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 ((p->dev->priv_flags & IFF_UNICAST_FLT) &&
 161                             (br->auto_cnt == 0 ||
 162                              (br->auto_cnt == 1 && br_auto_port(p))))
 163                                 br_port_clear_promisc(p);
 164                         else
 165                                 br_port_set_promisc(p);
 166                 }
 167         }
 168 }
 169
 170 int nbp_backup_change(struct net_bridge_port *p,
 171                       struct net_device *backup_dev)
 172 {
 173         struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
 174         struct net_bridge_port *backup_p = NULL;
 175
 176         ASSERT_RTNL();
 177
 178         if (backup_dev) {
 179                 if (!netif_is_bridge_port(backup_dev))
 180                         return -ENOENT;
 181
 182                 backup_p = br_port_get_rtnl(backup_dev);
 183                 if (backup_p->br != p->br)
 184                         return -EINVAL;
 185         }
 186
 187         if (p == backup_p)
 188                 return -EINVAL;
 189
 190         if (old_backup == backup_p)
 191                 return 0;
 192
 193         /* if the backup link is already set, clear it */
 194         if (old_backup)
 195                 old_backup->backup_redirected_cnt--;
 196
 197         if (backup_p)
 198                 backup_p->backup_redirected_cnt++;
 199         rcu_assign_pointer(p->backup_port, backup_p);
 200
 201         return 0;
 202 }
 203
 204 static void nbp_backup_clear(struct net_bridge_port *p)
 205 {
 206         nbp_backup_change(p, NULL);
 207         if (p->backup_redirected_cnt) {
 208                 struct net_bridge_port *cur_p;
 209
 210                 list_for_each_entry(cur_p, &p->br->port_list, list) {
 211                         struct net_bridge_port *backup_p;
 212
 213                         backup_p = rtnl_dereference(cur_p->backup_port);
 214                         if (backup_p == p)
 215                                 nbp_backup_change(cur_p, NULL);
 216                 }
 217         }
 218
 219         WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
 220 }
 221
 222 static void nbp_update_port_count(struct net_bridge *br)
 223 {
 224         struct net_bridge_port *p;
 225         u32 cnt = 0;
 226
 227         list_for_each_entry(p, &br->port_list, list) {
 228                 if (br_auto_port(p))
 229                         cnt++;
 230         }
 231         if (br->auto_cnt != cnt) {
 232                 br->auto_cnt = cnt;
 233                 br_manage_promisc(br);
 234         }
 235 }
 236
 237 static void nbp_delete_promisc(struct net_bridge_port *p)
 238 {
 239         /* If port is currently promiscuous, unset promiscuity.
 240          * Otherwise, it is a static port so remove all addresses
 241          * from it.
 242          */
 243         dev_set_allmulti(p->dev, -1);
 244         if (br_promisc_port(p))
 245                 dev_set_promiscuity(p->dev, -1);
 246         else
 247                 br_fdb_unsync_static(p->br, p);
 248 }
 249
 250 static void release_nbp(struct kobject *kobj)
 251 {
 252         struct net_bridge_port *p
 253                 = container_of(kobj, struct net_bridge_port, kobj);
 254         kfree(p);
 255 }
 256
 257 static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 258 {
 259         struct net_bridge_port *p = kobj_to_brport(kobj);
 260
 261         net_ns_get_ownership(dev_net(p->dev), uid, gid);
 262 }
 263
 264 static struct kobj_type brport_ktype = {
 265 #ifdef CONFIG_SYSFS
 266         .sysfs_ops = &brport_sysfs_ops,
 267 #endif
 268         .release = release_nbp,
 269         .get_ownership = brport_get_ownership,
 270 };
 271
 272 static void destroy_nbp(struct net_bridge_port *p)
 273 {
 274         struct net_device *dev = p->dev;
 275
 276         p->br = NULL;
 277         p->dev = NULL;
 278         dev_put(dev);
 279
 280         kobject_put(&p->kobj);
 281 }
 282
 283 static void destroy_nbp_rcu(struct rcu_head *head)
 284 {
 285         struct net_bridge_port *p =
 286                         container_of(head, struct net_bridge_port, rcu);
 287         destroy_nbp(p);
 288 }
 289
 290 static unsigned get_max_headroom(struct net_bridge *br)
 291 {
 292         unsigned max_headroom = 0;
 293         struct net_bridge_port *p;
 294
 295         list_for_each_entry(p, &br->port_list, list) {
 296                 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
 297
 298                 if (dev_headroom > max_headroom)
 299                         max_headroom = dev_headroom;
 300         }
 301
 302         return max_headroom;
 303 }
 304
 305 static void update_headroom(struct net_bridge *br, int new_hr)
 306 {
 307         struct net_bridge_port *p;
 308
 309         list_for_each_entry(p, &br->port_list, list)
 310                 netdev_set_rx_headroom(p->dev, new_hr);
 311
 312         br->dev->needed_headroom = new_hr;
 313 }
 314
 315 /* Delete port(interface) from bridge is done in two steps.
