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                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 139                         .flags = SWITCHDEV_F_DEFER,
 140                 },
 141                 .vid = f->vlan_id,
 142         };
 143
 144         ether_addr_copy(fdb.addr, f->addr.addr);
 145         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 146 }
 147
 148 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 149 {
 150         if (f->is_static)
 151                 fdb_del_hw_addr(br, f->addr.addr);
 152
 153         if (f->added_by_external_learn)
 154                 fdb_del_external_learn(f);
 155
 156         hlist_del_rcu(&f->hlist);
 157         fdb_notify(br, f, RTM_DELNEIGH);
 158         call_rcu(&f->rcu, fdb_rcu_free);
 159 }
 160
 161 /* Delete a local entry if no other port had the same address. */
 162 static void fdb_delete_local(struct net_bridge *br,
 163                              const struct net_bridge_port *p,
 164                              struct net_bridge_fdb_entry *f)
 165 {
 166         const unsigned char *addr = f->addr.addr;
 167         struct net_bridge_vlan_group *vg;
 168         const struct net_bridge_vlan *v;
 169         struct net_bridge_port *op;
 170         u16 vid = f->vlan_id;
 171
 172         /* Maybe another port has same hw addr? */
 173         list_for_each_entry(op, &br->port_list, list) {
 174                 vg = nbp_vlan_group(op);
 175                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 176                     (!vid || br_vlan_find(vg, vid))) {
 177                         f->dst = op;
 178                         f->added_by_user = 0;
 179                         return;
 180                 }
 181         }
 182
 183         vg = br_vlan_group(br);
 184         v = br_vlan_find(vg, vid);
 185         /* Maybe bridge device has same hw addr? */
 186         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 187             (!vid || (v && br_vlan_should_use(v)))) {
 188                 f->dst = NULL;
 189                 f->added_by_user = 0;
 190                 return;
 191         }
 192
 193         fdb_delete(br, f);
 194 }
 195
 196 void br_fdb_find_delete_local(struct net_bridge *br,
 197                               const struct net_bridge_port *p,
 198                               const unsigned char *addr, u16 vid)
 199 {
 200         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 201         struct net_bridge_fdb_entry *f;
 202
 203         spin_lock_bh(&br->hash_lock);
 204         f = fdb_find(head, addr, vid);
 205         if (f && f->is_local && !f->added_by_user && f->dst == p)
 206                 fdb_delete_local(br, p, f);
 207         spin_unlock_bh(&br->hash_lock);
 208 }
 209
 210 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 211 {
 212         struct net_bridge_vlan_group *vg;
 213         struct net_bridge *br = p->br;
 214         struct net_bridge_vlan *v;
 215         int i;
 216
 217         spin_lock_bh(&br->hash_lock);
 218
 219         vg = nbp_vlan_group(p);
 220         /* Search all chains since old address/hash is unknown */
 221         for (i = 0; i < BR_HASH_SIZE; i++) {
 222                 struct hlist_node *h;
 223                 hlist_for_each(h, &br->hash[i]) {
 224                         struct net_bridge_fdb_entry *f;
 225
 226                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 227                         if (f->dst == p && f->is_local && !f->added_by_user) {
 228                                 /* delete old one */
 229                                 fdb_delete_local(br, p, f);
 230
 231                                 /* if this port has no vlan information
 232                                  * configured, we can safely be done at
 233                                  * this point.
 234                                  */
 235                                 if (!vg || !vg->num_vlans)
 236                                         goto insert;
 237                         }
 238                 }
 239         }
 240
 241 insert:
 242         /* insert new address,  may fail if invalid address or dup. */
 243         fdb_insert(br, p, newaddr, 0);
 244
 245         if (!vg || !vg->num_vlans)
 246                 goto done;
 247
 248         /* Now add entries for every VLAN configured on the port.
 249          * This function runs under RTNL so the bitmap will not change
 250          * from under us.
