/*--

Copyright (c) 1998. 1999 Microsoft Corporation

Module Name:

kbfiltr.c

Abstract:

Environment:

Kernel mode only.

Notes:

--*/

#include "kbfiltr.h"

NTSTATUS DriverEntry (PDRIVER_OBJECT, PUNICODE_STRING);

#ifdef ALLOC_PRAGMA

#pragma alloc_text (INIT, DriverEntry)

#pragma alloc_text (PAGE, KbFilter_AddDevice)

#pragma alloc_text (PAGE, KbFilter_CreateClose)

#pragma alloc_text (PAGE, KbFilter_InternIoCtl)

#pragma alloc_text (PAGE, KbFilter_Unload)

#pragma alloc_text (PAGE, KbFilter_DispatchPassThrough)

#pragma alloc_text (PAGE, KbFilter_PnP)

#pragma alloc_text (PAGE, KbFilter_Power)

#endif

NTSTATUS

DriverEntry (

IN PDRIVER_OBJECT DriverObject,

IN PUNICODE_STRING RegistryPath

)

/*++

Routine Description:

Initialize the entry points of the driver.

--*/

{

ULONG i;

UNREFERENCED_PARAMETER (RegistryPath);

//

// Fill in all the dispatch entry points with the pass through function

// and the explicitly fill in the functions we are going to intercept

//

for (i = 0; i <= IRP_MJ_MAXIMUM_FUNCTION; i++) {

DriverObject->MajorFunction[i] = KbFilter_DispatchPassThrough;

}

DriverObject->MajorFunction [IRP_MJ_CREATE] =

DriverObject->MajorFunction [IRP_MJ_CLOSE] = KbFilter_CreateClose;

DriverObject->MajorFunction [IRP_MJ_PNP] = KbFilter_PnP; //PNP管理器发送的IRP

DriverObject->MajorFunction [IRP_MJ_POWER] = KbFilter_Power; //POWER管理器发送的IRP

DriverObject->MajorFunction [IRP_MJ_INTERNAL_DEVICE_CONTROL] =

KbFilter_InternIoCtl;

//

// If you are planning on using this function, you must create another

// device object to send the requests to. Please see the considerations

// comments for KbFilter_DispatchPassThrough for implementation details.

//

// DriverObject->MajorFunction [IRP_MJ_DEVICE_CONTROL];

DriverObject->DriverUnload = KbFilter_Unload;

DriverObject->DriverExtension->AddDevice = KbFilter_AddDevice;

return STATUS_SUCCESS;

}

NTSTATUS

KbFilter_AddDevice(

__in PDRIVER_OBJECT Driver,

__in PDEVICE_OBJECT PDO

)

{

PDEVICE_EXTENSION devExt;

IO_ERROR_LOG_PACKET errorLogEntry;

PDEVICE_OBJECT device;

NTSTATUS status = STATUS_SUCCESS;

PAGED_CODE();

//创建设备对象

status = IoCreateDevice(Driver,

sizeof(DEVICE_EXTENSION),

NULL,

FILE_DEVICE_KEYBOARD, //设备对象的类型

0,

FALSE, //FALSE表示非内核模式设备对象

&device

);

if (!NT_SUCCESS(status)) {

return (status);

}

RtlZeroMemory(device->DeviceExtension, sizeof(DEVICE_EXTENSION)); //初始化设备对象扩展

devExt = (PDEVICE_EXTENSION) device->DeviceExtension;

devExt->TopOfStack = IoAttachDeviceToDeviceStack(device, PDO); //挂载过滤驱动，PDO这个底层驱动对象是PNP管理器自动传送的参数

if (devExt->TopOfStack == NULL) {

IoDeleteDevice(device);

return STATUS_DEVICE_NOT_CONNECTED;

}

ASSERT(devExt->TopOfStack); //利用ASSERT这个宏进行对象有效性的判断

devExt->Self = device;

devExt->PDO = PDO;

devExt->DeviceState = PowerDeviceD0;

devExt->SurpriseRemoved = FALSE;

devExt->Removed = FALSE;

devExt->Started = FALSE;

device->Flags |= (DO_BUFFERED_IO | DO_POWER_PAGABLE);

device->Flags &= ~DO_DEVICE_INITIALIZING;

return status;

}

NTSTATUS

KbFilter_Complete(

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp,

__in_opt PVOID Context

)

/*++

Routine Description:

Generic completion routine that allows the driver to send the irp down the

stack, catch it on the way up, and do more processing at the original IRQL.

