Update to bind-9.10.5-P3, which appears to have been the last ISC version.

We only use this tree to build dig and nslookup. Our previous version
predated edns0 support in those tools, and we want that.  This is the worst
code I've looked at in years, with layers and layers of spaghetti abstraction
clearly unfit for reuse, but then reused anyways, and the old ones remain
behind.  So this is a 8MB diff.
florian, sthen, and otto tried this merge before but failed.

1 files changed, 587 insertions, 169 deletions

diff --git a/usr.sbin/bind/lib/dns/cache.c b/usr.sbin/bind/lib/dns/cache.c
index ecefaf9193e..69b35d1a970 100644
--- a/usr.sbin/bind/lib/dns/cache.c
+++ b/usr.sbin/bind/lib/dns/cache.c
@@ -1,8 +1,8 @@
 /*
- * Copyright (C) 2004-2006  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2004-2009, 2011-2013, 2015, 2016  Internet Systems Consortium, Inc. ("ISC")
  * Copyright (C) 1999-2003  Internet Software Consortium.
  *
- * Permission to use, copy, modify, and distribute this software for any
+ * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
@@ -15,17 +15,22 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $ISC: cache.c,v 1.57.18.16 2006/08/01 01:06:48 marka Exp $ */
+/* $Id: cache.c,v 1.7 2019/12/16 16:16:24 deraadt Exp $ */
 
 /*! \file */
 
 #include <config.h>
 
+#include <isc/json.h>
 #include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/string.h>
+#include <isc/stats.h>
 #include <isc/task.h>
 #include <isc/time.h>
 #include <isc/timer.h>
 #include <isc/util.h>
+#include <isc/xml.h>
 
 #include <dns/cache.h>
 #include <dns/db.h>
@@ -38,20 +43,23 @@
 #include <dns/rdataset.h>
 #include <dns/rdatasetiter.h>
 #include <dns/result.h>
+#include <dns/stats.h>
+
+#include "rbtdb.h"
 
 #define CACHE_MAGIC		ISC_MAGIC('$', '$', '$', '$')
 #define VALID_CACHE(cache)	ISC_MAGIC_VALID(cache, CACHE_MAGIC)
 
-/*! 
+/*!
  * Control incremental cleaning.
  * DNS_CACHE_MINSIZE is how many bytes is the floor for dns_cache_setcachesize().
  * See also DNS_CACHE_CLEANERINCREMENT
  */
-#define DNS_CACHE_MINSIZE 		2097152	/*%< Bytes.  2097152 = 2 MB */
-/*! 
+#define DNS_CACHE_MINSIZE	2097152U /*%< Bytes.  2097152 = 2 MB */
+/*!
  * Control incremental cleaning.
  * CLEANERINCREMENT is how many nodes are examined in one pass.
- * See also DNS_CACHE_MINSIZE 
+ * See also DNS_CACHE_MINSIZE
  */
 #define DNS_CACHE_CLEANERINCREMENT	1000U	/*%< Number of nodes. */
 
@@ -60,7 +68,7 @@
  ***/
 
 /*
- * A cache_cleaner_t encapsulsates the state of the periodic
+ * A cache_cleaner_t encapsulates the state of the periodic
  * cache cleaning.
  */
 
@@ -69,7 +77,7 @@ typedef struct cache_cleaner cache_cleaner_t;
 typedef enum {
 	cleaner_s_idle,	/*%< Waiting for cleaning-interval to expire. */
 	cleaner_s_busy,	/*%< Currently cleaning. */
-	cleaner_s_done  /*%< Freed enough memory after being overmem. */
+	cleaner_s_done	/*%< Freed enough memory after being overmem. */
 } cleaner_state_t;
 
 /*
@@ -95,19 +103,19 @@ struct cache_cleaner {
 	 */
 
 	dns_cache_t	*cache;
-	isc_task_t 	*task;
+	isc_task_t	*task;
 	unsigned int	cleaning_interval; /*% The cleaning-interval from
 					      named.conf, in seconds. */
-	isc_timer_t 	*cleaning_timer;
+	isc_timer_t	*cleaning_timer;
 	isc_event_t	*resched_event;	/*% Sent by cleaner task to
 					   itself to reschedule */
 	isc_event_t	*overmem_event;
 
 	dns_dbiterator_t *iterator;
-	unsigned int 	 increment;	/*% Number of names to
+	unsigned int	increment;	/*% Number of names to
 					   clean in one increment */
-	cleaner_state_t  state;		/*% Idle/Busy. */
-	isc_boolean_t	 overmem;	/*% The cache is in an overmem state. */
+	cleaner_state_t	state;		/*% Idle/Busy. */
+	isc_boolean_t	overmem;	/*% The cache is in an overmem state. */
 	isc_boolean_t	 replaceiterator;
 };
 
@@ -120,7 +128,9 @@ struct dns_cache {
 	unsigned int		magic;
 	isc_mutex_t		lock;
 	isc_mutex_t		filelock;
-	isc_mem_t		*mctx;
+	isc_mem_t		*mctx;		/* Main cache memory */
+	isc_mem_t		*hmctx;		/* Heap memory */
+	char			*name;
 
 	/* Locked by 'lock'. */
 	int			references;
@@ -131,9 +141,11 @@ struct dns_cache {
 	char			*db_type;
 	int			db_argc;
 	char			**db_argv;
+	size_t			size;
+	isc_stats_t		*stats;
 
