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
26 * @(#)Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia. All rights reserved.
27 * $FreeBSD: src/sbin/adjkerntz/adjkerntz.c,v 1.25.2.1 2001/07/30 10:38:04 dd Exp $
28 * $DragonFly: src/sbin/adjkerntz/adjkerntz.c,v 1.2 2003/06/17 04:27:32 dillon Exp $
32 * Andrey A. Chernov <ache@astral.msk.su> Dec 20 1993
34 * Fix kernel time value if machine run wall CMOS clock
35 * (and /etc/wall_cmos_clock file present)
36 * using zoneinfo rules or direct TZ environment variable set.
37 * Use Joerg Wunsch idea for seconds accurate offset calculation
38 * with Garrett Wollman and Bruce Evans fixes.
47 #include <sys/param.h>
48 #include <machine/cpu.h>
49 #include <sys/sysctl.h>
51 #include "pathnames.h"
59 #define REPORT_PERIOD (30*60)
61 static void fake __P((int));
62 static void usage __P((void));
77 struct timeval tv, *stv;
78 struct timezone tz, *stz;
79 int kern_offset, wall_clock, disrtcset;
82 /* Avoid time_t here, can be unsigned long or worse */
83 long offset, localsec, diff;
84 time_t initial_sec, final_sec;
86 int initial_isdst = -1, final_isdst;
87 int need_restore = False, sleep_mode = False, looping,
91 while ((ch = getopt(argc, argv, "ais")) != -1)
93 case 'i': /* initial call, save offset */
98 case 'a': /* adjustment call, use saved offset */
112 if (access(_PATH_CLOCK, F_OK) != 0)
120 sigaddset(&mask, SIGTERM);
122 openlog("adjkerntz", LOG_PID|LOG_PERROR, LOG_DAEMON);
124 (void) signal(SIGHUP, SIG_IGN);
126 if (init && daemon(0, 1)) {
127 syslog(LOG_ERR, "daemon: %m");
132 (void) sigprocmask(SIG_BLOCK, &mask, NULL);
133 (void) signal(SIGTERM, fake);
140 wall_clock = (access(_PATH_CLOCK, F_OK) == 0);
141 if (init && !sleep_mode) {
147 mib[0] = CTL_MACHDEP;
148 mib[1] = CPU_ADJKERNTZ;
149 len = sizeof(kern_offset);
150 if (sysctl(mib, 2, &kern_offset, &len, NULL, 0) == -1) {
151 syslog(LOG_ERR, "sysctl(get_offset): %m");
155 /****** Critical section, do all things as fast as possible ******/
157 /* get local CMOS clock and possible kernel offset */
158 if (gettimeofday(&tv, &tz)) {
159 syslog(LOG_ERR, "gettimeofday: %m");
163 /* get the actual local timezone difference */
164 initial_sec = tv.tv_sec;
167 local = *localtime(&initial_sec);
169 initial_isdst = local.tm_isdst;
170 local.tm_isdst = initial_isdst;
172 /* calculate local CMOS diff from GMT */
174 localsec = mktime(&local);
175 if (localsec == -1) {
177 * XXX user can only control local time, and it is
178 * unacceptable to fail here for init. 2:30 am in the
179 * middle of the nonexistent hour means 3:30 am.
183 "Warning: nonexistent local time, try to run later.");
184 syslog(LOG_WARNING, "Giving up.");
188 "Warning: nonexistent local time.");
189 syslog(LOG_WARNING, "Will retry after %d minutes.",
191 (void) signal(SIGTERM, SIG_DFL);
192 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
193 (void) sleep(REPORT_PERIOD);
196 offset = -local.tm_gmtoff;
198 fprintf(stderr, "Initial offset: %ld secs\n", offset);
201 /* correct the kerneltime for this diffs */
202 /* subtract kernel offset, if present, old offset too */
204 diff = offset - tz.tz_minuteswest * 60 - kern_offset;
208 fprintf(stderr, "Initial diff: %ld secs\n", diff);
210 /* Yet one step for final time */
212 final_sec = initial_sec + diff;
214 /* get the actual local timezone difference */
215 local = *localtime(&final_sec);
216 final_isdst = diff < 0 ? initial_isdst : local.tm_isdst;
217 if (diff > 0 && initial_isdst != final_isdst) {
221 initial_isdst = final_isdst;
224 local.tm_isdst = final_isdst;
226 localsec = mktime(&local);
227 if (localsec == -1) {
230 * XXX as above. The user has even less control,
231 * but perhaps we never get here.
