2 * iterator/iter_utils.c - iterative resolver module utility functions.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 * This file contains functions to assist the iterator module.
40 * Configuration options. Forward zones.
43 #include "iterator/iter_utils.h"
44 #include "iterator/iterator.h"
45 #include "iterator/iter_hints.h"
46 #include "iterator/iter_fwd.h"
47 #include "iterator/iter_donotq.h"
48 #include "iterator/iter_delegpt.h"
49 #include "iterator/iter_priv.h"
50 #include "services/cache/infra.h"
51 #include "services/cache/dns.h"
52 #include "services/cache/rrset.h"
53 #include "util/net_help.h"
54 #include "util/module.h"
56 #include "util/config_file.h"
57 #include "util/regional.h"
58 #include "util/data/msgparse.h"
59 #include "util/data/dname.h"
60 #include "util/random.h"
61 #include "util/fptr_wlist.h"
62 #include "validator/val_anchor.h"
63 #include "validator/val_kcache.h"
64 #include "validator/val_kentry.h"
65 #include "validator/val_utils.h"
66 #include "validator/val_sigcrypt.h"
67 #include "ldns/sbuffer.h"
69 /** time when nameserver glue is said to be 'recent' */
70 #define SUSPICION_RECENT_EXPIRY 86400
71 /** penalty to validation failed blacklisted IPs */
72 #define BLACKLIST_PENALTY (USEFUL_SERVER_TOP_TIMEOUT*4)
74 /** fillup fetch policy array */
76 fetch_fill(struct iter_env* ie, const char* str)
78 char* s = (char*)str, *e;
80 for(i=0; i<ie->max_dependency_depth+1; i++) {
81 ie->target_fetch_policy[i] = strtol(s, &e, 10);
83 fatal_exit("cannot parse fetch policy number %s", s);
88 /** Read config string that represents the target fetch policy */
90 read_fetch_policy(struct iter_env* ie, const char* str)
92 int count = cfg_count_numbers(str);
94 log_err("Cannot parse target fetch policy: \"%s\"", str);
97 ie->max_dependency_depth = count - 1;
98 ie->target_fetch_policy = (int*)calloc(
99 (size_t)ie->max_dependency_depth+1, sizeof(int));
100 if(!ie->target_fetch_policy) {
101 log_err("alloc fetch policy: out of memory");
109 iter_apply_cfg(struct iter_env* iter_env, struct config_file* cfg)
112 /* target fetch policy */
113 if(!read_fetch_policy(iter_env, cfg->target_fetch_policy))
115 for(i=0; i<iter_env->max_dependency_depth+1; i++)
116 verbose(VERB_QUERY, "target fetch policy for level %d is %d",
117 i, iter_env->target_fetch_policy[i]);
119 if(!iter_env->donotq)
120 iter_env->donotq = donotq_create();
121 if(!iter_env->donotq || !donotq_apply_cfg(iter_env->donotq, cfg)) {
122 log_err("Could not set donotqueryaddresses");
126 iter_env->priv = priv_create();
127 if(!iter_env->priv || !priv_apply_cfg(iter_env->priv, cfg)) {
128 log_err("Could not set private addresses");
131 iter_env->supports_ipv6 = cfg->do_ip6;
132 iter_env->supports_ipv4 = cfg->do_ip4;
136 /** filter out unsuitable targets
137 * @param iter_env: iterator environment with ipv6-support flag.
138 * @param env: module environment with infra cache.
139 * @param name: zone name
140 * @param namelen: length of name
141 * @param qtype: query type (host order).
142 * @param now: current time
143 * @param a: address in delegation point we are examining.
144 * @return an integer that signals the target suitability.
146 * -1: The address should be omitted from the list.
148 * o The address is bogus (DNSSEC validation failure).
149 * o Listed as donotquery
150 * o is ipv6 but no ipv6 support (in operating system).
151 * o is ipv4 but no ipv4 support (in operating system).
153 * Otherwise, an rtt in milliseconds.
154 * 0 .. USEFUL_SERVER_TOP_TIMEOUT-1
155 * The roundtrip time timeout estimate. less than 2 minutes.
