net/bridge/br_fdb.c

   1 /*
   2  *      Forwarding database
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/rculist.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/times.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/jhash.h>
  22 #include <linux/random.h>
  23 #include <linux/slab.h>
  24 #include <linux/atomic.h>
  25 #include <asm/unaligned.h>
  26 #include <linux/if_vlan.h>
  27 #include <net/switchdev.h>
  28 #include "br_private.h"
  29
  30 static struct kmem_cache *br_fdb_cache __read_mostly;
  31 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  32                                              const unsigned char *addr,
  33                                              __u16 vid);
  34 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  35                       const unsigned char *addr, u16 vid);
  36 static void fdb_notify(struct net_bridge *br,
  37                        const struct net_bridge_fdb_entry *, int);
  38
  39 static u32 fdb_salt __read_mostly;
  40
  41 int __init br_fdb_init(void)
  42 {
  43         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  44                                          sizeof(struct net_bridge_fdb_entry),
  45                                          0,
  46                                          SLAB_HWCACHE_ALIGN, NULL);
  47         if (!br_fdb_cache)
  48                 return -ENOMEM;
  49
  50         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  51         return 0;
  52 }
  53
  54 void br_fdb_fini(void)
  55 {
  56         kmem_cache_destroy(br_fdb_cache);
  57 }
  58
  59
  60 /* if topology_changing then use forward_delay (default 15 sec)
  61  * otherwise keep longer (default 5 minutes)
  62  */
  63 static inline unsigned long hold_time(const struct net_bridge *br)
  64 {
  65         return br->topology_change ? br->forward_delay : br->ageing_time;
  66 }
  67
  68 static inline int has_expired(const struct net_bridge *br,
  69                                   const struct net_bridge_fdb_entry *fdb)
  70 {
  71         return !fdb->is_static &&
  72                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  73 }
  74
  75 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  76 {
  77         /* use 1 byte of OUI and 3 bytes of NIC */
  78         u32 key = get_unaligned((u32 *)(mac + 2));
  79         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  80 }
  81
  82 static void fdb_rcu_free(struct rcu_head *head)
  83 {
  84         struct net_bridge_fdb_entry *ent
  85                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  86         kmem_cache_free(br_fdb_cache, ent);
  87 }
  88
  89 /* When a static FDB entry is added, the mac address from the entry is
  90  * added to the bridge private HW address list and all required ports
  91  * are then updated with the new information.
  92  * Called under RTNL.
  93  */
  94 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
  95 {
  96         int err;
  97         struct net_bridge_port *p;
  98
  99         ASSERT_RTNL();
 100
 101         list_for_each_entry(p, &br->port_list, list) {
 102                 if (!br_promisc_port(p)) {
 103                         err = dev_uc_add(p->dev, addr);
 104                         if (err)
 105                                 goto undo;
 106                 }
 107         }
 108
 109         return;
 110 undo:
 111         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 112                 if (!br_promisc_port(p))
 113                         dev_uc_del(p->dev, addr);
 114         }
 115 }
 116
 117 /* When a static FDB entry is deleted, the HW address from that entry is
 118  * also removed from the bridge private HW address list and updates all
 119  * the ports with needed information.
 120  * Called under RTNL.
