net/bridge/br_fdb.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Forwarding database
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Lennert Buytenhek               <buytenh@gnu.org>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/rculist.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/times.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/jhash.h>
  18 #include <linux/random.h>
  19 #include <linux/slab.h>
  20 #include <linux/atomic.h>
  21 #include <asm/unaligned.h>
  22 #include <linux/if_vlan.h>
  23 #include <net/switchdev.h>
  24 #include <trace/events/bridge.h>
  25 #include "br_private.h"
  26
  27 static const struct rhashtable_params br_fdb_rht_params = {
  28         .head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
  29         .key_offset = offsetof(struct net_bridge_fdb_entry, key),
  30         .key_len = sizeof(struct net_bridge_fdb_key),
  31         .automatic_shrinking = true,
  32 };
  33
  34 static struct kmem_cache *br_fdb_cache __read_mostly;
  35 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  36                       const unsigned char *addr, u16 vid);
  37 static void fdb_notify(struct net_bridge *br,
  38                        const struct net_bridge_fdb_entry *, int, bool);
  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         return 0;
  50 }
  51
  52 void br_fdb_fini(void)
  53 {
  54         kmem_cache_destroy(br_fdb_cache);
  55 }
  56
  57 int br_fdb_hash_init(struct net_bridge *br)
  58 {
  59         return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
  60 }
  61
  62 void br_fdb_hash_fini(struct net_bridge *br)
  63 {
  64         rhashtable_destroy(&br->fdb_hash_tbl);
  65 }
  66
  67 /* if topology_changing then use forward_delay (default 15 sec)
  68  * otherwise keep longer (default 5 minutes)
  69  */
  70 static inline unsigned long hold_time(const struct net_bridge *br)
  71 {
  72         return br->topology_change ? br->forward_delay : br->ageing_time;
  73 }
  74
  75 static inline int has_expired(const struct net_bridge *br,
  76                                   const struct net_bridge_fdb_entry *fdb)
  77 {
  78         return !test_bit(BR_FDB_STATIC, &fdb->flags) &&
  79                !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) &&
  80                time_before_eq(fdb->updated + hold_time(br), jiffies);
  81 }
  82
  83 static void fdb_rcu_free(struct rcu_head *head)
  84 {
  85         struct net_bridge_fdb_entry *ent
  86                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  87         kmem_cache_free(br_fdb_cache, ent);
  88 }
  89
  90 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
  91                                                  const unsigned char *addr,
  92                                                  __u16 vid)
  93 {
  94         struct net_bridge_fdb_key key;
  95
  96         WARN_ON_ONCE(!rcu_read_lock_held());
  97
  98         key.vlan_id = vid;
  99         memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
 100
 101         return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
 102 }
 103
 104 /* requires bridge hash_lock */
 105 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 106                                                 const unsigned char *addr,
 107                                                 __u16 vid)
 108 {
 109         struct net_bridge_fdb_entry *fdb;
 110
 111         lockdep_assert_held_once(&br->hash_lock);
 112
 113         rcu_read_lock();
 114         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 115         rcu_read_unlock();
 116
 117         return fdb;
 118 }
 119
 120 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
 121                                     const unsigned char *addr,
 122                                     __u16 vid)
 123 {
 124         struct net_bridge_fdb_entry *f;
 125         struct net_device *dev = NULL;
 126         struct net_bridge *br;
 127
 128         ASSERT_RTNL();
 129
 130         if (!netif_is_bridge_master(br_dev))
 131                 return NULL;
 132
 133         br = netdev_priv(br_dev);
 134         rcu_read_lock();
 135         f = br_fdb_find_rcu(br, addr, vid);
 136         if (f && f->dst)
 137                 dev = f->dst->dev;
 138         rcu_read_unlock();
 139
 140         return dev;
 141 }
 142 EXPORT_SYMBOL_GPL(br_fdb_find_port);
 143
 144 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 145                                              const unsigned char *addr,
 146                                              __u16 vid)
 147 {
 148         return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 149 }
 150
 151 /* When a static FDB entry is added, the mac address from the entry is
 152  * added to the bridge private HW address list and all required ports
 153  * are then updated with the new information.
 154  * Called under RTNL.
 155  */
 156 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 157 {
 158         int err;
 159         struct net_bridge_port *p;
 160
 161         ASSERT_RTNL();
 162
 163         list_for_each_entry(p, &br->port_list, list) {
 164                 if (!br_promisc_port(p)) {
 165                         err = dev_uc_add(p->dev, addr);
 166                         if (err)
 167                                 goto undo;
 168                 }
 169         }
 170
 171         return;
 172 undo:
 173         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 174                 if (!br_promisc_port(p))
 175                         dev_uc_del(p->dev, addr);
 176         }
 177 }
 178
 179 /* When a static FDB entry is deleted, the HW address from that entry is
 180  * also removed from the bridge private HW address list and updates all
 181  * the ports with needed information.
