net/bridge/br_ioctl.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	Ioctl handler
  *	Linux ethernet bridge
  *
  *	Authors:
  *	Lennert Buytenhek		<buytenh@gnu.org>
  */

 #include <linux/capability.h>
 #include <linux/kernel.h>
 #include <linux/if_bridge.h>
 #include <linux/netdevice.h>
 #include <linux/slab.h>
 #include <linux/times.h>
 #include <net/net_namespace.h>
 #include <linux/uaccess.h>
 #include "br_private.h"

 static int get_bridge_ifindices(struct net *net, int *indices, int num)
 {
 	struct net_device *dev;
 	int i = 0;

 	rcu_read_lock();
 	for_each_netdev_rcu(net, dev) {
 		if (i >= num)
 			break;
 		if (netif_is_bridge_master(dev))
 			indices[i++] = dev->ifindex;
 	}
 	rcu_read_unlock();

 	return i;
 }

 /* called with RTNL */
 static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
 {
 	struct net_bridge_port *p;

 	list_for_each_entry(p, &br->port_list, list) {
 		if (p->port_no < num)
 			ifindices[p->port_no] = p->dev->ifindex;
 	}
 }

 /*
  * Format up to a page worth of forwarding table entries
  * userbuf -- where to copy result
  * maxnum  -- maximum number of entries desired
  *            (limited to a page for sanity)
  * offset  -- number of records to skip
  */
 static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
 			   unsigned long maxnum, unsigned long offset)
 {
 	int num;
 	void *buf;
 	size_t size;

 	/* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
 	if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
 		maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);

 	size = maxnum * sizeof(struct __fdb_entry);

 	buf = kmalloc(size, GFP_USER);
 	if (!buf)
 		return -ENOMEM;

 	num = br_fdb_fillbuf(br, buf, maxnum, offset);
 	if (num > 0) {
 		if (copy_to_user(userbuf, buf,
 				 array_size(num, sizeof(struct __fdb_entry))))
 			num = -EFAULT;
 	}
 	kfree(buf);

 	return num;
 }

 /* called with RTNL */
 static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
 {
 	struct net *net = dev_net(br->dev);
 	struct net_device *dev;
 	int ret;

 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;

 	dev = __dev_get_by_index(net, ifindex);
 	if (dev == NULL)
 		return -EINVAL;

 	if (isadd)
 		ret = br_add_if(br, dev, NULL);
 	else
 		ret = br_del_if(br, dev);

 	return ret;
 }

 /*
  * Legacy ioctl's through SIOCDEVPRIVATE
  * This interface is deprecated because it was too difficult
  * to do the translation for 32/64bit ioctl compatibility.
  */
 int br_dev_siocdevprivate(struct net_device *dev, struct ifreq *rq, void __user *data, int cmd)
 {
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *p = NULL;
 	unsigned long args[4];
 	void __user *argp;
 	int ret = -EOPNOTSUPP;

 	if (in_compat_syscall()) {
 		unsigned int cargs[4];

 		if (copy_from_user(cargs, data, sizeof(cargs)))
 			return -EFAULT;

 		args[0] = cargs[0];
 		args[1] = cargs[1];
 		args[2] = cargs[2];
 		args[3] = cargs[3];

 		argp = compat_ptr(args[1]);
 	} else {
 		if (copy_from_user(args, data, sizeof(args)))
 			return -EFAULT;

 		argp = (void __user *)args[1];
 	}

 	switch (args[0]) {
 	case BRCTL_ADD_IF:
 	case BRCTL_DEL_IF:
 		return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);

 	case BRCTL_GET_BRIDGE_INFO:
 	{
 		struct __bridge_info b;

 		memset(&b, 0, sizeof(struct __bridge_info));
 		rcu_read_lock();
 		memcpy(&b.designated_root, &br->designated_root, 8);
 		memcpy(&b.bridge_id, &br->bridge_id, 8);
 		b.root_path_cost = br->root_path_cost;
 		b.max_age = jiffies_to_clock_t(br->max_age);
 		b.hello_time = jiffies_to_clock_t(br->hello_time);
 		b.forward_delay = br->forward_delay;
 		b.bridge_max_age = br->bridge_max_age;
 		b.bridge_hello_time = br->bridge_hello_time;
 		b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
 		b.topology_change = br->topology_change;
 		b.topology_change_detected = br->topology_change_detected;
 		b.root_port = br->root_port;

