net/bridge/br_fdb.c

   1 /*
   2  *      Forwarding database
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/rculist.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/times.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/jhash.h>
  22 #include <linux/random.h>
  23 #include <linux/slab.h>
  24 #include <linux/atomic.h>
  25 #include <asm/unaligned.h>
  26 #include <linux/if_vlan.h>
  27 #include <net/switchdev.h>
  28 #include <trace/events/bridge.h>
  29 #include "br_private.h"
  30
  31 static const struct rhashtable_params br_fdb_rht_params = {
  32         .head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
  33         .key_offset = offsetof(struct net_bridge_fdb_entry, key),
  34         .key_len = sizeof(struct net_bridge_fdb_key),
  35         .automatic_shrinking = true,
  36         .locks_mul = 1,
  37 };
  38
  39 static struct kmem_cache *br_fdb_cache __read_mostly;
  40 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  41                       const unsigned char *addr, u16 vid);
  42 static void fdb_notify(struct net_bridge *br,
  43                        const struct net_bridge_fdb_entry *, int, bool);
  44
  45 int __init br_fdb_init(void)
  46 {
  47         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  48                                          sizeof(struct net_bridge_fdb_entry),
  49                                          0,
  50                                          SLAB_HWCACHE_ALIGN, NULL);
  51         if (!br_fdb_cache)
  52                 return -ENOMEM;
  53
  54         return 0;
  55 }
  56
  57 void br_fdb_fini(void)
  58 {
  59         kmem_cache_destroy(br_fdb_cache);
  60 }
  61
  62 int br_fdb_hash_init(struct net_bridge *br)
  63 {
  64         return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
  65 }
  66
  67 void br_fdb_hash_fini(struct net_bridge *br)
  68 {
  69         rhashtable_destroy(&br->fdb_hash_tbl);
  70 }
  71
  72 /* if topology_changing then use forward_delay (default 15 sec)
  73  * otherwise keep longer (default 5 minutes)
  74  */
  75 static inline unsigned long hold_time(const struct net_bridge *br)
  76 {
  77         return br->topology_change ? br->forward_delay : br->ageing_time;
  78 }
  79
  80 static inline int has_expired(const struct net_bridge *br,
  81                                   const struct net_bridge_fdb_entry *fdb)
  82 {
  83         return !fdb->is_static && !fdb->added_by_external_learn &&
  84                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  85 }
  86
  87 static void fdb_rcu_free(struct rcu_head *head)
  88 {
  89         struct net_bridge_fdb_entry *ent
  90                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  91         kmem_cache_free(br_fdb_cache, ent);
  92 }
  93
  94 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
  95                                                  const unsigned char *addr,
  96                                                  __u16 vid)
  97 {
  98         struct net_bridge_fdb_key key;
  99
 100         WARN_ON_ONCE(!rcu_read_lock_held());
 101
 102         key.vlan_id = vid;
 103         memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
 104
 105         return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
 106 }
 107
 108 /* requires bridge hash_lock */
 109 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 110                                                 const unsigned char *addr,
 111                                                 __u16 vid)
 112 {
 113         struct net_bridge_fdb_entry *fdb;
 114
 115         lockdep_assert_held_once(&br->hash_lock);
 116
 117         rcu_read_lock();
 118         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 119         rcu_read_unlock();
 120
 121         return fdb;
 122 }
 123
 124 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
 125                                     const unsigned char *addr,
 126                                     __u16 vid)
 127 {
 128         struct net_bridge_fdb_entry *f;
 129         struct net_device *dev = NULL;
 130         struct net_bridge *br;
 131
 132         ASSERT_RTNL();
 133
 134         if (!netif_is_bridge_master(br_dev))
 135                 return NULL;
 136
 137         br = netdev_priv(br_dev);
 138         rcu_read_lock();
 139         f = br_fdb_find_rcu(br, addr, vid);
 140         if (f && f->dst)
 141                 dev = f->dst->dev;
 142         rcu_read_unlock();
 143
 144         return dev;
 145 }
 146 EXPORT_SYMBOL_GPL(br_fdb_find_port);
 147
 148 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 149                                              const unsigned char *addr,
 150                                              __u16 vid)
 151 {
 152         return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 153 }
 154
 155 /* When a static FDB entry is added, the mac address from the entry is
 156  * added to the bridge private HW address list and all required ports
 157  * are then updated with the new information.
