#!/bin/sh

iptables-restore <<'EOF'
*nat
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A POSTROUTING -o eth0 -j MASQUERADE
COMMIT
*filter
:INPUT ACCEPT [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A FORWARD -p tcp -m tcp --dport 80 -j ACCEPT
-A FORWARD -p tcp -m tcp --dport 53 -j ACCEPT
-A FORWARD -p udp -m udp --dport 53 -j ACCEPT
COMMIT
EOF

echo 1 > /proc/sys/net/ipv4/ip_forward