src/connectivity/bluetooth/fidl/host.fidl

// Copyright 2018 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.host;

using fuchsia.bluetooth;
using fuchsia.bluetooth.bredr;
using fuchsia.bluetooth.control;
using fuchsia.bluetooth.gatt;
using fuchsia.bluetooth.le;

/// Interface for interacting with a Bluetooth host device (bt-host)
protocol Host {
    /// The following methods fulfill a given interface request. bt-host device
    /// will start processing FIDL messages. If the request cannot be fulfilled,
    /// the bt-host device will close its end of the given channel.
    RequestLowEnergyCentral(request<fuchsia.bluetooth.le.Central> central);
    RequestLowEnergyPeripheral(request<fuchsia.bluetooth.le.Peripheral> peripheral);
    RequestGattServer(request<fuchsia.bluetooth.gatt.Server> server);
    RequestProfile(request<fuchsia.bluetooth.bredr.Profile> profile);

    /// Shuts down the host, ending all active Bluetooth procedures:
    ///
    /// * All FIDL interface handles associated with this host are closed and all
    ///   connections initiated via FIDL clients are severed.
    /// * All scan, discovery, and advertising procedures are stopped.
    /// * Bonded devices are cleared and removed from the auto-connect lists.
    /// * Auto-connected peripherals are disconnected.
    ///
    /// This effectively resets the host to its initial state and the host remains
    /// available for future requests.
    ///
    /// The Host will continue to send OnDeviceUpdated events as procedures get
    /// terminated.
    Close();

    /// Returns information about the Bluetooth adapter managed by this host.
    GetInfo() -> (fuchsia.bluetooth.control.AdapterInfo info);

    /// Assigns local data to this host.
    SetLocalData(fuchsia.bluetooth.control.HostData host_data);

    /// Returns a list of all known connectable devices, included those that are
    /// currently connected and/or bonded. This list does not include
    /// non-connectable devices such as LE broadcasters.
    ///
    /// Notes:
    ///
    /// - When used in the GAP central role (BR/EDR or LE) the listed devices are
    /// obtained during discovery and connection procedures. While in the
    /// peripheral role, this will contain devices that have successfully initiated
    /// connections to this host.
    ///
    /// - This list contains connectable devices that are discovered or connected
    /// via other interfaces obtained using the interface request methods declared
    /// above.
    ListDevices() -> (vector<fuchsia.bluetooth.control.RemoteDevice> devices);

    /// Sets the local name for this adapter.
    SetLocalName(string local_name) -> (fuchsia.bluetooth.Status status);

    /// Sets the device class for this adapter.
    SetDeviceClass(fuchsia.bluetooth.control.DeviceClass device_class)
        -> (fuchsia.bluetooth.Status status);

    /// Initiates a general discovery procedure for BR/EDR and LE devices. On success, discovered
    /// devices will be reported via AdapterDelegate.OnDeviceDiscovered().
    ///
    /// On the LE transport, only general-discoverable and connectable peripherals will be reported.
    ///
    /// Discovery will continue until it is terminated via StopDiscovery() or if the proxy to the
    /// Adapter gets disconnected. If the device does not support BR/EDR, only LE
    /// discovery will be performed.
    ///
    /// An OnDeviceUpdated event will be sent when the discovery procedures are
    /// started.
    StartDiscovery() -> (fuchsia.bluetooth.Status status);

    /// Terminates discovery if one was started via StartDiscovery(). The AdapterDelegate will stop
    /// receiving device discovery notifications.
    ///
    /// NOTE: If another client is performing discovery (e.g. via its own le.Central interface handle),
    /// then the system will continue performing device discovery even if this method results in
    /// success.
    StopDiscovery() -> (fuchsia.bluetooth.Status status);

    /// Sets whether this host should be connectable.
    SetConnectable(bool enabled) -> (fuchsia.bluetooth.Status status);

    /// Sets whether this host should be discoverable.
    SetDiscoverable(bool enabled) -> (fuchsia.bluetooth.Status status);

