src/main/java/net/onrc/onos/ofcontroller/bgproute/BgpRoute.java

package net.onrc.onos.ofcontroller.bgproute;

import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import net.floodlightcontroller.core.IFloodlightProviderService;
import net.floodlightcontroller.core.IOFSwitch;
import net.floodlightcontroller.core.IOFSwitchListener;
import net.floodlightcontroller.core.module.FloodlightModuleContext;
import net.floodlightcontroller.core.module.FloodlightModuleException;
import net.floodlightcontroller.core.module.IFloodlightModule;
import net.floodlightcontroller.core.module.IFloodlightService;
import net.floodlightcontroller.core.util.SingletonTask;
import net.floodlightcontroller.packet.Ethernet;
import net.floodlightcontroller.packet.IPv4;
import net.floodlightcontroller.restserver.IRestApiService;
import net.floodlightcontroller.routing.Link;
import net.floodlightcontroller.topology.ITopologyListener;
import net.floodlightcontroller.topology.ITopologyService;
import net.floodlightcontroller.util.MACAddress;
import net.onrc.onos.ofcontroller.bgproute.RibUpdate.Operation;
import net.onrc.onos.ofcontroller.core.IDeviceStorage;
import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IDeviceObject;
import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.ISwitchObject;
import net.onrc.onos.ofcontroller.core.INetMapTopologyService.ITopoLinkService;
import net.onrc.onos.ofcontroller.core.INetMapTopologyService.ITopoSwitchService;
import net.onrc.onos.ofcontroller.core.config.IConfigInfoService;
import net.onrc.onos.ofcontroller.core.internal.DeviceStorageImpl;
import net.onrc.onos.ofcontroller.core.internal.TopoLinkServiceImpl;
import net.onrc.onos.ofcontroller.core.internal.TopoSwitchServiceImpl;
import net.onrc.onos.ofcontroller.flowmanager.IFlowService;
import net.onrc.onos.ofcontroller.linkdiscovery.ILinkDiscovery;
import net.onrc.onos.ofcontroller.linkdiscovery.ILinkDiscovery.LDUpdate;
import net.onrc.onos.ofcontroller.linkdiscovery.ILinkDiscoveryService;
import net.onrc.onos.ofcontroller.proxyarp.IArpRequester;
import net.onrc.onos.ofcontroller.proxyarp.IProxyArpService;
import net.onrc.onos.ofcontroller.topology.ITopologyNetService;
import net.onrc.onos.ofcontroller.topology.Topology;
import net.onrc.onos.ofcontroller.topology.TopologyManager;
import net.onrc.onos.ofcontroller.util.CallerId;
import net.onrc.onos.ofcontroller.util.DataPath;
import net.onrc.onos.ofcontroller.util.Dpid;
import net.onrc.onos.ofcontroller.util.FlowEntryAction;
import net.onrc.onos.ofcontroller.util.FlowEntryActions;
import net.onrc.onos.ofcontroller.util.FlowEntryMatch;
import net.onrc.onos.ofcontroller.util.FlowId;
import net.onrc.onos.ofcontroller.util.FlowPath;
import net.onrc.onos.ofcontroller.util.FlowPathFlags;
import net.onrc.onos.ofcontroller.util.FlowPathType;
import net.onrc.onos.ofcontroller.util.FlowPathUserState;
import net.onrc.onos.ofcontroller.util.IPv4Net;
import net.onrc.onos.ofcontroller.util.Port;
import net.onrc.onos.ofcontroller.util.SwitchPort;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;

import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.openflow.protocol.OFFlowMod;
import org.openflow.protocol.OFMatch;
import org.openflow.protocol.OFPacketOut;
import org.openflow.protocol.OFPort;
import org.openflow.protocol.action.OFAction;
import org.openflow.protocol.action.OFActionOutput;
import org.openflow.util.HexString;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;
import com.google.common.collect.SetMultimap;
import com.google.common.net.InetAddresses;
import com.google.common.util.concurrent.ThreadFactoryBuilder;

public class BgpRoute implements IFloodlightModule, IBgpRouteService,
									ITopologyListener, IArpRequester,
									IOFSwitchListener, IConfigInfoService {

	private final static Logger log = LoggerFactory.getLogger(BgpRoute.class);

	private IFloodlightProviderService floodlightProvider;
	private ITopologyService topologyService;
	private ITopologyNetService topologyNetService;
	private ILinkDiscoveryService linkDiscoveryService;
	private IRestApiService restApi;
	private IProxyArpService proxyArp;
	protected volatile IFlowService flowManagerService;
	private IDeviceStorage deviceStorage;
	private ITopoSwitchService topoSwitchService;

	private IPatriciaTrie<RibEntry> ptree;
	private IPatriciaTrie<Interface> interfacePtrie;
	private BlockingQueue<RibUpdate> ribUpdates;

	private String bgpdRestIp;
	private String routerId;
	private String configFilename = "config.json";

	//We need to identify our flows somehow. But like it says in LearningSwitch.java,
	//the controller/OS should hand out cookie IDs to prevent conflicts.
	private final long APP_COOKIE = 0xa0000000000000L;
	//Cookie for flows that do L2 forwarding within SDN domain to egress routers
	private final long L2_FWD_COOKIE = APP_COOKIE + 1;
	//Cookie for flows in ingress switches that rewrite the MAC address
	private final long MAC_RW_COOKIE = APP_COOKIE + 2;
	//Cookie for flows that setup BGP paths
	private final long BGP_COOKIE = APP_COOKIE + 3;
	//Forwarding uses priority 0, and the mac rewrite entries in ingress switches
	//need to be higher priority than this otherwise the rewrite may not get done
	private final short SDNIP_PRIORITY = 10;
	private final short ARP_PRIORITY = 20;

	private final short BGP_PORT = 179;

	private final int TOPO_DETECTION_WAIT = 2; //seconds

	//Configuration stuff
	private List<String> switches;
	private Map<String, Interface> interfaces;
	private Map<InetAddress, BgpPeer> bgpPeers;
	private SwitchPort bgpdAttachmentPoint;
	private MACAddress bgpdMacAddress;
	private short vlan;

