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         f = br_fdb_find(br, addr, vid);
 139         if (f && f->dst)
 140                 dev = f->dst->dev;
 141
 142         return dev;
 143 }
 144 EXPORT_SYMBOL_GPL(br_fdb_find_port);
 145
 146 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 147                                              const unsigned char *addr,
 148                                              __u16 vid)
 149 {
 150         return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 151 }
 152
 153 /* When a static FDB entry is added, the mac address from the entry is
 154  * added to the bridge private HW address list and all required ports
 155  * are then updated with the new information.
 156  * Called under RTNL.
 157  */
 158 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 159 {
 160         int err;
 161         struct net_bridge_port *p;
 162
 163         ASSERT_RTNL();
 164
 165         list_for_each_entry(p, &br->port_list, list) {
 166                 if (!br_promisc_port(p)) {
 167                         err = dev_uc_add(p->dev, addr);
 168                         if (err)
 169                                 goto undo;
 170                 }
 171         }
 172
 173         return;
 174 undo:
 175         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 176                 if (!br_promisc_port(p))
 177                         dev_uc_del(p->dev, addr);
 178         }
 179 }
 180
 181 /* When a static FDB entry is deleted, the HW address from that entry is
 182  * also removed from the bridge private HW address list and updates all
 183  * the ports with needed information.
 184  * Called under RTNL.
 185  */
 186 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 187 {
 188         struct net_bridge_port *p;
 189
 190         ASSERT_RTNL();
 191
 192         list_for_each_entry(p, &br->port_list, list) {
 193                 if (!br_promisc_port(p))
 194                         dev_uc_del(p->dev, addr);
 195         }
 196 }
 197
 198 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 199                        bool swdev_notify)
 200 {
 201         trace_fdb_delete(br, f);
 202
 203         if (f->is_static)
 204                 fdb_del_hw_addr(br, f->key.addr.addr);
 205
 206         hlist_del_init_rcu(&f->fdb_node);
 207         rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
 208                                br_fdb_rht_params);
 209         fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
 210         call_rcu(&f->rcu, fdb_rcu_free);
 211 }
 212
 213 /* Delete a local entry if no other port had the same address. */
 214 static void fdb_delete_local(struct net_bridge *br,
 215                              const struct net_bridge_port *p,
 216                              struct net_bridge_fdb_entry *f)
 217 {
 218         const unsigned char *addr = f->key.addr.addr;
 219         struct net_bridge_vlan_group *vg;
 220         const struct net_bridge_vlan *v;
 221         struct net_bridge_port *op;
 222         u16 vid = f->key.vlan_id;
 223
 224         /* Maybe another port has same hw addr? */
 225         list_for_each_entry(op, &br->port_list, list) {
 226                 vg = nbp_vlan_group(op);
 227                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 228                     (!vid || br_vlan_find(vg, vid))) {
 229                         f->dst = op;
 230                         f->added_by_user = 0;
 231                         return;
 232                 }
 233         }
 234
 235         vg = br_vlan_group(br);
 236         v = br_vlan_find(vg, vid);
 237         /* Maybe bridge device has same hw addr? */
 238         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 239             (!vid || (v && br_vlan_should_use(v)))) {
 240                 f->dst = NULL;
 241                 f->added_by_user = 0;
 242                 return;
 243         }
 244
 245         fdb_delete(br, f, true);
 246 }
 247
 248 void br_fdb_find_delete_local(struct net_bridge *br,
 249                               const struct net_bridge_port *p,
 250                               const unsigned char *addr, u16 vid)
 251 {
 252         struct net_bridge_fdb_entry *f;
 253
 254         spin_lock_bh(&br->hash_lock);
 255         f = br_fdb_find(br, addr, vid);
 256         if (f && f->is_local && !f->added_by_user && f->dst == p)
 257                 fdb_delete_local(br, p, f);
 258         spin_unlock_bh(&br->hash_lock);
 259 }
 260
 261 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 262 {
 263         struct net_bridge_vlan_group *vg;
 264         struct net_bridge_fdb_entry *f;
 265         struct net_bridge *br = p->br;
 266         struct net_bridge_vlan *v;
 267
 268         spin_lock_bh(&br->hash_lock);
 269         vg = nbp_vlan_group(p);
 270         hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
 271                 if (f->dst == p && f->is_local && !f->added_by_user) {
 272                         /* delete old one */
 273                         fdb_delete_local(br, p, f);
 274
 275                         /* if this port has no vlan information
 276                          * configured, we can safely be done at
 277                          * this point.
