]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * SPDX-License-Identifier: GPL-2.0-or-later | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * | |
10 | * Since 7a3000f7ba548cf7d74ac77cc63fe8de228a669e (v2.30) hwclock is linked | |
11 | * with parse_date.y from gnullib. This gnulib code is distributed with GPLv3. | |
12 | * Use --disable-hwclock-gplv3 to exclude this code. | |
13 | * | |
14 | * Copyright (C) 1992 Charles Hedrick, hedrick@cs.rutgers.edu | |
15 | * Rob Hooft <hooft@chem.ruu.nl> | |
16 | * Harald Koenig <koenig@nova.tat.physik.uni-tuebingen.de> | |
17 | * Alan Modra <alan@spri.levels.unisa.edu.au> | |
18 | * | |
19 | * Copyright (C) 2007-2023 Karel Zak <kzak@redhat.com> | |
20 | * | |
21 | * Major rewrite by Bryan Henderson <bryanh@giraffe-data.com>, 96.09.19. | |
22 | * The new program is called hwclock. New features: | |
23 | * | |
24 | * - You can set the hardware clock without also modifying the system | |
25 | * clock. | |
26 | * - You can read and set the clock with finer than 1 second precision. | |
27 | * - When you set the clock, hwclock automatically refigures the drift | |
28 | * rate, based on how far off the clock was before you set it. | |
29 | * | |
30 | * Reshuffled things, added sparc code, and re-added alpha stuff | |
31 | * by David Mosberger <davidm@azstarnet.com> | |
32 | * and Jay Estabrook <jestabro@amt.tay1.dec.com> | |
33 | * and Martin Ostermann <ost@comnets.rwth-aachen.de>, aeb@cwi.nl, 990212. | |
34 | * | |
35 | * Fix for Award 2094 bug, Dave Coffin (dcoffin@shore.net) 11/12/98 | |
36 | * Change of local time handling, Stefan Ring <e9725446@stud3.tuwien.ac.at> | |
37 | * Change of adjtime handling, James P. Rutledge <ao112@rgfn.epcc.edu>. | |
38 | * | |
39 | * | |
40 | */ | |
41 | /* | |
42 | * Explanation of `adjusting' (Rob Hooft): | |
43 | * | |
44 | * The problem with my machine is that its CMOS clock is 10 seconds | |
45 | * per day slow. With this version of clock.c, and my '/etc/rc.local' | |
46 | * reading '/etc/clock -au' instead of '/etc/clock -u -s', this error | |
47 | * is automatically corrected at every boot. | |
48 | * | |
49 | * To do this job, the program reads and writes the file '/etc/adjtime' | |
50 | * to determine the correction, and to save its data. In this file are | |
51 | * three numbers: | |
52 | * | |
53 | * 1) the correction in seconds per day. (So if your clock runs 5 | |
54 | * seconds per day fast, the first number should read -5.0) | |
55 | * 2) the number of seconds since 1/1/1970 the last time the program | |
56 | * was used | |
57 | * 3) the remaining part of a second which was leftover after the last | |
58 | * adjustment | |
59 | * | |
60 | * Installation and use of this program: | |
61 | * | |
62 | * a) create a file '/etc/adjtime' containing as the first and only | |
63 | * line: '0.0 0 0.0' | |
64 | * b) run 'clock -au' or 'clock -a', depending on whether your cmos is | |
65 | * in universal or local time. This updates the second number. | |
66 | * c) set your system time using the 'date' command. | |
67 | * d) update your cmos time using 'clock -wu' or 'clock -w' | |
68 | * e) replace the first number in /etc/adjtime by your correction. | |
69 | * f) put the command 'clock -au' or 'clock -a' in your '/etc/rc.local' | |
70 | */ | |
71 | ||
72 | #include <errno.h> | |
73 | #include <getopt.h> | |
74 | #include <limits.h> | |
75 | #include <math.h> | |
76 | #include <stdio.h> | |
77 | #include <stdlib.h> | |
78 | #include <string.h> | |
79 | #include <sys/stat.h> | |
80 | #include <sys/time.h> | |
81 | #ifdef HAVE_SYS_SYSCALL_H | |
82 | #include <sys/syscall.h> | |
83 | #endif | |
84 | #include <time.h> | |
85 | #include <unistd.h> | |
86 | #include <inttypes.h> | |
87 | ||
88 | #include "c.h" | |
89 | #include "closestream.h" | |
90 | #include "nls.h" | |
91 | #include "optutils.h" | |
92 | #include "pathnames.h" | |
93 | #include "hwclock.h" | |
94 | #include "timeutils.h" | |
95 | #include "env.h" | |
96 | #include "xalloc.h" | |
97 | #include "path.h" | |
98 | #include "strutils.h" | |
99 | ||
100 | #ifdef HAVE_LIBAUDIT | |
101 | #include <libaudit.h> | |
102 | static int hwaudit_fd = -1; | |
103 | #endif | |
104 | ||
105 | UL_DEBUG_DEFINE_MASK(hwclock); | |
106 | UL_DEBUG_DEFINE_MASKNAMES(hwclock) = UL_DEBUG_EMPTY_MASKNAMES; | |
107 | ||
108 | /* The struct that holds our hardware access routines */ | |
109 | static const struct clock_ops *ur; | |
110 | ||
111 | /* Maximal clock adjustment in seconds per day. | |
112 | (adjtime() glibc call has 2145 seconds limit on i386, so it is good enough for us as well, | |
113 | 43219 is a maximal safe value preventing exact_adjustment overflow.) */ | |
114 | #define MAX_DRIFT 2145.0 | |
115 | ||
116 | struct adjtime { | |
117 | /* | |
118 | * This is information we keep in the adjtime file that tells us how | |
119 | * to do drift corrections. Elements are all straight from the | |
120 | * adjtime file, so see documentation of that file for details. | |
121 | * Exception is <dirty>, which is an indication that what's in this | |
122 | * structure is not what's in the disk file (because it has been | |
123 | * updated since read from the disk file). | |
124 | */ | |
125 | int dirty; | |
126 | /* line 1 */ | |
127 | double drift_factor; | |
128 | time_t last_adj_time; | |
129 | double not_adjusted; | |
130 | /* line 2 */ | |
131 | time_t last_calib_time; | |
132 | /* | |
133 | * The most recent time that we set the clock from an external | |
134 | * authority (as opposed to just doing a drift adjustment) | |
135 | */ | |
136 | /* line 3 */ | |
137 | enum a_local_utc { UTC = 0, LOCAL, UNKNOWN } local_utc; | |
138 | /* | |
139 | * To which time zone, local or UTC, we most recently set the | |
140 | * hardware clock. | |
141 | */ | |
142 | }; | |
143 | ||
144 | static void hwclock_init_debug(const char *str) | |
145 | { | |
146 | __UL_INIT_DEBUG_FROM_STRING(hwclock, HWCLOCK_DEBUG_, 0, str); | |
147 | ||
148 | DBG(INIT, ul_debug("hwclock debug mask: 0x%04x", hwclock_debug_mask)); | |
149 | DBG(INIT, ul_debug("hwclock version: %s", PACKAGE_STRING)); | |
150 | } | |
151 | ||
152 | /* FOR TESTING ONLY: inject random delays of up to 1000ms */ | |
153 | static void up_to_1000ms_sleep(void) | |
154 | { | |
155 | int usec = random() % 1000000; | |
156 | ||
157 | DBG(RANDOM_SLEEP, ul_debug("sleeping ~%d usec", usec)); | |
158 | xusleep(usec); | |
159 | } | |
160 | ||
161 | /* | |
162 | * time_t to timeval conversion. | |
163 | */ | |
164 | static struct timeval t2tv(time_t timet) | |
165 | { | |
166 | struct timeval rettimeval; | |
167 | ||
168 | rettimeval.tv_sec = timet; | |
169 | rettimeval.tv_usec = 0; | |
170 | return rettimeval; | |
171 | } | |
172 | ||
173 | /* | |
174 | * The difference in seconds between two times in "timeval" format. | |
175 | */ | |
176 | double time_diff(struct timeval subtrahend, struct timeval subtractor) | |
177 | { | |
178 | return (subtrahend.tv_sec - subtractor.tv_sec) | |
179 | + (subtrahend.tv_usec - subtractor.tv_usec) / 1E6; | |
180 | } | |
181 | ||
182 | /* | |
183 | * The time, in "timeval" format, which is <increment> seconds after the | |
184 | * time <addend>. Of course, <increment> may be negative. | |
185 | */ | |
186 | static struct timeval time_inc(struct timeval addend, double increment) | |
187 | { | |
188 | struct timeval newtime; | |
189 | ||
190 | newtime.tv_sec = addend.tv_sec + (time_t)increment; | |
191 | newtime.tv_usec = addend.tv_usec + (increment - (time_t)increment) * 1E6; | |
192 | ||
193 | /* | |
194 | * Now adjust it so that the microsecond value is between 0 and 1 | |
195 | * million. | |
196 | */ | |
197 | if (newtime.tv_usec < 0) { | |
198 | newtime.tv_usec += 1E6; | |
199 | newtime.tv_sec -= 1; | |
200 | } else if (newtime.tv_usec >= 1E6) { | |
201 | newtime.tv_usec -= 1E6; | |
202 | newtime.tv_sec += 1; | |
203 | } | |
204 | return newtime; | |
205 | } | |
206 | ||
207 | static int | |
208 | hw_clock_is_utc(const struct hwclock_control *ctl, | |
209 | const struct adjtime *adjtime) | |
210 | { | |
211 | int ret; | |
212 | ||
213 | if (ctl->utc) | |
214 | ret = 1; /* --utc explicitly given on command line */ | |
215 | else if (ctl->local_opt) | |
216 | ret = 0; /* --localtime explicitly given */ | |
217 | else | |
218 | /* get info from adjtime file - default is UTC */ | |
219 | ret = (adjtime->local_utc != LOCAL); | |
220 | ||
221 | if (ctl->verbose) | |
222 | printf(_("Assuming hardware clock is kept in %s time.\n"), | |
223 | ret ? _("UTC") : _("local")); | |
224 | return ret; | |
225 | } | |
226 | ||
227 | /* | |
