net/bridge/br_if.c - kernel/msm-4.9 - Gitiles

 /*
  *	Userspace interface
  *	Linux ethernet bridge
  *
  *	Authors:
  *	Lennert Buytenhek		<buytenh@gnu.org>
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License
  *	as published by the Free Software Foundation; either version
  *	2 of the License, or (at your option) any later version.
  */

 #include <linux/kernel.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/netpoll.h>
 #include <linux/ethtool.h>
 #include <linux/if_arp.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/rtnetlink.h>
 #include <linux/if_ether.h>
 #include <linux/slab.h>
 #include <net/sock.h>
 #include <linux/if_vlan.h>

 #include "br_private.h"

 /*
  * Determine initial path cost based on speed.
  * using recommendations from 802.1d standard
  *
  * Since driver might sleep need to not be holding any locks.
  */
 static int port_cost(struct net_device *dev)
 {
 	struct ethtool_cmd ecmd;

 	if (!__ethtool_get_settings(dev, &ecmd)) {
 		switch (ethtool_cmd_speed(&ecmd)) {
 		case SPEED_10000:
 			return 2;
 		case SPEED_1000:
 			return 4;
 		case SPEED_100:
 			return 19;
 		case SPEED_10:
 			return 100;
 		}
 	}

 	/* Old silly heuristics based on name */
 	if (!strncmp(dev->name, "lec", 3))
 		return 7;

 	if (!strncmp(dev->name, "plip", 4))
 		return 2500;

 	return 100;	/* assume old 10Mbps */
 }


 /* Check for port carrier transitions. */
 void br_port_carrier_check(struct net_bridge_port *p)
 {
 	struct net_device *dev = p->dev;
 	struct net_bridge *br = p->br;

 	if (!(p->flags & BR_ADMIN_COST) &&
 	    netif_running(dev) && netif_oper_up(dev))
 		p->path_cost = port_cost(dev);

 	if (!netif_running(br->dev))
 		return;

 	spin_lock_bh(&br->lock);
 	if (netif_running(dev) && netif_oper_up(dev)) {
 		if (p->state == BR_STATE_DISABLED)
 			br_stp_enable_port(p);
 	} else {
 		if (p->state != BR_STATE_DISABLED)
 			br_stp_disable_port(p);
 	}
 	spin_unlock_bh(&br->lock);
 }

 static void release_nbp(struct kobject *kobj)
 {
 	struct net_bridge_port *p
 		= container_of(kobj, struct net_bridge_port, kobj);
 	kfree(p);
 }

 static struct kobj_type brport_ktype = {
 #ifdef CONFIG_SYSFS
 	.sysfs_ops = &brport_sysfs_ops,
 #endif
 	.release = release_nbp,
 };

 static void destroy_nbp(struct net_bridge_port *p)
 {
 	struct net_device *dev = p->dev;

 	p->br = NULL;
 	p->dev = NULL;
 	dev_put(dev);

 	kobject_put(&p->kobj);
 }

 static void destroy_nbp_rcu(struct rcu_head *head)
 {
 	struct net_bridge_port *p =
 			container_of(head, struct net_bridge_port, rcu);
 	destroy_nbp(p);
 }

 /* Delete port(interface) from bridge is done in two steps.
  * via RCU. First step, marks device as down. That deletes
  * all the timers and stops new packets from flowing through.
  *
  * Final cleanup doesn't occur until after all CPU's finished
  * processing packets.
  *
  * Protected from multiple admin operations by RTNL mutex
  */
 static void del_nbp(struct net_bridge_port *p)
 {
 	struct net_bridge *br = p->br;
 	struct net_device *dev = p->dev;

 	sysfs_remove_link(br->ifobj, p->dev->name);

 	dev_set_promiscuity(dev, -1);

 	spin_lock_bh(&br->lock);
 	br_stp_disable_port(p);
 	spin_unlock_bh(&br->lock);

 	br_ifinfo_notify(RTM_DELLINK, p);

 	nbp_vlan_flush(p);
 	br_fdb_delete_by_port(br, p, 1);

