How to get the physical drive's volume id? - c++

Question

Problem
I'm trying to get the volume id from a physical drive.
My Code
// define disk handle
HANDLE VDHANDLE;
// set "open disk" parameters
OPEN_VIRTUAL_DISK_PARAMETERS VHD_OPEN_PARAM;
VHD_OPEN_PARAM.Version = OPEN_VIRTUAL_DISK_VERSION_1;
VHD_OPEN_PARAM.Version1.RWDepth = OPEN_VIRTUAL_DISK_RW_DEPTH_DEFAULT;
// set storage type
VIRTUAL_STORAGE_TYPE VHD_STORAGE;
VHD_STORAGE.DeviceId = VIRTUAL_STORAGE_TYPE_DEVICE_VHD;
VHD_STORAGE.VendorId = VIRTUAL_STORAGE_TYPE_VENDOR_MICROSOFT;
// set "attach disk" parameters
ATTACH_VIRTUAL_DISK_PARAMETERS VHD_ATTACH_PARAM;
VHD_ATTACH_PARAM.Version = ATTACH_VIRTUAL_DISK_VERSION_1;
// open disk
if ( OpenVirtualDisk( &VHD_STORAGE, L"F:\\MyStorageBunker.vhd",
VIRTUAL_DISK_ACCESS_ALL, OPEN_VIRTUAL_DISK_FLAG_NONE,
&VHD_OPEN_PARAM, &VDHANDLE ) != ERROR_SUCCESS )
{
return ERR_MOUNT_SCRIPTCREATE;
}
// attach drive
if ( AttachVirtualDisk( VDHANDLE, 0, ATTACH_VIRTUAL_DISK_FLAG_PERMANENT_LIFETIME,
0, &VHD_ATTACH_PARAM, 0 ) != ERROR_SUCCESS )
{
return ERR_MOUNT_SCRIPTEXECUTE;
}
// Get attached drive & info
wchar_t DriveInfo[ MAX_PATH ];
ULONG bufferSize = sizeof( DriveInfo );
GetVirtualDiskPhysicalPath( VDHANDLE, &bufferSize, DriveInfo );
// DriveInfo raw output = \PHYSICALDISKX
// X = volume id
What I tried
std::wstringstream tmp;
int value;
char c;
std::wstringstream ss( DriveInfo );
ss >> tmp >> c >> value;
Issue
no operator ">>" matches these operands
Questions
How can I extract the volume id from wchar_t DriveInfo?
Is there any way to get the volume id except GetVirtualDiskPhysicalPath?

Answer 1

I cribbed this code from somewhere I can't recall, but it seems to work for getting the serial# from the first valid drive. Sorry if it doesn't compile, I had to replace our own string class with the general one. The thing you probably want out of this is the call to GetVolumeInformation()
template <class ELT> static const ELT* NextToken(const ELT* ptr) {
// Skip this null-terminated string
while (*ptr != 0) {
ptr++;
}
ptr++;
return ptr;
}
int getDiskId() {
int bufSize = GetLogicalDriveStrings(0, 0);
WCHAR* buffer = new WCHAR[bufSize];
GetLogicalDriveStrings(bufSize, buffer);
std::vector<std::string> driveStrings;
for (const WCHAR *ptr = buffer; *ptr != 0; ptr = NextToken(ptr)) {
if (toupper(*ptr) == 'A' || toupper(*ptr) == 'B') {
continue;
}
std::string tmp;
tmp += toupper(*ptr);
driveStrings.push_back(tmp);
}
// want lowest letter first
std::sort(driveStrings.begin(), driveStrings.end());
for (int i = 0; i < driveStrings.size(); i++) {
DWORD dummy(0);
DWORD serialNumber(0);
if (
GetVolumeInformation(
driveStrings[i].c_str(), // lpRootPathName
0, // lpVolumeNameBuffer
0, // nVolumeNameSize
&serialNumber,
&dummy, // lpMaximumComponentLength
&dummy, // lpFileSystemFlags
0, // lpFileSystemNameBuffer
0 // nFileSystemNameSize
)
) {
break;
}
}
delete [] buffer;
return serialNumber;
}