 121  */
 122 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 123 {
 124         struct net_bridge_port *p;
 125
 126         ASSERT_RTNL();
 127
 128         list_for_each_entry(p, &br->port_list, list) {
 129                 if (!br_promisc_port(p))
 130                         dev_uc_del(p->dev, addr);
 131         }
 132 }
 133
 134 static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 135 {
 136         struct switchdev_obj_port_fdb fdb = {
 137                 .obj = {
 138                         .orig_dev = f->dst->dev,
 139                         .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 140                         .flags = SWITCHDEV_F_DEFER,
 141                 },
 142                 .vid = f->vlan_id,
 143         };
 144
 145         ether_addr_copy(fdb.addr, f->addr.addr);
 146         switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 147 }
 148
 149 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 150 {
 151         if (f->is_static)
 152                 fdb_del_hw_addr(br, f->addr.addr);
 153
 154         if (f->added_by_external_learn)
 155                 fdb_del_external_learn(f);
 156
 157         hlist_del_rcu(&f->hlist);
 158         fdb_notify(br, f, RTM_DELNEIGH);
 159         call_rcu(&f->rcu, fdb_rcu_free);
 160 }
 161
 162 /* Delete a local entry if no other port had the same address. */
 163 static void fdb_delete_local(struct net_bridge *br,
 164                              const struct net_bridge_port *p,
 165                              struct net_bridge_fdb_entry *f)
 166 {
 167         const unsigned char *addr = f->addr.addr;
 168         struct net_bridge_vlan_group *vg;
 169         const struct net_bridge_vlan *v;
 170         struct net_bridge_port *op;
 171         u16 vid = f->vlan_id;
 172
 173         /* Maybe another port has same hw addr? */
 174         list_for_each_entry(op, &br->port_list, list) {
 175                 vg = nbp_vlan_group(op);
 176                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 177                     (!vid || br_vlan_find(vg, vid))) {
 178                         f->dst = op;
 179                         f->added_by_user = 0;
 180                         return;
 181                 }
 182         }
 183
 184         vg = br_vlan_group(br);
 185         v = br_vlan_find(vg, vid);
 186         /* Maybe bridge device has same hw addr? */
 187         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 188             (!vid || (v && br_vlan_should_use(v)))) {
 189                 f->dst = NULL;
 190                 f->added_by_user = 0;
 191                 return;
 192         }
 193
 194         fdb_delete(br, f);
 195 }
 196
 197 void br_fdb_find_delete_local(struct net_bridge *br,
 198                               const struct net_bridge_port *p,
 199                               const unsigned char *addr, u16 vid)
 200 {
 201         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 202         struct net_bridge_fdb_entry *f;
 203
 204         spin_lock_bh(&br->hash_lock);
 205         f = fdb_find(head, addr, vid);
 206         if (f && f->is_local && !f->added_by_user && f->dst == p)
 207                 fdb_delete_local(br, p, f);
 208         spin_unlock_bh(&br->hash_lock);
 209 }
 210
 211 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 212 {
 213         struct net_bridge_vlan_group *vg;
 214         struct net_bridge *br = p->br;
 215         struct net_bridge_vlan *v;
 216         int i;
 217
 218         spin_lock_bh(&br->hash_lock);
 219
 220         vg = nbp_vlan_group(p);
 221         /* Search all chains since old address/hash is unknown */
 222         for (i = 0; i < BR_HASH_SIZE; i++) {
 223                 struct hlist_node *h;
 224                 hlist_for_each(h, &br->hash[i]) {
 225                         struct net_bridge_fdb_entry *f;
 226
 227                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 228                         if (f->dst == p && f->is_local && !f->added_by_user) {
 229                                 /* delete old one */
 230                                 fdb_delete_local(br, p, f);
 231
 232                                 /* if this port has no vlan information
 233                                  * configured, we can safely be done at
 234                                  * this point.
 235                                  */
 236                                 if (!vg || !vg->num_vlans)
 237                                         goto insert;
 238                         }
 239                 }
 240         }
 241
 242 insert:
 243         /* insert new address,  may fail if invalid address or dup. */
 244         fdb_insert(br, p, newaddr, 0);
 245
 246         if (!vg || !vg->num_vlans)
 247                 goto done;
 248
 249         /* Now add entries for every VLAN configured on the port.
 250          * This function runs under RTNL so the bitmap will not change
 251          * from under us.
 252          */
 253         list_for_each_entry(v, &vg->vlan_list, vlist)
 254                 fdb_insert(br, p, newaddr, v->vid);
 255
 256 done:
 257         spin_unlock_bh(&br->hash_lock);
 258 }
 259
 260 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 261 {
 262         struct net_bridge_vlan_group *vg;
 263         struct net_bridge_fdb_entry *f;
 264         struct net_bridge_vlan *v;
 265
 266         spin_lock_bh(&br->hash_lock);
 267
 268         /* If old entry was unassociated with any port, then delete it. */
 269         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 270         if (f && f->is_local && !f->dst && !f->added_by_user)
 271                 fdb_delete_local(br, NULL, f);
 272
 273         fdb_insert(br, NULL, newaddr, 0);
 274         vg = br_vlan_group(br);
 275         if (!vg || !vg->num_vlans)
 276                 goto out;
 277         /* Now remove and add entries for every VLAN configured on the
 278          * bridge.  This function runs under RTNL so the bitmap will not
 279          * change from under us.
