ocrwblk.c

这是微软的一个USB块传输例程

			uval = 0;
			umultiplier = 1;
			// we're traversing least-to-most significant digits
			while( ( (FileName->Buffer[ ix ] >= (WCHAR) '0') &&
				(FileName->Buffer[ ix ] <= (WCHAR) '9') ) && ix ) {

				uval +=  (umultiplier *
					     (ULONG) (FileName->Buffer[ ix ] - (WCHAR) '0'));
				ix--;
				umultiplier *= 10; 
            }
		}
        pipeInfo = &deviceExtension->PipeInfo[ uval ];
    }

    BULKUSB_KdPrint ( DBGLVL_HIGH, ("Exit BulkUsb_PipeWithName() pipeInfo = 0x%x, ix = %d\n", pipeInfo, uval ));

    return pipeInfo;
}

NTSTATUS
BulkUsb_Close(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
/*++

Routine Description:

    This is the dispatch table routine for IRP_MJ_CLOSE.
    It handles user mode CloseHandle() calls for a pipe
    It closes the File Object for the pipe handle it represents.

Arguments:

    DeviceObject - pointer to our FDO (Functional Device Object )


Return Value:

    NT status code

--*/
{
    NTSTATUS ntStatus;
	NTSTATUS actStat;
    PFILE_OBJECT fileObject;
    PIO_STACK_LOCATION irpStack;
    PDEVICE_EXTENSION deviceExtension;
    PUSBD_PIPE_INFORMATION pipeHandle = NULL;
    PBULKUSB_PIPEINFO pipeInfo = NULL;

    BULKUSB_KdPrint( DBGLVL_DEFAULT,("entering BulkUsb_Close\n"));

    
    BulkUsb_IncrementIoCount(DeviceObject);

    deviceExtension = DeviceObject->DeviceExtension;
    irpStack = IoGetCurrentIrpStackLocation (Irp);
    fileObject = irpStack->FileObject;

    if (fileObject->FsContext) {
        // closing pipe handle
        pipeHandle =  fileObject->FsContext;

        pipeInfo = BulkUsb_PipeWithName( DeviceObject, &fileObject->FileName );

        if ( NULL == pipeInfo )
            goto done;

		if ( pipeInfo->fPipeOpened ) { // set if opened
			// may have been aborted
			BULKUSB_KdPrint( DBGLVL_DEFAULT,("closing pipe %x\n", pipeHandle));
			deviceExtension->OpenPipeCount--;
			pipeInfo->fPipeOpened = FALSE;
		}
		else {
			// pipe was already closed; this can only be if we got a sudden REMOVE_DEVICE
			BULKUSB_ASSERT(  deviceExtension->DeviceRemoved );
			BULKUSB_KdPrint( DBGLVL_DEFAULT,("Pipe %x was already closed \n", pipeHandle));

		}
    }

done:
	BulkUsb_DecrementIoCount(DeviceObject);
    Irp->IoStatus.Status = STATUS_SUCCESS;
    Irp->IoStatus.Information = 0;

    ntStatus = Irp->IoStatus.Status;


    IoCompleteRequest (Irp,
                       IO_NO_INCREMENT
                       );
                       
	// try to power down device if this is the last pipe
	actStat = BulkUsb_SelfSuspendOrActivate( DeviceObject, TRUE );

    BULKUSB_KdPrint( DBGLVL_DEFAULT,("exit BulkUsb_Close OpenPipeCount = decimal %d, status %x\n",deviceExtension->OpenPipeCount, ntStatus));

    return ntStatus;
}


NTSTATUS
BulkUsb_Create(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
/*++

Routine Description:

    This is the dispatch table routine for IRP_MJ_CREATE.
    It's the entry point for CreateFile() calls
    user mode apps may open "<name genned fron GUID>.\yy"
    where yy is the internal pipe id

Arguments:

    DeviceObject - pointer to our FDO ( Functional Device Object )


Return Value:

    NT status code

--*/
{
    NTSTATUS ntStatus = STATUS_SUCCESS;
    PFILE_OBJECT fileObject;
    PIO_STACK_LOCATION irpStack;
    PDEVICE_EXTENSION deviceExtension;
    ULONG i, ix;
	NTSTATUS actStat;
    PUSBD_INTERFACE_INFORMATION interface;
	PUSBD_PIPE_INFORMATION PipeInfo;
    PBULKUSB_PIPEINFO ourPipeInfo = NULL;


    deviceExtension = DeviceObject->DeviceExtension;
    interface = deviceExtension->UsbInterface;

    BULKUSB_KdPrint( DBGLVL_DEFAULT,("entering BulkUsb_Create\n"));

    BulkUsb_IncrementIoCount(DeviceObject);

