Re: [PATCH gwproxy v8 2/2] gwproxy: refactor code base to add experimental raw DNS backend

[Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>]

On Fri, Aug 29, 2025 at 2:56 PM Ahmad Gani wrote:
> +#ifdef CONFIG_RAW_DNS
> +               if (ctx->nr_entries == ctx->entry_cap && realloc_entries(ctx))
> +                       return NULL;
> +
> +               r = __sys_socket(ctx->ns_addr.sa.sa_family, SOCK_DGRAM | SOCK_NONBLOCK, 0);
> +               if (r < 0)
> +                       goto out_free_e;
> +               e->udp_fd = (int)r;
> +
> +               switch (ctx->cfg.restyp) {
> +               case GWP_DNS_RESTYP_PREFER_IPV4:
> +               case GWP_DNS_RESTYP_IPV4_ONLY:
> +                       af = AF_INET;
> +                       break;
> +               case GWP_DNS_RESTYP_PREFER_IPV6:
> +               case GWP_DNS_RESTYP_IPV6_ONLY:
> +                       af = AF_INET6;
> +                       break;
> +               default:
> +                       assert(0);
> +                       goto out_close_fd;
> +               }
> +
> +               txid = (uint16_t)rand();
> +               r = gwdns_build_query(txid, name, af, e->payload, sizeof(e->payload));
> +               if (r < 0)
> +                       goto out_close_fd;
> +               e->payloadlen = (int)r;
> +#endif

        Back to this section again. Isn't one of the advantages of
inventing your own DNS resolver is also to avoid opening and closing a
UDP socket for each DNS query? This design feels wrong, the txid here
means nothing if each query has its own UDP connection. Can't you use
the same UDP socket for all queries?