circuitpython/devices/ble_hci/common-hal/_bleio/Connection.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Dan Halbert for Adafruit Industries
 * Copyright (c) 2018 Artur Pacholec
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "shared-bindings/_bleio/Connection.h"

#include "att.h"

#include <string.h>
#include <stdio.h>

#include "shared/runtime/interrupt_char.h"
#include "py/gc.h"
#include "py/objlist.h"
#include "py/objstr.h"
#include "py/qstr.h"
#include "py/runtime.h"
#include "shared-bindings/_bleio/__init__.h"
#include "shared-bindings/_bleio/Adapter.h"
#include "shared-bindings/_bleio/Attribute.h"
#include "shared-bindings/_bleio/Characteristic.h"
#include "shared-bindings/_bleio/Service.h"
#include "shared-bindings/_bleio/UUID.h"
#include "supervisor/shared/tick.h"

#define BLE_ADV_LENGTH_FIELD_SIZE   1
#define BLE_ADV_AD_TYPE_FIELD_SIZE  1
#define BLE_AD_TYPE_FLAGS_DATA_SIZE 1

// static const ble_gap_sec_params_t pairing_sec_params = {
//     .bond = 1,
//     .mitm = 0,
//     .lesc = 0,
//     .keypress = 0,
//     .oob = 0,
//     .io_caps = BLE_GAP_IO_CAPS_NONE,
//     .min_key_size = 7,
//     .max_key_size = 16,
//     .kdist_own    = { .enc = 1, .id = 1},
//     .kdist_peer   = { .enc = 1, .id = 1},
// };

#define CONNECTION_DEBUG (1)
#if CONNECTION_DEBUG
  #define CONNECTION_DEBUG_PRINTF(...) printf(__VA_ARGS__)
#else
  #define CONNECTION_DEBUG_PRINTF(...)
#endif

static volatile bool m_discovery_in_process;
static volatile bool m_discovery_successful;

// FIX static bleio_service_obj_t *m_char_discovery_service;
// FIX static bleio_characteristic_obj_t *m_desc_discovery_characteristic;

// bool connection_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
//     bleio_connection_internal_t *self = (bleio_connection_internal_t*)self_in;

//     if (BLE_GAP_EVT_BASE <= ble_evt->header.evt_id && ble_evt->header.evt_id <= BLE_GAP_EVT_LAST &&
//         ble_evt->evt.gap_evt.conn_handle != self->conn_handle) {
//         return false;
//     }
//     if (BLE_GATTS_EVT_BASE <= ble_evt->header.evt_id && ble_evt->header.evt_id <= BLE_GATTS_EVT_LAST &&
//         ble_evt->evt.gatts_evt.conn_handle != self->conn_handle) {
//         return false;
//     }

//     switch (ble_evt->header.evt_id) {
//         case BLE_GAP_EVT_DISCONNECTED:
//             // Adapter.c does the work for this event.
//             break;

//         case BLE_GAP_EVT_PHY_UPDATE_REQUEST: {
//             ble_gap_phys_t const phys = {
//                 .rx_phys = BLE_GAP_PHY_AUTO,
//                 .tx_phys = BLE_GAP_PHY_AUTO,
//             };
//             sd_ble_gap_phy_update(ble_evt->evt.gap_evt.conn_handle, &phys);
//             break;
//         }

//         case BLE_GAP_EVT_PHY_UPDATE: { // 0x22
//             break;
//         }

//         case BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST:
//             // SoftDevice will respond to a length update request.
//             sd_ble_gap_data_length_update(self->conn_handle, NULL, NULL);
//             break;

//         case BLE_GAP_EVT_DATA_LENGTH_UPDATE: { // 0x24
//             break;
//         }

//         case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST: {
//             ble_gatts_evt_exchange_mtu_request_t *request =
//                     &ble_evt->evt.gatts_evt.params.exchange_mtu_request;

//             uint16_t new_mtu = BLE_GATTS_VAR_ATTR_LEN_MAX;
//             if (request->client_rx_mtu < new_mtu) {
//                 new_mtu = request->client_rx_mtu;
//             }
//             if (new_mtu < BLE_GATT_ATT_MTU_DEFAULT) {
//                 new_mtu = BLE_GATT_ATT_MTU_DEFAULT;
//             }
//             if (self->mtu > 0) {
//                 new_mtu = self->mtu;
//             }

