Minor bug fixes and some restructuring

1 files changed, 118 insertions, 199 deletions

diff --git a/listen/opentracdump.c b/listen/opentracdump.c
index 953618b..7a76df2 100644
--- a/listen/opentracdump.c
+++ b/listen/opentracdump.c
@@ -1,6 +1,7 @@
 /* OpenTRAC packet decoding by Scott Miller, N1VG
    Copyright (c) 2003 Scott Miller
    Protocol v1.0 draft, Modified 19 Jun 2003
+   Released under the Modified BSD license
 */
 
 #include <stdio.h>
@@ -11,42 +12,12 @@
 #define MAX_UNIT_INDEX 28
 
 const char *units[]={"Volts","Amperes","Watts","Kelvins","Meters","Seconds",
-		"Meters/Second","Liters","Kilograms","Bits/Second",
-		"Bytes","Radians","Radians/Second","Square Meters",
-		"Joules","Newtons","Pascals","Hertz","Meters/Sec^2",
-		"Grays","Lumens","Cubic Meters/Second","Pascal Seconds",
-		"Kilograms/Meter^3","Radians/Second^2","Coulombs",
+		"Meters/Second","Liters","Kilograms","Bits/Second","Bytes","Radians",
+		"Radians/Second","Square Meters","Joules","Newtons","Pascals","Hertz",
+		"Meters/Sec^2","Grays","Lumens","Cubic Meters/Second",
+		"Pascal Seconds","Kilograms/Meter^3","Radians/Second^2","Coulombs",
 		"Farads","Siemens","Count"};
 		
-// Return values: 0 = OK, -1 = Couldn't Decode, -2 = Invalid Data
-
-int decode_sequence(unsigned char *element, int element_len);
-int decode_origination(unsigned char *element, int element_len);
-int decode_entityid(unsigned char *element, int element_len);
-int decode_position(unsigned char *element, int element_len);
-int decode_timestamp(unsigned char *element, int element_len);
-int decode_comment(unsigned char *element, int element_len);
-int decode_courseandspeed(unsigned char *element, int element_len);
-int decode_ambiguity(unsigned char *element, int element_len);
-int decode_country(unsigned char *element, int element_len);
-int decode_displayname(unsigned char *element, int element_len);
-int decode_waypoint(unsigned char *element, int element_len);
-int decode_symbol(unsigned char *element, int element_len);
-int decode_pathtrace(unsigned char *element, int element_len);
-int decode_heardby(unsigned char *element, int element_len);
-int decode_availablenets(unsigned char *element, int element_len);
-int decode_maidenhead(unsigned char *element, int element_len);
-int decode_gpsquality(unsigned char *element, int element_len);
-int decode_acreg(unsigned char *element, int element_len);
-int decode_rivergauge(unsigned char *element, int element_len);
-int decode_hazmat(unsigned char *element, int element_len);
-int flag_emergency(void);
-int flag_attention(void);
-
-int extract_ssid(unsigned char *call);
-
-int decode_units(unsigned int unitnum, unsigned char *element, int element_len);
-
 unsigned char origin_call[7]; // Who's talking
 unsigned char origin_ssid;
 unsigned char entity_call[7]; // What they're talking about
@@ -54,110 +25,25 @@ unsigned char entity_ssid;
 unsigned int  entity_serial;
 unsigned int  entity_sequence;
 