 251          */
 252         list_for_each_entry(v, &vg->vlan_list, vlist)
 253                 fdb_insert(br, p, newaddr, v->vid);
 254
 255 done:
 256         spin_unlock_bh(&br->hash_lock);
 257 }
 258
 259 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 260 {
 261         struct net_bridge_vlan_group *vg;
 262         struct net_bridge_fdb_entry *f;
 263         struct net_bridge_vlan *v;
 264
 265         spin_lock_bh(&br->hash_lock);
 266
 267         /* If old entry was unassociated with any port, then delete it. */
 268         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 269         if (f && f->is_local && !f->dst)
 270                 fdb_delete_local(br, NULL, f);
 271
 272         fdb_insert(br, NULL, newaddr, 0);
 273         vg = br_vlan_group(br);
 274         if (!vg || !vg->num_vlans)
 275                 goto out;
 276         /* Now remove and add entries for every VLAN configured on the
 277          * bridge.  This function runs under RTNL so the bitmap will not
 278          * change from under us.
 279          */
 280         list_for_each_entry(v, &vg->vlan_list, vlist) {
 281                 f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 282                 if (f && f->is_local && !f->dst)
 283                         fdb_delete_local(br, NULL, f);
 284                 fdb_insert(br, NULL, newaddr, v->vid);
 285         }
 286 out:
 287         spin_unlock_bh(&br->hash_lock);
 288 }
 289
 290 void br_fdb_cleanup(unsigned long _data)
 291 {
 292         struct net_bridge *br = (struct net_bridge *)_data;
 293         unsigned long delay = hold_time(br);
 294         unsigned long next_timer = jiffies + br->ageing_time;
 295         int i;
 296
 297         spin_lock(&br->hash_lock);
 298         for (i = 0; i < BR_HASH_SIZE; i++) {
 299                 struct net_bridge_fdb_entry *f;
 300                 struct hlist_node *n;
 301
 302                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 303                         unsigned long this_timer;
 304                         if (f->is_static)
 305                                 continue;
 306                         if (f->added_by_external_learn)
 307                                 continue;
 308                         this_timer = f->updated + delay;
 309                         if (time_before_eq(this_timer, jiffies))
 310                                 fdb_delete(br, f);
 311                         else if (time_before(this_timer, next_timer))
 312                                 next_timer = this_timer;
 313                 }
 314         }
 315         spin_unlock(&br->hash_lock);
 316
 317         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 318 }
 319
 320 /* Completely flush all dynamic entries in forwarding database.*/
 321 void br_fdb_flush(struct net_bridge *br)
 322 {
 323         int i;
 324
 325         spin_lock_bh(&br->hash_lock);
 326         for (i = 0; i < BR_HASH_SIZE; i++) {
 327                 struct net_bridge_fdb_entry *f;
 328                 struct hlist_node *n;
 329                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 330                         if (!f->is_static)
 331                                 fdb_delete(br, f);
 332                 }
 333         }
 334         spin_unlock_bh(&br->hash_lock);
 335 }
 336
 337 /* Flush all entries referring to a specific port.
 338  * if do_all is set also flush static entries
 339  * if vid is set delete all entries that match the vlan_id
 340  */
 341 void br_fdb_delete_by_port(struct net_bridge *br,
 342                            const struct net_bridge_port *p,
 343                            u16 vid,
 344                            int do_all)
 345 {
 346         int i;
 347
 348         spin_lock_bh(&br->hash_lock);
 349         for (i = 0; i < BR_HASH_SIZE; i++) {
 350                 struct hlist_node *h, *g;
 351
 352                 hlist_for_each_safe(h, g, &br->hash[i]) {
 353                         struct net_bridge_fdb_entry *f
 354                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 355                         if (f->dst != p)
 356                                 continue;
 357
 358                         if (!do_all)
 359                                 if (f->is_static || (vid && f->vlan_id != vid))
 360                                         continue;
 361
 362                         if (f->is_local)
 363                                 fdb_delete_local(br, p, f);
 364                         else
 365                                 fdb_delete(br, f);
 366                 }
 367         }
 368         spin_unlock_bh(&br->hash_lock);
 369 }
 370
 371 /* No locking or refcounting, assumes caller has rcu_read_lock */
 372 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 373                                           const unsigned char *addr,
 374                                           __u16 vid)
 375 {
 376         struct net_bridge_fdb_entry *fdb;
 377
 378         hlist_for_each_entry_rcu(fdb,
 379                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 380                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 381                     fdb->vlan_id == vid) {
 382                         if (unlikely(has_expired(br, fdb)))
 383                                 break;
 384                         return fdb;
 385                 }
 386         }
 387
 388         return NULL;
 389 }
 390
 391 #if IS_ENABLED(CONFIG_ATM_LANE)
 392 /* Interface used by ATM LANE hook to test
 393  * if an addr is on some other bridge port */
 394 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 395 {
 396         struct net_bridge_fdb_entry *fdb;
 397         struct net_bridge_port *port;
 398         int ret;
 399
 400         rcu_read_lock();
 401         port = br_port_get_rcu(dev);
 402         if (!port)
 403                 ret = 0;
 404         else {
 405                 fdb = __br_fdb_get(port->br, addr, 0);
 406                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 407                         fdb->dst->state == BR_STATE_FORWARDING;
 408         }
 409         rcu_read_unlock();
 410
 411         return ret;
 412 }
 413 #endif /* CONFIG_ATM_LANE */
 414
 415 /*
 416  * Fill buffer with forwarding table records in
 417  * the API format.
