Complete the new ICHANNEL feature.

CHANGES.md

@@ -7,6 +7,9 @@
 
 ### New Features: ###
 
+- Additional documentation location to slow down growth of main repository.  [https://github.com/wb2osz/direwolf-doc](https://github.com/wb2osz/direwolf-doc)
+
+- New ICHANNEL configuration option to map a KISS client application channel to APRS-IS. Packets from APRS-IS will be presented to client applications as the specified channel. Packets sent, by client applications, to that channel will go to APRS-IS rather than a radio channel.  Details in ***Internal-Packet-Routing.pdf***.
 
 - New variable speed option for gen_packets. For example,  "-v 5,0.1" would generate packets from 5% too slow to 5% too fast with increments of 0.1.  Some implementations might have imprecise timing.  Use this to test how well TNCs tolerate sloppy timing.
 

src/beacon.c

@@ -162,6 +162,7 @@ void beacon_init (struct audio_s *pmodem, struct misc_config_s *pconfig, struct
 	  int chan = g_misc_config_p->beacon[j].sendto_chan;
 
 	  if (chan < 0) chan = 0;	/* For IGate, use channel 0 call. */
+	  if (chan >= MAX_CHANS) chan = 0;	// For ICHANNEL, use channel 0 call.
 
 	  if (g_modem_config_p->chan_medium[chan] == MEDIUM_RADIO ||
 	      g_modem_config_p->chan_medium[chan] == MEDIUM_NETTNC) {
@@ -621,6 +622,7 @@ static void * beacon_thread (void *arg)
 	        // On reboot, the time is in the past.
 	        // After time gets set from GPS, all beacons from that interval are sent.
 	        // FIXME:  This will surely break time slotted scheduling.
+		// TODO: The correct fix will be using monotonic, rather than clock, time.
 
 	        /* craigerl: if next beacon is scheduled in the past, then set next beacon relative to now (happens when NTP pushes clock AHEAD) */
 	        /* fixme: if NTP sets clock BACK an hour, this thread will sleep for that hour */
@@ -805,11 +807,17 @@ static void beacon_send (int j, dwgps_info_t *gpsinfo)
 
 	      assert (bp->sendto_chan >= 0);
 
+	      if (g_modem_config_p->chan_medium[bp->sendto_chan] == MEDIUM_IGATE) {	// ICHANNEL uses chan 0 mycall.
+									// TODO: Maybe it should be allowed to have own.
+	        strlcpy (mycall, g_modem_config_p->achan[0].mycall, sizeof(mycall));
+	      }
+	      else {
 	        strlcpy (mycall, g_modem_config_p->achan[bp->sendto_chan].mycall, sizeof(mycall));
+	      }
 	      
 	      if (strlen(mycall) == 0 || strcmp(mycall, "NOCALL") == 0) {
 	        text_color_set(DW_COLOR_ERROR);
-	        dw_printf ("MYCALL not set for beacon in config file line %d.\n", bp->lineno);
+	        dw_printf ("MYCALL not set for beacon to chan %d in config file line %d.\n", bp->sendto_chan, bp->lineno);
 		return;
 	      }
 
@@ -1046,7 +1054,7 @@ static void beacon_send (int j, dwgps_info_t *gpsinfo)
 	  	    text_color_set(DW_COLOR_XMIT);
 	  	    dw_printf ("[ig] %s\n", beacon_text);
 
-		    igate_send_rec_packet (0, pp);
+		    igate_send_rec_packet (-1, pp);	// Channel -1 to avoid RF>IS filtering.
 		    ax25_delete (pp);
 	            break;
 

src/config.c

@@ -5594,7 +5594,8 @@ static int beacon_options(char *cmd, struct beacon_s *b, int line, struct audio_
 	    }
 	    else if (value[0] == 'r' || value[0] == 'R') {
 	       int n = atoi(value+1);
-	       if ( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE) {
+	       if (( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE)
+			&& p_audio_config->chan_medium[n] != MEDIUM_IGATE) {
 	         text_color_set(DW_COLOR_ERROR);
 	         dw_printf ("Config file, line %d: Simulated receive on channel %d is not valid.\n", line, n);
 	         continue;
@@ -5604,7 +5605,8 @@ static int beacon_options(char *cmd, struct beacon_s *b, int line, struct audio_
 	    }
 	    else if (value[0] == 't' || value[0] == 'T' || value[0] == 'x' || value[0] == 'X') {
 	      int n = atoi(value+1);
-	      if ( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE) {
+	      if (( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE)
+			&& p_audio_config->chan_medium[n] != MEDIUM_IGATE) {
 	        text_color_set(DW_COLOR_ERROR);
 	        dw_printf ("Config file, line %d: Send to channel %d is not valid.\n", line, n);
 	        continue;
@@ -5615,7 +5617,8 @@ static int beacon_options(char *cmd, struct beacon_s *b, int line, struct audio_
 	    }
 	    else {
 	       int n = atoi(value);
-	       if ( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE) {
+	       if (( n < 0 || n >= MAX_CHANS || p_audio_config->chan_medium[n] == MEDIUM_NONE)
+			&& p_audio_config->chan_medium[n] != MEDIUM_IGATE) {
 	         text_color_set(DW_COLOR_ERROR);
 	         dw_printf ("Config file, line %d: Send to channel %d is not valid.\n", line, n);
 	         continue;
@@ -5864,12 +5867,24 @@ static int beacon_options(char *cmd, struct beacon_s *b, int line, struct audio_
 
