xref: /Zephyr-Core-3.5.0/subsys/bluetooth/host/Kconfig

# Bluetooth LE stack configuration options

# Copyright (c) 2016-2020 Nordic Semiconductor ASA
# Copyright (c) 2015-2016 Intel Corporation
# SPDX-License-Identifier: Apache-2.0

config BT_LONG_WQ
	bool "Dedicated workqueue for long-running tasks."
	default y if BT_GATT_CACHING
	help
	  Adds an API for a workqueue dedicated to long-running tasks.

if BT_LONG_WQ
config BT_LONG_WQ_STACK_SIZE
	# Hidden: Long workqueue stack size. Should be derived from system
	# requirements.
	int
	default 1300 if BT_GATT_CACHING
	default 1140 if BT_TINYCRYPT_ECC
	default 1024

config BT_LONG_WQ_PRIO
	int "Long workqueue priority. Should be pre-emptible."
	default 10
	range 0 NUM_PREEMPT_PRIORITIES

config BT_LONG_WQ_INIT_PRIO
	int "Long workqueue init priority"
	default 50
	help
	  Init priority level to setup the long workqueue.

endif # BT_LONG_WQ

config BT_HCI_HOST
	# Hidden option to make the conditions more intuitive
	bool
	default y
	depends on !BT_HCI_RAW
	select POLL


config BT_HCI_TX_STACK_SIZE
	# NOTE: This value is derived from other symbols and should only be
	# changed if required by architecture
	int
	prompt "HCI Tx thread stack size" if BT_HCI_TX_STACK_SIZE_WITH_PROMPT
	default 512 if BT_H4
	default 512 if BT_H5
	default 416 if BT_SPI
	default 940 if BT_CTLR && BT_LL_SW_SPLIT && (NO_OPTIMIZATIONS || BT_ISO_BROADCAST)
	default 1024 if BT_CTLR && BT_LL_SW_SPLIT && BT_CENTRAL
	default 768 if BT_CTLR && BT_LL_SW_SPLIT
	default 512 if BT_USERCHAN
	default 640 if BT_STM32_IPM
	default 1024 if BT_B91
	# Even if no driver is selected the following default is still
	# needed e.g. for unit tests. This default will also server as
	# the worst-case stack size if an out-of-tree controller is used.
	default 1024
	help
	  Stack size needed for executing bt_send with specified driver.
	  NOTE: This is an advanced setting and should not be changed unless
	  absolutely necessary.  To change this you must first select
	  BT_HCI_TX_STACK_SIZE_WITH_PROMPT.

config BT_HCI_TX_STACK_SIZE_WITH_PROMPT
	bool "Override HCI Tx thread stack size"

config BT_HCI_TX_PRIO
	# Hidden option for Co-Operative Tx thread priority
	int
	default 7

config BT_HCI_RESERVE
	int
	default 0 if BT_H4
	default 1 if BT_H5
	default 1 if BT_RPMSG
	default 1 if BT_SPI
	default 1 if BT_STM32_IPM
	default 1 if BT_USERCHAN
	default 1 if BT_ESP32
	default 0 if BT_B91
	# Even if no driver is selected the following default is still
	# needed e.g. for unit tests.
	default 0
	help
	  Headroom that the driver needs for sending and receiving buffers. Add a
	  new 'default' entry for each new driver.


choice BT_RECV_CONTEXT
	prompt "BT RX Thread Selection"
	default BT_RECV_BLOCKING if BT_LL_SW_SPLIT || BT_H4
	default BT_RECV_WORKQ_BT
	help
	  Selects in which context incoming low priority HCI packets are processed.
	  The host defines some events as high priority to avoid race conditions and deadlocks.
	  High priority events are always processed in the context of the caller of bt_recv()
	  or bt_recv_prio(). The choice will influence RAM usage and how fast incoming HCI
	  packets are processed.

config BT_RECV_BLOCKING
	bool "Process HCI packets in the context of bt_recv() and bt_recv_prio()"
	help
	  When this option is selected, the host will not have its own RX thread.
	  With this option it is the responsibility of the HCI driver to call
	  bt_recv_prio from a higher priority context than bt_recv() in order to avoid deadlocks.

config BT_RECV_WORKQ_SYS
	bool "Process low priority HCI packets in the system work queue"
	help
	  When this option is selected, the host will process incoming low priority HCI packets
	  in the system work queue. The HCI driver shall not call bt_recv_prio().
	  High priority HCI packets will processed in the context of the caller of bt_recv().
	  The application needs to ensure the system workqueue stack size (SYSTEM_WORKQUEUE_STACK_SIZE)
	  is large enough, refer to BT_RX_STACK_SIZE for the recommended minimum.
	  Note: When this option is used, other users of the system work queue will influence the
	  latency of incoming Bluetooth events.