156 * Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus
157 * values 0 .. 49 are not used, unless that is changed.
158 * USEFUL_SERVER_TOP_TIMEOUT
159 * This value exactly is given for unresponsive blacklisted.
160 * USEFUL_SERVER_TOP_TIMEOUT+1
161 * For non-blacklisted servers: huge timeout, but has traffic.
162 * USEFUL_SERVER_TOP_TIMEOUT*1 ..
163 * parent-side lame servers get this penalty. A dispreferential
164 * server. (lame in delegpt).
165 * USEFUL_SERVER_TOP_TIMEOUT*2 ..
166 * dnsseclame servers get penalty
167 * USEFUL_SERVER_TOP_TIMEOUT*3 ..
168 * recursion lame servers get penalty
169 * UNKNOWN_SERVER_NICENESS
170 * If no information is known about the server, this is
171 * returned. 376 msec or so.
172 * +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs.
174 * When a final value is chosen that is dnsseclame ; dnsseclameness checking
175 * is turned off (so we do not discard the reply).
176 * When a final value is chosen that is recursionlame; RD bit is set on query.
177 * Because of the numbers this means recursionlame also have dnssec lameness
178 * checking turned off.
181 iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env,
182 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
183 struct delegpt_addr* a)
185 int rtt, lame, reclame, dnsseclame;
187 return -1; /* address of server is bogus */
188 if(donotq_lookup(iter_env->donotq, &a->addr, a->addrlen)) {
189 log_addr(VERB_ALGO, "skip addr on the donotquery list",
190 &a->addr, a->addrlen);
191 return -1; /* server is on the donotquery list */
193 if(!iter_env->supports_ipv6 && addr_is_ip6(&a->addr, a->addrlen)) {
194 return -1; /* there is no ip6 available */
196 if(!iter_env->supports_ipv4 && !addr_is_ip6(&a->addr, a->addrlen)) {
197 return -1; /* there is no ip4 available */
199 /* check lameness - need zone , class info */
200 if(infra_get_lame_rtt(env->infra_cache, &a->addr, a->addrlen,
201 name, namelen, qtype, &lame, &dnsseclame, &reclame,
203 log_addr(VERB_ALGO, "servselect", &a->addr, a->addrlen);
204 verbose(VERB_ALGO, " rtt=%d%s%s%s%s", rtt,
206 dnsseclame?" DNSSEC_LAME":"",
207 reclame?" REC_LAME":"",
208 a->lame?" ADDR_LAME":"");
210 return -1; /* server is lame */
211 else if(rtt >= USEFUL_SERVER_TOP_TIMEOUT)
212 /* server is unresponsive,
213 * we used to return TOP_TIMOUT, but fairly useless,
214 * because if == TOP_TIMEOUT is dropped because
215 * blacklisted later, instead, remove it here, so
216 * other choices (that are not blacklisted) can be
219 /* select remainder from worst to best */
221 return rtt+USEFUL_SERVER_TOP_TIMEOUT*3; /* nonpref */
222 else if(dnsseclame || a->dnsseclame)
223 return rtt+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
225 return rtt+USEFUL_SERVER_TOP_TIMEOUT+1; /* nonpref */
228 /* no server information present */
230 return UNKNOWN_SERVER_NICENESS+USEFUL_SERVER_TOP_TIMEOUT*2; /* nonpref */
232 return USEFUL_SERVER_TOP_TIMEOUT+1+UNKNOWN_SERVER_NICENESS; /* nonpref */
233 return UNKNOWN_SERVER_NICENESS;
236 /** lookup RTT information, and also store fastest rtt (if any) */
238 iter_fill_rtt(struct iter_env* iter_env, struct module_env* env,
239 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
