2 * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003 Internet Software Consortium.
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
18 /* $Id: resolver.c,v 1.355.12.44.2.1 2009/11/18 23:41:18 marka Exp $ */
24 #include <isc/platform.h>
25 #include <isc/print.h>
26 #include <isc/string.h>
27 #include <isc/random.h>
29 #include <isc/stats.h>
30 #include <isc/timer.h>
35 #include <dns/cache.h>
37 #include <dns/dispatch.h>
39 #include <dns/events.h>
40 #include <dns/forward.h>
41 #include <dns/keytable.h>
43 #include <dns/message.h>
44 #include <dns/ncache.h>
45 #include <dns/opcode.h>
48 #include <dns/rcode.h>
49 #include <dns/rdata.h>
50 #include <dns/rdataclass.h>
51 #include <dns/rdatalist.h>
52 #include <dns/rdataset.h>
53 #include <dns/rdatastruct.h>
54 #include <dns/rdatatype.h>
55 #include <dns/resolver.h>
56 #include <dns/result.h>
57 #include <dns/rootns.h>
58 #include <dns/stats.h>
60 #include <dns/validator.h>
62 #define DNS_RESOLVER_TRACE
63 #ifdef DNS_RESOLVER_TRACE
64 #define RTRACE(m) isc_log_write(dns_lctx, \
65 DNS_LOGCATEGORY_RESOLVER, \
66 DNS_LOGMODULE_RESOLVER, \
68 "res %p: %s", res, (m))
69 #define RRTRACE(r, m) isc_log_write(dns_lctx, \
70 DNS_LOGCATEGORY_RESOLVER, \
71 DNS_LOGMODULE_RESOLVER, \
73 "res %p: %s", (r), (m))
74 #define FCTXTRACE(m) isc_log_write(dns_lctx, \
75 DNS_LOGCATEGORY_RESOLVER, \
76 DNS_LOGMODULE_RESOLVER, \
78 "fctx %p(%s'): %s", fctx, fctx->info, (m))
79 #define FCTXTRACE2(m1, m2) \
80 isc_log_write(dns_lctx, \
81 DNS_LOGCATEGORY_RESOLVER, \
82 DNS_LOGMODULE_RESOLVER, \
84 "fctx %p(%s): %s %s", \
85 fctx, fctx->info, (m1), (m2))
86 #define FTRACE(m) isc_log_write(dns_lctx, \
87 DNS_LOGCATEGORY_RESOLVER, \
88 DNS_LOGMODULE_RESOLVER, \
90 "fetch %p (fctx %p(%s)): %s", \
91 fetch, fetch->private, \
92 fetch->private->info, (m))
93 #define QTRACE(m) isc_log_write(dns_lctx, \
94 DNS_LOGCATEGORY_RESOLVER, \
95 DNS_LOGMODULE_RESOLVER, \
97 "resquery %p (fctx %p(%s)): %s", \
99 query->fctx->info, (m))
102 #define RRTRACE(r, m)
109 * Maximum EDNS0 input packet size.
111 #define RECV_BUFFER_SIZE 4096 /* XXXRTH Constant. */
114 * This defines the maximum number of timeouts we will permit before we
115 * disable EDNS0 on the query.
117 #define MAX_EDNS0_TIMEOUTS 3
119 typedef struct fetchctx fetchctx_t;
121 typedef struct query {
122 /* Locked by task event serialization. */
126 dns_dispatchmgr_t * dispatchmgr;
127 dns_dispatch_t * dispatch;
128 isc_boolean_t exclusivesocket;
129 dns_adbaddrinfo_t * addrinfo;
130 isc_socket_t * tcpsocket;
133 dns_dispentry_t * dispentry;
134 ISC_LINK(struct query) link;
137 dns_tsigkey_t *tsigkey;
138 unsigned int options;
139 unsigned int attributes;
141 unsigned int connects;
142 unsigned char data[512];
145 #define QUERY_MAGIC ISC_MAGIC('Q', '!', '!', '!')
146 #define VALID_QUERY(query) ISC_MAGIC_VALID(query, QUERY_MAGIC)
148 #define RESQUERY_ATTR_CANCELED 0x02
150 #define RESQUERY_CONNECTING(q) ((q)->connects > 0)
151 #define RESQUERY_CANCELED(q) (((q)->attributes & \
152 RESQUERY_ATTR_CANCELED) != 0)
153 #define RESQUERY_SENDING(q) ((q)->sends > 0)
156 fetchstate_init = 0, /*%< Start event has not run yet. */
158 fetchstate_done /*%< FETCHDONE events posted. */
162 badns_unreachable = 0,
170 dns_resolver_t * res;
172 dns_rdatatype_t type;
173 unsigned int options;
174 unsigned int bucketnum;
176 /*% Locked by appropriate bucket lock. */
178 isc_boolean_t want_shutdown;
179 isc_boolean_t cloned;
180 isc_boolean_t spilled;
181 unsigned int references;
182 isc_event_t control_event;
183 ISC_LINK(struct fetchctx) link;
184 ISC_LIST(dns_fetchevent_t) events;
185 /*% Locked by task event serialization. */
187 dns_rdataset_t nameservers;
188 unsigned int attributes;
191 isc_interval_t interval;
192 dns_message_t * qmessage;
193 dns_message_t * rmessage;
194 ISC_LIST(resquery_t) queries;
195 dns_adbfindlist_t finds;
196 dns_adbfind_t * find;
197 dns_adbfindlist_t altfinds;
198 dns_adbfind_t * altfind;
199 dns_adbaddrinfolist_t forwaddrs;
200 dns_adbaddrinfolist_t altaddrs;
201 isc_sockaddrlist_t forwarders;
202 dns_fwdpolicy_t fwdpolicy;
203 isc_sockaddrlist_t bad;
204 isc_sockaddrlist_t edns;
205 isc_sockaddrlist_t edns512;
206 dns_validator_t *validator;
207 ISC_LIST(dns_validator_t) validators;
212 * The number of events we're waiting for.
214 unsigned int pending;
217 * The number of times we've "restarted" the current
218 * nameserver set. This acts as a failsafe to prevent
219 * us from pounding constantly on a particular set of
220 * servers that, for whatever reason, are not giving
221 * us useful responses, but are responding in such a
222 * way that they are not marked "bad".
224 unsigned int restarts;
227 * The number of timeouts that have occurred since we
228 * last successfully received a response packet. This
229 * is used for EDNS0 black hole detection.
231 unsigned int timeouts;
234 * Look aside state for DS lookups.
237 dns_fetch_t * nsfetch;
238 dns_rdataset_t nsrrset;
241 * Number of queries that reference this context.
243 unsigned int nqueries;
246 * The reason to print when logging a successful
247 * response to a query.
252 * Fetch-local statistics for detailed logging.
254 isc_result_t result; /*%< fetch result */
255 isc_result_t vresult; /*%< validation result */
258 isc_uint64_t duration;
259 isc_boolean_t logged;
260 unsigned int querysent;
261 unsigned int referrals;
262 unsigned int lamecount;
264 unsigned int badresp;
266 unsigned int findfail;
267 unsigned int valfail;
268 isc_boolean_t timeout;
271 #define FCTX_MAGIC ISC_MAGIC('F', '!', '!', '!')
272 #define VALID_FCTX(fctx) ISC_MAGIC_VALID(fctx, FCTX_MAGIC)
274 #define FCTX_ATTR_HAVEANSWER 0x0001
275 #define FCTX_ATTR_GLUING 0x0002
276 #define FCTX_ATTR_ADDRWAIT 0x0004
277 #define FCTX_ATTR_SHUTTINGDOWN 0x0008
278 #define FCTX_ATTR_WANTCACHE 0x0010
279 #define FCTX_ATTR_WANTNCACHE 0x0020
280 #define FCTX_ATTR_NEEDEDNS0 0x0040
281 #define FCTX_ATTR_TRIEDFIND 0x0080
282 #define FCTX_ATTR_TRIEDALT 0x0100
284 #define HAVE_ANSWER(f) (((f)->attributes & FCTX_ATTR_HAVEANSWER) != \
286 #define GLUING(f) (((f)->attributes & FCTX_ATTR_GLUING) != \
288 #define ADDRWAIT(f) (((f)->attributes & FCTX_ATTR_ADDRWAIT) != \
290 #define SHUTTINGDOWN(f) (((f)->attributes & FCTX_ATTR_SHUTTINGDOWN) \
292 #define WANTCACHE(f) (((f)->attributes & FCTX_ATTR_WANTCACHE) != 0)
293 #define WANTNCACHE(f) (((f)->attributes & FCTX_ATTR_WANTNCACHE) != 0)
294 #define NEEDEDNS0(f) (((f)->attributes & FCTX_ATTR_NEEDEDNS0) != 0)
295 #define TRIEDFIND(f) (((f)->attributes & FCTX_ATTR_TRIEDFIND) != 0)
296 #define TRIEDALT(f) (((f)->attributes & FCTX_ATTR_TRIEDALT) != 0)
299 dns_adbaddrinfo_t * addrinfo;
305 fetchctx_t * private;
308 #define DNS_FETCH_MAGIC ISC_MAGIC('F', 't', 'c', 'h')
309 #define DNS_FETCH_VALID(fetch) ISC_MAGIC_VALID(fetch, DNS_FETCH_MAGIC)
311 typedef struct fctxbucket {
314 ISC_LIST(fetchctx_t) fctxs;
315 isc_boolean_t exiting;
319 typedef struct alternate {
320 isc_boolean_t isaddress;
328 ISC_LINK(struct alternate) link;
331 struct dns_resolver {
337 isc_mutex_t primelock;
338 dns_rdataclass_t rdclass;
339 isc_socketmgr_t * socketmgr;
340 isc_timermgr_t * timermgr;
341 isc_taskmgr_t * taskmgr;
343 isc_boolean_t frozen;
344 unsigned int options;
345 dns_dispatchmgr_t * dispatchmgr;
346 dns_dispatch_t * dispatchv4;
347 isc_boolean_t exclusivev4;
348 dns_dispatch_t * dispatchv6;
349 isc_boolean_t exclusivev6;
351 unsigned int nbuckets;
352 fctxbucket_t * buckets;
353 isc_uint32_t lame_ttl;
354 ISC_LIST(alternate_t) alternates;
355 isc_uint16_t udpsize;
357 isc_rwlock_t alglock;
359 dns_rbt_t * algorithms;
361 isc_rwlock_t mbslock;
363 dns_rbt_t * mustbesecure;
364 unsigned int spillatmax;
365 unsigned int spillatmin;
366 isc_timer_t * spillattimer;
367 isc_boolean_t zero_no_soa_ttl;
369 /* Locked by lock. */
370 unsigned int references;
371 isc_boolean_t exiting;
372 isc_eventlist_t whenshutdown;
373 unsigned int activebuckets;
374 isc_boolean_t priming;
375 unsigned int spillat; /* clients-per-query */
376 unsigned int nextdisp;
377 /* Locked by primelock. */
378 dns_fetch_t * primefetch;
379 /* Locked by nlock. */
383 #define RES_MAGIC ISC_MAGIC('R', 'e', 's', '!')
384 #define VALID_RESOLVER(res) ISC_MAGIC_VALID(res, RES_MAGIC)
387 * Private addrinfo flags. These must not conflict with DNS_FETCHOPT_NOEDNS0,
388 * which we also use as an addrinfo flag.
390 #define FCTX_ADDRINFO_MARK 0x0001
391 #define FCTX_ADDRINFO_FORWARDER 0x1000
392 #define UNMARKED(a) (((a)->flags & FCTX_ADDRINFO_MARK) \
394 #define ISFORWARDER(a) (((a)->flags & \
395 FCTX_ADDRINFO_FORWARDER) != 0)
397 #define NXDOMAIN(r) (((r)->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0)
399 static void destroy(dns_resolver_t *res);
400 static void empty_bucket(dns_resolver_t *res);
401 static isc_result_t resquery_send(resquery_t *query);
402 static void resquery_response(isc_task_t *task, isc_event_t *event);
403 static void resquery_connected(isc_task_t *task, isc_event_t *event);
404 static void fctx_try(fetchctx_t *fctx, isc_boolean_t retrying);
405 static isc_boolean_t fctx_destroy(fetchctx_t *fctx);
406 static isc_result_t ncache_adderesult(dns_message_t *message,
407 dns_db_t *cache, dns_dbnode_t *node,
408 dns_rdatatype_t covers,
409 isc_stdtime_t now, dns_ttl_t maxttl,
410 dns_rdataset_t *ardataset,
411 isc_result_t *eresultp);
412 static void validated(isc_task_t *task, isc_event_t *event);
413 static void maybe_destroy(fetchctx_t *fctx);
414 static void add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
415 isc_result_t reason, badnstype_t badtype);
418 * Increment resolver-related statistics counters.
421 inc_stats(dns_resolver_t *res, isc_statscounter_t counter) {
422 if (res->view->resstats != NULL)
423 isc_stats_increment(res->view->resstats, counter);
427 valcreate(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, dns_name_t *name,
428 dns_rdatatype_t type, dns_rdataset_t *rdataset,
429 dns_rdataset_t *sigrdataset, unsigned int valoptions,
432 dns_validator_t *validator = NULL;
433 dns_valarg_t *valarg;
436 valarg = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
439 return (ISC_R_NOMEMORY);
442 valarg->addrinfo = addrinfo;
444 if (!ISC_LIST_EMPTY(fctx->validators))
445 INSIST((valoptions & DNS_VALIDATOR_DEFER) != 0);
447 result = dns_validator_create(fctx->res->view, name, type, rdataset,
448 sigrdataset, fctx->rmessage,
449 valoptions, task, validated, valarg,
451 if (result == ISC_R_SUCCESS) {
452 inc_stats(fctx->res, dns_resstatscounter_val);
453 if ((valoptions & DNS_VALIDATOR_DEFER) == 0) {
454 INSIST(fctx->validator == NULL);
455 fctx->validator = validator;
457 ISC_LIST_APPEND(fctx->validators, validator, link);
459 isc_mem_put(fctx->res->buckets[fctx->bucketnum].mctx,
460 valarg, sizeof(*valarg));
465 rrsig_fromchildzone(fetchctx_t *fctx, dns_rdataset_t *rdataset) {
466 dns_namereln_t namereln;
467 dns_rdata_rrsig_t rrsig;
468 dns_rdata_t rdata = DNS_RDATA_INIT;
473 for (result = dns_rdataset_first(rdataset);
474 result == ISC_R_SUCCESS;
475 result = dns_rdataset_next(rdataset)) {
476 dns_rdataset_current(rdataset, &rdata);
477 result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
478 RUNTIME_CHECK(result == ISC_R_SUCCESS);
479 namereln = dns_name_fullcompare(&rrsig.signer, &fctx->domain,
481 if (namereln == dns_namereln_subdomain)
483 dns_rdata_reset(&rdata);
489 fix_mustbedelegationornxdomain(dns_message_t *message, fetchctx_t *fctx) {
491 dns_name_t *domain = &fctx->domain;
492 dns_rdataset_t *rdataset;
493 dns_rdatatype_t type;
495 isc_boolean_t keep_auth = ISC_FALSE;
497 if (message->rcode == dns_rcode_nxdomain)
501 * A DS RRset can appear anywhere in a zone, even for a delegation-only
502 * zone. So a response to an explicit query for this type should be
503 * excluded from delegation-only fixup.
505 * SOA, NS, and DNSKEY can only exist at a zone apex, so a postive
506 * response to a query for these types can never violate the
507 * delegation-only assumption: if the query name is below a
508 * zone cut, the response should normally be a referral, which should
509 * be accepted; if the query name is below a zone cut but the server
510 * happens to have authority for the zone of the query name, the
511 * response is a (non-referral) answer. But this does not violate
512 * delegation-only because the query name must be in a different zone
513 * due to the "apex-only" nature of these types. Note that if the
514 * remote server happens to have authority for a child zone of a
515 * delegation-only zone, we may still incorrectly "fix" the response
516 * with NXDOMAIN for queries for other types. Unfortunately it's
517 * generally impossible to differentiate this case from violation of
518 * the delegation-only assumption. Once the resolver learns the
519 * correct zone cut, possibly via a separate query for an "apex-only"
520 * type, queries for other types will be resolved correctly.
522 * A query for type ANY will be accepted if it hits an exceptional
523 * type above in the answer section as it should be from a child
526 * Also accept answers with RRSIG records from the child zone.
527 * Direct queries for RRSIG records should not be answered from
531 if (message->counts[DNS_SECTION_ANSWER] != 0 &&
532 (fctx->type == dns_rdatatype_ns ||
533 fctx->type == dns_rdatatype_ds ||
534 fctx->type == dns_rdatatype_soa ||
535 fctx->type == dns_rdatatype_any ||
536 fctx->type == dns_rdatatype_rrsig ||
537 fctx->type == dns_rdatatype_dnskey)) {
538 result = dns_message_firstname(message, DNS_SECTION_ANSWER);
539 while (result == ISC_R_SUCCESS) {
541 dns_message_currentname(message, DNS_SECTION_ANSWER,
543 for (rdataset = ISC_LIST_HEAD(name->list);
545 rdataset = ISC_LIST_NEXT(rdataset, link)) {
546 if (!dns_name_equal(name, &fctx->name))
548 type = rdataset->type;
552 if (type == dns_rdatatype_rrsig &&
553 rrsig_fromchildzone(fctx, rdataset))
556 * Direct query for apex records or DS.
558 if (fctx->type == type &&
559 (type == dns_rdatatype_ds ||
560 type == dns_rdatatype_ns ||
561 type == dns_rdatatype_soa ||
562 type == dns_rdatatype_dnskey))
565 * Indirect query for apex records or DS.
567 if (fctx->type == dns_rdatatype_any &&
568 (type == dns_rdatatype_ns ||
569 type == dns_rdatatype_ds ||
570 type == dns_rdatatype_soa ||
571 type == dns_rdatatype_dnskey))
574 result = dns_message_nextname(message,
580 * A NODATA response to a DS query?
582 if (fctx->type == dns_rdatatype_ds &&
583 message->counts[DNS_SECTION_ANSWER] == 0)
586 /* Look for referral or indication of answer from child zone? */
587 if (message->counts[DNS_SECTION_AUTHORITY] == 0)
590 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
591 while (result == ISC_R_SUCCESS) {
593 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
594 for (rdataset = ISC_LIST_HEAD(name->list);
596 rdataset = ISC_LIST_NEXT(rdataset, link)) {
597 type = rdataset->type;
598 if (type == dns_rdatatype_soa &&
599 dns_name_equal(name, domain))
600 keep_auth = ISC_TRUE;
602 if (type != dns_rdatatype_ns &&
603 type != dns_rdatatype_soa &&
604 type != dns_rdatatype_rrsig)
607 if (type == dns_rdatatype_rrsig) {
608 if (rrsig_fromchildzone(fctx, rdataset))
614 /* NS or SOA records. */
615 if (dns_name_equal(name, domain)) {
617 * If a query for ANY causes a negative
618 * response, we can be sure that this is
619 * an empty node. For other type of queries
620 * we cannot differentiate an empty node
621 * from a node that just doesn't have that
622 * type of record. We only accept the former
625 if (message->counts[DNS_SECTION_ANSWER] == 0 &&
626 fctx->type == dns_rdatatype_any)
628 } else if (dns_name_issubdomain(name, domain)) {
629 /* Referral or answer from child zone. */
633 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
637 message->rcode = dns_rcode_nxdomain;
638 message->counts[DNS_SECTION_ANSWER] = 0;
640 message->counts[DNS_SECTION_AUTHORITY] = 0;
641 message->counts[DNS_SECTION_ADDITIONAL] = 0;
645 static inline isc_result_t
646 fctx_starttimer(fetchctx_t *fctx) {
648 * Start the lifetime timer for fctx.
650 * This is also used for stopping the idle timer; in that
651 * case we must purge events already posted to ensure that
652 * no further idle events are delivered.
654 return (isc_timer_reset(fctx->timer, isc_timertype_once,
655 &fctx->expires, NULL, ISC_TRUE));
659 fctx_stoptimer(fetchctx_t *fctx) {
663 * We don't return a result if resetting the timer to inactive fails
664 * since there's nothing to be done about it. Resetting to inactive
665 * should never fail anyway, since the code as currently written
666 * cannot fail in that case.
668 result = isc_timer_reset(fctx->timer, isc_timertype_inactive,
669 NULL, NULL, ISC_TRUE);
670 if (result != ISC_R_SUCCESS) {
671 UNEXPECTED_ERROR(__FILE__, __LINE__,
672 "isc_timer_reset(): %s",
673 isc_result_totext(result));
678 static inline isc_result_t
679 fctx_startidletimer(fetchctx_t *fctx, isc_interval_t *interval) {
681 * Start the idle timer for fctx. The lifetime timer continues
684 return (isc_timer_reset(fctx->timer, isc_timertype_once,
685 &fctx->expires, interval, ISC_FALSE));
689 * Stopping the idle timer is equivalent to calling fctx_starttimer(), but
690 * we use fctx_stopidletimer for readability in the code below.
692 #define fctx_stopidletimer fctx_starttimer
696 resquery_destroy(resquery_t **queryp) {
699 REQUIRE(queryp != NULL);
701 REQUIRE(!ISC_LINK_LINKED(query, link));
703 INSIST(query->tcpsocket == NULL);
705 query->fctx->nqueries--;
706 if (SHUTTINGDOWN(query->fctx))
707 maybe_destroy(query->fctx); /* Locks bucket. */
709 isc_mem_put(query->mctx, query, sizeof(*query));
714 fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp,
715 isc_time_t *finish, isc_boolean_t no_response)
719 unsigned int rtt, rttms;
722 dns_adbaddrinfo_t *addrinfo;
723 isc_socket_t *socket;
728 FCTXTRACE("cancelquery");
730 REQUIRE(!RESQUERY_CANCELED(query));
732 query->attributes |= RESQUERY_ATTR_CANCELED;
735 * Should we update the RTT?
737 if (finish != NULL || no_response) {
738 if (finish != NULL) {
740 * We have both the start and finish times for this
741 * packet, so we can compute a real RTT.
743 rtt = (unsigned int)isc_time_microdiff(finish,
745 factor = DNS_ADB_RTTADJDEFAULT;
748 if (rttms < DNS_RESOLVER_QRYRTTCLASS0) {
750 dns_resstatscounter_queryrtt0);
751 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS1) {
753 dns_resstatscounter_queryrtt1);
754 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS2) {
756 dns_resstatscounter_queryrtt2);
757 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS3) {
759 dns_resstatscounter_queryrtt3);
760 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS4) {
762 dns_resstatscounter_queryrtt4);
765 dns_resstatscounter_queryrtt5);
769 * We don't have an RTT for this query. Maybe the
770 * packet was lost, or maybe this server is very
771 * slow. We don't know. Increase the RTT.
774 rtt = query->addrinfo->srtt + 200000;
778 * Replace the current RTT with our value.
780 factor = DNS_ADB_RTTADJREPLACE;
782 dns_adb_adjustsrtt(fctx->adb, query->addrinfo, rtt, factor);
786 * Age RTTs of servers not tried.
788 factor = DNS_ADB_RTTADJAGE;
790 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
792 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
793 if (UNMARKED(addrinfo))
794 dns_adb_adjustsrtt(fctx->adb, addrinfo,
797 if (finish != NULL && TRIEDFIND(fctx))
798 for (find = ISC_LIST_HEAD(fctx->finds);
800 find = ISC_LIST_NEXT(find, publink))
801 for (addrinfo = ISC_LIST_HEAD(find->list);
803 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
804 if (UNMARKED(addrinfo))
805 dns_adb_adjustsrtt(fctx->adb, addrinfo,
808 if (finish != NULL && TRIEDALT(fctx)) {
809 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
811 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
812 if (UNMARKED(addrinfo))
813 dns_adb_adjustsrtt(fctx->adb, addrinfo,
815 for (find = ISC_LIST_HEAD(fctx->altfinds);
817 find = ISC_LIST_NEXT(find, publink))
818 for (addrinfo = ISC_LIST_HEAD(find->list);
820 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
821 if (UNMARKED(addrinfo))
822 dns_adb_adjustsrtt(fctx->adb, addrinfo,
827 * Check for any outstanding socket events. If they exist, cancel
828 * them and let the event handlers finish the cleanup. The resolver
829 * only needs to worry about managing the connect and send events;
830 * the dispatcher manages the recv events.
832 if (RESQUERY_CONNECTING(query)) {
834 * Cancel the connect.
836 if (query->tcpsocket != NULL) {
837 isc_socket_cancel(query->tcpsocket, NULL,
838 ISC_SOCKCANCEL_CONNECT);
839 } else if (query->dispentry != NULL) {
840 INSIST(query->exclusivesocket);
841 socket = dns_dispatch_getentrysocket(query->dispentry);
843 isc_socket_cancel(socket, NULL,
844 ISC_SOCKCANCEL_CONNECT);
846 } else if (RESQUERY_SENDING(query)) {
848 * Cancel the pending send.
850 if (query->exclusivesocket && query->dispentry != NULL)
851 socket = dns_dispatch_getentrysocket(query->dispentry);
853 socket = dns_dispatch_getsocket(query->dispatch);
855 isc_socket_cancel(socket, NULL, ISC_SOCKCANCEL_SEND);
858 if (query->dispentry != NULL)
859 dns_dispatch_removeresponse(&query->dispentry, deventp);
861 ISC_LIST_UNLINK(fctx->queries, query, link);
863 if (query->tsig != NULL)
864 isc_buffer_free(&query->tsig);
866 if (query->tsigkey != NULL)
867 dns_tsigkey_detach(&query->tsigkey);
869 if (query->dispatch != NULL)
870 dns_dispatch_detach(&query->dispatch);
872 if (! (RESQUERY_CONNECTING(query) || RESQUERY_SENDING(query)))
874 * It's safe to destroy the query now.
876 resquery_destroy(&query);
880 fctx_cancelqueries(fetchctx_t *fctx, isc_boolean_t no_response) {
881 resquery_t *query, *next_query;
883 FCTXTRACE("cancelqueries");
885 for (query = ISC_LIST_HEAD(fctx->queries);
887 query = next_query) {
888 next_query = ISC_LIST_NEXT(query, link);
889 fctx_cancelquery(&query, NULL, NULL, no_response);
894 fctx_cleanupfinds(fetchctx_t *fctx) {
895 dns_adbfind_t *find, *next_find;
897 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
899 for (find = ISC_LIST_HEAD(fctx->finds);
902 next_find = ISC_LIST_NEXT(find, publink);
903 ISC_LIST_UNLINK(fctx->finds, find, publink);
904 dns_adb_destroyfind(&find);
910 fctx_cleanupaltfinds(fetchctx_t *fctx) {
911 dns_adbfind_t *find, *next_find;
913 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
915 for (find = ISC_LIST_HEAD(fctx->altfinds);
918 next_find = ISC_LIST_NEXT(find, publink);
919 ISC_LIST_UNLINK(fctx->altfinds, find, publink);
920 dns_adb_destroyfind(&find);
922 fctx->altfind = NULL;
926 fctx_cleanupforwaddrs(fetchctx_t *fctx) {
927 dns_adbaddrinfo_t *addr, *next_addr;
929 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
931 for (addr = ISC_LIST_HEAD(fctx->forwaddrs);
934 next_addr = ISC_LIST_NEXT(addr, publink);
935 ISC_LIST_UNLINK(fctx->forwaddrs, addr, publink);
936 dns_adb_freeaddrinfo(fctx->adb, &addr);
941 fctx_cleanupaltaddrs(fetchctx_t *fctx) {
942 dns_adbaddrinfo_t *addr, *next_addr;
944 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
946 for (addr = ISC_LIST_HEAD(fctx->altaddrs);
949 next_addr = ISC_LIST_NEXT(addr, publink);
950 ISC_LIST_UNLINK(fctx->altaddrs, addr, publink);
951 dns_adb_freeaddrinfo(fctx->adb, &addr);
956 fctx_stopeverything(fetchctx_t *fctx, isc_boolean_t no_response) {
957 FCTXTRACE("stopeverything");
958 fctx_cancelqueries(fctx, no_response);
959 fctx_cleanupfinds(fctx);
960 fctx_cleanupaltfinds(fctx);
961 fctx_cleanupforwaddrs(fctx);
962 fctx_cleanupaltaddrs(fctx);
963 fctx_stoptimer(fctx);
967 fctx_sendevents(fetchctx_t *fctx, isc_result_t result, int line) {
968 dns_fetchevent_t *event, *next_event;
970 unsigned int count = 0;
972 isc_boolean_t logit = ISC_FALSE;
974 unsigned int old_spillat;
975 unsigned int new_spillat = 0; /* initialized to silence
979 * Caller must be holding the appropriate bucket lock.