config BT_RECV_WORKQ_BT
	bool "Process low priority HCI packets in the bluetooth-specific work queue"
	help
	  When this option is selected, the host will process incoming low priority HCI packets
	  in the bluetooth-specific work queue. The HCI driver shall not call bt_recv_prio().
	  High priority HCI packets will processed in the context of the caller of bt_recv().
	  The application needs to ensure the bluetooth-specific work queue size is large enough,
	  refer to BT_RX_STACK_SIZE for the recommended minimum.
endchoice

config BT_RX_STACK_SIZE
	int "Size of the receiving thread stack"
	default 768 if BT_HCI_RAW
	default 3092 if BT_MESH_GATT_CLIENT
	default 2600 if BT_MESH
	default 2048 if BT_AUDIO
	default 2200 if BT_SETTINGS
	default 1200
	help
	  Size of the receiving thread stack. This is the context from
	  which all event callbacks to the application occur. The
	  default value is sufficient for basic operation, but if the
	  application needs to do advanced things in its callbacks that
	  require extra stack space, this value can be increased to
	  accommodate for that.

config BT_RX_PRIO
	# Hidden option for Co-Operative Rx thread priority
	int
	default 8

config BT_DRIVER_RX_HIGH_PRIO
	# Hidden option for Co-Operative HCI driver RX thread priority
	int
	default 6

menu "Bluetooth Host"

if BT_HCI_HOST

rsource "../mesh/Kconfig"
rsource "../audio/Kconfig"

config BT_HOST_CRYPTO
	# Hidden option that compiles in AES encryption support using TinyCrypt
	# library if this is not provided by the controller implementation.
	bool
	default y if !BT_CTLR_CRYPTO
	select TINYCRYPT
	select TINYCRYPT_AES

config BT_HOST_CRYPTO_PRNG
	bool "Use Tinycrypt library for random number generation"
	default y
	select TINYCRYPT_SHA256
	select TINYCRYPT_SHA256_HMAC
	select TINYCRYPT_SHA256_HMAC_PRNG
	depends on BT_HOST_CRYPTO
	help
	  When selected, will use tinycrypt library for random number generation.
	  This will consume additional ram, but may speed up the generation of random
	  numbers.

	  Otherwise, random numbers will be generated through multiple HCI calls,
	  which will not consume additional resources, but may take a long time,
	  depending on the length of the random data.
	  This method is generally recommended within 16 bytes.

config BT_SETTINGS
	bool "Store Bluetooth state and configuration persistently"
	depends on SETTINGS
	select MPU_ALLOW_FLASH_WRITE if ARM_MPU
	help
	  When selected, the Bluetooth stack will take care of storing
	  (and restoring) the Bluetooth state (e.g. pairing keys) and
	  configuration persistently in flash.

	  When this option has been enabled, it's important that the
	  application makes a call to settings_load() after having done
	  all necessary initialization (e.g. calling bt_enable). The
	  reason settings_load() is handled externally to the stack, is
	  that there may be other subsystems using the settings API, in
	  which case it's more efficient to load all settings in one go,
	  instead of each subsystem doing it independently.

	  Warning: The Bluetooth host expects a settings backend that loads
	  settings items in handle order.

if BT_SETTINGS
config BT_SETTINGS_CCC_LAZY_LOADING
	bool "Load CCC values from settings when peer connects"
	depends on BT_CONN
	default y
	help
	  Load Client Configuration Characteristic setting right after a bonded
	  device connects.
	  Disabling this option will increase memory usage as CCC values for all
	  bonded devices will be loaded when calling settings_load.

config BT_SETTINGS_DELAYED_STORE
	# Enables delayed non-volatile storage mechanism
	bool
	help
	  Triggers the storage of the CF and CCC right after a write.
	  This is done in the workqueue context, in order to not block the BT RX
	  thread for too long.

config BT_SETTINGS_DELAYED_STORE_MS
	int
	default 1000
	help
	  (Advanced) Governs the timeout after which the settings write will
	  take effect.

config BT_SETTINGS_CCC_STORE_ON_WRITE
	bool "Store CCC value immediately after it has been written"
	depends on BT_CONN
	select BT_SETTINGS_DELAYED_STORE
	default y
	help
	  Store Client Configuration Characteristic value right after it has
	  been updated. If the option is disabled, the CCC is only stored on
	  disconnection.

config BT_SETTINGS_CF_STORE_ON_WRITE
	bool "Store CF value immediately after it has been written"
	depends on BT_CONN && BT_GATT_CACHING
	select BT_SETTINGS_DELAYED_STORE
	default y
	help
	  Store Client Supported Features value right after it has been updated.
	  If the option is disabled, the CF is only stored on disconnection.

config BT_SETTINGS_USE_PRINTK
	bool "Use snprintk to encode Bluetooth settings key strings"
	depends on SETTINGS && PRINTK
	default y
	help
	  When selected, Bluetooth settings will use snprintk to encode
	  key strings.
	  When not selected, Bluetooth settings will use a faster builtin
	  function to encode the key string. The drawback is that if
	  printk is enabled then the program memory footprint will be larger.
endif # BT_SETTINGS

config BT_FILTER_ACCEPT_LIST
	bool "Filter accept list support"
	help
	  This option enables the filter accept list API. This takes advantage of the
	  filtering feature of a BLE controller.
	  The filter accept list is a global list and the same list is used
	  by both scanner and advertiser. The filter accept list cannot be modified while
	  it is in use.

