fuchsia.bluetooth.sys

Protocol that abstracts the operational modes and procedures defined in the Bluetooth Generic Access Profile (see Core Specification v5.1, Vol 3, Part C).

The procedures under this protocol apply to the system as a whole. The Bluetooth controller that plays an active role in these procedures can be managed using the HostWatcher protocol.

The procedures initiated by an Access protocol instance are terminated when the underlying channel is closed.

Connect

Initiate a connection to the peer with the given id. This method connects both BR/EDR and LE transports depending on the technologies that the peer is known to support.

request id The id of the peer to connect.

error Reports Error.FAILED if a connection to the peer cannot be initiated.
error Reports Error.PEER_NOT_FOUND if id is not recognized.

Request

Name	Type
`id`	`fuchsia.bluetooth/PeerId`

Response

Name	Type
`result`	`Access_Connect_Result`

Disconnect

Disconnect all logical links to the peer with the given id. This includes LE and BR/EDR links that have been initiated using all Access and fuchsia.bluetooth.le protocol instances.

request id The id of the peer to disconnect.

error Reports Error.PEER_NOT_FOUND if id is not recognized.

Request

Name	Type
`id`	`fuchsia.bluetooth/PeerId`

Response

Name	Type
`result`	`Access_Disconnect_Result`

Forget

Removes all bonding information and disconnects any existing links with the peer with the given id.

request id The id of the peer to forget.

error Reports Error.PEER_NOT_FOUND if id is not recognized.

Request

Name	Type
`id`	`fuchsia.bluetooth/PeerId`

Response

Name	Type
`result`	`Access_Forget_Result`

MakeDiscoverable

Put the system into the "General Discoverable" mode on the BR/EDR transport. The active host will respond to general inquiry (by regularly entering the inquiry scan mode).

request token ProcedureToken that will remain valid while a discoverable mode session is active. NOTE: The system may remain discoverable until all Access clients drop their tokens.

error Reports Error.FAILED if inquiry mode cannot be entered.

Request

Name	Type
`token`	`request<ProcedureToken>`

Response

Name	Type
`result`	`Access_MakeDiscoverable_Result`

Pair

Initiate a pairing to the remote id with the given options. This call completes only once the pairing procedure has completed or aborted. Returns an error if no connected peer with id is found or the pairing procedure fails. If the named peer is already paired, this returns immediately with a success value - unless the pairing is over LE and the PairingOptions.le_security_level is more secure than the current security level, in which case we will attempt to raise security to the requested level.

Pairing will take place over whichever transport is indicated by options.transport. If that transport isn't currently connected, the pairing will fail with Error.PEER_NOT_FOUND. Currently, if DUAL_MODE is requested, we will attempt to pair over the LE transport.

request id The id of the peer to initiate pairing with
request options The configuration options to use for this pairing request

error Reports Error.PEER_NOT_FOUND if id is not recognized, or the peer is not connected on the requested transport.
error Reports Error.INVALID_ARGUMENTS if ill-formed options are passed
error Reports Error.FAILED if an error occurs during pairing

Request

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

Response

Name	Type
`result`	`Access_Pair_Result`

SetDeviceClass

Set the local device class that will be visible to nearby peers when the system is in discoverable mode.

request device_class The device class to assign to the system.

Request

Name	Type
`device_class`	`fuchsia.bluetooth/DeviceClass`

SetLocalName

Assign a local name for the Bluetooth system. This name will be visible to nearby peers when the system is in discoverable mode and during name discovery procedures.

request name The complete local name to assign to the system.

Request

Name	Type
`name`	`string`

SetPairingDelegate

Assign a PairingDelegate to respond to drive pairing procedures. The delegate will be configured to use the provided I/O capabilities to determine the pairing method.

Only one PairingDelegate can be registered at a time. Closing a PairingDelegate aborts all on-going pairing procedures associated with a delegate and closes the PairingDelegate previously assigned for this Access instance.

request input Bluetooth input capability
request output Bluetooth output capability
request delegate The client end of a PairingDelegate channel.

Request

Name	Type
`input`	`InputCapability`
`output`	`OutputCapability`
`delegate`	`PairingDelegate`

StartDiscovery

Start a general discovery procedure. All general discoverable BR/EDR, LE, and BR/EDR/LE devices will appear in the peer list, which can be observed by calling Access.WatchPeers.

request token ProcedureToken that will remain valid while discovery is in progress. NOTE: The radio will continue performing discovery until all Access drop their tokens.

error Reports Error.FAILED if discovery on either transport cannot be initiated.

