[deliverable/linux.git] / net / bridge / br_stp.c

/*
 *	Spanning tree protocol; generic parts
 *	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/rculist.h>
#include <net/switchdev.h>

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

/* since time values in bpdu are in jiffies and then scaled (1/256)
 * before sending, make sure that is at least one STP tick.
 */
#define MESSAGE_AGE_INCR	((HZ / 256) + 1)

static const char *const br_port_state_names[] = {
	[BR_STATE_DISABLED] = "disabled",
	[BR_STATE_LISTENING] = "listening",
	[BR_STATE_LEARNING] = "learning",
	[BR_STATE_FORWARDING] = "forwarding",
	[BR_STATE_BLOCKING] = "blocking",
};

void br_set_state(struct net_bridge_port *p, unsigned int state)
{
	struct switchdev_attr attr = {
		.orig_dev = p->dev,
		.id = SWITCHDEV_ATTR_ID_PORT_STP_STATE,
		.flags = SWITCHDEV_F_DEFER,
		.u.stp_state = state,
	};
	int err;

	p->state = state;
	err = switchdev_port_attr_set(p->dev, &attr);
	if (err && err != -EOPNOTSUPP)
		br_warn(p->br, "error setting offload STP state on port %u(%s)\n",
				(unsigned int) p->port_no, p->dev->name);
	else
		br_info(p->br, "port %u(%s) entered %s state\n",
				(unsigned int) p->port_no, p->dev->name,
				br_port_state_names[p->state]);
}

/* called under bridge lock */
struct net_bridge_port *br_get_port(struct net_bridge *br, u16 port_no)
{
	struct net_bridge_port *p;

	list_for_each_entry_rcu(p, &br->port_list, list) {
		if (p->port_no == port_no)
			return p;
	}

	return NULL;
}

/* called under bridge lock */
static int br_should_become_root_port(const struct net_bridge_port *p,
				      u16 root_port)
{
	struct net_bridge *br;
	struct net_bridge_port *rp;
	int t;

	br = p->br;
	if (p->state == BR_STATE_DISABLED ||
	    br_is_designated_port(p))
		return 0;

	if (memcmp(&br->bridge_id, &p->designated_root, 8) <= 0)
		return 0;

	if (!root_port)
		return 1;

	rp = br_get_port(br, root_port);

	t = memcmp(&p->designated_root, &rp->designated_root, 8);
	if (t < 0)
		return 1;
	else if (t > 0)
		return 0;

	if (p->designated_cost + p->path_cost <
	    rp->designated_cost + rp->path_cost)
		return 1;
	else if (p->designated_cost + p->path_cost >
		 rp->designated_cost + rp->path_cost)
		return 0;

	t = memcmp(&p->designated_bridge, &rp->designated_bridge, 8);
	if (t < 0)
		return 1;
	else if (t > 0)
		return 0;

	if (p->designated_port < rp->designated_port)
		return 1;
	else if (p->designated_port > rp->designated_port)
		return 0;

	if (p->port_id < rp->port_id)
		return 1;

	return 0;
}

static void br_root_port_block(const struct net_bridge *br,
			       struct net_bridge_port *p)
{

	br_notice(br, "port %u(%s) tried to become root port (blocked)",
		  (unsigned int) p->port_no, p->dev->name);

	br_set_state(p, BR_STATE_LISTENING);
	br_ifinfo_notify(RTM_NEWLINK, p);

	if (br->forward_delay > 0)
		mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
}

/* called under bridge lock */
static void br_root_selection(struct net_bridge *br)
{
	struct net_bridge_port *p;
	u16 root_port = 0;

	list_for_each_entry(p, &br->port_list, list) {
		if (!br_should_become_root_port(p, root_port))
			continue;

		if (p->flags & BR_ROOT_BLOCK)
			br_root_port_block(br, p);
		else
			root_port = p->port_no;
	}

	br->root_port = root_port;

	if (!root_port) {
		br->designated_root = br->bridge_id;
		br->root_path_cost = 0;
	} else {
		p = br_get_port(br, root_port);
		br->designated_root = p->designated_root;
		br->root_path_cost = p->designated_cost + p->path_cost;
	}
}

/* called under bridge lock */
void br_become_root_bridge(struct net_bridge *br)
{
	br->max_age = br->bridge_max_age;
	br->hello_time = br->bridge_hello_time;
	br->forward_delay = br->bridge_forward_delay;
	br_topology_change_detection(br);
	del_timer(&br->tcn_timer);

	if (br->dev->flags & IFF_UP) {
		br_config_bpdu_generation(br);
		mod_timer(&br->hello_timer, jiffies + br->hello_time);
	}
}

