1/*
2 * Copyright (C) 1993 by Andrew A. Chernov, Moscow, Russia.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27#ifndef lint
28char copyright[] =
29"@(#)Copyright (C) 1993 by Andrew A. Chernov, Moscow, Russia.\n\
30 All rights reserved.\n";
31#endif /* not lint */
32
33/*
34 * Andrew A. Chernov <ache@astral.msk.su> Dec 20 1993
35 *
36 * Fix kernel time value if machine run wall CMOS clock
37 * (and /etc/wall_cmos_clock file present)
38 * using zoneinfo rules or direct TZ environment variable set.
39 * Use Joerg Wunsch idea for seconds accurate offset calculation
40 * with Garrett Wollman and Bruce Evans fixes.
41 *
42 */
43#include <stdio.h>
44#include <stdlib.h>
45#include <unistd.h>
46#include <sys/stat.h>
47#include <sys/time.h>
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48#include <sys/param.h>
49#include <machine/cpu.h>
50#include <sys/sysctl.h> |
51
52#include "pathnames.h"
53
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51char storage[] = _PATH_OFFSET;
52
|
54int main(argc, argv)
55 int argc;
56 char **argv;
57{
58 struct tm local, utc;
59 struct timeval tv, *stv;
60 struct timezone tz, *stz;
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61 int kern_offset;
62 size_t len;
63 int mib[2]; |
64 /* Avoid time_t here, can be unsigned long or worse */
|
61 long offset, oldoffset, utcsec, localsec, diff;
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| 65 long offset, utcsec, localsec, diff; |
66 time_t initial_sec, final_sec;
67 int ch, init = -1, verbose = 0;
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64 FILE *f;
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68
69 while ((ch = getopt(argc, argv, "aiv")) != EOF)
70 switch((char)ch) {
71 case 'i': /* initial call, save offset */
72 if (init != -1)
73 goto usage;
74 init = 1;
75 break;
76 case 'a': /* adjustment call, use saved offset */
77 if (init != -1)
78 goto usage;
79 init = 0;
80 break;
81 case 'v': /* verbose */
82 verbose = 1;
83 break;
84 default:
85 usage:
86 fprintf(stderr, "Usage:\n\
87\tadjkerntz -i [-v]\t(initial call from /etc/rc)\n\
88\tadjkerntz -a [-v]\t(adjustment call from crontab)\n");
89 return 2;
90 }
91 if (init == -1)
92 goto usage;
93
94 if (access(_PATH_CLOCK, F_OK))
95 return 0;
96
97 /* Restore saved offset */
98
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96 if (!init) {
97 if ((f = fopen(storage, "r")) == NULL) {
98 perror(storage);
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99 mib[0] = CTL_MACHDEP;
100 mib[1] = CPU_ADJKERNTZ;
101 len = sizeof(kern_offset);
102 if (sysctl(mib, 2, &kern_offset, &len, NULL, 0) == -1) {
103 perror("sysctl(get_offset)"); |
104 return 1;
105 }
|
101 if (fscanf(f, "%ld", &oldoffset) != 1) {
102 fprintf(stderr, "Misformatted offset in %s\n",
103 storage);
104 return 1;
105 }
106 (void) fclose(f);
107 }
108 else
109 oldoffset = 0;
|
106
107/****** Critical section, do all things as fast as possible ******/
108
109 /* get local CMOS clock and possible kernel offset */
110 if (gettimeofday(&tv, &tz)) {
111 perror("gettimeofday");
112 return 1;
113 }
114
115 /* get the actual local timezone difference */
116 initial_sec = tv.tv_sec;
117 local = *localtime(&initial_sec);
118 utc = *gmtime(&initial_sec);
119 utc.tm_isdst = local.tm_isdst; /* Use current timezone for mktime(), */
120 /* because it assumed local time */
121
122 /* calculate local CMOS diff from GMT */
123
124 utcsec = mktime(&utc);
125 localsec = mktime(&local);
126 if (utcsec == -1 || localsec == -1) {
127 /*
128 * XXX user can only control local time, and it is
129 * unacceptable to fail here for -i. 2:30 am in the
130 * middle of the nonexistent hour means 3:30 am.
131 */
132 fprintf(stderr,
133 "Nonexistent local time - try again in an hour\n");
134 return 1;
135 }
136 offset = utcsec - localsec;
137
138 /* correct the kerneltime for this diffs */
139 /* subtract kernel offset, if present, old offset too */
140
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145 diff = offset - tz.tz_minuteswest * 60 - oldoffset;
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| 141 diff = offset - tz.tz_minuteswest * 60 - kern_offset; |
142
143 if (diff != 0) {
144
145 /* Yet one step for final time */
146
147 final_sec = tv.tv_sec + diff;
148
149 /* get the actual local timezone difference */
150 local = *localtime(&final_sec);
151 utc = *gmtime(&final_sec);
152 utc.tm_isdst = local.tm_isdst; /* Use current timezone for mktime(), */
153 /* because it assumed local time */
154
155 utcsec = mktime(&utc);
156 localsec = mktime(&local);
157 if (utcsec == -1 || localsec == -1) {
158 /*
159 * XXX as above. The user has even less control,
160 * but perhaps we never get here.
161 */
162 fprintf(stderr,
163 "Nonexistent (final) local time - try again in an hour\n");
164 return 1;
165 }
166 offset = utcsec - localsec;
167
168 /* correct the kerneltime for this diffs */
169 /* subtract kernel offset, if present, old offset too */
170
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175 diff = offset - tz.tz_minuteswest * 60 - oldoffset;
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| 171 diff = offset - tz.tz_minuteswest * 60 - kern_offset; |
172
173 if (diff != 0) {
174 tv.tv_sec += diff;
175 tv.tv_usec = 0; /* we are restarting here... */
176 stv = &tv;
177 }
178 else
179 stv = NULL;
180 }
181 else
182 stv = NULL;
183
|
184 if (kern_offset != offset) {
185 kern_offset = offset;
186 mib[0] = CTL_MACHDEP;
187 mib[1] = CPU_ADJKERNTZ;
188 len = sizeof(kern_offset);
189 if (sysctl(mib, 2, NULL, NULL, &kern_offset, len) == -1) {
190 perror("sysctl(update_offset)");
191 return 1;
192 }
193 }
194 |
195 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) {
196 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */
197 stz = &tz;
198 }
199 else
200 stz = NULL;
201
202 if (stz != NULL || stv != NULL) {
203 if (settimeofday(stv, stz)) {
204 perror("settimeofday");
205 return 1;
206 }
207 }
208
209/****** End of critical section ******/
210
211 if (verbose)
212 printf("Calculated zone offset difference: %ld seconds\n",
213 diff);
214
|
208 if (offset != oldoffset) {
209 (void) umask(022);
210 /* Save offset for next calls from crontab */
211 if ((f = fopen(storage, "w")) == NULL) {
212 perror(storage);
213 return 1;
214 }
215 fprintf(f, "%ld\n", offset);
216 if (fclose(f)) {
217 perror(storage);
218 return 1;
219 }
220 }
221
|
215 return 0;
216}
217
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