 	/* Locked by 'filelock'. */
-	char *			filename;
+	char			*filename;
 	/* Access to the on-disk cache file is also locked by 'filelock'. */
 };
 
@@ -157,79 +169,6 @@ cleaner_shutdown_action(isc_task_t *task, isc_event_t *event);
 static void
 overmem_cleaning_action(isc_task_t *task, isc_event_t *event);
 
-/*%
- * Work out how many nodes can be cleaned in the time between two
- * requests to the nameserver.  Smooth the resulting number and use
- * it as a estimate for the number of nodes to be cleaned in the next
- * iteration.
- */
-static void
-adjust_increment(cache_cleaner_t *cleaner, unsigned int remaining,
-		 isc_time_t *start)
-{
-	isc_time_t end;
-	isc_uint64_t usecs;
-	isc_uint64_t new;
-	unsigned int pps = dns_pps;
-	unsigned int interval;
-	unsigned int names;
-	
-	/*
-	 * Tune for minumum of 100 packets per second (pps).
-	 */
-	if (pps < 100)
-		pps = 100;
-
-	isc_time_now(&end);
-
-	interval = 1000000 / pps; /* Interval between packets in usecs. */
-	if (interval == 0)
-		interval = 1;
-
-	INSIST(cleaner->increment >= remaining);
-	names = cleaner->increment - remaining;
-	usecs = isc_time_microdiff(&end, start);
-
-	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
-		      ISC_LOG_DEBUG(1), "adjust_increment interval=%u "
-		      "names=%u usec=%" ISC_PLATFORM_QUADFORMAT "u",
-		      interval, names, usecs);
-	
-	if (usecs == 0) {
-		/*
-		 * If we cleaned all the nodes in unmeasurable time
-		 * double the number of nodes to be cleaned next time.
-		 */
-		if (names == cleaner->increment) {
-			cleaner->increment *= 2;
-			if (cleaner->increment > DNS_CACHE_CLEANERINCREMENT)
-				cleaner->increment = DNS_CACHE_CLEANERINCREMENT;
-			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
-				      DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1),
-				      "%p:new cleaner->increment = %u\n",
-				      cleaner, cleaner->increment);
-		}
-		return;
-	}
-
-	new = (names * interval);
-	new /= (usecs * 2);
-	if (new == 0)
-		new = 1;
-
-	/* Smooth */
-	new = (new + cleaner->increment * 7) / 8;
-
-	if (new > DNS_CACHE_CLEANERINCREMENT)
-		new = DNS_CACHE_CLEANERINCREMENT;
-
-	cleaner->increment = (unsigned int)new;
-
-	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE,
-		      ISC_LOG_DEBUG(1), "%p:new cleaner->increment = %u\n",
-		      cleaner, cleaner->increment);
-}
-
 static inline isc_result_t
 cache_create_db(dns_cache_t *cache, dns_db_t **db) {
 	return (dns_db_create(cache->mctx, cache->db_type, dns_rootname,
@@ -238,25 +177,59 @@ cache_create_db(dns_cache_t *cache, dns_db_t **db) {
 }
 
 isc_result_t
-dns_cache_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
+dns_cache_create(isc_mem_t *cmctx, isc_taskmgr_t *taskmgr,
 		 isc_timermgr_t *timermgr, dns_rdataclass_t rdclass,
 		 const char *db_type, unsigned int db_argc, char **db_argv,
 		 dns_cache_t **cachep)
 {
+	return (dns_cache_create3(cmctx, cmctx, taskmgr, timermgr, rdclass, "",
+				  db_type, db_argc, db_argv, cachep));
+}
+
+isc_result_t
+dns_cache_create2(isc_mem_t *cmctx, isc_taskmgr_t *taskmgr,
+		  isc_timermgr_t *timermgr, dns_rdataclass_t rdclass,
+		  const char *cachename, const char *db_type,
+		  unsigned int db_argc, char **db_argv, dns_cache_t **cachep)
+{
+	return (dns_cache_create3(cmctx, cmctx, taskmgr, timermgr, rdclass,
+				  cachename, db_type, db_argc, db_argv,
+				  cachep));
+}
+
+isc_result_t
+dns_cache_create3(isc_mem_t *cmctx, isc_mem_t *hmctx, isc_taskmgr_t *taskmgr,
+		  isc_timermgr_t *timermgr, dns_rdataclass_t rdclass,
+		  const char *cachename, const char *db_type,
+		  unsigned int db_argc, char **db_argv, dns_cache_t **cachep)
+{
 	isc_result_t result;
 	dns_cache_t *cache;
-	int i;
+	int i, extra = 0;
+	isc_task_t *dbtask;
 
 	REQUIRE(cachep != NULL);
 	REQUIRE(*cachep == NULL);
-	REQUIRE(mctx != NULL);
+	REQUIRE(cmctx != NULL);
+	REQUIRE(hmctx != NULL);
+	REQUIRE(cachename != NULL);
 
-	cache = isc_mem_get(mctx, sizeof(*cache));
+	cache = isc_mem_get(cmctx, sizeof(*cache));
 	if (cache == NULL)
 		return (ISC_R_NOMEMORY);
 
