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Commit | Line | Data |
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7eda085c KZ |
1 | /* |
2 | * hwclock.c | |
3 | * | |
4 | * clock.c was written by Charles Hedrick, hedrick@cs.rutgers.edu, Apr 1992 | |
5 | * Modified for clock adjustments - Rob Hooft <hooft@chem.ruu.nl>, Nov 1992 | |
6 | * Improvements by Harald Koenig <koenig@nova.tat.physik.uni-tuebingen.de> | |
7 | * and Alan Modra <alan@spri.levels.unisa.edu.au>. | |
8 | * | |
9 | * Major rewrite by Bryan Henderson <bryanh@giraffe-data.com>, 96.09.19. | |
10 | * The new program is called hwclock. New features: | |
11 | * - You can set the hardware clock without also modifying the system clock. | |
12 | * - You can read and set the clock with finer than 1 second precision. | |
13 | * - When you set the clock, hwclock automatically refigures the drift | |
14 | * rate, based on how far off the clock was before you set it. | |
15 | * | |
16 | * Reshuffled things, added sparc code, and re-added alpha stuff | |
17 | * by David Mosberger <davidm@azstarnet.com> | |
9abb2685 | 18 | * and Jay Estabrook <jestabro@amt.tay1.dec.com> |
7eda085c KZ |
19 | * and Martin Ostermann <ost@coments.rwth-aachen.de>, aeb@cwi.nl, 990212. |
20 | * | |
21 | * Fix for Award 2094 bug, Dave Coffin (dcoffin@shore.net) 11/12/98 | |
22853e4a | 22 | * Change of local time handling, Stefan Ring <e9725446@stud3.tuwien.ac.at> |
63cccae4 | 23 | * Change of adjtime handling, James P. Rutledge <ao112@rgfn.epcc.edu>. |
66ee8158 KZ |
24 | * |
25 | * Distributed under GPL | |
7eda085c KZ |
26 | */ |
27 | ||
28 | /* | |
29 | * clock [-u] -r - read hardware clock | |
30 | * clock [-u] -w - write hardware clock from system time | |
31 | * clock [-u] -s - set system time from hardware clock | |
32 | * clock [-u] -a - set system time from hardware clock, adjust the time | |
33 | * to correct for systematic error, and write it back to | |
34 | * the hardware clock | |
35 | * -u indicates cmos clock is kept in universal time | |
36 | * -A indicates cmos clock is kept in Alpha ARC console time (0 == 1980) | |
37 | * -J indicates we're dealing with a Jensen (early DEC Alpha PC) | |
38 | */ | |
39 | ||
40 | /* | |
41 | * Explanation of `adjusting' (Rob Hooft): | |
42 | * | |
43 | * The problem with my machine is that its CMOS clock is 10 seconds | |
44 | * per day slow. With this version of clock.c, and my '/etc/rc.local' | |
45 | * reading '/etc/clock -au' instead of '/etc/clock -u -s', this error | |
46 | * is automatically corrected at every boot. | |
47 | * | |
48 | * To do this job, the program reads and writes the file '/etc/adjtime' | |
49 | * to determine the correction, and to save its data. In this file are | |
50 | * three numbers: | |
51 | * | |
52 | * 1) the correction in seconds per day. (So if your clock runs 5 | |
53 | * seconds per day fast, the first number should read -5.0) | |
54 | * 2) the number of seconds since 1/1/1970 the last time the program | |
55 | * was used | |
56 | * 3) the remaining part of a second which was leftover after the last | |
57 | * adjustment | |
58 | * | |
59 | * Installation and use of this program: | |
60 | * | |
61 | * a) create a file '/etc/adjtime' containing as the first and only line: | |
62 | * '0.0 0 0.0' | |
63 | * b) run 'clock -au' or 'clock -a', depending on whether your cmos is in | |
64 | * universal or local time. This updates the second number. | |
65 | * c) set your system time using the 'date' command. | |
66 | * d) update your cmos time using 'clock -wu' or 'clock -w' | |
67 | * e) replace the first number in /etc/adjtime by your correction. | |
68 | * f) put the command 'clock -au' or 'clock -a' in your '/etc/rc.local' | |
69 | */ | |
70 | ||
71 | #include <string.h> | |
72 | #include <stdio.h> | |
73 | #include <fcntl.h> | |
74 | #include <sys/ioctl.h> | |
75 | #include <errno.h> | |
76 | #include <stdlib.h> | |
77 | #include <unistd.h> | |
78 | #include <time.h> | |
79 | #include <sys/time.h> | |
80 | #include <sys/stat.h> | |
eb63b9b8 | 81 | #include <stdarg.h> |
63cccae4 KZ |
82 | #include <getopt.h> |
83 | #include <sysexits.h> | |
7eda085c KZ |
84 | |
85 | #include "clock.h" | |
7eda085c KZ |
86 | #include "nls.h" |
87 | ||
88058a71 KZ |
88 | #ifdef HAVE_LIBAUDIT |
89 | #include <libaudit.h> | |
90 | static int hwaudit_fd = -1; | |
91 | static int hwaudit_on; | |
92 | #endif | |
93 | ||
7eda085c | 94 | #define MYNAME "hwclock" |
7eda085c KZ |
95 | |
96 | char *progname = MYNAME; | |
97 | ||
98 | /* The struct that holds our hardware access routines */ | |
99 | struct clock_ops *ur; | |
100 | ||
101 | #define FLOOR(arg) ((arg >= 0 ? (int) arg : ((int) arg) - 1)); | |
102 | ||
103 | /* Here the information for time adjustments is kept. */ | |
104 | #define ADJPATH "/etc/adjtime" | |
105 | ||
106 | /* Store the date here when "badyear" flag is set. */ | |
107 | #define LASTDATE "/var/lib/lastdate" | |
108 | ||
109 | struct adjtime { | |
110 | /* This is information we keep in the adjtime file that tells us how | |
111 | to do drift corrections. Elements are all straight from the | |
112 | adjtime file, so see documentation of that file for details. | |
113 | Exception is <dirty>, which is an indication that what's in this | |
114 | structure is not what's in the disk file (because it has been | |
9abb2685 | 115 | updated since read from the disk file). |
7eda085c | 116 | */ |
eb63b9b8 | 117 | bool dirty; |
63cccae4 | 118 | |
eb63b9b8 | 119 | /* line 1 */ |
9abb2685 | 120 | double drift_factor; |
7eda085c | 121 | time_t last_adj_time; |
63cccae4 KZ |
122 | double not_adjusted; |
123 | ||
eb63b9b8 | 124 | /* line 2 */ |
7eda085c | 125 | time_t last_calib_time; |
eb63b9b8 KZ |
126 | /* The most recent time that we set the clock from an external |
127 | authority (as opposed to just doing a drift adjustment) */ | |
63cccae4 | 128 | |
eb63b9b8 KZ |
129 | /* line 3 */ |
130 | enum a_local_utc {LOCAL, UTC, UNKNOWN} local_utc; | |
131 | /* To which time zone, local or UTC, we most recently set the | |
132 | hardware clock. */ | |
7eda085c KZ |
133 | }; |
134 | ||
135 | bool debug; | |
136 | /* We are running in debug mode, wherein we put a lot of information about | |
137 | what we're doing to standard output. */ | |
138 | ||
139 | bool badyear; | |
140 | /* Workaround for Award 4.50g BIOS bug: keep the year in a file. */ | |
141 | ||
22853e4a KZ |
142 | int epoch_option = -1; |
143 | /* User-specified epoch, used when rtc fails to return epoch. */ | |
144 | ||
7eda085c KZ |
145 | /* |
146 | * Almost all Award BIOS's made between 04/26/94 and 05/31/95 | |
147 | * have a nasty bug limiting the RTC year byte to the range 94-99. | |
148 | * Any year between 2000 and 2093 gets changed to 2094, every time | |
149 | * you start the system. | |
150 | * With the --badyear option, we write the date to file and hope | |
151 | * that the file is updated at least once a year. | |
152 | * I recommend putting this command "hwclock --badyear" in the monthly | |
153 | * crontab, just to be safe. -- Dave Coffin 11/12/98 | |
154 | */ | |
22853e4a | 155 | static void |
7eda085c KZ |
156 | write_date_to_file (struct tm *tm) { |
157 | FILE *fp; | |
158 | ||
159 | if ((fp = fopen(LASTDATE,"w"))) { | |
160 | fprintf(fp,"%02d.%02d.%04d\n", tm->tm_mday, tm->tm_mon+1, | |
161 | tm->tm_year+1900); | |
162 | fclose(fp); | |
163 | } else | |
164 | perror(LASTDATE); | |
165 | } | |
166 | ||
22853e4a | 167 | static void |
7eda085c KZ |
168 | read_date_from_file (struct tm *tm) { |
169 | int last_mday, last_mon, last_year; | |
170 | FILE *fp; | |
171 | ||
172 | if ((fp = fopen(LASTDATE,"r"))) { | |
173 | if (fscanf (fp,"%d.%d.%d\n", &last_mday, &last_mon, &last_year) == 3) { | |
174 | tm->tm_year = last_year-1900; | |
175 | if ((tm->tm_mon << 5) + tm->tm_mday < ((last_mon-1) << 5) + last_mday) | |
176 | tm->tm_year ++; | |
177 | } | |
178 | fclose(fp); | |
179 | } | |
180 | write_date_to_file (tm); | |
181 | } | |
182 | ||
9abb2685 | 183 | static double |
7eda085c KZ |
184 | time_diff(struct timeval subtrahend, struct timeval subtractor) { |
185 | /*--------------------------------------------------------------------------- | |
186 | The difference in seconds between two times in "timeval" format. | |
187 | ----------------------------------------------------------------------------*/ | |
63cccae4 KZ |
188 | return (subtrahend.tv_sec - subtractor.tv_sec) |
189 | + (subtrahend.tv_usec - subtractor.tv_usec) / 1E6; | |
7eda085c KZ |
190 | } |
191 | ||
192 | ||
193 | static struct timeval | |
63cccae4 | 194 | time_inc(struct timeval addend, double increment) { |
7eda085c KZ |
195 | /*---------------------------------------------------------------------------- |
196 | The time, in "timeval" format, which is <increment> seconds after | |
197 | the time <addend>. Of course, <increment> may be negative. | |
198 | -----------------------------------------------------------------------------*/ | |
