Milestone 5: deliver embedded RDP sessions and lifecycle hardening

third_party/FreeRDP/channels/echo/client/echo_main.c

@@ -0,0 +1,93 @@
+/**
+ * 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, nullptr);
+}
+
+/**
+ * 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,
+	                                                       nullptr, /* Open */
+	                                                       echo_on_close, nullptr };
+
+/**
+ * Function description
+ *
+ * @return 0 on success, otherwise a Win32 error code
+ */
+FREERDP_ENTRY_POINT(UINT VCAPITYPE 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, nullptr, nullptr);
+}