Fixed DoS attack that could bring the server down. JM-1289

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/branches/openfire_3_5_0@10031 b35dd754-fafc-0310-a699-88a17e54d16e

documentation/dist/changelog.html

@@ -188,6 +188,7 @@ hr {
 
 <h3>Openfire Bug Fixes</h3>
 <ul>
+<li>[<a href='http://www.igniterealtime.org/issues/browse/JM-1289'>JM-1289</a>] - <font color="red"><b>!</b></font> Fixed DoS attack that could bring the server down.</li>
 <li>[<a href='http://www.igniterealtime.org/issues/browse/JM-1175'>JM-1175</a>] - Fixed double-byte characters problem. <b>(4 votes)</b></li>
 <li>[<a href='http://www.igniterealtime.org/issues/browse/JM-1274'>JM-1274</a>] - Fixed sending of presence packets when using direct presences.</li>
 <li>[<a href='http://www.igniterealtime.org/issues/browse/JM-1275'>JM-1275</a>] - Messages sent to bare JIDs were not considering directed presences.</li>

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

+/**
+ * $RCSfile: ConnectionManagerImpl.java,v $
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright (C) 2008 Jive Software. All rights reserved.
+ *
+ * This software is published under the terms of the GNU Public License (GPL),
+ * a copy of which is included in this distribution.
+ */
+
+package org.jivesoftware.openfire.net;
+
+import org.apache.mina.common.IoFilterAdapter;
+import org.apache.mina.common.IoSession;
+import org.jivesoftware.util.Log;
+import org.jivesoftware.util.JiveGlobals;
+
+import java.io.IOException;
+import java.util.Date;
+
+/**
+ * MINA filter that will close sessions that are failing to read outgoing traffic
+ * and whose outgoing queue is around 5MB. Use the system property <tt>session.stalled.cap</tt>
+ * to set the max number of bytes allowed in the outgoing queue of a session before considering
+ * it stalled.
+ *
+ * @author Gaston Dombiak
+ */
+public class StalledSessionsFilter extends IoFilterAdapter {
+    private static final int bytesCap = JiveGlobals.getIntProperty("session.stalled.cap", 5242880);
+
+    public void filterWrite(NextFilter nextFilter, IoSession session, WriteRequest writeRequest)
+            throws Exception {
+        // Get number of pending requests
+        int pendingBytes = session.getScheduledWriteBytes();
+        if (pendingBytes > bytesCap) {
+            // Get last time we were able to send something to the connected client
+            long writeTime = session.getLastWriteTime();
+            int pendingRequests = session.getScheduledWriteRequests();
+            Log.debug("About to kill session with pendingBytes: " + pendingBytes + " pendingWrites: " +
+                    pendingRequests + " lastWrite: " + new Date(writeTime) + "session: " + session);
+            // Close the session and throw an exception
+            session.close();
+            throw new IOException("Closing session that seems to be stalled. Preventing OOM");
+        }
+        // Call next filter (everything is fine)
+        super.filterWrite(nextFilter, session, writeRequest);
+    }
+}

src/java/org/jivesoftware/openfire/spi/ConnectionManagerImpl.java

 /**
  * $RCSfile: ConnectionManagerImpl.java,v $
- * $Revision: 3159 $
- * $Date: 2005-12-04 22:56:40 -0300 (Sun, 04 Dec 2005) $
+ * $Revision: $
+ * $Date: $
  *
- * Copyright (C) 2007 Jive Software. All rights reserved.
+ * Copyright (C) 2008 Jive Software. All rights reserved.
  *
  * This software is published under the terms of the GNU Public License (GPL),
  * a copy of which is included in this distribution.
@@ -324,6 +324,8 @@ public class ConnectionManagerImpl extends BasicModule implements ConnectionMana
             socketAcceptor.getDefaultConfig().setThreadModel(threadModel);
             // Add the XMPP codec filter
             socketAcceptor.getFilterChain().addFirst("xmpp", new ProtocolCodecFilter(new XMPPCodecFactory()));
+            // Kill sessions whose outgoing queues keep growing and fail to send traffic
+            socketAcceptor.getFilterChain().addAfter("xmpp", "outCap", new StalledSessionsFilter());
         }
     }
 
@@ -408,6 +410,8 @@ public class ConnectionManagerImpl extends BasicModule implements ConnectionMana
                 // Add the XMPP codec filter
                 sslSocketAcceptor.getFilterChain().addFirst("xmpp", new ProtocolCodecFilter(new XMPPCodecFactory()));
                 sslSocketAcceptor.getFilterChain().addFirst("threadModel", executorFilter);
+                // Kill sessions whose outgoing queues keep growing and fail to send traffic
+                sslSocketAcceptor.getFilterChain().addAfter("xmpp", "outCap", new StalledSessionsFilter());
 
                 // Add the SSL filter now since sockets are "borned" encrypted in the old ssl method
                 SSLContext sslContext = SSLContext.getInstance(algorithm);