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   1 /*
   2  * Copyright (c) 1982, 1986, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)ip.h        8.2 (Berkeley) 6/1/94
  34  */
  35
  36 #ifndef netdissect_ip_h
  37 #define netdissect_ip_h
  38
  39 /*
  40  * Definitions for internet protocol version 4.
  41  * Per RFC 791, September 1981.
  42  */
  43 #define IPVERSION       4
  44
  45 /*
  46  * Structure of an internet header, naked of options.
  47  *
  48  * We declare ip_len and ip_off to be short, rather than u_short
  49  * pragmatically since otherwise unsigned comparisons can result
  50  * against negative integers quite easily, and fail in subtle ways.
  51  */
  52 struct ip {
  53         nd_uint8_t      ip_vhl;         /* header length, version */
  54 #define IP_V(ip)        ((GET_U_1((ip)->ip_vhl) & 0xf0) >> 4)
  55 #define IP_HL(ip)       (GET_U_1((ip)->ip_vhl) & 0x0f)
  56         nd_uint8_t      ip_tos;         /* type of service */
  57         nd_uint16_t     ip_len;         /* total length */
  58         nd_uint16_t     ip_id;          /* identification */
  59         nd_uint16_t     ip_off;         /* fragment offset field */
  60 #define IP_DF 0x4000                    /* don't fragment flag */
  61 #define IP_MF 0x2000                    /* more fragments flag */
  62 #define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
  63         nd_uint8_t      ip_ttl;         /* time to live */
  64         nd_uint8_t      ip_p;           /* protocol */
  65         nd_uint16_t     ip_sum;         /* checksum */
  66         nd_ipv4         ip_src,ip_dst;  /* source and dest address */
  67 };
  68
  69 #define IP_MAXPACKET    65535           /* maximum packet size */
  70
  71 /*
  72  * Definitions for IP type of service (ip_tos)
  73  */
  74 #define IPTOS_LOWDELAY          0x10
  75 #define IPTOS_THROUGHPUT        0x08
  76 #define IPTOS_RELIABILITY       0x04
  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_RFC1393           82              /* traceroute RFC 1393 */
 108 #define IPOPT_SECURITY          130             /* provide s,c,h,tcc */
 109 #define IPOPT_LSRR              131             /* loose source route */
 110 #define IPOPT_SSRR              137             /* strict source route */
 111 #define IPOPT_RA                148             /* router-alert, rfc2113 */
 112
 113 /*
 114  * Offsets to fields in options other than EOL and NOP.
 115  */
 116 #define IPOPT_OPTVAL            0               /* option ID */
 117 #define IPOPT_OLEN              1               /* option length */
 118 #define IPOPT_OFFSET            2               /* offset within option */
 119 #define IPOPT_MINOFF            4               /* min value of above */
 120
 121 /*
 122  * Time stamp option structure.
 123  */
 124 struct  ip_timestamp {
 125         nd_uint8_t      ipt_code;       /* IPOPT_TS */
 126         nd_uint8_t      ipt_len;        /* size of structure (variable) */
 127         nd_uint8_t      ipt_ptr;        /* index of current entry */
 128         nd_uint8_t      ipt_oflwflg;    /* flags, overflow counter */
 129 #define IPTS_OFLW(ip)   (((ipt)->ipt_oflwflg & 0xf0) >> 4)
 130 #define IPTS_FLG(ip)    ((ipt)->ipt_oflwflg & 0x0f)
 131         union ipt_timestamp {
 132                 nd_uint32_t ipt_time[1];
 133                 struct  ipt_ta {
 134                         nd_ipv4 ipt_addr;
 135                         nd_uint32_t ipt_time;
 136                 } ipt_ta[1];
 137         } ipt_timestamp;
 138 };
 139
 140 /* flag bits for ipt_flg */
 141 #define IPOPT_TS_TSONLY         0               /* timestamps only */
 142 #define IPOPT_TS_TSANDADDR      1               /* timestamps and addresses */
 143 #define IPOPT_TS_PRESPEC        3               /* specified modules only */
 144
 145 /* bits for security (not byte swapped) */
 146 #define IPOPT_SECUR_UNCLASS     0x0000
 147 #define IPOPT_SECUR_CONFID      0xf135
 148 #define IPOPT_SECUR_EFTO        0x789a
 149 #define IPOPT_SECUR_MMMM        0xbc4d
 150 #define IPOPT_SECUR_RESTR       0xaf13
 151 #define IPOPT_SECUR_SECRET      0xd788
 152 #define IPOPT_SECUR_TOPSECRET   0x6bc5
 153
 154 /*
 155  * Internet implementation parameters.
 156  */
 157 #define MAXTTL          255             /* maximum time to live (seconds) */
 158 #define IPDEFTTL        64              /* default ttl, from RFC 1340 */
 159 #define IPFRAGTTL       60              /* time to live for frags, slowhz */
 160 #define IPTTLDEC        1               /* subtracted when forwarding */
 161
 162 #define IP_MSS          576             /* default maximum segment size */
 163 #endif /* netdissect_ip_h */