net/bridge/br_fdb.c

   1 /*
   2  *      Forwarding database
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/rculist.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/times.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/jhash.h>
  22 #include <linux/random.h>
  23 #include <linux/slab.h>
  24 #include <linux/atomic.h>
  25 #include <asm/unaligned.h>
  26 #include <linux/if_vlan.h>
  27 #include <net/switchdev.h>
  28 #include "br_private.h"
  29
  30 static struct kmem_cache *br_fdb_cache __read_mostly;
  31 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  32                                              const unsigned char *addr,
  33                                              __u16 vid);
  34 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  35                       const unsigned char *addr, u16 vid);
  36 static void fdb_notify(struct net_bridge *br,
  37                        const struct net_bridge_fdb_entry *, int);
  38
  39 static u32 fdb_salt __read_mostly;
  40
  41 int __init br_fdb_init(void)
  42 {
  43         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  44                                          sizeof(struct net_bridge_fdb_entry),
  45                                          0,
  46                                          SLAB_HWCACHE_ALIGN, NULL);
  47         if (!br_fdb_cache)
  48                 return -ENOMEM;
  49
  50         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  51         return 0;
  52 }
  53
  54 void br_fdb_fini(void)
  55 {
  56         kmem_cache_destroy(br_fdb_cache);
  57 }
  58
  59
  60 /* if topology_changing then use forward_delay (default 15 sec)
  61  * otherwise keep longer (default 5 minutes)
  62  */
  63 static inline unsigned long hold_time(const struct net_bridge *br)
  64 {
  65         return br->topology_change ? br->forward_delay : br->ageing_time;
  66 }
  67
  68 static inline int has_expired(const struct net_bridge *br,
  69                                   const struct net_bridge_fdb_entry *fdb)
  70 {
  71         return !fdb->is_static &&
  72                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  73 }
  74
  75 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  76 {
  77         /* use 1 byte of OUI and 3 bytes of NIC */
  78         u32 key = get_unaligned((u32 *)(mac + 2));
  79         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  80 }
  81
  82 static void fdb_rcu_free(struct rcu_head *head)
  83 {
  84         struct net_bridge_fdb_entry *ent
  85                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  86         kmem_cache_free(br_fdb_cache, ent);
  87 }
  88
  89 /* When a static FDB entry is added, the mac address from the entry is
  90  * added to the bridge private HW address list and all required ports
  91  * are then updated with the new information.
  92  * Called under RTNL.
  93  */
  94 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
  95 {
  96         int err;
  97         struct net_bridge_port *p;
  98
  99         ASSERT_RTNL();
 100
 101         list_for_each_entry(p, &br->port_list, list) {
 102                 if (!br_promisc_port(p)) {
 103                         err = dev_uc_add(p->dev, addr);
 104                         if (err)
 105                                 goto undo;
 106                 }
 107         }
 108
 109         return;
 110 undo:
 111         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 112                 if (!br_promisc_port(p))
 113                         dev_uc_del(p->dev, addr);
 114         }
 115 }
 116
 117 /* When a static FDB entry is deleted, the HW address from that entry is
 118  * also removed from the bridge private HW address list and updates all
 119  * the ports with needed information.
 120  * Called under RTNL.
