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_link_ksettings ecmd; 40 41 if (!__ethtool_get_link_ksettings(dev, &ecmd)) { 42 switch (ecmd.base.speed) { 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 static unsigned get_max_headroom(struct net_bridge *br) 227 { 228 unsigned max_headroom = 0; 229 struct net_bridge_port *p; 230 231 list_for_each_entry(p, &br->port_list, list) { 232 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev); 233 234 if (dev_headroom > max_headroom) 235 max_headroom = dev_headroom; 236 } 237 238 return max_headroom; 239 } 240 241 static void update_headroom(struct net_bridge *br, int new_hr) 242 { 243 struct net_bridge_port *p; 244 245 list_for_each_entry(p, &br->port_list, list) 246 netdev_set_rx_headroom(p->dev, new_hr); 247 248 br->dev->needed_headroom = new_hr; 249 } 250 251 /* Delete port(interface) from bridge is done in two steps. 252 * via RCU. First step, marks device as down. That deletes 253 * all the timers and stops new packets from flowing through. 254 * 255 * Final cleanup doesn't occur until after all CPU's finished 256 * processing packets. 257 * 258 * Protected from multiple admin operations by RTNL mutex 259 */ 260 static void del_nbp(struct net_bridge_port *p) 261 { 262 struct net_bridge *br = p->br; 263 struct net_device *dev = p->dev; 264 265 sysfs_remove_link(br->ifobj, p->dev->name); 266 267 nbp_delete_promisc(p); 268 269 spin_lock_bh(&br->lock); 270 br_stp_disable_port(p); 271 spin_unlock_bh(&br->lock); 272 273 br_ifinfo_notify(RTM_DELLINK, p); 274 275 list_del_rcu(&p->list); 276 if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom) 277 update_headroom(br, get_max_headroom(br)); 278 netdev_reset_rx_headroom(dev); 279 280 nbp_vlan_flush(p); 281 br_fdb_delete_by_port(br, p, 0, 1); 282 switchdev_deferred_process(); 283 284 nbp_update_port_count(br); 285 286 netdev_upper_dev_unlink(dev, br->dev); 287 288 dev->priv_flags &= ~IFF_BRIDGE_PORT; 289 290 netdev_rx_handler_unregister(dev); 291 292 br_multicast_del_port(p); 293 294 kobject_uevent(&p->kobj, KOBJ_REMOVE); 295 kobject_del(&p->kobj); 296 297 br_netpoll_disable(p); 298 299 call_rcu(&p->rcu, destroy_nbp_rcu); 300 } 301 302 /* Delete bridge device */ 303 void br_dev_delete(struct net_device *dev, struct list_head *head) 304 { 305 struct net_bridge *br = netdev_priv(dev); 306 struct net_bridge_port *p, *n; 307 308 list_for_each_entry_safe(p, n, &br->port_list, list) { 309 del_nbp(p); 310 } 311 312 br_fdb_delete_by_port(br, NULL, 0, 1); 313 314 br_vlan_flush(br); 315 br_multicast_dev_del(br); 316 del_timer_sync(&br->gc_timer); 317 318 br_sysfs_delbr(br->dev); 319 unregister_netdevice_queue(br->dev, head); 320 } 321 322 /* find an available port number */ 323 static int find_portno(struct net_bridge *br) 324 { 325 int index; 326 struct net_bridge_port *p; 327 unsigned long *inuse; 328 329 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 330 GFP_KERNEL); 331 if (!inuse) 332 return -ENOMEM; 333 334 set_bit(0, inuse); /* zero is reserved */ 335 list_for_each_entry(p, &br->port_list, list) { 336 set_bit(p->port_no, inuse); 337 } 338 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 339 kfree(inuse); 340 341 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 342 } 343 344 /* called with RTNL but without bridge lock */ 345 static struct net_bridge_port *new_nbp(struct net_bridge *br, 346 struct net_device *dev) 347 { 348 struct net_bridge_port *p; 349 int index, err; 350 351 index = find_portno(br); 352 if (index < 0) 353 return ERR_PTR(index); 354 355 p = kzalloc(sizeof(*p), GFP_KERNEL); 356 if (p == NULL) 357 return ERR_PTR(-ENOMEM); 358 359 p->br = br; 