 418  */
 419 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 420                    unsigned long maxnum, unsigned long skip)
 421 {
 422         struct __fdb_entry *fe = buf;
 423         int i, num = 0;
 424         struct net_bridge_fdb_entry *f;
 425
 426         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 427
 428         rcu_read_lock();
 429         for (i = 0; i < BR_HASH_SIZE; i++) {
 430                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 431                         if (num >= maxnum)
 432                                 goto out;
 433
 434                         if (has_expired(br, f))
 435                                 continue;
 436
 437                         /* ignore pseudo entry for local MAC address */
 438                         if (!f->dst)
 439                                 continue;
 440
 441                         if (skip) {
 442                                 --skip;
 443                                 continue;
 444                         }
 445
 446                         /* convert from internal format to API */
 447                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 448
 449                         /* due to ABI compat need to split into hi/lo */
 450                         fe->port_no = f->dst->port_no;
 451                         fe->port_hi = f->dst->port_no >> 8;
 452
 453                         fe->is_local = f->is_local;
 454                         if (!f->is_static)
 455                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 456                         ++fe;
 457                         ++num;
 458                 }
 459         }
 460
 461  out:
 462         rcu_read_unlock();
 463
 464         return num;
 465 }
 466
 467 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 468                                              const unsigned char *addr,
 469                                              __u16 vid)
 470 {
 471         struct net_bridge_fdb_entry *fdb;
 472
 473         hlist_for_each_entry(fdb, head, hlist) {
 474                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 475                     fdb->vlan_id == vid)
 476                         return fdb;
 477         }
 478         return NULL;
 479 }
 480
 481 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 482                                                  const unsigned char *addr,
 483                                                  __u16 vid)
 484 {
 485         struct net_bridge_fdb_entry *fdb;
 486
 487         hlist_for_each_entry_rcu(fdb, head, hlist) {
 488                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 489                     fdb->vlan_id == vid)
 490                         return fdb;
 491         }
 492         return NULL;
 493 }
 494
 495 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 496                                                struct net_bridge_port *source,
 497                                                const unsigned char *addr,
 498                                                __u16 vid,
 499                                                unsigned char is_local,
 500                                                unsigned char is_static)
 501 {
 502         struct net_bridge_fdb_entry *fdb;
 503
 504         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 505         if (fdb) {
 506                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 507                 fdb->dst = source;
 508                 fdb->vlan_id = vid;
 509                 fdb->is_local = is_local;
 510                 fdb->is_static = is_static;
 511                 fdb->added_by_user = 0;
 512                 fdb->added_by_external_learn = 0;
 513                 fdb->updated = fdb->used = jiffies;
 514                 hlist_add_head_rcu(&fdb->hlist, head);
 515         }
 516         return fdb;
 517 }
 518
 519 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 520                   const unsigned char *addr, u16 vid)
 521 {
 522         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 523         struct net_bridge_fdb_entry *fdb;
 524
 525         if (!is_valid_ether_addr(addr))
 526                 return -EINVAL;
 527
 528         fdb = fdb_find(head, addr, vid);
 529         if (fdb) {
 530                 /* it is okay to have multiple ports with same
 531                  * address, just use the first one.
