// Main program for filter driver
// Copyright (C) 1999 by Walter Oney
// All rights reserved

#include "stddcls.h"
#include "driver.h"

NTSTATUS AddDevice(IN PDRIVER_OBJECT DriverObject, IN PDEVICE_OBJECT pdo);
VOID DriverUnload(IN PDRIVER_OBJECT fido);
NTSTATUS DispatchAny(IN PDEVICE_OBJECT fido, IN PIRP Irp);
NTSTATUS DispatchPower(IN PDEVICE_OBJECT fido, IN PIRP Irp);
NTSTATUS DispatchPnp(IN PDEVICE_OBJECT fido, IN PIRP Irp);
NTSTATUS DispatchWmi(IN PDEVICE_OBJECT fido, IN PIRP Irp);
ULONG GetDeviceTypeToUse(PDEVICE_OBJECT pdo);
NTSTATUS StartDeviceCompletionRoutine(PDEVICE_OBJECT fido, PIRP Irp, PDEVICE_EXTENSION pdx);
NTSTATUS UsageNotificationCompletionRoutine(PDEVICE_OBJECT fido, PIRP Irp, PDEVICE_EXTENSION pdx);

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

#pragma PAGEDCODE

extern "C" NTSTATUS DriverEntry(IN PDRIVER_OBJECT DriverObject,
	IN PUNICODE_STRING RegistryPath)
	{							// DriverEntry
	KdPrint((DRIVERNAME " - Entering DriverEntry: DriverObject %8.8lX\n", DriverObject));

	// Initialize function pointers

	DriverObject->DriverUnload = DriverUnload;
	DriverObject->DriverExtension->AddDevice = AddDevice;

	for (int i = 0; i < arraysize(DriverObject->MajorFunction); ++i)
		DriverObject->MajorFunction[i] = DispatchAny;

	DriverObject->MajorFunction[IRP_MJ_POWER] = DispatchPower;
	DriverObject->MajorFunction[IRP_MJ_PNP] = DispatchPnp;
	
	return STATUS_SUCCESS;
	}							// DriverEntry

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

#pragma PAGEDCODE

VOID DriverUnload(IN PDRIVER_OBJECT DriverObject)
	{							// DriverUnload
	PAGED_CODE();
	KdPrint((DRIVERNAME " - Entering DriverUnload: DriverObject %8.8lX\n", DriverObject));
	}							// DriverUnload

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

NTSTATUS AddDevice(IN PDRIVER_OBJECT DriverObject, IN PDEVICE_OBJECT pdo)
	{							// AddDevice
	PAGED_CODE();
	KdPrint((DRIVERNAME " - Entering AddDevice: DriverObject %8.8lX, pdo %8.8lX\n", DriverObject, pdo));

	NTSTATUS status;

	// Create a device object. Do *not* specify any device characteristics here because
	// some of them will get applied to all drivers in the stack, and it's not up to
	// us as a filter to control any of the propagated attributes (e.g., FILE_DEVICE_SECURE_OPEN).
	// The call to GetDeviceTypeToUse was added in SP-9 to overcome a bug in CDFS.

	PDEVICE_OBJECT fido;
	status = IoCreateDevice(DriverObject, sizeof(DEVICE_EXTENSION), NULL,
		GetDeviceTypeToUse(pdo), 0, FALSE, &fido);
	if (!NT_SUCCESS(status))
		{						// can't create device object
		KdPrint((DRIVERNAME " - IoCreateDevice failed - %X\n", status));
		return status;
		}						// can't create device object
	
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fido->DeviceExtension;

	// From this point forward, any error will have side effects that need to
	// be cleaned up.

	do
		{						// finish initialization
		IoInitializeRemoveLock(&pdx->RemoveLock, 0, 0, 0);
		pdx->DeviceObject = fido;
		pdx->Pdo = pdo;

		// Add our device object to the stack and propagate critical settings
		// from the immediately lower device object

		PDEVICE_OBJECT fdo = IoAttachDeviceToDeviceStack(fido, pdo);
		if (!fdo)
			{					// can't attach								 
			KdPrint((DRIVERNAME " - IoAttachDeviceToDeviceStack failed\n"));
			status = STATUS_DEVICE_REMOVED;
			break;;
			}					// can't attach

		pdx->LowerDeviceObject = fdo;

