net/bridge/br_fdb.c

   1 /*
   2  *      Forwarding database
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/rculist.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/times.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/jhash.h>
  22 #include <linux/random.h>
  23 #include <linux/slab.h>
  24 #include <linux/atomic.h>
  25 #include <asm/unaligned.h>
  26 #include <linux/if_vlan.h>
  27 #include <net/switchdev.h>
  28 #include "br_private.h"
  29
  30 static struct kmem_cache *br_fdb_cache __read_mostly;
  31 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  32                       const unsigned char *addr, u16 vid);
  33 static void fdb_notify(struct net_bridge *br,
  34                        const struct net_bridge_fdb_entry *, int);
  35
  36 static u32 fdb_salt __read_mostly;
  37
  38 int __init br_fdb_init(void)
  39 {
  40         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  41                                          sizeof(struct net_bridge_fdb_entry),
  42                                          0,
  43                                          SLAB_HWCACHE_ALIGN, NULL);
  44         if (!br_fdb_cache)
  45                 return -ENOMEM;
  46
  47         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  48         return 0;
  49 }
  50
  51 void br_fdb_fini(void)
  52 {
  53         kmem_cache_destroy(br_fdb_cache);
  54 }
  55
  56
  57 /* if topology_changing then use forward_delay (default 15 sec)
  58  * otherwise keep longer (default 5 minutes)
  59  */
  60 static inline unsigned long hold_time(const struct net_bridge *br)
  61 {
  62         return br->topology_change ? br->forward_delay : br->ageing_time;
  63 }
  64
  65 static inline int has_expired(const struct net_bridge *br,
  66                                   const struct net_bridge_fdb_entry *fdb)
  67 {
  68         return !fdb->is_static && !fdb->added_by_external_learn &&
  69                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  70 }
  71
  72 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  73 {
  74         /* use 1 byte of OUI and 3 bytes of NIC */
  75         u32 key = get_unaligned((u32 *)(mac + 2));
  76         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  77 }
  78
  79 static void fdb_rcu_free(struct rcu_head *head)
  80 {
  81         struct net_bridge_fdb_entry *ent
  82                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  83         kmem_cache_free(br_fdb_cache, ent);
  84 }
  85
  86 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
  87                                                  const unsigned char *addr,
  88                                                  __u16 vid)
  89 {
  90         struct net_bridge_fdb_entry *f;
  91
  92         WARN_ON_ONCE(!rcu_read_lock_held());
  93
  94         hlist_for_each_entry_rcu(f, head, hlist)
  95                 if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
  96                         break;
  97
  98         return f;
  99 }
 100
 101 /* requires bridge hash_lock */
 102 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 103                                                 const unsigned char *addr,
 104                                                 __u16 vid)
 105 {
 106         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 107         struct net_bridge_fdb_entry *fdb;
 108
 109         lockdep_assert_held_once(&br->hash_lock);
 110
 111         rcu_read_lock();
 112         fdb = fdb_find_rcu(head, addr, vid);
 113         rcu_read_unlock();
 114
 115         return fdb;
 116 }
 117
 118 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 119                                              const unsigned char *addr,
 120                                              __u16 vid)
 121 {
 122         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 123
 124         return fdb_find_rcu(head, addr, vid);
 125 }
 126
 127 /* When a static FDB entry is added, the mac address from the entry is
 128  * added to the bridge private HW address list and all required ports
 129  * are then updated with the new information.
 130  * Called under RTNL.
 131  */
 132 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 133 {
 134         int err;
 135         struct net_bridge_port *p;
 136
 137         ASSERT_RTNL();
 138
 139         list_for_each_entry(p, &br->port_list, list) {
 140                 if (!br_promisc_port(p)) {
 141                         err = dev_uc_add(p->dev, addr);
 142                         if (err)
 143                                 goto undo;
 144                 }
 145         }
 146
 147         return;
 148 undo:
 149         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 150                 if (!br_promisc_port(p))
 151                         dev_uc_del(p->dev, addr);
 152         }
 153 }
 154
 155 /* When a static FDB entry is deleted, the HW address from that entry is
 156  * also removed from the bridge private HW address list and updates all
 157  * the ports with needed information.
 158  * Called under RTNL.