240 struct delegpt* dp, int* best_rtt, struct sock_list* blacklist)
243 struct delegpt_addr* a;
245 return 0; /* NS bogus, all bogus, nothing found */
246 for(a=dp->result_list; a; a = a->next_result) {
247 a->sel_rtt = iter_filter_unsuitable(iter_env, env,
248 name, namelen, qtype, now, a);
249 if(a->sel_rtt != -1) {
250 if(sock_list_find(blacklist, &a->addr, a->addrlen))
251 a->sel_rtt += BLACKLIST_PENALTY;
254 *best_rtt = a->sel_rtt;
256 } else if(a->sel_rtt < *best_rtt) {
257 *best_rtt = a->sel_rtt;
264 /** filter the addres list, putting best targets at front,
265 * returns number of best targets (or 0, no suitable targets) */
267 iter_filter_order(struct iter_env* iter_env, struct module_env* env,
268 uint8_t* name, size_t namelen, uint16_t qtype, time_t now,
269 struct delegpt* dp, int* selected_rtt, int open_target,
270 struct sock_list* blacklist)
272 int got_num = 0, low_rtt = 0, swap_to_front;
273 struct delegpt_addr* a, *n, *prev=NULL;
275 /* fillup sel_rtt and find best rtt in the bunch */
276 got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp,
277 &low_rtt, blacklist);
280 if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT &&
281 (delegpt_count_missing_targets(dp) > 0 || open_target > 0)) {
282 verbose(VERB_ALGO, "Bad choices, trying to get more choice");
283 return 0; /* we want more choice. The best choice is a bad one.
284 return 0 to force the caller to fetch more */
290 /* skip unsuitable targets */
291 if(a->sel_rtt == -1) {
296 /* classify the server address and determine what to do */
298 if(a->sel_rtt >= low_rtt && a->sel_rtt - low_rtt <= RTT_BAND) {
301 } else if(a->sel_rtt<low_rtt && low_rtt-a->sel_rtt<=RTT_BAND) {
305 /* swap to front if necessary, or move to next result */
306 if(swap_to_front && prev) {
308 prev->next_result = n;
309 a->next_result = dp->result_list;
317 *selected_rtt = low_rtt;
322 iter_server_selection(struct iter_env* iter_env,
323 struct module_env* env, struct delegpt* dp,
324 uint8_t* name, size_t namelen, uint16_t qtype, int* dnssec_lame,
325 int* chase_to_rd, int open_target, struct sock_list* blacklist)
329 struct delegpt_addr* a, *prev;
330 int num = iter_filter_order(iter_env, env, name, namelen, qtype,
331 *env->now, dp, &selrtt, open_target, blacklist);
335 verbose(VERB_ALGO, "selrtt %d", selrtt);
336 if(selrtt > BLACKLIST_PENALTY) {
337 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*3) {
338 verbose(VERB_ALGO, "chase to "
339 "blacklisted recursion lame server");
342 if(selrtt-BLACKLIST_PENALTY > USEFUL_SERVER_TOP_TIMEOUT*2) {
343 verbose(VERB_ALGO, "chase to "
344 "blacklisted dnssec lame server");
348 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*3) {
349 verbose(VERB_ALGO, "chase to recursion lame server");
352 if(selrtt > USEFUL_SERVER_TOP_TIMEOUT*2) {
353 verbose(VERB_ALGO, "chase to dnssec lame server");
356 if(selrtt == USEFUL_SERVER_TOP_TIMEOUT) {
357 verbose(VERB_ALGO, "chase to blacklisted lame server");
364 if(++a->attempts < OUTBOUND_MSG_RETRY)
366 dp->result_list = a->next_result;
370 /* randomly select a target from the list */
372 /* grab secure random number, to pick unexpected server.
