbose(VERB_ALGO, "process_response: new external response event");
3691 iq->response = NULL;
3692 iq->state = QUERY_RESP_STATE;
3693 if(event == module_event_noreply || event == module_event_error) {
3694 if(event == module_event_noreply && iq->timeout_count >= 3 &&
3695 qstate->env->cfg->use_caps_bits_for_id &&
3696 !iq->caps_fallback && !is_caps_whitelisted(ie, iq)) {
3697 /* start fallback */
3698 iq->caps_fallback = 1;
3699 iq->caps_server = 0;
3700 iq->caps_reply = NULL;
3701 iq->caps_response = NULL;
3702 iq->caps_minimisation_state = DONOT_MINIMISE_STATE;
3703 iq->state = QUERYTARGETS_STATE;
3704 iq->num_current_queries--;
3705 /* need fresh attempts for the 0x20 fallback, if
3706 * that was the cause for the failure */
3707 iter_dec_attempts(iq->dp, 3);
3708 verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback");
3713 if( (event != module_event_reply && event != module_event_capsfail)
3714 || !qstate->reply) {
3715 log_err("Bad event combined with response");
3716 outbound_list_remove(&iq->outlist, outbound);
3717 errinf(qstate, "module iterator received wrong internal event with a response message");
3718 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3723 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
3724 sizeof(struct msg_parse));
3726 log_err("out of memory on incoming message");
3727 /* like packet got dropped */
3730 memset(prs, 0, sizeof(*prs));
3731 memset(&edns, 0, sizeof(edns));
3732 pkt = qstate->reply->c->buffer;
3733 sldns_buffer_set_position(pkt, 0);
3734 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
3735 verbose(VERB_ALGO, "parse error on reply packet");
3738 /* edns is not examined, but removed from message to help cache */
3739 if(parse_extract_edns(prs, &edns, qstate->env->scratch) !=
3743 /* Copy the edns options we may got from the back end */
3745 qstate->edns_opts_back_in = edns_opt_copy_region(edns.opt_list,
3747 if(!qstate->edns_opts_back_in) {
3748 log_err("out of memory on incoming message");
3749 /* like packet got dropped */
3752 if(!inplace_cb_edns_back_parsed_call(qstate->env, qstate)) {
3753 log_err("unable to call edns_back_parsed callback");
3758 /* remove CD-bit, we asked for in case we handle validation ourself */
3759 prs->flags &= ~BIT_CD;
3761 /* normalize and sanitize: easy to delete items from linked lists */
3762 if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name,
3763 qstate->env->scratch, qstate->env, ie)) {
3764 /* if 0x20 enabled, start fallback, but we have no message */
3765 if(event == module_event_capsfail && !iq->caps_fallback) {
3766 iq->caps_fallback = 1;
3767 iq->caps_server = 0;
3768 iq->caps_reply = NULL;
3769 iq->caps_response = NULL;
3770 iq->caps_minimisation_state = DONOT_MINIMISE_STATE;
3771 iq->state = QUERYTARGETS_STATE;
3772 iq->num_current_queries--;
3773 verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response");
3778 /* allocate response dns_msg in region */
3779 iq->response = dns_alloc_msg(pkt, prs, qstate->region);
3782 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
3783 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
3784 &qstate->reply->addr, qstate->reply->addrlen);
3785 if(verbosity >= VERB_ALGO)
3786 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
3789 if(event == module_event_capsfail || iq->caps_fallback) {
3790 if(qstate->env->cfg->qname_minimisation &&
3791 iq->minimisation_state != DONOT_MINIMISE_STATE) {
3792 /* Skip QNAME minimisation for next query, since that
3793 * one has to match the current query. */
3794 iq->minimisation_state = SKIP_MINIMISE_STATE;
3796 /* for fallback we care about main answer, not additionals */
3797 /* removing that makes comparison more likely to succeed */
3798 caps_strip_reply(iq->response->rep);
3800 if(iq->caps_fallback &&
3801 iq->caps_minimisation_state != iq->minimisation_state) {
3802 /* QNAME minimisation state has changed, restart caps
3804 iq->caps_fallback = 0;
3807 if(!iq->caps_fallback) {
3808 /* start fallback */
3809 iq->caps_fallback = 1;
3810 iq->caps_server = 0;
3811 iq->caps_reply = iq->response->rep;
3812 iq->caps_response = iq->response;
3813 iq->caps_minimisation_state = iq->minimisation_state;
3814 iq->state = QUERYTARGETS_STATE;
3815 iq->num_current_queries--;
3816 verbose(VERB_DETAIL, "Capsforid: starting fallback");
3819 /* check if reply is the same, otherwise, fail */
3820 if(!iq->caps_reply) {
3821 iq->caps_reply = iq->response->rep;
3822 iq->caps_response = iq->response;
3823 iq->caps_server = -1; /*become zero at ++,
3824 so that we start the full set of trials */
