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_5000:
  44                         return 3;
  45                 case SPEED_2500:
  46                         return 4;
  47                 case SPEED_1000:
  48                         return 5;
  49                 case SPEED_100:
  50                         return 19;
  51                 case SPEED_10:
  52                         return 100;
  53                 case SPEED_UNKNOWN:
  54                         return 100;
  55                 default:
  56                         if (ecmd.base.speed > SPEED_10000)
  57                                 return 1;
  58                 }
  59         }
  60
  61         /* Old silly heuristics based on name */
  62         if (!strncmp(dev->name, "lec", 3))
  63                 return 7;
  64
  65         if (!strncmp(dev->name, "plip", 4))
  66                 return 2500;
  67
  68         return 100;     /* assume old 10Mbps */
  69 }
  70
  71
  72 /* Check for port carrier transitions. */
  73 void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
  74 {
  75         struct net_device *dev = p->dev;
  76         struct net_bridge *br = p->br;
  77
  78         if (!(p->flags & BR_ADMIN_COST) &&
  79             netif_running(dev) && netif_oper_up(dev))
  80                 p->path_cost = port_cost(dev);
  81
  82         *notified = false;
  83         if (!netif_running(br->dev))
  84                 return;
  85
  86         spin_lock_bh(&br->lock);
  87         if (netif_running(dev) && netif_oper_up(dev)) {
  88                 if (p->state == BR_STATE_DISABLED) {
  89                         br_stp_enable_port(p);
  90                         *notified = true;
  91                 }
  92         } else {
  93                 if (p->state != BR_STATE_DISABLED) {
  94                         br_stp_disable_port(p);
  95                         *notified = true;
  96                 }
  97         }
  98         spin_unlock_bh(&br->lock);
  99 }
 100
 101 static void br_port_set_promisc(struct net_bridge_port *p)
 102 {
 103         int err = 0;
 104
 105         if (br_promisc_port(p))
 106                 return;
 107
 108         err = dev_set_promiscuity(p->dev, 1);
 109         if (err)
 110                 return;
 111
 112         br_fdb_unsync_static(p->br, p);
 113         p->flags |= BR_PROMISC;
 114 }
 115
 116 static void br_port_clear_promisc(struct net_bridge_port *p)
 117 {
 118         int err;
 119
 120         /* Check if the port is already non-promisc or if it doesn't
 121          * support UNICAST filtering.  Without unicast filtering support
 122          * we'll end up re-enabling promisc mode anyway, so just check for
 123          * it here.
 124          */
 125         if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
 126                 return;
 127
 128         /* Since we'll be clearing the promisc mode, program the port
 129          * first so that we don't have interruption in traffic.
 130          */
 131         err = br_fdb_sync_static(p->br, p);
 132         if (err)
 133                 return;
 134
 135         dev_set_promiscuity(p->dev, -1);
 136         p->flags &= ~BR_PROMISC;
 137 }
 138
 139 /* When a port is added or removed or when certain port flags
 140  * change, this function is called to automatically manage
 141  * promiscuity setting of all the bridge ports.  We are always called
 142  * under RTNL so can skip using rcu primitives.
 143  */
 144 void br_manage_promisc(struct net_bridge *br)
 145 {
 146         struct net_bridge_port *p;
 147         bool set_all = false;
 148
 149         /* If vlan filtering is disabled or bridge interface is placed
 150          * into promiscuous mode, place all ports in promiscuous mode.
 151          */
 152         if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
 153                 set_all = true;
 154
 155         list_for_each_entry(p, &br->port_list, list) {
 156                 if (set_all) {
 157                         br_port_set_promisc(p);
 158                 } else {
 159                         /* If the number of auto-ports is <= 1, then all other
 160                          * ports will have their output configuration
 161                          * statically specified through fdbs.  Since ingress
 162                          * on the auto-port becomes forwarding/egress to other
 163                          * ports and egress configuration is statically known,
 164                          * we can say that ingress configuration of the
 165                          * auto-port is also statically known.
 166                          * This lets us disable promiscuous mode and write
 167                          * this config to hw.
