New NCHANNEL feature.

Author: wb2osz

CHANGES.md

@@ -6,6 +6,9 @@
 
 ### New Features: ###
 
+
+- New NCHANNEL feature to map a channel number to an external network TCP KISS TNC.  See xxx for example of a bridge to LoRa APRS.  See [APRS-LoRa-VHF-APRS-Bridge.pdf](https://github.com/wb2osz/direwolf-doc/blob/main/APRS-LoRa-VHF-APRS-Bridge.pdf) for explanation.
+
 - [http://www.aprs.org/aprs11/tocalls.txt](http://www.aprs.org/aprs11/tocalls.txt) has been abandoned since the end of 2021.  [https://github.com/aprsorg/aprs-deviceid](https://github.com/aprsorg/aprs-deviceid) is now considered to be the authoritative source of truth for the vendor/model encoding.
 
 ## Version 1.7  --  October 2023 ##

conf/generic.conf

@@ -274,7 +274,7 @@
 %C%#DTMF
 %C%
 %C%# Push to Talk (PTT) can be confusing because there are so many different cases.
-%C%# Radio-Interface-Guide.pdf  in  https://github.com/wb2osz/direwolf-doc
+%C%# https://github.com/wb2osz/direwolf-doc/blob/main/Radio-Interface-Guide.pdf
 %C%# goes into detail about the various options.
 %C%
 %L%# If using a C-Media CM108/CM119 or similar USB Audio Adapter,

src/CMakeLists.txt

@@ -79,6 +79,7 @@ list(APPEND direwolf_SOURCES
   morse.c
   multi_modem.c
   waypoint.c
+  nettnc.c
   serial_port.c
   pfilter.c
   ptt.c

src/agwlib.c

@@ -357,7 +357,7 @@ static void * tnc_listen_thread (void *arg)
 /*
  * Take some precautions to guard against bad data which could cause problems later.
  */
-	    if (cmd.hdr.portx < 0 || cmd.hdr.portx >= MAX_CHANS) {
+	    if (cmd.hdr.portx < 0 || cmd.hdr.portx >= MAX_TOTAL_CHANS) {
 	      text_color_set(DW_COLOR_ERROR);
 	      dw_printf ("Invalid channel number, %d, in command '%c', from network TNC.\n",
 			cmd.hdr.portx, cmd.hdr.datakind);

src/appserver.c

@@ -597,7 +597,7 @@ void agw_cb_G_port_information (int num_chan_avail, char *chan_descriptions[])
 	    if (strncasecmp(p, "Port", 4) == 0 && isdigit(p[4])) {
 
 	      int chan = atoi(p+4) - 1;	// "Port1" is our channel 0.
-	      if (chan >= 0 && chan < MAX_CHANS) {
+	      if (chan >= 0 && chan < MAX_TOTAL_CHANS) {
 
 	        char *desc = p + 4;
 	        while (*desc != '\0' && (*desc == ' ' || isdigit(*desc))) {

src/aprs_tt.c

@@ -95,8 +95,8 @@
 
 #define MAX_MSG_LEN 100
 
-static char msg_str[MAX_CHANS][MAX_MSG_LEN+1];
-static int msg_len[MAX_CHANS];
+static char msg_str[MAX_RADIO_CHANS][MAX_MSG_LEN+1];
+static int msg_len[MAX_RADIO_CHANS];
 
 static int parse_fields (char *msg);
 static int parse_callsign (char *e);
@@ -185,7 +185,7 @@ void aprs_tt_init (struct tt_config_s *p, int debug)
 	// TODO: Keep ptr instead of making a copy.
 	memcpy (&tt_config, p, sizeof(struct tt_config_s));
 #endif
-	for (c=0; c<MAX_CHANS; c++) {	
+	for (c=0; c<MAX_RADIO_CHANS; c++) {
 	  msg_len[c] = 0;
 	  msg_str[c][0] = '\0';
 	}
@@ -226,7 +226,7 @@ void aprs_tt_button (int chan, char button)
 {
 	static int poll_period = 0;
 
-	assert (chan >= 0 && chan < MAX_CHANS);
+	assert (chan >= 0 && chan < MAX_RADIO_CHANS);
 
 
 	//if (button != '.') {

src/atest.c

@@ -231,7 +231,7 @@ int main (int argc, char *argv[])
 	my_audio_config.adev[0].bits_per_sample = DEFAULT_BITS_PER_SAMPLE;	
 
 
-	for (channel=0; channel<MAX_CHANS; channel++) {
+	for (channel=0; channel<MAX_RADIO_CHANS; channel++) {
 
 	  my_audio_config.achan[channel].modem_type = MODEM_AFSK;
 
@@ -628,9 +628,10 @@ int main (int argc, char *argv[])
 	dw_printf ("%d samples per second.  %d bits per sample.  %d audio channels.\n",
 		my_audio_config.adev[0].samples_per_sec,
 		my_audio_config.adev[0].bits_per_sample,
-		my_audio_config.adev[0].num_channels);
+		(int)(my_audio_config.adev[0].num_channels));
+	// nnum_channels is known to be 1 or 2.
 	one_filetime = (double) wav_data.datasize /
-		((my_audio_config.adev[0].bits_per_sample / 8) * my_audio_config.adev[0].num_channels * my_audio_config.adev[0].samples_per_sec);
+		((my_audio_config.adev[0].bits_per_sample / 8) * (int)(my_audio_config.adev[0].num_channels) * my_audio_config.adev[0].samples_per_sec);
 	total_filetime += one_filetime;
 
 	dw_printf ("%d audio bytes in file.  Duration = %.1f seconds.\n",
@@ -654,7 +655,7 @@ int main (int argc, char *argv[])
           int audio_sample;
           int c;
 
