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/if_bridge.h>
18 #include <linux/smp_lock.h>
19 #include <asm/uaccess.h>
20 #include "br_private.h"
21 #include "br_private_stp.h"
22
dump_bridge_id(bridge_id * id)23 static void dump_bridge_id(bridge_id *id)
24 {
25 printk("%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", id->prio[0],
26 id->prio[1], id->addr[0], id->addr[1], id->addr[2], id->addr[3],
27 id->addr[4], id->addr[5]);
28 }
29
30 /* called under bridge lock */
br_is_designated_for_some_port(struct net_bridge * br)31 static int br_is_designated_for_some_port(struct net_bridge *br)
32 {
33 struct net_bridge_port *p;
34
35 p = br->port_list;
36 while (p != NULL) {
37 if (p->state != BR_STATE_DISABLED &&
38 !memcmp(&p->designated_bridge, &br->bridge_id, 8))
39 return 1;
40
41 p = p->next;
42 }
43
44 return 0;
45 }
46
47 /* called under bridge lock */
br_hello_timer_expired(struct net_bridge * br)48 static void br_hello_timer_expired(struct net_bridge *br)
49 {
50 br_config_bpdu_generation(br);
51 br_timer_set(&br->hello_timer, jiffies);
52 }
53
54 /* called under bridge lock */
br_message_age_timer_expired(struct net_bridge_port * p)55 static void br_message_age_timer_expired(struct net_bridge_port *p)
56 {
57 struct net_bridge *br;
58 int was_root;
59
60 br = p->br;
61 printk(KERN_INFO "%s: ", br->dev.name);
62 printk("neighbour ");
63 dump_bridge_id(&p->designated_bridge);
64 printk(" lost on port %i(%s)\n", p->port_no, p->dev->name);
65
66 /*
67 * According to the spec, the message age timer cannot be
68 * running when we are the root bridge. So.. this was_root
69 * check is redundant. I'm leaving it in for now, though.
70 */
71 was_root = br_is_root_bridge(br);
72
73 br_become_designated_port(p);
74 br_configuration_update(br);
75 br_port_state_selection(br);
76 if (br_is_root_bridge(br) && !was_root)
77 br_become_root_bridge(br);
78 }
79
80 /* called under bridge lock */
br_forward_delay_timer_expired(struct net_bridge_port * p)81 static void br_forward_delay_timer_expired(struct net_bridge_port *p)
82 {
83 if (p->state == BR_STATE_LISTENING) {
84 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
85 p->br->dev.name, p->port_no, p->dev->name, "learning");
86
87 p->state = BR_STATE_LEARNING;
88 br_timer_set(&p->forward_delay_timer, jiffies);
89 } else if (p->state == BR_STATE_LEARNING) {
90 printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
91 p->br->dev.name, p->port_no, p->dev->name, "forwarding");
92
93 p->state = BR_STATE_FORWARDING;
94 if (br_is_designated_for_some_port(p->br))
95 br_topology_change_detection(p->br);
96 }
97 }
98
99 /* called under bridge lock */
br_tcn_timer_expired(struct net_bridge * br)100 static void br_tcn_timer_expired(struct net_bridge *br)
101 {
102 printk(KERN_INFO "%s: retransmitting tcn bpdu\n", br->dev.name);
103 br_transmit_tcn(br);
104 br_timer_set(&br->tcn_timer, jiffies);
105 }
106
107 /* called under bridge lock */
br_topology_change_timer_expired(struct net_bridge * br)108 static void br_topology_change_timer_expired(struct net_bridge *br)
109 {
110 br->topology_change_detected = 0;
111 br->topology_change = 0;
112 }
113
114 /* called under bridge lock */
br_hold_timer_expired(struct net_bridge_port * p)115 static void br_hold_timer_expired(struct net_bridge_port *p)
116 {
117 if (p->config_pending)
118 br_transmit_config(p);
119 }
120
121 /* called under bridge lock */
br_check_port_timers(struct net_bridge_port * p)122 static void br_check_port_timers(struct net_bridge_port *p)
123 {
124 if (br_timer_has_expired(&p->message_age_timer, p->br->max_age)) {
125 br_timer_clear(&p->message_age_timer);
126 br_message_age_timer_expired(p);
127 }
128
129 if (br_timer_has_expired(&p->forward_delay_timer, p->br->forward_delay)) {
130 br_timer_clear(&p->forward_delay_timer);
131 br_forward_delay_timer_expired(p);
132 }
133
134 if (br_timer_has_expired(&p->hold_timer, BR_HOLD_TIME)) {
135 br_timer_clear(&p->hold_timer);
136 br_hold_timer_expired(p);
137 }
138 }
139
140 /* called under bridge lock */
br_check_timers(struct net_bridge * br)141 static void br_check_timers(struct net_bridge *br)
142 {
143 struct net_bridge_port *p;
144
145 if (br_timer_has_expired(&br->gc_timer, br->gc_interval)) {
146 br_timer_set(&br->gc_timer, jiffies);
147 br_fdb_cleanup(br);
148 }
149
150 if (br_timer_has_expired(&br->hello_timer, br->hello_time)) {
151 br_timer_clear(&br->hello_timer);
152 br_hello_timer_expired(br);
153 }
154
155 if (br_timer_has_expired(&br->tcn_timer, br->bridge_hello_time)) {
156 br_timer_clear(&br->tcn_timer);
157 br_tcn_timer_expired(br);
158 }
159
160 if (br_timer_has_expired(&br->topology_change_timer, br->bridge_forward_delay + br->bridge_max_age)) {
161 br_timer_clear(&br->topology_change_timer);
162 br_topology_change_timer_expired(br);
163 }
164
165 p = br->port_list;
166 while (p != NULL) {
167 if (p->state != BR_STATE_DISABLED)
168 br_check_port_timers(p);
169
170 p = p->next;
171 }
172 }
173
br_tick(unsigned long __data)174 void br_tick(unsigned long __data)
175 {
176 struct net_bridge *br = (struct net_bridge *)__data;
177
178 read_lock(&br->lock);
179 br_check_timers(br);
180 read_unlock(&br->lock);
181
182 br->tick.expires = jiffies + 1;
183 add_timer(&br->tick);
184 }
185