Import bind 9.5.2 vendor sources.
[dragonfly.git] / contrib / bind-9.5.2 / lib / dns / adb.c
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: adb.c,v 1.233.36.14 2009/02/03 22:35:00 jinmei Exp $ */
19
20 /*! \file
21  *
22  * \note
23  * In finds, if task == NULL, no events will be generated, and no events
24  * have been sent.  If task != NULL but taskaction == NULL, an event has been
25  * posted but not yet freed.  If neither are NULL, no event was posted.
26  *
27  */
28
29 #include <config.h>
30
31 #include <limits.h>
32
33 #include <isc/mutexblock.h>
34 #include <isc/netaddr.h>
35 #include <isc/random.h>
36 #include <isc/stats.h>
37 #include <isc/string.h>         /* Required for HP/UX (and others?) */
38 #include <isc/task.h>
39 #include <isc/util.h>
40
41 #include <dns/adb.h>
42 #include <dns/db.h>
43 #include <dns/events.h>
44 #include <dns/log.h>
45 #include <dns/rdata.h>
46 #include <dns/rdataset.h>
47 #include <dns/rdatastruct.h>
48 #include <dns/rdatatype.h>
49 #include <dns/resolver.h>
50 #include <dns/result.h>
51 #include <dns/stats.h>
52
53 #define DNS_ADB_MAGIC             ISC_MAGIC('D', 'a', 'd', 'b')
54 #define DNS_ADB_VALID(x)          ISC_MAGIC_VALID(x, DNS_ADB_MAGIC)
55 #define DNS_ADBNAME_MAGIC         ISC_MAGIC('a', 'd', 'b', 'N')
56 #define DNS_ADBNAME_VALID(x)      ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC)
57 #define DNS_ADBNAMEHOOK_MAGIC     ISC_MAGIC('a', 'd', 'N', 'H')
58 #define DNS_ADBNAMEHOOK_VALID(x)  ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC)
59 #define DNS_ADBLAMEINFO_MAGIC     ISC_MAGIC('a', 'd', 'b', 'Z')
60 #define DNS_ADBLAMEINFO_VALID(x)  ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC)
61 #define DNS_ADBENTRY_MAGIC        ISC_MAGIC('a', 'd', 'b', 'E')
62 #define DNS_ADBENTRY_VALID(x)     ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC)
63 #define DNS_ADBFETCH_MAGIC        ISC_MAGIC('a', 'd', 'F', '4')
64 #define DNS_ADBFETCH_VALID(x)     ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC)
65 #define DNS_ADBFETCH6_MAGIC       ISC_MAGIC('a', 'd', 'F', '6')
66 #define DNS_ADBFETCH6_VALID(x)    ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC)
67
68 /*!
69  * The number of buckets needs to be a prime (for good hashing).
70  *
71  * XXXRTH  How many buckets do we need?
72  */
73 #define NBUCKETS               1009     /*%< how many buckets for names/addrs */
74
75 /*!
76  * For type 3 negative cache entries, we will remember that the address is
77  * broken for this long.  XXXMLG This is also used for actual addresses, too.
78  * The intent is to keep us from constantly asking about A/AAAA records
79  * if the zone has extremely low TTLs.
80  */
81 #define ADB_CACHE_MINIMUM       10      /*%< seconds */
82 #define ADB_CACHE_MAXIMUM       86400   /*%< seconds (86400 = 24 hours) */
83 #define ADB_ENTRY_WINDOW        1800    /*%< seconds */
84
85 /*%
86  * The period in seconds after which an ADB name entry is regarded as stale
87  * and forced to be cleaned up.
88  * TODO: This should probably be configurable at run-time.
89  */
90 #ifndef ADB_STALE_MARGIN
91 #define ADB_STALE_MARGIN        1800
92 #endif
93
94 #define FREE_ITEMS              64      /*%< free count for memory pools */
95 #define FILL_COUNT              16      /*%< fill count for memory pools */
96
97 #define DNS_ADB_INVALIDBUCKET (-1)      /*%< invalid bucket address */
98
99 #define DNS_ADB_MINADBSIZE      (1024*1024)     /*%< 1 Megabyte */
100
101 typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t;
102 typedef struct dns_adbnamehook dns_adbnamehook_t;
103 typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t;
104 typedef struct dns_adblameinfo dns_adblameinfo_t;
105 typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t;
106 typedef struct dns_adbfetch dns_adbfetch_t;
107 typedef struct dns_adbfetch6 dns_adbfetch6_t;
108
109 /*% dns adb structure */
110 struct dns_adb {
111         unsigned int                    magic;
112
113         isc_mutex_t                     lock;
114         isc_mutex_t                     reflock; /*%< Covers irefcnt, erefcnt */
115         isc_mutex_t                     overmemlock; /*%< Covers overmem */
116         isc_mem_t                      *mctx;
117         dns_view_t                     *view;
118
119         isc_taskmgr_t                  *taskmgr;
120         isc_task_t                     *task;
121         isc_boolean_t                   overmem;
122
123         isc_interval_t                  tick_interval;
124         int                             next_cleanbucket;
125
126         unsigned int                    irefcnt;
127         unsigned int                    erefcnt;
128
129         isc_mutex_t                     mplock;
130         isc_mempool_t                  *nmp;    /*%< dns_adbname_t */
131         isc_mempool_t                  *nhmp;   /*%< dns_adbnamehook_t */
132         isc_mempool_t                  *limp;   /*%< dns_adblameinfo_t */
133         isc_mempool_t                  *emp;    /*%< dns_adbentry_t */
134         isc_mempool_t                  *ahmp;   /*%< dns_adbfind_t */
135         isc_mempool_t                  *aimp;   /*%< dns_adbaddrinfo_t */
136         isc_mempool_t                  *afmp;   /*%< dns_adbfetch_t */
137
138         /*!
139          * Bucketized locks and lists for names.
140          *
141          * XXXRTH  Have a per-bucket structure that contains all of these?
142          */
143         dns_adbnamelist_t               names[NBUCKETS];
144         dns_adbnamelist_t               deadnames[NBUCKETS];
145         /*% See dns_adbnamelist_t */
146         isc_mutex_t                     namelocks[NBUCKETS];
147         /*% See dns_adbnamelist_t */
148         isc_boolean_t                   name_sd[NBUCKETS];
149         /*% See dns_adbnamelist_t */
150         unsigned int                    name_refcnt[NBUCKETS];
151
152         /*!
153          * Bucketized locks for entries.
154          *
155          * XXXRTH  Have a per-bucket structure that contains all of these?
156          */
157         dns_adbentrylist_t              entries[NBUCKETS];
158         dns_adbentrylist_t              deadentries[NBUCKETS];
159         isc_mutex_t                     entrylocks[NBUCKETS];
160         isc_boolean_t                   entry_sd[NBUCKETS]; /*%< shutting down */
161         unsigned int                    entry_refcnt[NBUCKETS];
162
163         isc_event_t                     cevent;
164         isc_boolean_t                   cevent_sent;
165         isc_boolean_t                   shutting_down;
166         isc_eventlist_t                 whenshutdown;
167 };
168
169 /*
170  * XXXMLG  Document these structures.
171  */
172
173 /*% dns_adbname structure */
174 struct dns_adbname {
175         unsigned int                    magic;
176         dns_name_t                      name;
177         dns_adb_t                      *adb;
178         unsigned int                    partial_result;
179         unsigned int                    flags;
180         int                             lock_bucket;
181         dns_name_t                      target;
182         isc_stdtime_t                   expire_target;
183         isc_stdtime_t                   expire_v4;
184         isc_stdtime_t                   expire_v6;
185         unsigned int                    chains;
186         dns_adbnamehooklist_t           v4;
187         dns_adbnamehooklist_t           v6;
188         dns_adbfetch_t                 *fetch_a;
189         dns_adbfetch_t                 *fetch_aaaa;
190         unsigned int                    fetch_err;
191         unsigned int                    fetch6_err;
192         dns_adbfindlist_t               finds;
193         /* for LRU-based management */
194         isc_stdtime_t                   last_used;
195
196         ISC_LINK(dns_adbname_t)         plink;
197 };
198
199 /*% The adbfetch structure */
200 struct dns_adbfetch {
201         unsigned int                    magic;
202         dns_fetch_t                    *fetch;
203         dns_rdataset_t                  rdataset;
204 };
205
206 /*%
207  * This is a small widget that dangles off a dns_adbname_t.  It contains a
208  * pointer to the address information about this host, and a link to the next
209  * namehook that will contain the next address this host has.
210  */
211 struct dns_adbnamehook {
212         unsigned int                    magic;
213         dns_adbentry_t                 *entry;
214         ISC_LINK(dns_adbnamehook_t)     plink;
215 };
216
217 /*%
218  * This is a small widget that holds qname-specific information about an
219  * address.  Currently limited to lameness, but could just as easily be
220  * extended to other types of information about zones.
221  */
222 struct dns_adblameinfo {
223         unsigned int                    magic;
224
225         dns_name_t                      qname;
226         dns_rdatatype_t                 qtype;
227         isc_stdtime_t                   lame_timer;
228
229         ISC_LINK(dns_adblameinfo_t)     plink;
230 };
231
232 /*%
233  * An address entry.  It holds quite a bit of information about addresses,
234  * including edns state (in "flags"), rtt, and of course the address of
235  * the host.
236  */
237 struct dns_adbentry {
238         unsigned int                    magic;
239
240         int                             lock_bucket;
241         unsigned int                    refcnt;
242
243         unsigned int                    flags;
244         unsigned int                    srtt;
245         isc_sockaddr_t                  sockaddr;
246
247         isc_stdtime_t                   expires;
248         /*%<
249          * A nonzero 'expires' field indicates that the entry should
250          * persist until that time.  This allows entries found
251          * using dns_adb_findaddrinfo() to persist for a limited time
252          * even though they are not necessarily associated with a
253          * name.
254          */
255
256         ISC_LIST(dns_adblameinfo_t)     lameinfo;
257         ISC_LINK(dns_adbentry_t)        plink;
258 };
259
260 /*
261  * Internal functions (and prototypes).
262  */
263 static inline dns_adbname_t *new_adbname(dns_adb_t *, dns_name_t *);
264 static inline void free_adbname(dns_adb_t *, dns_adbname_t **);
265 static inline dns_adbnamehook_t *new_adbnamehook(dns_adb_t *,
266                                                  dns_adbentry_t *);
267 static inline void free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **);
268 static inline dns_adblameinfo_t *new_adblameinfo(dns_adb_t *, dns_name_t *,
269                                                  dns_rdatatype_t);
270 static inline void free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **);
271 static inline dns_adbentry_t *new_adbentry(dns_adb_t *);
272 static inline void free_adbentry(dns_adb_t *, dns_adbentry_t **);
273 static inline dns_adbfind_t *new_adbfind(dns_adb_t *);
274 static inline isc_boolean_t free_adbfind(dns_adb_t *, dns_adbfind_t **);
275 static inline dns_adbaddrinfo_t *new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *,
276                                                  in_port_t);
277 static inline dns_adbfetch_t *new_adbfetch(dns_adb_t *);
278 static inline void free_adbfetch(dns_adb_t *, dns_adbfetch_t **);
279 static inline dns_adbname_t *find_name_and_lock(dns_adb_t *, dns_name_t *,
280                                                 unsigned int, int *);
281 static inline dns_adbentry_t *find_entry_and_lock(dns_adb_t *,
282                                                   isc_sockaddr_t *, int *,
283                                                   isc_stdtime_t);
284 static void dump_adb(dns_adb_t *, FILE *, isc_boolean_t debug, isc_stdtime_t);
285 static void print_dns_name(FILE *, dns_name_t *);
286 static void print_namehook_list(FILE *, const char *legend,
287                                 dns_adbnamehooklist_t *list,
288                                 isc_boolean_t debug,
289                                 isc_stdtime_t now);
290 static void print_find_list(FILE *, dns_adbname_t *);
291 static void print_fetch_list(FILE *, dns_adbname_t *);
292 static inline isc_boolean_t dec_adb_irefcnt(dns_adb_t *);
293 static inline void inc_adb_irefcnt(dns_adb_t *);
294 static inline void inc_adb_erefcnt(dns_adb_t *);
295 static inline void inc_entry_refcnt(dns_adb_t *, dns_adbentry_t *,
296                                     isc_boolean_t);
297 static inline isc_boolean_t dec_entry_refcnt(dns_adb_t *, dns_adbentry_t *,
298                                              isc_boolean_t);
299 static inline void violate_locking_hierarchy(isc_mutex_t *, isc_mutex_t *);
300 static isc_boolean_t clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *);
301 static void clean_target(dns_adb_t *, dns_name_t *);
302 static void clean_finds_at_name(dns_adbname_t *, isc_eventtype_t,
303                                 unsigned int);
304 static isc_boolean_t check_expire_namehooks(dns_adbname_t *, isc_stdtime_t);
305 static isc_boolean_t check_expire_entry(dns_adb_t *, dns_adbentry_t **,
306                                         isc_stdtime_t);
307 static void cancel_fetches_at_name(dns_adbname_t *);
308 static isc_result_t dbfind_name(dns_adbname_t *, isc_stdtime_t,
309                                 dns_rdatatype_t);
310 static isc_result_t fetch_name(dns_adbname_t *, isc_boolean_t,
311                                dns_rdatatype_t);
312 static inline void check_exit(dns_adb_t *);
313 static void destroy(dns_adb_t *);
314 static isc_boolean_t shutdown_names(dns_adb_t *);
315 static isc_boolean_t shutdown_entries(dns_adb_t *);
316 static inline void link_name(dns_adb_t *, int, dns_adbname_t *);
317 static inline isc_boolean_t unlink_name(dns_adb_t *, dns_adbname_t *);
318 static inline void link_entry(dns_adb_t *, int, dns_adbentry_t *);
319 static inline isc_boolean_t unlink_entry(dns_adb_t *, dns_adbentry_t *);
320 static isc_boolean_t kill_name(dns_adbname_t **, isc_eventtype_t);
321 static void water(void *, int);
322 static void dump_entry(FILE *, dns_adbentry_t *, isc_boolean_t, isc_stdtime_t);
323
324 /*
325  * MUST NOT overlap DNS_ADBFIND_* flags!
326  */
327 #define FIND_EVENT_SENT         0x40000000
328 #define FIND_EVENT_FREED        0x80000000
329 #define FIND_EVENTSENT(h)       (((h)->flags & FIND_EVENT_SENT) != 0)
330 #define FIND_EVENTFREED(h)      (((h)->flags & FIND_EVENT_FREED) != 0)
331
332 #define NAME_NEEDS_POKE         0x80000000
333 #define NAME_IS_DEAD            0x40000000
334 #define NAME_HINT_OK            DNS_ADBFIND_HINTOK
335 #define NAME_GLUE_OK            DNS_ADBFIND_GLUEOK
336 #define NAME_STARTATZONE        DNS_ADBFIND_STARTATZONE
337 #define NAME_DEAD(n)            (((n)->flags & NAME_IS_DEAD) != 0)
338 #define NAME_NEEDSPOKE(n)       (((n)->flags & NAME_NEEDS_POKE) != 0)
339 #define NAME_GLUEOK(n)          (((n)->flags & NAME_GLUE_OK) != 0)
340 #define NAME_HINTOK(n)          (((n)->flags & NAME_HINT_OK) != 0)
341
342 /*
343  * Private flag(s) for entries.
344  * MUST NOT overlap FCTX_ADDRINFO_xxx and DNS_FETCHOPT_NOEDNS0.
345  */
346 #define ENTRY_IS_DEAD           0x80000000
347
348 /*
349  * To the name, address classes are all that really exist.  If it has a
350  * V6 address it doesn't care if it came from a AAAA query.
351  */
352 #define NAME_HAS_V4(n)          (!ISC_LIST_EMPTY((n)->v4))
353 #define NAME_HAS_V6(n)          (!ISC_LIST_EMPTY((n)->v6))
354 #define NAME_HAS_ADDRS(n)       (NAME_HAS_V4(n) || NAME_HAS_V6(n))
355
356 /*
357  * Fetches are broken out into A and AAAA types.  In some cases,
358  * however, it makes more sense to test for a particular class of fetches,
359  * like V4 or V6 above.
360  * Note: since we have removed the support of A6 in adb, FETCH_A and FETCH_AAAA
361  * are now equal to FETCH_V4 and FETCH_V6, respectively.
362  */
363 #define NAME_FETCH_A(n)         ((n)->fetch_a != NULL)
364 #define NAME_FETCH_AAAA(n)      ((n)->fetch_aaaa != NULL)
365 #define NAME_FETCH_V4(n)        (NAME_FETCH_A(n))
366 #define NAME_FETCH_V6(n)        (NAME_FETCH_AAAA(n))
367 #define NAME_FETCH(n)           (NAME_FETCH_V4(n) || NAME_FETCH_V6(n))
368
369 /*
370  * Find options and tests to see if there are addresses on the list.
371  */
372 #define FIND_WANTEVENT(fn)      (((fn)->options & DNS_ADBFIND_WANTEVENT) != 0)
373 #define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0)
374 #define FIND_AVOIDFETCHES(fn)   (((fn)->options & DNS_ADBFIND_AVOIDFETCHES) \
375                                  != 0)
376 #define FIND_STARTATZONE(fn)    (((fn)->options & DNS_ADBFIND_STARTATZONE) \
377                                  != 0)
378 #define FIND_HINTOK(fn)         (((fn)->options & DNS_ADBFIND_HINTOK) != 0)
379 #define FIND_GLUEOK(fn)         (((fn)->options & DNS_ADBFIND_GLUEOK) != 0)
380 #define FIND_HAS_ADDRS(fn)      (!ISC_LIST_EMPTY((fn)->list))
381 #define FIND_RETURNLAME(fn)     (((fn)->options & DNS_ADBFIND_RETURNLAME) != 0)
382
383 /*
384  * These are currently used on simple unsigned ints, so they are
385  * not really associated with any particular type.
386  */
387 #define WANT_INET(x)            (((x) & DNS_ADBFIND_INET) != 0)
388 #define WANT_INET6(x)           (((x) & DNS_ADBFIND_INET6) != 0)
389
390 #define EXPIRE_OK(exp, now)     ((exp == INT_MAX) || (exp < now))
391
392 /*
393  * Find out if the flags on a name (nf) indicate if it is a hint or
394  * glue, and compare this to the appropriate bits set in o, to see if
395  * this is ok.
396  */
397 #define GLUE_OK(nf, o) (!NAME_GLUEOK(nf) || (((o) & DNS_ADBFIND_GLUEOK) != 0))
398 #define HINT_OK(nf, o) (!NAME_HINTOK(nf) || (((o) & DNS_ADBFIND_HINTOK) != 0))
399 #define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o))
400 #define STARTATZONE_MATCHES(nf, o) (((nf)->flags & NAME_STARTATZONE) == \
401                                     ((o) & DNS_ADBFIND_STARTATZONE))
402
403 #define ENTER_LEVEL             ISC_LOG_DEBUG(50)
404 #define EXIT_LEVEL              ENTER_LEVEL
405 #define CLEAN_LEVEL             ISC_LOG_DEBUG(100)
406 #define DEF_LEVEL               ISC_LOG_DEBUG(5)
407 #define NCACHE_LEVEL            ISC_LOG_DEBUG(20)
408
409 #define NCACHE_RESULT(r)        ((r) == DNS_R_NCACHENXDOMAIN || \
410                                  (r) == DNS_R_NCACHENXRRSET)
411 #define AUTH_NX(r)              ((r) == DNS_R_NXDOMAIN || \
412                                  (r) == DNS_R_NXRRSET)
413 #define NXDOMAIN_RESULT(r)      ((r) == DNS_R_NXDOMAIN || \
414                                  (r) == DNS_R_NCACHENXDOMAIN)
415 #define NXRRSET_RESULT(r)       ((r) == DNS_R_NCACHENXRRSET || \
416                                  (r) == DNS_R_NXRRSET || \
417                                  (r) == DNS_R_HINTNXRRSET)
418
419 /*
420  * Error state rankings.
421  */
422
423 #define FIND_ERR_SUCCESS                0  /* highest rank */
424 #define FIND_ERR_CANCELED               1
425 #define FIND_ERR_FAILURE                2
426 #define FIND_ERR_NXDOMAIN               3
427 #define FIND_ERR_NXRRSET                4
428 #define FIND_ERR_UNEXPECTED             5
429 #define FIND_ERR_NOTFOUND               6
430 #define FIND_ERR_MAX                    7
431
432 static const char *errnames[] = {
433         "success",
434         "canceled",
435         "failure",
436         "nxdomain",
437         "nxrrset",
438         "unexpected",
439         "not_found"
440 };
441
442 #define NEWERR(old, new)        (ISC_MIN((old), (new)))
443
444 static isc_result_t find_err_map[FIND_ERR_MAX] = {
445         ISC_R_SUCCESS,
446         ISC_R_CANCELED,
447         ISC_R_FAILURE,
448         DNS_R_NXDOMAIN,
449         DNS_R_NXRRSET,
450         ISC_R_UNEXPECTED,
451         ISC_R_NOTFOUND          /* not YET found */
452 };
453
454 static void
455 DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);
456
457 static void
458 DP(int level, const char *format, ...) {
459         va_list args;
460
461         va_start(args, format);
462         isc_log_vwrite(dns_lctx,
463                        DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
464                        level, format, args);
465         va_end(args);
466 }
467
468 /*%
469  * Increment resolver-related statistics counters.
470  */
471 static inline void
472 inc_stats(dns_adb_t *adb, isc_statscounter_t counter) {
473         if (adb->view->resstats != NULL)
474                 isc_stats_increment(adb->view->resstats, counter);
475 }
476
477 static inline dns_ttl_t
478 ttlclamp(dns_ttl_t ttl) {
479         if (ttl < ADB_CACHE_MINIMUM)
480                 ttl = ADB_CACHE_MINIMUM;
481         if (ttl > ADB_CACHE_MAXIMUM)
482                 ttl = ADB_CACHE_MAXIMUM;
483
484         return (ttl);
485 }
486
487 /*
488  * Requires the adbname bucket be locked and that no entry buckets be locked.
489  *
490  * This code handles A and AAAA rdatasets only.
491  */
492 static isc_result_t
493 import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset,
494                 isc_stdtime_t now)
495 {
496         isc_result_t result;
497         dns_adb_t *adb;
498         dns_adbnamehook_t *nh;
499         dns_adbnamehook_t *anh;
500         dns_rdata_t rdata = DNS_RDATA_INIT;
501         struct in_addr ina;
502         struct in6_addr in6a;
503         isc_sockaddr_t sockaddr;
504         dns_adbentry_t *foundentry;  /* NO CLEAN UP! */
505         int addr_bucket;
506         isc_boolean_t new_addresses_added;
507         dns_rdatatype_t rdtype;
508         unsigned int findoptions;
509         dns_adbnamehooklist_t *hookhead;
510
511         INSIST(DNS_ADBNAME_VALID(adbname));
512         adb = adbname->adb;
513         INSIST(DNS_ADB_VALID(adb));
514
515         rdtype = rdataset->type;
516         INSIST((rdtype == dns_rdatatype_a) || (rdtype == dns_rdatatype_aaaa));
517         if (rdtype == dns_rdatatype_a)
518                 findoptions = DNS_ADBFIND_INET;
519         else
520                 findoptions = DNS_ADBFIND_INET6;
521
522         addr_bucket = DNS_ADB_INVALIDBUCKET;
523         new_addresses_added = ISC_FALSE;
524
525         nh = NULL;
526         result = dns_rdataset_first(rdataset);
527         while (result == ISC_R_SUCCESS) {
528                 dns_rdata_reset(&rdata);
529                 dns_rdataset_current(rdataset, &rdata);
530                 if (rdtype == dns_rdatatype_a) {
531                         INSIST(rdata.length == 4);
532                         memcpy(&ina.s_addr, rdata.data, 4);
533                         isc_sockaddr_fromin(&sockaddr, &ina, 0);
534                         hookhead = &adbname->v4;
535                 } else {
536                         INSIST(rdata.length == 16);
537                         memcpy(in6a.s6_addr, rdata.data, 16);
538                         isc_sockaddr_fromin6(&sockaddr, &in6a, 0);
539                         hookhead = &adbname->v6;
540                 }
541
542                 INSIST(nh == NULL);
543                 nh = new_adbnamehook(adb, NULL);
544                 if (nh == NULL) {
545                         adbname->partial_result |= findoptions;
546                         result = ISC_R_NOMEMORY;
547                         goto fail;
548                 }
549
550                 foundentry = find_entry_and_lock(adb, &sockaddr, &addr_bucket,
551                                                  now);
552                 if (foundentry == NULL) {
553                         dns_adbentry_t *entry;
554
555                         entry = new_adbentry(adb);
556                         if (entry == NULL) {
557                                 adbname->partial_result |= findoptions;
558                                 result = ISC_R_NOMEMORY;
559                                 goto fail;
560                         }
561
562                         entry->sockaddr = sockaddr;
563                         entry->refcnt = 1;
564
565                         nh->entry = entry;
566
567                         link_entry(adb, addr_bucket, entry);
568                 } else {
569                         for (anh = ISC_LIST_HEAD(*hookhead);
570                              anh != NULL;
571                              anh = ISC_LIST_NEXT(anh, plink))
572                                 if (anh->entry == foundentry)
573                                         break;
574                         if (anh == NULL) {
575                                 foundentry->refcnt++;
576                                 nh->entry = foundentry;
577                         } else
578                                 free_adbnamehook(adb, &nh);
579                 }
580
581                 new_addresses_added = ISC_TRUE;
582                 if (nh != NULL)
583                         ISC_LIST_APPEND(*hookhead, nh, plink);
584                 nh = NULL;
585                 result = dns_rdataset_next(rdataset);
586         }
587
588  fail:
589         if (nh != NULL)
590                 free_adbnamehook(adb, &nh);
591
592         if (addr_bucket != DNS_ADB_INVALIDBUCKET)
593                 UNLOCK(&adb->entrylocks[addr_bucket]);
594
595         if (rdataset->trust == dns_trust_glue ||
596             rdataset->trust == dns_trust_additional)
597                 rdataset->ttl = ADB_CACHE_MINIMUM;
598         else
599                 rdataset->ttl = ttlclamp(rdataset->ttl);
600
601         if (rdtype == dns_rdatatype_a) {
602                 DP(NCACHE_LEVEL, "expire_v4 set to MIN(%u,%u) import_rdataset",
603                    adbname->expire_v4, now + rdataset->ttl);
604                 adbname->expire_v4 = ISC_MIN(adbname->expire_v4,
605                                              now + rdataset->ttl);
606         } else {
607                 DP(NCACHE_LEVEL, "expire_v6 set to MIN(%u,%u) import_rdataset",
608                    adbname->expire_v6, now + rdataset->ttl);
609                 adbname->expire_v6 = ISC_MIN(adbname->expire_v6,
610                                              now + rdataset->ttl);
611         }
612
613         if (new_addresses_added) {
614                 /*
615                  * Lie a little here.  This is more or less so code that cares
616                  * can find out if any new information was added or not.
617                  */
618                 return (ISC_R_SUCCESS);
619         }
620
621         return (result);
622 }
623
624 /*
625  * Requires the name's bucket be locked.
626  */
627 static isc_boolean_t
628 kill_name(dns_adbname_t **n, isc_eventtype_t ev) {
629         dns_adbname_t *name;
630         isc_boolean_t result = ISC_FALSE;
631         isc_boolean_t result4, result6;
632         int bucket;
633         dns_adb_t *adb;
634
635         INSIST(n != NULL);
636         name = *n;
637         *n = NULL;
638         INSIST(DNS_ADBNAME_VALID(name));
639         adb = name->adb;
640         INSIST(DNS_ADB_VALID(adb));
641
642         DP(DEF_LEVEL, "killing name %p", name);
643
644         /*
645          * If we're dead already, just check to see if we should go
646          * away now or not.
647          */
648         if (NAME_DEAD(name) && !NAME_FETCH(name)) {
649                 result = unlink_name(adb, name);
650                 free_adbname(adb, &name);
651                 if (result)
652                         result = dec_adb_irefcnt(adb);
653                 return (result);
654         }
655
656         /*
657          * Clean up the name's various lists.  These two are destructive
658          * in that they will always empty the list.
659          */
660         clean_finds_at_name(name, ev, DNS_ADBFIND_ADDRESSMASK);
661         result4 = clean_namehooks(adb, &name->v4);
662         result6 = clean_namehooks(adb, &name->v6);
663         clean_target(adb, &name->target);
664         result = ISC_TF(result4 || result6);
665
666         /*
667          * If fetches are running, cancel them.  If none are running, we can
668          * just kill the name here.
669          */
670         if (!NAME_FETCH(name)) {
671                 INSIST(result == ISC_FALSE);
672                 result = unlink_name(adb, name);
673                 free_adbname(adb, &name);
674                 if (result)
675                         result = dec_adb_irefcnt(adb);
676         } else {
677                 cancel_fetches_at_name(name);
678                 if (!NAME_DEAD(name)) {
679                         bucket = name->lock_bucket;
680                         ISC_LIST_UNLINK(adb->names[bucket], name, plink);
681                         ISC_LIST_APPEND(adb->deadnames[bucket], name, plink);
682                         name->flags |= NAME_IS_DEAD;
683                 }
684         }
685         return (result);
686 }
687
688 /*
689  * Requires the name's bucket be locked and no entry buckets be locked.
690  */
691 static isc_boolean_t
692 check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now) {
693         dns_adb_t *adb;
694         isc_boolean_t result4 = ISC_FALSE;
695         isc_boolean_t result6 = ISC_FALSE;
696
697         INSIST(DNS_ADBNAME_VALID(name));
698         adb = name->adb;
699         INSIST(DNS_ADB_VALID(adb));
700
701         /*
702          * Check to see if we need to remove the v4 addresses
703          */
704         if (!NAME_FETCH_V4(name) && EXPIRE_OK(name->expire_v4, now)) {
705                 if (NAME_HAS_V4(name)) {
706                         DP(DEF_LEVEL, "expiring v4 for name %p", name);
707                         result4 = clean_namehooks(adb, &name->v4);
708                         name->partial_result &= ~DNS_ADBFIND_INET;
709                 }
710                 name->expire_v4 = INT_MAX;
711                 name->fetch_err = FIND_ERR_UNEXPECTED;
712         }
713
714         /*
715          * Check to see if we need to remove the v6 addresses
716          */
717         if (!NAME_FETCH_V6(name) && EXPIRE_OK(name->expire_v6, now)) {
718                 if (NAME_HAS_V6(name)) {
719                         DP(DEF_LEVEL, "expiring v6 for name %p", name);
720                         result6 = clean_namehooks(adb, &name->v6);
721                         name->partial_result &= ~DNS_ADBFIND_INET6;
722                 }
723                 name->expire_v6 = INT_MAX;
724                 name->fetch6_err = FIND_ERR_UNEXPECTED;
725         }
726
727         /*
728          * Check to see if we need to remove the alias target.
729          */
730         if (EXPIRE_OK(name->expire_target, now)) {
731                 clean_target(adb, &name->target);
732                 name->expire_target = INT_MAX;
733         }
734         return (ISC_TF(result4 || result6));
735 }
736
737 /*
738  * Requires the name's bucket be locked.
739  */
740 static inline void
741 link_name(dns_adb_t *adb, int bucket, dns_adbname_t *name) {
742         INSIST(name->lock_bucket == DNS_ADB_INVALIDBUCKET);
743
744         ISC_LIST_PREPEND(adb->names[bucket], name, plink);
745         name->lock_bucket = bucket;
746         adb->name_refcnt[bucket]++;
747 }
748
749 /*
750  * Requires the name's bucket be locked.
751  */
752 static inline isc_boolean_t
753 unlink_name(dns_adb_t *adb, dns_adbname_t *name) {
754         int bucket;
755         isc_boolean_t result = ISC_FALSE;
756
757         bucket = name->lock_bucket;
758         INSIST(bucket != DNS_ADB_INVALIDBUCKET);
759
760         if (NAME_DEAD(name))
761                 ISC_LIST_UNLINK(adb->deadnames[bucket], name, plink);
762         else
763                 ISC_LIST_UNLINK(adb->names[bucket], name, plink);
764         name->lock_bucket = DNS_ADB_INVALIDBUCKET;
765         INSIST(adb->name_refcnt[bucket] > 0);
766         adb->name_refcnt[bucket]--;
767         if (adb->name_sd[bucket] && adb->name_refcnt[bucket] == 0)
768                 result = ISC_TRUE;
769         return (result);
770 }
771
772 /*
773  * Requires the entry's bucket be locked.
774  */
775 static inline void
776 link_entry(dns_adb_t *adb, int bucket, dns_adbentry_t *entry) {
777         int i;
778         dns_adbentry_t *e;
779
780         if (adb->overmem) {
781                 for (i = 0; i < 2; i++) {
782                         e = ISC_LIST_TAIL(adb->entries[bucket]);
783                         if (e == NULL)
784                                 break;
785                         if (e->refcnt == 0) {
786                                 unlink_entry(adb, e);
787                                 free_adbentry(adb, &e);
788                                 continue;
789                         }
790                         INSIST((e->flags & ENTRY_IS_DEAD) == 0);
791                         e->flags |= ENTRY_IS_DEAD;
792                         ISC_LIST_UNLINK(adb->entries[bucket], e, plink);
793                         ISC_LIST_PREPEND(adb->deadentries[bucket], e, plink);
794                 }
795         }
796
797         ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
798         entry->lock_bucket = bucket;
799         adb->entry_refcnt[bucket]++;
800 }
801
802 /*
803  * Requires the entry's bucket be locked.
