1 /* 2 * Userspace interface 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/netdevice.h> 16 #include <linux/ethtool.h> 17 #include <linux/if_arp.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/if_ether.h> 22 #include <net/sock.h> 23 24 #include "br_private.h" 25 26 /* 27 * Determine initial path cost based on speed. 28 * using recommendations from 802.1d standard 29 * 30 * Since driver might sleep need to not be holding any locks. 31 */ 32 static int port_cost(struct net_device *dev) 33 { 34 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { 35 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; 36 37 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) { 38 switch(ecmd.speed) { 39 case SPEED_10000: 40 return 2; 41 case SPEED_1000: 42 return 4; 43 case SPEED_100: 44 return 19; 45 case SPEED_10: 46 return 100; 47 } 48 } 49 } 50 51 /* Old silly heuristics based on name */ 52 if (!strncmp(dev->name, "lec", 3)) 53 return 7; 54 55 if (!strncmp(dev->name, "plip", 4)) 56 return 2500; 57 58 return 100; /* assume old 10Mbps */ 59 } 60 61 62 /* 63 * Check for port carrier transistions. 64 * Called from work queue to allow for calling functions that 65 * might sleep (such as speed check), and to debounce. 66 */ 67 void br_port_carrier_check(struct net_bridge_port *p) 68 { 69 struct net_device *dev = p->dev; 70 struct net_bridge *br = p->br; 71 72 if (netif_carrier_ok(dev)) 73 p->path_cost = port_cost(dev); 74 75 if (netif_running(br->dev)) { 76 spin_lock_bh(&br->lock); 77 if (netif_carrier_ok(dev)) { 78 if (p->state == BR_STATE_DISABLED) 79 br_stp_enable_port(p); 80 } else { 81 if (p->state != BR_STATE_DISABLED) 82 br_stp_disable_port(p); 83 } 84 spin_unlock_bh(&br->lock); 85 } 86 } 87 88 static void release_nbp(struct kobject *kobj) 89 { 90 struct net_bridge_port *p 91 = container_of(kobj, struct net_bridge_port, kobj); 92 kfree(p); 93 } 94 95 static struct kobj_type brport_ktype = { 96 #ifdef CONFIG_SYSFS 97 .sysfs_ops = &brport_sysfs_ops, 98 #endif 99 .release = release_nbp, 100 }; 101 102 static void destroy_nbp(struct net_bridge_port *p) 103 { 104 struct net_device *dev = p->dev; 105 106 p->br = NULL; 107 p->dev = NULL; 108 dev_put(dev); 109 110 kobject_put(&p->kobj); 111 } 112 113 static void destroy_nbp_rcu(struct rcu_head *head) 114 { 115 struct net_bridge_port *p = 116 container_of(head, struct net_bridge_port, rcu); 117 destroy_nbp(p); 118 } 119 120 /* Delete port(interface) from bridge is done in two steps. 121 * via RCU. First step, marks device as down. That deletes 122 * all the timers and stops new packets from flowing through. 123 * 124 * Final cleanup doesn't occur until after all CPU's finished 125 * processing packets. 126 * 127 * Protected from multiple admin operations by RTNL mutex 128 */ 129 static void del_nbp(struct net_bridge_port *p) 130 { 131 struct net_bridge *br = p->br; 132 struct net_device *dev = p->dev; 133 134 sysfs_remove_link(br->ifobj, dev->name); 135 136 dev_set_promiscuity(dev, -1); 137 138 spin_lock_bh(&br->lock); 139 br_stp_disable_port(p); 140 spin_unlock_bh(&br->lock); 141 142 br_ifinfo_notify(RTM_DELLINK, p); 143 144 br_fdb_delete_by_port(br, p, 1); 145 146 list_del_rcu(&p->list); 147 148 rcu_assign_pointer(dev->br_port, NULL); 149 150 kobject_uevent(&p->kobj, KOBJ_REMOVE); 151 kobject_del(&p->kobj); 152 153 call_rcu(&p->rcu, destroy_nbp_rcu); 154 } 155 156 /* called with RTNL */ 157 static void del_br(struct