Pass source ID through to JSON output.

adsbus/json.c

@@ -33,6 +33,7 @@ static void json_hello(struct buf *buf) {
 
 static void json_add_common(struct packet *packet, json_t *obj) {
 	json_object_set_new(obj, "type", json_string(packet_type_names[packet->type]));
+	json_object_set_new(obj, "source_id", json_string(packet->source_id));
 	if (packet->mlat_timestamp) {
 		json_object_set_new(obj, "mlat_timestamp", json_integer(packet->mlat_timestamp));
 	}

adsbus/packet.h

@@ -4,6 +4,7 @@
 
 #define PACKET_DATA_LEN_MAX 14
 struct packet {
+	char *source_id;
 	enum {
 		MODE_S_SHORT,
 		MODE_S_LONG,

adsbus/receive.c

@@ -79,7 +79,9 @@ static void receive_read(struct peer *peer) {
 		return;
 	}
 
-	struct packet packet = { 0 };
+	struct packet packet = {
+		.source_id = receive->id,
+	};
 	while (receive->parser_wrapper(receive, &packet)) {
 		send_write(&packet);
 	}