	  An Advertiser can filter which peers can connect or request scan
	  response data.
	  A scanner can filter advertisers for which it will generate
	  advertising reports.
	  Connections can be established automatically for accepted peers.

config BT_LIM_ADV_TIMEOUT
	int "Timeout for limited advertising in 1s units"
	default 30
	range 1 180
	depends on BT_BROADCASTER
	help
	  After this timeout is reached, advertisement with BT_LE_AD_LIMITED flag
	  set shall be terminated. As per BT Core Spec 5.2, Vol 3, Part C,
	  Appendix A (NORMATIVE): TIMERS AND CONSTANTS it's required to be no more
	  than 180s.

config BT_CONN_TX_USER_DATA_SIZE
	int
	default 16 if 64BIT
	default 8
	help
	  Necessary user_data size for allowing packet fragmentation when
	  sending over HCI. See `struct tx_meta` in conn.c.

if BT_CONN

config BT_CONN_TX_MAX
	int "Maximum number of pending TX buffers with a callback"
	default BT_L2CAP_TX_BUF_COUNT
	range BT_L2CAP_TX_BUF_COUNT 255
	help
	  Maximum number of pending TX buffers that have an associated
	  callback. Normally this can be left to the default value, which
	  is equal to the number of TX buffers in the stack-internal pool.

config BT_CONN_PARAM_ANY
	bool "Accept any values for connection parameters"
	help
	  Some controllers support additional connection parameter ranges
	  beyond what is described in the specification. Enabling this option
	  allows the application to set any value to all connection parameters.
	  Tbe Host will perform no limits nor consistency checks on any of the
	  connection parameters (conn interval min and max, latency and timeout).
	  However, the Host will still use numerical comparisons between the
	  min and max connection intervals in order to verify whether the
	  desired parameters have been established in the connection.

config BT_USER_PHY_UPDATE
	bool "User control of PHY Update Procedure"
	depends on BT_PHY_UPDATE
	help
	  Enable application access to initiate the PHY Update Procedure.
	  The application can also register a callback to be notified about PHY
	  changes on the connection. The current PHY info is available in the
	  connection info.

config BT_AUTO_PHY_UPDATE
	bool "Auto-initiate PHY Update Procedure"
	depends on BT_PHY_UPDATE
	default y if !BT_USER_PHY_UPDATE
	help
	  Initiate PHY Update Procedure on connection establishment.

	  Disable this if you want the PHY Update Procedure feature supported
	  but want to rely on the remote device to initiate the procedure at its
	  discretion or want to initiate manually.

config BT_USER_DATA_LEN_UPDATE
	bool "User control of Data Length Update Procedure"
	depends on BT_DATA_LEN_UPDATE
	help
	  Enable application access to initiate the Data Length Update
	  Procedure. The application can also a register callback to be notified
	  about Data Length changes on the connection. The current Data Length
	  info is available in the connection info.

config BT_AUTO_DATA_LEN_UPDATE
	bool "Auto-initiate Data Length Update procedure"
	depends on BT_DATA_LEN_UPDATE
	default y if !BT_USER_DATA_LEN_UPDATE
	help
	  Initiate Data Length Update Procedure on connection establishment.

	  Disable this if you want the Data Length Update Procedure feature
	  supported but want to rely on the remote device to initiate the
	  procedure at its discretion or want to initiate manually.

config BT_REMOTE_INFO
	bool "Application access to remote information"
	help
	  Enable application access to the remote information available in the
	  stack. The remote information is retrieved once a connection has been
	  established and the application will be notified when this information
	  is available through the remote_info_available connection callback.

config BT_SMP
	bool "Security Manager Protocol support"
	select BT_CRYPTO
	select BT_RPA
	select BT_ECC
	help
	  This option enables support for the Security Manager Protocol
	  (SMP), making it possible to pair devices over LE.

if BT_SMP
config BT_PASSKEY_KEYPRESS
	bool "Passkey Keypress Notification support [EXPERIMENTAL]"
	select EXPERIMENTAL
	help
	  Enable support for receiving and sending Keypress Notifications during
	  Passkey Entry during pairing.

config BT_PRIVACY
	bool "Device privacy"
	help
	  Enable privacy for the local device. This makes the device use Resolvable
	  Private Addresses (RPAs) by default.

	  Note:
	  Establishing connections as a directed advertiser, or to a directed
	  advertiser is only possible if the controller also supports privacy.

config BT_PRIVACY_RANDOMIZE_IR
	bool "Randomize identity root for fallback identities"
	depends on BT_PRIVACY
	select BT_SETTINGS
	help
	  Enabling this option will cause the Host to ignore controller-provided
	  identity roots (IR). The Host will instead use bt_rand to generate
	  identity resolving keys (IRK) and store them in the settings subsystem.

	  Setting this config may come with a performance penalty to boot time,
	  as the hardware RNG may need time to generate entropy and will block
	  Bluetooth initialization.

	  This option increases privacy, as explained in the following text.

	  The IR determines the IRK of the identity. The IRK is used to both
	  generate and resolve (recognize) the private addresses of an identity.
	  The IRK is a shared secret, distributed to peers bonded to that
	  identity.

