net/bridge/br_mdb.c

   1 #include <linux/err.h>
   2 #include <linux/igmp.h>
   3 #include <linux/kernel.h>
   4 #include <linux/netdevice.h>
   5 #include <linux/rculist.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/if_ether.h>
   8 #include <net/ip.h>
   9 #include <net/netlink.h>
  10 #include <net/switchdev.h>
  11 #if IS_ENABLED(CONFIG_IPV6)
  12 #include <net/ipv6.h>
  13 #include <net/addrconf.h>
  14 #endif
  15
  16 #include "br_private.h"
  17
  18 static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  19                                struct net_device *dev)
  20 {
  21         struct net_bridge *br = netdev_priv(dev);
  22         struct net_bridge_port *p;
  23         struct nlattr *nest;
  24
  25         if (!br->multicast_router || hlist_empty(&br->router_list))
  26                 return 0;
  27
  28         nest = nla_nest_start(skb, MDBA_ROUTER);
  29         if (nest == NULL)
  30                 return -EMSGSIZE;
  31
  32         hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
  33                 if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
  34                         goto fail;
  35         }
  36
  37         nla_nest_end(skb, nest);
  38         return 0;
  39 fail:
  40         nla_nest_cancel(skb, nest);
  41         return -EMSGSIZE;
  42 }
  43
  44 static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  45                             struct net_device *dev)
  46 {
  47         struct net_bridge *br = netdev_priv(dev);
  48         struct net_bridge_mdb_htable *mdb;
  49         struct nlattr *nest, *nest2;
  50         int i, err = 0;
  51         int idx = 0, s_idx = cb->args[1];
  52
  53         if (br->multicast_disabled)
  54                 return 0;
  55
  56         mdb = rcu_dereference(br->mdb);
  57         if (!mdb)
  58                 return 0;
  59
  60         nest = nla_nest_start(skb, MDBA_MDB);
  61         if (nest == NULL)
  62                 return -EMSGSIZE;
  63
  64         for (i = 0; i < mdb->max; i++) {
  65                 struct net_bridge_mdb_entry *mp;
  66                 struct net_bridge_port_group *p;
  67                 struct net_bridge_port_group __rcu **pp;
  68                 struct net_bridge_port *port;
  69
  70                 hlist_for_each_entry_rcu(mp, &mdb->mhash[i], hlist[mdb->ver]) {
  71                         if (idx < s_idx)
  72                                 goto skip;
  73
  74                         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
  75                         if (nest2 == NULL) {
  76                                 err = -EMSGSIZE;
  77                                 goto out;
  78                         }
  79
  80                         for (pp = &mp->ports;
  81                              (p = rcu_dereference(*pp)) != NULL;
  82                               pp = &p->next) {
  83                                 port = p->port;
  84                                 if (port) {
  85                                         struct br_mdb_entry e;
  86                                         memset(&e, 0, sizeof(e));
  87                                         e.ifindex = port->dev->ifindex;
  88                                         e.state = p->state;
  89                                         e.vid = p->addr.vid;
  90                                         if (p->addr.proto == htons(ETH_P_IP))
  91                                                 e.addr.u.ip4 = p->addr.u.ip4;
  92 #if IS_ENABLED(CONFIG_IPV6)
  93                                         if (p->addr.proto == htons(ETH_P_IPV6))
  94                                                 e.addr.u.ip6 = p->addr.u.ip6;
  95 #endif
  96                                         e.addr.proto = p->addr.proto;
  97                                         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
  98                                                 nla_nest_cancel(skb, nest2);
  99                                                 err = -EMSGSIZE;
 100                                                 goto out;
 101                                         }
 102                                 }
 103                         }
 104                         nla_nest_end(skb, nest2);
 105                 skip:
 106                         idx++;
 107                 }
 108         }
 109
 110 out:
 111         cb->args[1] = idx;
 112         nla_nest_end(skb, nest);
 113         return err;
 114 }
 115
 116 static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 117 {
