1# Change Log 2All notable changes to this project will be documented in this file. 3 4The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) 5and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html). 6 7--- 8 9## Unreleased 10 11### Added 12- GAP: support periodic advertising with ENABLE_LE_PERIODIC_ADVERTISING 13 14### Fixed 15 16### Changed 17 18 19## Release v1.5.2 20 21### Added 22- GAP: ENABLE_HCI_SERIALIZED_CONTROLLER_OPERATIONS serializes Inquiry, Remote Name Request and Create Connection operations 23- GAP: support extended advertising with ENABLE_LE_EXTENDED_ADVERTISING 24- GAP: gap_enable_link_watchdog() uses automatic flush timeout to disconnect if data cannot be sent 25- GAP: gap_secure_connections_active() to query if BR/EDR Secure Connecions are possible 26- ATT DB: provide gatt_server_get_handle_range_for_service_with_uuid16 to find included service within handle range 27- GATT Service: Audio Input Control Service Server (AICS 1.0) 28- GATT Service: Microphone Control Service Server (MCS 1.0) 29- GATT Service: Volume Control Service Server (VCS 1.0) 30- GATT Service: Volume Offset Control Service Server (VOCS 1.0) 31 32### Fixed 33- POSIX: fix RTS/CTS configuration by keeping local termios copy in btstack_uart_posix 34- HCI: fix handling of HCI Connection Complete with error (regression introduced in v1.5.1) 35- GAP: disable scanning, advertising, connection before updating random address 36- GAP: fix LE Scan with whitelist 37- HFP_AG: fix tracking for call dropped during outgoing ringing 38- HFP: Free HFP Connection object on SDP error / Service not found 39- PBAP Client: emit operation complete with status OBEX_ABORTED 40 41### Changed 42- Chipset: use da145xx in folder/file/function names for Dialog Semiconductor SoCs 43- GAP: set min encryption key size during init, if supported 44- AVDTP: use BLUETOOTH_SERVICE_CLASS_AUDIO_SINK / SOURCE instead of BLUETOOTH_PROTOCOL_AVDTP in SDP queries 45- ATT Server: use uint8_t for status returns 46- libusb, POSIX and Windows ports: use '-' instead of ':' in btstack_BD_ADDR.tlv filename 47 48 49## Release v1.5.1 50 51### Added 52- GOEP Client: add goep_client_version_20_or_higher 53- ESP32: implement audio source 54 55### Fixed 56- PBAP Client: support disconnect while operation is ongoing 57- PBAP Client: use SRM only if GOEP v2.0 or higher connection 58- PBAP Client: emit vCard entry data as PBAP_DATA_PACKET 59- L2CAP: limit remote MTU by local tx configuration in ERTM 60 61### Changed 62- Example: init SM if LE supported to avoid issue with Android Cross-Transport Key-Derivation 63- ESP32: update sdkconfig for esp-idf v4.3, disable Bluedroid host stack 64- ESP32: use I2S configuration from ESP32 LyraT V4.3 65 66 67## Release v1.5.0 68 69### Added 70- HCI Dump: Support BTSnoop format in hci_dump_posix_fs.c for format = HCI_DUMP_BTSNOOP 71- HCI Dump RTT STDOUT: drop messages if RTT buffer is full and RTT is configured for non-blocking 72- HCI: hci_remove_event_handler to remove packet handler 73- hci_cmd: support variable length fields and arrayed parameters 74- GAP: ENABLE_EXPLICIT_LINK_KEY_REPLY allows for asynchronous link key lookup by application 75- GAP: gap_set_page_timeout to set Page Timeout 76- GAP: gap_inquiry_set_scan_activity to set Inquiry Scan Activity 77- L2CAP: emit L2CAP_EVENT_INFORMATION_RESPONSE event with extended features and fixed channels supported 78- L2CAP: support Enhanced Credit-based Flow-Control Mode for connection-oriented channels over BR/EDR/LE 79- A2DP: allow to register media codec validator for sink and source with: 80 - `a2dp_sink_register_media_config_validator` 81 - `a2dp_source_register_media_config_validator` 82- A2DP Sink: allow accept or reject of stream start on A2DP_SUBEVENT_START_STREAM_REQUESTED when ENABLE_AVDTP_ACCEPTOR_EXPLICIT_START_STREAM_CONFIRMATION is defined 83- OBEX: new obex_parser for chunked OBEX data 84- SM: Support Cross-Transport Key-Derivation (CTKD) of LE LTK from BR/EDR SC Link Key in Responder role 85- SM: sm_remove_event_handler to remove packet handler 86- GATT Service: Bond Management Service (BMS 1.0) Server 87- GATT Service: Microphone Control Service (MICS 1.0) Server 88- GATT Service: TX Power Service (TPS 1.0) Server 89- POSIX: btstack_signal allows to register for callback on signal, e.g. ctrl-c 90- Windows: btstack_stdin_window_register_ctrl_c_callback allows to register for ctrl-c 91 92### Fixed 93- A2DP Source: fix reconfigure 94- AVRCP Controller: prevent registering of notifications for unsupported events 95- RFCOMM: fixed handling of remote port configuration command 96- HFP AG: fix accept incoming connection while audio connection is established 97- PBAP Client: handle chunked vCard Listing 98- PBAP Client: use new streaming obex_parser to handle chunked OBEX data 99- SM: Work around for unexpected Windows 10 disconnect for BR Secure Connections (SMP over BR timeout) 100- SM: support storing bonding information for devices with identical IRK but different public addresses 101- GAP: restart advertising when private address changes 102- le_device_db_tlv: keep number of devices reported by le_device_db_count if old entry is replaced 103 104### Changed 105- Drop iOS support 106- HCI: provide status instead of undocumented int error code and bool for API functions 107- HCI: use 1000 ms watchdog to force power off for hci_power_control(HCI_POWER_OFF) 108- GAP: local name, EIR data, class of device and default link policy can be updated at any time 109- L2CAP: provide status instead of undocumented int error code and bool for API functions 110- L2CAP: remote features not required for SDP connections 111- L2CAP: replaced l2cap_register_packet_handler with l2cap_add_event_handler to register multiple handlers 112- L2CAP: drop reason parameter in l2cap_disconnect 113- L2CAP: use official terminology for L2CAP channel modes - ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE replaces ENABLE_LE_DATA_CHANNELS 114- L2CAP: unify API for can send now, request to send, and send packet and disconnect channel 115- L2CAP: unify events for can send now, packet sent, channel closed (CbM/ECBM using existing events) 116- RFCOMM: `RFCOMM_EVENT_PORT_CONFIGURATION` contains rfcomm_cid and remote flag, emitted for query config 117- RFCOMM: provide status instead of undocumented int error code and bool for API functions 118- RFCOMM: remote port configuration, line status, and modem status are sent by channel state machine 119- HSP: add ACL Connection to all events and BD ADDR to HSP_SUBEVENT_RFCOMM_CONNECTION_COMPLETE 120- HFP: API functions return status code if appropriate 121- HFP: removed one parameter from hfp_ag/hf_activate_voice_recognition function, introduce hfp_ag/hf_deactivate_voice_recognition instead 122- HFP: merged legacy and enhanced Voice Recognition Activation (VRA) API. If available enhanced mode will be preferred. 