src/packages/fff/fff-firewall/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fff-firewall
-PKG_RELEASE:=7
+PKG_RELEASE:=8
 
 include $(INCLUDE_DIR)/package.mk
 

src/packages/fff/fff-firewall/files/usr/lib/firewall.d/00-prepare

@@ -5,5 +5,17 @@ ebtables -X
 iptables -F
 iptables -X
 
+iptables -F -t nat
+iptables -X -t nat
+
+iptables -F -t mangle
+iptables -X -t mangle
+
 ip6tables -F
 ip6tables -X
+
+ip6tables -F -t nat
+ip6tables -X -t nat
+
+ip6tables -F -t mangle
+ip6tables -X -t mangle

src/packages/fff/fff-layer3-snat/Makefile

@@ -0,0 +1,32 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=fff-layer3-snat
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/fff-layer3-snat
+	SECTION:=base
+	CATEGORY:=Freifunk
+	TITLE:=Freifunk-Franken layer3 configuration with SNAT
+	URL:=https://www.freifunk-franken.de
+	DEPENDS:= \
+		+iptables-mod-nat-extra \
+		+fff-firewall \
+		+fff-layer3-config
+
+endef
+
+define Package/fff-layer3-snat/description
+	With this package it is possible to make SNAT with IPv4 on the router
+endef
+
+define Build/Compile
+	# nothing
+endef
+
+define Package/fff-layer3-snat/install
+	$(CP) ./files/* $(1)/
+endef
+
+$(eval $(call BuildPackage,fff-layer3-snat))

src/packages/fff/fff-layer3-snat/files/etc/layer3.d/33-snat.conf

@@ -0,0 +1,36 @@
+configure() {
+	# first we delete the snat config
+	uci -q del network.client.fff_snat
+	uci -q del network.client.fff_snat_routerip
+	if [ "$(uci -q get gateway.@client[0].snat)" = '1' ]; then
+
+		# first check the config is plausible
+                routerip=$(uci -q get gateway.meta.routerip)
+		
+		if ! $routerip; then
+			echo "ERROR: No routerip set, which is required for SNAT!"
+			return 1
+		fi
+		if ! uci -q get gateway.@client[0].ipaddr; then
+			echo "ERROR: No ipaddr set, which is required for SNAT!"
+			return 1
+		fi
+
+		# keep only the first IP
+                routerip=${routerip%% *}
+		# keep only the IP without the CIDR
+                routerip=${routerip%%/*}
+
+		# We set the snat config
+		uci set network.client.fff_snat=1
+		uci set network.client.fff_snat_sourceip=$routerip
+	fi
+}
+
+apply() {
+	uci commit network
+}
+
+revert() {
+	uci revert network
+}

src/packages/fff/fff-layer3-snat/files/usr/lib/firewall.d/30-snat

@@ -0,0 +1,3 @@
+if [ "$(uci -q get network.client.fff_snat)" = '1' ]; then
+	iptables -t nat -A POSTROUTING -i br-client -j SNAT --to-source $(uci -q get network.client.fff_snat_sourceip)
+fi

src/packages/fff/fff-layer3/Makefile

@@ -15,6 +15,7 @@ define Package/fff-layer3
 	         +fff-boardname \
 	         +fff-dhcp \
 	         +fff-layer3-config \
+                 +fff-layer3-snat \
 	         +fff-network \
 	         +fff-ra \
 	         +fff-wireguard \