DynNatTunnel

Dynamic target NAT tunneling using socat.

This python utility uses socat to tunnel tcp/udp ports from one host to another. It supports ipv4/6 and was designed to tunnel from ipv4 to ipv6, but other combinations are possible as well.

It supports changing DNS entries (for example dyndns) and will automatically re-start the tunnel with the correct target ip.

As soon as the tunnel starts it will add iptable rules for accepting input traffic for the defined ports. The rules will be removed once terminated. If you don't want that, simply don't run as root.

Dependencies

• Python >=3.6
• socat binary
• iptables (optional)

Usage

Edit the sample config.json

{
  "dest": "my-ipv6-home-address.com",
  "forward": [
	{
	  "prot": "tcp",
	  "src": {
		"stack": 4,
		"port": 32400
	  },
	  "dst": {
		"stack": 6,
		"port": 32400
	  }
	}
  ]
}

Param	Description
prot	Protocol, can be tcp or udp
dest	Destination host where the packets should be tunneled to
forward	The src/dest ports which should be tunneled
stack	4 or 6 depending if the src/target is ipv4 or 6
port	The source / destionation port

Run python3 tunnel.py

Disclaimer

This utility was developed for my own personal needs. Feel free to make changes.