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>

2 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index a071563a7e6e..e9767079a360 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -78,6 +78,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                        SKB_GSO_SIT |
                        SKB_GSO_UDP_TUNNEL |
                        SKB_GSO_UDP_TUNNEL_CSUM |
+                       SKB_GSO_TUNNEL_REMCSUM |
                        SKB_GSO_MPLS |
                        SKB_GSO_TCPV6 |
                        0)))
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 6b8f543f6ac6..637ba2e438b7 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -42,6 +42,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
                                       SKB_GSO_DODGY |
                                       SKB_GSO_UDP_TUNNEL |
                                       SKB_GSO_UDP_TUNNEL_CSUM |
+                                      SKB_GSO_TUNNEL_REMCSUM |
                                       SKB_GSO_GRE |
                                       SKB_GSO_GRE_CSUM |
                                       SKB_GSO_IPIP |