Just needed to add an option to allow external connections to the
ports from the server, then set the proper values in the
authorized_keys file and on the client.
Allows tunnels to specify what address the client with connect to
for upstream connections.
Also changed the tunnel-adder UI.
Also fixed a bug where invalid domains would crash. Needed to
properly return an error dialog.
It pretty much only accomplishes what you can already do with a
normal SSH client. The difference is that keys are generated on
the fly by the server and transmitted for the client to use for
the tunnel.
Turns out SSH has robust semantics for opening generic channels.
Looks like I'll be able to set up tunnels without ever needing to
forward ports on the server, since I can connect the channels with
a custom protocol.
Of course I'll eventually want to support generic SSH clients, but
this makes starting much easier.
