kernel/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                 if (!br_vlan_should_use(v))
 282                         continue;
 283                 f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 284                 if (f && f->is_local && !f->dst)
 285                         fdb_delete_local(br, NULL, f);
 286                 fdb_insert(br, NULL, newaddr, v->vid);
 287         }
 288 out:
 289         spin_unlock_bh(&br->hash_lock);
 290 }
 291
 292 void br_fdb_cleanup(unsigned long _data)
 293 {
 294         struct net_bridge *br = (struct net_bridge *)_data;
 295         unsigned long delay = hold_time(br);
 296         unsigned long next_timer = jiffies + br->ageing_time;
 297         int i;
 298
 299         spin_lock(&br->hash_lock);
 300         for (i = 0; i < BR_HASH_SIZE; i++) {
 301                 struct net_bridge_fdb_entry *f;
 302                 struct hlist_node *n;
 303
 304                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 305                         unsigned long this_timer;
 306                         if (f->is_static)
 307                                 continue;
 308                         if (f->added_by_external_learn)
 309                                 continue;
 310                         this_timer = f->updated + delay;
 311                         if (time_before_eq(this_timer, jiffies))
 312                                 fdb_delete(br, f);
 313                         else if (time_before(this_timer, next_timer))
 314                                 next_timer = this_timer;
 315                 }
 316         }
 317         spin_unlock(&br->hash_lock);
 318
 319         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 320 }
 321
 322 /* Completely flush all dynamic entries in forwarding database.*/
 323 void br_fdb_flush(struct net_bridge *br)
 324 {
 325         int i;
 326
 327         spin_lock_bh(&br->hash_lock);
 328         for (i = 0; i < BR_HASH_SIZE; i++) {
 329                 struct net_bridge_fdb_entry *f;
 330                 struct hlist_node *n;
 331                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 332                         if (!f->is_static)
 333                                 fdb_delete(br, f);
 334                 }
 335         }
 336         spin_unlock_bh(&br->hash_lock);
 337 }
 338
 339 /* Flush all entries referring to a specific port.
 340  * if do_all is set also flush static entries
 341  * if vid is set delete all entries that match the vlan_id
 342  */
 343 void br_fdb_delete_by_port(struct net_bridge *br,
 344                            const struct net_bridge_port *p,
 345                            u16 vid,
 346                            int do_all)
 347 {
 348         int i;
 349
 350         spin_lock_bh(&br->hash_lock);
 351         for (i = 0; i < BR_HASH_SIZE; i++) {
 352                 struct hlist_node *h, *g;
 353
 354                 hlist_for_each_safe(h, g, &br->hash[i]) {
 355                         struct net_bridge_fdb_entry *f
 356                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 357                         if (f->dst != p)
 358                                 continue;
 359
 360                         if (!do_all)
 361                                 if (f->is_static || (vid && f->vlan_id != vid))
 362                                         continue;
 363
 364                         if (f->is_local)
 365                                 fdb_delete_local(br, p, f);
 366                         else
 367                                 fdb_delete(br, f);
 368                 }
 369         }
 370         spin_unlock_bh(&br->hash_lock);
 371 }
 372
 373 /* No locking or refcounting, assumes caller has rcu_read_lock */
 374 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 375                                           const unsigned char *addr,
 376                                           __u16 vid)
 377 {
 378         struct net_bridge_fdb_entry *fdb;
 379
 380         hlist_for_each_entry_rcu(fdb,
 381                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 382                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 383                     fdb->vlan_id == vid) {
 384                         if (unlikely(has_expired(br, fdb)))
 385                                 break;
 386                         return fdb;
 387                 }
 388         }
 389
 390         return NULL;
 391 }
 392
 393 #if IS_ENABLED(CONFIG_ATM_LANE)
 394 /* Interface used by ATM LANE hook to test
 395  * if an addr is on some other bridge port */
 396 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 397 {
 398         struct net_bridge_fdb_entry *fdb;
 399         struct net_bridge_port *port;
 400         int ret;
 401
 402         rcu_read_lock();
 403         port = br_port_get_rcu(dev);
 404         if (!port)
 405                 ret = 0;
 406         else {
 407                 fdb = __br_fdb_get(port->br, addr, 0);
 408                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 409                         fdb->dst->state == BR_STATE_FORWARDING;
 410         }
 411         rcu_read_unlock();
 412
 413         return ret;
 414 }
 415 #endif /* CONFIG_ATM_LANE */
 416
 417 /*
 418  * Fill buffer with forwarding table records in
 419  * the API format.