 158  * Called under RTNL.
 159  */
 160 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 161 {
 162         int err;
 163         struct net_bridge_port *p;
 164
 165         ASSERT_RTNL();
 166
 167         list_for_each_entry(p, &br->port_list, list) {
 168                 if (!br_promisc_port(p)) {
 169                         err = dev_uc_add(p->dev, addr);
 170                         if (err)
 171                                 goto undo;
 172                 }
 173         }
 174
 175         return;
 176 undo:
 177         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 178                 if (!br_promisc_port(p))
 179                         dev_uc_del(p->dev, addr);
 180         }
 181 }
 182
 183 /* When a static FDB entry is deleted, the HW address from that entry is
 184  * also removed from the bridge private HW address list and updates all
 185  * the ports with needed information.
 186  * Called under RTNL.
 187  */
 188 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 189 {
 190         struct net_bridge_port *p;
 191
 192         ASSERT_RTNL();
 193
 194         list_for_each_entry(p, &br->port_list, list) {
 195                 if (!br_promisc_port(p))
 196                         dev_uc_del(p->dev, addr);
 197         }
 198 }
 199
 200 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 201                        bool swdev_notify)
 202 {
 203         trace_fdb_delete(br, f);
 204
 205         if (f->is_static)
 206                 fdb_del_hw_addr(br, f->key.addr.addr);
 207
 208         hlist_del_init_rcu(&f->fdb_node);
 209         rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
 210                                br_fdb_rht_params);
 211         fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
 212         call_rcu(&f->rcu, fdb_rcu_free);
 213 }
 214
 215 /* Delete a local entry if no other port had the same address. */
 216 static void fdb_delete_local(struct net_bridge *br,
 217                              const struct net_bridge_port *p,
 218                              struct net_bridge_fdb_entry *f)
 219 {
 220         const unsigned char *addr = f->key.addr.addr;
 221         struct net_bridge_vlan_group *vg;
 222         const struct net_bridge_vlan *v;
 223         struct net_bridge_port *op;
 224         u16 vid = f->key.vlan_id;
 225
 226         /* Maybe another port has same hw addr? */
 227         list_for_each_entry(op, &br->port_list, list) {
 228                 vg = nbp_vlan_group(op);
 229                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 230                     (!vid || br_vlan_find(vg, vid))) {
 231                         f->dst = op;
 232                         f->added_by_user = 0;
 233                         return;
 234                 }
 235         }
 236
 237         vg = br_vlan_group(br);
 238         v = br_vlan_find(vg, vid);
 239         /* Maybe bridge device has same hw addr? */
 240         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 241             (!vid || (v && br_vlan_should_use(v)))) {
 242                 f->dst = NULL;
 243                 f->added_by_user = 0;
 244                 return;
 245         }
 246
 247         fdb_delete(br, f, true);
 248 }
 249
 250 void br_fdb_find_delete_local(struct net_bridge *br,
 251                               const struct net_bridge_port *p,
 252                               const unsigned char *addr, u16 vid)
 253 {
 254         struct net_bridge_fdb_entry *f;
 255
 256         spin_lock_bh(&br->hash_lock);
 257         f = br_fdb_find(br, addr, vid);
 258         if (f && f->is_local && !f->added_by_user && f->dst == p)
 259                 fdb_delete_local(br, p, f);
 260         spin_unlock_bh(&br->hash_lock);
 261 }
 262
 263 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 264 {
 265         struct net_bridge_vlan_group *vg;
 266         struct net_bridge_fdb_entry *f;
 267         struct net_bridge *br = p->br;
 268         struct net_bridge_vlan *v;
 269
 270         spin_lock_bh(&br->hash_lock);
 271         vg = nbp_vlan_group(p);
 272         hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
 273                 if (f->dst == p && f->is_local && !f->added_by_user) {
 274                         /* delete old one */
 275                         fdb_delete_local(br, p, f);
 276
 277                         /* if this port has no vlan information
 278                          * configured, we can safely be done at
 279                          * this point.
