#!/bin/sh
# Copyright (C) 2006 OpenWrt.org and 2007 Tero Karvinen www.iki.fi/karvinen

iptables -F input_rule
iptables -F output_rule
iptables -F forwarding_rule
iptables -t nat -F prerouting_rule
iptables -t nat -F postrouting_rule

# The following chains are for traffic directed at the IP of the 
# WAN interface

iptables -F input_wan
iptables -F forwarding_wan
iptables -t nat -F prerouting_wan

### Open port to WAN
## -- This allows port 22 to be answered by (dropbear on) the router
# iptables -t nat -A prerouting_wan -p tcp --dport 22 -j ACCEPT 
# iptables        -A input_wan      -p tcp --dport 22 -j ACCEPT

### Port forwarding
## -- This forwards port 8080 on the WAN to port 80 on 192.168.1.2
# iptables -t nat -A prerouting_wan -p tcp --dport 8080 -j DNAT --to 192.168.1.2:80
# iptables        -A forwarding_wan -p tcp --dport 80 -d 192.168.1.2 -j ACCEPT

### DMZ
## -- Connections to ports not handled above will be forwarded to 192.168.1.2
# iptables -t nat -A prerouting_wan -j DNAT --to 192.168.1.2
# iptables        -A forwarding_wan -d 192.168.1.2 -j ACCEPT

## Tero's rules
# Enable essential services (in case ports are closed later)
iptables -A input_rule -p tcp --dport 22 -j ACCEPT
iptables -A input_rule -p tcp --dport 53 -j ACCEPT
# Disable insecure services: unencrypted web admin, telnetd
iptables -A input_rule -p tcp --dport 80 -i lo --source 127.0.0.1 --destination 127.0.0.1 -j ACCEPT
iptables -A input_rule -p tcp --dport 80 -j DROP
iptables -A input_rule -p tcp --dport 23 -j DROP
# Disable all (but ssh that's allowed above)
#iptables -A input_rule -p tcp -j DROP

## Block access to local networks (Tero)
# Private blocks (from RFC 1918: Address Allocation for Private Internets)
iptables -A forwarding_rule      --destination 10.0.0.0/255.0.0.0 -j DROP
iptables -A forwarding_rule  --destination 172.16.0.0/255.240.0.0 -j DROP
iptables -A forwarding_rule --destination 192.168.0.0/255.255.0.0 -j DROP
# Raw SMTP access
iptables -A forwarding_rule -p tcp --dport 25 -j DROP
# Samba / Windows SMB/CIFS file sharing - not enabled because this could hide
# problems
#iptables -A forwarding_rule -m multiport -p tcp --ports 137:139 -j DROP
#iptables -A forwarding_rule -m multiport -p udp --ports 137:139 -j DROP