From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <b201d47b8865e79dfe9dc8ca4e8654ed@plan9.bell-labs.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] sshnet usage?
From: "Russ Cox" <rsc@plan9.bell-labs.com>
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Date: Wed, 11 Dec 2002 10:49:41 -0500
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> I can currently reach another network via two ssh hops.  Meaning
> that any files I need transfered between the machines on either
> end of the connections currently have to be transfered by making
> two scp hops.  This is a problem as the middle machine doesn't have
> much disk space.  So ideally I would like to run u9fs at one endpoint
> and sshnet behave as the tunnel.
>
> Am I just incorrect in my interpretation of the man page?

No, I was just confused about how transparent you
wanted the tunnel to be.  As long as you only need the
tunnel to be one way, this is easy.

Basically, if you do

	sshnet hop1
	mntgen
	srvssh hop2

(assuming u9fs is in your path on hop2),
that posts the u9fs service in /srv/hop2,
so that then running

	mntgen
	9fs hop2

in any other window (even without the sshnet)
will mount /n/hop2.

(You could just create /n/hop2, or put mntgen
in your profile.)

If you want more than just ssh access to the
network, you could adapt the following:

	g% cat /usr/rsc/bin/rc/mit
	#!/bin/rc

	if(test -d /net/mit){
		echo 'already have /net/mit' >[1=2]
		exit recursion
	}

	if(test -f /srv/mit)
		mount /srv/mit /net.mit
	if not
		sshnet -m /net.mit -s mit ny.lcs.mit.edu

	if(! test -d /net.mit/tcp){
		echo 'no /net.mit/tcp' >[1=2]
		exit network
	}

	aux/stub -d /net/mit
	bind /net.mit/tcp /net/mit
	g%

This is like just running sshnet, but you end up
being able to decide, on a per-call basis, which
network gets used: addresses like wherever or
tcp!wherever still go out on the local network,
while addresses like mit!wherever go out over
the sshnet tunnel.

If you are using mntgen you could change the
/net.mit's to /n/net.mit to avoid creating another
directory in the root.

Russ