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_addr(struct net_bridge *br, const unsigned char *addr)
  94 {
  95         int err;
  96         struct net_bridge_port *p;
  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_continue_reverse(p, &br->port_list, list) {
 111                 if (!br_promisc_port(p))
 112                         dev_uc_del(p->dev, addr);
 113         }
 114 }
 115
 116 /* When a static FDB entry is deleted, the HW address from that entry is
 117  * also removed from the bridge private HW address list and updates all
 118  * the ports with needed information.
 119  * Called under RTNL.
 120  */
 121 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 122 {
 123         struct net_bridge_port *p;
 124
 125         ASSERT_RTNL();
 126
 127         list_for_each_entry(p, &br->port_list, list) {
 128                 if (!br_promisc_port(p))
 129                         dev_uc_del(p->dev, addr);
 130         }
 131 }
 132
 133 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 134 {
 135         if (f->is_static)
 136                 fdb_del_hw_addr(br, f->addr.addr);
 137
 138         hlist_del_rcu(&f->hlist);
 139         fdb_notify(br, f, RTM_DELNEIGH);
 140         call_rcu(&f->rcu, fdb_rcu_free);
 141 }
 142
 143 /* Delete a local entry if no other port had the same address. */
 144 static void fdb_delete_local(struct net_bridge *br,
 145                              const struct net_bridge_port *p,
 146                              struct net_bridge_fdb_entry *f)
 147 {
 148         const unsigned char *addr = f->addr.addr;
 149         u16 vid = f->vlan_id;
 150         struct net_bridge_port *op;
 151
 152         /* Maybe another port has same hw addr? */
 153         list_for_each_entry(op, &br->port_list, list) {
 154                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 155                     (!vid || nbp_vlan_find(op, vid))) {
 156                         f->dst = op;
 157                         f->added_by_user = 0;
 158                         return;
 159                 }
 160         }
 161
 162         /* Maybe bridge device has same hw addr? */
 163         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 164             (!vid || br_vlan_find(br, vid))) {
 165                 f->dst = NULL;
 166                 f->added_by_user = 0;
 167                 return;
 168         }
 169
 170         fdb_delete(br, f);
 171 }
 172
 173 void br_fdb_find_delete_local(struct net_bridge *br,
 174                               const struct net_bridge_port *p,
 175                               const unsigned char *addr, u16 vid)
 176 {
 177         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 178         struct net_bridge_fdb_entry *f;
 179
 180         spin_lock_bh(&br->hash_lock);
 181         f = fdb_find(head, addr, vid);
 182         if (f && f->is_local && !f->added_by_user && f->dst == p)
 183                 fdb_delete_local(br, p, f);
 184         spin_unlock_bh(&br->hash_lock);
 185 }
 186
 187 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 188 {
 189         struct net_bridge *br = p->br;
 190         struct net_port_vlans *pv = nbp_get_vlan_info(p);
 191         bool no_vlan = !pv;
 192         int i;
 193         u16 vid;
 194
 195         spin_lock_bh(&br->hash_lock);
 196
 197         /* Search all chains since old address/hash is unknown */
 198         for (i = 0; i < BR_HASH_SIZE; i++) {
 199                 struct hlist_node *h;
 200                 hlist_for_each(h, &br->hash[i]) {
 201                         struct net_bridge_fdb_entry *f;
 202
 203                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 204                         if (f->dst == p && f->is_local && !f->added_by_user) {
 205                                 /* delete old one */
 206                                 fdb_delete_local(br, p, f);
 207
 208                                 /* if this port has no vlan information
 209                                  * configured, we can safely be done at
 210                                  * this point.
 211                                  */
 212                                 if (no_vlan)
 213                                         goto insert;
 214                         }
 215                 }
 216         }
 217
 218 insert:
 219         /* insert new address,  may fail if invalid address or dup. */
 220         fdb_insert(br, p, newaddr, 0);
 221
 222         if (no_vlan)
 223                 goto done;
 224
 225         /* Now add entries for every VLAN configured on the port.