 168                          */
 169                         if ((p->dev->priv_flags & IFF_UNICAST_FLT) &&
 170                             (br->auto_cnt == 0 ||
 171                              (br->auto_cnt == 1 && br_auto_port(p))))
 172                                 br_port_clear_promisc(p);
 173                         else
 174                                 br_port_set_promisc(p);
 175                 }
 176         }
 177 }
 178
 179 int nbp_backup_change(struct net_bridge_port *p,
 180                       struct net_device *backup_dev)
 181 {
 182         struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
 183         struct net_bridge_port *backup_p = NULL;
 184
 185         ASSERT_RTNL();
 186
 187         if (backup_dev) {
 188                 if (!netif_is_bridge_port(backup_dev))
 189                         return -ENOENT;
 190
 191                 backup_p = br_port_get_rtnl(backup_dev);
 192                 if (backup_p->br != p->br)
 193                         return -EINVAL;
 194         }
 195
 196         if (p == backup_p)
 197                 return -EINVAL;
 198
 199         if (old_backup == backup_p)
 200                 return 0;
 201
 202         /* if the backup link is already set, clear it */
 203         if (old_backup)
 204                 old_backup->backup_redirected_cnt--;
 205
 206         if (backup_p)
 207                 backup_p->backup_redirected_cnt++;
 208         rcu_assign_pointer(p->backup_port, backup_p);
 209
 210         return 0;
 211 }
 212
 213 static void nbp_backup_clear(struct net_bridge_port *p)
 214 {
 215         nbp_backup_change(p, NULL);
 216         if (p->backup_redirected_cnt) {
 217                 struct net_bridge_port *cur_p;
 218
 219                 list_for_each_entry(cur_p, &p->br->port_list, list) {
 220                         struct net_bridge_port *backup_p;
 221
 222                         backup_p = rtnl_dereference(cur_p->backup_port);
 223                         if (backup_p == p)
 224                                 nbp_backup_change(cur_p, NULL);
 225                 }
 226         }
 227
 228         WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
 229 }
 230
 231 static void nbp_update_port_count(struct net_bridge *br)
 232 {
 233         struct net_bridge_port *p;
 234         u32 cnt = 0;
 235
 236         list_for_each_entry(p, &br->port_list, list) {
 237                 if (br_auto_port(p))
 238                         cnt++;
 239         }
 240         if (br->auto_cnt != cnt) {
 241                 br->auto_cnt = cnt;
 242                 br_manage_promisc(br);
 243         }
 244 }
 245
 246 static void nbp_delete_promisc(struct net_bridge_port *p)
 247 {
 248         /* If port is currently promiscuous, unset promiscuity.
 249          * Otherwise, it is a static port so remove all addresses
 250          * from it.
 251          */
 252         dev_set_allmulti(p->dev, -1);
 253         if (br_promisc_port(p))
 254                 dev_set_promiscuity(p->dev, -1);
 255         else
 256                 br_fdb_unsync_static(p->br, p);
 257 }
 258
 259 static void release_nbp(struct kobject *kobj)
 260 {
 261         struct net_bridge_port *p
 262                 = container_of(kobj, struct net_bridge_port, kobj);
 263         kfree(p);
 264 }
 265
 266 static void brport_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 267 {
 268         struct net_bridge_port *p = kobj_to_brport(kobj);
 269
 270         net_ns_get_ownership(dev_net(p->dev), uid, gid);
 271 }
 272
 273 static const struct kobj_type brport_ktype = {
 274 #ifdef CONFIG_SYSFS
 275         .sysfs_ops = &brport_sysfs_ops,
 276 #endif
 277         .release = release_nbp,
 278         .get_ownership = brport_get_ownership,
 279 };
 280
 281 static void destroy_nbp(struct net_bridge_port *p)
 282 {
 283         struct net_device *dev = p->dev;
 284
 285         p->br = NULL;
 286         p->dev = NULL;
 287         netdev_put(dev, &p->dev_tracker);
 288
 289         kobject_put(&p->kobj);
 290 }
 291
 292 static void destroy_nbp_rcu(struct rcu_head *head)
 293 {
 294         struct net_bridge_port *p =
 295                         container_of(head, struct net_bridge_port, rcu);
 296         destroy_nbp(p);
 297 }
 298
 299 static unsigned get_max_headroom(struct net_bridge *br)
 300 {
 301         unsigned max_headroom = 0;
 302         struct net_bridge_port *p;
 303
 304         list_for_each_entry(p, &br->port_list, list) {
 305                 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
 306
 307                 if (dev_headroom > max_headroom)
 308                         max_headroom = dev_headroom;
 309         }
 310
 311         return max_headroom;
 312 }
 313
 314 static void update_headroom(struct net_bridge *br, int new_hr)
 315 {
 316         struct net_bridge_port *p;
 317
 318         list_for_each_entry(p, &br->port_list, list)
 319                 netdev_set_rx_headroom(p->dev, new_hr);
 320
 321         br->dev->needed_headroom = new_hr;
 322 }
 323
 324 /* Delete port(interface) from bridge is done in two steps.
