I want to port forward on the same machine.

When my friends ( who have no access for SSH from their network ) point their SSH client to port 443 ( to trick proxy servers as being using HTTPS traffic ), I wanted my firewall to port forward it to port 22 on the same machine with the same interface.

I'm using shorewall 1.4.8 on Debian and iptables.

P.S --> I'm reading Shorewall site currently but haven't found what I wanted ATM.