199 | struct timeval newtime; | |
200 | ||
201 | newtime.tv_sec = addend.tv_sec + (int) increment; | |
202 | newtime.tv_usec = addend.tv_usec + (increment - (int) increment) * 1E6; | |
203 | ||
204 | /* Now adjust it so that the microsecond value is between 0 and 1 million */ | |
205 | if (newtime.tv_usec < 0) { | |
206 | newtime.tv_usec += 1E6; | |
207 | newtime.tv_sec -= 1; | |
208 | } else if (newtime.tv_usec >= 1E6) { | |
209 | newtime.tv_usec -= 1E6; | |
210 | newtime.tv_sec += 1; | |
211 | } | |
63cccae4 | 212 | return newtime; |
7eda085c KZ |
213 | } |
214 | ||
215 | ||
eb63b9b8 KZ |
216 | static bool |
217 | hw_clock_is_utc(const bool utc, const bool local_opt, | |
218 | const struct adjtime adjtime) { | |
219 | bool ret; | |
220 | ||
221 | if (utc) | |
222 | ret = TRUE; /* --utc explicitly given on command line */ | |
223 | else if (local_opt) | |
224 | ret = FALSE; /* --localtime explicitly given */ | |
225 | else | |
226 | /* get info from adjtime file - default is local */ | |
227 | ret = (adjtime.local_utc == UTC); | |
228 | if (debug) | |
229 | printf(_("Assuming hardware clock is kept in %s time.\n"), | |
230 | ret ? _("UTC") : _("local")); | |
231 | return ret; | |
232 | } | |
233 | ||
234 | ||
7eda085c | 235 | |
63cccae4 KZ |
236 | static int |
237 | read_adjtime(struct adjtime *adjtime_p) { | |
7eda085c KZ |
238 | /*---------------------------------------------------------------------------- |
239 | Read the adjustment parameters out of the /etc/adjtime file. | |
240 | ||
241 | Return them as the adjtime structure <*adjtime_p>. | |
7eda085c KZ |
242 | If there is no /etc/adjtime file, return defaults. |
243 | If values are missing from the file, return defaults for them. | |
9abb2685 | 244 | |
63cccae4 | 245 | return value 0 if all OK, !=0 otherwise. |
7eda085c KZ |
246 | |
247 | -----------------------------------------------------------------------------*/ | |
248 | FILE *adjfile; | |
249 | int rc; /* local return code */ | |
250 | struct stat statbuf; /* We don't even use the contents of this. */ | |
251 | ||
63cccae4 KZ |
252 | rc = stat(ADJPATH, &statbuf); |
253 | if (rc < 0 && errno == ENOENT) { | |
254 | /* He doesn't have a adjtime file, so we'll use defaults. */ | |
255 | adjtime_p->drift_factor = 0; | |
256 | adjtime_p->last_adj_time = 0; | |
257 | adjtime_p->not_adjusted = 0; | |
258 | adjtime_p->last_calib_time = 0; | |
259 | adjtime_p->local_utc = UNKNOWN; | |
260 | ||
261 | return 0; | |
262 | } | |
7eda085c | 263 | |
7eda085c KZ |
264 | adjfile = fopen(ADJPATH, "r"); /* open file for reading */ |
265 | if (adjfile == NULL) { | |
266 | outsyserr("cannot open file " ADJPATH); | |
63cccae4 KZ |
267 | return EX_OSFILE; |
268 | } | |
269 | ||
270 | { | |
7eda085c KZ |
271 | char line1[81]; /* String: first line of adjtime file */ |
272 | char line2[81]; /* String: second line of adjtime file */ | |
eb63b9b8 | 273 | char line3[81]; /* String: third line of adjtime file */ |
364cda48 | 274 | long timeval; |
9abb2685 | 275 | |
7eda085c KZ |
276 | line1[0] = '\0'; /* In case fgets fails */ |
277 | fgets(line1, sizeof(line1), adjfile); | |
278 | line2[0] = '\0'; /* In case fgets fails */ | |
279 | fgets(line2, sizeof(line2), adjfile); | |
eb63b9b8 KZ |
280 | line3[0] = '\0'; /* In case fgets fails */ |
281 | fgets(line3, sizeof(line3), adjfile); | |
9abb2685 | 282 | |
7eda085c | 283 | fclose(adjfile); |
9abb2685 | 284 | |
7eda085c KZ |
285 | /* Set defaults in case values are missing from file */ |
286 | adjtime_p->drift_factor = 0; | |
287 | adjtime_p->last_adj_time = 0; | |
288 | adjtime_p->not_adjusted = 0; | |
289 | adjtime_p->last_calib_time = 0; | |
364cda48 | 290 | timeval = 0; |
9abb2685 KZ |
291 | |
292 | sscanf(line1, "%lf %ld %lf", | |
7eda085c | 293 | &adjtime_p->drift_factor, |
9abb2685 | 294 | &timeval, |
7eda085c | 295 | &adjtime_p->not_adjusted); |
364cda48 KZ |
296 | adjtime_p->last_adj_time = timeval; |
297 | ||
298 | sscanf(line2, "%ld", &timeval); | |
299 | adjtime_p->last_calib_time = timeval; | |
eb63b9b8 KZ |
300 | |
301 | if (!strcmp(line3, "UTC\n")) | |
302 | adjtime_p->local_utc = UTC; | |
303 | else if (!strcmp(line3, "LOCAL\n")) | |
304 | adjtime_p->local_utc = LOCAL; | |
305 | else { | |
306 | adjtime_p->local_utc = UNKNOWN; | |
307 | if (line3[0]) { | |
e8f26419 KZ |
308 | fprintf(stderr, |
309 | _("%s: Warning: unrecognized third line in adjtime file\n"), | |
eb63b9b8 KZ |
310 | MYNAME); |
311 | fprintf(stderr, _("(Expected: `UTC' or `LOCAL' or nothing.)\n")); | |
312 | } | |
313 | } | |
7eda085c KZ |
314 | } |
315 | adjtime_p->dirty = FALSE; | |
316 | ||
317 | if (debug) { | |
9abb2685 | 318 | printf(_("Last drift adjustment done at %ld seconds after 1969\n"), |
364cda48 KZ |
319 | (long) adjtime_p->last_adj_time); |
320 | printf(_("Last calibration done at %ld seconds after 1969\n"), | |
321 | (long) adjtime_p->last_calib_time); | |
eb63b9b8 KZ |
322 | printf(_("Hardware clock is on %s time\n"), |
323 | (adjtime_p->local_utc == LOCAL) ? _("local") : | |
324 | (adjtime_p->local_utc == UTC) ? _("UTC") : _("unknown")); | |
7eda085c | 325 | } |
63cccae4 KZ |
326 | |
327 | return 0; | |
7eda085c KZ |
328 | } |
329 | ||
330 | ||
63cccae4 KZ |
331 | static int |
332 | synchronize_to_clock_tick(void) { | |
7eda085c KZ |
333 | /*----------------------------------------------------------------------------- |
334 | Wait until the falling edge of the Hardware Clock's update flag so | |
335 | that any time that is read from the clock immediately after we | |
336 | return will be exact. | |
337 | ||
338 | The clock only has 1 second precision, so it gives the exact time only | |
339 | once per second, right on the falling edge of the update flag. | |
340 | ||
341 | We wait (up to one second) either blocked waiting for an rtc device | |
9abb2685 | 342 | or in a CPU spin loop. The former is probably not very accurate. |
7eda085c | 343 | |
63cccae4 | 344 | Return 0 if it worked, nonzero if it didn't. |
7eda085c | 345 | -----------------------------------------------------------------------------*/ |
63cccae4 | 346 | int rc; |
7eda085c | 347 | |
63cccae4 | 348 | if (debug) printf(_("Waiting for clock tick...\n")); |
7eda085c | 349 | |
63cccae4 KZ |
350 | rc = ur->synchronize_to_clock_tick(); |
351 | ||
352 | if (debug) printf(_("...got clock tick\n")); | |
353 | ||
354 | return rc; | |
7eda085c KZ |
355 | } |
356 | ||
357 | ||
358 | ||
359 | static void | |
9abb2685 | 360 | mktime_tz(struct tm tm, const bool universal, |
7eda085c KZ |
361 | bool *valid_p, time_t *systime_p) { |
362 | /*----------------------------------------------------------------------------- | |
363 | Convert a time in broken down format (hours, minutes, etc.) into standard | |
364 | unix time (seconds into epoch). Return it as *systime_p. | |
365 | ||
366 | The broken down time is argument <tm>. This broken down time is either in | |
367 | local time zone or UTC, depending on value of logical argument "universal". | |
368 | True means it is in UTC. | |
369 | ||
370 | If the argument contains values that do not constitute a valid time, | |
371 | and mktime() recognizes this, return *valid_p == false and | |
372 | *systime_p undefined. However, mktime() sometimes goes ahead and | |
373 | computes a fictional time "as if" the input values were valid, | |
374 | e.g. if they indicate the 31st day of April, mktime() may compute | |
375 | the time of May 1. In such a case, we return the same fictional | |
376 | value mktime() does as *systime_p and return *valid_p == true. | |
377 | ||
378 | -----------------------------------------------------------------------------*/ | |
379 | time_t mktime_result; /* The value returned by our mktime() call */ | |
380 | char *zone; /* Local time zone name */ | |
381 | ||
9abb2685 KZ |
382 | /* We use the C library function mktime(), but since it only works on |
383 | local time zone input, we may have to fake it out by temporarily | |
7eda085c KZ |
384 | changing the local time zone to UTC. |
385 | */ | |
ffc43748 | 386 | zone = getenv("TZ"); /* remember original time zone */ |
7eda085c KZ |
387 | if (universal) { |
388 | /* Set timezone to UTC */ | |
389 | setenv("TZ", "", TRUE); | |
390 | /* Note: tzset() gets called implicitly by the time code, but only the | |
391 | first time. When changing the environment variable, better call | |
392 | tzset() explicitly. | |
393 | */ | |
394 | tzset(); | |
395 | } | |
396 | mktime_result = mktime(&tm); | |
397 | if (mktime_result == -1) { | |
398 | /* This apparently (not specified in mktime() documentation) means | |
399 | the 'tm' structure does not contain valid values (however, not | |
400 | containing valid values does _not_ imply mktime() returns -1). | |
401 | */ | |
402 | *valid_p = FALSE; | |
403 | *systime_p = 0; | |
404 | if (debug) | |
405 | printf(_("Invalid values in hardware clock: " | |
22853e4a KZ |
406 | "%4d/%.2d/%.2d %.2d:%.2d:%.2d\n"), |
