Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!mailrus!cwjcc!tut.cis.ohio-state.edu!bloom-beacon!EXPO.LCS.MIT.EDU!keith
From: keith@EXPO.LCS.MIT.EDU (Keith Packard)
Newsgroups: comp.windows.x
Subject: Re: killing clients in xdm
Message-ID: <8812141848.AA11316@EXPO.LCS.MIT.EDU>
Date: 14 Dec 88 18:48:04 GMT
References: <26900056@m.cs.uiuc.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
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> In both cases, the problem seems to be left-over X clients when someone logs
> out. This vaxstaion (a color 3200) has a bad-rep in our group because these
> xterms are left hanging around by people getting used to X (& debugging their
> .twmrc files & xmodmaps).

> Is there a way to blast X clients at that point? Would killing the X server
> and restarting it be too much? Would that even do what I want?

xdm does attempt to kill all of the clients when the session is over.  It expects
the X server to accept a SIGHUP and close all connections.  The only trouble with
this is that if the session exits quickly after spawning a collection of
clients; some of those clients may end up connecting to the server after
it has been reset.  A very simple fix for this would be to have a
reset script run after the session which simply sleeps for 10 seconds or so.  This
would have the unfortunate side-effect of delaying logout by 10 seconds in the
normal case.

Perhaps a better method would be to write a session which notices a quickly
terminated client session and pauses only in that case.  A short C program
would suffice.

The solution I am using here is a more general authorization scheme which prevents
old clients from connecting to the server after the session terminates by
changing the "password" used to access the server.  Expect to hear more about
this scheme in the coming weeks.