neutron-vpp-mapper/src/main/java/org/opendaylight/groupbasedpolicy/neutron/vpp/mapper/processors/PortHandler.java

   1 /*\r
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.\r
   3  *\r
   4  * This program and the accompanying materials are made available under the\r
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,\r
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html\r
   7  */\r
   8 \r
   9 package org.opendaylight.groupbasedpolicy.neutron.vpp.mapper.processors;\r
  10 \r
  11 import java.util.Collections;\r
  12 import java.util.List;\r
  13 \r
  14 import javax.annotation.Nullable;\r
  15 \r
  16 import org.opendaylight.controller.md.sal.binding.api.BindingTransactionChain;\r
  17 import org.opendaylight.controller.md.sal.binding.api.DataBroker;\r
  18 import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;\r
  19 import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;\r
  20 import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;\r
  21 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;\r
  22 import org.opendaylight.controller.md.sal.common.api.data.TransactionChain;\r
  23 import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;\r
  24 import org.opendaylight.groupbasedpolicy.neutron.vpp.mapper.SocketInfo;\r
  25 import org.opendaylight.groupbasedpolicy.util.DataStoreHelper;\r
  26 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpPrefix;\r
  27 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Prefix;\r
  28 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.PhysAddress;\r
  29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.Uuid;\r
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.common.rev140421.UniqueId;\r
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.neutron.gbp.mapper.rev150513.Mappings;\r
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.neutron.gbp.mapper.rev150513.mappings.GbpByNeutronMappings;\r
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.neutron.gbp.mapper.rev150513.mappings.gbp.by.neutron.mappings.BaseEndpointsByPorts;\r
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.neutron.gbp.mapper.rev150513.mappings.gbp.by.neutron.mappings.base.endpoints.by.ports.BaseEndpointByPort;\r
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.neutron.gbp.mapper.rev150513.mappings.gbp.by.neutron.mappings.base.endpoints.by.ports.BaseEndpointByPortKey;\r
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425.Config;\r
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425._interface.attributes._interface.type.choice.LoopbackCase;\r
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425._interface.attributes._interface.type.choice.LoopbackCaseBuilder;\r
  39 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425._interface.attributes._interface.type.choice.TapCase;\r
  40 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425._interface.attributes._interface.type.choice.TapCaseBuilder;\r
  41 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425._interface.attributes._interface.type.choice.VhostUserCaseBuilder;\r
  42 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425.config.VppEndpoint;\r
  43 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425.config.VppEndpointBuilder;\r
  44 import org.opendaylight.yang.gen.v1.urn.opendaylight.groupbasedpolicy.vpp_renderer.rev160425.config.VppEndpointKey;\r
  45 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.binding.rev150712.PortBindingExtension;\r
  46 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.binding.rev150712.binding.attributes.VifDetails;\r
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.rev150712.routers.attributes.Routers;\r
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.rev150712.routers.attributes.routers.Router;\r
  49 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.rev150712.routers.attributes.routers.RouterKey;\r
  50 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.port.attributes.FixedIps;\r
  51 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.Ports;\r
  52 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.ports.Port;\r
  53 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.ports.rev150712.ports.attributes.ports.PortKey;\r
  54 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.rev150712.Neutron;\r
  55 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.Subnets;\r
