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     _SEH_TRY
  38     {
  39       ProbeForRead(UnsafeSrc,
  40                    sizeof(UNICODE_STRING),
  41                    sizeof(ULONG));
  42       Src = *UnsafeSrc;
  43       if(Src.Length > 0)
  44       {
  45         ProbeForRead(Src.Buffer,
  46                      Src.Length,
  47                      sizeof(WCHAR));
  48       }
  49     }
  50     _SEH_HANDLE
  51     {
  52       Status = _SEH_GetExceptionCode();
  53     }
  54     _SEH_END;
  55
  56     if(!NT_SUCCESS(Status))
  57     {
  58       return Status;
  59     }
  60   }
  61   else if(!CaptureIfKernel)
  62   {
  63     /* just copy the UNICODE_STRING structure, the pointers are considered valid */
  64     *Dest = *UnsafeSrc;
  65     return STATUS_SUCCESS;
  66   }
  67   else
  68   {
  69     /* capture the string even though it is considered to be valid */
  70     Src = *UnsafeSrc;
  71   }
  72
  73   /*
  74    * Initialize the destination string.
  75    */
  76   Dest->Length = Src.Length;
  77   if(Src.Length > 0)
  78   {
  79     Dest->MaximumLength = Src.Length + sizeof(WCHAR);
  80     Dest->Buffer = ExAllocatePool(PoolType, Dest->MaximumLength);
  81     if (Dest->Buffer == NULL)
  82     {
  83       Dest->Length = Dest->MaximumLength = 0;
  84       Dest->Buffer = NULL;
  85       return STATUS_INSUFFICIENT_RESOURCES;
  86     }
  87     /*
  88      * Copy the source string to kernel space.
  89      */
  90     _SEH_TRY
  91     {
  92       RtlCopyMemory(Dest->Buffer, Src.Buffer, Src.Length);
  93       Dest->Buffer[Src.Length / sizeof(WCHAR)] = L'\0';
  94     }
  95     _SEH_HANDLE
  96     {
  97       Status = _SEH_GetExceptionCode();
  98     }
  99     _SEH_END;
 100
 101     if(!NT_SUCCESS(Status))
 102     {
 103       ExFreePool(Dest->Buffer);
 104       Dest->Buffer = NULL;
 105       Dest->Length = Dest->MaximumLength = 0;
 106     }
 107   }
 108   else
 109   {
 110     Dest->MaximumLength = 0;
 111     Dest->Buffer = NULL;
 112   }
 113
 114   return Status;
 115 }
 116
 117 VOID
 118 RtlReleaseCapturedUnicodeString(IN PUNICODE_STRING CapturedString,
 119                                 IN KPROCESSOR_MODE CurrentMode,
 120                                 IN BOOLEAN CaptureIfKernel)
 121 {
 122   if(CurrentMode != KernelMode || CaptureIfKernel )
 123   {
 124     RtlFreeUnicodeString(CapturedString);
 125   }
 126 }
 127
 128 /*
 129  * @unimplemented
 130  */
 131 VOID
 132 STDCALL
 133 RtlCaptureContext (
 134         OUT PCONTEXT ContextRecord
 135         )
 136 {
 137         UNIMPLEMENTED;
 138 }
 139
 140 /*
 141 * @unimplemented
 142 */
 143 USHORT
 144 STDCALL
 145 RtlCaptureStackBackTrace (
 146         IN ULONG FramesToSkip,
 147         IN ULONG FramesToCapture,
 148         OUT PVOID *BackTrace,
 149         OUT PULONG BackTraceHash OPTIONAL
 150         )
 151 {
 152         UNIMPLEMENTED;
 153         return 0;
 154 }
 155
 156 /* EOF */
 157