[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/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: least significant 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));
}

/* 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);
}

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

	br = p->br;
	printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
	       br->dev->name, p->port_no, p->dev->name, "disabled");

	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;

	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_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;
		printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
	} else {
		br->stp_enabled = BR_KERNEL_STP;
		printk(KERN_INFO "%s: starting userspace STP failed, "
				"starting kernel STP\n", br->dev->name);

		/* 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, 1);
		printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
			br->dev->name, 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 */
void 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;

	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))
		br_stp_change_bridge_id(br, addr);
}

/* 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 */
void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
{
	port_id 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);
	}
}

/* called under bridge lock */
void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
{
	p->path_cost = path_cost;
	br_configuration_update(p->br);
	br_port_state_selection(p->br);
}

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>
6ede2463	15	#include <linux/etherdevice.h>
11dc1f36	16	#include <linux/rtnetlink.h>
1da177e4 LT	17
	18	#include "br_private.h"
	19	#include "br_private_stp.h"
	20
	21
	22	/* Port id is composed of priority and port number.
	23	* NB: least significant bits of priority are dropped to
	24	* make room for more ports.
	25	*/
	26	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	27	{
9d6f229f	28	return ((u16)priority << BR_PORT_BITS)
1da177e4 LT	29	\| (port_no & ((1<<BR_PORT_BITS)-1));
	30	}
	31
	32	/* called under bridge lock */
	33	void br_init_port(struct net_bridge_port *p)
	34	{
	35	p->port_id = br_make_port_id(p->priority, p->port_no);
	36	br_become_designated_port(p);
	37	p->state = BR_STATE_BLOCKING;
	38	p->topology_change_ack = 0;
	39	p->config_pending = 0;
1da177e4 LT	40	}
	41
	42	/* called under bridge lock */
	43	void br_stp_enable_bridge(struct net_bridge *br)
	44	{
	45	struct net_bridge_port *p;
	46
	47	spin_lock_bh(&br->lock);
	48	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	49	mod_timer(&br->gc_timer, jiffies + HZ/10);
9d6f229f	50
1da177e4 LT	51	br_config_bpdu_generation(br);
	52
	53	list_for_each_entry(p, &br->port_list, list) {
	54	if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
	55	br_stp_enable_port(p);
	56
	57	}
	58	spin_unlock_bh(&br->lock);
	59	}
	60
	61	/* NO locks held */
	62	void br_stp_disable_bridge(struct net_bridge *br)
	63	{
	64	struct net_bridge_port *p;
	65
78872ccb	66	spin_lock_bh(&br->lock);
1da177e4 LT	67	list_for_each_entry(p, &br->port_list, list) {
	68	if (p->state != BR_STATE_DISABLED)
	69	br_stp_disable_port(p);
	70
	71	}
	72
	73	br->topology_change = 0;
	74	br->topology_change_detected = 0;
78872ccb	75	spin_unlock_bh(&br->lock);
1da177e4 LT	76
	77	del_timer_sync(&br->hello_timer);
	78	del_timer_sync(&br->topology_change_timer);
	79	del_timer_sync(&br->tcn_timer);
	80	del_timer_sync(&br->gc_timer);
	81	}
	82
	83	/* called under bridge lock */
	84	void br_stp_enable_port(struct net_bridge_port *p)
	85	{
	86	br_init_port(p);
	87	br_port_state_selection(p->br);
	88	}
	89
	90	/* called under bridge lock */
	91	void br_stp_disable_port(struct net_bridge_port *p)
	92	{
	93	struct net_bridge *br;
	94	int wasroot;
	95
	96	br = p->br;
	97	printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
	98	br->dev->name, p->port_no, p->dev->name, "disabled");
	99
	100	wasroot = br_is_root_bridge(br);
	101	br_become_designated_port(p);
	102	p->state = BR_STATE_DISABLED;
	103	p->topology_change_ack = 0;
	104	p->config_pending = 0;
	105
	106	del_timer(&p->message_age_timer);
	107	del_timer(&p->forward_delay_timer);
	108	del_timer(&p->hold_timer);
	109
1a620698 SH	110	br_fdb_delete_by_port(br, p, 0);
1a620698 SH	111
1da177e4 LT	112	br_configuration_update(br);
	113
	114	br_port_state_selection(br);
	115
	116	if (br_is_root_bridge(br) && !wasroot)
	117	br_become_root_bridge(br);
	118	}
	119
9cde0708 SH	120	static void br_stp_start(struct net_bridge *br)
	121	{
	122	int r;
	123	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	124	char *envp[] = { NULL };
	125
86313c48	126	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
9cde0708 SH	127	if (r == 0) {
	128	br->stp_enabled = BR_USER_STP;
	129	printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
	130	} else {
