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 rcu_assign_pointer(dev->br_port, NULL); 151 152 br_multicast_del_port(p); 153 154 kobject_uevent(&p->kobj, KOBJ_REMOVE); 155 kobject_del(&p->kobj); 156 157 br_netpoll_disable(br, dev); 158 call_rcu(&p->rcu, destroy_nbp_rcu); 159 } 160 161 /* called with RTNL */ 162 static void del_br(struct net_bridge *br, struct list_head *head) 163 { 164 struct net_bridge_port *p, *n; 165 166 list_for_each_entry_safe(p, n, &br->port_list, list) { 167 del_nbp(p); 168 } 169 170 br_netpoll_cleanup(br->dev); 171 172 del_timer_sync(&br->gc_timer); 173 174 br_sysfs_delbr(br->dev); 175 unregister_netdevice_queue(br->dev, head); 176 } 177 178 static struct net_device *new_bridge_dev(struct net *net, const char *name) 179 { 180 struct net_bridge *br; 181 struct net_device *dev; 182 183 dev = alloc_netdev(sizeof(struct net_bridge), name, 184 br_dev_setup); 185 186 if (!dev) 187 return NULL; 188 dev_net_set(dev, net); 189 190 br = netdev_priv(dev); 191 br->dev = dev; 192 193 br->stats = alloc_percpu(struct br_cpu_netstats); 194 if (!br->stats) { 195 free_netdev(dev); 196 return NULL; 197 } 198 199 spin_lock_init(&br->lock); 200 INIT_LIST_HEAD(&br->port_list); 201 spin_lock_init(&br->hash_lock); 202 203 br->bridge_id.prio[0] = 0x80; 204 br->bridge_id.prio[1] = 0x00; 205 206 memcpy(br->group_addr, br_group_address, ETH_ALEN); 207 208 br->feature_mask = dev->features; 209 br->stp_enabled = BR_NO_STP; 210 br->designated_root = br->bridge_id; 211 br->root_path_cost = 0; 212 br->root_port = 0; 213 br->bridge_max_age = br->max_age = 20 * HZ; 214 br->bridge_hello_time = br->hello_time = 2 * HZ; 215 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 216 br->topology_change = 0; 217 br->topology_change_detected = 0; 218 br->ageing_time = 300 * HZ; 219 220 br_netfilter_rtable_init(br); 221 222 br_stp_timer_init(br); 223 br_multicast_init(br); 224 225 return dev; 226 } 227 228 /* find an available port number */ 229 static int find_portno(struct net_bridge *br) 230 { 231 int index; 232 struct net_bridge_port *p; 233 unsigned long *inuse; 234 235 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 236 GFP_KERNEL); 237 if (!inuse) 238 return -ENOMEM; 239 240 set_bit(0, inuse); /* zero is reserved */ 241 list_for_each_entry(p, &br->port_list, list) { 242 set_bit(p->port_no, inuse); 243 } 244 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 245 kfree(inuse); 246 247 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 248 } 249 250 /* called with RTNL but without bridge lock */ 251 static struct net_bridge_port *new_nbp(struct net_bridge *br, 252 struct net_device *dev) 253 { 254 int index; 255 struct net_bridge_port *p; 256 257 index = find_portno(br); 258 if (index < 0) 259 return ERR_PTR(index); 260 261 p = kzalloc(sizeof(*p), GFP_KERNEL); 262 if (p == NULL) 263 return ERR_PTR(-ENOMEM); 264 265 p->br = br; 266 dev_hold(dev); 267 p->dev = dev; 268 p->path_cost = port_cost(dev); 269 p->priority = 0x8000 >> BR_PORT_BITS; 270 p->port_no = index; 271 p->flags = 0; 272 br_init_port(p); 273 p->state = BR_STATE_DISABLED; 274 br_stp_port_timer_init(p); 275 br_multicast_add_port(p); 276 277 return p; 278 } 279 280 static struct device_type br_type = { 281 .name = "bridge", 282 }; 283 284 int br_add_bridge(struct net *net, const char *name) 285 { 286 struct net_device *dev; 287 int ret; 288 289 dev = new_bridge_dev(net, name); 290 if (!dev) 291 return -ENOMEM; 292 293 rtnl_lock(); 294 if (strchr(dev->name, '%')) { 295 ret = dev_alloc_name(dev, dev->name); 296 if (ret < 0) 297 goto out_free; 298 } 299 300 SET_NETDEV_DEVTYPE(dev, &br_type); 301 302 ret = register_netdevice(dev); 303 if (ret) 304 goto out_free; 305 306 ret = br_sysfs_addbr(dev); 307 if (ret) 308 unregister_netdevice(dev); 309 out: 310 rtnl_unlock(); 311 return ret; 312 313 out_free: 314 free_netdev(dev); 315 goto out; 316 } 317 318 int br_del_bridge(struct net *net, const char *name) 319 { 320 struct net_device *dev; 321 int