possible patch for implementing split DNS

[Julian Elischer]

Julian Elischer wrote:

> I need some processes to look elsewhere for DNS information from where 
> the rest
> of the system looks.. This patch seems to me a simple solution.
> We over-ride where the resolver looks for resolv.conf using an 
> environment variable.
> This would allow me to reset this to an application specific config 
> file that
> specifies a different server.
>
> Anyone got better ways fo doing this?


oops
patch had a bug..
here's the fixed version (permission checks were screwed up)
%diff -u ./lib/libc/net/res_init.c /tmp/res_init.c
--- ./lib/libc/net/res_init.c   Thu Sep  9 10:42:18 2004
+++ /tmp/res_init.c     Fri Aug 25 15:05:59 2006
@@ -154,6 +154,7 @@
        int nserv = 0;    /* number of nameserver records read from file */
        int haveenv = 0;
        int havesearch = 0;
+       char *conf_path;
 #ifdef RESOLVSORT
        int nsort = 0;
        char *net;
@@ -262,7 +263,10 @@
        (line[sizeof(name) - 1] == ' ' || \
         line[sizeof(name) - 1] == '\t'))
 
-       if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
+       if (issetugid() != 0 || (res_path = getenv("RESOLV_CONF")) == NULL)
+               res_path = _PATH_RESCONF;
+
+       if ((fp = fopen(res_path, "r")) != NULL) {
            /* read the config file */
            while (fgets(buf, sizeof(buf), fp) != NULL) {
                /* skip comments */