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 <trace/events/bridge.h>
  29 #include "br_private.h"
  30
  31 static struct kmem_cache *br_fdb_cache __read_mostly;
  32 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  33                       const unsigned char *addr, u16 vid);
  34 static void fdb_notify(struct net_bridge *br,
  35                        const struct net_bridge_fdb_entry *, int);
  36
  37 static u32 fdb_salt __read_mostly;
  38
  39 int __init br_fdb_init(void)
  40 {
  41         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  42                                          sizeof(struct net_bridge_fdb_entry),
  43                                          0,
  44                                          SLAB_HWCACHE_ALIGN, NULL);
  45         if (!br_fdb_cache)
  46                 return -ENOMEM;
  47
  48         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  49         return 0;
  50 }
  51
  52 void br_fdb_fini(void)
  53 {
  54         kmem_cache_destroy(br_fdb_cache);
  55 }
  56
  57
  58 /* if topology_changing then use forward_delay (default 15 sec)
  59  * otherwise keep longer (default 5 minutes)
  60  */
  61 static inline unsigned long hold_time(const struct net_bridge *br)
  62 {
  63         return br->topology_change ? br->forward_delay : br->ageing_time;
  64 }
  65
  66 static inline int has_expired(const struct net_bridge *br,
  67                                   const struct net_bridge_fdb_entry *fdb)
  68 {
  69         return !fdb->is_static && !fdb->added_by_external_learn &&
  70                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  71 }
  72
  73 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  74 {
  75         /* use 1 byte of OUI and 3 bytes of NIC */
  76         u32 key = get_unaligned((u32 *)(mac + 2));
  77         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  78 }
  79
  80 static void fdb_rcu_free(struct rcu_head *head)
  81 {
  82         struct net_bridge_fdb_entry *ent
  83                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  84         kmem_cache_free(br_fdb_cache, ent);
  85 }
  86
  87 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
  88                                                  const unsigned char *addr,
  89                                                  __u16 vid)
  90 {
  91         struct net_bridge_fdb_entry *f;
  92
  93         WARN_ON_ONCE(!rcu_read_lock_held());
  94
  95         hlist_for_each_entry_rcu(f, head, hlist)
  96                 if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
  97                         break;
  98
  99         return f;
 100 }
 101
 102 /* requires bridge hash_lock */
 103 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 104                                                 const unsigned char *addr,
 105                                                 __u16 vid)
 106 {
 107         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 108         struct net_bridge_fdb_entry *fdb;
 109
 110         lockdep_assert_held_once(&br->hash_lock);
 111
 112         rcu_read_lock();
 113         fdb = fdb_find_rcu(head, addr, vid);
 114         rcu_read_unlock();
 115
 116         return fdb;
 117 }
 118
 119 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 120                                              const unsigned char *addr,
 121                                              __u16 vid)
 122 {
 123         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 124
 125         return fdb_find_rcu(head, addr, vid);
 126 }
 127
 128 /* When a static FDB entry is added, the mac address from the entry is
 129  * added to the bridge private HW address list and all required ports
 130  * are then updated with the new information.
 131  * Called under RTNL.
 132  */
 133 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 134 {
 135         int err;
 136         struct net_bridge_port *p;
 137
 138         ASSERT_RTNL();
 139
 140         list_for_each_entry(p, &br->port_list, list) {
 141                 if (!br_promisc_port(p)) {
 142                         err = dev_uc_add(p->dev, addr);
 143                         if (err)
 144                                 goto undo;
 145                 }
 146         }
 147
 148         return;
 149 undo:
 150         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 151                 if (!br_promisc_port(p))
 152                         dev_uc_del(p->dev, addr);
 153         }
 154 }
 155
 156 /* When a static FDB entry is deleted, the HW address from that entry is
 157  * also removed from the bridge private HW address list and updates all
 158  * the ports with needed information.
 159  * Called under RTNL.
