Assorted minor cleanups.

Author: wb2osz

README.md

@@ -9,7 +9,7 @@ Why waste $200 and settle for mediocre receive performance from a 1980's technol
 
 ![](tnc-test-cd-results.png)
 
-Dire Wolf now includes [FX.25](https://en.wikipedia.org/wiki/FX.25_Forward_Error_Correction) which adds Forward Error Correction (FEC) in a way that is completely compatible with existing systems.  If both ends are capable of FX.25, your information will continue to get through under conditions where regular AX.25 is completely useless.
+Dire Wolf now includes [FX.25](https://en.wikipedia.org/wiki/FX.25_Forward_Error_Correction) which adds Forward Error Correction (FEC) in a way that is completely compatible with existing systems.  If both ends are capable of FX.25, your information will continue to get through under conditions where regular AX.25 is completely useless. This was originally developed for satellites and is now seeing widespread use on HF.
 
 ![](fx25.png)
 
@@ -80,7 +80,21 @@ It can also be used as a virtual TNC for other applications such as [APRSIS32](h
 
 
 
-- **Standard 300, 1200 & 9600 bps modems and more.**
+- **Modems:**
+
+    300 bps AFSK for HF
+
+    1200 bps AFSK most common for VHF/UHF
+
+    2400 & 4800 bps PSK
+
+    9600 bps GMSK/G3RUH
+
+    AIS reception
+
+    EAS SAME reception
+
+
 
 - **DTMF ("Touch Tone") Decoding and Encoding.**
 

conf/generic.conf

@@ -369,10 +369,11 @@
 %W%
 %C%#
 %C%# It is sometimes possible to recover frames with a bad FCS.
-%C%# This applies to all channels.
+%C%# This is not a global setting.
+%C%# It applies only the the most recent CHANNEL specified.
 %C%#
-%C%#	0  [NONE] - Don't try to repair.
-%C%#	1  [SINGLE] - Attempt to fix single bit error.  (default)
+%C%#	0 - Don't try to repair.
+%C%#	1 - Attempt to fix single bit error.  (default)
 %C%#	... see User Guide for more values and in-depth discussion.
 %C%#
 %C%

src/atest.c

@@ -2,7 +2,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2011, 2012, 2013, 2014, 2015, 2016, 2019, 2021  John Langner, WB2OSZ
+//    Copyright (C) 2011, 2012, 2013, 2014, 2015, 2016, 2019, 2021, 2022  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
@@ -23,11 +23,11 @@
  *
  * Name:        atest.c
  *
- * Purpose:     Test fixture for the AFSK demodulator.
+ * Purpose:     Test fixture for the Dire Wolf demodulators.
  *
  * Inputs:	Takes audio from a .WAV file instead of the audio device.
  *
- * Description:	This can be used to test the AFSK demodulator under
+ * Description:	This can be used to test the demodulators under
  *		controlled and reproducible conditions for tweaking.
  *	
  *		For example
@@ -107,7 +107,7 @@ struct wav_header {             /* .WAV file header. */
 					/* 8 bit samples are unsigned bytes */
 					/* in range of 0 .. 255. */
 
- 					/* 16 bit samples are signed short */
+ 					/* 16 bit samples are little endian signed short */
 					/* in range of -32768 .. +32767. */
 
 static struct {
@@ -765,7 +765,7 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 	unsigned char *pinfo;
 	int info_len;
 	int h;
-	char heard[AX25_MAX_ADDR_LEN];
+	char heard[2 * AX25_MAX_ADDR_LEN + 20];
 	char alevel_text[AX25_ALEVEL_TO_TEXT_SIZE];
 
 	packets_decoded_one++;
@@ -810,6 +810,23 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 	}
 	ax25_alevel_to_text (alevel, alevel_text);
 
