bind - Upgraded vendor branch to 9.5.2-P1
[dragonfly.git] / contrib / bind-9.5.2 / lib / dns / resolver.c
CommitLineData
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1/*
2 * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003 Internet Software Consortium.
4 *
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.
8 *
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.
16 */
17
c4067435 18/* $Id: resolver.c,v 1.355.12.44.2.1 2009/11/18 23:41:18 marka Exp $ */
bbbf71a3
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19
20/*! \file */
21
22#include <config.h>
23
24#include <isc/platform.h>
25#include <isc/print.h>
26#include <isc/string.h>
27#include <isc/random.h>
28#include <isc/task.h>
29#include <isc/stats.h>
30#include <isc/timer.h>
31#include <isc/util.h>
32
33#include <dns/acl.h>
34#include <dns/adb.h>
35#include <dns/cache.h>
36#include <dns/db.h>
37#include <dns/dispatch.h>
38#include <dns/ds.h>
39#include <dns/events.h>
40#include <dns/forward.h>
41#include <dns/keytable.h>
42#include <dns/log.h>
43#include <dns/message.h>
44#include <dns/ncache.h>
45#include <dns/opcode.h>
46#include <dns/peer.h>
47#include <dns/rbt.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>
59#include <dns/tsig.h>
60#include <dns/validator.h>
61
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, \
67 ISC_LOG_DEBUG(3), \
68 "res %p: %s", res, (m))
69#define RRTRACE(r, m) isc_log_write(dns_lctx, \
70 DNS_LOGCATEGORY_RESOLVER, \
71 DNS_LOGMODULE_RESOLVER, \
72 ISC_LOG_DEBUG(3), \
73 "res %p: %s", (r), (m))
74#define FCTXTRACE(m) isc_log_write(dns_lctx, \
75 DNS_LOGCATEGORY_RESOLVER, \
76 DNS_LOGMODULE_RESOLVER, \
77 ISC_LOG_DEBUG(3), \
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, \
83 ISC_LOG_DEBUG(3), \
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, \
89 ISC_LOG_DEBUG(3), \
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, \
96 ISC_LOG_DEBUG(3), \
97 "resquery %p (fctx %p(%s)): %s", \
98 query, query->fctx, \
99 query->fctx->info, (m))
100#else
101#define RTRACE(m)
102#define RRTRACE(r, m)
103#define FCTXTRACE(m)
104#define FTRACE(m)
105#define QTRACE(m)
106#endif
107
108/*%
109 * Maximum EDNS0 input packet size.
110 */
111#define RECV_BUFFER_SIZE 4096 /* XXXRTH Constant. */
112
113/*%
114 * This defines the maximum number of timeouts we will permit before we
115 * disable EDNS0 on the query.
116 */
117#define MAX_EDNS0_TIMEOUTS 3
118
119typedef struct fetchctx fetchctx_t;
120
121typedef struct query {
122 /* Locked by task event serialization. */
123 unsigned int magic;
124 fetchctx_t * fctx;
125 isc_mem_t * mctx;
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;
131 isc_time_t start;
132 dns_messageid_t id;
133 dns_dispentry_t * dispentry;
134 ISC_LINK(struct query) link;
135 isc_buffer_t buffer;
136 isc_buffer_t *tsig;
137 dns_tsigkey_t *tsigkey;
138 unsigned int options;
139 unsigned int attributes;
140 unsigned int sends;
141 unsigned int connects;
142 unsigned char data[512];
143} resquery_t;
144
145#define QUERY_MAGIC ISC_MAGIC('Q', '!', '!', '!')
146#define VALID_QUERY(query) ISC_MAGIC_VALID(query, QUERY_MAGIC)
147
148#define RESQUERY_ATTR_CANCELED 0x02
149
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)
154
155typedef enum {
156 fetchstate_init = 0, /*%< Start event has not run yet. */
157 fetchstate_active,
158 fetchstate_done /*%< FETCHDONE events posted. */
159} fetchstate;
160
161typedef enum {
162 badns_unreachable = 0,
163 badns_response,
164 badns_validation
165} badnstype_t;
166
167struct fetchctx {
168 /*% Not locked. */
169 unsigned int magic;
170 dns_resolver_t * res;
171 dns_name_t name;
172 dns_rdatatype_t type;
173 unsigned int options;
174 unsigned int bucketnum;
175 char * info;
176 /*% Locked by appropriate bucket lock. */
177 fetchstate state;
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. */
186 dns_name_t domain;
187 dns_rdataset_t nameservers;
188 unsigned int attributes;
189 isc_timer_t * timer;
190 isc_time_t expires;
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;
208 dns_db_t * cache;
209 dns_adb_t * adb;
210
211 /*%
212 * The number of events we're waiting for.
213 */
214 unsigned int pending;
215
216 /*%
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".
223 */
224 unsigned int restarts;
225
226 /*%
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.
230 */
231 unsigned int timeouts;
232
233 /*%
234 * Look aside state for DS lookups.
235 */
236 dns_name_t nsname;
237 dns_fetch_t * nsfetch;
238 dns_rdataset_t nsrrset;
239
240 /*%
241 * Number of queries that reference this context.
242 */
243 unsigned int nqueries;
244
245 /*%
246 * The reason to print when logging a successful
247 * response to a query.
248 */
249 const char * reason;
250
251 /*%
252 * Fetch-local statistics for detailed logging.
253 */
254 isc_result_t result; /*%< fetch result */
255 isc_result_t vresult; /*%< validation result */
256 int exitline;
257 isc_time_t start;
258 isc_uint64_t duration;
259 isc_boolean_t logged;
260 unsigned int querysent;
261 unsigned int referrals;
262 unsigned int lamecount;
263 unsigned int neterr;
264 unsigned int badresp;
265 unsigned int adberr;
266 unsigned int findfail;
267 unsigned int valfail;
268 isc_boolean_t timeout;
269};
270
271#define FCTX_MAGIC ISC_MAGIC('F', '!', '!', '!')
272#define VALID_FCTX(fctx) ISC_MAGIC_VALID(fctx, FCTX_MAGIC)
273
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
283
284#define HAVE_ANSWER(f) (((f)->attributes & FCTX_ATTR_HAVEANSWER) != \
285 0)
286#define GLUING(f) (((f)->attributes & FCTX_ATTR_GLUING) != \
287 0)
288#define ADDRWAIT(f) (((f)->attributes & FCTX_ATTR_ADDRWAIT) != \
289 0)
290#define SHUTTINGDOWN(f) (((f)->attributes & FCTX_ATTR_SHUTTINGDOWN) \
291 != 0)
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)
297
298typedef struct {
299 dns_adbaddrinfo_t * addrinfo;
300 fetchctx_t * fctx;
301} dns_valarg_t;
302
303struct dns_fetch {
304 unsigned int magic;
305 fetchctx_t * private;
306};
307
308#define DNS_FETCH_MAGIC ISC_MAGIC('F', 't', 'c', 'h')
309#define DNS_FETCH_VALID(fetch) ISC_MAGIC_VALID(fetch, DNS_FETCH_MAGIC)
310
311typedef struct fctxbucket {
312 isc_task_t * task;
313 isc_mutex_t lock;
314 ISC_LIST(fetchctx_t) fctxs;
315 isc_boolean_t exiting;
316 isc_mem_t * mctx;
317} fctxbucket_t;
318
319typedef struct alternate {
320 isc_boolean_t isaddress;
321 union {
322 isc_sockaddr_t addr;
323 struct {
324 dns_name_t name;
325 in_port_t port;
326 } _n;
327 } _u;
328 ISC_LINK(struct alternate) link;
329} alternate_t;
330
331struct dns_resolver {
332 /* Unlocked. */
333 unsigned int magic;
334 isc_mem_t * mctx;
335 isc_mutex_t lock;
336 isc_mutex_t nlock;
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;
342 dns_view_t * view;
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;
350 unsigned int ndisps;
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;
356#if USE_ALGLOCK
357 isc_rwlock_t alglock;
358#endif
359 dns_rbt_t * algorithms;
360#if USE_MBSLOCK
361 isc_rwlock_t mbslock;
362#endif
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;
368
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. */
380 unsigned int nfctx;
381};
382
383#define RES_MAGIC ISC_MAGIC('R', 'e', 's', '!')
384#define VALID_RESOLVER(res) ISC_MAGIC_VALID(res, RES_MAGIC)
385
386/*%
387 * Private addrinfo flags. These must not conflict with DNS_FETCHOPT_NOEDNS0,
388 * which we also use as an addrinfo flag.
389 */
390#define FCTX_ADDRINFO_MARK 0x0001
391#define FCTX_ADDRINFO_FORWARDER 0x1000
392#define UNMARKED(a) (((a)->flags & FCTX_ADDRINFO_MARK) \
393 == 0)
394#define ISFORWARDER(a) (((a)->flags & \
395 FCTX_ADDRINFO_FORWARDER) != 0)
396
397#define NXDOMAIN(r) (((r)->attributes & DNS_RDATASETATTR_NXDOMAIN) != 0)
398
399static void destroy(dns_resolver_t *res);
400static void empty_bucket(dns_resolver_t *res);
401static isc_result_t resquery_send(resquery_t *query);
402static void resquery_response(isc_task_t *task, isc_event_t *event);
403static void resquery_connected(isc_task_t *task, isc_event_t *event);
404static void fctx_try(fetchctx_t *fctx, isc_boolean_t retrying);
405static isc_boolean_t fctx_destroy(fetchctx_t *fctx);
406static 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);
412static void validated(isc_task_t *task, isc_event_t *event);
413static void maybe_destroy(fetchctx_t *fctx);
414static void add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
415 isc_result_t reason, badnstype_t badtype);
416
417/*%
418 * Increment resolver-related statistics counters.
419 */
420static inline void
421inc_stats(dns_resolver_t *res, isc_statscounter_t counter) {
422 if (res->view->resstats != NULL)
423 isc_stats_increment(res->view->resstats, counter);
424}
425
426static isc_result_t
427valcreate(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,
430 isc_task_t *task)
431{
432 dns_validator_t *validator = NULL;
433 dns_valarg_t *valarg;
434 isc_result_t result;
435
436 valarg = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
437 sizeof(*valarg));
438 if (valarg == NULL)
439 return (ISC_R_NOMEMORY);
440
441 valarg->fctx = fctx;
442 valarg->addrinfo = addrinfo;
443
444 if (!ISC_LIST_EMPTY(fctx->validators))
445 INSIST((valoptions & DNS_VALIDATOR_DEFER) != 0);
446
447 result = dns_validator_create(fctx->res->view, name, type, rdataset,
448 sigrdataset, fctx->rmessage,
449 valoptions, task, validated, valarg,
450 &validator);
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;
456 }
457 ISC_LIST_APPEND(fctx->validators, validator, link);
458 } else
459 isc_mem_put(fctx->res->buckets[fctx->bucketnum].mctx,
460 valarg, sizeof(*valarg));
461 return (result);
462}
463
464static isc_boolean_t
465rrsig_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;
469 int order;
470 isc_result_t result;
471 unsigned int labels;
472
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,
480 &order, &labels);
481 if (namereln == dns_namereln_subdomain)
482 return (ISC_TRUE);
483 dns_rdata_reset(&rdata);
484 }
485 return (ISC_FALSE);
486}
487
488static isc_boolean_t
489fix_mustbedelegationornxdomain(dns_message_t *message, fetchctx_t *fctx) {
490 dns_name_t *name;
491 dns_name_t *domain = &fctx->domain;
492 dns_rdataset_t *rdataset;
493 dns_rdatatype_t type;
494 isc_result_t result;
495 isc_boolean_t keep_auth = ISC_FALSE;
496
497 if (message->rcode == dns_rcode_nxdomain)
498 return (ISC_FALSE);
499
500 /*
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.
504 *
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.
521 *
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
524 * zone.
525 *
526 * Also accept answers with RRSIG records from the child zone.
527 * Direct queries for RRSIG records should not be answered from
528 * the parent zone.
529 */
530
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) {
540 name = NULL;
541 dns_message_currentname(message, DNS_SECTION_ANSWER,
542 &name);
543 for (rdataset = ISC_LIST_HEAD(name->list);
544 rdataset != NULL;
545 rdataset = ISC_LIST_NEXT(rdataset, link)) {
546 if (!dns_name_equal(name, &fctx->name))
547 continue;
548 type = rdataset->type;
549 /*
550 * RRsig from child?
551 */
552 if (type == dns_rdatatype_rrsig &&
553 rrsig_fromchildzone(fctx, rdataset))
554 return (ISC_FALSE);
555 /*
556 * Direct query for apex records or DS.
557 */
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))
563 return (ISC_FALSE);
564 /*
565 * Indirect query for apex records or DS.
566 */
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))
572 return (ISC_FALSE);
573 }
574 result = dns_message_nextname(message,
575 DNS_SECTION_ANSWER);
576 }
577 }
578
579 /*
580 * A NODATA response to a DS query?
