utils: draft implementation for queue drop tracer
diff --git a/utils/tracers/l2-tracer.cc b/utils/tracers/l2-tracer.cc
new file mode 100644
index 0000000..a3dc05b
--- /dev/null
+++ b/utils/tracers/l2-tracer.cc
@@ -0,0 +1,54 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author:  Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include "l2-tracer.h"
+#include "ns3/node.h"
+#include "ns3/config.h"
+#include "ns3/names.h"
+#include "ns3/callback.h"
+
+#include <boost/lexical_cast.hpp>
+
+using namespace std;
+
+namespace ns3 {
+
+L2Tracer::L2Tracer (Ptr<Node> node)
+: m_nodePtr (node)
+{
+  m_node = boost::lexical_cast<string> (m_nodePtr->GetId ());
+
+  Connect ();
+
+  string name = Names::FindName (node);
+  if (!name.empty ())
+    {
+      m_node = name;
+    }
+}
+
+void
+L2Tracer::Connect ()
+{
+  Config::ConnectWithoutContext ("/NodeList/"+m_node+"/DeviceList/*/TxQueue/Drop",
+                                 MakeCallback (&L2Tracer::Drop, this));
+}
+
+} // namespace ns3