 226          * This function runs under RTNL so the bitmap will not change
 227          * from under us.
 228          */
 229         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 230                 fdb_insert(br, p, newaddr, vid);
 231
 232 done:
 233         spin_unlock_bh(&br->hash_lock);
 234 }
 235
 236 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 237 {
 238         struct net_bridge_fdb_entry *f;
 239         struct net_port_vlans *pv;
 240         u16 vid = 0;
 241
 242         spin_lock_bh(&br->hash_lock);
 243
 244         /* If old entry was unassociated with any port, then delete it. */
 245         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 246         if (f && f->is_local && !f->dst)
 247                 fdb_delete_local(br, NULL, f);
 248
 249         fdb_insert(br, NULL, newaddr, 0);
 250
 251         /* Now remove and add entries for every VLAN configured on the
 252          * bridge.  This function runs under RTNL so the bitmap will not
 253          * change from under us.
 254          */
 255         pv = br_get_vlan_info(br);
 256         if (!pv)
 257                 goto out;
 258
 259         for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
 260                 f = __br_fdb_get(br, br->dev->dev_addr, vid);
 261                 if (f && f->is_local && !f->dst)
 262                         fdb_delete_local(br, NULL, f);
 263                 fdb_insert(br, NULL, newaddr, vid);
 264         }
 265 out:
 266         spin_unlock_bh(&br->hash_lock);
 267 }
 268
 269 void br_fdb_cleanup(unsigned long _data)
 270 {
 271         struct net_bridge *br = (struct net_bridge *)_data;
 272         unsigned long delay = hold_time(br);
 273         unsigned long next_timer = jiffies + br->ageing_time;
 274         int i;
 275
 276         spin_lock(&br->hash_lock);
 277         for (i = 0; i < BR_HASH_SIZE; i++) {
 278                 struct net_bridge_fdb_entry *f;
 279                 struct hlist_node *n;
 280
 281                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 282                         unsigned long this_timer;
 283                         if (f->is_static)
 284                                 continue;
 285                         this_timer = f->updated + delay;
 286                         if (time_before_eq(this_timer, jiffies))
 287                                 fdb_delete(br, f);
 288                         else if (time_before(this_timer, next_timer))
 289                                 next_timer = this_timer;
 290                 }
 291         }
 292         spin_unlock(&br->hash_lock);
 293
 294         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 295 }
 296
 297 /* Completely flush all dynamic entries in forwarding database.*/
 298 void br_fdb_flush(struct net_bridge *br)
 299 {
 300         int i;
 301
 302         spin_lock_bh(&br->hash_lock);
 303         for (i = 0; i < BR_HASH_SIZE; i++) {
 304                 struct net_bridge_fdb_entry *f;
 305                 struct hlist_node *n;
 306                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 307                         if (!f->is_static)
 308                                 fdb_delete(br, f);
 309                 }
 310         }
 311         spin_unlock_bh(&br->hash_lock);
 312 }
 313
 314 /* Flush all entries referring to a specific port.
