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_1000:
  44                         return 4;
  45                 case SPEED_100:
  46                         return 19;
  47                 case SPEED_10:
  48                         return 100;
  49                 }
  50         }
  51
  52         /* Old silly heuristics based on name */
  53         if (!strncmp(dev->name, "lec", 3))
  54                 return 7;
  55
  56         if (!strncmp(dev->name, "plip", 4))
  57                 return 2500;
  58
  59         return 100;     /* assume old 10Mbps */
  60 }
  61
  62
  63 /* Check for port carrier transitions. */
  64 void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
  65 {
  66         struct net_device *dev = p->dev;
  67         struct net_bridge *br = p->br;
  68
  69         if (!(p->flags & BR_ADMIN_COST) &&
  70             netif_running(dev) && netif_oper_up(dev))
  71                 p->path_cost = port_cost(dev);
  72
  73         *notified = false;
  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                         *notified = true;
  82                 }
  83         } else {
  84                 if (p->state != BR_STATE_DISABLED) {
  85                         br_stp_disable_port(p);
  86                         *notified = true;
  87                 }
  88         }
  89         spin_unlock_bh(&br->lock);
  90 }
  91
  92 static void br_port_set_promisc(struct net_bridge_port *p)
  93 {
  94         int err = 0;
  95
  96         if (br_promisc_port(p))
  97                 return;
  98
  99         err = dev_set_promiscuity(p->dev, 1);
 100         if (err)
 101                 return;
 102
 103         br_fdb_unsync_static(p->br, p);
 104         p->flags |= BR_PROMISC;
 105 }
 106
 107 static void br_port_clear_promisc(struct net_bridge_port *p)
 108 {
 109         int err;
 110
 111         /* Check if the port is already non-promisc or if it doesn't
 112          * support UNICAST filtering.  Without unicast filtering support
 113          * we'll end up re-enabling promisc mode anyway, so just check for
 114          * it here.
 115          */
 116         if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
 117                 return;
 118
 119         /* Since we'll be clearing the promisc mode, program the port
 120          * first so that we don't have interruption in traffic.
 121          */
 122         err = br_fdb_sync_static(p->br, p);
 123         if (err)
 124                 return;
 125
 126         dev_set_promiscuity(p->dev, -1);
 127         p->flags &= ~BR_PROMISC;
 128 }
 129
 130 /* When a port is added or removed or when certain port flags
 131  * change, this function is called to automatically manage
 132  * promiscuity setting of all the bridge ports.  We are always called
 133  * under RTNL so can skip using rcu primitives.
 134  */
 135 void br_manage_promisc(struct net_bridge *br)
 136 {
 137         struct net_bridge_port *p;
 138         bool set_all = false;
 139
 140         /* If vlan filtering is disabled or bridge interface is placed
 141          * into promiscuous mode, place all ports in promiscuous mode.
 142          */
 143         if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
 144                 set_all = true;
 145
 146         list_for_each_entry(p, &br->port_list, list) {
 147                 if (set_all) {
 148                         br_port_set_promisc(p);
 149                 } else {
 150                         /* If the number of auto-ports is <= 1, then all other
 151                          * ports will have their output configuration
 152                          * statically specified through fdbs.  Since ingress
 153                          * on the auto-port becomes forwarding/egress to other
 154                          * ports and egress configuration is statically known,
 155                          * we can say that ingress configuration of the
 156                          * auto-port is also statically known.
 157                          * This lets us disable promiscuous mode and write
 158                          * this config to hw.
