text: /*	$FreeBSD$	*/
  /*	$KAME: ip6.h,v 1.18 2001/03/29 05:34:30 itojun Exp $	*/
  
  /*-
   * SPDX-License-Identifier: BSD-3-Clause
   *
   * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the project nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  /*-
   * Copyright (c) 1982, 1986, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)ip.h	8.1 (Berkeley) 6/10/93
   */
  
  #ifndef _NETINET_IP6_H_
  #define _NETINET_IP6_H_
  
  /*
   * Definition for internet protocol version 6.
   * RFC 2460
   */
  
  struct ip6_hdr {
  	union {
  		struct ip6_hdrctl {
  			u_int32_t ip6_un1_flow;	/* 20 bits of flow-ID */
  			u_int16_t ip6_un1_plen;	/* payload length */
  			u_int8_t  ip6_un1_nxt;	/* next header */
  			u_int8_t  ip6_un1_hlim;	/* hop limit */
  		} ip6_un1;
  		u_int8_t ip6_un2_vfc;	/* 4 bits version, top 4 bits class */
  	} ip6_ctlun;
  	struct in6_addr ip6_src;	/* source address */
  	struct in6_addr ip6_dst;	/* destination address */
  } __packed;
  
  #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
  
  #define IPV6_VERSION		0x60
  #define IPV6_VERSION_MASK	0xf0
  
  #if BYTE_ORDER == BIG_ENDIAN
  #define IPV6_FLOWINFO_MASK	0x0fffffff	/* flow info (28 bits) */
  #define IPV6_FLOWLABEL_MASK	0x000fffff	/* flow label (20 bits) */
  #else
  #if BYTE_ORDER == LITTLE_ENDIAN
  #define IPV6_FLOWINFO_MASK	0xffffff0f	/* flow info (28 bits) */
  #define IPV6_FLOWLABEL_MASK	0xffff0f00	/* flow label (20 bits) */
  #endif /* LITTLE_ENDIAN */
  #endif
  #define IPV6_FLOWLABEL_LEN	20
  
  /*
   * Extension Headers
   */
  
  struct	ip6_ext {
  	u_int8_t ip6e_nxt;
  	u_int8_t ip6e_len;
  } __packed;
  
  /* Hop-by-Hop options header */
  /* XXX should we pad it to force alignment on an 8-byte boundary? */
  struct ip6_hbh {
  	u_int8_t ip6h_nxt;	/* next header */
  	u_int8_t ip6h_len;	/* length in units of 8 octets */
  	/* followed by options */
  } __packed;
  
  /* Destination options header */
  /* XXX should we pad it to force alignment on an 8-byte boundary? */
  struct ip6_dest {
  	u_int8_t ip6d_nxt;	/* next header */
  	u_int8_t ip6d_len;	/* length in units of 8 octets */
  	/* followed by options */
  } __packed;
  
  /* Option types and related macros */
  #define IP6OPT_PAD1		0x00	/* 00 0 00000 */
  #define IP6OPT_PADN		0x01	/* 00 0 00001 */
  #define IP6OPT_JUMBO		0xC2	/* 11 0 00010 = 194 */
  #define IP6OPT_NSAP_ADDR	0xC3	/* 11 0 00011 */
  #define IP6OPT_TUNNEL_LIMIT	0x04	/* 00 0 00100 */
  #ifndef _KERNEL
  #define IP6OPT_RTALERT		0x05	/* 00 0 00101 (KAME definition) */
  #endif
  #define IP6OPT_ROUTER_ALERT	0x05	/* 00 0 00101 (RFC3542, recommended) */
  
  #define IP6OPT_RTALERT_LEN	4
  #define IP6OPT_RTALERT_MLD	0	/* Datagram contains an MLD message */
  #define IP6OPT_RTALERT_RSVP	1	/* Datagram contains an RSVP message */
  #define IP6OPT_RTALERT_ACTNET	2 	/* contains an Active Networks msg */
  #define IP6OPT_MINLEN		2
  
