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_mrp_port_del(br, p);
 337         br_cfm_port_del(br, p);
 338
 339         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 340
 341         list_del_rcu(&p->list);
 342         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 343                 update_headroom(br, get_max_headroom(br));
 344         netdev_reset_rx_headroom(dev);
 345
 346         nbp_vlan_flush(p);
 347         br_fdb_delete_by_port(br, p, 0, 1);
 348         switchdev_deferred_process();
 349         nbp_backup_clear(p);
 350
 351         nbp_update_port_count(br);
 352
 353         netdev_upper_dev_unlink(dev, br->dev);
 354
 355         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 356
 357         netdev_rx_handler_unregister(dev);
 358
 359         br_multicast_del_port(p);
 360
 361         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 362         kobject_del(&p->kobj);
 363
 364         br_netpoll_disable(p);
 365
 366         call_rcu(&p->rcu, destroy_nbp_rcu);
 367 }
 368
 369 /* Delete bridge device */
 370 void br_dev_delete(struct net_device *dev, struct list_head *head)
 371 {
 372         struct net_bridge *br = netdev_priv(dev);
 373         struct net_bridge_port *p, *n;
 374
 375         list_for_each_entry_safe(p, n, &br->port_list, list) {
 376                 del_nbp(p);
 377         }
 378
 379         br_recalculate_neigh_suppress_enabled(br);
 380
 381         br_fdb_delete_by_port(br, NULL, 0, 1);
 382
 383         cancel_delayed_work_sync(&br->gc_work);
 384
 385         br_sysfs_delbr(br->dev);
 386         unregister_netdevice_queue(br->dev, head);
 387 }
 388
 389 /* find an available port number */
 390 static int find_portno(struct net_bridge *br)
 391 {
 392         int index;
 393         struct net_bridge_port *p;
 394         unsigned long *inuse;
 395
 396         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 397         if (!inuse)
 398                 return -ENOMEM;
 399
 400         set_bit(0, inuse);      /* zero is reserved */
 401         list_for_each_entry(p, &br->port_list, list) {
 402                 set_bit(p->port_no, inuse);
 403         }
 404         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 405         bitmap_free(inuse);
 406
 407         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 408 }
 409
 410 /* called with RTNL but without bridge lock */
 411 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 412                                        struct net_device *dev)
 413 {
 414         struct net_bridge_port *p;
 415         int index, err;
 416
 417         index = find_portno(br);
 418         if (index < 0)
 419                 return ERR_PTR(index);
 420
 421         p = kzalloc(sizeof(*p), GFP_KERNEL);
 422         if (p == NULL)
 423                 return ERR_PTR(-ENOMEM);
 424
 425         p->br = br;
 426         dev_hold(dev);
 427         p->dev = dev;
 428         p->path_cost = port_cost(dev);
 429         p->priority = 0x8000 >> BR_PORT_BITS;
 430         p->port_no = index;
 431         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 432         br_init_port(p);
 433         br_set_state(p, BR_STATE_DISABLED);
 434         br_stp_port_timer_init(p);
 435         err = br_multicast_add_port(p);
 436         if (err) {
 437                 dev_put(dev);
 438                 kfree(p);
 439                 p = ERR_PTR(err);
 440         }
 441
 442         return p;
 443 }
 444
 445 int br_add_bridge(struct net *net, const char *name)
 446 {
 447         struct net_device *dev;
 448         int res;
 449
 450         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 451                            br_dev_setup);
 452
 453         if (!dev)
 454                 return -ENOMEM;
 455
 456         dev_net_set(dev, net);
 457         dev->rtnl_link_ops = &br_link_ops;
 458
 459         res = register_netdevice(dev);
 460         if (res)
 461                 free_netdev(dev);
 462         return res;
 463 }
 464
 465 int br_del_bridge(struct net *net, const char *name)
 466 {
 467         struct net_device *dev;
 468         int ret = 0;
 469
 470         dev = __dev_get_by_name(net, name);
 471         if (dev == NULL)
 472                 ret =  -ENXIO;  /* Could not find device */
 473
 474         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 475                 /* Attempt to delete non bridge device! */
 476                 ret = -EPERM;
 477         }
 478
 479         else if (dev->flags & IFF_UP) {
 480                 /* Not shutdown yet. */
 481                 ret = -EBUSY;
 482         }
 483
 484         else
 485                 br_dev_delete(dev, NULL);
 486
 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. */
 566         if ((dev->flags & IFF_LOOPBACK) ||
 567             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 568             !is_valid_ether_addr(dev->dev_addr))
 569                 return -EINVAL;
 570
 571         /* Also don't allow bridging of net devices that are DSA masters, since
 572          * the bridge layer rx_handler prevents the DSA fake ethertype handler
 573          * to be invoked, so we don't get the chance to strip off and parse the
 574          * DSA switch tag protocol header (the bridge layer just returns
 575          * RX_HANDLER_CONSUMED, stopping RX processing for these frames).
