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 1.1.1.1 2007/08/03 18:53:50 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/etherdevice.h> 18#include <linux/rtnetlink.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 */ 28static 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 */ 35void 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 44/* called under bridge lock */ 45void br_stp_enable_bridge(struct net_bridge *br) 46{ 47 struct net_bridge_port *p; 48 49 spin_lock_bh(&br->lock); 50 mod_timer(&br->hello_timer, jiffies + br->hello_time); 51 mod_timer(&br->gc_timer, jiffies + HZ/10); 52 53 br_config_bpdu_generation(br); 54 55 list_for_each_entry(p, &br->port_list, list) { 56 if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev)) 57 br_stp_enable_port(p); 58 59 } 60 spin_unlock_bh(&br->lock); 61} 62 63/* NO locks held */ 64void br_stp_disable_bridge(struct net_bridge *br) 65{ 66 struct net_bridge_port *p; 67 68 spin_lock_bh(&br->lock); 69 list_for_each_entry(p, &br->port_list, list) { 70 if (p->state != BR_STATE_DISABLED) 71 br_stp_disable_port(p); 72 73 } 74 75 br->topology_change = 0; 76 br->topology_change_detected = 0; 77 spin_unlock_bh(&br->lock); 78 79 del_timer_sync(&br->hello_timer); 80 del_timer_sync(&br->topology_change_timer); 81 del_timer_sync(&br->tcn_timer); 82 del_timer_sync(&br->gc_timer); 83} 84 85/* called under bridge lock */ 86void br_stp_enable_port(struct net_bridge_port *p) 87{ 88 br_init_port(p); 89 br_port_state_selection(p->br); 90} 91 92/* called under bridge lock */ 93void br_stp_disable_port(struct net_bridge_port *p) 94{ 95 struct net_bridge *br; 96 int wasroot; 97 98 br = p->br; 99 printk(KERN_INFO "%s: port %i(%s) entering %s state\n", 100 br->dev->name, p->port_no, p->dev->name, "disabled"); 101 102 wasroot = br_is_root_bridge(br); 103 br_become_designated_port(p); 104 p->state = BR_STATE_DISABLED; 105 p->topology_change_ack = 0; 106 p->config_pending = 0; 107 108 del_timer(&p->message_age_timer); 109 del_timer(&p->forward_delay_timer); 110 del_timer(&p->hold_timer); 111 112 br_fdb_delete_by_port(br, p, 0); 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 122static void br_stp_start(struct net_bridge *br) 123{ 124 int r; 125 char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL }; 126 char *envp[] = { NULL }; 127 128 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1); 129 if (r == 0) { 130 br->stp_enabled = BR_USER_STP; 131 printk(KERN_INFO "%s: userspace STP started\n", br->dev->name); 132 } else { 133 br->stp_enabled = BR_KERNEL_STP; 134 printk(KERN_INFO "%s: starting userspace STP failed, " 135 "staring kernel STP\n", br->dev->name); 136 137 /* To start timers on any ports left in blocking */ 138 spin_lock_bh(&br->lock); 139 br_port_state_selection(br); 140 spin_unlock_bh(&br->lock); 141 } 142} 143 144static void br_stp_stop(struct net_bridge *br) 145{ 146 int r; 147 char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL }; 148 char *envp[] = { NULL }; 149 150 if (br->stp_enabled == BR_USER_STP) { 151 r = call_usermodehelper(BR_STP_PROG, argv, envp, 1); 152 printk(KERN_INFO "%s: userspace STP stopped, return code %d\n", 153 br->dev->name, r); 154 155 156 /* To start timers on any ports left in blocking */ 157 spin_lock_bh(&br->lock); 158 br_port_state_selection(br); 159 spin_unlock_bh(&br->lock); 160 } 161 162 br->stp_enabled = BR_NO_STP; 163} 164 165void br_stp_set_enabled(struct net_bridge *br, unsigned long val) 166{ 167 ASSERT_RTNL(); 168 169 if (val) { 170 if (br->stp_enabled == BR_NO_STP) 171 br_stp_start(br); 172 } else { 173 if (br->stp_enabled != BR_NO_STP) 174 br_stp_stop(br); 175 } 176} 177 178/* called under bridge lock */ 179void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr) 180{ 181 /* should be aligned on 2 bytes for compare_ether_addr() */ 182 unsigned short oldaddr_aligned[ETH_ALEN >> 1]; 183 unsigned char *oldaddr = (unsigned char *)oldaddr_aligned; 184 struct net_bridge_port *p; 185 int wasroot; 186 187 wasroot = br_is_root_bridge(br); 188 189 memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN); 190 memcpy(br->bridge_id.addr, addr, ETH_ALEN); 191 memcpy(br->dev->dev_addr, addr, ETH_ALEN); 192 193 list_for_each_entry(p, &br->port_list, list) { 194 if (!compare_ether_addr(p->designated_bridge.addr, oldaddr)) 195 memcpy(p->designated_bridge.addr, addr, ETH_ALEN); 196 197 if (!compare_ether_addr(p->designated_root.addr, oldaddr)) 198 memcpy(p->designated_root.addr, addr, ETH_ALEN); 199 200 } 201 202 br_configuration_update(br); 203 br_port_state_selection(br); 204 if (br_is_root_bridge(br) && !wasroot) 205 br_become_root_bridge(br); 206} 207 208/* should be aligned on 2 bytes for compare_ether_addr() */ 209static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1]; 210 211/* called under bridge lock */ 212void br_stp_recalculate_bridge_id(struct net_bridge *br) 213{ 214 const unsigned char *br_mac_zero = 215 (const unsigned char *)br_mac_zero_aligned; 216 const unsigned char *addr = br_mac_zero; 217 struct net_bridge_port *p; 218 219 list_for_each_entry(p, &br->port_list, list) { 220 /* foxconn Bob removed start, always use first added if's mac as bridge mac address */ 221 #if 0 222 if (addr == br_mac_zero || 223 memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0) 224 #endif 225 /* foxconn Bob removed end */ 226 addr = p->dev->dev_addr; 227 228 } 229 230 if (compare_ether_addr(br->bridge_id.addr, addr)) 231 br_stp_change_bridge_id(br, addr); 232} 233 234/* called under bridge lock */ 235void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio) 236{ 237 struct net_bridge_port *p; 238 int wasroot; 239 240 wasroot = br_is_root_bridge(br); 241 242 list_for_each_entry(p, &br->port_list, list) { 243 if (p->state != BR_STATE_DISABLED && 244 br_is_designated_port(p)) { 245 p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF; 246 p->designated_bridge.prio[1] = newprio & 0xFF; 247 } 248 249 } 250 251 br->bridge_id.prio[0] = (newprio >> 8) & 0xFF; 252 br->bridge_id.prio[1] = newprio & 0xFF; 253 br_configuration_update(br); 254 br_port_state_selection(br); 255 if (br_is_root_bridge(br) && !wasroot) 256 br_become_root_bridge(br); 257} 258 259/* called under bridge lock */ 260void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio) 261{ 262 port_id new_port_id = br_make_port_id(newprio, p->port_no); 263 264 if (br_is_designated_port(p)) 265 p->designated_port = new_port_id; 266 267 p->port_id = new_port_id; 268 p->priority = newprio; 269 if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) && 270 p->port_id < p->designated_port) { 271 br_become_designated_port(p); 272 br_port_state_selection(p->br); 273 } 274} 275 276/* called under bridge lock */ 277void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost) 278{ 279 p->path_cost = path_cost; 280 br_configuration_update(p->br); 281 br_port_state_selection(p->br); 282} 283 284ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id) 285{ 286 return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n", 287 id->prio[0], id->prio[1], 288 id->addr[0], id->addr[1], id->addr[2], 289 id->addr[3], id->addr[4], id->addr[5]); 290} 291