net/bridge/br_fdb.c

   1 /*
   2  *      Forwarding database
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/rculist.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/times.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/jhash.h>
  22 #include <linux/random.h>
  23 #include <linux/slab.h>
  24 #include <linux/atomic.h>
  25 #include <asm/unaligned.h>
  26 #include <linux/if_vlan.h>
  27 #include "br_private.h"
  28
  29 static struct kmem_cache *br_fdb_cache __read_mostly;
  30 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  31                                              const unsigned char *addr,
  32                                              __u16 vid);
  33 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  34                       const unsigned char *addr, u16 vid);
  35 static void fdb_notify(struct net_bridge *br,
  36                        const struct net_bridge_fdb_entry *, int);
  37
  38 static u32 fdb_salt __read_mostly;
  39
  40 int __init br_fdb_init(void)
  41 {
  42         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  43                                          sizeof(struct net_bridge_fdb_entry),
  44                                          0,
  45                                          SLAB_HWCACHE_ALIGN, NULL);
  46         if (!br_fdb_cache)
  47                 return -ENOMEM;
  48
  49         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  50         return 0;
  51 }
  52
  53 void br_fdb_fini(void)
  54 {
  55         kmem_cache_destroy(br_fdb_cache);
  56 }
  57
  58
  59 /* if topology_changing then use forward_delay (default 15 sec)
  60  * otherwise keep longer (default 5 minutes)
  61  */
  62 static inline unsigned long hold_time(const struct net_bridge *br)
  63 {
  64         return br->topology_change ? br->forward_delay : br->ageing_time;
  65 }
  66
  67 static inline int has_expired(const struct net_bridge *br,
  68                                   const struct net_bridge_fdb_entry *fdb)
  69 {
  70         return !fdb->is_static &&
  71                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  72 }
  73
  74 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  75 {
  76         /* use 1 byte of OUI and 3 bytes of NIC */
  77         u32 key = get_unaligned((u32 *)(mac + 2));
  78         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  79 }
  80
  81 static void fdb_rcu_free(struct rcu_head *head)
  82 {
  83         struct net_bridge_fdb_entry *ent
  84                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  85         kmem_cache_free(br_fdb_cache, ent);
  86 }
  87
  88 /* When a static FDB entry is added, the mac address from the entry is
  89  * added to the bridge private HW address list and all required ports
  90  * are then updated with the new information.
  91  * Called under RTNL.
  92  */
  93 static void fdb_add_hw(struct net_bridge *br, const unsigned char *addr)
  94 {
  95         int err;
  96         struct net_bridge_port *p;
  97
  98         ASSERT_RTNL();
  99
 100         list_for_each_entry(p, &br->port_list, list) {
 101                 if (!br_promisc_port(p)) {
 102                         err = dev_uc_add(p->dev, addr);
 103                         if (err)
 104                                 goto undo;
 105                 }
 106         }
 107
 108         return;
 109 undo:
 110         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 111                 if (!br_promisc_port(p))
 112                         dev_uc_del(p->dev, addr);
 113         }
 114 }
 115
 116 /* When a static FDB entry is deleted, the HW address from that entry is
 117  * also removed from the bridge private HW address list and updates all
 118  * the ports with needed information.
 119  * Called under RTNL.
