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

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 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 "py/runtime.h"

#include "shared-bindings/_bleio/__init__.h"
#include "shared-bindings/_bleio/Characteristic.h"
#include "shared-bindings/_bleio/CharacteristicBuffer.h"
#include "shared-bindings/_bleio/Descriptor.h"
#include "shared-bindings/_bleio/PacketBuffer.h"
#include "shared-bindings/_bleio/Service.h"

#include "common-hal/_bleio/Adapter.h"
#include "common-hal/_bleio/att.h"

#define CCCD_NOTIFY   0x1
#define CCCD_INDICATE 0x2


void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self, bleio_service_obj_t *service, uint16_t handle, bleio_uuid_obj_t *uuid, bleio_characteristic_properties_t props, 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, const char *user_description) {
    self->service = service;
    self->uuid = uuid;
    self->decl_handle = BLE_GATT_HANDLE_INVALID;
    self->handle = BLE_GATT_HANDLE_INVALID;
    self->props = props;
    self->read_perm = read_perm;
    self->write_perm = write_perm;
    self->descriptor_list = mp_obj_new_list(0, NULL);
    self->observer = mp_const_none;
    self->user_desc = NULL;
    self->cccd = NULL;
    self->sccd = NULL;
    self->value = mp_obj_new_bytes(initial_value_bufinfo->buf, initial_value_bufinfo->len);

    const mp_int_t max_length_max = 512;

    mp_arg_validate_int_range(max_length, 0, max_length_max, MP_QSTR_max_length);

    self->max_length = max_length;
    self->fixed_length = fixed_length;

    if (service->is_remote) {
        self->handle = handle;
    } else {
        common_hal_bleio_service_add_characteristic(self->service, self, initial_value_bufinfo, user_description);
    }
}

mp_obj_tuple_t *common_hal_bleio_characteristic_get_descriptors(bleio_characteristic_obj_t *self) {
    return mp_obj_new_tuple(self->descriptor_list->len, self->descriptor_list->items);
}

bleio_service_obj_t *common_hal_bleio_characteristic_get_service(bleio_characteristic_obj_t *self) {
    return self->service;
}

size_t common_hal_bleio_characteristic_get_max_length(bleio_characteristic_obj_t *self) {
    return self->max_length;
}

size_t common_hal_bleio_characteristic_get_value(bleio_characteristic_obj_t *self, uint8_t *buf, size_t len) {
    // Do GATT operations only if this characteristic has been added to a registered service.
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        // FIX uint16_t conn_handle = bleio_connection_get_conn_handle(self->service->connection);
        if (common_hal_bleio_service_get_is_remote(self->service)) {
            // FIX read remote chars
            // uint8_t rsp[MAX(len, 512)];
            // FIX improve att_read_req to write into our requested buffer.
            // return att_read_req(conn_handle, self->handle, rsp);
            return 0; // FIX
        } else {
            mp_buffer_info_t bufinfo;
            if (!mp_get_buffer(self->value, &bufinfo, MP_BUFFER_READ)) {
                return 0;
            }
            const size_t actual_length = MIN(len, bufinfo.len);
            memcpy(buf, bufinfo.buf, actual_length);
            return actual_length;
        }
    }

    return 0;
}

void common_hal_bleio_characteristic_set_value(bleio_characteristic_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"));
    }

    // Do GATT operations only if this characteristic has been added to a registered service.
    if (self->handle != BLE_GATT_HANDLE_INVALID) {
        if (common_hal_bleio_service_get_is_remote(self->service)) {
            // FIX uint16_t conn_handle = bleio_connection_get_conn_handle(self->service->connection);
            if (self->props & CHAR_PROP_WRITE) {
                // FIX writing remote chars
                // uint8_t rsp[sizeof(bt_att_error_rsp)];
                // att_write_req(conn_handle, self->handle, bufinfo->buf, bufinfo->len, rsp);
            } else if (self->props & CHAR_PROP_WRITE_NO_RESPONSE) {
                // att_write_cmd(conn_handle, self->handle, bufinfo->buff, bufinfo->len);
            } else {
                mp_raise_bleio_BluetoothError(translate("Characteristic not writable"));
            }
        } else {
            // Always write the value locally even if no connections are active.
            bleio_characteristic_set_local_value(self, bufinfo);
            // Notify or indicate all active connections.