123- HFP: separate events for activation (HFP_SUBEVENT_VOICE_RECOGNITION_ACTIVATED) and deactivation (HFP_SUBEVENT_VOICE_RECOGNITION_DEACTIVATED) instead of combined HFP_SUBEVENT_VOICE_RECOGNITION_STATUS with status field. HFP_SUBEVENT_VOICE_RECOGNITION_ACTIVATED contains field "enhanced" to indicate if enhanced mode is used. 124- HFP: enhanced VRA: HFP_SUBEVENT_VOICE_RECOGNITION_ACTIVATED is emitted after VRA is ready and the the audio connection is established. This simplifies HFP HF client logic, i.e. client can call `hfp_hf_enhanced_voice_recognition_report_ready_for_audio directly` upon reception of HFP_SUBEVENT_VOICE_RECOGNITION_ACTIVATED event. 125- AVDTP: media config validator is called with preview of media codec configuration event and configured separately for sink/source 126- AVRCP: use PANEL as default unit + subunit info 127- AVRCP Controller: automatically query supported events when registering for notifications 128- AVRCP Target: cache companies and events in library and remove need to answer query in application callback. Use Bluetooth SIG as default company. 129- Run Loop: new functionality for HCI transport drivers and inter-process communication: 130 - *btstack_run_loop_poll_data_sources_from_irq*: used to transfer control from IRQ handler to main thread/run loop 131 - *btstack_run_loop_execute_on_main_thread*: schedule code execution on main thread from other thread 132 - *btstack_run_loop_trigger_exit*: trigger run loop exit 133- POSIX / Windows / Raspi / Qt: use updated ctrl-c handling 134- POSIX TLV: use max value size of 2048, assert in store function if value size is larger 135 136 137## Release v1.4.1 138 139### Added 140- GAP: emit GAP_EVENT_PAIRING_STARTED and GAP_EVENT_PAIRING_COMPLETE 141 142### Fixed 143- GAP: store link key in hci connection struct to allow authenticate after pairing without bonding 144- GAP: avoid requesting authentication twice 145- GAP: cache own address on start advertising and connecting, provide getters 146- GAP: stop LE connecting if create connection fails (e.g. connectable adv active and multiple roles not supported) 147- SM: fix race condition between local address changes and pairing procedure 148- ATT DB: fix spelling `gatt_server_get_handle_range_for_service_with_uuid128`, `gatt_server_get_handle_range_for_service_with_uuid16` 149 150### Changed 151- HCI: update advertising data without stopping advertising first 152- GAP: Drop local bonding flag in IO Capability Reply if remote does not indicate bonding 153- GAP: return status for `gap_set_security_mode` 154- GAP: abort legacy pairing if Level 4 is required 155- GAP: abort SSP on IO Capabilities Request event if Level 4 is required but SC not supported by remote 156- GAP: abort SSP on User Confirmation Request event if Level 3 is required but MITM protection not possible 157- GAP: validate minimal service security level can be reached during pairing in responder role 158- L2CAP: don't trigger hci disconnect if l2cap security requirements are insufficient 159- CVE-2020-26555: reject connections to and from devices with same BD ADDR 160- CVE-2020-26555: ignore NULL link key 161- CVE-2020-26558: abort LE Secure Connection pairing if remote uses the same public key 162 163## Release v1.4 164 165### Added 166- HCI: `btstack_transport_sco.h` supports SCO over physical PCM/I2S interface (`HAVE_SCO_TRANSPORT`) 167- POSIX: `btstack_transport_sco_i2s_test_bridge.c` implements SCO transport interface for UART-to-I2S test bridge 168- btstack_uart: `btstack_uart_t` interface extends `btstack_uart_block_t`: 169 - support sending and receiving SLIP frames for HCI H5 170 - support odd parity 171 - `hci_transport_h4` and chipset drivers have new functions to provide `btstack_uart_t` 172- btstack_uart_slip_wrapper: wrapper that implements SLIP functionality for existing `btstack_uart_block` drivers. 173- hci_transport: add parity field and pass on to `btstack_uart_t` in h4 and h5 174- GATT Client: Battery Service Client 175- GATT Client: Device Information Service Client 176- GATT Client: HID-over-GATT (HOG) Client, Report and Boot Host 177- GATT Client: Scan Parameters Service Client 178- GATT Server: Scan Parameters Service Server 179- GAP: support scan page configuration with `gap_set_page_scan_activity` and `gap_set_page_scan_type` 180- GAP: support sniff subrating with `gap_sniff_subrating_configure` 181- GAP: support QoS setup with `gap_qos_set` 182- AVRCP: new field `button_pressed` in `AVRCP_SUBEVENT_OPERATION` 183- AVRCP: `AVRCP_SUBEVENT_OPERATION` emitted for button release 184- AVRCP Controller: `avrcp_controller_start_press_and_hold_cmd` supports arbitrary device buttons 185- AVRCP Controller: reassemble fragmented AVCTP packets 186- AVDTP: `avdtp_register_media_config_validator` allows to validate media codec configuration 187- A2DP Source: `ENABLE_A2DP_SOURCE_EXPLICIT_CONFIG` disables auto config. requires call to `a2dp_source_set_config_{CODEC}` 188 189### Fixed 190- GAP: calculate IO Cap AuthReq Bondable Mode based on `gap_ssp_set_authentication_requirement` and `gap_set_bondable_mode` 191- GAP: only store link key for SSP if remote side has set bondable in io cap auth requirements 192- GAP: allow to disable link supervision timeout 193- GAP: fix `gap_connect` after `gap_connect_cancel` 194- GAP: re-configure advertisements after power cycle 195- HCI: handle start inquiry failure 196- L2CAP: fix create outgoing connection triggered from packet handler on hci disconnect event 197- L2CAP: return unknown mandatory option in config response 198- AVDTP: fix spelling `avdtp_set_preferred_sampling_frequency` 199- AVRCP Target: fix notification changed event 200- HFP: Emit audio connection released on SLC Release, e.g. on remote power off 201- HFP HF: fix audio connection setup if codec negotiation is supported 202- HFP HF: only emit single