981 REQUIRE(fctx->state == fetchstate_done);
983 FCTXTRACE("sendevents");
986 * Keep some record of fetch result for logging later (if required).
988 fctx->result = result;
989 fctx->exitline = line;
991 fctx->duration = isc_time_microdiff(&now, &fctx->start);
993 for (event = ISC_LIST_HEAD(fctx->events);
995 event = next_event) {
996 next_event = ISC_LIST_NEXT(event, ev_link);
997 ISC_LIST_UNLINK(fctx->events, event, ev_link);
998 task = event->ev_sender;
999 event->ev_sender = fctx;
1000 if (!HAVE_ANSWER(fctx))
1001 event->result = result;
1003 INSIST(result != ISC_R_SUCCESS ||
1004 dns_rdataset_isassociated(event->rdataset) ||
1005 fctx->type == dns_rdatatype_any ||
1006 fctx->type == dns_rdatatype_rrsig ||
1007 fctx->type == dns_rdatatype_sig);
1010 * Negative results must be indicated in event->result.
1012 if (dns_rdataset_isassociated(event->rdataset) &&
1013 event->rdataset->type == dns_rdatatype_none) {
1014 INSIST(event->result == DNS_R_NCACHENXDOMAIN ||
1015 event->result == DNS_R_NCACHENXRRSET);
1018 isc_task_sendanddetach(&task, ISC_EVENT_PTR(&event));
1022 if ((fctx->attributes & FCTX_ATTR_HAVEANSWER) != 0 &&
1024 (count < fctx->res->spillatmax || fctx->res->spillatmax == 0)) {
1025 LOCK(&fctx->res->lock);
1026 if (count == fctx->res->spillat && !fctx->res->exiting) {
1027 old_spillat = fctx->res->spillat;
1028 fctx->res->spillat += 5;
1029 if (fctx->res->spillat > fctx->res->spillatmax &&
1030 fctx->res->spillatmax != 0)
1031 fctx->res->spillat = fctx->res->spillatmax;
1032 new_spillat = fctx->res->spillat;
1033 if (new_spillat != old_spillat) {
1036 isc_interval_set(&i, 20 * 60, 0);
1037 result = isc_timer_reset(fctx->res->spillattimer,
1038 isc_timertype_ticker, NULL,
1040 RUNTIME_CHECK(result == ISC_R_SUCCESS);
1042 UNLOCK(&fctx->res->lock);
1044 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
1045 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
1046 "clients-per-query increased to %u",
1052 log_edns(fetchctx_t *fctx) {
1053 char domainbuf[DNS_NAME_FORMATSIZE];
1055 if (fctx->reason == NULL)
1058 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
1059 isc_log_write(dns_lctx, DNS_LOGCATEGORY_EDNS_DISABLED,
1060 DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO,
1061 "too many timeouts resolving '%s' (in '%s'?): %s",
1062 fctx->info, domainbuf, fctx->reason);
1064 fctx->reason = NULL;
1068 fctx_done(fetchctx_t *fctx, isc_result_t result, int line) {
1069 dns_resolver_t *res;
1070 isc_boolean_t no_response;
1078 if (result == ISC_R_SUCCESS) {
1080 * Log any deferred EDNS timeout messages.
1083 no_response = ISC_TRUE;
1085 no_response = ISC_FALSE;
1087 fctx->reason = NULL;
1088 fctx_stopeverything(fctx, no_response);
1090 LOCK(&res->buckets[fctx->bucketnum].lock);
1092 fctx->state = fetchstate_done;
1093 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
1094 fctx_sendevents(fctx, result, line);
1096 UNLOCK(&res->buckets[fctx->bucketnum].lock);
1100 process_sendevent(resquery_t *query, isc_event_t *event) {
1101 isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1102 isc_boolean_t retry = ISC_FALSE;
1103 isc_result_t result;
1108 if (RESQUERY_CANCELED(query)) {
1109 if (query->sends == 0 && query->connects == 0) {
1111 * This query was canceled while the
1112 * isc_socket_sendto/connect() was in progress.
1114 if (query->tcpsocket != NULL)
1115 isc_socket_detach(&query->tcpsocket);
1116 resquery_destroy(&query);
1119 switch (sevent->result) {
1123 case ISC_R_HOSTUNREACH:
1124 case ISC_R_NETUNREACH:
1126 case ISC_R_ADDRNOTAVAIL:
1127 case ISC_R_CONNREFUSED:
1130 * No route to remote.
1132 add_bad(fctx, query->addrinfo, sevent->result,
1134 fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
1139 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
1144 isc_event_free(&event);
1148 * Behave as if the idle timer has expired. For TCP
1149 * this may not actually reflect the latest timer.
1151 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
1152 result = fctx_stopidletimer(fctx);
1153 if (result != ISC_R_SUCCESS)
1154 fctx_done(fctx, result, __LINE__);
1156 fctx_try(fctx, ISC_TRUE);
1161 resquery_udpconnected(isc_task_t *task, isc_event_t *event) {
1162 resquery_t *query = event->ev_arg;
1164 REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
1166 QTRACE("udpconnected");
1170 INSIST(RESQUERY_CONNECTING(query));
1174 process_sendevent(query, event);
1178 resquery_senddone(isc_task_t *task, isc_event_t *event) {
1179 resquery_t *query = event->ev_arg;
1181 REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);
1188 * Currently we don't wait for the senddone event before retrying
1189 * a query. This means that if we get really behind, we may end
1190 * up doing extra work!
1195 INSIST(RESQUERY_SENDING(query));
1199 process_sendevent(query, event);
1202 static inline isc_result_t
1203 fctx_addopt(dns_message_t *message, unsigned int version,
1204 isc_uint16_t udpsize, isc_boolean_t request_nsid)
1206 dns_rdataset_t *rdataset;
1207 dns_rdatalist_t *rdatalist;
1209 isc_result_t result;
1212 result = dns_message_gettemprdatalist(message, &rdatalist);
1213 if (result != ISC_R_SUCCESS)
1216 result = dns_message_gettemprdata(message, &rdata);
1217 if (result != ISC_R_SUCCESS)
1220 result = dns_message_gettemprdataset(message, &rdataset);
1221 if (result != ISC_R_SUCCESS)
1223 dns_rdataset_init(rdataset);
1225 rdatalist->type = dns_rdatatype_opt;
1226 rdatalist->covers = 0;
1229 * Set Maximum UDP buffer size.
1231 rdatalist->rdclass = udpsize;
1234 * Set EXTENDED-RCODE and Z to 0, DO to 1.
1236 rdatalist->ttl = (version << 16);
1237 rdatalist->ttl |= DNS_MESSAGEEXTFLAG_DO;
1240 * Set EDNS options if applicable
1243 /* Send empty NSID option (RFC5001) */
1244 unsigned char data[4];
1247 isc_buffer_init(&buf, data, sizeof(data));
1248 isc_buffer_putuint16(&buf, DNS_OPT_NSID);
1249 isc_buffer_putuint16(&buf, 0);
1251 rdata->length = sizeof(data);
1257 rdata->rdclass = rdatalist->rdclass;
1258 rdata->type = rdatalist->type;
1261 ISC_LIST_INIT(rdatalist->rdata);
1262 ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
1263 RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset) == ISC_R_SUCCESS);
1265 return (dns_message_setopt(message, rdataset));
1269 fctx_setretryinterval(fetchctx_t *fctx, unsigned int rtt) {
1270 unsigned int seconds;
1274 * We retry every .8 seconds the first two times through the address
1275 * list, and then we do exponential back-off.
1277 if (fctx->restarts < 3)
1280 us = (800000 << (fctx->restarts - 2));
1283 * Double the round-trip time.
1288 * Always wait for at least the doubled round-trip time.
1294 * But don't ever wait for more than 10 seconds.
1299 seconds = us / 1000000;
1300 us -= seconds * 1000000;
1301 isc_interval_set(&fctx->interval, seconds, us * 1000);
1305 fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
1306 unsigned int options)
1308 dns_resolver_t *res;
1310 isc_result_t result;
1312 isc_sockaddr_t addr;
1313 isc_boolean_t have_addr = ISC_FALSE;
1318 task = res->buckets[fctx->bucketnum].task;
1320 fctx_setretryinterval(fctx, addrinfo->srtt);
1321 result = fctx_startidletimer(fctx, &fctx->interval);
1322 if (result != ISC_R_SUCCESS)
1325 INSIST(ISC_LIST_EMPTY(fctx->validators));
1327 dns_message_reset(fctx->rmessage, DNS_MESSAGE_INTENTPARSE);
1329 query = isc_mem_get(res->buckets[fctx->bucketnum].mctx,
1331 if (query == NULL) {
1332 result = ISC_R_NOMEMORY;
1333 goto stop_idle_timer;
1335 query->mctx = res->buckets[fctx->bucketnum].mctx;
1336 query->options = options;
1337 query->attributes = 0;
1339 query->connects = 0;
1341 * Note that the caller MUST guarantee that 'addrinfo' will remain
1342 * valid until this query is canceled.
1344 query->addrinfo = addrinfo;
1345 TIME_NOW(&query->start);
1348 * If this is a TCP query, then we need to make a socket and
1349 * a dispatch for it here. Otherwise we use the resolver's
1352 query->dispatchmgr = res->dispatchmgr;
1353 query->dispatch = NULL;
1354 query->exclusivesocket = ISC_FALSE;
1355 query->tcpsocket = NULL;
1356 if (res->view->peers != NULL) {
1357 dns_peer_t *peer = NULL;
1358 isc_netaddr_t dstip;
1359 isc_netaddr_fromsockaddr(&dstip, &addrinfo->sockaddr);
1360 result = dns_peerlist_peerbyaddr(res->view->peers,
1362 if (result == ISC_R_SUCCESS) {
1363 result = dns_peer_getquerysource(peer, &addr);
1364 if (result == ISC_R_SUCCESS)
1365 have_addr = ISC_TRUE;
1369 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1372 pf = isc_sockaddr_pf(&addrinfo->sockaddr);
1377 dns_dispatch_getlocaladdress(res->dispatchv4,
1382 dns_dispatch_getlocaladdress(res->dispatchv6,
1386 result = ISC_R_NOTIMPLEMENTED;
1389 if (result != ISC_R_SUCCESS)
1392 isc_sockaddr_setport(&addr, 0);
1394 result = isc_socket_create(res->socketmgr, pf,
1397 if (result != ISC_R_SUCCESS)
1400 #ifndef BROKEN_TCP_BIND_BEFORE_CONNECT
1401 result = isc_socket_bind(query->tcpsocket, &addr, 0);
1402 if (result != ISC_R_SUCCESS)
1403 goto cleanup_socket;
1407 * A dispatch will be created once the connect succeeds.
1411 unsigned int attrs, attrmask;
1412 attrs = DNS_DISPATCHATTR_UDP;
1413 switch (isc_sockaddr_pf(&addr)) {
1415 attrs |= DNS_DISPATCHATTR_IPV4;
1418 attrs |= DNS_DISPATCHATTR_IPV6;
1421 result = ISC_R_NOTIMPLEMENTED;
1424 attrmask = DNS_DISPATCHATTR_UDP;
1425 attrmask |= DNS_DISPATCHATTR_TCP;
1426 attrmask |= DNS_DISPATCHATTR_IPV4;
1427 attrmask |= DNS_DISPATCHATTR_IPV6;
1428 result = dns_dispatch_getudp(res->dispatchmgr,
1430 res->taskmgr, &addr,
1431 4096, 1000, 32768, 16411,
1432 16433, attrs, attrmask,
1434 if (result != ISC_R_SUCCESS)
1437 switch (isc_sockaddr_pf(&addrinfo->sockaddr)) {
1439 dns_dispatch_attach(res->dispatchv4,
1441 query->exclusivesocket = res->exclusivev4;
1444 dns_dispatch_attach(res->dispatchv6,
1446 query->exclusivesocket = res->exclusivev6;
1449 result = ISC_R_NOTIMPLEMENTED;
1454 * We should always have a valid dispatcher here. If we
1455 * don't support a protocol family, then its dispatcher
1456 * will be NULL, but we shouldn't be finding addresses for
1457 * protocol types we don't support, so the dispatcher
1458 * we found should never be NULL.
1460 INSIST(query->dispatch != NULL);
1463 query->dispentry = NULL;
1466 query->tsigkey = NULL;
1467 ISC_LINK_INIT(query, link);
1468 query->magic = QUERY_MAGIC;
1470 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1472 * Connect to the remote server.
1474 * XXXRTH Should we attach to the socket?
1476 result = isc_socket_connect(query->tcpsocket,
1477 &addrinfo->sockaddr, task,
1478 resquery_connected, query);
1479 if (result != ISC_R_SUCCESS)
1480 goto cleanup_socket;
1482 QTRACE("connecting via TCP");
1484 result = resquery_send(query);
1485 if (result != ISC_R_SUCCESS)
1486 goto cleanup_dispatch;
1490 ISC_LIST_APPEND(fctx->queries, query, link);
1491 query->fctx->nqueries++;
1492 if (isc_sockaddr_pf(&addrinfo->sockaddr) == PF_INET)
1493 inc_stats(res, dns_resstatscounter_queryv4);
1495 inc_stats(res, dns_resstatscounter_queryv6);
1496 if (res->view->resquerystats != NULL)
1497 dns_rdatatypestats_increment(res->view->resquerystats,
1500 return (ISC_R_SUCCESS);
1503 isc_socket_detach(&query->tcpsocket);
1506 if (query->dispatch != NULL)
1507 dns_dispatch_detach(&query->dispatch);
1511 isc_mem_put(res->buckets[fctx->bucketnum].mctx,
1512 query, sizeof(*query));
1515 RUNTIME_CHECK(fctx_stopidletimer(fctx) == ISC_R_SUCCESS);
1520 static isc_boolean_t
1521 triededns(fetchctx_t *fctx, isc_sockaddr_t *address) {
1524 for (sa = ISC_LIST_HEAD(fctx->edns);
1526 sa = ISC_LIST_NEXT(sa, link)) {
1527 if (isc_sockaddr_equal(sa, address))
1535 add_triededns(fetchctx_t *fctx, isc_sockaddr_t *address) {
1538 if (triededns(fctx, address))
1541 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
1547 ISC_LIST_INITANDAPPEND(fctx->edns, sa, link);
1550 static isc_boolean_t
1551 triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) {
1554 for (sa = ISC_LIST_HEAD(fctx->edns512);
1556 sa = ISC_LIST_NEXT(sa, link)) {
1557 if (isc_sockaddr_equal(sa, address))
1565 add_triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) {
1568 if (triededns512(fctx, address))
1571 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
1577 ISC_LIST_INITANDAPPEND(fctx->edns512, sa, link);
1581 resquery_send(resquery_t *query) {
1583 isc_result_t result;
1584 dns_name_t *qname = NULL;
1585 dns_rdataset_t *qrdataset = NULL;
1587 dns_resolver_t *res;
1589 isc_socket_t *socket;
1590 isc_buffer_t tcpbuffer;
1591 isc_sockaddr_t *address;
1592 isc_buffer_t *buffer;
1593 isc_netaddr_t ipaddr;
1594 dns_tsigkey_t *tsigkey = NULL;
1595 dns_peer_t *peer = NULL;
1596 isc_boolean_t useedns;
1597 dns_compress_t cctx;
1598 isc_boolean_t cleanup_cctx = ISC_FALSE;
1599 isc_boolean_t secure_domain;
1605 task = res->buckets[fctx->bucketnum].task;
1608 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1610 * Reserve space for the TCP message length.
1612 isc_buffer_init(&tcpbuffer, query->data, sizeof(query->data));
1613 isc_buffer_init(&query->buffer, query->data + 2,
1614 sizeof(query->data) - 2);
1615 buffer = &tcpbuffer;
1617 isc_buffer_init(&query->buffer, query->data,
1618 sizeof(query->data));
1619 buffer = &query->buffer;
1622 result = dns_message_gettempname(fctx->qmessage, &qname);
1623 if (result != ISC_R_SUCCESS)
1625 result = dns_message_gettemprdataset(fctx->qmessage, &qrdataset);
1626 if (result != ISC_R_SUCCESS)
1630 * Get a query id from the dispatch.
1632 result = dns_dispatch_addresponse2(query->dispatch,
1633 &query->addrinfo->sockaddr,
1640 if (result != ISC_R_SUCCESS)
1643 fctx->qmessage->opcode = dns_opcode_query;
1648 dns_name_init(qname, NULL);
1649 dns_name_clone(&fctx->name, qname);
1650 dns_rdataset_init(qrdataset);
1651 dns_rdataset_makequestion(qrdataset, res->rdclass, fctx->type);
1652 ISC_LIST_APPEND(qname->list, qrdataset, link);
1653 dns_message_addname(fctx->qmessage, qname, DNS_SECTION_QUESTION);
1658 * Set RD if the client has requested that we do a recursive query,
1659 * or if we're sending to a forwarder.
1661 if ((query->options & DNS_FETCHOPT_RECURSIVE) != 0 ||
1662 ISFORWARDER(query->addrinfo))
1663 fctx->qmessage->flags |= DNS_MESSAGEFLAG_RD;
1666 * Set CD if the client says don't validate or the question is
1667 * under a secure entry point.
1669 if ((query->options & DNS_FETCHOPT_NOVALIDATE) != 0) {
1670 fctx->qmessage->flags |= DNS_MESSAGEFLAG_CD;
1671 } else if (res->view->enablevalidation) {
1672 result = dns_keytable_issecuredomain(res->view->secroots,
1675 if (result != ISC_R_SUCCESS)
1676 secure_domain = ISC_FALSE;
1677 if (res->view->dlv != NULL)
1678 secure_domain = ISC_TRUE;
1680 fctx->qmessage->flags |= DNS_MESSAGEFLAG_CD;
1684 * We don't have to set opcode because it defaults to query.
1686 fctx->qmessage->id = query->id;
1689 * Convert the question to wire format.
1691 result = dns_compress_init(&cctx, -1, fctx->res->mctx);
1692 if (result != ISC_R_SUCCESS)
1693 goto cleanup_message;
1694 cleanup_cctx = ISC_TRUE;
1696 result = dns_message_renderbegin(fctx->qmessage, &cctx,
1698 if (result != ISC_R_SUCCESS)
1699 goto cleanup_message;
1701 result = dns_message_rendersection(fctx->qmessage,
1702 DNS_SECTION_QUESTION, 0);
1703 if (result != ISC_R_SUCCESS)
1704 goto cleanup_message;
1707 isc_netaddr_fromsockaddr(&ipaddr, &query->addrinfo->sockaddr);
1708 (void) dns_peerlist_peerbyaddr(fctx->res->view->peers, &ipaddr, &peer);
1711 * The ADB does not know about servers with "edns no". Check this,
1712 * and then inform the ADB for future use.
1714 if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0 &&
1716 dns_peer_getsupportedns(peer, &useedns) == ISC_R_SUCCESS &&
1719 query->options |= DNS_FETCHOPT_NOEDNS0;
1720 dns_adb_changeflags(fctx->adb, query->addrinfo,
1721 DNS_FETCHOPT_NOEDNS0,
1722 DNS_FETCHOPT_NOEDNS0);
1725 /* Sync NOEDNS0 flag in addrinfo->flags and options now. */
1726 if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) != 0)
1727 query->options |= DNS_FETCHOPT_NOEDNS0;
1730 * Handle timeouts by reducing the UDP response size to 512 bytes
1731 * then if that doesn't work disabling EDNS (includes DO) and CD.
1733 * These timeout can be due to:
1734 * * broken nameservers that don't respond to EDNS queries.
1735 * * broken/misconfigured firewalls and NAT implementations
1736 * that don't handle IP fragmentation.
1737 * * broken/misconfigured firewalls that don't handle responses
1738 * greater than 512 bytes.
1739 * * broken/misconfigured firewalls that don't handle EDNS, DO
1741 * * packet loss / link outage.
1743 if (fctx->timeout) {
1744 if ((triededns512(fctx, &query->addrinfo->sockaddr) ||
1745 fctx->timeouts >= (MAX_EDNS0_TIMEOUTS * 2)) &&
1746 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
1747 query->options |= DNS_FETCHOPT_NOEDNS0;
1748 fctx->reason = "disabling EDNS";
1749 } else if ((triededns(fctx, &query->addrinfo->sockaddr) ||
1750 fctx->timeouts >= MAX_EDNS0_TIMEOUTS) &&
1751 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
1752 query->options |= DNS_FETCHOPT_EDNS512;
1753 fctx->reason = "reducing the advertised EDNS UDP "
1754 "packet size to 512 octets";
1756 fctx->timeout = ISC_FALSE;
1760 * Use EDNS0, unless the caller doesn't want it, or we know that
1761 * the remote server doesn't like it.
1763 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
1764 if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0) {
1765 unsigned int version = 0; /* Default version. */
1767 isc_uint16_t udpsize = res->udpsize;
1768 isc_boolean_t reqnsid = res->view->requestnsid;
1770 flags = query->addrinfo->flags;
1771 if ((flags & DNS_FETCHOPT_EDNSVERSIONSET) != 0) {
1772 version = flags & DNS_FETCHOPT_EDNSVERSIONMASK;
1773 version >>= DNS_FETCHOPT_EDNSVERSIONSHIFT;
1775 if ((query->options & DNS_FETCHOPT_EDNS512) != 0)
1777 else if (peer != NULL)
1778 (void)dns_peer_getudpsize(peer, &udpsize);
1780 /* request NSID for current view or peer? */
1782 (void) dns_peer_getrequestnsid(peer, &reqnsid);
1783 result = fctx_addopt(fctx->qmessage, version,
1785 if (reqnsid && result == ISC_R_SUCCESS) {
1786 query->options |= DNS_FETCHOPT_WANTNSID;
1787 } else if (result != ISC_R_SUCCESS) {
1789 * We couldn't add the OPT, but we'll press on.
1790 * We're not using EDNS0, so set the NOEDNS0
1793 query->options |= DNS_FETCHOPT_NOEDNS0;
1797 * We know this server doesn't like EDNS0, so we
1798 * won't use it. Set the NOEDNS0 bit since we're
1801 query->options |= DNS_FETCHOPT_NOEDNS0;
1806 * If we need EDNS0 to do this query and aren't using it, we lose.
1808 if (NEEDEDNS0(fctx) && (query->options & DNS_FETCHOPT_NOEDNS0) != 0) {
1809 result = DNS_R_SERVFAIL;
1810 goto cleanup_message;
1813 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0)
1814 add_triededns(fctx, &query->addrinfo->sockaddr);
1816 if ((query->options & DNS_FETCHOPT_EDNS512) != 0)
1817 add_triededns512(fctx, &query->addrinfo->sockaddr);
1820 * Clear CD if EDNS is not in use.
1822 if ((query->options & DNS_FETCHOPT_NOEDNS0) != 0)
1823 fctx->qmessage->flags &= ~DNS_MESSAGEFLAG_CD;
1826 * Add TSIG record tailored to the current recipient.
1828 result = dns_view_getpeertsig(fctx->res->view, &ipaddr, &tsigkey);
1829 if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND)
1830 goto cleanup_message;
1832 if (tsigkey != NULL) {
1833 result = dns_message_settsigkey(fctx->qmessage, tsigkey);
1834 dns_tsigkey_detach(&tsigkey);
1835 if (result != ISC_R_SUCCESS)
1836 goto cleanup_message;
1839 result = dns_message_rendersection(fctx->qmessage,
1840 DNS_SECTION_ADDITIONAL, 0);
1841 if (result != ISC_R_SUCCESS)
1842 goto cleanup_message;
1844 result = dns_message_renderend(fctx->qmessage);
1845 if (result != ISC_R_SUCCESS)
1846 goto cleanup_message;
1848 dns_compress_invalidate(&cctx);
1849 cleanup_cctx = ISC_FALSE;
1851 if (dns_message_gettsigkey(fctx->qmessage) != NULL) {
1852 dns_tsigkey_attach(dns_message_gettsigkey(fctx->qmessage),
1854 result = dns_message_getquerytsig(fctx->qmessage,
1857 if (result != ISC_R_SUCCESS)
1858 goto cleanup_message;
1862 * If using TCP, write the length of the message at the beginning
1865 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1866 isc_buffer_usedregion(&query->buffer, &r);
1867 isc_buffer_putuint16(&tcpbuffer, (isc_uint16_t)r.length);
1868 isc_buffer_add(&tcpbuffer, r.length);
1872 * We're now done with the query message.
1874 dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER);
1876 if (query->exclusivesocket)
1877 socket = dns_dispatch_getentrysocket(query->dispentry);
1879 socket = dns_dispatch_getsocket(query->dispatch);
1883 if ((query->options & DNS_FETCHOPT_TCP) == 0) {
1884 address = &query->addrinfo->sockaddr;
1885 if (query->exclusivesocket) {
1886 result = isc_socket_connect(socket, address, task,
1887 resquery_udpconnected,
1889 if (result != ISC_R_SUCCESS)
1890 goto cleanup_message;
1894 isc_buffer_usedregion(buffer, &r);
1897 * XXXRTH Make sure we don't send to ourselves! We should probably
1898 * prune out these addresses when we get them from the ADB.
1900 result = isc_socket_sendto(socket, &r, task, resquery_senddone,
1901 query, address, NULL);
1902 if (result != ISC_R_SUCCESS)
1903 goto cleanup_message;
1909 return (ISC_R_SUCCESS);
1913 dns_compress_invalidate(&cctx);
1915 dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER);
1918 * Stop the dispatcher from listening.
1920 dns_dispatch_removeresponse(&query->dispentry, NULL);
1924 dns_message_puttempname(fctx->qmessage, &qname);
1925 if (qrdataset != NULL)
1926 dns_message_puttemprdataset(fctx->qmessage, &qrdataset);
1932 resquery_connected(isc_task_t *task, isc_event_t *event) {
1933 isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1934 resquery_t *query = event->ev_arg;
1935 isc_boolean_t retry = ISC_FALSE;
1936 isc_interval_t interval;
1937 isc_result_t result;
1941 REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
1942 REQUIRE(VALID_QUERY(query));
1944 QTRACE("connected");
1951 * Currently we don't wait for the connect event before retrying
1952 * a query. This means that if we get really behind, we may end
1953 * up doing extra work!
1959 if (RESQUERY_CANCELED(query)) {
1961 * This query was canceled while the connect() was in
1964 isc_socket_detach(&query->tcpsocket);
1965 resquery_destroy(&query);
1967 switch (sevent->result) {
1971 * Extend the idle timer for TCP. 20 seconds
1972 * should be long enough for a TCP connection to be
1973 * established, a single DNS request to be sent,
1974 * and the response received.
1976 isc_interval_set(&interval, 20, 0);
1977 result = fctx_startidletimer(query->fctx, &interval);
1978 if (result != ISC_R_SUCCESS) {
1979 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
1980 fctx_done(fctx, result, __LINE__);
1984 * We are connected. Create a dispatcher and
1988 attrs |= DNS_DISPATCHATTR_TCP;
1989 attrs |= DNS_DISPATCHATTR_PRIVATE;
1990 attrs |= DNS_DISPATCHATTR_CONNECTED;
1991 if (isc_sockaddr_pf(&query->addrinfo->sockaddr) ==
1993 attrs |= DNS_DISPATCHATTR_IPV4;
1995 attrs |= DNS_DISPATCHATTR_IPV6;
1996 attrs |= DNS_DISPATCHATTR_MAKEQUERY;
1998 result = dns_dispatch_createtcp(query->dispatchmgr,
2000 query->fctx->res->taskmgr,
2001 4096, 2, 1, 1, 3, attrs,
2005 * Regardless of whether dns_dispatch_create()
2006 * succeeded or not, we don't need our reference
2007 * to the socket anymore.