 280          */
 281         list_for_each_entry(v, &vg->vlan_list, vlist) {
 282                 if (!br_vlan_should_use(v))
 283                         continue;
 284                 f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 285                 if (f && f->is_local && !f->dst && !f->added_by_user)
 286                         fdb_delete_local(br, NULL, f);
 287                 fdb_insert(br, NULL, newaddr, v->vid);
 288         }
 289 out:
 290         spin_unlock_bh(&br->hash_lock);
 291 }
 292
 293 void br_fdb_cleanup(unsigned long _data)
 294 {
 295         struct net_bridge *br = (struct net_bridge *)_data;
 296         unsigned long delay = hold_time(br);
 297         unsigned long next_timer = jiffies + br->ageing_time;
 298         int i;
 299
 300         spin_lock(&br->hash_lock);
 301         for (i = 0; i < BR_HASH_SIZE; i++) {
 302                 struct net_bridge_fdb_entry *f;
 303                 struct hlist_node *n;
 304
 305                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 306                         unsigned long this_timer;
 307                         if (f->is_static)
 308                                 continue;
 309                         if (f->added_by_external_learn)
 310                                 continue;
 311                         this_timer = f->updated + delay;
 312                         if (time_before_eq(this_timer, jiffies))
 313                                 fdb_delete(br, f);
 314                         else if (time_before(this_timer, next_timer))
 315                                 next_timer = this_timer;
 316                 }
 317         }
 318         spin_unlock(&br->hash_lock);
 319
 320         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 321 }
 322
 323 /* Completely flush all dynamic entries in forwarding database.*/
 324 void br_fdb_flush(struct net_bridge *br)
 325 {
 326         int i;
 327
 328         spin_lock_bh(&br->hash_lock);
 329         for (i = 0; i < BR_HASH_SIZE; i++) {
 330                 struct net_bridge_fdb_entry *f;
 331                 struct hlist_node *n;
 332                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 333                         if (!f->is_static)
 334                                 fdb_delete(br, f);
 335                 }
 336         }
 337         spin_unlock_bh(&br->hash_lock);
 338 }
 339
 340 /* Flush all entries referring to a specific port.
 341  * if do_all is set also flush static entries
 342  * if vid is set delete all entries that match the vlan_id
 343  */
 344 void br_fdb_delete_by_port(struct net_bridge *br,
 345                            const struct net_bridge_port *p,
 346                            u16 vid,
 347                            int do_all)
 348 {
 349         int i;
 350
 351         spin_lock_bh(&br->hash_lock);
 352         for (i = 0; i < BR_HASH_SIZE; i++) {
 353                 struct hlist_node *h, *g;
 354
 355                 hlist_for_each_safe(h, g, &br->hash[i]) {
 356                         struct net_bridge_fdb_entry *f
 357                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 358                         if (f->dst != p)
 359                                 continue;
 360
 361                         if (!do_all)
 362                                 if (f->is_static || (vid && f->vlan_id != vid))
 363                                         continue;
 364
 365                         if (f->is_local)
 366                                 fdb_delete_local(br, p, f);
 367                         else
 368                                 fdb_delete(br, f);
 369                 }
 370         }
 371         spin_unlock_bh(&br->hash_lock);
 372 }
 373
 374 /* No locking or refcounting, assumes caller has rcu_read_lock */
 375 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 376                                           const unsigned char *addr,
 377                                           __u16 vid)
 378 {
 379         struct net_bridge_fdb_entry *fdb;
 380
 381         hlist_for_each_entry_rcu(fdb,
 382                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 383                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 384                     fdb->vlan_id == vid) {
 385                         if (unlikely(has_expired(br, fdb)))
 386                                 break;
 387                         return fdb;
 388                 }
 389         }
 390
 391         return NULL;
 392 }
 393
 394 #if IS_ENABLED(CONFIG_ATM_LANE)
 395 /* Interface used by ATM LANE hook to test
 396  * if an addr is on some other bridge port */
 397 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 398 {
 399         struct net_bridge_fdb_entry *fdb;
 400         struct net_bridge_port *port;
 401         int ret;
 402
 403         rcu_read_lock();
 404         port = br_port_get_rcu(dev);
 405         if (!port)
 406                 ret = 0;
 407         else {
 408                 fdb = __br_fdb_get(port->br, addr, 0);
 409                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 410                         fdb->dst->state == BR_STATE_FORWARDING;
 411         }
 412         rcu_read_unlock();
 413
 414         return ret;
 415 }
 416 #endif /* CONFIG_ATM_LANE */
 417
 418 /*
 419  * Fill buffer with forwarding table records in
 420  * the API format.
