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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
bbc98d32 | 2 | |
bbc98d32 | 3 | #include <errno.h> |
bbc98d32 | 4 | #include <fcntl.h> |
11c3a366 TA |
5 | #include <limits.h> |
6 | #include <stdbool.h> | |
7 | #include <time.h> | |
07630cea LP |
8 | #include <linux/rtc.h> |
9 | #include <stdio.h> | |
bbc98d32 | 10 | #include <sys/ioctl.h> |
bbc98d32 | 11 | #include <sys/time.h> |
bbc98d32 | 12 | |
6d3db278 | 13 | #include "alloc-util.h" |
3ffd4af2 LP |
14 | #include "clock-util.h" |
15 | #include "fd-util.h" | |
6d3db278 | 16 | #include "fileio.h" |
bbc98d32 | 17 | #include "macro.h" |
07630cea | 18 | #include "string-util.h" |
9c4615fb | 19 | #include "util.h" |
bbc98d32 | 20 | |
60989612 | 21 | int clock_get_hwclock(struct tm *tm) { |
8e64fd11 | 22 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
23 | |
24 | assert(tm); | |
25 | ||
67fb4482 | 26 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
27 | if (fd < 0) |
28 | return -errno; | |
29 | ||
30 | /* This leaves the timezone fields of struct tm | |
31 | * uninitialized! */ | |
32 | if (ioctl(fd, RTC_RD_TIME, tm) < 0) | |
8e64fd11 | 33 | return -errno; |
bbc98d32 KS |
34 | |
35 | /* We don't know daylight saving, so we reset this in order not | |
2f6a5907 | 36 | * to confuse mktime(). */ |
bbc98d32 KS |
37 | tm->tm_isdst = -1; |
38 | ||
8e64fd11 | 39 | return 0; |
bbc98d32 KS |
40 | } |
41 | ||
60989612 | 42 | int clock_set_hwclock(const struct tm *tm) { |
8e64fd11 | 43 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
44 | |
45 | assert(tm); | |
46 | ||
67fb4482 | 47 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
48 | if (fd < 0) |
49 | return -errno; | |
50 | ||
51 | if (ioctl(fd, RTC_SET_TIME, tm) < 0) | |
8e64fd11 | 52 | return -errno; |
bbc98d32 | 53 | |
8e64fd11 | 54 | return 0; |
bbc98d32 | 55 | } |
a866073d | 56 | |
6369641d | 57 | int clock_is_localtime(const char* adjtime_path) { |
7fd1b19b | 58 | _cleanup_fclose_ FILE *f; |
6d3db278 | 59 | int r; |
bbc98d32 | 60 | |
234519ae | 61 | if (!adjtime_path) |
6369641d MP |
62 | adjtime_path = "/etc/adjtime"; |
63 | ||
bbc98d32 KS |
64 | /* |
65 | * The third line of adjtime is "UTC" or "LOCAL" or nothing. | |
66 | * # /etc/adjtime | |
67 | * 0.0 0 0 | |
68 | * 0 | |
69 | * UTC | |
70 | */ | |
6369641d | 71 | f = fopen(adjtime_path, "re"); |
bbc98d32 | 72 | if (f) { |
6d3db278 LP |
73 | _cleanup_free_ char *line = NULL; |
74 | unsigned i; | |
75 | ||
76 | for (i = 0; i < 2; i++) { /* skip the first two lines */ | |
77 | r = read_line(f, LONG_LINE_MAX, NULL); | |
78 | if (r < 0) | |
79 | return r; | |
80 | if (r == 0) | |
81 | return false; /* less than three lines → default to UTC */ | |
82 | } | |
83 | ||
84 | r = read_line(f, LONG_LINE_MAX, &line); | |
85 | if (r < 0) | |
86 | return r; | |
87 | if (r == 0) | |
88 | return false; /* less than three lines → default to UTC */ | |
bbc98d32 | 89 | |
8e2f9ebf | 90 | return streq(line, "LOCAL"); |
bbc98d32 | 91 | |
bcb161b0 | 92 | } else if (errno != ENOENT) |
bbc98d32 KS |
93 | return -errno; |
94 | ||
6d3db278 LP |
95 | /* adjtime not present → default to UTC */ |
96 | return false; | |
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; | |
e0f691e1 | 102 | struct tm tm; |
19e65613 | 103 | int minutesdelta; |
bbc98d32 KS |
104 | struct timezone tz; |
105 | ||
106 | assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0); | |
e0f691e1 YW |
107 | assert_se(localtime_r(&ts.tv_sec, &tm)); |
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) | |
9c4615fb ZJS |
120 | return negative_errno(); |
121 | ||
bbc98d32 | 122 | if (min) |
19e65613 | 123 | *min = minutesdelta; |
bbc98d32 KS |
124 | return 0; |
125 | } | |
126 | ||
c264aeab | 127 | int clock_reset_timewarp(void) { |
bbc98d32 KS |
128 | const struct timeval *tv_null = NULL; |
129 | struct timezone tz; | |
130 | ||
131 | tz.tz_minuteswest = 0; | |
cc13b327 | 132 | tz.tz_dsttime = 0; /* DST_NONE */ |
bbc98d32 | 133 | |
72edcff5 | 134 | /* |
c264aeab KS |
135 | * The very first call to settimeofday() does time warp magic. Do a |
136 | * dummy call here, so the time warping is sealed and all later calls | |
137 | * behave as expected. | |
72edcff5 | 138 | */ |
bbc98d32 KS |
139 | if (settimeofday(tv_null, &tz) < 0) |
140 | return -errno; | |
141 | ||
142 | return 0; | |
143 | } | |
021dd87b LP |
144 | |
145 | #define TIME_EPOCH_USEC ((usec_t) TIME_EPOCH * USEC_PER_SEC) | |
146 | ||
147 | int clock_apply_epoch(void) { | |
148 | struct timespec ts; | |
149 | ||
150 | if (now(CLOCK_REALTIME) >= TIME_EPOCH_USEC) | |
151 | return 0; | |
152 | ||
153 | if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, TIME_EPOCH_USEC)) < 0) | |
154 | return -errno; | |
155 | ||
156 | return 1; | |
157 | } |