TCP Re-engineering Tool

TCPreen is a remarkable tool that enables users to keep track and scrutinize data transmitted between clients and servers through connection-oriented streams, particularly TCP sessions. It fully supports TCP over both IPv4 and IPv6. Unlike packet sniffers that concentrate on the lower level transmission protocol, TCPreen focuses mainly on the data stream (software/socket layer).

The tool continually listens on a TCP port for incoming connections. Once the connection is established, TCPreen forwards data transmitted by the connecting client to another server port (which could be on another computer). The server's response is also forwarded back to the client. TCPreen allows data to be displayed on your console in real-time and/or saved into log files for later reference. Additionally, there are various display formatting options.

TCPreen was initially designed to help developers reverse-engineer TCP-based protocols. However, it has also proved to be incredibly useful for debugging network server and client software. Furthermore, it benefits system administrators who intend to monitor a TCP service.

This new release of TCPreen fixed a prospective buffer overflow in the select loop on some platforms. The Brazilian Portuguese localization was also added.