gre: Call gso_make_checksum
Call gso_make_checksum. This should have the benefit of using a
checksum that may have been previously computed for the packet.
This also adds NETIF_F_GSO_GRE_CSUM to differentiate devices that
offload GRE GSO with and without the GRE checksum offloaed.
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 f1d3228..24deb39 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -42,6 +42,7 @@
SKB_GSO_DODGY |
SKB_GSO_TCP_ECN |
SKB_GSO_GRE |
+ SKB_GSO_GRE_CSUM |
SKB_GSO_IPIP)))
goto out;
@@ -55,6 +56,8 @@
goto out;
csum = !!(greh->flags & GRE_CSUM);
+ if (csum)
+ skb->encap_hdr_csum = 1;
if (unlikely(!pskb_may_pull(skb, ghl)))
goto out;
@@ -94,10 +97,13 @@
}
}
- greh = (struct gre_base_hdr *)(skb->data);
+ skb_reset_transport_header(skb);
+
+ greh = (struct gre_base_hdr *)
+ skb_transport_header(skb);
pcsum = (__be32 *)(greh + 1);
*pcsum = 0;
- *(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0));
+ *(__sum16 *)pcsum = gso_make_checksum(skb, 0);
}
__skb_push(skb, tnl_hlen - ghl);