File /code/usr/include/netinet/ip6.h

#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

/* Hop-by-Hop options header.  */
struct ip6_hbh
  {
    uint8_t  ip6h_nxt;        /* next hesder.  */
    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 */
    struct in6_addr  ip6r0_addr[1];  /* up to 23 addresses */
  };

/* 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

#endif /* netinet/ip6.h */