event for RING and AG Status updates 203- HFP AG: fix audio connection setup for in-band ringtone on incoming connection 204 205### Changed 206- Port Archive: moved ports that are not recommended for new designs to port/archive folder: 207 - MSP430: the ports used the older community GCC version without 20-bit support needed for code size > 64kB 208 - Broadcom/Cypress H5: uploading PatchRAM is only possible in H4 mode. It's better to also use H4 in general 209 - PIC32-Harmony: the port used Harmony v1 while Harmony v3 has been out since a while 210 - iOS: not supported 211- Run Loop Base: functionality used in most platform run loop implementations 212 - code from `btstack_run_loop_base.c` moved into `btstack_run_loop.c` to minimize changes to build systems 213 - `btstack_run_loop_base.c` is a placeholder and can be removed from build 214- HCI Dump: replace monolithic `hci_dump.c` (with many #ifdefs) into dispatcher with platform-specific implementations: 215 - `posix/hci_dump_posix_fs` - writes binary log file 216 - `posix/hci_dump_stdout` - log to console using printf with local system time 217 - `embedded/hci_dump_embedded_stdout` - log to console using printf 218 - `embedded/hci_dump_segger_stdout` - log to RTT console using `SEGGER_printf` 219 - `embedded/hci_dump_segger_binary` - writes binary log over RTT to host 220- HCI: config I2S for BCM Controllers if `ENABLE_SCO_OVER_PCM`, reduce bit clock to 256/512 kHz 221- btstack_uart_posix: supports SLIP frames and replaces `btstack_uart_block_posix` 222- hci_transport_h5: more performant H5 implementation that requires `btstack_uart_t` driver with SLIP support 223- POSIX Ports: use new `btstack_uart_posix` implementation 224- posix-h5/posix-h5-bcm: use even parity for UART 225- HCI Transport: extract convenience function declaration for h4, h5, em9304_spi, and usb into separate hci_transport_{type}.h 226- GAP: provide Device ID from EIR in GAP_EVENT_INQUIRY_RESULT 227- GAP: only store link key if it allows requested security level 228- GAP: abort SSP pairing if MITM protection required but not possible 229- SM: start pairing as Central for already encrypted connection on Slave Security Request 230- GATT Client: Use ATT_READ_REQUEST for first blob of Read Long Characteristic and Read Long Characteristic Descriptor 231- GATT Server: Allow ATT Read Callback to return custom ATT Error Code 232- Nordic SPP Service Server: use `GATTSERVICE_SUBEVENT_SPP_SERVICE_CONNECTED` and `GATTSERVICE_SUBEVENT_SPP_SERVICE_CONNECTED` 233 events instead of callback, and `RFCOMM_DATA_PACKET` for received data 234- u-blox SPP Service Server: use `GATTSERVICE_SUBEVENT_SPP_SERVICE_CONNECTED` and `GATTSERVICE_SUBEVENT_SPP_SERVICE_CONNECTED` 235 events instead of callback, and `RFCOMM_DATA_PACKET` for received data 236- HID: Move `src/classic/hid.h` into `src` and prefix with `btstack_` to use it with BLE and avoid name clashes 237- HFP: provide acl_handle in events to identify connection 238- HSP AG: emit HSP_SUBEVENT_BUTTON_PRESSED instead of audio connection setup/release 239- Example: use `btstack_event.h` getters instead of direct array access, use enum to compare status codes 240 241 242## Release v1.3.2 243 244### Added 245- GAP: support for Classic Out-of-Band (OOB) pairing via `gap_ssp_remote_oob_data` with `ENABLE_CLASSIC_OOB_PAIRING` 246- GAP: read local OOB data on start and on call to `gap_ssp_generate_oob_data`, provided via `GAP_EVENT_LOCAL_OOB_DATA` 247- HID Host: add profile, update `hid_host_demo.c` example 248 249### Fixed 250- L2CAP: make handling of HCI disconnect more robust 251- AVDTP: emit stream release for active stream if signaling connection is closed first, e.g. caused by HCI disconnect 252- AVRCP: fix issue when Controller and Target send at the same time 253 254### Changed 255- A2DP, AVDTP: use `a2dp_source_set_config_{TYPE}` and `avdtp_config{TYPE}_store` to avoid large number of parameters 256 257 258## Release v1.3 259 260### Added 261- CC256x: with ENABLE_CC256X_ASSISTED_HFP, HFP enables WBS codec on demand and configures PCM/I2S interface for 8kH/16kHz 262- BCM: with ENABLE_BCM_PCM_WBS, HFP enables WBS codec on demand and configures PCM/I2S interface for 8kH/16kHz 263- SDP Client RFCOMM: add `sdp_client_query_rfcomm_channel_and_name_for_service_class_uuid` 264- HFP: `ENABLE_HFP_AT_MESSAGES` lets HFP emit `HFP_SUBEVENT_AT_MESSAGE_SENT` and `HFP_SUBEVENT_AT_MESSAGE_RECEIVED` 265- A2DP, AVDTP: provide capabilities and configuration events for A2DP codecs: SBC, MPEG Audio, MPEG AAC, ATRAC 266- A2DP + AVDTP Source: allow to send media packet with `avdtp_source_stream_send_media_packet` and `a2dp_source_stream_send_media_packet` 267- A2DP + AVDTP Source: add `avdtp_source_stream_send_media_payload_rtp` and `a2dp_source_stream_send_media_payload_rtp` 268- A2DP Source: emit `A2DP_SUBEVENT_SIGNALING_CAPABILITIES_COMPLETE` 269- A2DP Source: allow to configure endpoints by calling `a2dp_source_set_config_{TYPE}` during SEP discovery with SBC fallback 270 271### Fixed 272- HCI: keep `le connecting request` on connection complete active, fixes gap_auto_connection_stop() + gap_auto_connection_start() 273- L2CAP: fix packet size check for incoming classic basic channels (regression introduced in v1.2.1) 274- HFP AG/HSP AG: avoid connecting to remote service with same role 275- A2DP Source: support multiple Stream Endpoints with different Media Codec types 276- A2DP Source: emit codec configure event with reconfigure flag set on reconfigure 277- GATT Compiler: support multiple instances of the same service 278 279### Changed 280- GAP: provide Link Type parameter to incoming connection filter for `gap_register_classic_connection_filter` 281- HFP/GOEP Client/AVDTP/A2DP: return `SDP_SERVICE_NOT_FOUND` if no suitable SDP record is found 282- AVDTP Source: `avdtp_source_stream_send_media_payload` includes SBC Header and was deprecated 283- AVDTP/A2DP: use `avdtp_channel_mode_t` in `A2DP_SUBEVENT_SIGNALING_MEDIA_CODEC_SBC_CONFIGURATION` 284- A2DP: fix events and use `a2dp_cid`, `local_seid,` `remote_seid` field names in A2DP sub-events 285- GATT Client: Skip MTU exchange after MTU exchange on ATT Server 286- Ports: STM32-F103RB Nucleo + CC256x port removed 287- ESP32: enabled HFP Wide-Band Speech, disable classic secure connections in HSP/HFP demos 288 289 290## Release v1.2.1 291 292### Fixed 293- L2CAP: use connection