-	cache->mctx = NULL;
-	isc_mem_attach(mctx, &cache->mctx);
+	cache->mctx = cache->hmctx = NULL;
+	isc_mem_attach(cmctx, &cache->mctx);
+	isc_mem_attach(hmctx, &cache->hmctx);
+
+	cache->name = NULL;
+	if (cachename != NULL) {
+		cache->name = isc_mem_strdup(cmctx, cachename);
+		if (cache->name == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto cleanup_mem;
+		}
+	}
 
 	result = isc_mutex_init(&cache->lock);
 	if (result != ISC_R_SUCCESS)
@@ -270,26 +243,44 @@ dns_cache_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 	cache->live_tasks = 0;
 	cache->rdclass = rdclass;
 
-	cache->db_type = isc_mem_strdup(mctx, db_type);
+	cache->stats = NULL;
+	result = isc_stats_create(cmctx, &cache->stats,
+				  dns_cachestatscounter_max);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup_filelock;
+
+	cache->db_type = isc_mem_strdup(cmctx, db_type);
 	if (cache->db_type == NULL) {
 		result = ISC_R_NOMEMORY;
-		goto cleanup_filelock;
+		goto cleanup_stats;
 	}
 
-	cache->db_argc = db_argc;
-	if (cache->db_argc == 0)
-		cache->db_argv = NULL;
-	else {
-		cache->db_argv = isc_mem_get(mctx,
+	/*
+	 * For databases of type "rbt" we pass hmctx to dns_db_create()
+	 * via cache->db_argv, followed by the rest of the arguments in
+	 * db_argv (of which there really shouldn't be any).
+	 */
+	if (strcmp(cache->db_type, "rbt") == 0)
+		extra = 1;
+
+	cache->db_argc = db_argc + extra;
+	cache->db_argv = NULL;
+
+	if (cache->db_argc != 0) {
+		cache->db_argv = isc_mem_get(cmctx,
 					     cache->db_argc * sizeof(char *));
 		if (cache->db_argv == NULL) {
 			result = ISC_R_NOMEMORY;
 			goto cleanup_dbtype;
 		}
+
 		for (i = 0; i < cache->db_argc; i++)
 			cache->db_argv[i] = NULL;
-		for (i = 0; i < cache->db_argc; i++) {
-			cache->db_argv[i] = isc_mem_strdup(mctx, db_argv[i]);
+
+		cache->db_argv[0] = (char *) hmctx;
+		for (i = extra; i < cache->db_argc; i++) {
+			cache->db_argv[i] = isc_mem_strdup(cmctx,
+							   db_argv[i - extra]);
 			if (cache->db_argv[i] == NULL) {
 				result = ISC_R_NOMEMORY;
 				goto cleanup_dbargv;
@@ -297,46 +288,74 @@ dns_cache_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 		}
 	}
 
+	/*
+	 * Create the database
+	 */
 	cache->db = NULL;
 	result = cache_create_db(cache, &cache->db);
 	if (result != ISC_R_SUCCESS)
 		goto cleanup_dbargv;
+	if (taskmgr != NULL) {
+		dbtask = NULL;
+		result = isc_task_create(taskmgr, 1, &dbtask);
+		if (result != ISC_R_SUCCESS)
+			goto cleanup_db;
+		dns_db_settask(cache->db, dbtask);
+		isc_task_detach(&dbtask);
+	}
 
 	cache->filename = NULL;
 
 	cache->magic = CACHE_MAGIC;
 
-	result = cache_cleaner_init(cache, taskmgr, timermgr, &cache->cleaner);
+	/*
+	 * RBT-type cache DB has its own mechanism of cache cleaning and doesn't
+	 * need the control of the generic cleaner.
+	 */
+	if (strcmp(db_type, "rbt") == 0)
+		result = cache_cleaner_init(cache, NULL, NULL, &cache->cleaner);
+	else {
+		result = cache_cleaner_init(cache, taskmgr, timermgr,
+					    &cache->cleaner);
+	}
 	if (result != ISC_R_SUCCESS)
 		goto cleanup_db;
 
+	result = dns_db_setcachestats(cache->db, cache->stats);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup_db;
+
+
 	*cachep = cache;
 	return (ISC_R_SUCCESS);
 
  cleanup_db:
 	dns_db_detach(&cache->db);
  cleanup_dbargv:
-	for (i = 0; i < cache->db_argc; i++)
+	for (i = extra; i < cache->db_argc; i++)
 		if (cache->db_argv[i] != NULL)
-			isc_mem_free(mctx, cache->db_argv[i]);
+			isc_mem_free(cmctx, cache->db_argv[i]);
 	if (cache->db_argv != NULL)
-		isc_mem_put(mctx, cache->db_argv,
+		isc_mem_put(cmctx, cache->db_argv,
 			    cache->db_argc * sizeof(char *));
  cleanup_dbtype:
-	isc_mem_free(mctx, cache->db_type);
+	isc_mem_free(cmctx, cache->db_type);
  cleanup_filelock:
 	DESTROYLOCK(&cache->filelock);
+ cleanup_stats:
+	isc_stats_detach(&cache->stats);
  cleanup_lock:
 	DESTROYLOCK(&cache->lock);
  cleanup_mem:
-	isc_mem_put(mctx, cache, sizeof(*cache));
-	isc_mem_detach(&mctx);
+	if (cache->name != NULL)
+		isc_mem_free(cmctx, cache->name);
+	isc_mem_detach(&cache->hmctx);
+	isc_mem_putanddetach(&cache->mctx, cache, sizeof(*cache));
 	return (result);
 }
 
 static void
 cache_free(dns_cache_t *cache) {
-	isc_mem_t *mctx;
 	int i;
 
 	REQUIRE(VALID_CACHE(cache));
@@ -367,7 +386,14 @@ cache_free(dns_cache_t *cache) {
 		dns_db_detach(&cache->db);
 
 	if (cache->db_argv != NULL) {
-		for (i = 0; i < cache->db_argc; i++)
+		/*
+		 * We don't free db_argv[0] in "rbt" cache databases
+		 * as it's a pointer to hmctx
+		 */
+		int extra = 0;
+		if (strcmp(cache->db_type, "rbt") == 0)
+			extra = 1;
+		for (i = extra; i < cache->db_argc; i++)
 			if (cache->db_argv[i] != NULL)
 				isc_mem_free(cache->mctx, cache->db_argv[i]);
 		isc_mem_put(cache->mctx, cache->db_argv,
@@ -377,12 +403,18 @@ cache_free(dns_cache_t *cache) {
 	if (cache->db_type != NULL)
 		isc_mem_free(cache->mctx, cache->db_type);
 
+	if (cache->name != NULL)
+		isc_mem_free(cache->mctx, cache->name);
+
+	if (cache->stats != NULL)
+		isc_stats_detach(&cache->stats);
+
 	DESTROYLOCK(&cache->lock);
 	DESTROYLOCK(&cache->filelock);
+
 	cache->magic = 0;
-	mctx = cache->mctx;
-	isc_mem_put(cache->mctx, cache, sizeof(*cache));
-	isc_mem_detach(&mctx);
+	isc_mem_detach(&cache->hmctx);
+	isc_mem_putanddetach(&cache->mctx, cache, sizeof(*cache));
 }
 
 
@@ -506,8 +538,8 @@ dns_cache_dump(dns_cache_t *cache) {
 	result = dns_master_dump(cache->mctx, cache->db, NULL,
 				 &dns_master_style_cache, cache->filename);
 	UNLOCK(&cache->filelock);
-
 	return (result);
+
 }
 
 void
@@ -537,7 +569,7 @@ dns_cache_setcleaninginterval(dns_cache_t *cache, unsigned int t) {
 					 isc_timertype_ticker,
 					 NULL, &interval, ISC_FALSE);
 	}
-	if (result != ISC_R_SUCCESS)	
+	if (result != ISC_R_SUCCESS)
 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
 			      DNS_LOGMODULE_CACHE, ISC_LOG_WARNING,
 			      "could not set cache cleaning interval: %s",
@@ -547,6 +579,26 @@ dns_cache_setcleaninginterval(dns_cache_t *cache, unsigned int t) {
 	UNLOCK(&cache->lock);
 }
 
+unsigned int
+dns_cache_getcleaninginterval(dns_cache_t *cache) {
+	unsigned int t;
+
+	REQUIRE(VALID_CACHE(cache));
+
+	LOCK(&cache->lock);
+	t = cache->cleaner.cleaning_interval;
+	UNLOCK(&cache->lock);
+
+	return (t);
+}
+
+const char *
+dns_cache_getname(dns_cache_t *cache) {
+	REQUIRE(VALID_CACHE(cache));
+
+	return (cache->name);
+}
+
 /*
  * Initialize the cache cleaner object at *cleaner.
  * Space for the object must be allocated by the caller.
@@ -573,6 +625,7 @@ cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr,
 	cleaner->cleaning_timer = NULL;
 	cleaner->resched_event = NULL;
 	cleaner->overmem_event = NULL;
+	cleaner->cleaning_interval = 0; /* Initially turned off. */
 
 	result = dns_db_createiterator(cleaner->cache->db, ISC_FALSE,
 				       &cleaner->iterator);
@@ -601,10 +654,8 @@ cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr,
 			goto cleanup;
 		}
 
-		cleaner->cleaning_interval = 0; /* Initially turned off. */
 		result = isc_timer_create(timermgr, isc_timertype_inactive,
-					   NULL, NULL,
-					   cleaner->task,
+					   NULL, NULL, cleaner->task,
 					   cleaning_timer_action, cleaner,
 					   &cleaner->cleaning_timer);
 		if (result != ISC_R_SUCCESS) {
@@ -624,7 +675,7 @@ cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr,
 			result = ISC_R_NOMEMORY;
 			goto cleanup;
 		}
-		
+
 		cleaner->overmem_event =
 			isc_event_allocate(cache->mctx, cleaner,
 					   DNS_EVENT_CACHEOVERMEM,
@@ -662,7 +713,7 @@ begin_cleaning(cache_cleaner_t *cleaner) {
 
