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

/*
 *	Spanning tree protocol; interface code
 *	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/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
1da177e4 LT	1	/*
	2	* Spanning tree protocol; interface code
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
1da177e4 LT	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>
79bb1ee4	15	#include <linux/kmod.h>
6ede2463	16	#include <linux/etherdevice.h>
11dc1f36	17	#include <linux/rtnetlink.h>
6ac311ae	18	#include <net/switchdev.h>
1da177e4 LT	19
	20	#include "br_private.h"
	21	#include "br_private_stp.h"
	22
	23
	24	/* Port id is composed of priority and port number.
14f98f25	25	* NB: some bits of priority are dropped to
1da177e4 LT	26	* make room for more ports.
	27	*/
	28	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	29	{
9d6f229f	30	return ((u16)priority << BR_PORT_BITS)
1da177e4 LT	31	\| (port_no & ((1<<BR_PORT_BITS)-1));
	32	}
	33
14f98f25	34	#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
14f98f25	35
1da177e4 LT	36	/* called under bridge lock */
	37	void br_init_port(struct net_bridge_port *p)
	38	{
6ac311ae ER	39	int err;
6ac311ae ER	40
1da177e4 LT	41	p->port_id = br_make_port_id(p->priority, p->port_no);
1da177e4 LT	42	br_become_designated_port(p);
775dd692	43	br_set_state(p, BR_STATE_BLOCKING);
1da177e4 LT	44	p->topology_change_ack = 0;
1da177e4 LT	45	p->config_pending = 0;
6ac311ae	46
82dd4332 VD	47	err = __set_ageing_time(p->dev, p->br->ageing_time);
	48	if (err)
	49	netdev_err(p->dev, "failed to offload ageing time\n");
1da177e4 LT	50	}
1da177e4 LT	51
dba479f3	52	/* NO locks held */
1da177e4 LT	53	void br_stp_enable_bridge(struct net_bridge *br)
	54	{
	55	struct net_bridge_port *p;
	56
	57	spin_lock_bh(&br->lock);
76b91c32 NA	58	if (br->stp_enabled == BR_KERNEL_STP)
76b91c32 NA	59	mod_timer(&br->hello_timer, jiffies + br->hello_time);
f7cdee8a	60	mod_delayed_work(system_long_wq, &br->gc_work, HZ / 10);
9d6f229f	61
1da177e4 LT	62	br_config_bpdu_generation(br);
	63
	64	list_for_each_entry(p, &br->port_list, list) {
576eb625	65	if (netif_running(p->dev) && netif_oper_up(p->dev))
1da177e4 LT	66	br_stp_enable_port(p);
	67
	68	}
	69	spin_unlock_bh(&br->lock);
	70	}
	71
	72	/* NO locks held */
	73	void br_stp_disable_bridge(struct net_bridge *br)
	74	{
	75	struct net_bridge_port *p;
	76
78872ccb	77	spin_lock_bh(&br->lock);
1da177e4 LT	78	list_for_each_entry(p, &br->port_list, list) {
	79	if (p->state != BR_STATE_DISABLED)
	80	br_stp_disable_port(p);
	81
	82	}
	83
8384b5f5	84	__br_set_topology_change(br, 0);
1da177e4	85	br->topology_change_detected = 0;
78872ccb	86	spin_unlock_bh(&br->lock);
1da177e4 LT	87
	88	del_timer_sync(&br->hello_timer);
	89	del_timer_sync(&br->topology_change_timer);
	90	del_timer_sync(&br->tcn_timer);
f7cdee8a	91	cancel_delayed_work_sync(&br->gc_work);
1da177e4 LT	92	}
	93
	94	/* called under bridge lock */
	95	void br_stp_enable_port(struct net_bridge_port *p)
	96	{
	97	br_init_port(p);
	98	br_port_state_selection(p->br);
92899063	99	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
1da177e4 LT	100	}
	101
	102	/* called under bridge lock */
	103	void br_stp_disable_port(struct net_bridge_port *p)
	104	{
28a16c97	105	struct net_bridge *br = p->br;
1da177e4 LT	106	int wasroot;
1da177e4 LT	107
1da177e4 LT	108	wasroot = br_is_root_bridge(br);
1da177e4 LT	109	br_become_designated_port(p);
775dd692	110	br_set_state(p, BR_STATE_DISABLED);
1da177e4 LT	111	p->topology_change_ack = 0;
	112	p->config_pending = 0;
	113
92899063	114	br_ifinfo_notify(RTM_NEWLINK, NULL, p);
4ecb961c	115
1da177e4 LT	116	del_timer(&p->message_age_timer);