handle for channel lookups 294- L2CAP: forward data only in open state 295 296### Changed 297- L2CAP: check packet size against local mtu for classic basic channels 298 299 300## Release v1.2 301 302### Fixed 303- L2CAP: trigger pairing for outgoing LE Data Channels if security level insufficient 304- SM: fix update of sc flag for re-encrypted connection in peripheral role 305- SM: send security request on re-connect if bonded and `ENABLE_LE_PROACTIVE_AUTHENTICATION` is defined 306- ESP32: fix audio sink driver 307 308### Added 309- GAP: `gap_delete_bonding` removes device from LE Resolving List and from discards LE bonding information 310- GATT Client: delete bonding information if re-encryption fails and `ENABLE_LE_PROACTIVE_AUTHENTICATION` is not defined 311- GATT Client: gatt_client_set_required_security_level() allows to set required minimum security level for all GATT requests 312- SM: emit events for re-encryption started/complete when bonding information is available 313 314### Changed 315- AVRCP Controller: allow to send multiple absolute volume commands without waiting for response. 316- GAP: replaced `ENABLE_LE_CENTRAL_AUTO_ENCRYPION` with `ENABLE_LE_PROACTIVE_AUTHENTICATION` 317 318 319## Changes October 2020 320 321### Fixed 322- AVDTP Initiator: avoid use of remote seid for stream endpoint lookup, fixes issue with two connected devices 323- AVDTP Source: buffer for SBC media codec information got discarded, leading to invalid Set Configuration command in second connection 324- SM: only trigger Cross-Transport Key Derivation (CTKD) when bonding is enabled 325- SM: set LinkKey flag to request CTKD if enabled 326- SM: store CTKD key with Public Identity Address 327- SM: only allow CTKD to overwrite existing link key if derived key has same or higher authentication 328- SM: start SMP Timeout when sending Security Request 329- HFP HF: fix response to AG Codec Selection while waiting for OK of parallel command 330- HCI: fix reject of LE remote connection param request via HCI 331 332### Added 333- GAP: add `gap_get_link_key_for_bd_addr` 334- GAP: add `gap_bonded` to check if bonding information is available for active connection 335- SM: support h7 for CTKD 336 337### Changed 338- SM: Cross-Transport Key Derivation requires `ENABLE_CROSS_TRANSPORT_KEY_DERIVATION` now 339- SM: block connection if encryption fails for bonded devices as Central 340- SM: support pairing as Central after failed re-encryption 341 342 343## Release v1.1 344 345### Fixed 346- AVRCP/AVCTP: report AVRCP 1.6 and AVCTP 1.4 in SDP record 347 348### Added 349 350### Changed 351 352 353## Changes September 2020 354 355### Fixed 356- HFP: fix parsing of ranges e.g. in +CIND responses 357- AVDTP, AVRCP: fix bugs due to transaction id overrun 358- A2DP Source: fix issues with stream configuration by sink 359- hci_dump: fix tv_us calculation for non-posix / embedded systems with binary output 360 361### Added 362- `btstack_ring_buffer`: add `btstack_ring_buffer_reset` to reset it to initial state/empty 363- GAP: Support for address resolution of resolvable private addresses by Controller with `ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION` 364 365### Changed 366- AVDTP, AVRCP, HSP: schedule SDP query, avoids avoids 'command disallowed' if SDP client is busy 367- HSP, HFP: allow to configure usable SCO packet types 368- cc256x: update CC256xC init script to v1.4 369- A2DP Source: use Get All Capabilities if supported by remote get Delay Reporting capability 370 371## Changes August 2020 372 373### Fixed 374- ESP32: fix authentication for incoming Secure Connections 375- AVDTP: Fix forwarding of Delay reports 376- STM32-F4Discovery: fix pan_lwip_http_server by increasing HCI_ACL_PAYLOAD_SIZE 377- tool/create_packet_log: basic support for 16-bit Unicode log files from Windows 378 379### Added 380- `btstack_run_loop_base`: added `btstack_run_loop_base_dump_timer` 381- GAP: request role change for classic connection via `gap_request_role` 382- GAP: LE Whitelist API with `gap_le_whitelist_x` with x = add, remove, clear and new `gap_connect_with_whitelist` 383- SDP Client: add sdp_client_register_query_callback() allows to register query request instead of polling sdp_client_ready() 384- BNEP lwIP: add `bnep_lwip_connect` to establish BNEP connection and manage lwIP network interface 385- New `btstack_linked_queue` utility, a linked list-based queue with first-in-first-out semantics and constant time enqueue/dequeue operations 386- btstack_tlv_posix: add `btstack_tlv_posix_deinit` 387- New `btpclient` for use with [auto-pts project](https://github.com/intel/auto-pts) 388 389### Changed 390- GAP: treat AES-CCM encrypted connection as mutually authenticated (BIAS) 391- GAP: 'gap_auto_connect_x' API deprecated. Please directly manage LE Whitelist with `gap_le_whitelist_*` functions and call `gap_connect_with_whitelist` instead 392- example/hid_host_demo: try to become master for incoming connections 393- btstack_run_loop: use btstack_assert instead of local while(true) 394- att_db_util: allow to reset att_db via `att_db_util_init` 395 396## Changes July 2020 397 398### Fixed 399- AVDTP: fix invalid response for Get Capabilities request if Delay Reporting was supported 400- AVDTP: handle concurrent signaling establishment with reject and retry 401 402### Added 403- example/hid_host_demo: support reconnect from HID device 404- Crypto: support software AES128 for AES-CCM operations 405- AVRCP: introduced AVRCP_FEATURE_MASK_* as alternative to avrcp_controller_supported_feature_t and avrcp_target_supported_feature_t enums 406- btstack_audio: add set_volume() to sink and set_gain() to source interfaces, minimal volume control for portaudio playback 407- AVDTP: renamed definition of supported features from AVDTP_SOURCE_SF_ and AVDTP_SINK_SF_ to AVDTP_SOURCE_FEATURE_MASK_ and AVDTP_SINK_FEATURE_MASK_ respectively 408- GAP: Provide gap_get_role to query master/slave role for HCI connection handle 409- GAP: Provide gap_pin_code_response_binary to use binary data as PIN, e.g. for pairing with Nintendo Wii Remote 410 411### Changed 412- GAP: set minimum required encryption key size for Classic connections back from 16 to 7, matching the Core spec 413 414 415## Changes June 2020 416 417### Fixed 418- HFP: Fix parsing of empty fields, e.g. phone number in +CLCC and other AT commands 419- SM: Fix validation of confirm value for secure connection Passkey entry 420- AVRCP: handle concurrent signaling establishment with reject and retry 421 422### Added 423- GAP: Detect Secure Connection -> Legacy Connection Downgrade Attack by remote features and actual encryption type (BIAS) 424- GAP: Mutual authentication: request authentication after Classic connection got encrypted (BIAS) 425- Windows port for Dialog DA14585 connected via serial port 426 427## Changes 428- CVSD PLC: treat zero frames as good and allow to mark data as bad, e.g. if reported by Controller as erroneous 429 430## Changes May 2020 431 432### Fixed 433- hfp_hf, hsp_hs: use eSCO params in accept sco connection only for incoming eSCO connections 434- pbap_client: fix PBAP UUID len on connect message 435- SM: fix secure connection pairing as peripheral when local user confirmation happens after remote one 436- A2DP Source: only connect to remote sink stream endpoints 437- btstack_hal_flash_memory: fix write of 0xff bytes to simulated flash 438- hsp_hs: fix disconnect if audio not connected 439- hsp_ag: fix accept incoming connection 440 441### Added 442- example/le_mitm: MITM implementation that forwards ATT PDUs and allows for pairing 443- GAP: gap_set_security_level sets required security level for incoming and outgoing connections 444- cc256x: allow to specify power vector for each modulation type 445- FreeRTOS: btstack_run_loop_freertos_trigger_exit allows to request run loop exit 446- SM: support LE Secure Connections Only mode with sm_set_secure_connections_only_mode 447- GAP: enable BR/EDR Secure Connections if supported, add gap_secure_connections_enable 448 449### Changed 450- L2CAP ERTM: send extended features request only once per HCI connection 451 452 453## Changes April 2020 454 455### Fixed 456- hog_mouse_demo/hog_keyboard_demo: handle set protocol mode = boot protocol mode 457- HCI: only update BD_ADDR placeholder in shortened and complete name in EIR data, limit device name to 240/248 bytes 458 459### Added 460- GAP: gap_set_allow_role_switch allows to prevent role switch in outgoing classic ACL connections 461- example: hog_boot_host_demo implements an HID-over-GATT Boot Host that supports keyboard and mouse 462- HCI: add ENABLE_LE_LIMIT_ACL_FRAGMENT_BY_MAX_OCTETS that forces fragmentation of ACL-LE packets to fit into over-the-air packet 463 464### Changed 465- Broadcom/Cypress: wait 300 ms after PatchRAM update in hci.c to assert Controller is ready 466- esp32: provide esp-idf/component/btstack/btstack_port_esp32.c and only minimal app_main in template/main/main.c 467- att_db: skip att_read_callback for ATT Read Blob Request if offset == value_len 468 469 470## Changes March 2020 471 472### Fixed 473- GAP: fixed gap_set_scan_parameters() if issued right before gap_start_scan() 474- HCI: only send HCI Read Local Encryption Key Size if supported by Controller 475 476### Added 477- GATT Client: allow to register for any notification/indication and/or any connection 478- HCI: added hci_read_inquiry_scan_activity and hci_write_inquiry_scan_activity commands 479- chipset: assert hci packet buffers are suitable for firmware upload or patches (atwilc3000,bcm,cc256x,intel) 480- btstack_util: added btstack_replace_bd_addr_placeholder 481 482### Changed 483- AVRCP Target: volume in avrcp_target_volume_changed is reported as current value in interim response to register for volume change notifications 484- SDP Client: query attributes 0x0000..0xffff instead of 0x0001..0xffff to match other stacks / improve compatibility with bad sdp server implementations 485 486 487## Changes Februar 2020 488 489### Fixed 490- AVRCP Target: fix reporting of PLAYBACK_STATUS_CHANGED 491- HCI: handle reconnect request for Classic and LE connections triggered by packet handler for Disconnection Complete Event 492 493### Changed 494- hid_host_mode: allow sniff mode 495 496### Added 497- port/qt-usb and port/qt-h4: integrate BTstack Qt run loop for Unix- and Win32-based Qt application connected to Bluetooth module via H4 over serial port or USB 498 499 500## Changes January 2020 501 502### Fixed 503- L2CAP ERTM: avoid read-after-free on decline of incoming connection 504- GATT Client: set uuid16 to zero when deserializing uuid128 services, characteristics, and descriptors 505- att_db_util: fix realloc of att db buffer for large attributes 506- btstack_tlv_posix: only keep last value in memory, fix delete operation 507- l2cap_signaling: use packet boundary flags 0x00 for LE signaling packets (ignoring hci_non_flushable_packet_boundary_flag_supported()) 508 509### Added 510- att_db_util: provide GATT Database Hash via att_db_util_hash_calc 511- GATT Compiler: provide GATT Database Hash via GATT_DATABASE_HASH Characteristic 512- ATT Server: validate request pdu length 513 514### Changed 515- Crypto: update AES-CMAC implementation to access all message bytes sequentially 516 517 518## Changes December 2019 519 520### Fixed 521- example/pan_lwip_http_server: use Network Access Point, CoD 522- sm: emit pairing complete in master role when no keys are distributed / bonding disabled 523 524### Added 525 526### Changed 527- Updated CC256x initscript: CC256xC v1.3 528- ESP32: add CMake project files 529 530 531## Changes November 2019 532 533### Fixed 534- AVDTP Source: return correct `avdtp_cid` and `local_seid` in `AVDTP_SUBEVENT_STREAMING_CAN_SEND_MEDIA_PACKET_NOW` 535- L2CAP: send LE Data Channel SDUs round robin with other data 536- L2CAP ERTM: send ERTM I-frames round robin with other data 537 538### Added 539- ATT Server: return error if request to send now for Notification or Indication already registered 540- Linked List: return if item was added for `btstack_linked_list_add[_tail]` 541- btstack_run_loop_remove: return bool true if timer/data source was removed 542- segger-rtt: allow to configure with `SEGGER_RTT_PACKETLOG_*` directives, update to v6.54 543- GAP: support setting Link Supervision Timetout for outgoing Classic connections using `gap_set_link_supervision_timeout` 544- lwip: add download test files to http server demo 545 546### Changed 547- Linked List: return bool true if item was removed 548 549 550## Changes October 2019 551 552### Fixed 553 554### Added 555- `btstack_bool.h`: provide boolean type 'bool' via `<stdbool.h>` or as backport 556- provide `btstack_assert(condition)` 