	  An attacker that has stolen or once bonded and retained the IRK can
	  forever resolve addresses from that IRK, even if that bond has been
	  deleted locally.

	  Deleting an identity should ideally delete the IRK as well and thereby
	  restore anonymity from previously bonded peers. But unless this config
	  is set, this does not always happen.

	  In particular, a factory reset function that wipes the data in the
	  settings subsystem may not affect the controller-provided IRs. If
	  those IRs are reused, this device can be tracked across factory resets.

	  For optimal privacy, a new IRK (i.e., identity) should be used per
	  bond. However, this naturally limits advertisements from that identity
	  to be recognizable by only that one bonded device.

	  A description of the exact effect of this setting follows.

	  If the application has not setup an identity before calling
	  settings_load()/settings_load_subtree("bt") after bt_enable(), the
	  Host will automatically try to load saved identities from the settings
	  subsystem, and if there are none, set up the default identity
	  (BT_ID_DEFAULT).

	  If the controller has a public address (HCI_Read_BD_ADDR), that becomes
	  the address of the default identity. The Host will by default try to
	  obtain the IR for that identity from the controller (by Zephyr HCI
	  Read_Key_Hierarchy_Roots). Setting this config randomizes the IR
	  instead.

	  If the controller does not have a public address, the Host will try
	  to source the default identity from the static address information
	  from controller (Zephyr HCI Read_Static_Addresses). This results in an
	  identity for each entry in Read_Static_Addresses. Setting this config
	  randomizes the IRs during this process.

config BT_RPA_TIMEOUT
	int "Resolvable Private Address timeout"
	depends on BT_PRIVACY
	default 900
	range 1 65535
	help
	  This option defines how often resolvable private address is rotated.
	  Value is provided in seconds and defaults to 900 seconds (15 minutes).

config BT_RPA_TIMEOUT_DYNAMIC
	bool "Support setting the Resolvable Private Address timeout at runtime"
	depends on BT_PRIVACY
	help
	  This option allows the user to override the default value of
	  the Resolvable Private Address timeout using dedicated APIs.

config BT_SIGNING
	bool "Data signing support"
	help
	  This option enables data signing which is used for transferring
	  authenticated data in an unencrypted connection.

config BT_SMP_APP_PAIRING_ACCEPT
	bool "Accept or reject pairing initiative"
	help
	  When receiving pairing request or pairing response query the
	  application whether to accept to proceed with pairing or not. This is
	  for pairing over SMP and does not affect SSP, which will continue
	  pairing without querying the application.
	  The application can return an error code, which is translated into
	  a SMP return value if the pairing is not allowed.

config BT_SMP_SC_PAIR_ONLY
	bool "Disable legacy pairing"
	help
	  This option disables LE legacy pairing and forces LE secure connection
	  pairing. All Security Mode 1 levels can be used with legacy pairing
	  disabled, but pairing with devices that do not support secure
	  connections pairing will not be supported.
	  To force a higher security level use "Secure Connections Only Mode"

config BT_SMP_SC_ONLY
	bool "Secure Connections Only Mode"
	select BT_SMP_SC_PAIR_ONLY
	help
	  This option enables support for Secure Connection Only Mode. In this
	  mode device shall only use Security Mode 1 Level 4 with exception
	  for services that only require Security Mode 1 Level 1 (no security).
	  Security Mode 1 Level 4 stands for authenticated LE Secure Connections
	  pairing with encryption. Enabling this option disables legacy pairing.

config BT_SMP_OOB_LEGACY_PAIR_ONLY
	bool "Force Out Of Band Legacy pairing"
	depends on !(BT_SMP_SC_PAIR_ONLY || BT_SMP_SC_ONLY)
	help
	  This option disables Legacy and LE SC pairing and forces legacy OOB.

config BT_SMP_DISABLE_LEGACY_JW_PASSKEY
	bool "Forbid usage of insecure legacy pairing methods"
	depends on !(BT_SMP_SC_PAIR_ONLY || BT_SMP_SC_ONLY || \
		     BT_SMP_OOB_LEGACY_PAIR_ONLY)
	help
	  This option disables Just Works and Passkey legacy pairing methods to
	  increase security.

config BT_SMP_ALLOW_UNAUTH_OVERWRITE
	bool "Allow unauthenticated pairing for paired device"
	help
	  This option allows all unauthenticated pairing attempts made by the
	  peer where an unauthenticated bond already exists.
	  This would enable cases where an attacker could copy the peer device
	  address to connect and start an unauthenticated pairing procedure
	  to replace the existing bond. When this option is disabled in order
	  to create a new bond the old bond has to be explicitly deleted with
	  bt_unpair.

config BT_ID_UNPAIR_MATCHING_BONDS
	bool "Delete bond with same peer with other local identity when bonding"
	help
	  When a bond is about to complete, find any other bond with the same
	  peer address (or IRK) and `bt_unpair` that bond before the event
	  `pairing_complete`.

	  Important: If this option is not enabled, the current implementation
	  will automatically fail the bonding. See "RL limitation" below.