 	/*
 	 * Create an iterator, if it does not already exist, and
-         * position it at the beginning of the cache.
+	 * position it at the beginning of the cache.
 	 */
 	if (cleaner->iterator == NULL)
 		result = dns_db_createiterator(cleaner->cache->db, ISC_FALSE,
@@ -701,7 +752,7 @@ begin_cleaning(cache_cleaner_t *cleaner) {
 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
 			      DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1),
 			      "begin cache cleaning, mem inuse %lu",
-		            (unsigned long)isc_mem_inuse(cleaner->cache->mctx));
+			    (unsigned long)isc_mem_inuse(cleaner->cache->mctx));
 		cleaner->state = cleaner_s_busy;
 		isc_task_send(cleaner->task, &cleaner->resched_event);
 	}
@@ -761,7 +812,7 @@ static void
 overmem_cleaning_action(isc_task_t *task, isc_event_t *event) {
 	cache_cleaner_t *cleaner = event->ev_arg;
 	isc_boolean_t want_cleaning = ISC_FALSE;
-	
+
 	UNUSED(task);
 
 	INSIST(task == cleaner->task);
@@ -848,7 +899,6 @@ incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
 				 "cache cleaner: dns_dbiterator_current() "
 				 "failed: %s", dns_result_totext(result));
 
-			adjust_increment(cleaner, n_names, &start);
 			end_cleaning(cleaner, event);
 			return;
 		}
@@ -892,14 +942,11 @@ incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
 				}
 			}
 
-			adjust_increment(cleaner, n_names, &start);
 			end_cleaning(cleaner, event);
 			return;
 		}
 	}
 
-	adjust_increment(cleaner, 0U, &start);
-
 	/*
 	 * We have successfully performed a cleaning increment but have
 	 * not gone through the entire cache.  Free the iterator locks
@@ -929,7 +976,7 @@ dns_cache_clean(dns_cache_t *cache, isc_stdtime_t now) {
 
 	REQUIRE(VALID_CACHE(cache));
 
-	result = dns_db_createiterator(cache->db, ISC_FALSE, &iterator);
+	result = dns_db_createiterator(cache->db, 0, &iterator);
 	if (result != ISC_R_SUCCESS)
 		return result;
 
@@ -980,9 +1027,12 @@ water(void *arg, int mark) {
 	REQUIRE(VALID_CACHE(cache));
 
 	LOCK(&cache->cleaner.lock);
-	
-	dns_db_overmem(cache->db, overmem);
-	cache->cleaner.overmem = overmem;
+
+	if (overmem != cache->cleaner.overmem) {
+		dns_db_overmem(cache->db, overmem);
+		cache->cleaner.overmem = overmem;
+		isc_mem_waterack(cache->mctx, mark);
+	}
 
 	if (cache->cleaner.overmem_event != NULL)
 		isc_task_send(cache->cleaner.task,
@@ -992,19 +1042,22 @@ water(void *arg, int mark) {
 }
 
 void
-dns_cache_setcachesize(dns_cache_t *cache, isc_uint32_t size) {
-	isc_uint32_t lowater;
-	isc_uint32_t hiwater;
+dns_cache_setcachesize(dns_cache_t *cache, size_t size) {
+	size_t hiwater, lowater;
 
 	REQUIRE(VALID_CACHE(cache));
 
 	/*
-	 * Impose a minumum cache size; pathological things happen if there
+	 * Impose a minimum cache size; pathological things happen if there
 	 * is too little room.
 	 */
-	if (size != 0 && size < DNS_CACHE_MINSIZE)
+	if (size != 0U && size < DNS_CACHE_MINSIZE)
 		size = DNS_CACHE_MINSIZE;
 
+	LOCK(&cache->lock);
+	cache->size = size;
+	UNLOCK(&cache->lock);
+
 	hiwater = size - (size >> 3);	/* Approximately 7/8ths. */
 	lowater = size - (size >> 2);	/* Approximately 3/4ths. */
 
@@ -1015,7 +1068,7 @@ dns_cache_setcachesize(dns_cache_t *cache, isc_uint32_t size) {
 	 * water().
 	 */
 
-	if (size == 0 || hiwater == 0 || lowater == 0)
+	if (size == 0U || hiwater == 0U || lowater == 0U)
 		/*
 		 * Disable cache memory limiting.
 		 */
@@ -1028,6 +1081,19 @@ dns_cache_setcachesize(dns_cache_t *cache, isc_uint32_t size) {
 		isc_mem_setwater(cache->mctx, water, cache, hiwater, lowater);
 }
 
+size_t
+dns_cache_getcachesize(dns_cache_t *cache) {
+	size_t size;
+
+	REQUIRE(VALID_CACHE(cache));
+
+	LOCK(&cache->lock);
+	size = cache->size;
+	UNLOCK(&cache->lock);
+
+	return (size);
+}
+
 /*
  * The cleaner task is shutting down; do the necessary cleanup.
  */
@@ -1073,58 +1139,54 @@ cleaner_shutdown_action(isc_task_t *task, isc_event_t *event) {
 
 isc_result_t
 dns_cache_flush(dns_cache_t *cache) {
-	dns_db_t *db = NULL;
+	dns_db_t *db = NULL, *olddb;
+	dns_dbiterator_t *dbiterator = NULL, *olddbiterator = NULL;
 	isc_result_t result;
 
 	result = cache_create_db(cache, &db);
 	if (result != ISC_R_SUCCESS)
 		return (result);
 