//             self->mtu = new_mtu;
//             sd_ble_gatts_exchange_mtu_reply(self->conn_handle, new_mtu);
//             break;
//         }


//         case BLE_GATTC_EVT_EXCHANGE_MTU_RSP: {
//             ble_gattc_evt_exchange_mtu_rsp_t *response =
//                     &ble_evt->evt.gattc_evt.params.exchange_mtu_rsp;

//             self->mtu = response->server_rx_mtu;
//             break;
//         }

//         case BLE_GATTS_EVT_WRITE:
//             // A client wrote a value.
//             // If we are bonded and it's a CCCD (UUID 0x2902), store the CCCD value.
//             if (self->conn_handle != BLE_CONN_HANDLE_INVALID &&
//                 self->pair_status == PAIR_PAIRED &&
//                 ble_evt->evt.gatts_evt.params.write.uuid.type == BLE_UUID_TYPE_BLE &&
//                 ble_evt->evt.gatts_evt.params.write.uuid.uuid == 0x2902) {
//                 //
//                 // Save sys_attr data (CCCD state) in bonding area at
//                 // next opportunity, but also remember time of this
//                 // request, so we can consolidate closely-spaced requests.
//                 self->do_bond_cccds = true;
//                 self->do_bond_cccds_request_time = supervisor_ticks_ms64();
//             }
//             // Return false so other handlers get this event as well.
//             return false;

//         case BLE_GATTS_EVT_SYS_ATTR_MISSING:
//             sd_ble_gatts_sys_attr_set(self->conn_handle, NULL, 0, 0);
//             break;

//         #if CIRCUITPY_VERBOSE_BLE
//         // Use read authorization to snoop on all reads when doing verbose debugging.
//         case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST: {

//             ble_gatts_evt_rw_authorize_request_t *request =
//                     &ble_evt->evt.gatts_evt.params.authorize_request;

//             mp_printf(&mp_plat_print, "Read %x offset %d ", request->request.read.handle, request->request.read.offset);
//             uint8_t value_bytes[22];
//             ble_gatts_value_t value;
//             value.offset = request->request.read.offset;
//             value.len = 22;
//             value.p_value = value_bytes;

//             sd_ble_gatts_value_get(self->conn_handle, request->request.read.handle, &value);
//             size_t len = value.len;
//             if (len > 22) {
//                 len = 22;
//             }
//             for (uint8_t i = 0; i < len; i++) {
//                 mp_printf(&mp_plat_print, " %02x", value_bytes[i]);
//             }
//             mp_printf(&mp_plat_print, "\n");
//             ble_gatts_rw_authorize_reply_params_t reply;
//             reply.type = request->type;
//             reply.params.read.gatt_status = BLE_GATT_STATUS_SUCCESS;
//             reply.params.read.update = false;
//             reply.params.read.offset = request->request.read.offset;
//             sd_ble_gatts_rw_authorize_reply(self->conn_handle, &reply);
//             break;
//         }
//         #endif

//         case BLE_GATTS_EVT_HVN_TX_COMPLETE: // Capture this for now. 0x55
//             break;
//         case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST: {
//             self->conn_params_updating = true;
//             ble_gap_evt_conn_param_update_request_t *request =
//                     &ble_evt->evt.gap_evt.params.conn_param_update_request;
//             sd_ble_gap_conn_param_update(self->conn_handle, &request->conn_params);
//             break;
//         }
//         case BLE_GAP_EVT_CONN_PARAM_UPDATE: { // 0x12
//             ble_gap_evt_conn_param_update_t *result =
//                     &ble_evt->evt.gap_evt.params.conn_param_update;

//             #if CIRCUITPY_VERBOSE_BLE
//             ble_gap_conn_params_t *cp = &ble_evt->evt.gap_evt.params.conn_param_update.conn_params;
//             mp_printf(&mp_plat_print, "conn params updated: min_ci %d max_ci %d s_l %d sup_timeout %d\n", cp->min_conn_interval, cp->max_conn_interval, cp->slave_latency, cp->conn_sup_timeout);
//             #endif

