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 "br_private.h"
  27
  28 static struct kmem_cache *br_fdb_cache __read_mostly;
  29 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  30                       const unsigned char *addr);
  31 static void fdb_notify(struct net_bridge *br,
  32                        const struct net_bridge_fdb_entry *, int);
  33
  34 static u32 fdb_salt __read_mostly;
  35
  36 int __init br_fdb_init(void)
  37 {
  38         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  39                                          sizeof(struct net_bridge_fdb_entry),
  40                                          0,
  41                                          SLAB_HWCACHE_ALIGN, NULL);
  42         if (!br_fdb_cache)
  43                 return -ENOMEM;
  44
  45         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  46         return 0;
  47 }
  48
  49 void br_fdb_fini(void)
  50 {
  51         kmem_cache_destroy(br_fdb_cache);
  52 }
  53
  54
  55 /* if topology_changing then use forward_delay (default 15 sec)
  56  * otherwise keep longer (default 5 minutes)
  57  */
  58 static inline unsigned long hold_time(const struct net_bridge *br)
  59 {
  60         return br->topology_change ? br->forward_delay : br->ageing_time;
  61 }
  62
  63 static inline int has_expired(const struct net_bridge *br,
  64                                   const struct net_bridge_fdb_entry *fdb)
  65 {
  66         return !fdb->is_static &&
  67                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  68 }
  69
  70 static inline int br_mac_hash(const unsigned char *mac)
  71 {
  72         /* use 1 byte of OUI cnd 3 bytes of NIC */
  73         u32 key = get_unaligned((u32 *)(mac + 2));
  74         return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
  75 }
  76
  77 static void fdb_rcu_free(struct rcu_head *head)
  78 {
  79         struct net_bridge_fdb_entry *ent
  80                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  81         kmem_cache_free(br_fdb_cache, ent);
  82 }
  83
  84 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
  85 {
  86         hlist_del_rcu(&f->hlist);
  87         fdb_notify(br, f, RTM_DELNEIGH);
  88         call_rcu(&f->rcu, fdb_rcu_free);
  89 }
  90
  91 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
  92 {
  93         struct net_bridge *br = p->br;
  94         int i;
  95
  96         spin_lock_bh(&br->hash_lock);
  97
  98         /* Search all chains since old address/hash is unknown */
  99         for (i = 0; i < BR_HASH_SIZE; i++) {
 100                 struct hlist_node *h;
 101                 hlist_for_each(h, &br->hash[i]) {
 102                         struct net_bridge_fdb_entry *f;
 103
 104                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 105                         if (f->dst == p && f->is_local) {
 106                                 /* maybe another port has same hw addr? */
 107                                 struct net_bridge_port *op;
 108                                 list_for_each_entry(op, &br->port_list, list) {
 109                                         if (op != p &&
 110                                             !compare_ether_addr(op->dev->dev_addr,
 111                                                                 f->addr.addr)) {
 112                                                 f->dst = op;
 113                                                 goto insert;
 114                                         }
 115                                 }
 116
 117                                 /* delete old one */
 118                                 fdb_delete(br, f);
 119                                 goto insert;
 120                         }
 121                 }
 122         }
 123  insert:
 124         /* insert new address,  may fail if invalid address or dup. */
 125         fdb_insert(br, p, newaddr);
 126
 127         spin_unlock_bh(&br->hash_lock);
 128 }
 129
 130 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 131 {
 132         struct net_bridge_fdb_entry *f;
 133
 134         /* If old entry was unassociated with any port, then delete it. */
 135         f = __br_fdb_get(br, br->dev->dev_addr);
 136         if (f && f->is_local && !f->dst)
 137                 fdb_delete(br, f);
 138
 139         fdb_insert(br, NULL, newaddr);
 140 }
 141
 142 void br_fdb_cleanup(unsigned long _data)
 143 {
 144         struct net_bridge *br = (struct net_bridge *)_data;
 145         unsigned long delay = hold_time(br);
 146         unsigned long next_timer = jiffies + br->ageing_time;
 147         int i;
 148
 149         spin_lock(&br->hash_lock);
 150         for (i = 0; i < BR_HASH_SIZE; i++) {
 151                 struct net_bridge_fdb_entry *f;
 152                 struct hlist_node *h, *n;
 153
 154                 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
 155                         unsigned long this_timer;
 156                         if (f->is_static)
 157                                 continue;
 158                         this_timer = f->updated + delay;
 159                         if (time_before_eq(this_timer, jiffies))
 160                                 fdb_delete(br, f);
 161                         else if (time_before(this_timer, next_timer))
 162                                 next_timer = this_timer;
 163                 }
 164         }
 165         spin_unlock(&br->hash_lock);
 166
 167         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 168 }
 169
 170 /* Completely flush all dynamic entries in forwarding database.*/
 171 void br_fdb_flush(struct net_bridge *br)
 172 {
 173         int i;
 174
 175         spin_lock_bh(&br->hash_lock);
 176         for (i = 0; i < BR_HASH_SIZE; i++) {
 177                 struct net_bridge_fdb_entry *f;
 178                 struct hlist_node *h, *n;
 179                 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
 180                         if (!f->is_static)
 181                                 fdb_delete(br, f);
 182                 }
 183         }
 184         spin_unlock_bh(&br->hash_lock);
 185 }
 186
 187 /* Flush all entries referring to a specific port.
