1 files changed, 213 insertions, 0 deletions

diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
new file mode 100644
index 000000000..8fcd8c99c
--- /dev/null
+++ b/util-linux/hwclock.c
@@ -0,0 +1,213 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini hwclock implementation for busybox
+ *
+ * Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+*/
+
+
+#include <sys/ioctl.h>
+#include <sys/utsname.h>
+#include <getopt.h>
+#include "busybox.h"
+
+/* Copied from linux/rtc.h to eliminate the kernel dependency */
+struct linux_rtc_time {
+        int tm_sec;
+        int tm_min;
+        int tm_hour;
+        int tm_mday;
+        int tm_mon;
+        int tm_year;
+        int tm_wday;
+        int tm_yday;
+        int tm_isdst;
+};
+
+#define RTC_SET_TIME   _IOW('p', 0x0a, struct linux_rtc_time) /* Set RTC time    */
+#define RTC_RD_TIME    _IOR('p', 0x09, struct linux_rtc_time) /* Read RTC time   */
+
+#if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
+# ifndef _GNU_SOURCE
+#  define _GNU_SOURCE
+# endif
+#endif
+
+static int xopen_rtc(int flags)
+{
+        int rtc;
+        rtc = open("/dev/rtc", flags);
+        if (rtc < 0) {
+                rtc = open("/dev/misc/rtc", flags);
+                if (rtc < 0)
+                        bb_perror_msg_and_die("cannot access RTC");
+        }
+        return rtc;
+}
+
+static time_t read_rtc(int utc)
+{
+        struct tm tm;
+        char *oldtz = 0;
+        time_t t = 0;
+        int rtc = xopen_rtc(O_RDONLY);
+
+        memset(&tm, 0, sizeof(struct tm));
+        if (ioctl(rtc, RTC_RD_TIME, &tm) < 0 )
+                bb_perror_msg_and_die("cannot read time from RTC");
+        tm.tm_isdst = -1; /* not known */
+
+        close(rtc);
+
+        if (utc) {
+                oldtz = getenv("TZ");
+                setenv("TZ", "UTC 0", 1);
+                tzset();
+        }
+
+        t = mktime(&tm);
+
+        if (utc) {
+                if (oldtz)
+                        setenv("TZ", oldtz, 1);
+                else
+                        unsetenv("TZ");
+                tzset();
+        }
+        return t;
+}
+
+static void write_rtc(time_t t, int utc)
+{
+        struct tm tm;
+        int rtc = xopen_rtc(O_WRONLY);
+
+        tm = *(utc ? gmtime(&t) : localtime(&t));
+        tm.tm_isdst = 0;
+
+        if (ioctl(rtc, RTC_SET_TIME, &tm) < 0)
+                bb_perror_msg_and_die("cannot set the RTC time");
+
+        close(rtc);
+}
+
+static int show_clock(int utc)
+{
+        struct tm *ptm;
+        time_t t;
+        RESERVE_CONFIG_BUFFER(buffer, 64);
+
+        t = read_rtc(utc);
+        ptm = localtime(&t);  /* Sets 'tzname[]' */
+
+        safe_strncpy(buffer, ctime(&t), 64);
+        if (buffer[0])
+                buffer[strlen(buffer) - 1] = 0;
+
+        //printf("%s  %.6f seconds %s\n", buffer, 0.0, utc ? "" : (ptm->tm_isdst ? tzname[1] : tzname[0]));
+        printf( "%s  %.6f seconds\n", buffer, 0.0);
+        RELEASE_CONFIG_BUFFER(buffer);
+
+        return 0;
+}
+
+static int to_sys_clock(int utc)
+{
+        struct timeval tv = { 0, 0 };
+        const struct timezone tz = { timezone/60 - 60*daylight, 0 };
+
+        tv.tv_sec = read_rtc(utc);
+
+        if (settimeofday(&tv, &tz))
+                bb_perror_msg_and_die("settimeofday() failed");
+
+        return 0;
+}
+
+static int from_sys_clock(int utc)
+{
+        struct timeval tv = { 0, 0 };
+        struct timezone tz = { 0, 0 };
+
+        if (gettimeofday(&tv, &tz))
+                bb_perror_msg_and_die("gettimeofday() failed");
+
+        write_rtc(tv.tv_sec, utc);
+        return 0;
+}
+
+#ifdef CONFIG_FEATURE_HWCLOCK_ADJTIME_FHS
+# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
+#else
+# define ADJTIME_PATH "/etc/adjtime"
+#endif
+static int check_utc(void)
+{
+        int utc = 0;
+        FILE *f = fopen(ADJTIME_PATH, "r");
+
+        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;
+}
+
+#define HWCLOCK_OPT_LOCALTIME   0x01
+#define HWCLOCK_OPT_UTC         0x02
+#define HWCLOCK_OPT_SHOW        0x04
+#define HWCLOCK_OPT_HCTOSYS     0x08
+#define HWCLOCK_OPT_SYSTOHC     0x10
+
+int hwclock_main(int argc, char **argv )
+{
+        unsigned opt;
+        int utc;
+
+#if ENABLE_FEATURE_HWCLOCK_LONG_OPTIONS
+        static const struct option hwclock_long_options[] = {
+                { "localtime", 0, 0, 'l' },
+                { "utc",       0, 0, 'u' },
+                { "show",      0, 0, 'r' },
+                { "hctosys",   0, 0, 's' },
+                { "systohc",   0, 0, 'w' },
+                { 0,           0, 0, 0 }
+        };
+        applet_long_options = hwclock_long_options;
+#endif
+        opt_complementary = "?:r--ws:w--rs:s--wr:l--u:u--l";
+        opt = getopt32(argc, argv, "lursw");
+
+        /* If -u or -l wasn't given check if we are using utc */
+        if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
+                utc = opt & HWCLOCK_OPT_UTC;
+        else
+                utc = check_utc();
+
+        if (opt & HWCLOCK_OPT_HCTOSYS) {
+                return to_sys_clock(utc);
+        }
+        else if (opt & HWCLOCK_OPT_SYSTOHC) {
+                return from_sys_clock(utc);
+        } else {
+                /* default HWCLOCK_OPT_SHOW */
+                return show_clock(utc);
+        }
+}