[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 "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 ((p->dev->flags & IFF_UP) && netif_carrier_ok(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;

	br_log_state(p);

	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_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 compare_ether_addr() */
	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 (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
			memcpy(p->designated_bridge.addr, addr, ETH_ALEN);

		if (!compare_ether_addr(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 compare_ether_addr() */
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->flags & BR_SET_MAC_ADDR)
		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 (compare_ether_addr(br->bridge_id.addr, addr) == 0)
		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) {
	57	if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
	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
28a16c97	101	br_log_state(p);
1da177e4 LT	102
	103	wasroot = br_is_root_bridge(br);
	104	br_become_designated_port(p);
	105	p->state = BR_STATE_DISABLED;
	106	p->topology_change_ack = 0;
	107	p->config_pending = 0;
	108
4ecb961c	109	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	110
1da177e4 LT	111	del_timer(&p->message_age_timer);
	112	del_timer(&p->forward_delay_timer);
	113	del_timer(&p->hold_timer);
	114
1a620698	115	br_fdb_delete_by_port(br, p, 0);
3fe2d7c7	116	br_multicast_disable_port(p);
1a620698	117
1da177e4 LT	118	br_configuration_update(br);
	119
	120	br_port_state_selection(br);
	121
	122	if (br_is_root_bridge(br) && !wasroot)
	123	br_become_root_bridge(br);
	124	}
	125
9cde0708 SH	126	static void br_stp_start(struct net_bridge *br)
	127	{
	128	int r;
	129	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	130	char *envp[] = { NULL };
	131
86313c48	132	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
9cde0708 SH	133	if (r == 0) {
9cde0708 SH	134	br->stp_enabled = BR_USER_STP;
28a16c97	135	br_debug(br, "userspace STP started\n");
9cde0708 SH	136	} else {
9cde0708 SH	137	br->stp_enabled = BR_KERNEL_STP;
28a16c97	138	br_debug(br, "using kernel STP\n");
9cde0708 SH	139
	140	/* To start timers on any ports left in blocking */
	141	spin_lock_bh(&br->lock);
	142	br_port_state_selection(br);
	143	spin_unlock_bh(&br->lock);
	144	}
	145	}
	146
	147	static void br_stp_stop(struct net_bridge *br)
	148	{
	149	int r;
	150	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	151	char *envp[] = { NULL };
	152
	153	if (br->stp_enabled == BR_USER_STP) {
1a9180a2	154	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
28a16c97	155	br_info(br, "userspace STP stopped, return code %d\n", r);
9cde0708 SH	156
	157	/* To start timers on any ports left in blocking */
	158	spin_lock_bh(&br->lock);
	159	br_port_state_selection(br);
	160	spin_unlock_bh(&br->lock);
	161	}
	162
	163	br->stp_enabled = BR_NO_STP;
	164	}
	165
	166	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	167	{
	168	ASSERT_RTNL();
	169
	170	if (val) {
	171	if (br->stp_enabled == BR_NO_STP)
	172	br_stp_start(br);
	173	} else {
	174	if (br->stp_enabled != BR_NO_STP)
	175	br_stp_stop(br);
	176	}
	177	}
	178
1da177e4	179	/* called under bridge lock */
4505a3ef	180	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	181	{
19bb3506 EK	182	/* should be aligned on 2 bytes for compare_ether_addr() */
	183	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	184	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	185	struct net_bridge_port *p;
	186	int wasroot;
	187
	188	wasroot = br_is_root_bridge(br);
	189
	190	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	191	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	192	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	193
	194	list_for_each_entry(p, &br->port_list, list) {
6ede2463	195	if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
1da177e4 LT	196	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	197
6ede2463	198	if (!compare_ether_addr(p->designated_root.addr, oldaddr))
1da177e4 LT	199	memcpy(p->designated_root.addr, addr, ETH_ALEN);
	200
	201	}
	202
	203	br_configuration_update(br);
	204	br_port_state_selection(br);
	205	if (br_is_root_bridge(br) && !wasroot)
	206	br_become_root_bridge(br);
	207	}
	208
19bb3506 EK	209	/* should be aligned on 2 bytes for compare_ether_addr() */
19bb3506 EK	210	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	211
1da177e4 LT	212	/* called under bridge lock */
edf947f1	213	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	214	{
19bb3506 EK	215	const unsigned char *br_mac_zero =
19bb3506 EK	216	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	217	const unsigned char *addr = br_mac_zero;
	218	struct net_bridge_port *p;
	219
92c0574f SH	220	/* user has chosen a value so keep it */
92c0574f SH	221	if (br->flags & BR_SET_MAC_ADDR)
1459a3cc	222	return false;
92c0574f	223
1da177e4 LT	224	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	225	if (addr == br_mac_zero \|\|
554c9a8e	226	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	227	addr = p->dev->dev_addr;
	228
	229	}
	230
edf947f1	231	if (compare_ether_addr(br->bridge_id.addr, addr) == 0)
	232	return false; /* no change */
	233
	234	br_stp_change_bridge_id(br, addr);
	235	return true;
1da177e4 LT	236	}
	237
	238	/* called under bridge lock */
	239	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	240	{
	241	struct net_bridge_port *p;
	242	int wasroot;
	243
	244	wasroot = br_is_root_bridge(br);
	245
	246	list_for_each_entry(p, &br->port_list, list) {
	247	if (p->state != BR_STATE_DISABLED &&
	248	br_is_designated_port(p)) {
	249	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	250	p->designated_bridge.prio[1] = newprio & 0xFF;
	251	}
	252
	253	}
	254
	255	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	256	br->bridge_id.prio[1] = newprio & 0xFF;
	257	br_configuration_update(br);
	258	br_port_state_selection(br);
	259	if (br_is_root_bridge(br) && !wasroot)
	260	br_become_root_bridge(br);
	261	}
	262
	263	/* called under bridge lock */
14f98f25	264	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	265	{
14f98f25	266	port_id new_port_id;
	267
	268	if (newprio > BR_MAX_PORT_PRIORITY)
	269	return -ERANGE;
1da177e4	270
14f98f25	271	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	272	if (br_is_designated_port(p))
	273	p->designated_port = new_port_id;
	274
	275	p->port_id = new_port_id;
	276	p->priority = newprio;
	277	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	278	p->port_id < p->designated_port) {
	279	br_become_designated_port(p);
	280	br_port_state_selection(p->br);
	281	}
14f98f25	282
14f98f25	283	return 0;
1da177e4 LT	284	}
	285
	286	/* called under bridge lock */
14f98f25	287	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	288	{
14f98f25	289	if (path_cost < BR_MIN_PATH_COST \|\|
	290	path_cost > BR_MAX_PATH_COST)
	291	return -ERANGE;
	292
1da177e4 LT	293	p->path_cost = path_cost;
	294	br_configuration_update(p->br);
	295	br_port_state_selection(p->br);
14f98f25	296	return 0;
1da177e4 LT	297	}
	298
	299	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	300	{
	301	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	302	id->prio[0], id->prio[1],
	303	id->addr[0], id->addr[1], id->addr[2],
	304	id->addr[3], id->addr[4], id->addr[5]);
	305	}