 182  * Called under RTNL.
 183  */
 184 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 185 {
 186         struct net_bridge_port *p;
 187
 188         ASSERT_RTNL();
 189
 190         list_for_each_entry(p, &br->port_list, list) {
 191                 if (!br_promisc_port(p))
 192                         dev_uc_del(p->dev, addr);
 193         }
 194 }
 195
 196 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 197                        bool swdev_notify)
 198 {
 199         trace_fdb_delete(br, f);
 200
 201         if (test_bit(BR_FDB_STATIC, &f->flags))
 202                 fdb_del_hw_addr(br, f->key.addr.addr);
 203
 204         hlist_del_init_rcu(&f->fdb_node);
 205         rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
 206                                br_fdb_rht_params);
 207         fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
 208         call_rcu(&f->rcu, fdb_rcu_free);
 209 }
 210
 211 /* Delete a local entry if no other port had the same address. */
 212 static void fdb_delete_local(struct net_bridge *br,
 213                              const struct net_bridge_port *p,
 214                              struct net_bridge_fdb_entry *f)
 215 {
 216         const unsigned char *addr = f->key.addr.addr;
 217         struct net_bridge_vlan_group *vg;
 218         const struct net_bridge_vlan *v;
 219         struct net_bridge_port *op;
 220         u16 vid = f->key.vlan_id;
 221
 222         /* Maybe another port has same hw addr? */
 223         list_for_each_entry(op, &br->port_list, list) {
 224                 vg = nbp_vlan_group(op);
 225                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 226                     (!vid || br_vlan_find(vg, vid))) {
 227                         f->dst = op;
 228                         clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
 229                         return;
 230                 }
 231         }
 232
 233         vg = br_vlan_group(br);
 234         v = br_vlan_find(vg, vid);
 235         /* Maybe bridge device has same hw addr? */
 236         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 237             (!vid || (v && br_vlan_should_use(v)))) {
 238                 f->dst = NULL;
 239                 clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
 240                 return;
 241         }
 242
 243         fdb_delete(br, f, true);
 244 }
 245
 246 void br_fdb_find_delete_local(struct net_bridge *br,
 247                               const struct net_bridge_port *p,
 248                               const unsigned char *addr, u16 vid)
 249 {
 250         struct net_bridge_fdb_entry *f;
 251
 252         spin_lock_bh(&br->hash_lock);
 253         f = br_fdb_find(br, addr, vid);
 254         if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 255             !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p)
 256                 fdb_delete_local(br, p, f);
 257         spin_unlock_bh(&br->hash_lock);
 258 }
 259
 260 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 261 {
 262         struct net_bridge_vlan_group *vg;
 263         struct net_bridge_fdb_entry *f;
 264         struct net_bridge *br = p->br;
 265         struct net_bridge_vlan *v;
 266
 267         spin_lock_bh(&br->hash_lock);
 268         vg = nbp_vlan_group(p);
 269         hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
 270                 if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) &&
 271                     !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) {
 272                         /* delete old one */
 273                         fdb_delete_local(br, p, f);
 274
 275                         /* if this port has no vlan information
 276                          * configured, we can safely be done at
 277                          * this point.
 278                          */
 279                         if (!vg || !vg->num_vlans)
 280                                 goto insert;
 281                 }
 282         }
 283
 284 insert:
 285         /* insert new address,  may fail if invalid address or dup. */
 286         fdb_insert(br, p, newaddr, 0);
 287
 288         if (!vg || !vg->num_vlans)
 289                 goto done;
 290
 291         /* Now add entries for every VLAN configured on the port.
 292          * This function runs under RTNL so the bitmap will not change
 293          * from under us.
 294          */
 295         list_for_each_entry(v, &vg->vlan_list, vlist)
 296                 fdb_insert(br, p, newaddr, v->vid);
 297
 298 done:
 299         spin_unlock_bh(&br->hash_lock);
 300 }
 301
 302 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 303 {
 304         struct net_bridge_vlan_group *vg;
 305         struct net_bridge_fdb_entry *f;
 306         struct net_bridge_vlan *v;
 307
 308         spin_lock_bh(&br->hash_lock);
 309
 310         /* If old entry was unassociated with any port, then delete it. */
 311         f = br_fdb_find(br, br->dev->dev_addr, 0);
 312         if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 313             !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
 314                 fdb_delete_local(br, NULL, f);
 315
 316         fdb_insert(br, NULL, newaddr, 0);
 317         vg = br_vlan_group(br);
 318         if (!vg || !vg->num_vlans)
 319                 goto out;
 320         /* Now remove and add entries for every VLAN configured on the
 321          * bridge.  This function runs under RTNL so the bitmap will not
 322          * change from under us.