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.subnets.Subnet;\r
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.subnets.SubnetKey;\r
  58 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NodeId;\r
  59 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;\r
  60 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier.InstanceIdentifierBuilder;\r
  61 import org.slf4j.Logger;\r
  62 import org.slf4j.LoggerFactory;\r
  63 \r
  64 import com.google.common.annotations.VisibleForTesting;\r
  65 import com.google.common.base.Optional;\r
  66 \r
  67 public class PortHandler implements TransactionChainListener {\r
  68 \r
  69     private static final Logger LOG = LoggerFactory.getLogger(PortHandler.class);\r
  70 \r
  71     private static final String COMPUTE_OWNER = "compute";\r
  72     private static final String DHCP_OWNER = "dhcp";\r
  73     private static final String ROUTER_OWNER = "network:router_interface";\r
  74     private static final String[] SUPPORTED_DEVICE_OWNERS = {COMPUTE_OWNER, DHCP_OWNER, ROUTER_OWNER};\r
  75     private static final String VHOST_USER = "vhostuser";\r
  76     private static final String UNBOUND = "unbound";\r
  77     private static final String VPP_INTERFACE_NAME_PREFIX = "neutron_port_";\r
  78     private static final String TAP_PORT_NAME_PREFIX = "tap";\r
  79     private static final String RT_PORT_NAME_PREFIX = "qr-";\r
  80 \r
  81     private BindingTransactionChain transactionChain;\r
  82     private DataBroker dataBroker;\r
  83     private SocketInfo socketInfo;\r
  84 \r
  85     PortHandler(DataBroker dataBroker, SocketInfo socketInfo) {\r
  86         this.dataBroker = dataBroker;\r
  87         this.socketInfo = socketInfo;\r
  88         transactionChain = this.dataBroker.createTransactionChain(this);\r
  89     }\r
  90 \r
  91     void processCreated(Port port) {\r
  92         ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
  93         Optional<BaseEndpointByPort> optBaseEpByPort = DataStoreHelper.readFromDs(LogicalDatastoreType.OPERATIONAL,\r
  94                 createBaseEpByPortIid(port.getUuid()), rTx);\r
  95         rTx.close();\r
  96         if (!optBaseEpByPort.isPresent()) {\r
  97             return;\r
  98         }\r
  99         processCreatedData(port, optBaseEpByPort.get());\r
 100     }\r
 101 \r
 102     void processCreated(BaseEndpointByPort bebp) {\r
 103         ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
 104         Optional<Port> optPort = DataStoreHelper.readFromDs(LogicalDatastoreType.CONFIGURATION,\r
 105                 createPortIid(bebp.getPortId()), rTx);\r
 106         rTx.close();\r
 107         if (!optPort.isPresent()) {\r
 108             return;\r
 109         }\r
 110         processCreatedData(optPort.get(), bebp);\r
 111     }\r
 112 \r
 113     @VisibleForTesting\r
 114     void processCreatedData(Port port, BaseEndpointByPort bebp) {\r
 115         if (isValidVhostUser(port)) {\r
 116             VppEndpoint vppEp = buildVppEndpoint(port, bebp);\r
 117             writeVppEndpoint(createVppEndpointIid(vppEp.getKey()), vppEp);\r
 118             LOG.debug("Created vpp-endpoint {}", vppEp);\r
 119         }\r
 120     }\r
 121 \r
 122     private boolean isValidVhostUser(Port port) {\r
 123         PortBindingExtension portBindingExt = port.getAugmentation(PortBindingExtension.class);\r
 124         if (portBindingExt != null) {\r
 125             String vifType = portBindingExt.getVifType();\r
 126             String deviceOwner = port.getDeviceOwner();\r
 127             if (vifType != null && deviceOwner != null) {\r
 128                 if (vifType.contains(VHOST_USER)) {\r
 129                     for (String supportedDeviceOwner : SUPPORTED_DEVICE_OWNERS) {\r
 130                         if (deviceOwner.contains(supportedDeviceOwner)) {\r
 131                             return true;\r
 132                         }\r
 133                     }\r
 134                 }\r
 135             }\r
 136         }\r
 137         return false;\r
 138     }\r
 139 \r
 140     void processUpdated(Port original, Port delta) {\r
 141         if (!isUpdateNeeded(original, delta)){\r
 142             LOG.trace("Port update skipped, port didn`t change. before {}, after: {}" , original, delta);\r
 143             return;\r
 144         }\r
 145 \r
 146         LOG.trace("Updating port before: {}, after: {}" , original, delta);\r
