apps/routeradvertisement/src/main/java/org/onosproject/ra/RouterAdvertisementManager.java - onos - Gitiles

 /*
  * Copyright 2017-present Open Networking Foundation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.onosproject.ra;

 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Property;
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onlab.packet.EthType;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.ICMP6;
 import org.onlab.packet.IPv6;
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.Ip6Address;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.ndp.RouterAdvertisement;
 import org.onlab.packet.ndp.NeighborDiscoveryOptions;
 import org.onosproject.cfg.ComponentConfigService;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.mastership.MastershipService;
 import org.onosproject.net.MastershipRole;
 import org.onosproject.net.intf.Interface;
 import org.onosproject.net.intf.InterfaceEvent;
 import org.onosproject.net.intf.InterfaceListener;
 import org.onosproject.net.intf.InterfaceService;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.host.InterfaceIpAddress;
 import org.onosproject.net.packet.DefaultOutboundPacket;
 import org.onosproject.net.packet.OutboundPacket;
 import org.onosproject.net.packet.PacketService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.osgi.service.component.ComponentContext;

 import javax.annotation.concurrent.GuardedBy;
 import java.nio.ByteBuffer;
 import java.util.Dictionary;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Arrays;
 import java.util.Optional;

 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;

 import static com.google.common.base.Strings.isNullOrEmpty;
 import static org.onlab.util.Tools.get;
 import static org.onlab.util.Tools.groupedThreads;

 /**
  * Manages IPv6 Router Advertisements.
  */
 @Component(immediate = true)
 public class RouterAdvertisementManager {

     private final Logger log = LoggerFactory.getLogger(getClass());
     private static final String PROP_RA_THREADS_POOL = "raPoolSize";
     private static final int DEFAULT_RA_THREADS_POOL_SIZE = 10;
     private static final String PROP_RA_THREADS_DELAY = "raThreadDelay";
     private static final int DEFAULT_RA_THREADS_DELAY = 5;

     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected CoreService coreService;

     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     PacketService packetService;

     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected ComponentConfigService componentConfigService;

     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     public InterfaceService interfaceService;

     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     public MastershipService mastershipService;

     @Property(name = PROP_RA_THREADS_POOL, intValue = DEFAULT_RA_THREADS_POOL_SIZE,
             label = "Router Advertisement thread pool capacity")
     protected int raPoolSize = DEFAULT_RA_THREADS_POOL_SIZE;

     @Property(name = PROP_RA_THREADS_DELAY, intValue = DEFAULT_RA_THREADS_DELAY,
             label = "Router Advertisement thread delay in seconds")
     protected int raThreadDelay = DEFAULT_RA_THREADS_DELAY;

     private ScheduledExecutorService executors = null;

     @GuardedBy(value = "this")
     private final Map<ConnectPoint, ScheduledFuture<?>> transmitters = new LinkedHashMap<>();

     private static final String APP_NAME = "org.onosproject.routeradvertisement";
     private ApplicationId appId;

     // Listener for handling dynamic interface modifications.
     private class InternalInterfaceListener implements InterfaceListener {
         @Override
         public void event(InterfaceEvent event) {
             Interface i = event.subject();
             switch (event.type()) {
                 case INTERFACE_ADDED:
                     if (mastershipService.getLocalRole(i.connectPoint().deviceId())
                             == MastershipRole.MASTER) {
                         activateRouterAdvertisement(i.connectPoint(),
                                 i.ipAddressesList());
                     }
                     break;
                 case INTERFACE_REMOVED:
                     if (mastershipService.getLocalRole(i.connectPoint().deviceId())
                             == MastershipRole.MASTER) {
                         deactivateRouterAdvertisement(i.connectPoint(),
                                 i.ipAddressesList());
                     }
                     break;
                 case INTERFACE_UPDATED:
                     break;
                 default:
                     break;
             }
         }
     }
     private final InterfaceListener interfaceListener = new InternalInterfaceListener();

     // Enables RA threads on 'connectPoint' with configured IPv6s
     private void activateRouterAdvertisement(ConnectPoint connectPoint, List<InterfaceIpAddress> addresses) {
         synchronized (this) {
             RAWorkerThread worker = new RAWorkerThread(connectPoint, addresses, raThreadDelay);
             ScheduledFuture<?> handler = executors.scheduleAtFixedRate(worker, raThreadDelay,
                     raThreadDelay, TimeUnit.SECONDS);
             transmitters.put(connectPoint, handler);
         }

     }

     // Disables already activated RA threads on 'connectPoint'
     private void deactivateRouterAdvertisement(ConnectPoint connectPoint, List<InterfaceIpAddress> addresses) {
         synchronized (this) {
             if (connectPoint != null) {
                 ScheduledFuture<?> handler = transmitters.get(connectPoint);
                 handler.cancel(false);
                 transmitters.remove(connectPoint);
             }
         }
     }

     @Activate
     protected void activate(ComponentContext context) {
         // Basic application registrations.
         appId = coreService.registerApplication(APP_NAME);
         componentConfigService.registerProperties(getClass());

         // Loading configured properties.
         if (context != null) {
             Dictionary<?, ?> properties = context.getProperties();
             try {
                 String s = get(properties, PROP_RA_THREADS_POOL);
                 raPoolSize = isNullOrEmpty(s) ?
                         DEFAULT_RA_THREADS_POOL_SIZE : Integer.parseInt(s.trim());

                 s = get(properties, PROP_RA_THREADS_DELAY);
                 raThreadDelay = isNullOrEmpty(s) ?
                         DEFAULT_RA_THREADS_DELAY : Integer.parseInt(s.trim());

             } catch (NumberFormatException e) {
                 log.warn("Component configuration had invalid value, loading default values.", e);
             }
         }

         // Interface listener for dynamic RA handling.
         interfaceService.addListener(interfaceListener);

         // Initialize RA thread pool
         executors = Executors.newScheduledThreadPool(raPoolSize,
                 groupedThreads("RouterAdvertisement", "event-%d", log));

         // Start Router Advertisement Transmission for all configured interfaces.
         interfaceService.getInterfaces()
                 .stream()
                 .filter(i -> mastershipService.getLocalRole(i.connectPoint().deviceId())
                         == MastershipRole.MASTER)
                 .filter(i -> i.ipAddressesList()
                         .stream()
                         .anyMatch(ia -> ia.ipAddress().version().equals(IpAddress.Version.INET6)))
                 .forEach(j ->
                         activateRouterAdvertisement(j.connectPoint(), j.ipAddressesList())
                 );
     }

     @Deactivate
     protected void deactivate() {
         // Unregister resources.
         componentConfigService.unregisterProperties(getClass(), false);
         interfaceService.removeListener(interfaceListener);

         // Clear out Router Advertisement Transmission for all configured interfaces.
         interfaceService.getInterfaces()
                 .stream()
                 .filter(i -> mastershipService.getLocalRole(i.connectPoint().deviceId())
                         == MastershipRole.MASTER)
                 .filter(i -> i.ipAddressesList()
                         .stream()
                         .anyMatch(ia -> ia.ipAddress().version().equals(IpAddress.Version.INET6)))
                 .forEach(j ->
                         deactivateRouterAdvertisement(j.connectPoint(), j.ipAddressesList())
                 );
     }

     // Worker thread for actually sending ICMPv6 RA packets.
     private class RAWorkerThread implements Runnable {

         ConnectPoint connectPoint;
         List<InterfaceIpAddress> ipAddresses;
         int retransmitPeriod;

         // Various fixed values in RA packet
         public static final byte RA_HOP_LIMIT = (byte) 0xff;
         public static final short RA_ROUTER_LIFETIME = (short) 1800;
         public static final int RA_OPTIONS_BUFFER_SIZE = 500;
         public static final int RA_OPTION_MTU_VALUE = 1500;
         public static final int RA_OPTION_PREFIX_VALID_LIFETIME = 600;
         public static final int RA_OPTION_PREFIX_PREFERRED_LIFETIME = 600;
         public static final int RA_RETRANSMIT_CALIBRATION_PERIOD = 1;


         RAWorkerThread(ConnectPoint connectPoint, List<InterfaceIpAddress> ipAddresses, int period) {
             this.connectPoint = connectPoint;
             this.ipAddresses = ipAddresses;
             retransmitPeriod = period;
         }

         public void run() {
             // Router Advertisement header filling. Please refer RFC-2461.
             RouterAdvertisement ra = new RouterAdvertisement();
             ra.setCurrentHopLimit(RA_HOP_LIMIT);
             ra.setMFlag((byte) 0x01);
             ra.setOFlag((byte) 0x00);
             ra.setRouterLifetime(RA_ROUTER_LIFETIME);
             ra.setReachableTime(0);
             ra.setRetransmitTimer(retransmitPeriod + RA_RETRANSMIT_CALIBRATION_PERIOD);

             // Option : Source link-layer address.
             byte[] optionBuffer = new byte[RA_OPTIONS_BUFFER_SIZE];
             ByteBuffer option = ByteBuffer.wrap(optionBuffer);
             Optional<MacAddress> macAddress = interfaceService.getInterfacesByPort(connectPoint).stream()
                     .map(Interface::mac).findFirst();
             if (!macAddress.isPresent()) {
                 log.warn("Unable to retrieve interface {} MAC address. Terminating RA transmission.", connectPoint);
                 return;
             }
             option.put(macAddress.get().toBytes());
             ra.addOption(NeighborDiscoveryOptions.TYPE_SOURCE_LL_ADDRESS,
                     Arrays.copyOfRange(option.array(), 0, option.position()));

             // Option : MTU.
             option.rewind();
             option.putShort((short) 0);
             option.putInt(RA_OPTION_MTU_VALUE);
             ra.addOption(NeighborDiscoveryOptions.TYPE_MTU,
                     Arrays.copyOfRange(option.array(), 0, option.position()));

             // Option : Prefix information.
             ipAddresses.stream()
                     .filter(i -> i.ipAddress().version().equals(IpAddress.Version.INET6))
                     .forEach(i -> {
                         option.rewind();
                         option.put((byte) i.subnetAddress().prefixLength());
                         // Enable "onlink" option only.
                         option.put((byte) 0x80);
                         option.putInt(RA_OPTION_PREFIX_VALID_LIFETIME);
                         option.putInt(RA_OPTION_PREFIX_PREFERRED_LIFETIME);
                         // Clear reserved fields
                         option.putInt(0x00000000);
                         option.put(IpAddress.makeMaskedAddress(i.ipAddress(),
                                 i.subnetAddress().prefixLength()).toOctets());
                         ra.addOption(NeighborDiscoveryOptions.TYPE_PREFIX_INFORMATION,
                                 Arrays.copyOfRange(option.array(), 0, option.position()));

                     });

             // ICMPv6 header filling.
             ICMP6 icmpv6 = new ICMP6();
             icmpv6.setIcmpType(ICMP6.ROUTER_ADVERTISEMENT);
             icmpv6.setIcmpCode((byte) 0);
             icmpv6.setPayload(ra);

             // IPv6 header filling.
             byte[] ip6AllNodesAddress = Ip6Address.valueOf("ff02::1").toOctets();
             IPv6 ipv6 = new IPv6();
             ipv6.setDestinationAddress(ip6AllNodesAddress);
             /* RA packet L2 source address created from port MAC address.
              * Note : As per RFC-4861 RAs should be sent from link-local address.
              */
             ipv6.setSourceAddress(IPv6.getLinkLocalAddress(macAddress.get().toBytes()));
             ipv6.setNextHeader(IPv6.PROTOCOL_ICMP6);
             ipv6.setHopLimit(RA_HOP_LIMIT);
             ipv6.setTrafficClass((byte) 0xe0);
             ipv6.setPayload(icmpv6);

