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/dsa.h> 26 #include <net/sock.h> 27 #include <linux/if_vlan.h> 28 #include <net/switchdev.h> 29 30 #include "br_private.h" 31 32 /* 33 * Determine initial path cost based on speed. 34 * using recommendations from 802.1d standard 35 * 36 * Since driver might sleep need to not be holding any locks. 37 */ 38 static int port_cost(struct net_device *dev) 39 { 40 struct ethtool_link_ksettings ecmd; 41 42 if (!__ethtool_get_link_ksettings(dev, &ecmd)) { 43 switch (ecmd.base.speed) { 44 case SPEED_10000: 45 return 2; 46 case SPEED_1000: 47 return 4; 48 case SPEED_100: 49 return 19; 50 case SPEED_10: 51 return 100; 52 } 53 } 54 55 /* Old silly heuristics based on name */ 56 if (!strncmp(dev->name, "lec", 3)) 57 return 7; 58 59 if (!strncmp(dev->name, "plip", 4)) 60 return 2500; 61 62 return 100; /* assume old 10Mbps */ 63 } 64 65 66 /* Check for port carrier transitions. */ 67 void br_port_carrier_check(struct net_bridge_port *p) 68 { 69 struct net_device *dev = p->dev; 70 struct net_bridge *br = p->br; 71 72 if (!(p->flags & BR_ADMIN_COST) && 73 netif_running(dev) && netif_oper_up(dev)) 74 p->path_cost = port_cost(dev); 75 76 if (!netif_running(br->dev)) 77 return; 78 79 spin_lock_bh(&br->lock); 80 if (netif_running(dev) && netif_oper_up(dev)) { 81 if (p->state == BR_STATE_DISABLED) 82 br_stp_enable_port(p); 83 } else { 84 if (p->state != BR_STATE_DISABLED) 85 br_stp_disable_port(p); 86 } 87 spin_unlock_bh(&br->lock); 88 } 89 90 static void br_port_set_promisc(struct net_bridge_port *p) 91 { 92 int err = 0; 93 94 if (br_promisc_port(p)) 95 return; 96 97 err = dev_set_promiscuity(p->dev, 1); 98 if (err) 99 return; 100 101 br_fdb_unsync_static(p->br, p); 102 p->flags |= BR_PROMISC; 103 } 104 105 static void br_port_clear_promisc(struct net_bridge_port *p) 106 { 107 int err; 108 109 /* Check if the port is already non-promisc or if it doesn't 110 * support UNICAST filtering. Without unicast filtering support 111 * we'll end up re-enabling promisc mode anyway, so just check for 112 * it here. 113 */ 114 if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT)) 115 return; 116 117 /* Since we'll be clearing the promisc mode, program the port 118 * first so that we don't have interruption in traffic. 119 */ 120 err = br_fdb_sync_static(p->br, p); 121 if (err) 122 return; 123 124 dev_set_promiscuity(p->dev, -1); 125 p->flags &= ~BR_PROMISC; 126 } 127 128 /* When a port is added or removed or when certain port flags 129 * change, this function is called to automatically manage 130 * promiscuity setting of all the bridge ports. We are always called 131 * under RTNL so can skip using rcu primitives. 132 */ 133 void br_manage_promisc(struct net_bridge *br) 134 { 135 struct net_bridge_port *p; 136 bool set_all = false; 137 138 /* If vlan filtering is disabled or bridge interface is placed 139 * into promiscuous mode, place all ports in promiscuous mode. 140 */ 141 if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev)) 142 set_all = true; 143 144 list_for_each_entry(p, &br->port_list, list) { 145 if (set_all) { 146 br_port_set_promisc(p); 147 } else { 148 /* If the number of auto-ports is <= 1, then all other 149 * ports will have their output configuration 150 * statically specified through fdbs. Since ingress 151 * on the auto-port becomes forwarding/egress to other 152 * ports and egress configuration is statically known, 153 * we can say that ingress configuration of the 154 * auto-port is also statically known. 155 * This lets us disable promiscuous mode and write 156 * this config to hw. 157 */ 158 if (br->auto_cnt == 0 || 159 (br->auto_cnt == 1 && br_auto_port(p))) 160 br_port_clear_promisc(p); 161 else 162 br_port_set_promisc(p); 163 } 164 } 165 } 166 167 static void nbp_update_port_count(struct net_bridge *br) 168 { 169 struct net_bridge_port *p; 170 u32 cnt = 0; 171 172 list_for_each_entry(p, &br->port_list, list) { 173 if (br_auto_port(p)) 174 cnt++; 175 } 176 if (br->auto_cnt != cnt) { 177 br->auto_cnt = cnt; 178 br_manage_promisc(br); 179 } 180 } 181 182 static void nbp_delete_promisc(struct net_bridge_port *p) 183 { 184 /* If port is currently promiscuous, unset promiscuity. 