FT: Fix hostapd_wpa_auth_oui_iter() iteration for multicast packets

When using FT wildcard feature, the inter-AP protocol will send
broadcast messages to discover related APs.

For example,
12/6 16:24:43 FT: Send PMK-R1 pull request to remote R0KH address
    ff:ff:ff:ff:ff:ff
12/6 16:24:43 FT: Send out sequence number request to
    ff:ff:ff:ff:ff:ff

If you have multiple interfaces/BSSs in a single hostapd process,
hostapd_wpa_auth_oui_iter() returned 1 after the first interface was
processed. Iteration in for_each_interface() will be stopped since it
gets a non-zero return value from hostapd_wpa_auth_oui_iter().

Even worse, the packet will not be sent to ethernet because
for_each_interface() returns non-zero value. hostapd_wpa_auth_send_oui()
will then return data_len immediately.

To prevent this, hostapd_wpa_auth_oui_iter() should not return 1 after
any successful transmission to other interfaces, if the dst_addr of
packet is a multicast address.

Signed-off-by: Jinglin Wang <bryanwang@synology.com>
Signed-off-by: MinHong Wang <minhongw@synology.com>

src/ap/wpa_auth_glue.c

@@ -748,7 +748,11 @@ static int hostapd_wpa_auth_oui_iter(struct hostapd_iface *iface, void *ctx)
 					       hostapd_oui_deliver_later,
 					       hapd, NULL);
 
-		return 1;
+		/* If dst_addr is a multicast address, do not return any
+		 * non-zero value here. Otherwise, the iteration of
+		 * for_each_interface() will be stopped. */
+		if (!is_multicast_ether_addr(idata->dst_addr))
+			return 1;
 	}
 
 	return 0;