581 */
582 if (fctx->type == dns_rdatatype_ds &&
583 message->counts[DNS_SECTION_ANSWER] == 0)
584 return (ISC_FALSE);
585
586 /* Look for referral or indication of answer from child zone? */
587 if (message->counts[DNS_SECTION_AUTHORITY] == 0)
588 goto munge;
589
590 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
591 while (result == ISC_R_SUCCESS) {
592 name = NULL;
593 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
594 for (rdataset = ISC_LIST_HEAD(name->list);
595 rdataset != NULL;
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;
601
602 if (type != dns_rdatatype_ns &&
603 type != dns_rdatatype_soa &&
604 type != dns_rdatatype_rrsig)
605 continue;
606
607 if (type == dns_rdatatype_rrsig) {
608 if (rrsig_fromchildzone(fctx, rdataset))
609 return (ISC_FALSE);
610 else
611 continue;
612 }
613
614 /* NS or SOA records. */
615 if (dns_name_equal(name, domain)) {
616 /*
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
623 * case.
624 */
625 if (message->counts[DNS_SECTION_ANSWER] == 0 &&
626 fctx->type == dns_rdatatype_any)
627 return (ISC_FALSE);
628 } else if (dns_name_issubdomain(name, domain)) {
629 /* Referral or answer from child zone. */
630 return (ISC_FALSE);
631 }
632 }
633 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
634 }
635
636 munge:
637 message->rcode = dns_rcode_nxdomain;
638 message->counts[DNS_SECTION_ANSWER] = 0;
639 if (!keep_auth)
640 message->counts[DNS_SECTION_AUTHORITY] = 0;
641 message->counts[DNS_SECTION_ADDITIONAL] = 0;
642 return (ISC_TRUE);
643}
644
645static inline isc_result_t
646fctx_starttimer(fetchctx_t *fctx) {
647 /*
648 * Start the lifetime timer for fctx.
649 *
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.
653 */
654 return (isc_timer_reset(fctx->timer, isc_timertype_once,
655 &fctx->expires, NULL, ISC_TRUE));
656}
657
658static inline void
659fctx_stoptimer(fetchctx_t *fctx) {
660 isc_result_t result;
661
662 /*
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.
667 */
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));
674 }
675}
676
677
678static inline isc_result_t
679fctx_startidletimer(fetchctx_t *fctx, isc_interval_t *interval) {
680 /*
681 * Start the idle timer for fctx. The lifetime timer continues
682 * to be in effect.
683 */
684 return (isc_timer_reset(fctx->timer, isc_timertype_once,
685 &fctx->expires, interval, ISC_FALSE));
686}
687
688/*
689 * Stopping the idle timer is equivalent to calling fctx_starttimer(), but
690 * we use fctx_stopidletimer for readability in the code below.
691 */
692#define fctx_stopidletimer fctx_starttimer
693
694
695static inline void
696resquery_destroy(resquery_t **queryp) {
697 resquery_t *query;
698
699 REQUIRE(queryp != NULL);
700 query = *queryp;
701 REQUIRE(!ISC_LINK_LINKED(query, link));
702
703 INSIST(query->tcpsocket == NULL);
704
705 query->fctx->nqueries--;
706 if (SHUTTINGDOWN(query->fctx))
707 maybe_destroy(query->fctx); /* Locks bucket. */
708 query->magic = 0;
709 isc_mem_put(query->mctx, query, sizeof(*query));
710 *queryp = NULL;
711}
712
713static void
714fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp,
715 isc_time_t *finish, isc_boolean_t no_response)
716{
717 fetchctx_t *fctx;
718 resquery_t *query;
719 unsigned int rtt, rttms;
720 unsigned int factor;
721 dns_adbfind_t *find;
722 dns_adbaddrinfo_t *addrinfo;
723 isc_socket_t *socket;
724
725 query = *queryp;
726 fctx = query->fctx;
727
728 FCTXTRACE("cancelquery");
729
730 REQUIRE(!RESQUERY_CANCELED(query));
731
732 query->attributes |= RESQUERY_ATTR_CANCELED;
733
734 /*
735 * Should we update the RTT?
736 */
737 if (finish != NULL || no_response) {
738 if (finish != NULL) {
739 /*
740 * We have both the start and finish times for this
741 * packet, so we can compute a real RTT.
742 */
743 rtt = (unsigned int)isc_time_microdiff(finish,
744 &query->start);
745 factor = DNS_ADB_RTTADJDEFAULT;
746
747 rttms = rtt / 1000;
748 if (rttms < DNS_RESOLVER_QRYRTTCLASS0) {
749 inc_stats(fctx->res,
750 dns_resstatscounter_queryrtt0);
751 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS1) {
752 inc_stats(fctx->res,
753 dns_resstatscounter_queryrtt1);
754 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS2) {
755 inc_stats(fctx->res,
756 dns_resstatscounter_queryrtt2);
757 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS3) {
758 inc_stats(fctx->res,
759 dns_resstatscounter_queryrtt3);
760 } else if (rttms < DNS_RESOLVER_QRYRTTCLASS4) {
761 inc_stats(fctx->res,
762 dns_resstatscounter_queryrtt4);
763 } else {
764 inc_stats(fctx->res,
765 dns_resstatscounter_queryrtt5);
766 }
767 } else {
768 /*
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.
772 */
773 INSIST(no_response);
774 rtt = query->addrinfo->srtt + 200000;
775 if (rtt > 10000000)
776 rtt = 10000000;
777 /*
778 * Replace the current RTT with our value.
779 */
780 factor = DNS_ADB_RTTADJREPLACE;
781 }
782 dns_adb_adjustsrtt(fctx->adb, query->addrinfo, rtt, factor);
783 }
784
785 /*
786 * Age RTTs of servers not tried.
787 */
788 factor = DNS_ADB_RTTADJAGE;
789 if (finish != NULL)
790 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
791 addrinfo != NULL;
792 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
793 if (UNMARKED(addrinfo))
794 dns_adb_adjustsrtt(fctx->adb, addrinfo,
795 0, factor);
796
797 if (finish != NULL && TRIEDFIND(fctx))
798 for (find = ISC_LIST_HEAD(fctx->finds);
799 find != NULL;
800 find = ISC_LIST_NEXT(find, publink))
801 for (addrinfo = ISC_LIST_HEAD(find->list);
802 addrinfo != NULL;
803 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
804 if (UNMARKED(addrinfo))
805 dns_adb_adjustsrtt(fctx->adb, addrinfo,
806 0, factor);
807
808 if (finish != NULL && TRIEDALT(fctx)) {
809 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
810 addrinfo != NULL;
811 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
812 if (UNMARKED(addrinfo))
813 dns_adb_adjustsrtt(fctx->adb, addrinfo,
814 0, factor);
815 for (find = ISC_LIST_HEAD(fctx->altfinds);
816 find != NULL;
817 find = ISC_LIST_NEXT(find, publink))
818 for (addrinfo = ISC_LIST_HEAD(find->list);
819 addrinfo != NULL;
820 addrinfo = ISC_LIST_NEXT(addrinfo, publink))
821 if (UNMARKED(addrinfo))
822 dns_adb_adjustsrtt(fctx->adb, addrinfo,
823 0, factor);
824 }
825
826 /*
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.
831 */
832 if (RESQUERY_CONNECTING(query)) {
833 /*
834 * Cancel the connect.
835 */
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);
842 if (socket != NULL)
843 isc_socket_cancel(socket, NULL,
844 ISC_SOCKCANCEL_CONNECT);
845 }
846 } else if (RESQUERY_SENDING(query)) {
847 /*
848 * Cancel the pending send.
849 */
850 if (query->exclusivesocket && query->dispentry != NULL)
851 socket = dns_dispatch_getentrysocket(query->dispentry);
852 else
853 socket = dns_dispatch_getsocket(query->dispatch);
854 if (socket != NULL)
855 isc_socket_cancel(socket, NULL, ISC_SOCKCANCEL_SEND);
856 }
857
858 if (query->dispentry != NULL)
859 dns_dispatch_removeresponse(&query->dispentry, deventp);
860
861 ISC_LIST_UNLINK(fctx->queries, query, link);
862
863 if (query->tsig != NULL)
864 isc_buffer_free(&query->tsig);
865
866 if (query->tsigkey != NULL)
867 dns_tsigkey_detach(&query->tsigkey);
868
869 if (query->dispatch != NULL)
870 dns_dispatch_detach(&query->dispatch);
871
872 if (! (RESQUERY_CONNECTING(query) || RESQUERY_SENDING(query)))
873 /*
874 * It's safe to destroy the query now.
875 */
876 resquery_destroy(&query);
877}
878
879static void
880fctx_cancelqueries(fetchctx_t *fctx, isc_boolean_t no_response) {
881 resquery_t *query, *next_query;
882
883 FCTXTRACE("cancelqueries");
884
885 for (query = ISC_LIST_HEAD(fctx->queries);
886 query != NULL;
887 query = next_query) {
888 next_query = ISC_LIST_NEXT(query, link);
889 fctx_cancelquery(&query, NULL, NULL, no_response);
890 }
891}
892
893static void
894fctx_cleanupfinds(fetchctx_t *fctx) {
895 dns_adbfind_t *find, *next_find;
896
897 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
898
899 for (find = ISC_LIST_HEAD(fctx->finds);
900 find != NULL;
901 find = next_find) {
902 next_find = ISC_LIST_NEXT(find, publink);
903 ISC_LIST_UNLINK(fctx->finds, find, publink);
904 dns_adb_destroyfind(&find);
905 }
906 fctx->find = NULL;
907}
908
909static void
910fctx_cleanupaltfinds(fetchctx_t *fctx) {
911 dns_adbfind_t *find, *next_find;
912
913 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
914
915 for (find = ISC_LIST_HEAD(fctx->altfinds);
916 find != NULL;
917 find = next_find) {
918 next_find = ISC_LIST_NEXT(find, publink);
919 ISC_LIST_UNLINK(fctx->altfinds, find, publink);
920 dns_adb_destroyfind(&find);
921 }
922 fctx->altfind = NULL;
923}
924
925static void
926fctx_cleanupforwaddrs(fetchctx_t *fctx) {
927 dns_adbaddrinfo_t *addr, *next_addr;
928
929 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
930
931 for (addr = ISC_LIST_HEAD(fctx->forwaddrs);
932 addr != NULL;
933 addr = next_addr) {
934 next_addr = ISC_LIST_NEXT(addr, publink);
935 ISC_LIST_UNLINK(fctx->forwaddrs, addr, publink);
936 dns_adb_freeaddrinfo(fctx->adb, &addr);
937 }
938}
939
940static void
941fctx_cleanupaltaddrs(fetchctx_t *fctx) {
942 dns_adbaddrinfo_t *addr, *next_addr;
943
944 REQUIRE(ISC_LIST_EMPTY(fctx->queries));
945
946 for (addr = ISC_LIST_HEAD(fctx->altaddrs);
947 addr != NULL;
948 addr = next_addr) {
949 next_addr = ISC_LIST_NEXT(addr, publink);
950 ISC_LIST_UNLINK(fctx->altaddrs, addr, publink);
951 dns_adb_freeaddrinfo(fctx->adb, &addr);
952 }
953}
954
955static inline void
956fctx_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);
964}
965
966static inline void
967fctx_sendevents(fetchctx_t *fctx, isc_result_t result, int line) {
968 dns_fetchevent_t *event, *next_event;
969 isc_task_t *task;
970 unsigned int count = 0;
971 isc_interval_t i;
972 isc_boolean_t logit = ISC_FALSE;
973 isc_time_t now;
974 unsigned int old_spillat;
975 unsigned int new_spillat = 0; /* initialized to silence
976 compiler warnings */
977
978 /*
979 * Caller must be holding the appropriate bucket lock.
980 */
981 REQUIRE(fctx->state == fetchstate_done);
982
983 FCTXTRACE("sendevents");
984
985 /*
986 * Keep some record of fetch result for logging later (if required).
987 */
988 fctx->result = result;
989 fctx->exitline = line;
990 TIME_NOW(&now);
991 fctx->duration = isc_time_microdiff(&now, &fctx->start);
992
993 for (event = ISC_LIST_HEAD(fctx->events);
994 event != NULL;
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;
1002
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);
1008
1009 /*
1010 * Negative results must be indicated in event->result.