/* called under bridge lock */
void br_transmit_config(struct net_bridge_port *p)
{
	struct br_config_bpdu bpdu;
	struct net_bridge *br;

	if (timer_pending(&p->hold_timer)) {
		p->config_pending = 1;
		return;
	}

	br = p->br;

	bpdu.topology_change = br->topology_change;
	bpdu.topology_change_ack = p->topology_change_ack;
	bpdu.root = br->designated_root;
	bpdu.root_path_cost = br->root_path_cost;
	bpdu.bridge_id = br->bridge_id;
	bpdu.port_id = p->port_id;
	if (br_is_root_bridge(br))
		bpdu.message_age = 0;
	else {
		struct net_bridge_port *root
			= br_get_port(br, br->root_port);
		bpdu.message_age = (jiffies - root->designated_age)
			+ MESSAGE_AGE_INCR;
	}
	bpdu.max_age = br->max_age;
	bpdu.hello_time = br->hello_time;
	bpdu.forward_delay = br->forward_delay;

	if (bpdu.message_age < br->max_age) {
		br_send_config_bpdu(p, &bpdu);
		p->topology_change_ack = 0;
		p->config_pending = 0;
		if (p->br->stp_enabled == BR_KERNEL_STP)
			mod_timer(&p->hold_timer,
				  round_jiffies(jiffies + BR_HOLD_TIME));
	}
}

/* called under bridge lock */
static void br_record_config_information(struct net_bridge_port *p,
					 const struct br_config_bpdu *bpdu)
{
	p->designated_root = bpdu->root;
	p->designated_cost = bpdu->root_path_cost;
	p->designated_bridge = bpdu->bridge_id;
	p->designated_port = bpdu->port_id;
	p->designated_age = jiffies - bpdu->message_age;

	mod_timer(&p->message_age_timer, jiffies
		  + (bpdu->max_age - bpdu->message_age));
}

/* called under bridge lock */
static void br_record_config_timeout_values(struct net_bridge *br,
					    const struct br_config_bpdu *bpdu)
{
	br->max_age = bpdu->max_age;
	br->hello_time = bpdu->hello_time;
	br->forward_delay = bpdu->forward_delay;
	br->topology_change = bpdu->topology_change;
}

/* called under bridge lock */
void br_transmit_tcn(struct net_bridge *br)
{
	struct net_bridge_port *p;

	p = br_get_port(br, br->root_port);
	if (p)
		br_send_tcn_bpdu(p);
	else
		br_notice(br, "root port %u not found for topology notice\n",
			  br->root_port);
}

/* called under bridge lock */
static int br_should_become_designated_port(const struct net_bridge_port *p)
{
	struct net_bridge *br;
	int t;

	br = p->br;
	if (br_is_designated_port(p))
		return 1;

	if (memcmp(&p->designated_root, &br->designated_root, 8))
		return 1;

	if (br->root_path_cost < p->designated_cost)
		return 1;
	else if (br->root_path_cost > p->designated_cost)
		return 0;

	t = memcmp(&br->bridge_id, &p->designated_bridge, 8);
	if (t < 0)
		return 1;
	else if (t > 0)
		return 0;

	if (p->port_id < p->designated_port)
		return 1;

	return 0;
}

/* called under bridge lock */
static void br_designated_port_selection(struct net_bridge *br)
{
	struct net_bridge_port *p;

	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED &&
		    br_should_become_designated_port(p))
			br_become_designated_port(p);

	}
}

/* called under bridge lock */
static int br_supersedes_port_info(const struct net_bridge_port *p,
				   const struct br_config_bpdu *bpdu)
{
	int t;

	t = memcmp(&bpdu->root, &p->designated_root, 8);
	if (t < 0)
		return 1;
	else if (t > 0)
		return 0;

	if (bpdu->root_path_cost < p->designated_cost)
		return 1;
	else if (bpdu->root_path_cost > p->designated_cost)
		return 0;

	t = memcmp(&bpdu->bridge_id, &p->designated_bridge, 8);
	if (t < 0)
		return 1;
	else if (t > 0)
		return 0;

	if (memcmp(&bpdu->bridge_id, &p->br->bridge_id, 8))
		return 1;

	if (bpdu->port_id <= p->designated_port)
		return 1;

	return 0;
}

/* called under bridge lock */
static void br_topology_change_acknowledged(struct net_bridge *br)
{
	br->topology_change_detected = 0;
	del_timer(&br->tcn_timer);
}

/* called under bridge lock */
void br_topology_change_detection(struct net_bridge *br)
{
	int isroot = br_is_root_bridge(br);

	if (br->stp_enabled != BR_KERNEL_STP)
		return;

	br_info(br, "topology change detected, %s\n",
		isroot ? "propagating" : "sending tcn bpdu");

	if (isroot) {
		br->topology_change = 1;
		mod_timer(&br->topology_change_timer, jiffies
			  + br->bridge_forward_delay + br->bridge_max_age);
	} else if (!br->topology_change_detected) {
		br_transmit_tcn(br);
		mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time);
	}

	br->topology_change_detected = 1;
}

/* called under bridge lock */
void br_config_bpdu_generation(struct net_bridge *br)
{
	struct net_bridge_port *p;

	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED &&
		    br_is_designated_port(p))
			br_transmit_config(p);
	}
}

/* called under bridge lock */
static void br_reply(struct net_bridge_port *p)
{
	br_transmit_config(p);
}

