/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * Echo Virtual Channel Extension

 *

 * Copyright 2013 Christian Hofstaedtler

 * Copyright 2015 Thincast Technologies GmbH

 * Copyright 2015 DI (FH) Martin Haimberger <martin.haimberger@thincast.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <freerdp/config.h>

#include <stdio.h>

#include <stdlib.h>

#include <winpr/crt.h>

#include <winpr/assert.h>

#include <winpr/stream.h>

#include "echo_main.h"

#include <freerdp/client/channels.h>

#include <freerdp/channels/log.h>

#include <freerdp/channels/echo.h>

#define TAG CHANNELS_TAG("echo.client")

typedef struct

{

  GENERIC_DYNVC_PLUGIN baseDynPlugin;

} ECHO_PLUGIN;

/**

 * Function description

 *

 * @return 0 on success, otherwise a Win32 error code

 */

static UINT echo_on_data_received(IWTSVirtualChannelCallback* pChannelCallback, wStream* data)

{

  GENERIC_CHANNEL_CALLBACK* callback = (GENERIC_CHANNEL_CALLBACK*)pChannelCallback;

  const BYTE* pBuffer = Stream_ConstPointer(data);

  const size_t cbSize = Stream_GetRemainingLength(data);

  WINPR_ASSERT(callback);

  WINPR_ASSERT(callback->channel);

  WINPR_ASSERT(callback->channel->Write);

  if (cbSize > UINT32_MAX)

    return ERROR_INVALID_PARAMETER;

  /* echo back what we have received. ECHO does not have any message IDs. */

  return callback->channel->Write(callback->channel, (ULONG)cbSize, pBuffer, NULL);

}

/**

 * Function description

 *

 * @return 0 on success, otherwise a Win32 error code

 */

static UINT echo_on_close(IWTSVirtualChannelCallback* pChannelCallback)

{

  GENERIC_CHANNEL_CALLBACK* callback = (GENERIC_CHANNEL_CALLBACK*)pChannelCallback;

  free(callback);

  return CHANNEL_RC_OK;

}

static const IWTSVirtualChannelCallback echo_callbacks = { echo_on_data_received, NULL, /* Open */

                                                         echo_on_close, NULL };

/**

 * Function description

 *

 * @return 0 on success, otherwise a Win32 error code

 */

FREERDP_ENTRY_POINT(UINT echo_DVCPluginEntry(IDRDYNVC_ENTRY_POINTS* pEntryPoints))

{

  return freerdp_generic_DVCPluginEntry(pEntryPoints, TAG, ECHO_DVC_CHANNEL_NAME,

                                        sizeof(ECHO_PLUGIN), sizeof(GENERIC_CHANNEL_CALLBACK),

                                        &echo_callbacks, NULL, NULL);

}