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                         }
 593                         if (now != fdb->updated)
 594                                 fdb->updated = now;
 595                         if (unlikely(added_by_user))
 596                                 fdb->added_by_user = 1;
 597                         if (unlikely(fdb_modified))
 598                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 599                 }
 600         } else {
 601                 spin_lock(&br->hash_lock);
 602                 if (likely(!fdb_find_rcu(head, addr, vid))) {
 603                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 604                         if (fdb) {
 605                                 if (unlikely(added_by_user))
 606                                         fdb->added_by_user = 1;
 607                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 608                         }
 609                 }
 610                 /* else  we lose race and someone else inserts
 611                  * it first, don't bother updating
 612                  */
 613                 spin_unlock(&br->hash_lock);
 614         }
 615 }
 616
 617 static int fdb_to_nud(const struct net_bridge *br,
 618                       const struct net_bridge_fdb_entry *fdb)
 619 {
 620         if (fdb->is_local)
 621                 return NUD_PERMANENT;
 622         else if (fdb->is_static)
 623                 return NUD_NOARP;
 624         else if (has_expired(br, fdb))
 625                 return NUD_STALE;
 626         else
 627                 return NUD_REACHABLE;
 628 }
 629
 630 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 631                          const struct net_bridge_fdb_entry *fdb,
 632                          u32 portid, u32 seq, int type, unsigned int flags)
 633 {
 634         unsigned long now = jiffies;
 635         struct nda_cacheinfo ci;
 636         struct nlmsghdr *nlh;
 637         struct ndmsg *ndm;
 638
 639         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 640         if (nlh == NULL)
 641                 return -EMSGSIZE;
 642
 643         ndm = nlmsg_data(nlh);
 644         ndm->ndm_family  = AF_BRIDGE;
 645         ndm->ndm_pad1    = 0;
 646         ndm->ndm_pad2    = 0;
 647         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 648         ndm->ndm_type    = 0;
 649         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 650         ndm->ndm_state   = fdb_to_nud(br, fdb);
 651
 652         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 653                 goto nla_put_failure;
 654         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 655                 goto nla_put_failure;
 656         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 657         ci.ndm_confirmed = 0;
 658         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 659         ci.ndm_refcnt    = 0;
 660         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 661                 goto nla_put_failure;
 662
 663         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 664                 goto nla_put_failure;
 665
 666         nlmsg_end(skb, nlh);
 667         return 0;
 668
 669 nla_put_failure:
 670         nlmsg_cancel(skb, nlh);
 671         return -EMSGSIZE;
 672 }
 673
 674 static inline size_t fdb_nlmsg_size(void)
 675 {
 676         return NLMSG_ALIGN(sizeof(struct ndmsg))
 677                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 678                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 679                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 680                 + nla_total_size(sizeof(struct nda_cacheinfo));
 681 }
 682
 683 static void fdb_notify(struct net_bridge *br,
 684                        const struct net_bridge_fdb_entry *fdb, int type)
 685 {
 686         struct net *net = dev_net(br->dev);
 687         struct sk_buff *skb;
 688         int err = -ENOBUFS;
 689
 690         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 691         if (skb == NULL)
 692                 goto errout;
 693
 694         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 695         if (err < 0) {
 696                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 697                 WARN_ON(err == -EMSGSIZE);
 698                 kfree_skb(skb);
 699                 goto errout;
 700         }
 701         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 702         return;
 703 errout:
 704         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 705 }
 706
 707 /* Dump information about entries, in response to GETNEIGH */
 708 int br_fdb_dump(struct sk_buff *skb,
 709                 struct netlink_callback *cb,
 710                 struct net_device *dev,
 711                 struct net_device *filter_dev,
 712                 int *idx)
 713 {
 714         struct net_bridge *br = netdev_priv(dev);
 715         int err = 0;
 716         int i;