/* called under bridge lock */
void br_configuration_update(struct net_bridge *br)
{
	br_root_selection(br);
	br_designated_port_selection(br);
}

/* called under bridge lock */
void br_become_designated_port(struct net_bridge_port *p)
{
	struct net_bridge *br;

	br = p->br;
	p->designated_root = br->designated_root;
	p->designated_cost = br->root_path_cost;
	p->designated_bridge = br->bridge_id;
	p->designated_port = p->port_id;
}


/* called under bridge lock */
static void br_make_blocking(struct net_bridge_port *p)
{
	if (p->state != BR_STATE_DISABLED &&
	    p->state != BR_STATE_BLOCKING) {
		if (p->state == BR_STATE_FORWARDING ||
		    p->state == BR_STATE_LEARNING)
			br_topology_change_detection(p->br);

		br_set_state(p, BR_STATE_BLOCKING);
		br_ifinfo_notify(RTM_NEWLINK, p);

		del_timer(&p->forward_delay_timer);
	}
}

/* called under bridge lock */
static void br_make_forwarding(struct net_bridge_port *p)
{
	struct net_bridge *br = p->br;

	if (p->state != BR_STATE_BLOCKING)
		return;

	if (br->stp_enabled == BR_NO_STP || br->forward_delay == 0) {
		br_set_state(p, BR_STATE_FORWARDING);
		br_topology_change_detection(br);
		del_timer(&p->forward_delay_timer);
	} else if (br->stp_enabled == BR_KERNEL_STP)
		br_set_state(p, BR_STATE_LISTENING);
	else
		br_set_state(p, BR_STATE_LEARNING);

	br_ifinfo_notify(RTM_NEWLINK, p);

	if (br->forward_delay != 0)
		mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
}

/* called under bridge lock */
void br_port_state_selection(struct net_bridge *br)
{
	struct net_bridge_port *p;
	unsigned int liveports = 0;

	list_for_each_entry(p, &br->port_list, list) {
		if (p->state == BR_STATE_DISABLED)
			continue;

		/* Don't change port states if userspace is handling STP */
		if (br->stp_enabled != BR_USER_STP) {
			if (p->port_no == br->root_port) {
				p->config_pending = 0;
				p->topology_change_ack = 0;
				br_make_forwarding(p);
			} else if (br_is_designated_port(p)) {
				del_timer(&p->message_age_timer);
				br_make_forwarding(p);
			} else {
				p->config_pending = 0;
				p->topology_change_ack = 0;
				br_make_blocking(p);
			}
		}

		if (p->state != BR_STATE_BLOCKING)
			br_multicast_enable_port(p);
		/* Multicast is not disabled for the port when it goes in
		 * blocking state because the timers will expire and stop by
		 * themselves without sending more queries.
		 */
		if (p->state == BR_STATE_FORWARDING)
			++liveports;
	}

	if (liveports == 0)
		netif_carrier_off(br->dev);
	else
		netif_carrier_on(br->dev);
}

/* called under bridge lock */
static void br_topology_change_acknowledge(struct net_bridge_port *p)
{
	p->topology_change_ack = 1;
	br_transmit_config(p);
}

/* called under bridge lock */
void br_received_config_bpdu(struct net_bridge_port *p,
			     const struct br_config_bpdu *bpdu)
{
	struct net_bridge *br;
	int was_root;

	br = p->br;
	was_root = br_is_root_bridge(br);

	if (br_supersedes_port_info(p, bpdu)) {
		br_record_config_information(p, bpdu);
		br_configuration_update(br);
		br_port_state_selection(br);

		if (!br_is_root_bridge(br) && was_root) {
			del_timer(&br->hello_timer);
			if (br->topology_change_detected) {
				del_timer(&br->topology_change_timer);
				br_transmit_tcn(br);

				mod_timer(&br->tcn_timer,
					  jiffies + br->bridge_hello_time);
			}
		}

		if (p->port_no == br->root_port) {
			br_record_config_timeout_values(br, bpdu);
			br_config_bpdu_generation(br);
			if (bpdu->topology_change_ack)
				br_topology_change_acknowledged(br);
		}
	} else if (br_is_designated_port(p)) {
		br_reply(p);
	}
}

/* called under bridge lock */
void br_received_tcn_bpdu(struct net_bridge_port *p)
{
	if (br_is_designated_port(p)) {
		br_info(p->br, "port %u(%s) received tcn bpdu\n",
			(unsigned int) p->port_no, p->dev->name);

		br_topology_change_detection(p->br);
		br_topology_change_acknowledge(p);
	}
}

/* Change bridge STP parameter */
int br_set_hello_time(struct net_bridge *br, unsigned long val)
{
	unsigned long t = clock_t_to_jiffies(val);

	if (t < BR_MIN_HELLO_TIME || t > BR_MAX_HELLO_TIME)
		return -ERANGE;

	spin_lock_bh(&br->lock);
	br->bridge_hello_time = t;
	if (br_is_root_bridge(br))
		br->hello_time = br->bridge_hello_time;
	spin_unlock_bh(&br->lock);
	return 0;
}

int br_set_max_age(struct net_bridge *br, unsigned long val)
{
	unsigned long t = clock_t_to_jiffies(val);

	if (t < BR_MIN_MAX_AGE || t > BR_MAX_MAX_AGE)
		return -ERANGE;

	spin_lock_bh(&br->lock);
	br->bridge_max_age = t;
	if (br_is_root_bridge(br))
		br->max_age = br->bridge_max_age;
	spin_unlock_bh(&br->lock);
	return 0;

