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 (!br_port_exists(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 = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
 398                         GFP_KERNEL);
 399         if (!inuse)
 400                 return -ENOMEM;
 401
 402         set_bit(0, inuse);      /* zero is reserved */
 403         list_for_each_entry(p, &br->port_list, list) {
 404                 set_bit(p->port_no, inuse);
 405         }
 406         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 407         kfree(inuse);
 408
 409         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 410 }
 411
 412 /* called with RTNL but without bridge lock */
 413 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 414                                        struct net_device *dev)
 415 {
 416         struct net_bridge_port *p;
 417         int index, err;
 418
 419         index = find_portno(br);
 420         if (index < 0)
 421                 return ERR_PTR(index);
 422
 423         p = kzalloc(sizeof(*p), GFP_KERNEL);
 424         if (p == NULL)
 425                 return ERR_PTR(-ENOMEM);
 426
 427         p->br = br;
 428         dev_hold(dev);
 429         p->dev = dev;
 430         p->path_cost = port_cost(dev);
 431         p->priority = 0x8000 >> BR_PORT_BITS;
 432         p->port_no = index;
 433         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 434         br_init_port(p);
 435         br_set_state(p, BR_STATE_DISABLED);
 436         br_stp_port_timer_init(p);
 437         err = br_multicast_add_port(p);
 438         if (err) {
 439                 dev_put(dev);
 440                 kfree(p);
 441                 p = ERR_PTR(err);
 442         }
 443
 444         return p;
 445 }
 446
 447 int br_add_bridge(struct net *net, const char *name)
 448 {
 449         struct net_device *dev;
 450         int res;
 451
 452         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 453                            br_dev_setup);
 454
 455         if (!dev)
 456                 return -ENOMEM;
 457
 458         dev_net_set(dev, net);
 459         dev->rtnl_link_ops = &br_link_ops;
 460
 461         res = register_netdev(dev);
 462         if (res)
 463                 free_netdev(dev);
 464         return res;
 465 }
 466
 467 int br_del_bridge(struct net *net, const char *name)
 468 {
 469         struct net_device *dev;
 470         int ret = 0;
 471
 472         rtnl_lock();
 473         dev = __dev_get_by_name(net, name);
 474         if (dev == NULL)
 475                 ret =  -ENXIO;  /* Could not find device */
 476
 477         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 478                 /* Attempt to delete non bridge device! */
 479                 ret = -EPERM;
 480         }
 481
 482         else if (dev->flags & IFF_UP) {
 483                 /* Not shutdown yet. */
 484                 ret = -EBUSY;
 485         }
 486
 487         else
 488                 br_dev_delete(dev, NULL);
 489
 490         rtnl_unlock();
 491         return ret;
 492 }
 493
 494 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 495 static int br_mtu_min(const struct net_bridge *br)
 496 {
 497         const struct net_bridge_port *p;
 498         int ret_mtu = 0;
 499
 500         list_for_each_entry(p, &br->port_list, list)
 501                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 502                         ret_mtu = p->dev->mtu;
 503
 504         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 505 }
 506
 507 void br_mtu_auto_adjust(struct net_bridge *br)
 508 {
 509         ASSERT_RTNL();
 510
 511         /* if the bridge MTU was manually configured don't mess with it */
 512         if (br->mtu_set_by_user)
 513                 return;
 514
 515         /* change to the minimum MTU and clear the flag which was set by
 516          * the bridge ndo_change_mtu callback
 517          */
 518         dev_set_mtu(br->dev, br_mtu_min(br));
 519         br->mtu_set_by_user = false;
 520 }
 521
 522 static void br_set_gso_limits(struct net_bridge *br)
 523 {
 524         unsigned int gso_max_size = GSO_MAX_SIZE;
 525         u16 gso_max_segs = GSO_MAX_SEGS;
 526         const struct net_bridge_port *p;
 527
 528         list_for_each_entry(p, &br->port_list, list) {
 529                 gso_max_size = min(gso_max_size, p->dev->gso_max_size);
 530                 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
 531         }
 532         br->dev->gso_max_size = gso_max_size;
 533         br->dev->gso_max_segs = gso_max_segs;
 534 }
 535
 536 /*
 537  * Recomputes features using slave's features
 538  */
 539 netdev_features_t br_features_recompute(struct net_bridge *br,
 540         netdev_features_t features)
 541 {
 542         struct net_bridge_port *p;
 543         netdev_features_t mask;
 544
 545         if (list_empty(&br->port_list))
 546                 return features;
 547
 548         mask = features;
 549         features &= ~NETIF_F_ONE_FOR_ALL;
 550
 551         list_for_each_entry(p, &br->port_list, list) {
 552                 features = netdev_increment_features(features,
 553                                                      p->dev->features, mask);
 554         }
 555         features = netdev_add_tso_features(features, mask);
 556
 557         return features;
 558 }
 559
 560 /* called with RTNL */
 561 int br_add_if(struct net_bridge *br, struct net_device *dev,
 562               struct netlink_ext_ack *extack)
 563 {
 564         struct net_bridge_port *p;
 565         int err = 0;
 566         unsigned br_hr, dev_hr;
 567         bool changed_addr, fdb_synced = false;
 568
 569         /* Don't allow bridging non-ethernet like devices, or DSA-enabled
 570          * master network devices since the bridge layer rx_handler prevents
 571          * the DSA fake ethertype handler to be invoked, so we do not strip off
 572          * the DSA switch tag protocol header and the bridge layer just return
 573          * RX_HANDLER_CONSUMED, stopping RX processing for these frames.