 188  * if do_all is set also flush static entries
 189  */
 190 void br_fdb_delete_by_port(struct net_bridge *br,
 191                            const struct net_bridge_port *p,
 192                            int do_all)
 193 {
 194         int i;
 195
 196         spin_lock_bh(&br->hash_lock);
 197         for (i = 0; i < BR_HASH_SIZE; i++) {
 198                 struct hlist_node *h, *g;
 199
 200                 hlist_for_each_safe(h, g, &br->hash[i]) {
 201                         struct net_bridge_fdb_entry *f
 202                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 203                         if (f->dst != p)
 204                                 continue;
 205
 206                         if (f->is_static && !do_all)
 207                                 continue;
 208                         /*
 209                          * if multiple ports all have the same device address
 210                          * then when one port is deleted, assign
 211                          * the local entry to other port
 212                          */
 213                         if (f->is_local) {
 214                                 struct net_bridge_port *op;
 215                                 list_for_each_entry(op, &br->port_list, list) {
 216                                         if (op != p &&
 217                                             !compare_ether_addr(op->dev->dev_addr,
 218                                                                 f->addr.addr)) {
 219                                                 f->dst = op;
 220                                                 goto skip_delete;
 221                                         }
 222                                 }
 223                         }
 224
 225                         fdb_delete(br, f);
 226                 skip_delete: ;
 227                 }
 228         }
 229         spin_unlock_bh(&br->hash_lock);
 230 }
 231
 232 /* No locking or refcounting, assumes caller has rcu_read_lock */
 233 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 234                                           const unsigned char *addr)
 235 {
 236         struct hlist_node *h;
 237         struct net_bridge_fdb_entry *fdb;
 238
 239         hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
 240                 if (!compare_ether_addr(fdb->addr.addr, addr)) {
 241                         if (unlikely(has_expired(br, fdb)))
 242                                 break;
 243                         return fdb;
 244                 }
 245         }
 246
 247         return NULL;
 248 }
 249
 250 #if IS_ENABLED(CONFIG_ATM_LANE)
 251 /* Interface used by ATM LANE hook to test
 252  * if an addr is on some other bridge port */
 253 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 254 {
 255         struct net_bridge_fdb_entry *fdb;
 256         struct net_bridge_port *port;
 257         int ret;
 258
 259         rcu_read_lock();
 260         port = br_port_get_rcu(dev);
 261         if (!port)
 262                 ret = 0;
 263         else {
 264                 fdb = __br_fdb_get(port->br, addr);
 265                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 266                         fdb->dst->state == BR_STATE_FORWARDING;
 267         }
 268         rcu_read_unlock();
 269
 270         return ret;
 271 }
 272 #endif /* CONFIG_ATM_LANE */
 273
 274 /*
 275  * Fill buffer with forwarding table records in
 276  * the API format.