-/* Dump an OpenTRAC packet */
-void opentrac_dump(unsigned char *data, int length, int hexdump)
-{
-	int elen;
-	int etype;
-	int decoded = 0;
-	
-	lprintf(T_PROTOCOL, "OpenTRAC decode (%d bytes):\r\n", length);
-	strcpy(origin_call, "SENDER"); // Listen doesn't tell us the sender
-	origin_ssid = 0;
-	entity_serial = 0;
-	entity_sequence = 0;
-	while (decoded < length) {
-		elen = (int)*data;
-		decoded += (elen & 0x7f)+1;
-		if (elen & 0x80) { // See if it's got a 16-bit ID
-			elen = (elen & 0x7f) - 2; // Strip the extid flag
-			etype = get16(++data);
-		}
-		else {
-			elen--; // Don't count the type byte
-			etype = (int)*(data+1);
-		}
-		data+=2; // Skip to the body
-		lprintf(T_OPENTRAC, "EID 0x%0x len %d: ", etype, elen);
-		switch (etype) {
-			case (0x00): // Sequence
-				decode_sequence(data, elen);
-				break;
-			case (0x01): // Originating Station
-				decode_origination(data, elen);
-				break;
-			case (0x02): // Entity ID
-				decode_entityid(data, elen);
-				break;
-			case (0x10): // Position report
-				decode_position(data, elen);
-				break;
-			case (0x11): // Timestamp
-				decode_timestamp(data, elen);
-				break;
-			case (0x12): // Comment
-				decode_comment(data, elen);
-				break;
-			case (0x13): // Course and Speed
-				decode_courseandspeed(data, elen);
-				break;
-			case (0x14): // Positional Ambiguity
-				decode_ambiguity(data, elen);
-				break;
-			case (0x15): // Country Code
-				decode_country(data, elen);
-				break;
-			case (0x16): // Display Name
-				decode_displayname(data, elen);
-				break;
-			case (0x17): // Waypoint Name
-				decode_waypoint(data, elen);
-				break;
-			case (0x18): // Map Symbol
-				decode_symbol(data, elen);
-				break;
-			case (0x20): // Path Trace
-				decode_pathtrace(data, elen);
-				break;
-			case (0x21): // Heard-By List
-				decode_heardby(data, elen);
-				break;
-			case (0x22): // Available Networks
-				decode_availablenets(data, elen);
-				break;
-			case (0x32): // Maidenhead Locator
-				decode_maidenhead(data, elen);
-				break;
-			case (0x34): // GPS Data Quality
-				decode_gpsquality(data, elen);
-				break;
-			case (0x35): // Aircraft Registration
-				decode_acreg(data, elen);
-				break;
-			case (0x42): // River Flow Gauge
-				decode_rivergauge(data, elen);
-				break;
-			case (0x100): // Emergency/distress flag
-				flag_emergency();
-				break;
-			case (0x101): // Attention/ident flag
-				flag_attention();
-				break;
-			case (0x300): // Hazmat
-				decode_hazmat(data, elen);
-				break;
-			default: // Everything else
-				if ((etype & 0xff00) == 0x500) {
-					decode_units(etype & 0x00ff, data, elen);
-				}
-				else {
-					lprintf(T_OPENTRAC, "Unknown Element Type\r\n");
-				}
-		}
-		data+=elen;
-	}
+
+
+int extract_ssid(unsigned char *call) {
+	// Strip the SSID from the callsign and return it
+	int c, ssid;
+
+   for (c=ssid=0;c<6;c++) {
+      ssid |= (call[c] & 0x80) >> (c+2);
+      call[c] &= 0x7f;
+   }
+
+	return ssid;
 }
 
+int decode_units(unsigned int unitnum, unsigned char *element, int element_len);
+
+
+// Return values: 0 = OK, -1 = Couldn't Decode, -2 = Invalid Data
+
 int decode_sequence(unsigned char *element, int element_len) {
 	// 0x00 Sequence number - 16 bit integer
 	if (element_len != 2 && element_len != 0) return -1;
@@ -175,33 +61,22 @@ int decode_sequence(unsigned char *element, int element_len) {
 }
 
 int decode_origination(unsigned char *element, int element_len) {
-	// 0x01 Originating Station - Callsign, SSID, Sequence, and Network
-	unsigned char network;
-
-	if (element_len < 8) return -1;
-	if (element_len > 9) return -1;
-
+	// 0x01 Originating Station - Callsign, SSID, and Sequence
 	memcpy(origin_call, element, 6);
 	origin_call[6]=0;
 	origin_ssid = extract_ssid(origin_call);
-	entity_sequence = get16(element+6);
+	if (element_len == 8) entity_sequence = get16(element+6);
+	else entity_sequence = 0;
 	strcpy(entity_call, origin_call);
 	entity_ssid = origin_ssid;
 	entity_serial = 0;
-	if (element_len == 9) {
-		network = *(element+9);
-		lprintf(T_OPENTRAC, "Origin: %s-%d seq %d net %d\r\n",origin_call,origin_ssid,entity_sequence,network);
-	}
-	else lprintf(T_OPENTRAC, "Origin: %s-%d seq %d direct\r\n",origin_call,origin_ssid,entity_sequence);
+	lprintf(T_OPENTRAC, "Origin: %s-%d seq %d\r\n",origin_call,origin_ssid,entity_sequence);
 