185 * Otherwise, it is a static port so remove all addresses 186 * from it. 187 */ 188 dev_set_allmulti(p->dev, -1); 189 if (br_promisc_port(p)) 190 dev_set_promiscuity(p->dev, -1); 191 else 192 br_fdb_unsync_static(p->br, p); 193 } 194 195 static void release_nbp(struct kobject *kobj) 196 { 197 struct net_bridge_port *p 198 = container_of(kobj, struct net_bridge_port, kobj); 199 kfree(p); 200 } 201 202 static struct kobj_type brport_ktype = { 203 #ifdef CONFIG_SYSFS 204 .sysfs_ops = &brport_sysfs_ops, 205 #endif 206 .release = release_nbp, 207 }; 208 209 static void destroy_nbp(struct net_bridge_port *p) 210 { 211 struct net_device *dev = p->dev; 212 213 p->br = NULL; 214 p->dev = NULL; 215 dev_put(dev); 216 217 kobject_put(&p->kobj); 218 } 219 220 static void destroy_nbp_rcu(struct rcu_head *head) 221 { 222 struct net_bridge_port *p = 223 container_of(head, struct net_bridge_port, rcu); 224 destroy_nbp(p); 225 } 226 227 static unsigned get_max_headroom(struct net_bridge *br) 228 { 229 unsigned max_headroom = 0; 230 struct net_bridge_port *p; 231 232 list_for_each_entry(p, &br->port_list, list) { 233 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev); 234 235 if (dev_headroom > max_headroom) 236 max_headroom = dev_headroom; 237 } 238 239 return max_headroom; 240 } 241 242 static void update_headroom(struct net_bridge *br, int new_hr) 243 { 244 struct net_bridge_port *p; 245 246 list_for_each_entry(p, &br->port_list, list) 247 netdev_set_rx_headroom(p->dev, new_hr); 248 249 br->dev->needed_headroom = new_hr; 250 } 251 252 /* Delete port(interface) from bridge is done in two steps. 253 * via RCU. First step, marks device as down. That deletes 254 * all the timers and stops new packets from flowing through. 255 * 256 * Final cleanup doesn't occur until after all CPU's finished 257 * processing packets. 258 * 259 * Protected from multiple admin operations by RTNL mutex 260 */ 261 static void del_nbp(struct net_bridge_port *p) 262 { 263 struct net_bridge *br = p->br; 264 struct net_device *dev = p->dev; 265 266 sysfs_remove_link(br->ifobj, p->dev->name); 267 268 nbp_delete_promisc(p); 269 270 spin_lock_bh(&br->lock); 271 br_stp_disable_port(p); 272 spin_unlock_bh(&br->lock); 273 274 br_ifinfo_notify(RTM_DELLINK, NULL, p); 275 276 list_del_rcu(&p->list); 277 if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom) 278 update_headroom(br, get_max_headroom(br)); 279 netdev_reset_rx_headroom(dev); 280 281 nbp_vlan_flush(p); 282 br_fdb_delete_by_port(br, p, 0, 1); 283 switchdev_deferred_process(); 284 285 nbp_update_port_count(br); 286 287 netdev_upper_dev_unlink(dev, br->dev); 288 289 dev->priv_flags &= ~IFF_BRIDGE_PORT; 290 291 netdev_rx_handler_unregister(dev); 292 293 br_multicast_del_port(p); 294 295 kobject_uevent(&p->kobj, KOBJ_REMOVE); 296 kobject_del(&p->kobj); 297 298 br_netpoll_disable(p); 299 300 call_rcu(&p->rcu, destroy_nbp_rcu); 301 } 302 303 /* Delete bridge device */ 304 void br_dev_delete(struct net_device *dev, struct list_head *head) 305 { 306 struct net_bridge *br = netdev_priv(dev); 307 struct net_bridge_port *p, *n; 308 309 list_for_each_entry_safe(p, n, &br->port_list, list) { 310 del_nbp(p); 311 } 312 313 br_recalculate_neigh_suppress_enabled(br); 314 315 br_fdb_delete_by_port(br, NULL, 0, 1); 316 317 cancel_delayed_work_sync(&br->gc_work); 318 319 br_sysfs_delbr(br->dev); 320 unregister_netdevice_queue(br->dev, head); 321 } 322 323 /* find an available port number */ 324 static int find_portno(struct net_bridge *br) 325 { 326 int index; 327 struct net_bridge_port *p; 328 unsigned long *inuse; 329 330 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 331 GFP_KERNEL); 332 if (!inuse) 333 return -ENOMEM; 334 335 set_bit(0, inuse); /* zero is reserved */ 336 list_for_each_entry(p, &br->port_list, list) { 337 set_bit(p->port_no, inuse); 338 } 339 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 