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 int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  32                       const unsigned char *addr, u16 vid);
  33 static void fdb_notify(struct net_bridge *br,
  34                        const struct net_bridge_fdb_entry *, int);
  35
  36 static u32 fdb_salt __read_mostly;
  37
  38 int __init br_fdb_init(void)
  39 {
  40         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  41                                          sizeof(struct net_bridge_fdb_entry),
  42                                          0,
  43                                          SLAB_HWCACHE_ALIGN, NULL);
  44         if (!br_fdb_cache)
  45                 return -ENOMEM;
  46
  47         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  48         return 0;
  49 }
  50
  51 void br_fdb_fini(void)
  52 {
  53         kmem_cache_destroy(br_fdb_cache);
  54 }
  55
  56
  57 /* if topology_changing then use forward_delay (default 15 sec)
  58  * otherwise keep longer (default 5 minutes)
  59  */
  60 static inline unsigned long hold_time(const struct net_bridge *br)
  61 {
  62         return br->topology_change ? br->forward_delay : br->ageing_time;
  63 }
  64
  65 static inline int has_expired(const struct net_bridge *br,
  66                                   const struct net_bridge_fdb_entry *fdb)
  67 {
  68         return !fdb->is_static && !fdb->added_by_external_learn &&
  69                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  70 }
  71
  72 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  73 {
  74         /* use 1 byte of OUI and 3 bytes of NIC */
  75         u32 key = get_unaligned((u32 *)(mac + 2));
  76         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  77 }
  78
  79 static void fdb_rcu_free(struct rcu_head *head)
  80 {
  81         struct net_bridge_fdb_entry *ent
  82                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  83         kmem_cache_free(br_fdb_cache, ent);
  84 }
  85
  86 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
  87                                                  const unsigned char *addr,
  88                                                  __u16 vid)
  89 {
  90         struct net_bridge_fdb_entry *f;
  91
  92         WARN_ON_ONCE(!rcu_read_lock_held());
  93
  94         hlist_for_each_entry_rcu(f, head, hlist)
  95                 if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
  96                         break;
  97
  98         return f;
  99 }
 100
 101 /* requires bridge hash_lock */
 102 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 103                                                 const unsigned char *addr,
 104                                                 __u16 vid)
 105 {
 106         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 107         struct net_bridge_fdb_entry *fdb;
 108
 109         lockdep_assert_held_once(&br->hash_lock);
 110
 111         rcu_read_lock();
 112         fdb = fdb_find_rcu(head, addr, vid);
 113         rcu_read_unlock();
 114
 115         return fdb;
 116 }
 117
 118 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 119                                              const unsigned char *addr,
 120                                              __u16 vid)
 121 {
 122         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 123
 124         return fdb_find_rcu(head, addr, vid);
 125 }
 126
 127 /* When a static FDB entry is added, the mac address from the entry is
 128  * added to the bridge private HW address list and all required ports
 129  * are then updated with the new information.
 130  * Called under RTNL.
 131  */
 132 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 133 {
 134         int err;
 135         struct net_bridge_port *p;
 136
 137         ASSERT_RTNL();
 138
 139         list_for_each_entry(p, &br->port_list, list) {
 140                 if (!br_promisc_port(p)) {
 141                         err = dev_uc_add(p->dev, addr);
 142                         if (err)
 143                                 goto undo;
 144                 }
 145         }
 146
 147         return;
 148 undo:
 149         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 150                 if (!br_promisc_port(p))
 151                         dev_uc_del(p->dev, addr);
 152         }
 153 }
 154
 155 /* When a static FDB entry is deleted, the HW address from that entry is
 156  * also removed from the bridge private HW address list and updates all
 157  * the ports with needed information.
 158  * Called under RTNL.
