netifd: fix IPv6 Link-local DNS server

interface name must be added to Link-local IPv6
DNS servers, otherwise they are unusable.

Signed-off-by: Ulrich Weber <uw@ocedo.com>

diff --git a/interface-ip.c b/interface-ip.c
index d5a3832..6f42015 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -18,6 +18,7 @@
 
 #include <limits.h>
 #include <arpa/inet.h>
+#include <netinet/in.h>
 
 #include "netifd.h"
 #include "device.h"
@@ -1027,7 +1028,7 @@ interface_add_dns_search_list(struct interface_ip_settings *ip, struct blob_attr
 }
 
 static void
-write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip)
+write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip, const char *dev)
 {
        struct dns_server *s;
        struct dns_search_domain *d;
@@ -1039,7 +1040,10 @@ write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip)
                if (!str)
                        continue;
 
-               fprintf(f, "nameserver %s\n", str);
+               if (s->af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&s->addr))
+                       fprintf(f, "nameserver %s%%%s\n", str, dev);
+               else
+                       fprintf(f, "nameserver %s\n", str);
        }
 
        vlist_simple_for_each_element(&ip->dns_search, d, node) {
@@ -1074,9 +1078,9 @@ interface_write_resolv_conf(void)
                        continue;
 
                fprintf(f, "# Interface %s\n", iface->name);
-               write_resolv_conf_entries(f, &iface->config_ip);
+               write_resolv_conf_entries(f, &iface->config_ip, iface->ifname);
                if (!iface->proto_ip.no_dns)
-                       write_resolv_conf_entries(f, &iface->proto_ip);
+                       write_resolv_conf_entries(f, &iface->proto_ip, iface->ifname);
        }
        fflush(f);
        rewind(f);