--*/

{

PKEVENT event;

event = (PKEVENT) Context;

UNREFERENCED_PARAMETER(DeviceObject);

UNREFERENCED_PARAMETER(Irp);

//

// We could switch on the major and minor functions of the IRP to perform

// different functions, but we know that Context is an event that needs

// to be set.

//

KeSetEvent(event, 0, FALSE);

//

// Allows the caller to use the IRP after it is completed

//

return STATUS_MORE_PROCESSING_REQUIRED;

}

NTSTATUS

KbFilter_CreateClose (

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp

)

/*++

Routine Description:

Maintain a simple count of the creates and closes sent against this device

--*/

{

PIO_STACK_LOCATION irpStack;

NTSTATUS status;

PDEVICE_EXTENSION devExt;

PAGED_CODE();

irpStack = IoGetCurrentIrpStackLocation(Irp);

devExt = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

status = Irp->IoStatus.Status;

switch (irpStack->MajorFunction) {

case IRP_MJ_CREATE:

if (NULL == devExt->UpperConnectData.ClassService) {

//

// No Connection yet. How can we be enabled?

//

status = STATUS_INVALID_DEVICE_STATE;

}

else if ( 1 == InterlockedIncrement(&devExt->EnableCount)) { //InterlockedIncrement 和InterlockedDecrement，前者是自加锁，后者是自减锁，两者类似于自增加，自减

// //区别在于，这两个函数起到同步的功能，即只允许一个线程访问

// first time enable here

//

}

else {

//

// More than one create was sent down

//

}

break;

case IRP_MJ_CLOSE:

if (0 == InterlockedDecrement(&devExt->EnableCount)) {

//

// successfully closed the device, do any appropriate work here

//

}

break;

}

Irp->IoStatus.Status = status;

//

// Pass on the create and the close

//

return KbFilter_DispatchPassThrough(DeviceObject, Irp);

}

NTSTATUS

KbFilter_DispatchPassThrough(

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp

)

/*++

Routine Description:

Passes a request on to the lower driver.

Considerations:

If you are creating another device object (to communicate with user mode

via IOCTLs), then this function must act differently based on the intended

device object. If the IRP is being sent to the solitary device object, then

this function should just complete the IRP (becuase there is no more stack

locations below it). If the IRP is being sent to the PnP built stack, then

the IRP should be passed down the stack.

These changes must also be propagated to all the other IRP_MJ dispatch

functions (create, close, cleanup, etc) as well!

--*/

{

PIO_STACK_LOCATION irpStack = IoGetCurrentIrpStackLocation(Irp);

PAGED_CODE();

//

// Pass the IRP to the target

//

IoSkipCurrentIrpStackLocation(Irp);

return IoCallDriver(((PDEVICE_EXTENSION) DeviceObject->DeviceExtension)->TopOfStack, Irp);

}

NTSTATUS

KbFilter_InternIoCtl(

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp

)

/*++

Routine Description:

This routine is the dispatch routine for internal device control requests.

There are two specific control codes that are of interest:

IOCTL_INTERNAL_KEYBOARD_CONNECT:

Store the old context and function pointer and replace it with our own.

This makes life much simpler than intercepting IRPs sent by the RIT and

modifying them on the way back up.

IOCTL_INTERNAL_I8042_HOOK_KEYBOARD:

Add in the necessary function pointers and context values so that we can

alter how the ps/2 keyboard is initialized.

NOTE: Handling IOCTL_INTERNAL_I8042_HOOK_KEYBOARD is *NOT* necessary if

all you want to do is filter KEYBOARD_INPUT_DATAs. You can remove

the handling code and all related device extension fields and

functions to conserve space.

