svn merge -c 1197330 from branch-0.20-security for HDFS-2527.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-205@1197338 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -57,6 +57,13 @@ Release 0.20.205.1 - unreleased
     HDFS-2065. Add null checks in DFSClient.getFileChecksum(..).  (Uma
     Maheswara Rao G via szetszwo)
 
+    HDFS-2527. WebHdfs: remove the use of "Range" header in Open; use ugi
+    username if renewer parameter is null in GetDelegationToken; response OK
+    when setting replication for non-files; rename GETFILEBLOCKLOCATIONS to
+    GET_BLOCK_LOCATIONS and state that it is a private unstable API; replace
+    isDirectory and isSymlink with enum {FILE, DIRECTORY, SYMLINK} in
+    HdfsFileStatus JSON object.  (szetszwo)
+
 Release 0.20.205.0 - 2011.10.06
 
   NEW FEATURES

src/hdfs/org/apache/hadoop/hdfs/ByteRangeInputStream.java

@@ -18,17 +18,13 @@
 
 package org.apache.hadoop.hdfs;
 
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
-import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.StringTokenizer;
 
 import org.apache.hadoop.fs.FSInputStream;
 import org.apache.hadoop.hdfs.server.namenode.StreamFile;
-import org.apache.hadoop.hdfs.web.resources.OffsetParam;
 
 /**
  * To support HTTP byte streams, a new connection to an HTTP server needs to be
@@ -37,16 +33,14 @@ import org.apache.hadoop.hdfs.web.resources.OffsetParam;
  * is made on the successive read(). The normal input stream functions are 
  * connected to the currently active input stream. 
  */
-public class ByteRangeInputStream extends FSInputStream {
+public abstract class ByteRangeInputStream extends FSInputStream {
   
   /**
    * This class wraps a URL and provides method to open connection.
    * It can be overridden to change how a connection is opened.
    */
-  public static class URLOpener {
+  public static abstract class URLOpener {
     protected URL url;
-    /** The url with offset parameter */
-    protected URL offsetUrl;
   
     public URLOpener(URL u) {
       url = u;
@@ -60,52 +54,9 @@ public class ByteRangeInputStream extends FSInputStream {
       return url;
     }
 
-    protected HttpURLConnection openConnection() throws IOException {
-      return (HttpURLConnection)offsetUrl.openConnection();
-    }
+    protected abstract HttpURLConnection openConnection() throws IOException;
 
-    private HttpURLConnection openConnection(final long offset) throws IOException {
-      offsetUrl = offset == 0L? url: new URL(url + "&" + new OffsetParam(offset));
-      final HttpURLConnection conn = openConnection();
-      conn.setRequestMethod("GET");
-      if (offset != 0L) {
-        conn.setRequestProperty("Range", "bytes=" + offset + "-");
-      }
-      return conn;
-    }  
-  }
-  
-  static private final String OFFSET_PARAM_PREFIX = OffsetParam.NAME + "=";
-
-  /** Remove offset parameter, if there is any, from the url */
-  static URL removeOffsetParam(final URL url) throws MalformedURLException {
-    String query = url.getQuery();
-    if (query == null) {
-      return url;
-    }
-    final String lower = query.toLowerCase();
-    if (!lower.startsWith(OFFSET_PARAM_PREFIX)
-        && !lower.contains("&" + OFFSET_PARAM_PREFIX)) {
-      return url;
-    }
-
-    //rebuild query
-    StringBuilder b = null;
-    for(final StringTokenizer st = new StringTokenizer(query, "&");
-        st.hasMoreTokens();) {
-      final String token = st.nextToken();
-      if (!token.toLowerCase().startsWith(OFFSET_PARAM_PREFIX)) {
-        if (b == null) {
-          b = new StringBuilder("?").append(token);
-        } else {
-          b.append('&').append(token);
-        }
-      }
-    }
-    query = b == null? "": b.toString();
-
-    final String urlStr = url.toString();
-    return new URL(urlStr.substring(0, urlStr.indexOf('?')) + query);
+    protected abstract HttpURLConnection openConnection(final long offset) throws IOException;
   }
 
   enum StreamStatus {
@@ -120,11 +71,6 @@ public class ByteRangeInputStream extends FSInputStream {
 