 280                          */
 281                         if (!vg || !vg->num_vlans)
 282                                 goto insert;
 283                 }
 284         }
 285
 286 insert:
 287         /* insert new address,  may fail if invalid address or dup. */
 288         fdb_insert(br, p, newaddr, 0);
 289
 290         if (!vg || !vg->num_vlans)
 291                 goto done;
 292
 293         /* Now add entries for every VLAN configured on the port.
 294          * This function runs under RTNL so the bitmap will not change
 295          * from under us.
 296          */
 297         list_for_each_entry(v, &vg->vlan_list, vlist)
 298                 fdb_insert(br, p, newaddr, v->vid);
 299
 300 done:
 301         spin_unlock_bh(&br->hash_lock);
 302 }
 303
 304 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 305 {
 306         struct net_bridge_vlan_group *vg;
 307         struct net_bridge_fdb_entry *f;
 308         struct net_bridge_vlan *v;
 309
 310         spin_lock_bh(&br->hash_lock);
 311
 312         /* If old entry was unassociated with any port, then delete it. */
 313         f = br_fdb_find(br, br->dev->dev_addr, 0);
 314         if (f && f->is_local && !f->dst && !f->added_by_user)
 315                 fdb_delete_local(br, NULL, f);
 316
 317         fdb_insert(br, NULL, newaddr, 0);
 318         vg = br_vlan_group(br);
 319         if (!vg || !vg->num_vlans)
 320                 goto out;
 321         /* Now remove and add entries for every VLAN configured on the
 322          * bridge.  This function runs under RTNL so the bitmap will not
 323          * change from under us.
 324          */
 325         list_for_each_entry(v, &vg->vlan_list, vlist) {
 326                 if (!br_vlan_should_use(v))
 327                         continue;
 328                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 329                 if (f && f->is_local && !f->dst && !f->added_by_user)
 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 (f->is_static || f->added_by_external_learn)
 355                         continue;
 356                 this_timer = f->updated + delay;
 357                 if (time_after(this_timer, now)) {
 358                         work_delay = min(work_delay, this_timer - now);
 359                 } else {
 360                         spin_lock_bh(&br->hash_lock);
 361                         if (!hlist_unhashed(&f->fdb_node))
 362                                 fdb_delete(br, f, true);
 363                         spin_unlock_bh(&br->hash_lock);
 364                 }
 365         }
 366         rcu_read_unlock();
 367
 368         /* Cleanup minimum 10 milliseconds apart */
 369         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 370         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 371 }
 372
 373 /* Completely flush all dynamic entries in forwarding database.*/
 374 void br_fdb_flush(struct net_bridge *br)
 375 {
 376         struct net_bridge_fdb_entry *f;
 377         struct hlist_node *tmp;
 378
 379         spin_lock_bh(&br->hash_lock);
 380         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 381                 if (!f->is_static)
 382                         fdb_delete(br, f, true);
 383         }
 384         spin_unlock_bh(&br->hash_lock);
 385 }
 386
 387 /* Flush all entries referring to a specific port.
 388  * if do_all is set also flush static entries
 389  * if vid is set delete all entries that match the vlan_id
 390  */
 391 void br_fdb_delete_by_port(struct net_bridge *br,
 392                            const struct net_bridge_port *p,
 393                            u16 vid,
 394                            int do_all)
 395 {
 396         struct net_bridge_fdb_entry *f;
 397         struct hlist_node *tmp;
 398
 399         spin_lock_bh(&br->hash_lock);
 400         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 401                 if (f->dst != p)
 402                         continue;
 403
 404                 if (!do_all)
 405                         if (f->is_static || (vid && f->key.vlan_id != vid))
 406                                 continue;
 407
 408                 if (f->is_local)
 409                         fdb_delete_local(br, p, f);
 410                 else
 411                         fdb_delete(br, f, true);
 412         }
 413         spin_unlock_bh(&br->hash_lock);
 414 }
 415
 416 #if IS_ENABLED(CONFIG_ATM_LANE)
 417 /* Interface used by ATM LANE hook to test
 418  * if an addr is on some other bridge port */
 419 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 420 {
 421         struct net_bridge_fdb_entry *fdb;
 422         struct net_bridge_port *port;
 423         int ret;
 424
 425         rcu_read_lock();
 426         port = br_port_get_rcu(dev);
 427         if (!port)
 428                 ret = 0;
 429         else {
 430                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 431                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 432                         fdb->dst->state == BR_STATE_FORWARDING;
 433         }
 434         rcu_read_unlock();
 435
 436         return ret;
 437 }
 438 #endif /* CONFIG_ATM_LANE */
 439
 440 /*
 441  * Fill buffer with forwarding table records in
 442  * the API format.