228 | * Read the adjustment parameters out of the /etc/adjtime file. | |
229 | * | |
230 | * Return them as the adjtime structure <*adjtime_p>. Its defaults are | |
231 | * initialized in main(). | |
232 | */ | |
233 | static int read_adjtime(const struct hwclock_control *ctl, | |
234 | struct adjtime *adjtime_p) | |
235 | { | |
236 | FILE *adjfile; | |
237 | char line1[81]; /* String: first line of adjtime file */ | |
238 | char line2[81]; /* String: second line of adjtime file */ | |
239 | char line3[81]; /* String: third line of adjtime file */ | |
240 | int64_t last_adj_time; | |
241 | int64_t last_calib_time; | |
242 | ||
243 | if (access(ctl->adj_file_name, R_OK) != 0) | |
244 | return EXIT_SUCCESS; | |
245 | ||
246 | adjfile = fopen(ctl->adj_file_name, "r"); /* open file for reading */ | |
247 | if (adjfile == NULL) { | |
248 | warn(_("cannot open %s"), ctl->adj_file_name); | |
249 | return EXIT_FAILURE; | |
250 | } | |
251 | ||
252 | if (!fgets(line1, sizeof(line1), adjfile)) | |
253 | line1[0] = '\0'; /* In case fgets fails */ | |
254 | if (!fgets(line2, sizeof(line2), adjfile)) | |
255 | line2[0] = '\0'; /* In case fgets fails */ | |
256 | if (!fgets(line3, sizeof(line3), adjfile)) | |
257 | line3[0] = '\0'; /* In case fgets fails */ | |
258 | ||
259 | fclose(adjfile); | |
260 | ||
261 | if (sscanf(line1, "%lf %"SCNd64" %lf", | |
262 | &adjtime_p->drift_factor, | |
263 | &last_adj_time, | |
264 | &adjtime_p->not_adjusted) != 3) | |
265 | warnx(_("Warning: unrecognized line in adjtime file: %s"), line1); | |
266 | ||
267 | if (sscanf(line2, "%"SCNd64, &last_calib_time) != 1) | |
268 | warnx(_("Warning: unrecognized line in adjtime file: %s"), line2); | |
269 | ||
270 | adjtime_p->last_adj_time = (time_t)last_adj_time; | |
271 | adjtime_p->last_calib_time = (time_t)last_calib_time; | |
272 | ||
273 | if (!strcmp(line3, "UTC\n")) { | |
274 | adjtime_p->local_utc = UTC; | |
275 | } else if (!strcmp(line3, "LOCAL\n")) { | |
276 | adjtime_p->local_utc = LOCAL; | |
277 | } else { | |
278 | adjtime_p->local_utc = UNKNOWN; | |
279 | if (line3[0]) { | |
280 | warnx(_("Warning: unrecognized third line in adjtime file\n" | |
281 | "(Expected: `UTC' or `LOCAL' or nothing.)")); | |
282 | } | |
283 | } | |
284 | ||
285 | if (ctl->verbose) { | |
286 | printf(_("Last drift adjustment done at %"PRId64" seconds after 1969\n"), | |
287 | (int64_t)adjtime_p->last_adj_time); | |
288 | printf(_("Last calibration done at %"PRId64" seconds after 1969\n"), | |
289 | (int64_t)adjtime_p->last_calib_time); | |
290 | printf(_("Hardware clock is on %s time\n"), | |
291 | (adjtime_p->local_utc == | |
292 | LOCAL) ? _("local") : (adjtime_p->local_utc == | |
293 | UTC) ? _("UTC") : _("unknown")); | |
294 | } | |
295 | ||
296 | return EXIT_SUCCESS; | |
297 | } | |
298 | ||
299 | /* | |
300 | * Wait until the falling edge of the Hardware Clock's update flag so that | |
301 | * any time that is read from the clock immediately after we return will be | |
302 | * exact. | |
303 | * | |
304 | * The clock only has 1 second precision, so it gives the exact time only | |
305 | * once per second, right on the falling edge of the update flag. | |
306 | * | |
307 | * We wait (up to one second) either blocked waiting for an rtc device or in | |
308 | * a CPU spin loop. The former is probably not very accurate. | |
309 | * | |
310 | * Return 0 if it worked, nonzero if it didn't. | |
311 | */ | |
312 | static int synchronize_to_clock_tick(const struct hwclock_control *ctl) | |
313 | { | |
314 | int rc; | |
315 | ||
316 | if (ctl->verbose) | |
317 | printf(_("Waiting for clock tick...\n")); | |
318 | ||
319 | rc = ur->synchronize_to_clock_tick(ctl); | |
320 | ||
321 | if (ctl->verbose) { | |
322 | if (rc) | |
323 | printf(_("...synchronization failed\n")); | |
324 | else | |
325 | printf(_("...got clock tick\n")); | |
326 | } | |
327 | ||
328 | return rc; | |
329 | } | |
330 | ||
331 | /* | |
332 | * Convert a time in broken down format (hours, minutes, etc.) into standard | |
333 | * unix time (seconds into epoch). Return it as *systime_p. | |
334 | * | |
335 | * The broken down time is argument <tm>. This broken down time is either | |
336 | * in local time zone or UTC, depending on value of logical argument | |
337 | * "universal". True means it is in UTC. | |
338 | * | |
339 | * If the argument contains values that do not constitute a valid time, and | |
340 | * mktime() recognizes this, return *valid_p == false and *systime_p | |
341 | * undefined. However, mktime() sometimes goes ahead and computes a | |
342 | * fictional time "as if" the input values were valid, e.g. if they indicate | |
343 | * the 31st day of April, mktime() may compute the time of May 1. In such a | |
344 | * case, we return the same fictional value mktime() does as *systime_p and | |
345 | * return *valid_p == true. | |
346 | */ | |
347 | static int | |
348 | mktime_tz(const struct hwclock_control *ctl, struct tm tm, | |
349 | time_t *systime_p) | |
350 | { | |
351 | int valid; | |
352 | ||
353 | if (ctl->universal) | |
354 | *systime_p = timegm(&tm); | |
355 | else | |
356 | *systime_p = mktime(&tm); | |
357 | if (*systime_p == -1) { | |
358 | /* | |
359 | * This apparently (not specified in mktime() documentation) | |
360 | * means the 'tm' structure does not contain valid values | |
361 | * (however, not containing valid values does _not_ imply | |
362 | * mktime() returns -1). | |
363 | */ | |
364 | valid = 0; | |
365 | if (ctl->verbose) | |
366 | printf(_("Invalid values in hardware clock: " | |
367 | "%4d/%.2d/%.2d %.2d:%.2d:%.2d\n"), | |
368 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, | |
369 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
370 | } else { | |
371 | valid = 1; | |
372 | if (ctl->verbose) | |
373 | printf(_("Hw clock time : %4d/%.2d/%.2d %.2d:%.2d:%.2d = " | |
374 | "%"PRId64" seconds since 1969\n"), tm.tm_year + 1900, | |
375 | tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, | |
376 | tm.tm_sec, (int64_t)*systime_p); | |
377 | } | |
378 | return valid; | |
379 | } | |
380 | ||
381 | /* | |
382 | * Read the hardware clock and return the current time via <tm> argument. | |
383 | * | |
384 | * Use the method indicated by <method> argument to access the hardware | |
385 | * clock. | |
386 | */ | |
387 | static int | |
388 | read_hardware_clock(const struct hwclock_control *ctl, | |
389 | int *valid_p, time_t *systime_p) | |
390 | { | |
391 | struct tm tm = { 0 }; | |
392 | int err; | |
393 | ||
394 | err = ur->read_hardware_clock(ctl, &tm); | |
395 | if (err) | |
396 | return err; | |
397 | ||
398 | if (ctl->verbose) | |
399 | printf(_("Time read from Hardware Clock: %4d/%.2d/%.2d %02d:%02d:%02d\n"), | |
400 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, | |
401 | tm.tm_min, tm.tm_sec); | |
402 | *valid_p = mktime_tz(ctl, tm, systime_p); | |
403 | ||
404 | return 0; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Set the Hardware Clock to the time <newtime>, in local time zone or UTC, | |
409 | * according to <universal>. | |
410 | */ | |
411 | static void | |
412 | set_hardware_clock(const struct hwclock_control *ctl, const time_t newtime) | |
413 | { | |
414 | struct tm new_broken_time = { 0 }; | |
415 | /* | |
416 | * Time to which we will set Hardware Clock, in broken down format, | |
417 | * in the time zone of caller's choice | |
418 | */ | |
419 | ||
420 | if (ctl->universal) | |
421 | gmtime_r(&newtime, &new_broken_time); | |
422 | else | |
423 | localtime_r(&newtime, &new_broken_time); | |
424 | ||
425 | if (ctl->verbose) | |
426 | printf(_("Setting Hardware Clock to %.2d:%.2d:%.2d " | |
427 | "= %"PRId64" seconds since 1969\n"), | |
428 | new_broken_time.tm_hour, new_broken_time.tm_min, | |
429 | new_broken_time.tm_sec, (int64_t)newtime); | |
430 | ||
431 | if (!ctl->testing) | |
432 | ur->set_hardware_clock(ctl, &new_broken_time); | |
433 | } | |
434 | ||
435 | static double | |
436 | get_hardware_delay(const struct hwclock_control *ctl) | |
437 | { | |
438 | const char *devpath, *rtcname; | |
439 | char name[128 + 1]; | |
440 | struct path_cxt *pc; | |
441 | int rc; | |
442 | ||
443 | devpath = ur->get_device_path(); | |
444 | if (!devpath) | |
445 | goto unknown; | |
446 | ||
447 | rtcname = strrchr(devpath, '/'); | |
448 | if (!rtcname || !*(rtcname + 1)) | |
449 | goto unknown; | |
450 | rtcname++; | |
451 | ||
452 | pc = ul_new_path("/sys/class/rtc/%s", rtcname); | |
453 | if (!pc) | |
454 | goto unknown; | |
455 | rc = ul_path_scanf(pc, "name", "%128[^\n ]", name); | |
456 | ul_unref_path(pc); | |
457 | ||
458 | if (rc != 1 || !*name) | |