Arguments:

DeviceObject - Pointer to the device object.

Irp - Pointer to the request packet.

Return Value:

Status is returned.

--*/

{

PIO_STACK_LOCATION irpStack;

PDEVICE_EXTENSION devExt;

PINTERNAL_I8042_HOOK_KEYBOARD hookKeyboard;

KEVENT event;

PCONNECT_DATA connectData;

NTSTATUS status = STATUS_SUCCESS;

PAGED_CODE();

devExt = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

Irp->IoStatus.Information = 0;

irpStack = IoGetCurrentIrpStackLocation(Irp);

switch (irpStack->Parameters.DeviceIoControl.IoControlCode) {

//

// Connect a keyboard class device driver to the port driver.

//

case IOCTL_INTERNAL_KEYBOARD_CONNECT:

//

// Only allow one connection.

//

if (devExt->UpperConnectData.ClassService != NULL) {

status = STATUS_SHARING_VIOLATION;

break;

}

else if (irpStack->Parameters.DeviceIoControl.InputBufferLength <

sizeof(CONNECT_DATA)) {

//

// invalid buffer

//

status = STATUS_INVALID_PARAMETER;

break;

}

//

// Copy the connection parameters to the device extension.

//

connectData = ((PCONNECT_DATA)

(irpStack->Parameters.DeviceIoControl.Type3InputBuffer));

devExt->UpperConnectData = *connectData;

//

// Hook into the report chain. Everytime a keyboard packet is reported

// to the system, KbFilter_ServiceCallback will be called

//

/*connectData是一个CONNECT_DATA的结构体变量

ClassDeviceObject指定一个设备对象

ClassService指定服务于设备对象的回调函数

*/

connectData->ClassDeviceObject = devExt->Self;

connectData->ClassService = KbFilter_ServiceCallback;

break;

//

// Disconnect a keyboard class device driver from the port driver.

//

case IOCTL_INTERNAL_KEYBOARD_DISCONNECT:

//

// Clear the connection parameters in the device extension.

//

// devExt->UpperConnectData.ClassDeviceObject = NULL;

// devExt->UpperConnectData.ClassService = NULL;

status = STATUS_NOT_IMPLEMENTED;

break;

//

// Attach this driver to the initialization and byte processing of the

// i8042 (ie PS/2) keyboard. This is only necessary if you want to do PS/2

// specific functions, otherwise hooking the CONNECT_DATA is sufficient

//

case IOCTL_INTERNAL_I8042_HOOK_KEYBOARD:

DebugPrint(("hook keyboard received!\n"));

if (irpStack->Parameters.DeviceIoControl.InputBufferLength <

sizeof(INTERNAL_I8042_HOOK_KEYBOARD)) {

DebugPrint(("InternalIoctl error - invalid buffer length\n"));

status = STATUS_INVALID_PARAMETER;

break;

}

hookKeyboard = (PINTERNAL_I8042_HOOK_KEYBOARD)

irpStack->Parameters.DeviceIoControl.Type3InputBuffer;

//

// Enter our own initialization routine and record any Init routine

// that may be above us. Repeat for the isr hook

//

devExt->UpperContext = hookKeyboard->Context;

//

// replace old Context with our own

//

hookKeyboard->Context = (PVOID) DeviceObject;

if (hookKeyboard->InitializationRoutine) {

devExt->UpperInitializationRoutine =

hookKeyboard->InitializationRoutine;

}

hookKeyboard->InitializationRoutine =

(PI8042_KEYBOARD_INITIALIZATION_ROUTINE)

KbFilter_InitializationRoutine;

if (hookKeyboard->IsrRoutine) {

devExt->UpperIsrHook = hookKeyboard->IsrRoutine;

}

hookKeyboard->IsrRoutine = (PI8042_KEYBOARD_ISR) KbFilter_IsrHook;

//

// Store all of the other important stuff

//

devExt->IsrWritePort = hookKeyboard->IsrWritePort;

devExt->QueueKeyboardPacket = hookKeyboard->QueueKeyboardPacket;

devExt->CallContext = hookKeyboard->CallContext;

status = STATUS_SUCCESS;

break;

//

// These internal ioctls are not supported by the new PnP model.

