net/bridge/br_netlink.c

   1 /*
   2  *      Bridge netlink control interface
   3  *
   4  *      Authors:
   5  *      Stephen Hemminger               <shemminger@osdl.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/etherdevice.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/net_namespace.h>
  18 #include <net/sock.h>
  19 #include <uapi/linux/if_bridge.h>
  20
  21 #include "br_private.h"
  22 #include "br_private_stp.h"
  23
  24 static inline size_t br_port_info_size(void)
  25 {
  26         return nla_total_size(1)        /* IFLA_BRPORT_STATE  */
  27                 + nla_total_size(2)     /* IFLA_BRPORT_PRIORITY */
  28                 + nla_total_size(4)     /* IFLA_BRPORT_COST */
  29                 + nla_total_size(1)     /* IFLA_BRPORT_MODE */
  30                 + nla_total_size(1)     /* IFLA_BRPORT_GUARD */
  31                 + nla_total_size(1)     /* IFLA_BRPORT_PROTECT */
  32                 + nla_total_size(1)     /* IFLA_BRPORT_FAST_LEAVE */
  33                 + nla_total_size(1)     /* IFLA_BRPORT_LEARNING */
  34                 + nla_total_size(1)     /* IFLA_BRPORT_UNICAST_FLOOD */
  35                 + 0;
  36 }
  37
  38 static inline size_t br_nlmsg_size(void)
  39 {
  40         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  41                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  42                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  43                 + nla_total_size(4) /* IFLA_MASTER */
  44                 + nla_total_size(4) /* IFLA_MTU */
  45                 + nla_total_size(4) /* IFLA_LINK */
  46                 + nla_total_size(1) /* IFLA_OPERSTATE */
  47                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  48 }
  49
  50 static int br_port_fill_attrs(struct sk_buff *skb,
  51                               const struct net_bridge_port *p)
  52 {
  53         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  54
  55         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  56             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  57             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  58             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  59             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  60             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
  61             nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
  62             nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
  63             nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD, !!(p->flags & BR_FLOOD)))
  64                 return -EMSGSIZE;
  65
  66         return 0;
  67 }
  68
  69 /*
  70  * Create one netlink message for one interface
  71  * Contains port and master info as well as carrier and bridge state.
  72  */
  73 static int br_fill_ifinfo(struct sk_buff *skb,
  74                           const struct net_bridge_port *port,
  75                           u32 pid, u32 seq, int event, unsigned int flags,
  76                           u32 filter_mask, const struct net_device *dev)
  77 {
  78         const struct net_bridge *br;
  79         struct ifinfomsg *hdr;
  80         struct nlmsghdr *nlh;
  81         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  82
  83         if (port)
  84                 br = port->br;
  85         else
  86                 br = netdev_priv(dev);
  87
  88         br_debug(br, "br_fill_info event %d port %s master %s\n",
  89                      event, dev->name, br->dev->name);
  90
  91         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  92         if (nlh == NULL)
  93                 return -EMSGSIZE;
  94
  95         hdr = nlmsg_data(nlh);
  96         hdr->ifi_family = AF_BRIDGE;
  97         hdr->__ifi_pad = 0;
  98         hdr->ifi_type = dev->type;
  99         hdr->ifi_index = dev->ifindex;
 100         hdr->ifi_flags = dev_get_flags(dev);
 101         hdr->ifi_change = 0;
 102
 103         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
 104             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
 105             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
 106             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
 107             (dev->addr_len &&
 108              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
 109             (dev->ifindex != dev->iflink &&
 110              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
 111                 goto nla_put_failure;
 112
 113         if (event == RTM_NEWLINK && port) {
 114                 struct nlattr *nest
 115                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 116
 117                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 118                         goto nla_put_failure;
 119                 nla_nest_end(skb, nest);
 120         }
 121
 122         /* Check if  the VID information is requested */
 123         if (filter_mask & RTEXT_FILTER_BRVLAN) {
 124                 struct nlattr *af;
 125                 const struct net_port_vlans *pv;
 126                 struct bridge_vlan_info vinfo;
 127                 u16 vid;
 128                 u16 pvid;
 129
 130                 if (port)
 131                         pv = nbp_get_vlan_info(port);
 132                 else
 133                         pv = br_get_vlan_info(br);
 134
 135                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID))
 136                         goto done;
 137
 138                 af = nla_nest_start(skb, IFLA_AF_SPEC);
 139                 if (!af)
 140                         goto nla_put_failure;
 141
 142                 pvid = br_get_pvid(pv);
