xref: /netbsd/external/mpl/bind/dist/lib/dns/adb.c (revision 4ac1c27e)

/*	$NetBSD: adb.c,v 1.10 2023/01/25 21:43:29 christos Exp $	*/

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file
 *
 * \note
 * In finds, if task == NULL, no events will be generated, and no events
 * have been sent.  If task != NULL but taskaction == NULL, an event has been
 * posted but not yet freed.  If neither are NULL, no event was posted.
 *
 */

#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>

#include <isc/mutexblock.h>
#include <isc/netaddr.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/stats.h>
#include <isc/string.h> /* Required for HP/UX (and others?) */
#include <isc/task.h>
#include <isc/util.h>

#include <dns/adb.h>
#include <dns/db.h>
#include <dns/events.h>
#include <dns/log.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/stats.h>

#define DNS_ADB_MAGIC		 ISC_MAGIC('D', 'a', 'd', 'b')
#define DNS_ADB_VALID(x)	 ISC_MAGIC_VALID(x, DNS_ADB_MAGIC)
#define DNS_ADBNAME_MAGIC	 ISC_MAGIC('a', 'd', 'b', 'N')
#define DNS_ADBNAME_VALID(x)	 ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC)
#define DNS_ADBNAMEHOOK_MAGIC	 ISC_MAGIC('a', 'd', 'N', 'H')
#define DNS_ADBNAMEHOOK_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC)
#define DNS_ADBLAMEINFO_MAGIC	 ISC_MAGIC('a', 'd', 'b', 'Z')
#define DNS_ADBLAMEINFO_VALID(x) ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC)
#define DNS_ADBENTRY_MAGIC	 ISC_MAGIC('a', 'd', 'b', 'E')
#define DNS_ADBENTRY_VALID(x)	 ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC)
#define DNS_ADBFETCH_MAGIC	 ISC_MAGIC('a', 'd', 'F', '4')
#define DNS_ADBFETCH_VALID(x)	 ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC)
#define DNS_ADBFETCH6_MAGIC	 ISC_MAGIC('a', 'd', 'F', '6')
#define DNS_ADBFETCH6_VALID(x)	 ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC)

/*!
 * For type 3 negative cache entries, we will remember that the address is
 * broken for this long.  XXXMLG This is also used for actual addresses, too.
 * The intent is to keep us from constantly asking about A/AAAA records
 * if the zone has extremely low TTLs.
 */
#define ADB_CACHE_MINIMUM 10	/*%< seconds */
#define ADB_CACHE_MAXIMUM 86400 /*%< seconds (86400 = 24 hours) */
#define ADB_ENTRY_WINDOW  1800	/*%< seconds */

/*%
 * The period in seconds after which an ADB name entry is regarded as stale
 * and forced to be cleaned up.
 * TODO: This should probably be configurable at run-time.
 */
#ifndef ADB_STALE_MARGIN
#define ADB_STALE_MARGIN 1800
#endif /* ifndef ADB_STALE_MARGIN */

#define FREE_ITEMS 64 /*%< free count for memory pools */
#define FILL_COUNT 16 /*%< fill count for memory pools */

#define DNS_ADB_INVALIDBUCKET (-1) /*%< invalid bucket address */

#define DNS_ADB_MINADBSIZE (1024U * 1024U) /*%< 1 Megabyte */

typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t;
typedef struct dns_adbnamehook dns_adbnamehook_t;
typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t;
typedef struct dns_adblameinfo dns_adblameinfo_t;
typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t;
typedef struct dns_adbfetch dns_adbfetch_t;
typedef struct dns_adbfetch6 dns_adbfetch6_t;

/*% dns adb structure */
struct dns_adb {
	unsigned int magic;

	isc_mutex_t lock;
	isc_mutex_t reflock;	 /*%< Covers irefcnt, erefcnt */
	isc_mutex_t overmemlock; /*%< Covers overmem */
	isc_mem_t *mctx;
	dns_view_t *view;

	isc_taskmgr_t *taskmgr;
	isc_task_t *task;
	isc_task_t *excl;

	isc_interval_t tick_interval;
	int next_cleanbucket;

	unsigned int irefcnt;
	unsigned int erefcnt;

	isc_refcount_t ahrefcnt;
	isc_refcount_t nhrefcnt;

	/*!
	 * Bucketized locks and lists for names.
	 *
	 * XXXRTH  Have a per-bucket structure that contains all of these?
	 */
	unsigned int nnames;
	isc_mutex_t namescntlock;
	unsigned int namescnt;
	dns_adbnamelist_t *names;
	dns_adbnamelist_t *deadnames;
	isc_mutex_t *namelocks;
	bool *name_sd;
	unsigned int *name_refcnt;

	/*!
	 * Bucketized locks and lists for entries.
	 *
	 * XXXRTH  Have a per-bucket structure that contains all of these?
	 */
	unsigned int nentries;
	isc_mutex_t entriescntlock;
	unsigned int entriescnt;
	dns_adbentrylist_t *entries;
	dns_adbentrylist_t *deadentries;
	isc_mutex_t *entrylocks;
	bool *entry_sd; /*%< shutting down */
	unsigned int *entry_refcnt;

	isc_event_t cevent;
	bool cevent_out;
	bool shutting_down;
	isc_eventlist_t whenshutdown;
	isc_event_t growentries;
	bool growentries_sent;
	isc_event_t grownames;
	bool grownames_sent;

	uint32_t quota;
	uint32_t atr_freq;
	double atr_low;
	double atr_high;
	double atr_discount;
};

/*
 * XXXMLG  Document these structures.
 */

/*% dns_adbname structure */
struct dns_adbname {
	unsigned int magic;
	dns_name_t name;
	dns_adb_t *adb;
	unsigned int partial_result;
	unsigned int flags;
	int lock_bucket;
	dns_name_t target;
	isc_stdtime_t expire_target;
	isc_stdtime_t expire_v4;
	isc_stdtime_t expire_v6;
	unsigned int chains;
	dns_adbnamehooklist_t v4;
	dns_adbnamehooklist_t v6;
	dns_adbfetch_t *fetch_a;
	dns_adbfetch_t *fetch_aaaa;
	unsigned int fetch_err;
	unsigned int fetch6_err;
	dns_adbfindlist_t finds;
	/* for LRU-based management */
	isc_stdtime_t last_used;

	ISC_LINK(dns_adbname_t) plink;
};

/*% The adbfetch structure */
struct dns_adbfetch {
	unsigned int magic;
	dns_fetch_t *fetch;
	dns_rdataset_t rdataset;
	unsigned int depth;
};

/*%
 * This is a small widget that dangles off a dns_adbname_t.  It contains a
 * pointer to the address information about this host, and a link to the next
 * namehook that will contain the next address this host has.
 */
struct dns_adbnamehook {
	unsigned int magic;
	dns_adbentry_t *entry;
	ISC_LINK(dns_adbnamehook_t) plink;
};

/*%
 * This is a small widget that holds qname-specific information about an
 * address.  Currently limited to lameness, but could just as easily be
 * extended to other types of information about zones.
 */
struct dns_adblameinfo {
	unsigned int magic;

	dns_name_t qname;
	dns_rdatatype_t qtype;
	isc_stdtime_t lame_timer;

	ISC_LINK(dns_adblameinfo_t) plink;
};

/*%
 * An address entry.  It holds quite a bit of information about addresses,
 * including edns state (in "flags"), rtt, and of course the address of
 * the host.
 */
struct dns_adbentry {
	unsigned int magic;

	int lock_bucket;
	unsigned int refcnt;
	unsigned int nh;

	unsigned int flags;
	unsigned int srtt;
	uint16_t udpsize;
	unsigned int completed;
	unsigned int timeouts;
	unsigned char plain;
	unsigned char plainto;
	unsigned char edns;
	unsigned char to4096; /* Our max. */

	uint8_t mode;
	atomic_uint_fast32_t quota;
	atomic_uint_fast32_t active;
	double atr;

	/*
	 * Allow for encapsulated IPv4/IPv6 UDP packet over ethernet.
	 * Ethernet 1500 - IP(20) - IP6(40) - UDP(8) = 1432.
	 */
	unsigned char to1432; /* Ethernet */
	unsigned char to1232; /* IPv6 nofrag */
	unsigned char to512;  /* plain DNS */
	isc_sockaddr_t sockaddr;
	unsigned char *cookie;
	uint16_t cookielen;

	isc_stdtime_t expires;
	isc_stdtime_t lastage;
	/*%<
	 * A nonzero 'expires' field indicates that the entry should
	 * persist until that time.  This allows entries found
	 * using dns_adb_findaddrinfo() to persist for a limited time
	 * even though they are not necessarily associated with a
	 * name.
	 */

	ISC_LIST(dns_adblameinfo_t) lameinfo;
	ISC_LINK(dns_adbentry_t) plink;
};

/*
 * Internal functions (and prototypes).
 */
static dns_adbname_t *
new_adbname(dns_adb_t *, const dns_name_t *);
static void
free_adbname(dns_adb_t *, dns_adbname_t **);
static dns_adbnamehook_t *
new_adbnamehook(dns_adb_t *, dns_adbentry_t *);
static void
free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **);
static dns_adblameinfo_t *
new_adblameinfo(dns_adb_t *, const dns_name_t *, dns_rdatatype_t);
static void
free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **);
static dns_adbentry_t *
new_adbentry(dns_adb_t *);
static void
free_adbentry(dns_adb_t *, dns_adbentry_t **);
static dns_adbfind_t *
new_adbfind(dns_adb_t *);
static bool
free_adbfind(dns_adb_t *, dns_adbfind_t **);
static dns_adbaddrinfo_t *
new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *, in_port_t);
static dns_adbfetch_t *
new_adbfetch(dns_adb_t *);
static void
free_adbfetch(dns_adb_t *, dns_adbfetch_t **);
static dns_adbname_t *
find_name_and_lock(dns_adb_t *, const dns_name_t *, unsigned int, int *);
static dns_adbentry_t *
find_entry_and_lock(dns_adb_t *, const isc_sockaddr_t *, int *, isc_stdtime_t);
static void
dump_adb(dns_adb_t *, FILE *, bool debug, isc_stdtime_t);
static void
print_dns_name(FILE *, const dns_name_t *);
static void
print_namehook_list(FILE *, const char *legend, dns_adb_t *adb,
		    dns_adbnamehooklist_t *list, bool debug, isc_stdtime_t now);
static void
print_find_list(FILE *, dns_adbname_t *);
static void
print_fetch_list(FILE *, dns_adbname_t *);
static bool
dec_adb_irefcnt(dns_adb_t *);
static void
inc_adb_irefcnt(dns_adb_t *);
static void
inc_adb_erefcnt(dns_adb_t *);
static void
inc_entry_refcnt(dns_adb_t *, dns_adbentry_t *, bool);
static bool
dec_entry_refcnt(dns_adb_t *, bool, dns_adbentry_t *, bool);
static void
violate_locking_hierarchy(isc_mutex_t *, isc_mutex_t *);
static bool
clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *);
static void
clean_target(dns_adb_t *, dns_name_t *);
static void
clean_finds_at_name(dns_adbname_t *, isc_eventtype_t, unsigned int);
static bool
check_expire_namehooks(dns_adbname_t *, isc_stdtime_t);
static bool
check_expire_entry(dns_adb_t *, dns_adbentry_t **, isc_stdtime_t);
static void
cancel_fetches_at_name(dns_adbname_t *);
static isc_result_t
dbfind_name(dns_adbname_t *, isc_stdtime_t, dns_rdatatype_t);
static isc_result_t
fetch_name(dns_adbname_t *, bool, unsigned int, isc_counter_t *qc,
	   dns_rdatatype_t);
static void
check_exit(dns_adb_t *);
static void
destroy(dns_adb_t *);
static bool
shutdown_names(dns_adb_t *);
static bool
shutdown_entries(dns_adb_t *);
static void
link_name(dns_adb_t *, int, dns_adbname_t *);
static bool
unlink_name(dns_adb_t *, dns_adbname_t *);
static void
link_entry(dns_adb_t *, int, dns_adbentry_t *);
static bool
unlink_entry(dns_adb_t *, dns_adbentry_t *);
static bool
kill_name(dns_adbname_t **, isc_eventtype_t);
static void
water(void *, int);
static void
dump_entry(FILE *, dns_adb_t *, dns_adbentry_t *, bool, isc_stdtime_t);
static void
adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor,
	   isc_stdtime_t now);
static void
shutdown_task(isc_task_t *task, isc_event_t *ev);
static void
log_quota(dns_adbentry_t *entry, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3);

/*
 * MUST NOT overlap DNS_ADBFIND_* flags!
 */
#define FIND_EVENT_SENT	   0x40000000
#define FIND_EVENT_FREED   0x80000000
#define FIND_EVENTSENT(h)  (((h)->flags & FIND_EVENT_SENT) != 0)
#define FIND_EVENTFREED(h) (((h)->flags & FIND_EVENT_FREED) != 0)

#define NAME_NEEDS_POKE	  0x80000000
#define NAME_IS_DEAD	  0x40000000
#define NAME_HINT_OK	  DNS_ADBFIND_HINTOK
#define NAME_GLUE_OK	  DNS_ADBFIND_GLUEOK
#define NAME_STARTATZONE  DNS_ADBFIND_STARTATZONE
#define NAME_DEAD(n)	  (((n)->flags & NAME_IS_DEAD) != 0)
#define NAME_NEEDSPOKE(n) (((n)->flags & NAME_NEEDS_POKE) != 0)
#define NAME_GLUEOK(n)	  (((n)->flags & NAME_GLUE_OK) != 0)
#define NAME_HINTOK(n)	  (((n)->flags & NAME_HINT_OK) != 0)

/*
 * Private flag(s) for entries.
 * MUST NOT overlap FCTX_ADDRINFO_xxx and DNS_FETCHOPT_NOEDNS0.
 */
#define ENTRY_IS_DEAD 0x00400000

/*
 * To the name, address classes are all that really exist.  If it has a
 * V6 address it doesn't care if it came from a AAAA query.
 */
#define NAME_HAS_V4(n)	  (!ISC_LIST_EMPTY((n)->v4))
#define NAME_HAS_V6(n)	  (!ISC_LIST_EMPTY((n)->v6))
#define NAME_HAS_ADDRS(n) (NAME_HAS_V4(n) || NAME_HAS_V6(n))

/*
 * Fetches are broken out into A and AAAA types.  In some cases,
 * however, it makes more sense to test for a particular class of fetches,
 * like V4 or V6 above.
 * Note: since we have removed the support of A6 in adb, FETCH_A and FETCH_AAAA
 * are now equal to FETCH_V4 and FETCH_V6, respectively.
 */
#define NAME_FETCH_A(n)	   ((n)->fetch_a != NULL)
#define NAME_FETCH_AAAA(n) ((n)->fetch_aaaa != NULL)
#define NAME_FETCH_V4(n)   (NAME_FETCH_A(n))
#define NAME_FETCH_V6(n)   (NAME_FETCH_AAAA(n))
#define NAME_FETCH(n)	   (NAME_FETCH_V4(n) || NAME_FETCH_V6(n))

/*
 * Find options and tests to see if there are addresses on the list.
 */
#define FIND_WANTEVENT(fn)	(((fn)->options & DNS_ADBFIND_WANTEVENT) != 0)
#define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0)
#define FIND_AVOIDFETCHES(fn)	(((fn)->options & DNS_ADBFIND_AVOIDFETCHES) != 0)
#define FIND_STARTATZONE(fn)	(((fn)->options & DNS_ADBFIND_STARTATZONE) != 0)
#define FIND_HINTOK(fn)		(((fn)->options & DNS_ADBFIND_HINTOK) != 0)
#define FIND_GLUEOK(fn)		(((fn)->options & DNS_ADBFIND_GLUEOK) != 0)
#define FIND_HAS_ADDRS(fn)	(!ISC_LIST_EMPTY((fn)->list))
#define FIND_RETURNLAME(fn)	(((fn)->options & DNS_ADBFIND_RETURNLAME) != 0)
#define FIND_NOFETCH(fn)	(((fn)->options & DNS_ADBFIND_NOFETCH) != 0)

/*
 * These are currently used on simple unsigned ints, so they are
 * not really associated with any particular type.
 */
#define WANT_INET(x)  (((x)&DNS_ADBFIND_INET) != 0)
#define WANT_INET6(x) (((x)&DNS_ADBFIND_INET6) != 0)

#define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now))

/*
 * Find out if the flags on a name (nf) indicate if it is a hint or
 * glue, and compare this to the appropriate bits set in o, to see if
 * this is ok.
 */
#define GLUE_OK(nf, o)	   (!NAME_GLUEOK(nf) || (((o)&DNS_ADBFIND_GLUEOK) != 0))
#define HINT_OK(nf, o)	   (!NAME_HINTOK(nf) || (((o)&DNS_ADBFIND_HINTOK) != 0))
#define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o))
#define STARTATZONE_MATCHES(nf, o) \
	(((nf)->flags & NAME_STARTATZONE) == ((o)&DNS_ADBFIND_STARTATZONE))

#define ENTER_LEVEL  ISC_LOG_DEBUG(50)
#define EXIT_LEVEL   ENTER_LEVEL
#define CLEAN_LEVEL  ISC_LOG_DEBUG(100)
#define DEF_LEVEL    ISC_LOG_DEBUG(5)
#define NCACHE_LEVEL ISC_LOG_DEBUG(20)

#define NCACHE_RESULT(r) \
	((r) == DNS_R_NCACHENXDOMAIN || (r) == DNS_R_NCACHENXRRSET)
#define AUTH_NX(r) ((r) == DNS_R_NXDOMAIN || (r) == DNS_R_NXRRSET)
#define NXDOMAIN_RESULT(r) \
	((r) == DNS_R_NXDOMAIN || (r) == DNS_R_NCACHENXDOMAIN)
#define NXRRSET_RESULT(r)                                      \
	((r) == DNS_R_NCACHENXRRSET || (r) == DNS_R_NXRRSET || \
	 (r) == DNS_R_HINTNXRRSET)

/*
 * Error state rankings.
 */

#define FIND_ERR_SUCCESS    0 /* highest rank */
#define FIND_ERR_CANCELED   1
#define FIND_ERR_FAILURE    2
#define FIND_ERR_NXDOMAIN   3
#define FIND_ERR_NXRRSET    4
#define FIND_ERR_UNEXPECTED 5
#define FIND_ERR_NOTFOUND   6
#define FIND_ERR_MAX	    7

static const char *errnames[] = { "success",  "canceled", "failure",
				  "nxdomain", "nxrrset",  "unexpected",
				  "not_found" };

#define NEWERR(old, new) (ISC_MIN((old), (new)))

static isc_result_t find_err_map[FIND_ERR_MAX] = {
	ISC_R_SUCCESS, ISC_R_CANCELED,	 ISC_R_FAILURE, DNS_R_NXDOMAIN,
	DNS_R_NXRRSET, ISC_R_UNEXPECTED, ISC_R_NOTFOUND /* not YET found */
};

static void
DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);

static void
DP(int level, const char *format, ...) {
	va_list args;

	va_start(args, format);
	isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
		       level, format, args);
	va_end(args);
}