 159  */
 160 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 161 {
 162         struct net_bridge_port *p;
 163
 164         ASSERT_RTNL();
 165
 166         list_for_each_entry(p, &br->port_list, list) {
 167                 if (!br_promisc_port(p))
 168                         dev_uc_del(p->dev, addr);
 169         }
 170 }
 171
 172 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 173 {
 174         struct switchdev_obj_port_fdb fdb = {
 175                 .obj = {
 176                         .orig_dev = f->dst->dev,
 177                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 178                         .flags = SWITCHDEV_F_DEFER,
 179                 },
 180                 .vid = f->vlan_id,
 181         };
 182
 183         ether_addr_copy(fdb.addr, f->addr.addr);
 184         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 185 }
 186
 187 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 188 {
 189         if (f->is_static)
 190                 fdb_del_hw_addr(br, f->addr.addr);
 191
 192         if (f->added_by_external_learn)
 193                 fdb_del_external_learn(f);
 194
 195         hlist_del_init_rcu(&f->hlist);
 196         fdb_notify(br, f, RTM_DELNEIGH);
 197         call_rcu(&f->rcu, fdb_rcu_free);
 198 }
 199
 200 /* Delete a local entry if no other port had the same address. */
 201 static void fdb_delete_local(struct net_bridge *br,
 202                              const struct net_bridge_port *p,
 203                              struct net_bridge_fdb_entry *f)
 204 {
 205         const unsigned char *addr = f->addr.addr;
 206         struct net_bridge_vlan_group *vg;
 207         const struct net_bridge_vlan *v;
 208         struct net_bridge_port *op;
 209         u16 vid = f->vlan_id;
 210
 211         /* Maybe another port has same hw addr? */
 212         list_for_each_entry(op, &br->port_list, list) {
 213                 vg = nbp_vlan_group(op);
 214                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 215                     (!vid || br_vlan_find(vg, vid))) {
 216                         f->dst = op;
 217                         f->added_by_user = 0;
 218                         return;
 219                 }
 220         }
 221
 222         vg = br_vlan_group(br);
 223         v = br_vlan_find(vg, vid);
 224         /* Maybe bridge device has same hw addr? */
 225         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 226             (!vid || (v && br_vlan_should_use(v)))) {
 227                 f->dst = NULL;
 228                 f->added_by_user = 0;
 229                 return;
 230         }
 231
 232         fdb_delete(br, f);
 233 }
 234
 235 void br_fdb_find_delete_local(struct net_bridge *br,
 236                               const struct net_bridge_port *p,
 237                               const unsigned char *addr, u16 vid)
 238 {
 239         struct net_bridge_fdb_entry *f;
 240
 241         spin_lock_bh(&br->hash_lock);
 242         f = br_fdb_find(br, addr, vid);
 243         if (f && f->is_local && !f->added_by_user && f->dst == p)
 244                 fdb_delete_local(br, p, f);
 245         spin_unlock_bh(&br->hash_lock);
 246 }
 247
 248 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 249 {
 250         struct net_bridge_vlan_group *vg;
 251         struct net_bridge *br = p->br;
 252         struct net_bridge_vlan *v;
 253         int i;
 254
 255         spin_lock_bh(&br->hash_lock);
 256
 257         vg = nbp_vlan_group(p);
 258         /* Search all chains since old address/hash is unknown */
 259         for (i = 0; i < BR_HASH_SIZE; i++) {
 260                 struct hlist_node *h;
 261                 hlist_for_each(h, &br->hash[i]) {
 262                         struct net_bridge_fdb_entry *f;
 263
 264                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 265                         if (f->dst == p && f->is_local && !f->added_by_user) {
 266                                 /* delete old one */
 267                                 fdb_delete_local(br, p, f);
 268
 269                                 /* if this port has no vlan information
 270                                  * configured, we can safely be done at
 271                                  * this point.
 272                                  */
 273                                 if (!vg || !vg->num_vlans)
 274                                         goto insert;
 275                         }
 276                 }
 277         }
 278
 279 insert:
 280         /* insert new address,  may fail if invalid address or dup. */
 281         fdb_insert(br, p, newaddr, 0);
 282
 283         if (!vg || !vg->num_vlans)
 284                 goto done;
 285
 286         /* Now add entries for every VLAN configured on the port.
 287          * This function runs under RTNL so the bitmap will not change
 288          * from under us.