 		b.stp_enabled = (br->stp_enabled != BR_NO_STP);
 		b.ageing_time = jiffies_to_clock_t(br->ageing_time);
 		b.hello_timer_value = br_timer_value(&br->hello_timer);
 		b.tcn_timer_value = br_timer_value(&br->tcn_timer);
 		b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
 		b.gc_timer_value = br_timer_value(&br->gc_work.timer);
 		rcu_read_unlock();

 		if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
 			return -EFAULT;

 		return 0;
 	}

 	case BRCTL_GET_PORT_LIST:
 	{
 		int num, *indices;

 		num = args[2];
 		if (num < 0)
 			return -EINVAL;
 		if (num == 0)
 			num = 256;
 		if (num > BR_MAX_PORTS)
 			num = BR_MAX_PORTS;

 		indices = kcalloc(num, sizeof(int), GFP_KERNEL);
 		if (indices == NULL)
 			return -ENOMEM;

 		get_port_ifindices(br, indices, num);
 		if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
 			num =  -EFAULT;
 		kfree(indices);
 		return num;
 	}

 	case BRCTL_SET_BRIDGE_FORWARD_DELAY:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		ret = br_set_forward_delay(br, args[1]);
 		break;

 	case BRCTL_SET_BRIDGE_HELLO_TIME:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		ret = br_set_hello_time(br, args[1]);
 		break;

 	case BRCTL_SET_BRIDGE_MAX_AGE:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		ret = br_set_max_age(br, args[1]);
 		break;

 	case BRCTL_SET_AGEING_TIME:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		ret = br_set_ageing_time(br, args[1]);
 		break;

 	case BRCTL_GET_PORT_INFO:
 	{
 		struct __port_info p;
 		struct net_bridge_port *pt;

 		rcu_read_lock();
 		if ((pt = br_get_port(br, args[2])) == NULL) {
 			rcu_read_unlock();
 			return -EINVAL;
 		}

 		memset(&p, 0, sizeof(struct __port_info));
 		memcpy(&p.designated_root, &pt->designated_root, 8);
 		memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
 		p.port_id = pt->port_id;
 		p.designated_port = pt->designated_port;
 		p.path_cost = pt->path_cost;
 		p.designated_cost = pt->designated_cost;
 		p.state = pt->state;
 		p.top_change_ack = pt->topology_change_ack;
 		p.config_pending = pt->config_pending;
 		p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
 		p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
 		p.hold_timer_value = br_timer_value(&pt->hold_timer);

 		rcu_read_unlock();

 		if (copy_to_user(argp, &p, sizeof(p)))
 			return -EFAULT;

 		return 0;
 	}

 	case BRCTL_SET_BRIDGE_STP_STATE:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		ret = br_stp_set_enabled(br, args[1], NULL);
 		break;

 	case BRCTL_SET_BRIDGE_PRIORITY:
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		br_stp_set_bridge_priority(br, args[1]);
 		ret = 0;
 		break;

 	case BRCTL_SET_PORT_PRIORITY:
 	{
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		spin_lock_bh(&br->lock);
 		if ((p = br_get_port(br, args[1])) == NULL)
 			ret = -EINVAL;
 		else
 			ret = br_stp_set_port_priority(p, args[2]);
 		spin_unlock_bh(&br->lock);
 		break;
 	}

 	case BRCTL_SET_PATH_COST:
 	{
 		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		spin_lock_bh(&br->lock);
 		if ((p = br_get_port(br, args[1])) == NULL)
 			ret = -EINVAL;
 		else
 			ret = br_stp_set_path_cost(p, args[2]);
 		spin_unlock_bh(&br->lock);
 		break;
 	}

 	case BRCTL_GET_FDB_ENTRIES:
 		return get_fdb_entries(br, argp, args[2], args[3]);
 	}

 	if (!ret) {
 		if (p)
 			br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 		else
 			netdev_state_change(br->dev);
 	}

 	return ret;
 }

 static int old_deviceless(struct net *net, void __user *uarg)
 {
 	unsigned long args[3];

 	if (copy_from_user(args, uarg, sizeof(args)))
 		return -EFAULT;

 	switch (args[0]) {
 	case BRCTL_GET_VERSION:
 		return BRCTL_VERSION;

 	case BRCTL_GET_BRIDGES:
 	{
 		int *indices;
 		int ret = 0;

 		if (args[2] >= 2048)
 			return -ENOMEM;
 		indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
 		if (indices == NULL)
 			return -ENOMEM;

 		args[2] = get_bridge_ifindices(net, indices, args[2]);

 		ret = copy_to_user((void __user *)args[1], indices,
 				   array_size(args[2], sizeof(int)))
 			? -EFAULT : args[2];

 		kfree(indices);
 		return ret;
 	}

 	case BRCTL_ADD_BRIDGE:
 	case BRCTL_DEL_BRIDGE:
 	{
 		char buf[IFNAMSIZ];

