date: allow system date to be set

Implement clock_settime(2) and enable the '-s' option to allow
the system time to be set.  This requires elevated privileges.

The code in date.c is now identical to upstream BusyBox.

Costs 256-272 bytes.

1 files changed, 23 insertions, 0 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index 86dc75861..5e9c71226 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1008,6 +1008,29 @@ int clock_gettime(clockid_t clockid, struct timespec *tp)
         return 0;
 }
 
+int clock_settime(clockid_t clockid, const struct timespec *tp)
+{
+        SYSTEMTIME st;
+        FILETIME ft;
+
+        if (clockid != CLOCK_REALTIME) {
+                errno = ENOSYS;
+                return -1;
+        }
+
+        timespec_to_filetime(*tp, &ft);
+        if (FileTimeToSystemTime(&ft, &st) == 0) {
+                errno = EINVAL;
+                return -1;
+        }
+
+        if (SetSystemTime(&st) == 0) {
+                errno = EPERM;
+                return -1;
+        }
+        return 0;
+}
+
 int pipe(int filedes[2])
 {
         if (_pipe(filedes, PIPE_BUF, 0) < 0)