             // Ethernet header filling.
             Ethernet ethernet = new Ethernet();

             /* Ethernet IPv6 multicast address creation.
              * Refer : RFC 2624 section 7.
              */
             byte[] l2Ipv6MulticastAddress = MacAddress.IPV6_MULTICAST.toBytes();
             IntStream.range(1, 4).forEach(i -> l2Ipv6MulticastAddress[l2Ipv6MulticastAddress.length - i] =
                     ip6AllNodesAddress[ip6AllNodesAddress.length - i]);

             ethernet.setDestinationMACAddress(MacAddress.valueOf(l2Ipv6MulticastAddress));
             ethernet.setSourceMACAddress(macAddress.get().toBytes());
             ethernet.setEtherType(EthType.EtherType.IPV6.ethType().toShort());
             ethernet.setVlanID(Ethernet.VLAN_UNTAGGED);
             ethernet.setPayload(ipv6);
             ethernet.setPad(false);

             // Flush out PACKET_OUT.
             ByteBuffer stream = ByteBuffer.wrap(ethernet.serialize());
             TrafficTreatment treatment = DefaultTrafficTreatment.builder().setOutput(connectPoint.port()).build();
             OutboundPacket packet = new DefaultOutboundPacket(connectPoint.deviceId(),
                     treatment, stream);
             packetService.emit(packet);
         }
     }
 }
	/*
	* Copyright 2017-present Open Networking Foundation
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.onosproject.ra;

	import org.apache.felix.scr.annotations.Activate;
	import org.apache.felix.scr.annotations.Component;
	import org.apache.felix.scr.annotations.Deactivate;
	import org.apache.felix.scr.annotations.Property;
	import org.apache.felix.scr.annotations.Reference;
	import org.apache.felix.scr.annotations.ReferenceCardinality;
	import org.onlab.packet.EthType;
	import org.onlab.packet.Ethernet;
	import org.onlab.packet.ICMP6;
	import org.onlab.packet.IPv6;
	import org.onlab.packet.IpAddress;
	import org.onlab.packet.Ip6Address;
	import org.onlab.packet.MacAddress;
	import org.onlab.packet.ndp.RouterAdvertisement;
	import org.onlab.packet.ndp.NeighborDiscoveryOptions;
	import org.onosproject.cfg.ComponentConfigService;
	import org.onosproject.core.ApplicationId;
	import org.onosproject.core.CoreService;
	import org.onosproject.mastership.MastershipService;
	import org.onosproject.net.MastershipRole;
	import org.onosproject.net.intf.Interface;
	import org.onosproject.net.intf.InterfaceEvent;
	import org.onosproject.net.intf.InterfaceListener;
	import org.onosproject.net.intf.InterfaceService;
	import org.onosproject.net.ConnectPoint;
	import org.onosproject.net.flow.DefaultTrafficTreatment;
	import org.onosproject.net.flow.TrafficTreatment;
	import org.onosproject.net.host.InterfaceIpAddress;
	import org.onosproject.net.packet.DefaultOutboundPacket;
	import org.onosproject.net.packet.OutboundPacket;
	import org.onosproject.net.packet.PacketService;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;
	import org.osgi.service.component.ComponentContext;

	import javax.annotation.concurrent.GuardedBy;
	import java.nio.ByteBuffer;
	import java.util.Dictionary;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Arrays;
	import java.util.Optional;

	import java.util.concurrent.ScheduledExecutorService;
	import java.util.concurrent.ScheduledFuture;
	import java.util.concurrent.Executors;
	import java.util.concurrent.TimeUnit;
	import java.util.stream.IntStream;

	import static com.google.common.base.Strings.isNullOrEmpty;
	import static org.onlab.util.Tools.get;
	import static org.onlab.util.Tools.groupedThreads;