 576          * The only case where that would not be an issue is when bridging can
 577          * already be offloaded, such as when the DSA master is itself a DSA
 578          * or plain switchdev port, and is bridged only with other ports from
 579          * the same hardware device.
 580          */
 581         if (netdev_uses_dsa(dev)) {
 582                 list_for_each_entry(p, &br->port_list, list) {
 583                         if (!netdev_port_same_parent_id(dev, p->dev)) {
 584                                 NL_SET_ERR_MSG(extack,
 585                                                "Cannot do software bridging with a DSA master");
 586                                 return -EINVAL;
 587                         }
 588                 }
 589         }
 590
 591         /* No bridging of bridges */
 592         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
 593                 NL_SET_ERR_MSG(extack,
 594                                "Can not enslave a bridge to a bridge");
 595                 return -ELOOP;
 596         }
 597
 598         /* Device has master upper dev */
 599         if (netdev_master_upper_dev_get(dev))
 600                 return -EBUSY;
 601
 602         /* No bridging devices that dislike that (e.g. wireless) */
 603         if (dev->priv_flags & IFF_DONT_BRIDGE) {
 604                 NL_SET_ERR_MSG(extack,
 605                                "Device does not allow enslaving to a bridge");
 606                 return -EOPNOTSUPP;
 607         }
 608
 609         p = new_nbp(br, dev);
 610         if (IS_ERR(p))
 611                 return PTR_ERR(p);
 612
 613         call_netdevice_notifiers(NETDEV_JOIN, dev);
 614
 615         err = dev_set_allmulti(dev, 1);
 616         if (err) {
 617                 br_multicast_del_port(p);
 618                 kfree(p);       /* kobject not yet init'd, manually free */
 619                 goto err1;
 620         }
 621
 622         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 623                                    SYSFS_BRIDGE_PORT_ATTR);
 624         if (err)
 625                 goto err2;
 626
 627         err = br_sysfs_addif(p);
 628         if (err)
 629                 goto err2;
 630
 631         err = br_netpoll_enable(p);
 632         if (err)
 633                 goto err3;
 634
 635         err = netdev_rx_handler_register(dev, br_get_rx_handler(dev), p);
 636         if (err)
 637                 goto err4;
 638
 639         dev->priv_flags |= IFF_BRIDGE_PORT;
 640
 641         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 642         if (err)
 643                 goto err5;
 644
 645         dev_disable_lro(dev);
 646
 647         list_add_rcu(&p->list, &br->port_list);
 648
 649         nbp_update_port_count(br);
 650         if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) {
 651                 /* When updating the port count we also update all ports'
 652                  * promiscuous mode.
 653                  * A port leaving promiscuous mode normally gets the bridge's
 654                  * fdb synced to the unicast filter (if supported), however,
 655                  * `br_port_clear_promisc` does not distinguish between
 656                  * non-promiscuous ports and *new* ports, so we need to
 657                  * sync explicitly here.
