I want to use Windows' change journal to track some file changes. I managed using an exemple code to access the said journal and read records from it. The issue I face now is that the record only holds the related file name, but not the absolute path to it. I tried using FSCTL_GET_NTFS_FILE_RECORD with DeviceIoControl to check if I could get the absolute path this way, but call to DeviceIoControl always returns me the same file record, with "FILE0" in the buffer and the reference number I gave it without the HighPart of it (eg. I give a reference number of 0x001400000015adec, and when function returns the output has a reference number of 0x000000000015adec).
Here is my code (I'm running on Windows 10)
#include <Windows.h>
#include <WinIoCtl.h>
#include <stdio.h>
#define BUF_LEN (1024 * 1024)
void main()
{
HANDLE hVol;
CHAR * pBuffer;
pBuffer = new CHAR[BUF_LEN];
USN_JOURNAL_DATA JournalData;
READ_USN_JOURNAL_DATA_V0 ReadData = {0, 0xFFFFFFFF, FALSE, 0, 0};
PUSN_RECORD UsnRecord;
DWORD dwBytes;
DWORD dwRetBytes;
DWORD dwFileRecordSize;
BYTE * pFileRecord;
hVol = CreateFile( TEXT("\\\\.\\D:"),
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL);
if( hVol == INVALID_HANDLE_VALUE )
{
printf("CreateFile failed (%d)\n", GetLastError());
return;
}
if( !DeviceIoControl( hVol,
FSCTL_QUERY_USN_JOURNAL,
NULL,
0,
&JournalData,
sizeof(JournalData),
&dwBytes,
NULL) )
{
printf( "Query journal failed (%d)\n", GetLastError());
return;
}
ReadData.UsnJournalID = JournalData.UsnJournalID;
printf( "Journal ID: %I64x\n", JournalData.UsnJournalID );
printf( "FirstUsn: %I64x\n\n", JournalData.FirstUsn );
// get single file record size
NTFS_VOLUME_DATA_BUFFER volBuffer;
if( !DeviceIoControl( hVol,
FSCTL_GET_NTFS_VOLUME_DATA,
NULL,
0,
&volBuffer,
sizeof(volBuffer),
&dwBytes,
NULL))
{
printf( "Get volume data size failed (%d)\n", GetLastError());
return;
}
dwFileRecordSize = volBuffer.BytesPerFileRecordSegment + sizeof(NTFS_FILE_RECORD_OUTPUT_BUFFER) - 1;
pFileRecord = new BYTE[dwFileRecordSize];
bool bEnd = FALSE;
WORD lastDay = 0;
WORD lastMonth = 0;
WORD lastYear = 0;
DWORD nbEntries = 0;
while (!bEnd)
{
memset( pBuffer, 0, BUF_LEN );
if( !DeviceIoControl( hVol,
FSCTL_READ_USN_JOURNAL,
&ReadData,
sizeof(ReadData),
pBuffer,
BUF_LEN,
&dwBytes,
NULL) )
{
printf( "Read journal failed (%d)\n", GetLastError());
return;
}
dwRetBytes = dwBytes - sizeof(USN);
bEnd = (dwRetBytes == 0); // we finished reading the journal
// Find the first record
UsnRecord = (PUSN_RECORD)(((PUCHAR)pBuffer) + sizeof(USN));
// This loop could go on for a long time, given the current buffer size.