 325  * via RCU. First step, marks device as down. That deletes
 326  * all the timers and stops new packets from flowing through.
 327  *
 328  * Final cleanup doesn't occur until after all CPU's finished
 329  * processing packets.
 330  *
 331  * Protected from multiple admin operations by RTNL mutex
 332  */
 333 static void del_nbp(struct net_bridge_port *p)
 334 {
 335         struct net_bridge *br = p->br;
 336         struct net_device *dev = p->dev;
 337
 338         sysfs_remove_link(br->ifobj, p->dev->name);
 339
 340         nbp_delete_promisc(p);
 341
 342         spin_lock_bh(&br->lock);
 343         br_stp_disable_port(p);
 344         spin_unlock_bh(&br->lock);
 345
 346         br_mrp_port_del(br, p);
 347         br_cfm_port_del(br, p);
 348
 349         br_ifinfo_notify(RTM_DELLINK, NULL, p);
 350
 351         list_del_rcu(&p->list);
 352         if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
 353                 update_headroom(br, get_max_headroom(br));
 354         netdev_reset_rx_headroom(dev);
 355
 356         nbp_vlan_flush(p);
 357         br_fdb_delete_by_port(br, p, 0, 1);
 358         switchdev_deferred_process();
 359         nbp_backup_clear(p);
 360
 361         nbp_update_port_count(br);
 362
 363         netdev_upper_dev_unlink(dev, br->dev);
 364
 365         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 366
 367         netdev_rx_handler_unregister(dev);
 368
 369         br_multicast_del_port(p);
 370
 371         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 372         kobject_del(&p->kobj);
 373
 374         br_netpoll_disable(p);
 375
 376         call_rcu(&p->rcu, destroy_nbp_rcu);
 377 }
 378
 379 /* Delete bridge device */
 380 void br_dev_delete(struct net_device *dev, struct list_head *head)
 381 {
 382         struct net_bridge *br = netdev_priv(dev);
 383         struct net_bridge_port *p, *n;
 384
 385         list_for_each_entry_safe(p, n, &br->port_list, list) {
 386                 del_nbp(p);
 387         }
 388
 389         br_recalculate_neigh_suppress_enabled(br);
 390
 391         br_fdb_delete_by_port(br, NULL, 0, 1);
 392
 393         cancel_delayed_work_sync(&br->gc_work);
 394
 395         br_sysfs_delbr(br->dev);
 396         unregister_netdevice_queue(br->dev, head);
 397 }
 398
 399 /* find an available port number */
 400 static int find_portno(struct net_bridge *br)
 401 {
 402         int index;
 403         struct net_bridge_port *p;
 404         unsigned long *inuse;
 405
 406         inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
 407         if (!inuse)
 408                 return -ENOMEM;
 409
 410         __set_bit(0, inuse);    /* zero is reserved */
 411         list_for_each_entry(p, &br->port_list, list)
 412                 __set_bit(p->port_no, inuse);
 413
 414         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 415         bitmap_free(inuse);
 416
 417         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 418 }
 419
 420 /* called with RTNL but without bridge lock */
 421 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 422                                        struct net_device *dev)
 423 {
 424         struct net_bridge_port *p;
 425         int index, err;
 426
 427         index = find_portno(br);
 428         if (index < 0)
 429                 return ERR_PTR(index);
 430
 431         p = kzalloc(sizeof(*p), GFP_KERNEL);
 432         if (p == NULL)
 433                 return ERR_PTR(-ENOMEM);
 434
 435         p->br = br;
 436         netdev_hold(dev, &p->dev_tracker, GFP_KERNEL);
 437         p->dev = dev;
 438         p->path_cost = port_cost(dev);
 439         p->priority = 0x8000 >> BR_PORT_BITS;
 440         p->port_no = index;
 441         p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
 442         br_init_port(p);
 443         br_set_state(p, BR_STATE_DISABLED);
 444         br_stp_port_timer_init(p);
 445         err = br_multicast_add_port(p);
 446         if (err) {
 447                 netdev_put(dev, &p->dev_tracker);
 448                 kfree(p);
 449                 p = ERR_PTR(err);
 450         }
 451