/*%
 * Increment resolver-related statistics counters.
 */
static void
inc_stats(dns_adb_t *adb, isc_statscounter_t counter) {
	if (adb->view->resstats != NULL) {
		isc_stats_increment(adb->view->resstats, counter);
	}
}

/*%
 * Set adb-related statistics counters.
 */
static void
set_adbstat(dns_adb_t *adb, uint64_t val, isc_statscounter_t counter) {
	if (adb->view->adbstats != NULL) {
		isc_stats_set(adb->view->adbstats, val, counter);
	}
}

static void
dec_adbstats(dns_adb_t *adb, isc_statscounter_t counter) {
	if (adb->view->adbstats != NULL) {
		isc_stats_decrement(adb->view->adbstats, counter);
	}
}

static void
inc_adbstats(dns_adb_t *adb, isc_statscounter_t counter) {
	if (adb->view->adbstats != NULL) {
		isc_stats_increment(adb->view->adbstats, counter);
	}
}

static dns_ttl_t
ttlclamp(dns_ttl_t ttl) {
	if (ttl < ADB_CACHE_MINIMUM) {
		ttl = ADB_CACHE_MINIMUM;
	}
	if (ttl > ADB_CACHE_MAXIMUM) {
		ttl = ADB_CACHE_MAXIMUM;
	}

	return (ttl);
}

/*
 * Hashing is most efficient if the number of buckets is prime.
 * The sequence below is the closest previous primes to 2^n and
 * 1.5 * 2^n, for values of n from 10 to 28.  (The tables will
 * no longer grow beyond 2^28 entries.)
 */
static const unsigned nbuckets[] = {
	1021,	   1531,     2039,     3067,	  4093,	     6143,
	8191,	   12281,    16381,    24571,	  32749,     49193,
	65521,	   98299,    131071,   199603,	  262139,    393209,
	524287,	   768431,   1048573,  1572853,	  2097143,   3145721,
	4194301,   6291449,  8388593,  12582893,  16777213,  25165813,
	33554393,  50331599, 67108859, 100663291, 134217689, 201326557,
	268535431, 0
};

static void
grow_entries(isc_task_t *task, isc_event_t *ev) {
	dns_adb_t *adb;
	dns_adbentry_t *e;
	dns_adbentrylist_t *newdeadentries = NULL;
	dns_adbentrylist_t *newentries = NULL;
	bool *newentry_sd = NULL;
	isc_mutex_t *newentrylocks = NULL;
	isc_result_t result;
	unsigned int *newentry_refcnt = NULL;
	unsigned int i, n, bucket;

	adb = ev->ev_arg;
	INSIST(DNS_ADB_VALID(adb));

	isc_event_free(&ev);

	result = isc_task_beginexclusive(task);
	if (result != ISC_R_SUCCESS) {
		goto check_exit;
	}

	i = 0;
	while (nbuckets[i] != 0 && adb->nentries >= nbuckets[i]) {
		i++;
	}
	if (nbuckets[i] != 0) {
		n = nbuckets[i];
	} else {
		goto done;
	}

	DP(ISC_LOG_INFO, "adb: grow_entries to %u starting", n);

	/*
	 * Are we shutting down?
	 */
	for (i = 0; i < adb->nentries; i++) {
		if (adb->entry_sd[i]) {
			goto cleanup;

			/*
			 * Grab all the resources we need.
			 */
		}
	}

	/*
	 * Grab all the resources we need.
	 */
	newentries = isc_mem_get(adb->mctx, sizeof(*newentries) * n);
	newdeadentries = isc_mem_get(adb->mctx, sizeof(*newdeadentries) * n);
	newentrylocks = isc_mem_get(adb->mctx, sizeof(*newentrylocks) * n);
	newentry_sd = isc_mem_get(adb->mctx, sizeof(*newentry_sd) * n);
	newentry_refcnt = isc_mem_get(adb->mctx, sizeof(*newentry_refcnt) * n);

	/*
	 * Initialise the new resources.
	 */
	isc_mutexblock_init(newentrylocks, n);

	for (i = 0; i < n; i++) {
		ISC_LIST_INIT(newentries[i]);
		ISC_LIST_INIT(newdeadentries[i]);
		newentry_sd[i] = false;
		newentry_refcnt[i] = 0;
		adb->irefcnt++;
	}

	/*
	 * Move entries to new arrays.
	 */
	for (i = 0; i < adb->nentries; i++) {
		e = ISC_LIST_HEAD(adb->entries[i]);
		while (e != NULL) {
			ISC_LIST_UNLINK(adb->entries[i], e, plink);
			bucket = isc_sockaddr_hash(&e->sockaddr, true) % n;
			e->lock_bucket = bucket;
			ISC_LIST_APPEND(newentries[bucket], e, plink);
			INSIST(adb->entry_refcnt[i] > 0);
			adb->entry_refcnt[i]--;
			newentry_refcnt[bucket]++;
			e = ISC_LIST_HEAD(adb->entries[i]);
		}
		e = ISC_LIST_HEAD(adb->deadentries[i]);
		while (e != NULL) {
			ISC_LIST_UNLINK(adb->deadentries[i], e, plink);
			bucket = isc_sockaddr_hash(&e->sockaddr, true) % n;
			e->lock_bucket = bucket;
			ISC_LIST_APPEND(newdeadentries[bucket], e, plink);
			INSIST(adb->entry_refcnt[i] > 0);
			adb->entry_refcnt[i]--;
			newentry_refcnt[bucket]++;
			e = ISC_LIST_HEAD(adb->deadentries[i]);
		}
		INSIST(adb->entry_refcnt[i] == 0);
		adb->irefcnt--;
	}

	/*
	 * Cleanup old resources.
	 */
	isc_mutexblock_destroy(adb->entrylocks, adb->nentries);
	isc_mem_put(adb->mctx, adb->entries,
		    sizeof(*adb->entries) * adb->nentries);
	isc_mem_put(adb->mctx, adb->deadentries,
		    sizeof(*adb->deadentries) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entrylocks,
		    sizeof(*adb->entrylocks) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entry_sd,
		    sizeof(*adb->entry_sd) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entry_refcnt,
		    sizeof(*adb->entry_refcnt) * adb->nentries);

	/*
	 * Install new resources.
	 */
	adb->entries = newentries;
	adb->deadentries = newdeadentries;
	adb->entrylocks = newentrylocks;
	adb->entry_sd = newentry_sd;
	adb->entry_refcnt = newentry_refcnt;
	adb->nentries = n;

	set_adbstat(adb, adb->nentries, dns_adbstats_nentries);

	/*
	 * Only on success do we set adb->growentries_sent to false.
	 * This will prevent us being continuously being called on error.
	 */
	adb->growentries_sent = false;
	goto done;

cleanup:
	if (newentries != NULL) {
		isc_mem_put(adb->mctx, newentries, sizeof(*newentries) * n);
	}
	if (newdeadentries != NULL) {
		isc_mem_put(adb->mctx, newdeadentries,
			    sizeof(*newdeadentries) * n);
	}
	if (newentrylocks != NULL) {
		isc_mem_put(adb->mctx, newentrylocks,
			    sizeof(*newentrylocks) * n);
	}
	if (newentry_sd != NULL) {
		isc_mem_put(adb->mctx, newentry_sd, sizeof(*newentry_sd) * n);
	}
	if (newentry_refcnt != NULL) {
		isc_mem_put(adb->mctx, newentry_refcnt,
			    sizeof(*newentry_refcnt) * n);
	}
done:
	isc_task_endexclusive(task);

check_exit:
	LOCK(&adb->lock);
	if (dec_adb_irefcnt(adb)) {
		check_exit(adb);
	}
	UNLOCK(&adb->lock);
	DP(ISC_LOG_INFO, "adb: grow_entries finished");
}

static void
grow_names(isc_task_t *task, isc_event_t *ev) {
	dns_adb_t *adb;
	dns_adbname_t *name;
	dns_adbnamelist_t *newdeadnames = NULL;
	dns_adbnamelist_t *newnames = NULL;
	bool *newname_sd = NULL;
	isc_mutex_t *newnamelocks = NULL;
	isc_result_t result;
	unsigned int *newname_refcnt = NULL;
	unsigned int i, n;
	unsigned int bucket;

	adb = ev->ev_arg;
	INSIST(DNS_ADB_VALID(adb));

	isc_event_free(&ev);

	result = isc_task_beginexclusive(task);
	if (result != ISC_R_SUCCESS) {
		goto check_exit;
	}

	i = 0;
	while (nbuckets[i] != 0 && adb->nnames >= nbuckets[i]) {
		i++;
	}
	if (nbuckets[i] != 0) {
		n = nbuckets[i];
	} else {
		goto done;
	}

	DP(ISC_LOG_INFO, "adb: grow_names to %u starting", n);

	/*
	 * Are we shutting down?
	 */
	for (i = 0; i < adb->nnames; i++) {
		if (adb->name_sd[i]) {
			goto cleanup;

			/*
			 * Grab all the resources we need.
			 */
		}
	}

	/*
	 * Grab all the resources we need.
	 */
	newnames = isc_mem_get(adb->mctx, sizeof(*newnames) * n);
	newdeadnames = isc_mem_get(adb->mctx, sizeof(*newdeadnames) * n);
	newnamelocks = isc_mem_get(adb->mctx, sizeof(*newnamelocks) * n);
	newname_sd = isc_mem_get(adb->mctx, sizeof(*newname_sd) * n);
	newname_refcnt = isc_mem_get(adb->mctx, sizeof(*newname_refcnt) * n);

	/*
	 * Initialise the new resources.
	 */
	isc_mutexblock_init(newnamelocks, n);

	for (i = 0; i < n; i++) {
		ISC_LIST_INIT(newnames[i]);
		ISC_LIST_INIT(newdeadnames[i]);
		newname_sd[i] = false;
		newname_refcnt[i] = 0;
		adb->irefcnt++;
	}

	/*
	 * Move names to new arrays.
	 */
	for (i = 0; i < adb->nnames; i++) {
		name = ISC_LIST_HEAD(adb->names[i]);
		while (name != NULL) {
			ISC_LIST_UNLINK(adb->names[i], name, plink);
			bucket = dns_name_fullhash(&name->name, true) % n;
			name->lock_bucket = bucket;
			ISC_LIST_APPEND(newnames[bucket], name, plink);
			INSIST(adb->name_refcnt[i] > 0);
			adb->name_refcnt[i]--;
			newname_refcnt[bucket]++;
			name = ISC_LIST_HEAD(adb->names[i]);
		}
		name = ISC_LIST_HEAD(adb->deadnames[i]);
		while (name != NULL) {
			ISC_LIST_UNLINK(adb->deadnames[i], name, plink);
			bucket = dns_name_fullhash(&name->name, true) % n;
			name->lock_bucket = bucket;
			ISC_LIST_APPEND(newdeadnames[bucket], name, plink);
			INSIST(adb->name_refcnt[i] > 0);
			adb->name_refcnt[i]--;
			newname_refcnt[bucket]++;
			name = ISC_LIST_HEAD(adb->deadnames[i]);
		}
		INSIST(adb->name_refcnt[i] == 0);
		adb->irefcnt--;
	}

	/*
	 * Cleanup old resources.
	 */
	isc_mutexblock_destroy(adb->namelocks, adb->nnames);
	isc_mem_put(adb->mctx, adb->names, sizeof(*adb->names) * adb->nnames);
	isc_mem_put(adb->mctx, adb->deadnames,
		    sizeof(*adb->deadnames) * adb->nnames);
	isc_mem_put(adb->mctx, adb->namelocks,
		    sizeof(*adb->namelocks) * adb->nnames);
	isc_mem_put(adb->mctx, adb->name_sd,
		    sizeof(*adb->name_sd) * adb->nnames);
	isc_mem_put(adb->mctx, adb->name_refcnt,
		    sizeof(*adb->name_refcnt) * adb->nnames);

	/*
	 * Install new resources.
	 */
	adb->names = newnames;
	adb->deadnames = newdeadnames;
	adb->namelocks = newnamelocks;
	adb->name_sd = newname_sd;
	adb->name_refcnt = newname_refcnt;
	adb->nnames = n;

	set_adbstat(adb, adb->nnames, dns_adbstats_nnames);

	/*
	 * Only on success do we set adb->grownames_sent to false.
	 * This will prevent us being continuously being called on error.
	 */
	adb->grownames_sent = false;
	goto done;

cleanup:
	if (newnames != NULL) {
		isc_mem_put(adb->mctx, newnames, sizeof(*newnames) * n);
	}
	if (newdeadnames != NULL) {
		isc_mem_put(adb->mctx, newdeadnames, sizeof(*newdeadnames) * n);
	}
	if (newnamelocks != NULL) {
		isc_mem_put(adb->mctx, newnamelocks, sizeof(*newnamelocks) * n);
	}
	if (newname_sd != NULL) {
		isc_mem_put(adb->mctx, newname_sd, sizeof(*newname_sd) * n);
	}
	if (newname_refcnt != NULL) {
		isc_mem_put(adb->mctx, newname_refcnt,
			    sizeof(*newname_refcnt) * n);
	}
done:
	isc_task_endexclusive(task);

check_exit:
	LOCK(&adb->lock);
	if (dec_adb_irefcnt(adb)) {
		check_exit(adb);
	}
	UNLOCK(&adb->lock);
	DP(ISC_LOG_INFO, "adb: grow_names finished");
}

/*
 * Requires the adbname bucket be locked and that no entry buckets be locked.
 *
 * This code handles A and AAAA rdatasets only.
 */
static isc_result_t
import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset,
		isc_stdtime_t now) {
	isc_result_t result;
	dns_adb_t *adb;
	dns_adbnamehook_t *nh;
	dns_adbnamehook_t *anh;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	struct in_addr ina;
	struct in6_addr in6a;
	isc_sockaddr_t sockaddr;
	dns_adbentry_t *foundentry; /* NO CLEAN UP! */
	int addr_bucket;
	bool new_addresses_added;
	dns_rdatatype_t rdtype;
	unsigned int findoptions;
	dns_adbnamehooklist_t *hookhead;

	INSIST(DNS_ADBNAME_VALID(adbname));
	adb = adbname->adb;
	INSIST(DNS_ADB_VALID(adb));

	rdtype = rdataset->type;
	INSIST((rdtype == dns_rdatatype_a) || (rdtype == dns_rdatatype_aaaa));
	if (rdtype == dns_rdatatype_a) {
		findoptions = DNS_ADBFIND_INET;
	} else {
		findoptions = DNS_ADBFIND_INET6;
	}

	addr_bucket = DNS_ADB_INVALIDBUCKET;
	new_addresses_added = false;

	nh = NULL;
	result = dns_rdataset_first(rdataset);
	while (result == ISC_R_SUCCESS) {
		dns_rdata_reset(&rdata);
		dns_rdataset_current(rdataset, &rdata);
		if (rdtype == dns_rdatatype_a) {
			INSIST(rdata.length == 4);
			memmove(&ina.s_addr, rdata.data, 4);
			isc_sockaddr_fromin(&sockaddr, &ina, 0);
			hookhead = &adbname->v4;
		} else {
			INSIST(rdata.length == 16);
			memmove(in6a.s6_addr, rdata.data, 16);
			isc_sockaddr_fromin6(&sockaddr, &in6a, 0);
			hookhead = &adbname->v6;
		}

		INSIST(nh == NULL);
		nh = new_adbnamehook(adb, NULL);
		if (nh == NULL) {
			adbname->partial_result |= findoptions;
			result = ISC_R_NOMEMORY;
			goto fail;
		}

		foundentry = find_entry_and_lock(adb, &sockaddr, &addr_bucket,
						 now);
		if (foundentry == NULL) {
			dns_adbentry_t *entry;

			entry = new_adbentry(adb);
			if (entry == NULL) {
				adbname->partial_result |= findoptions;
				result = ISC_R_NOMEMORY;
				goto fail;
			}

			entry->sockaddr = sockaddr;
			entry->refcnt = 1;
			entry->nh = 1;

			nh->entry = entry;

			link_entry(adb, addr_bucket, entry);
		} else {
			for (anh = ISC_LIST_HEAD(*hookhead); anh != NULL;
			     anh = ISC_LIST_NEXT(anh, plink))
			{
				if (anh->entry == foundentry) {
					break;
				}
			}
			if (anh == NULL) {
				foundentry->refcnt++;
				foundentry->nh++;
				nh->entry = foundentry;
			} else {
				free_adbnamehook(adb, &nh);
			}
		}

		new_addresses_added = true;
		if (nh != NULL) {
			ISC_LIST_APPEND(*hookhead, nh, plink);
		}
		nh = NULL;
		result = dns_rdataset_next(rdataset);
	}

fail:
	if (nh != NULL) {
		free_adbnamehook(adb, &nh);
	}

	if (addr_bucket != DNS_ADB_INVALIDBUCKET) {
		UNLOCK(&adb->entrylocks[addr_bucket]);
	}

	if (rdataset->trust == dns_trust_glue ||
	    rdataset->trust == dns_trust_additional)
	{
		rdataset->ttl = ADB_CACHE_MINIMUM;
	} else if (rdataset->trust == dns_trust_ultimate) {
		rdataset->ttl = 0;
	} else {
		rdataset->ttl = ttlclamp(rdataset->ttl);
	}

	if (rdtype == dns_rdatatype_a) {
		DP(NCACHE_LEVEL, "expire_v4 set to MIN(%u,%u) import_rdataset",
		   adbname->expire_v4, now + rdataset->ttl);
		adbname->expire_v4 = ISC_MIN(
			adbname->expire_v4,
			ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl));
	} else {
		DP(NCACHE_LEVEL, "expire_v6 set to MIN(%u,%u) import_rdataset",
		   adbname->expire_v6, now + rdataset->ttl);
		adbname->expire_v6 = ISC_MIN(
			adbname->expire_v6,
			ISC_MIN(now + ADB_ENTRY_WINDOW, now + rdataset->ttl));
	}

	if (new_addresses_added) {
		/*
		 * Lie a little here.  This is more or less so code that cares
		 * can find out if any new information was added or not.
		 */
		return (ISC_R_SUCCESS);
	}

	return (result);
}

/*
 * Requires the name's bucket be locked.
 */
static bool
kill_name(dns_adbname_t **n, isc_eventtype_t ev) {
	dns_adbname_t *name;
	bool result = false;
	bool result4, result6;
	int bucket;
	dns_adb_t *adb;

	INSIST(n != NULL);
	name = *n;
	*n = NULL;
	INSIST(DNS_ADBNAME_VALID(name));
	adb = name->adb;
	INSIST(DNS_ADB_VALID(adb));

	DP(DEF_LEVEL, "killing name %p", name);

	/*
	 * If we're dead already, just check to see if we should go
	 * away now or not.
	 */
	if (NAME_DEAD(name) && !NAME_FETCH(name)) {
		result = unlink_name(adb, name);
		free_adbname(adb, &name);
		if (result) {
			result = dec_adb_irefcnt(adb);
		}
		return (result);
	}

