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, unsigned long flags)
 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         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 570         if (likely(fdb)) {
 571                 /* attempt to update an entry for a local interface */
 572                 if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
 573                         if (net_ratelimit())
 574                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 575                                         source->dev->name, addr, vid);
 576                 } else {
 577                         unsigned long now = jiffies;
 578
 579                         /* fastpath: update of existing entry */
 580                         if (unlikely(source != fdb->dst &&
 581                                      !test_bit(BR_FDB_STICKY, &fdb->flags))) {
 582                                 fdb->dst = source;
 583                                 fdb_modified = true;
 584                                 /* Take over HW learned entry */
 585                                 if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
 586                                                       &fdb->flags)))
 587                                         clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
 588                                                   &fdb->flags);
 589                         }
 590                         if (now != fdb->updated)
 591                                 fdb->updated = now;
 592                         if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags)))
 593                                 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 594                         if (unlikely(fdb_modified)) {
 595                                 trace_br_fdb_update(br, source, addr, vid, flags);
 596                                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 597                         }
 598                 }
 599         } else {
 600                 spin_lock(&br->hash_lock);
 601                 fdb = fdb_create(br, source, addr, vid, flags);
 602                 if (fdb) {
 603                         trace_br_fdb_update(br, source, addr, vid, flags);
 604                         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 605                 }
 606                 /* else  we lose race and someone else inserts
 607                  * it first, don't bother updating
 608                  */
 609                 spin_unlock(&br->hash_lock);
 610         }
 611 }
 612
 613 static int fdb_to_nud(const struct net_bridge *br,
 614                       const struct net_bridge_fdb_entry *fdb)
 615 {
 616         if (test_bit(BR_FDB_LOCAL, &fdb->flags))
 617                 return NUD_PERMANENT;
 618         else if (test_bit(BR_FDB_STATIC, &fdb->flags))
 619                 return NUD_NOARP;
 620         else if (has_expired(br, fdb))
 621                 return NUD_STALE;
 622         else
 623                 return NUD_REACHABLE;
 624 }
 625
 626 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 627                          const struct net_bridge_fdb_entry *fdb,
 628                          u32 portid, u32 seq, int type, unsigned int flags)
 629 {
 630         unsigned long now = jiffies;
 631         struct nda_cacheinfo ci;
 632         struct nlmsghdr *nlh;
 633         struct ndmsg *ndm;
 634
 635         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 636         if (nlh == NULL)
 637                 return -EMSGSIZE;
 638
 639         ndm = nlmsg_data(nlh);
 640         ndm->ndm_family  = AF_BRIDGE;
 641         ndm->ndm_pad1    = 0;
 642         ndm->ndm_pad2    = 0;
 643         ndm->ndm_flags   = 0;
 644         ndm->ndm_type    = 0;
 645         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 646         ndm->ndm_state   = fdb_to_nud(br, fdb);
 647
 648         if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
 649                 ndm->ndm_flags |= NTF_OFFLOADED;
 650         if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
 651                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 652         if (test_bit(BR_FDB_STICKY, &fdb->flags))
 653                 ndm->ndm_flags |= NTF_STICKY;
 654
 655         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 656                 goto nla_put_failure;
 657         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 658                 goto nla_put_failure;
 659         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 660         ci.ndm_confirmed = 0;
 661         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 662         ci.ndm_refcnt    = 0;
 663         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 664                 goto nla_put_failure;
 665
 666         if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 667                                         &fdb->key.vlan_id))
 668                 goto nla_put_failure;
 669
 670         nlmsg_end(skb, nlh);
 671         return 0;
 672
 673 nla_put_failure:
 674         nlmsg_cancel(skb, nlh);
 675         return -EMSGSIZE;
 676 }
 677
 678 static inline size_t fdb_nlmsg_size(void)
 679 {
 680         return NLMSG_ALIGN(sizeof(struct ndmsg))