	117	del_timer(&p->forward_delay_timer);
	118	del_timer(&p->hold_timer);
	119
8dc35020 NA	120	if (!rcu_access_pointer(p->backup_port))
8dc35020 NA	121	br_fdb_delete_by_port(br, p, 0, 0);
3fe2d7c7	122	br_multicast_disable_port(p);
1a620698	123
1da177e4 LT	124	br_configuration_update(br);
	125
	126	br_port_state_selection(br);
	127
	128	if (br_is_root_bridge(br) && !wasroot)
	129	br_become_root_bridge(br);
	130	}
	131
30843315	132	static int br_stp_call_user(struct net_bridge br, char arg)
9cde0708	133	{
30843315	134	char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL };
9cde0708	135	char *envp[] = { NULL };
30843315 VD	136	int rc;
	137
	138	/* call userspace STP and report program errors */
	139	rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	140	if (rc > 0) {
	141	if (rc & 0xff)
	142	br_debug(br, BR_STP_PROG " received signal %d\n",
	143	rc & 0x7f);
	144	else
	145	br_debug(br, BR_STP_PROG " exited with code %d\n",
	146	(rc >> 8) & 0xff);
	147	}
	148
	149	return rc;
	150	}
	151
	152	static void br_stp_start(struct net_bridge *br)
	153	{
30843315	154	int err = -ENOENT;
9cde0708	155
ff621985	156	if (net_eq(dev_net(br->dev), &init_net))
30843315 VD	157	err = br_stp_call_user(br, "start");
	158
	159	if (err && err != -ENOENT)
	160	br_err(br, "failed to start userspace STP (%d)\n", err);
be4f154d HX	161
	162	spin_lock_bh(&br->lock);
	163
	164	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	165	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
4b6c7879	166	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
be4f154d HX	167	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
be4f154d HX	168
30843315	169	if (!err) {
9cde0708	170	br->stp_enabled = BR_USER_STP;
28a16c97	171	br_debug(br, "userspace STP started\n");
9cde0708 SH	172	} else {
9cde0708 SH	173	br->stp_enabled = BR_KERNEL_STP;
28a16c97	174	br_debug(br, "using kernel STP\n");
9cde0708 SH	175
9cde0708 SH	176	/* To start timers on any ports left in blocking */
aeb07324 NA	177	if (br->dev->flags & IFF_UP)
aeb07324 NA	178	mod_timer(&br->hello_timer, jiffies + br->hello_time);
9cde0708	179	br_port_state_selection(br);
9cde0708	180	}
be4f154d HX	181
be4f154d HX	182	spin_unlock_bh(&br->lock);
9cde0708 SH	183	}
	184
	185	static void br_stp_stop(struct net_bridge *br)
	186	{
30843315	187	int err;
9cde0708 SH	188
9cde0708 SH	189	if (br->stp_enabled == BR_USER_STP) {
30843315 VD	190	err = br_stp_call_user(br, "stop");
	191	if (err)
	192	br_err(br, "failed to stop userspace STP (%d)\n", err);
9cde0708 SH	193
	194	/* To start timers on any ports left in blocking */
	195	spin_lock_bh(&br->lock);
	196	br_port_state_selection(br);
	197	spin_unlock_bh(&br->lock);
	198	}
	199
	200	br->stp_enabled = BR_NO_STP;
	201	}
	202
	203	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	204	{
	205	ASSERT_RTNL();
	206
	207	if (val) {
	208	if (br->stp_enabled == BR_NO_STP)
	209	br_stp_start(br);
	210	} else {
	211	if (br->stp_enabled != BR_NO_STP)
	212	br_stp_stop(br);
	213	}
	214	}
	215
1da177e4	216	/* called under bridge lock */
4505a3ef	217	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	218	{
9a7b6ef9	219	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	220	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	221	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	222	struct net_bridge_port *p;
	223	int wasroot;
	224
	225	wasroot = br_is_root_bridge(br);
	226
a4b816d8 TM	227	br_fdb_change_mac_address(br, addr);
a4b816d8 TM	228
1da177e4 LT	229	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	230	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	231	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	232