 159  */
 160 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 161 {
 162         struct net_bridge_port *p;
 163
 164         ASSERT_RTNL();
 165
 166         list_for_each_entry(p, &br->port_list, list) {
 167                 if (!br_promisc_port(p))
 168                         dev_uc_del(p->dev, addr);
 169         }
 170 }
 171
 172 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 173 {
 174         struct switchdev_obj_port_fdb fdb = {
 175                 .obj = {
 176                         .orig_dev = f->dst->dev,
 177                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 178                         .flags = SWITCHDEV_F_DEFER,
 179                 },
 180                 .vid = f->vlan_id,
 181         };
 182
 183         ether_addr_copy(fdb.addr, f->addr.addr);
 184         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 185 }
 186
 187 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 188 {
 189         if (f->is_static)
 190                 fdb_del_hw_addr(br, f->addr.addr);
 191
 192         if (f->added_by_external_learn)
 193                 fdb_del_external_learn(f);
 194
 195         hlist_del_init_rcu(&f->hlist);
 196         fdb_notify(br, f, RTM_DELNEIGH);
 197         call_rcu(&f->rcu, fdb_rcu_free);
 198 }
 199
 200 /* Delete a local entry if no other port had the same address. */
 201 static void fdb_delete_local(struct net_bridge *br,
 202                              const struct net_bridge_port *p,
 203                              struct net_bridge_fdb_entry *f)
 204 {
 205         const unsigned char *addr = f->addr.addr;
 206         struct net_bridge_vlan_group *vg;
 207         const struct net_bridge_vlan *v;
 208         struct net_bridge_port *op;
 209         u16 vid = f->vlan_id;
 210
 211         /* Maybe another port has same hw addr? */
 212         list_for_each_entry(op, &br->port_list, list) {
 213                 vg = nbp_vlan_group(op);
 214                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 215                     (!vid || br_vlan_find(vg, vid))) {
 216                         f->dst = op;
 217                         f->added_by_user = 0;
 218                         return;
 219                 }
 220         }
 221
 222         vg = br_vlan_group(br);
 223         v = br_vlan_find(vg, vid);
 224         /* Maybe bridge device has same hw addr? */
 225         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 226             (!vid || (v && br_vlan_should_use(v)))) {
 227                 f->dst = NULL;
 228                 f->added_by_user = 0;
 229                 return;
 230         }
 231
 232         fdb_delete(br, f);
 233 }
 234
 235 void br_fdb_find_delete_local(struct net_bridge *br,
 236                               const struct net_bridge_port *p,
 237                               const unsigned char *addr, u16 vid)
 238 {
 239         struct net_bridge_fdb_entry *f;
 240
 241         spin_lock_bh(&br->hash_lock);
 242         f = br_fdb_find(br, addr, vid);
 243         if (f && f->is_local && !f->added_by_user && f->dst == p)
 244                 fdb_delete_local(br, p, f);
 245         spin_unlock_bh(&br->hash_lock);
 246 }
 247
 248 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 249 {
 250         struct net_bridge_vlan_group *vg;
 251         struct net_bridge *br = p->br;
 252         struct net_bridge_vlan *v;
 253         int i;
 254
 255         spin_lock_bh(&br->hash_lock);
 256
 257         vg = nbp_vlan_group(p);
 258         /* Search all chains since old address/hash is unknown */
 259         for (i = 0; i < BR_HASH_SIZE; i++) {
 260                 struct hlist_node *h;
 261                 hlist_for_each(h, &br->hash[i]) {
 262                         struct net_bridge_fdb_entry *f;
 263
 264                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 265                         if (f->dst == p && f->is_local && !f->added_by_user) {
 266                                 /* delete old one */
 267                                 fdb_delete_local(br, p, f);
 268
 269                                 /* if this port has no vlan information
 270                                  * configured, we can safely be done at
 271                                  * this point.
 272                                  */
 273                                 if (!vg || !vg->num_vlans)
 274                                         goto insert;
 275                         }
 276                 }
 277         }
 278
 279 insert:
 280         /* insert new address,  may fail if invalid address or dup. */
 281         fdb_insert(br, p, newaddr, 0);
 282
 283         if (!vg || !vg->num_vlans)
 284                 goto done;
 285
 286         /* Now add entries for every VLAN configured on the port.
 287          * This function runs under RTNL so the bitmap will not change
 288          * from under us.
