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 "br_private.h"
  28
  29 static struct kmem_cache *br_fdb_cache __read_mostly;
  30 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  31                                              const unsigned char *addr,
  32                                              __u16 vid);
  33 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  34                       const unsigned char *addr, u16 vid);
  35 static void fdb_notify(struct net_bridge *br,
  36                        const struct net_bridge_fdb_entry *, int);
  37
  38 static u32 fdb_salt __read_mostly;
  39
  40 int __init br_fdb_init(void)
  41 {
  42         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  43                                          sizeof(struct net_bridge_fdb_entry),
  44                                          0,
  45                                          SLAB_HWCACHE_ALIGN, NULL);
  46         if (!br_fdb_cache)
  47                 return -ENOMEM;
  48
  49         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  50         return 0;
  51 }
  52
  53 void br_fdb_fini(void)
  54 {
  55         kmem_cache_destroy(br_fdb_cache);
  56 }
  57
  58
  59 /* if topology_changing then use forward_delay (default 15 sec)
  60  * otherwise keep longer (default 5 minutes)
  61  */
  62 static inline unsigned long hold_time(const struct net_bridge *br)
  63 {
  64         return br->topology_change ? br->forward_delay : br->ageing_time;
  65 }
  66
  67 static inline int has_expired(const struct net_bridge *br,
  68                                   const struct net_bridge_fdb_entry *fdb)
  69 {
  70         return !fdb->is_static &&
  71                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  72 }
  73
  74 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  75 {
  76         /* use 1 byte of OUI and 3 bytes of NIC */
  77         u32 key = get_unaligned((u32 *)(mac + 2));
  78         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  79 }
  80
  81 static void fdb_rcu_free(struct rcu_head *head)
  82 {
  83         struct net_bridge_fdb_entry *ent
  84                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  85         kmem_cache_free(br_fdb_cache, ent);
  86 }
  87
  88 /* When a static FDB entry is added, the mac address from the entry is
  89  * added to the bridge private HW address list and all required ports
  90  * are then updated with the new information.
  91  * Called under RTNL.
  92  */
  93 static void fdb_add_hw(struct net_bridge *br, const unsigned char *addr)
  94 {
  95         int err;
  96         struct net_bridge_port *p, *tmp;
  97
  98         ASSERT_RTNL();
  99
 100         list_for_each_entry(p, &br->port_list, list) {
 101                 if (!br_promisc_port(p)) {
 102                         err = dev_uc_add(p->dev, addr);
 103                         if (err)
 104                                 goto undo;
 105                 }
 106         }
 107
 108         return;
 109 undo:
 110         list_for_each_entry(tmp, &br->port_list, list) {
 111                 if (tmp == p)
 112                         break;
 113                 if (!br_promisc_port(tmp))
 114                         dev_uc_del(tmp->dev, addr);
 115         }
 116 }
 117
 118 /* When a static FDB entry is deleted, the HW address from that entry is
 119  * also removed from the bridge private HW address list and updates all
 120  * the ports with needed information.
 121  * Called under RTNL.
