ntpdate.h revision 290001 
1/*
2 * ntpdate.h - declarations for the ntpdate and ntptimeset programs
3 */
4
5#include "ntp_malloc.h"
6
7extern void	loadservers	(char *cfgpath);
8
9/*
10 * The server structure is a much simplified version of the
11 * peer structure, for ntpdate's use.  Since we always send
12 * in client mode and expect to receive in server mode, this
13 * leaves only a very limited number of things we need to
14 * remember about the server.
15 */
16struct server {
17	struct server *next_server;	/* next server in build list */
18	sockaddr_u srcadr;		/* address of remote host */
19	u_char version;			/* version to use */
20	u_char leap;			/* leap indicator */
21	u_char stratum;			/* stratum of remote server */
22	s_char precision;		/* server's clock precision */
23	u_char trust;			/* trustability of the filtered data */
24	u_fp rootdelay;			/* distance from primary clock */
25	u_fp rootdisp;			/* peer clock dispersion */
26	u_int32 refid;			/* peer reference ID */
27	l_fp reftime;			/* time of peer's last update */
28	u_long event_time;		/* time for next timeout */
29	u_long last_xmit;		/* time of last transmit */
30	u_short xmtcnt;			/* number of packets transmitted */
31	u_short rcvcnt;			/* number of packets received */
32	u_char reach;			/* reachability, NTP_WINDOW bits */
33	u_short filter_nextpt;		/* index into filter shift register */
34	s_fp filter_delay[NTP_SHIFT];	/* delay part of shift register */
35	l_fp filter_offset[NTP_SHIFT];	/* offset part of shift register */
36	s_fp filter_soffset[NTP_SHIFT]; /* offset in s_fp format, for disp */
37	u_fp filter_error[NTP_SHIFT];	/* error part of shift register */
38	l_fp org;			/* peer's originate time stamp */
39	l_fp xmt;			/* transmit time stamp */
40	u_fp delay;			/* filter estimated delay */
41	u_fp dispersion;		/* filter estimated dispersion */
42	l_fp offset;			/* filter estimated clock offset */
43	s_fp soffset;			/* fp version of above */
44};
45
46
47/*
48 * ntpdate runs everything on a simple, short timeout.  It sends a
49 * packet and sets the timeout (by default, to a small value suitable
50 * for a LAN).  If it receives a response it sends another request.
51 * If it times out it shifts zeroes into the filter and sends another
52 * request.
53 *
54 * The timer routine is run often (once every 1/5 second currently)
55 * so that time outs are done with reasonable precision.
56 */
57#define TIMER_HZ	(5)		/* 5 per second */
58
59/*
60 * ntpdate will make a long adjustment using adjtime() if the times
61 * are close, or step the time if the times are farther apart.  The
62 * following defines what is "close".
63 */
64#define	NTPDATE_THRESHOLD	(FP_SECOND >> 1)	/* 1/2 second */
65
66#define NTP_MAXAGE	86400	/* one day in seconds */
67
68/*
69 * When doing adjustments, ntpdate actually overadjusts (currently
70 * by 50%, though this may change).  While this will make it take longer
71 * to reach a steady state condition, it will typically result in
72 * the clock keeping more accurate time, on average.  The amount of
73 * overshoot is limited.
74 */
75#ifdef	NOTNOW
76#define	ADJ_OVERSHOOT	1/2	/* this is hard coded */
77#endif	/* NOTNOW */
78#define	ADJ_MAXOVERSHOOT	0x10000000	/* 50 ms as a ts fraction */
79
80/*
81 * Since ntpdate isn't aware of some of the things that normally get
82 * put in an NTP packet, we fix some values.
83 */
84#define	NTPDATE_PRECISION	(-6)		/* use this precision */
85#define	NTPDATE_DISTANCE	FP_SECOND	/* distance is 1 sec */
86#define	NTPDATE_DISP		FP_SECOND	/* so is the dispersion */
87#define	NTPDATE_REFID		(0)		/* reference ID to use */
88#define PEER_MAXDISP	(64*FP_SECOND)	/* maximum dispersion (fp 64) */
89
90
91/*
92 * No less than 2s between requests to a server to stay within ntpd's
93 * default "discard minimum 1" (and 1s enforcement slop).  That is
94 * enforced only if the nondefault limited restriction is in place, such
95 * as with "restrict ... limited" and "restrict ... kod limited".
96 */
97#define	MINTIMEOUT	(1 * TIMER_HZ)	/* 1s min. between packets */
98#define	DEFTIMEOUT	(2 * TIMER_HZ)	/* 2s by default */
99#define	DEFSAMPLES	4		/* get 4 samples per server */
100#define	DEFPRECISION	(-5)		/* the precision we claim */
101#define	DEFMAXPERIOD	60		/* maximum time to wait */
102#define	DEFMINSERVERS	3		/* minimum responding servers */
103#define	DEFMINVALID	1		/* mimimum servers with valid time */
104
105/*
106 * Define the max number of sockets we can open
107 */
108#define MAX_AF 2
109