+	result = dns_db_createiterator(db, ISC_FALSE, &dbiterator);
+	if (result != ISC_R_SUCCESS) {
+		dns_db_detach(&db);
+		return (result);
+	}
+
 	LOCK(&cache->lock);
 	LOCK(&cache->cleaner.lock);
 	if (cache->cleaner.state == cleaner_s_idle) {
-		if (cache->cleaner.iterator != NULL)
-			dns_dbiterator_destroy(&cache->cleaner.iterator);
-		(void) dns_db_createiterator(db, ISC_FALSE,
-					     &cache->cleaner.iterator);
+		olddbiterator = cache->cleaner.iterator;
+		cache->cleaner.iterator = dbiterator;
+		dbiterator = NULL;
 	} else {
 		if (cache->cleaner.state == cleaner_s_busy)
 			cache->cleaner.state = cleaner_s_done;
 		cache->cleaner.replaceiterator = ISC_TRUE;
 	}
-	dns_db_detach(&cache->db);
+	olddb = cache->db;
 	cache->db = db;
+	dns_db_setcachestats(cache->db, cache->stats);
 	UNLOCK(&cache->cleaner.lock);
 	UNLOCK(&cache->lock);
 
+	if (dbiterator != NULL)
+		dns_dbiterator_destroy(&dbiterator);
+	if (olddbiterator != NULL)
+		dns_dbiterator_destroy(&olddbiterator);
+	dns_db_detach(&olddb);
+
 	return (ISC_R_SUCCESS);
 }
 
-isc_result_t
-dns_cache_flushname(dns_cache_t *cache, dns_name_t *name) {
+static isc_result_t
+clearnode(dns_db_t *db, dns_dbnode_t *node) {
 	isc_result_t result;
 	dns_rdatasetiter_t *iter = NULL;
-	dns_dbnode_t *node = NULL;
-	dns_db_t *db = NULL;
-	
-	LOCK(&cache->lock);
-	if (cache->db != NULL)
-		dns_db_attach(cache->db, &db);
-	UNLOCK(&cache->lock);
-	if (db == NULL)
-		return (ISC_R_SUCCESS);
-	result = dns_db_findnode(cache->db, name, ISC_FALSE, &node);
-	if (result == ISC_R_NOTFOUND) {
-		result = ISC_R_SUCCESS;
-		goto cleanup_db;
-	}
-	if (result != ISC_R_SUCCESS)
-		goto cleanup_db;
 
-	result = dns_db_allrdatasets(cache->db, node, NULL,
-				     (isc_stdtime_t)0, &iter);
+	result = dns_db_allrdatasets(db, node, NULL, (isc_stdtime_t)0, &iter);
 	if (result != ISC_R_SUCCESS)
-		goto cleanup_node;
+		return (result);
 
 	for (result = dns_rdatasetiter_first(iter);
 	     result == ISC_R_SUCCESS;
@@ -1134,21 +1196,377 @@ dns_cache_flushname(dns_cache_t *cache, dns_name_t *name) {
 		dns_rdataset_init(&rdataset);
 
 		dns_rdatasetiter_current(iter, &rdataset);
-		result = dns_db_deleterdataset(cache->db, node, NULL,
+		result = dns_db_deleterdataset(db, node, NULL,
 					       rdataset.type, rdataset.covers);
 		dns_rdataset_disassociate(&rdataset);
 		if (result != ISC_R_SUCCESS && result != DNS_R_UNCHANGED)
 			break;
 	}
+
 	if (result == ISC_R_NOMORE)
 		result = ISC_R_SUCCESS;
 
 	dns_rdatasetiter_destroy(&iter);
+	return (result);
+}
+
+static isc_result_t
+cleartree(dns_db_t *db, dns_name_t *name) {
+	isc_result_t result, answer = ISC_R_SUCCESS;
+	dns_dbiterator_t *iter = NULL;
+	dns_dbnode_t *node = NULL, *top = NULL;
+	dns_fixedname_t fnodename;
+	dns_name_t *nodename;
+
+	/*
+	 * Create the node if it doesn't exist so dns_dbiterator_seek()
+	 * can find it.  We will continue even if this fails.
+	 */
+	(void)dns_db_findnode(db, name, ISC_TRUE, &top);
+
+	dns_fixedname_init(&fnodename);
+	nodename = dns_fixedname_name(&fnodename);
+
+	result = dns_db_createiterator(db, 0, &iter);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
 
