path: root/wpd/WpdWudfSampleDriver/Queue.cpp

// Queue.cpp : Implementation of CQueue

#include "stdafx.h"
#include "Queue.h"
#include <devioctl.h>
#include <initguid.h>

#include "Queue.tmh"

// Add table used to lookup the Access required for Wpd Commands
BEGIN_WPD_COMMAND_ACCESS_MAP(g_WpdCommandAccessMap)
    DECLARE_WPD_STANDARD_COMMAND_ACCESS_ENTRIES
    // Add any custom commands here e.g.
    // WPD_COMMAND_ACCESS_ENTRY(MyCustomCommand, WPD_COMMAND_ACCESS_READWRITE)
END_WPD_COMMAND_ACCESS_MAP

// This enables use to use VERIFY_WPD_COMMAND_ACCESS to check command access function for us.
DECLARE_VERIFY_WPD_COMMAND_ACCESS;

/******************************************************************************
 * This function calls the WpdBaseDriver to handle the WPD message. In order
 * to do this it does the following:
 *
 *  - Deserializes pBuffer into an IPortableDeviceValues which holds the command
 *    input parameters from the WPD application.
 *  - Creates an IPortableDeviceValues for the results.
 *  - Calls the WpdBaseDriver to handle the message. (The results of this
 *    operation are put into the previously created results IPortableDeviceValues.)
 *  - The results IPortableDeviceValues is then serialized back into pBuffer, making
 *    sure that it does not overrun ulOutputBufferLength.
 *
 *****************************************************************************/
HRESULT CQueue::ProcessWpdMessage(
             ULONG       ControlCode,
    _In_     ContextMap* pClientContextMap,
    _In_     IWDFDevice* pDevice,
    _In_reads_bytes_(ulInputBufferLength) PVOID pInBuffer,
             ULONG       ulInputBufferLength,
    _Out_writes_bytes_to_(ulOutputBufferLength, *pdwBytesWritten) PVOID pOutBuffer,
             ULONG       ulOutputBufferLength,
    _Out_    DWORD*      pdwBytesWritten)
{
    HRESULT                        hr = S_OK;
    CComPtr<IPortableDeviceValues> pParams;
    CComPtr<IPortableDeviceValues> pResults;
    CComPtr<WpdBaseDriver>         pWpdBaseDriver;

    *pdwBytesWritten = 0;

    if (hr == S_OK)
    {
        hr = m_pWpdSerializer->GetIPortableDeviceValuesFromBuffer((BYTE*)pInBuffer,
                                                                  ulInputBufferLength,
                                                                  &pParams);
        CHECK_HR(hr, "Failed to deserialize command parameters from input buffer");
    }

    // Verify that that command was sent with the appropriate access
    if (hr == S_OK)
    {
        hr = VERIFY_WPD_COMMAND_ACCESS(ControlCode, pParams, g_WpdCommandAccessMap);
        CHECK_HR(hr, "Wpd Command was sent with incorrect access flags");
    }

    // Create the WPD results collection
    if (hr == S_OK)
    {
        hr = CoCreateInstance(CLSID_PortableDeviceValues,
                              NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_IPortableDeviceValues,
                              (VOID**)&pResults);
        CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDeviceValues");
    }

    // Insert the client context map as one of this driver's private properties.  This is
    // just a convenient place holder which allows other methods down the chain to
    // access the context map.
    if (hr == S_OK)
    {
        hr = pParams->SetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, pClientContextMap);
        CHECK_HR(hr, "Failed to set PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
    }

    // Insert the IWDFDevice interface as one of this driver's private properties.  This is
    // just a convenient place holder which allows other methods down the chain to
    // access the WUDF Device object.
    if (hr == S_OK)
    {
        hr = pParams->SetIUnknownValue(PRIVATE_SAMPLE_DRIVER_WUDF_DEVICE_OBJECT, pDevice);
        CHECK_HR(hr, "Failed to set PRIVATE_SAMPLE_DRIVER_WUDF_DEVICE_OBJECT");
    }

