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BIND: update vendor tree to 9.5.2-P2
[dragonfly.git] / contrib / bind / lib / dns / resolver.c
blob82fbafb281dddfacbc957a9477f02a9ec8aa111d
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
18 /* $Id: resolver.c,v 1.355.12.44.2.2 2010/01/07 17:19:22 each Exp $ */
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
119 typedef struct fetchctx fetchctx_t;
120
121 typedef 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
155 typedef enum {
156 fetchstate_init = 0, /*%< Start event has not run yet. */
157 fetchstate_active,
158 fetchstate_done /*%< FETCHDONE events posted. */
159 } fetchstate;
160
161 typedef enum {
162 badns_unreachable = 0,
163 badns_response,
164 badns_validation
165 } badnstype_t;
166
167 struct 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
298 typedef struct {
299 dns_adbaddrinfo_t * addrinfo;
300 fetchctx_t * fctx;
301 } dns_valarg_t;
302
303 struct 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
311 typedef 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
319 typedef 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
331 struct 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
399 static void destroy(dns_resolver_t *res);
400 static void empty_bucket(dns_resolver_t *res);
401 static isc_result_t resquery_send(resquery_t *query);
402 static void resquery_response(isc_task_t *task, isc_event_t *event);
403 static void resquery_connected(isc_task_t *task, isc_event_t *event);
404 static void fctx_try(fetchctx_t *fctx, isc_boolean_t retrying);
405 static isc_boolean_t fctx_destroy(fetchctx_t *fctx);
406 static isc_result_t ncache_adderesult(dns_message_t *message,
407 dns_db_t *cache, dns_dbnode_t *node,
408 dns_rdatatype_t covers,
409 isc_stdtime_t now, dns_ttl_t maxttl,
410 dns_rdataset_t *ardataset,
411 isc_result_t *eresultp);
412 static void validated(isc_task_t *task, isc_event_t *event);
413 static void maybe_destroy(fetchctx_t *fctx);
414 static void add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
415 isc_result_t reason, badnstype_t badtype);
416
417 /*%
418 * Increment resolver-related statistics counters.
419 */
420 static inline void
421 inc_stats(dns_resolver_t *res, isc_statscounter_t counter) {
422 if (res->view->resstats != NULL)
423 isc_stats_increment(res->view->resstats, counter);
424 }
425
426 static isc_result_t
427 valcreate(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, dns_name_t *name,
428 dns_rdatatype_t type, dns_rdataset_t *rdataset,
429 dns_rdataset_t *sigrdataset, unsigned int valoptions,
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
464 static isc_boolean_t
465 rrsig_fromchildzone(fetchctx_t *fctx, dns_rdataset_t *rdataset) {
466 dns_namereln_t namereln;
467 dns_rdata_rrsig_t rrsig;
468 dns_rdata_t rdata = DNS_RDATA_INIT;
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
488 static isc_boolean_t
489 fix_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
645 static inline isc_result_t
646 fctx_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
658 static inline void
659 fctx_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
678 static inline isc_result_t
679 fctx_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
695 static inline void
696 resquery_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
713 static void
714 fctx_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
879 static void
880 fctx_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
893 static void
894 fctx_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
909 static void
910 fctx_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
925 static void
926 fctx_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
940 static void
941 fctx_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
955 static inline void
956 fctx_stopeverything(fetchctx_t *fctx, isc_boolean_t no_response) {
957 FCTXTRACE("stopeverything");
958 fctx_cancelqueries(fctx, no_response);
959 fctx_cleanupfinds(fctx);
960 fctx_cleanupaltfinds(fctx);
961 fctx_cleanupforwaddrs(fctx);
962 fctx_cleanupaltaddrs(fctx);
963 fctx_stoptimer(fctx);
964 }
965
966 static inline void
967 fctx_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
1051 static inline void
1052 log_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
1067 static void
1068 fctx_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
1099 static void
1100 process_sendevent(resquery_t *query, isc_event_t *event) {
1101 isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1102 isc_boolean_t retry = ISC_FALSE;
1103 isc_result_t result;
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
1160 static void
1161 resquery_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
1177 static void
1178 resquery_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
1202 static inline isc_result_t
1203 fctx_addopt(dns_message_t *message, unsigned int version,
1204 isc_uint16_t udpsize, isc_boolean_t request_nsid)
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
1268 static inline void
1269 fctx_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
1304 static isc_result_t
1305 fctx_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
1520 static isc_boolean_t
1521 triededns(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
1534 static void
1535 add_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
1550 static isc_boolean_t
1551 triededns512(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
1564 static void
1565 add_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
1580 static isc_result_t
1581 resquery_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
1931 static void
1932 resquery_connected(isc_task_t *task, isc_event_t *event) {
1933 isc_socketevent_t *sevent = (isc_socketevent_t *)event;
1934 resquery_t *query = event->ev_arg;
1935 isc_boolean_t retry = ISC_FALSE;
1936 isc_interval_t interval;
1937 isc_result_t result;
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
2057 static void
2058 fctx_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
2123 static inline isc_boolean_t
2124 bad_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
2137 static inline isc_boolean_t
2138 mark_bad(fetchctx_t *fctx) {
2139 dns_adbfind_t *curr;
2140 dns_adbaddrinfo_t *addrinfo;
2141 isc_boolean_t all_bad = ISC_TRUE;
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
2204 static void
2205 add_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
2285 static void
2286 sort_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
2309 static void
2310 sort_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
2360 static void
2361 findname(fetchctx_t *fctx, dns_name_t *name, in_port_t port,
2362 unsigned int options, unsigned int flags, isc_stdtime_t now,
2363 isc_boolean_t *need_alternate)
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
2467 static isc_boolean_t
2468 isstrictsubdomain(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
2477 static isc_result_t
2478 fctx_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
2717 static inline void
2718 possibly_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
2781 static inline dns_adbaddrinfo_t *
2782 fctx_nextaddress(fetchctx_t *fctx) {
2783 dns_adbfind_t *find, *start;
2784 dns_adbaddrinfo_t *addrinfo;
2785 dns_adbaddrinfo_t *faddrinfo;
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
2923 static void
2924 fctx_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
2976 static isc_boolean_t
2977 fctx_destroy(fetchctx_t *fctx) {
2978 dns_resolver_t *res;
2979 unsigned int bucketnum;
2980 isc_sockaddr_t *sa, *next_sa;
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
3059 static void
3060 fctx_timeout(isc_task_t *task, isc_event_t *event) {
3061 fetchctx_t *fctx = event->ev_arg;
3062 isc_timerevent_t *tevent = (isc_timerevent_t *)event;
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
3113 static void
3114 fctx_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
3145 static void
3146 fctx_doshutdown(isc_task_t *task, isc_event_t *event) {
3147 fetchctx_t *fctx = event->ev_arg;
3148 isc_boolean_t bucket_empty = ISC_FALSE;
3149 dns_resolver_t *res;
3150 unsigned int bucketnum;
3151 dns_validator_t *validator;
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
3210 static void
3211 fctx_start(isc_task_t *task, isc_event_t *event) {
3212 fetchctx_t *fctx = event->ev_arg;
3213 isc_boolean_t done = ISC_FALSE, bucket_empty = ISC_FALSE;
3214 dns_resolver_t *res;
3215 unsigned int bucketnum;
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
3286 static inline isc_result_t
3287 fctx_join(fetchctx_t *fctx, isc_task_t *task, isc_sockaddr_t *client,
3288 dns_messageid_t id, isc_taskaction_t action, void *arg,
3289 dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
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
3338 static isc_result_t
3339 fctx_create(dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type,
3340 dns_name_t *domain, dns_rdataset_t *nameservers,
3341 unsigned int options, unsigned int bucketnum, fetchctx_t **fctxp)
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 */
3598 static inline isc_boolean_t
3599 is_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
3642 static inline void
3643 log_lame(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo) {
3644 char namebuf[DNS_NAME_FORMATSIZE];
3645 char domainbuf[DNS_NAME_FORMATSIZE];
3646 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
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
3657 static inline isc_result_t
3658 same_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
3690 static void
3691 clone_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 */
3752 static void
3753 maybe_destroy(fetchctx_t *fctx) {
3754 unsigned int bucketnum;
3755 isc_boolean_t bucket_empty = ISC_FALSE;
3756 dns_resolver_t *res = fctx->res;
3757 dns_validator_t *validator, *next_validator;
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 */
3791 static void
3792 validated(isc_task_t *task, isc_event_t *event) {
3793 isc_result_t result = ISC_R_SUCCESS;
3794 isc_result_t eresult = ISC_R_SUCCESS;
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 ||
4021 fctx->type == dns_rdatatype_sig);
4022 /*
4023 * Don't send a response yet - we have
4024 * more rdatasets that still need to
4025 * be validated.
4026 */
4027 dns_db_detachnode(fctx->cache, &node);
4028 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4029 dns_validator_send(ISC_LIST_HEAD(fctx->validators));
4030 goto cleanup_event;
4031 }
4032
4033 answer_response:
4034 /*
4035 * Cache any NS/NSEC records that happened to be validated.
4036 */
4037 result = dns_message_firstname(fctx->rmessage, DNS_SECTION_AUTHORITY);
4038 while (result == ISC_R_SUCCESS) {
4039 name = NULL;
4040 dns_message_currentname(fctx->rmessage, DNS_SECTION_AUTHORITY,
4041 &name);
4042 for (rdataset = ISC_LIST_HEAD(name->list);
4043 rdataset != NULL;
4044 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4045 if ((rdataset->type != dns_rdatatype_ns &&
4046 rdataset->type != dns_rdatatype_nsec) ||
4047 rdataset->trust != dns_trust_secure)
4048 continue;
4049 for (sigrdataset = ISC_LIST_HEAD(name->list);
4050 sigrdataset != NULL;
4051 sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) {
4052 if (sigrdataset->type != dns_rdatatype_rrsig ||
4053 sigrdataset->covers != rdataset->type)
4054 continue;
4055 break;
4056 }
4057 if (sigrdataset == NULL ||
4058 sigrdataset->trust != dns_trust_secure)
4059 continue;
4060 result = dns_db_findnode(fctx->cache, name, ISC_TRUE,
4061 &nsnode);
4062 if (result != ISC_R_SUCCESS)
4063 continue;
4064
4065 result = dns_db_addrdataset(fctx->cache, nsnode, NULL,
4066 now, rdataset, 0, NULL);
4067 if (result == ISC_R_SUCCESS)
4068 result = dns_db_addrdataset(fctx->cache, nsnode,
4069 NULL, now,
4070 sigrdataset, 0,
4071 NULL);
4072 dns_db_detachnode(fctx->cache, &nsnode);
4073 }
4074 result = dns_message_nextname(fctx->rmessage,
4075 DNS_SECTION_AUTHORITY);
4076 }
4077
4078 result = ISC_R_SUCCESS;
4079
4080 /*
4081 * Respond with an answer, positive or negative,
4082 * as opposed to an error. 'node' must be non-NULL.
4083 */
4084
4085 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4086
4087 if (hevent != NULL) {
4088 hevent->result = eresult;
4089 RUNTIME_CHECK(dns_name_copy(vevent->name,
4090 dns_fixedname_name(&hevent->foundname), NULL)
4091 == ISC_R_SUCCESS);
4092 dns_db_attach(fctx->cache, &hevent->db);
4093 dns_db_transfernode(fctx->cache, &node, &hevent->node);
4094 clone_results(fctx);
4095 }
4096
4097 noanswer_response:
4098 if (node != NULL)
4099 dns_db_detachnode(fctx->cache, &node);
4100
4101 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4102
4103 fctx_done(fctx, result, __LINE__); /* Locks bucket. */
4104
4105 cleanup_event:
4106 INSIST(node == NULL);
4107 isc_event_free(&event);
4108 }
4109
4110 static inline isc_result_t
4111 cache_name(fetchctx_t *fctx, dns_name_t *name, dns_adbaddrinfo_t *addrinfo,
4112 isc_stdtime_t now)
4113 {
4114 dns_rdataset_t *rdataset, *sigrdataset;
4115 dns_rdataset_t *addedrdataset, *ardataset, *asigrdataset;
4116 dns_rdataset_t *valrdataset = NULL, *valsigrdataset = NULL;
4117 dns_dbnode_t *node, **anodep;
4118 dns_db_t **adbp;
4119 dns_name_t *aname;
4120 dns_resolver_t *res;
4121 isc_boolean_t need_validation, secure_domain, have_answer;
4122 isc_result_t result, eresult;
4123 dns_fetchevent_t *event;
4124 unsigned int options;
4125 isc_task_t *task;
4126 isc_boolean_t fail;
4127 unsigned int valoptions = 0;
4128
4129 /*
4130 * The appropriate bucket lock must be held.
4131 */
4132
4133 res = fctx->res;
4134 need_validation = ISC_FALSE;
4135 secure_domain = ISC_FALSE;
4136 have_answer = ISC_FALSE;
4137 eresult = ISC_R_SUCCESS;
4138 task = res->buckets[fctx->bucketnum].task;
4139
4140 /*
4141 * Is DNSSEC validation required for this name?
4142 */
4143 if (res->view->enablevalidation) {
4144 result = dns_keytable_issecuredomain(res->view->secroots, name,
4145 &secure_domain);
4146 if (result != ISC_R_SUCCESS)
4147 return (result);
4148
4149 if (!secure_domain && res->view->dlv != NULL) {
4150 valoptions = DNS_VALIDATOR_DLV;
4151 secure_domain = ISC_TRUE;
4152 }
4153 }
4154
4155 if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0)
4156 need_validation = ISC_FALSE;
4157 else
4158 need_validation = secure_domain;
4159
4160 adbp = NULL;
4161 aname = NULL;
4162 anodep = NULL;
4163 ardataset = NULL;
4164 asigrdataset = NULL;
4165 event = NULL;
4166 if ((name->attributes & DNS_NAMEATTR_ANSWER) != 0 &&
4167 !need_validation) {
4168 have_answer = ISC_TRUE;
4169 event = ISC_LIST_HEAD(fctx->events);
4170 if (event != NULL) {
4171 adbp = &event->db;
4172 aname = dns_fixedname_name(&event->foundname);
4173 result = dns_name_copy(name, aname, NULL);
4174 if (result != ISC_R_SUCCESS)
4175 return (result);
4176 anodep = &event->node;
4177 /*
4178 * If this is an ANY, SIG or RRSIG query, we're not
4179 * going to return any rdatasets, unless we encountered
4180 * a CNAME or DNAME as "the answer". In this case,
4181 * we're going to return DNS_R_CNAME or DNS_R_DNAME
4182 * and we must set up the rdatasets.
4183 */
4184 if ((fctx->type != dns_rdatatype_any &&
4185 fctx->type != dns_rdatatype_rrsig &&
4186 fctx->type != dns_rdatatype_sig) ||
4187 (name->attributes & DNS_NAMEATTR_CHAINING) != 0) {
4188 ardataset = event->rdataset;
4189 asigrdataset = event->sigrdataset;
4190 }
4191 }
4192 }
4193
4194 /*
4195 * Find or create the cache node.
4196 */
4197 node = NULL;
4198 result = dns_db_findnode(fctx->cache, name, ISC_TRUE, &node);
4199 if (result != ISC_R_SUCCESS)
4200 return (result);
4201
4202 /*
4203 * Cache or validate each cacheable rdataset.
4204 */
4205 fail = ISC_TF((fctx->res->options & DNS_RESOLVER_CHECKNAMESFAIL) != 0);
4206 for (rdataset = ISC_LIST_HEAD(name->list);
4207 rdataset != NULL;
4208 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4209 if (!CACHE(rdataset))
4210 continue;
4211 if (CHECKNAMES(rdataset)) {
4212 char namebuf[DNS_NAME_FORMATSIZE];
4213 char typebuf[DNS_RDATATYPE_FORMATSIZE];
4214 char classbuf[DNS_RDATATYPE_FORMATSIZE];
4215
4216 dns_name_format(name, namebuf, sizeof(namebuf));
4217 dns_rdatatype_format(rdataset->type, typebuf,
4218 sizeof(typebuf));
4219 dns_rdataclass_format(rdataset->rdclass, classbuf,
4220 sizeof(classbuf));
4221 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
4222 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
4223 "check-names %s %s/%s/%s",
4224 fail ? "failure" : "warning",
4225 namebuf, typebuf, classbuf);
4226 if (fail) {
4227 if (ANSWER(rdataset)) {
4228 dns_db_detachnode(fctx->cache, &node);
4229 return (DNS_R_BADNAME);
4230 }
4231 continue;
4232 }
4233 }
4234
4235 /*
4236 * Enforce the configure maximum cache TTL.
4237 */
4238 if (rdataset->ttl > res->view->maxcachettl)
4239 rdataset->ttl = res->view->maxcachettl;
4240
4241 /*
4242 * If this RRset is in a secure domain, is in bailiwick,
4243 * and is not glue, attempt DNSSEC validation. (We do not
4244 * attempt to validate glue or out-of-bailiwick data--even
4245 * though there might be some performance benefit to doing
4246 * so--because it makes it simpler and safer to ensure that
4247 * records from a secure domain are only cached if validated
4248 * within the context of a query to the domain that owns
4249 * them.)
4250 */
4251 if (secure_domain && rdataset->trust != dns_trust_glue &&
4252 !EXTERNAL(rdataset)) {
4253 dns_trust_t trust;
4254
4255 /*
4256 * RRSIGs are validated as part of validating the
4257 * type they cover.
4258 */
4259 if (rdataset->type == dns_rdatatype_rrsig)
4260 continue;
4261 /*
4262 * Find the SIG for this rdataset, if we have it.
4263 */
4264 for (sigrdataset = ISC_LIST_HEAD(name->list);
4265 sigrdataset != NULL;
4266 sigrdataset = ISC_LIST_NEXT(sigrdataset, link)) {
4267 if (sigrdataset->type == dns_rdatatype_rrsig &&
4268 sigrdataset->covers == rdataset->type)
4269 break;
4270 }
4271 if (sigrdataset == NULL) {
4272 if (!ANSWER(rdataset) && need_validation) {
4273 /*
4274 * Ignore non-answer rdatasets that
4275 * are missing signatures.
4276 */
4277 continue;
4278 }
4279 }
4280
4281 /*
4282 * Normalize the rdataset and sigrdataset TTLs.
4283 */
4284 if (sigrdataset != NULL) {
4285 rdataset->ttl = ISC_MIN(rdataset->ttl,
4286 sigrdataset->ttl);
4287 sigrdataset->ttl = rdataset->ttl;
4288 }
4289
4290 /*
4291 * Cache this rdataset/sigrdataset pair as
4292 * pending data. Track whether it was additional
4293 * or not.
