#!/bin/sh

IPTABLES=`which iptables`

echo "Enable NAT:"
echo -n "  IPv4 forwarding: "
if echo 1 > /proc/sys/net/ipv4/ip_forward; then
	echo "done"
else
	echo "failed"
	return 1
fi

echo -n "  iptables postrouting: "
if [ ! -x "${IPTABLES}" ]; then
	echo "missing"
	exit 1
fi

if ${IPTABLES} -t nat -A POSTROUTING -o eth0 -j MASQUERADE; then
	echo "done"
else
	echo "failed"
	exit 1
fi

echo -n "  iptables incoming trafic: "
if ${IPTABLES} -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT; then
	echo "done"
else
	echo "failed"
	exit 1
fi

echo -n "  iptables outgoung trafic: "
if ${IPTABLES} -A FORWARD -i eth1 -o eth0 -j ACCEPT; then
	echo "done"
else
	echo "failed"
	exit 1
fi

exit 0