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8980 BIOS clock is sometimes one hour fast
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: C Fraire <cfraire@me.com>


   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*

  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28 
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <sys/types.h>
  33 #include <sys/sysi86.h>
  34 #include <errno.h>
  35 #include <time.h>
  36 #include <string.h>
  37 #include <sys/stat.h>
  38 






  39 static char *progname;
  40 static char *zonefile = "/etc/rtc_config";
  41 static FILE *zonefptr;
  42 static char zone_info[256];
  43 static char zone_lag[256];
  44 static char tz[256] = "TZ=";

  45 int debug = 0;

  46 int lag;
  47 int errors_ok = 0; /* allow "rtc no-args" to be quiet when not configured */
  48 static time_t clock_val;
  49 static char zone_comment[] =
  50         "#\n"
  51         "#      This file (%s) contains information used to manage the\n"
  52         "#      x86 real time clock hardware.  The hardware is kept in\n"
  53         "#      the machine's local time for compatibility with other x86\n"
  54         "#      operating systems.  This file is read by the kernel at\n"
  55         "#      boot time.  It is set and updated by the /usr/sbin/rtc\n"
  56         "#      command.  The 'zone_info' field designates the local\n"
  57         "#      time zone.  The 'zone_lag' field indicates the number\n"
  58         "#      of seconds between local time and Greenwich Mean Time.\n"
  59         "#\n";
  60 
  61 /*
  62  *      Open the configuration file and extract the
  63  *      zone_info and the zone_lag.  Return 0 if successful.
  64  */
  65 int


 139         if (debug)
 140                 (void) fprintf(stderr, "zone_info = %s,   zone_lag = %s\n",
 141                     zone_info, zone_lag);
 142         if (debug)
 143                 (void) fprintf(stderr, "lag (decimal) is %d\n", lag);
 144 
 145         (void) fclose(zonefptr);
 146         zonefptr = NULL;
 147         return (0);
 148 }
 149 
 150 void
 151 display_zone_string(void)
 152 {
 153         if (open_zonefile() == 0)
 154                 (void) printf("%s\n", zone_info);
 155         else
 156                 (void) printf("GMT\n");
 157 }
 158 
 159 long
 160 set_zone(char *zone_string)
 161 {
 162         struct tm *tm;
 163         long current_lag;
 164 
 165         (void) umask(0022);
 166         if ((zonefptr = fopen(zonefile, "w")) == NULL) {
 167                 (void) fprintf(stderr, "%s: cannot open %s: errno = %d\n",
 168                         progname, zonefile, errno);
 169                 return (0);
 170         }
 171 
 172         tz[3] = 0;
 173         (void) strncat(tz, zone_string, 253);
 174         if (debug)
 175                 (void) fprintf(stderr, "Time Zone string is '%s'\n", tz);
 176 
 177         (void) putenv(tz);
 178         if (debug)
 179                 (void) system("env | grep TZ");
 180 
 181         (void) time(&clock_val);
 182 
 183         tm = localtime(&clock_val);
 184         current_lag = tm->tm_isdst ? altzone : timezone;






























 185         if (debug)
 186                 (void) printf("%s DST.    Lag is %ld.\n", tm->tm_isdst ? "Is" :
 187                     "Is NOT",  tm->tm_isdst ? altzone : timezone);
 188 
 189         (void) fprintf(zonefptr, zone_comment, zonefile);
 190         (void) fprintf(zonefptr, "zone_info=%s\n", zone_string);
 191         (void) fprintf(zonefptr, "zone_lag=%ld\n",
 192             tm->tm_isdst ? altzone : timezone);
 193         (void) fclose(zonefptr);
 194         zonefptr = NULL;
 195         return (current_lag);
 196 }
 197 
 198 void
 199 correct_rtc_and_lag()
 200 {
 201         struct tm *tm;
 202         long kernels_lag;
 203         long current_lag;
 204 
 205         if (open_zonefile())
 206                 return;
 207 
 208         tz[3] = 0;
 209         (void) strncat(tz, zone_info, 253);
 210         if (debug)
 211                 (void) fprintf(stderr, "Time Zone string is '%s'\n", tz);









