Endpoint mismatch in FreeRTOS_MatchingEndpoint (#1239)

* Match source IP to an endpoint on same netmask

* Add Unit test

* Remove used argument from the unused variables cast

---------

Co-authored-by: Ravi Teja Darbha <rdarbha.bu.edu>
Co-authored-by: Tony Josi <tonyjosi@amazon.com>

Author: ravitd

source/FreeRTOS_Routing.c

@@ -658,10 +658,11 @@ struct xIPv6_Couple
  * @brief Check IP-type, IP- and MAC-address found in the network packet.
  */
     #define rMATCH_IP_ADDR      0   /**< Find an endpoint with a matching IP-address. */
-    #define rMATCH_IPv6_TYPE    1   /**< Find an endpoint with a matching IPv6 type (both global or non global). */
-    #define rMATCH_MAC_ADDR     2   /**< Find an endpoint with a matching MAC-address. */
-    #define rMATCH_IP_TYPE      3   /**< Find an endpoint with a matching IP-type, v4 or v6. */
-    #define rMATCH_COUNT        4   /**< The number of methods. */
+    #define rMATCH_NETMASK      1   /**< Find an endpoint with a matching NetMask. */
+    #define rMATCH_IPv6_TYPE    2   /**< Find an endpoint with a matching IPv6 type (both global or non global). */
+    #define rMATCH_MAC_ADDR     3   /**< Find an endpoint with a matching MAC-address. */
+    #define rMATCH_IP_TYPE      4   /**< Find an endpoint with a matching IP-type, v4 or v6. */
+    #define rMATCH_COUNT        5   /**< The number of methods. */
 
     NetworkEndPoint_t * pxEasyFit( const NetworkInterface_t * pxNetworkInterface,
                                    const uint16_t usFrameType,
@@ -688,15 +689,14 @@ struct xIPv6_Couple
     {
         NetworkEndPoint_t * pxEndPoint;
         NetworkEndPoint_t * pxReturn = NULL;
-        /* endpoints found for IP-type, IP-address, and MAC-address. */
-        NetworkEndPoint_t * pxFound[ rMATCH_COUNT ] = { NULL, NULL, NULL, NULL };
-        BaseType_t xCount[ rMATCH_COUNT ] = { 0, 0, 0, 0 };
+        /* endpoints found for IP-type, IP-address, NetMask and MAC-address. */
+        NetworkEndPoint_t * pxFound[ rMATCH_COUNT ] = { NULL, NULL, NULL, NULL, NULL };
+        BaseType_t xCount[ rMATCH_COUNT ] = { 0, 0, 0, 0, 0 };
         BaseType_t xIndex;
         BaseType_t xIsIPv6 = ( usFrameType == ipIPv6_FRAME_TYPE ) ? pdTRUE : pdFALSE;
         BaseType_t xGatewayTarget = pdFALSE;
         BaseType_t xTargetGlobal = pdFALSE;
 
-        ( void ) pxIPAddressFrom;
         ( void ) xGatewayTarget;
         ( void ) xTargetGlobal;
 
@@ -778,6 +778,11 @@ struct xIPv6_Couple
                                 pxFound[ rMATCH_IP_ADDR ] = pxEndPoint;
                                 xCount[ rMATCH_IP_ADDR ]++;
                             }
+                            else if( FreeRTOS_InterfaceEndPointOnNetMask( pxNetworkInterface, pxIPAddressFrom->ulIP_IPv4 ) == pxEndPoint )
+                            {
+                                pxFound[ rMATCH_NETMASK ] = pxEndPoint;
+                                xCount[ rMATCH_NETMASK ]++;
+                            }
                             else
                             {
                                 /* do nothing, coverity happy */
@@ -912,16 +917,11 @@ struct xIPv6_Couple
                         /* coverity[misra_c_2012_rule_11_3_violation] */
                         const ARPPacket_t * pxARPFrame = ( const ARPPacket_t * ) pucEthernetBuffer;
 
-                        if( pxARPFrame->xARPHeader.usOperation == ( uint16_t ) ipARP_REQUEST )
+                        if( ( pxARPFrame->xARPHeader.usOperation == ( uint16_t ) ipARP_REQUEST ) || ( pxARPFrame->xARPHeader.usOperation == ( uint16_t ) ipARP_REPLY ) )
                         {
                             ( void ) memcpy( xIPAddressFrom.xIP_IPv6.ucBytes, pxPacket->xARPPacket.xARPHeader.ucSenderProtocolAddress, sizeof( uint32_t ) );
                             xIPAddressTo.ulIP_IPv4 = pxPacket->xARPPacket.xARPHeader.ulTargetProtocolAddress;
                         }
-                        else if( pxARPFrame->xARPHeader.usOperation == ( uint16_t ) ipARP_REPLY )
-                        {
-                            ( void ) memcpy( xIPAddressTo.xIP_IPv6.ucBytes, pxPacket->xARPPacket.xARPHeader.ucSenderProtocolAddress, sizeof( uint32_t ) );
-                            xIPAddressFrom.ulIP_IPv4 = pxPacket->xARPPacket.xARPHeader.ulTargetProtocolAddress;
-                        }
                         else
                         {
                             /* do nothing, coverity happy */

