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 19 #include "br_private.h" 20 #include "br_private_stp.h" 21 22 23 /* Port id is composed of priority and port number. 24 * NB: least significant bits of priority are dropped to 25 * make room for more ports. 26 */ 27 static inline port_id br_make_port_id(__u8 priority, __u16 port_no) 28 { 29 return ((u16)priority << BR_PORT_BITS) 30 | (port_no & ((1<<BR_PORT_BITS)-1)); 31 } 32 33 /* called under bridge lock */ 34 void br_init_port(struct net_bridge_port *p) 35 { 36 p->port_id = br_make_port_id(p->priority, p->port_no); 37 br_become_designated_port(p); 38 p->state = BR_STATE_BLOCKING; 39 p->topology_change_ack = 0; 40 p->config_pending = 0; 41 42 br_stp_port_timer_init(p); 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(&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(&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_port_state_selection(p->br); 91 } 92 93 /* called under bridge lock */ 94 void br_stp_disable_port(struct net_bridge_port *p) 95 { 96 struct net_bridge *br; 97 int wasroot; 98 99 br = p->br; 100 printk(KERN_INFO "%s: port %i(%s) entering %s state\n", 101 br->dev->name, p->port_no, p->dev->name, "disabled"); 102 103 wasroot = br_is_root_bridge(br); 104 br_become_designated_port(p); 105 p->state = BR_STATE_DISABLED; 106 p->topology_change_ack = 0; 107 p->config_pending = 0; 108 109 del_timer(&p->message_age_timer); 110 del_timer(&p->forward_delay_timer); 111 del_timer(&p->hold_timer); 112 113 br_configuration_update(br); 114 115 br_port_state_selection(br); 116 117 if (br_is_root_bridge(br) && !wasroot) 118 br_become_root_bridge(br); 119 } 120 121 /* called under bridge lock */ 122 static void br_stp_change_bridge_id(struct net_bridge *br, 123 const unsigned char *addr) 124 { 125 unsigned char oldaddr[6]; 126 struct net_bridge_port *p; 127 int wasroot; 128 129 wasroot = br_is_root_bridge(br); 130 131 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); 132 memcpy(br->bridge_id.addr, addr, ETH_ALEN); 133 memcpy(br->dev->dev_addr, addr, ETH_ALEN); 134 135 list_for_each_entry(p, &br->port_list, list) { 136 if (!memcmp(p->designated_bridge.addr, oldaddr, ETH_ALEN)) 137 memcpy(p->designated_bridge.addr, addr, ETH_ALEN); 138 139 if (!memcmp(p->designated_root.addr, oldaddr, ETH_ALEN)) 140 memcpy(p->designated_root.addr, addr, ETH_ALEN); 141 142 } 143 144 br_configuration_update(br); 145 br_port_state_selection(br); 146 if (br_is_root_bridge(br) && !wasroot) 147 br_become_root_bridge(br); 148 } 149 150 static const unsigned char br_mac_zero[6]; 151 152 /* called under bridge lock */ 153 void br_stp_recalculate_bridge_id(struct net_bridge *br) 154 { 155 const unsigned char *addr = br_mac_zero; 156 struct net_bridge_port *p; 157 158 list_for_each_entry(p, &br->port_list, list) { 159 if (addr == br_mac_zero || 160 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0) 161 addr = p->dev->dev_addr; 162 163 } 164 165 if (memcmp(br->bridge_id.addr, addr, ETH_ALEN)) 166 br_stp_change_bridge_id(br, addr); 167 } 168 169 /* called under bridge lock */ 170 void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) 171 { 172 struct net_bridge_port *p; 173 int wasroot; 174 175 wasroot = br_is_root_bridge(br); 176 177 list_for_each_entry(p, &br->port_list, list) { 178 if (p->state != BR_STATE_DISABLED && 179 br_is_designated_port(p)) { 180 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF; 181 p->designated_bridge.prio[1] = newprio & 0xFF; 182 } 183 184 } 185 186 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF; 187 br->bridge_id.prio[1] = newprio & 0xFF; 188 br_configuration_update(br); 189 br_port_state_selection(br); 190 if (br_is_root_bridge(br) && !wasroot) 191 br_become_root_bridge(br); 192 } 193 194 /* called under bridge lock */ 195 void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio) 196 { 197 port_id new_port_id = br_make_port_id(newprio, p->port_no); 198 199 if (br_is_designated_port(p)) 200 p->designated_port = new_port_id; 201 202 p->port_id = new_port_id; 203 p->priority = newprio; 204 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) && 205 p->port_id < p->designated_port) { 206 br_become_designated_port(p); 207 br_port_state_selection(p->br); 208 } 209 } 210 211 /* called under bridge lock */ 212 void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost) 213 { 214 p->path_cost = path_cost; 215 br_configuration_update(p->br); 216 br_port_state_selection(p->br); 217 } 218 219 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id) 220 { 221 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n", 222 id->prio[0], id->prio[1], 223 id->addr[0], id->addr[1], id->addr[2], 224 id->addr[3], id->addr[4], id->addr[5]); 225 } 226