AX.25 v2.2 connected mode.

modified:   CHANGES.md
	modified:   Makefile.linux
	modified:   Makefile.macosx
	modified:   Makefile.win
	modified:   README.md
	modified:   atest.c
	modified:   audio.h
	new file:   ax25_link.c
	new file:   ax25_link.h
	modified:   ax25_pad.c
	modified:   ax25_pad.h
	modified:   ax25_pad2.c
	new file:   cdigipeater.c
	new file:   cdigipeater.h
	modified:   config.c
	modified:   config.h
	modified:   digipeater.c
	modified:   direwolf.c
	modified:   direwolf.h
	modified:   dlq.c
	modified:   dlq.h
	modified:   doc/Going-beyond-9600-baud.pdf
	modified:   doc/Raspberry-Pi-APRS.pdf
	modified:   doc/Raspberry-Pi-SDR-IGate.pdf
	modified:   doc/User-Guide.pdf
	modified:   gen_packets.c
	modified:   hdlc_rec.c
	modified:   hdlc_send.c
	modified:   hdlc_send.h
	modified:   igate.c
	modified:   log.c
	modified:   log.h
	modified:   multi_modem.c
	modified:   pfilter.c
	modified:   pfilter.h
	modified:   ptt.c
	modified:   recv.c
	modified:   serial_port.c
	modified:   server.c
	modified:   server.h
	modified:   symbols-new.txt
	modified:   tocalls.txt
	modified:   tq.c
	modified:   tq.h
	modified:   waypoint.c
	modified:   xid.c
	new file:   xid.h
	modified:   xmit.c

CHANGES.md

@@ -1,6 +1,20 @@
 
 # Revision History #
 
+
+
+----------
+
+## Version 1.4  -- Development snapshot D --  November 2016 ##
+
+This is a snapshot at some semi-stable point in the development of the next version.  It is not well tested.  New features might be incomplete, poorly documented, and subject to change.
+
+
+### New Features: ###
+
+- AX.25 v2.2 connected mode.  See chapter 10 of User Guide for details.
+
+
 ----------
 
 ## Version 1.4  -- Development snapshot C --  June 2016 ##

Makefile.linux

@@ -230,12 +230,12 @@ z := $(notdir ${CURDIR})
 
 direwolf : direwolf.o config.o recv.o demod.o dsp.o demod_afsk.o demod_psk.o demod_9600.o hdlc_rec.o \
 		hdlc_rec2.o multi_modem.o rdq.o rrbb.o dlq.o \
-		fcs_calc.o ax25_pad.o \
+		fcs_calc.o ax25_pad.o  ax25_pad2.o xid.o \
 		decode_aprs.o symbols.o server.o kiss.o kissnet.o kiss_frame.o hdlc_send.o fcs_calc.o \
-		gen_tone.o audio.o audio_stats.o digipeater.o pfilter.o dedupe.o tq.o xmit.o morse.o \
+		gen_tone.o audio.o audio_stats.o digipeater.o cdigipeater.o pfilter.o dedupe.o tq.o xmit.o morse.o \
 		ptt.o beacon.o encode_aprs.o latlong.o encode_aprs.o latlong.o textcolor.o \
 		dtmf.o aprs_tt.o tt_user.o tt_text.o igate.o waypoint.o serial_port.o log.o telemetry.o \
-		dwgps.o dwgpsnmea.o dwgpsd.o dtime_now.o mheard.o \
+		dwgps.o dwgpsnmea.o dwgpsd.o dtime_now.o mheard.o ax25_link.o \
 		misc.a geotranz.a
 	$(CC) -o $@ $^ $(LDFLAGS)
 ifneq ($(enable_gpsd),)
@@ -588,7 +588,7 @@ install-rpi : dw-start.sh
 # Combine some unit tests into a single regression sanity check.
 
 
-check : dtest ttest tttexttest pftest tlmtest lltest enctest kisstest pad2test check-modem1200 check-modem300 check-modem9600 check-modem19200 check-modem2400 check-modem4800
+check : dtest ttest tttexttest pftest tlmtest lltest enctest kisstest pad2test xidtest check-modem1200 check-modem300 check-modem9600 check-modem19200 check-modem2400 check-modem4800
 
 # Can we encode and decode at popular data rates?
 
@@ -708,6 +708,15 @@ pad2test : ax25_pad2.c ax25_pad.c fcs_calc.o textcolor.o misc.a
 	rm pad2test
 
 
+# Unit Test for XID frame encode/decode.
+
+.PHONY: xidtest
+xidtest : xid.c textcolor.o misc.a
+	$(CC) $(CFLAGS) -DXIDTEST -o $@ $^  $(LDFLAGS)
+	./xidtest
+	rm xidtest
+
+
 
 #  -----------------------------  Manual tests and experiments  ---------------------------
 

Makefile.macosx

@@ -221,14 +221,14 @@ z := $(notdir ${CURDIR})
 
 # Main application.
 
-direwolf : direwolf.o aprs_tt.o audio_portaudio.o audio_stats.o ax25_pad.o beacon.o \
+direwolf : direwolf.o aprs_tt.o audio_portaudio.o audio_stats.o ax25_link.o ax25_pad.o  ax25_pad2.o beacon.o \
 		config.o decode_aprs.o dedupe.o demod_9600.o demod_afsk.o demod_psk.o \
-		demod.o digipeater.o dlq.o dsp.o dtime_now.o dtmf.o dwgps.o \
+		demod.o digipeater.o cdigipeater.o dlq.o dsp.o dtime_now.o dtmf.o dwgps.o \
 		encode_aprs.o encode_aprs.o fcs_calc.o fcs_calc.o gen_tone.o \
 		geotranz.a hdlc_rec.o hdlc_rec2.o hdlc_send.o igate.o kiss_frame.o \
 		kiss.o kissnet.o latlong.o latlong.o log.o morse.o multi_modem.o \
 		waypoint.o serial_port.o pfilter.o ptt.o rdq.o recv.o rrbb.o server.o \
-		symbols.o telemetry.o textcolor.o tq.o tt_text.o tt_user.o xmit.o \
+		symbols.o telemetry.o textcolor.o tq.o tt_text.o tt_user.o xid.o xmit.o \
 		dwgps.o dwgpsnmea.o mheard.o
 	$(CC) $(CFLAGS) -o $@ $^ -lpthread $(LDLIBS) -lm
 

Makefile.win

@@ -16,7 +16,7 @@
 #
 
 
-all : direwolf decode_aprs text2tt tt2text ll2utm utm2ll aclients log2gpx gen_packets atest ttcalc
+all : direwolf decode_aprs text2tt tt2text ll2utm utm2ll aclients log2gpx gen_packets atest ttcalc tnctest
 
 
 # People say we need -mthreads option for threads to work properly.
@@ -39,8 +39,6 @@ CFLAGS += -g
 #CFLAGS += -fsanitize=address -fno-omit-frame-pointer
 
 
-# TODO: Development in progress.  Don't try using yet.
-#CFLAGS += -DNEW14
 
 #
 # Let's see impact of various optimization levels.
@@ -86,16 +84,14 @@ demod_afsk.o : fsk_demod_state.h
 demod_psk.o  : fsk_demod_state.h
 
 
-# later ax25_link.o 
-
 direwolf : direwolf.o config.o recv.o demod.o dsp.o demod_afsk.o demod_psk.o demod_9600.o hdlc_rec.o \
 		hdlc_rec2.o multi_modem.o rdq.o rrbb.o dlq.o \
-		fcs_calc.o ax25_pad.o ax25_pad2.o \
+		fcs_calc.o ax25_pad.o ax25_pad2.o xid.o \
 		decode_aprs.o symbols.o server.o kiss.o kissnet.o kiss_frame.o hdlc_send.o fcs_calc.o \
-		gen_tone.o morse.o audio_win.o audio_stats.o digipeater.o pfilter.o dedupe.o tq.o xmit.o \
+		gen_tone.o morse.o audio_win.o audio_stats.o digipeater.o cdigipeater.o pfilter.o dedupe.o tq.o xmit.o \
 		ptt.o beacon.o dwgps.o encode_aprs.o latlong.o textcolor.o \
 		dtmf.o aprs_tt.o tt_user.o tt_text.o igate.o waypoint.o serial_port.o log.o telemetry.o \
-		dwgps.o dwgpsnmea.o dtime_now.o mheard.o \
+		dwgps.o dwgpsnmea.o dtime_now.o mheard.o ax25_link.o \
 		dw-icon.o regex.a misc.a geotranz.a
 	$(CC) $(CFLAGS) -o $@ $^ -lwinmm -lws2_32
 
@@ -260,7 +256,7 @@ strlcat.o : misc/strlcat.c
 # Combine some unit tests into a single regression sanity check.
 
 
-check : dtest ttest tttexttest pftest tlmtest lltest enctest kisstest pad2test check-modem1200 check-modem300 check-modem9600 check-modem19200 check-modem2400 check-modem4800
+check : dtest ttest tttexttest pftest tlmtest lltest enctest kisstest pad2test xidtest check-modem1200 check-modem300 check-modem9600 check-modem19200 check-modem2400 check-modem4800
 
 # Can we encode and decode at popular data rates?
 # Verify that single bit fixup increases the count.
@@ -317,6 +313,7 @@ atest : atest.c fsk_fast_filter.h demod.c demod_afsk.c demod_psk.c demod_9600.c
 		rrbb.o fcs_calc.o ax25_pad.o decode_aprs.o \
 		dwgpsnmea.o dwgps.o serial_port.o latlong.c \
 		symbols.c tt_text.c textcolor.c telemetry.c dtime_now.o \
+		decode_aprs.o log.o \
 		misc.a regex.a
 	echo " " > tune.h
 	$(CC) $(CFLAGS) -o $@ $^
@@ -412,10 +409,23 @@ pad2test : ax25_pad2.c ax25_pad.c fcs_calc.o textcolor.o regex.a misc.a
 	./pad2test
 	rm pad2test.exe
 
+# Unit Test for XID frame encode/decode.
+
+.PHONY: xidtest
+xidtest : xid.c textcolor.o misc.a
+	$(CC) $(CFLAGS) -DXIDTEST -o $@ $^
+	./xidtest
+	rm xidtest.exe
+
+
 
 # ------------------------------ Other manual testing & experimenting  -------------------------------
 
 
+tnctest : tnctest.c textcolor.o dtime_now.o serial_port.o misc.a
+	$(CC) $(CFLAGS) -o $@ $^ -lwinmm -lws2_32
+
+
 # For tweaking the demodulator.
 
 demod.o      : tune.h

README.md

@@ -42,6 +42,8 @@ Decodes more than 1000 error-free frames from [WA8LMF TNC Test CD](http://wa8lmf
 
 - Includes separate raw packet decoder, decode_aprs.
 
+- AX.25 v2.2 connected mode.  (New in version 1.4.)
+
 - Open source so you can see how it works and make your own modifications.
 
 - Runs in 3 different environments:
@@ -95,4 +97,4 @@ Here are some good places to share information:
 - [TAPR aprssig](http://www.tapr.org/pipermail/aprssig/)
  
 
-
+The github "issues" section is for reporting software defects and enhancement requests.  It is NOT a place to ask questions or have general discussions.  Please use one of the locations above.

atest.c

@@ -743,6 +743,24 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 	ax25_safe_print ((char *)pinfo, info_len, 0);
 	dw_printf ("\n");
 
+#if 1		// temp experiment  	TODO: remove this.
+
+#include "decode_aprs.h"
+#include "log.h"
+
+	if (ax25_is_aprs(pp)) {
+
+	  decode_aprs_t A;
+
+	  decode_aprs (&A, pp, 0);
+
+	  // Temp experiment to see how different systems set the RR bits in the source and destination.
+	  // log_rr_bits (&A, pp);
+
+	}
+#endif
+
+
 	ax25_delete (pp);
 
 } /* end fake dlq_append */

audio.h

@@ -89,6 +89,14 @@ struct audio_s {
 					/* statistics reports.  This is set by */
 					/* the "-a" option.  0 to disable feature. */
 
+	int xmit_error_rate;		/* For testing purposes, we can generate frames with an invalid CRC */
+					/* to simulate corruption while going over the air. */
+					/* This is the probability, in per cent, of randomly corrupting it. */
+					/* Normally this is 0.  25 would mean corrupt it 25% of the time. */
+
+	int recv_error_rate;		/* Similar but the % probablity of dropping a received frame. */
+
+
 	/* Properties for each audio channel, common to receive and transmit. */
 	/* Can be different for each radio channel. */
 
@@ -166,18 +174,20 @@ struct audio_s {
 	    int passall;		/* Allow thru even with bad CRC. */
 
 
+
 	/* Additional properties for transmit. */
 	
 	/* Originally we had control outputs only for PTT. */
 	/* In version 1.2, we generalize this to allow others such as DCD. */
+	/* In version 1.4 we add CON for connected to another station. */
 	/* Index following structure by one of these: */
 
 
 #define OCTYPE_PTT 0
 #define OCTYPE_DCD 1
-#define OCTYPE_FUTURE 2
+#define OCTYPE_CON 2
 
-#define NUM_OCTYPES 4		/* number of values above */
+#define NUM_OCTYPES 4		/* number of values above.   WHY IS THIS NOT 3? */
 	
 	    struct {  		
 

ax25_link.h

@@ -0,0 +1,82 @@
+
+/* ax25_link.h */
+
+
+#ifndef AX25_LINK_H
+#define AX25_LINK_H 1
+
+#include "ax25_pad.h"		// for AX25_MAX_INFO_LEN
+
+#include "dlq.h"		// for dlq_item_t
+
+#include "config.h"		// for struct misc_config_s
+
+
+
+// Limits and defaults for parameters.
+
+
+#define AX25_N1_PACLEN_MIN 1		// Max bytes in Information part of frame.
+#define AX25_N1_PACLEN_DEFAULT 256	// some v2.0 implementations have 128
+#define AX25_N1_PACLEN_MAX AX25_MAX_INFO_LEN	// from ax25_pad.h
+
+
+#define AX25_N2_RETRY_MIN 1		// Number of times to retry before giving up.
+#define AX25_N2_RETRY_DEFAULT 10
+#define AX25_N2_RETRY_MAX 15
+
+
+#define AX25_T1V_FRACK_MIN 1		// Number of seconds to wait before retrying.
+#define AX25_T1V_FRACK_DEFAULT 3	// KPC-3+ has 4.  TM-D710A has 3.
+#define AX25_T1V_FRACK_MAX 15
+
+
+#define AX25_K_MAXFRAME_BASIC_MIN 1		// Window size - number of I frames to send before waiting for ack.
+#define AX25_K_MAXFRAME_BASIC_DEFAULT 4
+#define AX25_K_MAXFRAME_BASIC_MAX 7
+
+#define AX25_K_MAXFRAME_EXTENDED_MIN 1
+#define AX25_K_MAXFRAME_EXTENDED_DEFAULT 32
+#define AX25_K_MAXFRAME_EXTENDED_MAX 63		// In theory 127 but I'm restricting as explained in SREJ handling.
+
+
+
+// Call once at startup time.
+
+void ax25_link_init (struct misc_config_s *pconfig);
+
+
+
+// IMPORTANT:
+
+// These functions must be called on a single thread, one at a time.
+// The Data Link Queue (DLQ) is used to serialize events from multiple sources.
+
+
+void dl_connect_request (dlq_item_t *E);
+
+void dl_disconnect_request (dlq_item_t *E);
+
+void dl_data_request (dlq_item_t *E);
+
+void dl_register_callsign (dlq_item_t *E);
+
+void dl_unregister_callsign (dlq_item_t *E);
+
+void dl_client_cleanup (dlq_item_t *E);
+
+
+void lm_data_indication (dlq_item_t *E);
+
+void lm_channel_busy (dlq_item_t *E);
+
+
+void dl_timer_expiry (void);
+
+
+double ax25_link_get_next_timer_expiry (void);
+
+
+#endif
+
+/* end ax25_link.h */

ax25_pad.c

@@ -24,6 +24,10 @@
  *
  * Purpose:	Packet assembler and disasembler.
  *
+ *		This was written when I was only concerned about APRS which
+ *		uses only UI frames.  ax25_pad2.c, added years later, has
+ *		functions for dealing with other types of frames.
+ *
  *   		We can obtain AX.25 packets from different sources:
  *		
  *		(a) from an HDLC frame.
@@ -77,11 +81,24 @@
  *			SSID = substation ID
  *			0 = zero
  *
+ *		The AX.25 spec states that the RR bits should be 11 if not used.
+ *		There are a couple documents talking about possible uses for APRS.
+ *		I'm ignoring them for now.
+ *		http://www.aprs.org/aprs12/preemptive-digipeating.txt
+ *		http://www.aprs.org/aprs12/RR-bits.txt
+ *
+ *		I don't recall why I originally intended to set the source/destination C bits both to 1.
+ *		Reviewing this 5 years later, after spending more time delving into the
+ *		AX.25 spec, I think it should be 1 for destination and 0 for source.
+ *		In practice you see all four combinations being used by APRS stations
+ *		and no one really cares about these two bits.
+ *
  *	The final octet of the Source has the form:
  *
  *		C R R SSID 0, where,
  *
- *			C = command/response = 1
+ *			C = command/response = 1    (originally, now I think it should be 0 for source.)
+ *						(Haven't gone back to check to see what code actually does.)
  *			R R = Reserved = 1 1
  *			SSID = substation ID
  *			0 = zero (or 1 if no repeaters)
@@ -165,8 +182,8 @@ char *strtok_r(char *str, const char *delim, char **saveptr);
 #endif
 
 
-#include "ax25_pad.h"
 #include "textcolor.h"
+#include "ax25_pad.h"
 #include "fcs_calc.h"
 
 /*
@@ -236,7 +253,13 @@ packet_t ax25_new (void)
 /*
  * check for memory leak.
  */
-	if (new_count > delete_count + 100) {
+
+// version 1.4 push up the threshold.   We could have considerably more with connected mode.
+
+	//if (new_count > delete_count + 100) {
+	if (new_count > delete_count + 256) {
+
+
 	  text_color_set(DW_COLOR_ERROR);
 	  dw_printf ("Report to WB2OSZ - Memory leak for packet objects.  new=%d, delete=%d\n", new_count, delete_count);
 #if AX25MEMDEBUG
@@ -434,7 +457,7 @@ packet_t ax25_from_text (char *monitor, int strict)
 	this_p->frame_data[AX25_SOURCE*7+6] = SSID_H_MASK | SSID_RR_MASK | SSID_LAST_MASK;
 
 	this_p->frame_data[14] = AX25_UI_FRAME;
-	this_p->frame_data[15] = AX25_NO_LAYER_3;
+	this_p->frame_data[15] = AX25_PID_NO_LAYER_3;
 
 	this_p->frame_len = 7 + 7 + 1 + 1;
 	this_p->num_addr = (-1);
@@ -1517,6 +1540,39 @@ int ax25_get_first_not_repeated(packet_t this_p)
 }
 
 
+/*------------------------------------------------------------------------------
+ *
+ * Name:	ax25_get_rr
+ *
+ * Purpose:	Return the two reserved "RR" bits in the specified address field.
+ *
+ * Inputs:	pp	- Packet object.
+ *
+ *		n	- Index of address.   Use the symbols
+ *			  AX25_DESTINATION, AX25_SOURCE, AX25_REPEATER1, etc.
+ *
+ * Returns:	0, 1, 2, or 3.
+ *
+ *------------------------------------------------------------------------------*/
+
+int ax25_get_rr (packet_t this_p, int n)
+{
+
+	assert (this_p->magic1 == MAGIC);
+	assert (this_p->magic2 == MAGIC);
+	assert (n >= 0 && n < this_p->num_addr);
+
+	if (n >= 0 && n < this_p->num_addr) {
+	  return ((this_p->frame_data[n*7+6] & SSID_RR_MASK) >> SSID_RR_SHIFT);
+	}
+	else {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("Internal error: ax25_get_rr(%d), num_addr=%d\n", n, this_p->num_addr);
+	  return (0);
+	}
+}
+
+
 /*------------------------------------------------------------------------------
  *
  * Name:	ax25_get_info
@@ -1678,6 +1734,25 @@ double ax25_get_release_time (packet_t this_p)
 }
 
 
+/*------------------------------------------------------------------------------
+ *
+ * Name:	ax25_set_modulo
+ *
+ * Purpose:	Set modulo value for I and S frame sequence numbers.
+ *
+ *------------------------------------------------------------------------------*/
+
+void ax25_set_modulo (packet_t this_p, int modulo)
+{
+	assert (this_p->magic1 == MAGIC);
+	assert (this_p->magic2 == MAGIC);
+
+	this_p->modulo = modulo;
+}
+
+
+
+
 
 /*------------------------------------------------------------------
  *
@@ -1793,12 +1868,9 @@ int ax25_pack (packet_t this_p, unsigned char result[AX25_MAX_PACKET_LEN])
  *
  * Inputs:	this_p	- pointer to packet object.
  *		
- * 		modulo	- We often need to know this because context is		// TODO: remove this - return cr instead.
- *			  required to know if control is 1 or 2 bytes.
- *
  * Outputs:	desc	- Text description such as "I frame" or
  *			  "U frame SABME".   
- *			  Supply 16 bytes to be safe.
+ *			  Supply 40 bytes to be safe.
  *
  *		cr	- Command or response?
  *
@@ -1813,13 +1885,14 @@ int ax25_pack (packet_t this_p, unsigned char result[AX25_MAX_PACKET_LEN])
  *------------------------------------------------------------------*/
 
 // TODO: need someway to ensure caller allocated enough space.
-#define DESC_SIZ 32
+// Should pass in as parameter.
+#define DESC_SIZ 40
 
 
 ax25_frame_type_t ax25_frame_type (packet_t this_p, cmdres_t *cr, char *desc, int *pf, int *nr, int *ns) 
 {
 	int c;		// U frames are always one control byte.
-	int c2;		// I & S frames can have second Control byte.
+	int c2 = 0;	// I & S frames can have second Control byte.
 
 	assert (this_p->magic1 == MAGIC);
 	assert (this_p->magic2 == MAGIC);
@@ -1835,6 +1908,41 @@ ax25_frame_type_t ax25_frame_type (packet_t this_p, cmdres_t *cr, char *desc, in
 	  strlcpy (desc, "Not AX.25", DESC_SIZ);
 	  return (frame_not_AX25);
 	}
+
+/*
+ * TERRIBLE HACK :-(  for display purposes.
+ *
+ * I and S frames can have 1 or 2 control bytes but there is
+ * no good way to determine this without dipping into the data
+ * link state machine.  Can we guess?
+ *
+ * S frames have no protocol id or information so if there is one
+ * more byte beyond the control field, we could assume there are
+ * two control bytes.
+ *
+ * For I frames, the protocol id will usually be 0xf0.  If we find
+ * that as the first byte of the information field, it is probably
+ * the pid and not part of the information.  Ditto for segments 0x08.
+ * Not fool proof but good enough for troubleshooting text out.
+ *
+ * If we have a link to the peer station, this will be set properly
+ * before it needs to be used for other reasons.
+ *
+ * Setting one of the RR bits (find reference!) is sounding better and better.
+ * It's in common usage so I should lobby to get that in the official protocol spec.
+ */
+
+	if (this_p->modulo == 0 && (c & 3) == 1 && ax25_get_c2(this_p) != -1) {
+	  this_p->modulo = modulo_128;
+	}
+	else if (this_p->modulo == 0 && (c & 1) == 0 && this_p->frame_data[ax25_get_info_offset(this_p)] == 0xF0) {
+	  this_p->modulo = modulo_128;
+	}
+	else if (this_p->modulo == 0 && (c & 1) == 0 && this_p->frame_data[ax25_get_info_offset(this_p)] == 0x08) {	// same for segments
+	  this_p->modulo = modulo_128;
+	}
+
+
 	if (this_p->modulo == modulo_128) {
 	  c2 = ax25_get_c2 (this_p);
 	}
@@ -1868,7 +1976,9 @@ ax25_frame_type_t ax25_frame_type (packet_t this_p, cmdres_t *cr, char *desc, in
 	    *pf = (c >> 4) & 1;
 	    *nr = (c >> 5) & 7;
 	  }
-	  snprintf (desc, DESC_SIZ, "I %s, n(s)= %d, n(r)=%d, %s=%d", cr_text, *ns, *nr, pf_text, *pf);
+
+	  //snprintf (desc, DESC_SIZ, "I %s, n(s)=%d, n(r)=%d, %s=%d", cr_text, *ns, *nr, pf_text, *pf);
+	  snprintf (desc, DESC_SIZ, "I %s, n(s)=%d, n(r)=%d, %s=%d, pid=0x%02x", cr_text, *ns, *nr, pf_text, *pf, ax25_get_pid(this_p));
 	  return (frame_type_I);
 	}
 	else if ((c & 2) == 0) {
@@ -1960,6 +2070,7 @@ static void hex_dump (unsigned char *p, int len)
 }
 
 /* Text description of control octet. */
+// FIXME:  this is wrong.  It doesn't handle modulo 128.
 
 // TODO: use ax25_frame_type() instead.
 
