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