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/netpoll.h> 17 #include <linux/ethtool.h> 18 #include <linux/if_arp.h> 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/rtnetlink.h> 22 #include <linux/if_ether.h> 23 #include <linux/slab.h> 24 #include <net/sock.h> 25 26 #include "br_private.h" 27 28 /* 29 * Determine initial path cost based on speed. 30 * using recommendations from 802.1d standard 31 * 32 * Since driver might sleep need to not be holding any locks. 33 */ 34 static int port_cost(struct net_device *dev) 35 { 36 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { 37 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; 38 39 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) { 40 switch(ecmd.speed) { 41 case SPEED_10000: 42 return 2; 43 case SPEED_1000: 44 return 4; 45 case SPEED_100: 46 return 19; 47 case SPEED_10: 48 return 100; 49 } 50 } 51 } 52 53 /* Old silly heuristics based on name */ 54 if (!strncmp(dev->name, "lec", 3)) 55 return 7; 56 57 if (!strncmp(dev->name, "plip", 4)) 58 return 2500; 59 60 return 100; /* assume old 10Mbps */ 61 } 62 63 64 /* 65 * Check for port carrier transistions. 66 * Called from work queue to allow for calling functions that 67 * might sleep (such as speed check), and to debounce. 68 */ 69 void br_port_carrier_check(struct net_bridge_port *p) 70 { 71 struct net_device *dev = p->dev; 72 struct net_bridge *br = p->br; 73 74 if (netif_carrier_ok(dev)) 75 p->path_cost = port_cost(dev); 76 77 if (netif_running(br->dev)) { 78 spin_lock_bh(&br->lock); 79 if (netif_carrier_ok(dev)) { 80 if (p->state == BR_STATE_DISABLED) 81 br_stp_enable_port(p); 82 } else { 83 if (p->state != BR_STATE_DISABLED) 84 br_stp_disable_port(p); 85 } 86 spin_unlock_bh(&br->lock); 87 } 88 } 89 90 static void release_nbp(struct kobject *kobj) 91 { 92 struct net_bridge_port *p 93 = container_of(kobj, struct net_bridge_port, kobj); 94 kfree(p); 95 } 96 97 static struct kobj_type brport_ktype = { 98 #ifdef CONFIG_SYSFS 99 .sysfs_ops = &brport_sysfs_ops, 100 #endif 101 .release = release_nbp, 102 }; 103 104 static void destroy_nbp(struct net_bridge_port *p) 105 { 106 struct net_device *dev = p->dev; 107 108 p->br = NULL; 109 p->dev = NULL; 110 dev_put(dev); 111 112 kobject_put(&p->kobj); 113 } 114 115 static void destroy_nbp_rcu(struct rcu_head *head) 116 { 117 struct net_bridge_port *p = 118 container_of(head, struct net_bridge_port, rcu); 119 destroy_nbp(p); 120 } 121 122 /* Delete port(interface) from bridge is done in two steps. 123 * via RCU. First step, marks device as down. That deletes 124 * all the timers and stops new packets from flowing through. 125 * 126 * Final cleanup doesn't occur until after all CPU's finished 127 * processing packets. 128 * 129 * Protected from multiple admin operations by RTNL mutex 130 */ 131 static void del_nbp(struct net_bridge_port *p) 132 { 133 struct net_bridge *br = p->br; 134 struct net_device *dev = p->dev; 135 136 sysfs_remove_link(br->ifobj, p->dev->name); 137 138 dev_set_promiscuity(dev, -1); 139 140 spin_lock_bh(&br->lock); 141 br_stp_disable_port(p); 142 spin_unlock_bh(&br->lock); 143 144 br_ifinfo_notify(RTM_DELLINK, p); 145 146 br_fdb_delete_by_port(br, p, 1); 147 148 list_del_rcu(&p->list); 149 150 dev->priv_flags &= ~IFF_BRIDGE_PORT; 151 152 netdev_rx_handler_unregister(dev); 153 154 br_multicast_del_port(p); 155 156 kobject_uevent(&p->kobj, KOBJ_REMOVE); 157 kobject_del(&p->kobj); 158 159 br_netpoll_disable(p); 160 161 call_rcu(&p->rcu, destroy_nbp_rcu); 162 } 163 164 /* called with RTNL */ 165 static void del_br(struct net_bridge *br, struct list_head *head) 166 { 167 struct net_bridge_port *p, *n; 168 169 list_for_each_entry_safe(p, n, &br->port_list, list) { 170 del_nbp(p); 171 } 172 173 del_timer_sync(&br->gc_timer); 174 175 br_sysfs_delbr(br->dev); 