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 #ifndef lint 28 static const char copyright[] = 29 "@(#)Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.\n\ 30 All rights reserved.\n"; 31 #endif /* not lint */ 32 33 #ifndef lint 34 static const char rcsid[] = 35 "$FreeBSD$"; 36 #endif /* not lint */ 37 38 /* 39 * Andrey A. Chernov <ache@astral.msk.su> Dec 20 1993 40 * 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. 46 * 47 */ 48 #include <stdio.h> 49 #include <signal.h> 50 #include <stdlib.h> 51 #include <unistd.h> 52 #include <syslog.h> 53 #include <sys/time.h> 54 #include <sys/param.h> 55 #include <machine/cpu.h> 56 #include <sys/sysctl.h> 57 58 #include "pathnames.h" 59 60 /*#define DEBUG*/ 61 62 #define True (1) 63 #define False (0) 64 #define Unknown (-1) 65 66 #define REPORT_PERIOD (30*60) 67 68 static void usage __P((void)); 69 70 void fake() {} 71 72 int main(argc, argv) 73 int argc; 74 char **argv; 75 { 76 struct tm local; 77 struct timeval tv, *stv; 78 struct timezone tz, *stz; 79 int kern_offset, wall_clock, disrtcset; 80 size_t len; 81 int mib[2]; 82 /* Avoid time_t here, can be unsigned long or worse */ 83 long offset, localsec, diff; 84 time_t initial_sec, final_sec; 85 int ch; 86 int initial_isdst = -1, final_isdst; 87 int need_restore = False, sleep_mode = False, looping, 88 init = Unknown; 89 sigset_t mask, emask; 90 91 while ((ch = getopt(argc, argv, "ais")) != -1) 92 switch((char)ch) { 93 case 'i': /* initial call, save offset */ 94 if (init != Unknown) 95 usage(); 96 init = True; 97 break; 98 case 'a': /* adjustment call, use saved offset */ 99 if (init != Unknown) 100 usage(); 101 init = False; 102 break; 103 case 's': 104 sleep_mode = True; 105 break; 106 default: 107 usage(); 108 } 109 if (init == Unknown) 110 usage(); 111 112 if (access(_PATH_CLOCK, F_OK) != 0) 113 return 0; 114 115 if (init) 116 sleep_mode = True; 117 118 sigemptyset(&mask); 119 sigemptyset(&emask); 120 sigaddset(&mask, SIGTERM); 121 122 openlog("adjkerntz", LOG_PID|LOG_PERROR, LOG_DAEMON); 123 124 (void) signal(SIGHUP, SIG_IGN); 125 126 if (init && daemon(0, 1)) { 127 syslog(LOG_ERR, "daemon: %m"); 128 return 1; 129 } 130 131 again: 132 (void) sigprocmask(SIG_BLOCK, &mask, NULL); 133 (void) signal(SIGTERM, fake); 134 135 diff = 0; 136 stv = NULL; 137 stz = NULL; 138 looping = False; 139 140 wall_clock = (access(_PATH_CLOCK, F_OK) == 0); 141 if (init && !sleep_mode) { 142 init = False; 143 if (!wall_clock) 144 return 0; 145 } 146 147 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"); 152 return 1; 153 } 154 155 /****** Critical section, do all things as fast as possible ******/ 156 157 /* get local CMOS clock and possible kernel offset */ 158 if (gettimeofday(&tv, &tz)) { 159 syslog(LOG_ERR, "gettimeofday: %m"); 160 return 1; 161 } 162 163 /* get the actual local timezone difference */ 164 initial_sec = tv.tv_sec; 165 166 recalculate: 167 local = *localtime(&initial_sec); 168 if (diff == 0) 169 initial_isdst = local.tm_isdst; 170 local.tm_isdst = initial_isdst; 171 172 /* calculate local CMOS diff from GMT */ 173 174 localsec = mktime(&local); 175 if (localsec == -1) { 176 /* 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. 180 */ 181 if (!sleep_mode) { 182 syslog(LOG_WARNING, 183 "Warning: nonexistent local time, try to run later."); 184 syslog(LOG_WARNING, "Giving up."); 185 return 1; 186 } 187 syslog(LOG_WARNING, 188 "Warning: nonexistent local time."); 189 syslog(LOG_WARNING, "Will retry after %d minutes.", 190 REPORT_PERIOD / 60); 191 (void) signal(SIGTERM, SIG_DFL); 192 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 193 (void) sleep(REPORT_PERIOD); 194 goto again; 195 } 196 offset = -local.tm_gmtoff; 197 #ifdef DEBUG 198 fprintf(stderr, "Initial offset: %ld secs\n", offset); 199 #endif 200 