360 dev_hold(dev); 361 p->dev = dev; 362 p->path_cost = port_cost(dev); 363 p->priority = 0x8000 >> BR_PORT_BITS; 364 p->port_no = index; 365 p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD; 366 br_init_port(p); 367 br_set_state(p, BR_STATE_DISABLED); 368 br_stp_port_timer_init(p); 369 err = br_multicast_add_port(p); 370 if (err) { 371 dev_put(dev); 372 kfree(p); 373 p = ERR_PTR(err); 374 } 375 376 return p; 377 } 378 379 int br_add_bridge(struct net *net, const char *name) 380 { 381 struct net_device *dev; 382 int res; 383 384 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN, 385 br_dev_setup); 386 387 if (!dev) 388 return -ENOMEM; 389 390 dev_net_set(dev, net); 391 dev->rtnl_link_ops = &br_link_ops; 392 393 res = register_netdev(dev); 394 if (res) 395 free_netdev(dev); 396 return res; 397 } 398 399 int br_del_bridge(struct net *net, const char *name) 400 { 401 struct net_device *dev; 402 int ret = 0; 403 404 rtnl_lock(); 405 dev = __dev_get_by_name(net, name); 406 if (dev == NULL) 407 ret = -ENXIO; /* Could not find device */ 408 409 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 410 /* Attempt to delete non bridge device! */ 411 ret = -EPERM; 412 } 413 414 else if (dev->flags & IFF_UP) { 415 /* Not shutdown yet. */ 416 ret = -EBUSY; 417 } 418 419 else 420 br_dev_delete(dev, NULL); 421 422 rtnl_unlock(); 423 return ret; 424 } 425 426 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 427 int br_min_mtu(const struct net_bridge *br) 428 { 429 const struct net_bridge_port *p; 430 int mtu = 0; 431 432 ASSERT_RTNL(); 433 434 if (list_empty(&br->port_list)) 435 mtu = ETH_DATA_LEN; 436 else { 437 list_for_each_entry(p, &br->port_list, list) { 438 if (!mtu || p->dev->mtu < mtu) 439 mtu = p->dev->mtu; 440 } 441 } 442 return mtu; 443 } 444 445 static void br_set_gso_limits(struct net_bridge *br) 446 { 447 unsigned int gso_max_size = GSO_MAX_SIZE; 448 u16 gso_max_segs = GSO_MAX_SEGS; 449 const struct net_bridge_port *p; 450 451 list_for_each_entry(p, &br->port_list, list) { 452 gso_max_size = min(gso_max_size, p->dev->gso_max_size); 453 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs); 454 } 455 br->dev->gso_max_size = gso_max_size; 456 br->dev->gso_max_segs = gso_max_segs; 457 } 458 459 /* 460 * Recomputes features using slave's features 461 */ 462 netdev_features_t br_features_recompute(struct net_bridge *br, 463 netdev_features_t features) 464 { 465 struct net_bridge_port *p; 466 netdev_features_t mask; 467 468 if (list_empty(&br->port_list)) 469 return features; 470 471 mask = features; 472 features &= ~NETIF_F_ONE_FOR_ALL; 473 474 list_for_each_entry(p, &br->port_list, list) { 475 features = netdev_increment_features(features, 476 p->dev->features, mask); 477 } 478 features = netdev_add_tso_features(features, mask); 479 480 return features; 481 } 482 483 /* called with RTNL */ 484 int br_add_if(struct net_bridge *br, struct net_device *dev) 485 { 486 struct net_bridge_port *p; 487 int err = 0; 488 unsigned br_hr, dev_hr; 489 bool changed_addr; 490 491 /* Don't allow bridging non-ethernet like devices, or DSA-enabled 492 * master network devices since the bridge layer rx_handler prevents 493 * the DSA fake ethertype handler to be invoked, so we do not strip off 494 * the DSA switch tag protocol header and the bridge layer just return 495 * RX_HANDLER_CONSUMED, stopping RX processing for these frames. 