while( dwRetBytes > 0 )
{
SYSTEMTIME systemTime;
FILETIME fileTime;
fileTime.dwHighDateTime = UsnRecord->TimeStamp.HighPart;
fileTime.dwLowDateTime = UsnRecord->TimeStamp.LowPart;
FileTimeToSystemTime(&fileTime, &systemTime);
if (lastDay != systemTime.wDay || lastMonth != systemTime.wMonth || lastYear != systemTime.wYear)
{
if (nbEntries != 0)
{
printf("%u entries read\n", nbEntries);
}
nbEntries = 0;
lastDay = systemTime.wDay;
lastMonth = systemTime.wMonth;
lastYear = systemTime.wYear;
printf("reading entries for %u/%u/%u...\n", lastDay, lastMonth, lastYear);
}
++nbEntries;
NTFS_FILE_RECORD_INPUT_BUFFER inputBuff;
memset(pFileRecord, 0, dwFileRecordSize);
inputBuff.FileReferenceNumber.QuadPart = UsnRecord->FileReferenceNumber;
if (!DeviceIoControl( hVol,
FSCTL_GET_NTFS_FILE_RECORD,
&inputBuff,
32,
pFileRecord,
dwFileRecordSize,
&dwBytes,
NULL))
{
printf( "get file record failed (%d)\n", GetLastError());
return;
}
NTFS_FILE_RECORD_OUTPUT_BUFFER * pFileRecordBuff = (NTFS_FILE_RECORD_OUTPUT_BUFFER *)(pFileRecord);
if (pFileRecordBuff->FileReferenceNumber.QuadPart == inputBuff.FileReferenceNumber.QuadPart)
{
printf("file record found\n%.*S\n",
pFileRecordBuff->FileRecordLength / 2,
pFileRecordBuff->FileRecordBuffer);
}
dwRetBytes -= UsnRecord->RecordLength;
// Find the next record
UsnRecord = (PUSN_RECORD)(((PCHAR)UsnRecord) +
UsnRecord->RecordLength);
}
// Update starting USN for next call
ReadData.StartUsn = *(USN *)pBuffer;
}
delete[] pBuffer;
delete[] pFileRecord;
CloseHandle(hVol);
system("pause");
}
Is there something I'm doing wrong ? Or is there another way to get the full path to a file using an USN_RECORD instance ?
you need first open file handle by call OpenFileById
function with exactly FileReferenceNumber
from USN_RECORD
(you must not zero it high 16 bits !) and then you can query file path by GetFileInformationByHandleEx
with FileNameInfo
. you got FILE_NAME_INFO
on output. or by call NtQueryInformationFile
with FileNameInformation
. The caller can query this information as long as the file is open, without any particular requirements for DesiredAccess. so code can look like.
ULONG GepPathById(HANDLE hVolumeHint, ULONGLONG FileReferenceNumber, PFILE_NAME_INFO* ppfni)
{
FILE_ID_DESCRIPTOR fid = { sizeof(fid), FileIdType };
fid.FileId.QuadPart = FileReferenceNumber;
HANDLE hFile = OpenFileById(hVolumeHint, &fid, 0, FILE_SHARE_VALID_FLAGS, 0, 0);
if (hFile == INVALID_HANDLE_VALUE)
{
return GetLastError();
}
ULONG dwErrorCode = NOERROR;
ULONG cbNeed = 0x20;
do
{
if (PFILE_NAME_INFO pfni = (PFILE_NAME_INFO)LocalAlloc(0, cbNeed))
{
dwErrorCode = GetFileInformationByHandleEx(hFile, FileNameInfo,
pfni, cbNeed - sizeof(WCHAR)) ? 0 : GetLastError();
if (!dwErrorCode)
{
*(PWSTR)((PBYTE)pfni->FileName + pfni->FileNameLength) = 0;
*ppfni = pfni;
break;
}
cbNeed = FIELD_OFFSET(FILE_NAME_INFO, FileName) + pfni->FileNameLength + sizeof(WCHAR);
LocalFree(pfni);
}
else
{
dwErrorCode = GetLastError();
break;
}
} while (dwErrorCode == ERROR_MORE_DATA);
CloseHandle(hFile);
return dwErrorCode;
}
and usage
PFILE_NAME_INFO pfni;
if (!GepPathById(hVol, UsnRecord->FileReferenceNumber, &pfni))
{
DbgPrint("%S\n", pfni->FileName);
LocalFree(pfni);
}
static FILE_ID_DESCRIPTOR getFileIdDescriptor(const DWORDLONG fileId)
{
FILE_ID_DESCRIPTOR fileDescriptor;
fileDescriptor.Type = FileIdType;
fileDescriptor.FileId.QuadPart = fileId;
fileDescriptor.dwSize = sizeof(fileDescriptor);
return fileDescriptor;
}
FILE_ID_DESCRIPTOR f = getFileIdDescriptor(pRecord->FileReferenceNumber);
TCHAR wFilePath[MAX_PATH];
HANDLE handle = OpenFileById(hDevice, (LPFILE_ID_DESCRIPTOR) & (f), 0, 0, 0, 0);
GetFinalPathNameByHandle(handle, wFilePath, MAX_PATH, 0);
CloseHandle(handle);
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