// CharFilterDevice.cpp
// Implementation of CharFilterDevice device class
//
// Generated by DriverWizard version DriverStudio 2.6.0 (Build 336)
// Requires Compuware's DriverWorks classes
//

#pragma warning(disable:4065) // Allow switch statement with no cases
		  
#include <vdw.h>
#include <Kwdmfltr.cpp>

#include "CharFilter.h"
#include "CharFilterDevice.h"
#include "..\CharSampleioctl.h"

#pragma hdrstop("CharFilter.pch")

extern KTrace T;			// Global driver trace object	

CharFilterDevice::CharFilterDevice(PDEVICE_OBJECT Pdo, ULONG Unit) :
	KWdmFilterDevice(Pdo, NULL)
{

	// Check constructor status
    if ( ! NT_SUCCESS(m_ConstructorStatus) )
	{
	    return;
	}

	// Remember our unit number
	m_Unit = Unit;

	// Initialize the lower device
	m_Lower.Initialize(this, Pdo);

	NTSTATUS status = AttachFilter(&m_Lower); //Attach the filter
	if(!NT_SUCCESS(status))
	{
		m_ConstructorStatus = status;
		return;
	}

	SetFilterPnpPolicy();
	SetFilterPowerPolicy();

}

CharFilterDevice::~CharFilterDevice()
{
}

NTSTATUS CharFilterDevice::SystemControl(KIrp I) 
{
	return PassThrough(I);
}

NTSTATUS CharFilterDevice::Create(KIrp I)
{
	return PassThrough(I);
}

NTSTATUS CharFilterDevice::Close(KIrp I)
{
	return PassThrough(I);
}

NTSTATUS CharFilterDevice::DeviceControl(KIrp I) 
{
	switch (I.IoctlCode())
	{
		case CHARSAMPLE_IOCTL_800:
		{
			READ_COMPLETION_INFO* pCompInfo = new (NonPagedPool) READ_COMPLETION_INFO;

			// make sure it succeeded
			if ( pCompInfo == NULL )
			{
				return STATUS_INSUFFICIENT_RESOURCES;
			}

			RtlZeroMemory(pCompInfo,sizeof(READ_COMPLETION_INFO));

			// initialize the context structure
			pCompInfo->m_pClass = this;

			pCompInfo->nin=I.IoctlInputBufferSize();
			pCompInfo->cin=new (NonPagedPool) CHAR[pCompInfo->nin];
			if ( pCompInfo->cin == NULL )
			{
				delete pCompInfo;
				return STATUS_INSUFFICIENT_RESOURCES;
			}

			pCompInfo->nout=I.IoctlOutputBufferSize();
			pCompInfo->cout=new (NonPagedPool) CHAR[pCompInfo->nout];
			if ( pCompInfo->cout == NULL )
			{
				delete pCompInfo->cin;
				delete pCompInfo;
				return STATUS_INSUFFICIENT_RESOURCES;
			}
			strncpy(pCompInfo->cin,(PCHAR)I.IoctlBuffer(),pCompInfo->nin);
			I.FileObject()->FsContext = pCompInfo;

			return PassThrough(I, LinkTo(OnDeviceControlComplete), this);
		}
		default:
			// Unrecognized IOCTL request
			return PassThrough(I);
	}
}
NTSTATUS CharFilterDevice::OnDeviceControlComplete(KIrp I)
{
	T << "CharFilterDevice_Class::OnDeviceControlComplete\n";
	READ_COMPLETION_INFO* pCompInfo = (READ_COMPLETION_INFO*)I.FileObject()->FsContext;
	if ( pCompInfo == NULL ) return I.Status();
	
	strncpy(pCompInfo->cout,(PCHAR)I.IoctlBuffer(),2);
	pCompInfo->cout += 2;
	pCompInfo->nin  -= 1;
 	if (pCompInfo->nin == 0)
	{
		pCompInfo->cout -= pCompInfo->nout;
		strncpy((PCHAR)I.IoctlBuffer(),pCompInfo->cout,pCompInfo->nout);
		I.Information() = pCompInfo->nout;
		if (pCompInfo->cout) delete pCompInfo->cout;
		pCompInfo->cin -= (pCompInfo->nout - 2)/2;
		if (pCompInfo->cin) delete pCompInfo->cin;
		if (pCompInfo) delete pCompInfo;
		I.FileObject()->FsContext = NULL;
		return I.Status();
	}
	else {
		pCompInfo->cin++;
		strncpy((PCHAR)I.IoctlBuffer(),pCompInfo->cin,1);
		PassThrough(I, LinkTo(OnDeviceControlComplete), this);
		return STATUS_MORE_PROCESSING_REQUIRED;
	}
}