@@ -2108,10 +2219,12 @@ int ax25_is_aprs (packet_t this_p)
 	assert (this_p->magic1 == MAGIC);
 	assert (this_p->magic2 == MAGIC);
 
+	if (this_p->frame_len == 0) return(0);
+
 	ctrl = ax25_get_control(this_p);
 	pid = ax25_get_pid(this_p);
 
-	is_aprs = this_p->num_addr >= 2 && ctrl == AX25_UI_FRAME && pid == AX25_NO_LAYER_3;
+	is_aprs = this_p->num_addr >= 2 && ctrl == AX25_UI_FRAME && pid == AX25_PID_NO_LAYER_3;
 
 #if 0 
         text_color_set(DW_COLOR_ERROR);
@@ -2120,6 +2233,41 @@ int ax25_is_aprs (packet_t this_p)
 	return (is_aprs);
 }
 
+
+/*------------------------------------------------------------------
+ *
+ * Function:	ax25_is_null_frame
+ *
+ * Purpose:	Is this packet structure empty?
+ *
+ * Inputs:	this_p	- pointer to packet object.
+ *
+ * Returns:	True if frame data length is 0.
+ *
+ * Description:	This is used when we want to wake up the
+ *		transmit queue processing thread but don't
+ *		want to transmit a frame.
+ *
+ *------------------------------------------------------------------*/
+
+
+int ax25_is_null_frame (packet_t this_p)
+{
+	int is_null;
+
+	assert (this_p->magic1 == MAGIC);
+	assert (this_p->magic2 == MAGIC);
+
+	is_null = this_p->frame_len == 0;
+
+#if 0
+        text_color_set(DW_COLOR_ERROR);
+        dw_printf ("ax25_is_null_frame(): is_null=%d\n", is_null);
+#endif
+	return (is_null);
+}
+
+
 /*------------------------------------------------------------------
  *
  * Function:	ax25_get_control
@@ -2140,6 +2288,8 @@ int ax25_get_control (packet_t this_p)
 	assert (this_p->magic1 == MAGIC);
 	assert (this_p->magic2 == MAGIC);
 
+	if (this_p->frame_len == 0) return(-1);
+
 	if (this_p->num_addr >= 2) {
 	  return (this_p->frame_data[ax25_get_control_offset(this_p)]);
 	}
@@ -2151,10 +2301,19 @@ int ax25_get_c2 (packet_t this_p)
 	assert (this_p->magic1 == MAGIC);
 	assert (this_p->magic2 == MAGIC);
 
+	if (this_p->frame_len == 0) return(-1);
+
 	if (this_p->num_addr >= 2) {
-	  return (this_p->frame_data[ax25_get_control_offset(this_p)+1]);
+	  int offset2 = ax25_get_control_offset(this_p)+1;
+
+	  if (offset2 < this_p->frame_len) {
+	    return (this_p->frame_data[offset2]);
+	  }
+	  else {
+	    return (-1);	/* attempt to go beyond the end of frame. */
+	  }
 	}
-	return (-1);
+	return (-1);		/* not AX.25 */
 }
 
 
@@ -2184,6 +2343,8 @@ int ax25_get_pid (packet_t this_p)
 	// TODO: handle 2 control byte case.
 	// TODO: sanity check: is it I or UI frame?
 
+	if (this_p->frame_len == 0) return(-1);
+
 	if (this_p->num_addr >= 2) {
 	  return (this_p->frame_data[ax25_get_pid_offset(this_p)]);
 	}
@@ -2372,7 +2533,8 @@ void ax25_safe_print (char *pstr, int len, int ascii_only)
 	if (len > MAXSAFE)
 	  len = MAXSAFE;
 
-	while (len > 0 && *pstr != '\0')
+	//while (len > 0 && *pstr != '\0')
+	while (len > 0)
 	{
 	  ch = *((unsigned char *)pstr);
 

ax25_pad.h

@@ -64,8 +64,10 @@
  */
 
 #define AX25_UI_FRAME 3		/* Control field value. */
-#define AX25_NO_LAYER_3 0xf0	/* protocol ID */
 
+#define AX25_PID_NO_LAYER_3 0xf0		/* protocol ID used for APRS */
+#define AX25_PID_SEGMENTATION_FRAGMENT 0x08
+#define AX25_PID_ESCAPE_CHARACTER 0xff
 
 
 #ifdef AX25_PAD_C	/* Keep this hidden - implementation could change. */
@@ -159,9 +161,11 @@ typedef struct packet_s *packet_t;
 typedef enum cmdres_e { cr_00 = 2, cr_cmd = 1, cr_res = 0, cr_11 = 3 } cmdres_t;
 
 
+extern packet_t ax25_new (void);
+
+
 #ifdef AX25_PAD_C	/* Keep this hidden - implementation could change. */
 
-extern packet_t ax25_new (void);
 
 /*
  * APRS always has one control octet of 0x03 but the more
@@ -169,6 +173,8 @@ extern packet_t ax25_new (void);
  * whether "modulo 128 operation" is in effect.
  */
 
+//#define DEBUGX 1
+
 static inline int ax25_get_control_offset (packet_t this_p) 
 {
 	return (this_p->num_addr*7);
@@ -176,7 +182,29 @@ static inline int ax25_get_control_offset (packet_t this_p)
 
 static inline int ax25_get_num_control (packet_t this_p)
 {
-	return (this_p->modulo == 128 ? 2 : 1);
+	int c;
+
+	c = this_p->frame_data[ax25_get_control_offset(this_p)];
+
+	if ( (c & 0x01) == 0 ) {			/* I   xxxx xxx0 */
+#if DEBUGX
+	  dw_printf ("ax25_get_num_control, %02x is I frame, returns %d\n", c, (this_p->modulo == 128) ? 2 : 1);
+#endif
+	  return ((this_p->modulo == 128) ? 2 : 1);
+	}
+
+	if ( (c & 0x03) == 1 ) {			/* S   xxxx xx01 */
+#if DEBUGX
+	  dw_printf ("ax25_get_num_control, %02x is S frame, returns %d\n", c, (this_p->modulo == 128) ? 2 : 1);
+#endif
+	  return ((this_p->modulo == 128) ? 2 : 1);
+	}
+
+#if DEBUGX
+	dw_printf ("ax25_get_num_control, %02x is U frame, always returns 1.\n", c);
+#endif
+
+	return (1);					/* U   xxxx xx11 */
 }
 
 
@@ -202,11 +230,17 @@ static int ax25_get_num_pid (packet_t this_p)
 	     c == 0x03 || c == 0x13) {			/* UI  000x 0011 */
 
 	  pid = this_p->frame_data[ax25_get_pid_offset(this_p)];
-	  if (pid == 0xff) {
+#if DEBUGX
+	  dw_printf ("ax25_get_num_pid, %02x is I or UI frame, pid = %02x, returns %d\n", c, pid, (pid==AX25_PID_ESCAPE_CHARACTER) ? 2 : 1);
+#endif
+	  if (pid == AX25_PID_ESCAPE_CHARACTER) {
 	    return (2);			/* pid 1111 1111 means another follows. */
 	  }
 	  return (1);		
 	}
+#if DEBUGX
+	dw_printf ("ax25_get_num_pid, %02x is neither I nor UI frame, returns 0\n", c);
+#endif
 	return (0);
 }
 
@@ -225,7 +259,11 @@ static int ax25_get_num_pid (packet_t this_p)
 
 static inline int ax25_get_info_offset (packet_t this_p) 
 {
-	return (ax25_get_control_offset (this_p) + ax25_get_num_control(this_p) + ax25_get_num_pid(this_p));
+	int offset = ax25_get_control_offset (this_p) + ax25_get_num_control(this_p) + ax25_get_num_pid(this_p);
+#if DEBUGX
+	dw_printf ("ax25_get_info_offset, returns %d\n", offset);
+#endif
+	return (offset);
 }
 
 static inline int ax25_get_num_info (packet_t this_p)
@@ -249,7 +287,7 @@ typedef enum ax25_modulo_e { modulo_8 = 8, modulo_128 = 128 } ax25_modulo_t;
 
 typedef enum ax25_frame_type_e {
 
-	frame_type_I,		// Information
+	frame_type_I = 0,	// Information
 
 	frame_type_S_RR,	// Receive Ready - System Ready To Receive
 	frame_type_S_RNR,	// Receive Not Ready - TNC Buffer Full
@@ -268,6 +306,8 @@ typedef enum ax25_frame_type_e {
 	frame_type_U,		// other Unnumbered, not used by AX.25.
 
 	frame_not_AX25		// Could not get control byte from frame.
+				// This must be last because value plus 1 is
+				// for the size of an array.
 
 } ax25_frame_type_t;
 	
@@ -354,6 +394,8 @@ extern int ax25_get_heard(packet_t this_p);
 
 extern int ax25_get_first_not_repeated(packet_t pp);
 
+extern int ax25_get_rr (packet_t this_p, int n);
+
 extern int ax25_get_info (packet_t pp, unsigned char **paddr);
 
 extern void ax25_set_nextp (packet_t this_p, packet_t next_p);
@@ -365,6 +407,8 @@ extern packet_t ax25_get_nextp (packet_t this_p);
 extern void ax25_set_release_time (packet_t this_p, double release_time);
 extern double ax25_get_release_time (packet_t this_p);
 
+extern void ax25_set_modulo (packet_t this_p, int modulo);
+
 extern void ax25_format_addrs (packet_t pp, char *);
 
 extern int ax25_pack (packet_t pp, unsigned char result[AX25_MAX_PACKET_LEN]);
@@ -374,6 +418,7 @@ extern ax25_frame_type_t ax25_frame_type (packet_t this_p, cmdres_t *cr, char *d
 extern void ax25_hex_dump (packet_t this_p);
 
 extern int ax25_is_aprs (packet_t pp);
+extern int ax25_is_null_frame (packet_t this_p);
 
 extern int ax25_get_control (packet_t this_p); 
 extern int ax25_get_c2 (packet_t this_p); 

ax25_pad2.c

@@ -254,7 +254,7 @@ packet_t ax25_u_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 	if (t != 2) {
 	  if (cr != t) {
 	    text_color_set(DW_COLOR_ERROR);
-	    dw_printf ("Internal error in %s: U frame, cr is %d but must be %d.\n", __func__, cr, t);
+	    dw_printf ("Internal error in %s: U frame, cr is %d but must be %d. ftype=%d\n", __func__, cr, t, ftype);
 	  }
 	}
 
@@ -270,7 +270,7 @@ packet_t ax25_u_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 	  if (pid < 0 || pid == 0 || pid == 0xff) {
 	    text_color_set(DW_COLOR_ERROR);
 	    dw_printf ("Internal error in %s: U frame, Invalid pid value 0x%02x.\n", __func__, pid);
-	    pid = AX25_NO_LAYER_3;
+	    pid = AX25_PID_NO_LAYER_3;
 	  }
 	  *p++ = pid;
 	  this_p->frame_len++;
@@ -303,7 +303,7 @@ packet_t ax25_u_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 #if PAD2TEST
 	ax25_frame_type_t check_ftype;
 	cmdres_t check_cr;
-	char check_desc[32];
+	char check_desc[80];
 	int check_pf;
 	int check_nr;
 	int check_ns;
@@ -444,7 +444,7 @@ packet_t ax25_s_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 
 	ax25_frame_type_t check_ftype;
 	cmdres_t check_cr;
-	char check_desc[32];
+	char check_desc[80];
 	int check_pf;
 	int check_nr;
 	int check_ns;
@@ -573,9 +573,9 @@ packet_t ax25_i_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 	// or 0xff (which means more bytes follow).
 
 	if (pid < 0 || pid == 0 || pid == 0xff) {
-	  text_color_set(DW_COLOR_ERROR);
-	  dw_printf ("Internal error in %s: I frame, Invalid pid value 0x%02x.\n", __func__, pid);
-	  pid = AX25_NO_LAYER_3;
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("Warning: Client application provided invalid PID value, 0x%02x, for I frame.\n", pid);
+	  pid = AX25_PID_NO_LAYER_3;
 	}
 	*p++ = pid;
 	this_p->frame_len++;
@@ -601,7 +601,7 @@ packet_t ax25_i_frame (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_ad
 
 	ax25_frame_type_t check_ftype;
 	cmdres_t check_cr;
-	char check_desc[32];
+	char check_desc[80];
 	int check_pf;
 	int check_nr;
 	int check_ns;

cdigipeater.c

@@ -0,0 +1,325 @@
+//
+//    This file is part of Dire Wolf, an amateur radio packet TNC.
+//
+//    Copyright (C) 2016  John Langner, WB2OSZ
+//
+//    This program 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 2 of the License, or
+//    (at your option) any later version.
+//
+//    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, see <http://www.gnu.org/licenses/>.
+//
+
+
+/*------------------------------------------------------------------
+ *
+ * Name:	cdigipeater.c
+ *
+ * Purpose:	Act as an digital repeater for connected AX.25 mode.
+ *		Similar digipeater.c is for APRS.
+ *
+ *
+ * Description:	Decide whether the specified packet should
+ *		be digipeated.  Put my callsign in the digipeater field used.
+ *
+ *		APRS and connected mode were two split into two
+ *		separate files.  Yes, there is duplicate code but they
+ *		are significantly different and I thought it would be
+ *		too confusing to munge them together.
+ *
+ * References:	The Ax.25 protcol barely mentions digipeaters and
+ *		and doesn't describe how they should work.
+ *		
+ *------------------------------------------------------------------*/
+
+#define CDIGIPEATER_C
+
+#include "direwolf.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <ctype.h>	/* for isdigit, isupper */
+#include "regex.h"
+#include <sys/unistd.h>
+
+#include "ax25_pad.h"
+#include "cdigipeater.h"
+#include "textcolor.h"
+#include "tq.h"
+#include "pfilter.h"
+
+
+static packet_t cdigipeat_match (int from_chan, packet_t pp, char *mycall_rec, char *mycall_xmit, 
+				regex_t *alias, int to_chan, char *filter_str);
+
+
+/*
+ * Keep pointer to configuration options.
+ * Set by cdigipeater_init and used later.
+ */
+
+
+static struct audio_s	    *save_audio_config_p;
+static struct cdigi_config_s *save_cdigi_config_p;
+
+
+/*
+ * Maintain count of packets digipeated for each combination of from/to channel.
+ */
+
+static int cdigi_count[MAX_CHANS][MAX_CHANS];
+
+int cdigipeater_get_count (int from_chan, int to_chan) {
+	return (cdigi_count[from_chan][to_chan]);
+}
+
+
+
+/*------------------------------------------------------------------------------
+ *
+ * Name:	cdigipeater_init
+ * 
+ * Purpose:	Initialize with stuff from configuration file.
+ *
+ * Inputs:	p_audio_config	- Configuration for audio channels.
+ *
+ *		p_cdigi_config	- Connected Digipeater configuration details.
+ *		
+ * Outputs:	Save pointers to configuration for later use.
+ *		
+ * Description:	Called once at application startup time.
+ *
+ *------------------------------------------------------------------------------*/
+
+void cdigipeater_init (struct audio_s *p_audio_config, struct cdigi_config_s *p_cdigi_config) 
+{
+	save_audio_config_p = p_audio_config;
+	save_cdigi_config_p = p_cdigi_config;
+}
+
+
+
+
+/*------------------------------------------------------------------------------
+ *
+ * Name:	cdigipeater
+ * 
+ * Purpose:	Re-transmit packet if it matches the rules.
+ *
+ * Inputs:	chan	- Radio channel where it was received.
+ *		
+ * 		pp	- Packet object.
+ *		
+ * Returns:	None.
+ *		
+ *------------------------------------------------------------------------------*/
+
+
+
+void cdigipeater (int from_chan, packet_t pp)
+{
+	int to_chan;
+
+
+	if ( from_chan < 0 || from_chan >= MAX_CHANS || ( ! save_audio_config_p->achan[from_chan].valid) ) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("cdigipeater: Did not expect to receive on invalid channel %d.\n", from_chan);
+	  return;
+	}
+
+/*
+ * First pass:  Look at packets being digipeated to same channel.
+ *
+ * There was a reason for two passes for APRS.
+ * Might not have a benefit here.
+ */
+
+	for (to_chan=0; to_chan<MAX_CHANS; to_chan++) {
+	  if (save_cdigi_config_p->enabled[from_chan][to_chan]) {
+	    if (to_chan == from_chan) {
+	      packet_t result;
+
+	      result = cdigipeat_match (from_chan, pp, save_audio_config_p->achan[from_chan].mycall, 
+					   save_audio_config_p->achan[to_chan].mycall, 
+			&save_cdigi_config_p->alias[from_chan][to_chan], to_chan,
+				save_cdigi_config_p->filter_str[from_chan][to_chan]);
+	      if (result != NULL) {
+	        tq_append (to_chan, TQ_PRIO_0_HI, result);
+	        cdigi_count[from_chan][to_chan]++;
+	      }
+	    }
+	  }
+	}
+
+
+/*
+ * Second pass:  Look at packets being digipeated to different channel.
+ */
+
+	for (to_chan=0; to_chan<MAX_CHANS; to_chan++) {
+	  if (save_cdigi_config_p->enabled[from_chan][to_chan]) {
+	    if (to_chan != from_chan) {
+	      packet_t result;
+
+	      result = cdigipeat_match (from_chan, pp, save_audio_config_p->achan[from_chan].mycall, 
+					   save_audio_config_p->achan[to_chan].mycall, 
+			&save_cdigi_config_p->alias[from_chan][to_chan], to_chan,
+				save_cdigi_config_p->filter_str[from_chan][to_chan]);
+	      if (result != NULL) {
+	        tq_append (to_chan, TQ_PRIO_0_HI, result);
+	        cdigi_count[from_chan][to_chan]++;
+	      }
+	    }
+	  }
+	}
+
+} /* end cdigipeater */
+
+
+
+/*------------------------------------------------------------------------------
+ *
+ * Name:	cdigipeat_match
+ * 
+ * Purpose:	A simple digipeater for connected mode AX.25.
+ *
+ * Input:	pp		- Pointer to a packet object.
+ *	
+ *		mycall_rec	- Call of my station, with optional SSID,
+ *				  associated with the radio channel where the 
+ *				  packet was received.
+ *
+ *		mycall_xmit	- Call of my station, with optional SSID,
+ *				  associated with the radio channel where the 
+ *				  packet is to be transmitted.  Could be the same as
+ *				  mycall_rec or different.
+ *
+ *		alias		- Compiled pattern for my station aliases.
+ *				  Could be NULL if no aliases.
+ *
+ *		to_chan		- Channel number that we are transmitting to.
+ *
+ *		filter_str	- Filter expression string or NULL.
+ *		
+ * Returns:	Packet object for transmission or NULL.
+ *		The original packet is not modified.  The caller is responsible for freeing it.
+ *		We make a copy and return that modified copy!
+ *		This is very important because we could digipeat from one channel to many.
+ *
+ * Description:	The packet will be digipeated if the next unused digipeater
+ *		field matches one of the following:
+ *
+ *			- mycall_rec
+ *			- alias list
+ *
+ *		APRS digipeating drops duplicates within 30 seconds but we don't do that here.
+ *
+ *------------------------------------------------------------------------------*/
+
+
+static packet_t cdigipeat_match (int from_chan, packet_t pp, char *mycall_rec, char *mycall_xmit, 
+				regex_t *alias, int to_chan, char *filter_str)
+{
+	int r;
+	char repeater[AX25_MAX_ADDR_LEN];
+	int err;
+	char err_msg[100];
+
+/*
+ * First check if filtering has been configured.
+ */
+
+	if (filter_str != NULL) {
+
+	  if (pfilter(from_chan, to_chan, filter_str, pp, 0) != 1) {
+
+// Take out debug message?
+// Actually it turns out to be useful.
+// Maybe add a quiet option to suppress it.
+//#if DEBUG
+	    text_color_set(DW_COLOR_INFO);
+	    dw_printf ("Packet was rejected for digipeating from channel %d to %d by cfilter: %s\n", from_chan, to_chan, filter_str);
+//#endif
+	    return(NULL);
+	  }
+	}
+
+
+/* 
+ * Find the first repeater station which doesn't have "has been repeated" set.
+ *
+ * r = index of the address position in the frame.
+ */
+	r = ax25_get_first_not_repeated(pp);
+
+	if (r < AX25_REPEATER_1) {
+	  return (NULL);		// Nothing to do.
+	}
+
+	ax25_get_addr_with_ssid(pp, r, repeater);
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("First unused digipeater is %s\n", repeater);
+#endif
+
+
+/*
+ * First check for explicit use of my call.
+ * Note that receive and transmit channels could have different callsigns.
+ */
+	
+	if (strcmp(repeater, mycall_rec) == 0) {
+	  packet_t result;
+
+	  result = ax25_dup (pp);
+	  assert (result != NULL);
+
+	  /* If using multiple radio channels, they could have different calls. */
+
+	  ax25_set_addr (result, r, mycall_xmit);	
+	  ax25_set_h (result, r);
+	  return (result);
+	}
+
+/*
+ * If we have an alias match, substitute MYCALL.
+ */
+	if (alias != NULL) {
+	  err = regexec(alias,repeater,0,NULL,0);
+	  if (err == 0) {
+	    packet_t result;
+
+	    result = ax25_dup (pp);
+	    assert (result != NULL);
+
+	    ax25_set_addr (result, r, mycall_xmit);	
+	    ax25_set_h (result, r);
+	    return (result);
+	  }
+	  else if (err != REG_NOMATCH) {
+	    regerror(err, alias, err_msg, sizeof(err_msg));
+	    text_color_set (DW_COLOR_ERROR);
+	    dw_printf ("%s\n", err_msg);
+	  }
+	}
+
+/*
+ * Don't repeat it if we get here.
+ */
+	return (NULL);
+
+} /* end cdigipeat_match */
+
+
+
+/* end cdigipeater.c */

cdigipeater.h

@@ -0,0 +1,59 @@
+
+
+#ifndef CDIGIPEATER_H
+#define CDIGIPEATER_H 1
+
+#include "regex.h"
+
+#include "direwolf.h"		/* for MAX_CHANS */
+#include "ax25_pad.h"		/* for packet_t */
+#include "audio.h"		/* for radio channel properties */
+
+
+/*
+ * Information required for Connected mode digipeating.
+ *
+ * The configuration file reader fills in this information
+ * and it is passed to cdigipeater_init at application start up time.
+ */
+
+
+struct cdigi_config_s {
+
+/*
+ * Rules for each of the [from_chan][to_chan] combinations.
+ */
+
+	regex_t	alias[MAX_CHANS][MAX_CHANS];
+
+	int	enabled[MAX_CHANS][MAX_CHANS];
+
+	char *filter_str[MAX_CHANS+1][MAX_CHANS+1];
+						// NULL or optional Packet Filter strings such as "t/m".
+						// Notice the size of arrays is one larger than normal.
+						// That extra position is for the IGate.
+};
+
+/*
+ * Call once at application start up time.
+ */
+
+extern void cdigipeater_init (struct audio_s *p_audio_config, struct cdigi_config_s *p_cdigi_config);
+
+/*
+ * Call this for each packet received.
+ * Suitable packets will be queued for transmission.
+ */
+
+extern void cdigipeater (int from_chan, packet_t pp);
+
+
+/* Make statistics available. */
+
+int cdigipeater_get_count (int from_chan, int to_chan);
+
+
+#endif 
+
+/* end cdigipeater.h */
+

config.c

@@ -53,6 +53,7 @@
 #include "textcolor.h"
 #include "audio.h"
 #include "digipeater.h"
+#include "cdigipeater.h"
 #include "config.h"
 #include "aprs_tt.h"
 #include "igate.h"
@@ -60,6 +61,7 @@
 #include "symbols.h"
 #include "xmit.h"
 #include "tt_text.h"
+#include "ax25_link.h"
 
 // geotranz
 
@@ -680,7 +682,9 @@ static char *split (char *string, int rest_of_line)
  *
  * Outputs:	p_audio_config		- Radio channel parameters stored here.
  *
- *		p_digi_config	- Digipeater configuration stored here.
+ *		p_digi_config	- APRS Digipeater configuration stored here.
+ *
+ *		p_cdigi_config	- Connected Digipeater configuration stored here.
  *
  *		p_tt_config	- APRStt stuff.
  *
@@ -703,6 +707,7 @@ static char *split (char *string, int rest_of_line)
 
 void config_init (char *fname, struct audio_s *p_audio_config, 
 			struct digi_config_s *p_digi_config,
+			struct cdigi_config_s *p_cdigi_config,
 			struct tt_config_s *p_tt_config,
 			struct igate_config_s *p_igate_config,
 			struct misc_config_s *p_misc_config)
@@ -789,6 +794,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 	memset (p_digi_config, 0, sizeof(struct digi_config_s));
 	p_digi_config->dedupe_time = DEFAULT_DEDUPE;
+	memset (p_cdigi_config, 0, sizeof(struct cdigi_config_s));
 
 	memset (p_tt_config, 0, sizeof(struct tt_config_s));	
 	p_tt_config->gateway_enabled = 0;
@@ -865,6 +871,19 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 	strlcpy (p_misc_config->logdir, "", sizeof(p_misc_config->logdir));
 
+	/* connected mode. */
+
+	p_misc_config->frack = AX25_T1V_FRACK_DEFAULT;		/* Number of seconds to wait for ack to transmission. */
+
+	p_misc_config->retry = AX25_N2_RETRY_DEFAULT;		/* Number of times to retry before giving up. */
+
+	p_misc_config->paclen = AX25_N1_PACLEN_DEFAULT;		/* Max number of bytes in information part of frame. */
+
+	p_misc_config->maxframe_basic = AX25_K_MAXFRAME_BASIC_DEFAULT;	/* Max frames to send before ACK.  mod 8 "Window" size. */
+
+	p_misc_config->maxframe_extended = AX25_K_MAXFRAME_EXTENDED_DEFAULT;	/* Max frames to send before ACK.  mod 128 "Window" size. */
+
+	p_misc_config->maxv22 = AX25_N2_RETRY_DEFAULT / 2;	/* Max SABME before falling back to SABM. */
 
 /* 
  * Try to extract options from a file.
@@ -1568,6 +1587,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 /*
  * PTT 		- Push To Talk signal line.
  * DCD		- Data Carrier Detect indicator.
+ * CON		- Connected to another station indicator.
  *
  * xxx  serial-port [-]rts-or-dtr [ [-]rts-or-dtr ]
  * xxx  GPIO  [-]gpio-num
@@ -1582,7 +1602,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
  * Applies to most recent CHANNEL command.
  */
 
-	  else if (strcasecmp(t, "PTT") == 0 || strcasecmp(t, "DCD") == 0) {
+	  else if (strcasecmp(t, "PTT") == 0 || strcasecmp(t, "DCD") == 0 || strcasecmp(t, "CON") == 0) {
 	    int ot;
 	    char otname[8];
 
