Tag forwarded X11 connection as remote

Michal Srb msrb at suse.com
Tue Oct 3 01:02:34 AEDT 2017

On pondělí 2. října 2017 13:28:30 CEST Peter Stuge wrote:
> Michal Srb wrote:
> > In case of DRI3, X server tries to pass file descriptor to the X
> > client.  That works over the unix socket between X server and SSH
> > client, but of course can not be sent further over network.  There
> > is no way failure can be detected and the communication gets stuck
> > forever.
> > 
> > The ideal solution would be if ssh marked the connection as remote.
> Not forwarding/proxying also the fd to the remote SSH client?

I am not sure what you are suggesting.

The SSH client runs on the same machine as X server and it connects to it 
using the unix socket. From X server's point of view, the SSH client looks 
just like any other local X application. Except the fact that features like 
SHM and file descriptor passing does not work. Even worse, the file 
descriptors are passed successfully but then ignored.

X server can work with both local and remote clients, but not with remote 
clients that pretend to be local. SSH should mark the connection as remote, so 
X server knows to not attempt things that can not work remotely.

Maybe we could find some workaround that would allow the X server to recognize 
this specific case (DRI3 fd passing), but it is just matter of time when some 
new thing fails.

Michal Srb

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