/* * Copyright 2015 Open Networking Laboratory * * 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.driver.pipeline; import com.google.common.cache.Cache; import com.google.common.cache.CacheBuilder; import com.google.common.cache.RemovalCause; import com.google.common.cache.RemovalNotification; import org.onlab.osgi.ServiceDirectory; import org.onlab.packet.Ethernet; import org.onlab.packet.IPv4; import org.onlab.packet.MacAddress; import org.onlab.packet.VlanId; import org.onlab.util.KryoNamespace; import org.onosproject.core.ApplicationId; import org.onosproject.core.CoreService; import org.onosproject.net.DeviceId; import org.onosproject.net.behaviour.NextGroup; import org.onosproject.net.behaviour.Pipeliner; import org.onosproject.net.behaviour.PipelinerContext; import org.onosproject.net.driver.AbstractHandlerBehaviour; import org.onosproject.net.flow.DefaultFlowRule; import org.onosproject.net.flow.DefaultTrafficSelector; import org.onosproject.net.flow.DefaultTrafficTreatment; import org.onosproject.net.flow.FlowRule; import org.onosproject.net.flow.FlowRuleOperations; import org.onosproject.net.flow.FlowRuleOperationsContext; import org.onosproject.net.flow.FlowRuleService; import org.onosproject.net.flow.TrafficSelector; import org.onosproject.net.flow.TrafficTreatment; import org.onosproject.net.flow.criteria.Criteria; import org.onosproject.net.flow.criteria.Criterion; import org.onosproject.net.flow.criteria.EthCriterion; import org.onosproject.net.flow.criteria.EthTypeCriterion; import org.onosproject.net.flow.criteria.IPCriterion; import org.onosproject.net.flow.criteria.IPProtocolCriterion; import org.onosproject.net.flow.criteria.PortCriterion; import org.onosproject.net.flow.criteria.VlanIdCriterion; import org.onosproject.net.flowobjective.FilteringObjective; import org.onosproject.net.flowobjective.FlowObjectiveStore; import org.onosproject.net.flowobjective.ForwardingObjective; import org.onosproject.net.flowobjective.NextObjective; import org.onosproject.net.flowobjective.Objective; import org.onosproject.net.flowobjective.ObjectiveError; import org.onosproject.net.group.DefaultGroupBucket; import org.onosproject.net.group.DefaultGroupDescription; import org.onosproject.net.group.DefaultGroupKey; import org.onosproject.net.group.Group; import org.onosproject.net.group.GroupBucket; import org.onosproject.net.group.GroupBuckets; import org.onosproject.net.group.GroupDescription; import org.onosproject.net.group.GroupEvent; import org.onosproject.net.group.GroupKey; import org.onosproject.net.group.GroupListener; import org.onosproject.net.group.GroupService; import org.slf4j.Logger; import java.util.Collection; import java.util.Collections; import java.util.Set; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import java.util.stream.Collectors; import static org.onlab.util.Tools.groupedThreads; import static org.slf4j.LoggerFactory.getLogger; /** * OpenvSwitch emulation of the Corsa pipeline handler. */ public class OVSCorsaPipeline extends AbstractHandlerBehaviour implements Pipeliner { protected static final int MAC_TABLE = 0; protected static final int VLAN_MPLS_TABLE = 1; protected static final int VLAN_TABLE = 2; //protected static final int MPLS_TABLE = 3; protected static final int ETHER_TABLE = 4; protected static final int COS_MAP_TABLE = 5; protected static final int FIB_TABLE = 6; protected static final int LOCAL_TABLE = 9; protected static final int CONTROLLER_PRIORITY = 255; private static final int DROP_PRIORITY = 0; private static final int HIGHEST_PRIORITY = 0xffff; private final Logger log = getLogger(getClass()); private ServiceDirectory serviceDirectory; protected FlowRuleService flowRuleService; private CoreService coreService; private GroupService groupService; private FlowObjectiveStore flowObjectiveStore; protected DeviceId deviceId; protected ApplicationId appId; private KryoNamespace appKryo = new KryoNamespace.Builder() .register(GroupKey.class) .register(DefaultGroupKey.class) .register(CorsaGroup.class) .register(byte[].class) .build(); private Cache pendingGroups; private ScheduledExecutorService groupChecker = Executors.newScheduledThreadPool(2, groupedThreads("onos/pipeliner", "ovs-corsa-%d")); @Override public void init(DeviceId deviceId, PipelinerContext context) { this.serviceDirectory = context.directory(); this.deviceId = deviceId; pendingGroups = CacheBuilder.newBuilder() .expireAfterWrite(20, TimeUnit.SECONDS) .removalListener((RemovalNotification notification) -> { if (notification.getCause() == RemovalCause.EXPIRED) { fail(notification.getValue(), ObjectiveError.GROUPINSTALLATIONFAILED); } }).build(); groupChecker.scheduleAtFixedRate(new GroupChecker(), 0, 500, TimeUnit.MILLISECONDS); coreService = serviceDirectory.get(CoreService.class); flowRuleService = serviceDirectory.get(FlowRuleService.class); groupService = serviceDirectory.get(GroupService.class); flowObjectiveStore = context.store(); groupService.addListener(new InnerGroupListener()); appId = coreService.registerApplication( "org.onosproject.driver.OVSCorsaPipeline"); initializePipeline(); } @Override public void filter(FilteringObjective filteringObjective) { if (filteringObjective.type() == FilteringObjective.Type.PERMIT) { processFilter(filteringObjective, filteringObjective.op() == Objective.Operation.ADD, filteringObjective.appId()); } else { fail(filteringObjective, ObjectiveError.UNSUPPORTED); } } @Override public void forward(ForwardingObjective fwd) { Collection rules; FlowRuleOperations.Builder flowBuilder = FlowRuleOperations.builder(); rules = processForward(fwd); switch (fwd.op()) { case ADD: rules.stream() .filter(rule -> rule != null) .forEach(flowBuilder::add); break; case REMOVE: rules.stream() .filter(rule -> rule != null) .forEach(flowBuilder::remove); break; default: fail(fwd, ObjectiveError.UNKNOWN); log.warn("Unknown forwarding type {}", fwd.op()); } flowRuleService.apply(flowBuilder.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { pass(fwd); } @Override public void onError(FlowRuleOperations ops) { fail(fwd, ObjectiveError.FLOWINSTALLATIONFAILED); } })); } @Override public void next(NextObjective nextObjective) { switch (nextObjective.type()) { case SIMPLE: Collection treatments = nextObjective.next(); if (treatments.size() == 1) { TrafficTreatment treatment = treatments.iterator().next(); GroupBucket bucket = DefaultGroupBucket.createIndirectGroupBucket(treatment); final GroupKey key = new DefaultGroupKey(appKryo.serialize(nextObjective.id())); GroupDescription groupDescription = new DefaultGroupDescription(deviceId, GroupDescription.Type.INDIRECT, new GroupBuckets(Collections .singletonList(bucket)), key, null, // let group service determine group id nextObjective.appId()); groupService.addGroup(groupDescription); pendingGroups.put(key, nextObjective); } break; case HASHED: case BROADCAST: case FAILOVER: fail(nextObjective, ObjectiveError.UNSUPPORTED); log.warn("Unsupported next objective type {}", nextObjective.type()); break; default: fail(nextObjective, ObjectiveError.UNKNOWN); log.warn("Unknown next objective type {}", nextObjective.type()); } } private Collection processForward(ForwardingObjective fwd) { switch (fwd.flag()) { case SPECIFIC: return processSpecific(fwd); case VERSATILE: return processVersatile(fwd); default: fail(fwd, ObjectiveError.UNKNOWN); log.warn("Unknown forwarding flag {}", fwd.flag()); } return Collections.emptySet(); } private Collection processVersatile(ForwardingObjective fwd) { log.debug("Processing versatile forwarding objective"); TrafficSelector selector = fwd.selector(); EthTypeCriterion ethType = (EthTypeCriterion) selector.getCriterion(Criterion.Type.ETH_TYPE); if (ethType == null) { log.error("Versatile forwarding objective must include ethType"); fail(fwd, ObjectiveError.UNKNOWN); return Collections.emptySet(); } if (ethType.ethType().toShort() == Ethernet.TYPE_ARP) { log.warn("Driver automatically handles ARP packets by punting to controller " + " from ETHER table"); pass(fwd); return Collections.emptySet(); } else if (ethType.ethType().toShort() == Ethernet.TYPE_LLDP || ethType.ethType().toShort() == Ethernet.TYPE_BSN) { log.warn("Driver currently does not currently handle LLDP packets"); fail(fwd, ObjectiveError.UNSUPPORTED); return Collections.emptySet(); } else if (ethType.ethType().toShort() == Ethernet.TYPE_IPV4) { IPCriterion ipSrc = (IPCriterion) selector .getCriterion(Criterion.Type.IPV4_SRC); IPCriterion ipDst = (IPCriterion) selector .getCriterion(Criterion.Type.IPV4_DST); IPProtocolCriterion ipProto = (IPProtocolCriterion) selector .getCriterion(Criterion.Type.IP_PROTO); if (ipSrc != null) { log.warn("Driver does not currently handle matching Src IP"); fail(fwd, ObjectiveError.UNSUPPORTED); return Collections.emptySet(); } if (ipDst != null) { log.error("Driver handles Dst IP matching as specific forwarding " + "objective, not versatile"); fail(fwd, ObjectiveError.UNSUPPORTED); return Collections.emptySet(); } if (ipProto != null && ipProto.protocol() == IPv4.PROTOCOL_TCP) { log.warn("Driver automatically punts all packets reaching the " + "LOCAL table to the controller"); pass(fwd); return Collections.emptySet(); } } log.warn("Driver does not support given versatile forwarding objective"); fail(fwd, ObjectiveError.UNSUPPORTED); return Collections.emptySet(); } private Collection processSpecific(ForwardingObjective fwd) { log.debug("Processing specific forwarding objective"); TrafficSelector selector = fwd.selector(); EthTypeCriterion ethType = (EthTypeCriterion) selector.getCriterion(Criterion.Type.ETH_TYPE); if (ethType == null || ethType.ethType().toShort() != Ethernet.TYPE_IPV4) { fail(fwd, ObjectiveError.UNSUPPORTED); return Collections.emptySet(); } TrafficSelector filteredSelector = DefaultTrafficSelector.builder() .matchEthType(Ethernet.TYPE_IPV4) .matchIPDst( ((IPCriterion) selector.getCriterion(Criterion.Type.IPV4_DST)).ip()) .build(); TrafficTreatment.Builder