//

#if 0 // obsolete

case IOCTL_INTERNAL_KEYBOARD_ENABLE:

case IOCTL_INTERNAL_KEYBOARD_DISABLE:

status = STATUS_NOT_SUPPORTED;

break;

#endif // obsolete

//

// Might want to capture these in the future. For now, then pass them down

// the stack. These queries must be successful for the RIT to communicate

// with the keyboard.

//

case IOCTL_KEYBOARD_QUERY_ATTRIBUTES:

case IOCTL_KEYBOARD_QUERY_INDICATOR_TRANSLATION:

case IOCTL_KEYBOARD_QUERY_INDICATORS:

case IOCTL_KEYBOARD_SET_INDICATORS:

case IOCTL_KEYBOARD_QUERY_TYPEMATIC:

case IOCTL_KEYBOARD_SET_TYPEMATIC:

break;

}

if (!NT_SUCCESS(status)) {

Irp->IoStatus.Status = status;

IoCompleteRequest(Irp, IO_NO_INCREMENT);

return status;

}

return KbFilter_DispatchPassThrough(DeviceObject, Irp);

}

NTSTATUS

KbFilter_PnP(

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp

)

/*++

Routine Description:

This routine is the dispatch routine for plug and play irps

Arguments:

DeviceObject - Pointer to the device object.

Irp - Pointer to the request packet.

Return Value:

Status is returned.

--*/

{

PDEVICE_EXTENSION devExt;

PIO_STACK_LOCATION irpStack;

NTSTATUS status = STATUS_SUCCESS;

KIRQL oldIrql;

KEVENT event;

PAGED_CODE();

devExt = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

irpStack = IoGetCurrentIrpStackLocation(Irp);

switch (irpStack->MinorFunction) {

case IRP_MN_START_DEVICE: {

//

// The device is starting.

//

// We cannot touch the device (send it any non pnp irps) until a

// start device has been passed down to the lower drivers.

//

IoCopyCurrentIrpStackLocationToNext(Irp);

KeInitializeEvent(&event,

NotificationEvent,

FALSE

);

IoSetCompletionRoutine(Irp,

(PIO_COMPLETION_ROUTINE) KbFilter_Complete,

&event,

TRUE,

TRUE,

TRUE); // No need for Cancel

status = IoCallDriver(devExt->TopOfStack, Irp);

if (STATUS_PENDING == status) {

KeWaitForSingleObject(

&event,

Executive, // Waiting for reason of a driver

KernelMode, // Waiting in kernel mode

FALSE, // No allert

NULL); // No timeout

status = Irp->IoStatus.Status;

}

if (NT_SUCCESS(status)) {

//

// As we are successfully now back from our start device

// we can do work.

//

devExt->Started = TRUE;

devExt->Removed = FALSE;

devExt->SurpriseRemoved = FALSE;

}

//

// We must now complete the IRP, since we stopped it in the

// completetion routine with MORE_PROCESSING_REQUIRED.

//

Irp->IoStatus.Status = status;

Irp->IoStatus.Information = 0;

IoCompleteRequest(Irp, IO_NO_INCREMENT);

break;

}

case IRP_MN_SURPRISE_REMOVAL:

//

// Same as a remove device, but don't call IoDetach or IoDeleteDevice

//

devExt->SurpriseRemoved = TRUE;

// Remove code here

IoSkipCurrentIrpStackLocation(Irp);

status = IoCallDriver(devExt->TopOfStack, Irp);

break;

case IRP_MN_REMOVE_DEVICE:

devExt->Removed = TRUE;

// remove code here

Irp->IoStatus.Status = STATUS_SUCCESS;

IoSkipCurrentIrpStackLocation(Irp);

status = IoCallDriver(devExt->TopOfStack, Irp);

IoDetachDevice(devExt->TopOfStack);

