/*!\file netinet/ip6.h
 * IPv6 definitions.
 */

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef _NETINET_IP6_H_
#define _NETINET_IP6_H_

/*
 * Definition for internet protocol version 6.
 * RFC 2460
 */

#ifndef __SYS_SOCKET_H
#include <sys/socket.h>
#endif

W32_CLANG_PACK_WARN_OFF()

#include <sys/pack_on.h>

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 */
     };

#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

/*
 * Extension Headers
 */

struct ip6_ext {
       u_int8_t ip6e_nxt;
       u_int8_t ip6e_len;
     };

/* 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 */
     };

/* 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 */
     };

/* 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_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_BINDING_UPDATE   0xc6    /* 11 0 00110 */
#define IP6OPT_BINDING_ACK      0x07    /* 00 0 00111 */
#define IP6OPT_BINDING_REQ      0x08    /* 00 0 01000 */
#define IP6OPT_HOME_ADDRESS     0xc9    /* 11 0 01001 */
#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

#define IP6OPT_JUMBO_LEN        6

/* 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 */
     };

/* 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_int8_t  ip6r0_reserved;       /* reserved field */
       u_int8_t  ip6r0_slmap[3];       /* strict/loose bit map */
       struct in6_addr  ip6r0_addr[1]; /* up to 23 addresses */
     };

/* 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 */
     };

#include <sys/pack_off.h>

W32_CLANG_PACK_WARN_DEF()

#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     /* maximun hoplimit */
#define IPV6_DEFHLIM    64      /* default hlim */
#define IPV6_FRAGTTL    120     /* ttl for fragment packets, in slowtimo tick */
#define IPV6_HLIMDEC    1       /* subtracted when forwaeding */

#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_CHECK ensures that region between the IP6 header and the
 * target header (including IPv6 itself, extension headers and
 * TCP/UDP/ICMP6 headers) are continuous. KAME requires drivers
 * to store incoming data into one internal mbuf or one or more external
 * mbufs(never into two or more internal mbufs). Thus, the third case is
 * supposed to never be matched but is prepared just in case.
 */

#define IP6_EXTHDR_CHECK(m, off, hlen, ret)                             \
do {                                                                    \
    if ((m)->m_next != NULL) {                                          \
        if (((m)->m_flags & M_LOOP) &&                                  \
            ((m)->m_len < (off) + (hlen)) &&                            \
            (((m) = m_pullup((m), (off) + (hlen))) == NULL)) {          \
                ip6stat.ip6s_exthdrtoolong++;                           \
                return ret;                                             \
        } else if ((m)->m_flags & M_EXT) {                              \
                if ((m)->m_len < (off) + (hlen)) {                      \
                        ip6stat.ip6s_exthdrtoolong++;                   \
                        m_freem(m);                                     \
                        return ret;                                     \
                }                                                       \
        } else {                                                        \
                if ((m)->m_len < (off) + (hlen)) {                      \
                        ip6stat.ip6s_exthdrtoolong++;                   \
                        m_freem(m);                                     \
                        return ret;                                     \
                }                                                       \
        }                                                               \
    } else {                                                            \
        if ((m)->m_len < (off) + (hlen)) {                              \
                ip6stat.ip6s_tooshort++;                                \
                in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);   \
                m_freem(m);                                             \
                return ret;                                             \
        }                                                               \
    }                                                                   \
} while (0)

/*
 * 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), caddr_t) + (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, caddr_t) + tmp);          \
                } else {                                                \
                        (val) = (typ)NULL;                              \
                        (m) = NULL;                                     \
                }                                                       \
        }                                                               \
} while (0)

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

#endif /* not _NETINET_IP6_H_ */