3825 } else if(caps_failed_rcode(iq->caps_reply) &&
3826 !caps_failed_rcode(iq->response->rep)) {
3827 /* prefer to upgrade to non-SERVFAIL */
3828 iq->caps_reply = iq->response->rep;
3829 iq->caps_response = iq->response;
3830 } else if(!caps_failed_rcode(iq->caps_reply) &&
3831 caps_failed_rcode(iq->response->rep)) {
3832 /* if we have non-SERVFAIL as answer then
3833 * we can ignore SERVFAILs for the equality
3835 /* no instructions here, skip other else */
3836 } else if(caps_failed_rcode(iq->caps_reply) &&
3837 caps_failed_rcode(iq->response->rep)) {
3838 /* failure is same as other failure in fallbk*/
3839 /* no instructions here, skip other else */
3840 } else if(!reply_equal(iq->response->rep, iq->caps_reply,
3841 qstate->env->scratch)) {
3842 verbose(VERB_DETAIL, "Capsforid fallback: "
3843 "getting different replies, failed");
3844 outbound_list_remove(&iq->outlist, outbound);
3845 errinf(qstate, "0x20 failed, then got different replies in fallback");
3846 (void)error_response(qstate, id,
3847 LDNS_RCODE_SERVFAIL);
3850 /* continue the fallback procedure at next server */
3852 iq->state = QUERYTARGETS_STATE;
3853 iq->num_current_queries--;
3854 verbose(VERB_DETAIL, "Capsforid: reply is equal. "
3855 "go to next fallback");
3859 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
3862 outbound_list_remove(&iq->outlist, outbound);
3863 iter_handle(qstate, iq, ie, id);
3867 iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
3868 struct outbound_entry* outbound)
3870 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
3871 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3872 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
3873 id, strextstate(qstate->ext_state[id]), strmodulevent(event));
3874 if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
3876 if(iq && qstate->qinfo.qname != iq->qchase.qname)
3877 log_query_info(VERB_QUERY, "iterator operate: chased to",
3880 /* perform iterator state machine */
3881 if((event == module_event_new || event == module_event_pass) &&
3883 if(!iter_new(qstate, id)) {
3884 errinf(qstate, "malloc failure, new iterator module allocation");
3885 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3888 iq = (struct iter_qstate*)qstate->minfo[id];
3889 process_request(qstate, iq, ie, id);
3892 if(iq && event == module_event_pass) {
3893 iter_handle(qstate, iq, ie, id);
3896 if(iq && outbound) {
3897 process_response(qstate, iq, ie, id, outbound, event);
3900 if(event == module_event_error) {
3901 verbose(VERB_ALGO, "got called with event error, giving up");
3902 errinf(qstate, "iterator module got the error event");
3903 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3907 log_err("bad event for iterator");
3908 errinf(qstate, "iterator module received wrong event");
3909 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3913 iter_clear(struct module_qstate* qstate, int id)
3915 struct iter_qstate* iq;
3918 iq = (struct iter_qstate*)qstate->minfo[id];
3920 outbound_list_clear(&iq->outlist);
3921 if(iq->target_count && --iq->target_count[0] == 0)
3922 free(iq->target_count);
3923 iq->num_current_queries = 0;
3925 qstate->minfo[id] = NULL;
3929 iter_get_mem(struct module_env* env, int id)
3931 struct iter_env* ie = (struct iter_env*)env->modinfo[id];
3934 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
3935 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
3939 * The iterator function block
3941 static struct module_func_block iter_block = {
3943 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
3944 &iter_clear, &iter_get_mem
3947 struct module_func_block*
3948 iter_get_funcblock(void)
3954 iter_state_to_string(enum iter_state state)
3958 case INIT_REQUEST_STATE :
3959 return "INIT REQUEST STATE";
3960 case INIT_REQUEST_2_STATE :
3961 return "INIT REQUEST STATE (stage 2)";
3962 case INIT_REQUEST_3_STATE:
3963 return "INIT REQUEST STATE (stage 3)";
3964 case QUERYTARGETS_STATE :
3965 return "QUERY TARGETS STATE";
3966 case PRIME_RESP_STATE :
3967 return "PRIME RESPONSE STATE";
3968 case COLLECT_CLASS_STATE :
3969 return "COLLECT CLASS STATE";
3970 case DSNS_FIND_STATE :
3971 return "DSNS FIND STATE";
3972 case QUERY_RESP_STATE :
3973 return "QUERY RESPONSE STATE";
3974 case FINISHED_STATE :
3975 return "FINISHED RESPONSE STATE";
3977 return "UNKNOWN ITER STATE";
3982 iter_state_is_responsestate(enum iter_state s)
3985 case INIT_REQUEST_STATE :
3986 case INIT_REQUEST_2_STATE :
3987 case INIT_REQUEST_3_STATE :
3988 case QUERYTARGETS_STATE :
3989 case COLLECT_CLASS_STATE :