804  */
805 static inline isc_boolean_t
806 unlink_entry(dns_adb_t *adb, dns_adbentry_t *entry) {
807         int bucket;
808         isc_boolean_t result = ISC_FALSE;
809
810         bucket = entry->lock_bucket;
811         INSIST(bucket != DNS_ADB_INVALIDBUCKET);
812
813         if ((entry->flags & ENTRY_IS_DEAD) != 0)
814                 ISC_LIST_UNLINK(adb->deadentries[bucket], entry, plink);
815         else
816                 ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
817         entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
818         INSIST(adb->entry_refcnt[bucket] > 0);
819         adb->entry_refcnt[bucket]--;
820         if (adb->entry_sd[bucket] && adb->entry_refcnt[bucket] == 0)
821                 result = ISC_TRUE;
822         return (result);
823 }
824
825 static inline void
826 violate_locking_hierarchy(isc_mutex_t *have, isc_mutex_t *want) {
827         if (isc_mutex_trylock(want) != ISC_R_SUCCESS) {
828                 UNLOCK(have);
829                 LOCK(want);
830                 LOCK(have);
831         }
832 }
833
834 /*
835  * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
836  * checked after calling this function.
837  */
838 static isc_boolean_t
839 shutdown_names(dns_adb_t *adb) {
840         int bucket;
841         isc_boolean_t result = ISC_FALSE;
842         dns_adbname_t *name;
843         dns_adbname_t *next_name;
844
845         for (bucket = 0; bucket < NBUCKETS; bucket++) {
846                 LOCK(&adb->namelocks[bucket]);
847                 adb->name_sd[bucket] = ISC_TRUE;
848
849                 name = ISC_LIST_HEAD(adb->names[bucket]);
850                 if (name == NULL) {
851                         /*
852                          * This bucket has no names.  We must decrement the
853                          * irefcnt ourselves, since it will not be
854                          * automatically triggered by a name being unlinked.
855                          */
856                         INSIST(result == ISC_FALSE);
857                         result = dec_adb_irefcnt(adb);
858                 } else {
859                         /*
860                          * Run through the list.  For each name, clean up finds
861                          * found there, and cancel any fetches running.  When
862                          * all the fetches are canceled, the name will destroy
863                          * itself.
864                          */
865                         while (name != NULL) {
866                                 next_name = ISC_LIST_NEXT(name, plink);
867                                 INSIST(result == ISC_FALSE);
868                                 result = kill_name(&name,
869                                                    DNS_EVENT_ADBSHUTDOWN);
870                                 name = next_name;
871                         }
872                 }
873
874                 UNLOCK(&adb->namelocks[bucket]);
875         }
876         return (result);
877 }
878
879 /*
880  * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
881  * checked after calling this function.
882  */
883 static isc_boolean_t
884 shutdown_entries(dns_adb_t *adb) {
885         int bucket;
886         isc_boolean_t result = ISC_FALSE;
887         dns_adbentry_t *entry;
888         dns_adbentry_t *next_entry;
889
890         for (bucket = 0; bucket < NBUCKETS; bucket++) {
891                 LOCK(&adb->entrylocks[bucket]);
892                 adb->entry_sd[bucket] = ISC_TRUE;
893
894                 entry = ISC_LIST_HEAD(adb->entries[bucket]);
895                 if (adb->entry_refcnt[bucket] == 0) {
896                         /*
897                          * This bucket has no entries.  We must decrement the
898                          * irefcnt ourselves, since it will not be
899                          * automatically triggered by an entry being unlinked.
900                          */
901                         result = dec_adb_irefcnt(adb);
902                 } else {
903                         /*
904                          * Run through the list.  Cleanup any entries not
905                          * associated with names, and which are not in use.
906                          */
907                         while (entry != NULL) {
908                                 next_entry = ISC_LIST_NEXT(entry, plink);
909                                 if (entry->refcnt == 0 &&
910                                     entry->expires != 0) {
911                                         result = unlink_entry(adb, entry);
912                                         free_adbentry(adb, &entry);
913                                         if (result)
914                                                 result = dec_adb_irefcnt(adb);
915                                 }
916                                 entry = next_entry;
917                         }
918                 }
919
920                 UNLOCK(&adb->entrylocks[bucket]);
921         }
922         return (result);
923 }
924
925 /*
926  * Name bucket must be locked
927  */
928 static void
929 cancel_fetches_at_name(dns_adbname_t *name) {
930         if (NAME_FETCH_A(name))
931             dns_resolver_cancelfetch(name->fetch_a->fetch);
932
933         if (NAME_FETCH_AAAA(name))
934             dns_resolver_cancelfetch(name->fetch_aaaa->fetch);
935 }
936
937 /*
938  * Assumes the name bucket is locked.
939  */
940 static isc_boolean_t
941 clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) {
942         dns_adbentry_t *entry;
943         dns_adbnamehook_t *namehook;
944         int addr_bucket;
945         isc_boolean_t result = ISC_FALSE;
946
947         addr_bucket = DNS_ADB_INVALIDBUCKET;
948         namehook = ISC_LIST_HEAD(*namehooks);
949         while (namehook != NULL) {
950                 INSIST(DNS_ADBNAMEHOOK_VALID(namehook));
951
952                 /*
953                  * Clean up the entry if needed.
954                  */
955                 entry = namehook->entry;
956                 if (entry != NULL) {
957                         INSIST(DNS_ADBENTRY_VALID(entry));
958
959                         if (addr_bucket != entry->lock_bucket) {
960                                 if (addr_bucket != DNS_ADB_INVALIDBUCKET)
961                                         UNLOCK(&adb->entrylocks[addr_bucket]);
962                                 addr_bucket = entry->lock_bucket;
963                                 LOCK(&adb->entrylocks[addr_bucket]);
964                         }
965
966                         result = dec_entry_refcnt(adb, entry, ISC_FALSE);
967                 }
968
969                 /*
970                  * Free the namehook
971                  */
972                 namehook->entry = NULL;
973                 ISC_LIST_UNLINK(*namehooks, namehook, plink);
974                 free_adbnamehook(adb, &namehook);
975
976                 namehook = ISC_LIST_HEAD(*namehooks);
977         }
978
979         if (addr_bucket != DNS_ADB_INVALIDBUCKET)
980                 UNLOCK(&adb->entrylocks[addr_bucket]);
981         return (result);
982 }
983
984 static void
985 clean_target(dns_adb_t *adb, dns_name_t *target) {
986         if (dns_name_countlabels(target) > 0) {
987                 dns_name_free(target, adb->mctx);
988                 dns_name_init(target, NULL);
989         }
990 }
991
992 static isc_result_t
993 set_target(dns_adb_t *adb, dns_name_t *name, dns_name_t *fname,
994            dns_rdataset_t *rdataset, dns_name_t *target)
995 {
996         isc_result_t result;
997         dns_namereln_t namereln;
998         unsigned int nlabels;
999         int order;
1000         dns_rdata_t rdata = DNS_RDATA_INIT;
1001         dns_fixedname_t fixed1, fixed2;
1002         dns_name_t *prefix, *new_target;
1003
1004         REQUIRE(dns_name_countlabels(target) == 0);
1005
1006         if (rdataset->type == dns_rdatatype_cname) {
1007                 dns_rdata_cname_t cname;
1008
1009                 /*
1010                  * Copy the CNAME's target into the target name.
1011                  */
1012                 result = dns_rdataset_first(rdataset);
1013                 if (result != ISC_R_SUCCESS)
1014                         return (result);
1015                 dns_rdataset_current(rdataset, &rdata);
1016                 result = dns_rdata_tostruct(&rdata, &cname, NULL);
1017                 if (result != ISC_R_SUCCESS)
1018                         return (result);
1019                 result = dns_name_dup(&cname.cname, adb->mctx, target);
1020                 dns_rdata_freestruct(&cname);
1021                 if (result != ISC_R_SUCCESS)
1022                         return (result);
1023         } else {
1024                 dns_rdata_dname_t dname;
1025
1026                 INSIST(rdataset->type == dns_rdatatype_dname);
1027                 namereln = dns_name_fullcompare(name, fname, &order, &nlabels);
1028                 INSIST(namereln == dns_namereln_subdomain);
1029                 /*
1030                  * Get the target name of the DNAME.
1031                  */
1032                 result = dns_rdataset_first(rdataset);
1033                 if (result != ISC_R_SUCCESS)
1034                         return (result);
1035                 dns_rdataset_current(rdataset, &rdata);
1036                 result = dns_rdata_tostruct(&rdata, &dname, NULL);
1037                 if (result != ISC_R_SUCCESS)
1038                         return (result);
1039                 /*
1040                  * Construct the new target name.
1041                  */
1042                 dns_fixedname_init(&fixed1);
1043                 prefix = dns_fixedname_name(&fixed1);
1044                 dns_fixedname_init(&fixed2);
1045                 new_target = dns_fixedname_name(&fixed2);
1046                 dns_name_split(name, nlabels, prefix, NULL);
1047                 result = dns_name_concatenate(prefix, &dname.dname, new_target,
1048                                               NULL);
1049                 dns_rdata_freestruct(&dname);
1050                 if (result != ISC_R_SUCCESS)
1051                         return (result);
1052                 result = dns_name_dup(new_target, adb->mctx, target);
1053                 if (result != ISC_R_SUCCESS)
1054                         return (result);
1055         }
1056
1057         return (ISC_R_SUCCESS);
1058 }
1059
1060 /*
1061  * Assumes nothing is locked, since this is called by the client.
1062  */
1063 static void
1064 event_free(isc_event_t *event) {
1065         dns_adbfind_t *find;
1066
1067         INSIST(event != NULL);
1068         find = event->ev_destroy_arg;
1069         INSIST(DNS_ADBFIND_VALID(find));
1070
1071         LOCK(&find->lock);
1072         find->flags |= FIND_EVENT_FREED;
1073         event->ev_destroy_arg = NULL;
1074         UNLOCK(&find->lock);
1075 }
1076
1077 /*
1078  * Assumes the name bucket is locked.
1079  */
1080 static void
1081 clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype,
1082                     unsigned int addrs)
1083 {
1084         isc_event_t *ev;
1085         isc_task_t *task;
1086         dns_adbfind_t *find;
1087         dns_adbfind_t *next_find;
1088         isc_boolean_t process;
1089         unsigned int wanted, notify;
1090
1091         DP(ENTER_LEVEL,
1092            "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x",
1093            name, evtype, addrs);
1094
1095         find = ISC_LIST_HEAD(name->finds);
1096         while (find != NULL) {
1097                 LOCK(&find->lock);
1098                 next_find = ISC_LIST_NEXT(find, plink);
1099
1100                 process = ISC_FALSE;
1101                 wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
1102                 notify = wanted & addrs;
1103
1104                 switch (evtype) {
1105                 case DNS_EVENT_ADBMOREADDRESSES:
1106                         DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES");
1107                         if ((notify) != 0) {
1108                                 find->flags &= ~addrs;
1109                                 process = ISC_TRUE;
1110                         }
1111                         break;
1112                 case DNS_EVENT_ADBNOMOREADDRESSES:
1113                         DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES");
1114                         find->flags &= ~addrs;
1115                         wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
1116                         if (wanted == 0)
1117                                 process = ISC_TRUE;
1118                         break;
1119                 default:
1120                         find->flags &= ~addrs;
1121                         process = ISC_TRUE;
1122                 }
1123
1124                 if (process) {
1125                         DP(DEF_LEVEL, "cfan: processing find %p", find);
1126                         /*
1127                          * Unlink the find from the name, letting the caller
1128                          * call dns_adb_destroyfind() on it to clean it up
1129                          * later.
1130                          */
1131                         ISC_LIST_UNLINK(name->finds, find, plink);
1132                         find->adbname = NULL;
1133                         find->name_bucket = DNS_ADB_INVALIDBUCKET;
1134
1135                         INSIST(!FIND_EVENTSENT(find));
1136
1137                         ev = &find->event;
1138                         task = ev->ev_sender;
1139                         ev->ev_sender = find;
1140                         find->result_v4 = find_err_map[name->fetch_err];
1141                         find->result_v6 = find_err_map[name->fetch6_err];
1142                         ev->ev_type = evtype;
1143                         ev->ev_destroy = event_free;
1144                         ev->ev_destroy_arg = find;
1145
1146                         DP(DEF_LEVEL,
1147                            "sending event %p to task %p for find %p",
1148                            ev, task, find);
1149
1150                         isc_task_sendanddetach(&task, (isc_event_t **)&ev);
1151                 } else {
1152                         DP(DEF_LEVEL, "cfan: skipping find %p", find);
1153                 }
1154
1155                 UNLOCK(&find->lock);
1156                 find = next_find;
1157         }
1158
1159         DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name);
1160 }
1161
1162 static inline void
1163 check_exit(dns_adb_t *adb) {
1164         isc_event_t *event;
1165         /*
1166          * The caller must be holding the adb lock.
1167          */
1168         if (adb->shutting_down) {
1169                 /*
1170                  * If there aren't any external references either, we're
1171                  * done.  Send the control event to initiate shutdown.
