[DGD] Writing an external network daemon

[Shentino]

My guess is that you would need to handle connections asynchronously, and
presumably the round that initiates an outbound connection is not the same
one it will be established in.

If I were to implement an external daemon, I would have it connect to a
special port which the mudlib listens to.  It only accepts connections from
localhost.

Then, just to prevent spoofing by another user on the same machine, I do a
challenge response on the connection to verify that it is indeed the network
daemon talking to me.

Once that's done, I use the connection as a control channel for when I wanna
boss the daemon around, say, by having it connect.

The connection itself would be relayed transparently by the daemon
connecting out as directed, and also in to the driver, henceforth acting as
a relay.  And again, with a challenge response to make sure the connection
to the driver isn't spoofed.

Once that was done, I would treat the connection as if it was made by the
driver.  As far as I know, a connection is the same no matter which end is
set up first.

Multiplexing on multiple connections could presumably be done inside the
daemon with a select or poll.

At least, that's how I would do it.  I've been pondering doing so myself.  I
do bear in mind though that I might not be the only user on the machine
running the driver, and for that I'm still trying to think of a practically
air tight spoof prevention.