 289          */
 290         list_for_each_entry(v, &vg->vlan_list, vlist)
 291                 fdb_insert(br, p, newaddr, v->vid);
 292
 293 done:
 294         spin_unlock_bh(&br->hash_lock);
 295 }
 296
 297 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 298 {
 299         struct net_bridge_vlan_group *vg;
 300         struct net_bridge_fdb_entry *f;
 301         struct net_bridge_vlan *v;
 302
 303         spin_lock_bh(&br->hash_lock);
 304
 305         /* If old entry was unassociated with any port, then delete it. */
 306         f = br_fdb_find(br, br->dev->dev_addr, 0);
 307         if (f && f->is_local && !f->dst && !f->added_by_user)
 308                 fdb_delete_local(br, NULL, f);
 309
 310         fdb_insert(br, NULL, newaddr, 0);
 311         vg = br_vlan_group(br);
 312         if (!vg || !vg->num_vlans)
 313                 goto out;
 314         /* Now remove and add entries for every VLAN configured on the
 315          * bridge.  This function runs under RTNL so the bitmap will not
 316          * change from under us.
 317          */
 318         list_for_each_entry(v, &vg->vlan_list, vlist) {
 319                 if (!br_vlan_should_use(v))
 320                         continue;
 321                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 322                 if (f && f->is_local && !f->dst && !f->added_by_user)
 323                         fdb_delete_local(br, NULL, f);
 324                 fdb_insert(br, NULL, newaddr, v->vid);
 325         }
 326 out:
 327         spin_unlock_bh(&br->hash_lock);
 328 }
 329
 330 void br_fdb_cleanup(struct work_struct *work)
 331 {
 332         struct net_bridge *br = container_of(work, struct net_bridge,
 333                                              gc_work.work);
 334         unsigned long delay = hold_time(br);
 335         unsigned long work_delay = delay;
 336         unsigned long now = jiffies;
 337         int i;
 338
 339         for (i = 0; i < BR_HASH_SIZE; i++) {
 340                 struct net_bridge_fdb_entry *f;
 341                 struct hlist_node *n;
 342
 343                 if (!br->hash[i].first)
 344                         continue;
 345
 346                 spin_lock_bh(&br->hash_lock);
 347                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 348                         unsigned long this_timer;
 349
 350                         if (f->is_static)
 351                                 continue;
 352                         if (f->added_by_external_learn)
 353                                 continue;
 354                         this_timer = f->updated + delay;
 355                         if (time_after(this_timer, now))
 356                                 work_delay = min(work_delay, this_timer - now);
 357                         else
 358                                 fdb_delete(br, f);
 359                 }
 360                 spin_unlock_bh(&br->hash_lock);
 361                 cond_resched();
 362         }
 363
 364         /* Cleanup minimum 10 milliseconds apart */
 365         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 366         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 367 }
 368
 369 /* Completely flush all dynamic entries in forwarding database.*/
 370 void br_fdb_flush(struct net_bridge *br)
 371 {
 372         int i;
 373
 374         spin_lock_bh(&br->hash_lock);
 375         for (i = 0; i < BR_HASH_SIZE; i++) {
 376                 struct net_bridge_fdb_entry *f;
 377                 struct hlist_node *n;
 378                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 379                         if (!f->is_static)
 380                                 fdb_delete(br, f);
 381                 }
 382         }
 383         spin_unlock_bh(&br->hash_lock);
 384 }
 385
 386 /* Flush all entries referring to a specific port.
 387  * if do_all is set also flush static entries
 388  * if vid is set delete all entries that match the vlan_id
 389  */
 390 void br_fdb_delete_by_port(struct net_bridge *br,
 391                            const struct net_bridge_port *p,
 392                            u16 vid,
 393                            int do_all)
 394 {
 395         int i;
 396
 397         spin_lock_bh(&br->hash_lock);
 398         for (i = 0; i < BR_HASH_SIZE; i++) {
 399                 struct hlist_node *h, *g;
 400
 401                 hlist_for_each_safe(h, g, &br->hash[i]) {
 402                         struct net_bridge_fdb_entry *f
 403                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 404                         if (f->dst != p)
 405                                 continue;
 406
 407                         if (!do_all)
 408                                 if (f->is_static || (vid && f->vlan_id != vid))
 409                                         continue;
 410
 411                         if (f->is_local)
 412                                 fdb_delete_local(br, p, f);
 413                         else
 414                                 fdb_delete(br, f);
 415                 }
 416         }
 417         spin_unlock_bh(&br->hash_lock);
 418 }
 419
 420 #if IS_ENABLED(CONFIG_ATM_LANE)
 421 /* Interface used by ATM LANE hook to test
 422  * if an addr is on some other bridge port */
 423 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 424 {
 425         struct net_bridge_fdb_entry *fdb;
 426         struct net_bridge_port *port;
 427         int ret;
 428
 429         rcu_read_lock();
 430         port = br_port_get_rcu(dev);
 431         if (!port)
 432                 ret = 0;
 433         else {
 434                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 435                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 436                         fdb->dst->state == BR_STATE_FORWARDING;
 437         }
 438         rcu_read_unlock();
 439
 440         return ret;
 441 }
 442 #endif /* CONFIG_ATM_LANE */
 443
 444 /*
 445  * Fill buffer with forwarding table records in
 446  * the API format.