	  Important: If this option is not enabled, as Peripheral, it may be too
	  late to abort the bonding. The pairing is failed locally, but it may
	  still be reported as successful on the Central. When this situation
	  occurs, the Zephyr Peripheral will immediately disconnect. See "SMP
	  limitation" below.

	  [RL limitation]:
	  The Host implementors have considered it unlikely that applications
	  would ever want to have multiple bonds with the same peer. The
	  implementors prioritize the simplicity of the implementation over this
	  capability.

	  The Resolve List on a Controller is not able to accommodate multiple
	  local addresses/IRKs for a single remote address. This would prevent
	  the Host from setting up a one-to-one correspondence between the Host
	  bond database and the Controller Resolve List. The implementation
	  relies on that capability when using the Resolve List. For performance
	  reasons, there is the wish to not fallback to Host Address Resolution
	  in this case.

	  [SMP Limitation]:
	  The Paring Failed command of the Security Manager Protocol cannot be
	  sent outside of a Pairing Process. A Pairing Process ends when the
	  last Transport Specific Key to be distributed is acknowledged at
	  link-layer. The Host does not have control over this acknowledgment,
	  and the order of distribution is fixed by the specification.

config BT_ID_ALLOW_UNAUTH_OVERWRITE
	bool "Allow unauthenticated pairing with same peer with other local identity"
	depends on !BT_SMP_ALLOW_UNAUTH_OVERWRITE
	help
	  This option allows unauthenticated pairing attempts made by the
	  peer where an unauthenticated bond already exists on other local
	  identity. This configuration still blocks unauthenticated pairing
	  attempts on the same local identity. To allow the pairing procedure
	  unconditionally, please see the BT_SMP_ALLOW_UNAUTH_OVERWRITE
	  configuration.

config BT_SMP_USB_HCI_CTLR_WORKAROUND
	bool "Workaround for USB HCI controller out-of-order events"
	depends on BT_TESTING
	help
	  This option enables support for USB HCI controllers that sometimes
	  send out-of-order HCI events and ACL Data due to using different USB
	  endpoints.
	  Enabling this option will make the central role not require the
	  encryption-change event to be received before accepting key-distribution
	  data.
	  It opens up for a potential vulnerability as the central cannot detect
	  if the keys are distributed over an encrypted link.

config BT_FIXED_PASSKEY
	bool "Use a fixed passkey for pairing"
	help
	  With this option enabled, the application will be able to call the
	  bt_passkey_set() API to set a fixed passkey. If set, the
	  pairing_confirm() callback will be called for all incoming pairings.

config BT_USE_DEBUG_KEYS
	bool "Security Manager Debug Mode"
	help
	  This option places Security Manager in a Debug Mode. In this mode
	  predefined Diffie-Hellman private/public key pair is used as described
	  in Core Specification Vol. 3, Part H, 2.3.5.6.1.

	  WARNING: This option enables anyone to decrypt on-air traffic.
	  Use of this feature in production is strongly discouraged.

config BT_BONDABLE
	bool "Bondable Mode"
	default y
	help
	  This option enables support for Bondable Mode. In this mode,
	  Bonding flag in AuthReq of SMP Pairing Request/Response will be set
	  indicating the support for this mode.

config BT_BONDING_REQUIRED
	bool "Always require bonding"
	depends on BT_BONDABLE
	help
	  When this option is enabled remote devices are required to always
	  set the bondable flag in their pairing request. Any other kind of
	  requests will be rejected.

config BT_BONDABLE_PER_CONNECTION
	bool "Set/clear the bonding flag per-connection [EXPERIMENTAL]"
	select EXPERIMENTAL
	help
	  Enable support for the bt_conn_set_bondable API function that is
	  used to set/clear the bonding flag on a per-connection basis.

config BT_STORE_DEBUG_KEYS
	bool "Store Debug Mode bonds"
	help
	  This option enables support for storing bonds where either of devices
	  is using the predefined Diffie-Hellman private/public key pair as
	  described in the Core Specification Vol 3, Part H, 2.3.5.6.1.

	  WARNING: This option potentially enables anyone to decrypt on-air
	  traffic.
	  Use of this feature in production is strongly discouraged.

config BT_SMP_ENFORCE_MITM
	bool "Enforce MITM protection"
	default y
	help
	  With this option enabled, the Security Manager will set MITM option in
	  the Authentication Requirements Flags whenever local IO Capabilities
	  allow the generated key to be authenticated.

config BT_OOB_DATA_FIXED
	bool "Use a fixed random number for LESC OOB pairing"
	depends on BT_TESTING
	help
	  With this option enabled, the application will be able to perform LESC
	  pairing with OOB data that consists of fixed random number and confirm
	  value.

