Invalid handle when calling IOCTL_STORAGE_GET_MEDIA_SERIAL_NUMBER - c++

Question

Anyone out there have experience of c/c++ IOCTL calls?
Basically I'm trying to identify what port a USB memory stick is plugged into.
I have all the USB info and have volume info. Apparantly to link these 2 blocks of info I need either the driver-key or serial-number.
However when calling DeviceIoControl I'm getting invalid handle as the "last error code"
My drive USB drive mounted to a directory in c:\ (not a drive letter) See below
//get a handle on the volume
HANDLE hVolume;
DWORD dwAccessFlags;
dwAccessFlags = GENERIC_READ | GENERIC_WRITE;
hVolume = CreateFile(L"C:\_USB\MP1",
dwAccessFlags,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL );
if (hVolume == INVALID_HANDLE_VALUE) {
printf("Invalid Handle");
}
//use the handle
MEDIA_SERIAL_NUMBER_DATA* pserialNumberData = new MEDIA_SERIAL_NUMBER_DATA;
wstring result;
//HANDLE hVolume = OpenVolume(vname.substr(0, vname.length() - 1).c_str());
DWORD bytesReturned = 0;
LPDWORD lpBytesReturned = &bytesReturned;
OVERLAPPED over;
LPOVERLAPPED lpOver = &over;
BOOL success = 1;
success = DeviceIoControl(
(HANDLE) hVolume, // handle to device
IOCTL_STORAGE_GET_MEDIA_SERIAL_NUMBER, // dwIoControlCode
NULL, // lpInBuffer
0, // nInBufferSize
(LPVOID) pserialNumberData, // output buffer
(DWORD) sizeof(MEDIA_SERIAL_NUMBER_DATA), // size of output buffer
(LPDWORD) lpBytesReturned, // number of bytes returned
(LPOVERLAPPED) lpOver // OVERLAPPED structure
);
wcout << L"--> GetSn() DeviceIoControl success " << success << endl;
wcout << L"--> GetSn() DeviceIoControl Last error number " << GetLastError() << endl;
wcout << L"--> GetSn() DeviceIoControl Bytes Returned " << bytesReturned << endl;
wcout << L"--> GetSn() DeviceIoControl struct size " << sizeof(MEDIA_SERIAL_NUMBER_DATA) << endl;

Answer 1

If you look at the Remarks section for the DeviceIoControl function, it says:
To retrieve a handle to the device, you must call the CreateFile function with either the name of a device or the name of the driver associated with a device. To specify a device name, use the following format:
\\.\DeviceName
DeviceIoControl can accept a handle to a specific device. For example, to open a handle to the logical drive A: with CreateFile, specify \\.\a:. Alternatively, you can use the names \\.\PhysicalDrive0, \\.\PhysicalDrive1, and so on, to open handles to the physical drives on a system.
You are not opening a device handle, and thus DeviceIoControl is not going to work for that case.

Answer 2

The first big problem I see is that the CreateFile function must be called with the FILE_FLAG_BACKUP_SEMANTICS flag in order to get a valid handle to a directory. So, for starters, try:
hVolume = CreateFile( L"C:\_USB\MP1",
dwAccessFlags,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS,
NULL );

Answer 3

Hmmm... I think the handle you get from CreateFile is the handle to the directory you mounted your drive to, rather than the drive itself. To be sure you get the handle to device you want, you should use a device path, e.g. \\.\Device\HarddiskVolume1. WinObj or DeviceTree can probably help you find the path to your usb drive.