DHCP Relay Application, addressed the review comments for patch-2.

Change-Id: If447f3786c661c667460f43fc659ea71dd198be7

@@ -98,6 +98,7 @@ APPS = [
 
     # Apps
     '//apps/dhcp:onos-apps-dhcp-oar',
+    '//apps/dhcprelay:onos-apps-dhcprelay-oar',
     '//apps/fwd:onos-apps-fwd-oar',
     '//apps/acl:onos-apps-acl-oar',
     '//apps/bgprouter:onos-apps-bgprouter-oar',
@@ -147,6 +148,7 @@ APP_JARS = [
     '//apps/routing-api:onos-apps-routing-api',
     '//apps/dhcp/api:onos-apps-dhcp-api',
     '//apps/dhcp/app:onos-apps-dhcp-app',
+    '//apps/dhcprelay:onos-apps-dhcprelay',
     '//apps/fwd:onos-apps-fwd',
     '//apps/iptopology-api:onos-apps-iptopology-api',
     '//apps/openstacknode:onos-apps-openstacknode',

+COMPILE_DEPS = [
+    '//lib:CORE_DEPS',
+]
+
+osgi_jar (
+    deps = COMPILE_DEPS,
+)
+
+onos_app (
+    app_name = 'org.onosproject.dhcprelay',
+    title = 'DHCP Relay Agent App',
+    category = 'default',
+    url = 'http://onosproject.org',
+    description = 'DHCP Relay Agent Application.',
+)

+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2016 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.
+  -->
+<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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-apps</artifactId>
+        <version>1.7.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-dhcprelay</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>DHCP Relay Agent</description>
+    <url>http://onosproject.org</url>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <onos.version>1.6.0-SNAPSHOT</onos.version>
+        <onos.app.name>org.onosproject.dhcprelay</onos.app.name>
+        <onos.app.title>DHCP Relay Agent App</onos.app.title>
+        <onos.app.origin>ON.Lab</onos.app.origin>
+        <onos.app.category>default</onos.app.category>
+        <onos.app.url>http://onosproject.org</onos.app.url>
+        <onos.app.readme>DHCP Relay Agent Application.</onos.app.readme>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+            <version>${onos.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onlab-osgi</artifactId>
+            <version>${onos.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+ 
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onlab-junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+            <version>${onos.version}</version>
+            <scope>test</scope>
+            <classifier>tests</classifier>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+            <version>1.9.12</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+</project>

