busybox/libbb/rtc.c

/*
 * Common RTC functions
 */

#include "libbb.h"
#include "rtc_.h"

#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
#else
# define ADJTIME_PATH "/etc/adjtime"
#endif

int FAST_FUNC rtc_adjtime_is_utc(void)
{
	int utc = 0;
	FILE *f = fopen_for_read(ADJTIME_PATH);

	if (f) {
		RESERVE_CONFIG_BUFFER(buffer, 128);

		while (fgets(buffer, sizeof(buffer), f)) {
			int len = strlen(buffer);

			while (len && isspace(buffer[len - 1]))
				len--;

			buffer[len] = 0;

			if (strncmp(buffer, "UTC", 3) == 0) {
				utc = 1;
				break;
			}
		}
		fclose(f);

		RELEASE_CONFIG_BUFFER(buffer);
	}

	return utc;
}

int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
{
	int rtc;

	if (!*default_rtc) {
		*default_rtc = "/dev/rtc";
		rtc = open(*default_rtc, flags);
		if (rtc >= 0)
			return rtc;
		*default_rtc = "/dev/rtc0";
		rtc = open(*default_rtc, flags);
		if (rtc >= 0)
			return rtc;
		*default_rtc = "/dev/misc/rtc";
	}

	return xopen(*default_rtc, flags);
}

time_t FAST_FUNC rtc_read_time(int fd, int utc)
{
	struct tm tm;
	char *oldtz = 0;
	time_t t = 0;

	memset(&tm, 0, sizeof(struct tm));
	xioctl(fd, RTC_RD_TIME, &tm);
	tm.tm_isdst = -1; /* not known */

	if (utc) {
		oldtz = getenv("TZ");
		putenv((char*)"TZ=UTC0");
		tzset();
	}

	t = mktime(&tm);

	if (utc) {
		unsetenv("TZ");
		if (oldtz)
			putenv(oldtz - 3);
		tzset();
	}

	return t;
}
1	/*
2	* Common RTC functions
3	*/
4
5	#include "libbb.h"
6	#include "rtc_.h"
7
8	#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
9	# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
10	#else
11	# define ADJTIME_PATH "/etc/adjtime"
12	#endif
13
14	int FAST_FUNC rtc_adjtime_is_utc(void)
15	{
16	int utc = 0;
17	FILE *f = fopen_for_read(ADJTIME_PATH);
18
19	if (f) {
20	RESERVE_CONFIG_BUFFER(buffer, 128);
21
22	while (fgets(buffer, sizeof(buffer), f)) {
23	int len = strlen(buffer);
24
25	while (len && isspace(buffer[len - 1]))
26	len--;
27
28	buffer[len] = 0;
29
30	if (strncmp(buffer, "UTC", 3) == 0) {
31	utc = 1;
32	break;
33	}
34	}
35	fclose(f);
36
37	RELEASE_CONFIG_BUFFER(buffer);
38	}
39
40	return utc;
41	}
42
43	int FAST_FUNC rtc_xopen(const char **default_rtc, int flags)
44	{
45	int rtc;
46
47	if (!*default_rtc) {
48	*default_rtc = "/dev/rtc";
49	rtc = open(*default_rtc, flags);
50	if (rtc >= 0)
51	return rtc;
52	*default_rtc = "/dev/rtc0";
53	rtc = open(*default_rtc, flags);
54	if (rtc >= 0)
55	return rtc;
56	*default_rtc = "/dev/misc/rtc";
57	}
58
59	return xopen(*default_rtc, flags);
60	}
61
62	time_t FAST_FUNC rtc_read_time(int fd, int utc)
63	{
64	struct tm tm;
65	char *oldtz = 0;
66	time_t t = 0;
67
68	memset(&tm, 0, sizeof(struct tm));
69	xioctl(fd, RTC_RD_TIME, &tm);
70	tm.tm_isdst = -1; /* not known */
71
72	if (utc) {
73	oldtz = getenv("TZ");
74	putenv((char*)"TZ=UTC0");
75	tzset();
76	}
77
78	t = mktime(&tm);
79
80	if (utc) {
81	unsetenv("TZ");
82	if (oldtz)
83	putenv(oldtz - 3);
84	tzset();
85	}
86
87	return t;
88	}