 	if (b->sendto_type == SENDTO_XMIT) {
 
-	  if ( b->sendto_chan < 0 || b->sendto_chan >= MAX_CHANS || p_audio_config->chan_medium[b->sendto_chan] == MEDIUM_NONE) {
+	  if (( b->sendto_chan < 0 || b->sendto_chan >= MAX_CHANS || p_audio_config->chan_medium[b->sendto_chan] == MEDIUM_NONE)
+		&& p_audio_config->chan_medium[b->sendto_chan] != MEDIUM_IGATE) {
 	    text_color_set(DW_COLOR_ERROR);
 	    dw_printf ("Config file, line %d: Send to channel %d is not valid.\n", line, b->sendto_chan);
 	    return (0);
 	  }
 
+	  if (p_audio_config->chan_medium[b->sendto_chan] == MEDIUM_IGATE) {  // Prevent subscript out of bounds.
+									     // Will be using call from chan 0 later.
+	    if ( strcmp(p_audio_config->achan[0].mycall, "") == 0 || 
+	         strcmp(p_audio_config->achan[0].mycall, "NOCALL") == 0 || 
+	         strcmp(p_audio_config->achan[0].mycall, "N0CALL") == 0 ) {
+
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Config file: MYCALL must be set for channel %d before beaconing is allowed.\n", 0); 
+	      return (0);
+	    }
+	  } else {
 	    if ( strcmp(p_audio_config->achan[b->sendto_chan].mycall, "") == 0 || 
 	         strcmp(p_audio_config->achan[b->sendto_chan].mycall, "NOCALL") == 0 || 
 	         strcmp(p_audio_config->achan[b->sendto_chan].mycall, "N0CALL") == 0 ) {
@@ -5879,6 +5894,7 @@ static int beacon_options(char *cmd, struct beacon_s *b, int line, struct audio_
 	      return (0);
 	    }
 	  }
+	}
 
 	return (1);
 }

src/dtime_now.c

@@ -25,9 +25,9 @@
 
 /*------------------------------------------------------------------
  *
- * Name:	dtime_now
+ * Name:	dtime_realtime
  *
- * Purpose:   	Return current time as double precision.
+ * Purpose:   	Return current wall clock time as double precision.
  *		
  * Input:	none
  *
@@ -41,10 +41,23 @@
  *		simply use double precision floating point to make usage
  *		easier.
  *
+ * NOTE:	This is not a good way to calculate elapsed time because
+ *		it can jump forward or backware via NTP or other manual setting.
+ *
+ *		Use the monotonic version for measuring elapsed time.
+ *
+ * History:	Originally I called this dtime_now.  We ran into issues where
+ *		we really cared about elapsed time, rather than wall clock time.
+ *		The wall clock time could be wrong at start up time if there
+ *		is no realtime clock or Internet access.  It can then jump
+ *		when GPS time or Internet access becomes available.
+ *		All instances of dtime_now should be replaced by dtime_realtime
+ *		if we want wall clock time, or dtime_monotonic if it is to be
+ *		used for measuring elapsed time, such as between becons.	
+ *
  *---------------------------------------------------------------*/
 
-
+double dtime_realtime (void)
-double dtime_now (void)
 {
 	double result;
 
@@ -63,6 +76,10 @@ double dtime_now (void)
 	struct timespec ts;
 
 #ifdef __APPLE__
+
+// Why didn't I use clock_gettime?
+// Not available before Max OSX 10.12?    https://github.com/gambit/gambit/issues/293
+
 	struct timeval tp;
 	gettimeofday(&tp, NULL);
 	ts.tv_nsec = tp.tv_usec * 1000;
@@ -75,6 +92,83 @@ double dtime_now (void)
 	
