#!/bin/sh

# iptables script 2007-10-17
# by pmo

# Flush old rules, old custom tables
iptables --flush
iptables --delete-chain

# Set default policies for all three default chains
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT DROP

# Enable free use of loopback interfaces
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT

# All TCP sessions should begin with SYN
iptables -A INPUT -p tcp ! --syn -m state --state NEW -s 0.0.0.0/0 -j DROP

# Accept inbound TCP packets
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --dport 21 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 25 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 110 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 9000 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 8767 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 6666 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 6665 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 6669 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 6663 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 14534 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p tcp --dport 6661 -m state --state NEW -s 0.0.0.0/0 -j ACCEPT

# Accept inbound UDP packets
iptables -A INPUT -p udp -m udp --dport 123 -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p udp -m udp --dport 67 -s 0.0.0.0/0 -j ACCEPT
iptables -A INPUT -p udp -m udp --dport 53 -s 0.0.0.0/0 -j ACCEPT

# Accept outbound packets
iptables -I OUTPUT 1 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p udp --dport 53 -m state --state NEW -j ACCEPT