 159                          */
 160                         if (br->auto_cnt == 0 ||
 161                             (br->auto_cnt == 1 && br_auto_port(p)))
 162                                 br_port_clear_promisc(p);
 163                         else
 164                                 br_port_set_promisc(p);
 165                 }
 166         }
 167 }
 168
 169 int nbp_backup_change(struct net_bridge_port *p,
 170                       struct net_device *backup_dev)
 171 {
 172         struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
 173         struct net_bridge_port *backup_p = NULL;
 174
 175         ASSERT_RTNL();
 176
 177         if (backup_dev) {
 178                 if (!netif_is_bridge_port(backup_dev))
 179                         return -ENOENT;
 180
 181                 backup_p = br_port_get_rtnl(backup_dev);
 182                 if (backup_p->br != p->br)
 183                         return -EINVAL;
 184         }
 185
 186         if (p == backup_p)
 187                 return -EINVAL;
 188
 189         if (old_backup == backup_p)
 190                 return 0;
 191
 192         /* if the backup link is already set, clear it */
 193         if (old_backup)
 194                 old_backup->backup_redirected_cnt--;
 195
 196         if (backup_p)
 197                 backup_p->backup_redirected_cnt++;
 198         rcu_assign_pointer(p->backup_port, backup_p);
 199
 200         return 0;
 201 }
 202
 203 static void nbp_backup_clear(struct net_bridge_port *p)
 204 {
 205         nbp_backup_change(p, NULL);
 206         if (p->backup_redirected_cnt) {
 207                 struct net_bridge_port *cur_p;
 208
 209                 list_for_each_entry(cur_p, &p->br->port_list, list) {
 210                         struct net_bridge_port *backup_p;
 211
 212                         backup_p = rtnl_dereference(cur_p->backup_port);
 213                         if (backup_p == p)
 214                                 nbp_backup_change(cur_p, NULL);
 215                 }
 216         }
 217
 218         WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
 219 }
 220
 221 static void nbp_update_port_count(struct net_bridge *br)
 222 {
 223         struct net_bridge_port *p;
 224         u32 cnt = 0;
 225
 226         list_for_each_entry(p, &br->port_list, list) {
 227                 if (br_auto_port(p))
 228                         cnt++;
 229         }
 230         if (br->auto_cnt != cnt) {
 231                 br->auto_cnt = cnt;
 232                 br_manage_promisc(br);
 233         }
 234 }
 235
 236 static void nbp_delete_promisc(struct net_bridge_port *p)
 237 {
 238         /* If port is currently promiscuous, unset promiscuity.
 239          * Otherwise, it is a static port so remove all addresses
 240          * from it.
 241          */
 242         dev_set_allmulti(p->dev, -1);
 243         if (br_promisc_port(p))
 244                 dev_set_promiscuity(p->dev, -1);
 245         else
 246                 br_fdb_unsync_static(p->br, p);
 247 }
 248
 249 static void release_nbp(struct kobject *kobj)
 250 {
 251         struct net_bridge_port *p
 252                 = container_of(kobj, struct net_bridge_port, kobj);
 253         kfree(p);
 254 }
 255
 256 static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 257 {
 258         struct net_bridge_port *p = kobj_to_brport(kobj);
 259
 260         net_ns_get_ownership(dev_net(p->dev), uid, gid);
 261 }
 262
 263 static struct kobj_type brport_ktype = {
 264 #ifdef CONFIG_SYSFS
 265         .sysfs_ops = &brport_sysfs_ops,
 266 #endif
 267         .release = release_nbp,
 268         .get_ownership = brport_get_ownership,
 269 };
 270
 271 static void destroy_nbp(struct net_bridge_port *p)
 272 {
 273         struct net_device *dev = p->dev;
 274
 275         p->br = NULL;
 276         p->dev = NULL;
 277         dev_put(dev);
 278
 279         kobject_put(&p->kobj);
 280 }
 281
 282 static void destroy_nbp_rcu(struct rcu_head *head)
 283 {
 284         struct net_bridge_port *p =
 285                         container_of(head, struct net_bridge_port, rcu);
 286         destroy_nbp(p);
 287 }
 288
 289 static unsigned get_max_headroom(struct net_bridge *br)
 290 {
 291         unsigned max_headroom = 0;
 292         struct net_bridge_port *p;
 293
 294         list_for_each_entry(p, &br->port_list, list) {
 295                 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
 296
 297                 if (dev_headroom > max_headroom)
 298                         max_headroom = dev_headroom;
 299         }
 300
 301         return max_headroom;
 302 }
 303
 304 static void update_headroom(struct net_bridge *br, int new_hr)
 305 {
 306         struct net_bridge_port *p;
 307
 308         list_for_each_entry(p, &br->port_list, list)
 309                 netdev_set_rx_headroom(p->dev, new_hr);
 310
 311         br->dev->needed_headroom = new_hr;
 312 }
 313
 314 /* Delete port(interface) from bridge is done in two steps.
 315  * via RCU. First step, marks device as down. That deletes
 316  * all the timers and stops new packets from flowing through.
 317  *
 318  * Final cleanup doesn't occur until after all CPU's finished
 319  * processing packets.