 	return 0;
 }
 
 int decode_entityid(unsigned char *element, int element_len) {
 	// 0x02 Entity ID
-
-   if (element_len > 10) return -1;
-
 	if (element_len > 5) {
    		memcpy(entity_call, element, 6);
 		entity_call[6]=0;
@@ -251,17 +126,18 @@ int decode_position(unsigned char *element, int element_len) {
 	double lat, lon;
 	float alt = 0;
 
-	if (element_len < 8) return -1; // Too short!
-	if (element_len > 11) return -1; // Too long!
-
 	lat = get32(element) / semicircles;
 	lon = get32(element+4) / semicircles;
+	if (lat >= 90 || lat <= -90 || lon >= 180 || lon <= -180) return -2;
 	if (element_len == 11) {
-		alt = ((((*(element+8))<<16)+get16(element+9))/100)-10000;
+		alt = ((*(element+8))<<16)+get16(element+9);
+		alt = (alt/100)-10000;
+		lprintf(T_OPENTRAC, "Position: Lat %f Lon %f Alt %f meters\r\n",
+				lat,lon,alt);
+	}
+	else {
+		lprintf(T_OPENTRAC, "Position: Lat %f Lon %f\r\n",lat,lon);
 	}
-	if (lat >= 90 || lat <= -90 || lon >= 180 || lon <= -180) return -2;
-	lprintf(T_OPENTRAC, "Position: Lat %f Lon %f Alt %f\r\n",lat,lon,alt);
-
 	return 0;
 }
 
@@ -269,11 +145,8 @@ int decode_timestamp(unsigned char *element, int element_len) {
 	// 0x11 Timestamp - Unix format time (unsigned)
 	long rawtime = 0;
 
-	if (element_len != 4) return -1;
-
 	rawtime = get32(element);
 	lprintf(T_OPENTRAC, "Time: %s", ctime(&rawtime));
-
 	return 0;
 }
 
@@ -281,8 +154,6 @@ int decode_comment(unsigned char *element, int element_len) {
 	// 0x12 Freeform Comment - ASCII text
 	char comment[127];
 
-	if (element_len > 126) return -1;  // shouldn't be possible
-
 	strncpy(comment, element, element_len);
 	comment[element_len] = 0;
 	lprintf(T_OPENTRAC, "Text: %s\r\n", comment);
@@ -296,10 +167,8 @@ int decode_courseandspeed(unsigned char *element, int element_len) {
 	unsigned int rawspeed;
 	float speed;
 
-	if (element_len != 3) return -1;
-
-	course = (*element<<1) + ((*(element+1)&0x8000) >> 15);
-	rawspeed = (get16(element+1) & 0x7ffff);
+	course = (*element<<1) | ((*(element+1)&0x80) >> 7);
+	rawspeed = get16(element+1) & 0x7fff;
 	speed = (float)rawspeed*0.072; // kph
 	if (course >= 360) return -2;
 	lprintf(T_OPENTRAC, "Course: %d Speed: %f kph\r\n", course, speed);
@@ -311,8 +180,6 @@ int decode_ambiguity(unsigned char *element, int element_len) {
 	// 0x14 Positional Ambiguity - 16 bits, in meters
 	int ambiguity;
 
-	if (element_len != 2) return -1;
-
 	ambiguity = get16(element);
 	lprintf(T_OPENTRAC, "Position +/- %d meters\r\n", ambiguity);
 	return 0;
@@ -323,9 +190,6 @@ int decode_country(unsigned char *element, int element_len) {
 	char country[3];
 	char subdivision[4];
 