4294 */
4295 if (rdataset->trust == dns_trust_additional)
4296 trust = dns_trust_pending_additional;
4297 else
4298 trust = dns_trust_pending_answer;
4299
4300 rdataset->trust = trust;
4301 if (sigrdataset != NULL)
4302 sigrdataset->trust = trust;
4303 if (!need_validation || !ANSWER(rdataset)) {
4304 addedrdataset = ardataset;
4305 result = dns_db_addrdataset(fctx->cache, node,
4306 NULL, now, rdataset,
4307 0, addedrdataset);
4308 if (result == DNS_R_UNCHANGED) {
4309 result = ISC_R_SUCCESS;
4310 if (!need_validation &&
4311 ardataset != NULL &&
4312 ardataset->type == 0) {
4313 /*
4314 * The answer in the cache is
4315 * better than the answer we
4316 * found, and is a negative
4317 * cache entry, so we must set
4318 * eresult appropriately.
4319 */
4320 if (NXDOMAIN(ardataset))
4321 eresult =
4322 DNS_R_NCACHENXDOMAIN;
4323 else
4324 eresult =
4325 DNS_R_NCACHENXRRSET;
4326 /*
4327 * We have a negative response
4328 * from the cache so don't
4329 * attempt to add the RRSIG
4330 * rrset.
4331 */
4332 continue;
4333 }
4334 }
4335 if (result != ISC_R_SUCCESS)
4336 break;
4337 if (sigrdataset != NULL) {
4338 addedrdataset = asigrdataset;
4339 result = dns_db_addrdataset(fctx->cache,
4340 node, NULL, now,
4341 sigrdataset, 0,
4342 addedrdataset);
4343 if (result == DNS_R_UNCHANGED)
4344 result = ISC_R_SUCCESS;
4345 if (result != ISC_R_SUCCESS)
4346 break;
4347 } else if (!ANSWER(rdataset))
4348 continue;
4349 }
4350
4351 if (ANSWER(rdataset) && need_validation) {
4352 if (fctx->type != dns_rdatatype_any &&
4353 fctx->type != dns_rdatatype_rrsig &&
4354 fctx->type != dns_rdatatype_sig) {
4355 /*
4356 * This is The Answer. We will
4357 * validate it, but first we cache
4358 * the rest of the response - it may
4359 * contain useful keys.
4360 */
4361 INSIST(valrdataset == NULL &&
4362 valsigrdataset == NULL);
4363 valrdataset = rdataset;
4364 valsigrdataset = sigrdataset;
4365 } else {
4366 /*
4367 * This is one of (potentially)
4368 * multiple answers to an ANY
4369 * or SIG query. To keep things
4370 * simple, we just start the
4371 * validator right away rather
4372 * than caching first and
4373 * having to remember which
4374 * rdatasets needed validation.
4375 */
4376 result = valcreate(fctx, addrinfo,
4377 name, rdataset->type,
4378 rdataset,
4379 sigrdataset,
4380 valoptions, task);
4381 /*
4382 * Defer any further validations.
4383 * This prevents multiple validators
4384 * from manipulating fctx->rmessage
4385 * simultaneously.
4386 */
4387 valoptions |= DNS_VALIDATOR_DEFER;
4388 }
4389 } else if (CHAINING(rdataset)) {
4390 if (rdataset->type == dns_rdatatype_cname)
4391 eresult = DNS_R_CNAME;
4392 else {
4393 INSIST(rdataset->type ==
4394 dns_rdatatype_dname);
4395 eresult = DNS_R_DNAME;
4396 }
4397 }
4398 } else if (!EXTERNAL(rdataset)) {
4399 /*
4400 * It's OK to cache this rdataset now.
4401 */
4402 if (ANSWER(rdataset))
4403 addedrdataset = ardataset;
4404 else if (ANSWERSIG(rdataset))
4405 addedrdataset = asigrdataset;
4406 else
4407 addedrdataset = NULL;
4408 if (CHAINING(rdataset)) {
4409 if (rdataset->type == dns_rdatatype_cname)
4410 eresult = DNS_R_CNAME;
4411 else {
4412 INSIST(rdataset->type ==
4413 dns_rdatatype_dname);
4414 eresult = DNS_R_DNAME;
4415 }
4416 }
4417 if (rdataset->trust == dns_trust_glue &&
4418 (rdataset->type == dns_rdatatype_ns ||
4419 (rdataset->type == dns_rdatatype_rrsig &&
4420 rdataset->covers == dns_rdatatype_ns))) {
4421 /*
4422 * If the trust level is 'dns_trust_glue'
4423 * then we are adding data from a referral
4424 * we got while executing the search algorithm.
4425 * New referral data always takes precedence
4426 * over the existing cache contents.
4427 */
4428 options = DNS_DBADD_FORCE;
4429 } else
4430 options = 0;
4431 /*
4432 * Now we can add the rdataset.
4433 */
4434 result = dns_db_addrdataset(fctx->cache,
4435 node, NULL, now,
4436 rdataset,
4437 options,
4438 addedrdataset);
4439 if (result == DNS_R_UNCHANGED) {
4440 if (ANSWER(rdataset) &&
4441 ardataset != NULL &&
4442 ardataset->type == 0) {
4443 /*
4444 * The answer in the cache is better
4445 * than the answer we found, and is
4446 * a negative cache entry, so we
4447 * must set eresult appropriately.
4448 */
4449 if (NXDOMAIN(ardataset))
4450 eresult = DNS_R_NCACHENXDOMAIN;
4451 else
4452 eresult = DNS_R_NCACHENXRRSET;
4453 }
4454 result = ISC_R_SUCCESS;
4455 } else if (result != ISC_R_SUCCESS)
4456 break;
4457 }
4458 }
4459
4460 if (valrdataset != NULL)
4461 result = valcreate(fctx, addrinfo, name, fctx->type,
4462 valrdataset, valsigrdataset, valoptions,
4463 task);
4464
4465 if (result == ISC_R_SUCCESS && have_answer) {
4466 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4467 if (event != NULL) {
4468 /*
4469 * Negative results must be indicated in event->result.
4470 */
4471 if (dns_rdataset_isassociated(event->rdataset) &&
4472 event->rdataset->type == dns_rdatatype_none) {
4473 INSIST(eresult == DNS_R_NCACHENXDOMAIN ||
4474 eresult == DNS_R_NCACHENXRRSET);
4475 }
4476 event->result = eresult;
4477 dns_db_attach(fctx->cache, adbp);
4478 dns_db_transfernode(fctx->cache, &node, anodep);
4479 clone_results(fctx);
4480 }
4481 }
4482
4483 if (node != NULL)
4484 dns_db_detachnode(fctx->cache, &node);
4485
4486 return (result);
4487 }
4488
4489 static inline isc_result_t
4490 cache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_stdtime_t now)
4491 {
4492 isc_result_t result;
4493 dns_section_t section;
4494 dns_name_t *name;
4495
4496 FCTXTRACE("cache_message");
4497
4498 fctx->attributes &= ~FCTX_ATTR_WANTCACHE;
4499
4500 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4501
4502 for (section = DNS_SECTION_ANSWER;
4503 section <= DNS_SECTION_ADDITIONAL;
4504 section++) {
4505 result = dns_message_firstname(fctx->rmessage, section);
4506 while (result == ISC_R_SUCCESS) {
4507 name = NULL;
4508 dns_message_currentname(fctx->rmessage, section,
4509 &name);
4510 if ((name->attributes & DNS_NAMEATTR_CACHE) != 0) {
4511 result = cache_name(fctx, name, addrinfo, now);
4512 if (result != ISC_R_SUCCESS)
4513 break;
4514 }
4515 result = dns_message_nextname(fctx->rmessage, section);
4516 }
4517 if (result != ISC_R_NOMORE)
4518 break;
4519 }
4520 if (result == ISC_R_NOMORE)
4521 result = ISC_R_SUCCESS;
4522
4523 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
4524
4525 return (result);
4526 }
4527
4528 /*
4529 * Do what dns_ncache_add() does, and then compute an appropriate eresult.
4530 */
4531 static isc_result_t
4532 ncache_adderesult(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
4533 dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
4534 dns_rdataset_t *ardataset,
4535 isc_result_t *eresultp)
4536 {
4537 isc_result_t result;
4538 dns_rdataset_t rdataset;
4539
4540 if (ardataset == NULL) {
4541 dns_rdataset_init(&rdataset);
4542 ardataset = &rdataset;
4543 }
4544 result = dns_ncache_add(message, cache, node, covers, now,
4545 maxttl, ardataset);
4546 if (result == DNS_R_UNCHANGED || result == ISC_R_SUCCESS) {
4547 /*
4548 * If the cache now contains a negative entry and we
4549 * care about whether it is DNS_R_NCACHENXDOMAIN or
4550 * DNS_R_NCACHENXRRSET then extract it.
4551 */
4552 if (ardataset->type == 0) {
4553 /*
4554 * The cache data is a negative cache entry.
4555 */
4556 if (NXDOMAIN(ardataset))
4557 *eresultp = DNS_R_NCACHENXDOMAIN;
4558 else
4559 *eresultp = DNS_R_NCACHENXRRSET;
4560 } else {
4561 /*
4562 * Either we don't care about the nature of the
4563 * cache rdataset (because no fetch is interested
4564 * in the outcome), or the cache rdataset is not
4565 * a negative cache entry. Whichever case it is,
4566 * we can return success.
4567 *
4568 * XXXRTH There's a CNAME/DNAME problem here.
4569 */
4570 *eresultp = ISC_R_SUCCESS;
4571 }
4572 result = ISC_R_SUCCESS;
4573 }
4574 if (ardataset == &rdataset && dns_rdataset_isassociated(ardataset))
4575 dns_rdataset_disassociate(ardataset);
4576
4577 return (result);
4578 }
4579
4580 static inline isc_result_t
4581 ncache_message(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
4582 dns_rdatatype_t covers, isc_stdtime_t now)
4583 {
4584 isc_result_t result, eresult;
4585 dns_name_t *name;
4586 dns_resolver_t *res;
4587 dns_db_t **adbp;
4588 dns_dbnode_t *node, **anodep;
4589 dns_rdataset_t *ardataset;
4590 isc_boolean_t need_validation, secure_domain;
4591 dns_name_t *aname;
4592 dns_fetchevent_t *event;
4593 isc_uint32_t ttl;
4594 unsigned int valoptions = 0;
4595
4596 FCTXTRACE("ncache_message");
4597
4598 fctx->attributes &= ~FCTX_ATTR_WANTNCACHE;
4599
4600 res = fctx->res;
4601 need_validation = ISC_FALSE;
4602 secure_domain = ISC_FALSE;
4603 eresult = ISC_R_SUCCESS;
4604 name = &fctx->name;
4605 node = NULL;
4606
4607 /*
4608 * XXXMPA remove when we follow cnames and adjust the setting
4609 * of FCTX_ATTR_WANTNCACHE in noanswer_response().
4610 */
4611 INSIST(fctx->rmessage->counts[DNS_SECTION_ANSWER] == 0);
4612
4613 /*
4614 * Is DNSSEC validation required for this name?
4615 */
4616 if (fctx->res->view->enablevalidation) {
4617 result = dns_keytable_issecuredomain(res->view->secroots, name,
4618 &secure_domain);
4619 if (result != ISC_R_SUCCESS)
4620 return (result);
4621
4622 if (!secure_domain && res->view->dlv != NULL) {
4623 valoptions = DNS_VALIDATOR_DLV;
4624 secure_domain = ISC_TRUE;
4625 }
4626 }
4627
4628 if ((fctx->options & DNS_FETCHOPT_NOVALIDATE) != 0)
4629 need_validation = ISC_FALSE;
4630 else
4631 need_validation = secure_domain;
4632
4633 if (secure_domain) {
4634 /*
4635 * Mark all rdatasets as pending.
4636 */
4637 dns_rdataset_t *trdataset;
4638 dns_name_t *tname;
4639
4640 result = dns_message_firstname(fctx->rmessage,
4641 DNS_SECTION_AUTHORITY);
4642 while (result == ISC_R_SUCCESS) {
4643 tname = NULL;
4644 dns_message_currentname(fctx->rmessage,
4645 DNS_SECTION_AUTHORITY,
4646 &tname);
4647 for (trdataset = ISC_LIST_HEAD(tname->list);
4648 trdataset != NULL;
4649 trdataset = ISC_LIST_NEXT(trdataset, link))
4650 trdataset->trust = dns_trust_pending_answer;
4651 result = dns_message_nextname(fctx->rmessage,
4652 DNS_SECTION_AUTHORITY);
4653 }
4654 if (result != ISC_R_NOMORE)
4655 return (result);
4656
4657 }
4658
4659 if (need_validation) {
4660 /*
4661 * Do negative response validation.
4662 */
4663 result = valcreate(fctx, addrinfo, name, fctx->type,
4664 NULL, NULL, valoptions,
4665 res->buckets[fctx->bucketnum].task);
4666 /*
4667 * If validation is necessary, return now. Otherwise continue
4668 * to process the message, letting the validation complete
4669 * in its own good time.
4670 */
4671 return (result);
4672 }
4673
4674 LOCK(&res->buckets[fctx->bucketnum].lock);
4675
4676 adbp = NULL;
4677 aname = NULL;
4678 anodep = NULL;
4679 ardataset = NULL;
4680 if (!HAVE_ANSWER(fctx)) {
4681 event = ISC_LIST_HEAD(fctx->events);
4682 if (event != NULL) {
4683 adbp = &event->db;
4684 aname = dns_fixedname_name(&event->foundname);
4685 result = dns_name_copy(name, aname, NULL);
4686 if (result != ISC_R_SUCCESS)
4687 goto unlock;
4688 anodep = &event->node;
4689 ardataset = event->rdataset;
4690 }
4691 } else
4692 event = NULL;
4693
4694 result = dns_db_findnode(fctx->cache, name, ISC_TRUE, &node);
4695 if (result != ISC_R_SUCCESS)
4696 goto unlock;
4697
4698 /*
4699 * If we are asking for a SOA record set the cache time
4700 * to zero to facilitate locating the containing zone of
4701 * a arbitrary zone.
4702 */
4703 ttl = fctx->res->view->maxncachettl;
4704 if (fctx->type == dns_rdatatype_soa &&
4705 covers == dns_rdatatype_any &&
4706 fctx->res->zero_no_soa_ttl)
4707 ttl = 0;
4708
4709 result = ncache_adderesult(fctx->rmessage, fctx->cache, node,
4710 covers, now, ttl, ardataset, &eresult);
4711 if (result != ISC_R_SUCCESS)
4712 goto unlock;
4713
4714 if (!HAVE_ANSWER(fctx)) {
4715 fctx->attributes |= FCTX_ATTR_HAVEANSWER;
4716 if (event != NULL) {
4717 event->result = eresult;
4718 dns_db_attach(fctx->cache, adbp);
4719 dns_db_transfernode(fctx->cache, &node, anodep);
4720 clone_results(fctx);
4721 }
4722 }
4723
4724 unlock:
4725 UNLOCK(&res->buckets[fctx->bucketnum].lock);
4726
4727 if (node != NULL)
4728 dns_db_detachnode(fctx->cache, &node);
4729
4730 return (result);
4731 }
4732
4733 static inline void
4734 mark_related(dns_name_t *name, dns_rdataset_t *rdataset,
4735 isc_boolean_t external, isc_boolean_t gluing)
4736 {
4737 name->attributes |= DNS_NAMEATTR_CACHE;
4738 if (gluing) {
4739 rdataset->trust = dns_trust_glue;
4740 /*
4741 * Glue with 0 TTL causes problems. We force the TTL to
4742 * 1 second to prevent this.
4743 */
4744 if (rdataset->ttl == 0)
4745 rdataset->ttl = 1;
4746 } else
4747 rdataset->trust = dns_trust_additional;
4748 /*
4749 * Avoid infinite loops by only marking new rdatasets.
4750 */
4751 if (!CACHE(rdataset)) {
4752 name->attributes |= DNS_NAMEATTR_CHASE;
4753 rdataset->attributes |= DNS_RDATASETATTR_CHASE;
4754 }
4755 rdataset->attributes |= DNS_RDATASETATTR_CACHE;
4756 if (external)
4757 rdataset->attributes |= DNS_RDATASETATTR_EXTERNAL;
4758 }
4759
4760 static isc_result_t
4761 check_related(void *arg, dns_name_t *addname, dns_rdatatype_t type) {
4762 fetchctx_t *fctx = arg;
4763 isc_result_t result;
4764 dns_name_t *name;
4765 dns_rdataset_t *rdataset;
4766 isc_boolean_t external;
4767 dns_rdatatype_t rtype;
4768 isc_boolean_t gluing;
4769
4770 REQUIRE(VALID_FCTX(fctx));
4771
4772 if (GLUING(fctx))
4773 gluing = ISC_TRUE;
4774 else
4775 gluing = ISC_FALSE;
4776 name = NULL;
4777 rdataset = NULL;
4778 result = dns_message_findname(fctx->rmessage, DNS_SECTION_ADDITIONAL,
4779 addname, dns_rdatatype_any, 0, &name,
4780 NULL);
4781 if (result == ISC_R_SUCCESS) {
4782 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
4783 if (type == dns_rdatatype_a) {
4784 for (rdataset = ISC_LIST_HEAD(name->list);
4785 rdataset != NULL;
4786 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4787 if (rdataset->type == dns_rdatatype_rrsig)
4788 rtype = rdataset->covers;
4789 else
4790 rtype = rdataset->type;
4791 if (rtype == dns_rdatatype_a ||
4792 rtype == dns_rdatatype_aaaa)
4793 mark_related(name, rdataset, external,
4794 gluing);
4795 }
4796 } else {
4797 result = dns_message_findtype(name, type, 0,
4798 &rdataset);
4799 if (result == ISC_R_SUCCESS) {
4800 mark_related(name, rdataset, external, gluing);
4801 /*
4802 * Do we have its SIG too?