   StreamStatus status = StreamStatus.SEEK;
 
-  /** Create an input stream with the URL. */
-  public ByteRangeInputStream(final URL url) {
-    this(new URLOpener(url), new URLOpener(null));
-  }
-  
   /**
    * Create with the specified URLOpeners. Original url is used to open the 
    * stream for the first time. Resolved url is used in subsequent requests.
@@ -136,6 +82,12 @@ public class ByteRangeInputStream extends FSInputStream {
     this.resolvedURL = r;
   }
   
+  protected abstract void checkResponseCode(final HttpURLConnection connection
+      ) throws IOException;
+  
+  protected abstract URL getResolvedUrl(final HttpURLConnection connection
+      ) throws IOException;
+
   private InputStream getInputStream() throws IOException {
     if (status != StreamStatus.NORMAL) {
       
@@ -150,32 +102,14 @@ public class ByteRangeInputStream extends FSInputStream {
         (resolvedURL.getURL() == null) ? originalURL : resolvedURL;
 
       final HttpURLConnection connection = opener.openConnection(startPos);
-      try {
-        connection.connect();
-        final String cl = connection.getHeaderField(StreamFile.CONTENT_LENGTH);
-        filelength = (cl == null) ? -1 : Long.parseLong(cl);
-        if (HftpFileSystem.LOG.isDebugEnabled()) {
-          HftpFileSystem.LOG.debug("filelength = " + filelength);
-        }
-        in = connection.getInputStream();
-      } catch (FileNotFoundException fnfe) {
-        throw fnfe;
-      } catch (IOException ioe) {
-        HftpFileSystem.throwIOExceptionFromConnection(connection, ioe);
-      }
-      
-      int respCode = connection.getResponseCode();
-      if (startPos != 0 && respCode != HttpURLConnection.HTTP_PARTIAL) {
-        // We asked for a byte range but did not receive a partial content
-        // response...
-        throw new IOException("HTTP_PARTIAL expected, received " + respCode);
-      } else if (startPos == 0 && respCode != HttpURLConnection.HTTP_OK) {
-        // We asked for all bytes from the beginning but didn't receive a 200
-        // response (none of the other 2xx codes are valid here)
-        throw new IOException("HTTP_OK expected, received " + respCode);
-      }
+      connection.connect();
+      checkResponseCode(connection);
+
+      final String cl = connection.getHeaderField(StreamFile.CONTENT_LENGTH);
+      filelength = (cl == null) ? -1 : Long.parseLong(cl);
+      in = connection.getInputStream();
 
-      resolvedURL.setURL(removeOffsetParam(connection.getURL()));
+      resolvedURL.setURL(getResolvedUrl(connection));
       status = StreamStatus.NORMAL;
     }
     

src/hdfs/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java

@@ -343,9 +343,7 @@ public class DatanodeWebHdfsMethods {
         }
       };
 
-      final int status = offset.getValue() == 0?
-          HttpServletResponse.SC_OK: HttpServletResponse.SC_PARTIAL_CONTENT;
-      return Response.status(status).entity(streaming).type(
+      return Response.ok(streaming).type(
           MediaType.APPLICATION_OCTET_STREAM).build();
     }
     case GETFILECHECKSUM:

src/hdfs/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -41,8 +41,6 @@ import javax.ws.rs.QueryParam;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
-import javax.ws.rs.core.Response.ResponseBuilder;
-import javax.ws.rs.core.Response.Status;
 import javax.ws.rs.core.StreamingOutput;
 
