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 <net/switchdev.h>
  28 #include "br_private.h"
  29
  30 static struct kmem_cache *br_fdb_cache __read_mostly;
  31 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  32                                              const unsigned char *addr,
  33                                              __u16 vid);
  34 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  35                       const unsigned char *addr, u16 vid);
  36 static void fdb_notify(struct net_bridge *br,
  37                        const struct net_bridge_fdb_entry *, int);
  38
  39 static u32 fdb_salt __read_mostly;
  40
  41 int __init br_fdb_init(void)
  42 {
  43         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  44                                          sizeof(struct net_bridge_fdb_entry),
  45                                          0,
  46                                          SLAB_HWCACHE_ALIGN, NULL);
  47         if (!br_fdb_cache)
  48                 return -ENOMEM;
  49
  50         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  51         return 0;
  52 }
  53
  54 void br_fdb_fini(void)
  55 {
  56         kmem_cache_destroy(br_fdb_cache);
  57 }
  58
  59
  60 /* if topology_changing then use forward_delay (default 15 sec)
  61  * otherwise keep longer (default 5 minutes)
  62  */
  63 static inline unsigned long hold_time(const struct net_bridge *br)
  64 {
  65         return br->topology_change ? br->forward_delay : br->ageing_time;
  66 }
  67
  68 static inline int has_expired(const struct net_bridge *br,
  69                                   const struct net_bridge_fdb_entry *fdb)
  70 {
  71         return !fdb->is_static &&
  72                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  73 }
  74
  75 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  76 {
  77         /* use 1 byte of OUI and 3 bytes of NIC */
  78         u32 key = get_unaligned((u32 *)(mac + 2));
  79         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  80 }
  81
  82 static void fdb_rcu_free(struct rcu_head *head)
  83 {
  84         struct net_bridge_fdb_entry *ent
  85                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  86         kmem_cache_free(br_fdb_cache, ent);
  87 }
  88
  89 /* When a static FDB entry is added, the mac address from the entry is
  90  * added to the bridge private HW address list and all required ports
  91  * are then updated with the new information.
  92  * Called under RTNL.
  93  */
  94 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
  95 {
  96         int err;
  97         struct net_bridge_port *p;
  98
  99         ASSERT_RTNL();
 100
 101         list_for_each_entry(p, &br->port_list, list) {
 102                 if (!br_promisc_port(p)) {
 103                         err = dev_uc_add(p->dev, addr);
 104                         if (err)
 105                                 goto undo;
 106                 }
 107         }
 108
 109         return;
 110 undo:
 111         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 112                 if (!br_promisc_port(p))
 113                         dev_uc_del(p->dev, addr);
 114         }
 115 }
 116
 117 /* When a static FDB entry is deleted, the HW address from that entry is
 118  * also removed from the bridge private HW address list and updates all
 119  * the ports with needed information.
 120  * Called under RTNL.
 121  */
 122 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 123 {
 124         struct net_bridge_port *p;
 125
 126         ASSERT_RTNL();
 127
 128         list_for_each_entry(p, &br->port_list, list) {
 129                 if (!br_promisc_port(p))
 130                         dev_uc_del(p->dev, addr);
 131         }
 132 }
 133
 134 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 135 {
 136         struct switchdev_obj_port_fdb fdb = {
 137                 .obj = {
 138                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 139                         .flags = SWITCHDEV_F_DEFER,
 140                 },
 141                 .vid = f->vlan_id,
 142         };
 143
 144         ether_addr_copy(fdb.addr, f->addr.addr);
 145         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 146 }
 147
 148 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 149 {
 150         if (f->is_static)
 151                 fdb_del_hw_addr(br, f->addr.addr);
 152
 153         if (f->added_by_external_learn)
 154                 fdb_del_external_learn(f);
 155
 156         hlist_del_rcu(&f->hlist);
 157         fdb_notify(br, f, RTM_DELNEIGH);
 158         call_rcu(&f->rcu, fdb_rcu_free);
 159 }
 160
