It helps to get IGMP join and leaves the right way round

Change-Id: I7ada6835fa56aefaa421610ae8a303f2751be2b3

@@ -214,6 +214,10 @@ public class CordMcast {
     }
 
     private void unprovisionGroup(McastRouteInfo info) {
+        if (info.sinks().isEmpty()) {
+            removeSyncedRoute(info);
+        }
+
         if (!info.sink().isPresent()) {
             log.warn("No sink given after sink removed event: {}", info);
             return;
@@ -242,8 +246,6 @@ public class CordMcast {
                 });
 
         flowObjectiveService.next(loc.deviceId(), next);
-
-
     }
 
     private void provisionGroup(McastRouteInfo info) {
@@ -364,6 +366,21 @@ public class CordMcast {
         builder.post(json.toString());
     }
 
+    private void removeSyncedRoute(McastRouteInfo info) {
+        if (syncHost == null) {
+            log.warn("No host configured for synchronization; route will be dropped");
+            return;
+        }
+
+        log.debug("Removing route from other ONOS: {}", info.route());
+
+        WebResource.Builder builder = getClientBuilder(fabricOnosUrl);
+
+        ObjectNode json = codecService.getCodec(McastRoute.class)
+                .encode(info.route(), new AbstractWebResource());
+        builder.delete(json.toString());
+    }
+
     private Integer allocateId() {
         return channels.getAndIncrement();
     }

@@ -275,9 +275,10 @@ public class IgmpSnoop {
             IGMPMembership membership = (IGMPMembership) group;
 
             // TODO allow pulling source from IGMP packet
-            IpAddress source = IpAddress.valueOf("0.0.0.0");
-            if (ssmTranslateTable.containsKey(group.getGaddr())) {
-                source = ssmTranslateTable.get(group.getGaddr());
+            IpAddress source = ssmTranslateTable.get(group.getGaddr());
+            if (source == null) {
+                log.warn("No source found in SSM translate table for {}", group.getGaddr());
+                return;
             }
 
             McastRoute route = new McastRoute(source,
@@ -287,14 +288,13 @@ public class IgmpSnoop {
             if (membership.getRecordType() == IGMPMembership.MODE_IS_INCLUDE ||
                     membership.getRecordType() == IGMPMembership.CHANGE_TO_INCLUDE_MODE) {
 
+                multicastService.removeSink(route, location);
+                // TODO remove route if all sinks are gone
+            } else if (membership.getRecordType() == IGMPMembership.MODE_IS_EXCLUDE ||
+                    membership.getRecordType() == IGMPMembership.CHANGE_TO_EXCLUDE_MODE) {
 
                 multicastService.add(route);
                 multicastService.addSink(route, location);
-
-            } else if (membership.getRecordType() == IGMPMembership.MODE_IS_EXCLUDE ||
-                    membership.getRecordType() == IGMPMembership.CHANGE_TO_EXCLUDE_MODE) {
-                multicastService.removeSink(route, location);
-                // TODO remove route if all sinks are gone
             }
 
         });