reactos/ntoskrnl/ex/time.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS Kernel
   4  * FILE:            ntoskrnl/ex/time.c
   5  * PURPOSE:         Time and Timezone Management
   6  * PROGRAMMERS:     Eric Kohl
   7  *                  Thomas Weidenmueller
   8  */
   9
  10 /* INCLUDES *****************************************************************/
  11
  12 #include <ntoskrnl.h>
  13 #define NDEBUG
  14 #include <internal/debug.h>
  15
  16 #define TICKSPERMINUTE  600000000
  17
  18 #if defined (ALLOC_PRAGMA)
  19 #pragma alloc_text(INIT, ExpInitTimeZoneInfo)
  20 #endif
  21
  22 /* GLOBALS ******************************************************************/
  23
  24 /* Note: Bias[minutes] = UTC - local time */
  25 TIME_ZONE_INFORMATION ExpTimeZoneInfo;
  26 LARGE_INTEGER ExpTimeZoneBias;
  27 ULONG ExpTimeZoneId;
  28
  29 /* FUNCTIONS ****************************************************************/
  30
  31 VOID
  32 INIT_FUNCTION
  33 NTAPI
  34 ExpInitTimeZoneInfo(VOID)
  35 {
  36     LARGE_INTEGER CurrentTime;
  37     NTSTATUS Status;
  38
  39      /* Read time zone information from the registry */
  40     Status = RtlQueryTimeZoneInformation(&ExpTimeZoneInfo);
  41     if (!NT_SUCCESS(Status))
  42     {
  43         /* Failed, clear all data */
  44         RtlZeroMemory(&ExpTimeZoneInfo, sizeof(TIME_ZONE_INFORMATION));
  45         ExpTimeZoneBias.QuadPart = (LONGLONG)0;
  46         ExpTimeZoneId = TIME_ZONE_ID_UNKNOWN;
  47     }
  48     else
  49     {
  50         /* FIXME: Calculate transition dates */
  51
  52         /* Set bias and ID */
  53         ExpTimeZoneBias.QuadPart = ((LONGLONG)(ExpTimeZoneInfo.Bias +
  54                                                ExpTimeZoneInfo.StandardBias)) *
  55                                                TICKSPERMINUTE;
  56         ExpTimeZoneId = TIME_ZONE_ID_STANDARD;
  57     }
  58
  59     /* Change it for user-mode applications */
  60     SharedUserData->TimeZoneBias.High1Time = ExpTimeZoneBias.u.HighPart;
  61     SharedUserData->TimeZoneBias.High2Time = ExpTimeZoneBias.u.HighPart;
  62     SharedUserData->TimeZoneBias.LowPart = ExpTimeZoneBias.u.LowPart;
  63     SharedUserData->TimeZoneId = ExpTimeZoneId;
  64
  65     /* Convert boot time from local time to UTC */
  66     SystemBootTime.QuadPart += ExpTimeZoneBias.QuadPart;
  67
  68     /* Convert system time from local time to UTC */
  69     do
  70     {
  71         CurrentTime.u.HighPart = SharedUserData->SystemTime.High1Time;
  72         CurrentTime.u.LowPart = SharedUserData->SystemTime.LowPart;
  73     } while (CurrentTime.u.HighPart != SharedUserData->SystemTime.High2Time);
  74
  75     /* Change it for user-mode applications */
  76     CurrentTime.QuadPart += ExpTimeZoneBias.QuadPart;
  77     SharedUserData->SystemTime.LowPart = CurrentTime.u.LowPart;
  78     SharedUserData->SystemTime.High1Time = CurrentTime.u.HighPart;
  79     SharedUserData->SystemTime.High2Time = CurrentTime.u.HighPart;
  80 }
  81
  82 NTSTATUS
  83 ExpSetTimeZoneInformation(PTIME_ZONE_INFORMATION TimeZoneInformation)
  84 {
  85     LARGE_INTEGER LocalTime, SystemTime;
  86     TIME_FIELDS TimeFields;
  87     DPRINT("ExpSetTimeZoneInformation() called\n");
  88
  89     DPRINT("Old time zone bias: %d minutes\n", ExpTimeZoneInfo.Bias);
  90     DPRINT("Old time zone standard bias: %d minutes\n",