1011 */
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);
1016 }
1017
1018 isc_task_sendanddetach(&task, ISC_EVENT_PTR(&event));
1019 count++;
1020 }
1021
1022 if ((fctx->attributes & FCTX_ATTR_HAVEANSWER) != 0 &&
1023 fctx->spilled &&
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) {
1034 logit = ISC_TRUE;
1035 }
1036 isc_interval_set(&i, 20 * 60, 0);
1037 result = isc_timer_reset(fctx->res->spillattimer,
1038 isc_timertype_ticker, NULL,
1039 &i, ISC_TRUE);
1040 RUNTIME_CHECK(result == ISC_R_SUCCESS);
1041 }
1042 UNLOCK(&fctx->res->lock);
1043 if (logit)
1044 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
1045 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
1046 "clients-per-query increased to %u",
1047 new_spillat);
1048 }
1049}
1050
1051static inline void
1052log_edns(fetchctx_t *fctx) {
1053 char domainbuf[DNS_NAME_FORMATSIZE];
1054
1055 if (fctx->reason == NULL)
1056 return;
1057
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);
1063
1064 fctx->reason = NULL;
1065}
1066
1067static void
1068fctx_done(fetchctx_t *fctx, isc_result_t result, int line) {
1069 dns_resolver_t *res;
1070 isc_boolean_t no_response;
1071
1072 REQUIRE(line >= 0);
1073
1074 FCTXTRACE("done");
1075
1076 res = fctx->res;
1077
1078 if (result == ISC_R_SUCCESS) {
1079 /*%
1080 * Log any deferred EDNS timeout messages.
1081 */
1082 log_edns(fctx);
1083 no_response = ISC_TRUE;
1084 } else
1085 no_response = ISC_FALSE;
1086
1087 fctx->reason = NULL;
1088 fctx_stopeverything(fctx, no_response);
1089
1090 LOCK(&res->buckets[fctx->bucketnum].lock);
1091
1092 fctx->state = fetchstate_done;
1093 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
1094 fctx_sendevents(fctx, result, line);
1095
1096 UNLOCK(&res->buckets[fctx->bucketnum].lock);
1097}
1098
1099static void
1100process_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;
1104 fetchctx_t *fctx;
1105
1106 fctx = query->fctx;
1107
1108 if (RESQUERY_CANCELED(query)) {
1109 if (query->sends == 0 && query->connects == 0) {
1110 /*
1111 * This query was canceled while the
1112 * isc_socket_sendto/connect() was in progress.
1113 */
1114 if (query->tcpsocket != NULL)
1115 isc_socket_detach(&query->tcpsocket);
1116 resquery_destroy(&query);
1117 }
1118 } else {
1119 switch (sevent->result) {
1120 case ISC_R_SUCCESS:
1121 break;
1122
1123 case ISC_R_HOSTUNREACH:
1124 case ISC_R_NETUNREACH:
1125 case ISC_R_NOPERM:
1126 case ISC_R_ADDRNOTAVAIL:
1127 case ISC_R_CONNREFUSED:
1128
1129 /*
1130 * No route to remote.
1131 */
1132 add_bad(fctx, query->addrinfo, sevent->result,
1133 badns_unreachable);
1134 fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
1135 retry = ISC_TRUE;
1136 break;
1137
1138 default:
1139 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
1140 break;
1141 }
1142 }
1143
1144 isc_event_free(&event);
1145
1146 if (retry) {
1147 /*
1148 * Behave as if the idle timer has expired. For TCP
1149 * this may not actually reflect the latest timer.
1150 */
1151 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
1152 result = fctx_stopidletimer(fctx);
1153 if (result != ISC_R_SUCCESS)
1154 fctx_done(fctx, result, __LINE__);
1155 else
1156 fctx_try(fctx, ISC_TRUE);
1157 }
1158}
1159
1160static void
1161resquery_udpconnected(isc_task_t *task, isc_event_t *event) {
1162 resquery_t *query = event->ev_arg;
1163
1164 REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
1165
1166 QTRACE("udpconnected");
1167
1168 UNUSED(task);
1169
1170 INSIST(RESQUERY_CONNECTING(query));
1171
1172 query->connects--;
1173
1174 process_sendevent(query, event);
1175}
1176
1177static void
1178resquery_senddone(isc_task_t *task, isc_event_t *event) {
1179 resquery_t *query = event->ev_arg;
1180
1181 REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);
1182
1183 QTRACE("senddone");
1184
1185 /*
1186 * XXXRTH
1187 *
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!
1191 */
1192
1193 UNUSED(task);
1194
1195 INSIST(RESQUERY_SENDING(query));
1196
1197 query->sends--;
1198
1199 process_sendevent(query, event);
1200}
1201
1202static inline isc_result_t
1203fctx_addopt(dns_message_t *message, unsigned int version,
1204 isc_uint16_t udpsize, isc_boolean_t request_nsid)
1205{
1206 dns_rdataset_t *rdataset;
1207 dns_rdatalist_t *rdatalist;
1208 dns_rdata_t *rdata;
1209 isc_result_t result;
1210
1211 rdatalist = NULL;
1212 result = dns_message_gettemprdatalist(message, &rdatalist);
1213 if (result != ISC_R_SUCCESS)
1214 return (result);
1215 rdata = NULL;
1216 result = dns_message_gettemprdata(message, &rdata);
1217 if (result != ISC_R_SUCCESS)
1218 return (result);
1219 rdataset = NULL;
1220 result = dns_message_gettemprdataset(message, &rdataset);
1221 if (result != ISC_R_SUCCESS)
1222 return (result);
1223 dns_rdataset_init(rdataset);
1224
1225 rdatalist->type = dns_rdatatype_opt;
1226 rdatalist->covers = 0;
1227
1228 /*
1229 * Set Maximum UDP buffer size.
1230 */
1231 rdatalist->rdclass = udpsize;
1232
1233 /*
1234 * Set EXTENDED-RCODE and Z to 0, DO to 1.
1235 */
1236 rdatalist->ttl = (version << 16);
1237 rdatalist->ttl |= DNS_MESSAGEEXTFLAG_DO;
1238
1239 /*
1240 * Set EDNS options if applicable
1241 */
1242 if (request_nsid) {
1243 /* Send empty NSID option (RFC5001) */
1244 unsigned char data[4];
1245 isc_buffer_t buf;
1246
1247 isc_buffer_init(&buf, data, sizeof(data));
1248 isc_buffer_putuint16(&buf, DNS_OPT_NSID);
1249 isc_buffer_putuint16(&buf, 0);
1250 rdata->data = data;
1251 rdata->length = sizeof(data);
1252 } else {
1253 rdata->data = NULL;
1254 rdata->length = 0;
1255 }
1256
1257 rdata->rdclass = rdatalist->rdclass;
1258 rdata->type = rdatalist->type;
1259 rdata->flags = 0;
1260
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);
1264
1265 return (dns_message_setopt(message, rdataset));
1266}
1267
1268static inline void
1269fctx_setretryinterval(fetchctx_t *fctx, unsigned int rtt) {
1270 unsigned int seconds;
1271 unsigned int us;
1272
1273 /*
1274 * We retry every .8 seconds the first two times through the address
1275 * list, and then we do exponential back-off.
1276 */
1277 if (fctx->restarts < 3)
1278 us = 800000;
1279 else
1280 us = (800000 << (fctx->restarts - 2));
1281
1282 /*
1283 * Double the round-trip time.
1284 */
1285 rtt *= 2;
1286
1287 /*
1288 * Always wait for at least the doubled round-trip time.
1289 */
1290 if (us < rtt)
1291 us = rtt;
1292
1293 /*
1294 * But don't ever wait for more than 10 seconds.
1295 */
1296 if (us > 10000000)
1297 us = 10000000;
1298
1299 seconds = us / 1000000;
1300 us -= seconds * 1000000;
1301 isc_interval_set(&fctx->interval, seconds, us * 1000);
1302}
1303
1304static isc_result_t
1305fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
1306 unsigned int options)
1307{
1308 dns_resolver_t *res;
1309 isc_task_t *task;
1310 isc_result_t result;
1311 resquery_t *query;
1312 isc_sockaddr_t addr;
1313 isc_boolean_t have_addr = ISC_FALSE;
1314
1315 FCTXTRACE("query");
1316
1317 res = fctx->res;
1318 task = res->buckets[fctx->bucketnum].task;
1319
1320 fctx_setretryinterval(fctx, addrinfo->srtt);
1321 result = fctx_startidletimer(fctx, &fctx->interval);
1322 if (result != ISC_R_SUCCESS)
1323 return (result);
1324
1325 INSIST(ISC_LIST_EMPTY(fctx->validators));
1326
1327 dns_message_reset(fctx->rmessage, DNS_MESSAGE_INTENTPARSE);
1328
1329 query = isc_mem_get(res->buckets[fctx->bucketnum].mctx,
1330 sizeof(*query));
1331 if (query == NULL) {
1332 result = ISC_R_NOMEMORY;
1333 goto stop_idle_timer;
1334 }
1335 query->mctx = res->buckets[fctx->bucketnum].mctx;
1336 query->options = options;
1337 query->attributes = 0;
1338 query->sends = 0;
1339 query->connects = 0;
1340 /*
1341 * Note that the caller MUST guarantee that 'addrinfo' will remain
1342 * valid until this query is canceled.
1343 */
1344 query->addrinfo = addrinfo;
1345 TIME_NOW(&query->start);
1346
1347 /*
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
1350 * shared dispatch.
1351 */
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,
1361 &dstip, &peer);
1362 if (result == ISC_R_SUCCESS) {
1363 result = dns_peer_getquerysource(peer, &addr);
1364 if (result == ISC_R_SUCCESS)
1365 have_addr = ISC_TRUE;
1366 }
1367 }
1368
1369 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1370 int pf;
1371
1372 pf = isc_sockaddr_pf(&addrinfo->sockaddr);
1373 if (!have_addr) {
1374 switch (pf) {
1375 case PF_INET:
1376 result =
1377 dns_dispatch_getlocaladdress(res->dispatchv4,
1378 &addr);
1379 break;
1380 case PF_INET6:
1381 result =
1382 dns_dispatch_getlocaladdress(res->dispatchv6,
1383 &addr);
1384 break;
1385 default:
1386 result = ISC_R_NOTIMPLEMENTED;
1387 break;
1388 }
1389 if (result != ISC_R_SUCCESS)
1390 goto cleanup_query;
1391 }
1392 isc_sockaddr_setport(&addr, 0);
1393
1394 result = isc_socket_create(res->socketmgr, pf,
1395 isc_sockettype_tcp,
1396 &query->tcpsocket);
1397 if (result != ISC_R_SUCCESS)
1398 goto cleanup_query;
1399
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;
1404#endif
1405
1406 /*
1407 * A dispatch will be created once the connect succeeds.
1408 */
1409 } else {
1410 if (have_addr) {
1411 unsigned int attrs, attrmask;
1412 attrs = DNS_DISPATCHATTR_UDP;
1413 switch (isc_sockaddr_pf(&addr)) {
1414 case AF_INET:
1415 attrs |= DNS_DISPATCHATTR_IPV4;
1416 break;
1417 case AF_INET6:
1418 attrs |= DNS_DISPATCHATTR_IPV6;
1419 break;
1420 default:
1421 result = ISC_R_NOTIMPLEMENTED;
1422 goto cleanup_query;
1423 }
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,
1429 res->socketmgr,
1430 res->taskmgr, &addr,
1431 4096, 1000, 32768, 16411,
1432 16433, attrs, attrmask,
1433 &query->dispatch);
1434 if (result != ISC_R_SUCCESS)
1435 goto cleanup_query;
1436 } else {
1437 switch (isc_sockaddr_pf(&addrinfo->sockaddr)) {
1438 case PF_INET:
1439 dns_dispatch_attach(res->dispatchv4,
1440 &query->dispatch);
1441 query->exclusivesocket = res->exclusivev4;
1442 break;
1443 case PF_INET6:
1444 dns_dispatch_attach(res->dispatchv6,
1445 &query->dispatch);
1446 query->exclusivesocket = res->exclusivev6;
1447 break;
1448 default:
1449 result = ISC_R_NOTIMPLEMENTED;
1450 goto cleanup_query;
1451 }
1452 }
1453 /*
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.
1459 */
1460 INSIST(query->dispatch != NULL);
1461 }
1462
1463 query->dispentry = NULL;
1464 query->fctx = fctx;
1465 query->tsig = NULL;
1466 query->tsigkey = NULL;
1467 ISC_LINK_INIT(query, link);
1468 query->magic = QUERY_MAGIC;
1469
1470 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1471 /*
1472 * Connect to the remote server.
1473 *
1474 * XXXRTH Should we attach to the socket?
