MyTunnel exercise with solution for P4 tutorial
Change-Id: Ifddfa27d6df6545bbd529239ca400967fb623a29
diff --git a/apps/p4-tutorial/mytunnel/src/main/java/org/onosproject/p4tutorial/mytunnel/MyTunnelApp.solution b/apps/p4-tutorial/mytunnel/src/main/java/org/onosproject/p4tutorial/mytunnel/MyTunnelApp.solution
new file mode 100644
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+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.p4tutorial.mytunnel;
+
+import com.google.common.collect.Lists;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.packet.IpAddress;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.Host;
+import org.onosproject.net.Link;
+import org.onosproject.net.Path;
+import org.onosproject.net.PortNumber;
+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.FlowRuleService;
+import org.onosproject.net.flow.criteria.PiCriterion;
+import org.onosproject.net.host.HostEvent;
+import org.onosproject.net.host.HostListener;
+import org.onosproject.net.host.HostService;
+import org.onosproject.net.pi.model.PiActionId;
+import org.onosproject.net.pi.model.PiActionParamId;
+import org.onosproject.net.pi.model.PiMatchFieldId;
+import org.onosproject.net.pi.model.PiTableId;
+import org.onosproject.net.pi.runtime.PiAction;
+import org.onosproject.net.pi.runtime.PiActionParam;
+import org.onosproject.net.topology.Topology;
+import org.onosproject.net.topology.TopologyService;
+import org.slf4j.Logger;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * MyTunnel application which provides forwarding between each pair of hosts via
+ * MyTunnel protocol as defined in mytunnel.p4.
+ * <p>
+ * The app works by listening for host events. Each time a new host is
+ * discovered, it provisions a tunnel between that host and all the others.
+ */
+@Component(immediate = true)
+public class MyTunnelApp {
+
+ private static final String APP_NAME = "org.onosproject.p4tutorial.mytunnel";
+
+ // Default priority used for flow rules installed by this app.
+ private static final int FLOW_RULE_PRIORITY = 100;
+
+ private final HostListener hostListener = new InternalHostListener();
+ private ApplicationId appId;
+ private AtomicInteger nextTunnelId = new AtomicInteger();
+
+ private static final Logger log = getLogger(MyTunnelApp.class);
+
+ //--------------------------------------------------------------------------
+ // ONOS services needed by this application.
+ //--------------------------------------------------------------------------
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ private FlowRuleService flowRuleService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ private CoreService coreService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ private TopologyService topologyService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ private HostService hostService;
+
+ //--------------------------------------------------------------------------
+ //--------------------------------------------------------------------------
+
+ @Activate
+ public void activate() {
+ // Register app and event listeners.
+ log.info("Starting...");
+ appId = coreService.registerApplication(APP_NAME);
+ hostService.addListener(hostListener);
+ log.info("STARTED", appId.id());
+ }
+
+ @Deactivate
+ public void deactivate() {
+ // Remove listeners and clean-up flow rules.
+ log.info("Stopping...");
+ hostService.removeListener(hostListener);
+ flowRuleService.removeFlowRulesById(appId);
+ log.info("STOPPED");
+ }
+
+ /**
+ * Provisions a tunnel between the given source and destination host with
+ * the given tunnel ID. The tunnel is established using a randomly picked
+ * shortest path based on the given topology snapshot.
+ *
+ * @param tunId tunnel ID
+ * @param srcHost tunnel source host
+ * @param dstHost tunnel destination host
+ * @param topo topology snapshot
+ */
+ private void provisionTunnel(int tunId, Host srcHost, Host dstHost, Topology topo) {
+
+ // Get all shortest paths between switches connected to source and
+ // destination hosts.
+ DeviceId srcSwitch = srcHost.location().deviceId();
+ DeviceId dstSwitch = dstHost.location().deviceId();
+
+ List<Link> pathLinks;
+ if (srcSwitch.equals(dstSwitch)) {
+ // Source and dest hosts are connected to the same switch.
+ pathLinks = Collections.emptyList();
+ } else {
+ // Compute shortest path.
+ Set<Path> allPaths = topologyService.getPaths(topo, srcSwitch, dstSwitch);
+ if (allPaths.size() == 0) {
+ log.warn("No paths between {} and {}", srcHost.id(), dstHost.id());
+ return;
+ }
+ // If many shortest paths are available, pick a random one.
+ pathLinks = pickRandomPath(allPaths).links();
+ }
+
+ // Tunnel ingress rules.
+ for (IpAddress dstIpAddr : dstHost.ipAddresses()) {
+ // In ONOS discovered hosts can have multiple IP addresses.
+ // Insert tunnel ingress rule for each IP address.
+ // Next switches will forward based only on tunnel ID.
+ insertTunnelIngressRule(srcSwitch, dstIpAddr, tunId);
+ }
+
+ // Insert tunnel transit rules on all switches in the path, excluded the
+ // last one.
+ for (Link link : pathLinks) {
+ DeviceId sw = link.src().deviceId();
+ PortNumber port = link.src().port();
+ insertTunnelForwardRule(sw, port, tunId, false);
+ }
+
+ // Tunnel egress rule.
+ PortNumber egressSwitchPort = dstHost.location().port();
+ insertTunnelForwardRule(dstSwitch, egressSwitchPort, tunId, true);
+
+ log.info("** Completed provisioning of tunnel {} (srcHost={} dstHost={})",
+ tunId, srcHost.id(), dstHost.id());
+ }
+
+ /**
+ * Generates and insert a flow rule to perform the tunnel INGRESS function
+ * for the given switch, destination IP address and tunnel ID.
