windows-nt/Source/XPSP1/NT/base/fs/ntfs/tests/fastfind/fastfind.c
2020-09-26 16:20:57 +08:00

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// fastfind.c
#include <stdio.h>
#include <string.h>
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <windows.h>
#include <ntioapi.h>
#include <myntfs.h>
#define VOLUME_PATH L"\\\\.\\H:"
#define VOLUME_DRIVE_LETTER_INDEX 4
#define FULL_PATH L"\\??\\H:\\1234567890123456"
#define FULL_DRIVE_LETTER_INDEX 4
#define DEVICE_PREFIX_LEN 14
typedef struct _EXTENT {
LONGLONG Vcn;
LONGLONG Lcn;
LONGLONG Length;
} EXTENT, *PEXTENT;
#define MAX_EXTENTS 64
//
// Some globals.
//
LARGE_INTEGER MftStart;
ULONG ClusterSize;
ULONG FrsSize;
EXTENT Extents[MAX_EXTENTS];
ULONG DebugLevel;
UCHAR CacheBuffer[0x10000]; // max cluster size
LONGLONG CachedOffset = -1;
char mybuffer[32768];
LONGLONG
ComputeFileRecordLbo (
IN ULONG MftIndex
)
{
LONGLONG vcn;
LONGLONG lcn = 0;
ULONG extentIndex;
ULONG offsetWithinCluster;
vcn = (MftIndex * FrsSize) / ClusterSize;
for (extentIndex = 0; extentIndex < MAX_EXTENTS; extentIndex += 1) {
if ((vcn >= Extents[extentIndex].Vcn) &&
(vcn < Extents[extentIndex].Vcn + Extents[extentIndex].Length)) {
lcn = Extents[extentIndex].Lcn + (vcn - Extents[extentIndex].Vcn);
}
}
if (ClusterSize >= FrsSize ) {
offsetWithinCluster = (MftIndex % (ClusterSize / FrsSize)) * FrsSize;
return (lcn * ClusterSize + offsetWithinCluster);
} else {
//
// BUGBUG keithka 4/28/00 Handle old fashioned big frs and/or big
// clusters someday.
//
ASSERT( FALSE );
return 0;
}
}
VOID
FindAttributeInFileRecord (
IN PFILE_RECORD_SEGMENT_HEADER FileRecord,
IN ATTRIBUTE_TYPE_CODE TypeCode,
IN PATTRIBUTE_RECORD_HEADER PreviousAttribute OPTIONAL,
OUT PATTRIBUTE_RECORD_HEADER *Attribute
)
// Attribute set to NULL if not found.
{
PATTRIBUTE_RECORD_HEADER attr;
*Attribute = NULL;
if (FileRecord->Pad0[0] != 'F' ||
FileRecord->Pad0[1] != 'I' ||
FileRecord->Pad0[2] != 'L' ||
FileRecord->Pad0[3] != 'E') {
if (DebugLevel >= 1) {
printf( "\nBad MFT record %c%c%c%c",
FileRecord->Pad0[0],
FileRecord->Pad0[1],
FileRecord->Pad0[2],
FileRecord->Pad0[3] );
}
//
// This isn't a good file record, but that doesn't make this a corrupt volume.
// It's possible that this file record has never been used. Since we don't look
// at the MFT bitmap, we don't know if this was expected to be a valid filerecord.
// The output Attribute is set to NULL already, so we can exit now.
//
return;
}
if (0 == (FileRecord->Flags & FILE_RECORD_SEGMENT_IN_USE)) {
//
// File record not in use, skip it.
//
return;
}
if (NULL == PreviousAttribute) {
attr = (PATTRIBUTE_RECORD_HEADER) ((PUCHAR)FileRecord + FileRecord->FirstAttributeOffset);
} else {
attr = (PATTRIBUTE_RECORD_HEADER) ((PUCHAR) PreviousAttribute + PreviousAttribute->RecordLength);
if (((PUCHAR)attr - (PUCHAR)FileRecord) > (LONG) FrsSize) {
ASSERT (FALSE);
return;
}
}
while (attr->TypeCode < TypeCode &&
attr->TypeCode != $END) {
ASSERT( attr->RecordLength < FrsSize );
attr = (PATTRIBUTE_RECORD_HEADER) ((PUCHAR) attr + attr->RecordLength);
//
// BUGBUG keitha 4/20/00 need to handle attribute list case someday...
// It's relativley rare that an MFT gets so fragmented it needs an
// attribute list. Certainly rare enough to skip it for now in a
// piece of test code.
