net: add skb functions to process remote checksum offload

This patch adds skb_remcsum_process and skb_gro_remcsum_process to
perform the appropriate adjustments to the skb when receiving
remote checksum offload.

Updated vxlan and gue to use these functions.

Tested: Ran TCP_RR and TCP_STREAM netperf for VXLAN and GUE, did
not see any change in performance.

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

1 files changed, 2 insertions, 16 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 31bac2a21ce3..c184717e8b28 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -558,7 +558,6 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
                                           u32 data)
 {
         size_t start, offset, plen;
-        __wsum delta;
 
         if (skb->remcsum_offload)
                 return vh;
@@ -580,12 +579,7 @@ static struct vxlanhdr *vxlan_gro_remcsum(struct sk_buff *skb,
                         return NULL;
         }
 
-        delta = remcsum_adjust((void *)vh + hdrlen,
-                               NAPI_GRO_CB(skb)->csum, start, offset);
-
-        /* Adjust skb->csum since we changed the packet */
-        skb->csum = csum_add(skb->csum, delta);
-        NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);
+        skb_gro_remcsum_process(skb, (void *)vh + hdrlen, start, offset);
 
         skb->remcsum_offload = 1;
 
@@ -1159,7 +1153,6 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
                                       size_t hdrlen, u32 data)
 {
         size_t start, offset, plen;
-        __wsum delta;
 
         if (skb->remcsum_offload) {
                 /* Already processed in GRO path */
@@ -1179,14 +1172,7 @@ static struct vxlanhdr *vxlan_remcsum(struct sk_buff *skb, struct vxlanhdr *vh,
 
         vh = (struct vxlanhdr *)(udp_hdr(skb) + 1);
 
-        if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE))
-                __skb_checksum_complete(skb);
-
-        delta = remcsum_adjust((void *)vh + hdrlen,
-                               skb->csum, start, offset);
-
-        /* Adjust skb->csum since we changed the packet */
-        skb->csum = csum_add(skb->csum, delta);
+        skb_remcsum_process(skb, (void *)vh + hdrlen, start, offset);
 
         return vh;
 }