 447  */
 448 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 449                    unsigned long maxnum, unsigned long skip)
 450 {
 451         struct __fdb_entry *fe = buf;
 452         int i, num = 0;
 453         struct net_bridge_fdb_entry *f;
 454
 455         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 456
 457         rcu_read_lock();
 458         for (i = 0; i < BR_HASH_SIZE; i++) {
 459                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 460                         if (num >= maxnum)
 461                                 goto out;
 462
 463                         if (has_expired(br, f))
 464                                 continue;
 465
 466                         /* ignore pseudo entry for local MAC address */
 467                         if (!f->dst)
 468                                 continue;
 469
 470                         if (skip) {
 471                                 --skip;
 472                                 continue;
 473                         }
 474
 475                         /* convert from internal format to API */
 476                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 477
 478                         /* due to ABI compat need to split into hi/lo */
 479                         fe->port_no = f->dst->port_no;
 480                         fe->port_hi = f->dst->port_no >> 8;
 481
 482                         fe->is_local = f->is_local;
 483                         if (!f->is_static)
 484                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 485                         ++fe;
 486                         ++num;
 487                 }
 488         }
 489
 490  out:
 491         rcu_read_unlock();
 492
 493         return num;
 494 }
 495
 496 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 497                                                struct net_bridge_port *source,
 498                                                const unsigned char *addr,
 499                                                __u16 vid,
 500                                                unsigned char is_local,
 501                                                unsigned char is_static)
 502 {
 503         struct net_bridge_fdb_entry *fdb;
 504
 505         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 506         if (fdb) {
 507                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 508                 fdb->dst = source;
 509                 fdb->vlan_id = vid;
 510                 fdb->is_local = is_local;
 511                 fdb->is_static = is_static;
 512                 fdb->added_by_user = 0;
 513                 fdb->added_by_external_learn = 0;
 514                 fdb->offloaded = 0;
 515                 fdb->updated = fdb->used = jiffies;
 516                 hlist_add_head_rcu(&fdb->hlist, head);
 517         }
 518         return fdb;
 519 }
 520
 521 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 522                   const unsigned char *addr, u16 vid)
 523 {
 524         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 525         struct net_bridge_fdb_entry *fdb;
 526
 527         if (!is_valid_ether_addr(addr))
 528                 return -EINVAL;
 529
 530         fdb = br_fdb_find(br, addr, vid);
 531         if (fdb) {
 532                 /* it is okay to have multiple ports with same
 533                  * address, just use the first one.