4803 */
4804 rdataset = NULL;
4805 result = dns_message_findtype(name,
4806 dns_rdatatype_rrsig,
4807 type, &rdataset);
4808 if (result == ISC_R_SUCCESS)
4809 mark_related(name, rdataset, external,
4810 gluing);
4811 }
4812 }
4813 }
4814
4815 return (ISC_R_SUCCESS);
4816 }
4817
4818 static void
4819 chase_additional(fetchctx_t *fctx) {
4820 isc_boolean_t rescan;
4821 dns_section_t section = DNS_SECTION_ADDITIONAL;
4822 isc_result_t result;
4823
4824 again:
4825 rescan = ISC_FALSE;
4826
4827 for (result = dns_message_firstname(fctx->rmessage, section);
4828 result == ISC_R_SUCCESS;
4829 result = dns_message_nextname(fctx->rmessage, section)) {
4830 dns_name_t *name = NULL;
4831 dns_rdataset_t *rdataset;
4832 dns_message_currentname(fctx->rmessage, DNS_SECTION_ADDITIONAL,
4833 &name);
4834 if ((name->attributes & DNS_NAMEATTR_CHASE) == 0)
4835 continue;
4836 name->attributes &= ~DNS_NAMEATTR_CHASE;
4837 for (rdataset = ISC_LIST_HEAD(name->list);
4838 rdataset != NULL;
4839 rdataset = ISC_LIST_NEXT(rdataset, link)) {
4840 if (CHASE(rdataset)) {
4841 rdataset->attributes &= ~DNS_RDATASETATTR_CHASE;
4842 (void)dns_rdataset_additionaldata(rdataset,
4843 check_related,
4844 fctx);
4845 rescan = ISC_TRUE;
4846 }
4847 }
4848 }
4849 if (rescan)
4850 goto again;
4851 }
4852
4853 static inline isc_result_t
4854 cname_target(dns_rdataset_t *rdataset, dns_name_t *tname) {
4855 isc_result_t result;
4856 dns_rdata_t rdata = DNS_RDATA_INIT;
4857 dns_rdata_cname_t cname;
4858
4859 result = dns_rdataset_first(rdataset);
4860 if (result != ISC_R_SUCCESS)
4861 return (result);
4862 dns_rdataset_current(rdataset, &rdata);
4863 result = dns_rdata_tostruct(&rdata, &cname, NULL);
4864 if (result != ISC_R_SUCCESS)
4865 return (result);
4866 dns_name_init(tname, NULL);
4867 dns_name_clone(&cname.cname, tname);
4868 dns_rdata_freestruct(&cname);
4869
4870 return (ISC_R_SUCCESS);
4871 }
4872
4873 static inline isc_result_t
4874 dname_target(dns_rdataset_t *rdataset, dns_name_t *qname, dns_name_t *oname,
4875 dns_fixedname_t *fixeddname)
4876 {
4877 isc_result_t result;
4878 dns_rdata_t rdata = DNS_RDATA_INIT;
4879 unsigned int nlabels;
4880 int order;
4881 dns_namereln_t namereln;
4882 dns_rdata_dname_t dname;
4883 dns_fixedname_t prefix;
4884
4885 /*
4886 * Get the target name of the DNAME.
4887 */
4888
4889 result = dns_rdataset_first(rdataset);
4890 if (result != ISC_R_SUCCESS)
4891 return (result);
4892 dns_rdataset_current(rdataset, &rdata);
4893 result = dns_rdata_tostruct(&rdata, &dname, NULL);
4894 if (result != ISC_R_SUCCESS)
4895 return (result);
4896
4897 /*
4898 * Get the prefix of qname.
4899 */
4900 namereln = dns_name_fullcompare(qname, oname, &order, &nlabels);
4901 if (namereln != dns_namereln_subdomain) {
4902 dns_rdata_freestruct(&dname);
4903 return (DNS_R_FORMERR);
4904 }
4905 dns_fixedname_init(&prefix);
4906 dns_name_split(qname, nlabels, dns_fixedname_name(&prefix), NULL);
4907 dns_fixedname_init(fixeddname);
4908 result = dns_name_concatenate(dns_fixedname_name(&prefix),
4909 &dname.dname,
4910 dns_fixedname_name(fixeddname), NULL);
4911 dns_rdata_freestruct(&dname);
4912 return (result);
4913 }
4914
4915 /*
4916 * Handle a no-answer response (NXDOMAIN, NXRRSET, or referral).
4917 * If bind8_ns_resp is ISC_TRUE, this is a suspected BIND 8
4918 * response to an NS query that should be treated as a referral
4919 * even though the NS records occur in the answer section
4920 * rather than the authority section.
4921 */
4922 static isc_result_t
4923 noanswer_response(fetchctx_t *fctx, dns_name_t *oqname,
4924 isc_boolean_t bind8_ns_resp)
4925 {
4926 isc_result_t result;
4927 dns_message_t *message;
4928 dns_name_t *name, *qname, *ns_name, *soa_name, *ds_name;
4929 dns_rdataset_t *rdataset, *ns_rdataset;
4930 isc_boolean_t aa, negative_response;
4931 dns_rdatatype_t type;
4932 dns_section_t section =
4933 bind8_ns_resp ? DNS_SECTION_ANSWER : DNS_SECTION_AUTHORITY;
4934
4935 FCTXTRACE("noanswer_response");
4936
4937 message = fctx->rmessage;
4938
4939 /*
4940 * Setup qname.
4941 */
4942 if (oqname == NULL) {
4943 /*
4944 * We have a normal, non-chained negative response or
4945 * referral.
4946 */
4947 if ((message->flags & DNS_MESSAGEFLAG_AA) != 0)
4948 aa = ISC_TRUE;
4949 else
4950 aa = ISC_FALSE;
4951 qname = &fctx->name;
4952 } else {
4953 /*
4954 * We're being invoked by answer_response() after it has
4955 * followed a CNAME/DNAME chain.
4956 */
4957 qname = oqname;
4958 aa = ISC_FALSE;
4959 /*
4960 * If the current qname is not a subdomain of the query
4961 * domain, there's no point in looking at the authority
4962 * section without doing DNSSEC validation.
4963 *
4964 * Until we do that validation, we'll just return success
4965 * in this case.
4966 */
4967 if (!dns_name_issubdomain(qname, &fctx->domain))
4968 return (ISC_R_SUCCESS);
4969 }
4970
4971 /*
4972 * We have to figure out if this is a negative response, or a
4973 * referral.
4974 */
4975
4976 /*
4977 * Sometimes we can tell if its a negative response by looking at
4978 * the message header.
4979 */
4980 negative_response = ISC_FALSE;
4981 if (message->rcode == dns_rcode_nxdomain ||
4982 (message->counts[DNS_SECTION_ANSWER] == 0 &&
4983 message->counts[DNS_SECTION_AUTHORITY] == 0))
4984 negative_response = ISC_TRUE;
4985
4986 /*
4987 * Process the authority section.
4988 */
4989 ns_name = NULL;
4990 ns_rdataset = NULL;
4991 soa_name = NULL;
4992 ds_name = NULL;
4993 result = dns_message_firstname(message, section);
4994 while (result == ISC_R_SUCCESS) {
4995 name = NULL;
4996 dns_message_currentname(message, section, &name);
4997 if (dns_name_issubdomain(name, &fctx->domain)) {
4998 /*
4999 * Look for NS/SOA RRsets first.
5000 */
5001 for (rdataset = ISC_LIST_HEAD(name->list);
5002 rdataset != NULL;
5003 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5004 type = rdataset->type;
5005 if (type == dns_rdatatype_rrsig)
5006 type = rdataset->covers;
5007 if (((type == dns_rdatatype_ns ||
5008 type == dns_rdatatype_soa) &&
5009 !dns_name_issubdomain(qname, name)))
5010 return (DNS_R_FORMERR);
5011 if (type == dns_rdatatype_ns) {
5012 /*
5013 * NS or RRSIG NS.
5014 *
5015 * Only one set of NS RRs is allowed.
5016 */
5017 if (rdataset->type ==
5018 dns_rdatatype_ns) {
5019 if (ns_name != NULL &&
5020 name != ns_name)
5021 return (DNS_R_FORMERR);
5022 ns_name = name;
5023 ns_rdataset = rdataset;
5024 }
5025 name->attributes |=
5026 DNS_NAMEATTR_CACHE;
5027 rdataset->attributes |=
5028 DNS_RDATASETATTR_CACHE;
5029 rdataset->trust = dns_trust_glue;
5030 }
5031 if (type == dns_rdatatype_soa) {
5032 /*
5033 * SOA, or RRSIG SOA.
5034 *
5035 * Only one SOA is allowed.
5036 */
5037 if (rdataset->type ==
5038 dns_rdatatype_soa) {
5039 if (soa_name != NULL &&
5040 name != soa_name)
5041 return (DNS_R_FORMERR);
5042 soa_name = name;
5043 }
5044 name->attributes |=
5045 DNS_NAMEATTR_NCACHE;
5046 rdataset->attributes |=
5047 DNS_RDATASETATTR_NCACHE;
5048 if (aa)
5049 rdataset->trust =
5050 dns_trust_authauthority;
5051 else
5052 rdataset->trust =
5053 dns_trust_additional;
5054 }
5055 }
5056 }
5057 result = dns_message_nextname(message, section);
5058 if (result == ISC_R_NOMORE)
5059 break;
5060 else if (result != ISC_R_SUCCESS)
5061 return (result);
5062 }
5063
5064 /*
5065 * A negative response has a SOA record (Type 2)
5066 * and a optional NS RRset (Type 1) or it has neither
5067 * a SOA or a NS RRset (Type 3, handled above) or
5068 * rcode is NXDOMAIN (handled above) in which case
5069 * the NS RRset is allowed (Type 4).
5070 */
5071 if (soa_name != NULL)
5072 negative_response = ISC_TRUE;
5073
5074 result = dns_message_firstname(message, section);
5075 while (result == ISC_R_SUCCESS) {
5076 name = NULL;
5077 dns_message_currentname(message, section, &name);
5078 if (dns_name_issubdomain(name, &fctx->domain)) {
5079 for (rdataset = ISC_LIST_HEAD(name->list);
5080 rdataset != NULL;
5081 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5082 type = rdataset->type;
5083 if (type == dns_rdatatype_rrsig)
5084 type = rdataset->covers;
5085 if (type == dns_rdatatype_nsec) {
5086 /*
5087 * NSEC or RRSIG NSEC.
5088 */
5089 if (negative_response) {
5090 name->attributes |=
5091 DNS_NAMEATTR_NCACHE;
5092 rdataset->attributes |=
5093 DNS_RDATASETATTR_NCACHE;
5094 } else {
5095 name->attributes |=
5096 DNS_NAMEATTR_CACHE;
5097 rdataset->attributes |=
5098 DNS_RDATASETATTR_CACHE;
5099 }
5100 if (aa)
5101 rdataset->trust =
5102 dns_trust_authauthority;
5103 else
5104 rdataset->trust =
5105 dns_trust_additional;
5106 /*
5107 * No additional data needs to be
5108 * marked.
5109 */
5110 } else if (type == dns_rdatatype_ds) {
5111 /*
5112 * DS or SIG DS.
5113 *
5114 * These should only be here if
5115 * this is a referral, and there
5116 * should only be one DS.
5117 */
5118 if (ns_name == NULL)
5119 return (DNS_R_FORMERR);
5120 if (rdataset->type ==
5121 dns_rdatatype_ds) {
5122 if (ds_name != NULL &&
5123 name != ds_name)
5124 return (DNS_R_FORMERR);
5125 ds_name = name;
5126 }
5127 name->attributes |=
5128 DNS_NAMEATTR_CACHE;
5129 rdataset->attributes |=
5130 DNS_RDATASETATTR_CACHE;
5131 if (aa)
5132 rdataset->trust =
5133 dns_trust_authauthority;
5134 else
5135 rdataset->trust =
5136 dns_trust_additional;
5137 }
5138 }
5139 }
5140 result = dns_message_nextname(message, section);
5141 if (result == ISC_R_NOMORE)
5142 break;
5143 else if (result != ISC_R_SUCCESS)
5144 return (result);
5145 }
5146
5147 /*
5148 * Trigger lookups for DNS nameservers.
5149 */
5150 if (negative_response && message->rcode == dns_rcode_noerror &&
5151 fctx->type == dns_rdatatype_ds && soa_name != NULL &&
5152 dns_name_equal(soa_name, qname) &&
5153 !dns_name_equal(qname, dns_rootname))
5154 return (DNS_R_CHASEDSSERVERS);
5155
5156 /*
5157 * Did we find anything?
5158 */
5159 if (!negative_response && ns_name == NULL) {
5160 /*
5161 * Nope.
5162 */
5163 if (oqname != NULL) {
5164 /*
5165 * We've already got a partial CNAME/DNAME chain,
5166 * and haven't found else anything useful here, but
5167 * no error has occurred since we have an answer.
5168 */
5169 return (ISC_R_SUCCESS);
5170 } else {
5171 /*
5172 * The responder is insane.
5173 */
5174 return (DNS_R_FORMERR);
5175 }
5176 }
5177
5178 /*
5179 * If we found both NS and SOA, they should be the same name.
5180 */
5181 if (ns_name != NULL && soa_name != NULL && ns_name != soa_name)
5182 return (DNS_R_FORMERR);
5183
5184 /*
5185 * Do we have a referral? (We only want to follow a referral if
5186 * we're not following a chain.)
5187 */
5188 if (!negative_response && ns_name != NULL && oqname == NULL) {
5189 /*
5190 * We already know ns_name is a subdomain of fctx->domain.
5191 * If ns_name is equal to fctx->domain, we're not making
5192 * progress. We return DNS_R_FORMERR so that we'll keep
5193 * trying other servers.
5194 */
5195 if (dns_name_equal(ns_name, &fctx->domain))
5196 return (DNS_R_FORMERR);
5197
5198 /*
5199 * If the referral name is not a parent of the query
5200 * name, consider the responder insane.
5201 */
5202 if (! dns_name_issubdomain(&fctx->name, ns_name)) {
5203 FCTXTRACE("referral to non-parent");
5204 return (DNS_R_FORMERR);
5205 }
5206
5207 /*
5208 * Mark any additional data related to this rdataset.
5209 * It's important that we do this before we change the
5210 * query domain.
5211 */
5212 INSIST(ns_rdataset != NULL);
5213 fctx->attributes |= FCTX_ATTR_GLUING;
5214 (void)dns_rdataset_additionaldata(ns_rdataset, check_related,
5215 fctx);
5216 fctx->attributes &= ~FCTX_ATTR_GLUING;
5217 /*
5218 * NS rdatasets with 0 TTL cause problems.
5219 * dns_view_findzonecut() will not find them when we
5220 * try to follow the referral, and we'll SERVFAIL
5221 * because the best nameservers are now above QDOMAIN.
5222 * We force the TTL to 1 second to prevent this.
5223 */
5224 if (ns_rdataset->ttl == 0)
5225 ns_rdataset->ttl = 1;
5226 /*
5227 * Set the current query domain to the referral name.
5228 *
5229 * XXXRTH We should check if we're in forward-only mode, and
5230 * if so we should bail out.
5231 */
5232 INSIST(dns_name_countlabels(&fctx->domain) > 0);
5233 dns_name_free(&fctx->domain,
5234 fctx->res->buckets[fctx->bucketnum].mctx);
5235 if (dns_rdataset_isassociated(&fctx->nameservers))
5236 dns_rdataset_disassociate(&fctx->nameservers);
5237 dns_name_init(&fctx->domain, NULL);
5238 result = dns_name_dup(ns_name,
5239 fctx->res->buckets[fctx->bucketnum].mctx,
5240 &fctx->domain);
5241 if (result != ISC_R_SUCCESS)
5242 return (result);
5243 fctx->attributes |= FCTX_ATTR_WANTCACHE;
5244 return (DNS_R_DELEGATION);
5245 }
5246
5247 /*
5248 * Since we're not doing a referral, we don't want to cache any
5249 * NS RRs we may have found.
5250 */
5251 if (ns_name != NULL)
5252 ns_name->attributes &= ~DNS_NAMEATTR_CACHE;
5253
5254 if (negative_response && oqname == NULL)
5255 fctx->attributes |= FCTX_ATTR_WANTNCACHE;
5256
5257 return (ISC_R_SUCCESS);
5258 }
5259
5260 static isc_result_t
5261 answer_response(fetchctx_t *fctx) {
5262 isc_result_t result;
5263 dns_message_t *message;
5264 dns_name_t *name, *qname, tname;
5265 dns_rdataset_t *rdataset;
5266 isc_boolean_t done, external, chaining, aa, found, want_chaining;
5267 isc_boolean_t have_answer, found_cname, found_type, wanted_chaining;
5268 unsigned int aflag;
5269 dns_rdatatype_t type;
5270 dns_fixedname_t dname, fqname;
5271
5272 FCTXTRACE("answer_response");
5273
5274 message = fctx->rmessage;
5275
5276 /*
5277 * Examine the answer section, marking those rdatasets which are
5278 * part of the answer and should be cached.
5279 */
5280
5281 done = ISC_FALSE;
5282 found_cname = ISC_FALSE;
5283 found_type = ISC_FALSE;
5284 chaining = ISC_FALSE;
5285 have_answer = ISC_FALSE;
5286 want_chaining = ISC_FALSE;
5287 if ((message->flags & DNS_MESSAGEFLAG_AA) != 0)
5288 aa = ISC_TRUE;
5289 else
5290 aa = ISC_FALSE;
5291 qname = &fctx->name;
5292 type = fctx->type;
5293 result = dns_message_firstname(message, DNS_SECTION_ANSWER);
5294 while (!done && result == ISC_R_SUCCESS) {
5295 name = NULL;
5296 dns_message_currentname(message, DNS_SECTION_ANSWER, &name);
5297 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
5298 if (dns_name_equal(name, qname)) {
5299 wanted_chaining = ISC_FALSE;
5300 for (rdataset = ISC_LIST_HEAD(name->list);
5301 rdataset != NULL;
5302 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5303 found = ISC_FALSE;
5304 want_chaining = ISC_FALSE;
5305 aflag = 0;
5306 if (rdataset->type == type && !found_cname) {
5307 /*
5308 * We've found an ordinary answer.
5309 */
5310 found = ISC_TRUE;
5311 found_type = ISC_TRUE;
5312 done = ISC_TRUE;
5313 aflag = DNS_RDATASETATTR_ANSWER;
5314 } else if (type == dns_rdatatype_any) {
5315 /*
5316 * We've found an answer matching
5317 * an ANY query. There may be
5318 * more.
5319 */
5320 found = ISC_TRUE;
5321 aflag = DNS_RDATASETATTR_ANSWER;
5322 } else if (rdataset->type == dns_rdatatype_rrsig
5323 && rdataset->covers == type
5324 && !found_cname) {
5325 /*
5326 * We've found a signature that
5327 * covers the type we're looking for.