 161 /* Delete a local entry if no other port had the same address. */
 162 static void fdb_delete_local(struct net_bridge *br,
 163                              const struct net_bridge_port *p,
 164                              struct net_bridge_fdb_entry *f)
 165 {
 166         const unsigned char *addr = f->addr.addr;
 167         struct net_bridge_vlan_group *vg;
 168         const struct net_bridge_vlan *v;
 169         struct net_bridge_port *op;
 170         u16 vid = f->vlan_id;
 171
 172         /* Maybe another port has same hw addr? */
 173         list_for_each_entry(op, &br->port_list, list) {
 174                 vg = nbp_vlan_group(op);
 175                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 176                     (!vid || br_vlan_find(vg, vid))) {
 177                         f->dst = op;
 178                         f->added_by_user = 0;
 179                         return;
 180                 }
 181         }
 182
 183         vg = br_vlan_group(br);
 184         v = br_vlan_find(vg, vid);
 185         /* Maybe bridge device has same hw addr? */
 186         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 187             (!vid || (v && br_vlan_should_use(v)))) {
 188                 f->dst = NULL;
 189                 f->added_by_user = 0;
 190                 return;
 191         }
 192
 193         fdb_delete(br, f);
 194 }
 195
 196 void br_fdb_find_delete_local(struct net_bridge *br,
 197                               const struct net_bridge_port *p,
 198                               const unsigned char *addr, u16 vid)
 199 {
 200         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 201         struct net_bridge_fdb_entry *f;
 202
 203         spin_lock_bh(&br->hash_lock);
 204         f = fdb_find(head, addr, vid);
 205         if (f && f->is_local && !f->added_by_user && f->dst == p)
 206                 fdb_delete_local(br, p, f);
 207         spin_unlock_bh(&br->hash_lock);
 208 }
 209
 210 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 211 {
 212         struct net_bridge_vlan_group *vg;
 213         struct net_bridge *br = p->br;
 214         struct net_bridge_vlan *v;
 215         int i;
 216
 217         spin_lock_bh(&br->hash_lock);
 218
 219         vg = nbp_vlan_group(p);
 220         /* Search all chains since old address/hash is unknown */
 221         for (i = 0; i < BR_HASH_SIZE; i++) {
 222                 struct hlist_node *h;
 223                 hlist_for_each(h, &br->hash[i]) {
 224                         struct net_bridge_fdb_entry *f;
 225
 226                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 227                         if (f->dst == p && f->is_local && !f->added_by_user) {
 228                                 /* delete old one */
 229                                 fdb_delete_local(br, p, f);
 230
 231                                 /* if this port has no vlan information
 232                                  * configured, we can safely be done at
 233                                  * this point.
 234                                  */
 235                                 if (!vg || !vg->num_vlans)
 236                                         goto insert;
 237                         }
 238                 }
 239         }
 240
 241 insert:
 242         /* insert new address,  may fail if invalid address or dup. */
 243         fdb_insert(br, p, newaddr, 0);
 244
 245         if (!vg || !vg->num_vlans)
 246                 goto done;
 247
 248         /* Now add entries for every VLAN configured on the port.
 249          * This function runs under RTNL so the bitmap will not change
 250          * from under us.
 251          */
 252         list_for_each_entry(v, &vg->vlan_list, vlist)
 253                 fdb_insert(br, p, newaddr, v->vid);
 254
 255 done:
 256         spin_unlock_bh(&br->hash_lock);
 257 }
 258
 259 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 260 {
 261         struct net_bridge_vlan_group *vg;
 262         struct net_bridge_fdb_entry *f;
 263         struct net_bridge_vlan *v;
 264
 265         spin_lock_bh(&br->hash_lock);
 266
 267         /* If old entry was unassociated with any port, then delete it. */
 268         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 269         if (f && f->is_local && !f->dst)
 270                 fdb_delete_local(br, NULL, f);
 271
 272         fdb_insert(br, NULL, newaddr, 0);
 273         vg = br_vlan_group(br);
 274         if (!vg || !vg->num_vlans)
 275                 goto out;
 276         /* Now remove and add entries for every VLAN configured on the
 277          * bridge.  This function runs under RTNL so the bitmap will not
 278          * change from under us.