 534                  */
 535                 if (fdb->is_local)
 536                         return 0;
 537                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 538                        source ? source->dev->name : br->dev->name, addr, vid);
 539                 fdb_delete(br, fdb);
 540         }
 541
 542         fdb = fdb_create(head, source, addr, vid, 1, 1);
 543         if (!fdb)
 544                 return -ENOMEM;
 545
 546         fdb_add_hw_addr(br, addr);
 547         fdb_notify(br, fdb, RTM_NEWNEIGH);
 548         return 0;
 549 }
 550
 551 /* Add entry for local address of interface */
 552 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 553                   const unsigned char *addr, u16 vid)
 554 {
 555         int ret;
 556
 557         spin_lock_bh(&br->hash_lock);
 558         ret = fdb_insert(br, source, addr, vid);
 559         spin_unlock_bh(&br->hash_lock);
 560         return ret;
 561 }
 562
 563 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 564                    const unsigned char *addr, u16 vid, bool added_by_user)
 565 {
 566         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 567         struct net_bridge_fdb_entry *fdb;
 568         bool fdb_modified = false;
 569
 570         /* some users want to always flood. */
 571         if (hold_time(br) == 0)
 572                 return;
 573
 574         /* ignore packets unless we are using this port */
 575         if (!(source->state == BR_STATE_LEARNING ||
 576               source->state == BR_STATE_FORWARDING))
 577                 return;
 578
 579         fdb = fdb_find_rcu(head, addr, vid);
 580         if (likely(fdb)) {
 581                 /* attempt to update an entry for a local interface */
 582                 if (unlikely(fdb->is_local)) {
 583                         if (net_ratelimit())
 584                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 585                                         source->dev->name, addr, vid);
 586                 } else {
 587                         unsigned long now = jiffies;
 588
 589                         /* fastpath: update of existing entry */
 590                         if (unlikely(source != fdb->dst)) {
 591                                 fdb->dst = source;
 592                                 fdb_modified = true;
 593                                 /* Take over HW learned entry */
 594                                 if (unlikely(fdb->added_by_external_learn))
 595                                         fdb->added_by_external_learn = 0;
 596                         }
 597                         if (now != fdb->updated)
 598                                 fdb->updated = now;
 599                         if (unlikely(added_by_user))
 600                                 fdb->added_by_user = 1;
 601                         if (unlikely(fdb_modified))
 602                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 603                 }
 604         } else {
 605                 spin_lock(&br->hash_lock);
 606                 if (likely(!fdb_find_rcu(head, addr, vid))) {
 607                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 608                         if (fdb) {
 609                                 if (unlikely(added_by_user))
 610                                         fdb->added_by_user = 1;
 611                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 612                         }
 613                 }
 614                 /* else  we lose race and someone else inserts
 615                  * it first, don't bother updating
 616                  */
 617                 spin_unlock(&br->hash_lock);
 618         }
 619 }
 620
 621 static int fdb_to_nud(const struct net_bridge *br,
 622                       const struct net_bridge_fdb_entry *fdb)
 623 {
 624         if (fdb->is_local)
 625                 return NUD_PERMANENT;
 626         else if (fdb->is_static)
 627                 return NUD_NOARP;
 628         else if (has_expired(br, fdb))
 629                 return NUD_STALE;
 630         else
 631                 return NUD_REACHABLE;
 632 }
 633
 634 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 635                          const struct net_bridge_fdb_entry *fdb,
 636                          u32 portid, u32 seq, int type, unsigned int flags)
 637 {
 638         unsigned long now = jiffies;
 639         struct nda_cacheinfo ci;
 640         struct nlmsghdr *nlh;
 641         struct ndmsg *ndm;
 642
 643         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 644         if (nlh == NULL)
 645                 return -EMSGSIZE;
 646
 647         ndm = nlmsg_data(nlh);
 648         ndm->ndm_family  = AF_BRIDGE;
 649         ndm->ndm_pad1    = 0;
 650         ndm->ndm_pad2    = 0;
 651         ndm->ndm_flags   = 0;
 652         ndm->ndm_type    = 0;
 653         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 654         ndm->ndm_state   = fdb_to_nud(br, fdb);
 655
 656         if (fdb->offloaded)
 657                 ndm->ndm_flags |= NTF_OFFLOADED;
 658         if (fdb->added_by_external_learn)
 659                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 660
 661         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->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->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 673                 goto nla_put_failure;
 674
 675         nlmsg_end(skb, nlh);
 676         return 0;
 677
 678 nla_put_failure:
 679         nlmsg_cancel(skb, nlh);
 680         return -EMSGSIZE;
 681 }
 682
 683 static inline size_t fdb_nlmsg_size(void)
 684 {
 685         return NLMSG_ALIGN(sizeof(struct ndmsg))