 421  */
 422 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 423                    unsigned long maxnum, unsigned long skip)
 424 {
 425         struct __fdb_entry *fe = buf;
 426         int i, num = 0;
 427         struct net_bridge_fdb_entry *f;
 428
 429         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 430
 431         rcu_read_lock();
 432         for (i = 0; i < BR_HASH_SIZE; i++) {
 433                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 434                         if (num >= maxnum)
 435                                 goto out;
 436
 437                         if (has_expired(br, f))
 438                                 continue;
 439
 440                         /* ignore pseudo entry for local MAC address */
 441                         if (!f->dst)
 442                                 continue;
 443
 444                         if (skip) {
 445                                 --skip;
 446                                 continue;
 447                         }
 448
 449                         /* convert from internal format to API */
 450                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 451
 452                         /* due to ABI compat need to split into hi/lo */
 453                         fe->port_no = f->dst->port_no;
 454                         fe->port_hi = f->dst->port_no >> 8;
 455
 456                         fe->is_local = f->is_local;
 457                         if (!f->is_static)
 458                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 459                         ++fe;
 460                         ++num;
 461                 }
 462         }
 463
 464  out:
 465         rcu_read_unlock();
 466
 467         return num;
 468 }
 469
 470 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 471                                              const unsigned char *addr,
 472                                              __u16 vid)
 473 {
 474         struct net_bridge_fdb_entry *fdb;
 475
 476         hlist_for_each_entry(fdb, head, hlist) {
 477                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 478                     fdb->vlan_id == vid)
 479                         return fdb;
 480         }
 481         return NULL;
 482 }
 483
 484 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 485                                                  const unsigned char *addr,
 486                                                  __u16 vid)
 487 {
 488         struct net_bridge_fdb_entry *fdb;
 489
 490         hlist_for_each_entry_rcu(fdb, head, hlist) {
 491                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 492                     fdb->vlan_id == vid)
 493                         return fdb;
 494         }
 495         return NULL;
 496 }
 497
 498 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 499                                                struct net_bridge_port *source,
 500                                                const unsigned char *addr,
 501                                                __u16 vid,
 502                                                unsigned char is_local,
 503                                                unsigned char is_static)
 504 {
 505         struct net_bridge_fdb_entry *fdb;
 506
 507         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 508         if (fdb) {
 509                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 510                 fdb->dst = source;
 511                 fdb->vlan_id = vid;
 512                 fdb->is_local = is_local;
 513                 fdb->is_static = is_static;
 514                 fdb->added_by_user = 0;
 515                 fdb->added_by_external_learn = 0;
 516                 fdb->updated = fdb->used = jiffies;
 517                 hlist_add_head_rcu(&fdb->hlist, head);
 518         }
 519         return fdb;
 520 }
 521
 522 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 523                   const unsigned char *addr, u16 vid)
 524 {
 525         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 526         struct net_bridge_fdb_entry *fdb;
 527
 528         if (!is_valid_ether_addr(addr))
 529                 return -EINVAL;
 530
 531         fdb = fdb_find(head, addr, vid);
 532         if (fdb) {
 533                 /* it is okay to have multiple ports with same
 534                  * address, just use the first one.