 420  */
 421 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 422                    unsigned long maxnum, unsigned long skip)
 423 {
 424         struct __fdb_entry *fe = buf;
 425         int i, num = 0;
 426         struct net_bridge_fdb_entry *f;
 427
 428         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 429
 430         rcu_read_lock();
 431         for (i = 0; i < BR_HASH_SIZE; i++) {
 432                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 433                         if (num >= maxnum)
 434                                 goto out;
 435
 436                         if (has_expired(br, f))
 437                                 continue;
 438
 439                         /* ignore pseudo entry for local MAC address */
 440                         if (!f->dst)
 441                                 continue;
 442
 443                         if (skip) {
 444                                 --skip;
 445                                 continue;
 446                         }
 447
 448                         /* convert from internal format to API */
 449                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 450
 451                         /* due to ABI compat need to split into hi/lo */
 452                         fe->port_no = f->dst->port_no;
 453                         fe->port_hi = f->dst->port_no >> 8;
 454
 455                         fe->is_local = f->is_local;
 456                         if (!f->is_static)
 457                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 458                         ++fe;
 459                         ++num;
 460                 }
 461         }
 462
 463  out:
 464         rcu_read_unlock();
 465
 466         return num;
 467 }
 468
 469 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 470                                              const unsigned char *addr,
 471                                              __u16 vid)
 472 {
 473         struct net_bridge_fdb_entry *fdb;
 474
 475         hlist_for_each_entry(fdb, head, hlist) {
 476                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 477                     fdb->vlan_id == vid)
 478                         return fdb;
 479         }
 480         return NULL;
 481 }
 482
 483 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 484                                                  const unsigned char *addr,
 485                                                  __u16 vid)
 486 {
 487         struct net_bridge_fdb_entry *fdb;
 488
 489         hlist_for_each_entry_rcu(fdb, head, hlist) {
 490                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 491                     fdb->vlan_id == vid)
 492                         return fdb;
 493         }
 494         return NULL;
 495 }
 496
 497 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 498                                                struct net_bridge_port *source,
 499                                                const unsigned char *addr,
 500                                                __u16 vid,
 501                                                unsigned char is_local,
 502                                                unsigned char is_static)
 503 {
 504         struct net_bridge_fdb_entry *fdb;
 505
 506         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 507         if (fdb) {
 508                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 509                 fdb->dst = source;
 510                 fdb->vlan_id = vid;
 511                 fdb->is_local = is_local;
 512                 fdb->is_static = is_static;
 513                 fdb->added_by_user = 0;
 514                 fdb->added_by_external_learn = 0;
 515                 fdb->updated = fdb->used = jiffies;
 516                 hlist_add_head_rcu(&fdb->hlist, head);
 517         }
 518         return fdb;
 519 }
 520
 521 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 522                   const unsigned char *addr, u16 vid)
 523 {
 524         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 525         struct net_bridge_fdb_entry *fdb;
 526
 527         if (!is_valid_ether_addr(addr))
 528                 return -EINVAL;
 529
 530         fdb = fdb_find(head, addr, vid);
 531         if (fdb) {
 532                 /* it is okay to have multiple ports with same
 533                  * address, just use the first one.
 534                  */
 535                 if (fdb->is_local)
 536                         return 0;
 537                 br_warn(br, "adding interface %s with same address "
 538                        "as a received packet\n",
 539                        source ? source->dev->name : br->dev->name);
 540                 fdb_delete(br, fdb);
 541         }
 542
 543         fdb = fdb_create(head, source, addr, vid, 1, 1);
 544         if (!fdb)
 545                 return -ENOMEM;
 546
 547         fdb_add_hw_addr(br, addr);
 548         fdb_notify(br, fdb, RTM_NEWNEIGH);
 549         return 0;
 550 }
 551
 552 /* Add entry for local address of interface */
 553 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 554                   const unsigned char *addr, u16 vid)
 555 {
 556         int ret;
 557
 558         spin_lock_bh(&br->hash_lock);
 559         ret = fdb_insert(br, source, addr, vid);
 560         spin_unlock_bh(&br->hash_lock);
 561         return ret;
 562 }
 563
 564 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 565                    const unsigned char *addr, u16 vid, bool added_by_user)
 566 {
 567         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 568         struct net_bridge_fdb_entry *fdb;
 569         bool fdb_modified = false;
 570
 571         /* some users want to always flood. */
