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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010-2012 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
bbc98d32 | 22 | #include <errno.h> |
bbc98d32 | 23 | #include <stdio.h> |
bbc98d32 KS |
24 | #include <fcntl.h> |
25 | #include <sys/ioctl.h> | |
bbc98d32 KS |
26 | #include <sys/time.h> |
27 | #include <linux/rtc.h> | |
28 | ||
29 | #include "macro.h" | |
30 | #include "util.h" | |
24efb112 | 31 | #include "clock-util.h" |
bbc98d32 | 32 | |
60989612 | 33 | int clock_get_hwclock(struct tm *tm) { |
8e64fd11 | 34 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
35 | |
36 | assert(tm); | |
37 | ||
67fb4482 | 38 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
39 | if (fd < 0) |
40 | return -errno; | |
41 | ||
42 | /* This leaves the timezone fields of struct tm | |
43 | * uninitialized! */ | |
44 | if (ioctl(fd, RTC_RD_TIME, tm) < 0) | |
8e64fd11 | 45 | return -errno; |
bbc98d32 KS |
46 | |
47 | /* We don't know daylight saving, so we reset this in order not | |
2f6a5907 | 48 | * to confuse mktime(). */ |
bbc98d32 KS |
49 | tm->tm_isdst = -1; |
50 | ||
8e64fd11 | 51 | return 0; |
bbc98d32 KS |
52 | } |
53 | ||
60989612 | 54 | int clock_set_hwclock(const struct tm *tm) { |
8e64fd11 | 55 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
56 | |
57 | assert(tm); | |
58 | ||
67fb4482 | 59 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
60 | if (fd < 0) |
61 | return -errno; | |
62 | ||
63 | if (ioctl(fd, RTC_SET_TIME, tm) < 0) | |
8e64fd11 | 64 | return -errno; |
bbc98d32 | 65 | |
8e64fd11 | 66 | return 0; |
bbc98d32 | 67 | } |
a866073d | 68 | |
24efb112 | 69 | int clock_is_localtime(void) { |
7fd1b19b | 70 | _cleanup_fclose_ FILE *f; |
bbc98d32 KS |
71 | |
72 | /* | |
73 | * The third line of adjtime is "UTC" or "LOCAL" or nothing. | |
74 | * # /etc/adjtime | |
75 | * 0.0 0 0 | |
76 | * 0 | |
77 | * UTC | |
78 | */ | |
79 | f = fopen("/etc/adjtime", "re"); | |
80 | if (f) { | |
81 | char line[LINE_MAX]; | |
82 | bool b; | |
83 | ||
84 | b = fgets(line, sizeof(line), f) && | |
85 | fgets(line, sizeof(line), f) && | |
86 | fgets(line, sizeof(line), f); | |
bbc98d32 KS |
87 | if (!b) |
88 | return -EIO; | |
89 | ||
90 | truncate_nl(line); | |
8e2f9ebf | 91 | return streq(line, "LOCAL"); |
bbc98d32 | 92 | |
bcb161b0 | 93 | } else if (errno != ENOENT) |
bbc98d32 KS |
94 | return -errno; |
95 | ||
8e2f9ebf | 96 | return 0; |
bbc98d32 KS |
97 | } |
98 | ||
24efb112 | 99 | int clock_set_timezone(int *min) { |
bbc98d32 KS |
100 | const struct timeval *tv_null = NULL; |
101 | struct timespec ts; | |
102 | struct tm *tm; | |
19e65613 | 103 | int minutesdelta; |
bbc98d32 KS |
104 | struct timezone tz; |
105 | ||
106 | assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0); | |
107 | assert_se(tm = localtime(&ts.tv_sec)); | |
19e65613 | 108 | minutesdelta = tm->tm_gmtoff / 60; |
bbc98d32 | 109 | |
19e65613 | 110 | tz.tz_minuteswest = -minutesdelta; |
cc13b327 | 111 | tz.tz_dsttime = 0; /* DST_NONE */ |
bbc98d32 KS |
112 | |
113 | /* | |
c264aeab KS |
114 | * If the RTC does not run in UTC but in local time, the very first |
115 | * call to settimeofday() will set the kernel's timezone and will warp the | |
116 | * system clock, so that it runs in UTC instead of the local time we | |
117 | * have read from the RTC. | |
bbc98d32 KS |
118 | */ |
119 | if (settimeofday(tv_null, &tz) < 0) | |
120 | return -errno; | |
121 | if (min) | |
19e65613 | 122 | *min = minutesdelta; |
bbc98d32 KS |
123 | return 0; |
124 | } | |
125 | ||
c264aeab | 126 | int clock_reset_timewarp(void) { |
bbc98d32 KS |
127 | const struct timeval *tv_null = NULL; |
128 | struct timezone tz; | |
129 | ||
130 | tz.tz_minuteswest = 0; | |
cc13b327 | 131 | tz.tz_dsttime = 0; /* DST_NONE */ |
bbc98d32 | 132 | |
72edcff5 | 133 | /* |
c264aeab KS |
134 | * The very first call to settimeofday() does time warp magic. Do a |
135 | * dummy call here, so the time warping is sealed and all later calls | |
136 | * behave as expected. | |
72edcff5 | 137 | */ |
bbc98d32 KS |
138 | if (settimeofday(tv_null, &tz) < 0) |
139 | return -errno; | |
140 | ||
141 | return 0; | |
142 | } |