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 br_log_state(p); 102 rcu_read_lock(); 103 br_ifinfo_notify(RTM_NEWLINK, p); 104 rcu_read_unlock(); 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 br_debug(br, "tcn timer expired\n"); 113 spin_lock(&br->lock); 114 if (!br_is_root_bridge(br) && (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 br_debug(br, "topo change timer expired\n"); 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 br_debug(p->br, "port %u(%s) hold timer expired\n", 138 (unsigned int) 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_delta_to_clock_t(timer->expires - jiffies) : 0; 178 } 179