 572         if (hold_time(br) == 0)
 573                 return;
 574
 575         /* ignore packets unless we are using this port */
 576         if (!(source->state == BR_STATE_LEARNING ||
 577               source->state == BR_STATE_FORWARDING))
 578                 return;
 579
 580         fdb = fdb_find_rcu(head, addr, vid);
 581         if (likely(fdb)) {
 582                 /* attempt to update an entry for a local interface */
 583                 if (unlikely(fdb->is_local)) {
 584                         if (net_ratelimit())
 585                                 br_warn(br, "received packet on %s with "
 586                                         "own address as source address\n",
 587                                         source->dev->name);
 588                 } else {
 589                         /* fastpath: update of existing entry */
 590                         if (unlikely(source != fdb->dst)) {
 591                                 fdb->dst = source;
 592                                 fdb_modified = true;
 593                         }
 594                         fdb->updated = jiffies;
 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(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 i;
 716
 717         if (!(dev->priv_flags & IFF_EBRIDGE))
 718                 goto out;
 719
 720         if (!filter_dev)
 721                 idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 722
 723         for (i = 0; i < BR_HASH_SIZE; i++) {
 724                 struct net_bridge_fdb_entry *f;
 725
 726                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 727                         if (idx < cb->args[0])
 728                                 goto skip;
 729
 730                         if (filter_dev &&
 731                             (!f->dst || f->dst->dev != filter_dev)) {
 732                                 if (filter_dev != dev)
 733                                         goto skip;
 734                                 /* !f->dst is a special case for bridge
 735                                  * It means the MAC belongs to the bridge
 736                                  * Therefore need a little more filtering
 737                                  * we only want to dump the !f->dst case
 738                                  */
 739                                 if (f->dst)
 740                                         goto skip;
 741                         }
 742                         if (!filter_dev && f->dst)
 743                                 goto skip;
 744
 745                         if (fdb_fill_info(skb, br, f,
 746                                           NETLINK_CB(cb->skb).portid,
 747                                           cb->nlh->nlmsg_seq,
 748                                           RTM_NEWNEIGH,
 749                                           NLM_F_MULTI) < 0)
 750                                 break;
 751 skip:
 752                         ++idx;
 753                 }
 754         }
 755
 756 out:
 757         return idx;
 758 }
 759
 760 /* Update (create or replace) forwarding database entry */
 761 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 762                          __u16 state, __u16 flags, __u16 vid)
 763 {
 764         struct net_bridge *br = source->br;
 765         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 766         struct net_bridge_fdb_entry *fdb;
 767         bool modified = false;
 768
 769         /* If the port cannot learn allow only local and static entries */
 770         if (!(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 771             !(source->state == BR_STATE_LEARNING ||
 772               source->state == BR_STATE_FORWARDING))
 773                 return -EPERM;
 774
 775         fdb = fdb_find(head, addr, vid);
 776         if (fdb == NULL) {
 777                 if (!(flags & NLM_F_CREATE))
 778                         return -ENOENT;
 779
 780                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 781                 if (!fdb)
 782                         return -ENOMEM;
 783
 784                 modified = true;
 785         } else {
 786                 if (flags & NLM_F_EXCL)
 787                         return -EEXIST;
 788
 789                 if (fdb->dst != source) {
 790                         fdb->dst = source;
 791                         modified = true;
 792                 }
 793         }
 794
 795         if (fdb_to_nud(br, fdb) != state) {
 796                 if (state & NUD_PERMANENT) {
 797                         fdb->is_local = 1;
 798                         if (!fdb->is_static) {
 799                                 fdb->is_static = 1;
 800                                 fdb_add_hw_addr(br, addr);
 801                         }
 802                 } else if (state & NUD_NOARP) {
 803                         fdb->is_local = 0;
 804                         if (!fdb->is_static) {
 805                                 fdb->is_static = 1;
 806                                 fdb_add_hw_addr(br, addr);
 807                         }
 808                 } else {
 809                         fdb->is_local = 0;
 810                         if (fdb->is_static) {
 811                                 fdb->is_static = 0;
 812                                 fdb_del_hw_addr(br, addr);
 813                         }
 814                 }
 815
 816                 modified = true;
 817         }
 818         fdb->added_by_user = 1;
 819
 820         fdb->used = jiffies;
 821         if (modified) {
 822                 fdb->updated = jiffies;
 823                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 824         }
 825
 826         return 0;
 827 }
 828
 829 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 830                const unsigned char *addr, u16 nlh_flags, u16 vid)
