dnsmasq: fix using '%' delimiter to scope link local with zone-id

Since long, dnsmasq supports scoping the IPv6 address
with '@<interface-name>'. Since 2.58, it also supports
'%' as delimiter, which is the standard way to specify
the zone-id (rfc6874).

Since 2.73, specifying the scope with '@' as "server"
address is no longer working properly, thus breaking
NetworkManager with dnsmasq >= 2.73.

To work around that, use '%' delimiter. That breaks pre-2.58
users that have a DNS server on a link local address, but that
seems acceptable as that version was released in January 2012.

https://bugzilla.gnome.org/show_bug.cgi?id=764839

1 files changed, 5 insertions, 5 deletions

diff --git a/src/dns-manager/nm-dns-dnsmasq.c b/src/dns-manager/nm-dns-dnsmasq.c
index 460feaaccb..5ead5ecf3b 100644
--- a/src/dns-manager/nm-dns-dnsmasq.c
+++ b/src/dns-manager/nm-dns-dnsmasq.c
@@ -131,18 +131,18 @@ ip6_addr_to_string (const struct in6_addr *addr, const char *iface)
 	char *buf;
 
 	if (IN6_IS_ADDR_V4MAPPED (addr)) {
-		/* inet_ntop is probably supposed to do this for us, but it doesn't */
 		buf = g_malloc (INET_ADDRSTRLEN);
 		nm_utils_inet4_ntop (addr->s6_addr32[3], buf);
 	} else if (!iface || !iface[0] || !IN6_IS_ADDR_LINKLOCAL (addr)) {
 		buf = g_malloc (INET6_ADDRSTRLEN);
 		nm_utils_inet6_ntop (addr, buf);
 	} else {
-		/* If we got a scope identifier, we need use '%' instead of
-		 * '@', since dnsmasq supports '%' in server= addresses
-		 * only since version 2.58 and up
+		/* Need to scope the address with %<zone-id>. Before dnsmasq 2.58,
+		 * only '@' was supported as delimiter. Since 2.58, '@' and '%'
+		 * are supported. Due to a bug, since 2.73 only '%' works properly
+		 * as "server" address.
 		 */
-		buf = g_strconcat (nm_utils_inet6_ntop (addr, NULL), "@", iface, NULL);
+		buf = g_strconcat (nm_utils_inet6_ntop (addr, NULL), "%", iface, NULL);
 	}
 	return buf;
 }