}

/* Set time interval that dynamic forwarding entries live
 * For pure software bridge, allow values outside the 802.1
 * standard specification for special cases:
 *  0 - entry never ages (all permanant)
 *  1 - entry disappears (no persistance)
 *
 * Offloaded switch entries maybe more restrictive
 */
int br_set_ageing_time(struct net_bridge *br, u32 ageing_time)
{
	struct switchdev_attr attr = {
		.orig_dev = br->dev,
		.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
		.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP,
		.u.ageing_time = ageing_time,
	};
	unsigned long t = clock_t_to_jiffies(ageing_time);
	int err;

	err = switchdev_port_attr_set(br->dev, &attr);
	if (err && err != -EOPNOTSUPP)
		return err;

	br->ageing_time = t;
	mod_timer(&br->gc_timer, jiffies);

	return 0;
}

void __br_set_forward_delay(struct net_bridge *br, unsigned long t)
{
	br->bridge_forward_delay = t;
	if (br_is_root_bridge(br))
		br->forward_delay = br->bridge_forward_delay;
}

int br_set_forward_delay(struct net_bridge *br, unsigned long val)
{
	unsigned long t = clock_t_to_jiffies(val);
	int err = -ERANGE;

	spin_lock_bh(&br->lock);
	if (br->stp_enabled != BR_NO_STP &&
	    (t < BR_MIN_FORWARD_DELAY || t > BR_MAX_FORWARD_DELAY))
		goto unlock;

