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                 spin_lock_bh(&br->lock);
  70                 if (netif_running(br->dev))
  71                         br_features_recompute(br);
  72                 spin_unlock_bh(&br->lock);
  73                 break;
  74
  75         case NETDEV_DOWN:
  76                 spin_lock_bh(&br->lock);
  77                 if (br->dev->flags & IFF_UP)
  78                         br_stp_disable_port(p);
  79                 spin_unlock_bh(&br->lock);
  80                 break;
  81
  82         case NETDEV_UP:
  83                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
  84                         spin_lock_bh(&br->lock);
  85                         br_stp_enable_port(p);
  86                         spin_unlock_bh(&br->lock);
  87                 }
  88                 break;
  89
  90         case NETDEV_UNREGISTER:
  91                 br_del_if(br, dev);
  92                 break;
  93
  94         case NETDEV_CHANGENAME:
  95                 err = br_sysfs_renameif(p);
  96                 if (err)
  97                         return notifier_from_errno(err);
  98                 break;
  99
 100         case NETDEV_PRE_TYPE_CHANGE:
 101                 /* Forbid underlaying device to change its type. */
 102                 return NOTIFY_BAD;
 103         }
 104
 105         /* Events that may cause spanning tree to refresh */
 106         if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 107             event == NETDEV_CHANGE || event == NETDEV_DOWN)
 108                 br_ifinfo_notify(RTM_NEWLINK, p);
 109
 110         return NOTIFY_DONE;
 111 }