| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.onlab.onos.sdnip.bgp; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.net.InetAddress; |
| import java.net.InetSocketAddress; |
| import java.net.SocketAddress; |
| import java.util.Collection; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.Executors; |
| |
| 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.socket.nio.NioServerSocketChannelFactory; |
| import org.onlab.onos.sdnip.RouteListener; |
| import org.onlab.onos.sdnip.RouteUpdate; |
| import org.onlab.packet.IpAddress; |
| import org.onlab.packet.IpPrefix; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * BGP Session Manager class. |
| */ |
| public class BgpSessionManager { |
| private static final Logger log = |
| LoggerFactory.getLogger(BgpSessionManager.class); |
| private Channel serverChannel; // Listener for incoming BGP connections |
| private ConcurrentMap<SocketAddress, BgpSession> bgpSessions = |
| new ConcurrentHashMap<>(); |
| private IpAddress myBgpId; // Same BGP ID for all peers |
| |
| private BgpRouteSelector bgpRouteSelector = new BgpRouteSelector(); |
| private ConcurrentMap<IpPrefix, BgpRouteEntry> bgpRoutes = |
| new ConcurrentHashMap<>(); |
| |
| private final RouteListener routeListener; |
| |
| /** |
| * Constructor for given route listener. |
| * |
| * @param routeListener the route listener to use |
| */ |
| public BgpSessionManager(RouteListener routeListener) { |
| this.routeListener = checkNotNull(routeListener); |
| } |
| |
| /** |
| * Gets the BGP sessions. |
| * |
| * @return the BGP sessions |
| */ |
| public Collection<BgpSession> getBgpSessions() { |
| return bgpSessions.values(); |
| } |
| |
| /** |
| * Gets the BGP routes. |
| * |
| * @return the BGP routes |
| */ |
| public Collection<BgpRouteEntry> getBgpRoutes() { |
| return bgpRoutes.values(); |
| } |
| |
| /** |
| * Processes the connection from a BGP peer. |
| * |
| * @param bgpSession the BGP session for the peer |
| * @return true if the connection can be established, otherwise false |
| */ |
| boolean peerConnected(BgpSession bgpSession) { |
| |
| // Test whether there is already a session from the same remote |
| if (bgpSessions.get(bgpSession.getRemoteAddress()) != null) { |
| return false; // Duplicate BGP session |
| } |
| bgpSessions.put(bgpSession.getRemoteAddress(), bgpSession); |
| |
| // |
| // If the first connection, set my BGP ID to the local address |
| // of the socket. |
| // |
| if (bgpSession.getLocalAddress() instanceof InetSocketAddress) { |
| InetAddress inetAddr = |
| ((InetSocketAddress) bgpSession.getLocalAddress()).getAddress(); |
| IpAddress ip4Address = IpAddress.valueOf(inetAddr.getAddress()); |
| updateMyBgpId(ip4Address); |
| } |
| return true; |
| } |
| |
| /** |
| * Processes the disconnection from a BGP peer. |
| * |
| * @param bgpSession the BGP session for the peer |
| */ |
| void peerDisconnected(BgpSession bgpSession) { |
| bgpSessions.remove(bgpSession.getRemoteAddress()); |
| } |
| |
| /** |
| * Conditionally updates the local BGP ID if it wasn't set already. |
| * <p/> |
| * NOTE: A BGP instance should use same BGP ID across all BGP sessions. |
| * |
| * @param ip4Address the IPv4 address to use as BGP ID |
| */ |
| private synchronized void updateMyBgpId(IpAddress ip4Address) { |
| if (myBgpId == null) { |
| myBgpId = ip4Address; |
| log.debug("BGP: My BGP ID is {}", myBgpId); |
| } |
| } |
| |
| /** |
| * Gets the local BGP Identifier as an IPv4 address. |
| * |
| * @return the local BGP Identifier as an IPv4 address |
| */ |
| IpAddress getMyBgpId() { |