	  WARNING: This option stores a hardcoded Out-of-Band value in the image.
	  Use of this feature in production is strongly discouraged.

config BT_KEYS_OVERWRITE_OLDEST
	bool "Overwrite the oldest key if key storage is full"
	help
	  If a pairing attempt occurs and the key storage is full then the
	  oldest key from the set of not currently in use keys will be selected
	  and overwritten by the pairing device.

config BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING
	bool "Store aging counter every time a successful paring occurs"
	depends on BT_SETTINGS && BT_KEYS_OVERWRITE_OLDEST
	help
	  With this option enabled, aging counter will be stored in settings every
	  time a successful pairing occurs. This increases flash wear out but offers
	  a more correct finding of the oldest unused pairing info.

config BT_SMP_MIN_ENC_KEY_SIZE
	int
	prompt "Minimum encryption key size accepted in octets" if !BT_SMP_SC_ONLY
	range 7 16
	default 16 if BT_SMP_SC_ONLY
	default 7
	help
	  This option sets the minimum encryption key size accepted during pairing.

endif # BT_SMP

rsource "Kconfig.l2cap"
rsource "Kconfig.gatt"
rsource "../services/Kconfig"

config BT_MAX_PAIRED
	int "Maximum number of paired devices"
	default 0 if !BT_SMP
	default 1
	range 0 128
	help
	  Maximum number of paired Bluetooth devices. The minimum (and
	  default) number is 1.

config BT_CREATE_CONN_TIMEOUT
	int "Timeout for pending LE Create Connection command in seconds"
	default 3
	range 1 BT_RPA_TIMEOUT if BT_PRIVACY && (BT_RPA_TIMEOUT < 655)
	range 1 655

config BT_CONN_PARAM_UPDATE_TIMEOUT
	int "Peripheral connection parameter update timeout in milliseconds"
	default 5000
	range 0 65535
	help
	  The value is a timeout used by peripheral device to wait until it
	  starts the first connection parameters update procedure after a
	  connection has been established.
	  The connection parameters requested will be the parameters set by the
	  application, or the peripheral preferred connection parameters if
	  configured.
	  The default value is set to 5 seconds, to comply with the Bluetooth
	  Core specification: Core 4.2 Vol 3, Part C, 9.3.12.2:
	  "The Peripheral device should not perform a Connection Parameter
	  Update procedure within 5 seconds after establishing a connection."

config BT_CONN_PARAM_RETRY_COUNT
	int "Peripheral connection parameter update retry attempts"
	default 3
	range 0 255
	help
	  This value corresponds to number of times to retry connection
	  parameter update to attain the preferred value set in GATT
	  characteristics in the Peripheral.

config BT_CONN_PARAM_RETRY_TIMEOUT
	int "Peripheral connection parameter update retry timeout in milliseconds"
	default 5000
	range 0 65535
	help
	  The value is a timeout used by peripheral device to wait until retry
	  to attempt requesting again the preferred connection parameters.

endif # BT_CONN

if BT_OBSERVER
config BT_BACKGROUND_SCAN_INTERVAL
	int "Scan interval used for background scanning in 0.625 ms units"
	default 2048
	range 4 16384
config BT_BACKGROUND_SCAN_WINDOW
	int "Scan window used for background scanning in 0.625 ms units"
	default 18
	range 4 16384

config BT_EXT_SCAN_BUF_SIZE
	int "Maximum advertisement report size"
	depends on BT_EXT_ADV
	range 1 1650
	default 229
	help
	  Maximum size of an advertisement report in octets. If the advertisement
	  provided by the controller is larger than this buffer size,
	  the remaining data will be discarded.

endif # BT_OBSERVER

config BT_SCAN_WITH_IDENTITY
	bool "Perform active scanning using local identity address"
	depends on !BT_PRIVACY && (BT_CENTRAL || BT_OBSERVER)
	help
	  Enable this if you want to perform active scanning using the local
	  identity address as the scanner address. By default the stack will
	  always use a non-resolvable private address (NRPA) in order to avoid
	  disclosing local identity information. By not scanning with the
	  identity address the scanner will receive directed advertise reports
	  for for the local identity. If this use case is required, then enable
	  this option.

config BT_DEVICE_NAME_DYNAMIC
	bool "Allow to set Bluetooth device name on runtime"
	help
	  Enabling this option allows for runtime configuration of Bluetooth
	  device name.

config BT_DEVICE_NAME_MAX
	int "Maximum size in bytes for device name"
	depends on BT_DEVICE_NAME_DYNAMIC
	default 28
	range 2 248
	help
	  Bluetooth device name storage size. Storage can be up to 248 bytes
	  long (excluding NULL termination).

config BT_DEVICE_NAME
	string "Bluetooth device name"
	default "Zephyr"
	help
	  Bluetooth device name. Name can be up to 248 bytes long (excluding
	  NULL termination). Can be empty string.

config BT_DEVICE_APPEARANCE_DYNAMIC
	bool "Runtime Bluetooth Appearance changing"
	help
	  Enables use of bt_set_appearance.
	  If CONFIG_BT_SETTINGS is set, the appearance is persistently stored.

config BT_DEVICE_APPEARANCE_GATT_WRITABLE
	bool "Allow authenticated peers to set GAP Appearance"
	depends on BT_DEVICE_APPEARANCE_DYNAMIC

config BT_DEVICE_APPEARANCE
	int "Bluetooth device appearance"
	range 0 65535
	default 0
	help
	  Bluetooth device appearance. For the list of possible values please
	  consult the following link:
	  https://www.bluetooth.com/specifications/assigned-numbers

config BT_ID_MAX
	int "Maximum number of local identities"
	range 1 250
	default 1
	help
	  Maximum number of supported local identity addresses. For most
	  products this is safe to leave as the default value (1).

