Re: [RFC PATCH 2/2] nl80211: implement beacon change notifier

[Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>]

Hello Johannes and all,

> > From: Vasily Ulyanov <vulyanov@quantenna.com>
> >
> > Notify user-space listeners about beacon data change.
> 
> What would this be needed for, and why couldn't you just directly talk
> to hostapd/wpa_s?

I apologize for email duplication, but it looks like reply from Vasily
has been rejected due to Outlook issues. While we choose between mutt
and gnus, here I briefly repeat the rationale behind these RFC patches.

The nl80211 get_beacon callback appears to be useful in the case when
userspace software needs to retrieve current operational parameters of
AP including HT/VHT IEs. In fact we considered two implementation options:
to implement this functionality either in hostapd (extending its
hostapd_cli interface) or in kernel (adding nl80211 call).

We decided to try nl80211 since there was a stub for NL80211_CMD_GET_BEACON
operation. Beacon change notifier was introduced due to the following reason:
if anyone is interested in AP operational params, then he might be also
interested to know when those params are changed.

Regards,
Sergey