 323          */
 324         list_for_each_entry(v, &vg->vlan_list, vlist) {
 325                 if (!br_vlan_should_use(v))
 326                         continue;
 327                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 328                 if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
 329                     !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
 330                         fdb_delete_local(br, NULL, f);
 331                 fdb_insert(br, NULL, newaddr, v->vid);
 332         }
 333 out:
 334         spin_unlock_bh(&br->hash_lock);
 335 }
 336
 337 void br_fdb_cleanup(struct work_struct *work)
 338 {
 339         struct net_bridge *br = container_of(work, struct net_bridge,
 340                                              gc_work.work);
 341         struct net_bridge_fdb_entry *f = NULL;
 342         unsigned long delay = hold_time(br);
 343         unsigned long work_delay = delay;
 344         unsigned long now = jiffies;
 345
 346         /* this part is tricky, in order to avoid blocking learning and
 347          * consequently forwarding, we rely on rcu to delete objects with
 348          * delayed freeing allowing us to continue traversing
 349          */
 350         rcu_read_lock();
 351         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 352                 unsigned long this_timer;
 353
 354                 if (test_bit(BR_FDB_STATIC, &f->flags) ||
 355                     test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags))
 356                         continue;
 357                 this_timer = f->updated + delay;
 358                 if (time_after(this_timer, now)) {
 359                         work_delay = min(work_delay, this_timer - now);
 360                 } else {
 361                         spin_lock_bh(&br->hash_lock);
 362                         if (!hlist_unhashed(&f->fdb_node))
 363                                 fdb_delete(br, f, true);
 364                         spin_unlock_bh(&br->hash_lock);
 365                 }
 366         }
 367         rcu_read_unlock();
 368
 369         /* Cleanup minimum 10 milliseconds apart */
 370         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 371         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 372 }
 373
 374 /* Completely flush all dynamic entries in forwarding database.*/
 375 void br_fdb_flush(struct net_bridge *br)
 376 {
 377         struct net_bridge_fdb_entry *f;
 378         struct hlist_node *tmp;
 379
 380         spin_lock_bh(&br->hash_lock);
 381         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 382                 if (!test_bit(BR_FDB_STATIC, &f->flags))
 383                         fdb_delete(br, f, true);
 384         }
 385         spin_unlock_bh(&br->hash_lock);
 386 }
 387
 388 /* Flush all entries referring to a specific port.
 389  * if do_all is set also flush static entries
 390  * if vid is set delete all entries that match the vlan_id
 391  */
 392 void br_fdb_delete_by_port(struct net_bridge *br,
 393                            const struct net_bridge_port *p,
 394                            u16 vid,
 395                            int do_all)
 396 {
 397         struct net_bridge_fdb_entry *f;
 398         struct hlist_node *tmp;
 399
 400         spin_lock_bh(&br->hash_lock);
 401         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 402                 if (f->dst != p)
 403                         continue;
 404
 405                 if (!do_all)
 406                         if (test_bit(BR_FDB_STATIC, &f->flags) ||
 407                             (vid && f->key.vlan_id != vid))
 408                                 continue;
 409
 410                 if (test_bit(BR_FDB_LOCAL, &f->flags))
 411                         fdb_delete_local(br, p, f);
 412                 else
 413                         fdb_delete(br, f, true);
 414         }
 415         spin_unlock_bh(&br->hash_lock);
 416 }
 417
 418 #if IS_ENABLED(CONFIG_ATM_LANE)
 419 /* Interface used by ATM LANE hook to test
 420  * if an addr is on some other bridge port */
 421 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 422 {
 423         struct net_bridge_fdb_entry *fdb;
 424         struct net_bridge_port *port;
 425         int ret;
 426
 427         rcu_read_lock();
 428         port = br_port_get_rcu(dev);
 429         if (!port)
 430                 ret = 0;
 431         else {
 432                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 433                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 434                         fdb->dst->state == BR_STATE_FORWARDING;
 435         }
 436         rcu_read_unlock();
 437
 438         return ret;
 439 }
 440 #endif /* CONFIG_ATM_LANE */
 441
 442 /*
 443  * Fill buffer with forwarding table records in
 444  * the API format.
