openstack/net-virt-providers/src/main/java/org/opendaylight/ovsdb/openstack/netvirt/providers/openflow13/services/LoadBalancerService.java

   1 /*
   2  * Copyright (C) 2014 SDN Hub, LLC.
   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  * Authors : Srini Seetharaman, Madhu Venugopal
   9  */
  10 package org.opendaylight.ovsdb.openstack.netvirt.providers.openflow13.services;
  11
  12 import java.math.BigInteger;
  13 import java.util.List;
  14 import java.util.Map;
  15
  16 import org.opendaylight.ovsdb.openstack.netvirt.NetworkHandler;
  17 import org.opendaylight.ovsdb.openstack.netvirt.api.Constants;
  18 import org.opendaylight.ovsdb.openstack.netvirt.api.LoadBalancerConfiguration;
  19 import org.opendaylight.ovsdb.openstack.netvirt.api.LoadBalancerConfiguration.LoadBalancerPoolMember;
  20 import org.opendaylight.ovsdb.openstack.netvirt.api.LoadBalancerProvider;
  21 import org.opendaylight.ovsdb.openstack.netvirt.api.Status;
  22 import org.opendaylight.ovsdb.openstack.netvirt.api.StatusCode;
  23 import org.opendaylight.ovsdb.openstack.netvirt.providers.openflow13.AbstractServiceInstance;
  24 import org.opendaylight.ovsdb.openstack.netvirt.providers.openflow13.Service;
  25 import org.opendaylight.ovsdb.utils.mdsal.openflow.ActionUtils;
  26 import org.opendaylight.ovsdb.utils.mdsal.openflow.MatchUtils;
  27 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.PortNumber;
  28 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev100924.MacAddress;
  29 import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.Action;
  30 import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.ActionBuilder;
  31 import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.ActionKey;
  32 import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.address.address.Ipv4Builder;
  33 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowId;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.table.FlowBuilder;
  35 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.table.FlowKey;
  36 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.flow.InstructionsBuilder;
  37 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.flow.MatchBuilder;
  38 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.instruction.ApplyActionsCaseBuilder;
  39 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.instruction.apply.actions._case.ApplyActionsBuilder;
  40 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.Instruction;
  41 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.InstructionBuilder;
  42 import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.InstructionKey;
  43 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
  44 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
  45 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeBuilder;
  46 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.l2.types.rev130827.VlanId;
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.match.rev140421.NxmNxReg;
  49 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.match.rev140421.NxmNxReg1;
  50 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.match.rev140421.NxmNxReg2;
  51 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowplugin.extension.nicira.action.rev140714.dst.choice.grouping.dst.choice.DstNxRegCaseBuilder;
  52 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.action.rev140421.OfjNxHashFields;
  53 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.action.rev140421.OfjNxMpAlgorithm;
  54 import org.slf4j.Logger;
  55 import org.slf4j.LoggerFactory;
  56
  57 import com.google.common.collect.Lists;
  58
  59 public class LoadBalancerService extends AbstractServiceInstance implements LoadBalancerProvider {
