[backfire] firewall: backport NAT reflection from trunk

git-svn-id: svn://svn.openwrt.org/openwrt/branches/backfire@22907 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/firewall/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=firewall
 
 PKG_VERSION:=1
-PKG_RELEASE:=13
+PKG_RELEASE:=14
 
 include $(INCLUDE_DIR)/package.mk
 
@@ -43,6 +43,8 @@ define Package/firewall/install
 	$(INSTALL_BIN) ./files/firewall.init $(1)/etc/init.d/firewall
 	$(INSTALL_DIR) $(1)/etc/hotplug.d/iface
 	$(INSTALL_DATA) ./files/20-firewall $(1)/etc/hotplug.d/iface
+	$(INSTALL_DIR) $(1)/etc/hotplug.d/firewall
+	$(INSTALL_DATA) ./files/reflection.hotplug $(1)/etc/hotplug.d/firewall/10-nat-reflection
 	$(INSTALL_DIR) $(1)/etc
 	$(INSTALL_DATA) ./files/firewall.user $(1)/etc
 endef

package/firewall/files/reflection.hotplug

@@ -0,0 +1,101 @@
+#!/bin/sh
+
+. /etc/functions.sh
+
+if [ "$ACTION" = "add" ] && [ "$INTERFACE" = "wan" ]; then
+	local wanip=$(uci -P/var/state get network.wan.ipaddr)
+
+	iptables -t nat -F nat_reflection_in 2>/dev/null || {
+		iptables -t nat -N nat_reflection_in
+		iptables -t nat -A prerouting_rule -j nat_reflection_in
+	}
+
+	iptables -t nat -F nat_reflection_out 2>/dev/null || {
+		iptables -t nat -N nat_reflection_out
+		iptables -t nat -A postrouting_rule -j nat_reflection_out
+	}
+
+	find_networks() {
+		find_networks_cb() {
+			local cfg="$1"
+			local zone="$2"
+
+			local name
+			config_get name "$cfg" name
+
+			[ "$name" = "$zone" ] && {
+				local network
+				config_get network "$cfg" network
+
+				echo ${network:-$zone}
+				return 1
+			}
+		}
+
+		config_foreach find_networks_cb zone "$1"
+	}
+	
+	setup_fwd() {
+		local cfg="$1"
+
+		local src
+		config_get src "$cfg" src
+
+		[ "$src" = wan ] && {
+			local dest
+			config_get dest "$cfg" dest "lan"
+
+			local net
+			for net in $(find_networks "$dest"); do
+				local lanip=$(uci -P/var/state get network.$net.ipaddr)
+				local lanmk=$(uci -P/var/state get network.$net.netmask)
+
+				local proto
+				config_get proto "$cfg" proto
+
+				local epmin epmax extport
+				config_get extport "$cfg" src_dport
+				[ -n "$extport" ] || return
+
+				epmin="${extport%[-:]*}"; epmax="${extport#*[-:]}"
+				[ "$epmin" != "$epmax" ] || epmax=""
+
+				local ipmin ipmax intport
+				config_get intport "$cfg" dest_port "$extport"
+
+				ipmin="${intport%[-:]*}"; ipmax="${intport#*[-:]}"
+				[ "$ipmin" != "$ipmax" ] || ipmax=""
+
+				local exthost
+				config_get exthost "$cfg" src_dip "$wanip"
+
+				local inthost
+				config_get inthost "$cfg" dest_ip
+				[ -n "$inthost" ] || return
+
+				[ "$proto" = tcpudp ] && proto="tcp udp"
+
+				local p
+				for p in ${proto:-tcp udp}; do
+					case "$p" in
+						tcp|udp)
+							iptables -t nat -A nat_reflection_in \
+								-s $lanip/$lanmk -d $exthost \
+								-p $p --dport $epmin${epmax:+:$epmax} \
+								-j DNAT --to $inthost:$ipmin${ipmax:+-$ipmax}
+
+							iptables -t nat -A nat_reflection_out \
+								-s $lanip/$lanmk -d $inthost \
+								-p $p --dport $ipmin${ipmax:+:$ipmax} \
+								-j SNAT --to-source $lanip
+						;;
+					esac
+				done
+			done
+		}
+	}
+
+	config_load firewall
+	config_foreach setup_fwd redirect
+fi
+