-	if (element_len < 2) return -1;
-	if (element_len > 5) return -1;
-
 	strncpy(country, element, 2);
 	country[2] = 0;
 	if (element_len > 2) {
@@ -343,8 +207,6 @@ int decode_displayname(unsigned char *element, int element_len) {
 // 0x16 - Display Name (UTF-8 text)  
      char displayname[31];        
 
-     if (element_len > 30 || !element_len) return -1;
-
      strncpy(displayname, element, element_len);
      displayname[element_len] = 0;
 
@@ -356,8 +218,6 @@ int decode_waypoint(unsigned char *element, int element_len) {
 // 0x17 - Waypoint Name (up to 6 chars, uppercase)
 	char waypoint[7];
 
-	if (element_len > 6 || !element_len) return -1;         
-
 	strncpy(waypoint, element, element_len);
 	waypoint[element_len] = 0;
 
@@ -369,8 +229,6 @@ int decode_symbol(unsigned char *element, int element_len) {
 	// 0x18 Map Symbol - Packed 4-bit integers
 	int c;
 
-	if (!element_len) return -1;
-
 	lprintf(T_OPENTRAC, "Symbol: ");
 	for (c=0;c<element_len;c++) {
 		if (c>0) lprintf(T_OPENTRAC, ".");
@@ -438,17 +296,15 @@ int decode_gpsquality(unsigned char *element, int element_len) {
 	const char *validstr[] = {"Invalid", "Valid SPS", "Valid DGPS",
 						 "Valid PPS"};
 
-	if (element_len > 4 || !element_len) return -1;
-
 	fixtype = (element[0] & 0xc0) >> 6;
 	validity = (element[0] & 0x30) >> 4;
 	sats = (element[0] & 0x0f);
 	lprintf(T_OPENTRAC, "GPS: %s %s, %d sats", fixstr[fixtype],
 			validstr[validity], sats);
 	if (element_len > 1)
-		lprintf(T_OPENTRAC, " PDOP=%.1f", (float)element[1]/10);
+		lprintf(T_OPENTRAC, " HDOP=%.1f", (float)element[1]/10);
 	if (element_len > 2)
-		lprintf(T_OPENTRAC, " HDOP=%.1f", (float)element[2]/10);
+		lprintf(T_OPENTRAC, " PDOP=%.1f", (float)element[2]/10);
 	if (element_len > 3)
 		lprintf(T_OPENTRAC, " VDOP=%.1f", (float)element[3]/10);
 	lprintf(T_OPENTRAC, "\r\n");
@@ -461,8 +317,6 @@ int decode_acreg(unsigned char *element, int element_len) {
 	// 0x35 Aircraft Registration - ASCII text
 	char nnumber[9];
 
-	if (element_len > 8) return -1;
-
 	strncpy(nnumber, element, element_len);
 	nnumber[element_len]=0;
 	lprintf(T_OPENTRAC, "Aircraft ID: %s\r\n", nnumber);
@@ -477,8 +331,6 @@ int decode_rivergauge(unsigned char *element, int element_len) {
 	float flowm;
 	float heightm;
 
-	if (element_len != 4) return -1;
-
 	flow = get16(element);
 	height = get16(element+2);
 	flowm = (float)flow / 64;
@@ -523,13 +375,13 @@ int decode_units(unsigned int unitnum, unsigned char *element, int element_len)
 	return 0;
 }
 
-int flag_emergency(void) {
+int flag_emergency(unsigned char *element, int element_len) {
 	// 0x0100 - Emergency / Distress Call
 	lprintf(T_ERROR, "* * * EMERGENCY * * *\r\n");
 	return 0;
 }
 
-int flag_attention(void) {
+int flag_attention(unsigned char *element, int element_len) {
 	// 0x0101 - Attention / Ident
 	lprintf(T_PROTOCOL, " - ATTENTION - \r\n");
 	return 0;
@@ -542,8 +394,7 @@ int decode_hazmat(unsigned char *element, int element_len) {
 	if (element_len < 2) {
 		lprintf(T_OPENTRAC, "HAZMAT: Unknown Material\r\n");
 	}
-	else
-	{
+	else {
 		un_id = get16(element) & 0x3fff;
 		lprintf(T_OPENTRAC, "HAZMAT: UN%04d\r\n", un_id);
 	}
@@ -563,15 +414,83 @@ int decode_maidenhead(unsigned char *element, int element_len) {
    return 0;
 }
 