 315  * if do_all is set also flush static entries
 316  */
 317 void br_fdb_delete_by_port(struct net_bridge *br,
 318                            const struct net_bridge_port *p,
 319                            int do_all)
 320 {
 321         int i;
 322
 323         spin_lock_bh(&br->hash_lock);
 324         for (i = 0; i < BR_HASH_SIZE; i++) {
 325                 struct hlist_node *h, *g;
 326
 327                 hlist_for_each_safe(h, g, &br->hash[i]) {
 328                         struct net_bridge_fdb_entry *f
 329                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 330                         if (f->dst != p)
 331                                 continue;
 332
 333                         if (f->is_static && !do_all)
 334                                 continue;
 335
 336                         if (f->is_local)
 337                                 fdb_delete_local(br, p, f);
 338                         else
 339                                 fdb_delete(br, f);
 340                 }
 341         }
 342         spin_unlock_bh(&br->hash_lock);
 343 }
 344
 345 /* No locking or refcounting, assumes caller has rcu_read_lock */
 346 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 347                                           const unsigned char *addr,
 348                                           __u16 vid)
 349 {
 350         struct net_bridge_fdb_entry *fdb;
 351
 352         hlist_for_each_entry_rcu(fdb,
 353                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 354                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 355                     fdb->vlan_id == vid) {
 356                         if (unlikely(has_expired(br, fdb)))
 357                                 break;
 358                         return fdb;
 359                 }
 360         }
 361
 362         return NULL;
 363 }
 364
 365 #if IS_ENABLED(CONFIG_ATM_LANE)
 366 /* Interface used by ATM LANE hook to test
 367  * if an addr is on some other bridge port */
 368 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 369 {
 370         struct net_bridge_fdb_entry *fdb;
 371         struct net_bridge_port *port;
 372         int ret;
 373
 374         rcu_read_lock();
 375         port = br_port_get_rcu(dev);
 376         if (!port)
 377                 ret = 0;
 378         else {
 379                 fdb = __br_fdb_get(port->br, addr, 0);
 380                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 381                         fdb->dst->state == BR_STATE_FORWARDING;
 382         }
 383         rcu_read_unlock();
 384
 385         return ret;
 386 }
 387 #endif /* CONFIG_ATM_LANE */
 388
 389 /*
 390  * Fill buffer with forwarding table records in
 391  * the API format.
 392  */
 393 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 394                    unsigned long maxnum, unsigned long skip)
 395 {
 396         struct __fdb_entry *fe = buf;
 397         int i, num = 0;
 398         struct net_bridge_fdb_entry *f;
 399
 400         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 401
 402         rcu_read_lock();
 403         for (i = 0; i < BR_HASH_SIZE; i++) {
 404                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 405                         if (num >= maxnum)
 406                                 goto out;
 407
 408                         if (has_expired(br, f))
 409                                 continue;
 410
 411                         /* ignore pseudo entry for local MAC address */
 412                         if (!f->dst)
 413                                 continue;
 414
 415                         if (skip) {
 416                                 --skip;
 417                                 continue;
 418                         }
 419
 420                         /* convert from internal format to API */
 421                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 422
 423                         /* due to ABI compat need to split into hi/lo */
 424                         fe->port_no = f->dst->port_no;
 425                         fe->port_hi = f->dst->port_no >> 8;
 426
 427                         fe->is_local = f->is_local;
 428                         if (!f->is_static)
 429                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 430                         ++fe;
 431                         ++num;
 432                 }
 433         }
 434
 435  out:
 436         rcu_read_unlock();
 437
 438         return num;
 439 }
 440
 441 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 442                                              const unsigned char *addr,
 443                                              __u16 vid)
 444 {
 445         struct net_bridge_fdb_entry *fdb;
 446
 447         hlist_for_each_entry(fdb, head, hlist) {
 448                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 449                     fdb->vlan_id == vid)
 450                         return fdb;
 451         }
 452         return NULL;
 453 }
 454
 455 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 456                                                  const unsigned char *addr,
 457                                                  __u16 vid)
 458 {
 459         struct net_bridge_fdb_entry *fdb;
 460
 461         hlist_for_each_entry_rcu(fdb, head, hlist) {
 462                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 463                     fdb->vlan_id == vid)
 464                         return fdb;
 465         }
 466         return NULL;
 467 }
 468
 469 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 470                                                struct net_bridge_port *source,
 471                                                const unsigned char *addr,
 472                                                __u16 vid)
 473 {
 474         struct net_bridge_fdb_entry *fdb;
 475
 476         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 477         if (fdb) {
 478                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 479                 fdb->dst = source;
 480                 fdb->vlan_id = vid;
 481                 fdb->is_local = 0;
 482                 fdb->is_static = 0;
 483                 fdb->added_by_user = 0;
 484                 fdb->added_by_external_learn = 0;
 485                 fdb->updated = fdb->used = jiffies;
 486                 hlist_add_head_rcu(&fdb->hlist, head);
 487         }
 488         return fdb;
 489 }
 490
 491 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 492                   const unsigned char *addr, u16 vid)
 493 {
 494         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 495         struct net_bridge_fdb_entry *fdb;
 496
 497         if (!is_valid_ether_addr(addr))
 498                 return -EINVAL;
 499
 500         fdb = fdb_find(head, addr, vid);
 501         if (fdb) {
 502                 /* it is okay to have multiple ports with same
 503                  * address, just use the first one.
