net/bridge/br_if.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Userspace interface
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Lennert Buytenhek               <buytenh@gnu.org>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/etherdevice.h>
  13 #include <linux/netpoll.h>
  14 #include <linux/ethtool.h>
  15 #include <linux/if_arp.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/if_ether.h>
  20 #include <linux/slab.h>
  21 #include <net/dsa.h>
  22 #include <net/sock.h>
  23 #include <linux/if_vlan.h>
  24 #include <net/switchdev.h>
  25 #include <net/net_namespace.h>
  26
  27 #include "br_private.h"
  28
  29 /*
  30  * Determine initial path cost based on speed.
  31  * using recommendations from 802.1d standard
  32  *
  33  * Since driver might sleep need to not be holding any locks.
  34  */
  35 static int port_cost(struct net_device *dev)
  36 {
  37         struct ethtool_link_ksettings ecmd;
  38
  39         if (!__ethtool_get_link_ksettings(dev, &ecmd)) {
  40                 switch (ecmd.base.speed) {
  41                 case SPEED_10000:
  42                         return 2;
  43                 case SPEED_5000:
  44                         return 3;
  45                 case SPEED_2500:
  46                         return 4;
  47                 case SPEED_1000:
  48                         return 5;
  49                 case SPEED_100:
  50                         return 19;
  51                 case SPEED_10:
  52                         return 100;
  53                 case SPEED_UNKNOWN:
  54                         return 100;
  55                 default:
  56                         if (ecmd.base.speed > SPEED_10000)
  57                                 return 1;
  58                 }
  59         }
  60
  61         /* Old silly heuristics based on name */
  62         if (!strncmp(dev->name, "lec", 3))
  63                 return 7;
  64
  65         if (!strncmp(dev->name, "plip", 4))
  66                 return 2500;
  67
  68         return 100;     /* assume old 10Mbps */
  69 }
  70
  71
  72 /* Check for port carrier transitions. */
  73 void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
  74 {
  75         struct net_device *dev = p->dev;
  76         struct net_bridge *br = p->br;
  77
  78         if (!(p->flags & BR_ADMIN_COST) &&
  79             netif_running(dev) && netif_oper_up(dev))
  80                 p->path_cost = port_cost(dev);
  81
  82         *notified = false;
  83         if (!netif_running(br->dev))
  84                 return;
  85
  86         spin_lock_bh(&br->lock);
  87         if (netif_running(dev) && netif_oper_up(dev)) {
  88                 if (p->state == BR_STATE_DISABLED) {
  89                         br_stp_enable_port(p);
  90                         *notified = true;
  91                 }
  92         } else {
  93                 if (p->state != BR_STATE_DISABLED) {
  94                         br_stp_disable_port(p);
  95                         *notified = true;
  96                 }
  97         }
  98         spin_unlock_bh(&br->lock);
  99 }
 100
 101 static void br_port_set_promisc(struct net_bridge_port *p)
 102 {
 103         int err = 0;
 104
 105         if (br_promisc_port(p))
 106                 return;
 107
 108         err = dev_set_promiscuity(p->dev, 1);
 109         if (err)
 110                 return;
 111
 112         br_fdb_unsync_static(p->br, p);
 113         p->flags |= BR_PROMISC;
 114 }
 115
 116 static void br_port_clear_promisc(struct net_bridge_port *p)
 117 {
 118         int err;
 119
 120         /* Check if the port is already non-promisc or if it doesn't
 121          * support UNICAST filtering.  Without unicast filtering support
 122          * we'll end up re-enabling promisc mode anyway, so just check for
 123          * it here.
 124          */
 125         if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
 126                 return;
 127
 128         /* Since we'll be clearing the promisc mode, program the port
 129          * first so that we don't have interruption in traffic.
 130          */
 131         err = br_fdb_sync_static(p->br, p);
 132         if (err)
 133                 return;
 134
 135         dev_set_promiscuity(p->dev, -1);
 136         p->flags &= ~BR_PROMISC;
 137 }
 138
 139 /* When a port is added or removed or when certain port flags
 140  * change, this function is called to automatically manage
 141  * promiscuity setting of all the bridge ports.  We are always called
 142  * under RTNL so can skip using rcu primitives.
