[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 "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)
{
	p->port_id = br_make_port_id(p->priority, p->port_no);
	br_become_designated_port(p);
	p->state = BR_STATE_BLOCKING;
	p->topology_change_ack = 0;
	p->config_pending = 0;
}

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

	spin_lock_bh(&br->lock);
	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);
	p->state = 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);
	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 };

	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	if (r == 0) {
		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 */
		spin_lock_bh(&br->lock);
		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 };

	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 */
		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);

	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;
}

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

	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);
}

/* 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->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>
1da177e4 LT	18
	19	#include "br_private.h"
	20	#include "br_private_stp.h"
	21
	22
	23	/* Port id is composed of priority and port number.
14f98f25	24	* NB: some bits of priority are dropped to
1da177e4 LT	25	* make room for more ports.
	26	*/
	27	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	28	{
9d6f229f	29	return ((u16)priority << BR_PORT_BITS)
1da177e4 LT	30	\| (port_no & ((1<<BR_PORT_BITS)-1));
	31	}
	32
14f98f25	33	#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
14f98f25	34
1da177e4 LT	35	/* called under bridge lock */
	36	void br_init_port(struct net_bridge_port *p)
	37	{
	38	p->port_id = br_make_port_id(p->priority, p->port_no);
	39	br_become_designated_port(p);
	40	p->state = BR_STATE_BLOCKING;
	41	p->topology_change_ack = 0;
	42	p->config_pending = 0;
1da177e4 LT	43	}
	44
	45	/* called under bridge lock */
	46	void br_stp_enable_bridge(struct net_bridge *br)
	47	{
	48	struct net_bridge_port *p;
	49
	50	spin_lock_bh(&br->lock);
	51	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	52	mod_timer(&br->gc_timer, jiffies + HZ/10);
9d6f229f	53
1da177e4 LT	54	br_config_bpdu_generation(br);
	55
	56	list_for_each_entry(p, &br->port_list, list) {
576eb625	57	if (netif_running(p->dev) && netif_oper_up(p->dev))
1da177e4 LT	58	br_stp_enable_port(p);
	59
	60	}
	61	spin_unlock_bh(&br->lock);
	62	}
	63
	64	/* NO locks held */
	65	void br_stp_disable_bridge(struct net_bridge *br)
	66	{
	67	struct net_bridge_port *p;
	68
78872ccb	69	spin_lock_bh(&br->lock);
1da177e4 LT	70	list_for_each_entry(p, &br->port_list, list) {
	71	if (p->state != BR_STATE_DISABLED)
	72	br_stp_disable_port(p);
	73
	74	}
	75
	76	br->topology_change = 0;
	77	br->topology_change_detected = 0;
78872ccb	78	spin_unlock_bh(&br->lock);
1da177e4 LT	79
	80	del_timer_sync(&br->hello_timer);
	81	del_timer_sync(&br->topology_change_timer);
	82	del_timer_sync(&br->tcn_timer);
	83	del_timer_sync(&br->gc_timer);
	84	}
	85
	86	/* called under bridge lock */
	87	void br_stp_enable_port(struct net_bridge_port *p)
	88	{
	89	br_init_port(p);
	90	br_port_state_selection(p->br);
28a16c97	91	br_log_state(p);
4ecb961c	92	br_ifinfo_notify(RTM_NEWLINK, p);
1da177e4 LT	93	}
	94
	95	/* called under bridge lock */
	96	void br_stp_disable_port(struct net_bridge_port *p)
	97	{
28a16c97	98	struct net_bridge *br = p->br;
1da177e4 LT	99	int wasroot;
1da177e4 LT	100
1da177e4 LT	101	wasroot = br_is_root_bridge(br);
	102	br_become_designated_port(p);
	103	p->state = BR_STATE_DISABLED;
	104	p->topology_change_ack = 0;
	105	p->config_pending = 0;
	106
5200959b	107	br_log_state(p);
4ecb961c	108	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	109
1da177e4 LT	110	del_timer(&p->message_age_timer);
	111	del_timer(&p->forward_delay_timer);
	112	del_timer(&p->hold_timer);
	113
1a620698	114	br_fdb_delete_by_port(br, p, 0);
3fe2d7c7	115	br_multicast_disable_port(p);
1a620698	116
1da177e4 LT	117	br_configuration_update(br);
	118
	119	br_port_state_selection(br);
	120
	121	if (br_is_root_bridge(br) && !wasroot)
	122	br_become_root_bridge(br);
	123	}
	124
9cde0708 SH	125	static void br_stp_start(struct net_bridge *br)
	126	{
	127	int r;
	128	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	129	char *envp[] = { NULL };
	130
86313c48	131	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
9cde0708 SH	132	if (r == 0) {
9cde0708 SH	133	br->stp_enabled = BR_USER_STP;
28a16c97	134	br_debug(br, "userspace STP started\n");
9cde0708 SH	135	} else {
9cde0708 SH	136	br->stp_enabled = BR_KERNEL_STP;
28a16c97	137	br_debug(br, "using kernel STP\n");
9cde0708 SH	138
	139	/* To start timers on any ports left in blocking */
	140	spin_lock_bh(&br->lock);
	141	br_port_state_selection(br);
