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 fake __P((int)); 69 static void usage __P((void)); 70 71 static void 72 fake(unused) 73 int unused __unused; 74 { 75 76 /* Do nothing. */ 77 } 78 79 int main(argc, argv) 80 int argc; 81 char **argv; 82 { 83 struct tm local; 84 struct timeval tv, *stv; 85 struct timezone tz, *stz; 86 int kern_offset, wall_clock, disrtcset; 87 size_t len; 88 int mib[2]; 89 /* Avoid time_t here, can be unsigned long or worse */ 90 long offset, localsec, diff; 91 time_t initial_sec, final_sec; 92 int ch; 93 int initial_isdst = -1, final_isdst; 94 int need_restore = False, sleep_mode = False, looping, 95 init = Unknown; 96 sigset_t mask, emask; 97 98 while ((ch = getopt(argc, argv, "ais")) != -1) 99 switch((char)ch) { 100 case 'i': /* initial call, save offset */ 101 if (init != Unknown) 102 usage(); 103 init = True; 104 break; 105 case 'a': /* adjustment call, use saved offset */ 106 if (init != Unknown) 107 usage(); 108 init = False; 109 break; 110 case 's': 111 sleep_mode = True; 112 break; 113 default: 114 usage(); 115 } 116 if (init == Unknown) 117 usage(); 118 119 if (access(_PATH_CLOCK, F_OK) != 0) 120 return 0; 121 122 if (init) 123 sleep_mode = True; 124 125 sigemptyset(&mask); 126 sigemptyset(&emask); 127 sigaddset(&mask, SIGTERM); 128 129 openlog("adjkerntz", LOG_PID|LOG_PERROR, LOG_DAEMON); 130 131 (void) signal(SIGHUP, SIG_IGN); 132 133 if (init && daemon(0, 1)) { 134 syslog(LOG_ERR, "daemon: %m"); 135 return 1; 136 } 137 138 again: 139 (void) sigprocmask(SIG_BLOCK, &mask, NULL); 140 (void) signal(SIGTERM, fake); 141 142 diff = 0; 143 stv = NULL; 144 stz = NULL; 145 looping = False; 146 147 wall_clock = (access(_PATH_CLOCK, F_OK) == 0); 148 if (init && !sleep_mode) { 149 init = False; 150 if (!wall_clock) 151 return 0; 152 } 153 154 mib[0] = CTL_MACHDEP; 155 mib[1] = CPU_ADJKERNTZ; 156 len = sizeof(kern_offset); 157 if (sysctl(mib, 2, &kern_offset, &len, NULL, 0) == -1) { 158 syslog(LOG_ERR, "sysctl(get_offset): %m"); 159 return 1; 160 } 161 162 /****** Critical section, do all things as fast as possible ******/ 163 164 /* get local CMOS clock and possible kernel offset */ 165 if (gettimeofday(&tv, &tz)) { 166 syslog(LOG_ERR, "gettimeofday: %m"); 167 return 1; 168 } 169 170 /* get the actual local timezone difference */ 171 initial_sec = tv.tv_sec; 172 173 recalculate: 174 local = *localtime(&initial_sec); 175 if (diff == 0) 176 initial_isdst = local.tm_isdst; 177 local.tm_isdst = initial_isdst; 178 179 /* calculate local CMOS diff from GMT */ 180 181 localsec = mktime(&local); 182 if (localsec == -1) { 183 /* 184 * XXX user can only control local time, and it is 185 * unacceptable to fail here for init. 2:30 am in the 186 * middle of the nonexistent hour means 3:30 am. 187 */ 188 if (!sleep_mode) { 189 syslog(LOG_WARNING, 190 "Warning: nonexistent local time, try to run later."); 191 syslog(LOG_WARNING, "Giving up."); 192 return 1; 193 } 194 syslog(LOG_WARNING, 195 "Warning: nonexistent local time."); 196 syslog(LOG_WARNING, "Will retry after %d minutes.", 197 REPORT_PERIOD / 60); 198 (void) signal(SIGTERM, SIG_DFL); 199 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 200 (void) sleep(REPORT_PERIOD); 201 goto again; 202 } 203 offset = -local.tm_gmtoff; 204 #ifdef DEBUG 205 fprintf(stderr, "Initial offset: %ld secs\n", offset); 206 #endif 207 208 /* correct the kerneltime for this diffs */ 209 /* subtract kernel offset, if present, old offset too */ 210 211 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 212 213 if (diff != 0) { 214 #ifdef DEBUG 215 fprintf(stderr, "Initial diff: %ld secs\n", diff); 216 #endif 217 /* Yet one step for final time */ 218 219 final_sec = initial_sec + diff; 220 221 /* get the actual local timezone difference */ 222 local = *localtime(&final_sec); 223 final_isdst = diff < 0 ? initial_isdst : local.tm_isdst; 224 if (diff > 0 && initial_isdst != final_isdst) { 225 if (looping) 226 goto bad_final; 227 looping = True; 228 initial_isdst = final_isdst; 229 goto recalculate; 230 } 231 local.tm_isdst = final_isdst; 