//             memcpy(&self->conn_params, &result->conn_params, sizeof(ble_gap_conn_params_t));
//             self->conn_params_updating = false;
//             break;
//         }
//         case BLE_GAP_EVT_SEC_PARAMS_REQUEST: {
//             // First time pairing.
//             // 1. Either we or peer initiate the process
//             // 2. Peer asks for security parameters using BLE_GAP_EVT_SEC_PARAMS_REQUEST.
//             // 3. Pair Key exchange ("just works" implemented now; TODO: out-of-band key pairing)
//             // 4. Connection is secured: BLE_GAP_EVT_CONN_SEC_UPDATE
//             // 5. Long-term Keys exchanged: BLE_GAP_EVT_AUTH_STATUS

//             bonding_clear_keys(&self->bonding_keys);
//             self->ediv = EDIV_INVALID;
//             ble_gap_sec_keyset_t keyset = {
//                 .keys_own = {
//                     .p_enc_key  = &self->bonding_keys.own_enc,
//                     .p_id_key   = NULL,
//                     .p_sign_key = NULL,
//                     .p_pk       = NULL
//                 },

//                 .keys_peer = {
//                     .p_enc_key  = &self->bonding_keys.peer_enc,
//                     .p_id_key   = &self->bonding_keys.peer_id,
//                     .p_sign_key = NULL,
//                     .p_pk       = NULL
//                 }
//             };

//             sd_ble_gap_sec_params_reply(self->conn_handle, BLE_GAP_SEC_STATUS_SUCCESS,
//                                         self->is_central ? NULL : &pairing_sec_params,
//                                         &keyset);
//             break;
//         }

//         case BLE_GAP_EVT_LESC_DHKEY_REQUEST:
//             // TODO for LESC pairing:
//             // sd_ble_gap_lesc_dhkey_reply(...);
//             break;

//         case BLE_GAP_EVT_AUTH_STATUS: { // 0x19
//             // Key exchange completed.
//             ble_gap_evt_auth_status_t* status = &ble_evt->evt.gap_evt.params.auth_status;
//             self->sec_status = status->auth_status;
//             if (status->auth_status == BLE_GAP_SEC_STATUS_SUCCESS) {
//                 self->ediv = self->bonding_keys.own_enc.master_id.ediv;
//                 self->pair_status = PAIR_PAIRED;
//                 // Save keys in bonding area at next opportunity.
//                 self->do_bond_keys = true;
//             } else {
//                 // Inform busy-waiter pairing has failed.
//                 self->pair_status = PAIR_NOT_PAIRED;
//             }
//             break;
//         }

//         case BLE_GAP_EVT_SEC_INFO_REQUEST: { // 0x14
//             // Peer asks for the stored keys.
//             // - load key and return if bonded previously.
//             // - Else return NULL --> Initiate key exchange
//             ble_gap_evt_sec_info_request_t* sec_info_request = &ble_evt->evt.gap_evt.params.sec_info_request;
//             (void) sec_info_request;
//             if ( bonding_load_keys(self->is_central, sec_info_request->master_id.ediv, &self->bonding_keys) ) {
//                 sd_ble_gap_sec_info_reply(
//                     self->conn_handle,
//                     &self->bonding_keys.own_enc.enc_info,
//                     &self->bonding_keys.peer_id.id_info,
//                     NULL);
//                 self->ediv = self->bonding_keys.own_enc.master_id.ediv;
//             } else {
//                 // We don't have stored keys. Ask for keys.
//                 sd_ble_gap_sec_info_reply(self->conn_handle, NULL, NULL, NULL);
//             }
//             break;
//         }