1475 */
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;
1481 query->connects++;
1482 QTRACE("connecting via TCP");
1483 } else {
1484 result = resquery_send(query);
1485 if (result != ISC_R_SUCCESS)
1486 goto cleanup_dispatch;
1487 }
1488 fctx->querysent++;
1489
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);
1494 else
1495 inc_stats(res, dns_resstatscounter_queryv6);
1496 if (res->view->resquerystats != NULL)
1497 dns_rdatatypestats_increment(res->view->resquerystats,
1498 fctx->type);
1499
1500 return (ISC_R_SUCCESS);
1501
1502 cleanup_socket:
1503 isc_socket_detach(&query->tcpsocket);
1504
1505 cleanup_dispatch:
1506 if (query->dispatch != NULL)
1507 dns_dispatch_detach(&query->dispatch);
1508
1509 cleanup_query:
1510 query->magic = 0;
1511 isc_mem_put(res->buckets[fctx->bucketnum].mctx,
1512 query, sizeof(*query));
1513
1514 stop_idle_timer:
1515 RUNTIME_CHECK(fctx_stopidletimer(fctx) == ISC_R_SUCCESS);
1516
1517 return (result);
1518}
1519
1520static isc_boolean_t
1521triededns(fetchctx_t *fctx, isc_sockaddr_t *address) {
1522 isc_sockaddr_t *sa;
1523
1524 for (sa = ISC_LIST_HEAD(fctx->edns);
1525 sa != NULL;
1526 sa = ISC_LIST_NEXT(sa, link)) {
1527 if (isc_sockaddr_equal(sa, address))
1528 return (ISC_TRUE);
1529 }
1530
1531 return (ISC_FALSE);
1532}
1533
1534static void
1535add_triededns(fetchctx_t *fctx, isc_sockaddr_t *address) {
1536 isc_sockaddr_t *sa;
1537
1538 if (triededns(fctx, address))
1539 return;
1540
1541 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
1542 sizeof(*sa));
1543 if (sa == NULL)
1544 return;
1545
1546 *sa = *address;
1547 ISC_LIST_INITANDAPPEND(fctx->edns, sa, link);
1548}
1549
1550static isc_boolean_t
1551triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) {
1552 isc_sockaddr_t *sa;
1553
1554 for (sa = ISC_LIST_HEAD(fctx->edns512);
1555 sa != NULL;
1556 sa = ISC_LIST_NEXT(sa, link)) {
1557 if (isc_sockaddr_equal(sa, address))
1558 return (ISC_TRUE);
1559 }
1560
1561 return (ISC_FALSE);
1562}
1563
1564static void
1565add_triededns512(fetchctx_t *fctx, isc_sockaddr_t *address) {
1566 isc_sockaddr_t *sa;
1567
1568 if (triededns512(fctx, address))
1569 return;
1570
1571 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
1572 sizeof(*sa));
1573 if (sa == NULL)
1574 return;
1575
1576 *sa = *address;
1577 ISC_LIST_INITANDAPPEND(fctx->edns512, sa, link);
1578}
1579
1580static isc_result_t
1581resquery_send(resquery_t *query) {
1582 fetchctx_t *fctx;
1583 isc_result_t result;
1584 dns_name_t *qname = NULL;
1585 dns_rdataset_t *qrdataset = NULL;
1586 isc_region_t r;
1587 dns_resolver_t *res;
1588 isc_task_t *task;
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;
1600
1601 fctx = query->fctx;
1602 QTRACE("send");
1603
1604 res = fctx->res;
1605 task = res->buckets[fctx->bucketnum].task;
1606 address = NULL;
1607
1608 if ((query->options & DNS_FETCHOPT_TCP) != 0) {
1609 /*
1610 * Reserve space for the TCP message length.
1611 */
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;
1616 } else {
1617 isc_buffer_init(&query->buffer, query->data,
1618 sizeof(query->data));
1619 buffer = &query->buffer;
1620 }
1621
1622 result = dns_message_gettempname(fctx->qmessage, &qname);
1623 if (result != ISC_R_SUCCESS)
1624 goto cleanup_temps;
1625 result = dns_message_gettemprdataset(fctx->qmessage, &qrdataset);
1626 if (result != ISC_R_SUCCESS)
1627 goto cleanup_temps;
1628
1629 /*
1630 * Get a query id from the dispatch.
1631 */
1632 result = dns_dispatch_addresponse2(query->dispatch,
1633 &query->addrinfo->sockaddr,
1634 task,
1635 resquery_response,
1636 query,
1637 &query->id,
1638 &query->dispentry,
1639 res->socketmgr);
1640 if (result != ISC_R_SUCCESS)
1641 goto cleanup_temps;
1642
1643 fctx->qmessage->opcode = dns_opcode_query;
1644
1645 /*
1646 * Set up question.
1647 */
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);
1654 qname = NULL;
1655 qrdataset = NULL;
1656
1657 /*
1658 * Set RD if the client has requested that we do a recursive query,
1659 * or if we're sending to a forwarder.
1660 */
1661 if ((query->options & DNS_FETCHOPT_RECURSIVE) != 0 ||
1662 ISFORWARDER(query->addrinfo))
1663 fctx->qmessage->flags |= DNS_MESSAGEFLAG_RD;
1664
1665 /*
1666 * Set CD if the client says don't validate or the question is
1667 * under a secure entry point.
1668 */
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,
1673 &fctx->name,
1674 &secure_domain);
1675 if (result != ISC_R_SUCCESS)
1676 secure_domain = ISC_FALSE;
1677 if (res->view->dlv != NULL)
1678 secure_domain = ISC_TRUE;
1679 if (secure_domain)
1680 fctx->qmessage->flags |= DNS_MESSAGEFLAG_CD;
1681 }
1682
1683 /*
1684 * We don't have to set opcode because it defaults to query.
1685 */
1686 fctx->qmessage->id = query->id;
1687
1688 /*
1689 * Convert the question to wire format.
1690 */
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;
1695
1696 result = dns_message_renderbegin(fctx->qmessage, &cctx,
1697 &query->buffer);
1698 if (result != ISC_R_SUCCESS)
1699 goto cleanup_message;
1700
1701 result = dns_message_rendersection(fctx->qmessage,
1702 DNS_SECTION_QUESTION, 0);
1703 if (result != ISC_R_SUCCESS)
1704 goto cleanup_message;
1705
1706 peer = NULL;
1707 isc_netaddr_fromsockaddr(&ipaddr, &query->addrinfo->sockaddr);
1708 (void) dns_peerlist_peerbyaddr(fctx->res->view->peers, &ipaddr, &peer);
1709
1710 /*
1711 * The ADB does not know about servers with "edns no". Check this,
1712 * and then inform the ADB for future use.
1713 */
1714 if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0 &&
1715 peer != NULL &&
1716 dns_peer_getsupportedns(peer, &useedns) == ISC_R_SUCCESS &&
1717 !useedns)
1718 {
1719 query->options |= DNS_FETCHOPT_NOEDNS0;
1720 dns_adb_changeflags(fctx->adb, query->addrinfo,
1721 DNS_FETCHOPT_NOEDNS0,
1722 DNS_FETCHOPT_NOEDNS0);
1723 }
1724
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;
1728
1729 /*
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.
1732 *
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
1740 * or CD.
1741 * * packet loss / link outage.
1742 */
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";
1755 }
1756 fctx->timeout = ISC_FALSE;
1757 }
1758
1759 /*
1760 * Use EDNS0, unless the caller doesn't want it, or we know that
1761 * the remote server doesn't like it.
1762 */
1763 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
1764 if ((query->addrinfo->flags & DNS_FETCHOPT_NOEDNS0) == 0) {
1765 unsigned int version = 0; /* Default version. */
1766 unsigned int flags;
1767 isc_uint16_t udpsize = res->udpsize;
1768 isc_boolean_t reqnsid = res->view->requestnsid;
1769
1770 flags = query->addrinfo->flags;
1771 if ((flags & DNS_FETCHOPT_EDNSVERSIONSET) != 0) {
1772 version = flags & DNS_FETCHOPT_EDNSVERSIONMASK;
1773 version >>= DNS_FETCHOPT_EDNSVERSIONSHIFT;
1774 }
1775 if ((query->options & DNS_FETCHOPT_EDNS512) != 0)
1776 udpsize = 512;
1777 else if (peer != NULL)
1778 (void)dns_peer_getudpsize(peer, &udpsize);
1779
1780 /* request NSID for current view or peer? */
1781 if (peer != NULL)
1782 (void) dns_peer_getrequestnsid(peer, &reqnsid);
1783 result = fctx_addopt(fctx->qmessage, version,
1784 udpsize, reqnsid);
1785 if (reqnsid && result == ISC_R_SUCCESS) {
1786 query->options |= DNS_FETCHOPT_WANTNSID;
1787 } else if (result != ISC_R_SUCCESS) {
1788 /*
1789 * We couldn't add the OPT, but we'll press on.
1790 * We're not using EDNS0, so set the NOEDNS0
1791 * bit.
1792 */
1793 query->options |= DNS_FETCHOPT_NOEDNS0;
1794 }
1795 } else {
1796 /*
1797 * We know this server doesn't like EDNS0, so we
1798 * won't use it. Set the NOEDNS0 bit since we're
1799 * not using EDNS0.
1800 */
1801 query->options |= DNS_FETCHOPT_NOEDNS0;
1802 }
1803 }
1804
1805 /*
1806 * If we need EDNS0 to do this query and aren't using it, we lose.
1807 */
1808 if (NEEDEDNS0(fctx) && (query->options & DNS_FETCHOPT_NOEDNS0) != 0) {
1809 result = DNS_R_SERVFAIL;
1810 goto cleanup_message;
1811 }
1812
1813 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0)
1814 add_triededns(fctx, &query->addrinfo->sockaddr);
1815
1816 if ((query->options & DNS_FETCHOPT_EDNS512) != 0)
1817 add_triededns512(fctx, &query->addrinfo->sockaddr);
1818
1819 /*
1820 * Clear CD if EDNS is not in use.
1821 */
1822 if ((query->options & DNS_FETCHOPT_NOEDNS0) != 0)
1823 fctx->qmessage->flags &= ~DNS_MESSAGEFLAG_CD;
1824
1825 /*
1826 * Add TSIG record tailored to the current recipient.
1827 */
1828 result = dns_view_getpeertsig(fctx->res->view, &ipaddr, &tsigkey);
1829 if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND)
1830 goto cleanup_message;
1831
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;
1837 }
1838
1839 result = dns_message_rendersection(fctx->qmessage,
1840 DNS_SECTION_ADDITIONAL, 0);
1841 if (result != ISC_R_SUCCESS)
1842 goto cleanup_message;
1843
1844 result = dns_message_renderend(fctx->qmessage);
1845 if (result != ISC_R_SUCCESS)
1846 goto cleanup_message;
1847
1848 dns_compress_invalidate(&cctx);
1849 cleanup_cctx = ISC_FALSE;
1850
1851 if (dns_message_gettsigkey(fctx->qmessage) != NULL) {
1852 dns_tsigkey_attach(dns_message_gettsigkey(fctx->qmessage),
1853 &query->tsigkey);
1854 result = dns_message_getquerytsig(fctx->qmessage,
1855 fctx->res->mctx,
1856 &query->tsig);
1857 if (result != ISC_R_SUCCESS)
1858 goto cleanup_message;
1859 }
1860
1861 /*
1862 * If using TCP, write the length of the message at the beginning
1863 * of the buffer.
1864 */
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);
1869 }
1870
1871 /*
1872 * We're now done with the query message.
1873 */
1874 dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER);
1875
1876 if (query->exclusivesocket)
1877 socket = dns_dispatch_getentrysocket(query->dispentry);
1878 else
1879 socket = dns_dispatch_getsocket(query->dispatch);
1880 /*
1881 * Send the query!
1882 */
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,
1888 query);
1889 if (result != ISC_R_SUCCESS)
1890 goto cleanup_message;
1891 query->connects++;
1892 }
1893 }
1894 isc_buffer_usedregion(buffer, &r);
1895
1896 /*
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.
1899 */
1900 result = isc_socket_sendto(socket, &r, task, resquery_senddone,
1901 query, address, NULL);
1902 if (result != ISC_R_SUCCESS)
1903 goto cleanup_message;
1904
1905 query->sends++;
1906
1907 QTRACE("sent");
1908
1909 return (ISC_R_SUCCESS);
1910
1911 cleanup_message:
1912 if (cleanup_cctx)
1913 dns_compress_invalidate(&cctx);
1914
1915 dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER);
1916
1917 /*
1918 * Stop the dispatcher from listening.
1919 */
1920 dns_dispatch_removeresponse(&query->dispentry, NULL);
1921
1922 cleanup_temps:
1923 if (qname != NULL)
1924 dns_message_puttempname(fctx->qmessage, &qname);
1925 if (qrdataset != NULL)
1926 dns_message_puttemprdataset(fctx->qmessage, &qrdataset);
1927
1928 return (result);
1929}
1930
1931static void
1932resquery_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;
1938 unsigned int attrs;
1939 fetchctx_t *fctx;
1940
1941 REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
1942 REQUIRE(VALID_QUERY(query));
1943
1944 QTRACE("connected");
1945
1946 UNUSED(task);
1947
1948 /*
1949 * XXXRTH
1950 *
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!
1954 */
1955
1956 query->connects--;
1957 fctx = query->fctx;
1958
1959 if (RESQUERY_CANCELED(query)) {
1960 /*
1961 * This query was canceled while the connect() was in
1962 * progress.