1172                  */
1173                 INSIST(!adb->cevent_sent);      /* Sanity check. */
1174                 event = &adb->cevent;
1175                 isc_task_send(adb->task, &event);
1176                 adb->cevent_sent = ISC_TRUE;
1177         }
1178 }
1179
1180 static inline isc_boolean_t
1181 dec_adb_irefcnt(dns_adb_t *adb) {
1182         isc_event_t *event;
1183         isc_task_t *etask;
1184         isc_boolean_t result = ISC_FALSE;
1185
1186         LOCK(&adb->reflock);
1187
1188         INSIST(adb->irefcnt > 0);
1189         adb->irefcnt--;
1190
1191         if (adb->irefcnt == 0) {
1192                 event = ISC_LIST_HEAD(adb->whenshutdown);
1193                 while (event != NULL) {
1194                         ISC_LIST_UNLINK(adb->whenshutdown, event, ev_link);
1195                         etask = event->ev_sender;
1196                         event->ev_sender = adb;
1197                         isc_task_sendanddetach(&etask, &event);
1198                         event = ISC_LIST_HEAD(adb->whenshutdown);
1199                 }
1200         }
1201
1202         if (adb->irefcnt == 0 && adb->erefcnt == 0)
1203                 result = ISC_TRUE;
1204         UNLOCK(&adb->reflock);
1205         return (result);
1206 }
1207
1208 static inline void
1209 inc_adb_irefcnt(dns_adb_t *adb) {
1210         LOCK(&adb->reflock);
1211         adb->irefcnt++;
1212         UNLOCK(&adb->reflock);
1213 }
1214
1215 static inline void
1216 inc_adb_erefcnt(dns_adb_t *adb) {
1217         LOCK(&adb->reflock);
1218         adb->erefcnt++;
1219         UNLOCK(&adb->reflock);
1220 }
1221
1222 static inline void
1223 inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
1224         int bucket;
1225
1226         bucket = entry->lock_bucket;
1227
1228         if (lock)
1229                 LOCK(&adb->entrylocks[bucket]);
1230
1231         entry->refcnt++;
1232
1233         if (lock)
1234                 UNLOCK(&adb->entrylocks[bucket]);
1235 }
1236
1237 static inline isc_boolean_t
1238 dec_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
1239         int bucket;
1240         isc_boolean_t destroy_entry;
1241         isc_boolean_t result = ISC_FALSE;
1242
1243         bucket = entry->lock_bucket;
1244
1245         if (lock)
1246                 LOCK(&adb->entrylocks[bucket]);
1247
1248         INSIST(entry->refcnt > 0);
1249         entry->refcnt--;
1250
1251         destroy_entry = ISC_FALSE;
1252         if (entry->refcnt == 0 &&
1253             (adb->entry_sd[bucket] || entry->expires == 0 || adb->overmem ||
1254              (entry->flags & ENTRY_IS_DEAD) != 0)) {
1255                 destroy_entry = ISC_TRUE;
1256                 result = unlink_entry(adb, entry);
1257         }
1258
1259         if (lock)
1260                 UNLOCK(&adb->entrylocks[bucket]);
1261
1262         if (!destroy_entry)
1263                 return (result);
1264
1265         entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
1266
1267         free_adbentry(adb, &entry);
1268         if (result)
1269                 result = dec_adb_irefcnt(adb);
1270
1271         return (result);
1272 }
1273
1274 static inline dns_adbname_t *
1275 new_adbname(dns_adb_t *adb, dns_name_t *dnsname) {
1276         dns_adbname_t *name;
1277
1278         name = isc_mempool_get(adb->nmp);
1279         if (name == NULL)
1280                 return (NULL);
1281
1282         dns_name_init(&name->name, NULL);
1283         if (dns_name_dup(dnsname, adb->mctx, &name->name) != ISC_R_SUCCESS) {
1284                 isc_mempool_put(adb->nmp, name);
1285                 return (NULL);
1286         }
1287         dns_name_init(&name->target, NULL);
1288         name->magic = DNS_ADBNAME_MAGIC;
1289         name->adb = adb;
1290         name->partial_result = 0;
1291         name->flags = 0;
1292         name->expire_v4 = INT_MAX;
1293         name->expire_v6 = INT_MAX;
1294         name->expire_target = INT_MAX;
1295         name->chains = 0;
1296         name->lock_bucket = DNS_ADB_INVALIDBUCKET;
1297         ISC_LIST_INIT(name->v4);
1298         ISC_LIST_INIT(name->v6);
1299         name->fetch_a = NULL;
1300         name->fetch_aaaa = NULL;
1301         name->fetch_err = FIND_ERR_UNEXPECTED;
1302         name->fetch6_err = FIND_ERR_UNEXPECTED;
1303         ISC_LIST_INIT(name->finds);
1304         ISC_LINK_INIT(name, plink);
1305
1306         return (name);
1307 }
1308
1309 static inline void
1310 free_adbname(dns_adb_t *adb, dns_adbname_t **name) {
1311         dns_adbname_t *n;
1312
1313         INSIST(name != NULL && DNS_ADBNAME_VALID(*name));
1314         n = *name;
1315         *name = NULL;
1316
1317         INSIST(!NAME_HAS_V4(n));
1318         INSIST(!NAME_HAS_V6(n));
1319         INSIST(!NAME_FETCH(n));
1320         INSIST(ISC_LIST_EMPTY(n->finds));
1321         INSIST(!ISC_LINK_LINKED(n, plink));
1322         INSIST(n->lock_bucket == DNS_ADB_INVALIDBUCKET);
1323         INSIST(n->adb == adb);
1324
1325         n->magic = 0;
1326         dns_name_free(&n->name, adb->mctx);
1327
1328         isc_mempool_put(adb->nmp, n);
1329 }
1330
1331 static inline dns_adbnamehook_t *
1332 new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) {
1333         dns_adbnamehook_t *nh;
1334
1335         nh = isc_mempool_get(adb->nhmp);
1336         if (nh == NULL)
1337                 return (NULL);
1338
1339         nh->magic = DNS_ADBNAMEHOOK_MAGIC;
1340         nh->entry = entry;
1341         ISC_LINK_INIT(nh, plink);
1342
1343         return (nh);
1344 }
1345
1346 static inline void
1347 free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) {
1348         dns_adbnamehook_t *nh;
1349
1350         INSIST(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook));
1351         nh = *namehook;
1352         *namehook = NULL;
1353
1354         INSIST(nh->entry == NULL);
1355         INSIST(!ISC_LINK_LINKED(nh, plink));
1356
1357         nh->magic = 0;
1358         isc_mempool_put(adb->nhmp, nh);
1359 }
1360
1361 static inline dns_adblameinfo_t *
1362 new_adblameinfo(dns_adb_t *adb, dns_name_t *qname, dns_rdatatype_t qtype) {
1363         dns_adblameinfo_t *li;
1364
1365         li = isc_mempool_get(adb->limp);
1366         if (li == NULL)
1367                 return (NULL);
1368
1369         dns_name_init(&li->qname, NULL);
1370         if (dns_name_dup(qname, adb->mctx, &li->qname) != ISC_R_SUCCESS) {
1371                 isc_mempool_put(adb->limp, li);
1372                 return (NULL);
1373         }
1374         li->magic = DNS_ADBLAMEINFO_MAGIC;
1375         li->lame_timer = 0;
1376         li->qtype = qtype;
1377         ISC_LINK_INIT(li, plink);
1378
1379         return (li);
1380 }
1381
1382 static inline void
1383 free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) {
1384         dns_adblameinfo_t *li;
1385
1386         INSIST(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo));
1387         li = *lameinfo;
1388         *lameinfo = NULL;
1389
1390         INSIST(!ISC_LINK_LINKED(li, plink));
1391
1392         dns_name_free(&li->qname, adb->mctx);
1393
1394         li->magic = 0;
1395
1396         isc_mempool_put(adb->limp, li);
1397 }
1398
1399 static inline dns_adbentry_t *
1400 new_adbentry(dns_adb_t *adb) {
1401         dns_adbentry_t *e;
1402         isc_uint32_t r;
1403
1404         e = isc_mempool_get(adb->emp);
1405         if (e == NULL)
1406                 return (NULL);
1407
1408         e->magic = DNS_ADBENTRY_MAGIC;
1409         e->lock_bucket = DNS_ADB_INVALIDBUCKET;
1410         e->refcnt = 0;
1411         e->flags = 0;
1412         isc_random_get(&r);
1413         e->srtt = (r & 0x1f) + 1;
1414         e->expires = 0;
1415         ISC_LIST_INIT(e->lameinfo);
1416         ISC_LINK_INIT(e, plink);
1417
1418         return (e);
1419 }
1420
1421 static inline void
1422 free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) {
1423         dns_adbentry_t *e;
1424         dns_adblameinfo_t *li;
1425
1426         INSIST(entry != NULL && DNS_ADBENTRY_VALID(*entry));
1427         e = *entry;
1428         *entry = NULL;
1429
1430         INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET);
1431         INSIST(e->refcnt == 0);
1432         INSIST(!ISC_LINK_LINKED(e, plink));
1433
1434         e->magic = 0;
1435
1436         li = ISC_LIST_HEAD(e->lameinfo);
1437         while (li != NULL) {
1438                 ISC_LIST_UNLINK(e->lameinfo, li, plink);
1439                 free_adblameinfo(adb, &li);
1440                 li = ISC_LIST_HEAD(e->lameinfo);
1441         }
1442
1443         isc_mempool_put(adb->emp, e);
1444 }
1445
1446 static inline dns_adbfind_t *
1447 new_adbfind(dns_adb_t *adb) {
1448         dns_adbfind_t *h;
1449         isc_result_t result;
1450
1451         h = isc_mempool_get(adb->ahmp);
1452         if (h == NULL)
1453                 return (NULL);
1454
1455         /*
1456          * Public members.
1457          */
1458         h->magic = 0;
1459         h->adb = adb;
1460         h->partial_result = 0;
1461         h->options = 0;
1462         h->flags = 0;
1463         h->result_v4 = ISC_R_UNEXPECTED;
1464         h->result_v6 = ISC_R_UNEXPECTED;
1465         ISC_LINK_INIT(h, publink);
1466         ISC_LINK_INIT(h, plink);
1467         ISC_LIST_INIT(h->list);
1468         h->adbname = NULL;
1469         h->name_bucket = DNS_ADB_INVALIDBUCKET;
1470
1471         /*
1472          * private members
1473          */
1474         result = isc_mutex_init(&h->lock);
1475         if (result != ISC_R_SUCCESS) {
1476                 isc_mempool_put(adb->ahmp, h);
1477                 return (NULL);
1478         }
1479
1480         ISC_EVENT_INIT(&h->event, sizeof(isc_event_t), 0, 0, 0, NULL, NULL,
1481                        NULL, NULL, h);
1482
1483         inc_adb_irefcnt(adb);
1484         h->magic = DNS_ADBFIND_MAGIC;
1485         return (h);
1486 }
1487
1488 static inline dns_adbfetch_t *
1489 new_adbfetch(dns_adb_t *adb) {
1490         dns_adbfetch_t *f;
1491
1492         f = isc_mempool_get(adb->afmp);
1493         if (f == NULL)
1494                 return (NULL);
1495
1496         f->magic = 0;
1497         f->fetch = NULL;
1498
1499         dns_rdataset_init(&f->rdataset);
1500
1501         f->magic = DNS_ADBFETCH_MAGIC;
1502
1503         return (f);
1504 }
1505
1506 static inline void
1507 free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetch) {
1508         dns_adbfetch_t *f;
1509
1510         INSIST(fetch != NULL && DNS_ADBFETCH_VALID(*fetch));
1511         f = *fetch;
1512         *fetch = NULL;
1513
1514         f->magic = 0;
1515
1516         if (dns_rdataset_isassociated(&f->rdataset))
1517                 dns_rdataset_disassociate(&f->rdataset);
1518
1519         isc_mempool_put(adb->afmp, f);
1520 }
1521
1522 static inline isc_boolean_t
1523 free_adbfind(dns_adb_t *adb, dns_adbfind_t **findp) {
1524         dns_adbfind_t *find;
1525
1526         INSIST(findp != NULL && DNS_ADBFIND_VALID(*findp));
1527         find = *findp;
1528         *findp = NULL;
1529
1530         INSIST(!FIND_HAS_ADDRS(find));
1531         INSIST(!ISC_LINK_LINKED(find, publink));
1532         INSIST(!ISC_LINK_LINKED(find, plink));
1533         INSIST(find->name_bucket == DNS_ADB_INVALIDBUCKET);
1534         INSIST(find->adbname == NULL);
1535
1536         find->magic = 0;
1537
1538         DESTROYLOCK(&find->lock);
1539         isc_mempool_put(adb->ahmp, find);
1540         return (dec_adb_irefcnt(adb));
1541 }
1542
1543 /*
1544  * Copy bits from the entry into the newly allocated addrinfo.  The entry
1545  * must be locked, and the reference count must be bumped up by one
1546  * if this function returns a valid pointer.
1547  */
1548 static inline dns_adbaddrinfo_t *
1549 new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) {
1550         dns_adbaddrinfo_t *ai;
1551
1552         ai = isc_mempool_get(adb->aimp);
1553         if (ai == NULL)
1554                 return (NULL);
1555
1556         ai->magic = DNS_ADBADDRINFO_MAGIC;
1557         ai->sockaddr = entry->sockaddr;
1558         isc_sockaddr_setport(&ai->sockaddr, port);
1559         ai->srtt = entry->srtt;
1560         ai->flags = entry->flags;
1561         ai->entry = entry;
1562         ISC_LINK_INIT(ai, publink);
1563
1564         return (ai);
1565 }
1566
1567 static inline void
1568 free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) {
1569         dns_adbaddrinfo_t *ai;
1570
1571         INSIST(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo));
1572         ai = *ainfo;
1573         *ainfo = NULL;
1574
1575         INSIST(ai->entry == NULL);
1576         INSIST(!ISC_LINK_LINKED(ai, publink));
1577
1578         ai->magic = 0;
1579
1580         isc_mempool_put(adb->aimp, ai);
1581 }
1582
1583 /*
1584  * Search for the name.  NOTE:  The bucket is kept locked on both
1585  * success and failure, so it must always be unlocked by the caller!
1586  *
1587  * On the first call to this function, *bucketp must be set to
1588  * DNS_ADB_INVALIDBUCKET.
1589  */
1590 static inline dns_adbname_t *
1591 find_name_and_lock(dns_adb_t *adb, dns_name_t *name,
1592                    unsigned int options, int *bucketp)
1593 {
1594         dns_adbname_t *adbname;
1595         int bucket;
1596
1597         bucket = dns_name_fullhash(name, ISC_FALSE) % NBUCKETS;
1598
1599         if (*bucketp == DNS_ADB_INVALIDBUCKET) {
1600                 LOCK(&adb->namelocks[bucket]);
1601                 *bucketp = bucket;
1602         } else if (*bucketp != bucket) {
1603                 UNLOCK(&adb->namelocks[*bucketp]);
1604                 LOCK(&adb->namelocks[bucket]);
1605                 *bucketp = bucket;
1606         }
1607
1608         adbname = ISC_LIST_HEAD(adb->names[bucket]);
1609         while (adbname != NULL) {
1610                 if (!NAME_DEAD(adbname)) {
1611                         if (dns_name_equal(name, &adbname->name)
1612                             && GLUEHINT_OK(adbname, options)
1613                             && STARTATZONE_MATCHES(adbname, options))
1614                                 return (adbname);
1615                 }
1616                 adbname = ISC_LIST_NEXT(adbname, plink);
1617         }
1618
1619         return (NULL);
1620 }
1621
1622 /*
1623  * Search for the address.  NOTE:  The bucket is kept locked on both
1624  * success and failure, so it must always be unlocked by the caller.
1625  *
1626  * On the first call to this function, *bucketp must be set to
1627  * DNS_ADB_INVALIDBUCKET.  This will cause a lock to occur.  On
1628  * later calls (within the same "lock path") it can be left alone, so
1629  * if this function is called multiple times locking is only done if
1630  * the bucket changes.
1631  */
1632 static inline dns_adbentry_t *
1633 find_entry_and_lock(dns_adb_t *adb, isc_sockaddr_t *addr, int *bucketp,
1634         isc_stdtime_t now)
1635 {
1636         dns_adbentry_t *entry, *entry_next;
1637         int bucket;
1638
1639         bucket = isc_sockaddr_hash(addr, ISC_TRUE) % NBUCKETS;
1640
1641         if (*bucketp == DNS_ADB_INVALIDBUCKET) {
1642                 LOCK(&adb->entrylocks[bucket]);
1643                 *bucketp = bucket;
1644         } else if (*bucketp != bucket) {
1645                 UNLOCK(&adb->entrylocks[*bucketp]);
1646                 LOCK(&adb->entrylocks[bucket]);
1647                 *bucketp = bucket;
1648         }
1649
1650         /* Search the list, while cleaning up expired entries. */
1651         for (entry = ISC_LIST_HEAD(adb->entries[bucket]);
1652              entry != NULL;
1653              entry = entry_next) {
1654                 entry_next = ISC_LIST_NEXT(entry, plink);
1655                 (void)check_expire_entry(adb, &entry, now);
1656                 if (entry != NULL &&
1657                     isc_sockaddr_equal(addr, &entry->sockaddr)) {
1658                         ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
1659                         ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
1660                         return (entry);
1661                 }
1662         }
1663
1664         return (NULL);
1665 }
1666
1667 /*
1668  * Entry bucket MUST be locked!
1669  */
1670 static isc_boolean_t
1671 entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, dns_name_t *qname,
1672               dns_rdatatype_t qtype, isc_stdtime_t now)
1673 {
1674         dns_adblameinfo_t *li, *next_li;
1675         isc_boolean_t is_bad;
1676
1677         is_bad = ISC_FALSE;
1678
1679         li = ISC_LIST_HEAD(entry->lameinfo);
1680         if (li == NULL)
1681                 return (ISC_FALSE);
1682         while (li != NULL) {
1683                 next_li = ISC_LIST_NEXT(li, plink);
1684
1685                 /*
1686                  * Has the entry expired?
1687                  */
1688                 if (li->lame_timer < now) {
1689                         ISC_LIST_UNLINK(entry->lameinfo, li, plink);
1690                         free_adblameinfo(adb, &li);
1691                 }
1692
1693                 /*
1694                  * Order tests from least to most expensive.
1695                  *
1696                  * We do not break out of the main loop here as
1697                  * we use the loop for house keeping.
1698                  */
1699                 if (li != NULL && !is_bad && li->qtype == qtype &&
1700                     dns_name_equal(qname, &li->qname))
1701                         is_bad = ISC_TRUE;
1702
1703                 li = next_li;
1704         }
1705
1706         return (is_bad);
1707 }
1708
1709 static void
1710 copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, dns_name_t *qname,
1711                     dns_rdatatype_t qtype, dns_adbname_t *name,
1712                     isc_stdtime_t now)
1713 {
1714         dns_adbnamehook_t *namehook;
1715         dns_adbaddrinfo_t *addrinfo;
1716         dns_adbentry_t *entry;
1717         int bucket;
1718
1719         bucket = DNS_ADB_INVALIDBUCKET;
1720
1721         if (find->options & DNS_ADBFIND_INET) {
1722                 namehook = ISC_LIST_HEAD(name->v4);
1723                 while (namehook != NULL) {
1724                         entry = namehook->entry;
1725                         bucket = entry->lock_bucket;
1726                         LOCK(&adb->entrylocks[bucket]);
1727
1728                         if (!FIND_RETURNLAME(find)
1729                             && entry_is_lame(adb, entry, qname, qtype, now)) {
1730                                 find->options |= DNS_ADBFIND_LAMEPRUNED;
1731                                 goto nextv4;
1732                         }
1733                         addrinfo = new_adbaddrinfo(adb, entry, find->port);
1734                         if (addrinfo == NULL) {
1735                                 find->partial_result |= DNS_ADBFIND_INET;
1736                                 goto out;
1737                         }
1738                         /*
1739                          * Found a valid entry.  Add it to the find's list.
1740                          */
1741                         inc_entry_refcnt(adb, entry, ISC_FALSE);
1742                         ISC_LIST_APPEND(find->list, addrinfo, publink);
1743                         addrinfo = NULL;
1744                 nextv4:
1745                         UNLOCK(&adb->entrylocks[bucket]);
1746                         bucket = DNS_ADB_INVALIDBUCKET;
1747                         namehook = ISC_LIST_NEXT(namehook, plink);
1748                 }
1749         }
1750
1751         if (find->options & DNS_ADBFIND_INET6) {
1752                 namehook = ISC_LIST_HEAD(name->v6);
1753                 while (namehook != NULL) {
1754                         entry = namehook->entry;
1755                         bucket = entry->lock_bucket;
1756                         LOCK(&adb->entrylocks[bucket]);
1757
1758                         if (!FIND_RETURNLAME(find)
1759                             && entry_is_lame(adb, entry, qname, qtype, now)) {
1760                                 find->options |= DNS_ADBFIND_LAMEPRUNED;
1761                                 goto nextv6;
1762                         }
1763                         addrinfo = new_adbaddrinfo(adb, entry, find->port);
1764                         if (addrinfo == NULL) {
1765                                 find->partial_result |= DNS_ADBFIND_INET6;
1766                                 goto out;
1767                         }
1768                         /*
1769                          * Found a valid entry.  Add it to the find's list.
1770                          */
1771                         inc_entry_refcnt(adb, entry, ISC_FALSE);
1772                         ISC_LIST_APPEND(find->list, addrinfo, publink);
1773                         addrinfo = NULL;
1774                 nextv6:
1775                         UNLOCK(&adb->entrylocks[bucket]);
1776                         bucket = DNS_ADB_INVALIDBUCKET;
1777                         namehook = ISC_LIST_NEXT(namehook, plink);
1778                 }
1779         }
1780
1781  out:
1782         if (bucket != DNS_ADB_INVALIDBUCKET)
1783                 UNLOCK(&adb->entrylocks[bucket]);
1784 }
1785
1786 static void
1787 shutdown_task(isc_task_t *task, isc_event_t *ev) {
1788         dns_adb_t *adb;
1789
1790         UNUSED(task);
1791
1792         adb = ev->ev_arg;
1793         INSIST(DNS_ADB_VALID(adb));
1794
1795         isc_event_free(&ev);
1796         /*
1797          * Wait for lock around check_exit() call to be released.
