Log outer packet for Third Party messages

APRX previously only logged the inner payload of third party traffic,
which usually gets discarded on I-gate since it's got TCPIP in the
via path. This is a little confusing since it doesn't log the outer
packet carrying the third party payload.

This change adds logging of the full received packet, which gets
discarded because it's third party, before it restarts parsing the
inner packet and possibly discarding it as well if it came from the
Internet.

Author: PhirePhly

igate.c

@@ -13,6 +13,8 @@
 #include "aprx.h"
 
 
+// Verify the sanity of a TNC2 formatted call,
+//  and return a pointer to after the callsign
 const char *tnc2_verify_callsign_format(const char *t, int starok, int strictax25, const char *e)
 {
 	const char *s = t;
@@ -157,8 +159,15 @@ void verblog(const char *portname, int istx, const char *tnc2buf, int tnc2len) {
  * It does presume that the record is in a buffer that can be written on!
  */
 
-void igate_to_aprsis(const char *portname, const int tncid, const char *tnc2buf, int tnc2addrlen, int tnc2len, const int discard0, const int strictax25_)
-{
+void igate_to_aprsis(
+		const char *portname,
+		const int tncid,
+		const char *tnc2buf,
+		int tnc2addrlen,
+		int tnc2len,
+		const int discard0,
+		const int strictax25_) {
+
 	const char *tp, *t, *t0;
 	const char *s;
 	const char *ae;
@@ -170,26 +179,20 @@ void igate_to_aprsis(const char *portname, const int tncid, const char *tnc2buf,
 	ae = tp + tnc2addrlen;  // 3rd-party recursion moves ae
 	e  = tp + tnc2len;      // stays the same all the time
 
-	redo_frame_filter:;
+redo_frame_filter:;
 
 	t  = tp;
 	t0 = NULL;
 
 	/* t == beginning of the TNC2 format packet */
 
-	/*
-	 * If any of following matches, discard the packet!
-	 * next if ($axpath =~ m/^WIDE/io); # Begins with = is sourced by..
-	 * next if ($axpath =~ m/^RELAY/io);
-	 * next if ($axpath =~ m/^TRACE/io);
-	 */
+	// Check the source callsign to see if it's an invalid source
 	s = tnc2_forbidden_source_stationid(t, strictax25, e);
 	if (s)
 		t = (char *) s;
 	else {
 		/* Forbidden in source fields.. */
-		if (debug)
-			printf("TNC2 forbidden source stationid: '%.20s'\n", t);
+		if (debug) printf("TNC2 forbidden source stationid: '%.20s'\n", t);
 		goto discard;
 	}
 
@@ -198,81 +201,67 @@ void igate_to_aprsis(const char *portname, const int tncid, const char *tnc2buf,
 	if (*t == '>') {
 		++t;
 	} else {
-		if (debug)
-		    printf("TNC2 bad address format, expected '>', got: '%.20s'\n", t);
+		if (debug) printf("TNC2 bad address format, expected '>', got: '%.20s'\n", t);
 		goto discard;
 	}
 
 	s = tnc2_forbidden_destination_stationid(t, strictax25, e);
 	if (s)
 		t = (char *) s;
 	else {
-		if (debug)
-			printf("TNC2 forbidden (by REGEX) destination stationid: '%.20s'\n", t);
+		if (debug) printf("TNC2 forbidden (by REGEX) destination stationid: '%.20s'\n", t);
 		goto discard;
 	}
 
 	while (*t && t < ae) {
 		if (*t == ',') {
 			++t;
 		} else {
-			if (debug)
-				printf("TNC2 via address syntax bug, wanted ',' or ':', got: '%.20s'\n", t);
+			if (debug) printf("TNC2 via address syntax bug, wanted ',' or ':', got: '%.20s'\n", t);
 			goto discard;
 		}
 