 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;

 		if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
 			return -EFAULT;

 		buf[IFNAMSIZ-1] = 0;

 		if (args[0] == BRCTL_ADD_BRIDGE)
 			return br_add_bridge(net, buf);

 		return br_del_bridge(net, buf);
 	}
 	}

 	return -EOPNOTSUPP;
 }

 int br_ioctl_stub(struct net *net, struct net_bridge *br, unsigned int cmd,
 		  struct ifreq *ifr, void __user *uarg)
 {
 	int ret = -EOPNOTSUPP;

 	rtnl_lock();

 	switch (cmd) {
 	case SIOCGIFBR:
 	case SIOCSIFBR:
 		ret = old_deviceless(net, uarg);
 		break;
 	case SIOCBRADDBR:
 	case SIOCBRDELBR:
 	{
 		char buf[IFNAMSIZ];

 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 			ret = -EPERM;
 			break;
 		}

 		if (copy_from_user(buf, uarg, IFNAMSIZ)) {
 			ret = -EFAULT;
 			break;
 		}

 		buf[IFNAMSIZ-1] = 0;
 		if (cmd == SIOCBRADDBR)
 			ret = br_add_bridge(net, buf);
 		else
 			ret = br_del_bridge(net, buf);
 	}
 		break;
 	case SIOCBRADDIF:
 	case SIOCBRDELIF:
 		ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
 		break;
 	}

 	rtnl_unlock();

 	return ret;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Ioctl handler
	* Linux ethernet bridge
	*
	* Authors:
	* Lennert Buytenhek <buytenh@gnu.org>
	*/

	#include <linux/capability.h>
	#include <linux/kernel.h>
	#include <linux/if_bridge.h>
	#include <linux/netdevice.h>
	#include <linux/slab.h>
	#include <linux/times.h>
	#include <net/net_namespace.h>
	#include <linux/uaccess.h>
	#include "br_private.h"

	static int get_bridge_ifindices(struct net net, int indices, int num)
	{
	struct net_device *dev;
	int i = 0;

	rcu_read_lock();
	for_each_netdev_rcu(net, dev) {
	if (i >= num)
	break;
	if (netif_is_bridge_master(dev))
	indices[i++] = dev->ifindex;
	}
	rcu_read_unlock();

	return i;
	}

	/* called with RTNL */
	static void get_port_ifindices(struct net_bridge br, int ifindices, int num)
	{
	struct net_bridge_port *p;

	list_for_each_entry(p, &br->port_list, list) {
	if (p->port_no < num)
	ifindices[p->port_no] = p->dev->ifindex;
	}
	}

	/*
	* Format up to a page worth of forwarding table entries
	* userbuf -- where to copy result
	* maxnum -- maximum number of entries desired
	* (limited to a page for sanity)
	* offset -- number of records to skip
	*/
	static int get_fdb_entries(struct net_bridge br, void __user userbuf,
	unsigned long maxnum, unsigned long offset)
	{
	int num;
	void *buf;
	size_t size;

	/* Clamp size to PAGE_SIZE, test maxnum to avoid overflow */
	if (maxnum > PAGE_SIZE/sizeof(struct __fdb_entry))
	maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);

	size = maxnum * sizeof(struct __fdb_entry);

	buf = kmalloc(size, GFP_USER);
	if (!buf)
	return -ENOMEM;

	num = br_fdb_fillbuf(br, buf, maxnum, offset);
	if (num > 0) {
	if (copy_to_user(userbuf, buf,
	array_size(num, sizeof(struct __fdb_entry))))
	num = -EFAULT;
	}
	kfree(buf);

	return num;
	}

	/* called with RTNL */
	static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
	{
	struct net *net = dev_net(br->dev);
	struct net_device *dev;
	int ret;

