udp: pass udp_offload struct to UDP gro callbacks

This patch introduces udp_offload_callbacks which has the same
GRO functions (but not a GSO function) as offload_callbacks,
except there is an argument to a udp_offload struct passed to
gro_receive and gro_complete functions. This additional argument
can be used to retrieve the per port structure of the encapsulation
for use in gro processing (mostly by doing container_of on the
structure).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 679e6e90..47921c2 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1969,7 +1969,7 @@
 	struct sk_buff		*(*gso_segment)(struct sk_buff *skb,
 						netdev_features_t features);
 	struct sk_buff		**(*gro_receive)(struct sk_buff **head,
-					       struct sk_buff *skb);
+						 struct sk_buff *skb);
 	int			(*gro_complete)(struct sk_buff *skb, int nhoff);
 };
 
@@ -1979,10 +1979,21 @@
 	struct list_head	 list;
 };
 
+struct udp_offload;
+
+struct udp_offload_callbacks {
+	struct sk_buff		**(*gro_receive)(struct sk_buff **head,
+						 struct sk_buff *skb,
+						 struct udp_offload *uoff);
+	int			(*gro_complete)(struct sk_buff *skb,
+						int nhoff,
+						struct udp_offload *uoff);
+};
+
 struct udp_offload {
 	__be16			 port;
 	u8			 ipproto;
-	struct offload_callbacks callbacks;
+	struct udp_offload_callbacks callbacks;
 };
 
 /* often modified stats are per cpu, other are shared (netdev->stats) */