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  *      $Id: br_notify.c,v 1.2 2000/02/21 15:51:34 davem Exp $
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/kernel.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         /* not a port of a bridge */
  39         if (p == NULL)
  40                 return NOTIFY_DONE;
  41
  42         br = p->br;
  43
  44         spin_lock_bh(&br->lock);
  45         switch (event) {
  46         case NETDEV_CHANGEMTU:
  47                 dev_set_mtu(br->dev, br_min_mtu(br));
  48                 break;
  49
  50         case NETDEV_CHANGEADDR:
  51                 br_fdb_changeaddr(p, dev->dev_addr);
  52                 br_stp_recalculate_bridge_id(br);
  53                 break;
  54
  55         case NETDEV_CHANGE:     /* device is up but carrier changed */
  56                 if (!(br->dev->flags & IFF_UP))
  57                         break;
  58
  59                 if (netif_carrier_ok(dev)) {
  60                         if (p->state == BR_STATE_DISABLED)
  61                                 br_stp_enable_port(p);
  62                 } else {
  63                         if (p->state != BR_STATE_DISABLED)
  64                                 br_stp_disable_port(p);
  65                 }
  66                 break;
  67
  68         case NETDEV_DOWN:
  69                 if (br->dev->flags & IFF_UP)
  70                         br_stp_disable_port(p);
  71                 break;
  72
  73         case NETDEV_UP:
  74                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP))
  75                         br_stp_enable_port(p);
  76                 break;
  77
  78         case NETDEV_UNREGISTER:
  79                 spin_unlock_bh(&br->lock);
  80                 br_del_if(br, dev);
  81                 goto done;
  82         }
  83         spin_unlock_bh(&br->lock);
  84
  85  done:
  86         return NOTIFY_DONE;
  87 }