Request

Name	Type
`token`	`request<ProcedureToken>`

Response

Name	Type
`result`	`Access_StartDiscovery_Result`

WatchPeers

Returns a list of all peers (connectable Bluetooth devices) known to the system. The first call results in a snapshot of all known peers to be sent immediately in the updated return paremeter. Subsequent calls receive a response only when one or more entries have been added, modified, or removed from the entries reported since the most recent call.

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<Peer>`
`removed`	`vector<fuchsia.bluetooth/PeerId>`

Bootstrap

Protocol used to initialize persistent core Bluetooth data. This protocol populates data that determine the identity of this device as perceived by other Bluetooth devices.

This protocol can be obtained only before the core Bluetooth host subsystem has generated its own identity. Once initial data is committed, this capability becomes unavailable and remains unavailable even if new Bluetooth adapters are attached.

Due to the privacy and bonding secrets involved, as well as the capability to make this device assume the Bluetooth identity of another device, this protocol should only be exposed to privileged components that can vouchsafe the origin of the data.

AddIdentities

Adds identities to be added to the unpopulated Bluetooth stack.

Repeated calls will append identities.

Request

Name	Type
`identities`	`vector<Identity>`

Commit

Writes all added bootstrapping data to the Bluetooth core stack. The server will close the channel regardless of success. Returns without error if successful and the stack will be considered initialized even if no bootstrapping data was written. Returns INVALID_HOST_IDENTITY if any host or bonded peer data is insufficient or inconsistent, with no effect (the client may retry by obtaining another protocol handle).

Request

Name	Type

Response

Name	Type
`result`	`Bootstrap_Commit_Result`

HostWatcher

Defined in fuchsia.bluetooth.sys/host_watcher.fidl

Protocol used to observe and manage the Bluetooth controllers on the system.

SetActive

Designates the host with the given id as active. All Bluetooth procedures will be routed over this host. Any previously assigned active host will be disabled and all of its pending procedures will be terminated.

error This can fail if a host with id was not found.

Request

Name	Type
`id`	`fuchsia.bluetooth/HostId`

Response

Name	Type
`result`	`HostWatcher_SetActive_Result`

Watch

Obtain a list of all available Bluetooth controllers and their state. A response is sent only if this list has changed since the last time the client has sent this message.

Request

Name	Type

Response

Name	Type
`hosts`	`vector<HostInfo>`

PairingDelegate

Defined in fuchsia.bluetooth.sys/pairing_delegate.fidl

OnLocalKeypress

The delegate can send this event to notify the peer of local keypresses during pairing using PairingMethod.PASSKEY_ENTRY.

Response

Name	Type
`id`	`fuchsia.bluetooth/PeerId`
`keypress`	`PairingKeypress`

OnPairingComplete

Called if the pairing procedure for the device with the given ID is completed. This can be due to successful completion or an error (e.g. due to cancellation by the peer, a timeout, or disconnection) which is indicated by success.

Request

Name	Type
`id`	`fuchsia.bluetooth/PeerId`
`success`	`bool`

OnPairingRequest

Called to initiate a pairing request. The delegate must respond with “true” or “false” to either accept or reject the pairing request. If the pairing method requires a passkey this is returned as well.

Any response from this method will be ignored if the OnPairingComplete event has already been sent for peer.

The displayed_passkey parameter should be displayed to the user if method equals PairingMethod.PASSKEY_DISPLAY or PairingMethod.PASSKEY_COMPARISON. Otherwise, this parameter has no meaning and should be ignored.

The entered_passkey parameter only has meaning if method equals PairingMethod.PASSKEY_ENTRY. It will be ignored otherwise.

Request

Name	Type
`peer`	`Peer`
`method`	`PairingMethod`
`displayed_passkey`	`uint32`

Response

Name	Type
`accept`	`bool`
`entered_passkey`	`uint32`

OnRemoteKeypress

Called to notify keypresses from the peer device during pairing using PairingMethod.PASSKEY_DISPLAY.

This event is used to provide key press events to the delegate for a responsive user experience as the user types the passkey on the peer device. This event will be called once for each key-press.

