Implemented dummy burst filter. Issue #100
diff --git a/lib/flow_control/dummy_burst_filter_impl.cc b/lib/flow_control/dummy_burst_filter_impl.cc
new file mode 100644
index 0000000..33c24cb
--- /dev/null
+++ b/lib/flow_control/dummy_burst_filter_impl.cc
@@ -0,0 +1,105 @@
+/* -*- c++ -*- */
+/* @file
+ * @author Roman Khassraf <rkhassraf@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 "dummy_burst_filter_impl.h"
+#include <stdio.h>
+#include <grgsm/endian.h>
+#include <grgsm/gsmtap.h>
+
+
+namespace gr {
+ namespace gsm {
+
+ // dummy burst defined in gsm 05.02, section 5.2.6
+ const int8_t dummy_burst_filter_impl::d_dummy_burst[] = {0,0,0,
+ 1,1,1,1,1,0,1,1,0,1,1,1,0,1,1,0,
+ 0,0,0,0,1,0,1,0,0,1,0,0,1,1,1,0,
+ 0,0,0,0,1,0,0,1,0,0,0,1,0,0,0,0,
+ 0,0,0,1,1,1,1,1,0,0,0,1,1,1,0,0,
+ 0,1,0,1,1,1,0,0,0,1,0,1,1,1,0,0,
+ 0,1,0,1,0,1,1,1,0,1,0,0,1,0,1,0,
+ 0,0,1,1,0,0,1,1,0,0,1,1,1,0,0,1,
+ 1,1,1,0,1,0,0,1,1,1,1,1,0,0,0,1,
+ 0,0,1,0,1,1,1,1,1,0,1,0,1,0,
+ 0,0,0 };
+
+ dummy_burst_filter::sptr
+ dummy_burst_filter::make()
+ {
+ return gnuradio::get_initial_sptr
+ (new dummy_burst_filter_impl());
+ }
+
+ /*
+ * The private constructor
+ */
+ dummy_burst_filter_impl::dummy_burst_filter_impl()
+ : gr::block("dummy_burst_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("out"));
+
+ set_msg_handler(pmt::mp("in"), boost::bind(&dummy_burst_filter_impl::process_burst, this, _1));
+ }
+
+ /*
+ * Our virtual destructor.
+ */
+ dummy_burst_filter_impl::~dummy_burst_filter_impl() {}
+
+ void dummy_burst_filter_impl::process_burst(pmt::pmt_t msg)
+ {
+ pmt::pmt_t header_plus_burst = pmt::cdr(msg);
+ int8_t * burst = (int8_t *)(pmt::blob_data(header_plus_burst)) + sizeof(gsmtap_hdr);
+ size_t burst_len = pmt::blob_length(header_plus_burst) - sizeof(gsmtap_hdr);
+
+ if (!is_dummy_burst(burst, burst_len))
+ {
+ message_port_pub(pmt::mp("out"), msg);
+ }
+ }
+
+ bool dummy_burst_filter_impl::is_dummy_burst(int8_t *burst, size_t burst_len)
+ {
+ if (burst_len != DUMMY_BURST_LEN)
+ {
+ return false;
+ }
+ for (int i=0; i<DUMMY_BURST_LEN; i++)
+ {
+ if (burst[i] != d_dummy_burst[i])
+ {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ } /* namespace gsm */
+} /* namespace gr */