@@ -1595,8 +1615,8 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	      strlcpy (otname, "DCD", sizeof(otname));
 	    }
 	    else {
-	      ot = OCTYPE_FUTURE;
-	      strlcpy (otname, "FUTURE", sizeof(otname));
+	      ot = OCTYPE_CON;
+	      strlcpy (otname, "CON", sizeof(otname));
 	    }
 
 	    t = split(NULL,0);
@@ -1784,7 +1804,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	      }  /* end of second serial port control line. */
 	    }  /* end of serial port case. */
 
-	  }  /* end of PTT */
+	  }  /* end of PTT, DCD, CON */
 
 /*
  * INPUTS
@@ -1984,14 +2004,14 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  }
 
 /*
- * ==================== Digipeater parameters ==================== 
+ * ==================== APRS Digipeater parameters ====================
  */
 
 /*
  * DIGIPEAT  from-chan  to-chan  alias-pattern  wide-pattern  [ OFF|DROP|MARK|TRACE ] 
  */
 
-	  else if (strcasecmp(t, "digipeat") == 0) {
+	  else if (strcasecmp(t, "DIGIPEAT") == 0 || strcasecmp(t, "DIGIPEATER") == 0) {
 	    int from_chan, to_chan;
 	    int e;
 	    char message[100];
@@ -2175,7 +2195,82 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 
 /*
- * ==================== Packet Filtering for digipeater or IGate ==================== 
+ * ==================== Connected Digipeater parameters ====================
+ */
+
+/*
+ * CDIGIPEAT  from-chan  to-chan [ alias-pattern ]
+ */
+
+	  else if (strcasecmp(t, "CDIGIPEAT") == 0 || strcasecmp(t, "CDIGIPEATER") == 0) {
+	    int from_chan, to_chan;
+	    int e;
+	    char message[100];
+
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Missing FROM-channel on line %d.\n", line);
+	      continue;
+	    }
+	    from_chan = atoi(t);
+	    if (from_chan < 0 || from_chan >= MAX_CHANS) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: FROM-channel must be in range of 0 to %d on line %d.\n",
+							MAX_CHANS-1, line);
+	      continue;
+	    }
+	    if ( ! p_audio_config->achan[from_chan].valid) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file, line %d: FROM-channel %d is not valid.\n",
+							line, from_chan);
+	      continue;
+	    }
+
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Missing TO-channel on line %d.\n", line);
+	      continue;
+	    }
+	    to_chan = atoi(t);
+	    if (to_chan < 0 || to_chan >= MAX_CHANS) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: TO-channel must be in range of 0 to %d on line %d.\n",
+							MAX_CHANS-1, line);
+	      continue;
+	    }
+	    if ( ! p_audio_config->achan[to_chan].valid) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file, line %d: TO-channel %d is not valid.\n",
+							line, to_chan);
+	      continue;
+	    }
+
+	    t = split(NULL,0);
+	    if (t != NULL) {
+	      e = regcomp (&(p_cdigi_config->alias[from_chan][to_chan]), t, REG_EXTENDED|REG_NOSUB);
+	      if (e != 0) {
+	        regerror (e, &(p_cdigi_config->alias[from_chan][to_chan]), message, sizeof(message));
+	        text_color_set(DW_COLOR_ERROR);
+	        dw_printf ("Config file: Invalid alias matching pattern on line %d:\n%s\n",
+							line, message);
+	        continue;
+	      }
+	      t = split(NULL,0);
+	    }
+
+	    p_cdigi_config->enabled[from_chan][to_chan] = 1;
+
+	    if (t != NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file, line %d: Found \"%s\" where end of line was expected.\n", line, t);
+	    }
+	  }
+
+
+/*
+ * ==================== Packet Filtering for APRS digipeater or IGate ====================
  */
 
 /*
@@ -2252,6 +2347,74 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  }
 
 
+/*
+ * ==================== Packet Filtering for connected digipeater ====================
+ */
+
+/*
+ * CFILTER  from-chan  to-chan  filter_specification_expression
+ */
+
+	  else if (strcasecmp(t, "CFILTER") == 0) {
+	    int from_chan, to_chan;
+	    	    
+
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Missing FROM-channel on line %d.\n", line);
+	      continue;
+	    }
+
+	    from_chan = isdigit(*t) ? atoi(t) : -999;
+	    if (from_chan < 0 || from_chan >= MAX_CHANS) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Filter FROM-channel must be in range of 0 to %d on line %d.\n",
+							MAX_CHANS-1, line);
+	      continue;
+	    }
+
+	    if ( ! p_audio_config->achan[from_chan].valid) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file, line %d: FROM-channel %d is not valid.\n",
+							line, from_chan);
+	      continue;
+	    }
+
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Missing TO-channel on line %d.\n", line);
+	      continue;
+	    }
+
+	    to_chan = isdigit(*t) ? atoi(t) : -999;
+	    if (to_chan < 0 || to_chan >= MAX_CHANS) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: Filter TO-channel must be in range of 0 to %d on line %d.\n",
+							MAX_CHANS-1, line);
+	      continue;
+	    }
+	    if ( ! p_audio_config->achan[to_chan].valid) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file, line %d: TO-channel %d is not valid.\n",
+							line, to_chan);
+	      continue;
+	    }
+
+	    t = split(NULL,1);		/* Take rest of line including spaces. */
+
+	    if (t == NULL) {
+	      t = " ";				/* Empty means permit nothing. */
+	    }
+
+	    p_cdigi_config->filter_str[from_chan][to_chan] = strdup(t);
+
+//TODO1.2:  Do a test run to see errors now instead of waiting.
+
+	  }
+
+
 /*
  * ==================== APRStt gateway ==================== 
  */
@@ -4163,6 +4326,154 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	    p_misc_config->sb_configured = 1;
 	  }
 
+
+/*
+ * ==================== AX.25 connected mode ====================
+ */
+
+
+/*
+ * FRACK  n 		- Number of seconds to wait for ack to transmission.
+ */
+
+	  else if (strcasecmp(t, "FRACK") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for FRACK.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= AX25_T1V_FRACK_MIN && n <= AX25_T1V_FRACK_MAX) {
+	      p_misc_config->frack = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid FRACK time. Using default %d.\n", line, p_misc_config->frack);
+	    }
+	  }
+
+
+/*
+ * RETRY  n 		- Number of times to retry before giving up.
+ */
+
+	  else if (strcasecmp(t, "RETRY") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for RETRY.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= AX25_N2_RETRY_MIN && n <= AX25_N2_RETRY_MAX) {
+	      p_misc_config->retry = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid RETRY number. Using default %d.\n", line, p_misc_config->retry);
+	    }
+	  }
+
+
+/*
+ * PACLEN  n 		- Maximum number of bytes in information part.
+ */
+
+	  else if (strcasecmp(t, "PACLEN") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for PACLEN.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= AX25_N1_PACLEN_MIN && n <= AX25_N1_PACLEN_MAX) {
+	      p_misc_config->paclen = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid PACLEN value. Using default %d.\n", line, p_misc_config->paclen);
+	    }
+	  }
+
+
+/*
+ * MAXFRAME  n 		- Max frames to send before ACK.  mod 8 "Window" size.
+ *
+ * Window size would make more sense but everyone else calls it MAXFRAME.
+ */
+
+	  else if (strcasecmp(t, "MAXFRAME") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for MAXFRAME.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= AX25_K_MAXFRAME_BASIC_MIN && n <= AX25_K_MAXFRAME_BASIC_MAX) {
+	      p_misc_config->maxframe_basic = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid MAXFRAME value outside range of %d to %d. Using default %d.\n",
+			line, AX25_K_MAXFRAME_BASIC_MIN, AX25_K_MAXFRAME_BASIC_MAX, p_misc_config->maxframe_basic);
+	    }
+	  }
+
+
+
+/*
+ * EMAXFRAME  n 		- Max frames to send before ACK.  mod 128 "Window" size.
+ */
+
+	  else if (strcasecmp(t, "EMAXFRAME") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for EMAXFRAME.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= AX25_K_MAXFRAME_EXTENDED_MIN && n <= AX25_K_MAXFRAME_EXTENDED_MAX) {
+	      p_misc_config->maxframe_extended = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid EMAXFRAME value outside of range %d to %d. Using default %d.\n",
+			line, AX25_K_MAXFRAME_EXTENDED_MIN, AX25_K_MAXFRAME_EXTENDED_MAX, p_misc_config->maxframe_extended);
+   	    }
+	  }
+
+/*
+ * MAXV22  n 		- Max number of SABME sent before trying SABM.
+ */
+
+	  else if (strcasecmp(t, "MAXV22") == 0) {
+	    int n;
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing value for MAXV22.\n", line);
+	      continue;
+	    }
+	    n = atoi(t);
+            if (n >= 0 && n <= AX25_N2_RETRY_MAX) {
+	      p_misc_config->maxv22 = n;
+	    }
+	    else {
+	      text_color_set(DW_COLOR_ERROR);
+              dw_printf ("Line %d: Invalid MAXV22 number. Will use half of RETRY.\n", line);
+	    }
+	  }
+
+
 /*
  * Invalid command.
  */
@@ -4189,6 +4500,8 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	for (i=0; i<MAX_CHANS; i++) {
 	  for (j=0; j<MAX_CHANS; j++) {
 
+/* APRS digipeating. */
+
 	    if (p_digi_config->enabled[i][j]) {
 
 	      if ( strcmp(p_audio_config->achan[i].mycall, "") == 0 || 
@@ -4221,6 +4534,39 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	        //p_digi_config->enabled[i][j] = 0;
 	      }
 	    }
+
+/* Connected mode digipeating. */
+
+	    if (p_cdigi_config->enabled[i][j]) {
+
+	      if ( strcmp(p_audio_config->achan[i].mycall, "") == 0 ||
+		   strcmp(p_audio_config->achan[i].mycall, "NOCALL") == 0 ||
+		   strcmp(p_audio_config->achan[i].mycall, "N0CALL") == 0) {
+
+	        text_color_set(DW_COLOR_ERROR);
+	        dw_printf ("Config file: MYCALL must be set for receive channel %d before digipeating is allowed.\n", i);
+	        p_cdigi_config->enabled[i][j] = 0;
+	      }
+
+	      if ( strcmp(p_audio_config->achan[j].mycall, "") == 0 ||
+	           strcmp(p_audio_config->achan[j].mycall, "NOCALL") == 0 ||
+		   strcmp(p_audio_config->achan[j].mycall, "N0CALL") == 0) {
+
+	        text_color_set(DW_COLOR_ERROR);
+	        dw_printf ("Config file: MYCALL must be set for transmit channel %d before digipeating is allowed.\n", i);
+	        p_cdigi_config->enabled[i][j] = 0;
+	      }
+
+	      b = 0;
+	      for (k=0; k<p_misc_config->num_beacons; k++) {
+	        if (p_misc_config->beacon[k].sendto_chan == j) b++;
+	      }
+	      if (b == 0) {
+	        text_color_set(DW_COLOR_ERROR);
+	        dw_printf ("Config file: Beaconing should be configured for channel %d when digipeating is enabled.\n", j);
+		// It's a recommendation, not a requirement.
+	      }
+	    }
 	  }
 
 	  if (p_audio_config->achan[i].valid && strlen(p_igate_config->t2_login) > 0) {
@@ -4243,6 +4589,10 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 	}
 
+	if (p_misc_config->maxv22 < 0) {
+	  p_misc_config->maxv22 = p_misc_config->retry / 2;
+	}
+
 } /* end config_init */
 
 

config.h

@@ -15,6 +15,7 @@
 
 #include "audio.h"		/* for struct audio_s */
 #include "digipeater.h"		/* for struct digi_config_s */
+#include "cdigipeater.h"		/* for struct cdigi_config_s */
 #include "aprs_tt.h"		/* for struct tt_config_s */
 #include "igate.h"		/* for struct igate_config_s */
 
@@ -76,6 +77,25 @@ struct misc_config_s {
 	int sb_turn_angle;	/* degrees */
 	int sb_turn_slope;	/* degrees * MPH */
 
+// AX.25 connected mode.
+
+	int frack;		/* Number of seconds to wait for ack to transmission. */
+
+	int retry;		/* Number of times to retry before giving up. */
+
+	int paclen;		/* Max number of bytes in information part of frame. */
+
+	int maxframe_basic;	/* Max frames to send before ACK.  mod 8 "Window" size. */
+
+	int maxframe_extended;	/* Max frames to send before ACK.  mod 128 "Window" size. */
+
+	int maxv22;		/* Maximum number of unanswered SABME frames sent before */
+				/* switching to SABM.  This is to handle the case of an old */
+				/* TNC which simply ignores SABME rather than replying with FRMR. */
+
+
+
+// Beacons.
  			
 	int num_beacons;	/* Number of beacons defined. */
 
@@ -166,6 +186,7 @@ struct misc_config_s {
 
 extern void config_init (char *fname, struct audio_s *p_modem, 
 			struct digi_config_s *digi_config,
+			struct cdigi_config_s *cdigi_config,
 			struct tt_config_s *p_tt_config,
 			struct igate_config_s *p_igate_config,
 			struct misc_config_s *misc_config);

digipeater.c

@@ -23,6 +23,7 @@
  * Name:	digipeater.c
  *
  * Purpose:	Act as an APRS digital repeater.
+ *		Similar cdigipeater.c is for connected mode.
  *
  *
  * Description:	Decide whether the specified packet should
@@ -255,6 +256,10 @@ void digipeater (int from_chan, packet_t pp)
  *
  *------------------------------------------------------------------------------*/
 
+#define OBSOLETE14 1
+
+
+#ifndef OBSOLETE14
 static char *dest_ssid_path[16] = { 	
 			"",		/* Use VIA path */
 			"WIDE1-1",
@@ -272,6 +277,7 @@ static char *dest_ssid_path[16] = {
 			"WIDE2-2",	/* South */
 			"WIDE2-2",	/* East */
 			"WIDE2-2"  };	/* West */
+#endif
 				  
 
 static packet_t digipeat_match (int from_chan, packet_t pp, char *mycall_rec, char *mycall_xmit, 
@@ -290,7 +296,7 @@ static packet_t digipeat_match (int from_chan, packet_t pp, char *mycall_rec, ch
 
 	if (filter_str != NULL) {
 
-	  if (pfilter(from_chan, to_chan, filter_str, pp) != 1) {
+	  if (pfilter(from_chan, to_chan, filter_str, pp, 1) != 1) {
 
 // TODO1.2: take out debug message
 // Actually it turns out to be useful.
@@ -322,11 +328,15 @@ static packet_t digipeat_match (int from_chan, packet_t pp, char *mycall_rec, ch
  * Otherwise we don't want to modify the input because this could be called multiple times.
  */
 
+#ifndef OBSOLETE14		// Took it out in 1.4
+
 	if (ax25_get_num_repeaters(pp) == 0 && (ssid = ax25_get_ssid(pp, AX25_DESTINATION)) > 0) {
 	  ax25_set_addr(pp, AX25_REPEATER_1, dest_ssid_path[ssid]);
 	  ax25_set_ssid(pp, AX25_DESTINATION, 0);
 	  /* Continue with general case, below. */
 	}
+#endif
+
 
 /* 
  * Find the first repeater station which doesn't have "has been repeated" set.
@@ -795,11 +805,15 @@ int main (int argc, char *argv[])
 
 
 /* 
- * Change destination SSID to normal digipeater if none specified.
+ * Change destination SSID to normal digipeater if none specified.  (Obsolete, removed.)
  */
-	test (	"W1ABC>TEST-3:",
-		"W1ABC>TEST,WB2OSZ-9*,WIDE3-2:");
 
+	test (	"W1ABC>TEST-3:",
+#ifndef OBSOLETE14
+		"W1ABC>TEST,WB2OSZ-9*,WIDE3-2:");
+#else
+		"");
+#endif
 	test (	"W1DEF>TEST-3,WIDE2-2:",
 		"W1DEF>TEST-3,WB2OSZ-9*,WIDE2-1:");
 

direwolf.c

@@ -88,6 +88,7 @@
 #include "hdlc_rec.h"
 #include "hdlc_rec2.h"
 #include "ax25_pad.h"
+#include "xid.h"
 #include "decode_aprs.h"
 #include "textcolor.h"
 #include "server.h"
@@ -97,6 +98,7 @@
 #include "waypoint.h"
 #include "gen_tone.h"
 #include "digipeater.h"
+#include "cdigipeater.h"
 #include "tq.h"
 #include "xmit.h"
 #include "ptt.h"
@@ -112,6 +114,7 @@
 #include "recv.h"
 #include "morse.h"
 #include "mheard.h"
+#include "ax25_link.h"
 
 
 //static int idx_decoded = 0;
@@ -158,7 +161,8 @@ static void __cpuid(int cpuinfo[4], int infotype){
 
 static struct audio_s audio_config;
 static struct tt_config_s tt_config;
-struct digi_config_s digi_config;
+//struct digi_config_s digi_config;
+//struct cdigi_config_s cdigi_config;
 
 
 static int d_u_opt = 0;			/* "-d u" command line option to print UTF-8 also in hexadecimal. */
@@ -181,6 +185,7 @@ int main (int argc, char *argv[])
 	int xmit_calibrate_option = 0;
 	int enable_pseudo_terminal = 0;
 	struct digi_config_s digi_config;
+	struct cdigi_config_s cdigi_config;
 	struct igate_config_s igate_config;
 	int r_opt = 0, n_opt = 0, b_opt = 0, B_opt = 0, D_opt = 0;	/* Command line options. */
 	char P_opt[16];
@@ -199,6 +204,8 @@ int main (int argc, char *argv[])
 #if USE_HAMLIB
 	int d_h_opt = 0;	/* "-d h" option for hamlib debugging.  Repeat for more detail */
 #endif
+	int E_tx_opt = 0;		/* "-E n" Error rate % for clobbering trasmit frames. */
+	int E_rx_opt = 0;		/* "-E Rn" Error rate % for clobbering receive frames. */
 
 	strlcpy(l_opt, "", sizeof(l_opt));
 	strlcpy(P_opt, "", sizeof(P_opt));
@@ -247,7 +254,7 @@ int main (int argc, char *argv[])
 	text_color_init(t_opt);
 	text_color_set(DW_COLOR_INFO);
 	//dw_printf ("Dire Wolf version %d.%d (%s) Beta Test\n", MAJOR_VERSION, MINOR_VERSION, __DATE__);
-	dw_printf ("Dire Wolf DEVELOPMENT version %d.%d %s (%s)\n", MAJOR_VERSION, MINOR_VERSION, "C", __DATE__);
+	dw_printf ("Dire Wolf DEVELOPMENT version %d.%d %s (%s)\n", MAJOR_VERSION, MINOR_VERSION, "D", __DATE__);
 	//dw_printf ("Dire Wolf version %d.%d\n", MAJOR_VERSION, MINOR_VERSION);
 
 #if defined(ENABLE_GPSD) || defined(USE_HAMLIB)
@@ -332,7 +339,7 @@ int main (int argc, char *argv[])
 
 	  /* ':' following option character means arg is required. */
 
-          c = getopt_long(argc, argv, "P:B:D:c:pxr:b:n:d:q:t:Ul:Sa:",
+          c = getopt_long(argc, argv, "P:B:D:c:pxr:b:n:d:q:t:Ul:Sa:E:",
                         long_options, &option_index);
           if (c == -1)
             break;
@@ -518,6 +525,27 @@ int main (int argc, char *argv[])
 	    exit (0);
 	    break;
 
+          case 'E':				/* -E Error rate (%) for corrupting frames. */
+						/* Just a number is transmit.  Precede by R for receive. */
+
+	    if (*optarg == 'r' || *optarg == 'R') {
+	      E_rx_opt = atoi(optarg+1);
+	      if (E_rx_opt < 1 || E_rx_opt > 99) {
+	        text_color_set(DW_COLOR_ERROR);
+                  dw_printf("-ER must be in range of 1 to 99.\n");
+	      E_rx_opt = 10;
+	      }
+	    }
+	    else {
+	      E_tx_opt = atoi(optarg);
+	      if (E_tx_opt < 1 || E_tx_opt > 99) {
+	        text_color_set(DW_COLOR_ERROR);
+                dw_printf("-E must be in range of 1 to 99.\n");
+	        E_tx_opt = 10;
+	      }
+	    }
+            break;
+
           default:
 
             /* Should not be here. */
@@ -552,7 +580,7 @@ int main (int argc, char *argv[])
 
 	symbols_init ();
 
-	config_init (config_file, &audio_config, &digi_config, &tt_config, &igate_config, &misc_config);
+	config_init (config_file, &audio_config, &digi_config, &cdigi_config, &tt_config, &igate_config, &misc_config);
 
 	if (r_opt != 0) {
 	  audio_config.adev[0].samples_per_sec = r_opt;
@@ -621,6 +649,12 @@ int main (int argc, char *argv[])
 	    audio_config.achan[0].decimate = D_opt;
 	}
 
+	// temp - only xmit errors.
+
+	audio_config.xmit_error_rate = E_tx_opt;
+	audio_config.recv_error_rate = E_rx_opt;
+
+
 	if (strlen(l_opt) > 0) {
 	  strlcpy (misc_config.logdir, l_opt, sizeof(misc_config.logdir));
 	}
@@ -711,6 +745,8 @@ int main (int argc, char *argv[])
  */
 	digipeater_init (&audio_config, &digi_config);
 	igate_init (&audio_config, &igate_config, &digi_config, d_i_opt);
+	cdigipeater_init (&audio_config, &cdigi_config);
+	ax25_link_init (&misc_config);
 
 /*
  * Provide the AGW & KISS socket interfaces for use by a client application.
@@ -890,7 +926,7 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 	    text_color_set(DW_COLOR_REC);
 	  }
 	  else {
-	    text_color_set(DW_COLOR_DEBUG);
+	    text_color_set(DW_COLOR_DECODED);
 	  }
 
 	  if (audio_config.achan[chan].num_subchan > 1 && audio_config.achan[chan].num_slicers == 1) {
@@ -914,26 +950,41 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 	if ( ! ax25_is_aprs(pp)) {
 	  ax25_frame_type_t ftype;
 	  cmdres_t cr;
-	  char desc[32];
+	  char desc[80];
 	  int pf;
 	  int nr;
 	  int ns;
 
 	  ftype = ax25_frame_type (pp, &cr, desc, &pf, &nr, &ns);
-	  (void)ftype;
+
+	  /* Could change by 1, since earlier call, if we guess at modulo 128. */
+	  info_len = ax25_get_info (pp, &pinfo);
 
 	  dw_printf ("(%s)", desc);
+	  if (ftype == frame_type_U_XID) {
+	    struct xid_param_s param;
+	    char info2text[100];
+
+	    xid_parse (pinfo, info_len, &param, info2text, sizeof(info2text));
+	    dw_printf (" %s\n", info2text);
+	  }
+	  else {
+	    ax25_safe_print ((char *)pinfo, info_len, ( ! ax25_is_aprs(pp)) && ( ! d_u_opt) );
+	    dw_printf ("\n");
+	  }
+	}
+	else {
+
+	  // for APRS we generally want to display non-ASCII to see UTF-8.
+	  // for other, probably want to restrict to ASCII only because we are
+	  // more likely to have compressed data than UTF-8 text.
+
+	  // TODO: Might want to use d_u_opt for transmitted frames too.
+
+	  ax25_safe_print ((char *)pinfo, info_len, ( ! ax25_is_aprs(pp)) && ( ! d_u_opt) );
+	  dw_printf ("\n");
 	}
 
-	// for APRS we generally want to display non-ASCII to see UTF-8.
-	// for other, probably want to restrict to ASCII only because we are
-	// more likely to have compressed data than UTF-8 text.
-
-	// TODO: Might want to use d_u_opt for transmitted frames too.
-
-
-	ax25_safe_print ((char *)pinfo, info_len, ( ! ax25_is_aprs(pp)) && ( ! d_u_opt) );
-	dw_printf ("\n");
 
 // Also display in pure ASCII if non-ASCII characters and "-d u" option specified.
 
@@ -992,6 +1043,9 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 
 	  log_write (chan, &A, pp, alevel, retries);
 
+	  // temp experiment.
+	  //log_rr_bits (&A, pp);
+
 	  // Add to list of stations heard.
 
 	  mheard_save (chan, &A, pp, alevel, retries);
@@ -1052,23 +1106,30 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 
 
 /*
- * Note that the digipeater function can modify the packet in place so 
- * this is the last thing we should do with it. 
- * Again, use only those with correct CRC; We don't want to spread corrupted data!
- * Single bit change appears to be safe from observations so far but be cautious. 
+ * APRS digipeater.
+ * Use only those with correct CRC; We don't want to spread corrupted data!
  */
 
 	  if (ax25_is_aprs(pp) && retries == RETRY_NONE) {
 
 	    digipeater (chan, pp);
 	  }
+
+/*
+ * Connected mode digipeater.
+ * Use only those with correct CRC.
+ */
+
+	  if (retries == RETRY_NONE) {
+
+	    cdigipeater (chan, pp);
+	  }
 	}
 
-	ax25_delete (pp);
-	
 } /* end app_process_rec_packet */
 
 
+
 /* Process control C and window close events. */
 
 #if __WIN32__

direwolf.h

@@ -233,6 +233,11 @@ char *strcasestr(const char *S, const char *FIND);
 #else   // Use our own copy
 
 
+// These prevent /usr/include/gps.h from providing its own definition.
+#define HAVE_STRLCAT 1
+#define HAVE_STRLCPY 1
+
+
 #define DEBUG_STRL 1
 
 #if DEBUG_STRL

dlq.c

@@ -24,7 +24,7 @@
  *
  * Purpose:   	Received frame queue.
  *
- * Description: In earlierversions, the main thread read from the
+ * Description: In earlier versions, the main thread read from the
  *		audio device and performed the receive demodulation/decoding.
  *
  *		Since version 1.2 we have a separate receive thread
@@ -32,7 +32,7 @@
  *		received frames from all channels and process them
  *		serially.
  *
- *		In version 1.4, other types of events go into this
+ *		In version 1.4, other types of events also go into this
  *		queue and we use it to drive the data link state machine.
  *
  *---------------------------------------------------------------*/
@@ -85,10 +85,13 @@ static int was_init = 0;			/* was initialization performed? */
 
 static void append_to_queue (struct dlq_item_s *pnew);
 
-static volatile int s_new_count = 0;		/* To detect memory leak. */
-static volatile int s_delete_count = 0;			// TODO:  need to test.
+static volatile int s_new_count = 0;		/* To detect memory leak for queue items. */
+static volatile int s_delete_count = 0;		// TODO:  need to test.
 