 831 {
 832         int err = 0;
 833
 834         if (ndm->ndm_flags & NTF_USE) {
 835                 local_bh_disable();
 836                 rcu_read_lock();
 837                 br_fdb_update(p->br, p, addr, vid, true);
 838                 rcu_read_unlock();
 839                 local_bh_enable();
 840         } else {
 841                 spin_lock_bh(&p->br->hash_lock);
 842                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 843                                     nlh_flags, vid);
 844                 spin_unlock_bh(&p->br->hash_lock);
 845         }
 846
 847         return err;
 848 }
 849
 850 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 851 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 852                struct net_device *dev,
 853                const unsigned char *addr, u16 vid, u16 nlh_flags)
 854 {
 855         struct net_bridge_vlan_group *vg;
 856         struct net_bridge_port *p = NULL;
 857         struct net_bridge_vlan *v;
 858         struct net_bridge *br = NULL;
 859         int err = 0;
 860
 861         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 862                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 863                 return -EINVAL;
 864         }
 865
 866         if (is_zero_ether_addr(addr)) {
 867                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 868                 return -EINVAL;
 869         }
 870
 871         if (dev->priv_flags & IFF_EBRIDGE) {
 872                 br = netdev_priv(dev);
 873                 vg = br_vlan_group(br);
 874         } else {
 875                 p = br_port_get_rtnl(dev);
 876                 if (!p) {
 877                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 878                                 dev->name);
 879                         return -EINVAL;
 880                 }
 881                 vg = nbp_vlan_group(p);
 882         }
 883
 884         if (vid) {
 885                 v = br_vlan_find(vg, vid);
 886                 if (!v || !br_vlan_should_use(v)) {
 887                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 888                         return -EINVAL;
 889                 }
 890
 891                 /* VID was specified, so use it. */
 892                 if (dev->priv_flags & IFF_EBRIDGE)
 893                         err = br_fdb_insert(br, NULL, addr, vid);
 894                 else
 895                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 896         } else {
 897                 if (dev->priv_flags & IFF_EBRIDGE)
 898                         err = br_fdb_insert(br, NULL, addr, 0);
 899                 else
 900                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 901                 if (err || !vg || !vg->num_vlans)
 902                         goto out;
 903
 904                 /* We have vlans configured on this port and user didn't
 905                  * specify a VLAN.  To be nice, add/update entry for every
 906                  * vlan on this port.
 907                  */
 908                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 909                         if (!br_vlan_should_use(v))
 910                                 continue;
 911                         if (dev->priv_flags & IFF_EBRIDGE)
 912                                 err = br_fdb_insert(br, NULL, addr, v->vid);
 913                         else
 914                                 err = __br_fdb_add(ndm, p, addr, nlh_flags,
 915                                                    v->vid);
 916                         if (err)
 917                                 goto out;
 918                 }
 919         }
 920
 921 out:
 922         return err;
 923 }
 924
 925 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 926                               u16 vid)
 927 {
 928         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 929         struct net_bridge_fdb_entry *fdb;
 930
 931         fdb = fdb_find(head, addr, vid);
 932         if (!fdb)
 933                 return -ENOENT;
 934
 935         fdb_delete(br, fdb);
 936         return 0;
 937 }
 938
 939 static int __br_fdb_delete_by_addr(struct net_bridge *br,
 940                                    const unsigned char *addr, u16 vid)
 941 {
 942         int err;
 943
 944         spin_lock_bh(&br->hash_lock);
 945         err = fdb_delete_by_addr(br, addr, vid);
 946         spin_unlock_bh(&br->hash_lock);
 947
 948         return err;
 949 }
 950
 951 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 952                                        const u8 *addr, u16 vlan)
 953 {
 954         struct net_bridge *br = p->br;
 955         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 956         struct net_bridge_fdb_entry *fdb;
 957
 958         fdb = fdb_find(head, addr, vlan);
 959         if (!fdb || fdb->dst != p)
 960                 return -ENOENT;
 961
 962         fdb_delete(br, fdb);
 963         return 0;
 964 }
 965
 966 static int __br_fdb_delete(struct net_bridge_port *p,
 967                            const unsigned char *addr, u16 vid)
 968 {
 969         int err;
 970
 971         spin_lock_bh(&p->br->hash_lock);
 972         err = fdb_delete_by_addr_and_port(p, addr, vid);
 973         spin_unlock_bh(&p->br->hash_lock);
 974
 975         return err;
 976 }
 977
 978 /* Remove neighbor entry with RTM_DELNEIGH */
 979 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 980                   struct net_device *dev,
 981                   const unsigned char *addr, u16 vid)
 982 {
 983         struct net_bridge_vlan_group *vg;
 984         struct net_bridge_port *p = NULL;
 985         struct net_bridge_vlan *v;
 986         struct net_bridge *br = NULL;