 279          */
 280         list_for_each_entry(v, &vg->vlan_list, vlist) {
 281                 f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 282                 if (f && f->is_local && !f->dst)
 283                         fdb_delete_local(br, NULL, f);
 284                 fdb_insert(br, NULL, newaddr, v->vid);
 285         }
 286 out:
 287         spin_unlock_bh(&br->hash_lock);
 288 }
 289
 290 void br_fdb_cleanup(unsigned long _data)
 291 {
 292         struct net_bridge *br = (struct net_bridge *)_data;
 293         unsigned long delay = hold_time(br);
 294         unsigned long next_timer = jiffies + br->ageing_time;
 295         int i;
 296
 297         spin_lock(&br->hash_lock);
 298         for (i = 0; i < BR_HASH_SIZE; i++) {
 299                 struct net_bridge_fdb_entry *f;
 300                 struct hlist_node *n;
 301
 302                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 303                         unsigned long this_timer;
 304                         if (f->is_static)
 305                                 continue;
 306                         if (f->added_by_external_learn)
 307                                 continue;
 308                         this_timer = f->updated + delay;
 309                         if (time_before_eq(this_timer, jiffies))
 310                                 fdb_delete(br, f);
 311                         else if (time_before(this_timer, next_timer))
 312                                 next_timer = this_timer;
 313                 }
 314         }
 315         spin_unlock(&br->hash_lock);
 316
 317         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 318 }
 319
 320 /* Completely flush all dynamic entries in forwarding database.*/
 321 void br_fdb_flush(struct net_bridge *br)
 322 {
 323         int i;
 324
 325         spin_lock_bh(&br->hash_lock);
 326         for (i = 0; i < BR_HASH_SIZE; i++) {
 327                 struct net_bridge_fdb_entry *f;
 328                 struct hlist_node *n;
 329                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 330                         if (!f->is_static)
 331                                 fdb_delete(br, f);
 332                 }
 333         }
 334         spin_unlock_bh(&br->hash_lock);
 335 }
 336
 337 /* Flush all entries referring to a specific port.
 338  * if do_all is set also flush static entries
 339  * if vid is set delete all entries that match the vlan_id
 340  */
 341 void br_fdb_delete_by_port(struct net_bridge *br,
 342                            const struct net_bridge_port *p,
 343                            u16 vid,
 344                            int do_all)
 345 {
 346         int i;
 347
 348         spin_lock_bh(&br->hash_lock);
 349         for (i = 0; i < BR_HASH_SIZE; i++) {
 350                 struct hlist_node *h, *g;
 351
 352                 hlist_for_each_safe(h, g, &br->hash[i]) {
 353                         struct net_bridge_fdb_entry *f
 354                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 355                         if (f->dst != p)
 356                                 continue;
 357
 358                         if (!do_all)
 359                                 if (f->is_static || (vid && f->vlan_id != vid))
 360                                         continue;
 361
 362                         if (f->is_local)
 363                                 fdb_delete_local(br, p, f);
 364                         else
 365                                 fdb_delete(br, f);
 366                 }
 367         }
 368         spin_unlock_bh(&br->hash_lock);
 369 }
 370
 371 /* No locking or refcounting, assumes caller has rcu_read_lock */
 372 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 373                                           const unsigned char *addr,
 374                                           __u16 vid)
 375 {
 376         struct net_bridge_fdb_entry *fdb;
 377
 378         hlist_for_each_entry_rcu(fdb,
 379                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 380                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 381                     fdb->vlan_id == vid) {
 382                         if (unlikely(has_expired(br, fdb)))
 383                                 break;
 384                         return fdb;
 385                 }
 386         }
 387
 388         return NULL;
 389 }
 390
 391 #if IS_ENABLED(CONFIG_ATM_LANE)
 392 /* Interface used by ATM LANE hook to test
 393  * if an addr is on some other bridge port */
 394 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 395 {
 396         struct net_bridge_fdb_entry *fdb;
 397         struct net_bridge_port *port;
 398         int ret;
 399
 400         rcu_read_lock();
 401         port = br_port_get_rcu(dev);
 402         if (!port)
 403                 ret = 0;
 404         else {
 405                 fdb = __br_fdb_get(port->br, addr, 0);
 406                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 407                         fdb->dst->state == BR_STATE_FORWARDING;
 408         }
 409         rcu_read_unlock();
 410
 411         return ret;
 412 }
 413 #endif /* CONFIG_ATM_LANE */
 414
 415 /*
 416  * Fill buffer with forwarding table records in
 417  * the API format.
