socat

Multipurpose relay and more

socat is a relay for bidirectional data transfer between two independent data channels. Each of these data channels may be a file, pipe, device (terminal or modem etc.), socket (UNIX, IP4, IP6 - raw, UDP, TCP), a file descriptor (stdin etc.), a program, or an arbitrary combination of two of these. socat can be used, e.g., as TCP relay (one-shot or daemon), as an external socksifier, for attacking weak firewalls, as a shell interface to UNIX sockets, IP6 relay, for redirecting TCP oriented programs like brutus to a serial line, or to establish a relatively secure environment (su and chroot) for running client or server shell scripts with network connections.