+	/* As suggested by KJ4ERJ, if we are receiving from */
+	/* WIDEn-0, it is quite likely (but not guaranteed), that */
+	/* we are actually hearing the preceding station in the path. */
+
+	if (h >= AX25_REPEATER_2 &&
+	      strncmp(heard, "WIDE", 4) == 0 &&
+	      isdigit(heard[4]) &&
+	      heard[5] == '\0') {
+
+	  char probably_really[AX25_MAX_ADDR_LEN];
+	  ax25_get_addr_with_ssid(pp, h-1, probably_really);
+
+	  strlcat (heard, " (probably ", sizeof(heard));
+	  strlcat (heard, probably_really, sizeof(heard));
+	  strlcat (heard, ")", sizeof(heard));
+	}
+
 	if (my_audio_config.achan[chan].fix_bits == RETRY_NONE && my_audio_config.achan[chan].passall == 0) {
 	  dw_printf ("%s audio level = %s     %s\n", heard, alevel_text, spectrum);
 	}
@@ -877,7 +894,7 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 
 
 
-#if 1		// temp experiment  	TODO: remove this.
+#if 0		// temp experiment
 
 #include "decode_aprs.h"
 #include "log.h"
@@ -886,7 +903,7 @@ void dlq_rec_frame (int chan, int subchan, int slice, packet_t pp, alevel_t alev
 
 	  decode_aprs_t A;
 
-	  decode_aprs (&A, pp, 0, 0);
+	  decode_aprs (&A, pp, 0, NULL);
 
 	  // Temp experiment to see how different systems set the RR bits in the source and destination.
 	  // log_rr_bits (&A, pp);

src/audio_stats.c

@@ -65,7 +65,6 @@
 
 #include "audio_stats.h"
 #include "textcolor.h"
-#include "dtime_now.h"
 #include "demod.h"		/* for alevel_t & demod_get_audio_level() */
 
 

src/config.c

@@ -2864,6 +2864,9 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 /*
  * CFILTER  from-chan  to-chan  filter_specification_expression
+ *
+ * Why did I put this here?
+ * What would be a useful use case?  Perhaps block by source or destination?
  */
 
 	  else if (strcasecmp(t, "CFILTER") == 0) {

src/decode_aprs.c

@@ -140,10 +140,11 @@ static void process_comment (decode_aprs_t *A, char *pstart, int clen);
  *
  *		quiet	- Suppress error messages.
  *
- *		third_party - True when parsing a third party header.
+ *		third_party_src - Specify when parsing a third party header.
  *			(decode_aprs is called recursively.)
  *			This is mostly found when an IGate transmits a message
  *			that came via APRS-IS.
+ *			NULL when not third party payload.
  *
  * Outputs:	A->	g_symbol_table, g_symbol_code,
  *			g_lat, g_lon, 
@@ -156,11 +157,10 @@ static void process_comment (decode_aprs_t *A, char *pstart, int clen);
  *
  *------------------------------------------------------------------*/
 
-void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, int third_party)
+void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, char *third_party_src)
 {
-	//dw_printf ("DEBUG decode_aprs quiet=%d, third_party=%d\n", quiet, third_party);
+	//dw_printf ("DEBUG decode_aprs quiet=%d, third_party=%p\n", quiet, third_party_src);
 
-	//char dest[AX25_MAX_ADDR_LEN];
 	unsigned char *pinfo;
 	int info_len;
 
@@ -229,7 +229,12 @@ void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, int third_party)
 
 	  packet_t pp_payload = ax25_from_text ((char*)pinfo+1, 0);
 	  if (pp_payload != NULL) {
-	    decode_aprs (A, pp_payload, quiet, 1);	// 1 means used recursively
+	    char payload_src[AX25_MAX_ADDR_LEN];
+	    memset(payload_src, 0, sizeof(payload_src));
+	    memcpy(payload_src, (char*)pinfo+1, sizeof(payload_src)-1);
+	    char *q = strchr(payload_src, '>');
+	    if (q != NULL) *q = '\0';
+	    decode_aprs (A, pp_payload, quiet, payload_src);	// 1 means used recursively
 	    ax25_delete (pp_payload);
 	    return;
 	  }
@@ -243,8 +248,12 @@ void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, int third_party)
 /*
  * Extract source and destination including the SSID.
  */
-	
-	ax25_get_addr_with_ssid (pp, AX25_SOURCE, A->g_src);
+	if (third_party_src != NULL) {
+	    strlcpy (A->g_src, third_party_src, sizeof(A->g_src));
+	}
+	else {
+	    ax25_get_addr_with_ssid (pp, AX25_SOURCE, A->g_src);
+	}
 	ax25_get_addr_with_ssid (pp, AX25_DESTINATION, A->g_dest);
 
 	//dw_printf ("DEBUG decode_aprs source=%s, dest=%s\n", A->g_src, A->g_dest);
@@ -5176,7 +5185,7 @@ int main (int argc, char *argv[])
 	        ax25_safe_print ((char *)pinfo, info_len, 1);	// Display non-ASCII to hexadecimal.
 	        dw_printf ("\n");
 
-	        decode_aprs (&A, pp, 0, 0);			// Extract information into structure.
+	        decode_aprs (&A, pp, 0, NULL);			// Extract information into structure.
 
 	        decode_aprs_print (&A);			// Now print it in human readable format.
 