232 233 localsec = mktime(&local); 234 if (localsec == -1) { 235 bad_final: 236 /* 237 * XXX as above. The user has even less control, 238 * but perhaps we never get here. 239 */ 240 if (!sleep_mode) { 241 syslog(LOG_WARNING, 242 "Warning: nonexistent final local time, try to run later."); 243 syslog(LOG_WARNING, "Giving up."); 244 return 1; 245 } 246 syslog(LOG_WARNING, 247 "Warning: nonexistent final local time."); 248 syslog(LOG_WARNING, "Will retry after %d minutes.", 249 REPORT_PERIOD / 60); 250 (void) signal(SIGTERM, SIG_DFL); 251 (void) sigprocmask(SIG_UNBLOCK, &mask, NULL); 252 (void) sleep(REPORT_PERIOD); 253 goto again; 254 } 255 offset = -local.tm_gmtoff; 256 #ifdef DEBUG 257 fprintf(stderr, "Final offset: %ld secs\n", offset); 258 #endif 259 260 /* correct the kerneltime for this diffs */ 261 /* subtract kernel offset, if present, old offset too */ 262 263 diff = offset - tz.tz_minuteswest * 60 - kern_offset; 264 265 if (diff != 0) { 266 #ifdef DEBUG 267 fprintf(stderr, "Final diff: %ld secs\n", diff); 268 #endif 269 /* 270 * stv is abused as a flag. The important value 271 * is in `diff'. 272 */ 273 stv = &tv; 274 } 275 } 276 277 if (tz.tz_dsttime != 0 || tz.tz_minuteswest != 0) { 278 tz.tz_dsttime = tz.tz_minuteswest = 0; /* zone info is garbage */ 279 stz = &tz; 280 } 281 if (!wall_clock && stz == NULL) 282 stv = NULL; 283 284 /* if init or UTC clock and offset/date will be changed, */ 285 /* disable RTC modification for a while. */ 286 287 if ( (init && stv != NULL) 288 || ((init || !wall_clock) && kern_offset != offset) 289 ) { 290 mib[0] = CTL_MACHDEP; 291 mib[1] = CPU_DISRTCSET; 292 len = sizeof(disrtcset); 293 if (sysctl(mib, 2, &disrtcset, &len, NULL, 0) == -1) { 294 syslog(LOG_ERR, "sysctl(get_disrtcset): %m"); 295 return 1; 296 } 297 if (disrtcset == 0) { 298 disrtcset = 1; 299 need_restore = True; 300 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) { 301 syslog(LOG_ERR, "sysctl(set_disrtcset): %m"); 302 return 1; 303 } 304 } 305 } 306 307 if ( (init && (stv != NULL || stz != NULL)) 308 || (stz != NULL && stv == NULL) 309 ) { 310 if (stv != NULL) { 311 /* 312 * Get the time again, as close as possible to 313 * adjusting it, to minimise drift. 314 * XXX we'd better not fail between here and 315 * restoring disrtcset, since we don't clean up 316 * anything. 317 */ 318 if (gettimeofday(&tv, (struct timezone *)NULL)) { 319 syslog(LOG_ERR, "gettimeofday: %m"); 320 return 1; 321 } 322 tv.tv_sec += diff; 323 stv = &tv; 324 } 325 if (settimeofday(stv, stz)) { 326 syslog(LOG_ERR, "settimeofday: %m"); 327 return 1; 328 } 329 } 330 331 /* setting CPU_ADJKERNTZ have a side effect: resettodr(), which */ 332 /* can be disabled by CPU_DISRTCSET, so if init or UTC clock */ 333 /* -- don't write RTC, else write RTC. */ 334 335 if (kern_offset != offset) { 336 kern_offset = offset; 337 mib[0] = CTL_MACHDEP; 338 mib[1] = CPU_ADJKERNTZ; 339 len = sizeof(kern_offset); 340 if (sysctl(mib, 2, NULL, NULL, &kern_offset, len) == -1) { 341 syslog(LOG_ERR, "sysctl(update_offset): %m"); 342 return 1; 343 } 344 } 345 346 mib[0] = CTL_MACHDEP; 347 mib[1] = CPU_WALLCLOCK; 348 len = sizeof(wall_clock); 349 if (sysctl(mib, 2, NULL, NULL, &wall_clock, len) == -1) { 350 syslog(LOG_ERR, "sysctl(put_wallclock): %m"); 351 return 1; 352 } 353 354 if (need_restore) { 355 need_restore = False; 356 mib[0] = CTL_MACHDEP; 357 mib[1] = CPU_DISRTCSET; 358 disrtcset = 0; 359 len = sizeof(disrtcset); 360 if (sysctl(mib, 2, NULL, NULL, &disrtcset, len) == -1) { 361 syslog(LOG_ERR, "sysctl(restore_disrtcset): %m"); 362 return 1; 363 } 364 } 365 366 /****** End of critical section ******/ 367 368 if (init && wall_clock) { 369 sleep_mode = False; 370 /* wait for signals and acts like -a */ 371 (void) sigsuspend(&emask); 372 goto again; 373 } 374 375 return 0; 376 } 377 378 static void 379 usage() 380 { 381 fprintf(stderr, "%s\n%s\n%s\n%s\n", 382 "usage: adjkerntz -i", 383 "\t\t(initial call from /etc/rc)", 384 " adjkerntz -a [-s]", 385 "\t\t(adjustment call, -s for sleep/retry mode)"); 386 exit(2); 387 } 388