 535                  */
 536                 if (fdb->is_local)
 537                         return 0;
 538                 br_warn(br, "adding interface %s with same address "
 539                        "as a received packet\n",
 540                        source ? source->dev->name : br->dev->name);
 541                 fdb_delete(br, fdb);
 542         }
 543
 544         fdb = fdb_create(head, source, addr, vid, 1, 1);
 545         if (!fdb)
 546                 return -ENOMEM;
 547
 548         fdb_add_hw_addr(br, addr);
 549         fdb_notify(br, fdb, RTM_NEWNEIGH);
 550         return 0;
 551 }
 552
 553 /* Add entry for local address of interface */
 554 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 555                   const unsigned char *addr, u16 vid)
 556 {
 557         int ret;
 558
 559         spin_lock_bh(&br->hash_lock);
 560         ret = fdb_insert(br, source, addr, vid);
 561         spin_unlock_bh(&br->hash_lock);
 562         return ret;
 563 }
 564
 565 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 566                    const unsigned char *addr, u16 vid, bool added_by_user)
 567 {
 568         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 569         struct net_bridge_fdb_entry *fdb;
 570         bool fdb_modified = false;
 571
 572         /* some users want to always flood. */
 573         if (hold_time(br) == 0)
 574                 return;
 575
 576         /* ignore packets unless we are using this port */
 577         if (!(source->state == BR_STATE_LEARNING ||
 578               source->state == BR_STATE_FORWARDING))
 579                 return;
 580
 581         fdb = fdb_find_rcu(head, addr, vid);
 582         if (likely(fdb)) {
 583                 /* attempt to update an entry for a local interface */
 584                 if (unlikely(fdb->is_local)) {
 585                         if (net_ratelimit())
 586                                 br_warn(br, "received packet on %s with "
 587                                         "own address as source address\n",
 588                                         source->dev->name);
 589                 } else {
 590                         /* fastpath: update of existing entry */
 591                         if (unlikely(source != fdb->dst)) {
 592                                 fdb->dst = source;
 593                                 fdb_modified = true;
 594                         }
 595                         fdb->updated = jiffies;
 596                         if (unlikely(added_by_user))
 597                                 fdb->added_by_user = 1;
 598                         if (unlikely(fdb_modified))
 599                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 600                 }
 601         } else {
 602                 spin_lock(&br->hash_lock);
 603                 if (likely(!fdb_find(head, addr, vid))) {
 604                         fdb = fdb_create(head, source, addr, vid, 0, 0);
 605                         if (fdb) {
 606                                 if (unlikely(added_by_user))
 607                                         fdb->added_by_user = 1;
 608                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 609                         }
 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   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 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 (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 654                 goto nla_put_failure;
 655         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 656                 goto nla_put_failure;
 657         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 658         ci.ndm_confirmed = 0;
 659         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 660         ci.ndm_refcnt    = 0;
 661         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 662                 goto nla_put_failure;
 663
 664         if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 665                 goto nla_put_failure;
 666
 667         nlmsg_end(skb, nlh);
 668         return 0;
 669
 670 nla_put_failure:
 671         nlmsg_cancel(skb, nlh);
 672         return -EMSGSIZE;
 673 }
 674
 675 static inline size_t fdb_nlmsg_size(void)
 676 {
 677         return NLMSG_ALIGN(sizeof(struct ndmsg))
 678                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 679                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 680                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 681                 + nla_total_size(sizeof(struct nda_cacheinfo));
 682 }
 683
 684 static void fdb_notify(struct net_bridge *br,
 685                        const struct net_bridge_fdb_entry *fdb, int type)
 686 {
 687         struct net *net = dev_net(br->dev);
 688         struct sk_buff *skb;
 689         int err = -ENOBUFS;
 690
 691         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 692         if (skb == NULL)
 693                 goto errout;
 694
 695         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 696         if (err < 0) {
 697                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 698                 WARN_ON(err == -EMSGSIZE);
 699                 kfree_skb(skb);
 700                 goto errout;
 701         }
 702         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 703         return;
 704 errout:
 705         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 706 }
 707
 708 /* Dump information about entries, in response to GETNEIGH */
