net/bridge/br_if.c

   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 #include <net/net_namespace.h>
  30
  31 #include "br_private.h"
  32
  33 /*
  34  * Determine initial path cost based on speed.
  35  * using recommendations from 802.1d standard
  36  *
  37  * Since driver might sleep need to not be holding any locks.
  38  */
  39 static int port_cost(struct net_device *dev)
  40 {
  41         struct ethtool_link_ksettings ecmd;
  42
  43         if (!__ethtool_get_link_ksettings(dev, &ecmd)) {
  44                 switch (ecmd.base.speed) {
  45                 case SPEED_10000:
  46                         return 2;
  47                 case SPEED_1000:
  48                         return 4;
  49                 case SPEED_100:
  50                         return 19;
  51                 case SPEED_10:
  52                         return 100;
  53                 }
  54         }
  55
  56         /* Old silly heuristics based on name */
  57         if (!strncmp(dev->name, "lec", 3))
  58                 return 7;
  59
  60         if (!strncmp(dev->name, "plip", 4))
  61                 return 2500;
  62
  63         return 100;     /* assume old 10Mbps */
  64 }
  65
  66
  67 /* Check for port carrier transitions. */
  68 void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
  69 {
  70         struct net_device *dev = p->dev;
  71         struct net_bridge *br = p->br;
  72
  73         if (!(p->flags & BR_ADMIN_COST) &&
  74             netif_running(dev) && netif_oper_up(dev))
  75                 p->path_cost = port_cost(dev);
  76
  77         *notified = false;
  78         if (!netif_running(br->dev))
  79                 return;
  80
  81         spin_lock_bh(&br->lock);
  82         if (netif_running(dev) && netif_oper_up(dev)) {
  83                 if (p->state == BR_STATE_DISABLED) {
  84                         br_stp_enable_port(p);
  85                         *notified = true;
  86                 }
  87         } else {
  88                 if (p->state != BR_STATE_DISABLED) {
  89                         br_stp_disable_port(p);
  90                         *notified = true;
  91                 }
  92         }
  93         spin_unlock_bh(&br->lock);
  94 }
  95
  96 static void br_port_set_promisc(struct net_bridge_port *p)
  97 {
  98         int err = 0;
  99
 100         if (br_promisc_port(p))
 101                 return;
 102
 103         err = dev_set_promiscuity(p->dev, 1);
 104         if (err)
 105                 return;
 106
 107         br_fdb_unsync_static(p->br, p);
 108         p->flags |= BR_PROMISC;
 109 }
 110
 111 static void br_port_clear_promisc(struct net_bridge_port *p)
 112 {
 113         int err;
 114
 115         /* Check if the port is already non-promisc or if it doesn't
 116          * support UNICAST filtering.  Without unicast filtering support
 117          * we'll end up re-enabling promisc mode anyway, so just check for
 118          * it here.
 119          */
 120         if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
 121                 return;
 122
 123         /* Since we'll be clearing the promisc mode, program the port
 124          * first so that we don't have interruption in traffic.
 125          */
 126         err = br_fdb_sync_static(p->br, p);
 127         if (err)
 128                 return;
 129
 130         dev_set_promiscuity(p->dev, -1);
 131         p->flags &= ~BR_PROMISC;
 132 }
 133
 134 /* When a port is added or removed or when certain port flags
 135  * change, this function is called to automatically manage
 136  * promiscuity setting of all the bridge ports.  We are always called
 137  * under RTNL so can skip using rcu primitives.
 138  */
 139 void br_manage_promisc(struct net_bridge *br)
 140 {
 141         struct net_bridge_port *p;
 142         bool set_all = false;
 143
 144         /* If vlan filtering is disabled or bridge interface is placed
 145          * into promiscuous mode, place all ports in promiscuous mode.
 146          */
 147         if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
 148                 set_all = true;
 149
 150         list_for_each_entry(p, &br->port_list, list) {
 151                 if (set_all) {
 152                         br_port_set_promisc(p);
 153                 } else {
 154                         /* If the number of auto-ports is <= 1, then all other
 155                          * ports will have their output configuration
 156                          * statically specified through fdbs.  Since ingress
 157                          * on the auto-port becomes forwarding/egress to other
 158                          * ports and egress configuration is statically known,
 159                          * we can say that ingress configuration of the
 160                          * auto-port is also statically known.
 161                          * This lets us disable promiscuous mode and write
 162                          * this config to hw.
 163                          */
 164                         if (br->auto_cnt == 0 ||
 165                             (br->auto_cnt == 1 && br_auto_port(p)))
 166                                 br_port_clear_promisc(p);
 167                         else
 168                                 br_port_set_promisc(p);
 169                 }
 170         }
 171 }
 172
 173 int nbp_backup_change(struct net_bridge_port *p,
 174                       struct net_device *backup_dev)
 175 {
 176         struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
 177         struct net_bridge_port *backup_p = NULL;
 178
 179         ASSERT_RTNL();
 180
 181         if (backup_dev) {
 182                 if (!netif_is_bridge_port(backup_dev))
 183                         return -ENOENT;
 184
 185                 backup_p = br_port_get_rtnl(backup_dev);
 186                 if (backup_p->br != p->br)
 187                         return -EINVAL;
 188         }
 189
 190         if (p == backup_p)
 191                 return -EINVAL;
 192
 193         if (old_backup == backup_p)
 194                 return 0;
 195
 196         /* if the backup link is already set, clear it */
 197         if (old_backup)
 198                 old_backup->backup_redirected_cnt--;
 199
 200         if (backup_p)
 201                 backup_p->backup_redirected_cnt++;
 202         rcu_assign_pointer(p->backup_port, backup_p);
 203
 204         return 0;
 205 }
 206
 207 static void nbp_backup_clear(struct net_bridge_port *p)
 208 {
 209         nbp_backup_change(p, NULL);
 210         if (p->backup_redirected_cnt) {
 211                 struct net_bridge_port *cur_p;
 212
 213                 list_for_each_entry(cur_p, &p->br->port_list, list) {
 214                         struct net_bridge_port *backup_p;
 215
 216                         backup_p = rtnl_dereference(cur_p->backup_port);
 217                         if (backup_p == p)
 218                                 nbp_backup_change(cur_p, NULL);
 219                 }
 220         }
 221
 222         WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
 223 }
 224
 225 static void nbp_update_port_count(struct net_bridge *br)
 226 {
 227         struct net_bridge_port *p;
 228         u32 cnt = 0;
 229
 230         list_for_each_entry(p, &br->port_list, list) {
 231                 if (br_auto_port(p))
 232                         cnt++;
 233         }
 234         if (br->auto_cnt != cnt) {
 235                 br->auto_cnt = cnt;
 236                 br_manage_promisc(br);
 237         }
 238 }
 239
 240 static void nbp_delete_promisc(struct net_bridge_port *p)
 241 {
 242         /* If port is currently promiscuous, unset promiscuity.
 243          * Otherwise, it is a static port so remove all addresses
 244          * from it.
 245          */
 246         dev_set_allmulti(p->dev, -1);
 247         if (br_promisc_port(p))
 248                 dev_set_promiscuity(p->dev, -1);
 249         else
 250                 br_fdb_unsync_static(p->br, p);
 251 }
 252
 253 static void release_nbp(struct kobject *kobj)
 254 {
 255         struct net_bridge_port *p
 256                 = container_of(kobj, struct net_bridge_port, kobj);
 257         kfree(p);
 258 }
 259
 260 static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 261 {
 262         struct net_bridge_port *p = kobj_to_brport(kobj);
 263
 264         net_ns_get_ownership(dev_net(p->dev), uid, gid);
 265 }
 266
 267 static struct kobj_type brport_ktype = {
 268 #ifdef CONFIG_SYSFS
 269         .sysfs_ops = &brport_sysfs_ops,
 270 #endif
 271         .release = release_nbp,
 272         .get_ownership = brport_get_ownership,
 273 };
 274
 275 static void destroy_nbp(struct net_bridge_port *p)
 276 {
 277         struct net_device *dev = p->dev;
 278
 279         p->br = NULL;
 280         p->dev = NULL;
 281         dev_put(dev);
 282
 283         kobject_put(&p->kobj);
 284 }
 285
 286 static void destroy_nbp_rcu(struct rcu_head *head)
 287 {
 288         struct net_bridge_port *p =
 289                         container_of(head, struct net_bridge_port, rcu);
 290         destroy_nbp(p);
 291 }
 292
 293 static unsigned get_max_headroom(struct net_bridge *br)
 294 {
 295         unsigned max_headroom = 0;
 296         struct net_bridge_port *p;
 297
 298         list_for_each_entry(p, &br->port_list, list) {
 299                 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
 300
 301                 if (dev_headroom > max_headroom)
 302                         max_headroom = dev_headroom;
 303         }
 304
 305         return max_headroom;
 306 }
 307
 308 static void update_headroom(struct net_bridge *br, int new_hr)
 309 {
 310         struct net_bridge_port *p;
 311
 312         list_for_each_entry(p, &br->port_list, list)
 313                 netdev_set_rx_headroom(p->dev, new_hr);
 314
 315         br->dev->needed_headroom = new_hr;
 316 }
 317
 318 /* Delete port(interface) from bridge is done in two steps.