2009 isc_socket_detach(&query->tcpsocket);
2011 if (result == ISC_R_SUCCESS)
2012 result = resquery_send(query);
2014 if (result != ISC_R_SUCCESS) {
2015 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
2016 fctx_done(fctx, result, __LINE__);
2020 case ISC_R_NETUNREACH:
2021 case ISC_R_HOSTUNREACH:
2022 case ISC_R_CONNREFUSED:
2024 case ISC_R_ADDRNOTAVAIL:
2025 case ISC_R_CONNECTIONRESET:
2027 * No route to remote.
2029 isc_socket_detach(&query->tcpsocket);
2030 fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
2035 isc_socket_detach(&query->tcpsocket);
2036 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
2041 isc_event_free(&event);
2045 * Behave as if the idle timer has expired. For TCP
2046 * connections this may not actually reflect the latest timer.
2048 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
2049 result = fctx_stopidletimer(fctx);
2050 if (result != ISC_R_SUCCESS)
2051 fctx_done(fctx, result, __LINE__);
2053 fctx_try(fctx, ISC_TRUE);
2058 fctx_finddone(isc_task_t *task, isc_event_t *event) {
2060 dns_adbfind_t *find;
2061 dns_resolver_t *res;
2062 isc_boolean_t want_try = ISC_FALSE;
2063 isc_boolean_t want_done = ISC_FALSE;
2064 isc_boolean_t bucket_empty = ISC_FALSE;
2065 unsigned int bucketnum;
2067 find = event->ev_sender;
2068 fctx = event->ev_arg;
2069 REQUIRE(VALID_FCTX(fctx));
2074 FCTXTRACE("finddone");
2076 INSIST(fctx->pending > 0);
2079 if (ADDRWAIT(fctx)) {
2081 * The fetch is waiting for a name to be found.
2083 INSIST(!SHUTTINGDOWN(fctx));
2084 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
2085 if (event->ev_type == DNS_EVENT_ADBMOREADDRESSES)
2086 want_try = ISC_TRUE;
2089 if (fctx->pending == 0) {
2091 * We've got nothing else to wait for and don't
2092 * know the answer. There's nothing to do but
2095 want_done = ISC_TRUE;
2098 } else if (SHUTTINGDOWN(fctx) && fctx->pending == 0 &&
2099 fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators)) {
2100 bucketnum = fctx->bucketnum;
2101 LOCK(&res->buckets[bucketnum].lock);
2103 * Note that we had to wait until we had the lock before
2104 * looking at fctx->references.
2106 if (fctx->references == 0)
2107 bucket_empty = fctx_destroy(fctx);
2108 UNLOCK(&res->buckets[bucketnum].lock);
2111 isc_event_free(&event);
2112 dns_adb_destroyfind(&find);
2115 fctx_try(fctx, ISC_TRUE);
2117 fctx_done(fctx, ISC_R_FAILURE, __LINE__);
2118 else if (bucket_empty)
2123 static inline isc_boolean_t
2124 bad_server(fetchctx_t *fctx, isc_sockaddr_t *address) {
2127 for (sa = ISC_LIST_HEAD(fctx->bad);
2129 sa = ISC_LIST_NEXT(sa, link)) {
2130 if (isc_sockaddr_equal(sa, address))
2137 static inline isc_boolean_t
2138 mark_bad(fetchctx_t *fctx) {
2139 dns_adbfind_t *curr;
2140 dns_adbaddrinfo_t *addrinfo;
2141 isc_boolean_t all_bad = ISC_TRUE;
2144 * Mark all known bad servers, so we don't try to talk to them
2149 * Mark any bad nameservers.
2151 for (curr = ISC_LIST_HEAD(fctx->finds);
2153 curr = ISC_LIST_NEXT(curr, publink)) {
2154 for (addrinfo = ISC_LIST_HEAD(curr->list);
2156 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2157 if (bad_server(fctx, &addrinfo->sockaddr))
2158 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2160 all_bad = ISC_FALSE;
2165 * Mark any bad forwarders.
2167 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
2169 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2170 if (bad_server(fctx, &addrinfo->sockaddr))
2171 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2173 all_bad = ISC_FALSE;
2177 * Mark any bad alternates.
2179 for (curr = ISC_LIST_HEAD(fctx->altfinds);
2181 curr = ISC_LIST_NEXT(curr, publink)) {
2182 for (addrinfo = ISC_LIST_HEAD(curr->list);
2184 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2185 if (bad_server(fctx, &addrinfo->sockaddr))
2186 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2188 all_bad = ISC_FALSE;
2192 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
2194 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2195 if (bad_server(fctx, &addrinfo->sockaddr))
2196 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2198 all_bad = ISC_FALSE;
2205 add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_result_t reason,
2206 badnstype_t badtype)
2208 char namebuf[DNS_NAME_FORMATSIZE];
2209 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
2215 const char *sep1, *sep2;
2216 isc_sockaddr_t *address = &addrinfo->sockaddr;
2218 if (reason == DNS_R_LAME)
2222 case badns_unreachable:
2225 case badns_response:
2228 case badns_validation:
2229 break; /* counted as 'valfail' */
2233 if (bad_server(fctx, address)) {
2235 * We already know this server is bad.
2240 FCTXTRACE("add_bad");
2242 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
2247 ISC_LIST_INITANDAPPEND(fctx->bad, sa, link);
2249 if (reason == DNS_R_LAME) /* already logged */
2252 if (reason == DNS_R_UNEXPECTEDRCODE &&
2253 fctx->rmessage->rcode == dns_rcode_servfail &&
2254 ISFORWARDER(addrinfo))
2257 if (reason == DNS_R_UNEXPECTEDRCODE) {
2258 isc_buffer_init(&b, code, sizeof(code) - 1);
2259 dns_rcode_totext(fctx->rmessage->rcode, &b);
2260 code[isc_buffer_usedlength(&b)] = '\0';
2263 } else if (reason == DNS_R_UNEXPECTEDOPCODE) {
2264 isc_buffer_init(&b, code, sizeof(code) - 1);
2265 dns_opcode_totext((dns_opcode_t)fctx->rmessage->opcode, &b);
2266 code[isc_buffer_usedlength(&b)] = '\0';
2274 dns_name_format(&fctx->name, namebuf, sizeof(namebuf));
2275 dns_rdatatype_format(fctx->type, typebuf, sizeof(typebuf));
2276 dns_rdataclass_format(fctx->res->rdclass, classbuf, sizeof(classbuf));
2277 isc_sockaddr_format(address, addrbuf, sizeof(addrbuf));
2278 isc_log_write(dns_lctx, DNS_LOGCATEGORY_LAME_SERVERS,
2279 DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO,
2280 "%s %s%s%sresolving '%s/%s/%s': %s",
2281 dns_result_totext(reason), sep1, code, sep2,
2282 namebuf, typebuf, classbuf, addrbuf);
2286 sort_adbfind(dns_adbfind_t *find) {
2287 dns_adbaddrinfo_t *best, *curr;
2288 dns_adbaddrinfolist_t sorted;
2291 * Lame N^2 bubble sort.
2294 ISC_LIST_INIT(sorted);
2295 while (!ISC_LIST_EMPTY(find->list)) {
2296 best = ISC_LIST_HEAD(find->list);
2297 curr = ISC_LIST_NEXT(best, publink);
2298 while (curr != NULL) {
2299 if (curr->srtt < best->srtt)
2301 curr = ISC_LIST_NEXT(curr, publink);
2303 ISC_LIST_UNLINK(find->list, best, publink);
2304 ISC_LIST_APPEND(sorted, best, publink);
2306 find->list = sorted;
2310 sort_finds(fetchctx_t *fctx) {
2311 dns_adbfind_t *best, *curr;
2312 dns_adbfindlist_t sorted;
2313 dns_adbaddrinfo_t *addrinfo, *bestaddrinfo;
2316 * Lame N^2 bubble sort.
2319 ISC_LIST_INIT(sorted);
2320 while (!ISC_LIST_EMPTY(fctx->finds)) {
2321 best = ISC_LIST_HEAD(fctx->finds);
2322 bestaddrinfo = ISC_LIST_HEAD(best->list);
2323 INSIST(bestaddrinfo != NULL);
2324 curr = ISC_LIST_NEXT(best, publink);
2325 while (curr != NULL) {
2326 addrinfo = ISC_LIST_HEAD(curr->list);
2327 INSIST(addrinfo != NULL);
2328 if (addrinfo->srtt < bestaddrinfo->srtt) {
2330 bestaddrinfo = addrinfo;
2332 curr = ISC_LIST_NEXT(curr, publink);
2334 ISC_LIST_UNLINK(fctx->finds, best, publink);
2335 ISC_LIST_APPEND(sorted, best, publink);
2337 fctx->finds = sorted;
2339 ISC_LIST_INIT(sorted);
2340 while (!ISC_LIST_EMPTY(fctx->altfinds)) {
2341 best = ISC_LIST_HEAD(fctx->altfinds);
2342 bestaddrinfo = ISC_LIST_HEAD(best->list);
2343 INSIST(bestaddrinfo != NULL);
2344 curr = ISC_LIST_NEXT(best, publink);
2345 while (curr != NULL) {
2346 addrinfo = ISC_LIST_HEAD(curr->list);
2347 INSIST(addrinfo != NULL);
2348 if (addrinfo->srtt < bestaddrinfo->srtt) {
2350 bestaddrinfo = addrinfo;
2352 curr = ISC_LIST_NEXT(curr, publink);
2354 ISC_LIST_UNLINK(fctx->altfinds, best, publink);
2355 ISC_LIST_APPEND(sorted, best, publink);
2357 fctx->altfinds = sorted;
2361 findname(fetchctx_t *fctx, dns_name_t *name, in_port_t port,
2362 unsigned int options, unsigned int flags, isc_stdtime_t now,
2363 isc_boolean_t *need_alternate)
2365 dns_adbaddrinfo_t *ai;
2366 dns_adbfind_t *find;
2367 dns_resolver_t *res;
2368 isc_boolean_t unshared;
2369 isc_result_t result;
2372 unshared = ISC_TF((fctx->options | DNS_FETCHOPT_UNSHARED) != 0);
2374 * If this name is a subdomain of the query domain, tell
2375 * the ADB to start looking using zone/hint data. This keeps us
2376 * from getting stuck if the nameserver is beneath the zone cut
2377 * and we don't know its address (e.g. because the A record has
2380 if (dns_name_issubdomain(name, &fctx->domain))
2381 options |= DNS_ADBFIND_STARTATZONE;
2382 options |= DNS_ADBFIND_GLUEOK;
2383 options |= DNS_ADBFIND_HINTOK;
2386 * See what we know about this address.
2389 result = dns_adb_createfind(fctx->adb,
2390 res->buckets[fctx->bucketnum].task,
2391 fctx_finddone, fctx, name,
2392 &fctx->name, fctx->type,
2394 res->view->dstport, &find);
2395 if (result != ISC_R_SUCCESS) {
2396 if (result == DNS_R_ALIAS) {
2398 * XXXRTH Follow the CNAME/DNAME chain?
2400 dns_adb_destroyfind(&find);
2403 } else if (!ISC_LIST_EMPTY(find->list)) {
2405 * We have at least some of the addresses for the
2408 INSIST((find->options & DNS_ADBFIND_WANTEVENT) == 0);
2410 if (flags != 0 || port != 0) {
2411 for (ai = ISC_LIST_HEAD(find->list);
2413 ai = ISC_LIST_NEXT(ai, publink)) {
2416 isc_sockaddr_setport(&ai->sockaddr,
2420 if ((flags & FCTX_ADDRINFO_FORWARDER) != 0)
2421 ISC_LIST_APPEND(fctx->altfinds, find, publink);
2423 ISC_LIST_APPEND(fctx->finds, find, publink);
2426 * We don't know any of the addresses for this
2429 if ((find->options & DNS_ADBFIND_WANTEVENT) != 0) {
2431 * We're looking for them and will get an
2432 * event about it later.
2438 if (need_alternate != NULL &&
2439 !*need_alternate && unshared &&
2440 ((res->dispatchv4 == NULL &&
2441 find->result_v6 != DNS_R_NXDOMAIN) ||
2442 (res->dispatchv6 == NULL &&
2443 find->result_v4 != DNS_R_NXDOMAIN)))
2444 *need_alternate = ISC_TRUE;
2446 if ((find->options & DNS_ADBFIND_LAMEPRUNED) != 0)
2447 fctx->lamecount++; /* cached lame server */
2449 fctx->adberr++; /* unreachable server, etc. */
2452 * If we know there are no addresses for
2453 * the family we are using then try to add
2454 * an alternative server.
2456 if (need_alternate != NULL && !*need_alternate &&
2457 ((res->dispatchv4 == NULL &&
2458 find->result_v6 == DNS_R_NXRRSET) ||
2459 (res->dispatchv6 == NULL &&
2460 find->result_v4 == DNS_R_NXRRSET)))
2461 *need_alternate = ISC_TRUE;
2462 dns_adb_destroyfind(&find);
2467 static isc_boolean_t
2468 isstrictsubdomain(dns_name_t *name1, dns_name_t *name2) {
2470 unsigned int nlabels;
2471 dns_namereln_t namereln;
2473 namereln = dns_name_fullcompare(name1, name2, &order, &nlabels);
2474 return (ISC_TF(namereln == dns_namereln_subdomain));
2478 fctx_getaddresses(fetchctx_t *fctx) {
2479 dns_rdata_t rdata = DNS_RDATA_INIT;
2480 isc_result_t result;
2481 dns_resolver_t *res;
2483 unsigned int stdoptions;
2485 dns_adbaddrinfo_t *ai;
2486 isc_boolean_t all_bad;
2488 isc_boolean_t need_alternate = ISC_FALSE;
2490 FCTXTRACE("getaddresses");
2493 * Don't pound on remote servers. (Failsafe!)
2496 if (fctx->restarts > 10) {
2497 FCTXTRACE("too many restarts");
2498 return (DNS_R_SERVFAIL);
2502 stdoptions = 0; /* Keep compiler happy. */
2508 INSIST(ISC_LIST_EMPTY(fctx->forwaddrs));
2509 INSIST(ISC_LIST_EMPTY(fctx->altaddrs));
2512 * If this fctx has forwarders, use them; otherwise use any
2513 * selective forwarders specified in the view; otherwise use the
2514 * resolver's forwarders (if any).
2516 sa = ISC_LIST_HEAD(fctx->forwarders);
2518 dns_forwarders_t *forwarders = NULL;
2519 dns_name_t *name = &fctx->name;
2521 unsigned int labels;
2522 dns_fixedname_t fixed;
2526 * DS records are found in the parent server.
2527 * Strip label to get the correct forwarder (if any).
2529 if (dns_rdatatype_atparent(fctx->type) &&
2530 dns_name_countlabels(name) > 1) {
2531 dns_name_init(&suffix, NULL);
2532 labels = dns_name_countlabels(name);
2533 dns_name_getlabelsequence(name, 1, labels - 1, &suffix);
2537 dns_fixedname_init(&fixed);
2538 domain = dns_fixedname_name(&fixed);
2539 result = dns_fwdtable_find2(fctx->res->view->fwdtable, name,
2540 domain, &forwarders);
2541 if (result == ISC_R_SUCCESS) {
2542 sa = ISC_LIST_HEAD(forwarders->addrs);
2543 fctx->fwdpolicy = forwarders->fwdpolicy;
2544 if (fctx->fwdpolicy == dns_fwdpolicy_only &&
2545 isstrictsubdomain(domain, &fctx->domain)) {
2548 mctx = res->buckets[fctx->bucketnum].mctx;
2549 dns_name_free(&fctx->domain, mctx);
2550 dns_name_init(&fctx->domain, NULL);
2551 result = dns_name_dup(domain, mctx,
2553 if (result != ISC_R_SUCCESS)
2559 while (sa != NULL) {
2560 if ((isc_sockaddr_pf(sa) == AF_INET &&
2561 fctx->res->dispatchv4 == NULL) ||
2562 (isc_sockaddr_pf(sa) == AF_INET6 &&
2563 fctx->res->dispatchv6 == NULL)) {
2564 sa = ISC_LIST_NEXT(sa, link);
2568 result = dns_adb_findaddrinfo(fctx->adb,
2569 sa, &ai, 0); /* XXXMLG */
2570 if (result == ISC_R_SUCCESS) {
2571 dns_adbaddrinfo_t *cur;
2572 ai->flags |= FCTX_ADDRINFO_FORWARDER;
2573 cur = ISC_LIST_HEAD(fctx->forwaddrs);
2574 while (cur != NULL && cur->srtt < ai->srtt)
2575 cur = ISC_LIST_NEXT(cur, publink);
2577 ISC_LIST_INSERTBEFORE(fctx->forwaddrs, cur,
2580 ISC_LIST_APPEND(fctx->forwaddrs, ai, publink);
2582 sa = ISC_LIST_NEXT(sa, link);
2586 * If the forwarding policy is "only", we don't need the addresses
2587 * of the nameservers.
2589 if (fctx->fwdpolicy == dns_fwdpolicy_only)
2593 * Normal nameservers.
2596 stdoptions = DNS_ADBFIND_WANTEVENT | DNS_ADBFIND_EMPTYEVENT;
2597 if (fctx->restarts == 1) {
2599 * To avoid sending out a flood of queries likely to
2600 * result in NXRRSET, we suppress fetches for address
2601 * families we don't have the first time through,
2602 * provided that we have addresses in some family we
2605 * We don't want to set this option all the time, since
2606 * if fctx->restarts > 1, we've clearly been having trouble
2607 * with the addresses we had, so getting more could help.
2609 stdoptions |= DNS_ADBFIND_AVOIDFETCHES;
2611 if (res->dispatchv4 != NULL)
2612 stdoptions |= DNS_ADBFIND_INET;
2613 if (res->dispatchv6 != NULL)
2614 stdoptions |= DNS_ADBFIND_INET6;
2615 isc_stdtime_get(&now);
2617 INSIST(ISC_LIST_EMPTY(fctx->finds));
2618 INSIST(ISC_LIST_EMPTY(fctx->altfinds));
2620 for (result = dns_rdataset_first(&fctx->nameservers);
2621 result == ISC_R_SUCCESS;
2622 result = dns_rdataset_next(&fctx->nameservers))
2624 dns_rdataset_current(&fctx->nameservers, &rdata);
2626 * Extract the name from the NS record.
2628 result = dns_rdata_tostruct(&rdata, &ns, NULL);
2629 if (result != ISC_R_SUCCESS)
2632 findname(fctx, &ns.name, 0, stdoptions, 0, now,
2634 dns_rdata_reset(&rdata);
2635 dns_rdata_freestruct(&ns);
2637 if (result != ISC_R_NOMORE)
2641 * Do we need to use 6 to 4?
2643 if (need_alternate) {
2646 family = (res->dispatchv6 != NULL) ? AF_INET6 : AF_INET;
2647 for (a = ISC_LIST_HEAD(fctx->res->alternates);
2649 a = ISC_LIST_NEXT(a, link)) {
2650 if (!a->isaddress) {
2651 findname(fctx, &a->_u._n.name, a->_u._n.port,
2652 stdoptions, FCTX_ADDRINFO_FORWARDER,
2656 if (isc_sockaddr_pf(&a->_u.addr) != family)
2659 result = dns_adb_findaddrinfo(fctx->adb, &a->_u.addr,
2661 if (result == ISC_R_SUCCESS) {
2662 dns_adbaddrinfo_t *cur;
2663 ai->flags |= FCTX_ADDRINFO_FORWARDER;
2664 cur = ISC_LIST_HEAD(fctx->altaddrs);
2665 while (cur != NULL && cur->srtt < ai->srtt)
2666 cur = ISC_LIST_NEXT(cur, publink);
2668 ISC_LIST_INSERTBEFORE(fctx->altaddrs,
2671 ISC_LIST_APPEND(fctx->altaddrs, ai,
2679 * Mark all known bad servers.
2681 all_bad = mark_bad(fctx);
2688 * We've got no addresses.
2690 if (fctx->pending > 0) {
2692 * We're fetching the addresses, but don't have any
2693 * yet. Tell the caller to wait for an answer.
2695 result = DNS_R_WAIT;
2698 * We've lost completely. We don't know any
2699 * addresses, and the ADB has told us it can't get
2702 FCTXTRACE("no addresses");
2703 result = ISC_R_FAILURE;
2707 * We've found some addresses. We might still be looking
2708 * for more addresses.
2711 result = ISC_R_SUCCESS;
2718 possibly_mark(fetchctx_t *fctx, dns_adbaddrinfo_t *addr)
2721 char buf[ISC_NETADDR_FORMATSIZE];
2723 isc_boolean_t aborted = ISC_FALSE;
2724 isc_boolean_t bogus;
2725 dns_acl_t *blackhole;
2726 isc_netaddr_t ipaddr;
2727 dns_peer_t *peer = NULL;
2728 dns_resolver_t *res;
2729 const char *msg = NULL;
2731 sa = &addr->sockaddr;
2734 isc_netaddr_fromsockaddr(&ipaddr, sa);
2735 blackhole = dns_dispatchmgr_getblackhole(res->dispatchmgr);
2736 (void) dns_peerlist_peerbyaddr(res->view->peers, &ipaddr, &peer);
2738 if (blackhole != NULL) {
2741 if (dns_acl_match(&ipaddr, NULL, blackhole,
2743 &match, NULL) == ISC_R_SUCCESS &&
2749 dns_peer_getbogus(peer, &bogus) == ISC_R_SUCCESS &&
2754 addr->flags |= FCTX_ADDRINFO_MARK;
2755 msg = "ignoring blackholed / bogus server: ";
2756 } else if (isc_sockaddr_ismulticast(sa)) {
2757 addr->flags |= FCTX_ADDRINFO_MARK;
2758 msg = "ignoring multicast address: ";
2759 } else if (isc_sockaddr_isexperimental(sa)) {
2760 addr->flags |= FCTX_ADDRINFO_MARK;
2761 msg = "ignoring experimental address: ";
2762 } else if (sa->type.sa.sa_family != AF_INET6) {
2764 } else if (IN6_IS_ADDR_V4MAPPED(&sa->type.sin6.sin6_addr)) {
2765 addr->flags |= FCTX_ADDRINFO_MARK;
2766 msg = "ignoring IPv6 mapped IPV4 address: ";
2767 } else if (IN6_IS_ADDR_V4COMPAT(&sa->type.sin6.sin6_addr)) {
2768 addr->flags |= FCTX_ADDRINFO_MARK;
2769 msg = "ignoring IPv6 compatibility IPV4 address: ";
2773 if (!isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(3)))
2776 isc_netaddr_fromsockaddr(&na, sa);
2777 isc_netaddr_format(&na, buf, sizeof(buf));
2778 FCTXTRACE2(msg, buf);
2781 static inline dns_adbaddrinfo_t *
2782 fctx_nextaddress(fetchctx_t *fctx) {
2783 dns_adbfind_t *find, *start;
2784 dns_adbaddrinfo_t *addrinfo;
2785 dns_adbaddrinfo_t *faddrinfo;
2788 * Return the next untried address, if any.
2792 * Find the first unmarked forwarder (if any).
2794 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
2796 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2797 if (!UNMARKED(addrinfo))
2799 possibly_mark(fctx, addrinfo);
2800 if (UNMARKED(addrinfo)) {
2801 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2808 * No forwarders. Move to the next find.
2811 fctx->attributes |= FCTX_ATTR_TRIEDFIND;
2815 find = ISC_LIST_HEAD(fctx->finds);
2817 find = ISC_LIST_NEXT(find, publink);
2819 find = ISC_LIST_HEAD(fctx->finds);
2823 * Find the first unmarked addrinfo.
2829 for (addrinfo = ISC_LIST_HEAD(find->list);
2831 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2832 if (!UNMARKED(addrinfo))
2834 possibly_mark(fctx, addrinfo);
2835 if (UNMARKED(addrinfo)) {
2836 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2840 if (addrinfo != NULL)
2842 find = ISC_LIST_NEXT(find, publink);
2844 find = ISC_LIST_HEAD(fctx->finds);
2845 } while (find != start);
2849 if (addrinfo != NULL)
2853 * No nameservers left. Try alternates.
2856 fctx->attributes |= FCTX_ATTR_TRIEDALT;
2858 find = fctx->altfind;
2860 find = ISC_LIST_HEAD(fctx->altfinds);
2862 find = ISC_LIST_NEXT(find, publink);
2864 find = ISC_LIST_HEAD(fctx->altfinds);
2868 * Find the first unmarked addrinfo.
2874 for (addrinfo = ISC_LIST_HEAD(find->list);
2876 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2877 if (!UNMARKED(addrinfo))
2879 possibly_mark(fctx, addrinfo);
2880 if (UNMARKED(addrinfo)) {
2881 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2885 if (addrinfo != NULL)
2887 find = ISC_LIST_NEXT(find, publink);
2889 find = ISC_LIST_HEAD(fctx->altfinds);
2890 } while (find != start);
2893 faddrinfo = addrinfo;
2896 * See if we have a better alternate server by address.
2899 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
2901 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2902 if (!UNMARKED(addrinfo))
2904 possibly_mark(fctx, addrinfo);
2905 if (UNMARKED(addrinfo) &&
2906 (faddrinfo == NULL ||
2907 addrinfo->srtt < faddrinfo->srtt)) {
2908 if (faddrinfo != NULL)
2909 faddrinfo->flags &= ~FCTX_ADDRINFO_MARK;
2910 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2915 if (addrinfo == NULL) {
2916 addrinfo = faddrinfo;
2917 fctx->altfind = find;
2924 fctx_try(fetchctx_t *fctx, isc_boolean_t retrying) {
2925 isc_result_t result;
2926 dns_adbaddrinfo_t *addrinfo;
2930 REQUIRE(!ADDRWAIT(fctx));
2932 addrinfo = fctx_nextaddress(fctx);
2933 if (addrinfo == NULL) {
2935 * We have no more addresses. Start over.
2937 fctx_cancelqueries(fctx, ISC_TRUE);
2938 fctx_cleanupfinds(fctx);
2939 fctx_cleanupaltfinds(fctx);
2940 fctx_cleanupforwaddrs(fctx);
2941 fctx_cleanupaltaddrs(fctx);
2942 result = fctx_getaddresses(fctx);
2943 if (result == DNS_R_WAIT) {
2945 * Sleep waiting for addresses.
2947 FCTXTRACE("addrwait");
2948 fctx->attributes |= FCTX_ATTR_ADDRWAIT;
2950 } else if (result != ISC_R_SUCCESS) {
2952 * Something bad happened.
2954 fctx_done(fctx, result, __LINE__);
2958 addrinfo = fctx_nextaddress(fctx);
2960 * While we may have addresses from the ADB, they
2961 * might be bad ones. In this case, return SERVFAIL.
2963 if (addrinfo == NULL) {
2964 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
2969 result = fctx_query(fctx, addrinfo, fctx->options);
2970 if (result != ISC_R_SUCCESS)
2971 fctx_done(fctx, result, __LINE__);
2973 inc_stats(fctx->res, dns_resstatscounter_retry);
2976 static isc_boolean_t
2977 fctx_destroy(fetchctx_t *fctx) {
2978 dns_resolver_t *res;
2979 unsigned int bucketnum;
2980 isc_sockaddr_t *sa, *next_sa;
2983 * Caller must be holding the bucket lock.
