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 int) 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 int) p->port_no, p->dev->name); 88 spin_lock(&br->lock); 89 if (p->state == BR_STATE_LISTENING) { 90 br_set_state(p, BR_STATE_LEARNING); 91 mod_timer(&p->forward_delay_timer, 92 jiffies + br->forward_delay); 93 } else if (p->state == BR_STATE_LEARNING) { 94 br_set_state(p, 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 br_ifinfo_notify(RTM_NEWLINK, p); 101 spin_unlock(&br->lock); 102 } 103 104 static void br_tcn_timer_expired(unsigned long arg) 105 { 106 struct net_bridge *br = (struct net_bridge *) arg; 107 108 br_debug(br, "tcn timer expired\n"); 109 spin_lock(&br->lock); 110 if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) { 111 br_transmit_tcn(br); 112 113 mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time); 114 } 115 spin_unlock(&br->lock); 116 } 117 118 static void br_topology_change_timer_expired(unsigned long arg) 119 { 120 struct net_bridge *br = (struct net_bridge *) arg; 121 122 br_debug(br, "topo change timer expired\n"); 123 spin_lock(&br->lock); 124 br->topology_change_detected = 0; 125 br->topology_change = 0; 126 spin_unlock(&br->lock); 127 } 128 129 static void br_hold_timer_expired(unsigned long arg) 130 { 131 struct net_bridge_port *p = (struct net_bridge_port *) arg; 132 133 br_debug(p->br, "port %u(%s) hold timer expired\n", 134 (unsigned int) p->port_no, p->dev->name); 135 136 spin_lock(&p->br->lock); 137 if (p->config_pending) 138 br_transmit_config(p); 139 spin_unlock(&p->br->lock); 140 } 141 142 void br_stp_timer_init(struct net_bridge *br) 143 { 144 setup_timer(&br->hello_timer, br_hello_timer_expired, 145 (unsigned long) br); 146 147 setup_timer(&br->tcn_timer, br_tcn_timer_expired, 148 (unsigned long) br); 149 150 setup_timer(&br->topology_change_timer, 151 br_topology_change_timer_expired, 152 (unsigned long) br); 153 154 setup_timer(&br->gc_timer, br_fdb_cleanup, (unsigned long) br); 155 } 156 157 void br_stp_port_timer_init(struct net_bridge_port *p) 158 { 159 setup_timer(&p->message_age_timer, br_message_age_timer_expired, 160 (unsigned long) p); 161 162 setup_timer(&p->forward_delay_timer, br_forward_delay_timer_expired, 163 (unsigned long) p); 164 165 setup_timer(&p->hold_timer, br_hold_timer_expired, 166 (unsigned long) p); 167 } 168 169 /* Report ticks left (in USER_HZ) used for API */ 170 unsigned long br_timer_value(const struct timer_list *timer) 171 { 172 return timer_pending(timer) 173 ? jiffies_delta_to_clock_t(timer->expires - jiffies) : 0; 174 } 175