//
}
if (attr->TypeCode == TypeCode) {
*Attribute = attr;
}
return;
}
BOOLEAN
FindNameInFileRecord (
IN PFILE_RECORD_SEGMENT_HEADER FileRecord,
IN PWCHAR FileName,
IN ULONG FileNameLength
)
{
PATTRIBUTE_RECORD_HEADER attr;
PFILE_NAME fileNameAttr;
ULONG cmpResult;
FindAttributeInFileRecord( FileRecord,
$FILE_NAME,
NULL,
&attr );
while (NULL != attr) {
if (((PUCHAR)attr - (PUCHAR)FileRecord) > (LONG) FrsSize) {
ASSERT( FALSE );
return FALSE;
}
//
// Names shouldn't go nonresident.
//
if (attr->FormCode != RESIDENT_FORM) {
ASSERT( FALSE );
return FALSE;
}
fileNameAttr = (PFILE_NAME) ((PUCHAR)attr + attr->Form.Resident.ValueOffset);
if (fileNameAttr->FileNameLength == FileNameLength) {
cmpResult = wcsncmp( FileName,
(PWCHAR) fileNameAttr->FileName,
fileNameAttr->FileNameLength );
if (0 == cmpResult) {
return TRUE;
}
} else if (DebugLevel >= 3) {
printf( "\nNot a match %S,%S", FileName, fileNameAttr->FileName );
}
//
// Find the next filename, if any.
//
FindAttributeInFileRecord( FileRecord,
$FILE_NAME,
attr,
&attr );
}
return FALSE;
}
int
FsTestOpenById (
IN UCHAR *ObjectId,
IN HANDLE VolumeHandle
)
{
HANDLE File;
IO_STATUS_BLOCK IoStatusBlock;
NTSTATUS Status;
NTSTATUS GetNameStatus;
NTSTATUS CloseStatus;
OBJECT_ATTRIBUTES ObjectAttributes;
UNICODE_STRING str;
WCHAR nameBuffer[MAX_PATH];
PFILE_NAME_INFORMATION FileName;
WCHAR Full[] = FULL_PATH; // Arrays of WCHAR's aren't constants
RtlInitUnicodeString( &str, Full );
str.Length = 8;
RtlCopyMemory( &str.Buffer[0], // no device prefix for relative open.
ObjectId,
8 );
InitializeObjectAttributes( &ObjectAttributes,
&str,
OBJ_CASE_INSENSITIVE,
VolumeHandle,
NULL );
Status = NtCreateFile( &File,
GENERIC_READ,
&ObjectAttributes,
&IoStatusBlock,
NULL,
FILE_ATTRIBUTE_NORMAL,
FILE_SHARE_READ | FILE_SHARE_WRITE,
FILE_OPEN,
FILE_OPEN_BY_FILE_ID,
NULL,
0 );
if (NT_SUCCESS( Status )) {
RtlZeroMemory( nameBuffer, sizeof(nameBuffer) );
FileName = (PFILE_NAME_INFORMATION) &nameBuffer[0];
FileName->FileNameLength = sizeof(nameBuffer) - sizeof(ULONG);
GetNameStatus = NtQueryInformationFile( File,
&IoStatusBlock,
FileName,
sizeof(nameBuffer),
FileNameInformation );
printf( "%S\n", FileName->FileName );
CloseStatus = NtClose( File );
if (!NT_SUCCESS( CloseStatus )) {
printf( "\nCloseStatus %x", CloseStatus );
}
}
return Status;
}
NTSTATUS
ReadFileRecord (
IN HANDLE VolumeHandle,
IN ULONG RecordIndex,
IN OUT PVOID Buffer
)
{
NTSTATUS status;
LARGE_INTEGER byteOffset;
IO_STATUS_BLOCK ioStatusBlock;
ULONG offsetWithinBuffer;
byteOffset.QuadPart = ComputeFileRecordLbo( RecordIndex );
if (FrsSize >= ClusterSize) {
status = NtReadFile( VolumeHandle,
NULL, // Event
NULL, // ApcRoutine
NULL, // ApcContext
&ioStatusBlock,
Buffer,
FrsSize,
&byteOffset, // ByteOffset
NULL ); // Key
} else {
//
// Clusters bigger than filerecords, do cluster
// size reads and dice up the returns.
//
if ((-1 == CachedOffset) ||
(byteOffset.QuadPart < CachedOffset) ||
((byteOffset.QuadPart + FrsSize) > (CachedOffset + ClusterSize))) {
if (DebugLevel >= 1) {
printf( "\nCache miss at %I64x", byteOffset.QuadPart );
}
status = NtReadFile( VolumeHandle,
NULL, // Event
NULL, // ApcRoutine
NULL, // ApcContext
&ioStatusBlock,
CacheBuffer,
ClusterSize,
&byteOffset, // ByteOffset
NULL ); // Key
if (STATUS_SUCCESS != status) {
//
// The cache buffer may be junk now, reread it next time.
