[linux-block.git] / net / bridge / br_if.c

/*
 *	Userspace interface
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 *
 *	$Id: br_if.c,v 1.7 2001/12/24 00:59:55 davem Exp $
 *
 *	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/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 <net/sock.h>

#include "br_private.h"

/*
 * Determine initial path cost based on speed.
 * using recommendations from 802.1d standard
 *
 * Need to simulate user ioctl because not all device's that support
 * ethtool, use ethtool_ops.  Also, since driver might sleep need to
 * not be holding any locks.
 */
static int port_cost(struct net_device *dev)
{
	struct ethtool_cmd ecmd = { ETHTOOL_GSET };
	struct ifreq ifr;
	mm_segment_t old_fs;
	int err;

	strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
	ifr.ifr_data = (void __user *) &ecmd;

	old_fs = get_fs();
	set_fs(KERNEL_DS);
	err = dev_ethtool(&ifr);
	set_fs(old_fs);

	if (!err) {
		switch(ecmd.speed) {
		case SPEED_100:
			return 19;
		case SPEED_1000:
			return 4;
		case SPEED_10000:
			return 2;
		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 transistions.
 * Called from work queue to allow for calling functions that
 * might sleep (such as speed check), and to debounce.
 */
void br_port_carrier_check(struct net_bridge_port *p)
{
	struct net_device *dev = p->dev;
	struct net_bridge *br = p->br;

	if (netif_carrier_ok(dev))
		p->path_cost = port_cost(dev);

	if (netif_running(br->dev)) {
		spin_lock_bh(&br->lock);
		if (netif_carrier_ok(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, dev->name);

	dev_set_promiscuity(dev, -1);

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

	br_fdb_delete_by_port(br, p, 1);

	list_del_rcu(&p->list);

	rcu_assign_pointer(dev->br_port, NULL);

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

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

/* called with RTNL */
static void del_br(struct net_bridge *br)
{
	struct net_bridge_port *p, *n;

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

	del_timer_sync(&br->gc_timer);

	br_sysfs_delbr(br->dev);
	unregister_netdevice(br->dev);
}

static struct net_device *new_bridge_dev(const char *name)
{
	struct net_bridge *br;
	struct net_device *dev;

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

	if (!dev)
		return NULL;

	br = netdev_priv(dev);
	br->dev = dev;

	spin_lock_init(&br->lock);
	INIT_LIST_HEAD(&br->port_list);
	spin_lock_init(&br->hash_lock);

	br->bridge_id.prio[0] = 0x80;
	br->bridge_id.prio[1] = 0x00;

	memcpy(br->group_addr, br_group_address, ETH_ALEN);

	br->feature_mask = dev->features;
	br->stp_enabled = 0;
	br->designated_root = br->bridge_id;
	br->root_path_cost = 0;
	br->root_port = 0;
	br->bridge_max_age = br->max_age = 20 * HZ;
	br->bridge_hello_time = br->hello_time = 2 * HZ;
	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
	br->topology_change = 0;
	br->topology_change_detected = 0;
	br->ageing_time = 300 * HZ;
	INIT_LIST_HEAD(&br->age_list);

	br_stp_timer_init(br);

	return dev;
}

/* 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;
	br_init_port(p);
	p->state = BR_STATE_DISABLED;
	br_stp_port_timer_init(p);

	kobject_init(&p->kobj);
	kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
	p->kobj.ktype = &brport_ktype;
	p->kobj.parent = &(dev->dev.kobj);
	p->kobj.kset = NULL;

	return p;
}

int br_add_bridge(const char *name)
{
	struct net_device *dev;
	int ret;

	dev = new_bridge_dev(name);
	if (!dev)
		return -ENOMEM;

	rtnl_lock();
	if (strchr(dev->name, '%')) {
		ret = dev_alloc_name(dev, dev->name);
		if (ret < 0) {
			free_netdev(dev);
			goto out;
		}
	}

	ret = register_netdevice(dev);
	if (ret)
		goto out;

	ret = br_sysfs_addbr(dev);
	if (ret)
		unregister_netdevice(dev);
 out:
	rtnl_unlock();
	return ret;
}

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

	rtnl_lock();
	dev = __dev_get_by_name(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
		del_br(netdev_priv(dev));

