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
  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 }