557- H4 Transport: avoid calling `hci_transport_h4_trigger_next_read` when transport is closed 558 559### Changed 560- libusb and posix ports: store bonding information in TLV 561 562 563## Changes September 2019 564 565### Fixed 566- L2CAP ERTM: assert that packet can be stored in fragment buffers in ertm 567- L2CAP ERTM: reject incoming connection if ERTM is configured as mandatory but not supported by remote 568- GATT Client: allow Write Without Response independent of other requests 569 570### Added 571- GAP: allow to reject GAP classic connection via gap_register_classic_connection_filter 572- GAP: support reading RSSI for Classic+LE using gap_read_rssi. Emits `GAP_EVENT_RSSI_MEASUREMENT` 573 574### Changed 575- Bluetooth and BTstack Error Codes and Events: collect status codes in bluetooth.h and events in btstack_defines.h 576- bluetooth.h: extract internal defintitions to respective protocol layers 577- Updated CC256x initscripts (CC256xB v1.8, CC256xC v1.2, CC256xC v1.2) 578 579 580## Changes August 2019 581 582### Fixed 583- POSIX, WICED, Windows, FreeRTOS run loops: handle time_ms overrun after 49 days 584- RFCOMM: accept incoming L2CAP connection in Basic mode if ERTM is enabled but not requested for this connection 585- RFCOMM: limit RFCOMM MTU by local L2CAP MTU for outgoing connections (only revelvant for ERTM) 586- L2CAP ERTM: stop timers on disconnect 587- L2CAP ERTM: fix sending of segmented SDUs 588- L2CAP ERTM: handle unsupported Information Response 589- SM: generate local nonce for confirm value in JW+NC+PK in Secure Connections Responder role 590 591### Added 592- `btstack_run_loop_base`: portable implementation of timer and data source management as base for platform specific implementations 593 594## Changed 595- FreeRTOS: use xQueueCreateStatic (static variant of xQueueCreate) if available for static memory-only setups 596- L2CAP ERTM: handle invalid Information Response (assume no extended features supported) 597- POSIX: use monotonic clock as timebase if available 598- HCI Transport H4/H5/EM9304 SPI: ignore block read/sent from UART driver when closed 599- HCI: Read Encryption Key Size after encryption was enabled 600- Errata 11838: 601 - GAP: gap_set_required_encryption_key_size allows to set the required key size, default = 16 (max) 602 - GAP: validate encryption key size to emit GAP Security Levels 603 604## Changes July 2019 605 606### Fixed 607- SM: Fixed regression introduced in f3582630 608- L2CAP: avoid reading l2cap signaling command len out of bounds 609- HCI Transport H4/H5/EM9304 SPI: fix payload size checks (also for 8/16-bit platforms) 610 611### Changed 612- SM: Start encryption upon receiving slave securiy request if bonded 613- hci: use 2 as HCI_INCOMING_PRE_BUFFER_SIZE in LE-only configuration for GATT Client 614 615--- 616 617## Changes June 2019 618 619### Changed 620- FreeRTOS: use freertos/.. prefix to include FreeRTOS headers if HAVE_FREERTOS_INCLUDE_PREFIX is defined 621- BNEP: add Connection Handle to BNEP_EVENT_CHANNEL_OPENED 622- Examples: renamed le_counter to gatt_counter and le_streamer to le_streamer_server to indicate suppport for GATT over BR/EDR 623 624### Fixed 625- BNEP: Bluetooth address is stored in little-endian format for all BNEP_EVENT_* 626- libusb: avoid use-after-free for SCO packets on disconnect 627 628### Added 629- example: pan_lwip_http_server using lwIP as network stack to implement PAN NAP service 630- platform/lwip/bnep_lwip.c: BNEP lwIP adapter that forwards packets between BNEP service and lwIP 631- ENABLE_GATT_OVER_CLASSIC enables support for GATT over BR/EDR in att_server 632 633--- 634 635## Changes May 2019 636 637### Changed 638- ESP32: Configure SCO over HCI after power up 639- btstack_tlv_flash_bank: support targets where a value cannot be overwritten with zero. When ENABLE_TLV_FLASH_EXPLICIT_DELETE_FIELD 640 is defined, an explicit delete field is used to indicate an invalid entry. 641 642### Fixed 643- SM: Avoid potential use-after-free on immediate disconnect (lookup connection via con handle instead of storing pointer) 644 645### Added 646- gatt_client: emit query complete event for signed write operation 647- hci_transport_h4: add workaround for flow control bug in CYW2070x, enable with ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND 648 649--- 650 651## Changes April 2019 652 653### Changed 654- ESP32: use micro-ecc from 3rd-party as esp-idf removed it in their 3.3 release 655 656### Fixed 657- hci: pad LE Scan response with zeroes 658- SM: store local CSRK 659- ATT DB: call write callback for validated signed writes 660- ATT Server: abort signed write validation on incoming new request 661- Bluetooth SIG web scraping tools updated 662- libusb: compiles for FreeBSD 663 664### Added 665 666--- 667 668## Changes March 2019 669 670### Changed 671- use Makefile for stm32-f4discovery-cc256x port 672- le_device_db: add secure_connection argument to le_device_db_encryption_set and le_device_db_encryption_get 673 674### Fixed 675- SM: Use provided authentication requirements in slave security request 676 677### Added 678- port/stm32-f4discovery-cc256x: add support for built-in MEMS microphone 679- SM: Track if connection encryption is based on LE Secure Connection pairing 680- ATT DB: Validate if connection encrypted is based on SC if requested 681- att_db_util: support ATT_SECURITY_AUTHENTICATED_SC permission flag 682- GATT Compiler: support READ_AUTHENTICATED and WRITE_AUTHENTICATED permsission flags 683- ESP32: erase nvs flash is newer nvs version found 684- libusb: add support for nRF52840-PCA10056 running Zephyr hci_usb example 685- port/stm32-l073rz-nucleo-em9304 for Nucleo L073RZ with EM9304 DVK, replaces port/stm32-l053r8-nucleo-em9304 686 687## Changes February 2019 688 689### Changed 690- example/a2dp_sink_demo: use linear resampling to fix sample rate drift 691- btstack_audio: split interface into sink and source 692 693### Fixed 694- Crypto: fix lockup when stack is shutdown while waiting for result of HCI Command, e.g. LE Read Local P256 Public Key 695- SM: Avoid SM_EVENT_PAIRING_COMPLETE with ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION after successful pairing in responder role 696 697### Added 698- example/a2dp_sink_demo: add target role, support volume control on both devices 699- example/audio_duplex: playback audio audio source on