2986 REQUIRE(VALID_FCTX(fctx));
2987 REQUIRE(fctx->state == fetchstate_done ||
2988 fctx->state == fetchstate_init);
2989 REQUIRE(ISC_LIST_EMPTY(fctx->events));
2990 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
2991 REQUIRE(ISC_LIST_EMPTY(fctx->finds));
2992 REQUIRE(ISC_LIST_EMPTY(fctx->altfinds));
2993 REQUIRE(fctx->pending == 0);
2994 REQUIRE(fctx->references == 0);
2995 REQUIRE(ISC_LIST_EMPTY(fctx->validators));
2997 FCTXTRACE("destroy");
3000 bucketnum = fctx->bucketnum;
3002 ISC_LIST_UNLINK(res->buckets[bucketnum].fctxs, fctx, link);
3007 for (sa = ISC_LIST_HEAD(fctx->bad);
3010 next_sa = ISC_LIST_NEXT(sa, link);
3011 ISC_LIST_UNLINK(fctx->bad, sa, link);
3012 isc_mem_put(res->buckets[bucketnum].mctx, sa, sizeof(*sa));
3015 for (sa = ISC_LIST_HEAD(fctx->edns);
3018 next_sa = ISC_LIST_NEXT(sa, link);
3019 ISC_LIST_UNLINK(fctx->edns, sa, link);
3020 isc_mem_put(res->buckets[bucketnum].mctx, sa, sizeof(*sa));
3023 for (sa = ISC_LIST_HEAD(fctx->edns512);
3026 next_sa = ISC_LIST_NEXT(sa, link);
3027 ISC_LIST_UNLINK(fctx->edns512, sa, link);
3028 isc_mem_put(res->buckets[bucketnum].mctx, sa, sizeof(*sa));
3031 isc_timer_detach(&fctx->timer);
3032 dns_message_destroy(&fctx->rmessage);
3033 dns_message_destroy(&fctx->qmessage);
3034 if (dns_name_countlabels(&fctx->domain) > 0)
3035 dns_name_free(&fctx->domain, res->buckets[bucketnum].mctx);
3036 if (dns_rdataset_isassociated(&fctx->nameservers))
3037 dns_rdataset_disassociate(&fctx->nameservers);
3038 dns_name_free(&fctx->name, res->buckets[bucketnum].mctx);
3039 dns_db_detach(&fctx->cache);
3040 dns_adb_detach(&fctx->adb);
3041 isc_mem_free(res->buckets[bucketnum].mctx, fctx->info);
3042 isc_mem_put(res->buckets[bucketnum].mctx, fctx, sizeof(*fctx));
3046 UNLOCK(&res->nlock);
3048 if (res->buckets[bucketnum].exiting &&
3049 ISC_LIST_EMPTY(res->buckets[bucketnum].fctxs))
3056 * Fetch event handlers.
3060 fctx_timeout(isc_task_t *task, isc_event_t *event) {
3061 fetchctx_t *fctx = event->ev_arg;
3062 isc_timerevent_t *tevent = (isc_timerevent_t *)event;
3065 REQUIRE(VALID_FCTX(fctx));
3069 FCTXTRACE("timeout");
3071 inc_stats(fctx->res, dns_resstatscounter_querytimeout);
3073 if (event->ev_type == ISC_TIMEREVENT_LIFE) {
3074 fctx->reason = NULL;
3075 fctx_done(fctx, ISC_R_TIMEDOUT, __LINE__);
3077 isc_result_t result;
3080 fctx->timeout = ISC_TRUE;
3082 * We could cancel the running queries here, or we could let
3083 * them keep going. Since we normally use separate sockets for
3084 * different queries, we adopt the former approach to reduce
3085 * the number of open sockets: cancel the oldest query if it
3086 * expired after the query had started (this is usually the
3087 * case but is not always so, depending on the task schedule
3090 query = ISC_LIST_HEAD(fctx->queries);
3091 if (query != NULL &&
3092 isc_time_compare(&tevent->due, &query->start) >= 0) {
3093 fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
3095 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
3097 * Our timer has triggered. Reestablish the fctx lifetime
3100 result = fctx_starttimer(fctx);
3101 if (result != ISC_R_SUCCESS)
3102 fctx_done(fctx, result, __LINE__);
3107 fctx_try(fctx, ISC_TRUE);
3110 isc_event_free(&event);
3114 fctx_shutdown(fetchctx_t *fctx) {
3115 isc_event_t *cevent;
3118 * Start the shutdown process for fctx, if it isn't already underway.
3121 FCTXTRACE("shutdown");
3124 * The caller must be holding the appropriate bucket lock.
3127 if (fctx->want_shutdown)
3130 fctx->want_shutdown = ISC_TRUE;
3133 * Unless we're still initializing (in which case the
3134 * control event is still outstanding), we need to post
3135 * the control event to tell the fetch we want it to
3138 if (fctx->state != fetchstate_init) {
3139 cevent = &fctx->control_event;
3140 isc_task_send(fctx->res->buckets[fctx->bucketnum].task,
3146 fctx_doshutdown(isc_task_t *task, isc_event_t *event) {
3147 fetchctx_t *fctx = event->ev_arg;
3148 isc_boolean_t bucket_empty = ISC_FALSE;
3149 dns_resolver_t *res;
3150 unsigned int bucketnum;
3151 dns_validator_t *validator;
3153 REQUIRE(VALID_FCTX(fctx));
3158 bucketnum = fctx->bucketnum;
3160 FCTXTRACE("doshutdown");
3163 * An fctx that is shutting down is no longer in ADDRWAIT mode.
3165 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
3168 * Cancel all pending validators. Note that this must be done
3169 * without the bucket lock held, since that could cause deadlock.
3171 validator = ISC_LIST_HEAD(fctx->validators);
3172 while (validator != NULL) {
3173 dns_validator_cancel(validator);
3174 validator = ISC_LIST_NEXT(validator, link);
3177 if (fctx->nsfetch != NULL)
3178 dns_resolver_cancelfetch(fctx->nsfetch);
3181 * Shut down anything that is still running on behalf of this
3182 * fetch. To avoid deadlock with the ADB, we must do this
3183 * before we lock the bucket lock.
3185 fctx_stopeverything(fctx, ISC_FALSE);
3187 LOCK(&res->buckets[bucketnum].lock);
3189 fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN;
3191 INSIST(fctx->state == fetchstate_active ||
3192 fctx->state == fetchstate_done);
3193 INSIST(fctx->want_shutdown);
3195 if (fctx->state != fetchstate_done) {
3196 fctx->state = fetchstate_done;
3197 fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__);
3200 if (fctx->references == 0 && fctx->pending == 0 &&
3201 fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators))
3202 bucket_empty = fctx_destroy(fctx);
3204 UNLOCK(&res->buckets[bucketnum].lock);
3211 fctx_start(isc_task_t *task, isc_event_t *event) {
3212 fetchctx_t *fctx = event->ev_arg;
3213 isc_boolean_t done = ISC_FALSE, bucket_empty = ISC_FALSE;
3214 dns_resolver_t *res;
3215 unsigned int bucketnum;
3217 REQUIRE(VALID_FCTX(fctx));
3222 bucketnum = fctx->bucketnum;
3226 LOCK(&res->buckets[bucketnum].lock);
3228 INSIST(fctx->state == fetchstate_init);
3229 if (fctx->want_shutdown) {
3231 * We haven't started this fctx yet, and we've been requested
3234 fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN;
3235 fctx->state = fetchstate_done;
3236 fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__);
3238 * Since we haven't started, we INSIST that we have no
3239 * pending ADB finds and no pending validations.
3241 INSIST(fctx->pending == 0);
3242 INSIST(fctx->nqueries == 0);
3243 INSIST(ISC_LIST_EMPTY(fctx->validators));
3244 if (fctx->references == 0) {
3246 * It's now safe to destroy this fctx.
3248 bucket_empty = fctx_destroy(fctx);
3253 * Normal fctx startup.
3255 fctx->state = fetchstate_active;
3257 * Reset the control event for later use in shutting down
3260 ISC_EVENT_INIT(event, sizeof(*event), 0, NULL,
3261 DNS_EVENT_FETCHCONTROL, fctx_doshutdown, fctx,
3265 UNLOCK(&res->buckets[bucketnum].lock);
3268 isc_result_t result;
3271 * All is well. Start working on the fetch.
3273 result = fctx_starttimer(fctx);
3274 if (result != ISC_R_SUCCESS)
3275 fctx_done(fctx, result, __LINE__);
3277 fctx_try(fctx, ISC_FALSE);
3278 } else if (bucket_empty)
3283 * Fetch Creation, Joining, and Cancelation.
3286 static inline isc_result_t
3287 fctx_join(fetchctx_t *fctx, isc_task_t *task, isc_sockaddr_t *client,
3288 dns_messageid_t id, isc_taskaction_t action, void *arg,
3289 dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
3293 dns_fetchevent_t *event;
3298 * We store the task we're going to send this event to in the
3299 * sender field. We'll make the fetch the sender when we actually
3303 isc_task_attach(task, &clone);
3304 event = (dns_fetchevent_t *)
3305 isc_event_allocate(fctx->res->mctx, clone, DNS_EVENT_FETCHDONE,
3306 action, arg, sizeof(*event));
3307 if (event == NULL) {
3308 isc_task_detach(&clone);
3309 return (ISC_R_NOMEMORY);
3311 event->result = DNS_R_SERVFAIL;
3312 event->qtype = fctx->type;
3315 event->rdataset = rdataset;
3316 event->sigrdataset = sigrdataset;
3317 event->fetch = fetch;
3318 event->client = client;
3320 dns_fixedname_init(&event->foundname);
3323 * Make sure that we can store the sigrdataset in the
3324 * first event if it is needed by any of the events.
3326 if (event->sigrdataset != NULL)
3327 ISC_LIST_PREPEND(fctx->events, event, ev_link);
3329 ISC_LIST_APPEND(fctx->events, event, ev_link);
3332 fetch->magic = DNS_FETCH_MAGIC;
3333 fetch->private = fctx;
3335 return (ISC_R_SUCCESS);
3339 fctx_create(dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type,
3340 dns_name_t *domain, dns_rdataset_t *nameservers,
3341 unsigned int options, unsigned int bucketnum, fetchctx_t **fctxp)
3344 isc_result_t result;
3345 isc_result_t iresult;
3346 isc_interval_t interval;
3347 dns_fixedname_t fixed;
3348 unsigned int findoptions = 0;
3349 char buf[DNS_NAME_FORMATSIZE + DNS_RDATATYPE_FORMATSIZE];
3350 char typebuf[DNS_RDATATYPE_FORMATSIZE];
3354 * Caller must be holding the lock for bucket number 'bucketnum'.
3356 REQUIRE(fctxp != NULL && *fctxp == NULL);
3358 fctx = isc_mem_get(res->buckets[bucketnum].mctx, sizeof(*fctx));
3360 return (ISC_R_NOMEMORY);
3361 dns_name_format(name, buf, sizeof(buf));
3362 dns_rdatatype_format(type, typebuf, sizeof(typebuf));
3363 strcat(buf, "/"); /* checked */
3364 strcat(buf, typebuf); /* checked */
3365 fctx->info = isc_mem_strdup(res->buckets[bucketnum].mctx, buf);
3366 if (fctx->info == NULL) {
3367 result = ISC_R_NOMEMORY;
3370 FCTXTRACE("create");
3371 dns_name_init(&fctx->name, NULL);
3372 result = dns_name_dup(name, res->buckets[bucketnum].mctx, &fctx->name);
3373 if (result != ISC_R_SUCCESS)
3375 dns_name_init(&fctx->domain, NULL);
3376 dns_rdataset_init(&fctx->nameservers);
3379 fctx->options = options;
3381 * Note! We do not attach to the task. We are relying on the
3382 * resolver to ensure that this task doesn't go away while we are
3386 fctx->references = 0;
3387 fctx->bucketnum = bucketnum;
3388 fctx->state = fetchstate_init;
3389 fctx->want_shutdown = ISC_FALSE;
3390 fctx->cloned = ISC_FALSE;
3391 ISC_LIST_INIT(fctx->queries);
3392 ISC_LIST_INIT(fctx->finds);
3393 ISC_LIST_INIT(fctx->altfinds);
3394 ISC_LIST_INIT(fctx->forwaddrs);
3395 ISC_LIST_INIT(fctx->altaddrs);
3396 ISC_LIST_INIT(fctx->forwarders);
3397 fctx->fwdpolicy = dns_fwdpolicy_none;
3398 ISC_LIST_INIT(fctx->bad);
3399 ISC_LIST_INIT(fctx->edns);
3400 ISC_LIST_INIT(fctx->edns512);
3401 ISC_LIST_INIT(fctx->validators);
3402 fctx->validator = NULL;
3404 fctx->altfind = NULL;
3407 fctx->querysent = 0;
3408 fctx->referrals = 0;
3409 TIME_NOW(&fctx->start);
3411 fctx->lamecount = 0;
3417 fctx->result = ISC_R_FAILURE;
3418 fctx->vresult = ISC_R_SUCCESS;
3419 fctx->exitline = -1; /* sentinel */
3420 fctx->logged = ISC_FALSE;
3421 fctx->attributes = 0;
3422 fctx->spilled = ISC_FALSE;
3424 fctx->reason = NULL;
3425 fctx->timeout = ISC_FALSE;
3427 dns_name_init(&fctx->nsname, NULL);
3428 fctx->nsfetch = NULL;
3429 dns_rdataset_init(&fctx->nsrrset);
3431 if (domain == NULL) {
3432 dns_forwarders_t *forwarders = NULL;
3433 unsigned int labels;
3434 dns_name_t *fwdname = name;
3437 * DS records are found in the parent server.
3438 * Strip label to get the correct forwarder (if any).
3440 if (dns_rdatatype_atparent(fctx->type) &&
3441 dns_name_countlabels(name) > 1) {
3442 dns_name_init(&suffix, NULL);
3443 labels = dns_name_countlabels(name);
3444 dns_name_getlabelsequence(name, 1, labels - 1, &suffix);
3447 dns_fixedname_init(&fixed);
3448 domain = dns_fixedname_name(&fixed);
3449 result = dns_fwdtable_find2(fctx->res->view->fwdtable, fwdname,
3450 domain, &forwarders);
3451 if (result == ISC_R_SUCCESS)
3452 fctx->fwdpolicy = forwarders->fwdpolicy;
3454 if (fctx->fwdpolicy != dns_fwdpolicy_only) {
3456 * The caller didn't supply a query domain and
3457 * nameservers, and we're not in forward-only mode,
3458 * so find the best nameservers to use.
3460 if (dns_rdatatype_atparent(fctx->type))
3461 findoptions |= DNS_DBFIND_NOEXACT;
3462 result = dns_view_findzonecut(res->view, name, domain,
3463 0, findoptions, ISC_TRUE,
3466 if (result != ISC_R_SUCCESS)
3468 result = dns_name_dup(domain,
3469 res->buckets[bucketnum].mctx,
3471 if (result != ISC_R_SUCCESS) {
3472 dns_rdataset_disassociate(&fctx->nameservers);
3477 * We're in forward-only mode. Set the query domain.
3479 result = dns_name_dup(domain,
3480 res->buckets[bucketnum].mctx,
3482 if (result != ISC_R_SUCCESS)
3486 result = dns_name_dup(domain,
3487 res->buckets[bucketnum].mctx,
3489 if (result != ISC_R_SUCCESS)
3491 dns_rdataset_clone(nameservers, &fctx->nameservers);
3494 INSIST(dns_name_issubdomain(&fctx->name, &fctx->domain));
3496 fctx->qmessage = NULL;
3497 result = dns_message_create(res->buckets[bucketnum].mctx,
3498 DNS_MESSAGE_INTENTRENDER,
3501 if (result != ISC_R_SUCCESS)
3502 goto cleanup_domain;
3504 fctx->rmessage = NULL;
3505 result = dns_message_create(res->buckets[bucketnum].mctx,
3506 DNS_MESSAGE_INTENTPARSE,
3509 if (result != ISC_R_SUCCESS)
3510 goto cleanup_qmessage;
3513 * Compute an expiration time for the entire fetch.
3515 isc_interval_set(&interval, 30, 0); /* XXXRTH constant */
3516 iresult = isc_time_nowplusinterval(&fctx->expires, &interval);
3517 if (iresult != ISC_R_SUCCESS) {
3518 UNEXPECTED_ERROR(__FILE__, __LINE__,
3519 "isc_time_nowplusinterval: %s",
3520 isc_result_totext(iresult));
3521 result = ISC_R_UNEXPECTED;
3522 goto cleanup_rmessage;
3526 * Default retry interval initialization. We set the interval now
3527 * mostly so it won't be uninitialized. It will be set to the
3528 * correct value before a query is issued.
3530 isc_interval_set(&fctx->interval, 2, 0);
3533 * Create an inactive timer. It will be made active when the fetch
3534 * is actually started.
3537 iresult = isc_timer_create(res->timermgr, isc_timertype_inactive,
3539 res->buckets[bucketnum].task, fctx_timeout,
3540 fctx, &fctx->timer);
3541 if (iresult != ISC_R_SUCCESS) {
3542 UNEXPECTED_ERROR(__FILE__, __LINE__,
3543 "isc_timer_create: %s",
3544 isc_result_totext(iresult));
3545 result = ISC_R_UNEXPECTED;
3546 goto cleanup_rmessage;
3550 * Attach to the view's cache and adb.
3553 dns_db_attach(res->view->cachedb, &fctx->cache);
3555 dns_adb_attach(res->view->adb, &fctx->adb);
3557 ISC_LIST_INIT(fctx->events);
3558 ISC_LINK_INIT(fctx, link);
3559 fctx->magic = FCTX_MAGIC;
3561 ISC_LIST_APPEND(res->buckets[bucketnum].fctxs, fctx, link);
3565 UNLOCK(&res->nlock);
3569 return (ISC_R_SUCCESS);
3572 dns_message_destroy(&fctx->rmessage);
3575 dns_message_destroy(&fctx->qmessage);
3578 if (dns_name_countlabels(&fctx->domain) > 0)
3579 dns_name_free(&fctx->domain, res->buckets[bucketnum].mctx);
3580 if (dns_rdataset_isassociated(&fctx->nameservers))
3581 dns_rdataset_disassociate(&fctx->nameservers);
3584 dns_name_free(&fctx->name, res->buckets[bucketnum].mctx);
3587 isc_mem_free(res->buckets[bucketnum].mctx, fctx->info);
3590 isc_mem_put(res->buckets[bucketnum].mctx, fctx, sizeof(*fctx));
3598 static inline isc_boolean_t
3599 is_lame(fetchctx_t *fctx) {
3600 dns_message_t *message = fctx->rmessage;
3602 dns_rdataset_t *rdataset;
3603 isc_result_t result;
3605 if (message->rcode != dns_rcode_noerror &&
3606 message->rcode != dns_rcode_nxdomain)
3609 if (message->counts[DNS_SECTION_ANSWER] != 0)
3612 if (message->counts[DNS_SECTION_AUTHORITY] == 0)
3615 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
3616 while (result == ISC_R_SUCCESS) {
3618 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
3619 for (rdataset = ISC_LIST_HEAD(name->list);
3621 rdataset = ISC_LIST_NEXT(rdataset, link)) {
3622 dns_namereln_t namereln;
3624 unsigned int labels;
3625 if (rdataset->type != dns_rdatatype_ns)
3627 namereln = dns_name_fullcompare(name, &fctx->domain,
3629 if (namereln == dns_namereln_equal &&
3630 (message->flags & DNS_MESSAGEFLAG_AA) != 0)
3632 if (namereln == dns_namereln_subdomain)
3636 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
3643 log_lame(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo) {
3644 char namebuf[DNS_NAME_FORMATSIZE];
3645 char domainbuf[DNS_NAME_FORMATSIZE];
3646 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
3648 dns_name_format(&fctx->name, namebuf, sizeof(namebuf));
3649 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
3650 isc_sockaddr_format(&addrinfo->sockaddr, addrbuf, sizeof(addrbuf));
3651 isc_log_write(dns_lctx, DNS_LOGCATEGORY_LAME_SERVERS,
3652 DNS_LOGMODULE_RESOLVER, ISC_LOG_INFO,
3653 "lame server resolving '%s' (in '%s'?): %s",
3654 namebuf, domainbuf, addrbuf);
3657 static inline isc_result_t
3658 same_question(fetchctx_t *fctx) {
3659 isc_result_t result;
3660 dns_message_t *message = fctx->rmessage;
3662 dns_rdataset_t *rdataset;
3665 * Caller must be holding the fctx lock.
3669 * XXXRTH Currently we support only one question.
3671 if (message->counts[DNS_SECTION_QUESTION] != 1)
3672 return (DNS_R_FORMERR);
3674 result = dns_message_firstname(message, DNS_SECTION_QUESTION);
3675 if (result != ISC_R_SUCCESS)
3678 dns_message_currentname(message, DNS_SECTION_QUESTION, &name);
3679 rdataset = ISC_LIST_HEAD(name->list);
3680 INSIST(rdataset != NULL);
3681 INSIST(ISC_LIST_NEXT(rdataset, link) == NULL);
3682 if (fctx->type != rdataset->type ||
3683 fctx->res->rdclass != rdataset->rdclass ||
3684 !dns_name_equal(&fctx->name, name))
3685 return (DNS_R_FORMERR);
3687 return (ISC_R_SUCCESS);
3691 clone_results(fetchctx_t *fctx) {
3692 dns_fetchevent_t *event, *hevent;
3693 isc_result_t result;
3694 dns_name_t *name, *hname;
3696 FCTXTRACE("clone_results");
3699 * Set up any other events to have the same data as the first
3702 * Caller must be holding the appropriate lock.
3705 fctx->cloned = ISC_TRUE;
3706 hevent = ISC_LIST_HEAD(fctx->events);
3709 hname = dns_fixedname_name(&hevent->foundname);
3710 for (event = ISC_LIST_NEXT(hevent, ev_link);
3712 event = ISC_LIST_NEXT(event, ev_link)) {
3713 name = dns_fixedname_name(&event->foundname);
3714 result = dns_name_copy(hname, name, NULL);
3715 if (result != ISC_R_SUCCESS)
3716 event->result = result;
3718 event->result = hevent->result;
3719 dns_db_attach(hevent->db, &event->db);
3720 dns_db_attachnode(hevent->db, hevent->node, &event->node);
3721 INSIST(hevent->rdataset != NULL);
3722 INSIST(event->rdataset != NULL);
3723 if (dns_rdataset_isassociated(hevent->rdataset))
3724 dns_rdataset_clone(hevent->rdataset, event->rdataset);
3725 INSIST(! (hevent->sigrdataset == NULL &&
3726 event->sigrdataset != NULL));
3727 if (hevent->sigrdataset != NULL &&
3728 dns_rdataset_isassociated(hevent->sigrdataset) &&
3729 event->sigrdataset != NULL)
3730 dns_rdataset_clone(hevent->sigrdataset,
3731 event->sigrdataset);
3735 #define CACHE(r) (((r)->attributes & DNS_RDATASETATTR_CACHE) != 0)
3736 #define ANSWER(r) (((r)->attributes & DNS_RDATASETATTR_ANSWER) != 0)
3737 #define ANSWERSIG(r) (((r)->attributes & DNS_RDATASETATTR_ANSWERSIG) != 0)
3738 #define EXTERNAL(r) (((r)->attributes & DNS_RDATASETATTR_EXTERNAL) != 0)
3739 #define CHAINING(r) (((r)->attributes & DNS_RDATASETATTR_CHAINING) != 0)
3740 #define CHASE(r) (((r)->attributes & DNS_RDATASETATTR_CHASE) != 0)
3741 #define CHECKNAMES(r) (((r)->attributes & DNS_RDATASETATTR_CHECKNAMES) != 0)
3745 * Destroy '*fctx' if it is ready to be destroyed (i.e., if it has
3746 * no references and is no longer waiting for any events). If this
3747 * was the last fctx in the resolver, destroy the resolver.
3750 * '*fctx' is shutting down.
3753 maybe_destroy(fetchctx_t *fctx) {
3754 unsigned int bucketnum;
3755 isc_boolean_t bucket_empty = ISC_FALSE;
3756 dns_resolver_t *res = fctx->res;
3757 dns_validator_t *validator, *next_validator;
3759 REQUIRE(SHUTTINGDOWN(fctx));
3761 if (fctx->pending != 0 || fctx->nqueries != 0)
3764 for (validator = ISC_LIST_HEAD(fctx->validators);
3765 validator != NULL; validator = next_validator) {
3766 next_validator = ISC_LIST_NEXT(validator, link);
3767 dns_validator_cancel(validator);
3769 * If this is a active validator wait for the cancel
3770 * to complete before calling dns_validator_destroy().
3772 if (validator == fctx->validator)
3774 ISC_LIST_UNLINK(fctx->validators, validator, link);
3775 dns_validator_destroy(&validator);
3778 bucketnum = fctx->bucketnum;
3779 LOCK(&res->buckets[bucketnum].lock);
3780 if (fctx->references == 0 && ISC_LIST_EMPTY(fctx->validators))
3781 bucket_empty = fctx_destroy(fctx);
3782 UNLOCK(&res->buckets[bucketnum].lock);
3789 * The validator has finished.
3792 validated(isc_task_t *task, isc_event_t *event) {
3793 isc_result_t result = ISC_R_SUCCESS;
3794 isc_result_t eresult = ISC_R_SUCCESS;
3797 dns_validatorevent_t *vevent;
3798 dns_fetchevent_t *hevent;
3799 dns_rdataset_t *ardataset = NULL;
3800 dns_rdataset_t *asigrdataset = NULL;
3801 dns_dbnode_t *node = NULL;
3802 isc_boolean_t negative;
3803 isc_boolean_t chaining;
3804 isc_boolean_t sentresponse;
3806 dns_dbnode_t *nsnode = NULL;
3808 dns_rdataset_t *rdataset;
3809 dns_rdataset_t *sigrdataset;
3810 dns_valarg_t *valarg;
3811 dns_adbaddrinfo_t *addrinfo;
3813 UNUSED(task); /* for now */
3815 REQUIRE(event->ev_type == DNS_EVENT_VALIDATORDONE);
3816 valarg = event->ev_arg;
3817 fctx = valarg->fctx;
3818 addrinfo = valarg->addrinfo;
3819 REQUIRE(VALID_FCTX(fctx));
3820 REQUIRE(!ISC_LIST_EMPTY(fctx->validators));
3822 vevent = (dns_validatorevent_t *)event;
3824 FCTXTRACE("received validation completion event");
3826 ISC_LIST_UNLINK(fctx->validators, vevent->validator, link);
3827 fctx->validator = NULL;
3830 * Destroy the validator early so that we can
3831 * destroy the fctx if necessary.
3833 dns_validator_destroy(&vevent->validator);
3834 isc_mem_put(fctx->res->buckets[fctx->bucketnum].mctx,
3835 valarg, sizeof(*valarg));
3837 negative = ISC_TF(vevent->rdataset == NULL);
3839 sentresponse = ISC_TF((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0);
3842 * If shutting down, ignore the results. Check to see if we're
3843 * done waiting for validator completions and ADB pending events; if
3844 * so, destroy the fctx.
3846 if (SHUTTINGDOWN(fctx) && !sentresponse) {
3847 maybe_destroy(fctx); /* Locks bucket. */
3851 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
3854 * If chaining, we need to make sure that the right result code is
3855 * returned, and that the rdatasets are bound.
3857 if (vevent->result == ISC_R_SUCCESS &&
3859 vevent->rdataset != NULL &&
3860 CHAINING(vevent->rdataset))
3862 if (vevent->rdataset->type == dns_rdatatype_cname)
3863 eresult = DNS_R_CNAME;
3865 INSIST(vevent->rdataset->type == dns_rdatatype_dname);
3866 eresult = DNS_R_DNAME;
3868 chaining = ISC_TRUE;
3870 chaining = ISC_FALSE;
3873 * Either we're not shutting down, or we are shutting down but want
3874 * to cache the result anyway (if this was a validation started by
3875 * a query with cd set)
3878 hevent = ISC_LIST_HEAD(fctx->events);
3879 if (hevent != NULL) {
3880 if (!negative && !chaining &&
3881 (fctx->type == dns_rdatatype_any ||
3882 fctx->type == dns_rdatatype_rrsig ||
3883 fctx->type == dns_rdatatype_sig)) {
3885 * Don't bind rdatasets; the caller
3886 * will iterate the node.
3889 ardataset = hevent->rdataset;
3890 asigrdataset = hevent->sigrdataset;
3894 if (vevent->result != ISC_R_SUCCESS) {
3895 FCTXTRACE("validation failed");
3896 inc_stats(fctx->res, dns_resstatscounter_valfail);
3898 fctx->vresult = vevent->result;
3899 result = ISC_R_NOTFOUND;
3900 if (vevent->rdataset != NULL)
3901 result = dns_db_findnode(fctx->cache, vevent->name,
3903 if (result == ISC_R_SUCCESS)
3904 (void)dns_db_deleterdataset(fctx->cache, node, NULL,
3906 if (result == ISC_R_SUCCESS && vevent->sigrdataset != NULL)
3907 (void)dns_db_deleterdataset(fctx->cache, node, NULL,
3908 dns_rdatatype_rrsig,
3910 if (result == ISC_R_SUCCESS)
3911 dns_db_detachnode(fctx->cache, &node);
3912 result = vevent->result;
3913 add_bad(fctx, addrinfo, result, badns_validation);
3914 isc_event_free(&event);
3915 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
3916 INSIST(fctx->validator == NULL);
3917 fctx->validator = ISC_LIST_HEAD(fctx->validators);
3918 if (fctx->validator != NULL) {
3919 dns_validator_send(fctx->validator);
3920 } else if (sentresponse)
3921 fctx_done(fctx, result, __LINE__); /* Locks bucket. */
3923 fctx_try(fctx, ISC_TRUE); /* Locks bucket. */
3927 isc_stdtime_get(&now);
3930 dns_rdatatype_t covers;
3931 FCTXTRACE("nonexistence validation OK");
3933 inc_stats(fctx->res, dns_resstatscounter_valnegsuccess);
3935 if (fctx->rmessage->rcode == dns_rcode_nxdomain)
3936 covers = dns_rdatatype_any;
3938 covers = fctx->type;
3940 result = dns_db_findnode(fctx->cache, vevent->name, ISC_TRUE,
3942 if (result != ISC_R_SUCCESS)
3943 goto noanswer_response;
3946 * If we are asking for a SOA record set the cache time
3947 * to zero to facilitate locating the containing zone of
3950 ttl = fctx->res->view->maxncachettl;
3951 if (fctx->type == dns_rdatatype_soa &&
3952 covers == dns_rdatatype_any &&
3953 fctx->res->zero_no_soa_ttl)
3956 result = ncache_adderesult(fctx->rmessage, fctx->cache, node,
3958 ardataset, &eresult);
3959 if (result != ISC_R_SUCCESS)
3960 goto noanswer_response;
3961 goto answer_response;
3963 inc_stats(fctx->res, dns_resstatscounter_valsuccess);
3965 FCTXTRACE("validation OK");
3967 if (vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF] != NULL) {
3969 result = dns_rdataset_addnoqname(vevent->rdataset,
3970 vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF]);
3971 RUNTIME_CHECK(result == ISC_R_SUCCESS);
3972 INSIST(vevent->sigrdataset != NULL);
3973 vevent->sigrdataset->ttl = vevent->rdataset->ttl;
3977 * The data was already cached as pending data.
3978 * Re-cache it as secure and bind the cached
3979 * rdatasets to the first event on the fetch
3982 result = dns_db_findnode(fctx->cache, vevent->name, ISC_TRUE, &node);
3983 if (result != ISC_R_SUCCESS)
3984 goto noanswer_response;
3986 result = dns_db_addrdataset(fctx->cache, node, NULL, now,
3987 vevent->rdataset, 0, ardataset);
3988 if (result != ISC_R_SUCCESS &&
3989 result != DNS_R_UNCHANGED)
3990 goto noanswer_response;
3991 if (ardataset != NULL && ardataset->type == 0) {
3992 if (NXDOMAIN(ardataset))
3993 eresult = DNS_R_NCACHENXDOMAIN;
3995 eresult = DNS_R_NCACHENXRRSET;
3996 } else if (vevent->sigrdataset != NULL) {
3997 result = dns_db_addrdataset(fctx->cache, node, NULL, now,
3998 vevent->sigrdataset, 0,
4000 if (result != ISC_R_SUCCESS &&
4001 result != DNS_R_UNCHANGED)
4002 goto noanswer_response;
4007 * If we only deferred the destroy because we wanted to cache
4008 * the data, destroy now.
4010 dns_db_detachnode(fctx->cache, &node);
4011 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4012 if (SHUTTINGDOWN(fctx))
4013 maybe_destroy(fctx); /* Locks bucket. */
4017 if (!ISC_LIST_EMPTY(fctx->validators)) {
4019 INSIST(fctx->type == dns_rdatatype_any ||
4020 fctx->type == dns_rdatatype_rrsig ||
4021 fctx->type == dns_rdatatype_sig);
4023 * Don't send a response yet - we have
4024 * more rdatasets that still need to
4027 dns_db_detachnode(fctx->cache, &node);
4028 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4029 dns_validator_send(ISC_LIST_HEAD(fctx->validators));
4035 * Cache any NS/NSEC records that happened to be validated.
4037 result = dns_message_firstname(fctx->rmessage, DNS_SECTION_AUTHORITY);
4038 while (result == ISC_R_SUCCESS) {
4040 dns_message_currentname(fctx->rmessage, DNS_SECTION_AUTHORITY,
4042 for (rdataset = ISC_LIST_HEAD(name->list);
4044 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4045 if ((rdataset->type != dns_rdatatype_ns &&
4046 rdataset->type != dns_rdatatype_nsec) ||
4047 rdataset->trust != dns_trust_secure)
4049 for (sigrdataset = ISC_LIST_HEAD(name->list);
4050 sigrdataset != NULL;
4051 sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) {
4052 if (sigrdataset->type != dns_rdatatype_rrsig ||
4053 sigrdataset->covers != rdataset->type)
4057 if (sigrdataset == NULL ||
4058 sigrdataset->trust != dns_trust_secure)
4060 result = dns_db_findnode(fctx->cache, name, ISC_TRUE,
4062 if (result != ISC_R_SUCCESS)
4065 result = dns_db_addrdataset(fctx->cache, nsnode, NULL,
4066 now, rdataset, 0, NULL);
4067 if (result == ISC_R_SUCCESS)
4068 result = dns_db_addrdataset(fctx->cache, nsnode,
4072 dns_db_detachnode(fctx->cache, &nsnode);
4074 result = dns_message_nextname(fctx->rmessage,
4075 DNS_SECTION_AUTHORITY);
4078 result = ISC_R_SUCCESS;
4081 * Respond with an answer, positive or negative,
4082 * as opposed to an error. 'node' must be non-NULL.
4085 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4087 if (hevent != NULL) {
4088 hevent->result = eresult;
4089 RUNTIME_CHECK(dns_name_copy(vevent->name,
4090 dns_fixedname_name(&hevent->foundname), NULL)
4092 dns_db_attach(fctx->cache, &hevent->db);
4093 dns_db_transfernode(fctx->cache, &node, &hevent->node);
4094 clone_results(fctx);
4099 dns_db_detachnode(fctx->cache, &node);
4101 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4103 fctx_done(fctx, result, __LINE__); /* Locks bucket. */
4106 INSIST(node == NULL);
4107 isc_event_free(&event);
4110 static inline isc_result_t
4111 cache_name(fetchctx_t *fctx, dns_name_t *name, dns_adbaddrinfo_t *addrinfo,
4114 dns_rdataset_t *rdataset, *sigrdataset;
4115 dns_rdataset_t *addedrdataset, *ardataset, *asigrdataset;
4116 dns_rdataset_t *valrdataset = NULL, *valsigrdataset = NULL;
4117 dns_dbnode_t *node, **anodep;
4120 dns_resolver_t *res;
4121 isc_boolean_t need_validation, secure_domain, have_answer;
4122 isc_result_t result, eresult;
4123 dns_fetchevent_t *event;
4124 unsigned int options;
4127 unsigned int valoptions = 0;
4130 * The appropriate bucket lock must be held.
4134 need_validation = ISC_FALSE;
4135 secure_domain = ISC_FALSE;
4136 have_answer = ISC_FALSE;
4137 eresult = ISC_R_SUCCESS;
4138 task = res->buckets[fctx->bucketnum].task;
4141 * Is DNSSEC validation required for this name?
4143 if (res->view->enablevalidation) {
4144 result = dns_keytable_issecuredomain(res->view->secroots, name,
4146 if (result != ISC_R_SUCCESS)
4149 if (!secure_domain && res->view->dlv != NULL) {
4150 valoptions = DNS_VALIDATOR_DLV;
4151 secure_domain = ISC_TRUE;
4155 if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0)
4156 need_validation = ISC_FALSE;
4158 need_validation = secure_domain;
4164 asigrdataset = NULL;
4166 if ((name->attributes & DNS_NAMEATTR_ANSWER) != 0 &&
4168 have_answer = ISC_TRUE;
4169 event = ISC_LIST_HEAD(fctx->events);
4170 if (event != NULL) {
4172 aname = dns_fixedname_name(&event->foundname);
4173 result = dns_name_copy(name, aname, NULL);
4174 if (result != ISC_R_SUCCESS)
4176 anodep = &event->node;
4178 * If this is an ANY, SIG or RRSIG query, we're not
4179 * going to return any rdatasets, unless we encountered
4180 * a CNAME or DNAME as "the answer". In this case,
4181 * we're going to return DNS_R_CNAME or DNS_R_DNAME
4182 * and we must set up the rdatasets.
4184 if ((fctx->type != dns_rdatatype_any &&
4185 fctx->type != dns_rdatatype_rrsig &&
4186 fctx->type != dns_rdatatype_sig) ||
4187 (name->attributes & DNS_NAMEATTR_CHAINING) != 0) {
4188 ardataset = event->rdataset;
4189 asigrdataset = event->sigrdataset;
4195 * Find or create the cache node.
4198 result = dns_db_findnode(fctx->cache, name, ISC_TRUE, &node);
4199 if (result != ISC_R_SUCCESS)
4203 * Cache or validate each cacheable rdataset.
4205 fail = ISC_TF((fctx->res->options & DNS_RESOLVER_CHECKNAMESFAIL) != 0);
4206 for (rdataset = ISC_LIST_HEAD(name->list);
4208 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4209 if (!CACHE(rdataset))
4211 if (CHECKNAMES(rdataset)) {
4212 char namebuf[DNS_NAME_FORMATSIZE];
4213 char typebuf[DNS_RDATATYPE_FORMATSIZE];
4214 char classbuf[DNS_RDATATYPE_FORMATSIZE];
4216 dns_name_format(name, namebuf, sizeof(namebuf));
4217 dns_rdatatype_format(rdataset->type, typebuf,
4219 dns_rdataclass_format(rdataset->rdclass, classbuf,
4221 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
4222 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
4223 "check-names %s %s/%s/%s",
4224 fail ? "failure" : "warning",
4225 namebuf, typebuf, classbuf);
4227 if (ANSWER(rdataset)) {
4228 dns_db_detachnode(fctx->cache, &node);
4229 return (DNS_R_BADNAME);
4236 * Enforce the configure maximum cache TTL.
4238 if (rdataset->ttl > res->view->maxcachettl)
4239 rdataset->ttl = res->view->maxcachettl;
4242 * If this rrset is in a secure domain, do DNSSEC validation
4243 * for it, unless it is glue.
4245 if (secure_domain && rdataset->trust != dns_trust_glue) {
4248 * RRSIGs are validated as part of validating the
4251 if (rdataset->type == dns_rdatatype_rrsig)
4254 * Find the SIG for this rdataset, if we have it.
4256 for (sigrdataset = ISC_LIST_HEAD(name->list);
4257 sigrdataset != NULL;
4258 sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) {
4259 if (sigrdataset->type == dns_rdatatype_rrsig &&
4260 sigrdataset->covers == rdataset->type)
4263 if (sigrdataset == NULL) {
4264 if (!ANSWER(rdataset) && need_validation) {
4266 * Ignore non-answer rdatasets that
4267 * are missing signatures.
4274 * Normalize the rdataset and sigrdataset TTLs.
4276 if (sigrdataset != NULL) {
4277 rdataset->ttl = ISC_MIN(rdataset->ttl,
4279 sigrdataset->ttl = rdataset->ttl;
4283 * Reject out of bailiwick additional records
4284 * without RRSIGs as they can't possibly validate
4285 * as "secure" and as we will never never want to
4286 * store these as "answers" after validation.
4288 if (rdataset->trust == dns_trust_additional &&
4289 sigrdataset == NULL && EXTERNAL(rdataset))
4293 * XXXMPA: If we store as "answer" after validating
4294 * then we need to do bailiwick processing and
4295 * also need to track whether RRsets are in or
4296 * out of bailiwick. This will require a another
4297 * pending trust level.
4299 * Cache this rdataset/sigrdataset pair as
4300 * pending data. Track whether it was additional
4303 if (rdataset->trust == dns_trust_additional)
4304 trust = dns_trust_pending_additional;
4306 trust = dns_trust_pending_answer;
4308 rdataset->trust = trust;
4309 if (sigrdataset != NULL)
4310 sigrdataset->trust = trust;
4311 if (!need_validation || !ANSWER(rdataset)) {
4312 addedrdataset = ardataset;
4313 result = dns_db_addrdataset(fctx->cache, node,
4314 NULL, now, rdataset,
4316 if (result == DNS_R_UNCHANGED) {
4317 result = ISC_R_SUCCESS;
4318 if (!need_validation &&
4319 ardataset != NULL &&
4320 ardataset->type == 0) {
4322 * The answer in the cache is
4323 * better than the answer we
4324 * found, and is a negative
4325 * cache entry, so we must set
4326 * eresult appropriately.
4328 if (NXDOMAIN(ardataset))
4330 DNS_R_NCACHENXDOMAIN;
4333 DNS_R_NCACHENXRRSET;
4335 * We have a negative response
4336 * from the cache so don't
4337 * attempt to add the RRSIG
4343 if (result != ISC_R_SUCCESS)
4345 if (sigrdataset != NULL) {
4346 addedrdataset = asigrdataset;
4347 result = dns_db_addrdataset(fctx->cache,
4351 if (result == DNS_R_UNCHANGED)
4352 result = ISC_R_SUCCESS;
4353 if (result != ISC_R_SUCCESS)
4355 } else if (!ANSWER(rdataset))
4359 if (ANSWER(rdataset) && need_validation) {
4360 if (fctx->type != dns_rdatatype_any &&
4361 fctx->type != dns_rdatatype_rrsig &&
4362 fctx->type != dns_rdatatype_sig) {
4364 * This is The Answer. We will
4365 * validate it, but first we cache
4366 * the rest of the response - it may
4367 * contain useful keys.
4369 INSIST(valrdataset == NULL &&
4370 valsigrdataset == NULL);
4371 valrdataset = rdataset;
4372 valsigrdataset = sigrdataset;
4375 * This is one of (potentially)
4376 * multiple answers to an ANY
4377 * or SIG query. To keep things
4378 * simple, we just start the
4379 * validator right away rather
4380 * than caching first and
4381 * having to remember which
4382 * rdatasets needed validation.
4384 result = valcreate(fctx, addrinfo,
4385 name, rdataset->type,
4390 * Defer any further validations.
4391 * This prevents multiple validators
4392 * from manipulating fctx->rmessage
4395 valoptions |= DNS_VALIDATOR_DEFER;
4397 } else if (CHAINING(rdataset)) {
4398 if (rdataset->type == dns_rdatatype_cname)
4399 eresult = DNS_R_CNAME;
4401 INSIST(rdataset->type ==
4402 dns_rdatatype_dname);
4403 eresult = DNS_R_DNAME;
4406 } else if (!EXTERNAL(rdataset)) {
4408 * It's OK to cache this rdataset now.
4410 if (ANSWER(rdataset))
4411 addedrdataset = ardataset;
4412 else if (ANSWERSIG(rdataset))
4413 addedrdataset = asigrdataset;
4415 addedrdataset = NULL;
4416 if (CHAINING(rdataset)) {
4417 if (rdataset->type == dns_rdatatype_cname)
4418 eresult = DNS_R_CNAME;
4420 INSIST(rdataset->type ==
4421 dns_rdatatype_dname);
4422 eresult = DNS_R_DNAME;
4425 if (rdataset->trust == dns_trust_glue &&
4426 (rdataset->type == dns_rdatatype_ns ||
4427 (rdataset->type == dns_rdatatype_rrsig &&
4428 rdataset->covers == dns_rdatatype_ns))) {
4430 * If the trust level is 'dns_trust_glue'
4431 * then we are adding data from a referral
4432 * we got while executing the search algorithm.
4433 * New referral data always takes precedence
4434 * over the existing cache contents.
4436 options = DNS_DBADD_FORCE;
4440 * Now we can add the rdataset.
4442 result = dns_db_addrdataset(fctx->cache,
4447 if (result == DNS_R_UNCHANGED) {
4448 if (ANSWER(rdataset) &&
4449 ardataset != NULL &&
4450 ardataset->type == 0) {
4452 * The answer in the cache is better
4453 * than the answer we found, and is
4454 * a negative cache entry, so we
4455 * must set eresult appropriately.
4457 if (NXDOMAIN(ardataset))
4458 eresult = DNS_R_NCACHENXDOMAIN;
4460 eresult = DNS_R_NCACHENXRRSET;
4462 result = ISC_R_SUCCESS;
4463 } else if (result != ISC_R_SUCCESS)
4468 if (valrdataset != NULL)
4469 result = valcreate(fctx, addrinfo, name, fctx->type,
4470 valrdataset, valsigrdataset, valoptions,
4473 if (result == ISC_R_SUCCESS && have_answer) {
4474 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4475 if (event != NULL) {
4477 * Negative results must be indicated in event->result.
4479 if (dns_rdataset_isassociated(event->rdataset) &&
4480 event->rdataset->type == dns_rdatatype_none) {
4481 INSIST(eresult == DNS_R_NCACHENXDOMAIN ||
4482 eresult == DNS_R_NCACHENXRRSET);
4484 event->result = eresult;
4485 dns_db_attach(fctx->cache, adbp);
4486 dns_db_transfernode(fctx->cache, &node, anodep);
4487 clone_results(fctx);
4492 dns_db_detachnode(fctx->cache, &node);
4497 static inline isc_result_t
4498 cache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_stdtime_t now)
4500 isc_result_t result;
4501 dns_section_t section;
4504 FCTXTRACE("cache_message");
4506 fctx->attributes &= ~FCTX_ATTR_WANTCACHE;
4508 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4510 for (section = DNS_SECTION_ANSWER;
4511 section <= DNS_SECTION_ADDITIONAL;
4513 result = dns_message_firstname(fctx->rmessage, section);
4514 while (result == ISC_R_SUCCESS) {
4516 dns_message_currentname(fctx->rmessage, section,
4518 if ((name->attributes & DNS_NAMEATTR_CACHE) != 0) {
4519 result = cache_name(fctx, name, addrinfo, now);
4520 if (result != ISC_R_SUCCESS)
4523 result = dns_message_nextname(fctx->rmessage, section);
4525 if (result != ISC_R_NOMORE)
4528 if (result == ISC_R_NOMORE)
4529 result = ISC_R_SUCCESS;
4531 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4537 * Do what dns_ncache_add() does, and then compute an appropriate eresult.
4540 ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
4541 dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
4542 dns_rdataset_t *ardataset,
4543 isc_result_t *eresultp)
4545 isc_result_t result;
4546 dns_rdataset_t rdataset;
4548 if (ardataset == NULL) {
4549 dns_rdataset_init(&rdataset);
4550 ardataset = &rdataset;
4552 result = dns_ncache_add(message, cache, node, covers, now,
4554 if (result == DNS_R_UNCHANGED || result == ISC_R_SUCCESS) {
4556 * If the cache now contains a negative entry and we
4557 * care about whether it is DNS_R_NCACHENXDOMAIN or
4558 * DNS_R_NCACHENXRRSET then extract it.
4560 if (ardataset->type == 0) {
4562 * The cache data is a negative cache entry.
4564 if (NXDOMAIN(ardataset))
4565 *eresultp = DNS_R_NCACHENXDOMAIN;
4567 *eresultp = DNS_R_NCACHENXRRSET;
4570 * Either we don't care about the nature of the
4571 * cache rdataset (because no fetch is interested
4572 * in the outcome), or the cache rdataset is not
4573 * a negative cache entry. Whichever case it is,
4574 * we can return success.
4576 * XXXRTH There's a CNAME/DNAME problem here.
4578 *eresultp = ISC_R_SUCCESS;
4580 result = ISC_R_SUCCESS;
4582 if (ardataset == &rdataset && dns_rdataset_isassociated(ardataset))
4583 dns_rdataset_disassociate(ardataset);
4588 static inline isc_result_t
4589 ncache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
4590 dns_rdatatype_t covers, isc_stdtime_t now)
4592 isc_result_t result, eresult;
4594 dns_resolver_t *res;
4596 dns_dbnode_t *node, **anodep;
4597 dns_rdataset_t *ardataset;
4598 isc_boolean_t need_validation, secure_domain;
4600 dns_fetchevent_t *event;
4602 unsigned int valoptions = 0;
4604 FCTXTRACE("ncache_message");
4606 fctx->attributes &= ~FCTX_ATTR_WANTNCACHE;
4609 need_validation = ISC_FALSE;
4610 secure_domain = ISC_FALSE;
4611 eresult = ISC_R_SUCCESS;
4616 * XXXMPA remove when we follow cnames and adjust the setting
4617 * of FCTX_ATTR_WANTNCACHE in noanswer_response().
4619 INSIST(fctx->rmessage->counts[DNS_SECTION_ANSWER] == 0);
4622 * Is DNSSEC validation required for this name?
4624 if (fctx->res->view->enablevalidation) {
4625 result = dns_keytable_issecuredomain(res->view->secroots, name,
4627 if (result != ISC_R_SUCCESS)
4630 if (!secure_domain && res->view->dlv != NULL) {
4631 valoptions = DNS_VALIDATOR_DLV;
4632 secure_domain = ISC_TRUE;
4636 if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0)
4637 need_validation = ISC_FALSE;
4639 need_validation = secure_domain;
4641 if (secure_domain) {
4643 * Mark all rdatasets as pending.
4645 dns_rdataset_t *trdataset;
4648 result = dns_message_firstname(fctx->rmessage,
4649 DNS_SECTION_AUTHORITY);
4650 while (result == ISC_R_SUCCESS) {
4652 dns_message_currentname(fctx->rmessage,
4653 DNS_SECTION_AUTHORITY,
4655 for (trdataset = ISC_LIST_HEAD(tname->list);
4657 trdataset = ISC_LIST_NEXT(trdataset, link))
4658 trdataset->trust = dns_trust_pending_answer;
4659 result = dns_message_nextname(fctx->rmessage,
4660 DNS_SECTION_AUTHORITY);
4662 if (result != ISC_R_NOMORE)
4667 if (need_validation) {
4669 * Do negative response validation.
4671 result = valcreate(fctx, addrinfo, name, fctx->type,
4672 NULL, NULL, valoptions,
4673 res->buckets[fctx->bucketnum].task);
4675 * If validation is necessary, return now. Otherwise continue
4676 * to process the message, letting the validation complete
4677 * in its own good time.
4682 LOCK(&res->buckets[fctx->bucketnum].lock);
4688 if (!HAVE_ANSWER(fctx)) {
4689 event = ISC_LIST_HEAD(fctx->events);
4690 if (event != NULL) {
4692 aname = dns_fixedname_name(&event->foundname);
4693 result = dns_name_copy(name, aname, NULL);
4694 if (result != ISC_R_SUCCESS)
4696 anodep = &event->node;
4697 ardataset = event->rdataset;
4702 result = dns_db_findnode(fctx->cache, name, ISC_TRUE, &node);
4703 if (result != ISC_R_SUCCESS)
4707 * If we are asking for a SOA record set the cache time
4708 * to zero to facilitate locating the containing zone of
4711 ttl = fctx->res->view->maxncachettl;
4712 if (fctx->type == dns_rdatatype_soa &&
4713 covers == dns_rdatatype_any &&
4714 fctx->res->zero_no_soa_ttl)
4717 result = ncache_adderesult(fctx->rmessage, fctx->cache, node,
4718 covers, now, ttl, ardataset, &eresult);
4719 if (result != ISC_R_SUCCESS)
4722 if (!HAVE_ANSWER(fctx)) {
4723 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4724 if (event != NULL) {
4725 event->result = eresult;
4726 dns_db_attach(fctx->cache, adbp);
4727 dns_db_transfernode(fctx->cache, &node, anodep);
4728 clone_results(fctx);
4733 UNLOCK(&res->buckets[fctx->bucketnum].lock);
4736 dns_db_detachnode(fctx->cache, &node);
4742 mark_related(dns_name_t *name, dns_rdataset_t *rdataset,
4743 isc_boolean_t external, isc_boolean_t gluing)
4745 name->attributes |= DNS_NAMEATTR_CACHE;
4747 rdataset->trust = dns_trust_glue;
4749 * Glue with 0 TTL causes problems. We force the TTL to
4750 * 1 second to prevent this.
4752 if (rdataset->ttl == 0)
4755 rdataset->trust = dns_trust_additional;
4757 * Avoid infinite loops by only marking new rdatasets.
4759 if (!CACHE(rdataset)) {
4760 name->attributes |= DNS_NAMEATTR_CHASE;
4761 rdataset->attributes |= DNS_RDATASETATTR_CHASE;
4763 rdataset->attributes |= DNS_RDATASETATTR_CACHE;
4765 rdataset->attributes |= DNS_RDATASETATTR_EXTERNAL;
4769 check_related(void *arg, dns_name_t *addname, dns_rdatatype_t type) {
4770 fetchctx_t *fctx = arg;
4771 isc_result_t result;
4773 dns_rdataset_t *rdataset;
4774 isc_boolean_t external;
4775 dns_rdatatype_t rtype;
4776 isc_boolean_t gluing;
4778 REQUIRE(VALID_FCTX(fctx));
4786 result = dns_message_findname(fctx->rmessage, DNS_SECTION_ADDITIONAL,
4787 addname, dns_rdatatype_any, 0, &name,
4789 if (result == ISC_R_SUCCESS) {
4790 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
4791 if (type == dns_rdatatype_a) {
4792 for (rdataset = ISC_LIST_HEAD(name->list);
4794 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4795 if (rdataset->type == dns_rdatatype_rrsig)
4796 rtype = rdataset->covers;
4798 rtype = rdataset->type;
4799 if (rtype == dns_rdatatype_a ||
4800 rtype == dns_rdatatype_aaaa)
4801 mark_related(name, rdataset, external,
4805 result = dns_message_findtype(name, type, 0,
4807 if (result == ISC_R_SUCCESS) {
4808 mark_related(name, rdataset, external, gluing);
4810 * Do we have its SIG too?