| return myBgpId; |
| } |
| |
| /** |
| * Gets the BGP Route Selector. |
| * |
| * @return the BGP Route Selector |
| */ |
| BgpRouteSelector getBgpRouteSelector() { |
| return bgpRouteSelector; |
| } |
| |
| /** |
| * Starts up BGP Session Manager operation. |
| * |
| * @param listenPortNumber the port number to listen on. By default |
| * it should be BgpConstants.BGP_PORT (179) |
| */ |
| public void startUp(int listenPortNumber) { |
| log.debug("BGP Session Manager startUp()"); |
| |
| ChannelFactory channelFactory = |
| new NioServerSocketChannelFactory(Executors.newCachedThreadPool(), |
| Executors.newCachedThreadPool()); |
| ChannelPipelineFactory pipelineFactory = new ChannelPipelineFactory() { |
| @Override |
| public ChannelPipeline getPipeline() throws Exception { |
| // Allocate a new session per connection |
| BgpSession bgpSessionHandler = |
| new BgpSession(BgpSessionManager.this); |
| BgpFrameDecoder bgpFrameDecoder = |
| new BgpFrameDecoder(bgpSessionHandler); |
| |
| // Setup the processing pipeline |
| ChannelPipeline pipeline = Channels.pipeline(); |
| pipeline.addLast("BgpFrameDecoder", bgpFrameDecoder); |
| pipeline.addLast("BgpSession", bgpSessionHandler); |
| return pipeline; |
| } |
| }; |
| InetSocketAddress listenAddress = |
| new InetSocketAddress(listenPortNumber); |
| |
| ServerBootstrap serverBootstrap = new ServerBootstrap(channelFactory); |
| // serverBootstrap.setOptions("reuseAddr", true); |
| serverBootstrap.setOption("child.keepAlive", true); |
| serverBootstrap.setOption("child.tcpNoDelay", true); |
| serverBootstrap.setPipelineFactory(pipelineFactory); |
| try { |
| serverChannel = serverBootstrap.bind(listenAddress); |
| } catch (ChannelException e) { |
| log.debug("Exception binding to BGP port {}: ", |
| listenAddress.getPort(), e); |
| } |
| } |
| |
| /** |
| * Shuts down the BGP Session Manager operation. |
| */ |
| public void shutDown() { |
| // TODO: Complete the implementation: remove routes, etc. |
| if (serverChannel != null) { |
| serverChannel.close(); |
| } |
| } |
| |
| /** |
| * Class to receive and process the BGP routes from each BGP Session/Peer. |
| */ |
| class BgpRouteSelector { |
| /** |
| * Processes route entry updates: added/updated and deleted route |
| * entries. |
| * |
| * @param bgpSession the BGP session the route entry updates were |
| * received on |
| * @param addedBgpRouteEntries the added/updated route entries to |
| * process |
| * @param deletedBgpRouteEntries the deleted route entries to process |
| */ |
| synchronized void routeUpdates(BgpSession bgpSession, |
| Collection<BgpRouteEntry> addedBgpRouteEntries, |
| Collection<BgpRouteEntry> deletedBgpRouteEntries) { |
| // |
| // TODO: Merge the updates from different BGP Peers, |
| // by choosing the best route. |
| // |
| |
| // Process the deleted route entries |
| for (BgpRouteEntry bgpRouteEntry : deletedBgpRouteEntries) { |
| processDeletedRoute(bgpSession, bgpRouteEntry); |
| } |
| |
| // Process the added/updated route entries |
| for (BgpRouteEntry bgpRouteEntry : addedBgpRouteEntries) { |
| processAddedRoute(bgpSession, bgpRouteEntry); |
| } |
| } |
| |
| /** |
| * Processes an added/updated route entry. |
| * |
| * @param bgpSession the BGP session the route entry update was |
| * received on |
| * @param bgpRouteEntry the added/updated route entry |
| */ |
| private void processAddedRoute(BgpSession bgpSession, |
| BgpRouteEntry bgpRouteEntry) { |
| RouteUpdate routeUpdate; |
| BgpRouteEntry bestBgpRouteEntry = |
| bgpRoutes.get(bgpRouteEntry.prefix()); |
| |
| // |