 504                  */
 505                 if (fdb->is_local)
 506                         return 0;
 507                 br_warn(br, "adding interface %s with same address "
 508                        "as a received packet\n",
 509                        source ? source->dev->name : br->dev->name);
 510                 fdb_delete(br, fdb);
 511         }
 512
 513         fdb = fdb_create(head, source, addr, vid);
 514         if (!fdb)
 515                 return -ENOMEM;
 516
 517         fdb->is_local = fdb->is_static = 1;
 518         fdb_add_hw_addr(br, addr);
 519         fdb_notify(br, fdb, RTM_NEWNEIGH);
 520         return 0;
 521 }
 522
 523 /* Add entry for local address of interface */
 524 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 525                   const unsigned char *addr, u16 vid)
 526 {
 527         int ret;
 528
 529         spin_lock_bh(&br->hash_lock);
 530         ret = fdb_insert(br, source, addr, vid);
 531         spin_unlock_bh(&br->hash_lock);
 532         return ret;
 533 }
 534
 535 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 536                    const unsigned char *addr, u16 vid, bool added_by_user)
 537 {
 538         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 539         struct net_bridge_fdb_entry *fdb;
 540         bool fdb_modified = false;
 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                         if (unlikely(source != fdb->dst)) {
 562                                 fdb->dst = source;
 563                                 fdb_modified = true;
 564                         }
 565                         fdb->updated = jiffies;
 566                         if (unlikely(added_by_user))
 567                                 fdb->added_by_user = 1;
 568                         if (unlikely(fdb_modified))
 569                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 570                 }
 571         } else {
 572                 spin_lock(&br->hash_lock);
 573                 if (likely(!fdb_find(head, addr, vid))) {
 574                         fdb = fdb_create(head, source, addr, vid);
 575                         if (fdb) {
 576                                 if (unlikely(added_by_user))
 577                                         fdb->added_by_user = 1;
 578                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 579                         }
 580                 }
 581                 /* else  we lose race and someone else inserts
 582                  * it first, don't bother updating
 583                  */
 584                 spin_unlock(&br->hash_lock);
 585         }
 586 }
 587
 588 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
 589 {
 590         if (fdb->is_local)
 591                 return NUD_PERMANENT;
 592         else if (fdb->is_static)
 593                 return NUD_NOARP;
 594         else if (has_expired(fdb->dst->br, fdb))
 595                 return NUD_STALE;
 596         else
 597                 return NUD_REACHABLE;
 598 }
 599
 600 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 601                          const struct net_bridge_fdb_entry *fdb,
 602                          u32 portid, u32 seq, int type, unsigned int flags)
 603 {
 604         unsigned long now = jiffies;
 605         struct nda_cacheinfo ci;
 606         struct nlmsghdr *nlh;
 607         struct ndmsg *ndm;
 608
 609         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 610         if (nlh == NULL)
 611                 return -EMSGSIZE;
 612
 613         ndm = nlmsg_data(nlh);
 614         ndm->ndm_family  = AF_BRIDGE;
 615         ndm->ndm_pad1    = 0;
 616         ndm->ndm_pad2    = 0;
 617         ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 618         ndm->ndm_type    = 0;
 619         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 620         ndm->ndm_state   = fdb_to_nud(fdb);
 621
 622         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 623                 goto nla_put_failure;
 624         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 625                 goto nla_put_failure;
 626         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 627         ci.ndm_confirmed = 0;
 628         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 629         ci.ndm_refcnt    = 0;
 630         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 631                 goto nla_put_failure;
 632
 633         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 634                 goto nla_put_failure;
 635
 636         nlmsg_end(skb, nlh);
 637         return 0;
 638
 639 nla_put_failure:
 640         nlmsg_cancel(skb, nlh);
 641         return -EMSGSIZE;
 642 }
 643
 644 static inline size_t fdb_nlmsg_size(void)
 645 {
 646         return NLMSG_ALIGN(sizeof(struct ndmsg))
 647                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 648                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 649                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 650                 + nla_total_size(sizeof(struct nda_cacheinfo));
 651 }
 652
 653 static void fdb_notify(struct net_bridge *br,
