rsyncd always compression

[Matt McCutchen]

On Tue, 2009-09-01 at 14:11 +0000, Andrew Gideon wrote:
> On Mon, 31 Aug 2009 13:37:16 -0700, Wayne Davison wrote:
> 
> >> Anyone knows a trick that the server only answer if the client is use
> >> the compression?
> > 
> > This is not currently possible.
> 
> What if rsync-path is set to a little script that only accepts the 
> connection (and exec()s the real rsync binary) if compression is set?

The question was about an rsync daemon.  But something similar is
possible: the daemon can be configured with a "pre-xfer exec" script
that looks at the RSYNC_ARG# environment variables and exits
unsuccessfully if compression is not enabled.  The downside is that,
like rrsync, the script has to reimplement rsync argument parsing and
the enforcement is only as good as the argument parsing.

-- 
Matt