1 /* ip.h 1.11 82/12/28 */ 2 3 /* 4 * Definitions for internet protocol version 4. 5 * Per RFC 791, September 1981. 6 */ 7 #define IPVERSION 4 8 9 /* 10 * Structure of an internet header, naked of options. 11 * 12 * We declare ip_len and ip_off to be short, rather than u_short 13 * pragmatically since otherwise unsigned comparisons can result 14 * against negative integers quite easily, and fail in subtle ways. 15 */ 16 struct ip { 17 #ifdef vax 18 u_char ip_hl:4, /* header length */ 19 ip_v:4; /* version */ 20 #endif 21 #ifdef sun 22 u_char ip_v:4, /* version */ 23 ip_hl:4; /* header length */ 24 #endif 25 u_char ip_tos; /* type of service */ 26 short ip_len; /* total length */ 27 u_short ip_id; /* identification */ 28 short ip_off; /* fragment offset field */ 29 #define IP_DF 0x4000 /* dont fragment flag */ 30 #define IP_MF 0x2000 /* more fragments flag */ 31 u_char ip_ttl; /* time to live */ 32 u_char ip_p; /* protocol */ 33 u_short ip_sum; /* checksum */ 34 struct in_addr ip_src,ip_dst; /* source and dest address */ 35 }; 36 37 /* 38 * Definitions for options. 39 */ 40 #define IPOPT_COPIED(o) ((o)&0x80) 41 #define IPOPT_CLASS(o) ((o)&0x40) 42 #define IPOPT_NUMBER(o) ((o)&0x3f) 43 44 #define IPOPT_CONTROL 0x00 45 #define IPOPT_RESERVED1 0x10 46 #define IPOPT_DEBMEAS 0x20 47 #define IPOPT_RESERVED2 0x30 48 49 #define IPOPT_EOL 0 /* end of option list */ 50 #define IPOPT_NOP 1 /* no operation */ 51 52 #define IPOPT_RR 7 /* record packet route */ 53 #define IPOPT_TS 68 /* timestamp */ 54 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 55 #define IPOPT_LSRR 131 /* loose source route */ 56 #define IPOPT_SATID 136 /* satnet id */ 57 #define IPOPT_SSRR 137 /* strict source route */ 58 59 /* 60 * Time stamp option structure. 61 */ 62 struct ip_timestamp { 63 u_char ipt_code; /* IPOPT_TS */ 64 u_char ipt_len; /* size of structure (variable) */ 65 u_char ipt_ptr; /* index of current entry */ 66 u_char ipt_flg:4, /* flags, see below */ 67 ipt_oflw:4; /* overflow counter */ 68 union { 69 n_long ipt_time[1]; 70 struct ipt_ta { 71 struct in_addr ipt_addr; 72 n_long ipt_time; 73 } ipt_ta[1]; 74 } 75 }; 76 77 /* flag bits for ipt_flg */ 78 #define IPOPT_TS_TSONLY 0 /* timestamps only */ 79 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 80 #define IPOPT_TS_PRESPEC 2 /* specified modules only */ 81 82 /* bits for security (not byte swapped) */ 83 #define IPOPT_SECUR_UNCLASS 0x0000 84 #define IPOPT_SECUR_CONFID 0xf135 85 #define IPOPT_SECUR_EFTO 0x789a 86 #define IPOPT_SECUR_MMMM 0xbc4d 87 #define IPOPT_SECUR_RESTR 0xaf13 88 #define IPOPT_SECUR_SECRET 0xd788 89 #define IPOPT_SECUR_TOPSECRET 0x6bc5 90 91 /* 92 * Internet implementation parameters. 93 */ 94 #define MAXTTL 255 /* maximum time to live (seconds) */ 95 #define IPFRAGTTL 15 /* time to live for frag chains */ 96 #define IPTTLDEC 5 /* subtracted when forwarding */ 97