using dbus to prevent the users from enabling a laptop microphone

[Kay Sievers]

On Sat, May 9, 2009 at 17:15, Colin Walters <walters at verbum.org> wrote:
> On Fri, May 8, 2009 at 2:04 PM, Kent Baxley <kb4xley at gmail.com> wrote:
>
>> The user, however, has control over the mixer channels and can simply
>> override this with a simple mouse click on the appropriate channel using the
>
> I'm not sure of a good way to handle this without modifying source
> code.  But if you are willing to change the source, the way GNOME
> usually does "lockdown" features like this is by having a GConf key to
> disable a feature, and then you can add a mandatory setting.
>
>> The end goal would be  to monitor this mouse click, and if the microphone is
>> enabled, issue a popup message warning the user of the potential
>> foolishness of their actions.
>
> If you want to take the "warning" approach, having a program that runs
> inside the user session which monitors using the ALSA API (I believe
> this is possible), then you can use say zenity or pygtk to pop up a
> dialog.

We assign access control lists to the alsa device nodes for the local
user. The user can always access the nodes directly.

If this is about real security, and not just some "nice notification"
which does not need to be trusted, this would need to happen at the
system level that grants user access to device nodes. This would
involve HAL and PolicyKit. Such hooks are not implemented at the
moment, and there is no interface you could use today.

Kay