 418  */
 419 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 420                    unsigned long maxnum, unsigned long skip)
 421 {
 422         struct __fdb_entry *fe = buf;
 423         int i, num = 0;
 424         struct net_bridge_fdb_entry *f;
 425
 426         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 427
 428         rcu_read_lock();
 429         for (i = 0; i < BR_HASH_SIZE; i++) {
 430                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 431                         if (num >= maxnum)
 432                                 goto out;
 433
 434                         if (has_expired(br, f))
 435                                 continue;
 436
 437                         /* ignore pseudo entry for local MAC address */
 438                         if (!f->dst)
 439                                 continue;
 440
 441                         if (skip) {
 442                                 --skip;
 443                                 continue;
 444                         }
 445
 446                         /* convert from internal format to API */
 447                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 448
 449                         /* due to ABI compat need to split into hi/lo */
 450                         fe->port_no = f->dst->port_no;
 451                         fe->port_hi = f->dst->port_no >> 8;
 452
 453                         fe->is_local = f->is_local;
 454                         if (!f->is_static)
 455                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 456                         ++fe;
 457                         ++num;
 458                 }
 459         }
 460
 461  out:
 462         rcu_read_unlock();
 463
 464         return num;
 465 }
 466
 467 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 468                                              const unsigned char *addr,
 469                                              __u16 vid)
 470 {
 471         struct net_bridge_fdb_entry *fdb;
 472
 473         hlist_for_each_entry(fdb, head, hlist) {
 474                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 475                     fdb->vlan_id == vid)
 476                         return fdb;
 477         }
 478         return NULL;
 479 }
 480
 481 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 482                                                  const unsigned char *addr,
 483                                                  __u16 vid)
 484 {
 485         struct net_bridge_fdb_entry *fdb;
 486
 487         hlist_for_each_entry_rcu(fdb, head, hlist) {
 488                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 489                     fdb->vlan_id == vid)
 490                         return fdb;
 491         }
 492         return NULL;
 493 }
 494
 495 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 496                                                struct net_bridge_port *source,
 497                                                const unsigned char *addr,
 498                                                __u16 vid)
 499 {
 500         struct net_bridge_fdb_entry *fdb;
 501
 502         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 503         if (fdb) {
 504                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 505                 fdb->dst = source;
 506                 fdb->vlan_id = vid;
 507                 fdb->is_local = 0;
 508                 fdb->is_static = 0;
 509                 fdb->added_by_user = 0;
 510                 fdb->added_by_external_learn = 0;
 511                 fdb->updated = fdb->used = jiffies;
 512                 hlist_add_head_rcu(&fdb->hlist, head);
 513         }
 514         return fdb;
 515 }
 516
 517 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 518                   const unsigned char *addr, u16 vid)
 519 {
 520         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 521         struct net_bridge_fdb_entry *fdb;
 522
 523         if (!is_valid_ether_addr(addr))
 524                 return -EINVAL;
 525
 526         fdb = fdb_find(head, addr, vid);
 527         if (fdb) {
 528                 /* it is okay to have multiple ports with same
 529                  * address, just use the first one.
 530                  */
 531                 if (fdb->is_local)
 532                         return 0;
 533                 br_warn(br, "adding interface %s with same address "
 534                        "as a received packet\n",
 535                        source ? source->dev->name : br->dev->name);
 536                 fdb_delete(br, fdb);
 537         }
 538
 539         fdb = fdb_create(head, source, addr, vid);
 540         if (!fdb)
 541                 return -ENOMEM;
 542
 543         fdb->is_local = fdb->is_static = 1;
 544         fdb_add_hw_addr(br, addr);
 545         fdb_notify(br, fdb, RTM_NEWNEIGH);
 546         return 0;
 547 }
 548
 549 /* Add entry for local address of interface */
 550 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 551                   const unsigned char *addr, u16 vid)
 552 {
 553         int ret;
 554
 555         spin_lock_bh(&br->hash_lock);
 556         ret = fdb_insert(br, source, addr, vid);
 557         spin_unlock_bh(&br->hash_lock);
 558         return ret;
 559 }
 560
 561 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 562                    const unsigned char *addr, u16 vid, bool added_by_user)
 563 {
 564         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 565         struct net_bridge_fdb_entry *fdb;
