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 */
017package org.apache.hadoop.hdfs.server.datanode;
018
019import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_SECURITY_AUTHENTICATION;
020
021import java.net.InetSocketAddress;
022import java.net.ServerSocket;
023import java.nio.channels.ServerSocketChannel;
024
025import org.apache.commons.daemon.Daemon;
026import org.apache.commons.daemon.DaemonContext;
027import org.apache.hadoop.conf.Configuration;
028
029import org.apache.hadoop.hdfs.DFSConfigKeys;
030import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
031import org.apache.hadoop.http.HttpServer;
032import 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 */
038public 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}