407 | tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, | |
408 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
7eda085c KZ |
409 | } else { |
410 | *valid_p = TRUE; | |
411 | *systime_p = mktime_result; | |
9abb2685 | 412 | if (debug) |
22853e4a KZ |
413 | printf(_("Hw clock time : %4d/%.2d/%.2d %.2d:%.2d:%.2d = " |
414 | "%ld seconds since 1969\n"), | |
415 | tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, | |
416 | tm.tm_hour, tm.tm_min, tm.tm_sec, (long) *systime_p); | |
7eda085c KZ |
417 | } |
418 | /* now put back the original zone. */ | |
419 | if (zone) setenv("TZ", zone, TRUE); | |
420 | else unsetenv("TZ"); | |
421 | tzset(); | |
422 | } | |
423 | ||
424 | ||
425 | static void | |
426 | read_hardware_clock(const bool universal, bool *valid_p, time_t *systime_p){ | |
427 | /*---------------------------------------------------------------------------- | |
428 | Read the hardware clock and return the current time via <tm> argument. | |
429 | ||
430 | Use the method indicated by <method> argument to access the hardware clock. | |
431 | -----------------------------------------------------------------------------*/ | |
432 | struct tm tm; | |
433 | int err; | |
434 | ||
435 | err = ur->read_hardware_clock(&tm); | |
436 | ||
437 | if (badyear) | |
438 | read_date_from_file(&tm); | |
439 | ||
440 | if (debug) | |
22853e4a KZ |
441 | printf (_("Time read from Hardware Clock: %4d/%.2d/%.2d %02d:%02d:%02d\n"), |
442 | tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, | |
7eda085c KZ |
443 | tm.tm_hour, tm.tm_min, tm.tm_sec); |
444 | mktime_tz(tm, universal, valid_p, systime_p); | |
445 | } | |
446 | ||
447 | ||
448 | static void | |
9abb2685 KZ |
449 | set_hardware_clock(const time_t newtime, |
450 | const bool universal, | |
7eda085c KZ |
451 | const bool testing) { |
452 | /*---------------------------------------------------------------------------- | |
453 | Set the Hardware Clock to the time <newtime>, in local time zone or UTC, | |
454 | according to <universal>. | |
455 | ----------------------------------------------------------------------------*/ | |
456 | int err; | |
9abb2685 | 457 | struct tm new_broken_time; |
7eda085c KZ |
458 | /* Time to which we will set Hardware Clock, in broken down format, in |
459 | the time zone of caller's choice | |
460 | */ | |
461 | ||
462 | if (universal) | |
463 | new_broken_time = *gmtime(&newtime); | |
464 | else | |
465 | new_broken_time = *localtime(&newtime); | |
466 | ||
9abb2685 | 467 | if (debug) |
7eda085c | 468 | printf(_("Setting Hardware Clock to %.2d:%.2d:%.2d " |
9abb2685 KZ |
469 | "= %ld seconds since 1969\n"), |
470 | new_broken_time.tm_hour, new_broken_time.tm_min, | |
364cda48 | 471 | new_broken_time.tm_sec, (long) newtime); |
7eda085c KZ |
472 | |
473 | if (testing) | |
474 | printf(_("Clock not changed - testing only.\n")); | |
475 | else { | |
476 | if (badyear) { | |
477 | /* | |
478 | * Write the real year to a file, then write a fake year | |
479 | * between 1995 and 1998 to the RTC. This way, Award BIOS boots | |
480 | * on 29 Feb 2000 thinking that it's 29 Feb 1996. | |
481 | */ | |
482 | write_date_to_file (&new_broken_time); | |
483 | new_broken_time.tm_year = 95 + ((new_broken_time.tm_year+1) & 3); | |
484 | } | |
485 | err = ur->set_hardware_clock(&new_broken_time); | |
486 | } | |
487 | } | |
488 | ||
489 | ||
490 | ||
491 | static void | |
9abb2685 | 492 | set_hardware_clock_exact(const time_t sethwtime, |
95f1bdee | 493 | const struct timeval refsystime, |
9abb2685 | 494 | const bool universal, |
7eda085c KZ |
495 | const bool testing) { |
496 | /*---------------------------------------------------------------------------- | |
95f1bdee | 497 | Set the Hardware Clock to the time "sethwtime", in local time zone or UTC, |
7eda085c KZ |
498 | according to "universal". |
499 | ||
95f1bdee KZ |
500 | Wait for a fraction of a second so that "sethwtime" is the value of |
501 | the Hardware Clock as of system time "refsystime", which is in the past. | |
502 | For example, if "sethwtime" is 14:03:05 and "refsystime" is 12:10:04.5 | |
503 | and the current system time is 12:10:06.0: Wait .5 seconds (to make | |
504 | exactly 2 seconds since "refsystime") and then set the Hardware Clock | |
505 | to 14:03:07, thus getting a precise and retroactive setting of the clock. | |
7eda085c KZ |
506 | |
507 | (Don't be confused by the fact that the system clock and the Hardware | |
9abb2685 | 508 | Clock differ by two hours in the above example. That's just to remind |
7eda085c KZ |
509 | you that there are two independent time scales here). |
510 | ||
511 | This function ought to be able to accept set times as fractional times. | |
512 | Idea for future enhancement. | |
7eda085c | 513 | -----------------------------------------------------------------------------*/ |
7eda085c | 514 | |
95f1bdee KZ |
515 | time_t newhwtime; |
516 | struct timeval beginsystime, nowsystime; | |
517 | ||
518 | time_resync: | |
519 | gettimeofday(&beginsystime, NULL); | |
520 | newhwtime = sethwtime + (int) time_diff(beginsystime, refsystime) + 1; | |
9abb2685 | 521 | if (debug) |
7eda085c KZ |
522 | printf(_("Time elapsed since reference time has been %.6f seconds.\n" |
523 | "Delaying further to reach the next full second.\n"), | |
95f1bdee | 524 | time_diff(beginsystime, refsystime)); |
9abb2685 | 525 | |
99c392d8 KZ |
526 | /* |
527 | * Now delay some more until Hardware Clock time newhwtime arrives. The -500 | |
528 | * ms is because the Hardware Clock always sets to your set time plus 500 ms | |
529 | * (because it is designed to update to the next second precisely 500 ms | |
530 | * after you finish the setting). | |
531 | */ | |
95f1bdee KZ |
532 | do { |
533 | float tdiff; | |
534 | gettimeofday(&nowsystime, NULL); | |
535 | tdiff = time_diff(nowsystime, beginsystime); | |
536 | if (tdiff < 0) | |
537 | goto time_resync; /* probably time was reset */ | |
99c392d8 | 538 | } while (time_diff(nowsystime, refsystime) - 0.5 < newhwtime - sethwtime); |
9abb2685 | 539 | |
95f1bdee | 540 | set_hardware_clock(newhwtime, universal, testing); |
7eda085c KZ |
541 | } |
542 | ||
543 | ||
544 | ||
545 | static void | |
9abb2685 | 546 | display_time(const bool hclock_valid, const time_t systime, |
63cccae4 | 547 | const double sync_duration) { |
7eda085c KZ |
548 | /*---------------------------------------------------------------------------- |
549 | Put the time "systime" on standard output in display format. | |
550 | Except if hclock_valid == false, just tell standard output that we don't | |
551 | know what time it is. | |
552 | ||
553 | Include in the output the adjustment "sync_duration". | |
554 | -----------------------------------------------------------------------------*/ | |
555 | if (!hclock_valid) | |
556 | fprintf(stderr, _("The Hardware Clock registers contain values that are " | |
557 | "either invalid (e.g. 50th day of month) or beyond the range " | |
558 | "we can handle (e.g. Year 2095).\n")); | |
559 | else { | |
66ee8158 KZ |
560 | struct tm *lt; |
561 | char *format = "%c"; | |
562 | char ctime_now[200]; | |
7eda085c | 563 | |
66ee8158 KZ |
564 | lt = localtime(&systime); |
565 | strftime(ctime_now, sizeof(ctime_now), format, lt); | |
7eda085c KZ |
566 | printf(_("%s %.6f seconds\n"), ctime_now, -(sync_duration)); |
567 | } | |
568 | } | |
569 | ||
570 | ||
571 | ||
572 | static int | |
573 | interpret_date_string(const char *date_opt, time_t * const time_p) { | |
574 | /*---------------------------------------------------------------------------- | |
575 | Interpret the value of the --date option, which is something like | |
576 | "13:05:01". In fact, it can be any of the myriad ASCII strings that specify | |
577 | a time which the "date" program can understand. The date option value in | |
9abb2685 | 578 | question is our "dateopt" argument. |
7eda085c KZ |
579 | |
580 | The specified time is in the local time zone. | |
581 | ||
582 | Our output, "*time_p", is a seconds-into-epoch time. | |
583 | ||
584 | We use the "date" program to interpret the date string. "date" must be | |
585 | runnable by issuing the command "date" to the /bin/sh shell. That means | |
586 | in must be in the current PATH. | |
587 | ||
588 | If anything goes wrong (and many things can), we return return code | |
589 | 10 and arbitrary *time_p. Otherwise, return code is 0 and *time_p | |
590 | is valid. | |
591 | ----------------------------------------------------------------------------*/ | |
e8f26419 KZ |
592 | FILE *date_child_fp; |
593 | char date_resp[100]; | |
594 | const char magic[]="seconds-into-epoch="; | |
9abb2685 | 595 | char date_command[100]; |
e8f26419 KZ |
596 | int retcode; /* our eventual return code */ |
597 | int rc; /* local return code */ | |
598 | ||
599 | if (date_opt == NULL) { | |
600 | fprintf(stderr, _("No --date option specified.\n")); | |