 289          */
 290         list_for_each_entry(v, &vg->vlan_list, vlist)
 291                 fdb_insert(br, p, newaddr, v->vid);
 292
 293 done:
 294         spin_unlock_bh(&br->hash_lock);
 295 }
 296
 297 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 298 {
 299         struct net_bridge_vlan_group *vg;
 300         struct net_bridge_fdb_entry *f;
 301         struct net_bridge_vlan *v;
 302
 303         spin_lock_bh(&br->hash_lock);
 304
 305         /* If old entry was unassociated with any port, then delete it. */
 306         f = br_fdb_find(br, br->dev->dev_addr, 0);
 307         if (f && f->is_local && !f->dst && !f->added_by_user)
 308                 fdb_delete_local(br, NULL, f);
 309
 310         fdb_insert(br, NULL, newaddr, 0);
 311         vg = br_vlan_group(br);
 312         if (!vg || !vg->num_vlans)
 313                 goto out;
 314         /* Now remove and add entries for every VLAN configured on the
 315          * bridge.  This function runs under RTNL so the bitmap will not
 316          * change from under us.
 317          */
 318         list_for_each_entry(v, &vg->vlan_list, vlist) {
 319                 if (!br_vlan_should_use(v))
 320                         continue;
 321                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 322                 if (f && f->is_local && !f->dst && !f->added_by_user)
 323                         fdb_delete_local(br, NULL, f);
 324                 fdb_insert(br, NULL, newaddr, v->vid);
 325         }
 326 out:
 327         spin_unlock_bh(&br->hash_lock);
 328 }
 329
 330 void br_fdb_cleanup(struct work_struct *work)
 331 {
 332         struct net_bridge *br = container_of(work, struct net_bridge,
 333                                              gc_work.work);
 334         unsigned long delay = hold_time(br);
 335         unsigned long work_delay = delay;
 336         unsigned long now = jiffies;
 337         int i;
 338
 339         for (i = 0; i < BR_HASH_SIZE; i++) {
 340                 struct net_bridge_fdb_entry *f;
 341                 struct hlist_node *n;
 342
 343                 if (!br->hash[i].first)
 344                         continue;
 345
 346                 spin_lock_bh(&br->hash_lock);
 347                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 348                         unsigned long this_timer;
 349
 350                         if (f->is_static)
 351                                 continue;
 352                         if (f->added_by_external_learn)
 353                                 continue;
 354                         this_timer = f->updated + delay;
 355                         if (time_after(this_timer, now))
 356                                 work_delay = min(work_delay, this_timer - now);
 357                         else
 358                                 fdb_delete(br, f);
 359                 }
 360                 spin_unlock_bh(&br->hash_lock);
 361                 cond_resched();
 362         }
 363
 364         /* Cleanup minimum 10 milliseconds apart */
 365         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 366         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 367 }
 368
 369 /* Completely flush all dynamic entries in forwarding database.*/
 370 void br_fdb_flush(struct net_bridge *br)
 371 {
 372         int i;
 373
 374         spin_lock_bh(&br->hash_lock);
 375         for (i = 0; i < BR_HASH_SIZE; i++) {
 376                 struct net_bridge_fdb_entry *f;
 377                 struct hlist_node *n;
 378                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 379                         if (!f->is_static)
 380                                 fdb_delete(br, f);
 381                 }
 382         }
 383         spin_unlock_bh(&br->hash_lock);
 384 }
 385
 386 /* Flush all entries referring to a specific port.
 387  * if do_all is set also flush static entries
 388  * if vid is set delete all entries that match the vlan_id
 389  */
 390 void br_fdb_delete_by_port(struct net_bridge *br,
 391                            const struct net_bridge_port *p,
 392                            u16 vid,
 393                            int do_all)
 394 {
 395         int i;
 396
 397         spin_lock_bh(&br->hash_lock);
 398         for (i = 0; i < BR_HASH_SIZE; i++) {
 399                 struct hlist_node *h, *g;
 400
 401                 hlist_for_each_safe(h, g, &br->hash[i]) {
 402                         struct net_bridge_fdb_entry *f
 403                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 404                         if (f->dst != p)
 405                                 continue;
 406
 407                         if (!do_all)
 408                                 if (f->is_static || (vid && f->vlan_id != vid))
 409                                         continue;
 410
 411                         if (f->is_local)
 412                                 fdb_delete_local(br, p, f);
 413                         else
 414                                 fdb_delete(br, f);
 415                 }
 416         }
 417         spin_unlock_bh(&br->hash_lock);
 418 }
 419
 420 #if IS_ENABLED(CONFIG_ATM_LANE)
 421 /* Interface used by ATM LANE hook to test
 422  * if an addr is on some other bridge port */
 423 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 424 {
 425         struct net_bridge_fdb_entry *fdb;
 426         struct net_bridge_port *port;
 427         int ret;
 428
 429         rcu_read_lock();
 430         port = br_port_get_rcu(dev);
 431         if (!port)
 432                 ret = 0;
 433         else {
 434                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 435                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 436                         fdb->dst->state == BR_STATE_FORWARDING;
 437         }
 438         rcu_read_unlock();
 439
 440         return ret;
 441 }
 442 #endif /* CONFIG_ATM_LANE */
 443
 444 /*
 445  * Fill buffer with forwarding table records in
 446  * the API format.
