cache iterators: rework cache_reset_timers

This patch adds the clause PurgeTimeout that sets the new timer
when conntrackd -t is called. This command is particularly useful
when the sysadmin triggers hand-overs between several nodes without
rebooting as it reduces the timers of the remaining entries in
the kernel. Thus, avoiding clashes between new and old entries that
may trigger INVALID packets.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

5 files changed, 45 insertions, 1 deletions

diff --git a/doc/sync/alarm/conntrackd.conf b/doc/sync/alarm/conntrackd.conf
index a65a378..d6f7a2a 100644
--- a/doc/sync/alarm/conntrackd.conf
+++ b/doc/sync/alarm/conntrackd.conf
@@ -23,6 +23,17 @@ Sync {
 		# takeover process is completed.
 		#
 		CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command resets the timers of the conntracks that
+		# live in the kernel to this new value. This is useful
+		# to purge the connection tracking table of zombie entries
+		# and avoid clashes with old entries if you trigger 
+		# several consecutive hand-overs.
+		#
+		PurgeTimeout 15
 	}
 
 	#
diff --git a/doc/sync/ftfw/conntrackd.conf b/doc/sync/ftfw/conntrackd.conf
index 6fec9a1..8f4d952 100644
--- a/doc/sync/ftfw/conntrackd.conf
+++ b/doc/sync/ftfw/conntrackd.conf
@@ -16,6 +16,17 @@ Sync {
 		#
 		CommitTimeout 180
 
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command resets the timers of the conntracks that
+		# live in the kernel to this new value. This is useful
+		# to purge the connection tracking table of zombie entries
+		# and avoid clashes with old entries if you trigger 
+		# several consecutive hand-overs.
+		#
+		PurgeTimeout 15
+
 		# Set Acknowledgement window size
 		ACKWindowSize 20
 	}
diff --git a/doc/sync/keepalived.conf b/doc/sync/keepalived.conf
index c9c8ac1..84f1383 100644
--- a/doc/sync/keepalived.conf
+++ b/doc/sync/keepalived.conf
@@ -9,6 +9,7 @@ vrrp_sync_group G1 {   # must be before vrrp_instance declaration
   }
   notify_master "/etc/conntrackd/primary-backup.sh primary"
   notify_backup "/etc/conntrackd/primary-backup.sh backup"
+  notify_fault "/etc/conntrackd/primary-backup.sh fault"
 }
 
 vrrp_instance VI_1 {
diff --git a/doc/sync/notrack/conntrackd.conf b/doc/sync/notrack/conntrackd.conf
index d54934a..3ce1fa0 100644
--- a/doc/sync/notrack/conntrackd.conf
+++ b/doc/sync/notrack/conntrackd.conf
@@ -9,6 +9,17 @@ Sync {
 		# takeover process is completed.
 		#
 		CommitTimeout 180
+
+		#
+		# If the firewall replica goes from primary to backup,
+		# the conntrackd -t command is invoked in the script. 
+		# This command resets the timers of the conntracks that
+		# live in the kernel to this new value. This is useful
+		# to purge the connection tracking table of zombie entries
+		# and avoid clashes with old entries if you trigger 
+		# several consecutive hand-overs.
+		#
+		PurgeTimeout 15
 	}
 
 	#
diff --git a/doc/sync/primary-backup.sh b/doc/sync/primary-backup.sh
index 27fb1c3..e5331e3 100755
--- a/doc/sync/primary-backup.sh
+++ b/doc/sync/primary-backup.sh
@@ -95,9 +95,19 @@ case "$1" in
     	logger "ERROR: failed to invoke conntrackd -n"
     fi
     ;;
+  fault)
+    #
+    # shorten kernel conntrack timers to remove the zombie entries.
+    #
+    $CONNTRACKD_BIN -C $CONNTRACKD_CONFIG -t
+    if [ $? -eq 1 ]
+    then
+    	logger "ERROR: failed to invoke conntrackd -t"
+    fi
+    ;;
   *)
     logger "ERROR: unknown state transition"
-    echo "Usage: primary-backup.sh {primary|backup}"
+    echo "Usage: primary-backup.sh {primary|backup|fault}"
     exit 1
     ;;
 esac