 #endif
 
+#if DEBUG	
+	text_color_set(DW_COLOR_DEBUG);
+	dw_printf ("dtime_realtime() returns %.3f\n", result );
+#endif
+
+	return (result);
+}
+
+
+/*------------------------------------------------------------------
+ *
+ * Name:	dtime_monotonic
+ *
+ * Purpose:   	Return montonically increasing time, which is not influenced
+ *		by the wall clock changing.  e.g. leap seconds, NTP adjustments.
+ *		
+ * Input:	none
+ *
+ * Returns:	Time as double precision, so we can get resolution
+ *		finer than one second.		
+ *
+ * Description:	Use this when calculating elapsed time.
+ *		
+ *---------------------------------------------------------------*/
+
+double dtime_monotonic (void)
+{
+	double result;
+
+#if __WIN32__
+
+// FIXME:
+// This is still returning wall clock time.
+// https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-gettickcount64
+// GetTickCount64 would be ideal but it requires Vista or Server 2008.
+// As far as I know, the current version of direwolf still works on XP.
+// 
+// As a work-around, GetTickCount could be used if we add extra code to deal
+// with the wrap around after about 49.7 days.
+// Resolution is only about 10 or 16 milliseconds.  Is that good enough?
+
+	/* 64 bit integer is number of 100 nanosecond intervals from Jan 1, 1601. */
+
+	FILETIME ft;
+	
+	GetSystemTimeAsFileTime (&ft);
+
+	result = ((( (double)ft.dwHighDateTime * (256. * 256. * 256. * 256.) + 
+			(double)ft.dwLowDateTime ) / 10000000.) - 11644473600.);
+#else
+	/* tv_sec is seconds from Jan 1, 1970. */
+
+	struct timespec ts;
+
+#ifdef __APPLE__
+
+// FIXME: Does MacOS have a monotonically increasing time?
+// https://stackoverflow.com/questions/41509505/clock-gettime-on-macos
+
+	struct timeval tp;
+	gettimeofday(&tp, NULL);
+	ts.tv_nsec = tp.tv_usec * 1000;
+	ts.tv_sec  = tp.tv_sec;
+#else
+
+// This is the only case handled properly.
+// Probably the only one that matters.
+// It is common to have a Raspberry Pi, without Internet,
+// starting up direwolf before GPS/NTP adjusts the time.
+
+	clock_gettime (CLOCK_MONOTONIC, &ts);
+#endif
+
+	result = ((double)(ts.tv_sec) + (double)(ts.tv_nsec) * 0.000000001);
+	
+#endif
+
 #if DEBUG	
 	text_color_set(DW_COLOR_DEBUG);
 	dw_printf ("dtime_now() returns %.3f\n", result );
@@ -84,6 +178,7 @@ double dtime_now (void)
 }
 
 
+
 /*------------------------------------------------------------------
  *
  * Name:	timestamp_now
@@ -104,7 +199,7 @@ double dtime_now (void)
 
 void timestamp_now (char *result, int result_size, int show_ms)
 {
-	double now = dtime_now();
+	double now = dtime_realtime();
 	time_t t = (int)now;
 	struct tm tm;
 
@@ -150,7 +245,7 @@ void timestamp_now (char *result, int result_size, int show_ms)
 
 void timestamp_user_format (char *result, int result_size, char *user_format)
 {
-	double now = dtime_now();
+	double now = dtime_realtime();
 	time_t t = (int)now;
 	struct tm tm;
 
@@ -191,7 +286,7 @@ void timestamp_user_format (char *result, int result_size, char *user_format)
 
 void timestamp_filename (char *result, int result_size)
 {
-	double now = dtime_now();
+	double now = dtime_realtime();
 	time_t t = (int)now;
 	struct tm tm;
 

src/dtime_now.h

@@ -1,9 +1,18 @@
 
 
-extern double dtime_now (void);
+extern double dtime_realtime (void);
+
+extern double dtime_monotonic (void);
+
 
 void timestamp_now (char *result, int result_size, int show_ms);
 
 void timestamp_user_format (char *result, int result_size, char *user_format);
 
 void timestamp_filename (char *result, int result_size);
+
+
+// FIXME:  remove temp workaround.
+// Needs many scattered updates.
+
+#define dtime_now dtime_realtime

src/igate.c

@@ -1,7 +1,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2013, 2014, 2015, 2016  John Langner, WB2OSZ
+//    Copyright (C) 2013, 2014, 2015, 2016, 2023  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
@@ -855,6 +855,9 @@ static void * connnect_thread (void *arg)
  * Purpose:     Send a packet to the IGate server
  *
  * Inputs:	chan	- Radio channel it was received on.
+ *			  This is required for the RF>IS filtering.
+ *		          Beaconing (sendto=ig, chan=-1) and a client app sending
+ *			  to ICHANNEL should bypass the filtering.
  *
  *		recv_pp	- Pointer to packet object.
  *			  *** CALLER IS RESPONSIBLE FOR DELETING IT! **
@@ -902,7 +905,12 @@ void igate_send_rec_packet (int chan, packet_t recv_pp)
  * In that case, the payload will have TCPIP in the path and it will be dropped.
  */
 