373 * also we need it to be threadsafe. */
374 sel = ub_random_max(env->rnd, num);
377 while(sel > 0 && a) {
382 if(!a) /* robustness */
384 if(++a->attempts < OUTBOUND_MSG_RETRY)
386 /* remove it from the delegation point result list */
388 prev->next_result = a->next_result;
389 else dp->result_list = a->next_result;
394 dns_alloc_msg(sldns_buffer* pkt, struct msg_parse* msg,
395 struct regional* region)
397 struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
398 sizeof(struct dns_msg));
401 memset(m, 0, sizeof(*m));
402 if(!parse_create_msg(pkt, msg, NULL, &m->qinfo, &m->rep, region)) {
403 log_err("malloc failure: allocating incoming dns_msg");
410 dns_copy_msg(struct dns_msg* from, struct regional* region)
412 struct dns_msg* m = (struct dns_msg*)regional_alloc(region,
413 sizeof(struct dns_msg));
416 m->qinfo = from->qinfo;
417 if(!(m->qinfo.qname = regional_alloc_init(region, from->qinfo.qname,
418 from->qinfo.qname_len)))
420 if(!(m->rep = reply_info_copy(from->rep, NULL, region)))
426 iter_dns_store(struct module_env* env, struct query_info* msgqinf,
427 struct reply_info* msgrep, int is_referral, time_t leeway, int pside,
428 struct regional* region)
430 if(!dns_cache_store(env, msgqinf, msgrep, is_referral, leeway,
432 log_err("out of memory: cannot store data in cache");
436 iter_ns_probability(struct ub_randstate* rnd, int n, int m)
439 if(n == m) /* 100% chance */
441 /* we do not need secure random numbers here, but
442 * we do need it to be threadsafe, so we use this */
443 sel = ub_random_max(rnd, m);
447 /** detect dependency cycle for query and target */
449 causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen,
450 uint16_t t, uint16_t c)
452 struct query_info qinf;
454 qinf.qname_len = namelen;
457 fptr_ok(fptr_whitelist_modenv_detect_cycle(
458 qstate->env->detect_cycle));
459 return (*qstate->env->detect_cycle)(qstate, &qinf,
460 (uint16_t)(BIT_RD|BIT_CD), qstate->is_priming);
464 iter_mark_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
466 struct delegpt_ns* ns;
467 for(ns = dp->nslist; ns; ns = ns->next) {
470 /* see if this ns as target causes dependency cycle */
471 if(causes_cycle(qstate, ns->name, ns->namelen,
472 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass) ||
473 causes_cycle(qstate, ns->name, ns->namelen,
474 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
475 log_nametypeclass(VERB_QUERY, "skipping target due "
476 "to dependency cycle (harden-glue: no may "
477 "fix some of the cycles)",
478 ns->name, LDNS_RR_TYPE_A,
479 qstate->qinfo.qclass);
486 iter_mark_pside_cycle_targets(struct module_qstate* qstate, struct delegpt* dp)
488 struct delegpt_ns* ns;
489 for(ns = dp->nslist; ns; ns = ns->next) {
490 if(ns->done_pside4 && ns->done_pside6)
492 /* see if this ns as target causes dependency cycle */
493 if(causes_cycle(qstate, ns->name, ns->namelen,
494 LDNS_RR_TYPE_A, qstate->qinfo.qclass)) {
495 log_nametypeclass(VERB_QUERY, "skipping target due "
496 "to dependency cycle", ns->name,
497 LDNS_RR_TYPE_A, qstate->qinfo.qclass);
500 if(causes_cycle(qstate, ns->name, ns->namelen,
501 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass)) {
502 log_nametypeclass(VERB_QUERY, "skipping target due "
503 "to dependency cycle", ns->name,
504 LDNS_RR_TYPE_AAAA, qstate->qinfo.qclass);
511 iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags,
514 struct delegpt_ns* ns;
517 * o no addresses are provided.
518 * o all NS items are required glue.
521 * o no addresses are provided.
522 * o the query is for one of the nameservers in dp,
523 * and that nameserver is a glue-name for this dp.
