firmware/src/platform/esp32/ESP32BLEMesh.cpp

#include "configuration.h"

#if HAS_BLE_MESH && defined(ARCH_ESP32)

#include "ESP32BLEMesh.h"
#include "main.h"
#include "mesh/Router.h"
#include "nimble/NimbleBluetooth.h"

#include "host/ble_gap.h"
#include "host/ble_hs.h"
#include "host/ble_hs_adv.h"
#include "nimble/hci_common.h"

#if BLE_MESH_USE_EXT_ADV
static_assert(BLE_MESH_ADV_TOTAL_MAX <= BLE_HCI_MAX_EXT_ADV_DATA_LEN,
              "advertisement budget must fit one NimBLE LE Set Extended Advertising Data command");
#endif

void ESP32BLEMesh::start()
{
    if (isRunning) {
        LOG_DEBUG("BLE mesh already running");
        return;
    }

    isRunning = true;
    LOG_INFO("BLE mesh started (waiting for Bluetooth ready)");
}

bool ESP32BLEMesh::platformReady()
{
    // Polled, not a callback: construction order against NimbleBluetooth is not fixed.
    // isActive(), not ble_hs_synced() - the host syncs before NimbleBluetooth::setup() registers its
    // service, and starting a scan in that window races the stack's own GAP configuration.
    return nimbleBluetooth && nimbleBluetooth->isActive();
}

void ESP32BLEMesh::onBluetoothReady()
{
    if (!isRunning)
        return;

    startScanning();
    LOG_INFO("BLE mesh Bluetooth ready, scanning");
}

void ESP32BLEMesh::stop()
{
    if (!isRunning)
        return;

    platformEndAdvertising();
    stopScanning();
    isRunning = false;
    LOG_INFO("BLE mesh stopped");
}

#if BLE_MESH_USE_EXT_ADV
bool ESP32BLEMesh::configureAdvInstance()
{
    if (advInstanceConfigured)
        return true;

    struct ble_gap_ext_adv_params params = {};
    // legacy_pdu must stay 0, or the payload is back to the 31-byte limit, which cannot hold a mesh
    // frame at all.
    params.connectable = 0;
    params.scannable = 0;
    params.directed = 0;
    params.high_duty_directed = 0;
    params.legacy_pdu = 0;
    params.anonymous = 0;
    params.include_tx_power = 0;
    params.scan_req_notif = 0;
    params.itvl_min = BLE_MESH_ADV_INTERVAL;
    params.itvl_max = BLE_MESH_ADV_INTERVAL;
    params.channel_map = 0; // all channels
    params.own_addr_type = BLE_OWN_ADDR_PUBLIC;
    params.primary_phy = BLE_HCI_LE_PHY_1M;
    params.secondary_phy = BLE_HCI_LE_PHY_1M;
    params.tx_power = 127; // controller picks its maximum
    params.sid = 0;

    int8_t selectedTxPower = 0;
    int rc = ble_gap_ext_adv_configure(BLE_MESH_ADV_INSTANCE, &params, &selectedTxPower, onGapEvent, this);
    if (rc != 0) {
        LOG_WARN("BLE mesh ext adv configure failed: %d", rc);
        return false;
    }

    // Left configured: only the data changes between frames, so reconfiguring per packet is a GAP
    // round trip for nothing.
    advInstanceConfigured = true;
    return true;
}
#endif

bool ESP32BLEMesh::platformBeginAdvertising(const uint8_t *adv, size_t len)
{
#if BLE_MESH_USE_EXT_ADV
    if (!configureAdvInstance())
        return false;

    struct os_mbuf *advData = os_msys_get_pkthdr(len, 0);
    if (!advData) {
        LOG_WARN("BLE mesh: failed to allocate mbuf");
        return false;
    }
    if (os_mbuf_append(advData, adv, len) != 0) {
        os_mbuf_free_chain(advData);
        return false;
    }

    // set_data takes ownership on success and frees on failure - do not touch advData after this.
    int rc = ble_gap_ext_adv_set_data(BLE_MESH_ADV_INSTANCE, advData);
    if (rc != 0) {
        LOG_WARN("BLE mesh ext adv set data failed: %d", rc);
        return false;
    }

    // Bounded by max_events, not by duration: duration is the middle argument and is in 10ms units,
    // not a repeat count.
    rc = ble_gap_ext_adv_start(BLE_MESH_ADV_INSTANCE, 0, BLE_MESH_ADV_EVENTS);
    if (rc != 0) {
        LOG_WARN("BLE mesh ext adv start failed: %d", rc);
        return false;
    }
    return true;
#else
    // Legacy advertising (BLE 4.2, 31 bytes total) cannot hold a mesh frame. This path exists to
    // keep the build uniform across ESP32 parts, not because classic ESP32 can join a BLE mesh.
    if (len > 31) {
        LOG_DEBUG("BLE mesh: %u bytes exceeds legacy advertising capacity, not sent", (unsigned)len);
        return false;
    }