 709 int br_fdb_dump(struct sk_buff *skb,
 710                 struct netlink_callback *cb,
 711                 struct net_device *dev,
 712                 struct net_device *filter_dev,
 713                 int *idx)
 714 {
 715         struct net_bridge *br = netdev_priv(dev);
 716         int err = 0;
 717         int i;
 718
 719         if (!(dev->priv_flags & IFF_EBRIDGE))
 720                 goto out;
 721
 722         if (!filter_dev) {
 723                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 724                 if (err < 0)
 725                         goto out;
 726         }
 727
 728         for (i = 0; i < BR_HASH_SIZE; i++) {
 729                 struct net_bridge_fdb_entry *f;
 730
 731                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 732
 733                         if (*idx < cb->args[2])
 734                                 goto skip;
 735
 736                         if (filter_dev &&
 737                             (!f->dst || f->dst->dev != filter_dev)) {
 738                                 if (filter_dev != dev)
 739                                         goto skip;
 740                                 /* !f->dst is a special case for bridge
 741                                  * It means the MAC belongs to the bridge
 742                                  * Therefore need a little more filtering
 743                                  * we only want to dump the !f->dst case
 744                                  */
 745                                 if (f->dst)
 746                                         goto skip;
 747                         }
 748                         if (!filter_dev && f->dst)
 749                                 goto skip;
 750
 751                         err = fdb_fill_info(skb, br, f,
 752                                             NETLINK_CB(cb->skb).portid,
 753                                             cb->nlh->nlmsg_seq,
 754                                             RTM_NEWNEIGH,
 755                                             NLM_F_MULTI);
 756                         if (err < 0)
 757                                 goto out;
 758 skip:
 759                         *idx += 1;
 760                 }
 761         }
 762
 763 out:
 764         return err;
 765 }
 766
 767 /* Update (create or replace) forwarding database entry */
 768 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 769                          const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 770 {
 771         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 772         struct net_bridge_fdb_entry *fdb;
 773         bool modified = false;
 774
 775         /* If the port cannot learn allow only local and static entries */
 776         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 777             !(source->state == BR_STATE_LEARNING ||
 778               source->state == BR_STATE_FORWARDING))
 779                 return -EPERM;
 780
 781         if (!source && !(state & NUD_PERMANENT)) {
 782                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 783                         br->dev->name);
 784                 return -EINVAL;
 785         }
 786
 787         fdb = fdb_find(head, addr, vid);
 788         if (fdb == NULL) {
 789                 if (!(flags & NLM_F_CREATE))
 790                         return -ENOENT;
 791
 792                 fdb = fdb_create(head, source, addr, vid, 0, 0);
 793                 if (!fdb)
 794                         return -ENOMEM;
 795
 796                 modified = true;
 797         } else {
 798                 if (flags & NLM_F_EXCL)
 799                         return -EEXIST;
 800
 801                 if (fdb->dst != source) {
 802                         fdb->dst = source;
 803                         modified = true;
 804                 }
 805         }
 806
 807         if (fdb_to_nud(br, fdb) != state) {
 808                 if (state & NUD_PERMANENT) {
 809                         fdb->is_local = 1;
 810                         if (!fdb->is_static) {
 811                                 fdb->is_static = 1;
 812                                 fdb_add_hw_addr(br, addr);
 813                         }
 814                 } else if (state & NUD_NOARP) {
 815                         fdb->is_local = 0;
 816                         if (!fdb->is_static) {
 817                                 fdb->is_static = 1;
 818                                 fdb_add_hw_addr(br, addr);
 819                         }
 820                 } else {
 821                         fdb->is_local = 0;
 822                         if (fdb->is_static) {
 823                                 fdb->is_static = 0;
 824                                 fdb_del_hw_addr(br, addr);
 825                         }
 826                 }
 827
 828                 modified = true;
 829         }
 830         fdb->added_by_user = 1;
 831
 832         fdb->used = jiffies;
 833         if (modified) {
 834                 fdb->updated = jiffies;
 835                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 836         }
 837
 838         return 0;
 839 }
 840
 841 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 842                         struct net_bridge_port *p, const unsigned char *addr,
 843                         u16 nlh_flags, u16 vid)
 844 {
 845         int err = 0;
 846
 847         if (ndm->ndm_flags & NTF_USE) {
 848                 if (!p) {