 import org.apache.commons.logging.Log;
@@ -145,8 +143,7 @@ public class NamenodeWebHdfsMethods {
       final NameNode namenode, final UserGroupInformation ugi,
       final String renewer) throws IOException {
     final Credentials c = DelegationTokenSecretManager.createCredentials(
-        namenode, ugi,
-        renewer != null? renewer: request.getUserPrincipal().getName());
+        namenode, ugi, renewer != null? renewer: ugi.getShortUserName());
     final Token<? extends TokenIdentifier> t = c.getAllTokens().iterator().next();
     t.setKind(WebHdfsFileSystem.TOKEN_KIND);
     SecurityUtil.setTokenService(t, namenode.getNameNodeAddress());
@@ -304,8 +301,7 @@ public class NamenodeWebHdfsMethods {
     {
       final boolean b = namenode.setReplication(fullpath, replication.getValue(conf));
       final String js = JsonUtil.toJsonString("boolean", b);
-      final ResponseBuilder r = b? Response.ok(): Response.status(Status.FORBIDDEN);
-      return r.entity(js).type(MediaType.APPLICATION_JSON).build();
+      return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
     case SETOWNER:
     {
@@ -487,7 +483,7 @@ public class NamenodeWebHdfsMethods {
           op.getValue(), offset.getValue(), offset, length, bufferSize);
       return Response.temporaryRedirect(uri).build();
     }
-    case GETFILEBLOCKLOCATIONS:
+    case GET_BLOCK_LOCATIONS:
     {
       final long offsetValue = offset.getValue();
       final Long lengthValue = length.getValue();

src/hdfs/org/apache/hadoop/hdfs/web/JsonUtil.java

@@ -134,6 +134,14 @@ public class JsonUtil {
     return new FsPermission(Short.parseShort(s, 8));
   }
 
+  static enum PathType {
+    FILE, DIRECTORY;
+    
+    static PathType valueOf(HdfsFileStatus status) {
+      return status.isDir()? DIRECTORY: FILE;
+    }
+  }
+
   /** Convert a HdfsFileStatus object to a Json string. */
   public static String toJsonString(final HdfsFileStatus status,
       boolean includeType) {
@@ -142,8 +150,8 @@ public class JsonUtil {
     }
     final Map<String, Object> m = new TreeMap<String, Object>();
     m.put("localName", status.getLocalName());
-    m.put("isDir", status.isDir());
-    m.put("len", status.getLen());
+    m.put("type", PathType.valueOf(status));
+    m.put("length", status.getLen());
     m.put("owner", status.getOwner());
     m.put("group", status.getGroup());
     m.put("permission", toString(status.getPermission()));
@@ -164,8 +172,9 @@ public class JsonUtil {
     final Map<?, ?> m = includesType ? 
         (Map<?, ?>)json.get(HdfsFileStatus.class.getSimpleName()) : json;
     final String localName = (String) m.get("localName");
-    final boolean isDir = (Boolean) m.get("isDir");
-    final long len = (Long) m.get("len");
+    final PathType type = PathType.valueOf((String) m.get("type"));
+
+    final long len = (Long) m.get("length");
     final String owner = (String) m.get("owner");
     final String group = (String) m.get("group");
     final FsPermission permission = toFsPermission((String) m.get("permission"));
@@ -173,8 +182,9 @@ public class JsonUtil {
     final long mTime = (Long) m.get("modificationTime");
     final long blockSize = (Long) m.get("blockSize");
     final short replication = (short) (long) (Long) m.get("replication");
-    return new HdfsFileStatus(len, isDir, replication, blockSize, mTime, aTime,
-        permission, owner, group, DFSUtil.string2Bytes(localName));
+    return new HdfsFileStatus(len, type == PathType.DIRECTORY, replication,
+        blockSize, mTime, aTime, permission, owner, group,
+        DFSUtil.string2Bytes(localName));
   }
 
   /** Convert a Block to a Json map. */

src/hdfs/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -25,10 +25,12 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
+import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.Map;
+import java.util.StringTokenizer;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -511,24 +513,84 @@ public class WebHdfsFileSystem extends FileSystem
     statistics.incrementReadOps(1);
     final HttpOpParam.Op op = GetOpParam.Op.OPEN;
     final URL url = toUrl(op, f, new BufferSizeParam(buffersize));
-    ByteRangeInputStream str = getByteRangeInputStream(url);
-    return new FSDataInputStream(str);
+    return new FSDataInputStream(new OffsetUrlInputStream(
+        new OffsetUrlOpener(url), new OffsetUrlOpener(null)));
   }
 
-  private class URLOpener extends ByteRangeInputStream.URLOpener {
-
-    public URLOpener(URL u) {
-      super(u);
+  class OffsetUrlOpener extends ByteRangeInputStream.URLOpener {
+    /** The url with offset parameter */
+    private URL offsetUrl;
+  
+    OffsetUrlOpener(final URL url) {
+      super(url);
     }
 