459 | goto unknown; | |
460 | ||
461 | if (ctl->verbose) | |
462 | printf(_("RTC type: '%s'\n"), name); | |
463 | ||
464 | /* MC146818A-compatible (x86) */ | |
465 | if (strcmp(name, "rtc_cmos") == 0) | |
466 | return 0.5; | |
467 | ||
468 | /* Another HW */ | |
469 | return 0; | |
470 | unknown: | |
471 | /* Let's be backwardly compatible */ | |
472 | return 0.5; | |
473 | } | |
474 | ||
475 | ||
476 | /* | |
477 | * Set the Hardware Clock to the time "sethwtime", in local time zone or | |
478 | * UTC, according to "universal". | |
479 | * | |
480 | * Wait for a fraction of a second so that "sethwtime" is the value of the | |
481 | * Hardware Clock as of system time "refsystime", which is in the past. For | |
482 | * example, if "sethwtime" is 14:03:05 and "refsystime" is 12:10:04.5 and | |
483 | * the current system time is 12:10:06.0: Wait .5 seconds (to make exactly 2 | |
484 | * seconds since "refsystime") and then set the Hardware Clock to 14:03:07, | |
485 | * thus getting a precise and retroactive setting of the clock. The .5 delay is | |
486 | * default on x86, see --delay and get_hardware_delay(). | |
487 | * | |
488 | * (Don't be confused by the fact that the system clock and the Hardware | |
489 | * Clock differ by two hours in the above example. That's just to remind you | |
490 | * that there are two independent time scales here). | |
491 | * | |
492 | * This function ought to be able to accept set times as fractional times. | |
493 | * Idea for future enhancement. | |
494 | */ | |
495 | static void | |
496 | set_hardware_clock_exact(const struct hwclock_control *ctl, | |
497 | const time_t sethwtime, | |
498 | const struct timeval refsystime) | |
499 | { | |
500 | /* | |
501 | * The Hardware Clock can only be set to any integer time plus one | |
502 | * half second. The integer time is required because there is no | |
503 | * interface to set or get a fractional second. The additional half | |
504 | * second is because the Hardware Clock updates to the following | |
505 | * second precisely 500 ms (not 1 second!) after you release the | |
506 | * divider reset (after setting the new time) - see description of | |
507 | * DV2, DV1, DV0 in Register A in the MC146818A data sheet (and note | |
508 | * that although that document doesn't say so, real-world code seems | |
509 | * to expect that the SET bit in Register B functions the same way). | |
510 | * That means that, e.g., when you set the clock to 1:02:03, it | |
511 | * effectively really sets it to 1:02:03.5, because it will update to | |
512 | * 1:02:04 only half a second later. Our caller passes the desired | |
513 | * integer Hardware Clock time in sethwtime, and the corresponding | |
514 | * system time (which may have a fractional part, and which may or may | |
515 | * not be the same!) in refsystime. In an ideal situation, we would | |
516 | * then apply sethwtime to the Hardware Clock at refsystime+500ms, so | |
517 | * that when the Hardware Clock ticks forward to sethwtime+1s half a | |
518 | * second later at refsystime+1000ms, everything is in sync. So we | |
519 | * spin, waiting for gettimeofday() to return a time at or after that | |
520 | * time (refsystime+500ms) up to a tolerance value, initially 1ms. If | |
521 | * we miss that time due to being preempted for some other process, | |
522 | * then we increase the margin a little bit (initially 1ms, doubling | |
523 | * each time), add 1 second (or more, if needed to get a time that is | |
524 | * in the future) to both the time for which we are waiting and the | |
525 | * time that we will apply to the Hardware Clock, and start waiting | |
526 | * again. | |
527 | * | |
528 | * For example, the caller requests that we set the Hardware Clock to | |
529 | * 1:02:03, with reference time (current system time) = 6:07:08.250. | |
530 | * We want the Hardware Clock to update to 1:02:04 at 6:07:09.250 on | |
531 | * the system clock, and the first such update will occur 0.500 | |
532 | * seconds after we write to the Hardware Clock, so we spin until the | |
533 | * system clock reads 6:07:08.750. If we get there, great, but let's | |
534 | * imagine the system is so heavily loaded that our process is | |
535 | * preempted and by the time we get to run again, the system clock | |
536 | * reads 6:07:11.990. We now want to wait until the next xx:xx:xx.750 | |
537 | * time, which is 6:07:12.750 (4.5 seconds after the reference time), | |
538 | * at which point we will set the Hardware Clock to 1:02:07 (4 seconds | |
539 | * after the originally requested time). If we do that successfully, | |
540 | * then at 6:07:13.250 (5 seconds after the reference time), the | |
541 | * Hardware Clock will update to 1:02:08 (5 seconds after the | |
542 | * originally requested time), and all is well thereafter. | |
543 | */ | |
544 | ||
545 | time_t newhwtime = sethwtime; | |
546 | double target_time_tolerance_secs = 0.001; /* initial value */ | |
547 | double tolerance_incr_secs = 0.001; /* initial value */ | |
548 | double delay; | |
549 | struct timeval rtc_set_delay_tv; | |
550 | ||
551 | struct timeval targetsystime; | |
552 | struct timeval nowsystime; | |
553 | struct timeval prevsystime = refsystime; | |
554 | double deltavstarget; | |
555 | ||
556 | if (ctl->rtc_delay != -1.0) /* --delay specified */ | |
557 | delay = ctl->rtc_delay; | |
558 | else | |
559 | delay = get_hardware_delay(ctl); | |
560 | ||
561 | if (ctl->verbose) | |
562 | printf(_("Using delay: %.6f seconds\n"), delay); | |
563 | ||
564 | rtc_set_delay_tv.tv_sec = 0; | |
565 | rtc_set_delay_tv.tv_usec = delay * 1E6; | |
566 | ||
567 | timeradd(&refsystime, &rtc_set_delay_tv, &targetsystime); | |
568 | ||
569 | while (1) { | |
570 | double ticksize; | |
571 | ||
572 | ON_DBG(RANDOM_SLEEP, up_to_1000ms_sleep()); | |
573 | ||
574 | gettimeofday(&nowsystime, NULL); | |
575 | deltavstarget = time_diff(nowsystime, targetsystime); | |
576 | ticksize = time_diff(nowsystime, prevsystime); | |
577 | prevsystime = nowsystime; | |
578 | ||
579 | if (ticksize < 0) { | |
580 | if (ctl->verbose) | |
581 | printf(_("time jumped backward %.6f seconds " | |
582 | "to %"PRId64".%06"PRId64" - retargeting\n"), | |
583 | ticksize, (int64_t)nowsystime.tv_sec, | |
584 | (int64_t)nowsystime.tv_usec); | |
585 | /* The retarget is handled at the end of the loop. */ | |
586 | } else if (deltavstarget < 0) { | |
587 | /* deltavstarget < 0 if current time < target time */ | |
588 | DBG(DELTA_VS_TARGET, | |
589 | ul_debug("%"PRId64".%06"PRId64" < %"PRId64".%06"PRId64" (%.6f)", | |
590 | (int64_t)nowsystime.tv_sec, (int64_t)nowsystime.tv_usec, | |
591 | (int64_t)targetsystime.tv_sec, | |
592 | (int64_t)targetsystime.tv_usec, deltavstarget)); | |
593 | continue; /* not there yet - keep spinning */ | |
594 | } else if (deltavstarget <= target_time_tolerance_secs) { | |
595 | /* Close enough to the target time; done waiting. */ | |
596 | break; | |
597 | } else /* (deltavstarget > target_time_tolerance_secs) */ { | |
598 | /* | |
599 | * We missed our window. Increase the tolerance and | |
600 | * aim for the next opportunity. | |
601 | */ | |
602 | if (ctl->verbose) | |
603 | printf(_("missed it - %"PRId64".%06"PRId64" is too far " | |
604 | "past %"PRId64".%06"PRId64" (%.6f > %.6f)\n"), | |
605 | (int64_t)nowsystime.tv_sec, | |
606 | (int64_t)nowsystime.tv_usec, | |
607 | (int64_t)targetsystime.tv_sec, | |
608 | (int64_t)targetsystime.tv_usec, | |
609 | deltavstarget, | |
610 | target_time_tolerance_secs); | |
611 | target_time_tolerance_secs += tolerance_incr_secs; | |
612 | tolerance_incr_secs *= 2; | |
613 | } | |
614 | ||
615 | /* | |
616 | * Aim for the same offset (tv_usec) within the second in | |
617 | * either the current second (if that offset hasn't arrived | |
618 | * yet), or the next second. | |
619 | */ | |
620 | if (nowsystime.tv_usec < targetsystime.tv_usec) | |
621 | targetsystime.tv_sec = nowsystime.tv_sec; | |
622 | else | |
623 | targetsystime.tv_sec = nowsystime.tv_sec + 1; | |
624 | } | |
625 | ||
626 | newhwtime = sethwtime | |
627 | + round(time_diff(nowsystime, refsystime) | |
628 | - delay /* don't count this */); | |
629 | if (ctl->verbose) | |
630 | printf(_("%"PRId64".%06"PRId64" is close enough to %"PRId64".%06"PRId64" (%.6f < %.6f)\n" | |
631 | "Set RTC to %"PRId64" (%"PRId64" + %d; refsystime = %"PRId64".%06"PRId64")\n"), | |
632 | (int64_t)nowsystime.tv_sec, (int64_t)nowsystime.tv_usec, | |
633 | (int64_t)targetsystime.tv_sec, (int64_t)targetsystime.tv_usec, | |
634 | deltavstarget, target_time_tolerance_secs, | |
635 | (int64_t)newhwtime, (int64_t)sethwtime, | |
