From bbc98d32560cc456531bf254f7b69054921082bd Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Mon, 7 May 2012 21:06:55 +0200 Subject: util: split-out hwclock.[ch] --- src/shared/hwclock.c | 228 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) create mode 100644 src/shared/hwclock.c (limited to 'src/shared/hwclock.c') diff --git a/src/shared/hwclock.c b/src/shared/hwclock.c new file mode 100644 index 0000000000..d40bb2653f --- /dev/null +++ b/src/shared/hwclock.c @@ -0,0 +1,228 @@ +/*-*- 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 . +***/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; +} -- cgit v1.2.3-54-g00ecf