	//True when all switches have connected
	private volatile boolean switchesConnected = false;
	//True when we have a full mesh of shortest paths between gateways
	private volatile boolean topologyReady = false;

	private ArrayList<LDUpdate> linkUpdates;
	private SingletonTask topologyChangeDetectorTask;

	private SetMultimap<InetAddress, RibUpdate> prefixesWaitingOnArp;

	private Map<InetAddress, Path> pathsWaitingOnArp;

	private ExecutorService bgpUpdatesExecutor;

	private Map<InetAddress, Path> pushedPaths;
	private Map<Prefix, Path> prefixToPath;
//	private Multimap<Prefix, PushedFlowMod> pushedFlows;
	private Multimap<Prefix, FlowId> pushedFlowIds;

	private FlowCache flowCache;

	private volatile Topology topology = null;

	private class TopologyChangeDetector implements Runnable {
		@Override
		public void run() {
			log.debug("Running topology change detection task");
			synchronized (linkUpdates) {
				//This is the model the REST API uses to retrieve network graph info
				ITopoLinkService topoLinkService = new TopoLinkServiceImpl();

				List<Link> activeLinks = topoLinkService.getActiveLinks();

				Iterator<LDUpdate> it = linkUpdates.iterator();
				while (it.hasNext()){
					LDUpdate ldu = it.next();
					Link l = new Link(ldu.getSrc(), ldu.getSrcPort(),
							ldu.getDst(), ldu.getDstPort());

					if (activeLinks.contains(l)){
						it.remove();
					}
				}
			}

			if (!topologyReady) {
				if (linkUpdates.isEmpty()){
					//All updates have been seen in network map.
					//We can check if topology is ready
					log.debug("No known changes outstanding. Checking topology now");
					checkStatus();
				}
				else {
					//We know of some link updates that haven't propagated to the database yet
					log.debug("Some changes not found in network map - {} links missing", linkUpdates.size());
					topologyChangeDetectorTask.reschedule(TOPO_DETECTION_WAIT, TimeUnit.SECONDS);
				}
			}
		}
	}

	private void readConfiguration(String configFilename){
		File gatewaysFile = new File(configFilename);
		ObjectMapper mapper = new ObjectMapper();

		try {
			Configuration config = mapper.readValue(gatewaysFile, Configuration.class);

			switches = config.getSwitches();
			interfaces = new HashMap<String, Interface>();
			for (Interface intf : config.getInterfaces()){
				interfaces.put(intf.getName(), intf);
			}
			bgpPeers = new HashMap<InetAddress, BgpPeer>();
			for (BgpPeer peer : config.getPeers()){
				bgpPeers.put(peer.getIpAddress(), peer);
			}

			bgpdAttachmentPoint = new SwitchPort(
					new Dpid(config.getBgpdAttachmentDpid()),
					new Port(config.getBgpdAttachmentPort()));

			bgpdMacAddress = config.getBgpdMacAddress();
			vlan = config.getVlan();
		} catch (JsonParseException e) {
			log.error("Error in JSON file", e);
			System.exit(1);
		} catch (JsonMappingException e) {
			log.error("Error in JSON file", e);
			System.exit(1);
		} catch (IOException e) {
			log.error("Error reading JSON file", e);
			System.exit(1);
		}

		//Populate the interface Patricia Trie
		for (Interface intf : interfaces.values()) {
			Prefix prefix = new Prefix(intf.getIpAddress().getAddress(), intf.getPrefixLength());
			interfacePtrie.put(prefix, intf);
		}
	}

	@Override
	public Collection<Class<? extends IFloodlightService>> getModuleServices() {
		Collection<Class<? extends IFloodlightService>> l
			= new ArrayList<Class<? extends IFloodlightService>>();
		l.add(IBgpRouteService.class);
		l.add(IConfigInfoService.class);
		return l;
	}

	@Override
	public Map<Class<? extends IFloodlightService>, IFloodlightService> getServiceImpls() {
		Map<Class<? extends IFloodlightService>, IFloodlightService> m
			= new HashMap<Class<? extends IFloodlightService>, IFloodlightService>();
		m.put(IBgpRouteService.class, this);
		m.put(IConfigInfoService.class, this);
		return m;
	}

	@Override
	public Collection<Class<? extends IFloodlightService>> getModuleDependencies() {
		Collection<Class<? extends IFloodlightService>> l
			= new ArrayList<Class<? extends IFloodlightService>>();
		l.add(IFloodlightProviderService.class);
		l.add(ITopologyService.class);
		l.add(IRestApiService.class);
		return l;
	}

	@Override
	public void init(FloodlightModuleContext context)
			throws FloodlightModuleException {

		ptree = new PatriciaTrie<RibEntry>(32);
		interfacePtrie = new PatriciaTrie<Interface>(32);

		ribUpdates = new LinkedBlockingQueue<RibUpdate>();

		// Register floodlight provider and REST handler.
		floodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
		topologyService = context.getServiceImpl(ITopologyService.class);
		linkDiscoveryService = context.getServiceImpl(ILinkDiscoveryService.class);
		restApi = context.getServiceImpl(IRestApiService.class);
		flowManagerService = context.getServiceImpl(IFlowService.class);
		proxyArp = context.getServiceImpl(IProxyArpService.class);

		deviceStorage = new DeviceStorageImpl();
		deviceStorage.init("", "");

		linkUpdates = new ArrayList<LDUpdate>();
		ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
		topologyChangeDetectorTask = new SingletonTask(executor, new TopologyChangeDetector());

		topologyNetService = new TopologyManager(context);
		topoSwitchService = new TopoSwitchServiceImpl();

		pathsWaitingOnArp = new HashMap<InetAddress, Path>();
		prefixesWaitingOnArp = Multimaps.synchronizedSetMultimap(
				HashMultimap.<InetAddress, RibUpdate>create());

		pushedPaths = new HashMap<InetAddress, Path>();
		prefixToPath = new HashMap<Prefix, Path>();
//		pushedFlows = HashMultimap.<Prefix, PushedFlowMod>create();
		pushedFlowIds = HashMultimap.<Prefix, FlowId>create();

		flowCache = new FlowCache(floodlightProvider);

		bgpUpdatesExecutor = Executors.newSingleThreadExecutor(
				new ThreadFactoryBuilder().setNameFormat("bgp-updates-%d").build());