 654                        const struct net_bridge_fdb_entry *fdb, int type)
 655 {
 656         struct net *net = dev_net(br->dev);
 657         struct sk_buff *skb;
 658         int err = -ENOBUFS;
 659
 660         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 661         if (skb == NULL)
 662                 goto errout;
 663
 664         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 665         if (err < 0) {
 666                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 667                 WARN_ON(err == -EMSGSIZE);
 668                 kfree_skb(skb);
 669                 goto errout;
 670         }
 671         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 672         return;
 673 errout:
 674         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 675 }
 676
 677 /* Dump information about entries, in response to GETNEIGH */
 678 int br_fdb_dump(struct sk_buff *skb,
 679                 struct netlink_callback *cb,
 680                 struct net_device *dev,
 681                 struct net_device *filter_dev,
 682                 int idx)
 683 {
 684         struct net_bridge *br = netdev_priv(dev);
 685         int i;
 686
 687         if (!(dev->priv_flags & IFF_EBRIDGE))
 688                 goto out;
 689
 690         if (!filter_dev)
 691                 idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 692
 693         for (i = 0; i < BR_HASH_SIZE; i++) {
 694                 struct net_bridge_fdb_entry *f;
 695
 696                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 697                         if (idx < cb->args[0])
 698                                 goto skip;
 699
 700                         if (filter_dev &&
 701                             (!f->dst || f->dst->dev != filter_dev)) {
 702                                 if (filter_dev != dev)
 703                                         goto skip;
 704                                 /* !f->dst is a special case for bridge
 705                                  * It means the MAC belongs to the bridge
 706                                  * Therefore need a little more filtering
 707                                  * we only want to dump the !f->dst case
 708                                  */
 709                                 if (f->dst)
 710                                         goto skip;
 711                         }
 712                         if (!filter_dev && f->dst)
 713                                 goto skip;
 714
 715                         if (fdb_fill_info(skb, br, f,
 716                                           NETLINK_CB(cb->skb).portid,
 717                                           cb->nlh->nlmsg_seq,
 718                                           RTM_NEWNEIGH,
 719                                           NLM_F_MULTI) < 0)
 720                                 break;
 721 skip:
 722                         ++idx;
 723                 }
 724         }
 725
 726 out:
 727         return idx;
 728 }
 729
 730 /* Update (create or replace) forwarding database entry */
 731 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 732                          __u16 state, __u16 flags, __u16 vid)
 733 {
 734         struct net_bridge *br = source->br;
 735         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 736         struct net_bridge_fdb_entry *fdb;
 737         bool modified = false;
 738
 739         fdb = fdb_find(head, addr, vid);
 740         if (fdb == NULL) {
 741                 if (!(flags & NLM_F_CREATE))
 742                         return -ENOENT;
 743
 744                 fdb = fdb_create(head, source, addr, vid);
 745                 if (!fdb)
 746                         return -ENOMEM;
 747
 748                 modified = true;
 749         } else {
 750                 if (flags & NLM_F_EXCL)
 751                         return -EEXIST;
 752
 753                 if (fdb->dst != source) {
 754                         fdb->dst = source;
 755                         modified = true;
 756                 }
 757         }
 758
 759         if (fdb_to_nud(fdb) != state) {
 760                 if (state & NUD_PERMANENT) {
 761                         fdb->is_local = 1;
 762                         if (!fdb->is_static) {
 763                                 fdb->is_static = 1;
 764                                 fdb_add_hw_addr(br, addr);
 765                         }
 766                 } else if (state & NUD_NOARP) {
 767                         fdb->is_local = 0;
 768                         if (!fdb->is_static) {
 769                                 fdb->is_static = 1;
 770                                 fdb_add_hw_addr(br, addr);
 771                         }
 772                 } else {
 773                         fdb->is_local = 0;
 774                         if (fdb->is_static) {
 775                                 fdb->is_static = 0;
 776                                 fdb_del_hw_addr(br, addr);
 777                         }
 778                 }
 779
 780                 modified = true;
 781         }
 782         fdb->added_by_user = 1;
 783
 784         fdb->used = jiffies;
