2 * Copyright (C) 1993-1998 by Andrey A. Chernov, Moscow, Russia.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 static const char copyright[] =
29 "@(#)Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.\n\
30 All rights reserved.\n";
34 static const char rcsid[] =
39 * Andrey A. Chernov <ache@astral.msk.su> Dec 20 1993
41 * Fix kernel time value if machine run wall CMOS clock
42 * (and /etc/wall_cmos_clock file present)
43 * using zoneinfo rules or direct TZ environment variable set.
44 * Use Joerg Wunsch idea for seconds accurate offset calculation
45 * with Garrett Wollman and Bruce Evans fixes.
54 #include <sys/param.h>
55 #include <machine/cpu.h>
56 #include <sys/sysctl.h>
58 #include "pathnames.h"
66 #define REPORT_PERIOD (30*60)
68 static void fake(int);
69 static void usage(void);
72 fake(int unused __unused)
79 main(int argc, char *argv[])
82 struct timeval tv, *stv;
83 struct timezone tz, *stz;
84 int kern_offset, wall_clock, disrtcset;
87 /* Avoid time_t here, can be unsigned long or worse */
88 long offset, localsec, diff;
89 time_t initial_sec, final_sec;
91 int initial_isdst = -1, final_isdst;
92 int need_restore = False, sleep_mode = False, looping,
96 while ((ch = getopt(argc, argv, "ais")) != -1)
98 case 'i': /* initial call, save offset */
103 case 'a': /* adjustment call, use saved offset */
117 if (access(_PATH_CLOCK, F_OK) != 0)
125 sigaddset(&mask, SIGTERM);
127 openlog("adjkerntz", LOG_PID|LOG_PERROR, LOG_DAEMON);
129 (void) signal(SIGHUP, SIG_IGN);
131 if (init && daemon(0, 1)) {
132 syslog(LOG_ERR, "daemon: %m");
137 (void) sigprocmask(SIG_BLOCK, &mask, NULL);
138 (void) signal(SIGTERM, fake);
145 wall_clock = (access(_PATH_CLOCK, F_OK) == 0);
146 if (init && !sleep_mode) {
152 mib[0] = CTL_MACHDEP;
153 mib[1] = CPU_ADJKERNTZ;
154 len = sizeof(kern_offset);
155 if (sysctl(mib, 2, &kern_offset, &len, NULL, 0) == -1) {
156 syslog(LOG_ERR, "sysctl(get_offset): %m");
160 /****** Critical section, do all things as fast as possible ******/
162 /* get local CMOS clock and possible kernel offset */
163 if (gettimeofday(&tv, &tz)) {
164 syslog(LOG_ERR, "gettimeofday: %m");
168 /* get the actual local timezone difference */
169 initial_sec = tv.tv_sec;
172 local = *localtime(&initial_sec);
174 initial_isdst = local.tm_isdst;
175 local.tm_isdst = initial_isdst;
177 /* calculate local CMOS diff from GMT */
179 localsec = mktime(&local);
180 if (localsec == -1) {
182 * XXX user can only control local time, and it is
183 * unacceptable to fail here for init. 2:30 am in the
184 * middle of the nonexistent hour means 3:30 am.
188 "Warning: nonexistent local time, try to run later.");
189 syslog(LOG_WARNING, "Giving up.");
193 "Warning: nonexistent local time.");
194 syslog(LOG_WARNING, "Will retry after %d minutes.",
196 (void) signal(SIGTERM, SIG_DFL);
197 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
198 (void) sleep(REPORT_PERIOD);
201 offset = -local.tm_gmtoff;
203 fprintf(stderr, "Initial offset: %ld secs\n", offset);
206 /* correct the kerneltime for this diffs */
207 /* subtract kernel offset, if present, old offset too */
209 diff = offset - tz.tz_minuteswest * 60 - kern_offset;
213 fprintf(stderr, "Initial diff: %ld secs\n", diff);
215 /* Yet one step for final time */
217 final_sec = initial_sec + diff;
219 /* get the actual local timezone difference */
220 local = *localtime(&final_sec);
221 final_isdst = diff < 0 ? initial_isdst : local.tm_isdst;
222 if (diff > 0 && initial_isdst != final_isdst) {
226 initial_isdst = final_isdst;
229 local.tm_isdst = final_isdst;
231 localsec = mktime(&local);
232 if (localsec == -1) {
235 * XXX as above. The user has even less control,
236 * but perhaps we never get here.
