Merge pull request #223 from guusdk/OF-883

OF-883: Prevent sending data to known disconnected peers.

src/java/org/jivesoftware/openfire/Connection.java

@@ -144,9 +144,29 @@ public interface Connection {
      *      <li>Call notifyEvent all listeners that the channel is shutting down.
      *      <li>Close the socket.
      * </ul>
+     *
+     * An invocation of this method is equal to invoking {@link #close(boolean)} with a parameter
+     * that is false.
      */
     public void close();
 
+    /**
+     * Close this session including associated socket connection. The order of
+     * events for closing the session is:
+     * <ul>
+     *      <li>Set closing flag to prevent redundant shutdowns.
+     *      <li>Call notifyEvent all listeners that the channel is shutting down.
+     *      <li>Close the socket.
+     * </ul>
+     *
+     * This method takes into account the connection state of the peer. Specifically,
+     * when the peer is known to be in a disconnected state, no data will be sent
+     * (otherwise, this method can trigger the delivery of an end-of-stream signal).
+     *
+     * @param peerIsKnownToBeDisconnected should be set to true when the peer is known to no longer be available.
+     */
+    public void close( boolean peerIsKnownToBeDisconnected );
+
     /**
      * Notification message indicating that the server is being shutdown. Implementors
      * should send a stream error whose condition is system-shutdown before closing

src/java/org/jivesoftware/openfire/net/SocketConnection.java

@@ -442,6 +442,10 @@ public class SocketConnection implements Connection {
     }
 
     public void close() {
+        close( false );
+    }
+
+    public void close( boolean peerIsKnownToBeDisconnected ) {
         boolean wasClosed = false;
         synchronized (this) {
             if (!isClosed()) {
@@ -449,26 +453,29 @@ public class SocketConnection implements Connection {
                     if (session != null) {
                         session.setStatus(Session.STATUS_CLOSED);
                     }
-                    boolean allowedToWrite = false;
-                    try {
-                        requestWriting();
-                        allowedToWrite = true;
-                        // Register that we started sending data on the connection
-                        writeStarted();
-                        writer.write("</stream:stream>");
-                        if (flashClient) {
-                            writer.write('\0');
+
+                    if ( !peerIsKnownToBeDisconnected ) {
+                        boolean allowedToWrite = false;
+                        try {
+                            requestWriting();
+                            allowedToWrite = true;
+                            // Register that we started sending data on the connection
+                            writeStarted();
+                            writer.write("</stream:stream>");
+                            if (flashClient) {
+                                writer.write('\0');
+                            }
+                            writer.flush();
                         }
-                        writer.flush();
-                    }
-                    catch (IOException e) {
-                        // Do nothing
-                    }
-                    finally {
-                        // Register that we finished sending data on the connection
-                        writeFinished();
-                        if (allowedToWrite) {
-                            releaseWriting();
+                        catch (IOException e) {
+                            // Do nothing
+                        }
+                        finally {
+                            // Register that we finished sending data on the connection
+                            writeFinished();
+                            if (allowedToWrite) {
+                                releaseWriting();
+                            }
                         }
                     }
                 }

src/java/org/jivesoftware/openfire/net/VirtualConnection.java

@@ -169,6 +169,10 @@ public abstract class VirtualConnection implements Connection {
      * has been closed.
      */
     public void close() {
+        close( false );
+    }
+
+    public void close(boolean peerIsKnownToBeDisconnected) {
         boolean wasClosed = false;
         synchronized (this) {
             if (!isClosed()) {

src/java/org/jivesoftware/openfire/nio/ConnectionHandler.java

@@ -111,7 +111,7 @@ public abstract class ConnectionHandler extends IoHandlerAdapter {
     public void inputClosed( IoSession session ) throws Exception {
         final Connection connection = (Connection) session.getAttribute(CONNECTION);
         if ( connection != null ) {
-            connection.close();
+            connection.close( true );
         }
     }
 

src/java/org/jivesoftware/openfire/nio/NIOConnection.java

@@ -219,7 +219,11 @@ public class NIOConnection implements Connection {
         return backupDeliverer;
     }
 
-    public void close()
+    public void close() {
+        close( false );
+    }
+
+    public void close( boolean peerIsKnownToBeDisconnected )
     {
         boolean notifyClose = false;
         synchronized ( this ) {
@@ -234,13 +238,16 @@ public class NIOConnection implements Connection {
                 if ( state != State.CLOSING )
                 {
                     state = State.CLOSING;
-                    try
-                    {
-                        deliverRawText( flashClient ? "</flash:stream>" : "</stream:stream>" );
-                    }
-                    catch ( Exception e )
+                    if ( !peerIsKnownToBeDisconnected )
                     {
-                        // Ignore
+                        try
+                        {
+                            deliverRawText( flashClient ? "</flash:stream>" : "</stream:stream>" );
+                        }
+                        catch ( Exception e )
+                        {
+                            // Ignore
+                        }
                     }
                 }