[IPV6] MIP6: Add receiving mobility header functions through raw socket.

Like ICMPv6, mobility header is handled through raw socket.
In inbound case, check only whether ICMPv6 error should be sent as a reply
or not by kernel.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
This patch was also written by: Antti Tuominen <anttit@tcs.hut.fi>

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/mip6.h b/include/net/mip6.h
index fd43178..68263c6 100644
--- a/include/net/mip6.h
+++ b/include/net/mip6.h
@@ -25,6 +25,9 @@
 #ifndef _NET_MIP6_H
 #define _NET_MIP6_H
 
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
 #define MIP6_OPT_PAD_1	0
 #define MIP6_OPT_PAD_N	1
 
@@ -53,5 +56,6 @@
 
 extern int mip6_init(void);
 extern void mip6_fini(void);
+extern int mip6_mh_filter(struct sock *sk, struct sk_buff *skb);
 
 #endif