-int extract_ssid(unsigned char *call) {
-	// Strip the SSID from the callsign and return it
-	int c, ssid;
 
-   for (c=ssid=0;c<6;c++) {
-      ssid |= (call[c] & 0x80) >> (c+2);
-      call[c] &= 0x7f;
-   }
+struct {
+	unsigned int element_id;
+	unsigned char min_size;
+	unsigned char max_size;
+	int (*pDecode)(unsigned char *element, int element_len);
+} element_decode[] = {{0x00, 0, 2, decode_sequence},
+					  {0x01, 6, 8, decode_origination},
+					  {0x02, 0, 10, decode_entityid},
+					  {0x10, 8, 11, decode_position},
+					  {0x11, 4, 4, decode_timestamp},
+					  {0x12, 0, 127, decode_comment},
+					  {0x13, 3, 3, decode_courseandspeed},
+					  {0x14, 2, 2, decode_ambiguity},
+					  {0x15, 2, 5, decode_country},
+					  {0x16, 1, 30, decode_displayname},
+					  {0x17, 1, 6, decode_waypoint},
+					  {0x18, 1, 4, decode_symbol},
+					  {0x20, 0, 127, decode_pathtrace},
+					  {0x21, 0, 127, decode_heardby},
+					  {0x22, 0, 127, decode_availablenets},
+					  {0x32, 4, 6, decode_maidenhead},
+					  {0x34, 1, 4, decode_gpsquality},
+					  {0x35, 1, 8, decode_acreg},
+					  {0x42, 4, 4, decode_rivergauge},
+					  {0x100, 0, 127, flag_emergency},
+					  {0x101, 0, 127, flag_attention},
+					  {0x300, 0, 2, decode_hazmat},
+					  {0, 0, 0, NULL}}, *element_decode_ptr;
 
-	return ssid;
-}
 
+/* Dump an OpenTRAC packet */
+void opentrac_dump(unsigned char *data, int length, int hexdump)
+{
+	int elen;
+	int etype;
+	int decoded = 0;
+	
+	lprintf(T_PROTOCOL, "OpenTRAC decode (%d bytes):\r\n", length);
+	strcpy(origin_call, "SENDER"); // Listen doesn't tell us the sender
+	origin_ssid = 0;
+	entity_serial = 0;
+	entity_sequence = 0;
+	while (decoded < length) {
+		elen = (int)*data;
+		decoded += (elen & 0x7f)+1;
+		if (elen & 0x80) { // See if it's got a 16-bit ID
+			elen = (elen & 0x7f) - 2; // Strip the extid flag
+			etype = get16(++data);
+		}
+		else {
+			elen--; // Don't count the type byte
+			etype = (int)*(data+1);
+		}
+		data+=2; // Skip to the body
+		lprintf(T_OPENTRAC, "EID 0x%0x len %d: ", etype, elen);
+		for (element_decode_ptr = element_decode; element_decode_ptr->pDecode != NULL; element_decode_ptr++) {
+			if (etype == element_decode_ptr->element_id) {
+				if (elen < element_decode_ptr->min_size || elen > element_decode_ptr->max_size) {
+					lprintf(T_OPENTRAC, "Invalid element length\r\n");
+				}
+				else {
+					if (element_decode_ptr->pDecode(data, elen)) {
+						lprintf(T_OPENTRAC, "Unable to decode\r\n");
+					}
+				}
+				break;
+			}
+		}
+		if (element_decode_ptr->pDecode == NULL) {
+			if ((etype & 0xff00) == 0x500) {
+				decode_units(etype & 0x00ff, data, elen);
+			}
+			else {
+				lprintf(T_OPENTRAC, "Unknown element type - unable to decode.\r\n");
+			}
+		}
+		data+=elen;
+	}
+}