 278                          */
 279                         if (!vg || !vg->num_vlans)
 280                                 goto insert;
 281                 }
 282         }
 283
 284 insert:
 285         /* insert new address,  may fail if invalid address or dup. */
 286         fdb_insert(br, p, newaddr, 0);
 287
 288         if (!vg || !vg->num_vlans)
 289                 goto done;
 290
 291         /* Now add entries for every VLAN configured on the port.
 292          * This function runs under RTNL so the bitmap will not change
 293          * from under us.
 294          */
 295         list_for_each_entry(v, &vg->vlan_list, vlist)
 296                 fdb_insert(br, p, newaddr, v->vid);
 297
 298 done:
 299         spin_unlock_bh(&br->hash_lock);
 300 }
 301
 302 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 303 {
 304         struct net_bridge_vlan_group *vg;
 305         struct net_bridge_fdb_entry *f;
 306         struct net_bridge_vlan *v;
 307
 308         spin_lock_bh(&br->hash_lock);
 309
 310         /* If old entry was unassociated with any port, then delete it. */
 311         f = br_fdb_find(br, br->dev->dev_addr, 0);
 312         if (f && f->is_local && !f->dst && !f->added_by_user)
 313                 fdb_delete_local(br, NULL, f);
 314
 315         fdb_insert(br, NULL, newaddr, 0);
 316         vg = br_vlan_group(br);
 317         if (!vg || !vg->num_vlans)
 318                 goto out;
 319         /* Now remove and add entries for every VLAN configured on the
 320          * bridge.  This function runs under RTNL so the bitmap will not
 321          * change from under us.
 322          */
 323         list_for_each_entry(v, &vg->vlan_list, vlist) {
 324                 if (!br_vlan_should_use(v))
 325                         continue;
 326                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 327                 if (f && f->is_local && !f->dst && !f->added_by_user)
 328                         fdb_delete_local(br, NULL, f);
 329                 fdb_insert(br, NULL, newaddr, v->vid);
 330         }
 331 out:
 332         spin_unlock_bh(&br->hash_lock);
 333 }
 334
 335 void br_fdb_cleanup(struct work_struct *work)
 336 {
 337         struct net_bridge *br = container_of(work, struct net_bridge,
 338                                              gc_work.work);
 339         struct net_bridge_fdb_entry *f = NULL;
 340         unsigned long delay = hold_time(br);
 341         unsigned long work_delay = delay;
 342         unsigned long now = jiffies;
 343
 344         /* this part is tricky, in order to avoid blocking learning and
 345          * consequently forwarding, we rely on rcu to delete objects with
 346          * delayed freeing allowing us to continue traversing
 347          */
 348         rcu_read_lock();
 349         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 350                 unsigned long this_timer;
 351
 352                 if (f->is_static || 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                         spin_lock_bh(&br->hash_lock);
 359                         if (!hlist_unhashed(&f->fdb_node))
 360                                 fdb_delete(br, f, true);
 361                         spin_unlock_bh(&br->hash_lock);
 362                 }
 363         }
 364         rcu_read_unlock();
 365
 366         /* Cleanup minimum 10 milliseconds apart */
 367         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 368         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 369 }
 370
 371 /* Completely flush all dynamic entries in forwarding database.*/
 372 void br_fdb_flush(struct net_bridge *br)
 373 {
 374         struct net_bridge_fdb_entry *f;
 375         struct hlist_node *tmp;
 376
 377         spin_lock_bh(&br->hash_lock);
 378         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 379                 if (!f->is_static)
 380                         fdb_delete(br, f, true);
 381         }
 382         spin_unlock_bh(&br->hash_lock);
 383 }
 384
 385 /* Flush all entries referring to a specific port.
