[srp] implement `AdvertisingProxy` and define `Dnssd` platform APIs (#9268)

This commit adds a generic SRP Advertising Proxy implementation to
OpenThread core, which uses a set of newly defined `otPlatDnssd`
platform APIs for DNS-SD (mDNS) support on infrastructure network on
a Border Router.

`Srp::Server` provides `ServiceUpdateHandler` callback mechanism that
allows platforms to implement their own advertising proxy function.
While this is still supported, the new generic advertising proxy
implementation makes it easier to port and support the proxy function
on new platforms. The platform needs to provide the DNS-SD platform
APIs, which are designed to be simple and easy to implement.

The `AdvertisingProxy` directly interacts with `Srp::Server` and its
registered `Host` and `Service` entries, tracking whether an entry
has been successfully advertised, is currently being advertised, or
has been replaced by a new registration.

The `AdvertisingProxy` ensures that consecutive SRP updates for the
same host or service are committed on the server in the order they
are received, even if their advertisements are finished in a
different order. This is important for SRP Replication support, as
the server may receive a large number of SRP updates back-to-back for
the same host.

The `AdvertisingProxy` will also register key records for SRP host and
service instance names. This will keep the claim on the name of a
removed entry while its key lease is not expired. It is also used
when an SRP host registration has no off-mesh routable address.

This commit adds a detailed unit test `test_srp_adv_proxy` that
validates the `AdvertisingProxy` under many scenarios. The test
covers a range of cases, including delayed registration callbacks and
timeouts, new registrations replacing outstanding advertisements,
platform DNS-SD state changes and failures, host address changes
adding/removing OMR addresses.
30 files changed
tree: e3dfaba03f507a6be5e69c304cfdc620ba00498a
  1. .github/
  2. doc/
  3. etc/
  4. examples/
  5. include/
  6. script/
  7. src/
  8. tests/
  9. third_party/
  10. tools/
  11. zephyr/
  12. .clang-format
  13. .clang-tidy
  14. .code-spell-ignore
  15. .codecov.yml
  16. .default-version
  17. .gitattributes
  18. .gitignore
  19. .gn
  20. .prettierrc
  21. AUTHORS
  22. BUILD.gn
  23. CMakeLists.txt
  24. CODE_OF_CONDUCT.md
  25. CONTRIBUTING.md
  26. LICENSE
  27. NOTICE
  28. README.md
  29. SECURITY.md
  30. STYLE_GUIDE.md
README.md

OpenThread Build Simulation Docker Coverage Status


What is OpenThread?

OpenThread released by Google is...

...an open-source implementation of the Thread networking protocol. Google Nest has released OpenThread to make the technology used in Nest products more broadly available to developers to accelerate the development of products for the connected home.

...OS and platform agnostic, with a narrow platform abstraction layer and a small memory footprint, making it highly portable. It supports both system-on-chip (SoC) and network co-processor (NCP) designs.

...a Thread Certified Component, implementing all features defined in the Thread 1.3.0 specification, including all Thread networking layers (IPv6, 6LoWPAN, IEEE 802.15.4 with MAC security, Mesh Link Establishment, Mesh Routing) and device roles, as well as Border Router support.

More information about Thread can be found at threadgroup.org. Thread is a registered trademark of the Thread Group, Inc.

Who supports OpenThread?

Getting started

All end-user documentation and guides are located at openthread.io. If you're looking to do things like...

  • Learn more about OpenThread features and enhancements
  • Use OpenThread in your products
  • Learn how to build and configure a Thread network
  • Port OpenThread to a new platform
  • Build an application on top of OpenThread
  • Certify a product using OpenThread

...then openthread.io is the place for you.

Note: For users in China, end-user documentation is available at openthread.google.cn.

If you're interested in contributing to OpenThread, read on.

Contributing

We would love for you to contribute to OpenThread and help make it even better than it is today! See our Contributing Guidelines for more information.

Contributors are required to abide by our Code of Conduct and Coding Conventions and Style Guide.

License

OpenThread is released under the BSD 3-Clause license. See the LICENSE file for more information.

Please only use the OpenThread name and marks when accurately referencing this software distribution. Do not use the marks in a way that suggests you are endorsed by or otherwise affiliated with Nest, Google, or The Thread Group.

Need help?

OpenThread support is available on GitHub: