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

[Nicolas Cavallari <Nicolas.Cavallari@lri.fr>]

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.