 160  */
 161 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 162 {
 163         struct net_bridge_port *p;
 164
 165         ASSERT_RTNL();
 166
 167         list_for_each_entry(p, &br->port_list, list) {
 168                 if (!br_promisc_port(p))
 169                         dev_uc_del(p->dev, addr);
 170         }
 171 }
 172
 173 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 174 {
 175         trace_fdb_delete(br, f);
 176
 177         if (f->is_static)
 178                 fdb_del_hw_addr(br, f->addr.addr);
 179
 180         hlist_del_init_rcu(&f->hlist);
 181         fdb_notify(br, f, RTM_DELNEIGH);
 182         call_rcu(&f->rcu, fdb_rcu_free);
 183 }
 184
 185 /* Delete a local entry if no other port had the same address. */
 186 static void fdb_delete_local(struct net_bridge *br,
 187                              const struct net_bridge_port *p,
 188                              struct net_bridge_fdb_entry *f)
 189 {
 190         const unsigned char *addr = f->addr.addr;
 191         struct net_bridge_vlan_group *vg;
 192         const struct net_bridge_vlan *v;
 193         struct net_bridge_port *op;
 194         u16 vid = f->vlan_id;
 195
 196         /* Maybe another port has same hw addr? */
 197         list_for_each_entry(op, &br->port_list, list) {
 198                 vg = nbp_vlan_group(op);
 199                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 200                     (!vid || br_vlan_find(vg, vid))) {
 201                         f->dst = op;
 202                         f->added_by_user = 0;
 203                         return;
 204                 }
 205         }
 206
 207         vg = br_vlan_group(br);
 208         v = br_vlan_find(vg, vid);
 209         /* Maybe bridge device has same hw addr? */
 210         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 211             (!vid || (v && br_vlan_should_use(v)))) {
 212                 f->dst = NULL;
 213                 f->added_by_user = 0;
 214                 return;
 215         }
 216
 217         fdb_delete(br, f);
 218 }
 219
 220 void br_fdb_find_delete_local(struct net_bridge *br,
 221                               const struct net_bridge_port *p,
 222                               const unsigned char *addr, u16 vid)
 223 {
 224         struct net_bridge_fdb_entry *f;
 225
 226         spin_lock_bh(&br->hash_lock);
 227         f = br_fdb_find(br, addr, vid);
 228         if (f && f->is_local && !f->added_by_user && f->dst == p)
 229                 fdb_delete_local(br, p, f);
 230         spin_unlock_bh(&br->hash_lock);
 231 }
 232
 233 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 234 {
 235         struct net_bridge_vlan_group *vg;
 236         struct net_bridge *br = p->br;
 237         struct net_bridge_vlan *v;
 238         int i;
 239
 240         spin_lock_bh(&br->hash_lock);
 241
 242         vg = nbp_vlan_group(p);
 243         /* Search all chains since old address/hash is unknown */
 244         for (i = 0; i < BR_HASH_SIZE; i++) {
 245                 struct hlist_node *h;
 246                 hlist_for_each(h, &br->hash[i]) {
 247                         struct net_bridge_fdb_entry *f;
 248
 249                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 250                         if (f->dst == p && f->is_local && !f->added_by_user) {
 251                                 /* delete old one */
 252                                 fdb_delete_local(br, p, f);
 253
 254                                 /* if this port has no vlan information
 255                                  * configured, we can safely be done at
 256                                  * this point.
 257                                  */
 258                                 if (!vg || !vg->num_vlans)
 259                                         goto insert;
 260                         }
 261                 }
 262         }
 263
 264 insert:
 265         /* insert new address,  may fail if invalid address or dup. */
 266         fdb_insert(br, p, newaddr, 0);
 267
 268         if (!vg || !vg->num_vlans)
 269                 goto done;
 270
 271         /* Now add entries for every VLAN configured on the port.
 272          * This function runs under RTNL so the bitmap will not change
 273          * from under us.
 274          */
 275         list_for_each_entry(v, &vg->vlan_list, vlist)
 276                 fdb_insert(br, p, newaddr, v->vid);
 277
 278 done:
 279         spin_unlock_bh(&br->hash_lock);
 280 }
 281
 282 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 283 {
 284         struct net_bridge_vlan_group *vg;
 285         struct net_bridge_fdb_entry *f;
 286         struct net_bridge_vlan *v;
 287
 288         spin_lock_bh(&br->hash_lock);
 289
 290         /* If old entry was unassociated with any port, then delete it. */
 291         f = br_fdb_find(br, br->dev->dev_addr, 0);
 292         if (f && f->is_local && !f->dst && !f->added_by_user)
 293                 fdb_delete_local(br, NULL, f);
 294
 295         fdb_insert(br, NULL, newaddr, 0);
 296         vg = br_vlan_group(br);
 297         if (!vg || !vg->num_vlans)
 298                 goto out;
 299         /* Now remove and add entries for every VLAN configured on the
 300          * bridge.  This function runs under RTNL so the bitmap will not
 301          * change from under us.