 987         int err;
 988
 989         if (dev->priv_flags & IFF_EBRIDGE) {
 990                 br = netdev_priv(dev);
 991                 vg = br_vlan_group(br);
 992         } else {
 993                 p = br_port_get_rtnl(dev);
 994                 if (!p) {
 995                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 996                                 dev->name);
 997                         return -EINVAL;
 998                 }
 999                 vg = nbp_vlan_group(p);
1000         }
1001
1002         if (vid) {
1003                 v = br_vlan_find(vg, vid);
1004                 if (!v) {
1005                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1006                         return -EINVAL;
1007                 }
1008
1009                 if (dev->priv_flags & IFF_EBRIDGE)
1010                         err = __br_fdb_delete_by_addr(br, addr, vid);
1011                 else
1012                         err = __br_fdb_delete(p, addr, vid);
1013         } else {
1014                 err = -ENOENT;
1015                 if (dev->priv_flags & IFF_EBRIDGE)
1016                         err = __br_fdb_delete_by_addr(br, addr, 0);
1017                 else
1018                         err &= __br_fdb_delete(p, addr, 0);
1019
1020                 if (!vg || !vg->num_vlans)
1021                         goto out;
1022
1023                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1024                         if (!br_vlan_should_use(v))
1025                                 continue;
1026                         if (dev->priv_flags & IFF_EBRIDGE)
1027                                 err = __br_fdb_delete_by_addr(br, addr, v->vid);
1028                         else
1029                                 err &= __br_fdb_delete(p, addr, v->vid);
1030                 }
1031         }
1032 out:
1033         return err;
1034 }
1035
1036 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1037 {
1038         struct net_bridge_fdb_entry *fdb, *tmp;
1039         int i;
1040         int err;
1041
1042         ASSERT_RTNL();
1043
1044         for (i = 0; i < BR_HASH_SIZE; i++) {
1045                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1046                         /* We only care for static entries */
1047                         if (!fdb->is_static)
1048                                 continue;
1049
1050                         err = dev_uc_add(p->dev, fdb->addr.addr);
1051                         if (err)
1052                                 goto rollback;
1053                 }
1054         }
1055         return 0;
1056
1057 rollback:
1058         for (i = 0; i < BR_HASH_SIZE; i++) {
1059                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1060                         /* If we reached the fdb that failed, we can stop */
1061                         if (tmp == fdb)
1062                                 break;
1063
1064                         /* We only care for static entries */
1065                         if (!tmp->is_static)
1066                                 continue;
1067
1068                         dev_uc_del(p->dev, tmp->addr.addr);
1069                 }
1070         }
1071         return err;
1072 }
1073
1074 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1075 {
1076         struct net_bridge_fdb_entry *fdb;
1077         int i;
1078
1079         ASSERT_RTNL();
1080
1081         for (i = 0; i < BR_HASH_SIZE; i++) {
1082                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1083                         /* We only care for static entries */
1084                         if (!fdb->is_static)
1085                                 continue;
1086
1087                         dev_uc_del(p->dev, fdb->addr.addr);
1088                 }
1089         }
1090 }
1091
1092 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1093                               const unsigned char *addr, u16 vid)
1094 {
1095         struct hlist_head *head;
1096         struct net_bridge_fdb_entry *fdb;
1097         int err = 0;
1098
1099         ASSERT_RTNL();
1100         spin_lock_bh(&br->hash_lock);
1101
1102         head = &br->hash[br_mac_hash(addr, vid)];
1103         fdb = fdb_find(head, addr, vid);
1104         if (!fdb) {
1105                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1106                 if (!fdb) {
1107                         err = -ENOMEM;
1108                         goto err_unlock;
1109                 }
1110                 fdb->added_by_external_learn = 1;
1111                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1112         } else if (fdb->added_by_external_learn) {
1113                 /* Refresh entry */
1114                 fdb->updated = fdb->used = jiffies;
1115         } else if (!fdb->added_by_user) {
1116                 /* Take over SW learned entry */
1117                 fdb->added_by_external_learn = 1;
1118                 fdb->updated = jiffies;
1119                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1120         }
1121
1122 err_unlock:
1123         spin_unlock_bh(&br->hash_lock);
1124
1125         return err;
1126 }
1127
1128 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1129                               const unsigned char *addr, u16 vid)
1130 {
1131         struct hlist_head *head;
1132         struct net_bridge_fdb_entry *fdb;
1133         int err = 0;
1134
1135         ASSERT_RTNL();
1136         spin_lock_bh(&br->hash_lock);
1137
1138         head = &br->hash[br_mac_hash(addr, vid)];
1139         fdb = fdb_find(head, addr, vid);
1140         if (fdb && fdb->added_by_external_learn)
1141                 fdb_delete(br, fdb);
1142         else
1143                 err = -ENOENT;
1144
1145         spin_unlock_bh(&br->hash_lock);
1146
1147         return err;
1148 }