readwrite.cpp

Programming the Microsoft Windows driver model.2nd 随书光盘。内有很多作者送的实用工具和随书源码。WDM编程

			return;				// defer notification until IRP finishes
			}					// cancel poll
		KeReleaseSpinLock(&pdx->polllock, oldirql);
		}						// losing power

	// No need to cancel the poll, so notify power management code immediately

	GenericSaveRestoreComplete(context);
	}							// SaveContext

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS SendAwaitUrb(PDEVICE_OBJECT fdo, PURB urb)
	{							// SendAwaitUrb
	PAGED_CODE();
	ASSERT(KeGetCurrentIrql() == PASSIVE_LEVEL);
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	KEVENT event;
	KeInitializeEvent(&event, NotificationEvent, FALSE);

	IO_STATUS_BLOCK iostatus;
	PIRP Irp = IoBuildDeviceIoControlRequest(IOCTL_INTERNAL_USB_SUBMIT_URB,
		pdx->LowerDeviceObject, NULL, 0, NULL, 0, TRUE, &event, &iostatus);

	if (!Irp)
		{
		KdPrint((DRIVERNAME " - Unable to allocate IRP for sending URB\n"));
		return STATUS_INSUFFICIENT_RESOURCES;
		}

	PIO_STACK_LOCATION stack = IoGetNextIrpStackLocation(Irp);
	stack->Parameters.Others.Argument1 = (PVOID) urb;
	NTSTATUS status = IoCallDriver(pdx->LowerDeviceObject, Irp);
	if (status == STATUS_PENDING)
		{
		KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
		status = iostatus.Status;
		}
	return status;
	}							// SendAwaitUrb

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS StartDevice(PDEVICE_OBJECT fdo, PCM_PARTIAL_RESOURCE_LIST raw, PCM_PARTIAL_RESOURCE_LIST translated)
	{							// StartDevice
	PAGED_CODE();
	NTSTATUS status;
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	URB urb;					// URB for use in this subroutine

	// Read our device descriptor. The only real purpose to this would be to find out how many
	// configurations there are so we can read their descriptors. In this simplest of examples,
	// there's only one configuration.

	UsbBuildGetDescriptorRequest(&urb, sizeof(_URB_CONTROL_DESCRIPTOR_REQUEST), USB_DEVICE_DESCRIPTOR_TYPE,
		0, 0, &pdx->dd, NULL, sizeof(pdx->dd), NULL);
	status = SendAwaitUrb(fdo, &urb);
	if (!NT_SUCCESS(status))
		{
		KdPrint((DRIVERNAME " - Error %X trying to read device descriptor\n", status));
		return status;
		}

	ASSERT(pdx->dd.bNumConfigurations == 1); // only expect one configuration

	MSGUSBSTRING(fdo, DRIVERNAME " - Configuring device from %ws\n", pdx->dd.iManufacturer);
	MSGUSBSTRING(fdo, DRIVERNAME " - Product is %ws\n", pdx->dd.iProduct);
	MSGUSBSTRING(fdo, DRIVERNAME " - Serial number is %ws\n", pdx->dd.iSerialNumber);

	// Read the descriptor of the first configuration. This requires two steps. The first step
	// reads the fixed-size configuration descriptor alone. The second step reads the
	// configuration descriptor plus all imbedded interface and endpoint descriptors.

	USB_CONFIGURATION_DESCRIPTOR tcd;
	UsbBuildGetDescriptorRequest(&urb, sizeof(_URB_CONTROL_DESCRIPTOR_REQUEST), USB_CONFIGURATION_DESCRIPTOR_TYPE,
		0, 0, &tcd, NULL, sizeof(tcd), NULL);
	status = SendAwaitUrb(fdo, &urb);
	if (!NT_SUCCESS(status))
		{
		KdPrint((DRIVERNAME " - Error %X trying to read configuration descriptor 1\n", status));
		return status;
		}

