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/etherdevice.h> 17 #include <linux/netpoll.h> 18 #include <linux/ethtool.h> 19 #include <linux/if_arp.h> 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/rtnetlink.h> 23 #include <linux/if_ether.h> 24 #include <linux/slab.h> 25 #include <net/sock.h> 26 #include <linux/if_vlan.h> 27 28 #include "br_private.h" 29 30 /* 31 * Determine initial path cost based on speed. 32 * using recommendations from 802.1d standard 33 * 34 * Since driver might sleep need to not be holding any locks. 35 */ 36 static int port_cost(struct net_device *dev) 37 { 38 struct ethtool_cmd ecmd; 39 40 if (!__ethtool_get_settings(dev, &ecmd)) { 41 switch (ethtool_cmd_speed(&ecmd)) { 42 case SPEED_10000: 43 return 2; 44 case SPEED_1000: 45 return 4; 46 case SPEED_100: 47 return 19; 48 case SPEED_10: 49 return 100; 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 /* Check for port carrier transitions. */ 65 void br_port_carrier_check(struct net_bridge_port *p) 66 { 67 struct net_device *dev = p->dev; 68 struct net_bridge *br = p->br; 69 70 if (!(p->flags & BR_ADMIN_COST) && 71 netif_running(dev) && netif_oper_up(dev)) 72 p->path_cost = port_cost(dev); 73 74 if (!netif_running(br->dev)) 75 return; 76 77 spin_lock_bh(&br->lock); 78 if (netif_running(dev) && netif_oper_up(dev)) { 79 if (p->state == BR_STATE_DISABLED) 80 br_stp_enable_port(p); 81 } else { 82 if (p->state != BR_STATE_DISABLED) 83 br_stp_disable_port(p); 84 } 85 spin_unlock_bh(&br->lock); 86 } 87 88 static void br_port_set_promisc(struct net_bridge_port *p) 89 { 90 int err = 0; 91 92 if (br_promisc_port(p)) 93 return; 94 95 err = dev_set_promiscuity(p->dev, 1); 96 if (err) 97 return; 98 99 br_fdb_unsync_static(p->br, p); 100 p->flags |= BR_PROMISC; 101 } 102 103 static void br_port_clear_promisc(struct net_bridge_port *p) 104 { 105 int err; 106 107 /* Check if the port is already non-promisc or if it doesn't 108 * support UNICAST filtering. Without unicast filtering support 109 * we'll end up re-enabling promisc mode anyway, so just check for 110 * it here. 111 */ 112 if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT)) 113 return; 114 115 /* Since we'll be clearing the promisc mode, program the port 116 * first so that we don't have interruption in traffic. 117 */ 118 err = br_fdb_sync_static(p->br, p); 119 if (err) 120 return; 121 122 dev_set_promiscuity(p->dev, -1); 123 p->flags &= ~BR_PROMISC; 124 } 125 126 /* When a port is added or removed or when certain port flags 127 * change, this function is called to automatically manage 128 * promiscuity setting of all the bridge ports. We are always called 129 * under RTNL so can skip using rcu primitives. 130 */ 131 void br_manage_promisc(struct net_bridge *br) 132 { 133 struct net_bridge_port *p; 134 bool set_all = false; 135 136 /* If vlan filtering is disabled or bridge interface is placed 137 * into promiscuous mode, place all ports in promiscuous mode. 138 */ 139 if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br)) 140 set_all = true; 141 142 list_for_each_entry(p, &br->port_list, list) { 143 if (set_all) { 144 br_port_set_promisc(p); 145 } else { 146 /* If the number of auto-ports is <= 1, then all other 147 * ports will have their output configuration 148 * statically specified through fdbs. Since ingress 149 * on the auto-port becomes forwarding/egress to other 150 * ports and egress configuration is statically known, 151 * we can say that ingress configuration of the 152 * auto-port is also statically known. 