 443  */
 444 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 445                    unsigned long maxnum, unsigned long skip)
 446 {
 447         struct net_bridge_fdb_entry *f;
 448         struct __fdb_entry *fe = buf;
 449         int num = 0;
 450
 451         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 452
 453         rcu_read_lock();
 454         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 455                 if (num >= maxnum)
 456                         break;
 457
 458                 if (has_expired(br, f))
 459                         continue;
 460
 461                 /* ignore pseudo entry for local MAC address */
 462                 if (!f->dst)
 463                         continue;
 464
 465                 if (skip) {
 466                         --skip;
 467                         continue;
 468                 }
 469
 470                 /* convert from internal format to API */
 471                 memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
 472
 473                 /* due to ABI compat need to split into hi/lo */
 474                 fe->port_no = f->dst->port_no;
 475                 fe->port_hi = f->dst->port_no >> 8;
 476
 477                 fe->is_local = f->is_local;
 478                 if (!f->is_static)
 479                         fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 480                 ++fe;
 481                 ++num;
 482         }
 483         rcu_read_unlock();
 484
 485         return num;
 486 }
 487
 488 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
 489                                                struct net_bridge_port *source,
 490                                                const unsigned char *addr,
 491                                                __u16 vid,
 492                                                unsigned char is_local,
 493                                                unsigned char is_static)
 494 {
 495         struct net_bridge_fdb_entry *fdb;
 496
 497         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 498         if (fdb) {
 499                 memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
 500                 fdb->dst = source;
 501                 fdb->key.vlan_id = vid;
 502                 fdb->is_local = is_local;
 503                 fdb->is_static = is_static;
 504                 fdb->added_by_user = 0;
 505                 fdb->added_by_external_learn = 0;
 506                 fdb->offloaded = 0;
 507                 fdb->updated = fdb->used = jiffies;
 508                 if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
 509                                                   &fdb->rhnode,
 510                                                   br_fdb_rht_params)) {
 511                         kmem_cache_free(br_fdb_cache, fdb);
 512                         fdb = NULL;
 513                 } else {
 514                         hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
 515                 }
 516         }
 517         return fdb;
 518 }
 519
 520 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 521                   const unsigned char *addr, u16 vid)
 522 {
 523         struct net_bridge_fdb_entry *fdb;
 524
 525         if (!is_valid_ether_addr(addr))
 526                 return -EINVAL;
 527
 528         fdb = br_fdb_find(br, addr, vid);
 529         if (fdb) {
 530                 /* it is okay to have multiple ports with same
 531                  * address, just use the first one.