test/unit-test/FreeRTOS_Routing/FreeRTOS_Routing_utest.c

@@ -2748,6 +2748,56 @@ void test_FreeRTOS_MatchingEndpoint_MatchIPv4Address()
     TEST_ASSERT_EQUAL( &xEndPoint, pxEndPoint );
 }
 
+/**
+ * @brief FreeRTOS_MatchingEndpoint returns the endpoint with same NetMask.
+ *
+ * pxNetworkInterfaces is a global variable using in FreeRTOS_Routing as link list head of all interfaces.
+ * pxNetworkEndPoints is a global variable using in FreeRTOS_Routing as link list head of all endpoints.
+ *
+ * Test step:
+ *  - Create 1 interface and 1 endpoint.
+ *  - Put interface & endpoint into the list.
+ *     - Assign 192.168.123.223 (IPV4_DEFAULT_ADDRESS) to the endpoint.
+ *     - Assign ab:cd:ef:11:22:33 (ucDefaultMACAddress_IPv4) to the endpoint.
+ *     - Attach endpoint to interface.
+ *  - Create a network buffer and set IPv4 packet with source and destination address (IPV4_DEFAULT_GATEWAY),
+ *    and different MAC address.
+ *  - Call FreeRTOS_MatchingEndpoint and check if returned endpoint is same.
+ */
+void test_FreeRTOS_MatchingEndpoint_MatchNetMask()
+{
+    NetworkInterface_t xNetworkInterface;
+    NetworkEndPoint_t xEndPoint;
+    NetworkEndPoint_t * pxEndPoint = NULL;
+    uint8_t * pcNetworkBuffer[ sizeof( ProtocolPacket_t ) + 4 ] __attribute__( ( aligned( 32 ) ) );
+    ProtocolPacket_t * pxProtocolPacket = ( ProtocolPacket_t * ) ( ( uintptr_t ) ( pcNetworkBuffer ) + 2U );
+    const uint8_t ucLocalMACAddress_IPv4[ ipMAC_ADDRESS_LENGTH_BYTES ] = { 0x11, 0x11, 0x11, 0x11, 0x11, 0x11 };
+
+    /* Initialize network interface. */
+    memset( &xNetworkInterface, 0, sizeof( NetworkInterface_t ) );
+    pxNetworkInterfaces = &xNetworkInterface;
+
+    /* Initialize endpoint. */
+    memset( &xEndPoint, 0, sizeof( NetworkEndPoint_t ) );
+    xEndPoint.ipv4_settings.ulIPAddress = IPV4_DEFAULT_ADDRESS;
+    memcpy( xEndPoint.xMACAddress.ucBytes, ucDefaultMACAddress_IPv4, sizeof( ucDefaultMACAddress_IPv4 ) );
+    xEndPoint.pxNetworkInterface = &xNetworkInterface;
+    pxNetworkEndPoints = &xEndPoint;
+
+    /* Initialize network buffer. */
+    memset( pcNetworkBuffer, 0, sizeof( pcNetworkBuffer ) );
+    /* Ethernet part. */
+    memcpy( pxProtocolPacket->xTCPPacket.xEthernetHeader.xDestinationAddress.ucBytes, ucLocalMACAddress_IPv4, sizeof( ucLocalMACAddress_IPv4 ) );
+    memcpy( pxProtocolPacket->xTCPPacket.xEthernetHeader.xSourceAddress.ucBytes, ucLocalMACAddress_IPv4, sizeof( ucLocalMACAddress_IPv4 ) );
+    pxProtocolPacket->xTCPPacket.xEthernetHeader.usFrameType = ipIPv4_FRAME_TYPE;
+    /* IP part. */
+    pxProtocolPacket->xTCPPacket.xIPHeader.ulSourceIPAddress = IPV4_DEFAULT_GATEWAY;
+    pxProtocolPacket->xTCPPacket.xIPHeader.ulDestinationIPAddress = IPV4_DEFAULT_GATEWAY;
+
+    pxEndPoint = FreeRTOS_MatchingEndpoint( &xNetworkInterface, ( const uint8_t * ) ( pxProtocolPacket ) );
+    TEST_ASSERT_EQUAL( &xEndPoint, pxEndPoint );
+}
+
 /**
  * @brief FreeRTOS_MatchingEndpoint returns the endpoint with same MAC address.
  *