After fiddling with some ideas revolving around HAProxy as a transparent proxy, I wondered if HAProxy supports the SOCKS4 protocol as an alternative to its own PROXY protocol. Looking at the 1.7 documentation and source code it seems it doesn't (yet).
Thus, given how simple the SOCKS4 (not SOCKS4a or SOCKS5) protocol is, I wanted to ask if anyone has coded a small patch to support it? If not, any pointers on how to implement it? Looking through the source code, I assume cloning `conn_recv_proxy` should do the trick if only the SOCKS4 protocol wouldn't require that the server talks back to the client. Thus should I assume that it should also borrow code from `conn_si_send_proxy`? (The SOCKS4 handshake implies the client speaks first with a couple of bytes, variable length but clearly determined, and as a result the server sends back a couple of other bytes, exact length this time; afterwards it just implies piping data from one end to the other.) Thanks, Ciprian.