 120  */
 121 static void fdb_del_hw(struct net_bridge *br, const unsigned char *addr)
 122 {
 123         struct net_bridge_port *p;
 124
 125         ASSERT_RTNL();
 126
 127         list_for_each_entry(p, &br->port_list, list) {
 128                 if (!br_promisc_port(p))
 129                         dev_uc_del(p->dev, addr);
 130         }
 131 }
 132
 133 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 134 {
 135         if (f->is_static)
 136                 fdb_del_hw(br, f->addr.addr);
 137
 138         hlist_del_rcu(&f->hlist);
 139         fdb_notify(br, f, RTM_DELNEIGH);
 140         call_rcu(&f->rcu, fdb_rcu_free);
 141 }
 142
 143 /* Delete a local entry if no other port had the same address. */
 144 static void fdb_delete_local(struct net_bridge *br,
 145                              const struct net_bridge_port *p,
 146                              struct net_bridge_fdb_entry *f)
 147 {
 148         const unsigned char *addr = f->addr.addr;
 149         u16 vid = f->vlan_id;
 150         struct net_bridge_port *op;
 151
 152         /* Maybe another port has same hw addr? */
 153         list_for_each_entry(op, &br->port_list, list) {
 154                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 155                     (!vid || nbp_vlan_find(op, vid))) {
 156                         f->dst = op;
 157                         f->added_by_user = 0;
 158                         return;
 159                 }
 160         }
 161
 162         /* Maybe bridge device has same hw addr? */
 163         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 164             (!vid || br_vlan_find(br, vid))) {
 165                 f->dst = NULL;
 166                 f->added_by_user = 0;
 167                 return;
 168         }
 169
 170         fdb_delete(br, f);
 171 }
 172
 173 void br_fdb_find_delete_local(struct net_bridge *br,
 174                               const struct net_bridge_port *p,
 175                               const unsigned char *addr, u16 vid)
 176 {
 177         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 178         struct net_bridge_fdb_entry *f;
 179
 180         spin_lock_bh(&br->hash_lock);
 181         f = fdb_find(head, addr, vid);
 182         if (f && f->is_local && !f->added_by_user && f->dst == p)
 183                 fdb_delete_local(br, p, f);
 184         spin_unlock_bh(&br->hash_lock);
 185 }
 186
 187 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 188 {
 189         struct net_bridge *br = p->br;
 190         struct net_port_vlans *pv = nbp_get_vlan_info(p);
 191         bool no_vlan = !pv;
 192         int i;
 193         u16 vid;
 194
 195         spin_lock_bh(&br->hash_lock);
 196
 197         /* Search all chains since old address/hash is unknown */
 198         for (i = 0; i < BR_HASH_SIZE; i++) {
 199                 struct hlist_node *h;
 200                 hlist_for_each(h, &br->hash[i]) {
 201                         struct net_bridge_fdb_entry *f;
 202
 203                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 204                         if (f->dst == p && f->is_local && !f->added_by_user) {
 205                                 /* delete old one */
 206                                 fdb_delete_local(br, p, f);
 207
 208                                 /* if this port has no vlan information
 209                                  * configured, we can safely be done at
 210                                  * this point.
 211                                  */
 212                                 if (no_vlan)
 213                                         goto insert;
 214                         }
 215                 }
 216         }
 217
 218 insert:
 219         /* insert new address,  may fail if invalid address or dup. */
 220         fdb_insert(br, p, newaddr, 0);
 221
 222         if (no_vlan)
 223                 goto done;
 224
 225         /* Now add entries for every VLAN configured on the port.
 226          * This function runs under RTNL so the bitmap will not change
 227          * from under us.
 228          */
 229         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 230                 fdb_insert(br, p, newaddr, vid);
 231
 232 done:
 233         spin_unlock_bh(&br->hash_lock);
 234 }
 235
 236 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 237 {
 238         struct net_bridge_fdb_entry *f;
 239         struct net_port_vlans *pv;
 240         u16 vid = 0;
 241
 242         spin_lock_bh(&br->hash_lock);
 243
 244         /* If old entry was unassociated with any port, then delete it. */
 245         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 246         if (f && f->is_local && !f->dst)
 247                 fdb_delete_local(br, NULL, f);
 248
 249         fdb_insert(br, NULL, newaddr, 0);
 250
 251         /* Now remove and add entries for every VLAN configured on the
 252          * bridge.  This function runs under RTNL so the bitmap will not
 253          * change from under us.
