/**************************************************************/
/* SCSI Start Stop Unit C++ Code Snippet by KnowledgeIT 2007  */
/**************************************************************/
#include <windows.h>

#ifndef IOCTL_SCSI_PASS_THROUGH_DIRECT

#define IOCTL_SCSI_PASS_THROUGH_DIRECT 0x4D014
#define SCSI_IOCTL_DATA_OUT 0
#define SCSI_IOCTL_DATA_IN 1
#define SCSI_IOCTL_DATA_UNSPECIFIED 2

typedef struct _SCSI_PASS_THROUGH_DIRECT 
{
	USHORT Length;
	UCHAR ScsiStatus;
	UCHAR PathId;
	UCHAR TargetId;
	UCHAR Lun;
	UCHAR CdbLength;
	UCHAR SenseInfoLength;
	UCHAR DataIn;
	ULONG DataTransferLength;
	ULONG TimeOutValue;
	PVOID DataBuffer;
	ULONG SenseInfoOffset;
	UCHAR Cdb[16];
} SCSI_PASS_THROUGH_DIRECT, *PSCSI_PASS_THROUGH_DIRECT;

#endif 



#pragma pack(1)

#define SCSIOP_START_STOP_UNIT 0x1B

typedef struct _CDB_START_STOP_UNIT 
{
	UCHAR OperationCode; // 0x1B - SCSIOP_START_STOP_UNIT
	UCHAR Immediate : 1;
	UCHAR Reserved1 : 4;
	UCHAR Lun : 3;
	UCHAR Reserved2[2];
	UCHAR Start : 1;
	UCHAR LoadEject : 1;
	UCHAR Reserved3 : 2;
	UCHAR PowerCondition : 4;
	UCHAR Control;
} CDB_START_STOP_UNIT;

#pragma pack()

BOOL SendCBD(HANDLE device, void *cdb, UCHAR cdb_length, void *buffer, DWORD buffer_length, int data_in = SCSI_IOCTL_DATA_IN)
{
	DWORD returned;
	
	// size of SCSI_PASS_THROUGH + 96 bytes for sense data
	unsigned char cmd[sizeof(SCSI_PASS_THROUGH_DIRECT) + 96] = {0};
	
	SCSI_PASS_THROUGH_DIRECT *pcmd = (SCSI_PASS_THROUGH_DIRECT *) cmd;
	
	// Copy the CDB to the SCSI_PASS_THROUGH structure
	memcpy(pcmd->Cdb, cdb, cdb_length);
	
	pcmd->DataBuffer = buffer;
	pcmd->DataTransferLength = buffer_length;
	pcmd->DataIn = data_in;
	pcmd->CdbLength = cdb_length;
	pcmd->Length = sizeof(SCSI_PASS_THROUGH_DIRECT);
	pcmd->SenseInfoLength = sizeof(cmd) - sizeof(SCSI_PASS_THROUGH_DIRECT);
	pcmd->SenseInfoOffset = sizeof(SCSI_PASS_THROUGH_DIRECT);
	pcmd->TimeOutValue = 6000;
	
	return DeviceIoControl( 	device, 
				IOCTL_SCSI_PASS_THROUGH_DIRECT, 
				(LPVOID)&cmd, 
				sizeof(cmd), 
				(LPVOID)&cmd, 
				sizeof(cmd), 
				&returned, 
				NULL);
}


BOOL ScsiStartStopUnit(CHAR dev, BOOL start)
{
	CHAR tmp[20];
	HANDLE device;
	BOOL ret;
	
	sprintf(tmp,"\\\\.\\%c:",dev);
	device = ::CreateFile(	tmp, 
				GENERIC_READ | GENERIC_WRITE, 
				FILE_SHARE_READ | FILE_SHARE_WRITE,
				NULL,
				OPEN_EXISTING, 
				0,
				0);
	
	if (device == (HANDLE)-1)
		return FALSE;
	
	CDB_START_STOP_UNIT req = {0};
	
	req.OperationCode = SCSIOP_START_STOP_UNIT;
	req.Immediate = 1;
	req.Start = start ? 1 : 0;
	
	ret = SendCBD(device, &req, sizeof(req), NULL, 0);
	
	::CloseHandle(device);
	
	return ret;
}