  60
  61     private static final Logger logger = LoggerFactory.getLogger(LoadBalancerProvider.class);
  62     private static final int DEFAULT_FLOW_PRIORITY = 32768;
  63     private static final Long FIRST_PASS_REGA_MATCH_VALUE = 0L;
  64     private static final Long SECOND_PASS_REGA_MATCH_VALUE = 1L;
  65
  66     private static final Class<? extends NxmNxReg> REG_FIELD_A = NxmNxReg1.class;
  67     private static final Class<? extends NxmNxReg> REG_FIELD_B = NxmNxReg2.class;
  68
  69     public LoadBalancerService() {
  70         super(Service.LOAD_BALANCER);
  71     }
  72
  73     public LoadBalancerService(Service service) {
  74         super(service);
  75     }
  76
  77     /**
  78      * When this method is called, we do the following for minimizing flow updates:
  79      * 1. Overwrite the solo multipath rule that applies to all members
  80      * 2. Append second pass rule for the header rewriting specific to this member
  81      * 3. Append reverse rules specific to this member
  82      */
  83     @Override
  84     public Status programLoadBalancerPoolMemberRules(Node node,
  85             LoadBalancerConfiguration lbConfig, LoadBalancerPoolMember member, org.opendaylight.ovsdb.openstack.netvirt.api.Action action) {
  86         if (lbConfig == null || member == null) {
  87             logger.error("Null value for LB config {} or Member {}", lbConfig, member);
  88             return new Status(StatusCode.BADREQUEST);
  89         }
  90         if (!lbConfig.isValid()) {
  91             logger.error("LB config is invalid: {}", lbConfig);
  92             return new Status(StatusCode.BADREQUEST);
  93         }
  94         logger.debug("Performing {} rules for member {} with index {} on LB with VIP {} and total members {}",
  95                 action, member.getIP(), member.getIndex(), lbConfig.getVip(), lbConfig.getMembers().size());
  96
  97         NodeBuilder nodeBuilder = new NodeBuilder();
  98         nodeBuilder.setId(new NodeId(Constants.OPENFLOW_NODE_PREFIX + node.getId().getValue()));
  99         nodeBuilder.setKey(new NodeKey(nodeBuilder.getId()));
 100
 101         //Update the multipath rule
 102         manageLoadBalancerVIPRulesFirstPass(nodeBuilder, lbConfig, true);
 103
 104         if (action.equals(org.opendaylight.ovsdb.openstack.netvirt.api.Action.ADD)) {
 105             manageLoadBalancerMemberVIPRulesSecondPass(nodeBuilder, lbConfig, member, true);
 106             manageLoadBalancerMemberReverseRules(nodeBuilder, lbConfig, member, true);
 107             return new Status(StatusCode.SUCCESS);
 108         }
 109         /* TODO: Delete single member.
 110          * For now, removing a member requires deleting the full LB instance and re-adding
 111          */
 112         return new Status(StatusCode.NOTIMPLEMENTED);
 113     }
 114
 115     /**
 116      * When this method is called, we perform the following:
 117      * 1. Write the solo multipath rule that applies to all members
 118      * 2. Append second pass rules for the header rewriting for all members
 119      * 3. Append reverse rules for all the members, specific to the protocol/port
 120      */
 121     @Override
 122     public Status programLoadBalancerRules(Node node, LoadBalancerConfiguration lbConfig, org.opendaylight.ovsdb.openstack.netvirt.api.Action action) {
 123         if (lbConfig == null) {
 124             logger.error("LB config is invalid: {}", lbConfig);
 125             return new Status(StatusCode.BADREQUEST);
 126         }
 127         if (!lbConfig.isValid()) {
 128             logger.error("LB config is invalid: {}", lbConfig);
 129             return new Status(StatusCode.BADREQUEST);