 121  */
 122 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 123 {
 124         struct net_bridge_port *p;
 125
 126         ASSERT_RTNL();
 127
 128         list_for_each_entry(p, &br->port_list, list) {
 129                 if (!br_promisc_port(p))
 130                         dev_uc_del(p->dev, addr);
 131         }
 132 }
 133
 134 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 135 {
 136         struct switchdev_obj_port_fdb fdb = {
 137                 .obj = {
 138                         .orig_dev = f->dst->dev,
 139                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 140                         .flags = SWITCHDEV_F_DEFER,
 141                 },
 142                 .vid = f->vlan_id,
 143         };
 144
 145         ether_addr_copy(fdb.addr, f->addr.addr);
 146         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 147 }
 148
 149 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 150 {
 151         if (f->is_static)
 152                 fdb_del_hw_addr(br, f->addr.addr);
 153
 154         if (f->added_by_external_learn)
 155                 fdb_del_external_learn(f);
 156
 157         hlist_del_rcu(&f->hlist);
 158         fdb_notify(br, f, RTM_DELNEIGH);
 159         call_rcu(&f->rcu, fdb_rcu_free);
 160 }
 161
 162 /* Delete a local entry if no other port had the same address. */
 163 static void fdb_delete_local(struct net_bridge *br,
 164                              const struct net_bridge_port *p,
 165                              struct net_bridge_fdb_entry *f)
 166 {
 167         const unsigned char *addr = f->addr.addr;
 168         struct net_bridge_vlan_group *vg;
 169         const struct net_bridge_vlan *v;
 170         struct net_bridge_port *op;
 171         u16 vid = f->vlan_id;
 172
 173         /* Maybe another port has same hw addr? */
 174         list_for_each_entry(op, &br->port_list, list) {
 175                 vg = nbp_vlan_group(op);
 176                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 177                     (!vid || br_vlan_find(vg, vid))) {
 178                         f->dst = op;
 179                         f->added_by_user = 0;
 180                         return;
 181                 }
 182         }
 183
 184         vg = br_vlan_group(br);
 185         v = br_vlan_find(vg, vid);
 186         /* Maybe bridge device has same hw addr? */
 187         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 188             (!vid || (v && br_vlan_should_use(v)))) {
 189                 f->dst = NULL;
 190                 f->added_by_user = 0;
 191                 return;
 192         }
 193
 194         fdb_delete(br, f);
 195 }
 196
 197 void br_fdb_find_delete_local(struct net_bridge *br,
 198                               const struct net_bridge_port *p,
 199                               const unsigned char *addr, u16 vid)
 200 {
 201         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 202         struct net_bridge_fdb_entry *f;
 203
 204         spin_lock_bh(&br->hash_lock);
 205         f = fdb_find(head, addr, vid);
 206         if (f && f->is_local && !f->added_by_user && f->dst == p)
 207                 fdb_delete_local(br, p, f);
 208         spin_unlock_bh(&br->hash_lock);
 209 }
 210
 211 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 212 {
 213         struct net_bridge_vlan_group *vg;
 214         struct net_bridge *br = p->br;
 215         struct net_bridge_vlan *v;
 216         int i;
 217
 218         spin_lock_bh(&br->hash_lock);
 219
 220         vg = nbp_vlan_group(p);
 221         /* Search all chains since old address/hash is unknown */
 222         for (i = 0; i < BR_HASH_SIZE; i++) {
 223                 struct hlist_node *h;
 224                 hlist_for_each(h, &br->hash[i]) {
 225                         struct net_bridge_fdb_entry *f;
 226
 227                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 228                         if (f->dst == p && f->is_local && !f->added_by_user) {
 229                                 /* delete old one */
 230                                 fdb_delete_local(br, p, f);
 231
 232                                 /* if this port has no vlan information
 233                                  * configured, we can safely be done at
 234                                  * this point.
 235                                  */
 236                                 if (!vg || !vg->num_vlans)
 237                                         goto insert;
 238                         }
 239                 }
 240         }
 241
 242 insert:
 243         /* insert new address,  may fail if invalid address or dup. */
 244         fdb_insert(br, p, newaddr, 0);
 245
 246         if (!vg || !vg->num_vlans)
 247                 goto done;
 248
 249         /* Now add entries for every VLAN configured on the port.
 250          * This function runs under RTNL so the bitmap will not change
 251          * from under us.
 252          */
 253         list_for_each_entry(v, &vg->vlan_list, vlist)
 254                 fdb_insert(br, p, newaddr, v->vid);
 255
 256 done:
 257         spin_unlock_bh(&br->hash_lock);
 258 }
 259
 260 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 261 {
 262         struct net_bridge_vlan_group *vg;
 263         struct net_bridge_fdb_entry *f;
 264         struct net_bridge_vlan *v;
 265
 266         spin_lock_bh(&br->hash_lock);
 267
 268         /* If old entry was unassociated with any port, then delete it. */
 269         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 270         if (f && f->is_local && !f->dst)
 271                 fdb_delete_local(br, NULL, f);
 272
 273         fdb_insert(br, NULL, newaddr, 0);
 274         vg = br_vlan_group(br);
 275         if (!vg || !vg->num_vlans)
 276                 goto out;
 277         /* Now remove and add entries for every VLAN configured on the
 278          * bridge.  This function runs under RTNL so the bitmap will not
 279          * change from under us.