    // Insert the IWpdSerializer interface as one of this driver's private properties.  This is
    // just a convenient place holder which allows other methods down the chain to
    // access the WPD Serializer object.
    if (hr == S_OK)
    {
        hr = pParams->SetIUnknownValue(PRIVATE_SAMPLE_DRIVER_WPD_SERIALIZER_OBJECT, m_pWpdSerializer);
        CHECK_HR(hr, "Failed to set PRIVATE_SAMPLE_DRIVER_WPD_SERIALIZER_OBJECT");
    }

    // Get the WpdBaseDriver so we can dispatch the message
    if (hr == S_OK)
    {
        hr = GetWpdBaseDriver(pDevice, &pWpdBaseDriver);
        CHECK_HR(hr, "Failed to get WpdBaseDriver");
    }

    if (hr == S_OK)
    {
        hr = pWpdBaseDriver->DispatchWpdMessage(pParams, pResults);
        CHECK_HR(hr, "Failed to handle WPD command");
    }

    if (hr == S_OK)
    {
        hr = m_pWpdSerializer->WriteIPortableDeviceValuesToBuffer(ulOutputBufferLength,
                                                                  pResults,
                                                                  (BYTE*)pOutBuffer,
                                                                  pdwBytesWritten);
        CHECK_HR(hr, "Failed to serialize results to output buffer");
    }

    return hr;
}

/******************************************************************************
 * This method gets the WpdBaseDriver associated with the UMDF device object.
 * The caller should Release *ppWpdBaseDriver when it is done.
 *
 * When this device was created, we assigned the WpdBaseDriver as the context.
 * So, in order to retrieve the correct WpdBaseDriver for this device, we simply
 * get the device context.
 *****************************************************************************/
HRESULT CQueue::GetWpdBaseDriver(
    _In_                          IWDFDevice*     pDevice,
    _Outptr_result_nullonfailure_ WpdBaseDriver** ppWpdBaseDriver)
{
    HRESULT         hr          = S_OK;
    WpdBaseDriver*  pContext    = NULL;

    if((pDevice == NULL) || (ppWpdBaseDriver == NULL))
    {
        hr = E_POINTER;
        CHECK_HR(hr, "Cannot have NULL parameter for pDevice or ppWpdBaseDriver");
    }

    *ppWpdBaseDriver = NULL;

    if(SUCCEEDED(hr))
    {
        hr = pDevice->RetrieveContext((void**)&pContext);
        if(SUCCEEDED(hr))
        {
            if(pContext != NULL)
            {
                pContext->AddRef();
                *ppWpdBaseDriver = pContext;
            }
            else
            {
                hr = E_UNEXPECTED;
                CHECK_HR(hr, "Device context is NULL");
            }
        }
    }

    return hr;
}

// CQueue

STDMETHODIMP_ (void)
CQueue::OnCreateFile(
    _In_    IWDFIoQueue*       pQueue,
    _In_    IWDFIoRequest*     pRequest,
    _In_    IWDFFile*          pFileObject
    )
{
    UNREFERENCED_PARAMETER(pQueue);
    //  This critical section protects the section of code where we
    //  Create the serializer and results interfaces used in handling I/O messages.
    //  We only need to create them once, then we hang on to them for the lifetime of this
    //  queue object.
    CComCritSecLock<CComAutoCriticalSection> Lock(m_CriticalSection);
    HRESULT hr = S_OK;

    // Create the WPD serializer
    if ((hr == S_OK) &&
        (m_pWpdSerializer == NULL))
    {
        hr = CoCreateInstance(CLSID_WpdSerializer,
                              NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_IWpdSerializer,
                              (VOID**)&m_pWpdSerializer);

        CHECK_HR(hr, "Failed to CoCreate CLSID_WpdSerializer");
    }

    // Create the client context map and associate it with the File Object
    // so we can obtain it on a per-client basis.
    if (hr == S_OK)
    {
        ContextMap* pClientContextMap = new ContextMap();

        if(pClientContextMap != NULL)
        {
            hr = pFileObject->AssignContext(this, (void*)pClientContextMap);
            CHECK_HR(hr, "Failed to set client context map");

