Re: Network Manager Fails to control Wi-Fi

[Ramprasad Vempati <ramprasad vempati gmail com>]

Thanks Dan. That's exactly what I wanted to know.

On Fri, Sep 25, 2015 at 8:19 PM, Dan Williams <dcbw redhat com> wrote:
> On Fri, 2015-09-25 at 11:28 +0530, Ramprasad Vempati wrote:
> > Thanks Dan. But can you tell me how will Network-Manager find out PID
> > of wpa_supplicant? Is it via:/run/sendsigs.omit.d/wpasupplicant.pid ,
> > which is from below file? If yes, as long as I remove
> > "/sbin/wpa_supplicant" also, Network-Manager shouldn't be able to
> > control Wi-Fi, right?
>
> NetworkManager doesn't care about the PID of the supplicant, because
> it's using the D-Bus interface to talk to it.  When the supplicant
> starts its D-Bus service enabled, it talks to dbus-daemon and says "hey,
> I'm fi.w1.wpa_supplicant and I'm ready!".  dbus-daemon broadcasts that
> to all other D-Bus clients like NetworkManager.  If the supplicant is
> started already when NM starts, then NM asks dbus-daemon "hey, is
> fi.w1.wpa_supplicant around?".  So there's no pid files involved.
>
> Instead, to make sure the supplicant and NM cannot talk, make sure you
> turn off the D-Bus interface, which you can do by either:
>
> 1) removing the "-u" option
> from /usr/share/dbus-1/system-services/fi.w1.wpa_supplicant1.service
>
> 2) running a different supplicant that isn't built with the D-Bus
> interface in the code, or is run without the "-u" option
>
> Dan
>
> > cat /usr/share/dbus-1/system-services/fi.w1.wpa_supplicant1.service
> > [D-BUS Service]
> > Name=fi.w1.wpa_supplicant1
> > Exec=/sbin/wpa_supplicant -B -P /run/sendsigs.omit.d/wpasupplicant.pid
> > -u -s -O /var/run/wpa_supplicant
> > User=root
> >
> > -ram
> >
> >
> > On Thu, Sep 24, 2015 at 7:57 PM, Dan Williams <dcbw redhat com> wrote:
> > > Since NM couldn't talk to the
> > > supplicant, it will essentially ignore the WiFi interfaces and keep them
> > > in the "unavailable" state.