Re: ['N-M is not allowed to own the service "org.freedesktop.NetworkManager"']

[Dan Williams <dcbw redhat com>]

On Wed, 2010-06-16 at 13:56 -0400, Daniel Gnoutcheff wrote:
> On 06/16/2010 01:01 PM, ddreamer ms93 url com tw wrote:
> > Hi, Dear:
> > 
> > I am using Ubuntu 10.04 with regular update. There is a red exclamation
> > mark at the right lower corner of the nm-applet icon. Of course, there
> > was no signal level. Clicking it results in the message of
> > "NetworkManager is not running".
> > 
> > Looking up daemon.log, I found the following message:
> > NetworkManager: <WARN>  nm_dbus_manager_start_service(): Could not
> > acquire the NetworkManager service.#012  Error: 'Connection ":1.216" is
> > not allowed to own the service "org.freedesktop.NetworkManager" due to
> > security policies in the configuration file'
> > NetworkManager: <WARN>  main(): Failed to start the dbus service.
> 
> Yep, that certainly would cause problems, and it's not altogether
> surprising that this would happen. The DBus system daemon has a very
> strong security policy, and daemons like NetworkManager need to setup
> specific security exceptions in order to work. Normally, this is
> something that distributions take care of, but here it seems to have
> broken somehow.
> 
> More specifcally, NetworkManager needs to be able to claim the bus name
> "org.freedesktop.NetworkManager" on the DBus system bus. By default, no
> application is allowed to claim any bus names, so we need to configure
> DBus to allow N-M to claim that name.
> 
> On Ubuntu, the file
>   /etc/dbus-1/system.d/NetworkManager.conf
> is supposed to take care of that. What does that file contain on your
> system?
> 
> 
> > I opened a terminal and run 'sudo start network-manager', which showed
> > OK. Seconds later, running 'sudo service network-manager status' showed
> > 'network-manager stop/waiting'. Somehow, the daemon quit on it own very
> > soon.
> 
> Yep, that's not surprising. If NetworkManager is unable to obtain its
> characteristic bus name, it quits.  The only way to use NetworkManager
> is over DBus, so it really needs to have those security exceptions in
> place in order to work at all.

For a while there's been a bug in D-Bus itself (since fixed) that if you
wrote or updated a permissions file in /etc/dbus-1/system.d, the bus
would sometimes fail to completely re-read that permissions file.  If
you run into this problem, you can sometimes:

killall -HUP dbus-daemon

and then stuff will work.  If that doesn't work, then the D-Bus
permissions listed in the file may not be correct for your distro.

Dan