Restructure Directories and Add required Submodules (FreeRTOS#2)

Submodules:
cbmc/aws-templates-for-cbmc-proofs
test/CMock
source/third_party/http-parser

Directories:
|- cbmc
|- docs
|- source
| |-portable
| |-include
| |-third_party (http-parser)
| |-source_file1.c
| |-source_file2.c
| |-source_file3.c
|
|- tools (if any)
|- test

Author: sarenameas

.gitmodules

@@ -0,0 +1,9 @@
+[submodule "cbmc/aws-templates-for-cbmc-proofs"]
+	path = cbmc/aws-templates-for-cbmc-proofs
+	url = https://github.com/awslabs/aws-templates-for-cbmc-proofs.git
+[submodule "test/CMock"]
+	path = test/CMock
+	url = https://github.com/ThrowTheSwitch/CMock.git
+[submodule "source/third_party/http_parser"]
+	path = source/third_party/http_parser
+	url = https://github.com/nodejs/http-parser.git

cbmc/aws-templates-for-cbmc-proofs

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef TRANSPORT_INTERFACE_H_
+#define TRANSPORT_INTERFACE_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+/**
+ * @brief The NetworkContext is an incomplete type. An implementation of this
+ * interface must define NetworkContext as per the requirements. This context
+ * is passed into the network interface functions.
+ */
+struct NetworkContext;
+typedef struct NetworkContext NetworkContext_t;
+
+/**
+ * @brief Transport interface for receiving data on the network.
+ *
+ * @param[in] pNetworkContext Implementation-defined network context.
+ * @param[in] pBuffer Buffer to receive the data into.
+ * @param[in] bytesToRecv Number of bytes requested from the network.
+ *
+ * @return The number of bytes received or a negative error code.
+ */
+typedef int32_t ( * TransportRecv_t )( const NetworkContext_t * pNetworkContext,
+                                       void * pBuffer,
+                                       size_t bytesToRecv );
+
+/**
+ * @brief Transport interface for sending data over the network.
+ *
+ * @param[in] pNetworkContext Implementation-defined network context.
+ * @param[in] pBuffer Buffer containing the bytes to send over the network stack.
+ * @param[in] bytesToSend Number of bytes to send over the network.
+ *
+ * @return The number of bytes sent or a negative error code.
+ */
+typedef int32_t ( * TransportSend_t )( const NetworkContext_t * pNetworkContext,
+                                       const void * pBuffer,
+                                       size_t bytesToSend );
+
+/**
+ * @brief The transport layer interface.
+ */
+typedef struct TransportInterface
+{
+    TransportRecv_t recv;               /**< Transport receive interface. */
+    TransportSend_t send;               /**< Transport send interface. */
+    NetworkContext_t * pNetworkContext; /**< Implementation-defined network context. */
+} TransportInterface_t;
+
+#endif /* ifndef TRANSPORT_INTERFACE_H_ */