	__br_set_forward_delay(br, t);
	err = 0;

unlock:
	spin_unlock_bh(&br->lock);
	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Spanning tree protocol; generic parts
	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	#include <linux/kernel.h>
82524746	14	#include <linux/rculist.h>
38dcf357	15	#include <net/switchdev.h>
1da177e4 LT	16
	17	#include "br_private.h"
	18	#include "br_private_stp.h"
	19
	20	/* since time values in bpdu are in jiffies and then scaled (1/256)
aaca735f	21	* before sending, make sure that is at least one STP tick.
1da177e4	22	*/
aaca735f	23	#define MESSAGE_AGE_INCR ((HZ / 256) + 1)
1da177e4	24
36cbd3dc	25	static const char *const br_port_state_names[] = {
9d6f229f	26	[BR_STATE_DISABLED] = "disabled",
1da177e4	27	[BR_STATE_LISTENING] = "listening",
9d6f229f YH	28	[BR_STATE_LEARNING] = "learning",
9d6f229f YH	29	[BR_STATE_FORWARDING] = "forwarding",
1da177e4 LT	30	[BR_STATE_BLOCKING] = "blocking",
	31	};
	32
775dd692 FF	33	void br_set_state(struct net_bridge_port *p, unsigned int state)
775dd692 FF	34	{
35636062	35	struct switchdev_attr attr = {
6ff64f6f	36	.orig_dev = p->dev,
1f868398	37	.id = SWITCHDEV_ATTR_ID_PORT_STP_STATE,
0bc05d58	38	.flags = SWITCHDEV_F_DEFER,
42275bd8	39	.u.stp_state = state,
35636062	40	};
38dcf357 SF	41	int err;
38dcf357 SF	42
775dd692	43	p->state = state;
35636062	44	err = switchdev_port_attr_set(p->dev, &attr);
bbe14f54	45	if (err && err != -EOPNOTSUPP)
38dcf357 SF	46	br_warn(p->br, "error setting offload STP state on port %u(%s)\n",
38dcf357 SF	47	(unsigned int) p->port_no, p->dev->name);
7c25b16d VD	48	else
	49	br_info(p->br, "port %u(%s) entered %s state\n",
	50	(unsigned int) p->port_no, p->dev->name,
	51	br_port_state_names[p->state]);
775dd692 FF	52	}
775dd692 FF	53
1da177e4 LT	54	/* called under bridge lock */
	55	struct net_bridge_port br_get_port(struct net_bridge br, u16 port_no)
	56	{
	57	struct net_bridge_port *p;
	58
	59	list_for_each_entry_rcu(p, &br->port_list, list) {
	60	if (p->port_no == port_no)
	61	return p;
	62	}
	63
	64	return NULL;
	65	}
	66
	67	/* called under bridge lock */
9d6f229f	68	static int br_should_become_root_port(const struct net_bridge_port *p,
1da177e4 LT	69	u16 root_port)
	70	{
	71	struct net_bridge *br;
	72	struct net_bridge_port *rp;
	73	int t;
	74
	75	br = p->br;
	76	if (p->state == BR_STATE_DISABLED \|\|
	77	br_is_designated_port(p))
	78	return 0;
	79
	80	if (memcmp(&br->bridge_id, &p->designated_root, 8) <= 0)
	81	return 0;
	82
	83	if (!root_port)
	84	return 1;
	85
	86	rp = br_get_port(br, root_port);
	87
	88	t = memcmp(&p->designated_root, &rp->designated_root, 8);
	89	if (t < 0)
	90	return 1;
	91	else if (t > 0)
	92	return 0;
	93
	94	if (p->designated_cost + p->path_cost <
	95	rp->designated_cost + rp->path_cost)
	96	return 1;
	97	else if (p->designated_cost + p->path_cost >
	98	rp->designated_cost + rp->path_cost)
	99	return 0;
	100
	101	t = memcmp(&p->designated_bridge, &rp->designated_bridge, 8);
	102	if (t < 0)
	103	return 1;
	104	else if (t > 0)
	105	return 0;
	106
	107	if (p->designated_port < rp->designated_port)
	108	return 1;
	109	else if (p->designated_port > rp->designated_port)
	110	return 0;
	111
	112	if (p->port_id < rp->port_id)
	113	return 1;
	114
	115	return 0;
	116	}
	117
1007dd1a	118	static void br_root_port_block(const struct net_bridge *br,
	119	struct net_bridge_port *p)
	120	{
	121
	122	br_notice(br, "port %u(%s) tried to become root port (blocked)",
	123	(unsigned int) p->port_no, p->dev->name);
	124
775dd692	125	br_set_state(p, BR_STATE_LISTENING);
1007dd1a	126	br_ifinfo_notify(RTM_NEWLINK, p);
	127
	128	if (br->forward_delay > 0)
	129	mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
	130	}
	131
1da177e4 LT	132	/* called under bridge lock */
	133	static void br_root_selection(struct net_bridge *br)
	134	{
	135	struct net_bridge_port *p;
	136	u16 root_port = 0;
	137
	138	list_for_each_entry(p, &br->port_list, list) {
1007dd1a	139	if (!br_should_become_root_port(p, root_port))
	140	continue;
	141
	142	if (p->flags & BR_ROOT_BLOCK)
	143	br_root_port_block(br, p);
	144	else
1da177e4	145	root_port = p->port_no;
1da177e4 LT	146	}
	147
	148	br->root_port = root_port;
	149
	150	if (!root_port) {
	151	br->designated_root = br->bridge_id;
	152	br->root_path_cost = 0;
	153	} else {
	154	p = br_get_port(br, root_port);
	155	br->designated_root = p->designated_root;
	156	br->root_path_cost = p->designated_cost + p->path_cost;
	157	}
	158	}
	159
	160	/* called under bridge lock */
	161	void br_become_root_bridge(struct net_bridge *br)
