Adds support for receiving Multicast Group addresses

Adds IGMP version 2
Adds 2 function pointers to the network interface struct that handle adding and removing  multicast MAC addresses.
Updates IGMP to use function pointers through the network interface.
Makes the Add/Remove Multicast functions private to NetworkInterface.c They are now used through pointers in the NetworkInterface_t struct.
Improves the SAME70 driver to handle adding/removing muticast MAC addresses

Author: Emil Popov

source/FreeRTOS_DNS_Networking.c

@@ -84,6 +84,11 @@
              * going to be '0' i.e. success. Thus, return value is discarded */
             ( void ) FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_SNDTIMEO, &( uxWriteTimeOut_ticks ), sizeof( TickType_t ) );
             ( void ) FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_RCVTIMEO, &( uxReadTimeOut_ticks ), sizeof( TickType_t ) );
+            #if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+                /* Since this socket may be used for LLMNR or mDNS, set the multicast TTL to 1. */
+                uint8_t ucMulticastTTL = 1;
+                ( void ) FreeRTOS_setsockopt( xSocket, 0, FREERTOS_SO_IP_MULTICAST_TTL, &( ucMulticastTTL ), sizeof( uint8_t ) );
+            #endif
         }
 
         return xSocket;

source/FreeRTOS_IGMP.c

@@ -59,6 +59,9 @@
 #include "FreeRTOS_DNS.h"
 #include "FreeRTOS_Routing.h"
 #include "FreeRTOS_ND.h"
+#if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+    #include "FreeRTOS_IGMP.h"
+#endif
 
 /** @brief Time delay between repeated attempts to initialise the network hardware. */
 #ifndef ipINITIALISATION_RETRY_DELAY
@@ -467,6 +470,26 @@ static void prvProcessIPEventsAndTimers( void )
             /* xQueueReceive() returned because of a normal time-out. */
             break;
 
+            #if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+                case eSocketOptAddMembership:
+                   {
+                       MCastGroupDesc_t * pxMCG = ( MCastGroupDesc_t * ) xReceivedEvent.pvData;
+                       ( void ) vModifyMulticastMembership( pxMCG, eSocketOptAddMembership );
+                       break;
+                   }
+
+                case eSocketOptDropMembership:
+                   {
+                       MCastGroupDesc_t * pxMCG = ( MCastGroupDesc_t * ) xReceivedEvent.pvData;
+                       ( void ) vModifyMulticastMembership( pxMCG, eSocketOptDropMembership );
+                       break;
+                   }
+
+                case eIGMPEvent:
+                    ( void ) vHandleIGMP_Event();
+                    break;
+            #endif /* ( ipconfigSUPPORT_IP_MULTICAST != 0) */
+
         default:
             /* Should not get here. */
             break;
@@ -526,6 +549,11 @@ static void prvIPTask_Initialise( void )
     }
     #endif /* ( ( ipconfigUSE_DNS_CACHE != 0 ) && ( ipconfigUSE_DNS != 0 ) ) */
 
+    /* Init the list that will hold scheduled IGMP reports. */
+    #if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+        ( void ) vIGMP_Init();
+    #endif
+
     /* Initialisation is complete and events can now be processed. */
     xIPTaskInitialised = pdTRUE;
 }
@@ -1980,6 +2008,13 @@ static eFrameProcessingResult_t prvProcessIPPacket( const IPPacket_t * pxIPPacke
                             break;
                     #endif /* ( ipconfigUSE_IPv6 != 0 ) */
 
+                    #if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+                        case ipPROTOCOL_IGMP:
+                            /* The IP packet contained an IGMP frame.  */
+                            eReturn = eProcessIGMPPacket( pxNetworkBuffer );
+                            break;
+                    #endif /* ( ipconfigSUPPORT_IP_MULTICAST != 0 ) */
+
                     case ipPROTOCOL_UDP:
                         /* The IP packet contained a UDP frame. */
 

source/FreeRTOS_IP.c

@@ -55,6 +55,9 @@
 #include "NetworkBufferManagement.h"
 #include "FreeRTOS_Routing.h"
 #include "FreeRTOS_DNS.h"
+#if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+    #include "FreeRTOS_IGMP.h"
+#endif
 /*-----------------------------------------------------------*/
 
 /** @brief 'xAllNetworksUp' becomes pdTRUE as soon as all network interfaces have
@@ -110,6 +113,11 @@ static IPTimer_t xARPTimer;
     static IPTimer_t xDNSTimer;
 #endif
 
+#if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+    /** @brief IGMP timer. Used for sending scheduled IGMP Reports */
+    static IPTimer_t xIGMPTimer;
+#endif
+
 /** @brief As long as not all networks are up, repeat initialisation by calling the
  * xNetworkInterfaceInitialise() function of the interfaces that are not ready. */
 
@@ -176,6 +184,15 @@ TickType_t xCalculateSleepTime( void )
     }
     #endif
 
+    #if ( ipconfigSUPPORT_IP_MULTICAST == 1 )
+    {
+        if( xIGMPTimer.ulRemainingTime < uxMaximumSleepTime )
+        {
+            uxMaximumSleepTime = xIGMPTimer.ulRemainingTime;
+        }
+    }
+    #endif /* ipconfigSUPPORT_IP_MULTICAST */
+
     #if ( ipconfigDNS_USE_CALLBACKS != 0 )
     {
         if( xDNSTimer.bActive != pdFALSE_UNSIGNED )
@@ -312,6 +329,16 @@ void vCheckNetworkTimers( void )
     vSocketListenNextTime( NULL );
     #endif /* ipconfigUSE_TCP == 1 */
 
+    #if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+    {
+        /* Is it time to send any IGMP reports? */
+        if( prvIPTimerCheck( &xIGMPTimer ) != pdFALSE )
+        {
+            ( void ) xSendIGMPEvent();
+        }
+    }
+    #endif /* ipconfigSUPPORT_IP_MULTICAST != 0 */
+
     /* Is it time to trigger the repeated NetworkDown events? */
     if( xAllNetworksUp == pdFALSE )
     {
@@ -412,6 +439,20 @@ void vARPTimerReload( TickType_t xTime )
 
 /*-----------------------------------------------------------*/
 
+#if ( ipconfigSUPPORT_IP_MULTICAST != 0 )
+
+/**
+ * @brief Reload the IGMP timer.
+ *
+ * @param[in] xIgmpTickTime: The reload value.
+ */
+    void vIGMPTimerReload( TickType_t xIgmpTickTime )
+    {
+        prvIPTimerReload( &xIGMPTimer, pdMS_TO_TICKS( ipIGMP_TIMER_PERIOD_MS ) );
+    }
+#endif /* ipconfigSUPPORT_IP_MULTICAST */
+/*-----------------------------------------------------------*/
+
 #if ( ipconfigDNS_USE_CALLBACKS != 0 )
 
 /**