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 #include <linux/rtnetlink.h> 20 21 #include "br_private.h" 22 #include "br_private_stp.h" 23 24 25 /* Port id is composed of priority and port number. 26 * NB: least significant bits of priority are dropped to 27 * make room for more ports. 28 */ 29 static inline port_id br_make_port_id(__u8 priority, __u16 port_no) 30 { 31 return ((u16)priority << BR_PORT_BITS) 32 | (port_no & ((1<<BR_PORT_BITS)-1)); 33 } 34 35 /* called under bridge lock */ 36 void br_init_port(struct net_bridge_port *p) 37 { 38 p->port_id = br_make_port_id(p->priority, p->port_no); 39 br_become_designated_port(p); 40 p->state = BR_STATE_BLOCKING; 41 p->topology_change_ack = 0; 42 p->config_pending = 0; 43 } 44 45 /* called under bridge lock */ 46 void br_stp_enable_bridge(struct net_bridge *br) 47 { 48 struct net_bridge_port *p; 49 50 spin_lock_bh(&br->lock); 51 mod_timer(&br->hello_timer, jiffies + br->hello_time); 52 mod_timer(&br->gc_timer, jiffies + HZ/10); 53 54 br_config_bpdu_generation(br); 55 56 list_for_each_entry(p, &br->port_list, list) { 57 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev)) 58 br_stp_enable_port(p); 59 60 } 61 spin_unlock_bh(&br->lock); 62 } 63 64 /* NO locks held */ 65 void br_stp_disable_bridge(struct net_bridge *br) 66 { 67 struct net_bridge_port *p; 68 69 spin_lock_bh(&br->lock); 70 list_for_each_entry(p, &br->port_list, list) { 71 if (p->state != BR_STATE_DISABLED) 72 br_stp_disable_port(p); 73 74 } 75 76 br->topology_change = 0; 77 br->topology_change_detected = 0; 78 spin_unlock_bh(&br->lock); 79 80 del_timer_sync(&br->hello_timer); 81 del_timer_sync(&br->topology_change_timer); 82 del_timer_sync(&br->tcn_timer); 83 del_timer_sync(&br->gc_timer); 84 } 85 86 /* called under bridge lock */ 87 void br_stp_enable_port(struct net_bridge_port *p) 88 { 89 br_init_port(p); 90 br_ifinfo_notify(RTM_NEWLINK, 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 br_ifinfo_notify(RTM_DELLINK, p); 105 106 wasroot = br_is_root_bridge(br); 107 br_become_designated_port(p); 108 p->state = BR_STATE_DISABLED; 109 p->topology_change_ack = 0; 110 p->config_pending = 0; 111 112 del_timer(&p->message_age_timer); 113 del_timer(&p->forward_delay_timer); 114 del_timer(&p->hold_timer); 115 116 br_configuration_update(br); 117 118 br_port_state_selection(br); 119 120 if (br_is_root_bridge(br) && !wasroot) 121 br_become_root_bridge(br); 122 } 123 124 /* called under bridge lock */ 125 void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr) 126 { 127 unsigned char oldaddr[6]; 128 struct net_bridge_port *p; 129 int wasroot; 130 131 wasroot = br_is_root_bridge(br); 132 133 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); 134 memcpy(br->bridge_id.addr, addr, ETH_ALEN); 135 memcpy(br->dev->dev_addr, addr, ETH_ALEN); 136 137 list_for_each_entry(p, &br->port_list, list) { 138 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr)) 139 memcpy(p->designated_bridge.addr, addr, ETH_ALEN); 140 141 if (!compare_ether_addr(p->designated_root.addr, oldaddr)) 142 memcpy(p->designated_root.addr, addr, ETH_ALEN); 143 144 } 145 146 br_configuration_update(br); 147 br_port_state_selection(br); 148 if (br_is_root_bridge(br) && !wasroot) 149 br_become_root_bridge(br); 150 } 151 152 static const unsigned char br_mac_zero[6]; 153 154 /* called under bridge lock */ 155 void br_stp_recalculate_bridge_id(struct net_bridge *br) 156 { 157 const unsigned char *addr = br_mac_zero; 158 struct net_bridge_port *p; 159 160 list_for_each_entry(p, &br->port_list, list) { 161 if (addr == br_mac_zero || 162 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0) 163 addr = p->dev->dev_addr; 164 165 } 166 167 if (compare_ether_addr(br->bridge_id.addr, addr)) 168 br_stp_change_bridge_id(br, addr); 169 } 170 171 /* called under bridge lock */ 172 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) 173 { 174 struct net_bridge_port *p; 175 int wasroot; 176 177 wasroot = br_is_root_bridge(br); 178 179 list_for_each_entry(p, &br->port_list, list) { 180 if (p->state != BR_STATE_DISABLED && 181 br_is_designated_port(p)) { 182 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF; 183 p->designated_bridge.prio[1] = newprio & 0xFF; 184 } 185 186 } 187 188 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF; 189 br->bridge_id.prio[1] = newprio & 0xFF; 190 br_configuration_update(br); 191 br_port_state_selection(br); 192 if (br_is_root_bridge(br) && !wasroot) 193 br_become_root_bridge(br); 194 } 195 196 /* called under bridge lock */ 197 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio) 198 { 199 port_id new_port_id = br_make_port_id(newprio, p->port_no); 200 201 if (br_is_designated_port(p)) 202 p->designated_port = new_port_id; 203 204 p->port_id = new_port_id; 205 p->priority = newprio; 206 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) && 207 p->port_id < p->designated_port) { 208 br_become_designated_port(p); 209 br_port_state_selection(p->br); 210 } 211 } 212 213 /* called under bridge lock */ 214 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost) 215 { 216 p->path_cost = path_cost; 217 br_configuration_update(p->br); 218 br_port_state_selection(p->br); 219 } 220 221 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id) 222 { 223 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n", 224 id->prio[0], id->prio[1], 225 id->addr[0], id->addr[1], id->addr[2], 226 id->addr[3], id->addr[4], id->addr[5]); 227 } 228