 130         }
 131         logger.debug("Performing {} rules for VIP {} and {} members", action, lbConfig.getVip(), lbConfig.getMembers().size());
 132
 133         NodeBuilder nodeBuilder = new NodeBuilder();
 134         nodeBuilder.setId(new NodeId(Constants.OPENFLOW_NODE_PREFIX + node.getId().getValue()));
 135         nodeBuilder.setKey(new NodeKey(nodeBuilder.getId()));
 136
 137         if (action.equals(org.opendaylight.ovsdb.openstack.netvirt.api.Action.ADD)) {
 138             manageLoadBalancerVIPRulesFirstPass(nodeBuilder, lbConfig, true);
 139             manageLoadBalancerVIPRulesSecondPass(nodeBuilder, lbConfig, true);
 140             manageLoadBalancerReverseRules(nodeBuilder, lbConfig, true);
 141             return new Status(StatusCode.SUCCESS);
 142         }
 143         else if (action.equals(org.opendaylight.ovsdb.openstack.netvirt.api.Action.DELETE)) {
 144             manageLoadBalancerVIPRulesFirstPass(nodeBuilder, lbConfig, false);
 145             manageLoadBalancerVIPRulesSecondPass(nodeBuilder, lbConfig, false);
 146             manageLoadBalancerReverseRules(nodeBuilder, lbConfig, false);
 147             return new Status(StatusCode.SUCCESS);
 148         }
 149
 150         return new Status(StatusCode.NOTIMPLEMENTED);
 151     }
 152
 153     /**
 154      * Method to insert/remove default rule for traffic destined to the VIP and no
 155      * server selection performed yet
 156      * @param nodeBuilder NodeBuilder
 157      * @param lbConfig LoadBalancerConfiguration
 158      * @param write Boolean to indicate of the flow is to be inserted or removed
 159      */
 160     private void manageLoadBalancerVIPRulesFirstPass(NodeBuilder nodeBuilder, LoadBalancerConfiguration lbConfig, boolean write) {
 161         MatchBuilder matchBuilder = new MatchBuilder();
 162         FlowBuilder flowBuilder = new FlowBuilder();
 163
 164         // Match Tunnel-ID, VIP, and Reg0==0
 165         if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VXLAN) ||
 166             lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_GRE))
 167             MatchUtils.createTunnelIDMatch(matchBuilder, new BigInteger(lbConfig.getProviderSegmentationId()));
 168         else if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VLAN))
 169             MatchUtils.createVlanIdMatch(matchBuilder, new VlanId(Integer.valueOf(lbConfig.getProviderSegmentationId())), true);
 170         else
 171             return; //Should not get here. TODO: Other types
 172
 173         MatchUtils.createDstL3IPv4Match(matchBuilder, MatchUtils.iPv4PrefixFromIPv4Address(lbConfig.getVip()));
 174         MatchUtils.addNxRegMatch(matchBuilder, new MatchUtils.RegMatch(REG_FIELD_A, FIRST_PASS_REGA_MATCH_VALUE));
 175
 176         String flowId = "LOADBALANCER_FORWARD_FLOW1_" + lbConfig.getVip();
 177         flowBuilder.setId(new FlowId(flowId));
 178         FlowKey key = new FlowKey(new FlowId(flowId));
 179         flowBuilder.setMatch(matchBuilder.build());
 180         flowBuilder.setPriority(DEFAULT_FLOW_PRIORITY);
 181         flowBuilder.setBarrier(true);
 182         flowBuilder.setTableId(this.getTable());
 183         flowBuilder.setKey(key);
 184         flowBuilder.setFlowName(flowId);
 185         flowBuilder.setHardTimeout(0);
 186         flowBuilder.setIdleTimeout(0);
 187
 188         if (write) {
 189             // Create the OF Actions and Instructions
 190             InstructionsBuilder isb = new InstructionsBuilder();
 191
 192             // Instructions List Stores Individual Instructions
 193             List<Instruction> instructions = Lists.newArrayList();
 194
 195             List<Action> actionList = Lists.newArrayList();