 
+static volatile int s_cdata_new_count = 0;		/* To detect memory leak for connected mode data. */
+static volatile int s_cdata_delete_count = 0;		// TODO:  need to test.
+
 
 
 /*-------------------------------------------------------------------
@@ -109,8 +112,6 @@ static volatile int s_delete_count = 0;			// TODO:  need to test.
 
 void dlq_init (void)
 {
-	//int c, p;
-
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
 	dw_printf ("dlq_init ( )\n");
@@ -189,6 +190,7 @@ void dlq_init (void)
  *		Normally this was received over the radio but we can create
  *		our own from APRStt or beaconing.
  *
+ *		This would correspond to PH-DATA Indication in the AX.25 protocol spec.
  *
  * Inputs:	chan	- Channel, 0 is first.
  *
@@ -244,11 +246,17 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 	}
 #endif
 
+
 /* Allocate a new queue item. */
 
 	pnew = (struct dlq_item_s *) calloc (sizeof(struct dlq_item_s), 1);
 	s_new_count++;
 
+	if (s_new_count > s_delete_count + 50) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("INTERNAL ERROR:  DLQ memory leak, new=%d, delete=%d\n", s_new_count, s_delete_count);
+	}
+
 	pnew->nextp = NULL;
 	pnew->type = DLQ_REC_FRAME;
 	pnew->chan = chan;
@@ -458,6 +466,7 @@ static void append_to_queue (struct dlq_item_s *pnew)
  *		pid		- Protocol ID for data.  Normally 0xf0 but the API
  *				  allows the client app to use something non-standard
  *				  for special situations.
+ *						TODO: remove this.   PID is only for I and UI frames.
  *
  * Outputs:	Request is appended to queue for processing by
  *		the data link state machine.
@@ -486,7 +495,6 @@ void dlq_connect_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num
 	memcpy (pnew->addrs, addrs, sizeof(pnew->addrs));
 	pnew->num_addr = num_addr;
 	pnew->client = client;
-	pnew->pid = pid;
 
 /* Put it into queue. */
 
@@ -603,9 +611,10 @@ void dlq_xmit_data_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int n
 	memcpy (pnew->addrs, addrs, sizeof(pnew->addrs));
 	pnew->num_addr = num_addr;
 	pnew->client = client;
-	pnew->pid = pid;
 
-/* TODO:  haven't thought about user data yet. */
+/* Attach the transmit data. */
+
+	pnew->txdata = cdata_new(pid,xdata_ptr,xdata_len);
 
 /* Put it into queue. */
 
@@ -614,6 +623,195 @@ void dlq_xmit_data_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int n
 } /* end dlq_xmit_data_request */
 
 
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        dlq_register_callsign
+ *		dlq_unregister_callsign
+ *
+ * Purpose:     Register callsigns that we will recognize for incoming connection requests.
+ *
+ * Inputs:	addrs		- Source (owncall), destination (peercall),
+ *				  and possibly digipeaters.
+ *
+ *		chan		- Channel, 0 is first.
+ *
+ *		client		- Client application instance.
+ *
+ * Outputs:	Request is appended to queue for processing by
+ *		the data link state machine.
+ *
+ * Description:	The data link state machine does not use MYCALL from the APRS configuration.
+ *		For outgoing frames, the client supplies the source callsign.
+ *		For incoming connection requests, we need to know what address(es) to respond to.
+ *
+ *		Note that one client application can register multiple callsigns for
+ *		multiple channels.
+ *		Different clients can register different different addresses on the same channel.
+ *
+ *--------------------------------------------------------------------*/
+
+
+void dlq_register_callsign (char addr[AX25_MAX_ADDR_LEN], int chan, int client)
+{
+	struct dlq_item_s *pnew;
+
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("dlq_register_callsign (%s, chan=%d, client=%d)\n", addr, chan, client);
+#endif
+
+	assert (chan >= 0 && chan < MAX_CHANS);
+
+/* Allocate a new queue item. */
+
+	pnew = (struct dlq_item_s *) calloc (sizeof(struct dlq_item_s), 1);
+	s_new_count++;
+
+	pnew->type = DLQ_REGISTER_CALLSIGN;
+	pnew->chan = chan;
+	strlcpy (pnew->addrs[0], addr, AX25_MAX_ADDR_LEN);
+	pnew->num_addr = 1;
+	pnew->client = client;
+
+/* Put it into queue. */
+
+	append_to_queue (pnew);
+
+} /* end dlq_register_callsign */
+
+
+void dlq_unregister_callsign (char addr[AX25_MAX_ADDR_LEN], int chan, int client)
+{
+	struct dlq_item_s *pnew;
+
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("dlq_unregister_callsign (%s, chan=%d, client=%d)\n", addr, chan, client);
+#endif
+
+	assert (chan >= 0 && chan < MAX_CHANS);
+
+/* Allocate a new queue item. */
+
+	pnew = (struct dlq_item_s *) calloc (sizeof(struct dlq_item_s), 1);
+	s_new_count++;
+
+	pnew->type = DLQ_UNREGISTER_CALLSIGN;
+	pnew->chan = chan;
+	strlcpy (pnew->addrs[0], addr, AX25_MAX_ADDR_LEN);
+	pnew->num_addr = 1;
+	pnew->client = client;
+
+/* Put it into queue. */
+
+	append_to_queue (pnew);
+
+} /* end dlq_unregister_callsign */
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        dlq_channel_busy
+ *
+ * Purpose:     Inform data link state machine about activity on the radio channel.
+ *
+ * Inputs:	chan		- Radio channel number.
+ *
+ *		activity	- OCTYPE_PTT or OCTYPE_DCD, as defined in audio.h.
+ *				  Other values will be discarded.
+ *
+ *		status		- 1 for active or 0 for quiet.
+ *
+ * Outputs:	Request is appended to queue for processing by
+ *		the data link state machine.
+ *
+ * Description:	Notify the link state machine about changes in carrier detect
+ *		and our transmitter.
+ *		This is needed for pausing some of our timers.   For example,
+ *		if we transmit a frame and expect a response in 3 seconds, that
+ *		might be delayed because someone else is using the channel.
+ *
+ *--------------------------------------------------------------------*/
+
+void dlq_channel_busy (int chan, int activity, int status)
+{
+	struct dlq_item_s *pnew;
+
+	if (activity == OCTYPE_PTT || activity == OCTYPE_DCD) {
+#if DEBUG
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("dlq_channel_busy (...)\n");
+#endif
+
+
+/* Allocate a new queue item. */
+
+	  pnew = (struct dlq_item_s *) calloc (sizeof(struct dlq_item_s), 1);
+	  s_new_count++;
+
+	  pnew->type = DLQ_CHANNEL_BUSY;
+	  pnew->chan = chan;
+	  pnew->activity = activity;
+	  pnew->status = status;
+
+/* Put it into queue. */
+
+	  append_to_queue (pnew);
+	}
+
+} /* end dlq_channel_busy */
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        dlq_client_cleanup
+ *
+ * Purpose:     Client application has disappeared.
+ *		i.e. The TCP connection has been broken.
+ *
+ * Inputs:	client		- Client application instance.
+ *
+ * Outputs:	Request is appended to queue for processing by
+ *		the data link state machine.
+ *
+ * Description:	Notify the link state machine that given client has gone away.
+ *		Clean up all information related to that client application.
+ *
+ *--------------------------------------------------------------------*/
+
+void dlq_client_cleanup (int client)
+{
+	struct dlq_item_s *pnew;
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("dlq_client_cleanup (...)\n");
+#endif
+
+	// assert (client >= 0 && client < MAX_NET_CLIENTS);
+
+/* Allocate a new queue item. */
+
+	pnew = (struct dlq_item_s *) calloc (sizeof(struct dlq_item_s), 1);
+	s_new_count++;
+
+	// All we care about is the client number.
+
+	pnew->type = DLQ_CLIENT_CLEANUP;
+	pnew->client = client;
+
+/* Put it into queue. */
+
+	append_to_queue (pnew);
+
+} /* end dlq_client_cleanup */
+
+
+
 /*-------------------------------------------------------------------
  *
  * Name:        dlq_wait_while_empty
@@ -817,12 +1015,145 @@ struct dlq_item_s *dlq_remove (void)
 
 void dlq_delete (struct dlq_item_s *pitem)
 {
+	if (pitem == NULL) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("INTERNAL ERROR: dlq_delete()  given NULL pointer.\n");
+	  return;
+	}
+
 	s_delete_count++;
-	if (pitem->pp != NULL) ax25_delete (pitem->pp)
+
+	if (pitem->pp != NULL) {
+	  ax25_delete (pitem->pp);
+	  pitem->pp = NULL;
+	}
+
+	if (pitem->txdata != NULL) {
+	  cdata_delete (pitem->txdata);
+	  pitem->txdata = NULL;
+	}
+
 	free (pitem);
 
 } /* end dlq_delete */
 
 
 
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        cdata_new
+ *
+ * Purpose:     Allocate blocks of data for sending and receiving connected data.
+ *
+ * Inputs:	pid	- protocol id.
+ *		data	- pointer to data.  Can be NULL for segment reassembler.
+ *		len	- length of data.
+ *
+ * Returns:	Structure with a copy of the data.
+ *
+ * Description:	The flow goes like this:
+ *
+ *		Client application extablishes a connection with another station.
+ *		Client application calls "dlq_xmit_data_request."
+ *		A copy of the data is made with this function and attached to the queue item.
+ *		The txdata block is attached to the appropriate link state machine.
+ *		At the proper time, it is transmitted in an I frame.
+ *		It needs to be kept around in case it needs to be retransmitted.
+ *		When no longer needed, it is freed with cdata_delete.
+ *
+ *--------------------------------------------------------------------*/
+
+
+cdata_t *cdata_new (int pid, char *data, int len)
+{
+	int size;
+	cdata_t *cdata;
+
+	s_cdata_new_count++;
+
+	/* Round up the size to the next 128 bytes. */
+	/* The theory is that a smaller number of unique sizes might be */
+	/* beneficial for memory fragmentation and garbage collection. */
+
+	size = ( len + 127 ) & ~0x7f;
+
+	cdata = malloc ( sizeof(cdata_t) + size );
+
+	cdata->magic = TXDATA_MAGIC;
+	cdata->next = NULL;
+	cdata->pid = pid;
+	cdata->size = size;
+	cdata->len = len;
+
+	assert (len >= 0 && len <= size);
+	if (data == NULL) {
+	  memset (cdata->data, '?', size);
+	}
+	else {
+	  memcpy (cdata->data, data, len);
+	}
+	return (cdata);
+
+}  /* end cdata_new */
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        cdata_delete
+ *
+ * Purpose:     Release storage used by a connected data block.
+ *
+ * Inputs:	cdata		- Pointer to a data block.
+ *
+ *--------------------------------------------------------------------*/
+
+
+void cdata_delete (cdata_t *cdata)
+{
+	if (cdata == NULL) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("INTERNAL ERROR: cdata_delete()  given NULL pointer.\n");
+	  return;
+	}
+
+	if (cdata->magic != TXDATA_MAGIC) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("INTERNAL ERROR: cdata_delete()  given corrupted data.\n");
+	  return;
+	}
+
+	s_cdata_delete_count++;
+
+	cdata->magic = 0;
+
+	free (cdata);
+
+} /* end cdata_delete */
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        cdata_check_leak
+ *
+ * Purpose:     Check for memory leak of cdata items.
+ *
+ * Description:	This is called when we expect no outstanding allocations.
+ *
+ *--------------------------------------------------------------------*/
+
+
+void cdata_check_leak (void)
+{
+	if (s_cdata_delete_count != s_cdata_new_count) {
+
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("Internal Error, %s, new=%d, delete=%d\n", __func__, s_cdata_new_count, s_cdata_delete_count);
+	}
+
+} /* end cdata_check_leak */
+
+
+
 /* end dlq.c */

dlq.h

@@ -12,10 +12,30 @@
 #include "audio.h"
 
 
+/* A transmit or receive data block for connected mode. */
+
+typedef struct cdata_s {
+	int magic;			/* For integrity checking. */
+
+#define TXDATA_MAGIC 0x09110911
+
+	struct cdata_s *next;		/* Pointer to next when part of a list. */
+
+	int pid;			/* Protocol id. */
+
+	int size;			/* Number of bytes allocated. */
+
+	int len;			/* Number of bytes actually used. */
+
+	char data[];			/* Variable length data. */
+
+} cdata_t;
+
+
 
 /* Types of things that can be in queue. */
 
-typedef enum dlq_type_e {DLQ_REC_FRAME, DLQ_CONNECT_REQUEST, DLQ_DISCONNECT_REQUEST, DLQ_XMIT_DATA_REQUEST} dlq_type_t; 
+typedef enum dlq_type_e {DLQ_REC_FRAME, DLQ_CONNECT_REQUEST, DLQ_DISCONNECT_REQUEST, DLQ_XMIT_DATA_REQUEST, DLQ_REGISTER_CALLSIGN, DLQ_UNREGISTER_CALLSIGN, DLQ_CHANNEL_BUSY, DLQ_CLIENT_CLEANUP} dlq_type_t;
 
 
 /* A queue item. */
@@ -28,10 +48,13 @@ typedef struct dlq_item_s {
 	struct dlq_item_s *nextp;	/* Next item in queue. */
 
 	dlq_type_t type;		/* Type of item. */
-					/* DLQ_REC_FRAME, DLQ_CONNECT_REQUEST, DLQ_DISCONNECT_REQUEST, DLQ_XMIT_DATA_REQUEST	 */
+					/* See enum definition above. */
 
 	int chan;			/* Radio channel of origin. */
 
+// I'm not worried about amount of memory used but this might be a
+// little clearer if a union was used for the different event types.
+
 // Used for received frame.
 
 	int subchan;			/* Winning "subchannel" when using multiple */
@@ -49,7 +72,7 @@ typedef struct dlq_item_s {
 
 	char spectrum[MAX_SUBCHANS*MAX_SLICERS+1];	/* "Spectrum" display for multi-decoders. */
 
-// Used by requests from a client application.
+// Used by requests from a client application, connect, etc.
 
 	char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN];
 
@@ -57,9 +80,19 @@ typedef struct dlq_item_s {
 
 	int client;
 
-	int pid;
 
-	/* TODO: xmit data */
+// Used only by client request to transmit connected data.
+
+	cdata_t *txdata;
+
+// Used for channel activity change.
+// It is useful to know when the channel is busy either for carrier detect
+// or when we are transmitting.
+
+	int activity;			/* OCTYPE_PTT for my transmission start/end. */
+					/* OCTYPE_DCD if we hear someone else. */
+
+	int status;			/* 1 for active or 0 for quiet. */
 
 } dlq_item_t;
 
@@ -75,7 +108,16 @@ void dlq_connect_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num
 
 void dlq_disconnect_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, int chan, int client);
 
-void dlq_xmit_data_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, int chan, int clienti, int pid, char *xdata_ptr, int xdata_len);
+void dlq_xmit_data_request (char addrs[AX25_MAX_ADDRS][AX25_MAX_ADDR_LEN], int num_addr, int chan, int client, int pid, char *xdata_ptr, int xdata_len);
+
+void dlq_register_callsign (char addr[AX25_MAX_ADDR_LEN], int chan, int client);
+
+void dlq_unregister_callsign (char addr[AX25_MAX_ADDR_LEN], int chan, int client);
+
+void dlq_channel_busy (int chan, int activity, int status);
+
+void dlq_client_cleanup (int client);
+
 
 
 int dlq_wait_while_empty (double timeout_val);
@@ -84,6 +126,15 @@ struct dlq_item_s *dlq_remove (void);
 
 void dlq_delete (struct dlq_item_s *pitem);
 
+
+
+cdata_t *cdata_new (int pid, char *data, int len);
+
+void cdata_delete (cdata_t *txdata);
+
+void cdata_check_leak (void);
+
+
 #endif
 
 /* end dlq.h */

gen_packets.c

@@ -141,7 +141,7 @@ static void send_packet (char *str)
 	    }
 #endif
 	    hdlc_send_flags (c, 8, 0);
-	    hdlc_send_frame (c, fbuf, flen);
+	    hdlc_send_frame (c, fbuf, flen, 0);
 	    hdlc_send_flags (c, 2, 1);
 	  }
 	  ax25_delete (pp);

hdlc_rec.c

@@ -260,8 +260,15 @@ void hdlc_rec_bit (int chan, int subchan, int slice, int raw, int is_scrambled,
  * with the special "flag" characters.
  *
  * Idle time of all zero bits (alternating tones at maximum rate)
- * has also been observed rarely. 
- * Recognize zero(s) followed by a flag even though it vilolates the spec.
+ * has also been observed rarely. It is easy to understand the reasoning.
+ * The tones alternate at the maximum rate, making it symmetrical and providing
+ * the most opportunity for the PLL to lock on to the edges.
+ * It also violates the published protocol spec.
+ *
+ * Recognize zero(s) followed by a single flag even though it violates the spec.
+ *
+ * It has been reported that the TinyTrak4 does this.
+ * https://groups.yahoo.com/neo/groups/direwolf_packet/conversations/messages/1207
  */
 
 /*
@@ -304,6 +311,15 @@ void hdlc_rec_bit (int chan, int subchan, int slice, int raw, int is_scrambled,
 /* 
  * Loss of signal should result in lack of transitions.
  * (all '1' bits) for at least a little while.
+ *
+ * When this was written, I was only concerned about 1200 baud.
+ * For 9600, added later, there is a (de)scrambling function.
+ * So if there is no change in the signal, we would get pseudo random bits here.
+ * Maybe we need to put in another check earlier so DCD is not held on too long
+ * after loss of signal for 9600.
+ * No, that would not be a good idea.  part of a valid frame, when scrambled,
+ * could have seven or more "1" bits in a row.
+ * Needs more study.
  */
 
   

hdlc_send.c

@@ -52,6 +52,8 @@ static int number_of_bits_sent[MAX_CHANS];		// Count number of bits sent by "hdl
  *
  *		flen	- Frame length, not including the FCS.
  *
+ *		bad_fcs	- Append an invalid FCS for testing purposes.
+ *
  * Outputs:	Bits are shipped out by calling tone_gen_put_bit().
  *
  * Returns:	Number of bits sent including "flags" and the
@@ -73,8 +75,7 @@ static int number_of_bits_sent[MAX_CHANS];		// Count number of bits sent by "hdl
  *
  *--------------------------------------------------------------*/
 
-
-int hdlc_send_frame (int chan, unsigned char *fbuf, int flen)
+int hdlc_send_frame (int chan, unsigned char *fbuf, int flen, int bad_fcs)
 {
 	int j, fcs;
 	
@@ -84,7 +85,7 @@ int hdlc_send_frame (int chan, unsigned char *fbuf, int flen)
 
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("hdlc_send_frame ( chan = %d, fbuf = %p, flen = %d )\n", chan, fbuf, flen);
+	dw_printf ("hdlc_send_frame ( chan = %d, fbuf = %p, flen = %d, bad_fcs = %d)\n", chan, fbuf, flen, bad_fcs);
 	fflush (stdout);
 #endif
 
@@ -97,8 +98,15 @@ int hdlc_send_frame (int chan, unsigned char *fbuf, int flen)
 
 	fcs = fcs_calc (fbuf, flen);
 
-	send_data (chan, fcs & 0xff);
-	send_data (chan, (fcs >> 8) & 0xff);
+	if (bad_fcs) {
+	  /* For testing only - Simulate a frame getting corrupted along the way. */
+	  send_data (chan, (~fcs) & 0xff);
+	  send_data (chan, ((~fcs) >> 8) & 0xff);
+	}
+	else {
+	  send_data (chan, fcs & 0xff);
+	  send_data (chan, (fcs >> 8) & 0xff);
+	}
 
 	send_control (chan, 0x7e);	/* End frame */
 

hdlc_send.h

@@ -1,7 +1,7 @@
 
 /* hdlc_send.h */
 
-int hdlc_send_frame (int chan, unsigned char *fbuf, int flen);
+int hdlc_send_frame (int chan, unsigned char *fbuf, int flen, int bad_fcs);
 
 int hdlc_send_flags (int chan, int flags, int finish);
 

igate.c

@@ -883,7 +883,7 @@ void igate_send_rec_packet (int chan, packet_t recv_pp)
 
 	if (save_digi_config_p->filter_str[chan][MAX_CHANS] != NULL) {
 
-	  if (pfilter(chan, MAX_CHANS, save_digi_config_p->filter_str[chan][MAX_CHANS], recv_pp) != 1) {
+	  if (pfilter(chan, MAX_CHANS, save_digi_config_p->filter_str[chan][MAX_CHANS], recv_pp, 1) != 1) {
 
 	    // Is this useful troubleshooting information or just distracting noise?
 	    // Originally this was always printed but there was a request to add a "quiet" option to suppress this.
@@ -1542,7 +1542,7 @@ static void xmit_packet (char *message, int to_chan)
 
 	if (save_digi_config_p->filter_str[MAX_CHANS][to_chan] != NULL) {
 
-	  if (pfilter(MAX_CHANS, to_chan, save_digi_config_p->filter_str[MAX_CHANS][to_chan], pp3) != 1) {
+	  if (pfilter(MAX_CHANS, to_chan, save_digi_config_p->filter_str[MAX_CHANS][to_chan], pp3, 1) != 1) {
 
 	    // Originally this was always printed but it's probably too much noise.
 	    // Version 1.4, print only if debug option is specified.

log.c

@@ -341,6 +341,89 @@ void log_write (int chan, decode_aprs_t *A, packet_t pp, alevel_t alevel, retry_
 
 
 
+/*------------------------------------------------------------------
+ *
+ * Function:	log_rr_bits
+ *
+ * Purpose:	Quick hack to look at the C and RR bits just to see what is there.
+ *		This seems like a good place because it is a small subset of the function above.
+ *
+ * Inputs:	A	- Explode information from APRS packet.
+ *
+ *		pp	- Received packet object.
+ *
+ *------------------------------------------------------------------*/
+
+void log_rr_bits (decode_aprs_t *A, packet_t pp)
+{
+
+	if (1) {
+
+	  char heard[AX25_MAX_ADDR_LEN+1];
+	  char smfr[60];
+	  char *p;
+	  int src_c, dst_c;
+	  int src_rr, dst_rr;
+
+	  // Sanitize system type (manufacturer) changing any comma to period.
+
+	  strlcpy (smfr, A->g_mfr, sizeof(smfr));
+	  for (p=smfr; *p!='\0'; p++) {
+	    if (*p == ',') *p = '.';
+	  }
+
+          /* Who are we hearing?   Original station or digipeater? */
+	  /* Similar code in direwolf.c.  Combine into one function? */
+
+	  strlcpy(heard, "", sizeof(heard));
+
+	  if (pp != NULL) {
+	    int h;
+
+	    if (ax25_get_num_addr(pp) == 0) {
+	      /* Not AX.25. No station to display below. */
+	      h = -1;
+	      strlcpy (heard, "", sizeof(heard));
+	    }
+	    else {
+	      h = ax25_get_heard(pp);
+              ax25_get_addr_with_ssid(pp, h, heard);
+	    }
+
+	    if (h >= AX25_REPEATER_2 &&
+	        strncmp(heard, "WIDE", 4) == 0 &&
+	        isdigit(heard[4]) &&
+	        heard[5] == '\0') {
+
+	      ax25_get_addr_with_ssid(pp, h-1, heard);
+	      strlcat (heard, "?", sizeof(heard));
+	    }
+
+	    src_c = ax25_get_h (pp, AX25_SOURCE);
+	    dst_c = ax25_get_h (pp, AX25_DESTINATION);
+	    src_rr = ax25_get_rr (pp, AX25_SOURCE);
+	    dst_rr = ax25_get_rr (pp, AX25_DESTINATION);
+
+	    // C RR	for source
+	    // C RR	for destination
+	    // system type
+	    // source
+	    // station heard
+
+	    text_color_set(DW_COLOR_INFO);
+
+	    dw_printf ("%d %d%d  %d %d%d,%s,%s,%s\n",
+			src_c, (src_rr >> 1) & 1, src_rr & 1,
+			dst_c, (dst_rr >> 1) & 1, dst_rr & 1,
+			smfr, A->g_src, heard);
+	  }
+	}
+
+} /* end log_rr_bits */
+
+
+
+
 /*------------------------------------------------------------------
  *
  * Function:	log_term

log.h

@@ -14,4 +14,6 @@ void log_init (char *path);
 
 void log_write (int chan, decode_aprs_t *A, packet_t pp, alevel_t alevel, retry_t retries);
 
+void log_rr_bits (decode_aprs_t *A, packet_t pp);
+
 void log_term (void); 	

multi_modem.c

@@ -470,7 +470,27 @@ void multi_modem_process_rec_frame (int chan, int subchan, int slice, unsigned c
 	if (save_audio_config_p->achan[chan].num_subchan == 1 &&
 	    save_audio_config_p->achan[chan].num_slicers == 1) {
 
-	  dlq_rec_frame (chan, subchan, slice, pp, alevel, retries, "");
+
+	  int drop_it = 0;
+	  if (save_audio_config_p->recv_error_rate != 0) {
+	    float r = (float)(rand()) / (float)RAND_MAX;		// Random, 0.0 to 1.0
+
+	    //text_color_set(DW_COLOR_INFO);
+	    //dw_printf ("TEMP DEBUG.  recv error rate = %d\n", save_audio_config_p->recv_error_rate);
+
+	    if (save_audio_config_p->recv_error_rate / 100.0 > r) {
+	      drop_it = 1;
+	      text_color_set(DW_COLOR_INFO);
+	      dw_printf ("Intentionally dropping incoming frame.  Recv Error rate = %d per cent.\n", save_audio_config_p->recv_error_rate);
+	    }
+	  }
+
+	  if (drop_it ) {
+	    ax25_delete (pp);
+	  }
+	  else {
+	    dlq_rec_frame (chan, subchan, slice, pp, alevel, retries, "");
+	  }
 	  return;
 	}
 