net_bridge *br) 158 { 159 struct net_bridge_port *p, *n; 160 161 list_for_each_entry_safe(p, n, &br->port_list, list) { 162 del_nbp(p); 163 } 164 165 del_timer_sync(&br->gc_timer); 166 167 br_sysfs_delbr(br->dev); 168 unregister_netdevice(br->dev); 169 } 170 171 static struct net_device *new_bridge_dev(struct net *net, const char *name) 172 { 173 struct net_bridge *br; 174 struct net_device *dev; 175 176 dev = alloc_netdev(sizeof(struct net_bridge), name, 177 br_dev_setup); 178 179 if (!dev) 180 return NULL; 181 dev_net_set(dev, net); 182 183 br = netdev_priv(dev); 184 br->dev = dev; 185 186 spin_lock_init(&br->lock); 187 INIT_LIST_HEAD(&br->port_list); 188 spin_lock_init(&br->hash_lock); 189 190 br->bridge_id.prio[0] = 0x80; 191 br->bridge_id.prio[1] = 0x00; 192 193 memcpy(br->group_addr, br_group_address, ETH_ALEN); 194 195 br->feature_mask = dev->features; 196 br->stp_enabled = BR_NO_STP; 197 br->designated_root = br->bridge_id; 198 br->root_path_cost = 0; 199 br->root_port = 0; 200 br->bridge_max_age = br->max_age = 20 * HZ; 201 br->bridge_hello_time = br->hello_time = 2 * HZ; 202 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 203 br->topology_change = 0; 204 br->topology_change_detected = 0; 205 br->ageing_time = 300 * HZ; 206 207 br_netfilter_rtable_init(br); 208 209 INIT_LIST_HEAD(&br->age_list); 210 211 br_stp_timer_init(br); 212 213 return dev; 214 } 215 216 /* find an available port number */ 217 static int find_portno(struct net_bridge *br) 218 { 219 int index; 220 struct net_bridge_port *p; 221 unsigned long *inuse; 222 223 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 224 GFP_KERNEL); 225 if (!inuse) 226 return -ENOMEM; 227 228 set_bit(0, inuse); /* zero is reserved */ 229 list_for_each_entry(p, &br->port_list, list) { 230 set_bit(p->port_no, inuse); 231 } 232 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 233 kfree(inuse); 234 235 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 236 } 237 238 /* called with RTNL but without bridge lock */ 239 static struct net_bridge_port *new_nbp(struct net_bridge *br, 240 struct net_device *dev) 241 { 242 int index; 243 struct net_bridge_port *p; 244 245 index = find_portno(br); 246 if (index < 0) 247 return ERR_PTR(index); 248 249 p = kzalloc(sizeof(*p), GFP_KERNEL); 250 if (p == NULL) 251 return ERR_PTR(-ENOMEM); 252 253 p->br = br; 254 dev_hold(dev); 255 p->dev = dev; 256 p->path_cost = port_cost(dev); 257 p->priority = 0x8000 >> BR_PORT_BITS; 258 p->port_no = index; 259 br_init_port(p); 260 p->state = BR_STATE_DISABLED; 261 br_stp_port_timer_init(p); 262 263 return p; 264 } 265 266 int br_add_bridge(struct net *net, const char *name) 267 { 268 struct net_device *dev; 269 int ret; 270 271 dev = new_bridge_dev(net, name); 272 if (!dev) 273 return -ENOMEM; 274 275 rtnl_lock(); 276 if (strchr(dev->name, '%')) { 277 ret = dev_alloc_name(dev, dev->name); 278 if (ret < 0) 279 goto out_free; 280 } 281 282 ret = register_netdevice(dev); 283 if (ret) 284 goto out_free; 285 286 ret = br_sysfs_addbr(dev); 287 if (ret) 288 unregister_netdevice(dev); 289 out: 290 rtnl_unlock(); 291 return ret; 292 293 out_free: 294 free_netdev(dev); 295 goto out; 296 } 297 298 int br_del_bridge(struct net *net, const char *name) 299 { 300 struct net_device *dev; 301 int ret = 0; 302 303 rtnl_lock(); 304 dev = __dev_get_by_name(net, name); 305 if (dev == NULL) 306 ret = -ENXIO; /* Could not find device */ 