Re: [RFC] net: ipv4: drop unicast encapsulated in L2 multicast

From: YOSHIFUJI Hideaki <redacted>
Date: Wed, 03 Sep 2014 10:59:14 +0900

Upper-layer needs to cope eith situation of seeing packets with
"incorrect" L2 header anyway (e.g., in promiscous mode).
I do not see much advantage to drop them here.

It's required to prevent wireless nodes from using the shared wireless
group keys (used for multicast transmission) to inject unicast frames.

The RFCs really do specify this at least on the ipv4 side.