 254          */
 255         pv = br_get_vlan_info(br);
 256         if (!pv)
 257                 goto out;
 258
 259         for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
 260                 f = __br_fdb_get(br, br->dev->dev_addr, vid);
 261                 if (f && f->is_local && !f->dst)
 262                         fdb_delete_local(br, NULL, f);
 263                 fdb_insert(br, NULL, newaddr, vid);
 264         }
 265 out:
 266         spin_unlock_bh(&br->hash_lock);
 267 }
 268
 269 void br_fdb_cleanup(unsigned long _data)
 270 {
 271         struct net_bridge *br = (struct net_bridge *)_data;
 272         unsigned long delay = hold_time(br);
 273         unsigned long next_timer = jiffies + br->ageing_time;
 274         int i;
 275
 276         spin_lock(&br->hash_lock);
 277         for (i = 0; i < BR_HASH_SIZE; i++) {
 278                 struct net_bridge_fdb_entry *f;
 279                 struct hlist_node *n;
 280
 281                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 282                         unsigned long this_timer;
 283                         if (f->is_static)
 284                                 continue;
 285                         this_timer = f->updated + delay;
 286                         if (time_before_eq(this_timer, jiffies))
 287                                 fdb_delete(br, f);
 288                         else if (time_before(this_timer, next_timer))
 289                                 next_timer = this_timer;
 290                 }
 291         }
 292         spin_unlock(&br->hash_lock);
 293
 294         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 295 }
 296
 297 /* Completely flush all dynamic entries in forwarding database.*/
 298 void br_fdb_flush(struct net_bridge *br)
 299 {
 300         int i;
 301
 302         spin_lock_bh(&br->hash_lock);
 303         for (i = 0; i < BR_HASH_SIZE; i++) {
 304                 struct net_bridge_fdb_entry *f;
 305                 struct hlist_node *n;
 306                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 307                         if (!f->is_static)
 308                                 fdb_delete(br, f);
 309                 }
 310         }
 311         spin_unlock_bh(&br->hash_lock);
 312 }
 313
 314 /* Flush all entries referring to a specific port.
 315  * if do_all is set also flush static entries
 316  */
 317 void br_fdb_delete_by_port(struct net_bridge *br,
 318                            const struct net_bridge_port *p,
 319                            int do_all)
 320 {
 321         int i;
 322
 323         spin_lock_bh(&br->hash_lock);
 324         for (i = 0; i < BR_HASH_SIZE; i++) {
 325                 struct hlist_node *h, *g;
 326
 327                 hlist_for_each_safe(h, g, &br->hash[i]) {
 328                         struct net_bridge_fdb_entry *f
 329                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 330                         if (f->dst != p)
 331                                 continue;
 332
 333                         if (f->is_static && !do_all)
 334                                 continue;
 335
 336                         if (f->is_local)
 337                                 fdb_delete_local(br, p, f);
 338                         else
 339                                 fdb_delete(br, f);
 340                 }
 341         }
 342         spin_unlock_bh(&br->hash_lock);
 343 }
 344
 345 /* No locking or refcounting, assumes caller has rcu_read_lock */
 346 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 347                                           const unsigned char *addr,
 348                                           __u16 vid)
 349 {
 350         struct net_bridge_fdb_entry *fdb;
 351
 352         hlist_for_each_entry_rcu(fdb,
 353                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 354                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 355                     fdb->vlan_id == vid) {
 356                         if (unlikely(has_expired(br, fdb)))
 357                                 break;
 358                         return fdb;
 359                 }
 360         }
 361
 362         return NULL;
 363 }
 364
 365 #if IS_ENABLED(CONFIG_ATM_LANE)
 366 /* Interface used by ATM LANE hook to test
 367  * if an addr is on some other bridge port */
 368 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 369 {
 370         struct net_bridge_fdb_entry *fdb;
 371         struct net_bridge_port *port;
 372         int ret;
 373
 374         rcu_read_lock();
 375         port = br_port_get_rcu(dev);
 376         if (!port)
 377                 ret = 0;
 378         else {
 379                 fdb = __br_fdb_get(port->br, addr, 0);
 380                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 381                         fdb->dst->state == BR_STATE_FORWARDING;
 382         }
 383         rcu_read_unlock();
 384
 385         return ret;
 386 }
 387 #endif /* CONFIG_ATM_LANE */
 388
 389 /*
 390  * Fill buffer with forwarding table records in
 391  * the API format.