1963 */
1964 isc_socket_detach(&query->tcpsocket);
1965 resquery_destroy(&query);
1966 } else {
1967 switch (sevent->result) {
1968 case ISC_R_SUCCESS:
1969
1970 /*
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.
1975 */
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__);
1981 break;
1982 }
1983 /*
1984 * We are connected. Create a dispatcher and
1985 * send the query.
1986 */
1987 attrs = 0;
1988 attrs |= DNS_DISPATCHATTR_TCP;
1989 attrs |= DNS_DISPATCHATTR_PRIVATE;
1990 attrs |= DNS_DISPATCHATTR_CONNECTED;
1991 if (isc_sockaddr_pf(&query->addrinfo->sockaddr) ==
1992 AF_INET)
1993 attrs |= DNS_DISPATCHATTR_IPV4;
1994 else
1995 attrs |= DNS_DISPATCHATTR_IPV6;
1996 attrs |= DNS_DISPATCHATTR_MAKEQUERY;
1997
1998 result = dns_dispatch_createtcp(query->dispatchmgr,
1999 query->tcpsocket,
2000 query->fctx->res->taskmgr,
2001 4096, 2, 1, 1, 3, attrs,
2002 &query->dispatch);
2003
2004 /*
2005 * Regardless of whether dns_dispatch_create()
2006 * succeeded or not, we don't need our reference
2007 * to the socket anymore.
2008 */
2009 isc_socket_detach(&query->tcpsocket);
2010
2011 if (result == ISC_R_SUCCESS)
2012 result = resquery_send(query);
2013
2014 if (result != ISC_R_SUCCESS) {
2015 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
2016 fctx_done(fctx, result, __LINE__);
2017 }
2018 break;
2019
2020 case ISC_R_NETUNREACH:
2021 case ISC_R_HOSTUNREACH:
2022 case ISC_R_CONNREFUSED:
2023 case ISC_R_NOPERM:
2024 case ISC_R_ADDRNOTAVAIL:
2025 case ISC_R_CONNECTIONRESET:
2026 /*
2027 * No route to remote.
2028 */
2029 isc_socket_detach(&query->tcpsocket);
2030 fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
2031 retry = ISC_TRUE;
2032 break;
2033
2034 default:
2035 isc_socket_detach(&query->tcpsocket);
2036 fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
2037 break;
2038 }
2039 }
2040
2041 isc_event_free(&event);
2042
2043 if (retry) {
2044 /*
2045 * Behave as if the idle timer has expired. For TCP
2046 * connections this may not actually reflect the latest timer.
2047 */
2048 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
2049 result = fctx_stopidletimer(fctx);
2050 if (result != ISC_R_SUCCESS)
2051 fctx_done(fctx, result, __LINE__);
2052 else
2053 fctx_try(fctx, ISC_TRUE);
2054 }
2055}
2056
2057static void
2058fctx_finddone(isc_task_t *task, isc_event_t *event) {
2059 fetchctx_t *fctx;
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;
2066
2067 find = event->ev_sender;
2068 fctx = event->ev_arg;
2069 REQUIRE(VALID_FCTX(fctx));
2070 res = fctx->res;
2071
2072 UNUSED(task);
2073
2074 FCTXTRACE("finddone");
2075
2076 INSIST(fctx->pending > 0);
2077 fctx->pending--;
2078
2079 if (ADDRWAIT(fctx)) {
2080 /*
2081 * The fetch is waiting for a name to be found.
2082 */
2083 INSIST(!SHUTTINGDOWN(fctx));
2084 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
2085 if (event->ev_type == DNS_EVENT_ADBMOREADDRESSES)
2086 want_try = ISC_TRUE;
2087 else {
2088 fctx->findfail++;
2089 if (fctx->pending == 0) {
2090 /*
2091 * We've got nothing else to wait for and don't
2092 * know the answer. There's nothing to do but
2093 * fail the fctx.
2094 */
2095 want_done = ISC_TRUE;
2096 }
2097 }
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);
2102 /*
2103 * Note that we had to wait until we had the lock before
2104 * looking at fctx->references.
2105 */
2106 if (fctx->references == 0)
2107 bucket_empty = fctx_destroy(fctx);
2108 UNLOCK(&res->buckets[bucketnum].lock);
2109 }
2110
2111 isc_event_free(&event);
2112 dns_adb_destroyfind(&find);
2113
2114 if (want_try)
2115 fctx_try(fctx, ISC_TRUE);
2116 else if (want_done)
2117 fctx_done(fctx, ISC_R_FAILURE, __LINE__);
2118 else if (bucket_empty)
2119 empty_bucket(res);
2120}
2121
2122
2123static inline isc_boolean_t
2124bad_server(fetchctx_t *fctx, isc_sockaddr_t *address) {
2125 isc_sockaddr_t *sa;
2126
2127 for (sa = ISC_LIST_HEAD(fctx->bad);
2128 sa != NULL;
2129 sa = ISC_LIST_NEXT(sa, link)) {
2130 if (isc_sockaddr_equal(sa, address))
2131 return (ISC_TRUE);
2132 }
2133
2134 return (ISC_FALSE);
2135}
2136
2137static inline isc_boolean_t
2138mark_bad(fetchctx_t *fctx) {
2139 dns_adbfind_t *curr;
2140 dns_adbaddrinfo_t *addrinfo;
2141 isc_boolean_t all_bad = ISC_TRUE;
2142
2143 /*
2144 * Mark all known bad servers, so we don't try to talk to them
2145 * again.
2146 */
2147
2148 /*
2149 * Mark any bad nameservers.
2150 */
2151 for (curr = ISC_LIST_HEAD(fctx->finds);
2152 curr != NULL;
2153 curr = ISC_LIST_NEXT(curr, publink)) {
2154 for (addrinfo = ISC_LIST_HEAD(curr->list);
2155 addrinfo != NULL;
2156 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2157 if (bad_server(fctx, &addrinfo->sockaddr))
2158 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2159 else
2160 all_bad = ISC_FALSE;
2161 }
2162 }
2163
2164 /*
2165 * Mark any bad forwarders.
2166 */
2167 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
2168 addrinfo != NULL;
2169 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2170 if (bad_server(fctx, &addrinfo->sockaddr))
2171 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2172 else
2173 all_bad = ISC_FALSE;
2174 }
2175
2176 /*
2177 * Mark any bad alternates.
2178 */
2179 for (curr = ISC_LIST_HEAD(fctx->altfinds);
2180 curr != NULL;
2181 curr = ISC_LIST_NEXT(curr, publink)) {
2182 for (addrinfo = ISC_LIST_HEAD(curr->list);
2183 addrinfo != NULL;
2184 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2185 if (bad_server(fctx, &addrinfo->sockaddr))
2186 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2187 else
2188 all_bad = ISC_FALSE;
2189 }
2190 }
2191
2192 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
2193 addrinfo != NULL;
2194 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2195 if (bad_server(fctx, &addrinfo->sockaddr))
2196 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2197 else
2198 all_bad = ISC_FALSE;
2199 }
2200
2201 return (all_bad);
2202}
2203
2204static void
2205add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_result_t reason,
2206 badnstype_t badtype)
2207{
2208 char namebuf[DNS_NAME_FORMATSIZE];
2209 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
2210 char classbuf[64];
2211 char typebuf[64];
2212 char code[64];
2213 isc_buffer_t b;
2214 isc_sockaddr_t *sa;
2215 const char *sep1, *sep2;
2216 isc_sockaddr_t *address = &addrinfo->sockaddr;
2217
2218 if (reason == DNS_R_LAME)
2219 fctx->lamecount++;
2220 else {
2221 switch (badtype) {
2222 case badns_unreachable:
2223 fctx->neterr++;
2224 break;
2225 case badns_response:
2226 fctx->badresp++;
2227 break;
2228 case badns_validation:
2229 break; /* counted as 'valfail' */
2230 }
2231 }
2232
2233 if (bad_server(fctx, address)) {
2234 /*
2235 * We already know this server is bad.
2236 */
2237 return;
2238 }
2239
2240 FCTXTRACE("add_bad");
2241
2242 sa = isc_mem_get(fctx->res->buckets[fctx->bucketnum].mctx,
2243 sizeof(*sa));
2244 if (sa == NULL)
2245 return;
2246 *sa = *address;
2247 ISC_LIST_INITANDAPPEND(fctx->bad, sa, link);
2248
2249 if (reason == DNS_R_LAME) /* already logged */
2250 return;
2251
2252 if (reason == DNS_R_UNEXPECTEDRCODE &&
2253 fctx->rmessage->rcode == dns_rcode_servfail &&
2254 ISFORWARDER(addrinfo))
2255 return;
2256
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';
2261 sep1 = "(";
2262 sep2 = ") ";
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';
2267 sep1 = "(";
2268 sep2 = ") ";
2269 } else {
2270 code[0] = '\0';
2271 sep1 = "";
2272 sep2 = "";
2273 }
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);
2283}
2284
2285static void
2286sort_adbfind(dns_adbfind_t *find) {
2287 dns_adbaddrinfo_t *best, *curr;
2288 dns_adbaddrinfolist_t sorted;
2289
2290 /*
2291 * Lame N^2 bubble sort.
2292 */
2293
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)
2300 best = curr;
2301 curr = ISC_LIST_NEXT(curr, publink);
2302 }
2303 ISC_LIST_UNLINK(find->list, best, publink);
2304 ISC_LIST_APPEND(sorted, best, publink);
2305 }
2306 find->list = sorted;
2307}
2308
2309static void
2310sort_finds(fetchctx_t *fctx) {
2311 dns_adbfind_t *best, *curr;
2312 dns_adbfindlist_t sorted;
2313 dns_adbaddrinfo_t *addrinfo, *bestaddrinfo;
2314
2315 /*
2316 * Lame N^2 bubble sort.
2317 */
2318
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) {
2329 best = curr;
2330 bestaddrinfo = addrinfo;
2331 }
2332 curr = ISC_LIST_NEXT(curr, publink);
2333 }
2334 ISC_LIST_UNLINK(fctx->finds, best, publink);
2335 ISC_LIST_APPEND(sorted, best, publink);
2336 }
2337 fctx->finds = sorted;
2338
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) {
2349 best = curr;
2350 bestaddrinfo = addrinfo;
2351 }
2352 curr = ISC_LIST_NEXT(curr, publink);
2353 }
2354 ISC_LIST_UNLINK(fctx->altfinds, best, publink);
2355 ISC_LIST_APPEND(sorted, best, publink);
2356 }
2357 fctx->altfinds = sorted;
2358}
2359
2360static void
2361findname(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)
2364{
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;
2370
2371 res = fctx->res;
2372 unshared = ISC_TF((fctx->options | DNS_FETCHOPT_UNSHARED) != 0);
2373 /*
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
2378 * expired).
2379 */
2380 if (dns_name_issubdomain(name, &fctx->domain))
2381 options |= DNS_ADBFIND_STARTATZONE;
2382 options |= DNS_ADBFIND_GLUEOK;
2383 options |= DNS_ADBFIND_HINTOK;
2384
2385 /*
2386 * See what we know about this address.
2387 */
2388 find = NULL;
2389 result = dns_adb_createfind(fctx->adb,
2390 res->buckets[fctx->bucketnum].task,
2391 fctx_finddone, fctx, name,
2392 &fctx->name, fctx->type,
2393 options, now, NULL,
2394 res->view->dstport, &find);
2395 if (result != ISC_R_SUCCESS) {
2396 if (result == DNS_R_ALIAS) {
2397 /*
2398 * XXXRTH Follow the CNAME/DNAME chain?
2399 */
2400 dns_adb_destroyfind(&find);
2401 fctx->adberr++;
2402 }
2403 } else if (!ISC_LIST_EMPTY(find->list)) {
2404 /*
2405 * We have at least some of the addresses for the
2406 * name.
2407 */
2408 INSIST((find->options & DNS_ADBFIND_WANTEVENT) == 0);
2409 sort_adbfind(find);
2410 if (flags != 0 || port != 0) {
2411 for (ai = ISC_LIST_HEAD(find->list);
2412 ai != NULL;
2413 ai = ISC_LIST_NEXT(ai, publink)) {
2414 ai->flags |= flags;
2415 if (port != 0)
2416 isc_sockaddr_setport(&ai->sockaddr,
2417 port);
2418 }
2419 }
2420 if ((flags & FCTX_ADDRINFO_FORWARDER) != 0)
2421 ISC_LIST_APPEND(fctx->altfinds, find, publink);
2422 else
2423 ISC_LIST_APPEND(fctx->finds, find, publink);
2424 } else {
2425 /*
2426 * We don't know any of the addresses for this
2427 * name.
2428 */
2429 if ((find->options & DNS_ADBFIND_WANTEVENT) != 0) {
2430 /*
2431 * We're looking for them and will get an
2432 * event about it later.
