[vox-tech] can't open display with ssh2

vox-tech@lists.lugod.org vox-tech@lists.lugod.org
Thu, 06 Feb 2003 12:54:29 -0500


On Wed, Feb 05, 2003 at 10:34:54AM -0800, Robin Snyder wrote:
> I'm unable to forward X despite the fact that I used the -X option with
> ssh and ForwardX11 is set to yes in ssh_config on the remote machine (on
> both machines, actually).  I get the error message
> 
> Error: Can't open display:
[...]
> Any idea what's happening?  I saw nothing
> obviously amiss in the output of ssh -v, but will append the output below
> in case others see problems I missed.

Robin,

  Something is either trashing your DISPLAY variable after it is setup 
correctly, or it is never being setup correctly in the first place.
I've seen is machines without a xauth program in my path be a 
problem.

  In the -v output you provided nothing important is different from when 
I try locally...

- I would like to see the output from ssh when you login with "-vvv"
  it displays more information than just -v.

  Also note no changes to any files in /etc are needed to get X forwarding
working on a Debian system, the -X option does what is needed.  By changing
the config files you most likely change the system to _always_ setup an 
X11 tunnel without a -X... setting up a remote tunnel to a machine with
evil people [root] can give them complete access to your local screen 
desktop...

    Thanks,
      Mike

here is what I see on my side...
====
debug1: Entering interactive session.
debug2: callback start
debug1: ssh_session2_setup: id 0
debug1: channel request 0: pty-req
debug3: tty_make_modes: [... a bunch of these...]
debug2: x11_get_proto /usr/bin/X11/xauth list :0 2>/dev/null
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: channel request 0: x11-req
debug1: channel request 0: shell
debug1: fd 3 setting TCP_NODELAY
debug2: callback done
debug1: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel 0: rcvd adjust 131072
Last login: Thu Feb  6 09:43:26 2003 from star on pts/6
Linux star 2.4.19-star6 #1 Sat Sep 14 18:44:37 PDT 2002 i686 unknown

Most of the programs included with the Debian GNU/Linux system are
freely redistributable; the exact distribution terms for each program
are described in the individual files in /usr/share/doc/*/copyright

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Thu Feb  6 09:43:26 2003 from star
root@star:~# xeyes
debug1: client_input_channel_open: ctype x11 rchan 2 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 1389
debug1: fd 7 setting O_NONBLOCK
debug2: fd 7 is O_NONBLOCK
debug1: channel 1: new [x11]
debug1: confirm x11
[this is where I closed the program... and it starts shutting down with]
debug1: channel 1: rcvd eof