 320  *
 321  * Protected from multiple admin operations by RTNL mutex
 322  */
 323 static void del_nbp(struct net_bridge_port *p)
 324 {
 325         struct net_bridge *br = p->br;
 326         struct net_device *dev = p->dev;
 327
 328         sysfs_remove_link(br->ifobj, p->dev->name);
 329
 330         nbp_delete_promisc(p);
 331
 332         spin_lock_bh(&br->lock);
 333         br_stp_disable_port(p);
 334         spin_unlock_bh(&br->lock);
 335
 336         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 337
 338         list_del_rcu(&p->list);
 339         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 340                 update_headroom(br, get_max_headroom(br));
 341         netdev_reset_rx_headroom(dev);
 342
 343         nbp_vlan_flush(p);
 344         br_fdb_delete_by_port(br, p, 0, 1);
 345         switchdev_deferred_process();
 346         nbp_backup_clear(p);
 347
 348         nbp_update_port_count(br);
 349
 350         netdev_upper_dev_unlink(dev, br->dev);
 351
 352         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 353
 354         netdev_rx_handler_unregister(dev);
 355
 356         br_multicast_del_port(p);
 357
 358         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 359         kobject_del(&p->kobj);
 360
 361         br_netpoll_disable(p);
 362
 363         call_rcu(&p->rcu, destroy_nbp_rcu);
 364 }
 365
 366 /* Delete bridge device */
 367 void br_dev_delete(struct net_device *dev, struct list_head *head)
 368 {
 369         struct net_bridge *br = netdev_priv(dev);
 370         struct net_bridge_port *p, *n;
 371
 372         list_for_each_entry_safe(p, n, &br->port_list, list) {
 373                 del_nbp(p);
 374         }
 375
 376         br_recalculate_neigh_suppress_enabled(br);
 377
 378         br_fdb_delete_by_port(br, NULL, 0, 1);
 379
 380         cancel_delayed_work_sync(&br->gc_work);
 381
 382         br_sysfs_delbr(br->dev);
 383         unregister_netdevice_queue(br->dev, head);
 384 }
 385
 386 /* find an available port number */
 387 static int find_portno(struct net_bridge *br)
 388 {
 389         int index;
 390         struct net_bridge_port *p;
 391         unsigned long *inuse;
 392
 393         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 394         if (!inuse)
 395                 return -ENOMEM;
 396
 397         set_bit(0, inuse);      /* zero is reserved */
 398         list_for_each_entry(p, &br->port_list, list) {
 399                 set_bit(p->port_no, inuse);
 400         }
 401         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 402         bitmap_free(inuse);
 403
 404         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 405 }
 406
 407 /* called with RTNL but without bridge lock */
 408 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 409                                        struct net_device *dev)
 410 {
 411         struct net_bridge_port *p;
 412         int index, err;
 413
 414         index = find_portno(br);
 415         if (index < 0)
 416                 return ERR_PTR(index);
 417
 418         p = kzalloc(sizeof(*p), GFP_KERNEL);
 419         if (p == NULL)
 420                 return ERR_PTR(-ENOMEM);
 421
 422         p->br = br;
 423         dev_hold(dev);
 424         p->dev = dev;
 425         p->path_cost = port_cost(dev);
 426         p->priority = 0x8000 >> BR_PORT_BITS;
 427         p->port_no = index;
 428         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 429         br_init_port(p);
 430         br_set_state(p, BR_STATE_DISABLED);
 431         br_stp_port_timer_init(p);
 432         err = br_multicast_add_port(p);
 433         if (err) {
 434                 dev_put(dev);
 435                 kfree(p);
 436                 p = ERR_PTR(err);
 437         }
 438
 439         return p;
 440 }
 441
 442 int br_add_bridge(struct net *net, const char *name)
 443 {
 444         struct net_device *dev;
 445         int res;
 446
 447         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 448                            br_dev_setup);
 449
 450         if (!dev)
 451                 return -ENOMEM;
 452
 453         dev_net_set(dev, net);
 454         dev->rtnl_link_ops = &br_link_ops;
 455
 456         res = register_netdev(dev);
 457         if (res)
 458                 free_netdev(dev);
 459         return res;
 460 }
 461
 462 int br_del_bridge(struct net *net, const char *name)
 463 {
 464         struct net_device *dev;
 465         int ret = 0;
 466
 467         rtnl_lock();
 468         dev = __dev_get_by_name(net, name);
 469         if (dev == NULL)
 470                 ret =  -ENXIO;  /* Could not find device */
 471
 472         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 473                 /* Attempt to delete non bridge device! */
 474                 ret = -EPERM;
 475         }
 476
 477         else if (dev->flags & IFF_UP) {
 478                 /* Not shutdown yet. */
 479                 ret = -EBUSY;
 480         }
 481
 482         else
 483                 br_dev_delete(dev, NULL);
 484
 485         rtnl_unlock();
 486         return ret;
 487 }
 488
 489 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 490 static int br_mtu_min(const struct net_bridge *br)
 491 {
 492         const struct net_bridge_port *p;
 493         int ret_mtu = 0;
 494
 495         list_for_each_entry(p, &br->port_list, list)
 496                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 497                         ret_mtu = p->dev->mtu;
 498
 499         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 500 }