		// Copy the flags related to I/O buffering from the lower device object so the I/O manager
		// will create the expected data structures for reads and writes.

		fido->Flags |= fdo->Flags & (DO_DIRECT_IO | DO_BUFFERED_IO | DO_POWER_PAGABLE);

		// Clear the "initializing" flag so that we can get IRPs

		fido->Flags &= ~DO_DEVICE_INITIALIZING;
		}						// finish initialization
	while (FALSE);

	if (!NT_SUCCESS(status))
		{					// need to cleanup
		if (pdx->LowerDeviceObject)
			IoDetachDevice(pdx->LowerDeviceObject);
		IoDeleteDevice(fido);
		}					// need to cleanup

	return status;
	}							// AddDevice

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

#pragma LOCKEDCODE

NTSTATUS CompleteRequest(IN PIRP Irp, IN NTSTATUS status, IN ULONG_PTR info)
	{							// CompleteRequest
	Irp->IoStatus.Status = status;
	Irp->IoStatus.Information = info;
	IoCompleteRequest(Irp, IO_NO_INCREMENT);
	return status;
	}							// CompleteRequest

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

#pragma LOCKEDCODE				// make no assumptions about pageability of dispatch fcns

NTSTATUS DispatchAny(IN PDEVICE_OBJECT fido, IN PIRP Irp)
	{							// DispatchAny
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fido->DeviceExtension;
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);

#if DBG
	static char* irpname[] = {
		"IRP_MJ_CREATE",
		"IRP_MJ_CREATE_NAMED_PIPE",
		"IRP_MJ_CLOSE",
		"IRP_MJ_READ",
		"IRP_MJ_WRITE",
		"IRP_MJ_QUERY_INFORMATION",
		"IRP_MJ_SET_INFORMATION",
		"IRP_MJ_QUERY_EA",
		"IRP_MJ_SET_EA",
		"IRP_MJ_FLUSH_BUFFERS",
		"IRP_MJ_QUERY_VOLUME_INFORMATION",
		"IRP_MJ_SET_VOLUME_INFORMATION",
		"IRP_MJ_DIRECTORY_CONTROL",
		"IRP_MJ_FILE_SYSTEM_CONTROL",
		"IRP_MJ_DEVICE_CONTROL",
		"IRP_MJ_INTERNAL_DEVICE_CONTROL",
		"IRP_MJ_SHUTDOWN",
		"IRP_MJ_LOCK_CONTROL",
		"IRP_MJ_CLEANUP",
		"IRP_MJ_CREATE_MAILSLOT",
		"IRP_MJ_QUERY_SECURITY",
		"IRP_MJ_SET_SECURITY",
		"IRP_MJ_POWER",
		"IRP_MJ_SYSTEM_CONTROL",
		"IRP_MJ_DEVICE_CHANGE",
		"IRP_MJ_QUERY_QUOTA",
		"IRP_MJ_SET_QUOTA",
		"IRP_MJ_PNP",
		};

	UCHAR type = stack->MajorFunction;
	if (type >= arraysize(irpname))
		KdPrint((DRIVERNAME " - Unknown IRP, major type %X\n", type));
	else
		KdPrint((DRIVERNAME " - %s\n", irpname[type]));
#endif

	// Pass request down without additional processing

	NTSTATUS status;
	status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
	if (!NT_SUCCESS(status))
		return CompleteRequest(Irp, status, 0);
	IoSkipCurrentIrpStackLocation(Irp);
	status = IoCallDriver(pdx->LowerDeviceObject, Irp);
	IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
	return status;
	}							// DispatchAny

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

NTSTATUS DispatchPower(IN PDEVICE_OBJECT fido, IN PIRP Irp)
	{							// DispatchPower

#if DBG
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
	ULONG fcn = stack->MinorFunction;

	static char* fcnname[] = {
		"IRP_MN_WAIT_WAKE",
		"IRP_MN_POWER_SEQUENCE",
		"IRP_MN_SET_POWER",
		"IRP_MN_QUERY_POWER",
		};

	if (fcn == IRP_MN_SET_POWER || fcn == IRP_MN_QUERY_POWER)
		{
		static char* sysstate[] = {
			"PowerSystemUnspecified",
			"PowerSystemWorking",
			"PowerSystemSleeping1",
			"PowerSystemSleeping2",
			"PowerSystemSleeping3",
			"PowerSystemHibernate",
			"PowerSystemShutdown",
			"PowerSystemMaximum",
			};

		static char* devstate[] = {
			"PowerDeviceUnspecified",
			"PowerDeviceD0",
			"PowerDeviceD1",
			"PowerDeviceD2",
			"PowerDeviceD3",
			"PowerDeviceMaximum",
			};