+    /** Open connection with offset url. */
     @Override
-    public HttpURLConnection openConnection() throws IOException {
+    protected HttpURLConnection openConnection() throws IOException {
       return getHttpUrlConnection(offsetUrl);
     }
+
+    /** Setup offset url before open connection. */
+    @Override
+    protected HttpURLConnection openConnection(final long offset) throws IOException {
+      offsetUrl = offset == 0L? url: new URL(url + "&" + new OffsetParam(offset));
+      final HttpURLConnection conn = openConnection();
+      conn.setRequestMethod("GET");
+      return conn;
+    }  
   }
-  
-  private ByteRangeInputStream getByteRangeInputStream(URL url) {
-    return new ByteRangeInputStream(new URLOpener(url), new URLOpener(null));
+
+  private static final String OFFSET_PARAM_PREFIX = OffsetParam.NAME + "=";
+
+  /** Remove offset parameter, if there is any, from the url */
+  static URL removeOffsetParam(final URL url) throws MalformedURLException {
+    String query = url.getQuery();
+    if (query == null) {
+      return url;
+    }
+    final String lower = query.toLowerCase();
+    if (!lower.startsWith(OFFSET_PARAM_PREFIX)
+        && !lower.contains("&" + OFFSET_PARAM_PREFIX)) {
+      return url;
+    }
+
+    //rebuild query
+    StringBuilder b = null;
+    for(final StringTokenizer st = new StringTokenizer(query, "&");
+        st.hasMoreTokens();) {
+      final String token = st.nextToken();
+      if (!token.toLowerCase().startsWith(OFFSET_PARAM_PREFIX)) {
+        if (b == null) {
+          b = new StringBuilder("?").append(token);
+        } else {
+          b.append('&').append(token);
+        }
+      }
+    }
+    query = b == null? "": b.toString();
+
+    final String urlStr = url.toString();
+    return new URL(urlStr.substring(0, urlStr.indexOf('?')) + query);
+  }
+
+  static class OffsetUrlInputStream extends ByteRangeInputStream {
+    OffsetUrlInputStream(OffsetUrlOpener o, OffsetUrlOpener r) {
+      super(o, r);
+    }
+    
+    @Override
+    protected void checkResponseCode(final HttpURLConnection connection
+        ) throws IOException {
+      validateResponse(GetOpParam.Op.OPEN, connection);
+    }
+
+    /** Remove offset parameter before returning the resolved url. */
+    @Override
+    protected URL getResolvedUrl(final HttpURLConnection connection
+        ) throws MalformedURLException {
+      return removeOffsetParam(connection.getURL());
+    }
   }
 
   @Override
@@ -605,7 +667,7 @@ public class WebHdfsFileSystem extends FileSystem
     statistics.incrementReadOps(1);
 
     final Path p = status.getPath();
-    final HttpOpParam.Op op = GetOpParam.Op.GETFILEBLOCKLOCATIONS;
+    final HttpOpParam.Op op = GetOpParam.Op.GET_BLOCK_LOCATIONS;
     final Map<?, ?> m = run(op, p, new OffsetParam(offset),
         new LengthParam(length));
     return DFSUtil.locatedBlocks2Locations(JsonUtil.toLocatedBlocks(m));

src/hdfs/org/apache/hadoop/hdfs/web/resources/GetOpParam.java

@@ -24,7 +24,6 @@ public class GetOpParam extends HttpOpParam<GetOpParam.Op> {
   /** Get operations. */
   public static enum Op implements HttpOpParam.Op {
     OPEN(HttpURLConnection.HTTP_OK),
-    GETFILEBLOCKLOCATIONS(HttpURLConnection.HTTP_OK),
 
     GETFILESTATUS(HttpURLConnection.HTTP_OK),
     LISTSTATUS(HttpURLConnection.HTTP_OK),
@@ -33,6 +32,9 @@ public class GetOpParam extends HttpOpParam<GetOpParam.Op> {
 
     GETDELEGATIONTOKEN(HttpURLConnection.HTTP_OK),
 
+    /** GET_BLOCK_LOCATIONS is a private unstable op. */
+    GET_BLOCK_LOCATIONS(HttpURLConnection.HTTP_OK),
+
     NULL(HttpURLConnection.HTTP_NOT_IMPLEMENTED);
 
     final int expectedHttpResponseCode;

src/test/org/apache/hadoop/hdfs/TestByteRangeInputStream.java

@@ -17,24 +17,16 @@
  */
 package org.apache.hadoop.hdfs;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
-import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 
-import org.apache.hadoop.hdfs.ByteRangeInputStream.URLOpener;
 import org.junit.Test;
 
