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