1798          */
1799         LOCK(&adb->lock);
1800         UNLOCK(&adb->lock);
1801         destroy(adb);
1802 }
1803
1804 /*
1805  * Name bucket must be locked; adb may be locked; no other locks held.
1806  */
1807 static isc_boolean_t
1808 check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) {
1809         dns_adbname_t *name;
1810         isc_boolean_t result = ISC_FALSE;
1811
1812         INSIST(namep != NULL && DNS_ADBNAME_VALID(*namep));
1813         name = *namep;
1814
1815         if (NAME_HAS_V4(name) || NAME_HAS_V6(name))
1816                 return (result);
1817         if (NAME_FETCH(name))
1818                 return (result);
1819         if (!EXPIRE_OK(name->expire_v4, now))
1820                 return (result);
1821         if (!EXPIRE_OK(name->expire_v6, now))
1822                 return (result);
1823         if (!EXPIRE_OK(name->expire_target, now))
1824                 return (result);
1825
1826         /*
1827          * The name is empty.  Delete it.
1828          */
1829         result = kill_name(&name, DNS_EVENT_ADBEXPIRED);
1830         *namep = NULL;
1831
1832         /*
1833          * Our caller, or one of its callers, will be calling check_exit() at
1834          * some point, so we don't need to do it here.
1835          */
1836         return (result);
1837 }
1838
1839 /*%
1840  * Examine the tail entry of the LRU list to see if it expires or is stale
1841  * (unused for some period); if so, the name entry will be freed.  If the ADB
1842  * is in the overmem condition, the tail and the next to tail entries
1843  * will be unconditionally removed (unless they have an outstanding fetch).
1844  * We don't care about a race on 'overmem' at the risk of causing some
1845  * collateral damage or a small delay in starting cleanup, so we don't bother
1846  * to lock ADB (if it's not locked).
1847  *
1848  * Name bucket must be locked; adb may be locked; no other locks held.
1849  */
1850 static void
1851 check_stale_name(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
1852         int victims, max_victims;
1853         isc_boolean_t result;
1854         dns_adbname_t *victim, *next_victim;
1855         isc_boolean_t overmem = adb->overmem;
1856         int scans = 0;
1857
1858         INSIST(bucket != DNS_ADB_INVALIDBUCKET);
1859
1860         max_victims = overmem ? 2 : 1;
1861
1862         /*
1863          * We limit the number of scanned entries to 10 (arbitrary choice)
1864          * in order to avoid examining too many entries when there are many
1865          * tail entries that have fetches (this should be rare, but could
1866          * happen).
1867          */
1868         victim = ISC_LIST_TAIL(adb->names[bucket]);
1869         for (victims = 0;
1870              victim != NULL && victims < max_victims && scans < 10;
1871              victim = next_victim) {
1872                 INSIST(!NAME_DEAD(victim));
1873                 scans++;
1874                 next_victim = ISC_LIST_PREV(victim, plink);
1875                 result = check_expire_name(&victim, now);
1876                 if (victim == NULL) {
1877                         victims++;
1878                         goto next;
1879                 }
1880
1881                 if (!NAME_FETCH(victim) &&
1882                     (overmem || victim->last_used + ADB_STALE_MARGIN <= now)) {
1883                         RUNTIME_CHECK(kill_name(&victim,
1884                                                 DNS_EVENT_ADBCANCELED) ==
1885                                       ISC_FALSE);
1886                         victims++;
1887                 }
1888
1889         next:
1890                 if (!overmem)
1891                         break;
1892         }
1893 }
1894
1895 /*
1896  * Entry bucket must be locked; adb may be locked; no other locks held.
1897  */
1898 static isc_boolean_t
1899 check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now)
1900 {
1901         dns_adbentry_t *entry;
1902         isc_boolean_t result = ISC_FALSE;
1903
1904         INSIST(entryp != NULL && DNS_ADBENTRY_VALID(*entryp));
1905         entry = *entryp;
1906
1907         if (entry->refcnt != 0)
1908                 return (result);
1909
1910         if (entry->expires == 0 || entry->expires > now)
1911                 return (result);
1912
1913         /*
1914          * The entry is not in use.  Delete it.
1915          */
1916         DP(DEF_LEVEL, "killing entry %p", entry);
1917         INSIST(ISC_LINK_LINKED(entry, plink));
1918         result = unlink_entry(adb, entry);
1919         free_adbentry(adb, &entry);
1920         if (result)
1921                 dec_adb_irefcnt(adb);
1922         *entryp = NULL;
1923         return (result);
1924 }
1925
1926 /*
1927  * ADB must be locked, and no other locks held.
1928  */
1929 static isc_boolean_t
1930 cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
1931         dns_adbname_t *name;
1932         dns_adbname_t *next_name;
1933         isc_boolean_t result = ISC_FALSE;
1934
1935         DP(CLEAN_LEVEL, "cleaning name bucket %d", bucket);
1936
1937         LOCK(&adb->namelocks[bucket]);
1938         if (adb->name_sd[bucket]) {
1939                 UNLOCK(&adb->namelocks[bucket]);
1940                 return (result);
1941         }
1942
1943         name = ISC_LIST_HEAD(adb->names[bucket]);
1944         while (name != NULL) {
1945                 next_name = ISC_LIST_NEXT(name, plink);
1946                 INSIST(result == ISC_FALSE);
1947                 result = check_expire_namehooks(name, now);
1948                 if (!result)
1949                         result = check_expire_name(&name, now);
1950                 name = next_name;
1951         }
1952         UNLOCK(&adb->namelocks[bucket]);
1953         return (result);
1954 }
1955
1956 /*
1957  * ADB must be locked, and no other locks held.
1958  */
1959 static isc_boolean_t
1960 cleanup_entries(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
1961         dns_adbentry_t *entry, *next_entry;
1962         isc_boolean_t result = ISC_FALSE;
1963
1964         DP(CLEAN_LEVEL, "cleaning entry bucket %d", bucket);
1965
1966         LOCK(&adb->entrylocks[bucket]);
1967         entry = ISC_LIST_HEAD(adb->entries[bucket]);
1968         while (entry != NULL) {
1969                 next_entry = ISC_LIST_NEXT(entry, plink);
1970                 INSIST(result == ISC_FALSE);
1971                 result = check_expire_entry(adb, &entry, now);
1972                 entry = next_entry;
1973         }
1974         UNLOCK(&adb->entrylocks[bucket]);
1975         return (result);
1976 }
1977
1978 static void
1979 destroy(dns_adb_t *adb) {
1980         adb->magic = 0;
1981
1982         isc_task_detach(&adb->task);
1983
1984         isc_mempool_destroy(&adb->nmp);
1985         isc_mempool_destroy(&adb->nhmp);
1986         isc_mempool_destroy(&adb->limp);
1987         isc_mempool_destroy(&adb->emp);
1988         isc_mempool_destroy(&adb->ahmp);
1989         isc_mempool_destroy(&adb->aimp);
1990         isc_mempool_destroy(&adb->afmp);
1991
1992         DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS);
1993         DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS);
1994
1995         DESTROYLOCK(&adb->reflock);
1996         DESTROYLOCK(&adb->lock);
1997         DESTROYLOCK(&adb->mplock);
1998         DESTROYLOCK(&adb->overmemlock);
1999
2000         isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
2001 }
2002
2003
2004 /*
2005  * Public functions.
2006  */
2007
2008 isc_result_t
2009 dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_timermgr_t *timermgr,
2010                isc_taskmgr_t *taskmgr, dns_adb_t **newadb)
2011 {
2012         dns_adb_t *adb;
2013         isc_result_t result;
2014         int i;
2015
2016         REQUIRE(mem != NULL);
2017         REQUIRE(view != NULL);
2018         REQUIRE(timermgr != NULL); /* this is actually unused */
2019         REQUIRE(taskmgr != NULL);
2020         REQUIRE(newadb != NULL && *newadb == NULL);
2021
2022         UNUSED(timermgr);
2023
2024         adb = isc_mem_get(mem, sizeof(dns_adb_t));
2025         if (adb == NULL)
2026                 return (ISC_R_NOMEMORY);
2027
2028         /*
2029          * Initialize things here that cannot fail, and especially things
2030          * that must be NULL for the error return to work properly.
2031          */
2032         adb->magic = 0;
2033         adb->erefcnt = 1;
2034         adb->irefcnt = 0;
2035         adb->nmp = NULL;
2036         adb->nhmp = NULL;
2037         adb->limp = NULL;
2038         adb->emp = NULL;
2039         adb->ahmp = NULL;
2040         adb->aimp = NULL;
2041         adb->afmp = NULL;
2042         adb->task = NULL;
2043         adb->mctx = NULL;
2044         adb->view = view;
2045         adb->taskmgr = taskmgr;
2046         adb->next_cleanbucket = 0;
2047         ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL,
2048                        DNS_EVENT_ADBCONTROL, shutdown_task, adb,
2049                        adb, NULL, NULL);
2050         adb->cevent_sent = ISC_FALSE;
2051         adb->shutting_down = ISC_FALSE;
2052         adb->overmem = ISC_FALSE;
2053         ISC_LIST_INIT(adb->whenshutdown);
2054
2055         isc_mem_attach(mem, &adb->mctx);
2056
2057         result = isc_mutex_init(&adb->lock);
2058         if (result != ISC_R_SUCCESS)
2059                 goto fail0b;
2060
2061         result = isc_mutex_init(&adb->mplock);
2062         if (result != ISC_R_SUCCESS)
2063                 goto fail0c;
2064
2065         result = isc_mutex_init(&adb->reflock);
2066         if (result != ISC_R_SUCCESS)
2067                 goto fail0d;
2068
2069         result = isc_mutex_init(&adb->overmemlock);
2070         if (result != ISC_R_SUCCESS)
2071                 goto fail0e;
2072
2073         /*
2074          * Initialize the bucket locks for names and elements.
2075          * May as well initialize the list heads, too.
2076          */
2077         result = isc_mutexblock_init(adb->namelocks, NBUCKETS);
2078         if (result != ISC_R_SUCCESS)
2079                 goto fail1;
2080         for (i = 0; i < NBUCKETS; i++) {
2081                 ISC_LIST_INIT(adb->names[i]);
2082                 ISC_LIST_INIT(adb->deadnames[i]);
2083                 adb->name_sd[i] = ISC_FALSE;
2084                 adb->name_refcnt[i] = 0;
2085                 adb->irefcnt++;
2086         }
2087         for (i = 0; i < NBUCKETS; i++) {
2088                 ISC_LIST_INIT(adb->entries[i]);
2089                 ISC_LIST_INIT(adb->deadentries[i]);
2090                 adb->entry_sd[i] = ISC_FALSE;
2091                 adb->entry_refcnt[i] = 0;
2092                 adb->irefcnt++;
2093         }
2094         result = isc_mutexblock_init(adb->entrylocks, NBUCKETS);
2095         if (result != ISC_R_SUCCESS)
2096                 goto fail2;
2097
2098         /*
2099          * Memory pools
2100          */
2101 #define MPINIT(t, p, n) do { \
2102         result = isc_mempool_create(mem, sizeof(t), &(p)); \
2103         if (result != ISC_R_SUCCESS) \
2104                 goto fail3; \
2105         isc_mempool_setfreemax((p), FREE_ITEMS); \
2106         isc_mempool_setfillcount((p), FILL_COUNT); \
2107         isc_mempool_setname((p), n); \
2108         isc_mempool_associatelock((p), &adb->mplock); \
2109 } while (0)
2110
2111         MPINIT(dns_adbname_t, adb->nmp, "adbname");
2112         MPINIT(dns_adbnamehook_t, adb->nhmp, "adbnamehook");
2113         MPINIT(dns_adblameinfo_t, adb->limp, "adblameinfo");
2114         MPINIT(dns_adbentry_t, adb->emp, "adbentry");
2115         MPINIT(dns_adbfind_t, adb->ahmp, "adbfind");
2116         MPINIT(dns_adbaddrinfo_t, adb->aimp, "adbaddrinfo");
2117         MPINIT(dns_adbfetch_t, adb->afmp, "adbfetch");
2118
2119 #undef MPINIT
2120
2121         /*
2122          * Allocate an internal task.
2123          */
2124         result = isc_task_create(adb->taskmgr, 0, &adb->task);
2125         if (result != ISC_R_SUCCESS)
2126                 goto fail3;
2127         isc_task_setname(adb->task, "ADB", adb);
2128
2129         /*
2130          * Normal return.
2131          */
2132         adb->magic = DNS_ADB_MAGIC;
2133         *newadb = adb;
2134         return (ISC_R_SUCCESS);
2135
2136  fail3:
2137         if (adb->task != NULL)
2138                 isc_task_detach(&adb->task);
2139
2140         /* clean up entrylocks */
2141         DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS);
2142
2143  fail2: /* clean up namelocks */
2144         DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS);
2145
2146  fail1: /* clean up only allocated memory */
2147         if (adb->nmp != NULL)
2148                 isc_mempool_destroy(&adb->nmp);
2149         if (adb->nhmp != NULL)
2150                 isc_mempool_destroy(&adb->nhmp);
2151         if (adb->limp != NULL)
2152                 isc_mempool_destroy(&adb->limp);
2153         if (adb->emp != NULL)
2154                 isc_mempool_destroy(&adb->emp);
2155         if (adb->ahmp != NULL)
2156                 isc_mempool_destroy(&adb->ahmp);
2157         if (adb->aimp != NULL)
2158                 isc_mempool_destroy(&adb->aimp);
2159         if (adb->afmp != NULL)
2160                 isc_mempool_destroy(&adb->afmp);
2161
2162         DESTROYLOCK(&adb->overmemlock);
2163  fail0e:
2164         DESTROYLOCK(&adb->reflock);
2165  fail0d:
2166         DESTROYLOCK(&adb->mplock);
2167  fail0c:
2168         DESTROYLOCK(&adb->lock);
2169  fail0b:
2170         isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
2171
2172         return (result);
2173 }
2174
2175 void
2176 dns_adb_attach(dns_adb_t *adb, dns_adb_t **adbx) {
2177
2178         REQUIRE(DNS_ADB_VALID(adb));
2179         REQUIRE(adbx != NULL && *adbx == NULL);
2180
2181         inc_adb_erefcnt(adb);
2182         *adbx = adb;
2183 }
2184
2185 void
2186 dns_adb_detach(dns_adb_t **adbx) {
2187         dns_adb_t *adb;
2188         isc_boolean_t need_exit_check;
2189
2190         REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx));
2191
2192         adb = *adbx;
2193         *adbx = NULL;
2194
2195         INSIST(adb->erefcnt > 0);
2196
2197         LOCK(&adb->reflock);
2198         adb->erefcnt--;
2199         need_exit_check = ISC_TF(adb->erefcnt == 0 && adb->irefcnt == 0);
2200         UNLOCK(&adb->reflock);
2201
2202         if (need_exit_check) {
2203                 LOCK(&adb->lock);
2204                 INSIST(adb->shutting_down);
2205                 check_exit(adb);
2206                 UNLOCK(&adb->lock);
2207         }
2208 }
2209
2210 void
2211 dns_adb_whenshutdown(dns_adb_t *adb, isc_task_t *task, isc_event_t **eventp) {
2212         isc_task_t *clone;
2213         isc_event_t *event;
2214         isc_boolean_t zeroirefcnt = ISC_FALSE;
2215
2216         /*
2217          * Send '*eventp' to 'task' when 'adb' has shutdown.
2218          */
2219
2220         REQUIRE(DNS_ADB_VALID(adb));
2221         REQUIRE(eventp != NULL);
2222
2223         event = *eventp;
2224         *eventp = NULL;
2225
2226         LOCK(&adb->lock);
2227
2228         LOCK(&adb->reflock);
2229         zeroirefcnt = ISC_TF(adb->irefcnt == 0);
2230
2231         if (adb->shutting_down && zeroirefcnt &&
2232             isc_mempool_getallocated(adb->ahmp) == 0) {
2233                 /*
2234                  * We're already shutdown.  Send the event.
2235                  */
2236                 event->ev_sender = adb;
2237                 isc_task_send(task, &event);
2238         } else {
2239                 clone = NULL;
2240                 isc_task_attach(task, &clone);
2241                 event->ev_sender = clone;
2242                 ISC_LIST_APPEND(adb->whenshutdown, event, ev_link);
2243         }
2244
2245         UNLOCK(&adb->reflock);
2246         UNLOCK(&adb->lock);
2247 }
2248
2249 void
2250 dns_adb_shutdown(dns_adb_t *adb) {
2251         isc_boolean_t need_check_exit;
2252
2253         /*
2254          * Shutdown 'adb'.