 122  */
 123 static void fdb_del_hw(struct net_bridge *br, const unsigned char *addr)
 124 {
 125         struct net_bridge_port *p;
 126
 127         ASSERT_RTNL();
 128
 129         list_for_each_entry(p, &br->port_list, list) {
 130                 if (!br_promisc_port(p))
 131                         dev_uc_del(p->dev, addr);
 132         }
 133 }
 134
 135 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 136 {
 137         if (f->is_static)
 138                 fdb_del_hw(br, f->addr.addr);
 139
 140         hlist_del_rcu(&f->hlist);
 141         fdb_notify(br, f, RTM_DELNEIGH);
 142         call_rcu(&f->rcu, fdb_rcu_free);
 143 }
 144
 145 /* Delete a local entry if no other port had the same address. */
 146 static void fdb_delete_local(struct net_bridge *br,
 147                              const struct net_bridge_port *p,
 148                              struct net_bridge_fdb_entry *f)
 149 {
 150         const unsigned char *addr = f->addr.addr;
 151         u16 vid = f->vlan_id;
 152         struct net_bridge_port *op;
 153
 154         /* Maybe another port has same hw addr? */
 155         list_for_each_entry(op, &br->port_list, list) {
 156                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 157                     (!vid || nbp_vlan_find(op, vid))) {
 158                         f->dst = op;
 159                         f->added_by_user = 0;
 160                         return;
 161                 }
 162         }
 163
 164         /* Maybe bridge device has same hw addr? */
 165         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 166             (!vid || br_vlan_find(br, vid))) {
 167                 f->dst = NULL;
 168                 f->added_by_user = 0;
 169                 return;
 170         }
 171
 172         fdb_delete(br, f);
 173 }
 174
 175 void br_fdb_find_delete_local(struct net_bridge *br,
 176                               const struct net_bridge_port *p,
 177                               const unsigned char *addr, u16 vid)
 178 {
 179         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 180         struct net_bridge_fdb_entry *f;
 181
 182         spin_lock_bh(&br->hash_lock);
 183         f = fdb_find(head, addr, vid);
 184         if (f && f->is_local && !f->added_by_user && f->dst == p)
 185                 fdb_delete_local(br, p, f);
 186         spin_unlock_bh(&br->hash_lock);
 187 }
 188
 189 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 190 {
 191         struct net_bridge *br = p->br;
 192         struct net_port_vlans *pv = nbp_get_vlan_info(p);
 193         bool no_vlan = !pv;
 194         int i;
 195         u16 vid;
 196
 197         spin_lock_bh(&br->hash_lock);
 198
 199         /* Search all chains since old address/hash is unknown */
 200         for (i = 0; i < BR_HASH_SIZE; i++) {
 201                 struct hlist_node *h;
 202                 hlist_for_each(h, &br->hash[i]) {
 203                         struct net_bridge_fdb_entry *f;
 204
 205                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 206                         if (f->dst == p && f->is_local && !f->added_by_user) {
 207                                 /* delete old one */
 208                                 fdb_delete_local(br, p, f);
 209
 210                                 /* if this port has no vlan information
 211                                  * configured, we can safely be done at
 212                                  * this point.
 213                                  */
 214                                 if (no_vlan)
 215                                         goto insert;
 216                         }
 217                 }
 218         }
 219
 220 insert:
 221         /* insert new address,  may fail if invalid address or dup. */
 222         fdb_insert(br, p, newaddr, 0);
 223
 224         if (no_vlan)
 225                 goto done;
 226
 227         /* Now add entries for every VLAN configured on the port.
 228          * This function runs under RTNL so the bitmap will not change
 229          * from under us.
 230          */
 231         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 232                 fdb_insert(br, p, newaddr, vid);
 233
 234 done:
 235         spin_unlock_bh(&br->hash_lock);
 236 }
 237
 238 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 239 {
 240         struct net_bridge_fdb_entry *f;
 241         struct net_port_vlans *pv;
 242         u16 vid = 0;
 243
 244         spin_lock_bh(&br->hash_lock);
 245
 246         /* If old entry was unassociated with any port, then delete it. */
 247         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 248         if (f && f->is_local && !f->dst)
 249                 fdb_delete_local(br, NULL, f);
 250
 251         fdb_insert(br, NULL, newaddr, 0);
 252
 253         /* Now remove and add entries for every VLAN configured on the
 254          * bridge.  This function runs under RTNL so the bitmap will not
 255          * change from under us.