496 */ 497 if ((dev->flags & IFF_LOOPBACK) || 498 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 499 !is_valid_ether_addr(dev->dev_addr) || 500 netdev_uses_dsa(dev)) 501 return -EINVAL; 502 503 /* No bridging of bridges */ 504 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 505 return -ELOOP; 506 507 /* Device is already being bridged */ 508 if (br_port_exists(dev)) 509 return -EBUSY; 510 511 /* No bridging devices that dislike that (e.g. wireless) */ 512 if (dev->priv_flags & IFF_DONT_BRIDGE) 513 return -EOPNOTSUPP; 514 515 p = new_nbp(br, dev); 516 if (IS_ERR(p)) 517 return PTR_ERR(p); 518 519 call_netdevice_notifiers(NETDEV_JOIN, dev); 520 521 err = dev_set_allmulti(dev, 1); 522 if (err) 523 goto put_back; 524 525 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 526 SYSFS_BRIDGE_PORT_ATTR); 527 if (err) 528 goto err1; 529 530 err = br_sysfs_addif(p); 531 if (err) 532 goto err2; 533 534 err = br_netpoll_enable(p); 535 if (err) 536 goto err3; 537 538 err = netdev_rx_handler_register(dev, br_handle_frame, p); 539 if (err) 540 goto err4; 541 542 dev->priv_flags |= IFF_BRIDGE_PORT; 543 544 err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL); 545 if (err) 546 goto err5; 547 548 err = nbp_switchdev_mark_set(p); 549 if (err) 550 goto err6; 551 552 dev_disable_lro(dev); 553 554 list_add_rcu(&p->list, &br->port_list); 555 556 nbp_update_port_count(br); 557 558 netdev_update_features(br->dev); 559 560 br_hr = br->dev->needed_headroom; 561 dev_hr = netdev_get_fwd_headroom(dev); 562 if (br_hr < dev_hr) 563 update_headroom(br, dev_hr); 564 else 565 netdev_set_rx_headroom(dev, br_hr); 566 567 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 568 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 569 570 err = nbp_vlan_init(p); 571 if (err) { 572 netdev_err(dev, "failed to initialize vlan filtering on this port\n"); 573 goto err7; 574 } 575 576 spin_lock_bh(&br->lock); 577 changed_addr = br_stp_recalculate_bridge_id(br); 578 579 if (netif_running(dev) && netif_oper_up(dev) && 580 (br->dev->flags & IFF_UP)) 581 br_stp_enable_port(p); 582 spin_unlock_bh(&br->lock); 583 584 br_ifinfo_notify(RTM_NEWLINK, p); 585 586 if (changed_addr) 587 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 588 589 dev_set_mtu(br->dev, br_min_mtu(br)); 590 br_set_gso_limits(br); 591 592 kobject_uevent(&p->kobj, KOBJ_ADD); 593 594 return 0; 595 596 err7: 597 list_del_rcu(&p->list); 598 br_fdb_delete_by_port(br, p, 0, 1); 599 nbp_update_port_count(br); 600 err6: 601 netdev_upper_dev_unlink(dev, br->dev); 602 err5: 603 dev->priv_flags &= ~IFF_BRIDGE_PORT; 604 netdev_rx_handler_unregister(dev); 605 err4: 606 br_netpoll_disable(p); 607 err3: 608 sysfs_remove_link(br->ifobj, p->dev->name); 609 err2: 610 kobject_put(&p->kobj); 611 p = NULL; /* kobject_put frees */ 612 err1: 613 dev_set_allmulti(dev, -1); 614 put_back: 615 dev_put(dev); 616 kfree(p); 617 return err; 618 } 619 620 /* called with RTNL */ 621 int br_del_if(struct net_bridge *br, struct net_device *dev) 622 { 623 struct net_bridge_port *p; 624 bool changed_addr; 625 626 p = br_port_get_rtnl(dev); 627 if (!p || p->br != br) 628 return -EINVAL; 629 630 /* Since more than one interface can be attached to a bridge, 631 * there still maybe an alternate path for netconsole to use; 632 * therefore there is no reason for a NETDEV_RELEASE event. 633 */ 634 del_nbp(p); 635 636 dev_set_mtu(br->dev, br_min_mtu(br)); 637 br_set_gso_limits(br); 638 639 spin_lock_bh(&br->lock); 640 changed_addr = br_stp_recalculate_bridge_id(br); 641 spin_unlock_bh(&br->lock); 642 643 if (changed_addr) 644 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 645 646 netdev_update_features(br->dev); 647 648 return 0; 649 } 650 651 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask) 652 { 653 struct net_bridge *br = p->br; 654 655 if (mask & BR_AUTO_MASK) 656 nbp_update_port_count(br); 657 } 658