//         case BLE_GAP_EVT_CONN_SEC_UPDATE: { // 0x1a
//             // We get this both on first-time pairing and on subsequent pairings using stored keys.
//             ble_gap_conn_sec_t* conn_sec = &ble_evt->evt.gap_evt.params.conn_sec_update.conn_sec;
//             if (conn_sec->sec_mode.sm <= 1 && conn_sec->sec_mode.lv <= 1) {
//                 // Security setup did not succeed:
//                 // mode 0, level 0 means no access
//                 // mode 1, level 1 means open link
//                 // mode >=1 and/or level >=1 means encryption is set up
//                 self->pair_status = PAIR_NOT_PAIRED;
//             } else {
//                 if (bonding_load_cccd_info(self->is_central, self->conn_handle, self->ediv)) {
//                     // Did an sd_ble_gatts_sys_attr_set() with the stored sys_attr values.
//                 } else {
//                     // No matching bonding found, so use fresh system attributes.
//                     sd_ble_gatts_sys_attr_set(self->conn_handle, NULL, 0, 0);
//                 }
//                 self->pair_status = PAIR_PAIRED;
//             }
//             break;
//         }

//         default:
//             return false;
//     }
//     return true;
// }

void bleio_connection_clear(bleio_connection_internal_t *self) {
    mp_obj_list_clear(MP_OBJ_FROM_PTR(self->remote_service_list));

    self->conn_handle = BLE_CONN_HANDLE_INVALID;
    self->pair_status = PAIR_NOT_PAIRED;
    self->is_central = false;
    // FIX bonding_clear_keys(&self->bonding_keys);
}

bool common_hal_bleio_connection_get_paired(bleio_connection_obj_t *self) {
    if (self->connection == NULL) {
        return false;
    }
    return self->connection->pair_status == PAIR_PAIRED;
}

bool common_hal_bleio_connection_get_connected(bleio_connection_obj_t *self) {
    if (self->connection == NULL) {
        return false;
    }
    return self->connection->conn_handle != BLE_CONN_HANDLE_INVALID;
}

void common_hal_bleio_connection_disconnect(bleio_connection_internal_t *self) {
    hci_disconnect(self->conn_handle);
}

void common_hal_bleio_connection_pair(bleio_connection_internal_t *self, bool bond) {
    self->pair_status = PAIR_WAITING;

    // FIX check_nrf_error(sd_ble_gap_authenticate(self->conn_handle, &pairing_sec_params));

    while (self->pair_status == PAIR_WAITING && !mp_hal_is_interrupted()) {
        RUN_BACKGROUND_TASKS;
    }
    if (mp_hal_is_interrupted()) {
        return;
    }
    // FIX    check_sec_status(self->sec_status);
}

mp_float_t common_hal_bleio_connection_get_connection_interval(bleio_connection_internal_t *self) {
    while (self->conn_params_updating && !mp_hal_is_interrupted()) {
        RUN_BACKGROUND_TASKS;
    }
    // FIX return 1.25f * self->conn_params.min_conn_interval;
    return 0.0f;
}

// Return the current negotiated MTU length, minus overhead.
mp_int_t common_hal_bleio_connection_get_max_packet_length(bleio_connection_internal_t *self) {
    return (self->mtu == 0 ? BT_ATT_DEFAULT_LE_MTU : self->mtu) - 3;
}

void common_hal_bleio_connection_set_connection_interval(bleio_connection_internal_t *self, mp_float_t new_interval) {
    // self->conn_params_updating = true;
    // uint16_t interval = new_interval / 1.25f;
    // self->conn_params.min_conn_interval = interval;
    // self->conn_params.max_conn_interval = interval;
    // uint32_t status = NRF_ERROR_BUSY;
    // while (status == NRF_ERROR_BUSY) {
    //     status = sd_ble_gap_conn_param_update(self->conn_handle, &self->conn_params);
    //     RUN_BACKGROUND_TASKS;
    // }
    // check_nrf_error(status);
}

// service_uuid may be NULL, to discover all services.
// STATIC bool discover_next_services(bleio_connection_internal_t* connection, uint16_t start_handle, ble_uuid_t *service_uuid) {
//     m_discovery_successful = false;
//     m_discovery_in_process = true;

//     uint32_t nrf_err = NRF_ERROR_BUSY;
//     while (nrf_err == NRF_ERROR_BUSY) {
//         nrf_err = sd_ble_gattc_primary_services_discover(connection->conn_handle, start_handle, service_uuid);
//     }
//     check_nrf_error(nrf_err);

//     // Wait for a discovery event.
//     while (m_discovery_in_process) {
//         MICROPY_VM_HOOK_LOOP;
//     }
//     return m_discovery_successful;
// }

