1 /* 2 * CDDL HEADER START 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 73 open_zonefile() 74 { 75 char b[256], *s; 76 int lag_hrs; 77 78 if ((zonefptr = fopen(zonefile, "r")) == NULL) { 79 if (errors_ok == 0) 80 (void) fprintf(stderr, 81 "%s: cannot open %s: errno = %d\n", 82 progname, zonefile, errno); 83 return (1); 84 } 85 86 for (;;) { 87 if ((s = fgets(b, sizeof (b), zonefptr)) == NULL) 88 break; 89 if ((s = strchr(s, 'z')) == NULL) 90 continue; 91 if (strncmp(s, "zone_info", 9) == 0) { 92 s += 9; 93 while (*s != 0 && *s != '=') 94 s++; 95 if (*s == '=') { 96 s++; 97 while (*s != 0 && (*s == ' ' || *s == '\t')) 98 s++; 99 (void) strncpy(zone_info, s, 100 sizeof (zone_info)); 101 s = zone_info; 102 while (*s != 0 && *s != '\n') 103 s++; 104 if (*s == '\n') 105 *s = 0; 106 } 107 } else if (strncmp(s, "zone_lag", 8) == 0) { 108 s += 8; 109 while (*s != 0 && *s != '=') 110 s++; 111 if (*s == '=') { 112 s++; 113 while (*s != 0 && (*s == ' ' || *s == '\t')) 114 s++; 115 (void) strncpy(zone_lag, s, sizeof (zone_lag)); 116 s = zone_lag; 117 while (*s != 0 && *s != '\n') 118 s++; 119 if (*s == '\n') 120 *s = 0; 121 } 122 } 123 } 124 lag = atoi(zone_lag); 125 lag_hrs = lag / 3600; 126 if (zone_info[0] == 0) { 127 (void) fprintf(stderr, "%s: zone_info field is invalid\n", 128 progname); 129 zone_info[0] = 0; 130 zone_lag[0] = 0; 131 return (1); 132 } 133 if (zone_lag[0] == 0) { 134 (void) fprintf(stderr, "%s: zone_lag field is invalid\n", 135 progname); 136 zone_lag[0] = 0; 137 return (1); 138 } 139 if ((lag_hrs < -24) || (lag_hrs > 24)) { 140 (void) fprintf(stderr, "%s: a GMT lag of %d is out of range\n", 141 progname, lag_hrs); 142 zone_info[0] = 0; 143 zone_lag[0] = 0; 144 return (1); 145 } 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 } 391