#!/bin/sh
. /etc/functions.sh
-WAN=$(nvram get wan_ifname)
-
-IPT=/usr/sbin/iptables
+export WAN=$(nvram get wan_ifname)
+export IPT=/usr/sbin/iptables
for T in filter nat mangle ; do
$IPT -t $T -F
$IPT -t $T -X
done
+# initial rules
$IPT -t filter -A INPUT -m state --state INVALID -j DROP
$IPT -t filter -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
+$IPT -t filter -A FORWARD -m state --state INVALID -j DROP
+$IPT -t filter -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+
+if [ -d /etc/firewall.d ]; then
+ for fw in /etc/firewall.d/??*; do
+ [ -x $fw ] && $fw
+ done
+fi
+
+# defaults
+
$IPT -t filter -A INPUT -p icmp -j ACCEPT
-$IPT -t filter -A INPUT -p 47 -j ACCEPT # allow GRE
+$IPT -t filter -A INPUT -p 47 -j ACCEPT
$IPT -t filter -A INPUT -i $WAN -p tcp -j REJECT --reject-with tcp-reset
$IPT -t filter -A INPUT -i $WAN -j REJECT --reject-with icmp-port-unreachable
-$IPT -t filter -A FORWARD -m state --state INVALID -j DROP
-$IPT -t filter -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+
$IPT -t filter -A FORWARD -i $WAN -m state --state NEW,INVALID -j DROP
$IPT -t filter -A FORWARD -o $WAN -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu