[linux-2.6-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)
{
	struct switchdev_attr attr = {
		.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
		.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP | SWITCHDEV_F_DEFER,
		.u.ageing_time = p->br->ageing_time,
	};
	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 = switchdev_port_attr_set(p->dev, &attr);
	if (err && err != -EOPNOTSUPP)
		netdev_err(p->dev, "failed to set HW ageing time\n");
}

/* called under bridge lock */
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_timer(&br->gc_timer, jiffies + 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->topology_change = 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);
	del_timer_sync(&br->gc_timer);
}

/* 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_log_state(p);
	br_ifinfo_notify(RTM_NEWLINK, 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_log_state(p);
	br_ifinfo_notify(RTM_NEWLINK, p);

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

	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 void br_stp_start(struct net_bridge *br)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	char *envp[] = { NULL };
	struct net_bridge_port *p;

	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);

	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 (r == 0) {
		br->stp_enabled = BR_USER_STP;
		br_debug(br, "userspace STP started\n");
		/* Stop hello and hold timers */
		del_timer(&br->hello_timer);
		list_for_each_entry(p, &br->port_list, list)
			del_timer(&p->hold_timer);
	} else {
		br->stp_enabled = BR_KERNEL_STP;
		br_debug(br, "using kernel STP\n");

		/* To start timers on any ports left in blocking */
		br_port_state_selection(br);
	}

	spin_unlock_bh(&br->lock);
}

static void br_stp_stop(struct net_bridge *br)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	char *envp[] = { NULL };
	struct net_bridge_port *p;

	if (br->stp_enabled == BR_USER_STP) {
		r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
		br_info(br, "userspace STP stopped, return code %d\n", r);

