#!/bin/sh
. /etc/functions.sh
-export WAN=$(nvram get wan_ifname)
-export LAN=$(nvram get lan_ifname)
+WAN=$(nvram get wan_ifname)
+LAN=$(nvram get lan_ifname)
## CLEAR TABLES
for T in filter nat mangle; do
iptables -t nat -N prerouting_rule
iptables -t nat -N postrouting_rule
+### Allow SSH from WAN
+# iptables -t nat -A prerouting_rule -i $WAN -p tcp --dport 22 -j ACCEPT
+# iptables -A input_rule -i $WAN -p tcp --dport 22 -j ACCEPT
+
### Port forwarding
-# iptables -t nat -A prerouting_rule -p tcp --dport 22 -j DNAT --to 192.168.1.2
-# iptables -A forwarding_rule -p tcp --dport 22 -d 192.168.1.2 -j ACCEPT
+# iptables -t nat -A prerouting_rule -i $WAN -p tcp --dport 22 -j DNAT --to 192.168.1.2
+# iptables -A forwarding_rule -i $WAN -p tcp --dport 22 -d 192.168.1.2 -j ACCEPT
+
+### DMZ (should be placed after port forwarding / accept rules)
+# iptables -t nat -A prerouting_rule -i $WAN -j DNAT --to 192.168.1.2
+# iptables -A forwarding_rule -i $WAN -d 192.168.1.2 -j ACCEPT
### INPUT
### (connections with the router as destination)
iptables -P INPUT DROP
iptables -A INPUT -m state --state INVALID -j DROP
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
+ iptables -A INPUT -p tcp --syn --tcp-option \! 2 -j DROP
# allow
- iptables -A INPUT -i \! $WAN -j ACCEPT # allow from lan/wifi interfaces
- iptables -A INPUT -p icmp -j ACCEPT # allow ICMP
- iptables -A INPUT -p 47 -j ACCEPT # allow GRE
+ iptables -A INPUT -i \! $WAN -j ACCEPT # allow from lan/wifi interfaces
+ iptables -A INPUT -p icmp -j ACCEPT # allow ICMP
+ iptables -A INPUT -p gre -j ACCEPT # allow GRE
#
# insert accept rule or to jump to new accept-check table here
#
iptables -A INPUT -j input_rule
# reject (what to do with anything not allowed earlier)
- iptables -A INPUT -p tcp --syn --tcp-option \! 2 -j DROP
iptables -A INPUT -p tcp -j REJECT --reject-with tcp-reset
iptables -A INPUT -j REJECT --reject-with icmp-port-unreachable