vpnmanager/impl/src/main/java/org/opendaylight/netvirt/vpnmanager/SubnetRoutePacketInHandler.java

   1 /*
   2  * Copyright (c) 2016, 2018 Ericsson India Global Services Pvt Ltd. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netvirt.vpnmanager;
   9
  10 import static java.util.Collections.emptyList;
  11 import static org.opendaylight.netvirt.vpnmanager.VpnUtil.requireNonNullElse;
  12
  13 import com.google.common.base.Optional;
  14 import com.google.common.primitives.Ints;
  15 import java.math.BigInteger;
  16 import java.net.InetAddress;
  17 import java.net.UnknownHostException;
  18 import java.util.List;
  19 import java.util.concurrent.ExecutionException;
  20 import javax.annotation.Nullable;
  21 import javax.inject.Inject;
  22 import javax.inject.Singleton;
  23 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  24 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  25 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
  26 import org.opendaylight.genius.datastoreutils.SingleTransactionDataBroker;
  27 import org.opendaylight.genius.interfacemanager.interfaces.IInterfaceManager;
  28 import org.opendaylight.genius.mdsalutil.MetaDataUtil;
  29 import org.opendaylight.genius.mdsalutil.NWUtil;
  30 import org.opendaylight.genius.mdsalutil.NwConstants;
  31 import org.opendaylight.genius.mdsalutil.packet.Ethernet;
  32 import org.opendaylight.genius.mdsalutil.packet.IPv4;
  33 import org.opendaylight.infrautils.utils.concurrent.JdkFutures;
  34 import org.opendaylight.netvirt.vpnmanager.api.ICentralizedSwitchProvider;
  35 import org.opendaylight.netvirt.vpnmanager.api.VpnHelper;
  36 import org.opendaylight.netvirt.vpnmanager.iplearn.ipv4.ArpUtils;
  37 import org.opendaylight.netvirt.vpnmanager.utilities.VpnManagerCounters;
  38 import org.opendaylight.openflowplugin.libraries.liblldp.BitBufferHelper;
  39 import org.opendaylight.openflowplugin.libraries.liblldp.BufferException;
  40 import org.opendaylight.openflowplugin.libraries.liblldp.HexEncode;
  41 import org.opendaylight.openflowplugin.libraries.liblldp.Packet;
  42 import org.opendaylight.openflowplugin.libraries.liblldp.PacketException;
  43 import org.opendaylight.yang.gen.v1.urn.huawei.params.xml.ns.yang.l3vpn.rev140815.vpn.interfaces.VpnInterface;
  44 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddressBuilder;
  45 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpPrefix;
  46 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpPrefixBuilder;
  47 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv6Address;
  48 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.MacAddress;
  49 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.Uuid;
  50 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rev160406.IfTunnel;
  51 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.interfacemanager.rpcs.rev160406.OdlInterfaceRpcService;
  52 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.ipv6.nd.util.rev170210.Ipv6NdUtilService;
  53 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.elan.rev150602.elan.tag.name.map.ElanTagName;
  54 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.subnet.op.data.SubnetOpDataEntry;
  55 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.l3vpn.rev130911.vpn.id.to.vpn.instance.VpnIds;
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers.Routers;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.ext.routers.routers.ExternalIps;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.networkmaps.NetworkMap;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.subnetmaps.Subnetmap;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketProcessingListener;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketProcessingService;
  62 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketReceived;
  63 import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.TransmitPacketInput;
  64 import org.slf4j.Logger;
  65 import org.slf4j.LoggerFactory;
  66
  67 @Singleton
  68 public class SubnetRoutePacketInHandler implements PacketProcessingListener {
  69     private static final Logger LOG = LoggerFactory.getLogger(SubnetRoutePacketInHandler.class);
  70     private static final String LOGGING_PREFIX = "SUBNETROUTE:";
  71     private final DataBroker dataBroker;
  72     private final PacketProcessingService packetService;
  73     private final OdlInterfaceRpcService odlInterfaceRpcService;
  74     private final ICentralizedSwitchProvider centralizedSwitchProvider;
  75     private final IInterfaceManager interfaceManager;
  76     private final VpnManagerCounters vpnManagerCounters;
  77     private final Ipv6NdUtilService ipv6NdUtilService;
  78     private final VpnUtil vpnUtil;
  79
  80     @Inject
  81     public SubnetRoutePacketInHandler(final DataBroker dataBroker, final PacketProcessingService packetService,
  82             final OdlInterfaceRpcService odlInterfaceRpcService,
  83             final ICentralizedSwitchProvider centralizedSwitchProvider, final IInterfaceManager interfaceManager,
  84             VpnManagerCounters vpnManagerCounters, final Ipv6NdUtilService ipv6NdUtilService, VpnUtil vpnUtil) {
  85         this.dataBroker = dataBroker;
  86         this.packetService = packetService;
  87         this.odlInterfaceRpcService = odlInterfaceRpcService;
  88         this.centralizedSwitchProvider = centralizedSwitchProvider;
  89         this.interfaceManager = interfaceManager;
  90         this.vpnManagerCounters = vpnManagerCounters;
  91         this.ipv6NdUtilService = ipv6NdUtilService;
  92         this.vpnUtil = vpnUtil;
  93     }
  94
  95     @Override
  96     public void onPacketReceived(PacketReceived notification) {
  97
  98         short tableId = notification.getTableId().getValue();
  99         LOG.trace("{} onPacketReceived: Packet punted from table {}", LOGGING_PREFIX, tableId);
 100         byte[] data = notification.getPayload();
 101         if (notification.getMatch() == null || notification.getMatch().getMetadata() == null) {
 102             LOG.error("{} onPacketReceived: Received from table {} where the match or metadata are null",
 103                     LOGGING_PREFIX, tableId);
 104             return;
 105         }
 106         BigInteger metadata = notification.getMatch().getMetadata().getMetadata();
 107         Ethernet res = new Ethernet();
 108
 109         if (tableId == NwConstants.L3_SUBNET_ROUTE_TABLE) {
 110             LOG.trace("{} onPacketReceived: Some packet received as {}", LOGGING_PREFIX, notification);
 111             try {
 112                 res.deserialize(data, 0, data.length * Byte.SIZE);
 113             } catch (PacketException e) {
 114                 LOG.error("{} onPacketReceived: Failed to decode Packet ", LOGGING_PREFIX, e);
 115                 vpnManagerCounters.subnetRoutePacketFailed();
 116                 return;
 117             }
 118             byte[] srcIpBytes = null;
 119             byte[] dstIpBytes = null;
 120             String srcIpStr;
 121             String dstIpStr;
 122             String srcMac = NWUtil.toStringMacAddress(res.getSourceMACAddress());
 123             try {
 124                 Packet pkt = res.getPayload();
 125                 if (pkt instanceof IPv4) {
 126                     IPv4 ipv4 = (IPv4) pkt;
 127                     srcIpBytes = Ints.toByteArray(ipv4.getSourceAddress());
 128                     dstIpBytes = Ints.toByteArray(ipv4.getDestinationAddress());
 129                     // It is an ARP request on a configured VPN. So we must
 130                     // attempt to respond.
 131                 } else {
 132                     // IPv6 case
 133                     // TODO: IPv6 deserializer
 134                     int ethType = BitBufferHelper.getInt(
 135                             BitBufferHelper.getBits(data, VpnConstants.ETHTYPE_START, VpnConstants.TWO_BYTES));
 136                     if (ethType == VpnConstants.IP_V6_ETHTYPE) {
 137                         srcIpBytes = BitBufferHelper.getBits(data, VpnConstants.IP_V6_HDR_START + 64, 128);
 138                         dstIpBytes = BitBufferHelper.getBits(data, VpnConstants.IP_V6_HDR_START + 192, 128);
 139                     }
 140                 }
 141                 if (srcIpBytes == null || dstIpBytes == null) {
 142                     LOG.trace("{} onPacketReceived: Non-IP packet received as {}", LOGGING_PREFIX, notification);
 143                     return;
 144                 }
 145                 srcIpStr = NWUtil.toStringIpAddress(srcIpBytes);
 146                 dstIpStr = NWUtil.toStringIpAddress(dstIpBytes);
 147
 148                 handleIpPackets(srcIpBytes, dstIpBytes, srcIpStr, dstIpStr, srcMac, metadata);
 149
 150             } catch (UnknownHostException | InterruptedException | ExecutionException | BufferException ex) {
 151                 // Failed to handle packet
 152                 vpnManagerCounters.subnetRoutePacketFailed();
 153                 LOG.error("{} onPacketReceived: Failed to handle subnetroute packet.", LOGGING_PREFIX, ex);
 154             } catch (ReadFailedException e) {
 155                 vpnManagerCounters.subnetRoutePacketFailed();
 156                 LOG.error("{} onPacketReceived: Failed to read data-store.", LOGGING_PREFIX, e);
 157             }
 158             return;
 159         }
 160         // All Arp responses learning for invisble IPs is handled by
 161         // ArpNotificationHandler
 162
 163     }
 164
 165     private void handleIpPackets(byte[] srcIp, byte[] dstIp, String srcIpStr, String dstIpStr, String srcMac,
 166             BigInteger metadata)
 167             throws UnknownHostException, InterruptedException, ExecutionException, ReadFailedException {
 168         long vpnId = MetaDataUtil.getVpnIdFromMetadata(metadata);
 169
 170         LOG.info("{} onPacketReceived: Processing IP Packet received with Source IP {} and Target IP {}"
 171                 + " and vpnId {}", LOGGING_PREFIX, srcIpStr, dstIpStr, vpnId);
 172
 173         Optional<VpnIds> vpnIdsOptional = SingleTransactionDataBroker.syncReadOptional(dataBroker,
 174                 LogicalDatastoreType.CONFIGURATION, VpnUtil.getVpnIdToVpnInstanceIdentifier(vpnId));
 175
 176         if (!vpnIdsOptional.isPresent()) {
 177             // Donot trigger subnetroute logic for packets from
 178             // unknown VPNs
 179             vpnManagerCounters.subnetRoutePacketIgnored();
 180             LOG.info("{} onPacketReceived: Ignoring IPv4 packet with destination Ip {} and source Ip {}"
 181                     + " as it came on unknown VPN with ID {}", LOGGING_PREFIX, dstIpStr, srcIpStr, vpnId);
 182             return;
 183         }
 184
 185         String vpnIdVpnInstanceName = vpnIdsOptional.get().getVpnInstanceName();
 186         if (vpnUtil.getNeutronPortFromVpnPortFixedIp(vpnIdVpnInstanceName, dstIpStr) != null) {
 187             vpnManagerCounters.subnetRoutePacketIgnored();
 188             LOG.info("{} onPacketReceived: IP Packet received with Target IP {} source IP {} vpnId {} "
 189                     + "is a valid Neutron port,ignoring subnet route processing", LOGGING_PREFIX, dstIpStr,
 190                     srcIp, vpnId);
 191             return;
 192         }
 193
 194         if (vpnUtil.getLearntVpnVipToPort(vpnIdVpnInstanceName, dstIpStr) != null) {
 195             vpnManagerCounters.subnetRoutePacketIgnored();
 196             LOG.info("{} onPacketReceived: IP Packet received with Target IP {} source Ip {} vpnId {}"
 197                     + " is an already discovered IPAddress, ignoring subnet route processing",
 198                     LOGGING_PREFIX, dstIpStr, srcIp, vpnId);
 199             return;
 200         }
 201
 202         long elanTag = MetaDataUtil.getElanTagFromMetadata(metadata);
 203         if (elanTag == 0L) {
 204             vpnManagerCounters.subnetRoutePacketFailed();
 205             LOG.error("{} onPacketReceived: elanTag value from metadata found to be 0, for IP "
 206                     + " Packet received with Target IP {} src Ip {} vpnId {}",
 207                     LOGGING_PREFIX, dstIpStr, srcIp, vpnId);
 208             return;
 209         }
 210
 211         if (!vpnIdsOptional.get().isExternalVpn()) {
 212             handleInternalVpnSubnetRoutePacket(metadata, dstIp, srcIpStr, dstIpStr, vpnIdVpnInstanceName,
 213                     elanTag);
 214             return;
 215         }
 216
 217         handleBgpVpnSubnetRoute(srcMac, dstIp, dstIpStr, srcIpStr, elanTag);
 218     }
 219
 220     private void handleBgpVpnSubnetRoute(String srcMac, byte[] dstIp, String dstIpStr, String srcIpStr,
 221             long elanTag) throws UnknownHostException {
