libp2p-mdns 0.42.0

Implementation of the libp2p mDNS discovery method
Documentation
# 0.42.0

- Update to `libp2p-core` `v0.38.0`.

- Update to `libp2p-swarm` `v0.41.0`.

- Update to `if-watch` `3.0.0` and both rename `TokioMdns` to `Behaviour` living in `tokio::Behaviour`,
and move and rename `Mdns` to `async_io::Behaviour`. See [PR 3096].

- Remove the remaning `Mdns` prefixes from types as per [discussion 2174].
  I.e the `Mdns` prefix has been removed from various types like `MdnsEvent`.
  Users should prefer importing the mdns protocol as a module (`use libp2p::mdns;`),
  and refer to its types via `mdns::`. For example: `mdns::Behaviour` or `mdns::Event`.

- Replace `GenMdns`'s `NetworkBehaviour` implemention `inject_*` methods with the new `on_*` methods.
  See [PR 3011].

- Use `trust-dns-proto` to parse DNS messages. See [PR 3102].

- Update `rust-version` to reflect the actual MSRV: 1.62.0. See [PR 3090].

[discussion 2174]: https://github.com/libp2p/rust-libp2p/discussions/2174
[PR 3096]: https://github.com/libp2p/rust-libp2p/pull/3096
[PR 3011]: https://github.com/libp2p/rust-libp2p/pull/3011
[PR 3102]: https://github.com/libp2p/rust-libp2p/pull/3102
[PR 3090]: https://github.com/libp2p/rust-libp2p/pull/3090

# 0.41.0

- Remove default features. If you previously depended on `async-io` you need to enable this explicitly now. See [PR 2918].

- Update to `libp2p-core` `v0.37.0`.

- Update to `libp2p-swarm` `v0.40.0`.

- Fix a bug that could cause a delay of ~10s until peers would get discovered when using the tokio runtime. See [PR 2939].

- Removed the `lazy_static` dependency. See [PR 2977].

- Update to `if-watch` `v2.0.0` and thus the `async` method `Mdns::new` and `TokioMdns::new` becomes synchronous. See [PR 2978].

[PR 2918]: https://github.com/libp2p/rust-libp2p/pull/2918
[PR 2939]: https://github.com/libp2p/rust-libp2p/pull/2939
[PR 2977]: https://github.com/libp2p/rust-libp2p/pull/2977
[PR 2978]: https://github.com/libp2p/rust-libp2p/pull/2978

# 0.40.0

- Update to `libp2p-swarm` `v0.39.0`.

- Allow users to choose between async-io and tokio runtime
  in the mdns protocol implementation. `async-io` is a default
  feature, with an additional `tokio` feature  (see [PR 2748])

- Fix high CPU usage with Tokio library (see [PR 2748]).

- Update to `libp2p-core` `v0.36.0`.

[PR 2748]: https://github.com/libp2p/rust-libp2p/pull/2748

# 0.39.0

- Update to `libp2p-swarm` `v0.38.0`.
- Update to `if-watch` `v1.1.1`.

- Update to `libp2p-core` `v0.35.0`.

# 0.38.0

- Update to `libp2p-core` `v0.34.0`.

- Update to `libp2p-swarm` `v0.37.0`.

# 0.37.0

- Update to `libp2p-core` `v0.33.0`.

- Update to `libp2p-swarm` `v0.36.0`.

# 0.36.0

- Update to `libp2p-swarm` `v0.35.0`.

# 0.35.0 [2022-02-22]

- Update to `libp2p-core` `v0.32.0`.

- Update to `libp2p-swarm` `v0.34.0`.

- Merge NetworkBehaviour's inject_\* paired methods (see PR 2445).

[PR 2445]: https://github.com/libp2p/rust-libp2p/pull/2445

# 0.34.0 [2022-01-27]

- Update dependencies.

- Use a random alphanumeric string instead of the local peer ID for mDNS peer
  name (see [PR 2311]).

  Note that previous versions of `libp2p-mdns` expect the peer name to be a
  valid peer ID. Thus they will be unable to discover nodes running this new
  version of `libp2p-mdns`.

- Migrate to Rust edition 2021 (see [PR 2339]).

- Fix generation of peer expiration event and listen on specified IP version (see [PR 2359]).

- Support multiple interfaces (see [PR 2383]).