-		/*
-		 *  next if ($axpath =~ m/RFONLY/io); # Has any of these in via fields..
-		 *  next if ($axpath =~ m/TCPIP/io);
-		 *  next if ($axpath =~ m/TCPXX/io);
-		 *  next if ($axpath =~ m/NOGATE/io); # .. drop it.
-		 */
+		// Sanity check the via hops to make sure we don't have a TCP/IP via
+		//  or a NOGATE via so we shouldn't gateway this to the Internet
 
 		s = tnc2_forbidden_via_stationid(t, strictax25, e);
 		if (!s) {
 			/* Forbidden in via fields.. */
-			if (debug)
-				printf("TNC2 forbidden VIA stationid, got: '%.20s'\n", t);
+			if (debug) printf("TNC2 forbidden VIA stationid, got: '%.20s'\n", t);
 			goto discard;
 		} else
 			t = (char *) s;
 
-
 	}
-	/* Now we have processed the address, this should be ABORT time if
-	   the current character is not ':' !  */
+
+	// We've now parsed the whole header. The next character REALLY needs to be
+	// a colon, or something is terribly wrong.
 	if (*t == ':') {
-	  /* Don't zero! */
-	  ++t;
+		/* Don't zero! */
+		++t;
 	} else {
-		if (debug)
-			printf("TNC2 address parsing did not find ':':  '%.20s'\n",t);
+		if (debug) printf("TNC2 address parsing did not find ':':  '%.20s'\n",t);
 		goto discard;
 	}
 	t0 = t;  // Start of payload
 
 	/* Now 't' points to data.. */
 
 
-/*
-	if (tnc2_forbidden_data(t)) {
-		if (debug)
-			printf("Forbidden data in TNC2 packet - REGEX match");
-		goto discard;
-	}
-*/
-
-	/* Will not relay messages that begin with '?' char: */
+	// DON'T I-gate ? APRS query packets, since that can cause bad things
 	if (*t == '?') {
-		if (debug)
-			printf("Will not relay packets where payload begins with '?'\n");
+		if (debug) printf("Will not I-gate packets where payload begins with '?'\n");
 		goto discard;
 	}
 
 	/* Messages begining with '}' char are 3rd-party frames.. */
 	if (*t == '}') {
 		/* DEBUG OUTPUT TO STDOUT ! */
 		verblog(portname, 0, tp, tnc2len);
+		// Let's log the whole packet which we received
+		// But we're definitely discarding the outer packet because it's
+		// Third party
+		rflog(portname, 'd', discard, tp, tnc2len);
 
 		strictax25 = 0;
 		/* Copy the 3rd-party message content into begining of the buffer... */
@@ -283,8 +272,8 @@ void igate_to_aprsis(const char *portname, const int tncid, const char *tnc2buf,
 		// Address end must be searched again
 		ae = memchr(tp, ':', tnc2len);
 		if (ae == NULL) {
-		  // Bad 3rd-party frame
-		  goto discard;
+			// Bad 3rd-party frame
+			goto discard;
 		}
 		tnc2addrlen = (int)(ae - tp);
 
@@ -303,24 +292,23 @@ void igate_to_aprsis(const char *portname, const int tncid, const char *tnc2buf,
 	 * future packet formats, experiments and improvements. The
 	 * packet's sender and recipient should agree on the format only.
 	 */
-	
+
 	/* _NO_ ending CRLF, the APRSIS subsystem adds it. */
 
 	discard = aprsis_queue(tp, tnc2addrlen, qTYPE_IGATED, portname, t0, e - t0); /* Send it.. */
 	/* DEBUG OUTPUT TO STDOUT ! */
 	verblog(portname, 0, tp, tnc2len);
 
 	if (0) {
- discard:;
-
+discard:;
 		discard = -1;
 	}
 
 	if (discard) {
 		erlang_add(portname, ERLANG_DROP, tnc2len, 1);
-                rflog(portname, 'd', discard, tp, tnc2len);
+		rflog(portname, 'd', discard, tp, tnc2len);
 	} else {
-                rflog(portname, 'R', discard, tp, tnc2len);
+		rflog(portname, 'R', discard, tp, tnc2len);
 	}
 }