libc/include/netinet/ip6.h - platform/bionic - Git at Google

 /*	$NetBSD: ip6.h,v 1.23 2007/12/25 18:33:46 perry Exp $	*/
 /*	$KAME: ip6.h,v 1.45 2003/06/05 04:46:38 keiichi Exp $	*/

 /*
  * 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
 #if 1
 /* ECN bits proposed by Sally Floyd */
 #define IP6TOS_CE		0x01	/* congestion experienced */
 #define IP6TOS_ECT		0x02	/* ECN-capable transport */
 #endif

 #ifdef _KERNEL
 /*
  * for IPv6 pseudo header checksum
  * XXX nonstandard
  */
 struct ip6_hdr_pseudo {
 	struct in6_addr ip6ph_src;
 	struct in6_addr ip6ph_dst;
 	u_int32_t	ip6ph_len;
 	u_int8_t	ip6ph_zero[3];
 	u_int8_t	ip6ph_nxt;
 } __packed;
 #endif

 /*
  * 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 */
 #define IP6OPT_RTALERT		0x05	/* 00 0 00101 (KAME definition) */
 #define IP6OPT_ROUTER_ALERT	0x05	/* (RFC3542 def, 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_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 */
 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 */
 } __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*/

 #ifdef _KERNEL
 /*
  * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
  * "len") is located in single mbuf, on contiguous memory region.
  * The pointer to the region will be returned to pointer variable "val",
  * with type "typ".
  * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
  * very top of mbuf.  GET0 is likely to make memory copy than GET.
  *
  * XXX we're now testing this, needs m_pulldown()
  */
 #define IP6_EXTHDR_GET(val, typ, m, off, len) \
 do {									\
 	struct mbuf *_t;						\
 	int _tmp;							\
 	if ((m)->m_len >= (off) + (len))				\
 		(val) = (typ)(mtod((m), char *) + (off));		\
 	else {								\
 		_t = m_pulldown((m), (off), (len), &_tmp);		\
 		if (_t) {						\
 			if (_t->m_len < _tmp + (len))			\
 				panic("m_pulldown malfunction");	\
 			(val) = (typ)(mtod(_t, char *) + _tmp);	\
 		} else {						\
 			(val) = (typ)NULL;				\
 			(m) = NULL;					\
 		}							\
 	}								\
 } while (/*CONSTCOND*/ 0)

 #define IP6_EXTHDR_GET0(val, typ, m, off, len) \
 do {									\
 	struct mbuf *_t;						\
 	if ((off) == 0 && (m)->m_len >= len)				\
 		(val) = (typ)mtod((m), void *);			\
 	else {								\
 		_t = m_pulldown((m), (off), (len), NULL);		\
 		if (_t) {						\
 			if (_t->m_len < (len))				\
 				panic("m_pulldown malfunction");	\
 			(val) = (typ)mtod(_t, void *);			\
 		} else {						\
 			(val) = (typ)NULL;				\
 			(m) = NULL;					\
 		}							\
 	}								\
 } while (/*CONSTCOND*/ 0)
 #endif /*_KERNEL*/

 #endif /* !_NETINET_IP6_H_ */
	/* $NetBSD: ip6.h,v 1.23 2007/12/25 18:33:46 perry Exp $ */
	/* $KAME: ip6.h,v 1.45 2003/06/05 04:46:38 keiichi Exp $ */

	/*
	* 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
	#if 1
	/* ECN bits proposed by Sally Floyd */
	#define IP6TOS_CE 0x01 /* congestion experienced */
	#define IP6TOS_ECT 0x02 /* ECN-capable transport */
	#endif

	#ifdef _KERNEL
	/*
	* for IPv6 pseudo header checksum
	* XXX nonstandard
	*/
	struct ip6_hdr_pseudo {
	struct in6_addr ip6ph_src;
	struct in6_addr ip6ph_dst;
	u_int32_t ip6ph_len;
	u_int8_t ip6ph_zero[3];
	u_int8_t ip6ph_nxt;
	} __packed;
	#endif

	/*
	* 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 */
	#define IP6OPT_RTALERT 0x05 /* 00 0 00101 (KAME definition) */
	#define IP6OPT_ROUTER_ALERT 0x05 /* (RFC3542 def, 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_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 */
	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 */
	} __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*/

	#ifdef _KERNEL
	/*
	* IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
	* "len") is located in single mbuf, on contiguous memory region.
	* The pointer to the region will be returned to pointer variable "val",
	* with type "typ".
	* IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
	* very top of mbuf. GET0 is likely to make memory copy than GET.
	*
	* XXX we're now testing this, needs m_pulldown()
	*/
	#define IP6_EXTHDR_GET(val, typ, m, off, len) \
	do { \
	struct mbuf *_t; \
	int _tmp; \
	if ((m)->m_len >= (off) + (len)) \
	(val) = (typ)(mtod((m), char *) + (off)); \
	else { \
	_t = m_pulldown((m), (off), (len), &_tmp); \
	if (_t) { \
	if (_t->m_len < _tmp + (len)) \
	panic("m_pulldown malfunction"); \
	(val) = (typ)(mtod(_t, char *) + _tmp); \
	} else { \
	(val) = (typ)NULL; \
	(m) = NULL; \
	} \
	} \
	} while (/CONSTCOND/ 0)

	#define IP6_EXTHDR_GET0(val, typ, m, off, len) \
	do { \
	struct mbuf *_t; \
	if ((off) == 0 && (m)->m_len >= len) \
	(val) = (typ)mtod((m), void *); \
	else { \
	_t = m_pulldown((m), (off), (len), NULL); \
	if (_t) { \
	if (_t->m_len < (len)) \
	panic("m_pulldown malfunction"); \
	(val) = (typ)mtod(_t, void *); \
	} else { \
	(val) = (typ)NULL; \
	(m) = NULL; \
	} \
	} \
	} while (/CONSTCOND/ 0)
	#endif /_KERNEL/

	#endif /* !_NETINET_IP6_H_ */