 302          */
 303         list_for_each_entry(v, &vg->vlan_list, vlist) {
 304                 if (!br_vlan_should_use(v))
 305                         continue;
 306                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 307                 if (f && f->is_local && !f->dst && !f->added_by_user)
 308                         fdb_delete_local(br, NULL, f);
 309                 fdb_insert(br, NULL, newaddr, v->vid);
 310         }
 311 out:
 312         spin_unlock_bh(&br->hash_lock);
 313 }
 314
 315 void br_fdb_cleanup(struct work_struct *work)
 316 {
 317         struct net_bridge *br = container_of(work, struct net_bridge,
 318                                              gc_work.work);
 319         unsigned long delay = hold_time(br);
 320         unsigned long work_delay = delay;
 321         unsigned long now = jiffies;
 322         int i;
 323
 324         for (i = 0; i < BR_HASH_SIZE; i++) {
 325                 struct net_bridge_fdb_entry *f;
 326                 struct hlist_node *n;
 327
 328                 if (!br->hash[i].first)
 329                         continue;
 330
 331                 spin_lock_bh(&br->hash_lock);
 332                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 333                         unsigned long this_timer;
 334
 335                         if (f->is_static)
 336                                 continue;
 337                         if (f->added_by_external_learn)
 338                                 continue;
 339                         this_timer = f->updated + delay;
 340                         if (time_after(this_timer, now))
 341                                 work_delay = min(work_delay, this_timer - now);
 342                         else
 343                                 fdb_delete(br, f);
 344                 }
 345                 spin_unlock_bh(&br->hash_lock);
 346                 cond_resched();
 347         }
 348
 349         /* Cleanup minimum 10 milliseconds apart */
 350         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 351         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 352 }
 353
 354 /* Completely flush all dynamic entries in forwarding database.*/
 355 void br_fdb_flush(struct net_bridge *br)
 356 {
 357         int i;
 358
 359         spin_lock_bh(&br->hash_lock);
 360         for (i = 0; i < BR_HASH_SIZE; i++) {
 361                 struct net_bridge_fdb_entry *f;
 362                 struct hlist_node *n;
 363                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 364                         if (!f->is_static)
 365                                 fdb_delete(br, f);
 366                 }
 367         }
 368         spin_unlock_bh(&br->hash_lock);
 369 }
 370
 371 /* Flush all entries referring to a specific port.
 372  * if do_all is set also flush static entries
 373  * if vid is set delete all entries that match the vlan_id
 374  */
 375 void br_fdb_delete_by_port(struct net_bridge *br,
 376                            const struct net_bridge_port *p,
 377                            u16 vid,
 378                            int do_all)
 379 {
 380         int i;
 381
 382         spin_lock_bh(&br->hash_lock);
 383         for (i = 0; i < BR_HASH_SIZE; i++) {
 384                 struct hlist_node *h, *g;
 385
 386                 hlist_for_each_safe(h, g, &br->hash[i]) {
 387                         struct net_bridge_fdb_entry *f
 388                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 389                         if (f->dst != p)
 390                                 continue;
 391
 392                         if (!do_all)
 393                                 if (f->is_static || (vid && f->vlan_id != vid))
 394                                         continue;
 395
 396                         if (f->is_local)
 397                                 fdb_delete_local(br, p, f);
 398                         else
 399                                 fdb_delete(br, f);
 400                 }
 401         }
 402         spin_unlock_bh(&br->hash_lock);
 403 }
 404
 405 #if IS_ENABLED(CONFIG_ATM_LANE)
 406 /* Interface used by ATM LANE hook to test
 407  * if an addr is on some other bridge port */
 408 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 409 {
 410         struct net_bridge_fdb_entry *fdb;
 411         struct net_bridge_port *port;
 412         int ret;
 413
 414         rcu_read_lock();
 415         port = br_port_get_rcu(dev);
 416         if (!port)
 417                 ret = 0;
 418         else {
 419                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 420                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 421                         fdb->dst->state == BR_STATE_FORWARDING;
 422         }
 423         rcu_read_unlock();
 424
 425         return ret;
 426 }
 427 #endif /* CONFIG_ATM_LANE */
 428
 429 /*
 430  * Fill buffer with forwarding table records in
 431  * the API format.