 445  */
 446 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 447                    unsigned long maxnum, unsigned long skip)
 448 {
 449         struct net_bridge_fdb_entry *f;
 450         struct __fdb_entry *fe = buf;
 451         int num = 0;
 452
 453         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 454
 455         rcu_read_lock();
 456         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 457                 if (num >= maxnum)
 458                         break;
 459
 460                 if (has_expired(br, f))
 461                         continue;
 462
 463                 /* ignore pseudo entry for local MAC address */
 464                 if (!f->dst)
 465                         continue;
 466
 467                 if (skip) {
 468                         --skip;
 469                         continue;
 470                 }
 471
 472                 /* convert from internal format to API */
 473                 memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
 474
 475                 /* due to ABI compat need to split into hi/lo */
 476                 fe->port_no = f->dst->port_no;
 477                 fe->port_hi = f->dst->port_no >> 8;
 478
 479                 fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
 480                 if (!test_bit(BR_FDB_STATIC, &f->flags))
 481                         fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 482                 ++fe;
 483                 ++num;
 484         }
 485         rcu_read_unlock();
 486
 487         return num;
 488 }
 489
 490 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
 491                                                struct net_bridge_port *source,
 492                                                const unsigned char *addr,
 493                                                __u16 vid,
 494                                                unsigned long flags)
 495 {
 496         struct net_bridge_fdb_entry *fdb;
 497
 498         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 499         if (fdb) {
 500                 memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
 501                 fdb->dst = source;
 502                 fdb->key.vlan_id = vid;
 503                 fdb->flags = flags;
 504                 fdb->updated = fdb->used = jiffies;
 505                 if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
 506                                                   &fdb->rhnode,
 507                                                   br_fdb_rht_params)) {
 508                         kmem_cache_free(br_fdb_cache, fdb);
 509                         fdb = NULL;
 510                 } else {
 511                         hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
 512                 }
 513         }
 514         return fdb;
 515 }
 516
 517 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 518                   const unsigned char *addr, u16 vid)
 519 {
 520         struct net_bridge_fdb_entry *fdb;
 521
 522         if (!is_valid_ether_addr(addr))
 523                 return -EINVAL;
 524
 525         fdb = br_fdb_find(br, addr, vid);
 526         if (fdb) {
 527                 /* it is okay to have multiple ports with same
 528                  * address, just use the first one.
 529                  */
 530                 if (test_bit(BR_FDB_LOCAL, &fdb->flags))
 531                         return 0;
 532                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 533                        source ? source->dev->name : br->dev->name, addr, vid);
 534                 fdb_delete(br, fdb, true);
 535         }
 536
 537         fdb = fdb_create(br, source, addr, vid,
 538                          BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
 539         if (!fdb)
 540                 return -ENOMEM;
 541
 542         fdb_add_hw_addr(br, addr);
 543         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 544         return 0;
 545 }
 546
 547 /* Add entry for local address of interface */
 548 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 549                   const unsigned char *addr, u16 vid)
 550 {
 551         int ret;
 552
 553         spin_lock_bh(&br->hash_lock);
 554         ret = fdb_insert(br, source, addr, vid);
 555         spin_unlock_bh(&br->hash_lock);
 556         return ret;
 557 }
 558
 559 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 560                    const unsigned char *addr, u16 vid, bool added_by_user)
 561 {
 562         struct net_bridge_fdb_entry *fdb;
 563         bool fdb_modified = false;
 564
 565         /* some users want to always flood. */
 566         if (hold_time(br) == 0)
 567                 return;
 568
 569         /* ignore packets unless we are using this port */
 570         if (!(source->state == BR_STATE_LEARNING ||
 571               source->state == BR_STATE_FORWARDING))
 572                 return;
 573
 574         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 575         if (likely(fdb)) {
 576                 /* attempt to update an entry for a local interface */
 577                 if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
 578                         if (net_ratelimit())
 579                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 580                                         source->dev->name, addr, vid);
 581                 } else {
 582                         unsigned long now = jiffies;
 583
 584                         /* fastpath: update of existing entry */
 585                         if (unlikely(source != fdb->dst &&
 586                                      !test_bit(BR_FDB_STICKY, &fdb->flags))) {
 587                                 fdb->dst = source;
 588                                 fdb_modified = true;
 589                                 /* Take over HW learned entry */
