We're now starting to have quite a number of places that do skb_pull
followed immediately by an skb_postpull_rcsum. We can merge these two
operations into one function with skb_pull_rcsum. This makes sense
since most pull operations on receive skb's need to update the
checksum.
I've decided to make this out-of-line since it is fairly big and the
fast path where hardware checksums are enabled need to call
csum_partial anyway.
Since this is a brand new function we get to add an extra check on the
len argument. As it is most callers of skb_pull ignore its return
value which essentially means that there is no check on the len
argument.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>