Disable ARP/NDP forwarding/flooding

In the scenario where subnets and hosts are configured,
flows for forwarding/flooding should be provisioned.
A copy from the control plane will only cause duplication.
Therefore we are turning that off for now.
We might want to revisit this if we want to support ARP/NDP learning in the future.

Change-Id: I5d8d73c4bacdeabe969ce1ea4e24a4268d853df0
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
index 8f0b7d3..649f52e 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
@@ -25,8 +25,6 @@
 import org.onosproject.incubator.net.neighbour.NeighbourMessageContext;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DeviceId;
-import org.onosproject.net.Host;
-import org.onosproject.net.HostId;
 import org.onosproject.net.host.HostService;
 import org.onosproject.segmentrouting.config.DeviceConfigNotFoundException;
 import org.onosproject.segmentrouting.config.SegmentRoutingAppConfig;
@@ -106,6 +104,9 @@
             MacAddress targetMac = config.getRouterMacForAGatewayIp(pkt.target().getIp4Address());
             sendResponse(pkt, targetMac, hostService);
         } else {
+            // NOTE: Ignore ARP packets except those target for the router
+            //       We will reconsider enabling this when we have host learning support
+            /*
             Set<Host> hosts = hostService.getHostsByIp(pkt.target());
             if (hosts.size() > 1) {
                 log.warn("More than one host with the same ip {}", pkt.target());
@@ -118,6 +119,7 @@
             } else {
                 flood(pkt);
             }
+            */
         }
     }
 
@@ -127,6 +129,9 @@
             Ip4Address hostIpAddress = pkt.sender().getIp4Address();
             srManager.ipHandler.forwardPackets(pkt.inPort().deviceId(), hostIpAddress);
         } else {
+            // NOTE: Ignore ARP packets except those target for the router
+            //       We will reconsider enabling this when we have host learning support
+            /*
             HostId targetHostId = HostId.hostId(pkt.dstMac(), pkt.vlan());
             Host targetHost = hostService.getHost(targetHostId);
             // ARP reply for known hosts. Forward to the host.
@@ -140,6 +145,7 @@
                 }
                 flood(pkt);
             }
+            */
         }
     }