 143  */
 144 void br_manage_promisc(struct net_bridge *br)
 145 {
 146         struct net_bridge_port *p;
 147         bool set_all = false;
 148
 149         /* If vlan filtering is disabled or bridge interface is placed
 150          * into promiscuous mode, place all ports in promiscuous mode.
 151          */
 152         if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
 153                 set_all = true;
 154
 155         list_for_each_entry(p, &br->port_list, list) {
 156                 if (set_all) {
 157                         br_port_set_promisc(p);
 158                 } else {
 159                         /* If the number of auto-ports is <= 1, then all other
 160                          * ports will have their output configuration
 161                          * statically specified through fdbs.  Since ingress
 162                          * on the auto-port becomes forwarding/egress to other
 163                          * ports and egress configuration is statically known,
 164                          * we can say that ingress configuration of the
 165                          * auto-port is also statically known.
 166                          * This lets us disable promiscuous mode and write
 167                          * this config to hw.
 168                          */
 169                         if (br->auto_cnt == 0 ||
 170                             (br->auto_cnt == 1 && br_auto_port(p)))
 171                                 br_port_clear_promisc(p);
 172                         else
 173                                 br_port_set_promisc(p);
 174                 }
 175         }
 176 }
 177
 178 int nbp_backup_change(struct net_bridge_port *p,
 179                       struct net_device *backup_dev)
 180 {
 181         struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
 182         struct net_bridge_port *backup_p = NULL;
 183
 184         ASSERT_RTNL();
 185
 186         if (backup_dev) {
 187                 if (!netif_is_bridge_port(backup_dev))
 188                         return -ENOENT;
 189
 190                 backup_p = br_port_get_rtnl(backup_dev);
 191                 if (backup_p->br != p->br)
 192                         return -EINVAL;
 193         }
 194
 195         if (p == backup_p)
 196                 return -EINVAL;
 197
 198         if (old_backup == backup_p)
 199                 return 0;
 200
 201         /* if the backup link is already set, clear it */
 202         if (old_backup)
 203                 old_backup->backup_redirected_cnt--;
 204
 205         if (backup_p)
 206                 backup_p->backup_redirected_cnt++;
 207         rcu_assign_pointer(p->backup_port, backup_p);
 208
 209         return 0;
 210 }
 211
 212 static void nbp_backup_clear(struct net_bridge_port *p)
 213 {
 214         nbp_backup_change(p, NULL);
 215         if (p->backup_redirected_cnt) {
 216                 struct net_bridge_port *cur_p;
 217
 218                 list_for_each_entry(cur_p, &p->br->port_list, list) {
 219                         struct net_bridge_port *backup_p;
 220
 221                         backup_p = rtnl_dereference(cur_p->backup_port);
 222                         if (backup_p == p)
 223                                 nbp_backup_change(cur_p, NULL);
 224                 }
 225         }
 226
 227         WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
 228 }
 229
 230 static void nbp_update_port_count(struct net_bridge *br)
 231 {
 232         struct net_bridge_port *p;
 233         u32 cnt = 0;
 234
 235         list_for_each_entry(p, &br->port_list, list) {
 236                 if (br_auto_port(p))
 237                         cnt++;
 238         }
 239         if (br->auto_cnt != cnt) {
 240                 br->auto_cnt = cnt;
 241                 br_manage_promisc(br);
 242         }
 243 }
 244
 245 static void nbp_delete_promisc(struct net_bridge_port *p)
 246 {
 247         /* If port is currently promiscuous, unset promiscuity.
 248          * Otherwise, it is a static port so remove all addresses
 249          * from it.