 532                  */
 533                 if (fdb->is_local)
 534                         return 0;
 535                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 536                        source ? source->dev->name : br->dev->name, addr, vid);
 537                 fdb_delete(br, fdb, true);
 538         }
 539
 540         fdb = fdb_create(br, source, addr, vid, 1, 1);
 541         if (!fdb)
 542                 return -ENOMEM;
 543
 544         fdb_add_hw_addr(br, addr);
 545         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 546         return 0;
 547 }
 548
 549 /* Add entry for local address of interface */
 550 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 551                   const unsigned char *addr, u16 vid)
 552 {
 553         int ret;
 554
 555         spin_lock_bh(&br->hash_lock);
 556         ret = fdb_insert(br, source, addr, vid);
 557         spin_unlock_bh(&br->hash_lock);
 558         return ret;
 559 }
 560
 561 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 562                    const unsigned char *addr, u16 vid, bool added_by_user)
 563 {
 564         struct net_bridge_fdb_entry *fdb;
 565         bool fdb_modified = false;
 566
 567         /* some users want to always flood. */
 568         if (hold_time(br) == 0)
 569                 return;
 570
 571         /* ignore packets unless we are using this port */
 572         if (!(source->state == BR_STATE_LEARNING ||
 573               source->state == BR_STATE_FORWARDING))
 574                 return;
 575
 576         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 577         if (likely(fdb)) {
 578                 /* attempt to update an entry for a local interface */
 579                 if (unlikely(fdb->is_local)) {
 580                         if (net_ratelimit())
 581                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 582                                         source->dev->name, addr, vid);
 583                 } else {
 584                         unsigned long now = jiffies;
 585
 586                         /* fastpath: update of existing entry */
 587                         if (unlikely(source != fdb->dst)) {
 588                                 fdb->dst = source;
 589                                 fdb_modified = true;
 590                                 /* Take over HW learned entry */
 591                                 if (unlikely(fdb->added_by_external_learn))
 592                                         fdb->added_by_external_learn = 0;
 593                         }
 594                         if (now != fdb->updated)
 595                                 fdb->updated = now;
 596                         if (unlikely(added_by_user))
 597                                 fdb->added_by_user = 1;
 598                         if (unlikely(fdb_modified)) {
 599                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 600                                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 601                         }
 602                 }
 603         } else {
 604                 spin_lock(&br->hash_lock);
 605                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 606                 if (fdb) {
 607                         if (unlikely(added_by_user))
 608                                 fdb->added_by_user = 1;
 609                         trace_br_fdb_update(br, source, addr, vid,
 610                                             added_by_user);
 611                         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 612                 }
 613                 /* else  we lose race and someone else inserts
 614                  * it first, don't bother updating
 615                  */
 616                 spin_unlock(&br->hash_lock);
 617         }
 618 }
 619
 620 static int fdb_to_nud(const struct net_bridge *br,
 621                       const struct net_bridge_fdb_entry *fdb)
 622 {
 623         if (fdb->is_local)
 624                 return NUD_PERMANENT;
 625         else if (fdb->is_static)
 626                 return NUD_NOARP;
 627         else if (has_expired(br, fdb))
 628                 return NUD_STALE;
 629         else
 630                 return NUD_REACHABLE;
 631 }
 632
 633 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 634                          const struct net_bridge_fdb_entry *fdb,
 635                          u32 portid, u32 seq, int type, unsigned int flags)
 636 {
 637         unsigned long now = jiffies;
 638         struct nda_cacheinfo ci;
 639         struct nlmsghdr *nlh;
 640         struct ndmsg *ndm;
 641
 642         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 643         if (nlh == NULL)
 644                 return -EMSGSIZE;
 645
 646         ndm = nlmsg_data(nlh);
 647         ndm->ndm_family  = AF_BRIDGE;
 648         ndm->ndm_pad1    = 0;
 649         ndm->ndm_pad2    = 0;
 650         ndm->ndm_flags   = 0;
 651         ndm->ndm_type    = 0;
 652         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 653         ndm->ndm_state   = fdb_to_nud(br, fdb);
 654
 655         if (fdb->offloaded)
 656                 ndm->ndm_flags |= NTF_OFFLOADED;
 657         if (fdb->added_by_external_learn)
 658                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 659
 660         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 661                 goto nla_put_failure;
 662         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 663                 goto nla_put_failure;
 664         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 665         ci.ndm_confirmed = 0;