 222         LOG.info("{} handleBgpVpnSubnetRoute: Processing IP Packet received with Source IP {} and Target IP {}"
 223                 + " and elan Tag {}", LOGGING_PREFIX, srcIpStr, dstIpStr, elanTag);
 224         SubnetOpDataEntry targetSubnetForPacketOut =
 225                 getTargetSubnetForPacketOut(elanTag, dstIpStr);
 226         if (targetSubnetForPacketOut != null) {
 227             // Handle subnet routes ip requests
 228             transmitArpOrNsPacket(targetSubnetForPacketOut.getNhDpnId(), srcIpStr, srcMac, dstIp, dstIpStr, elanTag);
 229         } else {
 230             vpnManagerCounters.subnetRoutePacketFailed();
 231             LOG.debug("{} handleBgpVpnSubnetRoute: Could not find target subnet for packet out {}", LOGGING_PREFIX,
 232                     dstIpStr);
 233         }
 234     }
 235
 236     private void handleInternalVpnSubnetRoutePacket(BigInteger metadata, byte[] dstIp, String srcIpStr, String dstIpStr,
 237             String vpnIdVpnInstanceName, long elanTag)
 238             throws InterruptedException, ExecutionException, UnknownHostException {
 239         String vmVpnInterfaceName = vpnUtil.getVpnInterfaceName(metadata);
 240         if (isTunnel(vmVpnInterfaceName)) {
 241             handlePacketFromTunnelToExternalNetwork(vpnIdVpnInstanceName, srcIpStr, dstIp, dstIpStr, elanTag);
 242         }
 243         VpnInterface vmVpnInterface = vpnUtil.getVpnInterface(vmVpnInterfaceName);
 244         if (vmVpnInterface == null) {
 245             LOG.error("Vpn interface {} doesn't exist.", vmVpnInterfaceName);
 246             vpnManagerCounters.subnetRoutePacketFailed();
 247             return;
 248         }
 249         if (VpnHelper.doesVpnInterfaceBelongToVpnInstance(vpnIdVpnInstanceName,
 250                vmVpnInterface.getVpnInstanceNames())
 251                && !vpnUtil.isBgpVpnInternet(vpnIdVpnInstanceName)) {
 252             LOG.trace("Unknown IP is in internal network");
 253             handlePacketToInternalNetwork(dstIp, dstIpStr, elanTag);
 254         } else {
 255             LOG.trace("Unknown IP is in external network");
 256             String vpnName = vpnUtil.getInternetVpnFromVpnInstanceList(vmVpnInterface.getVpnInstanceNames());
 257             if (vpnName != null) {
 258                 handlePacketToExternalNetwork(new Uuid(vpnIdVpnInstanceName), vpnName, dstIp, dstIpStr, elanTag);
 259             } else {
 260                 vpnName = VpnHelper.getFirstVpnNameFromVpnInterface(vmVpnInterface);
 261                 LOG.trace("Unknown IP is in external network, but internet VPN not found." + " fallback to first VPN");
 262                 handlePacketToExternalNetwork(new Uuid(vpnIdVpnInstanceName), vpnName, dstIp, dstIpStr, elanTag);
 263
 264             }
 265         }
 266     }
 267
 268     private void transmitArpOrNsPacket(BigInteger dpnId, String sourceIpAddress, String sourceMac, byte[] dstIpBytes,
 269             String dstIpAddress, long elanTag) throws UnknownHostException {
 270         long groupid = VpnUtil.getRemoteBCGroup(elanTag);
 271         if (NWUtil.isIpv4Address(dstIpAddress)) {
 272             LOG.debug("Sending ARP: srcIp={}, srcMac={}, dstIp={}, dpId={}, elan-tag={}, groupid={}", sourceIpAddress,
 273                     sourceMac, dstIpAddress, dpnId, elanTag, groupid);
 274             vpnManagerCounters.subnetRoutePacketArpSent();
 275
 276             TransmitPacketInput packetInput =
 277                     ArpUtils.createArpRequestInput(dpnId, groupid, HexEncode.bytesFromHexString(sourceMac),
 278                             InetAddress.getByName(sourceIpAddress).getAddress(), dstIpBytes);
 279             JdkFutures.addErrorLogging(packetService.transmitPacket(packetInput), LOG, "Transmit packet");
 280         } else {
 281             // IPv6 case
 282             LOG.debug("Sending NS: srcIp={}, srcMac={}, dstIp={}, dpId={}, elan-tag={}, groupid={}", sourceIpAddress,
 283                     sourceMac, dstIpAddress, dpnId, elanTag, groupid);
 284             vpnManagerCounters.subnetRoutePacketNsSent();
 285
 286             VpnUtil.sendNeighborSolicationToOfGroup(this.ipv6NdUtilService, new Ipv6Address(sourceIpAddress),
 287                     new MacAddress(sourceMac), new Ipv6Address(dstIpAddress), groupid, dpnId);
