Message-Id: <1136853906.20233.251462872@webmail.messagingengine.com>
From: "Brett Serkez" <techie AT serkez DOT net>
To: cygwin AT cygwin DOT com
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Subject: ZoneAlarm Suite popen hang
Date: Mon, 09 Jan 2006 19:45:06 -0500
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I recently upgraded from ZoneAlarm Pro to ZoneAlarm Suite (both version
6.1.737.000).

Other than the usual issues with bash and sshd, I suddenly found that
trying to use ssh with X forwarding hung.  Before complaining that
this should be posted on the X11 list, I don't believe the issue is
related to X.

After digging I found that the only way this works is to completely
uninstall ZoneAlarm Suite, no amount of fiddling or disabling of
options helps.

Here is where it gets very interesting.

Digging in the mailing list, I found this:

http://www.cygwin.com/ml/cygwin/2004-11/msg00626.html

This message talks in some depth on the subject in general (sans
ZoneAlarm) and zeros in on popen of a specific xauth command via sh.  I
don't see any final resolution in this message and for me, killing sh
helps only in the first case.

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.

Brett
----------------------------------------------------------------
Brett C. Serkez, Techie


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