            // Release the client context map if we cannot set it
            // properly
            if(FAILED(hr))
            {
                pClientContextMap->Release();
                pClientContextMap = NULL;
            }
        }
        else
        {
            hr = E_OUTOFMEMORY;
            CHECK_HR(hr, "Failed to create client context map");
        }
    }

    pRequest->Complete(hr);
    return;
}

STDMETHODIMP_ (void)
CQueue::OnDeviceIoControl(
    _In_    IWDFIoQueue*     pQueue,
    _In_    IWDFIoRequest*   pRequest,
            ULONG            ControlCode,
            SIZE_T           InputBufferSizeInBytes,
            SIZE_T           OutputBufferSizeInBytes
        )
{
    UNREFERENCED_PARAMETER(InputBufferSizeInBytes);
    UNREFERENCED_PARAMETER(OutputBufferSizeInBytes);
    HRESULT hr              = S_OK;
    DWORD   dwBytesWritten  = 0;

    if(IS_WPD_IOCTL(ControlCode))
    {
        BYTE*       pInputBuffer         = NULL;
        SIZE_T      cbInputBuffer        = 0;
        BYTE*       pOutputBuffer        = NULL;
        SIZE_T      cbOutputBuffer       = 0;
        ContextMap* pClientContextMap    = NULL;
        CComPtr<IWDFMemory> pMemoryIn;
        CComPtr<IWDFMemory> pMemoryOut;
        CComPtr<IWDFDevice> pDevice;
        CComPtr<IWDFFile>   pFileObject;

        //
        // Get input memory buffer, the memory object is always returned even if the
        // underlying buffer is NULL
        //
        pRequest->GetInputMemory(&pMemoryIn);
        pInputBuffer = (BYTE*) pMemoryIn->GetDataBuffer(&cbInputBuffer);

        //
        // Get output memory buffer, the memory object is always returned even if the
        // underlying buffer is NULL
        //
        pRequest->GetOutputMemory(&pMemoryOut);
        pOutputBuffer = (BYTE*) pMemoryOut->GetDataBuffer(&cbOutputBuffer);

        // Get the Context map for this client
        pRequest->GetFileObject(&pFileObject);
        if (pFileObject != NULL)
        {
            hr = pFileObject->RetrieveContext((void**)&pClientContextMap);
            CHECK_HR(hr, "Failed to get Contextmap from WDF File Object");

            if (hr == S_OK)
            {
                // Get the device object
                pQueue->GetDevice(&pDevice );
                hr = ProcessWpdMessage(ControlCode,
                                       pClientContextMap,
                                       pDevice,
                                       pInputBuffer,
                                       (DWORD)cbInputBuffer,
                                       pOutputBuffer,
                                       (DWORD)cbOutputBuffer,
                                       &dwBytesWritten);
            }
        }
        else
        {
            hr = E_UNEXPECTED;
            CHECK_HR(hr, "WDF File Object is NULL");
        }
    }
    else
    {
        hr = E_UNEXPECTED;
        CHECK_HR(hr, "Received invalid/unsupported IOCTL code '0x%lx'",ControlCode);
    }

    // Complete the request
    if (hr == S_OK)
    {
        pRequest->CompleteWithInformation(hr, dwBytesWritten);
    }
    else
    {
        pRequest->Complete(hr);
    }

    return;
}

STDMETHODIMP_ (void)
CQueue::OnCleanup(
    _In_    IWDFObject* pWdfObject
    )
{
    // Destroy the client context map
    HRESULT     hr                = S_OK;
    ContextMap* pClientContextMap = NULL;

    hr = pWdfObject->RetrieveContext((void**)&pClientContextMap);
    if((hr == S_OK) && (pClientContextMap != NULL))
    {
        pClientContextMap->Release();
        pClientContextMap = NULL;
    }
}