audio sink (test audio path) 700- btstack_audio_embedded: implement audio source path 701 702--- 703 704## Changes January 2019 705 706### Changed 707- L2CAP: provide channel mode (basic/ertm) and fcs option in L2CAP_EVENT_CHANNEL_OPENED 708- RFCOMM: support L2CAP ERTM. Callbacks passed to rfcomm_enable_l2cap_ertm() are used to manage ERTM buffers 709 710### Added 711- L2CAP: emit L2CAP_EVENT_ERTM_BUFFER_RELEASED if ERTM buffer not needed/used anymore 712- L2CAP: add fcs_option to ERTM config l2cap_ertm_config_t 713- HCI: validate advertisement data length field when generating GAP_EVENT_ADVERTISING_REPORT 714- ad_parser: validate data element length fields in ad_iterator_has_more 715- Raspberry Pi 3 A+/B+ port in port/raspi, starts without power cycle 716 717### Fixed 718- HCI: release outgoing buffer on disconnect if waiting to send another ACL fragment 719- POSIX: use correct baudrate enums for baud rates higher than 921600 (Linux) 720- Crypto: directly process queued crypto operation on HCI result 721 722--- 723 724## Changes December 2018 725 726### Added 727- SM: generate and store ER / IR keys in TLV, unless manually set by application 728- hci_dump: support PacketLogger or BlueZ format output via SEGGER RTT Channel 1 Up 729 730### Fixed 731- SM: fix internal buffer overrun during random address generation 732 733## Changes November 2018 734 735### Added 736- GAP: gap_le_connection_interval provides connection interval for conn handle 737- Nordic SPP Service Server: GATT service that emulates a serial port over BLE based on Nordic Semiconductor documentation. 738- uBlox SPP Service Server: GATT service that emulates a serial port over BLE based on uBlox documentation. 739- SM: ENABLE_LE_CENTRAL_AUTO_ENCRYPTION triggers automatic encryption on connect to bonded devices 740- SM: generate and store ER / IR keys in TLV, unless manually set by application 741 742### Fixed 743- SM: prevent random address updates if gap_random_address_set was used 744- SM: fix internal buffer overrun that can cause storing of bonding information to fail 745- SM: ignore Slave Security Request after sending own Pairing Request 746- L2CAP: fix use after free on disconnect if ERTM is enabled 747- HFP: Handle multiple commands/responses in single RFCOMM packet 748- Memory Pools: clear all buffers before use 749 750--- 751 752## Changes October 2018 753 754### Added 755- SDP Server: queue incoming connections when already connected instead of rejecting them 756- GAP: Support enter/exit sniff mode via gap_sniff_mode_enter/exit. gap_set_default_link_policy_settings is needed to enable sniff mode in general. 757- HIDS Device: GATT service that exposes HID reports intended for HID Devices, like keyboard and mouse. 758 759### Fixed 760- HCI: fix bug in gap_inquiry_stop that triggered additional GAP_EVENT_INQUIRY_COMPLETE instead of stopping the inquiry 761- L2CAP: fix issue with outgoing connection before read remote supported complete when other channels exist 762- L2CAP ERTM: allow SDU of szie MPS in first packet that contains L2CAP SDU Length 763- L2CAP ERTM: fix memory corruption triggered if local_mtu > mps 764- L2CAP ERTM: fix outgoing fragment management 765- HFP: decline incoming RFCOMM connection after outgoing connection was started 766- AVRCP: fix crash on disconnect of connection established by remote 767 768--- 769 770## Changes September 2018 771 772### Fixed 773- HCI: Error creating outgoing connection (e.g. Connection Limit Exceeded) now handled 774- L2CAP: Error creating outgoing connection (e.g. Connection Limit Exceeded) now handled 775- L2CAP: Evaluate 'can send now' on HCI Disconnect as ACL buffers in Bluetooth Controller have been used for the closed connection are freed implicitly 776- L2CAP: Check can send now before sending extended information requeste needed for ERTM mode 777- L2CAP: Use valid signaling identifier for L2CAP Connection Parameter Update Request 778- RFCOMM: Trigger l2cap request to send on rfcomm credits when client is waiting to sendtrigger l2cap request to send on rfcomm credits when client is waiting to send 779- RFCOMM: Avoid use-after-free on channel finalize 780- GATT Client: stop timer on disconnect - fixes use after free / crash 781 782### Added 783- A2DP Source: Support stream reconfiguration (a2dp_source_reconfigure_stream_sampling_frequency) 784- 3rd-party: yxml is used for PBAP vCard list parsing 785- cc256xC: new v1.1 init scripts 786 787--- 788 789## Changes August 2018 790 791### Added 792- PBAP: added pbap_get_phonebook_size() to get phonebook entry count 793 794### Fixed 795- GATT Server: Allow enable Notifications/Indication with Write Command. Fixes issue with some Android devices. 796- SM: fix pairing for Secure Connections with Bonding if remote sends additional keys 797- SM: drop LTK flag from Pairing Response for Secure Connections 798- L2CAP: fix emitted L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST 799 800## Changes June 2018 801 802### Added 803- btstack_audio.h: application level API for audio playback and recording 804- embedded/hal_audio.h: low-level API for audio playback and recording 805- HID Device: hid_device_connect(..) function 806- ESP32: implement hal_audio 807- DA14585: support for Dialog Semiconductor DA14585 LE-only controller 808- Raspberry Pi 3 + Raspberry Pi Zero W port in port/raspi 809 810### Changed 811- Errata 10734: 812 - SM: Generate new EC Public Keypair after each pairing 813 - SM: Abort failure with DHKEY_CHECK_FAILED if received public key is invalid (instead of unspecified error) 814- btstack.h: only include classic headers if ENABLE_CLASSIC is defined 815- windows: ignore virtual Bluetooth adapter provided by VMware 816- Replaced HCI_PACKET_BUFFER_SIZE with HCI_INCOMING_PACKET_BUFFER_SIZE and HCI_OUTGOING_PACKET_BUFFER_SIZE 817 818--- 819 820## Changes June 2018 821 822### Fixed 823- HFP: Fix Wide Band Speech bit in SDP record for both HF/AG. Missing bit prevents macOS from using mSBC 824- ATT Server: send ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE with status ATT_HANDLE_VALUE_INDICATION_DISCONNECT on disconnect 825- AVRCP Controller: fix parsing of now playing info 826 827### Changed 828- ATT Server: ATT_HANDLE_VALUE_INDICATION_DISCONNECT is delivered to service handler if registered 829 830### Added 831- ATT Server: packet handler field added to att_service_handler_t