 686                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 687                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 688                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 689                 + nla_total_size(sizeof(struct nda_cacheinfo));
 690 }
 691
 692 static void fdb_notify(struct net_bridge *br,
 693                        const struct net_bridge_fdb_entry *fdb, int type)
 694 {
 695         struct net *net = dev_net(br->dev);
 696         struct sk_buff *skb;
 697         int err = -ENOBUFS;
 698
 699         br_switchdev_fdb_notify(fdb, type);
 700
 701         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 702         if (skb == NULL)
 703                 goto errout;
 704
 705         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 706         if (err < 0) {
 707                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 708                 WARN_ON(err == -EMSGSIZE);
 709                 kfree_skb(skb);
 710                 goto errout;
 711         }
 712         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 713         return;
 714 errout:
 715         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 716 }
 717
 718 /* Dump information about entries, in response to GETNEIGH */
 719 int br_fdb_dump(struct sk_buff *skb,
 720                 struct netlink_callback *cb,
 721                 struct net_device *dev,
 722                 struct net_device *filter_dev,
 723                 int *idx)
 724 {
 725         struct net_bridge *br = netdev_priv(dev);
 726         int err = 0;
 727         int i;
 728
 729         if (!(dev->priv_flags & IFF_EBRIDGE))
 730                 goto out;
 731
 732         if (!filter_dev) {
 733                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 734                 if (err < 0)
 735                         goto out;
 736         }
 737
 738         for (i = 0; i < BR_HASH_SIZE; i++) {
 739                 struct net_bridge_fdb_entry *f;
 740
 741                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 742
 743                         if (*idx < cb->args[2])
 744                                 goto skip;
 745
 746                         if (filter_dev &&
 747                             (!f->dst || f->dst->dev != filter_dev)) {
 748                                 if (filter_dev != dev)
 749                                         goto skip;
 750                                 /* !f->dst is a special case for bridge
 751                                  * It means the MAC belongs to the bridge
 752                                  * Therefore need a little more filtering
 753                                  * we only want to dump the !f->dst case
 754                                  */
 755                                 if (f->dst)
 756                                         goto skip;
 757                         }
 758                         if (!filter_dev && f->dst)
 759                                 goto skip;
 760
 761                         err = fdb_fill_info(skb, br, f,
 762                                             NETLINK_CB(cb->skb).portid,
 763                                             cb->nlh->nlmsg_seq,
 764                                             RTM_NEWNEIGH,
 765                                             NLM_F_MULTI);
 766                         if (err < 0)
 767                                 goto out;
 768 skip:
 769                         *idx += 1;
 770                 }
 771         }
 772
 773 out:
 774         return err;
 775 }
 776
 777 /* Update (create or replace) forwarding database entry */
 778 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 779                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 780 {
 781         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 782         struct net_bridge_fdb_entry *fdb;
 783         bool modified = false;
 784
 785         /* If the port cannot learn allow only local and static entries */
 786         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 787             !(source->state == BR_STATE_LEARNING ||
 788               source->state == BR_STATE_FORWARDING))
 789                 return -EPERM;
 790
 791         if (!source && !(state & NUD_PERMANENT)) {
 792                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 793                         br->dev->name);
 794                 return -EINVAL;
 795         }
 796
 797         fdb = br_fdb_find(br, addr, vid);
 798         if (fdb == NULL) {
 799                 if (!(flags & NLM_F_CREATE))
 800                         return -ENOENT;
 801
 802                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 803                 if (!fdb)
 804                         return -ENOMEM;
 805
 806                 modified = true;
 807         } else {
 808                 if (flags & NLM_F_EXCL)
 809                         return -EEXIST;
 810
 811                 if (fdb->dst != source) {
 812                         fdb->dst = source;
 813                         modified = true;
 814                 }
 815         }
 816
 817         if (fdb_to_nud(br, fdb) != state) {
 818                 if (state & NUD_PERMANENT) {
 819                         fdb->is_local = 1;
 820                         if (!fdb->is_static) {
 821                                 fdb->is_static = 1;
 822                                 fdb_add_hw_addr(br, addr);
 823                         }
 824                 } else if (state & NUD_NOARP) {
 825                         fdb->is_local = 0;
 826                         if (!fdb->is_static) {
 827                                 fdb->is_static = 1;
 828                                 fdb_add_hw_addr(br, addr);
 829                         }
 830                 } else {
