--- shield-trigger-iptables	2011-01-12 13:59:18.000000000 -0600
+++ shield-trigger-iptables	2011-04-30 18:31:36.373742766 -0500
@@ -32,6 +32,25 @@
 		IPT=ip6tables
 	fi
 
+#	switch -A for iptables to -I
+	if [ "$1" == "-A" ]
+	then
+		TASK="-I"
+	else
+		TASK="-D"
+	fi
+
+#	check to see if pam_shield chain exists and create if necessary
+	if [ "$TASK" == "-I" ]
+	then
+		CHAIN_TEST=`$IPT -L pam_shield 2>/dev/null`
+		if [ -z "$CHAIN_TEST" ]
+		then
+			"$IPT" -N pam_shield
+			"$IPT" -I pam_shield -j DROP
+		fi
+	fi
+
 #
 #	CUSTOMIZE THIS RULE
 #
@@ -43,7 +62,8 @@
 #	* put in the correct port number (22 is ssh)
 #	* add additional rules for additional services as needed
 #
-	"$IPT" "$1" INPUT -i eth0 -p tcp -s "$2" --destination-port 22 -j pam_shield
+
+	"$IPT" "$TASK" INPUT -i eth0 -p tcp -s "$2" -j pam_shield
 
 #	mail -s "[security] pam_shield blocked $2" root <<EOF
 #Another monkey kept off our backs ...