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   TIME_FIELDS TimeFields;
  61
  62   /* FIXME: Check for SeSystemTimePrivilege */
  63
  64   Status = MmCopyFromCaller(&NewSystemTime, UnsafeNewSystemTime,
  65                             sizeof(NewSystemTime));
  66   if (!NT_SUCCESS(Status))
  67     {
  68       return(Status);
  69     }
  70
  71   if (UnsafeOldSystemTime != NULL)
  72     {
  73       KeQuerySystemTime(&OldSystemTime);
  74     }
  75   RtlTimeToTimeFields (&NewSystemTime, &TimeFields);
  76   HalSetRealTimeClock (&TimeFields);
  77
  78   if (UnsafeOldSystemTime != NULL)
  79     {
  80       Status = MmCopyToCaller(UnsafeOldSystemTime, &OldSystemTime,
  81                               sizeof(OldSystemTime));
  82       if (!NT_SUCCESS(Status))
  83         {
  84           return(Status);
  85         }
  86     }
  87   return(STATUS_SUCCESS);
  88 }
  89
  90
  91 NTSTATUS STDCALL
  92 NtQuerySystemTime (OUT TIME* UnsafeCurrentTime)
  93      /*
  94       * FUNCTION: Retrieves the system time.
  95       * PARAMETERS:
  96       *          CurrentTime - Points to a variable that receives the current
  97       *          time of day in the standard time format.
  98       */
  99 {
 100   LARGE_INTEGER CurrentTime;
 101   NTSTATUS Status;
 102
 103   KeQuerySystemTime(&CurrentTime);
 104   Status = MmCopyToCaller(UnsafeCurrentTime, &CurrentTime,
 105                           sizeof(CurrentTime));
 106   if (!NT_SUCCESS(Status))
 107     {
 108       return(Status);
 109     }
 110   return STATUS_SUCCESS;
 111 }
 112
 113
 114 VOID
 115 STDCALL
 116 ExLocalTimeToSystemTime (
 117         PLARGE_INTEGER  LocalTime,
 118         PLARGE_INTEGER  SystemTime
 119         )
 120 {
 121    SystemTime->QuadPart = LocalTime->QuadPart +
 122                           _SystemTimeZoneInfo.Bias * TICKSPERMINUTE;
 123 }
 124
 125
 126 VOID
 127 STDCALL
 128 ExSystemTimeToLocalTime (
 129         PLARGE_INTEGER  SystemTime,
 130         PLARGE_INTEGER  LocalTime
 131         )
 132 {
 133    LocalTime->QuadPart = SystemTime->QuadPart -
 134                          _SystemTimeZoneInfo.Bias * TICKSPERMINUTE;
 135 }
 136
 137 /* EOF */