	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
 */
void br_features_recompute(struct net_bridge *br)
{
	struct net_bridge_port *p;
	unsigned long features, checksum;

	checksum = br->feature_mask & NETIF_F_ALL_CSUM ? NETIF_F_NO_CSUM : 0;
	features = br->feature_mask & ~NETIF_F_ALL_CSUM;

	list_for_each_entry(p, &br->port_list, list) {
		unsigned long feature = p->dev->features;

		if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
			checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
		if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
			checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
		if (!(feature & NETIF_F_IP_CSUM))
			checksum = 0;

		if (feature & NETIF_F_GSO)
			feature |= NETIF_F_GSO_SOFTWARE;
		feature |= NETIF_F_GSO;

		features &= feature;
	}

	if (!(checksum & NETIF_F_ALL_CSUM))
		features &= ~NETIF_F_SG;
	if (!(features & NETIF_F_SG))
		features &= ~NETIF_F_GSO_MASK;

	br->dev->features = features | checksum | NETIF_F_LLTX |
			    NETIF_F_GSO_ROBUST;
}

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

	if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
		return -EINVAL;

	if (dev->hard_start_xmit == br_dev_xmit)
		return -ELOOP;

	if (dev->br_port != NULL)
		return -EBUSY;

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

	err = kobject_add(&p->kobj);
	if (err)
		goto err0;

	err = br_fdb_insert(br, p, dev->dev_addr);
	if (err)
		goto err1;

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

	rcu_assign_pointer(dev->br_port, p);
	dev_set_promiscuity(dev, 1);

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

	spin_lock_bh(&br->lock);
	br_stp_recalculate_bridge_id(br);
	br_features_recompute(br);
	spin_unlock_bh(&br->lock);

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

	kobject_uevent(&p->kobj, KOBJ_ADD);

	return 0;
err2:
	br_fdb_delete_by_port(br, p, 1);
err1:
	kobject_del(&p->kobj);
err0:
	kobject_put(&p->kobj);
	return err;
}

/* called with RTNL */
int br_del_if(struct net_bridge *br, struct net_device *dev)
{
	struct net_bridge_port *p = dev->br_port;

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

	del_nbp(p);

	spin_lock_bh(&br->lock);
	br_stp_recalculate_bridge_id(br);
	br_features_recompute(br);
	spin_unlock_bh(&br->lock);

	return 0;
}

void __exit br_cleanup_bridges(void)
{
	struct net_device *dev, *nxt;

	rtnl_lock();
	for (dev = dev_base; dev; dev = nxt) {
		nxt = dev->next;
		if (dev->priv_flags & IFF_EBRIDGE)
			del_br(dev->priv);
	}
	rtnl_unlock();