IoDeleteDevice(DeviceObject);

break;

case IRP_MN_QUERY_REMOVE_DEVICE:

case IRP_MN_QUERY_STOP_DEVICE:

case IRP_MN_CANCEL_REMOVE_DEVICE:

case IRP_MN_CANCEL_STOP_DEVICE:

case IRP_MN_FILTER_RESOURCE_REQUIREMENTS:

case IRP_MN_STOP_DEVICE:

case IRP_MN_QUERY_DEVICE_RELATIONS:

case IRP_MN_QUERY_INTERFACE:

case IRP_MN_QUERY_CAPABILITIES:

case IRP_MN_QUERY_DEVICE_TEXT:

case IRP_MN_QUERY_RESOURCES:

case IRP_MN_QUERY_RESOURCE_REQUIREMENTS:

case IRP_MN_READ_CONFIG:

case IRP_MN_WRITE_CONFIG:

case IRP_MN_EJECT:

case IRP_MN_SET_LOCK:

case IRP_MN_QUERY_ID:

case IRP_MN_QUERY_PNP_DEVICE_STATE:

default:

//

// Here the filter driver might modify the behavior of these IRPS

// Please see PlugPlay documentation for use of these IRPs.

//

IoSkipCurrentIrpStackLocation(Irp);

status = IoCallDriver(devExt->TopOfStack, Irp);

break;

}

return status;

}

NTSTATUS

KbFilter_Power(

__in PDEVICE_OBJECT DeviceObject,

__in PIRP Irp

)

/*++

Routine Description:

This routine is the dispatch routine for power irps Does nothing except

record the state of the device.

Arguments:

DeviceObject - Pointer to the device object.

Irp - Pointer to the request packet.

Return Value:

Status is returned.

--*/

{

PIO_STACK_LOCATION irpStack;

PDEVICE_EXTENSION devExt;

POWER_STATE powerState;

POWER_STATE_TYPE powerType;

PAGED_CODE();

devExt = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

irpStack = IoGetCurrentIrpStackLocation(Irp); //获取当前IRP栈信息

powerType = irpStack->Parameters.Power.Type;

powerState = irpStack->Parameters.Power.State;

switch (irpStack->MinorFunction) {

case IRP_MN_SET_POWER:

/*typedef enum _POWER_STATE_TYPE {

SystemPowerState = 0,

DevicePowerState = 1

} POWER_STATE_TYPE, *PPOWER_STATE_TYPE;*/

//为什么要判断 DvicePowerState 和SystemPowerState 呢 因为发送此类型的IRP请求包的管理器有系统级别的和驱动级别的

if (powerType == DevicePowerState) {

devExt->DeviceState = powerState.DeviceState;

}

case IRP_MN_POWER_SEQUENCE:

case IRP_MN_WAIT_WAKE:

case IRP_MN_QUERY_POWER:

default:

break;

}

PoStartNextPowerIrp(Irp);

IoSkipCurrentIrpStackLocation(Irp);

return PoCallDriver(devExt->TopOfStack, Irp); //PoCallDriver等同于 IocallDriver，针对POWER的请求包处理时，要用PoCallDriver,IocallDriver只针对VISTA系统

}

NTSTATUS

KbFilter_InitializationRoutine(

IN PDEVICE_OBJECT DeviceObject,

IN PVOID SynchFuncContext,

IN PI8042_SYNCH_READ_PORT ReadPort,

IN PI8042_SYNCH_WRITE_PORT WritePort,

OUT PBOOLEAN TurnTranslationOn

)

/*++

Routine Description:

This routine gets called after the following has been performed on the kb

1) a reset

2) set the typematic

3) set the LEDs

i8042prt specific code, if you are writing a packet only filter driver, you

can remove this function

Arguments:

DeviceObject - Context passed during IOCTL_INTERNAL_I8042_HOOK_KEYBOARD

SynchFuncContext - Context to pass when calling Read/WritePort

Read/WritePort - Functions to synchronoulsy read and write to the kb

TurnTranslationOn - If TRUE when this function returns, i8042prt will not

turn on translation on the keyboard

Return Value:

Status is returned.