	233	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	234	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	235	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	236
9a7b6ef9	237	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	238	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	239	}
	240
	241	br_configuration_update(br);
	242	br_port_state_selection(br);
	243	if (br_is_root_bridge(br) && !wasroot)
	244	br_become_root_bridge(br);
	245	}
	246
9a7b6ef9	247	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	248	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	249
1da177e4 LT	250	/* called under bridge lock */
edf947f1	251	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	252	{
19bb3506 EK	253	const unsigned char *br_mac_zero =
19bb3506 EK	254	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	255	const unsigned char *addr = br_mac_zero;
	256	struct net_bridge_port *p;
	257
92c0574f	258	/* user has chosen a value so keep it */
b2748267	259	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	260	return false;
92c0574f	261
1da177e4 LT	262	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	263	if (addr == br_mac_zero \|\|
554c9a8e	264	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	265	addr = p->dev->dev_addr;
	266
	267	}
	268
9a7b6ef9	269	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	270	return false; /* no change */
	271
	272	br_stp_change_bridge_id(br, addr);
	273	return true;
1da177e4 LT	274	}
1da177e4 LT	275
2dab80a8	276	/* Acquires and releases bridge lock */
1da177e4 LT	277	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	278	{
	279	struct net_bridge_port *p;
	280	int wasroot;
	281
2dab80a8	282	spin_lock_bh(&br->lock);
1da177e4 LT	283	wasroot = br_is_root_bridge(br);
	284
	285	list_for_each_entry(p, &br->port_list, list) {
	286	if (p->state != BR_STATE_DISABLED &&
	287	br_is_designated_port(p)) {
	288	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	289	p->designated_bridge.prio[1] = newprio & 0xFF;
	290	}
	291
	292	}
	293
	294	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	295	br->bridge_id.prio[1] = newprio & 0xFF;
	296	br_configuration_update(br);
	297	br_port_state_selection(br);
	298	if (br_is_root_bridge(br) && !wasroot)
	299	br_become_root_bridge(br);
2dab80a8	300	spin_unlock_bh(&br->lock);
1da177e4 LT	301	}
	302
	303	/* called under bridge lock */
14f98f25	304	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	305	{
14f98f25	306	port_id new_port_id;
	307
	308	if (newprio > BR_MAX_PORT_PRIORITY)
	309	return -ERANGE;
1da177e4	310
14f98f25	311	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	312	if (br_is_designated_port(p))
	313	p->designated_port = new_port_id;
	314
	315	p->port_id = new_port_id;
	316	p->priority = newprio;
	317	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	318	p->port_id < p->designated_port) {
	319	br_become_designated_port(p);
	320	br_port_state_selection(p->br);
	321	}
14f98f25	322
14f98f25	323	return 0;
1da177e4 LT	324	}
	325
	326	/* called under bridge lock */
14f98f25	327	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	328	{
14f98f25	329	if (path_cost < BR_MIN_PATH_COST \|\|
	330	path_cost > BR_MAX_PATH_COST)
	331	return -ERANGE;
	332
8f3359bd	333	p->flags \|= BR_ADMIN_COST;
1da177e4 LT	334	p->path_cost = path_cost;
	335	br_configuration_update(p->br);
	336	br_port_state_selection(p->br);
14f98f25	337	return 0;
1da177e4 LT	338	}
	339
	340	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	341	{
	342	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	343	id->prio[0], id->prio[1],
	344	id->addr[0], id->addr[1], id->addr[2],
	345	id->addr[3], id->addr[4], id->addr[5]);
	346	}