flush data on BUFFER_OVERFLOW

Author: pontusmelke

driver/src/main/java/org/neo4j/driver/internal/connector/socket/TLSSocketChannel.java

@@ -28,9 +28,9 @@
 import javax.net.ssl.SSLEngineResult.HandshakeStatus;
 import javax.net.ssl.SSLEngineResult.Status;
 
-import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.internal.util.BytePrinter;
 import org.neo4j.driver.v1.Config.TrustStrategy;
+import org.neo4j.driver.v1.Logger;
 import org.neo4j.driver.v1.exceptions.ClientException;
 
 import static javax.net.ssl.SSLEngineResult.HandshakeStatus.FINISHED;
@@ -163,8 +163,8 @@ private HandshakeStatus runDelegatedTasks()
      * To verify if deciphering is done successfully, we could check if any bytes has been read into {@code buffer},
      * as the deciphered bytes will only be saved into {@code buffer} when deciphering is carried out successfully.
      *
-     * @param buffer
-     * @return
+     * @param buffer to read data into.
+     * @return The status of the current handshake.
      * @throws IOException
      */
     private HandshakeStatus unwrap( ByteBuffer buffer ) throws IOException
@@ -261,7 +261,7 @@ private HandshakeStatus unwrap( ByteBuffer buffer ) throws IOException
      * a loop
      *
      * @param buffer contains the bytes to send to channel
-     * @return
+     * @return The status of the current handshake
      * @throws IOException
      */
     private HandshakeStatus wrap( ByteBuffer buffer ) throws IOException
@@ -277,7 +277,7 @@ private HandshakeStatus wrap( ByteBuffer buffer ) throws IOException
         case OK:
             handshakeStatus = runDelegatedTasks();
             cipherOut.flip();
-            while(cipherOut.hasRemaining())
+            while ( cipherOut.hasRemaining() )
             {
                 channel.write( cipherOut );
             }
@@ -287,19 +287,30 @@ private HandshakeStatus wrap( ByteBuffer buffer ) throws IOException
             // Enlarge the buffer and return the old status
             int curNetSize = cipherOut.capacity();
             int netSize = sslEngine.getSession().getPacketBufferSize();
-            if ( curNetSize >= netSize || buffer.capacity() > netSize )
+            if ( netSize > curNetSize )
             {
-                // TODO
-                throw new ClientException(
-                        String.format( "Failed to enlarge network buffer from %s to %s. This is either because the " +
-                                       "new size is however less than the old size, or because the application " +
-                                       "buffer size %s is so big that the application data still cannot fit into the " +
-                                       "new network buffer.", curNetSize, netSize, buffer.capacity() ) );
+                // enlarge the peer application data buffer
+                cipherOut = ByteBuffer.allocate( netSize );
+                logger.debug( "Enlarged network output buffer from %s to %s. " +
+                              "This operation should be a rare operation.", curNetSize, netSize );
+            }
+            else
+            {
+                // flush as much data as possible
+                cipherOut.flip();
+                int written = channel.write( cipherOut );
+                if (written == 0)
+                {
+                    throw new ClientException(
+                            String.format(
+                                    "Failed to enlarge network buffer from %s to %s. This is either because the " +
+                                    "new size is however less than the old size, or because the application " +
+                                    "buffer size %s is so big that the application data still cannot fit into the " +
+                                    "new network buffer.", curNetSize, netSize, buffer.capacity() ) );
+                }
+                cipherOut.compact();
+                logger.debug( "Network output buffer couldn't be enlarged, flushing data to the channel instead." );
             }
-
-            cipherOut = ByteBuffer.allocate( netSize );
-            logger.debug( "Enlarged network output buffer from %s to %s. " +
-                          "This operation should be a rare operation.", curNetSize, netSize );
             break;
         default:
             throw new ClientException( "Got unexpected status " + status );
@@ -320,9 +331,9 @@ private HandshakeStatus wrap( ByteBuffer buffer ) throws IOException
      * After the method call, the new position of {@code from.pos} will be {@code from.pos + p}, and similarly,
      * the new position of {@code to.pos} will be {@code to.pos + p}
      *
-     * @param from
-     * @param to
-     * @return
+     * @param from buffer to copy from
+     * @param to buffer to copy to
+     * @return the number of transferred bytes
      */
     static int bufferCopy( ByteBuffer from, ByteBuffer to )
     {
@@ -341,9 +352,9 @@ static int bufferCopy( ByteBuffer from, ByteBuffer to )
 
     /**
      * Create SSLEngine with the SSLContext just created.
-     * @param host
-     * @param port
-     * @param sslContext
+     * @param host the host to connect to
+     * @param port the port to connect to
+     * @param sslContext the current ssl context
      */
     private static SSLEngine createSSLEngine( String host, int port, SSLContext sslContext )
     {
@@ -431,10 +442,10 @@ public void close() throws IOException
             channel.close();
             logger.debug( "TLS connection closed" );
         }
-        catch(IOException e)
+        catch ( IOException e )
         {
             // Treat this as ok - the connection is closed, even if the TLS session did not exit cleanly.
-            logger.warn( "TLS socket could not be closed cleanly: '"+e.getMessage()+"'", e );
+            logger.warn( "TLS socket could not be closed cleanly: '" + e.getMessage() + "'", e );
         }
     }
 

driver/src/test/java/org/neo4j/driver/v1/integration/TLSSocketChannelFragmentation.java

@@ -1,3 +1,21 @@
+/**
+ * Copyright (c) 2002-2016 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed 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.neo4j.driver.v1.integration;
 
 import org.junit.Before;