 386  * if do_all is set also flush static entries
 387  * if vid is set delete all entries that match the vlan_id
 388  */
 389 void br_fdb_delete_by_port(struct net_bridge *br,
 390                            const struct net_bridge_port *p,
 391                            u16 vid,
 392                            int do_all)
 393 {
 394         struct net_bridge_fdb_entry *f;
 395         struct hlist_node *tmp;
 396
 397         spin_lock_bh(&br->hash_lock);
 398         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 399                 if (f->dst != p)
 400                         continue;
 401
 402                 if (!do_all)
 403                         if (f->is_static || (vid && f->key.vlan_id != vid))
 404                                 continue;
 405
 406                 if (f->is_local)
 407                         fdb_delete_local(br, p, f);
 408                 else
 409                         fdb_delete(br, f, true);
 410         }
 411         spin_unlock_bh(&br->hash_lock);
 412 }
 413
 414 #if IS_ENABLED(CONFIG_ATM_LANE)
 415 /* Interface used by ATM LANE hook to test
 416  * if an addr is on some other bridge port */
 417 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 418 {
 419         struct net_bridge_fdb_entry *fdb;
 420         struct net_bridge_port *port;
 421         int ret;
 422
 423         rcu_read_lock();
 424         port = br_port_get_rcu(dev);
 425         if (!port)
 426                 ret = 0;
 427         else {
 428                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 429                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 430                         fdb->dst->state == BR_STATE_FORWARDING;
 431         }
 432         rcu_read_unlock();
 433
 434         return ret;
 435 }
 436 #endif /* CONFIG_ATM_LANE */
 437
 438 /*
 439  * Fill buffer with forwarding table records in
 440  * the API format.
 441  */
 442 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 443                    unsigned long maxnum, unsigned long skip)
 444 {
 445         struct net_bridge_fdb_entry *f;
 446         struct __fdb_entry *fe = buf;
 447         int num = 0;
 448
 449         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 450
 451         rcu_read_lock();
 452         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 453                 if (num >= maxnum)
 454                         break;
 455
 456                 if (has_expired(br, f))
 457                         continue;
 458
 459                 /* ignore pseudo entry for local MAC address */
 460                 if (!f->dst)
 461                         continue;
 462
 463                 if (skip) {
 464                         --skip;
 465                         continue;
 466                 }
 467
 468                 /* convert from internal format to API */
 469                 memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
 470
 471                 /* due to ABI compat need to split into hi/lo */
 472                 fe->port_no = f->dst->port_no;
 473                 fe->port_hi = f->dst->port_no >> 8;
 474
 475                 fe->is_local = f->is_local;
 476                 if (!f->is_static)
 477                         fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 478                 ++fe;
 479                 ++num;
 480         }
 481         rcu_read_unlock();
 482
 483         return num;
 484 }
 485
 486 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
 487                                                struct net_bridge_port *source,
 488                                                const unsigned char *addr,
 489                                                __u16 vid,
 490                                                unsigned char is_local,
 491                                                unsigned char is_static)
 492 {
 493         struct net_bridge_fdb_entry *fdb;
 494
 495         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 496         if (fdb) {
 497                 memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
 498                 fdb->dst = source;
 499                 fdb->key.vlan_id = vid;
 500                 fdb->is_local = is_local;
 501                 fdb->is_static = is_static;
 502                 fdb->added_by_user = 0;
 503                 fdb->added_by_external_learn = 0;
 504                 fdb->offloaded = 0;
 505                 fdb->updated = fdb->used = jiffies;
 506                 if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
 507                                                   &fdb->rhnode,
 508                                                   br_fdb_rht_params)) {
 509                         kmem_cache_free(br_fdb_cache, fdb);
 510                         fdb = NULL;
 511                 } else {
 512                         hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
 513                 }
 514         }
 515         return fdb;
 516 }
 517
 518 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 519                   const unsigned char *addr, u16 vid)
 520 {
 521         struct net_bridge_fdb_entry *fdb;
 522
 523         if (!is_valid_ether_addr(addr))
 524                 return -EINVAL;
 525
 526         fdb = br_fdb_find(br, addr, vid);
 527         if (fdb) {
 528                 /* it is okay to have multiple ports with same
 529                  * address, just use the first one.