 681                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 682                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 683                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 684                 + nla_total_size(sizeof(struct nda_cacheinfo));
 685 }
 686
 687 static void fdb_notify(struct net_bridge *br,
 688                        const struct net_bridge_fdb_entry *fdb, int type,
 689                        bool swdev_notify)
 690 {
 691         struct net *net = dev_net(br->dev);
 692         struct sk_buff *skb;
 693         int err = -ENOBUFS;
 694
 695         if (swdev_notify)
 696                 br_switchdev_fdb_notify(fdb, type);
 697
 698         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 699         if (skb == NULL)
 700                 goto errout;
 701
 702         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 703         if (err < 0) {
 704                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 705                 WARN_ON(err == -EMSGSIZE);
 706                 kfree_skb(skb);
 707                 goto errout;
 708         }
 709         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 710         return;
 711 errout:
 712         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 713 }
 714
 715 /* Dump information about entries, in response to GETNEIGH */
 716 int br_fdb_dump(struct sk_buff *skb,
 717                 struct netlink_callback *cb,
 718                 struct net_device *dev,
 719                 struct net_device *filter_dev,
 720                 int *idx)
 721 {
 722         struct net_bridge *br = netdev_priv(dev);
 723         struct net_bridge_fdb_entry *f;
 724         int err = 0;
 725
 726         if (!(dev->priv_flags & IFF_EBRIDGE))
 727                 return err;
 728
 729         if (!filter_dev) {
 730                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 731                 if (err < 0)
 732                         return err;
 733         }
 734
 735         rcu_read_lock();
 736         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 737                 if (*idx < cb->args[2])
 738                         goto skip;
 739                 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 740                         if (filter_dev != dev)
 741                                 goto skip;
 742                         /* !f->dst is a special case for bridge
 743                          * It means the MAC belongs to the bridge
 744                          * Therefore need a little more filtering
 745                          * we only want to dump the !f->dst case
 746                          */
 747                         if (f->dst)
 748                                 goto skip;
 749                 }
 750                 if (!filter_dev && f->dst)
 751                         goto skip;
 752
 753                 err = fdb_fill_info(skb, br, f,
 754                                     NETLINK_CB(cb->skb).portid,
 755                                     cb->nlh->nlmsg_seq,
 756                                     RTM_NEWNEIGH,
 757                                     NLM_F_MULTI);
 758                 if (err < 0)
 759                         break;
 760 skip:
 761                 *idx += 1;
 762         }
 763         rcu_read_unlock();
 764
 765         return err;
 766 }
 767
 768 int br_fdb_get(struct sk_buff *skb,
 769                struct nlattr *tb[],
 770                struct net_device *dev,
 771                const unsigned char *addr,
 772                u16 vid, u32 portid, u32 seq,
 773                struct netlink_ext_ack *extack)
 774 {
 775         struct net_bridge *br = netdev_priv(dev);
 776         struct net_bridge_fdb_entry *f;
 777         int err = 0;
 778
 779         rcu_read_lock();
 780         f = br_fdb_find_rcu(br, addr, vid);
 781         if (!f) {
 782                 NL_SET_ERR_MSG(extack, "Fdb entry not found");
 783                 err = -ENOENT;
 784                 goto errout;
 785         }
 786
 787         err = fdb_fill_info(skb, br, f, portid, seq,
 788                             RTM_NEWNEIGH, 0);
 789 errout:
 790         rcu_read_unlock();
 791         return err;
 792 }
 793
 794 /* Update (create or replace) forwarding database entry */
 795 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 796                          const u8 *addr, u16 state, u16 flags, u16 vid,
 797                          u8 ndm_flags)
 798 {
 799         bool is_sticky = !!(ndm_flags & NTF_STICKY);
 800         struct net_bridge_fdb_entry *fdb;
 801         bool modified = false;
 802
 803         /* If the port cannot learn allow only local and static entries */
 804         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 805             !(source->state == BR_STATE_LEARNING ||
 806               source->state == BR_STATE_FORWARDING))
 807                 return -EPERM;
 808
 809         if (!source && !(state & NUD_PERMANENT)) {
 810                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 811                         br->dev->name);
 812                 return -EINVAL;
 813         }
 814
 815         if (is_sticky && (state & NUD_PERMANENT))
 816                 return -EINVAL;
 817
 818         fdb = br_fdb_find(br, addr, vid);
 819         if (fdb == NULL) {
 820                 if (!(flags & NLM_F_CREATE))
 821                         return -ENOENT;
 822
 823                 fdb = fdb_create(br, source, addr, vid, 0);