 658                  */
 659                 fdb_synced = br_fdb_sync_static(br, p) == 0;
 660                 if (!fdb_synced)
 661                         netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n");
 662         }
 663
 664         netdev_update_features(br->dev);
 665
 666         br_hr = br->dev->needed_headroom;
 667         dev_hr = netdev_get_fwd_headroom(dev);
 668         if (br_hr < dev_hr)
 669                 update_headroom(br, dev_hr);
 670         else
 671                 netdev_set_rx_headroom(dev, br_hr);
 672
 673         if (br_fdb_insert(br, p, dev->dev_addr, 0))
 674                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 675
 676         if (br->dev->addr_assign_type != NET_ADDR_SET) {
 677                 /* Ask for permission to use this MAC address now, even if we
 678                  * don't end up choosing it below.
 679                  */
 680                 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
 681                 if (err)
 682                         goto err6;
 683         }
 684
 685         err = nbp_vlan_init(p, extack);
 686         if (err) {
 687                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 688                 goto err6;
 689         }
 690
 691         spin_lock_bh(&br->lock);
 692         changed_addr = br_stp_recalculate_bridge_id(br);
 693
 694         if (netif_running(dev) && netif_oper_up(dev) &&
 695             (br->dev->flags & IFF_UP))
 696                 br_stp_enable_port(p);
 697         spin_unlock_bh(&br->lock);
 698
 699         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 700
 701         if (changed_addr)
 702                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 703
 704         br_mtu_auto_adjust(br);
 705         br_set_gso_limits(br);
 706
 707         kobject_uevent(&p->kobj, KOBJ_ADD);
 708
 709         return 0;
 710
 711 err6:
 712         if (fdb_synced)
 713                 br_fdb_unsync_static(br, p);
 714         list_del_rcu(&p->list);
 715         br_fdb_delete_by_port(br, p, 0, 1);
 716         nbp_update_port_count(br);
 717         netdev_upper_dev_unlink(dev, br->dev);
 718 err5:
 719         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 720         netdev_rx_handler_unregister(dev);
 721 err4:
 722         br_netpoll_disable(p);
 723 err3:
 724         sysfs_remove_link(br->ifobj, p->dev->name);
 725 err2:
 726         br_multicast_del_port(p);
 727         kobject_put(&p->kobj);
 728         dev_set_allmulti(dev, -1);
 729 err1:
 730         dev_put(dev);
 731         return err;
 732 }
 733
 734 /* called with RTNL */
 735 int br_del_if(struct net_bridge *br, struct net_device *dev)
 736 {
 737         struct net_bridge_port *p;
 738         bool changed_addr;
 739
 740         p = br_port_get_rtnl(dev);
 741         if (!p || p->br != br)
 742                 return -EINVAL;
 743
 744         /* Since more than one interface can be attached to a bridge,
 745          * there still maybe an alternate path for netconsole to use;
 746          * therefore there is no reason for a NETDEV_RELEASE event.
 747          */
 748         del_nbp(p);
 749
 750         br_mtu_auto_adjust(br);
 751         br_set_gso_limits(br);
 752
 753         spin_lock_bh(&br->lock);
 754         changed_addr = br_stp_recalculate_bridge_id(br);
 755         spin_unlock_bh(&br->lock);
 756
 757         if (changed_addr)
 758                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 759
 760         netdev_update_features(br->dev);
 761
 762         return 0;
 763 }
 764
 765 void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 766 {
 767         struct net_bridge *br = p->br;
 768
 769         if (mask & BR_AUTO_MASK)
 770                 nbp_update_port_count(br);
 771
 772         if (mask & BR_NEIGH_SUPPRESS)
 773                 br_recalculate_neigh_suppress_enabled(br);
 774 }
 775
 776 bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
 777 {
 778         struct net_bridge_port *p;
 779
 780         p = br_port_get_rtnl_rcu(dev);
 781         if (!p)
 782                 return false;
 783
 784         return p->flags & flag;
 785 }
 786 EXPORT_SYMBOL_GPL(br_port_flag_is_set);