+#include <linux/version.h>
+/* Before 2.6.21, struct net_device has a "struct class_device" member named
+ * class_dev. Beginning with 2.6.21, struct net_device instead has a "struct
+ * device" member named dev. Otherwise the usage of these members is pretty
+ * much the same. */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)
+#define NETDEV_DEV_MEMBER class_dev
+#else
+#define NETDEV_DEV_MEMBER dev
+#endif
+