 288         }
 289     }
 290
 291     private void handlePacketToInternalNetwork(byte[] dstIp, String dstIpStr, long elanTag)
 292             throws UnknownHostException {
 293         try {
 294             SubnetOpDataEntry targetSubnetForPacketOut =
 295                     getTargetSubnetForPacketOut(elanTag, dstIpStr);
 296
 297             if (targetSubnetForPacketOut == null) {
 298                 LOG.debug("Couldn't find matching subnet for elan tag {} and destination ip {}", elanTag, dstIpStr);
 299                 vpnManagerCounters.subnetRoutePacketFailed();
 300                 return;
 301             }
 302
 303             Optional<Subnetmap> subnetMap = SingleTransactionDataBroker.syncReadOptional(dataBroker,
 304                     LogicalDatastoreType.CONFIGURATION,
 305                     VpnUtil.buildSubnetmapIdentifier(targetSubnetForPacketOut.getSubnetId()));
 306             if (!subnetMap.isPresent()) {
 307                 LOG.debug("Couldn't find subnet map for subnet {}", targetSubnetForPacketOut.getSubnetId());
 308                 vpnManagerCounters.subnetRoutePacketFailed();
 309                 return;
 310             }
 311
 312             String sourceIp = subnetMap.get().getRouterInterfaceFixedIp();
 313             if (sourceIp == null) {
 314                 LOG.debug("Subnet map {} doesn't have a router interface ip defined", subnetMap.get().getId());
 315                 vpnManagerCounters.subnetRoutePacketFailed();
 316                 return;
 317             }
 318
 319             String sourceMac = subnetMap.get().getRouterIntfMacAddress();
 320             if (sourceMac == null) {
 321                 LOG.debug("Subnet map {} doesn't have a router interface mac address defined",
 322                         subnetMap.get().getId());
 323                 vpnManagerCounters.subnetRoutePacketFailed();
 324                 return;
 325             }
 326
 327             transmitArpOrNsPacket(targetSubnetForPacketOut.getNhDpnId(), sourceIp, sourceMac, dstIp, dstIpStr, elanTag);
 328         } catch (ReadFailedException e) {
 329             LOG.error("handlePacketToInternalNetwork: Failed to read data store for destIp {} elanTag {}", dstIpStr,
 330                     elanTag);
 331         }
 332     }
 333
 334     private void handlePacketFromTunnelToExternalNetwork(String vpnIdVpnInstanceName, String srcIpStr, byte[] dstIp,
 335         String dstIpStr, long elanTag) throws UnknownHostException {
 336         String routerId = vpnUtil.getAssociatedExternalRouter(srcIpStr);
 337         if (null == routerId) {
 338             LOG.debug("This ip is not associated with any external router: {}", srcIpStr);
 339             return;
 340         }
 341         handlePacketToExternalNetwork(new Uuid(vpnIdVpnInstanceName), routerId, dstIp, dstIpStr, elanTag);
 342     }
 343
 344     private void handlePacketToExternalNetwork(Uuid vpnInstanceNameUuid, String routerId, byte[] dstIp, String dstIpStr,
 345             long elanTag) throws UnknownHostException {
 346         Routers externalRouter = vpnUtil.getExternalRouter(routerId);
 347         if (externalRouter == null) {
 348             vpnManagerCounters.subnetRoutePacketFailed();
 349             LOG.debug("{} handlePacketToExternalNetwork: Can't find external router with id {}", LOGGING_PREFIX,
 350                     routerId);
 351             return;
 352         }
 353
 354         List<ExternalIps> externalIps = externalRouter.getExternalIps();
 355         if (externalIps == null || externalIps.isEmpty()) {
 356             vpnManagerCounters.subnetRoutePacketFailed();
 357             LOG.debug("{} handlePacketToExternalNetwork: Router {} doesn't have any external ips.",
 358                     LOGGING_PREFIX, externalRouter.getRouterName());
 359             return;
 360         }
 361
 362         java.util.Optional<ExternalIps> externalIp = externalRouter.getExternalIps().stream()
 363                 .filter(eip -> vpnInstanceNameUuid.equals(eip.getSubnetId())).findFirst();
 364         if (!externalIp.isPresent()) {
 365             vpnManagerCounters.subnetRoutePacketFailed();
 366             LOG.debug("{} handlePacketToExternalNetwork: Router {} doesn't have an external ip for subnet id {}.",