    // Can't accept a new io request if:
    //  1) device is removed, 
    //  2) has never been started, 
    //  3) is stopped,
    //  4) has a remove request pending,
    //  5) has a stop device pending
    if ( !BulkUsb_CanAcceptIoRequests( DeviceObject ) ) {
        ntStatus = STATUS_DELETE_PENDING;

		BULKUSB_KdPrint( DBGLVL_DEFAULT,("ABORTING BulkUsb_Create\n"));
        goto done;
    }
    
    irpStack = IoGetCurrentIrpStackLocation (Irp);
    fileObject = irpStack->FileObject;

    // fscontext is null for device
    fileObject->FsContext = NULL;

    if ( 0 == fileObject->FileName.Length ) // this is the case if opening device as opposed to pipe
        goto done;      // nothing more to do

    ourPipeInfo = BulkUsb_PipeWithName( DeviceObject, &fileObject->FileName );

    if ( !ourPipeInfo ) {

        ntStatus = STATUS_INVALID_PARAMETER;
        goto done;

    }

	// init status to bad; will set good in below loop on success
	ntStatus = STATUS_INSUFFICIENT_RESOURCES;

	for (i=0; i<interface->NumberOfPipes; i++) {

		PipeInfo =  &interface->Pipes[i]; // PUSBD_PIPE_INFORMATION  PipeInfo;

        if ( ourPipeInfo == &deviceExtension->PipeInfo[i] ) {

    		//
			// found a match
			//
			BULKUSB_KdPrint( DBGLVL_DEFAULT,("open pipe %d\n", i));
			fileObject->FsContext = PipeInfo;
			ourPipeInfo->fPipeOpened = TRUE; // set flag for opened
			ntStatus = STATUS_SUCCESS;

			deviceExtension->OpenPipeCount++;

			// try to power up device if its not in D0
			actStat = BulkUsb_SelfSuspendOrActivate( DeviceObject, FALSE );
			break;
		}
	}

done:
    Irp->IoStatus.Status = ntStatus;
    Irp->IoStatus.Information = 0;


    IoCompleteRequest (Irp,
                       IO_NO_INCREMENT
                       );

    BulkUsb_DecrementIoCount(DeviceObject);                               

    BULKUSB_KdPrint( DBGLVL_DEFAULT,("exit BulkUsb_Create %x\n", ntStatus));


    return ntStatus;
}




BOOLEAN
BulkUsb_CancelPendingIo(
    IN PDEVICE_OBJECT DeviceObject
    )
/*++

Routine Description:
	Cancels pending IO, as on a sudden IRP_MN_REMOVE_DEVICE 
	This driver maintains and array of info structs (BULKUSB_RW_CONTEXT)
	on self-generated IRPS for staged read/writes; This routine traverses
	it and cancels all pending IO irps

Arguments:

    DeviceObject - pointer to the device object for this instance of the 82930
                    device.


Return Value:

    TRUE if cancelled any, else FALSE

--*/
{
	PDEVICE_EXTENSION deviceExtension = DeviceObject->DeviceExtension;
    PUCHAR pCon =  (PUCHAR) deviceExtension->PendingIoIrps;
	ULONG i = 0;
	PIRP Irp;
	USHORT uDriverCancel = 0;  // count cancelled via iocancelirp()
	BOOLEAN cRes; 
    NTSTATUS ntStatus, waitStatus;

	// nothing pending
	if ( !deviceExtension->PendingIoIrps )
		return FALSE;


    BULKUSB_KdPrint ( DBGLVL_MAXIMUM, ("enter BulkUsb_CancelPendingIo()\n"));


    // the BULKUSB_RW_CONTEXT array is terminated by an entry with a NULL Irp
	for ( i = 0; ((PBULKUSB_RW_CONTEXT)pCon)->Irp ;  i++ ) {

		Irp = ((PBULKUSB_RW_CONTEXT) pCon)->Irp;
		//
		// Since IoCallDriver has been called on this request, we call IoCancelIrp
		//  and let our completion routine handle it
		//
		cRes = IoCancelIrp( Irp );

		BULKUSB_KdPrint ( DBGLVL_MAXIMUM,  ("BulkUsb_CancelPendingIo() IoCancelIrp() cRes=%d, IRP 0x%x\n", cRes, Irp));

		// if cancel call failed, they all will, so dump out
		if ( !cRes )
			break;

        uDriverCancel++; // flag we tried to cancel at least one


        // point to next context struct in array
        pCon +=  sizeof( BULKUSB_RW_CONTEXT);
    } // end, for


    if ( uDriverCancel && cRes ) {

		// We only get here if we cancelled at least one and all cancellations were successfull.
        // Wait on the event set on last cancel in BulkUsb_AsyncReadWriteComplete();
	    BULKUSB_KdPrint ( DBGLVL_MAXIMUM, ("BulkUsb_CancelPendingIo() before waiting for StagingDoneEvent()\n" ));
        waitStatus = KeWaitForSingleObject(
                       &deviceExtension->StagingDoneEvent,
                       Suspended,
                       KernelMode,
                       FALSE,
                       NULL);
	    BULKUSB_KdPrint ( DBGLVL_MAXIMUM, ("BulkUsb_CancelPendingIo() finished waiting for StagingDoneEvent()\n" ));
    }