//
CachedOffset = -1;
return status;
}
CachedOffset = byteOffset.QuadPart;
offsetWithinBuffer = 0;
} else {
if (DebugLevel >= 1) {
printf( "\nCache hit at %I64x", byteOffset.QuadPart );
}
offsetWithinBuffer = (ULONG) (byteOffset.QuadPart % CachedOffset);
status = STATUS_SUCCESS;
}
RtlCopyMemory( Buffer, CacheBuffer + offsetWithinBuffer, FrsSize );
}
return status;
}
int
FastFind (
IN PWCHAR FileName,
IN PWCHAR DriveLetter
)
{
IO_STATUS_BLOCK IoStatusBlock;
UNICODE_STRING str;
NTSTATUS Status;
NTSTATUS ReadStatus;
NTSTATUS CloseStatus;
LARGE_INTEGER byteOffset;
LONGLONG mftBytesRead;
HANDLE volumeHandle;
DWORD WStatus;
WCHAR Full[] = FULL_PATH; // Arrays of WCHAR's aren't constants
WCHAR Volume[] = VOLUME_PATH;
BIOS_PARAMETER_BLOCK bpb;
PPACKED_BOOT_SECTOR bootSector;
PFILE_RECORD_SEGMENT_HEADER fileRecord;
PATTRIBUTE_RECORD_HEADER attr;
VCN nextVcn;
VCN currentVcn;
VCN vcnDelta;
LCN currentLcn;
LCN lcnDelta;
PUCHAR bsPtr;
UCHAR v;
UCHAR l;
UCHAR i;
ULONG extentCount;
ULONG recordIndex;
ULONG mftRecords;
ULONG fileNameLength;
MFT_SEGMENT_REFERENCE segRef;
RtlInitUnicodeString( &str, Full );
RtlCopyMemory( &str.Buffer[FULL_DRIVE_LETTER_INDEX], DriveLetter, sizeof(WCHAR) );
str.Length = 0x1E;
//
// Open the volume for relative opens.
//
RtlCopyMemory( &Volume[VOLUME_DRIVE_LETTER_INDEX], DriveLetter, sizeof(WCHAR) );
printf( "\nOpening volume handle, this may take a while..." );
volumeHandle = CreateFileW( (PUSHORT) &Volume,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL );
if (volumeHandle == INVALID_HANDLE_VALUE) {
WStatus = GetLastError();
printf( "Unable to open %ws volume\n", &Volume );
printf( "Error from CreateFile", WStatus );
return WStatus;
}
printf( "\nVolume handle opened, starting MFT scan" );
byteOffset.QuadPart = 0;
ReadStatus = NtReadFile( volumeHandle,
NULL, // Event
NULL, // ApcRoutine
NULL, // ApcContext
&IoStatusBlock,
mybuffer,
0x200,
&byteOffset, // ByteOffset
NULL ); // Key
if (STATUS_SUCCESS != ReadStatus) {
printf( "\nBoot sector read failed with status %x", ReadStatus );
goto exit;
}
bootSector = (PPACKED_BOOT_SECTOR) mybuffer;
if (bootSector->Oem[0] != 'N' ||
bootSector->Oem[1] != 'T' ||
bootSector->Oem[2] != 'F' ||
bootSector->Oem[3] != 'S') {
printf( "\nNot an NTFS volume" );
goto exit;
}
NtfsUnpackBios( &bpb, &bootSector->PackedBpb );
ClusterSize = bpb.BytesPerSector * bpb.SectorsPerCluster;
if (bootSector->ClustersPerFileRecordSegment < 0) {
FrsSize = 1 << (-1 * bootSector->ClustersPerFileRecordSegment);
} else {
FrsSize = bootSector->ClustersPerFileRecordSegment * ClusterSize;
}
MftStart.QuadPart = ClusterSize * bootSector->MftStartLcn;
mftBytesRead = 0;
ReadStatus = NtReadFile( volumeHandle,
NULL, // Event
NULL, // ApcRoutine
NULL, // ApcContext
&IoStatusBlock,
mybuffer,
FrsSize,
&MftStart, // ByteOffset
NULL ); // Key
if (STATUS_SUCCESS != ReadStatus) {
printf( "\nMFT record 0 read failed with status %x", ReadStatus );
goto exit;
}
mftBytesRead += IoStatusBlock.Information;
FindAttributeInFileRecord( (PFILE_RECORD_SEGMENT_HEADER) mybuffer,
$DATA,
NULL,
&attr );
if (NULL == attr) {
printf( "\nMFT record 0 has no $DATA attribute" );
goto exit;
}
if (attr->FormCode == RESIDENT_FORM) {
printf( "\nVolume has very few files, use dir /s" );
goto exit;
}
//
// BUGBUG keithka 4/28/00 Handle MFT with more than 4billion entries.
