udp: Changes to udp_offload to support remote checksum offload

Add a new GSO type, SKB_GSO_TUNNEL_REMCSUM, which indicates remote
checksum offload being done (in this case inner checksum must not
be offloaded to the NIC).

Added logic in __skb_udp_tunnel_segment to handle remote checksum
offload case.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e48e5c02e877..700189604f3d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3013,7 +3013,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
                 if (nskb->len == len + doffset)
                         goto perform_csum_check;
 
-                if (!sg) {
+                if (!sg && !nskb->remcsum_offload) {
                         nskb->ip_summed = CHECKSUM_NONE;
                         nskb->csum = skb_copy_and_csum_bits(head_skb, offset,
                                                             skb_put(nskb, len),
@@ -3085,7 +3085,7 @@ skip_fraglist:
                 nskb->truesize += nskb->data_len;
 
 perform_csum_check:
-                if (!csum) {
+                if (!csum && !nskb->remcsum_offload) {
                         nskb->csum = skb_checksum(nskb, doffset,
                                                   nskb->len - doffset, 0);
                         nskb->ip_summed = CHECKSUM_NONE;