config BT_DF
	bool "Direction Finding support [EXPERIMENTAL]"
	depends on !BT_CTLR || BT_CTLR_DF_SUPPORT
	select EXPERIMENTAL
	help
	  Enable support for Bluetooth 5.1 Direction Finding.
	  It will allow to: get information about antennae, configure
	  Constant Tone Extension, transmit CTE and sample incoming CTE.

if BT_DF

config BT_DF_CONNECTIONLESS_CTE_RX
	bool "Support for receive of CTE in connectionless mode"
	depends on !BT_CTLR || BT_CTLR_DF_CTE_RX_SUPPORT
	help
	  Enable support for reception and sampling of Constant Tone Extension
	  in connectionless mode.

config BT_DF_CONNECTIONLESS_CTE_TX
	bool "Support for transmission of CTE in connectionless mode"
	depends on !BT_CTLR || BT_CTLR_DF_CTE_TX_SUPPORT
	help
	  Enable support for transmission of Constant Tone Extension in
	  connectionless mode.

config BT_DF_CONNECTION_CTE_RX
	bool "Support for receive of CTE in connection mode"
	depends on !BT_CTLR || BT_CTLR_DF_CTE_RX_SUPPORT
	help
	  Enable support for reception and sampling of Constant Tone Extension
	  in connection mode.

config BT_DF_CONNECTION_CTE_TX
	bool "Support for transmission of CTE in connection mode"
	depends on !BT_CTLR || BT_CTLR_DF_CTE_TX_SUPPORT
	help
	  Enable support for transmission of Constant Tone Extension in
	  connection mode.

config BT_DF_CONNECTION_CTE_REQ
	bool "Support for CTE request procedure in connection mode"
	depends on BT_DF_CONNECTION_CTE_RX
	help
	  Enable support for request of Constant Tone Extension in connection
	  mode.

config BT_DF_CONNECTION_CTE_RSP
	bool "Support for CTE request procedure in connection mode"
	depends on BT_DF_CONNECTION_CTE_TX
	help
	  Enable support for request of Constant Tone Extension in connection
	  mode.

config BT_DF_CTE_RX_AOA
	bool "Antenna switching during CTE reception (AoA) feature"
	depends on BT_DF_CONNECTIONLESS_CTE_RX || BT_DF_CONNECTION_CTE_RX
	default y
	help
	  Enable support for antenna switching during CTE reception.
	  Also known as Angle of Arrival mode.

config BT_DF_CTE_TX_AOD
	bool "Antenna switching during CTE transmission (AoD) feature"
	depends on BT_DF_CONNECTIONLESS_CTE_TX || BT_DF_CONNECTION_CTE_TX
	default y
	help
	  Enable support for antenna switching during CTE transmission.
	  Also known as Angle of Departure mode.

config BT_DF_VS_CL_IQ_REPORT_16_BITS_IQ_SAMPLES
	bool "Use 16 bits signed integer IQ samples in connectionless IQ reports"
	depends on BT_DF_CONNECTIONLESS_CTE_RX && BT_HCI_VS_EXT
	select BT_HCI_VS_EVT
	help
	  Direction Finging connectionless IQ reports provide a set of IQ samples collected during
	  sampling of CTE. Bluetooth 5.3 Core Specification defines IQ samples to be 8 bits signed
	  integer, see Vol 4, Part E section 7.7.65.21. This option enables a vendor specific Host
	  extenstion to handle connectionless IQ reports with samples that are in 16 bit signed
	  integer format.

config BT_DF_VS_CONN_IQ_REPORT_16_BITS_IQ_SAMPLES
	bool "Use 16 bits signed integer IQ samples in connection IQ reports"
	depends on BT_DF_CONNECTION_CTE_RX && BT_HCI_VS_EXT
	select BT_HCI_VS_EVT
	help
	  Direction Finging connection IQ reports provide a set of IQ samples collected during
	  sampling of CTE. Bluetooth 5.3 Core Specification defines IQ samples to be 8 bits signed
	  integer, see Vol 4, Part E sections 7.7.65.22. This option enables a vendor specific Host
	  extenstion to handle connection IQ report with samples that are in 16 bit signed integer
	  format.

endif # BT_DF
endif # BT_HCI_HOST

config BT_ECC
	bool "ECDH key generation support"
	default y if BT_SMP && !BT_SMP_OOB_LEGACY_PAIR_ONLY
	help
	  This option adds support for ECDH HCI commands.

config BT_TINYCRYPT_ECC
	bool "Emulate ECDH in the Host using TinyCrypt library"
	select TINYCRYPT
	select TINYCRYPT_ECC_DH
	select BT_LONG_WQ
	depends on BT_ECC && (BT_HCI_RAW || BT_HCI_HOST)
	default y if BT_CTLR && !BT_CTLR_ECDH
	help
	  If this option is set TinyCrypt library is used for emulating the
	  ECDH HCI commands and events needed by e.g. LE Secure Connections.
	  In builds including the BLE Host, if not set the controller crypto is
	  used for ECDH and if the controller doesn't support the required HCI
	  commands the LE Secure Connections support will be disabled.
	  In builds including the HCI Raw interface and the BLE Controller, this
	  option injects support for the 2 HCI commands required for LE Secure
	  Connections so that Hosts can make use of those. The option defaults
	  to enabled for a combined build with Zephyr's own controller, since it
	  does not have any special ECC support itself (at least not currently).