601 | return 14; | |
602 | } | |
7eda085c | 603 | |
e8f26419 KZ |
604 | /* prevent overflow - a security risk */ |
605 | if (strlen(date_opt) > sizeof(date_command) - 50) { | |
606 | fprintf(stderr, _("--date argument too long\n")); | |
607 | return 13; | |
608 | } | |
609 | ||
610 | /* Quotes in date_opt would ruin the date command we construct. */ | |
611 | if (strchr(date_opt, '"') != NULL) { | |
612 | fprintf(stderr, | |
613 | _("The value of the --date option is not a valid date.\n" | |
614 | "In particular, it contains quotation marks.\n")); | |
615 | return 12; | |
616 | } | |
617 | ||
9abb2685 | 618 | sprintf(date_command, "date --date=\"%s\" +seconds-into-epoch=%%s", |
e8f26419 KZ |
619 | date_opt); |
620 | if (debug) | |
621 | printf(_("Issuing date command: %s\n"), date_command); | |
622 | ||
623 | date_child_fp = popen(date_command, "r"); | |
624 | if (date_child_fp == NULL) { | |
625 | outsyserr(_("Unable to run 'date' program in /bin/sh shell. " | |
626 | "popen() failed")); | |
627 | return 10; | |
628 | } | |
629 | ||
630 | date_resp[0] = '\0'; /* in case fgets fails */ | |
631 | fgets(date_resp, sizeof(date_resp), date_child_fp); | |
632 | if (debug) | |
633 | printf(_("response from date command = %s\n"), date_resp); | |
634 | if (strncmp(date_resp, magic, sizeof(magic)-1) != 0) { | |
635 | fprintf(stderr, _("The date command issued by %s returned " | |
636 | "unexpected results.\n" | |
637 | "The command was:\n %s\n" | |
9abb2685 | 638 | "The response was:\n %s\n"), |
e8f26419 KZ |
639 | MYNAME, date_command, date_resp); |
640 | retcode = 8; | |
641 | } else { | |
642 | long seconds_since_epoch; | |
643 | rc = sscanf(date_resp + sizeof(magic)-1, "%ld", | |
644 | &seconds_since_epoch); | |
645 | if (rc < 1) { | |
646 | fprintf(stderr, | |
647 | _("The date command issued by %s returned " | |
648 | "something other than an integer where the " | |
649 | "converted time value was expected.\n" | |
650 | "The command was:\n %s\n" | |
651 | "The response was:\n %s\n"), | |
652 | MYNAME, date_command, date_resp); | |
653 | retcode = 6; | |
654 | } else { | |
655 | retcode = 0; | |
656 | *time_p = seconds_since_epoch; | |
9abb2685 | 657 | if (debug) |
e8f26419 KZ |
658 | printf(_("date string %s equates to " |
659 | "%ld seconds since 1969.\n"), | |
660 | date_opt, (long) *time_p); | |
661 | } | |
662 | } | |
663 | fclose(date_child_fp); | |
664 | ||
63cccae4 | 665 | return retcode; |
7eda085c KZ |
666 | } |
667 | ||
7eda085c | 668 | |
9abb2685 KZ |
669 | |
670 | static int | |
671 | set_system_clock(const bool hclock_valid, const time_t newtime, | |
7eda085c KZ |
672 | const bool testing) { |
673 | /*---------------------------------------------------------------------------- | |
674 | Set the System Clock to time 'newtime'. | |
675 | ||
9abb2685 | 676 | Also set the kernel time zone value to the value indicated by the |
7eda085c | 677 | TZ environment variable and/or /usr/lib/zoneinfo/, interpreted as |
eb63b9b8 | 678 | tzset() would interpret them. |
7eda085c KZ |
679 | |
680 | EXCEPT: if hclock_valid is false, just issue an error message | |
681 | saying there is no valid time in the Hardware Clock to which to set | |
682 | the system time. | |
683 | ||
9abb2685 | 684 | If 'testing' is true, don't actually update anything -- just say we |
7eda085c KZ |
685 | would have. |
686 | -----------------------------------------------------------------------------*/ | |
eb63b9b8 | 687 | int retcode; |
7eda085c KZ |
688 | |
689 | if (!hclock_valid) { | |
63cccae4 | 690 | fprintf(stderr, _("The Hardware Clock does not contain a valid time, so " |
7eda085c KZ |
691 | "we cannot set the System Time from it.\n")); |
692 | retcode = 1; | |
693 | } else { | |
694 | struct timeval tv; | |
22853e4a KZ |
695 | struct tm *broken; |
696 | int minuteswest; | |
eb63b9b8 | 697 | int rc; |
9abb2685 | 698 | |
7eda085c KZ |
699 | tv.tv_sec = newtime; |
700 | tv.tv_usec = 0; | |
9abb2685 | 701 | |
22853e4a | 702 | broken = localtime(&newtime); |
48d7b13a | 703 | #ifdef HAVE_TM_GMTOFF |
22853e4a KZ |
704 | minuteswest = -broken->tm_gmtoff/60; /* GNU extension */ |
705 | #else | |
706 | minuteswest = timezone/60; | |
707 | if (broken->tm_isdst) | |
708 | minuteswest -= 60; | |
709 | #endif | |
9abb2685 | 710 | |
7eda085c | 711 | if (debug) { |
63cccae4 KZ |
712 | printf(_("Calling settimeofday:\n")); |
713 | printf(_("\ttv.tv_sec = %ld, tv.tv_usec = %ld\n"), | |
714 | (long) tv.tv_sec, (long) tv.tv_usec); | |
715 | printf(_("\ttz.tz_minuteswest = %d\n"), minuteswest); | |
7eda085c KZ |
716 | } |
717 | if (testing) { | |
718 | printf(_("Not setting system clock because running in test mode.\n")); | |
719 | retcode = 0; | |
720 | } else { | |
22853e4a | 721 | const struct timezone tz = { minuteswest, 0 }; |
eb63b9b8 | 722 | |
7eda085c | 723 | rc = settimeofday(&tv, &tz); |
63cccae4 KZ |
724 | if (rc) { |
725 | if (errno == EPERM) { | |
726 | fprintf(stderr, | |
727 | _("Must be superuser to set system clock.\n")); | |
728 | retcode = EX_NOPERM; | |
729 | } else { | |
730 | outsyserr(_("settimeofday() failed")); | |
731 | retcode = 1; | |
732 | } | |
7eda085c KZ |
733 | } else retcode = 0; |
734 | } | |
735 | } | |
63cccae4 | 736 | return retcode; |
7eda085c KZ |
737 | } |
738 | ||
739 | ||
740 | static void | |
741 | adjust_drift_factor(struct adjtime *adjtime_p, | |
9abb2685 | 742 | const time_t nowtime, |
63cccae4 KZ |
743 | const bool hclock_valid, |
744 | const time_t hclocktime, | |
745 | const double sync_delay) { | |
746 | /*------------------------------------------------------------------------ | |
7eda085c KZ |
747 | Update the drift factor in <*adjtime_p> to reflect the fact that the |
748 | Hardware Clock was calibrated to <nowtime> and before that was set | |
749 | to <hclocktime>. | |
750 | ||
7eda085c KZ |
751 | We record in the adjtime file the time at which we last calibrated |
752 | the clock so we can compute the drift rate each time we calibrate. | |
753 | ||
754 | EXCEPT: if <hclock_valid> is false, assume Hardware Clock was not set | |
755 | before to anything meaningful and regular adjustments have not been | |
756 | done, so don't adjust the drift factor. | |
63cccae4 KZ |
757 | ------------------------------------------------------------------------*/ |
758 | if (!hclock_valid) { | |
759 | if (debug) | |
760 | printf(_("Not adjusting drift factor because the " | |
761 | "Hardware Clock previously contained " | |
762 | "garbage.\n")); | |
763 | } else if (adjtime_p->last_calib_time == 0) { | |
764 | if (debug) | |
765 | printf(_("Not adjusting drift factor because last " | |
766 | "calibration time is zero,\n" | |
767 | "so history is bad and calibration startover " | |
768 | "is necessary.\n")); | |
769 | } else if ((hclocktime - adjtime_p->last_calib_time) < 23 * 60 * 60) { | |
770 | if (debug) | |
771 | printf(_("Not adjusting drift factor because it has " | |
772 | "been less than a day since the last " | |
773 | "calibration.\n")); | |
774 | } else if (adjtime_p->last_calib_time != 0) { | |
775 | /* | |
776 | * At adjustment time we adjust the hardware clock according | |
777 | * to the contents of /etc/adjtime. | |
778 | * | |
779 | * At calibration time we set the hardware clock and | |
780 | * update /etc/adjtime, that is, for each calibration | |
781 | * (except the first) we also do an adjustment. | |
782 | * | |
783 | * We are now at calibration time. | |
784 | * | |
785 | * Let us do computation in doubles. (Floats almost suffice, | |
786 | * but 195 days + 1 second equals 195 days in floats.) | |
787 | */ | |
788 | const double sec_per_day = 24.0 * 60.0 * 60.0; | |
789 | double atime_per_htime; | |
790 | double adj_days, cal_days; | |
791 | double exp_drift, unc_drift; | |
792 | double factor_adjust; | |
793 | ||
794 | /* Adjusted time units per hardware time unit */ | |
795 | atime_per_htime = 1.0 + adjtime_p->drift_factor / sec_per_day; | |
796 | ||
797 | /* Days since last adjustment (in hardware clock time) */ | |
798 | adj_days = (double)(hclocktime - adjtime_p->last_adj_time) | |
799 | / sec_per_day; | |
800 | ||
801 | /* Expected drift (sec) since last adjustment */ | |
802 | exp_drift = adj_days * adjtime_p->drift_factor | |
803 | + adjtime_p->not_adjusted; | |
804 | ||
805 | /* Uncorrected drift (sec) since last calibration */ | |
806 | unc_drift = (double)(nowtime - hclocktime) | |
807 | + sync_delay - exp_drift; | |
808 | ||
809 | /* Days since last calibration (in hardware clock time) */ | |
810 | cal_days = ((double)(adjtime_p->last_adj_time | |
811 | - adjtime_p->last_calib_time) | |
812 | + adjtime_p->not_adjusted) | |
813 | / (sec_per_day * atime_per_htime) + adj_days; | |
814 | ||
815 | /* Amount to add to previous drift factor */ | |
816 | factor_adjust = unc_drift / cal_days; | |
817 | ||
818 | if (debug) | |
819 | printf(_("Clock drifted %.1f seconds in the past " | |
820 | "%d seconds in spite of a drift factor of " | |
