135 lines
3.6 KiB
C++
135 lines
3.6 KiB
C++
// this file almost totally copied from MSDN
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#include <windows.h>
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#include <stdio.h>
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#include <winioctl.h>
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#define LOCK_TIMEOUT 3000 // 10 Seconds
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#define LOCK_RETRIES 20
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static HANDLE OpenVolume(TCHAR cDriveLetter)
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{
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HANDLE hVolume;
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UINT uDriveType;
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wchar_t szVolumeName[8] = {0};
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wchar_t szRootName[5] = {0};
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DWORD dwAccessFlags;
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wsprintf(szRootName, L"%c:\\", cDriveLetter);
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uDriveType = GetDriveType(szRootName);
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switch(uDriveType) {
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case DRIVE_REMOVABLE:
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dwAccessFlags = GENERIC_READ | GENERIC_WRITE;
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break;
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case DRIVE_CDROM:
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dwAccessFlags = GENERIC_READ;
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break;
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default:
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printf("Cannot eject. Drive type is incorrect.\n");
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return INVALID_HANDLE_VALUE;
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}
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wsprintf(szVolumeName, L"\\\\.\\%c:", cDriveLetter);
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hVolume = CreateFile( szVolumeName,
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dwAccessFlags,
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FILE_SHARE_READ | FILE_SHARE_WRITE,
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NULL,
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OPEN_EXISTING,
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0,
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NULL );
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if (hVolume == INVALID_HANDLE_VALUE)
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printf("CreateFile error %d\n", GetLastError());
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return hVolume;
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}
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static BOOL CloseVolume(HANDLE hVolume)
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{
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return CloseHandle(hVolume);
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}
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static BOOL LockVolume(HANDLE hVolume)
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{
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DWORD dwBytesReturned;
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DWORD dwSleepAmount;
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int nTryCount;
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dwSleepAmount = LOCK_TIMEOUT / LOCK_RETRIES;
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// Do this in a loop until a timeout period has expired
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for (nTryCount = 0; nTryCount < LOCK_RETRIES; nTryCount++) {
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if (DeviceIoControl(hVolume,
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FSCTL_LOCK_VOLUME,
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NULL, 0,
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NULL, 0,
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&dwBytesReturned,
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NULL))
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return TRUE;
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Sleep(dwSleepAmount);
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}
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return FALSE;
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}
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static BOOL DismountVolume(HANDLE hVolume)
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{
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DWORD dwBytesReturned;
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return DeviceIoControl( hVolume,
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FSCTL_DISMOUNT_VOLUME,
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NULL, 0,
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NULL, 0,
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&dwBytesReturned,
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NULL);
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}
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static BOOL PreventRemovalOfVolume(HANDLE hVolume, BOOL fPreventRemoval)
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{
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DWORD dwBytesReturned;
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PREVENT_MEDIA_REMOVAL PMRBuffer;
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PMRBuffer.PreventMediaRemoval = fPreventRemoval;
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return DeviceIoControl( hVolume,
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IOCTL_STORAGE_MEDIA_REMOVAL,
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&PMRBuffer, sizeof(PREVENT_MEDIA_REMOVAL),
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NULL, 0,
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&dwBytesReturned,
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NULL);
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}
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static int AutoEjectVolume(HANDLE hVolume)
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{
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DWORD dwBytesReturned;
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return DeviceIoControl( hVolume,
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IOCTL_STORAGE_EJECT_MEDIA,
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NULL, 0,
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NULL, 0,
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&dwBytesReturned,
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NULL);
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}
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BOOL EjectVolume(TCHAR cDriveLetter)
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{
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BOOL fAutoEject = FALSE;
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HANDLE hVolume = OpenVolume(cDriveLetter);
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if (hVolume == INVALID_HANDLE_VALUE)
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return FALSE;
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// Lock and dismount the volume.
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if (LockVolume(hVolume) && DismountVolume(hVolume)) {
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// Set prevent removal to false and eject the volume.
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if (PreventRemovalOfVolume(hVolume, FALSE) && AutoEjectVolume(hVolume))
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fAutoEject = TRUE;
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}
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// Close the volume so other processes can use the drive.
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if (!CloseVolume(hVolume))
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return FALSE;
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if (fAutoEject) return TRUE;
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else return FALSE;
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} |