Re: remote opengl over x11
Re: remote opengl over x11
- Subject: Re: remote opengl over x11
- From: Rich Cook <email@hidden>
- Date: Sat, 22 Jul 2006 16:53:37 -0700
I forgot one more disadvantage to the xauth method: It cannot
circumvent a firewall if your local machine is behind a corportate or
other firewall that blocks port 6000, it won't work.
On Jul 22, 2006, at 4:35 PM, Rich Cook wrote:
There is another solution that has not yet been discussed or
presented in this context: xauth.
xauth is a per-user version of xhost, essentially. It is the best
way to run OpenGL applications "over the wire" as you are doing,
because it does not involve the overhead of encryption that ssh
brings.
To use it, you have to find out the MIT-MAGIC-COOKIE that your X
server is using at the moment. You do this with the following
command:
xauth list
The last number is your cookie. It will look something like
this: 108c8208268d78597c446f52f4be6d1e
You set your DISPLAY to yourhostname:0.0 and run the following
command on the remote machine to add the cookie from your mac to
the remote machine:
/usr/X11R6/bin/xauth add yourhostname:0.0 . your-cookie-here
(Use the actual cooke from your machine, not the one I pasted in
here)
Now the xclients will use this COOKIE to authenticate back to your
mac, and thereafter, OpenGL will be sent in the clear back to your
mac. This is less secure than ssh because people could
theoretically sniff your keystrokes, but it is much harder because
they need to capture your TCP packets and examine them, which
requires they be on your LAN. It is much more secure than xhost,
because anyone on the remote machine can connect to your X server
with xhost, which is a bad thing.
On Jul 21, 2006, at 1:53 PM, Martin Costabel wrote:
Ken Thomases wrote:
[]
Another approach would be to set the LIBGL_ALWAYS_INDIRECT
environment variable (to anything). This forces all clients to
use indirect rendering.
Thank you very much for this valuable information. This solves
another problem that has bothered me for a long time:
When running X11 opengl programs on a remote Mac over a ssh
tunnel, you sometimes get the right graphics window, but it
remains black, and instead of the opengl graphics you get the message
failed to bind to surface
No other error message appears.
This happens whenever the same user that executes the X client is
also logged in at the console on the remote Mac. OpenGL then gets
confused and tries to run quartz opengl instead of X11 opengl.
Setting LIBGL_ALWAYS_INDIRECT prevents this.
--
Martin
_______________________________________________
Do not post admin requests to the list. They will be ignored.
X11-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription: http://lists.apple.com/
mailman/options/x11-users/email@hidden
This email sent to email@hidden
--
Rich "wealthychef" Cook
<http://web.mac.com/wealthychef/iWeb/Site/Urinetown.html>
925-784-3077
--
"Opportunity is missed by most people because it is dressed in
overalls and looks like work." -- C.F. Edison
_______________________________________________
Do not post admin requests to the list. They will be ignored.
X11-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription: http://lists.apple.com/
mailman/options/x11-users/email@hidden
This email sent to email@hidden
--
Rich "wealthychef" Cook
<http://web.mac.com/wealthychef/iWeb/Site/Urinetown.html>
925-784-3077
--
"Opportunity is missed by most people because it is dressed in
overalls and looks like work." -- C.F. Edison
_______________________________________________
Do not post admin requests to the list. They will be ignored.
X11-users mailing list (email@hidden)
This email sent to email@hidden