PIBIO_ENGINE_CONTROL_UNIT_PRIVILEGED_FN

Windows Biometric Framework から呼び出され、昇格した特権を必要とするベンダー定義の制御操作を実行します。昇格した特権を必要としないベンダー定義の制御操作を実行するには、EngineAdapterControlUnit 関数を呼び出します。

関数が成功した場合は S_OK を返します。失敗した場合は、エラーを示すために次の HRESULT 値のいずれかを返す必要があります。

この関数の実装は、ControlCode パラメーターで指定される操作の実行に昇格した特権が必要である点を除き、EngineAdapterControlUnit 関数の実装と同一にする必要があります。操作を定義し、どの操作に昇格した特権を必要とするかを決定するのは実装者の責任です。

この関数では、ReceiveBufferSize パラメーターの値を確認し、ReceiveBuffer パラメーターで指定されたバッファーが返されるデータを格納できる十分な大きさであることを確かめる必要があります。

例

次の擬似コードは、この関数の実装例の 1 つを示しています。この例はコンパイルできません。目的に合わせて調整してください。

///////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterControlUnitPrivileged
//
// Purpose:
//      Performs a vendor-defined control operation that requires elevated 
//      privilege.
//
// Parameters:
//      Pipeline            - Pointer to a WINBIO_PIPELINE structure associated 
//                            with the biometric unit performing the operation
//      ControlCode         - Specifies the vendor-defined operation to perform
//      SendBuffer          - Contains the control information sent to the 
//                            engine adapter
//      SendBufferSize      - Size, in bytes, of the buffer specified by the 
//                            SendBuffer parameter
//      ReceiveBuffer       - Receives information returned by the engine adapter
//                            in response to the control operation
//      ReceiveBufferSize   - Size, in bytes, of the buffer specified by the 
//                            ReceiveBuffer parameter.
//      ReceiveDataSize     - Receives the size, in bytes, of the data written to 
//                            the buffer specified by the ReceiveBuffer parameter
//      OperationStatus     - Receives a vendor-defined status code that specifies 
//                            the outcome of the control operation.
//
static HRESULT
WINAPI
EngineAdapterControlUnitPrivileged(
    __inout PWINBIO_PIPELINE Pipeline,
    __in ULONG ControlCode,
    __in PUCHAR SendBuffer,
    __in SIZE_T SendBufferSize,
    __in PUCHAR ReceiveBuffer,
    __in SIZE_T ReceiveBufferSize,
    __out PSIZE_T ReceiveDataSize,
    __out PULONG OperationStatus
    )
{
    HRESULT hr = S_OK;
    BOOL result = TRUE;

    // Verify that pointer arguments are not NULL.
    if (!ARGUMENT_PRESENT(Pipeline) ||
        !ARGUMENT_PRESENT(SendBuffer) ||
        !ARGUMENT_PRESENT(ReceiveBuffer) ||
        !ARGUMENT_PRESENT(ReceiveDataSize) ||
        !ARGUMENT_PRESENT(OperationStatus))
    {
        hr = E_POINTER;
        goto cleanup;
    }

    // Retrieve the context from the pipeline.
    PWINBIO_ENGINE_CONTEXT engineContext = 
           (PWINBIO_ENGINE_CONTEXT)Pipeline->EngineContext;

    // Verify the state of the pipeline.
    if (engineContext == NULL ||
        engineContext->FileHandle == INVALID_HANDLE_VALUE)
    {
        hr = WINBIO_E_INVALID_DEVICE_STATE;
        goto cleanup;
    }

    switch (ControlCode)
    {
    case MY_PRIVILEGED_CTRL_CODE_P1:
        {
            CTRL_CODE_P1_SEND_BUFFER *sendBuffer = (CTRL_CODE_P1_SEND_BUFFER*)SendBuffer;

            // Verify the size of the send buffer.
            if (SendBufferSize < sizeof(CTRL_CODE_P1_SEND_BUFFER))
            {
                hr = E_INVALIDARG;
                break;
            }

            // Perform any other checks that may be required on the buffer 
            // contents. Return E_INVALIDARG if any of the checks fail.
            if (sendBuffer->SomeField != SomeSpecialValue ||
                sendBuffer->SomeOtherField != SomeOtherSpecialValue)
            {
                hr = E_INVALIDARG;
                break;
            }

            if (ReceiveBufferSize < sizeof(CTRL_CODE_P1_RECEIVE_BUFFER))
            {
                hr = E_NOT_SUFFICIENT_BUFFER;
                break;
            }
        }

        // Fall through and perform the control operation after the switch
        // statement. Alternatively, depending on your requirements, you can 
        // perform the control operation here.
        break;

    case MY_PRIVILEGED_CTRL_CODE_P2:
        // Continue testing for other privileged control codes that your
        // adapter supports.
        {
            CTRL_CODE_P2_SEND_BUFFER *sendBuffer = (CTRL_CODE_P2_SEND_BUFFER*)SendBuffer;

            // Verify the size of the send buffer.
            if (SendBufferSize < sizeof(CTRL_CODE_P2_SEND_BUFFER))
            {
                hr = E_INVALIDARG;
                break;
            }

            // Perform any other checks that may be required on the buffer 
            // contents. Return E_INVALIDARG if any of the checks fail.
            if (sendBuffer->SomeField != SomeSpecialValue ||
                sendBuffer->SomeOtherField != SomeOtherSpecialValue)
            {
                hr = E_INVALIDARG;
                break;
            }

            if (ReceiveBufferSize < sizeof(CTRL_CODE_P2_RECEIVE_BUFFER))
            {
                hr = E_NOT_SUFFICIENT_BUFFER;
                break;
            }
        }
        break;

    default:
        // All unrecognized control code values should return an error.
        hr = WINBIO_E_INVALID_CONTROL_CODE;
        break;
    }

    // If control code validation succeeds, perform the control operation. This
    // example assumes that your adapter context structure contains an open
    // handle to a hardware driver. It also assumes that the driver performs
    // overlapped I/O and that a properly initialized OVERLAPPED structure is
    // contained in the engine context.
    if (FAILED(hr))
    {
        goto cleanup;
    }
    result = DeviceIoControl(
                Pipeline->EngineHandle,
                ControlCode,
                SendBuffer,
                (DWORD)SendBufferSize,
                ReceiveBuffer,
                (DWORD)ReceiveBufferSize,
                (LPDWORD)ReceiveDataSize,
                &Pipeline->EngineContext->Overlapped
                );
    if (result == FALSE && GetLastError() == ERROR_IO_PENDING)
    {
        SetLastError(ERROR_SUCCESS);

        result = GetOverlappedResult(
                    Pipeline->EngineHandle,
                    &Pipeline->EngineContext->Overlapped,
                    (LPDWORD)ReceiveDataSize,
                    TRUE
                    );
    }
    *OperationStatus = GetLastError();

    if (!result)
    {
        hr = _AdapterGetHresultFromWin32(*OperationStatus);
    }

cleanup:

    return hr;
}