	/*
	 * Clean up the name's various lists.  These two are destructive
	 * in that they will always empty the list.
	 */
	clean_finds_at_name(name, ev, DNS_ADBFIND_ADDRESSMASK);
	result4 = clean_namehooks(adb, &name->v4);
	result6 = clean_namehooks(adb, &name->v6);
	clean_target(adb, &name->target);
	result = (result4 || result6);

	/*
	 * If fetches are running, cancel them.  If none are running, we can
	 * just kill the name here.
	 */
	if (!NAME_FETCH(name)) {
		INSIST(!result);
		result = unlink_name(adb, name);
		free_adbname(adb, &name);
		if (result) {
			result = dec_adb_irefcnt(adb);
		}
	} else {
		cancel_fetches_at_name(name);
		if (!NAME_DEAD(name)) {
			bucket = name->lock_bucket;
			ISC_LIST_UNLINK(adb->names[bucket], name, plink);
			ISC_LIST_APPEND(adb->deadnames[bucket], name, plink);
			name->flags |= NAME_IS_DEAD;
		}
	}
	return (result);
}

/*
 * Requires the name's bucket be locked and no entry buckets be locked.
 */
static bool
check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now) {
	dns_adb_t *adb;
	bool result4 = false;
	bool result6 = false;

	INSIST(DNS_ADBNAME_VALID(name));
	adb = name->adb;
	INSIST(DNS_ADB_VALID(adb));

	/*
	 * Check to see if we need to remove the v4 addresses
	 */
	if (!NAME_FETCH_V4(name) && EXPIRE_OK(name->expire_v4, now)) {
		if (NAME_HAS_V4(name)) {
			DP(DEF_LEVEL, "expiring v4 for name %p", name);
			result4 = clean_namehooks(adb, &name->v4);
			name->partial_result &= ~DNS_ADBFIND_INET;
		}
		name->expire_v4 = INT_MAX;
		name->fetch_err = FIND_ERR_UNEXPECTED;
	}

	/*
	 * Check to see if we need to remove the v6 addresses
	 */
	if (!NAME_FETCH_V6(name) && EXPIRE_OK(name->expire_v6, now)) {
		if (NAME_HAS_V6(name)) {
			DP(DEF_LEVEL, "expiring v6 for name %p", name);
			result6 = clean_namehooks(adb, &name->v6);
			name->partial_result &= ~DNS_ADBFIND_INET6;
		}
		name->expire_v6 = INT_MAX;
		name->fetch6_err = FIND_ERR_UNEXPECTED;
	}

	/*
	 * Check to see if we need to remove the alias target.
	 */
	if (EXPIRE_OK(name->expire_target, now)) {
		clean_target(adb, &name->target);
		name->expire_target = INT_MAX;
	}
	return (result4 || result6);
}

/*
 * Requires the name's bucket be locked.
 */
static void
link_name(dns_adb_t *adb, int bucket, dns_adbname_t *name) {
	INSIST(name->lock_bucket == DNS_ADB_INVALIDBUCKET);

	ISC_LIST_PREPEND(adb->names[bucket], name, plink);
	name->lock_bucket = bucket;
	adb->name_refcnt[bucket]++;
}

/*
 * Requires the name's bucket be locked.
 */
static bool
unlink_name(dns_adb_t *adb, dns_adbname_t *name) {
	int bucket;
	bool result = false;

	bucket = name->lock_bucket;
	INSIST(bucket != DNS_ADB_INVALIDBUCKET);

	if (NAME_DEAD(name)) {
		ISC_LIST_UNLINK(adb->deadnames[bucket], name, plink);
	} else {
		ISC_LIST_UNLINK(adb->names[bucket], name, plink);
	}
	name->lock_bucket = DNS_ADB_INVALIDBUCKET;
	INSIST(adb->name_refcnt[bucket] > 0);
	adb->name_refcnt[bucket]--;
	if (adb->name_sd[bucket] && adb->name_refcnt[bucket] == 0) {
		result = true;
	}
	return (result);
}

/*
 * Requires the entry's bucket be locked.
 */
static void
link_entry(dns_adb_t *adb, int bucket, dns_adbentry_t *entry) {
	int i;
	dns_adbentry_t *e;

	if (isc_mem_isovermem(adb->mctx)) {
		for (i = 0; i < 2; i++) {
			e = ISC_LIST_TAIL(adb->entries[bucket]);
			if (e == NULL) {
				break;
			}
			if (e->refcnt == 0) {
				unlink_entry(adb, e);
				free_adbentry(adb, &e);
				continue;
			}
			INSIST((e->flags & ENTRY_IS_DEAD) == 0);
			e->flags |= ENTRY_IS_DEAD;
			ISC_LIST_UNLINK(adb->entries[bucket], e, plink);
			ISC_LIST_PREPEND(adb->deadentries[bucket], e, plink);
		}
	}

	ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
	entry->lock_bucket = bucket;
	adb->entry_refcnt[bucket]++;
}

/*
 * Requires the entry's bucket be locked.
 */
static bool
unlink_entry(dns_adb_t *adb, dns_adbentry_t *entry) {
	int bucket;
	bool result = false;

	bucket = entry->lock_bucket;
	INSIST(bucket != DNS_ADB_INVALIDBUCKET);

	if ((entry->flags & ENTRY_IS_DEAD) != 0) {
		ISC_LIST_UNLINK(adb->deadentries[bucket], entry, plink);
	} else {
		ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
	}
	entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
	INSIST(adb->entry_refcnt[bucket] > 0);
	adb->entry_refcnt[bucket]--;
	if (adb->entry_sd[bucket] && adb->entry_refcnt[bucket] == 0) {
		result = true;
	}
	return (result);
}

static void
violate_locking_hierarchy(isc_mutex_t *have, isc_mutex_t *want) {
	if (isc_mutex_trylock(want) != ISC_R_SUCCESS) {
		UNLOCK(have);
		LOCK(want);
		LOCK(have);
	}
}

/*
 * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
 * checked after calling this function.
 */
static bool
shutdown_names(dns_adb_t *adb) {
	unsigned int bucket;
	bool result = false;
	dns_adbname_t *name;
	dns_adbname_t *next_name;

	for (bucket = 0; bucket < adb->nnames; bucket++) {
		LOCK(&adb->namelocks[bucket]);
		adb->name_sd[bucket] = true;

		name = ISC_LIST_HEAD(adb->names[bucket]);
		if (name == NULL) {
			/*
			 * This bucket has no names.  We must decrement the
			 * irefcnt ourselves, since it will not be
			 * automatically triggered by a name being unlinked.
			 */
			INSIST(!result);
			result = dec_adb_irefcnt(adb);
		} else {
			/*
			 * Run through the list.  For each name, clean up finds
			 * found there, and cancel any fetches running.  When
			 * all the fetches are canceled, the name will destroy
			 * itself.
			 */
			while (name != NULL) {
				next_name = ISC_LIST_NEXT(name, plink);
				INSIST(!result);
				result = kill_name(&name,
						   DNS_EVENT_ADBSHUTDOWN);
				name = next_name;
			}
		}

		UNLOCK(&adb->namelocks[bucket]);
	}
	return (result);
}

/*
 * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
 * checked after calling this function.
 */
static bool
shutdown_entries(dns_adb_t *adb) {
	unsigned int bucket;
	bool result = false;
	dns_adbentry_t *entry;
	dns_adbentry_t *next_entry;

	for (bucket = 0; bucket < adb->nentries; bucket++) {
		LOCK(&adb->entrylocks[bucket]);
		adb->entry_sd[bucket] = true;

		entry = ISC_LIST_HEAD(adb->entries[bucket]);
		if (adb->entry_refcnt[bucket] == 0) {
			/*
			 * This bucket has no entries.  We must decrement the
			 * irefcnt ourselves, since it will not be
			 * automatically triggered by an entry being unlinked.
			 */
			result = dec_adb_irefcnt(adb);
		} else {
			/*
			 * Run through the list.  Cleanup any entries not
			 * associated with names, and which are not in use.
			 */
			while (entry != NULL) {
				next_entry = ISC_LIST_NEXT(entry, plink);
				if (entry->refcnt == 0 && entry->expires != 0) {
					result = unlink_entry(adb, entry);
					free_adbentry(adb, &entry);
					if (result) {
						result = dec_adb_irefcnt(adb);
					}
				}
				entry = next_entry;
			}
		}

		UNLOCK(&adb->entrylocks[bucket]);
	}
	return (result);
}

/*
 * Name bucket must be locked
 */
static void
cancel_fetches_at_name(dns_adbname_t *name) {
	if (NAME_FETCH_A(name)) {
		dns_resolver_cancelfetch(name->fetch_a->fetch);
	}

	if (NAME_FETCH_AAAA(name)) {
		dns_resolver_cancelfetch(name->fetch_aaaa->fetch);
	}
}

/*
 * Assumes the name bucket is locked.
 */
static bool
clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) {
	dns_adbentry_t *entry;
	dns_adbnamehook_t *namehook;
	int addr_bucket;
	bool result = false;
	bool overmem = isc_mem_isovermem(adb->mctx);

	addr_bucket = DNS_ADB_INVALIDBUCKET;
	namehook = ISC_LIST_HEAD(*namehooks);
	while (namehook != NULL) {
		INSIST(DNS_ADBNAMEHOOK_VALID(namehook));

		/*
		 * Clean up the entry if needed.
		 */
		entry = namehook->entry;
		if (entry != NULL) {
			INSIST(DNS_ADBENTRY_VALID(entry));

			if (addr_bucket != entry->lock_bucket) {
				if (addr_bucket != DNS_ADB_INVALIDBUCKET) {
					UNLOCK(&adb->entrylocks[addr_bucket]);
				}
				addr_bucket = entry->lock_bucket;
				INSIST(addr_bucket != DNS_ADB_INVALIDBUCKET);
				LOCK(&adb->entrylocks[addr_bucket]);
			}

			entry->nh--;
			result = dec_entry_refcnt(adb, overmem, entry, false);
		}

		/*
		 * Free the namehook
		 */
		namehook->entry = NULL;
		ISC_LIST_UNLINK(*namehooks, namehook, plink);
		free_adbnamehook(adb, &namehook);

		namehook = ISC_LIST_HEAD(*namehooks);
	}

	if (addr_bucket != DNS_ADB_INVALIDBUCKET) {
		UNLOCK(&adb->entrylocks[addr_bucket]);
	}
	return (result);
}

static void
clean_target(dns_adb_t *adb, dns_name_t *target) {
	if (dns_name_countlabels(target) > 0) {
		dns_name_free(target, adb->mctx);
		dns_name_init(target, NULL);
	}
}

static isc_result_t
set_target(dns_adb_t *adb, const dns_name_t *name, const dns_name_t *fname,
	   dns_rdataset_t *rdataset, dns_name_t *target) {
	isc_result_t result;
	dns_namereln_t namereln;
	unsigned int nlabels;
	int order;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_fixedname_t fixed1, fixed2;
	dns_name_t *prefix, *new_target;

	REQUIRE(dns_name_countlabels(target) == 0);

	if (rdataset->type == dns_rdatatype_cname) {
		dns_rdata_cname_t cname;

		/*
		 * Copy the CNAME's target into the target name.
		 */
		result = dns_rdataset_first(rdataset);
		if (result != ISC_R_SUCCESS) {
			return (result);
		}
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_tostruct(&rdata, &cname, NULL);
		if (result != ISC_R_SUCCESS) {
			return (result);
		}
		dns_name_dup(&cname.cname, adb->mctx, target);
		dns_rdata_freestruct(&cname);
	} else {
		dns_rdata_dname_t dname;

		INSIST(rdataset->type == dns_rdatatype_dname);
		namereln = dns_name_fullcompare(name, fname, &order, &nlabels);
		INSIST(namereln == dns_namereln_subdomain);
		/*
		 * Get the target name of the DNAME.
		 */
		result = dns_rdataset_first(rdataset);
		if (result != ISC_R_SUCCESS) {
			return (result);
		}
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_tostruct(&rdata, &dname, NULL);
		if (result != ISC_R_SUCCESS) {
			return (result);
		}
		/*
		 * Construct the new target name.
		 */
		prefix = dns_fixedname_initname(&fixed1);
		new_target = dns_fixedname_initname(&fixed2);
		dns_name_split(name, nlabels, prefix, NULL);
		result = dns_name_concatenate(prefix, &dname.dname, new_target,
					      NULL);
		dns_rdata_freestruct(&dname);
		if (result != ISC_R_SUCCESS) {
			return (result);
		}
		dns_name_dup(new_target, adb->mctx, target);
	}

	return (ISC_R_SUCCESS);
}

/*
 * Assumes nothing is locked, since this is called by the client.
 */
static void
event_free(isc_event_t *event) {
	dns_adbfind_t *find;

	INSIST(event != NULL);
	find = event->ev_destroy_arg;
	INSIST(DNS_ADBFIND_VALID(find));

	LOCK(&find->lock);
	find->flags |= FIND_EVENT_FREED;
	event->ev_destroy_arg = NULL;
	UNLOCK(&find->lock);
}

/*
 * Assumes the name bucket is locked.
 */
static void
clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype,
		    unsigned int addrs) {
	isc_event_t *ev;
	isc_task_t *task;
	dns_adbfind_t *find;
	dns_adbfind_t *next_find;
	bool process;
	unsigned int wanted, notify;

	DP(ENTER_LEVEL,
	   "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x", name,
	   evtype, addrs);

	find = ISC_LIST_HEAD(name->finds);
	while (find != NULL) {
		LOCK(&find->lock);
		next_find = ISC_LIST_NEXT(find, plink);

		process = false;
		wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
		notify = wanted & addrs;

		switch (evtype) {
		case DNS_EVENT_ADBMOREADDRESSES:
			DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES");
			if ((notify) != 0) {
				find->flags &= ~addrs;
				process = true;
			}
			break;
		case DNS_EVENT_ADBNOMOREADDRESSES:
			DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES");
			find->flags &= ~addrs;
			wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
			if (wanted == 0) {
				process = true;
			}
			break;
		default:
			find->flags &= ~addrs;
			process = true;
		}

		if (process) {
			DP(DEF_LEVEL, "cfan: processing find %p", find);
			/*
			 * Unlink the find from the name, letting the caller
			 * call dns_adb_destroyfind() on it to clean it up
			 * later.
			 */
			ISC_LIST_UNLINK(name->finds, find, plink);
			find->adbname = NULL;
			find->name_bucket = DNS_ADB_INVALIDBUCKET;

			INSIST(!FIND_EVENTSENT(find));

			ev = &find->event;
			task = ev->ev_sender;
			ev->ev_sender = find;
			find->result_v4 = find_err_map[name->fetch_err];
			find->result_v6 = find_err_map[name->fetch6_err];
			ev->ev_type = evtype;
			ev->ev_destroy = event_free;
			ev->ev_destroy_arg = find;

			DP(DEF_LEVEL, "sending event %p to task %p for find %p",
			   ev, task, find);

			isc_task_sendanddetach(&task, (isc_event_t **)&ev);
			find->flags |= FIND_EVENT_SENT;
		} else {
			DP(DEF_LEVEL, "cfan: skipping find %p", find);
		}

		UNLOCK(&find->lock);
		find = next_find;
	}
	DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name);
}

static void
check_exit(dns_adb_t *adb) {
	isc_event_t *event;
	/*
	 * The caller must be holding the adb lock.
	 */
	if (adb->shutting_down) {
		/*
		 * If there aren't any external references either, we're
		 * done.  Send the control event to initiate shutdown.
		 */
		INSIST(!adb->cevent_out); /* Sanity check. */
		ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL,
			       DNS_EVENT_ADBCONTROL, shutdown_task, adb, adb,
			       NULL, NULL);
		event = &adb->cevent;
		isc_task_send(adb->task, &event);
		adb->cevent_out = true;
	}
}

static bool
dec_adb_irefcnt(dns_adb_t *adb) {
	isc_event_t *event;
	isc_task_t *etask;
	bool result = false;

	LOCK(&adb->reflock);

	INSIST(adb->irefcnt > 0);
	adb->irefcnt--;

	if (adb->irefcnt == 0) {
		event = ISC_LIST_HEAD(adb->whenshutdown);
		while (event != NULL) {
			ISC_LIST_UNLINK(adb->whenshutdown, event, ev_link);
			etask = event->ev_sender;
			event->ev_sender = adb;
			isc_task_sendanddetach(&etask, &event);
			event = ISC_LIST_HEAD(adb->whenshutdown);
		}
	}

	if (adb->irefcnt == 0 && adb->erefcnt == 0) {
		result = true;
	}
	UNLOCK(&adb->reflock);
	return (result);
}

static void
inc_adb_irefcnt(dns_adb_t *adb) {
	LOCK(&adb->reflock);
	adb->irefcnt++;
	UNLOCK(&adb->reflock);
}

static void
inc_adb_erefcnt(dns_adb_t *adb) {
	LOCK(&adb->reflock);
	adb->erefcnt++;
	UNLOCK(&adb->reflock);
}

static void
inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, bool lock) {
	int bucket;

	bucket = entry->lock_bucket;

	if (lock) {
		LOCK(&adb->entrylocks[bucket]);
	}

	entry->refcnt++;

	if (lock) {
		UNLOCK(&adb->entrylocks[bucket]);
	}
}

static bool
dec_entry_refcnt(dns_adb_t *adb, bool overmem, dns_adbentry_t *entry,
		 bool lock) {
	int bucket;
	bool destroy_entry;
	bool result = false;

	bucket = entry->lock_bucket;

	if (lock) {
		LOCK(&adb->entrylocks[bucket]);
	}

	INSIST(entry->refcnt > 0);
	entry->refcnt--;

	destroy_entry = false;
	if (entry->refcnt == 0 &&
	    (adb->entry_sd[bucket] || entry->expires == 0 || overmem ||
	     (entry->flags & ENTRY_IS_DEAD) != 0))
	{
		destroy_entry = true;
		result = unlink_entry(adb, entry);
	}

	if (lock) {
		UNLOCK(&adb->entrylocks[bucket]);
	}

	if (!destroy_entry) {
		return (result);
	}

	entry->lock_bucket = DNS_ADB_INVALIDBUCKET;

	free_adbentry(adb, &entry);
	if (result) {
		result = dec_adb_irefcnt(adb);
	}

	return (result);
}

static dns_adbname_t *
new_adbname(dns_adb_t *adb, const dns_name_t *dnsname) {
	dns_adbname_t *name;

	name = isc_mem_get(adb->mctx, sizeof(*name));

	dns_name_init(&name->name, NULL);
	dns_name_dup(dnsname, adb->mctx, &name->name);
	dns_name_init(&name->target, NULL);
	name->magic = DNS_ADBNAME_MAGIC;
	name->adb = adb;
	name->partial_result = 0;
	name->flags = 0;
	name->expire_v4 = INT_MAX;
	name->expire_v6 = INT_MAX;
	name->expire_target = INT_MAX;
	name->chains = 0;
	name->lock_bucket = DNS_ADB_INVALIDBUCKET;
	ISC_LIST_INIT(name->v4);
	ISC_LIST_INIT(name->v6);
	name->fetch_a = NULL;
	name->fetch_aaaa = NULL;
	name->fetch_err = FIND_ERR_UNEXPECTED;
	name->fetch6_err = FIND_ERR_UNEXPECTED;
	ISC_LIST_INIT(name->finds);
	ISC_LINK_INIT(name, plink);

