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 #include <net/switchdev.h> 28 29 #include "br_private.h" 30 31 /* 32 * Determine initial path cost based on speed. 33 * using recommendations from 802.1d standard 34 * 35 * Since driver might sleep need to not be holding any locks. 36 */ 37 static int port_cost(struct net_device *dev) 38 { 39 struct ethtool_cmd ecmd; 40 41 if (!__ethtool_get_settings(dev, &ecmd)) { 42 switch (ethtool_cmd_speed(&ecmd)) { 43 case SPEED_10000: 44 return 2; 45 case SPEED_1000: 46 return 4; 47 case SPEED_100: 48 return 19; 49 case SPEED_10: 50 return 100; 51 } 52 } 53 54 /* Old silly heuristics based on name */ 55 if (!strncmp(dev->name, "lec", 3)) 56 return 7; 57 58 if (!strncmp(dev->name, "plip", 4)) 59 return 2500; 60 61 return 100; /* assume old 10Mbps */ 62 } 63 64 65 /* Check for port carrier transitions. */ 66 void br_port_carrier_check(struct net_bridge_port *p) 67 { 68 struct net_device *dev = p->dev; 69 struct net_bridge *br = p->br; 70 71 if (!(p->flags & BR_ADMIN_COST) && 72 netif_running(dev) && netif_oper_up(dev)) 73 p->path_cost = port_cost(dev); 74 75 if (!netif_running(br->dev)) 76 return; 77 78 spin_lock_bh(&br->lock); 79 if (netif_running(dev) && netif_oper_up(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 static void br_port_set_promisc(struct net_bridge_port *p) 90 { 91 int err = 0; 92 93 if (br_promisc_port(p)) 94 return; 95 96 err = dev_set_promiscuity(p->dev, 1); 97 if (err) 98 return; 99 100 br_fdb_unsync_static(p->br, p); 101 p->flags |= BR_PROMISC; 102 } 103 104 static void br_port_clear_promisc(struct net_bridge_port *p) 105 { 106 int err; 107 108 /* Check if the port is already non-promisc or if it doesn't 109 * support UNICAST filtering. Without unicast filtering support 110 * we'll end up re-enabling promisc mode anyway, so just check for 111 * it here. 112 */ 113 if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT)) 114 return; 115 116 /* Since we'll be clearing the promisc mode, program the port 117 * first so that we don't have interruption in traffic. 118 */ 119 err = br_fdb_sync_static(p->br, p); 120 if (err) 121 return; 122 123 dev_set_promiscuity(p->dev, -1); 124 p->flags &= ~BR_PROMISC; 125 } 126 127 /* When a port is added or removed or when certain port flags 128 * change, this function is called to automatically manage 129 * promiscuity setting of all the bridge ports. We are always called 130 * under RTNL so can skip using rcu primitives. 131 */ 132 void br_manage_promisc(struct net_bridge *br) 133 { 134 struct net_bridge_port *p; 135 bool set_all = false; 136 137 /* If vlan filtering is disabled or bridge interface is placed 138 * into promiscuous mode, place all ports in promiscuous mode. 139 */ 140 if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br)) 141 set_all = true; 142 143 list_for_each_entry(p, &br->port_list, list) { 144 if (set_all) { 145 br_port_set_promisc(p); 146 } else { 147 /* If the number of auto-ports is <= 1, then all other 148 * ports will have their output configuration 149 * statically specified through fdbs. Since ingress 150 * on the auto-port becomes forwarding/egress to other 151 * ports and egress configuration is statically known, 152 * we can say that ingress configuration of the 153 * auto-port is also statically known. 