commit 3247d13a436d8997d75c6bd8a5f0d5f993c72e0a

Author: Jitendra Nath Pandey <jitendra@sufferhome-lm.(none)>
Date:   Tue Mar 9 23:39:13 2010 -0800

    HDFS-992 from https://issues.apache.org/jira/secure/attachment/12438371/h992-BK-0.20-07.1.patch
    
    +++ b/YAHOO-CHANGES.txt
    +    HDFS-992. A bug in backport for HDFS-992. (jitendra)
    +


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-patches@1077305 13f79535-47bb-0310-9956-ffa450edef68

src/hdfs/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -32,6 +32,7 @@ import java.net.UnknownHostException;
 import java.nio.channels.ServerSocketChannel;
 import java.nio.channels.SocketChannel;
 import java.security.NoSuchAlgorithmException;
+import java.security.PrivilegedExceptionAction;
 import java.security.SecureRandom;
 import java.util.AbstractList;
 import java.util.ArrayList;
@@ -480,14 +481,26 @@ public class DataNode extends Configured
   } 
 
   public static InterDatanodeProtocol createInterDataNodeProtocolProxy(
-      DatanodeID datanodeid, Configuration conf) throws IOException {
-    InetSocketAddress addr = NetUtils.createSocketAddr(
+      DatanodeID datanodeid, final Configuration conf) throws IOException {
+    final InetSocketAddress addr = NetUtils.createSocketAddr(
         datanodeid.getHost() + ":" + datanodeid.getIpcPort());
     if (InterDatanodeProtocol.LOG.isDebugEnabled()) {
       InterDatanodeProtocol.LOG.info("InterDatanodeProtocol addr=" + addr);
     }
-    return (InterDatanodeProtocol)RPC.getProxy(InterDatanodeProtocol.class,
-        InterDatanodeProtocol.versionID, addr, conf);
+
+    UserGroupInformation loginUgi = UserGroupInformation.getLoginUser();
+    try {
+      return loginUgi
+          .doAs(new PrivilegedExceptionAction<InterDatanodeProtocol>() {
+            public InterDatanodeProtocol run() throws IOException {
+              return (InterDatanodeProtocol) RPC.getProxy(
+                  InterDatanodeProtocol.class, InterDatanodeProtocol.versionID,
+                  addr, conf);
+            }
+          });
+    } catch (InterruptedException ie) {
+      throw new IOException(ie.getMessage());
+    }
   }
 
   public InetSocketAddress getNameNodeAddr() {