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