| // Install the new route entry if it is better than the |
| // current best route. |
| // |
| if ((bestBgpRouteEntry == null) || |
| bgpRouteEntry.isBetterThan(bestBgpRouteEntry)) { |
| bgpRoutes.put(bgpRouteEntry.prefix(), bgpRouteEntry); |
| routeUpdate = |
| new RouteUpdate(RouteUpdate.Type.UPDATE, bgpRouteEntry); |
| // Forward the result route updates to the Route Listener |
| routeListener.update(routeUpdate); |
| return; |
| } |
| |
| // |
| // If the route entry arrived on the same BGP Session as |
| // the current best route, then elect the next best route |
| // and install it. |
| // |
| if (bestBgpRouteEntry.getBgpSession() != |
| bgpRouteEntry.getBgpSession()) { |
| return; |
| } |
| |
| // Find the next best route |
| bestBgpRouteEntry = findBestBgpRoute(bgpRouteEntry.prefix()); |
| if (bestBgpRouteEntry == null) { |
| // |
| // TODO: Shouldn't happen. Install the new route as a |
| // pre-caution. |
| // |
| log.debug("BGP next best route for prefix {} is missing. " + |
| "Adding the route that is currently processed.", |
| bgpRouteEntry.prefix()); |
| bestBgpRouteEntry = bgpRouteEntry; |
| } |
| // Install the next best route |
| bgpRoutes.put(bestBgpRouteEntry.prefix(), bestBgpRouteEntry); |
| routeUpdate = new RouteUpdate(RouteUpdate.Type.UPDATE, |
| bestBgpRouteEntry); |
| // Forward the result route updates to the Route Listener |
| routeListener.update(routeUpdate); |
| } |
| |
| /** |
| * Processes a deleted route entry. |
| * |
| * @param bgpSession the BGP session the route entry update was |
| * received on |
| * @param bgpRouteEntry the deleted route entry |
| */ |
| private void processDeletedRoute(BgpSession bgpSession, |
| BgpRouteEntry bgpRouteEntry) { |
| RouteUpdate routeUpdate; |
| BgpRouteEntry bestBgpRouteEntry = |
| bgpRoutes.get(bgpRouteEntry.prefix()); |
| |
| // |
| // Remove the route entry only if it was the best one. |
| // Install the the next best route if it exists. |
| // |
| // NOTE: We intentionally use "==" instead of method equals(), |
| // because we need to check whether this is same object. |
| // |
| if (bgpRouteEntry != bestBgpRouteEntry) { |
| return; // Nothing to do |
| } |
| |
| // |
| // Find the next best route |
| // |
| bestBgpRouteEntry = findBestBgpRoute(bgpRouteEntry.prefix()); |
| if (bestBgpRouteEntry != null) { |
| // Install the next best route |
| bgpRoutes.put(bestBgpRouteEntry.prefix(), |
| bestBgpRouteEntry); |
| routeUpdate = new RouteUpdate(RouteUpdate.Type.UPDATE, |
| bestBgpRouteEntry); |
| // Forward the result route updates to the Route Listener |
| routeListener.update(routeUpdate); |
| return; |
| } |
| |
| // |
| // No route found. Remove the route entry |
| // |
| bgpRoutes.remove(bgpRouteEntry.prefix()); |
| routeUpdate = new RouteUpdate(RouteUpdate.Type.DELETE, |
| bgpRouteEntry); |
| // Forward the result route updates to the Route Listener |
| routeListener.update(routeUpdate); |
| } |
| |
| /** |
| * Finds the best route entry among all BGP Sessions. |
| * |
| * @param prefix the prefix of the route |
| * @return the best route if found, otherwise null |
| */ |
| private BgpRouteEntry findBestBgpRoute(IpPrefix prefix) { |
| BgpRouteEntry bestRoute = null; |
| |
| // Iterate across all BGP Sessions and select the best route |
| for (BgpSession bgpSession : bgpSessions.values()) { |
| BgpRouteEntry route = bgpSession.findBgpRouteEntry(prefix); |
| if (route == null) { |
| continue; |
| } |
| if ((bestRoute == null) || route.isBetterThan(bestRoute)) { |
| bestRoute = route; |
| } |
| } |
| return bestRoute; |
| } |
| } |
| } |