 452         return p;
 453 }
 454
 455 int br_add_bridge(struct net *net, const char *name)
 456 {
 457         struct net_device *dev;
 458         int res;
 459
 460         dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
 461                            br_dev_setup);
 462
 463         if (!dev)
 464                 return -ENOMEM;
 465
 466         dev_net_set(dev, net);
 467         dev->rtnl_link_ops = &br_link_ops;
 468
 469         res = register_netdevice(dev);
 470         if (res)
 471                 free_netdev(dev);
 472         return res;
 473 }
 474
 475 int br_del_bridge(struct net *net, const char *name)
 476 {
 477         struct net_device *dev;
 478         int ret = 0;
 479
 480         dev = __dev_get_by_name(net, name);
 481         if (dev == NULL)
 482                 ret =  -ENXIO;  /* Could not find device */
 483
 484         else if (!netif_is_bridge_master(dev)) {
 485                 /* Attempt to delete non bridge device! */
 486                 ret = -EPERM;
 487         }
 488
 489         else if (dev->flags & IFF_UP) {
 490                 /* Not shutdown yet. */
 491                 ret = -EBUSY;
 492         }
 493
 494         else
 495                 br_dev_delete(dev, NULL);
 496
 497         return ret;
 498 }
 499
 500 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 501 static int br_mtu_min(const struct net_bridge *br)
 502 {
 503         const struct net_bridge_port *p;
 504         int ret_mtu = 0;
 505
 506         list_for_each_entry(p, &br->port_list, list)
 507                 if (!ret_mtu || ret_mtu > p->dev->mtu)
 508                         ret_mtu = p->dev->mtu;
 509
 510         return ret_mtu ? ret_mtu : ETH_DATA_LEN;
 511 }
 512
 513 void br_mtu_auto_adjust(struct net_bridge *br)
 514 {
 515         ASSERT_RTNL();
 516
 517         /* if the bridge MTU was manually configured don't mess with it */
 518         if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
 519                 return;
 520
 521         /* change to the minimum MTU and clear the flag which was set by
 522          * the bridge ndo_change_mtu callback
 523          */
 524         dev_set_mtu(br->dev, br_mtu_min(br));
 525         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
 526 }
 527
 528 static void br_set_gso_limits(struct net_bridge *br)
 529 {
 530         unsigned int tso_max_size = TSO_MAX_SIZE;
 531         const struct net_bridge_port *p;
 532         u16 tso_max_segs = TSO_MAX_SEGS;
 533
 534         list_for_each_entry(p, &br->port_list, list) {
 535                 tso_max_size = min(tso_max_size, p->dev->tso_max_size);
 536                 tso_max_segs = min(tso_max_segs, p->dev->tso_max_segs);
 537         }
 538         netif_set_tso_max_size(br->dev, tso_max_size);
 539         netif_set_tso_max_segs(br->dev, tso_max_segs);
 540 }
 541
 542 /*
 543  * Recomputes features using slave's features
 544  */
 545 netdev_features_t br_features_recompute(struct net_bridge *br,
 546         netdev_features_t features)
 547 {
 548         struct net_bridge_port *p;
 549         netdev_features_t mask;
 550
 551         if (list_empty(&br->port_list))
 552                 return features;
 553
 554         mask = features;
 555         features &= ~NETIF_F_ONE_FOR_ALL;
 556
 557         list_for_each_entry(p, &br->port_list, list) {
 558                 features = netdev_increment_features(features,
 559                                                      p->dev->features, mask);
 560         }
 561         features = netdev_add_tso_features(features, mask);
 562
 563         return features;
 564 }
 565
 566 /* called with RTNL */
 567 int br_add_if(struct net_bridge *br, struct net_device *dev,
 568               struct netlink_ext_ack *extack)
 569 {
 570         struct net_bridge_port *p;
 571         int err = 0;
 572         unsigned br_hr, dev_hr;
 573         bool changed_addr, fdb_synced = false;
 574
 575         /* Don't allow bridging non-ethernet like devices. */
 576         if ((dev->flags & IFF_LOOPBACK) ||
 577             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