	LOCK(&adb->namescntlock);
	adb->namescnt++;
	inc_adbstats(adb, dns_adbstats_namescnt);
	if (!adb->grownames_sent && adb->excl != NULL &&
	    adb->namescnt > (adb->nnames * 8))
	{
		isc_event_t *event = &adb->grownames;
		inc_adb_irefcnt(adb);
		isc_task_send(adb->excl, &event);
		adb->grownames_sent = true;
	}
	UNLOCK(&adb->namescntlock);

	return (name);
}

static void
free_adbname(dns_adb_t *adb, dns_adbname_t **name) {
	dns_adbname_t *n;

	INSIST(name != NULL && DNS_ADBNAME_VALID(*name));
	n = *name;
	*name = NULL;

	INSIST(!NAME_HAS_V4(n));
	INSIST(!NAME_HAS_V6(n));
	INSIST(!NAME_FETCH(n));
	INSIST(ISC_LIST_EMPTY(n->finds));
	INSIST(!ISC_LINK_LINKED(n, plink));
	INSIST(n->lock_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(n->adb == adb);

	n->magic = 0;
	dns_name_free(&n->name, adb->mctx);

	isc_mem_put(adb->mctx, n, sizeof(*n));
	LOCK(&adb->namescntlock);
	adb->namescnt--;
	dec_adbstats(adb, dns_adbstats_namescnt);
	UNLOCK(&adb->namescntlock);
}

static dns_adbnamehook_t *
new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) {
	dns_adbnamehook_t *nh;

	nh = isc_mem_get(adb->mctx, sizeof(*nh));
	isc_refcount_increment0(&adb->nhrefcnt);

	nh->magic = DNS_ADBNAMEHOOK_MAGIC;
	nh->entry = entry;
	ISC_LINK_INIT(nh, plink);

	return (nh);
}

static void
free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) {
	dns_adbnamehook_t *nh;

	INSIST(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook));
	nh = *namehook;
	*namehook = NULL;

	INSIST(nh->entry == NULL);
	INSIST(!ISC_LINK_LINKED(nh, plink));

	nh->magic = 0;

	isc_refcount_decrement(&adb->nhrefcnt);
	isc_mem_put(adb->mctx, nh, sizeof(*nh));
}

static dns_adblameinfo_t *
new_adblameinfo(dns_adb_t *adb, const dns_name_t *qname,
		dns_rdatatype_t qtype) {
	dns_adblameinfo_t *li;

	li = isc_mem_get(adb->mctx, sizeof(*li));

	dns_name_init(&li->qname, NULL);
	dns_name_dup(qname, adb->mctx, &li->qname);
	li->magic = DNS_ADBLAMEINFO_MAGIC;
	li->lame_timer = 0;
	li->qtype = qtype;
	ISC_LINK_INIT(li, plink);

	return (li);
}

static void
free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) {
	dns_adblameinfo_t *li;

	INSIST(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo));
	li = *lameinfo;
	*lameinfo = NULL;

	INSIST(!ISC_LINK_LINKED(li, plink));

	dns_name_free(&li->qname, adb->mctx);

	li->magic = 0;

	isc_mem_put(adb->mctx, li, sizeof(*li));
}

static dns_adbentry_t *
new_adbentry(dns_adb_t *adb) {
	dns_adbentry_t *e;

	e = isc_mem_get(adb->mctx, sizeof(*e));

	e->magic = DNS_ADBENTRY_MAGIC;
	e->lock_bucket = DNS_ADB_INVALIDBUCKET;
	e->refcnt = 0;
	e->nh = 0;
	e->flags = 0;
	e->udpsize = 0;
	e->edns = 0;
	e->completed = 0;
	e->timeouts = 0;
	e->plain = 0;
	e->plainto = 0;
	e->to4096 = 0;
	e->to1432 = 0;
	e->to1232 = 0;
	e->to512 = 0;
	e->cookie = NULL;
	e->cookielen = 0;
	e->srtt = (isc_random_uniform(0x1f)) + 1;
	e->lastage = 0;
	e->expires = 0;
	atomic_init(&e->active, 0);
	e->mode = 0;
	atomic_init(&e->quota, adb->quota);
	e->atr = 0.0;
	ISC_LIST_INIT(e->lameinfo);
	ISC_LINK_INIT(e, plink);
	LOCK(&adb->entriescntlock);
	adb->entriescnt++;
	inc_adbstats(adb, dns_adbstats_entriescnt);
	if (!adb->growentries_sent && adb->excl != NULL &&
	    adb->entriescnt > (adb->nentries * 8))
	{
		isc_event_t *event = &adb->growentries;
		inc_adb_irefcnt(adb);
		isc_task_send(adb->excl, &event);
		adb->growentries_sent = true;
	}
	UNLOCK(&adb->entriescntlock);

	return (e);
}

static void
free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) {
	dns_adbentry_t *e;
	dns_adblameinfo_t *li;

	INSIST(entry != NULL && DNS_ADBENTRY_VALID(*entry));
	e = *entry;
	*entry = NULL;

	INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(e->refcnt == 0);
	INSIST(!ISC_LINK_LINKED(e, plink));

	e->magic = 0;

	if (e->cookie != NULL) {
		isc_mem_put(adb->mctx, e->cookie, e->cookielen);
	}

	li = ISC_LIST_HEAD(e->lameinfo);
	while (li != NULL) {
		ISC_LIST_UNLINK(e->lameinfo, li, plink);
		free_adblameinfo(adb, &li);
		li = ISC_LIST_HEAD(e->lameinfo);
	}

	isc_mem_put(adb->mctx, e, sizeof(*e));
	LOCK(&adb->entriescntlock);
	adb->entriescnt--;
	dec_adbstats(adb, dns_adbstats_entriescnt);
	UNLOCK(&adb->entriescntlock);
}

static dns_adbfind_t *
new_adbfind(dns_adb_t *adb) {
	dns_adbfind_t *h;

	h = isc_mem_get(adb->mctx, sizeof(*h));
	isc_refcount_increment0(&adb->ahrefcnt);

	/*
	 * Public members.
	 */
	h->magic = 0;
	h->adb = adb;
	h->partial_result = 0;
	h->options = 0;
	h->flags = 0;
	h->result_v4 = ISC_R_UNEXPECTED;
	h->result_v6 = ISC_R_UNEXPECTED;
	ISC_LINK_INIT(h, publink);
	ISC_LINK_INIT(h, plink);
	ISC_LIST_INIT(h->list);
	h->adbname = NULL;
	h->name_bucket = DNS_ADB_INVALIDBUCKET;

	/*
	 * private members
	 */
	isc_mutex_init(&h->lock);

	ISC_EVENT_INIT(&h->event, sizeof(isc_event_t), 0, 0, 0, NULL, NULL,
		       NULL, NULL, h);

	inc_adb_irefcnt(adb);
	h->magic = DNS_ADBFIND_MAGIC;
	return (h);
}

static dns_adbfetch_t *
new_adbfetch(dns_adb_t *adb) {
	dns_adbfetch_t *f;

	f = isc_mem_get(adb->mctx, sizeof(*f));

	f->magic = 0;
	f->fetch = NULL;

	dns_rdataset_init(&f->rdataset);

	f->magic = DNS_ADBFETCH_MAGIC;

	return (f);
}

static void
free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetch) {
	dns_adbfetch_t *f;

	INSIST(fetch != NULL && DNS_ADBFETCH_VALID(*fetch));
	f = *fetch;
	*fetch = NULL;

	f->magic = 0;

	if (dns_rdataset_isassociated(&f->rdataset)) {
		dns_rdataset_disassociate(&f->rdataset);
	}

	isc_mem_put(adb->mctx, f, sizeof(*f));
}

static bool
free_adbfind(dns_adb_t *adb, dns_adbfind_t **findp) {
	dns_adbfind_t *find;

	INSIST(findp != NULL && DNS_ADBFIND_VALID(*findp));
	find = *findp;
	*findp = NULL;

	INSIST(!FIND_HAS_ADDRS(find));
	INSIST(!ISC_LINK_LINKED(find, publink));
	INSIST(!ISC_LINK_LINKED(find, plink));
	INSIST(find->name_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(find->adbname == NULL);

	find->magic = 0;

	isc_mutex_destroy(&find->lock);

	isc_refcount_decrement(&adb->ahrefcnt);
	isc_mem_put(adb->mctx, find, sizeof(*find));
	return (dec_adb_irefcnt(adb));
}

/*
 * Copy bits from the entry into the newly allocated addrinfo.  The entry
 * must be locked, and the reference count must be bumped up by one
 * if this function returns a valid pointer.
 */
static dns_adbaddrinfo_t *
new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) {
	dns_adbaddrinfo_t *ai;

	ai = isc_mem_get(adb->mctx, sizeof(*ai));

	ai->magic = DNS_ADBADDRINFO_MAGIC;
	ai->sockaddr = entry->sockaddr;
	isc_sockaddr_setport(&ai->sockaddr, port);
	ai->srtt = entry->srtt;
	ai->flags = entry->flags;
	ai->entry = entry;
	ai->dscp = -1;
	ISC_LINK_INIT(ai, publink);

	return (ai);
}

static void
free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) {
	dns_adbaddrinfo_t *ai;

	INSIST(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo));
	ai = *ainfo;
	*ainfo = NULL;

	INSIST(ai->entry == NULL);
	INSIST(!ISC_LINK_LINKED(ai, publink));

	ai->magic = 0;

	isc_mem_put(adb->mctx, ai, sizeof(*ai));
}

/*
 * Search for the name.  NOTE:  The bucket is kept locked on both
 * success and failure, so it must always be unlocked by the caller!
 *
 * On the first call to this function, *bucketp must be set to
 * DNS_ADB_INVALIDBUCKET.
 */
static dns_adbname_t *
find_name_and_lock(dns_adb_t *adb, const dns_name_t *name, unsigned int options,
		   int *bucketp) {
	dns_adbname_t *adbname;
	int bucket;

	bucket = dns_name_fullhash(name, false) % adb->nnames;

	if (*bucketp == DNS_ADB_INVALIDBUCKET) {
		LOCK(&adb->namelocks[bucket]);
		*bucketp = bucket;
	} else if (*bucketp != bucket) {
		UNLOCK(&adb->namelocks[*bucketp]);
		LOCK(&adb->namelocks[bucket]);
		*bucketp = bucket;
	}

	adbname = ISC_LIST_HEAD(adb->names[bucket]);
	while (adbname != NULL) {
		if (!NAME_DEAD(adbname)) {
			if (dns_name_equal(name, &adbname->name) &&
			    GLUEHINT_OK(adbname, options) &&
			    STARTATZONE_MATCHES(adbname, options))
			{
				return (adbname);
			}
		}
		adbname = ISC_LIST_NEXT(adbname, plink);
	}

	return (NULL);
}

/*
 * Search for the address.  NOTE:  The bucket is kept locked on both
 * success and failure, so it must always be unlocked by the caller.
 *
 * On the first call to this function, *bucketp must be set to
 * DNS_ADB_INVALIDBUCKET.  This will cause a lock to occur.  On
 * later calls (within the same "lock path") it can be left alone, so
 * if this function is called multiple times locking is only done if
 * the bucket changes.
 */
static dns_adbentry_t *
find_entry_and_lock(dns_adb_t *adb, const isc_sockaddr_t *addr, int *bucketp,
		    isc_stdtime_t now) {
	dns_adbentry_t *entry, *entry_next;
	int bucket;

	bucket = isc_sockaddr_hash(addr, true) % adb->nentries;

	if (*bucketp == DNS_ADB_INVALIDBUCKET) {
		LOCK(&adb->entrylocks[bucket]);
		*bucketp = bucket;
	} else if (*bucketp != bucket) {
		UNLOCK(&adb->entrylocks[*bucketp]);
		LOCK(&adb->entrylocks[bucket]);
		*bucketp = bucket;
	}

	/* Search the list, while cleaning up expired entries. */
	for (entry = ISC_LIST_HEAD(adb->entries[bucket]); entry != NULL;
	     entry = entry_next)
	{
		entry_next = ISC_LIST_NEXT(entry, plink);
		(void)check_expire_entry(adb, &entry, now);
		if (entry != NULL &&
		    (entry->expires == 0 || entry->expires > now) &&
		    isc_sockaddr_equal(addr, &entry->sockaddr))
		{
			ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
			ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
			return (entry);
		}
	}

	return (NULL);
}

/*
 * Entry bucket MUST be locked!
 */
static bool
entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, const dns_name_t *qname,
	      dns_rdatatype_t qtype, isc_stdtime_t now) {
	dns_adblameinfo_t *li, *next_li;
	bool is_bad;

	is_bad = false;

	li = ISC_LIST_HEAD(entry->lameinfo);
	if (li == NULL) {
		return (false);
	}
	while (li != NULL) {
		next_li = ISC_LIST_NEXT(li, plink);

		/*
		 * Has the entry expired?
		 */
		if (li->lame_timer < now) {
			ISC_LIST_UNLINK(entry->lameinfo, li, plink);
			free_adblameinfo(adb, &li);
		}

		/*
		 * Order tests from least to most expensive.
		 *
		 * We do not break out of the main loop here as
		 * we use the loop for house keeping.
		 */
		if (li != NULL && !is_bad && li->qtype == qtype &&
		    dns_name_equal(qname, &li->qname))
		{
			is_bad = true;
		}

		li = next_li;
	}

	return (is_bad);
}

static void
log_quota(dns_adbentry_t *entry, const char *fmt, ...) {
	va_list ap;
	char msgbuf[2048];
	char addrbuf[ISC_NETADDR_FORMATSIZE];
	isc_netaddr_t netaddr;

	va_start(ap, fmt);
	vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
	va_end(ap);

	isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
	isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));

	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
		      ISC_LOG_INFO,
		      "adb: quota %s (%" PRIuFAST32 "/%" PRIuFAST32 "): %s",
		      addrbuf, atomic_load_relaxed(&entry->active),
		      atomic_load_relaxed(&entry->quota), msgbuf);
}

static void
copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find,
		    const dns_name_t *qname, dns_rdatatype_t qtype,
		    dns_adbname_t *name, isc_stdtime_t now) {
	dns_adbnamehook_t *namehook;
	dns_adbaddrinfo_t *addrinfo;
	dns_adbentry_t *entry;
	int bucket;

	bucket = DNS_ADB_INVALIDBUCKET;

	if ((find->options & DNS_ADBFIND_INET) != 0) {
		namehook = ISC_LIST_HEAD(name->v4);
		while (namehook != NULL) {
			entry = namehook->entry;
			bucket = entry->lock_bucket;
			INSIST(bucket != DNS_ADB_INVALIDBUCKET);
			LOCK(&adb->entrylocks[bucket]);

			if (dns_adbentry_overquota(entry)) {
				find->options |= (DNS_ADBFIND_LAMEPRUNED |
						  DNS_ADBFIND_OVERQUOTA);
				goto nextv4;
			}

			if (!FIND_RETURNLAME(find) &&
			    entry_is_lame(adb, entry, qname, qtype, now))
			{
				find->options |= DNS_ADBFIND_LAMEPRUNED;
				goto nextv4;
			}
			addrinfo = new_adbaddrinfo(adb, entry, find->port);
			if (addrinfo == NULL) {
				find->partial_result |= DNS_ADBFIND_INET;
				goto out;
			}
			/*
			 * Found a valid entry.  Add it to the find's list.
			 */
			inc_entry_refcnt(adb, entry, false);
			ISC_LIST_APPEND(find->list, addrinfo, publink);
			addrinfo = NULL;
		nextv4:
			UNLOCK(&adb->entrylocks[bucket]);
			bucket = DNS_ADB_INVALIDBUCKET;
			namehook = ISC_LIST_NEXT(namehook, plink);
		}
	}

	if ((find->options & DNS_ADBFIND_INET6) != 0) {
		namehook = ISC_LIST_HEAD(name->v6);
		while (namehook != NULL) {
			entry = namehook->entry;
			bucket = entry->lock_bucket;
			INSIST(bucket != DNS_ADB_INVALIDBUCKET);
			LOCK(&adb->entrylocks[bucket]);

			if (dns_adbentry_overquota(entry)) {
				find->options |= (DNS_ADBFIND_LAMEPRUNED |
						  DNS_ADBFIND_OVERQUOTA);
				goto nextv6;
			}

			if (!FIND_RETURNLAME(find) &&
			    entry_is_lame(adb, entry, qname, qtype, now))
			{
				find->options |= DNS_ADBFIND_LAMEPRUNED;
				goto nextv6;
			}
			addrinfo = new_adbaddrinfo(adb, entry, find->port);
			if (addrinfo == NULL) {
				find->partial_result |= DNS_ADBFIND_INET6;
				goto out;
			}
			/*
			 * Found a valid entry.  Add it to the find's list.
			 */
			inc_entry_refcnt(adb, entry, false);
			ISC_LIST_APPEND(find->list, addrinfo, publink);
			addrinfo = NULL;
		nextv6:
			UNLOCK(&adb->entrylocks[bucket]);
			bucket = DNS_ADB_INVALIDBUCKET;
			namehook = ISC_LIST_NEXT(namehook, plink);
		}
	}

out:
	if (bucket != DNS_ADB_INVALIDBUCKET) {
		UNLOCK(&adb->entrylocks[bucket]);
	}
}

static void
shutdown_task(isc_task_t *task, isc_event_t *ev) {
	dns_adb_t *adb;

	UNUSED(task);

	adb = ev->ev_arg;
	INSIST(DNS_ADB_VALID(adb));

	isc_event_free(&ev);
	/*
	 * Wait for lock around check_exit() call to be released.
	 */
	LOCK(&adb->lock);
	UNLOCK(&adb->lock);
	destroy(adb);
}

/*
 * Name bucket must be locked; adb may be locked; no other locks held.
 */
static bool
check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) {
	dns_adbname_t *name;
	bool result = false;

	INSIST(namep != NULL && DNS_ADBNAME_VALID(*namep));
	name = *namep;

	if (NAME_HAS_V4(name) || NAME_HAS_V6(name)) {
		return (result);
	}
	if (NAME_FETCH(name)) {
		return (result);
	}
	if (!EXPIRE_OK(name->expire_v4, now)) {
		return (result);
	}
	if (!EXPIRE_OK(name->expire_v6, now)) {
		return (result);
	}
	if (!EXPIRE_OK(name->expire_target, now)) {
		return (result);
	}

	/*
	 * The name is empty.  Delete it.
	 */
	*namep = NULL;
	result = kill_name(&name, DNS_EVENT_ADBEXPIRED);

	/*
	 * Our caller, or one of its callers, will be calling check_exit() at
	 * some point, so we don't need to do it here.
	 */
	return (result);
}