 849                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 850                                 br->dev->name);
 851                         return -EINVAL;
 852                 }
 853                 local_bh_disable();
 854                 rcu_read_lock();
 855                 br_fdb_update(br, p, addr, vid, true);
 856                 rcu_read_unlock();
 857                 local_bh_enable();
 858         } else {
 859                 spin_lock_bh(&br->hash_lock);
 860                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 861                                     nlh_flags, vid);
 862                 spin_unlock_bh(&br->hash_lock);
 863         }
 864
 865         return err;
 866 }
 867
 868 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 869 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 870                struct net_device *dev,
 871                const unsigned char *addr, u16 vid, u16 nlh_flags)
 872 {
 873         struct net_bridge_vlan_group *vg;
 874         struct net_bridge_port *p = NULL;
 875         struct net_bridge_vlan *v;
 876         struct net_bridge *br = NULL;
 877         int err = 0;
 878
 879         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 880                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 881                 return -EINVAL;
 882         }
 883
 884         if (is_zero_ether_addr(addr)) {
 885                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 886                 return -EINVAL;
 887         }
 888
 889         if (dev->priv_flags & IFF_EBRIDGE) {
 890                 br = netdev_priv(dev);
 891                 vg = br_vlan_group(br);
 892         } else {
 893                 p = br_port_get_rtnl(dev);
 894                 if (!p) {
 895                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 896                                 dev->name);
 897                         return -EINVAL;
 898                 }
 899                 br = p->br;
 900                 vg = nbp_vlan_group(p);
 901         }
 902
 903         if (vid) {
 904                 v = br_vlan_find(vg, vid);
 905                 if (!v || !br_vlan_should_use(v)) {
 906                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 907                         return -EINVAL;
 908                 }
 909
 910                 /* VID was specified, so use it. */
 911                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 912         } else {
 913                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 914                 if (err || !vg || !vg->num_vlans)
 915                         goto out;
 916
 917                 /* We have vlans configured on this port and user didn't
 918                  * specify a VLAN.  To be nice, add/update entry for every
 919                  * vlan on this port.
 920                  */
 921                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 922                         if (!br_vlan_should_use(v))
 923                                 continue;
 924                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 925                         if (err)
 926                                 goto out;
 927                 }
 928         }
 929
 930 out:
 931         return err;
 932 }
 933
 934 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 935                               u16 vid)
 936 {
 937         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 938         struct net_bridge_fdb_entry *fdb;
 939
 940         fdb = fdb_find(head, addr, vid);
 941         if (!fdb)
 942                 return -ENOENT;
 943
 944         fdb_delete(br, fdb);
 945         return 0;
 946 }
 947
 948 static int __br_fdb_delete_by_addr(struct net_bridge *br,
 949                                    const unsigned char *addr, u16 vid)
 950 {
 951         int err;
 952
 953         spin_lock_bh(&br->hash_lock);
 954         err = fdb_delete_by_addr(br, addr, vid);
 955         spin_unlock_bh(&br->hash_lock);
 956
 957         return err;
 958 }
 959
 960 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 961                                        const u8 *addr, u16 vlan)
 962 {
 963         struct net_bridge *br = p->br;
 964         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 965         struct net_bridge_fdb_entry *fdb;
 966
 967         fdb = fdb_find(head, addr, vlan);
 968         if (!fdb || fdb->dst != p)
 969                 return -ENOENT;
 970
 971         fdb_delete(br, fdb);
 972         return 0;
 973 }
 974
 975 static int __br_fdb_delete(struct net_bridge_port *p,
 976                            const unsigned char *addr, u16 vid)
 977 {
 978         int err;
 979
 980         spin_lock_bh(&p->br->hash_lock);
 981         err = fdb_delete_by_addr_and_port(p, addr, vid);
 982         spin_unlock_bh(&p->br->hash_lock);
 983
 984         return err;
 985 }
 986
 987 /* Remove neighbor entry with RTM_DELNEIGH */
 988 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 989                   struct net_device *dev,
 990                   const unsigned char *addr, u16 vid)
 991 {
 992         struct net_bridge_vlan_group *vg;
 993         struct net_bridge_port *p = NULL;
 994         struct net_bridge_vlan *v;
 995         struct net_bridge *br = NULL;
 996         int err;
 997
 998         if (dev->priv_flags & IFF_EBRIDGE) {
 999                 br = netdev_priv(dev);
1000                 vg = br_vlan_group(br);
1001         } else {
1002                 p = br_port_get_rtnl(dev);
1003                 if (!p) {