		//Read in config values
		bgpdRestIp = context.getConfigParams(this).get("BgpdRestIp");
		if (bgpdRestIp == null){
			log.error("BgpdRestIp property not found in config file");
			System.exit(1);
		}
		else {
			log.info("BgpdRestIp set to {}", bgpdRestIp);
		}

		routerId = context.getConfigParams(this).get("RouterId");
		if (routerId == null){
			log.error("RouterId property not found in config file");
			System.exit(1);
		}
		else {
			log.info("RouterId set to {}", routerId);
		}

		String configFilenameParameter = context.getConfigParams(this).get("configfile");
		if (configFilenameParameter != null){
			configFilename = configFilenameParameter;
		}
		log.debug("Config file set to {}", configFilename);

		readConfiguration(configFilename);
	}

	@Override
	public void startUp(FloodlightModuleContext context) {
		restApi.addRestletRoutable(new BgpRouteWebRoutable());
		topologyService.addListener(this);
		floodlightProvider.addOFSwitchListener(this);

		//Retrieve the RIB from BGPd during startup
		retrieveRib();
	}

	@Override
	public IPatriciaTrie<RibEntry> getPtree() {
		return ptree;
	}

	@Override
	public void clearPtree() {
		ptree = new PatriciaTrie<RibEntry>(32);
	}

	@Override
	public String getBGPdRestIp() {
		return bgpdRestIp;
	}

	@Override
	public String getRouterId() {
		return routerId;
	}

	private void retrieveRib(){
		String url = "http://" + bgpdRestIp + "/wm/bgp/" + routerId;
		String response = RestClient.get(url);

		if (response.equals("")){
			return;
		}

		response = response.replaceAll("\"", "'");
		JSONObject jsonObj = (JSONObject) JSONSerializer.toJSON(response);
		JSONArray rib_json_array = jsonObj.getJSONArray("rib");
		String router_id = jsonObj.getString("router-id");

		int size = rib_json_array.size();

		log.info("Retrived RIB of {} entries from BGPd", size);

		for (int j = 0; j < size; j++) {
			JSONObject second_json_object = rib_json_array.getJSONObject(j);
			String prefix = second_json_object.getString("prefix");
			String nexthop = second_json_object.getString("nexthop");

			//insert each rib entry into the local rib;
			String[] substring = prefix.split("/");
			String prefix1 = substring[0];
			String mask1 = substring[1];

			Prefix p;
			try {
				p = new Prefix(prefix1, Integer.valueOf(mask1));
			} catch (NumberFormatException e) {
				log.warn("Wrong mask format in RIB JSON: {}", mask1);
				continue;
			} catch (IllegalArgumentException e1) {
				log.warn("Wrong prefix format in RIB JSON: {}", prefix1);
				continue;
			}

			RibEntry rib = new RibEntry(router_id, nexthop);

			try {
				ribUpdates.put(new RibUpdate(Operation.UPDATE, p, rib));
			} catch (InterruptedException e) {
				log.debug("Interrupted while pushing onto update queue");
			}
		}
	}

	@Override
	public void newRibUpdate(RibUpdate update) {
		try {
			ribUpdates.put(update);
		} catch (InterruptedException e) {
			log.debug("Interrupted while putting on ribUpdates queue", e);
			Thread.currentThread().interrupt();
		}
	}

	public synchronized void processRibAdd(RibUpdate update) {
		Prefix prefix = update.getPrefix();

		log.debug("Processing prefix add {}", prefix);

		RibEntry rib = ptree.put(prefix, update.getRibEntry());

		if (rib != null && !rib.equals(update.getRibEntry())) {
			//There was an existing nexthop for this prefix. This update supersedes that,
			//so we need to remove the old flows for this prefix from the switches
			_processDeletePrefix(prefix, rib);
		}

		if (update.getRibEntry().getNextHop().equals(
				InetAddresses.forString("0.0.0.0"))) {
			//Route originated by SDN domain
			//We don't handle these at the moment
			log.debug("Own route {} to {}", prefix,
					update.getRibEntry().getNextHop().getHostAddress());
			return;
		}

		_processRibAdd(update);
	}

	private void _processRibAdd(RibUpdate update) {
		Prefix prefix = update.getPrefix();
		RibEntry rib = update.getRibEntry();

		InetAddress dstIpAddress = rib.getNextHop();
		MACAddress nextHopMacAddress;

		// See if we know the MAC address of the next hop
		// TODO if we do not treat the next hop as a device in the future, we need to update this
		IDeviceObject nextHopDevice =
				deviceStorage.getDeviceByIP(InetAddresses.coerceToInteger(dstIpAddress));

		if (nextHopDevice == null){
			log.debug("NextHopDevice for IP: {} is null", dstIpAddress);
			prefixesWaitingOnArp.put(dstIpAddress,
					new RibUpdate(Operation.UPDATE, prefix, rib));
			proxyArp.sendArpRequest(dstIpAddress, this, true);
			return;

		}
		nextHopMacAddress = MACAddress.valueOf(nextHopDevice.getMACAddress());

		// Find the attachment point (egress interface) of the next hop
		Interface egressInterface = null;
		if (bgpPeers.containsKey(dstIpAddress)) {
			//Route to a peer
			log.debug("Route to peer {}", dstIpAddress);
			BgpPeer peer = bgpPeers.get(dstIpAddress);
			egressInterface = interfaces.get(peer.getInterfaceName());
		}
		else {
			//Route to non-peer
			log.debug("Route to non-peer {}", dstIpAddress);
			egressInterface = interfacePtrie.match(
					new Prefix(dstIpAddress.getAddress(), 32));
			if (egressInterface == null) {
				log.warn("No outgoing interface found for {}", dstIpAddress.getHostAddress());
				return;
			}
		}

		if (nextHopMacAddress == null) {
			prefixesWaitingOnArp.put(dstIpAddress,
					new RibUpdate(Operation.UPDATE, prefix, rib));
			proxyArp.sendArpRequest(dstIpAddress, this, true);
			return;
		}
		else {
			if (!bgpPeers.containsKey(dstIpAddress)) {
				//If the prefix is for a non-peer we need to ensure there's a path,
				//and push one if there isn't.
				Path path = pushedPaths.get(dstIpAddress);
				if (path == null) {
					path = new Path(egressInterface, dstIpAddress);
					calculateAndPushPath(path, nextHopMacAddress);
					pushedPaths.put(dstIpAddress, path);
				}

				path.incrementUsers();
				prefixToPath.put(prefix, path);
			}

			//For all prefixes we need to add the first-hop mac-rewriting flows
			addPrefixFlows(prefix, egressInterface, nextHopMacAddress);
		}
	}

