Re: Understanding How Networking Manager Manages Wi-Fi

[Dan Williams <dcbw redhat com>]

On Tue, 2015-09-22 at 23:41 +0530, Ramprasad Vempati wrote:
> Thanks Dan for quick reply. Could you also let me know is this
> interaction to wpa_supplicant is controlled by some config file or is
> it embedded with-in binary?

NM generates the supplicant configuration from its own internal
configuration, which is stored in /etc in various places depending on
your distro.

> And can I configure Network Manager not to manage any of Wi-Fi
> Networks but just Wired networks?  If yes, can you help me how can I
> do that?

You can tell NM to ignore any interface through its configuration file,
by setting "unmanaged-devices" (see man NetworkManager.conf) or by
tagging all wifi devices with a udev rule to tell NM to ignore them.

Dan

> And in that case I'm assuming Network Manager won't even start wpa_supplicant.
>
>
> On Tue, Sep 22, 2015 at 8:33 PM, Dan Williams <dcbw redhat com> wrote:
> > On Tue, 2015-09-22 at 19:54 +0530, Ramprasad Vempati wrote:
> > > Hi,
> > >
> > > I'm interested to understand the flow, in terms of how Network-Manager
> > > controls Wi-Fi. As far as I know Network Manager talks to
> > > wpa_supplicant.
> >
> > Yes, through the D-Bus IPC protocol, which many services on Linux use.
> >
> > > But I'm interested in more details. Like how Network-manager starts
> > > wpa_supplicant?
> >
> > Through D-Bus service activation.  Even if the supplicant is not yet
> > started, NM asks the supplicant a question, and the D-Bus daemon will
> > hold the request, start the supplicant, and pass the request along when
> > it's ready.
> >
> > > And another case I would like to understand is, if I kill
> > > wpa_supplicant that's started by Network-Manager and also remove
> > > wpa_supplicant from /sbin, but run wpa_supplicant from another folder,
> > > does Network-manager finds him & tries to control?
> >
> > Yes, as long as you've built the supplicant with the D-Bus control
> > interface enabled (CONFIG_CTRL_IFACE_DBUS_NEW), and you've started the
> > supplicant with the "-u" option to enable it at runtime.
> >
> > Dan
> >
> > > I tried google to get this information. But I couldn't find any useful
> > > information.
> > >
> > > Can one of you help?
> > >
> > > Thanks,
> > > Ram
> > > _______________________________________________
> > > networkmanager-list mailing list
> > > networkmanager-list gnome org
> > > https://mail.gnome.org/mailman/listinfo/networkmanager-list