821 | "%f seconds/day.\n" | |
822 | "Adjusting drift factor by %f seconds/day\n"), | |
823 | unc_drift, | |
824 | (int) (nowtime - adjtime_p->last_calib_time), | |
825 | adjtime_p->drift_factor, | |
826 | factor_adjust); | |
9abb2685 | 827 | |
63cccae4 KZ |
828 | adjtime_p->drift_factor += factor_adjust; |
829 | } | |
830 | adjtime_p->last_calib_time = nowtime; | |
9abb2685 | 831 | |
63cccae4 | 832 | adjtime_p->last_adj_time = nowtime; |
9abb2685 | 833 | |
63cccae4 | 834 | adjtime_p->not_adjusted = 0; |
9abb2685 | 835 | |
63cccae4 | 836 | adjtime_p->dirty = TRUE; |
7eda085c KZ |
837 | } |
838 | ||
839 | ||
840 | ||
841 | static void | |
63cccae4 | 842 | calculate_adjustment(const double factor, |
9abb2685 | 843 | const time_t last_time, |
63cccae4 | 844 | const double not_adjusted, |
7eda085c | 845 | const time_t systime, |
9abb2685 | 846 | int *adjustment_p, |
63cccae4 | 847 | double *retro_p, |
7eda085c KZ |
848 | const int debug ) { |
849 | /*---------------------------------------------------------------------------- | |
850 | Do the drift adjustment calculation. | |
851 | ||
852 | The way we have to set the clock, we need the adjustment in two parts: | |
853 | ||
854 | 1) an integer number of seconds (return as *adjustment_p) | |
9abb2685 | 855 | |
7eda085c KZ |
856 | 2) a positive fraction of a second (less than 1) (return as *retro_p) |
857 | ||
858 | The sum of these two values is the adjustment needed. Positive means to | |
859 | advance the clock or insert seconds. Negative means to retard the clock | |
860 | or remove seconds. | |
861 | ----------------------------------------------------------------------------*/ | |
63cccae4 | 862 | double exact_adjustment; |
7eda085c | 863 | |
63cccae4 | 864 | exact_adjustment = ((double) (systime - last_time)) * factor / (24 * 60 * 60) |
7eda085c KZ |
865 | + not_adjusted; |
866 | *adjustment_p = FLOOR(exact_adjustment); | |
9abb2685 | 867 | |
63cccae4 | 868 | *retro_p = exact_adjustment - (double) *adjustment_p; |
7eda085c KZ |
869 | if (debug) { |
870 | printf (_("Time since last adjustment is %d seconds\n"), | |
871 | (int) (systime - last_time)); | |
872 | printf (_("Need to insert %d seconds and refer time back " | |
873 | "%.6f seconds ago\n"), | |
874 | *adjustment_p, *retro_p); | |
875 | } | |
876 | } | |
877 | ||
878 | ||
879 | ||
880 | static void | |
881 | save_adjtime(const struct adjtime adjtime, const bool testing) { | |
882 | /*----------------------------------------------------------------------------- | |
883 | Write the contents of the <adjtime> structure to its disk file. | |
884 | ||
885 | But if the contents are clean (unchanged since read from disk), don't | |
886 | bother. | |
887 | -----------------------------------------------------------------------------*/ | |
eb63b9b8 | 888 | char newfile[412]; /* Stuff to write to disk file */ |
7eda085c KZ |
889 | |
890 | if (adjtime.dirty) { | |
891 | /* snprintf is not always available, but this is safe | |
892 | as long as libc does not use more than 100 positions for %ld or %f */ | |
eb63b9b8 | 893 | sprintf(newfile, "%f %ld %f\n%ld\n%s\n", |
7eda085c KZ |
894 | adjtime.drift_factor, |
895 | (long) adjtime.last_adj_time, | |
896 | adjtime.not_adjusted, | |
eb63b9b8 KZ |
897 | (long) adjtime.last_calib_time, |
898 | (adjtime.local_utc == UTC) ? "UTC" : "LOCAL"); | |
7eda085c KZ |
899 | |
900 | if (testing) { | |
901 | printf(_("Not updating adjtime file because of testing mode.\n")); | |
9abb2685 | 902 | printf(_("Would have written the following to %s:\n%s"), |
7eda085c KZ |
903 | ADJPATH, newfile); |
904 | } else { | |
905 | FILE *adjfile; | |
906 | int err = 0; | |
907 | ||
908 | adjfile = fopen(ADJPATH, "w"); | |
909 | if (adjfile == NULL) { | |
910 | outsyserr("Could not open file with the clock adjustment parameters " | |
911 | "in it (" ADJPATH ") for writing"); | |
912 | err = 1; | |
913 | } else { | |
66ee8158 | 914 | if (fputs(newfile, adjfile) < 0) { |
7eda085c KZ |
915 | outsyserr("Could not update file with the clock adjustment " |
916 | "parameters (" ADJPATH ") in it"); | |
917 | err = 1; | |
918 | } | |
919 | if (fclose(adjfile) < 0) { | |
920 | outsyserr("Could not update file with the clock adjustment " | |
921 | "parameters (" ADJPATH ") in it"); | |
922 | err = 1; | |
923 | } | |
924 | } | |
925 | if (err) | |
926 | fprintf(stderr, _("Drift adjustment parameters not updated.\n")); | |
927 | } | |
928 | } | |
929 | } | |
930 | ||
931 | ||
932 | ||
933 | static void | |
934 | do_adjustment(struct adjtime *adjtime_p, | |
9abb2685 | 935 | const bool hclock_valid, const time_t hclocktime, |
7eda085c KZ |
936 | const struct timeval read_time, |
937 | const bool universal, const bool testing) { | |
938 | /*--------------------------------------------------------------------------- | |
9abb2685 | 939 | Do the adjustment requested, by 1) setting the Hardware Clock (if |
7eda085c KZ |
940 | necessary), and 2) updating the last-adjusted time in the adjtime |
941 | structure. | |
942 | ||
943 | Do not update anything if the Hardware Clock does not currently present | |
944 | a valid time. | |
945 | ||
946 | arguments <factor> and <last_time> are current values from the adjtime | |
947 | file. | |
948 | ||
949 | <hclock_valid> means the Hardware Clock contains a valid time, and that | |
950 | time is <hclocktime>. | |
951 | ||
9abb2685 | 952 | <read_time> is the current system time (to be precise, it is the system |
7eda085c KZ |
953 | time at the time <hclocktime> was read, which due to computational delay |
954 | could be a short time ago). | |
955 | ||
956 | <universal>: the Hardware Clock is kept in UTC. | |
957 | ||
958 | <testing>: We are running in test mode (no updating of clock). | |
959 | ||
960 | We do not bother to update the clock if the adjustment would be less than | |
961 | one second. This is to avoid cumulative error and needless CPU hogging | |
962 | (remember we use an infinite loop for some timing) if the user runs us | |
963 | frequently. | |
964 | ||
965 | ----------------------------------------------------------------------------*/ | |
966 | if (!hclock_valid) { | |
967 | fprintf(stderr, _("The Hardware Clock does not contain a valid time, " | |
968 | "so we cannot adjust it.\n")); | |
63cccae4 KZ |
969 | adjtime_p->last_calib_time = 0; /* calibration startover is required */ |
970 | adjtime_p->last_adj_time = 0; | |
971 | adjtime_p->not_adjusted = 0; | |
972 | adjtime_p->dirty = TRUE; | |
973 | } else if (adjtime_p->last_adj_time == 0) { | |
974 | if (debug) | |
975 | printf("Not setting clock because last adjustment time is zero, " | |
976 | "so history is bad."); | |
7eda085c KZ |
977 | } else { |
978 | int adjustment; | |
979 | /* Number of seconds we must insert in the Hardware Clock */ | |
9abb2685 | 980 | double retro; |
7eda085c KZ |
981 | /* Fraction of second we have to remove from clock after inserting |
982 | <adjustment> whole seconds. | |
983 | */ | |
984 | calculate_adjustment(adjtime_p->drift_factor, | |
985 | adjtime_p->last_adj_time, | |
986 | adjtime_p->not_adjusted, | |
987 | hclocktime, | |
988 | &adjustment, &retro, | |
989 | debug ); | |
990 | if (adjustment > 0 || adjustment < -1) { | |
9abb2685 | 991 | set_hardware_clock_exact(hclocktime + adjustment, |
7eda085c KZ |
992 | time_inc(read_time, -retro), |
993 | universal, testing); | |
994 | adjtime_p->last_adj_time = hclocktime + adjustment; | |
995 | adjtime_p->not_adjusted = 0; | |
996 | adjtime_p->dirty = TRUE; | |
9abb2685 KZ |
997 | } else |
998 | if (debug) | |
7eda085c KZ |
999 | printf(_("Needed adjustment is less than one second, " |
1000 | "so not setting clock.\n")); | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | ||
1005 | ||
1006 | static void | |
1007 | determine_clock_access_method(const bool user_requests_ISA) { | |
1008 | ||
1009 | ur = NULL; | |
1010 | ||
1011 | if (user_requests_ISA) | |
1012 | ur = probe_for_cmos_clock(); | |
1013 | ||
1014 | if (!ur) | |
1015 | ur = probe_for_rtc_clock(); | |
1016 | ||
1017 | if (!ur) | |
1018 | ur = probe_for_kd_clock(); | |
1019 | ||
1020 | if (!ur && !user_requests_ISA) | |
1021 | ur = probe_for_cmos_clock(); | |
1022 | ||
1023 | if (debug) { | |
1024 | if (ur) | |
1025 | printf(_("Using %s.\n"), ur->interface_name); | |
1026 | else | |
1027 | printf(_("No usable clock interface found.\n")); | |
1028 | } | |
1029 | } | |
1030 | ||
63cccae4 | 1031 | static int |
364cda48 | 1032 | manipulate_clock(const bool show, const bool adjust, const bool noadjfile, |
7eda085c | 1033 | const bool set, const time_t set_time, |
9abb2685 KZ |
1034 | const bool hctosys, const bool systohc, |
1035 | const struct timeval startup_time, | |
eb63b9b8 | 1036 | const bool utc, const bool local_opt, |
63cccae4 | 1037 | const bool testing) { |
7eda085c KZ |
1038 | /*--------------------------------------------------------------------------- |
1039 | Do all the normal work of hwclock - read, set clock, etc. | |