// STATIC bool discover_next_characteristics(bleio_connection_internal_t* connection, bleio_service_obj_t *service, uint16_t start_handle) {
//     m_char_discovery_service = service;

//     ble_gattc_handle_range_t handle_range;
//     handle_range.start_handle = start_handle;
//     handle_range.end_handle = service->end_handle;

//     m_discovery_successful = false;
//     m_discovery_in_process = true;

//     uint32_t err_code = sd_ble_gattc_characteristics_discover(connection->conn_handle, &handle_range);
//     if (err_code != NRF_SUCCESS) {
//         return false;
//     }

//     // Wait for a discovery event.
//     while (m_discovery_in_process) {
//         MICROPY_VM_HOOK_LOOP;
//     }
//     return m_discovery_successful;
// }

// STATIC bool discover_next_descriptors(bleio_connection_internal_t* connection, bleio_characteristic_obj_t *characteristic, uint16_t start_handle, uint16_t end_handle) {
//     m_desc_discovery_characteristic = characteristic;

//     ble_gattc_handle_range_t handle_range;
//     handle_range.start_handle = start_handle;
//     handle_range.end_handle = end_handle;

//     m_discovery_successful = false;
//     m_discovery_in_process = true;

//     uint32_t err_code = sd_ble_gattc_descriptors_discover(connection->conn_handle, &handle_range);
//     if (err_code != NRF_SUCCESS) {
//         return false;
//     }

//     // Wait for a discovery event.
//     while (m_discovery_in_process) {
//         MICROPY_VM_HOOK_LOOP;
//     }
//     return m_discovery_successful;
// }

// STATIC void on_primary_srv_discovery_rsp(ble_gattc_evt_prim_srvc_disc_rsp_t *response, bleio_connection_internal_t* connection) {
//     for (size_t i = 0; i < response->count; ++i) {
//         ble_gattc_service_t *gattc_service = &response->services[i];

//         bleio_service_obj_t *service = mp_obj_malloc(bleio_service_obj_t, &bleio_service_type);

//         // Initialize several fields at once.
//         bleio_service_from_connection(service, bleio_connection_new_from_internal(connection));

//         service->is_remote = true;
//         service->start_handle = gattc_service->handle_range.start_handle;
//         service->end_handle = gattc_service->handle_range.end_handle;
//         service->handle = gattc_service->handle_range.start_handle;

//         if (gattc_service->uuid.type != BLE_UUID_TYPE_UNKNOWN) {
//             // Known service UUID.
//             bleio_uuid_obj_t *uuid = mp_obj_malloc(bleio_uuid_obj_t, &bleio_uuid_type);
//             bleio_uuid_construct_from_nrf_ble_uuid(uuid, &gattc_service->uuid);
//             service->uuid = uuid;
//         } else {
//             // The discovery response contained a 128-bit UUID that has not yet been registered with the
//             // softdevice via sd_ble_uuid_vs_add(). We need to fetch the 128-bit value and register it.
//             // For now, just set the UUID to NULL.
//             service->uuid = NULL;
//         }
//
//         mp_obj_list_append(MP_OBJ_FROM_PTR(connection->remote_service_list),
//                            MP_OBJ_FROM_PTR(service));
//     }
//
//     if (response->count > 0) {
//         m_discovery_successful = true;
//     }
//     m_discovery_in_process = false;
// }

// STATIC void on_char_discovery_rsp(ble_gattc_evt_char_disc_rsp_t *response, bleio_connection_internal_t* connection) {
//     for (size_t i = 0; i < response->count; ++i) {
//         ble_gattc_char_t *gattc_char = &response->chars[i];

//         bleio_characteristic_obj_t *characteristic =
//             mp_obj_malloc(bleio_characteristic_obj_t, &bleio_characteristic_type);

//         bleio_uuid_obj_t *uuid = NULL;

