dist/dhcp/includes/netinet/ip.h

   1 /*      $NetBSD: ip.h,v 1.1 2001/08/03 11:35:35 drochner Exp $  */
   2
   3 /*
   4  * Copyright (c) 1982, 1986, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)ip.h        8.1 (Berkeley) 6/10/93
  32  */
  33
  34 /*
  35  * Definitions for internet protocol version 4.
  36  * Per RFC 791, September 1981.
  37  */
  38 #define IPVERSION       4
  39
  40 /*
  41  * Structure of an internet header, naked of options.
  42  *
  43  * We declare ip_len and ip_off to be short, rather than u_short
  44  * pragmatically since otherwise unsigned comparisons can result
  45  * against negative integers quite easily, and fail in subtle ways.
  46  */
  47 struct ip {
  48         u_int8_t  ip_fvhl;              /* header length, version */
  49         u_int8_t  ip_tos;               /* type of service */
  50         int16_t   ip_len;               /* total length */
  51         u_int16_t ip_id;                /* identification */
  52         int16_t   ip_off;               /* fragment offset field */
  53 #define IP_DF 0x4000                    /* dont fragment flag */
  54 #define IP_MF 0x2000                    /* more fragments flag */
  55 #define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
  56         u_int8_t  ip_ttl;               /* time to live */
  57         u_int8_t  ip_p;                 /* protocol */
  58         u_int16_t ip_sum;               /* checksum */
  59         struct    in_addr ip_src, ip_dst; /* source and dest address */
  60 };
  61
  62 #define IP_V(iph)       ((iph)->ip_fvhl >> 4)
  63 #define IP_HL(iph)      (((iph)->ip_fvhl & 0x0F) << 2)
  64 #define IP_V_SET(iph,x) ((iph)->ip_fvhl = ((iph)->ip_fvhl & 0x0F) | ((x) << 4))
  65 #define IP_HL_SET(iph,x) ((iph)->ip_fvhl = \
  66                           ((iph)->ip_fvhl & 0xF0) | (((x) >> 2) & 0x0F))
  67
  68 #define IP_MAXPACKET    65535           /* maximum packet size */
  69
  70 /*
  71  * Definitions for IP type of service (ip_tos)
  72  */
  73 #define IPTOS_LOWDELAY          0x10
  74 #define IPTOS_THROUGHPUT        0x08
  75 #define IPTOS_RELIABILITY       0x04
  76 /*      IPTOS_LOWCOST           0x02 XXX */
  77
  78 /*
  79  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
  80  */
  81 #define IPTOS_PREC_NETCONTROL           0xe0
  82 #define IPTOS_PREC_INTERNETCONTROL      0xc0
  83 #define IPTOS_PREC_CRITIC_ECP           0xa0
  84 #define IPTOS_PREC_FLASHOVERRIDE        0x80
  85 #define IPTOS_PREC_FLASH                0x60
  86 #define IPTOS_PREC_IMMEDIATE            0x40
  87 #define IPTOS_PREC_PRIORITY             0x20
  88 #define IPTOS_PREC_ROUTINE              0x00
  89
  90 /*
  91  * Definitions for options.
  92  */
  93 #define IPOPT_COPIED(o)         ((o)&0x80)
  94 #define IPOPT_CLASS(o)          ((o)&0x60)
  95 #define IPOPT_NUMBER(o)         ((o)&0x1f)
  96
  97 #define IPOPT_CONTROL           0x00
  98 #define IPOPT_RESERVED1         0x20
  99 #define IPOPT_DEBMEAS           0x40
 100 #define IPOPT_RESERVED2         0x60
 101
 102 #define IPOPT_EOL               0               /* end of option list */
 103 #define IPOPT_NOP               1               /* no operation */
 104
 105 #define IPOPT_RR                7               /* record packet route */
 106 #define IPOPT_TS                68              /* timestamp */
 107 #define IPOPT_SECURITY          130             /* provide s,c,h,tcc */
 108 #define IPOPT_LSRR              131             /* loose source route */
 109 #define IPOPT_SATID             136             /* satnet id */
 110 #define IPOPT_SSRR              137             /* strict source route */
 111
 112 /*
 113  * Offsets to fields in options other than EOL and NOP.
 114  */
 115 #define IPOPT_OPTVAL            0               /* option ID */
 116 #define IPOPT_OLEN              1               /* option length */
 117 #define IPOPT_OFFSET            2               /* offset within option */
 118 #define IPOPT_MINOFF            4               /* min value of above */
 119
 120 /*
 121  * Time stamp option structure.
 122  */
 123 struct  ip_timestamp {
 124         u_int8_t ipt_code;              /* IPOPT_TS */
 125         u_int8_t ipt_len;               /* size of structure (variable) */
 126         u_int8_t ipt_ptr;               /* index of current entry */
 127         u_int8_t ipt_flg_oflw;          /* flags, see below, overflow counter */
 128         union ipt_timestamp {
 129                  u_int32_t ipt_time[1];
 130                  struct ipt_ta {
 131                         struct in_addr ipt_addr;
 132                         u_int32_t ipt_time;
 133                  } ipt_ta[1];
 134         } ipt_timestamp;
 135 };
 136
 137 /* flag bits for ipt_flg */
 138 #define IPOPT_TS_TSONLY         0               /* timestamps only */
 139 #define IPOPT_TS_TSANDADDR      1               /* timestamps and addresses */
 140 #define IPOPT_TS_PRESPEC        3               /* specified modules only */
 141
 142 /* bits for security (not byte swapped) */
 143 #define IPOPT_SECUR_UNCLASS     0x0000
 144 #define IPOPT_SECUR_CONFID      0xf135
 145 #define IPOPT_SECUR_EFTO        0x789a
 146 #define IPOPT_SECUR_MMMM        0xbc4d
 147 #define IPOPT_SECUR_RESTR       0xaf13
 148 #define IPOPT_SECUR_SECRET      0xd788
 149 #define IPOPT_SECUR_TOPSECRET   0x6bc5
 150
 151 /*
 152  * Internet implementation parameters.
 153  */
 154 #define MAXTTL          255             /* maximum time to live (seconds) */
 155 #define IPDEFTTL        64              /* default ttl, from RFC 1340 */
 156 #define IPFRAGTTL       60              /* time to live for frags, slowhz */
 157 #define IPTTLDEC        1               /* subtracted when forwarding */
 158
 159 #define IP_MSS          576             /* default maximum segment size */