diff -urN linux-2.6.21.1.old/include/linux/netdevice.h linux-2.6.21.1.dev/include/linux/netdevice.h
--- linux-2.6.21.1.old/include/linux/netdevice.h	2007-04-27 23:49:26.000000000 +0200
+++ linux-2.6.21.1.dev/include/linux/netdevice.h	2007-05-26 21:04:21.537668920 +0200
@@ -532,6 +532,8 @@
 	struct device		dev;
 	/* space for optional statistics and wireless sysfs groups */
 	struct attribute_group  *sysfs_groups[3];
+	
+	void *ieee80211_ptr;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)