 447  */
 448 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 449                    unsigned long maxnum, unsigned long skip)
 450 {
 451         struct __fdb_entry *fe = buf;
 452         int i, num = 0;
 453         struct net_bridge_fdb_entry *f;
 454
 455         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 456
 457         rcu_read_lock();
 458         for (i = 0; i < BR_HASH_SIZE; i++) {
 459                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 460                         if (num >= maxnum)
 461                                 goto out;
 462
 463                         if (has_expired(br, f))
 464                                 continue;
 465
 466                         /* ignore pseudo entry for local MAC address */
 467                         if (!f->dst)
 468                                 continue;
 469
 470                         if (skip) {
 471                                 --skip;
 472                                 continue;
 473                         }
 474
 475                         /* convert from internal format to API */
 476                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 477
 478                         /* due to ABI compat need to split into hi/lo */
 479                         fe->port_no = f->dst->port_no;
 480                         fe->port_hi = f->dst->port_no >> 8;
 481
 482                         fe->is_local = f->is_local;
 483                         if (!f->is_static)
 484                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 485                         ++fe;
 486                         ++num;
 487                 }
 488         }
 489
 490  out:
 491         rcu_read_unlock();
 492
 493         return num;
 494 }
 495
 496 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 497                                                struct net_bridge_port *source,
 498                                                const unsigned char *addr,
 499                                                __u16 vid,
 500                                                unsigned char is_local,
 501                                                unsigned char is_static)
 502 {
 503         struct net_bridge_fdb_entry *fdb;
 504
 505         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 506         if (fdb) {
 507                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 508                 fdb->dst = source;
 509                 fdb->vlan_id = vid;
 510                 fdb->is_local = is_local;
 511                 fdb->is_static = is_static;
 512                 fdb->added_by_user = 0;
 513                 fdb->added_by_external_learn = 0;
 514                 fdb->updated = fdb->used = jiffies;
 515                 hlist_add_head_rcu(&fdb->hlist, head);
 516         }
 517         return fdb;
 518 }
 519
 520 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 521                   const unsigned char *addr, u16 vid)
 522 {
 523         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 524         struct net_bridge_fdb_entry *fdb;
 525
 526         if (!is_valid_ether_addr(addr))
 527                 return -EINVAL;
 528
 529         fdb = br_fdb_find(br, addr, vid);
 530         if (fdb) {
 531                 /* it is okay to have multiple ports with same
 532                  * address, just use the first one.