	/**
	* Manages IPv6 Router Advertisements.
	*/
	@Component(immediate = true)
	public class RouterAdvertisementManager {

	private final Logger log = LoggerFactory.getLogger(getClass());
	private static final String PROP_RA_THREADS_POOL = "raPoolSize";
	private static final int DEFAULT_RA_THREADS_POOL_SIZE = 10;
	private static final String PROP_RA_THREADS_DELAY = "raThreadDelay";
	private static final int DEFAULT_RA_THREADS_DELAY = 5;

	@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
	protected CoreService coreService;

	@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
	PacketService packetService;

	@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
	protected ComponentConfigService componentConfigService;

	@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
	public InterfaceService interfaceService;

	@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
	public MastershipService mastershipService;

	@Property(name = PROP_RA_THREADS_POOL, intValue = DEFAULT_RA_THREADS_POOL_SIZE,
	label = "Router Advertisement thread pool capacity")
	protected int raPoolSize = DEFAULT_RA_THREADS_POOL_SIZE;

	@Property(name = PROP_RA_THREADS_DELAY, intValue = DEFAULT_RA_THREADS_DELAY,
	label = "Router Advertisement thread delay in seconds")
	protected int raThreadDelay = DEFAULT_RA_THREADS_DELAY;

	private ScheduledExecutorService executors = null;

	@GuardedBy(value = "this")
	private final Map<ConnectPoint, ScheduledFuture<?>> transmitters = new LinkedHashMap<>();

	private static final String APP_NAME = "org.onosproject.routeradvertisement";
	private ApplicationId appId;

	// Listener for handling dynamic interface modifications.
	private class InternalInterfaceListener implements InterfaceListener {
	@Override
	public void event(InterfaceEvent event) {
	Interface i = event.subject();
	switch (event.type()) {
	case INTERFACE_ADDED:
	if (mastershipService.getLocalRole(i.connectPoint().deviceId())
	== MastershipRole.MASTER) {
	activateRouterAdvertisement(i.connectPoint(),
	i.ipAddressesList());
	}
	break;
	case INTERFACE_REMOVED:
	if (mastershipService.getLocalRole(i.connectPoint().deviceId())
	== MastershipRole.MASTER) {
	deactivateRouterAdvertisement(i.connectPoint(),
	i.ipAddressesList());
	}
	break;
	case INTERFACE_UPDATED:
	break;
	default:
	break;
	}
	}
	}
	private final InterfaceListener interfaceListener = new InternalInterfaceListener();

	// Enables RA threads on 'connectPoint' with configured IPv6s
	private void activateRouterAdvertisement(ConnectPoint connectPoint, List<InterfaceIpAddress> addresses) {
	synchronized (this) {
	RAWorkerThread worker = new RAWorkerThread(connectPoint, addresses, raThreadDelay);
	ScheduledFuture<?> handler = executors.scheduleAtFixedRate(worker, raThreadDelay,
	raThreadDelay, TimeUnit.SECONDS);
	transmitters.put(connectPoint, handler);
	}

	}

	// Disables already activated RA threads on 'connectPoint'
	private void deactivateRouterAdvertisement(ConnectPoint connectPoint, List<InterfaceIpAddress> addresses) {
	synchronized (this) {
	if (connectPoint != null) {
	ScheduledFuture<?> handler = transmitters.get(connectPoint);
	handler.cancel(false);
	transmitters.remove(connectPoint);
	}
	}
	}

	@Activate
	protected void activate(ComponentContext context) {
	// Basic application registrations.
	appId = coreService.registerApplication(APP_NAME);
	componentConfigService.registerProperties(getClass());