240 "Warning: nonexistent final local time, try to run later.");
241 syslog(LOG_WARNING, "Giving up.");
245 "Warning: nonexistent final local time.");
246 syslog(LOG_WARNING, "Will retry after %d minutes.",
248 (void) signal(SIGTERM, SIG_DFL);
249 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
250 (void) sleep(REPORT_PERIOD);
253 offset = -local.tm_gmtoff;
255 fprintf(stderr, "Final offset: %ld secs\n", offset);
258 /* correct the kerneltime for this diffs */
259 /* subtract kernel offset, if present, old offset too */
261 diff = offset - tz.tz_minuteswest * 60 - kern_offset;
265 fprintf(stderr, "Final diff: %ld secs\n", diff);
268 * stv is abused as a flag. The important value
275 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) {
276 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */
279 if (!wall_clock && stz == NULL)
282 /* if init or UTC clock and offset/date will be changed, */
283 /* disable RTC modification for a while. */
285 if ( (init && stv != NULL)
286 || ((init || !wall_clock) && kern_offset != offset)
288 mib[0] = CTL_MACHDEP;
289 mib[1] = CPU_DISRTCSET;
290 len = sizeof(disrtcset);
291 if (sysctl(mib, 2, &disrtcset, &len, NULL, 0) == -1) {
292 syslog(LOG_ERR, "sysctl(get_disrtcset): %m");
295 if (disrtcset == 0) {
298 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) {
299 syslog(LOG_ERR, "sysctl(set_disrtcset): %m");
305 if ( (init && (stv != NULL || stz != NULL))
306 || (stz != NULL && stv == NULL)
310 * Get the time again, as close as possible to
311 * adjusting it, to minimise drift.
312 * XXX we'd better not fail between here and
313 * restoring disrtcset, since we don't clean up
316 if (gettimeofday(&tv, (struct timezone *)NULL)) {
317 syslog(LOG_ERR, "gettimeofday: %m");
323 if (settimeofday(stv, stz)) {
324 syslog(LOG_ERR, "settimeofday: %m");
329 /* setting CPU_ADJKERNTZ have a side effect: resettodr(), which */
330 /* can be disabled by CPU_DISRTCSET, so if init or UTC clock */
331 /* -- don't write RTC, else write RTC. */
333 if (kern_offset != offset) {
334 kern_offset = offset;
335 mib[0] = CTL_MACHDEP;
336 mib[1] = CPU_ADJKERNTZ;
337 len = sizeof(kern_offset);
338 if (sysctl(mib, 2, NULL, NULL, &kern_offset, len) == -1) {
339 syslog(LOG_ERR, "sysctl(update_offset): %m");
344 mib[0] = CTL_MACHDEP;
345 mib[1] = CPU_WALLCLOCK;
346 len = sizeof(wall_clock);
347 if (sysctl(mib, 2, NULL, NULL, &wall_clock, len) == -1) {
348 syslog(LOG_ERR, "sysctl(put_wallclock): %m");
353 need_restore = False;
354 mib[0] = CTL_MACHDEP;
355 mib[1] = CPU_DISRTCSET;
357 len = sizeof(disrtcset);
358 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) {
359 syslog(LOG_ERR, "sysctl(restore_disrtcset): %m");
364 /****** End of critical section ******/
366 if (init && wall_clock) {
368 /* wait for signals and acts like -a */
369 (void) sigsuspend(&emask);
379 fprintf(stderr, "%s\n%s\n%s\n%s\n",
380 "usage: adjkerntz -i",
381 "\t\t(initial call from /etc/rc)",
382 " adjkerntz -a [-s]",
383 "\t\t(adjustment call, -s for sleep/retry mode)");