  #define IP6OPT_EID		0x8a	/* 10 0 01010 */
  
  #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_MUTABLE		0x20
  
  /* IPv6 options: common part */
  struct ip6_opt {
  	u_int8_t ip6o_type;
  	u_int8_t ip6o_len;
  } __packed;
  
  /* Jumbo Payload Option */
  struct ip6_opt_jumbo {
  	u_int8_t ip6oj_type;
  	u_int8_t ip6oj_len;
  	u_int8_t ip6oj_jumbo_len[4];
  } __packed;
  #define IP6OPT_JUMBO_LEN	6
  
  /* NSAP Address Option */
  struct ip6_opt_nsap {
  	u_int8_t ip6on_type;
  	u_int8_t ip6on_len;
  	u_int8_t ip6on_src_nsap_len;
  	u_int8_t ip6on_dst_nsap_len;
  	/* followed by source NSAP */
  	/* followed by destination NSAP */
  } __packed;
  
  /* Tunnel Limit Option */
  struct ip6_opt_tunnel {
  	u_int8_t ip6ot_type;
  	u_int8_t ip6ot_len;
  	u_int8_t ip6ot_encap_limit;
  } __packed;
  
  /* Router Alert Option */
  struct ip6_opt_router {
  	u_int8_t ip6or_type;
  	u_int8_t ip6or_len;
  	u_int8_t ip6or_value[2];
  } __packed;
  /* 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
  #if BYTE_ORDER == LITTLE_ENDIAN
  #define IP6_ALERT_MLD	0x0000
  #define IP6_ALERT_RSVP	0x0100
  #define IP6_ALERT_AN	0x0200
  #endif /* LITTLE_ENDIAN */
  #endif
  
  /* Routing header */
  struct ip6_rthdr {
  	u_int8_t  ip6r_nxt;	/* next header */
  	u_int8_t  ip6r_len;	/* length in units of 8 octets */
  	u_int8_t  ip6r_type;	/* routing type */
  	u_int8_t  ip6r_segleft;	/* segments left */
  	/* followed by routing type specific data */
  } __packed;
  
  /* Type 0 Routing header, deprecated by RFC 5095. */
  struct ip6_rthdr0 {
  	u_int8_t  ip6r0_nxt;		/* next header */
  	u_int8_t  ip6r0_len;		/* length in units of 8 octets */
  	u_int8_t  ip6r0_type;		/* always zero */
  	u_int8_t  ip6r0_segleft;	/* segments left */
  	u_int32_t  ip6r0_reserved;	/* reserved field */
  	/* followed by up to 127 struct in6_addr */
  } __packed;
  
  /* Fragment header */
  struct ip6_frag {
  	u_int8_t  ip6f_nxt;		/* next header */
  	u_int8_t  ip6f_reserved;	/* reserved field */
  	u_int16_t ip6f_offlg;		/* offset, reserved, and flag */
  	u_int32_t ip6f_ident;		/* identification */
  } __packed;
  
  #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 /* BYTE_ORDER == LITTLE_ENDIAN */
  
  /*
   * Internet implementation parameters.
   */
  #define IPV6_MAXHLIM	255	/* maximum hoplimit */
  #define IPV6_DEFHLIM	64	/* default hlim */
  #define IPV6_FRAGTTL	120	/* ttl for fragment packets, in slowtimo tick */
  #define IPV6_HLIMDEC	1	/* subtracted when forwarding */
  
  #define IPV6_MMTU	1280	/* minimal MTU and reassembly. 1024 + 256 */
  #define IPV6_MAXPACKET	65535	/* ip6 max packet size without Jumbo payload*/
  #define IPV6_MAXOPTHDR	2048	/* max option header size, 256 64-bit words */
  
  #endif /* not _NETINET_IP6_H_ */
  