 143                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 144                         vinfo.vid = vid;
 145                         vinfo.flags = 0;
 146                         if (vid == pvid)
 147                                 vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 148
 149                         if (test_bit(vid, pv->untagged_bitmap))
 150                                 vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 151
 152                         if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
 153                                     sizeof(vinfo), &vinfo))
 154                                 goto nla_put_failure;
 155                 }
 156
 157                 nla_nest_end(skb, af);
 158         }
 159
 160 done:
 161         return nlmsg_end(skb, nlh);
 162
 163 nla_put_failure:
 164         nlmsg_cancel(skb, nlh);
 165         return -EMSGSIZE;
 166 }
 167
 168 /*
 169  * Notify listeners of a change in port information
 170  */
 171 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 172 {
 173         struct net *net;
 174         struct sk_buff *skb;
 175         int err = -ENOBUFS;
 176
 177         if (!port)
 178                 return;
 179
 180         net = dev_net(port->dev);
 181         br_debug(port->br, "port %u(%s) event %d\n",
 182                  (unsigned int)port->port_no, port->dev->name, event);
 183
 184         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 185         if (skb == NULL)
 186                 goto errout;
 187
 188         err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
 189         if (err < 0) {
 190                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 191                 WARN_ON(err == -EMSGSIZE);
 192                 kfree_skb(skb);
 193                 goto errout;
 194         }
 195         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 196         return;
 197 errout:
 198         rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 199 }
 200
 201
 202 /*
 203  * Dump information about all ports, in response to GETLINK
 204  */
 205 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 206                struct net_device *dev, u32 filter_mask)
 207 {
 208         int err = 0;
 209         struct net_bridge_port *port = br_port_get_rtnl(dev);
 210
 211         if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
 212                 goto out;
 213
 214         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
 215                              filter_mask, dev);
 216 out:
 217         return err;
 218 }
 219
 220 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
 221         [IFLA_BRIDGE_FLAGS]     = { .type = NLA_U16 },
 222         [IFLA_BRIDGE_MODE]      = { .type = NLA_U16 },
 223         [IFLA_BRIDGE_VLAN_INFO] = { .type = NLA_BINARY,
 224                                     .len = sizeof(struct bridge_vlan_info), },
 225 };
 226
 227 static int br_afspec(struct net_bridge *br,
 228                      struct net_bridge_port *p,
 229                      struct nlattr *af_spec,
 230                      int cmd)
 231 {
 232         struct nlattr *tb[IFLA_BRIDGE_MAX+1];
 233         int err = 0;
 234
 235         err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
 236         if (err)
 237                 return err;
 238
 239         if (tb[IFLA_BRIDGE_VLAN_INFO]) {
 240                 struct bridge_vlan_info *vinfo;
 241
 242                 vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
 243
 244                 if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
 245                         return -EINVAL;
 246
 247                 switch (cmd) {
 248                 case RTM_SETLINK:
 249                         if (p) {
 250                                 err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
 251                                 if (err)
 252                                         break;
 253
 254                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 255                                         err = br_vlan_add(p->br, vinfo->vid,
 256                                                           vinfo->flags);
 257                         } else
 258                                 err = br_vlan_add(br, vinfo->vid, vinfo->flags);
 259
 260                         break;
 261
 262                 case RTM_DELLINK:
 263                         if (p) {
 264                                 nbp_vlan_delete(p, vinfo->vid);
 265                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 266                                         br_vlan_delete(p->br, vinfo->vid);
 267                         } else
 268                                 br_vlan_delete(br, vinfo->vid);
 269                         break;
 270                 }
 271         }
 272
 273         return err;
 274 }
 275
 276 static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
 277         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 278         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 279         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 280         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 281         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 282         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 283         [IFLA_BRPORT_LEARNING]  = { .type = NLA_U8 },
 284         [IFLA_BRPORT_UNICAST_FLOOD] = { .type = NLA_U8 },
 285 };
 286
 287 /* Change the state of the port and notify spanning tree */
 288 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 289 {
 290         if (state > BR_STATE_BLOCKING)
 291                 return -EINVAL;
 292
 293         /* if kernel STP is running, don't allow changes */
 294         if (p->br->stp_enabled == BR_KERNEL_STP)