	ULONG size = tcd.wTotalLength;
	PUSB_CONFIGURATION_DESCRIPTOR pcd = (PUSB_CONFIGURATION_DESCRIPTOR) ExAllocatePool(NonPagedPool, size);
	if (!pcd)
		{
		KdPrint((DRIVERNAME " - Unable to allocate %X bytes for configuration descriptor\n", size));
		return STATUS_INSUFFICIENT_RESOURCES;
		}

	__try
		{
		UsbBuildGetDescriptorRequest(&urb, sizeof(_URB_CONTROL_DESCRIPTOR_REQUEST), USB_CONFIGURATION_DESCRIPTOR_TYPE,
			0, 0, pcd, NULL, size, NULL);
		status = SendAwaitUrb(fdo, &urb);
		if (!NT_SUCCESS(status))
			{
			KdPrint((DRIVERNAME " - Error %X trying to read configuration descriptor 1\n", status));
			return status;
			}
                                   
		MSGUSBSTRING(fdo, DRIVERNAME " - Selecting configuration named %ws\n", pcd->iConfiguration);

		// Locate the descriptor for the one and only interface we expect to find

		PUSB_INTERFACE_DESCRIPTOR pid = USBD_ParseConfigurationDescriptorEx(pcd, pcd,
			-1, -1, -1, -1, -1);
		ASSERT(pid);
                                   
		MSGUSBSTRING(fdo, DRIVERNAME " - Selecting interface named %ws\n", pid->iInterface);

		// Create a URB to use in selecting a configuration.

		USBD_INTERFACE_LIST_ENTRY interfaces[2] = {
			{pid, NULL},
			{NULL, NULL},		// fence to terminate the array
			};

		PURB selurb = USBD_CreateConfigurationRequestEx(pcd, interfaces);
		if (!selurb)
			{
			KdPrint((DRIVERNAME " - Unable to create configuration request\n"));
			return STATUS_INSUFFICIENT_RESOURCES;
			}

		__try
			{

			// Verify that the interface describes exactly the endpoints we expect

			if (pid->bNumEndpoints != 1)
				{
				KdPrint((DRIVERNAME " - %d is the wrong number of endpoints\n", pid->bNumEndpoints));
				return STATUS_DEVICE_CONFIGURATION_ERROR;
				}

			PUSB_ENDPOINT_DESCRIPTOR ped = (PUSB_ENDPOINT_DESCRIPTOR) pid;
			ped = (PUSB_ENDPOINT_DESCRIPTOR) USBD_ParseDescriptors(pcd, tcd.wTotalLength, ped, USB_ENDPOINT_DESCRIPTOR_TYPE);
			if (!ped || ped->bEndpointAddress != 0x82 || ped->bmAttributes != USB_ENDPOINT_TYPE_INTERRUPT || ped->wMaxPacketSize != 4)
				{
				KdPrint((DRIVERNAME " - Endpoint has wrong attributes\n"));
				return STATUS_DEVICE_CONFIGURATION_ERROR;
				}
			++ped;

			PUSBD_INTERFACE_INFORMATION pii = interfaces[0].Interface;
			ASSERT(pii->NumberOfPipes == pid->bNumEndpoints);

			// Submit the set-configuration request

			status = SendAwaitUrb(fdo, selurb);
			if (!NT_SUCCESS(status))
				{
				KdPrint((DRIVERNAME " - Error %X trying to select configuration\n", status));
				return status;
				}

			// Save the configuration and pipe handles

			pdx->hconfig = selurb->UrbSelectConfiguration.ConfigurationHandle;
			pdx->hintpipe = pii->Pipes[0].PipeHandle;

			// Transfer ownership of the configuration descriptor to the device extension
			
			pdx->pcd = pcd;
			pcd = NULL;

			// Begin polling the interrupt endpoint

			StartInterruptUrb(pdx);
			}
		__finally
			{
			ExFreePool(selurb);
			}

		}
	__finally
		{
		if (pcd)
			ExFreePool(pcd);
		}

	return STATUS_SUCCESS;
	}							// StartDevice

///////////////////////////////////////////////////////////////////////////////
// This function issues a read to the interrupt pipe.