 532                  */
 533                 if (fdb->is_local)
 534                         return 0;
 535                 br_warn(br, "adding interface %s with same address "
 536                        "as a received packet\n",
 537                        source ? source->dev->name : br->dev->name);
 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 "
 584                                         "own address as source address\n",
 585                                         source->dev->name);
 586                 } else {
 587                         /* fastpath: update of existing entry */
 588                         if (unlikely(source != fdb->dst)) {
 589                                 fdb->dst = source;
 590                                 fdb_modified = true;
 591                         }
 592                         fdb->updated = jiffies;
 593                         if (unlikely(added_by_user))
 594                                 fdb->added_by_user = 1;
 595                         if (unlikely(fdb_modified))
 596                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 597                 }
 598         } else {
 599                 spin_lock(&br->hash_lock);
 600                 if (likely(!fdb_find(head, addr, vid))) {
 601                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 602                         if (fdb) {
 603                                 if (unlikely(added_by_user))
 604                                         fdb->added_by_user = 1;
 605                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 606                         }
 607                 }
 608                 /* else  we lose race and someone else inserts
 609                  * it first, don't bother updating
 610                  */
 611                 spin_unlock(&br->hash_lock);
 612         }
 613 }
 614
 615 static int fdb_to_nud(const struct net_bridge *br,
 616                       const struct net_bridge_fdb_entry *fdb)
 617 {
 618         if (fdb->is_local)
 619                 return NUD_PERMANENT;
 620         else if (fdb->is_static)
 621                 return NUD_NOARP;
 622         else if (has_expired(br, fdb))
 623                 return NUD_STALE;
 624         else
 625                 return NUD_REACHABLE;
 626 }
 627
 628 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 629                          const struct net_bridge_fdb_entry *fdb,
 630                          u32 portid, u32 seq, int type, unsigned int flags)
 631 {
 632         unsigned long now = jiffies;
 633         struct nda_cacheinfo ci;
 634         struct nlmsghdr *nlh;
 635         struct ndmsg *ndm;
 636
 637         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 638         if (nlh == NULL)
 639                 return -EMSGSIZE;
 640
 641         ndm = nlmsg_data(nlh);
 642         ndm->ndm_family  = AF_BRIDGE;
 643         ndm->ndm_pad1    = 0;
 644         ndm->ndm_pad2    = 0;
 645         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 646         ndm->ndm_type    = 0;
 647         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 648         ndm->ndm_state   = fdb_to_nud(br, fdb);
 649
 650         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 651                 goto nla_put_failure;
 652         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 653                 goto nla_put_failure;
 654         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 655         ci.ndm_confirmed = 0;
 656         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 657         ci.ndm_refcnt    = 0;
 658         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 659                 goto nla_put_failure;
 660
 661         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 662                 goto nla_put_failure;
 663
 664         nlmsg_end(skb, nlh);
 665         return 0;
 666
 667 nla_put_failure:
 668         nlmsg_cancel(skb, nlh);
 669         return -EMSGSIZE;
 670 }
 671
 672 static inline size_t fdb_nlmsg_size(void)
 673 {
 674         return NLMSG_ALIGN(sizeof(struct ndmsg))
 675                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 676                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 677                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 678                 + nla_total_size(sizeof(struct nda_cacheinfo));
 679 }
 680
 681 static void fdb_notify(struct net_bridge *br,
 682                        const struct net_bridge_fdb_entry *fdb, int type)
 683 {
 684         struct net *net = dev_net(br->dev);
 685         struct sk_buff *skb;
 686         int err = -ENOBUFS;
 687
 688         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 689         if (skb == NULL)
 690                 goto errout;
 691
 692         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 693         if (err < 0) {
 694                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 695                 WARN_ON(err == -EMSGSIZE);
 696                 kfree_skb(skb);
 697                 goto errout;
 698         }
 699         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 700         return;
 701 errout:
 702         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 703 }
 704
 705 /* Dump information about entries, in response to GETNEIGH */
 706 int br_fdb_dump(struct sk_buff *skb,
 707                 struct netlink_callback *cb,
 708                 struct net_device *dev,
 709                 struct net_device *filter_dev,
 710                 int idx)
 711 {
 712         struct net_bridge *br = netdev_priv(dev);
 713         int i;
 714
 715         if (!(dev->priv_flags & IFF_EBRIDGE))
 716                 goto out;
 717
 718         if (!filter_dev)
 719                 idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 720
 721         for (i = 0; i < BR_HASH_SIZE; i++) {
 722                 struct net_bridge_fdb_entry *f;
 723
 724                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 725                         if (idx < cb->args[0])
 726                                 goto skip;
 727
 728                         if (filter_dev &&
 729                             (!f->dst || f->dst->dev != filter_dev)) {
 730                                 if (filter_dev != dev)
 731                                         goto skip;
 732                                 /* !f->dst is a special case for bridge
 733                                  * It means the MAC belongs to the bridge
 734                                  * Therefore need a little more filtering
 735                                  * we only want to dump the !f->dst case
