br_stp_timer.c revision e3efe08e9a2c24232711dc573bf2decd2d93e335 
1/*
2 *	Spanning tree protocol; timer-related code
3 *	Linux ethernet bridge
4 *
5 *	Authors:
6 *	Lennert Buytenhek		<buytenh@gnu.org>
7 *
8 *	$Id: br_stp_timer.c,v 1.3 2000/05/05 02:17:17 davem Exp $
9 *
10 *	This program is free software; you can redistribute it and/or
11 *	modify it under the terms of the GNU General Public License
12 *	as published by the Free Software Foundation; either version
13 *	2 of the License, or (at your option) any later version.
14 */
15
16#include <linux/kernel.h>
17#include <linux/times.h>
18#include <linux/smp_lock.h>
19
20#include "br_private.h"
21#include "br_private_stp.h"
22
23/* called under bridge lock */
24static int br_is_designated_for_some_port(const struct net_bridge *br)
25{
26	struct net_bridge_port *p;
27
28	list_for_each_entry(p, &br->port_list, list) {
29		if (p->state != BR_STATE_DISABLED &&
30		    !memcmp(&p->designated_bridge, &br->bridge_id, 8))
31			return 1;
32	}
33
34	return 0;
35}
36
37static void br_hello_timer_expired(unsigned long arg)
38{
39	struct net_bridge *br = (struct net_bridge *)arg;
40
41	pr_debug("%s: hello timer expired\n", br->dev->name);
42	spin_lock(&br->lock);
43	if (br->dev->flags & IFF_UP) {
44		br_config_bpdu_generation(br);
45
46		mod_timer(&br->hello_timer, jiffies + br->hello_time);
47	}
48	spin_unlock(&br->lock);
49}
50
51static void br_message_age_timer_expired(unsigned long arg)
52{
53	struct net_bridge_port *p = (struct net_bridge_port *) arg;
54	struct net_bridge *br = p->br;
55	const bridge_id *id = &p->designated_bridge;
56	int was_root;
57
58	if (p->state == BR_STATE_DISABLED)
59		return;
60
61
62	pr_info("%s: neighbor %.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x lost on port %d(%s)\n",
63		br->dev->name,
64		id->prio[0], id->prio[1],
65		id->addr[0], id->addr[1], id->addr[2],
66		id->addr[3], id->addr[4], id->addr[5],
67		p->port_no, p->dev->name);
68
69	/*
70	 * According to the spec, the message age timer cannot be
71	 * running when we are the root bridge. So..  this was_root
72	 * check is redundant. I'm leaving it in for now, though.
73	 */
74	spin_lock(&br->lock);
75	if (p->state == BR_STATE_DISABLED)
76		goto unlock;
77	was_root = br_is_root_bridge(br);
78
79	br_become_designated_port(p);
80	br_configuration_update(br);
81	br_port_state_selection(br);
82	if (br_is_root_bridge(br) && !was_root)
83		br_become_root_bridge(br);
84 unlock:
85	spin_unlock(&br->lock);
86}
87
88static void br_forward_delay_timer_expired(unsigned long arg)
89{
90	struct net_bridge_port *p = (struct net_bridge_port *) arg;
91	struct net_bridge *br = p->br;
92
93	pr_debug("%s: %d(%s) forward delay timer\n",
94		 br->dev->name, p->port_no, p->dev->name);
95	spin_lock(&br->lock);
96	if (p->state == BR_STATE_LISTENING) {
97		p->state = BR_STATE_LEARNING;
98		mod_timer(&p->forward_delay_timer,
99			  jiffies + br->forward_delay);
100	} else if (p->state == BR_STATE_LEARNING) {
101		p->state = BR_STATE_FORWARDING;
102		if (br_is_designated_for_some_port(br))
103			br_topology_change_detection(br);
104	}
105	br_log_state(p);
106	spin_unlock(&br->lock);
107}
108
109static void br_tcn_timer_expired(unsigned long arg)
110{
111	struct net_bridge *br = (struct net_bridge *) arg;
112
113	pr_debug("%s: tcn timer expired\n", br->dev->name);
114	spin_lock(&br->lock);
115	if (br->dev->flags & IFF_UP) {
116		br_transmit_tcn(br);
117
118		mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time);
119	}
120	spin_unlock(&br->lock);
121}
122
123static void br_topology_change_timer_expired(unsigned long arg)
124{
125	struct net_bridge *br = (struct net_bridge *) arg;
126
127	pr_debug("%s: topo change timer expired\n", br->dev->name);
128	spin_lock(&br->lock);
129	br->topology_change_detected = 0;
130	br->topology_change = 0;
131	spin_unlock(&br->lock);
132}
133
134static void br_hold_timer_expired(unsigned long arg)
135{
136	struct net_bridge_port *p = (struct net_bridge_port *) arg;
137
138	pr_debug("%s: %d(%s) hold timer expired\n",
139		 p->br->dev->name,  p->port_no, p->dev->name);
140
141	spin_lock(&p->br->lock);
142	if (p->config_pending)
143		br_transmit_config(p);
144	spin_unlock(&p->br->lock);
145}
146
147static inline void br_timer_init(struct timer_list *timer,
148			  void (*_function)(unsigned long),
149			  unsigned long _data)
150{
151	init_timer(timer);
152	timer->function = _function;
153	timer->data = _data;
154}
155
156void br_stp_timer_init(struct net_bridge *br)
157{
158	br_timer_init(&br->hello_timer, br_hello_timer_expired,
159		      (unsigned long) br);
160
161	br_timer_init(&br->tcn_timer, br_tcn_timer_expired,
162		      (unsigned long) br);
163
164	br_timer_init(&br->topology_change_timer,
165		      br_topology_change_timer_expired,
166		      (unsigned long) br);
167
168	br_timer_init(&br->gc_timer, br_fdb_cleanup, (unsigned long) br);
169}
170
171void br_stp_port_timer_init(struct net_bridge_port *p)
172{
173	br_timer_init(&p->message_age_timer, br_message_age_timer_expired,
174		      (unsigned long) p);
175
176	br_timer_init(&p->forward_delay_timer, br_forward_delay_timer_expired,
177		      (unsigned long) p);
178
179	br_timer_init(&p->hold_timer, br_hold_timer_expired,
180		      (unsigned long) p);
181}
182
183/* Report ticks left (in USER_HZ) used for API */
184unsigned long br_timer_value(const struct timer_list *timer)
185{
186	return timer_pending(timer)
187		? jiffies_to_clock_t(timer->expires - jiffies) : 0;
188}
189