-          for (c=0; c<my_audio_config.adev[0].num_channels; c++)
+          for (c=0; c<(int)(my_audio_config.adev[0].num_channels); c++)
           {
 
             /* This reads either 1 or 2 bytes depending on */
@@ -921,7 +922,7 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 void ptt_set (int ot, int chan, int ptt_signal)
 {
 	// Should only get here for DCD output control.
-	static double dcd_start_time[MAX_CHANS];
+	static double dcd_start_time[MAX_RADIO_CHANS];
 
 	if (d_o_opt) {
 	  double t = (double)sample_number / my_audio_config.adev[0].samples_per_sec;

src/audio.c

@@ -257,7 +257,7 @@ int audio_open (struct audio_s *pa)
 	  if (pa->adev[a].bits_per_sample == 0)
 	    pa->adev[a].bits_per_sample = DEFAULT_BITS_PER_SAMPLE;
 
-	  for (chan=0; chan<MAX_CHANS; chan++) {
+	  for (chan=0; chan<MAX_RADIO_CHANS; chan++) {
 	    if (pa->achan[chan].mark_freq == 0)
 	      pa->achan[chan].mark_freq = DEFAULT_MARK_FREQ;
 

src/audio.h

@@ -16,7 +16,7 @@
 #include <hamlib/rig.h>
 #endif
 
-#include "direwolf.h"		/* for MAX_CHANS used throughout the application. */
+#include "direwolf.h"		/* for MAX_RADIO_CHANS and MAX_TOTAL_CHANS used throughout the application. */
 #include "ax25_pad.h"		/* for AX25_MAX_ADDR_LEN */
 #include "version.h"
 
@@ -59,7 +59,7 @@ typedef enum retry_e {
 enum medium_e { MEDIUM_NONE = 0,	// Channel is not valid for use.
 		MEDIUM_RADIO,		// Internal modem for radio.
 		MEDIUM_IGATE,		// Access IGate as ordinary channel.
-		MEDIUM_NETTNC };	// Remote network TNC.  (possible future)
+		MEDIUM_NETTNC };	// Remote network TNC.  (new in 1.8)
 
 
 typedef enum sanity_e { SANITY_APRS, SANITY_AX25, SANITY_NONE } sanity_t;
@@ -139,10 +139,19 @@ struct audio_s {
 	/* originally a "channel" was always connected to an internal modem. */
 	/* In version 1.6, this is generalized so that a channel (as seen by client application) */
 	/* can be connected to something else.  Initially, this will allow application */
-	/* access to the IGate.  Later we might have network TNCs or other internal functions. */
+	/* access to the IGate.  In version 1.8 we add network KISS TNC. */
+
+	// Watch out for maximum number of channels.
+	//	MAX_CHANS - Originally, this was 6 for internal modem adio channels. Has been phased out.
+	// After adding virtual channels (IGate, network TNC), this is split into two different numbers:
+	//	MAX_RADIO_CHANNELS - For internal modems.
+	//	MAX_TOTAL_CHANNELS - limited by KISS channels/ports.  Needed for digipeating, filtering, etc.
 
 	// Properties for all channels.
 
+	char mycall[MAX_TOTAL_CHANS][AX25_MAX_ADDR_LEN];  /* Call associated with this radio channel. */
+							/* Could all be the same or different. */
+
 	enum medium_e chan_medium[MAX_TOTAL_CHANS];
 					// MEDIUM_NONE for invalid.
 					// MEDIUM_RADIO for internal modem.  (only possibility earlier)
@@ -154,6 +163,14 @@ struct audio_s {
 					/* Redundant but it makes things quicker and simpler */
 					/* than always searching thru above. */
 
+	// Applies only to network TNC type channels.
+
+	char nettnc_addr[MAX_TOTAL_CHANS][80];		// Network TNC address:  hostname or IP addr.
+
+	int nettnc_port[MAX_TOTAL_CHANS];		// Network TNC TCP port.
+
+
+
 	/* Properties for each radio channel, common to receive and transmit. */
 	/* Can be different for each radio channel. */
 
@@ -171,8 +188,6 @@ struct audio_s {
 	    // int audio_source;	// Default would be [0,1,2,3,4,5]
 
 	    // What else should be moved out of structure and enlarged when NETTNC is implemented.  ???
-	    char mycall[AX25_MAX_ADDR_LEN];      /* Call associated with this radio channel. */
-                                	/* Could all be the same or different. */
 
 
 	    enum modem_t { MODEM_AFSK, MODEM_BASEBAND, MODEM_SCRAMBLE, MODEM_QPSK, MODEM_8PSK, MODEM_OFF, MODEM_16_QAM, MODEM_64_QAM, MODEM_AIS, MODEM_EAS } modem_type;
@@ -381,7 +396,7 @@ struct audio_s {
 
 	    int fulldup;		/* Full Duplex. */
 
-	} achan[MAX_CHANS];
+	} achan[MAX_RADIO_CHANS];
 
 #ifdef USE_HAMLIB
     int rigs;               /* Total number of configured rigs */

src/audio_portaudio.c

@@ -578,7 +578,7 @@ int audio_open (struct audio_s *pa)
 		if (pa->adev[a].bits_per_sample == 0)
 			pa->adev[a].bits_per_sample = DEFAULT_BITS_PER_SAMPLE;
 
-		for (chan = 0; chan < MAX_CHANS; chan++) {
+		for (chan = 0; chan < MAX_RADIO_CHANS; chan++) {
 			if (pa->achan[chan].mark_freq == 0)
 				pa->achan[chan].mark_freq = DEFAULT_MARK_FREQ;