5328 */
5329 found = ISC_TRUE;
5330 found_type = ISC_TRUE;
5331 aflag = DNS_RDATASETATTR_ANSWERSIG;
5332 } else if (rdataset->type ==
5333 dns_rdatatype_cname
5334 && !found_type) {
5335 /*
5336 * We're looking for something else,
5337 * but we found a CNAME.
5338 *
5339 * Getting a CNAME response for some
5340 * query types is an error.
5341 */
5342 if (type == dns_rdatatype_rrsig ||
5343 type == dns_rdatatype_dnskey ||
5344 type == dns_rdatatype_nsec)
5345 return (DNS_R_FORMERR);
5346 found = ISC_TRUE;
5347 found_cname = ISC_TRUE;
5348 want_chaining = ISC_TRUE;
5349 aflag = DNS_RDATASETATTR_ANSWER;
5350 result = cname_target(rdataset,
5351 &tname);
5352 if (result != ISC_R_SUCCESS)
5353 return (result);
5354 } else if (rdataset->type == dns_rdatatype_rrsig
5355 && rdataset->covers ==
5356 dns_rdatatype_cname
5357 && !found_type) {
5358 /*
5359 * We're looking for something else,
5360 * but we found a SIG CNAME.
5361 */
5362 found = ISC_TRUE;
5363 found_cname = ISC_TRUE;
5364 aflag = DNS_RDATASETATTR_ANSWERSIG;
5365 }
5366
5367 if (found) {
5368 /*
5369 * We've found an answer to our
5370 * question.
5371 */
5372 name->attributes |=
5373 DNS_NAMEATTR_CACHE;
5374 rdataset->attributes |=
5375 DNS_RDATASETATTR_CACHE;
5376 rdataset->trust = dns_trust_answer;
5377 if (!chaining) {
5378 /*
5379 * This data is "the" answer
5380 * to our question only if
5381 * we're not chaining (i.e.
5382 * if we haven't followed
5383 * a CNAME or DNAME).
5384 */
5385 INSIST(!external);
5386 if (aflag ==
5387 DNS_RDATASETATTR_ANSWER)
5388 have_answer = ISC_TRUE;
5389 name->attributes |=
5390 DNS_NAMEATTR_ANSWER;
5391 rdataset->attributes |= aflag;
5392 if (aa)
5393 rdataset->trust =
5394 dns_trust_authanswer;
5395 } else if (external) {
5396 /*
5397 * This data is outside of
5398 * our query domain, and
5399 * may not be cached.
5400 */
5401 rdataset->attributes |=
5402 DNS_RDATASETATTR_EXTERNAL;
5403 }
5404
5405 /*
5406 * Mark any additional data related
5407 * to this rdataset.
5408 */
5409 (void)dns_rdataset_additionaldata(
5410 rdataset,
5411 check_related,
5412 fctx);
5413
5414 /*
5415 * CNAME chaining.
5416 */
5417 if (want_chaining) {
5418 wanted_chaining = ISC_TRUE;
5419 name->attributes |=
5420 DNS_NAMEATTR_CHAINING;
5421 rdataset->attributes |=
5422 DNS_RDATASETATTR_CHAINING;
5423 qname = &tname;
5424 }
5425 }
5426 /*
5427 * We could add an "else" clause here and
5428 * log that we're ignoring this rdataset.
5429 */
5430 }
5431 /*
5432 * If wanted_chaining is true, we've done
5433 * some chaining as the result of processing
5434 * this node, and thus we need to set
5435 * chaining to true.
5436 *
5437 * We don't set chaining inside of the
5438 * rdataset loop because doing that would
5439 * cause us to ignore the signatures of
5440 * CNAMEs.
5441 */
5442 if (wanted_chaining)
5443 chaining = ISC_TRUE;
5444 } else {
5445 /*
5446 * Look for a DNAME (or its SIG). Anything else is
5447 * ignored.
5448 */
5449 wanted_chaining = ISC_FALSE;
5450 for (rdataset = ISC_LIST_HEAD(name->list);
5451 rdataset != NULL;
5452 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5453 isc_boolean_t found_dname = ISC_FALSE;
5454 found = ISC_FALSE;
5455 aflag = 0;
5456 if (rdataset->type == dns_rdatatype_dname) {
5457 /*
5458 * We're looking for something else,
5459 * but we found a DNAME.
5460 *
5461 * If we're not chaining, then the
5462 * DNAME should not be external.
5463 */
5464 if (!chaining && external)
5465 return (DNS_R_FORMERR);
5466 found = ISC_TRUE;
5467 want_chaining = ISC_TRUE;
5468 aflag = DNS_RDATASETATTR_ANSWER;
5469 result = dname_target(rdataset,
5470 qname, name,
5471 &dname);
5472 if (result == ISC_R_NOSPACE) {
5473 /*
5474 * We can't construct the
5475 * DNAME target. Do not
5476 * try to continue.
5477 */
5478 want_chaining = ISC_FALSE;
5479 } else if (result != ISC_R_SUCCESS)
5480 return (result);
5481 else
5482 found_dname = ISC_TRUE;
5483 } else if (rdataset->type == dns_rdatatype_rrsig
5484 && rdataset->covers ==
5485 dns_rdatatype_dname) {
5486 /*
5487 * We've found a signature that
5488 * covers the DNAME.
5489 */
5490 found = ISC_TRUE;
5491 aflag = DNS_RDATASETATTR_ANSWERSIG;
5492 }
5493
5494 if (found) {
5495 /*
5496 * We've found an answer to our
5497 * question.
5498 */
5499 name->attributes |=
5500 DNS_NAMEATTR_CACHE;
5501 rdataset->attributes |=
5502 DNS_RDATASETATTR_CACHE;
5503 rdataset->trust = dns_trust_answer;
5504 if (!chaining) {
5505 /*
5506 * This data is "the" answer
5507 * to our question only if
5508 * we're not chaining.
5509 */
5510 INSIST(!external);
5511 if (aflag ==
5512 DNS_RDATASETATTR_ANSWER)
5513 have_answer = ISC_TRUE;
5514 name->attributes |=
5515 DNS_NAMEATTR_ANSWER;
5516 rdataset->attributes |= aflag;
5517 if (aa)
5518 rdataset->trust =
5519 dns_trust_authanswer;
5520 } else if (external) {
5521 rdataset->attributes |=
5522 DNS_RDATASETATTR_EXTERNAL;
5523 }
5524
5525 /*
5526 * DNAME chaining.
5527 */
5528 if (found_dname) {
5529 /*
5530 * Copy the dname into the
5531 * qname fixed name.
5532 *
5533 * Although we check for
5534 * failure of the copy
5535 * operation, in practice it
5536 * should never fail since
5537 * we already know that the
5538 * result fits in a fixedname.
5539 */
5540 dns_fixedname_init(&fqname);
5541 result = dns_name_copy(
5542 dns_fixedname_name(&dname),
5543 dns_fixedname_name(&fqname),
5544 NULL);
5545 if (result != ISC_R_SUCCESS)
5546 return (result);
5547 wanted_chaining = ISC_TRUE;
5548 name->attributes |=
5549 DNS_NAMEATTR_CHAINING;
5550 rdataset->attributes |=
5551 DNS_RDATASETATTR_CHAINING;
5552 qname = dns_fixedname_name(
5553 &fqname);
5554 }
5555 }
5556 }
5557 if (wanted_chaining)
5558 chaining = ISC_TRUE;
5559 }
5560 result = dns_message_nextname(message, DNS_SECTION_ANSWER);
5561 }
5562 if (result == ISC_R_NOMORE)
5563 result = ISC_R_SUCCESS;
5564 if (result != ISC_R_SUCCESS)
5565 return (result);
5566
5567 /*
5568 * We should have found an answer.
5569 */
5570 if (!have_answer)
5571 return (DNS_R_FORMERR);
5572
5573 /*
5574 * This response is now potentially cacheable.
5575 */
5576 fctx->attributes |= FCTX_ATTR_WANTCACHE;
5577
5578 /*
5579 * Did chaining end before we got the final answer?
5580 */
5581 if (chaining) {
5582 /*
5583 * Yes. This may be a negative reply, so hand off
5584 * authority section processing to the noanswer code.
5585 * If it isn't a noanswer response, no harm will be
5586 * done.
5587 */
5588 return (noanswer_response(fctx, qname, ISC_FALSE));
5589 }
5590
5591 /*
5592 * We didn't end with an incomplete chain, so the rcode should be
5593 * "no error".
5594 */
5595 if (message->rcode != dns_rcode_noerror)
5596 return (DNS_R_FORMERR);
5597
5598 /*
5599 * Examine the authority section (if there is one).
5600 *
5601 * We expect there to be only one owner name for all the rdatasets
5602 * in this section, and we expect that it is not external.
5603 */
5604 done = ISC_FALSE;
5605 result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
5606 while (!done && result == ISC_R_SUCCESS) {
5607 name = NULL;
5608 dns_message_currentname(message, DNS_SECTION_AUTHORITY, &name);
5609 external = ISC_TF(!dns_name_issubdomain(name, &fctx->domain));
5610 if (!external) {
5611 /*
5612 * We expect to find NS or SIG NS rdatasets, and
5613 * nothing else.
5614 */
5615 for (rdataset = ISC_LIST_HEAD(name->list);
5616 rdataset != NULL;
5617 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5618 if (rdataset->type == dns_rdatatype_ns ||
5619 (rdataset->type == dns_rdatatype_rrsig &&
5620 rdataset->covers == dns_rdatatype_ns)) {
5621 name->attributes |=
5622 DNS_NAMEATTR_CACHE;
5623 rdataset->attributes |=
5624 DNS_RDATASETATTR_CACHE;
5625 if (aa && !chaining)
5626 rdataset->trust =
5627 dns_trust_authauthority;
5628 else
5629 rdataset->trust =
5630 dns_trust_additional;
5631
5632 /*
5633 * Mark any additional data related
5634 * to this rdataset.
5635 */
5636 (void)dns_rdataset_additionaldata(
5637 rdataset,
5638 check_related,
5639 fctx);
5640 done = ISC_TRUE;
5641 }
5642 }
5643 }
5644 result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
5645 }
5646 if (result == ISC_R_NOMORE)
5647 result = ISC_R_SUCCESS;
5648
5649 return (result);
5650 }
5651
5652 static void
5653 resume_dslookup(isc_task_t *task, isc_event_t *event) {
5654 dns_fetchevent_t *fevent;
5655 dns_resolver_t *res;
5656 fetchctx_t *fctx;
5657 isc_result_t result;
5658 isc_boolean_t bucket_empty = ISC_FALSE;
5659 isc_boolean_t locked = ISC_FALSE;
5660 unsigned int bucketnum;
5661 dns_rdataset_t nameservers;
5662 dns_fixedname_t fixed;
5663 dns_name_t *domain;
5664
5665 REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
5666 fevent = (dns_fetchevent_t *)event;
5667 fctx = event->ev_arg;
5668 REQUIRE(VALID_FCTX(fctx));
5669 res = fctx->res;
5670
5671 UNUSED(task);
5672 FCTXTRACE("resume_dslookup");
5673
5674 if (fevent->node != NULL)
5675 dns_db_detachnode(fevent->db, &fevent->node);
5676 if (fevent->db != NULL)
5677 dns_db_detach(&fevent->db);
5678
5679 dns_rdataset_init(&nameservers);
5680
5681 bucketnum = fctx->bucketnum;
5682 if (fevent->result == ISC_R_CANCELED) {
5683 dns_resolver_destroyfetch(&fctx->nsfetch);
5684 fctx_done(fctx, ISC_R_CANCELED, __LINE__);
5685 } else if (fevent->result == ISC_R_SUCCESS) {
5686
5687 FCTXTRACE("resuming DS lookup");
5688
5689 dns_resolver_destroyfetch(&fctx->nsfetch);
5690 if (dns_rdataset_isassociated(&fctx->nameservers))
5691 dns_rdataset_disassociate(&fctx->nameservers);
5692 dns_rdataset_clone(fevent->rdataset, &fctx->nameservers);
5693 dns_name_free(&fctx->domain,
5694 fctx->res->buckets[bucketnum].mctx);
5695 dns_name_init(&fctx->domain, NULL);
5696 result = dns_name_dup(&fctx->nsname,
5697 fctx->res->buckets[bucketnum].mctx,
5698 &fctx->domain);
5699 if (result != ISC_R_SUCCESS) {
5700 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
5701 goto cleanup;
5702 }
5703 /*
5704 * Try again.
5705 */
5706 fctx_try(fctx, ISC_TRUE);
5707 } else {
5708 unsigned int n;
5709 dns_rdataset_t *nsrdataset = NULL;
5710
5711 /*
5712 * Retrieve state from fctx->nsfetch before we destroy it.
5713 */
5714 dns_fixedname_init(&fixed);
5715 domain = dns_fixedname_name(&fixed);
5716 dns_name_copy(&fctx->nsfetch->private->domain, domain, NULL);
5717 if (dns_name_equal(&fctx->nsname, domain)) {
5718 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
5719 dns_resolver_destroyfetch(&fctx->nsfetch);
5720 goto cleanup;
5721 }
5722 if (dns_rdataset_isassociated(
5723 &fctx->nsfetch->private->nameservers)) {
5724 dns_rdataset_clone(
5725 &fctx->nsfetch->private->nameservers,
5726 &nameservers);
5727 nsrdataset = &nameservers;
5728 } else
5729 domain = NULL;
5730 dns_resolver_destroyfetch(&fctx->nsfetch);
5731 n = dns_name_countlabels(&fctx->nsname);
5732 dns_name_getlabelsequence(&fctx->nsname, 1, n - 1,
5733 &fctx->nsname);
5734
5735 if (dns_rdataset_isassociated(fevent->rdataset))
5736 dns_rdataset_disassociate(fevent->rdataset);
5737 FCTXTRACE("continuing to look for parent's NS records");
5738 result = dns_resolver_createfetch(fctx->res, &fctx->nsname,
5739 dns_rdatatype_ns, domain,
5740 nsrdataset, NULL, 0, task,
5741 resume_dslookup, fctx,
5742 &fctx->nsrrset, NULL,
5743 &fctx->nsfetch);
5744 if (result != ISC_R_SUCCESS)
5745 fctx_done(fctx, result, __LINE__);
5746 else {
5747 LOCK(&res->buckets[bucketnum].lock);
5748 locked = ISC_TRUE;
5749 fctx->references++;
5750 }
5751 }
5752
5753 cleanup:
5754 if (dns_rdataset_isassociated(&nameservers))
5755 dns_rdataset_disassociate(&nameservers);
5756 if (dns_rdataset_isassociated(fevent->rdataset))
5757 dns_rdataset_disassociate(fevent->rdataset);
5758 INSIST(fevent->sigrdataset == NULL);
5759 isc_event_free(&event);
5760 if (!locked)
5761 LOCK(&res->buckets[bucketnum].lock);
5762 fctx->references--;
5763 if (fctx->references == 0)
5764 bucket_empty = fctx_destroy(fctx);
5765 UNLOCK(&res->buckets[bucketnum].lock);
5766 if (bucket_empty)
5767 empty_bucket(res);
5768 }
5769
5770 static inline void
5771 checknamessection(dns_message_t *message, dns_section_t section) {
5772 isc_result_t result;
5773 dns_name_t *name;
5774 dns_rdata_t rdata = DNS_RDATA_INIT;
5775 dns_rdataset_t *rdataset;
5776
5777 for (result = dns_message_firstname(message, section);
5778 result == ISC_R_SUCCESS;
5779 result = dns_message_nextname(message, section))
5780 {
5781 name = NULL;
5782 dns_message_currentname(message, section, &name);
5783 for (rdataset = ISC_LIST_HEAD(name->list);
5784 rdataset != NULL;
5785 rdataset = ISC_LIST_NEXT(rdataset, link)) {
5786 for (result = dns_rdataset_first(rdataset);
5787 result == ISC_R_SUCCESS;
5788 result = dns_rdataset_next(rdataset)) {
5789 dns_rdataset_current(rdataset, &rdata);
5790 if (!dns_rdata_checkowner(name, rdata.rdclass,
5791 rdata.type,
5792 ISC_FALSE) ||
5793 !dns_rdata_checknames(&rdata, name, NULL))
5794 {
5795 rdataset->attributes |=
5796 DNS_RDATASETATTR_CHECKNAMES;
5797 }
5798 dns_rdata_reset(&rdata);
5799 }
5800 }
5801 }
5802 }
5803
5804 static void
5805 checknames(dns_message_t *message) {
5806
5807 checknamessection(message, DNS_SECTION_ANSWER);
5808 checknamessection(message, DNS_SECTION_AUTHORITY);
5809 checknamessection(message, DNS_SECTION_ADDITIONAL);
5810 }
5811
5812 /*
5813 * Log server NSID at log level 'level'
5814 */
5815 static isc_result_t
5816 log_nsid(dns_rdataset_t *opt, resquery_t *query, int level, isc_mem_t *mctx)
5817 {
5818 static const char hex[17] = "0123456789abcdef";
5819 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
5820 isc_uint16_t optcode, nsid_len, buflen, i;
5821 isc_result_t result;
5822 isc_buffer_t nsidbuf;
5823 dns_rdata_t rdata;
5824 unsigned char *p, *buf, *nsid;
5825
5826 /* Extract rdata from OPT rdataset */
5827 result = dns_rdataset_first(opt);
5828 if (result != ISC_R_SUCCESS)
5829 return (ISC_R_FAILURE);
5830
5831 dns_rdata_init(&rdata);
5832 dns_rdataset_current(opt, &rdata);
5833 if (rdata.length < 4)
5834 return (ISC_R_FAILURE);
5835
5836 /* Check for NSID */
5837 isc_buffer_init(&nsidbuf, rdata.data, rdata.length);
5838 isc_buffer_add(&nsidbuf, rdata.length);
5839 optcode = isc_buffer_getuint16(&nsidbuf);
5840 nsid_len = isc_buffer_getuint16(&nsidbuf);
5841 if (optcode != DNS_OPT_NSID || nsid_len == 0)
5842 return (ISC_R_FAILURE);
5843
5844 /* Allocate buffer for storing hex version of the NSID */
5845 buflen = nsid_len * 2 + 1;
5846 buf = isc_mem_get(mctx, buflen);
5847 if (buf == NULL)
5848 return (ISC_R_NOSPACE);
5849
5850 /* Convert to hex */
5851 p = buf;
5852 nsid = rdata.data + 4;
5853 for (i = 0; i < nsid_len; i++) {
5854 *p++ = hex[(nsid[0] >> 4) & 0xf];
5855 *p++ = hex[nsid[0] & 0xf];
5856 nsid++;
5857 }
5858 *p = '\0';
5859
5860 isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf,
5861 sizeof(addrbuf));
5862 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
5863 DNS_LOGMODULE_RESOLVER, level,
5864 "received NSID '%s' from %s", buf, addrbuf);
5865
5866 /* Clean up */
5867 isc_mem_put(mctx, buf, buflen);
5868 return (ISC_R_SUCCESS);
5869 }
5870
5871 static void
5872 log_packet(dns_message_t *message, int level, isc_mem_t *mctx) {
5873 isc_buffer_t buffer;
5874 char *buf = NULL;
5875 int len = 1024;
5876 isc_result_t result;
5877
5878 if (! isc_log_wouldlog(dns_lctx, level))
5879 return;
5880
5881 /*
5882 * Note that these are multiline debug messages. We want a newline
5883 * to appear in the log after each message.