config BT_HOST_CCM
	bool "Host side AES-CCM module"
	help
	  Enables the software based AES-CCM engine in the host. Will use the
	  controller's AES encryption functions if available, or BT_HOST_CRYPTO
	  otherwise.

config BT_PER_ADV_SYNC_BUF_SIZE
	int "Maximum periodic advertising report size"
	depends on BT_PER_ADV_SYNC
	range 0 1650
	default 0
	help
	  Maximum size of a fragmented periodic advertising report. If the periodic
	  advertising report provided by the controller is fragmented and larger
	  than this buffer size, then the data will be discarded.
	  Unfragmented reports are forwarded as they are received.

config BT_DEBUG_ISO_DATA
	bool "ISO channel data debug"
	depends on BT_ISO_LOG_LEVEL_DBG
	help
	  Use this option to enable ISO channels data debug logs for the
	  Bluetooth Audio functionality. This will enable debug logs for all
	  ISO data received and sent.

config BT_SMP_SELFTEST
	bool "Bluetooth SMP self tests executed on init"
	depends on BT_SMP_LOG_LEVEL_DBG
	help
	  This option enables SMP self-tests executed on startup
	  to verify security and crypto functions.

config BT_SMP_FORCE_BREDR
	bool "Force Bluetooth SMP over BR/EDR"
	depends on BT_SMP_LOG_LEVEL_DBG
	help
	  This option enables SMP over BR/EDR even if controller is not
	  supporting BR/EDR Secure Connections. This option is solely for
	  testing and should never be enabled on production devices.

config BT_LOG_SNIFFER_INFO
	bool "Bluetooth log information for sniffer"
	help
	  This option enables the Bluetooth stack to log information such as
	  DH private key and LTK keys, which can be used by sniffers to decrypt
	  the connection without the use of Debug keys.

	  WARNING: This option prints out private security keys such as
	  the Long Term Key.
	  Use of this feature in production is strongly discouraged

config BT_TESTING
	bool "Bluetooth Testing"
	help
	  This option enables custom Bluetooth testing interface.
	  Shall only be used for testing purposes.

config BT_CONN_DISABLE_SECURITY
	bool "Disable security"
	depends on BT_TESTING
	help
	  This option disables security checks for incoming requests enabling
	  to test accessing GATT attributes and L2CAP channels that would
	  otherwise require encryption/authentication in order to be accessed.

	  WARNING: This option enables anyone to snoop on-air traffic.
	  Use of this feature in production is strongly discouraged.

config BT_BREDR
	bool "Bluetooth BR/EDR support [EXPERIMENTAL]"
	depends on BT_HCI_HOST
	select BT_PERIPHERAL
	select BT_CENTRAL
	select BT_SMP
	select BT_L2CAP_DYNAMIC_CHANNEL
	select EXPERIMENTAL
	help
	  This option enables Bluetooth BR/EDR support

if BT_BREDR
config BT_MAX_SCO_CONN
	int "Maximum number of simultaneous SCO connections"
	default 1
	range 1 3
	help
	  Maximum number of simultaneous Bluetooth synchronous connections
	  supported. The minimum (and default) number is 1.

config BT_RFCOMM
	bool "Bluetooth RFCOMM protocol support [EXPERIMENTAL]"
	select EXPERIMENTAL
	help
	  This option enables Bluetooth RFCOMM support

config BT_RFCOMM_L2CAP_MTU
	int "L2CAP MTU for RFCOMM frames"
	depends on BT_RFCOMM
	# RX MTU will be truncated to account for the L2CAP PDU header.
	default BT_BUF_ACL_RX_SIZE
	range 23 32767
	help
	  Maximum size of L2CAP PDU for RFCOMM frames.

config BT_HFP_HF
	bool "Bluetooth Handsfree profile HF Role support [EXPERIMENTAL]"
	depends on PRINTK
	select BT_RFCOMM
	select EXPERIMENTAL
	help
	  This option enables Bluetooth HF support

config BT_AVDTP
	bool "Bluetooth AVDTP protocol support [EXPERIMENTAL]"
	select EXPERIMENTAL
	help
	  This option enables Bluetooth AVDTP support

config BT_A2DP
	bool "Bluetooth A2DP Profile [EXPERIMENTAL]"
	select BT_AVDTP
	select EXPERIMENTAL
	help
	  This option enables the A2DP profile

config BT_PAGE_TIMEOUT
	hex "Bluetooth Page Timeout"
	default 0x2000
	range 0x0001 0xffff
	help
	  This option sets the page timeout value. Value is selected as
	  (N * 0.625) ms.

endif # BT_BREDR

config BT_HCI_VS_EVT_USER
	bool "User Vendor-Specific event handling"
	help
	  Enable registering a callback for delegating to the user the handling of
	  VS events that are not known to the stack

endmenu