2433 */
2434 fctx->pending++;
2435 /*
2436 * Bootstrap.
2437 */
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;
2445 } else {
2446 if ((find->options & DNS_ADBFIND_LAMEPRUNED) != 0)
2447 fctx->lamecount++; /* cached lame server */
2448 else
2449 fctx->adberr++; /* unreachable server, etc. */
2450
2451 /*
2452 * If we know there are no addresses for
2453 * the family we are using then try to add
2454 * an alternative server.
2455 */
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);
2463 }
2464 }
2465}
2466
2467static isc_boolean_t
2468isstrictsubdomain(dns_name_t *name1, dns_name_t *name2) {
2469 int order;
2470 unsigned int nlabels;
2471 dns_namereln_t namereln;
2472
2473 namereln = dns_name_fullcompare(name1, name2, &order, &nlabels);
2474 return (ISC_TF(namereln == dns_namereln_subdomain));
2475}
2476
2477static isc_result_t
2478fctx_getaddresses(fetchctx_t *fctx) {
2479 dns_rdata_t rdata = DNS_RDATA_INIT;
2480 isc_result_t result;
2481 dns_resolver_t *res;
2482 isc_stdtime_t now;
2483 unsigned int stdoptions;
2484 isc_sockaddr_t *sa;
2485 dns_adbaddrinfo_t *ai;
2486 isc_boolean_t all_bad;
2487 dns_rdata_ns_t ns;
2488 isc_boolean_t need_alternate = ISC_FALSE;
2489
2490 FCTXTRACE("getaddresses");
2491
2492 /*
2493 * Don't pound on remote servers. (Failsafe!)
2494 */
2495 fctx->restarts++;
2496 if (fctx->restarts > 10) {
2497 FCTXTRACE("too many restarts");
2498 return (DNS_R_SERVFAIL);
2499 }
2500
2501 res = fctx->res;
2502 stdoptions = 0; /* Keep compiler happy. */
2503
2504 /*
2505 * Forwarders.
2506 */
2507
2508 INSIST(ISC_LIST_EMPTY(fctx->forwaddrs));
2509 INSIST(ISC_LIST_EMPTY(fctx->altaddrs));
2510
2511 /*
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).
2515 */
2516 sa = ISC_LIST_HEAD(fctx->forwarders);
2517 if (sa == NULL) {
2518 dns_forwarders_t *forwarders = NULL;
2519 dns_name_t *name = &fctx->name;
2520 dns_name_t suffix;
2521 unsigned int labels;
2522 dns_fixedname_t fixed;
2523 dns_name_t *domain;
2524
2525 /*
2526 * DS records are found in the parent server.
2527 * Strip label to get the correct forwarder (if any).
2528 */
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);
2534 name = &suffix;
2535 }
2536
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)) {
2546 isc_mem_t *mctx;
2547
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,
2552 &fctx->domain);
2553 if (result != ISC_R_SUCCESS)
2554 return (result);
2555 }
2556 }
2557 }
2558
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);
2565 continue;
2566 }
2567 ai = NULL;
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);
2576 if (cur != NULL)
2577 ISC_LIST_INSERTBEFORE(fctx->forwaddrs, cur,
2578 ai, publink);
2579 else
2580 ISC_LIST_APPEND(fctx->forwaddrs, ai, publink);
2581 }
2582 sa = ISC_LIST_NEXT(sa, link);
2583 }
2584
2585 /*
2586 * If the forwarding policy is "only", we don't need the addresses
2587 * of the nameservers.
2588 */
2589 if (fctx->fwdpolicy == dns_fwdpolicy_only)
2590 goto out;
2591
2592 /*
2593 * Normal nameservers.
2594 */
2595
2596 stdoptions = DNS_ADBFIND_WANTEVENT | DNS_ADBFIND_EMPTYEVENT;
2597 if (fctx->restarts == 1) {
2598 /*
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
2603 * can use.
2604 *
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.
2608 */
2609 stdoptions |= DNS_ADBFIND_AVOIDFETCHES;
2610 }
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);
2616
2617 INSIST(ISC_LIST_EMPTY(fctx->finds));
2618 INSIST(ISC_LIST_EMPTY(fctx->altfinds));
2619
2620 for (result = dns_rdataset_first(&fctx->nameservers);
2621 result == ISC_R_SUCCESS;
2622 result = dns_rdataset_next(&fctx->nameservers))
2623 {
2624 dns_rdataset_current(&fctx->nameservers, &rdata);
2625 /*
2626 * Extract the name from the NS record.
2627 */
2628 result = dns_rdata_tostruct(&rdata, &ns, NULL);
2629 if (result != ISC_R_SUCCESS)
2630 continue;
2631
2632 findname(fctx, &ns.name, 0, stdoptions, 0, now,
2633 &need_alternate);
2634 dns_rdata_reset(&rdata);
2635 dns_rdata_freestruct(&ns);
2636 }
2637 if (result != ISC_R_NOMORE)
2638 return (result);
2639
2640 /*
2641 * Do we need to use 6 to 4?
2642 */
2643 if (need_alternate) {
2644 int family;
2645 alternate_t *a;
2646 family = (res->dispatchv6 != NULL) ? AF_INET6 : AF_INET;
2647 for (a = ISC_LIST_HEAD(fctx->res->alternates);
2648 a != NULL;
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,
2653 now, NULL);
2654 continue;
2655 }
2656 if (isc_sockaddr_pf(&a->_u.addr) != family)
2657 continue;
2658 ai = NULL;
2659 result = dns_adb_findaddrinfo(fctx->adb, &a->_u.addr,
2660 &ai, 0);
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);
2667 if (cur != NULL)
2668 ISC_LIST_INSERTBEFORE(fctx->altaddrs,
2669 cur, ai, publink);
2670 else
2671 ISC_LIST_APPEND(fctx->altaddrs, ai,
2672 publink);
2673 }
2674 }
2675 }
2676
2677 out:
2678 /*
2679 * Mark all known bad servers.
2680 */
2681 all_bad = mark_bad(fctx);
2682
2683 /*
2684 * How are we doing?
2685 */
2686 if (all_bad) {
2687 /*
2688 * We've got no addresses.
2689 */
2690 if (fctx->pending > 0) {
2691 /*
2692 * We're fetching the addresses, but don't have any
2693 * yet. Tell the caller to wait for an answer.
2694 */
2695 result = DNS_R_WAIT;
2696 } else {
2697 /*
2698 * We've lost completely. We don't know any
2699 * addresses, and the ADB has told us it can't get
2700 * them.
2701 */
2702 FCTXTRACE("no addresses");
2703 result = ISC_R_FAILURE;
2704 }
2705 } else {
2706 /*
2707 * We've found some addresses. We might still be looking
2708 * for more addresses.
2709 */
2710 sort_finds(fctx);
2711 result = ISC_R_SUCCESS;
2712 }
2713
2714 return (result);
2715}
2716
2717static inline void
2718possibly_mark(fetchctx_t *fctx, dns_adbaddrinfo_t *addr)
2719{
2720 isc_netaddr_t na;
2721 char buf[ISC_NETADDR_FORMATSIZE];
2722 isc_sockaddr_t *sa;
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;
2730
2731 sa = &addr->sockaddr;
2732
2733 res = fctx->res;
2734 isc_netaddr_fromsockaddr(&ipaddr, sa);
2735 blackhole = dns_dispatchmgr_getblackhole(res->dispatchmgr);
2736 (void) dns_peerlist_peerbyaddr(res->view->peers, &ipaddr, &peer);
2737
2738 if (blackhole != NULL) {
2739 int match;
2740
2741 if (dns_acl_match(&ipaddr, NULL, blackhole,
2742 &res->view->aclenv,
2743 &match, NULL) == ISC_R_SUCCESS &&
2744 match > 0)
2745 aborted = ISC_TRUE;
2746 }
2747
2748 if (peer != NULL &&
2749 dns_peer_getbogus(peer, &bogus) == ISC_R_SUCCESS &&
2750 bogus)
2751 aborted = ISC_TRUE;
2752
2753 if (aborted) {
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) {
2763 return;
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: ";
2770 } else
2771 return;
2772
2773 if (!isc_log_wouldlog(dns_lctx, ISC_LOG_DEBUG(3)))
2774 return;
2775
2776 isc_netaddr_fromsockaddr(&na, sa);
2777 isc_netaddr_format(&na, buf, sizeof(buf));
2778 FCTXTRACE2(msg, buf);
2779}
2780
2781static inline dns_adbaddrinfo_t *
2782fctx_nextaddress(fetchctx_t *fctx) {
2783 dns_adbfind_t *find, *start;
2784 dns_adbaddrinfo_t *addrinfo;
2785 dns_adbaddrinfo_t *faddrinfo;
2786
2787 /*
2788 * Return the next untried address, if any.
2789 */
2790
2791 /*
2792 * Find the first unmarked forwarder (if any).
2793 */
2794 for (addrinfo = ISC_LIST_HEAD(fctx->forwaddrs);
2795 addrinfo != NULL;
2796 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2797 if (!UNMARKED(addrinfo))
2798 continue;
2799 possibly_mark(fctx, addrinfo);
2800 if (UNMARKED(addrinfo)) {
2801 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2802 fctx->find = NULL;
2803 return (addrinfo);
2804 }
2805 }
2806
2807 /*
2808 * No forwarders. Move to the next find.
2809 */
2810
2811 fctx->attributes |= FCTX_ATTR_TRIEDFIND;
2812
2813 find = fctx->find;
2814 if (find == NULL)
2815 find = ISC_LIST_HEAD(fctx->finds);
2816 else {
2817 find = ISC_LIST_NEXT(find, publink);
2818 if (find == NULL)
2819 find = ISC_LIST_HEAD(fctx->finds);
2820 }
2821
2822 /*
2823 * Find the first unmarked addrinfo.
2824 */
2825 addrinfo = NULL;
2826 if (find != NULL) {
2827 start = find;
2828 do {
2829 for (addrinfo = ISC_LIST_HEAD(find->list);
2830 addrinfo != NULL;
2831 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2832 if (!UNMARKED(addrinfo))
2833 continue;
2834 possibly_mark(fctx, addrinfo);
2835 if (UNMARKED(addrinfo)) {
2836 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2837 break;
2838 }
2839 }
2840 if (addrinfo != NULL)
2841 break;
2842 find = ISC_LIST_NEXT(find, publink);
2843 if (find == NULL)
2844 find = ISC_LIST_HEAD(fctx->finds);
2845 } while (find != start);
2846 }
2847
2848 fctx->find = find;
2849 if (addrinfo != NULL)
2850 return (addrinfo);
2851
2852 /*
2853 * No nameservers left. Try alternates.
2854 */
2855
2856 fctx->attributes |= FCTX_ATTR_TRIEDALT;
2857
2858 find = fctx->altfind;
2859 if (find == NULL)
2860 find = ISC_LIST_HEAD(fctx->altfinds);
2861 else {
2862 find = ISC_LIST_NEXT(find, publink);
2863 if (find == NULL)
2864 find = ISC_LIST_HEAD(fctx->altfinds);
2865 }
2866
2867 /*
2868 * Find the first unmarked addrinfo.
2869 */
2870 addrinfo = NULL;
2871 if (find != NULL) {
2872 start = find;
2873 do {
2874 for (addrinfo = ISC_LIST_HEAD(find->list);
2875 addrinfo != NULL;
2876 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2877 if (!UNMARKED(addrinfo))
2878 continue;
2879 possibly_mark(fctx, addrinfo);
2880 if (UNMARKED(addrinfo)) {
2881 addrinfo->flags |= FCTX_ADDRINFO_MARK;
2882 break;
2883 }
2884 }
2885 if (addrinfo != NULL)
2886 break;
2887 find = ISC_LIST_NEXT(find, publink);
2888 if (find == NULL)
2889 find = ISC_LIST_HEAD(fctx->altfinds);
2890 } while (find != start);
2891 }
2892
2893 faddrinfo = addrinfo;
2894
2895 /*
2896 * See if we have a better alternate server by address.
2897 */
2898
2899 for (addrinfo = ISC_LIST_HEAD(fctx->altaddrs);
2900 addrinfo != NULL;
2901 addrinfo = ISC_LIST_NEXT(addrinfo, publink)) {
2902 if (!UNMARKED(addrinfo))
2903 continue;
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;
2911 break;
2912 }
2913 }
2914
2915 if (addrinfo == NULL) {
2916 addrinfo = faddrinfo;
2917 fctx->altfind = find;
2918 }
2919
2920 return (addrinfo);
2921}
2922
2923static void
2924fctx_try(fetchctx_t *fctx, isc_boolean_t retrying) {
2925 isc_result_t result;
2926 dns_adbaddrinfo_t *addrinfo;
2927
2928 FCTXTRACE("try");
2929
2930 REQUIRE(!ADDRWAIT(fctx));
2931
2932 addrinfo = fctx_nextaddress(fctx);
2933 if (addrinfo == NULL) {
2934 /*
2935 * We have no more addresses. Start over.