 392  */
 393 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 394                    unsigned long maxnum, unsigned long skip)
 395 {
 396         struct __fdb_entry *fe = buf;
 397         int i, num = 0;
 398         struct net_bridge_fdb_entry *f;
 399
 400         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 401
 402         rcu_read_lock();
 403         for (i = 0; i < BR_HASH_SIZE; i++) {
 404                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 405                         if (num >= maxnum)
 406                                 goto out;
 407
 408                         if (has_expired(br, f))
 409                                 continue;
 410
 411                         /* ignore pseudo entry for local MAC address */
 412                         if (!f->dst)
 413                                 continue;
 414
 415                         if (skip) {
 416                                 --skip;
 417                                 continue;
 418                         }
 419
 420                         /* convert from internal format to API */
 421                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 422
 423                         /* due to ABI compat need to split into hi/lo */
 424                         fe->port_no = f->dst->port_no;
 425                         fe->port_hi = f->dst->port_no >> 8;
 426
 427                         fe->is_local = f->is_local;
 428                         if (!f->is_static)
 429                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 430                         ++fe;
 431                         ++num;
 432                 }
 433         }
 434
 435  out:
 436         rcu_read_unlock();
 437
 438         return num;
 439 }
 440
 441 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 442                                              const unsigned char *addr,
 443                                              __u16 vid)
 444 {
 445         struct net_bridge_fdb_entry *fdb;
 446
 447         hlist_for_each_entry(fdb, head, hlist) {
 448                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 449                     fdb->vlan_id == vid)
 450                         return fdb;
 451         }
 452         return NULL;
 453 }
 454
 455 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 456                                                  const unsigned char *addr,
 457                                                  __u16 vid)
 458 {
 459         struct net_bridge_fdb_entry *fdb;
 460
 461         hlist_for_each_entry_rcu(fdb, head, hlist) {
 462                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 463                     fdb->vlan_id == vid)
 464                         return fdb;
 465         }
 466         return NULL;
 467 }
 468
 469 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 470                                                struct net_bridge_port *source,
 471                                                const unsigned char *addr,
 472                                                __u16 vid)
 473 {
 474         struct net_bridge_fdb_entry *fdb;
 475
 476         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 477         if (fdb) {
 478                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 479                 fdb->dst = source;
 480                 fdb->vlan_id = vid;
 481                 fdb->is_local = 0;
 482                 fdb->is_static = 0;
 483                 fdb->added_by_user = 0;
 484                 fdb->updated = fdb->used = jiffies;
 485                 hlist_add_head_rcu(&fdb->hlist, head);
 486         }
 487         return fdb;
 488 }
 489
 490 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 491                   const unsigned char *addr, u16 vid)
 492 {
 493         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 494         struct net_bridge_fdb_entry *fdb;
 495
 496         if (!is_valid_ether_addr(addr))
 497                 return -EINVAL;
 498
 499         fdb = fdb_find(head, addr, vid);
 500         if (fdb) {
 501                 /* it is okay to have multiple ports with same
 502                  * address, just use the first one.
 503                  */
 504                 if (fdb->is_local)
 505                         return 0;
 506                 br_warn(br, "adding interface %s with same address "
 507                        "as a received packet\n",
 508                        source ? source->dev->name : br->dev->name);
 509                 fdb_delete(br, fdb);
 510         }
 511
 512         fdb = fdb_create(head, source, addr, vid);
 513         if (!fdb)
 514                 return -ENOMEM;
 515
 516         fdb->is_local = fdb->is_static = 1;
 517         fdb_add_hw(br, addr);
 518         fdb_notify(br, fdb, RTM_NEWNEIGH);
 519         return 0;
 520 }
 521
 522 /* Add entry for local address of interface */
 523 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 524                   const unsigned char *addr, u16 vid)
 525 {
 526         int ret;
 527
 528         spin_lock_bh(&br->hash_lock);
 529         ret = fdb_insert(br, source, addr, vid);
 530         spin_unlock_bh(&br->hash_lock);
 531         return ret;
 532 }
 533
 534 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 535                    const unsigned char *addr, u16 vid, bool added_by_user)
 536 {
 537         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 538         struct net_bridge_fdb_entry *fdb;
 539         bool fdb_modified = false;
 540
 541         /* some users want to always flood. */
 542         if (hold_time(br) == 0)
 543                 return;
 544
 545         /* ignore packets unless we are using this port */
 546         if (!(source->state == BR_STATE_LEARNING ||
 547               source->state == BR_STATE_FORWARDING))
 548                 return;
 549
 550         fdb = fdb_find_rcu(head, addr, vid);
 551         if (likely(fdb)) {