@@ -649,14 +669,34 @@ static void pick_best_candidate (int chan)
 	j = subchan_from_n(best_n);
 	k = slice_from_n(best_n);
 
-	dlq_rec_frame (chan, j, k,
+	int drop_it = 0;
+	if (save_audio_config_p->recv_error_rate != 0) {
+	  float r = (float)(rand()) / (float)RAND_MAX;		// Random, 0.0 to 1.0
+
+	  //text_color_set(DW_COLOR_INFO);
+	  //dw_printf ("TEMP DEBUG.  recv error rate = %d\n", save_audio_config_p->recv_error_rate);
+
+	  if (save_audio_config_p->recv_error_rate / 100.0 > r) {
+	    drop_it = 1;
+	    text_color_set(DW_COLOR_INFO);
+	    dw_printf ("Intentionally dropping incoming frame.  Recv Error rate = %d per cent.\n", save_audio_config_p->recv_error_rate);
+	  }
+	}
+
+	if ( drop_it ) {
+	  ax25_delete (candidate[chan][j][k].packet_p);
+	  candidate[chan][j][k].packet_p = NULL;
+	}
+	else {
+	  dlq_rec_frame (chan, j, k,
 		candidate[chan][j][k].packet_p,
 		candidate[chan][j][k].alevel,
 		(int)(candidate[chan][j][k].retries),
 		spectrum);
 
-	/* Someone else owns it now and will delete it later. */
-	candidate[chan][j][k].packet_p = NULL;
+	  /* Someone else owns it now and will delete it later. */
+	  candidate[chan][j][k].packet_p = NULL;
+	}
 
 	/* Clear in preparation for next time. */
 

pfilter.c

@@ -81,9 +81,15 @@ typedef struct pfstate_s {
 	packet_t pp;
 
 /*
- * Packet split into separate parts.
+ * Are we processing APRS or connected mode?
+ * This determines whch types of filters are available.
+ */
+	int is_aprs;
+
+/*
+ * Packet split into separate parts if APRS.
  * Most interesting fields are:
- *		g_src		- source address
+ *
  *		g_symbol_table	- / \ or overlay
  *		g_symbol_code
  *		g_lat, g_lon	- Location
@@ -133,6 +139,10 @@ static int filt_s (pfstate_t *pf);
  *
  *		pp	- Packet object handle.
  *
+ *		is_aprs	- True for APRS, false for connected mode digipeater.
+ *			  Connected mode allows a subset of the filter types, only
+ *			  looking at the addresses, not information part contents.
+ *
  * Returns:	 1 = yes
  *		 0 = no
  *		-1 = error detected
@@ -142,7 +152,7 @@ static int filt_s (pfstate_t *pf);
  *
  *--------------------------------------------------------------------*/
 
-int pfilter (int from_chan, int to_chan, char *filter, packet_t pp)
+int pfilter (int from_chan, int to_chan, char *filter, packet_t pp, int is_aprs)
 {
 	pfstate_t pfstate;
 	char *p;
@@ -151,6 +161,8 @@ int pfilter (int from_chan, int to_chan, char *filter, packet_t pp)
 	assert (from_chan >= 0 && from_chan <= MAX_CHANS);
 	assert (to_chan >= 0 && to_chan <= MAX_CHANS);
 
+	memset (&pfstate, 0, sizeof(pfstate));
+
 	if (pp == NULL) {
 	  text_color_set(DW_COLOR_DEBUG);
 	  dw_printf ("INTERNAL ERROR in pfilter: NULL packet pointer. Please report this!\n");
@@ -165,10 +177,9 @@ int pfilter (int from_chan, int to_chan, char *filter, packet_t pp)
 	pfstate.from_chan = from_chan;
 	pfstate.to_chan = to_chan;
 
-	/* Copy filter string, removing any control characters. */
+	/* Copy filter string, changing any control characers to spaces. */
 
-	memset (pfstate.filter_str, 0, sizeof(pfstate.filter_str));
-	strncpy (pfstate.filter_str, filter, MAX_FILTER_LEN-1);
+	strlcpy (pfstate.filter_str, filter, sizeof(pfstate.filter_str));
 
 	pfstate.nexti = 0;
 	for (p = pfstate.filter_str; *p != '\0'; p++) {
@@ -178,7 +189,11 @@ int pfilter (int from_chan, int to_chan, char *filter, packet_t pp)
 	}
 
 	pfstate.pp = pp;
-	decode_aprs (&pfstate.decoded, pp, 1);	
+	pfstate.is_aprs = is_aprs;
+
+	if (is_aprs) {
+	  decode_aprs (&pfstate.decoded, pp, 1);
+	}
 
 	next_token(&pfstate);
 	
@@ -415,6 +430,14 @@ static int parse_primary (pfstate_t *pf)
  *		 0 = no
  *		-1 = error detected
  *
+ * Description:	All filter specifications are allowed for APRS.
+ *		Only those dealing with addresses are allowed for connected digipeater.
+ *
+ *		b	- budlist (source)
+ *		d	- digipeaters used
+ *		v	- digipeaters not used
+ *		u	- unproto (destination)
+ *
  *--------------------------------------------------------------------*/
 
 
@@ -424,6 +447,16 @@ static int parse_filter_spec (pfstate_t *pf)
 	int result = -1;
 	char addr[AX25_MAX_ADDR_LEN];
 
+
+	if ( ( ! pf->is_aprs) && strchr ("01bdvu", pf->token_str[0]) == NULL) {
+
+	  print_error (pf, "Only b, d, v, and u specifications are allowed for connected mode digipeater filtering.");
+	  result = -1;
+	  next_token (pf);
+	  return (result);
+	}
+
+
 /* undocumented: can use 0 or 1 for testing. */
 
 	if (strcmp(pf->token_str, "0") == 0) {
@@ -437,7 +470,8 @@ static int parse_filter_spec (pfstate_t *pf)
 
 	else if (pf->token_str[0] == 'b' && ispunct(pf->token_str[1])) {
 	  /* Budlist - source address */
-	  result = filt_bodgu (pf, pf->decoded.g_src);
+	  ax25_get_addr_with_ssid (pf->pp, AX25_SOURCE, addr);
+	  result = filt_bodgu (pf, addr);
 	}
 	else if (pf->token_str[0] == 'o' && ispunct(pf->token_str[1])) {
 	  /* Object or item name */
@@ -479,7 +513,7 @@ static int parse_filter_spec (pfstate_t *pf)
 	}
 	else if (pf->token_str[0] == 'u' && ispunct(pf->token_str[1])) {
 	  /* Unproto (destination) - probably want to exclude mic-e types */
-	  /* because destintation is used for part of location. */
+	  /* because destination is used for part of location. */
 
 	  if (ax25_get_dti(pf->pp) != '\'' && ax25_get_dti(pf->pp) != '`') {
 	    ax25_get_addr_with_ssid (pf->pp, AX25_DESTINATION, addr);
@@ -1120,7 +1154,7 @@ static void pftest (int test_num, char *filter, char *monitor, int expected)
 	pp = ax25_from_text (monitor, 1);
 	assert (pp != NULL);
 
-	result = pfilter (0, 0, filter, pp);
+	result = pfilter (0, 0, filter, pp, 1);
 	if (result != expected) {
 	  text_color_set (DW_COLOR_ERROR);
 	  dw_printf ("Unexpected result for test number %d\n", test_num);

pfilter.h

@@ -1,6 +1,6 @@
 
 /* pfilter.h */
 
-int pfilter (int from_chan, int to_chan, char *filter, packet_t pp);
+int pfilter (int from_chan, int to_chan, char *filter, packet_t pp, int is_aprs);
 
 int is_telem_metadata (char *infop);

ptt.c

@@ -46,6 +46,8 @@
  *
  * Version 1.3:	HAMLIB support.
  *
+ * Version 1.4:	The spare "future" indicator is now used when connected to another station.
+ *
  * References:	http://www.robbayer.com/files/serial-win.pdf
  *
  *		https://www.kernel.org/doc/Documentation/gpio.txt
@@ -127,6 +129,7 @@ typedef int HANDLE;
 #include "textcolor.h"
 #include "audio.h"
 #include "ptt.h"
+#include "dlq.h"
 
 
 #if __WIN32__
@@ -372,7 +375,7 @@ void ptt_init (struct audio_s *audio_config_p)
 
 	strlcpy (otnames[OCTYPE_PTT], "PTT", sizeof(otnames[OCTYPE_PTT]));
 	strlcpy (otnames[OCTYPE_DCD], "DCD", sizeof(otnames[OCTYPE_DCD]));
-	strlcpy (otnames[OCTYPE_FUTURE], "FUTURE", sizeof(otnames[OCTYPE_FUTURE]));
+	strlcpy (otnames[OCTYPE_CON], "CON", sizeof(otnames[OCTYPE_CON]));
 
 
 	for (ch = 0; ch < MAX_CHANS; ch++) {
@@ -773,7 +776,7 @@ void ptt_init (struct audio_s *audio_config_p)
  *		probably be renamed something like octrl_set.
  *
  * Inputs:	ot		- Output control type:
- *				   OCTYPE_PTT, OCTYPE_DCD, OCTYPE_HAMLIB, OCTYPE_FUTURE
+ *				   OCTYPE_PTT, OCTYPE_DCD, OCTYPE_FUTURE
  *
  *		chan		- channel, 0 .. (number of channels)-1
  *
@@ -810,6 +813,13 @@ void ptt_set (int ot, int chan, int ptt_signal)
 	  return;
 	}
 
+/*
+ * The data link state machine has an interest in activity on the radio channel.
+ * This is a very convenient place to get that information.
+ */
+
+	dlq_channel_busy (chan, ot, ptt_signal);
+
 /* 
  * Inverted output? 
  */

recv.c

@@ -68,7 +68,7 @@
  *
  *					The difference is that app_process_rec_frame
  *					is no longer called directly.  Instead
- *					the frame is appended to a queue with dlq_append.
+ *					the frame is appended to a queue with dlq_rec_frame.
  *
  *					Received frames can now be processed one at 
  *					a time and we don't need to worry about later
@@ -107,9 +107,8 @@
 #include "dtmf.h"
 #include "aprs_tt.h"
 #include "dtime_now.h"
-#if NEW14
 #include "ax25_link.h"
-#endif
+
 
 #if __WIN32__
 static unsigned __stdcall recv_adev_thread (void *arg);
@@ -266,7 +265,7 @@ static void * recv_adev_thread (void *arg)
 	  }
 
 		/* When a complete frame is accumulated, */
-		/* dlq_append, is called. */
+		/* dlq_rec_frame, is called. */
 
 		/* recv_process, below, drains the queue. */
 
@@ -293,15 +292,11 @@ void recv_process (void)
 	while (1) {
 
 	  int timed_out;
-#if NEW14
+
 	  double timeout_value =  ax25_link_get_next_timer_expiry();
 
-
 	  timed_out = dlq_wait_while_empty (timeout_value);
-#else
-	  dlq_wait_while_empty (0.0);
-	  timed_out = 0;
-#endif
+
 
 #if DEBUG
 	  text_color_set(DW_COLOR_DEBUG);
@@ -315,9 +310,7 @@ void recv_process (void)
 	    dw_printf ("recv_process: time waiting on dlq.  call dl_timer_expiry.\n");
 #endif
 
-#if NEW14
 	    dl_timer_expiry ();
-#endif
 	  }
 	  else {
 
@@ -345,17 +338,16 @@ void recv_process (void)
  */
 
 		  app_process_rec_packet (pitem->chan, pitem->subchan, pitem->slice, pitem->pp, pitem->alevel, pitem->retries, pitem->spectrum);
-	          pitem->pp = NULL;  // Was consumed by above.  Don't try to use or free again.
 
 
 /*
- * Link processing - Can ignore UI frames.
+ * Link processing.
  */
-	// TODO - ax25_link_rec_frame  & delete & remove delete from above.
+	          lm_data_indication(pitem);
 
 	          break;
 
-#if NEW14
+
 	        case DLQ_CONNECT_REQUEST:
 
 	          dl_connect_request (pitem);
@@ -370,7 +362,27 @@ void recv_process (void)
 
 	          dl_data_request (pitem);
 	          break;
-#endif
+
+	        case DLQ_REGISTER_CALLSIGN:
+
+	          dl_register_callsign (pitem);
+	          break;
+
+	        case DLQ_UNREGISTER_CALLSIGN:
+
+	          dl_unregister_callsign (pitem);
+	          break;
+
+		case DLQ_CHANNEL_BUSY:
+
+	          lm_channel_busy (pitem);
+	          break;
+
+	        case DLQ_CLIENT_CLEANUP:
+
+	          dl_client_cleanup (pitem);
+	          break;
+
 	      }
 
 	      dlq_delete (pitem);

serial_port.c

@@ -184,6 +184,10 @@ MYFDTYPE serial_port_open (char *devicename, int baud)
 	//text_color_set(DW_COLOR_INFO);
 	//dw_printf("Successful serial port open on %s.\n", devicename);
 
+	// Some devices, e.g. KPC-3+, can't turn off hardware flow control and need RTS.
+
+	EscapeCommFunction(fd,SETRTS);
+	EscapeCommFunction(fd,SETDTR);
 #else
 
 /* Linux version. */

server.c

@@ -179,23 +179,6 @@ static int enable_send_monitor_to_client[MAX_NET_CLIENTS];
 					/* the client app must send a command to enable this. */
 
 
-/*
- * Registered callsigns from 'X' command.
- * For simplicity just use a fixed size array until there
- * is evidence that a larger number would be needed.
- *
- * Also keep track of which client did the registration.
- * For example client 0 might register the callsign ABC
- * and client 1 register DEF.   If something comes addressed
- * to DEF, we would want it going only to client 1.
- */
-
-#define MAX_REG_CALLSIGNS 20
-
-static char registered_callsigns[MAX_REG_CALLSIGNS][AX25_MAX_ADDR_LEN];
-static int registered_by_client[MAX_REG_CALLSIGNS];
-
-
 // TODO:  define in one place, use everywhere.
 // TODO:  Macro to terminate thread when no point to go on.
 
@@ -464,8 +447,6 @@ void server_init (struct audio_s *audio_config_p, struct misc_config_s *mc)
 	  enable_send_monitor_to_client[client] = 0;
 	}
 
-	memset (registered_callsigns, 0, sizeof(registered_callsigns));
-
 	if (server_port == 0) {
 	  text_color_set(DW_COLOR_INFO);
 	  dw_printf ("Disabled AGW network client port.\n");
@@ -653,6 +634,7 @@ static THREAD_F connect_listen_thread (void *arg)
             }
 
 	    text_color_set(DW_COLOR_INFO);
+// TODO: "attached" or some other term would be better because "connected" has a different meaning for AX.25.
 	    dw_printf("\nConnected to AGW client application %d ...\n\n", client);
 
 /*
@@ -836,6 +818,7 @@ void server_send_rec_packet (int chan, packet_t pp, unsigned char *fbuf,  int fl
 	      closesocket (client_sock[client]);
 	      client_sock[client] = -1;
 	      WSACleanup();
+	      dlq_client_cleanup (client);
 	    }
 #else
             err = write (client_sock[client], &agwpe_msg, sizeof(agwpe_msg.hdr) + netle2host(agwpe_msg.hdr.data_len_NETLE));
@@ -845,6 +828,7 @@ void server_send_rec_packet (int chan, packet_t pp, unsigned char *fbuf,  int fl
 	      dw_printf ("\nError sending message to AGW client application.  Closing connection.\n\n");
 	      close (client_sock[client]);
 	      client_sock[client] = -1;    
+	      dlq_client_cleanup (client);
 	    }
 #endif
 	  }
@@ -939,6 +923,7 @@ void server_send_rec_packet (int chan, packet_t pp, unsigned char *fbuf,  int fl
 	      closesocket (client_sock[client]);
 	      client_sock[client] = -1;
 	      WSACleanup();
+	      dlq_client_cleanup (client);
 	    }
 #else
             err = write (client_sock[client], &agwpe_msg, sizeof(agwpe_msg.hdr) + netle2host(agwpe_msg.hdr.data_len_NETLE));
@@ -948,6 +933,7 @@ void server_send_rec_packet (int chan, packet_t pp, unsigned char *fbuf,  int fl
 	      dw_printf ("\nError sending message to AGW client application %d.  Closing connection.\n\n", client);
 	      close (client_sock[client]);
 	      client_sock[client] = -1;
+	      dlq_client_cleanup (client);
 	    }
 #endif
 	  }
@@ -964,6 +950,8 @@ void server_send_rec_packet (int chan, packet_t pp, unsigned char *fbuf,  int fl
  * Purpose:     Send notification to client app when a link has
  *		been established with another station.
  *
+ *		DL-CONNECT Confirm or DL-CONNECT Indication in the protocol spec.
+ *
  * Inputs:	chan		- Which radio channel.
  *
  * 		client		- Which one of potentially several clients.
@@ -1017,6 +1005,8 @@ void server_link_established (int chan, int client, char *remote_call, char *own
  *		another station has been terminated or a connection
  *		attempt failed.
  *
+ *		DL-DISCONNECT Confirm or DL-DISCONNECT Indication in the protocol spec.
+ *
  * Inputs:	chan		- Which radio channel.
  *
  * 		client		- Which one of potentially several clients.
@@ -1027,7 +1017,7 @@ void server_link_established (int chan, int client, char *remote_call, char *own
  *
  *		timeout		- true when no answer from other station.
  *				  How do we distinguish who asked for the
- *				  termination of an existing linkn?
+ *				  termination of an existing link?
  *
  *--------------------------------------------------------------------*/
 
@@ -1060,6 +1050,66 @@ void server_link_terminated (int chan, int client, char *remote_call, char *own_
 } /* end server_link_terminated */
 
 
+/*-------------------------------------------------------------------
+ *
+ * Name:        server_rec_conn_data
+ *
+ * Purpose:     Send received connected data to the application.
+ *
+ *		DL-DATA Indication in the protocol spec.
+ *
+ * Inputs:	chan		- Which radio channel.
+ *
+ * 		client		- Which one of potentially several clients.
+ *
+ *		remote_call	- Callsign[-ssid] of remote station.
+ *
+ *		own_call	- Callsign[-ssid] of my end.
+ *
+ *		pid		- Protocol ID from I frame.
+ *
+ *		data_ptr	- Pointer to a block of bytes.
+ *
+ *		data_len	- Number of bytes.  Could be zero.
+ *
+ *--------------------------------------------------------------------*/
+
+void server_rec_conn_data (int chan, int client, char *remote_call, char *own_call, int pid, char *data_ptr, int data_len)
+{
+
+	struct {
+	  struct agwpe_s hdr;
+	  char info[AX25_MAX_INFO_LEN];		// I suppose there is potential for something larger.
+						// We'll cross that bridge if we ever come to it.
+	} reply;
+
+
+	memset (&reply.hdr, 0, sizeof(reply.hdr));
+	reply.hdr.portx = chan;
+	reply.hdr.datakind = 'D';
+	reply.hdr.pid = pid;
+
+	strlcpy (reply.hdr.call_from, remote_call, sizeof(reply.hdr.call_from));
+	strlcpy (reply.hdr.call_to,   own_call,    sizeof(reply.hdr.call_to));
+
+	if (data_len < 0) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("Invalid length %d for connected data to client %d.\n", data_len, client);
+	  data_len = 0;
+	}
+	else if (data_len > AX25_MAX_INFO_LEN) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("Invalid length %d for connected data to client %d.\n", data_len, client);
+	  data_len = AX25_MAX_INFO_LEN;
+	}
+
+	memcpy (reply.info, data_ptr, data_len);
+	reply.hdr.data_len_NETLE = host2netle(data_len);
+
+	send_to_client (client, &reply);
+
+} /* end server_rec_conn_data */
+
 
 /*-------------------------------------------------------------------
  *
@@ -1199,6 +1249,7 @@ static THREAD_F cmd_listen_thread (void *arg)
 	    close (client_sock[client]);
 #endif
 	    client_sock[client] = -1;
+	    dlq_client_cleanup (client);
 	    continue;
 	  }
 
@@ -1240,6 +1291,7 @@ static THREAD_F cmd_listen_thread (void *arg)
 	    close (client_sock[client]);
 #endif
 	    client_sock[client] = -1;
+	    dlq_client_cleanup (client);
 	    return (0);
 	  }
 
@@ -1258,6 +1310,7 @@ static THREAD_F cmd_listen_thread (void *arg)
 	      close (client_sock[client]);
 #endif
 	      client_sock[client] = -1;
+	      dlq_client_cleanup (client);
 	      return (0);
 	    }
 	    if (n >= 0) {
@@ -1581,38 +1634,34 @@ static THREAD_F cmd_listen_thread (void *arg)
 	      {
 		struct {
 		  struct agwpe_s hdr;
-		  char data;
+		  char data;			/* 1 = success, 0 = failure */
 		} reply;
 
-		int j, ok;
+		int ok = 1;
+
+		// The protocol spec says it is an error to register the same one more than once.
+	        // Too much trouble.  Report success if the channel is valid.
+
+
+	        int chan = cmd.hdr.portx;
+
+		if (chan >= 0 && chan < MAX_CHANS && save_audio_config_p->achan[chan].valid) {
+		  ok = 1;
+	          dlq_register_callsign (cmd.hdr.call_from, chan, client);
+	        }
+	        else {
+	          text_color_set(DW_COLOR_ERROR);
+	          dw_printf ("AGW protocol error.  Register callsign for invalid channel %d.\n", chan);
+	          ok = 0;
+	        }
+
 
 	        memset (&reply, 0, sizeof(reply));
 	        reply.hdr.datakind = 'X';
+	        reply.hdr.portx = cmd.hdr.portx;
 		memcpy (reply.hdr.call_from, cmd.hdr.call_from, sizeof(reply.hdr.call_from));
 	        reply.hdr.data_len_NETLE = host2netle(1);
-	
-		// Version 1.0.
-		// Previously used sizeof(reply) but compiler rounded it up to next byte boundary.
-		// That's why more cumbersome size expression is used.
-
-		// The protocol spec says it is an error to register the same one more than once.
-	        // First make sure is it not already in there.  Add if space available.
-
-	        if (server_callsign_registered_by_client(cmd.hdr.call_from) >= 0) {
-	          ok = 0;
-	        }
-	        else {
-	          ok = 0;
-	          for (j = 0; j < MAX_REG_CALLSIGNS && ok == 0; j++) {
-	            if (registered_callsigns[j][0] == '\0') {
-	              strlcpy (registered_callsigns[j], cmd.hdr.call_from, sizeof(registered_callsigns[j]));
-	              registered_by_client[j] = client;
-	              ok = 1;
-	            }
-	          }
-	        }
-
-		reply.data = ok;		/* 1 = success, 0 = failure */
+		reply.data = ok;
 	        send_to_client (client, &reply);
 	      }
 	      break;
@@ -1620,13 +1669,15 @@ static THREAD_F cmd_listen_thread (void *arg)
 	    case 'x':				/* Unregister CallSign  */
 
 	      {
-	        int j;
 
-	        for (j = 0; j < MAX_REG_CALLSIGNS; j++) {
-	          if (strcmp(registered_callsigns[j], cmd.hdr.call_from) == 0) {
-	            registered_callsigns[j][0] = '\0';
-	            registered_by_client[j] = -1;
-	          }
+	        int chan = cmd.hdr.portx;
+
+		if (chan >= 0 && chan < MAX_CHANS && save_audio_config_p->achan[chan].valid) {
+	          dlq_unregister_callsign (cmd.hdr.call_from, chan, client);
+	        }
+		else {
+	          text_color_set(DW_COLOR_ERROR);
+	          dw_printf ("AGW protocol error.  Unregister callsign for invalid channel %d.\n", chan);
 	        }
 	      }
 	      /* No reponse is expected. */
@@ -1648,7 +1699,7 @@ static THREAD_F cmd_listen_thread (void *arg)
 		int j;
 
 	        strlcpy (callsigns[AX25_SOURCE], cmd.hdr.call_from, sizeof(callsigns[AX25_SOURCE]));
-	        strlcpy (callsigns[AX25_DESTINATION], cmd.hdr.call_to, sizeof(callsigns[AX25_SOURCE]));
+	        strlcpy (callsigns[AX25_DESTINATION], cmd.hdr.call_to, sizeof(callsigns[AX25_DESTINATION]));
 
 	        if (cmd.hdr.datakind == 'c') {
 	          pid = cmd.hdr.pid;		/* non standard for NETROM, TCP/IP, etc. */
@@ -1675,15 +1726,9 @@ static THREAD_F cmd_listen_thread (void *arg)
 	          }
 	        }
 
-#if NEW14
+
 	        dlq_connect_request (callsigns, num_calls, cmd.hdr.portx, client, pid);
-#else
-		(void)pid;	// suppress unused variable message.
-	        text_color_set(DW_COLOR_ERROR);
-	        dw_printf ("\n");
-	        dw_printf ("Can't process command '%c' from AGW client app %d.\n", cmd.hdr.datakind, client);
-	        dw_printf ("Connected packet mode is not implemented.\n");
-#endif
+
 	      }
 	      break;
 
@@ -1696,15 +1741,9 @@ static THREAD_F cmd_listen_thread (void *arg)
 
 	        strlcpy (callsigns[AX25_SOURCE], cmd.hdr.call_from, sizeof(callsigns[AX25_SOURCE]));
 	        strlcpy (callsigns[AX25_DESTINATION], cmd.hdr.call_to, sizeof(callsigns[AX25_SOURCE]));
-#if NEW14
+
 	        dlq_xmit_data_request (callsigns, num_calls, cmd.hdr.portx, client, cmd.hdr.pid, cmd.data, netle2host(cmd.hdr.data_len_NETLE));
-#else
-		(void)num_calls;	// suppress unused variable warning.
-	        text_color_set(DW_COLOR_ERROR);
-	        dw_printf ("\n");
-	        dw_printf ("Can't process command '%c' from AGW client app %d.\n", cmd.hdr.datakind, client);
-	        dw_printf ("Connected packet mode is not implemented.\n");
-#endif
+
 	      }
 	      break;
 
@@ -1716,15 +1755,9 @@ static THREAD_F cmd_listen_thread (void *arg)
 
 	        strlcpy (callsigns[AX25_SOURCE], cmd.hdr.call_from, sizeof(callsigns[AX25_SOURCE]));
 	        strlcpy (callsigns[AX25_DESTINATION], cmd.hdr.call_to, sizeof(callsigns[AX25_SOURCE]));
-#if NEW14
+
 	        dlq_disconnect_request (callsigns, num_calls, cmd.hdr.portx, client);
-#else
-		(void)num_calls;	// suppress unused variable warning.
-	        text_color_set(DW_COLOR_ERROR);
-	        dw_printf ("\n");
-	        dw_printf ("Can't process command '%c' from AGW client app %d.\n", cmd.hdr.datakind, client);
-	        dw_printf ("Connected packet mode is not implemented.\n");
-#endif
+
 	      }
 	      break;
 
@@ -1839,30 +1872,4 @@ static THREAD_F cmd_listen_thread (void *arg)
 } /* end send_to_client */
 
 
-/*-------------------------------------------------------------------
- *
- * Name:        server_callsign_registered_by_client
- *
- * Purpose:     See if given callsign was registered.
- *
- * Inputs:	callsign
- *
- * Returns:	>= 0 for the client number.
- *		-1 for not found.
- *
- *--------------------------------------------------------------------*/
-
-int server_callsign_registered_by_client (char *callsign)
-{
-	int j;
-
-	for (j = 0; j < MAX_REG_CALLSIGNS; j++) {
-	  if (strcmp(registered_callsigns[j], callsign) == 0) {
-	    return (registered_by_client[j]);
-	  }
-	}
-	return (-1);
-
-} /* end server_callsign_registered_by_client */
-
 /* end server.c */

server.h

@@ -22,5 +22,7 @@ void server_link_established (int chan, int client, char *remote_call, char *own
 
 void server_link_terminated (int chan, int client, char *remote_call, char *own_call, int timeout);
 
+void server_rec_conn_data (int chan, int client, char *remote_call, char *own_call, int pid, char *data_ptr, int data_len);
+
 
 /* end server.h */

symbols-new.txt

@@ -1,4 +1,4 @@
-APRS SYMBOL OVERLAY and EXTENSION TABLES in APRS 1.2      22 Mar 2016
+APRS SYMBOL OVERLAY and EXTENSION TABLES in APRS 1.2      18 Oct 2016
 ---------------------------------------------------------------------
 
 BACKGROUND:  This file addresses new additions proposals (OVERLAYS) 
@@ -7,6 +7,9 @@ document remains on the www.aprs.org/symbols/symbolsX.txt page, but
 only has one line per symbol character.  Since each of the symbols
 can have up to 36 overlays, this gives us thousands of symbols codes.
 
