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 mod_timer(&br->hello_timer, round_jiffies(jiffies + br->hello_time)); 44 } 45 spin_unlock(&br->lock); 46 } 47 48 static void br_message_age_timer_expired(unsigned long arg) 49 { 50 struct net_bridge_port *p = (struct net_bridge_port *) arg; 51 struct net_bridge *br = p->br; 52 const bridge_id *id = &p->designated_bridge; 53 int was_root; 54 55 if (p->state == BR_STATE_DISABLED) 56 return; 57 58 br_info(br, "port %u(%s) neighbor %.2x%.2x.%pM lost\n", 59 (unsigned) p->port_no, p->dev->name, 60 id->prio[0], id->prio[1], &id->addr); 61 62 /* 63 * According to the spec, the message age timer cannot be 64 * running when we are the root bridge. So.. this was_root 65 * check is redundant. I'm leaving it in for now, though. 66 */ 67 spin_lock(&br->lock); 68 if (p->state == BR_STATE_DISABLED) 69 goto unlock; 70 was_root = br_is_root_bridge(br); 71 72 br_become_designated_port(p); 73 br_configuration_update(br); 74 br_port_state_selection(br); 75 if (br_is_root_bridge(br) && !was_root) 76 br_become_root_bridge(br); 77 unlock: 78 spin_unlock(&br->lock); 79 } 80 81 static void br_forward_delay_timer_expired(unsigned long arg) 82 { 83 struct net_bridge_port *p = (struct net_bridge_port *) arg; 84 struct net_bridge *br = p->br; 85 86 br_debug(br, "port %u(%s) forward delay timer\n", 87 (unsigned) p->port_no, p->dev->name); 88 spin_lock(&br->lock); 89 if (p->state == BR_STATE_LISTENING) { 90 p->state = BR_STATE_LEARNING; 91 mod_timer(&p->forward_delay_timer, 92 jiffies + br->forward_delay); 93 } else if (p->state == BR_STATE_LEARNING) { 94 p->state = BR_STATE_FORWARDING; 95 if (br_is_designated_for_some_port(br)) 96 br_topology_change_detection(br); 97 netif_carrier_on(br->dev); 98 } 99 br_log_state(p); 100 spin_unlock(&br->lock); 101 } 102 103 static void br_tcn_timer_expired(unsigned long arg) 104 { 105 struct net_bridge *br = (struct net_bridge *) arg; 106 107 br_debug(br, "tcn timer expired\n"); 108 spin_lock(&br->lock); 109 if (br->dev->flags & IFF_UP) { 110 br_transmit_tcn(br); 111 112 mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time); 113 } 114 spin_unlock(&br->lock); 115 } 116 117 static void br_topology_change_timer_expired(unsigned long arg) 118 { 119 struct net_bridge *br = (struct net_bridge *) arg; 120 121 br_debug(br, "topo change timer expired\n"); 122 spin_lock(&br->lock); 123 br->topology_change_detected = 0; 124 br->topology_change = 0; 125 spin_unlock(&br->lock); 126 } 127 128 static void br_hold_timer_expired(unsigned long arg) 129 { 130 struct net_bridge_port *p = (struct net_bridge_port *) arg; 131 132 br_debug(p->br, "port %u(%s) hold timer expired\n", 133 (unsigned) p->port_no, p->dev->name); 134 135 spin_lock(&p->br->lock); 136 if (p->config_pending) 137 br_transmit_config(p); 138 spin_unlock(&p->br->lock); 139 } 140 141 void br_stp_timer_init(struct net_bridge *br) 142 { 143 setup_timer(&br->hello_timer, br_hello_timer_expired, 144 (unsigned long) br); 145 146 setup_timer(&br->tcn_timer, br_tcn_timer_expired, 147 (unsigned long) br); 148 149 setup_timer(&br->topology_change_timer, 150 br_topology_change_timer_expired, 151 (unsigned long) br); 152 153 setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br); 154 } 155 156 void br_stp_port_timer_init(struct net_bridge_port *p) 157 { 158 setup_timer(&p->message_age_timer, br_message_age_timer_expired, 159 (unsigned long) p); 160 161 setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired, 162 (unsigned long) p); 163 164 setup_timer(&p->hold_timer, br_hold_timer_expired, 165 (unsigned long) p); 166 } 167 168 /* Report ticks left (in USER_HZ) used for API */ 169 unsigned long br_timer_value(const struct timer_list *timer) 170 { 171 return timer_pending(timer) 172 ? jiffies_to_clock_t(timer->expires - jiffies) : 0; 173 } 174