	// Loading configured properties.
	if (context != null) {
	Dictionary<?, ?> properties = context.getProperties();
	try {
	String s = get(properties, PROP_RA_THREADS_POOL);
	raPoolSize = isNullOrEmpty(s) ?
	DEFAULT_RA_THREADS_POOL_SIZE : Integer.parseInt(s.trim());

	s = get(properties, PROP_RA_THREADS_DELAY);
	raThreadDelay = isNullOrEmpty(s) ?
	DEFAULT_RA_THREADS_DELAY : Integer.parseInt(s.trim());

	} catch (NumberFormatException e) {
	log.warn("Component configuration had invalid value, loading default values.", e);
	}
	}

	// Interface listener for dynamic RA handling.
	interfaceService.addListener(interfaceListener);

	// Initialize RA thread pool
	executors = Executors.newScheduledThreadPool(raPoolSize,
	groupedThreads("RouterAdvertisement", "event-%d", log));

	// Start Router Advertisement Transmission for all configured interfaces.
	interfaceService.getInterfaces()
	.stream()
	.filter(i -> mastershipService.getLocalRole(i.connectPoint().deviceId())
	== MastershipRole.MASTER)
	.filter(i -> i.ipAddressesList()
	.stream()
	.anyMatch(ia -> ia.ipAddress().version().equals(IpAddress.Version.INET6)))
	.forEach(j ->
	activateRouterAdvertisement(j.connectPoint(), j.ipAddressesList())
	);
	}

	@Deactivate
	protected void deactivate() {
	// Unregister resources.
	componentConfigService.unregisterProperties(getClass(), false);
	interfaceService.removeListener(interfaceListener);

	// Clear out Router Advertisement Transmission for all configured interfaces.
	interfaceService.getInterfaces()
	.stream()
	.filter(i -> mastershipService.getLocalRole(i.connectPoint().deviceId())
	== MastershipRole.MASTER)
	.filter(i -> i.ipAddressesList()
	.stream()
	.anyMatch(ia -> ia.ipAddress().version().equals(IpAddress.Version.INET6)))
	.forEach(j ->
	deactivateRouterAdvertisement(j.connectPoint(), j.ipAddressesList())
	);
	}

	// Worker thread for actually sending ICMPv6 RA packets.
	private class RAWorkerThread implements Runnable {

	ConnectPoint connectPoint;
	List<InterfaceIpAddress> ipAddresses;
	int retransmitPeriod;

	// Various fixed values in RA packet
	public static final byte RA_HOP_LIMIT = (byte) 0xff;
	public static final short RA_ROUTER_LIFETIME = (short) 1800;
	public static final int RA_OPTIONS_BUFFER_SIZE = 500;
	public static final int RA_OPTION_MTU_VALUE = 1500;
	public static final int RA_OPTION_PREFIX_VALID_LIFETIME = 600;
	public static final int RA_OPTION_PREFIX_PREFERRED_LIFETIME = 600;
	public static final int RA_RETRANSMIT_CALIBRATION_PERIOD = 1;


	RAWorkerThread(ConnectPoint connectPoint, List<InterfaceIpAddress> ipAddresses, int period) {
	this.connectPoint = connectPoint;
	this.ipAddresses = ipAddresses;
	retransmitPeriod = period;
	}

	public void run() {
	// Router Advertisement header filling. Please refer RFC-2461.
	RouterAdvertisement ra = new RouterAdvertisement();
	ra.setCurrentHopLimit(RA_HOP_LIMIT);
	ra.setMFlag((byte) 0x01);
	ra.setOFlag((byte) 0x00);
	ra.setRouterLifetime(RA_ROUTER_LIFETIME);
	ra.setReachableTime(0);
	ra.setRetransmitTimer(retransmitPeriod + RA_RETRANSMIT_CALIBRATION_PERIOD);

	// Option : Source link-layer address.
	byte[] optionBuffer = new byte[RA_OPTIONS_BUFFER_SIZE];
	ByteBuffer option = ByteBuffer.wrap(optionBuffer);
	Optional<MacAddress> macAddress = interfaceService.getInterfacesByPort(connectPoint).stream()
	.map(Interface::mac).findFirst();
	if (!macAddress.isPresent()) {
	log.warn("Unable to retrieve interface {} MAC address. Terminating RA transmission.", connectPoint);
	return;
	}
	option.put(macAddress.get().toBytes());
	ra.addOption(NeighborDiscoveryOptions.TYPE_SOURCE_LL_ADDRESS,
	Arrays.copyOfRange(option.array(), 0, option.position()));