 590                                 test_and_clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
 591                                                    &fdb->flags);
 592                         }
 593                         if (now != fdb->updated)
 594                                 fdb->updated = now;
 595                         if (unlikely(added_by_user))
 596                                 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 597                         if (unlikely(fdb_modified)) {
 598                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 599                                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 600                         }
 601                 }
 602         } else {
 603                 spin_lock(&br->hash_lock);
 604                 fdb = fdb_create(br, source, addr, vid, 0);
 605                 if (fdb) {
 606                         if (unlikely(added_by_user))
 607                                 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 608                         trace_br_fdb_update(br, source, addr, vid,
 609                                             added_by_user);
 610                         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 611                 }
 612                 /* else  we lose race and someone else inserts
 613                  * it first, don't bother updating
 614                  */
 615                 spin_unlock(&br->hash_lock);
 616         }
 617 }
 618
 619 static int fdb_to_nud(const struct net_bridge *br,
 620                       const struct net_bridge_fdb_entry *fdb)
 621 {
 622         if (test_bit(BR_FDB_LOCAL, &fdb->flags))
 623                 return NUD_PERMANENT;
 624         else if (test_bit(BR_FDB_STATIC, &fdb->flags))
 625                 return NUD_NOARP;
 626         else if (has_expired(br, fdb))
 627                 return NUD_STALE;
 628         else
 629                 return NUD_REACHABLE;
 630 }
 631
 632 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 633                          const struct net_bridge_fdb_entry *fdb,
 634                          u32 portid, u32 seq, int type, unsigned int flags)
 635 {
 636         unsigned long now = jiffies;
 637         struct nda_cacheinfo ci;
 638         struct nlmsghdr *nlh;
 639         struct ndmsg *ndm;
 640
 641         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 642         if (nlh == NULL)
 643                 return -EMSGSIZE;
 644
 645         ndm = nlmsg_data(nlh);
 646         ndm->ndm_family  = AF_BRIDGE;
 647         ndm->ndm_pad1    = 0;
 648         ndm->ndm_pad2    = 0;
 649         ndm->ndm_flags   = 0;
 650         ndm->ndm_type    = 0;
 651         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 652         ndm->ndm_state   = fdb_to_nud(br, fdb);
 653
 654         if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
 655                 ndm->ndm_flags |= NTF_OFFLOADED;
 656         if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
 657                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 658         if (test_bit(BR_FDB_STICKY, &fdb->flags))
 659                 ndm->ndm_flags |= NTF_STICKY;
 660
 661         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 662                 goto nla_put_failure;
 663         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 664                 goto nla_put_failure;
 665         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 666         ci.ndm_confirmed = 0;
 667         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 668         ci.ndm_refcnt    = 0;
 669         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 670                 goto nla_put_failure;
 671
 672         if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 673                                         &fdb->key.vlan_id))
 674                 goto nla_put_failure;
 675
 676         nlmsg_end(skb, nlh);
 677         return 0;
 678
 679 nla_put_failure:
 680         nlmsg_cancel(skb, nlh);
 681         return -EMSGSIZE;
 682 }
 683
 684 static inline size_t fdb_nlmsg_size(void)
 685 {
 686         return NLMSG_ALIGN(sizeof(struct ndmsg))
 687                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 688                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 689                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 690                 + nla_total_size(sizeof(struct nda_cacheinfo));
 691 }
 692
 693 static void fdb_notify(struct net_bridge *br,
 694                        const struct net_bridge_fdb_entry *fdb, int type,
 695                        bool swdev_notify)
 696 {
 697         struct net *net = dev_net(br->dev);
 698         struct sk_buff *skb;
 699         int err = -ENOBUFS;
 700
 701         if (swdev_notify)
 702                 br_switchdev_fdb_notify(fdb, type);
 703
 704         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 705         if (skb == NULL)
 706                 goto errout;
 707
 708         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 709         if (err < 0) {
 710                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 711                 WARN_ON(err == -EMSGSIZE);
 712                 kfree_skb(skb);
 713                 goto errout;
 714         }
 715         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 716         return;
 717 errout:
 718         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 719 }
 720
 721 /* Dump information about entries, in response to GETNEIGH */
 722 int br_fdb_dump(struct sk_buff *skb,
 723                 struct netlink_callback *cb,
 724                 struct net_device *dev,
 725                 struct net_device *filter_dev,
 726                 int *idx)
 727 {
 728         struct net_bridge *br = netdev_priv(dev);
 729         struct net_bridge_fdb_entry *f;
 730         int err = 0;