}
Commit	Line	Data
	1	/*
	2	* Userspace interface
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
	8	* $Id: br_if.c,v 1.7 2001/12/24 00:59:55 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	#include <linux/netdevice.h>
	18	#include <linux/ethtool.h>
	19	#include <linux/if_arp.h>
	20	#include <linux/module.h>
	21	#include <linux/init.h>
	22	#include <linux/rtnetlink.h>
	23	#include <linux/if_ether.h>
	24	#include <net/sock.h>
	25
	26	#include "br_private.h"
	27
	28	/*
	29	* Determine initial path cost based on speed.
	30	* using recommendations from 802.1d standard
	31	*
	32	* Need to simulate user ioctl because not all device's that support
	33	* ethtool, use ethtool_ops. Also, since driver might sleep need to
	34	* not be holding any locks.
	35	*/
	36	static int port_cost(struct net_device *dev)
	37	{
	38	struct ethtool_cmd ecmd = { ETHTOOL_GSET };
	39	struct ifreq ifr;
	40	mm_segment_t old_fs;
	41	int err;
	42
	43	strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
	44	ifr.ifr_data = (void __user *) &ecmd;
	45
	46	old_fs = get_fs();
	47	set_fs(KERNEL_DS);
	48	err = dev_ethtool(&ifr);
	49	set_fs(old_fs);
	50
	51	if (!err) {
	52	switch(ecmd.speed) {
	53	case SPEED_100:
	54	return 19;
	55	case SPEED_1000:
	56	return 4;
	57	case SPEED_10000:
	58	return 2;
	59	case SPEED_10:
	60	return 100;
	61	}
	62	}
	63
	64	/* Old silly heuristics based on name */
	65	if (!strncmp(dev->name, "lec", 3))
	66	return 7;
	67
	68	if (!strncmp(dev->name, "plip", 4))
	69	return 2500;
	70
	71	return 100; /* assume old 10Mbps */
	72	}
	73
	74
	75	/*
	76	* Check for port carrier transistions.
	77	* Called from work queue to allow for calling functions that
	78	* might sleep (such as speed check), and to debounce.
	79	*/
	80	void br_port_carrier_check(struct net_bridge_port *p)
	81	{
	82	struct net_device *dev = p->dev;
	83	struct net_bridge *br = p->br;
	84
	85	if (netif_carrier_ok(dev))
	86	p->path_cost = port_cost(dev);
	87
	88	if (netif_running(br->dev)) {
	89	spin_lock_bh(&br->lock);
	90	if (netif_carrier_ok(dev)) {
	91	if (p->state == BR_STATE_DISABLED)
	92	br_stp_enable_port(p);
	93	} else {
	94	if (p->state != BR_STATE_DISABLED)
	95	br_stp_disable_port(p);
	96	}
	97	spin_unlock_bh(&br->lock);
	98	}
	99	}
	100
	101	static void release_nbp(struct kobject *kobj)
	102	{
	103	struct net_bridge_port *p
	104	= container_of(kobj, struct net_bridge_port, kobj);
	105	kfree(p);
	106	}
	107
	108	static struct kobj_type brport_ktype = {
	109	#ifdef CONFIG_SYSFS
	110	.sysfs_ops = &brport_sysfs_ops,
	111	#endif
	112	.release = release_nbp,
	113	};
	114
	115	static void destroy_nbp(struct net_bridge_port *p)
	116	{
	117	struct net_device *dev = p->dev;
	118
	119	p->br = NULL;
	120	p->dev = NULL;
	121	dev_put(dev);
	122
	123	kobject_put(&p->kobj);
	124	}
	125
	126	static void destroy_nbp_rcu(struct rcu_head *head)
	127	{
	128	struct net_bridge_port *p =
	129	container_of(head, struct net_bridge_port, rcu);
	130	destroy_nbp(p);
	131	}
	132
	133	/* Delete port(interface) from bridge is done in two steps.
	134	* via RCU. First step, marks device as down. That deletes
	135	* all the timers and stops new packets from flowing through.
	136	*
	137	* Final cleanup doesn't occur until after all CPU's finished
	138	* processing packets.
	139	*
	140	* Protected from multiple admin operations by RTNL mutex
	141	*/
	142	static void del_nbp(struct net_bridge_port *p)
	143	{
	144	struct net_bridge *br = p->br;
	145	struct net_device *dev = p->dev;
	146
	147	sysfs_remove_link(&br->ifobj, dev->name);
	148
	149	dev_set_promiscuity(dev, -1);
	150
	151	spin_lock_bh(&br->lock);
	152	br_stp_disable_port(p);
	153	spin_unlock_bh(&br->lock);
	154
	155	br_fdb_delete_by_port(br, p, 1);
	156
	157	list_del_rcu(&p->list);
	158
	159	rcu_assign_pointer(dev->br_port, NULL);