	142	spin_unlock_bh(&br->lock);
	143	}
	144	}
	145
	146	static void br_stp_stop(struct net_bridge *br)
	147	{
	148	int r;
	149	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	150	char *envp[] = { NULL };
	151
	152	if (br->stp_enabled == BR_USER_STP) {
1a9180a2	153	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
28a16c97	154	br_info(br, "userspace STP stopped, return code %d\n", r);
9cde0708 SH	155
	156	/* To start timers on any ports left in blocking */
	157	spin_lock_bh(&br->lock);
	158	br_port_state_selection(br);
	159	spin_unlock_bh(&br->lock);
	160	}
	161
	162	br->stp_enabled = BR_NO_STP;
	163	}
	164
	165	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	166	{
	167	ASSERT_RTNL();
	168
	169	if (val) {
	170	if (br->stp_enabled == BR_NO_STP)
	171	br_stp_start(br);
	172	} else {
	173	if (br->stp_enabled != BR_NO_STP)
	174	br_stp_stop(br);
	175	}
	176	}
	177
1da177e4	178	/* called under bridge lock */
4505a3ef	179	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	180	{
9a7b6ef9	181	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	182	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	183	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	184	struct net_bridge_port *p;
	185	int wasroot;
	186
	187	wasroot = br_is_root_bridge(br);
	188
	189	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	190	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	191	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	192
	193	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	194	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	195	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	196
9a7b6ef9	197	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	198	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	199	}
	200
	201	br_configuration_update(br);
	202	br_port_state_selection(br);
	203	if (br_is_root_bridge(br) && !wasroot)
	204	br_become_root_bridge(br);
	205	}
	206
9a7b6ef9	207	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	208	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	209
1da177e4 LT	210	/* called under bridge lock */
edf947f1	211	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	212	{
19bb3506 EK	213	const unsigned char *br_mac_zero =
19bb3506 EK	214	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	215	const unsigned char *addr = br_mac_zero;
	216	struct net_bridge_port *p;
	217
92c0574f	218	/* user has chosen a value so keep it */
b2748267	219	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	220	return false;
92c0574f	221
1da177e4 LT	222	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	223	if (addr == br_mac_zero \|\|
554c9a8e	224	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	225	addr = p->dev->dev_addr;
	226
	227	}
	228
9a7b6ef9	229	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	230	return false; /* no change */
	231
	232	br_stp_change_bridge_id(br, addr);
	233	return true;
1da177e4 LT	234	}
	235
	236	/* called under bridge lock */
	237	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	238	{
	239	struct net_bridge_port *p;
	240	int wasroot;
	241
	242	wasroot = br_is_root_bridge(br);
	243
	244	list_for_each_entry(p, &br->port_list, list) {
	245	if (p->state != BR_STATE_DISABLED &&
	246	br_is_designated_port(p)) {
	247	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	248	p->designated_bridge.prio[1] = newprio & 0xFF;
	249	}
	250
	251	}
	252
	253	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	254	br->bridge_id.prio[1] = newprio & 0xFF;
	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
	261	/* called under bridge lock */
14f98f25	262	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	263	{
14f98f25	264	port_id new_port_id;
	265
	266	if (newprio > BR_MAX_PORT_PRIORITY)
	267	return -ERANGE;
1da177e4	268
14f98f25	269	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	270	if (br_is_designated_port(p))
	271	p->designated_port = new_port_id;
	272
	273	p->port_id = new_port_id;
	274	p->priority = newprio;
	275	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	276	p->port_id < p->designated_port) {
	277	br_become_designated_port(p);
	278	br_port_state_selection(p->br);
	279	}
14f98f25	280
14f98f25	281	return 0;
1da177e4 LT	282	}
	283
	284	/* called under bridge lock */
14f98f25	285	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	286	{
14f98f25	287	if (path_cost < BR_MIN_PATH_COST \|\|
	288	path_cost > BR_MAX_PATH_COST)
	289	return -ERANGE;
	290
1da177e4 LT	291	p->path_cost = path_cost;
	292	br_configuration_update(p->br);
	293	br_port_state_selection(p->br);
14f98f25	294	return 0;
1da177e4 LT	295	}
	296
	297	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	298	{
	299	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	300	id->prio[0], id->prio[1],
	301	id->addr[0], id->addr[1], id->addr[2],
	302	id->addr[3], id->addr[4], id->addr[5]);
	303	}