dbus, hal over xdmcp?

[Anton Shterenlikht]

On Thu, Jun 18, 2009 at 10:40:38AM -0600, Nathan wrote:
> On Thu, Jun 18, 2009 at 9:25 AM, Anton Shterenlikht<mexas at bristol.ac.uk> wrote:
> > On Wed, Jun 17, 2009 at 10:14:03AM -0600, Nathan wrote:
> >> On Wed, Jun 17, 2009 at 4:14 AM, Anton Shterenlikht<mexas at bristol.ac.uk> wrote:
> >> > no, that doesn't work either.
> >> > I wonder if anybody has actually successfully used dbus with XDMCP.
> >> > I know it should work, but maybe nobody has tried, so perhaps there
> >> > are some issues.
> >> >
> >> > I have a user group of about 20 people, all under the university firewall,
> >> > so insecurity of XDMCP is not a major concern.
> >> > I was thinking of having a powerful XDMCP server as an energy efficient
> >> > and easy to maintain model, since the desktops only need to have a good
> >> > graphics card. If that is not working, then perhaps I have
> >> > to switch to plain ssh tunneling, and have full X installation on all
> >> > desktops.
> >>
> >> I don't know anything about dbus or hal, but we're using a FreeBSD 7.2
> >> server that we just used to connect 150 thin clients (peak load of
> >> about 100 concurrently connected right now) to it over XDMCP to use
> >> gnome.  The biggest trick was finding the magic config line to
> >> configure xdm with (since gdm's xdmcp doesn't work).  After that, our
> >
> > Could you please elaborate on this magic line?
> >
> > many thanks
> >
> > --
> > Anton Shterenlikht
> 
> Absolutely.  I preserved the exact procedures that we did to finally
> make it work, so I'll just paste it in here for you.  The "magic line"
> that took us days to figure out is #2 below (apparently xdm doesn't
> listen to any ipv4 ports/addresses without that line).  Note that it
> causes xdm to simply listen on all interfaces, from what I understand,
> so you would want to modify it if you are not entirely on a secure
> internal LAN.  I used this procedure on FreeBSD 7.2-RELEASE-amd64.
> 
> 1.  Install xdm by entering cd /usr/ports/x11/xdm && make install
> 
> 2.  Add the following to the top of /usr/local/lib/X11/xdm/Xaccess:
> 
>       LISTEN 0.0.0.0

I've got the ip address of the XDMCP server

> 3. ...and in the same file uncomment:
> 
>       *                                       #any host can get a login window

yes, I've got this

> 4. In /usr/local/lib/X11/xdm/Xsession comment out the line:
> 
>       exec /usr/local/bin/xsm

I've got this in, but it's never executed because I use $HOME/.xsession

> 5.  And add this line right below it:
> 
>       exec gnome-session

I see. So your users don't have $HOME/.xsession files?

I guess I could've put /usr/local/bin/mwm here instead of in $HOME/.xsession

> 6.  In /usr/local/lib/X11/xdm/xdm-config use ! to comment out the last
> line so it looks like:
> 
>       !DisplayManager.requestPort:    0

yes, it took me a while to figure this out. The problem is that any
upgrade of xdm overwtites this back to the default.

> 7.  Edit /etc/ttys so that the ttyv8 line has on instead of off so it
> looks like:
> 
>       ttyv8   "/usr/local/bin/xdm -nodaemon"  xterm   on  secure

I start xdm manually. I was under the impression the above line
wouldn't work on a headless box.


> 8.  Run kill -HUP 1 to make init reread /etc/ttys

yes, sure


Few more questions, if you please:

What architecture are your XDMCP server and the desktops?
Do the users start X with -query <ip of the XDMCP server>?

many thanks
anton

-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 928 8233 
Fax: +44 (0)117 929 4423