-class MockHttpURLConnection extends HttpURLConnection {
+public class TestByteRangeInputStream {
+public static class MockHttpURLConnection extends HttpURLConnection {
   public MockHttpURLConnection(URL u) {
     super(u);
   }
@@ -86,117 +78,7 @@ class MockHttpURLConnection extends HttpURLConnection {
   }
 }
 
-public class TestByteRangeInputStream {
-  @Test
-  public void testRemoveOffset() throws IOException {
-    { //no offset
-      String s = "http://test/Abc?Length=99";
-      assertEquals(s, ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-
-    { //no parameters
-      String s = "http://test/Abc";
-      assertEquals(s, ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-
-    { //offset as first parameter
-      String s = "http://test/Abc?offset=10&Length=99";
-      assertEquals("http://test/Abc?Length=99",
-          ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-
-    { //offset as second parameter
-      String s = "http://test/Abc?op=read&OFFset=10&Length=99";
-      assertEquals("http://test/Abc?op=read&Length=99",
-          ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-
-    { //offset as last parameter
-      String s = "http://test/Abc?Length=99&offset=10";
-      assertEquals("http://test/Abc?Length=99",
-          ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-
-    { //offset as the only parameter
-      String s = "http://test/Abc?offset=10";
-      assertEquals("http://test/Abc",
-          ByteRangeInputStream.removeOffsetParam(new URL(s)).toString());
-    }
-  }
-  
   @Test
   public void testByteRange() throws IOException {
-    URLOpener ospy = spy(new URLOpener(new URL("http://test/")));
-    doReturn(new MockHttpURLConnection(ospy.getURL())).when(ospy)
-        .openConnection();
-    URLOpener rspy = spy(new URLOpener((URL) null));
-    doReturn(new MockHttpURLConnection(rspy.getURL())).when(rspy)
-        .openConnection();
-    ByteRangeInputStream is = new ByteRangeInputStream(ospy, rspy);
-
-    assertEquals("getPos wrong", 0, is.getPos());
-
-    is.read();
-
-    assertNull("Initial call made incorrectly (Range Check)", ospy
-        .openConnection().getRequestProperty("Range"));
-
-    assertEquals("getPos should be 1 after reading one byte", 1, is.getPos());
-
-    is.read();
-
-    assertEquals("getPos should be 2 after reading two bytes", 2, is.getPos());
-
-    // No additional connections should have been made (no seek)
-
-    rspy.setURL(new URL("http://resolvedurl/"));
-
-    is.seek(100);
-    is.read();
-
-    assertEquals("Seek to 100 bytes made incorrectly (Range Check)",
-        "bytes=100-", rspy.openConnection().getRequestProperty("Range"));
-
-    assertEquals("getPos should be 101 after reading one byte", 101,
-        is.getPos());
-
-    verify(rspy, times(2)).openConnection();
-
-    is.seek(101);
-    is.read();
-
-    verify(rspy, times(2)).openConnection();
-
-    // Seek to 101 should not result in another request"
-
-    is.seek(2500);
-    is.read();
-
-    assertEquals("Seek to 2500 bytes made incorrectly (Range Check)",
-        "bytes=2500-", rspy.openConnection().getRequestProperty("Range"));
-
-    ((MockHttpURLConnection) rspy.openConnection()).setResponseCode(200);
-    is.seek(500);
-    
-    try {
-      is.read();
-      fail("Exception should be thrown when 200 response is given "
-           + "but 206 is expected");
-    } catch (IOException e) {
-      assertEquals("Should fail because incorrect response code was sent",
-                   "HTTP_PARTIAL expected, received 200", e.getMessage());
-    }
-
-    ((MockHttpURLConnection) rspy.openConnection()).setResponseCode(206);
-    is.seek(0);
-
-    try {
-      is.read();
-      fail("Exception should be thrown when 206 response is given "
-           + "but 200 is expected");
-    } catch (IOException e) {
-      assertEquals("Should fail because incorrect response code was sent",
-                   "HTTP_OK expected, received 206", e.getMessage());
-    }
   }
 }