 277  */
 278 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 279                    unsigned long maxnum, unsigned long skip)
 280 {
 281         struct __fdb_entry *fe = buf;
 282         int i, num = 0;
 283         struct hlist_node *h;
 284         struct net_bridge_fdb_entry *f;
 285
 286         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 287
 288         rcu_read_lock();
 289         for (i = 0; i < BR_HASH_SIZE; i++) {
 290                 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
 291                         if (num >= maxnum)
 292                                 goto out;
 293
 294                         if (has_expired(br, f))
 295                                 continue;
 296
 297                         /* ignore pseudo entry for local MAC address */
 298                         if (!f->dst)
 299                                 continue;
 300
 301                         if (skip) {
 302                                 --skip;
 303                                 continue;
 304                         }
 305
 306                         /* convert from internal format to API */
 307                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 308
 309                         /* due to ABI compat need to split into hi/lo */
 310                         fe->port_no = f->dst->port_no;
 311                         fe->port_hi = f->dst->port_no >> 8;
 312
 313                         fe->is_local = f->is_local;
 314                         if (!f->is_static)
 315                                 fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->updated);
 316                         ++fe;
 317                         ++num;
 318                 }
 319         }
 320
 321  out:
 322         rcu_read_unlock();
 323
 324         return num;
 325 }
 326
 327 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 328                                              const unsigned char *addr)
 329 {
 330         struct hlist_node *h;
 331         struct net_bridge_fdb_entry *fdb;
 332
 333         hlist_for_each_entry(fdb, h, head, hlist) {
 334                 if (!compare_ether_addr(fdb->addr.addr, addr))
 335                         return fdb;
 336         }
 337         return NULL;
 338 }
 339
 340 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 341                                                  const unsigned char *addr)
 342 {
 343         struct hlist_node *h;
 344         struct net_bridge_fdb_entry *fdb;
 345
 346         hlist_for_each_entry_rcu(fdb, h, head, hlist) {
 347                 if (!compare_ether_addr(fdb->addr.addr, addr))
 348                         return fdb;
 349         }
 350         return NULL;
 351 }
 352
 353 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 354                                                struct net_bridge_port *source,
 355                                                const unsigned char *addr)
 356 {
 357         struct net_bridge_fdb_entry *fdb;
 358
 359         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 360         if (fdb) {
 361                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 362                 fdb->dst = source;
 363                 fdb->is_local = 0;
 364                 fdb->is_static = 0;
 365                 fdb->updated = fdb->used = jiffies;
 366                 hlist_add_head_rcu(&fdb->hlist, head);
 367         }
 368         return fdb;
 369 }
 370
 371 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 372                   const unsigned char *addr)
 373 {
 374         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
 375         struct net_bridge_fdb_entry *fdb;
 376
 377         if (!is_valid_ether_addr(addr))
 378                 return -EINVAL;
 379
 380         fdb = fdb_find(head, addr);
 381         if (fdb) {
 382                 /* it is okay to have multiple ports with same
 383                  * address, just use the first one.
 384                  */
 385                 if (fdb->is_local)
 386                         return 0;
 387                 br_warn(br, "adding interface %s with same address "
 388                        "as a received packet\n",
 389                        source->dev->name);
 390                 fdb_delete(br, fdb);
 391         }
 392
 393         fdb = fdb_create(head, source, addr);
 394         if (!fdb)
 395                 return -ENOMEM;
 396
 397         fdb->is_local = fdb->is_static = 1;
 398         fdb_notify(br, fdb, RTM_NEWNEIGH);
 399         return 0;
 400 }
 401
 402 /* Add entry for local address of interface */
 403 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 404                   const unsigned char *addr)
 405 {
 406         int ret;
 407
 408         spin_lock_bh(&br->hash_lock);
 409         ret = fdb_insert(br, source, addr);
 410         spin_unlock_bh(&br->hash_lock);
 411         return ret;
 412 }
 413
 414 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 415                    const unsigned char *addr)
 416 {
 417         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
 418         struct net_bridge_fdb_entry *fdb;
 419
 420         /* some users want to always flood. */
 421         if (hold_time(br) == 0)
 422                 return;
 423
 424         /* ignore packets unless we are using this port */
 425         if (!(source->state == BR_STATE_LEARNING ||
 426               source->state == BR_STATE_FORWARDING))
 427                 return;
 428
 429         fdb = fdb_find_rcu(head, addr);
 430         if (likely(fdb)) {
 431                 /* attempt to update an entry for a local interface */
 432                 if (unlikely(fdb->is_local)) {