 147         if (isValidVhostUser(original)) {\r
 148             ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
 149             Optional<BaseEndpointByPort> optBebp = DataStoreHelper.readFromDs(LogicalDatastoreType.OPERATIONAL,\r
 150                     createBaseEpByPortIid(original.getUuid()), rTx);\r
 151             rTx.close();\r
 152             if (!optBebp.isPresent()) {\r
 153                 return;\r
 154             }\r
 155             LOG.trace("Updating port - deleting old port {}" , optBebp.get().getPortId());\r
 156             processDeleted(optBebp.get());\r
 157         }\r
 158         LOG.trace("Updating port - creating new port {}" , delta.getUuid());\r
 159         processCreated(delta);\r
 160     }\r
 161 \r
 162     private boolean isUpdateNeeded(final Port oldPort, final Port newPort) {\r
 163         //TODO fix this to better support update of ports for VPP\r
 164         final PortBindingExtension oldPortAugmentation = oldPort.getAugmentation(PortBindingExtension.class);\r
 165         final PortBindingExtension newPortAugmentation = newPort.getAugmentation(PortBindingExtension.class);\r
 166 \r
 167         if (newPortAugmentation == null) {\r
 168             LOG.trace("Port {} is no longer a vhost type port, updating port...");\r
 169             return true;\r
 170         }\r
 171 \r
 172         final String oldDeviceOwner = oldPort.getDeviceOwner();\r
 173         final String oldVifType = oldPortAugmentation.getVifType();\r
 174         final String newDeviceOwner = newPort.getDeviceOwner();\r
 175         final String newVifType = newPortAugmentation.getVifType();\r
 176 \r
 177         // TODO potential bug here\r
 178         // Temporary change for Openstack Mitaka: If old neutron-binding:vif-type is vhost, new one is unbound and\r
 179         // device owner is ROUTER_OWNER, skip update. Openstack (or ml2) sometimes sends router update messages in\r
 180         // incorrect order which causes unwanted port removal\r
 181         if (oldVifType.equals(VHOST_USER) && newVifType.equals(UNBOUND) && oldDeviceOwner != null &&\r
 182                 ROUTER_OWNER.equals(oldDeviceOwner) && ROUTER_OWNER.equals(newDeviceOwner)) {\r
 183             LOG.warn("Port vif-type was updated from vhost to unbound. This update is currently disabled and will be skipped");\r
 184             return false;\r
 185         }\r
 186 \r
 187         if (newVifType != null && !newVifType.equals(oldVifType)) {\r
 188             LOG.trace("Vif type changed, old: {} new {}", oldVifType, newVifType);\r
 189             return true;\r
 190         }\r
 191 \r
 192         final List<VifDetails> vifDetails = oldPortAugmentation.getVifDetails();\r
 193 \r
 194         if (!oldPortAugmentation.getHostId().equals(newPortAugmentation.getHostId()) ||\r
 195             nullToEmpty(vifDetails).size() != nullToEmpty(newPortAugmentation.getVifDetails()).size()) {\r
 196             return true;\r
 197         }\r
 198 \r
 199         for (VifDetails vifDetail : nullToEmpty(vifDetails)) {\r
 200             //check if vhostuser_socket, vhostuser_mode and port_filter are changed\r
 201             if (!newPortAugmentation.getVifDetails().contains(vifDetail))\r
 202                 return true;\r
 203         }\r
 204         return false;\r
 205     }\r
 206 \r
 207     void processDeleted(BaseEndpointByPort bebp) {\r
 208         LOG.trace("Deleting vpp-endpoint by BaseEndpointByPort {}" , bebp);\r
 209         VppEndpointKey vppEpKey = new VppEndpointKey(bebp.getAddress(), bebp.getAddressType(), bebp.getContextId(),\r
 210                 bebp.getContextType());\r
 211         InstanceIdentifier<VppEndpoint> vppEpIid = createVppEndpointIid(vppEpKey);\r
 212         ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
 213         Optional<VppEndpoint> readVppEp = DataStoreHelper.readFromDs(LogicalDatastoreType.CONFIGURATION, vppEpIid, rTx);\r
 214         rTx.close();\r
 215         if (readVppEp.isPresent()) {\r
 216             writeVppEndpoint(vppEpIid, null);\r
 217             LOG.debug("Deleted vpp-endpoint {}", vppEpKey);\r
 218         }\r
 219     }\r
 220 \r
 221     private synchronized void writeVppEndpoint(InstanceIdentifier<VppEndpoint> vppEpIid, VppEndpoint vppEp) {\r
 222         WriteTransaction wTx = transactionChain.newWriteOnlyTransaction();\r
 223         if (vppEp != null) {\r
