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         bool changed_addr;
  38         int err;
  39
  40         /* register of bridge completed, add sysfs entries */
  41         if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
  42                 br_sysfs_addbr(dev);
  43                 return NOTIFY_DONE;
  44         }
  45
  46         /* not a port of a bridge */
  47         p = br_port_get_rtnl(dev);
  48         if (!p)
  49                 return NOTIFY_DONE;
  50
  51         br = p->br;
  52
  53         switch (event) {
  54         case NETDEV_CHANGEMTU:
  55                 dev_set_mtu(br->dev, br_min_mtu(br));
  56                 break;
  57
  58         case NETDEV_CHANGEADDR:
  59                 spin_lock_bh(&br->lock);
  60                 br_fdb_changeaddr(p, dev->dev_addr);
  61                 changed_addr = br_stp_recalculate_bridge_id(br);
  62                 spin_unlock_bh(&br->lock);
  63
  64                 if (changed_addr)
  65                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  66
  67                 break;
  68
  69         case NETDEV_CHANGE:
  70                 br_port_carrier_check(p);
  71                 break;
  72
  73         case NETDEV_FEAT_CHANGE:
  74                 netdev_update_features(br->dev);
  75                 break;
  76
  77         case NETDEV_DOWN:
  78                 spin_lock_bh(&br->lock);
  79                 if (br->dev->flags & IFF_UP)
  80                         br_stp_disable_port(p);
  81                 spin_unlock_bh(&br->lock);
  82                 break;
  83
  84         case NETDEV_UP:
  85                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
  86                         spin_lock_bh(&br->lock);
  87                         br_stp_enable_port(p);
  88                         spin_unlock_bh(&br->lock);
  89                 }
  90                 break;
  91
  92         case NETDEV_UNREGISTER:
  93                 br_del_if(br, dev);
  94                 break;
  95
  96         case NETDEV_CHANGENAME:
  97                 err = br_sysfs_renameif(p);
  98                 if (err)
  99                         return notifier_from_errno(err);
 100                 break;
 101
 102         case NETDEV_PRE_TYPE_CHANGE:
 103                 /* Forbid underlaying device to change its type. */
 104                 return NOTIFY_BAD;
 105         }
 106
 107         /* Events that may cause spanning tree to refresh */
 108         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 109             event == NETDEV_CHANGE || event == NETDEV_DOWN)
 110                 br_ifinfo_notify(RTM_NEWLINK, p);
 111
 112         return NOTIFY_DONE;
 113 }