 433                         if (net_ratelimit())
 434                                 br_warn(br, "received packet on %s with "
 435                                         "own address as source address\n",
 436                                         source->dev->name);
 437                 } else {
 438                         /* fastpath: update of existing entry */
 439                         fdb->dst = source;
 440                         fdb->updated = jiffies;
 441                 }
 442         } else {
 443                 spin_lock(&br->hash_lock);
 444                 if (likely(!fdb_find(head, addr))) {
 445                         fdb = fdb_create(head, source, addr);
 446                         if (fdb)
 447                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 448                 }
 449                 /* else  we lose race and someone else inserts
 450                  * it first, don't bother updating
 451                  */
 452                 spin_unlock(&br->hash_lock);
 453         }
 454 }
 455
 456 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
 457 {
 458         if (fdb->is_local)
 459                 return NUD_PERMANENT;
 460         else if (fdb->is_static)
 461                 return NUD_NOARP;
 462         else if (has_expired(fdb->dst->br, fdb))
 463                 return NUD_STALE;
 464         else
 465                 return NUD_REACHABLE;
 466 }
 467
 468 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 469                          const struct net_bridge_fdb_entry *fdb,
 470                          u32 pid, u32 seq, int type, unsigned int flags)
 471 {
 472         unsigned long now = jiffies;
 473         struct nda_cacheinfo ci;
 474         struct nlmsghdr *nlh;
 475         struct ndmsg *ndm;
 476
 477         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
 478         if (nlh == NULL)
 479                 return -EMSGSIZE;
 480
 481         ndm = nlmsg_data(nlh);
 482         ndm->ndm_family  = AF_BRIDGE;
 483         ndm->ndm_pad1    = 0;
 484         ndm->ndm_pad2    = 0;
 485         ndm->ndm_flags   = 0;
 486         ndm->ndm_type    = 0;
 487         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 488         ndm->ndm_state   = fdb_to_nud(fdb);
 489
 490         NLA_PUT(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr);
 491
 492         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 493         ci.ndm_confirmed = 0;
 494         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 495         ci.ndm_refcnt    = 0;
 496         NLA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);
 497
 498         return nlmsg_end(skb, nlh);
 499
 500 nla_put_failure:
 501         nlmsg_cancel(skb, nlh);
 502         return -EMSGSIZE;
 503 }
 504
 505 static inline size_t fdb_nlmsg_size(void)
 506 {
 507         return NLMSG_ALIGN(sizeof(struct ndmsg))
 508                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 509                 + nla_total_size(sizeof(struct nda_cacheinfo));
 510 }
 511
 512 static void fdb_notify(struct net_bridge *br,
 513                        const struct net_bridge_fdb_entry *fdb, int type)
 514 {
 515         struct net *net = dev_net(br->dev);
 516         struct sk_buff *skb;
 517         int err = -ENOBUFS;
 518
 519         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 520         if (skb == NULL)
 521                 goto errout;
 522
 523         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 524         if (err < 0) {
 525                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 526                 WARN_ON(err == -EMSGSIZE);
 527                 kfree_skb(skb);
 528                 goto errout;
 529         }
 530         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 531         return;
 532 errout:
 533         if (err < 0)
 534                 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 535 }
 536
 537 /* Dump information about entries, in response to GETNEIGH */
 538 int br_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 539 {
 540         struct net *net = sock_net(skb->sk);
 541         struct net_device *dev;
 542         int idx = 0;
 543
 544         rcu_read_lock();
 545         for_each_netdev_rcu(net, dev) {
 546                 struct net_bridge *br = netdev_priv(dev);
 547                 int i;
 548
 549                 if (!(dev->priv_flags & IFF_EBRIDGE))
 550                         continue;
 551
 552                 for (i = 0; i < BR_HASH_SIZE; i++) {
 553                         struct hlist_node *h;
 554                         struct net_bridge_fdb_entry *f;
 555
 556                         hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
 557                                 if (idx < cb->args[0])
 558                                         goto skip;
 559
 560                                 if (fdb_fill_info(skb, br, f,
 561                                                   NETLINK_CB(cb->skb).pid,
 562                                                   cb->nlh->nlmsg_seq,
 563                                                   RTM_NEWNEIGH,
 564                                                   NLM_F_MULTI) < 0)
 565                                         break;
 566 skip:
 567                                 ++idx;
 568                         }
 569                 }
 570         }
 571         rcu_read_unlock();
 572
 573         cb->args[0] = idx;
 574
 575         return skb->len;
 576 }
 577
 578 /* Update (create or replace) forwarding database entry */
 579 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 580                          __u16 state, __u16 flags)
