1 /* 2 * Copyright (C) 1993-1998 by Andrey 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 #if 0 28 #ifndef lint 29 static const char copyright[] = 30 "@(#)Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.\n\ 31 All rights reserved.\n"; 32 #endif /* not lint */ 33 #endif 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 /* 38 * Andrey A. Chernov <ache@astral.msk.su> Dec 20 1993 39 * 40 * Fix kernel time value if machine run wall CMOS clock 41 * (and /etc/wall_cmos_clock file present) 42 * using zoneinfo rules or direct TZ environment variable set. 43 * Use Joerg Wunsch idea for seconds accurate offset calculation 44 * with Garrett Wollman and Bruce Evans fixes. 45 * 46 */ 47 #include <stdio.h> 48 #include <signal.h> 49 #include <stdlib.h> 50 #include <unistd.h> 51 #include <syslog.h> 52 #include <sys/time.h> 53 #include <sys/param.h> 54 #include <machine/cpu.h> 55 #include <sys/sysctl.h> 56 57 #include "pathnames.h" 58 59 /*#define DEBUG*/ 60 61 #define True (1) 62 #define False (0) 63 #define Unknown (-1) 64 65 #define REPORT_PERIOD (30*60) 66 67 static void fake(int); 68 static void usage(void); 69 70 static void 71 fake(int unused __unused) 72 { 73 74 /* Do nothing. */ 75 } 76 77 int 78 main(int argc, char *argv[]) 79 { 80 struct tm local; 81 struct timeval tv, *stv; 82 struct timezone tz, *stz; 83 int kern_offset, wall_clock, disrtcset; 84 size_t len; 85 /* Avoid time_t here, can be unsigned long or worse */ 86 long offset, localsec, diff; 87 time_t initial_sec, final_sec; 88 int ch; 89 int initial_isdst = -1, final_isdst; 90 int need_restore = False, sleep_mode = False, looping, 91 init = Unknown; 92 sigset_t mask, emask; 93 94 while ((ch = getopt(argc, argv, "ais")) != -1) 95 switch((char)ch) { 96 case 'i': /* initial call, save offset */ 97 if (init != Unknown) 98 usage(); 99 init = True; 100 break; 101 case 'a': /* adjustment call, use saved offset */ 102 if (init != Unknown) 103 usage(); 104 init = False; 105 break; 106 case 's': 107 sleep_mode = True; 108 break; 109 default: 110 usage(); 111 } 112 if (init == Unknown) 113 usage(); 114 115 if (access(_PATH_CLOCK, F_OK) != 0) 116 return 0; 117 118 if (init) 119 sleep_mode = True; 120 121 sigemptyset(&mask); 122 sigemptyset(&emask); 123 sigaddset(&mask, SIGTERM); 124 125 openlog("adjkerntz", LOG_PID|LOG_PERROR, LOG_DAEMON); 126 127 (void) signal(SIGHUP, SIG_IGN); 128 129 if (init && daemon(0, 1)) { 130 syslog(LOG_ERR, "daemon: %m"); 131 return 1; 132 } 133 134 again: 135 (void) sigprocmask(SIG_BLOCK, &mask, NULL); 136 (void) signal(SIGTERM, fake); 137 138 diff = 0; 139 stv = NULL; 140 stz = NULL; 141 looping = False; 142 143 wall_clock = (access(_PATH_CLOCK, F_OK) == 0); 144 if (init && !sleep_mode) { 145 init = False; 146 if (!wall_clock) 147 return 0; 148 } 149 150 tzset(); 151 152 len = sizeof(kern_offset); 153 if (sysctlbyname("machdep.adjkerntz", &kern_offset, &len, NULL, 0) == -1) { 154 syslog(LOG_ERR, "sysctl(\"machdep.adjkerntz\"): %m"); 155 return 1; 156 } 157 158 /****** Critical section, do all things as fast as possible ******/ 159 160 /* get local CMOS clock and possible kernel offset */ 161 if (gettimeofday(&tv, &tz)) { 162 syslog(LOG_ERR, "gettimeofday: %m"); 163 return 1; 164 } 165 166 /* get the actual local timezone difference */ 167 initial_sec = tv.tv_sec; 168 169 recalculate: 170 local = *localtime(&initial_sec); 171 if (diff == 0) 172 initial_isdst = local.tm_isdst; 173 local.tm_isdst = initial_isdst; 174 175 /* calculate local CMOS diff from GMT */ 176 177 localsec = mktime(&local); 178 if (localsec == -1) { 179 /* 180 * XXX user can only control local time, and it is 181 * unacceptable to fail here for init. 2:30 am in the 182 * middle of the nonexistent hour means 3:30 am. 183 */ 184 if (!sleep_mode) { 185 syslog(LOG_WARNING, 186 "Warning: nonexistent local time, try to run later."); 187 syslog(LOG_WARNING, "Giving up."); 188 return 1; 189 } 190 syslog(LOG_WARNING, 191 "Warning: nonexistent local time."); 192 syslog(LOG_WARNING, "Will retry after %d minutes.", 193 REPORT_PERIOD / 60); 194 (void) signal(SIGTERM, SIG_DFL); 195 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 196 (void) sleep(REPORT_PERIOD); 197 goto again; 198 } 199 offset = -local.tm_gmtoff; 200 #ifdef DEBUG 201 fprintf(stderr, "Initial offset: %ld secs\n", offset); 202 #endif 203 204 /* correct the kerneltime for this diffs */ 205 /* subtract kernel offset, if present, old offset too */ 206 207 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 208 209 if (diff != 0) { 210 #ifdef DEBUG 211 