 256          */
 257         pv = br_get_vlan_info(br);
 258         if (!pv)
 259                 goto out;
 260
 261         for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
 262                 f = __br_fdb_get(br, br->dev->dev_addr, vid);
 263                 if (f && f->is_local && !f->dst)
 264                         fdb_delete_local(br, NULL, f);
 265                 fdb_insert(br, NULL, newaddr, vid);
 266         }
 267 out:
 268         spin_unlock_bh(&br->hash_lock);
 269 }
 270
 271 void br_fdb_cleanup(unsigned long _data)
 272 {
 273         struct net_bridge *br = (struct net_bridge *)_data;
 274         unsigned long delay = hold_time(br);
 275         unsigned long next_timer = jiffies + br->ageing_time;
 276         int i;
 277
 278         spin_lock(&br->hash_lock);
 279         for (i = 0; i < BR_HASH_SIZE; i++) {
 280                 struct net_bridge_fdb_entry *f;
 281                 struct hlist_node *n;
 282
 283                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 284                         unsigned long this_timer;
 285                         if (f->is_static)
 286                                 continue;
 287                         this_timer = f->updated + delay;
 288                         if (time_before_eq(this_timer, jiffies))
 289                                 fdb_delete(br, f);
 290                         else if (time_before(this_timer, next_timer))
 291                                 next_timer = this_timer;
 292                 }
 293         }
 294         spin_unlock(&br->hash_lock);
 295
 296         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 297 }
 298
 299 /* Completely flush all dynamic entries in forwarding database.*/
 300 void br_fdb_flush(struct net_bridge *br)
 301 {
 302         int i;
 303
 304         spin_lock_bh(&br->hash_lock);
 305         for (i = 0; i < BR_HASH_SIZE; i++) {
 306                 struct net_bridge_fdb_entry *f;
 307                 struct hlist_node *n;
 308                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 309                         if (!f->is_static)
 310                                 fdb_delete(br, f);
 311                 }
 312         }
 313         spin_unlock_bh(&br->hash_lock);
 314 }
 315
 316 /* Flush all entries referring to a specific port.
 317  * if do_all is set also flush static entries
 318  */
 319 void br_fdb_delete_by_port(struct net_bridge *br,
 320                            const struct net_bridge_port *p,
 321                            int do_all)
 322 {
 323         int i;
 324
 325         spin_lock_bh(&br->hash_lock);
 326         for (i = 0; i < BR_HASH_SIZE; i++) {
 327                 struct hlist_node *h, *g;
 328
 329                 hlist_for_each_safe(h, g, &br->hash[i]) {
 330                         struct net_bridge_fdb_entry *f
 331                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 332                         if (f->dst != p)
 333                                 continue;
 334
 335                         if (f->is_static && !do_all)
 336                                 continue;
 337
 338                         if (f->is_local)
 339                                 fdb_delete_local(br, p, f);
 340                         else
 341                                 fdb_delete(br, f);
 342                 }
 343         }
 344         spin_unlock_bh(&br->hash_lock);
 345 }
 346
 347 /* No locking or refcounting, assumes caller has rcu_read_lock */
 348 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 349                                           const unsigned char *addr,
 350                                           __u16 vid)
 351 {
 352         struct net_bridge_fdb_entry *fdb;
 353
 354         hlist_for_each_entry_rcu(fdb,
 355                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 356                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 357                     fdb->vlan_id == vid) {
 358                         if (unlikely(has_expired(br, fdb)))
 359                                 break;
 360                         return fdb;
 361                 }
 362         }
 363
 364         return NULL;
 365 }
 366
 367 #if IS_ENABLED(CONFIG_ATM_LANE)
 368 /* Interface used by ATM LANE hook to test
 369  * if an addr is on some other bridge port */
 370 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 371 {
 372         struct net_bridge_fdb_entry *fdb;
 373         struct net_bridge_port *port;
 374         int ret;
 375
 376         rcu_read_lock();
 377         port = br_port_get_rcu(dev);
 378         if (!port)
 379                 ret = 0;
 380         else {
 381                 fdb = __br_fdb_get(port->br, addr, 0);
 382                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 383                         fdb->dst->state == BR_STATE_FORWARDING;
 384         }
 385         rcu_read_unlock();
 386
 387         return ret;
 388 }
 389 #endif /* CONFIG_ATM_LANE */
 390
 391 /*
 392  * Fill buffer with forwarding table records in
 393  * the API format.