	131	br->stp_enabled = BR_KERNEL_STP;
	132	printk(KERN_INFO "%s: starting userspace STP failed, "
02f44315	133	"starting kernel STP\n", br->dev->name);
9cde0708 SH	134
	135	/* To start timers on any ports left in blocking */
	136	spin_lock_bh(&br->lock);
	137	br_port_state_selection(br);
	138	spin_unlock_bh(&br->lock);
	139	}
	140	}
	141
	142	static void br_stp_stop(struct net_bridge *br)
	143	{
	144	int r;
	145	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	146	char *envp[] = { NULL };
	147
	148	if (br->stp_enabled == BR_USER_STP) {
	149	r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
	150	printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
	151	br->dev->name, r);
	152
	153
	154	/* To start timers on any ports left in blocking */
	155	spin_lock_bh(&br->lock);
	156	br_port_state_selection(br);
	157	spin_unlock_bh(&br->lock);
	158	}
	159
	160	br->stp_enabled = BR_NO_STP;
	161	}
	162
	163	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	164	{
	165	ASSERT_RTNL();
	166
	167	if (val) {
	168	if (br->stp_enabled == BR_NO_STP)
	169	br_stp_start(br);
	170	} else {
	171	if (br->stp_enabled != BR_NO_STP)
	172	br_stp_stop(br);
	173	}
	174	}
	175
1da177e4	176	/* called under bridge lock */
4505a3ef	177	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	178	{
19bb3506 EK	179	/* should be aligned on 2 bytes for compare_ether_addr() */
	180	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	181	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	182	struct net_bridge_port *p;
	183	int wasroot;
	184
	185	wasroot = br_is_root_bridge(br);
	186
	187	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	188	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	189	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	190
	191	list_for_each_entry(p, &br->port_list, list) {
6ede2463	192	if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
1da177e4 LT	193	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	194
6ede2463	195	if (!compare_ether_addr(p->designated_root.addr, oldaddr))
1da177e4 LT	196	memcpy(p->designated_root.addr, addr, ETH_ALEN);
	197
	198	}
	199
	200	br_configuration_update(br);
	201	br_port_state_selection(br);
	202	if (br_is_root_bridge(br) && !wasroot)
	203	br_become_root_bridge(br);
	204	}
	205
19bb3506 EK	206	/* should be aligned on 2 bytes for compare_ether_addr() */
19bb3506 EK	207	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	208
	209	/* called under bridge lock */
	210	void br_stp_recalculate_bridge_id(struct net_bridge *br)
	211	{
19bb3506 EK	212	const unsigned char *br_mac_zero =
19bb3506 EK	213	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	214	const unsigned char *addr = br_mac_zero;
	215	struct net_bridge_port *p;
	216
92c0574f SH	217	/* user has chosen a value so keep it */
	218	if (br->flags & BR_SET_MAC_ADDR)
	219	return;
	220
1da177e4 LT	221	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	222	if (addr == br_mac_zero \|\|
554c9a8e	223	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	224	addr = p->dev->dev_addr;
	225
	226	}
	227
6ede2463	228	if (compare_ether_addr(br->bridge_id.addr, addr))
1da177e4 LT	229	br_stp_change_bridge_id(br, addr);
	230	}
	231
	232	/* called under bridge lock */
	233	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	234	{
	235	struct net_bridge_port *p;
	236	int wasroot;
	237
	238	wasroot = br_is_root_bridge(br);
	239
	240	list_for_each_entry(p, &br->port_list, list) {
	241	if (p->state != BR_STATE_DISABLED &&
	242	br_is_designated_port(p)) {
	243	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	244	p->designated_bridge.prio[1] = newprio & 0xFF;
	245	}
	246
	247	}
	248
	249	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	250	br->bridge_id.prio[1] = newprio & 0xFF;
	251	br_configuration_update(br);
	252	br_port_state_selection(br);
	253	if (br_is_root_bridge(br) && !wasroot)
	254	br_become_root_bridge(br);
	255	}
	256
	257	/* called under bridge lock */
	258	void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
	259	{
	260	port_id new_port_id = br_make_port_id(newprio, p->port_no);
	261
	262	if (br_is_designated_port(p))
	263	p->designated_port = new_port_id;
	264
	265	p->port_id = new_port_id;
	266	p->priority = newprio;
	267	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	268	p->port_id < p->designated_port) {
	269	br_become_designated_port(p);
	270	br_port_state_selection(p->br);
	271	}
	272	}
	273
	274	/* called under bridge lock */
	275	void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
	276	{
	277	p->path_cost = path_cost;
	278	br_configuration_update(p->br);
	279	br_port_state_selection(p->br);
	280	}
	281
	282	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	283	{
	284	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	285	id->prio[0], id->prio[1],
	286	id->addr[0], id->addr[1], id->addr[2],
	287	id->addr[3], id->addr[4], id->addr[5]);
	288	}