Re: [PATCH v2 4/6] tools/misc: xenwatchdogd: add parse_secs()

[Anthony PERARD <anthony.perard@xxxxxxxxx>]

On Fri, Mar 29, 2024 at 11:10:54AM +0000, leigh@xxxxxxxxxxxxx wrote:
> diff --git a/tools/misc/xenwatchdogd.c b/tools/misc/xenwatchdogd.c
> index 2e7f9f51c5..19ec4c5359 100644
> --- a/tools/misc/xenwatchdogd.c
> +++ b/tools/misc/xenwatchdogd.c
> @@ -49,6 +49,18 @@ static void catch_usr1(int sig)
>      done = true;
>  }
>  
> +static int parse_secs(const char *arg, const char *what)
> +{
> +    char *endptr;
> +    unsigned long val;
> +
> +    val = strtoul(arg, &endptr, 0);
> +    if (val > INT_MAX || *endptr != 0)

nit: '\0' would be more accurate       ^ here.
Otherwise, just `*endptr` without "!= 0" would work too.
But comparing a char to a digit feels wrong.

> +     errx(EXIT_FAILURE, "invalid %s: '%s'", what, arg);
> +
> +    return val;
> +}
> +
>  int main(int argc, char **argv)
>  {
>      int id;
> @@ -64,16 +76,11 @@ int main(int argc, char **argv)
>      if (h == NULL)
>       err(EXIT_FAILURE, "xc_interface_open");
>  
> -    t = strtoul(argv[1], NULL, 0);
> -    if (t == ULONG_MAX)
> -     err(EXIT_FAILURE, "strtoul");
> +    t = parse_secs(argv[optind], "timeout");
>  
>      s = t / 2;
> -    if (argc == 3) {
> -     s = strtoul(argv[2], NULL, 0);
> -     if (s == ULONG_MAX)
> -         err(EXIT_FAILURE, "strtoul");
> -    }
> +    if (argc == 3)
> +     s = parse_secs(argv[optind], "sleep");

This is parsing the wrong value here, should it be +1 to parse the sleep
argument instead of the timeout argument a second time.

Also, are you sure you want to start using "optind" here? It's a
variable used by getopt(), but we don't use it yet. It almost feel like
"optind" happen to be set to 1 by luck.


Thanks,

-- 
Anthony PERARD