 	list_del_rcu(&p->list);

 	dev->priv_flags &= ~IFF_BRIDGE_PORT;

 	netdev_rx_handler_unregister(dev);

 	netdev_upper_dev_unlink(dev, br->dev);

 	br_multicast_del_port(p);

 	kobject_uevent(&p->kobj, KOBJ_REMOVE);
 	kobject_del(&p->kobj);

 	br_netpoll_disable(p);

 	call_rcu(&p->rcu, destroy_nbp_rcu);
 }

 /* Delete bridge device */
 void br_dev_delete(struct net_device *dev, struct list_head *head)
 {
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *p, *n;

 	list_for_each_entry_safe(p, n, &br->port_list, list) {
 		del_nbp(p);
 	}

 	br_fdb_delete_by_port(br, NULL, 1);

 	br_vlan_flush(br);
 	del_timer_sync(&br->gc_timer);

 	br_sysfs_delbr(br->dev);
 	unregister_netdevice_queue(br->dev, head);
 }

 /* find an available port number */
 static int find_portno(struct net_bridge *br)
 {
 	int index;
 	struct net_bridge_port *p;
 	unsigned long *inuse;

 	inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
 			GFP_KERNEL);
 	if (!inuse)
 		return -ENOMEM;

 	set_bit(0, inuse);	/* zero is reserved */
 	list_for_each_entry(p, &br->port_list, list) {
 		set_bit(p->port_no, inuse);
 	}
 	index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 	kfree(inuse);

 	return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 }

 /* called with RTNL but without bridge lock */
 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 				       struct net_device *dev)
 {
 	int index;
 	struct net_bridge_port *p;

 	index = find_portno(br);
 	if (index < 0)
 		return ERR_PTR(index);

 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (p == NULL)
 		return ERR_PTR(-ENOMEM);

 	p->br = br;
 	dev_hold(dev);
 	p->dev = dev;
 	p->path_cost = port_cost(dev);
 	p->priority = 0x8000 >> BR_PORT_BITS;
 	p->port_no = index;
 	p->flags = BR_LEARNING | BR_FLOOD;
 	br_init_port(p);
 	p->state = BR_STATE_DISABLED;
 	br_stp_port_timer_init(p);
 	br_multicast_add_port(p);

 	return p;
 }

 int br_add_bridge(struct net *net, const char *name)
 {
 	struct net_device *dev;
 	int res;

 	dev = alloc_netdev(sizeof(struct net_bridge), name,
 			   br_dev_setup);

 	if (!dev)
 		return -ENOMEM;

 	dev_net_set(dev, net);
 	dev->rtnl_link_ops = &br_link_ops;

 	res = register_netdev(dev);
 	if (res)
 		free_netdev(dev);
 	return res;
 }

 int br_del_bridge(struct net *net, const char *name)
 {
 	struct net_device *dev;
 	int ret = 0;

 	rtnl_lock();
 	dev = __dev_get_by_name(net, name);
 	if (dev == NULL)
 		ret =  -ENXIO; 	/* Could not find device */

 	else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 		/* Attempt to delete non bridge device! */
 		ret = -EPERM;
 	}

 	else if (dev->flags & IFF_UP) {
 		/* Not shutdown yet. */
 		ret = -EBUSY;
 	}

 	else
 		br_dev_delete(dev, NULL);

 	rtnl_unlock();
 	return ret;
 }

 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 int br_min_mtu(const struct net_bridge *br)
 {
 	const struct net_bridge_port *p;
 	int mtu = 0;

 	ASSERT_RTNL();

 	if (list_empty(&br->port_list))
 		mtu = ETH_DATA_LEN;
 	else {
 		list_for_each_entry(p, &br->port_list, list) {
 			if (!mtu  || p->dev->mtu < mtu)
 				mtu = p->dev->mtu;
 		}
 	}
 	return mtu;
 }