 566         bool fdb_modified = false;
 567
 568         /* some users want to always flood. */
 569         if (hold_time(br) == 0)
 570                 return;
 571
 572         /* ignore packets unless we are using this port */
 573         if (!(source->state == BR_STATE_LEARNING ||
 574               source->state == BR_STATE_FORWARDING))
 575                 return;
 576
 577         fdb = fdb_find_rcu(head, addr, vid);
 578         if (likely(fdb)) {
 579                 /* attempt to update an entry for a local interface */
 580                 if (unlikely(fdb->is_local)) {
 581                         if (net_ratelimit())
 582                                 br_warn(br, "received packet on %s with "
 583                                         "own address as source address\n",
 584                                         source->dev->name);
 585                 } else {
 586                         /* fastpath: update of existing entry */
 587                         if (unlikely(source != fdb->dst)) {
 588                                 fdb->dst = source;
 589                                 fdb_modified = true;
 590                         }
 591                         fdb->updated = jiffies;
 592                         if (unlikely(added_by_user))
 593                                 fdb->added_by_user = 1;
 594                         if (unlikely(fdb_modified))
 595                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 596                 }
 597         } else {
 598                 spin_lock(&br->hash_lock);
 599                 if (likely(!fdb_find(head, addr, vid))) {
 600                         fdb = fdb_create(head, source, addr, vid);
 601                         if (fdb) {
 602                                 if (unlikely(added_by_user))
 603                                         fdb->added_by_user = 1;
 604                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 605                         }
 606                 }
 607                 /* else  we lose race and someone else inserts
 608                  * it first, don't bother updating
 609                  */
 610                 spin_unlock(&br->hash_lock);
 611         }
 612 }
 613
 614 static int fdb_to_nud(const struct net_bridge *br,
 615                       const struct net_bridge_fdb_entry *fdb)
 616 {
 617         if (fdb->is_local)
 618                 return NUD_PERMANENT;
 619         else if (fdb->is_static)
 620                 return NUD_NOARP;
 621         else if (has_expired(br, fdb))
 622                 return NUD_STALE;
 623         else
 624                 return NUD_REACHABLE;
 625 }
 626
 627 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 628                          const struct net_bridge_fdb_entry *fdb,
 629                          u32 portid, u32 seq, int type, unsigned int flags)
 630 {
 631         unsigned long now = jiffies;
 632         struct nda_cacheinfo ci;
 633         struct nlmsghdr *nlh;
 634         struct ndmsg *ndm;
 635
 636         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 637         if (nlh == NULL)
 638                 return -EMSGSIZE;
 639
 640         ndm = nlmsg_data(nlh);
 641         ndm->ndm_family  = AF_BRIDGE;
 642         ndm->ndm_pad1    = 0;
 643         ndm->ndm_pad2    = 0;
 644         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 645         ndm->ndm_type    = 0;
 646         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 647         ndm->ndm_state   = fdb_to_nud(br, fdb);
 648
 649         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 650                 goto nla_put_failure;
 651         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 652                 goto nla_put_failure;
 653         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 654         ci.ndm_confirmed = 0;
 655         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 656         ci.ndm_refcnt    = 0;
 657         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 658                 goto nla_put_failure;
 659
 660         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 661                 goto nla_put_failure;
 662
 663         nlmsg_end(skb, nlh);
 664         return 0;
 665
 666 nla_put_failure:
 667         nlmsg_cancel(skb, nlh);
 668         return -EMSGSIZE;
 669 }
 670
 671 static inline size_t fdb_nlmsg_size(void)
 672 {
 673         return NLMSG_ALIGN(sizeof(struct ndmsg))
 674                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 675                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 676                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 677                 + nla_total_size(sizeof(struct nda_cacheinfo));
 678 }
 679
 680 static void fdb_notify(struct net_bridge *br,
 681                        const struct net_bridge_fdb_entry *fdb, int type)
 682 {
 683         struct net *net = dev_net(br->dev);
 684         struct sk_buff *skb;
 685         int err = -ENOBUFS;
 686
 687         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 688         if (skb == NULL)
 689                 goto errout;
 690
 691         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 692         if (err < 0) {
 693                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 694                 WARN_ON(err == -EMSGSIZE);
 695                 kfree_skb(skb);
 696                 goto errout;
 697         }
 698         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 699         return;