 785         if (modified) {
 786                 fdb->updated = jiffies;
 787                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 788         }
 789
 790         return 0;
 791 }
 792
 793 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 794                const unsigned char *addr, u16 nlh_flags, u16 vid)
 795 {
 796         int err = 0;
 797
 798         if (ndm->ndm_flags & NTF_USE) {
 799                 rcu_read_lock();
 800                 br_fdb_update(p->br, p, addr, vid, true);
 801                 rcu_read_unlock();
 802         } else {
 803                 spin_lock_bh(&p->br->hash_lock);
 804                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 805                                     nlh_flags, vid);
 806                 spin_unlock_bh(&p->br->hash_lock);
 807         }
 808
 809         return err;
 810 }
 811
 812 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 813 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 814                struct net_device *dev,
 815                const unsigned char *addr, u16 vid, u16 nlh_flags)
 816 {
 817         struct net_bridge_port *p;
 818         int err = 0;
 819         struct net_port_vlans *pv;
 820
 821         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 822                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 823                 return -EINVAL;
 824         }
 825
 826         if (is_zero_ether_addr(addr)) {
 827                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 828                 return -EINVAL;
 829         }
 830
 831         p = br_port_get_rtnl(dev);
 832         if (p == NULL) {
 833                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 834                         dev->name);
 835                 return -EINVAL;
 836         }
 837
 838         pv = nbp_get_vlan_info(p);
 839         if (vid) {
 840                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 841                         pr_info("bridge: RTM_NEWNEIGH with unconfigured "
 842                                 "vlan %d on port %s\n", vid, dev->name);
 843                         return -EINVAL;
 844                 }
 845
 846                 /* VID was specified, so use it. */
 847                 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 848         } else {
 849                 err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 850                 if (err || !pv)
 851                         goto out;
 852
 853                 /* We have vlans configured on this port and user didn't
 854                  * specify a VLAN.  To be nice, add/update entry for every
 855                  * vlan on this port.
 856                  */
 857                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 858                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 859                         if (err)
 860                                 goto out;
 861                 }
 862         }
 863
 864 out:
 865         return err;
 866 }
 867
 868 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
 869 {
 870         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 871         struct net_bridge_fdb_entry *fdb;
 872
 873         fdb = fdb_find(head, addr, vlan);
 874         if (!fdb)
 875                 return -ENOENT;
 876
 877         fdb_delete(br, fdb);
 878         return 0;
 879 }
 880
 881 static int __br_fdb_delete(struct net_bridge_port *p,
 882                            const unsigned char *addr, u16 vid)
 883 {
 884         int err;
 885
 886         spin_lock_bh(&p->br->hash_lock);
 887         err = fdb_delete_by_addr(p->br, addr, vid);
 888         spin_unlock_bh(&p->br->hash_lock);
 889
 890         return err;
 891 }
 892
 893 /* Remove neighbor entry with RTM_DELNEIGH */
 894 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 895                   struct net_device *dev,
 896                   const unsigned char *addr, u16 vid)
 897 {
 898         struct net_bridge_port *p;
 899         int err;
 900         struct net_port_vlans *pv;
 901
 902         p = br_port_get_rtnl(dev);
 903         if (p == NULL) {
 904                 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 905                         dev->name);
 906                 return -EINVAL;
 907         }
 908
 909         pv = nbp_get_vlan_info(p);
 910         if (vid) {
 911                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 912                         pr_info("bridge: RTM_DELNEIGH with unconfigured "
 913                                 "vlan %d on port %s\n", vid, dev->name);
 914                         return -EINVAL;
 915                 }
 916
 917                 err = __br_fdb_delete(p, addr, vid);
 918         } else {
 919                 err = -ENOENT;
 920                 err &= __br_fdb_delete(p, addr, 0);
 921                 if (!pv)
 922                         goto out;
 923
 924                 /* We have vlans configured on this port and user didn't
 925                  * specify a VLAN.  To be nice, add/update entry for every
 926                  * vlan on this port.