 /*
  * Recomputes features using slave's features
  */
 netdev_features_t br_features_recompute(struct net_bridge *br,
 	netdev_features_t features)
 {
 	struct net_bridge_port *p;
 	netdev_features_t mask;

 	if (list_empty(&br->port_list))
 		return features;

 	mask = features;
 	features &= ~NETIF_F_ONE_FOR_ALL;

 	list_for_each_entry(p, &br->port_list, list) {
 		features = netdev_increment_features(features,
 						     p->dev->features, mask);
 	}

 	return features;
 }

 /* called with RTNL */
 int br_add_if(struct net_bridge *br, struct net_device *dev)
 {
 	struct net_bridge_port *p;
 	int err = 0;
 	bool changed_addr;

 	/* Don't allow bridging non-ethernet like devices */
 	if ((dev->flags & IFF_LOOPBACK) ||
 	    dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 	    !is_valid_ether_addr(dev->dev_addr))
 		return -EINVAL;

 	/* No bridging of bridges */
 	if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
 		return -ELOOP;

 	/* Device is already being bridged */
 	if (br_port_exists(dev))
 		return -EBUSY;

 	/* No bridging devices that dislike that (e.g. wireless) */
 	if (dev->priv_flags & IFF_DONT_BRIDGE)
 		return -EOPNOTSUPP;

 	p = new_nbp(br, dev);
 	if (IS_ERR(p))
 		return PTR_ERR(p);

 	call_netdevice_notifiers(NETDEV_JOIN, dev);

 	err = dev_set_promiscuity(dev, 1);
 	if (err)
 		goto put_back;

 	err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 				   SYSFS_BRIDGE_PORT_ATTR);
 	if (err)
 		goto err1;

 	err = br_sysfs_addif(p);
 	if (err)
 		goto err2;

 	err = br_netpoll_enable(p);
 	if (err)
 		goto err3;

 	err = netdev_master_upper_dev_link(dev, br->dev);
 	if (err)
 		goto err4;

 	err = netdev_rx_handler_register(dev, br_handle_frame, p);
 	if (err)
 		goto err5;

 	dev->priv_flags |= IFF_BRIDGE_PORT;

 	dev_disable_lro(dev);

 	list_add_rcu(&p->list, &br->port_list);

 	netdev_update_features(br->dev);

 	if (br->dev->needed_headroom < dev->needed_headroom)
 		br->dev->needed_headroom = dev->needed_headroom;

 	if (br_fdb_insert(br, p, dev->dev_addr, 0))
 		netdev_err(dev, "failed insert local address bridge forwarding table\n");

 	spin_lock_bh(&br->lock);
 	changed_addr = br_stp_recalculate_bridge_id(br);

 	if (netif_running(dev) && netif_oper_up(dev) &&
 	    (br->dev->flags & IFF_UP))
 		br_stp_enable_port(p);
 	spin_unlock_bh(&br->lock);

 	br_ifinfo_notify(RTM_NEWLINK, p);

 	if (changed_addr)
 		call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

 	dev_set_mtu(br->dev, br_min_mtu(br));

 	kobject_uevent(&p->kobj, KOBJ_ADD);

 	return 0;

 err5:
 	netdev_upper_dev_unlink(dev, br->dev);
 err4:
 	br_netpoll_disable(p);
 err3:
 	sysfs_remove_link(br->ifobj, p->dev->name);
 err2:
 	kobject_put(&p->kobj);
 	p = NULL; /* kobject_put frees */
 err1:
 	dev_set_promiscuity(dev, -1);
 put_back:
 	dev_put(dev);
 	kfree(p);
 	return err;
 }

 /* called with RTNL */
 int br_del_if(struct net_bridge *br, struct net_device *dev)
 {
 	struct net_bridge_port *p;
 	bool changed_addr;

 	p = br_port_get_rtnl(dev);
 	if (!p || p->br != br)
 		return -EINVAL;