	BULKUSB_KdPrintCond ( DBGLVL_HIGH, uDriverCancel,
        ("BulkUsb_CancelPendingIo() cancelled %d via IoCancelIrp()\n",uDriverCancel));

    return (BOOLEAN) uDriverCancel;                                  

}



NTSTATUS
BulkUsb_AbortPipes(
    IN PDEVICE_OBJECT DeviceObject
    )
/*++

Routine Description:

	Called as part of sudden device removal handling.
    Cancels any pending transfers for all open pipes. 
	If any pipes are still open, call USBD with URB_FUNCTION_ABORT_PIPE
	Also marks the pipe 'closed' in our saved  configuration info.

Arguments:

    Ptrs to our FDO

Return Value:

    NT status code

--*/
{
    NTSTATUS ntStatus = STATUS_SUCCESS;
    PURB urb;
    PDEVICE_EXTENSION deviceExtension = DeviceObject->DeviceExtension;
	ULONG i;

    PUSBD_INTERFACE_INFORMATION interface;
    PBULKUSB_PIPEINFO  PipeInfo;
    PUCHAR  pInf = (PUCHAR ) deviceExtension->PipeInfo;

    interface = deviceExtension->UsbInterface;

    for (i=0; i<interface->NumberOfPipes; i++) {

        PipeInfo =  (PBULKUSB_PIPEINFO) pInf; // PBULKUSB_PIPEINFO  PipeInfo;

		if ( PipeInfo->fPipeOpened ) { // we set this if open, clear if closed

			BULKUSB_KdPrint( DBGLVL_HIGH,("BulkUsb_AbortPipes() Aborting open  Pipe %d\n", i));

			urb = BULKUSB_ExAllocatePool(NonPagedPool,
								 sizeof(struct _URB_PIPE_REQUEST));

			if (urb) {

				urb->UrbHeader.Length = (USHORT) sizeof (struct _URB_PIPE_REQUEST);
				urb->UrbHeader.Function = URB_FUNCTION_ABORT_PIPE;
				urb->UrbPipeRequest.PipeHandle =
					interface->Pipes[i].PipeHandle;

				ntStatus = BulkUsb_CallUSBD(DeviceObject, urb);

				BULKUSB_ExFreePool(urb);

			} else {
				ntStatus = STATUS_INSUFFICIENT_RESOURCES;
				BULKUSB_KdPrint( DBGLVL_HIGH,("BulkUsb_AbortPipes() FAILED urb alloc\n" ));
				break;
			}


			if (!(NT_SUCCESS(ntStatus))) {
				// if we failed, dump out
#if DBG
				if ( gpDbg )
					gpDbg->PipeErrorCount++;
#endif
				break;
			}
			else {
				PipeInfo->fPipeOpened = FALSE; // mark the pipe 'closed'

				deviceExtension->OpenPipeCount--;
#if DBG
				if ( gpDbg )
					gpDbg->AbortPipeCount++;
#endif


			}

		} // end, if pipe open

        pInf += sizeof ( BULKUSB_PIPEINFO );

	} // end, for all pipes


    return ntStatus;
}



BOOLEAN
BulkUsb_CanAcceptIoRequests(
    IN PDEVICE_OBJECT DeviceObject
    )
/*++

Routine Description:

  Check device extension status flags; 

     Can't accept a new io request if device:
      1) is removed, 
      2) has never been started, 
      3) is stopped,
      4) has a remove request pending, or
      5) has a stop device pending


Arguments:

    DeviceObject - pointer to the device object for this instance of the 82930
                    device.


Return Value:

    return TRUE if can accept new io requests, else FALSE

--*/
{
    PDEVICE_EXTENSION deviceExtension;
	BOOLEAN fCan = FALSE;

    deviceExtension = DeviceObject->DeviceExtension;

	//flag set when processing IRP_MN_REMOVE_DEVICE
    if ( !deviceExtension->DeviceRemoved &&
		 // device must be started( enabled )
		 deviceExtension->DeviceStarted &&
 		 // flag set when driver has answered success to IRP_MN_QUERY_REMOVE_DEVICE
		 !deviceExtension->RemoveDeviceRequested &&
		 // flag set when driver has answered success to IRP_MN_QUERY_STOP_DEVICE
		 !deviceExtension->StopDeviceRequested ){
			fCan = TRUE;
	}

    BULKUSB_KdPrintCond( DBGLVL_MAXIMUM, !fCan, ("**** FALSE return from BulkUsb_CanAcceptIoRequests()!\n"));

	return fCan;
}