 280          */
 281         list_for_each_entry(v, &vg->vlan_list, vlist) {
 282                 f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 283                 if (f && f->is_local && !f->dst)
 284                         fdb_delete_local(br, NULL, f);
 285                 fdb_insert(br, NULL, newaddr, v->vid);
 286         }
 287 out:
 288         spin_unlock_bh(&br->hash_lock);
 289 }
 290
 291 void br_fdb_cleanup(unsigned long _data)
 292 {
 293         struct net_bridge *br = (struct net_bridge *)_data;
 294         unsigned long delay = hold_time(br);
 295         unsigned long next_timer = jiffies + br->ageing_time;
 296         int i;
 297
 298         spin_lock(&br->hash_lock);
 299         for (i = 0; i < BR_HASH_SIZE; i++) {
 300                 struct net_bridge_fdb_entry *f;
 301                 struct hlist_node *n;
 302
 303                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 304                         unsigned long this_timer;
 305                         if (f->is_static)
 306                                 continue;
 307                         if (f->added_by_external_learn)
 308                                 continue;
 309                         this_timer = f->updated + delay;
 310                         if (time_before_eq(this_timer, jiffies))
 311                                 fdb_delete(br, f);
 312                         else if (time_before(this_timer, next_timer))
 313                                 next_timer = this_timer;
 314                 }
 315         }
 316         spin_unlock(&br->hash_lock);
 317
 318         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 319 }
 320
 321 /* Completely flush all dynamic entries in forwarding database.*/
 322 void br_fdb_flush(struct net_bridge *br)
 323 {
 324         int i;
 325
 326         spin_lock_bh(&br->hash_lock);
 327         for (i = 0; i < BR_HASH_SIZE; i++) {
 328                 struct net_bridge_fdb_entry *f;
 329                 struct hlist_node *n;
 330                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 331                         if (!f->is_static)
 332                                 fdb_delete(br, f);
 333                 }
 334         }
 335         spin_unlock_bh(&br->hash_lock);
 336 }
 337
 338 /* Flush all entries referring to a specific port.
 339  * if do_all is set also flush static entries
 340  * if vid is set delete all entries that match the vlan_id
 341  */
 342 void br_fdb_delete_by_port(struct net_bridge *br,
 343                            const struct net_bridge_port *p,
 344                            u16 vid,
 345                            int do_all)
 346 {
 347         int i;
 348
 349         spin_lock_bh(&br->hash_lock);
 350         for (i = 0; i < BR_HASH_SIZE; i++) {
 351                 struct hlist_node *h, *g;
 352
 353                 hlist_for_each_safe(h, g, &br->hash[i]) {
 354                         struct net_bridge_fdb_entry *f
 355                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 356                         if (f->dst != p)
 357                                 continue;
 358
 359                         if (!do_all)
 360                                 if (f->is_static || (vid && f->vlan_id != vid))
 361                                         continue;
 362
 363                         if (f->is_local)
 364                                 fdb_delete_local(br, p, f);
 365                         else
 366                                 fdb_delete(br, f);
 367                 }
 368         }
 369         spin_unlock_bh(&br->hash_lock);
 370 }
 371
 372 /* No locking or refcounting, assumes caller has rcu_read_lock */
 373 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 374                                           const unsigned char *addr,
 375                                           __u16 vid)
 376 {
 377         struct net_bridge_fdb_entry *fdb;
 378
 379         hlist_for_each_entry_rcu(fdb,
 380                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 381                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 382                     fdb->vlan_id == vid) {
 383                         if (unlikely(has_expired(br, fdb)))
 384                                 break;
 385                         return fdb;
 386                 }
 387         }
 388
 389         return NULL;
 390 }
 391
 392 #if IS_ENABLED(CONFIG_ATM_LANE)
 393 /* Interface used by ATM LANE hook to test
 394  * if an addr is on some other bridge port */
 395 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 396 {
 397         struct net_bridge_fdb_entry *fdb;
 398         struct net_bridge_port *port;
 399         int ret;
 400
 401         rcu_read_lock();
 402         port = br_port_get_rcu(dev);
 403         if (!port)
 404                 ret = 0;
 405         else {
 406                 fdb = __br_fdb_get(port->br, addr, 0);
 407                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 408                         fdb->dst->state == BR_STATE_FORWARDING;
 409         }
 410         rcu_read_unlock();
 411
 412         return ret;
 413 }
 414 #endif /* CONFIG_ATM_LANE */
 415
 416 /*
 417  * Fill buffer with forwarding table records in
 418  * the API format.