4813 result = dns_message_findtype(name,
4814 dns_rdatatype_rrsig,
4816 if (result == ISC_R_SUCCESS)
4817 mark_related(name, rdataset, external,
4823 return (ISC_R_SUCCESS);
4827 chase_additional(fetchctx_t *fctx) {
4828 isc_boolean_t rescan;
4829 dns_section_t section = DNS_SECTION_ADDITIONAL;
4830 isc_result_t result;
4835 for (result = dns_message_firstname(fctx->rmessage, section);
4836 result == ISC_R_SUCCESS;
4837 result = dns_message_nextname(fctx->rmessage, section)) {
4838 dns_name_t *name = NULL;
4839 dns_rdataset_t *rdataset;
4840 dns_message_currentname(fctx->rmessage, DNS_SECTION_ADDITIONAL,
4842 if ((name->attributes & DNS_NAMEATTR_CHASE) == 0)
4844 name->attributes &= ~DNS_NAMEATTR_CHASE;
4845 for (rdataset = ISC_LIST_HEAD(name->list);
4847 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4848 if (CHASE(rdataset)) {
4849 rdataset->attributes &= ~DNS_RDATASETATTR_CHASE;
4850 (void)dns_rdataset_additionaldata(rdataset,
4861 static inline isc_result_t
4862 cname_target(dns_rdataset_t *rdataset, dns_name_t *tname) {
4863 isc_result_t result;
4864 dns_rdata_t rdata = DNS_RDATA_INIT;
4865 dns_rdata_cname_t cname;
4867 result = dns_rdataset_first(rdataset);
4868 if (result != ISC_R_SUCCESS)
4870 dns_rdataset_current(rdataset, &rdata);
4871 result = dns_rdata_tostruct(&rdata, &cname, NULL);
4872 if (result != ISC_R_SUCCESS)
4874 dns_name_init(tname, NULL);
4875 dns_name_clone(&cname.cname, tname);
4876 dns_rdata_freestruct(&cname);
4878 return (ISC_R_SUCCESS);
4881 static inline isc_result_t
4882 dname_target(dns_rdataset_t *rdataset, dns_name_t *qname, dns_name_t *oname,
4883 dns_fixedname_t *fixeddname)
4885 isc_result_t result;
4886 dns_rdata_t rdata = DNS_RDATA_INIT;
4887 unsigned int nlabels;
4889 dns_namereln_t namereln;
4890 dns_rdata_dname_t dname;
4891 dns_fixedname_t prefix;
4894 * Get the target name of the DNAME.
4897 result = dns_rdataset_first(rdataset);
4898 if (result != ISC_R_SUCCESS)
4900 dns_rdataset_current(rdataset, &rdata);
4901 result = dns_rdata_tostruct(&rdata, &dname, NULL);
4902 if (result != ISC_R_SUCCESS)
4906 * Get the prefix of qname.
4908 namereln = dns_name_fullcompare(qname, oname, &order, &nlabels);
4909 if (namereln != dns_namereln_subdomain) {
4910 dns_rdata_freestruct(&dname);
4911 return (DNS_R_FORMERR);
4913 dns_fixedname_init(&prefix);
4914 dns_name_split(qname, nlabels, dns_fixedname_name(&prefix), NULL);
4915 dns_fixedname_init(fixeddname);
4916 result = dns_name_concatenate(dns_fixedname_name(&prefix),
4918 dns_fixedname_name(fixeddname), NULL);
4919 dns_rdata_freestruct(&dname);
4924 * Handle a no-answer response (NXDOMAIN, NXRRSET, or referral).
4925 * If bind8_ns_resp is ISC_TRUE, this is a suspected BIND 8
4926 * response to an NS query that should be treated as a referral
4927 * even though the NS records occur in the answer section
4928 * rather than the authority section.
4931 noanswer_response(fetchctx_t *fctx, dns_name_t *oqname,
4932 isc_boolean_t bind8_ns_resp)
4934 isc_result_t result;
4935 dns_message_t *message;
4936 dns_name_t *name, *qname, *ns_name, *soa_name, *ds_name;
4937 dns_rdataset_t *rdataset, *ns_rdataset;
4938 isc_boolean_t aa, negative_response;
4939 dns_rdatatype_t type;
4940 dns_section_t section =
4941 bind8_ns_resp ? DNS_SECTION_ANSWER : DNS_SECTION_AUTHORITY;
4943 FCTXTRACE("noanswer_response");
4945 message = fctx->rmessage;
4950 if (oqname == NULL) {
4952 * We have a normal, non-chained negative response or
4955 if ((message->flags & DNS_MESSAGEFLAG_AA) != 0)
4959 qname = &fctx->name;
4962 * We're being invoked by answer_response() after it has
4963 * followed a CNAME/DNAME chain.
4968 * If the current qname is not a subdomain of the query
4969 * domain, there's no point in looking at the authority
4970 * section without doing DNSSEC validation.
4972 * Until we do that validation, we'll just return success
4975 if (!dns_name_issubdomain(qname, &fctx->domain))
4976 return (ISC_R_SUCCESS);
4980 * We have to figure out if this is a negative response, or a
4985 * Sometimes we can tell if its a negative response by looking at
4986 * the message header.
4988 negative_response = ISC_FALSE;
4989 if (message->rcode == dns_rcode_nxdomain ||
4990 (message->counts[DNS_SECTION_ANSWER] == 0 &&
4991 message->counts[DNS_SECTION_AUTHORITY] == 0))
4992 negative_response = ISC_TRUE;
4995 * Process the authority section.
5001 result = dns_message_firstname(message, section);
5002 while (result == ISC_R_SUCCESS) {
5004 dns_message_currentname(message, section, &name);
5005 if (dns_name_issubdomain(name, &fctx->domain)) {
5007 * Look for NS/SOA RRsets first.
5009 for (rdataset = ISC_LIST_HEAD(name->list);
5011 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5012 type = rdataset->type;
5013 if (type == dns_rdatatype_rrsig)
5014 type = rdataset->covers;
5015 if (((type == dns_rdatatype_ns ||
5016 type == dns_rdatatype_soa) &&
5017 !dns_name_issubdomain(qname, name)))
5018 return (DNS_R_FORMERR);
5019 if (type == dns_rdatatype_ns) {
5023 * Only one set of NS RRs is allowed.
5025 if (rdataset->type ==
5027 if (ns_name != NULL &&
5029 return (DNS_R_FORMERR);
5031 ns_rdataset = rdataset;
5035 rdataset->attributes |=
5036 DNS_RDATASETATTR_CACHE;
5037 rdataset->trust = dns_trust_glue;
5039 if (type == dns_rdatatype_soa) {
5041 * SOA, or RRSIG SOA.
5043 * Only one SOA is allowed.
5045 if (rdataset->type ==
5046 dns_rdatatype_soa) {
5047 if (soa_name != NULL &&
5049 return (DNS_R_FORMERR);
5053 DNS_NAMEATTR_NCACHE;
5054 rdataset->attributes |=
5055 DNS_RDATASETATTR_NCACHE;
5058 dns_trust_authauthority;
5061 dns_trust_additional;
5065 result = dns_message_nextname(message, section);
5066 if (result == ISC_R_NOMORE)
5068 else if (result != ISC_R_SUCCESS)
5073 * A negative response has a SOA record (Type 2)
5074 * and a optional NS RRset (Type 1) or it has neither
5075 * a SOA or a NS RRset (Type 3, handled above) or
5076 * rcode is NXDOMAIN (handled above) in which case
5077 * the NS RRset is allowed (Type 4).
5079 if (soa_name != NULL)
5080 negative_response = ISC_TRUE;
5082 result = dns_message_firstname(message, section);
5083 while (result == ISC_R_SUCCESS) {
5085 dns_message_currentname(message, section, &name);
5086 if (dns_name_issubdomain(name, &fctx->domain)) {
5087 for (rdataset = ISC_LIST_HEAD(name->list);
5089 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5090 type = rdataset->type;
5091 if (type == dns_rdatatype_rrsig)
5092 type = rdataset->covers;
5093 if (type == dns_rdatatype_nsec) {
5095 * NSEC or RRSIG NSEC.
5097 if (negative_response) {
5099 DNS_NAMEATTR_NCACHE;
5100 rdataset->attributes |=
5101 DNS_RDATASETATTR_NCACHE;
5105 rdataset->attributes |=
5106 DNS_RDATASETATTR_CACHE;
5110 dns_trust_authauthority;
5113 dns_trust_additional;
5115 * No additional data needs to be
5118 } else if (type == dns_rdatatype_ds) {
5122 * These should only be here if
5123 * this is a referral, and there
5124 * should only be one DS.
5126 if (ns_name == NULL)
5127 return (DNS_R_FORMERR);
5128 if (rdataset->type ==
5130 if (ds_name != NULL &&
5132 return (DNS_R_FORMERR);
5137 rdataset->attributes |=
5138 DNS_RDATASETATTR_CACHE;
5141 dns_trust_authauthority;
5144 dns_trust_additional;
5148 result = dns_message_nextname(message, section);
5149 if (result == ISC_R_NOMORE)
5151 else if (result != ISC_R_SUCCESS)
5156 * Trigger lookups for DNS nameservers.
5158 if (negative_response && message->rcode == dns_rcode_noerror &&
5159 fctx->type == dns_rdatatype_ds && soa_name != NULL &&
5160 dns_name_equal(soa_name, qname) &&
5161 !dns_name_equal(qname, dns_rootname))
5162 return (DNS_R_CHASEDSSERVERS);
5165 * Did we find anything?
5167 if (!negative_response && ns_name == NULL) {
5171 if (oqname != NULL) {
5173 * We've already got a partial CNAME/DNAME chain,
5174 * and haven't found else anything useful here, but
5175 * no error has occurred since we have an answer.
5177 return (ISC_R_SUCCESS);
5180 * The responder is insane.
5182 return (DNS_R_FORMERR);
5187 * If we found both NS and SOA, they should be the same name.
5189 if (ns_name != NULL && soa_name != NULL && ns_name != soa_name)
5190 return (DNS_R_FORMERR);
5193 * Do we have a referral? (We only want to follow a referral if
5194 * we're not following a chain.)
5196 if (!negative_response && ns_name != NULL && oqname == NULL) {
5198 * We already know ns_name is a subdomain of fctx->domain.
5199 * If ns_name is equal to fctx->domain, we're not making
5200 * progress. We return DNS_R_FORMERR so that we'll keep
5201 * trying other servers.
5203 if (dns_name_equal(ns_name, &fctx->domain))
5204 return (DNS_R_FORMERR);
5207 * If the referral name is not a parent of the query
5208 * name, consider the responder insane.
5210 if (! dns_name_issubdomain(&fctx->name, ns_name)) {
5211 FCTXTRACE("referral to non-parent");
5212 return (DNS_R_FORMERR);
5216 * Mark any additional data related to this rdataset.
5217 * It's important that we do this before we change the
5220 INSIST(ns_rdataset != NULL);
5221 fctx->attributes |= FCTX_ATTR_GLUING;
5222 (void)dns_rdataset_additionaldata(ns_rdataset, check_related,
5224 fctx->attributes &= ~FCTX_ATTR_GLUING;
5226 * NS rdatasets with 0 TTL cause problems.
5227 * dns_view_findzonecut() will not find them when we
5228 * try to follow the referral, and we'll SERVFAIL
5229 * because the best nameservers are now above QDOMAIN.
5230 * We force the TTL to 1 second to prevent this.
5232 if (ns_rdataset->ttl == 0)
5233 ns_rdataset->ttl = 1;
5235 * Set the current query domain to the referral name.
5237 * XXXRTH We should check if we're in forward-only mode, and
5238 * if so we should bail out.
5240 INSIST(dns_name_countlabels(&fctx->domain) > 0);
5241 dns_name_free(&fctx->domain,
5242 fctx->res->buckets[fctx->bucketnum].mctx);
5243 if (dns_rdataset_isassociated(&fctx->nameservers))
5244 dns_rdataset_disassociate(&fctx->nameservers);
5245 dns_name_init(&fctx->domain, NULL);
5246 result = dns_name_dup(ns_name,
5247 fctx->res->buckets[fctx->bucketnum].mctx,
5249 if (result != ISC_R_SUCCESS)
5251 fctx->attributes |= FCTX_ATTR_WANTCACHE;
5252 return (DNS_R_DELEGATION);
5256 * Since we're not doing a referral, we don't want to cache any
5257 * NS RRs we may have found.
5259 if (ns_name != NULL)
5260 ns_name->attributes &= ~DNS_NAMEATTR_CACHE;
5262 if (negative_response && oqname == NULL)
5263 fctx->attributes |= FCTX_ATTR_WANTNCACHE;
5265 return (ISC_R_SUCCESS);
5269 answer_response(fetchctx_t *fctx) {
5270 isc_result_t result;
5271 dns_message_t *message;
5272 dns_name_t *name, *qname, tname;
5273 dns_rdataset_t *rdataset;
5274 isc_boolean_t done, external, chaining, aa, found, want_chaining;
5275 isc_boolean_t have_answer, found_cname, found_type, wanted_chaining;
5277 dns_rdatatype_t type;
5278 dns_fixedname_t dname, fqname;
5280 FCTXTRACE("answer_response");
5282 message = fctx->rmessage;
5285 * Examine the answer section, marking those rdatasets which are
5286 * part of the answer and should be cached.
5290 found_cname = ISC_FALSE;
5291 found_type = ISC_FALSE;
5292 chaining = ISC_FALSE;
5293 have_answer = ISC_FALSE;
5294 want_chaining = ISC_FALSE;
5295 if ((message->flags & DNS_MESSAGEFLAG_AA) != 0)
5299 qname = &fctx->name;
5301 result = dns_message_firstname(message, DNS_SECTION_ANSWER);
5302 while (!done && result == ISC_R_SUCCESS) {
5304 dns_message_currentname(message, DNS_SECTION_ANSWER, &name);
5305 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
5306 if (dns_name_equal(name, qname)) {
5307 wanted_chaining = ISC_FALSE;
5308 for (rdataset = ISC_LIST_HEAD(name->list);
5310 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5312 want_chaining = ISC_FALSE;
5314 if (rdataset->type == type && !found_cname) {
5316 * We've found an ordinary answer.
5319 found_type = ISC_TRUE;
5321 aflag = DNS_RDATASETATTR_ANSWER;
5322 } else if (type == dns_rdatatype_any) {
5324 * We've found an answer matching
5325 * an ANY query. There may be
5329 aflag = DNS_RDATASETATTR_ANSWER;
5330 } else if (rdataset->type == dns_rdatatype_rrsig
5331 && rdataset->covers == type
5334 * We've found a signature that
5335 * covers the type we're looking for.
5338 found_type = ISC_TRUE;
5339 aflag = DNS_RDATASETATTR_ANSWERSIG;
5340 } else if (rdataset->type ==
5344 * We're looking for something else,
5345 * but we found a CNAME.
5347 * Getting a CNAME response for some
5348 * query types is an error.
5350 if (type == dns_rdatatype_rrsig ||
5351 type == dns_rdatatype_dnskey ||
5352 type == dns_rdatatype_nsec)
5353 return (DNS_R_FORMERR);
5355 found_cname = ISC_TRUE;
5356 want_chaining = ISC_TRUE;
5357 aflag = DNS_RDATASETATTR_ANSWER;
5358 result = cname_target(rdataset,
5360 if (result != ISC_R_SUCCESS)
5362 } else if (rdataset->type == dns_rdatatype_rrsig
5363 && rdataset->covers ==
5367 * We're looking for something else,
5368 * but we found a SIG CNAME.
5371 found_cname = ISC_TRUE;
5372 aflag = DNS_RDATASETATTR_ANSWERSIG;
5377 * We've found an answer to our
5382 rdataset->attributes |=
5383 DNS_RDATASETATTR_CACHE;
5384 rdataset->trust = dns_trust_answer;
5387 * This data is "the" answer
5388 * to our question only if
5389 * we're not chaining (i.e.
5390 * if we haven't followed
5391 * a CNAME or DNAME).
5395 DNS_RDATASETATTR_ANSWER)
5396 have_answer = ISC_TRUE;
5398 DNS_NAMEATTR_ANSWER;
5399 rdataset->attributes |= aflag;
5402 dns_trust_authanswer;
5403 } else if (external) {
5405 * This data is outside of
5406 * our query domain, and
5407 * may only be cached if it
5408 * comes from a secure zone
5411 rdataset->attributes |=
5412 DNS_RDATASETATTR_EXTERNAL;
5416 * Mark any additional data related
5419 (void)dns_rdataset_additionaldata(
5427 if (want_chaining) {
5428 wanted_chaining = ISC_TRUE;
5430 DNS_NAMEATTR_CHAINING;
5431 rdataset->attributes |=
5432 DNS_RDATASETATTR_CHAINING;
5437 * We could add an "else" clause here and
5438 * log that we're ignoring this rdataset.
5442 * If wanted_chaining is true, we've done
5443 * some chaining as the result of processing
5444 * this node, and thus we need to set
5447 * We don't set chaining inside of the
5448 * rdataset loop because doing that would
5449 * cause us to ignore the signatures of
5452 if (wanted_chaining)
5453 chaining = ISC_TRUE;
5456 * Look for a DNAME (or its SIG). Anything else is
5459 wanted_chaining = ISC_FALSE;
5460 for (rdataset = ISC_LIST_HEAD(name->list);
5462 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5463 isc_boolean_t found_dname = ISC_FALSE;
5466 if (rdataset->type == dns_rdatatype_dname) {
5468 * We're looking for something else,
5469 * but we found a DNAME.
5471 * If we're not chaining, then the
5472 * DNAME should not be external.
5474 if (!chaining && external)
5475 return (DNS_R_FORMERR);
5477 want_chaining = ISC_TRUE;
5478 aflag = DNS_RDATASETATTR_ANSWER;
5479 result = dname_target(rdataset,
5482 if (result == ISC_R_NOSPACE) {
5484 * We can't construct the
5485 * DNAME target. Do not
5488 want_chaining = ISC_FALSE;
5489 } else if (result != ISC_R_SUCCESS)
5492 found_dname = ISC_TRUE;
5493 } else if (rdataset->type == dns_rdatatype_rrsig
5494 && rdataset->covers ==
5495 dns_rdatatype_dname) {
5497 * We've found a signature that
5501 aflag = DNS_RDATASETATTR_ANSWERSIG;
5506 * We've found an answer to our
5511 rdataset->attributes |=
5512 DNS_RDATASETATTR_CACHE;
5513 rdataset->trust = dns_trust_answer;
5516 * This data is "the" answer
5517 * to our question only if
5518 * we're not chaining.
5522 DNS_RDATASETATTR_ANSWER)
5523 have_answer = ISC_TRUE;
5525 DNS_NAMEATTR_ANSWER;
5526 rdataset->attributes |= aflag;
5529 dns_trust_authanswer;
5530 } else if (external) {
5531 rdataset->attributes |=
5532 DNS_RDATASETATTR_EXTERNAL;
5540 * Copy the dname into the
5543 * Although we check for
5544 * failure of the copy
5545 * operation, in practice it
5546 * should never fail since
5547 * we already know that the
5548 * result fits in a fixedname.
5550 dns_fixedname_init(&fqname);
5551 result = dns_name_copy(
5552 dns_fixedname_name(&dname),
5553 dns_fixedname_name(&fqname),
5555 if (result != ISC_R_SUCCESS)
5557 wanted_chaining = ISC_TRUE;
5559 DNS_NAMEATTR_CHAINING;
5560 rdataset->attributes |=
5561 DNS_RDATASETATTR_CHAINING;
5562 qname = dns_fixedname_name(
5567 if (wanted_chaining)
5568 chaining = ISC_TRUE;
5570 result = dns_message_nextname(message, DNS_SECTION_ANSWER);
5572 if (result == ISC_R_NOMORE)
5573 result = ISC_R_SUCCESS;
5574 if (result != ISC_R_SUCCESS)
5578 * We should have found an answer.
5581 return (DNS_R_FORMERR);
5584 * This response is now potentially cacheable.
5586 fctx->attributes |= FCTX_ATTR_WANTCACHE;
5589 * Did chaining end before we got the final answer?
5593 * Yes. This may be a negative reply, so hand off
5594 * authority section processing to the noanswer code.
5595 * If it isn't a noanswer response, no harm will be
5598 return (noanswer_response(fctx, qname, ISC_FALSE));
5602 * We didn't end with an incomplete chain, so the rcode should be
5605 if (message->rcode != dns_rcode_noerror)
5606 return (DNS_R_FORMERR);
5609 * Examine the authority section (if there is one).
5611 * We expect there to be only one owner name for all the rdatasets
5612 * in this section, and we expect that it is not external.
5615 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
5616 while (!done && result == ISC_R_SUCCESS) {
5618 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
5619 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
5622 * We expect to find NS or SIG NS rdatasets, and
5625 for (rdataset = ISC_LIST_HEAD(name->list);
5627 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5628 if (rdataset->type == dns_rdatatype_ns ||
5629 (rdataset->type == dns_rdatatype_rrsig &&
5630 rdataset->covers == dns_rdatatype_ns)) {
5633 rdataset->attributes |=
5634 DNS_RDATASETATTR_CACHE;
5635 if (aa && !chaining)
5637 dns_trust_authauthority;
5640 dns_trust_additional;
5643 * Mark any additional data related
5646 (void)dns_rdataset_additionaldata(
5654 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
5656 if (result == ISC_R_NOMORE)
5657 result = ISC_R_SUCCESS;
5663 resume_dslookup(isc_task_t *task, isc_event_t *event) {
5664 dns_fetchevent_t *fevent;
5665 dns_resolver_t *res;
5667 isc_result_t result;
5668 isc_boolean_t bucket_empty = ISC_FALSE;
5669 isc_boolean_t locked = ISC_FALSE;
5670 unsigned int bucketnum;
5671 dns_rdataset_t nameservers;
5672 dns_fixedname_t fixed;
5675 REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
5676 fevent = (dns_fetchevent_t *)event;
5677 fctx = event->ev_arg;
5678 REQUIRE(VALID_FCTX(fctx));
5682 FCTXTRACE("resume_dslookup");
5684 if (fevent->node != NULL)
5685 dns_db_detachnode(fevent->db, &fevent->node);
5686 if (fevent->db != NULL)
5687 dns_db_detach(&fevent->db);
5689 dns_rdataset_init(&nameservers);
5691 bucketnum = fctx->bucketnum;
5692 if (fevent->result == ISC_R_CANCELED) {
5693 dns_resolver_destroyfetch(&fctx->nsfetch);
5694 fctx_done(fctx, ISC_R_CANCELED, __LINE__);
5695 } else if (fevent->result == ISC_R_SUCCESS) {
5697 FCTXTRACE("resuming DS lookup");
5699 dns_resolver_destroyfetch(&fctx->nsfetch);
5700 if (dns_rdataset_isassociated(&fctx->nameservers))
5701 dns_rdataset_disassociate(&fctx->nameservers);
5702 dns_rdataset_clone(fevent->rdataset, &fctx->nameservers);
5703 dns_name_free(&fctx->domain,
5704 fctx->res->buckets[bucketnum].mctx);
5705 dns_name_init(&fctx->domain, NULL);
5706 result = dns_name_dup(&fctx->nsname,
5707 fctx->res->buckets[bucketnum].mctx,
5709 if (result != ISC_R_SUCCESS) {
5710 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
5716 fctx_try(fctx, ISC_TRUE);
5719 dns_rdataset_t *nsrdataset = NULL;
5722 * Retrieve state from fctx->nsfetch before we destroy it.
5724 dns_fixedname_init(&fixed);
5725 domain = dns_fixedname_name(&fixed);
5726 dns_name_copy(&fctx->nsfetch->private->domain, domain, NULL);
5727 if (dns_name_equal(&fctx->nsname, domain)) {
5728 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
5729 dns_resolver_destroyfetch(&fctx->nsfetch);
5732 if (dns_rdataset_isassociated(
5733 &fctx->nsfetch->private->nameservers)) {
5735 &fctx->nsfetch->private->nameservers,
5737 nsrdataset = &nameservers;
5740 dns_resolver_destroyfetch(&fctx->nsfetch);
5741 n = dns_name_countlabels(&fctx->nsname);
5742 dns_name_getlabelsequence(&fctx->nsname, 1, n - 1,
5745 if (dns_rdataset_isassociated(fevent->rdataset))
5746 dns_rdataset_disassociate(fevent->rdataset);
5747 FCTXTRACE("continuing to look for parent's NS records");
5748 result = dns_resolver_createfetch(fctx->res, &fctx->nsname,
5749 dns_rdatatype_ns, domain,
5750 nsrdataset, NULL, 0, task,
5751 resume_dslookup, fctx,
5752 &fctx->nsrrset, NULL,
5754 if (result != ISC_R_SUCCESS)
5755 fctx_done(fctx, result, __LINE__);
5757 LOCK(&res->buckets[bucketnum].lock);
5764 if (dns_rdataset_isassociated(&nameservers))
5765 dns_rdataset_disassociate(&nameservers);
5766 if (dns_rdataset_isassociated(fevent->rdataset))
5767 dns_rdataset_disassociate(fevent->rdataset);
5768 INSIST(fevent->sigrdataset == NULL);
5769 isc_event_free(&event);
5771 LOCK(&res->buckets[bucketnum].lock);
5773 if (fctx->references == 0)
5774 bucket_empty = fctx_destroy(fctx);
5775 UNLOCK(&res->buckets[bucketnum].lock);
5781 checknamessection(dns_message_t *message, dns_section_t section) {
5782 isc_result_t result;
5784 dns_rdata_t rdata = DNS_RDATA_INIT;
5785 dns_rdataset_t *rdataset;
5787 for (result = dns_message_firstname(message, section);
5788 result == ISC_R_SUCCESS;
5789 result = dns_message_nextname(message, section))
5792 dns_message_currentname(message, section, &name);
5793 for (rdataset = ISC_LIST_HEAD(name->list);
5795 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5796 for (result = dns_rdataset_first(rdataset);
5797 result == ISC_R_SUCCESS;
5798 result = dns_rdataset_next(rdataset)) {
5799 dns_rdataset_current(rdataset, &rdata);
5800 if (!dns_rdata_checkowner(name, rdata.rdclass,
5803 !dns_rdata_checknames(&rdata, name, NULL))
5805 rdataset->attributes |=
5806 DNS_RDATASETATTR_CHECKNAMES;
5808 dns_rdata_reset(&rdata);
5815 checknames(dns_message_t *message) {
5817 checknamessection(message, DNS_SECTION_ANSWER);
5818 checknamessection(message, DNS_SECTION_AUTHORITY);
5819 checknamessection(message, DNS_SECTION_ADDITIONAL);
5823 * Log server NSID at log level 'level'
5826 log_nsid(dns_rdataset_t *opt, resquery_t *query, int level, isc_mem_t *mctx)
5828 static const char hex[17] = "0123456789abcdef";
5829 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
5830 isc_uint16_t optcode, nsid_len, buflen, i;
5831 isc_result_t result;
5832 isc_buffer_t nsidbuf;
5834 unsigned char *p, *buf, *nsid;
5836 /* Extract rdata from OPT rdataset */
5837 result = dns_rdataset_first(opt);
5838 if (result != ISC_R_SUCCESS)
5839 return (ISC_R_FAILURE);
5841 dns_rdata_init(&rdata);
5842 dns_rdataset_current(opt, &rdata);
5843 if (rdata.length < 4)
5844 return (ISC_R_FAILURE);
5846 /* Check for NSID */
5847 isc_buffer_init(&nsidbuf, rdata.data, rdata.length);
5848 isc_buffer_add(&nsidbuf, rdata.length);
5849 optcode = isc_buffer_getuint16(&nsidbuf);
5850 nsid_len = isc_buffer_getuint16(&nsidbuf);
5851 if (optcode != DNS_OPT_NSID || nsid_len == 0)
5852 return (ISC_R_FAILURE);
5854 /* Allocate buffer for storing hex version of the NSID */
5855 buflen = nsid_len * 2 + 1;
5856 buf = isc_mem_get(mctx, buflen);
5858 return (ISC_R_NOSPACE);
5860 /* Convert to hex */
5862 nsid = rdata.data + 4;
5863 for (i = 0; i < nsid_len; i++) {
5864 *p++ = hex[(nsid[0] >> 4) & 0xf];
5865 *p++ = hex[nsid[0] & 0xf];
5870 isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf,
5872 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
5873 DNS_LOGMODULE_RESOLVER, level,
5874 "received NSID '%s' from %s", buf, addrbuf);
5877 isc_mem_put(mctx, buf, buflen);
5878 return (ISC_R_SUCCESS);
5882 log_packet(dns_message_t *message, int level, isc_mem_t *mctx) {
5883 isc_buffer_t buffer;
5886 isc_result_t result;
5888 if (! isc_log_wouldlog(dns_lctx, level))
5892 * Note that these are multiline debug messages. We want a newline
5893 * to appear in the log after each message.