 666         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 667         ci.ndm_refcnt    = 0;
 668         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 669                 goto nla_put_failure;
 670
 671         if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 672                                         &fdb->key.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                        bool swdev_notify)
 695 {
 696         struct net *net = dev_net(br->dev);
 697         struct sk_buff *skb;
 698         int err = -ENOBUFS;
 699
 700         if (swdev_notify)
 701                 br_switchdev_fdb_notify(fdb, type);
 702
 703         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 704         if (skb == NULL)
 705                 goto errout;
 706
 707         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 708         if (err < 0) {
 709                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 710                 WARN_ON(err == -EMSGSIZE);
 711                 kfree_skb(skb);
 712                 goto errout;
 713         }
 714         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 715         return;
 716 errout:
 717         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 718 }
 719
 720 /* Dump information about entries, in response to GETNEIGH */
 721 int br_fdb_dump(struct sk_buff *skb,
 722                 struct netlink_callback *cb,
 723                 struct net_device *dev,
 724                 struct net_device *filter_dev,
 725                 int *idx)
 726 {
 727         struct net_bridge *br = netdev_priv(dev);
 728         struct net_bridge_fdb_entry *f;
 729         int err = 0;
 730
 731         if (!(dev->priv_flags & IFF_EBRIDGE))
 732                 return err;
 733
 734         if (!filter_dev) {
 735                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 736                 if (err < 0)
 737                         return err;
 738         }
 739
 740         rcu_read_lock();
 741         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 742                 if (*idx < cb->args[2])
 743                         goto skip;
 744                 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 745                         if (filter_dev != dev)
 746                                 goto skip;
 747                         /* !f->dst is a special case for bridge
 748                          * It means the MAC belongs to the bridge
 749                          * Therefore need a little more filtering
 750                          * we only want to dump the !f->dst case
 751                          */
 752                         if (f->dst)
 753                                 goto skip;
 754                 }
 755                 if (!filter_dev && f->dst)
 756                         goto skip;
 757
 758                 err = fdb_fill_info(skb, br, f,
 759                                     NETLINK_CB(cb->skb).portid,
 760                                     cb->nlh->nlmsg_seq,
 761                                     RTM_NEWNEIGH,
 762                                     NLM_F_MULTI);
 763                 if (err < 0)
 764                         break;
 765 skip:
 766                 *idx += 1;
 767         }
 768         rcu_read_unlock();
 769
 770         return err;
 771 }
 772
 773 /* Update (create or replace) forwarding database entry */
 774 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 775                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 776 {
 777         struct net_bridge_fdb_entry *fdb;
 778         bool modified = false;
 779
 780         /* If the port cannot learn allow only local and static entries */
 781         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 782             !(source->state == BR_STATE_LEARNING ||
 783               source->state == BR_STATE_FORWARDING))
 784                 return -EPERM;
 785
 786         if (!source && !(state & NUD_PERMANENT)) {
 787                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 788                         br->dev->name);
 789                 return -EINVAL;
 790         }
 791
 792         fdb = br_fdb_find(br, addr, vid);
 793         if (fdb == NULL) {
 794                 if (!(flags & NLM_F_CREATE))
 795                         return -ENOENT;
 796
 797                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 798                 if (!fdb)
 799                         return -ENOMEM;
 800
 801                 modified = true;
 802         } else {
 803                 if (flags & NLM_F_EXCL)
 804                         return -EEXIST;
 805
 806                 if (fdb->dst != source) {
 807                         fdb->dst = source;
 808                         modified = true;
 809                 }
 810         }
 811
 812         if (fdb_to_nud(br, fdb) != state) {
 813                 if (state & NUD_PERMANENT) {
 814                         fdb->is_local = 1;
 815                         if (!fdb->is_static) {
 816                                 fdb->is_static = 1;
 817                                 fdb_add_hw_addr(br, addr);
 818                         }
 819                 } else if (state & NUD_NOARP) {
 820                         fdb->is_local = 0;
 821                         if (!fdb->is_static) {
 822                                 fdb->is_static = 1;
 823                                 fdb_add_hw_addr(br, addr);
 824                         }
 825                 } else {
 826                         fdb->is_local = 0;
 827                         if (fdb->is_static) {