+18 Oct 2016:  Added Green, Yellow, Red for Flood gaures using G,Y,R
+              overlays + N for Normal. (on existing H2O symbol)
+              Added DIGIPEATERS
 22 Mar 2016:  Added A0 overlay circle for ALSTAR nodes 
               and V0 for VOIP combined echolink and IRLP
               and P& for PSKmail node
@@ -226,6 +229,19 @@ BD = Bus Depot (new Aug 2014)
 LD = LIght Rail or Subway (new Aug 2014)
 SD = Seaport Depot (new Aug 2014)
 
+DIGIPEATERS
+/# - Generic digipeater
+1# - WIDE1-1 digipeater
+A# - Alternate input (i.e. 144.990MHz) digipeater
+E# - Emergency powered (assumed full normal digi)
+I# - I-gate equipped digipeater
+L# - WIDEn-N with path length trapping
+P# - PacComm
+S# - SSn-N digipeater (includes WIDEn-N)
+X# - eXperimental digipeater
+V# - Viscous https://github.com/PhirePhly/aprx/blob/master/ViscousDigipeater.README
+W# - WIDEn-N, SSn-N and Trapping
+
 EMERGENCY: #!
 /! = Police/Sheriff, etc
 \! = Emergency!
@@ -389,6 +405,18 @@ Tu = Tanker
 Cu = Chlorine Tanker
 Hu = Hazardous
 
+WATER #w
+/w = Water Station or other H2O
+\w = flooding (or Avalanche/slides)
+Aw = Avalanche
+Gw = Green Flood Gauge
+Mw = Mud slide
+Nw = Normal flood gauge (blue)
+Rw = Red flood gauge
+Sw = Snow Blockage
+Yw = Yellow flood gauge
+
+
 
 Anyone can use any overlay on any of the overlayable symbols for any
 special purpose.  We are not trying to document all possible such

tocalls.txt

@@ -1,6 +1,10 @@
-APRS TO-CALL VERSION NUMBERS                            29 Apr 2016
+APRS TO-CALL VERSION NUMBERS                            14 Nov 2016
 -------------------------------------------------------------------
                                                              WB4APR
+14 Nov 16 Added APINxx for PinPoint by AB0WV
+09 Nov 16 added APNICx for SQ5EKU http://sq5eku.blogspot.com/
+24 Oct 16 added APTKPT TrackPoint N0LP, removed APZTKP
+24 Aug 16 added APK004 for Kenwood THD-74
 29 Apr 16 added APFPRS for FreeDV by Jeroen PE1RXQ
 25 Feb 16 Added APCDS0 for Leon Lessing ZS6LMG's cell tracker
 21 Jan 16 added APDNOx for APRSduino by DO3SWW
@@ -12,12 +16,7 @@ APRS TO-CALL VERSION NUMBERS                            29 Apr 2016
 27 Apr 15 added APZMAJ for Martyn M1MAJ DeLorme inReach Tracker
 21 Apr 15 added APB2MF & APR2MF DL2MF - MF2APRS Radiosonde   
 06 Apr 15 added APAVT5 SainSonic AP510 - a 1watt tracker 
-13 Mar 14 added APECAN Pecan Pico APRS Balloon Tracker
-02 Sep 14 added APSTMx W7QO's Balloon trackers
-21 Aug 14 added APSMSx Paul Defrusne's SMS gateway
-11 Aug 14 added APCWP8 John GM7HHB, WinphoneAPRS
-18 Dec 13 added APZWKR GM1WKR NetSked application
-
+. . . . . ...
 11 Jan 12 added APYTxx for YagTracker and updated Yaesu APY008/350
 
 In APRS, the AX.25  Destination address is not used for packet 
@@ -86,6 +85,7 @@ a TOCALL number series:
       APHTxx  HMTracker by IU0AAC 
  API  APICQx  for ICQ
       APICxx  for HA9MCQ Pic IGate
+      APINxx for PinPoint by AB0WV
  APJ  APJAxx  JavAPRS
       APJExx  JeAPRS
       APJIxx  jAPRSIgate
@@ -93,6 +93,7 @@ a TOCALL number series:
       APJYnn  KA2DDO Yet another APRS system
  APK  APK0xx  Kenwood TH-D7's
       APK003  Kenwood TH-D72
+      APK004  Kenwood TH-D74
       APK1xx  Kenwood D700's
       APK102  Kenwood D710
       APKRAM  KRAMstuff.com - Mark. G7LEU
@@ -107,6 +108,7 @@ a TOCALL number series:
       APN9xx  Kantronics KPC-9612 Roms
       APNAxx  WB6ZSU's APRServe
       APNDxx  DIGI_NED
+      APNICx  SQ5EKU http://sq5eku.blogspot.com/
       APNK01  Kenwood D700 (APK101) type
       APNK80  KAM version 8.0
       APNKMP  KAM+
@@ -144,14 +146,15 @@ a TOCALL number series:
       APSCxx  aprsc APRS-IS core server (OH7LZB, OH2MQK)
       APSK63  APRS Messenger -over-PSK63
       APSK25  APRS Messenger GMSK-250
-      APSMSx  Paul Defrusne's SMS gateway
+      APSMSx  Paul Dufresne's SMSGTE - SMS Gateway
       APSTMx  for W7QO's Balloon trackers
       APSTPO  for N0AGI Satellite Tracking and Operations
- APT  APTIGR  TigerTrack
-      APTTxx  Tiny Track
-      APT2xx  Tiny Track II
+ APT  APT2xx  Tiny Track II
       APT3xx  Tiny Track III
       APTAxx  K4ATM's tiny track
+      APTIGR  TigerTrack
+      APTKPT  TrackPoint N0LP
+      APTTxx  Tiny Track
       APTWxx  Byons WXTrac
       APTVxx  for ATV/APRN and SSTV applications
  APU  APU1xx  UIview 16 bit applications
@@ -179,7 +182,7 @@ a TOCALL number series:
       APZMAJ  Martyn M1MAJ DeLorme inReach Tracker
       APZMDR  for HaMDR trackers - hessu * hes.iki.fi]
       APZPAD  Smart Palm 
-      APZTKP  TrackPoint, Nick N0LP (Balloon tracking)
+      APZTKP  TrackPoint, Nick N0LP (Balloon tracking)(depricated)
       APZWIT  MAP27 radio (Mountain Rescue) EI7IG
       APZWKR  GM1WKR NetSked application
 

tq.c

@@ -1,7 +1,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2011, 2012, 2014, 2015  John Langner, WB2OSZ
+//    Copyright (C) 2011, 2012, 2014, 2015, 2016  John Langner, WB2OSZ
 //
 //    This program is free software: you can redistribute it and/or modify
 //    it under the terms of the GNU General Public License as published by
@@ -35,6 +35,8 @@
  *
  *---------------------------------------------------------------*/
 
+#define TQ_C 1
+
 #include "direwolf.h"
 
 #include <stdio.h>
@@ -120,7 +122,7 @@ void tq_init (struct audio_s *audio_config_p)
 
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("tq_init ( %d )\n", nchan);
+	dw_printf ("tq_init (  )\n");
 #endif
 
 	save_audio_config_p = audio_config_p;
@@ -187,11 +189,14 @@ void tq_init (struct audio_s *audio_config_p)
  *
  * Name:        tq_append
  *
- * Purpose:     Add a packet to the end of the specified transmit queue.
+ * Purpose:     Add an APRS packet to the end of the specified transmit queue.
+ *
+ * 		Connected mode is a little different.  Use lm_data_request instead.
  *
  * Inputs:	chan	- Channel, 0 is first.
  *
- *		prio	- Priority, use TQ_PRIO_0_HI or TQ_PRIO_1_LO.
+ *		prio	- Priority, use TQ_PRIO_0_HI for digipeated or
+ *				TQ_PRIO_1_LO for normal.
  *
  *		pp	- Address of packet object.
  *				Caller should NOT make any references to
@@ -218,8 +223,11 @@ void tq_append (int chan, int prio, packet_t pp)
 
 
 #if DEBUG
+	unsigned char *pinfo;
+	int info_len = ax25_get_info (pp, &pinfo);
+	if (info_len > 10) info_len = 10;
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("tq_append (chan=%d, prio=%d, pp=%p)\n", chan, prio, pp);
+	dw_printf ("tq_append (chan=%d, prio=%d, pp=%p) \"%*s\"\n", chan, prio, pp, info_len, (char*)pinfo);
 #endif
 
 
@@ -242,6 +250,8 @@ void tq_append (int chan, int prio, packet_t pp)
 	if (chan < 0 || chan >= MAX_CHANS || ! save_audio_config_p->achan[chan].valid) {
 	  text_color_set(DW_COLOR_ERROR);
 	  dw_printf ("ERROR - Request to transmit on invalid radio channel %d.\n", chan);
+	  dw_printf ("This is probably a client application error, not a problem with direwolf.\n");
+	  dw_printf ("AX.25 for Linux is known to transmit on channels 2 & 8 sometimes when it shouldn't.\n");
 	  ax25_delete(pp);
 	  return;
 	}
@@ -286,14 +296,6 @@ void tq_append (int chan, int prio, packet_t pp)
 
 	dw_mutex_lock (&tq_mutex);
 
-//	was_empty = 1;
-//	for (c=0; c<tq_num_channels; c++) {
-//	  for (p=0; p<TQ_NUM_PRIO; p++) {
-//	    if (queue_head[c][p] != NULL)
-//	       was_empty = 0;
-//	  }
-//	}
-
 	if (queue_head[chan][prio] == NULL) {
 	  queue_head[chan][prio] = pp;
 	}
@@ -334,7 +336,340 @@ void tq_append (int chan, int prio, packet_t pp)
 	}
 #endif
 
-}
+} /* end tq_append */
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        lm_data_request
+ *
+ * Purpose:     Add an AX.25 frame to the end of the specified transmit queue.
+ *
+ *		Use tq_append instead for APRS.
+ *
+ * Inputs:	chan	- Channel, 0 is first.
+ *
+ *		prio	- Priority, use TQ_PRIO_0_HI for priority (expedited)
+ *				or TQ_PRIO_1_LO for normal.
+ *
+ *		pp	- Address of packet object.
+ *				Caller should NOT make any references to
+ *				it after this point because it could
+ *				be deleted at any time.
+ *
+ * Outputs:	A packet object is added to transmit queue.
+ *
+ * Description:	5.4.
+ *
+ *		LM-DATA Request. The Data-link State Machine uses this primitive to pass
+ *		frames of any type (SABM, RR, UI, etc.) to the Link Multiplexer State Machine.
+ *
+ *		LM-EXPEDITED-DATA Request. The data-link machine uses this primitive to
+ *		request transmission of each digipeat or expedite data frame.
+ *
+ *		C2a.1
+ *
+ *		PH-DATA Request. This primitive from the Link Multiplexer State Machine
+ *		provides an AX.25 frame of any type (UI, SABM, I, etc.) that is to be transmitted. An
+ *		unlimited number of frames may be provided. If the transmission exceeds the 10-
+ *		minute limit or the anti-hogging time limit, the half-duplex Physical State Machine
+ *		automatically relinquishes the channel for use by the other stations. The
+ *		transmission is automatically resumed at the next transmission opportunity
+ *		indicated by the CSMA/p-persistence contention algorithm.
+ *
+ *		PH-EXPEDITED-DATA Request. This primitive from the Link Multiplexer State
+ *		Machine provides the AX.25 frame that is to be transmitted immediately. The
+ *		simplex Physical State Machine gives preference to priority frames over normal
+ *		frames, and will take advantage of the PRIACK window. Priority frames can be
+ *		provided by the link multiplexer at any time; a PH-SEIZE Request and subsequent
+ *		PH Release Request are not employed for priority frames.
+ *
+ *		C3.1
+ *
+ *		LM-DATA Request. This primitive from the Data-link State Machine provides a
+ *		AX.25 frame of any type (UI, SABM, I, etc.) that is to be transmitted. An unlimited
+ *		number of frames may be provided. The Link Multiplexer State Machine
+ *		accumulates the frames in a first-in, first-out queue until it is time to transmit them.
+ *
+ *		C4.2
+ *
+ *		LM-DATA Request. This primitive is used by the Data link State Machines to pass
+ *		frames of any type (SABM, RR, UI, etc.) to the Link Multiplexer State Machine.
+ *
+ *		LM-EXPEDITED-DATA Request. This primitive is used by the Data link State
+ *		Machine to pass expedited data to the link multiplexer.
+ *
+ *
+ * Implementation: Add packet to end of linked list.
+ *		Signal the transmit thread if the queue was formerly empty.
+ *
+ *		Note that we have a transmit thread each audio channel.
+ *		Two channels can share one audio output device.
+ *
+ * IMPORTANT!	Don't make an further references to the packet object after
+ *		giving it to lm_data_request.
+ *
+ *--------------------------------------------------------------------*/
+
+
+// TODO: FIXME:  this is a copy of tq_append.  Need to fine tune and explain why.
+
+
+void lm_data_request (int chan, int prio, packet_t pp)
+{
+	packet_t plast;
+	packet_t pnext;
+
+
+#if DEBUG
+	unsigned char *pinfo;
+	int info_len = ax25_get_info (pp, &pinfo);
+	if (info_len > 10) info_len = 10;
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_data_request (chan=%d, prio=%d, pp=%p) \"%*s\"\n", chan, prio, pp, info_len, (char*)pinfo);
+#endif
+
+
+	assert (prio >= 0 && prio < TQ_NUM_PRIO);
+
+	if (pp == NULL) {
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("INTERNAL ERROR:  lm_data_request NULL packet pointer. Please report this!\n");
+	  return;
+	}
+
+#if AX25MEMDEBUG
+
+	if (ax25memdebug_get()) {
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("lm_data_request (chan=%d, prio=%d, seq=%d)\n", chan, prio, ax25memdebug_seq(pp));
+	}
+#endif
+
+	if (chan < 0 || chan >= MAX_CHANS || ! save_audio_config_p->achan[chan].valid) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("ERROR - Request to transmit on invalid radio channel %d.\n", chan);
+	  ax25_delete(pp);
+	  return;
+	}
+
+/* 
+ * Is transmit queue out of control? 
+ */
+
+	if (tq_count(chan,prio) > 250) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("Warning: Transmit packet queue for channel %d is extremely long.\n", chan);
+	  dw_printf ("Perhaps the channel is so busy there is no opportunity to send.\n");
+	}
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_data_request: enter critical section\n");
+#endif
+
+	dw_mutex_lock (&tq_mutex);
+
+
+	if (queue_head[chan][prio] == NULL) {
+	  queue_head[chan][prio] = pp;
+	}
+	else {
+	  plast = queue_head[chan][prio];
+	  while ((pnext = ax25_get_nextp(plast)) != NULL) {
+	    plast = pnext;
+	  }
+	  ax25_set_nextp (plast, pp);
+	}
+
+	dw_mutex_unlock (&tq_mutex);
+
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_data_request: left critical section\n");
+#endif
+
+	// Appendix C2a, from the Ax.25 protocol spec, says that a priority frame
+	// will start transmission.  If not already transmitting, normal frames
+	// will pile up until LM-SEIZE Request starts transmission.
+
+
+// Erratum: It doesn't take long for that to fail.
+// We send SABM(e) frames to the transmit queue and the transmitter doesn't get activated.
+
+
+//NO!	if (prio == TQ_PRIO_0_HI) {
+
+#if DEBUG
+	  dw_printf ("lm_data_request (): about to wake up xmit thread.\n");
+#endif
+#if __WIN32__
+	  SetEvent (wake_up_event[chan]);
+#else
+	  if (xmit_thread_is_waiting[chan]) {
+	    int err;
+
+	    dw_mutex_lock (&(wake_up_mutex[chan]));
+
+	    err = pthread_cond_signal (&(wake_up_cond[chan]));
+	    if (err != 0) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("lm_data_request: pthread_cond_signal err=%d", err);
+	      perror ("");
+	      exit (1);
+	    }
+
+	    dw_mutex_unlock (&(wake_up_mutex[chan]));
+	  }
+#endif
+//NO!	}
+
+} /* end lm_data_request */
+
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        lm_seize_request
+ *
+ * Purpose:     Force start of transmit even if transmit queue is empty.
+ *
+ * Inputs:	chan	- Channel, 0 is first.
+ *
+ * Description:	5.4.
+ *
+ *		LM-SEIZE Request. The Data-link State Machine uses this primitive to request the
+ *		Link Multiplexer State Machine to arrange for transmission at the next available
+ *		opportunity. The Data-link State Machine uses this primitive when an
+ *		acknowledgement must be made; the exact frame in which the acknowledgement
+ *		is sent will be chosen when the actual time for transmission arrives.
+ *
+ *		C2a.1
+ *
+ *		PH-SEIZE Request. This primitive requests the simplex state machine to begin
+ *		transmitting at the next available opportunity. When that opportunity has been
+ *		identified (according to the CSMA/p-persistence algorithm included within), the
+ *		transmitter started, a parameterized window provided for the startup of a
+ *		conventional repeater (if required), and a parameterized time allowed for the
+ *		synchronization of the remote station's receiver (known as TXDELAY in most
+ *		implementations), then a PH-SEIZE Confirm primitive is returned to the link
+ *		multiplexer.
+ *
+ *		C3.1
+ *
+ *		LM-SEIZE Request. This primitive requests the Link Multiplexer State Machine to
+ *		arrange for transmission at the next available opportunity. The Data-link State
+ *		Machine uses this primitive when an acknowledgment must be made, but the exact
+ *		frame in which the acknowledgment will be sent will be chosen when the actual
+ *		time for transmission arrives. The Link Multiplexer State Machine uses the LMSEIZE
+ *		Confirm primitive to indicate that the transmission opportunity has arrived.
+ *		After the Data-link State Machine has provided the acknowledgment, the Data-link
+ *		State Machine gives permission to stop transmission with the LM Release Request
+ *		primitive.
+ *
+ *		C4.2
+ *
+ *		LM-SEIZE Request. This primitive is used by the Data link State Machine to
+ *		request the Link Multiplexer State Machine to arrange for transmission at the next
+ *		available opportunity. The Data link State Machine uses this primitive when an
+ *		acknowledgment must be made, but the exact frame in which the acknowledgment
+ *		is sent will be chosen when the actual time for transmission arrives.
+ *
+ *
+ * Implementation: Add a null frame (i.e. length of 0) to give the process a kick.
+ *		xmit.c needs to be smart enough to discard it.
+ *
+ *--------------------------------------------------------------------*/
+
+
+void lm_seize_request (int chan)
+{
+	packet_t pp;
+	int prio = TQ_PRIO_1_LO;
+
+	packet_t plast;
+	packet_t pnext;
+
+
+#if DEBUG
+	unsigned char *pinfo;
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_seize_request (chan=%d)\n", chan);
+#endif
+
+	if (chan < 0 || chan >= MAX_CHANS || ! save_audio_config_p->achan[chan].valid) {
+	  text_color_set(DW_COLOR_ERROR);
+	  dw_printf ("ERROR - Request to transmit on invalid radio channel %d.\n", chan);
+	  return;
+	}
+
+	pp = ax25_new();
+
+#if AX25MEMDEBUG
+
+	if (ax25memdebug_get()) {
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("lm_seize_request (chan=%d, seq=%d)\n", chan, ax25memdebug_seq(pp));
+	}
+#endif
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_seize_request: enter critical section\n");
+#endif
+
+	dw_mutex_lock (&tq_mutex);
+
+
+	if (queue_head[chan][prio] == NULL) {
+	  queue_head[chan][prio] = pp;
+	}
+	else {
+	  plast = queue_head[chan][prio];
+	  while ((pnext = ax25_get_nextp(plast)) != NULL) {
+	    plast = pnext;
+	  }
+	  ax25_set_nextp (plast, pp);
+	}
+
+	dw_mutex_unlock (&tq_mutex);
+
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("lm_seize_request: left critical section\n");
+#endif
+
+
+#if DEBUG
+	dw_printf ("lm_seize_request (): about to wake up xmit thread.\n");
+#endif
+#if __WIN32__
+	SetEvent (wake_up_event[chan]);
+#else
+	if (xmit_thread_is_waiting[chan]) {
+	  int err;
+
+	  dw_mutex_lock (&(wake_up_mutex[chan]));
+
+	  err = pthread_cond_signal (&(wake_up_cond[chan]));
+	  if (err != 0) {
+	    text_color_set(DW_COLOR_ERROR);
+	    dw_printf ("lm_seize_request: pthread_cond_signal err=%d", err);
+	    perror ("");
+	    exit (1);
+	  }
+
+	  dw_mutex_unlock (&(wake_up_mutex[chan]));
+	}
+#endif
+
+} /* end lm_seize_request */
+
+
 
 
 /*-------------------------------------------------------------------
@@ -484,7 +819,61 @@ packet_t tq_remove (int chan, int prio)
 	}
 #endif
 	return (result_p);
-}
+
+} /* end tq_remove */
+
+
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        tq_peek
+ *
+ * Purpose:     Take a peek at the next frame in the queue but don't remove it.
+ *
+ * Inputs:	chan	- Channel, 0 is first.
+ *
+ *		prio	- Priority, use TQ_PRIO_0_HI or TQ_PRIO_1_LO.
+ *
+ * Returns:	Pointer to packet object or NULL.
+ *
+ *		Caller should NOT destroy it because it is still in the queue.
+ *
+ *--------------------------------------------------------------------*/
+
+packet_t tq_peek (int chan, int prio)
+{
+
+	packet_t result_p;
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("tq_peek(%d,%d) enter critical section\n", chan, prio);
+#endif
+
+	// I don't think we need critical region here.
+	//dw_mutex_lock (&tq_mutex);
+
+	result_p = queue_head[chan][prio];
+	// Just take a peek at the head.  Don't remove it.
+
+	//dw_mutex_unlock (&tq_mutex);
+
+#if DEBUG
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("tq_remove(%d,%d) leave critical section, returns %p\n", chan, prio, result_p);
+#endif
+
+#if AX25MEMDEBUG
+
+	if (ax25memdebug_get() && result_p != NULL) {
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("tq_remove (chan=%d, prio=%d)  seq=%d\n", chan, prio, ax25memdebug_seq(result_p));
+	}
+#endif
+	return (result_p);
+
+} /* end tq_peek */
+
 
 
 /*-------------------------------------------------------------------

tq.h

@@ -24,10 +24,16 @@ void tq_init (struct audio_s *audio_config_p);
 
 void tq_append (int chan, int prio, packet_t pp);
 
+void lm_data_request (int chan, int prio, packet_t pp);
+
+void lm_seize_request (int chan);
+
 void tq_wait_while_empty (int chan);
 
 packet_t tq_remove (int chan, int prio);
 
+packet_t tq_peek (int chan, int prio);
+
 int tq_count (int chan, int prio);
 
 #endif

waypoint.c

@@ -502,7 +502,7 @@ void waypoint_send_sentence (char *name_in, double dlat, double dlong, char symt
  *					These would not be parsed properly:
  *
  *						$PKWDWPL,150753,V,4237.14,N,07120.83,W,,,190316,,test3,/,*1B
- *						$PKWDWPL,150758,V,4237.14,N,07120.83,W,,,190316,,test4,/**3B
+ *						$PKWDWPL,150758,V,4237.14,N,07120.83,W,,,190316,,test4,/ **3B
  *
  *					We perform the usual substitution and the other end would
  *					need to change them back after extracting from NMEA sentence.

xid.c

@@ -2,7 +2,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2014  John Langner, WB2OSZ
+//    Copyright (C) 2014, 2016  John Langner, WB2OSZ
 //
 //    This program is free software: you can redistribute it and/or modify
 //    it under the terms of the GNU General Public License as published by
@@ -49,28 +49,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <stdio.h>
 
 #include "textcolor.h"
-//#include "xid.h"
-
-
-struct ax25_param_s {
-
-	int full_duplex;
-	
-	// Order is important because negotiation keeps the lower.  
-	enum rej_e {implicit_reject=1, selective_reject=2, selective_reject_reject=3 } rej;
-
-	enum modulo_e {modulo_8 = 8, modulo_128 = 128} modulo;
-
-	int i_field_length_rx;	/* In bytes.  XID has it in bits. */
-
-	int window_size_rx;
-
-	int ack_timer;		/* "T1" in mSec. */
-
-	int retries;		/* "N1" */
-};
+#include "xid.h"
 
 
 
@@ -102,13 +84,20 @@ struct ax25_param_s {
 
 /*-------------------------------------------------------------------
  *
- * Name:        ...
+ * Name:        xid_parse
  *
- * Purpose:    	...
+ * Purpose:    	Decode information part of XID frame into individual values.
  *
- * Inputs:	...
+ * Inputs:	info		- pointer to information part of frame.
  *
- * Outputs:	...
+ *		info_len	- Number of bytes in information part of frame.
+ *				  Could be 0.
+ *
+ *		desc_size	- Size of desc.  100 is good.
+ *
+ * Outputs:	result		- Structure with extracted values.
+ *
+ *		desc		- Text description for troubleshooting.
  *
  * Returns:	1 for mostly successful (with possible error messages), 0 for failure.
  *
@@ -120,37 +109,44 @@ struct ax25_param_s {
  *--------------------------------------------------------------------*/
 
 
-
-
-
-int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
+int xid_parse (unsigned char *info, int info_len, struct xid_param_s *result, char *desc, int desc_size)
 {
 	unsigned char *p;
 	int group_len;
 	char stemp[64];
-	char debug_msg[256];
 
 
-	result->full_duplex = 0;
+	strlcpy (desc, "", desc_size);
 
-	// Default is implicit reject for pre version 2.2 but we wouldn't be here in that case.
-	result->rej = selective_reject;
+// What should we do when some fields are missing?
 
