Receiving your own wifi beacons

[Michal Kazior]

On 7 May 2014 01:42, Avery Pennarun <apenwarr at gmail.com> wrote:
> Hi all,
>
> We're currently investigating a problem where the ath10k AP will
> seemingly stop sending out beacons, with no other obvious symptoms
> (hostapd is still working fine).  There's not much I can report
> because, of course, no symptoms.
>
> We would like to detect this situation automatically by watching for
> outgoing beacons, but we've noticed that when we create a monitor
> interface, we can see all the beacons *except* ones generated by the
> local AP.  This seems to also be true with ath9k, so it may not be an
> ath10k-specific problem, but we'd like some way to see them going out
> (at the expense of some wasted CPU, of course).
>
> Is there any magic incantation that can un-hide the beacons?

I don't think you can do that.

Beacons have no tx completion in mac80211 and it's the driver that
requests beacon sk_buffs, not the other way around so there's no way
to sniff them.

Your best option is to look at ath10k debug logs. Each beacon is
submitted upon receiving an SWBA event from firmware.

If you want to be verify if beacons are on air you need an extra
device to act as a sniffer though.


Michał