ipv6: Add a receive path hook for vti6 in xfrm6_mode_tunnel.

Add a receive path hook for the IPsec vritual tunnel interface.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index b8a9ed8..6b82fdf 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1508,6 +1508,8 @@
 void xfrm4_local_error(struct sk_buff *skb, u32 mtu);
 int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler);
 int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler);
+int xfrm6_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler);
+int xfrm6_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler);
 int xfrm6_extract_header(struct sk_buff *skb);
 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);