5897 buf = isc_mem_get(mctx, len);
5900 isc_buffer_init(&buffer, buf, len);
5901 result = dns_message_totext(message, &dns_master_style_debug,
5903 if (result == ISC_R_NOSPACE) {
5904 isc_mem_put(mctx, buf, len);
5906 } else if (result == ISC_R_SUCCESS)
5907 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
5908 DNS_LOGMODULE_RESOLVER, level,
5909 "received packet:\n%.*s",
5910 (int)isc_buffer_usedlength(&buffer),
5912 } while (result == ISC_R_NOSPACE);
5915 isc_mem_put(mctx, buf, len);
5919 resquery_response(isc_task_t *task, isc_event_t *event) {
5920 isc_result_t result = ISC_R_SUCCESS;
5921 resquery_t *query = event->ev_arg;
5922 dns_dispatchevent_t *devent = (dns_dispatchevent_t *)event;
5923 isc_boolean_t keep_trying, get_nameservers, resend;
5924 isc_boolean_t truncated;
5925 dns_message_t *message;
5926 dns_rdataset_t *opt;
5929 dns_fixedname_t foundname;
5931 isc_time_t tnow, *finish;
5932 dns_adbaddrinfo_t *addrinfo;
5933 unsigned int options;
5934 unsigned int findoptions;
5935 isc_result_t broken_server;
5936 badnstype_t broken_type = badns_response;
5938 REQUIRE(VALID_QUERY(query));
5940 options = query->options;
5941 REQUIRE(VALID_FCTX(fctx));
5942 REQUIRE(event->ev_type == DNS_EVENT_DISPATCH);
5946 if (isc_sockaddr_pf(&query->addrinfo->sockaddr) == PF_INET)
5947 inc_stats(fctx->res, dns_resstatscounter_responsev4);
5949 inc_stats(fctx->res, dns_resstatscounter_responsev6);
5951 (void)isc_timer_touch(fctx->timer);
5953 keep_trying = ISC_FALSE;
5954 broken_server = ISC_R_SUCCESS;
5955 get_nameservers = ISC_FALSE;
5957 truncated = ISC_FALSE;
5960 if (fctx->res->exiting) {
5961 result = ISC_R_SHUTTINGDOWN;
5966 fctx->timeout = ISC_FALSE;
5969 * XXXRTH We should really get the current time just once. We
5970 * need a routine to convert from an isc_time_t to an
5975 isc_stdtime_get(&now);
5978 * Did the dispatcher have a problem?
5980 if (devent->result != ISC_R_SUCCESS) {
5981 if (devent->result == ISC_R_EOF &&
5982 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
5984 * The problem might be that they
5985 * don't understand EDNS0. Turn it
5986 * off and try again.
5988 options |= DNS_FETCHOPT_NOEDNS0;
5991 * Remember that they don't like EDNS0.
5993 dns_adb_changeflags(fctx->adb,
5995 DNS_FETCHOPT_NOEDNS0,
5996 DNS_FETCHOPT_NOEDNS0);
5999 * There's no hope for this query.
6001 keep_trying = ISC_TRUE;
6004 * If this is a network error on an exclusive query
6005 * socket, mark the server as bad so that we won't try
6006 * it for this fetch again.
6008 if (query->exclusivesocket &&
6009 (devent->result == ISC_R_HOSTUNREACH ||
6010 devent->result == ISC_R_NETUNREACH ||
6011 devent->result == ISC_R_CONNREFUSED ||
6012 devent->result == ISC_R_CANCELED)) {
6013 broken_server = devent->result;
6014 broken_type = badns_unreachable;
6020 message = fctx->rmessage;
6022 if (query->tsig != NULL) {
6023 result = dns_message_setquerytsig(message, query->tsig);
6024 if (result != ISC_R_SUCCESS)
6028 if (query->tsigkey) {
6029 result = dns_message_settsigkey(message, query->tsigkey);
6030 if (result != ISC_R_SUCCESS)
6034 result = dns_message_parse(message, &devent->buffer, 0);
6035 if (result != ISC_R_SUCCESS) {
6037 case ISC_R_UNEXPECTEDEND:
6038 if (!message->question_ok ||
6039 (message->flags & DNS_MESSAGEFLAG_TC) == 0 ||
6040 (options & DNS_FETCHOPT_TCP) != 0) {
6042 * Either the message ended prematurely,
6043 * and/or wasn't marked as being truncated,
6044 * and/or this is a response to a query we
6045 * sent over TCP. In all of these cases,
6046 * something is wrong with the remote
6047 * server and we don't want to retry using
6050 if ((query->options & DNS_FETCHOPT_NOEDNS0)
6053 * The problem might be that they
6054 * don't understand EDNS0. Turn it
6055 * off and try again.
6057 options |= DNS_FETCHOPT_NOEDNS0;
6060 * Remember that they don't like EDNS0.
6062 dns_adb_changeflags(
6065 DNS_FETCHOPT_NOEDNS0,
6066 DNS_FETCHOPT_NOEDNS0);
6067 inc_stats(fctx->res,
6068 dns_resstatscounter_edns0fail);
6070 broken_server = result;
6071 keep_trying = ISC_TRUE;
6076 * We defer retrying via TCP for a bit so we can
6077 * check out this message further.
6079 truncated = ISC_TRUE;
6082 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
6084 * The problem might be that they
6085 * don't understand EDNS0. Turn it
6086 * off and try again.
6088 options |= DNS_FETCHOPT_NOEDNS0;
6091 * Remember that they don't like EDNS0.
6093 dns_adb_changeflags(fctx->adb,
6095 DNS_FETCHOPT_NOEDNS0,
6096 DNS_FETCHOPT_NOEDNS0);
6097 inc_stats(fctx->res,
6098 dns_resstatscounter_edns0fail);
6100 broken_server = DNS_R_UNEXPECTEDRCODE;
6101 keep_trying = ISC_TRUE;
6106 * Something bad has happened.
6114 * Log the incoming packet.
6116 log_packet(message, ISC_LOG_DEBUG(10), fctx->res->mctx);
6119 * Did we request NSID? If so, and if the response contains
6120 * NSID data, log it at INFO level.
6122 opt = dns_message_getopt(message);
6123 if (opt != NULL && (query->options & DNS_FETCHOPT_WANTNSID) != 0)
6124 log_nsid(opt, query, ISC_LOG_INFO, fctx->res->mctx);
6127 * If the message is signed, check the signature. If not, this
6128 * returns success anyway.
6130 result = dns_message_checksig(message, fctx->res->view);
6131 if (result != ISC_R_SUCCESS)
6135 * The dispatcher should ensure we only get responses with QR set.
6137 INSIST((message->flags & DNS_MESSAGEFLAG_QR) != 0);
6139 * INSIST() that the message comes from the place we sent it to,
6140 * since the dispatch code should ensure this.
6142 * INSIST() that the message id is correct (this should also be
6143 * ensured by the dispatch code).
6148 * Deal with truncated responses by retrying using TCP.
6150 if ((message->flags & DNS_MESSAGEFLAG_TC) != 0)
6151 truncated = ISC_TRUE;
6154 inc_stats(fctx->res, dns_resstatscounter_truncated);
6155 if ((options & DNS_FETCHOPT_TCP) != 0) {
6156 broken_server = DNS_R_TRUNCATEDTCP;
6157 keep_trying = ISC_TRUE;
6159 options |= DNS_FETCHOPT_TCP;
6166 * Is it a query response?
6168 if (message->opcode != dns_opcode_query) {
6170 broken_server = DNS_R_UNEXPECTEDOPCODE;
6171 keep_trying = ISC_TRUE;
6176 * Update statistics about erroneous responses.
6178 if (message->rcode != dns_rcode_noerror) {
6179 switch (message->rcode) {
6180 case dns_rcode_nxdomain:
6181 inc_stats(fctx->res, dns_resstatscounter_nxdomain);
6183 case dns_rcode_servfail:
6184 inc_stats(fctx->res, dns_resstatscounter_servfail);
6186 case dns_rcode_formerr:
6187 inc_stats(fctx->res, dns_resstatscounter_formerr);
6190 inc_stats(fctx->res, dns_resstatscounter_othererror);
6196 * Is the remote server broken, or does it dislike us?
6198 if (message->rcode != dns_rcode_noerror &&
6199 message->rcode != dns_rcode_nxdomain) {
6200 if (((message->rcode == dns_rcode_formerr ||
6201 message->rcode == dns_rcode_notimp) ||
6202 (message->rcode == dns_rcode_servfail &&
6203 dns_message_getopt(message) == NULL)) &&
6204 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
6206 * It's very likely they don't like EDNS0.
6207 * If the response code is SERVFAIL, also check if the
6208 * response contains an OPT RR and don't cache the
6209 * failure since it can be returned for various other
6212 * XXXRTH We should check if the question
6213 * we're asking requires EDNS0, and
6214 * if so, we should bail out.
6216 options |= DNS_FETCHOPT_NOEDNS0;
6219 * Remember that they don't like EDNS0.
6221 if (message->rcode != dns_rcode_servfail)
6222 dns_adb_changeflags(fctx->adb, query->addrinfo,
6223 DNS_FETCHOPT_NOEDNS0,
6224 DNS_FETCHOPT_NOEDNS0);
6225 inc_stats(fctx->res, dns_resstatscounter_edns0fail);
6226 } else if (message->rcode == dns_rcode_formerr) {
6227 if (ISFORWARDER(query->addrinfo)) {
6229 * This forwarder doesn't understand us,
6230 * but other forwarders might. Keep trying.
6232 broken_server = DNS_R_REMOTEFORMERR;
6233 keep_trying = ISC_TRUE;
6236 * The server doesn't understand us. Since
6237 * all servers for a zone need similar
6238 * capabilities, we assume that we will get
6239 * FORMERR from all servers, and thus we
6240 * cannot make any more progress with this
6243 result = DNS_R_FORMERR;
6245 } else if (message->rcode == dns_rcode_yxdomain) {
6247 * DNAME mapping failed because the new name
6248 * was too long. There's no chance of success
6251 result = DNS_R_YXDOMAIN;
6252 } else if (message->rcode == dns_rcode_badvers) {
6253 unsigned int flags, mask;
6254 unsigned int version;
6257 version = (opt->ttl >> 16) & 0xff;
6258 flags = (version << DNS_FETCHOPT_EDNSVERSIONSHIFT) |
6259 DNS_FETCHOPT_EDNSVERSIONSET;
6260 mask = DNS_FETCHOPT_EDNSVERSIONMASK |
6261 DNS_FETCHOPT_EDNSVERSIONSET;
6264 dns_adb_changeflags(fctx->adb, query->addrinfo,
6268 broken_server = DNS_R_BADVERS;
6269 keep_trying = ISC_TRUE;
6276 broken_server = DNS_R_UNEXPECTEDRCODE;
6277 INSIST(broken_server != ISC_R_SUCCESS);
6278 keep_trying = ISC_TRUE;
6284 * Is the question the same as the one we asked?
6286 result = same_question(fctx);
6287 if (result != ISC_R_SUCCESS) {
6289 if (result == DNS_R_FORMERR)
6290 keep_trying = ISC_TRUE;
6295 * Is the server lame?
6297 if (fctx->res->lame_ttl != 0 && !ISFORWARDER(query->addrinfo) &&
6299 inc_stats(fctx->res, dns_resstatscounter_lame);
6300 log_lame(fctx, query->addrinfo);
6301 result = dns_adb_marklame(fctx->adb, query->addrinfo,
6302 &fctx->name, fctx->type,
6303 now + fctx->res->lame_ttl);
6304 if (result != ISC_R_SUCCESS)
6305 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
6306 DNS_LOGMODULE_RESOLVER, ISC_LOG_ERROR,
6307 "could not mark server as lame: %s",
6308 isc_result_totext(result));
6309 broken_server = DNS_R_LAME;
6310 keep_trying = ISC_TRUE;
6315 * Enforce delegations only zones like NET and COM.
6317 if (!ISFORWARDER(query->addrinfo) &&
6318 dns_view_isdelegationonly(fctx->res->view, &fctx->domain) &&
6319 !dns_name_equal(&fctx->domain, &fctx->name) &&
6320 fix_mustbedelegationornxdomain(message, fctx)) {
6321 char namebuf[DNS_NAME_FORMATSIZE];
6322 char domainbuf[DNS_NAME_FORMATSIZE];
6323 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
6327 dns_name_format(&fctx->name, namebuf, sizeof(namebuf));
6328 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
6329 dns_rdatatype_format(fctx->type, typebuf, sizeof(typebuf));
6330 dns_rdataclass_format(fctx->res->rdclass, classbuf,
6332 isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf,
6335 isc_log_write(dns_lctx, DNS_LOGCATEGORY_DELEGATION_ONLY,
6336 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
6337 "enforced delegation-only for '%s' (%s/%s/%s) "
6339 domainbuf, namebuf, typebuf, classbuf, addrbuf);
6342 if ((fctx->res->options & DNS_RESOLVER_CHECKNAMES) != 0)
6343 checknames(message);
6348 fctx->attributes &= ~(FCTX_ATTR_WANTNCACHE | FCTX_ATTR_WANTCACHE);
6351 * Did we get any answers?
6353 if (message->counts[DNS_SECTION_ANSWER] > 0 &&
6354 (message->rcode == dns_rcode_noerror ||
6355 message->rcode == dns_rcode_nxdomain)) {
6357 * We've got answers. However, if we sent
6358 * a BIND 8 server an NS query, it may have
6359 * incorrectly responded with a non-authoritative
6360 * answer instead of a referral. Since this
6361 * answer lacks the SIGs necessary to do DNSSEC
6362 * validation, we must invoke the following special
6363 * kludge to treat it as a referral.
6365 if (fctx->type == dns_rdatatype_ns &&
6366 (message->flags & DNS_MESSAGEFLAG_AA) == 0 &&
6367 !ISFORWARDER(query->addrinfo))
6369 result = noanswer_response(fctx, NULL, ISC_TRUE);
6370 if (result != DNS_R_DELEGATION) {
6372 * The answer section must have contained
6373 * something other than the NS records
6374 * we asked for. Since AA is not set
6375 * and the server is not a forwarder,
6376 * it is technically lame and it's easier
6377 * to treat it as such than to figure out
6378 * some more elaborate course of action.
6380 broken_server = DNS_R_LAME;
6381 keep_trying = ISC_TRUE;
6384 goto force_referral;
6386 result = answer_response(fctx);
6387 if (result != ISC_R_SUCCESS) {
6388 if (result == DNS_R_FORMERR)
6389 keep_trying = ISC_TRUE;
6392 } else if (message->counts[DNS_SECTION_AUTHORITY] > 0 ||
6393 message->rcode == dns_rcode_noerror ||
6394 message->rcode == dns_rcode_nxdomain) {
6396 * NXDOMAIN, NXRDATASET, or referral.
6398 result = noanswer_response(fctx, NULL, ISC_FALSE);
6399 if (result == DNS_R_CHASEDSSERVERS) {
6400 } else if (result == DNS_R_DELEGATION) {
6403 * We don't have the answer, but we know a better
6406 get_nameservers = ISC_TRUE;
6407 keep_trying = ISC_TRUE;
6409 * We have a new set of name servers, and it
6410 * has not experienced any restarts yet.
6415 * Update local statistics counters collected for each
6419 fctx->querysent = 0;
6420 fctx->lamecount = 0;
6425 result = ISC_R_SUCCESS;
6426 } else if (result != ISC_R_SUCCESS) {
6428 * Something has gone wrong.
6430 if (result == DNS_R_FORMERR)
6431 keep_trying = ISC_TRUE;
6436 * The server is insane.
6439 broken_server = DNS_R_UNEXPECTEDRCODE;
6440 keep_trying = ISC_TRUE;
6445 * Follow additional section data chains.
6447 chase_additional(fctx);
6450 * Cache the cacheable parts of the message. This may also cause
6451 * work to be queued to the DNSSEC validator.
6453 if (WANTCACHE(fctx)) {
6454 result = cache_message(fctx, query->addrinfo, now);
6455 if (result != ISC_R_SUCCESS)
6460 * Ncache the negatively cacheable parts of the message. This may
6461 * also cause work to be queued to the DNSSEC validator.
6463 if (WANTNCACHE(fctx)) {
6464 dns_rdatatype_t covers;
6465 if (message->rcode == dns_rcode_nxdomain)
6466 covers = dns_rdatatype_any;
6468 covers = fctx->type;
6471 * Cache any negative cache entries in the message.
6473 result = ncache_message(fctx, query->addrinfo, covers, now);
6478 * Remember the query's addrinfo, in case we need to mark the
6481 addrinfo = query->addrinfo;
6486 * XXXRTH Don't cancel the query if waiting for validation?
6488 fctx_cancelquery(&query, &devent, finish, ISC_FALSE);
6491 if (result == DNS_R_FORMERR)
6492 broken_server = DNS_R_FORMERR;
6493 if (broken_server != ISC_R_SUCCESS) {
6495 * Add this server to the list of bad servers for
6498 add_bad(fctx, addrinfo, broken_server, broken_type);
6501 if (get_nameservers) {
6503 dns_fixedname_init(&foundname);
6504 fname = dns_fixedname_name(&foundname);
6505 if (result != ISC_R_SUCCESS) {
6506 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6510 if (dns_rdatatype_atparent(fctx->type))
6511 findoptions |= DNS_DBFIND_NOEXACT;
6512 if ((options & DNS_FETCHOPT_UNSHARED) == 0)
6515 name = &fctx->domain;
6516 result = dns_view_findzonecut(fctx->res->view,
6522 if (result != ISC_R_SUCCESS) {
6523 FCTXTRACE("couldn't find a zonecut");
6524 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6527 if (!dns_name_issubdomain(fname, &fctx->domain)) {
6529 * The best nameservers are now above our
6532 FCTXTRACE("nameservers now above QDOMAIN");
6533 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6536 dns_name_free(&fctx->domain,
6537 fctx->res->buckets[fctx->bucketnum].mctx);
6538 dns_name_init(&fctx->domain, NULL);
6539 result = dns_name_dup(fname,
6540 fctx->res->buckets[fctx->bucketnum].mctx,
6542 if (result != ISC_R_SUCCESS) {
6543 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6546 fctx_cancelqueries(fctx, ISC_TRUE);
6547 fctx_cleanupfinds(fctx);
6548 fctx_cleanupaltfinds(fctx);
6549 fctx_cleanupforwaddrs(fctx);
6550 fctx_cleanupaltaddrs(fctx);
6555 fctx_try(fctx, !get_nameservers);
6556 } else if (resend) {
6558 * Resend (probably with changed options).
6560 FCTXTRACE("resend");
6561 inc_stats(fctx->res, dns_resstatscounter_retry);
6562 result = fctx_query(fctx, addrinfo, options);
6563 if (result != ISC_R_SUCCESS)
6564 fctx_done(fctx, result, __LINE__);
6565 } else if (result == ISC_R_SUCCESS && !HAVE_ANSWER(fctx)) {
6567 * All has gone well so far, but we are waiting for the
6568 * DNSSEC validator to validate the answer.
6570 FCTXTRACE("wait for validator");
6571 fctx_cancelqueries(fctx, ISC_TRUE);
6573 * We must not retransmit while the validator is working;
6574 * it has references to the current rmessage.
6576 result = fctx_stopidletimer(fctx);
6577 if (result != ISC_R_SUCCESS)
6578 fctx_done(fctx, result, __LINE__);
6579 } else if (result == DNS_R_CHASEDSSERVERS) {
6581 add_bad(fctx, addrinfo, result, broken_type);
6582 fctx_cancelqueries(fctx, ISC_TRUE);
6583 fctx_cleanupfinds(fctx);
6584 fctx_cleanupforwaddrs(fctx);
6586 n = dns_name_countlabels(&fctx->name);
6587 dns_name_getlabelsequence(&fctx->name, 1, n - 1, &fctx->nsname);
6589 FCTXTRACE("suspending DS lookup to find parent's NS records");
6591 result = dns_resolver_createfetch(fctx->res, &fctx->nsname,
6593 NULL, NULL, NULL, 0, task,
6594 resume_dslookup, fctx,
6595 &fctx->nsrrset, NULL,
6597 if (result != ISC_R_SUCCESS)
6598 fctx_done(fctx, result, __LINE__);
6599 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
6601 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
6602 result = fctx_stopidletimer(fctx);
6603 if (result != ISC_R_SUCCESS)
6604 fctx_done(fctx, result, __LINE__);
6609 fctx_done(fctx, result, __LINE__);
6615 *** Resolver Methods
6619 destroy(dns_resolver_t *res) {
6623 REQUIRE(res->references == 0);
6624 REQUIRE(!res->priming);
6625 REQUIRE(res->primefetch == NULL);
6629 INSIST(res->nfctx == 0);
6631 DESTROYLOCK(&res->primelock);
6632 DESTROYLOCK(&res->nlock);
6633 DESTROYLOCK(&res->lock);
6634 for (i = 0; i < res->nbuckets; i++) {
6635 INSIST(ISC_LIST_EMPTY(res->buckets[i].fctxs));
6636 isc_task_shutdown(res->buckets[i].task);
6637 isc_task_detach(&res->buckets[i].task);
6638 DESTROYLOCK(&res->buckets[i].lock);
6639 isc_mem_detach(&res->buckets[i].mctx);
6641 isc_mem_put(res->mctx, res->buckets,
6642 res->nbuckets * sizeof(fctxbucket_t));
6643 if (res->dispatchv4 != NULL)
6644 dns_dispatch_detach(&res->dispatchv4);
6645 if (res->dispatchv6 != NULL)
6646 dns_dispatch_detach(&res->dispatchv6);
6647 while ((a = ISC_LIST_HEAD(res->alternates)) != NULL) {
6648 ISC_LIST_UNLINK(res->alternates, a, link);
6650 dns_name_free(&a->_u._n.name, res->mctx);
6651 isc_mem_put(res->mctx, a, sizeof(*a));
6653 dns_resolver_reset_algorithms(res);
6654 dns_resolver_resetmustbesecure(res);
6656 isc_rwlock_destroy(&res->alglock);
6659 isc_rwlock_destroy(&res->mbslock);
6661 isc_timer_detach(&res->spillattimer);
6663 isc_mem_put(res->mctx, res, sizeof(*res));
6667 send_shutdown_events(dns_resolver_t *res) {
6668 isc_event_t *event, *next_event;
6672 * Caller must be holding the resolver lock.
6675 for (event = ISC_LIST_HEAD(res->whenshutdown);
6677 event = next_event) {
6678 next_event = ISC_LIST_NEXT(event, ev_link);
6679 ISC_LIST_UNLINK(res->whenshutdown, event, ev_link);
6680 etask = event->ev_sender;
6681 event->ev_sender = res;
6682 isc_task_sendanddetach(&etask, &event);
6687 empty_bucket(dns_resolver_t *res) {
6688 RTRACE("empty_bucket");
6692 INSIST(res->activebuckets > 0);
6693 res->activebuckets--;
6694 if (res->activebuckets == 0)
6695 send_shutdown_events(res);
6701 spillattimer_countdown(isc_task_t *task, isc_event_t *event) {
6702 dns_resolver_t *res = event->ev_arg;
6703 isc_result_t result;
6705 isc_boolean_t logit = ISC_FALSE;
6707 REQUIRE(VALID_RESOLVER(res));
6712 INSIST(!res->exiting);
6713 if (res->spillat > res->spillatmin) {
6717 if (res->spillat <= res->spillatmin) {
6718 result = isc_timer_reset(res->spillattimer,
6719 isc_timertype_inactive, NULL,
6721 RUNTIME_CHECK(result == ISC_R_SUCCESS);
6723 count = res->spillat;
6726 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
6727 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
6728 "clients-per-query decreased to %u", count);
6730 isc_event_free(&event);
6734 dns_resolver_create(dns_view_t *view,
6735 isc_taskmgr_t *taskmgr, unsigned int ntasks,
6736 isc_socketmgr_t *socketmgr,
6737 isc_timermgr_t *timermgr,
6738 unsigned int options,
6739 dns_dispatchmgr_t *dispatchmgr,
6740 dns_dispatch_t *dispatchv4,
6741 dns_dispatch_t *dispatchv6,
6742 dns_resolver_t **resp)
6744 dns_resolver_t *res;
6745 isc_result_t result = ISC_R_SUCCESS;
6746 unsigned int i, buckets_created = 0;
6747 isc_task_t *task = NULL;
6752 * Create a resolver.
6755 REQUIRE(DNS_VIEW_VALID(view));
6756 REQUIRE(ntasks > 0);
6757 REQUIRE(resp != NULL && *resp == NULL);
6758 REQUIRE(dispatchmgr != NULL);
6759 REQUIRE(dispatchv4 != NULL || dispatchv6 != NULL);
6761 res = isc_mem_get(view->mctx, sizeof(*res));
6763 return (ISC_R_NOMEMORY);
6765 res->mctx = view->mctx;
6766 res->rdclass = view->rdclass;
6767 res->socketmgr = socketmgr;
6768 res->timermgr = timermgr;
6769 res->taskmgr = taskmgr;
6770 res->dispatchmgr = dispatchmgr;
6772 res->options = options;
6774 ISC_LIST_INIT(res->alternates);
6775 res->udpsize = RECV_BUFFER_SIZE;
6776 res->algorithms = NULL;
6777 res->mustbesecure = NULL;
6778 res->spillatmin = res->spillat = 10;
6779 res->spillatmax = 100;
6780 res->spillattimer = NULL;
6781 res->zero_no_soa_ttl = ISC_FALSE;
6783 res->nextdisp = 0; /* meaningless at this point, but init it */
6784 res->nbuckets = ntasks;
6785 res->activebuckets = ntasks;
6786 res->buckets = isc_mem_get(view->mctx,
6787 ntasks * sizeof(fctxbucket_t));
6788 if (res->buckets == NULL) {
6789 result = ISC_R_NOMEMORY;
6792 for (i = 0; i < ntasks; i++) {
6793 result = isc_mutex_init(&res->buckets[i].lock);
6794 if (result != ISC_R_SUCCESS)
6795 goto cleanup_buckets;
6796 res->buckets[i].task = NULL;
6797 result = isc_task_create(taskmgr, 0, &res->buckets[i].task);
6798 if (result != ISC_R_SUCCESS) {
6799 DESTROYLOCK(&res->buckets[i].lock);
6800 goto cleanup_buckets;
6802 res->buckets[i].mctx = NULL;
6803 snprintf(name, sizeof(name), "res%u", i);
6804 #ifdef ISC_PLATFORM_USETHREADS
6806 * Use a separate memory context for each bucket to reduce
6807 * contention among multiple threads. Do this only when
6808 * enabling threads because it will be require more memory.