//         if (gattc_char->uuid.type != BLE_UUID_TYPE_UNKNOWN) {
//             // Known characteristic UUID.
//             uuid = mp_obj_malloc(bleio_uuid_obj_t, &bleio_uuid_type);
//             bleio_uuid_construct_from_nrf_ble_uuid(uuid, &gattc_char->uuid);
//         } else {
//             // The discovery response contained a 128-bit UUID that has not yet been registered with the
//             // softdevice via sd_ble_uuid_vs_add(). We need to fetch the 128-bit value and register it.
//             // For now, just leave the UUID as NULL.
//         }

//         bleio_characteristic_properties_t props =
//             (gattc_char->char_props.broadcast ? CHAR_PROP_BROADCAST : 0) |
//             (gattc_char->char_props.indicate ? CHAR_PROP_INDICATE : 0) |
//             (gattc_char->char_props.notify ? CHAR_PROP_NOTIFY : 0) |
//             (gattc_char->char_props.read ? CHAR_PROP_READ : 0) |
//             (gattc_char->char_props.write ? CHAR_PROP_WRITE : 0) |
//             (gattc_char->char_props.write_wo_resp ? CHAR_PROP_WRITE_NO_RESPONSE : 0);

//         // Call common_hal_bleio_characteristic_construct() to initialize some fields and set up evt handler.
//         common_hal_bleio_characteristic_construct(
//             characteristic, m_char_discovery_service, gattc_char->handle_value, uuid,
//             props, SECURITY_MODE_OPEN, SECURITY_MODE_OPEN,
//             GATT_MAX_DATA_LENGTH, false,   // max_length, fixed_length: values may not matter for gattc
//             NULL);

//         mp_obj_list_append(MP_OBJ_FROM_PTR(m_char_discovery_service->characteristic_list),
//                            MP_OBJ_FROM_PTR(characteristic));
//     }

//     if (response->count > 0) {
//         m_discovery_successful = true;
//     }
//     m_discovery_in_process = false;
// }

// STATIC void on_desc_discovery_rsp(ble_gattc_evt_desc_disc_rsp_t *response, bleio_connection_internal_t* connection) {
//     for (size_t i = 0; i < response->count; ++i) {
//         ble_gattc_desc_t *gattc_desc = &response->descs[i];

//         // Remember handles for certain well-known descriptors.
//         switch (gattc_desc->uuid.uuid) {
//             case BLE_UUID_DESCRIPTOR_CLIENT_CHAR_CONFIG:
//                 m_desc_discovery_characteristic->cccd_handle = gattc_desc->handle;
//                 break;

//             case BLE_UUID_DESCRIPTOR_SERVER_CHAR_CONFIG:
//                 m_desc_discovery_characteristic->sccd_handle = gattc_desc->handle;
//                 break;

//             case BLE_UUID_DESCRIPTOR_CHAR_USER_DESC:
//                 m_desc_discovery_characteristic->user_desc_handle = gattc_desc->handle;
//                 break;

//             default:
//                 // TODO: sd_ble_gattc_descriptors_discover() can return things that are not descriptors,
//                 // so ignore those.
//                 // https://devzone.nordicsemi.com/f/nordic-q-a/49500/sd_ble_gattc_descriptors_discover-is-returning-attributes-that-are-not-descriptors
//                 break;
//         }

//         bleio_descriptor_obj_t *descriptor = mp_obj_malloc(bleio_descriptor_obj_t, &bleio_descriptor_type);

//         bleio_uuid_obj_t *uuid = NULL;

//         if (gattc_desc->uuid.type != BLE_UUID_TYPE_UNKNOWN) {
//             // Known descriptor UUID.
//             uuid = mp_obj_malloc(bleio_uuid_obj_t, &bleio_uuid_type);
//             bleio_uuid_construct_from_nrf_ble_uuid(uuid, &gattc_desc->uuid);
//         } else {
//             // The discovery response contained a 128-bit UUID that has not yet been registered with the
//             // softdevice via sd_ble_uuid_vs_add(). We need to fetch the 128-bit value and register it.
//             // For now, just leave the UUID as NULL.
//         }

//         common_hal_bleio_descriptor_construct(
//             descriptor, m_desc_discovery_characteristic, uuid,
//             SECURITY_MODE_OPEN, SECURITY_MODE_OPEN,
//             GATT_MAX_DATA_LENGTH, false, mp_const_empty_bytes);
//         descriptor->handle = gattc_desc->handle;

