1 /* 2 * Spanning tree protocol; interface code 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 davem Exp $ 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/smp_lock.h> 18 #include <linux/etherdevice.h> 19 20 #include "br_private.h" 21 #include "br_private_stp.h" 22 23 24 /* Port id is composed of priority and port number. 25 * NB: least significant bits of priority are dropped to 26 * make room for more ports. 27 */ 28 static inline port_id br_make_port_id(__u8 priority, __u16 port_no) 29 { 30 return ((u16)priority << BR_PORT_BITS) 31 | (port_no & ((1<<BR_PORT_BITS)-1)); 32 } 33 34 /* called under bridge lock */ 35 void br_init_port(struct net_bridge_port *p) 36 { 37 p->port_id = br_make_port_id(p->priority, p->port_no); 38 br_become_designated_port(p); 39 p->state = BR_STATE_BLOCKING; 40 p->topology_change_ack = 0; 41 p->config_pending = 0; 42 43 br_stp_port_timer_init(p); 44 } 45 46 /* called under bridge lock */ 47 void br_stp_enable_bridge(struct net_bridge *br) 48 { 49 struct net_bridge_port *p; 50 51 spin_lock_bh(&br->lock); 52 mod_timer(&br->hello_timer, jiffies + br->hello_time); 53 mod_timer(&br->gc_timer, jiffies + HZ/10); 54 55 br_config_bpdu_generation(br); 56 57 list_for_each_entry(p, &br->port_list, list) { 58 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev)) 59 br_stp_enable_port(p); 60 61 } 62 spin_unlock_bh(&br->lock); 63 } 64 65 /* NO locks held */ 66 void br_stp_disable_bridge(struct net_bridge *br) 67 { 68 struct net_bridge_port *p; 69 70 spin_lock(&br->lock); 71 list_for_each_entry(p, &br->port_list, list) { 72 if (p->state != BR_STATE_DISABLED) 73 br_stp_disable_port(p); 74 75 } 76 77 br->topology_change = 0; 78 br->topology_change_detected = 0; 79 spin_unlock(&br->lock); 80 81 del_timer_sync(&br->hello_timer); 82 del_timer_sync(&br->topology_change_timer); 83 del_timer_sync(&br->tcn_timer); 84 del_timer_sync(&br->gc_timer); 85 } 86 87 /* called under bridge lock */ 88 void br_stp_enable_port(struct net_bridge_port *p) 89 { 90 br_init_port(p); 91 br_port_state_selection(p->br); 92 } 93 94 /* called under bridge lock */ 95 void br_stp_disable_port(struct net_bridge_port *p) 96 { 97 struct net_bridge *br; 98 int wasroot; 99 100 br = p->br; 101 printk(KERN_INFO "%s: port %i(%s) entering %s state\n", 102 br->dev->name, p->port_no, p->dev->name, "disabled"); 103 104 wasroot = br_is_root_bridge(br); 105 br_become_designated_port(p); 106 p->state = BR_STATE_DISABLED; 107 p->topology_change_ack = 0; 108 p->config_pending = 0; 109 110 del_timer(&p->message_age_timer); 111 del_timer(&p->forward_delay_timer); 112 del_timer(&p->hold_timer); 113 114 br_configuration_update(br); 115 116 br_port_state_selection(br); 117 118 if (br_is_root_bridge(br) && !wasroot) 119 br_become_root_bridge(br); 120 } 121 122 /* called under bridge lock */ 123 static void br_stp_change_bridge_id(struct net_bridge *br, 124 const unsigned char *addr) 125 { 126 unsigned char oldaddr[6]; 127 struct net_bridge_port *p; 128 int wasroot; 129 130 wasroot = br_is_root_bridge(br); 131 132 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); 133 memcpy(br->bridge_id.addr, addr, ETH_ALEN); 134 memcpy(br->dev->dev_addr, addr, ETH_ALEN); 135 136 list_for_each_entry(p, &br->port_list, list) { 137 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr)) 138 memcpy(p->designated_bridge.addr, addr, ETH_ALEN); 139 140 if (!compare_ether_addr(p->designated_root.addr, oldaddr)) 141 memcpy(p->designated_root.addr, addr, ETH_ALEN); 142 143 } 144 145 br_configuration_update(br); 146 br_port_state_selection(br); 147 if (br_is_root_bridge(br) && !wasroot) 148 br_become_root_bridge(br); 149 } 150 151 static const unsigned char br_mac_zero[6]; 152 153 /* called under bridge lock */ 154 void br_stp_recalculate_bridge_id(struct net_bridge *br) 155 { 156 const unsigned char *addr = br_mac_zero; 157 struct net_bridge_port *p; 158 159 list_for_each_entry(p, &br->port_list, list) { 160 if (addr == br_mac_zero || 161 compare_ether_addr(p->dev->dev_addr, addr) < 0) 162 addr = p->dev->dev_addr; 163 164 } 165 166 if (compare_ether_addr(br->bridge_id.addr, addr)) 167 br_stp_change_bridge_id(br, addr); 168 } 169 170 /* called under bridge lock */ 171 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) 172 { 173 struct net_bridge_port *p; 174 int wasroot; 175 176 wasroot = br_is_root_bridge(br); 177 178 list_for_each_entry(p, &br->port_list, list) { 179 if (p->state != BR_STATE_DISABLED && 180 br_is_designated_port(p)) { 181 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF; 182 p->designated_bridge.prio[1] = newprio & 0xFF; 183 } 184 185 } 186 187 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF; 188 br->bridge_id.prio[1] = newprio & 0xFF; 189 br_configuration_update(br); 190 br_port_state_selection(br); 191 if (br_is_root_bridge(br) && !wasroot) 192 br_become_root_bridge(br); 193 } 194 195 /* called under bridge lock */ 196 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio) 197 { 198 port_id new_port_id = br_make_port_id(newprio, p->port_no); 199 200 if (br_is_designated_port(p)) 201 p->designated_port = new_port_id; 202 203 p->port_id = new_port_id; 204 p->priority = newprio; 205 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) && 206 p->port_id < p->designated_port) { 207 br_become_designated_port(p); 208 br_port_state_selection(p->br); 209 } 210 } 211 212 /* called under bridge lock */ 213 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost) 214 { 215 p->path_cost = path_cost; 216 br_configuration_update(p->br); 217 br_port_state_selection(p->br); 218 } 219 220 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id) 221 { 222 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n", 223 id->prio[0], id->prio[1], 224 id->addr[0], id->addr[1], id->addr[2], 225 id->addr[3], id->addr[4], id->addr[5]); 226 } 227