DDNS

ddns provides DNS discovery and resolver support for DHTTP applications. The published Cargo package is dyns, and the library target remains ddns.

ddns exposes backend implementations in ddns::h3, ddns::http, and ddns::mdns, while ddns::resolvers and ddns::publishers act as facades for re-exports and aggregate helper types.

ddns = { package = "dyns", version = "0.4.0" }

Crate layout

Features

The default feature set is empty.

Backend types live under the resolvers / publishers facades whenever their backend feature is enabled. The aggregate Resolvers and endpoint-publication helper types are separately gated by the resolvers and publishers features.

Bootstrap constants

build.rs generates resolver defaults exposed from ddns::resolvers:

These production fallbacks are used when the corresponding compile-time environment variables are unset.

Quick start

Resolver chain

Enable the resolver aggregation surface and build a chain explicitly:

use ddns::resolvers::Resolvers;
use futures::StreamExt;

#[tokio::main]
async fn main() -> Result<(), ddns::resolvers::ResolversError> {
    let resolvers = Resolvers::builder().system().build();
    let mut endpoints = resolvers.lookup("demo.example.dhttp.net").await?;

    while let Some((source, endpoint)) = endpoints.next().await {
        println!("{source:?}: {endpoint}");
    }

    Ok(())
}

mDNS discovery

use ddns::{mdns::service::Mdns, resolvers::DHTTP_MDNS_SERVICE};
use futures::StreamExt;

#[tokio::main(flavor = "current_thread")]
async fn main() -> std::io::Result<()> {
    let mdns = Mdns::new(
        DHTTP_MDNS_SERVICE,
        std::net::Ipv4Addr::LOCALHOST.into(),
        "lo0",
    )?;
    let mut discoveries = mdns.discover();

    while let Some((source, packet)) = discoveries.next().await {
        println!("received packet from {source}: {packet}");
    }

    Ok(())
}

Runnable examples:

cargo run --example mdns_discover --features mdns -- --ip 127.0.0.1 --device lo0
cargo run --example mdns_query --features mdns -- --ip 192.168.5.156 --device en0
cargo run --example query -- --server-ca /path/to/root.crt --host nat.genmeta.net
cargo run --example publish --features h3 -- \
  --server-ca /path/to/root.crt \
  --client-name demo.example.dhttp.net \
  --client-cert /path/to/demo.example.dhttp.net.pem \
  --client-key /path/to/demo.example.dhttp.net.key \
  --host demo.example.dhttp.net \
  --addr 192.168.1.100:8080,192.168.1.101:8080

See examples/README.md for example CLI parameters and response decoding notes.