kern_ntptime.c revision 2893 
1/******************************************************************************
2 *                                                                            *
3 * Copyright (c) David L. Mills 1993, 1994                                    *
4 *                                                                            *
5 * Permission to use, copy, modify, and distribute this software and its      *
6 * documentation for any purpose and without fee is hereby granted, provided  *
7 * that the above copyright notice appears in all copies and that both the    *
8 * copyright notice and this permission notice appear in supporting           *
9 * documentation, and that the name University of Delaware not be used in     *
10 * advertising or publicity pertaining to distribution of the software        *
11 * without specific, written prior permission.  The University of Delaware    *
12 * makes no representations about the suitability this software for any       *
13 * purpose.  It is provided "as is" without express or implied warranty.      *
14 *                                                                            *
15 ******************************************************************************/
16
17/*
18 * Modification history kern_ntptime.c
19 *
20 * 24 Mar 94	David L. Mills
21 *	Revised syscall interface to include new variables for PPS
22 *	time discipline.
23 *
24 * 14 Feb 94	David L. Mills
25 *	Added code for external clock
26 *
27 * 28 Nov 93	David L. Mills
28 *	Revised frequency scaling to conform with adjusted parameters
29 *
30 * 17 Sep 93	David L. Mills
31 *	Created file
32 */
33/*
34 * ntp_gettime(), ntp_adjtime() - precision time interface for SunOS
35 * 4.1.1 and 4.1.3
36 *
37 * These routines consitute the Network Time Protocol (NTP) interfaces
38 * for user and daemon application programs. The ntp_gettime() routine
39 * provides the time, maximum error (synch distance) and estimated error
40 * (dispersion) to client user application programs. The ntp_adjtime()
41 * routine is used by the NTP daemon to adjust the system clock to an
42 * externally derived time. The time offset and related variables set by
43 * this routine are used by hardclock() to adjust the phase and
44 * frequency of the phase-lock loop which controls the system clock.
45 */
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/kernel.h>
49#include <sys/proc.h>
50#include <sys/timex.h>
51#include <vm/vm.h>
52#include <sys/sysctl.h>
53
54/*
55 * The following variables are used by the hardclock() routine in the
56 * kern_clock.c module and are described in that module.
57 */
58extern struct timeval time;	/* kernel time variable */
59extern int time_state;		/* clock state */
60extern int time_status;		/* clock status bits */
61extern long time_offset;	/* time adjustment (us) */
62extern long time_freq;		/* frequency offset (scaled ppm) */
63extern long time_maxerror;	/* maximum error (us) */
64extern long time_esterror;	/* estimated error (us) */
65extern long time_constant;	/* pll time constant */
66extern long time_precision;	/* clock precision (us) */
67extern long time_tolerance;	/* frequency tolerance (scaled ppm) */
68
69#ifdef PPS_SYNC
70/*
71 * The following variables are used only if the PPS signal discipline
72 * is configured in the kernel.
73 */
74extern int pps_shift;		/* interval duration (s) (shift) */
75extern long pps_freq;		/* pps frequency offset (scaled ppm) */
76extern long pps_jitter;		/* pps jitter (us) */
77extern long pps_stabil;		/* pps stability (scaled ppm) */
78extern long pps_jitcnt;		/* jitter limit exceeded */
79extern long pps_calcnt;		/* calibration intervals */
80extern long pps_errcnt;		/* calibration errors */
81extern long pps_stbcnt;		/* stability limit exceeded */
82#endif /* PPS_SYNC */
83
84int
85ntp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
86	   void *newp, size_t newlen, struct proc *p)
87{
88	struct timeval atv;
89	struct ntptimeval ntv;
90	int s;
91
92	/* All names at this level are terminal. */
93	if (namelen != 1) {
94		return ENOTDIR;
95	}
96
97	if (name[0] != NTP_PLL_GETTIME) {
98		return EOPNOTSUPP;
99	}
100
101	s = splclock();
102#ifdef EXT_CLOCK
103	/*
104	 * The microtime() external clock routine returns a
105	 * status code. If less than zero, we declare an error
106	 * in the clock status word and return the kernel
107	 * (software) time variable. While there are other
108	 * places that call microtime(), this is the only place
109	 * that matters from an application point of view.
110	 */
111	if (microtime(&atv) < 0) {
112		time_status |= STA_CLOCKERR;
113		ntv.time = time;
114	} else {
115		time_status &= ~STA_CLOCKERR;
116	}
117#else /* EXT_CLOCK */
118	microtime(&atv);
119#endif /* EXT_CLOCK */
120	ntv.time = atv;
121	ntv.maxerror = time_maxerror;
122	ntv.esterror = time_esterror;
123	splx(s);
124
125	ntv.time_state = time_state;
126
127	/*
128	 * Status word error decode. If any of these conditions
129	 * occur, an error is returned, instead of the status
130	 * word. Most applications will care only about the fact
131	 * the system clock may not be trusted, not about the
132	 * details.
