fuchsia.bluetooth.host

PROTOCOLS

Host

Defined in fuchsia.bluetooth.host/host.fidl

Interface for interacting with a Bluetooth host device (bt-host)

Close

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.

Request

Name	Type

Connect

Establish a BR/EDR and/or LE connection to the peer with identifier id:

• If the peer 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 peer 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.

Request

Name	Type
id	fuchsia.bluetooth/PeerId

Response

Name	Type
result	Host_Connect_Result

Disconnect

Terminate all connections (BR/EDR or LE) to the remote peer with identifier id.

• request 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.

Request

Name	Type
id	fuchsia.bluetooth/PeerId

Response

Name	Type
result	Host_Disconnect_Result

EnableBackgroundScan

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.

Request

Name	Type
enabled	bool

EnablePrivacy

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).

Request

Name	Type
enabled	bool

Forget

Deletes a peer from the Bluetooth host. If the peer is connected, it will be disconnected. device_id will no longer refer to any peer, even if a device with the same address 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.

Request

Name	Type
id	fuchsia.bluetooth/PeerId

Response

Name	Type
result	Host_Forget_Result

OnNewBondingData

Notifies when bonding data for a peer has been updated.

Response

Name	Type
data	fuchsia.bluetooth.sys/BondingData

Pair

Initiates pairing to the peer with the supplied id and options. Returns an error if no connected peer with id is found or the pairing procedure fails.

If options specifies a higher security level than the current pairing, this method attempts to raise the security level. Otherwise this method has no effect and returns success.

NOTE: This is intended to satisfy test scenarios that require pairing procedures to be initiated without relying on service access. In normal operation, Bluetooth security is enforced during service access.

Request

Name	Type
id	fuchsia.bluetooth/PeerId
options	fuchsia.bluetooth.sys/PairingOptions

Response

Name	Type
result	Host_Pair_Result

RequestGattServer

Request

Name	Type
server	request<fuchsia.bluetooth.gatt/Server>

RequestLowEnergyCentral

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.

Request

Name	Type
central	request<fuchsia.bluetooth.le/Central>

RequestLowEnergyPeripheral

Request

Name	Type
peripheral	request<fuchsia.bluetooth.le/Peripheral>

RequestProfile

Request

Name	Type
profile	request<fuchsia.bluetooth.bredr/Profile>

RestoreBonds

Restores existing bonded devices to the host. An authenticated session will be established for future connections using the provided bonding data.

If bonding data for the LE transport is available, then the host will automatically establish a connection when the peer is in range and connectable.

If any of the entries in bonds could not be restored, then they will be returned in errors. This can happen for entries that are malformed and for peers that are already known to the bt-host. An empty errors list indicates that all bonds were successfully restored.

Request

Name	Type
bonds	vector<fuchsia.bluetooth.sys/BondingData>

Response

Name	Type
errors	vector<fuchsia.bluetooth.sys/BondingData>

SetConnectable

Sets whether this host should be connectable.

Request

Name	Type
enabled	bool

Response

Name	Type
result	Host_SetConnectable_Result

SetDeviceClass

Sets the device class for this host device.

Request

Name	Type
device_class	fuchsia.bluetooth/DeviceClass

Response

Name	Type
result	Host_SetDeviceClass_Result

SetDiscoverable

Sets whether this host should be discoverable.

Request

Name	Type
enabled	bool

Response

Name	Type
result	Host_SetDiscoverable_Result

SetLeSecurityMode

Set the GAP LE Security Mode of the host. bt-host only supports encrypted, connection-based security modes, i.e. Mode 1 and Secure Connections Only mode. If the security mode is set to Secure Connections Only, any existing encrypted connections which do not meet the security requirements of Secure Connections Only mode will be disconnected.

Request

Name	Type
le_security_mode	fuchsia.bluetooth.sys/LeSecurityMode

SetLocalData

Assigns local data to this host.

Request

Name	Type
host_data	fuchsia.bluetooth.sys/HostData

SetLocalName

Sets the local name for this host device.

Request

Name	Type
local_name	string

Response

Name	Type
result	Host_SetLocalName_Result

SetPairingDelegate

Assigns the pairing delegate that will respond to authentication challenges using the given I/O capabilities. Calling this method cancels any on-going pairing procedure started using a previous delegate. Pairing requests will be rejected if no PairingDelegate has been assigned.

Request

Name	Type
input	fuchsia.bluetooth.sys/InputCapability
output	fuchsia.bluetooth.sys/OutputCapability
delegate	fuchsia.bluetooth.sys/PairingDelegate

StartDiscovery

Initiates a general discovery procedure for BR/EDR and LE devices. On success, discovered peers can be monitored using the Host.WatchPeers method.

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 Host protocol channel gets closed. If the device does not support BR/EDR, only LE discovery will be performed.

Request

Name	Type

Response

Name	Type
result	Host_StartDiscovery_Result

StopDiscovery

Terminates discovery if one was started via StartDiscovery().

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.

Request

Name	Type

WatchPeers

Monitors updates for connectable peers known to the system. Replies only when peers have been added, modified, or removed since the most recent call to WatchPeers().

Peers are added and updated as new information is obtained during discovery, connection establishment, and bonding procedures.

Peers are removed either: a. explicitly via fuchsia.bluetooth.host.Host/Forget, or b. no transmission has been received from the peer for an internally determined duration of time and the peer is neither connected nor bonded.

• response updated Peers that were added or updated since the last call to WatchPeers().
• response removed Ids of peers that were removed since the last call to WatchPeers().

Request

Name	Type

Response

Name	Type
updated	vector<fuchsia.bluetooth.sys/Peer>
removed	vector<fuchsia.bluetooth/PeerId>

WatchState

Returns information about the Bluetooth host subsystem and controller managed by this Host instance. If there has been no change to the state since the last call to this method, the response will be deferred until there is a change.

The returned info structure will be populated with the current state of the bt-host device. However the active parameter will never be populated. This field is managed by a higher layer.

Request

Name	Type

Response

Name	Type
info	fuchsia.bluetooth.sys/HostInfo

STRUCTS

Host_Connect_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_Disconnect_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_Forget_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_Pair_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_SetConnectable_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_SetDeviceClass_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_SetDiscoverable_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_SetLocalName_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

Host_StartDiscovery_Response

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description	Default

UNIONS

Host_Connect_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_Connect_Response
err	fuchsia.bluetooth.sys/Error

Host_Disconnect_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_Disconnect_Response
err	fuchsia.bluetooth.sys/Error

Host_Forget_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_Forget_Response
err	fuchsia.bluetooth.sys/Error

Host_Pair_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_Pair_Response
err	fuchsia.bluetooth.sys/Error

Host_SetConnectable_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_SetConnectable_Response
err	fuchsia.bluetooth.sys/Error

Host_SetDeviceClass_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_SetDeviceClass_Response
err	fuchsia.bluetooth.sys/Error

Host_SetDiscoverable_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_SetDiscoverable_Response
err	fuchsia.bluetooth.sys/Error

Host_SetLocalName_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_SetLocalName_Response
err	fuchsia.bluetooth.sys/Error

Host_StartDiscovery_Result

Defined in fuchsia.bluetooth.host/host.fidl

Name	Type	Description
response	Host_StartDiscovery_Response
err	fuchsia.bluetooth.sys/Error