#ifndef _IP6_TUNNEL_H
  #define _IP6_TUNNEL_H

  #include <linux/types.h>

  #define IPV6_TLV_TNL_ENCAP_LIMIT 4
  #define IPV6_DEFAULT_TNL_ENCAP_LIMIT 4
  
  /* don't add encapsulation limit if one isn't present in inner packet */
  #define IP6_TNL_F_IGN_ENCAP_LIMIT 0x1
  /* copy the traffic class field from the inner packet */
  #define IP6_TNL_F_USE_ORIG_TCLASS 0x2
  /* copy the flowlabel from the inner packet */
  #define IP6_TNL_F_USE_ORIG_FLOWLABEL 0x4
  /* being used for Mobile IPv6 */
  #define IP6_TNL_F_MIP6_DEV 0x8
  /* copy DSCP from the outer packet */
  #define IP6_TNL_F_RCV_DSCP_COPY 0x10

  /* copy fwmark from inner packet */
  #define IP6_TNL_F_USE_ORIG_FWMARK 0x20

  
  struct ip6_tnl_parm {
  	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 */
  };
  
  #endif