 533                  */
 534                 if (fdb->is_local)
 535                         return 0;
 536                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 537                        source ? source->dev->name : br->dev->name, addr, vid);
 538                 fdb_delete(br, fdb);
 539         }
 540
 541         fdb = fdb_create(head, source, addr, vid, 1, 1);
 542         if (!fdb)
 543                 return -ENOMEM;
 544
 545         fdb_add_hw_addr(br, addr);
 546         fdb_notify(br, fdb, RTM_NEWNEIGH);
 547         return 0;
 548 }
 549
 550 /* Add entry for local address of interface */
 551 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 552                   const unsigned char *addr, u16 vid)
 553 {
 554         int ret;
 555
 556         spin_lock_bh(&br->hash_lock);
 557         ret = fdb_insert(br, source, addr, vid);
 558         spin_unlock_bh(&br->hash_lock);
 559         return ret;
 560 }
 561
 562 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 563                    const unsigned char *addr, u16 vid, bool added_by_user)
 564 {
 565         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 566         struct net_bridge_fdb_entry *fdb;
 567         bool fdb_modified = false;
 568
 569         /* some users want to always flood. */
 570         if (hold_time(br) == 0)
 571                 return;
 572
 573         /* ignore packets unless we are using this port */
 574         if (!(source->state == BR_STATE_LEARNING ||
 575               source->state == BR_STATE_FORWARDING))
 576                 return;
 577
 578         fdb = fdb_find_rcu(head, addr, vid);
 579         if (likely(fdb)) {
 580                 /* attempt to update an entry for a local interface */
 581                 if (unlikely(fdb->is_local)) {
 582                         if (net_ratelimit())
 583                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 584                                         source->dev->name, addr, vid);
 585                 } else {
 586                         unsigned long now = jiffies;
 587
 588                         /* fastpath: update of existing entry */
 589                         if (unlikely(source != fdb->dst)) {
 590                                 fdb->dst = source;
 591                                 fdb_modified = true;
 592                                 /* Take over HW learned entry */
 593                                 if (unlikely(fdb->added_by_external_learn))
 594                                         fdb->added_by_external_learn = 0;
 595                         }
 596                         if (now != fdb->updated)
 597                                 fdb->updated = now;
 598                         if (unlikely(added_by_user))
 599                                 fdb->added_by_user = 1;
 600                         if (unlikely(fdb_modified))
 601                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 602                 }
 603         } else {
 604                 spin_lock(&br->hash_lock);
 605                 if (likely(!fdb_find_rcu(head, addr, vid))) {
 606                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 607                         if (fdb) {
 608                                 if (unlikely(added_by_user))
 609                                         fdb->added_by_user = 1;
 610                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 611                         }
 612                 }
 613                 /* else  we lose race and someone else inserts
 614                  * it first, don't bother updating
 615                  */
 616                 spin_unlock(&br->hash_lock);
 617         }
 618 }
 619
 620 static int fdb_to_nud(const struct net_bridge *br,
 621                       const struct net_bridge_fdb_entry *fdb)
 622 {
 623         if (fdb->is_local)
 624                 return NUD_PERMANENT;
 625         else if (fdb->is_static)
 626                 return NUD_NOARP;
 627         else if (has_expired(br, fdb))
 628                 return NUD_STALE;
 629         else
 630                 return NUD_REACHABLE;
 631 }
 632
 633 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 634                          const struct net_bridge_fdb_entry *fdb,
 635                          u32 portid, u32 seq, int type, unsigned int flags)
 636 {
 637         unsigned long now = jiffies;
 638         struct nda_cacheinfo ci;
 639         struct nlmsghdr *nlh;
 640         struct ndmsg *ndm;
 641
 642         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 643         if (nlh == NULL)
 644                 return -EMSGSIZE;
 645
 646         ndm = nlmsg_data(nlh);
 647         ndm->ndm_family  = AF_BRIDGE;
 648         ndm->ndm_pad1    = 0;
 649         ndm->ndm_pad2    = 0;
 650         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 651         ndm->ndm_type    = 0;
 652         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 653         ndm->ndm_state   = fdb_to_nud(br, fdb);
 654
 655         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 656                 goto nla_put_failure;
 657         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 658                 goto nla_put_failure;
 659         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 660         ci.ndm_confirmed = 0;
 661         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 662         ci.ndm_refcnt    = 0;
 663         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 664                 goto nla_put_failure;
 665
 666         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 667                 goto nla_put_failure;
