4 export WAN=$(nvram get wan_ifname)
5 export IPT=/usr/sbin/iptables
7 for T in filter nat mangle ; do
13 $IPT -t filter -A INPUT -m state --state INVALID -j DROP
14 $IPT -t filter -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
15 $IPT -t filter -A FORWARD -m state --state INVALID -j DROP
16 $IPT -t filter -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
18 if [ -d /etc/firewall.d ]; then
19 for fw in /etc/firewall.d/??*; do
26 $IPT -t filter -A INPUT -p icmp -j ACCEPT
27 $IPT -t filter -A INPUT -p 47 -j ACCEPT # allow GRE
28 $IPT -t filter -A INPUT -i $WAN -p tcp --syn --tcp-option \! 2 -j DROP
29 $IPT -t filter -A INPUT -i $WAN -p tcp -j REJECT --reject-with tcp-reset
30 $IPT -t filter -A INPUT -i $WAN -j REJECT --reject-with icmp-port-unreachable
32 $IPT -t filter -A FORWARD -i br0 -o br0 -j ACCEPT
33 $IPT -t filter -A FORWARD -i $WAN -m state --state NEW -j DROP
34 $IPT -t filter -A FORWARD -o $WAN -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
36 $IPT -t nat -A POSTROUTING -o $WAN -j MASQUERADE