5884 */
5885
5886 do {
5887 buf = isc_mem_get(mctx, len);
5888 if (buf == NULL)
5889 break;
5890 isc_buffer_init(&buffer, buf, len);
5891 result = dns_message_totext(message, &dns_master_style_debug,
5892 0, &buffer);
5893 if (result == ISC_R_NOSPACE) {
5894 isc_mem_put(mctx, buf, len);
5895 len += 1024;
5896 } else if (result == ISC_R_SUCCESS)
5897 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
5898 DNS_LOGMODULE_RESOLVER, level,
5899 "received packet:\n%.*s",
5900 (int)isc_buffer_usedlength(&buffer),
5901 buf);
5902 } while (result == ISC_R_NOSPACE);
5903
5904 if (buf != NULL)
5905 isc_mem_put(mctx, buf, len);
5906 }
5907
5908 static void
5909 resquery_response(isc_task_t *task, isc_event_t *event) {
5910 isc_result_t result = ISC_R_SUCCESS;
5911 resquery_t *query = event->ev_arg;
5912 dns_dispatchevent_t *devent = (dns_dispatchevent_t *)event;
5913 isc_boolean_t keep_trying, get_nameservers, resend;
5914 isc_boolean_t truncated;
5915 dns_message_t *message;
5916 dns_rdataset_t *opt;
5917 fetchctx_t *fctx;
5918 dns_name_t *fname;
5919 dns_fixedname_t foundname;
5920 isc_stdtime_t now;
5921 isc_time_t tnow, *finish;
5922 dns_adbaddrinfo_t *addrinfo;
5923 unsigned int options;
5924 unsigned int findoptions;
5925 isc_result_t broken_server;
5926 badnstype_t broken_type = badns_response;
5927
5928 REQUIRE(VALID_QUERY(query));
5929 fctx = query->fctx;
5930 options = query->options;
5931 REQUIRE(VALID_FCTX(fctx));
5932 REQUIRE(event->ev_type == DNS_EVENT_DISPATCH);
5933
5934 QTRACE("response");
5935
5936 if (isc_sockaddr_pf(&query->addrinfo->sockaddr) == PF_INET)
5937 inc_stats(fctx->res, dns_resstatscounter_responsev4);
5938 else
5939 inc_stats(fctx->res, dns_resstatscounter_responsev6);
5940
5941 (void)isc_timer_touch(fctx->timer);
5942
5943 keep_trying = ISC_FALSE;
5944 broken_server = ISC_R_SUCCESS;
5945 get_nameservers = ISC_FALSE;
5946 resend = ISC_FALSE;
5947 truncated = ISC_FALSE;
5948 finish = NULL;
5949
5950 if (fctx->res->exiting) {
5951 result = ISC_R_SHUTTINGDOWN;
5952 goto done;
5953 }
5954
5955 fctx->timeouts = 0;
5956 fctx->timeout = ISC_FALSE;
5957
5958 /*
5959 * XXXRTH We should really get the current time just once. We
5960 * need a routine to convert from an isc_time_t to an
5961 * isc_stdtime_t.
5962 */
5963 TIME_NOW(&tnow);
5964 finish = &tnow;
5965 isc_stdtime_get(&now);
5966
5967 /*
5968 * Did the dispatcher have a problem?
5969 */
5970 if (devent->result != ISC_R_SUCCESS) {
5971 if (devent->result == ISC_R_EOF &&
5972 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
5973 /*
5974 * The problem might be that they
5975 * don't understand EDNS0. Turn it
5976 * off and try again.
5977 */
5978 options |= DNS_FETCHOPT_NOEDNS0;
5979 resend = ISC_TRUE;
5980 /*
5981 * Remember that they don't like EDNS0.
5982 */
5983 dns_adb_changeflags(fctx->adb,
5984 query->addrinfo,
5985 DNS_FETCHOPT_NOEDNS0,
5986 DNS_FETCHOPT_NOEDNS0);
5987 } else {
5988 /*
5989 * There's no hope for this query.
5990 */
5991 keep_trying = ISC_TRUE;
5992
5993 /*
5994 * If this is a network error on an exclusive query
5995 * socket, mark the server as bad so that we won't try
5996 * it for this fetch again.
5997 */
5998 if (query->exclusivesocket &&
5999 (devent->result == ISC_R_HOSTUNREACH ||
6000 devent->result == ISC_R_NETUNREACH ||
6001 devent->result == ISC_R_CONNREFUSED ||
6002 devent->result == ISC_R_CANCELED)) {
6003 broken_server = devent->result;
6004 broken_type = badns_unreachable;
6005 }
6006 }
6007 goto done;
6008 }
6009
6010 message = fctx->rmessage;
6011
6012 if (query->tsig != NULL) {
6013 result = dns_message_setquerytsig(message, query->tsig);
6014 if (result != ISC_R_SUCCESS)
6015 goto done;
6016 }
6017
6018 if (query->tsigkey) {
6019 result = dns_message_settsigkey(message, query->tsigkey);
6020 if (result != ISC_R_SUCCESS)
6021 goto done;
6022 }
6023
6024 result = dns_message_parse(message, &devent->buffer, 0);
6025 if (result != ISC_R_SUCCESS) {
6026 switch (result) {
6027 case ISC_R_UNEXPECTEDEND:
6028 if (!message->question_ok ||
6029 (message->flags & DNS_MESSAGEFLAG_TC) == 0 ||
6030 (options & DNS_FETCHOPT_TCP) != 0) {
6031 /*
6032 * Either the message ended prematurely,
6033 * and/or wasn't marked as being truncated,
6034 * and/or this is a response to a query we
6035 * sent over TCP. In all of these cases,
6036 * something is wrong with the remote
6037 * server and we don't want to retry using
6038 * TCP.
6039 */
6040 if ((query->options & DNS_FETCHOPT_NOEDNS0)
6041 == 0) {
6042 /*
6043 * The problem might be that they
6044 * don't understand EDNS0. Turn it
6045 * off and try again.
6046 */
6047 options |= DNS_FETCHOPT_NOEDNS0;
6048 resend = ISC_TRUE;
6049 /*
6050 * Remember that they don't like EDNS0.
6051 */
6052 dns_adb_changeflags(
6053 fctx->adb,
6054 query->addrinfo,
6055 DNS_FETCHOPT_NOEDNS0,
6056 DNS_FETCHOPT_NOEDNS0);
6057 inc_stats(fctx->res,
6058 dns_resstatscounter_edns0fail);
6059 } else {
6060 broken_server = result;
6061 keep_trying = ISC_TRUE;
6062 }
6063 goto done;
6064 }
6065 /*
6066 * We defer retrying via TCP for a bit so we can
6067 * check out this message further.
6068 */
6069 truncated = ISC_TRUE;
6070 break;
6071 case DNS_R_FORMERR:
6072 if ((query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
6073 /*
6074 * The problem might be that they
6075 * don't understand EDNS0. Turn it
6076 * off and try again.
6077 */
6078 options |= DNS_FETCHOPT_NOEDNS0;
6079 resend = ISC_TRUE;
6080 /*
6081 * Remember that they don't like EDNS0.
6082 */
6083 dns_adb_changeflags(fctx->adb,
6084 query->addrinfo,
6085 DNS_FETCHOPT_NOEDNS0,
6086 DNS_FETCHOPT_NOEDNS0);
6087 inc_stats(fctx->res,
6088 dns_resstatscounter_edns0fail);
6089 } else {
6090 broken_server = DNS_R_UNEXPECTEDRCODE;
6091 keep_trying = ISC_TRUE;
6092 }
6093 goto done;
6094 default:
6095 /*
6096 * Something bad has happened.
6097 */
6098 goto done;
6099 }
6100 }
6101
6102
6103 /*
6104 * Log the incoming packet.
6105 */
6106 log_packet(message, ISC_LOG_DEBUG(10), fctx->res->mctx);
6107
6108 /*
6109 * Did we request NSID? If so, and if the response contains
6110 * NSID data, log it at INFO level.
6111 */
6112 opt = dns_message_getopt(message);
6113 if (opt != NULL && (query->options & DNS_FETCHOPT_WANTNSID) != 0)
6114 log_nsid(opt, query, ISC_LOG_INFO, fctx->res->mctx);
6115
6116 /*
6117 * If the message is signed, check the signature. If not, this
6118 * returns success anyway.
6119 */
6120 result = dns_message_checksig(message, fctx->res->view);
6121 if (result != ISC_R_SUCCESS)
6122 goto done;
6123
6124 /*
6125 * The dispatcher should ensure we only get responses with QR set.
6126 */
6127 INSIST((message->flags & DNS_MESSAGEFLAG_QR) != 0);
6128 /*
6129 * INSIST() that the message comes from the place we sent it to,
6130 * since the dispatch code should ensure this.
6131 *
6132 * INSIST() that the message id is correct (this should also be
6133 * ensured by the dispatch code).
6134 */
6135
6136
6137 /*
6138 * Deal with truncated responses by retrying using TCP.
6139 */
6140 if ((message->flags & DNS_MESSAGEFLAG_TC) != 0)
6141 truncated = ISC_TRUE;
6142
6143 if (truncated) {
6144 inc_stats(fctx->res, dns_resstatscounter_truncated);
6145 if ((options & DNS_FETCHOPT_TCP) != 0) {
6146 broken_server = DNS_R_TRUNCATEDTCP;
6147 keep_trying = ISC_TRUE;
6148 } else {
6149 options |= DNS_FETCHOPT_TCP;
6150 resend = ISC_TRUE;
6151 }
6152 goto done;
6153 }
6154
6155 /*
6156 * Is it a query response?
6157 */
6158 if (message->opcode != dns_opcode_query) {
6159 /* XXXRTH Log */
6160 broken_server = DNS_R_UNEXPECTEDOPCODE;
6161 keep_trying = ISC_TRUE;
6162 goto done;
6163 }
6164
6165 /*
6166 * Update statistics about erroneous responses.
6167 */
6168 if (message->rcode != dns_rcode_noerror) {
6169 switch (message->rcode) {
6170 case dns_rcode_nxdomain:
6171 inc_stats(fctx->res, dns_resstatscounter_nxdomain);
6172 break;
6173 case dns_rcode_servfail:
6174 inc_stats(fctx->res, dns_resstatscounter_servfail);
6175 break;
6176 case dns_rcode_formerr:
6177 inc_stats(fctx->res, dns_resstatscounter_formerr);
6178 break;
6179 default:
6180 inc_stats(fctx->res, dns_resstatscounter_othererror);
6181 break;
6182 }
6183 }
6184
6185 /*
6186 * Is the remote server broken, or does it dislike us?
6187 */
6188 if (message->rcode != dns_rcode_noerror &&
6189 message->rcode != dns_rcode_nxdomain) {
6190 if (((message->rcode == dns_rcode_formerr ||
6191 message->rcode == dns_rcode_notimp) ||
6192 (message->rcode == dns_rcode_servfail &&
6193 dns_message_getopt(message) == NULL)) &&
6194 (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
6195 /*
6196 * It's very likely they don't like EDNS0.
6197 * If the response code is SERVFAIL, also check if the
6198 * response contains an OPT RR and don't cache the
6199 * failure since it can be returned for various other
6200 * reasons.
6201 *
6202 * XXXRTH We should check if the question
6203 * we're asking requires EDNS0, and
6204 * if so, we should bail out.
6205 */
6206 options |= DNS_FETCHOPT_NOEDNS0;
6207 resend = ISC_TRUE;
6208 /*
6209 * Remember that they don't like EDNS0.
6210 */
6211 if (message->rcode != dns_rcode_servfail)
6212 dns_adb_changeflags(fctx->adb, query->addrinfo,
6213 DNS_FETCHOPT_NOEDNS0,
6214 DNS_FETCHOPT_NOEDNS0);
6215 inc_stats(fctx->res, dns_resstatscounter_edns0fail);
6216 } else if (message->rcode == dns_rcode_formerr) {
6217 if (ISFORWARDER(query->addrinfo)) {
6218 /*
6219 * This forwarder doesn't understand us,
6220 * but other forwarders might. Keep trying.
6221 */
6222 broken_server = DNS_R_REMOTEFORMERR;
6223 keep_trying = ISC_TRUE;
6224 } else {
6225 /*
6226 * The server doesn't understand us. Since
6227 * all servers for a zone need similar
6228 * capabilities, we assume that we will get
6229 * FORMERR from all servers, and thus we
6230 * cannot make any more progress with this
6231 * fetch.
6232 */
6233 result = DNS_R_FORMERR;
6234 }
6235 } else if (message->rcode == dns_rcode_yxdomain) {
6236 /*
6237 * DNAME mapping failed because the new name
6238 * was too long. There's no chance of success
6239 * for this fetch.
6240 */
6241 result = DNS_R_YXDOMAIN;
6242 } else if (message->rcode == dns_rcode_badvers) {
6243 unsigned int flags, mask;
6244 unsigned int version;
6245
6246 resend = ISC_TRUE;
6247 version = (opt->ttl >> 16) & 0xff;
6248 flags = (version << DNS_FETCHOPT_EDNSVERSIONSHIFT) |
6249 DNS_FETCHOPT_EDNSVERSIONSET;
6250 mask = DNS_FETCHOPT_EDNSVERSIONMASK |
6251 DNS_FETCHOPT_EDNSVERSIONSET;
6252 switch (version) {
6253 case 0:
6254 dns_adb_changeflags(fctx->adb, query->addrinfo,
6255 flags, mask);
6256 break;
6257 default:
6258 broken_server = DNS_R_BADVERS;
6259 keep_trying = ISC_TRUE;
6260 break;
6261 }
6262 } else {
6263 /*
6264 * XXXRTH log.
6265 */
6266 broken_server = DNS_R_UNEXPECTEDRCODE;
6267 INSIST(broken_server != ISC_R_SUCCESS);
6268 keep_trying = ISC_TRUE;
6269 }
6270 goto done;
6271 }
6272
6273 /*
6274 * Is the question the same as the one we asked?
6275 */
6276 result = same_question(fctx);
6277 if (result != ISC_R_SUCCESS) {
6278 /* XXXRTH Log */
6279 if (result == DNS_R_FORMERR)
6280 keep_trying = ISC_TRUE;
6281 goto done;
6282 }
6283
6284 /*
6285 * Is the server lame?
6286 */
6287 if (fctx->res->lame_ttl != 0 && !ISFORWARDER(query->addrinfo) &&
6288 is_lame(fctx)) {
6289 inc_stats(fctx->res, dns_resstatscounter_lame);
6290 log_lame(fctx, query->addrinfo);
6291 result = dns_adb_marklame(fctx->adb, query->addrinfo,
6292 &fctx->name, fctx->type,
6293 now + fctx->res->lame_ttl);
6294 if (result != ISC_R_SUCCESS)
6295 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
6296 DNS_LOGMODULE_RESOLVER, ISC_LOG_ERROR,
6297 "could not mark server as lame: %s",
6298 isc_result_totext(result));
6299 broken_server = DNS_R_LAME;
6300 keep_trying = ISC_TRUE;
6301 goto done;
6302 }
6303
6304 /*
6305 * Enforce delegations only zones like NET and COM.
6306 */
6307 if (!ISFORWARDER(query->addrinfo) &&
6308 dns_view_isdelegationonly(fctx->res->view, &fctx->domain) &&
6309 !dns_name_equal(&fctx->domain, &fctx->name) &&
6310 fix_mustbedelegationornxdomain(message, fctx)) {
6311 char namebuf[DNS_NAME_FORMATSIZE];
6312 char domainbuf[DNS_NAME_FORMATSIZE];
6313 char addrbuf[ISC_SOCKADDR_FORMATSIZE];
6314 char classbuf[64];
6315 char typebuf[64];
6316
6317 dns_name_format(&fctx->name, namebuf, sizeof(namebuf));
6318 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
6319 dns_rdatatype_format(fctx->type, typebuf, sizeof(typebuf));
6320 dns_rdataclass_format(fctx->res->rdclass, classbuf,
6321 sizeof(classbuf));
6322 isc_sockaddr_format(&query->addrinfo->sockaddr, addrbuf,
6323 sizeof(addrbuf));
6324
6325 isc_log_write(dns_lctx, DNS_LOGCATEGORY_DELEGATION_ONLY,
6326 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
6327 "enforced delegation-only for '%s' (%s/%s/%s) "
6328 "from %s",
6329 domainbuf, namebuf, typebuf, classbuf, addrbuf);
6330 }
6331
6332 if ((fctx->res->options & DNS_RESOLVER_CHECKNAMES) != 0)
6333 checknames(message);
6334
6335 /*
6336 * Clear cache bits.
6337 */
6338 fctx->attributes &= ~(FCTX_ATTR_WANTNCACHE | FCTX_ATTR_WANTCACHE);
6339
6340 /*
6341 * Did we get any answers?
6342 */
6343 if (message->counts[DNS_SECTION_ANSWER] > 0 &&
6344 (message->rcode == dns_rcode_noerror ||
6345 message->rcode == dns_rcode_nxdomain)) {
6346 /*
6347 * We've got answers. However, if we sent
6348 * a BIND 8 server an NS query, it may have
6349 * incorrectly responded with a non-authoritative
6350 * answer instead of a referral. Since this
6351 * answer lacks the SIGs necessary to do DNSSEC
6352 * validation, we must invoke the following special
6353 * kludge to treat it as a referral.
6354 */
6355 if (fctx->type == dns_rdatatype_ns &&
6356 (message->flags & DNS_MESSAGEFLAG_AA) == 0 &&
6357 !ISFORWARDER(query->addrinfo))
6358 {
6359 result = noanswer_response(fctx, NULL, ISC_TRUE);
6360 if (result != DNS_R_DELEGATION) {
6361 /*
6362 * The answer section must have contained
6363 * something other than the NS records
6364 * we asked for. Since AA is not set
6365 * and the server is not a forwarder,
6366 * it is technically lame and it's easier
6367 * to treat it as such than to figure out
6368 * some more elaborate course of action.
6369 */
6370 broken_server = DNS_R_LAME;
6371 keep_trying = ISC_TRUE;
6372 goto done;
6373 }
6374 goto force_referral;
6375 }
6376 result = answer_response(fctx);
6377 if (result != ISC_R_SUCCESS) {
6378 if (result == DNS_R_FORMERR)
6379 keep_trying = ISC_TRUE;
6380 goto done;
6381 }
6382 } else if (message->counts[DNS_SECTION_AUTHORITY] > 0 ||
6383 message->rcode == dns_rcode_noerror ||
6384 message->rcode == dns_rcode_nxdomain) {
6385 /*
6386 * NXDOMAIN, NXRDATASET, or referral.
6387 */
6388 result = noanswer_response(fctx, NULL, ISC_FALSE);
6389 if (result == DNS_R_CHASEDSSERVERS) {
6390 } else if (result == DNS_R_DELEGATION) {
6391 force_referral:
6392 /*
6393 * We don't have the answer, but we know a better
6394 * place to look.
6395 */
6396 get_nameservers = ISC_TRUE;
6397 keep_trying = ISC_TRUE;
6398 /*
6399 * We have a new set of name servers, and it
6400 * has not experienced any restarts yet.
6401 */
6402 fctx->restarts = 0;
6403
6404 /*
6405 * Update local statistics counters collected for each
6406 * new zone.
6407 */
6408 fctx->referrals++;
6409 fctx->querysent = 0;
6410 fctx->lamecount = 0;
6411 fctx->neterr = 0;
6412 fctx->badresp = 0;
6413 fctx->adberr = 0;
6414
6415 result = ISC_R_SUCCESS;
6416 } else if (result != ISC_R_SUCCESS) {
6417 /*
6418 * Something has gone wrong.
6419 */
6420 if (result == DNS_R_FORMERR)
6421 keep_trying = ISC_TRUE;
6422 goto done;
6423 }
6424 } else {
6425 /*
6426 * The server is insane.
6427 */
6428 /* XXXRTH Log */
6429 broken_server = DNS_R_UNEXPECTEDRCODE;
6430 keep_trying = ISC_TRUE;
6431 goto done;
6432 }
6433
6434 /*
6435 * Follow additional section data chains.
6436 */
6437 chase_additional(fctx);
6438
6439 /*
6440 * Cache the cacheable parts of the message. This may also cause
6441 * work to be queued to the DNSSEC validator.
6442 */
6443 if (WANTCACHE(fctx)) {
6444 result = cache_message(fctx, query->addrinfo, now);
6445 if (result != ISC_R_SUCCESS)
6446 goto done;
6447 }
6448
6449 /*
6450 * Ncache the negatively cacheable parts of the message. This may
6451 * also cause work to be queued to the DNSSEC validator.
6452 */
6453 if (WANTNCACHE(fctx)) {
6454 dns_rdatatype_t covers;
6455 if (message->rcode == dns_rcode_nxdomain)
6456 covers = dns_rdatatype_any;
6457 else
6458 covers = fctx->type;
6459
6460 /*
6461 * Cache any negative cache entries in the message.
6462 */
6463 result = ncache_message(fctx, query->addrinfo, covers, now);
6464 }
6465
6466 done:
6467 /*
6468 * Remember the query's addrinfo, in case we need to mark the
6469 * server as broken.
6470 */
6471 addrinfo = query->addrinfo;
6472
6473 /*
6474 * Cancel the query.
6475 *
6476 * XXXRTH Don't cancel the query if waiting for validation?
6477 */
6478 fctx_cancelquery(&query, &devent, finish, ISC_FALSE);
6479
6480 if (keep_trying) {
6481 if (result == DNS_R_FORMERR)
6482 broken_server = DNS_R_FORMERR;
6483 if (broken_server != ISC_R_SUCCESS) {
6484 /*
6485 * Add this server to the list of bad servers for
6486 * this fctx.
6487 */
6488 add_bad(fctx, addrinfo, broken_server, broken_type);
6489 }
6490
6491 if (get_nameservers) {
6492 dns_name_t *name;
6493 dns_fixedname_init(&foundname);
6494 fname = dns_fixedname_name(&foundname);
6495 if (result != ISC_R_SUCCESS) {
6496 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6497 return;
6498 }
6499 findoptions = 0;
6500 if (dns_rdatatype_atparent(fctx->type))
6501 findoptions |= DNS_DBFIND_NOEXACT;
6502 if ((options & DNS_FETCHOPT_UNSHARED) == 0)
6503 name = &fctx->name;
6504 else
6505 name = &fctx->domain;
6506 result = dns_view_findzonecut(fctx->res->view,
6507 name, fname,
6508 now, findoptions,
6509 ISC_TRUE,
6510 &fctx->nameservers,
6511 NULL);
6512 if (result != ISC_R_SUCCESS) {
6513 FCTXTRACE("couldn't find a zonecut");
6514 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6515 return;
6516 }
6517 if (!dns_name_issubdomain(fname, &fctx->domain)) {
6518 /*
6519 * The best nameservers are now above our
6520 * QDOMAIN.
6521 */
6522 FCTXTRACE("nameservers now above QDOMAIN");
6523 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6524 return;
6525 }
6526 dns_name_free(&fctx->domain,
6527 fctx->res->buckets[fctx->bucketnum].mctx);
6528 dns_name_init(&fctx->domain, NULL);
6529 result = dns_name_dup(fname,
6530 fctx->res->buckets[fctx->bucketnum].mctx,
6531 &fctx->domain);
6532 if (result != ISC_R_SUCCESS) {
6533 fctx_done(fctx, DNS_R_SERVFAIL, __LINE__);
6534 return;
6535 }
6536 fctx_cancelqueries(fctx, ISC_TRUE);
6537 fctx_cleanupfinds(fctx);
6538 fctx_cleanupaltfinds(fctx);
6539 fctx_cleanupforwaddrs(fctx);
6540 fctx_cleanupaltaddrs(fctx);
6541 }
6542 /*
6543 * Try again.
6544 */
6545 fctx_try(fctx, !get_nameservers);
6546 } else if (resend) {
6547 /*
6548 * Resend (probably with changed options).
6549 */
6550 FCTXTRACE("resend");
6551 inc_stats(fctx->res, dns_resstatscounter_retry);
6552 result = fctx_query(fctx, addrinfo, options);
6553 if (result != ISC_R_SUCCESS)
6554 fctx_done(fctx, result, __LINE__);
6555 } else if (result == ISC_R_SUCCESS && !HAVE_ANSWER(fctx)) {
6556 /*
6557 * All has gone well so far, but we are waiting for the
6558 * DNSSEC validator to validate the answer.
6559 */
6560 FCTXTRACE("wait for validator");
6561 fctx_cancelqueries(fctx, ISC_TRUE);
6562 /*
6563 * We must not retransmit while the validator is working;
6564 * it has references to the current rmessage.
6565 */
6566 result = fctx_stopidletimer(fctx);
6567 if (result != ISC_R_SUCCESS)
6568 fctx_done(fctx, result, __LINE__);
6569 } else if (result == DNS_R_CHASEDSSERVERS) {
6570 unsigned int n;
6571 add_bad(fctx, addrinfo, result, broken_type);
6572 fctx_cancelqueries(fctx, ISC_TRUE);
6573 fctx_cleanupfinds(fctx);
6574 fctx_cleanupforwaddrs(fctx);
6575
6576 n = dns_name_countlabels(&fctx->name);
6577 dns_name_getlabelsequence(&fctx->name, 1, n - 1, &fctx->nsname);
6578
6579 FCTXTRACE("suspending DS lookup to find parent's NS records");
6580
6581 result = dns_resolver_createfetch(fctx->res, &fctx->nsname,
6582 dns_rdatatype_ns,
6583 NULL, NULL, NULL, 0, task,
6584 resume_dslookup, fctx,
6585 &fctx->nsrrset, NULL,
6586 &fctx->nsfetch);
6587 if (result != ISC_R_SUCCESS)
6588 fctx_done(fctx, result, __LINE__);
6589 LOCK(&fctx->res->buckets[fctx->bucketnum].lock);
6590 fctx->references++;
6591 UNLOCK(&fctx->res->buckets[fctx->bucketnum].lock);
6592 result = fctx_stopidletimer(fctx);
6593 if (result != ISC_R_SUCCESS)
6594 fctx_done(fctx, result, __LINE__);
6595 } else {
6596 /*
6597 * We're done.
6598 */
6599 fctx_done(fctx, result, __LINE__);
6600 }
6601 }
6602
6603
6604 /***
6605 *** Resolver Methods
6606 ***/
6607
6608 static void
6609 destroy(dns_resolver_t *res) {
6610 unsigned int i;
6611 alternate_t *a;
6612
6613 REQUIRE(res->references == 0);
6614 REQUIRE(!res->priming);
6615 REQUIRE(res->primefetch == NULL);
6616
6617 RTRACE("destroy");
6618
6619 INSIST(res->nfctx == 0);
6620
6621 DESTROYLOCK(&res->primelock);
6622 DESTROYLOCK(&res->nlock);
6623 DESTROYLOCK(&res->lock);
6624 for (i = 0; i < res->nbuckets; i++) {
6625 INSIST(ISC_LIST_EMPTY(res->buckets[i].fctxs));
6626 isc_task_shutdown(res->buckets[i].task);
6627 isc_task_detach(&res->buckets[i].task);
6628 DESTROYLOCK(&res->buckets[i].lock);
6629 isc_mem_detach(&res->buckets[i].mctx);
6630 }
6631 isc_mem_put(res->mctx, res->buckets,
6632 res->nbuckets * sizeof(fctxbucket_t));
6633 if (res->dispatchv4 != NULL)
6634 dns_dispatch_detach(&res->dispatchv4);
6635 if (res->dispatchv6 != NULL)
6636 dns_dispatch_detach(&res->dispatchv6);
6637 while ((a = ISC_LIST_HEAD(res->alternates)) != NULL) {
6638 ISC_LIST_UNLINK(res->alternates, a, link);
6639 if (!a->isaddress)
6640 dns_name_free(&a->_u._n.name, res->mctx);
6641 isc_mem_put(res->mctx, a, sizeof(*a));
6642 }
6643 dns_resolver_reset_algorithms(res);
6644 dns_resolver_resetmustbesecure(res);
6645 #if USE_ALGLOCK
6646 isc_rwlock_destroy(&res->alglock);
6647 #endif
6648 #if USE_MBSLOCK
6649 isc_rwlock_destroy(&res->mbslock);
6650 #endif
6651 isc_timer_detach(&res->spillattimer);
6652 res->magic = 0;
6653 isc_mem_put(res->mctx, res, sizeof(*res));
6654 }
6655
6656 static void
6657 send_shutdown_events(dns_resolver_t *res) {
6658 isc_event_t *event, *next_event;
6659 isc_task_t *etask;
6660
6661 /*
6662 * Caller must be holding the resolver lock.
6663 */
6664
6665 for (event = ISC_LIST_HEAD(res->whenshutdown);
6666 event != NULL;
6667 event = next_event) {
6668 next_event = ISC_LIST_NEXT(event, ev_link);
6669 ISC_LIST_UNLINK(res->whenshutdown, event, ev_link);
6670 etask = event->ev_sender;
6671 event->ev_sender = res;
6672 isc_task_sendanddetach(&etask, &event);
6673 }
6674 }
6675
6676 static void
6677 empty_bucket(dns_resolver_t *res) {
6678 RTRACE("empty_bucket");
6679
6680 LOCK(&res->lock);
6681
6682 INSIST(res->activebuckets > 0);
6683 res->activebuckets--;
6684 if (res->activebuckets == 0)
6685 send_shutdown_events(res);
6686
6687 UNLOCK(&res->lock);
6688 }
6689
6690 static void
6691 spillattimer_countdown(isc_task_t *task, isc_event_t *event) {
6692 dns_resolver_t *res = event->ev_arg;
6693 isc_result_t result;
6694 unsigned int count;
6695 isc_boolean_t logit = ISC_FALSE;
6696
6697 REQUIRE(VALID_RESOLVER(res));
6698
6699 UNUSED(task);
6700
6701 LOCK(&res->lock);
6702 INSIST(!res->exiting);
6703 if (res->spillat > res->spillatmin) {
6704 res->spillat--;
6705 logit = ISC_TRUE;
6706 }
6707 if (res->spillat <= res->spillatmin) {
6708 result = isc_timer_reset(res->spillattimer,
6709 isc_timertype_inactive, NULL,
6710 NULL, ISC_TRUE);
6711 RUNTIME_CHECK(result == ISC_R_SUCCESS);
6712 }
6713 count = res->spillat;
6714 UNLOCK(&res->lock);
6715 if (logit)
6716 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
6717 DNS_LOGMODULE_RESOLVER, ISC_LOG_NOTICE,
6718 "clients-per-query decreased to %u", count);
6719
6720 isc_event_free(&event);
6721 }
6722
6723 isc_result_t
6724 dns_resolver_create(dns_view_t *view,
6725 isc_taskmgr_t *taskmgr, unsigned int ntasks,
6726 isc_socketmgr_t *socketmgr,
6727 isc_timermgr_t *timermgr,
6728 unsigned int options,
6729 dns_dispatchmgr_t *dispatchmgr,
6730 dns_dispatch_t *dispatchv4,
6731 dns_dispatch_t *dispatchv6,
6732 dns_resolver_t **resp)
6733 {
6734 dns_resolver_t *res;
6735 isc_result_t result = ISC_R_SUCCESS;
6736 unsigned int i, buckets_created = 0;
6737 isc_task_t *task = NULL;
6738 char name[16];
6739 unsigned dispattr;
6740
6741 /*
6742 * Create a resolver.
6743 */
6744
6745 REQUIRE(DNS_VIEW_VALID(view));
6746 REQUIRE(ntasks > 0);
6747 REQUIRE(resp != NULL && *resp == NULL);
6748 REQUIRE(dispatchmgr != NULL);
6749 REQUIRE(dispatchv4 != NULL || dispatchv6 != NULL);
6750
6751 res = isc_mem_get(view->mctx, sizeof(*res));
6752 if (res == NULL)
6753 return (ISC_R_NOMEMORY);
6754 RTRACE("create");
6755 res->mctx = view->mctx;
6756 res->rdclass = view->rdclass;
6757 res->socketmgr = socketmgr;
6758 res->timermgr = timermgr;
6759 res->taskmgr = taskmgr;
6760 res->dispatchmgr = dispatchmgr;
6761 res->view = view;
6762 res->options = options;
6763 res->lame_ttl = 0;
6764 ISC_LIST_INIT(res->alternates);
6765 res->udpsize = RECV_BUFFER_SIZE;
6766 res->algorithms = NULL;
6767 res->mustbesecure = NULL;
6768 res->spillatmin = res->spillat = 10;
6769 res->spillatmax = 100;
6770 res->spillattimer = NULL;
6771 res->zero_no_soa_ttl = ISC_FALSE;
6772 res->ndisps = 0;
6773 res->nextdisp = 0; /* meaningless at this point, but init it */
6774 res->nbuckets = ntasks;
6775 res->activebuckets = ntasks;
6776 res->buckets = isc_mem_get(view->mctx,
6777 ntasks * sizeof(fctxbucket_t));
6778 if (res->buckets == NULL) {
6779 result = ISC_R_NOMEMORY;
6780 goto cleanup_res;
6781 }
6782 for (i = 0; i < ntasks; i++) {
6783 result = isc_mutex_init(&res->buckets[i].lock);
6784 if (result != ISC_R_SUCCESS)
6785 goto cleanup_buckets;
6786 res->buckets[i].task = NULL;
6787 result = isc_task_create(taskmgr, 0, &res->buckets[i].task);
6788 if (result != ISC_R_SUCCESS) {
6789 DESTROYLOCK(&res->buckets[i].lock);
6790 goto cleanup_buckets;
6791 }
6792 res->buckets[i].mctx = NULL;
6793 snprintf(name, sizeof(name), "res%u", i);
6794 #ifdef ISC_PLATFORM_USETHREADS
6795 /*
6796 * Use a separate memory context for each bucket to reduce
6797 * contention among multiple threads. Do this only when
6798 * enabling threads because it will be require more memory.