 736                                  */
 737                                 if (f->dst)
 738                                         goto skip;
 739                         }
 740                         if (!filter_dev && f->dst)
 741                                 goto skip;
 742
 743                         if (fdb_fill_info(skb, br, f,
 744                                           NETLINK_CB(cb->skb).portid,
 745                                           cb->nlh->nlmsg_seq,
 746                                           RTM_NEWNEIGH,
 747                                           NLM_F_MULTI) < 0)
 748                                 break;
 749 skip:
 750                         ++idx;
 751                 }
 752         }
 753
 754 out:
 755         return idx;
 756 }
 757
 758 /* Update (create or replace) forwarding database entry */
 759 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 760                          __u16 state, __u16 flags, __u16 vid)
 761 {
 762         struct net_bridge *br = source->br;
 763         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 764         struct net_bridge_fdb_entry *fdb;
 765         bool modified = false;
 766
 767         /* If the port cannot learn allow only local and static entries */
 768         if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 769             !(source->state == BR_STATE_LEARNING ||
 770               source->state == BR_STATE_FORWARDING))
 771                 return -EPERM;
 772
 773         fdb = fdb_find(head, addr, vid);
 774         if (fdb == NULL) {
 775                 if (!(flags & NLM_F_CREATE))
 776                         return -ENOENT;
 777
 778                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 779                 if (!fdb)
 780                         return -ENOMEM;
 781
 782                 modified = true;
 783         } else {
 784                 if (flags & NLM_F_EXCL)
 785                         return -EEXIST;
 786
 787                 if (fdb->dst != source) {
 788                         fdb->dst = source;
 789                         modified = true;
 790                 }
 791         }
 792
 793         if (fdb_to_nud(br, fdb) != state) {
 794                 if (state & NUD_PERMANENT) {
 795                         fdb->is_local = 1;
 796                         if (!fdb->is_static) {
 797                                 fdb->is_static = 1;
 798                                 fdb_add_hw_addr(br, addr);
 799                         }
 800                 } else if (state & NUD_NOARP) {
 801                         fdb->is_local = 0;
 802                         if (!fdb->is_static) {
 803                                 fdb->is_static = 1;
 804                                 fdb_add_hw_addr(br, addr);
 805                         }
 806                 } else {
 807                         fdb->is_local = 0;
 808                         if (fdb->is_static) {
 809                                 fdb->is_static = 0;
 810                                 fdb_del_hw_addr(br, addr);
 811                         }
 812                 }
 813
 814                 modified = true;
 815         }
 816         fdb->added_by_user = 1;
 817
 818         fdb->used = jiffies;
 819         if (modified) {
 820                 fdb->updated = jiffies;
 821                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 822         }
 823
 824         return 0;
 825 }
 826
 827 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 828                const unsigned char *addr, u16 nlh_flags, u16 vid)
 829 {
 830         int err = 0;
 831
 832         if (ndm->ndm_flags & NTF_USE) {
 833                 local_bh_disable();
 834                 rcu_read_lock();
 835                 br_fdb_update(p->br, p, addr, vid, true);
 836                 rcu_read_unlock();
 837                 local_bh_enable();
 838         } else {
 839                 spin_lock_bh(&p->br->hash_lock);
 840                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 841                                     nlh_flags, vid);
 842                 spin_unlock_bh(&p->br->hash_lock);
 843         }
 844
 845         return err;
 846 }
 847
 848 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 849 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 850                struct net_device *dev,
 851                const unsigned char *addr, u16 vid, u16 nlh_flags)
 852 {
 853         struct net_bridge_vlan_group *vg;
 854         struct net_bridge_port *p = NULL;
 855         struct net_bridge_vlan *v;
 856         struct net_bridge *br = NULL;
 857         int err = 0;
 858
 859         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 860                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 861                 return -EINVAL;
 862         }
 863
 864         if (is_zero_ether_addr(addr)) {
 865                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 866                 return -EINVAL;
 867         }
 868
 869         if (dev->priv_flags & IFF_EBRIDGE) {
 870                 br = netdev_priv(dev);
 871                 vg = br_vlan_group(br);
 872         } else {
 873                 p = br_port_get_rtnl(dev);
 874                 if (!p) {
 875                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 876                                 dev->name);
 877                         return -EINVAL;
 878                 }
 879                 vg = nbp_vlan_group(p);
 880         }
 881
 882         if (vid) {
 883                 v = br_vlan_find(vg, vid);
 884                 if (!v || !br_vlan_should_use(v)) {
 885                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 886                         return -EINVAL;
 887                 }
 888
 889                 /* VID was specified, so use it. */
 890                 if (dev->priv_flags & IFF_EBRIDGE)
 891                         err = br_fdb_insert(br, NULL, addr, vid);
 892                 else
 893                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 894         } else {
 895                 if (dev->priv_flags & IFF_EBRIDGE)
 896                         err = br_fdb_insert(br, NULL, addr, 0);
 897                 else
 898                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 899                 if (err || !vg || !vg->num_vlans)
 900                         goto out;
 901
 902                 /* We have vlans configured on this port and user didn't
 903                  * specify a VLAN.  To be nice, add/update entry for every
 904                  * vlan on this port.