636 | (int)((int64_t)newhwtime - (int64_t)sethwtime), | |
637 | (int64_t)refsystime.tv_sec, (int64_t)refsystime.tv_usec); | |
638 | ||
639 | set_hardware_clock(ctl, newhwtime); | |
640 | } | |
641 | ||
642 | static int | |
643 | display_time(struct timeval hwctime) | |
644 | { | |
645 | char buf[ISO_BUFSIZ]; | |
646 | ||
647 | if (strtimeval_iso(&hwctime, ISO_TIMESTAMP_DOT, buf, sizeof(buf))) | |
648 | return EXIT_FAILURE; | |
649 | ||
650 | printf("%s\n", buf); | |
651 | return EXIT_SUCCESS; | |
652 | } | |
653 | ||
654 | /* | |
655 | * Adjusts System time, sets the kernel's timezone and RTC timescale. | |
656 | * | |
657 | * The kernel warp_clock function adjusts the System time according to the | |
658 | * tz.tz_minuteswest argument and sets PCIL (see below). At boot settimeofday(2) | |
659 | * has one-shot access to this function as shown in the table below. | |
660 | * | |
661 | * +-------------------------------------------------------------------------+ | |
662 | * | settimeofday(tv, tz) | | |
663 | * |-------------------------------------------------------------------------| | |
664 | * | Arguments | System Time | TZ | PCIL | | warp_clock | | |
665 | * | tv | tz | set | warped | set | set | firsttime | locked | | |
666 | * |---------|---------|---------------|-----|------|-----------|------------| | |
667 | * | pointer | NULL | yes | no | no | no | 1 | no | | |
668 | * | NULL | ptr2utc | no | no | yes | no | 0 | yes | | |
669 | * | NULL | pointer | no | yes | yes | yes | 0 | yes | | |
670 | * +-------------------------------------------------------------------------+ | |
671 | * ptr2utc: tz.tz_minuteswest is zero (UTC). | |
672 | * PCIL: persistent_clock_is_local, sets the "11 minute mode" timescale. | |
673 | * firsttime: locks the warp_clock function (initialized to 1 at boot). | |
674 | * | |
675 | * +---------------------------------------------------------------------------+ | |
676 | * | op | RTC scale | settimeofday calls | | |
677 | * |---------|-----------|-----------------------------------------------------| | |
678 | * | systz | Local | 1) warps system time*, sets PCIL* and kernel tz | | |
679 | * | systz | UTC | 1st) locks warp_clock* 2nd) sets kernel tz | | |
680 | * | hctosys | Local | 1st) sets PCIL* & kernel tz 2nd) sets system time | | |
681 | * | hctosys | UTC | 1st) locks warp* 2nd) sets tz 3rd) sets system time | | |
682 | * +---------------------------------------------------------------------------+ | |
683 | * * only on first call after boot | |
684 | * | |
685 | * POSIX 2008 marked TZ in settimeofday() as deprecated. Unfortunately, | |
686 | * different C libraries react to this deprecation in a different way. Since | |
687 | * glibc v2.31 settimeofday() will fail if both args are not NULL, Musl-C | |
688 | * ignores TZ at all, etc. We use __set_time() and __set_timezone() to hide | |
689 | * these portability issues and to keep code readable. | |
690 | */ | |
691 | #define __set_time(_tv) settimeofday(_tv, NULL) | |
692 | ||
693 | #ifndef SYS_settimeofday | |
694 | # ifdef __NR_settimeofday | |
695 | # define SYS_settimeofday __NR_settimeofday | |
696 | # elif defined(__NR_settimeofday_time32) | |
697 | # define SYS_settimeofday __NR_settimeofday_time32 | |
698 | # endif | |
699 | #endif | |
700 | ||
701 | static inline int __set_timezone(const struct timezone *tz) | |
702 | { | |
703 | #ifdef SYS_settimeofday | |
704 | errno = 0; | |
705 | return syscall(SYS_settimeofday, NULL, tz); | |
706 | #else | |
707 | return settimeofday(NULL, tz); | |
708 | #endif | |
709 | } | |
710 | ||
711 | static int | |
712 | set_system_clock(const struct hwclock_control *ctl, | |
713 | const struct timeval newtime) | |
714 | { | |
715 | struct tm broken = { 0 }; | |
716 | int minuteswest; | |
717 | int rc = 0; | |
718 | ||
719 | localtime_r(&newtime.tv_sec, &broken); | |
720 | minuteswest = -get_gmtoff(&broken) / 60; | |
721 | ||
722 | if (ctl->verbose) { | |
723 | if (ctl->universal) { | |
724 | puts(_("Calling settimeofday(NULL, 0) " | |
725 | "to lock the warp_clock function.")); | |
726 | if (!( ctl->universal && !minuteswest )) | |
727 | printf(_("Calling settimeofday(NULL, %d) " | |
728 | "to set the kernel timezone.\n"), | |
729 | minuteswest); | |
730 | } else | |
731 | printf(_("Calling settimeofday(NULL, %d) to warp " | |
732 | "System time, set PCIL and the kernel tz.\n"), | |
733 | minuteswest); | |
734 | ||
735 | if (ctl->hctosys) | |
736 | printf(_("Calling settimeofday(%"PRId64".%06"PRId64", NULL) " | |
737 | "to set the System time.\n"), | |
738 | (int64_t)newtime.tv_sec, (int64_t)newtime.tv_usec); | |
739 | } | |
740 | ||
741 | if (!ctl->testing) { | |
742 | const struct timezone tz_utc = { 0 }; | |
743 | const struct timezone tz = { minuteswest }; | |
744 | ||
745 | /* If UTC RTC: lock warp_clock and PCIL */ | |
746 | if (ctl->universal) | |
747 | rc = __set_timezone(&tz_utc); | |
748 | ||
749 | /* Set kernel tz; if localtime RTC: warp_clock and set PCIL */ | |
750 | if (!rc && !( ctl->universal && !minuteswest )) | |
751 | rc = __set_timezone(&tz); | |
752 | ||
753 | /* Set the System Clock */ | |
754 | if ((!rc || errno == ENOSYS) && ctl->hctosys) | |
755 | rc = __set_time(&newtime); | |
756 | ||
757 | if (rc) { | |
758 | warn(_("settimeofday() failed")); | |
759 | return EXIT_FAILURE; | |
760 | } | |
761 | } | |
762 | return EXIT_SUCCESS; | |
763 | } | |
764 | ||
765 | /* | |
766 | * Refresh the last calibrated and last adjusted timestamps in <*adjtime_p> | |
767 | * to facilitate future drift calculations based on this set point. | |
768 | * | |
769 | * With the --update-drift option: | |
770 | * Update the drift factor in <*adjtime_p> based on the fact that the | |
771 | * Hardware Clock was just calibrated to <nowtime> and before that was | |
772 | * set to the <hclocktime> time scale. | |
773 | */ | |
774 | static void | |
775 | adjust_drift_factor(const struct hwclock_control *ctl, | |
776 | struct adjtime *adjtime_p, | |
777 | const struct timeval nowtime, | |
778 | const struct timeval hclocktime) | |
779 | { | |
780 | if (!ctl->update) { | |
781 | if (ctl->verbose) | |
782 | printf(_("Not adjusting drift factor because the " | |
783 | "--update-drift option was not used.\n")); | |
784 | } else if (adjtime_p->last_calib_time == 0) { | |
785 | if (ctl->verbose) | |
786 | printf(_("Not adjusting drift factor because last " | |
787 | "calibration time is zero,\n" | |
788 | "so history is bad and calibration startover " | |
789 | "is necessary.\n")); | |
790 | } else if ((hclocktime.tv_sec - adjtime_p->last_calib_time) < 4 * 60 * 60) { | |
791 | if (ctl->verbose) | |
792 | printf(_("Not adjusting drift factor because it has " | |
793 | "been less than four hours since the last " | |
794 | "calibration.\n")); | |
795 | } else { | |
796 | /* | |
797 | * At adjustment time we drift correct the hardware clock | |
798 | * according to the contents of the adjtime file and refresh | |
799 | * its last adjusted timestamp. | |
800 | * | |
801 | * At calibration time we set the Hardware Clock and refresh | |
802 | * both timestamps in <*adjtime_p>. | |
803 | * | |
804 | * Here, with the --update-drift option, we also update the | |
805 | * drift factor in <*adjtime_p>. | |
806 | * | |
807 | * Let us do computation in doubles. (Floats almost suffice, | |
808 | * but 195 days + 1 second equals 195 days in floats.) | |
809 | */ | |
810 | const double sec_per_day = 24.0 * 60.0 * 60.0; | |
811 | double factor_adjust; | |
812 | double drift_factor; | |
813 | struct timeval last_calib; | |
814 | ||
815 | last_calib = t2tv(adjtime_p->last_calib_time); | |
816 | /* | |
817 | * Correction to apply to the current drift factor. | |
818 | * | |
819 | * Simplified: uncorrected_drift / days_since_calibration. | |
820 | * | |
821 | * hclocktime is fully corrected with the current drift factor. | |
822 | * Its difference from nowtime is the missed drift correction. | |
823 | */ | |
824 | factor_adjust = time_diff(nowtime, hclocktime) / | |
825 | (time_diff(nowtime, last_calib) / sec_per_day); | |
826 | ||
827 | drift_factor = adjtime_p->drift_factor + factor_adjust; | |
828 | if (fabs(drift_factor) > MAX_DRIFT) { | |
829 | if (ctl->verbose) | |
830 | printf(_("Clock drift factor was calculated as " | |
831 | "%f seconds/day.\n" | |
832 | "It is far too much. Resetting to zero.\n"), | |
833 | drift_factor); | |
834 | drift_factor = 0; | |
835 | } else { | |
836 | if (ctl->verbose) | |
837 | printf(_("Clock drifted %f seconds in the past " | |
838 | "%f seconds\nin spite of a drift factor of " | |