//         mp_obj_list_append(MP_OBJ_FROM_PTR(m_desc_discovery_characteristic->descriptor_list),
//                            MP_OBJ_FROM_PTR(descriptor));
//     }

//     if (response->count > 0) {
//         m_discovery_successful = true;
//     }
//     m_discovery_in_process = false;
// }

// STATIC bool discovery_on_ble_evt(ble_evt_t *ble_evt, mp_obj_t payload) {
//     bleio_connection_internal_t* connection = MP_OBJ_TO_PTR(payload);
//     switch (ble_evt->header.evt_id) {
//         case BLE_GAP_EVT_DISCONNECTED:
//             m_discovery_successful = false;
//             m_discovery_in_process = false;
//             break;

//         case BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP:
//             on_primary_srv_discovery_rsp(&ble_evt->evt.gattc_evt.params.prim_srvc_disc_rsp, connection);
//             break;

//         case BLE_GATTC_EVT_CHAR_DISC_RSP:
//             on_char_discovery_rsp(&ble_evt->evt.gattc_evt.params.char_disc_rsp, connection);
//             break;

//         case BLE_GATTC_EVT_DESC_DISC_RSP:
//             on_desc_discovery_rsp(&ble_evt->evt.gattc_evt.params.desc_disc_rsp, connection);
//             break;

//         default:
//             // CONNECTION_DEBUG_PRINTF(&mp_plat_print, "Unhandled discovery event: 0x%04x\n", ble_evt->header.evt_id);
//             return false;
//             break;
//     }
//     return true;
// }

// STATIC void discover_remote_services(bleio_connection_internal_t *self, mp_obj_t service_uuids_whitelist) {
//     ble_drv_add_event_handler(discovery_on_ble_evt, self);

//     // Start over with an empty list.
//     self->remote_service_list = mp_obj_new_list(0, NULL);


//     if (service_uuids_whitelist == mp_const_none) {
//         // List of service UUID's not given, so discover all available services.

//         uint16_t next_service_start_handle = BLE_GATT_HANDLE_START;

//         while (discover_next_services(self, next_service_start_handle, MP_OBJ_NULL)) {
//             // discover_next_services() appends to remote_services_list.

//             // Get the most recently discovered service, and then ask for services
//             // whose handles start after the last attribute handle inside that service.
//             // There must be at least one if discover_next_services() returned true.
//             const bleio_service_obj_t *service =
//                 self->remote_service_list->items[self->remote_service_list->len - 1];
//             next_service_start_handle = service->end_handle + 1;
//         }
//     } else {
//         mp_obj_iter_buf_t iter_buf;
//         mp_obj_t iterable = mp_getiter(service_uuids_whitelist, &iter_buf);
//         mp_obj_t uuid_obj;
//         while ((uuid_obj = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
//             if (!mp_obj_is_type(uuid_obj, &bleio_uuid_type)) {
//                 mp_raise_TypeError(MP_ERROR_TEXT("non-UUID found in service_uuids_whitelist"));
//             }
//             bleio_uuid_obj_t *uuid = MP_OBJ_TO_PTR(uuid_obj);

//             ble_uuid_t nrf_uuid;
//             bleio_uuid_convert_to_nrf_ble_uuid(uuid, &nrf_uuid);

//             // Service might or might not be discovered; that's ok. Caller has to check
//             // Central.remote_services to find out.
//             // We only need to call this once for each service to discover.
//             discover_next_services(self, BLE_GATT_HANDLE_START, &nrf_uuid);
//         }
//     }


//     for (size_t i = 0; i < self->remote_service_list->len; i++) {
//         bleio_service_obj_t *service = MP_OBJ_TO_PTR(self->remote_service_list->items[i]);
//         // Skip the service if it had an unknown (unregistered) UUID.
//         if (service->uuid == NULL) {
//             continue;
//         }

//         uint16_t next_char_start_handle = service->start_handle;

//         // Stop when we go past the end of the range of handles for this service or
//         // discovery call returns nothing.
//         // discover_next_characteristics() appends to the characteristic_list.
//         while (next_char_start_handle <= service->end_handle &&
//                discover_next_characteristics(self, service, next_char_start_handle)) {