340 kfree(inuse); 341 342 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 343 } 344 345 /* called with RTNL but without bridge lock */ 346 static struct net_bridge_port *new_nbp(struct net_bridge *br, 347 struct net_device *dev) 348 { 349 struct net_bridge_port *p; 350 int index, err; 351 352 index = find_portno(br); 353 if (index < 0) 354 return ERR_PTR(index); 355 356 p = kzalloc(sizeof(*p), GFP_KERNEL); 357 if (p == NULL) 358 return ERR_PTR(-ENOMEM); 359 360 p->br = br; 361 dev_hold(dev); 362 p->dev = dev; 363 p->path_cost = port_cost(dev); 364 p->priority = 0x8000 >> BR_PORT_BITS; 365 p->port_no = index; 366 p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD; 367 br_init_port(p); 368 br_set_state(p, BR_STATE_DISABLED); 369 br_stp_port_timer_init(p); 370 err = br_multicast_add_port(p); 371 if (err) { 372 dev_put(dev); 373 kfree(p); 374 p = ERR_PTR(err); 375 } 376 377 return p; 378 } 379 380 int br_add_bridge(struct net *net, const char *name) 381 { 382 struct net_device *dev; 383 int res; 384 385 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN, 386 br_dev_setup); 387 388 if (!dev) 389 return -ENOMEM; 390 391 dev_net_set(dev, net); 392 dev->rtnl_link_ops = &br_link_ops; 393 394 res = register_netdev(dev); 395 if (res) 396 free_netdev(dev); 397 return res; 398 } 399 400 int br_del_bridge(struct net *net, const char *name) 401 { 402 struct net_device *dev; 403 int ret = 0; 404 405 rtnl_lock(); 406 dev = __dev_get_by_name(net, name); 407 if (dev == NULL) 408 ret = -ENXIO; /* Could not find device */ 409 410 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 411 /* Attempt to delete non bridge device! */ 412 ret = -EPERM; 413 } 414 415 else if (dev->flags & IFF_UP) { 416 /* Not shutdown yet. */ 417 ret = -EBUSY; 418 } 419 420 else 421 br_dev_delete(dev, NULL); 422 423 rtnl_unlock(); 424 return ret; 425 } 426 427 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 428 int br_min_mtu(const struct net_bridge *br) 429 { 430 const struct net_bridge_port *p; 431 int mtu = 0; 432 433 ASSERT_RTNL(); 434 435 if (list_empty(&br->port_list)) 436 mtu = ETH_DATA_LEN; 437 else { 438 list_for_each_entry(p, &br->port_list, list) { 439 if (!mtu || p->dev->mtu < mtu) 440 mtu = p->dev->mtu; 441 } 442 } 443 return mtu; 444 } 445 446 static void br_set_gso_limits(struct net_bridge *br) 447 { 448 unsigned int gso_max_size = GSO_MAX_SIZE; 449 u16 gso_max_segs = GSO_MAX_SEGS; 450 const struct net_bridge_port *p; 451 452 list_for_each_entry(p, &br->port_list, list) { 453 gso_max_size = min(gso_max_size, p->dev->gso_max_size); 454 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs); 455 } 456 br->dev->gso_max_size = gso_max_size; 457 br->dev->gso_max_segs = gso_max_segs; 458 } 459 460 /* 461 * Recomputes features using slave's features 462 */ 463 netdev_features_t br_features_recompute(struct net_bridge *br, 464 netdev_features_t features) 465 { 466 struct net_bridge_port *p; 467 netdev_features_t mask; 468 469 if (list_empty(&br->port_list)) 470 return features; 471 472 mask = features; 473 features &= ~NETIF_F_ONE_FOR_ALL; 474 475 list_for_each_entry(p, &br->port_list, list) { 476 features = netdev_increment_features(features, 477 p->dev->features, mask); 478 } 479 features = netdev_add_tso_features(features, mask); 480 481 return features; 482 } 483 484 /* called with RTNL */ 485 int br_add_if(struct net_bridge *br, struct net_device *dev, 486 struct netlink_ext_ack *extack) 487 { 488 struct net_bridge_port *p; 489 int err = 0; 490 unsigned br_hr, dev_hr; 491 bool changed_addr; 492 493 /* Don't allow bridging non-ethernet like devices, or DSA-enabled 494 * master network devices since the bridge layer rx_handler prevents 495 * the DSA fake ethertype handler to be invoked, so we do not strip off 496 * the DSA switch tag protocol header and the bridge layer just return 497 * RX_HANDLER_CONSUMED, stopping RX processing for these frames. 