307 308 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 309 /* Attempt to delete non bridge device! */ 310 ret = -EPERM; 311 } 312 313 else if (dev->flags & IFF_UP) { 314 /* Not shutdown yet. */ 315 ret = -EBUSY; 316 } 317 318 else 319 del_br(netdev_priv(dev)); 320 321 rtnl_unlock(); 322 return ret; 323 } 324 325 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 326 int br_min_mtu(const struct net_bridge *br) 327 { 328 const struct net_bridge_port *p; 329 int mtu = 0; 330 331 ASSERT_RTNL(); 332 333 if (list_empty(&br->port_list)) 334 mtu = ETH_DATA_LEN; 335 else { 336 list_for_each_entry(p, &br->port_list, list) { 337 if (!mtu || p->dev->mtu < mtu) 338 mtu = p->dev->mtu; 339 } 340 } 341 return mtu; 342 } 343 344 /* 345 * Recomputes features using slave's features 346 */ 347 void br_features_recompute(struct net_bridge *br) 348 { 349 struct net_bridge_port *p; 350 unsigned long features, mask; 351 352 features = mask = br->feature_mask; 353 if (list_empty(&br->port_list)) 354 goto done; 355 356 features &= ~NETIF_F_ONE_FOR_ALL; 357 358 list_for_each_entry(p, &br->port_list, list) { 359 features = netdev_increment_features(features, 360 p->dev->features, mask); 361 } 362 363 done: 364 br->dev->features = netdev_fix_features(features, NULL); 365 } 366 367 /* called with RTNL */ 368 int br_add_if(struct net_bridge *br, struct net_device *dev) 369 { 370 struct net_bridge_port *p; 371 int err = 0; 372 373 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 374 return -EINVAL; 375 376 if (dev->hard_start_xmit == br_dev_xmit) 377 return -ELOOP; 378 379 if (dev->br_port != NULL) 380 return -EBUSY; 381 382 p = new_nbp(br, dev); 383 if (IS_ERR(p)) 384 return PTR_ERR(p); 385 386 err = dev_set_promiscuity(dev, 1); 387 if (err) 388 goto put_back; 389 390 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 391 SYSFS_BRIDGE_PORT_ATTR); 392 if (err) 393 goto err0; 394 395 err = br_fdb_insert(br, p, dev->dev_addr); 396 if (err) 397 goto err1; 398 399 err = br_sysfs_addif(p); 400 if (err) 401 goto err2; 402 403 rcu_assign_pointer(dev->br_port, p); 404 dev_disable_lro(dev); 405 406 list_add_rcu(&p->list, &br->port_list); 407 408 spin_lock_bh(&br->lock); 409 br_stp_recalculate_bridge_id(br); 410 br_features_recompute(br); 411 412 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 413 (br->dev->flags & IFF_UP)) 414 br_stp_enable_port(p); 415 spin_unlock_bh(&br->lock); 416 417 br_ifinfo_notify(RTM_NEWLINK, p); 418 419 dev_set_mtu(br->dev, br_min_mtu(br)); 420 421 kobject_uevent(&p->kobj, KOBJ_ADD); 422 423 return 0; 424 err2: 425 br_fdb_delete_by_port(br, p, 1); 426 err1: 427 kobject_del(&p->kobj); 428 err0: 429 kobject_put(&p->kobj); 430 dev_set_promiscuity(dev, -1); 431 put_back: 432 dev_put(dev); 433 kfree(p); 434 return err; 435 } 436 437 /* called with RTNL */ 438 int br_del_if(struct net_bridge *br, struct net_device *dev) 439 { 440 struct net_bridge_port *p = dev->br_port; 441 442 if (!p || p->br != br) 443 return -EINVAL; 444 445 del_nbp(p); 446 447 spin_lock_bh(&br->lock); 448 br_stp_recalculate_bridge_id(br); 449 br_features_recompute(br); 450 spin_unlock_bh(&br->lock); 451 452 return 0; 453 } 454 455 void br_net_exit(struct net *net) 456 { 457 struct net_device *dev; 458 459 rtnl_lock(); 460 restart: 461 for_each_netdev(net, dev) { 462 if (dev->priv_flags & IFF_EBRIDGE) { 463 del_br(dev->priv); 464 goto restart; 465 } 466 } 467 rtnl_unlock(); 468 469 } 470