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 this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific prior written permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 * 12 * @(#)ip.h 7.6.1.1 (Berkeley) 03/15/88 13 */ 14 #ifndef BYTE_ORDER 15 /* 16 * Definitions for byte order, 17 * according to byte significance from low address to high. 18 */ 19 #define LITTLE_ENDIAN 1234 /* least-significant byte first (vax) */ 20 #define BIG_ENDIAN 4321 /* most-significant byte first (IBM, net) */ 21 #define PDP_ENDIAN 3412 /* LSB first in word, MSW first in long (pdp) */ 22 23 #ifdef vax 24 #define BYTE_ORDER LITTLE_ENDIAN 25 #else 26 #define BYTE_ORDER BIG_ENDIAN /* mc68000, tahoe, most others */ 27 #endif 28 #endif BYTE_ORDER 29 30 /* 31 * Definitions for internet protocol version 4. 32 * Per RFC 791, September 1981. 33 */ 34 #define IPVERSION 4 35 36 /* 37 * Structure of an internet header, naked of options. 38 * 39 * We declare ip_len and ip_off to be short, rather than u_short 40 * pragmatically since otherwise unsigned comparisons can result 41 * against negative integers quite easily, and fail in subtle ways. 42 */ 43 struct ip { 44 #if BYTE_ORDER == LITTLE_ENDIAN 45 u_char ip_hl:4, /* header length */ 46 ip_v:4; /* version */ 47 #endif 48 #if BYTE_ORDER == BIG_ENDIAN 49 u_char ip_v:4, /* version */ 50 ip_hl:4; /* header length */ 51 #endif 52 u_char ip_tos; /* type of service */ 53 short ip_len; /* total length */ 54 u_short ip_id; /* identification */ 55 short ip_off; /* fragment offset field */ 56 #define IP_DF 0x4000 /* dont fragment flag */ 57 #define IP_MF 0x2000 /* more fragments flag */ 58 u_char ip_ttl; /* time to live */ 59 u_char ip_p; /* protocol */ 60 u_short ip_sum; /* checksum */ 61 struct in_addr ip_src,ip_dst; /* source and dest address */ 62 }; 63 64 #define IP_MAXPACKET 65535 /* maximum packet size */ 65 66 /* 67 * Definitions for options. 68 */ 69 #define IPOPT_COPIED(o) ((o)&0x80) 70 #define IPOPT_CLASS(o) ((o)&0x60) 71 #define IPOPT_NUMBER(o) ((o)&0x1f) 72 73 #define IPOPT_CONTROL 0x00 74 #define IPOPT_RESERVED1 0x20 75 #define IPOPT_DEBMEAS 0x40 76 #define IPOPT_RESERVED2 0x60 77 78 #define IPOPT_EOL 0 /* end of option list */ 79 #define IPOPT_NOP 1 /* no operation */ 80 81 #define IPOPT_RR 7 /* record packet route */ 82 #define IPOPT_TS 68 /* timestamp */ 83 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 84 #define IPOPT_LSRR 131 /* loose source route */ 85 #define IPOPT_SATID 136 /* satnet id */ 86 #define IPOPT_SSRR 137 /* strict source route */ 87 88 /* 89 * Offsets to fields in options other than EOL and NOP. 90 */ 91 #define IPOPT_OPTVAL 0 /* option ID */ 92 #define IPOPT_OLEN 1 /* option length */ 93 #define IPOPT_OFFSET 2 /* offset within option */ 94 #define IPOPT_MINOFF 4 /* min value of above */ 95 96 /* 97 * Time stamp option structure. 98 */ 99 struct ip_timestamp { 100 u_char ipt_code; /* IPOPT_TS */ 101 u_char ipt_len; /* size of structure (variable) */ 102 u_char ipt_ptr; /* index of current entry */ 103 #if BYTE_ORDER == LITTLE_ENDIAN 104 u_char ipt_flg:4, /* flags, see below */ 105 ipt_oflw:4; /* overflow counter */ 106 #endif 107 #if BYTE_ORDER == BIG_ENDIAN 108 u_char ipt_oflw:4, /* overflow counter */ 109 ipt_flg:4; /* flags, see below */ 110 #endif 111 union ipt_timestamp { 112 n_long ipt_time[1]; 113 struct ipt_ta { 114 struct in_addr ipt_addr; 115 n_long ipt_time; 116 } ipt_ta[1]; 117 } ipt_timestamp; 118 }; 119 120 /* flag bits for ipt_flg */ 121 #define IPOPT_TS_TSONLY 0 /* timestamps only */ 122 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 123 #define IPOPT_TS_PRESPEC 2 /* specified modules only */ 124 125 /* bits for security (not byte swapped) */ 126 #define IPOPT_SECUR_UNCLASS 0x0000 127 #define IPOPT_SECUR_CONFID 0xf135 128 #define IPOPT_SECUR_EFTO 0x789a 129 #define IPOPT_SECUR_MMMM 0xbc4d 130 #define IPOPT_SECUR_RESTR 0xaf13 131 #define IPOPT_SECUR_SECRET 0xd788 132 #define IPOPT_SECUR_TOPSECRET 0x6bc5 133 134 /* 135 * Internet implementation parameters. 136 */ 137 #define MAXTTL 255 /* maximum time to live (seconds) */ 138 #define IPFRAGTTL 60 /* time to live for frags, slowhz */ 139 #define IPTTLDEC 1 /* subtracted when forwarding */ 140 141 #define IP_MSS 576 /* default maximum segment size */ 142