Reverse TCP Tunnel allows us to build a reverse TCP tunnel to open inbound access via a public end point. It virutally extends the TCP listening port to a remote machine in which a Reverse TCP Tunnel listener is running.

We use a simple signaling protocol for tunnel establishment and data traffic multiplexing. It is mainly for concept validation and personal exercises.

Tunnel listener runs in a public end point, when it receives a ListenRequest from service that needs tunnelized inbound access, it opens a dynamic TCP port at public interface and multiplexes traffic between service client and the service provider.

Example command to launch tunnel listener

./tunnel -l 5555

Tunnel connector runs wihin the private network boundary, it has access to services that requires tunnelized inbound access.

Example command to establish a reverse tunnelling setup

./tunnel -c localhost:5555 www.myservice.com:80

go build