 394  */
 395 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 396                    unsigned long maxnum, unsigned long skip)
 397 {
 398         struct __fdb_entry *fe = buf;
 399         int i, num = 0;
 400         struct net_bridge_fdb_entry *f;
 401
 402         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 403
 404         rcu_read_lock();
 405         for (i = 0; i < BR_HASH_SIZE; i++) {
 406                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 407                         if (num >= maxnum)
 408                                 goto out;
 409
 410                         if (has_expired(br, f))
 411                                 continue;
 412
 413                         /* ignore pseudo entry for local MAC address */
 414                         if (!f->dst)
 415                                 continue;
 416
 417                         if (skip) {
 418                                 --skip;
 419                                 continue;
 420                         }
 421
 422                         /* convert from internal format to API */
 423                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 424
 425                         /* due to ABI compat need to split into hi/lo */
 426                         fe->port_no = f->dst->port_no;
 427                         fe->port_hi = f->dst->port_no >> 8;
 428
 429                         fe->is_local = f->is_local;
 430                         if (!f->is_static)
 431                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 432                         ++fe;
 433                         ++num;
 434                 }
 435         }
 436
 437  out:
 438         rcu_read_unlock();
 439
 440         return num;
 441 }
 442
 443 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 444                                              const unsigned char *addr,
 445                                              __u16 vid)
 446 {
 447         struct net_bridge_fdb_entry *fdb;
 448
 449         hlist_for_each_entry(fdb, head, hlist) {
 450                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 451                     fdb->vlan_id == vid)
 452                         return fdb;
 453         }
 454         return NULL;
 455 }
 456
 457 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 458                                                  const unsigned char *addr,
 459                                                  __u16 vid)
 460 {
 461         struct net_bridge_fdb_entry *fdb;
 462
 463         hlist_for_each_entry_rcu(fdb, head, hlist) {
 464                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 465                     fdb->vlan_id == vid)
 466                         return fdb;
 467         }
 468         return NULL;
 469 }
 470
 471 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 472                                                struct net_bridge_port *source,
 473                                                const unsigned char *addr,
 474                                                __u16 vid)
 475 {
 476         struct net_bridge_fdb_entry *fdb;
 477
 478         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 479         if (fdb) {
 480                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 481                 fdb->dst = source;
 482                 fdb->vlan_id = vid;
 483                 fdb->is_local = 0;
 484                 fdb->is_static = 0;
 485                 fdb->added_by_user = 0;
 486                 fdb->updated = fdb->used = jiffies;
 487                 hlist_add_head_rcu(&fdb->hlist, head);
 488         }
 489         return fdb;
 490 }
 491
 492 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 493                   const unsigned char *addr, u16 vid)
 494 {
 495         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 496         struct net_bridge_fdb_entry *fdb;
 497
 498         if (!is_valid_ether_addr(addr))
 499                 return -EINVAL;
 500
 501         fdb = fdb_find(head, addr, vid);
 502         if (fdb) {
 503                 /* it is okay to have multiple ports with same
 504                  * address, just use the first one.
 505                  */
 506                 if (fdb->is_local)
 507                         return 0;
 508                 br_warn(br, "adding interface %s with same address "
 509                        "as a received packet\n",
 510                        source ? source->dev->name : br->dev->name);
 511                 fdb_delete(br, fdb);
 512         }
 513
 514         fdb = fdb_create(head, source, addr, vid);
 515         if (!fdb)
 516                 return -ENOMEM;
 517
 518         fdb->is_local = fdb->is_static = 1;
 519         fdb_add_hw(br, addr);
 520         fdb_notify(br, fdb, RTM_NEWNEIGH);
 521         return 0;
 522 }
 523
 524 /* Add entry for local address of interface */
 525 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 526                   const unsigned char *addr, u16 vid)
 527 {
 528         int ret;
 529
 530         spin_lock_bh(&br->hash_lock);
 531         ret = fdb_insert(br, source, addr, vid);
 532         spin_unlock_bh(&br->hash_lock);
 533         return ret;
 534 }
 535
 536 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 537                    const unsigned char *addr, u16 vid, bool added_by_user)
 538 {
 539         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 540         struct net_bridge_fdb_entry *fdb;
 541
 542         /* some users want to always flood. */
 543         if (hold_time(br) == 0)
 544                 return;
 545
 546         /* ignore packets unless we are using this port */
 547         if (!(source->state == BR_STATE_LEARNING ||
 548               source->state == BR_STATE_FORWARDING))