	// Option : MTU.
	option.rewind();
	option.putShort((short) 0);
	option.putInt(RA_OPTION_MTU_VALUE);
	ra.addOption(NeighborDiscoveryOptions.TYPE_MTU,
	Arrays.copyOfRange(option.array(), 0, option.position()));

	// Option : Prefix information.
	ipAddresses.stream()
	.filter(i -> i.ipAddress().version().equals(IpAddress.Version.INET6))
	.forEach(i -> {
	option.rewind();
	option.put((byte) i.subnetAddress().prefixLength());
	// Enable "onlink" option only.
	option.put((byte) 0x80);
	option.putInt(RA_OPTION_PREFIX_VALID_LIFETIME);
	option.putInt(RA_OPTION_PREFIX_PREFERRED_LIFETIME);
	// Clear reserved fields
	option.putInt(0x00000000);
	option.put(IpAddress.makeMaskedAddress(i.ipAddress(),
	i.subnetAddress().prefixLength()).toOctets());
	ra.addOption(NeighborDiscoveryOptions.TYPE_PREFIX_INFORMATION,
	Arrays.copyOfRange(option.array(), 0, option.position()));

	});

	// ICMPv6 header filling.
	ICMP6 icmpv6 = new ICMP6();
	icmpv6.setIcmpType(ICMP6.ROUTER_ADVERTISEMENT);
	icmpv6.setIcmpCode((byte) 0);
	icmpv6.setPayload(ra);

	// IPv6 header filling.
	byte[] ip6AllNodesAddress = Ip6Address.valueOf("ff02::1").toOctets();
	IPv6 ipv6 = new IPv6();
	ipv6.setDestinationAddress(ip6AllNodesAddress);
	/* RA packet L2 source address created from port MAC address.
	* Note : As per RFC-4861 RAs should be sent from link-local address.
	*/
	ipv6.setSourceAddress(IPv6.getLinkLocalAddress(macAddress.get().toBytes()));
	ipv6.setNextHeader(IPv6.PROTOCOL_ICMP6);
	ipv6.setHopLimit(RA_HOP_LIMIT);
	ipv6.setTrafficClass((byte) 0xe0);
	ipv6.setPayload(icmpv6);

	// Ethernet header filling.
	Ethernet ethernet = new Ethernet();

	/* Ethernet IPv6 multicast address creation.
	* Refer : RFC 2624 section 7.
	*/
	byte[] l2Ipv6MulticastAddress = MacAddress.IPV6_MULTICAST.toBytes();
	IntStream.range(1, 4).forEach(i -> l2Ipv6MulticastAddress[l2Ipv6MulticastAddress.length - i] =
	ip6AllNodesAddress[ip6AllNodesAddress.length - i]);

	ethernet.setDestinationMACAddress(MacAddress.valueOf(l2Ipv6MulticastAddress));
	ethernet.setSourceMACAddress(macAddress.get().toBytes());
	ethernet.setEtherType(EthType.EtherType.IPV6.ethType().toShort());
	ethernet.setVlanID(Ethernet.VLAN_UNTAGGED);
	ethernet.setPayload(ipv6);
	ethernet.setPad(false);

	// Flush out PACKET_OUT.
	ByteBuffer stream = ByteBuffer.wrap(ethernet.serialize());
	TrafficTreatment treatment = DefaultTrafficTreatment.builder().setOutput(connectPoint.port()).build();
	OutboundPacket packet = new DefaultOutboundPacket(connectPoint.deviceId(),
	treatment, stream);
	packetService.emit(packet);
	}
	}
	}