 118         struct net_device *dev;
 119         struct net *net = sock_net(skb->sk);
 120         struct nlmsghdr *nlh = NULL;
 121         int idx = 0, s_idx;
 122
 123         s_idx = cb->args[0];
 124
 125         rcu_read_lock();
 126
 127         /* In theory this could be wrapped to 0... */
 128         cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
 129
 130         for_each_netdev_rcu(net, dev) {
 131                 if (dev->priv_flags & IFF_EBRIDGE) {
 132                         struct br_port_msg *bpm;
 133
 134                         if (idx < s_idx)
 135                                 goto skip;
 136
 137                         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 138                                         cb->nlh->nlmsg_seq, RTM_GETMDB,
 139                                         sizeof(*bpm), NLM_F_MULTI);
 140                         if (nlh == NULL)
 141                                 break;
 142
 143                         bpm = nlmsg_data(nlh);
 144                         memset(bpm, 0, sizeof(*bpm));
 145                         bpm->ifindex = dev->ifindex;
 146                         if (br_mdb_fill_info(skb, cb, dev) < 0)
 147                                 goto out;
 148                         if (br_rports_fill_info(skb, cb, dev) < 0)
 149                                 goto out;
 150
 151                         cb->args[1] = 0;
 152                         nlmsg_end(skb, nlh);
 153                 skip:
 154                         idx++;
 155                 }
 156         }
 157
 158 out:
 159         if (nlh)
 160                 nlmsg_end(skb, nlh);
 161         rcu_read_unlock();
 162         cb->args[0] = idx;
 163         return skb->len;
 164 }
 165
 166 static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
 167                                    struct net_device *dev,
 168                                    struct br_mdb_entry *entry, u32 pid,
 169                                    u32 seq, int type, unsigned int flags)
 170 {
 171         struct nlmsghdr *nlh;
 172         struct br_port_msg *bpm;
 173         struct nlattr *nest, *nest2;
 174
 175         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), 0);
 176         if (!nlh)
 177                 return -EMSGSIZE;
 178
 179         bpm = nlmsg_data(nlh);
 180         memset(bpm, 0, sizeof(*bpm));
 181         bpm->family  = AF_BRIDGE;
 182         bpm->ifindex = dev->ifindex;
 183         nest = nla_nest_start(skb, MDBA_MDB);
 184         if (nest == NULL)
 185                 goto cancel;
 186         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
 187         if (nest2 == NULL)
 188                 goto end;
 189
 190         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
 191                 goto end;
 192
 193         nla_nest_end(skb, nest2);
 194         nla_nest_end(skb, nest);
 195         nlmsg_end(skb, nlh);
 196         return 0;
 197
 198 end:
 199         nla_nest_end(skb, nest);
 200 cancel:
 201         nlmsg_cancel(skb, nlh);
 202         return -EMSGSIZE;
 203 }
 204
 205 static inline size_t rtnl_mdb_nlmsg_size(void)
 206 {
 207         return NLMSG_ALIGN(sizeof(struct br_port_msg))
 208                 + nla_total_size(sizeof(struct br_mdb_entry));
 209 }
 210
 211 static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
 212                             int type)
 213 {
 214         struct switchdev_obj_port_mdb mdb = {
 215                 .obj = {
 216                         .id = SWITCHDEV_OBJ_ID_PORT_MDB,
 217                         .flags = SWITCHDEV_F_DEFER,
 218                 },
 219                 .vid = entry->vid,
 220         };
 221         struct net_device *port_dev;
 222         struct net *net = dev_net(dev);
 223         struct sk_buff *skb;
 224         int err = -ENOBUFS;
 225
 226         port_dev = __dev_get_by_index(net, entry->ifindex);
 227         if (entry->addr.proto == htons(ETH_P_IP))
 228                 ip_eth_mc_map(entry->addr.u.ip4, mdb.addr);
 229 #if IS_ENABLED(CONFIG_IPV6)
 230         else
 231                 ipv6_eth_mc_map(&entry->addr.u.ip6, mdb.addr);
 232 #endif
 233
 234         mdb.obj.orig_dev = port_dev;
 235         if (port_dev && type == RTM_NEWMDB)
 236                 switchdev_port_obj_add(port_dev, &mdb.obj);
 237         else if (port_dev && type == RTM_DELMDB)
 238                 switchdev_port_obj_del(port_dev, &mdb.obj);
 239
 240         skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
 241         if (!skb)