 731
 732         if (!(dev->priv_flags & IFF_EBRIDGE))
 733                 return err;
 734
 735         if (!filter_dev) {
 736                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 737                 if (err < 0)
 738                         return err;
 739         }
 740
 741         rcu_read_lock();
 742         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 743                 if (*idx < cb->args[2])
 744                         goto skip;
 745                 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 746                         if (filter_dev != dev)
 747                                 goto skip;
 748                         /* !f->dst is a special case for bridge
 749                          * It means the MAC belongs to the bridge
 750                          * Therefore need a little more filtering
 751                          * we only want to dump the !f->dst case
 752                          */
 753                         if (f->dst)
 754                                 goto skip;
 755                 }
 756                 if (!filter_dev && f->dst)
 757                         goto skip;
 758
 759                 err = fdb_fill_info(skb, br, f,
 760                                     NETLINK_CB(cb->skb).portid,
 761                                     cb->nlh->nlmsg_seq,
 762                                     RTM_NEWNEIGH,
 763                                     NLM_F_MULTI);
 764                 if (err < 0)
 765                         break;
 766 skip:
 767                 *idx += 1;
 768         }
 769         rcu_read_unlock();
 770
 771         return err;
 772 }
 773
 774 int br_fdb_get(struct sk_buff *skb,
 775                struct nlattr *tb[],
 776                struct net_device *dev,
 777                const unsigned char *addr,
 778                u16 vid, u32 portid, u32 seq,
 779                struct netlink_ext_ack *extack)
 780 {
 781         struct net_bridge *br = netdev_priv(dev);
 782         struct net_bridge_fdb_entry *f;
 783         int err = 0;
 784
 785         rcu_read_lock();
 786         f = br_fdb_find_rcu(br, addr, vid);
 787         if (!f) {
 788                 NL_SET_ERR_MSG(extack, "Fdb entry not found");
 789                 err = -ENOENT;
 790                 goto errout;
 791         }
 792
 793         err = fdb_fill_info(skb, br, f, portid, seq,
 794                             RTM_NEWNEIGH, 0);
 795 errout:
 796         rcu_read_unlock();
 797         return err;
 798 }
 799
 800 /* Update (create or replace) forwarding database entry */
 801 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 802                          const u8 *addr, u16 state, u16 flags, u16 vid,
 803                          u8 ndm_flags)
 804 {
 805         bool is_sticky = !!(ndm_flags & NTF_STICKY);
 806         struct net_bridge_fdb_entry *fdb;
 807         bool modified = false;
 808
 809         /* If the port cannot learn allow only local and static entries */
 810         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 811             !(source->state == BR_STATE_LEARNING ||
 812               source->state == BR_STATE_FORWARDING))
 813                 return -EPERM;
 814
 815         if (!source && !(state & NUD_PERMANENT)) {
 816                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 817                         br->dev->name);
 818                 return -EINVAL;
 819         }
 820
 821         if (is_sticky && (state & NUD_PERMANENT))
 822                 return -EINVAL;
 823
 824         fdb = br_fdb_find(br, addr, vid);
 825         if (fdb == NULL) {
 826                 if (!(flags & NLM_F_CREATE))
 827                         return -ENOENT;
 828
 829                 fdb = fdb_create(br, source, addr, vid, 0);
 830                 if (!fdb)
 831                         return -ENOMEM;
 832
 833                 modified = true;
 834         } else {
 835                 if (flags & NLM_F_EXCL)
 836                         return -EEXIST;
 837
 838                 if (fdb->dst != source) {
 839                         fdb->dst = source;
 840                         modified = true;
 841                 }
 842         }
 843
 844         if (fdb_to_nud(br, fdb) != state) {
 845                 if (state & NUD_PERMANENT) {
 846                         set_bit(BR_FDB_LOCAL, &fdb->flags);
 847                         if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 848                                 fdb_add_hw_addr(br, addr);
 849                 } else if (state & NUD_NOARP) {
 850                         clear_bit(BR_FDB_LOCAL, &fdb->flags);
 851                         if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 852                                 fdb_add_hw_addr(br, addr);
 853                 } else {
 854                         clear_bit(BR_FDB_LOCAL, &fdb->flags);
 855                         if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
 856                                 fdb_del_hw_addr(br, addr);
 857                 }
 858
 859                 modified = true;
 860         }
 861
 862         if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
 863                 change_bit(BR_FDB_STICKY, &fdb->flags);
 864                 modified = true;
 865         }
 866
 867         set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 868
 869         fdb->used = jiffies;
 870         if (modified) {
 871                 fdb->updated = jiffies;
 872                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 873         }
 874
 875         return 0;
 876 }
 877
 878 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 879                         struct net_bridge_port *p, const unsigned char *addr,
 880                         u16 nlh_flags, u16 vid)
 881 {
 882         int err = 0;
 883
 884         if (ndm->ndm_flags & NTF_USE) {
 885                 if (!p) {