 700 errout:
 701         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 702 }
 703
 704 /* Dump information about entries, in response to GETNEIGH */
 705 int br_fdb_dump(struct sk_buff *skb,
 706                 struct netlink_callback *cb,
 707                 struct net_device *dev,
 708                 struct net_device *filter_dev,
 709                 int idx)
 710 {
 711         struct net_bridge *br = netdev_priv(dev);
 712         int i;
 713
 714         if (!(dev->priv_flags & IFF_EBRIDGE))
 715                 goto out;
 716
 717         if (!filter_dev)
 718                 idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 719
 720         for (i = 0; i < BR_HASH_SIZE; i++) {
 721                 struct net_bridge_fdb_entry *f;
 722
 723                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 724                         if (idx < cb->args[0])
 725                                 goto skip;
 726
 727                         if (filter_dev &&
 728                             (!f->dst || f->dst->dev != filter_dev)) {
 729                                 if (filter_dev != dev)
 730                                         goto skip;
 731                                 /* !f->dst is a special case for bridge
 732                                  * It means the MAC belongs to the bridge
 733                                  * Therefore need a little more filtering
 734                                  * we only want to dump the !f->dst case
 735                                  */
 736                                 if (f->dst)
 737                                         goto skip;
 738                         }
 739                         if (!filter_dev && f->dst)
 740                                 goto skip;
 741
 742                         if (fdb_fill_info(skb, br, f,
 743                                           NETLINK_CB(cb->skb).portid,
 744                                           cb->nlh->nlmsg_seq,
 745                                           RTM_NEWNEIGH,
 746                                           NLM_F_MULTI) < 0)
 747                                 break;
 748 skip:
 749                         ++idx;
 750                 }
 751         }
 752
 753 out:
 754         return idx;
 755 }
 756
 757 /* Update (create or replace) forwarding database entry */
 758 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 759                          __u16 state, __u16 flags, __u16 vid)
 760 {
 761         struct net_bridge *br = source->br;
 762         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 763         struct net_bridge_fdb_entry *fdb;
 764         bool modified = false;
 765
 766         /* If the port cannot learn allow only local and static entries */
 767         if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 768             !(source->state == BR_STATE_LEARNING ||
 769               source->state == BR_STATE_FORWARDING))
 770                 return -EPERM;
 771
 772         fdb = fdb_find(head, addr, vid);
 773         if (fdb == NULL) {
 774                 if (!(flags & NLM_F_CREATE))
 775                         return -ENOENT;
 776
 777                 fdb = fdb_create(head, source, addr, vid);
 778                 if (!fdb)
 779                         return -ENOMEM;
 780
 781                 modified = true;
 782         } else {
 783                 if (flags & NLM_F_EXCL)
 784                         return -EEXIST;
 785
 786                 if (fdb->dst != source) {
 787                         fdb->dst = source;
 788                         modified = true;
 789                 }
 790         }
 791
 792         if (fdb_to_nud(br, fdb) != state) {
 793                 if (state & NUD_PERMANENT) {
 794                         fdb->is_local = 1;
 795                         if (!fdb->is_static) {
 796                                 fdb->is_static = 1;
 797                                 fdb_add_hw_addr(br, addr);
 798                         }
 799                 } else if (state & NUD_NOARP) {
 800                         fdb->is_local = 0;
 801                         if (!fdb->is_static) {
 802                                 fdb->is_static = 1;
 803                                 fdb_add_hw_addr(br, addr);
 804                         }
 805                 } else {
 806                         fdb->is_local = 0;
 807                         if (fdb->is_static) {
 808                                 fdb->is_static = 0;
 809                                 fdb_del_hw_addr(br, addr);
 810                         }
 811                 }
 812
 813                 modified = true;
 814         }
 815         fdb->added_by_user = 1;
 816
 817         fdb->used = jiffies;
 818         if (modified) {
 819                 fdb->updated = jiffies;
 820                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 821         }
 822
 823         return 0;
 824 }
 825
 826 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 827                const unsigned char *addr, u16 nlh_flags, u16 vid)
 828 {
 829         int err = 0;
 830
 831         if (ndm->ndm_flags & NTF_USE) {
 832                 local_bh_disable();
 833                 rcu_read_lock();
 834                 br_fdb_update(p->br, p, addr, vid, true);
 835                 rcu_read_unlock();
 836                 local_bh_enable();
 837         } else {
 838                 spin_lock_bh(&p->br->hash_lock);
 839                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 840                                     nlh_flags, vid);