201 /* correct the kerneltime for this diffs */ 202 /* subtract kernel offset, if present, old offset too */ 203 204 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 205 206 if (diff != 0) { 207 #ifdef DEBUG 208 fprintf(stderr, "Initial diff: %ld secs\n", diff); 209 #endif 210 /* Yet one step for final time */ 211 212 final_sec = initial_sec + diff; 213 214 /* 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) { 218 if (looping) 219 goto bad_final; 220 looping = True; 221 initial_isdst = final_isdst; 222 goto recalculate; 223 } 224 local.tm_isdst = final_isdst; 225 226 localsec = mktime(&local); 227 if (localsec == -1) { 228 bad_final: 229 /* 230 * XXX as above. The user has even less control, 231 * but perhaps we never get here. 232 */ 233 if (!sleep_mode) { 234 syslog(LOG_WARNING, 235 "Warning: nonexistent final local time, try to run later."); 236 syslog(LOG_WARNING, "Giving up."); 237 return 1; 238 } 239 syslog(LOG_WARNING, 240 "Warning: nonexistent final local time."); 241 syslog(LOG_WARNING, "Will retry after %d minutes.", 242 REPORT_PERIOD / 60); 243 (void) signal(SIGTERM, SIG_DFL); 244 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 245 (void) sleep(REPORT_PERIOD); 246 goto again; 247 } 248 offset = -local.tm_gmtoff; 249 #ifdef DEBUG 250 fprintf(stderr, "Final offset: %ld secs\n", offset); 251 #endif 252 253 /* correct the kerneltime for this diffs */ 254 /* subtract kernel offset, if present, old offset too */ 255 256 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 257 258 if (diff != 0) { 259 #ifdef DEBUG 260 fprintf(stderr, "Final diff: %ld secs\n", diff); 261 #endif 262 /* 263 * stv is abused as a flag. The important value 264 * is in `diff'. 265 */ 266 stv = &tv; 267 } 268 } 269 270 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) { 271 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */ 272 stz = &tz; 273 } 274 if (!wall_clock && stz == NULL) 275 stv = NULL; 276 277 /* if init or UTC clock and offset/date will be changed, */ 278 /* disable RTC modification for a while. */ 279 280 if ( (init && stv != NULL) 281 || ((init || !wall_clock) && kern_offset != offset) 282 ) { 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"); 288 return 1; 289 } 290 if (disrtcset == 0) { 291 disrtcset = 1; 292 need_restore = True; 293 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) { 294 syslog(LOG_ERR, "sysctl(set_disrtcset): %m"); 295 return 1; 296 } 297 } 298 } 299 300 if ( (init && (stv != NULL || stz != NULL)) 301 || (stz != NULL && stv == NULL) 302 ) { 303 if (stv != NULL) { 304 /* 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 309 * anything. 310 */ 311 if (gettimeofday(&tv, (struct timezone *)NULL)) { 312 syslog(LOG_ERR, "gettimeofday: %m"); 313 return 1; 314 } 315 tv.tv_sec += diff; 316 stv = &tv; 317 } 318 if (settimeofday(stv, stz)) { 319 syslog(LOG_ERR, "settimeofday: %m"); 320 return 1; 321 } 322 } 323 324 /* 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. */ 327 328 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"); 335 return 1; 336 } 337 } 338 339 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"); 344 return 1; 345 } 346 347 if (need_restore) { 348 need_restore = False; 349 mib[0] = CTL_MACHDEP; 350 mib[1] = CPU_DISRTCSET; 351 disrtcset = 0; 352 len = sizeof(disrtcset); 353 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) { 354 syslog(LOG_ERR, "sysctl(restore_disrtcset): %m"); 355 return 1; 356 } 357 } 358 359 /****** End of critical section ******/ 360 361 if (init && wall_clock) { 362 sleep_mode = False; 363 /* wait for signals and acts like -a */ 364 (void) sigsuspend(&emask); 365 goto again; 366 } 367 368 return 0; 369 } 370 371 static void 372 usage() 373 { 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)"); 379 exit(2); 380 } 381