 824                 if (!fdb)
 825                         return -ENOMEM;
 826
 827                 modified = true;
 828         } else {
 829                 if (flags & NLM_F_EXCL)
 830                         return -EEXIST;
 831
 832                 if (fdb->dst != source) {
 833                         fdb->dst = source;
 834                         modified = true;
 835                 }
 836         }
 837
 838         if (fdb_to_nud(br, fdb) != state) {
 839                 if (state & NUD_PERMANENT) {
 840                         set_bit(BR_FDB_LOCAL, &fdb->flags);
 841                         if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 842                                 fdb_add_hw_addr(br, addr);
 843                 } else if (state & NUD_NOARP) {
 844                         clear_bit(BR_FDB_LOCAL, &fdb->flags);
 845                         if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
 846                                 fdb_add_hw_addr(br, addr);
 847                 } else {
 848                         clear_bit(BR_FDB_LOCAL, &fdb->flags);
 849                         if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
 850                                 fdb_del_hw_addr(br, addr);
 851                 }
 852
 853                 modified = true;
 854         }
 855
 856         if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
 857                 change_bit(BR_FDB_STICKY, &fdb->flags);
 858                 modified = true;
 859         }
 860
 861         set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
 862
 863         fdb->used = jiffies;
 864         if (modified) {
 865                 fdb->updated = jiffies;
 866                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 867         }
 868
 869         return 0;
 870 }
 871
 872 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 873                         struct net_bridge_port *p, const unsigned char *addr,
 874                         u16 nlh_flags, u16 vid)
 875 {
 876         int err = 0;
 877
 878         if (ndm->ndm_flags & NTF_USE) {
 879                 if (!p) {
 880                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 881                                 br->dev->name);
 882                         return -EINVAL;
 883                 }
 884                 if (!nbp_state_should_learn(p))
 885                         return 0;
 886
 887                 local_bh_disable();
 888                 rcu_read_lock();
 889                 br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
 890                 rcu_read_unlock();
 891                 local_bh_enable();
 892         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 893                 err = br_fdb_external_learn_add(br, p, addr, vid, true);
 894         } else {
 895                 spin_lock_bh(&br->hash_lock);
 896                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 897                                     nlh_flags, vid, ndm->ndm_flags);
 898                 spin_unlock_bh(&br->hash_lock);
 899         }
 900
 901         return err;
 902 }
 903
 904 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 905 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 906                struct net_device *dev,
 907                const unsigned char *addr, u16 vid, u16 nlh_flags,
 908                struct netlink_ext_ack *extack)
 909 {
 910         struct net_bridge_vlan_group *vg;
 911         struct net_bridge_port *p = NULL;
 912         struct net_bridge_vlan *v;
 913         struct net_bridge *br = NULL;
 914         int err = 0;
 915
 916         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 917
 918         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 919                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 920                 return -EINVAL;
 921         }
 922
 923         if (is_zero_ether_addr(addr)) {
 924                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 925                 return -EINVAL;
 926         }
 927
 928         if (dev->priv_flags & IFF_EBRIDGE) {
 929                 br = netdev_priv(dev);
 930                 vg = br_vlan_group(br);
 931         } else {
 932                 p = br_port_get_rtnl(dev);
 933                 if (!p) {
 934                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 935                                 dev->name);
 936                         return -EINVAL;
 937                 }
 938                 br = p->br;
 939                 vg = nbp_vlan_group(p);
 940         }
 941
 942         if (vid) {
 943                 v = br_vlan_find(vg, vid);
 944                 if (!v || !br_vlan_should_use(v)) {
 945                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 946                         return -EINVAL;
 947                 }
 948
 949                 /* VID was specified, so use it. */
 950                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 951         } else {
 952                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 953                 if (err || !vg || !vg->num_vlans)
 954                         goto out;
 955
 956                 /* We have vlans configured on this port and user didn't
 957                  * specify a VLAN.  To be nice, add/update entry for every
 958                  * vlan on this port.