 242                 goto errout;
 243
 244         err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
 245         if (err < 0) {
 246                 kfree_skb(skb);
 247                 goto errout;
 248         }
 249
 250         rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
 251         return;
 252 errout:
 253         rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 254 }
 255
 256 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 257                    struct br_ip *group, int type, u8 state)
 258 {
 259         struct br_mdb_entry entry;
 260
 261         memset(&entry, 0, sizeof(entry));
 262         entry.ifindex = port->dev->ifindex;
 263         entry.addr.proto = group->proto;
 264         entry.addr.u.ip4 = group->u.ip4;
 265 #if IS_ENABLED(CONFIG_IPV6)
 266         entry.addr.u.ip6 = group->u.ip6;
 267 #endif
 268         entry.state = state;
 269         entry.vid = group->vid;
 270         __br_mdb_notify(dev, &entry, type);
 271 }
 272
 273 static int nlmsg_populate_rtr_fill(struct sk_buff *skb,
 274                                    struct net_device *dev,
 275                                    int ifindex, u32 pid,
 276                                    u32 seq, int type, unsigned int flags)
 277 {
 278         struct br_port_msg *bpm;
 279         struct nlmsghdr *nlh;
 280         struct nlattr *nest;
 281
 282         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
 283         if (!nlh)
 284                 return -EMSGSIZE;
 285
 286         bpm = nlmsg_data(nlh);
 287         memset(bpm, 0, sizeof(*bpm));
 288         bpm->family = AF_BRIDGE;
 289         bpm->ifindex = dev->ifindex;
 290         nest = nla_nest_start(skb, MDBA_ROUTER);
 291         if (!nest)
 292                 goto cancel;
 293
 294         if (nla_put_u32(skb, MDBA_ROUTER_PORT, ifindex))
 295                 goto end;
 296
 297         nla_nest_end(skb, nest);
 298         nlmsg_end(skb, nlh);
 299         return 0;
 300
 301 end:
 302         nla_nest_end(skb, nest);
 303 cancel:
 304         nlmsg_cancel(skb, nlh);
 305         return -EMSGSIZE;
 306 }
 307
 308 static inline size_t rtnl_rtr_nlmsg_size(void)
 309 {
 310         return NLMSG_ALIGN(sizeof(struct br_port_msg))
 311                 + nla_total_size(sizeof(__u32));
 312 }
 313
 314 void br_rtr_notify(struct net_device *dev, struct net_bridge_port *port,
 315                    int type)
 316 {
 317         struct net *net = dev_net(dev);
 318         struct sk_buff *skb;
 319         int err = -ENOBUFS;
 320         int ifindex;
 321
 322         ifindex = port ? port->dev->ifindex : 0;
 323         skb = nlmsg_new(rtnl_rtr_nlmsg_size(), GFP_ATOMIC);
 324         if (!skb)
 325                 goto errout;
 326
 327         err = nlmsg_populate_rtr_fill(skb, dev, ifindex, 0, 0, type, NTF_SELF);
 328         if (err < 0) {
 329                 kfree_skb(skb);
 330                 goto errout;
 331         }
 332
 333         rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
 334         return;
 335
 336 errout:
 337         rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 338 }
 339
 340 static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 341 {
 342         if (entry->ifindex == 0)
 343                 return false;
 344
 345         if (entry->addr.proto == htons(ETH_P_IP)) {
 346                 if (!ipv4_is_multicast(entry->addr.u.ip4))
 347                         return false;
 348                 if (ipv4_is_local_multicast(entry->addr.u.ip4))
 349                         return false;
 350 #if IS_ENABLED(CONFIG_IPV6)
 351         } else if (entry->addr.proto == htons(ETH_P_IPV6)) {
 352                 if (ipv6_addr_is_ll_all_nodes(&entry->addr.u.ip6))
 353                         return false;
 354 #endif
 355         } else
 356                 return false;
 357         if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
 358                 return false;
 359         if (entry->vid >= VLAN_VID_MASK)
 360                 return false;
 361
 362         return true;
 363 }
 364
 365 static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 366                         struct net_device **pdev, struct br_mdb_entry **pentry)
 367 {
 368         struct net *net = sock_net(skb->sk);
 369         struct br_mdb_entry *entry;
 370         struct br_port_msg *bpm;
 371         struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
 372         struct net_device *dev;
 373         int err;
 374
 375         err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY_MAX, NULL);