fprintf(stderr, "Initial diff: %ld secs\n", diff); 212 #endif 213 /* Yet one step for final time */ 214 215 final_sec = initial_sec + diff; 216 217 /* get the actual local timezone difference */ 218 local = *localtime(&final_sec); 219 final_isdst = diff < 0 ? initial_isdst : local.tm_isdst; 220 if (diff > 0 && initial_isdst != final_isdst) { 221 if (looping) 222 goto bad_final; 223 looping = True; 224 initial_isdst = final_isdst; 225 goto recalculate; 226 } 227 local.tm_isdst = final_isdst; 228 229 localsec = mktime(&local); 230 if (localsec == -1) { 231 bad_final: 232 /* 233 * XXX as above. The user has even less control, 234 * but perhaps we never get here. 235 */ 236 if (!sleep_mode) { 237 syslog(LOG_WARNING, 238 "Warning: nonexistent final local time, try to run later."); 239 syslog(LOG_WARNING, "Giving up."); 240 return 1; 241 } 242 syslog(LOG_WARNING, 243 "Warning: nonexistent final local time."); 244 syslog(LOG_WARNING, "Will retry after %d minutes.", 245 REPORT_PERIOD / 60); 246 (void) signal(SIGTERM, SIG_DFL); 247 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 248 (void) sleep(REPORT_PERIOD); 249 goto again; 250 } 251 offset = -local.tm_gmtoff; 252 #ifdef DEBUG 253 fprintf(stderr, "Final offset: %ld secs\n", offset); 254 #endif 255 256 /* correct the kerneltime for this diffs */ 257 /* subtract kernel offset, if present, old offset too */ 258 259 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 260 261 if (diff != 0) { 262 #ifdef DEBUG 263 fprintf(stderr, "Final diff: %ld secs\n", diff); 264 #endif 265 /* 266 * stv is abused as a flag. The important value 267 * is in `diff'. 268 */ 269 stv = &tv; 270 } 271 } 272 273 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) { 274 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */ 275 stz = &tz; 276 } 277 if (!wall_clock && stz == NULL) 278 stv = NULL; 279 280 /* if init or UTC clock and offset/date will be changed, */ 281 /* disable RTC modification for a while. */ 282 283 if ( (init && stv != NULL) 284 || ((init || !wall_clock) && kern_offset != offset) 285 ) { 286 len = sizeof(disrtcset); 287 if (sysctlbyname("machdep.disable_rtc_set", &disrtcset, &len, NULL, 0) == -1) { 288 syslog(LOG_ERR, "sysctl(get: \"machdep.disable_rtc_set\"): %m"); 289 return 1; 290 } 291 if (disrtcset == 0) { 292 disrtcset = 1; 293 need_restore = True; 294 if (sysctlbyname("machdep.disable_rtc_set", NULL, NULL, &disrtcset, len) == -1) { 295 syslog(LOG_ERR, "sysctl(set: \"machdep.disable_rtc_set\"): %m"); 296 return 1; 297 } 298 } 299 } 300 301 if ( (init && (stv != NULL || stz != NULL)) 302 || (stz != NULL && stv == NULL) 303 ) { 304 if (stv != NULL) { 305 /* 306 * Get the time again, as close as possible to 307 * adjusting it, to minimise drift. 308 * XXX we'd better not fail between here and 309 * restoring disrtcset, since we don't clean up 310 * anything. 311 */ 312 if (gettimeofday(&tv, (struct timezone *)NULL)) { 313 syslog(LOG_ERR, "gettimeofday: %m"); 314 return 1; 315 } 316 tv.tv_sec += diff; 317 stv = &tv; 318 } 319 if (settimeofday(stv, stz)) { 320 syslog(LOG_ERR, "settimeofday: %m"); 321 return 1; 322 } 323 } 324 325 /* setting machdep.adjkerntz have a side effect: resettodr(), which */ 326 /* can be disabled by machdep.disable_rtc_set, so if init or UTC clock */ 327 /* -- don't write RTC, else write RTC. */ 328 329 if (kern_offset != offset) { 330 kern_offset = offset; 331 len = sizeof(kern_offset); 332 if (sysctlbyname("machdep.adjkerntz", NULL, NULL, &kern_offset, len) == -1) { 333 syslog(LOG_ERR, "sysctl(set: \"machdep.adjkerntz\"): %m"); 334 return 1; 335 } 336 } 337 338 len = sizeof(wall_clock); 339 if (sysctlbyname("machdep.wall_cmos_clock", NULL, NULL, &wall_clock, len) == -1) { 340 syslog(LOG_ERR, "sysctl(set: \"machdep.wall_cmos_clock\"): %m"); 341 return 1; 342 } 343 344 if (need_restore) { 345 need_restore = False; 346 disrtcset = 0; 347 len = sizeof(disrtcset); 348 if (sysctlbyname("machdep.disable_rtc_set", NULL, NULL, &disrtcset, len) == -1) { 349 syslog(LOG_ERR, "sysctl(set: \"machdep.disable_rtc_set\"): %m"); 350 return 1; 351 } 352 } 353 354 /****** End of critical section ******/ 355 356 if (init && wall_clock) { 357 sleep_mode = False; 358 /* wait for signals and acts like -a */ 359 (void) sigsuspend(&emask); 360 goto again; 361 } 362 363 return 0; 364 } 365 366 static void 367 usage(void) 368 { 369 fprintf(stderr, "%s\n%s\n%s\n%s\n", 370 "usage: adjkerntz -i", 371 "\t\t(initial call from /etc/rc)", 372 " adjkerntz -a [-s]", 373 "\t\t(adjustment call, -s for sleep/retry mode)"); 374 exit(2); 375 } 376