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 "br_private.h"
  28
  29 static struct kmem_cache *br_fdb_cache __read_mostly;
  30 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  31                                              const unsigned char *addr,
  32                                              __u16 vid);
  33 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  34                       const unsigned char *addr, u16 vid);
  35 static void fdb_notify(struct net_bridge *br,
  36                        const struct net_bridge_fdb_entry *, int);
  37
  38 static u32 fdb_salt __read_mostly;
  39
  40 int __init br_fdb_init(void)
  41 {
  42         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  43                                          sizeof(struct net_bridge_fdb_entry),
  44                                          0,
  45                                          SLAB_HWCACHE_ALIGN, NULL);
  46         if (!br_fdb_cache)
  47                 return -ENOMEM;
  48
  49         get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  50         return 0;
  51 }
  52
  53 void br_fdb_fini(void)
  54 {
  55         kmem_cache_destroy(br_fdb_cache);
  56 }
  57
  58
  59 /* if topology_changing then use forward_delay (default 15 sec)
  60  * otherwise keep longer (default 5 minutes)
  61  */
  62 static inline unsigned long hold_time(const struct net_bridge *br)
  63 {
  64         return br->topology_change ? br->forward_delay : br->ageing_time;
  65 }
  66
  67 static inline int has_expired(const struct net_bridge *br,
  68                                   const struct net_bridge_fdb_entry *fdb)
  69 {
  70         return !fdb->is_static &&
  71                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  72 }
  73
  74 static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  75 {
  76         /* use 1 byte of OUI and 3 bytes of NIC */
  77         u32 key = get_unaligned((u32 *)(mac + 2));
  78         return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  79 }
  80
  81 static void fdb_rcu_free(struct rcu_head *head)
  82 {
  83         struct net_bridge_fdb_entry *ent
  84                 = container_of(head, struct net_bridge_fdb_entry, rcu);
  85         kmem_cache_free(br_fdb_cache, ent);
  86 }
  87
  88 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
  89 {
  90         hlist_del_rcu(&f->hlist);
  91         fdb_notify(br, f, RTM_DELNEIGH);
  92         call_rcu(&f->rcu, fdb_rcu_free);
  93 }
  94
  95 /* Delete a local entry if no other port had the same address. */
  96 static void fdb_delete_local(struct net_bridge *br,
  97                              const struct net_bridge_port *p,
  98                              struct net_bridge_fdb_entry *f)
  99 {
 100         const unsigned char *addr = f->addr.addr;
 101         u16 vid = f->vlan_id;
 102         struct net_bridge_port *op;
 103
 104         /* Maybe another port has same hw addr? */
 105         list_for_each_entry(op, &br->port_list, list) {
 106                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 107                     (!vid || nbp_vlan_find(op, vid))) {
 108                         f->dst = op;
 109                         f->added_by_user = 0;
 110                         return;
 111                 }
 112         }
 113
 114         /* Maybe bridge device has same hw addr? */
 115         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 116             (!vid || br_vlan_find(br, vid))) {
 117                 f->dst = NULL;
 118                 f->added_by_user = 0;
 119                 return;
 120         }
 121
 122         fdb_delete(br, f);
 123 }
 124
 125 void br_fdb_find_delete_local(struct net_bridge *br,
 126                               const struct net_bridge_port *p,
 127                               const unsigned char *addr, u16 vid)
 128 {
 129         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 130         struct net_bridge_fdb_entry *f;
 131
 132         spin_lock_bh(&br->hash_lock);
 133         f = fdb_find(head, addr, vid);
 134         if (f && f->is_local && !f->added_by_user && f->dst == p)
 135                 fdb_delete_local(br, p, f);
 136         spin_unlock_bh(&br->hash_lock);
 137 }
 138
 139 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 140 {
 141         struct net_bridge *br = p->br;
 142         struct net_port_vlans *pv = nbp_get_vlan_info(p);
 143         bool no_vlan = !pv;
 144         int i;
 145         u16 vid;
 146
 147         spin_lock_bh(&br->hash_lock);
 148
 149         /* Search all chains since old address/hash is unknown */
 150         for (i = 0; i < BR_HASH_SIZE; i++) {
 151                 struct hlist_node *h;
 152                 hlist_for_each(h, &br->hash[i]) {
 153                         struct net_bridge_fdb_entry *f;
 154
 155                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 156                         if (f->dst == p && f->is_local && !f->added_by_user) {
 157                                 /* delete old one */
 158                                 fdb_delete_local(br, p, f);
 159
 160                                 /* if this port has no vlan information
 161                                  * configured, we can safely be done at
 162                                  * this point.