153 * This lets us disable promiscuous mode and write 154 * this config to hw. 155 */ 156 if (br->auto_cnt == 0 || 157 (br->auto_cnt == 1 && br_auto_port(p))) 158 br_port_clear_promisc(p); 159 else 160 br_port_set_promisc(p); 161 } 162 } 163 } 164 165 static void nbp_update_port_count(struct net_bridge *br) 166 { 167 struct net_bridge_port *p; 168 u32 cnt = 0; 169 170 list_for_each_entry(p, &br->port_list, list) { 171 if (br_auto_port(p)) 172 cnt++; 173 } 174 if (br->auto_cnt != cnt) { 175 br->auto_cnt = cnt; 176 br_manage_promisc(br); 177 } 178 } 179 180 static void nbp_delete_promisc(struct net_bridge_port *p) 181 { 182 /* If port is currently promiscuous, unset promiscuity. 183 * Otherwise, it is a static port so remove all addresses 184 * from it. 185 */ 186 dev_set_allmulti(p->dev, -1); 187 if (br_promisc_port(p)) 188 dev_set_promiscuity(p->dev, -1); 189 else 190 br_fdb_unsync_static(p->br, p); 191 } 192 193 static void release_nbp(struct kobject *kobj) 194 { 195 struct net_bridge_port *p 196 = container_of(kobj, struct net_bridge_port, kobj); 197 kfree(p); 198 } 199 200 static struct kobj_type brport_ktype = { 201 #ifdef CONFIG_SYSFS 202 .sysfs_ops = &brport_sysfs_ops, 203 #endif 204 .release = release_nbp, 205 }; 206 207 static void destroy_nbp(struct net_bridge_port *p) 208 { 209 struct net_device *dev = p->dev; 210 211 p->br = NULL; 212 p->dev = NULL; 213 dev_put(dev); 214 215 kobject_put(&p->kobj); 216 } 217 218 static void destroy_nbp_rcu(struct rcu_head *head) 219 { 220 struct net_bridge_port *p = 221 container_of(head, struct net_bridge_port, rcu); 222 destroy_nbp(p); 223 } 224 225 /* Delete port(interface) from bridge is done in two steps. 226 * via RCU. First step, marks device as down. That deletes 227 * all the timers and stops new packets from flowing through. 228 * 229 * Final cleanup doesn't occur until after all CPU's finished 230 * processing packets. 231 * 232 * Protected from multiple admin operations by RTNL mutex 233 */ 234 static void del_nbp(struct net_bridge_port *p) 235 { 236 struct net_bridge *br = p->br; 237 struct net_device *dev = p->dev; 238 239 sysfs_remove_link(br->ifobj, p->dev->name); 240 241 nbp_delete_promisc(p); 242 243 spin_lock_bh(&br->lock); 244 br_stp_disable_port(p); 245 spin_unlock_bh(&br->lock); 246 247 br_ifinfo_notify(RTM_DELLINK, p); 248 249 list_del_rcu(&p->list); 250 251 nbp_vlan_flush(p); 252 br_fdb_delete_by_port(br, p, 1); 253 nbp_update_port_count(br); 254 255 dev->priv_flags &= ~IFF_BRIDGE_PORT; 256 257 netdev_rx_handler_unregister(dev); 258 259 netdev_upper_dev_unlink(dev, br->dev); 260 261 br_multicast_del_port(p); 262 263 kobject_uevent(&p->kobj, KOBJ_REMOVE); 264 kobject_del(&p->kobj); 265 266 br_netpoll_disable(p); 267 268 call_rcu(&p->rcu, destroy_nbp_rcu); 269 } 270 271 /* Delete bridge device */ 272 void br_dev_delete(struct net_device *dev, struct list_head *head) 273 { 274 struct net_bridge *br = netdev_priv(dev); 275 struct net_bridge_port *p, *n; 276 277 list_for_each_entry_safe(p, n, &br->port_list, list) { 278 del_nbp(p); 279 } 280 281 br_fdb_delete_by_port(br, NULL, 1); 282 283 br_vlan_flush(br); 284 del_timer_sync(&br->gc_timer); 285 286 br_sysfs_delbr(br->dev); 