From: Mark Andrews <marka@isc.org>
Date: Thu, 25 Oct 2012 03:29:10 +0000 (+1100)
Subject: 3405.   [bug]           Handle time going backwards in acache. [RT #31253]
X-Git-Tag: v9.10.0a1~766
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=f3e10cca1b9a95fab5ac7a162c0705e2d9da7370;p=thirdparty%2Fbind9.git

3405.   [bug]           Handle time going backwards in acache. [RT #31253]

Squashed commit of the following:

commit fbf4c8fe2644c101bac870360d3f2c159a90f203
Author: Mark Andrews <marka@isc.org>
Date:   Wed Oct 24 14:43:14 2012 +1100

    remove INSIST and handle time going backwards
---

diff --git a/CHANGES b/CHANGES
index 7a5194465a8..8046ecfaebe 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+3405.	[bug]		Handle time going backwards in acache. [RT #31253]
+
 3404.	[bug]		dnssec-signzone: When re-signing a zone, remove
 			RRSIG and NSEC records from nodes that used to be 
 			in-zone but are now below a zone cut. [RT #31556]
diff --git a/lib/dns/acache.c b/lib/dns/acache.c
index 2ad4981de69..0c96010c2de 100644
--- a/lib/dns/acache.c
+++ b/lib/dns/acache.c
@@ -27,6 +27,7 @@
 #include <isc/random.h>
 #include <isc/refcount.h>
 #include <isc/rwlock.h>
+#include <isc/serial.h>
 #include <isc/task.h>
 #include <isc/time.h>
 #include <isc/timer.h>
@@ -776,10 +777,14 @@ entry_stale(acache_cleaner_t *cleaner, dns_acacheentry_t *entry,
 	 * use and the cleaning interval.
 	 */
 	if (cleaner->overmem) {
-		unsigned int passed =
-			now32 - entry->lastused; /* <= interval */
+		unsigned int passed;
 		isc_uint32_t val;
 
+		if (isc_serial_ge(now32, entry->lastused))
+			passed = now32 - entry->lastused; /* <= interval */
+		else
+			passed = 0;
+
 		if (passed > interval / 2)
 			return (ISC_TRUE);
 		isc_random_get(&val);
@@ -825,8 +830,10 @@ acache_incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
 
 	entry = cleaner->current_entry;
 	isc_stdtime_convert32(cleaner->last_cleanup_time, &last32);
-	INSIST(now32 > last32);
-	interval = now32 - last32;
+	if (isc_serial_ge(now32, last32))
+		interval = now32 - last32;
+	else
+		interval = 0;
 
 	while (n_entries-- > 0) {
 		isc_boolean_t is_stale = ISC_FALSE;