+/*
+ * Copyright 2016-present 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.dhcprelay;
+
+import java.util.Set;
+
+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.DHCP;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IPv4;
+import org.onlab.packet.TpPort;
+import org.onlab.packet.UDP;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.Host;
+import org.onosproject.net.HostId;
+import org.onosproject.net.config.ConfigFactory;
+import org.onosproject.net.config.NetworkConfigEvent;
+import org.onosproject.net.config.NetworkConfigListener;
+import org.onosproject.net.config.NetworkConfigRegistry;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.host.HostService;
+import org.onosproject.net.packet.DefaultOutboundPacket;
+import org.onosproject.net.packet.OutboundPacket;
+import org.onosproject.net.packet.PacketContext;
+import org.onosproject.net.packet.PacketPriority;
+import org.onosproject.net.packet.PacketProcessor;
+import org.onosproject.net.packet.PacketService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.ImmutableSet;
+import static org.onosproject.net.config.basics.SubjectFactories.APP_SUBJECT_FACTORY;
+/**
+ * DHCP Relay Agent Application Component.
+ */
+@Component(immediate = true)
+public class DhcpRelay {
+
+    public static final String DHCP_RELAY_APP = "org.onosproject.dhcp-relay";
+    private final Logger log = LoggerFactory.getLogger(getClass());
+    private final InternalConfigListener cfgListener = new InternalConfigListener();
+
+    private final Set<ConfigFactory> factories = ImmutableSet.of(
+            new ConfigFactory<ApplicationId, DhcpRelayConfig>(APP_SUBJECT_FACTORY,
+                    DhcpRelayConfig.class,
+                    "dhcprelay") {
+                @Override
+                public DhcpRelayConfig createConfig() {
+                    return new DhcpRelayConfig();
+                }
+            }
+    );
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected NetworkConfigRegistry cfgService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostService hostService;
+
+    private DhcpRelayPacketProcessor dhcpRelayPacketProcessor = new DhcpRelayPacketProcessor();
+    private ConnectPoint dhcpServerConnectPoint = null;
+    private ApplicationId appId;
+
+    @Activate
+    protected void activate() {
+        //start the dhcp relay agent
+
+        appId = coreService.registerApplication(DHCP_RELAY_APP);
+
+        cfgService.addListener(cfgListener);
+        factories.forEach(cfgService::registerConfigFactory);
+        //update the dhcp server configuration.
+        updateConfig();
+        //add the packet services.
+        packetService.addProcessor(dhcpRelayPacketProcessor, PacketProcessor.director(0));
+        requestPackets();
+        log.info("DHCP-RELAY Started");
+        log.info("started the apps dhcp relay");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        cfgService.removeListener(cfgListener);
+        factories.forEach(cfgService::unregisterConfigFactory);
+        packetService.removeProcessor(dhcpRelayPacketProcessor);
+        cancelPackets();
+        log.info("DHCP-RELAY Stopped");
+    }
+
+    private void updateConfig() {
+        DhcpRelayConfig cfg = cfgService.getConfig(appId, DhcpRelayConfig.class);
+
+        if (cfg == null) {
+            log.warn("Dhcp Server info not available");
+            return;
+        }
+
+        dhcpServerConnectPoint = cfg.getDhcpServerConnectPoint();
+        log.info("Reconfigured the dhcp server info");
+        log.info("dhcp server connect points are " + dhcpServerConnectPoint);
+    }
+
+    /**
+     * Request packet in via PacketService.
+     */
+    private void requestPackets() {
+
+        TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpDst(TpPort.tpPort(UDP.DHCP_SERVER_PORT))
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
+        packetService.requestPackets(selectorServer.build(), PacketPriority.CONTROL, appId);
+
+        TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpDst(TpPort.tpPort(UDP.DHCP_CLIENT_PORT))
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
+        packetService.requestPackets(selectorClient.build(), PacketPriority.CONTROL, appId);
+    }
+
+    /**
+     * Cancel requested packets in via packet service.
+     */
+    private void cancelPackets() {
+        TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpDst(TpPort.tpPort(UDP.DHCP_SERVER_PORT))
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
+        packetService.cancelPackets(selectorServer.build(), PacketPriority.CONTROL, appId);
+
+        TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpDst(TpPort.tpPort(UDP.DHCP_CLIENT_PORT))
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
+        packetService.cancelPackets(selectorClient.build(), PacketPriority.CONTROL, appId);
+    }
+
+    private class DhcpRelayPacketProcessor implements PacketProcessor {
+
+        @Override
+        public void process(PacketContext context) {
+            // process the packet and get the payload
+            Ethernet packet = context.inPacket().parsed();
+
+            if (packet == null) {
+                return;
+            }
+
+            if (packet.getEtherType() == Ethernet.TYPE_IPV4) {
+                IPv4 ipv4Packet = (IPv4) packet.getPayload();
+
+                if (ipv4Packet.getProtocol() == IPv4.PROTOCOL_UDP) {
+                    UDP udpPacket = (UDP) ipv4Packet.getPayload();
+                    DHCP dhcpPayload = (DHCP) udpPacket.getPayload();
+                    if (udpPacket.getDestinationPort() == UDP.DHCP_SERVER_PORT &&
+                        udpPacket.getSourcePort() == UDP.DHCP_CLIENT_PORT) {
+                        //This packet is dhcp client request.
+                        forwardPacket(context, dhcpPayload);
+                    } else {
+                        //This packet is a dhcp reply from DHCP server.
+                        sendReply(context, dhcpPayload);
+                    }
+                }
+            }
+        }
+
+        //forward the packet to ConnectPoint where the DHCP server is attached.
+        private void forwardPacket(PacketContext context, DHCP dhcpPayload) {
+            if (dhcpPayload == null) {
+                log.debug("DHCP packet without payload, do nothing");
+                return;
+            }
+
+            //send Packetout to dhcp server connectpoint.
+            if (dhcpServerConnectPoint != null) {
+                TrafficTreatment t = DefaultTrafficTreatment.builder()
+                        .setOutput(dhcpServerConnectPoint.port()).build();
+                OutboundPacket o = new DefaultOutboundPacket(
+                        dhcpServerConnectPoint.deviceId(), t, context.inPacket().unparsed());
+                packetService.emit(o);
+            }
+        }
+
+        /*//process the dhcp packet before sending to server
+        private void processDhcpPacket(PacketContext context, DHCP dhcpPayload) {
+            if (dhcpPayload == null) {
+                return;
+            }
+            Ethernet packet = context.inPacket().parsed();
+            DHCPPacketType incomingPacketType = null;
+            for (DHCPOption option : dhcpPayload.getOptions()) {
+                if (option.getCode() == OptionCode_MessageType.getValue()) {
+                    byte[] data = option.getData();
+                    incomingPacketType = DHCPPacketType.getType(data[0]);
+                }
+            }
+            switch (incomingPacketType) {
+            case DHCPDISCOVER:
+                break;
+            default:
+                break;
+            }
+        }*/
+
+        //send the response to the requestor host.
+        private void sendReply(PacketContext context, DHCP dhcpPayload) {
+            if (dhcpPayload == null) {
+                log.debug("DHCP packet without payload, do nothing");
+                return;
+            }
+            //get the host info
+            Ethernet packet = context.inPacket().parsed();
+            Host host = hostService.getHost(HostId.hostId(packet.getDestinationMAC()));
+            ConnectPoint dhcpRequestor = new ConnectPoint(host.location().elementId(),
+                                                    host.location().port());
+
+            //send Packetout to requestor host.
+            if (dhcpRequestor != null) {
+                TrafficTreatment t = DefaultTrafficTreatment.builder()
+                        .setOutput(dhcpRequestor.port()).build();
+                OutboundPacket o = new DefaultOutboundPacket(
+                        dhcpRequestor.deviceId(), t, context.inPacket().unparsed());
+                packetService.emit(o);
+            }
+        }
+    }
+
+    /**
+     * Listener for network config events.
+     */
+    private class InternalConfigListener implements NetworkConfigListener {
+
+        @Override
+        public void event(NetworkConfigEvent event) {
+
+            if ((event.type() == NetworkConfigEvent.Type.CONFIG_ADDED ||
+                    event.type() == NetworkConfigEvent.Type.CONFIG_UPDATED) &&
+                    event.configClass().equals(DhcpRelayConfig.class)) {
+                updateConfig();
+                log.info("Reconfigured");
+            }
+        }
+    }
+}

