From 8d8443f3dc95dc84b238282a69e45668af98f366 Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver@mutability.co.uk>
Date: Wed, 14 Sep 2016 16:54:00 +0100
Subject: [PATCH] Track the "best" addrtype we ever saw for an aircraft.

---
 dump1090.h | 15 ++++++++++-----
 track.c    |  5 +++++
 track.h    |  1 +
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/dump1090.h b/dump1090.h
index 02bb43d..c9c7d9c 100644
--- a/dump1090.h
+++ b/dump1090.h
@@ -149,16 +149,21 @@ typedef enum {
     SOURCE_ADSB,           /* data from a ADS-B extended squitter message */
 } datasource_t;
 
-/* What sort of address is this and who sent it? */
+/* What sort of address is this and who sent it?
+ * (Earlier values are higher priority)
+ */
 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_TISB_ICAO,    /* TIS-B, ICAO address */
+
+    ADDR_ADSB_OTHER,   /* ADS-B, other address format, non-transponder */
     ADDR_ADSR_OTHER,   /* ADS-R, other address format */
+    ADDR_TISB_OTHER,   /* TIS-B, other address format */
+
+    ADDR_TISB_ANON,    /* ADS-R/TIS-B, anonymized address */
+
     ADDR_UNKNOWN       /* unknown address format */
 } addrtype_t;
 
diff --git a/track.c b/track.c
index 7fc8734..7fff6f7 100644
--- a/track.c
+++ b/track.c
@@ -66,6 +66,7 @@ struct aircraft *trackCreateAircraft(struct modesMessage *mm) {
 
     // Now initialise things that should not be 0/NULL to their defaults
     a->addr = mm->addr;
+    a->addrtype = mm->addrtype;
     for (i = 0; i < 8; ++i)
         a->signalLevel[i] = 1e-5;
     a->signalNext = 0;
@@ -534,6 +535,10 @@ struct aircraft *trackUpdateFromMessage(struct modesMessage *mm)
     a->seen      = now;
     a->messages++;
 
+    // update addrtype, we only ever go towards "more direct" types
+    if (mm->addrtype < a->addrtype)
+        a->addrtype = mm->addrtype;
+
     if (mm->altitude_valid && mm->altitude_source == ALTITUDE_BARO && accept_data(&a->altitude_valid, mm->source, now)) {
         unsigned modeC = (a->altitude + 49) / 100;
         if (modeC != a->altitude_modeC) {
diff --git a/track.h b/track.h
index 1cab266..574c29f 100644
--- a/track.h
+++ b/track.h
@@ -69,6 +69,7 @@ typedef struct {
 /* Structure used to describe the state of one tracked aircraft */
 struct aircraft {
     uint32_t      addr;           // ICAO address
+    addrtype_t    addrtype;       // highest priority address type seen for this aircraft
 
     uint64_t      seen;           // Time (millis) at which the last packet was received
     long          messages;       // Number of Mode S messages received