 717
 718         if (!(dev->priv_flags & IFF_EBRIDGE))
 719                 goto out;
 720
 721         if (!filter_dev) {
 722                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 723                 if (err < 0)
 724                         goto out;
 725         }
 726
 727         for (i = 0; i < BR_HASH_SIZE; i++) {
 728                 struct net_bridge_fdb_entry *f;
 729
 730                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 731
 732                         if (*idx < cb->args[2])
 733                                 goto skip;
 734
 735                         if (filter_dev &&
 736                             (!f->dst || f->dst->dev != filter_dev)) {
 737                                 if (filter_dev != dev)
 738                                         goto skip;
 739                                 /* !f->dst is a special case for bridge
 740                                  * It means the MAC belongs to the bridge
 741                                  * Therefore need a little more filtering
 742                                  * we only want to dump the !f->dst case
 743                                  */
 744                                 if (f->dst)
 745                                         goto skip;
 746                         }
 747                         if (!filter_dev && f->dst)
 748                                 goto skip;
 749
 750                         err = fdb_fill_info(skb, br, f,
 751                                             NETLINK_CB(cb->skb).portid,
 752                                             cb->nlh->nlmsg_seq,
 753                                             RTM_NEWNEIGH,
 754                                             NLM_F_MULTI);
 755                         if (err < 0)
 756                                 goto out;
 757 skip:
 758                         *idx += 1;
 759                 }
 760         }
 761
 762 out:
 763         return err;
 764 }
 765
 766 /* Update (create or replace) forwarding database entry */
 767 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 768                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 769 {
 770         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 771         struct net_bridge_fdb_entry *fdb;
 772         bool modified = false;
 773
 774         /* If the port cannot learn allow only local and static entries */
 775         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 776             !(source->state == BR_STATE_LEARNING ||
 777               source->state == BR_STATE_FORWARDING))
 778                 return -EPERM;
 779
 780         if (!source && !(state & NUD_PERMANENT)) {
 781                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 782                         br->dev->name);
 783                 return -EINVAL;
 784         }
 785
 786         fdb = br_fdb_find(br, addr, vid);
 787         if (fdb == NULL) {
 788                 if (!(flags & NLM_F_CREATE))
 789                         return -ENOENT;
 790
 791                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 792                 if (!fdb)
 793                         return -ENOMEM;
 794
 795                 modified = true;
 796         } else {
 797                 if (flags & NLM_F_EXCL)
 798                         return -EEXIST;
 799
 800                 if (fdb->dst != source) {
 801                         fdb->dst = source;
 802                         modified = true;
 803                 }
 804         }
 805
 806         if (fdb_to_nud(br, fdb) != state) {
 807                 if (state & NUD_PERMANENT) {
 808                         fdb->is_local = 1;
 809                         if (!fdb->is_static) {
 810                                 fdb->is_static = 1;
 811                                 fdb_add_hw_addr(br, addr);
 812                         }
 813                 } else if (state & NUD_NOARP) {
 814                         fdb->is_local = 0;
 815                         if (!fdb->is_static) {
 816                                 fdb->is_static = 1;
 817                                 fdb_add_hw_addr(br, addr);
 818                         }
 819                 } else {
 820                         fdb->is_local = 0;
 821                         if (fdb->is_static) {
 822                                 fdb->is_static = 0;
 823                                 fdb_del_hw_addr(br, addr);
 824                         }
 825                 }
 826
 827                 modified = true;
 828         }
 829         fdb->added_by_user = 1;
 830
 831         fdb->used = jiffies;
 832         if (modified) {
 833                 fdb->updated = jiffies;
 834                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 835         }
 836
 837         return 0;
 838 }
 839
 840 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 841                         struct net_bridge_port *p, const unsigned char *addr,