 316  * via RCU. First step, marks device as down. That deletes
 317  * all the timers and stops new packets from flowing through.
 318  *
 319  * Final cleanup doesn't occur until after all CPU's finished
 320  * processing packets.
 321  *
 322  * Protected from multiple admin operations by RTNL mutex
 323  */
 324 static void del_nbp(struct net_bridge_port *p)
 325 {
 326         struct net_bridge *br = p->br;
 327         struct net_device *dev = p->dev;
 328
 329         sysfs_remove_link(br->ifobj, p->dev->name);
 330
 331         nbp_delete_promisc(p);
 332
 333         spin_lock_bh(&br->lock);
 334         br_stp_disable_port(p);
 335         spin_unlock_bh(&br->lock);
 336
 337         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 338
 339         list_del_rcu(&p->list);
 340         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 341                 update_headroom(br, get_max_headroom(br));
 342         netdev_reset_rx_headroom(dev);
 343
 344         nbp_vlan_flush(p);
 345         br_fdb_delete_by_port(br, p, 0, 1);
 346         switchdev_deferred_process();
 347         nbp_backup_clear(p);
 348
 349         nbp_update_port_count(br);
 350
 351         netdev_upper_dev_unlink(dev, br->dev);
 352
 353         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 354
 355         netdev_rx_handler_unregister(dev);
 356
 357         br_multicast_del_port(p);
 358
 359         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 360         kobject_del(&p->kobj);
 361
 362         br_netpoll_disable(p);
 363
 364         call_rcu(&p->rcu, destroy_nbp_rcu);
 365 }
 366
 367 /* Delete bridge device */
 368 void br_dev_delete(struct net_device *dev, struct list_head *head)
 369 {
 370         struct net_bridge *br = netdev_priv(dev);
 371         struct net_bridge_port *p, *n;
 372
 373         list_for_each_entry_safe(p, n, &br->port_list, list) {
 374                 del_nbp(p);
 375         }
 376
 377         br_recalculate_neigh_suppress_enabled(br);
 378
 379         br_fdb_delete_by_port(br, NULL, 0, 1);
 380
 381         cancel_delayed_work_sync(&br->gc_work);
 382
 383         br_sysfs_delbr(br->dev);
 384         unregister_netdevice_queue(br->dev, head);
 385 }
 386
 387 /* find an available port number */
 388 static int find_portno(struct net_bridge *br)
 389 {
 390         int index;
 391         struct net_bridge_port *p;
 392         unsigned long *inuse;
 393
 394         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 395         if (!inuse)
 396                 return -ENOMEM;
 397
 398         set_bit(0, inuse);      /* zero is reserved */
 399         list_for_each_entry(p, &br->port_list, list) {
 400                 set_bit(p->port_no, inuse);
 401         }
 402         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 403         bitmap_free(inuse);
 404
 405         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 406 }
 407
 408 /* called with RTNL but without bridge lock */
 409 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 410                                        struct net_device *dev)
 411 {
 412         struct net_bridge_port *p;
 413         int index, err;
 414
 415         index = find_portno(br);
 416         if (index < 0)
 417                 return ERR_PTR(index);
 418
 419         p = kzalloc(sizeof(*p), GFP_KERNEL);
 420         if (p == NULL)
 421                 return ERR_PTR(-ENOMEM);
 422
 423         p->br = br;
 424         dev_hold(dev);
 425         p->dev = dev;
 426         p->path_cost = port_cost(dev);
 427         p->priority = 0x8000 >> BR_PORT_BITS;
 428         p->port_no = index;
 429         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 430         br_init_port(p);
 431         br_set_state(p, BR_STATE_DISABLED);
 432         br_stp_port_timer_init(p);
 433         err = br_multicast_add_port(p);
 434         if (err) {
 435                 dev_put(dev);
 436                 kfree(p);
 437                 p = ERR_PTR(err);
 438         }
 439
 440         return p;
 441 }
 442
 443 int br_add_bridge(struct net *net, const char *name)
 444 {
 445         struct net_device *dev;
 446         int res;
 447