--*/

{

PDEVICE_EXTENSION devExt;

NTSTATUS status = STATUS_SUCCESS;

devExt = DeviceObject->DeviceExtension;

//

// Do any interesting processing here. We just call any other drivers

// in the chain if they exist. Make Translation is turned on as well

//

if (devExt->UpperInitializationRoutine) {

status = (*devExt->UpperInitializationRoutine) (

devExt->UpperContext,

SynchFuncContext,

ReadPort,

WritePort,

TurnTranslationOn

);

if (!NT_SUCCESS(status)) {

return status;

}

}

*TurnTranslationOn = TRUE;

return status;

}

BOOLEAN

KbFilter_IsrHook(

PDEVICE_OBJECT DeviceObject,

PKEYBOARD_INPUT_DATA CurrentInput,

POUTPUT_PACKET CurrentOutput,

UCHAR StatusByte,

PUCHAR DataByte,

PBOOLEAN ContinueProcessing,

PKEYBOARD_SCAN_STATE ScanState

)

/*++

Routine Description:

This routine gets called at the beginning of processing of the kb interrupt.

i8042prt specific code, if you are writing a packet only filter driver, you

can remove this function

Arguments:

DeviceObject - Our context passed during IOCTL_INTERNAL_I8042_HOOK_KEYBOARD

CurrentInput - Current input packet being formulated by processing all the

interrupts

CurrentOutput - Current list of bytes being written to the keyboard or the

i8042 port.

StatusByte - Byte read from I/O port 60 when the interrupt occurred

DataByte - Byte read from I/O port 64 when the interrupt occurred.

This value can be modified and i8042prt will use this value

if ContinueProcessing is TRUE

ContinueProcessing - If TRUE, i8042prt will proceed with normal processing of

the interrupt. If FALSE, i8042prt will return from the

interrupt after this function returns. Also, if FALSE,

it is this functions responsibilityt to report the input

packet via the function provided in the hook IOCTL or via

queueing a DPC within this driver and calling the

service callback function acquired from the connect IOCTL

Return Value:

Status is returned.

--*/

{

PDEVICE_EXTENSION devExt;

BOOLEAN retVal = TRUE;

devExt = DeviceObject->DeviceExtension;

if (devExt->UpperIsrHook) {

retVal = (*devExt->UpperIsrHook) (

devExt->UpperContext,

CurrentInput,

CurrentOutput,

StatusByte,

DataByte,

ContinueProcessing,

ScanState

);

if (!retVal || !(*ContinueProcessing)) {

return retVal;

}

}

*ContinueProcessing = TRUE;

return retVal;

}

VOID

KbFilter_ServiceCallback(

IN PDEVICE_OBJECT DeviceObject,

IN PKEYBOARD_INPUT_DATA InputDataStart,

IN PKEYBOARD_INPUT_DATA InputDataEnd,

IN OUT PULONG InputDataConsumed

)

/*++

Routine Description:

Called when there are keyboard packets to report to the RIT. You can do

anything you like to the packets. For instance:

o Drop a packet altogether

o Mutate the contents of a packet

o Insert packets into the stream

Arguments:

DeviceObject - Context passed during the connect IOCTL

InputDataStart - First packet to be reported

InputDataEnd - One past the last packet to be reported. Total number of

packets is equal to InputDataEnd - InputDataStart

InputDataConsumed - Set to the total number of packets consumed by the RIT

(via the function pointer we replaced in the connect

IOCTL)

Return Value:

Status is returned.

--*/

{

PDEVICE_EXTENSION devExt;

devExt = (PDEVICE_EXTENSION) DeviceObject->DeviceExtension;

(*(PSERVICE_CALLBACK_ROUTINE) devExt->UpperConnectData.ClassService)(

devExt->UpperConnectData.ClassDeviceObject,

InputDataStart,

InputDataEnd,

InputDataConsumed);

}

VOID

KbFilter_Unload(

__in PDRIVER_OBJECT Driver

)

/*++

Routine Description:

Free all the allocated resources associated with this driver.

Arguments:

DriverObject - Pointer to the driver object.

Return Value:

None.

--*/

{

PAGED_CODE();

UNREFERENCED_PARAMETER(Driver);

ASSERT(NULL == Driver->DeviceObject);

}