6810 result = isc_mem_create(0, 0, &res->buckets[i].mctx);
6811 if (result != ISC_R_SUCCESS) {
6812 isc_task_detach(&res->buckets[i].task);
6813 DESTROYLOCK(&res->buckets[i].lock);
6814 goto cleanup_buckets;
6816 isc_mem_setname(res->buckets[i].mctx, name, NULL);
6818 isc_mem_attach(view->mctx, &res->buckets[i].mctx);
6820 isc_task_setname(res->buckets[i].task, name, res);
6821 ISC_LIST_INIT(res->buckets[i].fctxs);
6822 res->buckets[i].exiting = ISC_FALSE;
6826 res->dispatchv4 = NULL;
6827 if (dispatchv4 != NULL) {
6828 dns_dispatch_attach(dispatchv4, &res->dispatchv4);
6829 dispattr = dns_dispatch_getattributes(dispatchv4);
6831 ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
6834 res->dispatchv6 = NULL;
6835 if (dispatchv6 != NULL) {
6836 dns_dispatch_attach(dispatchv6, &res->dispatchv6);
6837 dispattr = dns_dispatch_getattributes(dispatchv6);
6839 ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
6842 res->references = 1;
6843 res->exiting = ISC_FALSE;
6844 res->frozen = ISC_FALSE;
6845 ISC_LIST_INIT(res->whenshutdown);
6846 res->priming = ISC_FALSE;
6847 res->primefetch = NULL;
6850 result = isc_mutex_init(&res->lock);
6851 if (result != ISC_R_SUCCESS)
6852 goto cleanup_dispatches;
6854 result = isc_mutex_init(&res->nlock);
6855 if (result != ISC_R_SUCCESS)
6858 result = isc_mutex_init(&res->primelock);
6859 if (result != ISC_R_SUCCESS)
6863 result = isc_task_create(taskmgr, 0, &task);
6864 if (result != ISC_R_SUCCESS)
6865 goto cleanup_primelock;
6867 result = isc_timer_create(timermgr, isc_timertype_inactive, NULL, NULL,
6868 task, spillattimer_countdown, res,
6869 &res->spillattimer);
6870 isc_task_detach(&task);
6871 if (result != ISC_R_SUCCESS)
6872 goto cleanup_primelock;
6875 result = isc_rwlock_init(&res->alglock, 0, 0);
6876 if (result != ISC_R_SUCCESS)
6877 goto cleanup_spillattimer;
6880 result = isc_rwlock_init(&res->mbslock, 0, 0);
6881 if (result != ISC_R_SUCCESS)
6882 goto cleanup_alglock;
6885 res->magic = RES_MAGIC;
6889 return (ISC_R_SUCCESS);
6894 isc_rwlock_destroy(&res->alglock);
6897 #if USE_ALGLOCK || USE_MBSLOCK
6898 cleanup_spillattimer:
6899 isc_timer_detach(&res->spillattimer);
6903 DESTROYLOCK(&res->primelock);
6906 DESTROYLOCK(&res->nlock);
6909 DESTROYLOCK(&res->lock);
6912 if (res->dispatchv6 != NULL)
6913 dns_dispatch_detach(&res->dispatchv6);
6914 if (res->dispatchv4 != NULL)
6915 dns_dispatch_detach(&res->dispatchv4);
6918 for (i = 0; i < buckets_created; i++) {
6919 isc_mem_detach(&res->buckets[i].mctx);
6920 DESTROYLOCK(&res->buckets[i].lock);
6921 isc_task_shutdown(res->buckets[i].task);
6922 isc_task_detach(&res->buckets[i].task);
6924 isc_mem_put(view->mctx, res->buckets,
6925 res->nbuckets * sizeof(fctxbucket_t));
6928 isc_mem_put(view->mctx, res, sizeof(*res));
6934 prime_done(isc_task_t *task, isc_event_t *event) {
6935 dns_resolver_t *res;
6936 dns_fetchevent_t *fevent;
6938 dns_db_t *db = NULL;
6940 REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
6941 fevent = (dns_fetchevent_t *)event;
6942 res = event->ev_arg;
6943 REQUIRE(VALID_RESOLVER(res));
6949 INSIST(res->priming);
6950 res->priming = ISC_FALSE;
6951 LOCK(&res->primelock);
6952 fetch = res->primefetch;
6953 res->primefetch = NULL;
6954 UNLOCK(&res->primelock);
6958 if (fevent->result == ISC_R_SUCCESS &&
6959 res->view->cache != NULL && res->view->hints != NULL) {
6960 dns_cache_attachdb(res->view->cache, &db);
6961 dns_root_checkhints(res->view, res->view->hints, db);
6965 if (fevent->node != NULL)
6966 dns_db_detachnode(fevent->db, &fevent->node);
6967 if (fevent->db != NULL)
6968 dns_db_detach(&fevent->db);
6969 if (dns_rdataset_isassociated(fevent->rdataset))
6970 dns_rdataset_disassociate(fevent->rdataset);
6971 INSIST(fevent->sigrdataset == NULL);
6973 isc_mem_put(res->mctx, fevent->rdataset, sizeof(*fevent->rdataset));
6975 isc_event_free(&event);
6976 dns_resolver_destroyfetch(&fetch);
6980 dns_resolver_prime(dns_resolver_t *res) {
6981 isc_boolean_t want_priming = ISC_FALSE;
6982 dns_rdataset_t *rdataset;
6983 isc_result_t result;
6985 REQUIRE(VALID_RESOLVER(res));
6986 REQUIRE(res->frozen);
6988 RTRACE("dns_resolver_prime");
6992 if (!res->exiting && !res->priming) {
6993 INSIST(res->primefetch == NULL);
6994 res->priming = ISC_TRUE;
6995 want_priming = ISC_TRUE;
7002 * To avoid any possible recursive locking problems, we
7003 * start the priming fetch like any other fetch, and holding
7004 * no resolver locks. No one else will try to start it
7005 * because we're the ones who set res->priming to true.
7006 * Any other callers of dns_resolver_prime() while we're
7007 * running will see that res->priming is already true and
7011 rdataset = isc_mem_get(res->mctx, sizeof(*rdataset));
7012 if (rdataset == NULL) {
7014 INSIST(res->priming);
7015 INSIST(res->primefetch == NULL);
7016 res->priming = ISC_FALSE;
7020 dns_rdataset_init(rdataset);
7021 LOCK(&res->primelock);
7022 result = dns_resolver_createfetch(res, dns_rootname,
7024 NULL, NULL, NULL, 0,
7025 res->buckets[0].task,
7027 res, rdataset, NULL,
7029 UNLOCK(&res->primelock);
7030 if (result != ISC_R_SUCCESS) {
7032 INSIST(res->priming);
7033 res->priming = ISC_FALSE;
7040 dns_resolver_freeze(dns_resolver_t *res) {
7046 REQUIRE(VALID_RESOLVER(res));
7047 REQUIRE(!res->frozen);
7049 res->frozen = ISC_TRUE;
7053 dns_resolver_attach(dns_resolver_t *source, dns_resolver_t **targetp) {
7054 REQUIRE(VALID_RESOLVER(source));
7055 REQUIRE(targetp != NULL && *targetp == NULL);
7057 RRTRACE(source, "attach");
7058 LOCK(&source->lock);
7059 REQUIRE(!source->exiting);
7061 INSIST(source->references > 0);
7062 source->references++;
7063 INSIST(source->references != 0);
7064 UNLOCK(&source->lock);
7070 dns_resolver_whenshutdown(dns_resolver_t *res, isc_task_t *task,
7071 isc_event_t **eventp)
7076 REQUIRE(VALID_RESOLVER(res));
7077 REQUIRE(eventp != NULL);
7084 if (res->exiting && res->activebuckets == 0) {
7086 * We're already shutdown. Send the event.
7088 event->ev_sender = res;
7089 isc_task_send(task, &event);
7092 isc_task_attach(task, &clone);
7093 event->ev_sender = clone;
7094 ISC_LIST_APPEND(res->whenshutdown, event, ev_link);
7101 dns_resolver_shutdown(dns_resolver_t *res) {
7105 isc_result_t result;
7107 REQUIRE(VALID_RESOLVER(res));
7113 if (!res->exiting) {
7115 res->exiting = ISC_TRUE;
7117 for (i = 0; i < res->nbuckets; i++) {
7118 LOCK(&res->buckets[i].lock);
7119 for (fctx = ISC_LIST_HEAD(res->buckets[i].fctxs);
7121 fctx = ISC_LIST_NEXT(fctx, link))
7122 fctx_shutdown(fctx);
7123 if (res->dispatchv4 != NULL && !res->exclusivev4) {
7124 sock = dns_dispatch_getsocket(res->dispatchv4);
7125 isc_socket_cancel(sock, res->buckets[i].task,
7126 ISC_SOCKCANCEL_ALL);
7128 if (res->dispatchv6 != NULL && !res->exclusivev6) {
7129 sock = dns_dispatch_getsocket(res->dispatchv6);
7130 isc_socket_cancel(sock, res->buckets[i].task,
7131 ISC_SOCKCANCEL_ALL);
7133 res->buckets[i].exiting = ISC_TRUE;
7134 if (ISC_LIST_EMPTY(res->buckets[i].fctxs)) {
7135 INSIST(res->activebuckets > 0);
7136 res->activebuckets--;
7138 UNLOCK(&res->buckets[i].lock);
7140 if (res->activebuckets == 0)
7141 send_shutdown_events(res);
7142 result = isc_timer_reset(res->spillattimer,
7143 isc_timertype_inactive, NULL,
7145 RUNTIME_CHECK(result == ISC_R_SUCCESS);
7152 dns_resolver_detach(dns_resolver_t **resp) {
7153 dns_resolver_t *res;
7154 isc_boolean_t need_destroy = ISC_FALSE;
7156 REQUIRE(resp != NULL);
7158 REQUIRE(VALID_RESOLVER(res));
7164 INSIST(res->references > 0);
7166 if (res->references == 0) {
7167 INSIST(res->exiting && res->activebuckets == 0);
7168 need_destroy = ISC_TRUE;
7179 static inline isc_boolean_t
7180 fctx_match(fetchctx_t *fctx, dns_name_t *name, dns_rdatatype_t type,
7181 unsigned int options)
7183 if (fctx->type != type || fctx->options != options)
7185 return (dns_name_equal(&fctx->name, name));
7189 log_fetch(dns_name_t *name, dns_rdatatype_t type) {
7190 char namebuf[DNS_NAME_FORMATSIZE];
7191 char typebuf[DNS_RDATATYPE_FORMATSIZE];
7192 int level = ISC_LOG_DEBUG(1);
7194 if (! isc_log_wouldlog(dns_lctx, level))
7197 dns_name_format(name, namebuf, sizeof(namebuf));
7198 dns_rdatatype_format(type, typebuf, sizeof(typebuf));
7200 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
7201 DNS_LOGMODULE_RESOLVER, level,
7202 "createfetch: %s %s", namebuf, typebuf);
7206 dns_resolver_createfetch(dns_resolver_t *res, dns_name_t *name,
7207 dns_rdatatype_t type,
7208 dns_name_t *domain, dns_rdataset_t *nameservers,
7209 dns_forwarders_t *forwarders,
7210 unsigned int options, isc_task_t *task,
7211 isc_taskaction_t action, void *arg,
7212 dns_rdataset_t *rdataset,
7213 dns_rdataset_t *sigrdataset,
7214 dns_fetch_t **fetchp)
7216 return (dns_resolver_createfetch2(res, name, type, domain,
7217 nameservers, forwarders, NULL, 0,
7218 options, task, action, arg,
7219 rdataset, sigrdataset, fetchp));
7223 dns_resolver_createfetch2(dns_resolver_t *res, dns_name_t *name,
7224 dns_rdatatype_t type,
7225 dns_name_t *domain, dns_rdataset_t *nameservers,
7226 dns_forwarders_t *forwarders,
7227 isc_sockaddr_t *client, dns_messageid_t id,
7228 unsigned int options, isc_task_t *task,
7229 isc_taskaction_t action, void *arg,
7230 dns_rdataset_t *rdataset,
7231 dns_rdataset_t *sigrdataset,
7232 dns_fetch_t **fetchp)
7235 fetchctx_t *fctx = NULL;
7236 isc_result_t result = ISC_R_SUCCESS;
7237 unsigned int bucketnum;
7238 isc_boolean_t new_fctx = ISC_FALSE;
7240 unsigned int count = 0;
7241 unsigned int spillat;
7242 unsigned int spillatmin;
7246 REQUIRE(VALID_RESOLVER(res));
7247 REQUIRE(res->frozen);
7248 /* XXXRTH Check for meta type */
7249 if (domain != NULL) {
7250 REQUIRE(DNS_RDATASET_VALID(nameservers));
7251 REQUIRE(nameservers->type == dns_rdatatype_ns);
7253 REQUIRE(nameservers == NULL);
7254 REQUIRE(forwarders == NULL);
7255 REQUIRE(!dns_rdataset_isassociated(rdataset));
7256 REQUIRE(sigrdataset == NULL ||
7257 !dns_rdataset_isassociated(sigrdataset));
7258 REQUIRE(fetchp != NULL && *fetchp == NULL);
7260 log_fetch(name, type);
7263 * XXXRTH use a mempool?
7265 fetch = isc_mem_get(res->mctx, sizeof(*fetch));
7267 return (ISC_R_NOMEMORY);
7269 bucketnum = dns_name_fullhash(name, ISC_FALSE) % res->nbuckets;
7272 spillat = res->spillat;
7273 spillatmin = res->spillatmin;
7275 LOCK(&res->buckets[bucketnum].lock);
7277 if (res->buckets[bucketnum].exiting) {
7278 result = ISC_R_SHUTTINGDOWN;
7282 if ((options & DNS_FETCHOPT_UNSHARED) == 0) {
7283 for (fctx = ISC_LIST_HEAD(res->buckets[bucketnum].fctxs);
7285 fctx = ISC_LIST_NEXT(fctx, link)) {
7286 if (fctx_match(fctx, name, type, options))
7292 * Is this a duplicate?
7294 if (fctx != NULL && client != NULL) {
7295 dns_fetchevent_t *fevent;
7296 for (fevent = ISC_LIST_HEAD(fctx->events);
7298 fevent = ISC_LIST_NEXT(fevent, ev_link)) {
7299 if (fevent->client != NULL && fevent->id == id &&
7300 isc_sockaddr_equal(fevent->client, client)) {
7301 result = DNS_R_DUPLICATE;
7307 if (count >= spillatmin && spillatmin != 0) {
7308 INSIST(fctx != NULL);
7309 if (count >= spillat)
7310 fctx->spilled = ISC_TRUE;
7311 if (fctx->spilled) {
7312 result = DNS_R_DROP;
7318 * If we didn't have a fetch, would attach to a done fetch, this
7319 * fetch has already cloned its results, or if the fetch has gone
7320 * "idle" (no one was interested in it), we need to start a new
7321 * fetch instead of joining with the existing one.
7324 fctx->state == fetchstate_done ||
7326 ISC_LIST_EMPTY(fctx->events)) {
7328 result = fctx_create(res, name, type, domain, nameservers,
7329 options, bucketnum, &fctx);
7330 if (result != ISC_R_SUCCESS)
7332 new_fctx = ISC_TRUE;
7335 result = fctx_join(fctx, task, client, id, action, arg,
7336 rdataset, sigrdataset, fetch);
7338 if (result == ISC_R_SUCCESS) {
7342 event = &fctx->control_event;
7343 ISC_EVENT_INIT(event, sizeof(*event), 0, NULL,
7344 DNS_EVENT_FETCHCONTROL,
7345 fctx_start, fctx, NULL,
7347 isc_task_send(res->buckets[bucketnum].task, &event);
7350 * We don't care about the result of fctx_destroy()
7351 * since we know we're not exiting.
7353 (void)fctx_destroy(fctx);
7358 UNLOCK(&res->buckets[bucketnum].lock);
7360 if (result == ISC_R_SUCCESS) {
7364 isc_mem_put(res->mctx, fetch, sizeof(*fetch));
7370 dns_resolver_cancelfetch(dns_fetch_t *fetch) {
7372 dns_resolver_t *res;
7373 dns_fetchevent_t *event, *next_event;
7376 REQUIRE(DNS_FETCH_VALID(fetch));
7377 fctx = fetch->private;
7378 REQUIRE(VALID_FCTX(fctx));
7381 FTRACE("cancelfetch");
7383 LOCK(&res->buckets[fctx->bucketnum].lock);
7386 * Find the completion event for this fetch (as opposed
7387 * to those for other fetches that have joined the same
7388 * fctx) and send it with result = ISC_R_CANCELED.
7391 if (fctx->state != fetchstate_done) {
7392 for (event = ISC_LIST_HEAD(fctx->events);
7394 event = next_event) {
7395 next_event = ISC_LIST_NEXT(event, ev_link);
7396 if (event->fetch == fetch) {
7397 ISC_LIST_UNLINK(fctx->events, event, ev_link);
7402 if (event != NULL) {
7403 etask = event->ev_sender;
7404 event->ev_sender = fctx;
7405 event->result = ISC_R_CANCELED;
7406 isc_task_sendanddetach(&etask, ISC_EVENT_PTR(&event));
7409 * The fctx continues running even if no fetches remain;
7410 * the answer is still cached.
7413 UNLOCK(&res->buckets[fctx->bucketnum].lock);
7417 dns_resolver_destroyfetch(dns_fetch_t **fetchp) {
7419 dns_resolver_t *res;
7420 dns_fetchevent_t *event, *next_event;
7422 unsigned int bucketnum;
7423 isc_boolean_t bucket_empty = ISC_FALSE;
7425 REQUIRE(fetchp != NULL);
7427 REQUIRE(DNS_FETCH_VALID(fetch));
7428 fctx = fetch->private;
7429 REQUIRE(VALID_FCTX(fctx));
7432 FTRACE("destroyfetch");
7434 bucketnum = fctx->bucketnum;
7435 LOCK(&res->buckets[bucketnum].lock);
7438 * Sanity check: the caller should have gotten its event before
7439 * trying to destroy the fetch.
7442 if (fctx->state != fetchstate_done) {
7443 for (event = ISC_LIST_HEAD(fctx->events);
7445 event = next_event) {
7446 next_event = ISC_LIST_NEXT(event, ev_link);
7447 RUNTIME_CHECK(event->fetch != fetch);
7451 INSIST(fctx->references > 0);
7453 if (fctx->references == 0) {
7455 * No one cares about the result of this fetch anymore.
7457 if (fctx->pending == 0 && fctx->nqueries == 0 &&
7458 ISC_LIST_EMPTY(fctx->validators) &&
7459 SHUTTINGDOWN(fctx)) {
7461 * This fctx is already shutdown; we were just
7462 * waiting for the last reference to go away.
7464 bucket_empty = fctx_destroy(fctx);
7467 * Initiate shutdown.
7469 fctx_shutdown(fctx);
7473 UNLOCK(&res->buckets[bucketnum].lock);
7475 isc_mem_put(res->mctx, fetch, sizeof(*fetch));
7483 dns_resolver_logfetch(dns_fetch_t *fetch, isc_log_t *lctx,
7484 isc_logcategory_t *category, isc_logmodule_t *module,
7485 int level, isc_boolean_t duplicateok)
7488 dns_resolver_t *res;
7489 char domainbuf[DNS_NAME_FORMATSIZE];
7491 REQUIRE(DNS_FETCH_VALID(fetch));
7492 fctx = fetch->private;
7493 REQUIRE(VALID_FCTX(fctx));
7496 LOCK(&res->buckets[fctx->bucketnum].lock);
7498 INSIST(fctx->exitline >= 0);
7499 if (!fctx->logged || duplicateok) {
7500 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
7501 isc_log_write(lctx, category, module, level,
7502 "fetch completed at %s:%d for %s in "
7503 "%" ISC_PRINT_QUADFORMAT "u."
7504 "%06" ISC_PRINT_QUADFORMAT "u: %s/%s "
7505 "[domain:%s,referral:%u,restart:%u,qrysent:%u,"
7506 "timeout:%u,lame:%u,neterr:%u,badresp:%u,"
7507 "adberr:%u,findfail:%u,valfail:%u]",
7508 __FILE__, fctx->exitline, fctx->info,
7509 fctx->duration / 1000000,
7510 fctx->duration % 1000000,
7511 isc_result_totext(fctx->result),
7512 isc_result_totext(fctx->vresult), domainbuf,
7513 fctx->referrals, fctx->restarts,
7514 fctx->querysent, fctx->timeouts, fctx->lamecount,
7515 fctx->neterr, fctx->badresp, fctx->adberr,
7516 fctx->findfail, fctx->valfail);
7517 fctx->logged = ISC_TRUE;
7520 UNLOCK(&res->buckets[fctx->bucketnum].lock);
7524 dns_resolver_dispatchmgr(dns_resolver_t *resolver) {
7525 REQUIRE(VALID_RESOLVER(resolver));
7526 return (resolver->dispatchmgr);
7530 dns_resolver_dispatchv4(dns_resolver_t *resolver) {
7531 REQUIRE(VALID_RESOLVER(resolver));
7532 return (resolver->dispatchv4);
7536 dns_resolver_dispatchv6(dns_resolver_t *resolver) {
7537 REQUIRE(VALID_RESOLVER(resolver));
7538 return (resolver->dispatchv6);
7542 dns_resolver_socketmgr(dns_resolver_t *resolver) {
7543 REQUIRE(VALID_RESOLVER(resolver));
7544 return (resolver->socketmgr);
7548 dns_resolver_taskmgr(dns_resolver_t *resolver) {
7549 REQUIRE(VALID_RESOLVER(resolver));
7550 return (resolver->taskmgr);
7554 dns_resolver_getlamettl(dns_resolver_t *resolver) {
7555 REQUIRE(VALID_RESOLVER(resolver));
7556 return (resolver->lame_ttl);
7560 dns_resolver_setlamettl(dns_resolver_t *resolver, isc_uint32_t lame_ttl) {
7561 REQUIRE(VALID_RESOLVER(resolver));
7562 resolver->lame_ttl = lame_ttl;
7566 dns_resolver_nrunning(dns_resolver_t *resolver) {
7568 LOCK(&resolver->nlock);
7569 n = resolver->nfctx;
7570 UNLOCK(&resolver->nlock);
7575 dns_resolver_addalternate(dns_resolver_t *resolver, isc_sockaddr_t *alt,
7576 dns_name_t *name, in_port_t port) {
7578 isc_result_t result;
7580 REQUIRE(VALID_RESOLVER(resolver));
7581 REQUIRE(!resolver->frozen);
7582 REQUIRE((alt == NULL) ^ (name == NULL));
7584 a = isc_mem_get(resolver->mctx, sizeof(*a));
7586 return (ISC_R_NOMEMORY);
7588 a->isaddress = ISC_TRUE;
7591 a->isaddress = ISC_FALSE;
7592 a->_u._n.port = port;
7593 dns_name_init(&a->_u._n.name, NULL);
7594 result = dns_name_dup(name, resolver->mctx, &a->_u._n.name);
7595 if (result != ISC_R_SUCCESS) {
7596 isc_mem_put(resolver->mctx, a, sizeof(*a));
7600 ISC_LINK_INIT(a, link);
7601 ISC_LIST_APPEND(resolver->alternates, a, link);
7603 return (ISC_R_SUCCESS);
7607 dns_resolver_setudpsize(dns_resolver_t *resolver, isc_uint16_t udpsize) {
7608 REQUIRE(VALID_RESOLVER(resolver));
7609 resolver->udpsize = udpsize;
7613 dns_resolver_getudpsize(dns_resolver_t *resolver) {
7614 REQUIRE(VALID_RESOLVER(resolver));
7615 return (resolver->udpsize);
7619 free_algorithm(void *node, void *arg) {
7620 unsigned char *algorithms = node;
7621 isc_mem_t *mctx = arg;
7623 isc_mem_put(mctx, algorithms, *algorithms);
7627 dns_resolver_reset_algorithms(dns_resolver_t *resolver) {
7629 REQUIRE(VALID_RESOLVER(resolver));
7632 RWLOCK(&resolver->alglock, isc_rwlocktype_write);
7634 if (resolver->algorithms != NULL)
7635 dns_rbt_destroy(&resolver->algorithms);
7637 RWUNLOCK(&resolver->alglock, isc_rwlocktype_write);
7642 dns_resolver_disable_algorithm(dns_resolver_t *resolver, dns_name_t *name,
7645 unsigned int len, mask;
7647 unsigned char *algorithms;
7648 isc_result_t result;
7649 dns_rbtnode_t *node = NULL;
7651 REQUIRE(VALID_RESOLVER(resolver));
7653 return (ISC_R_RANGE);
7656 RWLOCK(&resolver->alglock, isc_rwlocktype_write);
7658 if (resolver->algorithms == NULL) {
7659 result = dns_rbt_create(resolver->mctx, free_algorithm,
7660 resolver->mctx, &resolver->algorithms);
7661 if (result != ISC_R_SUCCESS)
7666 mask = 1 << (alg%8);
7668 result = dns_rbt_addnode(resolver->algorithms, name, &node);
7670 if (result == ISC_R_SUCCESS || result == ISC_R_EXISTS) {
7671 algorithms = node->data;
7672 if (algorithms == NULL || len > *algorithms) {
7673 new = isc_mem_get(resolver->mctx, len);
7675 result = ISC_R_NOMEMORY;
7678 memset(new, 0, len);
7679 if (algorithms != NULL)
7680 memcpy(new, algorithms, *algorithms);
7684 if (algorithms != NULL)
7685 isc_mem_put(resolver->mctx, algorithms,
7688 algorithms[len-1] |= mask;
7690 result = ISC_R_SUCCESS;
7693 RWUNLOCK(&resolver->alglock, isc_rwlocktype_write);
7699 dns_resolver_algorithm_supported(dns_resolver_t *resolver, dns_name_t *name,
7702 unsigned int len, mask;
7703 unsigned char *algorithms;
7705 isc_result_t result;
7706 isc_boolean_t found = ISC_FALSE;
7708 REQUIRE(VALID_RESOLVER(resolver));
7711 RWLOCK(&resolver->alglock, isc_rwlocktype_read);
7713 if (resolver->algorithms == NULL)
7715 result = dns_rbt_findname(resolver->algorithms, name, 0, NULL, &data);
7716 if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
7718 mask = 1 << (alg%8);
7720 if (len <= *algorithms && (algorithms[len-1] & mask) != 0)
7725 RWUNLOCK(&resolver->alglock, isc_rwlocktype_read);
7729 return (dst_algorithm_supported(alg));
7733 dns_resolver_digest_supported(dns_resolver_t *resolver, unsigned int digest) {
7736 return (dns_ds_digest_supported(digest));
7740 dns_resolver_resetmustbesecure(dns_resolver_t *resolver) {
7742 REQUIRE(VALID_RESOLVER(resolver));
7745 RWLOCK(&resolver->mbslock, isc_rwlocktype_write);
7747 if (resolver->mustbesecure != NULL)
7748 dns_rbt_destroy(&resolver->mustbesecure);
7750 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write);
7754 static isc_boolean_t yes = ISC_TRUE, no = ISC_FALSE;
7757 dns_resolver_setmustbesecure(dns_resolver_t *resolver, dns_name_t *name,
7758 isc_boolean_t value)
7760 isc_result_t result;
7762 REQUIRE(VALID_RESOLVER(resolver));
7765 RWLOCK(&resolver->mbslock, isc_rwlocktype_write);
7767 if (resolver->mustbesecure == NULL) {
7768 result = dns_rbt_create(resolver->mctx, NULL, NULL,
7769 &resolver->mustbesecure);
7770 if (result != ISC_R_SUCCESS)
7773 result = dns_rbt_addname(resolver->mustbesecure, name,
7774 value ? &yes : &no);
7777 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write);
7783 dns_resolver_getmustbesecure(dns_resolver_t *resolver, dns_name_t *name) {
7785 isc_boolean_t value = ISC_FALSE;
7786 isc_result_t result;
7788 REQUIRE(VALID_RESOLVER(resolver));
7791 RWLOCK(&resolver->mbslock, isc_rwlocktype_read);
7793 if (resolver->mustbesecure == NULL)
7795 result = dns_rbt_findname(resolver->mustbesecure, name, 0, NULL, &data);
7796 if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
7797 value = *(isc_boolean_t*)data;
7800 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_read);
7806 dns_resolver_getclientsperquery(dns_resolver_t *resolver, isc_uint32_t *cur,
7807 isc_uint32_t *min, isc_uint32_t *max)
7809 REQUIRE(VALID_RESOLVER(resolver));
7811 LOCK(&resolver->lock);
7813 *cur = resolver->spillat;
7815 *min = resolver->spillatmin;
7817 *max = resolver->spillatmax;
7818 UNLOCK(&resolver->lock);
7822 dns_resolver_setclientsperquery(dns_resolver_t *resolver, isc_uint32_t min,
7825 REQUIRE(VALID_RESOLVER(resolver));
7827 LOCK(&resolver->lock);
7828 resolver->spillatmin = resolver->spillat = min;
7829 resolver->spillatmax = max;
7830 UNLOCK(&resolver->lock);
7834 dns_resolver_getzeronosoattl(dns_resolver_t *resolver) {
7835 REQUIRE(VALID_RESOLVER(resolver));
7837 return (resolver->zero_no_soa_ttl);
7841 dns_resolver_setzeronosoattl(dns_resolver_t *resolver, isc_boolean_t state) {
7842 REQUIRE(VALID_RESOLVER(resolver));
7844 resolver->zero_no_soa_ttl = state;
7848 dns_resolver_getoptions(dns_resolver_t *resolver) {
7849 REQUIRE(VALID_RESOLVER(resolver));
7851 return (resolver->options);