 501
 502 void br_mtu_auto_adjust(struct net_bridge *br)
 503 {
 504         ASSERT_RTNL();
 505
 506         /* if the bridge MTU was manually configured don't mess with it */
 507         if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 508                 return;
 509
 510         /* change to the minimum MTU and clear the flag which was set by
 511          * the bridge ndo_change_mtu callback
 512          */
 513         dev_set_mtu(br->dev, br_mtu_min(br));
 514         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 515 }
 516
 517 static void br_set_gso_limits(struct net_bridge *br)
 518 {
 519         unsigned int gso_max_size = GSO_MAX_SIZE;
 520         u16 gso_max_segs = GSO_MAX_SEGS;
 521         const struct net_bridge_port *p;
 522
 523         list_for_each_entry(p, &br->port_list, list) {
 524                 gso_max_size = min(gso_max_size, p->dev->gso_max_size);
 525                 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
 526         }
 527         br->dev->gso_max_size = gso_max_size;
 528         br->dev->gso_max_segs = gso_max_segs;
 529 }
 530
 531 /*
 532  * Recomputes features using slave's features
 533  */
 534 netdev_features_t br_features_recompute(struct net_bridge *br,
 535         netdev_features_t features)
 536 {
 537         struct net_bridge_port *p;
 538         netdev_features_t mask;
 539
 540         if (list_empty(&br->port_list))
 541                 return features;
 542
 543         mask = features;
 544         features &= ~NETIF_F_ONE_FOR_ALL;
 545
 546         list_for_each_entry(p, &br->port_list, list) {
 547                 features = netdev_increment_features(features,
 548                                                      p->dev->features, mask);
 549         }
 550         features = netdev_add_tso_features(features, mask);
 551
 552         return features;
 553 }
 554
 555 /* called with RTNL */
 556 int br_add_if(struct net_bridge *br, struct net_device *dev,
 557               struct netlink_ext_ack *extack)
 558 {
 559         struct net_bridge_port *p;
 560         int err = 0;
 561         unsigned br_hr, dev_hr;
 562         bool changed_addr;
 563
 564         /* Don't allow bridging non-ethernet like devices, or DSA-enabled
 565          * master network devices since the bridge layer rx_handler prevents
 566          * the DSA fake ethertype handler to be invoked, so we do not strip off
 567          * the DSA switch tag protocol header and the bridge layer just return
 568          * RX_HANDLER_CONSUMED, stopping RX processing for these frames.
 569          */
 570         if ((dev->flags & IFF_LOOPBACK) ||
 571             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 572             !is_valid_ether_addr(dev->dev_addr) ||
 573             netdev_uses_dsa(dev))
 574                 return -EINVAL;
 575
 576         /* No bridging of bridges */
 577         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
 578                 NL_SET_ERR_MSG(extack,
 579                                "Can not enslave a bridge to a bridge");
 580                 return -ELOOP;
 581         }
 582
 583         /* Device has master upper dev */
 584         if (netdev_master_upper_dev_get(dev))
 585                 return -EBUSY;
 586
 587         /* No bridging devices that dislike that (e.g. wireless) */
 588         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 589                 NL_SET_ERR_MSG(extack,
 590                                "Device does not allow enslaving to a bridge");
 591                 return -EOPNOTSUPP;
 592         }
 593
 594         p = new_nbp(br, dev);
 595         if (IS_ERR(p))
 596                 return PTR_ERR(p);
 597
 598         call_netdevice_notifiers(NETDEV_JOIN, dev);
 599
 600         err = dev_set_allmulti(dev, 1);
 601         if (err) {
 602                 kfree(p);       /* kobject not yet init'd, manually free */
 603                 goto err1;
 604         }
 605
 606         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 607                                    SYSFS_BRIDGE_PORT_ATTR);
 608         if (err)
 609                 goto err2;
 610
 611         err = br_sysfs_addif(p);
 612         if (err)
 613                 goto err2;
 614
 615         err = br_netpoll_enable(p);
 616         if (err)
 617                 goto err3;
 618
 619         err = netdev_rx_handler_register(dev, br_handle_frame, p);
 620         if (err)
 621                 goto err4;
 622
 623         dev->priv_flags |= IFF_BRIDGE_PORT;
 624
 625         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 626         if (err)
 627                 goto err5;
 628
 629         err = nbp_switchdev_mark_set(p);
 630         if (err)
 631                 goto err6;
 632
 633         dev_disable_lro(dev);
 634
 635         list_add_rcu(&p->list, &br->port_list);
 636
 637         nbp_update_port_count(br);
 638
 639         netdev_update_features(br->dev);
 640
 641         br_hr = br->dev->needed_headroom;
 642         dev_hr = netdev_get_fwd_headroom(dev);
 643         if (br_hr < dev_hr)
 644                 update_headroom(br, dev_hr);
 645         else
 646                 netdev_set_rx_headroom(dev, br_hr);
 647
 648         if (br_fdb_insert(br, p, dev->dev_addr, 0))
 649                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 650
 651         if (br->dev->addr_assign_type != NET_ADDR_SET) {
 652                 /* Ask for permission to use this MAC address now, even if we
 653                  * don't end up choosing it below.