 927                  */
 928                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 929                         err &= __br_fdb_delete(p, addr, vid);
 930                 }
 931         }
 932 out:
 933         return err;
 934 }
 935
 936 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
 937 {
 938         struct net_bridge_fdb_entry *fdb, *tmp;
 939         int i;
 940         int err;
 941
 942         ASSERT_RTNL();
 943
 944         for (i = 0; i < BR_HASH_SIZE; i++) {
 945                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
 946                         /* We only care for static entries */
 947                         if (!fdb->is_static)
 948                                 continue;
 949
 950                         err = dev_uc_add(p->dev, fdb->addr.addr);
 951                         if (err)
 952                                 goto rollback;
 953                 }
 954         }
 955         return 0;
 956
 957 rollback:
 958         for (i = 0; i < BR_HASH_SIZE; i++) {
 959                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
 960                         /* If we reached the fdb that failed, we can stop */
 961                         if (tmp == fdb)
 962                                 break;
 963
 964                         /* We only care for static entries */
 965                         if (!tmp->is_static)
 966                                 continue;
 967
 968                         dev_uc_del(p->dev, tmp->addr.addr);
 969                 }
 970         }
 971         return err;
 972 }
 973
 974 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
 975 {
 976         struct net_bridge_fdb_entry *fdb;
 977         int i;
 978
 979         ASSERT_RTNL();
 980
 981         for (i = 0; i < BR_HASH_SIZE; i++) {
 982                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
 983                         /* We only care for static entries */
 984                         if (!fdb->is_static)
 985                                 continue;
 986
 987                         dev_uc_del(p->dev, fdb->addr.addr);
 988                 }
 989         }
 990 }
 991
 992 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
 993                               const unsigned char *addr, u16 vid)
 994 {
 995         struct hlist_head *head;
 996         struct net_bridge_fdb_entry *fdb;
 997         int err = 0;
 998
 999         ASSERT_RTNL();
1000         spin_lock_bh(&br->hash_lock);
1001
1002         head = &br->hash[br_mac_hash(addr, vid)];
1003         fdb = fdb_find(head, addr, vid);
1004         if (!fdb) {
1005                 fdb = fdb_create(head, p, addr, vid);
1006                 if (!fdb) {
1007                         err = -ENOMEM;
1008                         goto err_unlock;
1009                 }
1010                 fdb->added_by_external_learn = 1;
1011                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1012         } else if (fdb->added_by_external_learn) {
1013                 /* Refresh entry */
1014                 fdb->updated = fdb->used = jiffies;
1015         } else if (!fdb->added_by_user) {
1016                 /* Take over SW learned entry */
1017                 fdb->added_by_external_learn = 1;
1018                 fdb->updated = jiffies;
1019                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1020         }
1021
1022 err_unlock:
1023         spin_unlock_bh(&br->hash_lock);
1024
1025         return err;
1026 }
1027
1028 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1029                               const unsigned char *addr, u16 vid)
1030 {
1031         struct hlist_head *head;
1032         struct net_bridge_fdb_entry *fdb;
1033         int err = 0;
1034
1035         ASSERT_RTNL();
1036         spin_lock_bh(&br->hash_lock);
1037
1038         head = &br->hash[br_mac_hash(addr, vid)];
1039         fdb = fdb_find(head, addr, vid);
1040         if (fdb && fdb->added_by_external_learn)
1041                 fdb_delete(br, fdb);
1042         else
1043                 err = -ENOENT;
1044
1045         spin_unlock_bh(&br->hash_lock);
1046
1047         return err;
1048 }