 250          */
 251         dev_set_allmulti(p->dev, -1);
 252         if (br_promisc_port(p))
 253                 dev_set_promiscuity(p->dev, -1);
 254         else
 255                 br_fdb_unsync_static(p->br, p);
 256 }
 257
 258 static void release_nbp(struct kobject *kobj)
 259 {
 260         struct net_bridge_port *p
 261                 = container_of(kobj, struct net_bridge_port, kobj);
 262         kfree(p);
 263 }
 264
 265 static void brport_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 266 {
 267         struct net_bridge_port *p = kobj_to_brport(kobj);
 268
 269         net_ns_get_ownership(dev_net(p->dev), uid, gid);
 270 }
 271
 272 static const struct kobj_type brport_ktype = {
 273 #ifdef CONFIG_SYSFS
 274         .sysfs_ops = &brport_sysfs_ops,
 275 #endif
 276         .release = release_nbp,
 277         .get_ownership = brport_get_ownership,
 278 };
 279
 280 static void destroy_nbp(struct net_bridge_port *p)
 281 {
 282         struct net_device *dev = p->dev;
 283
 284         p->br = NULL;
 285         p->dev = NULL;
 286         netdev_put(dev, &p->dev_tracker);
 287
 288         kobject_put(&p->kobj);
 289 }
 290
 291 static void destroy_nbp_rcu(struct rcu_head *head)
 292 {
 293         struct net_bridge_port *p =
 294                         container_of(head, struct net_bridge_port, rcu);
 295         destroy_nbp(p);
 296 }
 297
 298 static unsigned get_max_headroom(struct net_bridge *br)
 299 {
 300         unsigned max_headroom = 0;
 301         struct net_bridge_port *p;
 302
 303         list_for_each_entry(p, &br->port_list, list) {
 304                 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
 305
 306                 if (dev_headroom > max_headroom)
 307                         max_headroom = dev_headroom;
 308         }
 309
 310         return max_headroom;
 311 }
 312
 313 static void update_headroom(struct net_bridge *br, int new_hr)
 314 {
 315         struct net_bridge_port *p;
 316
 317         list_for_each_entry(p, &br->port_list, list)
 318                 netdev_set_rx_headroom(p->dev, new_hr);
 319
 320         br->dev->needed_headroom = new_hr;
 321 }
 322
 323 /* Delete port(interface) from bridge is done in two steps.
 324  * via RCU. First step, marks device as down. That deletes
 325  * all the timers and stops new packets from flowing through.
 326  *
 327  * Final cleanup doesn't occur until after all CPU's finished
 328  * processing packets.
 329  *
 330  * Protected from multiple admin operations by RTNL mutex
 331  */
 332 static void del_nbp(struct net_bridge_port *p)
 333 {
 334         struct net_bridge *br = p->br;
 335         struct net_device *dev = p->dev;
 336
 337         sysfs_remove_link(br->ifobj, p->dev->name);
 338
 339         nbp_delete_promisc(p);
 340
 341         spin_lock_bh(&br->lock);
 342         br_stp_disable_port(p);
 343         spin_unlock_bh(&br->lock);
 344
 345         br_mrp_port_del(br, p);
 346         br_cfm_port_del(br, p);
 347
 348         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 349
 350         list_del_rcu(&p->list);
 351         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 352                 update_headroom(br, get_max_headroom(br));
 353         netdev_reset_rx_headroom(dev);
 354
 355         nbp_vlan_flush(p);
 356         br_fdb_delete_by_port(br, p, 0, 1);
 357         switchdev_deferred_process();
 358         nbp_backup_clear(p);
 359
 360         nbp_update_port_count(br);
 361
 362         netdev_upper_dev_unlink(dev, br->dev);
 363
 364         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 365
 366         netdev_rx_handler_unregister(dev);
 367
 368         br_multicast_del_port(p);
 369
 370         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 371         kobject_del(&p->kobj);
 372
 373         br_netpoll_disable(p);
 374
 375         call_rcu(&p->rcu, destroy_nbp_rcu);
 376 }
 377
 378 /* Delete bridge device */
 379 void br_dev_delete(struct net_device *dev, struct list_head *head)
 380 {
 381         struct net_bridge *br = netdev_priv(dev);
 382         struct net_bridge_port *p, *n;
 383
 384         list_for_each_entry_safe(p, n, &br->port_list, list) {
 385                 del_nbp(p);
 386         }
 387
 388         br_recalculate_neigh_suppress_enabled(br);
 389
 390         br_fdb_delete_by_port(br, NULL, 0, 1);
 391
 392         cancel_delayed_work_sync(&br->gc_work);