 886                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 887                                 br->dev->name);
 888                         return -EINVAL;
 889                 }
 890                 local_bh_disable();
 891                 rcu_read_lock();
 892                 br_fdb_update(br, p, addr, vid, true);
 893                 rcu_read_unlock();
 894                 local_bh_enable();
 895         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 896                 err = br_fdb_external_learn_add(br, p, addr, vid, true);
 897         } else {
 898                 spin_lock_bh(&br->hash_lock);
 899                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 900                                     nlh_flags, vid, ndm->ndm_flags);
 901                 spin_unlock_bh(&br->hash_lock);
 902         }
 903
 904         return err;
 905 }
 906
 907 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 908 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 909                struct net_device *dev,
 910                const unsigned char *addr, u16 vid, u16 nlh_flags,
 911                struct netlink_ext_ack *extack)
 912 {
 913         struct net_bridge_vlan_group *vg;
 914         struct net_bridge_port *p = NULL;
 915         struct net_bridge_vlan *v;
 916         struct net_bridge *br = NULL;
 917         int err = 0;
 918
 919         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 920
 921         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 922                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 923                 return -EINVAL;
 924         }
 925
 926         if (is_zero_ether_addr(addr)) {
 927                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 928                 return -EINVAL;
 929         }
 930
 931         if (dev->priv_flags & IFF_EBRIDGE) {
 932                 br = netdev_priv(dev);
 933                 vg = br_vlan_group(br);
 934         } else {
 935                 p = br_port_get_rtnl(dev);
 936                 if (!p) {
 937                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 938                                 dev->name);
 939                         return -EINVAL;
 940                 }
 941                 br = p->br;
 942                 vg = nbp_vlan_group(p);
 943         }
 944
 945         if (vid) {
 946                 v = br_vlan_find(vg, vid);
 947                 if (!v || !br_vlan_should_use(v)) {
 948                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 949                         return -EINVAL;
 950                 }
 951
 952                 /* VID was specified, so use it. */
 953                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 954         } else {
 955                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 956                 if (err || !vg || !vg->num_vlans)
 957                         goto out;
 958
 959                 /* We have vlans configured on this port and user didn't
 960                  * specify a VLAN.  To be nice, add/update entry for every
 961                  * vlan on this port.
 962                  */
 963                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 964                         if (!br_vlan_should_use(v))
 965                                 continue;
 966                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 967                         if (err)
 968                                 goto out;
 969                 }
 970         }
 971
 972 out:
 973         return err;
 974 }
 975
 976 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 977                                        const struct net_bridge_port *p,
 978                                        const u8 *addr, u16 vlan)
 979 {
 980         struct net_bridge_fdb_entry *fdb;
 981
 982         fdb = br_fdb_find(br, addr, vlan);
 983         if (!fdb || fdb->dst != p)
 984                 return -ENOENT;
 985
 986         fdb_delete(br, fdb, true);
 987
 988         return 0;
 989 }
 990
 991 static int __br_fdb_delete(struct net_bridge *br,
 992                            const struct net_bridge_port *p,
 993                            const unsigned char *addr, u16 vid)
 994 {
 995         int err;
 996
 997         spin_lock_bh(&br->hash_lock);
 998         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 999         spin_unlock_bh(&br->hash_lock);
1000
1001         return err;
1002 }
1003
1004 /* Remove neighbor entry with RTM_DELNEIGH */
1005 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1006                   struct net_device *dev,
1007                   const unsigned char *addr, u16 vid)
1008 {
1009         struct net_bridge_vlan_group *vg;
1010         struct net_bridge_port *p = NULL;
1011         struct net_bridge_vlan *v;
1012         struct net_bridge *br;
1013         int err;
1014
1015         if (dev->priv_flags & IFF_EBRIDGE) {
1016                 br = netdev_priv(dev);
1017                 vg = br_vlan_group(br);
1018         } else {
1019                 p = br_port_get_rtnl(dev);
1020                 if (!p) {
1021                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1022                                 dev->name);
1023                         return -EINVAL;
1024                 }
1025                 vg = nbp_vlan_group(p);
1026                 br = p->br;
1027         }
1028
1029         if (vid) {
1030                 v = br_vlan_find(vg, vid);
1031                 if (!v) {
1032                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1033                         return -EINVAL;
1034                 }
1035
1036                 err = __br_fdb_delete(br, p, addr, vid);
1037         } else {
1038                 err = -ENOENT;
1039                 err &= __br_fdb_delete(br, p, addr, 0);
1040                 if (!vg || !vg->num_vlans)
