[mirror_ubuntu-artful-kernel.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 = {
		.orig_dev = p->dev,
		.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
		.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP | SWITCHDEV_F_DEFER,
		.u.ageing_time = jiffies_to_clock_t(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");
}

/* 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_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_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_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 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)
{
	struct net_bridge_port *p;
	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");

		/* 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)
{
	struct net_bridge_port *p;
	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 */
		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	39	struct switchdev_attr attr = {
6ff64f6f	40	.orig_dev = p->dev,
6ac311ae ER	41	.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
6ac311ae ER	42	.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP \| SWITCHDEV_F_DEFER,
ef9cdd0f	43	.u.ageing_time = jiffies_to_clock_t(p->br->ageing_time),
6ac311ae ER	44	};
	45	int err;
	46
1da177e4 LT	47	p->port_id = br_make_port_id(p->priority, p->port_no);
1da177e4 LT	48	br_become_designated_port(p);
775dd692	49	br_set_state(p, BR_STATE_BLOCKING);
1da177e4 LT	50	p->topology_change_ack = 0;
1da177e4 LT	51	p->config_pending = 0;
6ac311ae ER	52
6ac311ae ER	53	err = switchdev_port_attr_set(p->dev, &attr);
bbe14f54	54	if (err && err != -EOPNOTSUPP)
6ac311ae	55	netdev_err(p->dev, "failed to set HW ageing time\n");
1da177e4 LT	56	}
1da177e4 LT	57
dba479f3	58	/* NO locks held */
1da177e4 LT	59	void br_stp_enable_bridge(struct net_bridge *br)
	60	{
	61	struct net_bridge_port *p;
	62
	63	spin_lock_bh(&br->lock);
76b91c32 NA	64	if (br->stp_enabled == BR_KERNEL_STP)
76b91c32 NA	65	mod_timer(&br->hello_timer, jiffies + br->hello_time);
1da177e4	66	mod_timer(&br->gc_timer, jiffies + HZ/10);
9d6f229f	67
1da177e4 LT	68	br_config_bpdu_generation(br);
	69
	70	list_for_each_entry(p, &br->port_list, list) {
576eb625	71	if (netif_running(p->dev) && netif_oper_up(p->dev))
1da177e4 LT	72	br_stp_enable_port(p);
	73
	74	}
	75	spin_unlock_bh(&br->lock);
	76	}
	77
	78	/* NO locks held */
	79	void br_stp_disable_bridge(struct net_bridge *br)
	80	{
	81	struct net_bridge_port *p;
	82
78872ccb	83	spin_lock_bh(&br->lock);
1da177e4 LT	84	list_for_each_entry(p, &br->port_list, list) {
	85	if (p->state != BR_STATE_DISABLED)
	86	br_stp_disable_port(p);
	87
	88	}
	89
	90	br->topology_change = 0;
	91	br->topology_change_detected = 0;
78872ccb	92	spin_unlock_bh(&br->lock);
1da177e4 LT	93
	94	del_timer_sync(&br->hello_timer);
	95	del_timer_sync(&br->topology_change_timer);
	96	del_timer_sync(&br->tcn_timer);
	97	del_timer_sync(&br->gc_timer);
	98	}
	99
	100	/* called under bridge lock */
	101	void br_stp_enable_port(struct net_bridge_port *p)
	102	{
	103	br_init_port(p);
	104	br_port_state_selection(p->br);
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
4ecb961c	120	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	121
1da177e4 LT	122	del_timer(&p->message_age_timer);
	123	del_timer(&p->forward_delay_timer);
	124	del_timer(&p->hold_timer);
	125
1ea2d020	126	br_fdb_delete_by_port(br, p, 0, 0);
3fe2d7c7	127	br_multicast_disable_port(p);
1a620698	128
1da177e4 LT	129	br_configuration_update(br);
	130
	131	br_port_state_selection(br);
	132
	133	if (br_is_root_bridge(br) && !wasroot)
	134	br_become_root_bridge(br);
	135	}
	136
30843315	137	static int br_stp_call_user(struct net_bridge br, char arg)
9cde0708	138	{
30843315	139	char *argv[] = { BR_STP_PROG, br->dev->name, arg, NULL };
9cde0708	140	char *envp[] = { NULL };
30843315 VD	141	int rc;
	142
	143	/* call userspace STP and report program errors */
	144	rc = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	145	if (rc > 0) {
	146	if (rc & 0xff)
	147	br_debug(br, BR_STP_PROG " received signal %d\n",
	148	rc & 0x7f);
	149	else
	150	br_debug(br, BR_STP_PROG " exited with code %d\n",
	151	(rc >> 8) & 0xff);
	152	}
	153
	154	return rc;
	155	}
	156
	157	static void br_stp_start(struct net_bridge *br)
	158	{
76b91c32	159	struct net_bridge_port *p;
30843315	160	int err = -ENOENT;
9cde0708	161
ff621985	162	if (net_eq(dev_net(br->dev), &init_net))
30843315 VD	163	err = br_stp_call_user(br, "start");
	164
	165	if (err && err != -ENOENT)
	166	br_err(br, "failed to start userspace STP (%d)\n", err);
be4f154d HX	167
	168	spin_lock_bh(&br->lock);
	169
	170	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	171	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
4b6c7879	172	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
be4f154d HX	173	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
be4f154d HX	174
30843315	175	if (!err) {
9cde0708	176	br->stp_enabled = BR_USER_STP;
28a16c97	177	br_debug(br, "userspace STP started\n");
30843315	178
76b91c32 NA	179	/* Stop hello and hold timers */
	180	del_timer(&br->hello_timer);
	181	list_for_each_entry(p, &br->port_list, list)
	182	del_timer(&p->hold_timer);
9cde0708 SH	183	} else {
9cde0708 SH	184	br->stp_enabled = BR_KERNEL_STP;
28a16c97	185	br_debug(br, "using kernel STP\n");
9cde0708 SH	186
9cde0708 SH	187	/* To start timers on any ports left in blocking */
9cde0708	188	br_port_state_selection(br);
9cde0708	189	}
be4f154d HX	190