 393
 394         br_sysfs_delbr(br->dev);
 395         unregister_netdevice_queue(br->dev, head);
 396 }
 397
 398 /* find an available port number */
 399 static int find_portno(struct net_bridge *br)
 400 {
 401         int index;
 402         struct net_bridge_port *p;
 403         unsigned long *inuse;
 404
 405         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 406         if (!inuse)
 407                 return -ENOMEM;
 408
 409         __set_bit(0, inuse);    /* zero is reserved */
 410         list_for_each_entry(p, &br->port_list, list)
 411                 __set_bit(p->port_no, inuse);
 412
 413         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 414         bitmap_free(inuse);
 415
 416         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 417 }
 418
 419 /* called with RTNL but without bridge lock */
 420 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 421                                        struct net_device *dev)
 422 {
 423         struct net_bridge_port *p;
 424         int index, err;
 425
 426         index = find_portno(br);
 427         if (index < 0)
 428                 return ERR_PTR(index);
 429
 430         p = kzalloc(sizeof(*p), GFP_KERNEL);
 431         if (p == NULL)
 432                 return ERR_PTR(-ENOMEM);
 433
 434         p->br = br;
 435         netdev_hold(dev, &p->dev_tracker, GFP_KERNEL);
 436         p->dev = dev;
 437         p->path_cost = port_cost(dev);
 438         p->priority = 0x8000 >> BR_PORT_BITS;
 439         p->port_no = index;
 440         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 441         br_init_port(p);
 442         br_set_state(p, BR_STATE_DISABLED);
 443         br_stp_port_timer_init(p);
 444         err = br_multicast_add_port(p);
 445         if (err) {
 446                 netdev_put(dev, &p->dev_tracker);
 447                 kfree(p);
 448                 p = ERR_PTR(err);
 449         }
 450
 451         return p;
 452 }
 453
 454 int br_add_bridge(struct net *net, const char *name)
 455 {
 456         struct net_device *dev;
 457         int res;
 458
 459         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 460                            br_dev_setup);
 461
 462         if (!dev)
 463                 return -ENOMEM;
 464
 465         dev_net_set(dev, net);
 466         dev->rtnl_link_ops = &br_link_ops;
 467
 468         res = register_netdevice(dev);
 469         if (res)
 470                 free_netdev(dev);
 471         return res;
 472 }
 473
 474 int br_del_bridge(struct net *net, const char *name)
 475 {
 476         struct net_device *dev;
 477         int ret = 0;
 478
 479         dev = __dev_get_by_name(net, name);
 480         if (dev == NULL)
 481                 ret =  -ENXIO;  /* Could not find device */
 482
 483         else if (!netif_is_bridge_master(dev)) {
 484                 /* Attempt to delete non bridge device! */
 485                 ret = -EPERM;
 486         }
 487
 488         else if (dev->flags & IFF_UP) {
 489                 /* Not shutdown yet. */
 490                 ret = -EBUSY;
 491         }
 492
 493         else
 494                 br_dev_delete(dev, NULL);
 495
 496         return ret;
 497 }
 498
 499 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 500 static int br_mtu_min(const struct net_bridge *br)
 501 {
 502         const struct net_bridge_port *p;
 503         int ret_mtu = 0;
 504
 505         list_for_each_entry(p, &br->port_list, list)
 506                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 507                         ret_mtu = p->dev->mtu;
 508
 509         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 510 }
 511
 512 void br_mtu_auto_adjust(struct net_bridge *br)
 513 {
 514         ASSERT_RTNL();
 515
 516         /* if the bridge MTU was manually configured don't mess with it */
 517         if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 518                 return;
 519
 520         /* change to the minimum MTU and clear the flag which was set by
 521          * the bridge ndo_change_mtu callback
 522          */
 523         dev_set_mtu(br->dev, br_mtu_min(br));
 524         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 525 }
 526
 527 static void br_set_gso_limits(struct net_bridge *br)
 528 {
 529         unsigned int tso_max_size = TSO_MAX_SIZE;
 530         const struct net_bridge_port *p;