2255          */
2256
2257         LOCK(&adb->lock);
2258
2259         if (!adb->shutting_down) {
2260                 adb->shutting_down = ISC_TRUE;
2261                 isc_mem_setwater(adb->mctx, water, adb, 0, 0);
2262                 need_check_exit = shutdown_names(adb);
2263                 if (!need_check_exit)
2264                         need_check_exit = shutdown_entries(adb);
2265                 if (need_check_exit)
2266                         check_exit(adb);
2267         }
2268
2269         UNLOCK(&adb->lock);
2270 }
2271
2272 isc_result_t
2273 dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
2274                    void *arg, dns_name_t *name, dns_name_t *qname,
2275                    dns_rdatatype_t qtype, unsigned int options,
2276                    isc_stdtime_t now, dns_name_t *target,
2277                    in_port_t port, dns_adbfind_t **findp)
2278 {
2279         dns_adbfind_t *find;
2280         dns_adbname_t *adbname;
2281         int bucket;
2282         isc_boolean_t want_event, start_at_zone, alias, have_address;
2283         isc_result_t result;
2284         unsigned int wanted_addresses;
2285         unsigned int wanted_fetches;
2286         unsigned int query_pending;
2287
2288         REQUIRE(DNS_ADB_VALID(adb));
2289         if (task != NULL) {
2290                 REQUIRE(action != NULL);
2291         }
2292         REQUIRE(name != NULL);
2293         REQUIRE(qname != NULL);
2294         REQUIRE(findp != NULL && *findp == NULL);
2295         REQUIRE(target == NULL || dns_name_hasbuffer(target));
2296
2297         REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0);
2298
2299         result = ISC_R_UNEXPECTED;
2300         wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK);
2301         wanted_fetches = 0;
2302         query_pending = 0;
2303         want_event = ISC_FALSE;
2304         start_at_zone = ISC_FALSE;
2305         alias = ISC_FALSE;
2306
2307         if (now == 0)
2308                 isc_stdtime_get(&now);
2309
2310         /*
2311          * XXXMLG  Move this comment somewhere else!
2312          *
2313          * Look up the name in our internal database.
2314          *
2315          * Possibilities:  Note that these are not always exclusive.
2316          *
2317          *      No name found.  In this case, allocate a new name header and
2318          *      an initial namehook or two.  If any of these allocations
2319          *      fail, clean up and return ISC_R_NOMEMORY.
2320          *
2321          *      Name found, valid addresses present.  Allocate one addrinfo
2322          *      structure for each found and append it to the linked list
2323          *      of addresses for this header.
2324          *
2325          *      Name found, queries pending.  In this case, if a task was
2326          *      passed in, allocate a job id, attach it to the name's job
2327          *      list and remember to tell the caller that there will be
2328          *      more info coming later.
2329          */
2330
2331         find = new_adbfind(adb);
2332         if (find == NULL)
2333                 return (ISC_R_NOMEMORY);
2334
2335         find->port = port;
2336
2337         /*
2338          * Remember what types of addresses we are interested in.
2339          */
2340         find->options = options;
2341         find->flags |= wanted_addresses;
2342         if (FIND_WANTEVENT(find)) {
2343                 REQUIRE(task != NULL);
2344         }
2345
2346         /*
2347          * Try to see if we know anything about this name at all.
2348          */
2349         bucket = DNS_ADB_INVALIDBUCKET;
2350         adbname = find_name_and_lock(adb, name, find->options, &bucket);
2351         if (adb->name_sd[bucket]) {
2352                 DP(DEF_LEVEL,
2353                    "dns_adb_createfind: returning ISC_R_SHUTTINGDOWN");
2354                 RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
2355                 result = ISC_R_SHUTTINGDOWN;
2356                 goto out;
2357         }
2358
2359         /*
2360          * Nothing found.  Allocate a new adbname structure for this name.
2361          */
2362         if (adbname == NULL) {
2363                 /*
2364                  * See if there is any stale name at the end of list, and purge
2365                  * it if so.
2366                  */
2367                 check_stale_name(adb, bucket, now);
2368
2369                 adbname = new_adbname(adb, name);
2370                 if (adbname == NULL) {
2371                         RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
2372                         result = ISC_R_NOMEMORY;
2373                         goto out;
2374                 }
2375                 link_name(adb, bucket, adbname);
2376                 if (FIND_HINTOK(find))
2377                         adbname->flags |= NAME_HINT_OK;
2378                 if (FIND_GLUEOK(find))
2379                         adbname->flags |= NAME_GLUE_OK;
2380                 if (FIND_STARTATZONE(find))
2381                         adbname->flags |= NAME_STARTATZONE;
2382         } else {
2383                 /* Move this name forward in the LRU list */
2384                 ISC_LIST_UNLINK(adb->names[bucket], adbname, plink);
2385                 ISC_LIST_PREPEND(adb->names[bucket], adbname, plink);
2386         }
2387         adbname->last_used = now;
2388
2389         /*
2390          * Expire old entries, etc.
2391          */
2392         RUNTIME_CHECK(check_expire_namehooks(adbname, now) == ISC_FALSE);
2393
2394         /*
2395          * Do we know that the name is an alias?
2396          */
2397         if (!EXPIRE_OK(adbname->expire_target, now)) {
2398                 /*
2399                  * Yes, it is.
2400                  */
2401                 DP(DEF_LEVEL,
2402                    "dns_adb_createfind: name %p is an alias (cached)",
2403                    adbname);
2404                 alias = ISC_TRUE;
2405                 goto post_copy;
2406         }
2407
2408         /*
2409          * Try to populate the name from the database and/or
2410          * start fetches.  First try looking for an A record
2411          * in the database.
2412          */
2413         if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now)
2414             && WANT_INET(wanted_addresses)) {
2415                 result = dbfind_name(adbname, now, dns_rdatatype_a);
2416                 if (result == ISC_R_SUCCESS) {
2417                         DP(DEF_LEVEL,
2418                            "dns_adb_createfind: found A for name %p in db",
2419                            adbname);
2420                         goto v6;
2421                 }
2422
2423                 /*
2424                  * Did we get a CNAME or DNAME?
2425                  */
2426                 if (result == DNS_R_ALIAS) {
2427                         DP(DEF_LEVEL,
2428                            "dns_adb_createfind: name %p is an alias",
2429                            adbname);
2430                         alias = ISC_TRUE;
2431                         goto post_copy;
2432                 }
2433
2434                 /*
2435                  * If the name doesn't exist at all, don't bother with
2436                  * v6 queries; they won't work.
2437                  *
2438                  * If the name does exist but we didn't get our data, go
2439                  * ahead and try AAAA.
2440                  *
2441                  * If the result is neither of these, try a fetch for A.
2442                  */
2443                 if (NXDOMAIN_RESULT(result))
2444                         goto fetch;
2445                 else if (NXRRSET_RESULT(result))
2446                         goto v6;
2447
2448                 if (!NAME_FETCH_V4(adbname))
2449                         wanted_fetches |= DNS_ADBFIND_INET;
2450         }
2451
2452  v6:
2453         if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now)
2454             && WANT_INET6(wanted_addresses)) {
2455                 result = dbfind_name(adbname, now, dns_rdatatype_aaaa);
2456                 if (result == ISC_R_SUCCESS) {
2457                         DP(DEF_LEVEL,
2458                            "dns_adb_createfind: found AAAA for name %p",
2459                            adbname);
2460                         goto fetch;
2461                 }
2462
2463                 /*
2464                  * Did we get a CNAME or DNAME?
2465                  */
2466                 if (result == DNS_R_ALIAS) {
2467                         DP(DEF_LEVEL,
2468                            "dns_adb_createfind: name %p is an alias",
2469                            adbname);
2470                         alias = ISC_TRUE;
2471                         goto post_copy;
2472                 }
2473
2474                 /*
2475                  * Listen to negative cache hints, and don't start
2476                  * another query.
2477                  */
2478                 if (NCACHE_RESULT(result) || AUTH_NX(result))
2479                         goto fetch;
2480
2481                 if (!NAME_FETCH_V6(adbname))
2482                         wanted_fetches |= DNS_ADBFIND_INET6;
2483         }
2484
2485  fetch:
2486         if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) ||
2487             (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname)))
2488                 have_address = ISC_TRUE;
2489         else
2490                 have_address = ISC_FALSE;
2491         if (wanted_fetches != 0 &&
2492             ! (FIND_AVOIDFETCHES(find) && have_address)) {
2493                 /*
2494                  * We're missing at least one address family.  Either the
2495                  * caller hasn't instructed us to avoid fetches, or we don't
2496                  * know anything about any of the address families that would
2497                  * be acceptable so we have to launch fetches.
2498                  */
2499
2500                 if (FIND_STARTATZONE(find))
2501                         start_at_zone = ISC_TRUE;
2502
2503                 /*
2504                  * Start V4.
2505                  */
2506                 if (WANT_INET(wanted_fetches) &&
2507                     fetch_name(adbname, start_at_zone,
2508                                dns_rdatatype_a) == ISC_R_SUCCESS) {
2509                         DP(DEF_LEVEL,
2510                            "dns_adb_createfind: started A fetch for name %p",
2511                            adbname);
2512                 }
2513
2514                 /*
2515                  * Start V6.
2516                  */
2517                 if (WANT_INET6(wanted_fetches) &&
2518                     fetch_name(adbname, start_at_zone,
2519                                dns_rdatatype_aaaa) == ISC_R_SUCCESS) {
2520                         DP(DEF_LEVEL,
2521                            "dns_adb_createfind: "
2522                            "started AAAA fetch for name %p",
2523                            adbname);
2524                 }
2525         }
2526
2527         /*
2528          * Run through the name and copy out the bits we are
2529          * interested in.
2530          */
2531         copy_namehook_lists(adb, find, qname, qtype, adbname, now);
2532
2533  post_copy:
2534         if (NAME_FETCH_V4(adbname))
2535                 query_pending |= DNS_ADBFIND_INET;
2536         if (NAME_FETCH_V6(adbname))
2537                 query_pending |= DNS_ADBFIND_INET6;
2538
2539         /*
2540          * Attach to the name's query list if there are queries
2541          * already running, and we have been asked to.
2542          */
2543         want_event = ISC_TRUE;
2544         if (!FIND_WANTEVENT(find))
2545                 want_event = ISC_FALSE;
2546         if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find))
2547                 want_event = ISC_FALSE;
2548         if ((wanted_addresses & query_pending) == 0)
2549                 want_event = ISC_FALSE;
2550         if (alias)
2551                 want_event = ISC_FALSE;
2552         if (want_event) {
2553                 find->adbname = adbname;
2554                 find->name_bucket = bucket;
2555                 ISC_LIST_APPEND(adbname->finds, find, plink);
2556                 find->query_pending = (query_pending & wanted_addresses);
2557                 find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
2558                 find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK);
2559                 DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p",
2560                    find, adbname);
2561         } else {
2562                 /*
2563                  * Remove the flag so the caller knows there will never
2564                  * be an event, and set internal flags to fake that
2565                  * the event was sent and freed, so dns_adb_destroyfind() will
2566                  * do the right thing.
2567                  */
2568                 find->query_pending = (query_pending & wanted_addresses);
2569                 find->options &= ~DNS_ADBFIND_WANTEVENT;
2570                 find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED);
2571                 find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
2572         }
2573
2574         find->partial_result |= (adbname->partial_result & wanted_addresses);
2575         if (alias) {
2576                 if (target != NULL) {
2577                         result = dns_name_copy(&adbname->target, target, NULL);
2578                         if (result != ISC_R_SUCCESS)
2579                                 goto out;
2580                 }
2581                 result = DNS_R_ALIAS;
2582         } else
2583                 result = ISC_R_SUCCESS;
2584
2585         /*
2586          * Copy out error flags from the name structure into the find.
2587          */
2588         find->result_v4 = find_err_map[adbname->fetch_err];
2589         find->result_v6 = find_err_map[adbname->fetch6_err];
2590
2591  out:
2592         if (find != NULL) {
2593                 *findp = find;
2594
2595                 if (want_event) {
2596                         isc_task_t *taskp;
2597
2598                         INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0);
2599                         taskp = NULL;
2600                         isc_task_attach(task, &taskp);
2601                         find->event.ev_sender = taskp;
2602                         find->event.ev_action = action;
2603                         find->event.ev_arg = arg;
2604                 }
2605         }
2606
2607         UNLOCK(&adb->namelocks[bucket]);
2608
2609         return (result);
2610 }
2611
2612 void
2613 dns_adb_destroyfind(dns_adbfind_t **findp) {
2614         dns_adbfind_t *find;
2615         dns_adbentry_t *entry;
2616         dns_adbaddrinfo_t *ai;
2617         int bucket;
2618         dns_adb_t *adb;
2619
2620         REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp));
2621         find = *findp;
2622         *findp = NULL;
2623
2624         LOCK(&find->lock);
2625
2626         DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find);
2627
2628         adb = find->adb;
2629         REQUIRE(DNS_ADB_VALID(adb));
2630
2631         REQUIRE(FIND_EVENTFREED(find));
2632
2633         bucket = find->name_bucket;
2634         INSIST(bucket == DNS_ADB_INVALIDBUCKET);
2635
2636         UNLOCK(&find->lock);
2637
2638         /*
2639          * The find doesn't exist on any list, and nothing is locked.
2640          * Return the find to the memory pool, and decrement the adb's
2641          * reference count.
2642          */
2643         ai = ISC_LIST_HEAD(find->list);
2644         while (ai != NULL) {
2645                 ISC_LIST_UNLINK(find->list, ai, publink);
2646                 entry = ai->entry;
2647                 ai->entry = NULL;
2648                 INSIST(DNS_ADBENTRY_VALID(entry));
2649                 RUNTIME_CHECK(dec_entry_refcnt(adb, entry, ISC_TRUE) ==
2650                               ISC_FALSE);
2651                 free_adbaddrinfo(adb, &ai);
2652                 ai = ISC_LIST_HEAD(find->list);
2653         }
2654
2655         /*
2656          * WARNING:  The find is freed with the adb locked.  This is done
2657          * to avoid a race condition where we free the find, some other
2658          * thread tests to see if it should be destroyed, detects it should
2659          * be, destroys it, and then we try to lock it for our check, but the
2660          * lock is destroyed.
2661          */
2662         LOCK(&adb->lock);
2663         if (free_adbfind(adb, &find))
2664                 check_exit(adb);
2665         UNLOCK(&adb->lock);
2666 }
2667
2668 void
2669 dns_adb_cancelfind(dns_adbfind_t *find) {
2670         isc_event_t *ev;
2671         isc_task_t *task;
2672         dns_adb_t *adb;
2673         int bucket;
2674         int unlock_bucket;
2675
2676         LOCK(&find->lock);
2677
2678         DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find);
2679
2680         adb = find->adb;
2681         REQUIRE(DNS_ADB_VALID(adb));
2682
2683         REQUIRE(!FIND_EVENTFREED(find));
2684         REQUIRE(FIND_WANTEVENT(find));
2685
2686         bucket = find->name_bucket;
2687         if (bucket == DNS_ADB_INVALIDBUCKET)
2688                 goto cleanup;
2689
2690         /*
2691          * We need to get the adbname's lock to unlink the find.
2692          */
2693         unlock_bucket = bucket;
2694         violate_locking_hierarchy(&find->lock, &adb->namelocks[unlock_bucket]);
2695         bucket = find->name_bucket;
2696         if (bucket != DNS_ADB_INVALIDBUCKET) {
2697                 ISC_LIST_UNLINK(find->adbname->finds, find, plink);
2698                 find->adbname = NULL;
2699                 find->name_bucket = DNS_ADB_INVALIDBUCKET;
2700         }
2701         UNLOCK(&adb->namelocks[unlock_bucket]);
2702         bucket = DNS_ADB_INVALIDBUCKET;
2703
2704  cleanup:
2705
2706         if (!FIND_EVENTSENT(find)) {
2707                 ev = &find->event;
2708                 task = ev->ev_sender;
2709                 ev->ev_sender = find;
2710                 ev->ev_type = DNS_EVENT_ADBCANCELED;
2711                 ev->ev_destroy = event_free;
2712                 ev->ev_destroy_arg = find;
2713                 find->result_v4 = ISC_R_CANCELED;
2714                 find->result_v6 = ISC_R_CANCELED;
2715
2716                 DP(DEF_LEVEL, "sending event %p to task %p for find %p",
2717                    ev, task, find);
2718
2719                 isc_task_sendanddetach(&task, (isc_event_t **)&ev);
2720         }
2721
2722         UNLOCK(&find->lock);
2723 }
2724
2725 void
2726 dns_adb_dump(dns_adb_t *adb, FILE *f) {
2727         int i;
2728         isc_stdtime_t now;
2729
2730         REQUIRE(DNS_ADB_VALID(adb));
2731         REQUIRE(f != NULL);
2732
2733         /*
2734          * Lock the adb itself, lock all the name buckets, then lock all
2735          * the entry buckets.  This should put the adb into a state where
2736          * nothing can change, so we can iterate through everything and
2737          * print at our leisure.