            uint16_t cccd_value = 0;
            mp_buffer_info_t cccd_bufinfo = {
                .buf = &cccd_value,
                .len = sizeof(cccd_value),
            };

            const bool notify = self->props & CHAR_PROP_NOTIFY;
            const bool indicate = self->props & CHAR_PROP_INDICATE;
            // Read the CCCD value, if there is one.
            if ((notify | indicate) && self->cccd != NULL) {
                common_hal_bleio_descriptor_get_value(self->cccd, cccd_bufinfo.buf, cccd_bufinfo.len);
            }

            // It's possible that both notify and indicate are set.
            if (notify && (cccd_value & CCCD_NOTIFY)) {
                att_notify(self->handle, bufinfo->buf, MIN(bufinfo->len, self->max_length));
            }
            if (indicate && (cccd_value & CCCD_INDICATE)) {
                att_indicate(self->handle, bufinfo->buf, MIN(bufinfo->len, self->max_length));

            }
        }
    }
}

bleio_uuid_obj_t *common_hal_bleio_characteristic_get_uuid(bleio_characteristic_obj_t *self) {
    return self->uuid;
}

bleio_characteristic_properties_t common_hal_bleio_characteristic_get_properties(bleio_characteristic_obj_t *self) {
    return self->props;
}

void common_hal_bleio_characteristic_add_descriptor(bleio_characteristic_obj_t *self, bleio_descriptor_obj_t *descriptor) {
    if (self->handle != common_hal_bleio_adapter_obj.last_added_characteristic_handle) {
        mp_raise_bleio_BluetoothError(
            translate("Descriptor can only be added to most recently added characteristic"));
    }

    descriptor->handle = bleio_adapter_add_attribute(&common_hal_bleio_adapter_obj, MP_OBJ_TO_PTR(descriptor));
    // Include this descriptor in the service handle's range.
    self->service->end_handle = descriptor->handle;

    mp_obj_list_append(MP_OBJ_FROM_PTR(self->descriptor_list),
        MP_OBJ_FROM_PTR(descriptor));
}

void common_hal_bleio_characteristic_set_cccd(bleio_characteristic_obj_t *self, bool notify, bool indicate) {
    if (self->cccd == NULL) {
        mp_raise_bleio_BluetoothError(translate("No CCCD for this Characteristic"));
    }

    if (!common_hal_bleio_service_get_is_remote(self->service)) {
        mp_raise_bleio_RoleError(translate("Can't set CCCD on local Characteristic"));
    }

    const uint16_t conn_handle = bleio_connection_get_conn_handle(self->service->connection);
    common_hal_bleio_check_connected(conn_handle);

    uint16_t cccd_value =
        (notify ? CCCD_NOTIFY : 0) |
        (indicate ? CCCD_INDICATE : 0);

    // FIX do remote
    (void)cccd_value;
    // uint8_t rsp[sizeof(bt_att_error_rsp)];
    // if (att_write_req(conn_handle, self->cccd->handle, &cccd_value, sizeof(cccd_value)) == 0) {
    //     mp_raise_bleio_BluetoothError(translate("Could not write CCCD"));
    // }
}

bool bleio_characteristic_set_local_value(bleio_characteristic_obj_t *self, mp_buffer_info_t *bufinfo) {
    if (self->fixed_length && bufinfo->len != self->max_length) {
        return false;
    }
    if (bufinfo->len > self->max_length) {
        return false;
    }

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

    if (mp_obj_is_type(self->observer, &bleio_characteristic_buffer_type)) {
        bleio_characteristic_buffer_update(MP_OBJ_FROM_PTR(self->observer), bufinfo);
    } else if (mp_obj_is_type(self->observer, &bleio_packet_buffer_type)) {
        bleio_packet_buffer_update(MP_OBJ_FROM_PTR(self->observer), bufinfo);
    } else {
        return false;
    }
    return true;
}

void bleio_characteristic_set_observer(bleio_characteristic_obj_t *self, mp_obj_t observer) {
    self->observer = observer;
}

void bleio_characteristic_clear_observer(bleio_characteristic_obj_t *self) {
    self->observer = mp_const_none;
}