 319  * via RCU. First step, marks device as down. That deletes
 320  * all the timers and stops new packets from flowing through.
 321  *
 322  * Final cleanup doesn't occur until after all CPU's finished
 323  * processing packets.
 324  *
 325  * Protected from multiple admin operations by RTNL mutex
 326  */
 327 static void del_nbp(struct net_bridge_port *p)
 328 {
 329         struct net_bridge *br = p->br;
 330         struct net_device *dev = p->dev;
 331
 332         sysfs_remove_link(br->ifobj, p->dev->name);
 333
 334         nbp_delete_promisc(p);
 335
 336         spin_lock_bh(&br->lock);
 337         br_stp_disable_port(p);
 338         spin_unlock_bh(&br->lock);
 339
 340         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 341
 342         list_del_rcu(&p->list);
 343         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 344                 update_headroom(br, get_max_headroom(br));
 345         netdev_reset_rx_headroom(dev);
 346
 347         nbp_vlan_flush(p);
 348         br_fdb_delete_by_port(br, p, 0, 1);
 349         switchdev_deferred_process();
 350         nbp_backup_clear(p);
 351
 352         nbp_update_port_count(br);
 353
 354         netdev_upper_dev_unlink(dev, br->dev);
 355
 356         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 357
 358         netdev_rx_handler_unregister(dev);
 359
 360         br_multicast_del_port(p);
 361
 362         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 363         kobject_del(&p->kobj);
 364
 365         br_netpoll_disable(p);
 366
 367         call_rcu(&p->rcu, destroy_nbp_rcu);
 368 }
 369
 370 /* Delete bridge device */
 371 void br_dev_delete(struct net_device *dev, struct list_head *head)
 372 {
 373         struct net_bridge *br = netdev_priv(dev);
 374         struct net_bridge_port *p, *n;
 375
 376         list_for_each_entry_safe(p, n, &br->port_list, list) {
 377                 del_nbp(p);
 378         }
 379
 380         br_recalculate_neigh_suppress_enabled(br);
 381
 382         br_fdb_delete_by_port(br, NULL, 0, 1);
 383
 384         cancel_delayed_work_sync(&br->gc_work);
 385
 386         br_sysfs_delbr(br->dev);
 387         unregister_netdevice_queue(br->dev, head);
 388 }
 389
 390 /* find an available port number */
 391 static int find_portno(struct net_bridge *br)
 392 {
 393         int index;
 394         struct net_bridge_port *p;
 395         unsigned long *inuse;
 396
 397         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 398         if (!inuse)
 399                 return -ENOMEM;
 400
 401         set_bit(0, inuse);      /* zero is reserved */
 402         list_for_each_entry(p, &br->port_list, list) {
 403                 set_bit(p->port_no, inuse);
 404         }
 405         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 406         bitmap_free(inuse);
 407
 408         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 409 }
 410
 411 /* called with RTNL but without bridge lock */
 412 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 413                                        struct net_device *dev)
 414 {
 415         struct net_bridge_port *p;
 416         int index, err;
 417
 418         index = find_portno(br);
 419         if (index < 0)
 420                 return ERR_PTR(index);
 421
 422         p = kzalloc(sizeof(*p), GFP_KERNEL);
 423         if (p == NULL)
 424                 return ERR_PTR(-ENOMEM);
 425
 426         p->br = br;
 427         dev_hold(dev);
 428         p->dev = dev;
 429         p->path_cost = port_cost(dev);
 430         p->priority = 0x8000 >> BR_PORT_BITS;
 431         p->port_no = index;
 432         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 433         br_init_port(p);
 434         br_set_state(p, BR_STATE_DISABLED);
 435         br_stp_port_timer_init(p);
 436         err = br_multicast_add_port(p);
 437         if (err) {
 438                 dev_put(dev);
 439                 kfree(p);
 440                 p = ERR_PTR(err);
 441         }
 442
 443         return p;
 444 }
 445
 446 int br_add_bridge(struct net *net, const char *name)
 447 {
 448         struct net_device *dev;
 449         int res;
 450
 451         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 452                            br_dev_setup);
 453
 454         if (!dev)
 455                 return -ENOMEM;
 456
 457         dev_net_set(dev, net);
 458         dev->rtnl_link_ops = &br_link_ops;
 459
 460         res = register_netdev(dev);
 461         if (res)
 462                 free_netdev(dev);
 463         return res;
 464 }
 465
 466 int br_del_bridge(struct net *net, const char *name)
 467 {
 468         struct net_device *dev;
 469         int ret = 0;
 470
 471         rtnl_lock();
 472         dev = __dev_get_by_name(net, name);
 473         if (dev == NULL)
 474                 ret =  -ENXIO;  /* Could not find device */
 475
 476         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 477                 /* Attempt to delete non bridge device! */
 478                 ret = -EPERM;
 479         }
 480
 481         else if (dev->flags & IFF_UP) {
 482                 /* Not shutdown yet. */
 483                 ret = -EBUSY;
 484         }
 485
 486         else
 487                 br_dev_delete(dev, NULL);
 488
 489         rtnl_unlock();
 490         return ret;
 491 }
 492
 493 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 494 static int br_mtu_min(const struct net_bridge *br)
 495 {
 496         const struct net_bridge_port *p;
 497         int ret_mtu = 0;
 498
 499         list_for_each_entry(p, &br->port_list, list)
 500                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 501                         ret_mtu = p->dev->mtu;
 502
 503         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 504 }
 505
 506 void br_mtu_auto_adjust(struct net_bridge *br)
 507 {
 508         ASSERT_RTNL();
 509
 510         /* if the bridge MTU was manually configured don't mess with it */
 511         if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 512                 return;
 513
 514         /* change to the minimum MTU and clear the flag which was set by
 515          * the bridge ndo_change_mtu callback
 516          */
 517         dev_set_mtu(br->dev, br_mtu_min(br));
 518         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 519 }
 520
 521 static void br_set_gso_limits(struct net_bridge *br)
 522 {
 523         unsigned int gso_max_size = GSO_MAX_SIZE;
 524         u16 gso_max_segs = GSO_MAX_SEGS;
 525         const struct net_bridge_port *p;
 526
 527         list_for_each_entry(p, &br->port_list, list) {
 528                 gso_max_size = min(gso_max_size, p->dev->gso_max_size);
 529                 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
 530         }
 531         br->dev->gso_max_size = gso_max_size;
 532         br->dev->gso_max_segs = gso_max_segs;
 533 }
 534
 535 /*
 536  * Recomputes features using slave's features
 537  */
 538 netdev_features_t br_features_recompute(struct net_bridge *br,
 539         netdev_features_t features)
 540 {
 541         struct net_bridge_port *p;
 542         netdev_features_t mask;
 543
 544         if (list_empty(&br->port_list))
 545                 return features;
 546
 547         mask = features;
 548         features &= ~NETIF_F_ONE_FOR_ALL;
 549
 550         list_for_each_entry(p, &br->port_list, list) {
 551                 features = netdev_increment_features(features,
 552                                                      p->dev->features, mask);
 553         }
 554         features = netdev_add_tso_features(features, mask);
 555
 556         return features;
 557 }
 558
 559 /* called with RTNL */
 560 int br_add_if(struct net_bridge *br, struct net_device *dev,
 561               struct netlink_ext_ack *extack)
 562 {
 563         struct net_bridge_port *p;
 564         int err = 0;
 565         unsigned br_hr, dev_hr;
 566         bool changed_addr;
 567
 568         /* Don't allow bridging non-ethernet like devices, or DSA-enabled
 569          * master network devices since the bridge layer rx_handler prevents
 570          * the DSA fake ethertype handler to be invoked, so we do not strip off
 571          * the DSA switch tag protocol header and the bridge layer just return
 572          * RX_HANDLER_CONSUMED, stopping RX processing for these frames.