 295                 return -EBUSY;
 296
 297         /* if device is not up, change is not allowed
 298          * if link is not present, only allowable state is disabled
 299          */
 300         if (!netif_running(p->dev) ||
 301             (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
 302                 return -ENETDOWN;
 303
 304         p->state = state;
 305         br_log_state(p);
 306         br_port_state_selection(p->br);
 307         return 0;
 308 }
 309
 310 /* Set/clear or port flags based on attribute */
 311 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 312                            int attrtype, unsigned long mask)
 313 {
 314         if (tb[attrtype]) {
 315                 u8 flag = nla_get_u8(tb[attrtype]);
 316                 if (flag)
 317                         p->flags |= mask;
 318                 else
 319                         p->flags &= ~mask;
 320         }
 321 }
 322
 323 /* Process bridge protocol info on port */
 324 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 325 {
 326         int err;
 327         unsigned long old_flags = p->flags;
 328
 329         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 330         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 331         br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
 332         br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
 333         br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
 334         br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
 335
 336         if (tb[IFLA_BRPORT_COST]) {
 337                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 338                 if (err)
 339                         return err;
 340         }
 341
 342         if (tb[IFLA_BRPORT_PRIORITY]) {
 343                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 344                 if (err)
 345                         return err;
 346         }
 347
 348         if (tb[IFLA_BRPORT_STATE]) {
 349                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 350                 if (err)
 351                         return err;
 352         }
 353
 354         br_port_flags_change(p, old_flags ^ p->flags);
 355         return 0;
 356 }
 357
 358 /* Change state and parameters on port. */
 359 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 360 {
 361         struct nlattr *protinfo;
 362         struct nlattr *afspec;
 363         struct net_bridge_port *p;
 364         struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 365         int err = 0;
 366
 367         protinfo = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_PROTINFO);
 368         afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
 369         if (!protinfo && !afspec)
 370                 return 0;
 371
 372         p = br_port_get_rtnl(dev);
 373         /* We want to accept dev as bridge itself if the AF_SPEC
 374          * is set to see if someone is setting vlan info on the bridge
 375          */
 376         if (!p && !afspec)
 377                 return -EINVAL;
 378
 379         if (p && protinfo) {
 380                 if (protinfo->nla_type & NLA_F_NESTED) {
 381                         err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 382                                                protinfo, br_port_policy);
 383                         if (err)
 384                                 return err;
 385
 386                         spin_lock_bh(&p->br->lock);
 387                         err = br_setport(p, tb);
 388                         spin_unlock_bh(&p->br->lock);
 389                 } else {
 390                         /* Binary compatibility with old RSTP */
 391                         if (nla_len(protinfo) < sizeof(u8))
 392                                 return -EINVAL;
 393
 394                         spin_lock_bh(&p->br->lock);
 395                         err = br_set_port_state(p, nla_get_u8(protinfo));
 396                         spin_unlock_bh(&p->br->lock);
 397                 }
 398                 if (err)
 399                         goto out;
 400         }
 401
 402         if (afspec) {
 403                 err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 404                                 afspec, RTM_SETLINK);
 405         }
 406
 407         if (err == 0)
 408                 br_ifinfo_notify(RTM_NEWLINK, p);
 409
 410 out:
 411         return err;
 412 }
 413
 414 /* Delete port information */
 415 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
 416 {
 417         struct nlattr *afspec;
 418         struct net_bridge_port *p;
 419         int err;
 420
 421         afspec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
 422         if (!afspec)
 423                 return 0;
 424
 425         p = br_port_get_rtnl(dev);
 426         /* We want to accept dev as bridge itself as well */
 427         if (!p && !(dev->priv_flags & IFF_EBRIDGE))
 428                 return -EINVAL;
 429
 430         err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 431                         afspec, RTM_DELLINK);
 432
 433         return err;
 434 }
 435 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 436 {
 437         if (tb[IFLA_ADDRESS]) {
 438                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 439                         return -EINVAL;
 440                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 441                         return -EADDRNOTAVAIL;
 442         }
 443
 444         return 0;
 445 }
 446
 447 static int br_dev_newlink(struct net *src_net, struct net_device *dev,
 448                           struct nlattr *tb[], struct nlattr *data[])
 449 {