 224             wTx.put(LogicalDatastoreType.CONFIGURATION, vppEpIid, vppEp, true);\r
 225         } else {\r
 226             wTx.delete(LogicalDatastoreType.CONFIGURATION, vppEpIid);\r
 227         }\r
 228         wTx.submit();\r
 229     }\r
 230 \r
 231     @VisibleForTesting\r
 232     VppEndpoint buildVppEndpoint(Port port, BaseEndpointByPort bebp) {\r
 233         PortBindingExtension portBinding = port.getAugmentation(PortBindingExtension.class);\r
 234         VppEndpointBuilder vppEpBuilder = new VppEndpointBuilder().setDescription("neutron port")\r
 235             .setContextId(bebp.getContextId())\r
 236             .setContextType(bebp.getContextType())\r
 237             .setAddress(bebp.getAddress())\r
 238             .setAddressType(bebp.getAddressType())\r
 239             .setVppInterfaceName(VPP_INTERFACE_NAME_PREFIX + bebp.getPortId().getValue())\r
 240             .setVppNodeId(new NodeId(portBinding.getHostId()));\r
 241         if (port.getDeviceOwner().contains(COMPUTE_OWNER)) {\r
 242             String socket = socketInfo.getSocketPath() + socketInfo.getSocketPrefix() + bebp.getPortId().getValue();\r
 243             vppEpBuilder.setInterfaceTypeChoice(new VhostUserCaseBuilder().setSocket(socket).build());\r
 244         } else if (port.getDeviceOwner().contains(DHCP_OWNER) && port.getMacAddress() != null) {\r
 245             TapCase tapCase = new TapCaseBuilder().setPhysicalAddress(new PhysAddress(port.getMacAddress().getValue()))\r
 246                 .setName(createPortName(port.getUuid()))\r
 247                 .build();\r
 248             vppEpBuilder.setInterfaceTypeChoice(tapCase);\r
 249         } else if (isValidQRouterPort(port)) {\r
 250             TapCase tapCase = new TapCaseBuilder().setPhysicalAddress(new PhysAddress(port.getMacAddress().getValue()))\r
 251                     .setName(createQRouterPortName(port.getUuid()))\r
 252                     .build();\r
 253             vppEpBuilder.setInterfaceTypeChoice(tapCase);\r
 254         } else if (isValidVppRouterPort(port)) {\r
 255             vppEpBuilder.setInterfaceTypeChoice(getLoopbackCase(port));\r
 256         }\r
 257         return vppEpBuilder.build();\r
 258     }\r
 259 \r
 260     private LoopbackCase getLoopbackCase(Port port) {\r
 261         LoopbackCaseBuilder loopbackCase = new LoopbackCaseBuilder()\r
 262             .setPhysAddress(new PhysAddress(port.getMacAddress().getValue()));\r
 263         Optional<FixedIps> fixedIpsOptional = resolveFirstFixedIps(port);\r
 264         if(fixedIpsOptional.isPresent() && fixedIpsOptional.get().getIpAddress() != null){\r
 265             loopbackCase.setIpAddress(fixedIpsOptional.get().getIpAddress());\r
 266             ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
 267             Optional<Subnet> subnetOptional =\r
 268                 DataStoreHelper.readFromDs(LogicalDatastoreType.CONFIGURATION,\r
 269                     InstanceIdentifier.builder(Neutron.class)\r
 270                         .child(Subnets.class)\r
 271                         .child(Subnet.class, new SubnetKey(fixedIpsOptional.get().getSubnetId()))\r
 272                         .build(), rTx);\r
 273             if (subnetOptional.isPresent()) {\r
 274                 Ipv4Prefix ipv4Prefix = subnetOptional.get().getCidr().getIpv4Prefix();\r
 275                 loopbackCase.setIpPrefix(new IpPrefix(ipv4Prefix));\r
 276             } else {\r
 277                 LOG.warn("IpPrefix for loopback port: {} was not set.", port);\r
 278             }\r
 279             if (loopbackCase.getIpAddress() != null && loopbackCase.getIpPrefix() != null) {\r
 280                 loopbackCase.setBvi(true);\r
 281                 LOG.trace("Creating loopback BVI interface: {} for VPP router port: {}.", loopbackCase, port);\r
 282             }\r
 283 \r
 284         } else {\r
 285             LOG.warn("IpAddress for loopback port: {} was not set.", port);\r
 286         }\r
 287         return loopbackCase.build();\r
 288     }\r
 289 \r
 290     /**\r
 291      * If Qrouter (L3 Agent) is in use, any of Openstack neutron routers is not going be mapped\r
 292      * to ODL neutron.\r
 293      */\r
 294     private boolean isValidQRouterPort(Port port) {\r
 295         Optional<Router> optRouter = getRouterOptional(port);\r
 296         return !optRouter.isPresent() && port.getDeviceOwner().contains(ROUTER_OWNER)\r
