xref: /openbmc/linux/net/bridge/br_stp_timer.c (revision 64c70b1c)
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 
19 #include "br_private.h"
20 #include "br_private_stp.h"
21 
22 /* called under bridge lock */
23 static int br_is_designated_for_some_port(const struct net_bridge *br)
24 {
25 	struct net_bridge_port *p;
26 
27 	list_for_each_entry(p, &br->port_list, list) {
28 		if (p->state != BR_STATE_DISABLED &&
29 		    !memcmp(&p->designated_bridge, &br->bridge_id, 8))
30 			return 1;
31 	}
32 
33 	return 0;
34 }
35 
36 static void br_hello_timer_expired(unsigned long arg)
37 {
38 	struct net_bridge *br = (struct net_bridge *)arg;
39 
40 	pr_debug("%s: hello timer expired\n", br->dev->name);
41 	spin_lock(&br->lock);
42 	if (br->dev->flags & IFF_UP) {
43 		br_config_bpdu_generation(br);
44 
45 		mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time));
46 	}
47 	spin_unlock(&br->lock);
48 }
49 
50 static void br_message_age_timer_expired(unsigned long arg)
51 {
52 	struct net_bridge_port *p = (struct net_bridge_port *) arg;
53 	struct net_bridge *br = p->br;
54 	const bridge_id *id = &p->designated_bridge;
55 	int was_root;
56 
57 	if (p->state == BR_STATE_DISABLED)
58 		return;
59 
60 
61 	pr_info("%s: neighbor %.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x lost on port %d(%s)\n",
62 		br->dev->name,
63 		id->prio[0], id->prio[1],
64 		id->addr[0], id->addr[1], id->addr[2],
65 		id->addr[3], id->addr[4], id->addr[5],
66 		p->port_no, p->dev->name);
67 
68 	/*
69 	 * According to the spec, the message age timer cannot be
70 	 * running when we are the root bridge. So..  this was_root
71 	 * check is redundant. I'm leaving it in for now, though.
72 	 */
73 	spin_lock(&br->lock);
74 	if (p->state == BR_STATE_DISABLED)
75 		goto unlock;
76 	was_root = br_is_root_bridge(br);
77 
78 	br_become_designated_port(p);
79 	br_configuration_update(br);
80 	br_port_state_selection(br);
81 	if (br_is_root_bridge(br) && !was_root)
82 		br_become_root_bridge(br);
83  unlock:
84 	spin_unlock(&br->lock);
85 }
86 
87 static void br_forward_delay_timer_expired(unsigned long arg)
88 {
89 	struct net_bridge_port *p = (struct net_bridge_port *) arg;
90 	struct net_bridge *br = p->br;
91 
92 	pr_debug("%s: %d(%s) forward delay timer\n",
93 		 br->dev->name, p->port_no, p->dev->name);
94 	spin_lock(&br->lock);
95 	if (p->state == BR_STATE_LISTENING) {
96 		p->state = BR_STATE_LEARNING;
97 		mod_timer(&p->forward_delay_timer,
98 			  jiffies + br->forward_delay);
99 	} else if (p->state == BR_STATE_LEARNING) {
100 		p->state = BR_STATE_FORWARDING;
101 		if (br_is_designated_for_some_port(br))
102 			br_topology_change_detection(br);
103 	}
104 	br_log_state(p);
105 	spin_unlock(&br->lock);
106 }
107 
108 static void br_tcn_timer_expired(unsigned long arg)
109 {
110 	struct net_bridge *br = (struct net_bridge *) arg;
111 
112 	pr_debug("%s: tcn timer expired\n", br->dev->name);
113 	spin_lock(&br->lock);
114 	if (br->dev->flags & IFF_UP) {
115 		br_transmit_tcn(br);
116 
117 		mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time);
118 	}
119 	spin_unlock(&br->lock);
120 }
121 
122 static void br_topology_change_timer_expired(unsigned long arg)
123 {
124 	struct net_bridge *br = (struct net_bridge *) arg;
125 
126 	pr_debug("%s: topo change timer expired\n", br->dev->name);
127 	spin_lock(&br->lock);
128 	br->topology_change_detected = 0;
129 	br->topology_change = 0;
130 	spin_unlock(&br->lock);
131 }
132 
133 static void br_hold_timer_expired(unsigned long arg)
134 {
135 	struct net_bridge_port *p = (struct net_bridge_port *) arg;
136 
137 	pr_debug("%s: %d(%s) hold timer expired\n",
138 		 p->br->dev->name,  p->port_no, p->dev->name);
139 
140 	spin_lock(&p->br->lock);
141 	if (p->config_pending)
142 		br_transmit_config(p);
143 	spin_unlock(&p->br->lock);
144 }
145 
146 void br_stp_timer_init(struct net_bridge *br)
147 {
148 	setup_timer(&br->hello_timer, br_hello_timer_expired,
149 		      (unsigned long) br);
150 
151 	setup_timer(&br->tcn_timer, br_tcn_timer_expired,
152 		      (unsigned long) br);
153 
154 	setup_timer(&br->topology_change_timer,
155 		      br_topology_change_timer_expired,
156 		      (unsigned long) br);
157 
158 	setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br);
159 }
160 
161 void br_stp_port_timer_init(struct net_bridge_port *p)
162 {
163 	setup_timer(&p->message_age_timer, br_message_age_timer_expired,
164 		      (unsigned long) p);
165 
166 	setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired,
167 		      (unsigned long) p);
168 
169 	setup_timer(&p->hold_timer, br_hold_timer_expired,
170 		      (unsigned long) p);
171 }
172 
173 /* Report ticks left (in USER_HZ) used for API */
174 unsigned long br_timer_value(const struct timer_list *timer)
175 {
176 	return timer_pending(timer)
177 		? jiffies_to_clock_t(timer->expires - jiffies) : 0;
178 }
179