2936 */
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) {
2944 /*
2945 * Sleep waiting for addresses.
2946 */
2947 FCTXTRACE("addrwait");
2948 fctx->attributes |= FCTX_ATTR_ADDRWAIT;
2949 return;
2950 } else if (result != ISC_R_SUCCESS) {
2951 /*
2952 * Something bad happened.
2953 */
2954 fctx_done(fctx, result, __LINE__);
2955 return;
2956 }
2957
2958 addrinfo = fctx_nextaddress(fctx);
2959 /*
2960 * While we may have addresses from the ADB, they
2961 * might be bad ones. In this case, return SERVFAIL.
2962 */
2963 if (addrinfo == NULL) {
2964 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
2965 return;
2966 }
2967 }
2968
2969 result = fctx_query(fctx, addrinfo, fctx->options);
2970 if (result != ISC_R_SUCCESS)
2971 fctx_done(fctx, result, __LINE__);
2972 else if (retrying)
2973 inc_stats(fctx->res, dns_resstatscounter_retry);
2974}
2975
2976static isc_boolean_t
2977fctx_destroy(fetchctx_t *fctx) {
2978 dns_resolver_t *res;
2979 unsigned int bucketnum;
2980 isc_sockaddr_t *sa, *next_sa;
2981
2982 /*
2983 * Caller must be holding the bucket lock.
2984 */
2985
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));
2996
2997 FCTXTRACE("destroy");
2998
2999 res = fctx->res;
3000 bucketnum = fctx->bucketnum;
3001
3002 ISC_LIST_UNLINK(res->buckets[bucketnum].fctxs, fctx, link);
3003
3004 /*
3005 * Free bad.
3006 */
3007 for (sa = ISC_LIST_HEAD(fctx->bad);
3008 sa != NULL;
3009 sa = next_sa) {
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));
3013 }
3014
3015 for (sa = ISC_LIST_HEAD(fctx->edns);
3016 sa != NULL;
3017 sa = next_sa) {
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));
3021 }
3022
3023 for (sa = ISC_LIST_HEAD(fctx->edns512);
3024 sa != NULL;
3025 sa = next_sa) {
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));
3029 }
3030
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));
3043
3044 LOCK(&res->nlock);
3045 res->nfctx--;
3046 UNLOCK(&res->nlock);
3047
3048 if (res->buckets[bucketnum].exiting &&
3049 ISC_LIST_EMPTY(res->buckets[bucketnum].fctxs))
3050 return (ISC_TRUE);
3051
3052 return (ISC_FALSE);
3053}
3054
3055/*
3056 * Fetch event handlers.
3057 */
3058
3059static void
3060fctx_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;
3063 resquery_t *query;
3064
3065 REQUIRE(VALID_FCTX(fctx));
3066
3067 UNUSED(task);
3068
3069 FCTXTRACE("timeout");
3070
3071 inc_stats(fctx->res, dns_resstatscounter_querytimeout);
3072
3073 if (event->ev_type == ISC_TIMEREVENT_LIFE) {
3074 fctx->reason = NULL;
3075 fctx_done(fctx, ISC_R_TIMEDOUT, __LINE__);
3076 } else {
3077 isc_result_t result;
3078
3079 fctx->timeouts++;
3080 fctx->timeout = ISC_TRUE;
3081 /*
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
3088 * timing).
3089 */
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);
3094 }
3095 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
3096 /*
3097 * Our timer has triggered. Reestablish the fctx lifetime
3098 * timer.
3099 */
3100 result = fctx_starttimer(fctx);
3101 if (result != ISC_R_SUCCESS)
3102 fctx_done(fctx, result, __LINE__);
3103 else
3104 /*
3105 * Keep trying.
3106 */
3107 fctx_try(fctx, ISC_TRUE);
3108 }
3109
3110 isc_event_free(&event);
3111}
3112
3113static void
3114fctx_shutdown(fetchctx_t *fctx) {
3115 isc_event_t *cevent;
3116
3117 /*
3118 * Start the shutdown process for fctx, if it isn't already underway.
3119 */
3120
3121 FCTXTRACE("shutdown");
3122
3123 /*
3124 * The caller must be holding the appropriate bucket lock.
3125 */
3126
3127 if (fctx->want_shutdown)
3128 return;
3129
3130 fctx->want_shutdown = ISC_TRUE;
3131
3132 /*
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
3136 * exit.
3137 */
3138 if (fctx->state != fetchstate_init) {
3139 cevent = &fctx->control_event;
3140 isc_task_send(fctx->res->buckets[fctx->bucketnum].task,
3141 &cevent);
3142 }
3143}
3144
3145static void
3146fctx_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;
3152
3153 REQUIRE(VALID_FCTX(fctx));
3154
3155 UNUSED(task);
3156
3157 res = fctx->res;
3158 bucketnum = fctx->bucketnum;
3159
3160 FCTXTRACE("doshutdown");
3161
3162 /*
3163 * An fctx that is shutting down is no longer in ADDRWAIT mode.
3164 */
3165 fctx->attributes &= ~FCTX_ATTR_ADDRWAIT;
3166
3167 /*
3168 * Cancel all pending validators. Note that this must be done
3169 * without the bucket lock held, since that could cause deadlock.
3170 */
3171 validator = ISC_LIST_HEAD(fctx->validators);
3172 while (validator != NULL) {
3173 dns_validator_cancel(validator);
3174 validator = ISC_LIST_NEXT(validator, link);
3175 }
3176
3177 if (fctx->nsfetch != NULL)
3178 dns_resolver_cancelfetch(fctx->nsfetch);
3179
3180 /*
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.
3184 */
3185 fctx_stopeverything(fctx, ISC_FALSE);
3186
3187 LOCK(&res->buckets[bucketnum].lock);
3188
3189 fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN;
3190
3191 INSIST(fctx->state == fetchstate_active ||
3192 fctx->state == fetchstate_done);
3193 INSIST(fctx->want_shutdown);
3194
3195 if (fctx->state != fetchstate_done) {
3196 fctx->state = fetchstate_done;
3197 fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__);
3198 }
3199
3200 if (fctx->references == 0 && fctx->pending == 0 &&
3201 fctx->nqueries == 0 && ISC_LIST_EMPTY(fctx->validators))
3202 bucket_empty = fctx_destroy(fctx);
3203
3204 UNLOCK(&res->buckets[bucketnum].lock);
3205
3206 if (bucket_empty)
3207 empty_bucket(res);
3208}
3209
3210static void
3211fctx_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;
3216
3217 REQUIRE(VALID_FCTX(fctx));
3218
3219 UNUSED(task);
3220
3221 res = fctx->res;
3222 bucketnum = fctx->bucketnum;
3223
3224 FCTXTRACE("start");
3225
3226 LOCK(&res->buckets[bucketnum].lock);
3227
3228 INSIST(fctx->state == fetchstate_init);
3229 if (fctx->want_shutdown) {
3230 /*
3231 * We haven't started this fctx yet, and we've been requested
3232 * to shut it down.
3233 */
3234 fctx->attributes |= FCTX_ATTR_SHUTTINGDOWN;
3235 fctx->state = fetchstate_done;
3236 fctx_sendevents(fctx, ISC_R_CANCELED, __LINE__);
3237 /*
3238 * Since we haven't started, we INSIST that we have no
3239 * pending ADB finds and no pending validations.
3240 */
3241 INSIST(fctx->pending == 0);
3242 INSIST(fctx->nqueries == 0);
3243 INSIST(ISC_LIST_EMPTY(fctx->validators));
3244 if (fctx->references == 0) {
3245 /*
3246 * It's now safe to destroy this fctx.
3247 */
3248 bucket_empty = fctx_destroy(fctx);
3249 }
3250 done = ISC_TRUE;
3251 } else {
3252 /*
3253 * Normal fctx startup.
3254 */
3255 fctx->state = fetchstate_active;
3256 /*
3257 * Reset the control event for later use in shutting down
3258 * the fctx.
3259 */
3260 ISC_EVENT_INIT(event, sizeof(*event), 0, NULL,
3261 DNS_EVENT_FETCHCONTROL, fctx_doshutdown, fctx,
3262 NULL, NULL, NULL);
3263 }
3264
3265 UNLOCK(&res->buckets[bucketnum].lock);
3266
3267 if (!done) {
3268 isc_result_t result;
3269
3270 /*
3271 * All is well. Start working on the fetch.
3272 */
3273 result = fctx_starttimer(fctx);
3274 if (result != ISC_R_SUCCESS)
3275 fctx_done(fctx, result, __LINE__);
3276 else
3277 fctx_try(fctx, ISC_FALSE);
3278 } else if (bucket_empty)
3279 empty_bucket(res);
3280}
3281
3282/*
3283 * Fetch Creation, Joining, and Cancelation.
3284 */
3285
3286static inline isc_result_t
3287fctx_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,
3290 dns_fetch_t *fetch)
3291{
3292 isc_task_t *clone;
3293 dns_fetchevent_t *event;
3294
3295 FCTXTRACE("join");
3296
3297 /*
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
3300 * send the event.
3301 */
3302 clone = NULL;
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);
3310 }
3311 event->result = DNS_R_SERVFAIL;
3312 event->qtype = fctx->type;
3313 event->db = NULL;
3314 event->node = NULL;
3315 event->rdataset = rdataset;
3316 event->sigrdataset = sigrdataset;
3317 event->fetch = fetch;
3318 event->client = client;
3319 event->id = id;
3320 dns_fixedname_init(&event->foundname);
3321
3322 /*
3323 * Make sure that we can store the sigrdataset in the
3324 * first event if it is needed by any of the events.
3325 */
3326 if (event->sigrdataset != NULL)
3327 ISC_LIST_PREPEND(fctx->events, event, ev_link);
3328 else
3329 ISC_LIST_APPEND(fctx->events, event, ev_link);
3330 fctx->references++;
3331
3332 fetch->magic = DNS_FETCH_MAGIC;
3333 fetch->private = fctx;
3334
3335 return (ISC_R_SUCCESS);
3336}
3337
3338static isc_result_t
3339fctx_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)
3342{
3343 fetchctx_t *fctx;
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];
3351 dns_name_t suffix;
3352
3353 /*
3354 * Caller must be holding the lock for bucket number 'bucketnum'.
3355 */
3356 REQUIRE(fctxp != NULL && *fctxp == NULL);
3357
3358 fctx = isc_mem_get(res->buckets[bucketnum].mctx, sizeof(*fctx));
3359 if (fctx == NULL)
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;
3368 goto cleanup_fetch;
3369 }
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)
3374 goto cleanup_info;
3375 dns_name_init(&fctx->domain, NULL);
3376 dns_rdataset_init(&fctx->nameservers);
3377
3378 fctx->type = type;
3379 fctx->options = options;
3380 /*
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
3383 * using it.
3384 */
3385 fctx->res = res;
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;
3403 fctx->find = NULL;
3404 fctx->altfind = NULL;
3405 fctx->pending = 0;
3406 fctx->restarts = 0;
3407 fctx->querysent = 0;
3408 fctx->referrals = 0;
3409 TIME_NOW(&fctx->start);
3410 fctx->timeouts = 0;
3411 fctx->lamecount = 0;
3412 fctx->adberr = 0;
3413 fctx->neterr = 0;
3414 fctx->badresp = 0;
3415 fctx->findfail = 0;
3416 fctx->valfail = 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;
3423 fctx->nqueries = 0;
3424 fctx->reason = NULL;
3425 fctx->timeout = ISC_FALSE;
3426
3427 dns_name_init(&fctx->nsname, NULL);
3428 fctx->nsfetch = NULL;
3429 dns_rdataset_init(&fctx->nsrrset);
3430
3431 if (domain == NULL) {
3432 dns_forwarders_t *forwarders = NULL;
3433 unsigned int labels;
3434 dns_name_t *fwdname = name;
3435
3436 /*
3437 * DS records are found in the parent server.
3438 * Strip label to get the correct forwarder (if any).
3439 */
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);
3445 fwdname = &suffix;
3446 }
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;
3453
3454 if (fctx->fwdpolicy != dns_fwdpolicy_only) {
3455 /*
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.
3459 */
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,
3464 &fctx->nameservers,
3465 NULL);
3466 if (result != ISC_R_SUCCESS)
3467 goto cleanup_name;
3468 result = dns_name_dup(domain,
3469 res->buckets[bucketnum].mctx,
3470 &fctx->domain);
3471 if (result != ISC_R_SUCCESS) {
3472 dns_rdataset_disassociate(&fctx->nameservers);
3473 goto cleanup_name;
3474 }
3475 } else {
3476 /*
3477 * We're in forward-only mode. Set the query domain.