1040 | ||
1041 | Issue output to stdout and error message to stderr where appropriate. | |
1042 | ||
1043 | Return rc == 0 if everything went OK, rc != 0 if not. | |
1044 | ----------------------------------------------------------------------------*/ | |
63cccae4 KZ |
1045 | struct adjtime adjtime; |
1046 | /* Contents of the adjtime file, or what they should be. */ | |
1047 | int rc; /* local return code */ | |
1048 | bool no_auth; /* User lacks necessary authorization to access the clock */ | |
1049 | ||
1050 | no_auth = ur->get_permissions(); | |
1051 | if (no_auth) | |
1052 | return EX_NOPERM; | |
1053 | ||
1054 | if (!noadjfile && (adjust || set || systohc || (!utc && !local_opt))) { | |
1055 | rc = read_adjtime(&adjtime); | |
1056 | if (rc) | |
1057 | return rc; | |
1058 | } else { | |
7eda085c | 1059 | /* A little trick to avoid reading the file if we don't have to */ |
9abb2685 | 1060 | adjtime.dirty = FALSE; |
7eda085c KZ |
1061 | rc = 0; |
1062 | } | |
63cccae4 KZ |
1063 | |
1064 | { | |
eb63b9b8 KZ |
1065 | const bool universal = hw_clock_is_utc(utc, local_opt, adjtime); |
1066 | ||
1067 | if ((set || systohc || adjust) && | |
1068 | (adjtime.local_utc == UTC) != universal) { | |
1069 | adjtime.local_utc = universal ? UTC : LOCAL; | |
1070 | adjtime.dirty = TRUE; | |
1071 | } | |
1072 | ||
63cccae4 KZ |
1073 | rc = synchronize_to_clock_tick(); /* this takes up to 1 second */ |
1074 | if (rc) | |
1075 | return rc; | |
1076 | ||
1077 | { | |
9abb2685 | 1078 | struct timeval read_time; |
7eda085c KZ |
1079 | /* The time at which we read the Hardware Clock */ |
1080 | ||
1081 | bool hclock_valid; | |
1082 | /* The Hardware Clock gives us a valid time, or at least something | |
1083 | close enough to fool mktime(). | |
1084 | */ | |
1085 | ||
1086 | time_t hclocktime; | |
1087 | /* The time the hardware clock had just after we | |
1088 | synchronized to its next clock tick when we started up. | |
1089 | Defined only if hclock_valid is true. | |
1090 | */ | |
9abb2685 | 1091 | |
7eda085c | 1092 | gettimeofday(&read_time, NULL); |
9abb2685 KZ |
1093 | read_hardware_clock(universal, &hclock_valid, &hclocktime); |
1094 | ||
7eda085c | 1095 | if (show) { |
9abb2685 | 1096 | display_time(hclock_valid, hclocktime, |
7eda085c | 1097 | time_diff(read_time, startup_time)); |
7eda085c | 1098 | } else if (set) { |
9abb2685 | 1099 | set_hardware_clock_exact(set_time, startup_time, |
7eda085c | 1100 | universal, testing); |
63cccae4 KZ |
1101 | adjust_drift_factor(&adjtime, set_time, hclock_valid, hclocktime, |
1102 | time_diff(read_time, startup_time)); | |
7eda085c | 1103 | } else if (adjust) { |
9abb2685 | 1104 | do_adjustment(&adjtime, hclock_valid, hclocktime, |
7eda085c | 1105 | read_time, universal, testing); |
7eda085c KZ |
1106 | } else if (systohc) { |
1107 | struct timeval nowtime, reftime; | |
1108 | /* We can only set_hardware_clock_exact to a whole seconds | |
1109 | time, so we set it with reference to the most recent | |
9abb2685 | 1110 | whole seconds time. |
7eda085c KZ |
1111 | */ |
1112 | gettimeofday(&nowtime, NULL); | |
1113 | reftime.tv_sec = nowtime.tv_sec; | |
1114 | reftime.tv_usec = 0; | |
9abb2685 KZ |
1115 | |
1116 | set_hardware_clock_exact((time_t) reftime.tv_sec, reftime, | |
7eda085c | 1117 | universal, testing); |
9abb2685 | 1118 | adjust_drift_factor(&adjtime, (time_t) reftime.tv_sec, hclock_valid, |
63cccae4 | 1119 | hclocktime, (double) read_time.tv_usec / 1E6); |
7eda085c KZ |
1120 | } else if (hctosys) { |
1121 | rc = set_system_clock(hclock_valid, hclocktime, testing); | |
63cccae4 | 1122 | if (rc) { |
7eda085c | 1123 | printf(_("Unable to set system clock.\n")); |
63cccae4 KZ |
1124 | return rc; |
1125 | } | |
7eda085c | 1126 | } |
63cccae4 | 1127 | if (!noadjfile) |
364cda48 | 1128 | save_adjtime(adjtime, testing); |
7eda085c KZ |
1129 | } |
1130 | } | |
63cccae4 | 1131 | return 0; |
7eda085c KZ |
1132 | } |
1133 | ||
1134 | ||
1135 | static void | |
9abb2685 | 1136 | manipulate_epoch(const bool getepoch, const bool setepoch, |
7eda085c KZ |
1137 | const int epoch_opt, const bool testing) { |
1138 | /*---------------------------------------------------------------------------- | |
1139 | Get or set the Hardware Clock epoch value in the kernel, as appropriate. | |
1140 | <getepoch>, <setepoch>, and <epoch> are hwclock invocation options. | |
1141 | ||
1142 | <epoch> == -1 if the user did not specify an "epoch" option. | |
1143 | ||
1144 | -----------------------------------------------------------------------------*/ | |
1145 | /* | |
9abb2685 | 1146 | Maintenance note: This should work on non-Alpha machines, but the |
7eda085c KZ |
1147 | evidence today (98.03.04) indicates that the kernel only keeps the |
1148 | epoch value on Alphas. If that is ever fixed, this function should be | |
1149 | changed. | |
1150 | */ | |
1151 | ||
1152 | #ifndef __alpha__ | |
1153 | fprintf(stderr, _("The kernel keeps an epoch value for the Hardware Clock " | |
1154 | "only on an Alpha machine.\nThis copy of hwclock was built for " | |
1155 | "a machine other than Alpha\n(and thus is presumably not running " | |
1156 | "on an Alpha now). No action taken.\n")); | |
1157 | #else | |
1158 | if (getepoch) { | |
1159 | unsigned long epoch; | |
1160 | ||
1161 | if (get_epoch_rtc(&epoch, 0)) | |
1162 | fprintf(stderr, _("Unable to get the epoch value from the kernel.\n")); | |
9abb2685 | 1163 | else |
7eda085c KZ |
1164 | printf(_("Kernel is assuming an epoch value of %lu\n"), epoch); |
1165 | } else if (setepoch) { | |
1166 | if (epoch_opt == -1) | |
1167 | fprintf(stderr, _("To set the epoch value, you must use the 'epoch' " | |
1168 | "option to tell to what value to set it.\n")); | |
1169 | else if (testing) | |
1170 | printf(_("Not setting the epoch to %d - testing only.\n"), | |
1171 | epoch_opt); | |
1172 | else if (set_epoch_rtc(epoch_opt)) | |
1173 | printf(_("Unable to set the epoch value in the kernel.\n")); | |
1174 | } | |
1175 | #endif | |
1176 | } | |
1177 | ||
48d7b13a | 1178 | #ifdef __ia64__ |
66ee8158 KZ |
1179 | #define RTC_DEV "/dev/efirtc" |
1180 | #else | |
1181 | #define RTC_DEV "/dev/rtc" | |
1182 | #endif | |
1183 | ||
63cccae4 KZ |
1184 | static void |
1185 | out_version(void) { | |
48d7b13a | 1186 | printf(_("%s from util-linux-%s\n"), MYNAME, PACKAGE_VERSION); |
63cccae4 KZ |
1187 | } |
1188 | ||
eb63b9b8 KZ |
1189 | /* |
1190 | usage - Output (error and) usage information | |
1191 | ||
9abb2685 KZ |
1192 | This function is called both directly from main to show usage |
1193 | information and as fatal function from shhopt if some argument is | |
1194 | not understood. In case of normal usage info FMT should be NULL. | |
1195 | In that case the info is printed to stdout. If FMT is given | |
1196 | usage will act like fprintf( stderr, fmt, ... ), show a usage | |
eb63b9b8 KZ |
1197 | information and terminate the program afterwards. |
1198 | */ | |
9abb2685 | 1199 | static void |
eb63b9b8 KZ |
1200 | usage( const char *fmt, ... ) { |
1201 | FILE *usageto; | |
1202 | va_list ap; | |
1203 | ||
1204 | usageto = fmt ? stderr : stdout; | |
1205 | ||
1206 | fprintf( usageto, _( | |
1207 | "hwclock - query and set the hardware clock (RTC)\n\n" | |
1208 | "Usage: hwclock [function] [options...]\n\n" | |
1209 | "Functions:\n" | |
1210 | " --help show this help\n" | |
1211 | " --show read hardware clock and print result\n" | |
1212 | " --set set the rtc to the time given with --date\n" | |
1213 | " --hctosys set the system time from the hardware clock\n" | |
1214 | " --systohc set the hardware clock to the current system time\n" | |
1215 | " --adjust adjust the rtc to account for systematic drift since \n" | |
1216 | " the clock was last set or adjusted\n" | |
1217 | " --getepoch print out the kernel's hardware clock epoch value\n" | |
1218 | " --setepoch set the kernel's hardware clock epoch value to the \n" | |
1219 | " value given with --epoch\n" | |
1220 | " --version print out the version of hwclock to stdout\n" | |
1221 | "\nOptions: \n" | |
1222 | " --utc the hardware clock is kept in coordinated universal time\n" | |
1223 | " --localtime the hardware clock is kept in local time\n" | |
88681c5f | 1224 | " --rtc=path special /dev/... file to use instead of default\n" |
66ee8158 | 1225 | " --directisa access the ISA bus directly instead of %s\n" |
eb63b9b8 KZ |
1226 | " --badyear ignore rtc's year because the bios is broken\n" |
1227 | " --date specifies the time to which to set the hardware clock\n" | |
1228 | " --epoch=year specifies the year which is the beginning of the \n" | |
1229 | " hardware clock's epoch value\n" | |
364cda48 KZ |
1230 | " --noadjfile do not access /etc/adjtime. Requires the use of\n" |
1231 | " either --utc or --localtime\n" | |
66ee8158 | 1232 | ),RTC_DEV); |
eb63b9b8 | 1233 | #ifdef __alpha__ |
63cccae4 | 1234 | fprintf(usageto, _( |
eb63b9b8 KZ |
1235 | " --jensen, --arc, --srm, --funky-toy\n" |