 367                     LOGGING_PREFIX, externalRouter.getRouterName(), vpnInstanceNameUuid);
 368             return;
 369         }
 370
 371         BigInteger dpnId = centralizedSwitchProvider.getPrimarySwitchForRouter(externalRouter.getRouterName());
 372         if (BigInteger.ZERO.equals(dpnId)) {
 373             vpnManagerCounters.subnetRoutePacketFailed();
 374             LOG.debug("{} handlePacketToExternalNetwork: Could not find primary switch for router {}.",
 375                     LOGGING_PREFIX, externalRouter.getRouterName());
 376             return;
 377         }
 378
 379         transmitArpOrNsPacket(dpnId, externalIp.get().getIpAddress(), externalRouter.getExtGwMacAddress(), dstIp,
 380                 dstIpStr, elanTag);
 381     }
 382
 383     // return only the first VPN subnetopdataentry
 384     @Nullable
 385     private SubnetOpDataEntry getTargetSubnetForPacketOut(long elanTag, String ipAddress) {
 386         ElanTagName elanInfo = vpnUtil.getElanInfoByElanTag(elanTag);
 387         if (elanInfo == null) {
 388             LOG.error("{} getTargetDpnForPacketOut: Unable to retrieve ElanInfo for elanTag {}", LOGGING_PREFIX,
 389                     elanTag);
 390             return null;
 391         }
 392         try {
 393             Optional<NetworkMap> optionalNetworkMap = SingleTransactionDataBroker.syncReadOptional(dataBroker,
 394                     LogicalDatastoreType.CONFIGURATION, VpnUtil.buildNetworkMapIdentifier(new Uuid(
 395                             elanInfo.getName())));
 396             if (!optionalNetworkMap.isPresent()) {
 397                 LOG.debug("{} getTargetDpnForPacketOut: No network map found for elan info {}", LOGGING_PREFIX,
 398                         elanInfo.getName());
 399                 return null;
 400             }
 401             List<Uuid> subnetList = requireNonNullElse(optionalNetworkMap.get().getSubnetIdList(), emptyList());
 402             LOG.debug("{} getTargetDpnForPacketOut: Obtained subnetList as {} for network {}", LOGGING_PREFIX,
 403                     subnetList, elanInfo.getName());
 404             for (Uuid subnetId : subnetList) {
 405                 String vpnName = null;
 406                 Subnetmap sn = vpnUtil.getSubnetmapFromItsUuid(subnetId);
 407                 if (sn != null && sn.getVpnId() != null) {
 408                     vpnName = sn.getVpnId().getValue();
 409                 }
 410                 if (vpnName == null) {
 411                     continue;
 412                 }
 413                 Optional<SubnetOpDataEntry> optionalSubs;
 414                 optionalSubs = SingleTransactionDataBroker.syncReadOptional(dataBroker,
 415                         LogicalDatastoreType.OPERATIONAL, VpnUtil.buildSubnetOpDataEntryInstanceIdentifier(subnetId));
 416                 if (!optionalSubs.isPresent()) {
 417                     continue;
 418                 }
 419                 SubnetOpDataEntry subOpEntry = optionalSubs.get();
 420                 if (subOpEntry.getNhDpnId() != null) {
 421                     LOG.trace("{} getTargetDpnForPacketOut: Viewing Subnet {}", LOGGING_PREFIX, subnetId.getValue());
 422                     IpPrefix cidr = IpPrefixBuilder.getDefaultInstance(subOpEntry.getSubnetCidr());
 423                     boolean match = NWUtil.isIpAddressInRange(IpAddressBuilder.getDefaultInstance(ipAddress), cidr);
 424                     LOG.trace("{} getTargetDpnForPacketOut: Viewing Subnet {} matching {}", LOGGING_PREFIX,
 425                             subnetId.getValue(), match);
 426                     if (match) {
 427                         return subOpEntry;
 428                     }
 429                 }
 430             }
 431         } catch (ReadFailedException e) {
 432             LOG.error("{} getTargetDpnForPacketOut: Failed to read data store for elan {}", LOGGING_PREFIX,
 433                     elanInfo.getName());
 434         }
 435         return null;
 436     }
 437
 438     public boolean isTunnel(String interfaceName) {
 439         return interfaceManager.getInterfaceInfoFromConfigDataStore(interfaceName).augmentation(IfTunnel.class) != null;
 440     }
 441 }