6799 */
6800 result = isc_mem_create(0, 0, &res->buckets[i].mctx);
6801 if (result != ISC_R_SUCCESS) {
6802 isc_task_detach(&res->buckets[i].task);
6803 DESTROYLOCK(&res->buckets[i].lock);
6804 goto cleanup_buckets;
6805 }
6806 isc_mem_setname(res->buckets[i].mctx, name, NULL);
6807 #else
6808 isc_mem_attach(view->mctx, &res->buckets[i].mctx);
6809 #endif
6810 isc_task_setname(res->buckets[i].task, name, res);
6811 ISC_LIST_INIT(res->buckets[i].fctxs);
6812 res->buckets[i].exiting = ISC_FALSE;
6813 buckets_created++;
6814 }
6815
6816 res->dispatchv4 = NULL;
6817 if (dispatchv4 != NULL) {
6818 dns_dispatch_attach(dispatchv4, &res->dispatchv4);
6819 dispattr = dns_dispatch_getattributes(dispatchv4);
6820 res->exclusivev4 =
6821 ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
6822 }
6823
6824 res->dispatchv6 = NULL;
6825 if (dispatchv6 != NULL) {
6826 dns_dispatch_attach(dispatchv6, &res->dispatchv6);
6827 dispattr = dns_dispatch_getattributes(dispatchv6);
6828 res->exclusivev6 =
6829 ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
6830 }
6831
6832 res->references = 1;
6833 res->exiting = ISC_FALSE;
6834 res->frozen = ISC_FALSE;
6835 ISC_LIST_INIT(res->whenshutdown);
6836 res->priming = ISC_FALSE;
6837 res->primefetch = NULL;
6838 res->nfctx = 0;
6839
6840 result = isc_mutex_init(&res->lock);
6841 if (result != ISC_R_SUCCESS)
6842 goto cleanup_dispatches;
6843
6844 result = isc_mutex_init(&res->nlock);
6845 if (result != ISC_R_SUCCESS)
6846 goto cleanup_lock;
6847
6848 result = isc_mutex_init(&res->primelock);
6849 if (result != ISC_R_SUCCESS)
6850 goto cleanup_nlock;
6851
6852 task = NULL;
6853 result = isc_task_create(taskmgr, 0, &task);
6854 if (result != ISC_R_SUCCESS)
6855 goto cleanup_primelock;
6856
6857 result = isc_timer_create(timermgr, isc_timertype_inactive, NULL, NULL,
6858 task, spillattimer_countdown, res,
6859 &res->spillattimer);
6860 isc_task_detach(&task);
6861 if (result != ISC_R_SUCCESS)
6862 goto cleanup_primelock;
6863
6864 #if USE_ALGLOCK
6865 result = isc_rwlock_init(&res->alglock, 0, 0);
6866 if (result != ISC_R_SUCCESS)
6867 goto cleanup_spillattimer;
6868 #endif
6869 #if USE_MBSLOCK
6870 result = isc_rwlock_init(&res->mbslock, 0, 0);
6871 if (result != ISC_R_SUCCESS)
6872 goto cleanup_alglock;
6873 #endif
6874
6875 res->magic = RES_MAGIC;
6876
6877 *resp = res;
6878
6879 return (ISC_R_SUCCESS);
6880
6881 #if USE_MBSLOCK
6882 cleanup_alglock:
6883 #if USE_ALGLOCK
6884 isc_rwlock_destroy(&res->alglock);
6885 #endif
6886 #endif
6887 #if USE_ALGLOCK || USE_MBSLOCK
6888 cleanup_spillattimer:
6889 isc_timer_detach(&res->spillattimer);
6890 #endif
6891
6892 cleanup_primelock:
6893 DESTROYLOCK(&res->primelock);
6894
6895 cleanup_nlock:
6896 DESTROYLOCK(&res->nlock);
6897
6898 cleanup_lock:
6899 DESTROYLOCK(&res->lock);
6900
6901 cleanup_dispatches:
6902 if (res->dispatchv6 != NULL)
6903 dns_dispatch_detach(&res->dispatchv6);
6904 if (res->dispatchv4 != NULL)
6905 dns_dispatch_detach(&res->dispatchv4);
6906
6907 cleanup_buckets:
6908 for (i = 0; i < buckets_created; i++) {
6909 isc_mem_detach(&res->buckets[i].mctx);
6910 DESTROYLOCK(&res->buckets[i].lock);
6911 isc_task_shutdown(res->buckets[i].task);
6912 isc_task_detach(&res->buckets[i].task);
6913 }
6914 isc_mem_put(view->mctx, res->buckets,
6915 res->nbuckets * sizeof(fctxbucket_t));
6916
6917 cleanup_res:
6918 isc_mem_put(view->mctx, res, sizeof(*res));
6919
6920 return (result);
6921 }
6922
6923 static void
6924 prime_done(isc_task_t *task, isc_event_t *event) {
6925 dns_resolver_t *res;
6926 dns_fetchevent_t *fevent;
6927 dns_fetch_t *fetch;
6928 dns_db_t *db = NULL;
6929
6930 REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
6931 fevent = (dns_fetchevent_t *)event;
6932 res = event->ev_arg;
6933 REQUIRE(VALID_RESOLVER(res));
6934
6935 UNUSED(task);
6936
6937 LOCK(&res->lock);
6938
6939 INSIST(res->priming);
6940 res->priming = ISC_FALSE;
6941 LOCK(&res->primelock);
6942 fetch = res->primefetch;
6943 res->primefetch = NULL;
6944 UNLOCK(&res->primelock);
6945
6946 UNLOCK(&res->lock);
6947
6948 if (fevent->result == ISC_R_SUCCESS &&
6949 res->view->cache != NULL && res->view->hints != NULL) {
6950 dns_cache_attachdb(res->view->cache, &db);
6951 dns_root_checkhints(res->view, res->view->hints, db);
6952 dns_db_detach(&db);
6953 }
6954
6955 if (fevent->node != NULL)
6956 dns_db_detachnode(fevent->db, &fevent->node);
6957 if (fevent->db != NULL)
6958 dns_db_detach(&fevent->db);
6959 if (dns_rdataset_isassociated(fevent->rdataset))
6960 dns_rdataset_disassociate(fevent->rdataset);
6961 INSIST(fevent->sigrdataset == NULL);
6962
6963 isc_mem_put(res->mctx, fevent->rdataset, sizeof(*fevent->rdataset));
6964
6965 isc_event_free(&event);
6966 dns_resolver_destroyfetch(&fetch);
6967 }
6968
6969 void
6970 dns_resolver_prime(dns_resolver_t *res) {
6971 isc_boolean_t want_priming = ISC_FALSE;
6972 dns_rdataset_t *rdataset;
6973 isc_result_t result;
6974
6975 REQUIRE(VALID_RESOLVER(res));
6976 REQUIRE(res->frozen);
6977
6978 RTRACE("dns_resolver_prime");
6979
6980 LOCK(&res->lock);
6981
6982 if (!res->exiting && !res->priming) {
6983 INSIST(res->primefetch == NULL);
6984 res->priming = ISC_TRUE;
6985 want_priming = ISC_TRUE;
6986 }
6987
6988 UNLOCK(&res->lock);
6989
6990 if (want_priming) {
6991 /*
6992 * To avoid any possible recursive locking problems, we
6993 * start the priming fetch like any other fetch, and holding
6994 * no resolver locks. No one else will try to start it
6995 * because we're the ones who set res->priming to true.
6996 * Any other callers of dns_resolver_prime() while we're
6997 * running will see that res->priming is already true and
6998 * do nothing.
6999 */
7000 RTRACE("priming");
7001 rdataset = isc_mem_get(res->mctx, sizeof(*rdataset));
7002 if (rdataset == NULL) {
7003 LOCK(&res->lock);
7004 INSIST(res->priming);
7005 INSIST(res->primefetch == NULL);
7006 res->priming = ISC_FALSE;
7007 UNLOCK(&res->lock);
7008 return;
7009 }
7010 dns_rdataset_init(rdataset);
7011 LOCK(&res->primelock);
7012 result = dns_resolver_createfetch(res, dns_rootname,
7013 dns_rdatatype_ns,
7014 NULL, NULL, NULL, 0,
7015 res->buckets[0].task,
7016 prime_done,
7017 res, rdataset, NULL,
7018 &res->primefetch);
7019 UNLOCK(&res->primelock);
7020 if (result != ISC_R_SUCCESS) {
7021 LOCK(&res->lock);
7022 INSIST(res->priming);
7023 res->priming = ISC_FALSE;
7024 UNLOCK(&res->lock);
7025 }
7026 }
7027 }
7028
7029 void
7030 dns_resolver_freeze(dns_resolver_t *res) {
7031
7032 /*
7033 * Freeze resolver.
7034 */
7035
7036 REQUIRE(VALID_RESOLVER(res));
7037 REQUIRE(!res->frozen);
7038
7039 res->frozen = ISC_TRUE;
7040 }
7041
7042 void
7043 dns_resolver_attach(dns_resolver_t *source, dns_resolver_t **targetp) {
7044 REQUIRE(VALID_RESOLVER(source));
7045 REQUIRE(targetp != NULL && *targetp == NULL);
7046
7047 RRTRACE(source, "attach");
7048 LOCK(&source->lock);
7049 REQUIRE(!source->exiting);
7050
7051 INSIST(source->references > 0);
7052 source->references++;
7053 INSIST(source->references != 0);
7054 UNLOCK(&source->lock);
7055
7056 *targetp = source;
7057 }
7058
7059 void
7060 dns_resolver_whenshutdown(dns_resolver_t *res, isc_task_t *task,
7061 isc_event_t **eventp)
7062 {
7063 isc_task_t *clone;
7064 isc_event_t *event;
7065
7066 REQUIRE(VALID_RESOLVER(res));
7067 REQUIRE(eventp != NULL);
7068
7069 event = *eventp;
7070 *eventp = NULL;
7071
7072 LOCK(&res->lock);
7073
7074 if (res->exiting && res->activebuckets == 0) {
7075 /*
7076 * We're already shutdown. Send the event.
7077 */
7078 event->ev_sender = res;
7079 isc_task_send(task, &event);
7080 } else {
7081 clone = NULL;
7082 isc_task_attach(task, &clone);
7083 event->ev_sender = clone;
7084 ISC_LIST_APPEND(res->whenshutdown, event, ev_link);
7085 }
7086
7087 UNLOCK(&res->lock);
7088 }
7089
7090 void
7091 dns_resolver_shutdown(dns_resolver_t *res) {
7092 unsigned int i;
7093 fetchctx_t *fctx;
7094 isc_socket_t *sock;
7095 isc_result_t result;
7096
7097 REQUIRE(VALID_RESOLVER(res));
7098
7099 RTRACE("shutdown");
7100
7101 LOCK(&res->lock);
7102
7103 if (!res->exiting) {
7104 RTRACE("exiting");
7105 res->exiting = ISC_TRUE;
7106
7107 for (i = 0; i < res->nbuckets; i++) {
7108 LOCK(&res->buckets[i].lock);
7109 for (fctx = ISC_LIST_HEAD(res->buckets[i].fctxs);
7110 fctx != NULL;
7111 fctx = ISC_LIST_NEXT(fctx, link))
7112 fctx_shutdown(fctx);
7113 if (res->dispatchv4 != NULL && !res->exclusivev4) {
7114 sock = dns_dispatch_getsocket(res->dispatchv4);
7115 isc_socket_cancel(sock, res->buckets[i].task,
7116 ISC_SOCKCANCEL_ALL);
7117 }
7118 if (res->dispatchv6 != NULL && !res->exclusivev6) {
7119 sock = dns_dispatch_getsocket(res->dispatchv6);
7120 isc_socket_cancel(sock, res->buckets[i].task,
7121 ISC_SOCKCANCEL_ALL);
7122 }
7123 res->buckets[i].exiting = ISC_TRUE;
7124 if (ISC_LIST_EMPTY(res->buckets[i].fctxs)) {
7125 INSIST(res->activebuckets > 0);
7126 res->activebuckets--;
7127 }
7128 UNLOCK(&res->buckets[i].lock);
7129 }
7130 if (res->activebuckets == 0)
7131 send_shutdown_events(res);
7132 result = isc_timer_reset(res->spillattimer,
7133 isc_timertype_inactive, NULL,
7134 NULL, ISC_TRUE);
7135 RUNTIME_CHECK(result == ISC_R_SUCCESS);
7136 }
7137
7138 UNLOCK(&res->lock);
7139 }
7140
7141 void
7142 dns_resolver_detach(dns_resolver_t **resp) {
7143 dns_resolver_t *res;
7144 isc_boolean_t need_destroy = ISC_FALSE;
7145
7146 REQUIRE(resp != NULL);
7147 res = *resp;
7148 REQUIRE(VALID_RESOLVER(res));
7149
7150 RTRACE("detach");
7151
7152 LOCK(&res->lock);
7153
7154 INSIST(res->references > 0);
7155 res->references--;
7156 if (res->references == 0) {
7157 INSIST(res->exiting && res->activebuckets == 0);
7158 need_destroy = ISC_TRUE;
7159 }
7160
7161 UNLOCK(&res->lock);
7162
7163 if (need_destroy)
7164 destroy(res);
7165
7166 *resp = NULL;
7167 }
7168
7169 static inline isc_boolean_t
7170 fctx_match(fetchctx_t *fctx, dns_name_t *name, dns_rdatatype_t type,
7171 unsigned int options)
7172 {
7173 if (fctx->type != type || fctx->options != options)
7174 return (ISC_FALSE);
7175 return (dns_name_equal(&fctx->name, name));
7176 }
7177
7178 static inline void
7179 log_fetch(dns_name_t *name, dns_rdatatype_t type) {
7180 char namebuf[DNS_NAME_FORMATSIZE];
7181 char typebuf[DNS_RDATATYPE_FORMATSIZE];
7182 int level = ISC_LOG_DEBUG(1);
7183
7184 if (! isc_log_wouldlog(dns_lctx, level))
7185 return;
7186
7187 dns_name_format(name, namebuf, sizeof(namebuf));
7188 dns_rdatatype_format(type, typebuf, sizeof(typebuf));
7189
7190 isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
7191 DNS_LOGMODULE_RESOLVER, level,
7192 "createfetch: %s %s", namebuf, typebuf);
7193 }
7194
7195 isc_result_t
7196 dns_resolver_createfetch(dns_resolver_t *res, dns_name_t *name,
7197 dns_rdatatype_t type,
7198 dns_name_t *domain, dns_rdataset_t *nameservers,
7199 dns_forwarders_t *forwarders,
7200 unsigned int options, isc_task_t *task,
7201 isc_taskaction_t action, void *arg,
7202 dns_rdataset_t *rdataset,
7203 dns_rdataset_t *sigrdataset,
7204 dns_fetch_t **fetchp)
7205 {
7206 return (dns_resolver_createfetch2(res, name, type, domain,
7207 nameservers, forwarders, NULL, 0,
7208 options, task, action, arg,
7209 rdataset, sigrdataset, fetchp));
7210 }
7211
7212 isc_result_t
7213 dns_resolver_createfetch2(dns_resolver_t *res, dns_name_t *name,
7214 dns_rdatatype_t type,
7215 dns_name_t *domain, dns_rdataset_t *nameservers,
7216 dns_forwarders_t *forwarders,
7217 isc_sockaddr_t *client, dns_messageid_t id,
7218 unsigned int options, isc_task_t *task,
7219 isc_taskaction_t action, void *arg,
7220 dns_rdataset_t *rdataset,
7221 dns_rdataset_t *sigrdataset,
7222 dns_fetch_t **fetchp)
7223 {
7224 dns_fetch_t *fetch;
7225 fetchctx_t *fctx = NULL;
7226 isc_result_t result = ISC_R_SUCCESS;
7227 unsigned int bucketnum;
7228 isc_boolean_t new_fctx = ISC_FALSE;
7229 isc_event_t *event;
7230 unsigned int count = 0;
7231 unsigned int spillat;
7232 unsigned int spillatmin;
7233
7234 UNUSED(forwarders);
7235
7236 REQUIRE(VALID_RESOLVER(res));
7237 REQUIRE(res->frozen);
7238 /* XXXRTH Check for meta type */
7239 if (domain != NULL) {
7240 REQUIRE(DNS_RDATASET_VALID(nameservers));
7241 REQUIRE(nameservers->type == dns_rdatatype_ns);
7242 } else
7243 REQUIRE(nameservers == NULL);
7244 REQUIRE(forwarders == NULL);
7245 REQUIRE(!dns_rdataset_isassociated(rdataset));
7246 REQUIRE(sigrdataset == NULL ||
7247 !dns_rdataset_isassociated(sigrdataset));
7248 REQUIRE(fetchp != NULL && *fetchp == NULL);
7249
7250 log_fetch(name, type);
7251
7252 /*
7253 * XXXRTH use a mempool?
7254 */
7255 fetch = isc_mem_get(res->mctx, sizeof(*fetch));
7256 if (fetch == NULL)
7257 return (ISC_R_NOMEMORY);
7258
7259 bucketnum = dns_name_fullhash(name, ISC_FALSE) % res->nbuckets;
7260
7261 LOCK(&res->lock);
7262 spillat = res->spillat;
7263 spillatmin = res->spillatmin;
7264 UNLOCK(&res->lock);
7265 LOCK(&res->buckets[bucketnum].lock);
7266
7267 if (res->buckets[bucketnum].exiting) {
7268 result = ISC_R_SHUTTINGDOWN;
7269 goto unlock;
7270 }
7271
7272 if ((options & DNS_FETCHOPT_UNSHARED) == 0) {
7273 for (fctx = ISC_LIST_HEAD(res->buckets[bucketnum].fctxs);
7274 fctx != NULL;
7275 fctx = ISC_LIST_NEXT(fctx, link)) {
7276 if (fctx_match(fctx, name, type, options))
7277 break;
7278 }
7279 }
7280
7281 /*
7282 * Is this a duplicate?
7283 */
7284 if (fctx != NULL && client != NULL) {
7285 dns_fetchevent_t *fevent;
7286 for (fevent = ISC_LIST_HEAD(fctx->events);
7287 fevent != NULL;
7288 fevent = ISC_LIST_NEXT(fevent, ev_link)) {
7289 if (fevent->client != NULL && fevent->id == id &&
7290 isc_sockaddr_equal(fevent->client, client)) {
7291 result = DNS_R_DUPLICATE;
7292 goto unlock;
7293 }
7294 count++;
7295 }
7296 }
7297 if (count >= spillatmin && spillatmin != 0) {
7298 INSIST(fctx != NULL);
7299 if (count >= spillat)
7300 fctx->spilled = ISC_TRUE;
7301 if (fctx->spilled) {
7302 result = DNS_R_DROP;
7303 goto unlock;
7304 }
7305 }
7306
7307 /*
7308 * If we didn't have a fetch, would attach to a done fetch, this
7309 * fetch has already cloned its results, or if the fetch has gone
7310 * "idle" (no one was interested in it), we need to start a new
7311 * fetch instead of joining with the existing one.
7312 */
7313 if (fctx == NULL ||
7314 fctx->state == fetchstate_done ||
7315 fctx->cloned ||
7316 ISC_LIST_EMPTY(fctx->events)) {
7317 fctx = NULL;
7318 result = fctx_create(res, name, type, domain, nameservers,
7319 options, bucketnum, &fctx);
7320 if (result != ISC_R_SUCCESS)
7321 goto unlock;
7322 new_fctx = ISC_TRUE;
7323 }
7324
7325 result = fctx_join(fctx, task, client, id, action, arg,
7326 rdataset, sigrdataset, fetch);
7327 if (new_fctx) {
7328 if (result == ISC_R_SUCCESS) {
7329 /*
7330 * Launch this fctx.
7331 */
7332 event = &fctx->control_event;
7333 ISC_EVENT_INIT(event, sizeof(*event), 0, NULL,
7334 DNS_EVENT_FETCHCONTROL,
7335 fctx_start, fctx, NULL,
7336 NULL, NULL);
7337 isc_task_send(res->buckets[bucketnum].task, &event);
7338 } else {
7339 /*
7340 * We don't care about the result of fctx_destroy()
7341 * since we know we're not exiting.
