rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER
[linux-2.6.git] / net / bridge / br_notify.c
1 /*
2  *      Device event handling
3  *      Linux ethernet bridge
4  *
5  *      Authors:
6  *      Lennert Buytenhek               <buytenh@gnu.org>
7  *
8  *      This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/rtnetlink.h>
16 #include <net/net_namespace.h>
17
18 #include "br_private.h"
19
20 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr);
21
22 struct notifier_block br_device_notifier = {
23         .notifier_call = br_device_event
24 };
25
26 /*
27  * Handle changes in state of network devices enslaved to a bridge.
28  *
29  * Note: don't care about up/down if bridge itself is down, because
30  *     port state is checked when bridge is brought up.
31  */
32 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
33 {
34         struct net_device *dev = ptr;
35         struct net_bridge_port *p;
36         struct net_bridge *br;
37         int err;
38
39         /* register of bridge completed, add sysfs entries */
40         if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
41                 br_sysfs_addbr(dev);
42                 return NOTIFY_DONE;
43         }
44
45         /* not a port of a bridge */
46         p = br_port_get_rtnl(dev);
47         if (!p)
48                 return NOTIFY_DONE;
49
50         br = p->br;
51
52         switch (event) {
53         case NETDEV_CHANGEMTU:
54                 dev_set_mtu(br->dev, br_min_mtu(br));
55                 break;
56
57         case NETDEV_CHANGEADDR:
58                 spin_lock_bh(&br->lock);
59                 br_fdb_changeaddr(p, dev->dev_addr);
60                 br_stp_recalculate_bridge_id(br);
61                 spin_unlock_bh(&br->lock);
62                 break;
63
64         case NETDEV_CHANGE:
65                 br_port_carrier_check(p);
66                 break;
67
68         case NETDEV_FEAT_CHANGE:
69                 netdev_update_features(br->dev);
70                 break;
71
72         case NETDEV_DOWN:
73                 spin_lock_bh(&br->lock);
74                 if (br->dev->flags & IFF_UP)
75                         br_stp_disable_port(p);
76                 spin_unlock_bh(&br->lock);
77                 break;
78
79         case NETDEV_UP:
80                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
81                         spin_lock_bh(&br->lock);
82                         br_stp_enable_port(p);
83                         spin_unlock_bh(&br->lock);
84                 }
85                 break;
86
87         case NETDEV_UNREGISTER:
88                 br_del_if(br, dev);
89                 break;
90
91         case NETDEV_CHANGENAME:
92                 err = br_sysfs_renameif(p);
93                 if (err)
94                         return notifier_from_errno(err);
95                 break;
96
97         case NETDEV_PRE_TYPE_CHANGE:
98                 /* Forbid underlaying device to change its type. */
99                 return NOTIFY_BAD;
100         }
101
102         /* Events that may cause spanning tree to refresh */
103         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
104             event == NETDEV_CHANGE || event == NETDEV_DOWN)
105                 br_ifinfo_notify(RTM_NEWLINK, p);
106
107         return NOTIFY_DONE;
108 }