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