 196
 197             ActionBuilder ab = new ActionBuilder();
 198             ab.setAction(ActionUtils.nxLoadRegAction(new DstNxRegCaseBuilder().setNxReg(REG_FIELD_A).build(),
 199                     BigInteger.valueOf(SECOND_PASS_REGA_MATCH_VALUE)));
 200             ab.setOrder(0);
 201             ab.setKey(new ActionKey(0));
 202             actionList.add(ab.build());
 203
 204             ab = new ActionBuilder();
 205             ab.setAction(ActionUtils.nxMultipathAction(OfjNxHashFields.NXHASHFIELDSSYMMETRICL4,
 206                     0, OfjNxMpAlgorithm.NXMPALGMODULON,
 207                     lbConfig.getMembers().size()-1, //By Nicira-Ext spec, this field is max_link minus 1
 208                     0L, new DstNxRegCaseBuilder().setNxReg(REG_FIELD_B).build(),
 209                     0, 31));
 210             ab.setOrder(1);
 211             ab.setKey(new ActionKey(1));
 212             actionList.add(ab.build());
 213
 214             ab = new ActionBuilder();
 215             ab.setAction(ActionUtils.nxResubmitAction(null, this.getTable()));
 216             ab.setOrder(2);
 217             ab.setKey(new ActionKey(2));
 218             actionList.add(ab.build());
 219
 220             // Create an Apply Action
 221             ApplyActionsBuilder aab = new ApplyActionsBuilder();
 222             aab.setAction(actionList);
 223             InstructionBuilder ib = new InstructionBuilder();
 224             ib.setInstruction(new ApplyActionsCaseBuilder().setApplyActions(aab.build()).build());
 225
 226             // Call the InstructionBuilder Methods Containing Actions
 227             ib.setOrder(0);
 228             ib.setKey(new InstructionKey(0));
 229             instructions.add(ib.build());
 230
 231             // Add InstructionBuilder to the Instruction(s)Builder List
 232             isb.setInstruction(instructions);
 233
 234             // Add InstructionsBuilder to FlowBuilder
 235             flowBuilder.setInstructions(isb.build());
 236
 237             writeFlow(flowBuilder, nodeBuilder);
 238
 239         } else {
 240             removeFlow(flowBuilder, nodeBuilder);
 241         }
 242     }
 243
 244     /*
 245      * Method to program each rule that matches on Reg0 and Reg1 to insert appropriate header rewriting
 246      * rules for all members. This function calls manageLoadBalancerMemberVIPRulesSecondPass in turn.
 247      * @param nodeBuilder Node to insert rule to
 248      * @param lbConfig Configuration for this LoadBalancer instance
 249      * @param write Boolean to indicate of the flow is to be inserted or removed
 250      */
 251     private void manageLoadBalancerVIPRulesSecondPass(NodeBuilder nodeBuilder, LoadBalancerConfiguration lbConfig, boolean write) {
 252         for(Map.Entry<String, LoadBalancerPoolMember> entry : lbConfig.getMembers().entrySet()){
 253             manageLoadBalancerMemberVIPRulesSecondPass(nodeBuilder, lbConfig, entry.getValue(), write);
 254         }
 255     }
 256
 257     private void manageLoadBalancerMemberVIPRulesSecondPass(NodeBuilder nodeBuilder, LoadBalancerConfiguration lbConfig, LoadBalancerPoolMember member, boolean write) {
 258         String vip = lbConfig.getVip();
 259
 260         MatchBuilder matchBuilder = new MatchBuilder();
 261         FlowBuilder flowBuilder = new FlowBuilder();
 262
 263         // Match Tunnel-ID, VIP, Reg0==1 and Reg1==Index of member
 264         if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VXLAN) ||
 265             lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_GRE))
 266             MatchUtils.createTunnelIDMatch(matchBuilder, new BigInteger(lbConfig.getProviderSegmentationId()));