	162	{
	163	br->max_age = br->bridge_max_age;
	164	br->hello_time = br->bridge_hello_time;
	165	br->forward_delay = br->bridge_forward_delay;
	166	br_topology_change_detection(br);
	167	del_timer(&br->tcn_timer);
	168
	169	if (br->dev->flags & IFF_UP) {
	170	br_config_bpdu_generation(br);
	171	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	172	}
	173	}
	174
	175	/* called under bridge lock */
	176	void br_transmit_config(struct net_bridge_port *p)
	177	{
	178	struct br_config_bpdu bpdu;
	179	struct net_bridge *br;
	180
1da177e4 LT	181	if (timer_pending(&p->hold_timer)) {
	182	p->config_pending = 1;
	183	return;
	184	}
	185
	186	br = p->br;
	187
	188	bpdu.topology_change = br->topology_change;
	189	bpdu.topology_change_ack = p->topology_change_ack;
	190	bpdu.root = br->designated_root;
	191	bpdu.root_path_cost = br->root_path_cost;
	192	bpdu.bridge_id = br->bridge_id;
	193	bpdu.port_id = p->port_id;
	194	if (br_is_root_bridge(br))
	195	bpdu.message_age = 0;
	196	else {
	197	struct net_bridge_port *root
	198	= br_get_port(br, br->root_port);
0c03150e	199	bpdu.message_age = (jiffies - root->designated_age)
1da177e4 LT	200	+ MESSAGE_AGE_INCR;
	201	}
	202	bpdu.max_age = br->max_age;
	203	bpdu.hello_time = br->hello_time;
	204	bpdu.forward_delay = br->forward_delay;
	205
	206	if (bpdu.message_age < br->max_age) {
	207	br_send_config_bpdu(p, &bpdu);
	208	p->topology_change_ack = 0;
	209	p->config_pending = 0;
76b91c32 NA	210	if (p->br->stp_enabled == BR_KERNEL_STP)
	211	mod_timer(&p->hold_timer,
	212	round_jiffies(jiffies + BR_HOLD_TIME));
1da177e4 LT	213	}
	214	}
	215
	216	/* called under bridge lock */
160d73b8	217	static void br_record_config_information(struct net_bridge_port *p,
160d73b8	218	const struct br_config_bpdu *bpdu)
1da177e4 LT	219	{
	220	p->designated_root = bpdu->root;
	221	p->designated_cost = bpdu->root_path_cost;
	222	p->designated_bridge = bpdu->bridge_id;
	223	p->designated_port = bpdu->port_id;
709e1b5c	224	p->designated_age = jiffies - bpdu->message_age;
1da177e4	225
9d6f229f	226	mod_timer(&p->message_age_timer, jiffies
9a062013	227	+ (bpdu->max_age - bpdu->message_age));
1da177e4 LT	228	}
	229
	230	/* called under bridge lock */
160d73b8	231	static void br_record_config_timeout_values(struct net_bridge *br,
1da177e4 LT	232	const struct br_config_bpdu *bpdu)
	233	{
	234	br->max_age = bpdu->max_age;
	235	br->hello_time = bpdu->hello_time;
	236	br->forward_delay = bpdu->forward_delay;
	237	br->topology_change = bpdu->topology_change;
	238	}
	239
	240	/* called under bridge lock */
	241	void br_transmit_tcn(struct net_bridge *br)
	242	{
91bc033c	243	struct net_bridge_port *p;
	244
	245	p = br_get_port(br, br->root_port);
	246	if (p)
	247	br_send_tcn_bpdu(p);
	248	else
	249	br_notice(br, "root port %u not found for topology notice\n",
	250	br->root_port);
1da177e4 LT	251	}
	252
	253	/* called under bridge lock */
	254	static int br_should_become_designated_port(const struct net_bridge_port *p)
	255	{
	256	struct net_bridge *br;
	257	int t;
	258
	259	br = p->br;
	260	if (br_is_designated_port(p))
	261	return 1;
	262
	263	if (memcmp(&p->designated_root, &br->designated_root, 8))
	264	return 1;
	265
	266	if (br->root_path_cost < p->designated_cost)
	267	return 1;
	268	else if (br->root_path_cost > p->designated_cost)
	269	return 0;
	270
	271	t = memcmp(&br->bridge_id, &p->designated_bridge, 8);
	272	if (t < 0)
	273	return 1;
	274	else if (t > 0)
	275	return 0;
	276
	277	if (p->port_id < p->designated_port)
	278	return 1;
	279
	280	return 0;
	281	}
	282
	283	/* called under bridge lock */
	284	static void br_designated_port_selection(struct net_bridge *br)
	285	{
	286	struct net_bridge_port *p;
	287
	288	list_for_each_entry(p, &br->port_list, list) {
	289	if (p->state != BR_STATE_DISABLED &&
	290	br_should_become_designated_port(p))
	291	br_become_designated_port(p);
	292
	293	}
	294	}
	295
	296	/* called under bridge lock */
160d73b8	297	static int br_supersedes_port_info(const struct net_bridge_port *p,
160d73b8	298	const struct br_config_bpdu *bpdu)
1da177e4 LT	299	{
	300	int t;
	301
	302	t = memcmp(&bpdu->root, &p->designated_root, 8);
	303	if (t < 0)
	304	return 1;
	305	else if (t > 0)
	306	return 0;
	307
	308	if (bpdu->root_path_cost < p->designated_cost)
	309	return 1;
	310	else if (bpdu->root_path_cost > p->designated_cost)
	311	return 0;
	312
	313	t = memcmp(&bpdu->bridge_id, &p->designated_bridge, 8);
	314	if (t < 0)
	315	return 1;
	316	else if (t > 0)
	317	return 0;
	318
