rknock

rknock is a simple port knocking client written in Rust.
It is suitable for use with the server-side knockd daemon.
At the moment, it wraps nmap, and as such, nmap is required
to run this program.

This is due to constraints of Rusts networking ecosystem, most notably
the inability to disable TCP retransmissions.
I plan to eventually port this to use plain unix sockets.