 959                  */
 960                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 961                         if (!br_vlan_should_use(v))
 962                                 continue;
 963                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 964                         if (err)
 965                                 goto out;
 966                 }
 967         }
 968
 969 out:
 970         return err;
 971 }
 972
 973 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 974                                        const struct net_bridge_port *p,
 975                                        const u8 *addr, u16 vlan)
 976 {
 977         struct net_bridge_fdb_entry *fdb;
 978
 979         fdb = br_fdb_find(br, addr, vlan);
 980         if (!fdb || fdb->dst != p)
 981                 return -ENOENT;
 982
 983         fdb_delete(br, fdb, true);
 984
 985         return 0;
 986 }
 987
 988 static int __br_fdb_delete(struct net_bridge *br,
 989                            const struct net_bridge_port *p,
 990                            const unsigned char *addr, u16 vid)
 991 {
 992         int err;
 993
 994         spin_lock_bh(&br->hash_lock);
 995         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 996         spin_unlock_bh(&br->hash_lock);
 997
 998         return err;
 999 }
1000
1001 /* Remove neighbor entry with RTM_DELNEIGH */
1002 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1003                   struct net_device *dev,
1004                   const unsigned char *addr, u16 vid)
1005 {
1006         struct net_bridge_vlan_group *vg;
1007         struct net_bridge_port *p = NULL;
1008         struct net_bridge_vlan *v;
1009         struct net_bridge *br;
1010         int err;
1011
1012         if (dev->priv_flags & IFF_EBRIDGE) {
1013                 br = netdev_priv(dev);
1014                 vg = br_vlan_group(br);
1015         } else {
1016                 p = br_port_get_rtnl(dev);
1017                 if (!p) {
1018                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1019                                 dev->name);
1020                         return -EINVAL;
1021                 }
1022                 vg = nbp_vlan_group(p);
1023                 br = p->br;
1024         }
1025
1026         if (vid) {
1027                 v = br_vlan_find(vg, vid);
1028                 if (!v) {
1029                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1030                         return -EINVAL;
1031                 }
1032
1033                 err = __br_fdb_delete(br, p, addr, vid);
1034         } else {
1035                 err = -ENOENT;
1036                 err &= __br_fdb_delete(br, p, addr, 0);
1037                 if (!vg || !vg->num_vlans)
1038                         return err;
1039
1040                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1041                         if (!br_vlan_should_use(v))
1042                                 continue;
1043                         err &= __br_fdb_delete(br, p, addr, v->vid);
1044                 }
1045         }
1046
1047         return err;
1048 }
1049
1050 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1051 {
1052         struct net_bridge_fdb_entry *f, *tmp;
1053         int err = 0;
1054
1055         ASSERT_RTNL();
1056
1057         /* the key here is that static entries change only under rtnl */
1058         rcu_read_lock();
1059         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1060                 /* We only care for static entries */
1061                 if (!test_bit(BR_FDB_STATIC, &f->flags))
1062                         continue;
1063                 err = dev_uc_add(p->dev, f->key.addr.addr);
1064                 if (err)
1065                         goto rollback;
1066         }
1067 done:
1068         rcu_read_unlock();
1069
1070         return err;
1071
1072 rollback:
1073         hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1074                 /* We only care for static entries */
1075                 if (!test_bit(BR_FDB_STATIC, &tmp->flags))
1076                         continue;
1077                 if (tmp == f)
1078                         break;
1079                 dev_uc_del(p->dev, tmp->key.addr.addr);
1080         }
1081
1082         goto done;
1083 }
1084