Request

Name	Type
`id`	`fuchsia.bluetooth/PeerId`
`keypress`	`PairingKeypress`

ProcedureToken

Represents an active procedure. The validity of a handle that supports this protocol is tied to the activity of the procedure that it is attached to. To elaborate:

Closing a token handle ends the procedure that it is attached to.
The system closes a token handle to communicate that a procedure was internally terminated.

STRUCTS

Access_Connect_Response

Name	Type	Description	Default

Access_Disconnect_Response

Name	Type	Description	Default

Access_Forget_Response

Name	Type	Description	Default

Access_MakeDiscoverable_Response

Name	Type	Description	Default

Access_Pair_Response

Name	Type	Description	Default

Access_StartDiscovery_Response

Name	Type	Description	Default

Bootstrap_Commit_Response

Name	Type	Description	Default

HostWatcher_SetActive_Response

Defined in fuchsia.bluetooth.sys/host_watcher.fidl

Name	Type	Description	Default

Key

Represents a 128-bit secret key.

Name	Type	Description	Default
`value`	`uint8[16]`		No default

LeConnectionParameters

The preferred LE connection parameters of the peer.

Name	Type	Default
`connection_interval`	`uint16`	No default
`connection_latency`	`uint16`	No default
`supervision_timeout`	`uint16`	No default

Ltk

Represents a LE Long-Term peer key used for link encyrption. The ediv and rand fields are zero if distributed using LE Secure Connections pairing.

Name	Type	Default
`key`	`PeerKey`	No default
`ediv`	`uint16`	No default
`rand`	`uint64`	No default

PeerKey

Represents a key that was received from a peer.

Name	Type	Description	Default
`security`	`SecurityProperties`	The security properties of this link under which this key was received.	No default
`data`	`Key`	The contents of the key.	No default

SecurityProperties

Name	Type	Default
`authenticated`	`bool`	No default
`secure_connections`	`bool`	No default
`encryption_key_size`	`uint8`	No default

ENUMS

BondableMode

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_options.fidl

Whether or not the device should form a bluetooth bond during the pairing prodecure. As described in Core Spec v5.2 | Vol 3, Part C, Sec 4.3

Name	Value	Description
`BONDABLE`	`1`	The device will form a bond during pairing with peers
`NON_BONDABLE`	`2`	The device will not form a bond during pairing with peers

BootstrapError

Type: uint32

Name	Value	Description
`INVALID_HOST_IDENTITY`	`1`
`WRITE_FAILURE`	`2`

Error

Type: uint32

Name	Value	Description
`FAILED`	`1`	Operation could not be performed.
`PEER_NOT_FOUND`	`2`	The peer designated for the operation was not found.
`TIMED_OUT`	`3`	The time limit for the operation has expired.
`CANCELED`	`4`	The operation was canceled.
`IN_PROGRESS`	`5`	Operation already in progress.
`NOT_SUPPORTED`	`6`	Operation not supported.
`INVALID_ARGUMENTS`	`7`	The operation was given an invalid set of arguments.

InputCapability

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_delegate.fidl

Input and Output Capabilities for pairing exchanges. See Volume 3, Part C, Table 5.3 and 5.4

Name	Value	Description
`NONE`	`1`
`CONFIRMATION`	`2`
`KEYBOARD`	`3`

OutputCapability

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_delegate.fidl

Name	Value	Description
`NONE`	`1`
`DISPLAY`	`2`

PairingKeypress

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_delegate.fidl

Name	Value	Description
`DIGIT_ENTERED`	`1`	The user has entered a single digit.
`DIGIT_ERASED`	`2`	The user has erased a single digit.
`PASSKEY_CLEARED`	`3`	The user has cleared the entire passkey.
`PASSKEY_ENTERED`	`4`	The user has finished entering the passkey.

PairingMethod

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_delegate.fidl

Different types required by the Security Manager for pairing methods. Bluetooth SIG has different requirements for different device capabilities.

Name	Value	Description
`CONSENT`	`1`	The user is asked to accept or reject pairing.
`PASSKEY_DISPLAY`	`2`	The user is shown a 6-digit numerical passkey which they must enter on the peer device.
`PASSKEY_COMPARISON`	`3`	The user is shown a 6-digit numerical passkey which will also shown on the peer device. The user must compare the passkeys and accept the pairing if the passkeys match.
`PASSKEY_ENTRY`	`4`	The user is asked to enter a 6-digit passkey.

