ipv4: Correct comparisons and calculations using skb->tail and skb-transport_header
This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ba4186e..1f58594 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2989,7 +2989,8 @@
swap(gso_skb->truesize, skb->truesize);
}
- delta = htonl(oldlen + (skb->tail - skb->transport_header) +
+ delta = htonl(oldlen + (skb_tail_pointer(skb) -
+ skb_transport_header(skb)) +
skb->data_len);
th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
(__force u32)delta));