[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 void br_stp_start(struct net_bridge *br)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	char *envp[] = { NULL };
	struct net_bridge_port *p;

	if (net_eq(dev_net(br->dev), &init_net))
		r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	else
		r = -ENOENT;

	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 (r == 0) {
		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)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	char *envp[] = { NULL };
	struct net_bridge_port *p;

	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 */
		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
	1	/*
	2	* Spanning tree protocol; interface code
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
	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>
	15	#include <linux/kmod.h>
	16	#include <linux/etherdevice.h>
	17	#include <linux/rtnetlink.h>
	18	#include <net/switchdev.h>
	19
	20	#include "br_private.h"
	21	#include "br_private_stp.h"
	22
	23
	24	/* Port id is composed of priority and port number.
	25	* NB: some bits of priority are dropped to
	26	* make room for more ports.
	27	*/
	28	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	29	{
	30	return ((u16)priority << BR_PORT_BITS)
	31	\| (port_no & ((1<<BR_PORT_BITS)-1));
	32	}
	33
	34	#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
	35
	36	/* called under bridge lock */
	37	void br_init_port(struct net_bridge_port *p)
	38	{
	39	struct switchdev_attr attr = {
	40	.orig_dev = p->dev,
	41	.id = SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME,
	42	.flags = SWITCHDEV_F_SKIP_EOPNOTSUPP \| SWITCHDEV_F_DEFER,
	43	.u.ageing_time = jiffies_to_clock_t(p->br->ageing_time),
	44	};
	45	int err;
	46
	47	p->port_id = br_make_port_id(p->priority, p->port_no);
	48	br_become_designated_port(p);
	49	br_set_state(p, BR_STATE_BLOCKING);
	50	p->topology_change_ack = 0;
	51	p->config_pending = 0;
	52
	53	err = switchdev_port_attr_set(p->dev, &attr);
	54	if (err && err != -EOPNOTSUPP)
	55	netdev_err(p->dev, "failed to set HW ageing time\n");
	56	}
	57
	58	/* NO locks held */
	59	void br_stp_enable_bridge(struct net_bridge *br)
	60	{
	61	struct net_bridge_port *p;
	62
	63	spin_lock_bh(&br->lock);
	64	if (br->stp_enabled == BR_KERNEL_STP)
	65	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	66	mod_timer(&br->gc_timer, jiffies + HZ/10);
	67
	68	br_config_bpdu_generation(br);
	69
	70	list_for_each_entry(p, &br->port_list, list) {
	71	if (netif_running(p->dev) && netif_oper_up(p->dev))
	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
	83	spin_lock_bh(&br->lock);
	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;
	92	spin_unlock_bh(&br->lock);
	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);
	105	br_ifinfo_notify(RTM_NEWLINK, p);
	106	}
	107
	108	/* called under bridge lock */
	109	void br_stp_disable_port(struct net_bridge_port *p)
	110	{
	111	struct net_bridge *br = p->br;
	112	int wasroot;
	113
	114	wasroot = br_is_root_bridge(br);
	115	br_become_designated_port(p);
	116	br_set_state(p, BR_STATE_DISABLED);
	117	p->topology_change_ack = 0;
	118	p->config_pending = 0;
	119
	120	br_ifinfo_notify(RTM_NEWLINK, p);
	121
	122	del_timer(&p->message_age_timer);
	123	del_timer(&p->forward_delay_timer);
	124	del_timer(&p->hold_timer);
	125
	126	br_fdb_delete_by_port(br, p, 0, 0);
	127	br_multicast_disable_port(p);
	128
	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
	137	static void br_stp_start(struct net_bridge *br)
	138	{
	139	int r;
	140	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	141	char *envp[] = { NULL };
	142	struct net_bridge_port *p;
	143
	144	if (net_eq(dev_net(br->dev), &init_net))
	145	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	146	else
	147	r = -ENOENT;
	148
	149	spin_lock_bh(&br->lock);
	150
	151	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	152	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
	153	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
	154	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
	155
	156	if (r == 0) {
	157	br->stp_enabled = BR_USER_STP;
	158	br_debug(br, "userspace STP started\n");
	159	/* Stop hello and hold timers */
	160	del_timer(&br->hello_timer);
	161	list_for_each_entry(p, &br->port_list, list)
	162	del_timer(&p->hold_timer);
	163	} else {
	164	br->stp_enabled = BR_KERNEL_STP;
	165	br_debug(br, "using kernel STP\n");
	166
	167	/* To start timers on any ports left in blocking */
	168	br_port_state_selection(br);
	169	}
	170
	171	spin_unlock_bh(&br->lock);
	172	}
	173
	174	static void br_stp_stop(struct net_bridge *br)
	175	{
	176	int r;
	177	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	178	char *envp[] = { NULL };
	179	struct net_bridge_port *p;
	180