    struct ble_gap_adv_params legacyParams = {};
    legacyParams.conn_mode = BLE_GAP_CONN_MODE_NON;
    legacyParams.disc_mode = BLE_GAP_DISC_MODE_GEN;
    legacyParams.itvl_min = BLE_MESH_ADV_INTERVAL;
    legacyParams.itvl_max = BLE_MESH_ADV_INTERVAL;
    legacyParams.channel_map = 0;

    if (ble_gap_adv_set_data(adv, len) != 0)
        return false;
    // The legacy API bounds a burst by milliseconds, not events, so convert the extended path's count.
    return ble_gap_adv_start(BLE_OWN_ADDR_PUBLIC, NULL, bleMeshBurstMs(BLE_MESH_ADV_EVENTS, BLE_MESH_ADV_INTERVAL), &legacyParams,
                             onGapEvent, this) == 0;
#endif
}

bool ESP32BLEMesh::platformAdvertisingActive()
{
#if BLE_MESH_USE_EXT_ADV
    return ble_gap_ext_adv_active(BLE_MESH_ADV_INSTANCE) != 0;
#else
    return ble_gap_adv_active() != 0;
#endif
}

void ESP32BLEMesh::platformEndAdvertising()
{
#if BLE_MESH_USE_EXT_ADV
    // Stop but do NOT remove: the instance stays configured for the next frame.
    ble_gap_ext_adv_stop(BLE_MESH_ADV_INSTANCE);
#else
    ble_gap_adv_stop();
#endif
}

void ESP32BLEMesh::startScanning()
{
    if (!platformReady())
        return;

#ifdef BLE_MESH_TX_ONLY
    LOG_INFO("BLE mesh: TX-only build, not scanning");
    return;
#endif

#if BLE_MESH_USE_EXT_ADV
    struct ble_gap_ext_disc_params uncodedParams = {};
    uncodedParams.itvl = BLE_MESH_SCAN_INTERVAL;
    uncodedParams.window = BLE_MESH_SCAN_WINDOW;
    uncodedParams.passive = 1; // never scan-request; the payload is all in the advertisement

    // filter_duplicates MUST stay 0: the controller de-duplicates on advertiser address, not on
    // payload, so every frame after a neighbour's first would be filtered away.
    int rc = ble_gap_ext_disc(BLE_OWN_ADDR_PUBLIC, 0 /* duration: forever */, 0 /* period */, 0 /* filter_duplicates */,
                              BLE_HCI_SCAN_FILT_NO_WL, 0 /* limited */, &uncodedParams, NULL, onGapEvent, this);
#else
    struct ble_gap_disc_params scanParams = {};
    scanParams.passive = 1;
    scanParams.itvl = BLE_MESH_SCAN_INTERVAL;
    scanParams.window = BLE_MESH_SCAN_WINDOW;
    scanParams.filter_duplicates = 0; // see above
    scanParams.limited = 0;
    scanParams.filter_policy = BLE_HCI_SCAN_FILT_NO_WL;

    int rc = ble_gap_disc(BLE_OWN_ADDR_PUBLIC, BLE_HS_FOREVER, &scanParams, onGapEvent, this);
#endif
    if (rc == 0) {
        LOG_DEBUG("BLE mesh scanning started");
    } else if (rc == BLE_HS_EALREADY) {
        LOG_DEBUG("BLE mesh scanning already active");
    } else {
        LOG_WARN("BLE mesh scan start failed: %d", rc);
    }
}

void ESP32BLEMesh::stopScanning()
{
    if (!platformReady())
        return;

    ble_gap_disc_cancel();
}

int ESP32BLEMesh::onGapEvent(struct ble_gap_event *event, void *arg)
{
    auto *self = static_cast<ESP32BLEMesh *>(arg);
    if (!self)
        return 0;

    switch (event->type) {
    case BLE_GAP_EVENT_DISC:
        self->handleAdvertisement(&event->disc);
        break;
#if BLE_MESH_USE_EXT_ADV
    case BLE_GAP_EVENT_EXT_DISC:
        self->handleExtendedAdvertisement(&event->ext_disc);
        break;
#endif
    case BLE_GAP_EVENT_DISC_COMPLETE:
        if (self->isRunning) {
            self->startScanning();
        }
        break;
    default:
        break;
    }

    return 0;
}

void ESP32BLEMesh::handleAdvertisement(const struct ble_gap_disc_desc *desc)
{
    if (!isRunning || !desc)
        return;

    handleAdvertisementData(desc->data, desc->length_data, desc->rssi);
}

#if BLE_MESH_USE_EXT_ADV
void ESP32BLEMesh::handleExtendedAdvertisement(const struct ble_gap_ext_disc_desc *desc)
{
    if (!isRunning || !desc)
        return;

    ScanReportStatus status = ScanReportStatus::Truncated;
    if (desc->data_status == BLE_GAP_EXT_ADV_DATA_STATUS_COMPLETE)
        status = ScanReportStatus::Complete;
    else if (desc->data_status == BLE_GAP_EXT_ADV_DATA_STATUS_INCOMPLETE)
        status = ScanReportStatus::Incomplete;

    onScanReport(desc->addr.type, desc->addr.val, desc->sid, status, desc->data, desc->length_data, desc->rssi);
}
#endif

#endif // HAS_BLE_MESH && ARCH_ESP32