dll/win32/fltlib/fltlib.c

   1 /*
   2 * PROJECT:         Filesystem Filter Manager library
   3 * LICENSE:         GPL - See COPYING in the top level directory
   4 * FILE:            dll/win32/fltlib/fltlib.c
   5 * PURPOSE:
   6 * PROGRAMMERS:     Ged Murphy (ged.murphy@reactos.org)
   7 */
   8
   9 #include <stdarg.h>
  10
  11 #define WIN32_NO_STATUS
  12
  13 #include <windef.h>
  14 #include <winbase.h>
  15
  16 #define NTOS_MODE_USER
  17 #include <ndk/iofuncs.h>
  18 #include <ndk/obfuncs.h>
  19 #include <ndk/rtlfuncs.h>
  20 #include <fltmgr_shared.h>
  21
  22 /* DATA ****************************************************************************/
  23
  24 static
  25 HRESULT
  26 FilterLoadUnload(_In_z_ LPCWSTR lpFilterName,
  27                  _In_ BOOL Load);
  28
  29 static
  30 DWORD
  31 SendIoctl(_In_ HANDLE Handle,
  32           _In_ ULONG IoControlCode,
  33           _In_reads_bytes_opt_(BufferSize) LPVOID lpInBuffer,
  34           _In_ DWORD BufferSize);
  35
  36
  37 /* PUBLIC FUNCTIONS ****************************************************************/
  38
  39 _Must_inspect_result_
  40 HRESULT
  41 WINAPI
  42 FilterLoad(_In_ LPCWSTR lpFilterName)
  43 {
  44     return FilterLoadUnload(lpFilterName, TRUE);
  45 }
  46
  47 _Must_inspect_result_
  48 HRESULT
  49 WINAPI
  50 FilterUnload(_In_ LPCWSTR lpFilterName)
  51 {
  52     return FilterLoadUnload(lpFilterName, FALSE);
  53 }
  54
  55
  56 /* PRIVATE FUNCTIONS ****************************************************************/
  57
  58 HRESULT
  59 NtStatusToHResult(_In_ NTSTATUS Status)
  60 {
  61     HRESULT hr;
  62     hr = RtlNtStatusToDosError(Status);
  63     if (hr != ERROR_SUCCESS)
  64     {
  65         hr = (ULONG)hr | 0x80070000;
  66     }
  67     return hr;
  68 }
  69
  70 static
  71 HRESULT
  72 FilterLoadUnload(_In_z_ LPCWSTR lpFilterName,
  73                  _In_ BOOL Load)
  74 {
  75     PFILTER_NAME FilterName;
  76     HANDLE hFltMgr;
  77     SIZE_T StringLength;
  78     SIZE_T BufferLength;
  79     DWORD dwError;
  80
  81     /* Get a handle to the filter manager */
  82     hFltMgr = CreateFileW(L"\\\\.\\fltmgr",
  83                           GENERIC_WRITE,
  84                           FILE_SHARE_WRITE,
  85                           NULL,
  86                           OPEN_EXISTING,
  87                           FILE_ATTRIBUTE_NORMAL,
  88                           &hFltMgr);
  89     if (hFltMgr == INVALID_HANDLE_VALUE)
  90     {
  91         dwError = GetLastError();
  92         return HRESULT_FROM_WIN32(dwError);
  93     }
  94
  95     /* Calc and allocate a buffer to hold our filter name */
  96     StringLength = wcslen(lpFilterName) * sizeof(WCHAR);
  97     BufferLength = StringLength + sizeof(FILTER_NAME);
  98     FilterName = RtlAllocateHeap(GetProcessHeap(),
  99                                  0,
 100                                  BufferLength);
 101     if (FilterName == NULL)
 102     {
 103         CloseHandle(hFltMgr);
 104         return HRESULT_FROM_WIN32(ERROR_OUTOFMEMORY);
 105     }
 106
 107     /* Build up the filter name */
 108     FilterName->Length = StringLength;
 109     CopyMemory(FilterName->FilterName, lpFilterName, StringLength);
 110
 111     /* Tell the filter manager to load the filter for us */
 112     dwError = SendIoctl(hFltMgr,
 113                         Load ? IOCTL_FILTER_LOAD : IOCTL_FILTER_UNLOAD,
 114                         FilterName,
 115                         BufferLength);
 116
 117     /* Cleanup and bail*/
 118     RtlFreeHeap(GetProcessHeap(), 0, FilterName);
 119     CloseHandle(hFltMgr);
 120
 121     return HRESULT_FROM_WIN32(dwError);
 122 }
 123
 124 static
 125 DWORD
 126 SendIoctl(_In_ HANDLE Handle,
 127           _In_ ULONG IoControlCode,
 128           _In_reads_bytes_opt_(BufferSize) LPVOID lpInBuffer,
 129           _In_ DWORD BufferSize)
 130 {
 131     IO_STATUS_BLOCK IoStatusBlock;
 132     NTSTATUS Status;
 133
 134     Status = NtDeviceIoControlFile(Handle,
 135                                    NULL,
 136                                    NULL,
 137                                    NULL,
 138                                    &IoStatusBlock,
 139                                    IoControlCode,
 140                                    lpInBuffer,
 141                                    BufferSize,
 142                                    NULL,
 143                                    0);
 144     if (Status == STATUS_PENDING)
 145     {
 146         Status = NtWaitForSingleObject(Handle, FALSE, NULL);
 147         if (NT_SUCCESS(Status))
 148         {
 149             Status = IoStatusBlock.Status;
 150         }
 151     }
 152
 153     return RtlNtStatusToDosError(Status);
 154 }
 155
 156 BOOL
 157 WINAPI
 158 DllMain(_In_ HINSTANCE hinstDLL,
 159         _In_ DWORD dwReason,
 160         _In_ LPVOID lpvReserved)
 161 {
 162     switch (dwReason)
 163     {
 164     case DLL_PROCESS_ATTACH:
 165         DisableThreadLibraryCalls(hinstDLL);
 166         break;
 167     }
 168
 169     return TRUE;
 170 }