1 /* ip.h 1.9 81/11/18 */ 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 u_char ip_hl:4, /* header length */ 18 ip_v:4; /* version */ 19 u_char ip_tos; /* type of service */ 20 short ip_len; /* total length */ 21 u_short ip_id; /* identification */ 22 short ip_off; /* fragment offset field */ 23 #define IP_DF 0x4000 /* dont fragment flag */ 24 #define IP_MF 0x2000 /* more fragments flag */ 25 u_char ip_ttl; /* time to live */ 26 u_char ip_p; /* protocol */ 27 u_short ip_sum; /* checksum */ 28 struct in_addr ip_src,ip_dst; /* source and dest address */ 29 }; 30 31 /* 32 * Definitions for options. 33 */ 34 #define IPOPT_COPIED(o) ((o)&0x80) 35 #define IPOPT_CLASS(o) ((o)&0x40) 36 #define IPOPT_NUMBER(o) ((o)&0x3f) 37 38 #define IPOPT_CONTROL 0x00 39 #define IPOPT_RESERVED1 0x10 40 #define IPOPT_DEBMEAS 0x20 41 #define IPOPT_RESERVED2 0x30 42 43 #define IPOPT_EOL 0 /* end of option list */ 44 #define IPOPT_NOP 1 /* no operation */ 45 46 #define IPOPT_RR 7 /* record packet route */ 47 #define IPOPT_TS 68 /* timestamp */ 48 #define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 49 #define IPOPT_LSRR 131 /* loose source route */ 50 #define IPOPT_SATID 136 /* satnet id */ 51 #define IPOPT_SSRR 137 /* strict source route */ 52 53 /* 54 * Time stamp option structure. 55 */ 56 struct ip_timestamp { 57 u_char ipt_code; /* IPOPT_TS */ 58 u_char ipt_len; /* size of structure (variable) */ 59 u_char ipt_ptr; /* index of current entry */ 60 u_char ipt_flg:4, /* flags, see below */ 61 ipt_oflw:4; /* overflow counter */ 62 union { 63 n_long ipt_time[1]; 64 struct ipt_ta { 65 struct in_addr ipt_addr; 66 n_long ipt_time; 67 } ipt_ta[1]; 68 } 69 }; 70 71 /* flag bits for ipt_flg */ 72 #define IPOPT_TS_TSONLY 0 /* timestamps only */ 73 #define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 74 #define IPOPT_TS_PRESPEC 2 /* specified modules only */ 75 76 /* bits for security (not byte swapped) */ 77 #define IPOPT_SECUR_UNCLASS 0x0000 78 #define IPOPT_SECUR_CONFID 0xf135 79 #define IPOPT_SECUR_EFTO 0x789a 80 #define IPOPT_SECUR_MMMM 0xbc4d 81 #define IPOPT_SECUR_RESTR 0xaf13 82 #define IPOPT_SECUR_SECRET 0xd788 83 #define IPOPT_SECUR_TOPSECRET 0x6bc5 84 85 /* 86 * Internet implementation parameters. 87 */ 88 #define MAXTTL 255 /* maximum time to live (seconds) */ 89 #define IPFRAGTTL 15 /* time to live for frag chains */ 90