 212 
 213         (void) putenv(tz);
 214         if (debug)
 215                 (void) system("env | grep TZ");
 216 
 217         (void) time(&clock_val);
 218         tm = localtime(&clock_val);
 219         current_lag = tm->tm_isdst ? altzone : timezone;
 220 
 221         if (current_lag != lag) {       /* if file is wrong */
 222                 if (debug)
 223                         (void) fprintf(stderr, "correcting file");
 224                 (void) set_zone(zone_info);     /* then rewrite file */
 225         }
 226 
 227         (void) sysi86(GGMTL, &kernels_lag);
 228         if (current_lag != kernels_lag) {
 229                 if (debug)
 230                         (void) fprintf(stderr, "correcting kernel's lag");
 231                 (void) sysi86(SGMTL, current_lag);      /* correct the lag */
 232                 (void) sysi86(WTODC);                   /* set the rtc to */
 233                                                         /* new local time */
 234         }
 235 }
 236 
 237 void
 238 initialize_zone(char *zone_string)
 239 {
 240         long current_lag;
 241 
 242         /* write the config file */
 243         current_lag = set_zone(zone_string);
 244 
 245         /* correct the lag */
 246         (void) sysi86(SGMTL, current_lag);
 247 
 248         /*
 249          * set the unix time from the rtc,
 250          * assuming the rtc was the correct
 251          * local time.
 252          */
 253         (void) sysi86(RTCSYNC);
 254 }
 255 
 256 void
 257 usage()
 258 {
 259         static char Usage[] = "Usage:\n\
 260 rtc [-c] [-z time_zone] [-?]\n";
 261 
 262         (void) fprintf(stderr, Usage);
 263 }
 264 
 265 void
 266 verbose_usage()
 267 {
 268         static char Usage1[] = "\
 269         Options:\n\




 270             -c\t\tCheck and correct for daylight savings time rollover.\n\
 271             -z [zone]\tRecord the zone info in the config file.\n";
 272 
 273         (void) fprintf(stderr, Usage1);
 274 }
 275 





























 276 int
 277 main(int argc, char *argv[])
 278 {
 279         int c;


 280 
 281         progname = argv[0];
 282 
 283         if (argc == 1) {
 284                 errors_ok = 1;
 285                 display_zone_string();

 286         }
 287 
 288         while ((c = getopt(argc, argv, "cz:d")) != EOF) {
 289                 switch (c) {
 290                 case 'c':
 291                         correct_rtc_and_lag();
 292                         continue;
 293                 case 'z':
 294                         initialize_zone(optarg);
 295                         continue;
 296                 case 'd':
 297                         debug = 1;
 298                         continue;











 299                 case '?':
 300                         verbose_usage();
 301                         return (0);
 302                 default:
 303                         usage();
 304                         return (1);
 305                 }
 306         }
 307         return (0);






 308 }


   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2018 Gary Mills
  24  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  25  * Use is subject to license terms.
  26  */
  27 


  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <unistd.h>
  31 #include <sys/types.h>
  32 #include <sys/sysi86.h>
  33 #include <errno.h>
  34 #include <time.h>
  35 #include <string.h>
  36 #include <sys/stat.h>
  37 
  38 /* RTC modes */
  39 #define M_UNSET 0 /* Mode never set */
  40 #define M_VAR   1 /* Tracks local time including DST */
  41 #define M_UTC   2 /* Clock runs in UTC */
  42 #define M_STD   3 /* Clock runs in local standard time */
  43 
  44 static char *progname;
  45 static char *zonefile = "/etc/rtc_config";
  46 static FILE *zonefptr;
  47 static char zone_info[256];
  48 static char zone_lag[256];
  49 static char tz[256] = "TZ=";
  50 static char *utc_zone = "UTC";
  51 int debug = 0;
  52 int rtc_mode = M_UNSET;
  53 int lag;
  54 int errors_ok = 0; /* allow "rtc no-args" to be quiet when not configured */
  55 static time_t clock_val;
  56 static char zone_comment[] =
  57         "#\n"
  58         "#      This file (%s) contains information used to manage the\n"
  59         "#      x86 real time clock hardware.  The hardware is kept in\n"
  60         "#      the machine's local time for compatibility with other x86\n"
  61         "#      operating systems.  This file is read by the kernel at\n"
  62         "#      boot time.  It is set and updated by the /usr/sbin/rtc\n"
  63         "#      command.  The 'zone_info' field designates the local\n"
  64         "#      time zone.  The 'zone_lag' field indicates the number\n"
  65         "#      of seconds between local time and Greenwich Mean Time.\n"
  66         "#\n";
  67 
  68 /*
  69  *      Open the configuration file and extract the
  70  *      zone_info and the zone_lag.  Return 0 if successful.
  71  */
  72 int


