misc/adsb-tools
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Add mode AC handling, and clean up the parsers and serializers to avoid duplication.

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This commit is contained in:
Ian Gulliver
2016-02-27 21:50:15 -08:00
parent b7e32d1b48
commit 92334724f0
10 changed files with 176 additions and 296 deletions
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103
adsbus/beast.c
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@@ -9,29 +9,19 @@
#include "beast.h"
struct __attribute__((packed)) beast_common_overlay {
struct __attribute__((packed)) beast_overlay {
uint8_t one_a;
uint8_t type;
};
struct __attribute__((packed)) beast_mode_s_short_overlay {
struct beast_common_overlay common;
uint8_t mlat_timestamp[6];
uint8_t rssi;
uint8_t payload[7];
};
struct __attribute__((packed)) beast_mode_s_long_overlay {
struct beast_common_overlay common;
uint8_t mlat_timestamp[6];
uint8_t rssi;
uint8_t payload[14];
};
struct beast_parser_state {
struct packet_mlat_state mlat_state;
};
#define BEAST_MLAT_MHZ 12
static uint64_t beast_parse_mlat(uint8_t *mlat_timestamp) {
return (
((uint64_t) mlat_timestamp[0]) << 40 |
@@ -78,46 +68,32 @@ static void beast_escape(struct buf *out, const struct buf *in) {
}
}
static bool beast_parse_mode_s_short(struct buf *buf, struct packet *packet, struct beast_parser_state *state) {
static bool beast_parse_packet(struct buf *buf, struct packet *packet, struct beast_parser_state *state, enum packet_type type) {
struct buf buf2 = BUF_INIT;
ssize_t in_bytes = beast_unescape(&buf2, buf, sizeof(struct beast_mode_s_short_overlay));
size_t payload_bytes = packet_payload_len[type];
ssize_t in_bytes = beast_unescape(&buf2, buf, sizeof(struct beast_overlay) + payload_bytes);
if (in_bytes < 0) {
return false;
}
struct beast_mode_s_short_overlay *overlay = (struct beast_mode_s_short_overlay *) buf_at(&buf2, 0);
packet->type = PACKET_TYPE_MODE_S_SHORT;
struct beast_overlay *overlay = (struct beast_overlay *) buf_at(&buf2, 0);
packet->type = type;
uint64_t source_mlat = beast_parse_mlat(overlay->mlat_timestamp);
packet->mlat_timestamp = packet_mlat_timestamp_scale_in(source_mlat, UINT64_C(0xffffffffffff), 12, &state->mlat_state);
packet->mlat_timestamp = packet_mlat_timestamp_scale_in(source_mlat, UINT64_C(0xffffffffffff), BEAST_MLAT_MHZ, &state->mlat_state);
packet->rssi = packet_rssi_scale_in(overlay->rssi, UINT8_MAX);
memcpy(packet->payload, overlay->payload, sizeof(overlay->payload));
memcpy(packet->payload, buf_at(&buf2, sizeof(*overlay)), payload_bytes);
buf_consume(buf, (size_t) in_bytes);
return true;
}
static bool beast_parse_mode_s_long(struct buf *buf, struct packet *packet, struct beast_parser_state *state) {
static void beast_serialize_packet(struct packet *packet, struct buf *buf, uint8_t type) {
struct buf buf2 = BUF_INIT;
ssize_t in_bytes = beast_unescape(&buf2, buf, sizeof(struct beast_mode_s_long_overlay));
if (in_bytes < 0) {
return false;
}
struct beast_mode_s_long_overlay *overlay = (struct beast_mode_s_long_overlay *) buf_at(&buf2, 0);
packet->type = PACKET_TYPE_MODE_S_LONG;
uint64_t source_mlat = beast_parse_mlat(overlay->mlat_timestamp);
packet->mlat_timestamp = packet_mlat_timestamp_scale_in(source_mlat, UINT64_C(0xffffffffffff), 12, &state->mlat_state);
packet->rssi = packet_rssi_scale_in(overlay->rssi == UINT8_MAX ? 0 : overlay->rssi, UINT8_MAX);
memcpy(packet->payload, overlay->payload, sizeof(overlay->payload));