1236 | " tell hwclock the type of alpha you have (see hwclock(8))\n" | |
1237 | ) ); | |
1238 | #endif | |
1239 | ||
1240 | ||
1241 | fflush(stdout); | |
63cccae4 | 1242 | if (fmt) { |
eb63b9b8 KZ |
1243 | usageto = stderr; |
1244 | va_start(ap, fmt); | |
1245 | vfprintf(stderr, fmt, ap); | |
1246 | va_end(ap); | |
1247 | } | |
9abb2685 | 1248 | |
88058a71 | 1249 | hwclock_exit(fmt ? EX_USAGE : 0); |
eb63b9b8 KZ |
1250 | } |
1251 | ||
63cccae4 KZ |
1252 | static const struct option longopts[] = { |
1253 | { "adjust", 0, 0, 'a' }, | |
1254 | { "help", 0, 0, 'h' }, | |
1255 | { "show", 0, 0, 'r' }, | |
1256 | { "hctosys", 0, 0, 's' }, | |
1257 | { "utc", 0, 0, 'u' }, | |
1258 | { "version", 0, 0, 'v' }, | |
1259 | { "systohc", 0, 0, 'w' }, | |
1260 | { "debug", 0, 0, 'D' }, | |
1261 | #ifdef __alpha__ | |
1262 | { "ARC", 0, 0, 'A' }, | |
1263 | { "arc", 0, 0, 'A' }, | |
1264 | { "Jensen", 0, 0, 'J' }, | |
1265 | { "jensen", 0, 0, 'J' }, | |
1266 | { "SRM", 0, 0, 'S' }, | |
1267 | { "srm", 0, 0, 'S' }, | |
f0c8eda1 | 1268 | { "funky-toy", 0, 0, 'F'}, |
63cccae4 KZ |
1269 | #endif |
1270 | { "set", 0, 0, 128 }, | |
1271 | { "getepoch", 0, 0, 129 }, | |
1272 | { "setepoch", 0, 0, 130 }, | |
1273 | { "noadjfile", 0, 0, 131 }, | |
1274 | { "localtime", 0, 0, 132 }, | |
1275 | { "badyear", 0, 0, 133 }, | |
1276 | { "directisa", 0, 0, 134 }, | |
1277 | { "test", 0, 0, 135 }, | |
1278 | { "date", 1, 0, 136 }, | |
1279 | { "epoch", 1, 0, 137 }, | |
88681c5f | 1280 | { "rtc", 1, 0, 'f' }, |
63cccae4 KZ |
1281 | { NULL, 0, 0, 0 } |
1282 | }; | |
1283 | ||
1284 | /* | |
1285 | * Returns: | |
1286 | * EX_USAGE: bad invocation | |
1287 | * EX_NOPERM: no permission | |
1288 | * EX_OSFILE: cannot open /dev/rtc or /etc/adjtime | |
1289 | * EX_IOERR: ioctl error getting or setting the time | |
1290 | * 0: OK (or not) | |
1291 | * 1: failure | |
1292 | */ | |
9abb2685 | 1293 | int |
66ee8158 | 1294 | main(int argc, char **argv) { |
7eda085c | 1295 | |
63cccae4 KZ |
1296 | struct timeval startup_time; |
1297 | /* The time we started up, in seconds into the epoch, including | |
1298 | fractions. */ | |
1299 | time_t set_time; /* Time to which user said to set Hardware Clock */ | |
7eda085c | 1300 | |
63cccae4 KZ |
1301 | bool permitted; /* User is permitted to do the function */ |
1302 | int rc, c; | |
7eda085c | 1303 | |
63cccae4 KZ |
1304 | /* Variables set by various options; show may also be set later */ |
1305 | /* The options debug, badyear and epoch_option are global */ | |
1306 | bool show, set, systohc, hctosys, adjust, getepoch, setepoch; | |
1307 | bool utc, testing, local_opt, noadjfile, directisa; | |
1308 | bool ARCconsole, Jensen, SRM, funky_toy; | |
1309 | char *date_opt; | |
7eda085c | 1310 | |
63cccae4 KZ |
1311 | /* Remember what time we were invoked */ |
1312 | gettimeofday(&startup_time, NULL); | |
7eda085c | 1313 | |
88058a71 KZ |
1314 | #ifdef HAVE_LIBAUDIT |
1315 | hwaudit_fd = audit_open(); | |
1316 | if (hwaudit_fd < 0 && !(errno == EINVAL || errno == EPROTONOSUPPORT || | |
1317 | errno == EAFNOSUPPORT)) { | |
1318 | /* You get these error codes only when the kernel doesn't have | |
1319 | * audit compiled in. */ | |
1320 | fprintf(stderr, _("%s: Unable to connect to audit system\n"), | |
1321 | MYNAME); | |
1322 | return EX_NOPERM; | |
1323 | } | |
1324 | #endif | |
63cccae4 | 1325 | setlocale(LC_ALL, ""); |
66ee8158 | 1326 | #ifdef LC_NUMERIC |
63cccae4 KZ |
1327 | /* We need LC_CTYPE and LC_TIME and LC_MESSAGES, but must avoid |
1328 | LC_NUMERIC since it gives problems when we write to /etc/adjtime. | |
1329 | - gqueri@mail.dotcom.fr */ | |
1330 | setlocale(LC_NUMERIC, "C"); | |
66ee8158 | 1331 | #endif |
63cccae4 KZ |
1332 | bindtextdomain(PACKAGE, LOCALEDIR); |
1333 | textdomain(PACKAGE); | |
1334 | ||
1335 | /* Set option defaults */ | |
1336 | show = set = systohc = hctosys = adjust = noadjfile = FALSE; | |
1337 | getepoch = setepoch = utc = local_opt = testing = debug = FALSE; | |
1338 | ARCconsole = Jensen = SRM = funky_toy = directisa = badyear = FALSE; | |
1339 | date_opt = NULL; | |
1340 | ||
88681c5f | 1341 | while ((c = getopt_long (argc, argv, "?hvVDarsuwAJSFf:", longopts, NULL)) |
63cccae4 KZ |
1342 | != -1) { |
1343 | switch (c) { | |
1344 | case 'D': | |
1345 | debug = TRUE; | |
1346 | break; | |
1347 | case 'a': | |
1348 | adjust = TRUE; | |
1349 | break; | |
1350 | case 'r': | |
1351 | show = TRUE; | |
1352 | break; | |
1353 | case 's': | |
1354 | hctosys = TRUE; | |
1355 | break; | |
1356 | case 'u': | |
1357 | utc = TRUE; | |
1358 | break; | |
1359 | case 'w': | |
1360 | systohc = TRUE; | |
1361 | break; | |
1362 | #ifdef __alpha__ | |
1363 | case 'A': | |
1364 | ARCconsole = TRUE; | |
1365 | break; | |
1366 | case 'J': | |
1367 | Jensen = TRUE; | |
1368 | break; | |
1369 | case 'S': | |
1370 | SRM = TRUE; | |
1371 | break; | |
1372 | case 'F': | |
1373 | funky_toy = TRUE; | |
1374 | break; | |
1375 | #endif | |
1376 | case 128: | |
1377 | set = TRUE; | |
1378 | break; | |
1379 | case 129: | |
1380 | getepoch = TRUE; | |
1381 | break; | |
1382 | case 130: | |
1383 | setepoch = TRUE; | |
1384 | break; | |
1385 | case 131: | |
1386 | noadjfile = TRUE; | |
1387 | break; | |
1388 | case 132: | |
1389 | local_opt = TRUE; /* --localtime */ | |
1390 | break; | |
1391 | case 133: | |
1392 | badyear = TRUE; | |
1393 | break; | |
1394 | case 134: | |
1395 | directisa = TRUE; | |
1396 | break; | |
1397 | case 135: | |
1398 | testing = TRUE; /* --test */ | |
1399 | break; | |
1400 | case 136: | |
1401 | date_opt = optarg; /* --date */ | |
1402 | break; | |
1403 | case 137: | |
1404 | epoch_option = atoi(optarg); /* --epoch */ | |
1405 | break; | |
88681c5f KZ |
1406 | case 'f': |
1407 | rtc_dev_name = optarg; /* --rtc */ | |
1408 | break; | |
63cccae4 KZ |
1409 | case 'v': /* --version */ |
1410 | case 'V': | |
1411 | out_version(); | |
1412 | return 0; | |
1413 | case 'h': /* --help */ | |
1414 | case '?': | |
1415 | default: | |
1416 | usage(NULL); | |
1417 | } | |
1418 | } | |
7eda085c | 1419 | |
63cccae4 KZ |
1420 | argc -= optind; |
1421 | argv += optind; | |
eb63b9b8 | 1422 | |
88058a71 KZ |
1423 | #ifdef HAVE_LIBAUDIT |
1424 | if (testing != TRUE) { | |
1425 | if (adjust == TRUE || hctosys == TRUE || systohc == TRUE || | |
1426 | set == TRUE || setepoch == TRUE) { | |
1427 | hwaudit_on = TRUE; | |
1428 | } | |
1429 | } | |
1430 | #endif | |
63cccae4 KZ |
1431 | if (argc > 0) { |
1432 | usage(_("%s takes no non-option arguments. " | |
1433 | "You supplied %d.\n"), | |
1434 | MYNAME, argc); | |
1435 | } | |
7eda085c | 1436 | |
63cccae4 KZ |
1437 | if (show + set + systohc + hctosys + adjust + getepoch + setepoch > 1){ |
1438 | fprintf(stderr, _("You have specified multiple functions.\n" | |
1439 | "You can only perform one function " | |
1440 | "at a time.\n")); | |
88058a71 | 1441 | hwclock_exit(EX_USAGE); |
63cccae4 | 1442 | } |
eb63b9b8 | 1443 | |
63cccae4 KZ |
1444 | if (utc && local_opt) { |
1445 | fprintf(stderr, _("%s: The --utc and --localtime options " | |
1446 | "are mutually exclusive. You specified " | |
1447 | "both.\n"), MYNAME); | |
88058a71 | 1448 | hwclock_exit(EX_USAGE); |
63cccae4 | 1449 | } |
364cda48 | 1450 | |
63cccae4 KZ |
1451 | if (adjust && noadjfile) { |
1452 | fprintf(stderr, _("%s: The --adjust and --noadjfile options " | |
1453 | "are mutually exclusive. You specified " | |
1454 | "both.\n"), MYNAME); | |
88058a71 | 1455 | hwclock_exit(EX_USAGE); |
63cccae4 KZ |
1456 | } |
1457 | ||
1458 | if (noadjfile && !(utc || local_opt)) { | |
1459 | fprintf(stderr, _("%s: With --noadjfile, you must specify " | |
1460 | "either --utc or --localtime\n"), MYNAME); | |
88058a71 | 1461 | hwclock_exit(EX_USAGE); |
63cccae4 | 1462 | } |
364cda48 | 1463 | |
7eda085c | 1464 | #ifdef __alpha__ |
63cccae4 KZ |
1465 | set_cmos_epoch(ARCconsole, SRM); |
1466 | set_cmos_access(Jensen, funky_toy); | |
7eda085c KZ |
1467 | #endif |
1468 | ||
63cccae4 KZ |
1469 | if (set) { |
1470 | rc = interpret_date_string(date_opt, &set_time); | |
1471 | /* (time-consuming) */ | |
1472 | if (rc != 0) { | |
1473 | fprintf(stderr, _("No usable set-to time. " | |
1474 | "Cannot set clock.\n")); | |
88058a71 | 1475 | hwclock_exit(EX_USAGE); |
63cccae4 KZ |
1476 | } |
1477 | } | |
7eda085c | 1478 | |
9abb2685 | 1479 | if (!(show | set | systohc | hctosys | adjust | getepoch | setepoch)) |
63cccae4 | 1480 | show = 1; /* default to show */ |
7eda085c | 1481 | |
9abb2685 | 1482 | |
63cccae4 KZ |
1483 | if (getuid() == 0) |
1484 | permitted = TRUE; | |
1485 | else { | |
1486 | /* program is designed to run setuid (in some situations) */ | |
1487 | if (set || hctosys || systohc || adjust) { | |
9abb2685 | 1488 | fprintf(stderr, |
63cccae4 KZ |
1489 | _("Sorry, only the superuser can change " |
1490 | "the Hardware Clock.\n")); | |
1491 | permitted = FALSE; | |
1492 | } else if (hctosys) { | |
1493 | fprintf(stderr, | |