/*%
 * Examine the tail entry of the LRU list to see if it expires or is stale
 * (unused for some period); if so, the name entry will be freed.  If the ADB
 * is in the overmem condition, the tail and the next to tail entries
 * will be unconditionally removed (unless they have an outstanding fetch).
 * We don't care about a race on 'overmem' at the risk of causing some
 * collateral damage or a small delay in starting cleanup, so we don't bother
 * to lock ADB (if it's not locked).
 *
 * Name bucket must be locked; adb may be locked; no other locks held.
 */
static void
check_stale_name(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
	int victims, max_victims;
	dns_adbname_t *victim, *next_victim;
	bool overmem = isc_mem_isovermem(adb->mctx);
	int scans = 0;

	INSIST(bucket != DNS_ADB_INVALIDBUCKET);

	max_victims = overmem ? 2 : 1;

	/*
	 * We limit the number of scanned entries to 10 (arbitrary choice)
	 * in order to avoid examining too many entries when there are many
	 * tail entries that have fetches (this should be rare, but could
	 * happen).
	 */
	victim = ISC_LIST_TAIL(adb->names[bucket]);
	for (victims = 0; victim != NULL && victims < max_victims && scans < 10;
	     victim = next_victim)
	{
		INSIST(!NAME_DEAD(victim));
		scans++;
		next_victim = ISC_LIST_PREV(victim, plink);
		(void)check_expire_name(&victim, now);
		if (victim == NULL) {
			victims++;
			goto next;
		}

		if (!NAME_FETCH(victim) &&
		    (overmem || victim->last_used + ADB_STALE_MARGIN <= now))
		{
			RUNTIME_CHECK(
				!kill_name(&victim, DNS_EVENT_ADBCANCELED));
			victims++;
		}

	next:
		if (!overmem) {
			break;
		}
	}
}

/*
 * Entry bucket must be locked; adb may be locked; no other locks held.
 */
static bool
check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now) {
	dns_adbentry_t *entry;
	bool result = false;

	INSIST(entryp != NULL && DNS_ADBENTRY_VALID(*entryp));
	entry = *entryp;

	if (entry->refcnt != 0) {
		return (result);
	}

	if (entry->expires == 0 || entry->expires > now) {
		return (result);
	}

	/*
	 * The entry is not in use.  Delete it.
	 */
	*entryp = NULL;
	DP(DEF_LEVEL, "killing entry %p", entry);
	INSIST(ISC_LINK_LINKED(entry, plink));
	result = unlink_entry(adb, entry);
	free_adbentry(adb, &entry);
	if (result) {
		dec_adb_irefcnt(adb);
	}
	return (result);
}

/*
 * ADB must be locked, and no other locks held.
 */
static bool
cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
	dns_adbname_t *name;
	dns_adbname_t *next_name;
	bool result = false;

	DP(CLEAN_LEVEL, "cleaning name bucket %d", bucket);

	LOCK(&adb->namelocks[bucket]);
	if (adb->name_sd[bucket]) {
		UNLOCK(&adb->namelocks[bucket]);
		return (result);
	}

	name = ISC_LIST_HEAD(adb->names[bucket]);
	while (name != NULL) {
		next_name = ISC_LIST_NEXT(name, plink);
		INSIST(!result);
		result = check_expire_namehooks(name, now);
		if (!result) {
			result = check_expire_name(&name, now);
		}
		name = next_name;
	}
	UNLOCK(&adb->namelocks[bucket]);
	return (result);
}

/*
 * ADB must be locked, and no other locks held.
 */
static bool
cleanup_entries(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
	dns_adbentry_t *entry, *next_entry;
	bool result = false;

	DP(CLEAN_LEVEL, "cleaning entry bucket %d", bucket);

	LOCK(&adb->entrylocks[bucket]);
	entry = ISC_LIST_HEAD(adb->entries[bucket]);
	while (entry != NULL) {
		next_entry = ISC_LIST_NEXT(entry, plink);
		INSIST(!result);
		result = check_expire_entry(adb, &entry, now);
		entry = next_entry;
	}
	UNLOCK(&adb->entrylocks[bucket]);
	return (result);
}

static void
destroy(dns_adb_t *adb) {
	adb->magic = 0;

	isc_task_detach(&adb->task);
	if (adb->excl != NULL) {
		isc_task_detach(&adb->excl);
	}

	isc_mutexblock_destroy(adb->entrylocks, adb->nentries);
	isc_mem_put(adb->mctx, adb->entries,
		    sizeof(*adb->entries) * adb->nentries);
	isc_mem_put(adb->mctx, adb->deadentries,
		    sizeof(*adb->deadentries) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entrylocks,
		    sizeof(*adb->entrylocks) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entry_sd,
		    sizeof(*adb->entry_sd) * adb->nentries);
	isc_mem_put(adb->mctx, adb->entry_refcnt,
		    sizeof(*adb->entry_refcnt) * adb->nentries);

	isc_mutexblock_destroy(adb->namelocks, adb->nnames);
	isc_mem_put(adb->mctx, adb->names, sizeof(*adb->names) * adb->nnames);
	isc_mem_put(adb->mctx, adb->deadnames,
		    sizeof(*adb->deadnames) * adb->nnames);
	isc_mem_put(adb->mctx, adb->namelocks,
		    sizeof(*adb->namelocks) * adb->nnames);
	isc_mem_put(adb->mctx, adb->name_sd,
		    sizeof(*adb->name_sd) * adb->nnames);
	isc_mem_put(adb->mctx, adb->name_refcnt,
		    sizeof(*adb->name_refcnt) * adb->nnames);

	isc_mutex_destroy(&adb->reflock);
	isc_mutex_destroy(&adb->lock);
	isc_mutex_destroy(&adb->overmemlock);
	isc_mutex_destroy(&adb->entriescntlock);
	isc_mutex_destroy(&adb->namescntlock);

	isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
}

/*
 * Public functions.
 */

isc_result_t
dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_timermgr_t *timermgr,
	       isc_taskmgr_t *taskmgr, dns_adb_t **newadb) {
	dns_adb_t *adb;
	isc_result_t result;
	unsigned int i;

	REQUIRE(mem != NULL);
	REQUIRE(view != NULL);
	REQUIRE(timermgr != NULL); /* this is actually unused */
	REQUIRE(taskmgr != NULL);
	REQUIRE(newadb != NULL && *newadb == NULL);

	UNUSED(timermgr);

	adb = isc_mem_get(mem, sizeof(dns_adb_t));

	/*
	 * Initialize things here that cannot fail, and especially things
	 * that must be NULL for the error return to work properly.
	 */
	adb->magic = 0;
	adb->erefcnt = 1;
	adb->irefcnt = 0;
	adb->task = NULL;
	adb->excl = NULL;
	adb->mctx = NULL;
	adb->view = view;
	adb->taskmgr = taskmgr;
	adb->next_cleanbucket = 0;
	ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL, 0, NULL,
		       NULL, NULL, NULL, NULL);
	adb->cevent_out = false;
	adb->shutting_down = false;
	ISC_LIST_INIT(adb->whenshutdown);

	adb->nentries = nbuckets[0];
	adb->entriescnt = 0;
	adb->entries = NULL;
	adb->deadentries = NULL;
	adb->entry_sd = NULL;
	adb->entry_refcnt = NULL;
	adb->entrylocks = NULL;
	ISC_EVENT_INIT(&adb->growentries, sizeof(adb->growentries), 0, NULL,
		       DNS_EVENT_ADBGROWENTRIES, grow_entries, adb, adb, NULL,
		       NULL);
	adb->growentries_sent = false;

	adb->quota = 0;
	adb->atr_freq = 0;
	adb->atr_low = 0.0;
	adb->atr_high = 0.0;
	adb->atr_discount = 0.0;

	adb->nnames = nbuckets[0];
	adb->namescnt = 0;
	adb->names = NULL;
	adb->deadnames = NULL;
	adb->name_sd = NULL;
	adb->name_refcnt = NULL;
	adb->namelocks = NULL;
	ISC_EVENT_INIT(&adb->grownames, sizeof(adb->grownames), 0, NULL,
		       DNS_EVENT_ADBGROWNAMES, grow_names, adb, adb, NULL,
		       NULL);
	adb->grownames_sent = false;

	result = isc_taskmgr_excltask(adb->taskmgr, &adb->excl);
	if (result != ISC_R_SUCCESS) {
		DP(DEF_LEVEL,
		   "adb: task-exclusive mode unavailable, "
		   "initializing table sizes to %u\n",
		   nbuckets[11]);
		adb->nentries = nbuckets[11];
		adb->nnames = nbuckets[11];
	}

	isc_mem_attach(mem, &adb->mctx);

	isc_mutex_init(&adb->lock);
	isc_mutex_init(&adb->reflock);
	isc_mutex_init(&adb->overmemlock);
	isc_mutex_init(&adb->entriescntlock);
	isc_mutex_init(&adb->namescntlock);

#define ALLOCENTRY(adb, el)                                                    \
	do {                                                                   \
		(adb)->el = isc_mem_get((adb)->mctx,                           \
					sizeof(*(adb)->el) * (adb)->nentries); \
	} while (0)
	ALLOCENTRY(adb, entries);
	ALLOCENTRY(adb, deadentries);
	ALLOCENTRY(adb, entrylocks);
	ALLOCENTRY(adb, entry_sd);
	ALLOCENTRY(adb, entry_refcnt);
#undef ALLOCENTRY

#define ALLOCNAME(adb, el)                                                   \
	do {                                                                 \
		(adb)->el = isc_mem_get((adb)->mctx,                         \
					sizeof(*(adb)->el) * (adb)->nnames); \
	} while (0)
	ALLOCNAME(adb, names);
	ALLOCNAME(adb, deadnames);
	ALLOCNAME(adb, namelocks);
	ALLOCNAME(adb, name_sd);
	ALLOCNAME(adb, name_refcnt);
#undef ALLOCNAME

	/*
	 * Initialize the bucket locks for names and elements.
	 * May as well initialize the list heads, too.
	 */
	isc_mutexblock_init(adb->namelocks, adb->nnames);

	for (i = 0; i < adb->nnames; i++) {
		ISC_LIST_INIT(adb->names[i]);
		ISC_LIST_INIT(adb->deadnames[i]);
		adb->name_sd[i] = false;
		adb->name_refcnt[i] = 0;
		adb->irefcnt++;
	}
	for (i = 0; i < adb->nentries; i++) {
		ISC_LIST_INIT(adb->entries[i]);
		ISC_LIST_INIT(adb->deadentries[i]);
		adb->entry_sd[i] = false;
		adb->entry_refcnt[i] = 0;
		adb->irefcnt++;
	}
	isc_mutexblock_init(adb->entrylocks, adb->nentries);

	isc_refcount_init(&adb->ahrefcnt, 0);
	isc_refcount_init(&adb->nhrefcnt, 0);

	/*
	 * Allocate an internal task.
	 */
	result = isc_task_create(adb->taskmgr, 0, &adb->task);
	if (result != ISC_R_SUCCESS) {
		goto fail2;
	}

	isc_task_setname(adb->task, "ADB", adb);

	result = isc_stats_create(adb->mctx, &view->adbstats, dns_adbstats_max);
	if (result != ISC_R_SUCCESS) {
		goto fail2;
	}

	set_adbstat(adb, adb->nentries, dns_adbstats_nentries);
	set_adbstat(adb, adb->nnames, dns_adbstats_nnames);

	/*
	 * Normal return.
	 */
	adb->magic = DNS_ADB_MAGIC;
	*newadb = adb;
	return (ISC_R_SUCCESS);

fail2:
	if (adb->task != NULL) {
		isc_task_detach(&adb->task);
	}

	/* clean up entrylocks */
	isc_mutexblock_destroy(adb->entrylocks, adb->nentries);
	isc_mutexblock_destroy(adb->namelocks, adb->nnames);

	if (adb->entries != NULL) {
		isc_mem_put(adb->mctx, adb->entries,
			    sizeof(*adb->entries) * adb->nentries);
	}
	if (adb->deadentries != NULL) {
		isc_mem_put(adb->mctx, adb->deadentries,
			    sizeof(*adb->deadentries) * adb->nentries);
	}
	if (adb->entrylocks != NULL) {
		isc_mem_put(adb->mctx, adb->entrylocks,
			    sizeof(*adb->entrylocks) * adb->nentries);
	}
	if (adb->entry_sd != NULL) {
		isc_mem_put(adb->mctx, adb->entry_sd,
			    sizeof(*adb->entry_sd) * adb->nentries);
	}
	if (adb->entry_refcnt != NULL) {
		isc_mem_put(adb->mctx, adb->entry_refcnt,
			    sizeof(*adb->entry_refcnt) * adb->nentries);
	}
	if (adb->names != NULL) {
		isc_mem_put(adb->mctx, adb->names,
			    sizeof(*adb->names) * adb->nnames);
	}
	if (adb->deadnames != NULL) {
		isc_mem_put(adb->mctx, adb->deadnames,
			    sizeof(*adb->deadnames) * adb->nnames);
	}
	if (adb->namelocks != NULL) {
		isc_mem_put(adb->mctx, adb->namelocks,
			    sizeof(*adb->namelocks) * adb->nnames);
	}
	if (adb->name_sd != NULL) {
		isc_mem_put(adb->mctx, adb->name_sd,
			    sizeof(*adb->name_sd) * adb->nnames);
	}
	if (adb->name_refcnt != NULL) {
		isc_mem_put(adb->mctx, adb->name_refcnt,
			    sizeof(*adb->name_refcnt) * adb->nnames);
	}

	isc_mutex_destroy(&adb->namescntlock);
	isc_mutex_destroy(&adb->entriescntlock);
	isc_mutex_destroy(&adb->overmemlock);
	isc_mutex_destroy(&adb->reflock);
	isc_mutex_destroy(&adb->lock);
	if (adb->excl != NULL) {
		isc_task_detach(&adb->excl);
	}
	isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));

	return (result);
}

void
dns_adb_attach(dns_adb_t *adb, dns_adb_t **adbx) {
	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(adbx != NULL && *adbx == NULL);

	inc_adb_erefcnt(adb);
	*adbx = adb;
}

void
dns_adb_detach(dns_adb_t **adbx) {
	dns_adb_t *adb;
	bool need_exit_check;

	REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx));

	adb = *adbx;
	*adbx = NULL;

	LOCK(&adb->reflock);
	INSIST(adb->erefcnt > 0);
	adb->erefcnt--;
	need_exit_check = (adb->erefcnt == 0 && adb->irefcnt == 0);
	UNLOCK(&adb->reflock);

	if (need_exit_check) {
		LOCK(&adb->lock);
		INSIST(adb->shutting_down);
		check_exit(adb);
		UNLOCK(&adb->lock);
	}
}

void
dns_adb_whenshutdown(dns_adb_t *adb, isc_task_t *task, isc_event_t **eventp) {
	isc_task_t *tclone;
	isc_event_t *event;
	bool zeroirefcnt;

	/*
	 * Send '*eventp' to 'task' when 'adb' has shutdown.
	 */

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(eventp != NULL);

	event = *eventp;
	*eventp = NULL;

	LOCK(&adb->lock);
	LOCK(&adb->reflock);

	zeroirefcnt = (adb->irefcnt == 0);

	if (adb->shutting_down && zeroirefcnt &&
	    isc_refcount_current(&adb->ahrefcnt) == 0)
	{
		/*
		 * We're already shutdown.  Send the event.
		 */
		event->ev_sender = adb;
		isc_task_send(task, &event);
	} else {
		tclone = NULL;
		isc_task_attach(task, &tclone);
		event->ev_sender = tclone;
		ISC_LIST_APPEND(adb->whenshutdown, event, ev_link);
	}

	UNLOCK(&adb->reflock);
	UNLOCK(&adb->lock);
}

static void
shutdown_stage2(isc_task_t *task, isc_event_t *event) {
	dns_adb_t *adb;

	UNUSED(task);

	adb = event->ev_arg;
	INSIST(DNS_ADB_VALID(adb));

	LOCK(&adb->lock);
	INSIST(adb->shutting_down);
	adb->cevent_out = false;
	(void)shutdown_names(adb);
	(void)shutdown_entries(adb);
	if (dec_adb_irefcnt(adb)) {
		check_exit(adb);
	}
	UNLOCK(&adb->lock);
}

void
dns_adb_shutdown(dns_adb_t *adb) {
	isc_event_t *event;

	/*
	 * Shutdown 'adb'.
	 */

	LOCK(&adb->lock);

	if (!adb->shutting_down) {
		adb->shutting_down = true;
		isc_mem_setwater(adb->mctx, water, adb, 0, 0);
		/*
		 * Isolate shutdown_names and shutdown_entries calls.
		 */
		inc_adb_irefcnt(adb);
		ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL,
			       DNS_EVENT_ADBCONTROL, shutdown_stage2, adb, adb,
			       NULL, NULL);
		adb->cevent_out = true;
		event = &adb->cevent;
		isc_task_send(adb->task, &event);
	}

	UNLOCK(&adb->lock);
}

isc_result_t
dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
		   void *arg, const dns_name_t *name, const dns_name_t *qname,
		   dns_rdatatype_t qtype, unsigned int options,
		   isc_stdtime_t now, dns_name_t *target, in_port_t port,
		   unsigned int depth, isc_counter_t *qc,
		   dns_adbfind_t **findp) {
	dns_adbfind_t *find;
	dns_adbname_t *adbname;
	int bucket;
	bool want_event, start_at_zone, alias, have_address;
	isc_result_t result;
	unsigned int wanted_addresses;
	unsigned int wanted_fetches;
	unsigned int query_pending;
	char namebuf[DNS_NAME_FORMATSIZE];

	REQUIRE(DNS_ADB_VALID(adb));
	if (task != NULL) {
		REQUIRE(action != NULL);
	}
	REQUIRE(name != NULL);
	REQUIRE(qname != NULL);
	REQUIRE(findp != NULL && *findp == NULL);
	REQUIRE(target == NULL || dns_name_hasbuffer(target));

	REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0);

	result = ISC_R_UNEXPECTED;
	POST(result);
	wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK);
	wanted_fetches = 0;
	query_pending = 0;
	want_event = false;
	start_at_zone = false;
	alias = false;

	if (now == 0) {
		isc_stdtime_get(&now);
	}

	/*
	 * XXXMLG  Move this comment somewhere else!
	 *
	 * Look up the name in our internal database.
	 *
	 * Possibilities:  Note that these are not always exclusive.
	 *
	 *      No name found.  In this case, allocate a new name header and
	 *      an initial namehook or two.  If any of these allocations
	 *      fail, clean up and return ISC_R_NOMEMORY.
	 *
	 *      Name found, valid addresses present.  Allocate one addrinfo
	 *      structure for each found and append it to the linked list
	 *      of addresses for this header.
	 *
	 *      Name found, queries pending.  In this case, if a task was
	 *      passed in, allocate a job id, attach it to the name's job
	 *      list and remember to tell the caller that there will be
	 *      more info coming later.
	 */

	find = new_adbfind(adb);
	if (find == NULL) {
		return (ISC_R_NOMEMORY);
	}

	find->port = port;

