Improve handling of PREROUTING for NAT

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@102 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb

Shorewall/firewall

@@ -1206,7 +1206,7 @@ setup_nat() {
 		    -j DNAT --to-destination $internal
 	    fi
 	else
-	    run_iptables -t nat -A PREROUTING -i $interface \
+	    addnatrule `input_chain $interface` \
 		-d $external -j DNAT --to-destination $internal
 	    run_iptables -t nat -A POSTROUTING -o $interface \
 		-s $internal -j SNAT --to-source $external
@@ -2843,6 +2843,13 @@ activate_rules() {
 
     multi_interfaces=`find_interfaces_by_option multi`
 
+    for interface in $all_interfaces; do
+	chain=`input_chain $interface`
+
+	havenatchain $chain && \
+	    run_iptables -t nat -A PREROUTING -i $interface -j $chain
+    done
+
     for zone in $zones; do
 	eval source_hosts=\$${zone}_hosts