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Date: Mon, 9 Jan 2006 20:17:24 -0500 (EST)
From: Igor Peshansky <pechtcha AT cs DOT nyu DOT edu>
Reply-To: cygwin AT cygwin DOT com
To: Brett Serkez <techie AT serkez DOT net>
cc: cygwin AT cygwin DOT com
Subject: Re: ZoneAlarm Suite popen hang
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On Mon, 9 Jan 2006, Brett Serkez wrote:

> [snip]
> Using -vvv I see the hang is occuring when ssh executes the
> following command:
>
> sh -c /usr/X11R6/bin/xauth -f /tmp/ssh-OrQEQQHWXE/xauthfile generate 7..0.1:0.0 MIT-MAGIC-COOKIE-1 untrusted timeout 1200 2 > /dev/null
>   /usr/X11R6/bin/xauth:  creating new authority file
>   /home/brett/.Xauthority
>
> Running this command by hand, it looks like it is hanging, but actually
> it is waiting for the command 'exit' on stdin.  Typing exit confirms
> this with a return to the parent shell prompt.
>
> This becomes more obvious when the stderr redirection is removed:
>
> sh -c /usr/X11R6/bin/xauth -f /tmp/ssh-OrQEQQHWXE/xauthfile generate 8..0.1:0.0 MIT-MAGIC-COOKIE-1 untrusted timeout 1200
>   /usr/X11R6/bin/xauth:  creating new authority file
>   /home/brett/.Xauthority Using authority file /home/bserkez/.Xauthority
> xauth>
>
> It looks to me on the surface as if ZoneAlarm is interfering with the
> communication between ssh and xauth via the popen().  This isn't
> completely dissimilar to pipe issues that have been discussed in other
> areas, such as with rsync.
>
> I'm not sure what the next step would be, looking for ideas.

It could also be that the script is assuming that ssh will close stdin.
Try adding a redirection of stdin from /dev/null as well (i.e., use

sh -c /usr/X11R6/bin/xauth -f /tmp/ssh-OrQEQQHWXE/xauthfile generate 7..0.1:0.0 MIT-MAGIC-COOKIE-1 untrusted timeout 1200 2 > /dev/null < /dev/null

) and see if it helps.  If it does, the script is actually buggy, and
needs to be fixed.
HTH,
	Igor
-- 
				http://cs.nyu.edu/~pechtcha/
      |\      _,,,---,,_	    pechtcha AT cs DOT nyu DOT edu | igor AT watson DOT ibm DOT com
ZZZzz /,`.-'`'    -.  ;-;;,_		Igor Peshansky, Ph.D. (name changed!)
     |,4-  ) )-,_. ,\ (  `'-'		old name: Igor Pechtchanski
    '---''(_/--'  `-'\_) fL	a.k.a JaguaR-R-R-r-r-r-.-.-.  Meow!

"Las! je suis sot... -Mais non, tu ne l'es pas, puisque tu t'en rends compte."
"But no -- you are no fool; you call yourself a fool, there's proof enough in
that!" -- Rostand, "Cyrano de Bergerac"


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