Re: [RFC] cfg80211/mac80211: drop GTK-protected unicast IP packets

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2013-12-03 at 11:41 +0100, Nicolas Cavallari wrote:
> On 03/12/2013 10:45, Johannes Berg wrote:
> > On Tue, 2013-12-03 at 10:44 +0100, Nicolas Cavallari wrote:
> >> On 02/12/2013 19:51, Johannes Berg wrote:
> >>> +			if (!ipv4_is_multicast(ip.hdr4.daddr))
> >>> +				return -1;
> >>
> >> So broadcasting to e.g. 192.168.255.255 is now forbidden ?
> > 
> > Please, read the patch :)
> 
> I read the patch further. ipv4_is_multicast only checks if the
> address is in 224/4, so this patch makes __ieee80211_data_to_8023
> returns 0 for 224.0.0.0 to 239.255.255.255, and returns -1 for
> everything else, including the 255.255.255.255, 192.168.255.255 and
> other limited broadcast addresses, which are actually indistinguishable
> from unicast addresses if you don't know the IP configuration.
> 
> If __ieee80211_data_to_8023 returns -1, the packet is dropped as
> being unusable -- no less.

You still haven't even begun to understand the patch. It only cares
about GTK-encrypted frames.

johannes