 574          */
 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             netdev_uses_dsa(dev))
 579                 return -EINVAL;
 580
 581         /* No bridging of bridges */
 582         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
 583                 NL_SET_ERR_MSG(extack,
 584                                "Can not enslave a bridge to a bridge");
 585                 return -ELOOP;
 586         }
 587
 588         /* Device has master upper dev */
 589         if (netdev_master_upper_dev_get(dev))
 590                 return -EBUSY;
 591
 592         /* No bridging devices that dislike that (e.g. wireless) */
 593         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 594                 NL_SET_ERR_MSG(extack,
 595                                "Device does not allow enslaving to a bridge");
 596                 return -EOPNOTSUPP;
 597         }
 598
 599         p = new_nbp(br, dev);
 600         if (IS_ERR(p))
 601                 return PTR_ERR(p);
 602
 603         call_netdevice_notifiers(NETDEV_JOIN, dev);
 604
 605         err = dev_set_allmulti(dev, 1);
 606         if (err) {
 607                 br_multicast_del_port(p);
 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_handle_frame, 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         err = nbp_switchdev_mark_set(p);
 636         if (err)
 637                 goto err6;
 638
 639         dev_disable_lro(dev);
 640
 641         list_add_rcu(&p->list, &br->port_list);
 642
 643         nbp_update_port_count(br);
 644         if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) {
 645                 /* When updating the port count we also update all ports'
 646                  * promiscuous mode.
 647                  * A port leaving promiscuous mode normally gets the bridge's
 648                  * fdb synced to the unicast filter (if supported), however,
 649                  * `br_port_clear_promisc` does not distinguish between
 650                  * non-promiscuous ports and *new* ports, so we need to
 651                  * sync explicitly here.
 652                  */
 653                 fdb_synced = br_fdb_sync_static(br, p) == 0;
 654                 if (!fdb_synced)
 655                         netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n");
 656         }
 657
 658         netdev_update_features(br->dev);
 659
 660         br_hr = br->dev->needed_headroom;
 661         dev_hr = netdev_get_fwd_headroom(dev);
 662         if (br_hr < dev_hr)
 663                 update_headroom(br, dev_hr);
 664         else
 665                 netdev_set_rx_headroom(dev, br_hr);
 666
 667         if (br_fdb_insert(br, p, dev->dev_addr, 0))
 668                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 669
 670         err = nbp_vlan_init(p);
 671         if (err) {
 672                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 673                 goto err7;
 674         }
 675
 676         spin_lock_bh(&br->lock);
 677         changed_addr = br_stp_recalculate_bridge_id(br);
 678
 679         if (netif_running(dev) && netif_oper_up(dev) &&
 680             (br->dev->flags & IFF_UP))
 681                 br_stp_enable_port(p);
 682         spin_unlock_bh(&br->lock);
 683
 684         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 685
 686         if (changed_addr)
 687                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 688
 689         br_mtu_auto_adjust(br);
 690         br_set_gso_limits(br);
 691
 692         kobject_uevent(&p->kobj, KOBJ_ADD);
 693
 694         return 0;
 695
 696 err7:
 697         if (fdb_synced)
 698                 br_fdb_unsync_static(br, p);
 699         list_del_rcu(&p->list);
 700         br_fdb_delete_by_port(br, p, 0, 1);
 701         nbp_update_port_count(br);
 702 err6:
 703         netdev_upper_dev_unlink(dev, br->dev);
 704 err5:
 705         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 706         netdev_rx_handler_unregister(dev);
 707 err4:
 708         br_netpoll_disable(p);
 709 err3:
 710         sysfs_remove_link(br->ifobj, p->dev->name);
 711 err2:
 712         br_multicast_del_port(p);
 713         kobject_put(&p->kobj);
 714         dev_set_allmulti(dev, -1);
 715 err1:
 716         dev_put(dev);
 717         return err;
 718 }
 719
 720 /* called with RTNL */
 721 int br_del_if(struct net_bridge *br, struct net_device *dev)
 722 {
 723         struct net_bridge_port *p;
 724         bool changed_addr;
 725
 726         p = br_port_get_rtnl(dev);
 727         if (!p || p->br != br)
 728                 return -EINVAL;
 729
 730         /* Since more than one interface can be attached to a bridge,
 731          * there still maybe an alternate path for netconsole to use;
 732          * therefore there is no reason for a NETDEV_RELEASE event.
 733          */
 734         del_nbp(p);
 735
 736         br_mtu_auto_adjust(br);
 737         br_set_gso_limits(br);
 738
 739         spin_lock_bh(&br->lock);
 740         changed_addr = br_stp_recalculate_bridge_id(br);
 741         spin_unlock_bh(&br->lock);
 742
 743         if (changed_addr)
 744                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 745
 746         netdev_update_features(br->dev);
 747
 748         return 0;
 749 }
 750
 751 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 752 {
 753         struct net_bridge *br = p->br;
 754
 755         if (mask & BR_AUTO_MASK)
 756                 nbp_update_port_count(br);
 757
 758         if (mask & BR_NEIGH_SUPPRESS)
 759                 br_recalculate_neigh_suppress_enabled(br);
 760 }