1 unstable release

new 0.1.0	Dec 22, 2024

#20 in #dns-lookup

MPL-2.0 license

22KB
501 lines

dnsur

An asynchronous DNS stub resolver.

Motivation

The monoio async runtime does not ship with an asynchronous DNS resolver, and rather relies on a threadpool to handle the blocking calls (like most other runtimes). This library aims to do the resolution in an async manner, including the file system access (using io_uring).

Details

/etc/hosts and /etc/resolv.conf are parsed to build the configuration.
The entries in the hosts are tried first, and if not present, the nameservers from resolv.conf will be queried.
Querying of the nameservers is done sequentially (i.e. we query the second nameserver only if the first one has failed).
A and AAAA records are queried concurrently.
Default UDP buffer size is 1232 bytes.

Non-standard behavior

limitation	glibc	dnsur
`nameserver`	3	unlimited
`timeout`	30	`u64::MAX`
`ndots`	15	`u8::MAX`
`attempts`	5	`u8::MAX`

TODO

Support for rotate

Status

Hic Sunt Dracones

License

Mozilla Public License Version 2.0. See the LICENSE file for details.

Acknowledgement

This library is inspired by async-dns

Dependencies

~6–16MB
~172K SLoC