154 * This lets us disable promiscuous mode and write 155 * this config to hw. 156 */ 157 if (br->auto_cnt == 0 || 158 (br->auto_cnt == 1 && br_auto_port(p))) 159 br_port_clear_promisc(p); 160 else 161 br_port_set_promisc(p); 162 } 163 } 164 } 165 166 static void nbp_update_port_count(struct net_bridge *br) 167 { 168 struct net_bridge_port *p; 169 u32 cnt = 0; 170 171 list_for_each_entry(p, &br->port_list, list) { 172 if (br_auto_port(p)) 173 cnt++; 174 } 175 if (br->auto_cnt != cnt) { 176 br->auto_cnt = cnt; 177 br_manage_promisc(br); 178 } 179 } 180 181 static void nbp_delete_promisc(struct net_bridge_port *p) 182 { 183 /* If port is currently promiscuous, unset promiscuity. 184 * Otherwise, it is a static port so remove all addresses 185 * from it. 186 */ 187 dev_set_allmulti(p->dev, -1); 188 if (br_promisc_port(p)) 189 dev_set_promiscuity(p->dev, -1); 190 else 191 br_fdb_unsync_static(p->br, p); 192 } 193 194 static void release_nbp(struct kobject *kobj) 195 { 196 struct net_bridge_port *p 197 = container_of(kobj, struct net_bridge_port, kobj); 198 kfree(p); 199 } 200 201 static struct kobj_type brport_ktype = { 202 #ifdef CONFIG_SYSFS 203 .sysfs_ops = &brport_sysfs_ops, 204 #endif 205 .release = release_nbp, 206 }; 207 208 static void destroy_nbp(struct net_bridge_port *p) 209 { 210 struct net_device *dev = p->dev; 211 212 p->br = NULL; 213 p->dev = NULL; 214 dev_put(dev); 215 216 kobject_put(&p->kobj); 217 } 218 219 static void destroy_nbp_rcu(struct rcu_head *head) 220 { 221 struct net_bridge_port *p = 222 container_of(head, struct net_bridge_port, rcu); 223 destroy_nbp(p); 224 } 225 226 /* Delete port(interface) from bridge is done in two steps. 227 * via RCU. First step, marks device as down. That deletes 228 * all the timers and stops new packets from flowing through. 229 * 230 * Final cleanup doesn't occur until after all CPU's finished 231 * processing packets. 232 * 233 * Protected from multiple admin operations by RTNL mutex 234 */ 235 static void del_nbp(struct net_bridge_port *p) 236 { 237 struct net_bridge *br = p->br; 238 struct net_device *dev = p->dev; 239 240 sysfs_remove_link(br->ifobj, p->dev->name); 241 242 nbp_delete_promisc(p); 243 244 spin_lock_bh(&br->lock); 245 br_stp_disable_port(p); 246 spin_unlock_bh(&br->lock); 247 248 br_ifinfo_notify(RTM_DELLINK, p); 249 250 list_del_rcu(&p->list); 251 252 nbp_vlan_flush(p); 253 br_fdb_delete_by_port(br, p, 0, 1); 254 switchdev_deferred_process(); 255 256 nbp_update_port_count(br); 257 258 netdev_upper_dev_unlink(dev, br->dev); 259 260 dev->priv_flags &= ~IFF_BRIDGE_PORT; 261 262 netdev_rx_handler_unregister(dev); 263 264 br_multicast_del_port(p); 265 266 kobject_uevent(&p->kobj, KOBJ_REMOVE); 267 kobject_del(&p->kobj); 268 269 br_netpoll_disable(p); 270 271 call_rcu(&p->rcu, destroy_nbp_rcu); 272 } 273 274 /* Delete bridge device */ 275 void br_dev_delete(struct net_device *dev, struct list_head *head) 276 { 277 struct net_bridge *br = netdev_priv(dev); 278 struct net_bridge_port *p, *n; 279 280 list_for_each_entry_safe(p, n, &br->port_list, list) { 281 del_nbp(p); 282 } 283 284 br_fdb_delete_by_port(br, NULL, 0, 1); 285 286 br_vlan_flush(br); 287 br_multicast_dev_del(br); 288 del_timer_sync(&br->gc_timer); 289 290 br_sysfs_delbr(br->dev); 291 unregister_netdevice_queue(br->dev, head); 292 } 293 294 /* find an available port number */ 295 static int find_portno(struct net_bridge *br) 296 { 297 int index; 298 struct net_bridge_port *p; 299 unsigned long *inuse; 300 301 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 302 GFP_KERNEL); 303 if (!inuse) 304 return -ENOMEM; 305 306 set_bit(0, inuse); /* zero