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 java.net.InetSocketAddress;
020import java.net.ServerSocket;
021import java.nio.channels.ServerSocketChannel;
022
023import org.apache.commons.daemon.Daemon;
024import org.apache.commons.daemon.DaemonContext;
025import org.apache.hadoop.conf.Configuration;
026import org.apache.hadoop.hdfs.DFSConfigKeys;
027import org.apache.hadoop.hdfs.DFSUtil;
028import org.apache.hadoop.hdfs.HdfsConfiguration;
029import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
030import org.apache.hadoop.http.HttpConfig;
031import org.apache.hadoop.http.HttpServer2;
032import org.apache.hadoop.security.UserGroupInformation;
033import org.mortbay.jetty.Connector;
034
035import com.google.common.annotations.VisibleForTesting;
036
037/**
038 * Utility class to start a datanode in a secure cluster, first obtaining 
039 * privileged resources before main startup and handing them to the datanode.
040 */
041public class SecureDataNodeStarter implements Daemon {
042  /**
043   * Stash necessary resources needed for datanode operation in a secure env.
044   */
045  public static class SecureResources {
046    private final ServerSocket streamingSocket;
047    private final Connector listener;
048    public SecureResources(ServerSocket streamingSocket,
049        Connector listener) {
050
051      this.streamingSocket = streamingSocket;
052      this.listener = listener;
053    }
054
055    public ServerSocket getStreamingSocket() { return streamingSocket; }
056
057    public Connector getListener() { return listener; }
058  }
059  
060  private String [] args;
061  private SecureResources resources;
062
063  @Override
064  public void init(DaemonContext context) throws Exception {
065    System.err.println("Initializing secure datanode resources");
066    // Create a new HdfsConfiguration object to ensure that the configuration in
067    // hdfs-site.xml is picked up.
068    Configuration conf = new HdfsConfiguration();
069    
070    // Stash command-line arguments for regular datanode
071    args = context.getArguments();
072    resources = getSecureResources(conf);
073  }
074
075  @Override
076  public void start() throws Exception {
077    System.err.println("Starting regular datanode initialization");
078    DataNode.secureMain(args, resources);
079  }
080
081  @Override public void destroy() {}
082  @Override public void stop() throws Exception { /* Nothing to do */ }
083
084  /**
085   * Acquire privileged resources (i.e., the privileged ports) for the data
086   * node. The privileged resources consist of the port of the RPC server and
087   * the port of HTTP (not HTTPS) server.
088   */
089  @VisibleForTesting
090  public static SecureResources getSecureResources(Configuration conf)
091      throws Exception {
092    HttpConfig.Policy policy = DFSUtil.getHttpPolicy(conf);
093    boolean isSecure = UserGroupInformation.isSecurityEnabled();
094
095    // Obtain secure port for data streaming to datanode
096    InetSocketAddress streamingAddr  = DataNode.getStreamingAddr(conf);
097    int socketWriteTimeout = conf.getInt(
098        DFSConfigKeys.DFS_DATANODE_SOCKET_WRITE_TIMEOUT_KEY,
099        HdfsServerConstants.WRITE_TIMEOUT);
100
101    ServerSocket ss = (socketWriteTimeout > 0) ? 
102        ServerSocketChannel.open().socket() : new ServerSocket();
103    ss.bind(streamingAddr, 0);
104
105    // Check that we got the port we need
106    if (ss.getLocalPort() != streamingAddr.getPort()) {
107      throw new RuntimeException(
108          "Unable to bind on specified streaming port in secure "
109              + "context. Needed " + streamingAddr.getPort() + ", got "
110              + ss.getLocalPort());
111    }
112
113    if (ss.getLocalPort() > 1023 && isSecure) {
114      throw new RuntimeException(
115        "Cannot start secure datanode with unprivileged RPC ports");
116    }
117
118    System.err.println("Opened streaming server at " + streamingAddr);
119
120    // Bind a port for the web server. The code intends to bind HTTP server to
121    // privileged port only, as the client can authenticate the server using
122    // certificates if they are communicating through SSL.
123    Connector listener = null;
124    if (policy.isHttpEnabled()) {
125      listener = HttpServer2.createDefaultChannelConnector();
126      InetSocketAddress infoSocAddr = DataNode.getInfoAddr(conf);
127      listener.setHost(infoSocAddr.getHostName());
128      listener.setPort(infoSocAddr.getPort());
129      // Open listener here in order to bind to port as root
130      listener.open();
131      if (listener.getPort() != infoSocAddr.getPort()) {
132        throw new RuntimeException("Unable to bind on specified info port in secure " +
133            "context. Needed " + streamingAddr.getPort() + ", got " + ss.getLocalPort());
134      }
135      System.err.println("Successfully obtained privileged resources (streaming port = "
136          + ss + " ) (http listener port = " + listener.getConnection() +")");
137
138      if (listener.getPort() > 1023 && isSecure) {
139        throw new RuntimeException(
140            "Cannot start secure datanode with unprivileged HTTP ports");
141      }
142      System.err.println("Opened info server at " + infoSocAddr);
143    }
144
145    return new SecureResources(ss, listener);
146  }
147
148}