+/*
+ * Copyright 2016-present 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.dhcprelay;
+
+import org.onosproject.core.ApplicationId;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.config.Config;
+
+import static org.onosproject.net.config.Config.FieldPresence.MANDATORY;
+/**
+ * DHCP Relay Config class.
+ */
+public class DhcpRelayConfig extends Config<ApplicationId> {
+
+    private static final String DHCP_CONNECT_POINT = "dhcpserverConnectPoint";
+
+    @Override
+    public boolean isValid() {
+
+        return hasOnlyFields(DHCP_CONNECT_POINT) &&
+                isConnectPoint(DHCP_CONNECT_POINT, MANDATORY);
+    }
+
+    /**
+     * Returns the dhcp server connect point.
+     *
+     * @return dhcp server connect point
+     */
+    public ConnectPoint getDhcpServerConnectPoint() {
+        return ConnectPoint.deviceConnectPoint(object.path(DHCP_CONNECT_POINT).asText());
+    }
+}

+/*
+ * Copyright 2014-present 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.
+ */
+
+/**
+ *  DHCP-RELAY application.
+ */
+package org.onosproject.dhcprelay;

+{
+  "apps": {
+    "org.onosproject.dhcp-relay" : {
+      "dhcprelay" : {
+        "dhcpserverConnectPoint": "of:0000000000000002/2"
+      }
+    }
+  }
+}

@@ -53,6 +53,7 @@
         <module>flowanalyzer</module>
         <module>vtn</module>
         <module>dhcp</module>
+        <module>dhcprelay</module>
         <module>mfwd</module>
         <module>pim</module>
         <module>mlb</module>