Merge branch 'linus' into stackprotector
[linux-2.6] / net / bridge / br_stp_timer.c
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 */
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
34 static void br_hello_timer_expired(unsigned long arg)
35 {
36         struct net_bridge *br = (struct net_bridge *)arg;
37
38         pr_debug("%s: hello timer expired\n", br->dev->name);
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
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
59         pr_info("%s: neighbor %.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x lost on port %d(%s)\n",
60                 br->dev->name,
61                 id->prio[0], id->prio[1],
62                 id->addr[0], id->addr[1], id->addr[2],
63                 id->addr[3], id->addr[4], id->addr[5],
64                 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         spin_lock(&br->lock);
72         if (p->state == BR_STATE_DISABLED)
73                 goto unlock;
74         was_root = br_is_root_bridge(br);
75
76         br_become_designated_port(p);
77         br_configuration_update(br);
78         br_port_state_selection(br);
79         if (br_is_root_bridge(br) && !was_root)
80                 br_become_root_bridge(br);
81  unlock:
82         spin_unlock(&br->lock);
83 }
84
85 static void br_forward_delay_timer_expired(unsigned long arg)
86 {
87         struct net_bridge_port *p = (struct net_bridge_port *) arg;
88         struct net_bridge *br = p->br;
89
90         pr_debug("%s: %d(%s) forward delay timer\n",
91                  br->dev->name, p->port_no, p->dev->name);
92         spin_lock(&br->lock);
93         if (p->state == BR_STATE_LISTENING) {
94                 p->state = BR_STATE_LEARNING;
95                 mod_timer(&p->forward_delay_timer,
96                           jiffies + br->forward_delay);
97         } else if (p->state == BR_STATE_LEARNING) {
98                 p->state = BR_STATE_FORWARDING;
99                 if (br_is_designated_for_some_port(br))
100                         br_topology_change_detection(br);
101         }
102         br_log_state(p);
103         spin_unlock(&br->lock);
104 }
105
106 static void br_tcn_timer_expired(unsigned long arg)
107 {
108         struct net_bridge *br = (struct net_bridge *) arg;
109
110         pr_debug("%s: tcn timer expired\n", br->dev->name);
111         spin_lock(&br->lock);
112         if (br->dev->flags & IFF_UP) {
113                 br_transmit_tcn(br);
114
115                 mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time);
116         }
117         spin_unlock(&br->lock);
118 }
119
120 static void br_topology_change_timer_expired(unsigned long arg)
121 {
122         struct net_bridge *br = (struct net_bridge *) arg;
123
124         pr_debug("%s: topo change timer expired\n", br->dev->name);
125         spin_lock(&br->lock);
126         br->topology_change_detected = 0;
127         br->topology_change = 0;
128         spin_unlock(&br->lock);
129 }
130
131 static void br_hold_timer_expired(unsigned long arg)
132 {
133         struct net_bridge_port *p = (struct net_bridge_port *) arg;
134
135         pr_debug("%s: %d(%s) hold timer expired\n",
136                  p->br->dev->name,  p->port_no, p->dev->name);
137
138         spin_lock(&p->br->lock);
139         if (p->config_pending)
140                 br_transmit_config(p);
141         spin_unlock(&p->br->lock);
142 }
143
144 void br_stp_timer_init(struct net_bridge *br)
145 {
146         setup_timer(&br->hello_timer, br_hello_timer_expired,
147                       (unsigned long) br);
148
149         setup_timer(&br->tcn_timer, br_tcn_timer_expired,
150                       (unsigned long) br);
151
152         setup_timer(&br->topology_change_timer,
153                       br_topology_change_timer_expired,
154                       (unsigned long) br);
155
156         setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br);
157 }
158
159 void br_stp_port_timer_init(struct net_bridge_port *p)
160 {
161         setup_timer(&p->message_age_timer, br_message_age_timer_expired,
162                       (unsigned long) p);
163
164         setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired,
165                       (unsigned long) p);
166
167         setup_timer(&p->hold_timer, br_hold_timer_expired,
168                       (unsigned long) p);
169 }
170
171 /* Report ticks left (in USER_HZ) used for API */
172 unsigned long br_timer_value(const struct timer_list *timer)
173 {
174         return timer_pending(timer)
175                 ? jiffies_to_clock_t(timer->expires - jiffies) : 0;
176 }