#!/usr/bin/env bash
eth_ip=`/sbin/ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'`
ham_ip=`/sbin/ifconfig ham0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'`

TARGET_HAM=$1
TARGET_PORT=$2
/sbin/iptables -t nat -A PREROUTING -d $eth_ip/32 -i eth0 -p tcp -m tcp --dport $TARGET_PORT -j DNAT --to-destination $TARGET_HAM:$TARGET_PORT
/sbin/iptables -t nat -A POSTROUTING -d $TARGET_HAM/32 -p tcp -m tcp --dport $TARGET_PORT -j SNAT --to-source $ham_ip
/sbin/iptables -A INPUT -p tcp --dport $TARGET_PORT -j ACCEPT
echo "Done, remember to enable forwarding"