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Windows: fix high CPU usage when a favorite is configured to mount using VolumeID when its host device is connected to the machine.

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This commit is contained in:
Mounir IDRASSI
2017-06-01 01:53:03 +02:00
parent 029341a747
commit 55aa098295
6 changed files with 687 additions and 234 deletions
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53
src/Driver/Ntdriver.c
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@@ -203,6 +203,16 @@ void DumpMemory (void *mem, int size)
}
}
BOOL IsAllZeroes (unsigned char* pbData, DWORD dwDataLen)
{
while (dwDataLen--)
{
if (*pbData)
return FALSE;
pbData++;
}
return TRUE;
}
BOOL ValidateIOBufferSize (PIRP irp, size_t requiredBufferSize, ValidateIOBufferSizeType type)
{
@@ -1293,7 +1303,7 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
InitializeObjectAttributes (&ObjectAttributes, &FullFileName, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL);
if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bMatchVolumeID)
if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bComputeVolumeIDs)
access |= FILE_READ_DATA;
ntStatus = ZwCreateFile (&NtFileHandle,
@@ -1304,9 +1314,10 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
{
opentest->TCBootLoaderDetected = FALSE;
opentest->FilesystemDetected = FALSE;
opentest->VolumeIDMatched = FALSE;
memset (opentest->VolumeIDComputed, 0, sizeof (opentest->VolumeIDComputed));
memset (opentest->volumeIDs, 0, sizeof (opentest->volumeIDs));
if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bMatchVolumeID)
if (opentest->bDetectTCBootLoader || opentest->DetectFilesystem || opentest->bComputeVolumeIDs)
{
byte *readBuffer = TCalloc (TC_MAX_VOLUME_SECTOR_SIZE);
if (!readBuffer)
@@ -1352,27 +1363,30 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
{
switch (BE64 (*(uint64 *) readBuffer))
{
case 0xEB52904E54465320: // NTFS
case 0xEB3C904D53444F53: // FAT16/FAT32
case 0xEB58904D53444F53: // FAT32
case 0xEB76904558464154: // exFAT
case 0x0000005265465300: // ReFS
case 0xEB58906D6B66732E: // FAT32 mkfs.fat
case 0xEB58906D6B646F73: // FAT32 mkfs.vfat/mkdosfs
case 0xEB3C906D6B66732E: // FAT16/FAT12 mkfs.fat
case 0xEB3C906D6B646F73: // FAT16/FAT12 mkfs.vfat/mkdosfs
case 0xEB52904E54465320ULL: // NTFS
case 0xEB3C904D53444F53ULL: // FAT16/FAT32
case 0xEB58904D53444F53ULL: // FAT32
case 0xEB76904558464154ULL: // exFAT
case 0x0000005265465300ULL: // ReFS
case 0xEB58906D6B66732EULL: // FAT32 mkfs.fat
case 0xEB58906D6B646F73ULL: // FAT32 mkfs.vfat/mkdosfs
case 0xEB3C906D6B66732EULL: // FAT16/FAT12 mkfs.fat
case 0xEB3C906D6B646F73ULL: // FAT16/FAT12 mkfs.vfat/mkdosfs
opentest->FilesystemDetected = TRUE;
break;
case 0x0000000000000000ULL:
// all 512 bytes are zeroes => unencrypted filesystem like Microsoft reserved partition
if (IsAllZeroes (readBuffer + 8, TC_VOLUME_HEADER_EFFECTIVE_SIZE - 8))
opentest->FilesystemDetected = TRUE;
break;
}
}
}
}
if (opentest->bMatchVolumeID)
if (opentest->bComputeVolumeIDs && (!opentest->DetectFilesystem || !opentest->FilesystemDetected))
{
int volumeType;
BYTE volumeID[VOLUME_ID_SIZE];
// Go through all volume types (e.g., normal, hidden)
for (volumeType = TC_VOLUME_TYPE_NORMAL;
volumeType < TC_VOLUME_TYPE_COUNT;
@@ -1404,13 +1418,8 @@ NTSTATUS ProcessMainDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION Ex
if (NT_SUCCESS (ntStatus))
{
/* compute the ID of this volume: SHA-256 of the effective header */
sha256 (volumeID, readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
if (0 == memcmp (volumeID, opentest->volumeID, VOLUME_ID_SIZE))
{
opentest->VolumeIDMatched = TRUE;
break;
}
sha256 (opentest->volumeIDs[volumeType], readBuffer, TC_VOLUME_HEADER_EFFECTIVE_SIZE);
opentest->VolumeIDComputed[volumeType] = TRUE;
}
}
}