	/**
	 * Add a flow to match dst-IP prefix and rewrite MAC for one IP prefix
	 * to all other border switches
	 */
	private void addPrefixFlows(Prefix prefix, Interface egressInterface,
			MACAddress nextHopMacAddress) {
		log.debug("Adding flows for prefix {}, next hop mac {}",
				prefix, nextHopMacAddress);

		FlowPath flowPath = new FlowPath();
		flowPath.setInstallerId(new CallerId("SDNIP"));

		// Set flowPath FlowPathType and FlowPathUserState
		flowPath.setFlowPathType(FlowPathType.FP_TYPE_SHORTEST_PATH);
		flowPath.setFlowPathUserState(FlowPathUserState.FP_USER_ADD);

		// Insert dst-ip prefix based forwarding and MAC rewrite flow entry
		// only to the first-host switches
		FlowPathFlags flowPathFlags = new FlowPathFlags();
		flowPathFlags.setFlags(FlowPathFlags.KEEP_ONLY_FIRST_HOP_ENTRY);
		flowPath.setFlowPathFlags(flowPathFlags);

		// Create the DataPath object: dstSwitchPort
		SwitchPort dstPort = new SwitchPort();
		dstPort.setDpid(new Dpid(egressInterface.getDpid()));
		dstPort.setPort(new Port(egressInterface.getPort()));

		// We only need one flow mod per switch, so pick one interface on each switch
		Map<Long, Interface> srcInterfaces = new HashMap<Long, Interface>();
		for (Interface intf : interfaces.values()) {
			if (!srcInterfaces.containsKey(intf.getDpid())
					&& !intf.equals(egressInterface)) {
				srcInterfaces.put(intf.getDpid(), intf);
			}
		}
		for (Interface srcInterface : srcInterfaces.values()) {

			if (egressInterface.equals(srcInterface)){
				continue;
			}

			// Create flowPath FlowId
			//FlowId returnByRefFlowId = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId);
			flowPath.setFlowId(new FlowId());

			// Create DataPath object: srcSwitchPort
			SwitchPort srcPort = new SwitchPort();
			srcPort.setDpid(new Dpid(srcInterface.getDpid()));
			srcPort.setPort(new Port(srcInterface.getPort()));

			DataPath dataPath = new DataPath();
			dataPath.setSrcPort(srcPort);
			dataPath.setDstPort(dstPort);
			flowPath.setDataPath(dataPath);

			// Create flow path matching condition(s): IPv4 Prefix
			FlowEntryMatch flowEntryMatch = new FlowEntryMatch();
			flowEntryMatch.enableEthernetFrameType(Ethernet.TYPE_IPv4);
			IPv4Net dstIPv4Net= new IPv4Net(prefix.toString());
			flowEntryMatch.enableDstIPv4Net(dstIPv4Net);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			/*
			 * Create the Flow Entry Action(s): dst-MAC rewrite action
			 */
			FlowEntryActions flowEntryActions = new FlowEntryActions();
			FlowEntryAction flowEntryAction1 = new FlowEntryAction();
			flowEntryAction1.setActionSetEthernetDstAddr(nextHopMacAddress);
			// flowEntryAction1.actionSetEthernetDstAddr(nextHopMacAddress);
			flowEntryActions.addAction(flowEntryAction1);
			flowPath.setFlowEntryActions(flowEntryActions);

			// Flow Path installation, only to first hop switches
			if (flowManagerService.addFlow(flowPath) == null) {
				log.error("Failed to install flow path to the first hop for " +
						"prefix: {}, nextHopMacAddress: {}", prefix.getAddress(),
						nextHopMacAddress);
			}
			else {
				log.debug("Successfully installed flow path to the first hop " +
						"for prefix: {}, nextHopMacAddress: {}", prefix.getAddress(),
						nextHopMacAddress);

				pushedFlowIds.put(prefix, flowPath.flowId());
			}
		}
	}

	public synchronized void processRibDelete(RibUpdate update) {
		Prefix prefix = update.getPrefix();

		if (ptree.remove(prefix, update.getRibEntry())) {
			/*
			 * Only delete flows if an entry was actually removed from the trie.
			 * If no entry was removed, the <prefix, nexthop> wasn't there so
			 * it's probably already been removed and we don't need to do anything
			 */
			_processDeletePrefix(prefix, update.getRibEntry());
		}
	}

	private void _processDeletePrefix(Prefix prefix, RibEntry ribEntry) {
		deletePrefixFlows(prefix);

		log.debug("Deleting {} to {}", prefix, ribEntry.getNextHop());

		if (!bgpPeers.containsKey(ribEntry.getNextHop())) {
			log.debug("Getting path for route with non-peer nexthop");
			Path path = prefixToPath.remove(prefix);

			if (path != null) {
				//path could be null if we added to the Ptree but didn't push
				//flows yet because we were waiting to resolve ARP

				path.decrementUsers();
				if (path.getUsers() <= 0 && !path.isPermanent()) {
					deletePath(path);
					pushedPaths.remove(path.getDstIpAddress());
				}
			}
		}
	}

	// TODO have not tested this module
	private void deletePrefixFlows(Prefix prefix) {
		log.debug("Deleting flows for prefix {}", prefix);

		Collection<FlowId> flowIds = pushedFlowIds.removeAll(prefix);
		for (FlowId flowId : flowIds) {
			if (log.isTraceEnabled()) {
				//Trace the flow status by flowPath in the switch before deleting it
				log.trace("Pushing a DELETE flow mod to flowPath : {}",
						flowManagerService.getFlow(flowId).toString());
			}

			if( flowManagerService.deleteFlow(flowId))
			{
				log.debug("Successfully deleted FlowId: {}",flowId);
			}
			else
			{
				log.debug("Failed to delete FlowId: {}",flowId);
			}
		}
	}

	// TODO need to record the path and then delete here
	private void deletePath(Path path) {
		log.debug("Deleting flows for path to {}",
				path.getDstIpAddress().getHostAddress());