 841                 spin_unlock_bh(&p->br->hash_lock);
 842         }
 843
 844         return err;
 845 }
 846
 847 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 848 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 849                struct net_device *dev,
 850                const unsigned char *addr, u16 vid, u16 nlh_flags)
 851 {
 852         struct net_bridge_vlan_group *vg;
 853         struct net_bridge_port *p = NULL;
 854         struct net_bridge_vlan *v;
 855         struct net_bridge *br = NULL;
 856         int err = 0;
 857
 858         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 859                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 860                 return -EINVAL;
 861         }
 862
 863         if (is_zero_ether_addr(addr)) {
 864                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 865                 return -EINVAL;
 866         }
 867
 868         if (dev->priv_flags & IFF_EBRIDGE) {
 869                 br = netdev_priv(dev);
 870                 vg = br_vlan_group(br);
 871         } else {
 872                 p = br_port_get_rtnl(dev);
 873                 if (!p) {
 874                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 875                                 dev->name);
 876                         return -EINVAL;
 877                 }
 878                 vg = nbp_vlan_group(p);
 879         }
 880
 881         if (vid) {
 882                 v = br_vlan_find(vg, vid);
 883                 if (!v || !br_vlan_should_use(v)) {
 884                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 885                         return -EINVAL;
 886                 }
 887
 888                 /* VID was specified, so use it. */
 889                 if (dev->priv_flags & IFF_EBRIDGE)
 890                         err = br_fdb_insert(br, NULL, addr, vid);
 891                 else
 892                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 893         } else {
 894                 if (dev->priv_flags & IFF_EBRIDGE)
 895                         err = br_fdb_insert(br, NULL, addr, 0);
 896                 else
 897                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 898                 if (err || !vg || !vg->num_vlans)
 899                         goto out;
 900
 901                 /* We have vlans configured on this port and user didn't
 902                  * specify a VLAN.  To be nice, add/update entry for every
 903                  * vlan on this port.
 904                  */
 905                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 906                         if (!br_vlan_should_use(v))
 907                                 continue;
 908                         if (dev->priv_flags & IFF_EBRIDGE)
 909                                 err = br_fdb_insert(br, NULL, addr, v->vid);
 910                         else
 911                                 err = __br_fdb_add(ndm, p, addr, nlh_flags,
 912                                                    v->vid);
 913                         if (err)
 914                                 goto out;
 915                 }
 916         }
 917
 918 out:
 919         return err;
 920 }
 921
 922 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 923                               u16 vid)
 924 {
 925         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 926         struct net_bridge_fdb_entry *fdb;
 927
 928         fdb = fdb_find(head, addr, vid);
 929         if (!fdb)
 930                 return -ENOENT;
 931
 932         fdb_delete(br, fdb);
 933         return 0;
 934 }
 935
 936 static int __br_fdb_delete_by_addr(struct net_bridge *br,
 937                                    const unsigned char *addr, u16 vid)
 938 {
 939         int err;
 940
 941         spin_lock_bh(&br->hash_lock);
 942         err = fdb_delete_by_addr(br, addr, vid);
 943         spin_unlock_bh(&br->hash_lock);
 944
 945         return err;
 946 }
 947
 948 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 949                                        const u8 *addr, u16 vlan)
 950 {
 951         struct net_bridge *br = p->br;
 952         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 953         struct net_bridge_fdb_entry *fdb;
 954
 955         fdb = fdb_find(head, addr, vlan);
 956         if (!fdb || fdb->dst != p)
 957                 return -ENOENT;
 958
 959         fdb_delete(br, fdb);
 960         return 0;
 961 }
 962
 963 static int __br_fdb_delete(struct net_bridge_port *p,
 964                            const unsigned char *addr, u16 vid)
 965 {
 966         int err;
 967
 968         spin_lock_bh(&p->br->hash_lock);
 969         err = fdb_delete_by_addr_and_port(p, addr, vid);
 970         spin_unlock_bh(&p->br->hash_lock);
 971
 972         return err;
 973 }
 974
 975 /* Remove neighbor entry with RTM_DELNEIGH */
 976 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 977                   struct net_device *dev,
 978                   const unsigned char *addr, u16 vid)
 979 {
 980         struct net_bridge_vlan_group *vg;
 981         struct net_bridge_port *p = NULL;
 982         struct net_bridge_vlan *v;
 983         struct net_bridge *br = NULL;
 984         int err;
 985
 986         if (dev->priv_flags & IFF_EBRIDGE) {
 987                 br = netdev_priv(dev);
 988                 vg = br_vlan_group(br);
 989         } else {
 990                 p = br_port_get_rtnl(dev);
 991                 if (!p) {