3478 */
3479 result = dns_name_dup(domain,
3480 res->buckets[bucketnum].mctx,
3481 &fctx->domain);
3482 if (result != ISC_R_SUCCESS)
3483 goto cleanup_name;
3484 }
3485 } else {
3486 result = dns_name_dup(domain,
3487 res->buckets[bucketnum].mctx,
3488 &fctx->domain);
3489 if (result != ISC_R_SUCCESS)
3490 goto cleanup_name;
3491 dns_rdataset_clone(nameservers, &fctx->nameservers);
3492 }
3493
3494 INSIST(dns_name_issubdomain(&fctx->name, &fctx->domain));
3495
3496 fctx->qmessage = NULL;
3497 result = dns_message_create(res->buckets[bucketnum].mctx,
3498 DNS_MESSAGE_INTENTRENDER,
3499 &fctx->qmessage);
3500
3501 if (result != ISC_R_SUCCESS)
3502 goto cleanup_domain;
3503
3504 fctx->rmessage = NULL;
3505 result = dns_message_create(res->buckets[bucketnum].mctx,
3506 DNS_MESSAGE_INTENTPARSE,
3507 &fctx->rmessage);
3508
3509 if (result != ISC_R_SUCCESS)
3510 goto cleanup_qmessage;
3511
3512 /*
3513 * Compute an expiration time for the entire fetch.
3514 */
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;
3523 }
3524
3525 /*
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.
3529 */
3530 isc_interval_set(&fctx->interval, 2, 0);
3531
3532 /*
3533 * Create an inactive timer. It will be made active when the fetch
3534 * is actually started.
3535 */
3536 fctx->timer = NULL;
3537 iresult = isc_timer_create(res->timermgr, isc_timertype_inactive,
3538 NULL, NULL,
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;
3547 }
3548
3549 /*
3550 * Attach to the view's cache and adb.
3551 */
3552 fctx->cache = NULL;
3553 dns_db_attach(res->view->cachedb, &fctx->cache);
3554 fctx->adb = NULL;
3555 dns_adb_attach(res->view->adb, &fctx->adb);
3556
3557 ISC_LIST_INIT(fctx->events);
3558 ISC_LINK_INIT(fctx, link);
3559 fctx->magic = FCTX_MAGIC;
3560
3561 ISC_LIST_APPEND(res->buckets[bucketnum].fctxs, fctx, link);
3562
3563 LOCK(&res->nlock);
3564 res->nfctx++;
3565 UNLOCK(&res->nlock);
3566
3567 *fctxp = fctx;
3568
3569 return (ISC_R_SUCCESS);
3570
3571 cleanup_rmessage:
3572 dns_message_destroy(&fctx->rmessage);
3573
3574 cleanup_qmessage:
3575 dns_message_destroy(&fctx->qmessage);
3576
3577 cleanup_domain:
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);
3582
3583 cleanup_name:
3584 dns_name_free(&fctx->name, res->buckets[bucketnum].mctx);
3585
3586 cleanup_info:
3587 isc_mem_free(res->buckets[bucketnum].mctx, fctx->info);
3588
3589 cleanup_fetch:
3590 isc_mem_put(res->buckets[bucketnum].mctx, fctx, sizeof(*fctx));
3591
3592 return (result);
3593}
3594
3595/*
3596 * Handle Responses
3597 */
3598static inline isc_boolean_t
3599is_lame(fetchctx_t *fctx) {
3600 dns_message_t *message = fctx->rmessage;
3601 dns_name_t *name;
3602 dns_rdataset_t *rdataset;
3603 isc_result_t result;
3604
3605 if (message->rcode != dns_rcode_noerror &&
3606 message->rcode != dns_rcode_nxdomain)
3607 return (ISC_FALSE);
3608
3609 if (message->counts[DNS_SECTION_ANSWER] != 0)
3610 return (ISC_FALSE);
3611
3612 if (message->counts[DNS_SECTION_AUTHORITY] == 0)
3613 return (ISC_FALSE);
3614
3615 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
3616 while (result == ISC_R_SUCCESS) {
3617 name = NULL;
3618 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
3619 for (rdataset = ISC_LIST_HEAD(name->list);
3620 rdataset != NULL;
3621 rdataset = ISC_LIST_NEXT(rdataset, link)) {
3622 dns_namereln_t namereln;
3623 int order;
3624 unsigned int labels;
3625 if (rdataset->type != dns_rdatatype_ns)
3626 continue;
3627 namereln = dns_name_fullcompare(name, &fctx->domain,
3628 &order, &labels);
3629 if (namereln == dns_namereln_equal &&
3630 (message->flags & DNS_MESSAGEFLAG_AA) != 0)
3631 return (ISC_FALSE);
3632 if (namereln == dns_namereln_subdomain)
3633 return (ISC_FALSE);
3634 return (ISC_TRUE);
3635 }
3636 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
3637 }
3638
3639 return (ISC_FALSE);
3640}
3641
3642static inline void
3643log_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];
3647
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);
3655}
3656
3657static inline isc_result_t
3658same_question(fetchctx_t *fctx) {
3659 isc_result_t result;
3660 dns_message_t *message = fctx->rmessage;
3661 dns_name_t *name;
3662 dns_rdataset_t *rdataset;
3663
3664 /*
3665 * Caller must be holding the fctx lock.
3666 */
3667
3668 /*
3669 * XXXRTH Currently we support only one question.
3670 */
3671 if (message->counts[DNS_SECTION_QUESTION] != 1)
3672 return (DNS_R_FORMERR);
3673
3674 result = dns_message_firstname(message, DNS_SECTION_QUESTION);
3675 if (result != ISC_R_SUCCESS)
3676 return (result);
3677 name = NULL;
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);
3686
3687 return (ISC_R_SUCCESS);
3688}
3689
3690static void
3691clone_results(fetchctx_t *fctx) {
3692 dns_fetchevent_t *event, *hevent;
3693 isc_result_t result;
3694 dns_name_t *name, *hname;
3695
3696 FCTXTRACE("clone_results");
3697
3698 /*
3699 * Set up any other events to have the same data as the first
3700 * event.
3701 *
3702 * Caller must be holding the appropriate lock.
3703 */
3704
3705 fctx->cloned = ISC_TRUE;
3706 hevent = ISC_LIST_HEAD(fctx->events);
3707 if (hevent == NULL)
3708 return;
3709 hname = dns_fixedname_name(&hevent->foundname);
3710 for (event = ISC_LIST_NEXT(hevent, ev_link);
3711 event != NULL;
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;
3717 else
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);
3732 }
3733}
3734
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)
3742
3743
3744/*
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.
3748 *
3749 * Requires:
3750 * '*fctx' is shutting down.
3751 */
3752static void
3753maybe_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;
3758
3759 REQUIRE(SHUTTINGDOWN(fctx));
3760
3761 if (fctx->pending != 0 || fctx->nqueries != 0)
3762 return;
3763
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);
3768 /*
3769 * If this is a active validator wait for the cancel
3770 * to complete before calling dns_validator_destroy().
3771 */
3772 if (validator == fctx->validator)
3773 continue;
3774 ISC_LIST_UNLINK(fctx->validators, validator, link);
3775 dns_validator_destroy(&validator);
3776 }
3777
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);
3783
3784 if (bucket_empty)
3785 empty_bucket(res);
3786}
3787
3788/*
3789 * The validator has finished.
3790 */
3791static void
3792validated(isc_task_t *task, isc_event_t *event) {
3793 isc_result_t result = ISC_R_SUCCESS;
3794 isc_result_t eresult = ISC_R_SUCCESS;
3795 isc_stdtime_t now;
3796 fetchctx_t *fctx;
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;
3805 isc_uint32_t ttl;
3806 dns_dbnode_t *nsnode = NULL;
3807 dns_name_t *name;
3808 dns_rdataset_t *rdataset;
3809 dns_rdataset_t *sigrdataset;
3810 dns_valarg_t *valarg;
3811 dns_adbaddrinfo_t *addrinfo;
3812
3813 UNUSED(task); /* for now */
3814
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));
3821
3822 vevent = (dns_validatorevent_t *)event;
3823
3824 FCTXTRACE("received validation completion event");
3825
3826 ISC_LIST_UNLINK(fctx->validators, vevent->validator, link);
3827 fctx->validator = NULL;
3828
3829 /*
3830 * Destroy the validator early so that we can
3831 * destroy the fctx if necessary.
3832 */
3833 dns_validator_destroy(&vevent->validator);
3834 isc_mem_put(fctx->res->buckets[fctx->bucketnum].mctx,
3835 valarg, sizeof(*valarg));
3836
3837 negative = ISC_TF(vevent->rdataset == NULL);
3838
3839 sentresponse = ISC_TF((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0);
3840
3841 /*
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.
3845 */
3846 if (SHUTTINGDOWN(fctx) && !sentresponse) {
3847 maybe_destroy(fctx); /* Locks bucket. */
3848 goto cleanup_event;
3849 }
3850
3851 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
3852
3853 /*
3854 * If chaining, we need to make sure that the right result code is
3855 * returned, and that the rdatasets are bound.
3856 */
3857 if (vevent->result == ISC_R_SUCCESS &&
3858 !negative &&
3859 vevent->rdataset != NULL &&
3860 CHAINING(vevent->rdataset))
3861 {
3862 if (vevent->rdataset->type == dns_rdatatype_cname)
3863 eresult = DNS_R_CNAME;
3864 else {
3865 INSIST(vevent->rdataset->type == dns_rdatatype_dname);
3866 eresult = DNS_R_DNAME;
3867 }
3868 chaining = ISC_TRUE;
3869 } else
3870 chaining = ISC_FALSE;
3871
3872 /*
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)
3876 */
3877
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)) {
3884 /*
3885 * Don't bind rdatasets; the caller
3886 * will iterate the node.
3887 */
3888 } else {
3889 ardataset = hevent->rdataset;
3890 asigrdataset = hevent->sigrdataset;
3891 }
3892 }
3893
3894 if (vevent->result != ISC_R_SUCCESS) {
3895 FCTXTRACE("validation failed");
3896 inc_stats(fctx->res, dns_resstatscounter_valfail);
3897 fctx->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,
3902 ISC_TRUE, &node);
3903 if (result == ISC_R_SUCCESS)
3904 (void)dns_db_deleterdataset(fctx->cache, node, NULL,
3905 vevent->type, 0);
3906 if (result == ISC_R_SUCCESS && vevent->sigrdataset != NULL)
3907 (void)dns_db_deleterdataset(fctx->cache, node, NULL,
3908 dns_rdatatype_rrsig,
3909 vevent->type);
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. */
3922 else
3923 fctx_try(fctx, ISC_TRUE); /* Locks bucket. */
3924 return;
3925 }
3926
3927 isc_stdtime_get(&now);
3928
3929 if (negative) {
3930 dns_rdatatype_t covers;
3931 FCTXTRACE("nonexistence validation OK");
3932
3933 inc_stats(fctx->res, dns_resstatscounter_valnegsuccess);
3934
3935 if (fctx->rmessage->rcode == dns_rcode_nxdomain)
3936 covers = dns_rdatatype_any;
3937 else
3938 covers = fctx->type;
3939
3940 result = dns_db_findnode(fctx->cache, vevent->name, ISC_TRUE,
3941 &node);
3942 if (result != ISC_R_SUCCESS)
3943 goto noanswer_response;
3944
3945 /*
3946 * If we are asking for a SOA record set the cache time
3947 * to zero to facilitate locating the containing zone of
3948 * a arbitrary zone.
3949 */
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)
3954 ttl = 0;
3955
3956 result = ncache_adderesult(fctx->rmessage, fctx->cache, node,
3957 covers, now, ttl,
3958 ardataset, &eresult);
3959 if (result != ISC_R_SUCCESS)
3960 goto noanswer_response;
3961 goto answer_response;
3962 } else
3963 inc_stats(fctx->res, dns_resstatscounter_valsuccess);
3964
3965 FCTXTRACE("validation OK");
3966
3967 if (vevent->proofs[DNS_VALIDATOR_NOQNAMEPROOF] != NULL) {
3968
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;
3974 }
3975
3976 /*
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
3980 * event list.
3981 */
3982 result = dns_db_findnode(fctx->cache, vevent->name, ISC_TRUE, &node);
3983 if (result != ISC_R_SUCCESS)
3984 goto noanswer_response;
3985
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;
3994 else
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,
3999 asigrdataset);
4000 if (result != ISC_R_SUCCESS &&
4001 result != DNS_R_UNCHANGED)
4002 goto noanswer_response;
4003 }
4004
4005 if (sentresponse) {
4006 /*
4007 * If we only deferred the destroy because we wanted to cache
4008 * the data, destroy now.
4009 */
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. */
4014 goto cleanup_event;
4015 }
4016
4017 if (!ISC_LIST_EMPTY(fctx->validators)) {
4018 INSIST(!negative);
4019 INSIST(fctx->type == dns_rdatatype_any ||
4020 fctx->type == dns_rdatatype_rrsig ||