		// TODO need update
		/*for (PushedFlowMod pfm : path.getFlowMods()) {
			if (log.isTraceEnabled()) {
				log.trace("Pushing a DELETE flow mod to {}, dst MAC {}",
						new Object[] {HexString.toHexString(pfm.getDpid()),
						HexString.toHexString(pfm.getFlowMod().getMatch().getDataLayerDestination())
				});
			}

			sendDeleteFlowMod(pfm.getFlowMod(), pfm.getDpid());
		}*/
	}


	//TODO test next-hop changes
	//TODO check delete/add synchronization

	/**
	 * On startup, we need to calculate a full mesh of paths between all gateway
	 * switches
	 */
	private void setupFullMesh(){
		//For each border router, calculate and install a path from every other
		//border switch to said border router. However, don't install the entry
		//in to the first hop switch, as we need to install an entry to rewrite
		//for each prefix received. This will be done later when prefixes have
		//actually been received.

		for (BgpPeer peer : bgpPeers.values()) {
			Interface peerInterface = interfaces.get(peer.getInterfaceName());

			//We know there's not already a Path here pushed, because this is
			//called before all other routing
			Path path = new Path(peerInterface, peer.getIpAddress());
			path.setPermanent();

			//See if we know the MAC address of the peer. If not we can't
			//do anything until we learn it
			MACAddress macAddress;
			IDeviceObject nextHopDevice =
					deviceStorage.getDeviceByIP(InetAddresses.coerceToInteger(peer.getIpAddress()));

			if(nextHopDevice == null){
				log.debug("There is no DeviceObject for {}", peer.getIpAddress().getHostAddress());
				//Put in the pending paths list first
				pathsWaitingOnArp.put(peer.getIpAddress(), path);
				proxyArp.sendArpRequest(peer.getIpAddress(), this, true);
				continue;
			}

			macAddress = MACAddress.valueOf(nextHopDevice.getMACAddress());

			if (macAddress == null) {
				log.debug("Don't know MAC for {}", peer.getIpAddress().getHostAddress());
				//Put in the pending paths list first
				pathsWaitingOnArp.put(peer.getIpAddress(), path);
				proxyArp.sendArpRequest(peer.getIpAddress(), this, true);
				continue;
			}

			//If we know the MAC, lets go ahead and push the paths to this peer
			calculateAndPushPath(path, macAddress);
		}
	}

	private void calculateAndPushPath(Path path, MACAddress dstMacAddress) {
		Interface dstInterface = path.getDstInterface();

		log.debug("Setting up path to {}, {}", path.getDstIpAddress().getHostAddress(),
				dstMacAddress);

		FlowPath flowPath = new FlowPath();

		flowPath.setInstallerId(new CallerId("SDNIP"));

		// Set flowPath FlowPathType and FlowPathUserState
		flowPath.setFlowPathType(FlowPathType.FP_TYPE_SHORTEST_PATH);
		flowPath.setFlowPathUserState(FlowPathUserState.FP_USER_ADD);

		// Insert the dest-mac based forwarding flow entry to the non-first-hop switches
		FlowPathFlags flowPathFlags = new FlowPathFlags();
		flowPathFlags.setFlags(FlowPathFlags.DISCARD_FIRST_HOP_ENTRY);
		flowPath.setFlowPathFlags(flowPathFlags);

		// Create the DataPath object: dstSwitchPort
		SwitchPort dstPort = new SwitchPort();
		dstPort.setDpid(new Dpid(dstInterface.getDpid()));
		dstPort.setPort(new Port(dstInterface.getPort()));

		for (Interface srcInterface : interfaces.values()) {

			if (dstInterface.equals(srcInterface)){
				continue;
			}

			// Create flowPath FlowId
			//FlowId returnByRefFlowId = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId);
			flowPath.setFlowId(new FlowId());

			// Create the DataPath object: srcSwitchPort
			SwitchPort srcPort = new SwitchPort();
			srcPort.setDpid(new Dpid(srcInterface.getDpid()));
			srcPort.setPort(new Port(srcInterface.getPort()));

			DataPath dataPath = new DataPath();
			dataPath.setSrcPort(srcPort);
			dataPath.setDstPort(dstPort);
			flowPath.setDataPath(dataPath);

			// Create the Flow Path Match condition(s)
			FlowEntryMatch flowEntryMatch = new FlowEntryMatch();
			flowEntryMatch.enableEthernetFrameType(Ethernet.TYPE_IPv4);
			flowEntryMatch.enableDstMac(dstMacAddress);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			// NOTE: No need to add ACTION_OUTPUT. It is implied when creating
			// Shortest Path Flow, and is always the last action for the Flow Entries
			log.debug("FlowPath of MAC based forwarding: {}", flowPath.toString());
			if (flowManagerService.addFlow(flowPath) == null) {
				log.error("Failed to set up MAC based forwarding path to {}, {}",
						path.getDstIpAddress().getHostAddress(),dstMacAddress);
			}
			else {
				log.debug("Successfully set up MAC based forwarding path to {}, {}",
						path.getDstIpAddress().getHostAddress(),dstMacAddress);
			}
		}
	}

	/**
	 *  Pre-actively install all BGP traffic paths from BGP host attachment point
	 *  in SDN network to all the virtual gateways to BGP peers in other networks
	 */
	private void setupBgpPaths(){

		for (BgpPeer bgpPeer : bgpPeers.values()){

			FlowPath flowPath = new FlowPath();
			flowPath.setInstallerId(new CallerId("SDNIP"));

			// Set flowPath FlowPathType and FlowPathUserState
			flowPath.setFlowPathType(FlowPathType.FP_TYPE_SHORTEST_PATH);
			flowPath.setFlowPathUserState(FlowPathUserState.FP_USER_ADD);

			// Install flow paths between BGPd and its peers
			// There is no need to set the FlowPathFlags
			flowPath.setFlowPathFlags(new FlowPathFlags(0));

			Interface peerInterface = interfaces.get(bgpPeer.getInterfaceName());

			// set flowPath FlowId
			//FlowId returnByRefFlowId = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId);


			// Create the Flow Path Match condition(s)
			FlowEntryMatch flowEntryMatch = new FlowEntryMatch();
			flowEntryMatch.enableEthernetFrameType(Ethernet.TYPE_IPv4);

