FPM component that can decode routes from Quagga's FIB push interface.

Change-Id: I57bfd9273b81c8d368a59a3acea53486cb4acfc1
diff --git a/apps/routing/src/main/java/org/onosproject/routing/fpm/FpmManager.java b/apps/routing/src/main/java/org/onosproject/routing/fpm/FpmManager.java
new file mode 100644
index 0000000..d89ae4e
--- /dev/null
+++ b/apps/routing/src/main/java/org/onosproject/routing/fpm/FpmManager.java
@@ -0,0 +1,213 @@
+/*
+ * 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.
+ */
+package org.onosproject.routing.fpm;
+
+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.Service;
+import org.jboss.netty.bootstrap.ServerBootstrap;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelException;
+import org.jboss.netty.channel.ChannelFactory;
+import org.jboss.netty.channel.ChannelPipeline;
+import org.jboss.netty.channel.ChannelPipelineFactory;
+import org.jboss.netty.channel.Channels;
+import org.jboss.netty.channel.group.ChannelGroup;
+import org.jboss.netty.channel.group.DefaultChannelGroup;
+import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onosproject.routing.RouteEntry;
+import org.onosproject.routing.RouteListener;
+import org.onosproject.routing.RouteSourceService;
+import org.onosproject.routing.RouteUpdate;
+import org.onosproject.routing.fpm.protocol.FpmHeader;
+import org.onosproject.routing.fpm.protocol.Netlink;
+import org.onosproject.routing.fpm.protocol.RouteAttribute;
+import org.onosproject.routing.fpm.protocol.RouteAttributeDst;
+import org.onosproject.routing.fpm.protocol.RouteAttributeGateway;
+import org.onosproject.routing.fpm.protocol.RtNetlink;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.InetSocketAddress;
+import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static java.util.concurrent.Executors.newCachedThreadPool;
+import static org.onlab.util.Tools.groupedThreads;
+
+/**
+ * Forwarding Plane Manager (FPM) route source.
+ */
+@Service
+@Component(immediate = true, enabled = false)
+public class FpmManager implements RouteSourceService {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private ServerBootstrap serverBootstrap;
+    private Channel serverChannel;
+    private ChannelGroup allChannels = new DefaultChannelGroup();
+
+    private Map<IpPrefix, RouteEntry> fpmRoutes = new ConcurrentHashMap<>();
+
+    private RouteListener routeListener;
+
+    private static final int FPM_PORT = 2620;
+
+    @Activate
+    protected void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        stopServer();
+        log.info("Stopped");
+    }
+
+    private void startServer() {
+        ChannelFactory channelFactory = new NioServerSocketChannelFactory(
+                newCachedThreadPool(groupedThreads("onos/fpm", "sm-boss-%d")),
+                newCachedThreadPool(groupedThreads("onos/fpm", "sm-worker-%d")));
+        ChannelPipelineFactory pipelineFactory = () -> {
+            // Allocate a new session per connection
+            FpmSessionHandler fpmSessionHandler =
+                    new FpmSessionHandler(new InternalFpmListener());
+            FpmFrameDecoder fpmFrameDecoder =
+                    new FpmFrameDecoder();
+
+            // Setup the processing pipeline
+            ChannelPipeline pipeline = Channels.pipeline();
+            pipeline.addLast("FpmFrameDecoder", fpmFrameDecoder);
+            pipeline.addLast("FpmSession", fpmSessionHandler);
+            return pipeline;
+        };
+
+        InetSocketAddress listenAddress = new InetSocketAddress(FPM_PORT);
+
+        serverBootstrap = new ServerBootstrap(channelFactory);
+        serverBootstrap.setOption("child.reuseAddr", true);
+        serverBootstrap.setOption("child.keepAlive", true);
+        serverBootstrap.setOption("child.tcpNoDelay", true);
+        serverBootstrap.setPipelineFactory(pipelineFactory);
+        try {
+            serverChannel = serverBootstrap.bind(listenAddress);
+            allChannels.add(serverChannel);
+        } catch (ChannelException e) {
+            log.debug("Exception binding to FPM port {}: ",
+                    listenAddress.getPort(), e);
+            stopServer();
+        }
+    }
+
+    private void stopServer() {
+        allChannels.close().awaitUninterruptibly();
+        allChannels.clear();
+        if (serverBootstrap != null) {
+            serverBootstrap.releaseExternalResources();
+        }
+    }
+
+    @Override
+    public void start(RouteListener routeListener) {
+        this.routeListener = routeListener;
+
+        startServer();
+    }
+
+    @Override
+    public void stop() {
+        fpmRoutes.clear();
+        stopServer();
+    }
+
+    private void fpmMessage(FpmHeader fpmMessage) {
+        Netlink netlink = fpmMessage.netlink();
+        RtNetlink rtNetlink = netlink.rtNetlink();
+
+        if (log.isTraceEnabled()) {
+            log.trace("Received FPM message: {}", fpmMessage);
+        }
+
+        IpAddress dstAddress = null;
+        IpAddress gateway = null;
+
+        for (RouteAttribute attribute : rtNetlink.attributes()) {
+            if (attribute.type() == RouteAttribute.RTA_DST) {
+                RouteAttributeDst raDst = (RouteAttributeDst) attribute;
+                dstAddress = raDst.dstAddress();
+            } else if (attribute.type() == RouteAttribute.RTA_GATEWAY) {
+                RouteAttributeGateway raGateway = (RouteAttributeGateway) attribute;
+                gateway = raGateway.gateway();
+            }
+        }
+
+        if (dstAddress == null) {
+            log.error("Dst address missing!");
+            return;
+        }
+
+        IpPrefix prefix = IpPrefix.valueOf(dstAddress, rtNetlink.dstLength());
+
+        RouteUpdate routeUpdate = null;
+        RouteEntry entry;
+        switch (netlink.type()) {
+        case RTM_NEWROUTE:
+            if (gateway == null) {
+                // We ignore interface routes with no gateway for now.
+                return;
+            }
+            entry = new RouteEntry(prefix, gateway);
+
+            fpmRoutes.put(entry.prefix(), entry);
+
+            routeUpdate = new RouteUpdate(RouteUpdate.Type.UPDATE, entry);
+            break;
+        case RTM_DELROUTE:
+            RouteEntry existing = fpmRoutes.remove(prefix);
+            if (existing == null) {
+                log.warn("Got delete for non-existent prefix");
+                return;
+            }
+
+            entry = new RouteEntry(prefix, existing.nextHop());
+
+            routeUpdate = new RouteUpdate(RouteUpdate.Type.DELETE, entry);
+            break;
+        case RTM_GETROUTE:
+        default:
+            break;
+        }
+
+        if (routeUpdate == null) {
+            log.warn("Unsupported FPM message: {}", fpmMessage);
+            return;
+        }
+
+        routeListener.update(Collections.singletonList(routeUpdate));
+    }
+
+    private class InternalFpmListener implements FpmMessageListener {
+        @Override
+        public void fpmMessage(FpmHeader fpmMessage) {
+            FpmManager.this.fpmMessage(fpmMessage);
+        }
+    }
+
+}