//             // Get the most recently discovered characteristic, and then ask for characteristics
//             // whose handles start after the last attribute handle inside that characteristic.
//             const bleio_characteristic_obj_t *characteristic =
//                 MP_OBJ_TO_PTR(service->characteristic_list->items[service->characteristic_list->len - 1]);

//             next_char_start_handle = characteristic->handle + 1;
//         }

//         // Got characteristics for this service. Now discover descriptors for each characteristic.
//         size_t char_list_len = service->characteristic_list->len;
//         for (size_t char_idx = 0; char_idx < char_list_len; ++char_idx) {
//             bleio_characteristic_obj_t *characteristic =
//                 MP_OBJ_TO_PTR(service->characteristic_list->items[char_idx]);
//             const bool last_characteristic = char_idx == char_list_len - 1;
//             bleio_characteristic_obj_t *next_characteristic = last_characteristic
//                 ? NULL
//                 : MP_OBJ_TO_PTR(service->characteristic_list->items[char_idx + 1]);

//             // Skip the characteristic if it had an unknown (unregistered) UUID.
//             if (characteristic->uuid == NULL) {
//                 continue;
//             }

//             uint16_t next_desc_start_handle = characteristic->handle + 1;

//             // Don't run past the end of this service or the beginning of the next characteristic.
//             uint16_t next_desc_end_handle = next_characteristic == NULL
//                 ? service->end_handle
//                 : next_characteristic->handle - 1;

//             // Stop when we go past the end of the range of handles for this service or
//             // discovery call returns nothing.
//             // discover_next_descriptors() appends to the descriptor_linked_list.
//             while (next_desc_start_handle <= service->end_handle &&
//                    next_desc_start_handle <= next_desc_end_handle &&
//                    discover_next_descriptors(self, characteristic,
//                                              next_desc_start_handle, next_desc_end_handle)) {
//                 // Get the most recently discovered descriptor, and then ask for descriptors
//                 // whose handles start after that descriptor's handle.
//                 // There must be at least one if discover_next_descriptors() returned true.
//                 const bleio_descriptor_obj_t *descriptor =
//                     characteristic->descriptor_list->items[characteristic->descriptor_list->len - 1];
//                 next_desc_start_handle = descriptor->handle + 1;
//             }
//         }
//     }

//     // This event handler is no longer needed.
//     ble_drv_remove_event_handler(discovery_on_ble_evt, self);

// }

mp_obj_tuple_t *common_hal_bleio_connection_discover_remote_services(bleio_connection_obj_t *self, mp_obj_t service_uuids_whitelist) {
    // FIX discover_remote_services(self->connection, service_uuids_whitelist);
    bleio_connection_ensure_connected(self);
    // Convert to a tuple and then clear the list so the callee will take ownership.
    mp_obj_tuple_t *services_tuple =
        mp_obj_new_tuple(self->connection->remote_service_list->len,
            self->connection->remote_service_list->items);
    mp_obj_list_clear(MP_OBJ_FROM_PTR(self->connection->remote_service_list));
    return services_tuple;
}

uint16_t bleio_connection_get_conn_handle(bleio_connection_obj_t *self) {
    if (self == NULL || self->connection == NULL) {
        return BLE_CONN_HANDLE_INVALID;
    }
    return self->connection->conn_handle;
}

mp_obj_t bleio_connection_new_from_internal(bleio_connection_internal_t *internal) {
    if (internal->connection_obj != mp_const_none) {
        return internal->connection_obj;
    }
    bleio_connection_obj_t *connection = mp_obj_malloc(bleio_connection_obj_t, &bleio_connection_type);
    connection->connection = internal;
    internal->connection_obj = connection;

    return MP_OBJ_FROM_PTR(connection);
}

// Find the connection that uses the given conn_handle. Return NULL if not found.
bleio_connection_internal_t *bleio_conn_handle_to_connection(uint16_t conn_handle) {
    bleio_connection_internal_t *connection;
    for (size_t i = 0; i < BLEIO_TOTAL_CONNECTION_COUNT; i++) {
        connection = &bleio_connections[i];
        if (connection->conn_handle == conn_handle) {
            return connection;
        }
    }

    return NULL;
}