 163                                  */
 164                                 if (no_vlan)
 165                                         goto insert;
 166                         }
 167                 }
 168         }
 169
 170 insert:
 171         /* insert new address,  may fail if invalid address or dup. */
 172         fdb_insert(br, p, newaddr, 0);
 173
 174         if (no_vlan)
 175                 goto done;
 176
 177         /* Now add entries for every VLAN configured on the port.
 178          * This function runs under RTNL so the bitmap will not change
 179          * from under us.
 180          */
 181         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 182                 fdb_insert(br, p, newaddr, vid);
 183
 184 done:
 185         spin_unlock_bh(&br->hash_lock);
 186 }
 187
 188 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 189 {
 190         struct net_bridge_fdb_entry *f;
 191         struct net_port_vlans *pv;
 192         u16 vid = 0;
 193
 194         spin_lock_bh(&br->hash_lock);
 195
 196         /* If old entry was unassociated with any port, then delete it. */
 197         f = __br_fdb_get(br, br->dev->dev_addr, 0);
 198         if (f && f->is_local && !f->dst)
 199                 fdb_delete_local(br, NULL, f);
 200
 201         fdb_insert(br, NULL, newaddr, 0);
 202
 203         /* Now remove and add entries for every VLAN configured on the
 204          * bridge.  This function runs under RTNL so the bitmap will not
 205          * change from under us.
 206          */
 207         pv = br_get_vlan_info(br);
 208         if (!pv)
 209                 goto out;
 210
 211         for_each_set_bit_from(vid, pv->vlan_bitmap, VLAN_N_VID) {
 212                 f = __br_fdb_get(br, br->dev->dev_addr, vid);
 213                 if (f && f->is_local && !f->dst)
 214                         fdb_delete_local(br, NULL, f);
 215                 fdb_insert(br, NULL, newaddr, vid);
 216         }
 217 out:
 218         spin_unlock_bh(&br->hash_lock);
 219 }
 220
 221 void br_fdb_cleanup(unsigned long _data)
 222 {
 223         struct net_bridge *br = (struct net_bridge *)_data;
 224         unsigned long delay = hold_time(br);
 225         unsigned long next_timer = jiffies + br->ageing_time;
 226         int i;
 227
 228         spin_lock(&br->hash_lock);
 229         for (i = 0; i < BR_HASH_SIZE; i++) {
 230                 struct net_bridge_fdb_entry *f;
 231                 struct hlist_node *n;
 232
 233                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 234                         unsigned long this_timer;
 235                         if (f->is_static)
 236                                 continue;
 237                         this_timer = f->updated + delay;
 238                         if (time_before_eq(this_timer, jiffies))
 239                                 fdb_delete(br, f);
 240                         else if (time_before(this_timer, next_timer))
 241                                 next_timer = this_timer;
 242                 }
 243         }
 244         spin_unlock(&br->hash_lock);
 245
 246         mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 247 }
 248
 249 /* Completely flush all dynamic entries in forwarding database.*/
 250 void br_fdb_flush(struct net_bridge *br)
 251 {
 252         int i;
 253
 254         spin_lock_bh(&br->hash_lock);
 255         for (i = 0; i < BR_HASH_SIZE; i++) {
 256                 struct net_bridge_fdb_entry *f;
 257                 struct hlist_node *n;
 258                 hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 259                         if (!f->is_static)
 260                                 fdb_delete(br, f);
 261                 }
 262         }
 263         spin_unlock_bh(&br->hash_lock);
 264 }
 265
 266 /* Flush all entries referring to a specific port.