 573          */
 574         if ((dev->flags & IFF_LOOPBACK) ||
 575             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 576             !is_valid_ether_addr(dev->dev_addr) ||
 577             netdev_uses_dsa(dev))
 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                 kfree(p);       /* kobject not yet init'd, manually free */
 607                 goto err1;
 608         }
 609
 610         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 611                                    SYSFS_BRIDGE_PORT_ATTR);
 612         if (err)
 613                 goto err2;
 614
 615         err = br_sysfs_addif(p);
 616         if (err)
 617                 goto err2;
 618
 619         err = br_netpoll_enable(p);
 620         if (err)
 621                 goto err3;
 622
 623         err = netdev_rx_handler_register(dev, br_handle_frame, p);
 624         if (err)
 625                 goto err4;
 626
 627         dev->priv_flags |= IFF_BRIDGE_PORT;
 628
 629         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 630         if (err)
 631                 goto err5;
 632
 633         err = nbp_switchdev_mark_set(p);
 634         if (err)
 635                 goto err6;
 636
 637         dev_disable_lro(dev);
 638
 639         list_add_rcu(&p->list, &br->port_list);
 640
 641         nbp_update_port_count(br);
 642
 643         netdev_update_features(br->dev);
 644
 645         br_hr = br->dev->needed_headroom;
 646         dev_hr = netdev_get_fwd_headroom(dev);
 647         if (br_hr < dev_hr)
 648                 update_headroom(br, dev_hr);
 649         else
 650                 netdev_set_rx_headroom(dev, br_hr);
 651
 652         if (br_fdb_insert(br, p, dev->dev_addr, 0))
 653                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 654
 655         if (br->dev->addr_assign_type != NET_ADDR_SET) {
 656                 /* Ask for permission to use this MAC address now, even if we
 657                  * don't end up choosing it below.
 658                  */
 659                 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
 660                 if (err)
 661                         goto err7;
 662         }
 663
 664         err = nbp_vlan_init(p, extack);
 665         if (err) {
 666                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 667                 goto err7;
 668         }
 669
 670         spin_lock_bh(&br->lock);
 671         changed_addr = br_stp_recalculate_bridge_id(br);
 672
 673         if (netif_running(dev) && netif_oper_up(dev) &&
 674             (br->dev->flags & IFF_UP))
 675                 br_stp_enable_port(p);
 676         spin_unlock_bh(&br->lock);
 677
 678         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 679
 680         if (changed_addr)
 681                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 682
 683         br_mtu_auto_adjust(br);
 684         br_set_gso_limits(br);
 685
 686         kobject_uevent(&p->kobj, KOBJ_ADD);
 687
 688         return 0;
 689
 690 err7:
 691         list_del_rcu(&p->list);
 692         br_fdb_delete_by_port(br, p, 0, 1);
 693         nbp_update_port_count(br);
 694 err6:
 695         netdev_upper_dev_unlink(dev, br->dev);
 696 err5:
 697         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 698         netdev_rx_handler_unregister(dev);
 699 err4:
 700         br_netpoll_disable(p);
 701 err3:
 702         sysfs_remove_link(br->ifobj, p->dev->name);
 703 err2:
 704         kobject_put(&p->kobj);
 705         dev_set_allmulti(dev, -1);
 706 err1:
 707         dev_put(dev);
 708         return err;
 709 }
 710
 711 /* called with RTNL */
 712 int br_del_if(struct net_bridge *br, struct net_device *dev)
 713 {
 714         struct net_bridge_port *p;
 715         bool changed_addr;
 716
 717         p = br_port_get_rtnl(dev);
 718         if (!p || p->br != br)
 719                 return -EINVAL;
 720
 721         /* Since more than one interface can be attached to a bridge,
 722          * there still maybe an alternate path for netconsole to use;
 723          * therefore there is no reason for a NETDEV_RELEASE event.
 724          */
 725         del_nbp(p);
 726
 727         br_mtu_auto_adjust(br);
 728         br_set_gso_limits(br);
 729
 730         spin_lock_bh(&br->lock);
 731         changed_addr = br_stp_recalculate_bridge_id(br);
 732         spin_unlock_bh(&br->lock);
 733
 734         if (changed_addr)
 735                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 736
 737         netdev_update_features(br->dev);
 738
 739         return 0;
 740 }
 741
 742 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 743 {
 744         struct net_bridge *br = p->br;
 745
 746         if (mask & BR_AUTO_MASK)
 747                 nbp_update_port_count(br);
 748
 749         if (mask & BR_NEIGH_SUPPRESS)
 750                 br_recalculate_neigh_suppress_enabled(br);
 751 }
 752
 753 bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
 754 {
 755         struct net_bridge_port *p;
 756
 757         p = br_port_get_rtnl_rcu(dev);
 758         if (!p)
 759                 return false;
 760
 761         return p->flags & flag;
 762 }
 763 EXPORT_SYMBOL_GPL(br_port_flag_is_set);