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 pr_debug("%s: hello timer expired\n", br->dev->name); 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 59 pr_info("%s: neighbor %.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x lost on port %d(%s)\n", 60 br->dev->name, 61 id->prio[0], id->prio[1], 62 id->addr[0], id->addr[1], id->addr[2], 63 id->addr[3], id->addr[4], id->addr[5], 64 p->port_no, p->dev->name); 65 66 /* 67 * According to the spec, the message age timer cannot be 68 * running when we are the root bridge. So.. this was_root 69 * check is redundant. I'm leaving it in for now, though. 70 */ 71 spin_lock(&br->lock); 72 if (p->state == BR_STATE_DISABLED) 73 goto unlock; 74 was_root = br_is_root_bridge(br); 75 76 br_become_designated_port(p); 77 br_configuration_update(br); 78 br_port_state_selection(br); 79 if (br_is_root_bridge(br) && !was_root) 80 br_become_root_bridge(br); 81 unlock: 82 spin_unlock(&br->lock); 83 } 84 85 static void br_forward_delay_timer_expired(unsigned long arg) 86 { 87 struct net_bridge_port *p = (struct net_bridge_port *) arg; 88 struct net_bridge *br = p->br; 89 90 pr_debug("%s: %d(%s) forward delay timer\n", 91 br->dev->name, p->port_no, p->dev->name); 92 spin_lock(&br->lock); 93 if (p->state == BR_STATE_LISTENING) { 94 p->state = BR_STATE_LEARNING; 95 mod_timer(&p->forward_delay_timer, 96 jiffies + br->forward_delay); 97 } else if (p->state == BR_STATE_LEARNING) { 98 p->state = BR_STATE_FORWARDING; 99 if (br_is_designated_for_some_port(br)) 100 br_topology_change_detection(br); 101 } 102 br_log_state(p); 103 spin_unlock(&br->lock); 104 } 105 106 static void br_tcn_timer_expired(unsigned long arg) 107 { 108 struct net_bridge *br = (struct net_bridge *) arg; 109 110 pr_debug("%s: tcn timer expired\n", br->dev->name); 111 spin_lock(&br->lock); 112 if (br->dev->flags & IFF_UP) { 113 br_transmit_tcn(br); 114 115 mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time); 116 } 117 spin_unlock(&br->lock); 118 } 119 120 static void br_topology_change_timer_expired(unsigned long arg) 121 { 122 struct net_bridge *br = (struct net_bridge *) arg; 123 124 pr_debug("%s: topo change timer expired\n", br->dev->name); 125 spin_lock(&br->lock); 126 br->topology_change_detected = 0; 127 br->topology_change = 0; 128 spin_unlock(&br->lock); 129 } 130 131 static void br_hold_timer_expired(unsigned long arg) 132 { 133 struct net_bridge_port *p = (struct net_bridge_port *) arg; 134 135 pr_debug("%s: %d(%s) hold timer expired\n", 136 p->br->dev->name, p->port_no, p->dev->name); 137 138 spin_lock(&p->br->lock); 139 if (p->config_pending) 140 br_transmit_config(p); 141 spin_unlock(&p->br->lock); 142 } 143 144 void br_stp_timer_init(struct net_bridge *br) 145 { 146 setup_timer(&br->hello_timer, br_hello_timer_expired, 147 (unsigned long) br); 148 149 setup_timer(&br->tcn_timer, br_tcn_timer_expired, 150 (unsigned long) br); 151 152 setup_timer(&br->topology_change_timer, 153 br_topology_change_timer_expired, 154 (unsigned long) br); 155 156 setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br); 157 } 158 159 void br_stp_port_timer_init(struct net_bridge_port *p) 160 { 161 setup_timer(&p->message_age_timer, br_message_age_timer_expired, 162 (unsigned long) p); 163 164 setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired, 165 (unsigned long) p); 166 167 setup_timer(&p->hold_timer, br_hold_timer_expired, 168 (unsigned long) p); 169 } 170 171 /* Report ticks left (in USER_HZ) used for API */ 172 unsigned long br_timer_value(const struct timer_list *timer) 173 { 174 return timer_pending(timer) 175 ? jiffies_to_clock_t(timer->expires - jiffies) : 0; 176 } 177