		/* To start timers on any ports left in blocking */
		mod_timer(&br->hello_timer, jiffies + br->hello_time);
		list_for_each_entry(p, &br->port_list, list)
			mod_timer(&p->hold_timer,
				  round_jiffies(jiffies + BR_HOLD_TIME));
		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	struct switchdev_attr attr = {
	40	.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
	41	.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP \| SWITCHDEV_F_DEFER,
	42	.u.ageing_time = p->br->ageing_time,
	43	};
	44	int err;
	45
1da177e4 LT	46	p->port_id = br_make_port_id(p->priority, p->port_no);
1da177e4 LT	47	br_become_designated_port(p);
775dd692	48	br_set_state(p, BR_STATE_BLOCKING);
1da177e4 LT	49	p->topology_change_ack = 0;
1da177e4 LT	50	p->config_pending = 0;
6ac311ae ER	51
6ac311ae ER	52	err = switchdev_port_attr_set(p->dev, &attr);
bbe14f54	53	if (err && err != -EOPNOTSUPP)
6ac311ae	54	netdev_err(p->dev, "failed to set HW ageing time\n");
1da177e4 LT	55	}
	56
	57	/* called under bridge lock */
	58	void br_stp_enable_bridge(struct net_bridge *br)
	59	{
	60	struct net_bridge_port *p;
	61
	62	spin_lock_bh(&br->lock);
76b91c32 NA	63	if (br->stp_enabled == BR_KERNEL_STP)
76b91c32 NA	64	mod_timer(&br->hello_timer, jiffies + br->hello_time);
1da177e4	65	mod_timer(&br->gc_timer, jiffies + HZ/10);
9d6f229f	66
1da177e4 LT	67	br_config_bpdu_generation(br);
	68
	69	list_for_each_entry(p, &br->port_list, list) {
576eb625	70	if (netif_running(p->dev) && netif_oper_up(p->dev))
1da177e4 LT	71	br_stp_enable_port(p);
	72
	73	}
	74	spin_unlock_bh(&br->lock);
	75	}
	76
	77	/* NO locks held */
	78	void br_stp_disable_bridge(struct net_bridge *br)
	79	{
	80	struct net_bridge_port *p;
	81
78872ccb	82	spin_lock_bh(&br->lock);
1da177e4 LT	83	list_for_each_entry(p, &br->port_list, list) {
	84	if (p->state != BR_STATE_DISABLED)
	85	br_stp_disable_port(p);
	86
	87	}
	88
	89	br->topology_change = 0;
	90	br->topology_change_detected = 0;
78872ccb	91	spin_unlock_bh(&br->lock);
1da177e4 LT	92
	93	del_timer_sync(&br->hello_timer);
	94	del_timer_sync(&br->topology_change_timer);
	95	del_timer_sync(&br->tcn_timer);
	96	del_timer_sync(&br->gc_timer);
	97	}
	98
	99	/* called under bridge lock */
	100	void br_stp_enable_port(struct net_bridge_port *p)
	101	{
	102	br_init_port(p);
	103	br_port_state_selection(p->br);
28a16c97	104	br_log_state(p);
4ecb961c	105	br_ifinfo_notify(RTM_NEWLINK, p);
1da177e4 LT	106	}
	107
	108	/* called under bridge lock */
	109	void br_stp_disable_port(struct net_bridge_port *p)
	110	{
28a16c97	111	struct net_bridge *br = p->br;
1da177e4 LT	112	int wasroot;
1da177e4 LT	113
1da177e4 LT	114	wasroot = br_is_root_bridge(br);
1da177e4 LT	115	br_become_designated_port(p);
775dd692	116	br_set_state(p, BR_STATE_DISABLED);
1da177e4 LT	117	p->topology_change_ack = 0;
	118	p->config_pending = 0;
	119
5200959b	120	br_log_state(p);
4ecb961c	121	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	122
1da177e4 LT	123	del_timer(&p->message_age_timer);
	124	del_timer(&p->forward_delay_timer);
	125	del_timer(&p->hold_timer);
	126
1ea2d020	127	br_fdb_delete_by_port(br, p, 0, 0);
3fe2d7c7	128	br_multicast_disable_port(p);
1a620698	129
1da177e4 LT	130	br_configuration_update(br);
	131
	132	br_port_state_selection(br);
	133
	134	if (br_is_root_bridge(br) && !wasroot)
	135	br_become_root_bridge(br);
	136	}
	137
9cde0708 SH	138	static void br_stp_start(struct net_bridge *br)
	139	{
	140	int r;
	141	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	142	char *envp[] = { NULL };
76b91c32	143	struct net_bridge_port *p;
9cde0708	144
86313c48	145	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
be4f154d HX	146
	147	spin_lock_bh(&br->lock);
	148
	149	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	150	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
4b6c7879	151	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
be4f154d HX	152	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
be4f154d HX	153
9cde0708 SH	154	if (r == 0) {
9cde0708 SH	155	br->stp_enabled = BR_USER_STP;
28a16c97	156	br_debug(br, "userspace STP started\n");
76b91c32 NA	157	/* Stop hello and hold timers */
	158	del_timer(&br->hello_timer);
	159	list_for_each_entry(p, &br->port_list, list)
	160	del_timer(&p->hold_timer);
9cde0708 SH	161	} else {
9cde0708 SH	162	br->stp_enabled = BR_KERNEL_STP;
28a16c97	163	br_debug(br, "using kernel STP\n");
9cde0708 SH	164
9cde0708 SH	165	/* To start timers on any ports left in blocking */
9cde0708	166	br_port_state_selection(br);
9cde0708	167	}
be4f154d HX	168
be4f154d HX	169	spin_unlock_bh(&br->lock);
9cde0708 SH	170	}
	171
	172	static void br_stp_stop(struct net_bridge *br)
	173	{
	174	int r;
	175	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	176	char *envp[] = { NULL };
76b91c32	177	struct net_bridge_port *p;
9cde0708 SH	178
9cde0708 SH	179	if (br->stp_enabled == BR_USER_STP) {
1a9180a2	180	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
28a16c97	181	br_info(br, "userspace STP stopped, return code %d\n", r);
9cde0708 SH	182
