open-network-stream via ssh tunnel?

[Mark T.B. Carroll]

Is there any known-working code around that can be used to alter/replace
open-network-stream so that, for particular connections, rather than
just making a direct TCP connection, the system will tunnel via ssh's -L
option so that I can connect to a port on a distant machine that is only
visible to "insiders"?

I'm thinking of something like gnus' nntp-open-via-rlogin-and-telnet
(with ssh instead of rsh), except generic to anything that'll be using
open-network-stream (e.g. so I can do things like setq'ing ERC's
erc-connect-function to something else that goes via ssh).

-- Mark