839 | "%f seconds/day.\n" | |
840 | "Adjusting drift factor by %f seconds/day\n"), | |
841 | time_diff(nowtime, hclocktime), | |
842 | time_diff(nowtime, last_calib), | |
843 | adjtime_p->drift_factor, factor_adjust); | |
844 | } | |
845 | ||
846 | adjtime_p->drift_factor = drift_factor; | |
847 | } | |
848 | adjtime_p->last_calib_time = nowtime.tv_sec; | |
849 | ||
850 | adjtime_p->last_adj_time = nowtime.tv_sec; | |
851 | ||
852 | adjtime_p->not_adjusted = 0; | |
853 | ||
854 | adjtime_p->dirty = 1; | |
855 | } | |
856 | ||
857 | /* | |
858 | * Calculate the drift correction currently needed for the | |
859 | * Hardware Clock based on the last time it was adjusted, | |
860 | * and the current drift factor, as stored in the adjtime file. | |
861 | * | |
862 | * The total drift adjustment needed is stored at tdrift_p. | |
863 | * | |
864 | */ | |
865 | static void | |
866 | calculate_adjustment(const struct hwclock_control *ctl, | |
867 | const double factor, | |
868 | const time_t last_time, | |
869 | const double not_adjusted, | |
870 | const time_t systime, struct timeval *tdrift_p) | |
871 | { | |
872 | double exact_adjustment; | |
873 | ||
874 | exact_adjustment = | |
875 | ((double)(systime - last_time)) * factor / (24 * 60 * 60) | |
876 | + not_adjusted; | |
877 | tdrift_p->tv_sec = (time_t) floor(exact_adjustment); | |
878 | tdrift_p->tv_usec = (exact_adjustment - | |
879 | (double)tdrift_p->tv_sec) * 1E6; | |
880 | if (ctl->verbose) { | |
881 | printf(P_("Time since last adjustment is %"PRId64" second\n", | |
882 | "Time since last adjustment is %"PRId64" seconds\n", | |
883 | ((int64_t)systime - (int64_t)last_time)), | |
884 | ((int64_t)systime - (int64_t)last_time)); | |
885 | printf(_("Calculated Hardware Clock drift is %"PRId64".%06"PRId64" seconds\n"), | |
886 | (int64_t)tdrift_p->tv_sec, (int64_t)tdrift_p->tv_usec); | |
887 | } | |
888 | } | |
889 | ||
890 | /* | |
891 | * Write the contents of the <adjtime> structure to its disk file. | |
892 | * | |
893 | * But if the contents are clean (unchanged since read from disk), don't | |
894 | * bother. | |
895 | */ | |
896 | static int save_adjtime(const struct hwclock_control *ctl, | |
897 | const struct adjtime *adjtime) | |
898 | { | |
899 | char *content; /* Stuff to write to disk file */ | |
900 | FILE *fp; | |
901 | ||
902 | xasprintf(&content, "%f %"PRId64" %f\n%"PRId64"\n%s\n", | |
903 | adjtime->drift_factor, | |
904 | (int64_t)adjtime->last_adj_time, | |
905 | adjtime->not_adjusted, | |
906 | (int64_t)adjtime->last_calib_time, | |
907 | (adjtime->local_utc == LOCAL) ? "LOCAL" : "UTC"); | |
908 | ||
909 | if (ctl->verbose){ | |
910 | printf(_("New %s data:\n%s"), | |
911 | ctl->adj_file_name, content); | |
912 | } | |
913 | ||
914 | if (!ctl->testing) { | |
915 | int rc; | |
916 | ||
917 | fp = fopen(ctl->adj_file_name, "w"); | |
918 | if (fp == NULL) { | |
919 | warn(_("cannot open %s"), ctl->adj_file_name); | |
920 | return EXIT_FAILURE; | |
921 | } | |
922 | ||
923 | rc = fputs(content, fp) < 0; | |
924 | rc += close_stream(fp); | |
925 | ||
926 | if (rc) { | |
927 | warn(_("cannot update %s"), ctl->adj_file_name); | |
928 | return EXIT_FAILURE; | |
929 | } | |
930 | } | |
931 | return EXIT_SUCCESS; | |
932 | } | |
933 | ||
934 | /* | |
935 | * Do the adjustment requested, by 1) setting the Hardware Clock (if | |
936 | * necessary), and 2) updating the last-adjusted time in the adjtime | |
937 | * structure. | |
938 | * | |
939 | * Do not update anything if the Hardware Clock does not currently present a | |
940 | * valid time. | |
941 | * | |
942 | * <hclocktime> is the drift corrected time read from the Hardware Clock. | |
943 | * | |
944 | * <read_time> was the system time when the <hclocktime> was read, which due | |
945 | * to computational delay could be a short time ago. It is used to define a | |
946 | * trigger point for setting the Hardware Clock. The fractional part of the | |
947 | * Hardware clock set time is subtracted from read_time to 'refer back', or | |
948 | * delay, the trigger point. Fractional parts must be accounted for in this | |
949 | * way, because the Hardware Clock can only be set to a whole second. | |
950 | * | |
951 | * <universal>: the Hardware Clock is kept in UTC. | |
952 | * | |
953 | * <testing>: We are running in test mode (no updating of clock). | |
954 | * | |
955 | */ | |
956 | static void | |
957 | do_adjustment(const struct hwclock_control *ctl, struct adjtime *adjtime_p, | |
958 | const struct timeval hclocktime, | |
959 | const struct timeval read_time) | |
960 | { | |
961 | if (adjtime_p->last_adj_time == 0) { | |
962 | if (ctl->verbose) | |
963 | printf(_("Not setting clock because last adjustment time is zero, " | |
964 | "so history is bad.\n")); | |
965 | } else if (fabs(adjtime_p->drift_factor) > MAX_DRIFT) { | |
966 | if (ctl->verbose) | |
967 | printf(_("Not setting clock because drift factor %f is far too high.\n"), | |
968 | adjtime_p->drift_factor); | |
969 | } else { | |
970 | set_hardware_clock_exact(ctl, hclocktime.tv_sec, | |
971 | time_inc(read_time, | |
972 | -(hclocktime.tv_usec / 1E6))); | |
973 | adjtime_p->last_adj_time = hclocktime.tv_sec; | |
974 | adjtime_p->not_adjusted = 0; | |
975 | adjtime_p->dirty = 1; | |
976 | } | |
977 | } | |
978 | ||
979 | static void determine_clock_access_method(const struct hwclock_control *ctl) | |
980 | { | |
981 | ur = NULL; | |
982 | ||
983 | #ifdef USE_HWCLOCK_CMOS | |
984 | if (ctl->directisa) | |
985 | ur = probe_for_cmos_clock(); | |
986 | #endif | |
987 | #ifdef __linux__ | |
988 | if (!ur) | |
989 | ur = probe_for_rtc_clock(ctl); | |
990 | #endif | |
991 | if (ur) { | |
992 | if (ctl->verbose) | |
993 | puts(ur->interface_name); | |
994 | ||
995 | } else { | |
996 | if (ctl->verbose) | |
997 | printf(_("No usable clock interface found.\n")); | |
998 | ||
999 | warnx(_("Cannot access the Hardware Clock via " | |
1000 | "any known method.")); | |
1001 | ||
1002 | if (!ctl->verbose) | |
1003 | warnx(_("Use the --verbose option to see the " | |
1004 | "details of our search for an access " | |
1005 | "method.")); | |
1006 | hwclock_exit(ctl, EXIT_FAILURE); | |
1007 | } | |
1008 | } | |
1009 | ||
1010 | /* Do all the normal work of hwclock - read, set clock, etc. */ | |
1011 | static int | |
1012 | manipulate_clock(const struct hwclock_control *ctl, const time_t set_time, | |
1013 | const struct timeval startup_time, struct adjtime *adjtime) | |
1014 | { | |
1015 | /* The time at which we read the Hardware Clock */ | |
1016 | struct timeval read_time = { 0 }; | |
1017 | /* | |
1018 | * The Hardware Clock gives us a valid time, or at | |
1019 | * least something close enough to fool mktime(). | |
1020 | */ | |
1021 | int hclock_valid = 0; | |
1022 | /* | |
1023 | * Tick synchronized time read from the Hardware Clock and | |
1024 | * then drift corrected for all operations except --show. | |
1025 | */ | |
1026 | struct timeval hclocktime = { 0 }; | |
1027 | /* | |
1028 | * hclocktime correlated to startup_time. That is, what drift | |
1029 | * corrected Hardware Clock time would have been at start up. | |
1030 | */ | |
1031 | struct timeval startup_hclocktime = { 0 }; | |
1032 | /* Total Hardware Clock drift correction needed. */ | |
1033 | struct timeval tdrift = { 0 }; | |
1034 | ||
1035 | if ((ctl->set || ctl->systohc || ctl->adjust) && | |
1036 | (adjtime->local_utc == UTC) != ctl->universal) { | |
1037 | adjtime->local_utc = ctl->universal ? UTC : LOCAL; | |
1038 | adjtime->dirty = 1; | |
1039 | } | |
1040 | /* | |
1041 | * Negate the drift correction, because we want to 'predict' a | |
1042 | * Hardware Clock time that includes drift. | |
1043 | */ | |
1044 | if (ctl->predict) { | |
1045 | hclocktime = t2tv(set_time); | |
1046 | calculate_adjustment(ctl, adjtime->drift_factor, | |
1047 | adjtime->last_adj_time, | |
1048 | adjtime->not_adjusted, | |
1049 | hclocktime.tv_sec, &tdrift); | |
1050 | hclocktime = time_inc(hclocktime, (double) | |
1051 | -(tdrift.tv_sec + tdrift.tv_usec / 1E6)); | |
1052 | if (ctl->verbose) { | |
1053 | printf(_("Target date: %"PRId64"\n"), (int64_t)set_time); | |
1054 | printf(_("Predicted RTC: %"PRId64"\n"), (int64_t)hclocktime.tv_sec); | |
1055 | } | |
1056 | return display_time(hclocktime); | |
1057 | } | |
1058 | ||
1059 | if (ctl->systz) | |
1060 | return set_system_clock(ctl, startup_time); | |
1061 | ||
1062 | if (ur->get_permissions()) | |
1063 | return EXIT_FAILURE; | |
1064 | ||
1065 | /* | |
1066 | * Read and drift correct RTC time; except for RTC set functions | |
1067 | * without the --update-drift option because: 1) it's not needed; | |