 552                 /* attempt to update an entry for a local interface */
 553                 if (unlikely(fdb->is_local)) {
 554                         if (net_ratelimit())
 555                                 br_warn(br, "received packet on %s with "
 556                                         "own address as source address\n",
 557                                         source->dev->name);
 558                 } else {
 559                         /* fastpath: update of existing entry */
 560                         if (unlikely(source != fdb->dst)) {
 561                                 fdb->dst = source;
 562                                 fdb_modified = true;
 563                         }
 564                         fdb->updated = jiffies;
 565                         if (unlikely(added_by_user))
 566                                 fdb->added_by_user = 1;
 567                         if (unlikely(fdb_modified))
 568                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 569                 }
 570         } else {
 571                 spin_lock(&br->hash_lock);
 572                 if (likely(!fdb_find(head, addr, vid))) {
 573                         fdb = fdb_create(head, source, addr, vid);
 574                         if (fdb) {
 575                                 if (unlikely(added_by_user))
 576                                         fdb->added_by_user = 1;
 577                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 578                         }
 579                 }
 580                 /* else  we lose race and someone else inserts
 581                  * it first, don't bother updating
 582                  */
 583                 spin_unlock(&br->hash_lock);
 584         }
 585 }
 586
 587 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
 588 {
 589         if (fdb->is_local)
 590                 return NUD_PERMANENT;
 591         else if (fdb->is_static)
 592                 return NUD_NOARP;
 593         else if (has_expired(fdb->dst->br, fdb))
 594                 return NUD_STALE;
 595         else
 596                 return NUD_REACHABLE;
 597 }
 598
 599 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 600                          const struct net_bridge_fdb_entry *fdb,
 601                          u32 portid, u32 seq, int type, unsigned int flags)
 602 {
 603         unsigned long now = jiffies;
 604         struct nda_cacheinfo ci;
 605         struct nlmsghdr *nlh;
 606         struct ndmsg *ndm;
 607
 608         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 609         if (nlh == NULL)
 610                 return -EMSGSIZE;
 611
 612         ndm = nlmsg_data(nlh);
 613         ndm->ndm_family  = AF_BRIDGE;
 614         ndm->ndm_pad1    = 0;
 615         ndm->ndm_pad2    = 0;
 616         ndm->ndm_flags   = 0;
 617         ndm->ndm_type    = 0;
 618         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 619         ndm->ndm_state   = fdb_to_nud(fdb);
 620
 621         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 622                 goto nla_put_failure;
 623         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 624                 goto nla_put_failure;
 625         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 626         ci.ndm_confirmed = 0;
 627         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 628         ci.ndm_refcnt    = 0;
 629         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 630                 goto nla_put_failure;
 631
 632         if (nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 633                 goto nla_put_failure;
 634
 635         return nlmsg_end(skb, nlh);
 636
 637 nla_put_failure:
 638         nlmsg_cancel(skb, nlh);
 639         return -EMSGSIZE;
 640 }
 641
 642 static inline size_t fdb_nlmsg_size(void)
 643 {
 644         return NLMSG_ALIGN(sizeof(struct ndmsg))
 645                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 646                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 647                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 648                 + nla_total_size(sizeof(struct nda_cacheinfo));
 649 }
 650
 651 static void fdb_notify(struct net_bridge *br,
 652                        const struct net_bridge_fdb_entry *fdb, int type)
 653 {
 654         struct net *net = dev_net(br->dev);
 655         struct sk_buff *skb;
 656         int err = -ENOBUFS;
 657
 658         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 659         if (skb == NULL)
 660                 goto errout;
 661
 662         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 663         if (err < 0) {
 664                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 665                 WARN_ON(err == -EMSGSIZE);
 666                 kfree_skb(skb);
 667                 goto errout;
 668         }
 669         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 670         return;
 671 errout:
 672         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 673 }
 674
 675 /* Dump information about entries, in response to GETNEIGH */
 676 int br_fdb_dump(struct sk_buff *skb,
 677                 struct netlink_callback *cb,
 678                 struct net_device *dev,
 679                 struct net_device *filter_dev,
 680                 int idx)
 681 {
 682         struct net_bridge *br = netdev_priv(dev);
 683         int i;
 684
 685         if (!(dev->priv_flags & IFF_EBRIDGE))
 686                 goto out;
 687
 688         for (i = 0; i < BR_HASH_SIZE; i++) {
 689                 struct net_bridge_fdb_entry *f;
 690
 691                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 692                         if (idx < cb->args[0])
 693                                 goto skip;
 694
 695                         if (filter_dev && (!f->dst || !f->dst->dev ||
 696                                            f->dst->dev != filter_dev))
 697                                 goto skip;
 698