527 /* either available or unused targets */
528 if(dp->usable_list || dp->result_list)
531 /* see if query is for one of the nameservers, which is glue */
532 if( (qinfo->qtype == LDNS_RR_TYPE_A ||
533 qinfo->qtype == LDNS_RR_TYPE_AAAA) &&
534 dname_subdomain_c(qinfo->qname, dp->name) &&
535 delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len))
538 for(ns = dp->nslist; ns; ns = ns->next) {
539 if(ns->resolved) /* skip failed targets */
541 if(!dname_subdomain_c(ns->name, dp->name))
542 return 0; /* one address is not required glue */
548 iter_indicates_dnssec(struct module_env* env, struct delegpt* dp,
549 struct dns_msg* msg, uint16_t dclass)
551 struct trust_anchor* a;
552 /* information not available, !env->anchors can be common */
553 if(!env || !env->anchors || !dp || !dp->name)
555 /* a trust anchor exists with this name, RRSIGs expected */
556 if((a=anchor_find(env->anchors, dp->name, dp->namelabs, dp->namelen,
558 lock_basic_unlock(&a->lock);
561 /* see if DS rrset was given, in AUTH section */
562 if(msg && msg->rep &&
563 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
564 LDNS_RR_TYPE_DS, dclass))
566 /* look in key cache */
568 struct key_entry_key* kk = key_cache_obtain(env->key_cache,
569 dp->name, dp->namelen, dclass, env->scratch, *env->now);
571 if(query_dname_compare(kk->name, dp->name) == 0) {
572 if(key_entry_isgood(kk) || key_entry_isbad(kk)) {
573 regional_free_all(env->scratch);
575 } else if(key_entry_isnull(kk)) {
576 regional_free_all(env->scratch);
580 regional_free_all(env->scratch);
587 iter_msg_has_dnssec(struct dns_msg* msg)
590 if(!msg || !msg->rep)
592 for(i=0; i<msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
593 if(((struct packed_rrset_data*)msg->rep->rrsets[i]->
594 entry.data)->rrsig_count > 0)
597 /* empty message has no DNSSEC info, with DNSSEC the reply is
598 * not empty (NSEC) */
602 int iter_msg_from_zone(struct dns_msg* msg, struct delegpt* dp,
603 enum response_type type, uint16_t dclass)
605 if(!msg || !dp || !msg->rep || !dp->name)
607 /* SOA RRset - always from reply zone */
608 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
609 LDNS_RR_TYPE_SOA, dclass) ||
610 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
611 LDNS_RR_TYPE_SOA, dclass))
613 if(type == RESPONSE_TYPE_REFERRAL) {
615 /* if it adds a single label, i.e. we expect .com,
616 * and referral to example.com. NS ... , then origin zone
617 * is .com. For a referral to sub.example.com. NS ... then
618 * we do not know, since example.com. may be in between. */
619 for(i=0; i<msg->rep->an_numrrsets+msg->rep->ns_numrrsets;
621 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
622 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NS &&
623 ntohs(s->rk.rrset_class) == dclass) {
624 int l = dname_count_labels(s->rk.dname);
625 if(l == dp->namelabs + 1 &&
626 dname_strict_subdomain(s->rk.dname,
627 l, dp->name, dp->namelabs))
633 log_assert(type==RESPONSE_TYPE_ANSWER || type==RESPONSE_TYPE_CNAME);
634 /* not a referral, and not lame delegation (upwards), so,
635 * any NS rrset must be from the zone itself */
636 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
637 LDNS_RR_TYPE_NS, dclass) ||
638 reply_find_rrset_section_ns(msg->rep, dp->name, dp->namelen,
639 LDNS_RR_TYPE_NS, dclass))
641 /* a DNSKEY set is expected at the zone apex as well */
642 /* this is for 'minimal responses' for DNSKEYs */
643 if(reply_find_rrset_section_an(msg->rep, dp->name, dp->namelen,
644 LDNS_RR_TYPE_DNSKEY, dclass))
650 * check equality of two rrsets
653 * @return true if equal
656 rrset_equal(struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2)