9cde0708 SH	183	/* To start timers on any ports left in blocking */
76b91c32 NA	184	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	185	list_for_each_entry(p, &br->port_list, list)
	186	mod_timer(&p->hold_timer,
	187	round_jiffies(jiffies + BR_HOLD_TIME));
9cde0708 SH	188	spin_lock_bh(&br->lock);
	189	br_port_state_selection(br);
	190	spin_unlock_bh(&br->lock);
	191	}
	192
	193	br->stp_enabled = BR_NO_STP;
	194	}
	195
	196	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	197	{
	198	ASSERT_RTNL();
	199
	200	if (val) {
	201	if (br->stp_enabled == BR_NO_STP)
	202	br_stp_start(br);
	203	} else {
	204	if (br->stp_enabled != BR_NO_STP)
	205	br_stp_stop(br);
	206	}
	207	}
	208
1da177e4	209	/* called under bridge lock */
4505a3ef	210	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	211	{
9a7b6ef9	212	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	213	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	214	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	215	struct net_bridge_port *p;
	216	int wasroot;
	217
	218	wasroot = br_is_root_bridge(br);
	219
a4b816d8 TM	220	br_fdb_change_mac_address(br, addr);
a4b816d8 TM	221
1da177e4 LT	222	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	223	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	224	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	225
	226	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	227	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	228	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	229
9a7b6ef9	230	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	231	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	232	}
	233
	234	br_configuration_update(br);
	235	br_port_state_selection(br);
	236	if (br_is_root_bridge(br) && !wasroot)
	237	br_become_root_bridge(br);
	238	}
	239
9a7b6ef9	240	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	241	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	242
1da177e4 LT	243	/* called under bridge lock */
edf947f1	244	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	245	{
19bb3506 EK	246	const unsigned char *br_mac_zero =
19bb3506 EK	247	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	248	const unsigned char *addr = br_mac_zero;
	249	struct net_bridge_port *p;
	250
92c0574f	251	/* user has chosen a value so keep it */
b2748267	252	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	253	return false;
92c0574f	254
1da177e4 LT	255	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	256	if (addr == br_mac_zero \|\|
554c9a8e	257	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	258	addr = p->dev->dev_addr;
	259
	260	}
	261
9a7b6ef9	262	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	263	return false; /* no change */
	264
	265	br_stp_change_bridge_id(br, addr);
	266	return true;
1da177e4 LT	267	}
1da177e4 LT	268
2dab80a8	269	/* Acquires and releases bridge lock */
1da177e4 LT	270	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	271	{
	272	struct net_bridge_port *p;
	273	int wasroot;
	274
2dab80a8	275	spin_lock_bh(&br->lock);
1da177e4 LT	276	wasroot = br_is_root_bridge(br);
	277
	278	list_for_each_entry(p, &br->port_list, list) {
	279	if (p->state != BR_STATE_DISABLED &&
	280	br_is_designated_port(p)) {
	281	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	282	p->designated_bridge.prio[1] = newprio & 0xFF;
	283	}
	284
	285	}
	286
	287	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	288	br->bridge_id.prio[1] = newprio & 0xFF;
	289	br_configuration_update(br);
	290	br_port_state_selection(br);
	291	if (br_is_root_bridge(br) && !wasroot)
	292	br_become_root_bridge(br);
2dab80a8	293	spin_unlock_bh(&br->lock);
1da177e4 LT	294	}
	295
	296	/* called under bridge lock */
14f98f25	297	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	298	{
14f98f25	299	port_id new_port_id;
	300
	301	if (newprio > BR_MAX_PORT_PRIORITY)
	302	return -ERANGE;
1da177e4	303
14f98f25	304	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	305	if (br_is_designated_port(p))
	306	p->designated_port = new_port_id;
	307
	308	p->port_id = new_port_id;
	309	p->priority = newprio;
	310	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	311	p->port_id < p->designated_port) {
	312	br_become_designated_port(p);
	313	br_port_state_selection(p->br);
	314	}
14f98f25	315
14f98f25	316	return 0;
1da177e4 LT	317	}
	318
	319	/* called under bridge lock */
14f98f25	320	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	321	{
14f98f25	322	if (path_cost < BR_MIN_PATH_COST \|\|
	323	path_cost > BR_MAX_PATH_COST)
	324	return -ERANGE;
	325
8f3359bd	326	p->flags \|= BR_ADMIN_COST;
1da177e4 LT	327	p->path_cost = path_cost;
	328	br_configuration_update(p->br);
	329	br_port_state_selection(p->br);
14f98f25	330	return 0;
1da177e4 LT	331	}
	332
	333	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	334	{
	335	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	336	id->prio[0], id->prio[1],
	337	id->addr[0], id->addr[1], id->addr[2],
	338	id->addr[3], id->addr[4], id->addr[5]);
	339	}