Re: [PATCH] gweb/gresolv.c: make use of res_ninit optional and subject to __RES

Hi Alex,

> Not all libc implementation have those functions, and the way to determine
> if they do is to check __RES which is explained in resolv.h thusly:
> 
> /*
> * Revision information.  This is the release date in YYYYMMDD format.
> * It can change every day so the right thing to do with it is use it
> * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
> * compare for equality; rather, use it to determine whether your resolver
> * is new enough to contain a certain feature.
> */
> 
> Indeed, it needs to be at least 19991006.
> 
> The portion of the patch that implements a fallback is ported from
> Alpine Linux:
> http://git.alpinelinux.org/cgit/aports/plain/testing/connman/libresolv.patch
> ---
> gweb/gresolv.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
> 
> diff --git a/gweb/gresolv.c b/gweb/gresolv.c
> index 8101d718..9f1477c3 100644
> --- a/gweb/gresolv.c
> +++ b/gweb/gresolv.c
> @@ -879,7 +879,9 @@ GResolv *g_resolv_new(int index)
> resolv->index = index;
> resolv->nameserver_list = NULL;
> 
> +#if (__RES >= 19991006)
> res_ninit(&resolv->res);
> +#endif
> 
> return resolv;
> }
> @@ -920,7 +922,9 @@ void g_resolv_unref(GResolv *resolv)
> 
> flush_nameservers(resolv);
> 
> +#if (__RES >= 19991006)
> res_nclose(&resolv->res);
> +#endif
> 
> g_free(resolv);
> }
> @@ -1024,6 +1028,7 @@ guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
> debug(resolv, "hostname %s", hostname);
> 
> if (!resolv->nameserver_list) {
> +#if (__RES >= 19991006)
> int i;
> 
> for (i = 0; i < resolv->res.nscount; i++) {
> @@ -1043,6 +1048,22 @@ guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
> if (inet_ntop(family, sa_addr, buf, sizeof(buf)))
> g_resolv_add_nameserver(resolv, buf, 53, 0);
> }
> +#else
> +                FILE *f = fopen("/etc/resolv.conf", "r");
> +                if (f) {
> +                        char line[256], *s;
> +                        int i;
> +                        while (fgets(line, sizeof(line), f)) {
> +                                if (strncmp(line, "nameserver", 10) || !isspace(line[10]))
> +                                        continue;
> +                                for (s = &line[11]; isspace(s[0]); s++);
> +                                for (i = 0; s[i] && !isspace(s[i]); i++);
> +                                s[i] = 0;
> +                                g_resolv_add_nameserver(resolv, s, 53, 0);
> +                        }
> +                        fclose(f);
> +                }
> +#endif

we have a bit of coding style issues here. And this should really be a helper function.

Regards

Marcel