 530                  */
 531                 if (fdb->is_local)
 532                         return 0;
 533                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 534                        source ? source->dev->name : br->dev->name, addr, vid);
 535                 fdb_delete(br, fdb, true);
 536         }
 537
 538         fdb = fdb_create(br, source, addr, vid, 1, 1);
 539         if (!fdb)
 540                 return -ENOMEM;
 541
 542         fdb_add_hw_addr(br, addr);
 543         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 544         return 0;
 545 }
 546
 547 /* Add entry for local address of interface */
 548 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 549                   const unsigned char *addr, u16 vid)
 550 {
 551         int ret;
 552
 553         spin_lock_bh(&br->hash_lock);
 554         ret = fdb_insert(br, source, addr, vid);
 555         spin_unlock_bh(&br->hash_lock);
 556         return ret;
 557 }
 558
 559 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 560                    const unsigned char *addr, u16 vid, bool added_by_user)
 561 {
 562         struct net_bridge_fdb_entry *fdb;
 563         bool fdb_modified = false;
 564
 565         /* some users want to always flood. */
 566         if (hold_time(br) == 0)
 567                 return;
 568
 569         /* ignore packets unless we are using this port */
 570         if (!(source->state == BR_STATE_LEARNING ||
 571               source->state == BR_STATE_FORWARDING))
 572                 return;
 573
 574         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 575         if (likely(fdb)) {
 576                 /* attempt to update an entry for a local interface */
 577                 if (unlikely(fdb->is_local)) {
 578                         if (net_ratelimit())
 579                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 580                                         source->dev->name, addr, vid);
 581                 } else {
 582                         unsigned long now = jiffies;
 583
 584                         /* fastpath: update of existing entry */
 585                         if (unlikely(source != fdb->dst)) {
 586                                 fdb->dst = source;
 587                                 fdb_modified = true;
 588                                 /* Take over HW learned entry */
 589                                 if (unlikely(fdb->added_by_external_learn))
 590                                         fdb->added_by_external_learn = 0;
 591                         }
 592                         if (now != fdb->updated)
 593                                 fdb->updated = now;
 594                         if (unlikely(added_by_user))
 595                                 fdb->added_by_user = 1;
 596                         if (unlikely(fdb_modified)) {
 597                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 598                                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 599                         }
 600                 }
 601         } else {
 602                 spin_lock(&br->hash_lock);
 603                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 604                 if (fdb) {
 605                         if (unlikely(added_by_user))
 606                                 fdb->added_by_user = 1;
 607                         trace_br_fdb_update(br, source, addr, vid,
 608                                             added_by_user);
 609                         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 610                 }
 611                 /* else  we lose race and someone else inserts
 612                  * it first, don't bother updating
 613                  */
 614                 spin_unlock(&br->hash_lock);
 615         }
 616 }
 617
 618 static int fdb_to_nud(const struct net_bridge *br,
 619                       const struct net_bridge_fdb_entry *fdb)
 620 {
 621         if (fdb->is_local)
 622                 return NUD_PERMANENT;
 623         else if (fdb->is_static)
 624                 return NUD_NOARP;
 625         else if (has_expired(br, fdb))
 626                 return NUD_STALE;
 627         else
 628                 return NUD_REACHABLE;
 629 }
 630
 631 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 632                          const struct net_bridge_fdb_entry *fdb,
 633                          u32 portid, u32 seq, int type, unsigned int flags)
 634 {
 635         unsigned long now = jiffies;
 636         struct nda_cacheinfo ci;
 637         struct nlmsghdr *nlh;
 638         struct ndmsg *ndm;
 639
 640         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 641         if (nlh == NULL)
 642                 return -EMSGSIZE;
 643
 644         ndm = nlmsg_data(nlh);
 645         ndm->ndm_family  = AF_BRIDGE;
 646         ndm->ndm_pad1    = 0;
 647         ndm->ndm_pad2    = 0;
 648         ndm->ndm_flags   = 0;
 649         ndm->ndm_type    = 0;
 650         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 651         ndm->ndm_state   = fdb_to_nud(br, fdb);
 652
 653         if (fdb->offloaded)
 654                 ndm->ndm_flags |= NTF_OFFLOADED;
 655         if (fdb->added_by_external_learn)
 656                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 657
 658         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 659                 goto nla_put_failure;
 660         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 661                 goto nla_put_failure;