 	/* Since more than one interface can be attached to a bridge,
 	 * there still maybe an alternate path for netconsole to use;
 	 * therefore there is no reason for a NETDEV_RELEASE event.
 	 */
 	del_nbp(p);

 	spin_lock_bh(&br->lock);
 	changed_addr = br_stp_recalculate_bridge_id(br);
 	spin_unlock_bh(&br->lock);

 	if (changed_addr)
 		call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

 	netdev_update_features(br->dev);

 	return 0;
 }
	/*
	* Userspace interface
	* Linux ethernet bridge
	*
	* Authors:
	* Lennert Buytenhek <buytenh@gnu.org>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	#include <linux/kernel.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/netpoll.h>
	#include <linux/ethtool.h>
	#include <linux/if_arp.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/rtnetlink.h>
	#include <linux/if_ether.h>
	#include <linux/slab.h>
	#include <net/sock.h>
	#include <linux/if_vlan.h>

	#include "br_private.h"

	/*
	* Determine initial path cost based on speed.
	* using recommendations from 802.1d standard
	*
	* Since driver might sleep need to not be holding any locks.
	*/
	static int port_cost(struct net_device *dev)
	{
	struct ethtool_cmd ecmd;

	if (!__ethtool_get_settings(dev, &ecmd)) {
	switch (ethtool_cmd_speed(&ecmd)) {
	case SPEED_10000:
	return 2;
	case SPEED_1000:
	return 4;
	case SPEED_100:
	return 19;
	case SPEED_10:
	return 100;
	}
	}

	/* Old silly heuristics based on name */
	if (!strncmp(dev->name, "lec", 3))
	return 7;

	if (!strncmp(dev->name, "plip", 4))
	return 2500;

	return 100; /* assume old 10Mbps */
	}


	/* Check for port carrier transitions. */
	void br_port_carrier_check(struct net_bridge_port *p)
	{
	struct net_device *dev = p->dev;
	struct net_bridge *br = p->br;

	if (!(p->flags & BR_ADMIN_COST) &&
	netif_running(dev) && netif_oper_up(dev))
	p->path_cost = port_cost(dev);

	if (!netif_running(br->dev))
	return;

	spin_lock_bh(&br->lock);
	if (netif_running(dev) && netif_oper_up(dev)) {
	if (p->state == BR_STATE_DISABLED)
	br_stp_enable_port(p);
	} else {
	if (p->state != BR_STATE_DISABLED)
	br_stp_disable_port(p);
	}
	spin_unlock_bh(&br->lock);
	}

	static void release_nbp(struct kobject *kobj)
	{
	struct net_bridge_port *p
	= container_of(kobj, struct net_bridge_port, kobj);
	kfree(p);
	}

	static struct kobj_type brport_ktype = {
	#ifdef CONFIG_SYSFS
	.sysfs_ops = &brport_sysfs_ops,
	#endif
	.release = release_nbp,
	};

	static void destroy_nbp(struct net_bridge_port *p)
	{
	struct net_device *dev = p->dev;

	p->br = NULL;
	p->dev = NULL;
	dev_put(dev);

	kobject_put(&p->kobj);
	}

	static void destroy_nbp_rcu(struct rcu_head *head)
	{
	struct net_bridge_port *p =
	container_of(head, struct net_bridge_port, rcu);
	destroy_nbp(p);
	}

	/* Delete port(interface) from bridge is done in two steps.
	* via RCU. First step, marks device as down. That deletes
	* all the timers and stops new packets from flowing through.
	*
	* Final cleanup doesn't occur until after all CPU's finished
	* processing packets.
	*
	* Protected from multiple admin operations by RTNL mutex
	*/
	static void del_nbp(struct net_bridge_port *p)
	{
	struct net_bridge *br = p->br;
	struct net_device *dev = p->dev;

	sysfs_remove_link(br->ifobj, p->dev->name);

	dev_set_promiscuity(dev, -1);

	spin_lock_bh(&br->lock);
	br_stp_disable_port(p);
	spin_unlock_bh(&br->lock);

	br_ifinfo_notify(RTM_DELLINK, p);

	nbp_vlan_flush(p);
	br_fdb_delete_by_port(br, p, 1);

	list_del_rcu(&p->list);

	dev->priv_flags &= ~IFF_BRIDGE_PORT;

