geneve: add initial netdev driver for GENEVE tunnels

This is an initial implementation of a netdev driver for GENEVE
tunnels.  This implementation uses a fixed UDP port, and only supports
point-to-point links with specific partner endpoints.  Only IPv4
links are supported at this time.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 6d6e502..afccc93 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -390,6 +390,15 @@
 	__be16	high;
 };
 
+/* GENEVE section */
+enum {
+	IFLA_GENEVE_UNSPEC,
+	IFLA_GENEVE_ID,
+	IFLA_GENEVE_REMOTE,
+	__IFLA_GENEVE_MAX
+};
+#define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
+
 /* Bonding section */
 
 enum {