gre: call skb_gro_checksum_simple_validate

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 6556263c8fa52330efd6e4d9d4f5b491ac9dbe41..d1bd16937d932c78626bc51dd44160598b7cf509 100644 (file)
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -119,28 +119,6 @@ out:
        return segs;
 }
 
-/* Compute the whole skb csum in s/w and store it, then verify GRO csum
- * starting from gro_offset.
- */
-static __sum16 gro_skb_checksum(struct sk_buff *skb)
-{
-       __sum16 sum;
-
-       skb->csum = skb_checksum(skb, 0, skb->len, 0);
-       NAPI_GRO_CB(skb)->csum = csum_sub(skb->csum,
-               csum_partial(skb->data, skb_gro_offset(skb), 0));
-       sum = csum_fold(NAPI_GRO_CB(skb)->csum);
-       if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) {
-               if (unlikely(!sum) && !skb->csum_complete_sw)
-                       netdev_rx_csum_fault(skb->dev);
-       } else {
-               skb->ip_summed = CHECKSUM_COMPLETE;
-               skb->csum_complete_sw = 1;
-       }
-
-       return sum;
-}
-
 static struct sk_buff **gre_gro_receive(struct sk_buff **head,
                                        struct sk_buff *skb)
 {
@@ -192,22 +170,15 @@ static struct sk_buff **gre_gro_receive(struct sk_buff **head,
                if (unlikely(!greh))
                        goto out_unlock;
        }
-       if (greh->flags & GRE_CSUM) { /* Need to verify GRE csum first */
-               __sum16 csum = 0;
-
-               if (skb->ip_summed == CHECKSUM_COMPLETE)
-                       csum = csum_fold(NAPI_GRO_CB(skb)->csum);
-               /* Don't trust csum error calculated/reported by h/w */
-               if (skb->ip_summed == CHECKSUM_NONE || csum != 0)
-                       csum = gro_skb_checksum(skb);
-
-               /* GRE CSUM is the 1's complement of the 1's complement sum
-                * of the GRE hdr plus payload so it should add up to 0xffff
-                * (and 0 after csum_fold()) just like the IPv4 hdr csum.
-                */
-               if (csum)
+
+       /* Don't bother verifying checksum if we're going to flush anyway. */
+       if (greh->flags & GRE_CSUM) {
+               if (!NAPI_GRO_CB(skb)->flush &&
+                   skb_gro_checksum_simple_validate(skb))
                        goto out_unlock;
+               NAPI_GRO_CB(skb)->encapsulation++;
        }
+
        flush = 0;
 
        for (p = *head; p; p = p->next) {