 419  */
 420 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 421                    unsigned long maxnum, unsigned long skip)
 422 {
 423         struct __fdb_entry *fe = buf;
 424         int i, num = 0;
 425         struct net_bridge_fdb_entry *f;
 426
 427         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 428
 429         rcu_read_lock();
 430         for (i = 0; i < BR_HASH_SIZE; i++) {
 431                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 432                         if (num >= maxnum)
 433                                 goto out;
 434
 435                         if (has_expired(br, f))
 436                                 continue;
 437
 438                         /* ignore pseudo entry for local MAC address */
 439                         if (!f->dst)
 440                                 continue;
 441
 442                         if (skip) {
 443                                 --skip;
 444                                 continue;
 445                         }
 446
 447                         /* convert from internal format to API */
 448                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 449
 450                         /* due to ABI compat need to split into hi/lo */
 451                         fe->port_no = f->dst->port_no;
 452                         fe->port_hi = f->dst->port_no >> 8;
 453
 454                         fe->is_local = f->is_local;
 455                         if (!f->is_static)
 456                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 457                         ++fe;
 458                         ++num;
 459                 }
 460         }
 461
 462  out:
 463         rcu_read_unlock();
 464
 465         return num;
 466 }
 467
 468 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 469                                              const unsigned char *addr,
 470                                              __u16 vid)
 471 {
 472         struct net_bridge_fdb_entry *fdb;
 473
 474         hlist_for_each_entry(fdb, head, hlist) {
 475                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 476                     fdb->vlan_id == vid)
 477                         return fdb;
 478         }
 479         return NULL;
 480 }
 481
 482 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 483                                                  const unsigned char *addr,
 484                                                  __u16 vid)
 485 {
 486         struct net_bridge_fdb_entry *fdb;
 487
 488         hlist_for_each_entry_rcu(fdb, head, hlist) {
 489                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 490                     fdb->vlan_id == vid)
 491                         return fdb;
 492         }
 493         return NULL;
 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 = fdb_find(head, 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 "
 537                        "as a received packet\n",
 538                        source ? source->dev->name : br->dev->name);
 539                 fdb_delete(br, fdb);
 540         }
 541
 542         fdb = fdb_create(head, source, addr, vid, 1, 1);
 543         if (!fdb)
 544                 return -ENOMEM;
 545
 546         fdb_add_hw_addr(br, addr);
 547         fdb_notify(br, fdb, RTM_NEWNEIGH);
 548         return 0;
 549 }
 550
 551 /* Add entry for local address of interface */
 552 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 553                   const unsigned char *addr, u16 vid)
 554 {
 555         int ret;
 556
 557         spin_lock_bh(&br->hash_lock);
 558         ret = fdb_insert(br, source, addr, vid);
 559         spin_unlock_bh(&br->hash_lock);
 560         return ret;
 561 }
 562
 563 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 564                    const unsigned char *addr, u16 vid, bool added_by_user)
 565 {
 566         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 567         struct net_bridge_fdb_entry *fdb;
 568         bool fdb_modified = false;
 569
 570         /* some users want to always flood. */
 571         if (hold_time(br) == 0)
 572                 return;
 573
 574         /* ignore packets unless we are using this port */
 575         if (!(source->state == BR_STATE_LEARNING ||
 576               source->state == BR_STATE_FORWARDING))
 577                 return;
 578
 579         fdb = fdb_find_rcu(head, addr, vid);
 580         if (likely(fdb)) {
 581                 /* attempt to update an entry for a local interface */
 582                 if (unlikely(fdb->is_local)) {
 583                         if (net_ratelimit())
 584                                 br_warn(br, "received packet on %s with "
 585                                         "own address as source address\n",
 586                                         source->dev->name);
 587                 } else {
 588                         /* fastpath: update of existing entry */
 589                         if (unlikely(source != fdb->dst)) {
 590                                 fdb->dst = source;
 591                                 fdb_modified = true;
 592                         }
 593                         fdb->updated = jiffies;
 594                         if (unlikely(added_by_user))
 595                                 fdb->added_by_user = 1;
 596                         if (unlikely(fdb_modified))
 597                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 598                 }
 599         } else {
 600                 spin_lock(&br->hash_lock);
 601                 if (likely(!fdb_find(head, addr, vid))) {
 602                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 603                         if (fdb) {
 604                                 if (unlikely(added_by_user))
 605                                         fdb->added_by_user = 1;
