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  *      $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 */
  24 static 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
  37 static 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_bh(&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_bh(&br->lock);
  49 }
  50
  51 static 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_bh(&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_bh(&br->lock);
  86 }
  87
  88 static 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_bh(&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_bh(&br->lock);
 107 }
 108
 109 static 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_bh(&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_bh(&br->lock);
 121 }
 122
 123 static 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_bh(&br->lock);
 129         br->topology_change_detected = 0;
 130         br->topology_change = 0;
 131         spin_unlock_bh(&br->lock);
 132 }
 133
 134 static 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_bh(&p->br->lock);
 142         if (p->config_pending)
 143                 br_transmit_config(p);
 144         spin_unlock_bh(&p->br->lock);
 145 }
 146
 147 static 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
 156 void 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
 171 void 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 */
 184 unsigned 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 }