ntoskrnl/ex/time.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/ex/time.c
   6  * PURPOSE:         Time
   7  * PROGRAMMER:      David Welch (welch@mcmail.com)
   8  * UPDATE HISTORY:
   9  *                  Created 22/05/98
  10  */
  11
  12 /* INCLUDES *****************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <internal/ex.h>
  16 #include <internal/safe.h>
  17 #include <ddk/halfuncs.h>
  18 #include <ddk/kefuncs.h>
  19
  20 #include <internal/debug.h>
  21
  22
  23 #define TICKSPERMINUTE  600000000
  24
  25 /* GLOBALS ******************************************************************/
  26
  27 /* Note: Bias[minutes] = UTC - local time */
  28 TIME_ZONE_INFORMATION _SystemTimeZoneInfo;
  29
  30
  31 /* FUNCTIONS ****************************************************************/
  32
  33 VOID
  34 ExInitTimeZoneInfo (VOID)
  35 {
  36   /* Initialize system time zone information */
  37   memset (& _SystemTimeZoneInfo, 0, sizeof(TIME_ZONE_INFORMATION));
  38
  39   /* FIXME: Read time zone information from the registry */
  40
  41 }
  42
  43
  44 NTSTATUS STDCALL
  45 NtSetSystemTime (IN     PLARGE_INTEGER  UnsafeNewSystemTime,
  46                  OUT    PLARGE_INTEGER  UnsafeOldSystemTime     OPTIONAL)
  47      /*
  48       * FUNCTION: Sets the system time.
  49       * PARAMETERS:
  50       *        NewTime - Points to a variable that specified the new time
  51       *        of day in the standard time format.
  52       *        OldTime - Optionally points to a variable that receives the
  53       *        old time of day in the standard time format.
  54       * RETURNS: Status
  55       */
  56 {
  57   NTSTATUS Status;
  58   LARGE_INTEGER OldSystemTime;
  59   LARGE_INTEGER NewSystemTime;
  60
  61   /* FIXME: Check for SeSystemTimePrivilege */
  62
  63   Status = MmCopyFromCaller(&NewSystemTime, UnsafeNewSystemTime,
  64                             sizeof(NewSystemTime));
  65   if (!NT_SUCCESS(Status))
  66     {
  67       return(Status);
  68     }
  69
  70   if (UnsafeOldSystemTime != NULL)
  71     {
  72       KeQuerySystemTime(&OldSystemTime);
  73     }
  74   HalSetRealTimeClock ((PTIME_FIELDS)&NewSystemTime);
  75
  76   if (UnsafeOldSystemTime != NULL)
  77     {
  78       Status = MmCopyToCaller(UnsafeOldSystemTime, &OldSystemTime,
  79                               sizeof(OldSystemTime));
  80       if (!NT_SUCCESS(Status))
  81         {
  82           return(Status);
  83         }
  84     }
  85   return(STATUS_SUCCESS);
  86 }
  87
  88
  89 NTSTATUS STDCALL
  90 NtQuerySystemTime (OUT TIME* UnsafeCurrentTime)
  91      /*
  92       * FUNCTION: Retrieves the system time.
  93       * PARAMETERS:
  94       *          CurrentTime - Points to a variable that receives the current
  95       *          time of day in the standard time format.
  96       */
  97 {
  98   LARGE_INTEGER CurrentTime;
  99   NTSTATUS Status;
 100
 101   KeQuerySystemTime(&CurrentTime);
 102   Status = MmCopyToCaller(UnsafeCurrentTime, &CurrentTime,
 103                           sizeof(CurrentTime));
 104   if (!NT_SUCCESS(Status))
 105     {
 106       return(Status);
 107     }
 108   return STATUS_SUCCESS;
 109 }
 110
 111
 112 VOID
 113 STDCALL
 114 ExLocalTimeToSystemTime (
 115         PLARGE_INTEGER  LocalTime,
 116         PLARGE_INTEGER  SystemTime
 117         )
 118 {
 119    SystemTime->QuadPart = LocalTime->QuadPart +
 120                           _SystemTimeZoneInfo.Bias * TICKSPERMINUTE;
 121 }
 122
 123
 124 VOID
 125 STDCALL
 126 ExSystemTimeToLocalTime (
 127         PLARGE_INTEGER  SystemTime,
 128         PLARGE_INTEGER  LocalTime
 129         )
 130 {
 131    LocalTime->QuadPart = SystemTime->QuadPart -
 132                          _SystemTimeZoneInfo.Bias * TICKSPERMINUTE;
 133 }
 134
 135 /* EOF */