 432  */
 433 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 434                    unsigned long maxnum, unsigned long skip)
 435 {
 436         struct __fdb_entry *fe = buf;
 437         int i, num = 0;
 438         struct net_bridge_fdb_entry *f;
 439
 440         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 441
 442         rcu_read_lock();
 443         for (i = 0; i < BR_HASH_SIZE; i++) {
 444                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 445                         if (num >= maxnum)
 446                                 goto out;
 447
 448                         if (has_expired(br, f))
 449                                 continue;
 450
 451                         /* ignore pseudo entry for local MAC address */
 452                         if (!f->dst)
 453                                 continue;
 454
 455                         if (skip) {
 456                                 --skip;
 457                                 continue;
 458                         }
 459
 460                         /* convert from internal format to API */
 461                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 462
 463                         /* due to ABI compat need to split into hi/lo */
 464                         fe->port_no = f->dst->port_no;
 465                         fe->port_hi = f->dst->port_no >> 8;
 466
 467                         fe->is_local = f->is_local;
 468                         if (!f->is_static)
 469                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 470                         ++fe;
 471                         ++num;
 472                 }
 473         }
 474
 475  out:
 476         rcu_read_unlock();
 477
 478         return num;
 479 }
 480
 481 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 482                                                struct net_bridge_port *source,
 483                                                const unsigned char *addr,
 484                                                __u16 vid,
 485                                                unsigned char is_local,
 486                                                unsigned char is_static)
 487 {
 488         struct net_bridge_fdb_entry *fdb;
 489
 490         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 491         if (fdb) {
 492                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 493                 fdb->dst = source;
 494                 fdb->vlan_id = vid;
 495                 fdb->is_local = is_local;
 496                 fdb->is_static = is_static;
 497                 fdb->added_by_user = 0;
 498                 fdb->added_by_external_learn = 0;
 499                 fdb->offloaded = 0;
 500                 fdb->updated = fdb->used = jiffies;
 501                 hlist_add_head_rcu(&fdb->hlist, head);
 502         }
 503         return fdb;
 504 }
 505
 506 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 507                   const unsigned char *addr, u16 vid)
 508 {
 509         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 510         struct net_bridge_fdb_entry *fdb;
 511
 512         if (!is_valid_ether_addr(addr))
 513                 return -EINVAL;
 514
 515         fdb = br_fdb_find(br, addr, vid);
 516         if (fdb) {
 517                 /* it is okay to have multiple ports with same
 518                  * address, just use the first one.
 519                  */
 520                 if (fdb->is_local)
 521                         return 0;
 522                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 523                        source ? source->dev->name : br->dev->name, addr, vid);
 524                 fdb_delete(br, fdb);
 525         }
 526
 527         fdb = fdb_create(head, source, addr, vid, 1, 1);
 528         if (!fdb)
 529                 return -ENOMEM;
 530
 531         fdb_add_hw_addr(br, addr);
 532         fdb_notify(br, fdb, RTM_NEWNEIGH);
 533         return 0;
 534 }
 535
 536 /* Add entry for local address of interface */
 537 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 538                   const unsigned char *addr, u16 vid)
 539 {
 540         int ret;
 541
 542         spin_lock_bh(&br->hash_lock);
 543         ret = fdb_insert(br, source, addr, vid);
 544         spin_unlock_bh(&br->hash_lock);
 545         return ret;
 546 }
 547
 548 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 549                    const unsigned char *addr, u16 vid, bool added_by_user)
 550 {
 551         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 552         struct net_bridge_fdb_entry *fdb;
 553         bool fdb_modified = false;
 554
 555         /* some users want to always flood. */
 556         if (hold_time(br) == 0)
 557                 return;
 558
 559         /* ignore packets unless we are using this port */
 560         if (!(source->state == BR_STATE_LEARNING ||
 561               source->state == BR_STATE_FORWARDING))
 562                 return;
 563
 564         fdb = fdb_find_rcu(head, addr, vid);
 565         if (likely(fdb)) {
 566                 /* attempt to update an entry for a local interface */
 567                 if (unlikely(fdb->is_local)) {
 568                         if (net_ratelimit())
 569                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 570                                         source->dev->name, addr, vid);
 571                 } else {