PairingSecurityLevel

Type: uint32

Defined in fuchsia.bluetooth.sys/pairing_options.fidl

The security level required for this pairing - corresponds to the security levels defined in the Security Manager Protocol in Vol 3, Part H, Section 2.3.1

Name	Value	Description
`ENCRYPTED`	`1`	Encrypted without MITM protection (unauthenticated)
`AUTHENTICATED`	`2`	Encrypted with MITM protection (authenticated), although this level of security does not fully protect against passive eavesdroppers

TechnologyType

Type: uint32

Defined in fuchsia.bluetooth.sys/peer.fidl

Name	Value	Description
`LOW_ENERGY`	`1`
`CLASSIC`	`2`
`DUAL_MODE`	`3`

TABLES

BondingData

Represents the bonding data for a single peer.

Ordinal	Name	Type	Description
1	`identifier`	`fuchsia.bluetooth/PeerId`	The identifier that uniquely identifies this peer.
2	`local_address`	`fuchsia.bluetooth/Address`	The local Bluetooth identity address that this bond is associated with.
3	`name`	`string`	The name of the peer, if known.
4	`le`	`LeData`	Bonding data that is present when this peer is paired on the LE transport.
5	`bredr`	`BredrData`	Bonding data that is present when this peer is paired on the BR/EDR transport.
6	`address`	`fuchsia.bluetooth/Address`	The identity address of the peer.

BredrData

Ordinal	Name	Type	Description
1	`address`	`fuchsia.bluetooth/Address`	The public device address of the peer.
2	`role_preference`	`fuchsia.bluetooth/ConnectionRole`	The peer's preferred piconet role. This is determined by role switch procedures. Paging and connecting from a peer does not automatically set this flag. If absent, the peer has not expressed a preference.
3	`services`	`vector<fuchsia.bluetooth/Uuid>`	Known service UUIDs obtained from EIR data or SDP.
4	`link_key`	`PeerKey`	The semi-permanent BR/EDR key. Present if link was paired with Secure Simple Pairing or stronger.

HostData

Represents persistent local host data.

Ordinal Name Type Description

irk

LocalKey

The local Identity Resolving Key used by a bt-host device to generate Resolvable Private Addresses when privacy is enabled.

May be absent for hosts that do not use LE privacy, or that only use Non-Resolvable Private Addresses.

NOTE: This key is distributed to LE peers during pairing procedures. The client must take care to assign an IRK that consistent with the local bt-host identity.

HostInfo

Defined in fuchsia.bluetooth.sys/host_watcher.fidl

Information about a Bluetooth controller and its associated host-subsystem state.

Ordinal	Name	Type	Description
1	`id`	`fuchsia.bluetooth/HostId`	Uniquely identifies a host on the current system. This field is always present.
2	`technology`	`TechnologyType`	The Bluetooth technologies that are supported by this adapter. This field is always present.
3	`address`	`fuchsia.bluetooth/Address`	The identity address. This field is always present.
4	`active`	`bool`	Indicates whether or not this is the active host. The system has one active host which handles all Bluetooth procedures.
5	`local_name`	`string`	The local name of this host. This is the name that is visible to other devices when this host is in the discoverable mode.
6	`discoverable`	`bool`	Whether or not the local adapter is currently discoverable over BR/EDR and LE physical channels.
7	`discovering`	`bool`	Whether or not device discovery is currently being performed.

Identity

Represents the persistent configuration of a single host-subsystem instance. This is used for identity presentation (inquiry, inquiry response, and advertisement) and for bonding secrets recall (encrypting link data to peers associated with this identity).

Each BR/EDR BD_ADDR and Low Energy public identity address used to bond should have its own Identity instance containing corresponding peers.

Each Identity instance that supports LE privacy should have an Identity Resolving Key (IRK) that is consistent with that distributed to its bonded peers.

Ordinal	Name	Type	Description
1	`host`	`HostData`
2	`bonds`	`vector<BondingData>`	All bonds that use a public identity address must contain the same local address.

