Record the address type details when decoding.

dump1090.h

@@ -149,6 +149,19 @@ typedef enum {
     SOURCE_ADSB,           /* data from a ADS-B extended squitter message */
 } datasource_t;
 
+/* What sort of address is this and who sent it? */
+typedef enum {
+    ADDR_ADSB_ICAO,    /* ADS-B, ICAO address, transponder sourced */
+    ADDR_ADSB_ICAO_NT, /* ADS-B, ICAO address, non-transponder */
+    ADDR_ADSB_OTHER,   /* ADS-B, other address format, non-transponder */
+    ADDR_TISB_ICAO,    /* TIS-B, ICAO address */
+    ADDR_TISB_OTHER,   /* TIS-B, other address format */
+    ADDR_TISB_ANON,    /* ADS-R/TIS-B, anonymized address */
+    ADDR_ADSR_ICAO,    /* ADS-R, ICAO address */
+    ADDR_ADSR_OTHER,   /* ADS-R, other address format */
+    ADDR_UNKNOWN       /* unknown address format */
+} addrtype_t;
+
 typedef enum {
     UNIT_FEET,
     UNIT_METERS
@@ -366,6 +379,7 @@ struct modesMessage {
     uint32_t      crc;                            // Message CRC
     int           correctedbits;                  // No. of bits corrected 
     uint32_t      addr;                           // Address Announced
+    addrtype_t    addrtype;                       // address format / source
     uint64_t      timestampMsg;                   // Timestamp of the message (12MHz clock)
     struct timespec sysTimestampMsg;              // Timestamp of the message (system time)
     int           remote;                         // If set this message is from a remote station

mode_s.c

@@ -789,6 +789,30 @@ static void decodeESIdentAndCategory(struct modesMessage *mm)
     mm->category_valid = 1;
 }
 
+// Handle setting a non-ICAO address
+static void setIMF(struct modesMessage *mm)
+{
+    mm->addr |= MODES_NON_ICAO_ADDRESS;
+    switch (mm->addrtype) {
+    case ADDR_ADSB_ICAO:
+    case ADDR_ADSB_ICAO_NT:
+        mm->addrtype = ADDR_ADSB_OTHER;
+        break;
+
+    case ADDR_TISB_ICAO:
+        mm->addrtype = ADDR_TISB_OTHER;
+        break;
+
+    case ADDR_ADSR_ICAO:
+        mm->addrtype = ADDR_ADSR_OTHER;
+        break;
+
+    default:
+        // Nothing.
+        break;
+    }
+}
+
 static void decodeESAirborneVelocity(struct modesMessage *mm, int check_imf)
 {
     // Airborne Velocity Message
@@ -797,7 +821,7 @@ static void decodeESAirborneVelocity(struct modesMessage *mm, int check_imf)
     mm->mesub = getbits(me, 6, 8);
 
     if (check_imf && getbit(me, 9))
-        mm->addr |= MODES_NON_ICAO_ADDRESS;
+        setIMF(mm);
 
     if (mm->mesub < 1 || mm->mesub > 4)
         return;
@@ -870,7 +894,7 @@ static void decodeESSurfacePosition(struct modesMessage *mm, int check_imf)
     unsigned char *me = mm->ME;
 
     if (check_imf && getbit(me, 21))
-        mm->addr |= MODES_NON_ICAO_ADDRESS;
+        setIMF(mm);
 
     mm->airground = AG_GROUND; // definitely.
     mm->cpr_lat = getbits(me, 23, 39);
@@ -899,7 +923,7 @@ static void decodeESAirbornePosition(struct modesMessage *mm, int check_imf)
     unsigned char *me = mm->ME;
 
     if (check_imf && getbit(me, 8))
-        mm->addr |= MODES_NON_ICAO_ADDRESS;
+        setIMF(mm);
 
     unsigned AC12Field = getbits(me, 9, 20);
 
@@ -974,7 +998,7 @@ static void decodeESAircraftStatus(struct modesMessage *mm, int check_imf)
         }
 
         if (check_imf && getbit(me, 56))
-            mm->addr |= MODES_NON_ICAO_ADDRESS;
+            setIMF(mm);
     }
 }
 
@@ -985,7 +1009,7 @@ static void decodeESTargetStatus(struct modesMessage *mm, int check_imf)
     mm->mesub = getbits(me, 6, 7); // an unusual message: only 2 bits of subtype
 
     if (check_imf && getbit(me, 51))
-        mm->addr |= MODES_NON_ICAO_ADDRESS;
+        setIMF(mm);
 
     if (mm->mesub == 0) { // Target state and status, V1
         // TODO: need RTCA/DO-260A
@@ -1040,7 +1064,7 @@ static void decodeESOperationalStatus(struct modesMessage *mm, int check_imf)
 
