Restore airspy_adsb

adsbus/Makefile

@@ -11,5 +11,5 @@ clean:
 %.o: %.c *.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-adsbus: adsbus.o receive.o send.o incoming.o outgoing.o beast.o json.o raw.o stats.o wakeup.o opts.o common.o
-	$(CC) $(LDFLAGS) -o adsbus adsbus.o receive.o send.o incoming.o outgoing.o beast.o json.o raw.o stats.o wakeup.o opts.o common.o $(LIBS)
+adsbus: adsbus.o receive.o send.o incoming.o outgoing.o airspy_adsb.o beast.o json.o raw.o stats.o wakeup.o opts.o common.o
+	$(CC) $(LDFLAGS) -o adsbus adsbus.o receive.o send.o incoming.o outgoing.o airspy_adsb.o beast.o json.o raw.o stats.o wakeup.o opts.o common.o $(LIBS)

adsbus/airspy_adsb.c

@@ -0,0 +1,154 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "common.h"
+#include "receive.h"
+#include "airspy_adsb.h"
+
+#define SEND_MHZ 20
+
+struct __attribute__((packed)) airspy_adsb_common_overlay {
+	char mlat_timestamp[8];
+	char semicolon1;
+	char mlat_precision[2];
+	char semicolon2;
+	char rssi[4];
+	char semicolon3;
+};
+
+struct __attribute__((packed)) airspy_adsb_mode_s_short_overlay {
+	char asterisk;
+	char payload[14];
+	char semicolon;
+	struct airspy_adsb_common_overlay common;
+	char cr;
+	char lf;
+};
+
+struct __attribute__((packed)) airspy_adsb_mode_s_long_overlay {
+	char asterisk;
+	char payload[28];
+	char semicolon;
+	struct airspy_adsb_common_overlay common;
+	char cr;
+	char lf;
+};
+
+struct airspy_adsb_parser_state {
+	struct mlat_state mlat_state;
+};
+
+static bool airspy_adsb_parse_common(const struct airspy_adsb_common_overlay *overlay, struct packet *packet, struct airspy_adsb_parser_state *state) {
+	if (overlay->semicolon1 != ';' ||
+	    overlay->semicolon2 != ';' ||
+			overlay->semicolon3 != ';') {
+		return false;
+	}
+	uint16_t mlat_mhz = 2 * hex_to_int(overlay->mlat_precision, sizeof(overlay->mlat_precision) / 2);
+	packet->mlat_timestamp = mlat_timestamp_scale_in(hex_to_int(overlay->mlat_timestamp, sizeof(overlay->mlat_timestamp) / 2), UINT32_MAX, mlat_mhz, &state->mlat_state);
+	packet->rssi = rssi_scale_in(hex_to_int(overlay->rssi, sizeof(overlay->rssi) / 2), UINT16_MAX);
+	return true;
+}
+
+static bool airspy_adsb_parse_mode_s_short(struct buf *buf, struct packet *packet, struct airspy_adsb_parser_state *state) {
+	struct airspy_adsb_mode_s_short_overlay *short_overlay = (struct airspy_adsb_mode_s_short_overlay *) buf_at(buf, 0);
+	if (buf->length < sizeof(*short_overlay) ||
+			short_overlay->asterisk != '*' ||
+			short_overlay->semicolon != ';' ||
+			short_overlay->cr != '\r' ||
+			short_overlay->lf != '\n') {
+		return false;
+	}
+	if (!airspy_adsb_parse_common(&short_overlay->common, packet, state)) {
+		return false;
+	}
+	packet->type = MODE_S_SHORT;
+	hex_to_bin(packet->payload, short_overlay->payload, sizeof(short_overlay->payload) / 2);
+	buf_consume(buf, sizeof(*short_overlay));
+	return true;
+}
+
+static bool airspy_adsb_parse_mode_s_long(struct buf *buf, struct packet *packet, struct airspy_adsb_parser_state *state) {
+	struct airspy_adsb_mode_s_long_overlay *long_overlay = (struct airspy_adsb_mode_s_long_overlay *) buf_at(buf, 0);
+	if (buf->length < sizeof(*long_overlay) ||
+			long_overlay->asterisk != '*' ||
+			long_overlay->semicolon != ';' ||
+			long_overlay->cr != '\r' ||
+			long_overlay->lf != '\n') {
+		return false;
+	}
+	if (!airspy_adsb_parse_common(&long_overlay->common, packet, state)) {
+		return false;
+	}
+	packet->type = MODE_S_LONG;