			// Match both source address and dest address
			IPv4Net dstIPv4Net= new IPv4Net(bgpPeer.getIpAddress().getHostAddress()+"/32");
			flowEntryMatch.enableDstIPv4Net(dstIPv4Net);

			IPv4Net srcIPv4Net= new IPv4Net(peerInterface.getIpAddress().getHostAddress()+"/32");
			flowEntryMatch.enableSrcIPv4Net(srcIPv4Net);

			// Match TCP protocol
			flowEntryMatch.enableIpProto(IPv4.PROTOCOL_TCP);

			// Match destination TCP port
			flowEntryMatch.enableDstTcpUdpPort(BGP_PORT);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			/**
			 * Create the DataPath: BGP -> BGP peer
			 */
			// Flow path for src-TCP-port
			DataPath dataPath = new DataPath();

			SwitchPort srcPort = new SwitchPort();
			srcPort.setDpid(bgpdAttachmentPoint.dpid());
			srcPort.setPort(bgpdAttachmentPoint.port());
			dataPath.setSrcPort(srcPort);

			SwitchPort dstPort = new SwitchPort();
			dstPort.setDpid(new Dpid(peerInterface.getDpid()));
			dstPort.setPort(new Port(peerInterface.getSwitchPort().port()));
			dataPath.setDstPort(dstPort);

			flowPath.setDataPath(dataPath);

			if (flowManagerService.addFlow(flowPath) == null) {
				log.error("Failed to set up path BGP -> peer {}"+"; dst-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully set up path BGP -> peer {}"+"; dst-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}

			// Disable dst-TCP-port, and set src-TCP-port
			flowEntryMatch.disableDstTcpUdpPort();
			flowEntryMatch.enableSrcTcpUdpPort(BGP_PORT);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			// Create a new FlowId
			//FlowId returnByRefFlowId2 = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId2);
			flowPath.setFlowId(new FlowId());

			if (flowManagerService.addFlow(flowPath) == null) {
				log.error("Failed to set up path BGP -> Peer {}" + "; src-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully set up path BGP -> Peer {}" + "; src-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}

			/**
			 * Create the DataPath: BGP <-BGP peer
			 */
			// Reversed BGP flow path for src-TCP-port
			//FlowId returnByRefFlowId3 = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId3);
			flowPath.setFlowId(new FlowId());

			DataPath reverse_dataPath = new DataPath();

			SwitchPort reverse_dstPort = new SwitchPort();
			reverse_dstPort.setDpid(bgpdAttachmentPoint.dpid());
			reverse_dstPort.setPort(bgpdAttachmentPoint.port());
			reverse_dataPath.setDstPort(reverse_dstPort);

			SwitchPort reverse_srcPort = new SwitchPort();
			reverse_srcPort.setDpid(new Dpid(peerInterface.getDpid()));
			reverse_srcPort.setPort(new Port(peerInterface.getSwitchPort().port()));
			reverse_dataPath.setSrcPort(reverse_srcPort);
			flowPath.setDataPath(reverse_dataPath);

			// reverse the dst IP and src IP addresses
			flowEntryMatch.enableDstIPv4Net(srcIPv4Net);
			flowEntryMatch.enableSrcIPv4Net(dstIPv4Net);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			log.debug("Reversed BGP FlowPath: {}", flowPath.toString());

			if (flowManagerService.addFlow(flowPath) == null) {

				log.error("Failed to set up path BGP <- Peer {}" + "; src-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully set up path BGP <- Peer {}" + "; src-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}

			// Reversed BGP flow path for dst-TCP-port
			//FlowId returnByRefFlowId4 = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId4);
			flowPath.setFlowId(new FlowId());

			// Disable src-TCP-port, and set the dst-TCP-port
			flowEntryMatch.disableSrcTcpUdpPort();
			flowEntryMatch.enableDstTcpUdpPort(BGP_PORT);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			log.debug("Reversed BGP FlowPath: {}", flowPath.toString());

			if (flowManagerService.addFlow(flowPath) == null) {
				log.error("Failed to setting up path BGP <- Peer {}" + "; dst-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully setting up path BGP <- Peer {}" + "; dst-TCP-port:179",
						bgpPeer.getIpAddress().getHostAddress());
			}

			/**
			 * ICMP paths between BGPd and its peers
			 */
			//match ICMP protocol BGP <- Peer
			//FlowId returnByRefFlowId5 = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId5);
			flowPath.setFlowId(new FlowId());

			flowEntryMatch.enableIpProto(IPv4.PROTOCOL_ICMP);
			flowEntryMatch.disableSrcTcpUdpPort();
			flowEntryMatch.disableDstTcpUdpPort();

			flowPath.setFlowEntryMatch(flowEntryMatch);

			flowPath.setDataPath(reverse_dataPath);

			log.debug("Reversed ICMP FlowPath: {}", flowPath.toString());

			if (flowManagerService.addFlow(flowPath) == null) {

				log.error("Failed to set up ICMP path BGP <- Peer {}",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully set up ICMP path BGP <- Peer {}",
						bgpPeer.getIpAddress().getHostAddress());
			}

			//match ICMP protocol BGP -> Peer
			//FlowId returnByRefFlowId6 = new FlowId(flowManagerService.getNextFlowEntryId());
			//flowPath.setFlowId(returnByRefFlowId6);
			flowPath.setFlowId(new FlowId());

			flowEntryMatch.enableDstIPv4Net(dstIPv4Net);
			flowEntryMatch.enableSrcIPv4Net(srcIPv4Net);
			flowPath.setFlowEntryMatch(flowEntryMatch);

			flowPath.setDataPath(dataPath);

			log.debug("ICMP flowPath: {}", flowPath.toString());


			if (flowManagerService.addFlow(flowPath) == null) {

				log.error("Failed to set up ICMP path BGP -> Peer {}",
						bgpPeer.getIpAddress().getHostAddress());
			}
			else {
				log.debug("Successfully set up ICMP path BGP -> Peer {}",
						bgpPeer.getIpAddress().getHostAddress());
			}
		}
	}

	@Override
	public void arpResponse(InetAddress ipAddress, MACAddress macAddress) {
		log.debug("Received ARP response: {} => {}",
				ipAddress.getHostAddress(), macAddress);