1085 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1086 {
1087         struct net_bridge_fdb_entry *f;
1088
1089         ASSERT_RTNL();
1090
1091         rcu_read_lock();
1092         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1093                 /* We only care for static entries */
1094                 if (!test_bit(BR_FDB_STATIC, &f->flags))
1095                         continue;
1096
1097                 dev_uc_del(p->dev, f->key.addr.addr);
1098         }
1099         rcu_read_unlock();
1100 }
1101
1102 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1103                               const unsigned char *addr, u16 vid,
1104                               bool swdev_notify)
1105 {
1106         struct net_bridge_fdb_entry *fdb;
1107         bool modified = false;
1108         int err = 0;
1109
1110         trace_br_fdb_external_learn_add(br, p, addr, vid);
1111
1112         spin_lock_bh(&br->hash_lock);
1113
1114         fdb = br_fdb_find(br, addr, vid);
1115         if (!fdb) {
1116                 unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);
1117
1118                 if (swdev_notify)
1119                         flags |= BIT(BR_FDB_ADDED_BY_USER);
1120                 fdb = fdb_create(br, p, addr, vid, flags);
1121                 if (!fdb) {
1122                         err = -ENOMEM;
1123                         goto err_unlock;
1124                 }
1125                 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1126         } else {
1127                 fdb->updated = jiffies;
1128
1129                 if (fdb->dst != p) {
1130                         fdb->dst = p;
1131                         modified = true;
1132                 }
1133
1134                 if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
1135                         /* Refresh entry */
1136                         fdb->used = jiffies;
1137                 } else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) {
1138                         /* Take over SW learned entry */
1139                         set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
1140                         modified = true;
1141                 }
1142
1143                 if (swdev_notify)
1144                         set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
1145
1146                 if (modified)
1147                         fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1148         }
1149
1150 err_unlock:
1151         spin_unlock_bh(&br->hash_lock);
1152
1153         return err;
1154 }
1155
1156 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1157                               const unsigned char *addr, u16 vid,
1158                               bool swdev_notify)
1159 {
1160         struct net_bridge_fdb_entry *fdb;
1161         int err = 0;
1162
1163         spin_lock_bh(&br->hash_lock);
1164
1165         fdb = br_fdb_find(br, addr, vid);
1166         if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
1167                 fdb_delete(br, fdb, swdev_notify);
1168         else
1169                 err = -ENOENT;
1170
1171         spin_unlock_bh(&br->hash_lock);
1172
1173         return err;
1174 }
1175
1176 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1177                           const unsigned char *addr, u16 vid, bool offloaded)
1178 {
1179         struct net_bridge_fdb_entry *fdb;
1180
1181         spin_lock_bh(&br->hash_lock);
1182
1183         fdb = br_fdb_find(br, addr, vid);
1184         if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
1185                 change_bit(BR_FDB_OFFLOADED, &fdb->flags);
1186
1187         spin_unlock_bh(&br->hash_lock);
1188 }
1189
1190 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1191 {
1192         struct net_bridge_fdb_entry *f;
1193         struct net_bridge_port *p;
1194
1195         ASSERT_RTNL();
1196
1197         p = br_port_get_rtnl(dev);
1198         if (!p)
1199                 return;
1200
1201         spin_lock_bh(&p->br->hash_lock);
1202         hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1203                 if (f->dst == p && f->key.vlan_id == vid)
1204                         clear_bit(BR_FDB_OFFLOADED, &f->flags);
1205         }
1206         spin_unlock_bh(&p->br->hash_lock);
1207 }
1208 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);