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
 20static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr);
 21
 22struct 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 */
 32static 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}