be4f154d HX	191	spin_unlock_bh(&br->lock);
9cde0708 SH	192	}
	193
	194	static void br_stp_stop(struct net_bridge *br)
	195	{
76b91c32	196	struct net_bridge_port *p;
30843315	197	int err;
9cde0708 SH	198
9cde0708 SH	199	if (br->stp_enabled == BR_USER_STP) {
30843315 VD	200	err = br_stp_call_user(br, "stop");
	201	if (err)
	202	br_err(br, "failed to stop userspace STP (%d)\n", err);
9cde0708 SH	203
9cde0708 SH	204	/* To start timers on any ports left in blocking */
76b91c32 NA	205	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	206	list_for_each_entry(p, &br->port_list, list)
	207	mod_timer(&p->hold_timer,
	208	round_jiffies(jiffies + BR_HOLD_TIME));
9cde0708 SH	209	spin_lock_bh(&br->lock);
	210	br_port_state_selection(br);
	211	spin_unlock_bh(&br->lock);
	212	}
	213
	214	br->stp_enabled = BR_NO_STP;
	215	}
	216
	217	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	218	{
	219	ASSERT_RTNL();
	220
	221	if (val) {
	222	if (br->stp_enabled == BR_NO_STP)
	223	br_stp_start(br);
	224	} else {
	225	if (br->stp_enabled != BR_NO_STP)
	226	br_stp_stop(br);
	227	}
	228	}
	229
1da177e4	230	/* called under bridge lock */
4505a3ef	231	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	232	{
9a7b6ef9	233	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	234	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	235	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	236	struct net_bridge_port *p;
	237	int wasroot;
	238
	239	wasroot = br_is_root_bridge(br);
	240
a4b816d8 TM	241	br_fdb_change_mac_address(br, addr);
a4b816d8 TM	242
1da177e4 LT	243	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	244	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	245	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	246
	247	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	248	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	249	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	250
9a7b6ef9	251	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	252	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	253	}
	254
	255	br_configuration_update(br);
	256	br_port_state_selection(br);
	257	if (br_is_root_bridge(br) && !wasroot)
	258	br_become_root_bridge(br);
	259	}
	260
9a7b6ef9	261	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	262	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	263
1da177e4 LT	264	/* called under bridge lock */
edf947f1	265	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	266	{
19bb3506 EK	267	const unsigned char *br_mac_zero =
19bb3506 EK	268	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	269	const unsigned char *addr = br_mac_zero;
	270	struct net_bridge_port *p;
	271
92c0574f	272	/* user has chosen a value so keep it */
b2748267	273	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	274	return false;
92c0574f	275
1da177e4 LT	276	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	277	if (addr == br_mac_zero \|\|
554c9a8e	278	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	279	addr = p->dev->dev_addr;
	280
	281	}
	282
9a7b6ef9	283	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	284	return false; /* no change */
	285
	286	br_stp_change_bridge_id(br, addr);
	287	return true;
1da177e4 LT	288	}
1da177e4 LT	289
2dab80a8	290	/* Acquires and releases bridge lock */
1da177e4 LT	291	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	292	{
	293	struct net_bridge_port *p;
	294	int wasroot;
	295
2dab80a8	296	spin_lock_bh(&br->lock);
1da177e4 LT	297	wasroot = br_is_root_bridge(br);
	298
	299	list_for_each_entry(p, &br->port_list, list) {
	300	if (p->state != BR_STATE_DISABLED &&
	301	br_is_designated_port(p)) {
	302	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	303	p->designated_bridge.prio[1] = newprio & 0xFF;
	304	}
	305
	306	}
	307
	308	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	309	br->bridge_id.prio[1] = newprio & 0xFF;
	310	br_configuration_update(br);
	311	br_port_state_selection(br);
	312	if (br_is_root_bridge(br) && !wasroot)
	313	br_become_root_bridge(br);
2dab80a8	314	spin_unlock_bh(&br->lock);
1da177e4 LT	315	}
	316
	317	/* called under bridge lock */
14f98f25	318	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	319	{
14f98f25	320	port_id new_port_id;
	321
	322	if (newprio > BR_MAX_PORT_PRIORITY)
	323	return -ERANGE;
1da177e4	324
14f98f25	325	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	326	if (br_is_designated_port(p))
	327	p->designated_port = new_port_id;
	328
	329	p->port_id = new_port_id;
	330	p->priority = newprio;
	331	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	332	p->port_id < p->designated_port) {
	333	br_become_designated_port(p);
	334	br_port_state_selection(p->br);
	335	}
14f98f25	336
14f98f25	337	return 0;
1da177e4 LT	338	}
	339
	340	/* called under bridge lock */
14f98f25	341	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	342	{
14f98f25	343	if (path_cost < BR_MIN_PATH_COST \|\|
	344	path_cost > BR_MAX_PATH_COST)
	345	return -ERANGE;
	346
8f3359bd	347	p->flags \|= BR_ADMIN_COST;
1da177e4 LT	348	p->path_cost = path_cost;
	349	br_configuration_update(p->br);
	350	br_port_state_selection(p->br);
14f98f25	351	return 0;
1da177e4 LT	352	}
	353
	354	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	355	{
	356	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	357	id->prio[0], id->prio[1],
	358	id->addr[0], id->addr[1], id->addr[2],
	359	id->addr[3], id->addr[4], id->addr[5]);
	360	}