 450         struct net_bridge *br = netdev_priv(dev);
 451
 452         if (tb[IFLA_ADDRESS]) {
 453                 spin_lock_bh(&br->lock);
 454                 br_stp_change_bridge_id(br, nla_data(tb[IFLA_ADDRESS]));
 455                 spin_unlock_bh(&br->lock);
 456         }
 457
 458         return register_netdevice(dev);
 459 }
 460
 461 static int br_port_slave_changelink(struct net_device *brdev,
 462                                     struct net_device *dev,
 463                                     struct nlattr *tb[],
 464                                     struct nlattr *data[])
 465 {
 466         if (!data)
 467                 return 0;
 468         return br_setport(br_port_get_rtnl(dev), data);
 469 }
 470
 471 static int br_port_fill_slave_info(struct sk_buff *skb,
 472                                    const struct net_device *brdev,
 473                                    const struct net_device *dev)
 474 {
 475         return br_port_fill_attrs(skb, br_port_get_rtnl(dev));
 476 }
 477
 478 static size_t br_port_get_slave_size(const struct net_device *brdev,
 479                                      const struct net_device *dev)
 480 {
 481         return br_port_info_size();
 482 }
 483
 484 static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = {
 485         [IFLA_BR_FORWARD_DELAY] = { .type = NLA_U32 },
 486         [IFLA_BR_HELLO_TIME]    = { .type = NLA_U32 },
 487         [IFLA_BR_MAX_AGE]       = { .type = NLA_U32 },
 488 };
 489
 490 static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
 491                          struct nlattr *data[])
 492 {
 493         struct net_bridge *br = netdev_priv(brdev);
 494         int err;
 495
 496         if (!data)
 497                 return 0;
 498
 499         if (data[IFLA_BR_FORWARD_DELAY]) {
 500                 err = br_set_forward_delay(br, nla_get_u32(data[IFLA_BR_FORWARD_DELAY]));
 501                 if (err)
 502                         return err;
 503         }
 504
 505         if (data[IFLA_BR_HELLO_TIME]) {
 506                 err = br_set_hello_time(br, nla_get_u32(data[IFLA_BR_HELLO_TIME]));
 507                 if (err)
 508                         return err;
 509         }
 510
 511         if (data[IFLA_BR_MAX_AGE]) {
 512                 err = br_set_max_age(br, nla_get_u32(data[IFLA_BR_MAX_AGE]));
 513                 if (err)
 514                         return err;
 515         }
 516
 517         return 0;
 518 }
 519
 520 static size_t br_get_size(const struct net_device *brdev)
 521 {
 522         return nla_total_size(sizeof(u32)) +    /* IFLA_BR_FORWARD_DELAY  */
 523                nla_total_size(sizeof(u32)) +    /* IFLA_BR_HELLO_TIME */
 524                nla_total_size(sizeof(u32)) +    /* IFLA_BR_MAX_AGE */
 525                0;
 526 }
 527
 528 static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 529 {
 530         struct net_bridge *br = netdev_priv(brdev);
 531         u32 forward_delay = jiffies_to_clock_t(br->forward_delay);
 532         u32 hello_time = jiffies_to_clock_t(br->hello_time);
 533         u32 age_time = jiffies_to_clock_t(br->max_age);
 534
 535         if (nla_put_u32(skb, IFLA_BR_FORWARD_DELAY, forward_delay) ||
 536             nla_put_u32(skb, IFLA_BR_HELLO_TIME, hello_time) ||
 537             nla_put_u32(skb, IFLA_BR_MAX_AGE, age_time))
 538                 return -EMSGSIZE;
 539
 540         return 0;
 541 }
 542
 543 static size_t br_get_link_af_size(const struct net_device *dev)
 544 {
 545         struct net_port_vlans *pv;
 546
 547         if (br_port_exists(dev))
 548                 pv = nbp_get_vlan_info(br_port_get_rtnl(dev));
 549         else if (dev->priv_flags & IFF_EBRIDGE)
 550                 pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
 551         else
 552                 return 0;
 553
 554         if (!pv)
 555                 return 0;
 556
 557         /* Each VLAN is returned in bridge_vlan_info along with flags */
 558         return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
 559 }
 560
 561 static struct rtnl_af_ops br_af_ops = {
 562         .family                 = AF_BRIDGE,
 563         .get_link_af_size       = br_get_link_af_size,
 564 };
 565
 566 struct rtnl_link_ops br_link_ops __read_mostly = {
 567         .kind                   = "bridge",
 568         .priv_size              = sizeof(struct net_bridge),
 569         .setup                  = br_dev_setup,
 570         .maxtype                = IFLA_BRPORT_MAX,
 571         .policy                 = br_policy,
 572         .validate               = br_validate,
 573         .newlink                = br_dev_newlink,
 574         .changelink             = br_changelink,
 575         .dellink                = br_dev_delete,
 576         .get_size               = br_get_size,
 577         .fill_info              = br_fill_info,
 578
 579         .slave_maxtype          = IFLA_BRPORT_MAX,
 580         .slave_policy           = br_port_policy,
 581         .slave_changelink       = br_port_slave_changelink,
 582         .get_slave_size         = br_port_get_slave_size,
 583         .fill_slave_info        = br_port_fill_slave_info,
 584 };
 585
 586 int __init br_netlink_init(void)
 587 {
 588         int err;
 589
 590         br_mdb_init();
 591         rtnl_af_register(&br_af_ops);
 592
 593         err = rtnl_link_register(&br_link_ops);
 594         if (err)
 595                 goto out_af;
 596
 597         return 0;
 598
 599 out_af:
 600         rtnl_af_unregister(&br_af_ops);
 601         br_mdb_uninit();
 602         return err;
 603 }
 604
 605 void __exit br_netlink_fini(void)
 606 {
 607         br_mdb_uninit();
 608         rtnl_af_unregister(&br_af_ops);
 609         rtnl_link_unregister(&br_link_ops);
 610 }