to receive: connect/disconnect, atu exchange, indication complete 832 833--- 834 835## Changes May 2018 836 837### Added 838- GAP: re-encrypt outgoing connection if bonded 839- ATT Server: wait until re-encryption is complete 840- GATT Client: wait until re-encryption is complete 841- ATT Server: added att_server_request_to_send_notification and att_server_request_to_send_indication 842- GATT Client: if ENABLE_GATT_CLIENT_PAIRING, GATT Client starts pairing and retry operation on security error 843 844### Changed 845- ATT Server: att_server_register_can_send_now_callback is deprecated, use att_server_request_to_send_notification/indication instead 846 847### Fixed 848- SM: Fix LE Secure Connection pairing in Central role 849- le_device_db_tlv: fix seq nr management 850- SM: improve le_device_db lookup and storing of IRK 851- GATT Server: fix lookup for Client Characteristic Configuration in services with multiple Characteristics 852- RFCOMM: emit channel closed on HCI/L2CAP disconnect after sending DISC while expecting UA 853 854--- 855 856## Changes April 2018 857 858### Added 859- Crypto: btstack_crypo.h provides cryptographic functions for random data generation, AES128, EEC, CBC-MAC (Mesh) 860- SM: support pairing using Out-of-Band (OOB) data with LE Secure Connections 861- Embedded: support btstack_stdin via SEGGER RTT 862 863### Changed 864- att_db_util: added security requirement arguments to characteristic creators 865- SM: use btstack_crypto for cryptographpic functions 866- GAP: security level for Classic protocols (asides SDP) raised to 2 (encryption) 867 868### Fixed 869- HFP: fix answer call command 870- HCI: fix buffer overrun in gap_inquiry_explode 871- SDP: free service record item on sdp_unregister_service 872 873## Changes March 2018 874 875### Added 876- GAP: allow to limit number of connections in LE Peripheral role with gap_set_max_number_peripheral_connections 877- ATT Server: support for delayed ATT read response, see example/att_delayed_read_response.c 878- ATT Server: allow to specify security requirements seperately for read/writes. .h files need to be regenerated 879 880### Fixed 881- RFCOMM: fix infinite loop on L2CAP connection error (regression from 4c3eeed1) 882- HSP HS: accept incomming SCO connection 883- SM: fix iteration over LE Device DB entries for bonding and address resolving 884- SM: store pairing information only if both devices have requested bonding 885 886--- 887 888## Changes February 2018 889 890### Added 891- GATT Client: gatt_client_request_can_write_without_response_event() causes GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE 892- SM: new event SM_EVENT_PAIRING_COMPLETE 893- GAP: support iteration over stored Classic link keys: gap_link_key_iterator_init, gap_link_key_iterator_get_next, gap_link_key_iterator_done 894- GAP: add gap_delete_all_link_keys 895 896### Changed 897- GATT Client: round robin for multiple connections 898- ATT Dispatch: round robin for ATT Server & GATT Client 899- L2CAP: round robin for all L2CAP channels (fixed and dynamic) 900- btstack_link_key_db: addition functions for link key iteration 901- GAP: LE scanning enabled not reset on HCI Reset -> can be enabled before HCI Power Up 902- CSR: set all keys in psram instead of default 903 904### Fixed 905- tc3556x: fix startup after baud rate change 906 907--- 908 909## Changes January 2018 910 911### Added 912- Port for Windows with Zephyr HCI Firmware connected via serial port 913- em9304: upload patch containers during HCI bootup 914- Makefile for STM32-F4Discovery port 915- support for console out via SEGGER RTT 916- LE Data Channels example in BTstack and [iOS example on GitHub](https://github.com/bluekitchen/CBL2CAPChannel-Demo) 917- LE Streamer Client can send as fast as possbile as well 918- L2CAP: option to limit ATT MTU via l2cap_set_max_le_mtu 919 920### Changed 921- HCI: allow to set hci_set_master_slave_policy (0: try to become master, 1: accept slave) 922- GAP: gap_set_connection_parameters includes scan interval and window params 923- GATT Client: GATT_EVENT_MTU indicates max MTU 924- ATT DB Util: attribute handle is returned for new Services and Characteristics 925 926### Fixed 927- Windows: retry serial port operations if not all bytes have been read/written 928- HFP: avoid buffer overflows setting up messages 929- SBC Decoder: improved error handling for invalid SBC audio data 930- GAP: fix Connection Parameter Response in Central role 931- ATT DB Util: update pointer to database in case of realloc 932- GATT Client: set UUID16 field if 16-bit UUID is stored as UUID128 933- GAP: release HCI Connnection after gap_le_conne 934- ATT: Exchanged MTU is propagate to ATT Server and GATT Client 935 936--- 937 938## Changes December 2017 939 940### Added 941- Introduced btstack_network.h network interface abstraction 942- btstack_network_posix implementation using Linux tun/tap interface 943- WICED: support for btstack_stdin (HAVE_STDIN) 944- GATT Server: Writes to GATT Client Characteristic Configuration are stored in TLV and restored on reconnect. The db.h file generated from db.gatt needs to be re-created. 945- TLV: global TLV instance available via btstack_tlv_get_instance() (src/btstack_tlv.h) 946- TLV: POSIX implementation that appends to a file on disk (platform/posix/btstack_tlv_posix.c 947- LE Device DB TLV: overwrite oldest entry if no free entries available 948- SM: allow to set fixed passkey in display role using sm_use_fixed_passkey_in_display_role 949- Example/hid_host_demo with HID parser and support for basic US keyboard layout 950- EM9304: custom HCI Transport implementation for EM9304 on top of btstack_em9304_spi.h platform abstraction only requires hal_em9304_spi.h to be implemented for new ports 951- Port for Apollo2 MCU with EM9304 (ports/apollo2-em9304) 952 953### Changed 954- panu_demo: uses btstack_network.h now 955- WICED: configure printf to replace Linefeed with CRLF 956- SBC: split btstack_sbc_bludroid.c into seperate encoder and decoder implementations 957 958### Fixed 959- RFCOMM: support connection requests during connection failure 960- L2CAP: support connection requests during connection failure 961- L2CAP: fix default remote MTU as 672 instead of 48 (Minimal MTU) 962- HCI: avoid double free during halting 963- SM: fixed reconnect using legacy pairing in slave role 964 965 966