contrib/tcpdump-3.8.3/ip.h

   1 /* @(#) $Header: /tcpdump/master/tcpdump/ip.h,v 1.10 2002/12/11 07:13:53 guy Exp $ (LBL) */
   2 /*
   3  * Copyright (c) 1982, 1986, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)ip.h        8.2 (Berkeley) 6/1/94
  35  */
  36
  37 /*
  38  * Definitions for internet protocol version 4.
  39  * Per RFC 791, September 1981.
  40  */
  41 #define IPVERSION       4
  42
  43 /*
  44  * Structure of an internet header, naked of options.
  45  *
  46  * We declare ip_len and ip_off to be short, rather than u_short
  47  * pragmatically since otherwise unsigned comparisons can result
  48  * against negative integers quite easily, and fail in subtle ways.
  49  */
  50 struct ip {
  51         u_int8_t        ip_vhl;         /* header length, version */
  52 #define IP_V(ip)        (((ip)->ip_vhl & 0xf0) >> 4)
  53 #define IP_HL(ip)       ((ip)->ip_vhl & 0x0f)
  54         u_int8_t        ip_tos;         /* type of service */
  55         u_int16_t       ip_len;         /* total length */
  56         u_int16_t       ip_id;          /* identification */
  57         u_int16_t       ip_off;         /* fragment offset field */
  58 #define IP_DF 0x4000                    /* dont fragment flag */
  59 #define IP_MF 0x2000                    /* more fragments flag */
  60 #define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
  61         u_int8_t        ip_ttl;         /* time to live */
  62         u_int8_t        ip_p;           /* protocol */
  63         u_int16_t       ip_sum;         /* checksum */
  64         struct  in_addr ip_src,ip_dst;  /* source and dest address */
  65 };
  66
  67 #define IP_MAXPACKET    65535           /* maximum packet size */
  68
  69 /*
  70  * Definitions for IP type of service (ip_tos)
  71  */
  72 #define IPTOS_LOWDELAY          0x10
  73 #define IPTOS_THROUGHPUT        0x08
  74 #define IPTOS_RELIABILITY       0x04
  75
  76 /*
  77  * Definitions for IP precedence (also in ip_tos) (hopefully unused)
  78  */
  79 #define IPTOS_PREC_NETCONTROL           0xe0
  80 #define IPTOS_PREC_INTERNETCONTROL      0xc0
  81 #define IPTOS_PREC_CRITIC_ECP           0xa0
  82 #define IPTOS_PREC_FLASHOVERRIDE        0x80
  83 #define IPTOS_PREC_FLASH                0x60
  84 #define IPTOS_PREC_IMMEDIATE            0x40
  85 #define IPTOS_PREC_PRIORITY             0x20
  86 #define IPTOS_PREC_ROUTINE              0x00
  87
  88 /*
  89  * Definitions for options.
  90  */
  91 #define IPOPT_COPIED(o)         ((o)&0x80)
  92 #define IPOPT_CLASS(o)          ((o)&0x60)
  93 #define IPOPT_NUMBER(o)         ((o)&0x1f)
  94
  95 #define IPOPT_CONTROL           0x00
  96 #define IPOPT_RESERVED1         0x20
  97 #define IPOPT_DEBMEAS           0x40
  98 #define IPOPT_RESERVED2         0x60
  99
 100 #define IPOPT_EOL               0               /* end of option list */
 101 #define IPOPT_NOP               1               /* no operation */
 102
 103 #define IPOPT_RR                7               /* record packet route */
 104 #define IPOPT_TS                68              /* timestamp */
 105 #define IPOPT_SECURITY          130             /* provide s,c,h,tcc */
 106 #define IPOPT_LSRR              131             /* loose source route */
 107 #define IPOPT_SATID             136             /* satnet id */
 108 #define IPOPT_SSRR              137             /* strict source route */
 109
 110 /*
 111  * Offsets to fields in options other than EOL and NOP.
 112  */
 113 #define IPOPT_OPTVAL            0               /* option ID */
 114 #define IPOPT_OLEN              1               /* option length */
 115 #define IPOPT_OFFSET            2               /* offset within option */
 116 #define IPOPT_MINOFF            4               /* min value of above */
 117
 118 /*
 119  * Time stamp option structure.
 120  */
 121 struct  ip_timestamp {
 122         u_int8_t        ipt_code;       /* IPOPT_TS */
 123         u_int8_t        ipt_len;        /* size of structure (variable) */
 124         u_int8_t        ipt_ptr;        /* index of current entry */
 125         u_int8_t        ipt_oflwflg;    /* flags, overflow counter */
 126 #define IPTS_OFLW(ip)   (((ipt)->ipt_oflwflg & 0xf0) >> 4)
 127 #define IPTS_FLG(ip)    ((ipt)->ipt_oflwflg & 0x0f)
 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 */
 160
 161 /* in print-ip.c */
 162 extern u_int32_t ip_finddst(const struct ip *);