 842                         u16 nlh_flags, u16 vid)
 843 {
 844         int err = 0;
 845
 846         if (ndm->ndm_flags & NTF_USE) {
 847                 if (!p) {
 848                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 849                                 br->dev->name);
 850                         return -EINVAL;
 851                 }
 852                 local_bh_disable();
 853                 rcu_read_lock();
 854                 br_fdb_update(br, p, addr, vid, true);
 855                 rcu_read_unlock();
 856                 local_bh_enable();
 857         } else {
 858                 spin_lock_bh(&br->hash_lock);
 859                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 860                                     nlh_flags, vid);
 861                 spin_unlock_bh(&br->hash_lock);
 862         }
 863
 864         return err;
 865 }
 866
 867 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 868 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 869                struct net_device *dev,
 870                const unsigned char *addr, u16 vid, u16 nlh_flags)
 871 {
 872         struct net_bridge_vlan_group *vg;
 873         struct net_bridge_port *p = NULL;
 874         struct net_bridge_vlan *v;
 875         struct net_bridge *br = NULL;
 876         int err = 0;
 877
 878         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 879                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 880                 return -EINVAL;
 881         }
 882
 883         if (is_zero_ether_addr(addr)) {
 884                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 885                 return -EINVAL;
 886         }
 887
 888         if (dev->priv_flags & IFF_EBRIDGE) {
 889                 br = netdev_priv(dev);
 890                 vg = br_vlan_group(br);
 891         } else {
 892                 p = br_port_get_rtnl(dev);
 893                 if (!p) {
 894                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 895                                 dev->name);
 896                         return -EINVAL;
 897                 }
 898                 br = p->br;
 899                 vg = nbp_vlan_group(p);
 900         }
 901
 902         if (vid) {
 903                 v = br_vlan_find(vg, vid);
 904                 if (!v || !br_vlan_should_use(v)) {
 905                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 906                         return -EINVAL;
 907                 }
 908
 909                 /* VID was specified, so use it. */
 910                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 911         } else {
 912                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 913                 if (err || !vg || !vg->num_vlans)
 914                         goto out;
 915
 916                 /* We have vlans configured on this port and user didn't
 917                  * specify a VLAN.  To be nice, add/update entry for every
 918                  * vlan on this port.
 919                  */
 920                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 921                         if (!br_vlan_should_use(v))
 922                                 continue;
 923                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 924                         if (err)
 925                                 goto out;
 926                 }
 927         }
 928
 929 out:
 930         return err;
 931 }
 932
 933 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 934                                        const struct net_bridge_port *p,
 935                                        const u8 *addr, u16 vlan)
 936 {
 937         struct net_bridge_fdb_entry *fdb;
 938
 939         fdb = br_fdb_find(br, addr, vlan);
 940         if (!fdb || fdb->dst != p)
 941                 return -ENOENT;
 942
 943         fdb_delete(br, fdb);
 944
 945         return 0;
 946 }
 947
 948 static int __br_fdb_delete(struct net_bridge *br,
 949                            const struct net_bridge_port *p,
 950                            const unsigned char *addr, u16 vid)
 951 {
 952         int err;
 953
 954         spin_lock_bh(&br->hash_lock);
 955         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 956         spin_unlock_bh(&br->hash_lock);
 957
 958         return err;
 959 }
 960
 961 /* Remove neighbor entry with RTM_DELNEIGH */
 962 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 963                   struct net_device *dev,
 964                   const unsigned char *addr, u16 vid)
 965 {
 966         struct net_bridge_vlan_group *vg;
 967         struct net_bridge_port *p = NULL;
 968         struct net_bridge_vlan *v;
 969         struct net_bridge *br;
 970         int err;
 971
 972         if (dev->priv_flags & IFF_EBRIDGE) {
 973                 br = netdev_priv(dev);
 974                 vg = br_vlan_group(br);
 975         } else {
 976                 p = br_port_get_rtnl(dev);
 977                 if (!p) {