 549                 return;
 550
 551         fdb = fdb_find_rcu(head, addr, vid);
 552         if (likely(fdb)) {
 553                 /* attempt to update an entry for a local interface */
 554                 if (unlikely(fdb->is_local)) {
 555                         if (net_ratelimit())
 556                                 br_warn(br, "received packet on %s with "
 557                                         "own address as source address\n",
 558                                         source->dev->name);
 559                 } else {
 560                         /* fastpath: update of existing entry */
 561                         fdb->dst = source;
 562                         fdb->updated = jiffies;
 563                         if (unlikely(added_by_user))
 564                                 fdb->added_by_user = 1;
 565                 }
 566         } else {
 567                 spin_lock(&br->hash_lock);
 568                 if (likely(!fdb_find(head, addr, vid))) {
 569                         fdb = fdb_create(head, source, addr, vid);
 570                         if (fdb) {
 571                                 if (unlikely(added_by_user))
 572                                         fdb->added_by_user = 1;
 573                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 574                         }
 575                 }
 576                 /* else  we lose race and someone else inserts
 577                  * it first, don't bother updating
 578                  */
 579                 spin_unlock(&br->hash_lock);
 580         }
 581 }
 582
 583 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
 584 {
 585         if (fdb->is_local)
 586                 return NUD_PERMANENT;
 587         else if (fdb->is_static)
 588                 return NUD_NOARP;
 589         else if (has_expired(fdb->dst->br, fdb))
 590                 return NUD_STALE;
 591         else
 592                 return NUD_REACHABLE;
 593 }
 594
 595 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 596                          const struct net_bridge_fdb_entry *fdb,
 597                          u32 portid, u32 seq, int type, unsigned int flags)
 598 {
 599         unsigned long now = jiffies;
 600         struct nda_cacheinfo ci;
 601         struct nlmsghdr *nlh;
 602         struct ndmsg *ndm;
 603
 604         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 605         if (nlh == NULL)
 606                 return -EMSGSIZE;
 607
 608         ndm = nlmsg_data(nlh);
 609         ndm->ndm_family  = AF_BRIDGE;
 610         ndm->ndm_pad1    = 0;
 611         ndm->ndm_pad2    = 0;
 612         ndm->ndm_flags   = 0;
 613         ndm->ndm_type    = 0;
 614         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 615         ndm->ndm_state   = fdb_to_nud(fdb);
 616
 617         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 618                 goto nla_put_failure;
 619         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 620                 goto nla_put_failure;
 621         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 622         ci.ndm_confirmed = 0;
 623         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 624         ci.ndm_refcnt    = 0;
 625         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 626                 goto nla_put_failure;
 627
 628         if (nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 629                 goto nla_put_failure;
 630
 631         return nlmsg_end(skb, nlh);
 632
 633 nla_put_failure:
 634         nlmsg_cancel(skb, nlh);
 635         return -EMSGSIZE;
 636 }
 637
 638 static inline size_t fdb_nlmsg_size(void)
 639 {
 640         return NLMSG_ALIGN(sizeof(struct ndmsg))
 641                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 642                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 643                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 644                 + nla_total_size(sizeof(struct nda_cacheinfo));
 645 }
 646
 647 static void fdb_notify(struct net_bridge *br,
 648                        const struct net_bridge_fdb_entry *fdb, int type)
 649 {
 650         struct net *net = dev_net(br->dev);
 651         struct sk_buff *skb;
 652         int err = -ENOBUFS;
 653
 654         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 655         if (skb == NULL)
 656                 goto errout;
 657
 658         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 659         if (err < 0) {
 660                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 661                 WARN_ON(err == -EMSGSIZE);
 662                 kfree_skb(skb);
 663                 goto errout;
 664         }
 665         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 666         return;
 667 errout:
 668         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 669 }
 670
 671 /* Dump information about entries, in response to GETNEIGH */
 672 int br_fdb_dump(struct sk_buff *skb,
 673                 struct netlink_callback *cb,
 674                 struct net_device *dev,
 675                 int idx)
 676 {
 677         struct net_bridge *br = netdev_priv(dev);
 678         int i;
 679
 680         if (!(dev->priv_flags & IFF_EBRIDGE))
 681                 goto out;
 682
 683         for (i = 0; i < BR_HASH_SIZE; i++) {
 684                 struct net_bridge_fdb_entry *f;
 685
 686                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 687                         if (idx < cb->args[0])
 688                                 goto skip;
 689
 690                         if (fdb_fill_info(skb, br, f,
 691                                           NETLINK_CB(cb->skb).portid,
 692                                           cb->nlh->nlmsg_seq,