	/*
	 * Remember what types of addresses we are interested in.
	 */
	find->options = options;
	find->flags |= wanted_addresses;
	if (FIND_WANTEVENT(find)) {
		REQUIRE(task != NULL);
	}

	if (isc_log_wouldlog(dns_lctx, DEF_LEVEL)) {
		dns_name_format(name, namebuf, sizeof(namebuf));
	} else {
		namebuf[0] = 0;
	}

	/*
	 * Try to see if we know anything about this name at all.
	 */
	bucket = DNS_ADB_INVALIDBUCKET;
	adbname = find_name_and_lock(adb, name, find->options, &bucket);
	INSIST(bucket != DNS_ADB_INVALIDBUCKET);
	if (adb->name_sd[bucket]) {
		DP(DEF_LEVEL, "dns_adb_createfind: returning "
			      "ISC_R_SHUTTINGDOWN");
		RUNTIME_CHECK(!free_adbfind(adb, &find));
		result = ISC_R_SHUTTINGDOWN;
		goto out;
	}

	/*
	 * Nothing found.  Allocate a new adbname structure for this name.
	 */
	if (adbname == NULL) {
		/*
		 * See if there is any stale name at the end of list, and purge
		 * it if so.
		 */
		check_stale_name(adb, bucket, now);

		adbname = new_adbname(adb, name);
		if (adbname == NULL) {
			RUNTIME_CHECK(!free_adbfind(adb, &find));
			result = ISC_R_NOMEMORY;
			goto out;
		}
		link_name(adb, bucket, adbname);
		if (FIND_HINTOK(find)) {
			adbname->flags |= NAME_HINT_OK;
		}
		if (FIND_GLUEOK(find)) {
			adbname->flags |= NAME_GLUE_OK;
		}
		if (FIND_STARTATZONE(find)) {
			adbname->flags |= NAME_STARTATZONE;
		}
	} else {
		/* Move this name forward in the LRU list */
		ISC_LIST_UNLINK(adb->names[bucket], adbname, plink);
		ISC_LIST_PREPEND(adb->names[bucket], adbname, plink);
	}
	adbname->last_used = now;

	/*
	 * Expire old entries, etc.
	 */
	RUNTIME_CHECK(!check_expire_namehooks(adbname, now));

	/*
	 * Do we know that the name is an alias?
	 */
	if (!EXPIRE_OK(adbname->expire_target, now)) {
		/*
		 * Yes, it is.
		 */
		DP(DEF_LEVEL,
		   "dns_adb_createfind: name %s (%p) is an alias (cached)",
		   namebuf, adbname);
		alias = true;
		goto post_copy;
	}

	/*
	 * Try to populate the name from the database and/or
	 * start fetches.  First try looking for an A record
	 * in the database.
	 */
	if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now) &&
	    WANT_INET(wanted_addresses))
	{
		result = dbfind_name(adbname, now, dns_rdatatype_a);
		if (result == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: found A for name %s (%p) in db",
			   namebuf, adbname);
			goto v6;
		}

		/*
		 * Did we get a CNAME or DNAME?
		 */
		if (result == DNS_R_ALIAS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: name %s (%p) is an alias",
			   namebuf, adbname);
			alias = true;
			goto post_copy;
		}

		/*
		 * If the name doesn't exist at all, don't bother with
		 * v6 queries; they won't work.
		 *
		 * If the name does exist but we didn't get our data, go
		 * ahead and try AAAA.
		 *
		 * If the result is neither of these, try a fetch for A.
		 */
		if (NXDOMAIN_RESULT(result)) {
			goto fetch;
		} else if (NXRRSET_RESULT(result)) {
			goto v6;
		}

		if (!NAME_FETCH_V4(adbname)) {
			wanted_fetches |= DNS_ADBFIND_INET;
		}
	}

v6:
	if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now) &&
	    WANT_INET6(wanted_addresses))
	{
		result = dbfind_name(adbname, now, dns_rdatatype_aaaa);
		if (result == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: found AAAA for name %s (%p)",
			   namebuf, adbname);
			goto fetch;
		}

		/*
		 * Did we get a CNAME or DNAME?
		 */
		if (result == DNS_R_ALIAS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: name %s (%p) is an alias",
			   namebuf, adbname);
			alias = true;
			goto post_copy;
		}

		/*
		 * Listen to negative cache hints, and don't start
		 * another query.
		 */
		if (NCACHE_RESULT(result) || AUTH_NX(result)) {
			goto fetch;
		}

		if (!NAME_FETCH_V6(adbname)) {
			wanted_fetches |= DNS_ADBFIND_INET6;
		}
	}

fetch:
	if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) ||
	    (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname)))
	{
		have_address = true;
	} else {
		have_address = false;
	}
	if (wanted_fetches != 0 && !(FIND_AVOIDFETCHES(find) && have_address) &&
	    !FIND_NOFETCH(find))
	{
		/*
		 * We're missing at least one address family.  Either the
		 * caller hasn't instructed us to avoid fetches, or we don't
		 * know anything about any of the address families that would
		 * be acceptable so we have to launch fetches.
		 */

		if (FIND_STARTATZONE(find)) {
			start_at_zone = true;
		}

		/*
		 * Start V4.
		 */
		if (WANT_INET(wanted_fetches) &&
		    fetch_name(adbname, start_at_zone, depth, qc,
			       dns_rdatatype_a) == ISC_R_SUCCESS)
		{
			DP(DEF_LEVEL,
			   "dns_adb_createfind: "
			   "started A fetch for name %s (%p)",
			   namebuf, adbname);
		}

		/*
		 * Start V6.
		 */
		if (WANT_INET6(wanted_fetches) &&
		    fetch_name(adbname, start_at_zone, depth, qc,
			       dns_rdatatype_aaaa) == ISC_R_SUCCESS)
		{
			DP(DEF_LEVEL,
			   "dns_adb_createfind: "
			   "started AAAA fetch for name %s (%p)",
			   namebuf, adbname);
		}
	}

	/*
	 * Run through the name and copy out the bits we are
	 * interested in.
	 */
	copy_namehook_lists(adb, find, qname, qtype, adbname, now);

post_copy:
	if (NAME_FETCH_V4(adbname)) {
		query_pending |= DNS_ADBFIND_INET;
	}
	if (NAME_FETCH_V6(adbname)) {
		query_pending |= DNS_ADBFIND_INET6;
	}

	/*
	 * Attach to the name's query list if there are queries
	 * already running, and we have been asked to.
	 */
	want_event = true;
	if (!FIND_WANTEVENT(find)) {
		want_event = false;
	}
	if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find)) {
		want_event = false;
	}
	if ((wanted_addresses & query_pending) == 0) {
		want_event = false;
	}
	if (alias) {
		want_event = false;
	}
	if (want_event) {
		find->adbname = adbname;
		find->name_bucket = bucket;
		bool empty = ISC_LIST_EMPTY(adbname->finds);
		ISC_LIST_APPEND(adbname->finds, find, plink);
		find->query_pending = (query_pending & wanted_addresses);
		find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
		find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK);
		DP(DEF_LEVEL,
		   "createfind: attaching find %p to adbname "
		   "%p %d",
		   find, adbname, empty);
	} else {
		/*
		 * Remove the flag so the caller knows there will never
		 * be an event, and set internal flags to fake that
		 * the event was sent and freed, so dns_adb_destroyfind() will
		 * do the right thing.
		 */
		find->query_pending = (query_pending & wanted_addresses);
		find->options &= ~DNS_ADBFIND_WANTEVENT;
		find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED);
		find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
	}

	find->partial_result |= (adbname->partial_result & wanted_addresses);
	if (alias) {
		if (target != NULL) {
			dns_name_copynf(&adbname->target, target);
		}
		result = DNS_R_ALIAS;
	} else {
		result = ISC_R_SUCCESS;
	}

	/*
	 * Copy out error flags from the name structure into the find.
	 */
	find->result_v4 = find_err_map[adbname->fetch_err];
	find->result_v6 = find_err_map[adbname->fetch6_err];

out:
	if (find != NULL) {
		*findp = find;

		if (want_event) {
			isc_task_t *taskp;

			INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0);
			taskp = NULL;
			isc_task_attach(task, &taskp);
			find->event.ev_sender = taskp;
			find->event.ev_action = action;
			find->event.ev_arg = arg;
		}
	}

	UNLOCK(&adb->namelocks[bucket]);

	return (result);
}

void
dns_adb_destroyfind(dns_adbfind_t **findp) {
	dns_adbfind_t *find;
	dns_adbentry_t *entry;
	dns_adbaddrinfo_t *ai;
	int bucket;
	dns_adb_t *adb;
	bool overmem;

	REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp));
	find = *findp;
	*findp = NULL;

	LOCK(&find->lock);

	DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find);

	adb = find->adb;
	REQUIRE(DNS_ADB_VALID(adb));

	REQUIRE(FIND_EVENTFREED(find));

	bucket = find->name_bucket;
	INSIST(bucket == DNS_ADB_INVALIDBUCKET);

	UNLOCK(&find->lock);

	/*
	 * The find doesn't exist on any list, and nothing is locked.
	 * Return the find to the memory pool, and decrement the adb's
	 * reference count.
	 */
	overmem = isc_mem_isovermem(adb->mctx);
	ai = ISC_LIST_HEAD(find->list);
	while (ai != NULL) {
		ISC_LIST_UNLINK(find->list, ai, publink);
		entry = ai->entry;
		ai->entry = NULL;
		INSIST(DNS_ADBENTRY_VALID(entry));
		RUNTIME_CHECK(!dec_entry_refcnt(adb, overmem, entry, true));
		free_adbaddrinfo(adb, &ai);
		ai = ISC_LIST_HEAD(find->list);
	}

	/*
	 * WARNING:  The find is freed with the adb locked.  This is done
	 * to avoid a race condition where we free the find, some other
	 * thread tests to see if it should be destroyed, detects it should
	 * be, destroys it, and then we try to lock it for our check, but the
	 * lock is destroyed.
	 */
	LOCK(&adb->lock);
	if (free_adbfind(adb, &find)) {
		check_exit(adb);
	}
	UNLOCK(&adb->lock);
}

void
dns_adb_cancelfind(dns_adbfind_t *find) {
	isc_event_t *ev;
	isc_task_t *task;
	dns_adb_t *adb;
	int bucket;
	int unlock_bucket;

	LOCK(&find->lock);

	DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find);

	adb = find->adb;
	REQUIRE(DNS_ADB_VALID(adb));

	REQUIRE(!FIND_EVENTFREED(find));
	REQUIRE(FIND_WANTEVENT(find));

	bucket = find->name_bucket;
	if (bucket == DNS_ADB_INVALIDBUCKET) {
		goto cleanup;
	}

	/*
	 * We need to get the adbname's lock to unlink the find.
	 */
	unlock_bucket = bucket;
	violate_locking_hierarchy(&find->lock, &adb->namelocks[unlock_bucket]);
	bucket = find->name_bucket;
	if (bucket != DNS_ADB_INVALIDBUCKET) {
		ISC_LIST_UNLINK(find->adbname->finds, find, plink);
		find->adbname = NULL;
		find->name_bucket = DNS_ADB_INVALIDBUCKET;
	}
	UNLOCK(&adb->namelocks[unlock_bucket]);
	bucket = DNS_ADB_INVALIDBUCKET;
	POST(bucket);

cleanup:

	if (!FIND_EVENTSENT(find)) {
		ev = &find->event;
		task = ev->ev_sender;
		ev->ev_sender = find;
		ev->ev_type = DNS_EVENT_ADBCANCELED;
		ev->ev_destroy = event_free;
		ev->ev_destroy_arg = find;
		find->result_v4 = ISC_R_CANCELED;
		find->result_v6 = ISC_R_CANCELED;

		DP(DEF_LEVEL, "sending event %p to task %p for find %p", ev,
		   task, find);

		isc_task_sendanddetach(&task, (isc_event_t **)&ev);
	}

	UNLOCK(&find->lock);
}

void
dns_adb_dump(dns_adb_t *adb, FILE *f) {
	unsigned int i;
	isc_stdtime_t now;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(f != NULL);

	/*
	 * Lock the adb itself, lock all the name buckets, then lock all
	 * the entry buckets.  This should put the adb into a state where
	 * nothing can change, so we can iterate through everything and
	 * print at our leisure.
	 */

	LOCK(&adb->lock);
	isc_stdtime_get(&now);

	for (i = 0; i < adb->nnames; i++) {
		RUNTIME_CHECK(!cleanup_names(adb, i, now));
	}
	for (i = 0; i < adb->nentries; i++) {
		RUNTIME_CHECK(!cleanup_entries(adb, i, now));
	}

	dump_adb(adb, f, false, now);
	UNLOCK(&adb->lock);
}

static void
dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) {
	if (value == INT_MAX) {
		return;
	}
	fprintf(f, " [%s TTL %d]", legend, (int)(value - now));
}

static void
dump_adb(dns_adb_t *adb, FILE *f, bool debug, isc_stdtime_t now) {
	dns_adbname_t *name;
	dns_adbentry_t *entry;

	fprintf(f, ";\n; Address database dump\n;\n");
	fprintf(f, "; [edns success/4096 timeout/1432 timeout/1232 timeout/"
		   "512 timeout]\n");
	fprintf(f, "; [plain success/timeout]\n;\n");
	if (debug) {
		LOCK(&adb->reflock);
		fprintf(f,
			"; addr %p, erefcnt %u, irefcnt %u, finds out "
			"%" PRIuFAST32 "\n",
			adb, adb->erefcnt, adb->irefcnt,
			isc_refcount_current(&adb->nhrefcnt));
		UNLOCK(&adb->reflock);
	}

/*
 * In TSAN mode we need to lock the locks individually, as TSAN
 * can't handle more than 64 locks locked by one thread.
 * In regular mode we want a consistent dump so we need to
 * lock everything.
 */
#ifndef __SANITIZE_THREAD__
	for (size_t i = 0; i < adb->nnames; i++) {
		LOCK(&adb->namelocks[i]);
	}
	for (size_t i = 0; i < adb->nentries; i++) {
		LOCK(&adb->entrylocks[i]);
	}
#endif /* ifndef __SANITIZE_THREAD__ */

	/*
	 * Dump the names
	 */
	for (size_t i = 0; i < adb->nnames; i++) {
#ifdef __SANITIZE_THREAD__
		LOCK(&adb->namelocks[i]);
#endif /* ifdef __SANITIZE_THREAD__ */
		name = ISC_LIST_HEAD(adb->names[i]);
		if (name == NULL) {
#ifdef __SANITIZE_THREAD__
			UNLOCK(&adb->namelocks[i]);
#endif /* ifdef __SANITIZE_THREAD__ */
			continue;
		}
		if (debug) {
			fprintf(f, "; bucket %zu\n", i);
		}
		for (; name != NULL; name = ISC_LIST_NEXT(name, plink)) {
			if (debug) {
				fprintf(f, "; name %p (flags %08x)\n", name,
					name->flags);
			}
			fprintf(f, "; ");
			print_dns_name(f, &name->name);
			if (dns_name_countlabels(&name->target) > 0) {
				fprintf(f, " alias ");
				print_dns_name(f, &name->target);
			}

			dump_ttl(f, "v4", name->expire_v4, now);
			dump_ttl(f, "v6", name->expire_v6, now);
			dump_ttl(f, "target", name->expire_target, now);

			fprintf(f, " [v4 %s] [v6 %s]",
				errnames[name->fetch_err],
				errnames[name->fetch6_err]);

			fprintf(f, "\n");

			print_namehook_list(f, "v4", adb, &name->v4, debug,
					    now);
			print_namehook_list(f, "v6", adb, &name->v6, debug,
					    now);

			if (debug) {
				print_fetch_list(f, name);
				print_find_list(f, name);
			}
		}
#ifdef __SANITIZE_THREAD__
		UNLOCK(&adb->namelocks[i]);
#endif /* ifdef __SANITIZE_THREAD__ */
	}

	fprintf(f, ";\n; Unassociated entries\n;\n");

	for (size_t i = 0; i < adb->nentries; i++) {
#ifdef __SANITIZE_THREAD__
		LOCK(&adb->entrylocks[i]);
#endif /* ifdef __SANITIZE_THREAD__ */
		entry = ISC_LIST_HEAD(adb->entries[i]);
		while (entry != NULL) {
			if (entry->nh == 0) {
				dump_entry(f, adb, entry, debug, now);
			}
			entry = ISC_LIST_NEXT(entry, plink);
		}
#ifdef __SANITIZE_THREAD__
		UNLOCK(&adb->entrylocks[i]);
#endif /* ifdef __SANITIZE_THREAD__ */
	}

#ifndef __SANITIZE_THREAD__
	/*
	 * Unlock everything
	 */
	for (ssize_t i = adb->nentries - 1; i >= 0; i--) {
		UNLOCK(&adb->entrylocks[i]);
	}
	for (ssize_t i = adb->nnames - 1; i >= 0; i--) {
		UNLOCK(&adb->namelocks[i]);
	}
#endif /* ifndef __SANITIZE_THREAD__ */
}

static void
dump_entry(FILE *f, dns_adb_t *adb, dns_adbentry_t *entry, bool debug,
	   isc_stdtime_t now) {
	char addrbuf[ISC_NETADDR_FORMATSIZE];
	char typebuf[DNS_RDATATYPE_FORMATSIZE];
	isc_netaddr_t netaddr;
	dns_adblameinfo_t *li;

	isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
	isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));

	if (debug) {
		fprintf(f, ";\t%p: refcnt %u\n", entry, entry->refcnt);
	}

	fprintf(f,
		";\t%s [srtt %u] [flags %08x] [edns %u/%u/%u/%u/%u] "
		"[plain %u/%u]",
		addrbuf, entry->srtt, entry->flags, entry->edns, entry->to4096,
		entry->to1432, entry->to1232, entry->to512, entry->plain,
		entry->plainto);
	if (entry->udpsize != 0U) {
		fprintf(f, " [udpsize %u]", entry->udpsize);
	}
	if (entry->cookie != NULL) {
		unsigned int i;
		fprintf(f, " [cookie=");
		for (i = 0; i < entry->cookielen; i++) {
			fprintf(f, "%02x", entry->cookie[i]);
		}
		fprintf(f, "]");
	}
	if (entry->expires != 0) {
		fprintf(f, " [ttl %d]", (int)(entry->expires - now));
	}

	if (adb != NULL && adb->quota != 0 && adb->atr_freq != 0) {
		uint_fast32_t quota = atomic_load_relaxed(&entry->quota);
		fprintf(f, " [atr %0.2f] [quota %" PRIuFAST32 "]", entry->atr,
			quota);
	}

	fprintf(f, "\n");
	for (li = ISC_LIST_HEAD(entry->lameinfo); li != NULL;
	     li = ISC_LIST_NEXT(li, plink))
	{
		fprintf(f, ";\t\t");
		print_dns_name(f, &li->qname);
		dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf));
		fprintf(f, " %s [lame TTL %d]\n", typebuf,
			(int)(li->lame_timer - now));
	}
}

void
dns_adb_dumpfind(dns_adbfind_t *find, FILE *f) {
	char tmp[512];
	const char *tmpp;
	dns_adbaddrinfo_t *ai;
	isc_sockaddr_t *sa;