#pragma LOCKEDCODE

NTSTATUS StartInterruptUrb(PDEVICE_EXTENSION pdx)
	{							// StartInterruptUrb

	// If the interrupt polling IRP is currently running, don't try to start
	// it again.

	BOOLEAN startirp;
	KIRQL oldirql;
	KeAcquireSpinLock(&pdx->polllock, &oldirql);
	if (pdx->pollpending)
		startirp = FALSE;
	else
		startirp = TRUE, pdx->pollpending = TRUE;
	KeReleaseSpinLock(&pdx->polllock, oldirql);

	if (!startirp)
		return STATUS_DEVICE_BUSY;	// already pending

	PIRP Irp = pdx->PollingIrp;
	PURB urb = pdx->PollingUrb;
	ASSERT(Irp && urb);

	// Acquire the remove lock so we can't remove the lower device while the IRP
	// is still active.

	NTSTATUS status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
	if (!NT_SUCCESS(status))
		{
		pdx->pollpending = 0;
		return status;
		}

	// Initialize the URB we use for reading the interrupt pipe

	UsbBuildInterruptOrBulkTransferRequest(urb, sizeof(_URB_BULK_OR_INTERRUPT_TRANSFER),
		pdx->hintpipe, &pdx->intdata, NULL, 4, USBD_TRANSFER_DIRECTION_IN | USBD_SHORT_TRANSFER_OK, NULL);

	// Install "OnInterrupt" as the completion routine for the polling IRP.
	
	IoSetCompletionRoutine(Irp, (PIO_COMPLETION_ROUTINE) OnInterrupt, pdx, TRUE, TRUE, TRUE);

	// Initialize the IRP for an internal control request

	PIO_STACK_LOCATION stack = IoGetNextIrpStackLocation(Irp);
	stack->MajorFunction = IRP_MJ_INTERNAL_DEVICE_CONTROL;
	stack->Parameters.DeviceIoControl.IoControlCode = IOCTL_INTERNAL_USB_SUBMIT_URB;
	stack->Parameters.Others.Argument1 = urb;

	// This IRP might have been cancelled the last time it was used, in which case
	// the cancel flag will still be on. Clear it to prevent USBD from thinking that it's
	// been cancelled again! A better way to do this would be to call IoReuseIrp,
	// but that function is not available in Win98/Me, and I thought it better to
	// avoid requiring WDMSTUB for just that one function.

	Irp->Cancel = FALSE;

	return IoCallDriver(pdx->LowerDeviceObject, Irp);
	}							// StartInterruptUrb

///////////////////////////////////////////////////////////////////////////////
// This function cancels our outstanding interrupt read

#pragma LOCKEDCODE

VOID StopInterruptUrb(PDEVICE_EXTENSION pdx)
	{							// StopInterruptUrb
	if (pdx->pollpending)
		IoCancelIrp(pdx->PollingIrp);
	}							// StopInterruptUrb

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

VOID StopDevice(IN PDEVICE_OBJECT fdo, BOOLEAN oktouch /* = FALSE */)
	{							// StopDevice
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	// Cancel the interrupt polling URB in case it's currently active

	StopInterruptUrb(pdx);

	// If it's okay to touch our hardware (i.e., we're processing an IRP_MN_STOP_DEVICE),
	// deconfigure the device.
	
	if (oktouch)
		{						// deconfigure device
		URB urb;
		UsbBuildSelectConfigurationRequest(&urb, sizeof(_URB_SELECT_CONFIGURATION), NULL);
		NTSTATUS status = SendAwaitUrb(fdo, &urb);
		if (!NT_SUCCESS(status))
			KdPrint((DRIVERNAME " - Error %X trying to deconfigure device\n", status));
		}						// deconfigure device

	if (pdx->pcd)
		ExFreePool(pdx->pcd);
	pdx->pcd = NULL;
	}							// StopDevice