	319	if (memcmp(&bpdu->bridge_id, &p->br->bridge_id, 8))
	320	return 1;
	321
	322	if (bpdu->port_id <= p->designated_port)
	323	return 1;
	324
	325	return 0;
	326	}
	327
	328	/* called under bridge lock */
160d73b8	329	static void br_topology_change_acknowledged(struct net_bridge *br)
1da177e4 LT	330	{
	331	br->topology_change_detected = 0;
	332	del_timer(&br->tcn_timer);
	333	}
	334
	335	/* called under bridge lock */
	336	void br_topology_change_detection(struct net_bridge *br)
	337	{
	338	int isroot = br_is_root_bridge(br);
	339
4f0611af SH	340	if (br->stp_enabled != BR_KERNEL_STP)
	341	return;
	342
28a16c97	343	br_info(br, "topology change detected, %s\n",
1da177e4 LT	344	isroot ? "propagating" : "sending tcn bpdu");
	345
	346	if (isroot) {
	347	br->topology_change = 1;
	348	mod_timer(&br->topology_change_timer, jiffies
	349	+ br->bridge_forward_delay + br->bridge_max_age);
	350	} else if (!br->topology_change_detected) {
	351	br_transmit_tcn(br);
	352	mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time);
	353	}
	354
	355	br->topology_change_detected = 1;
	356	}
	357
	358	/* called under bridge lock */
	359	void br_config_bpdu_generation(struct net_bridge *br)
	360	{
	361	struct net_bridge_port *p;
	362
	363	list_for_each_entry(p, &br->port_list, list) {
	364	if (p->state != BR_STATE_DISABLED &&
	365	br_is_designated_port(p))
	366	br_transmit_config(p);
	367	}
	368	}
	369
	370	/* called under bridge lock */
160d73b8	371	static void br_reply(struct net_bridge_port *p)
1da177e4 LT	372	{
	373	br_transmit_config(p);
	374	}
	375
	376	/* called under bridge lock */
	377	void br_configuration_update(struct net_bridge *br)
	378	{
	379	br_root_selection(br);
	380	br_designated_port_selection(br);
	381	}
	382
	383	/* called under bridge lock */
	384	void br_become_designated_port(struct net_bridge_port *p)
	385	{
	386	struct net_bridge *br;
	387
	388	br = p->br;
	389	p->designated_root = br->designated_root;
	390	p->designated_cost = br->root_path_cost;
	391	p->designated_bridge = br->bridge_id;
	392	p->designated_port = p->port_id;
	393	}
	394
	395
	396	/* called under bridge lock */
	397	static void br_make_blocking(struct net_bridge_port *p)
	398	{
	399	if (p->state != BR_STATE_DISABLED &&
	400	p->state != BR_STATE_BLOCKING) {
	401	if (p->state == BR_STATE_FORWARDING \|\|
	402	p->state == BR_STATE_LEARNING)
	403	br_topology_change_detection(p->br);
	404
775dd692	405	br_set_state(p, BR_STATE_BLOCKING);
4ecb961c	406	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	407
1da177e4 LT	408	del_timer(&p->forward_delay_timer);
	409	}
	410	}
	411
	412	/* called under bridge lock */
	413	static void br_make_forwarding(struct net_bridge_port *p)
	414	{
ef647f13	415	struct net_bridge *br = p->br;
9cde0708	416
ef647f13 SH	417	if (p->state != BR_STATE_BLOCKING)
	418	return;
	419
a461c029	420	if (br->stp_enabled == BR_NO_STP \|\| br->forward_delay == 0) {
775dd692	421	br_set_state(p, BR_STATE_FORWARDING);
ef647f13 SH	422	br_topology_change_detection(br);
ef647f13 SH	423	del_timer(&p->forward_delay_timer);
160d73b8	424	} else if (br->stp_enabled == BR_KERNEL_STP)
775dd692	425	br_set_state(p, BR_STATE_LISTENING);
ef647f13	426	else
775dd692	427	br_set_state(p, BR_STATE_LEARNING);
ef647f13	428
4ecb961c	429	br_ifinfo_notify(RTM_NEWLINK, p);
ef647f13 SH	430
	431	if (br->forward_delay != 0)
	432	mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
1da177e4 LT	433	}
	434
	435	/* called under bridge lock */
	436	void br_port_state_selection(struct net_bridge *br)
	437	{
	438	struct net_bridge_port *p;
1faa4356	439	unsigned int liveports = 0;
1da177e4 LT	440
1da177e4 LT	441	list_for_each_entry(p, &br->port_list, list) {
1faa4356	442	if (p->state == BR_STATE_DISABLED)
	443	continue;
	444
b03b6dd5 VD	445	/* Don't change port states if userspace is handling STP */
	446	if (br->stp_enabled != BR_USER_STP) {
	447	if (p->port_no == br->root_port) {
	448	p->config_pending = 0;
	449	p->topology_change_ack = 0;
	450	br_make_forwarding(p);
	451	} else if (br_is_designated_port(p)) {
	452	del_timer(&p->message_age_timer);
	453	br_make_forwarding(p);
	454	} else {
	455	p->config_pending = 0;
	456	p->topology_change_ack = 0;
	457	br_make_blocking(p);
	458	}
1da177e4 LT	459	}
1da177e4 LT	460
7ce42de1 NA	461	if (p->state != BR_STATE_BLOCKING)
7ce42de1 NA	462	br_multicast_enable_port(p);
9aa66382 NA	463	/* Multicast is not disabled for the port when it goes in
	464	* blocking state because the timers will expire and stop by
	465	* themselves without sending more queries.