 668
 669         nlmsg_end(skb, nlh);
 670         return 0;
 671
 672 nla_put_failure:
 673         nlmsg_cancel(skb, nlh);
 674         return -EMSGSIZE;
 675 }
 676
 677 static inline size_t fdb_nlmsg_size(void)
 678 {
 679         return NLMSG_ALIGN(sizeof(struct ndmsg))
 680                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 681                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 682                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 683                 + nla_total_size(sizeof(struct nda_cacheinfo));
 684 }
 685
 686 static void fdb_notify(struct net_bridge *br,
 687                        const struct net_bridge_fdb_entry *fdb, int type)
 688 {
 689         struct net *net = dev_net(br->dev);
 690         struct sk_buff *skb;
 691         int err = -ENOBUFS;
 692
 693         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 694         if (skb == NULL)
 695                 goto errout;
 696
 697         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 698         if (err < 0) {
 699                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 700                 WARN_ON(err == -EMSGSIZE);
 701                 kfree_skb(skb);
 702                 goto errout;
 703         }
 704         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 705         return;
 706 errout:
 707         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 708 }
 709
 710 /* Dump information about entries, in response to GETNEIGH */
 711 int br_fdb_dump(struct sk_buff *skb,
 712                 struct netlink_callback *cb,
 713                 struct net_device *dev,
 714                 struct net_device *filter_dev,
 715                 int *idx)
 716 {
 717         struct net_bridge *br = netdev_priv(dev);
 718         int err = 0;
 719         int i;
 720
 721         if (!(dev->priv_flags & IFF_EBRIDGE))
 722                 goto out;
 723
 724         if (!filter_dev) {
 725                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 726                 if (err < 0)
 727                         goto out;
 728         }
 729
 730         for (i = 0; i < BR_HASH_SIZE; i++) {
 731                 struct net_bridge_fdb_entry *f;
 732
 733                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 734
 735                         if (*idx < cb->args[2])
 736                                 goto skip;
 737
 738                         if (filter_dev &&
 739                             (!f->dst || f->dst->dev != filter_dev)) {
 740                                 if (filter_dev != dev)
 741                                         goto skip;
 742                                 /* !f->dst is a special case for bridge
 743                                  * It means the MAC belongs to the bridge
 744                                  * Therefore need a little more filtering
 745                                  * we only want to dump the !f->dst case
 746                                  */
 747                                 if (f->dst)
 748                                         goto skip;
 749                         }
 750                         if (!filter_dev && f->dst)
 751                                 goto skip;
 752
 753                         err = fdb_fill_info(skb, br, f,
 754                                             NETLINK_CB(cb->skb).portid,
 755                                             cb->nlh->nlmsg_seq,
 756                                             RTM_NEWNEIGH,
 757                                             NLM_F_MULTI);
 758                         if (err < 0)
 759                                 goto out;
 760 skip:
 761                         *idx += 1;
 762                 }
 763         }
 764
 765 out:
 766         return err;
 767 }
 768
 769 /* Update (create or replace) forwarding database entry */
 770 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 771                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 772 {
 773         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 774         struct net_bridge_fdb_entry *fdb;
 775         bool modified = false;
 776
 777         /* If the port cannot learn allow only local and static entries */
 778         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 779             !(source->state == BR_STATE_LEARNING ||
 780               source->state == BR_STATE_FORWARDING))
 781                 return -EPERM;
 782
 783         if (!source && !(state & NUD_PERMANENT)) {
 784                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 785                         br->dev->name);
 786                 return -EINVAL;
 787         }
 788
 789         fdb = br_fdb_find(br, addr, vid);
 790         if (fdb == NULL) {
 791                 if (!(flags & NLM_F_CREATE))
 792                         return -ENOENT;
 793
 794                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 795                 if (!fdb)
 796                         return -ENOMEM;
 797
 798                 modified = true;
 799         } else {
 800                 if (flags & NLM_F_EXCL)
 801                         return -EEXIST;
 802
 803                 if (fdb->dst != source) {
 804                         fdb->dst = source;
 805                         modified = true;
 806                 }
 807         }
 808
 809         if (fdb_to_nud(br, fdb) != state) {
 810                 if (state & NUD_PERMANENT) {
 811                         fdb->is_local = 1;
 812                         if (!fdb->is_static) {
 813                                 fdb->is_static = 1;