 978                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 979                                 dev->name);
 980                         return -EINVAL;
 981                 }
 982                 vg = nbp_vlan_group(p);
 983                 br = p->br;
 984         }
 985
 986         if (vid) {
 987                 v = br_vlan_find(vg, vid);
 988                 if (!v) {
 989                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 990                         return -EINVAL;
 991                 }
 992
 993                 err = __br_fdb_delete(br, p, addr, vid);
 994         } else {
 995                 err = -ENOENT;
 996                 err &= __br_fdb_delete(br, p, addr, 0);
 997                 if (!vg || !vg->num_vlans)
 998                         return err;
 999
1000                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1001                         if (!br_vlan_should_use(v))
1002                                 continue;
1003                         err &= __br_fdb_delete(br, p, addr, v->vid);
1004                 }
1005         }
1006
1007         return err;
1008 }
1009
1010 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1011 {
1012         struct net_bridge_fdb_entry *fdb, *tmp;
1013         int i;
1014         int err;
1015
1016         ASSERT_RTNL();
1017
1018         for (i = 0; i < BR_HASH_SIZE; i++) {
1019                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1020                         /* We only care for static entries */
1021                         if (!fdb->is_static)
1022                                 continue;
1023
1024                         err = dev_uc_add(p->dev, fdb->addr.addr);
1025                         if (err)
1026                                 goto rollback;
1027                 }
1028         }
1029         return 0;
1030
1031 rollback:
1032         for (i = 0; i < BR_HASH_SIZE; i++) {
1033                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1034                         /* If we reached the fdb that failed, we can stop */
1035                         if (tmp == fdb)
1036                                 break;
1037
1038                         /* We only care for static entries */
1039                         if (!tmp->is_static)
1040                                 continue;
1041
1042                         dev_uc_del(p->dev, tmp->addr.addr);
1043                 }
1044         }
1045         return err;
1046 }
1047
1048 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1049 {
1050         struct net_bridge_fdb_entry *fdb;
1051         int i;
1052
1053         ASSERT_RTNL();
1054
1055         for (i = 0; i < BR_HASH_SIZE; i++) {
1056                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1057                         /* We only care for static entries */
1058                         if (!fdb->is_static)
1059                                 continue;
1060
1061                         dev_uc_del(p->dev, fdb->addr.addr);
1062                 }
1063         }
1064 }
1065
1066 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1067                               const unsigned char *addr, u16 vid)
1068 {
1069         struct hlist_head *head;
1070         struct net_bridge_fdb_entry *fdb;
1071         int err = 0;
1072
1073         ASSERT_RTNL();
1074         spin_lock_bh(&br->hash_lock);
1075
1076         head = &br->hash[br_mac_hash(addr, vid)];
1077         fdb = br_fdb_find(br, addr, vid);
1078         if (!fdb) {
1079                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1080                 if (!fdb) {
1081                         err = -ENOMEM;
1082                         goto err_unlock;
1083                 }
1084                 fdb->added_by_external_learn = 1;
1085                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1086         } else if (fdb->added_by_external_learn) {
1087                 /* Refresh entry */
1088                 fdb->updated = fdb->used = jiffies;
1089         } else if (!fdb->added_by_user) {
1090                 /* Take over SW learned entry */
1091                 fdb->added_by_external_learn = 1;
1092                 fdb->updated = jiffies;
1093                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1094         }
1095
1096 err_unlock:
1097         spin_unlock_bh(&br->hash_lock);
1098
1099         return err;
1100 }
1101
1102 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1103                               const unsigned char *addr, u16 vid)
1104 {
1105         struct net_bridge_fdb_entry *fdb;
1106         int err = 0;
1107
1108         ASSERT_RTNL();
1109         spin_lock_bh(&br->hash_lock);
1110
1111         fdb = br_fdb_find(br, addr, vid);
1112         if (fdb && fdb->added_by_external_learn)
1113                 fdb_delete(br, fdb);
1114         else
1115                 err = -ENOENT;
1116
1117         spin_unlock_bh(&br->hash_lock);
1118
1119         return err;
1120 }