6lowpan: handle NETDEV_UNREGISTER event

Before, it was impossible to remove a wpan device which had lowpan
attached to it.

Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@tempietto.lan>

1 files changed, 37 insertions, 7 deletions

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index b28ec790c7c8..d5291113584f 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1063,12 +1063,6 @@ out:
         return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
 }
 
-static void lowpan_dev_free(struct net_device *dev)
-{
-        dev_put(lowpan_dev_info(dev)->real_dev);
-        free_netdev(dev);
-}
-
 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
 {
         struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
@@ -1118,7 +1112,7 @@ static void lowpan_setup(struct net_device *dev)
         dev->netdev_ops         = &lowpan_netdev_ops;
         dev->header_ops         = &lowpan_header_ops;
         dev->ml_priv            = &lowpan_mlme;
-        dev->destructor         = lowpan_dev_free;
+        dev->destructor         = free_netdev;
 }
 
 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1244,6 +1238,34 @@ static inline void __init lowpan_netlink_fini(void)
         rtnl_link_unregister(&lowpan_link_ops);
 }
 
+static int lowpan_device_event(struct notifier_block *unused,
+                                unsigned long event,
+                                void *ptr)
+{
+        struct net_device *dev = ptr;
+        LIST_HEAD(del_list);
+        struct lowpan_dev_record *entry, *tmp;
+
+        if (dev->type != ARPHRD_IEEE802154)
+                goto out;
+
+        if (event == NETDEV_UNREGISTER) {
+                list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+                        if (lowpan_dev_info(entry->ldev)->real_dev == dev)
+                                lowpan_dellink(entry->ldev, &del_list);
+                }
+
+                unregister_netdevice_many(&del_list);
+        };
+
+out:
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block lowpan_dev_notifier = {
+        .notifier_call = lowpan_device_event,
+};
+
 static struct packet_type lowpan_packet_type = {
         .type = __constant_htons(ETH_P_IEEE802154),
         .func = lowpan_rcv,
@@ -1258,6 +1280,12 @@ static int __init lowpan_init_module(void)
                 goto out;
 
         dev_add_pack(&lowpan_packet_type);
+
+        err = register_netdevice_notifier(&lowpan_dev_notifier);
+        if (err < 0) {
+                dev_remove_pack(&lowpan_packet_type);
+                lowpan_netlink_fini();
+        }
 out:
         return err;
 }
@@ -1270,6 +1298,8 @@ static void __exit lowpan_cleanup_module(void)
 
         dev_remove_pack(&lowpan_packet_type);
 
+        unregister_netdevice_notifier(&lowpan_dev_notifier);
+
         /* Now 6lowpan packet_type is removed, so no new fragments are
          * expected on RX, therefore that's the time to clean incomplete
          * fragments.