-	result->modulo = modulo_8;
+// The  AX.25 v2.2 protocol spec says, for most of these,
+//	"If this field is not present, the current values are retained."
 
-	result->i_field_length_rx = 256;	// bytes here but converted to bits during encoding.
+// We set the values to our usual G_UNKNOWN to mean undefined and let the caller deal with it.
 
-	// Default is 4 for pre version 2.2 but we wouldn't be here in that case.
-	result->window_size_rx = result->modulo == modulo_128 ? 32 : 7;
 
-	result->ack_timer = 3000;
-	result->retries = 10;
+	result->full_duplex = G_UNKNOWN;
+	result->rej = G_UNKNOWN;
+	result->modulo = G_UNKNOWN;
+	result->i_field_length_rx = G_UNKNOWN;
+	result->window_size_rx = G_UNKNOWN;
+	result->ack_timer = G_UNKNOWN;
+	result->retries = G_UNKNOWN;
+
+
+/* Information field is optional but that seems pretty lame. */
+
+	if (info_len == 0) {
+	  return (1);
+	}
 
 	p = info;
 
 	if (*p != FI_Format_Indicator) {
 	  text_color_set (DW_COLOR_ERROR);
-	  dw_printf ("XID error: First byte of info field should be Format Indicator, %d.\n", FI_Format_Indicator);
+	  dw_printf ("XID error: First byte of info field should be Format Indicator, %02x.\n", FI_Format_Indicator);
+	  dw_printf ("XID info part: %02x %02x %02x %02x %02x ... length=%d\n", info[0], info[1], info[2], info[3], info[4], info_len);
 	  return 0;
 	}
 	p++;
@@ -192,38 +188,46 @@ int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
 
 	      if (pval & PV_Classes_Procedures_Half_Duplex && ! (pval & PV_Classes_Procedures_Full_Duplex)) {
 	        result->full_duplex = 0;
+	        strlcat (desc, "Half-Duplex ", desc_size);
 	      }
 	      else if (pval & PV_Classes_Procedures_Full_Duplex && ! (pval & PV_Classes_Procedures_Half_Duplex)) {
 	        result->full_duplex = 1;
+	        strlcat (desc, "Full-Duplex ", desc_size);
 	      }
 	      else {
 	        text_color_set (DW_COLOR_ERROR);
 	        dw_printf ("XID error: Expected one of Half or Full Duplex be set.\n");	
+	        result->full_duplex = 0;
 	      }
 
 	      break;
 
 	    case PI_HDLC_Optional_Functions:	
 
-	      if (pval & PV_HDLC_Optional_Functions_REJ_cmd_resp && pval & PV_HDLC_Optional_Functions_SREJ_cmd_resp) {
+	      if ((pval & PV_HDLC_Optional_Functions_REJ_cmd_resp) && (pval & PV_HDLC_Optional_Functions_SREJ_cmd_resp)) {
 	        result->rej = selective_reject_reject;		/* Both bits set */
+	        strlcat (desc, "SREJ-REJ ", desc_size);
 	      }
-	      else if (pval & PV_HDLC_Optional_Functions_REJ_cmd_resp && ! (pval & PV_HDLC_Optional_Functions_SREJ_cmd_resp)) {
+	      else if ((pval & PV_HDLC_Optional_Functions_REJ_cmd_resp) && ! (pval & PV_HDLC_Optional_Functions_SREJ_cmd_resp)) {
 	        result->rej = implicit_reject;			/* Only REJ is set */
+	        strlcat (desc, "REJ ", desc_size);
 	      }
 	      else if ( ! (pval & PV_HDLC_Optional_Functions_REJ_cmd_resp) && pval & PV_HDLC_Optional_Functions_SREJ_cmd_resp) {
 	        result->rej = selective_reject;			/* Only SREJ is set */
+	        strlcat (desc, "SREJ ", desc_size);
 	      }
 	      else {
 	        text_color_set (DW_COLOR_ERROR);
 	        dw_printf ("XID error: Expected one or both of REJ, SREJ to be set.\n");	
 	      }
 
-	      if (pval & PV_HDLC_Optional_Functions_Modulo_8 && ! (pval & PV_HDLC_Optional_Functions_Modulo_128)) {
+	      if ((pval & PV_HDLC_Optional_Functions_Modulo_8) && ! (pval & PV_HDLC_Optional_Functions_Modulo_128)) {
 	        result->modulo = modulo_8;
+	        strlcat (desc, "modulo-8 ", desc_size);
 	      }
-	      else if (pval & PV_HDLC_Optional_Functions_Modulo_128 && ! (pval & PV_HDLC_Optional_Functions_Modulo_8)) {
+	      else if ((pval & PV_HDLC_Optional_Functions_Modulo_128) && ! (pval & PV_HDLC_Optional_Functions_Modulo_8)) {
 	        result->modulo = modulo_128;
+	        strlcat (desc, "modulo-128 ", desc_size);
 	      }
 	      else {
 	        text_color_set (DW_COLOR_ERROR);
@@ -256,6 +260,9 @@ int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
 	      
 	      result->i_field_length_rx = pval / 8;
 
+	      snprintf (stemp, sizeof(stemp), "I-Field-Length-Rx=%d ", result->i_field_length_rx);
+	      strlcat (desc, stemp, desc_size);
+
 	      if (pval & 0x7) {
 	        text_color_set (DW_COLOR_ERROR);
 	        dw_printf ("XID error: I Field Length Rx, %d, is not a whole number of bytes.\n", pval);
@@ -267,22 +274,34 @@ int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
 
 	      result->window_size_rx = pval;
 
-	      if (pval < 1 || pval >= result->modulo) {
+	      snprintf (stemp, sizeof(stemp), "Window-Size-Rx=%d ", result->window_size_rx);
+	      strlcat (desc, stemp, desc_size);
+
+	      if (pval < 1 || pval > 127) {
 	        text_color_set (DW_COLOR_ERROR);
-	        dw_printf ("XID error: Window Size Rx, %d, is not in range of 1 thru %d.\n", pval, result->modulo-1);
-	        result->window_size_rx = result->modulo == modulo_128 ? 32 : 7;
+	        dw_printf ("XID error: Window Size Rx, %d, is not in range of 1 thru 127.\n", pval);
+	        result->window_size_rx = 127;
+		// Let the caller deal with modulo 8 consideration.
 	      }
 
-//continue here.
+//continue here with more error checking.
 
 	      break;
 
 	    case PI_Ack_Timer:	
 	      result->ack_timer = pval;
+
+	      snprintf (stemp, sizeof(stemp), "Ack-Timer=%d ", result->ack_timer);
+	      strlcat (desc, stemp, desc_size);
+
 	      break;
 
-	    case PI_Retries:
+	    case PI_Retries:			// Is it retrys or retries?
 	      result->retries = pval;
+
+	      snprintf (stemp, sizeof(stemp), "Retries=%d ", result->retries);
+	      strlcat (desc, stemp, desc_size);
+
 	      break;
 
 	    default:		
@@ -338,9 +357,10 @@ int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
  *
  * Outputs:	info	- Information part of XID frame.
  *			  Does not include the control byte.
- *			  Supply 32 bytes to be safe.
+ *			  Use buffer of 40 bytes just to be safe.
  *
  * Returns:	Number of bytes in the info part.  Should be at most 27.
+ *		Again, provide a larger space just to be safe in case this ever changes.
  *
  * Description:	6.3.2  "Parameter negotiation occurs at any time. It is accomplished by sending
  *		the XID command frame and receiving the XID response frame. Implementations of
@@ -359,35 +379,57 @@ int xid_parse (unsigned char *info, int info_len, struct ax25_param_s *result)
  *		Both TNCs set themselves up based on the values used in the XID response. Negotiation
  *		is used by Classes of Procedures, HDLC Optional Functions, Acknowledge Timer and Retries."
  *
+ * Comment:	I have a problem with "... occurs at any time."  What if we were in the middle
+ *		of transferring a large file with k=32 then along comes XID which says switch to modulo 8?
+ *
  *--------------------------------------------------------------------*/
 
 
-int xid_encode (struct ax25_param_s *param, unsigned char *info)
+int xid_encode (struct xid_param_s *param, unsigned char *info)
 {
 	unsigned char *p;
 	int len;
 	int x;
+	int m = 0;
+
 
 	p = info;
 
 	*p++ = FI_Format_Indicator;
 	*p++ = GI_Group_Identifier;
 	*p++ = 0;
-	*p++ = 0x17;
+
+	m = 4;		// classes of procedures
+	m += 5;		// HDLC optional features
+	if (param->i_field_length_rx != G_UNKNOWN) m += 4;
+	if (param->window_size_rx != G_UNKNOWN) m += 3;
+	if (param->ack_timer != G_UNKNOWN) m += 4;
+	if (param->retries != G_UNKNOWN) m += 3;
+
+	*p++ = m;		// 0x17 if all present.
+
+// "Classes of Procedures" has half / full duplex.
+
+// We always send this.
 
 	*p++ = PI_Classes_of_Procedures;
 	*p++ = 2;
 	
 	x = PV_Classes_Procedures_Balanced_ABM;
 
-	if (param->full_duplex)
+	if (param->full_duplex == 1)
 	  x |= PV_Classes_Procedures_Full_Duplex;
-	else
+	else	// includes G_UNKNOWN
 	  x |= PV_Classes_Procedures_Half_Duplex;
 
 	*p++ = (x >> 8) & 0xff;
 	*p++ = x & 0xff;
 
+// "HDLC Optional Functions" contains REJ/SREJ & modulo 8/128.
+
+// We always send this.
+// Watch out for unknown values and do something reasonable.
+
 	*p++ = PI_HDLC_Optional_Functions;
 	*p++ = 3;
 
@@ -396,7 +438,7 @@ int xid_encode (struct ax25_param_s *param, unsigned char *info)
 		PV_HDLC_Optional_Functions_16_bit_FCS | 
 		PV_HDLC_Optional_Functions_Synchronous_Tx;
 
-	if (param->rej == implicit_reject || param->rej == selective_reject_reject)
+	if (param->rej == implicit_reject || param->rej == selective_reject_reject || param->rej == G_UNKNOWN)
 	  x |= PV_HDLC_Optional_Functions_REJ_cmd_resp;
 
 	if (param->rej == selective_reject || param->rej == selective_reject_reject)	
@@ -404,13 +446,18 @@ int xid_encode (struct ax25_param_s *param, unsigned char *info)
 
 	if (param->modulo == modulo_128)
 	  x |= PV_HDLC_Optional_Functions_Modulo_128;
-	else
+	else	// includes G_UNKNOWN
 	  x |= PV_HDLC_Optional_Functions_Modulo_8;
 
 	*p++ = (x >> 16) & 0xff;
 	*p++ = (x >> 8) & 0xff;
 	*p++ = x & 0xff;
 
+// The rest are skipped if undefined values.
+
+// "I Field Length Rx" - max I field length acceptable to me.
+// This is in bits.  8191 would be max number of bytes to fit in field.
+
 	if (param->i_field_length_rx != G_UNKNOWN) {
 	  *p++ = PI_I_Field_Length_Rx;
 	  *p++ = 2;
@@ -419,12 +466,16 @@ int xid_encode (struct ax25_param_s *param, unsigned char *info)
 	  *p++ = x & 0xff;
 	}
 
+// "Window Size Rx"
+
 	if (param->window_size_rx != G_UNKNOWN) {
 	  *p++ = PI_Window_Size_Rx;
 	  *p++ = 1;
 	  *p++ = param->window_size_rx;
 	}
 
+// "Ack Timer" milliseconds.  We could handle up to 65535 here.
+
 	if (param->ack_timer != G_UNKNOWN) {
 	  *p++ = PI_Ack_Timer;
 	  *p++ = 2;
@@ -432,6 +483,8 @@ int xid_encode (struct ax25_param_s *param, unsigned char *info)
 	  *p++ = param->ack_timer & 0xff;
 	}
 
+// "Retries."
+
 	if (param->retries != G_UNKNOWN) {
 	  *p++ = PI_Retries;
 	  *p++ = 1;
@@ -439,7 +492,7 @@ int xid_encode (struct ax25_param_s *param, unsigned char *info)
 	}
 
 	len = p - info;
-	assert (len <= 27);
+
 	return (len);
 
 } /* end xid_encode */
@@ -508,14 +561,19 @@ static unsigned char example[27] = {
 
 int main (int argc, char *argv[]) {
 
-	struct ax25_param_s param;
-	struct ax25_param_s param2;
+	struct xid_param_s param;
+	struct xid_param_s param2;
 	int n;
-	unsigned char info[40];
+	unsigned char info[40];	// Currently max of 27 but things can change.
+	char desc[100];		// 80 is not adequate.
+
 
 /* parse example. */
 
-	n = xid_parse (example, sizeof(example), &param);
+	n = xid_parse (example, sizeof(example), &param, desc, sizeof(desc));
+
+	text_color_set (DW_COLOR_DEBUG);
+	dw_printf ("%s\n", desc);
 
 	text_color_set (DW_COLOR_ERROR);
 
@@ -548,40 +606,96 @@ int main (int argc, char *argv[]) {
 	param.modulo = modulo_8;
 	param.i_field_length_rx = 2048;
 	param.window_size_rx = 3;
-	param.ack_timer = 3000;
-	param.retries = 10;
+	param.ack_timer = 1234;
+	param.retries = 12;
 
 	n = xid_encode (&param, info);
-	n = xid_parse (info, n, &param2);
+	n = xid_parse (info, n, &param2, desc, sizeof(desc));
+
+	text_color_set (DW_COLOR_DEBUG);
+	dw_printf ("%s\n", desc);
+
+	text_color_set (DW_COLOR_ERROR);
 
 	assert (param2.full_duplex == 1);
 	assert (param2.rej == implicit_reject);
 	assert (param2.modulo == modulo_8);
 	assert (param2.i_field_length_rx == 2048);
 	assert (param2.window_size_rx == 3);
-	assert (param2.ack_timer == 3000);
-	assert (param2.retries == 10);
+	assert (param2.ack_timer == 1234);
+	assert (param2.retries == 12);
 
-/* Finally the third possbility for rej. */
+/* The third possbility for rej.   We don't use this. */
 
 	param.full_duplex = 0;
 	param.rej = selective_reject;
 	param.modulo = modulo_8;
-	param.i_field_length_rx = 256;
+	param.i_field_length_rx = 61;
 	param.window_size_rx = 4;
-	param.ack_timer = 3000;
-	param.retries = 10;
+	param.ack_timer = 5555;
+	param.retries = 9;
 
 	n = xid_encode (&param, info);
-	n = xid_parse (info, n, &param2);
+	n = xid_parse (info, n, &param2, desc, sizeof(desc));
+
+	text_color_set (DW_COLOR_DEBUG);
+	dw_printf ("%s\n", desc);
+
+	text_color_set (DW_COLOR_ERROR);
 
 	assert (param2.full_duplex == 0);
 	assert (param2.rej == selective_reject);
 	assert (param2.modulo == modulo_8);
-	assert (param2.i_field_length_rx == 256);
+	assert (param2.i_field_length_rx == 61);
 	assert (param2.window_size_rx == 4);
-	assert (param2.ack_timer == 3000);
-	assert (param2.retries == 10);
+	assert (param2.ack_timer == 5555);
+	assert (param2.retries == 9);
+
+
+/* Specify some and not others. */
+
+	param.full_duplex = 0;
+	param.rej = selective_reject;
+	param.modulo = modulo_8;
+	param.i_field_length_rx = G_UNKNOWN;
+	param.window_size_rx = G_UNKNOWN;
+	param.ack_timer = 999;
+	param.retries = G_UNKNOWN;
+
+	n = xid_encode (&param, info);
+	n = xid_parse (info, n, &param2, desc, sizeof(desc));
+
+	text_color_set (DW_COLOR_DEBUG);
+	dw_printf ("%s\n", desc);
+
+	text_color_set (DW_COLOR_ERROR);
+
+	assert (param2.full_duplex == 0);
+	assert (param2.rej == selective_reject);
+	assert (param2.modulo == modulo_8);
+	assert (param2.i_field_length_rx == G_UNKNOWN);
+	assert (param2.window_size_rx == G_UNKNOWN);
+	assert (param2.ack_timer == 999);
+	assert (param2.retries == G_UNKNOWN);
+
+/* Default values for empty info field. */
+
+	n = 0;
+	n = xid_parse (info, n, &param2, desc, sizeof(desc));
+
+	text_color_set (DW_COLOR_DEBUG);
+	dw_printf ("%s\n", desc);
+
+	text_color_set (DW_COLOR_ERROR);
+
+	assert (param2.full_duplex == G_UNKNOWN);
+	assert (param2.rej == G_UNKNOWN);
+	assert (param2.modulo == G_UNKNOWN);
+	assert (param2.i_field_length_rx == G_UNKNOWN);
+	assert (param2.window_size_rx == G_UNKNOWN);
+	assert (param2.ack_timer == G_UNKNOWN);
+	assert (param2.retries == G_UNKNOWN);
+
 
 	text_color_set (DW_COLOR_REC);
 	dw_printf ("XID test:  Success.\n");	

xid.h

@@ -0,0 +1,31 @@
+
+
+/* xid.h */
+
+#include "ax25_pad.h"		// for enum ax25_modulo_e
+
+
+struct xid_param_s {
+
+	int full_duplex;
+	
+	// Order is important because negotiation keeps the lower value.
+	// We will support only 1 & 2.
+
+	enum rej_e {implicit_reject=1, selective_reject=2, selective_reject_reject=3 } rej;
+
+	enum ax25_modulo_e modulo;
+
+	int i_field_length_rx;	/* In bytes.  XID has it in bits. */
+
+	int window_size_rx;
+
+	int ack_timer;		/* "T1" in mSec. */
+
+	int retries;		/* "N1" */
+};
+
+
+int xid_parse (unsigned char *info, int info_len, struct xid_param_s *result, char *desc, int desc_size);
+
+int xid_encode (struct xid_param_s *param, unsigned char *info);

xmit.c

@@ -2,7 +2,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2011, 2013, 2014, 2015  John Langner, WB2OSZ
+//    Copyright (C) 2011, 2013, 2014, 2015, 2016  John Langner, WB2OSZ
 //
 //    This program is free software: you can redistribute it and/or modify
 //    it under the terms of the GNU General Public License as published by
@@ -72,6 +72,7 @@
 #include "ptt.h"
 #include "dtime_now.h"
 #include "morse.h"
+#include "xid.h"
 
 
 
@@ -107,6 +108,9 @@ static int xmit_bits_per_sec[MAX_CHANS];	/* Data transmission rate. */
 static int g_debug_xmit_packet;		/* print packet in hexadecimal form for debugging. */
 
 
+// TODO: When this was first written, bits/sec was same as baud.
+// Need to revisit this for PSK modes where they are not the same.
+
 
 #define BITS_TO_MS(b,ch) (((b)*1000)/xmit_bits_per_sec[(ch)])
 
@@ -130,8 +134,9 @@ static dw_mutex_t audio_out_dev_mutex[MAX_ADEVS];
 
 
 
-static int wait_for_clear_channel (int channel, int nowait, int slotttime, int persist);
-static void xmit_ax25_frames (int c, int p, packet_t pp);
+static int wait_for_clear_channel (int channel, int slotttime, int persist);
+static void xmit_ax25_frames (int c, int p, packet_t pp, int max_bundle);
+static int send_one_frame (int c, int p, packet_t pp);
 static void xmit_speech (int c, packet_t pp);
 static void xmit_morse (int c, packet_t pp, int wpm);
 
@@ -346,6 +351,62 @@ void xmit_set_txtail (int channel, int value)
 	}
 }
 
+
+/*-------------------------------------------------------------------
+ *
+ * Name:        frame_flavor
+ *
+ * Purpose:     Separate frames into different flavors so we can decide
+ *		which can be bundled into a single transmission and which should
+ *		be sent separately.
+ *
+ * Inputs:	pp	- Packet object.
+ *
+ * Returns:	Flavor, one of:
+ *
+ *		FLAVOR_SPEECH		- Destination address is SPEECH.
+ *		FLAVOR_MORSE		- Destination address is MORSE.
+ *		FLAVOR_APRS_NEW		- APRS original, i.e. not digipeating.
+ *		FLAVOR_APRS_DIGI	- APRS digipeating.
+ *		FLAVOR_OTHER		- Anything left over, i.e. connected mode.
+ *
+ *--------------------------------------------------------------------*/
+
+typedef enum flavor_e { FLAVOR_APRS_NEW, FLAVOR_APRS_DIGI, FLAVOR_SPEECH, FLAVOR_MORSE, FLAVOR_OTHER } flavor_t;
+
+static flavor_t frame_flavor (packet_t pp)
+{
+
+	if (ax25_is_aprs (pp)) { 	// UI frame, PID 0xF0.
+					// It's unfortunate APRS did not use its own special PID.
+
+	  char dest[AX25_MAX_ADDR_LEN];
+
+	  ax25_get_addr_no_ssid(pp, AX25_DESTINATION, dest);
+
+	  if (strcmp(dest, "SPEECH") == 0) {
+	   return (FLAVOR_SPEECH);
+	  }
+
+	  if (strcmp(dest, "MORSE") == 0) {
+	   return (FLAVOR_MORSE);
+	  }
+
+	  /* Is there at least one digipeater AND has first one been used? */
+	  /* I could be the first in the list or later.  Doesn't matter. */
+
+	  if (ax25_get_num_repeaters(pp) >= 1 && ax25_get_h(pp,AX25_REPEATER_1)) {
+	    return (FLAVOR_APRS_DIGI);
+	  }
+
+	  return (FLAVOR_APRS_NEW);
+	}
+
+	return (FLAVOR_OTHER);
+
+} /* end frame_flavor */
+
+  
 /*-------------------------------------------------------------------
  *
  * Name:        xmit_thread
@@ -367,6 +428,9 @@ void xmit_set_txtail (int channel, int value)
  *			rather than waiting random times to avoid collisions.
  *			The KPC-3 configuration option for this is "UIDWAIT OFF".  (?)
  *
+ *			AX.25 connected mode also has a couple cases
+ *			where "expedited" frames are sent.
+ *
  *		Low Priority - 
  *
  *			Other packets are sent after a random wait time
@@ -382,6 +446,11 @@ void xmit_set_txtail (int channel, int value)
  * 		each channel has its own thread.
  *		Add speech capability.
  *
+ * Version 1.4:	Rearranged logic for bundling multiple frames into a single transmission.
+ *
+ *		The rule is that Speech, Morse Code, and APRS digipeated frames
+ *		are all sent separately.  The rest can be bundled.
+ *
  *--------------------------------------------------------------------*/
 
 #if __WIN32__
@@ -390,119 +459,126 @@ static unsigned __stdcall xmit_thread (void *arg)
 static void * xmit_thread (void *arg)
 #endif
 {
-	int c = (int)(long)arg; // channel number.
+	int chan = (int)(long)arg; // channel number.
 	packet_t pp;
-	int p;
+	int prio;
 	int ok;
 
-/*
- * These are for timing of a transmission.
- * All are in usual unix time (seconds since 1/1/1970) but higher resolution
- */
-
 
 	while (1) {
 
-	  tq_wait_while_empty (c);
+	  tq_wait_while_empty (chan);
 #if DEBUG
 	  text_color_set(DW_COLOR_DEBUG);
 	  dw_printf ("xmit_thread, channel %d: woke up\n", c);
 #endif
 
-	  for (p=0; p<TQ_NUM_PRIO; p++) {
-
-	      pp = tq_remove (c, p);
-#if DEBUG
-	      text_color_set(DW_COLOR_DEBUG);
-	      dw_printf ("xmit_thread: tq_remove(chan=%d, prio=%d) returned %p\n", c, p, pp);
-#endif
-	      if (pp != NULL) {
+	  // Does this extra loop offer any benefit?
+	  while (tq_peek(chan, TQ_PRIO_0_HI) != NULL || tq_peek(chan, TQ_PRIO_1_LO) != NULL) {
 
 /* 
  * Wait for the channel to be clear.
- * For the high priority queue, begin transmitting immediately.
- * For the low priority queue, wait a random amount of time, in hopes
- * of minimizing collisions.
+ * If there is something in the high priority queue, begin transmitting immediately.
+ * Otherwise, wait a random amount of time, in hopes of minimizing collisions.
  */
-	        ok = wait_for_clear_channel (c, (p==TQ_PRIO_0_HI), xmit_slottime[c], xmit_persist[c]);
+	    ok = wait_for_clear_channel (chan, xmit_slottime[chan], xmit_persist[chan]);
 
-	        if (ok) {
+	    prio = TQ_PRIO_1_LO;
+	    pp = tq_remove (chan, TQ_PRIO_0_HI);
+	    if (pp != NULL) {
+	      prio = TQ_PRIO_0_HI;
+	    }
+	    else {
+	      pp = tq_remove (chan, TQ_PRIO_1_LO);
+	    }
+
+#if DEBUG
+	    text_color_set(DW_COLOR_DEBUG);
+	    dw_printf ("xmit_thread: tq_remove(chan=%d, prio=%d) returned %p\n", chan, prio, pp);
+#endif
+	    // Shouldn't have NULL here but be careful.
+
+	    if (pp != NULL) {
+
+
+	      if (ok) {
 /*
  * Channel is clear and we have lock on output device. 
  *
  * If destination is "SPEECH" send info part to speech synthesizer.
  * If destination is "MORSE" send as morse code.
  */
-	          char dest[AX25_MAX_ADDR_LEN];
-		  int ssid = 0;
 
+	        int ssid, wpm;
 
-	          if (ax25_is_aprs (pp)) { 
+	        switch (frame_flavor(pp)) {
 
-		    ax25_get_addr_no_ssid(pp, AX25_DESTINATION, dest);
+	          case FLAVOR_SPEECH:
+	            xmit_speech (chan, pp);
+	            break;
+
+	          case FLAVOR_MORSE:
 		    ssid = ax25_get_ssid(pp, AX25_DESTINATION);
-	 	  }
-	 	  else {
-		    strlcpy (dest, "", sizeof(dest));
-	          }
-
-		  if (strcmp(dest, "SPEECH") == 0) {
-	            xmit_speech (c, pp);
-	          }
-		  else if (strcmp(dest, "MORSE") == 0) {
-
-		    int wpm = ssid * 2;
-		    if (wpm == 0) wpm = MORSE_DEFAULT_WPM;
+		    wpm = (ssid > 0) ? (ssid * 2) : MORSE_DEFAULT_WPM;
 
 		    // This is a bit of a hack so we don't respond too quickly for APRStt.
 		    // It will be sent in high priority queue while a beacon wouldn't.  
 		    // Add a little delay so user has time release PTT after sending #.
 		    // This and default txdelay would give us a second.
 