	/*
	 * Not used currently, in the API Just In Case we
	 * want to dump out the name and/or entries too.
	 */

	LOCK(&find->lock);

	fprintf(f, ";Find %p\n", find);
	fprintf(f, ";\tqpending %08x partial %08x options %08x flags %08x\n",
		find->query_pending, find->partial_result, find->options,
		find->flags);
	fprintf(f, ";\tname_bucket %d, name %p, event sender %p\n",
		find->name_bucket, find->adbname, find->event.ev_sender);

	ai = ISC_LIST_HEAD(find->list);
	if (ai != NULL) {
		fprintf(f, "\tAddresses:\n");
	}
	while (ai != NULL) {
		sa = &ai->sockaddr;
		switch (sa->type.sa.sa_family) {
		case AF_INET:
			tmpp = inet_ntop(AF_INET, &sa->type.sin.sin_addr, tmp,
					 sizeof(tmp));
			break;
		case AF_INET6:
			tmpp = inet_ntop(AF_INET6, &sa->type.sin6.sin6_addr,
					 tmp, sizeof(tmp));
			break;
		default:
			tmpp = "UnkFamily";
		}

		if (tmpp == NULL) {
			tmpp = "BadAddress";
		}

		fprintf(f,
			"\t\tentry %p, flags %08x"
			" srtt %u addr %s\n",
			ai->entry, ai->flags, ai->srtt, tmpp);

		ai = ISC_LIST_NEXT(ai, publink);
	}

	UNLOCK(&find->lock);
}

static void
print_dns_name(FILE *f, const dns_name_t *name) {
	char buf[DNS_NAME_FORMATSIZE];

	INSIST(f != NULL);

	dns_name_format(name, buf, sizeof(buf));
	fprintf(f, "%s", buf);
}

static void
print_namehook_list(FILE *f, const char *legend, dns_adb_t *adb,
		    dns_adbnamehooklist_t *list, bool debug,
		    isc_stdtime_t now) {
	dns_adbnamehook_t *nh;

	for (nh = ISC_LIST_HEAD(*list); nh != NULL;
	     nh = ISC_LIST_NEXT(nh, plink))
	{
		if (debug) {
			fprintf(f, ";\tHook(%s) %p\n", legend, nh);
		}
#ifdef __SANITIZE_THREAD__
		LOCK(&adb->entrylocks[nh->entry->lock_bucket]);
#endif
		dump_entry(f, adb, nh->entry, debug, now);
#ifdef __SANITIZE_THREAD__
		UNLOCK(&adb->entrylocks[nh->entry->lock_bucket]);
#endif
	}
}

static void
print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) {
	fprintf(f, "\t\tFetch(%s): %p -> { fetch %p }\n", type, ft, ft->fetch);
}

static void
print_fetch_list(FILE *f, dns_adbname_t *n) {
	if (NAME_FETCH_A(n)) {
		print_fetch(f, n->fetch_a, "A");
	}
	if (NAME_FETCH_AAAA(n)) {
		print_fetch(f, n->fetch_aaaa, "AAAA");
	}
}

static void
print_find_list(FILE *f, dns_adbname_t *name) {
	dns_adbfind_t *find;

	find = ISC_LIST_HEAD(name->finds);
	while (find != NULL) {
		dns_adb_dumpfind(find, f);
		find = ISC_LIST_NEXT(find, plink);
	}
}

static isc_result_t
dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype) {
	isc_result_t result;
	dns_rdataset_t rdataset;
	dns_adb_t *adb;
	dns_fixedname_t foundname;
	dns_name_t *fname;

	INSIST(DNS_ADBNAME_VALID(adbname));
	adb = adbname->adb;
	INSIST(DNS_ADB_VALID(adb));
	INSIST(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);

	fname = dns_fixedname_initname(&foundname);
	dns_rdataset_init(&rdataset);

	if (rdtype == dns_rdatatype_a) {
		adbname->fetch_err = FIND_ERR_UNEXPECTED;
	} else {
		adbname->fetch6_err = FIND_ERR_UNEXPECTED;
	}

	/*
	 * We need to specify whether to search static-stub zones (if
	 * configured) depending on whether this is a "start at zone" lookup,
	 * i.e., whether it's a "bailiwick" glue.  If it's bailiwick (in which
	 * case NAME_STARTATZONE is set) we need to stop the search at any
	 * matching static-stub zone without looking into the cache to honor
	 * the configuration on which server we should send queries to.
	 */
	result = dns_view_find(adb->view, &adbname->name, rdtype, now,
			       NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0,
			       NAME_HINTOK(adbname),
			       ((adbname->flags & NAME_STARTATZONE) != 0), NULL,
			       NULL, fname, &rdataset, NULL);

	/* XXXVIX this switch statement is too sparse to gen a jump table. */
	switch (result) {
	case DNS_R_GLUE:
	case DNS_R_HINT:
	case ISC_R_SUCCESS:
		/*
		 * Found in the database.  Even if we can't copy out
		 * any information, return success, or else a fetch
		 * will be made, which will only make things worse.
		 */
		if (rdtype == dns_rdatatype_a) {
			adbname->fetch_err = FIND_ERR_SUCCESS;
		} else {
			adbname->fetch6_err = FIND_ERR_SUCCESS;
		}
		result = import_rdataset(adbname, &rdataset, now);
		break;
	case DNS_R_NXDOMAIN:
	case DNS_R_NXRRSET:
		/*
		 * We're authoritative and the data doesn't exist.
		 * Make up a negative cache entry so we don't ask again
		 * for a while.
		 *
		 * XXXRTH  What time should we use?  I'm putting in 30 seconds
		 * for now.
		 */
		if (rdtype == dns_rdatatype_a) {
			adbname->expire_v4 = now + 30;
			DP(NCACHE_LEVEL,
			   "adb name %p: Caching auth negative entry for A",
			   adbname);
			if (result == DNS_R_NXDOMAIN) {
				adbname->fetch_err = FIND_ERR_NXDOMAIN;
			} else {
				adbname->fetch_err = FIND_ERR_NXRRSET;
			}
		} else {
			DP(NCACHE_LEVEL,
			   "adb name %p: Caching auth negative entry for AAAA",
			   adbname);
			adbname->expire_v6 = now + 30;
			if (result == DNS_R_NXDOMAIN) {
				adbname->fetch6_err = FIND_ERR_NXDOMAIN;
			} else {
				adbname->fetch6_err = FIND_ERR_NXRRSET;
			}
		}
		break;
	case DNS_R_NCACHENXDOMAIN:
	case DNS_R_NCACHENXRRSET:
		/*
		 * We found a negative cache entry.  Pull the TTL from it
		 * so we won't ask again for a while.
		 */
		rdataset.ttl = ttlclamp(rdataset.ttl);
		if (rdtype == dns_rdatatype_a) {
			adbname->expire_v4 = rdataset.ttl + now;
			if (result == DNS_R_NCACHENXDOMAIN) {
				adbname->fetch_err = FIND_ERR_NXDOMAIN;
			} else {
				adbname->fetch_err = FIND_ERR_NXRRSET;
			}
			DP(NCACHE_LEVEL,
			   "adb name %p: Caching negative entry for A (ttl %u)",
			   adbname, rdataset.ttl);
		} else {
			DP(NCACHE_LEVEL,
			   "adb name %p: Caching negative entry for AAAA (ttl "
			   "%u)",
			   adbname, rdataset.ttl);
			adbname->expire_v6 = rdataset.ttl + now;
			if (result == DNS_R_NCACHENXDOMAIN) {
				adbname->fetch6_err = FIND_ERR_NXDOMAIN;
			} else {
				adbname->fetch6_err = FIND_ERR_NXRRSET;
			}
		}
		break;
	case DNS_R_CNAME:
	case DNS_R_DNAME:
		/*
		 * Clear the hint and glue flags, so this will match
		 * more often.
		 */
		adbname->flags &= ~(DNS_ADBFIND_GLUEOK | DNS_ADBFIND_HINTOK);

		rdataset.ttl = ttlclamp(rdataset.ttl);
		clean_target(adb, &adbname->target);
		adbname->expire_target = INT_MAX;
		result = set_target(adb, &adbname->name, fname, &rdataset,
				    &adbname->target);
		if (result == ISC_R_SUCCESS) {
			result = DNS_R_ALIAS;
			DP(NCACHE_LEVEL, "adb name %p: caching alias target",
			   adbname);
			adbname->expire_target = rdataset.ttl + now;
		}
		if (rdtype == dns_rdatatype_a) {
			adbname->fetch_err = FIND_ERR_SUCCESS;
		} else {
			adbname->fetch6_err = FIND_ERR_SUCCESS;
		}
		break;
	}

	if (dns_rdataset_isassociated(&rdataset)) {
		dns_rdataset_disassociate(&rdataset);
	}

	return (result);
}

static void
fetch_callback(isc_task_t *task, isc_event_t *ev) {
	dns_fetchevent_t *dev;
	dns_adbname_t *name;
	dns_adb_t *adb;
	dns_adbfetch_t *fetch;
	int bucket;
	isc_eventtype_t ev_status;
	isc_stdtime_t now;
	isc_result_t result;
	unsigned int address_type;
	bool want_check_exit = false;

	UNUSED(task);

	INSIST(ev->ev_type == DNS_EVENT_FETCHDONE);
	dev = (dns_fetchevent_t *)ev;
	name = ev->ev_arg;
	INSIST(DNS_ADBNAME_VALID(name));
	adb = name->adb;
	INSIST(DNS_ADB_VALID(adb));

	bucket = name->lock_bucket;
	LOCK(&adb->namelocks[bucket]);

	INSIST(NAME_FETCH_A(name) || NAME_FETCH_AAAA(name));
	address_type = 0;
	if (NAME_FETCH_A(name) && (name->fetch_a->fetch == dev->fetch)) {
		address_type = DNS_ADBFIND_INET;
		fetch = name->fetch_a;
		name->fetch_a = NULL;
	} else if (NAME_FETCH_AAAA(name) &&
		   (name->fetch_aaaa->fetch == dev->fetch))
	{
		address_type = DNS_ADBFIND_INET6;
		fetch = name->fetch_aaaa;
		name->fetch_aaaa = NULL;
	} else {
		fetch = NULL;
	}

	INSIST(address_type != 0 && fetch != NULL);

	dns_resolver_destroyfetch(&fetch->fetch);
	dev->fetch = NULL;

	ev_status = DNS_EVENT_ADBNOMOREADDRESSES;

	/*
	 * Cleanup things we don't care about.
	 */
	if (dev->node != NULL) {
		dns_db_detachnode(dev->db, &dev->node);
	}
	if (dev->db != NULL) {
		dns_db_detach(&dev->db);
	}

	/*
	 * If this name is marked as dead, clean up, throwing away
	 * potentially good data.
	 */
	if (NAME_DEAD(name)) {
		free_adbfetch(adb, &fetch);
		isc_event_free(&ev);

		want_check_exit = kill_name(&name, DNS_EVENT_ADBCANCELED);

		UNLOCK(&adb->namelocks[bucket]);

		if (want_check_exit) {
			LOCK(&adb->lock);
			check_exit(adb);
			UNLOCK(&adb->lock);
		}

		return;
	}

	isc_stdtime_get(&now);

	/*
	 * If we got a negative cache response, remember it.
	 */
	if (NCACHE_RESULT(dev->result)) {
		dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
		if (address_type == DNS_ADBFIND_INET) {
			DP(NCACHE_LEVEL,
			   "adb fetch name %p: "
			   "caching negative entry for A (ttl %u)",
			   name, dev->rdataset->ttl);
			name->expire_v4 = ISC_MIN(name->expire_v4,
						  dev->rdataset->ttl + now);
			if (dev->result == DNS_R_NCACHENXDOMAIN) {
				name->fetch_err = FIND_ERR_NXDOMAIN;
			} else {
				name->fetch_err = FIND_ERR_NXRRSET;
			}
			inc_stats(adb, dns_resstatscounter_gluefetchv4fail);
		} else {
			DP(NCACHE_LEVEL,
			   "adb fetch name %p: "
			   "caching negative entry for AAAA (ttl %u)",
			   name, dev->rdataset->ttl);
			name->expire_v6 = ISC_MIN(name->expire_v6,
						  dev->rdataset->ttl + now);
			if (dev->result == DNS_R_NCACHENXDOMAIN) {
				name->fetch6_err = FIND_ERR_NXDOMAIN;
			} else {
				name->fetch6_err = FIND_ERR_NXRRSET;
			}
			inc_stats(adb, dns_resstatscounter_gluefetchv6fail);
		}
		goto out;
	}

	/*
	 * Handle CNAME/DNAME.
	 */
	if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) {
		dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
		clean_target(adb, &name->target);
		name->expire_target = INT_MAX;
		result = set_target(adb, &name->name,
				    dns_fixedname_name(&dev->foundname),
				    dev->rdataset, &name->target);
		if (result == ISC_R_SUCCESS) {
			DP(NCACHE_LEVEL,
			   "adb fetch name %p: caching alias target", name);
			name->expire_target = dev->rdataset->ttl + now;
		}
		goto check_result;
	}

	/*
	 * Did we get back junk?  If so, and there are no more fetches
	 * sitting out there, tell all the finds about it.
	 */
	if (dev->result != ISC_R_SUCCESS) {
		char buf[DNS_NAME_FORMATSIZE];

		dns_name_format(&name->name, buf, sizeof(buf));
		DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s", buf,
		   address_type == DNS_ADBFIND_INET ? "A" : "AAAA",
		   dns_result_totext(dev->result));
		/*
		 * Don't record a failure unless this is the initial
		 * fetch of a chain.
		 */
		if (fetch->depth > 1) {
			goto out;
		}
		/* XXXMLG Don't pound on bad servers. */
		if (address_type == DNS_ADBFIND_INET) {
			name->expire_v4 = ISC_MIN(name->expire_v4, now + 10);
			name->fetch_err = FIND_ERR_FAILURE;
			inc_stats(adb, dns_resstatscounter_gluefetchv4fail);
		} else {
			name->expire_v6 = ISC_MIN(name->expire_v6, now + 10);
			name->fetch6_err = FIND_ERR_FAILURE;
			inc_stats(adb, dns_resstatscounter_gluefetchv6fail);
		}
		goto out;
	}

	/*
	 * We got something potentially useful.
	 */
	result = import_rdataset(name, &fetch->rdataset, now);

check_result:
	if (result == ISC_R_SUCCESS) {
		ev_status = DNS_EVENT_ADBMOREADDRESSES;
		if (address_type == DNS_ADBFIND_INET) {
			name->fetch_err = FIND_ERR_SUCCESS;
		} else {
			name->fetch6_err = FIND_ERR_SUCCESS;
		}
	}

out:
	free_adbfetch(adb, &fetch);
	isc_event_free(&ev);

	clean_finds_at_name(name, ev_status, address_type);

	UNLOCK(&adb->namelocks[bucket]);
}

static isc_result_t
fetch_name(dns_adbname_t *adbname, bool start_at_zone, unsigned int depth,
	   isc_counter_t *qc, dns_rdatatype_t type) {
	isc_result_t result;
	dns_adbfetch_t *fetch = NULL;
	dns_adb_t *adb;
	dns_fixedname_t fixed;
	dns_name_t *name;
	dns_rdataset_t rdataset;
	dns_rdataset_t *nameservers;
	unsigned int options;

	INSIST(DNS_ADBNAME_VALID(adbname));
	adb = adbname->adb;
	INSIST(DNS_ADB_VALID(adb));

	INSIST((type == dns_rdatatype_a && !NAME_FETCH_V4(adbname)) ||
	       (type == dns_rdatatype_aaaa && !NAME_FETCH_V6(adbname)));

	adbname->fetch_err = FIND_ERR_NOTFOUND;

	name = NULL;
	nameservers = NULL;
	dns_rdataset_init(&rdataset);

	options = DNS_FETCHOPT_NOVALIDATE;
	if (start_at_zone) {
		DP(ENTER_LEVEL, "fetch_name: starting at zone for name %p",
		   adbname);
		name = dns_fixedname_initname(&fixed);
		result = dns_view_findzonecut(adb->view, &adbname->name, name,
					      NULL, 0, 0, true, false,
					      &rdataset, NULL);
		if (result != ISC_R_SUCCESS && result != DNS_R_HINT) {
			goto cleanup;
		}
		nameservers = &rdataset;
		options |= DNS_FETCHOPT_UNSHARED;
	}

	fetch = new_adbfetch(adb);
	if (fetch == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}
	fetch->depth = depth;

	/*
	 * We're not minimizing this query, as nothing user-related should
	 * be leaked here.
	 * However, if we'd ever want to change it we'd have to modify
	 * createfetch to find deepest cached name when we're providing
	 * domain and nameservers.
	 */
	result = dns_resolver_createfetch(
		adb->view->resolver, &adbname->name, type, name, nameservers,
		NULL, NULL, 0, options, depth, qc, adb->task, fetch_callback,
		adbname, &fetch->rdataset, NULL, &fetch->fetch);
	if (result != ISC_R_SUCCESS) {
		DP(ENTER_LEVEL, "fetch_name: createfetch failed with %s",
		   isc_result_totext(result));
		goto cleanup;
	}

	if (type == dns_rdatatype_a) {
		adbname->fetch_a = fetch;
		inc_stats(adb, dns_resstatscounter_gluefetchv4);
	} else {
		adbname->fetch_aaaa = fetch;
		inc_stats(adb, dns_resstatscounter_gluefetchv6);
	}
	fetch = NULL; /* Keep us from cleaning this up below. */

cleanup:
	if (fetch != NULL) {
		free_adbfetch(adb, &fetch);
	}
	if (dns_rdataset_isassociated(&rdataset)) {
		dns_rdataset_disassociate(&rdataset);
	}

	return (result);
}

/*
 * XXXMLG Needs to take a find argument and an address info, no zone or adb,
 * since these can be extracted from the find itself.
 */
isc_result_t
dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
		 const dns_name_t *qname, dns_rdatatype_t qtype,
		 isc_stdtime_t expire_time) {
	dns_adblameinfo_t *li;
	int bucket;
	isc_result_t result = ISC_R_SUCCESS;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));
	REQUIRE(qname != NULL);

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);
	li = ISC_LIST_HEAD(addr->entry->lameinfo);
	while (li != NULL &&
	       (li->qtype != qtype || !dns_name_equal(qname, &li->qname)))
	{
		li = ISC_LIST_NEXT(li, plink);
	}
	if (li != NULL) {
		if (expire_time > li->lame_timer) {
			li->lame_timer = expire_time;
		}
		goto unlock;
	}
	li = new_adblameinfo(adb, qname, qtype);
	if (li == NULL) {
		result = ISC_R_NOMEMORY;
		goto unlock;
	}

	li->lame_timer = expire_time;

	ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink);
unlock:
	UNLOCK(&adb->entrylocks[bucket]);

	return (result);
}

void
dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int rtt,
		   unsigned int factor) {
	int bucket;
	isc_stdtime_t now = 0;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));
	REQUIRE(factor <= 10);

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	if (addr->entry->expires == 0 || factor == DNS_ADB_RTTADJAGE) {
		isc_stdtime_get(&now);
	}
	adjustsrtt(addr, rtt, factor, now);