176 unregister_netdevice_queue(br->dev, head); 177 } 178 179 static struct net_device *new_bridge_dev(struct net *net, const char *name) 180 { 181 struct net_bridge *br; 182 struct net_device *dev; 183 184 dev = alloc_netdev(sizeof(struct net_bridge), name, 185 br_dev_setup); 186 187 if (!dev) 188 return NULL; 189 dev_net_set(dev, net); 190 191 br = netdev_priv(dev); 192 br->dev = dev; 193 194 br->stats = alloc_percpu(struct br_cpu_netstats); 195 if (!br->stats) { 196 free_netdev(dev); 197 return NULL; 198 } 199 200 spin_lock_init(&br->lock); 201 INIT_LIST_HEAD(&br->port_list); 202 spin_lock_init(&br->hash_lock); 203 204 br->bridge_id.prio[0] = 0x80; 205 br->bridge_id.prio[1] = 0x00; 206 207 memcpy(br->group_addr, br_group_address, ETH_ALEN); 208 209 br->feature_mask = dev->features; 210 br->stp_enabled = BR_NO_STP; 211 br->designated_root = br->bridge_id; 212 br->root_path_cost = 0; 213 br->root_port = 0; 214 br->bridge_max_age = br->max_age = 20 * HZ; 215 br->bridge_hello_time = br->hello_time = 2 * HZ; 216 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 217 br->topology_change = 0; 218 br->topology_change_detected = 0; 219 br->ageing_time = 300 * HZ; 220 221 br_netfilter_rtable_init(br); 222 223 br_stp_timer_init(br); 224 br_multicast_init(br); 225 226 return dev; 227 } 228 229 /* find an available port number */ 230 static int find_portno(struct net_bridge *br) 231 { 232 int index; 233 struct net_bridge_port *p; 234 unsigned long *inuse; 235 236 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 237 GFP_KERNEL); 238 if (!inuse) 239 return -ENOMEM; 240 241 set_bit(0, inuse); /* zero is reserved */ 242 list_for_each_entry(p, &br->port_list, list) { 243 set_bit(p->port_no, inuse); 244 } 245 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 246 kfree(inuse); 247 248 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 249 } 250 251 /* called with RTNL but without bridge lock */ 252 static struct net_bridge_port *new_nbp(struct net_bridge *br, 253 struct net_device *dev) 254 { 255 int index; 256 struct net_bridge_port *p; 257 258 index = find_portno(br); 259 if (index < 0) 260 return ERR_PTR(index); 261 262 p = kzalloc(sizeof(*p), GFP_KERNEL); 263 if (p == NULL) 264 return ERR_PTR(-ENOMEM); 265 266 p->br = br; 267 dev_hold(dev); 268 p->dev = dev; 269 p->path_cost = port_cost(dev); 270 p->priority = 0x8000 >> BR_PORT_BITS; 271 p->port_no = index; 272 p->flags = 0; 273 br_init_port(p); 274 p->state = BR_STATE_DISABLED; 275 br_stp_port_timer_init(p); 276 br_multicast_add_port(p); 277 278 return p; 279 } 280 281 static struct device_type br_type = { 282 .name = "bridge", 283 }; 284 285 int br_add_bridge(struct net *net, const char *name) 286 { 287 struct net_device *dev; 288 int ret; 289 290 dev = new_bridge_dev(net, name); 291 if (!dev) 292 return -ENOMEM; 293 294 rtnl_lock(); 295 if (strchr(dev->name, '%')) { 296 ret = dev_alloc_name(dev, dev->name); 297 if (ret < 0) 298 goto out_free; 299 } 300 301 SET_NETDEV_DEVTYPE(dev, &br_type); 302 303 ret = register_netdevice(dev); 304 if (ret) 305 goto out_free; 306 307 ret = br_sysfs_addbr(dev); 308 if (ret) 309 unregister_netdevice(dev); 310 out: 311 rtnl_unlock(); 312 return ret; 313 314 out_free: 315 free_netdev(dev); 316 goto out; 317 } 318 319 int br_del_bridge(struct net *net, const char *name) 320 { 321 struct net_device *dev; 322 int ret = 0; 323 324 rtnl_lock(); 325 dev = __dev_get_by_name(net, name); 326 if (dev == NULL) 327 ret = -ENXIO; /* Could not find device */ 328 329 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 330 /* Attempt to delete non bridge device! */ 331 ret = -EPERM; 332 } 333 334 else if (dev->flags & IFF_UP) { 335 /* Not shutdown yet. */ 336 ret = -EBUSY; 337 } 338 339 else 340 del_br(netdev_priv(dev), NULL); 341 342 rtnl_unlock(); 