[Pkg-utopia-maintainers] Bug#692414: Bug#692414: network-manager: /etc/init.d/network-manager stop leaves wpa_supplicant behind

[Michael Biebl]

Heya,

On 05.11.2012 23:27, Cyril Brulebois wrote:
> 
> “/etc/init.d/network-manager stop” indeed drop all networking,
> but the wpa_supplicant instance it spawned is left behind. Not a
> practical issue when e.g. switching to wicd, but still not nice.
> | root      7820  0.0  0.0  31212  3156 ?        S    23:18   0:00 /sbin/wpa_supplicant -u -s -O /var/run/wpa_supplicant
> 
> The good news is that one gets reused (there's no second one
> started) when network-manager is started again.
> 
> See #692413 for the other way around.

The case for wicd (#692413) is not quite comparable.
wicd explicitly starts an own wpasupplicant instance with a (temporay)
config file and controls that instance. That instance is not usable by
e.g. NM so wicd needs to make sure to correctly terminate that service.

With NM it is different as it simply uses the wpa_supplicant D-Bus
interface and relies on D-Bus activation to start the service on-demand.
It controls wpa_supplicant via D-Bus and not a temporary config file.
So when NM is stopped, the wpa_supplicant service is still usable by
other services.

NM also makes use of other D-Bus (activated) services, like polkitd or
modem-manager. Stopping those in the sysv init script is not safe
as you don't know if those service were actually started by you or if
not another application has requested that D-Bus service.

Ideally, wicd would just use D-Bus interface of wpa_supplicant to
control the service.
This way it could simply use the already running wpa_supplicant instance
when NM is stopped and wicd started.

In contrast to that: NM can use dnsmasq to handle name resolution. For
that it explicitly starts an own instance of dnsmasq which it controls
via a temporary config file.
When NM is stopped it automatically terminates that service.

So in summary: I think the current behaviour of NM is not actually buggy
wrt D-Bus activated services.

Cheers,
Michael


-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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