 831                         fdb->is_local = 0;
 832                         if (fdb->is_static) {
 833                                 fdb->is_static = 0;
 834                                 fdb_del_hw_addr(br, addr);
 835                         }
 836                 }
 837
 838                 modified = true;
 839         }
 840         fdb->added_by_user = 1;
 841
 842         fdb->used = jiffies;
 843         if (modified) {
 844                 fdb->updated = jiffies;
 845                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 846         }
 847
 848         return 0;
 849 }
 850
 851 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 852                         struct net_bridge_port *p, const unsigned char *addr,
 853                         u16 nlh_flags, u16 vid)
 854 {
 855         int err = 0;
 856
 857         if (ndm->ndm_flags & NTF_USE) {
 858                 if (!p) {
 859                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 860                                 br->dev->name);
 861                         return -EINVAL;
 862                 }
 863                 local_bh_disable();
 864                 rcu_read_lock();
 865                 br_fdb_update(br, p, addr, vid, true);
 866                 rcu_read_unlock();
 867                 local_bh_enable();
 868         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 869                 err = br_fdb_external_learn_add(br, p, addr, vid);
 870         } else {
 871                 spin_lock_bh(&br->hash_lock);
 872                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 873                                     nlh_flags, vid);
 874                 spin_unlock_bh(&br->hash_lock);
 875         }
 876
 877         return err;
 878 }
 879
 880 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 881 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 882                struct net_device *dev,
 883                const unsigned char *addr, u16 vid, u16 nlh_flags)
 884 {
 885         struct net_bridge_vlan_group *vg;
 886         struct net_bridge_port *p = NULL;
 887         struct net_bridge_vlan *v;
 888         struct net_bridge *br = NULL;
 889         int err = 0;
 890
 891         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 892                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 893                 return -EINVAL;
 894         }
 895
 896         if (is_zero_ether_addr(addr)) {
 897                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 898                 return -EINVAL;
 899         }
 900
 901         if (dev->priv_flags & IFF_EBRIDGE) {
 902                 br = netdev_priv(dev);
 903                 vg = br_vlan_group(br);
 904         } else {
 905                 p = br_port_get_rtnl(dev);
 906                 if (!p) {
 907                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 908                                 dev->name);
 909                         return -EINVAL;
 910                 }
 911                 br = p->br;
 912                 vg = nbp_vlan_group(p);
 913         }
 914
 915         if (vid) {
 916                 v = br_vlan_find(vg, vid);
 917                 if (!v || !br_vlan_should_use(v)) {
 918                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 919                         return -EINVAL;
 920                 }
 921
 922                 /* VID was specified, so use it. */
 923                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 924         } else {
 925                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 926                 if (err || !vg || !vg->num_vlans)
 927                         goto out;
 928
 929                 /* We have vlans configured on this port and user didn't
 930                  * specify a VLAN.  To be nice, add/update entry for every
 931                  * vlan on this port.
 932                  */
 933                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 934                         if (!br_vlan_should_use(v))
 935                                 continue;
 936                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 937                         if (err)
 938                                 goto out;
 939                 }
 940         }
 941
 942 out:
 943         return err;
 944 }
 945
 946 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 947                                        const struct net_bridge_port *p,
 948                                        const u8 *addr, u16 vlan)
 949 {
 950         struct net_bridge_fdb_entry *fdb;
 951
 952         fdb = br_fdb_find(br, addr, vlan);
 953         if (!fdb || fdb->dst != p)
 954                 return -ENOENT;
 955
 956         fdb_delete(br, fdb);
 957
 958         return 0;
 959 }
 960
 961 static int __br_fdb_delete(struct net_bridge *br,
 962                            const struct net_bridge_port *p,
 963                            const unsigned char *addr, u16 vid)
 964 {
 965         int err;
 966
 967         spin_lock_bh(&br->hash_lock);
 968         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 969         spin_unlock_bh(&br->hash_lock);
 970
 971         return err;
 972 }
 973
 974 /* Remove neighbor entry with RTM_DELNEIGH */
 975 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 976                   struct net_device *dev,
 977                   const unsigned char *addr, u16 vid)
 978 {
 979         struct net_bridge_vlan_group *vg;
 980         struct net_bridge_port *p = NULL;
 981         struct net_bridge_vlan *v;
 982         struct net_bridge *br;
 983         int err;
 984
 985         if (dev->priv_flags & IFF_EBRIDGE) {
 986                 br = netdev_priv(dev);
 987                 vg = br_vlan_group(br);
