Re: [PATCH gwproxy v12 6/8] gwproxy: Introduce --dns-server and --raw-dns

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

On Fri, Sep 19, 2025 at 01:47:28AM +0700, Alviro Iskandar Setiawan wrote:
> While in there, plug the new DNS resolver data structure into struct
> gwp_wrk and initialize it.

I don't see any guard against the io_uring usage. Note that you only
add this feature support for epoll. Did you test and verify that your
feature addition doesn't break the io_uring event loop?

> @@ -228,6 +238,12 @@ static int parse_options(int argc, char *argv[], struct gwp_cfg *cfg)
>  		case 'p':
>  			cfg->pid_file = optarg;
>  			break;
> +		case 'j':
> +			cfg->dns_servers = optarg;
> +			break;
> +		case 'r':
> +			cfg->use_raw_dns = !!atoi(optarg);
> +			break;
>  		default:
>  			fprintf(stderr, "Unknown option: %c\n", c);
>  			show_help(argv[0]);

Maybe you can add:

	if (cfg->use_raw_dns && !strcmp(cfg->event_loop, "io_uring)) {
		fprintf(stderr, ERR_WRAP "Error: The raw DNS feature is currently not supported with the io_uring event loop\n" ERR_WRAP);
		goto einval;
	}

or something similar to avoid io_uring being run with the experimental
feature that's not available for it yet.

> +
> +	if (cfg->use_raw_dns) {
> +		r = gwp_ctx_init_raw_dns(w);
> +		if (r < 0) {
> +			pr_err(&ctx->lh, "Failed to initialize raw DNS: %s", strerror(-r));
> +			goto out_err;
> +		}
> +	}

The problem with this initialization is that, it does not take care of
the io_uring case. It'll probably crash as the io_uring code still
thinks it's allowed to use ctx->dns.

-- 
Ammar Faizi