 693                                           RTM_NEWNEIGH,
 694                                           NLM_F_MULTI) < 0)
 695                                 break;
 696 skip:
 697                         ++idx;
 698                 }
 699         }
 700
 701 out:
 702         return idx;
 703 }
 704
 705 /* Update (create or replace) forwarding database entry */
 706 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 707                          __u16 state, __u16 flags, __u16 vid)
 708 {
 709         struct net_bridge *br = source->br;
 710         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 711         struct net_bridge_fdb_entry *fdb;
 712         bool modified = false;
 713
 714         fdb = fdb_find(head, addr, vid);
 715         if (fdb == NULL) {
 716                 if (!(flags & NLM_F_CREATE))
 717                         return -ENOENT;
 718
 719                 fdb = fdb_create(head, source, addr, vid);
 720                 if (!fdb)
 721                         return -ENOMEM;
 722
 723                 modified = true;
 724         } else {
 725                 if (flags & NLM_F_EXCL)
 726                         return -EEXIST;
 727
 728                 if (fdb->dst != source) {
 729                         fdb->dst = source;
 730                         modified = true;
 731                 }
 732         }
 733
 734         if (fdb_to_nud(fdb) != state) {
 735                 if (state & NUD_PERMANENT) {
 736                         fdb->is_local = 1;
 737                         if (!fdb->is_static) {
 738                                 fdb->is_static = 1;
 739                                 fdb_add_hw(br, addr);
 740                         }
 741                 } else if (state & NUD_NOARP) {
 742                         fdb->is_local = 0;
 743                         if (!fdb->is_static) {
 744                                 fdb->is_static = 1;
 745                                 fdb_add_hw(br, addr);
 746                         }
 747                 } else {
 748                         fdb->is_local = 0;
 749                         if (fdb->is_static) {
 750                                 fdb->is_static = 0;
 751                                 fdb_del_hw(br, addr);
 752                         }
 753                 }
 754
 755                 modified = true;
 756         }
 757         fdb->added_by_user = 1;
 758
 759         fdb->used = jiffies;
 760         if (modified) {
 761                 fdb->updated = jiffies;
 762                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 763         }
 764
 765         return 0;
 766 }
 767
 768 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 769                const unsigned char *addr, u16 nlh_flags, u16 vid)
 770 {
 771         int err = 0;
 772
 773         if (ndm->ndm_flags & NTF_USE) {
 774                 rcu_read_lock();
 775                 br_fdb_update(p->br, p, addr, vid, true);
 776                 rcu_read_unlock();
 777         } else {
 778                 spin_lock_bh(&p->br->hash_lock);
 779                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 780                                     nlh_flags, vid);
 781                 spin_unlock_bh(&p->br->hash_lock);
 782         }
 783
 784         return err;
 785 }
 786
 787 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 788 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 789                struct net_device *dev,
 790                const unsigned char *addr, u16 nlh_flags)
 791 {
 792         struct net_bridge_port *p;
 793         int err = 0;
 794         struct net_port_vlans *pv;
 795         unsigned short vid = VLAN_N_VID;
 796
 797         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 798                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 799                 return -EINVAL;
 800         }
 801
 802         if (tb[NDA_VLAN]) {
 803                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 804                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 805                         return -EINVAL;
 806                 }
 807
 808                 vid = nla_get_u16(tb[NDA_VLAN]);
 809
 810                 if (!vid || vid >= VLAN_VID_MASK) {
 811                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 812                                 vid);
 813                         return -EINVAL;
 814                 }
 815         }
 816
 817         if (is_zero_ether_addr(addr)) {
 818                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 819                 return -EINVAL;
 820         }
 821
 822         p = br_port_get_rtnl(dev);
 823         if (p == NULL) {
 824                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 825                         dev->name);
 826                 return -EINVAL;
 827         }
 828
 829         pv = nbp_get_vlan_info(p);
 830         if (vid != VLAN_N_VID) {
 831                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 832                         pr_info("bridge: RTM_NEWNEIGH with unconfigured "
 833                                 "vlan %d on port %s\n", vid, dev->name);
 834                         return -EINVAL;
 835                 }
 836
 837                 /* VID was specified, so use it. */
 838                 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 839         } else {
 840                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 841                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 842                         goto out;
 843                 }
 844
 845                 /* We have vlans configured on this port and user didn't
 846                  * specify a VLAN.  To be nice, add/update entry for every
 847                  * vlan on this port.
