1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/******************************************************************************
* *
* Copyright (c) David L. Mills 1993 *
* *
* Permission to use, copy, modify, and distribute this software and its *
* documentation for any purpose and without fee is hereby granted, provided *
* that the above copyright notice appears in all copies and that both the *
* copyright notice and this permission notice appear in supporting *
* documentation, and that the name University of Delaware not be used in *
* advertising or publicity pertaining to distribution of the software *
* without specific, written prior permission. The University of Delaware *
* makes no representations about the suitability this software for any *
* purpose. It is provided "as is" without express or implied warranty. *
* *
******************************************************************************/
/*
* Modification history timex.h
*
* 28 Nov 93 David L. Mills
* Adjusted parameters to improve stability and increase poll interval
*
* 10 Oct 93 Torsten Duwe
* Changed to ntp_timex.h (#ifdef'd HAVE_SYS_TIMEX_H)
*
* 17 Sep 93 David L. Mills
* Created file
*/
/*
* This header file defines the Network Time Protocol (NTP) interfaces
* for user and daemon application programs. These are implemented using
* private syscalls and data structures and require specific kernel
* support.
*
* NAME
* ntp_gettime - NTP user application interface
*
* SYNOPSIS
* #include <sys/timex.h>
*
* int syscall(SYS_ntp_gettime, tptr)
*
* int SYS_ntp_gettime defined in syscall.h header file
* struct ntptimeval *tptr pointer to ntptimeval structure
*
* NAME
* ntp_adjtime - NTP daemon application interface
*
* SYNOPSIS
* #include <sys/timex.h>
*
* int syscall(SYS_ntp_adjtime, mode, tptr)
*
* int SYS_ntp_adjtime defined in syscall.h header file
* struct timex *tptr pointer to timex structure
*
*/
#ifndef _NTP_TIMEX_H
#define _NTP_TIMEX_H
/*
* Include system timex.h (if appropriate)
*/
#ifdef HAVE_SYS_TIMEX_H
#include <sys/timex.h>
#else /* provide definitions */
#include <sys/syscall.h>
extern int syscall P((int, void *, ...));
#define ntp_gettime(t) syscall(SYS_ntp_gettime, (t))
#define ntp_adjtime(t) syscall(SYS_ntp_adjtime, (t))
/*
* The following defines establish the engineering parameters of the PLL
* model. The HZ variable establishes the timer interrupt frequency, 100 Hz
* for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
* OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
* nearest power of two in order to avoid hardware multiply operations.
*/
#define SHIFT_HZ 7 /* log2(HZ) */
/*
* The SHIFT_KG and SHIFT_KF defines establish the damping of the PLL
* and are chosen by analysis for a slightly underdamped convergence
* characteristic. The MAXTC define establishes the maximum time constant
* of the PLL. With the parameters given and the default time constant of
* zero, the PLL will converge in about 15 minutes.
*/
#define SHIFT_KG 6 /* shift for phase increment */
#define SHIFT_KF 16 /* shift for frequency increment */
#define MAXTC 6 /* maximum time constant (shift) */
/*
* The SHIFT_SCALE define establishes the decimal point of the time_phase
* variable which serves as a an extension to the low-order bits of the
* system clock variable. The SHIFT_UPDATE define establishes the decimal
* point of the time_offset variable which represents the current offset
* with respect to standard time. The SHIFT_USEC define represents 1 us in
* external units (shift), while the FINEUSEC define represents 1 us in
* internal units.
*/
#define SHIFT_SCALE 23 /* shift for phase scale factor */
#define SHIFT_UPDATE (SHIFT_KG + MAXTC) /* shift for offset scale factor */
#define SHIFT_USEC 16 /* shift for 1 us in external units */
#define FINEUSEC (1 << SHIFT_SCALE) /* 1 us in internal units */
/*
* Mode codes (timex.mode)
*/
#define ADJ_OFFSET 0x0001 /* time offset */
#define ADJ_FREQUENCY 0x0002 /* frequency offset */
#define ADJ_MAXERROR 0x0004 /* maximum time error */
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
/*
* Clock command/status codes (timex.status)
*/
#define TIME_OK 0 /* clock synchronized */
#define TIME_INS 1 /* insert leap second */
#define TIME_DEL 2 /* delete leap second */
#define TIME_OOP 3 /* leap second in progress */
#define TIME_BAD 4 /* clock not synchronized */
/*
* NTP user interface - used to read kernel clock values
* Note: maximum error = NTP synch distance = dispersion + delay / 2;
* estimated error = NTP dispersion.
*/
struct ntptimeval {
struct timeval time; /* current time */
long maxerror; /* maximum error (usec) */
long esterror; /* estimated error (usec) */
};
/*
* NTP daemon interface - used to discipline kernel clock oscillator
*/
struct timex {
int mode; /* mode selector */
long offset; /* time offset (usec) */
long frequency; /* frequency offset (scaled ppm) */
long maxerror; /* maximum error (usec) */
long esterror; /* estimated error (usec) */
int status; /* clock command/status */
long time_constant; /* pll time constant */
long precision; /* clock precision (usec) (read only) */
long tolerance; /* clock frequency tolerance (ppm)
* (read only)
*/
};
#endif /* HAVE_SYS_TIMEX_H */
#endif /* _NTP_TIMEX_H */
|
