Files
MicrOBU/obu-firmware/main/test_channel.cpp
T
Ashin Walpola d2fd222a62 Sign ITS messages on the ESP32-C5 with vanetza-idf, over USB or BLE
obu-firmware is now a port of the colleague's standalone VRU station
(microbu-esp32c5/firmware, kept beside this repository and gitignored): the
vanetza-idf C-ITS stack with the TS 103 097 security entity, credentials in
NVS, the station-link v1 protocol over the native USB port (frame type 0x10
in the existing 0xAA55 framing) and over a BLE GATT peripheral, and its
ITS-G5 radio adapter. The phone still builds CAM and VAM; the board adds
GeoNetworking/BTP and signs with the provisioned authorization ticket. The
private key never leaves the board. Builds with ESP-IDF 6.0.2 only, which
vanetza-idf pins for the radio's private driver ABI. The previous C firmware
stays on disk unbuilt; a full-flash backup of the bench board is kept in
firmware-backups/ (gitignored).

Changed against the colleague's firmware, marked MicrOBU: in the sources:
- Reception unchanged for the app. vanetza-idf drops what it cannot verify
  (unsigned traffic, every RSU), so each captured frame also goes through the
  previous gn_unwrap.c and reaches the phone as link opcode V2X_RX (0x85),
  whose body is the old SERIAL_MSG_V2X_RX payload.
- Unsigned transmission still possible, with the previous geonet.c header;
  the phone chooses per message.
- Console on UART0 (CH343 port); the native USB port carries only link frames.
- BLE advertising pauses while the USB link is in use: BLE and ITS-G5 share
  one RF front end.
- NVS 80 KB (app at 0x20000). At 24 KB, with Wi-Fi settings the previous
  firmware left behind, the BLE bond could not be stored and the phone had to
  pair on every connection.
- Bench fixes: the radio queue is drained before the first PoTi (no RX and
  ~177 queue drops before); the station loop waited pdMS_TO_TICKS(5) = 0
  ticks at 100 Hz and starved the idle task; the 2.4 KB RX capture buffer is
  off the Wi-Fi task stack; BLE notifications longer than the MTU are dropped
  instead of cut short, MTU 517; serial writes are skipped with no USB host.
- Manual country policy and TX-power read-back from the previous radio setup;
  logs for BLE encryption changes and the number of stored bonds.

Verified on the bench board (COM3) with the phone over USB and BLE: CAM and
VAM, signed and unsigned, go out; reception of the sim car and the RSU's
CAM/SPATEM/MAPEM continues; the board survives app restarts and reconnects.
See docs/06-signed-its-vam-ble.md.
2026-09-23 17:27:54 +02:00

80 lines
2.9 KiB
C++

#include "test_channel.hpp"
#if CONFIG_MICROBU_TEST_CHANNEL
#include <algorithm>
namespace microbu {
link::Bytes test_channel_execute(Station& station, const link::Bytes& request) {
using link::Code;
Code result = Code::malformed;
std::deque<TestRecord> records;
link::Bytes extra;
if (!request.empty()) {
link::Reader r(request, 1);
switch (request[0]) {
case 0x01: { // MIRROR mode
const auto mode = r.u8();
if (r.done() && mode <= 2) { station.test_mirror(static_cast<Station::Mirror>(mode)); result = Code::accepted; }
break;
}
case 0x02: { // INJECT source destination gnpdu
vanetza::MacAddress source, destination;
r.bytes(source.octets.data(), 6);
r.bytes(destination.octets.data(), 6);
auto gnpdu = r.rest();
if (r.ok() && !gnpdu.empty()) result = station.test_inject(source, destination, std::move(gnpdu));
break;
}
case 0x03: { // GN_REQUEST traffic class payload
const auto tc = r.u8();
auto payload = r.rest();
if (r.ok() && !payload.empty()) result = station.test_gn_request(tc, std::move(payload));
break;
}
case 0x04: { // DRAIN
bool overflow = false;
records = station.test_drain(overflow, 1536 - 2);
result = overflow ? Code::resource_limit : Code::accepted;
break;
}
case 0x05: // RESET
station.test_reset();
result = Code::accepted;
break;
case 0x06: { // RADIO_BURST [channel u16 LE][power_quarter_db u8][mcs u8][count u16 LE][interval_ms u16 LE][payload_len u16 LE]
const auto channel = r.u16();
const auto power_quarter_db = r.u8();
const auto mcs = r.u8();
const auto count = r.u16();
const auto interval_ms = r.u16();
const auto payload_len = r.u16();
if (r.done()) {
const double power_dbm = power_quarter_db / 4.0;
result = station.test_radio_burst(channel, power_dbm, mcs, count, interval_ms, payload_len);
}
break;
}
case 0x07: { // CCA_SAMPLE [duration_ms u16 LE] -- CCA polling feasibility probe
const auto duration_ms = r.u16();
if (r.done()) result = station.test_cca_sample(duration_ms, extra);
break;
}
default:
result = Code::unknown_opcode;
}
}
link::Writer w;
w.u8(static_cast<std::uint8_t>(result));
w.u8(static_cast<std::uint8_t>(std::min<std::size_t>(records.size(), 255)));
for (const auto& record : records) {
w.u8(record.kind);
w.u16(static_cast<std::uint16_t>(record.bytes.size()));
w.bytes(record.bytes);
}
w.bytes(extra);
return w.out;
}
} // namespace microbu
#endif // CONFIG_MICROBU_TEST_CHANNEL