1041                         return err;
1042
1043                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1044                         if (!br_vlan_should_use(v))
1045                                 continue;
1046                         err &= __br_fdb_delete(br, p, addr, v->vid);
1047                 }
1048         }
1049
1050         return err;
1051 }
1052
1053 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1054 {
1055         struct net_bridge_fdb_entry *f, *tmp;
1056         int err = 0;
1057
1058         ASSERT_RTNL();
1059
1060         /* the key here is that static entries change only under rtnl */
1061         rcu_read_lock();
1062         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1063                 /* We only care for static entries */
1064                 if (!test_bit(BR_FDB_STATIC, &f->flags))
1065                         continue;
1066                 err = dev_uc_add(p->dev, f->key.addr.addr);
1067                 if (err)
1068                         goto rollback;
1069         }
1070 done:
1071         rcu_read_unlock();
1072
1073         return err;
1074
1075 rollback:
1076         hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1077                 /* We only care for static entries */
1078                 if (!test_bit(BR_FDB_STATIC, &tmp->flags))
1079                         continue;
1080                 if (tmp == f)
1081                         break;
1082                 dev_uc_del(p->dev, tmp->key.addr.addr);
1083         }
1084
1085         goto done;
1086 }
1087
1088 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1089 {
1090         struct net_bridge_fdb_entry *f;
1091
1092         ASSERT_RTNL();
1093
1094         rcu_read_lock();
1095         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1096                 /* We only care for static entries */
1097                 if (!test_bit(BR_FDB_STATIC, &f->flags))
1098                         continue;
1099
1100                 dev_uc_del(p->dev, f->key.addr.addr);
1101         }
1102         rcu_read_unlock();
1103 }
1104
1105 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1106                               const unsigned char *addr, u16 vid,
1107                               bool swdev_notify)
1108 {
1109         struct net_bridge_fdb_entry *fdb;
1110         bool modified = false;
1111         int err = 0;
1112
1113         trace_br_fdb_external_learn_add(br, p, addr, vid);
1114
1115         spin_lock_bh(&br->hash_lock);
1116
1117         fdb = br_fdb_find(br, addr, vid);
1118         if (!fdb) {
1119                 fdb = fdb_create(br, p, addr, vid, 0);
1120                 if (!fdb) {
1121                         err = -ENOMEM;
1122                         goto err_unlock;
1123                 }
1124                 if (swdev_notify)
1125                         set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1126                 set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
1127                 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1128         } else {
1129                 fdb->updated = jiffies;
1130
1131                 if (fdb->dst != p) {
1132                         fdb->dst = p;
1133                         modified = true;
1134                 }
1135
1136                 if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
1137                         /* Refresh entry */
1138                         fdb->used = jiffies;
1139                 } else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) {
1140                         /* Take over SW learned entry */
1141                         set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
1142                         modified = true;
1143                 }
1144
1145                 if (swdev_notify)
1146                         set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1147
1148                 if (modified)
1149                         fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1150         }
1151
1152 err_unlock:
1153         spin_unlock_bh(&br->hash_lock);
1154
1155         return err;
1156 }
1157
1158 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1159                               const unsigned char *addr, u16 vid,
1160                               bool swdev_notify)
1161 {
1162         struct net_bridge_fdb_entry *fdb;
1163         int err = 0;
1164
1165         spin_lock_bh(&br->hash_lock);
1166
1167         fdb = br_fdb_find(br, addr, vid);
1168         if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
1169                 fdb_delete(br, fdb, swdev_notify);
1170         else
1171                 err = -ENOENT;
1172
1173         spin_unlock_bh(&br->hash_lock);
1174
1175         return err;
1176 }
1177
1178 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1179                           const unsigned char *addr, u16 vid, bool offloaded)
1180 {
1181         struct net_bridge_fdb_entry *fdb;
1182
1183         spin_lock_bh(&br->hash_lock);
1184
1185         fdb = br_fdb_find(br, addr, vid);
1186         if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
1187                 change_bit(BR_FDB_OFFLOADED, &fdb->flags);
1188
1189         spin_unlock_bh(&br->hash_lock);
1190 }
1191
1192 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1193 {
1194         struct net_bridge_fdb_entry *f;
1195         struct net_bridge_port *p;
1196
1197         ASSERT_RTNL();
1198
1199         p = br_port_get_rtnl(dev);
1200         if (!p)
1201                 return;
1202
1203         spin_lock_bh(&p->br->hash_lock);
1204         hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1205                 if (f->dst == p && f->key.vlan_id == vid)
1206                         clear_bit(BR_FDB_OFFLOADED, &f->flags);
1207         }
1208         spin_unlock_bh(&p->br->hash_lock);
1209 }
1210 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);