658 struct packed_rrset_data* d1 = (struct packed_rrset_data*)
660 struct packed_rrset_data* d2 = (struct packed_rrset_data*)
663 if(k1->rk.dname_len != k2->rk.dname_len ||
664 k1->rk.flags != k2->rk.flags ||
665 k1->rk.type != k2->rk.type ||
666 k1->rk.rrset_class != k2->rk.rrset_class ||
667 query_dname_compare(k1->rk.dname, k2->rk.dname) != 0)
669 if(d1->ttl != d2->ttl ||
670 d1->count != d2->count ||
671 d1->rrsig_count != d2->rrsig_count ||
672 d1->trust != d2->trust ||
673 d1->security != d2->security)
675 t = d1->count + d1->rrsig_count;
677 if(d1->rr_len[i] != d2->rr_len[i] ||
678 d1->rr_ttl[i] != d2->rr_ttl[i] ||
679 memcmp(d1->rr_data[i], d2->rr_data[i],
687 reply_equal(struct reply_info* p, struct reply_info* q, struct regional* region)
690 if(p->flags != q->flags ||
691 p->qdcount != q->qdcount ||
693 p->prefetch_ttl != q->prefetch_ttl ||
694 p->security != q->security ||
695 p->an_numrrsets != q->an_numrrsets ||
696 p->ns_numrrsets != q->ns_numrrsets ||
697 p->ar_numrrsets != q->ar_numrrsets ||
698 p->rrset_count != q->rrset_count)
700 for(i=0; i<p->rrset_count; i++) {
701 if(!rrset_equal(p->rrsets[i], q->rrsets[i])) {
702 if(!rrset_canonical_equal(region, p->rrsets[i],
704 regional_free_all(region);
707 regional_free_all(region);
714 iter_store_parentside_rrset(struct module_env* env,
715 struct ub_packed_rrset_key* rrset)
717 struct rrset_ref ref;
718 rrset = packed_rrset_copy_alloc(rrset, env->alloc, *env->now);
720 log_err("malloc failure in store_parentside_rrset");
723 rrset->rk.flags |= PACKED_RRSET_PARENT_SIDE;
724 rrset->entry.hash = rrset_key_hash(&rrset->rk);
727 /* ignore ret: if it was in the cache, ref updated */
728 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, *env->now);
731 /** fetch NS record from reply, if any */
732 static struct ub_packed_rrset_key*
733 reply_get_NS_rrset(struct reply_info* rep)
736 for(i=0; i<rep->rrset_count; i++) {
737 if(rep->rrsets[i]->rk.type == htons(LDNS_RR_TYPE_NS)) {
738 return rep->rrsets[i];
745 iter_store_parentside_NS(struct module_env* env, struct reply_info* rep)
747 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
749 log_rrset_key(VERB_ALGO, "store parent-side NS", rrset);
750 iter_store_parentside_rrset(env, rrset);
754 void iter_store_parentside_neg(struct module_env* env,
755 struct query_info* qinfo, struct reply_info* rep)
757 /* TTL: NS from referral in iq->deleg_msg,
758 * or first RR from iq->response,
759 * or servfail5secs if !iq->response */
760 time_t ttl = NORR_TTL;
761 struct ub_packed_rrset_key* neg;
762 struct packed_rrset_data* newd;
764 struct ub_packed_rrset_key* rrset = reply_get_NS_rrset(rep);
765 if(!rrset && rep->rrset_count != 0) rrset = rep->rrsets[0];
766 if(rrset) ttl = ub_packed_rrset_ttl(rrset);
768 /* create empty rrset to store */
769 neg = (struct ub_packed_rrset_key*)regional_alloc(env->scratch,
770 sizeof(struct ub_packed_rrset_key));
772 log_err("out of memory in store_parentside_neg");
775 memset(&neg->entry, 0, sizeof(neg->entry));
776 neg->entry.key = neg;
777 neg->rk.type = htons(qinfo->qtype);
778 neg->rk.rrset_class = htons(qinfo->qclass);
780 neg->rk.dname = regional_alloc_init(env->scratch, qinfo->qname,
783 log_err("out of memory in store_parentside_neg");
786 neg->rk.dname_len = qinfo->qname_len;
787 neg->entry.hash = rrset_key_hash(&neg->rk);
788 newd = (struct packed_rrset_data*)regional_alloc_zero(env->scratch,
789 sizeof(struct packed_rrset_data) + sizeof(size_t) +
790 sizeof(uint8_t*) + sizeof(time_t) + sizeof(uint16_t));
792 log_err("out of memory in store_parentside_neg");
795 neg->entry.data = newd;
797 /* entry must have one RR, otherwise not valid in cache.