 662         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 663         ci.ndm_confirmed = 0;
 664         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 665         ci.ndm_refcnt    = 0;
 666         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 667                 goto nla_put_failure;
 668
 669         if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 670                                         &fdb->key.vlan_id))
 671                 goto nla_put_failure;
 672
 673         nlmsg_end(skb, nlh);
 674         return 0;
 675
 676 nla_put_failure:
 677         nlmsg_cancel(skb, nlh);
 678         return -EMSGSIZE;
 679 }
 680
 681 static inline size_t fdb_nlmsg_size(void)
 682 {
 683         return NLMSG_ALIGN(sizeof(struct ndmsg))
 684                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 685                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 686                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 687                 + nla_total_size(sizeof(struct nda_cacheinfo));
 688 }
 689
 690 static void fdb_notify(struct net_bridge *br,
 691                        const struct net_bridge_fdb_entry *fdb, int type,
 692                        bool swdev_notify)
 693 {
 694         struct net *net = dev_net(br->dev);
 695         struct sk_buff *skb;
 696         int err = -ENOBUFS;
 697
 698         if (swdev_notify)
 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         struct net_bridge_fdb_entry *f;
 727         int err = 0;
 728
 729         if (!(dev->priv_flags & IFF_EBRIDGE))
 730                 return err;
 731
 732         if (!filter_dev) {
 733                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 734                 if (err < 0)
 735                         return err;
 736         }
 737
 738         rcu_read_lock();
 739         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 740                 if (*idx < cb->args[2])
 741                         goto skip;
 742                 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 743                         if (filter_dev != dev)
 744                                 goto skip;
 745                         /* !f->dst is a special case for bridge
 746                          * It means the MAC belongs to the bridge
 747                          * Therefore need a little more filtering
 748                          * we only want to dump the !f->dst case
 749                          */
 750                         if (f->dst)
 751                                 goto skip;
 752                 }
 753                 if (!filter_dev && f->dst)
 754                         goto skip;
 755
 756                 err = fdb_fill_info(skb, br, f,
 757                                     NETLINK_CB(cb->skb).portid,
 758                                     cb->nlh->nlmsg_seq,
 759                                     RTM_NEWNEIGH,
 760                                     NLM_F_MULTI);
 761                 if (err < 0)
 762                         break;
 763 skip:
 764                 *idx += 1;
 765         }
 766         rcu_read_unlock();
 767
 768         return err;
 769 }
 770
 771 /* Update (create or replace) forwarding database entry */
 772 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 773                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 774 {
 775         struct net_bridge_fdb_entry *fdb;
 776         bool modified = false;
 777
 778         /* If the port cannot learn allow only local and static entries */
 779         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 780             !(source->state == BR_STATE_LEARNING ||
 781               source->state == BR_STATE_FORWARDING))
 782                 return -EPERM;
 783
 784         if (!source && !(state & NUD_PERMANENT)) {
 785                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 786                         br->dev->name);
 787                 return -EINVAL;
 788         }
 789
 790         fdb = br_fdb_find(br, addr, vid);
 791         if (fdb == NULL) {
 792                 if (!(flags & NLM_F_CREATE))
 793                         return -ENOENT;
 794
 795                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 796                 if (!fdb)
 797                         return -ENOMEM;
 798
 799                 modified = true;
 800         } else {
 801                 if (flags & NLM_F_EXCL)
 802                         return -EEXIST;
 803
 804                 if (fdb->dst != source) {
 805                         fdb->dst = source;
 806                         modified = true;
 807                 }
 808         }
 809
 810         if (fdb_to_nud(br, fdb) != state) {
 811                 if (state & NUD_PERMANENT) {
 812                         fdb->is_local = 1;
 813                         if (!fdb->is_static) {
 814                                 fdb->is_static = 1;
 815                                 fdb_add_hw_addr(br, addr);
 816                         }
 817                 } else if (state & NUD_NOARP) {
 818                         fdb->is_local = 0;
 819                         if (!fdb->is_static) {
 820                                 fdb->is_static = 1;
 821                                 fdb_add_hw_addr(br, addr);
 822                         }
 823                 } else {
 824                         fdb->is_local = 0;
 825                         if (fdb->is_static) {
 826                                 fdb->is_static = 0;
 827                                 fdb_del_hw_addr(br, addr);
 828                         }
 829                 }
 830