 572                         unsigned long now = jiffies;
 573
 574                         /* fastpath: update of existing entry */
 575                         if (unlikely(source != fdb->dst)) {
 576                                 fdb->dst = source;
 577                                 fdb_modified = true;
 578                                 /* Take over HW learned entry */
 579                                 if (unlikely(fdb->added_by_external_learn))
 580                                         fdb->added_by_external_learn = 0;
 581                         }
 582                         if (now != fdb->updated)
 583                                 fdb->updated = now;
 584                         if (unlikely(added_by_user))
 585                                 fdb->added_by_user = 1;
 586                         if (unlikely(fdb_modified)) {
 587                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 588                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 589                         }
 590                 }
 591         } else {
 592                 spin_lock(&br->hash_lock);
 593                 if (likely(!fdb_find_rcu(head, addr, vid))) {
 594                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 595                         if (fdb) {
 596                                 if (unlikely(added_by_user))
 597                                         fdb->added_by_user = 1;
 598                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 599                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 600                         }
 601                 }
 602                 /* else  we lose race and someone else inserts
 603                  * it first, don't bother updating
 604                  */
 605                 spin_unlock(&br->hash_lock);
 606         }
 607 }
 608
 609 static int fdb_to_nud(const struct net_bridge *br,
 610                       const struct net_bridge_fdb_entry *fdb)
 611 {
 612         if (fdb->is_local)
 613                 return NUD_PERMANENT;
 614         else if (fdb->is_static)
 615                 return NUD_NOARP;
 616         else if (has_expired(br, fdb))
 617                 return NUD_STALE;
 618         else
 619                 return NUD_REACHABLE;
 620 }
 621
 622 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 623                          const struct net_bridge_fdb_entry *fdb,
 624                          u32 portid, u32 seq, int type, unsigned int flags)
 625 {
 626         unsigned long now = jiffies;
 627         struct nda_cacheinfo ci;
 628         struct nlmsghdr *nlh;
 629         struct ndmsg *ndm;
 630
 631         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 632         if (nlh == NULL)
 633                 return -EMSGSIZE;
 634
 635         ndm = nlmsg_data(nlh);
 636         ndm->ndm_family  = AF_BRIDGE;
 637         ndm->ndm_pad1    = 0;
 638         ndm->ndm_pad2    = 0;
 639         ndm->ndm_flags   = 0;
 640         ndm->ndm_type    = 0;
 641         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 642         ndm->ndm_state   = fdb_to_nud(br, fdb);
 643
 644         if (fdb->offloaded)
 645                 ndm->ndm_flags |= NTF_OFFLOADED;
 646         if (fdb->added_by_external_learn)
 647                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 648
 649         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 650                 goto nla_put_failure;
 651         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 652                 goto nla_put_failure;
 653         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 654         ci.ndm_confirmed = 0;
 655         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 656         ci.ndm_refcnt    = 0;
 657         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 658                 goto nla_put_failure;
 659
 660         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 661                 goto nla_put_failure;
 662
 663         nlmsg_end(skb, nlh);
 664         return 0;
 665
 666 nla_put_failure:
 667         nlmsg_cancel(skb, nlh);
 668         return -EMSGSIZE;
 669 }
 670
 671 static inline size_t fdb_nlmsg_size(void)
 672 {
 673         return NLMSG_ALIGN(sizeof(struct ndmsg))
 674                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 675                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 676                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 677                 + nla_total_size(sizeof(struct nda_cacheinfo));
 678 }
 679
 680 static void fdb_notify(struct net_bridge *br,
 681                        const struct net_bridge_fdb_entry *fdb, int type)
 682 {
 683         struct net *net = dev_net(br->dev);
 684         struct sk_buff *skb;
 685         int err = -ENOBUFS;
 686
 687         br_switchdev_fdb_notify(fdb, type);
 688
 689         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 690         if (skb == NULL)
 691                 goto errout;
 692
 693         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 694         if (err < 0) {
 695                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 696                 WARN_ON(err == -EMSGSIZE);
 697                 kfree_skb(skb);
 698                 goto errout;
 699         }
 700         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 701         return;
 702 errout:
