-int manager_read_resolv_conf(Manager *m);
-int manager_write_resolv_conf(Manager *m);
-
-DnsServer *manager_set_dns_server(Manager *m, DnsServer *s);
-DnsServer *manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr);
-DnsServer *manager_get_dns_server(Manager *m);
-void manager_next_dns_server(Manager *m);