	160
	161	kobject_uevent(&p->kobj, KOBJ_REMOVE);
	162	kobject_del(&p->kobj);
	163
	164	call_rcu(&p->rcu, destroy_nbp_rcu);
	165	}
	166
	167	/* called with RTNL */
	168	static void del_br(struct net_bridge *br)
	169	{
	170	struct net_bridge_port p, n;
	171
	172	list_for_each_entry_safe(p, n, &br->port_list, list) {
	173	del_nbp(p);
	174	}
	175
	176	del_timer_sync(&br->gc_timer);
	177
	178	br_sysfs_delbr(br->dev);
	179	unregister_netdevice(br->dev);
	180	}
	181
	182	static struct net_device new_bridge_dev(const char name)
	183	{
	184	struct net_bridge *br;
	185	struct net_device *dev;
	186
	187	dev = alloc_netdev(sizeof(struct net_bridge), name,
	188	br_dev_setup);
	189
	190	if (!dev)
	191	return NULL;
	192
	193	br = netdev_priv(dev);
	194	br->dev = dev;
	195
	196	spin_lock_init(&br->lock);
	197	INIT_LIST_HEAD(&br->port_list);
	198	spin_lock_init(&br->hash_lock);
	199
	200	br->bridge_id.prio[0] = 0x80;
	201	br->bridge_id.prio[1] = 0x00;
	202
	203	memcpy(br->group_addr, br_group_address, ETH_ALEN);
	204
	205	br->feature_mask = dev->features;
	206	br->stp_enabled = 0;
	207	br->designated_root = br->bridge_id;
	208	br->root_path_cost = 0;
	209	br->root_port = 0;
	210	br->bridge_max_age = br->max_age = 20 * HZ;
	211	br->bridge_hello_time = br->hello_time = 2 * HZ;
	212	br->bridge_forward_delay = br->forward_delay = 15 * HZ;
	213	br->topology_change = 0;
	214	br->topology_change_detected = 0;
	215	br->ageing_time = 300 * HZ;
	216	INIT_LIST_HEAD(&br->age_list);
	217
	218	br_stp_timer_init(br);
	219
	220	return dev;
	221	}
	222
	223	/* find an available port number */
	224	static int find_portno(struct net_bridge *br)
	225	{
	226	int index;
	227	struct net_bridge_port *p;
	228	unsigned long *inuse;
	229
	230	inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
	231	GFP_KERNEL);
	232	if (!inuse)
	233	return -ENOMEM;
	234
	235	set_bit(0, inuse); /* zero is reserved */
	236	list_for_each_entry(p, &br->port_list, list) {
	237	set_bit(p->port_no, inuse);
	238	}
	239	index = find_first_zero_bit(inuse, BR_MAX_PORTS);
	240	kfree(inuse);
	241
	242	return (index >= BR_MAX_PORTS) ? -EXFULL : index;
	243	}
	244
	245	/* called with RTNL but without bridge lock */
	246	static struct net_bridge_port new_nbp(struct net_bridge br,
	247	struct net_device *dev)
	248	{
	249	int index;
	250	struct net_bridge_port *p;
	251
	252	index = find_portno(br);
	253	if (index < 0)
	254	return ERR_PTR(index);
	255
	256	p = kzalloc(sizeof(*p), GFP_KERNEL);
	257	if (p == NULL)
	258	return ERR_PTR(-ENOMEM);
	259
	260	p->br = br;
	261	dev_hold(dev);
	262	p->dev = dev;
	263	p->path_cost = port_cost(dev);
	264	p->priority = 0x8000 >> BR_PORT_BITS;
	265	p->port_no = index;
	266	br_init_port(p);
	267	p->state = BR_STATE_DISABLED;
	268	br_stp_port_timer_init(p);
	269
	270	kobject_init(&p->kobj);
	271	kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR);
	272	p->kobj.ktype = &brport_ktype;
	273	p->kobj.parent = &(dev->dev.kobj);
	274	p->kobj.kset = NULL;
	275
	276	return p;
	277	}
	278
	279	int br_add_bridge(const char *name)
	280	{
	281	struct net_device *dev;
	282	int ret;
	283
	284	dev = new_bridge_dev(name);
	285	if (!dev)
	286	return -ENOMEM;
	287
	288	rtnl_lock();
	289	if (strchr(dev->name, '%')) {
	290	ret = dev_alloc_name(dev, dev->name);
	291	if (ret < 0) {
	292	free_netdev(dev);
	293	goto out;
	294	}
	295	}
	296
	297	ret = register_netdevice(dev);
	298	if (ret)
	299	goto out;
	300
	301	ret = br_sysfs_addbr(dev);
	302	if (ret)
	303	unregister_netdevice(dev);
	304	out:
	305	rtnl_unlock();
	306	return ret;
	307	}
	308
	309	int br_del_bridge(const char *name)
	310	{
	311	struct net_device *dev;
	312	int ret = 0;
	313
	314	rtnl_lock();
	315	dev = __dev_get_by_name(name);
	316	if (dev == NULL)
	317	ret = -ENXIO; /* Could not find device */