-	if (save_digi_config_p->filter_str[chan][MAX_CHANS] != NULL) {
+// Apply RF>IS filtering only if it same from a radio channel.
+// Beacon will be channel -1.
+// Client app to ICHANNEL is outside of radio channel range.
+
+	if (chan >= 0 && chan < MAX_CHANS && 		// in radio channel range
+		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) != 1) {
 
@@ -1517,32 +1525,36 @@ static void * igate_recv_thread (void *arg)
 
 	      int ichan = save_audio_config_p->igate_vchannel;
 
-	      // Try to parse it into a packet object.
+	      // My original poorly thoughtout idea was to parse it into a packet object,
-	      // This will contain "q constructs" and we might see an address
+	      // using the non-strict option, and send to the client app.
-	      // with two alphnumeric characters in the SSID so we must use
+	      //
-	      // the non-strict parsing.
+	      // A lot of things can go wrong with that approach.
 
-	      // Possible problem:  Up to 8 digipeaters are allowed in radio format.
+	      // (1)  Up to 8 digipeaters are allowed in radio format.
 	      //      There is a potential of finding a larger number here.
+	      //
+	      // (2)  The via path can have names that are not valid in the radio format.
+	      //      e.g.  qAC, T2HAKATA, N5JXS-F1.
+	      //      Non-strict parsing would force uppercase, truncate names too long,
+	      //      and drop unacceptable SSIDs.
+	      //
+	      // (3) The source address could be invalid for the RF address format.
+	      //     e.g.  WHO-IS>APJIW4,TCPIP*,qAC,AE5PL-JF::ZL1JSH-9 :Charles Beadfield/New Zealand{583
+	      //     That is essential information that we absolutely need to preserve.
+	      //
+	      // I think the only correct solution is to apply a third party header
+	      // wrapper so the original contents are preserved.  This will be a little
+	      // more work for the application developer.  Search for ":}" and use only
+	      // the part after that.  At this point, I don't see any value in encoding
+	      // information in the source/destination so I will just use "X>X:}" as a prefix
 
-	      packet_t pp3 = ax25_from_text((char*)message, 0);	// 0 means not strict
+	      char stemp[AX25_MAX_INFO_LEN];
+	      strlcpy (stemp, "X>X:}", sizeof(stemp));
+	      strlcat (stemp, (char*)message, sizeof(stemp));
+
+	      packet_t pp3 = ax25_from_text(stemp, 0);	// 0 means not strict
 	      if (pp3 != NULL) {
 
-	        // Should we remove the VIA path?
-
-	        // For example, we might get something like this from the server.
-	        // Lower case 'q' and non-numeric SSID are not valid for AX.25 over the air.
-	        // K1USN-1>APWW10,TCPIP*,qAC,N5JXS-F1:T#479,100,048,002,500,000,10000000
-
-	        // Should we try to retain all information and pass that along, to the best of our ability,
-	        // to the client app, or should we remove the via path so it looks like this?
-	        // K1USN-1>APWW10:T#479,100,048,002,500,000,10000000
-
-	        // For now, keep it intact and see if it causes problems.  Easy to remove like this:
-	        // while (ax25_get_num_repeaters(pp3) > 0) {
-	        //   ax25_remove_addr (pp3, AX25_REPEATER_1);
-	        // }
-
 	        alevel_t alevel;
 	        memset (&alevel, 0, sizeof(alevel));
 	        alevel.mark = -2;	// FIXME: Do we want some other special case?
@@ -1831,8 +1843,19 @@ static void maybe_xmit_packet_from_igate (char *message, int to_chan)
  * If we recently transmitted a 'message' from some station,
  * send the position of the message sender when it comes along later.
  *
+ * Some refer to this as a courtesy posit report but I don't
+ * think that is an official term.
+ *
  * If we have a position report, look up the sender and see if we should
  * bypass the normal filtering.
+ *
+ * Reference:  https://www.aprs-is.net/IGating.aspx
+ *
+ *	"Passing all message packets also includes passing the sending station's position
+ *	along with the message. When APRS-IS was small, we did this using historical position
+ *	packets. This has become problematic as it introduces historical data on to RF. 
+ *	The IGate should note the station(s) it has gated messages to RF for and pass
+ *	the next position packet seen for that station(s) to RF."
  */
 
