The new loopback network interface (#1022)

Co-authored-by: Tony Josi <tonyjosi@amazon.com>

source/portable/NetworkInterface/loopback/loopbackNetworkInterface.c

@@ -0,0 +1,184 @@
+/*
+ * FreeRTOS+TCP V2.3.1
+ * 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.
+ *
+ * http://aws.amazon.com/freertos
+ * http://www.FreeRTOS.org
+ */
+
+/* Standard includes. */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_Sockets.h"
+#include "FreeRTOS_IP_Private.h"
+#include "FreeRTOS_DNS.h"
+#include "FreeRTOS_Routing.h"
+#include "FreeRTOS_ND.h"
+#include "NetworkBufferManagement.h"
+#include "NetworkInterface.h"
+
+#if ( ipconfigUSE_LOOPBACK == 0 )
+    #error Please define ipconfigUSE_LOOPBACK as 1 if you want to use the loop-back interface
+#endif
+
+#define ipICMP_ECHO_REQUEST    ( ( uint8_t ) 8 )
+#define ipICMP_ECHO_REPLY      ( ( uint8_t ) 0 )
+
+/*-----------------------------------------------------------*/
+
+NetworkInterface_t * xLoopbackInterface;
+
+static BaseType_t prvLoopback_Initialise( NetworkInterface_t * pxInterface );
+static BaseType_t prvLoopback_Output( NetworkInterface_t * pxInterface,
+                                      NetworkBufferDescriptor_t * const pxGivenDescriptor,
+                                      BaseType_t bReleaseAfterSend );
+static BaseType_t prvLoopback_GetPhyLinkStatus( NetworkInterface_t * pxInterface );
+
+NetworkInterface_t * pxLoopback_FillInterfaceDescriptor( BaseType_t xEMACIndex,
+                                                         NetworkInterface_t * pxInterface );
+
+/*-----------------------------------------------------------*/
+
+static BaseType_t prvLoopback_Initialise( NetworkInterface_t * pxInterface )
+{
+    /* When returning non-zero, the stack will become active and
+     * start DHCP (in configured) */
+    ( void ) pxInterface;
+    return pdTRUE;
+}
+/*-----------------------------------------------------------*/
+
+#if ( ipconfigCOMPATIBLE_WITH_SINGLE != 0 )
+
+/* Do not call the following function directly. It is there for downward compatibility.
+ * The function FreeRTOS_IPInit() will call it to initialice the interface and end-point
+ * objects.  See the description in FreeRTOS_Routing.h. */
+    NetworkInterface_t * pxFillInterfaceDescriptor( BaseType_t xEMACIndex,
+                                                    NetworkInterface_t * pxInterface )
+    {
+        pxLoopback_FillInterfaceDescriptor( xEMACIndex, pxInterface );
+    }
+
+#endif /* ( ipconfigCOMPATIBLE_WITH_SINGLE != 0 ) */
+/*-----------------------------------------------------------*/
+
+NetworkInterface_t * pxLoopback_FillInterfaceDescriptor( BaseType_t xEMACIndex,
+                                                         NetworkInterface_t * pxInterface )
+{
+/* This function pxLoopback_FillInterfaceDescriptor() adds a network-interface.
+ * Make sure that the object pointed to by 'pxInterface'
+ * is declared static or global, and that it will remain to exist. */
+
+    memset( pxInterface, '\0', sizeof( *pxInterface ) );
+    pxInterface->pcName = "Loopback";                /* Just for logging, debugging. */
+    pxInterface->pvArgument = ( void * ) xEMACIndex; /* Has only meaning for the driver functions. */
+    pxInterface->pfInitialise = prvLoopback_Initialise;
+    pxInterface->pfOutput = prvLoopback_Output;
+    pxInterface->pfGetPhyLinkStatus = prvLoopback_GetPhyLinkStatus;
+
+    FreeRTOS_AddNetworkInterface( pxInterface );
+    xLoopbackInterface = pxInterface;
+
+    return pxInterface;
+}
+/*-----------------------------------------------------------*/
+
+static BaseType_t prvLoopback_GetPhyLinkStatus( NetworkInterface_t * pxInterface )
+{
+    /* This function returns true if the Link Status in the PHY is high. */
+    ( void ) pxInterface;
+    return pdTRUE;
+}
+/*-----------------------------------------------------------*/
+
+static BaseType_t prvLoopback_Output( NetworkInterface_t * pxInterface,
+                                      NetworkBufferDescriptor_t * const pxGivenDescriptor,
+                                      BaseType_t bReleaseAfterSend )
+{
+    NetworkBufferDescriptor_t * pxDescriptor = pxGivenDescriptor;
+
+    ( void ) pxInterface;
+
+    IPPacket_t * a = ( IPPacket_t * ) ( pxDescriptor->pucEthernetBuffer );
+
+    if( a->xEthernetHeader.usFrameType == ipIPv4_FRAME_TYPE )
+    {
+        usGenerateProtocolChecksum( pxDescriptor->pucEthernetBuffer, pxDescriptor->xDataLength, pdTRUE );
+    }
+
+    {
+        MACAddress_t xMACAddress;
+
+        if( pxDescriptor->pxEndPoint->bits.bIPv6 != 0 )
+        {
+            #if ( ipconfigUSE_IPv6 != 0 )
+                if( xIsIPv6Loopback( &( pxDescriptor->xIPAddress ) ) != pdFALSE )
+                {
+                    vNDRefreshCacheEntry( &xMACAddress, &( pxDescriptor->xIPAddress.xIP_IPv6 ), pxDescriptor->pxEndPoint );
+                }
+            #endif
+        }
+        else
+        {
+            #if ( ipconfigUSE_IPv4 != 0 )
+                if( xIsIPv4Loopback( pxDescriptor->xIPAddress.ulIP_IPv4 ) )
+                {
+                    vARPRefreshCacheEntry( &xMACAddress, pxDescriptor->xIPAddress.ulIP_IPv4, pxDescriptor->pxEndPoint );
+                }
+            #endif
+        }
+    }
+
+    if( bReleaseAfterSend == pdFALSE )
+    {
+        NetworkBufferDescriptor_t * pxNewDescriptor =
+            pxDuplicateNetworkBufferWithDescriptor( pxDescriptor, pxDescriptor->xDataLength );
+        pxDescriptor = pxNewDescriptor;
+    }
+
+    if( pxDescriptor != NULL )
+    {
+        IPStackEvent_t xRxEvent;
+
+        xRxEvent.eEventType = eNetworkRxEvent;
+        xRxEvent.pvData = ( void * ) pxDescriptor;
+
+        if( xSendEventStructToIPTask( &xRxEvent, 0u ) != pdTRUE )
+        {
+            vReleaseNetworkBufferAndDescriptor( pxDescriptor );
+            iptraceETHERNET_RX_EVENT_LOST();
+            FreeRTOS_printf( ( "prvEMACRxPoll: Can not queue return packet!\n" ) );
+        }
+    }
+
+    /* The return value is actually ignored by the IP-stack. */
+    return pdTRUE;
+}
+/*-----------------------------------------------------------*/