 848                  */
 849                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 850                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 851                         if (err)
 852                                 goto out;
 853                 }
 854         }
 855
 856 out:
 857         return err;
 858 }
 859
 860 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
 861 {
 862         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 863         struct net_bridge_fdb_entry *fdb;
 864
 865         fdb = fdb_find(head, addr, vlan);
 866         if (!fdb)
 867                 return -ENOENT;
 868
 869         fdb_delete(br, fdb);
 870         return 0;
 871 }
 872
 873 static int __br_fdb_delete(struct net_bridge_port *p,
 874                            const unsigned char *addr, u16 vid)
 875 {
 876         int err;
 877
 878         spin_lock_bh(&p->br->hash_lock);
 879         err = fdb_delete_by_addr(p->br, addr, vid);
 880         spin_unlock_bh(&p->br->hash_lock);
 881
 882         return err;
 883 }
 884
 885 /* Remove neighbor entry with RTM_DELNEIGH */
 886 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 887                   struct net_device *dev,
 888                   const unsigned char *addr)
 889 {
 890         struct net_bridge_port *p;
 891         int err;
 892         struct net_port_vlans *pv;
 893         unsigned short vid = VLAN_N_VID;
 894
 895         if (tb[NDA_VLAN]) {
 896                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 897                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 898                         return -EINVAL;
 899                 }
 900
 901                 vid = nla_get_u16(tb[NDA_VLAN]);
 902
 903                 if (!vid || vid >= VLAN_VID_MASK) {
 904                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 905                                 vid);
 906                         return -EINVAL;
 907                 }
 908         }
 909         p = br_port_get_rtnl(dev);
 910         if (p == NULL) {
 911                 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 912                         dev->name);
 913                 return -EINVAL;
 914         }
 915
 916         pv = nbp_get_vlan_info(p);
 917         if (vid != VLAN_N_VID) {
 918                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 919                         pr_info("bridge: RTM_DELNEIGH with unconfigured "
 920                                 "vlan %d on port %s\n", vid, dev->name);
 921                         return -EINVAL;
 922                 }
 923
 924                 err = __br_fdb_delete(p, addr, vid);
 925         } else {
 926                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 927                         err = __br_fdb_delete(p, addr, 0);
 928                         goto out;
 929                 }
 930
 931                 /* We have vlans configured on this port and user didn't
 932                  * specify a VLAN.  To be nice, add/update entry for every
 933                  * vlan on this port.
 934                  */
 935                 err = -ENOENT;
 936                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 937                         err &= __br_fdb_delete(p, addr, vid);
 938                 }
 939         }
 940 out:
 941         return err;
 942 }
 943
 944 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
 945 {
 946         struct net_bridge_fdb_entry *fdb, *tmp;
 947         int i;
 948         int err;
 949
 950         ASSERT_RTNL();
 951
 952         for (i = 0; i < BR_HASH_SIZE; i++) {
 953                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
 954                         /* We only care for static entries */
 955                         if (!fdb->is_static)
 956                                 continue;
 957
 958                         err = dev_uc_add(p->dev, fdb->addr.addr);
 959                         if (err)
 960                                 goto rollback;
 961                 }
 962         }
 963         return 0;
 964
 965 rollback:
 966         for (i = 0; i < BR_HASH_SIZE; i++) {
 967                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
 968                         /* If we reached the fdb that failed, we can stop */
 969                         if (tmp == fdb)
 970                                 break;
 971
 972                         /* We only care for static entries */
 973                         if (!tmp->is_static)
 974                                 continue;
 975
 976                         dev_uc_del(p->dev, tmp->addr.addr);
 977                 }
 978         }
 979         return err;
 980 }
 981
 982 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
 983 {
 984         struct net_bridge_fdb_entry *fdb;
 985         int i;
 986
 987         ASSERT_RTNL();
 988
 989         for (i = 0; i < BR_HASH_SIZE; i++) {
 990                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
 991                         /* We only care for static entries */
 992                         if (!fdb->is_static)
 993                                 continue;
 994
 995                         dev_uc_del(p->dev, fdb->addr.addr);
 996                 }
 997         }
 998 }