Currently the checks are scattered all over and this leads
to inconsistencies and even cases where the check is not made.

Based upon a patch from Kris Katterjohn.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This way we don't have to check it in sk_run_filter().
Signed-off-by: NKris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Patrick McHardy says:

  Never mind, I got it, we never fall through to the second switch
  statement anymore. I think we could simply break when load_pointer
  returns NULL. The switch statement will fall through to the default
  case and return 0 for all cases but 0 > k >= SKF_AD_OFF.

Here's a patch to do just that.

I left BPF_MSH alone because it's really a hack to calculate the IP
header length, which makes no sense when applied to the special data.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As suggested by Herbert Xu:

Since we don't require anything to be in the linear packet range
anymore make len cover the entire packet.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb_header_pointer handles linear and non-linear data, no need to handle
linear data again.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!