1 /* 2 * Copyright (c) 1982, 1986 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 * 17 * @(#)ip.h 7.6.1.3 (Berkeley) 02/20/89 18 */ 19 #ifndef BYTE_ORDER 20 /* 21 * Definitions for byte order, 22 * according to byte significance from low address to high. 23 */ 24 #define LITTLE_ENDIAN 1234 /* least-significant byte first (vax) */ 25 #define BIG_ENDIAN 4321 /* most-significant byte first (IBM, net) */ 26 #define PDP_ENDIAN 3412 /* LSB first in word, MSW first in long (pdp) */ 27 28 #ifdef vax 29 #define BYTE_ORDER LITTLE_ENDIAN 30 #else 31 #define BYTE_ORDER BIG_ENDIAN /* mc68000, tahoe, most others */ 32 #endif 33 #endif BYTE_ORDER 34 35 /* 36 * Definitions for internet protocol version 4. 37 * Per RFC 791, September 1981. 38 */ 39 #define IPVERSION 4 40 41 /* 42 * Structure of an internet header, naked of options. 43 * 44 * We declare ip_len and ip_off to be short, rather than u_short 45 * pragmatically since otherwise unsigned comparisons can result 46 * against negative integers quite easily, and fail in subtle ways. 47 */ 48 struct ip { 49 #if BYTE_ORDER == LITTLE_ENDIAN 50 u_char ip_hl:4, /* header length */ 51 ip_v:4; /* version */ 52 #endif 53 #if BYTE_ORDER == BIG_ENDIAN 54 u_char ip_v:4, /* version */ 55 ip_hl:4; /* header length */ 56 #endif 57 u_char ip_tos; /* type of service */ 58 short ip_len; /* total length */ 59 u_short ip_id; /* identification */ 60 short ip_off; /* fragment offset field */ 61 #define IP_DF 0x4000 /* dont fragment flag */ 62 #define IP_MF 0x2000 /* more fragments flag */ 63 u_char ip_ttl; /* time to live */ 64 u_char ip_p; /* protocol */ 65 u_short ip_sum; /* checksum */ 66 struct in_addr ip_src,ip_dst; /* source and dest address */ 67 }; 68 69 #define IP_MAXPACKET 65535 /* maximum packet size */ 70 71 /* 72 * Definitions for options. 73 */ 74 #define IPOPT_COPIED(o) ((o)&0x80) 75 #define IPOPT_CLASS(o) ((o)&0x60) 76 #define IPOPT_NUMBER(o) ((o)&0x1f) 77 78 #define IPOPT_CONTROL 0x00 79 #define IPOPT_RESERVED1 0x20 80 #define IPOPT_DEBMEAS 0x40 81 #define IPOPT_RESERVED2 0x60 82 83 #define IPOPT_EOL 0 /* end of option list */ 84 #define IPOPT_NOP 1 /* no operation */ 85 86 #define IPOPT_RR 7 /* record packet route */ 87 #define IPOPT_TS 68 /* timestamp */ 88 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 89 #define IPOPT_LSRR 131 /* loose source route */ 90 #define IPOPT_SATID 136 /* satnet id */ 91 #define IPOPT_SSRR 137 /* strict source route */ 92 93 /* 94 * Offsets to fields in options other than EOL and NOP. 95 */ 96 #define IPOPT_OPTVAL 0 /* option ID */ 97 #define IPOPT_OLEN 1 /* option length */ 98 #define IPOPT_OFFSET 2 /* offset within option */ 99 #define IPOPT_MINOFF 4 /* min value of above */ 100 101 /* 102 * Time stamp option structure. 103 */ 104 struct ip_timestamp { 105 u_char ipt_code; /* IPOPT_TS */ 106 u_char ipt_len; /* size of structure (variable) */ 107 u_char ipt_ptr; /* index of current entry */ 108 #if BYTE_ORDER == LITTLE_ENDIAN 109 u_char ipt_flg:4, /* flags, see below */ 110 ipt_oflw:4; /* overflow counter */ 111 #endif 112 #if BYTE_ORDER == BIG_ENDIAN 113 u_char ipt_oflw:4, /* overflow counter */ 114 ipt_flg:4; /* flags, see below */ 115 #endif 116 union ipt_timestamp { 117 n_long ipt_time[1]; 118 struct ipt_ta { 119 struct in_addr ipt_addr; 120 n_long ipt_time; 121 } ipt_ta[1]; 122 } ipt_timestamp; 123 }; 124 125 /* flag bits for ipt_flg */ 126 #define IPOPT_TS_TSONLY 0 /* timestamps only */ 127 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 128 #define IPOPT_TS_PRESPEC 3 /* specified modules only */ 129 130 /* bits for security (not byte swapped) */ 131 #define IPOPT_SECUR_UNCLASS 0x0000 132 #define IPOPT_SECUR_CONFID 0xf135 133 #define IPOPT_SECUR_EFTO 0x789a 134 #define IPOPT_SECUR_MMMM 0xbc4d 135 #define IPOPT_SECUR_RESTR 0xaf13 136 #define IPOPT_SECUR_SECRET 0xd788 137 #define IPOPT_SECUR_TOPSECRET 0x6bc5 138 139 /* 140 * Internet implementation parameters. 141 */ 142 #define MAXTTL 255 /* maximum time to live (seconds) */ 143 #define IPFRAGTTL 60 /* time to live for frags, slowhz */ 144 #define IPTTLDEC 1 /* subtracted when forwarding */ 145 146 #define IP_MSS 576 /* default maximum segment size */ 147