  91             ExpTimeZoneInfo.StandardBias);
  92     DPRINT("New time zone bias: %d minutes\n", TimeZoneInformation->Bias);
  93     DPRINT("New time zone standard bias: %d minutes\n",
  94             TimeZoneInformation->StandardBias);
  95
  96     /* Get the local time */
  97     HalQueryRealTimeClock(&TimeFields);
  98     RtlTimeFieldsToTime(&TimeFields, &LocalTime);
  99
 100     /* FIXME: Calculate transition dates */
 101
 102     /* Calculate the bias and set the ID */
 103     ExpTimeZoneBias.QuadPart = ((LONGLONG)(TimeZoneInformation->Bias +
 104                                            TimeZoneInformation->StandardBias)) *
 105                                            TICKSPERMINUTE;
 106     ExpTimeZoneId = TIME_ZONE_ID_STANDARD;
 107
 108     /* Copy the timezone information */
 109     RtlMoveMemory(&ExpTimeZoneInfo,
 110                   TimeZoneInformation,
 111                   sizeof(TIME_ZONE_INFORMATION));
 112
 113     /* Set the new time zone information */
 114     SharedUserData->TimeZoneBias.High1Time = ExpTimeZoneBias.u.HighPart;
 115     SharedUserData->TimeZoneBias.High2Time = ExpTimeZoneBias.u.HighPart;
 116     SharedUserData->TimeZoneBias.LowPart = ExpTimeZoneBias.u.LowPart;
 117     SharedUserData->TimeZoneId = ExpTimeZoneId;
 118
 119     DPRINT("New time zone bias: %I64d minutes\n",
 120             ExpTimeZoneBias.QuadPart / TICKSPERMINUTE);
 121
 122     /* Calculate the new system time */
 123     ExLocalTimeToSystemTime(&LocalTime, &SystemTime);
 124
 125     /* Set the new system time */
 126     KiSetSystemTime(&SystemTime);
 127
 128     /* Return success */
 129     DPRINT("ExpSetTimeZoneInformation() done\n");
 130     return STATUS_SUCCESS;
 131 }
 132
 133 /*
 134  * FUNCTION: Sets the system time.
 135  * PARAMETERS:
 136  *        NewTime - Points to a variable that specified the new time
 137  *        of day in the standard time format.
 138  *        OldTime - Optionally points to a variable that receives the
 139  *        old time of day in the standard time format.
 140  * RETURNS: Status
 141  */
 142 NTSTATUS
 143 NTAPI
 144 NtSetSystemTime(IN PLARGE_INTEGER SystemTime,
 145                 OUT PLARGE_INTEGER PreviousTime OPTIONAL)
 146 {
 147     LARGE_INTEGER OldSystemTime;
 148     LARGE_INTEGER NewSystemTime;
 149     LARGE_INTEGER LocalTime;
 150     TIME_FIELDS TimeFields;
 151     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
 152     NTSTATUS Status = STATUS_SUCCESS;
 153     PAGED_CODE();
 154
 155     /* Check if we were called from user-mode */
 156     if(PreviousMode != KernelMode)
 157     {
 158         _SEH_TRY
 159         {
 160             /* Verify the time pointers */
 161             NewSystemTime = ProbeForReadLargeInteger(SystemTime);
 162             if(PreviousTime) ProbeForWriteLargeInteger(PreviousTime);
 163         }
 164         _SEH_EXCEPT(_SEH_ExSystemExceptionFilter)
 165         {
 166             Status = _SEH_GetExceptionCode();
 167         }
 168         _SEH_END;
 169
 170         /* If the pointers were invalid, bail out */
 171         if(!NT_SUCCESS(Status)) return Status;
 172     }
 173     else
 174     {
 175         /* Reuse the pointer */
 176         NewSystemTime = *SystemTime;
 177     }
 178
 179     /* Make sure we have permission to change the time */