 606                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 607                         }
 608                 }
 609                 /* else  we lose race and someone else inserts
 610                  * it first, don't bother updating
 611                  */
 612                 spin_unlock(&br->hash_lock);
 613         }
 614 }
 615
 616 static int fdb_to_nud(const struct net_bridge *br,
 617                       const struct net_bridge_fdb_entry *fdb)
 618 {
 619         if (fdb->is_local)
 620                 return NUD_PERMANENT;
 621         else if (fdb->is_static)
 622                 return NUD_NOARP;
 623         else if (has_expired(br, fdb))
 624                 return NUD_STALE;
 625         else
 626                 return NUD_REACHABLE;
 627 }
 628
 629 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 630                          const struct net_bridge_fdb_entry *fdb,
 631                          u32 portid, u32 seq, int type, unsigned int flags)
 632 {
 633         unsigned long now = jiffies;
 634         struct nda_cacheinfo ci;
 635         struct nlmsghdr *nlh;
 636         struct ndmsg *ndm;
 637
 638         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 639         if (nlh == NULL)
 640                 return -EMSGSIZE;
 641
 642         ndm = nlmsg_data(nlh);
 643         ndm->ndm_family  = AF_BRIDGE;
 644         ndm->ndm_pad1    = 0;
 645         ndm->ndm_pad2    = 0;
 646         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 647         ndm->ndm_type    = 0;
 648         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 649         ndm->ndm_state   = fdb_to_nud(br, fdb);
 650
 651         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 652                 goto nla_put_failure;
 653         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 654                 goto nla_put_failure;
 655         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 656         ci.ndm_confirmed = 0;
 657         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 658         ci.ndm_refcnt    = 0;
 659         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 660                 goto nla_put_failure;
 661
 662         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 663                 goto nla_put_failure;
 664
 665         nlmsg_end(skb, nlh);
 666         return 0;
 667
 668 nla_put_failure:
 669         nlmsg_cancel(skb, nlh);
 670         return -EMSGSIZE;
 671 }
 672
 673 static inline size_t fdb_nlmsg_size(void)
 674 {
 675         return NLMSG_ALIGN(sizeof(struct ndmsg))
 676                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 677                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 678                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 679                 + nla_total_size(sizeof(struct nda_cacheinfo));
 680 }
 681
 682 static void fdb_notify(struct net_bridge *br,
 683                        const struct net_bridge_fdb_entry *fdb, int type)
 684 {
 685         struct net *net = dev_net(br->dev);
 686         struct sk_buff *skb;
 687         int err = -ENOBUFS;
 688
 689         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 690         if (skb == NULL)
 691                 goto errout;
 692
 693         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 694         if (err < 0) {
 695                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 696                 WARN_ON(err == -EMSGSIZE);
 697                 kfree_skb(skb);
 698                 goto errout;
 699         }
 700         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 701         return;
 702 errout:
 703         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 704 }
 705
 706 /* Dump information about entries, in response to GETNEIGH */
 707 int br_fdb_dump(struct sk_buff *skb,
 708                 struct netlink_callback *cb,
 709                 struct net_device *dev,
 710                 struct net_device *filter_dev,
 711                 int idx)
 712 {
 713         struct net_bridge *br = netdev_priv(dev);
 714         int i;
 715
 716         if (!(dev->priv_flags & IFF_EBRIDGE))
 717                 goto out;
 718
 719         if (!filter_dev)
 720                 idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 721
 722         for (i = 0; i < BR_HASH_SIZE; i++) {
 723                 struct net_bridge_fdb_entry *f;
 724
 725                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 726                         if (idx < cb->args[0])
 727                                 goto skip;
 728
 729                         if (filter_dev &&
 730                             (!f->dst || f->dst->dev != filter_dev)) {
 731                                 if (filter_dev != dev)
 732                                         goto skip;
 733                                 /* !f->dst is a special case for bridge
 734                                  * It means the MAC belongs to the bridge
 735                                  * Therefore need a little more filtering
 736                                  * we only want to dump the !f->dst case
 737                                  */
 738                                 if (f->dst)
 739                                         goto skip;
 740                         }
 741                         if (!filter_dev && f->dst)
 742                                 goto skip;
 743
 744                         if (fdb_fill_info(skb, br, f,
 745                                           NETLINK_CB(cb->skb).portid,
 746                                           cb->nlh->nlmsg_seq,
 747                                           RTM_NEWNEIGH,
 748                                           NLM_F_MULTI) < 0)
 749                                 break;
 750 skip:
 751                         ++idx;
 752                 }
