net:use help function of skb_checksum_start_offset to calculate offset
Although these are equivalent, but the skb_checksum_start_offset() is more readable.
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 98ecfd7..fc0c42a 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1328,7 +1328,7 @@
/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
* do checksum of UDP packets sent as multiple IP fragments.
*/
- offset = skb->csum_start - skb_headroom(skb);
+ offset = skb_checksum_start_offset(skb);
csum = skb_checksum(skb, offset, skb->len- offset, 0);
offset += skb->csum_offset;
*(__sum16 *)(skb->data + offset) = csum_fold(csum);