133	 *
134	 * Hardware or software error
135	 */
136	if (time_status & (STA_UNSYNC | STA_CLOCKERR)) {
137		ntv.time_state = TIME_ERROR;
138	}
139
140	/*
141	 * PPS signal lost when either time or frequency
142	 * synchronization requested
143	 */
144	if (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
145	    !(time_status & STA_PPSSIGNAL)) {
146		ntv.time_state = TIME_ERROR;
147	}
148
149	/*
150	 * PPS jitter exceeded when time synchronization
151	 * requested
152	 */
153	if (time_status & STA_PPSTIME &&
154	    time_status & STA_PPSJITTER) {
155		ntv.time_state = TIME_ERROR;
156	}
157
158	/*
159	 * PPS wander exceeded or calibration error when
160	 * frequency synchronization requested
161	 */
162	if (time_status & STA_PPSFREQ &&
163	    time_status & (STA_PPSWANDER | STA_PPSERROR)) {
164		ntv.time_state = TIME_ERROR;
165	}
166	return(sysctl_rdstruct(oldp, oldlenp, newp, &ntv, sizeof ntv));
167}
168
169/*
170 * ntp_adjtime() - NTP daemon application interface
171 */
172struct ntp_adjtime_args {
173  struct timex *tp;
174};
175
176int
177ntp_adjtime(struct proc *p, struct ntp_adjtime_args *uap, int *retval)
178{
179	struct timex ntv;
180	int modes;
181	int s;
182	int error;
183
184	error = copyin((caddr_t)uap->tp, (caddr_t)&ntv, sizeof(ntv));
185	if (error)
186		return error;
187
188	/*
189	 * Update selected clock variables - only the superuser can
190	 * change anything. Note that there is no error checking here on
191	 * the assumption the superuser should know what it is doing.
192	 */
193	modes = ntv.modes;
194	if ((modes != 0)
195	    && (error = suser(p->p_cred->pc_ucred, &p->p_acflag)))
196		return error;
197
198	s = splclock();
199	if (modes & MOD_FREQUENCY)
200#ifdef PPS_SYNC
201		time_freq = ntv.freq - pps_freq;
202#else /* PPS_SYNC */
203		time_freq = ntv.freq;
204#endif /* PPS_SYNC */
205	if (modes & MOD_MAXERROR)
206		time_maxerror = ntv.maxerror;
207	if (modes & MOD_ESTERROR)
208		time_esterror = ntv.esterror;
209	if (modes & MOD_STATUS) {
210		time_status &= STA_RONLY;
211		time_status |= ntv.status & ~STA_RONLY;
212	}
213	if (modes & MOD_TIMECONST)
214		time_constant = ntv.constant;
215	if (modes & MOD_OFFSET)
216		hardupdate(ntv.offset);
217
218	/*
219	 * Retrieve all clock variables
220	 */
221	if (time_offset < 0)
222		ntv.offset = -(-time_offset >> SHIFT_UPDATE);
223	else
224		ntv.offset = time_offset >> SHIFT_UPDATE;
225#ifdef PPS_SYNC
226	ntv.freq = time_freq + pps_freq;
227#else /* PPS_SYNC */
228	ntv.freq = time_freq;
229#endif /* PPS_SYNC */
230	ntv.maxerror = time_maxerror;
231	ntv.esterror = time_esterror;
232	ntv.status = time_status;
233	ntv.constant = time_constant;
234	ntv.precision = time_precision;
235	ntv.tolerance = time_tolerance;
236#ifdef PPS_SYNC
237	ntv.shift = pps_shift;
238	ntv.ppsfreq = pps_freq;
239	ntv.jitter = pps_jitter >> PPS_AVG;
240	ntv.stabil = pps_stabil;
241	ntv.calcnt = pps_calcnt;
242	ntv.errcnt = pps_errcnt;
243	ntv.jitcnt = pps_jitcnt;
244	ntv.stbcnt = pps_stbcnt;
245#endif /* PPS_SYNC */
246	(void)splx(s);
247
248	error = copyout((caddr_t)&ntv, (caddr_t)uap->tp, sizeof(ntv));
249	if (!error) {
250		/*
251		 * Status word error decode. See comments in
252		 * ntp_gettime() routine.
253		 */
254		retval[0] = time_state;
255		if (time_status & (STA_UNSYNC | STA_CLOCKERR))
256			retval[0] = TIME_ERROR;
257		if (time_status & (STA_PPSFREQ | STA_PPSTIME) &&
258		    !(time_status & STA_PPSSIGNAL))
259			retval[0] = TIME_ERROR;
260		if (time_status & STA_PPSTIME &&
261		    time_status & STA_PPSJITTER)
262			retval[0] = TIME_ERROR;
263		if (time_status & STA_PPSFREQ &&
264		    time_status & (STA_PPSWANDER | STA_PPSERROR))
265			retval[0] = TIME_ERROR;
266	}
267	return error;
268}
269
270
271