 753         }
 754
 755 out:
 756         return idx;
 757 }
 758
 759 /* Update (create or replace) forwarding database entry */
 760 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 761                          __u16 state, __u16 flags, __u16 vid)
 762 {
 763         struct net_bridge *br = source->br;
 764         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 765         struct net_bridge_fdb_entry *fdb;
 766         bool modified = false;
 767
 768         /* If the port cannot learn allow only local and static entries */
 769         if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 770             !(source->state == BR_STATE_LEARNING ||
 771               source->state == BR_STATE_FORWARDING))
 772                 return -EPERM;
 773
 774         fdb = fdb_find(head, addr, vid);
 775         if (fdb == NULL) {
 776                 if (!(flags & NLM_F_CREATE))
 777                         return -ENOENT;
 778
 779                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 780                 if (!fdb)
 781                         return -ENOMEM;
 782
 783                 modified = true;
 784         } else {
 785                 if (flags & NLM_F_EXCL)
 786                         return -EEXIST;
 787
 788                 if (fdb->dst != source) {
 789                         fdb->dst = source;
 790                         modified = true;
 791                 }
 792         }
 793
 794         if (fdb_to_nud(br, fdb) != state) {
 795                 if (state & NUD_PERMANENT) {
 796                         fdb->is_local = 1;
 797                         if (!fdb->is_static) {
 798                                 fdb->is_static = 1;
 799                                 fdb_add_hw_addr(br, addr);
 800                         }
 801                 } else if (state & NUD_NOARP) {
 802                         fdb->is_local = 0;
 803                         if (!fdb->is_static) {
 804                                 fdb->is_static = 1;
 805                                 fdb_add_hw_addr(br, addr);
 806                         }
 807                 } else {
 808                         fdb->is_local = 0;
 809                         if (fdb->is_static) {
 810                                 fdb->is_static = 0;
 811                                 fdb_del_hw_addr(br, addr);
 812                         }
 813                 }
 814
 815                 modified = true;
 816         }
 817         fdb->added_by_user = 1;
 818
 819         fdb->used = jiffies;
 820         if (modified) {
 821                 fdb->updated = jiffies;
 822                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 823         }
 824
 825         return 0;
 826 }
 827
 828 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 829                const unsigned char *addr, u16 nlh_flags, u16 vid)
 830 {
 831         int err = 0;
 832
 833         if (ndm->ndm_flags & NTF_USE) {
 834                 local_bh_disable();
 835                 rcu_read_lock();
 836                 br_fdb_update(p->br, p, addr, vid, true);
 837                 rcu_read_unlock();
 838                 local_bh_enable();
 839         } else {
 840                 spin_lock_bh(&p->br->hash_lock);
 841                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 842                                     nlh_flags, vid);
 843                 spin_unlock_bh(&p->br->hash_lock);
 844         }
 845
 846         return err;
 847 }
 848
 849 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 850 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 851                struct net_device *dev,
 852                const unsigned char *addr, u16 vid, u16 nlh_flags)
 853 {
 854         struct net_bridge_vlan_group *vg;
 855         struct net_bridge_port *p = NULL;
 856         struct net_bridge_vlan *v;
 857         struct net_bridge *br = NULL;
 858         int err = 0;
 859
 860         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 861                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 862                 return -EINVAL;
 863         }
 864
 865         if (is_zero_ether_addr(addr)) {
 866                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 867                 return -EINVAL;
 868         }
 869
 870         if (dev->priv_flags & IFF_EBRIDGE) {
 871                 br = netdev_priv(dev);
 872                 vg = br_vlan_group(br);
 873         } else {
 874                 p = br_port_get_rtnl(dev);
 875                 if (!p) {
 876                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 877                                 dev->name);
 878                         return -EINVAL;
 879                 }
 880                 vg = nbp_vlan_group(p);
 881         }
 882
 883         if (vid) {
 884                 v = br_vlan_find(vg, vid);
 885                 if (!v || !br_vlan_should_use(v)) {
 886                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 887                         return -EINVAL;
 888                 }
 889
 890                 /* VID was specified, so use it. */
 891                 if (dev->priv_flags & IFF_EBRIDGE)
 892                         err = br_fdb_insert(br, NULL, addr, vid);
 893                 else
 894                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 895         } else {
 896                 if (dev->priv_flags & IFF_EBRIDGE)
 897                         err = br_fdb_insert(br, NULL, addr, 0);
 898                 else
 899                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 900                 if (err || !vg || !vg->num_vlans)
 901                         goto out;
 902
 903                 /* We have vlans configured on this port and user didn't
 904                  * specify a VLAN.  To be nice, add/update entry for every
 905                  * vlan on this port.
