Latchesar Ionkov
2007-Jan-21 05:14 UTC
remote port forwarding with dynamic port on the far end
Hi, I would like to use ssh in a quite a strange setup. For every ssh connection the near end starts a service (listening on a free TCP port) that has to be available to the program running on the far end. I would like to have the connection going through SSH (for encryption) so I decided to use remote port forwarding. The problem is that there could be multiple connections of that type to the remote box, so I cannot use constant port on the far end. The first question I have is whether a (fairly trivial) patch that allows ssh -R 0:host:hostport for unprivileged user is going to be accepted? bind on a zero port will pick a free port on the far end, exactly what I need. -R 0:host:port dynamically chosing the port on the far end is not very useful if I don't know the port that was chosen by the system :) So the second question is whether it is acceptible to add a new environment variable passed to the client (say SSH_FORWARDS) that lists all port forwards that the client initiated? Thanks, Lucho