		/*
		 * We synchronize on this to prevent changes to the ptree while we're pushing
		 * flows to the switches. If the ptree changes, the ptree and switches
		 * could get out of sync.
		 */
		synchronized (this) {
			Path path = pathsWaitingOnArp.remove(ipAddress);

			if (path != null) {
				log.debug("Pushing path to {} at {} on {}", new Object[] {
						path.getDstIpAddress().getHostAddress(), macAddress,
						path.getDstInterface().getSwitchPort()});
				//These paths should always be to BGP peers. Paths to non-peers are
				//handled once the first prefix is ready to push
				if (pushedPaths.containsKey(path.getDstIpAddress())) {
					//A path already got pushed to this endpoint while we were waiting
					//for ARP. We'll copy over the permanent attribute if it is set on this path.
					if (path.isPermanent()) {
						pushedPaths.get(path.getDstIpAddress()).setPermanent();
					}
				}
				else {
					calculateAndPushPath(path, macAddress);
					pushedPaths.put(path.getDstIpAddress(), path);
				}
			}

			Set<RibUpdate> prefixesToPush = prefixesWaitingOnArp.removeAll(ipAddress);

			for (RibUpdate update : prefixesToPush) {
				//These will always be adds

				RibEntry rib = ptree.lookup(update.getPrefix());
				if (rib != null && rib.equals(update.getRibEntry())) {
					log.debug("Pushing prefix {} next hop {}", update.getPrefix(),
							rib.getNextHop().getHostAddress());
					//We only push prefix flows if the prefix is still in the ptree
					//and the next hop is the same as our update. The prefix could
					//have been removed while we were waiting for the ARP, or the
					//next hop could have changed.
					_processRibAdd(update);
				} else {
					log.debug("Received ARP response, but {},{} is no longer in ptree",
							update.getPrefix(), update.getRibEntry());
				}
			}
		}
	}

	//TODO wait the priority module of the flow Manager
	private void setupArpFlows() {
		OFMatch match = new OFMatch();
		match.setDataLayerType(Ethernet.TYPE_ARP);
		match.setWildcards(match.getWildcards() & ~OFMatch.OFPFW_DL_TYPE);

		OFFlowMod fm = new OFFlowMod();
		fm.setMatch(match);

		OFActionOutput action = new OFActionOutput();
		action.setPort(OFPort.OFPP_CONTROLLER.getValue());
		action.setMaxLength((short)0xffff);
		List<OFAction> actions = new ArrayList<OFAction>(1);
		actions.add(action);
		fm.setActions(actions);

		fm.setIdleTimeout((short)0)
		.setHardTimeout((short)0)
		.setBufferId(OFPacketOut.BUFFER_ID_NONE)
		.setCookie(0)
		.setCommand(OFFlowMod.OFPFC_ADD)
		.setPriority(ARP_PRIORITY)
		.setLengthU(OFFlowMod.MINIMUM_LENGTH + OFActionOutput.MINIMUM_LENGTH);

		for (String strdpid : switches){
			flowCache.write(HexString.toLong(strdpid), fm);
		}
	}
	//TODO need update, waiting for the priority feature from flow Manager
	private void setupDefaultDropFlows() {
		OFFlowMod fm = new OFFlowMod();
		fm.setMatch(new OFMatch());
		fm.setActions(new ArrayList<OFAction>()); //No action means drop

		fm.setIdleTimeout((short)0)
		.setHardTimeout((short)0)
		.setBufferId(OFPacketOut.BUFFER_ID_NONE)
		.setCookie(0)
		.setCommand(OFFlowMod.OFPFC_ADD)
		.setPriority((short)0)
		.setLengthU(OFFlowMod.MINIMUM_LENGTH);

		OFFlowMod fmLLDP;
		OFFlowMod fmBDDP;
		try {
			fmLLDP = fm.clone();
			fmBDDP = fm.clone();
		} catch (CloneNotSupportedException e1) {
			log.error("Error cloning flow mod", e1);
			return;
		}

		OFMatch matchLLDP = new OFMatch();
		matchLLDP.setDataLayerType((short)0x88cc);
		matchLLDP.setWildcards(matchLLDP.getWildcards() & ~ OFMatch.OFPFW_DL_TYPE);
		fmLLDP.setMatch(matchLLDP);

		OFMatch matchBDDP = new OFMatch();
		matchBDDP.setDataLayerType((short)0x8942);
		matchBDDP.setWildcards(matchBDDP.getWildcards() & ~ OFMatch.OFPFW_DL_TYPE);
		fmBDDP.setMatch(matchBDDP);

		OFActionOutput action = new OFActionOutput();
		action.setPort(OFPort.OFPP_CONTROLLER.getValue());
		action.setMaxLength((short)0xffff);
		List<OFAction> actions = new ArrayList<OFAction>(1);
		actions.add(action);

		fmLLDP.setActions(actions);
		fmBDDP.setActions(actions);

		fmLLDP.setPriority(ARP_PRIORITY);
		fmLLDP.setLengthU(OFFlowMod.MINIMUM_LENGTH + OFActionOutput.MINIMUM_LENGTH);
		fmBDDP.setPriority(ARP_PRIORITY);
		fmBDDP.setLengthU(OFFlowMod.MINIMUM_LENGTH + OFActionOutput.MINIMUM_LENGTH);

		List<OFFlowMod> flowModList = new ArrayList<OFFlowMod>(3);
		flowModList.add(fm);
		flowModList.add(fmLLDP);
		flowModList.add(fmBDDP);

		for (String strdpid : switches){
			flowCache.write(HexString.toLong(strdpid), flowModList);
		}
	}

	private void beginRouting(){
		log.debug("Topology is now ready, beginning routing function");
		topology = topologyNetService.newDatabaseTopology();

		// Wait Pavlin's API. We need the following functions.
		/*setupArpFlows();
		setupDefaultDropFlows();*/

		setupBgpPaths();
		setupFullMesh();

		//Suppress link discovery on external-facing router ports
		for (Interface intf : interfaces.values()) {
			linkDiscoveryService.AddToSuppressLLDPs(intf.getDpid(), intf.getPort());
		}

		bgpUpdatesExecutor.execute(new Runnable() {
			@Override
			public void run() {
				doUpdatesThread();
			}
		});
	}