 831                 modified = true;
 832         }
 833         fdb->added_by_user = 1;
 834
 835         fdb->used = jiffies;
 836         if (modified) {
 837                 fdb->updated = jiffies;
 838                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 839         }
 840
 841         return 0;
 842 }
 843
 844 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 845                         struct net_bridge_port *p, const unsigned char *addr,
 846                         u16 nlh_flags, u16 vid)
 847 {
 848         int err = 0;
 849
 850         if (ndm->ndm_flags & NTF_USE) {
 851                 if (!p) {
 852                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 853                                 br->dev->name);
 854                         return -EINVAL;
 855                 }
 856                 local_bh_disable();
 857                 rcu_read_lock();
 858                 br_fdb_update(br, p, addr, vid, true);
 859                 rcu_read_unlock();
 860                 local_bh_enable();
 861         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 862                 err = br_fdb_external_learn_add(br, p, addr, vid, true);
 863         } else {
 864                 spin_lock_bh(&br->hash_lock);
 865                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 866                                     nlh_flags, vid);
 867                 spin_unlock_bh(&br->hash_lock);
 868         }
 869
 870         return err;
 871 }
 872
 873 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 874 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 875                struct net_device *dev,
 876                const unsigned char *addr, u16 vid, u16 nlh_flags)
 877 {
 878         struct net_bridge_vlan_group *vg;
 879         struct net_bridge_port *p = NULL;
 880         struct net_bridge_vlan *v;
 881         struct net_bridge *br = NULL;
 882         int err = 0;
 883
 884         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 885
 886         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 887                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 888                 return -EINVAL;
 889         }
 890
 891         if (is_zero_ether_addr(addr)) {
 892                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 893                 return -EINVAL;
 894         }
 895
 896         if (dev->priv_flags & IFF_EBRIDGE) {
 897                 br = netdev_priv(dev);
 898                 vg = br_vlan_group(br);
 899         } else {
 900                 p = br_port_get_rtnl(dev);
 901                 if (!p) {
 902                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 903                                 dev->name);
 904                         return -EINVAL;
 905                 }
 906                 br = p->br;
 907                 vg = nbp_vlan_group(p);
 908         }
 909
 910         if (vid) {
 911                 v = br_vlan_find(vg, vid);
 912                 if (!v || !br_vlan_should_use(v)) {
 913                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 914                         return -EINVAL;
 915                 }
 916
 917                 /* VID was specified, so use it. */
 918                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 919         } else {
 920                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 921                 if (err || !vg || !vg->num_vlans)
 922                         goto out;
 923
 924                 /* We have vlans configured on this port and user didn't
 925                  * specify a VLAN.  To be nice, add/update entry for every
 926                  * vlan on this port.
 927                  */
 928                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 929                         if (!br_vlan_should_use(v))
 930                                 continue;
 931                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 932                         if (err)
 933                                 goto out;
 934                 }
 935         }
 936
 937 out:
 938         return err;
 939 }
 940
 941 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 942                                        const struct net_bridge_port *p,
 943                                        const u8 *addr, u16 vlan)
 944 {
 945         struct net_bridge_fdb_entry *fdb;
 946
 947         fdb = br_fdb_find(br, addr, vlan);
 948         if (!fdb || fdb->dst != p)
 949                 return -ENOENT;
 950
 951         fdb_delete(br, fdb, true);
 952
 953         return 0;
 954 }
 955
 956 static int __br_fdb_delete(struct net_bridge *br,
 957                            const struct net_bridge_port *p,
 958                            const unsigned char *addr, u16 vid)
 959 {
 960         int err;
 961
 962         spin_lock_bh(&br->hash_lock);
 963         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 964         spin_unlock_bh(&br->hash_lock);
 965
 966         return err;
 967 }
 968
 969 /* Remove neighbor entry with RTM_DELNEIGH */
 970 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 971                   struct net_device *dev,
 972                   const unsigned char *addr, u16 vid)
 973 {
 974         struct net_bridge_vlan_group *vg;
 975         struct net_bridge_port *p = NULL;
 976         struct net_bridge_vlan *v;
 977         struct net_bridge *br;
 978         int err;
 979
 980         if (dev->priv_flags & IFF_EBRIDGE) {
 981                 br = netdev_priv(dev);
 982                 vg = br_vlan_group(br);
