+ case OVS_KEY_ATTR_SKB_MARK:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) && !defined(CONFIG_NETFILTER)
+ if (nla_get_u32(ovs_key) != 0)
+ return -EINVAL;
+#endif
+ break;
+
+ case OVS_KEY_ATTR_IPV4_TUNNEL:
+ tun_key = nla_data(ovs_key);
+ if (!tun_key->ipv4_dst)
+ return -EINVAL;
+ break;
+