sdk/fidl/fuchsia.bluetooth.gatt2/types.fidl

// Copyright 2021 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.gatt2;

using fuchsia.bluetooth as bt;

/// Errors that are returned by bluetooth.gatt2 methods.
type Error = strict enum {
    /// A general error occurred that can not be classified as one of the more
    /// specific errors.
    FAILURE = 1;

    /// Indicates that the response received from the server was invalid.
    INVALID_RESPONSE = 2;

    /// Indicates that more results were read than can fit in a FIDL response.
    /// Consider reading attributes individually.
    TOO_MANY_RESULTS = 3;

    /// This attribute requires authorization, but the client is not authorized.
    INSUFFICIENT_AUTHORIZATION = 4;

    /// This attribute requires authentication, but the client is not authenticated.
    INSUFFICIENT_AUTHENTICATION = 5;

    /// This attribute requires a connection encrypted by a larger encryption key.
    INSUFFICIENT_ENCRYPTION_KEY_SIZE = 6;

    /// This attribute requires encryption, but the connection is not encrypted.
    INSUFFICIENT_ENCRYPTION = 7;

    /// This attribute is not readable.
    READ_NOT_PERMITTED = 8;

    /// This attribute is not writable.
    WRITE_NOT_PERMITTED = 9;

    /// One or more of the parameters are invalid. See the parameter documentation.
    INVALID_PARAMETERS = 10;

    /// The attribute indicated by the handle is invalid. It may have been removed.
    INVALID_HANDLE = 11;
};

// A Handle uniquely identifies a service, characteristic, or descriptor.
type Handle = struct {
    value uint64;
};

/// Represents encryption, authentication, and authorization permissions that can
/// be assigned to a specific access permission.
type SecurityRequirements = table {
    /// If true, the physical link must be encrypted to access this attribute.
    1: encryption_required bool;

    /// If true, the physical link must be authenticated to access this
    /// attribute.
    2: authentication_required bool;

    /// If true, the client needs to be authorized before accessing this
    /// attribute.
    3: authorization_required bool;
};

/// Specifies the access permissions for a specific attribute value.
type AttributePermissions = table {
    /// Specifies whether or not an attribute has the read permission. If null,
    /// then the attribute value cannot be read. Otherwise, it can be read only if
    /// the permissions specified in the SecurityRequirements table are satisfied.
    1: read SecurityRequirements;

    /// Specifies whether or not an attribute has the write permission. If null,
    /// then the attribute value cannot be written. Otherwise, it be written only
    /// if the permissions specified in the SecurityRequirements table are satisfied.
    2: write SecurityRequirements;

    /// Specifies the security requirements for a client to subscribe to
    /// notifications or indications on a characteristic. A characteristic's
    /// support for notifications or indiciations is specified using the NOTIFY and
    /// INDICATE characteristic properties. If a local characteristic has one of
    /// these properties then this field can not be null. Otherwise, this field
    /// must be left as null.
    ///
    /// This field is ignored for Descriptors.
    3: update SecurityRequirements;
};

/// Possible values for the characteristic properties bitfield. These specify the
/// GATT procedures that are allowed for a particular characteristic.
type CharacteristicPropertyBits = strict bits : uint16 {
    BROADCAST = 0x1;
    READ = 0x2;
    WRITE_WITHOUT_RESPONSE = 0x4;
    WRITE = 0x8;
    NOTIFY = 0x10;
    INDICATE = 0x20;
    AUTHENTICATED_SIGNED_WRITES = 0x40;
    RELIABLE_WRITE = 0x100;
    WRITABLE_AUXILIARIES = 0x200;
};

/// Represents a local or remote GATT service.
type ServiceInfo = table {
    /// Uniquely identifies this GATT service. Always present if this represents
    /// a remote service. Ignored if present for local services.
    1: handle Handle;

    /// Indicates whether this is a primary or secondary service.
    /// Always present for remote services. Optional for local services
    /// Default: true
    2: primary bool;

    /// The UUID that identifies the type of this service.
    /// There may be multiple services with the same UUID.
    /// Always present for remote services. Required for local services.
    3: type bt.Uuid;

    /// The characteristics of this service.
    /// Required for local services. Never present for remote services.
    4: characteristics vector<Characteristic>:MAX_CHARACTERISTIC_COUNT;

    /// Handles of other services that are included by this service.
    /// Optional for local services. Never present for remote services.
    5: includes vector<Handle>:MAX_SERVICE_COUNT;
};

