Lennart Poettering
0c69794138
These lines are generally out-of-date, incomplete and unnecessary. With SPDX and git repository much more accurate and fine grained information about licensing and authorship is available, hence let's drop the per-file copyright notice. Of course, removing copyright lines of others is problematic, hence this commit only removes my own lines and leaves all others untouched. It might be nicer if sooner or later those could go away too, making git the only and accurate source of authorship information.
149 lines
3.7 KiB
C
149 lines
3.7 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <stdbool.h>
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#include <time.h>
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#include <linux/rtc.h>
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#include <stdio.h>
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#include <sys/ioctl.h>
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#include <sys/time.h>
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#include "clock-util.h"
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#include "fd-util.h"
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#include "macro.h"
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#include "string-util.h"
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#include "util.h"
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int clock_get_hwclock(struct tm *tm) {
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_cleanup_close_ int fd = -1;
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assert(tm);
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fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC);
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if (fd < 0)
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return -errno;
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/* This leaves the timezone fields of struct tm
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* uninitialized! */
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if (ioctl(fd, RTC_RD_TIME, tm) < 0)
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return -errno;
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/* We don't know daylight saving, so we reset this in order not
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* to confuse mktime(). */
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tm->tm_isdst = -1;
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return 0;
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}
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int clock_set_hwclock(const struct tm *tm) {
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_cleanup_close_ int fd = -1;
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assert(tm);
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fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC);
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if (fd < 0)
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return -errno;
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if (ioctl(fd, RTC_SET_TIME, tm) < 0)
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return -errno;
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return 0;
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}
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int clock_is_localtime(const char* adjtime_path) {
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_cleanup_fclose_ FILE *f;
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if (!adjtime_path)
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adjtime_path = "/etc/adjtime";
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/*
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* The third line of adjtime is "UTC" or "LOCAL" or nothing.
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* # /etc/adjtime
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* 0.0 0 0
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* 0
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* UTC
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*/
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f = fopen(adjtime_path, "re");
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if (f) {
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char line[LINE_MAX];
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bool b;
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b = fgets(line, sizeof(line), f) &&
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fgets(line, sizeof(line), f) &&
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fgets(line, sizeof(line), f);
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if (!b)
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/* less than three lines -> default to UTC */
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return 0;
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truncate_nl(line);
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return streq(line, "LOCAL");
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} else if (errno != ENOENT)
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return -errno;
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/* adjtime not present -> default to UTC */
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return 0;
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}
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int clock_set_timezone(int *min) {
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const struct timeval *tv_null = NULL;
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struct timespec ts;
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struct tm *tm;
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int minutesdelta;
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struct timezone tz;
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assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
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assert_se(tm = localtime(&ts.tv_sec));
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minutesdelta = tm->tm_gmtoff / 60;
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tz.tz_minuteswest = -minutesdelta;
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tz.tz_dsttime = 0; /* DST_NONE */
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/*
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* If the RTC does not run in UTC but in local time, the very first
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* call to settimeofday() will set the kernel's timezone and will warp the
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* system clock, so that it runs in UTC instead of the local time we
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* have read from the RTC.
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*/
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if (settimeofday(tv_null, &tz) < 0)
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return negative_errno();
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if (min)
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*min = minutesdelta;
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return 0;
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}
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int clock_reset_timewarp(void) {
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const struct timeval *tv_null = NULL;
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struct timezone tz;
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tz.tz_minuteswest = 0;
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tz.tz_dsttime = 0; /* DST_NONE */
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/*
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* The very first call to settimeofday() does time warp magic. Do a
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* dummy call here, so the time warping is sealed and all later calls
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* behave as expected.
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*/
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if (settimeofday(tv_null, &tz) < 0)
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return -errno;
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return 0;
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}
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#define TIME_EPOCH_USEC ((usec_t) TIME_EPOCH * USEC_PER_SEC)
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int clock_apply_epoch(void) {
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struct timespec ts;
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if (now(CLOCK_REALTIME) >= TIME_EPOCH_USEC)
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return 0;
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if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, TIME_EPOCH_USEC)) < 0)
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return -errno;
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return 1;
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}
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