/* Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#ifndef _NETINET_IP6_H

#define _NETINET_IP6_H 1

#include <inttypes.h>

#include <netinet/in.h>

struct ip6_hdr

  {

    union

      {

	struct ip6_hdrctl

	  {

	    uint32_t ip6_un1_flow;   /* 4 bits version, 8 bits TC,

					20 bits flow-ID */

	    uint16_t ip6_un1_plen;   /* payload length */

	    uint8_t  ip6_un1_nxt;    /* next header */

	    uint8_t  ip6_un1_hlim;   /* hop limit */

	  } ip6_un1;

	uint8_t ip6_un2_vfc;       /* 4 bits version, top 4 bits tclass */

      } ip6_ctlun;

    struct in6_addr ip6_src;      /* source address */

    struct in6_addr ip6_dst;      /* destination address */

  };

#define ip6_vfc   ip6_ctlun.ip6_un2_vfc

#define ip6_flow  ip6_ctlun.ip6_un1.ip6_un1_flow

#define ip6_plen  ip6_ctlun.ip6_un1.ip6_un1_plen

#define ip6_nxt   ip6_ctlun.ip6_un1.ip6_un1_nxt

#define ip6_hlim  ip6_ctlun.ip6_un1.ip6_un1_hlim

#define ip6_hops  ip6_ctlun.ip6_un1.ip6_un1_hlim

/* Generic extension header.  */

struct ip6_ext

  {

    uint8_t  ip6e_nxt;		/* next header.  */

    uint8_t  ip6e_len;		/* length in units of 8 octets.  */

  };

/* Hop-by-Hop options header.  */

struct ip6_hbh

  {

    uint8_t  ip6h_nxt;		/* next header.  */

    uint8_t  ip6h_len;		/* length in units of 8 octets.  */

    /* followed by options */

  };

/* Destination options header */

struct ip6_dest

  {

    uint8_t  ip6d_nxt;		/* next header */

    uint8_t  ip6d_len;		/* length in units of 8 octets */

    /* followed by options */

  };

/* Routing header */

struct ip6_rthdr

  {

    uint8_t  ip6r_nxt;		/* next header */

    uint8_t  ip6r_len;		/* length in units of 8 octets */

    uint8_t  ip6r_type;		/* routing type */

    uint8_t  ip6r_segleft;	/* segments left */

    /* followed by routing type specific data */

  };

/* Type 0 Routing header */

struct ip6_rthdr0

  {

    uint8_t  ip6r0_nxt;		/* next header */

    uint8_t  ip6r0_len;		/* length in units of 8 octets */

    uint8_t  ip6r0_type;	/* always zero */

    uint8_t  ip6r0_segleft;	/* segments left */

    uint8_t  ip6r0_reserved;	/* reserved field */

    uint8_t  ip6r0_slmap[3];	/* strict/loose bit map */

    /* followed by up to 127 struct in6_addr */

    struct in6_addr ip6r0_addr[0];

  };

/* Fragment header */

struct ip6_frag

  {

    uint8_t   ip6f_nxt;		/* next header */

    uint8_t   ip6f_reserved;	/* reserved field */

    uint16_t  ip6f_offlg;	/* offset, reserved, and flag */

    uint32_t  ip6f_ident;	/* identification */

  };

#if __BYTE_ORDER == __BIG_ENDIAN

# define IP6F_OFF_MASK       0xfff8  /* mask out offset from _offlg */

# define IP6F_RESERVED_MASK  0x0006  /* reserved bits in ip6f_offlg */

# define IP6F_MORE_FRAG      0x0001  /* more-fragments flag */

#else   /* __BYTE_ORDER == __LITTLE_ENDIAN */

# define IP6F_OFF_MASK       0xf8ff  /* mask out offset from _offlg */

# define IP6F_RESERVED_MASK  0x0600  /* reserved bits in ip6f_offlg */

# define IP6F_MORE_FRAG      0x0100  /* more-fragments flag */

#endif

/* IPv6 options */

struct ip6_opt

  {

    uint8_t  ip6o_type;

    uint8_t  ip6o_len;

  };

/* The high-order 3 bits of the option type define the behavior

 * when processing an unknown option and whether or not the option

 * content changes in flight.

 */

#define IP6OPT_TYPE(o)		((o) & 0xc0)

#define IP6OPT_TYPE_SKIP	0x00

#define IP6OPT_TYPE_DISCARD	0x40

#define IP6OPT_TYPE_FORCEICMP	0x80

#define IP6OPT_TYPE_ICMP	0xc0

#define IP6OPT_TYPE_MUTABLE	0x20

/* Special option types for padding.  */

#define IP6OPT_PAD1	0

#define IP6OPT_PADN	1

#define IP6OPT_JUMBO		0xc2

#define IP6OPT_NSAP_ADDR	0xc3

#define IP6OPT_TUNNEL_LIMIT	0x04

#define IP6OPT_ROUTER_ALERT	0x05

/* Jumbo Payload Option */

struct ip6_opt_jumbo

  {

    uint8_t  ip6oj_type;

    uint8_t  ip6oj_len;

    uint8_t  ip6oj_jumbo_len[4];

  };

#define IP6OPT_JUMBO_LEN	6

/* NSAP Address Option */

struct ip6_opt_nsap

  {

    uint8_t  ip6on_type;

    uint8_t  ip6on_len;

    uint8_t  ip6on_src_nsap_len;

    uint8_t  ip6on_dst_nsap_len;

      /* followed by source NSAP */

      /* followed by destination NSAP */

  };

/* Tunnel Limit Option */

struct ip6_opt_tunnel

  {

    uint8_t  ip6ot_type;

    uint8_t  ip6ot_len;

    uint8_t  ip6ot_encap_limit;

  };

/* Router Alert Option */

struct ip6_opt_router

  {

    uint8_t  ip6or_type;

    uint8_t  ip6or_len;

    uint8_t  ip6or_value[2];

  };

/* Router alert values (in network byte order) */

#if __BYTE_ORDER == __BIG_ENDIAN

# define IP6_ALERT_MLD	0x0000

# define IP6_ALERT_RSVP	0x0001

# define IP6_ALERT_AN	0x0002

#else /* __BYTE_ORDER == __LITTLE_ENDIAN */

# define IP6_ALERT_MLD	0x0000

# define IP6_ALERT_RSVP	0x0100

# define IP6_ALERT_AN	0x0200

#endif

#endif /* netinet/ip6.h */