/// Represents a local or remote GATT characteristic.
type Characteristic = table {
    /// Uniquely identifies this characteristic within a service.
    /// For local characteristics, the specified handle must be unique across
    /// all characteristic and descriptor handles in this service.
    ///
    /// Always present. For local characteristics, this value is mandatory.
    1: handle Handle;

    /// The UUID that identifies the type of this characteristic.
    /// Always present. Mandatory for local characteristics.
    2: type bt.Uuid;

    /// The characteristic properties bitfield. See `CharacteristicPropertyBits`
    /// above for possible values.
    /// Always present. Mandatory for local characteristics.
    3: properties uint32;

    /// The attribute permissions of this characteristic. For remote
    /// characteristics, this value will be null until the permissions are
    /// discovered via read and write requests.
    ///
    /// For local characteristics, this value is mandatory.
    4: permissions AttributePermissions;

    /// The descriptors of this characteristic.
    /// Present only if non-empty. Optional for local characteristics.
    5: descriptors vector<Descriptor>:MAX_DESCRIPTOR_COUNT;
};

/// Represents a local or remote GATT characteristic descriptor.
type Descriptor = table {
    /// Uniquely identifies this descriptor within a service.
    /// For local descriptors, the specified handle must be unique
    /// across all characteristic and descriptor handles in this service.
    ///
    /// Always present. For local descriptors, this value is mandatory.
    1: handle Handle;

    /// The UUID that identifies the type of this descriptor.
    /// Always present. For local descriptors, this value is mandatory.
    2: type bt.Uuid;

    /// The attribute permissions of this descriptor. For remote
    /// descriptors, this value will be null until the permissions are
    /// discovered via read and write requests.
    ///
    /// For local descriptors, this value is mandatory.
    3: permissions AttributePermissions;
};

/// Represents the supported options to read a long characteristic or descriptor
/// value from a server. Long values are those that may not fit in a single
/// message (longer than 22 bytes).
type LongReadOptions = table {
    /// The byte to start the read at. Must be less than the length of the value.
    /// Optional.
    /// Default: 0
    1: offset uint16;
    /// The maximum number of bytes to read.
    /// Optional.
    /// Default: `MAX_VALUE_LENGTH`
    2: max_bytes uint16;
};

/// Represents the options for reading a short characteristic or descriptor
/// value from a server. Short values are those that fit in a single message,
/// which is at least 22 bytes. This is an empty placeholder for now, as there
/// are no options.
type ShortReadOptions = struct {};

/// Represents the supported options to read a characteristic or descriptor
/// value from a server.
type ReadOptions = flexible union {
    /// Perform a short read, which may be truncated (as indicated by the
    /// maybe_truncated in the result)
    /// Most reads in GATT services are short reads (<= 22 bytes).
    1: short_read ShortReadOptions;
    /// If present, perform a long read using the indicated options.
    /// Optional.
    /// Default: A short read will be performed.
    2: long_read LongReadOptions;
};

/// Represents the supported write modes for writing characteristics &
/// descriptors to the server.
type WriteMode = flexible enum {
    /// In `DEFAULT` mode, wait for a response from the server before returning
    /// and do not verify the echo response.
    /// Supported for both characteristics and descriptors.
    DEFAULT = 1;
    /// In `RELIABLE` mode, every value blob is verified against an echo
    /// response from the server. The procedure is aborted if a value blob has
    /// not been reliably delivered to the peer.
    /// Only supported for characteristics.
    RELIABLE = 2;
    /// In `WITHOUT_RESPONSE` mode, delivery will not be confirmed before
    /// returning. Writing without a response is only supported for short
    /// characteristics with the `WRITE_WITHOUT_RESPONSE` property. The value
    /// must fit into a single message. It is guaranteed that at least 20 bytes
    /// will fit into a single message. If the value does not fit, a `FAILURE`
    /// error will be produced. The value will be written at offset 0.
    /// Only supported for characteristics.
    WITHOUT_RESPONSE = 3;
};

/// Represents the supported options to write a characteristic/descriptor value
/// to a server.
type WriteOptions = table {
    /// The mode of the write operation. For descriptors, only
    /// [`WriteMode.DEFAULT`] is supported
    /// Optional.
    /// Default: [`WriteMode.DEFAULT`]
    1: write_mode WriteMode;
    /// Request a write starting at the byte indicated.
    /// Must be missing or 0 if `write_mode` is [`WriteMode.WITHOUT_RESPONSE`].
    /// Optional.
    /// Default: 0
    2: offset uint16;
};