 992                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 993                                 dev->name);
 994                         return -EINVAL;
 995                 }
 996                 vg = nbp_vlan_group(p);
 997         }
 998
 999         if (vid) {
1000                 v = br_vlan_find(vg, vid);
1001                 if (!v) {
1002                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1003                         return -EINVAL;
1004                 }
1005
1006                 if (dev->priv_flags & IFF_EBRIDGE)
1007                         err = __br_fdb_delete_by_addr(br, addr, vid);
1008                 else
1009                         err = __br_fdb_delete(p, addr, vid);
1010         } else {
1011                 err = -ENOENT;
1012                 if (dev->priv_flags & IFF_EBRIDGE)
1013                         err = __br_fdb_delete_by_addr(br, addr, 0);
1014                 else
1015                         err &= __br_fdb_delete(p, addr, 0);
1016
1017                 if (!vg || !vg->num_vlans)
1018                         goto out;
1019
1020                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1021                         if (!br_vlan_should_use(v))
1022                                 continue;
1023                         if (dev->priv_flags & IFF_EBRIDGE)
1024                                 err = __br_fdb_delete_by_addr(br, addr, v->vid);
1025                         else
1026                                 err &= __br_fdb_delete(p, addr, v->vid);
1027                 }
1028         }
1029 out:
1030         return err;
1031 }
1032
1033 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1034 {
1035         struct net_bridge_fdb_entry *fdb, *tmp;
1036         int i;
1037         int err;
1038
1039         ASSERT_RTNL();
1040
1041         for (i = 0; i < BR_HASH_SIZE; i++) {
1042                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1043                         /* We only care for static entries */
1044                         if (!fdb->is_static)
1045                                 continue;
1046
1047                         err = dev_uc_add(p->dev, fdb->addr.addr);
1048                         if (err)
1049                                 goto rollback;
1050                 }
1051         }
1052         return 0;
1053
1054 rollback:
1055         for (i = 0; i < BR_HASH_SIZE; i++) {
1056                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1057                         /* If we reached the fdb that failed, we can stop */
1058                         if (tmp == fdb)
1059                                 break;
1060
1061                         /* We only care for static entries */
1062                         if (!tmp->is_static)
1063                                 continue;
1064
1065                         dev_uc_del(p->dev, tmp->addr.addr);
1066                 }
1067         }
1068         return err;
1069 }
1070
1071 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1072 {
1073         struct net_bridge_fdb_entry *fdb;
1074         int i;
1075
1076         ASSERT_RTNL();
1077
1078         for (i = 0; i < BR_HASH_SIZE; i++) {
1079                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1080                         /* We only care for static entries */
1081                         if (!fdb->is_static)
1082                                 continue;
1083
1084                         dev_uc_del(p->dev, fdb->addr.addr);
1085                 }
1086         }
1087 }
1088
1089 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1090                               const unsigned char *addr, u16 vid)
1091 {
1092         struct hlist_head *head;
1093         struct net_bridge_fdb_entry *fdb;
1094         int err = 0;
1095
1096         ASSERT_RTNL();
1097         spin_lock_bh(&br->hash_lock);
1098
1099         head = &br->hash[br_mac_hash(addr, vid)];
1100         fdb = fdb_find(head, addr, vid);
1101         if (!fdb) {
1102                 fdb = fdb_create(head, p, addr, vid);
1103                 if (!fdb) {
1104                         err = -ENOMEM;
1105                         goto err_unlock;
1106                 }
1107                 fdb->added_by_external_learn = 1;
1108                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1109         } else if (fdb->added_by_external_learn) {
1110                 /* Refresh entry */
1111                 fdb->updated = fdb->used = jiffies;
1112         } else if (!fdb->added_by_user) {
1113                 /* Take over SW learned entry */
1114                 fdb->added_by_external_learn = 1;
1115                 fdb->updated = jiffies;
1116                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1117         }
1118
1119 err_unlock:
1120         spin_unlock_bh(&br->hash_lock);
1121
1122         return err;
1123 }
1124
1125 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1126                               const unsigned char *addr, u16 vid)
1127 {
1128         struct hlist_head *head;
1129         struct net_bridge_fdb_entry *fdb;
1130         int err = 0;
1131
1132         ASSERT_RTNL();
1133         spin_lock_bh(&br->hash_lock);
1134
1135         head = &br->hash[br_mac_hash(addr, vid)];
1136         fdb = fdb_find(head, addr, vid);
1137         if (fdb && fdb->added_by_external_learn)
1138                 fdb_delete(br, fdb);
1139         else
1140                 err = -ENOENT;
1141
1142         spin_unlock_bh(&br->hash_lock);
1143
1144         return err;
1145 }