]>
Commit | Line | Data |
---|---|---|
663996b3 MS |
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 | ||
22 | #include <assert.h> | |
23 | #include <string.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
26 | #include <stdlib.h> | |
27 | #include <signal.h> | |
28 | #include <stdio.h> | |
29 | #include <sys/types.h> | |
30 | #include <sys/stat.h> | |
31 | #include <fcntl.h> | |
32 | #include <sys/ioctl.h> | |
33 | #include <stdarg.h> | |
34 | #include <ctype.h> | |
35 | #include <sys/prctl.h> | |
36 | #include <sys/time.h> | |
37 | #include <linux/rtc.h> | |
38 | ||
39 | #include "macro.h" | |
40 | #include "util.h" | |
41 | #include "log.h" | |
42 | #include "strv.h" | |
60f067b4 | 43 | #include "clock-util.h" |
663996b3 MS |
44 | #include "fileio.h" |
45 | ||
60f067b4 JS |
46 | int clock_get_hwclock(struct tm *tm) { |
47 | _cleanup_close_ int fd = -1; | |
663996b3 MS |
48 | |
49 | assert(tm); | |
50 | ||
51 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); | |
52 | if (fd < 0) | |
53 | return -errno; | |
54 | ||
55 | /* This leaves the timezone fields of struct tm | |
56 | * uninitialized! */ | |
57 | if (ioctl(fd, RTC_RD_TIME, tm) < 0) | |
60f067b4 | 58 | return -errno; |
663996b3 MS |
59 | |
60 | /* We don't know daylight saving, so we reset this in order not | |
60f067b4 | 61 | * to confuse mktime(). */ |
663996b3 MS |
62 | tm->tm_isdst = -1; |
63 | ||
60f067b4 | 64 | return 0; |
663996b3 MS |
65 | } |
66 | ||
60f067b4 JS |
67 | int clock_set_hwclock(const struct tm *tm) { |
68 | _cleanup_close_ int fd = -1; | |
663996b3 MS |
69 | |
70 | assert(tm); | |
71 | ||
72 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); | |
73 | if (fd < 0) | |
74 | return -errno; | |
75 | ||
76 | if (ioctl(fd, RTC_SET_TIME, tm) < 0) | |
60f067b4 | 77 | return -errno; |
663996b3 | 78 | |
60f067b4 | 79 | return 0; |
663996b3 MS |
80 | } |
81 | ||
60f067b4 | 82 | int clock_is_localtime(void) { |
663996b3 MS |
83 | _cleanup_fclose_ FILE *f; |
84 | ||
85 | /* | |
86 | * The third line of adjtime is "UTC" or "LOCAL" or nothing. | |
87 | * # /etc/adjtime | |
88 | * 0.0 0 0 | |
89 | * 0 | |
90 | * UTC | |
91 | */ | |
92 | f = fopen("/etc/adjtime", "re"); | |
93 | if (f) { | |
94 | char line[LINE_MAX]; | |
95 | bool b; | |
96 | ||
97 | b = fgets(line, sizeof(line), f) && | |
98 | fgets(line, sizeof(line), f) && | |
99 | fgets(line, sizeof(line), f); | |
100 | if (!b) | |
101 | return -EIO; | |
102 | ||
103 | truncate_nl(line); | |
104 | return streq(line, "LOCAL"); | |
105 | ||
106 | } else if (errno != ENOENT) | |
107 | return -errno; | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
60f067b4 | 112 | int clock_set_timezone(int *min) { |
663996b3 MS |
113 | const struct timeval *tv_null = NULL; |
114 | struct timespec ts; | |
115 | struct tm *tm; | |
116 | int minutesdelta; | |
117 | struct timezone tz; | |
118 | ||
119 | assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0); | |
120 | assert_se(tm = localtime(&ts.tv_sec)); | |
121 | minutesdelta = tm->tm_gmtoff / 60; | |
122 | ||
123 | tz.tz_minuteswest = -minutesdelta; | |
124 | tz.tz_dsttime = 0; /* DST_NONE*/ | |
125 | ||
126 | /* | |
5eef597e MP |
127 | * If the RTC does not run in UTC but in local time, the very first |
128 | * call to settimeofday() will set the kernel's timezone and will warp the | |
129 | * system clock, so that it runs in UTC instead of the local time we | |
130 | * have read from the RTC. | |
663996b3 MS |
131 | */ |
132 | if (settimeofday(tv_null, &tz) < 0) | |
133 | return -errno; | |
134 | if (min) | |
135 | *min = minutesdelta; | |
136 | return 0; | |
137 | } | |
138 | ||
5eef597e | 139 | int clock_reset_timewarp(void) { |
663996b3 MS |
140 | const struct timeval *tv_null = NULL; |
141 | struct timezone tz; | |
142 | ||
143 | tz.tz_minuteswest = 0; | |
144 | tz.tz_dsttime = 0; /* DST_NONE*/ | |
145 | ||
146 | /* | |
5eef597e MP |
147 | * The very first call to settimeofday() does time warp magic. Do a |
148 | * dummy call here, so the time warping is sealed and all later calls | |
149 | * behave as expected. | |
663996b3 MS |
150 | */ |
151 | if (settimeofday(tv_null, &tz) < 0) | |
152 | return -errno; | |
153 | ||
154 | return 0; | |
155 | } |