 654                  */
 655                 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
 656                 if (err)
 657                         goto err7;
 658         }
 659
 660         err = nbp_vlan_init(p, extack);
 661         if (err) {
 662                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 663                 goto err7;
 664         }
 665
 666         spin_lock_bh(&br->lock);
 667         changed_addr = br_stp_recalculate_bridge_id(br);
 668
 669         if (netif_running(dev) && netif_oper_up(dev) &&
 670             (br->dev->flags & IFF_UP))
 671                 br_stp_enable_port(p);
 672         spin_unlock_bh(&br->lock);
 673
 674         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 675
 676         if (changed_addr)
 677                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 678
 679         br_mtu_auto_adjust(br);
 680         br_set_gso_limits(br);
 681
 682         kobject_uevent(&p->kobj, KOBJ_ADD);
 683
 684         return 0;
 685
 686 err7:
 687         list_del_rcu(&p->list);
 688         br_fdb_delete_by_port(br, p, 0, 1);
 689         nbp_update_port_count(br);
 690 err6:
 691         netdev_upper_dev_unlink(dev, br->dev);
 692 err5:
 693         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 694         netdev_rx_handler_unregister(dev);
 695 err4:
 696         br_netpoll_disable(p);
 697 err3:
 698         sysfs_remove_link(br->ifobj, p->dev->name);
 699 err2:
 700         kobject_put(&p->kobj);
 701         dev_set_allmulti(dev, -1);
 702 err1:
 703         dev_put(dev);
 704         return err;
 705 }
 706
 707 /* called with RTNL */
 708 int br_del_if(struct net_bridge *br, struct net_device *dev)
 709 {
 710         struct net_bridge_port *p;
 711         bool changed_addr;
 712
 713         p = br_port_get_rtnl(dev);
 714         if (!p || p->br != br)
 715                 return -EINVAL;
 716
 717         /* Since more than one interface can be attached to a bridge,
 718          * there still maybe an alternate path for netconsole to use;
 719          * therefore there is no reason for a NETDEV_RELEASE event.
 720          */
 721         del_nbp(p);
 722
 723         br_mtu_auto_adjust(br);
 724         br_set_gso_limits(br);
 725
 726         spin_lock_bh(&br->lock);
 727         changed_addr = br_stp_recalculate_bridge_id(br);
 728         spin_unlock_bh(&br->lock);
 729
 730         if (changed_addr)
 731                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 732
 733         netdev_update_features(br->dev);
 734
 735         return 0;
 736 }
 737
 738 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 739 {
 740         struct net_bridge *br = p->br;
 741
 742         if (mask & BR_AUTO_MASK)
 743                 nbp_update_port_count(br);
 744
 745         if (mask & BR_NEIGH_SUPPRESS)
 746                 br_recalculate_neigh_suppress_enabled(br);
 747 }
 748
 749 bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
 750 {
 751         struct net_bridge_port *p;
 752
 753         p = br_port_get_rtnl_rcu(dev);
 754         if (!p)
 755                 return false;
 756
 757         return p->flags & flag;
 758 }
 759 EXPORT_SYMBOL_GPL(br_port_flag_is_set);