sdk/fidl/fuchsia.bluetooth.le/advertising_data.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.bluetooth.le;

using fuchsia.bluetooth as bt;

// The size of the BT-encoded ServiceData field must fit into a uint8, so the max allowed data
// size is 255 (uint8::MAX) - 1 byte (field type) - 2 bytes (minimum possible encoded UUID size).
const uint8 MAX_SERVICE_DATA_LENGTH = 252;

// The size of the BT-encoded ServiceData field must fit into a uint8, so the max allowed data size
// is 255 (uint8::MAX) - 1 byte (field type) - 2 bytes (company ID size).
const uint8 MAX_MANUFACTURER_DATA_LENGTH = 252;

// The size of each BT-encoded URI must fit into a uint8. Recognized encoding schemes are compressed
// to 1 encoded byte, so encoded URIs are |original length| - (|encoding scheme| + 1) bytes. This
// leads to a formula for the maximum URI length of |longest_scheme_str| - 1 byte (encoding) +
// uint8::MAX - 1 byte (field type). The longest_scheme_str is "ms-settings-cloudstorage:", of
// length 25, leading to a limit of 25 - 1 + 255 - 1 = 278.
const uint16 MAX_URI_LENGTH = 278;

/// Entry in the `service_data` field of a [`fuchsia.bluetooth.le/AdvertisingData`].
struct ServiceData {
    bt.Uuid uuid;
    bytes:MAX_SERVICE_DATA_LENGTH data;
};

/// Entry in the `manufacturer_data` field of a [`fuchsia.bluetooth.le/AdvertisingData`].
struct ManufacturerData {
    uint16 company_id;
    bytes:MAX_MANUFACTURER_DATA_LENGTH data;
};

/// Represents advertising and scan response data that are transmitted by a LE peripheral or
/// broadcaster.
table AdvertisingData {
    /// Long or short name of the device.
    1: bt.DeviceName name;

    /// The appearance of the device.
    2: bt.Appearance appearance;

    /// The radio transmit power level reported by an advertising peer. This field is disallowed
    /// when used with the Peripheral API.
    3: int8 tx_power_level;

    /// Service UUIDs.
    4: vector<bt.Uuid>:MAX service_uuids;

    /// Service data entries.
    5: vector<ServiceData>:MAX service_data;

    /// Manufacturer-specific data entries.
    6: vector<ManufacturerData>:MAX manufacturer_data;

    /// String representing a URI to be advertised, as defined in [IETF STD 66](https://tools.ietf.org/html/std66).
    /// Each entry should be a UTF-8 string including the scheme. For more information, see:
    /// - https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml for allowed schemes;
    /// - https://www.bluetooth.com/specifications/assigned-numbers/uri-scheme-name-string-mapping
    ///   for code-points used by the system to compress the scheme to save space in the payload.
    7: vector<string:MAX_URI_LENGTH>:MAX uris;
};