 983         } else {
 984                 p = br_port_get_rtnl(dev);
 985                 if (!p) {
 986                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 987                                 dev->name);
 988                         return -EINVAL;
 989                 }
 990                 vg = nbp_vlan_group(p);
 991                 br = p->br;
 992         }
 993
 994         if (vid) {
 995                 v = br_vlan_find(vg, vid);
 996                 if (!v) {
 997                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 998                         return -EINVAL;
 999                 }
1000
1001                 err = __br_fdb_delete(br, p, addr, vid);
1002         } else {
1003                 err = -ENOENT;
1004                 err &= __br_fdb_delete(br, p, addr, 0);
1005                 if (!vg || !vg->num_vlans)
1006                         return err;
1007
1008                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1009                         if (!br_vlan_should_use(v))
1010                                 continue;
1011                         err &= __br_fdb_delete(br, p, addr, v->vid);
1012                 }
1013         }
1014
1015         return err;
1016 }
1017
1018 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1019 {
1020         struct net_bridge_fdb_entry *f, *tmp;
1021         int err = 0;
1022
1023         ASSERT_RTNL();
1024
1025         /* the key here is that static entries change only under rtnl */
1026         rcu_read_lock();
1027         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1028                 /* We only care for static entries */
1029                 if (!f->is_static)
1030                         continue;
1031                 err = dev_uc_add(p->dev, f->key.addr.addr);
1032                 if (err)
1033                         goto rollback;
1034         }
1035 done:
1036         rcu_read_unlock();
1037
1038         return err;
1039
1040 rollback:
1041         hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1042                 /* We only care for static entries */
1043                 if (!tmp->is_static)
1044                         continue;
1045                 if (tmp == f)
1046                         break;
1047                 dev_uc_del(p->dev, tmp->key.addr.addr);
1048         }
1049
1050         goto done;
1051 }
1052
1053 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1054 {
1055         struct net_bridge_fdb_entry *f;
1056
1057         ASSERT_RTNL();
1058
1059         rcu_read_lock();
1060         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1061                 /* We only care for static entries */
1062                 if (!f->is_static)
1063                         continue;
1064
1065                 dev_uc_del(p->dev, f->key.addr.addr);
1066         }
1067         rcu_read_unlock();
1068 }
1069
1070 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1071                               const unsigned char *addr, u16 vid,
1072                               bool swdev_notify)
1073 {
1074         struct net_bridge_fdb_entry *fdb;
1075         bool modified = false;
1076         int err = 0;
1077
1078         trace_br_fdb_external_learn_add(br, p, addr, vid);
1079
1080         spin_lock_bh(&br->hash_lock);
1081
1082         fdb = br_fdb_find(br, addr, vid);
1083         if (!fdb) {
1084                 fdb = fdb_create(br, p, addr, vid, 0, 0);
1085                 if (!fdb) {
1086                         err = -ENOMEM;
1087                         goto err_unlock;
1088                 }
1089                 fdb->added_by_external_learn = 1;
1090                 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1091         } else {
1092                 fdb->updated = jiffies;
1093
1094                 if (fdb->dst != p) {
1095                         fdb->dst = p;
1096                         modified = true;
1097                 }
1098
1099                 if (fdb->added_by_external_learn) {
1100                         /* Refresh entry */
1101                         fdb->used = jiffies;
1102                 } else if (!fdb->added_by_user) {
1103                         /* Take over SW learned entry */
1104                         fdb->added_by_external_learn = 1;
1105                         modified = true;
1106                 }
1107
1108                 if (modified)
1109                         fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1110         }
1111
1112 err_unlock:
1113         spin_unlock_bh(&br->hash_lock);
1114
1115         return err;
1116 }
1117
1118 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1119                               const unsigned char *addr, u16 vid,
1120                               bool swdev_notify)
1121 {
1122         struct net_bridge_fdb_entry *fdb;
1123         int err = 0;
1124
1125         spin_lock_bh(&br->hash_lock);
1126
1127         fdb = br_fdb_find(br, addr, vid);
1128         if (fdb && fdb->added_by_external_learn)
1129                 fdb_delete(br, fdb, swdev_notify);
1130         else
1131                 err = -ENOENT;
1132
1133         spin_unlock_bh(&br->hash_lock);
1134
1135         return err;
1136 }
1137
1138 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1139                           const unsigned char *addr, u16 vid)
1140 {
1141         struct net_bridge_fdb_entry *fdb;
1142
1143         spin_lock_bh(&br->hash_lock);
1144
1145         fdb = br_fdb_find(br, addr, vid);
1146         if (fdb)
1147                 fdb->offloaded = 1;
1148
1149         spin_unlock_bh(&br->hash_lock);
1150 }