gre: Support GRE over IPv6

GRE over IPv6 implementation.

Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ip6_tunnel.h b/include/linux/ip6_tunnel.h
index bf22b03..48af63c 100644
--- a/include/linux/ip6_tunnel.h
+++ b/include/linux/ip6_tunnel.h
@@ -31,4 +31,21 @@
 	struct in6_addr raddr;	/* remote tunnel end-point address */
 };
 
+struct ip6_tnl_parm2 {
+	char name[IFNAMSIZ];	/* name of tunnel device */
+	int link;		/* ifindex of underlying L2 interface */
+	__u8 proto;		/* tunnel protocol */
+	__u8 encap_limit;	/* encapsulation limit for tunnel */
+	__u8 hop_limit;		/* hop limit for tunnel */
+	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
+	__u32 flags;		/* tunnel flags */
+	struct in6_addr laddr;	/* local tunnel end-point address */
+	struct in6_addr raddr;	/* remote tunnel end-point address */
+
+	__be16			i_flags;
+	__be16			o_flags;
+	__be32			i_key;
+	__be32			o_key;
+};
+
 #endif