 814                                 fdb_add_hw_addr(br, addr);
 815                         }
 816                 } else if (state & NUD_NOARP) {
 817                         fdb->is_local = 0;
 818                         if (!fdb->is_static) {
 819                                 fdb->is_static = 1;
 820                                 fdb_add_hw_addr(br, addr);
 821                         }
 822                 } else {
 823                         fdb->is_local = 0;
 824                         if (fdb->is_static) {
 825                                 fdb->is_static = 0;
 826                                 fdb_del_hw_addr(br, addr);
 827                         }
 828                 }
 829
 830                 modified = true;
 831         }
 832         fdb->added_by_user = 1;
 833
 834         fdb->used = jiffies;
 835         if (modified) {
 836                 fdb->updated = jiffies;
 837                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 838         }
 839
 840         return 0;
 841 }
 842
 843 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 844                         struct net_bridge_port *p, const unsigned char *addr,
 845                         u16 nlh_flags, u16 vid)
 846 {
 847         int err = 0;
 848
 849         if (ndm->ndm_flags & NTF_USE) {
 850                 if (!p) {
 851                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 852                                 br->dev->name);
 853                         return -EINVAL;
 854                 }
 855                 local_bh_disable();
 856                 rcu_read_lock();
 857                 br_fdb_update(br, p, addr, vid, true);
 858                 rcu_read_unlock();
 859                 local_bh_enable();
 860         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 861                 err = br_fdb_external_learn_add(br, p, addr, vid);
 862         } else {
 863                 spin_lock_bh(&br->hash_lock);
 864                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 865                                     nlh_flags, vid);
 866                 spin_unlock_bh(&br->hash_lock);
 867         }
 868
 869         return err;
 870 }
 871
 872 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 873 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 874                struct net_device *dev,
 875                const unsigned char *addr, u16 vid, u16 nlh_flags)
 876 {
 877         struct net_bridge_vlan_group *vg;
 878         struct net_bridge_port *p = NULL;
 879         struct net_bridge_vlan *v;
 880         struct net_bridge *br = NULL;
 881         int err = 0;
 882
 883         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 884                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 885                 return -EINVAL;
 886         }
 887
 888         if (is_zero_ether_addr(addr)) {
 889                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 890                 return -EINVAL;
 891         }
 892
 893         if (dev->priv_flags & IFF_EBRIDGE) {
 894                 br = netdev_priv(dev);
 895                 vg = br_vlan_group(br);
 896         } else {
 897                 p = br_port_get_rtnl(dev);
 898                 if (!p) {
 899                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 900                                 dev->name);
 901                         return -EINVAL;
 902                 }
 903                 br = p->br;
 904                 vg = nbp_vlan_group(p);
 905         }
 906
 907         if (vid) {
 908                 v = br_vlan_find(vg, vid);
 909                 if (!v || !br_vlan_should_use(v)) {
 910                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 911                         return -EINVAL;
 912                 }
 913
 914                 /* VID was specified, so use it. */
 915                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 916         } else {
 917                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 918                 if (err || !vg || !vg->num_vlans)
 919                         goto out;
 920
 921                 /* We have vlans configured on this port and user didn't
 922                  * specify a VLAN.  To be nice, add/update entry for every
 923                  * vlan on this port.
 924                  */
 925                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 926                         if (!br_vlan_should_use(v))
 927                                 continue;
 928                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 929                         if (err)
 930                                 goto out;
 931                 }
 932         }
 933
 934 out:
 935         return err;
 936 }
 937
 938 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 939                                        const struct net_bridge_port *p,
 940                                        const u8 *addr, u16 vlan)
 941 {
 942         struct net_bridge_fdb_entry *fdb;
 943
 944         fdb = br_fdb_find(br, addr, vlan);
 945         if (!fdb || fdb->dst != p)
 946                 return -ENOENT;
 947
 948         fdb_delete(br, fdb);
 949
 950         return 0;
 951 }
 952
 953 static int __br_fdb_delete(struct net_bridge *br,
 954                            const struct net_bridge_port *p,
 955                            const unsigned char *addr, u16 vid)
 956 {
 957         int err;
 958
 959         spin_lock_bh(&br->hash_lock);
 960         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 961         spin_unlock_bh(&br->hash_lock);
 962
 963         return err;
