--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010-2012 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <sys/prctl.h>
+#include <sys/time.h>
+#include <linux/rtc.h>
+
+#include "macro.h"
+#include "util.h"
+#include "log.h"
+#include "strv.h"
+#include "hwclock.h"
+
+static int rtc_open(int flags) {
+ int fd;
+ DIR *d;
+
+ /* First, we try to make use of the /dev/rtc symlink. If that
+ * doesn't exist, we open the first RTC which has hctosys=1
+ * set. If we don't find any we just take the first RTC that
+ * exists at all. */
+
+ fd = open("/dev/rtc", flags);
+ if (fd >= 0)
+ return fd;
+
+ d = opendir("/sys/class/rtc");
+ if (!d)
+ goto fallback;
+
+ for (;;) {
+ char *p, *v;
+ struct dirent buf, *de;
+ int r;
+
+ r = readdir_r(d, &buf, &de);
+ if (r != 0)
+ goto fallback;
+
+ if (!de)
+ goto fallback;
+
+ if (ignore_file(de->d_name))
+ continue;
+
+ p = join("/sys/class/rtc/", de->d_name, "/hctosys", NULL);
+ if (!p) {
+ closedir(d);
+ return -ENOMEM;
+ }
+
+ r = read_one_line_file(p, &v);
+ free(p);
+
+ if (r < 0)
+ continue;
+
+ r = parse_boolean(v);
+ free(v);
+
+ if (r <= 0)
+ continue;
+
+ p = strappend("/dev/", de->d_name);
+ fd = open(p, flags);
+ free(p);
+
+ if (fd >= 0) {
+ closedir(d);
+ return fd;
+ }
+ }
+
+fallback:
+ if (d)
+ closedir(d);
+
+ fd = open("/dev/rtc0", flags);
+ if (fd < 0)
+ return -errno;
+
+ return fd;
+}
+
+int hwclock_get_time(struct tm *tm) {
+ int fd;
+ int err = 0;
+
+ assert(tm);
+
+ fd = rtc_open(O_RDONLY|O_CLOEXEC);
+ if (fd < 0)
+ return -errno;
+
+ /* This leaves the timezone fields of struct tm
+ * uninitialized! */
+ if (ioctl(fd, RTC_RD_TIME, tm) < 0)
+ err = -errno;
+
+ /* We don't know daylight saving, so we reset this in order not
+ * to confused mktime(). */
+ tm->tm_isdst = -1;
+
+ close_nointr_nofail(fd);
+
+ return err;
+}
+
+int hwclock_set_time(const struct tm *tm) {
+ int fd;
+ int err = 0;
+
+ assert(tm);
+
+ fd = rtc_open(O_RDONLY|O_CLOEXEC);
+ if (fd < 0)
+ return -errno;
+
+ if (ioctl(fd, RTC_SET_TIME, tm) < 0)
+ err = -errno;
+
+ close_nointr_nofail(fd);
+
+ return err;
+}
+int hwclock_is_localtime(void) {
+ FILE *f;
+ bool local = false;
+
+ /*
+ * The third line of adjtime is "UTC" or "LOCAL" or nothing.
+ * # /etc/adjtime
+ * 0.0 0 0
+ * 0
+ * UTC
+ */
+ f = fopen("/etc/adjtime", "re");
+ if (f) {
+ char line[LINE_MAX];
+ bool b;
+
+ b = fgets(line, sizeof(line), f) &&
+ fgets(line, sizeof(line), f) &&
+ fgets(line, sizeof(line), f);
+
+ fclose(f);
+
+ if (!b)
+ return -EIO;
+
+ truncate_nl(line);
+ local = streq(line, "LOCAL");
+
+ } else if (errno != -ENOENT)
+ return -errno;
+
+ return local;
+}
+
+int hwclock_apply_localtime_delta(int *min) {
+ const struct timeval *tv_null = NULL;
+ struct timespec ts;
+ struct tm *tm;
+ int minuteswest;
+ struct timezone tz;
+
+ assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0);
+ assert_se(tm = localtime(&ts.tv_sec));
+ minuteswest = tm->tm_gmtoff / 60;
+
+ tz.tz_minuteswest = -minuteswest;
+ tz.tz_dsttime = 0; /* DST_NONE*/
+
+ /*
+ * If the hardware clock does not run in UTC, but in local time:
+ * The very first time we set the kernel's timezone, it will warp
+ * the clock so that it runs in UTC instead of local time.
+ */
+ if (settimeofday(tv_null, &tz) < 0)
+ return -errno;
+ if (min)
+ *min = minuteswest;
+ return 0;
+}
+
+int hwclock_reset_localtime_delta(void) {
+ const struct timeval *tv_null = NULL;
+ struct timezone tz;
+
+ tz.tz_minuteswest = 0;
+ tz.tz_dsttime = 0; /* DST_NONE*/
+
+ if (settimeofday(tv_null, &tz) < 0)
+ return -errno;
+
+ return 0;
+}
~ianmdlvl / elogind.git / blobdiff