Bug#285068: use IP addresses and not names in /var/lib (for XDMCP )

[A Mennucc]

Package: gdm
Version: 2.2.5.5-2
Severity: minor

hi

I have recently incurred in a strange problem when using gdm to 
provide XDMCP access to remote clients

symptoms: the clients would start an endless cycle of restarting 
 the X session ; the X session would last anywhere from 4 seconds
 to 3 minutes, and then abruptly end

cause: my clients are in a local network (192.168. ) ; the DNS server
 is configured to assign temporary DNS names to these clients
 (this is needed, because some services on some servers demand a
 that an IP address resolve to a name - see e.g. the PARANOID clause
 used in /etc/hosts.allow ) ; unfortunately this method is not bulletproof
 and sometimes two clients would get the same DNS name (!)

problem: gdm stores the X authentication data in /var/lib/gdm/
 by using the DNS name, and not the IP number : in that case,
 if two clients' IPs resolve to the same name, there is a clash, hence
 the restarting behaviour
 
solution: (whilst it would be preferrable if my DNS server would not
 be so braindead, yet I think that) 
 gdm should store auth data  in /var/lib/gdm/ using IP addresses 
 (apart from braindead DNS servers, there may be cases in which someone
 actually assigns the same name to multiple hosts on purpose)

a.

PS: my quick fix: I have instructed my clients to use different screen numbers:
 so even in case of a hostname clash, the N in "host:N.Xauth" will be
 different. Just in case someone else ever has this problem.



-- System Information:
Debian Release: 3.0
Architecture: i386 (i686)
Kernel: Linux 2.6.7-1-k7
Locale: LANG=C, LC_CTYPE=C

Versions of packages gdm depends on:
ii  adduser                 3.47             Add and remove users and groups
ii  debconf                 1.4.30.8         Debian configuration management sy
ii  dpkg                    1.10.18.1        Package maintenance system for Deb
ii  gdk-imlib1              1.9.14-2wody1    Gdk-Imlib is an imaging library fo
ii  libart2                 1.4.1.4-3        The Gnome canvas widget - runtime 
ii  libaudiofile0           0.2.3-4          The Audiofile Library
ii  libc6                   2.3.2.ds1-18     GNU C Library: Shared libraries an
ii  libdb3                  3.2.9-19         Berkeley v3 Database Libraries [ru
ii  libesd0                 0.2.29-1         Enlightened Sound Daemon - Shared 
ii  libgdk-pixbuf2          0.17.0-2woody2   The GdkPixBuf library.
ii  libglade-gnome0         1:0.17-2.2       Library to load .glade files at ru
ii  libglade0               1:0.17-2.2       Library to load .glade files at ru
ii  libglib1.2              1.2.10-4         The GLib library of C routines
ii  libgnome32              1.4.1.4-3        The Gnome libraries
ii  libgnomesupport0        1.4.1.4-3        The Gnome libraries (Support libra
ii  libgnomeui32            1.4.1.4-3        The Gnome libraries (User Interfac
ii  libgtk1.2               1.2.10-11        The GIMP Toolkit set of widgets fo
ii  libjpeg62               6b-5             The Independent JPEG Group's JPEG 
ii  libpam-modules          0.72-35          Pluggable Authentication Modules f
ii  libpam0g                0.72-35          Pluggable Authentication Modules l
ii  libpng2                 1.0.12-3.woody.9 PNG library - runtime
ii  libtiff3g               3.5.5-6woody1    Tag Image File Format library
ii  libungif4g              4.1.3-1          shared library for GIF images (run
ii  libwrap0                7.6-9            Wietse Venema's TCP wrappers libra
ii  libxml1                 1:1.8.17-2woody2 GNOME XML library
ii  scrollkeeper            0.3.6-3.1        A free electronic cataloging syste
ii  xlibs                   4.2.1-12.1       X Window System client libraries
ii  zlib1g                  1:1.2.1-3        compression library - runtime

-- debconf information:
  gdm/daemon_name: /usr/bin/gdm
* shared/default-x-display-manager: gdm