498 */ 499 if ((dev->flags & IFF_LOOPBACK) || 500 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 501 !is_valid_ether_addr(dev->dev_addr) || 502 netdev_uses_dsa(dev)) 503 return -EINVAL; 504 505 /* No bridging of bridges */ 506 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) { 507 NL_SET_ERR_MSG(extack, 508 "Can not enslave a bridge to a bridge"); 509 return -ELOOP; 510 } 511 512 /* Device is already being bridged */ 513 if (br_port_exists(dev)) 514 return -EBUSY; 515 516 /* No bridging devices that dislike that (e.g. wireless) */ 517 if (dev->priv_flags & IFF_DONT_BRIDGE) { 518 NL_SET_ERR_MSG(extack, 519 "Device does not allow enslaving to a bridge"); 520 return -EOPNOTSUPP; 521 } 522 523 p = new_nbp(br, dev); 524 if (IS_ERR(p)) 525 return PTR_ERR(p); 526 527 call_netdevice_notifiers(NETDEV_JOIN, dev); 528 529 err = dev_set_allmulti(dev, 1); 530 if (err) 531 goto put_back; 532 533 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 534 SYSFS_BRIDGE_PORT_ATTR); 535 if (err) 536 goto err1; 537 538 err = br_sysfs_addif(p); 539 if (err) 540 goto err2; 541 542 err = br_netpoll_enable(p); 543 if (err) 544 goto err3; 545 546 err = netdev_rx_handler_register(dev, br_handle_frame, p); 547 if (err) 548 goto err4; 549 550 dev->priv_flags |= IFF_BRIDGE_PORT; 551 552 err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack); 553 if (err) 554 goto err5; 555 556 err = nbp_switchdev_mark_set(p); 557 if (err) 558 goto err6; 559 560 dev_disable_lro(dev); 561 562 list_add_rcu(&p->list, &br->port_list); 563 564 nbp_update_port_count(br); 565 566 netdev_update_features(br->dev); 567 568 br_hr = br->dev->needed_headroom; 569 dev_hr = netdev_get_fwd_headroom(dev); 570 if (br_hr < dev_hr) 571 update_headroom(br, dev_hr); 572 else 573 netdev_set_rx_headroom(dev, br_hr); 574 575 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 576 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 577 578 err = nbp_vlan_init(p); 579 if (err) { 580 netdev_err(dev, "failed to initialize vlan filtering on this port\n"); 581 goto err7; 582 } 583 584 spin_lock_bh(&br->lock); 585 changed_addr = br_stp_recalculate_bridge_id(br); 586 587 if (netif_running(dev) && netif_oper_up(dev) && 588 (br->dev->flags & IFF_UP)) 589 br_stp_enable_port(p); 590 spin_unlock_bh(&br->lock); 591 592 br_ifinfo_notify(RTM_NEWLINK, NULL, p); 593 594 if (changed_addr) 595 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 596 597 dev_set_mtu(br->dev, br_min_mtu(br)); 598 br_set_gso_limits(br); 599 600 kobject_uevent(&p->kobj, KOBJ_ADD); 601 602 return 0; 603 604 err7: 605 list_del_rcu(&p->list); 606 br_fdb_delete_by_port(br, p, 0, 1); 607 nbp_update_port_count(br); 608 err6: 609 netdev_upper_dev_unlink(dev, br->dev); 610 err5: 611 dev->priv_flags &= ~IFF_BRIDGE_PORT; 612 netdev_rx_handler_unregister(dev); 613 err4: 614 br_netpoll_disable(p); 615 err3: 616 sysfs_remove_link(br->ifobj, p->dev->name); 617 err2: 618 kobject_put(&p->kobj); 619 p = NULL; /* kobject_put frees */ 620 err1: 621 dev_set_allmulti(dev, -1); 622 put_back: 623 dev_put(dev); 624 kfree(p); 625 return err; 626 } 627 628 /* called with RTNL */ 629 int br_del_if(struct net_bridge *br, struct net_device *dev) 630 { 631 struct net_bridge_port *p; 632 bool changed_addr; 633 634 p = br_port_get_rtnl(dev); 635 if (!p || p->br != br) 636 return -EINVAL; 637 638 /* Since more than one interface can be attached to a bridge, 639 * there still maybe an alternate path for netconsole to use; 640 * therefore there is no reason for a NETDEV_RELEASE event. 641 */ 642 del_nbp(p); 643 644 dev_set_mtu(br->dev, br_min_mtu(br)); 645 br_set_gso_limits(br); 646 647 spin_lock_bh(&br->lock); 648 changed_addr = br_stp_recalculate_bridge_id(br); 649 spin_unlock_bh(&br->lock); 650 651 if (changed_addr) 652 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 653 654 netdev_update_features(br->dev); 655 656 return 0; 657 } 658 659 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask) 660 { 661 struct net_bridge *br = p->br; 662 663 if (mask & BR_AUTO_MASK) 664 nbp_update_port_count(br); 665 666 if (mask & BR_NEIGH_SUPPRESS) 667 br_recalculate_neigh_suppress_enabled(br); 668 } 669