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

[Ahmad Gani <reyuki@gnuweeb.org>]

On Sat, Sep 6, 2025 at 2:47 PM Alviro Iskandar Setiawan wrote:
> 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?

Mhmmm, you have a point; I'll give some thought to the single UDP socket
approach.

--
Ahmad Gani