798 * put in one RR with empty rdata: those are ignored as nameserver */
800 newd->rrsig_count = 0;
801 newd->trust = rrset_trust_ans_noAA;
802 newd->rr_len = (size_t*)((uint8_t*)newd +
803 sizeof(struct packed_rrset_data));
804 newd->rr_len[0] = 0 /* zero len rdata */ + sizeof(uint16_t);
805 packed_rrset_ptr_fixup(newd);
806 newd->rr_ttl[0] = newd->ttl;
807 sldns_write_uint16(newd->rr_data[0], 0 /* zero len rdata */);
809 log_rrset_key(VERB_ALGO, "store parent-side negative", neg);
810 iter_store_parentside_rrset(env, neg);
814 iter_lookup_parent_NS_from_cache(struct module_env* env, struct delegpt* dp,
815 struct regional* region, struct query_info* qinfo)
817 struct ub_packed_rrset_key* akey;
818 akey = rrset_cache_lookup(env->rrset_cache, dp->name,
819 dp->namelen, LDNS_RR_TYPE_NS, qinfo->qclass,
820 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
822 log_rrset_key(VERB_ALGO, "found parent-side NS in cache", akey);
823 dp->has_parent_side_NS = 1;
824 /* and mark the new names as lame */
825 if(!delegpt_rrset_add_ns(dp, region, akey, 1)) {
826 lock_rw_unlock(&akey->entry.lock);
829 lock_rw_unlock(&akey->entry.lock);
834 int iter_lookup_parent_glue_from_cache(struct module_env* env,
835 struct delegpt* dp, struct regional* region, struct query_info* qinfo)
837 struct ub_packed_rrset_key* akey;
838 struct delegpt_ns* ns;
839 size_t num = delegpt_count_targets(dp);
840 for(ns = dp->nslist; ns; ns = ns->next) {
841 /* get cached parentside A */
842 akey = rrset_cache_lookup(env->rrset_cache, ns->name,
843 ns->namelen, LDNS_RR_TYPE_A, qinfo->qclass,
844 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
846 log_rrset_key(VERB_ALGO, "found parent-side", akey);
848 /* a negative-cache-element has no addresses it adds */
849 if(!delegpt_add_rrset_A(dp, region, akey, 1))
850 log_err("malloc failure in lookup_parent_glue");
851 lock_rw_unlock(&akey->entry.lock);
853 /* get cached parentside AAAA */
854 akey = rrset_cache_lookup(env->rrset_cache, ns->name,
855 ns->namelen, LDNS_RR_TYPE_AAAA, qinfo->qclass,
856 PACKED_RRSET_PARENT_SIDE, *env->now, 0);
858 log_rrset_key(VERB_ALGO, "found parent-side", akey);
860 /* a negative-cache-element has no addresses it adds */
861 if(!delegpt_add_rrset_AAAA(dp, region, akey, 1))
862 log_err("malloc failure in lookup_parent_glue");
863 lock_rw_unlock(&akey->entry.lock);
866 /* see if new (but lame) addresses have become available */
867 return delegpt_count_targets(dp) != num;
871 iter_get_next_root(struct iter_hints* hints, struct iter_forwards* fwd,
874 uint16_t c1 = *c, c2 = *c;
875 int r1 = hints_next_root(hints, &c1);
876 int r2 = forwards_next_root(fwd, &c2);
877 if(!r1 && !r2) /* got none, end of list */
879 else if(!r1) /* got one, return that */
883 else if(c1 < c2) /* got both take smallest */
890 iter_scrub_ds(struct dns_msg* msg, struct ub_packed_rrset_key* ns, uint8_t* z)
892 /* Only the DS record for the delegation itself is expected.
893 * We allow DS for everything between the bailiwick and the
894 * zonecut, thus DS records must be at or above the zonecut.
895 * And the DS records must be below the server authority zone.
896 * The answer section is already scrubbed. */
897 size_t i = msg->rep->an_numrrsets;
898 while(i < (msg->rep->an_numrrsets + msg->rep->ns_numrrsets)) {
899 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
900 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS &&
901 (!ns || !dname_subdomain_c(ns->rk.dname, s->rk.dname)
902 || query_dname_compare(z, s->rk.dname) == 0)) {
903 log_nametypeclass(VERB_ALGO, "removing irrelevant DS",
904 s->rk.dname, ntohs(s->rk.type),
905 ntohs(s->rk.rrset_class));
906 memmove(msg->rep->rrsets+i, msg->rep->rrsets+i+1,
907 sizeof(struct ub_packed_rrset_key*) *
908 (msg->rep->rrset_count-i-1));
909 msg->rep->ns_numrrsets--;
910 msg->rep->rrset_count--;
911 /* stay at same i, but new record */
918 void iter_dec_attempts(struct delegpt* dp, int d)
920 struct delegpt_addr* a;
921 for(a=dp->target_list; a; a = a->next_target) {
922 if(a->attempts >= OUTBOUND_MSG_RETRY) {
923 /* add back to result list */
924 a->next_result = dp->result_list;
929 else a->attempts = 0;
933 void iter_merge_retry_counts(struct delegpt* dp, struct delegpt* old)
935 struct delegpt_addr* a, *o, *prev;
936 for(a=dp->target_list; a; a = a->next_target) {
937 o = delegpt_find_addr(old, &a->addr, a->addrlen);
939 log_addr(VERB_ALGO, "copy attempt count previous dp",
940 &a->addr, a->addrlen);
941 a->attempts = o->attempts;
947 if(a->attempts >= OUTBOUND_MSG_RETRY) {
948 log_addr(VERB_ALGO, "remove from usable list dp",
949 &a->addr, a->addrlen);
950 /* remove from result list */
952 prev->next_usable = a->next_usable;
953 else dp->usable_list = a->next_usable;
954 /* prev stays the same */
964 iter_ds_toolow(struct dns_msg* msg, struct delegpt* dp)
966 /* if for query example.com, there is example.com SOA or a subdomain
967 * of example.com, then we are too low and need to fetch NS. */
969 /* if we have a DNAME or CNAME we are probably wrong */
970 /* if we have a qtype DS in the answer section, its fine */
971 for(i=0; i < msg->rep->an_numrrsets; i++) {
972 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
973 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DNAME ||
974 ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME) {
975 /* not the right answer, maybe too low, check the
976 * RRSIG signer name (if there is any) for a hint
977 * that it is from the dp zone anyway */
980 val_find_rrset_signer(s, &sname, &slen);
981 if(sname && query_dname_compare(dp->name, sname)==0)
982 return 0; /* it is fine, from the right dp */
985 if(ntohs(s->rk.type) == LDNS_RR_TYPE_DS)
986 return 0; /* fine, we have a DS record */
988 for(i=msg->rep->an_numrrsets;
989 i < msg->rep->an_numrrsets + msg->rep->ns_numrrsets; i++) {
990 struct ub_packed_rrset_key* s = msg->rep->rrsets[i];
991 if(ntohs(s->rk.type) == LDNS_RR_TYPE_SOA) {
992 if(dname_subdomain_c(s->rk.dname, msg->qinfo.qname))
993 return 1; /* point is too low */
994 if(query_dname_compare(s->rk.dname, dp->name)==0)
995 return 0; /* right dp */
997 if(ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC ||
998 ntohs(s->rk.type) == LDNS_RR_TYPE_NSEC3) {
1001 val_find_rrset_signer(s, &sname, &slen);
1002 if(sname && query_dname_compare(dp->name, sname)==0)
1003 return 0; /* it is fine, from the right dp */
1007 /* we do not know */
1011 int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp)
1013 /* no delegation point, do not see how we can go down,
1014 * robust check, it should really exist */
1017 /* see if dp equals the qname, then we cannot go down further */
1018 if(query_dname_compare(qinfo->qname, dp->name) == 0)
1020 /* if dp is one label above the name we also cannot go down further */
1021 if(dname_count_labels(qinfo->qname) == dp->namelabs+1)