PIBIO_ENGINE_CONTROL_UNIT_PRIVILEGED_FN 回調函式（winbio_adapter.h）

由 Windows 生物特徵框架呼叫，執行廠商定義的控制操作，需要提升權限。 呼叫 EngineAdapterControlUnit 函式，執行廠商定義的控制操作，且不需提升權限。

語法

PIBIO_ENGINE_CONTROL_UNIT_PRIVILEGED_FN PibioEngineControlUnitPrivilegedFn;

HRESULT PibioEngineControlUnitPrivilegedFn(
  [in, out] 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
)
{...}

參數

[in, out] Pipeline

指向與執行作業的生物特徵辨識單元相關聯的 WINBIO_PIPELINE 結構的指標。

[in] ControlCode

一個 ULONG 值，指定廠商定義的操作。

[in] SendBuffer

指標指向一個緩衝區，該緩衝區包含傳送給引擎適配器的控制資訊。 緩衝區的格式與內容由廠商定義。

[in] SendBufferSize

緩衝區的大小（以位元組為單位），由 SendBuffer 參數指定。

[in] ReceiveBuffer

指標指向一個緩衝區，該緩衝區接收引擎適配器回應控制操作回傳的資訊。 緩衝區的格式由廠商定義。

[in] ReceiveBufferSize

由 ReceiveBuffer 參數指定的緩衝區大小（以位元組為單位）。

[out] ReceiveDataSize

指標指向一個變數，該變數接收由 ReceiveBuffer 參數指定，寫入緩衝區的資料大小（以位元組為單位）。

[out] OperationStatus

指標指向一個變數，該變數接收廠商定義的狀態碼，該狀態碼指定控制操作的結果。

返回值

如果函式成功，則會傳回S_OK。 如果函式失敗，它必須傳回下列其中一個 HRESULT 值，以指出錯誤。

備註

你對此函式的實作應與 EngineAdapterControlUnit 函式的實作相同，但執行 ControlCode 參數指定操作需要提升權限。 你負責定義操作範圍，並決定哪些需要更高的權限。

此函式必須檢查 ReceiveBufferSize 參數的值，以確保 ReceiveBuffer 參數指定的緩衝區足夠大以容納回傳的資料。

範例

下列虛擬程式碼顯示此函式的一種可能實作。 此範例不會編譯。 您必須調整它以適應您的目的。

///////////////////////////////////////////////////////////////////////////////
//
// 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;
}

需求

另請參閱

引擎適配控制單元

插件功能