 531         u16 tso_max_segs = TSO_MAX_SEGS;
 532
 533         list_for_each_entry(p, &br->port_list, list) {
 534                 tso_max_size = min(tso_max_size, p->dev->tso_max_size);
 535                 tso_max_segs = min(tso_max_segs, p->dev->tso_max_segs);
 536         }
 537         netif_set_tso_max_size(br->dev, tso_max_size);
 538         netif_set_tso_max_segs(br->dev, tso_max_segs);
 539 }
 540
 541 /*
 542  * Recomputes features using slave's features
 543  */
 544 netdev_features_t br_features_recompute(struct net_bridge *br,
 545         netdev_features_t features)
 546 {
 547         struct net_bridge_port *p;
 548         netdev_features_t mask;
 549
 550         if (list_empty(&br->port_list))
 551                 return features;
 552
 553         mask = features;
 554         features &= ~NETIF_F_ONE_FOR_ALL;
 555
 556         list_for_each_entry(p, &br->port_list, list) {
 557                 features = netdev_increment_features(features,
 558                                                      p->dev->features, mask);
 559         }
 560         features = netdev_add_tso_features(features, mask);
 561
 562         return features;
 563 }
 564
 565 /* called with RTNL */
 566 int br_add_if(struct net_bridge *br, struct net_device *dev,
 567               struct netlink_ext_ack *extack)
 568 {
 569         struct net_bridge_port *p;
 570         int err = 0;
 571         unsigned br_hr, dev_hr;
 572         bool changed_addr, fdb_synced = false;
 573
 574         /* Don't allow bridging non-ethernet like devices. */
 575         if ((dev->flags & IFF_LOOPBACK) ||
 576             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 577             !is_valid_ether_addr(dev->dev_addr))
 578                 return -EINVAL;
 579
 580         /* No bridging of bridges */
 581         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
 582                 NL_SET_ERR_MSG(extack,
 583                                "Can not enslave a bridge to a bridge");
 584                 return -ELOOP;
 585         }
 586
 587         /* Device has master upper dev */
 588         if (netdev_master_upper_dev_get(dev))
 589                 return -EBUSY;
 590
 591         /* No bridging devices that dislike that (e.g. wireless) */
 592         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 593                 NL_SET_ERR_MSG(extack,
 594                                "Device does not allow enslaving to a bridge");
 595                 return -EOPNOTSUPP;
 596         }
 597
 598         p = new_nbp(br, dev);
 599         if (IS_ERR(p))
 600                 return PTR_ERR(p);
 601
 602         call_netdevice_notifiers(NETDEV_JOIN, dev);
 603
 604         err = dev_set_allmulti(dev, 1);
 605         if (err) {
 606                 br_multicast_del_port(p);
 607                 netdev_put(dev, &p->dev_tracker);
 608                 kfree(p);       /* kobject not yet init'd, manually free */
 609                 goto err1;
 610         }
 611
 612         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 613                                    SYSFS_BRIDGE_PORT_ATTR);
 614         if (err)
 615                 goto err2;
 616
 617         err = br_sysfs_addif(p);
 618         if (err)
 619                 goto err2;
 620
 621         err = br_netpoll_enable(p);
 622         if (err)
 623                 goto err3;
 624
 625         err = netdev_rx_handler_register(dev, br_get_rx_handler(dev), p);
 626         if (err)
 627                 goto err4;
 628
 629         dev->priv_flags |= IFF_BRIDGE_PORT;
 630
 631         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 632         if (err)
 633                 goto err5;
 634
 635         dev_disable_lro(dev);
 636
 637         list_add_rcu(&p->list, &br->port_list);
 638
 639         nbp_update_port_count(br);
 640         if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) {
 641                 /* When updating the port count we also update all ports'
 642                  * promiscuous mode.
 643                  * A port leaving promiscuous mode normally gets the bridge's
 644                  * fdb synced to the unicast filter (if supported), however,
 645                  * `br_port_clear_promisc` does not distinguish between
 646                  * non-promiscuous ports and *new* ports, so we need to
 647                  * sync explicitly here.
 648                  */
 649                 fdb_synced = br_fdb_sync_static(br, p) == 0;
 650                 if (!fdb_synced)
 651                         netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n");
 652         }
 653
 654         netdev_update_features(br->dev);
 655
 656         br_hr = br->dev->needed_headroom;
 657         dev_hr = netdev_get_fwd_headroom(dev);
 658         if (br_hr < dev_hr)
 659                 update_headroom(br, dev_hr);
 660         else
 661                 netdev_set_rx_headroom(dev, br_hr);
 662
 663         if (br_fdb_add_local(br, p, dev->dev_addr, 0))
 664                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 665
 666         if (br->dev->addr_assign_type != NET_ADDR_SET) {
 667                 /* Ask for permission to use this MAC address now, even if we
 668                  * don't end up choosing it below.
 669                  */
 670                 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
 671                 if (err)
 672                         goto err6;
 673         }
 674
 675         err = nbp_vlan_init(p, extack);
 676         if (err) {
 677                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 678                 goto err6;
 679         }
 680
 681         spin_lock_bh(&br->lock);
 682         changed_addr = br_stp_recalculate_bridge_id(br);
 683
 684         if (netif_running(dev) && netif_oper_up(dev) &&
 685             (br->dev->flags & IFF_UP))
 686                 br_stp_enable_port(p);
 687         spin_unlock_bh(&br->lock);
 688
 689         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 690
 691         if (changed_addr)
 692                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 693
 694         br_mtu_auto_adjust(br);
 695         br_set_gso_limits(br);
 696
 697         kobject_uevent(&p->kobj, KOBJ_ADD);
 698
 699         return 0;
 700
 701 err6:
 702         if (fdb_synced)
 703                 br_fdb_unsync_static(br, p);
 704         list_del_rcu(&p->list);
 705         br_fdb_delete_by_port(br, p, 0, 1);
 706         nbp_update_port_count(br);
 707         netdev_upper_dev_unlink(dev, br->dev);
 708 err5:
 709         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 710         netdev_rx_handler_unregister(dev);
 711 err4:
 712         br_netpoll_disable(p);
 713 err3:
 714         sysfs_remove_link(br->ifobj, p->dev->name);
 715 err2:
 716         br_multicast_del_port(p);
 717         netdev_put(dev, &p->dev_tracker);
 718         kobject_put(&p->kobj);
 719         dev_set_allmulti(dev, -1);
 720 err1:
 721         return err;
 722 }
 723
 724 /* called with RTNL */
 725 int br_del_if(struct net_bridge *br, struct net_device *dev)
 726 {
 727         struct net_bridge_port *p;
 728         bool changed_addr;
 729
 730         p = br_port_get_rtnl(dev);
 731         if (!p || p->br != br)
 732                 return -EINVAL;
 733
 734         /* Since more than one interface can be attached to a bridge,
 735          * there still maybe an alternate path for netconsole to use;
 736          * therefore there is no reason for a NETDEV_RELEASE event.
 737          */
 738         del_nbp(p);
 739
 740         br_mtu_auto_adjust(br);
 741         br_set_gso_limits(br);
 742
 743         spin_lock_bh(&br->lock);
 744         changed_addr = br_stp_recalculate_bridge_id(br);
 745         spin_unlock_bh(&br->lock);
 746
 747         if (changed_addr)
 748                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 749
 750         netdev_update_features(br->dev);
 751
 752         return 0;
 753 }
 754
 755 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 756 {
 757         struct net_bridge *br = p->br;
 758
 759         if (mask & BR_AUTO_MASK)
 760                 nbp_update_port_count(br);
 761
 762         if (mask & (BR_NEIGH_SUPPRESS | BR_NEIGH_VLAN_SUPPRESS))
 763                 br_recalculate_neigh_suppress_enabled(br);
 764 }
 765
 766 bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
 767 {
 768         struct net_bridge_port *p;
 769
 770         p = br_port_get_rtnl_rcu(dev);
 771         if (!p)
 772                 return false;
 773
 774         return p->flags & flag;
 775 }
 776 EXPORT_SYMBOL_GPL(br_port_flag_is_set);