modules/freifunk:

	- implement generic fix for firewall MASQUERADE
	- implement advanced uci config to control sysctl and /proc values

2 files changed, 112 insertions, 0 deletions

diff --git a/modules/freifunk/root/etc/firewall.freifunk b/modules/freifunk/root/etc/firewall.freifunk
new file mode 100644
index 000000000..ac3fcc55d
--- /dev/null
+++ b/modules/freifunk/root/etc/firewall.freifunk
@@ -0,0 +1,51 @@
+#!/bin/sh
+# Freifunk Firewall addons
+# $Id$
+
+
+#
+# Apply advanced settings
+#
+apply_advanced() {
+	local tcp_ecn
+	local tcp_window_scaling
+	local accept_redirects
+	local accept_source_route
+
+	config_get_bool tcp_ecn $1 tcp_ecn 1
+	config_get_bool tcp_window_scaling $1 tcp_window_scaling 1
+	config_get_bool accept_redirects $1 accept_redirects 0
+	config_get_bool accept_source_route $1 accept_source_route 0
+
+	logger -t firewall.freifunk "tcp_ecn is $tcp_ecn"
+	logger -t firewall.freifunk "tcp_window_scaling is $tcp_window_scaling"
+	logger -t firewall.freifunk "accept_redirects is $accept_redirects"
+	logger -t firewall.freifunk "accept_source_route is $accept_source_route"
+
+	sysctl -w net.ipv4.tcp_ecn=$tcp_ecn >/dev/null
+	sysctl -w net.ipv4.tcp_window_scaling=$tcp_window_scaling >/dev/null
+
+	for f in /proc/sys/net/ipv4/conf/*/accept_redirects; do
+		echo $accept_redirects > $f
+	done
+
+	for f in /proc/sys/net/ipv4/conf/*/accept_source_route; do
+		echo $accept_source_route > $f
+	done
+}
+
+config_foreach apply_advanced advanced
+
+
+#
+# Apply fixes for masquerading rules
+#
+apply_nat_fix() {
+	local up
+	local ifname
+	config_get up $1 up
+	[ -n "$up" ] || return 0
+	(ACTION="ifup" INTERFACE="$1" . /etc/hotplug.d/iface/22-firewall-nat-fix )
+}
+
+config_foreach apply_nat_fix interface
diff --git a/modules/freifunk/root/etc/hotplug.d/iface/22-firewall-nat-fix b/modules/freifunk/root/etc/hotplug.d/iface/22-firewall-nat-fix
new file mode 100644
index 000000000..634f432f0
--- /dev/null
+++ b/modules/freifunk/root/etc/hotplug.d/iface/22-firewall-nat-fix
@@ -0,0 +1,61 @@
+. /lib/firewall/uci_firewall.sh
+unset ZONE
+config_get ifname $INTERFACE ifname
+[ "$ifname" == "lo" ] && exit 0
+
+load_zones() {
+	local name
+	local network
+	config_get name $1 name
+	config_get network $1 network
+	[ -z "$network" ] && network=$name
+	for n in $network; do
+		[ "$n" = "$INTERFACE" ] && ZONE="$ZONE $name"
+	done
+}
+
+config_foreach load_zones zone
+
+[ -z "$ZONE" ] && exit 0
+
+natfix_addr_add() {
+	local network=$1
+	local iface=$2
+
+	config_get parent "$1" interface
+	[ "$network" != "$INTERFACE" -a "$parent" != "$INTERFACE" ] && return 0
+
+	config_get ipaddr "$network" ipaddr
+	[ -n "$ipaddr" ] || return 0
+	config_get netmask "$network" netmask
+	[ -n "$netmask" ] || return 0
+	eval "$(ipcalc.sh $ipaddr $netmask)"
+
+	logger -t firewall.freifunk "adding nat rule for $iface($NETWORK/$PREFIX)"
+	iptables -t nat -A "natfix_$iface" -s "$NETWORK/$PREFIX" -d "$NETWORK/$PREFIX" -j ACCEPT
+}
+
+[ ifup = "$ACTION" ] && {
+	iptables -t nat -N "natfix_$ifname"
+	natfix_addr_add "$INTERFACE" "$ifname"
+	config_foreach natfix_addr_add alias "$ifname"
+
+	for z in $ZONE; do
+		local loaded
+		config_get loaded core loaded
+		[ -n "$loaded" ] && {
+			logger -t firewall.freifunk "applying nat rules on zone $z"
+			iptables -t nat -I "zone_${z}_nat" 1 -o "$ifname" -j "natfix_$ifname"
+		}
+	done
+}
+
+[ ifdown = "$ACTION" ] && {
+	for z in $ZONE; do
+		local up
+		config_get up $z up
+		iptables -t nat -D "zone_${z}_nat" -o "$ifname" -j "natfix_$ifname" 2>/dev/null
+	done
+	iptables -t nat -F "natfix_$ifname" 2>/dev/null
+	iptables -t nat -X "natfix_$ifname" 2>/dev/null
+}