- cleanup_node:
-	dns_db_detachnode(cache->db, &node);
+	result = dns_dbiterator_seek(iter, name);
+	if (result == DNS_R_PARTIALMATCH)
+		result = dns_dbiterator_next(iter);
+	if (result != ISC_R_SUCCESS)
+		goto cleanup;
+
+	while (result == ISC_R_SUCCESS) {
+		result = dns_dbiterator_current(iter, &node, nodename);
+		if (result == DNS_R_NEWORIGIN)
+			result = ISC_R_SUCCESS;
+		if (result != ISC_R_SUCCESS)
+			goto cleanup;
+		/*
+		 * Are we done?
+		 */
+		if (! dns_name_issubdomain(nodename, name))
+			goto cleanup;
+
+		/*
+		 * If clearnode fails record and move onto the next node.
+		 */
+		result = clearnode(db, node);
+		if (result != ISC_R_SUCCESS && answer == ISC_R_SUCCESS)
+			answer = result;
+		dns_db_detachnode(db, &node);
+		result = dns_dbiterator_next(iter);
+	}
+
+ cleanup:
+	if (result == ISC_R_NOMORE || result == ISC_R_NOTFOUND)
+		result = ISC_R_SUCCESS;
+	if (result != ISC_R_SUCCESS && answer == ISC_R_SUCCESS)
+		answer = result;
+	if (node != NULL)
+		dns_db_detachnode(db, &node);
+	if (iter != NULL)
+		dns_dbiterator_destroy(&iter);
+	if (top != NULL)
+		dns_db_detachnode(db, &top);
+
+	return (answer);
+}
+
+isc_result_t
+dns_cache_flushname(dns_cache_t *cache, dns_name_t *name) {
+	return (dns_cache_flushnode(cache, name, ISC_FALSE));
+}
+
+isc_result_t
+dns_cache_flushnode(dns_cache_t *cache, dns_name_t *name,
+		    isc_boolean_t tree)
+{
+	isc_result_t result;
+	dns_dbnode_t *node = NULL;
+	dns_db_t *db = NULL;
+
+	if (tree && dns_name_equal(name, dns_rootname))
+		return (dns_cache_flush(cache));
+
+	LOCK(&cache->lock);
+	if (cache->db != NULL)
+		dns_db_attach(cache->db, &db);
+	UNLOCK(&cache->lock);
+	if (db == NULL)
+		return (ISC_R_SUCCESS);
+
+	if (tree) {
+		result = cleartree(cache->db, name);
+	} else {
+		result = dns_db_findnode(cache->db, name, ISC_FALSE, &node);
+		if (result == ISC_R_NOTFOUND) {
+			result = ISC_R_SUCCESS;
+			goto cleanup_db;
+		}
+		if (result != ISC_R_SUCCESS)
+			goto cleanup_db;
+		result = clearnode(cache->db, node);
+		dns_db_detachnode(cache->db, &node);
+	}
 
