1 /*
2 * Spanning tree protocol; timer-related 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/times.h>
16
17 #include "br_private.h"
18 #include "br_private_stp.h"
19
20 /* called under bridge lock */
br_is_designated_for_some_port(const struct net_bridge * br)21 static int br_is_designated_for_some_port(const struct net_bridge *br)
22 {
23 struct net_bridge_port *p;
24
25 list_for_each_entry(p, &br->port_list, list) {
26 if (p->state != BR_STATE_DISABLED &&
27 !memcmp(&p->designated_bridge, &br->bridge_id, 8))
28 return 1;
29 }
30
31 return 0;
32 }
33
br_hello_timer_expired(unsigned long arg)34 static void br_hello_timer_expired(unsigned long arg)
35 {
36 struct net_bridge *br = (struct net_bridge *)arg;
37
38 br_debug(br, "hello timer expired\n");
39 spin_lock(&br->lock);
40 if (br->dev->flags & IFF_UP) {
41 br_config_bpdu_generation(br);
42
43 mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time));
44 }
45 spin_unlock(&br->lock);
46 }
47
br_message_age_timer_expired(unsigned long arg)48 static void br_message_age_timer_expired(unsigned long arg)
49 {
50 struct net_bridge_port *p = (struct net_bridge_port *) arg;
51 struct net_bridge *br = p->br;
52 const bridge_id *id = &p->designated_bridge;
53 int was_root;
54
55 if (p->state == BR_STATE_DISABLED)
56 return;
57
58 br_info(br, "port %u(%s) neighbor %.2x%.2x.%pM lost\n",
59 (unsigned) p->port_no, p->dev->name,
60 id->prio[0], id->prio[1], &id->addr);
61
62 /*
63 * According to the spec, the message age timer cannot be
64 * running when we are the root bridge. So.. this was_root
65 * check is redundant. I'm leaving it in for now, though.
66 */
67 spin_lock(&br->lock);
68 if (p->state == BR_STATE_DISABLED)
69 goto unlock;
70 was_root = br_is_root_bridge(br);
71
72 br_become_designated_port(p);
73 br_configuration_update(br);
74 br_port_state_selection(br);
75 if (br_is_root_bridge(br) && !was_root)
76 br_become_root_bridge(br);
77 unlock:
78 spin_unlock(&br->lock);
79 }
80
br_forward_delay_timer_expired(unsigned long arg)81 static void br_forward_delay_timer_expired(unsigned long arg)
82 {
83 struct net_bridge_port *p = (struct net_bridge_port *) arg;
84 struct net_bridge *br = p->br;
85
86 br_debug(br, "port %u(%s) forward delay timer\n",
87 (unsigned) p->port_no, p->dev->name);
88 spin_lock(&br->lock);
89 if (p->state == BR_STATE_LISTENING) {
90 p->state = BR_STATE_LEARNING;
91 mod_timer(&p->forward_delay_timer,
92 jiffies + br->forward_delay);
93 } else if (p->state == BR_STATE_LEARNING) {
94 p->state = BR_STATE_FORWARDING;
95 if (br_is_designated_for_some_port(br))
96 br_topology_change_detection(br);
97 netif_carrier_on(br->dev);
98 }
99 br_log_state(p);
100 br_ifinfo_notify(RTM_NEWLINK, p);
101 spin_unlock(&br->lock);
102 }
103
br_tcn_timer_expired(unsigned long arg)104 static void br_tcn_timer_expired(unsigned long arg)
105 {
106 struct net_bridge *br = (struct net_bridge *) arg;
107
108 br_debug(br, "tcn timer expired\n");
109 spin_lock(&br->lock);
110 if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) {
111 br_transmit_tcn(br);
112
113 mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time);
114 }
115 spin_unlock(&br->lock);
116 }
117
br_topology_change_timer_expired(unsigned long arg)118 static void br_topology_change_timer_expired(unsigned long arg)
119 {
120 struct net_bridge *br = (struct net_bridge *) arg;
121
122 br_debug(br, "topo change timer expired\n");
123 spin_lock(&br->lock);
124 br->topology_change_detected = 0;
125 br->topology_change = 0;
126 spin_unlock(&br->lock);
127 }
128
br_hold_timer_expired(unsigned long arg)129 static void br_hold_timer_expired(unsigned long arg)
130 {
131 struct net_bridge_port *p = (struct net_bridge_port *) arg;
132
133 br_debug(p->br, "port %u(%s) hold timer expired\n",
134 (unsigned) p->port_no, p->dev->name);
135
136 spin_lock(&p->br->lock);
137 if (p->config_pending)
138 br_transmit_config(p);
139 spin_unlock(&p->br->lock);
140 }
141
br_stp_timer_init(struct net_bridge * br)142 void br_stp_timer_init(struct net_bridge *br)
143 {
144 setup_timer(&br->hello_timer, br_hello_timer_expired,
145 (unsigned long) br);
146
147 setup_timer(&br->tcn_timer, br_tcn_timer_expired,
148 (unsigned long) br);
149
150 setup_timer(&br->topology_change_timer,
151 br_topology_change_timer_expired,
152 (unsigned long) br);
153
154 setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br);
155 }
156
br_stp_port_timer_init(struct net_bridge_port * p)157 void br_stp_port_timer_init(struct net_bridge_port *p)
158 {
159 setup_timer(&p->message_age_timer, br_message_age_timer_expired,
160 (unsigned long) p);
161
162 setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired,
163 (unsigned long) p);
164
165 setup_timer(&p->hold_timer, br_hold_timer_expired,
166 (unsigned long) p);
167 }
168
169 /* Report ticks left (in USER_HZ) used for API */
br_timer_value(const struct timer_list * timer)170 unsigned long br_timer_value(const struct timer_list *timer)
171 {
172 return timer_pending(timer)
173 ? jiffies_to_clock_t(timer->expires - jiffies) : 0;
174 }
175