[AX25]: Sanitize ax25 netdevice private handling.

include/linux/netdevice.h

@@ -333,6 +333,7 @@ struct net_device
 	void                    *dn_ptr;        /* DECnet specific data */
 	void                    *ip6_ptr;       /* IPv6 specific data */
 	void			*ec_ptr;	/* Econet specific data	*/
+	void			*ax25_ptr;	/* AX.25 specific data */
 
 	struct list_head	poll_list;	/* Link to poll list	*/
 	int			quota;

include/net/ax25.h

@@ -233,7 +233,12 @@ extern void ax25_digi_invert(ax25_digi *, ax25_digi *);
 /* ax25_dev.c */
 extern ax25_dev *ax25_dev_list;
 extern spinlock_t ax25_dev_lock;
-extern ax25_dev *ax25_dev_ax25dev(struct net_device *);
+
+static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
+{
+	return dev->ax25_ptr;
+}
+
 extern ax25_dev *ax25_addr_ax25dev(ax25_address *);
 extern void ax25_dev_device_up(struct net_device *);
 extern void ax25_dev_device_down(struct net_device *);

net/ax25/ax25_dev.c

@@ -34,21 +34,6 @@
 ax25_dev *ax25_dev_list;
 spinlock_t ax25_dev_lock = SPIN_LOCK_UNLOCKED;
 
-ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
-{
-	ax25_dev *ax25_dev, *res = NULL;
-
-	spin_lock_bh(&ax25_dev_lock);
-	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
-		if (ax25_dev->dev == dev) {
-			res = ax25_dev;
-			break;
-		}
-	spin_unlock_bh(&ax25_dev_lock);
-
-	return res;
-}
-
 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
 {
 	ax25_dev *ax25_dev, *res = NULL;
@@ -80,6 +65,7 @@ void ax25_dev_device_up(struct net_device *dev)
 
 	memset(ax25_dev, 0x00, sizeof(*ax25_dev));
 
+	dev->ax25_ptr     = ax25_dev;
 	ax25_dev->dev     = dev;
 	ax25_dev->forward = NULL;
 
@@ -152,6 +138,7 @@ void ax25_dev_device_down(struct net_device *dev)
 		s = s->next;
 	}
 	spin_unlock_bh(&ax25_dev_lock);
+	dev->ax25_ptr = NULL;
 
 	ax25_register_sysctl();
 }