1 files changed, 96 insertions, 0 deletions
diff --git a/gr-digital/lib/packet_sink_impl.h b/gr-digital/lib/packet_sink_impl.h
new file mode 100644
index 0000000000..a63db7a142
--- /dev/null
+++ b/gr-digital/lib/packet_sink_impl.h
@@ -0,0 +1,96 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2005,2012 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio 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.
+ *
+ * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_GR_PACKET_SINK_IMPL_H
+#define INCLUDED_GR_PACKET_SINK_IMPL_H
+
+#include <digital/packet_sink.h>
+
+namespace gr {
+  namespace digital {
+
+    class packet_sink_impl : public packet_sink
+    {
+    private:
+      enum state_t {STATE_SYNC_SEARCH, STATE_HAVE_SYNC, STATE_HAVE_HEADER};
+
+      static const int MAX_PKT_LEN    = 4096;
+      static const int HEADERBITLEN   = 32;
+
+      gr_msg_queue_sptr  d_target_queue;	// where to send the packet when received
+      unsigned long long d_sync_vector;		// access code to locate start of packet
+      unsigned int       d_threshold;		// how many bits may be wrong in sync vector
+      
+      state_t            d_state;
+
+      unsigned long long d_shift_reg;		// used to look for sync_vector
+
+      unsigned int       d_header;		// header bits
+      int		     d_headerbitlen_cnt;// how many so far
+
+      unsigned char      d_packet[MAX_PKT_LEN];	// assembled payload
+      unsigned char      d_packet_byte;         // byte being assembled
+      int                d_packet_byte_index;	// which bit of d_packet_byte we're working on
+      int                d_packetlen;		// length of packet
+      int                d_packetlen_cnt;	// how many so far
+
+    protected:
+      void enter_search();
+      void enter_have_sync();
+      void enter_have_header(int payload_len);
+
+      int slice(float x) { return x > 0 ? 1 : 0; }
+
+      bool header_ok()
+      {
+	// confirm that two copies of header info are identical
+	return ((d_header >> 16) ^ (d_header & 0xffff)) == 0;
+      }
+
+      int header_payload_len()
+      {
+	// header consists of two 16-bit shorts in network byte order
+	int t = (d_header >> 16) & 0xffff;
+	return t;
+      }
+
+    public:
+      packet_sink_impl(const std::vector<unsigned char>& sync_vector,
+		       gr_msg_queue_sptr target_queue,
+		       int threshold=-1);
+      ~packet_sink_impl();
+
+      int work(int noutput_items,
+	       gr_vector_const_void_star &input_items,
+	       gr_vector_void_star &output_items);
+
+      //! return true if we detect carrier
+      bool carrier_sensed() const
+      {
+	return d_state != STATE_SYNC_SEARCH;
+      }
+    };
+
+  } /* namespace digital */
+} /* namespace gr */
+
+#endif /* INCLUDED_GR_PACKET_SINK_IMPL_H */