commit c9bdd4b5257406b0608385d19c40b5511decf4f6

commit c9bdd4b5257406b0608385d19c40b5511decf4f6
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
Date:   Mon Mar 12 20:09:15 2007 -0300

    [IP]: Introduce ip_hdrlen()

    For the common sequence "skb->nh.iph->ihl * 4", removing a good number of open
    coded skb->nh.iph uses, now to go after the rest...

    Just out of curiosity, here are the idioms found to get the same result:

    skb->nh.iph->ihl << 2
    skb->nh.iph->ihl<<2
    skb->nh.iph->ihl * 4
    skb->nh.iph->ihl*4
    (skb->nh.iph)->ihl * sizeof(u32)

    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
Edited: Ian Campbell -- just definition.