 267         else if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VLAN))
 268             MatchUtils.createVlanIdMatch(matchBuilder, new VlanId(Integer.valueOf(lbConfig.getProviderSegmentationId())), true);
 269         else
 270             return; //Should not get here. TODO: Other types
 271
 272         MatchUtils.createDstL3IPv4Match(matchBuilder, MatchUtils.iPv4PrefixFromIPv4Address(vip));
 273         MatchUtils.addNxRegMatch(matchBuilder, new MatchUtils.RegMatch(REG_FIELD_A, SECOND_PASS_REGA_MATCH_VALUE),
 274                                                new MatchUtils.RegMatch(REG_FIELD_B, (long)member.getIndex()));
 275
 276         String flowId = "LOADBALANCER_FORWARD_FLOW2_" + vip + "_" + member.getIP();
 277         flowBuilder.setId(new FlowId(flowId));
 278         FlowKey key = new FlowKey(new FlowId(flowId));
 279         flowBuilder.setMatch(matchBuilder.build());
 280         flowBuilder.setPriority(DEFAULT_FLOW_PRIORITY+1);
 281         flowBuilder.setBarrier(true);
 282         flowBuilder.setTableId(this.getTable());
 283         flowBuilder.setKey(key);
 284         flowBuilder.setFlowName(flowId);
 285         flowBuilder.setHardTimeout(0);
 286         flowBuilder.setIdleTimeout(0);
 287
 288         if (write) {
 289             // Create the OF Actions and Instructions
 290             InstructionsBuilder isb = new InstructionsBuilder();
 291
 292             // Instructions List Stores Individual Instructions
 293             List<Instruction> instructions = Lists.newArrayList();
 294
 295             List<Action> actionList = Lists.newArrayList();
 296             ActionBuilder ab = new ActionBuilder();
 297             ab.setAction(ActionUtils.setDlDstAction(new MacAddress(member.getMAC())));
 298             ab.setOrder(0);
 299             ab.setKey(new ActionKey(0));
 300             actionList.add(ab.build());
 301
 302             ab = new ActionBuilder();
 303             Ipv4Builder ipb = new Ipv4Builder().setIpv4Address(MatchUtils.iPv4PrefixFromIPv4Address(member.getIP()));
 304             ab.setAction(ActionUtils.setNwDstAction(ipb.build()));
 305             ab.setOrder(1);
 306             ab.setKey(new ActionKey(1));
 307             actionList.add(ab.build());
 308
 309             // Create an Apply Action
 310             ApplyActionsBuilder aab = new ApplyActionsBuilder();
 311             aab.setAction(actionList);
 312
 313             // Call the InstructionBuilder Methods Containing Actions
 314             InstructionBuilder ib = new InstructionBuilder();
 315             ib.setInstruction(new ApplyActionsCaseBuilder().setApplyActions(aab.build()).build());
 316             ib.setOrder(0);
 317             ib.setKey(new InstructionKey(0));
 318             instructions.add(ib.build());
 319
 320             // Call the InstructionBuilder Methods Containing Actions
 321             ib = this.getMutablePipelineInstructionBuilder();
 322             ib.setOrder(1);
 323             ib.setKey(new InstructionKey(1));
 324             instructions.add(ib.build());
 325
 326             // Add InstructionBuilder to the Instruction(s)Builder List
 327             isb.setInstruction(instructions);
 328
 329             // Add InstructionsBuilder to FlowBuilder
 330             flowBuilder.setInstructions(isb.build());
 331
 332             writeFlow(flowBuilder, nodeBuilder);
 333
 334         } else {
 335             removeFlow(flowBuilder, nodeBuilder);
 336         }
 337     }
 338
 339     /**
 340      * Method to program all reverse rules that matches member {IP, Protocol, Port} for all members.
 341      * This function calls manageLoadBalancerMemberReverseRules in turn.