1004                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1005                                 dev->name);
1006                         return -EINVAL;
1007                 }
1008                 vg = nbp_vlan_group(p);
1009         }
1010
1011         if (vid) {
1012                 v = br_vlan_find(vg, vid);
1013                 if (!v) {
1014                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1015                         return -EINVAL;
1016                 }
1017
1018                 if (dev->priv_flags & IFF_EBRIDGE)
1019                         err = __br_fdb_delete_by_addr(br, addr, vid);
1020                 else
1021                         err = __br_fdb_delete(p, addr, vid);
1022         } else {
1023                 err = -ENOENT;
1024                 if (dev->priv_flags & IFF_EBRIDGE)
1025                         err = __br_fdb_delete_by_addr(br, addr, 0);
1026                 else
1027                         err &= __br_fdb_delete(p, addr, 0);
1028
1029                 if (!vg || !vg->num_vlans)
1030                         goto out;
1031
1032                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1033                         if (!br_vlan_should_use(v))
1034                                 continue;
1035                         if (dev->priv_flags & IFF_EBRIDGE)
1036                                 err = __br_fdb_delete_by_addr(br, addr, v->vid);
1037                         else
1038                                 err &= __br_fdb_delete(p, addr, v->vid);
1039                 }
1040         }
1041 out:
1042         return err;
1043 }
1044
1045 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1046 {
1047         struct net_bridge_fdb_entry *fdb, *tmp;
1048         int i;
1049         int err;
1050
1051         ASSERT_RTNL();
1052
1053         for (i = 0; i < BR_HASH_SIZE; i++) {
1054                 hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1055                         /* We only care for static entries */
1056                         if (!fdb->is_static)
1057                                 continue;
1058
1059                         err = dev_uc_add(p->dev, fdb->addr.addr);
1060                         if (err)
1061                                 goto rollback;
1062                 }
1063         }
1064         return 0;
1065
1066 rollback:
1067         for (i = 0; i < BR_HASH_SIZE; i++) {
1068                 hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1069                         /* If we reached the fdb that failed, we can stop */
1070                         if (tmp == fdb)
1071                                 break;
1072
1073                         /* We only care for static entries */
1074                         if (!tmp->is_static)
1075                                 continue;
1076
1077                         dev_uc_del(p->dev, tmp->addr.addr);
1078                 }
1079         }
1080         return err;
1081 }
1082
1083 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1084 {
1085         struct net_bridge_fdb_entry *fdb;
1086         int i;
1087
1088         ASSERT_RTNL();
1089
1090         for (i = 0; i < BR_HASH_SIZE; i++) {
1091                 hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1092                         /* We only care for static entries */
1093                         if (!fdb->is_static)
1094                                 continue;
1095
1096                         dev_uc_del(p->dev, fdb->addr.addr);
1097                 }
1098         }
1099 }
1100
1101 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1102                               const unsigned char *addr, u16 vid)
1103 {
1104         struct hlist_head *head;
1105         struct net_bridge_fdb_entry *fdb;
1106         int err = 0;
1107
1108         ASSERT_RTNL();
1109         spin_lock_bh(&br->hash_lock);
1110
1111         head = &br->hash[br_mac_hash(addr, vid)];
1112         fdb = fdb_find(head, addr, vid);
1113         if (!fdb) {
1114                 fdb = fdb_create(head, p, addr, vid, 0, 0);
1115                 if (!fdb) {
1116                         err = -ENOMEM;
1117                         goto err_unlock;
1118                 }
1119                 fdb->added_by_external_learn = 1;
1120                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1121         } else if (fdb->added_by_external_learn) {
1122                 /* Refresh entry */
1123                 fdb->updated = fdb->used = jiffies;
1124         } else if (!fdb->added_by_user) {
1125                 /* Take over SW learned entry */
1126                 fdb->added_by_external_learn = 1;
1127                 fdb->updated = jiffies;
1128                 fdb_notify(br, fdb, RTM_NEWNEIGH);
1129         }
1130
1131 err_unlock:
1132         spin_unlock_bh(&br->hash_lock);
1133
1134         return err;
1135 }
1136
1137 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1138                               const unsigned char *addr, u16 vid)
1139 {
1140         struct hlist_head *head;
1141         struct net_bridge_fdb_entry *fdb;
1142         int err = 0;
1143
1144         ASSERT_RTNL();
1145         spin_lock_bh(&br->hash_lock);
1146
1147         head = &br->hash[br_mac_hash(addr, vid)];
1148         fdb = fdb_find(head, addr, vid);
1149         if (fdb && fdb->added_by_external_learn)
1150                 fdb_delete(br, fdb);
1151         else
1152                 err = -ENOENT;
1153
1154         spin_unlock_bh(&br->hash_lock);
1155
1156         return err;
1157 }