ret = 0; 322 323 rtnl_lock(); 324 dev = __dev_get_by_name(net, name); 325 if (dev == NULL) 326 ret = -ENXIO; /* Could not find device */ 327 328 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 329 /* Attempt to delete non bridge device! */ 330 ret = -EPERM; 331 } 332 333 else if (dev->flags & IFF_UP) { 334 /* Not shutdown yet. */ 335 ret = -EBUSY; 336 } 337 338 else 339 del_br(netdev_priv(dev), NULL); 340 341 rtnl_unlock(); 342 return ret; 343 } 344 345 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 346 int br_min_mtu(const struct net_bridge *br) 347 { 348 const struct net_bridge_port *p; 349 int mtu = 0; 350 351 ASSERT_RTNL(); 352 353 if (list_empty(&br->port_list)) 354 mtu = ETH_DATA_LEN; 355 else { 356 list_for_each_entry(p, &br->port_list, list) { 357 if (!mtu || p->dev->mtu < mtu) 358 mtu = p->dev->mtu; 359 } 360 } 361 return mtu; 362 } 363 364 /* 365 * Recomputes features using slave's features 366 */ 367 void br_features_recompute(struct net_bridge *br) 368 { 369 struct net_bridge_port *p; 370 unsigned long features, mask; 371 372 features = mask = br->feature_mask; 373 if (list_empty(&br->port_list)) 374 goto done; 375 376 features &= ~NETIF_F_ONE_FOR_ALL; 377 378 list_for_each_entry(p, &br->port_list, list) { 379 features = netdev_increment_features(features, 380 p->dev->features, mask); 381 } 382 383 done: 384 br->dev->features = netdev_fix_features(features, NULL); 385 } 386 387 /* called with RTNL */ 388 int br_add_if(struct net_bridge *br, struct net_device *dev) 389 { 390 struct net_bridge_port *p; 391 int err = 0; 392 393 /* Don't allow bridging non-ethernet like devices */ 394 if ((dev->flags & IFF_LOOPBACK) || 395 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN) 396 return -EINVAL; 397 398 /* No bridging of bridges */ 399 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 400 return -ELOOP; 401 402 /* Device is already being bridged */ 403 if (dev->br_port != NULL) 404 return -EBUSY; 405 406 /* No bridging devices that dislike that (e.g. wireless) */ 407 if (dev->priv_flags & IFF_DONT_BRIDGE) 408 return -EOPNOTSUPP; 409 410 p = new_nbp(br, dev); 411 if (IS_ERR(p)) 412 return PTR_ERR(p); 413 414 err = dev_set_promiscuity(dev, 1); 415 if (err) 416 goto put_back; 417 418 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 419 SYSFS_BRIDGE_PORT_ATTR); 420 if (err) 421 goto err0; 422 423 err = br_fdb_insert(br, p, dev->dev_addr); 424 if (err) 425 goto err1; 426 427 err = br_sysfs_addif(p); 428 if (err) 429 goto err2; 430 431 rcu_assign_pointer(dev->br_port, p); 432 dev_disable_lro(dev); 433 434 list_add_rcu(&p->list, &br->port_list); 435 436 spin_lock_bh(&br->lock); 437 br_stp_recalculate_bridge_id(br); 438 br_features_recompute(br); 439 440 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 441 (br->dev->flags & IFF_UP)) 442 br_stp_enable_port(p); 443 spin_unlock_bh(&br->lock); 444 445 br_ifinfo_notify(RTM_NEWLINK, p); 446 447 dev_set_mtu(br->dev, br_min_mtu(br)); 448 449 kobject_uevent(&p->kobj, KOBJ_ADD); 450 451 br_netpoll_enable(br, dev); 452 453 return 0; 454 err2: 455 br_fdb_delete_by_port(br, p, 1); 456 err1: 457 kobject_put(&p->kobj); 458 p = NULL; /* kobject_put frees */ 459 err0: 460 dev_set_promiscuity(dev, -1); 461 put_back: 462 dev_put(dev); 463 kfree(p); 464 return err; 465 } 466 467 /* called with RTNL */ 468 int br_del_if(struct net_bridge *br, struct net_device *dev) 469 { 470 struct net_bridge_port *p = dev->br_port; 471 472 if (!p || p->br != br) 473 return -EINVAL; 474 475 del_nbp(p); 476 477 spin_lock_bh(&br->lock); 478 br_stp_recalculate_bridge_id(br); 479 br_features_recompute(br); 480 spin_unlock_bh(&br->lock); 481 482 return 0; 483 } 484 485 void __net_exit br_net_exit(struct net *net) 486 { 487 struct net_device *dev; 488 LIST_HEAD(list); 489 490 rtnl_lock(); 491 for_each_netdev(net, dev) 492 if (dev->priv_flags & IFF_EBRIDGE) 493 del_br(netdev_priv(dev), &list); 494 495 unregister_netdevice_many(&list); 496 rtnl_unlock(); 497 498 } 499