net: skb_checksum: allow custom update/combine for walking skb

Currently, skb_checksum walks over 1) linearized, 2) frags[], and
3) frag_list data and calculats the one's complement, a 32 bit
result suitable for feeding into itself or csum_tcpudp_magic(),
but unsuitable for SCTP as we're calculating CRC32c there.

Hence, in order to not re-implement the very same function in
SCTP (and maybe other protocols) over and over again, use an
update() + combine() callback internally to allow for walking
over the skb with different algorithms.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann
2013-10-30 11:50:51 +01:00
committed by David S. Miller
parent efba721f63
commit 2817a336d4
3 changed files with 37 additions and 13 deletions

View File

@@ -78,6 +78,12 @@ csum_block_add(__wsum csum, __wsum csum2, int offset)
return csum_add(csum, (__force __wsum)sum);
}
static inline __wsum
csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len)
{
return csum_block_add(csum, csum2, offset);
}
static inline __wsum
csum_block_sub(__wsum csum, __wsum csum2, int offset)
{