+ *
+ * @param switchId switch ID
+ * @param dstIpAddr IP address to forward inside the tunnel
+ * @param tunId tunnel ID
+ */
+ private void insertTunnelIngressRule(DeviceId switchId,
+ IpAddress dstIpAddr,
+ int tunId) {
+
+
+ PiTableId tunnelIngressTableId = PiTableId.of("c_ingress.t_tunnel_ingress");
+
+ // Longest prefix match on IPv4 dest address.
+ PiMatchFieldId ipDestMatchFieldId = PiMatchFieldId.of("hdr.ipv4.dst_addr");
+ PiCriterion match = PiCriterion.builder()
+ .matchLpm(ipDestMatchFieldId, dstIpAddr.toOctets(), 32)
+ .build();
+
+ PiActionParam tunIdParam = new PiActionParam(PiActionParamId.of("tun_id"), tunId);
+
+ PiActionId ingressActionId = PiActionId.of("c_ingress.my_tunnel_ingress");
+ PiAction action = PiAction.builder()
+ .withId(ingressActionId)
+ .withParameter(tunIdParam)
+ .build();
+
+ log.info("Inserting INGRESS rule on switch {}: table={}, match={}, action={}",
+ switchId, tunnelIngressTableId, match, action);
+
+ insertPiFlowRule(switchId, tunnelIngressTableId, match, action);
+ }
+
+ /**
+ * Generates and insert a flow rule to perform the tunnel FORWARD/EGRESS
+ * function for the given switch, output port address and tunnel ID.
+ *
+ * @param switchId switch ID
+ * @param outPort output port where to forward tunneled packets
+ * @param tunId tunnel ID
+ * @param isEgress if true, perform tunnel egress action, otherwise forward
+ * packet as is to port
+ */
+ private void insertTunnelForwardRule(DeviceId switchId,
+ PortNumber outPort,
+ int tunId,
+ boolean isEgress) {
+
+ PiTableId tunnelForwardTableId = PiTableId.of("c_ingress.t_tunnel_fwd");
+
+ // Exact match on tun_id
+ PiMatchFieldId tunIdMatchFieldId = PiMatchFieldId.of("hdr.my_tunnel.tun_id");
+ PiCriterion match = PiCriterion.builder()
+ .matchExact(tunIdMatchFieldId, tunId)
+ .build();
+
+ // Action depend on isEgress parameter.
+ // if true, perform tunnel egress action on the given outPort, otherwise
+ // simply forward packet as is (set_out_port action).
+ PiActionParamId portParamId = PiActionParamId.of("port");
+ PiActionParam portParam = new PiActionParam(portParamId, (short) outPort.toLong());
+
+ final PiAction action;
+ if (isEgress) {
+ // Tunnel egress action.
+ // Remove MyTunnel header and forward to outPort.
+ PiActionId egressActionId = PiActionId.of("c_ingress.my_tunnel_egress");
+ action = PiAction.builder()
+ .withId(egressActionId)
+ .withParameter(portParam)
+ .build();
+ } else {
+ // Tunnel transit action.
+ // Forward the packet as is to outPort.
+ PiActionId egressActionId = PiActionId.of("c_ingress.set_out_port");
+ action = PiAction.builder()
+ .withId(egressActionId)
+ .withParameter(portParam)
+ .build();
+ }
+
+ log.info("Inserting {} rule on switch {}: table={}, match={}, action={}",
+ isEgress ? "EGRESS" : "TRANSIT",
+ switchId, tunnelForwardTableId, match, action);
+
+ insertPiFlowRule(switchId, tunnelForwardTableId, match, action);
+ }
+
+ /**
+ * Inserts a flow rule in the system that using a PI criterion and action.
+ *
+ * @param switchId switch ID
+ * @param tableId table ID
+ * @param piCriterion PI criterion
+ * @param piAction PI action
+ */
+ private void insertPiFlowRule(DeviceId switchId, PiTableId tableId,
+ PiCriterion piCriterion, PiAction piAction) {
+ FlowRule rule = DefaultFlowRule.builder()
+ .forDevice(switchId)
+ .forTable(tableId)
+ .fromApp(appId)
+ .withPriority(FLOW_RULE_PRIORITY)
+ .makePermanent()
+ .withSelector(DefaultTrafficSelector.builder()
+ .matchPi(piCriterion).build())
+ .withTreatment(DefaultTrafficTreatment.builder()
+ .piTableAction(piAction).build())
+ .build();
+ flowRuleService.applyFlowRules(rule);
+ }
+
+ private int getNewTunnelId() {
+ return nextTunnelId.incrementAndGet();
+ }
+
+ private Path pickRandomPath(Set<Path> paths) {
+ int item = new Random().nextInt(paths.size());
+ List<Path> pathList = Lists.newArrayList(paths);
+ return pathList.get(item);
+ }
+
+ /**
+ * A listener of host events that provisions two tunnels for each pair of
+ * hosts when a new host is discovered.
+ */
+ private class InternalHostListener implements HostListener {
+
+ @Override
+ public void event(HostEvent event) {
+ if (event.type() != HostEvent.Type.HOST_ADDED) {
+ // Ignore other host events.
+ return;
+ }
+ synchronized (this) {
+ // Synchronizing here is an overkill, but safer for demo purposes.
+ Host host = event.subject();
+ Topology topo = topologyService.currentTopology();
+ for (Host otherHost : hostService.getHosts()) {
+ if (!host.equals(otherHost)) {
+ provisionTunnel(getNewTunnelId(), host, otherHost, topo);
+ provisionTunnel(getNewTunnelId(), otherHost, host, topo);
+ }
+ }
+ }
+ }
+ }
+}