iroh 0.92.0 - mDNS improvements

Welcome to a new release of iroh, a library for building direct connections between devices, putting more control in the hands of your users.

We're excited to bring you this release, which includes two feature contributions from external contributors! We're grateful for our growing community and their interest in making iroh as amazing as possible.

This release introduces new features to mDNS discovery: "passive" mode, which allows you to listen for nodes on the local network without publishing your own details, and expiry events that are emitted via the subscribe stream, along with other improvements throughout the codebase!

🌐 mDNS passive mode

Previously, if you wanted to discover other nodes on your local network, you also had to publish your own information. Now, you can listen passively and receive addresses from other nodes without announcing your own.

The default behavior for discovery_local_network is still to launch mDNS discovery in active mode.

Use add_discovery along with MdnsDiscovery::builder to launch mDNS discovery in passive mode:

// Create mDNS discovery with advertising disabled
let mdns_discovery = MdnsDiscovery::builder().advertise(false);

// Create endpoint with mDNS discovery
let endpoint = Endpoint::builder()
    .add_discovery(mdns_discovery)
    .bind()
    .await?;

Thank you to contributor Le-Maz for PR #3403!

🪦 Discovery Expiry Events

Our mDNS implementation, swarm-discovery, supports notifications when a node leaves the network. We now surface that information in the Discovery::subscribe stream!

Previously, the subscribe stream only emitted DiscoveryItems when a node joined the local network. Now, the subscribe stream emits DiscoveryEvent s both when a node is discovered and when it has expired:

// The types of events now emitted by
// the `Discovery::subscribe` stream:
pub enum DiscoveryEvent {
		// emitted when a node is discovered
    Discovered(DiscoveryItem),
    // emitted when a node has expired
    Expired(NodeId),
}

Thanks oscartbeaumont! For more info, check out PR #3409

👷 Additional Improvements

We've included updates that allow configuring the maximum number of TLS tickets (especially useful when making a large number of 0-RTT connections) and added serde support for net_report::Reports.

Thanks to varun-doshi for adding a Deref impl for PublicKey, PR #3438.

Thanks to julianpryde for adding jitter to DNS retries, PR #3447.

Thanks to alx0x10 for some doc improvements, PR #3446.

⚠️ Breaking Changes

• iroh
  • added
    • “passive” mode for mDNS discovery
      • MdnsDiscovery::new(node_id: NodeId) → MdnsDiscovery::new(node_id: NodeId, advertise: bool)
  • changed
    • The subscribe method for the Discovery trait now returns a stream of DiscoveryEvent rather than DiscoveryItem. A discovery event now includes expiry events that notify you when a node that was previously discovered (usually via mDNS) can no longer be found.
      • fn subscribe(&self) -> Option<BoxStream<DiscoveryItem>> → fn subscribe(&self) -> Option<BoxStream<DiscoveryEvent>>

But wait, there's more!

Many bugs were squashed, and smaller features were added. For all those details, check out the full changelog: https://github.com/n0-computer/iroh/releases/tag/v0.92.0.

If you want to know what is coming up, check out the v0.93.0 milestone and v0.99.0 milestone, and if you have any wishes, let us know about the issues! If you need help using iroh or just want to chat, please join us on discord! And to keep up with all things iroh, check out our Twitter, Mastodon, and Bluesky.