 448         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 449                            br_dev_setup);
 450
 451         if (!dev)
 452                 return -ENOMEM;
 453
 454         dev_net_set(dev, net);
 455         dev->rtnl_link_ops = &br_link_ops;
 456
 457         res = register_netdev(dev);
 458         if (res)
 459                 free_netdev(dev);
 460         return res;
 461 }
 462
 463 int br_del_bridge(struct net *net, const char *name)
 464 {
 465         struct net_device *dev;
 466         int ret = 0;
 467
 468         rtnl_lock();
 469         dev = __dev_get_by_name(net, name);
 470         if (dev == NULL)
 471                 ret =  -ENXIO;  /* Could not find device */
 472
 473         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 474                 /* Attempt to delete non bridge device! */
 475                 ret = -EPERM;
 476         }
 477
 478         else if (dev->flags & IFF_UP) {
 479                 /* Not shutdown yet. */
 480                 ret = -EBUSY;
 481         }
 482
 483         else
 484                 br_dev_delete(dev, NULL);
 485
 486         rtnl_unlock();
 487         return ret;
 488 }
 489
 490 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 491 static int br_mtu_min(const struct net_bridge *br)
 492 {
 493         const struct net_bridge_port *p;
 494         int ret_mtu = 0;
 495
 496         list_for_each_entry(p, &br->port_list, list)
 497                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 498                         ret_mtu = p->dev->mtu;
 499
 500         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 501 }
 502
 503 void br_mtu_auto_adjust(struct net_bridge *br)
 504 {
 505         ASSERT_RTNL();
 506
 507         /* if the bridge MTU was manually configured don't mess with it */
 508         if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 509                 return;
 510
 511         /* change to the minimum MTU and clear the flag which was set by
 512          * the bridge ndo_change_mtu callback
 513          */
 514         dev_set_mtu(br->dev, br_mtu_min(br));
 515         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 516 }
 517
 518 static void br_set_gso_limits(struct net_bridge *br)
 519 {
 520         unsigned int gso_max_size = GSO_MAX_SIZE;
 521         u16 gso_max_segs = GSO_MAX_SEGS;
 522         const struct net_bridge_port *p;
 523
 524         list_for_each_entry(p, &br->port_list, list) {
 525                 gso_max_size = min(gso_max_size, p->dev->gso_max_size);
 526                 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
 527         }
 528         br->dev->gso_max_size = gso_max_size;
 529         br->dev->gso_max_segs = gso_max_segs;
 530 }
 531
 532 /*
 533  * Recomputes features using slave's features
 534  */
 535 netdev_features_t br_features_recompute(struct net_bridge *br,
 536         netdev_features_t features)
 537 {
 538         struct net_bridge_port *p;
 539         netdev_features_t mask;
 540
 541         if (list_empty(&br->port_list))
 542                 return features;
 543
 544         mask = features;
 545         features &= ~NETIF_F_ONE_FOR_ALL;
 546
 547         list_for_each_entry(p, &br->port_list, list) {
 548                 features = netdev_increment_features(features,
 549                                                      p->dev->features, mask);
 550         }
 551         features = netdev_add_tso_features(features, mask);
 552
 553         return features;
 554 }
 555
 556 /* called with RTNL */
 557 int br_add_if(struct net_bridge *br, struct net_device *dev,
 558               struct netlink_ext_ack *extack)
 559 {
 560         struct net_bridge_port *p;
 561         int err = 0;
 562         unsigned br_hr, dev_hr;
 563         bool changed_addr, fdb_synced = false;
 564
 565         /* Don't allow bridging non-ethernet like devices, or DSA-enabled
 566          * master network devices since the bridge layer rx_handler prevents
 567          * the DSA fake ethertype handler to be invoked, so we do not strip off
 568          * the DSA switch tag protocol header and the bridge layer just return
 569          * RX_HANDLER_CONSUMED, stopping RX processing for these frames.
