A third way to invoke svnserve is in
“tunnel mode”, with the
option. This mode assumes that a remote-service program
such as RSH or SSH has
successfully authenticated a user and is now invoking a
private svnserve process as
that user. (Note that you, the user, will
rarely, if ever, have reason to invoke
svnserve with the
the command line; instead, the SSH daemon
does so for you.) The svnserve program
behaves normally (communicating via
stdin and stdout),
and assumes that the traffic is being automatically
redirected over some sort of tunnel back to the client.
When svnserve is invoked by a tunnel
agent like this, be sure that the authenticated user has
full read and write access to the repository database files.
It's essentially the same as a local user accessing the
This option is described in much more detail in the section called “Tunneling over SSH”.