mini-c-ares

A fork of rust-c-ares, which provides a minimal Rust wrapper for the c-ares library, for asynchronous DNS requests.

Most users should likely prefer c-ares-resolver, which offers a much simpler API and more functionality.

Documentation

• API documentation is here.

Contributing

Contributions should be sent to the upstream repo rust-c-ares!

lib.rs:

A safe wrapper for the c-ares library.

This crate is a fairly faithful wrapper of c-ares; which is to say that it preserves some of the complexity of using the underlying library. If you just want to make a DNS query, you should probably prefer the c-ares-resolver crate, which does the hard work for you.

Direct usage of this crate requires you to pay attention to c-ares as it tells you which file descriptors it cares about, and to poll for activity on those file descriptors. This likely requires you to have an event loop or similar with which to integrate.

Still here? Usage of this crate is as follows:

• Create a Channel.

• Make queries on the Channel. Queries all take callbacks, which will be called when the query completes.

• Have c-ares tell you what file descriptors to listen on for read and / or write events. You can do this either by providing a callback, which is called whenever the set of interesting file descriptors changes, or by querying the Channel directly either with get_sock() or with fds().

• Do as c-ares asks. That is, listen for the events that it requests, on the file descriptors that it cares about.

• When a file descriptor becomes readable or writable, call either process_fd() or process() on the Channel to tell c-ares what has happened.

• If you have queries pending and don't see events happening, you still need to call either process_fd() or process() at some point anyway - to give c-ares an opportunity to process any requests that have timed out.

Complete examples showing how to use the library can be found here.