	318
	319	else if (!(dev->priv_flags & IFF_EBRIDGE)) {
	320	/* Attempt to delete non bridge device! */
	321	ret = -EPERM;
	322	}
	323
	324	else if (dev->flags & IFF_UP) {
	325	/* Not shutdown yet. */
	326	ret = -EBUSY;
	327	}
	328
	329	else
	330	del_br(netdev_priv(dev));
	331
	332	rtnl_unlock();
	333	return ret;
	334	}
	335
	336	/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
	337	int br_min_mtu(const struct net_bridge *br)
	338	{
	339	const struct net_bridge_port *p;
	340	int mtu = 0;
	341
	342	ASSERT_RTNL();
	343
	344	if (list_empty(&br->port_list))
	345	mtu = ETH_DATA_LEN;
	346	else {
	347	list_for_each_entry(p, &br->port_list, list) {
	348	if (!mtu \|\| p->dev->mtu < mtu)
	349	mtu = p->dev->mtu;
	350	}
	351	}
	352	return mtu;
	353	}
	354
	355	/*
	356	* Recomputes features using slave's features
	357	*/
	358	void br_features_recompute(struct net_bridge *br)
	359	{
	360	struct net_bridge_port *p;
	361	unsigned long features, checksum;
	362
	363	checksum = br->feature_mask & NETIF_F_ALL_CSUM ? NETIF_F_NO_CSUM : 0;
	364	features = br->feature_mask & ~NETIF_F_ALL_CSUM;
	365
	366	list_for_each_entry(p, &br->port_list, list) {
	367	unsigned long feature = p->dev->features;
	368
	369	if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
	370	checksum ^= NETIF_F_NO_CSUM \| NETIF_F_HW_CSUM;
	371	if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
	372	checksum ^= NETIF_F_HW_CSUM \| NETIF_F_IP_CSUM;
	373	if (!(feature & NETIF_F_IP_CSUM))
	374	checksum = 0;
	375
	376	if (feature & NETIF_F_GSO)
	377	feature \|= NETIF_F_GSO_SOFTWARE;
	378	feature \|= NETIF_F_GSO;
	379
	380	features &= feature;
	381	}
	382
	383	if (!(checksum & NETIF_F_ALL_CSUM))
	384	features &= ~NETIF_F_SG;
	385	if (!(features & NETIF_F_SG))
	386	features &= ~NETIF_F_GSO_MASK;
	387
	388	br->dev->features = features \| checksum \| NETIF_F_LLTX \|
	389	NETIF_F_GSO_ROBUST;
	390	}
	391
	392	/* called with RTNL */
	393	int br_add_if(struct net_bridge br, struct net_device dev)
	394	{
	395	struct net_bridge_port *p;
	396	int err = 0;
	397
	398	if (dev->flags & IFF_LOOPBACK \|\| dev->type != ARPHRD_ETHER)
	399	return -EINVAL;
	400
	401	if (dev->hard_start_xmit == br_dev_xmit)
	402	return -ELOOP;
	403
	404	if (dev->br_port != NULL)
	405	return -EBUSY;
	406
	407	p = new_nbp(br, dev);
	408	if (IS_ERR(p))
	409	return PTR_ERR(p);
	410
	411	err = kobject_add(&p->kobj);
	412	if (err)
	413	goto err0;
	414
	415	err = br_fdb_insert(br, p, dev->dev_addr);
	416	if (err)
	417	goto err1;
	418
	419	err = br_sysfs_addif(p);
	420	if (err)
	421	goto err2;
	422
	423	rcu_assign_pointer(dev->br_port, p);
	424	dev_set_promiscuity(dev, 1);
	425
	426	list_add_rcu(&p->list, &br->port_list);
	427
	428	spin_lock_bh(&br->lock);
	429	br_stp_recalculate_bridge_id(br);
	430	br_features_recompute(br);
	431	spin_unlock_bh(&br->lock);
	432
	433	dev_set_mtu(br->dev, br_min_mtu(br));
	434
	435	kobject_uevent(&p->kobj, KOBJ_ADD);
	436
	437	return 0;
	438	err2:
	439	br_fdb_delete_by_port(br, p, 1);
	440	err1:
	441	kobject_del(&p->kobj);
	442	err0:
	443	kobject_put(&p->kobj);
	444	return err;
	445	}
	446
	447	/* called with RTNL */
	448	int br_del_if(struct net_bridge br, struct net_device dev)
	449	{
	450	struct net_bridge_port *p = dev->br_port;
	451
	452	if (!p \|\| p->br != br)
	453	return -EINVAL;
	454
	455	del_nbp(p);
	456
	457	spin_lock_bh(&br->lock);
	458	br_stp_recalculate_bridge_id(br);
	459	br_features_recompute(br);
	460	spin_unlock_bh(&br->lock);
	461
	462	return 0;
	463	}
	464
	465	void __exit br_cleanup_bridges(void)
	466	{
	467	struct net_device dev, nxt;
	468
	469	rtnl_lock();
	470	for (dev = dev_base; dev; dev = nxt) {
	471	nxt = dev->next;
	472	if (dev->priv_flags & IFF_EBRIDGE)
	473	del_br(dev->priv);
	474	}
	475	rtnl_unlock();
	476
	477	}