 376         if (err < 0)
 377                 return err;
 378
 379         bpm = nlmsg_data(nlh);
 380         if (bpm->ifindex == 0) {
 381                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
 382                 return -EINVAL;
 383         }
 384
 385         dev = __dev_get_by_index(net, bpm->ifindex);
 386         if (dev == NULL) {
 387                 pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
 388                 return -ENODEV;
 389         }
 390
 391         if (!(dev->priv_flags & IFF_EBRIDGE)) {
 392                 pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
 393                 return -EOPNOTSUPP;
 394         }
 395
 396         *pdev = dev;
 397
 398         if (!tb[MDBA_SET_ENTRY] ||
 399             nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
 400                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
 401                 return -EINVAL;
 402         }
 403
 404         entry = nla_data(tb[MDBA_SET_ENTRY]);
 405         if (!is_valid_mdb_entry(entry)) {
 406                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
 407                 return -EINVAL;
 408         }
 409
 410         *pentry = entry;
 411         return 0;
 412 }
 413
 414 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 415                             struct br_ip *group, unsigned char state)
 416 {
 417         struct net_bridge_mdb_entry *mp;
 418         struct net_bridge_port_group *p;
 419         struct net_bridge_port_group __rcu **pp;
 420         struct net_bridge_mdb_htable *mdb;
 421         unsigned long now = jiffies;
 422         int err;
 423
 424         mdb = mlock_dereference(br->mdb, br);
 425         mp = br_mdb_ip_get(mdb, group);
 426         if (!mp) {
 427                 mp = br_multicast_new_group(br, port, group);
 428                 err = PTR_ERR_OR_ZERO(mp);
 429                 if (err)
 430                         return err;
 431         }
 432
 433         for (pp = &mp->ports;
 434              (p = mlock_dereference(*pp, br)) != NULL;
 435              pp = &p->next) {
 436                 if (p->port == port)
 437                         return -EEXIST;
 438                 if ((unsigned long)p->port < (unsigned long)port)
 439                         break;
 440         }
 441
 442         p = br_multicast_new_port_group(port, group, *pp, state);
 443         if (unlikely(!p))
 444                 return -ENOMEM;
 445         rcu_assign_pointer(*pp, p);
 446         if (state == MDB_TEMPORARY)
 447                 mod_timer(&p->timer, now + br->multicast_membership_interval);
 448
 449         return 0;
 450 }
 451
 452 static int __br_mdb_add(struct net *net, struct net_bridge *br,
 453                         struct br_mdb_entry *entry)
 454 {
 455         struct br_ip ip;
 456         struct net_device *dev;
 457         struct net_bridge_port *p;
 458         int ret;
 459
 460         if (!netif_running(br->dev) || br->multicast_disabled)
 461                 return -EINVAL;
 462
 463         dev = __dev_get_by_index(net, entry->ifindex);
 464         if (!dev)
 465                 return -ENODEV;
 466
 467         p = br_port_get_rtnl(dev);
 468         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 469                 return -EINVAL;
 470
 471         memset(&ip, 0, sizeof(ip));
 472         ip.vid = entry->vid;
 473         ip.proto = entry->addr.proto;
 474         if (ip.proto == htons(ETH_P_IP))
 475                 ip.u.ip4 = entry->addr.u.ip4;
 476 #if IS_ENABLED(CONFIG_IPV6)
 477         else
 478                 ip.u.ip6 = entry->addr.u.ip6;
 479 #endif
 480
 481         spin_lock_bh(&br->multicast_lock);
 482         ret = br_mdb_add_group(br, p, &ip, entry->state);
 483         spin_unlock_bh(&br->multicast_lock);
 484         return ret;
 485 }
 486
 487 static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 488 {
 489         struct net *net = sock_net(skb->sk);
 490         struct net_bridge_vlan_group *vg;
 491         struct net_device *dev, *pdev;
 492         struct br_mdb_entry *entry;
 493         struct net_bridge_port *p;
 494         struct net_bridge_vlan *v;
 495         struct net_bridge *br;
 496         int err;
 497
 498         err = br_mdb_parse(skb, nlh, &dev, &entry);
 499         if (err < 0)
 500                 return err;
 501
 502         br = netdev_priv(dev);
 503
 504         /* If vlan filtering is enabled and VLAN is not specified
 505          * install mdb entry on all vlans configured on the port.
