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

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2019 Dan Halbert for Adafruit Industries
 * Copyright (c) 2018 Artur Pacholec
 * Copyright (c) 2016 Glenn Ruben Bakke
 *
 * 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 "py/runtime.h"

#include "shared-bindings/_bleio/__init__.h"
#include "shared-bindings/_bleio/Descriptor.h"
#include "shared-bindings/_bleio/Service.h"
#include "shared-bindings/_bleio/UUID.h"

void common_hal_bleio_descriptor_construct(bleio_descriptor_obj_t *self, bleio_characteristic_obj_t *characteristic, bleio_uuid_obj_t *uuid, bleio_attribute_security_mode_t read_perm, bleio_attribute_security_mode_t write_perm, mp_int_t max_length, bool fixed_length, mp_buffer_info_t *initial_value_bufinfo) {
    self->characteristic = characteristic;
    self->uuid = uuid;
    self->handle = BLE_GATT_HANDLE_INVALID;
    self->read_perm = read_perm;
    self->write_perm = write_perm;
    self->value = mp_obj_new_bytes(initial_value_bufinfo->buf, initial_value_bufinfo->len);

    const mp_int_t max_length_max = fixed_length ? BLE_GATTS_FIX_ATTR_LEN_MAX : BLE_GATTS_VAR_ATTR_LEN_MAX;
    if (max_length < 0 || max_length > max_length_max) {
        mp_raise_ValueError_varg(translate("max_length must be 0-%d when fixed_length is %s"),
                                 max_length_max, fixed_length ? "True" : "False");
    }
    self->max_length = max_length;
    self->fixed_length = fixed_length;

    common_hal_bleio_descriptor_set_value(self, initial_value_bufinfo);
}

bleio_uuid_obj_t *common_hal_bleio_descriptor_get_uuid(bleio_descriptor_obj_t *self) {
    return self->uuid;
}

bleio_characteristic_obj_t *common_hal_bleio_descriptor_get_characteristic(bleio_descriptor_obj_t *self) {
    return self->characteristic;
}

size_t common_hal_bleio_descriptor_get_value(bleio_descriptor_obj_t *self, uint8_t* buf, size_t len) {
    // Do GATT operations only if this descriptor has been registered
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        if (common_hal_bleio_service_get_is_remote(self->characteristic->service)) {
            //uint16_t conn_handle = bleio_connection_get_conn_handle(self->characteristic->service->connection);
            //FIX have att_read_req fill in a buffer
            //uint8_t rsp[MAX(len, 512)];
            //return att_read_req(conn_handle, self->handle, rsp, len);
            return 0;
        } else {
            mp_buffer_info_t bufinfo;
            if (!mp_get_buffer(self->value, &bufinfo, MP_BUFFER_READ)) {
                return 0;
            }
            size_t actual_length = MIN(len, bufinfo.len);
            memcpy(buf, bufinfo.buf, actual_length);
            return actual_length;
        }
    }

    return 0;
}

void common_hal_bleio_descriptor_set_value(bleio_descriptor_obj_t *self, mp_buffer_info_t *bufinfo) {
    if (self->fixed_length && bufinfo->len != self->max_length) {
        mp_raise_ValueError(translate("Value length != required fixed length"));
    }
    if (bufinfo->len > self->max_length) {
        mp_raise_ValueError(translate("Value length > max_length"));
    }

    self->value = mp_obj_new_bytes(bufinfo->buf, bufinfo->len);

    // Do GATT operations only if this descriptor has been registered.
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        if (common_hal_bleio_service_get_is_remote(self->characteristic->service)) {
            //FIX
            // uint16_t conn_handle = bleio_connection_get_conn_handle(self->service->connection);
            // att_write_req(conn_handle, self->handle, bufinfo->buf, bufinfo->len, rsp);
        } else {
            // Always write the value locally even if no connections are active.
            if (self->fixed_length && bufinfo->len != self->max_length) {
                return;
            }
            if (bufinfo->len > self->max_length) {
                return;
            }

            self->value = mp_obj_new_bytes(bufinfo->buf, bufinfo->len);
        }
    }
}