Hi all, My apologies if what I'm looking for is already possible. If that is the case, I would gratefully welcome pointers to where in the documentation to find it and/or key words to search for. What I hope to accomplish is on-demand activation of ssh port forwards. I gather that the OpenSSH server's -i flag is essentially what I'm looking for, in which something like inetd or systemd already has port 22 open and passes it to sshd at launch. As far as I understand things, the OpenSSH *client* has no similar capability, which is unsurprising given that it's not a server. ;-) For the use case where I want to use an SSH port forward to access a remote service on a regular-ish (but not "always-on") basis, it doesn't really make sense to try to hold that tunnel open all the time with keepalives and timeouts and restarts and such. But setting it up manually each time is suboptimal, especially for someone who uses numerous such tunnels, eg to access a bunch of web-based management interfaces behind a firewall. As far as I know, current capabilities don't allow any reasonable on-demand automated solution. It would be really cool if I could have a meta-server listening on the local port right from boot, and then on access to that port it would invoke something like: /usr/bin/ssh -N -T -L localhost:12345:localhost:12345 user@server ...but with some equivalent to sshd's "-i" flag, so that the ssh client would accept being passed local port 12345 instead of trying to open it itself and erroring out because it's already in use. In my particular use-case I would use a systemd socket unit for this, but if I'm not mistaken xinetd could fulfill that role too, so what I'm looking for is platform-independent and doesn't introduce any systemd dependencies. Finally, it would be convenient if it could take the local socket from the command line rather than requiring custom entries in /etc/services, but that's a minor detail. Does that make sense? Cheers! -Chris _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