src/test/org/apache/hadoop/hdfs/web/TestOffsetUrlInputStream.java

@@ -0,0 +1,137 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.web;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URL;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.hdfs.TestByteRangeInputStream.MockHttpURLConnection;
+import org.apache.hadoop.hdfs.web.WebHdfsFileSystem.OffsetUrlInputStream;
+import org.apache.hadoop.hdfs.web.WebHdfsFileSystem.OffsetUrlOpener;
+import org.junit.Test;
+
+public class TestOffsetUrlInputStream {
+  @Test
+  public void testRemoveOffset() throws IOException {
+    { //no offset
+      String s = "http://test/Abc?Length=99";
+      assertEquals(s, WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+
+    { //no parameters
+      String s = "http://test/Abc";
+      assertEquals(s, WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+
+    { //offset as first parameter
+      String s = "http://test/Abc?offset=10&Length=99";
+      assertEquals("http://test/Abc?Length=99",
+          WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+
+    { //offset as second parameter
+      String s = "http://test/Abc?op=read&OFFset=10&Length=99";
+      assertEquals("http://test/Abc?op=read&Length=99",
+          WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+
+    { //offset as last parameter
+      String s = "http://test/Abc?Length=99&offset=10";
+      assertEquals("http://test/Abc?Length=99",
+          WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+
+    { //offset as the only parameter
+      String s = "http://test/Abc?offset=10";
+      assertEquals("http://test/Abc",
+          WebHdfsFileSystem.removeOffsetParam(new URL(s)).toString());
+    }
+  }
+  
+  @Test
+  public void testByteRange() throws Exception {
+    final Configuration conf = new Configuration(); 
+    final String uri = WebHdfsFileSystem.SCHEME  + "://localhost:50070/";
+    final WebHdfsFileSystem webhdfs = (WebHdfsFileSystem)FileSystem.get(new URI(uri), conf);
+
+    OffsetUrlOpener ospy = spy(webhdfs.new OffsetUrlOpener(new URL("http://test/")));
+    doReturn(new MockHttpURLConnection(ospy.getURL())).when(ospy)
+        .openConnection();
+    OffsetUrlOpener rspy = spy(webhdfs.new OffsetUrlOpener((URL) null));
+    doReturn(new MockHttpURLConnection(rspy.getURL())).when(rspy)
+        .openConnection();
+    final OffsetUrlInputStream is = new OffsetUrlInputStream(ospy, rspy);
+
+    assertEquals("getPos wrong", 0, is.getPos());
+
+    is.read();
+
+    assertNull("Initial call made incorrectly (Range Check)", ospy
+        .openConnection().getRequestProperty("Range"));
+
+    assertEquals("getPos should be 1 after reading one byte", 1, is.getPos());
+
+    is.read();
+
+    assertEquals("getPos should be 2 after reading two bytes", 2, is.getPos());
+
+    // No additional connections should have been made (no seek)
+
+    rspy.setURL(new URL("http://resolvedurl/"));
+
+    is.seek(100);
+    is.read();
+
+    assertEquals("getPos should be 101 after reading one byte", 101,
+        is.getPos());
+
+    verify(rspy, times(1)).openConnection();
+
+    is.seek(101);
+    is.read();
+
+    verify(rspy, times(1)).openConnection();
+
+    // Seek to 101 should not result in another request"
+
+    is.seek(2500);
+    is.read();
+
+    ((MockHttpURLConnection) rspy.openConnection()).setResponseCode(206);
+    is.seek(0);
+
+    try {
+      is.read();
+      fail("Exception should be thrown when 206 response is given "
+           + "but 200 is expected");
+    } catch (IOException e) {
+      WebHdfsFileSystem.LOG.info(e.toString());
+    }
+  }
+}

src/test/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java

@@ -300,7 +300,7 @@ public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
       final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
       conn.setRequestMethod(op.getType().toString());
       conn.connect();
-      assertEquals(HttpServletResponse.SC_FORBIDDEN, conn.getResponseCode());
+      assertEquals(HttpServletResponse.SC_OK, conn.getResponseCode());
       
       assertFalse(webhdfs.setReplication(dir, (short)1));
       conn.disconnect();