+	hex_to_bin(packet->payload, long_overlay->payload, sizeof(long_overlay->payload) / 2);
+	buf_consume(buf, sizeof(*long_overlay));
+	return true;
+}
+
+static void airspy_adsb_fill_common(struct packet *packet, struct airspy_adsb_common_overlay *overlay) {
+	overlay->semicolon1 = overlay->semicolon2 = overlay->semicolon3 = ';';
+	hex_from_int(
+			overlay->mlat_timestamp,
+			mlat_timestamp_scale_out(packet->mlat_timestamp, UINT32_MAX, SEND_MHZ),
+			sizeof(overlay->mlat_timestamp) / 2);
+	hex_from_int(overlay->mlat_precision, SEND_MHZ / 2, sizeof(overlay->mlat_precision) / 2);
+	hex_from_int(overlay->rssi, rssi_scale_out(packet->rssi, UINT16_MAX), sizeof(overlay->rssi) / 2);
+}
+
+static void airspy_adsb_serialize_mode_s_short(struct packet *packet, struct buf *buf) {
+	struct airspy_adsb_mode_s_short_overlay *overlay = (struct airspy_adsb_mode_s_short_overlay *) buf_at(buf, 0);
+	overlay->asterisk = '*';
+	overlay->semicolon = ';';
+	overlay->cr = '\r';
+	overlay->lf = '\n';
+	hex_from_bin(overlay->payload, packet->payload, sizeof(overlay->payload) / 2);
+
+	airspy_adsb_fill_common(packet, &overlay->common);
+
+	buf->length = sizeof(*overlay);
+}
+
+static void airspy_adsb_serialize_mode_s_long(struct packet *packet, struct buf *buf) {
+	struct airspy_adsb_mode_s_long_overlay *overlay = (struct airspy_adsb_mode_s_long_overlay *) buf_at(buf, 0);
+	overlay->asterisk = '*';
+	overlay->semicolon = ';';
+	overlay->cr = '\r';
+	overlay->lf = '\n';
+	hex_from_bin(overlay->payload, packet->payload, sizeof(overlay->payload) / 2);
+
+	airspy_adsb_fill_common(packet, &overlay->common);
+
+	buf->length = sizeof(*overlay);
+}
+
+void airspy_adsb_init() {
+	assert(sizeof(struct airspy_adsb_parser_state) <= PARSER_STATE_LEN);
+	assert(sizeof(struct airspy_adsb_mode_s_short_overlay) < BUF_LEN_MAX);
+	assert(sizeof(struct airspy_adsb_mode_s_long_overlay) < BUF_LEN_MAX);
+}
+
+bool airspy_adsb_parse(struct buf *buf, struct packet *packet, void *state_in) {
+	struct airspy_adsb_parser_state *state = (struct airspy_adsb_parser_state *) state_in;
+
+	return (
+			airspy_adsb_parse_mode_s_short(buf, packet, state) ||
+			airspy_adsb_parse_mode_s_long(buf, packet, state));
+}
+
+void airspy_adsb_serialize(struct packet *packet, struct buf *buf) {
+	if (!packet) {
+		return;
+	}
+
+	switch (packet->type) {
+		case MODE_S_SHORT:
+			airspy_adsb_serialize_mode_s_short(packet, buf);
+			break;
+
+		case MODE_S_LONG:
+			airspy_adsb_serialize_mode_s_long(packet, buf);
+			break;
+	}
+}

adsbus/airspy_adsb.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <stdbool.h>
+
+struct buf;
+struct packet;
+
+void airspy_adsb_init();
+bool airspy_adsb_parse(struct buf *, struct packet *, void *);
+void airspy_adsb_serialize(struct packet *, struct buf *);

adsbus/receive.c

@@ -4,6 +4,7 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "airspy_adsb.h"
 #include "beast.h"
 #include "raw.h"
 
@@ -27,6 +28,10 @@ struct parser {
 	char *name;
 	parser parse;
 } parsers[] = {
+	{
+		.name = "airspy_adsb",
+		.parse = airspy_adsb_parse,
+	},
 	{
 		.name = "beast",
 		.parse = beast_parse,

adsbus/send.c

@@ -10,6 +10,7 @@
 
 #include "send.h"
 
+#include "airspy_adsb.h"
 #include "beast.h"
 #include "json.h"
 #include "raw.h"
@@ -29,6 +30,10 @@ struct serializer {
 	serializer serialize;
 	struct send *send_head;
 } serializers[] = {
+	{
+		.name = "airspy_adsb",
+		.serialize = airspy_adsb_serialize,
+	},
 	{
 		.name = "beast",
 		.serialize = beast_serialize,