is reserved */ 307 list_for_each_entry(p, &br->port_list, list) { 308 set_bit(p->port_no, inuse); 309 } 310 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 311 kfree(inuse); 312 313 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 314 } 315 316 /* called with RTNL but without bridge lock */ 317 static struct net_bridge_port *new_nbp(struct net_bridge *br, 318 struct net_device *dev) 319 { 320 int index; 321 struct net_bridge_port *p; 322 323 index = find_portno(br); 324 if (index < 0) 325 return ERR_PTR(index); 326 327 p = kzalloc(sizeof(*p), GFP_KERNEL); 328 if (p == NULL) 329 return ERR_PTR(-ENOMEM); 330 331 p->br = br; 332 dev_hold(dev); 333 p->dev = dev; 334 p->path_cost = port_cost(dev); 335 p->priority = 0x8000 >> BR_PORT_BITS; 336 p->port_no = index; 337 p->flags = BR_LEARNING | BR_FLOOD; 338 br_init_port(p); 339 br_set_state(p, BR_STATE_DISABLED); 340 br_stp_port_timer_init(p); 341 br_multicast_add_port(p); 342 343 return p; 344 } 345 346 int br_add_bridge(struct net *net, const char *name) 347 { 348 struct net_device *dev; 349 int res; 350 351 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN, 352 br_dev_setup); 353 354 if (!dev) 355 return -ENOMEM; 356 357 dev_net_set(dev, net); 358 dev->rtnl_link_ops = &br_link_ops; 359 360 res = register_netdev(dev); 361 if (res) 362 free_netdev(dev); 363 return res; 364 } 365 366 int br_del_bridge(struct net *net, const char *name) 367 { 368 struct net_device *dev; 369 int ret = 0; 370 371 rtnl_lock(); 372 dev = __dev_get_by_name(net, name); 373 if (dev == NULL) 374 ret = -ENXIO; /* Could not find device */ 375 376 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 377 /* Attempt to delete non bridge device! */ 378 ret = -EPERM; 379 } 380 381 else if (dev->flags & IFF_UP) { 382 /* Not shutdown yet. */ 383 ret = -EBUSY; 384 } 385 386 else 387 br_dev_delete(dev, NULL); 388 389 rtnl_unlock(); 390 return ret; 391 } 392 393 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 394 int br_min_mtu(const struct net_bridge *br) 395 { 396 const struct net_bridge_port *p; 397 int mtu = 0; 398 399 ASSERT_RTNL(); 400 401 if (list_empty(&br->port_list)) 402 mtu = ETH_DATA_LEN; 403 else { 404 list_for_each_entry(p, &br->port_list, list) { 405 if (!mtu || p->dev->mtu < mtu) 406 mtu = p->dev->mtu; 407 } 408 } 409 return mtu; 410 } 411 412 /* 413 * Recomputes features using slave's features 414 */ 415 netdev_features_t br_features_recompute(struct net_bridge *br, 416 netdev_features_t features) 417 { 418 struct net_bridge_port *p; 419 netdev_features_t mask; 420 421 if (list_empty(&br->port_list)) 422 return features; 423 424 mask = features; 425 features &= ~NETIF_F_ONE_FOR_ALL; 426 427 list_for_each_entry(p, &br->port_list, list) { 428 features = netdev_increment_features(features, 429 p->dev->features, mask); 430 } 431 features = netdev_add_tso_features(features, mask); 432 433 return features; 434 } 435 436 /* called with RTNL */ 437 int br_add_if(struct net_bridge *br, struct net_device *dev) 438 { 439 struct net_bridge_port *p; 440 int err = 0; 441 bool changed_addr; 442 443 /* Don't allow bridging non-ethernet like devices, or DSA-enabled 444 * master network devices since the bridge layer rx_handler prevents 445 * the DSA fake ethertype handler to be invoked, so we do not strip off 446 * the DSA switch tag protocol header and the bridge layer just return 447 * RX_HANDLER_CONSUMED, stopping RX processing for these frames. 