	// Before inserting the paths for BGP traffic, we should check
	// whether all the switches in the configure file are discovered by onos.
	private void checkSwitchesConnected(){
		for (String dpid : switches){
			Iterator<ISwitchObject> activeSwitches = topoSwitchService.
					getActiveSwitches().iterator();
			while(activeSwitches.hasNext())
			{
				ISwitchObject switchObject = activeSwitches.next();
				if (switchObject.getDPID().equals(dpid)) {
					break;
				}
				if(activeSwitches.hasNext() == false) {
					log.debug("Not all switches are here yet");
					return;
				}
			}
		}
		switchesConnected = true;
	}

	//Actually we only need to go half way round to verify full mesh connectivity
	//(n^2)/2
	private void checkTopologyReady(){
		for (Interface dstInterface : interfaces.values()) {
			for (Interface srcInterface : interfaces.values()) {
				if (dstInterface.equals(srcInterface)) {
					continue;
				}

				DataPath shortestPath = topologyNetService.getDatabaseShortestPath(
						srcInterface.getSwitchPort(), dstInterface.getSwitchPort());

				if (shortestPath == null){
					log.debug("Shortest path between {} and {} not found",
							srcInterface.getSwitchPort(), dstInterface.getSwitchPort());
					return;
				}
			}
		}
		topologyReady = true;
	}

	private void checkStatus(){
		if (!switchesConnected){
			checkSwitchesConnected();
		}
		boolean oldTopologyReadyStatus = topologyReady;
		if (switchesConnected && !topologyReady){
			checkTopologyReady();
		}
		if (!oldTopologyReadyStatus && topologyReady){
			beginRouting();
		}
	}

	private void doUpdatesThread() {
		boolean interrupted = false;
		try {
			while (true) {
				try {
					RibUpdate update = ribUpdates.take();
					switch (update.getOperation()){
					case UPDATE:
						if (validateUpdate(update)) {
							processRibAdd(update);
						}
						else {
							log.debug("Rib UPDATE out of order: {} via {}",
									update.getPrefix(), update.getRibEntry().getNextHop());
						}
						break;
					case DELETE:
						if (validateUpdate(update)) {
							processRibDelete(update);
						}
						else {
							log.debug("Rib DELETE out of order: {} via {}",
									update.getPrefix(), update.getRibEntry().getNextHop());
						}
						break;
					}
				} catch (InterruptedException e) {
					log.debug("Interrupted while taking from updates queue", e);
					interrupted = true;
				} catch (Exception e) {
					log.debug("exception", e);
				}
			}
		} finally {
			if (interrupted) {
				Thread.currentThread().interrupt();
			}
		}
	}

	private boolean validateUpdate(RibUpdate update) {
		RibEntry newEntry = update.getRibEntry();
		RibEntry oldEntry = ptree.lookup(update.getPrefix());

		//If there is no existing entry we must assume this is the most recent
		//update. However this might not always be the case as we might have a
		//POST then DELETE reordering.
		//if (oldEntry == null || !newEntry.getNextHop().equals(oldEntry.getNextHop())) {
		if (oldEntry == null) {
			return true;
		}

		// This handles the case where routes are gathered in the initial
		// request because they don't have sequence number info
		if (newEntry.getSysUpTime() == -1 && newEntry.getSequenceNum() == -1) {
			return true;
		}

		if (newEntry.getSysUpTime() > oldEntry.getSysUpTime()) {
			return true;
		}
		else if (newEntry.getSysUpTime() == oldEntry.getSysUpTime()) {
			if (newEntry.getSequenceNum() > oldEntry.getSequenceNum()) {
				return true;
			}
			else {
				return false;
			}
		}
		else {
			return false;
		}
	}

	@Override
	public void topologyChanged() {
		if (topologyReady) {
			return;
		}

		boolean refreshNeeded = false;
		for (LDUpdate ldu : topologyService.getLastLinkUpdates()){
			if (!ldu.getOperation().equals(ILinkDiscovery.UpdateOperation.LINK_UPDATED)){
				//We don't need to recalculate anything for just link updates
				//They happen very frequently
				refreshNeeded = true;
			}

			log.debug("Topo change {}", ldu.getOperation());

			if (ldu.getOperation().equals(ILinkDiscovery.UpdateOperation.LINK_ADDED)){
				synchronized (linkUpdates) {
					linkUpdates.add(ldu);
				}
			}
		}

		if (refreshNeeded && !topologyReady){
			topologyChangeDetectorTask.reschedule(TOPO_DETECTION_WAIT, TimeUnit.SECONDS);
		}
	}

	@Override
	public void addedSwitch(IOFSwitch sw) {
		if (!topologyReady) {
			sw.clearAllFlowMods();
		}

		flowCache.switchConnected(sw);
	}

	@Override
	public void removedSwitch(IOFSwitch sw) {}

	@Override
	public void switchPortChanged(Long switchId) {}

	@Override
	public String getName() {
		return "BgpRoute";
	}

	/*
	 * IConfigInfoService methods
	 */

	@Override
	public boolean isInterfaceAddress(InetAddress address) {
		Interface intf = interfacePtrie.match(new Prefix(address.getAddress(), 32));
		return (intf != null && intf.getIpAddress().equals(address));
	}

	@Override
	public boolean inConnectedNetwork(InetAddress address) {
		Interface intf = interfacePtrie.match(new Prefix(address.getAddress(), 32));
		return (intf != null && !intf.getIpAddress().equals(address));
	}

	@Override
	public boolean fromExternalNetwork(long inDpid, short inPort) {
		for (Interface intf : interfaces.values()) {
			if (intf.getDpid() == inDpid && intf.getPort() == inPort) {
				return true;
			}
		}
		return false;
	}

	@Override
	public Interface getOutgoingInterface(InetAddress dstIpAddress) {
		return interfacePtrie.match(new Prefix(dstIpAddress.getAddress(), 32));
	}

	@Override
	public boolean hasLayer3Configuration() {
		return !interfaces.isEmpty();
	}

	@Override
	public MACAddress getRouterMacAddress() {
		return bgpdMacAddress;
	}

	@Override
	public short getVlan() {
		return vlan;
	}
}