-		    if (p == TQ_PRIO_0_HI) {
+		    if (prio == TQ_PRIO_0_HI) {
 	              //text_color_set(DW_COLOR_DEBUG);
 		      //dw_printf ("APRStt morse xmit delay hack...\n");
 		      SLEEP_MS (700);
 		    }
+	            xmit_morse (chan, pp, wpm);
+	            break;
 
-	            xmit_morse (c, pp, wpm);
-	          }
-	          else {
-	            xmit_ax25_frames (c, p, pp);
-		  }
+	          case FLAVOR_APRS_DIGI:
+	            xmit_ax25_frames (chan, prio, pp, 1);	/* 1 means don't bundle */
+	            break;
 
-	          dw_mutex_unlock (&(audio_out_dev_mutex[ACHAN2ADEV(c)]));
+	          case FLAVOR_APRS_NEW:
+	          case FLAVOR_OTHER:
+	          default:
+	            xmit_ax25_frames (chan, prio, pp, 256);
+	            break;
 	        }
-	        else {
+
+	        // Corresponding lock is in wait_for_clear_channel.
+
+	        dw_mutex_unlock (&(audio_out_dev_mutex[ACHAN2ADEV(chan)]));
+	      }
+	      else {
 /*
  * Timeout waiting for clear channel.
  * Discard the packet.
  * Display with ERROR color rather than XMIT color.
  */
-		  char stemp[1024];	/* max size needed? */
-		  int info_len;
-		  unsigned char *pinfo;
+		char stemp[1024];	/* max size needed? */
+		int info_len;
+		unsigned char *pinfo;
 
 
-	          text_color_set(DW_COLOR_ERROR);
-		  dw_printf ("Waited too long for clear channel.  Discarding packet below.\n");
+	        text_color_set(DW_COLOR_ERROR);
+		dw_printf ("Waited too long for clear channel.  Discarding packet below.\n");
 
-	          ax25_format_addrs (pp, stemp);
+	        ax25_format_addrs (pp, stemp);
 
-	          info_len = ax25_get_info (pp, &pinfo);
+	        info_len = ax25_get_info (pp, &pinfo);
 
-	          text_color_set(DW_COLOR_INFO);
-	          dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
+	        text_color_set(DW_COLOR_INFO);
+	        dw_printf ("[%d%c] ", chan, (prio==TQ_PRIO_0_HI) ? 'H' : 'L');
 
-	          dw_printf ("%s", stemp);			/* stations followed by : */
-	          ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
-	          dw_printf ("\n");
-		  ax25_delete (pp);
+	        dw_printf ("%s", stemp);			/* stations followed by : */
+	        ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
+	        dw_printf ("\n");
+		ax25_delete (pp);
 
-		} /* wait for clear channel. */
-	    } /* for high priority then low priority */
-	  }
-	}
+	      } /* wait for clear channel error. */
+	    } /* Have pp */
+	  } /* while queue not empty */
+	} /* while 1 */
 
 	return 0;	/* unreachable but quiet the warning. */
 
@@ -517,28 +593,31 @@ static void * xmit_thread (void *arg)
  * Purpose:     After we have a clear channel, and possibly waited a random time,
  *		we transmit one or more frames.
  *
- * Inputs:	c	- Channel number.
+ * Inputs:	chan	- Channel number.
  *	
- *		p	- Priority of the queue.
+ *		prio	- Priority of the first frame.
+ *			  Subsequent frames could be different.
  *
  *		pp	- Packet object pointer.
  *			  It will be deleted so caller should not try
  *			  to reference it after this.	
  *
+ *		max_bundle - Max number of frames to bundle into one transmission.
+ *
  * Description:	Turn on transmitter.
  *		Send flags for TXDELAY time.
  *		Send the first packet, given by pp.
- *		Possibly send more packets from the same queue.
+ *		Possibly send more packets from either queue.
  *		Send flags for TXTAIL time.
  *		Turn off transmitter.
  *
  *
- * How many frames in one transmission?
+ * How many frames in one transmission?  (for APRS)
  *
  *		Should we send multiple frames in one transmission if we 
  *		have more than one sitting in the queue?  At first I was thinking
  *		this would help reduce channel congestion.  I don't recall seeing
- *		anything in the specifications allowing or disallowing multiple
+ *		anything in the APRS specifications allowing or disallowing multiple
  *		frames in one transmission.  I can think of some scenarios 
  *		where it might help.  I can think of some where it would 
  *		definitely be counter productive.  
@@ -558,21 +637,27 @@ static void * xmit_thread (void *arg)
  * Version 0.9:	Earlier versions always sent one frame per transmission.
  *		This was fine for APRS but more and more people are now
  *		using this as a KISS TNC for connected protocols.
- *		Rather than having a MAXFRAME configuration file item,
+ *		Rather than having a configuration file item,
  *		we try setting the maximum number automatically.
  *		1 for digipeated frames, 7 for others.
  *
+ * Version 1.4: Lift the limit.  We could theoretically have a window size up to 127.
+ *		If another section pumps out that many quickly we shouldn't
+ *		break it up here.  Empty out both queues with some exceptions.
+ *
+ *		Digipeated APRS, Speech, and Morse code should have
+ *		their own separate transmissions.
+ *		Everything else can be bundled together.
+ *		Different priorities can share a single transmission.
+ *		Once we have control of the channel, we might as well keep going.
+ *		[High] Priority frames will always go to head of the line,
+ *
  *--------------------------------------------------------------------*/
 
 
-static void xmit_ax25_frames (int c, int p, packet_t pp)
+static void xmit_ax25_frames (int chan, int prio, packet_t pp, int max_bundle)
 {
 
-  	unsigned char fbuf[AX25_MAX_PACKET_LEN+2];
-    	int flen;
-	char stemp[1024];	/* max size needed? */
-	int info_len;
-	unsigned char *pinfo;
 	int pre_flags, post_flags;
 	int num_bits;		/* Total number of bits in transmission */
 				/* including all flags and bit stuffing. */
@@ -580,8 +665,7 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 	int already;
 	int wait_more;
 
-	int maxframe;		/* Maximum number of frames for one transmission. */
-	int numframe;		/* Number of frames sent during this transmission. */
+	int numframe = 0;	/* Number of frames sent during this transmission. */
 
 /*
  * These are for timing of a transmission.
@@ -593,49 +677,6 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 
 	int nb;
 
-	maxframe = (p == TQ_PRIO_0_HI) ? 1 : 7;
-
-
-/*
- * Print trasmitted packet.  Prefix by channel and priority.
- * Do this before we get into the time critical part.
- */
-	ax25_format_addrs (pp, stemp);
-	info_len = ax25_get_info (pp, &pinfo);
-	text_color_set(DW_COLOR_XMIT);
-	dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
-	dw_printf ("%s", stemp);			/* stations followed by : */
-
-/* Demystify non-APRS.  Use same format for received frames in direwolf.c. */
-
-	if ( ! ax25_is_aprs(pp)) {
-	  ax25_frame_type_t ftype;
-	  cmdres_t cr;
-	  char desc[32];
-	  int pf;
-	  int nr;
-	  int ns;
-
-	  ftype = ax25_frame_type (pp, &cr, desc, &pf, &nr, &ns);
-	  (void)ftype;
-
-	  dw_printf ("(%s)", desc);
-	}
-
-	ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
-	dw_printf ("\n");
-	(void)ax25_check_addresses (pp);
-
-/* Optional hex dump of packet. */
-
-	if (g_debug_xmit_packet) {
-
-	  text_color_set(DW_COLOR_DEBUG);
-	  dw_printf ("------\n");
-	  ax25_hex_dump (pp);
-    	  dw_printf ("------\n");
-	}
-
 /* 
  * Turn on transmitter.
  * Start sending leading flag bytes.
@@ -647,26 +688,26 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("xmit_thread: Turn on PTT now for channel %d. speed = %d\n", c, xmit_bits_per_sec[c]);
+	dw_printf ("xmit_thread: Turn on PTT now for channel %d. speed = %d\n", chan, xmit_bits_per_sec[chan]);
 #endif
-	ptt_set (OCTYPE_PTT, c, 1);
+	ptt_set (OCTYPE_PTT, chan, 1);
 
-	pre_flags = MS_TO_BITS(xmit_txdelay[c] * 10, c) / 8;
-	num_bits =  hdlc_send_flags (c, pre_flags, 0);
+	pre_flags = MS_TO_BITS(xmit_txdelay[chan] * 10, chan) / 8;
+	num_bits =  hdlc_send_flags (chan, pre_flags, 0);
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("xmit_thread: txdelay=%d [*10], pre_flags=%d, num_bits=%d\n", xmit_txdelay[c], pre_flags, num_bits);
+	dw_printf ("xmit_thread: txdelay=%d [*10], pre_flags=%d, num_bits=%d\n", xmit_txdelay[chan], pre_flags, num_bits);
 #endif
 
 
 /*
  * Transmit the frame.
  */
-	flen = ax25_pack (pp, fbuf);
-	assert (flen >= 1 && flen <= sizeof(fbuf));
-	nb = hdlc_send_frame (c, fbuf, flen);
+
+	nb = send_one_frame (chan, prio, pp);
+
 	num_bits += nb;
-	numframe = 1;
+	if (nb > 0) numframe++;
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
 	dw_printf ("xmit_thread: flen=%d, nb=%d, num_bits=%d, numframe=%d\n", flen, nb, num_bits, numframe);
@@ -674,68 +715,84 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 	ax25_delete (pp);
 
 /*
- * Additional packets if available and not exceeding max.
+ * See if we can bundle additional frames into this transmission.
  */
 
-	while (numframe < maxframe && tq_count (c,p) > 0) {
-
-	  pp = tq_remove (c, p);
-#if DEBUG
-	 text_color_set(DW_COLOR_DEBUG);
-	 dw_printf ("xmit_thread: tq_remove(chan=%d, prio=%d) returned %p\n", c, p, pp);
-#endif
-	 ax25_format_addrs (pp, stemp);
-	 info_len = ax25_get_info (pp, &pinfo);
-	 text_color_set(DW_COLOR_XMIT);
-	 dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
-	 dw_printf ("%s", stemp);			/* stations followed by : */
-	 ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
-	 dw_printf ("\n");
-	 (void)ax25_check_addresses (pp);
-
-	 if (g_debug_xmit_packet) {
-	    text_color_set(DW_COLOR_DEBUG);
-	    dw_printf ("------\n");
-	    ax25_hex_dump (pp);
-    	    dw_printf ("------\n");
-	  }
+	int done = 0;
+	while (numframe < max_bundle && ! done) {
 
 /*
- * Transmit the frame.
+ * Peek at what is available.
+ * Don't remove from queue yet because it might not be eligible.
  */
-	  flen = ax25_pack (pp, fbuf);
-	  assert (flen >= 1 && flen <= sizeof(fbuf));
-	  nb = hdlc_send_frame (c, fbuf, flen);
-	  num_bits += nb;
-	  numframe++;
+	  prio = TQ_PRIO_1_LO;
+	  pp = tq_peek (chan, TQ_PRIO_0_HI);
+	  if (pp != NULL) {
+	    prio = TQ_PRIO_0_HI;
+	  }
+	  else {
+	    pp = tq_peek (chan, TQ_PRIO_1_LO);
+	  }
+
+	  if (pp != NULL) {
+
+	    switch (frame_flavor(pp)) {
+
+	      case FLAVOR_SPEECH:
+	      case FLAVOR_MORSE:
+	      case FLAVOR_APRS_DIGI:
+	      default:
+		done = 1;		// not eligible for bundling.
+	        break;
+
+	      case FLAVOR_APRS_NEW:
+	      case FLAVOR_OTHER:
+
+	        pp = tq_remove (chan, prio);
 #if DEBUG
-	  text_color_set(DW_COLOR_DEBUG);
-	  dw_printf ("xmit_thread: flen=%d, nb=%d, num_bits=%d, numframe=%d\n", flen, nb, num_bits, numframe);
+	        text_color_set(DW_COLOR_DEBUG);
+	        dw_printf ("xmit_thread: tq_remove(chan=%d, prio=%d) returned %p\n", chan, prio, pp);
 #endif
-	  ax25_delete (pp);
+
+	        nb = send_one_frame (chan, prio, pp);
+
+	        num_bits += nb;
+	        if (nb > 0) numframe++;
+#if DEBUG
+	        text_color_set(DW_COLOR_DEBUG);
+	        dw_printf ("xmit_thread: flen=%d, nb=%d, num_bits=%d, numframe=%d\n", flen, nb, num_bits, numframe);
+#endif
+	        ax25_delete (pp);
+
+	        break;
+	    }
+	  }
+	  else {
+	    done = 1;
+	  }
 	}
 
 /* 
  * Need TXTAIL because we don't know exactly when the sound is done.
  */
 
-	post_flags = MS_TO_BITS(xmit_txtail[c] * 10, c) / 8;
-	nb = hdlc_send_flags (c, post_flags, 1);
+	post_flags = MS_TO_BITS(xmit_txtail[chan] * 10, chan) / 8;
+	nb = hdlc_send_flags (chan, post_flags, 1);
 	num_bits += nb;
 #if DEBUG
 	text_color_set(DW_COLOR_DEBUG);
-	dw_printf ("xmit_thread: txtail=%d [*10], post_flags=%d, nb=%d, num_bits=%d\n", xmit_txtail[c], post_flags, nb, num_bits);
+	dw_printf ("xmit_thread: txtail=%d [*10], post_flags=%d, nb=%d, num_bits=%d\n", xmit_txtail[chan], post_flags, nb, num_bits);
 #endif
 
 
 /* 
  * While demodulating is CPU intensive, generating the tones is not.
- * Example: on the RPi, with 50% of the CPU taken with two receive
+ * Example: on the RPi model 1, with 50% of the CPU taken with two receive
  * channels, a transmission of more than a second is generated in
  * about 40 mS of elapsed real time.
  */
 
-	audio_wait(ACHAN2ADEV(c));		
+	audio_wait(ACHAN2ADEV(chan));		
 
 /* 
  * Ideally we should be here just about the time when the audio is ending.
@@ -744,7 +801,7 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
  * Calculate how long the frame(s) should take in milliseconds.
  */
 
-	duration = BITS_TO_MS(num_bits, c);
+	duration = BITS_TO_MS(num_bits, chan);
 
 /*
  * See how long it has been since PTT was turned on.
@@ -786,12 +843,123 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 	dw_printf ("xmit_thread: Turn off PTT now. Actual time on was %d mS, vs. %d desired\n", (int) ((time_now - time_ptt) * 1000.), duration);
 #endif
 		
-	ptt_set (OCTYPE_PTT, c, 0);
+	ptt_set (OCTYPE_PTT, chan, 0);
 
 } /* end xmit_ax25_frames */
 
 
 
+/*-------------------------------------------------------------------
+ *
+ * Name:        send_one_frame
+ *
+ * Purpose:     Send one AX.25 frame.
+ *
+ * Inputs:	c	- Channel number.
+ *
+ *		p	- Priority.
+ *
+ *		pp	- Packet object pointer.  Caller will delete it.
+ *
+ * Returns:	Number of bits transmitted.
+ *
+ * Description:	Caller is responsible for activiating PTT, TXDELAY,
+ *		deciding how many frames can be in one transmission,
+ *		deactivating PTT.
+ *
+ *--------------------------------------------------------------------*/
+
+
+static int send_one_frame (int c, int p, packet_t pp)
+{
+	unsigned char fbuf[AX25_MAX_PACKET_LEN+2];
+	int flen;
+	char stemp[1024];	/* max size needed? */
+	int info_len;
+	unsigned char *pinfo;
+	int nb;
+
+
+	if (ax25_is_null_frame(pp)) {
+	  return(0);
+	}
+
+	ax25_format_addrs (pp, stemp);
+	info_len = ax25_get_info (pp, &pinfo);
+	text_color_set(DW_COLOR_XMIT);
+	dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
+	dw_printf ("%s", stemp);			/* stations followed by : */
+
+/* Demystify non-APRS.  Use same format for received frames in direwolf.c. */
+
+	if ( ! ax25_is_aprs(pp)) {
+	  ax25_frame_type_t ftype;
+	  cmdres_t cr;
+	  char desc[80];
+	  int pf;
+	  int nr;
+	  int ns;
+
+	  ftype = ax25_frame_type (pp, &cr, desc, &pf, &nr, &ns);
+
+	  dw_printf ("(%s)", desc);
+
+	  if (ftype == frame_type_U_XID) {
+	    struct xid_param_s param;
+	    char info2text[100];
+
+	    xid_parse (pinfo, info_len, &param, info2text, sizeof(info2text));
+	    dw_printf (" %s\n", info2text);
+	  }
+	  else {
+	    ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
+	    dw_printf ("\n");
+	  }
+	}
+	else {
+	  ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
+	  dw_printf ("\n");
+	}
+
+	(void)ax25_check_addresses (pp);
+
+/* Optional hex dump of packet. */
+
+	if (g_debug_xmit_packet) {
+
+	  text_color_set(DW_COLOR_DEBUG);
+	  dw_printf ("------\n");
+	  ax25_hex_dump (pp);
+	  dw_printf ("------\n");
+	}
+
+
+/*
+ * Transmit the frame.
+ */
+	flen = ax25_pack (pp, fbuf);
+	assert (flen >= 1 && flen <= sizeof(fbuf));
+
+	int send_invalid_fcs2 = 0;
+
+	if (save_audio_config_p->xmit_error_rate != 0) {
+	  float r = (float)(rand()) / (float)RAND_MAX;		// Random, 0.0 to 1.0
+
+	  if (save_audio_config_p->xmit_error_rate / 100.0 > r) {
+	    send_invalid_fcs2 = 1;
+	    text_color_set(DW_COLOR_INFO);
+	    dw_printf ("Intentionally sending invalid CRC for frame above.  Xmit Error rate = %d per cent.\n", save_audio_config_p->xmit_error_rate);
+	  }
+	}
+
+	nb = hdlc_send_frame (c, fbuf, flen, send_invalid_fcs2);
+	return (nb);
+
+} /* end send_one_frame */
+
+
+
+
 /*-------------------------------------------------------------------
  *
  * Name:        xmit_speech
@@ -814,8 +982,6 @@ static void xmit_ax25_frames (int c, int p, packet_t pp)
 
 static void xmit_speech (int c, packet_t pp)
 {
-
-
 	int info_len;
 	unsigned char *pinfo;
 
@@ -932,8 +1098,6 @@ int xmit_speak_it (char *script, int c, char *orig_msg)
 
 static void xmit_morse (int c, packet_t pp, int wpm)
 {
-
-
 	int info_len;
 	unsigned char *pinfo;
 
@@ -960,15 +1124,7 @@ static void xmit_morse (int c, packet_t pp, int wpm)
  * Purpose:     Wait for the radio channel to be clear and any
  *		additional time for collision avoidance.
  *
- *
- *
- * Inputs:	channel	-	Radio channel number.
- *
- *		nowait	- 	Should be true for the high priority queue
- *				(packets being digipeated).  This will 
- *				allow transmission immediately when the 
- *				channel is clear rather than waiting a 
- *				random amount of time.
+ * Inputs:	chan	-	Radio channel number.
  *
  *		slottime - 	Amount of time to wait for each iteration
  *				of the waiting algorithm.  10 mSec units.
@@ -977,14 +1133,12 @@ static void xmit_morse (int c, packet_t pp, int wpm)
  *
  * Returns:	1 for OK.  0 for timeout.
  *
- * Description:	
- *
- *		New in version 1.2: also obtain a lock on audio out device.
+ * Description:	New in version 1.2: also obtain a lock on audio out device.
  *
  * Transmit delay algorithm:
  *
  *		Wait for channel to be clear.
- *		Return if nowait is true.
+ *		If anything in high priority queue, bail out of the following.
  *
  *		Wait slottime * 10 milliseconds.
  *		Generate an 8 bit random number in range of 0 - 255.
@@ -1015,17 +1169,13 @@ static void xmit_morse (int c, packet_t pp, int wpm)
 #define WAIT_TIMEOUT_MS (60 * 1000)	
 #define WAIT_CHECK_EVERY_MS 10
 
-static int wait_for_clear_channel (int channel, int nowait, int slottime, int persist)
+static int wait_for_clear_channel (int chan, int slottime, int persist)
 {
-	int r;
-	int n;
-
-
-	n = 0;
+	int n = 0;
 
 start_over_again:
 
-	while (hdlc_rec_data_detect_any(channel)) {
+	while (hdlc_rec_data_detect_any(chan)) {
 	  SLEEP_MS(WAIT_CHECK_EVERY_MS);
 	  n++;
 	  if (n > (WAIT_TIMEOUT_MS / WAIT_CHECK_EVERY_MS)) {
@@ -1033,41 +1183,52 @@ start_over_again:
 	  }
 	}
 
-//TODO1.2:  rethink dwait.
+//TODO:  rethink dwait.
 
 /*
  * Added in version 1.2 - for transceivers that can't
  * turn around fast enough when using squelch and VOX.
  */
 
-	if (save_audio_config_p->achan[channel].dwait > 0) {
-	  SLEEP_MS (save_audio_config_p->achan[channel].dwait * 10);
+	if (save_audio_config_p->achan[chan].dwait > 0) {
+	  SLEEP_MS (save_audio_config_p->achan[chan].dwait * 10);
 	}
 
-	if (hdlc_rec_data_detect_any(channel)) {
+	if (hdlc_rec_data_detect_any(chan)) {
 	  goto start_over_again;
 	}
 
-	if ( ! nowait) {
+/*
+ * Wait random time.
+ * Proceed to transmit sooner if anything shows up in high priority queue.
+ */
+	while (tq_peek(chan, TQ_PRIO_0_HI) == NULL) {
+	  int r;
 
-	  while (1) {
+	  SLEEP_MS (slottime * 10);
 
-	    SLEEP_MS (slottime * 10);
-
-	    if (hdlc_rec_data_detect_any(channel)) {
-	      goto start_over_again;
-	    }
-
-	    r = rand() & 0xff;
-	    if (r <= persist) {
-	      break;
- 	    }	
+	  if (hdlc_rec_data_detect_any(chan)) {
+	    goto start_over_again;
 	  }
+
+	  r = rand() & 0xff;
+	  if (r <= persist) {
+	    break;
+ 	  }	
 	}
 
-// TODO1.2
+/*
+ * This is to prevent two channels from transmitting at the same time
+ * thru a stereo audio device.
+ * We are not clever enough to combine two audio streams.
+ * They must go out one at a time.
+ * Documentation recommends using separate audio device for each channel rather than stereo.
+ * That also allows better use of multiple cores for receiving.
+ */
 
-	while ( ! dw_mutex_try_lock(&(audio_out_dev_mutex[ACHAN2ADEV(channel)]))) {
+// TODO: review this.
+
+	while ( ! dw_mutex_try_lock(&(audio_out_dev_mutex[ACHAN2ADEV(chan)]))) {
 	  SLEEP_MS(WAIT_CHECK_EVERY_MS);
 	  n++;
 	  if (n > (WAIT_TIMEOUT_MS / WAIT_CHECK_EVERY_MS)) {