Fix merge error.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1598876 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -398,6 +398,10 @@ public class DataNode extends Configured
   private Configuration conf;
 
   private final String userWithLocalPathAccess;
+  private String supergroup;
+  private boolean isPermissionEnabled;
+  private String dnUserName = null;
+
 
   /**
    * Create the DataNode given a configuration and an array of dataDirs.
@@ -419,6 +423,11 @@ public class DataNode extends Configured
 
     this.userWithLocalPathAccess = conf
         .get(DFSConfigKeys.DFS_BLOCK_LOCAL_PATH_ACCESS_USER_KEY);
+    this.supergroup = conf.get(DFSConfigKeys.DFS_PERMISSIONS_SUPERUSERGROUP_KEY,
+        DFSConfigKeys.DFS_PERMISSIONS_SUPERUSERGROUP_DEFAULT);
+    this.isPermissionEnabled = conf.getBoolean(
+        DFSConfigKeys.DFS_PERMISSIONS_ENABLED_KEY,
+        DFSConfigKeys.DFS_PERMISSIONS_ENABLED_DEFAULT);
     try {
       confHostName = getHostName(conf);
       hostName = confHostName;
@@ -525,6 +534,33 @@ public class DataNode extends Configured
       ipcServer.refreshServiceAcl(conf, new HDFSPolicyProvider());
     }
   }
+
+  /** Check whether the current user is in the superuser group. */
+  private void checkSuperuserPrivilege() throws IOException, AccessControlException {
+    if (!isPermissionEnabled) {
+      return;
+    }
+    // Try to get the ugi in the RPC call.
+    UserGroupInformation callerUgi = ipcServer.getRemoteUser();
+    if (callerUgi == null) {
+      // This is not from RPC.
+      callerUgi = UserGroupInformation.getCurrentUser();
+    }
+
+    // Is this by the DN user itself?
+    assert dnUserName != null;
+    if (callerUgi.getShortUserName().equals(dnUserName)) {
+      return;
+    }
+
+    // Is the user a member of the super group?
+    List<String> groups = Arrays.asList(callerUgi.getGroupNames());
+    if (groups.contains(supergroup)) {
+      return;
+    }
+    // Not a superuser.
+    throw new AccessControlException();
+  }
   
 /**
  * Initialize the datanode's periodic scanners:
@@ -704,6 +740,11 @@ public class DataNode extends Configured
   
     // BlockPoolTokenSecretManager is required to create ipc server.
     this.blockPoolTokenSecretManager = new BlockPoolTokenSecretManager();
+    // Login is done by now. Set the DN user name.
+    dnUserName = UserGroupInformation.getCurrentUser().getShortUserName();
+    LOG.info("dnUserName = " + dnUserName);
+    LOG.info("supergroup = " + supergroup);
+
     initIpcServer(conf);
 
     metrics = DataNodeMetrics.create(conf, getMachineName());
@@ -2230,6 +2271,7 @@ public class DataNode extends Configured
 
   @Override //ClientDatanodeProtocol
   public void refreshNamenodes() throws IOException {
+    checkSuperuserPrivilege();
     conf = new Configuration();
     refreshNamenodes(conf);
   }
@@ -2237,6 +2279,7 @@ public class DataNode extends Configured
   @Override // ClientDatanodeProtocol
   public void deleteBlockPool(String blockPoolId, boolean force)
       throws IOException {
+    checkSuperuserPrivilege();
     LOG.info("deleteBlockPool command received for block pool " + blockPoolId
         + ", force=" + force);
     if (blockPoolManager.get(blockPoolId) != null) {