1068 | * 2) it enables setting a corrupted RTC without reading it first; | |
1069 | * 3) it significantly reduces system shutdown time. | |
1070 | */ | |
1071 | if ( ! ((ctl->set || ctl->systohc) && !ctl->update)) { | |
1072 | /* | |
1073 | * Timing critical - do not change the order of, or put | |
1074 | * anything between the follow three statements. | |
1075 | * Synchronization failure MUST exit, because all drift | |
1076 | * operations are invalid without it. | |
1077 | */ | |
1078 | if (synchronize_to_clock_tick(ctl)) | |
1079 | return EXIT_FAILURE; | |
1080 | read_hardware_clock(ctl, &hclock_valid, &hclocktime.tv_sec); | |
1081 | gettimeofday(&read_time, NULL); | |
1082 | ||
1083 | if (!hclock_valid) { | |
1084 | warnx(_("RTC read returned an invalid value.")); | |
1085 | return EXIT_FAILURE; | |
1086 | } | |
1087 | /* | |
1088 | * Calculate and apply drift correction to the Hardware Clock | |
1089 | * time for everything except --show | |
1090 | */ | |
1091 | calculate_adjustment(ctl, adjtime->drift_factor, | |
1092 | adjtime->last_adj_time, | |
1093 | adjtime->not_adjusted, | |
1094 | hclocktime.tv_sec, &tdrift); | |
1095 | if (!ctl->show) | |
1096 | hclocktime = time_inc(tdrift, hclocktime.tv_sec); | |
1097 | ||
1098 | startup_hclocktime = | |
1099 | time_inc(hclocktime, time_diff(startup_time, read_time)); | |
1100 | } | |
1101 | if (ctl->show || ctl->get) { | |
1102 | return display_time(startup_hclocktime); | |
1103 | } | |
1104 | ||
1105 | if (ctl->set) { | |
1106 | set_hardware_clock_exact(ctl, set_time, startup_time); | |
1107 | if (!ctl->noadjfile) | |
1108 | adjust_drift_factor(ctl, adjtime, t2tv(set_time), | |
1109 | startup_hclocktime); | |
1110 | } else if (ctl->adjust) { | |
1111 | if (tdrift.tv_sec > 0 || tdrift.tv_sec < -1) | |
1112 | do_adjustment(ctl, adjtime, hclocktime, read_time); | |
1113 | else | |
1114 | printf(_("Needed adjustment is less than one second, " | |
1115 | "so not setting clock.\n")); | |
1116 | } else if (ctl->systohc) { | |
1117 | struct timeval nowtime, reftime; | |
1118 | /* | |
1119 | * We can only set_hardware_clock_exact to a | |
1120 | * whole seconds time, so we set it with | |
1121 | * reference to the most recent whole | |
1122 | * seconds time. | |
1123 | */ | |
1124 | gettimeofday(&nowtime, NULL); | |
1125 | reftime.tv_sec = nowtime.tv_sec; | |
1126 | reftime.tv_usec = 0; | |
1127 | set_hardware_clock_exact(ctl, (time_t) reftime.tv_sec, reftime); | |
1128 | if (!ctl->noadjfile) | |
1129 | adjust_drift_factor(ctl, adjtime, nowtime, | |
1130 | hclocktime); | |
1131 | } else if (ctl->hctosys) { | |
1132 | return set_system_clock(ctl, hclocktime); | |
1133 | } | |
1134 | if (!ctl->noadjfile && adjtime->dirty) | |
1135 | return save_adjtime(ctl, adjtime); | |
1136 | return EXIT_SUCCESS; | |
1137 | } | |
1138 | ||
1139 | /** | |
1140 | * Get or set the kernel RTC driver's epoch on Alpha machines. | |
1141 | * ISA machines are hard coded for 1900. | |
1142 | */ | |
1143 | #if defined(__linux__) && defined(__alpha__) | |
1144 | static void | |
1145 | manipulate_epoch(const struct hwclock_control *ctl) | |
1146 | { | |
1147 | if (ctl->getepoch) { | |
1148 | unsigned long epoch; | |
1149 | ||
1150 | if (get_epoch_rtc(ctl, &epoch)) | |
1151 | warnx(_("unable to read the RTC epoch.")); | |
1152 | else | |
1153 | printf(_("The RTC epoch is set to %lu.\n"), epoch); | |
1154 | } else if (ctl->setepoch) { | |
1155 | if (!ctl->epoch_option) | |
1156 | warnx(_("--epoch is required for --setepoch.")); | |
1157 | else if (!ctl->testing) | |
1158 | if (set_epoch_rtc(ctl)) | |
1159 | warnx(_("unable to set the RTC epoch.")); | |
1160 | } | |
1161 | } | |
1162 | #endif /* __linux__ __alpha__ */ | |
1163 | ||
1164 | #ifdef __linux__ | |
1165 | static int | |
1166 | manipulate_rtc_param(const struct hwclock_control *ctl) | |
1167 | { | |
1168 | if (ctl->param_get_option) { | |
1169 | uint64_t id = 0, value = 0; | |
1170 | ||
1171 | if (get_param_rtc(ctl, ctl->param_get_option, &id, &value)) { | |
1172 | warnx(_("unable to read the RTC parameter %s"), | |
1173 | ctl->param_get_option); | |
1174 | return 1; | |
1175 | } | |
1176 | ||
1177 | printf(_("The RTC parameter 0x%jx is set to 0x%jx.\n"), | |
1178 | (uintmax_t) id, (uintmax_t) value); | |
1179 | return 0; | |
1180 | ||
1181 | } else if (ctl->param_set_option) { | |
1182 | if (ctl->testing) | |
1183 | return 0; | |
1184 | ||
1185 | return set_param_rtc(ctl, ctl->param_set_option); | |
1186 | } | |
1187 | ||
1188 | return 1; | |
1189 | } | |
1190 | ||
1191 | static int | |
1192 | manipulate_rtc_voltage_low(const struct hwclock_control *ctl) | |
1193 | { | |
1194 | if (ctl->vl_read) { | |
1195 | if (rtc_vl_read(ctl)) | |
1196 | return 1; | |
1197 | } | |
1198 | if (ctl->vl_clear) { | |
1199 | if (rtc_vl_clear(ctl)) | |
1200 | return 1; | |
1201 | } | |
1202 | return 0; | |
1203 | } | |
1204 | #endif | |
1205 | ||
1206 | static void out_version(void) | |
1207 | { | |
1208 | printf(UTIL_LINUX_VERSION); | |
1209 | } | |
1210 | ||
1211 | static void __attribute__((__noreturn__)) | |
1212 | usage(void) | |
1213 | { | |
1214 | #ifdef __linux__ | |
1215 | const struct hwclock_param *param = get_hwclock_params(); | |
1216 | #endif | |
1217 | ||
1218 | fputs(USAGE_HEADER, stdout); | |
1219 | printf(_(" %s [function] [option...]\n"), program_invocation_short_name); | |
1220 | ||
1221 | fputs(USAGE_SEPARATOR, stdout); | |
1222 | puts(_("Time clocks utility.")); | |
1223 | ||
1224 | fputs(USAGE_FUNCTIONS, stdout); | |
1225 | puts(_(" -r, --show display the RTC time")); | |
1226 | puts(_(" --get display drift corrected RTC time")); | |
1227 | puts(_(" --set set the RTC according to --date")); | |
1228 | puts(_(" -s, --hctosys set the system time from the RTC")); | |
1229 | puts(_(" -w, --systohc set the RTC from the system time")); | |
1230 | puts(_(" --systz send timescale configurations to the kernel")); | |
1231 | puts(_(" -a, --adjust adjust the RTC to account for systematic drift")); | |
1232 | #if defined(__linux__) && defined(__alpha__) | |
1233 | puts(_(" --getepoch display the RTC epoch")); | |
1234 | puts(_(" --setepoch set the RTC epoch according to --epoch")); | |
1235 | #endif | |
1236 | #ifdef __linux__ | |
1237 | puts(_(" --param-get <param> display the RTC parameter")); | |
1238 | puts(_(" --param-set <param>=<value> set the RTC parameter")); | |
1239 | puts(_(" --vl-read read voltage low information")); | |
1240 | puts(_(" --vl-clear clear voltage low information")); | |
1241 | #endif | |
1242 | puts(_(" --predict predict the drifted RTC time according to --date")); | |
1243 | fputs(USAGE_OPTIONS, stdout); | |
1244 | puts(_(" -u, --utc the RTC timescale is UTC")); | |
1245 | puts(_(" -l, --localtime the RTC timescale is Local")); | |
1246 | #ifdef __linux__ | |
1247 | printf(_( | |
1248 | " -f, --rtc <file> use an alternate file to %1$s\n"), _PATH_RTC_DEV); | |
1249 | #endif | |
1250 | printf(_( | |
1251 | " --directisa use the ISA bus instead of %1$s access\n"), _PATH_RTC_DEV); | |
1252 | puts(_(" --date <time> date/time input for --set and --predict")); | |
1253 | puts(_(" --delay <sec> delay used when set new RTC time")); | |
1254 | #if defined(__linux__) && defined(__alpha__) | |
1255 | puts(_(" --epoch <year> epoch input for --setepoch")); | |
1256 | #endif | |
1257 | puts(_(" --update-drift update the RTC drift factor")); | |
1258 | printf(_( | |
1259 | " --noadjfile do not use %1$s\n"), _PATH_ADJTIME); | |
1260 | printf(_( | |
1261 | " --adjfile <file> use an alternate file to %1$s\n"), _PATH_ADJTIME); | |
1262 | puts(_(" --test dry run; implies --verbose")); | |
1263 | puts(_(" -v, --verbose display more details")); | |
1264 | ||
1265 | fputs(USAGE_SEPARATOR, stdout); | |
1266 | fprintf(stdout, USAGE_HELP_OPTIONS(33)); | |
1267 | ||
1268 | #ifdef __linux__ | |
1269 | fputs(USAGE_ARGUMENTS, stdout); | |
1270 | fputs(_(" <param> is either a numeric RTC parameter value or one of these aliases:"), stdout); | |
1271 | ||
1272 | while (param->name) { | |
1273 | fprintf(stdout, _(" - %1$s: %2$s (0x%3$x)\n"), param->name, param->help, param->id); | |
1274 | param++; | |
1275 | } | |
1276 | ||
1277 | fputs(_(" See Kernel's include/uapi/linux/rtc.h for parameters and values."), stdout); | |
1278 | fputs(USAGE_ARG_SEPARATOR, stdout); | |
1279 | fputs(_(" <param> and <value> accept hexadecimal values if prefixed with 0x, otherwise decimal."), stdout); | |
1280 | #endif | |
1281 | fprintf(stdout, USAGE_MAN_TAIL("hwclock(8)")); | |
1282 | exit(EXIT_SUCCESS); | |
1283 | } | |
1284 | ||
1285 | int main(int argc, char **argv) | |