235 "Warning: nonexistent final local time, try to run later.");
236 syslog(LOG_WARNING, "Giving up.");
240 "Warning: nonexistent final local time.");
241 syslog(LOG_WARNING, "Will retry after %d minutes.",
243 (void) signal(SIGTERM, SIG_DFL);
244 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL);
245 (void) sleep(REPORT_PERIOD);
248 offset = -local.tm_gmtoff;
250 fprintf(stderr, "Final offset: %ld secs\n", offset);
253 /* correct the kerneltime for this diffs */
254 /* subtract kernel offset, if present, old offset too */
256 diff = offset - tz.tz_minuteswest * 60 - kern_offset;
260 fprintf(stderr, "Final diff: %ld secs\n", diff);
263 * stv is abused as a flag. The important value
270 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) {
271 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */
274 if (!wall_clock && stz == NULL)
277 /* if init or UTC clock and offset/date will be changed, */
278 /* disable RTC modification for a while. */
280 if ( (init && stv != NULL)
281 || ((init || !wall_clock) && kern_offset != offset)
283 mib[0] = CTL_MACHDEP;
284 mib[1] = CPU_DISRTCSET;
285 len = sizeof(disrtcset);
286 if (sysctl(mib, 2, &disrtcset, &len, NULL, 0) == -1) {
287 syslog(LOG_ERR, "sysctl(get_disrtcset): %m");
290 if (disrtcset == 0) {
293 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) {
294 syslog(LOG_ERR, "sysctl(set_disrtcset): %m");
300 if ( (init && (stv != NULL || stz != NULL))
301 || (stz != NULL && stv == NULL)
305 * Get the time again, as close as possible to
306 * adjusting it, to minimise drift.
307 * XXX we'd better not fail between here and
308 * restoring disrtcset, since we don't clean up
311 if (gettimeofday(&tv, (struct timezone *)NULL)) {
312 syslog(LOG_ERR, "gettimeofday: %m");
318 if (settimeofday(stv, stz)) {
319 syslog(LOG_ERR, "settimeofday: %m");
324 /* setting CPU_ADJKERNTZ have a side effect: resettodr(), which */
325 /* can be disabled by CPU_DISRTCSET, so if init or UTC clock */
326 /* -- don't write RTC, else write RTC. */
328 if (kern_offset != offset) {
329 kern_offset = offset;
330 mib[0] = CTL_MACHDEP;
331 mib[1] = CPU_ADJKERNTZ;
332 len = sizeof(kern_offset);
333 if (sysctl(mib, 2, NULL, NULL, &kern_offset, len) == -1) {
334 syslog(LOG_ERR, "sysctl(update_offset): %m");
339 mib[0] = CTL_MACHDEP;
340 mib[1] = CPU_WALLCLOCK;
341 len = sizeof(wall_clock);
342 if (sysctl(mib, 2, NULL, NULL, &wall_clock, len) == -1) {
343 syslog(LOG_ERR, "sysctl(put_wallclock): %m");
348 need_restore = False;
349 mib[0] = CTL_MACHDEP;
350 mib[1] = CPU_DISRTCSET;
352 len = sizeof(disrtcset);
353 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) {
354 syslog(LOG_ERR, "sysctl(restore_disrtcset): %m");
359 /****** End of critical section ******/
361 if (init && wall_clock) {
363 /* wait for signals and acts like -a */
364 (void) sigsuspend(&emask);
374 fprintf(stderr, "%s\n%s\n%s\n%s\n",
375 "usage: adjkerntz -i",
376 "\t\t(initial call from /etc/rc)",
377 " adjkerntz -a [-s]",
378 "\t\t(adjustment call, -s for sleep/retry mode)");