	466	*/
1faa4356	467	if (p->state == BR_STATE_FORWARDING)
1faa4356	468	++liveports;
1da177e4	469	}
1faa4356	470
	471	if (liveports == 0)
	472	netif_carrier_off(br->dev);
	473	else
	474	netif_carrier_on(br->dev);
1da177e4 LT	475	}
	476
	477	/* called under bridge lock */
160d73b8	478	static void br_topology_change_acknowledge(struct net_bridge_port *p)
1da177e4 LT	479	{
	480	p->topology_change_ack = 1;
	481	br_transmit_config(p);
	482	}
	483
	484	/* called under bridge lock */
160d73b8	485	void br_received_config_bpdu(struct net_bridge_port *p,
160d73b8	486	const struct br_config_bpdu *bpdu)
1da177e4 LT	487	{
	488	struct net_bridge *br;
	489	int was_root;
9d6f229f	490
1da177e4 LT	491	br = p->br;
	492	was_root = br_is_root_bridge(br);
	493
	494	if (br_supersedes_port_info(p, bpdu)) {
	495	br_record_config_information(p, bpdu);
	496	br_configuration_update(br);
	497	br_port_state_selection(br);
	498
	499	if (!br_is_root_bridge(br) && was_root) {
	500	del_timer(&br->hello_timer);
	501	if (br->topology_change_detected) {
	502	del_timer(&br->topology_change_timer);
	503	br_transmit_tcn(br);
	504
9d6f229f	505	mod_timer(&br->tcn_timer,
1da177e4 LT	506	jiffies + br->bridge_hello_time);
	507	}
	508	}
	509
	510	if (p->port_no == br->root_port) {
	511	br_record_config_timeout_values(br, bpdu);
	512	br_config_bpdu_generation(br);
	513	if (bpdu->topology_change_ack)
	514	br_topology_change_acknowledged(br);
	515	}
9d6f229f YH	516	} else if (br_is_designated_port(p)) {
9d6f229f YH	517	br_reply(p);
1da177e4 LT	518	}
	519	}
	520
	521	/* called under bridge lock */
	522	void br_received_tcn_bpdu(struct net_bridge_port *p)
	523	{
	524	if (br_is_designated_port(p)) {
28a16c97	525	br_info(p->br, "port %u(%s) received tcn bpdu\n",
95c96174	526	(unsigned int) p->port_no, p->dev->name);
1da177e4 LT	527
	528	br_topology_change_detection(p->br);
	529	br_topology_change_acknowledge(p);
	530	}
	531	}
14f98f25	532
	533	/* Change bridge STP parameter */
	534	int br_set_hello_time(struct net_bridge *br, unsigned long val)
	535	{
	536	unsigned long t = clock_t_to_jiffies(val);
	537
	538	if (t < BR_MIN_HELLO_TIME \|\| t > BR_MAX_HELLO_TIME)
	539	return -ERANGE;
	540
	541	spin_lock_bh(&br->lock);
	542	br->bridge_hello_time = t;
	543	if (br_is_root_bridge(br))
	544	br->hello_time = br->bridge_hello_time;
	545	spin_unlock_bh(&br->lock);
	546	return 0;
	547	}
	548
	549	int br_set_max_age(struct net_bridge *br, unsigned long val)
	550	{
	551	unsigned long t = clock_t_to_jiffies(val);
	552
	553	if (t < BR_MIN_MAX_AGE \|\| t > BR_MAX_MAX_AGE)
	554	return -ERANGE;
	555
	556	spin_lock_bh(&br->lock);
	557	br->bridge_max_age = t;
	558	if (br_is_root_bridge(br))
	559	br->max_age = br->bridge_max_age;
	560	spin_unlock_bh(&br->lock);
	561	return 0;
	562
	563	}
	564
4c656c13 SH	565	/* Set time interval that dynamic forwarding entries live
	566	* For pure software bridge, allow values outside the 802.1
	567	* standard specification for special cases:
	568	* 0 - entry never ages (all permanant)
	569	* 1 - entry disappears (no persistance)
	570	*
	571	* Offloaded switch entries maybe more restrictive
	572	*/
c62987bb SF	573	int br_set_ageing_time(struct net_bridge *br, u32 ageing_time)
	574	{
	575	struct switchdev_attr attr = {
6ff64f6f	576	.orig_dev = br->dev,
c62987bb SF	577	.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
	578	.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP,
	579	.u.ageing_time = ageing_time,
	580	};
	581	unsigned long t = clock_t_to_jiffies(ageing_time);
	582	int err;
	583
c62987bb	584	err = switchdev_port_attr_set(br->dev, &attr);
5e263f71	585	if (err && err != -EOPNOTSUPP)
c62987bb SF	586	return err;
	587
	588	br->ageing_time = t;
	589	mod_timer(&br->gc_timer, jiffies);
	590
	591	return 0;
	592	}
	593
be4f154d HX	594	void __br_set_forward_delay(struct net_bridge *br, unsigned long t)
	595	{
	596	br->bridge_forward_delay = t;
	597	if (br_is_root_bridge(br))
	598	br->forward_delay = br->bridge_forward_delay;
	599	}
	600
14f98f25	601	int br_set_forward_delay(struct net_bridge *br, unsigned long val)
	602	{
	603	unsigned long t = clock_t_to_jiffies(val);
8a921265	604	int err = -ERANGE;
14f98f25	605
34c2d9fb	606	spin_lock_bh(&br->lock);
8a921265 VY	607	if (br->stp_enabled != BR_NO_STP &&
	608	(t < BR_MIN_FORWARD_DELAY \|\| t > BR_MAX_FORWARD_DELAY))
	609	goto unlock;
	610
be4f154d	611	__br_set_forward_delay(br, t);
8a921265 VY	612	err = 0;
	613
	614	unlock:
14f98f25	615	spin_unlock_bh(&br->lock);
8a921265	616	return err;
14f98f25	617	}