 699                         if (fdb_fill_info(skb, br, f,
 700                                           NETLINK_CB(cb->skb).portid,
 701                                           cb->nlh->nlmsg_seq,
 702                                           RTM_NEWNEIGH,
 703                                           NLM_F_MULTI) < 0)
 704                                 break;
 705 skip:
 706                         ++idx;
 707                 }
 708         }
 709
 710 out:
 711         return idx;
 712 }
 713
 714 /* Update (create or replace) forwarding database entry */
 715 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 716                          __u16 state, __u16 flags, __u16 vid)
 717 {
 718         struct net_bridge *br = source->br;
 719         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 720         struct net_bridge_fdb_entry *fdb;
 721         bool modified = false;
 722
 723         fdb = fdb_find(head, addr, vid);
 724         if (fdb == NULL) {
 725                 if (!(flags & NLM_F_CREATE))
 726                         return -ENOENT;
 727
 728                 fdb = fdb_create(head, source, addr, vid);
 729                 if (!fdb)
 730                         return -ENOMEM;
 731
 732                 modified = true;
 733         } else {
 734                 if (flags & NLM_F_EXCL)
 735                         return -EEXIST;
 736
 737                 if (fdb->dst != source) {
 738                         fdb->dst = source;
 739                         modified = true;
 740                 }
 741         }
 742
 743         if (fdb_to_nud(fdb) != state) {
 744                 if (state & NUD_PERMANENT) {
 745                         fdb->is_local = 1;
 746                         if (!fdb->is_static) {
 747                                 fdb->is_static = 1;
 748                                 fdb_add_hw(br, addr);
 749                         }
 750                 } else if (state & NUD_NOARP) {
 751                         fdb->is_local = 0;
 752                         if (!fdb->is_static) {
 753                                 fdb->is_static = 1;
 754                                 fdb_add_hw(br, addr);
 755                         }
 756                 } else {
 757                         fdb->is_local = 0;
 758                         if (fdb->is_static) {
 759                                 fdb->is_static = 0;
 760                                 fdb_del_hw(br, addr);
 761                         }
 762                 }
 763
 764                 modified = true;
 765         }
 766         fdb->added_by_user = 1;
 767
 768         fdb->used = jiffies;
 769         if (modified) {
 770                 fdb->updated = jiffies;
 771                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 772         }
 773
 774         return 0;
 775 }
 776
 777 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 778                const unsigned char *addr, u16 nlh_flags, u16 vid)
 779 {
 780         int err = 0;
 781
 782         if (ndm->ndm_flags & NTF_USE) {
 783                 rcu_read_lock();
 784                 br_fdb_update(p->br, p, addr, vid, true);
 785                 rcu_read_unlock();
 786         } else {
 787                 spin_lock_bh(&p->br->hash_lock);
 788                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 789                                     nlh_flags, vid);
 790                 spin_unlock_bh(&p->br->hash_lock);
 791         }
 792
 793         return err;
 794 }
 795
 796 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 797 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 798                struct net_device *dev,
 799                const unsigned char *addr, u16 nlh_flags)
 800 {
 801         struct net_bridge_port *p;
 802         int err = 0;
 803         struct net_port_vlans *pv;
 804         unsigned short vid = VLAN_N_VID;
 805
 806         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 807                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 808                 return -EINVAL;
 809         }
 810
 811         if (tb[NDA_VLAN]) {
 812                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 813                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 814                         return -EINVAL;
 815                 }
 816
 817                 vid = nla_get_u16(tb[NDA_VLAN]);
 818
 819                 if (!vid || vid >= VLAN_VID_MASK) {
 820                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 821                                 vid);
 822                         return -EINVAL;
 823                 }
 824         }
 825
 826         if (is_zero_ether_addr(addr)) {
 827                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 828                 return -EINVAL;
 829         }
 830
 831         p = br_port_get_rtnl(dev);
 832         if (p == NULL) {
 833                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 834                         dev->name);
 835                 return -EINVAL;
 836         }
 837
 838         pv = nbp_get_vlan_info(p);
 839         if (vid != VLAN_N_VID) {
 840                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 841                         pr_info("bridge: RTM_NEWNEIGH with unconfigured "
 842                                 "vlan %d on port %s\n", vid, dev->name);
 843                         return -EINVAL;
 844                 }
 845
 846                 /* VID was specified, so use it. */
 847                 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 848         } else {
 849                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 850                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 851                         goto out;
 852                 }
 853
 854                 /* We have vlans configured on this port and user didn't
 855                  * specify a VLAN.  To be nice, add/update entry for every
 856                  * vlan on this port.
