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 /* 37 * Definitions for internet protocol version 4. 38 * Per RFC 791, September 1981. 39 */ 40 #define IPVERSION 4 41 42 /* 43 * Structure of an internet header, naked of options. 44 * 45 * We declare ip_len and ip_off to be short, rather than u_short 46 * pragmatically since otherwise unsigned comparisons can result 47 * against negative integers quite easily, and fail in subtle ways. 48 */ 49 struct ip { 50 #if BYTE_ORDER == LITTLE_ENDIAN 51 u_char ip_hl:4, /* header length */ 52 ip_v:4; /* version */ 53 #endif 54 #if BYTE_ORDER == BIG_ENDIAN 55 u_char ip_v:4, /* version */ 56 ip_hl:4; /* header length */ 57 #endif 58 u_char ip_tos; /* type of service */ 59 short ip_len; /* total length */ 60 u_short ip_id; /* identification */ 61 short ip_off; /* fragment offset field */ 62 #define IP_DF 0x4000 /* dont fragment flag */ 63 #define IP_MF 0x2000 /* more fragments flag */ 64 #define IP_OFFMASK 0x1fff /* mask for fragmenting bits */ 65 u_char ip_ttl; /* time to live */ 66 u_char ip_p; /* protocol */ 67 u_short ip_sum; /* checksum */ 68 struct in_addr ip_src,ip_dst; /* source and dest address */ 69 }; 70 71 #define IP_MAXPACKET 65535 /* maximum packet size */ 72 73 /* 74 * Definitions for IP type of service (ip_tos) 75 */ 76 #define IPTOS_LOWDELAY 0x10 77 #define IPTOS_THROUGHPUT 0x08 78 #define IPTOS_RELIABILITY 0x04 79 80 /* 81 * Definitions for IP precedence (also in ip_tos) (hopefully unused) 82 */ 83 #define IPTOS_PREC_NETCONTROL 0xe0 84 #define IPTOS_PREC_INTERNETCONTROL 0xc0 85 #define IPTOS_PREC_CRITIC_ECP 0xa0 86 #define IPTOS_PREC_FLASHOVERRIDE 0x80 87 #define IPTOS_PREC_FLASH 0x60 88 #define IPTOS_PREC_IMMEDIATE 0x40 89 #define IPTOS_PREC_PRIORITY 0x20 90 #define IPTOS_PREC_ROUTINE 0x00 91 92 /* 93 * Definitions for options. 94 */ 95 #define IPOPT_COPIED(o) ((o)&0x80) 96 #define IPOPT_CLASS(o) ((o)&0x60) 97 #define IPOPT_NUMBER(o) ((o)&0x1f) 98 99 #define IPOPT_CONTROL 0x00 100 #define IPOPT_RESERVED1 0x20 101 #define IPOPT_DEBMEAS 0x40 102 #define IPOPT_RESERVED2 0x60 103 104 #define IPOPT_EOL 0 /* end of option list */ 105 #define IPOPT_NOP 1 /* no operation */ 106 107 #define IPOPT_RR 7 /* record packet route */ 108 #define IPOPT_TS 68 /* timestamp */ 109 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 110 #define IPOPT_LSRR 131 /* loose source route */ 111 #define IPOPT_SATID 136 /* satnet id */ 112 #define IPOPT_SSRR 137 /* strict source route */ 113 114 /* 115 * Offsets to fields in options other than EOL and NOP. 116 */ 117 #define IPOPT_OPTVAL 0 /* option ID */ 118 #define IPOPT_OLEN 1 /* option length */ 119 #define IPOPT_OFFSET 2 /* offset within option */ 120 #define IPOPT_MINOFF 4 /* min value of above */ 121 122 /* 123 * Time stamp option structure. 124 */ 125 struct ip_timestamp { 126 u_char ipt_code; /* IPOPT_TS */ 127 u_char ipt_len; /* size of structure (variable) */ 128 u_char ipt_ptr; /* index of current entry */ 129 #if BYTE_ORDER == LITTLE_ENDIAN 130 u_char ipt_flg:4, /* flags, see below */ 131 ipt_oflw:4; /* overflow counter */ 132 #endif 133 #if BYTE_ORDER == BIG_ENDIAN 134 u_char ipt_oflw:4, /* overflow counter */ 135 ipt_flg:4; /* flags, see below */ 136 #endif 137 union ipt_timestamp { 138 n_long ipt_time[1]; 139 struct ipt_ta { 140 struct in_addr ipt_addr; 141 n_long ipt_time; 142 } ipt_ta[1]; 143 } ipt_timestamp; 144 }; 145 146 /* flag bits for ipt_flg */ 147 #define IPOPT_TS_TSONLY 0 /* timestamps only */ 148 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 149 #define IPOPT_TS_PRESPEC 3 /* specified modules only */ 150 151 /* bits for security (not byte swapped) */ 152 #define IPOPT_SECUR_UNCLASS 0x0000 153 #define IPOPT_SECUR_CONFID 0xf135 154 #define IPOPT_SECUR_EFTO 0x789a 155 #define IPOPT_SECUR_MMMM 0xbc4d 156 #define IPOPT_SECUR_RESTR 0xaf13 157 #define IPOPT_SECUR_SECRET 0xd788 158 #define IPOPT_SECUR_TOPSECRET 0x6bc5 159 160 /* 161 * Internet implementation parameters. 162 */ 163 #define MAXTTL 255 /* maximum time to live (seconds) */ 164 #define IPDEFTTL 64 /* default ttl, from RFC 1340 */ 165 #define IPFRAGTTL 60 /* time to live for frags, slowhz */ 166 #define IPTTLDEC 1 /* subtracted when forwarding */ 167 168 #define IP_MSS 576 /* default maximum segment size */ 169