LeData

Ordinal	Name	Type	Description
1	`address`	`fuchsia.bluetooth/Address`	The identity address of the peer.
2	`connection_parameters`	`LeConnectionParameters`	The peer's preferred connection parameters, if known.
3	`services`	`vector<fuchsia.bluetooth/Uuid>`	Known GATT service UUIDs.
4	`ltk`	`Ltk`	The LE long-term key. Present if the link was encrypted. This field is superseded by the `peer_ltk` and `local_ltk` fields. It is invalid for the `ltk` field to be present simultaneously with the `peer_ltk` and `local_ltk` fields. In particular: LeData generated and notified by the Bluetooth system no longer populates this field. LeData supplied by a client of the Bluetooth system (e.g. Bootstrap) can continue to use this field but is encouraged to migrate to the new fields.
5	`irk`	`PeerKey`	Identity Resolving RemoteKey used to generate and resolve random addresses.
6	`csrk`	`PeerKey`	Connection Signature Resolving RemoteKey used for data signing without encryption.
7	`peer_ltk`	`Ltk`	LE long-term key used to encrypt a connection when the peer is in the LE Peripheral role. In legacy pairing (`peer_ltk.security.secure_connections` is false), this key corresponds to the key distributed by the peer. In Secure Connections pairing there is only one LTK and `peer_ltk` is the same as `local_ltk`.
8	`local_ltk`	`Ltk`	LE long-term key used to encrypt a connection when the peer is in the LE Central role. In legacy pairing (`local_ltk.security.secure_connections` is false), this key corresponds to the key distributed by the local device. In Secure Connections pairing there is only one LTK and `local_ltk` is the same as `peer_ltk`.

PairingOptions

Defined in fuchsia.bluetooth.sys/pairing_options.fidl

Parameters that give a caller more fine-grained control over the pairing process. All of the fields of this table are optional and pairing can still succeed if none of them are set.

Ordinal Name Type Description

le_security_level

PairingSecurityLevel

Only relevant for LE. If present, determines the Security Manager security level to pair with. If not present, defaults to PairingSecurityLevel.AUTHENTICATED.

bondable_mode

BondableMode

If transport is LOW_ENERGY or DUAL_MODE, whether the device should form a bond or not during pairing. If not present, the pairing will default to bondable mode.

If transport is CLASSIC, this option must be absent or otherwise the value BONDABLE. NON_BONDABLE mode is not currently supported for the CLASSIC transport

transport

TechnologyType

If transport is LOW_ENERGY, indicate a desire to pair over the LE transport. If transport is CLASSIC, indicate a desire to pair over the Br/Edr transport. If transport is DUAL_MODE, indicate a desire to pair over both transports. If absent, shall be interpreted as DUAL_MODE

Peer

Defined in fuchsia.bluetooth.sys/peer.fidl

Represents a remote BR/EDR, LE, or dual-mode BR/EDR/LE peer.

Ordinal	Name	Type	Description
1	`id`	`fuchsia.bluetooth/PeerId`	Uniquely identifies this peer on the current system. This field is always present.
2	`address`	`fuchsia.bluetooth/Address`	Bluetooth device address that identifies this peer. Clients should display this field to the user when `name` is not available. This field is always present. NOTE: Clients should use the `identifier` field to keep track of peers instead of their address.
3	`technology`	`TechnologyType`	The Bluetooth technologies that are supported by this peer. This field is always present.
4	`connected`	`bool`	Whether or not a BR/EDR and/or LE connection exists to this peer. This field is always present.
5	`bonded`	`bool`	Whether or not this peer is bonded. This field is always present.
6	`name`	`string`	The name of the peer, if known.
7	`appearance`	`fuchsia.bluetooth/Appearance`	The LE appearance property. Present if this peer supports LE and the appearance information was obtained over advertising and/or GATT.
8	`device_class`	`fuchsia.bluetooth/DeviceClass`	The class of device for this device, if known.
9	`rssi`	`int8`	The most recently obtained advertising signal strength for this peer. Present if known.
10	`tx_power`	`int8`	The most recently obtained transmission power for this peer. Present if known.
11	`services`	`vector<fuchsia.bluetooth/Uuid>`	The list of service UUIDs known to be available on this peer.

UNIONS

Access_Connect_Result

Name	Type	Description
`response`	`Access_Connect_Response`
`err`	`Error`

Access_Disconnect_Result

Name	Type	Description
`response`	`Access_Disconnect_Response`
`err`	`Error`

Access_Forget_Result

Name	Type	Description
`response`	`Access_Forget_Response`
`err`	`Error`

Access_MakeDiscoverable_Result

Name	Type	Description
`response`	`Access_MakeDiscoverable_Response`
`err`	`Error`

Access_Pair_Result

Name	Type	Description
`response`	`Access_Pair_Response`
`err`	`Error`

Access_StartDiscovery_Result

Name	Type	Description
`response`	`Access_StartDiscovery_Response`
`err`	`Error`

Bootstrap_Commit_Result