 506          */
 507         pdev = __dev_get_by_index(net, entry->ifindex);
 508         if (!pdev)
 509                 return -ENODEV;
 510
 511         p = br_port_get_rtnl(pdev);
 512         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 513                 return -EINVAL;
 514
 515         vg = nbp_vlan_group(p);
 516         if (br_vlan_enabled(br) && vg && entry->vid == 0) {
 517                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 518                         entry->vid = v->vid;
 519                         err = __br_mdb_add(net, br, entry);
 520                         if (err)
 521                                 break;
 522                         __br_mdb_notify(dev, entry, RTM_NEWMDB);
 523                 }
 524         } else {
 525                 err = __br_mdb_add(net, br, entry);
 526                 if (!err)
 527                         __br_mdb_notify(dev, entry, RTM_NEWMDB);
 528         }
 529
 530         return err;
 531 }
 532
 533 static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 534 {
 535         struct net_bridge_mdb_htable *mdb;
 536         struct net_bridge_mdb_entry *mp;
 537         struct net_bridge_port_group *p;
 538         struct net_bridge_port_group __rcu **pp;
 539         struct br_ip ip;
 540         int err = -EINVAL;
 541
 542         if (!netif_running(br->dev) || br->multicast_disabled)
 543                 return -EINVAL;
 544
 545         memset(&ip, 0, sizeof(ip));
 546         ip.vid = entry->vid;
 547         ip.proto = entry->addr.proto;
 548         if (ip.proto == htons(ETH_P_IP))
 549                 ip.u.ip4 = entry->addr.u.ip4;
 550 #if IS_ENABLED(CONFIG_IPV6)
 551         else
 552                 ip.u.ip6 = entry->addr.u.ip6;
 553 #endif
 554
 555         spin_lock_bh(&br->multicast_lock);
 556         mdb = mlock_dereference(br->mdb, br);
 557
 558         mp = br_mdb_ip_get(mdb, &ip);
 559         if (!mp)
 560                 goto unlock;
 561
 562         for (pp = &mp->ports;
 563              (p = mlock_dereference(*pp, br)) != NULL;
 564              pp = &p->next) {
 565                 if (!p->port || p->port->dev->ifindex != entry->ifindex)
 566                         continue;
 567
 568                 if (p->port->state == BR_STATE_DISABLED)
 569                         goto unlock;
 570
 571                 entry->state = p->state;
 572                 rcu_assign_pointer(*pp, p->next);
 573                 hlist_del_init(&p->mglist);
 574                 del_timer(&p->timer);
 575                 call_rcu_bh(&p->rcu, br_multicast_free_pg);
 576                 err = 0;
 577
 578                 if (!mp->ports && !mp->mglist &&
 579                     netif_running(br->dev))
 580                         mod_timer(&mp->timer, jiffies);
 581                 break;
 582         }
 583
 584 unlock:
 585         spin_unlock_bh(&br->multicast_lock);
 586         return err;
 587 }
 588
 589 static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
 590 {
 591         struct net *net = sock_net(skb->sk);
 592         struct net_bridge_vlan_group *vg;
 593         struct net_device *dev, *pdev;
 594         struct br_mdb_entry *entry;
 595         struct net_bridge_port *p;
 596         struct net_bridge_vlan *v;
 597         struct net_bridge *br;
 598         int err;
 599
 600         err = br_mdb_parse(skb, nlh, &dev, &entry);
 601         if (err < 0)
 602                 return err;
 603
 604         br = netdev_priv(dev);
 605
 606         /* If vlan filtering is enabled and VLAN is not specified
 607          * delete mdb entry on all vlans configured on the port.
 608          */
 609         pdev = __dev_get_by_index(net, entry->ifindex);
 610         if (!pdev)
 611                 return -ENODEV;
 612
 613         p = br_port_get_rtnl(pdev);
 614         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 615                 return -EINVAL;
 616
 617         vg = nbp_vlan_group(p);
 618         if (br_vlan_enabled(br) && vg && entry->vid == 0) {
 619                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 620                         entry->vid = v->vid;
 621                         err = __br_mdb_del(br, entry);
 622                         if (!err)
 623                                 __br_mdb_notify(dev, entry, RTM_DELMDB);
 624                 }
 625         } else {
 626                 err = __br_mdb_del(br, entry);
 627                 if (!err)
 628                         __br_mdb_notify(dev, entry, RTM_DELMDB);
 629         }
 630
 631         return err;
 632 }
 633
 634 void br_mdb_init(void)
 635 {
 636         rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
 637         rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
 638         rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
 639 }
 640
 641 void br_mdb_uninit(void)
 642 {
 643         rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
 644         rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
 645         rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
 646 }