1494 | _("Sorry, only the superuser can change " | |
1495 | "the System Clock.\n")); | |
1496 | permitted = FALSE; | |
1497 | } else if (setepoch) { | |
9abb2685 | 1498 | fprintf(stderr, |
63cccae4 KZ |
1499 | _("Sorry, only the superuser can change the " |
1500 | "Hardware Clock epoch in the kernel.\n")); | |
1501 | permitted = FALSE; | |
1502 | } else | |
1503 | permitted = TRUE; | |
1504 | } | |
7eda085c | 1505 | |
63cccae4 | 1506 | if (!permitted) |
88058a71 | 1507 | hwclock_exit(EX_NOPERM); |
63cccae4 KZ |
1508 | |
1509 | if (getepoch || setepoch) { | |
1510 | manipulate_epoch(getepoch, setepoch, epoch_option, testing); | |
88058a71 | 1511 | hwclock_exit(0); |
63cccae4 KZ |
1512 | } |
1513 | ||
1514 | if (debug) | |
1515 | out_version(); | |
1516 | determine_clock_access_method(directisa); | |
1517 | if (!ur) { | |
22853e4a | 1518 | fprintf(stderr, |
63cccae4 KZ |
1519 | _("Cannot access the Hardware Clock via " |
1520 | "any known method.\n")); | |
1521 | if (!debug) | |
1522 | fprintf(stderr, | |
1523 | _("Use the --debug option to see the details " | |
1524 | "of our search for an access method.\n")); | |
88058a71 | 1525 | hwclock_exit(1); |
63cccae4 KZ |
1526 | } |
1527 | ||
88058a71 | 1528 | rc = manipulate_clock(show, adjust, noadjfile, set, set_time, |
63cccae4 KZ |
1529 | hctosys, systohc, startup_time, utc, |
1530 | local_opt, testing); | |
88058a71 KZ |
1531 | hwclock_exit(rc); |
1532 | return rc; /* Not reached */ | |
7eda085c KZ |
1533 | } |
1534 | ||
1535 | /* A single routine for greater uniformity */ | |
1536 | void | |
66ee8158 KZ |
1537 | outsyserr(char *msg, ...) { |
1538 | va_list args; | |
1539 | int errsv = errno; | |
9abb2685 | 1540 | |
66ee8158 KZ |
1541 | fprintf(stderr, "%s: ", progname); |
1542 | va_start(args, msg); | |
1543 | vfprintf(stderr, msg, args); | |
1544 | va_end(args); | |
1545 | fprintf(stderr, ", errno=%d: %s.\n", | |
1546 | errsv, strerror(errsv)); | |
7eda085c KZ |
1547 | } |
1548 | ||
88058a71 KZ |
1549 | |
1550 | #ifdef HAVE_LIBAUDIT | |
1551 | void | |
1552 | hwaudit_exit(int status) | |
1553 | { | |
1554 | if (hwaudit_on) { | |
1555 | audit_log_user_message(hwaudit_fd, AUDIT_USYS_CONFIG, | |
1556 | "changing system time", NULL, NULL, NULL, status ? 0 : 1); | |
1557 | close(hwaudit_fd); | |
1558 | } | |
1559 | exit(status); | |
1560 | } | |
1561 | #endif | |
1562 | ||
7eda085c KZ |
1563 | /**************************************************************************** |
1564 | ||
1565 | History of this program: | |
1566 | ||
9abb2685 | 1567 | 98.08.12 BJH Version 2.4 |
7eda085c KZ |
1568 | |
1569 | Don't use century byte from Hardware Clock. Add comments telling why. | |
1570 | ||
1571 | ||
1572 | 98.06.20 BJH Version 2.3. | |
1573 | ||
1574 | Make --hctosys set the kernel timezone from TZ environment variable | |
1575 | and/or /usr/lib/zoneinfo. From Klaus Ripke (klaus@ripke.com). | |
1576 | ||
9abb2685 | 1577 | 98.03.05 BJH. Version 2.2. |
7eda085c | 1578 | |
9abb2685 | 1579 | Add --getepoch and --setepoch. |
7eda085c KZ |
1580 | |
1581 | Fix some word length things so it works on Alpha. | |
1582 | ||
1583 | Make it work when /dev/rtc doesn't have the interrupt functions. | |
1584 | In this case, busywait for the top of a second instead of blocking and | |
1585 | waiting for the update complete interrupt. | |
1586 | ||
1587 | Fix a bunch of bugs too numerous to mention. | |
1588 | ||
1589 | 97.06.01: BJH. Version 2.1. Read and write the century byte (Byte | |
1590 | 50) of the ISA Hardware Clock when using direct ISA I/O. Problem | |
1591 | discovered by job (jei@iclnl.icl.nl). | |
9abb2685 | 1592 | |
7eda085c KZ |
1593 | Use the rtc clock access method in preference to the KDGHWCLK method. |
1594 | Problem discovered by Andreas Schwab <schwab@LS5.informatik.uni-dortmund.de>. | |
1595 | ||
1596 | November 1996: Version 2.0.1. Modifications by Nicolai Langfeldt | |
1597 | (janl@math.uio.no) to make it compile on linux 1.2 machines as well | |
1598 | as more recent versions of the kernel. Introduced the NO_CLOCK | |
1599 | access method and wrote feature test code to detect absense of rtc | |
1600 | headers. | |
1601 | ||
1602 | ||
1603 | ************************************************************************** | |
1604 | Maintenance notes | |
1605 | ||
1606 | To compile this, you must use GNU compiler optimization (-O option) | |
1607 | in order to make the "extern inline" functions from asm/io.h (inb(), | |
1608 | etc.) compile. If you don't optimize, which means the compiler | |
1609 | will generate no inline functions, the references to these functions | |
1610 | in this program will be compiled as external references. Since you | |
1611 | probably won't be linking with any functions by these names, you will | |
1612 | have unresolved external references when you link. | |
9abb2685 | 1613 | |
7eda085c | 1614 | The program is designed to run setuid superuser, since we need to be |
9abb2685 KZ |
1615 | able to do direct I/O. (More to the point: we need permission to |
1616 | execute the iopl() system call). (However, if you use one of the | |
7eda085c KZ |
1617 | methods other than direct ISA I/O to access the clock, no setuid is |
1618 | required). | |
9abb2685 | 1619 | |
7eda085c KZ |
1620 | Here's some info on how we must deal with the time that elapses while |
1621 | this program runs: There are two major delays as we run: | |
1622 | ||
1623 | 1) Waiting up to 1 second for a transition of the Hardware Clock so | |
1624 | we are synchronized to the Hardware Clock. | |
1625 | ||
1626 | 2) Running the "date" program to interpret the value of our --date | |
1627 | option. | |
1628 | ||
1629 | Reading the /etc/adjtime file is the next biggest source of delay and | |
1630 | uncertainty. | |
1631 | ||
1632 | The user wants to know what time it was at the moment he invoked us, | |
1633 | not some arbitrary time later. And in setting the clock, he is | |
1634 | giving us the time at the moment we are invoked, so if we set the | |
1635 | clock some time later, we have to add some time to that. | |
1636 | ||
1637 | So we check the system time as soon as we start up, then run "date" | |
1638 | and do file I/O if necessary, then wait to synchronize with a | |
1639 | Hardware Clock edge, then check the system time again to see how | |
9abb2685 | 1640 | much time we spent. We immediately read the clock then and (if |
7eda085c KZ |
1641 | appropriate) report that time, and additionally, the delay we measured. |
1642 | ||
1643 | If we're setting the clock to a time given by the user, we wait some | |
1644 | more so that the total delay is an integral number of seconds, then | |
1645 | set the Hardware Clock to the time the user requested plus that | |
1646 | integral number of seconds. N.B. The Hardware Clock can only be set | |
1647 | in integral seconds. | |
1648 | ||
1649 | If we're setting the clock to the system clock value, we wait for | |
1650 | the system clock to reach the top of a second, and then set the | |
1651 | Hardware Clock to the system clock's value. | |
1652 | ||
1653 | Here's an interesting point about setting the Hardware Clock: On my | |
1654 | machine, when you set it, it sets to that precise time. But one can | |
1655 | imagine another clock whose update oscillator marches on a steady one | |
1656 | second period, so updating the clock between any two oscillator ticks | |
1657 | is the same as updating it right at the earlier tick. To avoid any | |
1658 | complications that might cause, we set the clock as soon as possible | |
1659 | after an oscillator tick. | |
1660 | ||
9abb2685 | 1661 | |
7eda085c KZ |
1662 | About synchronizing to the Hardware Clock when reading the time: The |
1663 | precision of the Hardware Clock counters themselves is one second. | |
1664 | You can't read the counters and find out that is 12:01:02.5. But if | |
1665 | you consider the location in time of the counter's ticks as part of | |
1666 | its value, then its precision is as infinite as time is continuous! | |
1667 | What I'm saying is this: To find out the _exact_ time in the | |
1668 | hardware clock, we wait until the next clock tick (the next time the | |
1669 | second counter changes) and measure how long we had to wait. We | |
1670 | then read the value of the clock counters and subtract the wait time | |
1671 | and we know precisely what time it was when we set out to query the | |
1672 | time. | |
1673 | ||
1674 | hwclock uses this method, and considers the Hardware Clock to have | |
1675 | infinite precision. | |
1676 | ||
1677 | ||
1678 | Enhancements needed: | |
1679 | ||
1680 | - When waiting for whole second boundary in set_hardware_clock_exact, | |
1681 | fail if we miss the goal by more than .1 second, as could happen if | |
1682 | we get pre-empted (by the kernel dispatcher). | |
1683 | ||
9abb2685 | 1684 | ****************************************************************************/ |
7eda085c | 1685 |