448 */ 449 if ((dev->flags & IFF_LOOPBACK) || 450 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 451 !is_valid_ether_addr(dev->dev_addr) || 452 netdev_uses_dsa(dev)) 453 return -EINVAL; 454 455 /* No bridging of bridges */ 456 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 457 return -ELOOP; 458 459 /* Device is already being bridged */ 460 if (br_port_exists(dev)) 461 return -EBUSY; 462 463 /* No bridging devices that dislike that (e.g. wireless) */ 464 if (dev->priv_flags & IFF_DONT_BRIDGE) 465 return -EOPNOTSUPP; 466 467 p = new_nbp(br, dev); 468 if (IS_ERR(p)) 469 return PTR_ERR(p); 470 471 call_netdevice_notifiers(NETDEV_JOIN, dev); 472 473 err = dev_set_allmulti(dev, 1); 474 if (err) 475 goto put_back; 476 477 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 478 SYSFS_BRIDGE_PORT_ATTR); 479 if (err) 480 goto err1; 481 482 err = br_sysfs_addif(p); 483 if (err) 484 goto err2; 485 486 err = br_netpoll_enable(p); 487 if (err) 488 goto err3; 489 490 err = netdev_rx_handler_register(dev, br_handle_frame, p); 491 if (err) 492 goto err4; 493 494 dev->priv_flags |= IFF_BRIDGE_PORT; 495 496 err = netdev_master_upper_dev_link(dev, br->dev); 497 if (err) 498 goto err5; 499 500 dev_disable_lro(dev); 501 502 list_add_rcu(&p->list, &br->port_list); 503 504 nbp_update_port_count(br); 505 506 netdev_update_features(br->dev); 507 508 if (br->dev->needed_headroom < dev->needed_headroom) 509 br->dev->needed_headroom = dev->needed_headroom; 510 511 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 512 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 513 514 if (nbp_vlan_init(p)) 515 netdev_err(dev, "failed to initialize vlan filtering on this port\n"); 516 517 spin_lock_bh(&br->lock); 518 changed_addr = br_stp_recalculate_bridge_id(br); 519 520 if (netif_running(dev) && netif_oper_up(dev) && 521 (br->dev->flags & IFF_UP)) 522 br_stp_enable_port(p); 523 spin_unlock_bh(&br->lock); 524 525 br_ifinfo_notify(RTM_NEWLINK, p); 526 527 if (changed_addr) 528 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 529 530 dev_set_mtu(br->dev, br_min_mtu(br)); 531 532 kobject_uevent(&p->kobj, KOBJ_ADD); 533 534 return 0; 535 536 err5: 537 dev->priv_flags &= ~IFF_BRIDGE_PORT; 538 netdev_rx_handler_unregister(dev); 539 err4: 540 br_netpoll_disable(p); 541 err3: 542 sysfs_remove_link(br->ifobj, p->dev->name); 543 err2: 544 kobject_put(&p->kobj); 545 p = NULL; /* kobject_put frees */ 546 err1: 547 dev_set_allmulti(dev, -1); 548 put_back: 549 dev_put(dev); 550 kfree(p); 551 return err; 552 } 553 554 /* called with RTNL */ 555 int br_del_if(struct net_bridge *br, struct net_device *dev) 556 { 557 struct net_bridge_port *p; 558 bool changed_addr; 559 560 p = br_port_get_rtnl(dev); 561 if (!p || p->br != br) 562 return -EINVAL; 563 564 /* Since more than one interface can be attached to a bridge, 565 * there still maybe an alternate path for netconsole to use; 566 * therefore there is no reason for a NETDEV_RELEASE event. 567 */ 568 del_nbp(p); 569 570 dev_set_mtu(br->dev, br_min_mtu(br)); 571 572 spin_lock_bh(&br->lock); 573 changed_addr = br_stp_recalculate_bridge_id(br); 574 spin_unlock_bh(&br->lock); 575 576 if (changed_addr) 577 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 578 579 netdev_update_features(br->dev); 580 581 return 0; 582 } 583 584 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask) 585 { 586 struct net_bridge *br = p->br; 587 588 if (mask & BR_AUTO_MASK) 589 nbp_update_port_count(br); 590 } 591