 703         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 704 }
 705
 706 /* Dump information about entries, in response to GETNEIGH */
 707 int br_fdb_dump(struct sk_buff *skb,
 708                 struct netlink_callback *cb,
 709                 struct net_device *dev,
 710                 struct net_device *filter_dev,
 711                 int *idx)
 712 {
 713         struct net_bridge *br = netdev_priv(dev);
 714         int err = 0;
 715         int i;
 716
 717         if (!(dev->priv_flags & IFF_EBRIDGE))
 718                 goto out;
 719
 720         if (!filter_dev) {
 721                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 722                 if (err < 0)
 723                         goto out;
 724         }
 725
 726         for (i = 0; i < BR_HASH_SIZE; i++) {
 727                 struct net_bridge_fdb_entry *f;
 728
 729                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 730
 731                         if (*idx < cb->args[2])
 732                                 goto skip;
 733
 734                         if (filter_dev &&
 735                             (!f->dst || f->dst->dev != filter_dev)) {
 736                                 if (filter_dev != dev)
 737                                         goto skip;
 738                                 /* !f->dst is a special case for bridge
 739                                  * It means the MAC belongs to the bridge
 740                                  * Therefore need a little more filtering
 741                                  * we only want to dump the !f->dst case
 742                                  */
 743                                 if (f->dst)
 744                                         goto skip;
 745                         }
 746                         if (!filter_dev && f->dst)
 747                                 goto skip;
 748
 749                         err = fdb_fill_info(skb, br, f,
 750                                             NETLINK_CB(cb->skb).portid,
 751                                             cb->nlh->nlmsg_seq,
 752                                             RTM_NEWNEIGH,
 753                                             NLM_F_MULTI);
 754                         if (err < 0)
 755                                 goto out;
 756 skip:
 757                         *idx += 1;
 758                 }
 759         }
 760
 761 out:
 762         return err;
 763 }
 764
 765 /* Update (create or replace) forwarding database entry */
 766 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 767                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 768 {
 769         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 770         struct net_bridge_fdb_entry *fdb;
 771         bool modified = false;
 772
 773         /* If the port cannot learn allow only local and static entries */
 774         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 775             !(source->state == BR_STATE_LEARNING ||
 776               source->state == BR_STATE_FORWARDING))
 777                 return -EPERM;
 778
 779         if (!source && !(state & NUD_PERMANENT)) {
 780                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 781                         br->dev->name);
 782                 return -EINVAL;
 783         }
 784
 785         fdb = br_fdb_find(br, addr, vid);
 786         if (fdb == NULL) {
 787                 if (!(flags & NLM_F_CREATE))
 788                         return -ENOENT;
 789
 790                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 791                 if (!fdb)
 792                         return -ENOMEM;
 793
 794                 modified = true;
 795         } else {
 796                 if (flags & NLM_F_EXCL)
 797                         return -EEXIST;
 798
 799                 if (fdb->dst != source) {
 800                         fdb->dst = source;
 801                         modified = true;
 802                 }
 803         }
 804
 805         if (fdb_to_nud(br, fdb) != state) {
 806                 if (state & NUD_PERMANENT) {
 807                         fdb->is_local = 1;
 808                         if (!fdb->is_static) {
 809                                 fdb->is_static = 1;
 810                                 fdb_add_hw_addr(br, addr);
 811                         }
 812                 } else if (state & NUD_NOARP) {
 813                         fdb->is_local = 0;
 814                         if (!fdb->is_static) {
 815                                 fdb->is_static = 1;
 816                                 fdb_add_hw_addr(br, addr);
 817                         }
 818                 } else {
 819                         fdb->is_local = 0;
 820                         if (fdb->is_static) {
 821                                 fdb->is_static = 0;
 822                                 fdb_del_hw_addr(br, addr);
 823                         }
 824                 }
 825
 826                 modified = true;
 827         }
 828         fdb->added_by_user = 1;
 829
 830         fdb->used = jiffies;
 831         if (modified) {
 832                 fdb->updated = jiffies;
 833                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 834         }
 835
 836         return 0;
 837 }
 838
 839 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 840                         struct net_bridge_port *p, const unsigned char *addr,
 841                         u16 nlh_flags, u16 vid)
