[mirror_ubuntu-eoan-kernel.git] / net / bridge / br_stp_if.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Spanning tree protocol; interface code
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 */

#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/switchdev.h>

#include "br_private.h"
#include "br_private_stp.h"


/* Port id is composed of priority and port number.
 * NB: some bits of priority are dropped to
 *     make room for more ports.
 */
static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
{
	return ((u16)priority << BR_PORT_BITS)
		| (port_no & ((1<<BR_PORT_BITS)-1));
}

#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)

/* called under bridge lock */
void br_init_port(struct net_bridge_port *p)
{
	int err;

	p->port_id = br_make_port_id(p->priority, p->port_no);
	br_become_designated_port(p);
	br_set_state(p, BR_STATE_BLOCKING);
	p->topology_change_ack = 0;
	p->config_pending = 0;

	err = __set_ageing_time(p->dev, p->br->ageing_time);
	if (err)
		netdev_err(p->dev, "failed to offload ageing time\n");
}

/* NO locks held */
void br_stp_enable_bridge(struct net_bridge *br)
{
	struct net_bridge_port *p;

	spin_lock_bh(&br->lock);
	if (br->stp_enabled == BR_KERNEL_STP)
		mod_timer(&br->hello_timer, jiffies + br->hello_time);
	mod_delayed_work(system_long_wq, &br->gc_work, HZ / 10);

	br_config_bpdu_generation(br);

	list_for_each_entry(p, &br->port_list, list) {
		if (netif_running(p->dev) && netif_oper_up(p->dev))
			br_stp_enable_port(p);

	}
	spin_unlock_bh(&br->lock);
}

/* NO locks held */
void br_stp_disable_bridge(struct net_bridge *br)
{
	struct net_bridge_port *p;

	spin_lock_bh(&br->lock);
	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED)
			br_stp_disable_port(p);

	}

	__br_set_topology_change(br, 0);
	br->topology_change_detected = 0;
	spin_unlock_bh(&br->lock);

	del_timer_sync(&br->hello_timer);
	del_timer_sync(&br->topology_change_timer);
	del_timer_sync(&br->tcn_timer);
	cancel_delayed_work_sync(&br->gc_work);
}

/* called under bridge lock */
void br_stp_enable_port(struct net_bridge_port *p)
{
	br_init_port(p);
	br_port_state_selection(p->br);
	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
}

/* called under bridge lock */
void br_stp_disable_port(struct net_bridge_port *p)
{
	struct net_bridge *br = p->br;
	int wasroot;

	wasroot = br_is_root_bridge(br);
	br_become_designated_port(p);
	br_set_state(p, BR_STATE_DISABLED);
	p->topology_change_ack = 0;
	p->config_pending = 0;

	br_ifinfo_notify(RTM_NEWLINK, NULL, p);

	del_timer(&p->message_age_timer);
	del_timer(&p->forward_delay_timer);
	del_timer(&p->hold_timer);

	if (!rcu_access_pointer(p->backup_port))
		br_fdb_delete_by_port(br, p, 0, 0);
	br_multicast_disable_port(p);

	br_configuration_update(br);

	br_port_state_selection(br);

	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
}

static int br_stp_call_user(struct net_bridge *br, char *arg)
{
	char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL };
	char *envp[] = { NULL };
	int rc;

	/* call userspace STP and report program errors */
	rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	if (rc > 0) {
		if (rc & 0xff)
			br_debug(br, BR_STP_PROG " received signal %d\n",
				 rc & 0x7f);
		else
			br_debug(br, BR_STP_PROG " exited with code %d\n",
				 (rc >> 8) & 0xff);
	}

	return rc;
}

static void br_stp_start(struct net_bridge *br)
{
	int err = -ENOENT;

	if (net_eq(dev_net(br->dev), &init_net))
		err = br_stp_call_user(br, "start");

	if (err && err != -ENOENT)
		br_err(br, "failed to start userspace STP (%d)\n", err);

	spin_lock_bh(&br->lock);

	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
		__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
		__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);

	if (!err) {
		br->stp_enabled = BR_USER_STP;
		br_debug(br, "userspace STP started\n");
	} else {
		br->stp_enabled = BR_KERNEL_STP;
		br_debug(br, "using kernel STP\n");

		/* To start timers on any ports left in blocking */
		if (br->dev->flags & IFF_UP)
			mod_timer(&br->hello_timer, jiffies + br->hello_time);
		br_port_state_selection(br);
	}

	spin_unlock_bh(&br->lock);
}

static void br_stp_stop(struct net_bridge *br)
{
	int err;

	if (br->stp_enabled == BR_USER_STP) {
		err = br_stp_call_user(br, "stop");
		if (err)
			br_err(br, "failed to stop userspace STP (%d)\n", err);

		/* To start timers on any ports left in blocking */
		spin_lock_bh(&br->lock);
		br_port_state_selection(br);
		spin_unlock_bh(&br->lock);
	}

	br->stp_enabled = BR_NO_STP;
}

void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
{
	ASSERT_RTNL();

	if (val) {
		if (br->stp_enabled == BR_NO_STP)
			br_stp_start(br);
	} else {
		if (br->stp_enabled != BR_NO_STP)
			br_stp_stop(br);
	}
}

/* called under bridge lock */
void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
{
	/* should be aligned on 2 bytes for ether_addr_equal() */
	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
	struct net_bridge_port *p;
	int wasroot;

	wasroot = br_is_root_bridge(br);

	br_fdb_change_mac_address(br, addr);

	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	memcpy(br->dev->dev_addr, addr, ETH_ALEN);

	list_for_each_entry(p, &br->port_list, list) {
		if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
			memcpy(p->designated_bridge.addr, addr, ETH_ALEN);

		if (ether_addr_equal(p->designated_root.addr, oldaddr))
			memcpy(p->designated_root.addr, addr, ETH_ALEN);
	}

	br_configuration_update(br);
	br_port_state_selection(br);
	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
}

/* should be aligned on 2 bytes for ether_addr_equal() */
static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];

/* called under bridge lock */
bool br_stp_recalculate_bridge_id(struct net_bridge *br)
{
	const unsigned char *br_mac_zero =
			(const unsigned char *)br_mac_zero_aligned;
	const unsigned char *addr = br_mac_zero;
	struct net_bridge_port *p;

	/* user has chosen a value so keep it */
	if (br->dev->addr_assign_type == NET_ADDR_SET)
		return false;

	list_for_each_entry(p, &br->port_list, list) {
		if (addr == br_mac_zero ||
		    memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
			addr = p->dev->dev_addr;

	}

	if (ether_addr_equal(br->bridge_id.addr, addr))
		return false;	/* no change */

	br_stp_change_bridge_id(br, addr);
	return true;
}

/* Acquires and releases bridge lock */
void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
{
	struct net_bridge_port *p;
	int wasroot;

	spin_lock_bh(&br->lock);
	wasroot = br_is_root_bridge(br);

	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED &&
		    br_is_designated_port(p)) {
			p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
			p->designated_bridge.prio[1] = newprio & 0xFF;
		}

	}

	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	br->bridge_id.prio[1] = newprio & 0xFF;
	br_configuration_update(br);
	br_port_state_selection(br);
	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
	spin_unlock_bh(&br->lock);
}

/* called under bridge lock */
int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
{
	port_id new_port_id;

	if (newprio > BR_MAX_PORT_PRIORITY)
		return -ERANGE;

	new_port_id = br_make_port_id(newprio, p->port_no);
	if (br_is_designated_port(p))
		p->designated_port = new_port_id;

	p->port_id = new_port_id;
	p->priority = newprio;
	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	    p->port_id < p->designated_port) {
		br_become_designated_port(p);
		br_port_state_selection(p->br);
	}

	return 0;
}

/* called under bridge lock */
int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
{
	if (path_cost < BR_MIN_PATH_COST ||
	    path_cost > BR_MAX_PATH_COST)
		return -ERANGE;

	p->flags |= BR_ADMIN_COST;
	p->path_cost = path_cost;
	br_configuration_update(p->br);
	br_port_state_selection(p->br);
	return 0;
}

ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
{
	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	       id->prio[0], id->prio[1],
	       id->addr[0], id->addr[1], id->addr[2],
	       id->addr[3], id->addr[4], id->addr[5]);
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Spanning tree protocol; interface code
	4	* Linux ethernet bridge
	5	*
	6	* Authors:
	7	* Lennert Buytenhek <buytenh@gnu.org>
1da177e4 LT	8	*/
	9
	10	#include <linux/kernel.h>
79bb1ee4	11	#include <linux/kmod.h>
6ede2463	12	#include <linux/etherdevice.h>
11dc1f36	13	#include <linux/rtnetlink.h>
6ac311ae	14	#include <net/switchdev.h>
1da177e4 LT	15
	16	#include "br_private.h"
	17	#include "br_private_stp.h"
	18
	19
	20	/* Port id is composed of priority and port number.
14f98f25	21	* NB: some bits of priority are dropped to
1da177e4 LT	22	* make room for more ports.
	23	*/
	24	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	25	{
9d6f229f	26	return ((u16)priority << BR_PORT_BITS)
1da177e4 LT	27	\| (port_no & ((1<<BR_PORT_BITS)-1));
	28	}
	29
14f98f25	30	#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
14f98f25	31
1da177e4 LT	32	/* called under bridge lock */
	33	void br_init_port(struct net_bridge_port *p)
	34	{
6ac311ae ER	35	int err;
6ac311ae ER	36
1da177e4 LT	37	p->port_id = br_make_port_id(p->priority, p->port_no);
1da177e4 LT	38	br_become_designated_port(p);
775dd692	39	br_set_state(p, BR_STATE_BLOCKING);
1da177e4 LT	40	p->topology_change_ack = 0;
1da177e4 LT	41	p->config_pending = 0;
6ac311ae	42
82dd4332 VD	43	err = __set_ageing_time(p->dev, p->br->ageing_time);
	44	if (err)
	45	netdev_err(p->dev, "failed to offload ageing time\n");
1da177e4 LT	46	}
1da177e4 LT	47
dba479f3	48	/* NO locks held */
1da177e4 LT	49	void br_stp_enable_bridge(struct net_bridge *br)
	50	{
	51	struct net_bridge_port *p;
	52
	53	spin_lock_bh(&br->lock);
76b91c32 NA	54	if (br->stp_enabled == BR_KERNEL_STP)
76b91c32 NA	55	mod_timer(&br->hello_timer, jiffies + br->hello_time);
f7cdee8a	56	mod_delayed_work(system_long_wq, &br->gc_work, HZ / 10);
9d6f229f	57
1da177e4 LT	58	br_config_bpdu_generation(br);
	59
	60	list_for_each_entry(p, &br->port_list, list) {
576eb625	61	if (netif_running(p->dev) && netif_oper_up(p->dev))
1da177e4 LT	62	br_stp_enable_port(p);
	63
	64	}
	65	spin_unlock_bh(&br->lock);
	66	}
	67
	68	/* NO locks held */
	69	void br_stp_disable_bridge(struct net_bridge *br)
	70	{
	71	struct net_bridge_port *p;
	72
78872ccb	73	spin_lock_bh(&br->lock);
1da177e4 LT	74	list_for_each_entry(p, &br->port_list, list) {
	75	if (p->state != BR_STATE_DISABLED)
	76	br_stp_disable_port(p);
	77
	78	}
	79
8384b5f5	80	__br_set_topology_change(br, 0);
1da177e4	81	br->topology_change_detected = 0;
78872ccb	82	spin_unlock_bh(&br->lock);
1da177e4 LT	83
	84	del_timer_sync(&br->hello_timer);
	85	del_timer_sync(&br->topology_change_timer);
	86	del_timer_sync(&br->tcn_timer);
f7cdee8a	87	cancel_delayed_work_sync(&br->gc_work);
1da177e4 LT	88	}
	89
	90	/* called under bridge lock */
	91	void br_stp_enable_port(struct net_bridge_port *p)
	92	{
	93	br_init_port(p);
	94	br_port_state_selection(p->br);
92899063	95	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
1da177e4 LT	96	}
	97
	98	/* called under bridge lock */
	99	void br_stp_disable_port(struct net_bridge_port *p)
	100	{
28a16c97	101	struct net_bridge *br = p->br;
1da177e4 LT	102	int wasroot;
1da177e4 LT	103
1da177e4 LT	104	wasroot = br_is_root_bridge(br);
1da177e4 LT	105	br_become_designated_port(p);
775dd692	106	br_set_state(p, BR_STATE_DISABLED);
1da177e4 LT	107	p->topology_change_ack = 0;
	108	p->config_pending = 0;
	109
92899063	110	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
4ecb961c	111