287 unregister_netdevice_queue(br->dev, head); 288 } 289 290 /* find an available port number */ 291 static int find_portno(struct net_bridge *br) 292 { 293 int index; 294 struct net_bridge_port *p; 295 unsigned long *inuse; 296 297 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 298 GFP_KERNEL); 299 if (!inuse) 300 return -ENOMEM; 301 302 set_bit(0, inuse); /* zero is reserved */ 303 list_for_each_entry(p, &br->port_list, list) { 304 set_bit(p->port_no, inuse); 305 } 306 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 307 kfree(inuse); 308 309 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 310 } 311 312 /* called with RTNL but without bridge lock */ 313 static struct net_bridge_port *new_nbp(struct net_bridge *br, 314 struct net_device *dev) 315 { 316 int index; 317 struct net_bridge_port *p; 318 319 index = find_portno(br); 320 if (index < 0) 321 return ERR_PTR(index); 322 323 p = kzalloc(sizeof(*p), GFP_KERNEL); 324 if (p == NULL) 325 return ERR_PTR(-ENOMEM); 326 327 p->br = br; 328 dev_hold(dev); 329 p->dev = dev; 330 p->path_cost = port_cost(dev); 331 p->priority = 0x8000 >> BR_PORT_BITS; 332 p->port_no = index; 333 p->flags = BR_LEARNING | BR_FLOOD; 334 br_init_port(p); 335 p->state = BR_STATE_DISABLED; 336 br_stp_port_timer_init(p); 337 br_multicast_add_port(p); 338 339 return p; 340 } 341 342 int br_add_bridge(struct net *net, const char *name) 343 { 344 struct net_device *dev; 345 int res; 346 347 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN, 348 br_dev_setup); 349 350 if (!dev) 351 return -ENOMEM; 352 353 dev_net_set(dev, net); 354 dev->rtnl_link_ops = &br_link_ops; 355 356 res = register_netdev(dev); 357 if (res) 358 free_netdev(dev); 359 return res; 360 } 361 362 int br_del_bridge(struct net *net, const char *name) 363 { 364 struct net_device *dev; 365 int ret = 0; 366 367 rtnl_lock(); 368 dev = __dev_get_by_name(net, name); 369 if (dev == NULL) 370 ret = -ENXIO; /* Could not find device */ 371 372 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 373 /* Attempt to delete non bridge device! */ 374 ret = -EPERM; 375 } 376 377 else if (dev->flags & IFF_UP) { 378 /* Not shutdown yet. */ 379 ret = -EBUSY; 380 } 381 382 else 383 br_dev_delete(dev, NULL); 384 385 rtnl_unlock(); 386 return ret; 387 } 388 389 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 390 int br_min_mtu(const struct net_bridge *br) 391 { 392 const struct net_bridge_port *p; 393 int mtu = 0; 394 395 ASSERT_RTNL(); 396 397 if (list_empty(&br->port_list)) 398 mtu = ETH_DATA_LEN; 399 else { 400 list_for_each_entry(p, &br->port_list, list) { 401 if (!mtu || p->dev->mtu < mtu) 402 mtu = p->dev->mtu; 403 } 404 } 405 return mtu; 406 } 407 408 /* 409 * Recomputes features using slave's features 410 */ 411 netdev_features_t br_features_recompute(struct net_bridge *br, 412 netdev_features_t features) 413 { 414 struct net_bridge_port *p; 415 netdev_features_t mask; 416 417 if (list_empty(&br->port_list)) 418 return features; 419 420 mask = features; 421 features &= ~NETIF_F_ONE_FOR_ALL; 422 423 list_for_each_entry(p, &br->port_list, list) { 424 features = netdev_increment_features(features, 425 p->dev->features, mask); 426 } 427 428 return features; 429 } 430 431 /* called with RTNL */ 432 int br_add_if(struct net_bridge *br, struct net_device *dev) 433 { 434 struct net_bridge_port *p; 