2738          */
2739
2740         LOCK(&adb->lock);
2741         isc_stdtime_get(&now);
2742
2743         for (i = 0; i < NBUCKETS; i++)
2744                 RUNTIME_CHECK(cleanup_names(adb, i, now) == ISC_FALSE);
2745         for (i = 0; i < NBUCKETS; i++)
2746                 RUNTIME_CHECK(cleanup_entries(adb, i, now) == ISC_FALSE);
2747
2748         dump_adb(adb, f, ISC_FALSE, now);
2749         UNLOCK(&adb->lock);
2750 }
2751
2752 static void
2753 dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) {
2754         if (value == INT_MAX)
2755                 return;
2756         fprintf(f, " [%s TTL %d]", legend, value - now);
2757 }
2758
2759 static void
2760 dump_adb(dns_adb_t *adb, FILE *f, isc_boolean_t debug, isc_stdtime_t now) {
2761         int i;
2762         dns_adbname_t *name;
2763         dns_adbentry_t *entry;
2764
2765         fprintf(f, ";\n; Address database dump\n;\n");
2766         if (debug)
2767                 fprintf(f, "; addr %p, erefcnt %u, irefcnt %u, finds out %u\n",
2768                         adb, adb->erefcnt, adb->irefcnt,
2769                         isc_mempool_getallocated(adb->nhmp));
2770
2771         for (i = 0; i < NBUCKETS; i++)
2772                 LOCK(&adb->namelocks[i]);
2773         for (i = 0; i < NBUCKETS; i++)
2774                 LOCK(&adb->entrylocks[i]);
2775
2776         /*
2777          * Dump the names
2778          */
2779         for (i = 0; i < NBUCKETS; i++) {
2780                 name = ISC_LIST_HEAD(adb->names[i]);
2781                 if (name == NULL)
2782                         continue;
2783                 if (debug)
2784                         fprintf(f, "; bucket %d\n", i);
2785                 for (;
2786                      name != NULL;
2787                      name = ISC_LIST_NEXT(name, plink))
2788                 {
2789                         if (debug)
2790                                 fprintf(f, "; name %p (flags %08x)\n",
2791                                         name, name->flags);
2792
2793                         fprintf(f, "; ");
2794                         print_dns_name(f, &name->name);
2795                         if (dns_name_countlabels(&name->target) > 0) {
2796                                 fprintf(f, " alias ");
2797                                 print_dns_name(f, &name->target);
2798                         }
2799
2800                         dump_ttl(f, "v4", name->expire_v4, now);
2801                         dump_ttl(f, "v6", name->expire_v6, now);
2802                         dump_ttl(f, "target", name->expire_target, now);
2803
2804                         fprintf(f, " [v4 %s] [v6 %s]",
2805                                 errnames[name->fetch_err],
2806                                 errnames[name->fetch6_err]);
2807
2808                         fprintf(f, "\n");
2809
2810                         print_namehook_list(f, "v4", &name->v4, debug, now);
2811                         print_namehook_list(f, "v6", &name->v6, debug, now);
2812
2813                         if (debug)
2814                                 print_fetch_list(f, name);
2815                         if (debug)
2816                                 print_find_list(f, name);
2817
2818                 }
2819         }
2820
2821         fprintf(f, ";\n; Unassociated entries\n;\n");
2822
2823         for (i = 0; i < NBUCKETS; i++) {
2824                 entry = ISC_LIST_HEAD(adb->entries[i]);
2825                 while (entry != NULL) {
2826                         if (entry->refcnt == 0)
2827                                 dump_entry(f, entry, debug, now);
2828                         entry = ISC_LIST_NEXT(entry, plink);
2829                 }
2830         }
2831
2832         /*
2833          * Unlock everything
2834          */
2835         for (i = 0; i < NBUCKETS; i++)
2836                 UNLOCK(&adb->entrylocks[i]);
2837         for (i = 0; i < NBUCKETS; i++)
2838                 UNLOCK(&adb->namelocks[i]);
2839 }
2840
2841 static void
2842 dump_entry(FILE *f, dns_adbentry_t *entry, isc_boolean_t debug,
2843            isc_stdtime_t now)
2844 {
2845         char addrbuf[ISC_NETADDR_FORMATSIZE];
2846         char typebuf[DNS_RDATATYPE_FORMATSIZE];
2847         isc_netaddr_t netaddr;
2848         dns_adblameinfo_t *li;
2849
2850         isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
2851         isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));
2852
2853         if (debug)
2854                 fprintf(f, ";\t%p: refcnt %u\n", entry, entry->refcnt);
2855
2856         fprintf(f, ";\t%s [srtt %u] [flags %08x]",
2857                 addrbuf, entry->srtt, entry->flags);
2858         if (entry->expires != 0)
2859                 fprintf(f, " [ttl %d]", entry->expires - now);
2860         fprintf(f, "\n");
2861         for (li = ISC_LIST_HEAD(entry->lameinfo);
2862              li != NULL;
2863              li = ISC_LIST_NEXT(li, plink)) {
2864                 fprintf(f, ";\t\t");
2865                 print_dns_name(f, &li->qname);
2866                 dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf));
2867                 fprintf(f, " %s [lame TTL %d]\n", typebuf,
2868                         li->lame_timer - now);
2869         }
2870 }
2871
2872 void
2873 dns_adb_dumpfind(dns_adbfind_t *find, FILE *f) {
2874         char tmp[512];
2875         const char *tmpp;
2876         dns_adbaddrinfo_t *ai;
2877         isc_sockaddr_t *sa;
2878
2879         /*
2880          * Not used currently, in the API Just In Case we
2881          * want to dump out the name and/or entries too.
2882          */
2883
2884         LOCK(&find->lock);
2885
2886         fprintf(f, ";Find %p\n", find);
2887         fprintf(f, ";\tqpending %08x partial %08x options %08x flags %08x\n",
2888                 find->query_pending, find->partial_result,
2889                 find->options, find->flags);
2890         fprintf(f, ";\tname_bucket %d, name %p, event sender %p\n",
2891                 find->name_bucket, find->adbname, find->event.ev_sender);
2892
2893         ai = ISC_LIST_HEAD(find->list);
2894         if (ai != NULL)
2895                 fprintf(f, "\tAddresses:\n");
2896         while (ai != NULL) {
2897                 sa = &ai->sockaddr;
2898                 switch (sa->type.sa.sa_family) {
2899                 case AF_INET:
2900                         tmpp = inet_ntop(AF_INET, &sa->type.sin.sin_addr,
2901                                          tmp, sizeof(tmp));
2902                         break;
2903                 case AF_INET6:
2904                         tmpp = inet_ntop(AF_INET6, &sa->type.sin6.sin6_addr,
2905                                          tmp, sizeof(tmp));
2906                         break;
2907                 default:
2908                         tmpp = "UnkFamily";
2909                 }
2910
2911                 if (tmpp == NULL)
2912                         tmpp = "BadAddress";
2913
2914                 fprintf(f, "\t\tentry %p, flags %08x"
2915                         " srtt %u addr %s\n",
2916                         ai->entry, ai->flags, ai->srtt, tmpp);
2917
2918                 ai = ISC_LIST_NEXT(ai, publink);
2919         }
2920
2921         UNLOCK(&find->lock);
2922 }
2923
2924 static void
2925 print_dns_name(FILE *f, dns_name_t *name) {
2926         char buf[DNS_NAME_FORMATSIZE];
2927
2928         INSIST(f != NULL);
2929
2930         dns_name_format(name, buf, sizeof(buf));
2931         fprintf(f, "%s", buf);
2932 }
2933
2934 static void
2935 print_namehook_list(FILE *f, const char *legend, dns_adbnamehooklist_t *list,
2936                     isc_boolean_t debug, isc_stdtime_t now)
2937 {
2938         dns_adbnamehook_t *nh;
2939
2940         for (nh = ISC_LIST_HEAD(*list);
2941              nh != NULL;
2942              nh = ISC_LIST_NEXT(nh, plink))
2943         {
2944                 if (debug)
2945                         fprintf(f, ";\tHook(%s) %p\n", legend, nh);
2946                 dump_entry(f, nh->entry, debug, now);
2947         }
2948 }
2949
2950 static inline void
2951 print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) {
2952         fprintf(f, "\t\tFetch(%s): %p -> { fetch %p }\n",
2953                 type, ft, ft->fetch);
2954 }
2955
2956 static void
2957 print_fetch_list(FILE *f, dns_adbname_t *n) {
2958         if (NAME_FETCH_A(n))
2959                 print_fetch(f, n->fetch_a, "A");
2960         if (NAME_FETCH_AAAA(n))
2961                 print_fetch(f, n->fetch_aaaa, "AAAA");
2962 }
2963
2964 static void
2965 print_find_list(FILE *f, dns_adbname_t *name) {
2966         dns_adbfind_t *find;
2967
2968         find = ISC_LIST_HEAD(name->finds);
2969         while (find != NULL) {
2970                 dns_adb_dumpfind(find, f);
2971                 find = ISC_LIST_NEXT(find, plink);
2972         }
2973 }
2974
2975 static isc_result_t
2976 dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype)
2977 {
2978         isc_result_t result;
2979         dns_rdataset_t rdataset;
2980         dns_adb_t *adb;
2981         dns_fixedname_t foundname;
2982         dns_name_t *fname;
2983
2984         INSIST(DNS_ADBNAME_VALID(adbname));
2985         adb = adbname->adb;
2986         INSIST(DNS_ADB_VALID(adb));
2987         INSIST(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
2988
2989         dns_fixedname_init(&foundname);
2990         fname = dns_fixedname_name(&foundname);
2991         dns_rdataset_init(&rdataset);
2992
2993         if (rdtype == dns_rdatatype_a)
2994                 adbname->fetch_err = FIND_ERR_UNEXPECTED;
2995         else
2996                 adbname->fetch6_err = FIND_ERR_UNEXPECTED;
2997
2998         result = dns_view_find(adb->view, &adbname->name, rdtype, now,
2999                                NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0,
3000                                ISC_TF(NAME_HINTOK(adbname)),
3001                                NULL, NULL, fname, &rdataset, NULL);
3002
3003         /* XXXVIX this switch statement is too sparse to gen a jump table. */
3004         switch (result) {
3005         case DNS_R_GLUE:
3006         case DNS_R_HINT:
3007         case ISC_R_SUCCESS:
3008                 /*
3009                  * Found in the database.  Even if we can't copy out
3010                  * any information, return success, or else a fetch
3011                  * will be made, which will only make things worse.
3012                  */
3013                 if (rdtype == dns_rdatatype_a)
3014                         adbname->fetch_err = FIND_ERR_SUCCESS;
3015                 else
3016                         adbname->fetch6_err = FIND_ERR_SUCCESS;
3017                 result = import_rdataset(adbname, &rdataset, now);
3018                 break;
3019         case DNS_R_NXDOMAIN:
3020         case DNS_R_NXRRSET:
3021                 /*
3022                  * We're authoritative and the data doesn't exist.
3023                  * Make up a negative cache entry so we don't ask again
3024                  * for a while.
3025                  *
3026                  * XXXRTH  What time should we use?  I'm putting in 30 seconds
3027                  * for now.
3028                  */
3029                 if (rdtype == dns_rdatatype_a) {
3030                         adbname->expire_v4 = now + 30;
3031                         DP(NCACHE_LEVEL,
3032                            "adb name %p: Caching auth negative entry for A",
3033                            adbname);
3034                         if (result == DNS_R_NXDOMAIN)
3035                                 adbname->fetch_err = FIND_ERR_NXDOMAIN;
3036                         else
3037                                 adbname->fetch_err = FIND_ERR_NXRRSET;
3038                 } else {
3039                         DP(NCACHE_LEVEL,
3040                            "adb name %p: Caching auth negative entry for AAAA",
3041                            adbname);
3042                         adbname->expire_v6 = now + 30;
3043                         if (result == DNS_R_NXDOMAIN)
3044                                 adbname->fetch6_err = FIND_ERR_NXDOMAIN;
3045                         else
3046                                 adbname->fetch6_err = FIND_ERR_NXRRSET;
3047                 }
3048                 break;
3049         case DNS_R_NCACHENXDOMAIN:
3050         case DNS_R_NCACHENXRRSET:
3051                 /*
3052                  * We found a negative cache entry.  Pull the TTL from it
3053                  * so we won't ask again for a while.
3054                  */
3055                 rdataset.ttl = ttlclamp(rdataset.ttl);
3056                 if (rdtype == dns_rdatatype_a) {
3057                         adbname->expire_v4 = rdataset.ttl + now;
3058                         if (result == DNS_R_NCACHENXDOMAIN)
3059                                 adbname->fetch_err = FIND_ERR_NXDOMAIN;
3060                         else
3061                                 adbname->fetch_err = FIND_ERR_NXRRSET;
3062                         DP(NCACHE_LEVEL,
3063                           "adb name %p: Caching negative entry for A (ttl %u)",
3064                            adbname, rdataset.ttl);
3065                 } else {
3066                         DP(NCACHE_LEVEL,
3067                        "adb name %p: Caching negative entry for AAAA (ttl %u)",
3068                            adbname, rdataset.ttl);
3069                         adbname->expire_v6 = rdataset.ttl + now;
3070                         if (result == DNS_R_NCACHENXDOMAIN)
3071                                 adbname->fetch6_err = FIND_ERR_NXDOMAIN;
3072                         else
3073                                 adbname->fetch6_err = FIND_ERR_NXRRSET;
3074                 }
3075                 break;
3076         case DNS_R_CNAME:
3077         case DNS_R_DNAME:
3078                 /*
3079                  * Clear the hint and glue flags, so this will match
3080                  * more often.
3081                  */
3082                 adbname->flags &= ~(DNS_ADBFIND_GLUEOK | DNS_ADBFIND_HINTOK);
3083
3084                 rdataset.ttl = ttlclamp(rdataset.ttl);
3085                 clean_target(adb, &adbname->target);
3086                 adbname->expire_target = INT_MAX;
3087                 result = set_target(adb, &adbname->name, fname, &rdataset,
3088                                     &adbname->target);
3089                 if (result == ISC_R_SUCCESS) {
3090                         result = DNS_R_ALIAS;
3091                         DP(NCACHE_LEVEL,
3092                            "adb name %p: caching alias target",
3093                            adbname);
3094                         adbname->expire_target = rdataset.ttl + now;
3095                 }
3096                 if (rdtype == dns_rdatatype_a)
3097                         adbname->fetch_err = FIND_ERR_SUCCESS;
3098                 else
3099                         adbname->fetch6_err = FIND_ERR_SUCCESS;
3100                 break;
3101         }
3102
3103         if (dns_rdataset_isassociated(&rdataset))
3104                 dns_rdataset_disassociate(&rdataset);
3105
3106         return (result);
3107 }
3108
3109 static void
3110 fetch_callback(isc_task_t *task, isc_event_t *ev) {
3111         dns_fetchevent_t *dev;
3112         dns_adbname_t *name;
3113         dns_adb_t *adb;
3114         dns_adbfetch_t *fetch;
3115         int bucket;
3116         isc_eventtype_t ev_status;
3117         isc_stdtime_t now;
3118         isc_result_t result;
3119         unsigned int address_type;
3120         isc_boolean_t want_check_exit = ISC_FALSE;
3121
3122         UNUSED(task);
3123
3124         INSIST(ev->ev_type == DNS_EVENT_FETCHDONE);
3125         dev = (dns_fetchevent_t *)ev;
3126         name = ev->ev_arg;
3127         INSIST(DNS_ADBNAME_VALID(name));
3128         adb = name->adb;
3129         INSIST(DNS_ADB_VALID(adb));
3130
3131         bucket = name->lock_bucket;
3132         LOCK(&adb->namelocks[bucket]);
3133
3134         INSIST(NAME_FETCH_A(name) || NAME_FETCH_AAAA(name));
3135         address_type = 0;
3136         if (NAME_FETCH_A(name) && (name->fetch_a->fetch == dev->fetch)) {
3137                 address_type = DNS_ADBFIND_INET;
3138                 fetch = name->fetch_a;
3139                 name->fetch_a = NULL;
3140         } else if (NAME_FETCH_AAAA(name)
3141                    && (name->fetch_aaaa->fetch == dev->fetch)) {
3142                 address_type = DNS_ADBFIND_INET6;
3143                 fetch = name->fetch_aaaa;
3144                 name->fetch_aaaa = NULL;
3145         } else
3146                 fetch = NULL;
3147
3148         INSIST(address_type != 0 && fetch != NULL);
3149
3150         dns_resolver_destroyfetch(&fetch->fetch);
3151         dev->fetch = NULL;
3152
3153         ev_status = DNS_EVENT_ADBNOMOREADDRESSES;
3154
3155         /*
3156          * Cleanup things we don't care about.
3157          */
3158         if (dev->node != NULL)
3159                 dns_db_detachnode(dev->db, &dev->node);
3160         if (dev->db != NULL)
3161                 dns_db_detach(&dev->db);
3162
3163         /*
3164          * If this name is marked as dead, clean up, throwing away
3165          * potentially good data.
3166          */
3167         if (NAME_DEAD(name)) {
3168                 free_adbfetch(adb, &fetch);
3169                 isc_event_free(&ev);
3170
3171                 want_check_exit = kill_name(&name, DNS_EVENT_ADBCANCELED);
3172
3173                 UNLOCK(&adb->namelocks[bucket]);
3174
3175                 if (want_check_exit) {
3176                         LOCK(&adb->lock);
3177                         check_exit(adb);
3178                         UNLOCK(&adb->lock);
3179                 }
3180
3181                 return;
3182         }
3183
3184         isc_stdtime_get(&now);
3185
3186         /*
3187          * If we got a negative cache response, remember it.