1da177e4 LT	112	del_timer(&p->message_age_timer);
	113	del_timer(&p->forward_delay_timer);
	114	del_timer(&p->hold_timer);
	115
8dc35020 NA	116	if (!rcu_access_pointer(p->backup_port))
8dc35020 NA	117	br_fdb_delete_by_port(br, p, 0, 0);
3fe2d7c7	118	br_multicast_disable_port(p);
1a620698	119
1da177e4 LT	120	br_configuration_update(br);
	121
	122	br_port_state_selection(br);
	123
	124	if (br_is_root_bridge(br) && !wasroot)
	125	br_become_root_bridge(br);
	126	}
	127
30843315	128	static int br_stp_call_user(struct net_bridge br, char arg)
9cde0708	129	{
30843315	130	char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL };
9cde0708	131	char *envp[] = { NULL };
30843315 VD	132	int rc;
	133
	134	/* call userspace STP and report program errors */
	135	rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	136	if (rc > 0) {
	137	if (rc & 0xff)
	138	br_debug(br, BR_STP_PROG " received signal %d\n",
	139	rc & 0x7f);
	140	else
	141	br_debug(br, BR_STP_PROG " exited with code %d\n",
	142	(rc >> 8) & 0xff);
	143	}
	144
	145	return rc;
	146	}
	147
	148	static void br_stp_start(struct net_bridge *br)
	149	{
30843315	150	int err = -ENOENT;
9cde0708	151
ff621985	152	if (net_eq(dev_net(br->dev), &init_net))
30843315 VD	153	err = br_stp_call_user(br, "start");
	154
	155	if (err && err != -ENOENT)
	156	br_err(br, "failed to start userspace STP (%d)\n", err);
be4f154d HX	157
	158	spin_lock_bh(&br->lock);
	159
	160	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	161	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
4b6c7879	162	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
be4f154d HX	163	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
be4f154d HX	164
30843315	165	if (!err) {
9cde0708	166	br->stp_enabled = BR_USER_STP;
28a16c97	167	br_debug(br, "userspace STP started\n");
9cde0708 SH	168	} else {
9cde0708 SH	169	br->stp_enabled = BR_KERNEL_STP;
28a16c97	170	br_debug(br, "using kernel STP\n");
9cde0708 SH	171
9cde0708 SH	172	/* To start timers on any ports left in blocking */
aeb07324 NA	173	if (br->dev->flags & IFF_UP)
aeb07324 NA	174	mod_timer(&br->hello_timer, jiffies + br->hello_time);
9cde0708	175	br_port_state_selection(br);
9cde0708	176	}
be4f154d HX	177
be4f154d HX	178	spin_unlock_bh(&br->lock);
9cde0708 SH	179	}
	180
	181	static void br_stp_stop(struct net_bridge *br)
	182	{
30843315	183	int err;
9cde0708 SH	184
9cde0708 SH	185	if (br->stp_enabled == BR_USER_STP) {
30843315 VD	186	err = br_stp_call_user(br, "stop");
	187	if (err)
	188	br_err(br, "failed to stop userspace STP (%d)\n", err);
9cde0708 SH	189
	190	/* To start timers on any ports left in blocking */
	191	spin_lock_bh(&br->lock);
	192	br_port_state_selection(br);
	193	spin_unlock_bh(&br->lock);
	194	}
	195
	196	br->stp_enabled = BR_NO_STP;
	197	}
	198
	199	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	200	{
	201	ASSERT_RTNL();
	202
	203	if (val) {
	204	if (br->stp_enabled == BR_NO_STP)
	205	br_stp_start(br);
	206	} else {
	207	if (br->stp_enabled != BR_NO_STP)
	208	br_stp_stop(br);
	209	}
	210	}
	211
1da177e4	212	/* called under bridge lock */
4505a3ef	213	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	214	{
9a7b6ef9	215	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	216	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	217	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	218	struct net_bridge_port *p;
	219	int wasroot;
	220
	221	wasroot = br_is_root_bridge(br);
	222
a4b816d8 TM	223	br_fdb_change_mac_address(br, addr);
a4b816d8 TM	224
1da177e4 LT	225	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	226	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	227	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	228
	229	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	230	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	231	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	232
9a7b6ef9	233	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	234	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	235	}
	236
	237	br_configuration_update(br);
	238	br_port_state_selection(br);
	239	if (br_is_root_bridge(br) && !wasroot)
	240	br_become_root_bridge(br);
	241	}
	242
9a7b6ef9	243	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	244	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	245
1da177e4 LT	246	/* called under bridge lock */
edf947f1	247	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	248	{
19bb3506 EK	249	const unsigned char *br_mac_zero =
19bb3506 EK	250	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	251	const unsigned char *addr = br_mac_zero;
	252	struct net_bridge_port *p;
	253
92c0574f	254	/* user has chosen a value so keep it */
b2748267	255	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	256	return false;
92c0574f	257
1da177e4 LT	258	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	259	if (addr == br_mac_zero \|\|
554c9a8e	260	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	261	addr = p->dev->dev_addr;
	262
	263	}
	264
9a7b6ef9	265	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	266	return false; /* no change */
	267
	268	br_stp_change_bridge_id(br, addr);
	269	return true;
1da177e4 LT	270	}
1da177e4 LT	271
2dab80a8	272	/* Acquires and releases bridge lock */
1da177e4 LT	273	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	274	{
	275	struct net_bridge_port *p;
	276	int wasroot;
	277
2dab80a8	278	spin_lock_bh(&br->lock);
1da177e4 LT	279	wasroot = br_is_root_bridge(br);
	280
	281	list_for_each_entry(p, &br->port_list, list) {
	282	if (p->state != BR_STATE_DISABLED &&
	283	br_is_designated_port(p)) {
	284	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	285	p->designated_bridge.prio[1] = newprio & 0xFF;
	286	}
	287
	288	}
	289
	290	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	291	br->bridge_id.prio[1] = newprio & 0xFF;
	292	br_configuration_update(br);
	293	br_port_state_selection(br);
	294	if (br_is_root_bridge(br) && !wasroot)
	295	br_become_root_bridge(br);
2dab80a8	296	spin_unlock_bh(&br->lock);
1da177e4 LT	297	}
	298
	299	/* called under bridge lock */
14f98f25	300	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	301	{
14f98f25	302	port_id new_port_id;
	303
	304	if (newprio > BR_MAX_PORT_PRIORITY)
	305	return -ERANGE;
1da177e4	306
14f98f25	307	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	308	if (br_is_designated_port(p))
	309	p->designated_port = new_port_id;
	310
	311	p->port_id = new_port_id;
	312	p->priority = newprio;
	313	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	314	p->port_id < p->designated_port) {
	315	br_become_designated_port(p);
	316	br_port_state_selection(p->br);
	317	}
14f98f25	318
14f98f25	319	return 0;
1da177e4 LT	320	}
	321
	322	/* called under bridge lock */
14f98f25	323	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	324	{
14f98f25	325	if (path_cost < BR_MIN_PATH_COST \|\|
	326	path_cost > BR_MAX_PATH_COST)
	327	return -ERANGE;
	328
8f3359bd	329	p->flags \|= BR_ADMIN_COST;
1da177e4 LT	330	p->path_cost = path_cost;
	331	br_configuration_update(p->br);
	332	br_port_state_selection(p->br);
14f98f25	333	return 0;
1da177e4 LT	334	}
	335
	336	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	337	{
	338	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	339	id->prio[0], id->prio[1],
	340	id->addr[0], id->addr[1], id->addr[2],
	341	id->addr[3], id->addr[4], id->addr[5]);
	342	}