 906                  */
 907                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 908                         if (!br_vlan_should_use(v))
 909                                 continue;
 910                         if (dev->priv_flags & IFF_EBRIDGE)
 911                                 err = br_fdb_insert(br, NULL, addr, v->vid);
 912                         else
 913                                 err = __br_fdb_add(ndm, p, addr, nlh_flags,
 914                                                    v->vid);
 915                         if (err)
 916                                 goto out;
 917                 }
 918         }
 919
 920 out:
 921         return err;
 922 }
 923
 924 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 925                               u16 vid)
 926 {
 927         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 928         struct net_bridge_fdb_entry *fdb;
 929
 930         fdb = fdb_find(head, addr, vid);
 931         if (!fdb)
 932                 return -ENOENT;
 933
 934         fdb_delete(br, fdb);
 935         return 0;
 936 }
 937
 938 static int __br_fdb_delete_by_addr(struct net_bridge *br,
 939                                    const unsigned char *addr, u16 vid)
 940 {
 941         int err;
 942
 943         spin_lock_bh(&br->hash_lock);
 944         err = fdb_delete_by_addr(br, addr, vid);
 945         spin_unlock_bh(&br->hash_lock);
 946
 947         return err;
 948 }
 949
 950 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 951                                        const u8 *addr, u16 vlan)
 952 {
 953         struct net_bridge *br = p->br;
 954         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 955         struct net_bridge_fdb_entry *fdb;
 956
 957         fdb = fdb_find(head, addr, vlan);
 958         if (!fdb || fdb->dst != p)
 959                 return -ENOENT;
 960
 961         fdb_delete(br, fdb);
 962         return 0;
 963 }
 964
 965 static int __br_fdb_delete(struct net_bridge_port *p,
 966                            const unsigned char *addr, u16 vid)
 967 {
 968         int err;
 969
 970         spin_lock_bh(&p->br->hash_lock);
 971         err = fdb_delete_by_addr_and_port(p, addr, vid);
 972         spin_unlock_bh(&p->br->hash_lock);
 973
 974         return err;
 975 }
 976
 977 /* Remove neighbor entry with RTM_DELNEIGH */
 978 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 979                   struct net_device *dev,
 980                   const unsigned char *addr, u16 vid)
 981 {
 982         struct net_bridge_vlan_group *vg;
 983         struct net_bridge_port *p = NULL;
 984         struct net_bridge_vlan *v;
 985         struct net_bridge *br = NULL;
 986         int err;
 987
 988         if (dev->priv_flags & IFF_EBRIDGE) {
 989                 br = netdev_priv(dev);
 990                 vg = br_vlan_group(br);
 991         } else {
 992                 p = br_port_get_rtnl(dev);
 993                 if (!p) {
 994                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 995                                 dev->name);
 996                         return -EINVAL;
 997                 }
 998                 vg = nbp_vlan_group(p);
 999         }
1000
1001         if (vid) {
1002                 v = br_vlan_find(vg, vid);
1003                 if (!v) {
1004                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1005                         return -EINVAL;
1006                 }
1007
1008                 if (dev->priv_flags & IFF_EBRIDGE)
1009                         err = __br_fdb_delete_by_addr(br, addr, vid);
1010                 else
1011                         err = __br_fdb_delete(p, addr, vid);
1012         } else {
1013                 err = -ENOENT;
1014                 if (dev->priv_flags & IFF_EBRIDGE)
1015                         err = __br_fdb_delete_by_addr(br, addr, 0);
1016                 else
1017                         err &= __br_fdb_delete(p, addr, 0);
1018
1019                 if (!vg || !vg->num_vlans)
1020                         goto out;
1021
1022                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1023                         if (!br_vlan_should_use(v))
1024                                 continue;