3188          */
3189         if (NCACHE_RESULT(dev->result)) {
3190                 dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
3191                 if (address_type == DNS_ADBFIND_INET) {
3192                         DP(NCACHE_LEVEL, "adb fetch name %p: "
3193                            "caching negative entry for A (ttl %u)",
3194                            name, dev->rdataset->ttl);
3195                         name->expire_v4 = ISC_MIN(name->expire_v4,
3196                                                   dev->rdataset->ttl + now);
3197                         if (dev->result == DNS_R_NCACHENXDOMAIN)
3198                                 name->fetch_err = FIND_ERR_NXDOMAIN;
3199                         else
3200                                 name->fetch_err = FIND_ERR_NXRRSET;
3201                         inc_stats(adb, dns_resstatscounter_gluefetchv4fail);
3202                 } else {
3203                         DP(NCACHE_LEVEL, "adb fetch name %p: "
3204                            "caching negative entry for AAAA (ttl %u)",
3205                            name, dev->rdataset->ttl);
3206                         name->expire_v6 = ISC_MIN(name->expire_v6,
3207                                                   dev->rdataset->ttl + now);
3208                         if (dev->result == DNS_R_NCACHENXDOMAIN)
3209                                 name->fetch6_err = FIND_ERR_NXDOMAIN;
3210                         else
3211                                 name->fetch6_err = FIND_ERR_NXRRSET;
3212                         inc_stats(adb, dns_resstatscounter_gluefetchv6fail);
3213                 }
3214                 goto out;
3215         }
3216
3217         /*
3218          * Handle CNAME/DNAME.
3219          */
3220         if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) {
3221                 dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
3222                 clean_target(adb, &name->target);
3223                 name->expire_target = INT_MAX;
3224                 result = set_target(adb, &name->name,
3225                                     dns_fixedname_name(&dev->foundname),
3226                                     dev->rdataset,
3227                                     &name->target);
3228                 if (result == ISC_R_SUCCESS) {
3229                         DP(NCACHE_LEVEL,
3230                            "adb fetch name %p: caching alias target",
3231                            name);
3232                         name->expire_target = dev->rdataset->ttl + now;
3233                 }
3234                 goto check_result;
3235         }
3236
3237         /*
3238          * Did we get back junk?  If so, and there are no more fetches
3239          * sitting out there, tell all the finds about it.
3240          */
3241         if (dev->result != ISC_R_SUCCESS) {
3242                 char buf[DNS_NAME_FORMATSIZE];
3243
3244                 dns_name_format(&name->name, buf, sizeof(buf));
3245                 DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s",
3246                    buf, address_type == DNS_ADBFIND_INET ? "A" : "AAAA",
3247                    dns_result_totext(dev->result));
3248                 /* XXXMLG Don't pound on bad servers. */
3249                 if (address_type == DNS_ADBFIND_INET) {
3250                         name->expire_v4 = ISC_MIN(name->expire_v4, now + 300);
3251                         name->fetch_err = FIND_ERR_FAILURE;
3252                         inc_stats(adb, dns_resstatscounter_gluefetchv4fail);
3253                 } else {
3254                         name->expire_v6 = ISC_MIN(name->expire_v6, now + 300);
3255                         name->fetch6_err = FIND_ERR_FAILURE;
3256                         inc_stats(adb, dns_resstatscounter_gluefetchv6fail);
3257                 }
3258                 goto out;
3259         }
3260
3261         /*
3262          * We got something potentially useful.
3263          */
3264         result = import_rdataset(name, &fetch->rdataset, now);
3265
3266  check_result:
3267         if (result == ISC_R_SUCCESS) {
3268                 ev_status = DNS_EVENT_ADBMOREADDRESSES;
3269                 if (address_type == DNS_ADBFIND_INET)
3270                         name->fetch_err = FIND_ERR_SUCCESS;
3271                 else
3272                         name->fetch6_err = FIND_ERR_SUCCESS;
3273         }
3274
3275  out:
3276         free_adbfetch(adb, &fetch);
3277         isc_event_free(&ev);
3278
3279         clean_finds_at_name(name, ev_status, address_type);
3280
3281         UNLOCK(&adb->namelocks[bucket]);
3282 }
3283
3284 static isc_result_t
3285 fetch_name(dns_adbname_t *adbname,
3286            isc_boolean_t start_at_zone,
3287            dns_rdatatype_t type)
3288 {
3289         isc_result_t result;
3290         dns_adbfetch_t *fetch = NULL;
3291         dns_adb_t *adb;
3292         dns_fixedname_t fixed;
3293         dns_name_t *name;
3294         dns_rdataset_t rdataset;
3295         dns_rdataset_t *nameservers;
3296         unsigned int options;
3297
3298         INSIST(DNS_ADBNAME_VALID(adbname));
3299         adb = adbname->adb;
3300         INSIST(DNS_ADB_VALID(adb));
3301
3302         INSIST((type == dns_rdatatype_a && !NAME_FETCH_V4(adbname)) ||
3303                (type == dns_rdatatype_aaaa && !NAME_FETCH_V6(adbname)));
3304
3305         adbname->fetch_err = FIND_ERR_NOTFOUND;
3306
3307         name = NULL;
3308         nameservers = NULL;
3309         dns_rdataset_init(&rdataset);
3310
3311         options = DNS_FETCHOPT_NOVALIDATE;
3312         if (start_at_zone) {
3313                 DP(ENTER_LEVEL,
3314                    "fetch_name: starting at zone for name %p",
3315                    adbname);
3316                 dns_fixedname_init(&fixed);
3317                 name = dns_fixedname_name(&fixed);
3318                 result = dns_view_findzonecut2(adb->view, &adbname->name, name,
3319                                                0, 0, ISC_TRUE, ISC_FALSE,
3320                                                &rdataset, NULL);
3321                 if (result != ISC_R_SUCCESS && result != DNS_R_HINT)
3322                         goto cleanup;
3323                 nameservers = &rdataset;
3324                 options |= DNS_FETCHOPT_UNSHARED;
3325         }
3326
3327         fetch = new_adbfetch(adb);
3328         if (fetch == NULL) {
3329                 result = ISC_R_NOMEMORY;
3330                 goto cleanup;
3331         }
3332
3333         result = dns_resolver_createfetch(adb->view->resolver, &adbname->name,
3334                                           type, name, nameservers, NULL,
3335                                           options, adb->task, fetch_callback,
3336                                           adbname, &fetch->rdataset, NULL,
3337                                           &fetch->fetch);
3338         if (result != ISC_R_SUCCESS)
3339                 goto cleanup;
3340
3341         if (type == dns_rdatatype_a) {
3342                 adbname->fetch_a = fetch;
3343                 inc_stats(adb, dns_resstatscounter_gluefetchv4);
3344         } else {
3345                 adbname->fetch_aaaa = fetch;
3346                 inc_stats(adb, dns_resstatscounter_gluefetchv6);
3347         }
3348         fetch = NULL;  /* Keep us from cleaning this up below. */
3349
3350  cleanup:
3351         if (fetch != NULL)
3352                 free_adbfetch(adb, &fetch);
3353         if (dns_rdataset_isassociated(&rdataset))
3354                 dns_rdataset_disassociate(&rdataset);
3355
3356         return (result);
3357 }
3358
3359 /*
3360  * XXXMLG Needs to take a find argument and an address info, no zone or adb,
3361  * since these can be extracted from the find itself.
3362  */
3363 isc_result_t
3364 dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, dns_name_t *qname,
3365                  dns_rdatatype_t qtype, isc_stdtime_t expire_time)
3366 {
3367         dns_adblameinfo_t *li;
3368         int bucket;
3369         isc_result_t result = ISC_R_SUCCESS;
3370
3371         REQUIRE(DNS_ADB_VALID(adb));
3372         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3373         REQUIRE(qname != NULL);
3374
3375         bucket = addr->entry->lock_bucket;
3376         LOCK(&adb->entrylocks[bucket]);
3377         li = ISC_LIST_HEAD(addr->entry->lameinfo);
3378         while (li != NULL &&
3379                (li->qtype != qtype || !dns_name_equal(qname, &li->qname)))
3380                 li = ISC_LIST_NEXT(li, plink);
3381         if (li != NULL) {
3382                 if (expire_time > li->lame_timer)
3383                         li->lame_timer = expire_time;
3384                 goto unlock;
3385         }
3386         li = new_adblameinfo(adb, qname, qtype);
3387         if (li == NULL) {
3388                 result = ISC_R_NOMEMORY;
3389                 goto unlock;
3390         }
3391
3392         li->lame_timer = expire_time;
3393
3394         ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink);
3395  unlock:
3396         UNLOCK(&adb->entrylocks[bucket]);
3397
3398         return (result);
3399 }
3400
3401 void
3402 dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
3403                    unsigned int rtt, unsigned int factor)
3404 {
3405         int bucket;
3406         unsigned int new_srtt;
3407         isc_stdtime_t now;
3408
3409         REQUIRE(DNS_ADB_VALID(adb));
3410         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3411         REQUIRE(factor <= 10);
3412
3413         bucket = addr->entry->lock_bucket;
3414         LOCK(&adb->entrylocks[bucket]);
3415
3416         if (factor == DNS_ADB_RTTADJAGE)
3417                 new_srtt = addr->entry->srtt * 98 / 100;
3418         else
3419                 new_srtt = (addr->entry->srtt / 10 * factor)
3420                         + (rtt / 10 * (10 - factor));
3421
3422         addr->entry->srtt = new_srtt;
3423         addr->srtt = new_srtt;
3424
3425         isc_stdtime_get(&now);
3426         addr->entry->expires = now + ADB_ENTRY_WINDOW;
3427
3428         UNLOCK(&adb->entrylocks[bucket]);
3429 }
3430
3431 void
3432 dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
3433                     unsigned int bits, unsigned int mask)
3434 {
3435         int bucket;
3436
3437         REQUIRE(DNS_ADB_VALID(adb));
3438         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3439
3440         bucket = addr->entry->lock_bucket;
3441         LOCK(&adb->entrylocks[bucket]);
3442
3443         addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask);
3444         /*
3445          * Note that we do not update the other bits in addr->flags with
3446          * the most recent values from addr->entry->flags.
3447          */
3448         addr->flags = (addr->flags & ~mask) | (bits & mask);
3449
3450         UNLOCK(&adb->entrylocks[bucket]);
3451 }
3452
3453 isc_result_t
3454 dns_adb_findaddrinfo(dns_adb_t *adb, isc_sockaddr_t *sa,
3455                      dns_adbaddrinfo_t **addrp, isc_stdtime_t now)
3456 {
3457         int bucket;
3458         dns_adbentry_t *entry;
3459         dns_adbaddrinfo_t *addr;
3460         isc_result_t result;
3461         in_port_t port;
3462
3463         REQUIRE(DNS_ADB_VALID(adb));
3464         REQUIRE(addrp != NULL && *addrp == NULL);
3465
3466         UNUSED(now);
3467
3468         result = ISC_R_SUCCESS;
3469         bucket = DNS_ADB_INVALIDBUCKET;
3470         entry = find_entry_and_lock(adb, sa, &bucket, now);
3471         if (adb->entry_sd[bucket]) {
3472                 result = ISC_R_SHUTTINGDOWN;
3473                 goto unlock;
3474         }
3475         if (entry == NULL) {
3476                 /*
3477                  * We don't know anything about this address.
3478                  */
3479                 entry = new_adbentry(adb);
3480                 if (entry == NULL) {
3481                         result = ISC_R_NOMEMORY;
3482                         goto unlock;
3483                 }
3484                 entry->sockaddr = *sa;
3485                 link_entry(adb, bucket, entry);
3486                 DP(ENTER_LEVEL, "findaddrinfo: new entry %p", entry);
3487         } else
3488                 DP(ENTER_LEVEL, "findaddrinfo: found entry %p", entry);
3489
3490         port = isc_sockaddr_getport(sa);
3491         addr = new_adbaddrinfo(adb, entry, port);
3492         if (addr == NULL) {
3493                 result = ISC_R_NOMEMORY;
3494         } else {
3495                 inc_entry_refcnt(adb, entry, ISC_FALSE);
3496                 *addrp = addr;
3497         }
3498
3499  unlock:
3500         UNLOCK(&adb->entrylocks[bucket]);
3501
3502         return (result);
3503 }
3504
3505 void
3506 dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) {
3507         dns_adbaddrinfo_t *addr;
3508         dns_adbentry_t *entry;
3509         int bucket;
3510         isc_stdtime_t now;
3511         isc_boolean_t want_check_exit = ISC_FALSE;
3512
3513         REQUIRE(DNS_ADB_VALID(adb));
3514         REQUIRE(addrp != NULL);
3515         addr = *addrp;
3516         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3517         entry = addr->entry;
3518         REQUIRE(DNS_ADBENTRY_VALID(entry));
3519
3520         isc_stdtime_get(&now);
3521
3522         *addrp = NULL;
3523
3524         bucket = addr->entry->lock_bucket;
3525         LOCK(&adb->entrylocks[bucket]);
3526
3527         entry->expires = now + ADB_ENTRY_WINDOW;
3528
3529         want_check_exit = dec_entry_refcnt(adb, entry, ISC_FALSE);
3530
3531         UNLOCK(&adb->entrylocks[bucket]);
3532
3533         addr->entry = NULL;
3534         free_adbaddrinfo(adb, &addr);
3535
3536         if (want_check_exit) {
3537                 LOCK(&adb->lock);
3538                 check_exit(adb);
3539                 UNLOCK(&adb->lock);
3540         }
3541 }
3542
3543 void
3544 dns_adb_flush(dns_adb_t *adb) {
3545         unsigned int i;
3546
3547         INSIST(DNS_ADB_VALID(adb));
3548
3549         LOCK(&adb->lock);
3550
3551         /*
3552          * Call our cleanup routines.
3553          */
3554         for (i = 0; i < NBUCKETS; i++)
3555                 RUNTIME_CHECK(cleanup_names(adb, i, INT_MAX) == ISC_FALSE);
3556         for (i = 0; i < NBUCKETS; i++)
3557                 RUNTIME_CHECK(cleanup_entries(adb, i, INT_MAX) == ISC_FALSE);
3558
3559 #ifdef DUMP_ADB_AFTER_CLEANING
3560         dump_adb(adb, stdout, ISC_TRUE, INT_MAX);
3561 #endif
3562
3563         UNLOCK(&adb->lock);
3564 }
3565
3566 void
3567 dns_adb_flushname(dns_adb_t *adb, dns_name_t *name) {
3568         dns_adbname_t *adbname;
3569         dns_adbname_t *nextname;
3570         int bucket;
3571
3572         INSIST(DNS_ADB_VALID(adb));
3573
3574         LOCK(&adb->lock);
3575         bucket = dns_name_hash(name, ISC_FALSE) % NBUCKETS;
3576         LOCK(&adb->namelocks[bucket]);
3577         adbname = ISC_LIST_HEAD(adb->names[bucket]);
3578         while (adbname != NULL) {
3579                 nextname = ISC_LIST_NEXT(adbname, plink);
3580                 if (!NAME_DEAD(adbname) &&
3581                     dns_name_equal(name, &adbname->name)) {
3582                         RUNTIME_CHECK(kill_name(&adbname,
3583                                                 DNS_EVENT_ADBCANCELED) ==
3584                                       ISC_FALSE);
3585                 }
3586                 adbname = nextname;
3587         }
3588         UNLOCK(&adb->namelocks[bucket]);
3589         UNLOCK(&adb->lock);
3590 }
3591
3592 static void
3593 water(void *arg, int mark) {
3594         dns_adb_t *adb = arg;
3595         isc_boolean_t overmem = ISC_TF(mark == ISC_MEM_HIWATER);
3596
3597         REQUIRE(DNS_ADB_VALID(adb));
3598
3599         DP(ISC_LOG_DEBUG(1),
3600            "adb reached %s water mark", overmem ? "high" : "low");
3601
3602         /*
3603          * We can't use adb->lock as there is potential for water
3604          * to be called when adb->lock is held.
3605          */
3606         LOCK(&adb->overmemlock);
3607         if (adb->overmem != overmem) {
3608                 adb->overmem = overmem;
3609                 isc_mem_waterack(adb->mctx, mark);
3610         }
3611         UNLOCK(&adb->overmemlock);
3612 }
3613
3614 void
3615 dns_adb_setadbsize(dns_adb_t *adb, isc_uint32_t size) {
3616         isc_uint32_t hiwater;
3617         isc_uint32_t lowater;
3618
3619         INSIST(DNS_ADB_VALID(adb));
3620
3621         if (size != 0 && size < DNS_ADB_MINADBSIZE)
3622                 size = DNS_ADB_MINADBSIZE;
3623
3624         hiwater = size - (size >> 3);   /* Approximately 7/8ths. */
3625         lowater = size - (size >> 2);   /* Approximately 3/4ths. */
3626
3627         if (size == 0 || hiwater == 0 || lowater == 0)
3628                 isc_mem_setwater(adb->mctx, water, adb, 0, 0);
3629         else
3630                 isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater);
3631 }