 342      * @param nodeBuilder Node to insert rule to
 343      * @param lbConfig Configuration for this LoadBalancer instance
 344      */
 345     private void manageLoadBalancerReverseRules(NodeBuilder nodeBuilder, LoadBalancerConfiguration lbConfig, boolean write) {
 346         for(Map.Entry<String, LoadBalancerPoolMember> entry : lbConfig.getMembers().entrySet()){
 347             manageLoadBalancerMemberReverseRules(nodeBuilder, lbConfig, entry.getValue(), write);
 348         }
 349     }
 350
 351     private void manageLoadBalancerMemberReverseRules(NodeBuilder nodeBuilder, LoadBalancerConfiguration lbConfig,
 352             LoadBalancerPoolMember member, boolean write) {
 353
 354         String vip = lbConfig.getVip();
 355         String vmac = lbConfig.getVmac();
 356
 357         MatchBuilder matchBuilder = new MatchBuilder();
 358         FlowBuilder flowBuilder = new FlowBuilder();
 359
 360         // Match Tunnel-ID, MemberIP, and Protocol/Port
 361         if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VXLAN) ||
 362                    lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_GRE))
 363             MatchUtils.createTunnelIDMatch(matchBuilder, new BigInteger(lbConfig.getProviderSegmentationId()));
 364         else if (lbConfig.getProviderNetworkType().equalsIgnoreCase(NetworkHandler.NETWORK_TYPE_VLAN))
 365             MatchUtils.createVlanIdMatch(matchBuilder, new VlanId(Integer.valueOf(lbConfig.getProviderSegmentationId())), true);
 366         else
 367             return; //Should not get here. TODO: Other types
 368
 369         MatchUtils.createSrcL3IPv4Match(matchBuilder, MatchUtils.iPv4PrefixFromIPv4Address(member.getIP()));
 370         MatchUtils.createSetSrcTcpMatch(matchBuilder, new PortNumber(member.getPort()));
 371
 372         String flowId = "LOADBALANCER_REVERSE_FLOW_" + vip + "_" + member.getIP();
 373         flowBuilder.setId(new FlowId(flowId));
 374         FlowKey key = new FlowKey(new FlowId(flowId));
 375         flowBuilder.setMatch(matchBuilder.build());
 376         flowBuilder.setPriority(DEFAULT_FLOW_PRIORITY);
 377         flowBuilder.setBarrier(true);
 378         flowBuilder.setTableId(this.getTable());
 379         flowBuilder.setKey(key);
 380         flowBuilder.setFlowName(flowId);
 381         flowBuilder.setHardTimeout(0);
 382         flowBuilder.setIdleTimeout(0);
 383
 384         if (write) {
 385             // Create the OF Actions and Instructions
 386             InstructionsBuilder isb = new InstructionsBuilder();
 387
 388             // Instructions List Stores Individual Instructions
 389             List<Instruction> instructions = Lists.newArrayList();
 390
 391             List<Action> actionList = Lists.newArrayList();
 392             ActionBuilder ab = new ActionBuilder();
 393             Ipv4Builder ipb = new Ipv4Builder().setIpv4Address(MatchUtils.iPv4PrefixFromIPv4Address(vip));
 394             ab.setAction(ActionUtils.setNwSrcAction(ipb.build()));
 395             ab.setOrder(0);
 396             ab.setKey(new ActionKey(0));
 397             actionList.add(ab.build());
 398
 399             /* If a dummy MAC is assigned to the VIP, we use that as the
 400              * source MAC for the reverse traffic.
 401              */
 402             if (vmac != null) {
 403                 ab = new ActionBuilder();
 404                 ab.setAction(ActionUtils.setDlDstAction(new MacAddress(vmac)));
 405                 ab.setOrder(1);
 406                 ab.setKey(new ActionKey(1));
 407                 actionList.add(ab.build());
 408             }
 409
 410             // Create an Apply Action
 411             ApplyActionsBuilder aab = new ApplyActionsBuilder();
 412             aab.setAction(actionList);
 413
 414             // Call the InstructionBuilder Methods Containing Actions
 415             InstructionBuilder ib = new InstructionBuilder();
 416             ib.setInstruction(new ApplyActionsCaseBuilder().setApplyActions(aab.build()).build());
 417             ib.setOrder(0);
 418             ib.setKey(new InstructionKey(0));
 419             instructions.add(ib.build());
 420
 421             // Call the InstructionBuilder Methods Containing Actions
 422             ib = this.getMutablePipelineInstructionBuilder();
 423             ib.setOrder(1);
 424             ib.setKey(new InstructionKey(1));
 425             instructions.add(ib.build());
 426
 427             // Add InstructionBuilder to the Instruction(s)Builder List
 428             isb.setInstruction(instructions);
 429
 430             // Add InstructionsBuilder to FlowBuilder
 431             flowBuilder.setInstructions(isb.build());
 432
 433             writeFlow(flowBuilder, nodeBuilder);
 434
 435         } else {
 436             removeFlow(flowBuilder, nodeBuilder);
 437         }
 438     }
 439 }