[PR 2339]: https://github.com/libp2p/rust-libp2p/pull/2339

[PR 2311]: https://github.com/libp2p/rust-libp2p/pull/2311/

[PR 2359]: https://github.com/libp2p/rust-libp2p/pull/2359

[PR 2383]: https://github.com/libp2p/rust-libp2p/pull/2383

# 0.33.0 [2021-11-16]

- Update dependencies.

# 0.32.0 [2021-11-01]

- Make default features of `libp2p-core` optional.
  [PR 2181]https://github.com/libp2p/rust-libp2p/pull/2181

- Update dependencies.

- Add support for IPv6. To enable set the multicast address
  in `MdnsConfig` to `IPV6_MDNS_MULTICAST_ADDRESS`.
  See [PR 2161] for details.

- Prevent timers from firing at the same time. See [PR 2212] for details.

[PR 2161]: https://github.com/libp2p/rust-libp2p/pull/2161/
[PR 2212]: https://github.com/libp2p/rust-libp2p/pull/2212/

# 0.31.0 [2021-07-12]

- Update dependencies.

# 0.30.2 [2021-05-06]

- Fix discovered event emission.
  [PR 2065]https://github.com/libp2p/rust-libp2p/pull/2065

# 0.30.1 [2021-04-21]

- Fix timely discovery of peers after listening on a new address.
  [PR 2053]https://github.com/libp2p/rust-libp2p/pull/2053/

# 0.30.0 [2021-04-13]

- Derive `Debug` and `Clone` for `MdnsConfig`.

- Update `libp2p-swarm`.

# 0.29.0 [2021-03-17]

- Introduce `MdnsConfig` with configurable TTL of discovered peer
  records and configurable multicast query interval. The default
  query interval is increased from 20 seconds to 5 minutes, to
  significantly reduce bandwidth usage. To ensure timely peer
  discovery in the majority of cases, a multicast query is
  initiated whenever a change on a network interface is detected,
  which includes MDNS initialisation at node startup. If necessary
  the MDNS query interval can be reduced via the `MdnsConfig`.
  The `MdnsService` has been removed from the public API, making
  it compulsory that all uses occur through the `Mdns` `NetworkBehaviour`.
  An `MdnsConfig` must now be given to `Mdns::new()`.
  [PR 1977]https://github.com/libp2p/rust-libp2p/pull/1977.

- Update `libp2p-swarm`.

# 0.28.1 [2021-02-15]

- Update dependencies.

# 0.28.0 [2021-01-12]

- Update dependencies.

# 0.27.0 [2020-12-17]

- Update `libp2p-swarm` and `libp2p-core`.

# 0.26.0 [2020-12-08]

- Create multiple multicast response packets as required to avoid
  hitting the limit of 9000 bytes per MDNS packet.
  [PR 1877]https://github.com/libp2p/rust-libp2p/pull/1877.

- Detect interface changes and join the MDNS multicast
  group on all interfaces as they become available.
  [PR 1830]https://github.com/libp2p/rust-libp2p/pull/1830.

- Replace the use of macros for abstracting over `tokio`
  and `async-std` with the use of `async-io`. As a result
  there may now be an additional reactor thread running
  called `async-io` when using `tokio`, with the futures
  still being polled by the `tokio` runtime.
  [PR 1830]https://github.com/libp2p/rust-libp2p/pull/1830.

# 0.25.0 [2020-11-25]

- Update `libp2p-swarm` and `libp2p-core`.

# 0.24.0 [2020-11-09]

- Update dependencies.

# 0.23.0 [2020-10-16]

- Update `libp2p-swarm` and `libp2p-core`.

- Double receive buffer to 4KiB. [PR 1779]https://github.com/libp2p/rust-libp2p/pull/1779/files.

# 0.22.0 [2020-09-09]

- Update `libp2p-swarm` and `libp2p-core`.

# 0.21.0 [2020-08-18]

- Bump `libp2p-core` and `libp2p-swarm` dependencies.

- Allow libp2p-mdns to use either async-std or tokio to drive required UDP
  socket ([PR 1699]https://github.com/libp2p/rust-libp2p/pull/1699).

# 0.20.0 [2020-07-01]

- Updated dependencies.

# 0.19.2 [2020-06-22]

- Updated dependencies.