wpa_supplicant's control socket disappears after suspend (regression?)

Jouni Malinen j at w1.fi
Sat Nov 19 03:22:59 PST 2016

On Wed, Nov 16, 2016 at 09:55:41PM +0100, Andrew Shadura wrote:
> Shortly after wpa_supplicant 2.6 was released, I uploaded it to Debian
> experimental and started using it on my work machine (which runs
> Ubuntu). I soon noticed I often have no wireless connection upon resume
> from suspend, much more often than what I had with either 2.4 or 2.5.
> Also, previously wpa_cli scan would reconnect to the network, now it
> fails to talk to wpa_supplicant:
> Could not connect to wpa_supplicant: (nil) - re-trying

It looks like something in the system is killing wpa_supplicant during
suspend/resume. Or at least your log showed wpa_supplicant started after
resume. Do you know why the process gets killed for that? That would
remove the control interface.. And the way it is started here with NM
would not bring back the per-interface control interface before NM has
(re-)added the interface into the new wpa_supplicant process.

> Restarting both wpa_supplicant and network manager often helps, but
> drives nm-applet crazy for some reason, and I have to restart it. Until
> I restart NM, the interface shows as unmanaged in the applet's menu.

"often helps"? Are you implying this does not always get the
wpa_supplicant control interface back?

> I attempted to run wpa_supplicant manually using the command line from
> its .service file and use wpa_cli, and found out it stopped creating the
> control socket.

Stopped creating? Are you saying that an earlier version behaves
differently when started manually? If you do not specify any interface
on the command line, there cannot really be a per-interface control
interface before that interface has been dynamically added based on the
NM request later..

Jouni Malinen                                            PGP id EFC895FA

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