 146         if (debug)
 147                 (void) fprintf(stderr, "zone_info = %s,   zone_lag = %s\n",
 148                     zone_info, zone_lag);
 149         if (debug)
 150                 (void) fprintf(stderr, "lag (decimal) is %d\n", lag);
 151 
 152         (void) fclose(zonefptr);
 153         zonefptr = NULL;
 154         return (0);
 155 }
 156 
 157 void
 158 display_zone_string(void)
 159 {
 160         if (open_zonefile() == 0)
 161                 (void) printf("%s\n", zone_info);
 162         else
 163                 (void) printf("GMT\n");
 164 }
 165 
 166 int
 167 get_local(char *z)
 168 {
 169         struct tm *tm;

 170 







 171         tz[3] = 0;
 172         (void) strncat(tz, z, 253);
 173         if (debug)
 174                 (void) fprintf(stderr, "Time Zone string is '%s'\n", tz);
 175 
 176         (void) putenv(tz);
 177         if (debug)
 178                 (void) system("env | grep TZ");
 179 
 180         (void) time(&clock_val);
 181 
 182         tm = localtime(&clock_val);
 183         return (tm->tm_isdst);
 184 }
 185 
 186 long
 187 set_zone(char *zone_string)
 188 {
 189         int isdst;
 190         long current_lag;
 191 
 192         (void) umask(0022);
 193         if ((zonefptr = fopen(zonefile, "w")) == NULL) {
 194                 (void) fprintf(stderr, "%s: cannot open %s: errno = %d\n",
 195                     progname, zonefile, errno);
 196                 return (0);
 197         }
 198 
 199         switch (rtc_mode) {
 200         case M_VAR:
 201                 isdst = get_local(zone_string);
 202                 current_lag = isdst ? altzone : timezone;
 203                 break;
 204         case M_STD:
 205                 isdst = get_local(zone_string);
 206                 current_lag = timezone;
 207                 break;
 208         default:        /* Includes M_UTC */
 209                 isdst = 0;
 210                 current_lag = 0;
 211                 zone_string = utc_zone;
 212                 break;
 213         }
 214         if (debug)
 215                 (void) printf("%s DST.    Lag is %ld.\n", isdst ? "Is" :
 216                     "Is NOT",  current_lag);
 217 
 218         (void) fprintf(zonefptr, zone_comment, zonefile);
 219         (void) fprintf(zonefptr, "zone_info=%s\n", zone_string);
 220         (void) fprintf(zonefptr, "zone_lag=%ld\n", current_lag);

 221         (void) fclose(zonefptr);
 222         zonefptr = NULL;
 223         return (current_lag);
 224 }
 225 
 226 void
 227 correct_rtc_and_lag()
 228 {
 229         int isdst;
 230         long kernels_lag;
 231         long current_lag;
 232 
 233         if (open_zonefile())
 234                 return;
 235 
 236         switch (rtc_mode) {
 237         case M_VAR:
 238                 isdst = get_local(zone_info);
 239                 current_lag = isdst ? altzone : timezone;
 240                 break;
 241         case M_STD:
 242                 (void) get_local(zone_info);
 243                 current_lag = timezone;
 244                 break;
 245         default:        /* Includes M_UTC */
 246                 current_lag = 0;
 247                 break;
 248         }
 249 








