skb->len is meaningless to user.
data length could be more helpful, with which we can easily filter out
the packet without payload.
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>