 842 {
 843         int err = 0;
 844
 845         if (ndm->ndm_flags & NTF_USE) {
 846                 if (!p) {
 847                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 848                                 br->dev->name);
 849                         return -EINVAL;
 850                 }
 851                 local_bh_disable();
 852                 rcu_read_lock();
 853                 br_fdb_update(br, p, addr, vid, true);
 854                 rcu_read_unlock();
 855                 local_bh_enable();
 856         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 857                 err = br_fdb_external_learn_add(br, p, addr, vid);
 858         } else {
 859                 spin_lock_bh(&br->hash_lock);
 860                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 861                                     nlh_flags, vid);
 862                 spin_unlock_bh(&br->hash_lock);
 863         }
 864
 865         return err;
 866 }
 867
 868 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 869 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 870                struct net_device *dev,
 871                const unsigned char *addr, u16 vid, u16 nlh_flags)
 872 {
 873         struct net_bridge_vlan_group *vg;
 874         struct net_bridge_port *p = NULL;
 875         struct net_bridge_vlan *v;
 876         struct net_bridge *br = NULL;
 877         int err = 0;
 878
 879         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 880
 881         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 882                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 883                 return -EINVAL;
 884         }
 885
 886         if (is_zero_ether_addr(addr)) {
 887                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 888                 return -EINVAL;
 889         }
 890
 891         if (dev->priv_flags & IFF_EBRIDGE) {
 892                 br = netdev_priv(dev);
 893                 vg = br_vlan_group(br);
 894         } else {
 895                 p = br_port_get_rtnl(dev);
 896                 if (!p) {
 897                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 898                                 dev->name);
 899                         return -EINVAL;
 900                 }
 901                 br = p->br;
 902                 vg = nbp_vlan_group(p);
 903         }
 904
 905         if (vid) {
 906                 v = br_vlan_find(vg, vid);
 907                 if (!v || !br_vlan_should_use(v)) {
 908                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 909                         return -EINVAL;
 910                 }
 911
 912                 /* VID was specified, so use it. */
 913                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 914         } else {
 915                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 916                 if (err || !vg || !vg->num_vlans)
 917                         goto out;
 918
 919                 /* We have vlans configured on this port and user didn't
 920                  * specify a VLAN.  To be nice, add/update entry for every
 921                  * vlan on this port.
 922                  */
 923                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 924                         if (!br_vlan_should_use(v))
 925                                 continue;
 926                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 927                         if (err)
 928                                 goto out;
 929                 }
 930         }
 931
 932 out:
 933         return err;
 934 }
 935
 936 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 937                                        const struct net_bridge_port *p,
 938                                        const u8 *addr, u16 vlan)
 939 {
 940         struct net_bridge_fdb_entry *fdb;
 941
 942         fdb = br_fdb_find(br, addr, vlan);
 943         if (!fdb || fdb->dst != p)
 944                 return -ENOENT;
 945
 946         fdb_delete(br, fdb);
 947
 948         return 0;
 949 }
 950
 951 static int __br_fdb_delete(struct net_bridge *br,
 952                            const struct net_bridge_port *p,
 953                            const unsigned char *addr, u16 vid)
 954 {
 955         int err;
 956
 957         spin_lock_bh(&br->hash_lock);
 958         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 959         spin_unlock_bh(&br->hash_lock);
 960
 961         return err;
 962 }
 963
 964 /* Remove neighbor entry with RTM_DELNEIGH */
 965 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 966                   struct net_device *dev,
 967                   const unsigned char *addr, u16 vid)
 968 {
 969         struct net_bridge_vlan_group *vg;
 970         struct net_bridge_port *p = NULL;
 971         struct net_bridge_vlan *v;
 972         struct net_bridge *br;
 973         int err;
 974
 975         if (dev->priv_flags & IFF_EBRIDGE) {
 976                 br = netdev_priv(dev);
 977                 vg = br_vlan_group(br);
 978         } else {
 979                 p = br_port_get_rtnl(dev);
 980                 if (!p) {
 981                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 982                                 dev->name);
 983                         return -EINVAL;
 984                 }
 985                 vg = nbp_vlan_group(p);
 986                 br = p->br;
 987         }
