# Bluetooth LE stack configuration options # Copyright (c) 2016-2020 Nordic Semiconductor ASA # Copyright (c) 2015-2016 Intel Corporation # SPDX-License-Identifier: Apache-2.0 comment "Host Stack Configuration" 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 default 1024 if BT_CTLR && BT_LL_SW_SPLIT && BT_CENTRAL default 640 if BT_CTLR && BT_LL_SW_SPLIT default 512 if BT_USERCHAN default 640 if BT_STM32_IPM # 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_ECC_STACK_SIZE # NOTE: This value is derived from other symbols and should only be # changed if required by architecture int "HCI ECC thread stack size" default 1140 help NOTE: This is an advanced setting and should not be changed unless absolutely necessary 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 # 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. config BT_RECV_IS_RX_THREAD # Hidden option set by the HCI driver to indicate that there's # no need for the host to have its own RX thread. # If this option has been enabled it is then the responsibility of the # HCI driver to call bt_recv_prio from a higher priority context than # bt_recv in order to avoid deadlocks. # If this option is disabled then only bt_recv should be called. bool prompt "bt_recv is called from RX thread" if BT_NO_DRIVER config BT_RX_STACK_SIZE int "Size of the receiving thread stack" depends on BT_HCI_HOST || BT_RECV_IS_RX_THREAD default 512 if BT_HCI_RAW default 2048 if BT_MESH default 2200 if BT_SETTINGS default 1024 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 depends on BT_HCI_HOST || BT_RECV_IS_RX_THREAD default 8 config BT_DRIVER_RX_HIGH_PRIO # Hidden option for Co-Operative HCI driver RX thread priority int default 6 if BT_HCI_HOST config BT_HOST_CRYPTO # Hidden option that compiles in random number generation and 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 select TINYCRYPT_SHA256 select TINYCRYPT_SHA256_HMAC select TINYCRYPT_SHA256_HMAC_PRNG 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. 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_CCC_STORE_ON_WRITE bool "Store CCC value immediately after it has been written" depends on BT_CONN help Store Client Configuration Characteristic value right after it has been updated. By default, CCC is only stored on disconnection. Choosing this option is safer for battery-powered devices or devices that expect to be reset suddenly. However, it requires additional workqueue stack space. 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_WHITELIST bool "DEPRECATED: Use BT_FILTER_ACCEPT_LIST instead" select BT_FILTER_ACCEPT_LIST config BT_FILTER_ACCEPT_LIST bool "Enable filter accept list support" help This option enables the filter accep 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. This options deprecates the bt_le_set_auto_conn API in favor of the bt_conn_create_aute_le API. 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_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 "Enable 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_version_available connection callback. config BT_REMOTE_VERSION bool "Enable remote version information" depends on BT_REMOTE_INFO help Enable this to get access to the remote version through the remote_version_available callback. The host will automatically ask the remote device after the connection has been established. config BT_SMP bool "Security Manager Protocol support" select TINYCRYPT select TINYCRYPT_AES select TINYCRYPT_AES_CMAC 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_PRIVACY bool "Privacy Feature" help Enable local Privacy Feature support. This makes it possible to use Resolvable Private Addresses (RPAs). 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_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_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_confim() callback will be called for all incoming pairings. config BT_USE_DEBUG_KEYS bool "Enable 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_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 7 default 16 if BT_SMP_SC_ONLY help This option sets the minimum encryption key size accepted during pairing. endif # BT_SMP rsource "Kconfig.l2cap" rsource "Kconfig.gatt" 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." 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 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 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 64 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 "Enable Direction Finding support [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. config BT_DF_CONNECTIONLESS_CTE_RX bool "Enable support for receive of CTE in connectionless mode" depends on BT_DF help Enable support for reception and sampling of Constant Tone Extension in connectionless mode. config BT_DF_CONNECTION_CTE_RX bool "Enable support for receive of CTE in connection mode" depends on BT_DF help Enable support for reception and sampling of Constant Tone Extension in connection mode. config BT_DEBUG_DF bool "Bluetooth Direction Finding debug" depends on BT_DF help This option enables debug support for Bluetooth Direction Finding endif # BT_HCI_HOST config BT_ECC bool "Enable ECDH key generation support" default y if BT_MESH_PROV || (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 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 "Enable 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. if BT_DEBUG config BT_DEBUG_SETTINGS bool "Bluetooth storage debug" depends on BT_SETTINGS help This option enables debug support for Bluetooth storage. config BT_DEBUG_HCI_CORE bool "Bluetooth HCI core debug" help This option enables debug support for Bluetooth HCI core. config BT_DEBUG_CONN bool "Bluetooth connection debug" depends on BT_CONN || BT_ISO help This option enables debug support for Bluetooth connection handling. config BT_DEBUG_ISO bool "ISO channel debug" help Use this option to enable ISO channels debug logs for the Bluetooth Audio functionality. config BT_DEBUG_KEYS bool "Bluetooth security keys debug" depends on BT_HCI_HOST depends on BT_SMP help This option enables debug support for the handling of Bluetooth security 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_DEBUG_SMP bool "Bluetooth Security Manager Protocol (SMP) debug" depends on BT_HCI_HOST depends on BT_SMP help This option enables debug support for the Bluetooth Security Manager Protocol (SMP). 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_SMP_SELFTEST bool "Bluetooth SMP self tests executed on init" depends on BT_DEBUG_SMP 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_DEBUG_SMP 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_DEBUG_RFCOMM bool "Bluetooth RFCOMM debug" depends on BT_RFCOMM help This option enables debug support for the Bluetooth RFCOMM layer. config BT_DEBUG_HFP_HF bool "Bluetooth Hands Free Profile (HFP) debug" depends on BT_HFP_HF help This option enables debug support for the Bluetooth Hands Free Profile (HFP). config BT_DEBUG_AVDTP bool "Bluetooth AVDTP debug" depends on BT_AVDTP help This option enables debug support for the Bluetooth AVDTP. config BT_DEBUG_A2DP bool "Bluetooth A2DP debug" depends on BT_A2DP help This option enables debug support for the Bluetooth A2DP profile. config BT_DEBUG_SDP bool "Bluetooth Service Discovery Protocol (SDP) debug" depends on BT_BREDR help This option enables debug support for the Bluetooth Service Discovery Protocol (SDP). config BT_DEBUG_SERVICE bool "Bluetooth Services debug" depends on BT_CONN help This option enables debug support for the Bluetooth Services. endif # BT_DEBUG 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 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]" 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 help This option enables Bluetooth HF support config BT_AVDTP bool "Bluetooth AVDTP protocol support [EXPERIMENTAL]" help This option enables Bluetooth AVDTP support config BT_A2DP bool "Bluetooth A2DP Profile [EXPERIMENTAL]" select BT_AVDTP 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