Add nomfreq, freqofs, dlt to PDU metadata

Add Nominal Frequency, Carrier Frequency Offset and Data Link Type (DLT)
tags to PDU.

Signed-off-by: Jonathan Brucker jonathan.brucke@gmail.com

lib/decode_mac.cc

@@ -24,6 +24,8 @@
 
 using namespace gr::ieee802_11;
 
+#define LINKTYPE_IEEE802_11 105 /* http://www.tcpdump.org/linktypes.html */
+
 class decode_mac_impl : public decode_mac {
 
 public:
@@ -34,6 +36,8 @@ decode_mac_impl(bool log, bool debug) :
 	d_log(log),
 	d_debug(debug),
 	d_snr(0),
+	d_nom_freq(0.0),
+	d_freq_offset(0.0),
 	d_ofdm(BPSK_1_2),
 	d_frame(d_ofdm, 0),
 	d_frame_complete(true) {
@@ -70,6 +74,8 @@ int general_work (int noutput_items, gr_vector_int& ninput_items,
 			int len_data = pmt::to_uint64(pmt::tuple_ref(tuple, 0));
 			int encoding = pmt::to_uint64(pmt::tuple_ref(tuple, 1));
 			d_snr = pmt::to_double(pmt::tuple_ref(tuple, 2));
+			d_nom_freq = pmt::to_double(pmt::tuple_ref(tuple, 3));
+			d_freq_offset = pmt::to_double(pmt::tuple_ref(tuple, 4));
 
 			ofdm_param ofdm = ofdm_param((Encoding)encoding);
 			frame_param frame = frame_param(ofdm, len_data);
@@ -141,6 +147,9 @@ void decode() {
 	pmt::pmt_t dict = pmt::make_dict();
 	dict = pmt::dict_add(dict, pmt::mp("encoding"), enc);
 	dict = pmt::dict_add(dict, pmt::mp("snr"), pmt::from_double(d_snr));
+	dict = pmt::dict_add(dict, pmt::mp("nomfreq"), pmt::from_double(d_nom_freq));
+	dict = pmt::dict_add(dict, pmt::mp("freqofs"), pmt::from_double(d_freq_offset));
+	dict = pmt::dict_add(dict, pmt::mp("dlt"), pmt::from_long(LINKTYPE_IEEE802_11));
 	message_port_pub(pmt::mp("out"), pmt::cons(dict, blob));
 }
 
@@ -218,7 +227,9 @@ private:
 
 	frame_param d_frame;
 	ofdm_param d_ofdm;
-	double d_snr;
+	double d_snr;  // dB
+	double d_nom_freq;  // nominal frequency, Hz
+	double d_freq_offset;  // frequency offset, Hz
 	viterbi_decoder d_decoder;
 
 	uint8_t d_rx_symbols[48 * MAX_SYM];