	UNLOCK(&adb->entrylocks[bucket]);
}

void
dns_adb_agesrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr, isc_stdtime_t now) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	adjustsrtt(addr, 0, DNS_ADB_RTTADJAGE, now);

	UNLOCK(&adb->entrylocks[bucket]);
}

static void
adjustsrtt(dns_adbaddrinfo_t *addr, unsigned int rtt, unsigned int factor,
	   isc_stdtime_t now) {
	uint64_t new_srtt;

	if (factor == DNS_ADB_RTTADJAGE) {
		if (addr->entry->lastage != now) {
			new_srtt = addr->entry->srtt;
			new_srtt <<= 9;
			new_srtt -= addr->entry->srtt;
			new_srtt >>= 9;
			addr->entry->lastage = now;
		} else {
			new_srtt = addr->entry->srtt;
		}
	} else {
		new_srtt = ((uint64_t)addr->entry->srtt / 10 * factor) +
			   ((uint64_t)rtt / 10 * (10 - factor));
	}

	addr->entry->srtt = (unsigned int)new_srtt;
	addr->srtt = (unsigned int)new_srtt;

	if (addr->entry->expires == 0) {
		addr->entry->expires = now + ADB_ENTRY_WINDOW;
	}
}

void
dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int bits,
		    unsigned int mask) {
	int bucket;
	isc_stdtime_t now;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	REQUIRE((bits & ENTRY_IS_DEAD) == 0);
	REQUIRE((mask & ENTRY_IS_DEAD) == 0);

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask);
	if (addr->entry->expires == 0) {
		isc_stdtime_get(&now);
		addr->entry->expires = now + ADB_ENTRY_WINDOW;
	}

	/*
	 * Note that we do not update the other bits in addr->flags with
	 * the most recent values from addr->entry->flags.
	 */
	addr->flags = (addr->flags & ~mask) | (bits & mask);

	UNLOCK(&adb->entrylocks[bucket]);
}

/*
 * The polynomial backoff curve (10000 / ((10 + n) / 10)^(3/2)) <0..99> drops
 * fairly aggressively at first, then slows down and tails off at around 2-3%.
 *
 * These will be used to make quota adjustments.
 */
static int quota_adj[] = {
	10000, 8668, 7607, 6747, 6037, 5443, 4941, 4512, 4141, 3818, 3536,
	3286,  3065, 2867, 2690, 2530, 2385, 2254, 2134, 2025, 1925, 1832,
	1747,  1668, 1595, 1527, 1464, 1405, 1350, 1298, 1250, 1205, 1162,
	1121,  1083, 1048, 1014, 981,  922,  894,  868,	 843,  820,  797,
	775,   755,  735,  716,	 698,  680,  664,  648,	 632,  618,  603,
	590,   577,  564,  552,	 540,  529,  518,  507,	 497,  487,  477,
	468,   459,  450,  442,	 434,  426,  418,  411,	 404,  397,  390,
	383,   377,  370,  364,	 358,  353,  347,  342,	 336,  331,  326,
	321,   316,  312,  307,	 303,  298,  294,  290,	 286,  282,  278
};

#define QUOTA_ADJ_SIZE (sizeof(quota_adj) / sizeof(quota_adj[0]))

/*
 * Caller must hold adbentry lock
 */
static void
maybe_adjust_quota(dns_adb_t *adb, dns_adbaddrinfo_t *addr, bool timeout) {
	double tr;

	UNUSED(adb);

	if (adb->quota == 0 || adb->atr_freq == 0) {
		return;
	}

	if (timeout) {
		addr->entry->timeouts++;
	}

	if (addr->entry->completed++ <= adb->atr_freq) {
		return;
	}

	/*
	 * Calculate an exponential rolling average of the timeout ratio
	 *
	 * XXX: Integer arithmetic might be better than floating point
	 */
	tr = (double)addr->entry->timeouts / addr->entry->completed;
	addr->entry->timeouts = addr->entry->completed = 0;
	INSIST(addr->entry->atr >= 0.0);
	INSIST(addr->entry->atr <= 1.0);
	INSIST(adb->atr_discount >= 0.0);
	INSIST(adb->atr_discount <= 1.0);
	addr->entry->atr *= 1.0 - adb->atr_discount;
	addr->entry->atr += tr * adb->atr_discount;
	addr->entry->atr = ISC_CLAMP(addr->entry->atr, 0.0, 1.0);

	if (addr->entry->atr < adb->atr_low && addr->entry->mode > 0) {
		uint_fast32_t new_quota =
			adb->quota * quota_adj[--addr->entry->mode] / 10000;
		atomic_store_release(&addr->entry->quota,
				     ISC_MAX(1, new_quota));
		log_quota(addr->entry,
			  "atr %0.2f, quota increased to %" PRIuFAST32,
			  addr->entry->atr, new_quota);
	} else if (addr->entry->atr > adb->atr_high &&
		   addr->entry->mode < (QUOTA_ADJ_SIZE - 1))
	{
		uint_fast32_t new_quota =
			adb->quota * quota_adj[++addr->entry->mode] / 10000;
		atomic_store_release(&addr->entry->quota,
				     ISC_MAX(1, new_quota));
		log_quota(addr->entry,
			  "atr %0.2f, quota decreased to %" PRIuFAST32,
			  addr->entry->atr, new_quota);
	}
}

#define EDNSTOS 3U
bool
dns_adb_noedns(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	int bucket;
	bool noedns = false;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	if (addr->entry->edns == 0U &&
	    (addr->entry->plain > EDNSTOS || addr->entry->to4096 > EDNSTOS))
	{
		if (((addr->entry->plain + addr->entry->to4096) & 0x3f) != 0) {
			noedns = true;
		} else {
			/*
			 * Increment plain so we don't get stuck.
			 */
			addr->entry->plain++;
			if (addr->entry->plain == 0xff) {
				addr->entry->edns >>= 1;
				addr->entry->to4096 >>= 1;
				addr->entry->to1432 >>= 1;
				addr->entry->to1232 >>= 1;
				addr->entry->to512 >>= 1;
				addr->entry->plain >>= 1;
				addr->entry->plainto >>= 1;
			}
		}
	}
	UNLOCK(&adb->entrylocks[bucket]);
	return (noedns);
}

void
dns_adb_plainresponse(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	maybe_adjust_quota(adb, addr, false);

	addr->entry->plain++;
	if (addr->entry->plain == 0xff) {
		addr->entry->edns >>= 1;
		addr->entry->to4096 >>= 1;
		addr->entry->to1432 >>= 1;
		addr->entry->to1232 >>= 1;
		addr->entry->to512 >>= 1;
		addr->entry->plain >>= 1;
		addr->entry->plainto >>= 1;
	}
	UNLOCK(&adb->entrylocks[bucket]);
}

void
dns_adb_timeout(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	maybe_adjust_quota(adb, addr, true);

	/*
	 * If we have not had a successful query then clear all
	 * edns timeout information.
	 */
	if (addr->entry->edns == 0 && addr->entry->plain == 0) {
		addr->entry->to512 = 0;
		addr->entry->to1232 = 0;
		addr->entry->to1432 = 0;
		addr->entry->to4096 = 0;
	} else {
		addr->entry->to512 >>= 1;
		addr->entry->to1232 >>= 1;
		addr->entry->to1432 >>= 1;
		addr->entry->to4096 >>= 1;
	}

	addr->entry->plainto++;
	if (addr->entry->plainto == 0xff) {
		addr->entry->edns >>= 1;
		addr->entry->plain >>= 1;
		addr->entry->plainto >>= 1;
	}
	UNLOCK(&adb->entrylocks[bucket]);
}

void
dns_adb_ednsto(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int size) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	maybe_adjust_quota(adb, addr, true);

	if (size <= 512U) {
		if (addr->entry->to512 <= EDNSTOS) {
			addr->entry->to512++;
			addr->entry->to1232++;
			addr->entry->to1432++;
			addr->entry->to4096++;
		}
	} else if (size <= 1232U) {
		if (addr->entry->to1232 <= EDNSTOS) {
			addr->entry->to1232++;
			addr->entry->to1432++;
			addr->entry->to4096++;
		}
	} else if (size <= 1432U) {
		if (addr->entry->to1432 <= EDNSTOS) {
			addr->entry->to1432++;
			addr->entry->to4096++;
		}
	} else {
		if (addr->entry->to4096 <= EDNSTOS) {
			addr->entry->to4096++;
		}
	}

	if (addr->entry->to4096 == 0xff) {
		addr->entry->edns >>= 1;
		addr->entry->to4096 >>= 1;
		addr->entry->to1432 >>= 1;
		addr->entry->to1232 >>= 1;
		addr->entry->to512 >>= 1;
		addr->entry->plain >>= 1;
		addr->entry->plainto >>= 1;
	}
	UNLOCK(&adb->entrylocks[bucket]);
}

void
dns_adb_setudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr, unsigned int size) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);
	if (size < 512U) {
		size = 512U;
	}
	if (size > addr->entry->udpsize) {
		addr->entry->udpsize = size;
	}

	maybe_adjust_quota(adb, addr, false);

	addr->entry->edns++;
	if (addr->entry->edns == 0xff) {
		addr->entry->edns >>= 1;
		addr->entry->to4096 >>= 1;
		addr->entry->to1432 >>= 1;
		addr->entry->to1232 >>= 1;
		addr->entry->to512 >>= 1;
		addr->entry->plain >>= 1;
		addr->entry->plainto >>= 1;
	}
	UNLOCK(&adb->entrylocks[bucket]);
}

unsigned int
dns_adb_getudpsize(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	int bucket;
	unsigned int size;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);
	size = addr->entry->udpsize;
	UNLOCK(&adb->entrylocks[bucket]);

	return (size);
}

unsigned int
dns_adb_probesize(dns_adb_t *adb, dns_adbaddrinfo_t *addr, int lookups) {
	int bucket;
	unsigned int size;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);
	if (addr->entry->to1232 > EDNSTOS || lookups >= 2) {
		size = 512;
	} else if (addr->entry->to1432 > EDNSTOS || lookups >= 1) {
		size = 1232;
	} else if (addr->entry->to4096 > EDNSTOS) {
		size = 1432;
	} else {
		size = 4096;
	}
	/*
	 * Don't shrink probe size below what we have seen due to multiple
	 * lookups.
	 */
	if (lookups > 0 && size < addr->entry->udpsize &&
	    addr->entry->udpsize < 4096)
	{
		size = addr->entry->udpsize;
	}
	UNLOCK(&adb->entrylocks[bucket]);

	return (size);
}

void
dns_adb_setcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
		  const unsigned char *cookie, size_t len) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	if (addr->entry->cookie != NULL &&
	    (cookie == NULL || len != addr->entry->cookielen))
	{
		isc_mem_put(adb->mctx, addr->entry->cookie,
			    addr->entry->cookielen);
		addr->entry->cookie = NULL;
		addr->entry->cookielen = 0;
	}

	if (addr->entry->cookie == NULL && cookie != NULL && len != 0U) {
		addr->entry->cookie = isc_mem_get(adb->mctx, len);
		addr->entry->cookielen = (uint16_t)len;
	}

	if (addr->entry->cookie != NULL) {
		memmove(addr->entry->cookie, cookie, len);
	}
	UNLOCK(&adb->entrylocks[bucket]);
}

size_t
dns_adb_getcookie(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
		  unsigned char *cookie, size_t len) {
	int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);
	if (cookie != NULL && addr->entry->cookie != NULL &&
	    len >= addr->entry->cookielen)
	{
		memmove(cookie, addr->entry->cookie, addr->entry->cookielen);
		len = addr->entry->cookielen;
	} else {
		len = 0;
	}
	UNLOCK(&adb->entrylocks[bucket]);

	return (len);
}

isc_result_t
dns_adb_findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *sa,
		     dns_adbaddrinfo_t **addrp, isc_stdtime_t now) {
	int bucket;
	dns_adbentry_t *entry;
	dns_adbaddrinfo_t *addr;
	isc_result_t result;
	in_port_t port;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(addrp != NULL && *addrp == NULL);

	UNUSED(now);

	result = ISC_R_SUCCESS;
	bucket = DNS_ADB_INVALIDBUCKET;
	entry = find_entry_and_lock(adb, sa, &bucket, now);
	INSIST(bucket != DNS_ADB_INVALIDBUCKET);
	if (adb->entry_sd[bucket]) {
		result = ISC_R_SHUTTINGDOWN;
		goto unlock;
	}
	if (entry == NULL) {
		/*
		 * We don't know anything about this address.
		 */
		entry = new_adbentry(adb);
		if (entry == NULL) {
			result = ISC_R_NOMEMORY;
			goto unlock;
		}
		entry->sockaddr = *sa;
		link_entry(adb, bucket, entry);
		DP(ENTER_LEVEL, "findaddrinfo: new entry %p", entry);
	} else {
		DP(ENTER_LEVEL, "findaddrinfo: found entry %p", entry);
	}

	port = isc_sockaddr_getport(sa);
	addr = new_adbaddrinfo(adb, entry, port);
	if (addr == NULL) {
		result = ISC_R_NOMEMORY;
	} else {
		inc_entry_refcnt(adb, entry, false);
		*addrp = addr;
	}

unlock:
	UNLOCK(&adb->entrylocks[bucket]);

	return (result);
}

void
dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) {
	dns_adbaddrinfo_t *addr;
	dns_adbentry_t *entry;
	int bucket;
	isc_stdtime_t now;
	bool want_check_exit = false;
	bool overmem;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(addrp != NULL);
	addr = *addrp;
	*addrp = NULL;
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));
	entry = addr->entry;
	REQUIRE(DNS_ADBENTRY_VALID(entry));

	overmem = isc_mem_isovermem(adb->mctx);

	bucket = addr->entry->lock_bucket;
	LOCK(&adb->entrylocks[bucket]);

	if (entry->expires == 0) {
		isc_stdtime_get(&now);
		entry->expires = now + ADB_ENTRY_WINDOW;
	}

	want_check_exit = dec_entry_refcnt(adb, overmem, entry, false);

	UNLOCK(&adb->entrylocks[bucket]);

	addr->entry = NULL;
	free_adbaddrinfo(adb, &addr);

	if (want_check_exit) {
		LOCK(&adb->lock);
		check_exit(adb);
		UNLOCK(&adb->lock);
	}
}

void
dns_adb_flush(dns_adb_t *adb) {
	unsigned int i;

	INSIST(DNS_ADB_VALID(adb));

	LOCK(&adb->lock);

	/*
	 * Call our cleanup routines.
	 */
	for (i = 0; i < adb->nnames; i++) {
		RUNTIME_CHECK(!cleanup_names(adb, i, INT_MAX));
	}
	for (i = 0; i < adb->nentries; i++) {
		RUNTIME_CHECK(!cleanup_entries(adb, i, INT_MAX));
	}

#ifdef DUMP_ADB_AFTER_CLEANING
	dump_adb(adb, stdout, true, INT_MAX);
#endif /* ifdef DUMP_ADB_AFTER_CLEANING */

	UNLOCK(&adb->lock);
}

void
dns_adb_flushname(dns_adb_t *adb, const dns_name_t *name) {
	dns_adbname_t *adbname;
	dns_adbname_t *nextname;
	unsigned int bucket;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(name != NULL);

	LOCK(&adb->lock);
	bucket = dns_name_hash(name, false) % adb->nnames;
	LOCK(&adb->namelocks[bucket]);
	adbname = ISC_LIST_HEAD(adb->names[bucket]);
	while (adbname != NULL) {
		nextname = ISC_LIST_NEXT(adbname, plink);
		if (!NAME_DEAD(adbname) && dns_name_equal(name, &adbname->name))
		{
			RUNTIME_CHECK(
				!kill_name(&adbname, DNS_EVENT_ADBCANCELED));
		}
		adbname = nextname;
	}
	UNLOCK(&adb->namelocks[bucket]);
	UNLOCK(&adb->lock);
}

void
dns_adb_flushnames(dns_adb_t *adb, const dns_name_t *name) {
	dns_adbname_t *adbname, *nextname;
	unsigned int i;

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(name != NULL);

	LOCK(&adb->lock);
	for (i = 0; i < adb->nnames; i++) {
		LOCK(&adb->namelocks[i]);
		adbname = ISC_LIST_HEAD(adb->names[i]);
		while (adbname != NULL) {
			bool ret;
			nextname = ISC_LIST_NEXT(adbname, plink);
			if (!NAME_DEAD(adbname) &&
			    dns_name_issubdomain(&adbname->name, name))
			{
				ret = kill_name(&adbname,
						DNS_EVENT_ADBCANCELED);
				RUNTIME_CHECK(!ret);
			}
			adbname = nextname;
		}
		UNLOCK(&adb->namelocks[i]);
	}
	UNLOCK(&adb->lock);
}

static void
water(void *arg, int mark) {
	/*
	 * We're going to change the way to handle overmem condition: use
	 * isc_mem_isovermem() instead of storing the state via this callback,
	 * since the latter way tends to cause race conditions.
	 * To minimize the change, and in case we re-enable the callback
	 * approach, however, keep this function at the moment.
	 */

	dns_adb_t *adb = arg;
	bool overmem = (mark == ISC_MEM_HIWATER);

	REQUIRE(DNS_ADB_VALID(adb));

	DP(ISC_LOG_DEBUG(1), "adb reached %s water mark",
	   overmem ? "high" : "low");
}

void
dns_adb_setadbsize(dns_adb_t *adb, size_t size) {
	size_t hiwater, lowater;

	INSIST(DNS_ADB_VALID(adb));

	if (size != 0U && size < DNS_ADB_MINADBSIZE) {
		size = DNS_ADB_MINADBSIZE;
	}

	hiwater = size - (size >> 3); /* Approximately 7/8ths. */
	lowater = size - (size >> 2); /* Approximately 3/4ths. */

	if (size == 0U || hiwater == 0U || lowater == 0U) {
		isc_mem_setwater(adb->mctx, water, adb, 0, 0);
	} else {
		isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater);
	}
}

void
dns_adb_setquota(dns_adb_t *adb, uint32_t quota, uint32_t freq, double low,
		 double high, double discount) {
	REQUIRE(DNS_ADB_VALID(adb));

	adb->quota = quota;
	adb->atr_freq = freq;
	adb->atr_low = low;
	adb->atr_high = high;
	adb->atr_discount = discount;
}

bool
dns_adbentry_overquota(dns_adbentry_t *entry) {
	REQUIRE(DNS_ADBENTRY_VALID(entry));

	uint_fast32_t quota = atomic_load_relaxed(&entry->quota);
	uint_fast32_t active = atomic_load_acquire(&entry->active);

	return (quota != 0 && active >= quota);
}

void
dns_adb_beginudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	INSIST(atomic_fetch_add_relaxed(&addr->entry->active, 1) != UINT32_MAX);
}

void
dns_adb_endudpfetch(dns_adb_t *adb, dns_adbaddrinfo_t *addr) {
	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(DNS_ADBADDRINFO_VALID(addr));

	INSIST(atomic_fetch_sub_release(&addr->entry->active, 1) != 0);
}