1286 | { | |
1287 | struct hwclock_control ctl = { | |
1288 | .show = 1, /* default op is show */ | |
1289 | .rtc_delay = -1.0 /* unspecified */ | |
1290 | }; | |
1291 | struct timeval startup_time; | |
1292 | struct adjtime adjtime = { 0 }; | |
1293 | /* | |
1294 | * The time we started up, in seconds into the epoch, including | |
1295 | * fractions. | |
1296 | */ | |
1297 | time_t set_time = 0; /* Time to which user said to set Hardware Clock */ | |
1298 | int rc, c; | |
1299 | ||
1300 | /* Long only options. */ | |
1301 | enum { | |
1302 | OPT_ADJFILE = CHAR_MAX + 1, | |
1303 | OPT_DATE, | |
1304 | OPT_DELAY, | |
1305 | OPT_DIRECTISA, | |
1306 | OPT_EPOCH, | |
1307 | OPT_GET, | |
1308 | OPT_GETEPOCH, | |
1309 | OPT_NOADJFILE, | |
1310 | OPT_PARAM_GET, | |
1311 | OPT_PARAM_SET, | |
1312 | OPT_VL_READ, | |
1313 | OPT_VL_CLEAR, | |
1314 | OPT_PREDICT, | |
1315 | OPT_SET, | |
1316 | OPT_SETEPOCH, | |
1317 | OPT_SYSTZ, | |
1318 | OPT_TEST, | |
1319 | OPT_UPDATE | |
1320 | }; | |
1321 | ||
1322 | static const struct option longopts[] = { | |
1323 | { "adjust", no_argument, NULL, 'a' }, | |
1324 | { "help", no_argument, NULL, 'h' }, | |
1325 | { "localtime", no_argument, NULL, 'l' }, | |
1326 | { "show", no_argument, NULL, 'r' }, | |
1327 | { "hctosys", no_argument, NULL, 's' }, | |
1328 | { "utc", no_argument, NULL, 'u' }, | |
1329 | { "version", no_argument, NULL, 'V' }, | |
1330 | { "systohc", no_argument, NULL, 'w' }, | |
1331 | { "debug", no_argument, NULL, 'D' }, | |
1332 | { "ul-debug", required_argument, NULL, 'd' }, | |
1333 | { "verbose", no_argument, NULL, 'v' }, | |
1334 | { "set", no_argument, NULL, OPT_SET }, | |
1335 | #if defined(__linux__) && defined(__alpha__) | |
1336 | { "getepoch", no_argument, NULL, OPT_GETEPOCH }, | |
1337 | { "setepoch", no_argument, NULL, OPT_SETEPOCH }, | |
1338 | { "epoch", required_argument, NULL, OPT_EPOCH }, | |
1339 | #endif | |
1340 | #ifdef __linux__ | |
1341 | { "param-get", required_argument, NULL, OPT_PARAM_GET }, | |
1342 | { "param-set", required_argument, NULL, OPT_PARAM_SET }, | |
1343 | { "vl-read", no_argument, NULL, OPT_VL_READ }, | |
1344 | { "vl-clear", no_argument, NULL, OPT_VL_CLEAR }, | |
1345 | #endif | |
1346 | { "noadjfile", no_argument, NULL, OPT_NOADJFILE }, | |
1347 | { "directisa", no_argument, NULL, OPT_DIRECTISA }, | |
1348 | { "test", no_argument, NULL, OPT_TEST }, | |
1349 | { "date", required_argument, NULL, OPT_DATE }, | |
1350 | { "delay", required_argument, NULL, OPT_DELAY }, | |
1351 | #ifdef __linux__ | |
1352 | { "rtc", required_argument, NULL, 'f' }, | |
1353 | #endif | |
1354 | { "adjfile", required_argument, NULL, OPT_ADJFILE }, | |
1355 | { "systz", no_argument, NULL, OPT_SYSTZ }, | |
1356 | { "predict", no_argument, NULL, OPT_PREDICT }, | |
1357 | { "get", no_argument, NULL, OPT_GET }, | |
1358 | { "update-drift", no_argument, NULL, OPT_UPDATE }, | |
1359 | { NULL, 0, NULL, 0 } | |
1360 | }; | |
1361 | ||
1362 | static const ul_excl_t excl[] = { /* rows and cols in ASCII order */ | |
1363 | { 'a','r','s','w', | |
1364 | OPT_GET, OPT_GETEPOCH, OPT_PREDICT, | |
1365 | OPT_SET, OPT_SETEPOCH, OPT_SYSTZ }, | |
1366 | { 'l', 'u' }, | |
1367 | { OPT_ADJFILE, OPT_NOADJFILE }, | |
1368 | { OPT_NOADJFILE, OPT_UPDATE }, | |
1369 | { 0 } | |
1370 | }; | |
1371 | int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT; | |
1372 | ||
1373 | /* Remember what time we were invoked */ | |
1374 | gettimeofday(&startup_time, NULL); | |
1375 | ||
1376 | #ifdef HAVE_LIBAUDIT | |
1377 | hwaudit_fd = audit_open(); | |
1378 | if (hwaudit_fd < 0 && !(errno == EINVAL || errno == EPROTONOSUPPORT || | |
1379 | errno == EAFNOSUPPORT)) { | |
1380 | /* | |
1381 | * You get these error codes only when the kernel doesn't | |
1382 | * have audit compiled in. | |
1383 | */ | |
1384 | warnx(_("Unable to connect to audit system")); | |
1385 | return EXIT_FAILURE; | |
1386 | } | |
1387 | #endif | |
1388 | setlocale(LC_ALL, ""); | |
1389 | #ifdef LC_NUMERIC | |
1390 | /* | |
1391 | * We need LC_CTYPE and LC_TIME and LC_MESSAGES, but must avoid | |
1392 | * LC_NUMERIC since it gives problems when we write to /etc/adjtime. | |
1393 | * - gqueri@mail.dotcom.fr | |
1394 | */ | |
1395 | setlocale(LC_NUMERIC, "C"); | |
1396 | #endif | |
1397 | bindtextdomain(PACKAGE, LOCALEDIR); | |
1398 | textdomain(PACKAGE); | |
1399 | close_stdout_atexit(); | |
1400 | ||
1401 | while ((c = getopt_long(argc, argv, | |
1402 | "hvVDd:alrsuwf:", longopts, NULL)) != -1) { | |
1403 | ||
1404 | err_exclusive_options(c, longopts, excl, excl_st); | |
1405 | ||
1406 | switch (c) { | |
1407 | case 'D': | |
1408 | warnx(_("use --verbose, --debug has been deprecated.")); | |
1409 | break; | |
1410 | case 'v': | |
1411 | ctl.verbose = 1; | |
1412 | break; | |
1413 | case 'd': | |
1414 | hwclock_init_debug(optarg); | |
1415 | break; | |
1416 | case 'a': | |
1417 | ctl.adjust = 1; | |
1418 | ctl.show = 0; | |
1419 | ctl.hwaudit_on = 1; | |
1420 | break; | |
1421 | case 'l': | |
1422 | ctl.local_opt = 1; /* --localtime */ | |
1423 | break; | |
1424 | case 'r': | |
1425 | ctl.show = 1; | |
1426 | break; | |
1427 | case 's': | |
1428 | ctl.hctosys = 1; | |
1429 | ctl.show = 0; | |
1430 | ctl.hwaudit_on = 1; | |
1431 | break; | |
1432 | case 'u': | |
1433 | ctl.utc = 1; | |
1434 | break; | |
1435 | case 'w': | |
1436 | ctl.systohc = 1; | |
1437 | ctl.show = 0; | |
1438 | ctl.hwaudit_on = 1; | |
1439 | break; | |
1440 | case OPT_SET: | |
1441 | ctl.set = 1; | |
1442 | ctl.show = 0; | |
1443 | ctl.hwaudit_on = 1; | |
1444 | break; | |
1445 | #if defined(__linux__) && defined(__alpha__) | |
1446 | case OPT_GETEPOCH: | |
1447 | ctl.getepoch = 1; | |
1448 | ctl.show = 0; | |
1449 | break; | |
1450 | case OPT_SETEPOCH: | |
1451 | ctl.setepoch = 1; | |
1452 | ctl.show = 0; | |
1453 | ctl.hwaudit_on = 1; | |
1454 | break; | |
1455 | case OPT_EPOCH: | |
1456 | ctl.epoch_option = optarg; /* --epoch */ | |
1457 | break; | |
1458 | #endif | |
1459 | #ifdef __linux__ | |
1460 | case OPT_PARAM_GET: | |
1461 | ctl.param_get_option = optarg; | |
1462 | ctl.show = 0; | |
1463 | break; | |
1464 | case OPT_PARAM_SET: | |
1465 | ctl.param_set_option = optarg; | |
1466 | ctl.show = 0; | |
1467 | ctl.hwaudit_on = 1; | |
1468 | break; | |
1469 | case OPT_VL_READ: | |
1470 | ctl.vl_read = 1; | |
1471 | ctl.show = 0; | |
1472 | break; | |
1473 | case OPT_VL_CLEAR: | |
1474 | ctl.vl_clear = 1; | |
1475 | ctl.show = 0; | |
1476 | break; | |
1477 | #endif | |
1478 | case OPT_NOADJFILE: | |
1479 | ctl.noadjfile = 1; | |
1480 | break; | |
1481 | case OPT_DIRECTISA: | |
1482 | ctl.directisa = 1; | |
1483 | break; | |
1484 | case OPT_TEST: | |
1485 | ctl.testing = 1; /* --test */ | |
1486 | ctl.verbose = 1; | |
1487 | break; | |
1488 | case OPT_DATE: | |
1489 | ctl.date_opt = optarg; /* --date */ | |
1490 | break; | |
1491 | case OPT_DELAY: | |
1492 | ctl.rtc_delay = strtod_or_err(optarg, "invalid --delay argument"); | |
1493 | break; | |
1494 | case OPT_ADJFILE: | |
1495 | ctl.adj_file_name = optarg; /* --adjfile */ | |
1496 | break; | |
1497 | case OPT_SYSTZ: | |
1498 | ctl.systz = 1; /* --systz */ | |
1499 | ctl.show = 0; | |
1500 | ctl.hwaudit_on = 1; | |
1501 | break; | |
1502 | case OPT_PREDICT: | |
1503 | ctl.predict = 1; /* --predict */ | |
1504 | ctl.show = 0; | |
1505 | break; | |
1506 | case OPT_GET: | |
1507 | ctl.get = 1; /* --get */ | |
1508 | ctl.show = 0; | |
1509 | break; | |
1510 | case OPT_UPDATE: | |
1511 | ctl.update = 1; /* --update-drift */ | |
1512 | break; | |
1513 | #ifdef __linux__ | |
1514 | case 'f': | |
1515 | ctl.rtc_dev_name = optarg; /* --rtc */ | |
1516 | break; | |
1517 | #endif | |
1518 | ||
1519 | case 'V': /* --version */ | |
1520 | print_version(EXIT_SUCCESS); | |
1521 | case 'h': /* --help */ | |
1522 | usage(); | |
1523 | default: | |
1524 | errtryhelp(EXIT_FAILURE); | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | if (argc -= optind) { | |
1529 | warnx(_("too many arguments")); | |
1530 | errtryhelp(EXIT_FAILURE); | |
1531 | } | |
1532 | ||
1533 | if (!ctl.adj_file_name) | |
1534 | ctl.adj_file_name = _PATH_ADJTIME; | |
1535 | ||
1536 | if (ctl.update && !ctl.set && !ctl.systohc) { | |
1537 | warnx(_("--update-drift requires --set or --systohc")); | |
1538 | exit(EXIT_FAILURE); | |
1539 | } | |
1540 | ||
1541 | if (ctl.noadjfile && !ctl.utc && !ctl.local_opt) { | |
1542 | warnx(_("With --noadjfile, you must specify " | |
1543 | "either --utc or --localtime")); | |
1544 | exit(EXIT_FAILURE); | |
1545 | } | |
1546 | ||
1547 | if (ctl.set || ctl.predict) { | |
1548 | if (!ctl.date_opt) { | |