 828                                 fdb->is_static = 0;
 829                                 fdb_del_hw_addr(br, addr);
 830                         }
 831                 }
 832
 833                 modified = true;
 834         }
 835         fdb->added_by_user = 1;
 836
 837         fdb->used = jiffies;
 838         if (modified) {
 839                 fdb->updated = jiffies;
 840                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 841         }
 842
 843         return 0;
 844 }
 845
 846 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 847                         struct net_bridge_port *p, const unsigned char *addr,
 848                         u16 nlh_flags, u16 vid)
 849 {
 850         int err = 0;
 851
 852         if (ndm->ndm_flags & NTF_USE) {
 853                 if (!p) {
 854                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 855                                 br->dev->name);
 856                         return -EINVAL;
 857                 }
 858                 local_bh_disable();
 859                 rcu_read_lock();
 860                 br_fdb_update(br, p, addr, vid, true);
 861                 rcu_read_unlock();
 862                 local_bh_enable();
 863         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 864                 err = br_fdb_external_learn_add(br, p, addr, vid, true);
 865         } else {
 866                 spin_lock_bh(&br->hash_lock);
 867                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 868                                     nlh_flags, vid);
 869                 spin_unlock_bh(&br->hash_lock);
 870         }
 871
 872         return err;
 873 }
 874
 875 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 876 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 877                struct net_device *dev,
 878                const unsigned char *addr, u16 vid, u16 nlh_flags)
 879 {
 880         struct net_bridge_vlan_group *vg;
 881         struct net_bridge_port *p = NULL;
 882         struct net_bridge_vlan *v;
 883         struct net_bridge *br = NULL;
 884         int err = 0;
 885
 886         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 887
 888         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 889                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 890                 return -EINVAL;
 891         }
 892
 893         if (is_zero_ether_addr(addr)) {
 894                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 895                 return -EINVAL;
 896         }
 897
 898         if (dev->priv_flags & IFF_EBRIDGE) {
 899                 br = netdev_priv(dev);
 900                 vg = br_vlan_group(br);
 901         } else {
 902                 p = br_port_get_rtnl(dev);
 903                 if (!p) {
 904                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 905                                 dev->name);
 906                         return -EINVAL;
 907                 }
 908                 br = p->br;
 909                 vg = nbp_vlan_group(p);
 910         }
 911
 912         if (vid) {
 913                 v = br_vlan_find(vg, vid);
 914                 if (!v || !br_vlan_should_use(v)) {
 915                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 916                         return -EINVAL;
 917                 }
 918
 919                 /* VID was specified, so use it. */
 920                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 921         } else {
 922                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 923                 if (err || !vg || !vg->num_vlans)
 924                         goto out;
 925
 926                 /* We have vlans configured on this port and user didn't
 927                  * specify a VLAN.  To be nice, add/update entry for every
 928                  * vlan on this port.
 929                  */
 930                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 931                         if (!br_vlan_should_use(v))
 932                                 continue;
 933                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 934                         if (err)
 935                                 goto out;
 936                 }
 937         }
 938
 939 out:
 940         return err;
 941 }
 942
 943 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 944                                        const struct net_bridge_port *p,
 945                                        const u8 *addr, u16 vlan)
 946 {
 947         struct net_bridge_fdb_entry *fdb;
 948
 949         fdb = br_fdb_find(br, addr, vlan);
 950         if (!fdb || fdb->dst != p)
 951                 return -ENOENT;
 952
 953         fdb_delete(br, fdb, true);
 954
 955         return 0;
 956 }
 957
 958 static int __br_fdb_delete(struct net_bridge *br,
 959                            const struct net_bridge_port *p,
 960                            const unsigned char *addr, u16 vid)
 961 {
 962         int err;
 963
 964         spin_lock_bh(&br->hash_lock);
 965         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 966         spin_unlock_bh(&br->hash_lock);
 967
 968         return err;
 969 }
 970
 971 /* Remove neighbor entry with RTM_DELNEIGH */
 972 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 973                   struct net_device *dev,
 974                   const unsigned char *addr, u16 vid)
 975 {
 976         struct net_bridge_vlan_group *vg;
 977         struct net_bridge_port *p = NULL;
 978         struct net_bridge_vlan *v;
 979         struct net_bridge *br;