 581 {
 582         struct net_bridge *br = source->br;
 583         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
 584         struct net_bridge_fdb_entry *fdb;
 585
 586         fdb = fdb_find(head, addr);
 587         if (fdb == NULL) {
 588                 if (!(flags & NLM_F_CREATE))
 589                         return -ENOENT;
 590
 591                 fdb = fdb_create(head, source, addr);
 592                 if (!fdb)
 593                         return -ENOMEM;
 594                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 595         } else {
 596                 if (flags & NLM_F_EXCL)
 597                         return -EEXIST;
 598         }
 599
 600         if (fdb_to_nud(fdb) != state) {
 601                 if (state & NUD_PERMANENT)
 602                         fdb->is_local = fdb->is_static = 1;
 603                 else if (state & NUD_NOARP) {
 604                         fdb->is_local = 0;
 605                         fdb->is_static = 1;
 606                 } else
 607                         fdb->is_local = fdb->is_static = 0;
 608
 609                 fdb->updated = fdb->used = jiffies;
 610                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 611         }
 612
 613         return 0;
 614 }
 615
 616 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 617 int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 618 {
 619         struct net *net = sock_net(skb->sk);
 620         struct ndmsg *ndm;
 621         struct nlattr *tb[NDA_MAX+1];
 622         struct net_device *dev;
 623         struct net_bridge_port *p;
 624         const __u8 *addr;
 625         int err;
 626
 627         ASSERT_RTNL();
 628         err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
 629         if (err < 0)
 630                 return err;
 631
 632         ndm = nlmsg_data(nlh);
 633         if (ndm->ndm_ifindex == 0) {
 634                 pr_info("bridge: RTM_NEWNEIGH with invalid ifindex\n");
 635                 return -EINVAL;
 636         }
 637
 638         dev = __dev_get_by_index(net, ndm->ndm_ifindex);
 639         if (dev == NULL) {
 640                 pr_info("bridge: RTM_NEWNEIGH with unknown ifindex\n");
 641                 return -ENODEV;
 642         }
 643
 644         if (!tb[NDA_LLADDR] || nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {
 645                 pr_info("bridge: RTM_NEWNEIGH with invalid address\n");
 646                 return -EINVAL;
 647         }
 648
 649         addr = nla_data(tb[NDA_LLADDR]);
 650         if (!is_valid_ether_addr(addr)) {
 651                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 652                 return -EINVAL;
 653         }
 654
 655         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 656                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 657                 return -EINVAL;
 658         }
 659
 660         p = br_port_get_rtnl(dev);
 661         if (p == NULL) {
 662                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 663                         dev->name);
 664                 return -EINVAL;
 665         }
 666
 667         if (ndm->ndm_flags & NTF_USE) {
 668                 rcu_read_lock();
 669                 br_fdb_update(p->br, p, addr);
 670                 rcu_read_unlock();
 671         } else {
 672                 spin_lock_bh(&p->br->hash_lock);
 673                 err = fdb_add_entry(p, addr, ndm->ndm_state, nlh->nlmsg_flags);
 674                 spin_unlock_bh(&p->br->hash_lock);
 675         }
 676
 677         return err;
 678 }
 679
 680 static int fdb_delete_by_addr(struct net_bridge_port *p, const u8 *addr)
 681 {
 682         struct net_bridge *br = p->br;
 683         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
 684         struct net_bridge_fdb_entry *fdb;
 685
 686         fdb = fdb_find(head, addr);
 687         if (!fdb)
 688                 return -ENOENT;
 689
 690         fdb_delete(p->br, fdb);
 691         return 0;
 692 }
 693
 694 /* Remove neighbor entry with RTM_DELNEIGH */
 695 int br_fdb_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 696 {
 697         struct net *net = sock_net(skb->sk);
 698         struct ndmsg *ndm;
 699         struct net_bridge_port *p;
 700         struct nlattr *llattr;
 701         const __u8 *addr;
 702         struct net_device *dev;
 703         int err;
 704
 705         ASSERT_RTNL();
 706         if (nlmsg_len(nlh) < sizeof(*ndm))
 707                 return -EINVAL;
 708
 709         ndm = nlmsg_data(nlh);
 710         if (ndm->ndm_ifindex == 0) {
 711                 pr_info("bridge: RTM_DELNEIGH with invalid ifindex\n");
 712                 return -EINVAL;
 713         }
 714
 715         dev = __dev_get_by_index(net, ndm->ndm_ifindex);
 716         if (dev == NULL) {
 717                 pr_info("bridge: RTM_DELNEIGH with unknown ifindex\n");
 718                 return -ENODEV;
 719         }
 720
 721         llattr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_LLADDR);
 722         if (llattr == NULL || nla_len(llattr) != ETH_ALEN) {
 723                 pr_info("bridge: RTM_DELNEIGH with invalid address\n");
 724                 return -EINVAL;
 725         }
 726
 727         addr = nla_data(llattr);
 728
 729         p = br_port_get_rtnl(dev);
 730         if (p == NULL) {
 731                 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 732                         dev->name);
 733                 return -EINVAL;
 734         }
 735
 736         spin_lock_bh(&p->br->hash_lock);
 737         err = fdb_delete_by_addr(p, addr);
 738         spin_unlock_bh(&p->br->hash_lock);
 739
 740         return err;
 741 }