Added bi-directional nature to HostToHost intent.

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-apps</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-ifwd</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS simple reactive forwarding app that uses intent service</description>
+
+</project>

+package org.onlab.onos.ifwd;
+
+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.onos.ApplicationId;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.HostToHostIntent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.packet.InboundPacket;
+import org.onlab.onos.net.packet.PacketContext;
+import org.onlab.onos.net.packet.PacketProcessor;
+import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.topology.TopologyService;
+import org.onlab.packet.Ethernet;
+import org.slf4j.Logger;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * WORK-IN-PROGRESS: Sample reactive forwarding application using intent framework.
+ */
+@Component(immediate = true)
+public class IntentReactiveForwarding {
+
+    private static final int TIMEOUT = 10;
+    private static final int PRIORITY = 10;
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected TopologyService topologyService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentService intentService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostService hostService;
+
+    private ReactivePacketProcessor processor = new ReactivePacketProcessor();
+
+    private ApplicationId appId;
+    private static long intentId = 1;
+
+    @Activate
+    public void activate() {
+        appId = ApplicationId.getAppId();
+        packetService.addProcessor(processor, PacketProcessor.ADVISOR_MAX + 2);
+        log.info("Started with Application ID {}", appId.id());
+    }
+
+    @Deactivate
+    public void deactivate() {
+        packetService.removeProcessor(processor);
+        processor = null;
+        log.info("Stopped");
+    }
+
+
+    /**
+     * Packet processor responsible for forwarding packets along their paths.
+     */
+    private class ReactivePacketProcessor implements PacketProcessor {
+
+        @Override
+        public void process(PacketContext context) {
+            // Stop processing if the packet has been handled, since we
+            // can't do any more to it.
+            if (context.isHandled()) {
+                return;
+            }
+
+            InboundPacket pkt = context.inPacket();
+            Ethernet ethPkt = pkt.parsed();
+
+            HostId srcId = HostId.hostId(ethPkt.getSourceMAC());
+            HostId dstId = HostId.hostId(ethPkt.getDestinationMAC());
+
+            // Do we know who this is for? If not, flood and bail.
+            Host dst = hostService.getHost(dstId);
+            if (dst == null) {
+                flood(context);
+                return;
+            }
+
+            // Otherwise forward and be done with it.
+            setUpConnectivity(context, srcId, dstId);
+        }
+    }
+
+    // Floods the specified packet if permissible.
+    private void flood(PacketContext context) {
+        if (topologyService.isBroadcastPoint(topologyService.currentTopology(),
+                                             context.inPacket().receivedFrom())) {
+            packetOut(context, PortNumber.FLOOD);
+        } else {
+            context.block();
+        }
+    }
+
+    // Sends a packet out the specified port.
+    private void packetOut(PacketContext context, PortNumber portNumber) {
+        context.treatmentBuilder().setOutput(portNumber);
+        context.send();
+    }
+
+    // Install a rule forwarding the packet to the specified port.
+    private void setUpConnectivity(PacketContext context, HostId srcId, HostId dstId) {
+        TrafficSelector selector = DefaultTrafficSelector.builder().build();
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+
+        HostToHostIntent intent =
+                new HostToHostIntent(new IntentId(intentId++), srcId, dstId,
+                                     selector, treatment);
+
+        intentService.submit(intent);
+    }
+
+}
+
+

+/**
+ * Trivial application that provides simple form of reactive forwarding
+ * using the intent service.
+ */
+package org.onlab.onos.fwd;

@@ -19,6 +19,7 @@
     <modules>
         <module>tvue</module>
         <module>fwd</module>
+        <module>ifwd</module>
         <module>foo</module>
         <module>mobility</module>
         <module>proxyarp</module>

@@ -120,6 +120,12 @@
         <bundle>mvn:org.onlab.onos/onos-app-fwd/1.0.0-SNAPSHOT</bundle>
     </feature>
 
+    <feature name="onos-app-ifwd" version="1.0.0"
+             description="ONOS sample forwarding application using intents">
+        <feature>onos-api</feature>
+        <bundle>mvn:org.onlab.onos/onos-app-ifwd/1.0.0-SNAPSHOT</bundle>
+    </feature>
+
     <feature name="onos-app-mobility" version="1.0.0"
              description="ONOS sample mobility application">
         <feature>onos-api</feature>
@@ -132,8 +138,6 @@
         <bundle>mvn:org.onlab.onos/onos-app-proxyarp/1.0.0-SNAPSHOT</bundle>
     </feature>
 
-
-
     <feature name="onos-app-foo" version="1.0.0"
              description="ONOS sample playground application">
         <feature>onos-api</feature>