 905                  */
 906                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 907                         if (!br_vlan_should_use(v))
 908                                 continue;
 909                         if (dev->priv_flags & IFF_EBRIDGE)
 910                                 err = br_fdb_insert(br, NULL, addr, v->vid);
 911                         else
 912                                 err = __br_fdb_add(ndm, p, addr, nlh_flags,
 913                                                    v->vid);
 914                         if (err)
 915                                 goto out;
 916                 }
 917         }
 918
 919 out:
 920         return err;
 921 }
 922
 923 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 924                               u16 vid)
 925 {
 926         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 927         struct net_bridge_fdb_entry *fdb;
 928
 929         fdb = fdb_find(head, addr, vid);
 930         if (!fdb)
 931                 return -ENOENT;
 932
 933         fdb_delete(br, fdb);
 934         return 0;
 935 }
 936
 937 static int __br_fdb_delete_by_addr(struct net_bridge *br,
 938                                    const unsigned char *addr, u16 vid)
 939 {
 940         int err;
 941
 942         spin_lock_bh(&br->hash_lock);
 943         err = fdb_delete_by_addr(br, addr, vid);
 944         spin_unlock_bh(&br->hash_lock);
 945
 946         return err;
 947 }
 948
 949 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 950                                        const u8 *addr, u16 vlan)
 951 {
 952         struct net_bridge *br = p->br;
 953         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 954         struct net_bridge_fdb_entry *fdb;
 955
 956         fdb = fdb_find(head, addr, vlan);
 957         if (!fdb || fdb->dst != p)
 958                 return -ENOENT;
 959
 960         fdb_delete(br, fdb);
 961         return 0;
 962 }
 963
 964 static int __br_fdb_delete(struct net_bridge_port *p,
 965                            const unsigned char *addr, u16 vid)
 966 {
 967         int err;
 968
 969         spin_lock_bh(&p->br->hash_lock);
 970         err = fdb_delete_by_addr_and_port(p, addr, vid);
 971         spin_unlock_bh(&p->br->hash_lock);
 972
 973         return err;
 974 }
 975
 976 /* Remove neighbor entry with RTM_DELNEIGH */
 977 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 978                   struct net_device *dev,
 979                   const unsigned char *addr, u16 vid)
 980 {
 981         struct net_bridge_vlan_group *vg;
 982         struct net_bridge_port *p = NULL;
 983         struct net_bridge_vlan *v;
 984         struct net_bridge *br = NULL;
 985         int err;
 986
 987         if (dev->priv_flags & IFF_EBRIDGE) {
 988                 br = netdev_priv(dev);
 989                 vg = br_vlan_group(br);
 990         } else {
 991                 p = br_port_get_rtnl(dev);
 992                 if (!p) {
 993                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 994                                 dev->name);
 995                         return -EINVAL;
 996                 }
 997                 vg = nbp_vlan_group(p);
 998         }
 999
1000         if (vid) {
1001                 v = br_vlan_find(vg, vid);
1002                 if (!v) {
1003                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1004                         return -EINVAL;
1005                 }
1006
1007                 if (dev->priv_flags & IFF_EBRIDGE)
1008                         err = __br_fdb_delete_by_addr(br, addr, vid);
1009                 else
1010                         err = __br_fdb_delete(p, addr, vid);
1011         } else {
1012                 err = -ENOENT;
1013                 if (dev->priv_flags & IFF_EBRIDGE)
1014                         err = __br_fdb_delete_by_addr(br, addr, 0);
1015                 else
1016                         err &= __br_fdb_delete(p, addr, 0);
1017
1018                 if (!vg || !vg->num_vlans)
1019                         goto out;
1020
1021                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1022                         if (!br_vlan_should_use(v))
1023                                 continue;