 570          */
 571         if ((dev->flags & IFF_LOOPBACK) ||
 572             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 573             !is_valid_ether_addr(dev->dev_addr) ||
 574             netdev_uses_dsa(dev))
 575                 return -EINVAL;
 576
 577         /* No bridging of bridges */
 578         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
 579                 NL_SET_ERR_MSG(extack,
 580                                "Can not enslave a bridge to a bridge");
 581                 return -ELOOP;
 582         }
 583
 584         /* Device has master upper dev */
 585         if (netdev_master_upper_dev_get(dev))
 586                 return -EBUSY;
 587
 588         /* No bridging devices that dislike that (e.g. wireless) */
 589         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 590                 NL_SET_ERR_MSG(extack,
 591                                "Device does not allow enslaving to a bridge");
 592                 return -EOPNOTSUPP;
 593         }
 594
 595         p = new_nbp(br, dev);
 596         if (IS_ERR(p))
 597                 return PTR_ERR(p);
 598
 599         call_netdevice_notifiers(NETDEV_JOIN, dev);
 600
 601         err = dev_set_allmulti(dev, 1);
 602         if (err) {
 603                 br_multicast_del_port(p);
 604                 kfree(p);       /* kobject not yet init'd, manually free */
 605                 goto err1;
 606         }
 607
 608         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 609                                    SYSFS_BRIDGE_PORT_ATTR);
 610         if (err)
 611                 goto err2;
 612
 613         err = br_sysfs_addif(p);
 614         if (err)
 615                 goto err2;
 616
 617         err = br_netpoll_enable(p);
 618         if (err)
 619                 goto err3;
 620
 621         err = netdev_rx_handler_register(dev, br_handle_frame, p);
 622         if (err)
 623                 goto err4;
 624
 625         dev->priv_flags |= IFF_BRIDGE_PORT;
 626
 627         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 628         if (err)
 629                 goto err5;
 630
 631         err = nbp_switchdev_mark_set(p);
 632         if (err)
 633                 goto err6;
 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_insert(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 err7;
 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 err7;
 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 err7:
 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 err6:
 708         netdev_upper_dev_unlink(dev, br->dev);
 709 err5:
 710         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 711         netdev_rx_handler_unregister(dev);
 712 err4:
 713         br_netpoll_disable(p);
 714 err3:
 715         sysfs_remove_link(br->ifobj, p->dev->name);
 716 err2:
 717         br_multicast_del_port(p);
 718         kobject_put(&p->kobj);
 719         dev_set_allmulti(dev, -1);
 720 err1:
 721         dev_put(dev);
 722         return err;
 723 }
 724
 725 /* called with RTNL */
 726 int br_del_if(struct net_bridge *br, struct net_device *dev)
 727 {
 728         struct net_bridge_port *p;
 729         bool changed_addr;
 730
 731         p = br_port_get_rtnl(dev);
 732         if (!p || p->br != br)
 733                 return -EINVAL;
 734
 735         /* Since more than one interface can be attached to a bridge,
 736          * there still maybe an alternate path for netconsole to use;
 737          * therefore there is no reason for a NETDEV_RELEASE event.
 738          */
 739         del_nbp(p);
 740
 741         br_mtu_auto_adjust(br);
 742         br_set_gso_limits(br);
 743
 744         spin_lock_bh(&br->lock);
 745         changed_addr = br_stp_recalculate_bridge_id(br);
 746         spin_unlock_bh(&br->lock);
 747
 748         if (changed_addr)
 749                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 750
 751         netdev_update_features(br->dev);
 752
 753         return 0;
 754 }
 755
 756 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 757 {
 758         struct net_bridge *br = p->br;
 759
 760         if (mask & BR_AUTO_MASK)
 761                 nbp_update_port_count(br);
 762
 763         if (mask & BR_NEIGH_SUPPRESS)
 764                 br_recalculate_neigh_suppress_enabled(br);
 765 }
 766
 767 bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
 768 {
 769         struct net_bridge_port *p;
 770
 771         p = br_port_get_rtnl_rcu(dev);
 772         if (!p)
 773                 return false;
 774
 775         return p->flags & flag;
 776 }
 777 EXPORT_SYMBOL_GPL(br_port_flag_is_set);