		ULONG context = stack->Parameters.Power.SystemContext;
		POWER_STATE_TYPE type = stack->Parameters.Power.Type;

		KdPrint((DRIVERNAME " - IRP_MJ_POWER (%s)", fcnname[fcn]));
		if (type == SystemPowerState)
			KdPrint((", SystemPowerState = %s\n", sysstate[stack->Parameters.Power.State.SystemState]));
		else
			KdPrint((", DevicePowerState = %s\n", devstate[stack->Parameters.Power.State.DeviceState]));
		}
	else if (fcn < arraysize(fcnname))
		KdPrint((DRIVERNAME " - IRP_MJ_POWER (%s)\n", fcnname[fcn]));
	else
		KdPrint((DRIVERNAME " - IRP_MJ_POWER (%2.2X)\n", fcn));

#endif // DBG

	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fido->DeviceExtension;
	PoStartNextPowerIrp(Irp);	// must be done while we own the IRP
	NTSTATUS status;
	status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
	if (!NT_SUCCESS(status))
		return CompleteRequest(Irp, status, 0);
	IoSkipCurrentIrpStackLocation(Irp);
	status = PoCallDriver(pdx->LowerDeviceObject, Irp);
	IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
	return status;
	}							// DispatchPower

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

NTSTATUS DispatchPnp(IN PDEVICE_OBJECT fido, IN PIRP Irp)
	{							// DispatchPnp
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
	ULONG fcn = stack->MinorFunction;

	NTSTATUS status;
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fido->DeviceExtension;
	status = IoAcquireRemoveLock(&pdx->RemoveLock, Irp);
	if (!NT_SUCCESS(status))
		return CompleteRequest(Irp, status, 0);

#if DBG 

	static char* pnpname[] = {
		"IRP_MN_START_DEVICE",
		"IRP_MN_QUERY_REMOVE_DEVICE",
		"IRP_MN_REMOVE_DEVICE",
		"IRP_MN_CANCEL_REMOVE_DEVICE",
		"IRP_MN_STOP_DEVICE",
		"IRP_MN_QUERY_STOP_DEVICE",
		"IRP_MN_CANCEL_STOP_DEVICE",
		"IRP_MN_QUERY_DEVICE_RELATIONS",
		"IRP_MN_QUERY_INTERFACE",
		"IRP_MN_QUERY_CAPABILITIES",
		"IRP_MN_QUERY_RESOURCES",
		"IRP_MN_QUERY_RESOURCE_REQUIREMENTS",
		"IRP_MN_QUERY_DEVICE_TEXT",
		"IRP_MN_FILTER_RESOURCE_REQUIREMENTS",
		"",
		"IRP_MN_READ_CONFIG",
		"IRP_MN_WRITE_CONFIG",
		"IRP_MN_EJECT",
		"IRP_MN_SET_LOCK",
		"IRP_MN_QUERY_ID",
		"IRP_MN_QUERY_PNP_DEVICE_STATE",
		"IRP_MN_QUERY_BUS_INFORMATION",
		"IRP_MN_DEVICE_USAGE_NOTIFICATION",
		"IRP_MN_SURPRISE_REMOVAL",
		"IRP_MN_QUERY_LEGACY_BUS_INFORMATION",
		};

	if (fcn < arraysize(pnpname))
		KdPrint((DRIVERNAME " - IRP_MJ_PNP (%s)\n", pnpname[fcn]));
	else
		KdPrint((DRIVERNAME " - IRP_MJ_PNP (%2.2X)\n", fcn));

#endif // DBG

	// Handle usage notification specially in order to track power pageable
	// flag correctly. We need to avoid allowing a non-pageable handler to be
	// layered on top of a pageable handler.

