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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 | |
3ffd4af2 LP |
13 | #include "clock-util.h" |
14 | #include "fd-util.h" | |
bbc98d32 | 15 | #include "macro.h" |
07630cea | 16 | #include "string-util.h" |
9c4615fb | 17 | #include "util.h" |
bbc98d32 | 18 | |
60989612 | 19 | int clock_get_hwclock(struct tm *tm) { |
8e64fd11 | 20 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
21 | |
22 | assert(tm); | |
23 | ||
67fb4482 | 24 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
25 | if (fd < 0) |
26 | return -errno; | |
27 | ||
28 | /* This leaves the timezone fields of struct tm | |
29 | * uninitialized! */ | |
30 | if (ioctl(fd, RTC_RD_TIME, tm) < 0) | |
8e64fd11 | 31 | return -errno; |
bbc98d32 KS |
32 | |
33 | /* We don't know daylight saving, so we reset this in order not | |
2f6a5907 | 34 | * to confuse mktime(). */ |
bbc98d32 KS |
35 | tm->tm_isdst = -1; |
36 | ||
8e64fd11 | 37 | return 0; |
bbc98d32 KS |
38 | } |
39 | ||
60989612 | 40 | int clock_set_hwclock(const struct tm *tm) { |
8e64fd11 | 41 | _cleanup_close_ int fd = -1; |
bbc98d32 KS |
42 | |
43 | assert(tm); | |
44 | ||
67fb4482 | 45 | fd = open("/dev/rtc", O_RDONLY|O_CLOEXEC); |
bbc98d32 KS |
46 | if (fd < 0) |
47 | return -errno; | |
48 | ||
49 | if (ioctl(fd, RTC_SET_TIME, tm) < 0) | |
8e64fd11 | 50 | return -errno; |
bbc98d32 | 51 | |
8e64fd11 | 52 | return 0; |
bbc98d32 | 53 | } |
a866073d | 54 | |
6369641d | 55 | int clock_is_localtime(const char* adjtime_path) { |
7fd1b19b | 56 | _cleanup_fclose_ FILE *f; |
bbc98d32 | 57 | |
234519ae | 58 | if (!adjtime_path) |
6369641d MP |
59 | adjtime_path = "/etc/adjtime"; |
60 | ||
bbc98d32 KS |
61 | /* |
62 | * The third line of adjtime is "UTC" or "LOCAL" or nothing. | |
63 | * # /etc/adjtime | |
64 | * 0.0 0 0 | |
65 | * 0 | |
66 | * UTC | |
67 | */ | |
6369641d | 68 | f = fopen(adjtime_path, "re"); |
bbc98d32 KS |
69 | if (f) { |
70 | char line[LINE_MAX]; | |
71 | bool b; | |
72 | ||
73 | b = fgets(line, sizeof(line), f) && | |
74 | fgets(line, sizeof(line), f) && | |
75 | fgets(line, sizeof(line), f); | |
bbc98d32 | 76 | if (!b) |
35f7216f MP |
77 | /* less than three lines -> default to UTC */ |
78 | return 0; | |
bbc98d32 KS |
79 | |
80 | truncate_nl(line); | |
8e2f9ebf | 81 | return streq(line, "LOCAL"); |
bbc98d32 | 82 | |
bcb161b0 | 83 | } else if (errno != ENOENT) |
bbc98d32 KS |
84 | return -errno; |
85 | ||
35f7216f | 86 | /* adjtime not present -> default to UTC */ |
8e2f9ebf | 87 | return 0; |
bbc98d32 KS |
88 | } |
89 | ||
24efb112 | 90 | int clock_set_timezone(int *min) { |
bbc98d32 KS |
91 | const struct timeval *tv_null = NULL; |
92 | struct timespec ts; | |
93 | struct tm *tm; | |
19e65613 | 94 | int minutesdelta; |
bbc98d32 KS |
95 | struct timezone tz; |
96 | ||
97 | assert_se(clock_gettime(CLOCK_REALTIME, &ts) == 0); | |
98 | assert_se(tm = localtime(&ts.tv_sec)); | |
19e65613 | 99 | minutesdelta = tm->tm_gmtoff / 60; |
bbc98d32 | 100 | |
19e65613 | 101 | tz.tz_minuteswest = -minutesdelta; |
cc13b327 | 102 | tz.tz_dsttime = 0; /* DST_NONE */ |
bbc98d32 KS |
103 | |
104 | /* | |
c264aeab KS |
105 | * If the RTC does not run in UTC but in local time, the very first |
106 | * call to settimeofday() will set the kernel's timezone and will warp the | |
107 | * system clock, so that it runs in UTC instead of the local time we | |
108 | * have read from the RTC. | |
bbc98d32 KS |
109 | */ |
110 | if (settimeofday(tv_null, &tz) < 0) | |
9c4615fb ZJS |
111 | return negative_errno(); |
112 | ||
bbc98d32 | 113 | if (min) |
19e65613 | 114 | *min = minutesdelta; |
bbc98d32 KS |
115 | return 0; |
116 | } | |
117 | ||
c264aeab | 118 | int clock_reset_timewarp(void) { |
bbc98d32 KS |
119 | const struct timeval *tv_null = NULL; |
120 | struct timezone tz; | |
121 | ||
122 | tz.tz_minuteswest = 0; | |
cc13b327 | 123 | tz.tz_dsttime = 0; /* DST_NONE */ |
bbc98d32 | 124 | |
72edcff5 | 125 | /* |
c264aeab KS |
126 | * The very first call to settimeofday() does time warp magic. Do a |
127 | * dummy call here, so the time warping is sealed and all later calls | |
128 | * behave as expected. | |
72edcff5 | 129 | */ |
bbc98d32 KS |
130 | if (settimeofday(tv_null, &tz) < 0) |
131 | return -errno; | |
132 | ||
133 | return 0; | |
134 | } | |
021dd87b LP |
135 | |
136 | #define TIME_EPOCH_USEC ((usec_t) TIME_EPOCH * USEC_PER_SEC) | |
137 | ||
138 | int clock_apply_epoch(void) { | |
139 | struct timespec ts; | |
140 | ||
141 | if (now(CLOCK_REALTIME) >= TIME_EPOCH_USEC) | |
142 | return 0; | |
143 | ||
144 | if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, TIME_EPOCH_USEC)) < 0) | |
145 | return -errno; | |
146 | ||
147 | return 1; | |
148 | } |