@@ -5197,7 +5206,7 @@ int main (int argc, char *argv[])
 	      if (pp != NULL) {
 	        decode_aprs_t A;
 
-	        decode_aprs (&A, pp, 0, 0);	// Extract information into structure.
+	        decode_aprs (&A, pp, 0, NULL);	// Extract information into structure.
 
 	        decode_aprs_print (&A);		// Now print it in human readable format.
 

src/decode_aprs.h

@@ -77,7 +77,7 @@ typedef struct decode_aprs_s {
 				message_subtype_directed_query
 		} g_message_subtype;	/* Various cases of the overloaded "message." */
 
-	char g_message_number[8];	/* Message number.  Should be 1 - 5 alphanumeric characters if used. */
+	char g_message_number[12];	/* Message number.  Should be 1 - 5 alphanumeric characters if used. */
 					/* Addendum 1.1 has new format {mm} or {mm}aa with only two */
 					/* characters for message number and an ack riding piggyback. */
 
@@ -142,9 +142,9 @@ typedef struct decode_aprs_s {
 
 
 
-extern void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, int third_party);
+extern void decode_aprs (decode_aprs_t *A, packet_t pp, int quiet, char *third_party_src);
 
 extern void decode_aprs_print (decode_aprs_t *A);
 
 
-#endif
+#endif

src/direwolf.c

@@ -1426,7 +1426,7 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 	  // we still want to decode it for logging and other processing.
 	  // Just be quiet about errors if "-qd" is set.
 
-	  decode_aprs (&A, pp, q_d_opt, 0);
+	  decode_aprs (&A, pp, q_d_opt, NULL);
 
 	  if ( ! q_d_opt ) {
 
@@ -1554,10 +1554,14 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 	}
 	else { 
 
-/* Send to Internet server if option is enabled. */
-/* Consider only those with correct CRC. */
-
-	  if (ax25_is_aprs(pp) && retries == RETRY_NONE) {
+/*
+ * Send to the IGate processing.
+ * Use only those with correct CRC; We don't want to spread corrupted data!
+ * Our earlier "fix bits" hack could allow corrupted information to get thru.
+ * However, if it used FEC mode (FX.25. IL2P), we have much higher level of
+ * confidence that it is correct.
+ */
+	  if (ax25_is_aprs(pp) && ( retries == RETRY_NONE || is_fx25) ) {
 
 	    igate_send_rec_packet (chan, pp);
 	  }
@@ -1572,24 +1576,23 @@ void app_process_rec_packet (int chan, int subchan, int slice, packet_t pp, alev
 
 
 /*
- * APRS digipeater.
+ * Send to APRS digipeater.
  * Use only those with correct CRC; We don't want to spread corrupted data!
+ * Our earlier "fix bits" hack could allow corrupted information to get thru.
+ * However, if it used FEC mode (FX.25. IL2P), we have much higher level of
+ * confidence that it is correct.
  */
-
-// TODO: Should also use anything received with FX.25 because it is known to be good.
-// Our earlier "fix bits" hack could allow corrupted information to get thru.
-
-	  if (ax25_is_aprs(pp) && retries == RETRY_NONE) {
+	  if (ax25_is_aprs(pp) && ( retries == RETRY_NONE || is_fx25) ) {
 
 	    digipeater (chan, pp);
 	  }
 
 /*
  * Connected mode digipeater.
- * Use only those with correct CRC.
+ * Use only those with correct CRC (or using FEC.)
  */
 
-	  if (retries == RETRY_NONE) {
+	  if (retries == RETRY_NONE || is_fx25) {
 
 	    cdigipeater (chan, pp);
 	  }