	if (fcn == IRP_MN_DEVICE_USAGE_NOTIFICATION)
		{						// usage notification
		if (!fido->AttachedDevice || (fido->AttachedDevice->Flags & DO_POWER_PAGABLE))
			fido->Flags |= DO_POWER_PAGABLE;
		IoCopyCurrentIrpStackLocationToNext(Irp);
		IoSetCompletionRoutine(Irp, (PIO_COMPLETION_ROUTINE) UsageNotificationCompletionRoutine,
			(PVOID) pdx, TRUE, TRUE, TRUE);
		return IoCallDriver(pdx->LowerDeviceObject, Irp);
		}						// usage notification

	// Handle start device specially in order to correctly inherit
	// FILE_REMOVABLE_MEDIA

	if (fcn == IRP_MN_START_DEVICE)
		{						// device start
		IoCopyCurrentIrpStackLocationToNext(Irp);
		IoSetCompletionRoutine(Irp, (PIO_COMPLETION_ROUTINE) StartDeviceCompletionRoutine,
			(PVOID) pdx, TRUE, TRUE, TRUE);
		return IoCallDriver(pdx->LowerDeviceObject, Irp);
		}						// device start

	// Handle remove device specially in order to cleanup device stack

	if (fcn == IRP_MN_REMOVE_DEVICE)
		{						// remove device
		IoSkipCurrentIrpStackLocation(Irp);
		status = IoCallDriver(pdx->LowerDeviceObject, Irp);
		IoReleaseRemoveLockAndWait(&pdx->RemoveLock, Irp);
		RemoveDevice(fido);
		return status;
		}						// remove device

	// Simply forward any other type of PnP request

	IoSkipCurrentIrpStackLocation(Irp);
	status = IoCallDriver(pdx->LowerDeviceObject, Irp);
	IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
	return status;
	}							// DispatchPnp

///////////////////////////////////////////////////////////////////////////////
// GetDeviceTypeToUse returns the device object type of the next lower device
// object. This helps overcome a bug in some Win2K file systems which expect the
// topmost FiDO in a storage stack to have a VPB and, hence, to have been created
// with a type such as FILE_DEVICE_DISK.

#pragma PAGEDCODE

ULONG GetDeviceTypeToUse(PDEVICE_OBJECT pdo)
	{							// GetDeviceTypeToUse
	PDEVICE_OBJECT ldo = IoGetAttachedDeviceReference(pdo);
	if (!ldo)
		return FILE_DEVICE_UNKNOWN;
	ULONG devtype = ldo->DeviceType;
	ObDereferenceObject(ldo);
	return devtype;
	}							// GetDeviceTypeToUse

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

#pragma PAGEDCODE

VOID RemoveDevice(IN PDEVICE_OBJECT fido)
	{							// RemoveDevice
	PAGED_CODE();
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fido->DeviceExtension;
	NTSTATUS status;

	if (pdx->LowerDeviceObject)
		IoDetachDevice(pdx->LowerDeviceObject);

	IoDeleteDevice(fido);
	}							// RemoveDevice

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

#pragma LOCKEDCODE

NTSTATUS StartDeviceCompletionRoutine(PDEVICE_OBJECT fido, PIRP Irp, PDEVICE_EXTENSION pdx)
	{							// StartDeviceCompletionRoutine
	if (Irp->PendingReturned)
		IoMarkIrpPending(Irp);

	// Inherit FILE_REMOVABLE_MEDIA flag from lower object. This is necessary
	// for a disk filter, but it isn't available until start-device time. Drivers
	// above us may examine the flag as part of their own start-device processing, too.

	if (pdx->LowerDeviceObject->Characteristics & FILE_REMOVABLE_MEDIA)
		fido->Characteristics |= FILE_REMOVABLE_MEDIA;

	IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
	return STATUS_SUCCESS;
	}							// StartDeviceCompletionRoutine

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

#pragma LOCKEDCODE

NTSTATUS UsageNotificationCompletionRoutine(PDEVICE_OBJECT fido, PIRP Irp, PDEVICE_EXTENSION pdx)
	{							// UsageNotificationCompletionRoutine
	if (Irp->PendingReturned)
		IoMarkIrpPending(Irp);

	// If lower driver cleared pageable flag, we must do the same

	if (!(pdx->LowerDeviceObject->Flags & DO_POWER_PAGABLE))
		fido->Flags &= ~DO_POWER_PAGABLE;

	IoReleaseRemoveLock(&pdx->RemoveLock, Irp);
	return STATUS_SUCCESS;
	}							// UsageNotificationCompletionRoutine

#pragma LOCKEDCODE				// force inline functions into nonpaged code