7342 */
7343 (void)fctx_destroy(fctx);
7344 }
7345 }
7346
7347 unlock:
7348 UNLOCK(&res->buckets[bucketnum].lock);
7349
7350 if (result == ISC_R_SUCCESS) {
7351 FTRACE("created");
7352 *fetchp = fetch;
7353 } else
7354 isc_mem_put(res->mctx, fetch, sizeof(*fetch));
7355
7356 return (result);
7357 }
7358
7359 void
7360 dns_resolver_cancelfetch(dns_fetch_t *fetch) {
7361 fetchctx_t *fctx;
7362 dns_resolver_t *res;
7363 dns_fetchevent_t *event, *next_event;
7364 isc_task_t *etask;
7365
7366 REQUIRE(DNS_FETCH_VALID(fetch));
7367 fctx = fetch->private;
7368 REQUIRE(VALID_FCTX(fctx));
7369 res = fctx->res;
7370
7371 FTRACE("cancelfetch");
7372
7373 LOCK(&res->buckets[fctx->bucketnum].lock);
7374
7375 /*
7376 * Find the completion event for this fetch (as opposed
7377 * to those for other fetches that have joined the same
7378 * fctx) and send it with result = ISC_R_CANCELED.
7379 */
7380 event = NULL;
7381 if (fctx->state != fetchstate_done) {
7382 for (event = ISC_LIST_HEAD(fctx->events);
7383 event != NULL;
7384 event = next_event) {
7385 next_event = ISC_LIST_NEXT(event, ev_link);
7386 if (event->fetch == fetch) {
7387 ISC_LIST_UNLINK(fctx->events, event, ev_link);
7388 break;
7389 }
7390 }
7391 }
7392 if (event != NULL) {
7393 etask = event->ev_sender;
7394 event->ev_sender = fctx;
7395 event->result = ISC_R_CANCELED;
7396 isc_task_sendanddetach(&etask, ISC_EVENT_PTR(&event));
7397 }
7398 /*
7399 * The fctx continues running even if no fetches remain;
7400 * the answer is still cached.
7401 */
7402
7403 UNLOCK(&res->buckets[fctx->bucketnum].lock);
7404 }
7405
7406 void
7407 dns_resolver_destroyfetch(dns_fetch_t **fetchp) {
7408 dns_fetch_t *fetch;
7409 dns_resolver_t *res;
7410 dns_fetchevent_t *event, *next_event;
7411 fetchctx_t *fctx;
7412 unsigned int bucketnum;
7413 isc_boolean_t bucket_empty = ISC_FALSE;
7414
7415 REQUIRE(fetchp != NULL);
7416 fetch = *fetchp;
7417 REQUIRE(DNS_FETCH_VALID(fetch));
7418 fctx = fetch->private;
7419 REQUIRE(VALID_FCTX(fctx));
7420 res = fctx->res;
7421
7422 FTRACE("destroyfetch");
7423
7424 bucketnum = fctx->bucketnum;
7425 LOCK(&res->buckets[bucketnum].lock);
7426
7427 /*
7428 * Sanity check: the caller should have gotten its event before
7429 * trying to destroy the fetch.
7430 */
7431 event = NULL;
7432 if (fctx->state != fetchstate_done) {
7433 for (event = ISC_LIST_HEAD(fctx->events);
7434 event != NULL;
7435 event = next_event) {
7436 next_event = ISC_LIST_NEXT(event, ev_link);
7437 RUNTIME_CHECK(event->fetch != fetch);
7438 }
7439 }
7440
7441 INSIST(fctx->references > 0);
7442 fctx->references--;
7443 if (fctx->references == 0) {
7444 /*
7445 * No one cares about the result of this fetch anymore.
7446 */
7447 if (fctx->pending == 0 && fctx->nqueries == 0 &&
7448 ISC_LIST_EMPTY(fctx->validators) &&
7449 SHUTTINGDOWN(fctx)) {
7450 /*
7451 * This fctx is already shutdown; we were just
7452 * waiting for the last reference to go away.
7453 */
7454 bucket_empty = fctx_destroy(fctx);
7455 } else {
7456 /*
7457 * Initiate shutdown.
7458 */
7459 fctx_shutdown(fctx);
7460 }
7461 }
7462
7463 UNLOCK(&res->buckets[bucketnum].lock);
7464
7465 isc_mem_put(res->mctx, fetch, sizeof(*fetch));
7466 *fetchp = NULL;
7467
7468 if (bucket_empty)
7469 empty_bucket(res);
7470 }
7471
7472 void
7473 dns_resolver_logfetch(dns_fetch_t *fetch, isc_log_t *lctx,
7474 isc_logcategory_t *category, isc_logmodule_t *module,
7475 int level, isc_boolean_t duplicateok)
7476 {
7477 fetchctx_t *fctx;
7478 dns_resolver_t *res;
7479 char domainbuf[DNS_NAME_FORMATSIZE];
7480
7481 REQUIRE(DNS_FETCH_VALID(fetch));
7482 fctx = fetch->private;
7483 REQUIRE(VALID_FCTX(fctx));
7484 res = fctx->res;
7485
7486 LOCK(&res->buckets[fctx->bucketnum].lock);
7487
7488 INSIST(fctx->exitline >= 0);
7489 if (!fctx->logged || duplicateok) {
7490 dns_name_format(&fctx->domain, domainbuf, sizeof(domainbuf));
7491 isc_log_write(lctx, category, module, level,
7492 "fetch completed at %s:%d for %s in "
7493 "%" ISC_PRINT_QUADFORMAT "u."
7494 "%06" ISC_PRINT_QUADFORMAT "u: %s/%s "
7495 "[domain:%s,referral:%u,restart:%u,qrysent:%u,"
7496 "timeout:%u,lame:%u,neterr:%u,badresp:%u,"
7497 "adberr:%u,findfail:%u,valfail:%u]",
7498 __FILE__, fctx->exitline, fctx->info,
7499 fctx->duration / 1000000,
7500 fctx->duration % 1000000,
7501 isc_result_totext(fctx->result),
7502 isc_result_totext(fctx->vresult), domainbuf,
7503 fctx->referrals, fctx->restarts,
7504 fctx->querysent, fctx->timeouts, fctx->lamecount,
7505 fctx->neterr, fctx->badresp, fctx->adberr,
7506 fctx->findfail, fctx->valfail);
7507 fctx->logged = ISC_TRUE;
7508 }
7509
7510 UNLOCK(&res->buckets[fctx->bucketnum].lock);
7511 }
7512
7513 dns_dispatchmgr_t *
7514 dns_resolver_dispatchmgr(dns_resolver_t *resolver) {
7515 REQUIRE(VALID_RESOLVER(resolver));
7516 return (resolver->dispatchmgr);
7517 }
7518
7519 dns_dispatch_t *
7520 dns_resolver_dispatchv4(dns_resolver_t *resolver) {
7521 REQUIRE(VALID_RESOLVER(resolver));
7522 return (resolver->dispatchv4);
7523 }
7524
7525 dns_dispatch_t *
7526 dns_resolver_dispatchv6(dns_resolver_t *resolver) {
7527 REQUIRE(VALID_RESOLVER(resolver));
7528 return (resolver->dispatchv6);
7529 }
7530
7531 isc_socketmgr_t *
7532 dns_resolver_socketmgr(dns_resolver_t *resolver) {
7533 REQUIRE(VALID_RESOLVER(resolver));
7534 return (resolver->socketmgr);
7535 }
7536
7537 isc_taskmgr_t *
7538 dns_resolver_taskmgr(dns_resolver_t *resolver) {
7539 REQUIRE(VALID_RESOLVER(resolver));
7540 return (resolver->taskmgr);
7541 }
7542
7543 isc_uint32_t
7544 dns_resolver_getlamettl(dns_resolver_t *resolver) {
7545 REQUIRE(VALID_RESOLVER(resolver));
7546 return (resolver->lame_ttl);
7547 }
7548
7549 void
7550 dns_resolver_setlamettl(dns_resolver_t *resolver, isc_uint32_t lame_ttl) {
7551 REQUIRE(VALID_RESOLVER(resolver));
7552 resolver->lame_ttl = lame_ttl;
7553 }
7554
7555 unsigned int
7556 dns_resolver_nrunning(dns_resolver_t *resolver) {
7557 unsigned int n;
7558 LOCK(&resolver->nlock);
7559 n = resolver->nfctx;
7560 UNLOCK(&resolver->nlock);
7561 return (n);
7562 }
7563
7564 isc_result_t
7565 dns_resolver_addalternate(dns_resolver_t *resolver, isc_sockaddr_t *alt,
7566 dns_name_t *name, in_port_t port) {
7567 alternate_t *a;
7568 isc_result_t result;
7569
7570 REQUIRE(VALID_RESOLVER(resolver));
7571 REQUIRE(!resolver->frozen);
7572 REQUIRE((alt == NULL) ^ (name == NULL));
7573
7574 a = isc_mem_get(resolver->mctx, sizeof(*a));
7575 if (a == NULL)
7576 return (ISC_R_NOMEMORY);
7577 if (alt != NULL) {
7578 a->isaddress = ISC_TRUE;
7579 a->_u.addr = *alt;
7580 } else {
7581 a->isaddress = ISC_FALSE;
7582 a->_u._n.port = port;
7583 dns_name_init(&a->_u._n.name, NULL);
7584 result = dns_name_dup(name, resolver->mctx, &a->_u._n.name);
7585 if (result != ISC_R_SUCCESS) {
7586 isc_mem_put(resolver->mctx, a, sizeof(*a));
7587 return (result);
7588 }
7589 }
7590 ISC_LINK_INIT(a, link);
7591 ISC_LIST_APPEND(resolver->alternates, a, link);
7592
7593 return (ISC_R_SUCCESS);
7594 }
7595
7596 void
7597 dns_resolver_setudpsize(dns_resolver_t *resolver, isc_uint16_t udpsize) {
7598 REQUIRE(VALID_RESOLVER(resolver));
7599 resolver->udpsize = udpsize;
7600 }
7601
7602 isc_uint16_t
7603 dns_resolver_getudpsize(dns_resolver_t *resolver) {
7604 REQUIRE(VALID_RESOLVER(resolver));
7605 return (resolver->udpsize);
7606 }
7607
7608 static void
7609 free_algorithm(void *node, void *arg) {
7610 unsigned char *algorithms = node;
7611 isc_mem_t *mctx = arg;
7612
7613 isc_mem_put(mctx, algorithms, *algorithms);
7614 }
7615
7616 void
7617 dns_resolver_reset_algorithms(dns_resolver_t *resolver) {
7618
7619 REQUIRE(VALID_RESOLVER(resolver));
7620
7621 #if USE_ALGLOCK
7622 RWLOCK(&resolver->alglock, isc_rwlocktype_write);
7623 #endif
7624 if (resolver->algorithms != NULL)
7625 dns_rbt_destroy(&resolver->algorithms);
7626 #if USE_ALGLOCK
7627 RWUNLOCK(&resolver->alglock, isc_rwlocktype_write);
7628 #endif
7629 }
7630
7631 isc_result_t
7632 dns_resolver_disable_algorithm(dns_resolver_t *resolver, dns_name_t *name,
7633 unsigned int alg)
7634 {
7635 unsigned int len, mask;
7636 unsigned char *new;
7637 unsigned char *algorithms;
7638 isc_result_t result;
7639 dns_rbtnode_t *node = NULL;
7640
7641 REQUIRE(VALID_RESOLVER(resolver));
7642 if (alg > 255)
7643 return (ISC_R_RANGE);
7644
7645 #if USE_ALGLOCK
7646 RWLOCK(&resolver->alglock, isc_rwlocktype_write);
7647 #endif
7648 if (resolver->algorithms == NULL) {
7649 result = dns_rbt_create(resolver->mctx, free_algorithm,
7650 resolver->mctx, &resolver->algorithms);
7651 if (result != ISC_R_SUCCESS)
7652 goto cleanup;
7653 }
7654
7655 len = alg/8 + 2;
7656 mask = 1 << (alg%8);
7657
7658 result = dns_rbt_addnode(resolver->algorithms, name, &node);
7659
7660 if (result == ISC_R_SUCCESS || result == ISC_R_EXISTS) {
7661 algorithms = node->data;
7662 if (algorithms == NULL || len > *algorithms) {
7663 new = isc_mem_get(resolver->mctx, len);
7664 if (new == NULL) {
7665 result = ISC_R_NOMEMORY;
7666 goto cleanup;
7667 }
7668 memset(new, 0, len);
7669 if (algorithms != NULL)
7670 memcpy(new, algorithms, *algorithms);
7671 new[len-1] |= mask;
7672 *new = len;
7673 node->data = new;
7674 if (algorithms != NULL)
7675 isc_mem_put(resolver->mctx, algorithms,
7676 *algorithms);
7677 } else
7678 algorithms[len-1] |= mask;
7679 }
7680 result = ISC_R_SUCCESS;
7681 cleanup:
7682 #if USE_ALGLOCK
7683 RWUNLOCK(&resolver->alglock, isc_rwlocktype_write);
7684 #endif
7685 return (result);
7686 }
7687
7688 isc_boolean_t
7689 dns_resolver_algorithm_supported(dns_resolver_t *resolver, dns_name_t *name,
7690 unsigned int alg)
7691 {
7692 unsigned int len, mask;
7693 unsigned char *algorithms;
7694 void *data = NULL;
7695 isc_result_t result;
7696 isc_boolean_t found = ISC_FALSE;
7697
7698 REQUIRE(VALID_RESOLVER(resolver));
7699
7700 #if USE_ALGLOCK
7701 RWLOCK(&resolver->alglock, isc_rwlocktype_read);
7702 #endif
7703 if (resolver->algorithms == NULL)
7704 goto unlock;
7705 result = dns_rbt_findname(resolver->algorithms, name, 0, NULL, &data);
7706 if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
7707 len = alg/8 + 2;
7708 mask = 1 << (alg%8);
7709 algorithms = data;
7710 if (len <= *algorithms && (algorithms[len-1] & mask) != 0)
7711 found = ISC_TRUE;
7712 }
7713 unlock:
7714 #if USE_ALGLOCK
7715 RWUNLOCK(&resolver->alglock, isc_rwlocktype_read);
7716 #endif
7717 if (found)
7718 return (ISC_FALSE);
7719 return (dst_algorithm_supported(alg));
7720 }
7721
7722 isc_boolean_t
7723 dns_resolver_digest_supported(dns_resolver_t *resolver, unsigned int digest) {
7724
7725 UNUSED(resolver);
7726 return (dns_ds_digest_supported(digest));
7727 }
7728
7729 void
7730 dns_resolver_resetmustbesecure(dns_resolver_t *resolver) {
7731
7732 REQUIRE(VALID_RESOLVER(resolver));
7733
7734 #if USE_MBSLOCK
7735 RWLOCK(&resolver->mbslock, isc_rwlocktype_write);
7736 #endif
7737 if (resolver->mustbesecure != NULL)
7738 dns_rbt_destroy(&resolver->mustbesecure);
7739 #if USE_MBSLOCK
7740 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write);
7741 #endif
7742 }
7743
7744 static isc_boolean_t yes = ISC_TRUE, no = ISC_FALSE;
7745
7746 isc_result_t
7747 dns_resolver_setmustbesecure(dns_resolver_t *resolver, dns_name_t *name,
7748 isc_boolean_t value)
7749 {
7750 isc_result_t result;
7751
7752 REQUIRE(VALID_RESOLVER(resolver));
7753
7754 #if USE_MBSLOCK
7755 RWLOCK(&resolver->mbslock, isc_rwlocktype_write);
7756 #endif
7757 if (resolver->mustbesecure == NULL) {
7758 result = dns_rbt_create(resolver->mctx, NULL, NULL,
7759 &resolver->mustbesecure);
7760 if (result != ISC_R_SUCCESS)
7761 goto cleanup;
7762 }
7763 result = dns_rbt_addname(resolver->mustbesecure, name,
7764 value ? &yes : &no);
7765 cleanup:
7766 #if USE_MBSLOCK
7767 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_write);
7768 #endif
7769 return (result);
7770 }
7771
7772 isc_boolean_t
7773 dns_resolver_getmustbesecure(dns_resolver_t *resolver, dns_name_t *name) {
7774 void *data = NULL;
7775 isc_boolean_t value = ISC_FALSE;
7776 isc_result_t result;
7777
7778 REQUIRE(VALID_RESOLVER(resolver));
7779
7780 #if USE_MBSLOCK
7781 RWLOCK(&resolver->mbslock, isc_rwlocktype_read);
7782 #endif
7783 if (resolver->mustbesecure == NULL)
7784 goto unlock;
7785 result = dns_rbt_findname(resolver->mustbesecure, name, 0, NULL, &data);
7786 if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
7787 value = *(isc_boolean_t*)data;
7788 unlock:
7789 #if USE_MBSLOCK
7790 RWUNLOCK(&resolver->mbslock, isc_rwlocktype_read);
7791 #endif
7792 return (value);
7793 }
7794
7795 void
7796 dns_resolver_getclientsperquery(dns_resolver_t *resolver, isc_uint32_t *cur,
7797 isc_uint32_t *min, isc_uint32_t *max)
7798 {
7799 REQUIRE(VALID_RESOLVER(resolver));
7800
7801 LOCK(&resolver->lock);
7802 if (cur != NULL)
7803 *cur = resolver->spillat;
7804 if (min != NULL)
7805 *min = resolver->spillatmin;
7806 if (max != NULL)
7807 *max = resolver->spillatmax;
7808 UNLOCK(&resolver->lock);
7809 }
7810
7811 void
7812 dns_resolver_setclientsperquery(dns_resolver_t *resolver, isc_uint32_t min,
7813 isc_uint32_t max)
7814 {
7815 REQUIRE(VALID_RESOLVER(resolver));
7816
7817 LOCK(&resolver->lock);
7818 resolver->spillatmin = resolver->spillat = min;
7819 resolver->spillatmax = max;
7820 UNLOCK(&resolver->lock);
7821 }
7822
7823 isc_boolean_t
7824 dns_resolver_getzeronosoattl(dns_resolver_t *resolver) {
7825 REQUIRE(VALID_RESOLVER(resolver));
7826
7827 return (resolver->zero_no_soa_ttl);
7828 }
7829
7830 void
7831 dns_resolver_setzeronosoattl(dns_resolver_t *resolver, isc_boolean_t state) {
7832 REQUIRE(VALID_RESOLVER(resolver));
7833
7834 resolver->zero_no_soa_ttl = state;
7835 }
7836
7837 unsigned int
7838 dns_resolver_getoptions(dns_resolver_t *resolver) {
7839 REQUIRE(VALID_RESOLVER(resolver));
7840
7841 return (resolver->options);
7842 }
DragonFly BSD