reactos/ntoskrnl/rtl/capture.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/rtl/capture.c
   6  * PURPOSE:         Helper routines for system calls.
   7  *
   8  * PROGRAMMERS:     David Welch (welch@cwcom.net)
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* FUNCTIONS *****************************************************************/
  18
  19 NTSTATUS
  20 RtlCaptureUnicodeString(OUT PUNICODE_STRING Dest,
  21                         IN KPROCESSOR_MODE CurrentMode,
  22                         IN POOL_TYPE PoolType,
  23                         IN BOOLEAN CaptureIfKernel,
  24                         IN PUNICODE_STRING UnsafeSrc)
  25 {
  26   UNICODE_STRING Src;
  27   NTSTATUS Status = STATUS_SUCCESS;
  28
  29   ASSERT(Dest != NULL);
  30
  31   /*
  32    * Copy the source string structure to kernel space.
  33    */
  34
  35   if(CurrentMode == UserMode)
  36   {
  37     RtlZeroMemory(&Src, sizeof(Src));
  38
  39     _SEH_TRY
  40     {
  41       ProbeForRead(UnsafeSrc,
  42                    sizeof(UNICODE_STRING),
  43                    sizeof(ULONG));
  44       Src = *UnsafeSrc;
  45       if(Src.Length > 0)
  46       {
  47         ProbeForRead(Src.Buffer,
  48                      Src.Length,
  49                      sizeof(WCHAR));
  50       }
  51     }
  52     _SEH_HANDLE
  53     {
  54       Status = _SEH_GetExceptionCode();
  55     }
  56     _SEH_END;
  57
  58     if(!NT_SUCCESS(Status))
  59     {
  60       return Status;
  61     }
  62   }
  63   else if(!CaptureIfKernel)
  64   {
  65     /* just copy the UNICODE_STRING structure, the pointers are considered valid */
  66     *Dest = *UnsafeSrc;
  67     return STATUS_SUCCESS;
  68   }
  69   else
  70   {
  71     /* capture the string even though it is considered to be valid */
  72     Src = *UnsafeSrc;
  73   }
  74
  75   /*
  76    * Initialize the destination string.
  77    */
  78   Dest->Length = Src.Length;
  79   if(Src.Length > 0)
  80   {
  81     Dest->MaximumLength = Src.Length + sizeof(WCHAR);
  82     Dest->Buffer = ExAllocatePool(PoolType, Dest->MaximumLength);
  83     if (Dest->Buffer == NULL)
  84     {
  85       Dest->Length = Dest->MaximumLength = 0;
  86       Dest->Buffer = NULL;
  87       return STATUS_INSUFFICIENT_RESOURCES;
  88     }
  89     /*
  90      * Copy the source string to kernel space.
  91      */
  92     _SEH_TRY
  93     {
  94       RtlCopyMemory(Dest->Buffer, Src.Buffer, Src.Length);
  95       Dest->Buffer[Src.Length / sizeof(WCHAR)] = L'\0';
  96     }
  97     _SEH_HANDLE
  98     {
  99       Status = _SEH_GetExceptionCode();
 100     }
 101     _SEH_END;
 102
 103     if(!NT_SUCCESS(Status))
 104     {
 105       ExFreePool(Dest->Buffer);
 106       Dest->Buffer = NULL;
 107       Dest->Length = Dest->MaximumLength = 0;
 108     }
 109   }
 110   else
 111   {
 112     Dest->MaximumLength = 0;
 113     Dest->Buffer = NULL;
 114   }
 115
 116   return Status;
 117 }
 118
 119 VOID
 120 RtlReleaseCapturedUnicodeString(IN PUNICODE_STRING CapturedString,
 121                                 IN KPROCESSOR_MODE CurrentMode,
 122                                 IN BOOLEAN CaptureIfKernel)
 123 {
 124   if(CurrentMode != KernelMode || CaptureIfKernel )
 125   {
 126     RtlFreeUnicodeString(CapturedString);
 127   }
 128 }
 129
 130 /*
 131  * @unimplemented
 132  */
 133 VOID
 134 STDCALL
 135 RtlCaptureContext (
 136         OUT PCONTEXT ContextRecord
 137         )
 138 {
 139         UNIMPLEMENTED;
 140 }
 141
 142 /*
 143 * @unimplemented
 144 */
 145 USHORT
 146 STDCALL
 147 RtlCaptureStackBackTrace (
 148         IN ULONG FramesToSkip,
 149         IN ULONG FramesToCapture,
 150         OUT PVOID *BackTrace,
 151         OUT PULONG BackTraceHash OPTIONAL
 152         )
 153 {
 154         UNIMPLEMENTED;
 155         return 0;
 156 }
 157
 158 /* EOF */
 159