    /// Establish a BR/EDR and/or LE connection to the remote device with identifier `device_id`:
    ///
    ///   - If the device is known to support the BR/EDR transport then a logical link over that
    ///     transport will be established to the device. If the connection attempt is successful,
    ///     local services registered using "RequestProfile()" will be available to the peer.
    ///     Traditional services discovered on the peer will be notified to local services
    ///     asynchronously.
    ///
    ///   - If the device is known to support the LE transport then a logical link over that
    ///     transport will be established to the device. If the connection attempt is successful,
    ///     GATT services in the local database (populated via RequestGattServer()) will become
    ///     available to the peer. Similarly, remote GATT services that are discovered on the
    ///     peer will become available to holders of a gatt.Client capability and to device drivers
    ///     that can bind to the bt-gatt-svc class of devices.
    ///
    /// The result of the procedure will be communicated via `status`. If the remote device
    /// supports both BR/EDR and LE transports and a link cannot be established over both, then an
    /// error Status will be returned and neither transport will be connected.
    Connect(string device_id) -> (fuchsia.bluetooth.Status status);

    /// Terminate all connections (BR/EDR or LE) to the remote peer with identifier `peer_id`.
    ///
    /// + request `peer_id` The identifier of the peer to disconnect.
    /// - response `status` Contains an error if either LE or BR/EDR transport fails to disconnect. Contains
    ///                     success when both transports are successfully disconnected or if the peer is already
    ///                     disconnected.
    Disconnect(string peer_id) -> (fuchsia.bluetooth.Status status);

    /// Deletes a peer from the Bluetooth host. If the peer is connected, it will be disconnected,
    /// then OnDeviceUpdated will be sent. OnDeviceRemoved will be sent. `device_id` will no longer
    /// refer to any peer, even if a device with the same address(es) is discovered again.
    ///
    /// Returns success after no peer exists that's identified by `device_id` (even if it didn't
    /// exist before Forget), failure if the peer specified by `device_id` could not be
    /// disconnected or deleted and still exists.
    Forget(string device_id) -> (fuchsia.bluetooth.Status status);

    /// Enable or disable a passive LE background scan. When enabled, the bt-host
    /// device will continuously perform a passive LE scan in the background when
    /// no device discovery sessions are active and accept connection requests from
    /// bonded peripherals.
    EnableBackgroundScan(bool enabled);

    /// Enable or disable the LE privacy feature. When enabled, the bt-host device will use a private
    /// device address in all LE procedures. When disabled, the public identity address will be used
    /// instead (which is the default).
    EnablePrivacy(bool enabled);

    /// Assigns the pairing delegate that will respond to authentication challenges using the given
    /// I/O capabilities. Setting a pairing delegate cancels any on-going pairing procedure started
    /// using a previous delegate. Pairing requests will be rejected if no PairingDelegate has been
    /// assigned.
    SetPairingDelegate(
        fuchsia.bluetooth.control.InputCapabilityType input,
        fuchsia.bluetooth.control.OutputCapabilityType output,
        fuchsia.bluetooth.control.PairingDelegate? delegate);

    /// Adds existing bonded devices to the host. The host will be configured to automatically connect
    /// to these devices when they are in range and connectable. Future connections will be encrypted
    /// using the provided bonding data.
    AddBondedDevices(vector<fuchsia.bluetooth.control.BondingData> bonds) -> (fuchsia.bluetooth.Status status);

    // ===== Events =====

    /// Notifies when the adapter state changes.
    -> OnAdapterStateChanged(fuchsia.bluetooth.control.AdapterState state);

    /// Events that are sent when a connectable device is added, updated, or
    /// removed as a result of connection and discovery procedures.
    -> OnDeviceUpdated(fuchsia.bluetooth.control.RemoteDevice device);
    -> OnDeviceRemoved(string identifier);

    /// Notifies when bonding data for a device has been updated.
    -> OnNewBondingData(fuchsia.bluetooth.control.BondingData data);

    // TODO(BT-194): Introduce a "OnBondRemoved()" event to notify when existing
    // keys become stale.
};