  cleanup_db:
 	dns_db_detach(&db);
 	return (result);
 }
+
+isc_stats_t *
+dns_cache_getstats(dns_cache_t *cache) {
+	REQUIRE(VALID_CACHE(cache));
+	return (cache->stats);
+}
+
+void
+dns_cache_updatestats(dns_cache_t *cache, isc_result_t result) {
+	REQUIRE(VALID_CACHE(cache));
+	if (cache->stats == NULL)
+		return;
+
+	switch (result) {
+	case ISC_R_SUCCESS:
+	case DNS_R_NCACHENXDOMAIN:
+	case DNS_R_NCACHENXRRSET:
+	case DNS_R_CNAME:
+	case DNS_R_DNAME:
+	case DNS_R_GLUE:
+	case DNS_R_ZONECUT:
+		isc_stats_increment(cache->stats,
+				    dns_cachestatscounter_queryhits);
+		break;
+	default:
+		isc_stats_increment(cache->stats,
+				    dns_cachestatscounter_querymisses);
+	}
+}
+
+/*
+ * XXX: Much of the following code has been copied in from statschannel.c.
+ * We should refactor this into a generic function in stats.c that can be
+ * called from both places.
+ */
+typedef struct
+cache_dumparg {
+	isc_statsformat_t	type;
+	void			*arg;		/* type dependent argument */
+	int			ncounters;	/* for general statistics */
+	int			*counterindices; /* for general statistics */
+	isc_uint64_t		*countervalues;	 /* for general statistics */
+	isc_result_t		result;
+} cache_dumparg_t;
+
+static void
+getcounter(isc_statscounter_t counter, isc_uint64_t val, void *arg) {
+	cache_dumparg_t *dumparg = arg;
+
+	REQUIRE(counter < dumparg->ncounters);
+	dumparg->countervalues[counter] = val;
+}
+
+static void
+getcounters(isc_stats_t *stats, isc_statsformat_t type, int ncounters,
+	    int *indices, isc_uint64_t *values)
+{
+	cache_dumparg_t dumparg;
+
+	memset(values, 0, sizeof(values[0]) * ncounters);
+
+	dumparg.type = type;
+	dumparg.ncounters = ncounters;
+	dumparg.counterindices = indices;
+	dumparg.countervalues = values;
+
+	isc_stats_dump(stats, getcounter, &dumparg, ISC_STATSDUMP_VERBOSE);
+}
+
+void
+dns_cache_dumpstats(dns_cache_t *cache, FILE *fp) {
+	int indices[dns_cachestatscounter_max];
+	isc_uint64_t values[dns_cachestatscounter_max];
+
+	REQUIRE(VALID_CACHE(cache));
+
+	getcounters(cache->stats, isc_statsformat_file,
+		    dns_cachestatscounter_max, indices, values);
+
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_hits],
+		"cache hits");
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_misses],
+		"cache misses");
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_queryhits],
+		"cache hits (from query)");
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_querymisses],
+		"cache misses (from query)");
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_deletelru],
+		"cache records deleted due to memory exhaustion");
+	fprintf(fp, "%20" ISC_PRINT_QUADFORMAT "u %s\n",
+		values[dns_cachestatscounter_deletettl],
+		"cache records deleted due to TTL expiration");
+	fprintf(fp, "%20u %s\n", dns_db_nodecount(cache->db),
+		"cache database nodes");
+	fprintf(fp, "%20" ISC_PLATFORM_QUADFORMAT "u %s\n",
+		(isc_uint64_t) dns_db_hashsize(cache->db),
+		"cache database hash buckets");
+
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_total(cache->mctx),
+		"cache tree memory total");
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_inuse(cache->mctx),
+		"cache tree memory in use");
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_maxinuse(cache->mctx),
+		"cache tree highest memory in use");
+
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_total(cache->hmctx),
+		"cache heap memory total");
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_inuse(cache->hmctx),
+		"cache heap memory in use");
+	fprintf(fp, "%20u %s\n", (unsigned int) isc_mem_maxinuse(cache->hmctx),
+		"cache heap highest memory in use");
+}
+
+#ifdef HAVE_LIBXML2
+#define TRY0(a) do { xmlrc = (a); if (xmlrc < 0) goto error; } while(0)
+static int
+renderstat(const char *name, isc_uint64_t value, xmlTextWriterPtr writer) {
+	int xmlrc;
+
+	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "counter"));
+	TRY0(xmlTextWriterWriteAttribute(writer,
+					 ISC_XMLCHAR "name", ISC_XMLCHAR name));
+	TRY0(xmlTextWriterWriteFormatString(writer,
+					    "%" ISC_PRINT_QUADFORMAT "u",
+					    value));
+	TRY0(xmlTextWriterEndElement(writer)); /* counter */
+
+error:
+	return (xmlrc);
+}
+
+int
+dns_cache_renderxml(dns_cache_t *cache, xmlTextWriterPtr writer) {
+	int indices[dns_cachestatscounter_max];
+	isc_uint64_t values[dns_cachestatscounter_max];
+	int xmlrc;
+
+	REQUIRE(VALID_CACHE(cache));
+
+	getcounters(cache->stats, isc_statsformat_file,
+		    dns_cachestatscounter_max, indices, values);
+	TRY0(renderstat("CacheHits",
+		   values[dns_cachestatscounter_hits], writer));
+	TRY0(renderstat("CacheMisses",
+		   values[dns_cachestatscounter_misses], writer));
+	TRY0(renderstat("QueryHits",
+		   values[dns_cachestatscounter_queryhits], writer));
+	TRY0(renderstat("QueryMisses",
+		   values[dns_cachestatscounter_querymisses], writer));
+	TRY0(renderstat("DeleteLRU",
+		   values[dns_cachestatscounter_deletelru], writer));
+	TRY0(renderstat("DeleteTTL",
+		   values[dns_cachestatscounter_deletettl], writer));
+
+	TRY0(renderstat("CacheNodes", dns_db_nodecount(cache->db), writer));
+	TRY0(renderstat("CacheBuckets", dns_db_hashsize(cache->db), writer));
+
+	TRY0(renderstat("TreeMemTotal", isc_mem_total(cache->mctx), writer));
+	TRY0(renderstat("TreeMemInUse", isc_mem_inuse(cache->mctx), writer));
+	TRY0(renderstat("TreeMemMax", isc_mem_maxinuse(cache->mctx), writer));
+
+	TRY0(renderstat("HeapMemTotal", isc_mem_total(cache->hmctx), writer));
+	TRY0(renderstat("HeapMemInUse", isc_mem_inuse(cache->hmctx), writer));
+	TRY0(renderstat("HeapMemMax", isc_mem_maxinuse(cache->hmctx), writer));
+error:
+	return (xmlrc);
+}
+#endif
+
+#ifdef HAVE_JSON
+#define CHECKMEM(m) do { \
+	if (m == NULL) { \
+		result = ISC_R_NOMEMORY;\
+		goto error;\
+	} \
+} while(0)
+
+isc_result_t
+dns_cache_renderjson(dns_cache_t *cache, json_object *cstats) {
+	isc_result_t result = ISC_R_SUCCESS;
+	int indices[dns_cachestatscounter_max];
+	isc_uint64_t values[dns_cachestatscounter_max];
+	json_object *obj;
+
+	REQUIRE(VALID_CACHE(cache));
+
+	getcounters(cache->stats, isc_statsformat_file,
+		    dns_cachestatscounter_max, indices, values);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_hits]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheHits", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_misses]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheMisses", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_queryhits]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "QueryHits", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_querymisses]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "QueryMisses", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_deletelru]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "DeleteLRU", obj);
+
+	obj = json_object_new_int64(values[dns_cachestatscounter_deletettl]);
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "DeleteTTL", obj);
+
+	obj = json_object_new_int64(dns_db_nodecount(cache->db));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheNodes", obj);
+
+	obj = json_object_new_int64(dns_db_hashsize(cache->db));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "CacheBuckets", obj);
+
+	obj = json_object_new_int64(isc_mem_total(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "TreeMemTotal", obj);
+
+	obj = json_object_new_int64(isc_mem_inuse(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "TreeMemInUse", obj);
+
+	obj = json_object_new_int64(isc_mem_maxinuse(cache->mctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemMax", obj);
+
+	obj = json_object_new_int64(isc_mem_total(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemTotal", obj);
+
+	obj = json_object_new_int64(isc_mem_inuse(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemInUse", obj);
+
+	obj = json_object_new_int64(isc_mem_maxinuse(cache->hmctx));
+	CHECKMEM(obj);
+	json_object_object_add(cstats, "HeapMemMax", obj);
+
+	result = ISC_R_SUCCESS;
+error:
+	return (result);
+}
+#endif