net/sctp: Refactor SCTP skb checksum computation
This patch consolidates the SCTP checksum calculation code from various
places to a single new function, sctp_compute_cksum(skb, offset).
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sctp/checksum.h b/include/net/sctp/checksum.h
index 78b88aa..483e630 100644
--- a/include/net/sctp/checksum.h
+++ b/include/net/sctp/checksum.h
@@ -85,4 +85,19 @@
return cpu_to_le32(~crc32);
}
+/* Calculate the CRC32C checksum of an SCTP packet. */
+static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
+ unsigned int offset)
+{
+ const struct sk_buff *iter;
+
+ __u32 crc32 = sctp_start_cksum(skb->data + offset,
+ skb_headlen(skb) - offset);
+ skb_walk_frags(skb, iter)
+ crc32 = sctp_update_cksum((__u8 *) iter->data,
+ skb_headlen(iter), crc32);
+
+ return sctp_end_cksum(crc32);
+}
+
#endif /* __sctp_checksum_h__ */