[GitHub/mt8127/android_kernel_alcatel_ttab.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 };

	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");
	} 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 };

	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;
}

/* 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
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
a1506150 HFS	131	if (net_eq(dev_net(br->dev), &init_net))
	132	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	133	else
	134	r = -ENOENT;
dc45b846 HX	135
	136	spin_lock_bh(&br->lock);
	137
	138	if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
	139	__br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
d14db232	140	else if (br->bridge_forward_delay > BR_MAX_FORWARD_DELAY)
dc45b846 HX	141	__br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
dc45b846 HX	142
9cde0708 SH	143	if (r == 0) {
9cde0708 SH	144	br->stp_enabled = BR_USER_STP;
28a16c97	145	br_debug(br, "userspace STP started\n");
9cde0708 SH	146	} else {
9cde0708 SH	147	br->stp_enabled = BR_KERNEL_STP;
28a16c97	148	br_debug(br, "using kernel STP\n");
9cde0708 SH	149
9cde0708 SH	150	/* To start timers on any ports left in blocking */
9cde0708	151	br_port_state_selection(br);
9cde0708	152	}
dc45b846 HX	153
dc45b846 HX	154	spin_unlock_bh(&br->lock);
9cde0708 SH	155	}
	156
	157	static void br_stp_stop(struct net_bridge *br)
	158	{
	159	int r;
	160	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	161	char *envp[] = { NULL };
	162
	163	if (br->stp_enabled == BR_USER_STP) {
1a9180a2	164	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
28a16c97	165	br_info(br, "userspace STP stopped, return code %d\n", r);
9cde0708 SH	166
	167	/* To start timers on any ports left in blocking */
	168	spin_lock_bh(&br->lock);
	169	br_port_state_selection(br);
	170	spin_unlock_bh(&br->lock);
	171	}
	172
	173	br->stp_enabled = BR_NO_STP;
	174	}
	175
	176	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	177	{
	178	ASSERT_RTNL();
	179
	180	if (val) {
	181	if (br->stp_enabled == BR_NO_STP)
	182	br_stp_start(br);
	183	} else {
	184	if (br->stp_enabled != BR_NO_STP)
	185	br_stp_stop(br);
	186	}
	187	}
	188
1da177e4	189	/* called under bridge lock */
4505a3ef	190	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	191	{
9a7b6ef9	192	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506 EK	193	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
19bb3506 EK	194	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	195	struct net_bridge_port *p;
	196	int wasroot;
	197
	198	wasroot = br_is_root_bridge(br);
	199
	200	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	201	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	202	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	203
	204	list_for_each_entry(p, &br->port_list, list) {
9a7b6ef9	205	if (ether_addr_equal(p->designated_bridge.addr, oldaddr))
1da177e4 LT	206	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	207
9a7b6ef9	208	if (ether_addr_equal(p->designated_root.addr, oldaddr))
1da177e4	209	memcpy(p->designated_root.addr, addr, ETH_ALEN);
1da177e4 LT	210	}
	211
	212	br_configuration_update(br);
	213	br_port_state_selection(br);
	214	if (br_is_root_bridge(br) && !wasroot)
	215	br_become_root_bridge(br);
	216	}
	217
9a7b6ef9	218	/* should be aligned on 2 bytes for ether_addr_equal() */
19bb3506	219	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	220
1da177e4 LT	221	/* called under bridge lock */
edf947f1	222	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	223	{
19bb3506 EK	224	const unsigned char *br_mac_zero =
19bb3506 EK	225	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	226	const unsigned char *addr = br_mac_zero;
	227	struct net_bridge_port *p;
	228
92c0574f	229	/* user has chosen a value so keep it */
b2748267	230	if (br->dev->addr_assign_type == NET_ADDR_SET)
1459a3cc	231	return false;
92c0574f	232
1da177e4 LT	233	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	234	if (addr == br_mac_zero \|\|
554c9a8e	235	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	236	addr = p->dev->dev_addr;
	237
	238	}
	239
9a7b6ef9	240	if (ether_addr_equal(br->bridge_id.addr, addr))
edf947f1	241	return false; /* no change */
	242
	243	br_stp_change_bridge_id(br, addr);
	244	return true;
1da177e4 LT	245	}
1da177e4 LT	246
019b1332	247	/* Acquires and releases bridge lock */
1da177e4 LT	248	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	249	{
	250	struct net_bridge_port *p;
	251	int wasroot;
	252
019b1332	253	spin_lock_bh(&br->lock);
1da177e4 LT	254	wasroot = br_is_root_bridge(br);
	255
	256	list_for_each_entry(p, &br->port_list, list) {
	257	if (p->state != BR_STATE_DISABLED &&
	258	br_is_designated_port(p)) {
	259	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	260	p->designated_bridge.prio[1] = newprio & 0xFF;
	261	}
	262
	263	}
	264
	265	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	266	br->bridge_id.prio[1] = newprio & 0xFF;
	267	br_configuration_update(br);
	268	br_port_state_selection(br);
	269	if (br_is_root_bridge(br) && !wasroot)
	270	br_become_root_bridge(br);
019b1332	271	spin_unlock_bh(&br->lock);
1da177e4 LT	272	}
	273
	274	/* called under bridge lock */
14f98f25	275	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	276	{
14f98f25	277	port_id new_port_id;
	278
	279	if (newprio > BR_MAX_PORT_PRIORITY)
	280	return -ERANGE;
1da177e4	281
14f98f25	282	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	283	if (br_is_designated_port(p))
	284	p->designated_port = new_port_id;
	285
	286	p->port_id = new_port_id;
	287	p->priority = newprio;
	288	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	289	p->port_id < p->designated_port) {
	290	br_become_designated_port(p);
	291	br_port_state_selection(p->br);
	292	}
14f98f25	293
14f98f25	294	return 0;
1da177e4 LT	295	}
	296
	297	/* called under bridge lock */
14f98f25	298	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	299	{
14f98f25	300	if (path_cost < BR_MIN_PATH_COST \|\|
	301	path_cost > BR_MAX_PATH_COST)
	302	return -ERANGE;
	303
8f3359bd	304	p->flags \|= BR_ADMIN_COST;
1da177e4 LT	305	p->path_cost = path_cost;
	306	br_configuration_update(p->br);
	307	br_port_state_selection(p->br);
14f98f25	308	return 0;
1da177e4 LT	309	}
	310
	311	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	312	{
	313	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	314	id->prio[0], id->prio[1],
	315	id->addr[0], id->addr[1], id->addr[2],
	316	id->addr[3], id->addr[4], id->addr[5]);
	317	}