//
ASSERT (attr->Form.Nonresident.FileSize <= MAXULONG);
mftRecords = (ULONG) (attr->Form.Nonresident.FileSize / FrsSize);
//
// Crack mapping pairs, read those clusters in a few big trnasfers,
// seek out given filename in those buffers.
//
nextVcn = attr->Form.Nonresident.LowestVcn;
currentLcn = 0;
extentCount = 0;
RtlZeroMemory( Extents, sizeof(Extents) );
bsPtr = ((PUCHAR) attr) + attr->Form.Nonresident.MappingPairsOffset;
while (*bsPtr != 0) {
currentVcn = nextVcn;
//
// Variable names v and l used for consistency with comments in
// ATTRIBUTE_RECORD_HEADER struct explaining how to decompress
// mapping pair information.
//
v = (*bsPtr) & 0xf;
l = ((*bsPtr) & 0xf0) >> 4;
bsPtr += 1;
for (vcnDelta = 0, i = 0; i < v; i++) {
vcnDelta += *(bsPtr++) << (8 * i);
}
for (lcnDelta = 0, i = 0; i < l; i++) {
lcnDelta += *(bsPtr++) << (8 * i);
}
//
// Sign extend.
//
if (0x80 & (*(bsPtr - 1))) {
for(; i < sizeof(lcnDelta); i++) {
lcnDelta += 0xff << (8 * i);
}
}
currentLcn += lcnDelta;
// printf( "\nVcn %I64x, Lcn %I64x, Length %I64x", currentVcn, currentLcn, vcnDelta );
if (extentCount < MAX_EXTENTS) {
Extents[extentCount].Vcn = currentVcn;
Extents[extentCount].Lcn = currentLcn;
Extents[extentCount].Length = vcnDelta;
extentCount += 1;
} else {
printf( "\nExcessive MFT fragmentation, redefine MAX_EXTENTS and recompile" );
}
currentVcn += vcnDelta;
}
//
// Now we know where the MFT is, let's go read it.
//
fileNameLength = wcslen( FileName );
for (recordIndex = 0; recordIndex <= mftRecords; recordIndex++) {
ReadStatus = ReadFileRecord( volumeHandle,
recordIndex,
mybuffer );
if (STATUS_SUCCESS != ReadStatus) {
printf( "\nMFT record read failed with status %x", ReadStatus );
goto exit;
}
if (FindNameInFileRecord( (PFILE_RECORD_SEGMENT_HEADER) mybuffer,
FileName,
fileNameLength )) {
//
// Found a match, open by id and retrieve name.
//
if (DebugLevel >= 1) {
printf( "\nFound match in file %08x %08x\n",
((PFILE_RECORD_SEGMENT_HEADER) mybuffer)->SequenceNumber,
recordIndex );
} else {
printf( "\n" );
}
segRef.SegmentNumberLowPart = recordIndex;
segRef.SegmentNumberHighPart = 0;
segRef.SequenceNumber = ((PFILE_RECORD_SEGMENT_HEADER) mybuffer)->SequenceNumber;
FsTestOpenById( (PUCHAR) &segRef, volumeHandle );
}
//
// The number 0x400 is completely arbitrary. It's a reasonable interval
// of work to do before printing another period to tell the user we're
// making progress still.
//
if (0 == (recordIndex % 0x400)) {
printf( "." );
}
}
exit:
if (volumeHandle != NULL) {
CloseHandle( volumeHandle );
}
return 0;
}
VOID
FastFindHelp (
char *ExeName
)
{
printf( "This program finds a file by scanning the MFT (ntfs only).\n\n" );
printf( "usage: %s x: filename\n", ExeName );
printf( "Where x: is the drive letter\n" );
printf( "example:\n" );
printf( "%s d: windows.h", ExeName );
}
VOID
_cdecl
main (
int argc,
char *argv[]
)
{
WCHAR drive;
ANSI_STRING fileName;
WCHAR uniBuff[MAX_PATH];
UNICODE_STRING uniFileName;
//
// Get parameters.
//
if (argc < 3) {
FastFindHelp( argv[0] );
return;
}
if (argc >= 4) {
sscanf( argv[3], "%x", &DebugLevel );
} else {
DebugLevel = 0;
}
drive = *argv[1];
RtlInitAnsiString( &fileName, argv[2] );
uniFileName.Buffer = uniBuff;
RtlAnsiStringToUnicodeString( &uniFileName, &fileName, FALSE );
FastFind( uniFileName.Buffer, &drive );
return;
}