buf_consume(buf, (size_t) in_bytes);
return true;
}
static void beast_serialize_mode_s_short(struct packet *packet, struct buf *buf) {
struct buf buf2 = BUF_INIT;
struct beast_mode_s_short_overlay *overlay = (struct beast_mode_s_short_overlay *) buf_at(&buf2, 0);
overlay->common.one_a = 0x1a;
overlay->common.type = 0x32;
memcpy(overlay->payload, packet->payload, sizeof(overlay->payload));
size_t payload_bytes = packet_payload_len[type];
struct beast_overlay *overlay = (struct beast_overlay *) buf_at(&buf2, 0);
overlay->one_a = 0x1a;
overlay->type = type;
memcpy(buf_at(&buf2, sizeof(*overlay)), packet->payload, payload_bytes);
beast_write_mlat(
packet_mlat_timestamp_scale_out(packet->mlat_timestamp, UINT64_C(0xffffffffffff), 12),
packet_mlat_timestamp_scale_out(packet->mlat_timestamp, UINT64_C(0xffffffffffff), BEAST_MLAT_MHZ),
overlay->mlat_timestamp);
if (packet->rssi) {
@@ -126,54 +102,35 @@ static void beast_serialize_mode_s_short(struct packet *packet, struct buf *buf)
overlay->rssi = UINT8_MAX;
}
buf2.length = sizeof(*overlay);
beast_escape(buf, &buf2);
}
static void beast_serialize_mode_s_long(struct packet *packet, struct buf *buf) {
struct buf buf2 = BUF_INIT;
struct beast_mode_s_long_overlay *overlay = (struct beast_mode_s_long_overlay *) buf_at(&buf2, 0);
overlay->common.one_a = 0x1a;
overlay->common.type = 0x33;
memcpy(overlay->payload, packet->payload, sizeof(overlay->payload));
beast_write_mlat(
packet_mlat_timestamp_scale_out(packet->mlat_timestamp, UINT64_C(0xffffffffffff), 12),
overlay->mlat_timestamp);
if (packet->rssi) {
overlay->rssi = (uint8_t) packet_rssi_scale_out(packet->rssi, UINT8_MAX);
} else {
overlay->rssi = UINT8_MAX;
}
buf2.length = sizeof(*overlay);
buf2.length = sizeof(*overlay) + payload_bytes;
beast_escape(buf, &buf2);
}
void beast_init() {
assert(sizeof(struct beast_parser_state) <= PARSER_STATE_LEN);
assert(sizeof(struct beast_mode_s_short_overlay) * 2 <= BUF_LEN_MAX);
assert(sizeof(struct beast_mode_s_long_overlay) * 2 <= BUF_LEN_MAX);
assert((sizeof(struct beast_overlay) + PACKET_PAYLOAD_LEN_MAX) * 2 <= BUF_LEN_MAX);
}
bool beast_parse(struct buf *buf, struct packet *packet, void *state_in) {
struct beast_parser_state *state = (struct beast_parser_state *) state_in;
struct beast_overlay *overlay = (struct beast_overlay *) buf_at(buf, 0);
if (buf->length < sizeof(struct beast_common_overlay) ||
if (buf->length < sizeof(*overlay) ||
buf_chr(buf, 0) != 0x1a) {
return false;
}
struct beast_common_overlay *overlay = (struct beast_common_overlay *) buf_at(buf, 0);
switch (overlay->type) {
case 0x31:
return beast_parse_packet(buf, packet, state, PACKET_TYPE_MODE_AC);
case 0x32:
return beast_parse_mode_s_short(buf, packet, state);
return beast_parse_packet(buf, packet, state, PACKET_TYPE_MODE_S_SHORT);
case 0x33:
return beast_parse_mode_s_long(buf, packet, state);
return beast_parse_packet(buf, packet, state, PACKET_TYPE_MODE_S_LONG);
default:
fprintf(stderr, "R %s: Unknown beast type %x\n", packet->source_id, overlay->type);
return false;
}
return false;
@@ -184,12 +141,16 @@ void beast_serialize(struct packet *packet, struct buf *buf) {
case PACKET_TYPE_NONE:
break;
case PACKET_TYPE_MODE_AC:
beast_serialize_packet(packet, buf, 0x31);
break;
case PACKET_TYPE_MODE_S_SHORT:
beast_serialize_mode_s_short(packet, buf);
beast_serialize_packet(packet, buf, 0x32);
break;
case PACKET_TYPE_MODE_S_LONG:
beast_serialize_mode_s_long(packet, buf);
beast_serialize_packet(packet, buf, 0x33);
break;
}
}