| 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 | 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 | if (br->stp_enabled != BR_USER_STP) |
| 44 | mod_timer(&br->hello_timer, |
| 45 | 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 | br_info(br, "port %u(%s) neighbor %.2x%.2x.%pM lost\n", |
| 61 | (unsigned int) p->port_no, p->dev->name, |
| 62 | id->prio[0], id->prio[1], &id->addr); |
| 63 | |
| 64 | /* |
| 65 | * According to the spec, the message age timer cannot be |
| 66 | * running when we are the root bridge. So.. this was_root |
| 67 | * check is redundant. I'm leaving it in for now, though. |
| 68 | */ |
| 69 | spin_lock(&br->lock); |
| 70 | if (p->state == BR_STATE_DISABLED) |
| 71 | goto unlock; |
| 72 | was_root = br_is_root_bridge(br); |
| 73 | |
| 74 | br_become_designated_port(p); |
| 75 | br_configuration_update(br); |
| 76 | br_port_state_selection(br); |
| 77 | if (br_is_root_bridge(br) && !was_root) |
| 78 | br_become_root_bridge(br); |
| 79 | unlock: |
| 80 | spin_unlock(&br->lock); |
| 81 | } |
| 82 | |
| 83 | static void br_forward_delay_timer_expired(unsigned long arg) |
| 84 | { |
| 85 | struct net_bridge_port *p = (struct net_bridge_port *) arg; |
| 86 | struct net_bridge *br = p->br; |
| 87 | |
| 88 | br_debug(br, "port %u(%s) forward delay timer\n", |
| 89 | (unsigned int) p->port_no, p->dev->name); |
| 90 | spin_lock(&br->lock); |
| 91 | if (p->state == BR_STATE_LISTENING) { |
| 92 | br_set_state(p, BR_STATE_LEARNING); |
| 93 | mod_timer(&p->forward_delay_timer, |
| 94 | jiffies + br->forward_delay); |
| 95 | } else if (p->state == BR_STATE_LEARNING) { |
| 96 | br_set_state(p, BR_STATE_FORWARDING); |
| 97 | if (br_is_designated_for_some_port(br)) |
| 98 | br_topology_change_detection(br); |
| 99 | netif_carrier_on(br->dev); |
| 100 | } |
| 101 | rcu_read_lock(); |
| 102 | br_ifinfo_notify(RTM_NEWLINK, p); |
| 103 | rcu_read_unlock(); |
| 104 | spin_unlock(&br->lock); |
| 105 | } |
| 106 | |
| 107 | static void br_tcn_timer_expired(unsigned long arg) |
| 108 | { |
| 109 | struct net_bridge *br = (struct net_bridge *) arg; |
| 110 | |
| 111 | br_debug(br, "tcn timer expired\n"); |
| 112 | spin_lock(&br->lock); |
| 113 | if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) { |
| 114 | br_transmit_tcn(br); |
| 115 | |
| 116 | mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time); |
| 117 | } |
| 118 | spin_unlock(&br->lock); |
| 119 | } |
| 120 | |
| 121 | static void br_topology_change_timer_expired(unsigned long arg) |
| 122 | { |
| 123 | struct net_bridge *br = (struct net_bridge *) arg; |
| 124 | |
| 125 | br_debug(br, "topo change timer expired\n"); |
| 126 | spin_lock(&br->lock); |
| 127 | br->topology_change_detected = 0; |
| 128 | br->topology_change = 0; |
| 129 | spin_unlock(&br->lock); |
| 130 | } |
| 131 | |
| 132 | static void br_hold_timer_expired(unsigned long arg) |
| 133 | { |
| 134 | struct net_bridge_port *p = (struct net_bridge_port *) arg; |
| 135 | |
| 136 | br_debug(p->br, "port %u(%s) hold timer expired\n", |
| 137 | (unsigned int) p->port_no, p->dev->name); |
| 138 | |
| 139 | spin_lock(&p->br->lock); |
| 140 | if (p->config_pending) |
| 141 | br_transmit_config(p); |
| 142 | spin_unlock(&p->br->lock); |
| 143 | } |
| 144 | |
| 145 | void br_stp_timer_init(struct net_bridge *br) |
| 146 | { |
| 147 | setup_timer(&br->hello_timer, br_hello_timer_expired, |
| 148 | (unsigned long) br); |
| 149 | |
| 150 | setup_timer(&br->tcn_timer, br_tcn_timer_expired, |
| 151 | (unsigned long) br); |
| 152 | |
| 153 | setup_timer(&br->topology_change_timer, |
| 154 | br_topology_change_timer_expired, |
| 155 | (unsigned long) br); |
| 156 | |
| 157 | setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br); |
| 158 | } |
| 159 | |
| 160 | void br_stp_port_timer_init(struct net_bridge_port *p) |
| 161 | { |
| 162 | setup_timer(&p->message_age_timer, br_message_age_timer_expired, |
| 163 | (unsigned long) p); |
| 164 | |
| 165 | setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired, |
| 166 | (unsigned long) p); |
| 167 | |
| 168 | setup_timer(&p->hold_timer, br_hold_timer_expired, |
| 169 | (unsigned long) p); |
| 170 | } |
| 171 | |
| 172 | /* Report ticks left (in USER_HZ) used for API */ |
| 173 | unsigned long br_timer_value(const struct timer_list *timer) |
| 174 | { |
| 175 | return timer_pending(timer) |
| 176 | ? jiffies_delta_to_clock_t(timer->expires - jiffies) : 0; |
| 177 | } |