 // TODO: Not quite this simple.  Should have a function to check for position.

src/kiss_frame.c

@@ -1,7 +1,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2013, 2014, 2017  John Langner, WB2OSZ
+//    Copyright (C) 2013, 2014, 2017, 2023  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
@@ -611,7 +611,8 @@ void kiss_process_msg (unsigned char *kiss_msg, int kiss_len, int debug, struct
 	    /* Verify that the radio channel number is valid. */
 	    /* Any sort of medium should be OK here. */
 
-	    if (chan < 0 || chan >= MAX_CHANS || save_audio_config_p->chan_medium[chan] == MEDIUM_NONE) {
+	    if ((chan < 0 || chan >= MAX_CHANS || save_audio_config_p->chan_medium[chan] == MEDIUM_NONE) 
+		&& save_audio_config_p->chan_medium[chan]  != MEDIUM_IGATE) {
 	      text_color_set(DW_COLOR_ERROR);
 	      dw_printf ("Invalid transmit channel %d from KISS client app.\n", chan);
 	      dw_printf ("\n");

src/tq.c

@@ -1,7 +1,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2011, 2012, 2014, 2015, 2016  John Langner, WB2OSZ
+//    Copyright (C) 2011, 2012, 2014, 2015, 2016, 2023  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
@@ -50,7 +50,8 @@
 #include "audio.h"
 #include "tq.h"
 #include "dedupe.h"
-
+#include "igate.h"
+#include "dtime_now.h"
 
 
 
@@ -195,6 +196,9 @@ void tq_init (struct audio_s *audio_config_p)
  *
  * Inputs:	chan	- Channel, 0 is first.
  *
+ *				New in 1.7:
+ *				Channel can be assigned to IGate rather than a radio.
+ *
  *		prio	- Priority, use TQ_PRIO_0_HI for digipeated or
  *				TQ_PRIO_1_LO for normal.
  *
@@ -247,6 +251,43 @@ void tq_append (int chan, int prio, packet_t pp)
 	}
 #endif
 
+// New in 1.7 - A channel can be assigned to the IGate rather than a radio.
+
+#ifndef DIGITEST		// avoid dtest link error
+
+	if (save_audio_config_p->chan_medium[chan] == MEDIUM_IGATE) {
+
+	  char ts[100];		// optional time stamp.
+
+	  if (strlen(save_audio_config_p->timestamp_format) > 0) {
+	    char tstmp[100];
+	    timestamp_user_format (tstmp, sizeof(tstmp), save_audio_config_p->timestamp_format);
+	    strlcpy (ts, " ", sizeof(ts));	// space after channel.
+	    strlcat (ts, tstmp, sizeof(ts));
+	  }
+	  else {
+	    strlcpy (ts, "", sizeof(ts));
+	  }
+
+	  char stemp[256];	// Formated addresses.
+	  ax25_format_addrs (pp, stemp);
+	  unsigned char *pinfo;
+	  int info_len = ax25_get_info (pp, &pinfo);
+	  text_color_set(DW_COLOR_XMIT);
+	  dw_printf ("[%d>is%s] ", chan, ts);
+	  dw_printf ("%s", stemp);			/* stations followed by : */
+	  ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
+	  dw_printf ("\n");
+
+	  igate_send_rec_packet (chan, pp);
+	  ax25_delete(pp);
+	  return;
+	}
+#endif
+
+// Normal case - put in queue for radio transmission.
+// Error if trying to transmit to a radio channel which was not configured.
+
 	if (chan < 0 || chan >= MAX_CHANS || save_audio_config_p->chan_medium[chan] == MEDIUM_NONE) {
 	  text_color_set(DW_COLOR_ERROR);
 	  dw_printf ("ERROR - Request to transmit on invalid radio channel %d.\n", chan);
@@ -281,8 +322,6 @@ void tq_append (int chan, int prio, packet_t pp)
  * The check would allow an unlimited number of other types.
  *
  * Limit was 20.  Changed to 100 in version 1.2 as a workaround.
- *
- * Implementing the 6PACK protocol is probably the proper solution.
  */
 
 	if (ax25_is_aprs(pp) && tq_count(chan,prio,"","",0) > 100) {