Update IPv6 UDP endpoint selection (#853)

* use matching endpoint instead of first endpoint

* update with @htibosch  latest changes

* fix formatting

* fix misra and spellings

* code clean up

.github/lexicon.txt

@@ -1829,6 +1829,7 @@ xipversion
 xisbound
 xiscallingfromiptask
 xisforrx
+xisglobal
 xisinputstream
 xiswaitingarpresolution
 xitemvalue

source/FreeRTOS_UDP_IPv6.c

@@ -73,18 +73,23 @@
 /* _HT_ this is a temporary aid while testing. In case an end-0point is not found,
  * this function will return the first end-point of the required type,
  * either 'ipTYPE_IPv4' or 'ipTYPE_IPv6' */
-extern NetworkEndPoint_t * pxGetEndpoint( BaseType_t xIPType );
+extern NetworkEndPoint_t * pxGetEndpoint( BaseType_t xIPType,
+                                          BaseType_t xIsGlobal );
 
 /**
  * @brief Get the first end point of the type (IPv4/IPv6) from the list
  *        the list of end points.
  *
- * @param[in] xIPType IT type (ipTYPE_IPv6/ipTYPE_IPv4)
+ * @param[in] xIPType IP type (ipTYPE_IPv6/ipTYPE_IPv4)
+ * @param[in] xIsGlobal when pdTRUE, an endpoint with a global address must be
+ *                      returned. When pdFALSE, a local-link endpoint is returned.
+ *                      This only applies to IPv6 endpoints.
  *
  * @returns Pointer to the first end point of the given IP type from the
  *          list of end points.
  */
-NetworkEndPoint_t * pxGetEndpoint( BaseType_t xIPType )
+NetworkEndPoint_t * pxGetEndpoint( BaseType_t xIPType,
+                                   BaseType_t xIsGlobal )
 {
     NetworkEndPoint_t * pxEndPoint;
 
@@ -95,10 +100,16 @@ NetworkEndPoint_t * pxGetEndpoint( BaseType_t xIPType )
         if( xIPType == ( BaseType_t ) ipTYPE_IPv6 )
         {
             if( pxEndPoint->bits.bIPv6 != 0U )
+            {
+                IPv6_Type_t eEndpointType = xIPv6_GetIPType( &( pxEndPoint->ipv6_settings.xIPAddress ) );
+                BaseType_t xEndpointGlobal = ( eEndpointType == eIPv6_Global ) ? pdTRUE : pdFALSE;
+
+                if( xEndpointGlobal == xIsGlobal )
                 {
                     break;
                 }
             }
+        }
         else
         {
             if( pxEndPoint->bits.bIPv6 == 0U )
@@ -130,7 +141,7 @@ static eARPLookupResult_t prvStartLookup( NetworkBufferDescriptor_t * const pxNe
     /* MISRA Ref 11.3.1 [Misaligned access] */
     /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
     /* coverity[misra_c_2012_rule_11_3_violation] */
-    const UDPPacket_t * pxUDPPacket = ( ( UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
+    const UDPPacket_t * pxUDPPacket = ( ( const UDPPacket_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
     if( pxUDPPacket->xEthernetHeader.usFrameType == ipIPv6_FRAME_TYPE )
     {
@@ -140,7 +151,9 @@ static eARPLookupResult_t prvStartLookup( NetworkBufferDescriptor_t * const pxNe
 
         if( pxNetworkBuffer->pxEndPoint == NULL )
         {
-            pxNetworkBuffer->pxEndPoint = pxGetEndpoint( ( BaseType_t ) ipTYPE_IPv6 );
+            IPv6_Type_t eTargetType = xIPv6_GetIPType( &( pxNetworkBuffer->xIPAddress.xIP_IPv6 ) );
+            BaseType_t xIsGlobal = ( eTargetType == eIPv6_Global ) ? pdTRUE : pdFALSE;
+            pxNetworkBuffer->pxEndPoint = pxGetEndpoint( ( BaseType_t ) ipTYPE_IPv6, xIsGlobal );
             FreeRTOS_printf( ( "prvStartLookup: Got an end-point: %s\n", pxNetworkBuffer->pxEndPoint ? "yes" : "no" ) );
         }
 
@@ -337,16 +350,12 @@ void vProcessGeneratedUDPPacket_IPv6( NetworkBufferDescriptor_t * const pxNetwor
         }
         else if( eReturned == eARPCacheMiss )
         {
-            eReturned = prvStartLookup( pxNetworkBuffer, &( xLostBuffer ) );
+            if( pxEndPoint != NULL )
-
-            if( pxNetworkBuffer->pxEndPoint != NULL )
             {
-                vNDSendNeighbourSolicitation( pxNetworkBuffer, &( pxNetworkBuffer->xIPAddress.xIP_IPv6 ) );
+                pxNetworkBuffer->pxEndPoint = pxEndPoint;
-
-                /* pxNetworkBuffer has been sent and released.
-                 * Make sure it won't be used again.. */
-                xLostBuffer = pdTRUE;
             }
+
+            eReturned = prvStartLookup( pxNetworkBuffer, &( xLostBuffer ) );
         }
         else
         {
@@ -426,6 +435,7 @@ BaseType_t xProcessReceivedUDPPacket_IPv6( NetworkBufferDescriptor_t * pxNetwork
     /* Returning pdPASS means that the packet was consumed, released. */
     BaseType_t xReturn = pdPASS;
     FreeRTOS_Socket_t * pxSocket;
+    const UDPPacket_IPv6_t * pxUDPPacket_IPv6;
 
     configASSERT( pxNetworkBuffer != NULL );
     configASSERT( pxNetworkBuffer->pucEthernetBuffer != NULL );
@@ -437,7 +447,7 @@ BaseType_t xProcessReceivedUDPPacket_IPv6( NetworkBufferDescriptor_t * pxNetwork
     /* MISRA Ref 11.3.1 [Misaligned access] */
     /* More details at: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA.md#rule-113 */
     /* coverity[misra_c_2012_rule_11_3_violation] */
-    const UDPPacket_IPv6_t * pxUDPPacket_IPv6 = ( ( UDPPacket_IPv6_t * ) pxNetworkBuffer->pucEthernetBuffer );
+    pxUDPPacket_IPv6 = ( ( UDPPacket_IPv6_t * ) pxNetworkBuffer->pucEthernetBuffer );
 
     /* Caller must check for minimum packet size. */
     pxSocket = pxUDPSocketLookup( usPort );