Submitting final version of this patch, if we have any activity around
deciding it we want to parse the options more strictly they can be
addressed separately.



- Stefan

On Sun, Apr 30, 2017 at 1:53 PM Stefan Sedich <stefan.sedich@gmail.com>
wrote:

> Currently glibc supports using the RES_OPTIONS environment variable
> to customize the resolv.conf options on a per-process basis, this
> adds the same support to musl
> ---
> Changed in v4:
>   - apply feedback from Alexander
>
>  src/network/resolvconf.c | 48
> ++++++++++++++++++++++++++++++------------------
>  1 file changed, 30 insertions(+), 18 deletions(-)
>
> diff --git a/src/network/resolvconf.c b/src/network/resolvconf.c
> index 4c3e4c4b..16ca395f 100644
> --- a/src/network/resolvconf.c
> +++ b/src/network/resolvconf.c
> @@ -5,6 +5,30 @@
>  #include <string.h>
>  #include <netinet/in.h>
>
> +void __parse_resolv_opts(struct resolvconf *conf, const char *opts)
> +{
> +       char *p, *z;
> +
> +       p = strstr(opts, "ndots:");
> +       if (p && isdigit(p[6])) {
> +               p += 6;
> +               unsigned long x = strtoul(p, &z, 10);
> +               if (z != p) conf->ndots = x > 15 ? 15 : x;
> +       }
> +       p = strstr(opts, "attempts:");
> +       if (p && isdigit(p[9])) {
> +               p += 9;
> +               unsigned long x = strtoul(p, &z, 10);
> +               if (z != p) conf->attempts = x > 10 ? 10 : x;
> +       }
> +       p = strstr(opts, "timeout:");
> +       if (p && (isdigit(p[8]) || p[8]=='.')) {
> +               p += 8;
> +               unsigned long x = strtoul(p, &z, 10);
> +               if (z != p) conf->timeout = x > 60 ? 60 : x;
> +       }
> +}
> +
>  int __get_resolv_conf(struct resolvconf *conf, char *search, size_t
> search_sz)
>  {
>         char line[256];
> @@ -38,24 +62,7 @@ int __get_resolv_conf(struct resolvconf *conf, char
> *search, size_t search_sz)
>                         continue;
>                 }
>                 if (!strncmp(line, "options", 7) && isspace(line[7])) {
> -                       p = strstr(line, "ndots:");
> -                       if (p && isdigit(p[6])) {
> -                               p += 6;
> -                               unsigned long x = strtoul(p, &z, 10);
> -                               if (z != p) conf->ndots = x > 15 ? 15 : x;
> -                       }
> -                       p = strstr(line, "attempts:");
> -                       if (p && isdigit(p[9])) {
> -                               p += 9;
> -                               unsigned long x = strtoul(p, &z, 10);
> -                               if (z != p) conf->attempts = x > 10 ? 10 :
> x;
> -                       }
> -                       p = strstr(line, "timeout:");
> -                       if (p && (isdigit(p[8]) || p[8]=='.')) {
> -                               p += 8;
> -                               unsigned long x = strtoul(p, &z, 10);
> -                               if (z != p) conf->timeout = x > 60 ? 60 :
> x;
> -                       }
> +                       __parse_resolv_opts(conf, line);
>                         continue;
>                 }
>                 if (!strncmp(line, "nameserver", 10) && isspace(line[10]))
> {
> @@ -89,5 +96,10 @@ no_resolv_conf:
>
>         conf->nns = nns;
>
> +       if (!libc.secure) {
> +               const char *opts = getenv("RES_OPTIONS");
> +               if (opts) __parse_resolv_opts(conf, opts);
> +       }
> +
>         return 0;
>  }
> --
> 2.11.0
>
>