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	dev = __dev_get_by_index(net, ifindex);
	if (dev == NULL)
	return -EINVAL;

	if (isadd)
	ret = br_add_if(br, dev, NULL);
	else
	ret = br_del_if(br, dev);

	return ret;
	}

	/*
	* Legacy ioctl's through SIOCDEVPRIVATE
	* This interface is deprecated because it was too difficult
	* to do the translation for 32/64bit ioctl compatibility.
	*/
	int br_dev_siocdevprivate(struct net_device dev, struct ifreq rq, void __user *data, int cmd)
	{
	struct net_bridge *br = netdev_priv(dev);
	struct net_bridge_port *p = NULL;
	unsigned long args[4];
	void __user *argp;
	int ret = -EOPNOTSUPP;

	if (in_compat_syscall()) {
	unsigned int cargs[4];

	if (copy_from_user(cargs, data, sizeof(cargs)))
	return -EFAULT;

	args[0] = cargs[0];
	args[1] = cargs[1];
	args[2] = cargs[2];
	args[3] = cargs[3];

	argp = compat_ptr(args[1]);
	} else {
	if (copy_from_user(args, data, sizeof(args)))
	return -EFAULT;

	argp = (void __user *)args[1];
	}

	switch (args[0]) {
	case BRCTL_ADD_IF:
	case BRCTL_DEL_IF:
	return add_del_if(br, args[1], args[0] == BRCTL_ADD_IF);

	case BRCTL_GET_BRIDGE_INFO:
	{
	struct __bridge_info b;

	memset(&b, 0, sizeof(struct __bridge_info));
	rcu_read_lock();
	memcpy(&b.designated_root, &br->designated_root, 8);
	memcpy(&b.bridge_id, &br->bridge_id, 8);
	b.root_path_cost = br->root_path_cost;
	b.max_age = jiffies_to_clock_t(br->max_age);
	b.hello_time = jiffies_to_clock_t(br->hello_time);
	b.forward_delay = br->forward_delay;
	b.bridge_max_age = br->bridge_max_age;
	b.bridge_hello_time = br->bridge_hello_time;
	b.bridge_forward_delay = jiffies_to_clock_t(br->bridge_forward_delay);
	b.topology_change = br->topology_change;
	b.topology_change_detected = br->topology_change_detected;
	b.root_port = br->root_port;

	b.stp_enabled = (br->stp_enabled != BR_NO_STP);
	b.ageing_time = jiffies_to_clock_t(br->ageing_time);
	b.hello_timer_value = br_timer_value(&br->hello_timer);
	b.tcn_timer_value = br_timer_value(&br->tcn_timer);
	b.topology_change_timer_value = br_timer_value(&br->topology_change_timer);
	b.gc_timer_value = br_timer_value(&br->gc_work.timer);
	rcu_read_unlock();

	if (copy_to_user((void __user *)args[1], &b, sizeof(b)))
	return -EFAULT;

	return 0;
	}

	case BRCTL_GET_PORT_LIST:
	{
	int num, *indices;

	num = args[2];
	if (num < 0)
	return -EINVAL;
	if (num == 0)
	num = 256;
	if (num > BR_MAX_PORTS)
	num = BR_MAX_PORTS;

	indices = kcalloc(num, sizeof(int), GFP_KERNEL);
	if (indices == NULL)
	return -ENOMEM;

	get_port_ifindices(br, indices, num);
	if (copy_to_user(argp, indices, array_size(num, sizeof(int))))
	num = -EFAULT;
	kfree(indices);
	return num;
	}

	case BRCTL_SET_BRIDGE_FORWARD_DELAY:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	ret = br_set_forward_delay(br, args[1]);
	break;

	case BRCTL_SET_BRIDGE_HELLO_TIME:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	ret = br_set_hello_time(br, args[1]);
	break;

	case BRCTL_SET_BRIDGE_MAX_AGE:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	ret = br_set_max_age(br, args[1]);
	break;

	case BRCTL_SET_AGEING_TIME:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	ret = br_set_ageing_time(br, args[1]);
	break;

	case BRCTL_GET_PORT_INFO:
	{
	struct __port_info p;
	struct net_bridge_port *pt;

	rcu_read_lock();
	if ((pt = br_get_port(br, args[2])) == NULL) {
	rcu_read_unlock();
	return -EINVAL;
	}