343 return ret; 344 } 345 346 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 347 int br_min_mtu(const struct net_bridge *br) 348 { 349 const struct net_bridge_port *p; 350 int mtu = 0; 351 352 ASSERT_RTNL(); 353 354 if (list_empty(&br->port_list)) 355 mtu = ETH_DATA_LEN; 356 else { 357 list_for_each_entry(p, &br->port_list, list) { 358 if (!mtu || p->dev->mtu < mtu) 359 mtu = p->dev->mtu; 360 } 361 } 362 return mtu; 363 } 364 365 /* 366 * Recomputes features using slave's features 367 */ 368 void br_features_recompute(struct net_bridge *br) 369 { 370 struct net_bridge_port *p; 371 unsigned long features, mask; 372 373 features = mask = br->feature_mask; 374 if (list_empty(&br->port_list)) 375 goto done; 376 377 features &= ~NETIF_F_ONE_FOR_ALL; 378 379 list_for_each_entry(p, &br->port_list, list) { 380 features = netdev_increment_features(features, 381 p->dev->features, mask); 382 } 383 384 done: 385 br->dev->features = netdev_fix_features(features, NULL); 386 } 387 388 /* called with RTNL */ 389 int br_add_if(struct net_bridge *br, struct net_device *dev) 390 { 391 struct net_bridge_port *p; 392 int err = 0; 393 394 /* Don't allow bridging non-ethernet like devices */ 395 if ((dev->flags & IFF_LOOPBACK) || 396 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN) 397 return -EINVAL; 398 399 /* No bridging of bridges */ 400 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 401 return -ELOOP; 402 403 /* Device is already being bridged */ 404 if (br_port_exists(dev)) 405 return -EBUSY; 406 407 /* No bridging devices that dislike that (e.g. wireless) */ 408 if (dev->priv_flags & IFF_DONT_BRIDGE) 409 return -EOPNOTSUPP; 410 411 p = new_nbp(br, dev); 412 if (IS_ERR(p)) 413 return PTR_ERR(p); 414 415 err = dev_set_promiscuity(dev, 1); 416 if (err) 417 goto put_back; 418 419 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 420 SYSFS_BRIDGE_PORT_ATTR); 421 if (err) 422 goto err0; 423 424 err = br_fdb_insert(br, p, dev->dev_addr); 425 if (err) 426 goto err1; 427 428 err = br_sysfs_addif(p); 429 if (err) 430 goto err2; 431 432 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) 433 goto err3; 434 435 err = netdev_rx_handler_register(dev, br_handle_frame, p); 436 if (err) 437 goto err3; 438 439 dev->priv_flags |= IFF_BRIDGE_PORT; 440 441 dev_disable_lro(dev); 442 443 list_add_rcu(&p->list, &br->port_list); 444 445 spin_lock_bh(&br->lock); 446 br_stp_recalculate_bridge_id(br); 447 br_features_recompute(br); 448 449 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 450 (br->dev->flags & IFF_UP)) 451 br_stp_enable_port(p); 452 spin_unlock_bh(&br->lock); 453 454 br_ifinfo_notify(RTM_NEWLINK, p); 455 456 dev_set_mtu(br->dev, br_min_mtu(br)); 457 458 kobject_uevent(&p->kobj, KOBJ_ADD); 459 460 return 0; 461 err3: 462 sysfs_remove_link(br->ifobj, p->dev->name); 463 err2: 464 br_fdb_delete_by_port(br, p, 1); 465 err1: 466 kobject_put(&p->kobj); 467 p = NULL; /* kobject_put frees */ 468 err0: 469 dev_set_promiscuity(dev, -1); 470 put_back: 471 dev_put(dev); 472 kfree(p); 473 return err; 474 } 475 476 /* called with RTNL */ 477 int br_del_if(struct net_bridge *br, struct net_device *dev) 478 { 479 struct net_bridge_port *p; 480 481 if (!br_port_exists(dev)) 482 return -EINVAL; 483 484 p = br_port_get(dev); 485 if (p->br != br) 486 return -EINVAL; 487 488 del_nbp(p); 489 490 spin_lock_bh(&br->lock); 491 br_stp_recalculate_bridge_id(br); 492 br_features_recompute(br); 493 spin_unlock_bh(&br->lock); 494 495 return 0; 496 } 497 498 void __net_exit br_net_exit(struct net *net) 499 { 500 struct net_device *dev; 501 LIST_HEAD(list); 502 503 rtnl_lock(); 504 for_each_netdev(net, dev) 505 if (dev->priv_flags & IFF_EBRIDGE) 506 del_br(netdev_priv(dev), &list); 507 508 unregister_netdevice_many(&list); 509 rtnl_unlock(); 510 511 } 512