Subject: Re: [patch 5/5] d80211: add ioctl to stop data frame tx

From: Elliot Schwartz <[email-masked]>
Date: Mon, 28 Aug 2006 11:29:24 -0700

Hi Johannes,

Johannes Berg <[email-masked]> writes:
> On Tue, 2006-08-22 at 10:34 -0700, David Kimdon wrote:
> > This ioctl is used when radar is delected on a channel.  Data
> > frames must stop but management frames must be allowed to continue
> > for some time to communicate the channel switch to stations.
>
> Which does lead to the question: How are you detecting radar in
> userspace in the first place??

I've been working on merging Devicescape's 802.11h / radar detection
implementation into the open source hostapd (and the wireless-dev kernel). 

Radar is initially detected by the low-level radio driver.  Userspace
gets notified of radar via calls to ieee80211_radar_status, which
generates a "fake" management frame with a struct ieee80211_radar_info
in it.  Userspace is then responsible for handling the resultant
activities, such as stopping transmission on that channel, selecting
another channel, sending out channel switch announcements, changing
channels, and remembering to block use of the old channel for the
required time.

I'll reply to your and Jiri's other question separately.

Thanks,

elliot