[ConsoleKit] Passing CKCON_X11_DISPLAY to pam_ck_connector

[Alkis Georgopoulos]

Hi,
to login users locally with LTSP, we're doing something like the
following:

root$ echo "CKCON_X11_DISPLAY=$DISPLAY" >> /etc/environment
root$ echo "CKCON_X11_DISPLAY_DEVICE=$(/usr/lib/ConsoleKit/ck-get-x11-display-device 2>/dev/null)" >> /etc/environment
root$ su user
user# <the user is now logged on, and the xsession.d scripts are executed>

That works fine, i.e. if we run:
user# ck-list-sessions | grep x11
we get:
        x11-display = ':0'
        x11-display-device = '/dev/tty7'

But having to modify /etc/environment to properly logon a user under X
surely isn't good practice.

So, I'd like to ask the following questions:
 * Exporting CKCON_X11_DISPLAY* on the current environment, and then
calling `su user` doesn't work for me. It seems that pam isn't reading
the environment of the calling process. Is there some way to make
pam_ck_connector read the values from the environment?

 * I tried pam_env.conf, and that worked, except that I can only set up
static entries there. So that wouldn't work for different CK sessions in
different X displays... Is there any way to do something like
  CKCON_X11_DISPLAY_DEVICE=$(/usr/lib/ConsoleKit/ck-get-x11-display-device 2>/dev/null)
in pam_env.conf ?

 * Any other ideas to properly logon users under X (that doesn't involve
direct OpenSessionWithParameters calls in C or python) would be much
appreciated. I don't think letting Xsession/90consolekit (=it calls
ck-launch-session) register the session would be a good way to do it
though, as some processes that ran as this user before 90consolekit
would not be contained in the CK session.

Thanks in advance.