001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements. See the NOTICE file distributed with this
004     * work for additional information regarding copyright ownership. The ASF
005     * licenses this file to you under the Apache License, Version 2.0 (the
006     * "License"); you may not use this file except in compliance with the License.
007     * You may obtain a copy of the License at
008     * 
009     * http://www.apache.org/licenses/LICENSE-2.0
010     * 
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
013     * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
014     * License for the specific language governing permissions and limitations under
015     * the License.
016     */
017    package org.apache.hadoop.hdfs.server.datanode;
018    
019    import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_SECURITY_AUTHENTICATION;
020    
021    import java.net.InetSocketAddress;
022    import java.net.ServerSocket;
023    import java.nio.channels.ServerSocketChannel;
024    
025    import org.apache.commons.daemon.Daemon;
026    import org.apache.commons.daemon.DaemonContext;
027    import org.apache.hadoop.conf.Configuration;
028    
029    import org.apache.hadoop.hdfs.DFSConfigKeys;
030    import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
031    import org.apache.hadoop.http.HttpServer;
032    import org.mortbay.jetty.nio.SelectChannelConnector;
033    
034    /**
035     * Utility class to start a datanode in a secure cluster, first obtaining 
036     * privileged resources before main startup and handing them to the datanode.
037     */
038    public class SecureDataNodeStarter implements Daemon {
039      /**
040       * Stash necessary resources needed for datanode operation in a secure env.
041       */
042      public static class SecureResources {
043        private final ServerSocket streamingSocket;
044        private final SelectChannelConnector listener;
045        public SecureResources(ServerSocket streamingSocket,
046            SelectChannelConnector listener) {
047    
048          this.streamingSocket = streamingSocket;
049          this.listener = listener;
050        }
051    
052        public ServerSocket getStreamingSocket() { return streamingSocket; }
053    
054        public SelectChannelConnector getListener() { return listener; }
055      }
056      
057      private String [] args;
058      private SecureResources resources;
059      
060      @Override
061      public void init(DaemonContext context) throws Exception {
062        System.err.println("Initializing secure datanode resources");
063        // We should only start up a secure datanode in a Kerberos-secured cluster
064        Configuration conf = new Configuration(); // Skip UGI method to not log in
065        if(!conf.get(HADOOP_SECURITY_AUTHENTICATION).equals("kerberos"))
066          throw new RuntimeException("Cannot start secure datanode in unsecure cluster");
067        
068        // Stash command-line arguments for regular datanode
069        args = context.getArguments();
070        
071        // Obtain secure port for data streaming to datanode
072        InetSocketAddress socAddr = DataNode.getStreamingAddr(conf);
073        int socketWriteTimeout = conf.getInt(DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY,
074            HdfsServerConstants.WRITE_TIMEOUT);
075        
076        ServerSocket ss = (socketWriteTimeout > 0) ? 
077            ServerSocketChannel.open().socket() : new ServerSocket();
078        ss.bind(socAddr, 0);
079        
080        // Check that we got the port we need
081        if(ss.getLocalPort() != socAddr.getPort())
082          throw new RuntimeException("Unable to bind on specified streaming port in secure " +
083                    "context. Needed " + socAddr.getPort() + ", got " + ss.getLocalPort());
084    
085        // Obtain secure listener for web server
086        SelectChannelConnector listener = 
087                       (SelectChannelConnector)HttpServer.createDefaultChannelConnector();
088        InetSocketAddress infoSocAddr = DataNode.getInfoAddr(conf);
089        listener.setHost(infoSocAddr.getHostName());
090        listener.setPort(infoSocAddr.getPort());
091        // Open listener here in order to bind to port as root
092        listener.open(); 
093        if(listener.getPort() != infoSocAddr.getPort())
094          throw new RuntimeException("Unable to bind on specified info port in secure " +
095              "context. Needed " + socAddr.getPort() + ", got " + ss.getLocalPort());
096        System.err.println("Successfully obtained privileged resources (streaming port = "
097            + ss + " ) (http listener port = " + listener.getConnection() +")");
098        
099        if(ss.getLocalPort() >= 1023 || listener.getPort() >= 1023)
100          throw new RuntimeException("Cannot start secure datanode with unprivileged ports");
101        
102        resources = new SecureResources(ss, listener);
103      }
104    
105      @Override
106      public void start() throws Exception {
107        System.err.println("Starting regular datanode initialization");
108        DataNode.secureMain(args, resources);
109      }
110      
111      @Override public void destroy() { /* Nothing to do */ }
112      @Override public void stop() throws Exception { /* Nothing to do */ }
113    }