1549 | warnx(_("--date is required for --set or --predict")); | |
1550 | exit(EXIT_FAILURE); | |
1551 | } | |
1552 | #ifdef USE_HWCLOCK_GPLv3_DATETIME | |
1553 | /* date(1) compatible GPLv3 parser */ | |
1554 | struct timespec when = { 0 }; | |
1555 | ||
1556 | if (parse_date(&when, ctl.date_opt, NULL)) | |
1557 | set_time = when.tv_sec; | |
1558 | #else | |
1559 | /* minimalistic GPLv2 based parser */ | |
1560 | usec_t usec; | |
1561 | ||
1562 | if (parse_timestamp(ctl.date_opt, &usec) == 0) | |
1563 | set_time = (time_t) (usec / 1000000); | |
1564 | #endif | |
1565 | else { | |
1566 | warnx(_("invalid date '%s'"), ctl.date_opt); | |
1567 | exit(EXIT_FAILURE); | |
1568 | } | |
1569 | } | |
1570 | ||
1571 | #ifdef __linux__ | |
1572 | if (ctl.param_get_option || ctl.param_set_option) { | |
1573 | if (manipulate_rtc_param(&ctl)) | |
1574 | hwclock_exit(&ctl, EXIT_FAILURE); | |
1575 | ||
1576 | hwclock_exit(&ctl, EXIT_SUCCESS); | |
1577 | } | |
1578 | ||
1579 | if (ctl.vl_read || ctl.vl_clear) { | |
1580 | if (manipulate_rtc_voltage_low(&ctl)) | |
1581 | hwclock_exit(&ctl, EXIT_FAILURE); | |
1582 | ||
1583 | hwclock_exit(&ctl, EXIT_SUCCESS); | |
1584 | } | |
1585 | #endif | |
1586 | ||
1587 | #if defined(__linux__) && defined(__alpha__) | |
1588 | if (ctl.getepoch || ctl.setepoch) { | |
1589 | manipulate_epoch(&ctl); | |
1590 | hwclock_exit(&ctl, EXIT_SUCCESS); | |
1591 | } | |
1592 | #endif | |
1593 | ||
1594 | if (ctl.verbose) { | |
1595 | out_version(); | |
1596 | printf(_("System Time: %"PRId64".%06"PRId64"\n"), | |
1597 | (int64_t)startup_time.tv_sec, (int64_t)startup_time.tv_usec); | |
1598 | } | |
1599 | ||
1600 | if (!ctl.systz && !ctl.predict) | |
1601 | determine_clock_access_method(&ctl); | |
1602 | ||
1603 | if (!ctl.noadjfile && !(ctl.systz && (ctl.utc || ctl.local_opt))) { | |
1604 | if ((rc = read_adjtime(&ctl, &adjtime)) != 0) | |
1605 | hwclock_exit(&ctl, rc); | |
1606 | } else | |
1607 | /* Avoid writing adjtime file if we don't have to. */ | |
1608 | adjtime.dirty = 0; | |
1609 | ||
1610 | ctl.universal = hw_clock_is_utc(&ctl, &adjtime); | |
1611 | rc = manipulate_clock(&ctl, set_time, startup_time, &adjtime); | |
1612 | if (ctl.testing) | |
1613 | puts(_("Test mode: nothing was changed.")); | |
1614 | hwclock_exit(&ctl, rc); | |
1615 | return rc; /* Not reached */ | |
1616 | } | |
1617 | ||
1618 | void | |
1619 | hwclock_exit(const struct hwclock_control *ctl | |
1620 | #ifndef HAVE_LIBAUDIT | |
1621 | __attribute__((__unused__)) | |
1622 | #endif | |
1623 | , int status) | |
1624 | { | |
1625 | #ifdef HAVE_LIBAUDIT | |
1626 | if (ctl->hwaudit_on && !ctl->testing) { | |
1627 | audit_log_user_message(hwaudit_fd, AUDIT_USYS_CONFIG, | |
1628 | "op=change-system-time", NULL, NULL, NULL, | |
1629 | status == EXIT_SUCCESS ? 1 : 0); | |
1630 | } | |
1631 | close(hwaudit_fd); | |
1632 | #endif | |
1633 | exit(status); | |
1634 | } | |
1635 | ||
1636 | /* | |
1637 | * History of this program: | |
1638 | * | |
1639 | * 98.08.12 BJH Version 2.4 | |
1640 | * | |
1641 | * Don't use century byte from Hardware Clock. Add comments telling why. | |
1642 | * | |
1643 | * 98.06.20 BJH Version 2.3. | |
1644 | * | |
1645 | * Make --hctosys set the kernel timezone from TZ environment variable | |
1646 | * and/or /usr/lib/zoneinfo. From Klaus Ripke (klaus@ripke.com). | |
1647 | * | |
1648 | * 98.03.05 BJH. Version 2.2. | |
1649 | * | |
1650 | * Add --getepoch and --setepoch. | |
1651 | * | |
1652 | * Fix some word length things so it works on Alpha. | |
1653 | * | |
1654 | * Make it work when /dev/rtc doesn't have the interrupt functions. In this | |
1655 | * case, busywait for the top of a second instead of blocking and waiting | |
1656 | * for the update complete interrupt. | |
1657 | * | |
1658 | * Fix a bunch of bugs too numerous to mention. | |
1659 | * | |
1660 | * 97.06.01: BJH. Version 2.1. Read and write the century byte (Byte 50) of | |
1661 | * the ISA Hardware Clock when using direct ISA I/O. Problem discovered by | |
1662 | * job (jei@iclnl.icl.nl). | |
1663 | * | |
1664 | * Use the rtc clock access method in preference to the KDGHWCLK method. | |
1665 | * Problem discovered by Andreas Schwab <schwab@LS5.informatik.uni-dortmund.de>. | |
1666 | * | |
1667 | * November 1996: Version 2.0.1. Modifications by Nicolai Langfeldt | |
1668 | * (janl@math.uio.no) to make it compile on linux 1.2 machines as well as | |
1669 | * more recent versions of the kernel. Introduced the NO_CLOCK access method | |
1670 | * and wrote feature test code to detect absence of rtc headers. | |
1671 | * | |
1672 | *************************************************************************** | |
1673 | * Maintenance notes | |
1674 | * | |
1675 | * To compile this, you must use GNU compiler optimization (-O option) in | |
1676 | * order to make the "extern inline" functions from asm/io.h (inb(), etc.) | |
1677 | * compile. If you don't optimize, which means the compiler will generate no | |
1678 | * inline functions, the references to these functions in this program will | |
1679 | * be compiled as external references. Since you probably won't be linking | |
1680 | * with any functions by these names, you will have unresolved external | |
1681 | * references when you link. | |
1682 | * | |
1683 | * Here's some info on how we must deal with the time that elapses while | |
1684 | * this program runs: There are two major delays as we run: | |
1685 | * | |
1686 | * 1) Waiting up to 1 second for a transition of the Hardware Clock so | |
1687 | * we are synchronized to the Hardware Clock. | |
1688 | * 2) Running the "date" program to interpret the value of our --date | |
1689 | * option. | |
1690 | * | |
1691 | * Reading the /etc/adjtime file is the next biggest source of delay and | |
1692 | * uncertainty. | |
1693 | * | |
1694 | * The user wants to know what time it was at the moment they invoked us, not | |
1695 | * some arbitrary time later. And in setting the clock, they are giving us the | |
1696 | * time at the moment we are invoked, so if we set the clock some time | |
1697 | * later, we have to add some time to that. | |
1698 | * | |
1699 | * So we check the system time as soon as we start up, then run "date" and | |
1700 | * do file I/O if necessary, then wait to synchronize with a Hardware Clock | |
1701 | * edge, then check the system time again to see how much time we spent. We | |
1702 | * immediately read the clock then and (if appropriate) report that time, | |
1703 | * and additionally, the delay we measured. | |
1704 | * | |
1705 | * If we're setting the clock to a time given by the user, we wait some more | |
1706 | * so that the total delay is an integral number of seconds, then set the | |
1707 | * Hardware Clock to the time the user requested plus that integral number | |
1708 | * of seconds. N.B. The Hardware Clock can only be set in integral seconds. | |
1709 | * | |
1710 | * If we're setting the clock to the system clock value, we wait for the | |
1711 | * system clock to reach the top of a second, and then set the Hardware | |
1712 | * Clock to the system clock's value. | |
1713 | * | |
1714 | * Here's an interesting point about setting the Hardware Clock: On my | |
1715 | * machine, when you set it, it sets to that precise time. But one can | |
1716 | * imagine another clock whose update oscillator marches on a steady one | |
1717 | * second period, so updating the clock between any two oscillator ticks is | |
1718 | * the same as updating it right at the earlier tick. To avoid any | |
1719 | * complications that might cause, we set the clock as soon as possible | |
1720 | * after an oscillator tick. | |
1721 | * | |
1722 | * About synchronizing to the Hardware Clock when reading the time: The | |
1723 | * precision of the Hardware Clock counters themselves is one second. You | |
1724 | * can't read the counters and find out that is 12:01:02.5. But if you | |
1725 | * consider the location in time of the counter's ticks as part of its | |
1726 | * value, then its precision is as infinite as time is continuous! What I'm | |
1727 | * saying is this: To find out the _exact_ time in the hardware clock, we | |
1728 | * wait until the next clock tick (the next time the second counter changes) | |
1729 | * and measure how long we had to wait. We then read the value of the clock | |
1730 | * counters and subtract the wait time and we know precisely what time it | |
1731 | * was when we set out to query the time. | |
1732 | * | |
1733 | * hwclock uses this method, and considers the Hardware Clock to have | |
1734 | * infinite precision. | |
1735 | */ |