/**

 * 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.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <stdio.h>

#include <stdlib.h>

#include <winpr/crt.h>

#include <winpr/stream.h>

#include "echo_main.h"

#include <freerdp/channels/log.h>

#define TAG CHANNELS_TAG("echo.client")

typedef struct _ECHO_LISTENER_CALLBACK ECHO_LISTENER_CALLBACK;

struct _ECHO_LISTENER_CALLBACK

{

	IWTSListenerCallback iface;

	IWTSPlugin* plugin;

	IWTSVirtualChannelManager* channel_mgr;

};

typedef struct _ECHO_CHANNEL_CALLBACK ECHO_CHANNEL_CALLBACK;

struct _ECHO_CHANNEL_CALLBACK

{

	IWTSVirtualChannelCallback iface;

	IWTSPlugin* plugin;

	IWTSVirtualChannelManager* channel_mgr;

	IWTSVirtualChannel* channel;

};

typedef struct _ECHO_PLUGIN ECHO_PLUGIN;

struct _ECHO_PLUGIN

{

	IWTSPlugin iface;

	ECHO_LISTENER_CALLBACK* listener_callback;

	IWTSListener* listener;

};

/**

 * Function description

 *

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

 */

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

{

	ECHO_CHANNEL_CALLBACK* callback = (ECHO_CHANNEL_CALLBACK*)pChannelCallback;

	BYTE* pBuffer = Stream_Pointer(data);

	UINT32 cbSize = Stream_GetRemainingLength(data);

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

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

}

/**

 * Function description

 *

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

 */

static UINT echo_on_close(IWTSVirtualChannelCallback* pChannelCallback)

{

	ECHO_CHANNEL_CALLBACK* callback = (ECHO_CHANNEL_CALLBACK*)pChannelCallback;

	free(callback);

	return CHANNEL_RC_OK;

}

/**

 * Function description

 *

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

 */

static UINT echo_on_new_channel_connection(IWTSListenerCallback* pListenerCallback,

                                           IWTSVirtualChannel* pChannel, BYTE* Data, BOOL* pbAccept,

                                           IWTSVirtualChannelCallback** ppCallback)

{

	ECHO_CHANNEL_CALLBACK* callback;

	ECHO_LISTENER_CALLBACK* listener_callback = (ECHO_LISTENER_CALLBACK*)pListenerCallback;

	callback = (ECHO_CHANNEL_CALLBACK*)calloc(1, sizeof(ECHO_CHANNEL_CALLBACK));

	if (!callback)

	{

		WLog_ERR(TAG, "calloc failed!");

		return CHANNEL_RC_NO_MEMORY;

	}

	callback->iface.OnDataReceived = echo_on_data_received;

	callback->iface.OnClose = echo_on_close;

	callback->plugin = listener_callback->plugin;

	callback->channel_mgr = listener_callback->channel_mgr;

	callback->channel = pChannel;

	*ppCallback = (IWTSVirtualChannelCallback*)callback;

	return CHANNEL_RC_OK;

}

/**

 * Function description

 *

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

 */

static UINT echo_plugin_initialize(IWTSPlugin* pPlugin, IWTSVirtualChannelManager* pChannelMgr)

{

	ECHO_PLUGIN* echo = (ECHO_PLUGIN*)pPlugin;

	echo->listener_callback = (ECHO_LISTENER_CALLBACK*)calloc(1, sizeof(ECHO_LISTENER_CALLBACK));

	if (!echo->listener_callback)

	{

		WLog_ERR(TAG, "calloc failed!");

		return CHANNEL_RC_NO_MEMORY;

	}

	echo->listener_callback->iface.OnNewChannelConnection = echo_on_new_channel_connection;

	echo->listener_callback->plugin = pPlugin;

	echo->listener_callback->channel_mgr = pChannelMgr;

	return pChannelMgr->CreateListener(pChannelMgr, "ECHO", 0, &echo->listener_callback->iface,

	                                   &echo->listener);

}

/**

 * Function description

 *

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

 */

static UINT echo_plugin_terminated(IWTSPlugin* pPlugin)

{

	ECHO_PLUGIN* echo = (ECHO_PLUGIN*)pPlugin;

	if (echo && echo->listener_callback)

	{

		IWTSVirtualChannelManager* mgr = echo->listener_callback->channel_mgr;

		if (mgr)

			IFCALL(mgr->DestroyListener, mgr, echo->listener);

	}

	free(echo);

	return CHANNEL_RC_OK;

}

#ifdef BUILTIN_CHANNELS

#define DVCPluginEntry echo_DVCPluginEntry

#else

#define DVCPluginEntry FREERDP_API DVCPluginEntry

#endif

/**

 * Function description

 *

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

 */

UINT DVCPluginEntry(IDRDYNVC_ENTRY_POINTS* pEntryPoints)

{

	UINT status = CHANNEL_RC_OK;

	ECHO_PLUGIN* echo;

	echo = (ECHO_PLUGIN*)pEntryPoints->GetPlugin(pEntryPoints, "echo");

	if (!echo)

	{

		echo = (ECHO_PLUGIN*)calloc(1, sizeof(ECHO_PLUGIN));

		if (!echo)

		{

			WLog_ERR(TAG, "calloc failed!");

			return CHANNEL_RC_NO_MEMORY;

		}

		echo->iface.Initialize = echo_plugin_initialize;

		echo->iface.Connected = NULL;

		echo->iface.Disconnected = NULL;

		echo->iface.Terminated = echo_plugin_terminated;

		status = pEntryPoints->RegisterPlugin(pEntryPoints, "echo", (IWTSPlugin*)echo);

	}

	return status;

}