User bus?

[Patryk Zawadzki]

On Tue, Mar 4, 2008 at 10:48 AM, Thiago Macieira <thiago at kde.org> wrote:
> On Tuesday 04 March 2008 10:24:57 Patryk Zawadzki wrote:
>  > It would be more or less trivial to implement if
>  > CK could provide such information (protected by some PolicyKit policy)
>  > and I believe such information really belongs to ConsoleKit as it is
>  > *the* session tracking service.
>  I don't agree. For me it seems the most natural place to store the session
>  information is *in* the session. That's the X11 window. No need for reaping:
>  if the session goes away (X11 connection closed), the information
>  automatically goes to the limbo as well.
>
>  However, having a registry of all available sessions would bring back some
>  functionality of DCOP we lost during the switch. Except you still can't
>  connect to any other user's busses.

(Not having enough time now to reply to your message as a whole)

It shouldn't be hard to change your effective uid before connecting to
the specific session and it's not likely that anyone but root (or some
suid helper for - say - copying clipboard contents between two
sessions) would ever need to connect to other sessions (it would be
insecure to allow anyone to do so). Such actions would require a
"push" instead of subscription in order to work and in many cases
would not be safe to be broadcasted using the system bus (like the
mentioned "copy foo between sessions" case as "foo" could be something
confidential). Another solution would be to broadcast a signal telling
"please establish a private bus connection" but that's so much harder
to do properly.

-- 
Patryk Zawadzki
PLD Linux Distribution