generic iptables proxy

# generic IPtables proxy

iptproxy() {
  YourIP="$(echo $1 | cut -d ':' -f 1)"
  YourPort="$(echo $1 | cut -d ':' -f 2)"
  TargetIP="$(echo $2 | cut -d ':' -f 1)"
  TargetPort="$(echo $2 | cut -d ':' -f 2)"
  if [ "${YourPort}" = "${YourIP}" -o "${TargetPort}" = "${TargetIP}" ]; then
    iptables -t nat -A PREROUTING --dst $YourIP -p tcp -j DNAT --to $TargetIP
    iptables -t nat -A POSTROUTING -p tcp --dst $TargetIP -j SNAT --to $YourIP
    iptables -t nat -A OUTPUT --dst $YourIP -p tcp -j DNAT --to $TargetIP
  else
    iptables -t nat -A PREROUTING --dst $YourIP -p tcp --dport $YourPort -j DNAT --to $TargetIP:$TargetPort
    iptables -t nat -A POSTROUTING -p tcp --dst $TargetIP --dport $TargetPort -j SNAT --to $YourIP
    iptables -t nat -A OUTPUT --dst $YourIP -p tcp --dport $YourPort -j DNAT --to $TargetIP:$TargetPort
  fi
}