D-Bus service activation and access control

[Thiago Macieira]

On Friday, 28 July 2017 15:51:01 PDT you wrote:
> Ah, right.  But what if the session manager (which is responsible for
> starting new VPN client processes) is asked to start 2 tunnels in
> parallel by two independent users?  What happens?  I've read some places
> that D-Bus serializes these calls.  But will two client processes be
> started?  If I've understood the activation concept correctly, only the
> first call will result in a process being started.

Yes, the calls are serialised. One process is started and both calls will be 
delivered to it.

I didn't completely understand what those processes are. Assuming that one of 
them is the actual openvpn process that does the connection, I wouldn't use D-
Bus to launch it. I'd launch it directly from the manager process (probably 
via pkexec to get the tunnel and routes, then drop privileges) and have it 
connect to the system bus for communication.

Out of curiosity: is any of this needed considering NetworkManger already does 
all of it?

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center