Added uplink/downlink splitter
diff --git a/lib/uplink_downlink_filter_impl.cc b/lib/uplink_downlink_filter_impl.cc
new file mode 100644
index 0000000..b326fff
--- /dev/null
+++ b/lib/uplink_downlink_filter_impl.cc
@@ -0,0 +1,77 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Piotr Krysik <ptrkrysik@gmail.com>
+ * @section LICENSE
+ *
+ * Gr-gsm is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * Gr-gsm 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 gr-gsm; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gnuradio/io_signature.h>
+#include "uplink_downlink_filter_impl.h"
+#include <grgsm/gsmtap.h>
+#define BURST_SIZE 148
+namespace gr {
+ namespace grgsm {
+
+ uplink_downlink_filter::sptr
+ uplink_downlink_filter::make()
+ {
+ return gnuradio::get_initial_sptr
+ (new uplink_downlink_filter_impl());
+ }
+
+ /*
+ * The private constructor
+ */
+ uplink_downlink_filter_impl::uplink_downlink_filter_impl()
+ : gr::block("uplink_downlink_filter",
+ gr::io_signature::make(0,0,0),
+ gr::io_signature::make(0,0,0))
+ {
+ message_port_register_in(pmt::mp("in"));
+ message_port_register_out(pmt::mp("uplink"));
+ message_port_register_out(pmt::mp("downlink"));
+
+ set_msg_handler(pmt::mp("in"), boost::bind(&uplink_downlink_filter_impl::process_msg, this, _1));
+ }
+
+ void uplink_downlink_filter_impl::process_msg(pmt::pmt_t msg)
+ {
+ gsmtap_hdr * header = (gsmtap_hdr *)(pmt::blob_data(pmt::cdr(msg)));
+ bool uplink_burst = (be16toh(header->arfcn) & 0x4000) ? true : false;
+ if(uplink_burst)
+ {
+ message_port_pub(pmt::mp("uplink"), msg);
+ } else {
+ message_port_pub(pmt::mp("downlink"), msg);
+ }
+
+ }
+
+ /*
+ * Our virtual destructor.
+ */
+ uplink_downlink_filter_impl::~uplink_downlink_filter_impl()
+ {
+ }
+ } /* namespace grgsm */
+} /* namespace gr */
+