1024                         if (dev->priv_flags & IFF_EBRIDGE)
1025                                 err = __br_fdb_delete_by_addr(br, addr, v->vid);
1026                         else
1027                                 err &= __br_fdb_delete(p, addr, v->vid);
1028                 }
1029         }
1030 out:
1031         return err;
1032 }
1033
1034 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1035 {
1036         struct net_bridge_fdb_entry *fdb, *tmp;
1037         int i;
1038         int err;
1039
1040         ASSERT_RTNL();
1041
1042         for (i = 0; i < BR_HASH_SIZE; i++) {
1043                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1044                         /* We only care for static entries */
1045                         if (!fdb->is_static)
1046                                 continue;
1047
1048                         err = dev_uc_add(p->dev, fdb->addr.addr);
1049                         if (err)
1050                                 goto rollback;
1051                 }
1052         }
1053         return 0;
1054
1055 rollback:
1056         for (i = 0; i < BR_HASH_SIZE; i++) {
1057                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1058                         /* If we reached the fdb that failed, we can stop */
1059                         if (tmp == fdb)
1060                                 break;
1061
1062                         /* We only care for static entries */
1063                         if (!tmp->is_static)
1064                                 continue;
1065
1066                         dev_uc_del(p->dev, tmp->addr.addr);
1067                 }
1068         }
1069         return err;
1070 }
1071
1072 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1073 {
1074         struct net_bridge_fdb_entry *fdb;
1075         int i;
1076
1077         ASSERT_RTNL();
1078
1079         for (i = 0; i < BR_HASH_SIZE; i++) {
1080                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1081                         /* We only care for static entries */
1082                         if (!fdb->is_static)
1083                                 continue;
1084
1085                         dev_uc_del(p->dev, fdb->addr.addr);
1086                 }
1087         }
1088 }
1089
1090 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1091                               const unsigned char *addr, u16 vid)
1092 {
1093         struct hlist_head *head;
1094         struct net_bridge_fdb_entry *fdb;
1095         int err = 0;
1096
1097         ASSERT_RTNL();
1098         spin_lock_bh(&br->hash_lock);
1099
1100         head = &br->hash[br_mac_hash(addr, vid)];
1101         fdb = fdb_find(head, addr, vid);
1102         if (!fdb) {
1103                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1104                 if (!fdb) {
1105                         err = -ENOMEM;
1106                         goto err_unlock;
1107                 }
1108                 fdb->added_by_external_learn = 1;
1109                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1110         } else if (fdb->added_by_external_learn) {
1111                 /* Refresh entry */
1112                 fdb->updated = fdb->used = jiffies;
1113         } else if (!fdb->added_by_user) {
1114                 /* Take over SW learned entry */
1115                 fdb->added_by_external_learn = 1;
1116                 fdb->updated = jiffies;
1117                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1118         }
1119
1120 err_unlock:
1121         spin_unlock_bh(&br->hash_lock);
1122
1123         return err;
1124 }
1125
1126 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1127                               const unsigned char *addr, u16 vid)
1128 {
1129         struct hlist_head *head;
1130         struct net_bridge_fdb_entry *fdb;
1131         int err = 0;
1132
1133         ASSERT_RTNL();
1134         spin_lock_bh(&br->hash_lock);
1135
1136         head = &br->hash[br_mac_hash(addr, vid)];
1137         fdb = fdb_find(head, addr, vid);
1138         if (fdb && fdb->added_by_external_learn)
1139                 fdb_delete(br, fdb);
1140         else
1141                 err = -ENOENT;
1142
1143         spin_unlock_bh(&br->hash_lock);
1144
1145         return err;
1146 }