tb = DefaultTrafficTreatment.builder(); if (fwd.nextId() != null) { NextGroup next = flowObjectiveStore.getNextGroup(fwd.nextId()); GroupKey key = appKryo.deserialize(next.data()); Group group = groupService.getGroup(deviceId, key); if (group == null) { log.warn("The group left!"); fail(fwd, ObjectiveError.GROUPMISSING); return Collections.emptySet(); } tb.group(group.id()); } FlowRule.Builder ruleBuilder = DefaultFlowRule.builder() .fromApp(fwd.appId()) .withPriority(fwd.priority()) .forDevice(deviceId) .withSelector(filteredSelector) .withTreatment(tb.build()); if (fwd.permanent()) { ruleBuilder.makePermanent(); } else { ruleBuilder.makeTemporary(fwd.timeout()); } ruleBuilder.forTable(FIB_TABLE); return Collections.singletonList(ruleBuilder.build()); } private void processFilter(FilteringObjective filt, boolean install, ApplicationId applicationId) { // This driver only processes filtering criteria defined with switch // ports as the key PortCriterion p; if (!filt.key().equals(Criteria.dummy()) && filt.key().type() == Criterion.Type.IN_PORT) { p = (PortCriterion) filt.key(); } else { log.warn("No key defined in filtering objective from app: {}. Not" + "processing filtering objective", applicationId); fail(filt, ObjectiveError.UNKNOWN); return; } // convert filtering conditions for switch-intfs into flowrules FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); for (Criterion c : filt.conditions()) { if (c.type() == Criterion.Type.ETH_DST) { EthCriterion e = (EthCriterion) c; log.debug("adding rule for MAC: {}", e.mac()); TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment.builder(); selector.matchEthDst(e.mac()); treatment.transition(VLAN_MPLS_TABLE); FlowRule rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(applicationId) .makePermanent() .forTable(MAC_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); } else if (c.type() == Criterion.Type.VLAN_VID) { VlanIdCriterion v = (VlanIdCriterion) c; log.debug("adding rule for VLAN: {}", v.vlanId()); TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment.builder(); selector.matchVlanId(v.vlanId()); selector.matchInPort(p.port()); treatment.transition(ETHER_TABLE); treatment.deferred().popVlan(); FlowRule rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(applicationId) .makePermanent() .forTable(VLAN_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); } else if (c.type() == Criterion.Type.IPV4_DST) { IPCriterion ip = (IPCriterion) c; log.debug("adding rule for IP: {}", ip.ip()); TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment.builder(); selector.matchEthType(Ethernet.TYPE_IPV4); selector.matchIPDst(ip.ip()); treatment.transition(LOCAL_TABLE); FlowRule rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(HIGHEST_PRIORITY) .fromApp(applicationId) .makePermanent() .forTable(FIB_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); } else { log.warn("Driver does not currently process filtering condition" + " of type: {}", c.type()); fail(filt, ObjectiveError.UNSUPPORTED); } } // apply filtering flow rules flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { pass(filt); log.info("Applied filtering rules"); } @Override public void onError(FlowRuleOperations ops) { fail(filt, ObjectiveError.FLOWINSTALLATIONFAILED); log.info("Failed to apply filtering rules"); } })); } private void pass(Objective obj) { if (obj.context().isPresent()) { obj.context().get().onSuccess(obj); } } private void fail(Objective obj, ObjectiveError error) { if (obj.context().isPresent()) { obj.context().get().onError(obj, error); } } private void initializePipeline() { processMacTable(true); processVlanMplsTable(true); processVlanTable(true); processEtherTable(true); processCosTable(true); processFibTable(true); processLocalTable(true); } private void processMacTable(boolean install) { TrafficSelector.Builder selector; TrafficTreatment.Builder treatment; // Bcast rule selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); selector.matchEthDst(MacAddress.BROADCAST); treatment.transition(VLAN_MPLS_TABLE); FlowRule rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(appId) .makePermanent() .forTable(MAC_TABLE).build(); FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); ops = install ? ops.add(rule) : ops.remove(rule); //Drop rule selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); treatment.drop(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(DROP_PRIORITY) .fromApp(appId) .makePermanent() .forTable(MAC_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned mac table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision mac table"); } })); } protected void processVlanMplsTable(boolean install) { TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment .builder(); FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; selector.matchVlanId(VlanId.ANY); treatment.transition(VLAN_TABLE); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(appId) .makePermanent() .forTable(VLAN_MPLS_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned vlan/mpls table"); } @Override public void onError(FlowRuleOperations ops) { log.info( "Failed to provision vlan/mpls table"); } })); } private void processVlanTable(boolean install) { TrafficSelector.Builder selector; TrafficTreatment.Builder treatment; FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; //Drop rule selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); treatment.drop(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(DROP_PRIORITY) .fromApp(appId) .makePermanent() .forTable(VLAN_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned vlan table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision vlan table"); } })); } private void processEtherTable(boolean install) { TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment .builder(); FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; selector.matchEthType(Ethernet.TYPE_ARP); treatment.punt(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(appId) .makePermanent() .forTable(ETHER_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); selector.matchEthType(Ethernet.TYPE_IPV4); treatment.transition(COS_MAP_TABLE); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withPriority(CONTROLLER_PRIORITY) .withSelector(selector.build()) .withTreatment(treatment.build()) .fromApp(appId) .makePermanent() .forTable(ETHER_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); //Drop rule selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); treatment.drop(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(DROP_PRIORITY) .fromApp(appId) .makePermanent() .forTable(ETHER_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned ether table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision ether table"); } })); } private void processCosTable(boolean install) { TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment .builder(); FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; treatment.transition(FIB_TABLE); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(DROP_PRIORITY) .fromApp(appId) .makePermanent() .forTable(COS_MAP_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned cos table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision cos table"); } })); } private void processFibTable(boolean install) { TrafficSelector.Builder selector; TrafficTreatment.Builder treatment; FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; //Drop rule selector = DefaultTrafficSelector.builder(); treatment = DefaultTrafficTreatment.builder(); treatment.drop(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(DROP_PRIORITY) .fromApp(appId) .makePermanent() .forTable(FIB_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned FIB table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision FIB table"); } })); } private void processLocalTable(boolean install) { TrafficSelector.Builder selector = DefaultTrafficSelector.builder(); TrafficTreatment.Builder treatment = DefaultTrafficTreatment .builder(); FlowRuleOperations.Builder ops = FlowRuleOperations.builder(); FlowRule rule; treatment.punt(); rule = DefaultFlowRule.builder() .forDevice(deviceId) .withSelector(selector.build()) .withTreatment(treatment.build()) .withPriority(CONTROLLER_PRIORITY) .fromApp(appId) .makePermanent() .forTable(LOCAL_TABLE).build(); ops = install ? ops.add(rule) : ops.remove(rule); flowRuleService.apply(ops.build(new FlowRuleOperationsContext() { @Override public void onSuccess(FlowRuleOperations ops) { log.info("Provisioned Local table"); } @Override public void onError(FlowRuleOperations ops) { log.info("Failed to provision Local table"); } })); } private class InnerGroupListener implements GroupListener { @Override public void event(GroupEvent event) { if (event.type() == GroupEvent.Type.GROUP_ADDED) { GroupKey key = event.subject().appCookie(); NextObjective obj = pendingGroups.getIfPresent(key); if (obj != null) { flowObjectiveStore.putNextGroup(obj.id(), new CorsaGroup(key)); pass(obj); pendingGroups.invalidate(key); } } } } private class GroupChecker implements Runnable { @Override public void run() { Set keys = pendingGroups.asMap().keySet().stream() .filter(key -> groupService.getGroup(deviceId, key) != null) .collect(Collectors.toSet()); keys.stream().forEach(key -> { NextObjective obj = pendingGroups.getIfPresent(key); if (obj == null) { return; } pass(obj); pendingGroups.invalidate(key); log.info("Heard back from group service for group {}. " + "Applying pending forwarding objectives", obj.id()); flowObjectiveStore.putNextGroup(obj.id(), new CorsaGroup(key)); }); } } private class CorsaGroup implements NextGroup { private final GroupKey key; public CorsaGroup(GroupKey key) { this.key = key; } @SuppressWarnings("unused") public GroupKey key() { return key; } @Override public byte[] data() { return appKryo.serialize(key); } } }