 857                  */
 858                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 859                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 860                         if (err)
 861                                 goto out;
 862                 }
 863         }
 864
 865 out:
 866         return err;
 867 }
 868
 869 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
 870 {
 871         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 872         struct net_bridge_fdb_entry *fdb;
 873
 874         fdb = fdb_find(head, addr, vlan);
 875         if (!fdb)
 876                 return -ENOENT;
 877
 878         fdb_delete(br, fdb);
 879         return 0;
 880 }
 881
 882 static int __br_fdb_delete(struct net_bridge_port *p,
 883                            const unsigned char *addr, u16 vid)
 884 {
 885         int err;
 886
 887         spin_lock_bh(&p->br->hash_lock);
 888         err = fdb_delete_by_addr(p->br, addr, vid);
 889         spin_unlock_bh(&p->br->hash_lock);
 890
 891         return err;
 892 }
 893
 894 /* Remove neighbor entry with RTM_DELNEIGH */
 895 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 896                   struct net_device *dev,
 897                   const unsigned char *addr)
 898 {
 899         struct net_bridge_port *p;
 900         int err;
 901         struct net_port_vlans *pv;
 902         unsigned short vid = VLAN_N_VID;
 903
 904         if (tb[NDA_VLAN]) {
 905                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 906                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 907                         return -EINVAL;
 908                 }
 909
 910                 vid = nla_get_u16(tb[NDA_VLAN]);
 911
 912                 if (!vid || vid >= VLAN_VID_MASK) {
 913                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 914                                 vid);
 915                         return -EINVAL;
 916                 }
 917         }
 918         p = br_port_get_rtnl(dev);
 919         if (p == NULL) {
 920                 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 921                         dev->name);
 922                 return -EINVAL;
 923         }
 924
 925         pv = nbp_get_vlan_info(p);
 926         if (vid != VLAN_N_VID) {
 927                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 928                         pr_info("bridge: RTM_DELNEIGH with unconfigured "
 929                                 "vlan %d on port %s\n", vid, dev->name);
 930                         return -EINVAL;
 931                 }
 932
 933                 err = __br_fdb_delete(p, addr, vid);
 934         } else {
 935                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 936                         err = __br_fdb_delete(p, addr, 0);
 937                         goto out;
 938                 }
 939
 940                 /* We have vlans configured on this port and user didn't
 941                  * specify a VLAN.  To be nice, add/update entry for every
 942                  * vlan on this port.
 943                  */
 944                 err = -ENOENT;
 945                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 946                         err &= __br_fdb_delete(p, addr, vid);
 947                 }
 948         }
 949 out:
 950         return err;
 951 }
 952
 953 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
 954 {
 955         struct net_bridge_fdb_entry *fdb, *tmp;
 956         int i;
 957         int err;
 958
 959         ASSERT_RTNL();
 960
 961         for (i = 0; i < BR_HASH_SIZE; i++) {
 962                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
 963                         /* We only care for static entries */
 964                         if (!fdb->is_static)
 965                                 continue;
 966
 967                         err = dev_uc_add(p->dev, fdb->addr.addr);
 968                         if (err)
 969                                 goto rollback;
 970                 }
 971         }
 972         return 0;
 973
 974 rollback:
 975         for (i = 0; i < BR_HASH_SIZE; i++) {
 976                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
 977                         /* If we reached the fdb that failed, we can stop */
 978                         if (tmp == fdb)
 979                                 break;
 980
 981                         /* We only care for static entries */
 982                         if (!tmp->is_static)
 983                                 continue;
 984
 985                         dev_uc_del(p->dev, tmp->addr.addr);
 986                 }
 987         }
 988         return err;
 989 }
 990
 991 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
 992 {
 993         struct net_bridge_fdb_entry *fdb;
 994         int i;
 995
 996         ASSERT_RTNL();
 997
 998         for (i = 0; i < BR_HASH_SIZE; i++) {
 999                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1000                         /* We only care for static entries */
1001                         if (!fdb->is_static)
1002                                 continue;
1003
1004                         dev_uc_del(p->dev, fdb->addr.addr);
1005                 }
1006         }
1007 }