	181	if (br->stp_enabled == BR_USER_STP) {
	182	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	183	br_info(br, "userspace STP stopped, return code %d\n", r);
	184
	185	/* To start timers on any ports left in blocking */
	186	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	187	list_for_each_entry(p, &br->port_list, list)
	188	mod_timer(&p->hold_timer,
	189	round_jiffies(jiffies + BR_HOLD_TIME));
	190	spin_lock_bh(&br->lock);
	191	br_port_state_selection(br);
	192	spin_unlock_bh(&br->lock);
	193	}
	194
	195	br->stp_enabled = BR_NO_STP;
	196	}
	197
	198	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	199	{
	200	ASSERT_RTNL();
	201
	202	if (val) {
	203	if (br->stp_enabled == BR_NO_STP)
	204	br_stp_start(br);
	205	} else {
	206	if (br->stp_enabled != BR_NO_STP)
	207	br_stp_stop(br);
	208	}
	209	}
	210
	211	/* called under bridge lock */
	212	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
	213	{
	214	/* should be aligned on 2 bytes for ether_addr_equal() */
	215	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	216	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
	217	struct net_bridge_port *p;
	218	int wasroot;
	219
	220	wasroot = br_is_root_bridge(br);
	221
	222	br_fdb_change_mac_address(br, addr);
	223
	224	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	225	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	226	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	227
	228	list_for_each_entry(p, &br->port_list, list) {
	229	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
	230	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
	231
	232	if (ether_addr_equal(p->designated_root.addr, oldaddr))
	233	memcpy(p->designated_root.addr, addr, ETH_ALEN);
	234	}
	235
	236	br_configuration_update(br);
	237	br_port_state_selection(br);
	238	if (br_is_root_bridge(br) && !wasroot)
	239	br_become_root_bridge(br);
	240	}
	241
	242	/* should be aligned on 2 bytes for ether_addr_equal() */
	243	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
	244
	245	/* called under bridge lock */
	246	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
	247	{
	248	const unsigned char *br_mac_zero =
	249	(const unsigned char *)br_mac_zero_aligned;
	250	const unsigned char *addr = br_mac_zero;
	251	struct net_bridge_port *p;
	252
	253	/* user has chosen a value so keep it */
	254	if (br->dev->addr_assign_type == NET_ADDR_SET)
	255	return false;
	256
	257	list_for_each_entry(p, &br->port_list, list) {
	258	if (addr == br_mac_zero \|\|
	259	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
	260	addr = p->dev->dev_addr;
	261
	262	}
	263
	264	if (ether_addr_equal(br->bridge_id.addr, addr))
	265	return false; /* no change */
	266
	267	br_stp_change_bridge_id(br, addr);
	268	return true;
	269	}
	270
	271	/* Acquires and releases bridge lock */
	272	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	273	{
	274	struct net_bridge_port *p;
	275	int wasroot;
	276
	277	spin_lock_bh(&br->lock);
	278	wasroot = br_is_root_bridge(br);
	279
	280	list_for_each_entry(p, &br->port_list, list) {
	281	if (p->state != BR_STATE_DISABLED &&
	282	br_is_designated_port(p)) {
	283	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	284	p->designated_bridge.prio[1] = newprio & 0xFF;
	285	}
	286
	287	}
	288
	289	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	290	br->bridge_id.prio[1] = newprio & 0xFF;
	291	br_configuration_update(br);
	292	br_port_state_selection(br);
	293	if (br_is_root_bridge(br) && !wasroot)
	294	br_become_root_bridge(br);
	295	spin_unlock_bh(&br->lock);
	296	}
	297
	298	/* called under bridge lock */
	299	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
	300	{
	301	port_id new_port_id;
	302
	303	if (newprio > BR_MAX_PORT_PRIORITY)
	304	return -ERANGE;
	305
	306	new_port_id = br_make_port_id(newprio, p->port_no);
	307	if (br_is_designated_port(p))
	308	p->designated_port = new_port_id;
	309
	310	p->port_id = new_port_id;
	311	p->priority = newprio;
	312	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	313	p->port_id < p->designated_port) {
	314	br_become_designated_port(p);
	315	br_port_state_selection(p->br);
	316	}
	317
	318	return 0;
	319	}
	320
	321	/* called under bridge lock */
	322	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
	323	{
	324	if (path_cost < BR_MIN_PATH_COST \|\|
	325	path_cost > BR_MAX_PATH_COST)
	326	return -ERANGE;
	327
	328	p->flags \|= BR_ADMIN_COST;
	329	p->path_cost = path_cost;
	330	br_configuration_update(p->br);
	331	br_port_state_selection(p->br);
	332	return 0;
	333	}
	334
	335	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	336	{
	337	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	338	id->prio[0], id->prio[1],
	339	id->addr[0], id->addr[1], id->addr[2],
	340	id->addr[3], id->addr[4], id->addr[5]);
	341	}