435 int err = 0; 436 bool changed_addr; 437 438 /* Don't allow bridging non-ethernet like devices */ 439 if ((dev->flags & IFF_LOOPBACK) || 440 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 441 !is_valid_ether_addr(dev->dev_addr)) 442 return -EINVAL; 443 444 /* No bridging of bridges */ 445 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 446 return -ELOOP; 447 448 /* Device is already being bridged */ 449 if (br_port_exists(dev)) 450 return -EBUSY; 451 452 /* No bridging devices that dislike that (e.g. wireless) */ 453 if (dev->priv_flags & IFF_DONT_BRIDGE) 454 return -EOPNOTSUPP; 455 456 p = new_nbp(br, dev); 457 if (IS_ERR(p)) 458 return PTR_ERR(p); 459 460 call_netdevice_notifiers(NETDEV_JOIN, dev); 461 462 err = dev_set_allmulti(dev, 1); 463 if (err) 464 goto put_back; 465 466 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 467 SYSFS_BRIDGE_PORT_ATTR); 468 if (err) 469 goto err1; 470 471 err = br_sysfs_addif(p); 472 if (err) 473 goto err2; 474 475 err = br_netpoll_enable(p); 476 if (err) 477 goto err3; 478 479 err = netdev_master_upper_dev_link(dev, br->dev); 480 if (err) 481 goto err4; 482 483 err = netdev_rx_handler_register(dev, br_handle_frame, p); 484 if (err) 485 goto err5; 486 487 dev->priv_flags |= IFF_BRIDGE_PORT; 488 489 dev_disable_lro(dev); 490 491 list_add_rcu(&p->list, &br->port_list); 492 493 nbp_update_port_count(br); 494 495 netdev_update_features(br->dev); 496 497 if (br->dev->needed_headroom < dev->needed_headroom) 498 br->dev->needed_headroom = dev->needed_headroom; 499 500 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 501 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 502 503 spin_lock_bh(&br->lock); 504 changed_addr = br_stp_recalculate_bridge_id(br); 505 506 if (netif_running(dev) && netif_oper_up(dev) && 507 (br->dev->flags & IFF_UP)) 508 br_stp_enable_port(p); 509 spin_unlock_bh(&br->lock); 510 511 br_ifinfo_notify(RTM_NEWLINK, p); 512 513 if (changed_addr) 514 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 515 516 dev_set_mtu(br->dev, br_min_mtu(br)); 517 518 kobject_uevent(&p->kobj, KOBJ_ADD); 519 520 return 0; 521 522 err5: 523 netdev_upper_dev_unlink(dev, br->dev); 524 err4: 525 br_netpoll_disable(p); 526 err3: 527 sysfs_remove_link(br->ifobj, p->dev->name); 528 err2: 529 kobject_put(&p->kobj); 530 p = NULL; /* kobject_put frees */ 531 err1: 532 dev_set_allmulti(dev, -1); 533 put_back: 534 dev_put(dev); 535 kfree(p); 536 return err; 537 } 538 539 /* called with RTNL */ 540 int br_del_if(struct net_bridge *br, struct net_device *dev) 541 { 542 struct net_bridge_port *p; 543 bool changed_addr; 544 545 p = br_port_get_rtnl(dev); 546 if (!p || p->br != br) 547 return -EINVAL; 548 549 /* Since more than one interface can be attached to a bridge, 550 * there still maybe an alternate path for netconsole to use; 551 * therefore there is no reason for a NETDEV_RELEASE event. 552 */ 553 del_nbp(p); 554 555 spin_lock_bh(&br->lock); 556 changed_addr = br_stp_recalculate_bridge_id(br); 557 spin_unlock_bh(&br->lock); 558 559 if (changed_addr) 560 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 561 562 netdev_update_features(br->dev); 563 564 return 0; 565 } 566 567 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask) 568 { 569 struct net_bridge *br = p->br; 570 571 if (mask & BR_AUTO_MASK) 572 nbp_update_port_count(br); 573 } 574