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 = dev->br_port;
  36         struct net_bridge *br;
  37
  38         if (!net_eq(dev_net(dev), &init_net))
  39                 return NOTIFY_DONE;
  40
  41         /* not a port of a bridge */
  42         if (p == NULL)
  43                 return NOTIFY_DONE;
  44
  45         br = p->br;
  46
  47         switch (event) {
  48         case NETDEV_CHANGEMTU:
  49                 dev_set_mtu(br->dev, br_min_mtu(br));
  50                 break;
  51
  52         case NETDEV_CHANGEADDR:
  53                 spin_lock_bh(&br->lock);
  54                 br_fdb_changeaddr(p, dev->dev_addr);
  55                 br_stp_recalculate_bridge_id(br);
  56                 spin_unlock_bh(&br->lock);
  57                 break;
  58
  59         case NETDEV_CHANGE:
  60                 br_port_carrier_check(p);
  61                 break;
  62
  63         case NETDEV_FEAT_CHANGE:
  64                 spin_lock_bh(&br->lock);
  65                 if (netif_running(br->dev))
  66                         br_features_recompute(br);
  67                 spin_unlock_bh(&br->lock);
  68                 break;
  69
  70         case NETDEV_DOWN:
  71                 spin_lock_bh(&br->lock);
  72                 if (br->dev->flags & IFF_UP)
  73                         br_stp_disable_port(p);
  74                 spin_unlock_bh(&br->lock);
  75                 break;
  76
  77         case NETDEV_UP:
  78                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
  79                         spin_lock_bh(&br->lock);
  80                         br_stp_enable_port(p);
  81                         spin_unlock_bh(&br->lock);
  82                 }
  83                 break;
  84
  85         case NETDEV_UNREGISTER:
  86                 br_del_if(br, dev);
  87                 break;
  88         }
  89
  90         /* Events that may cause spanning tree to refresh */
  91         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
  92             event == NETDEV_CHANGE || event == NETDEV_DOWN)
  93                 br_ifinfo_notify(RTM_NEWLINK, p);
  94
  95         return NOTIFY_DONE;
  96 }