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/*

 *      Spanning tree protocol; timer-related code

 *      Linux ethernet bridge

 *

 *      Authors:

 *      Lennert Buytenhek               <buytenh@gnu.org>

 *

 *      $Id: br_stp_timer.c,v 1.1.1.1 2004-04-15 01:16:26 phoenix Exp $

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 */

#include <linux/kernel.h>

#include <linux/if_bridge.h>

#include <linux/smp_lock.h>

#include <asm/uaccess.h>

#include "br_private.h"

#include "br_private_stp.h"

static void dump_bridge_id(bridge_id *id)

{

        printk("%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", id->prio[0],

               id->prio[1], id->addr[0], id->addr[1], id->addr[2], id->addr[3],

               id->addr[4], id->addr[5]);

}

/* called under bridge lock */

static int br_is_designated_for_some_port(struct net_bridge *br)

{

        struct net_bridge_port *p;

        p = br->port_list;

        while (p != NULL) {

                if (p->state != BR_STATE_DISABLED &&

                    !memcmp(&p->designated_bridge, &br->bridge_id, 8))

                        return 1;

                p = p->next;

        }

        return 0;

}

/* called under bridge lock */

static void br_hello_timer_expired(struct net_bridge *br)

{

        br_config_bpdu_generation(br);

        br_timer_set(&br->hello_timer, jiffies);

}

/* called under bridge lock */

static void br_message_age_timer_expired(struct net_bridge_port *p)

{

        struct net_bridge *br;

        int was_root;

        br = p->br;

        printk(KERN_INFO "%s: ", br->dev.name);

        printk("neighbour ");

        dump_bridge_id(&p->designated_bridge);

        printk(" lost on port %i(%s)\n", p->port_no, p->dev->name);

        /*

         * According to the spec, the message age timer cannot be

         * running when we are the root bridge. So..  this was_root

         * check is redundant. I'm leaving it in for now, though.

         */

        was_root = br_is_root_bridge(br);

        br_become_designated_port(p);

        br_configuration_update(br);

        br_port_state_selection(br);

        if (br_is_root_bridge(br) && !was_root)

                br_become_root_bridge(br);

}

/* called under bridge lock */

static void br_forward_delay_timer_expired(struct net_bridge_port *p)

{

        if (p->state == BR_STATE_LISTENING) {

                printk(KERN_INFO "%s: port %i(%s) entering %s state\n",

                       p->br->dev.name, p->port_no, p->dev->name, "learning");

                p->state = BR_STATE_LEARNING;

                br_timer_set(&p->forward_delay_timer, jiffies);

        } else if (p->state == BR_STATE_LEARNING) {

                printk(KERN_INFO "%s: port %i(%s) entering %s state\n",

                       p->br->dev.name, p->port_no, p->dev->name, "forwarding");

                p->state = BR_STATE_FORWARDING;

                if (br_is_designated_for_some_port(p->br))

                        br_topology_change_detection(p->br);

        }

}

/* called under bridge lock */

static void br_tcn_timer_expired(struct net_bridge *br)

{

        printk(KERN_INFO "%s: retransmitting tcn bpdu\n", br->dev.name);

        br_transmit_tcn(br);

        br_timer_set(&br->tcn_timer, jiffies);

}

/* called under bridge lock */

static void br_topology_change_timer_expired(struct net_bridge *br)

{

        br->topology_change_detected = 0;

        br->topology_change = 0;

}

/* called under bridge lock */

static void br_hold_timer_expired(struct net_bridge_port *p)

{

        if (p->config_pending)

                br_transmit_config(p);

}

/* called under bridge lock */

static void br_check_port_timers(struct net_bridge_port *p)

{

        if (br_timer_has_expired(&p->message_age_timer, p->br->max_age)) {

                br_timer_clear(&p->message_age_timer);

                br_message_age_timer_expired(p);

        }

        if (br_timer_has_expired(&p->forward_delay_timer, p->br->forward_delay)) {

                br_timer_clear(&p->forward_delay_timer);

                br_forward_delay_timer_expired(p);

        }

        if (br_timer_has_expired(&p->hold_timer, BR_HOLD_TIME)) {

                br_timer_clear(&p->hold_timer);

                br_hold_timer_expired(p);

        }

}

/* called under bridge lock */

static void br_check_timers(struct net_bridge *br)

{

        struct net_bridge_port *p;

        if (br_timer_has_expired(&br->gc_timer, br->gc_interval)) {

                br_timer_set(&br->gc_timer, jiffies);

                br_fdb_cleanup(br);

        }

        if (br_timer_has_expired(&br->hello_timer, br->hello_time)) {

                br_timer_clear(&br->hello_timer);

                br_hello_timer_expired(br);

        }

        if (br_timer_has_expired(&br->tcn_timer, br->bridge_hello_time)) {

                br_timer_clear(&br->tcn_timer);

                br_tcn_timer_expired(br);

        }

        if (br_timer_has_expired(&br->topology_change_timer, br->bridge_forward_delay + br->bridge_max_age)) {

                br_timer_clear(&br->topology_change_timer);

                br_topology_change_timer_expired(br);

        }

        p = br->port_list;

        while (p != NULL) {

                if (p->state != BR_STATE_DISABLED)

                        br_check_port_timers(p);

                p = p->next;

        }

}

void br_tick(unsigned long __data)

{

        struct net_bridge *br = (struct net_bridge *)__data;

        read_lock(&br->lock);

        br_check_timers(br);

        read_unlock(&br->lock);

        br->tick.expires = jiffies + 1;

        add_timer(&br->tick);

}