1 /* 2 * ntpdate.h - declarations for the ntpdate and ntptimeset programs 3 */ 4 5 #include "ntp_malloc.h" 6 7 /* 8 * The server structure is a much simplified version of the 9 * peer structure, for ntpdate's use. Since we always send 10 * in client mode and expect to receive in server mode, this 11 * leaves only a very limited number of things we need to 12 * remember about the server. 13 */ 14 struct server { 15 struct server *next_server; /* next server in build list */ 16 struct sockaddr_in srcadr; /* address of remote host */ 17 u_char version; /* version to use */ 18 u_char leap; /* leap indicator */ 19 u_char stratum; /* stratum of remote server */ 20 s_char precision; /* server's clock precision */ 21 u_char trust; /* trustability of the filtered data */ 22 u_fp rootdelay; /* distance from primary clock */ 23 u_fp rootdispersion; /* peer clock dispersion */ 24 u_int32 refid; /* peer reference ID */ 25 l_fp reftime; /* time of peer's last update */ 26 u_long event_time; /* time for next timeout */ 27 u_long last_xmit; /* time of last transmit */ 28 u_short xmtcnt; /* number of packets transmitted */ 29 u_short rcvcnt; /* number of packets received */ 30 u_char reach; /* reachability, NTP_WINDOW bits */ 31 u_short filter_nextpt; /* index into filter shift register */ 32 s_fp filter_delay[NTP_SHIFT]; /* delay part of shift register */ 33 l_fp filter_offset[NTP_SHIFT]; /* offset part of shift register */ 34 s_fp filter_soffset[NTP_SHIFT]; /* offset in s_fp format, for disp */ 35 u_fp filter_error[NTP_SHIFT]; /* error part of shift register */ 36 l_fp org; /* peer's originate time stamp */ 37 l_fp xmt; /* transmit time stamp */ 38 u_fp delay; /* filter estimated delay */ 39 u_fp dispersion; /* filter estimated dispersion */ 40 l_fp offset; /* filter estimated clock offset */ 41 s_fp soffset; /* fp version of above */ 42 }; 43 44 45 /* 46 * ntpdate runs everything on a simple, short timeout. It sends a 47 * packet and sets the timeout (by default, to a small value suitable 48 * for a LAN). If it receives a response it sends another request. 49 * If it times out it shifts zeroes into the filter and sends another 50 * request. 51 * 52 * The timer routine is run often (once every 1/5 second currently) 53 * so that time outs are done with reasonable precision. 54 */ 55 #define TIMER_HZ (5) /* 5 per second */ 56 57 /* 58 * ntpdate will make a long adjustment using adjtime() if the times 59 * are close, or step the time if the times are farther apart. The 60 * following defines what is "close". 61 */ 62 #define NTPDATE_THRESHOLD (FP_SECOND >> 1) /* 1/2 second */ 63 64 /* 65 * When doing adjustments, ntpdate actually overadjusts (currently 66 * by 50%, though this may change). While this will make it take longer 67 * to reach a steady state condition, it will typically result in 68 * the clock keeping more accurate time, on average. The amount of 69 * overshoot is limited. 70 */ 71 #ifdef NOTNOW 72 #define ADJ_OVERSHOOT 1/2 /* this is hard coded */ 73 #endif /* NOTNOW */ 74 #define ADJ_MAXOVERSHOOT 0x10000000 /* 50 ms as a ts fraction */ 75 76 /* 77 * Since ntpdate isn't aware of some of the things that normally get 78 * put in an NTP packet, we fix some values. 79 */ 80 #define NTPDATE_PRECISION (-6) /* use this precision */ 81 #define NTPDATE_DISTANCE FP_SECOND /* distance is 1 sec */ 82 #define NTPDATE_DISP FP_SECOND /* so is the dispersion */ 83 #define NTPDATE_REFID (0) /* reference ID to use */ 84 #define PEER_MAXDISP (64*FP_SECOND) /* maximum dispersion (fp 64) */ 85 86 87 /* 88 * Some defaults 89 */ 90 #define DEFTIMEOUT 5 /* 5 timer increments */ 91 #define DEFSAMPLES 4 /* get 4 samples per server */ 92 #define DEFPRECISION (-5) /* the precision we claim */ 93 #define DEFMAXPERIOD 60 /* maximum time to wait */ 94 #define DEFMINSERVERS 3 /* minimum responding servers */ 95 #define DEFMINVALID 1 /* mimimum servers with valid time */ 96