 578             !is_valid_ether_addr(dev->dev_addr))
 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                 netdev_put(dev, &p->dev_tracker);
 609                 kfree(p);       /* kobject not yet init'd, manually free */
 610                 goto err1;
 611         }
 612
 613         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 614                                    SYSFS_BRIDGE_PORT_ATTR);
 615         if (err)
 616                 goto err2;
 617
 618         err = br_sysfs_addif(p);
 619         if (err)
 620                 goto err2;
 621
 622         err = br_netpoll_enable(p);
 623         if (err)
 624                 goto err3;
 625
 626         err = netdev_rx_handler_register(dev, br_get_rx_handler(dev), p);
 627         if (err)
 628                 goto err4;
 629
 630         dev->priv_flags |= IFF_BRIDGE_PORT;
 631
 632         err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
 633         if (err)
 634                 goto err5;
 635
 636         dev_disable_lro(dev);
 637
 638         list_add_rcu(&p->list, &br->port_list);
 639
 640         nbp_update_port_count(br);
 641         if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) {
 642                 /* When updating the port count we also update all ports'
 643                  * promiscuous mode.
 644                  * A port leaving promiscuous mode normally gets the bridge's
 645                  * fdb synced to the unicast filter (if supported), however,
 646                  * `br_port_clear_promisc` does not distinguish between
 647                  * non-promiscuous ports and *new* ports, so we need to
 648                  * sync explicitly here.
 649                  */
 650                 fdb_synced = br_fdb_sync_static(br, p) == 0;
 651                 if (!fdb_synced)
 652                         netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n");
 653         }
 654
 655         netdev_update_features(br->dev);
 656
 657         br_hr = br->dev->needed_headroom;
 658         dev_hr = netdev_get_fwd_headroom(dev);
 659         if (br_hr < dev_hr)
 660                 update_headroom(br, dev_hr);
 661         else
 662                 netdev_set_rx_headroom(dev, br_hr);
 663
 664         if (br_fdb_add_local(br, p, dev->dev_addr, 0))
 665                 netdev_err(dev, "failed insert local address bridge forwarding table\n");
 666
 667         if (br->dev->addr_assign_type != NET_ADDR_SET) {
 668                 /* Ask for permission to use this MAC address now, even if we
 669                  * don't end up choosing it below.
 670                  */
 671                 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
 672                 if (err)
 673                         goto err6;
 674         }
 675
 676         err = nbp_vlan_init(p, extack);
 677         if (err) {
 678                 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
 679                 goto err6;
 680         }
 681
 682         spin_lock_bh(&br->lock);
 683         changed_addr = br_stp_recalculate_bridge_id(br);
 684
 685         if (netif_running(dev) && netif_oper_up(dev) &&
 686             (br->dev->flags & IFF_UP))
 687                 br_stp_enable_port(p);
 688         spin_unlock_bh(&br->lock);
 689
 690         br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 691
 692         if (changed_addr)
 693                 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
 694
 695         br_mtu_auto_adjust(br);
 696         br_set_gso_limits(br);
 697
 698         kobject_uevent(&p->kobj, KOBJ_ADD);
 699
 700         return 0;
 701
 702 err6:
 703         if (fdb_synced)
 704                 br_fdb_unsync_static(br, p);
 705         list_del_rcu(&p->list);
 706         br_fdb_delete_by_port(br, p, 0, 1);
 707         nbp_update_port_count(br);
 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         netdev_put(dev, &p->dev_tracker);
 719         kobject_put(&p->kobj);
 720         dev_set_allmulti(dev, -1);
 721 err1:
 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 | BR_NEIGH_VLAN_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);