CHPP Release Notes

A summary of notable changes is provided in the form of release notes. Dates are provided as yyyy-mm-dd. Note that this is not meant to be a detailed changelog; for a detailed change list, please refer to git commits.

2020-03-04 (4c668b3)

Initial release of CHPP.

  • CHPP transport and app layers
  • Loopback testing service

2020-07-28 (7cebe57)

This release enables service integration with WWAN / WiFi / GNSS devices based on the CHRE PAL API.

  • New functionality

    • Reset and reset-ack implementation to allow either peer to initialize the other (e.g., upon boot)
    • Discovery service to provide a list of services
    • Discovery client to match clients with discovered services
    • Standard WWAN service based on the CHRE PAL API
    • Standard WiFi service based on the CHRE PAL API
    • Standard GNSS service based on the CHRE PAL API
    • Standard WWAN client based on the CHRE PAL API

  • Updates and bug fixes to existing layers, including

    • Better logging to assist verification and debugging
    • Error replies are sent over the wire for transport layer errors
    • Over-the-wire preamble has been corrected (byte shifting error)

  • API and integration changes

    • App layer header now includes an error code
    • App layer message type now occupies only the least significant nibble (LSN). The most significant nibble (MSN) is reserved
    • chppPlatformLinkSend() now returns an error code instead of a boolean
    • Added initialization, deinitialization, and reset functionality for the link layer (see link.h)
    • Condition variables functionality needs to be supported alongside other platform functionality (see chpp/platform/)
    • Name changes for the logging APIs

2020-08-07 (0b41306)

This release contains bug fixes as well as the loopback client.

  • New functionality

    • Loopback client to run and verify a loopback test using a provided data buffer

  • Cleanup and bug fixes

    • Corrected sequence number handling
    • Updated log messages
    • More accurate casting into enums

2020-08-27 (8ab5c23)

This release contains additional clients, a virtual link layer for testing (e.g., using loopback), and several important bug fixes.

  • New functionality

    • Basic implementation of the standard WiFi client based on the CHRE PAL API
    • Basic implementation of the standard GNSS client based on the CHRE PAL API
    • Virtual link layer that connects CHPP with itself on Linux to enable testing, including reset, discovery, and loopback

  • Cleanup and bug fixes

    • Client implementation cleanup
    • Client-side handling of close responses
    • Reset / reset-ack handshaking mechanism fixed
    • Loopback client fixed
    • Enhanced log messages
    • Service command #s are now sequential

  • API and integration changes

    • Platform-specific time functionality (platform_time.h)

2020-10-01 (95829e3)

This release updates client functionality using the parser, adds a transport-layer loopback mechanism for testing and debugging, and includes several important bug fixes.

  • New functionality

    • Parser for CHPP -> CHRE Data Structure Decoding
    • Completed client functionality using parser-generated functions
    • Transport-layer-loopback client and service. The Transport-layer loopback ignores app layer functionality and state, as well as checksums and sequence numbers

  • Cleanup and bug fixes

    • Improved compiler compatibility for MSVC, as well as when enabling additional compiler warning flags
    • Fixed handling of fragmented datagrams
    • Corrected MTU calculation
    • Corrected loopback assert
    • Slimmer OOM logging
    • Parser code and header files were relocated

2021-02-08 (f1d249c)

In addition to enhancements and bug fixes, this release enables error and reset handling and several other features.

  • New functionality

    • ARQ implementation. Note that it is necessary to either implement chppNotifierTimedWait() or a single-threaded workaround as described in QUICKSTART.md to detect timeouts
    • Checksum support via IEEE CRC-32. A sample implementation is provided, but it is expected that most devices have optimized implementations available or may prefer implementations with alternate optimization criteria
    • Timesync functionality and timestamp offset correction for WiFi and WWAN measurements
    • Reset handling throughout the transport layer, clients, and services, opening and recovering state as needed
    • WiFi RTT client and service support
    • Multiple loopback client support
    • Transport-layer-loopback client validates response and returns the result
    • Support for pseudo-opening services at the client, so they appear always available
    • Correct responses generated at clients when async requests fail at services

  • Cleanup and bug fixes

    • Client and service fixes including length and bound checks, missing implementations
    • Parser fixes including empty pointers set to null, compatibility with processors lacking unaligned access support
    • Stability fixes throughout CHPP and tests
    • Improved compiler compatibility for C99+ and pre-C99 systems (even though CHPP does not officially support pre-C99)
    • Updated documentation and logging

2021-03-25 (f908420)

This release updates the built-in timesync and checksum functionality and addresses bugs and compatibility issues.

  • Updated functionality

    • Timesync is redesigned to become non-blocking
    • Outgoing checksums are enabled by default
    • An updated sample CRC32 implementation is provided (It is still expected that devices that have existing, optimized implementations use their own)
    • Client deinitialization and reset support

  • Cleanup and bug fixes

    • Logging updates, including reset reasoning, avoiding %s for compatibility
    • Stability fixes and cleanup throughout CHPP and tests, including the reopening flow, permanent_failure state, and a memory leak
    • Testing improvements

2021-05-24 (c9bfae3)

This release enables better identification of end-of-packets as well as addressing bugs and compatibility issues.

  • Updated functionality

    • Rx timeout detection
    • Rx MTU enforcement
    • Support for Rx end-of-packet notifications from the link layer (optional, platform dependent)

  • Cleanup and bug fixes

    • Reset functionality cleanup, including updating the functionality of CHPP_TRANSPORT_MAX_RETX and CHPP_TRANSPORT_MAX_RESET to reflect their intent accurately
    • Pseudo-open clients remain pseudo-open after open failures
    • Fixed reopen failures after transport reset
    • Added missing WiFi ranging service response
    • Memory allocation and initialization improvements
    • Mutex handling improvements
    • Compatibility fixes
    • Testing improvements

2021-06-17 (this)

This release adds request timeout support at the client and addresses several bugs and compatibility issues throughout CHPP, including fixing open-state tracking at the service. Note that with the corrected open-state tracking, it is essential for services to correctly implement the close() PAL API so that it disables any ongoing requests and returns to a clean state.

  • Updated functionality

    • Client request timeout support

  • Cleanup and bug fixes

    • Service open-state tracking
    • Memory handling fixes
    • Added GNSS passive location listener service response
    • Enforced error code requirements on service responses
    • Fixed ARQ handling of duplicate packets
    • Client request/response state refactoring
    • Client registration cleanup
    • Reset handling fixes
    • Testing improvements