reactos/drivers/filters/fltmgr/Lib.c

   1 /*
   2 * PROJECT:         Filesystem Filter Manager
   3 * LICENSE:         GPL - See COPYING in the top level directory
   4 * FILE:            drivers/fs_minifilter/fltmgr/Lib.c
   5 * PURPOSE:         Miscellaneous library functions
   6 * PROGRAMMERS:     Ged Murphy (gedmurphy@reactos.org)
   7 */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include "fltmgr.h"
  12
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16
  17 /* DATA *********************************************************************/
  18
  19
  20
  21 /* FUNCTIONS **********************************************/
  22
  23 VOID
  24 FltpFreeUnicodeString(_In_ PUNICODE_STRING String)
  25 {
  26     /* Free up any existing buffer */
  27     if (String->Buffer)
  28     {
  29         ExFreePoolWithTag(String->Buffer, FM_TAG_UNICODE_STRING);
  30     }
  31
  32     /* Empty the string */
  33     String->Buffer = NULL;
  34     String->Length = 0;
  35     String->MaximumLength = 0;
  36 }
  37
  38 NTSTATUS
  39 FltpReallocateUnicodeString(_In_ PUNICODE_STRING String,
  40                             _In_ SIZE_T NewLength,
  41                             _In_ BOOLEAN CopyExisting)
  42 {
  43     PWCH NewBuffer;
  44
  45     /* Don't bother reallocating if the buffer is smaller */
  46     if (NewLength <= String->MaximumLength)
  47     {
  48         String->Length = 0;
  49         return STATUS_SUCCESS;
  50     }
  51
  52     /* Allocate a new buffer at the size requested */
  53     NewBuffer = ExAllocatePoolWithTag(PagedPool, NewLength, FM_TAG_UNICODE_STRING);
  54     if (NewBuffer == NULL) return STATUS_INSUFFICIENT_RESOURCES;
  55
  56     if (CopyExisting)
  57     {
  58         /* Copy the old data across */
  59         RtlCopyMemory(NewBuffer, String->Buffer, String->Length);
  60     }
  61     else
  62     {
  63         /* Reset the length */
  64         String->Length = 0;
  65     }
  66
  67     /* Free any old buffer */
  68     if (String->Buffer)
  69         ExFreePoolWithTag(String->Buffer, FM_TAG_UNICODE_STRING);
  70
  71     /* Update the lengths */
  72     String->Buffer = NewBuffer;
  73     String->MaximumLength = NewLength;
  74
  75     return STATUS_SUCCESS;
  76 }
  77
  78 NTSTATUS
  79 FltpCopyUnicodeString(_In_ PUNICODE_STRING StringOne,
  80                       _In_ PUNICODE_STRING StringTwo)
  81 {
  82     return 0;
  83 }