Re: [PATCH 2/4] mac80211: Add radiotap support for Monitor mode RX

From: Michael Wu <flamingice@sourmilk.net>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: andy@warmcat.com, linux-wireless@vger.kernel.org
Subject: Re: [PATCH 2/4] mac80211: Add radiotap support for Monitor mode RX
Date: Thu, 22 Mar 2007 19:18:21 -0400	[thread overview]
Message-ID: <200703221918.22256.flamingice@sourmilk.net> (raw)
In-Reply-To: <1174503091.3944.42.camel@johannes.berg>

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On Wednesday 21 March 2007 14:51, Johannes Berg wrote:
> > +	/* Driver supports radiotap. */
> > +#define IEEE80211_HW_RADIOTAP_SUPPORTED (1<<10)
> >
> > +	if (local->monitors &&
> > +	    local->hw.flags & IEEE80211_HW_RADIOTAP_SUPPORTED) {
> > +		radiotap_len = ieee80211_get_radiotap_len(skb);
> > +		skb_pull(skb, radiotap_len);
> > +	}
>
> I don't think that can work.
>
>  1) it needs a lot more documentation on what a driver needs to do for
>     this (for example that it should only add radiotap headers if a
>     monitor interface was added)
>
Lack of documentation makes code not work?

>  2) afaik local->monitors is increased even for soft monitor interfaces,
>     thus this will really fall on its nose when the driver supports
>     radiotap but not monitor during operation.
>
Yes. I noted that in December when the patch was first posted. This will be 
fixed when I post a radiotap RX patch that's actually signed off. No sign off 
from me means it's not done and probably not tested enough if at all.

-Michael Wu

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