 180     if(!SeSinglePrivilegeCheck(SeSystemtimePrivilege, PreviousMode))
 181     {
 182         DPRINT1("NtSetSystemTime: Caller requires the "
 183                 "SeSystemtimePrivilege privilege!\n");
 184         return STATUS_PRIVILEGE_NOT_HELD;
 185     }
 186
 187     /* Check if caller wants the old time */
 188     if(PreviousTime) KeQuerySystemTime(&OldSystemTime);
 189
 190     /* Convert the time and set it in HAL */
 191     ExSystemTimeToLocalTime(&NewSystemTime, &LocalTime);
 192     RtlTimeToTimeFields(&LocalTime, &TimeFields);
 193     HalSetRealTimeClock(&TimeFields);
 194
 195     /* Now set system time */
 196     KiSetSystemTime(&NewSystemTime);
 197
 198     /* Check if caller wanted previous time */
 199     if(PreviousTime)
 200     {
 201         /* Enter SEH Block for return */
 202         _SEH_TRY
 203         {
 204             /* Return the previous time */
 205             *PreviousTime = OldSystemTime;
 206         }
 207         _SEH_EXCEPT(_SEH_ExSystemExceptionFilter)
 208         {
 209             Status = _SEH_GetExceptionCode();
 210         }
 211         _SEH_END;
 212     }
 213
 214     /* Return status */
 215     return Status;
 216 }
 217
 218 /*
 219  * FUNCTION: Retrieves the system time.
 220  * PARAMETERS:
 221  *          CurrentTime - Points to a variable that receives the current
 222  *          time of day in the standard time format.
 223  */
 224 NTSTATUS
 225 NTAPI
 226 NtQuerySystemTime(OUT PLARGE_INTEGER SystemTime)
 227 {
 228     KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
 229     NTSTATUS Status = STATUS_SUCCESS;
 230     PAGED_CODE();
 231
 232     /* Check if we were called from user-mode */
 233     if(PreviousMode != KernelMode)
 234     {
 235         _SEH_TRY
 236         {
 237             /* Verify the time pointer */
 238             ProbeForWriteLargeInteger(SystemTime);
 239
 240             /*
 241              * It's safe to pass the pointer directly to KeQuerySystemTime as
 242              * it's just a basic copy to this pointer. If it raises an
 243              * exception nothing dangerous can happen!
 244              */
 245             KeQuerySystemTime(SystemTime);
 246         }
 247         _SEH_EXCEPT(_SEH_ExSystemExceptionFilter)
 248         {
 249         Status = _SEH_GetExceptionCode();
 250         }
 251         _SEH_END;
 252     }
 253     else
 254     {
 255         /* Query the time directly */
 256         KeQuerySystemTime(SystemTime);
 257     }
 258
 259     /* Return status to caller */
 260     return Status;
 261 }
 262
 263 /*
 264  * @implemented
 265  */
 266 VOID
 267 NTAPI
 268 ExLocalTimeToSystemTime(PLARGE_INTEGER LocalTime,
 269                         PLARGE_INTEGER SystemTime)
 270 {
 271     SystemTime->QuadPart = LocalTime->QuadPart + ExpTimeZoneBias.QuadPart;
 272 }
 273
 274 /*
 275  * @unimplemented
 276  */
 277 ULONG
 278 NTAPI
 279 ExSetTimerResolution(IN ULONG DesiredTime,
 280                      IN BOOLEAN SetResolution)
 281 {
 282     UNIMPLEMENTED;
 283     return 0;
 284 }
 285
 286 /*
 287  * @implemented
 288  */
 289 VOID
 290 NTAPI
 291 ExSystemTimeToLocalTime(PLARGE_INTEGER SystemTime,
 292                         PLARGE_INTEGER LocalTime)
 293 {
 294     LocalTime->QuadPart = SystemTime->QuadPart - ExpTimeZoneBias.QuadPart;
 295 }
 296
 297 /* EOF */