	memset(&p, 0, sizeof(struct __port_info));
	memcpy(&p.designated_root, &pt->designated_root, 8);
	memcpy(&p.designated_bridge, &pt->designated_bridge, 8);
	p.port_id = pt->port_id;
	p.designated_port = pt->designated_port;
	p.path_cost = pt->path_cost;
	p.designated_cost = pt->designated_cost;
	p.state = pt->state;
	p.top_change_ack = pt->topology_change_ack;
	p.config_pending = pt->config_pending;
	p.message_age_timer_value = br_timer_value(&pt->message_age_timer);
	p.forward_delay_timer_value = br_timer_value(&pt->forward_delay_timer);
	p.hold_timer_value = br_timer_value(&pt->hold_timer);

	rcu_read_unlock();

	if (copy_to_user(argp, &p, sizeof(p)))
	return -EFAULT;

	return 0;
	}

	case BRCTL_SET_BRIDGE_STP_STATE:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	ret = br_stp_set_enabled(br, args[1], NULL);
	break;

	case BRCTL_SET_BRIDGE_PRIORITY:
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	br_stp_set_bridge_priority(br, args[1]);
	ret = 0;
	break;

	case BRCTL_SET_PORT_PRIORITY:
	{
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	spin_lock_bh(&br->lock);
	if ((p = br_get_port(br, args[1])) == NULL)
	ret = -EINVAL;
	else
	ret = br_stp_set_port_priority(p, args[2]);
	spin_unlock_bh(&br->lock);
	break;
	}

	case BRCTL_SET_PATH_COST:
	{
	if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	spin_lock_bh(&br->lock);
	if ((p = br_get_port(br, args[1])) == NULL)
	ret = -EINVAL;
	else
	ret = br_stp_set_path_cost(p, args[2]);
	spin_unlock_bh(&br->lock);
	break;
	}

	case BRCTL_GET_FDB_ENTRIES:
	return get_fdb_entries(br, argp, args[2], args[3]);
	}

	if (!ret) {
	if (p)
	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
	else
	netdev_state_change(br->dev);
	}

	return ret;
	}

	static int old_deviceless(struct net net, void __user uarg)
	{
	unsigned long args[3];

	if (copy_from_user(args, uarg, sizeof(args)))
	return -EFAULT;

	switch (args[0]) {
	case BRCTL_GET_VERSION:
	return BRCTL_VERSION;

	case BRCTL_GET_BRIDGES:
	{
	int *indices;
	int ret = 0;

	if (args[2] >= 2048)
	return -ENOMEM;
	indices = kcalloc(args[2], sizeof(int), GFP_KERNEL);
	if (indices == NULL)
	return -ENOMEM;

	args[2] = get_bridge_ifindices(net, indices, args[2]);

	ret = copy_to_user((void __user *)args[1], indices,
	array_size(args[2], sizeof(int)))
	? -EFAULT : args[2];

	kfree(indices);
	return ret;
	}

	case BRCTL_ADD_BRIDGE:
	case BRCTL_DEL_BRIDGE:
	{
	char buf[IFNAMSIZ];

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	return -EPERM;

	if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
	return -EFAULT;

	buf[IFNAMSIZ-1] = 0;

	if (args[0] == BRCTL_ADD_BRIDGE)
	return br_add_bridge(net, buf);

	return br_del_bridge(net, buf);
	}
	}

	return -EOPNOTSUPP;
	}

	int br_ioctl_stub(struct net net, struct net_bridge br, unsigned int cmd,
	struct ifreq ifr, void __user uarg)
	{
	int ret = -EOPNOTSUPP;

	rtnl_lock();

	switch (cmd) {
	case SIOCGIFBR:
	case SIOCSIFBR:
	ret = old_deviceless(net, uarg);
	break;
	case SIOCBRADDBR:
	case SIOCBRDELBR:
	{
	char buf[IFNAMSIZ];

	if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
	ret = -EPERM;
	break;
	}

	if (copy_from_user(buf, uarg, IFNAMSIZ)) {
	ret = -EFAULT;
	break;
	}

	buf[IFNAMSIZ-1] = 0;
	if (cmd == SIOCBRADDBR)
	ret = br_add_bridge(net, buf);
	else
	ret = br_del_bridge(net, buf);
	}
	break;
	case SIOCBRADDIF:
	case SIOCBRDELIF:
	ret = add_del_if(br, ifr->ifr_ifindex, cmd == SIOCBRADDIF);
	break;
	}

	rtnl_unlock();

	return ret;
	}