Re: [PATCH gwproxy v4 4/6] dnslookup: Initial work for implementation of C-ares-like getaddrinfo function

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

On Wed, Aug 06, 2025 at 07:30:08PM +0700, Ahmad Gani wrote:
> Well, dnsparser.c contains pure byte parsing code, so you might want to
> take a look there.

That part is good. You're half way to get there. But that parser doesn't
provide all necessary parts to resolve a domain.

The problem with the current design is the primary interfaces you
provide. They are gw_ares_init(), gw_ares_getaddrinfo(), etc. Those
things do 'full networking setup' which is not suitable for io_uring
pattern.

Let's make a simple rule. No syscalls in the DNS library. An exception
maybe reading /etc/hosts, but you can skip that part for now.

The DNS lib should at least accept:
    - Domain name.
    - Service name (port).
    - Address families to be resolved (AF_INET or AF_INET6).
    - Received bytes from the network.
    - Pointer to recv and send buffer (including their lengths).

The DNS lib should at least generate:
    - Resolved addresses in 'struct gwp_sockaddr' form.
    - Bytes to be sent to the network.

If you provide such interfaces, it can be integrated with all networking
patterns. And that's what we're trying to achieve by inventing our own
library.

I didn't catch this mistake earlier because I only skimmed the code.
Thanks to Alviro for pointing it out yesterday.

You should also now realize that your "gw_ares" design is not compatible
with prep_{recv,send} calls from io_uring. Right?

-- 
Ammar Faizi