 964 }
 965
 966 /* Remove neighbor entry with RTM_DELNEIGH */
 967 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 968                   struct net_device *dev,
 969                   const unsigned char *addr, u16 vid)
 970 {
 971         struct net_bridge_vlan_group *vg;
 972         struct net_bridge_port *p = NULL;
 973         struct net_bridge_vlan *v;
 974         struct net_bridge *br;
 975         int err;
 976
 977         if (dev->priv_flags & IFF_EBRIDGE) {
 978                 br = netdev_priv(dev);
 979                 vg = br_vlan_group(br);
 980         } else {
 981                 p = br_port_get_rtnl(dev);
 982                 if (!p) {
 983                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 984                                 dev->name);
 985                         return -EINVAL;
 986                 }
 987                 vg = nbp_vlan_group(p);
 988                 br = p->br;
 989         }
 990
 991         if (vid) {
 992                 v = br_vlan_find(vg, vid);
 993                 if (!v) {
 994                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 995                         return -EINVAL;
 996                 }
 997
 998                 err = __br_fdb_delete(br, p, addr, vid);
 999         } else {
1000                 err = -ENOENT;
1001                 err &= __br_fdb_delete(br, p, addr, 0);
1002                 if (!vg || !vg->num_vlans)
1003                         return err;
1004
1005                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1006                         if (!br_vlan_should_use(v))
1007                                 continue;
1008                         err &= __br_fdb_delete(br, p, addr, v->vid);
1009                 }
1010         }
1011
1012         return err;
1013 }
1014
1015 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1016 {
1017         struct net_bridge_fdb_entry *fdb, *tmp;
1018         int i;
1019         int err;
1020
1021         ASSERT_RTNL();
1022
1023         for (i = 0; i < BR_HASH_SIZE; i++) {
1024                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1025                         /* We only care for static entries */
1026                         if (!fdb->is_static)
1027                                 continue;
1028
1029                         err = dev_uc_add(p->dev, fdb->addr.addr);
1030                         if (err)
1031                                 goto rollback;
1032                 }
1033         }
1034         return 0;
1035
1036 rollback:
1037         for (i = 0; i < BR_HASH_SIZE; i++) {
1038                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1039                         /* If we reached the fdb that failed, we can stop */
1040                         if (tmp == fdb)
1041                                 break;
1042
1043                         /* We only care for static entries */
1044                         if (!tmp->is_static)
1045                                 continue;
1046
1047                         dev_uc_del(p->dev, tmp->addr.addr);
1048                 }
1049         }
1050         return err;
1051 }
1052
1053 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1054 {
1055         struct net_bridge_fdb_entry *fdb;
1056         int i;
1057
1058         ASSERT_RTNL();
1059
1060         for (i = 0; i < BR_HASH_SIZE; i++) {
1061                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1062                         /* We only care for static entries */
1063                         if (!fdb->is_static)
1064                                 continue;
1065
1066                         dev_uc_del(p->dev, fdb->addr.addr);
1067                 }
1068         }
1069 }
1070
1071 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1072                               const unsigned char *addr, u16 vid)
1073 {
1074         struct hlist_head *head;
1075         struct net_bridge_fdb_entry *fdb;
1076         int err = 0;
1077
1078         ASSERT_RTNL();
1079         spin_lock_bh(&br->hash_lock);
1080
1081         head = &br->hash[br_mac_hash(addr, vid)];
1082         fdb = br_fdb_find(br, addr, vid);
1083         if (!fdb) {
1084                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1085                 if (!fdb) {
1086                         err = -ENOMEM;
1087                         goto err_unlock;
1088                 }
1089                 fdb->added_by_external_learn = 1;
1090                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1091         } else if (fdb->added_by_external_learn) {
1092                 /* Refresh entry */
1093                 fdb->updated = fdb->used = jiffies;
1094         } else if (!fdb->added_by_user) {
1095                 /* Take over SW learned entry */
1096                 fdb->added_by_external_learn = 1;
1097                 fdb->updated = jiffies;
1098                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1099         }
1100
1101 err_unlock:
1102         spin_unlock_bh(&br->hash_lock);
1103
1104         return err;
1105 }
1106
1107 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1108                               const unsigned char *addr, u16 vid)
1109 {
1110         struct net_bridge_fdb_entry *fdb;
1111         int err = 0;
1112
1113         ASSERT_RTNL();
1114         spin_lock_bh(&br->hash_lock);
1115
1116         fdb = br_fdb_find(br, addr, vid);
1117         if (fdb && fdb->added_by_external_learn)
1118                 fdb_delete(br, fdb);
1119         else
1120                 err = -ENOENT;
1121
1122         spin_unlock_bh(&br->hash_lock);
1123
1124         return err;
1125 }