 297                 && port.getMacAddress() != null;\r
 298     }\r
 299 \r
 300     private boolean isValidVppRouterPort(Port port) {\r
 301         Optional<Router> optRouter = getRouterOptional(port);\r
 302         return optRouter.isPresent() && port.getDeviceOwner().contains(ROUTER_OWNER)\r
 303             && port.getMacAddress() != null;\r
 304     }\r
 305 \r
 306     private Optional<Router> getRouterOptional(Port port) {\r
 307         ReadOnlyTransaction rTx = transactionChain.newReadOnlyTransaction();\r
 308         InstanceIdentifier<Router> routerIid = InstanceIdentifier.builder(Neutron.class)\r
 309             .child(Routers.class)\r
 310             .child(Router.class, new RouterKey(new Uuid(port.getDeviceId())))\r
 311             .build();\r
 312         Optional<Router> optRouter = DataStoreHelper.readFromDs(LogicalDatastoreType.CONFIGURATION, routerIid, rTx);\r
 313         rTx.close();\r
 314         return optRouter;\r
 315     }\r
 316 \r
 317     public static Optional<FixedIps> resolveFirstFixedIps(Port port) {\r
 318         List<FixedIps> fixedIps = port.getFixedIps();\r
 319         if (fixedIps != null && !fixedIps.isEmpty()) {\r
 320             return Optional.of(fixedIps.get(0));\r
 321         }\r
 322         return Optional.absent();\r
 323     }\r
 324 \r
 325     private String createPortName(Uuid portUuid) {\r
 326         String tapPortName;\r
 327         String uuid = portUuid.getValue();\r
 328         if (uuid != null && uuid.length() >= 12) {\r
 329             tapPortName = TAP_PORT_NAME_PREFIX + uuid.substring(0, 11);\r
 330         } else {\r
 331             tapPortName = TAP_PORT_NAME_PREFIX + uuid;\r
 332         }\r
 333         return tapPortName;\r
 334     }\r
 335 \r
 336     private String createQRouterPortName(Uuid portUuid) {\r
 337         String tapPortName;\r
 338         String uuid = portUuid.getValue();\r
 339         if (uuid != null && uuid.length() >= 12) {\r
 340             tapPortName = RT_PORT_NAME_PREFIX + uuid.substring(0, 11);\r
 341         } else {\r
 342             tapPortName = RT_PORT_NAME_PREFIX + uuid;\r
 343         }\r
 344         return tapPortName;\r
 345     }\r
 346 \r
 347     private InstanceIdentifier<VppEndpoint> createVppEndpointIid(VppEndpointKey vppEpKey) {\r
 348         return InstanceIdentifier.builder(Config.class).child(VppEndpoint.class, vppEpKey).build();\r
 349     }\r
 350 \r
 351     private InstanceIdentifier<BaseEndpointByPort> createBaseEpByPortIid(Uuid uuid) {\r
 352         return createBaseEpByPortIid(new UniqueId(uuid.getValue()));\r
 353     }\r
 354 \r
 355     private InstanceIdentifier<BaseEndpointByPort> createBaseEpByPortIid(UniqueId uuid) {\r
 356         return InstanceIdentifier.builder(Mappings.class)\r
 357             .child(GbpByNeutronMappings.class)\r
 358             .child(BaseEndpointsByPorts.class)\r
 359             .child(BaseEndpointByPort.class, new BaseEndpointByPortKey(uuid))\r
 360             .build();\r
 361     }\r
 362 \r
 363     InstanceIdentifier<Port> createWildcartedPortIid() {\r
 364         return portsIid().child(Port.class).build();\r
 365     }\r
 366 \r
 367     private InstanceIdentifier<Port> createPortIid(UniqueId uuid) {\r
 368         return portsIid().child(Port.class, new PortKey(new Uuid(uuid.getValue()))).build();\r
 369     }\r
 370 \r
 371     private InstanceIdentifierBuilder<Ports> portsIid() {\r
 372         return InstanceIdentifier.builder(Neutron.class).child(Ports.class);\r
 373     }\r
 374 \r
 375     @Override\r
 376     public void onTransactionChainFailed(TransactionChain<?, ?> chain, AsyncTransaction<?, ?> transaction,\r
 377             Throwable cause) {\r
 378         LOG.error("Transaction chain failed. {} \nTransaction which caused the chain to fail {}", cause.getMessage(),\r
 379                 transaction, cause);\r
 380         transactionChain.close();\r
 381         transactionChain = dataBroker.createTransactionChain(this);\r
 382     }\r
 383 \r
 384     @Override\r
 385     public void onTransactionChainSuccessful(TransactionChain<?, ?> chain) {\r
 386         LOG.trace("Transaction chain was successful. {}", chain);\r
 387     }\r
 388 \r
 389     private <T> List<T> nullToEmpty(@Nullable List<T> list) {\r
 390         return list == null ? Collections.emptyList() : list;\r
 391     }\r
 392 }\r