1025                         if (dev->priv_flags & IFF_EBRIDGE)
1026                                 err = __br_fdb_delete_by_addr(br, addr, v->vid);
1027                         else
1028                                 err &= __br_fdb_delete(p, addr, v->vid);
1029                 }
1030         }
1031 out:
1032         return err;
1033 }
1034
1035 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1036 {
1037         struct net_bridge_fdb_entry *fdb, *tmp;
1038         int i;
1039         int err;
1040
1041         ASSERT_RTNL();
1042
1043         for (i = 0; i < BR_HASH_SIZE; i++) {
1044                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1045                         /* We only care for static entries */
1046                         if (!fdb->is_static)
1047                                 continue;
1048
1049                         err = dev_uc_add(p->dev, fdb->addr.addr);
1050                         if (err)
1051                                 goto rollback;
1052                 }
1053         }
1054         return 0;
1055
1056 rollback:
1057         for (i = 0; i < BR_HASH_SIZE; i++) {
1058                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1059                         /* If we reached the fdb that failed, we can stop */
1060                         if (tmp == fdb)
1061                                 break;
1062
1063                         /* We only care for static entries */
1064                         if (!tmp->is_static)
1065                                 continue;
1066
1067                         dev_uc_del(p->dev, tmp->addr.addr);
1068                 }
1069         }
1070         return err;
1071 }
1072
1073 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1074 {
1075         struct net_bridge_fdb_entry *fdb;
1076         int i;
1077
1078         ASSERT_RTNL();
1079
1080         for (i = 0; i < BR_HASH_SIZE; i++) {
1081                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1082                         /* We only care for static entries */
1083                         if (!fdb->is_static)
1084                                 continue;
1085
1086                         dev_uc_del(p->dev, fdb->addr.addr);
1087                 }
1088         }
1089 }
1090
1091 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1092                               const unsigned char *addr, u16 vid)
1093 {
1094         struct hlist_head *head;
1095         struct net_bridge_fdb_entry *fdb;
1096         int err = 0;
1097
1098         ASSERT_RTNL();
1099         spin_lock_bh(&br->hash_lock);
1100
1101         head = &br->hash[br_mac_hash(addr, vid)];
1102         fdb = fdb_find(head, addr, vid);
1103         if (!fdb) {
1104                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1105                 if (!fdb) {
1106                         err = -ENOMEM;
1107                         goto err_unlock;
1108                 }
1109                 fdb->added_by_external_learn = 1;
1110                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1111         } else if (fdb->added_by_external_learn) {
1112                 /* Refresh entry */
1113                 fdb->updated = fdb->used = jiffies;
1114         } else if (!fdb->added_by_user) {
1115                 /* Take over SW learned entry */
1116                 fdb->added_by_external_learn = 1;
1117                 fdb->updated = jiffies;
1118                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1119         }
1120
1121 err_unlock:
1122         spin_unlock_bh(&br->hash_lock);
1123
1124         return err;
1125 }
1126
1127 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1128                               const unsigned char *addr, u16 vid)
1129 {
1130         struct hlist_head *head;
1131         struct net_bridge_fdb_entry *fdb;
1132         int err = 0;
1133
1134         ASSERT_RTNL();
1135         spin_lock_bh(&br->hash_lock);
1136
1137         head = &br->hash[br_mac_hash(addr, vid)];
1138         fdb = fdb_find(head, addr, vid);
1139         if (fdb && fdb->added_by_external_learn)
1140                 fdb_delete(br, fdb);
1141         else
1142                 err = -ENOENT;
1143
1144         spin_unlock_bh(&br->hash_lock);
1145
1146         return err;
1147 }