 988         } else {
 989                 p = br_port_get_rtnl(dev);
 990                 if (!p) {
 991                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 992                                 dev->name);
 993                         return -EINVAL;
 994                 }
 995                 vg = nbp_vlan_group(p);
 996                 br = p->br;
 997         }
 998
 999         if (vid) {
1000                 v = br_vlan_find(vg, vid);
1001                 if (!v) {
1002                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1003                         return -EINVAL;
1004                 }
1005
1006                 err = __br_fdb_delete(br, p, addr, vid);
1007         } else {
1008                 err = -ENOENT;
1009                 err &= __br_fdb_delete(br, p, addr, 0);
1010                 if (!vg || !vg->num_vlans)
1011                         return err;
1012
1013                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1014                         if (!br_vlan_should_use(v))
1015                                 continue;
1016                         err &= __br_fdb_delete(br, p, addr, v->vid);
1017                 }
1018         }
1019
1020         return err;
1021 }
1022
1023 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1024 {
1025         struct net_bridge_fdb_entry *fdb, *tmp;
1026         int i;
1027         int err;
1028
1029         ASSERT_RTNL();
1030
1031         for (i = 0; i < BR_HASH_SIZE; i++) {
1032                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1033                         /* We only care for static entries */
1034                         if (!fdb->is_static)
1035                                 continue;
1036
1037                         err = dev_uc_add(p->dev, fdb->addr.addr);
1038                         if (err)
1039                                 goto rollback;
1040                 }
1041         }
1042         return 0;
1043
1044 rollback:
1045         for (i = 0; i < BR_HASH_SIZE; i++) {
1046                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1047                         /* If we reached the fdb that failed, we can stop */
1048                         if (tmp == fdb)
1049                                 break;
1050
1051                         /* We only care for static entries */
1052                         if (!tmp->is_static)
1053                                 continue;
1054
1055                         dev_uc_del(p->dev, tmp->addr.addr);
1056                 }
1057         }
1058         return err;
1059 }
1060
1061 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1062 {
1063         struct net_bridge_fdb_entry *fdb;
1064         int i;
1065
1066         ASSERT_RTNL();
1067
1068         for (i = 0; i < BR_HASH_SIZE; i++) {
1069                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1070                         /* We only care for static entries */
1071                         if (!fdb->is_static)
1072                                 continue;
1073
1074                         dev_uc_del(p->dev, fdb->addr.addr);
1075                 }
1076         }
1077 }
1078
1079 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1080                               const unsigned char *addr, u16 vid)
1081 {
1082         struct net_bridge_fdb_entry *fdb;
1083         struct hlist_head *head;
1084         bool modified = false;
1085         int err = 0;
1086
1087         spin_lock_bh(&br->hash_lock);
1088
1089         head = &br->hash[br_mac_hash(addr, vid)];
1090         fdb = br_fdb_find(br, addr, vid);
1091         if (!fdb) {
1092                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1093                 if (!fdb) {
1094                         err = -ENOMEM;
1095                         goto err_unlock;
1096                 }
1097                 fdb->added_by_external_learn = 1;
1098                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1099         } else {
1100                 fdb->updated = jiffies;
1101
1102                 if (fdb->dst != p) {
1103                         fdb->dst = p;
1104                         modified = true;
1105                 }
1106
1107                 if (fdb->added_by_external_learn) {
1108                         /* Refresh entry */
1109                         fdb->used = jiffies;
1110                 } else if (!fdb->added_by_user) {
1111                         /* Take over SW learned entry */
1112                         fdb->added_by_external_learn = 1;
1113                         modified = true;
1114                 }
1115
1116                 if (modified)
1117                         fdb_notify(br, fdb, RTM_NEWNEIGH);
1118         }
1119
1120 err_unlock:
1121         spin_unlock_bh(&br->hash_lock);
1122
1123         return err;
1124 }
1125
1126 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1127                               const unsigned char *addr, u16 vid)
1128 {
1129         struct net_bridge_fdb_entry *fdb;
1130         int err = 0;
1131
1132         spin_lock_bh(&br->hash_lock);
1133
1134         fdb = br_fdb_find(br, addr, vid);
1135         if (fdb && fdb->added_by_external_learn)
1136                 fdb_delete(br, fdb);
1137         else
1138                 err = -ENOENT;
1139
1140         spin_unlock_bh(&br->hash_lock);
1141
1142         return err;
1143 }
1144
1145 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1146                           const unsigned char *addr, u16 vid)
1147 {
1148         struct net_bridge_fdb_entry *fdb;
1149
1150         spin_lock_bh(&br->hash_lock);
1151
1152         fdb = br_fdb_find(br, addr, vid);
1153         if (fdb)
1154                 fdb->offloaded = 1;
1155
1156         spin_unlock_bh(&br->hash_lock);
1157 }