	netdev_rx_handler_unregister(dev);

	netdev_upper_dev_unlink(dev, br->dev);

	br_multicast_del_port(p);

	kobject_uevent(&p->kobj, KOBJ_REMOVE);
	kobject_del(&p->kobj);

	br_netpoll_disable(p);

	call_rcu(&p->rcu, destroy_nbp_rcu);
	}

	/* Delete bridge device */
	void br_dev_delete(struct net_device dev, struct list_head head)
	{
	struct net_bridge *br = netdev_priv(dev);
	struct net_bridge_port p, n;

	list_for_each_entry_safe(p, n, &br->port_list, list) {
	del_nbp(p);
	}

	br_fdb_delete_by_port(br, NULL, 1);

	br_vlan_flush(br);
	del_timer_sync(&br->gc_timer);

	br_sysfs_delbr(br->dev);
	unregister_netdevice_queue(br->dev, head);
	}

	/* find an available port number */
	static int find_portno(struct net_bridge *br)
	{
	int index;
	struct net_bridge_port *p;
	unsigned long *inuse;

	inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
	GFP_KERNEL);
	if (!inuse)
	return -ENOMEM;

	set_bit(0, inuse); /* zero is reserved */
	list_for_each_entry(p, &br->port_list, list) {
	set_bit(p->port_no, inuse);
	}
	index = find_first_zero_bit(inuse, BR_MAX_PORTS);
	kfree(inuse);

	return (index >= BR_MAX_PORTS) ? -EXFULL : index;
	}

	/* called with RTNL but without bridge lock */
	static struct net_bridge_port new_nbp(struct net_bridge br,
	struct net_device *dev)
	{
	int index;
	struct net_bridge_port *p;

	index = find_portno(br);
	if (index < 0)
	return ERR_PTR(index);

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (p == NULL)
	return ERR_PTR(-ENOMEM);

	p->br = br;
	dev_hold(dev);
	p->dev = dev;
	p->path_cost = port_cost(dev);
	p->priority = 0x8000 >> BR_PORT_BITS;
	p->port_no = index;
	p->flags = BR_LEARNING \| BR_FLOOD;
	br_init_port(p);
	p->state = BR_STATE_DISABLED;
	br_stp_port_timer_init(p);
	br_multicast_add_port(p);

	return p;
	}

	int br_add_bridge(struct net net, const char name)
	{
	struct net_device *dev;
	int res;

	dev = alloc_netdev(sizeof(struct net_bridge), name,
	br_dev_setup);

	if (!dev)
	return -ENOMEM;

	dev_net_set(dev, net);
	dev->rtnl_link_ops = &br_link_ops;

	res = register_netdev(dev);
	if (res)
	free_netdev(dev);
	return res;
	}

	int br_del_bridge(struct net net, const char name)
	{
	struct net_device *dev;
	int ret = 0;

	rtnl_lock();
	dev = __dev_get_by_name(net, name);
	if (dev == NULL)
	ret = -ENXIO; /* Could not find device */

	else if (!(dev->priv_flags & IFF_EBRIDGE)) {
	/* Attempt to delete non bridge device! */
	ret = -EPERM;
	}

	else if (dev->flags & IFF_UP) {
	/* Not shutdown yet. */
	ret = -EBUSY;
	}

	else
	br_dev_delete(dev, NULL);

	rtnl_unlock();
	return ret;
	}

	/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
	int br_min_mtu(const struct net_bridge *br)
	{
	const struct net_bridge_port *p;
	int mtu = 0;

	ASSERT_RTNL();

	if (list_empty(&br->port_list))
	mtu = ETH_DATA_LEN;
	else {
	list_for_each_entry(p, &br->port_list, list) {
	if (!mtu \|\| p->dev->mtu < mtu)
	mtu = p->dev->mtu;
	}
	}
	return mtu;
	}

	/*
	* Recomputes features using slave's features
	*/
	netdev_features_t br_features_recompute(struct net_bridge *br,
	netdev_features_t features)
	{
	struct net_bridge_port *p;
	netdev_features_t mask;

	if (list_empty(&br->port_list))
	return features;

	mask = features;
	features &= ~NETIF_F_ONE_FOR_ALL;

	list_for_each_entry(p, &br->port_list, list) {
	features = netdev_increment_features(features,
	p->dev->features, mask);
	}

	return features;
	}

	/* called with RTNL */
	int br_add_if(struct net_bridge br, struct net_device dev)
	{
	struct net_bridge_port *p;
	int err = 0;
	bool changed_addr;

	/* Don't allow bridging non-ethernet like devices */
	if ((dev->flags & IFF_LOOPBACK) \|\|
	dev->type != ARPHRD_ETHER \|\| dev->addr_len != ETH_ALEN \|\|
	!is_valid_ether_addr(dev->dev_addr))
	return -EINVAL;

	/* No bridging of bridges */
	if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
	return -ELOOP;

	/* Device is already being bridged */
	if (br_port_exists(dev))
	return -EBUSY;

	/* No bridging devices that dislike that (e.g. wireless) */
	if (dev->priv_flags & IFF_DONT_BRIDGE)
	return -EOPNOTSUPP;

	p = new_nbp(br, dev);
	if (IS_ERR(p))
	return PTR_ERR(p);

	call_netdevice_notifiers(NETDEV_JOIN, dev);

	err = dev_set_promiscuity(dev, 1);
	if (err)
	goto put_back;

	err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
	SYSFS_BRIDGE_PORT_ATTR);
	if (err)
	goto err1;

	err = br_sysfs_addif(p);
	if (err)
	goto err2;

	err = br_netpoll_enable(p);
	if (err)
	goto err3;

	err = netdev_master_upper_dev_link(dev, br->dev);
	if (err)
	goto err4;

	err = netdev_rx_handler_register(dev, br_handle_frame, p);
	if (err)
	goto err5;

	dev->priv_flags \|= IFF_BRIDGE_PORT;

	dev_disable_lro(dev);

	list_add_rcu(&p->list, &br->port_list);

	netdev_update_features(br->dev);

	if (br->dev->needed_headroom < dev->needed_headroom)
	br->dev->needed_headroom = dev->needed_headroom;

	if (br_fdb_insert(br, p, dev->dev_addr, 0))
	netdev_err(dev, "failed insert local address bridge forwarding table\n");

	spin_lock_bh(&br->lock);
	changed_addr = br_stp_recalculate_bridge_id(br);

	if (netif_running(dev) && netif_oper_up(dev) &&
	(br->dev->flags & IFF_UP))
	br_stp_enable_port(p);
	spin_unlock_bh(&br->lock);

	br_ifinfo_notify(RTM_NEWLINK, p);

	if (changed_addr)
	call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

	dev_set_mtu(br->dev, br_min_mtu(br));

	kobject_uevent(&p->kobj, KOBJ_ADD);

	return 0;

	err5:
	netdev_upper_dev_unlink(dev, br->dev);
	err4:
	br_netpoll_disable(p);
	err3:
	sysfs_remove_link(br->ifobj, p->dev->name);
	err2:
	kobject_put(&p->kobj);
	p = NULL; /* kobject_put frees */
	err1:
	dev_set_promiscuity(dev, -1);
	put_back:
	dev_put(dev);
	kfree(p);
	return err;
	}

	/* called with RTNL */
	int br_del_if(struct net_bridge br, struct net_device dev)
	{
	struct net_bridge_port *p;
	bool changed_addr;

	p = br_port_get_rtnl(dev);
	if (!p \|\| p->br != br)
	return -EINVAL;

	/* Since more than one interface can be attached to a bridge,
	* there still maybe an alternate path for netconsole to use;
	* therefore there is no reason for a NETDEV_RELEASE event.
	*/
	del_nbp(p);

	spin_lock_bh(&br->lock);
	changed_addr = br_stp_recalculate_bridge_id(br);
	spin_unlock_bh(&br->lock);

	if (changed_addr)
	call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);

	netdev_update_features(br->dev);

	return 0;
	}