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Commit | Line | Data |
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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
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 | 14 | #include "clock-util.h" |
2b2fec7d | 15 | #include "errno-util.h" |
3ffd4af2 | 16 | #include "fd-util.h" |
6d3db278 | 17 | #include "fileio.h" |
bbc98d32 | 18 | #include "macro.h" |
07630cea | 19 | #include "string-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 | ||
505061bb | 99 | int clock_set_timezone(int *ret_minutesdelta) { |
bbc98d32 | 100 | struct timespec ts; |
e0f691e1 | 101 | struct tm tm; |
19e65613 | 102 | int minutesdelta; |
bbc98d32 KS |
103 | struct timezone tz; |
104 | ||
105 | assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0); | |
e0f691e1 YW |
106 | assert_se(localtime_r(&ts.tv_sec, &tm)); |
107 | minutesdelta = tm.tm_gmtoff / 60; | |
bbc98d32 | 108 | |
505061bb LP |
109 | tz = (struct timezone) { |
110 | .tz_minuteswest = -minutesdelta, | |
111 | .tz_dsttime = 0, /* DST_NONE */ | |
112 | }; | |
bbc98d32 | 113 | |
505061bb LP |
114 | /* If the RTC does not run in UTC but in local time, the very first call to settimeofday() will set |
115 | * the kernel's timezone and will warp the system clock, so that it runs in UTC instead of the local | |
116 | * time we have read from the RTC. */ | |
117 | if (settimeofday(NULL, &tz) < 0) | |
118 | return -errno; | |
119 | ||
120 | if (ret_minutesdelta) | |
121 | *ret_minutesdelta = minutesdelta; | |
9c4615fb | 122 | |
bbc98d32 KS |
123 | return 0; |
124 | } | |
125 | ||
c264aeab | 126 | int clock_reset_timewarp(void) { |
505061bb LP |
127 | static const struct timezone tz = { |
128 | .tz_minuteswest = 0, | |
129 | .tz_dsttime = 0, /* DST_NONE */ | |
130 | }; | |
131 | ||
132 | /* The very first call to settimeofday() does time warp magic. Do a dummy call here, so the time | |
133 | * warping is sealed and all later calls behave as expected. */ | |
134 | if (settimeofday(NULL, &tz) < 0) | |
bbc98d32 KS |
135 | return -errno; |
136 | ||
137 | return 0; | |
138 | } | |
021dd87b | 139 | |
5170afbc | 140 | #define EPOCH_FILE "/usr/lib/clock-epoch" |
021dd87b LP |
141 | |
142 | int clock_apply_epoch(void) { | |
5170afbc | 143 | struct stat st; |
021dd87b | 144 | struct timespec ts; |
5170afbc | 145 | usec_t epoch_usec; |
021dd87b | 146 | |
5170afbc DM |
147 | if (stat(EPOCH_FILE, &st) < 0) { |
148 | if (errno != ENOENT) | |
0d18259e | 149 | log_warning_errno(errno, "Cannot stat " EPOCH_FILE ": %m"); |
5170afbc | 150 | |
0d18259e | 151 | epoch_usec = (usec_t) TIME_EPOCH * USEC_PER_SEC; |
5170afbc DM |
152 | } else |
153 | epoch_usec = timespec_load(&st.st_mtim); | |
154 | ||
155 | if (now(CLOCK_REALTIME) >= epoch_usec) | |
021dd87b LP |
156 | return 0; |
157 | ||
5170afbc | 158 | if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, epoch_usec)) < 0) |
021dd87b LP |
159 | return -errno; |
160 | ||
161 | return 1; | |
162 | } |