On Tue, 24 Aug 2004 21:05:32 +1000
Herbert Xu [off-list ref] wrote:

The idea is simple.  None of the callers of skb_checksum are passing it
skb's which are shared.  They may be cloned however.  But the application
checksum is always in the skb header so there is no need to linearise it.

What about looping back of multicast packets via netif_rx(),
is that handled correctly too?

I only mention it because that is the case that causes
problems elsewhere.

I'm going to think over this later today some more.