     // Aircraft Operational Status
     if (check_imf && getbit(me, 56))
-        mm->addr |= MODES_NON_ICAO_ADDRESS;
+        setIMF(mm);
 
     if (mm->mesub == 0 || mm->mesub == 1) {
         mm->opstatus.valid = 1;
@@ -1141,14 +1165,17 @@ static void decodeExtendedSquitter(struct modesMessage *mm)
     if (mm->msgtype == 18) {
         switch (mm->CF) {
         case 0: //   ADS-B ES/NT devices that report the ICAO 24-bit address in the AA field
+            mm->addrtype = ADDR_ADSB_ICAO_NT;
             break;
 
         case 1: //   Reserved for ADS-B for ES/NT devices that use other addressing techniques in the AA field
+            mm->addrtype = ADDR_ADSB_OTHER;
             mm->addr |= MODES_NON_ICAO_ADDRESS;
             break;
 
         case 2: //   Fine TIS-B message (formats are close enough to DF17 for our purposes)
             mm->source = SOURCE_TISB;
+            mm->addrtype = ADDR_TISB_ICAO;
             check_imf = 1;
             break;
 
@@ -1156,20 +1183,26 @@ static void decodeExtendedSquitter(struct modesMessage *mm)
             // TODO: decode me.
             // For now we only look at the IMF bit.
             mm->source = SOURCE_TISB;
-            if (getbit(me, 1))
+            mm->addrtype = ADDR_TISB_ICAO;
+            if (getbit(me, 1)) {
                 mm->addr |= MODES_NON_ICAO_ADDRESS;
+                mm->addrtype = ADDR_TISB_OTHER;
+            }
             return;
 
         case 5: //   TIS-B messages that relay ADS-B Messages using anonymous 24-bit addresses (format not explicitly defined, but it seems to follow DF17)
+            mm->addrtype = ADDR_TISB_ANON;
             mm->source = SOURCE_TISB;
             mm->addr |= MODES_NON_ICAO_ADDRESS;
             break;
 
         case 6: //   ADS-B rebroadcast using the same type codes and message formats as defined for DF = 17 ADS-B messages
+            mm->addrtype = ADDR_ADSR_ICAO;
             check_imf = 1;
             break;
 
         default:    // All others, we don't know the format.
+            mm->addrtype = ADDR_UNKNOWN;
             mm->addr |= MODES_NON_ICAO_ADDRESS; // assume non-ICAO
             return;
         }
@@ -1325,6 +1358,29 @@ static const char *speed_source_to_string(speed_source_t speed) {
     }
 }
 
+static const char *addrtype_to_string(addrtype_t type) {
+    switch (type) {
+    case ADDR_ADSB_ICAO:
+        return "ADS-B";
+    case ADDR_ADSB_ICAO_NT:
+        return "ADS-B, non-transponder";
+    case ADDR_ADSB_OTHER:
+        return "ADS-B, other addressing scheme";
+    case ADDR_TISB_ICAO:
+        return "TIS-B";
+    case ADDR_TISB_OTHER:
+        return "TIS-B, other addressing scheme";
+    case ADDR_TISB_ANON:
+        return "TIS-B, anonymized address";
+    case ADDR_ADSR_ICAO:
+        return "ADS-R";
+    case ADDR_ADSR_OTHER:
+        return "ADS-R, other addressing scheme";
+    default:
+        return "unknown addressing scheme";
+    }
+}
+
 static void print_hex_bytes(unsigned char *data, size_t len) {
     size_t i;
     for (i = 0; i < len; ++i) {
@@ -1562,9 +1618,9 @@ void displayModesMessage(struct modesMessage *mm) {
     printf("\n");
 
     if (mm->addr & MODES_NON_ICAO_ADDRESS) {
-        printf("  Other Address: %06X\n", mm->addr);
+        printf("  Other Address: %06X (%s)\n", mm->addr & 0xFFFFFF, addrtype_to_string(mm->addrtype));
     } else {
-        printf("  ICAO Address:  %06X\n", mm->addr);
+        printf("  ICAO Address:  %06X (%s)\n", mm->addr, addrtype_to_string(mm->addrtype));
     }
 
     if (mm->airground != AG_INVALID) {