 980         int err;
 981
 982         if (dev->priv_flags & IFF_EBRIDGE) {
 983                 br = netdev_priv(dev);
 984                 vg = br_vlan_group(br);
 985         } else {
 986                 p = br_port_get_rtnl(dev);
 987                 if (!p) {
 988                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 989                                 dev->name);
 990                         return -EINVAL;
 991                 }
 992                 vg = nbp_vlan_group(p);
 993                 br = p->br;
 994         }
 995
 996         if (vid) {
 997                 v = br_vlan_find(vg, vid);
 998                 if (!v) {
 999                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1000                         return -EINVAL;
1001                 }
1002
1003                 err = __br_fdb_delete(br, p, addr, vid);
1004         } else {
1005                 err = -ENOENT;
1006                 err &= __br_fdb_delete(br, p, addr, 0);
1007                 if (!vg || !vg->num_vlans)
1008                         return err;
1009
1010                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1011                         if (!br_vlan_should_use(v))
1012                                 continue;
1013                         err &= __br_fdb_delete(br, p, addr, v->vid);
1014                 }
1015         }
1016
1017         return err;
1018 }
1019
1020 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1021 {
1022         struct net_bridge_fdb_entry *f, *tmp;
1023         int err = 0;
1024
1025         ASSERT_RTNL();
1026
1027         /* the key here is that static entries change only under rtnl */
1028         rcu_read_lock();
1029         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1030                 /* We only care for static entries */
1031                 if (!f->is_static)
1032                         continue;
1033                 err = dev_uc_add(p->dev, f->key.addr.addr);
1034                 if (err)
1035                         goto rollback;
1036         }
1037 done:
1038         rcu_read_unlock();
1039
1040         return err;
1041
1042 rollback:
1043         hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1044                 /* We only care for static entries */
1045                 if (!tmp->is_static)
1046                         continue;
1047                 if (tmp == f)
1048                         break;
1049                 dev_uc_del(p->dev, tmp->key.addr.addr);
1050         }
1051
1052         goto done;
1053 }
1054
1055 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1056 {
1057         struct net_bridge_fdb_entry *f;
1058
1059         ASSERT_RTNL();
1060
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 (!f->is_static)
1065                         continue;
1066
1067                 dev_uc_del(p->dev, f->key.addr.addr);
1068         }
1069         rcu_read_unlock();
1070 }
1071
1072 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1073                               const unsigned char *addr, u16 vid,
1074                               bool swdev_notify)
1075 {
1076         struct net_bridge_fdb_entry *fdb;
1077         bool modified = false;
1078         int err = 0;
1079
1080         trace_br_fdb_external_learn_add(br, p, addr, vid);
1081
1082         spin_lock_bh(&br->hash_lock);
1083
1084         fdb = br_fdb_find(br, addr, vid);
1085         if (!fdb) {
1086                 fdb = fdb_create(br, p, addr, vid, 0, 0);
1087                 if (!fdb) {
1088                         err = -ENOMEM;
1089                         goto err_unlock;
1090                 }
1091                 fdb->added_by_external_learn = 1;
1092                 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1093         } else {
1094                 fdb->updated = jiffies;
1095
1096                 if (fdb->dst != p) {
1097                         fdb->dst = p;
1098                         modified = true;
1099                 }
1100
1101                 if (fdb->added_by_external_learn) {
1102                         /* Refresh entry */
1103                         fdb->used = jiffies;
1104                 } else if (!fdb->added_by_user) {
1105                         /* Take over SW learned entry */
1106                         fdb->added_by_external_learn = 1;
1107                         modified = true;
1108                 }
1109
1110                 if (modified)
1111                         fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1112         }
1113
1114 err_unlock:
1115         spin_unlock_bh(&br->hash_lock);
1116
1117         return err;
1118 }
1119
1120 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1121                               const unsigned char *addr, u16 vid,
1122                               bool swdev_notify)
1123 {
1124         struct net_bridge_fdb_entry *fdb;
1125         int err = 0;
1126
1127         spin_lock_bh(&br->hash_lock);
1128
1129         fdb = br_fdb_find(br, addr, vid);
1130         if (fdb && fdb->added_by_external_learn)
1131                 fdb_delete(br, fdb, swdev_notify);
1132         else
1133                 err = -ENOENT;
1134
1135         spin_unlock_bh(&br->hash_lock);
1136
1137         return err;
1138 }
1139
1140 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1141                           const unsigned char *addr, u16 vid)
1142 {
1143         struct net_bridge_fdb_entry *fdb;
1144
1145         spin_lock_bh(&br->hash_lock);
1146
1147         fdb = br_fdb_find(br, addr, vid);
1148         if (fdb)
1149                 fdb->offloaded = 1;
1150
1151         spin_unlock_bh(&br->hash_lock);
1152 }