 250         if (current_lag != lag) {       /* if file is wrong */
 251                 if (debug)
 252                         (void) fprintf(stderr, "correcting file\n");
 253                 (void) set_zone(zone_info);     /* then rewrite file */
 254         }
 255 
 256         (void) sysi86(GGMTL, &kernels_lag);
 257         if (current_lag != kernels_lag) {
 258                 if (debug)
 259                         (void) fprintf(stderr, "correcting kernel's lag\n");
 260                 (void) sysi86(SGMTL, current_lag);      /* correct the lag */
 261                 (void) sysi86(WTODC);                   /* set the rtc to */
 262                                                         /* new local time */
 263         }
 264 }
 265 
 266 void
 267 initialize_zone(char *zone_string)
 268 {
 269         long current_lag;
 270 
 271         /* write the config file */
 272         current_lag = set_zone(zone_string);
 273 
 274         /* correct the lag */
 275         (void) sysi86(SGMTL, current_lag);
 276 
 277         /*
 278          * set the unix time from the rtc,
 279          * assuming the rtc was the correct
 280          * local time.
 281          */
 282         (void) sysi86(RTCSYNC);
 283 }
 284 
 285 void
 286 usage()
 287 {
 288         static char Usage[] = "Usage:\n\
 289 rtc [-w] [-s|-u|-v] [-c] [-z time_zone] [-?]\n";
 290 
 291         (void) fprintf(stderr, Usage);
 292 }
 293 
 294 void
 295 verbose_usage()
 296 {
 297         static char Usage1[] = "\
 298         Options:\n\
 299             -w\t\tDoes nothing.\n\
 300             -s\t\tRTC runs in local standard time.\n\
 301             -u\t\tRTC runs in UTC time.\n\
 302             -v\t\tRTC tracks local time (with cron command).\n\
 303             -c\t\tCheck and correct for daylight savings time rollover.\n\
 304             -z [zone]\tRecord the zone info in the config file.\n";
 305 
 306         (void) fprintf(stderr, Usage1);
 307 }
 308 
 309 void
 310 set_default()
 311 {
 312         switch (rtc_mode) {
 313         default:        /* Includes M_UNSET */
 314                 rtc_mode = M_VAR;
 315                 break;
 316         case M_VAR:
 317                 /*FALLTHROUGH*/
 318         case M_UTC:
 319                 /*FALLTHROUGH*/
 320         case M_STD:
 321                 break;
 322         }
 323 }
 324 
 325 void
 326 check_mode(int letter, int mode)
 327 {
 328         if (rtc_mode == M_UNSET || rtc_mode == mode) {
 329                 rtc_mode = mode;
 330                 return;
 331         }
 332         (void) fprintf(stderr, "%s: option -%c conflicts with other options\n",
 333             progname, letter);
 334         exit(1);
 335 }
 336 
 337 
 338 int
 339 main(int argc, char *argv[])
 340 {
 341         int c;
 342         int cflg = 0;
 343         char *zone_name = NULL;
 344 
 345         progname = argv[0];
 346 
 347         if (argc == 1) {
 348                 errors_ok = 1;
 349                 display_zone_string();
 350                 exit(0);
 351         }
 352 
 353         while ((c = getopt(argc, argv, "suvwcz:d")) != EOF) {
 354                 switch (c) {
 355                 case 'c':
 356                         cflg++;
 357                         continue;
 358                 case 'z':
 359                         zone_name = optarg;
 360                         continue;
 361                 case 'd':
 362                         debug = 1;
 363                         continue;
 364                 case 's':       /* standard: RTC runs local standard time */
 365                         check_mode(c, M_STD);
 366                         continue;
 367                 case 'u':       /* utc: RTC runs UTC time */
 368                         check_mode(c, M_UTC);
 369                         continue;
 370                 case 'v':       /* varies: RTC tracks local time */
 371                         check_mode(c, M_VAR);
 372                         continue;
 373                 case 'w':       /* Does nothing */
 374                         continue;
 375                 case '?':
 376                         verbose_usage();
 377                         exit(0);
 378                 default:
 379                         usage();
 380                         exit(1);
 381                 }
 382         }
 383         set_default();
 384         if (zone_name != NULL)
 385                 initialize_zone(zone_name);
 386         if (cflg > 0)
 387                 correct_rtc_and_lag();
 388         exit(0);
 389         /*LINTED*/
 390 }