 988
 989         if (vid) {
 990                 v = br_vlan_find(vg, vid);
 991                 if (!v) {
 992                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 993                         return -EINVAL;
 994                 }
 995
 996                 err = __br_fdb_delete(br, p, addr, vid);
 997         } else {
 998                 err = -ENOENT;
 999                 err &= __br_fdb_delete(br, p, addr, 0);
1000                 if (!vg || !vg->num_vlans)
1001                         return err;
1002
1003                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1004                         if (!br_vlan_should_use(v))
1005                                 continue;
1006                         err &= __br_fdb_delete(br, p, addr, v->vid);
1007                 }
1008         }
1009
1010         return err;
1011 }
1012
1013 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1014 {
1015         struct net_bridge_fdb_entry *fdb, *tmp;
1016         int i;
1017         int err;
1018
1019         ASSERT_RTNL();
1020
1021         for (i = 0; i < BR_HASH_SIZE; i++) {
1022                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1023                         /* We only care for static entries */
1024                         if (!fdb->is_static)
1025                                 continue;
1026
1027                         err = dev_uc_add(p->dev, fdb->addr.addr);
1028                         if (err)
1029                                 goto rollback;
1030                 }
1031         }
1032         return 0;
1033
1034 rollback:
1035         for (i = 0; i < BR_HASH_SIZE; i++) {
1036                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1037                         /* If we reached the fdb that failed, we can stop */
1038                         if (tmp == fdb)
1039                                 break;
1040
1041                         /* We only care for static entries */
1042                         if (!tmp->is_static)
1043                                 continue;
1044
1045                         dev_uc_del(p->dev, tmp->addr.addr);
1046                 }
1047         }
1048         return err;
1049 }
1050
1051 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1052 {
1053         struct net_bridge_fdb_entry *fdb;
1054         int i;
1055
1056         ASSERT_RTNL();
1057
1058         for (i = 0; i < BR_HASH_SIZE; i++) {
1059                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1060                         /* We only care for static entries */
1061                         if (!fdb->is_static)
1062                                 continue;
1063
1064                         dev_uc_del(p->dev, fdb->addr.addr);
1065                 }
1066         }
1067 }
1068
1069 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1070                               const unsigned char *addr, u16 vid)
1071 {
1072         struct net_bridge_fdb_entry *fdb;
1073         struct hlist_head *head;
1074         bool modified = false;
1075         int err = 0;
1076
1077         trace_br_fdb_external_learn_add(br, p, addr, vid);
1078
1079         spin_lock_bh(&br->hash_lock);
1080
1081         head = &br->hash[br_mac_hash(addr, vid)];
1082         fdb = br_fdb_find(br, addr, vid);
1083         if (!fdb) {
1084                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1085                 if (!fdb) {
1086                         err = -ENOMEM;
1087                         goto err_unlock;
1088                 }
1089                 fdb->added_by_external_learn = 1;
1090                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1091         } else {
1092                 fdb->updated = jiffies;
1093
1094                 if (fdb->dst != p) {
1095                         fdb->dst = p;
1096                         modified = true;
1097                 }
1098
1099                 if (fdb->added_by_external_learn) {
1100                         /* Refresh entry */
1101                         fdb->used = jiffies;
1102                 } else if (!fdb->added_by_user) {
1103                         /* Take over SW learned entry */
1104                         fdb->added_by_external_learn = 1;
1105                         modified = true;
1106                 }
1107
1108                 if (modified)
1109                         fdb_notify(br, fdb, RTM_NEWNEIGH);
1110         }
1111
1112 err_unlock:
1113         spin_unlock_bh(&br->hash_lock);
1114
1115         return err;
1116 }
1117
1118 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1119                               const unsigned char *addr, u16 vid)
1120 {
1121         struct net_bridge_fdb_entry *fdb;
1122         int err = 0;
1123
1124         spin_lock_bh(&br->hash_lock);
1125
1126         fdb = br_fdb_find(br, addr, vid);
1127         if (fdb && fdb->added_by_external_learn)
1128                 fdb_delete(br, fdb);
1129         else
1130                 err = -ENOENT;
1131
1132         spin_unlock_bh(&br->hash_lock);
1133
1134         return err;
1135 }
1136
1137 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1138                           const unsigned char *addr, u16 vid)
1139 {
1140         struct net_bridge_fdb_entry *fdb;
1141
1142         spin_lock_bh(&br->hash_lock);
1143
1144         fdb = br_fdb_find(br, addr, vid);
1145         if (fdb)
1146                 fdb->offloaded = 1;
1147
1148         spin_unlock_bh(&br->hash_lock);
1149 }