 267  * if do_all is set also flush static entries
 268  */
 269 void br_fdb_delete_by_port(struct net_bridge *br,
 270                            const struct net_bridge_port *p,
 271                            int do_all)
 272 {
 273         int i;
 274
 275         spin_lock_bh(&br->hash_lock);
 276         for (i = 0; i < BR_HASH_SIZE; i++) {
 277                 struct hlist_node *h, *g;
 278
 279                 hlist_for_each_safe(h, g, &br->hash[i]) {
 280                         struct net_bridge_fdb_entry *f
 281                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 282                         if (f->dst != p)
 283                                 continue;
 284
 285                         if (f->is_static && !do_all)
 286                                 continue;
 287
 288                         if (f->is_local)
 289                                 fdb_delete_local(br, p, f);
 290                         else
 291                                 fdb_delete(br, f);
 292                 }
 293         }
 294         spin_unlock_bh(&br->hash_lock);
 295 }
 296
 297 /* No locking or refcounting, assumes caller has rcu_read_lock */
 298 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 299                                           const unsigned char *addr,
 300                                           __u16 vid)
 301 {
 302         struct net_bridge_fdb_entry *fdb;
 303
 304         hlist_for_each_entry_rcu(fdb,
 305                                 &br->hash[br_mac_hash(addr, vid)], hlist) {
 306                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 307                     fdb->vlan_id == vid) {
 308                         if (unlikely(has_expired(br, fdb)))
 309                                 break;
 310                         return fdb;
 311                 }
 312         }
 313
 314         return NULL;
 315 }
 316
 317 #if IS_ENABLED(CONFIG_ATM_LANE)
 318 /* Interface used by ATM LANE hook to test
 319  * if an addr is on some other bridge port */
 320 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 321 {
 322         struct net_bridge_fdb_entry *fdb;
 323         struct net_bridge_port *port;
 324         int ret;
 325
 326         rcu_read_lock();
 327         port = br_port_get_rcu(dev);
 328         if (!port)
 329                 ret = 0;
 330         else {
 331                 fdb = __br_fdb_get(port->br, addr, 0);
 332                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 333                         fdb->dst->state == BR_STATE_FORWARDING;
 334         }
 335         rcu_read_unlock();
 336
 337         return ret;
 338 }
 339 #endif /* CONFIG_ATM_LANE */
 340
 341 /*
 342  * Fill buffer with forwarding table records in
 343  * the API format.
 344  */
 345 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 346                    unsigned long maxnum, unsigned long skip)
 347 {
 348         struct __fdb_entry *fe = buf;
 349         int i, num = 0;
 350         struct net_bridge_fdb_entry *f;
 351
 352         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 353
 354         rcu_read_lock();
 355         for (i = 0; i < BR_HASH_SIZE; i++) {
 356                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 357                         if (num >= maxnum)
 358                                 goto out;
 359
 360                         if (has_expired(br, f))
 361                                 continue;
 362
 363                         /* ignore pseudo entry for local MAC address */
 364                         if (!f->dst)
 365                                 continue;
 366
 367                         if (skip) {
 368                                 --skip;
 369                                 continue;
 370                         }
 371
 372                         /* convert from internal format to API */
 373                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 374
 375                         /* due to ABI compat need to split into hi/lo */
 376                         fe->port_no = f->dst->port_no;
 377                         fe->port_hi = f->dst->port_no >> 8;
 378
 379                         fe->is_local = f->is_local;
 380                         if (!f->is_static)
 381                                 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 382                         ++fe;
 383                         ++num;
 384                 }
 385         }
 386
 387  out:
 388         rcu_read_unlock();
 389
 390         return num;
 391 }
 392
 393 static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 394                                              const unsigned char *addr,
 395                                              __u16 vid)
 396 {
 397         struct net_bridge_fdb_entry *fdb;
 398
 399         hlist_for_each_entry(fdb, head, hlist) {
 400                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 401                     fdb->vlan_id == vid)
 402                         return fdb;
 403         }
 404         return NULL;
 405 }
 406
 407 static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 408                                                  const unsigned char *addr,
 409                                                  __u16 vid)
 410 {
 411         struct net_bridge_fdb_entry *fdb;
 412
 413         hlist_for_each_entry_rcu(fdb, head, hlist) {
 414                 if (ether_addr_equal(fdb->addr.addr, addr) &&
 415                     fdb->vlan_id == vid)
 416                         return fdb;
 417         }
 418         return NULL;
 419 }
 420
 421 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 422                                                struct net_bridge_port *source,
 423                                                const unsigned char *addr,
 424                                                __u16 vid)
 425 {
 426         struct net_bridge_fdb_entry *fdb;
 427
 428         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 429         if (fdb) {
 430                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
 431                 fdb->dst = source;
 432                 fdb->vlan_id = vid;
 433                 fdb->is_local = 0;
 434                 fdb->is_static = 0;
 435                 fdb->added_by_user = 0;
 436                 fdb->updated = fdb->used = jiffies;
 437                 hlist_add_head_rcu(&fdb->hlist, head);
 438         }
 439         return fdb;
 440 }
 441
 442 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 443                   const unsigned char *addr, u16 vid)
 444 {
 445         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 446         struct net_bridge_fdb_entry *fdb;
 447
 448         if (!is_valid_ether_addr(addr))
 449                 return -EINVAL;
 450
 451         fdb = fdb_find(head, addr, vid);
 452         if (fdb) {
 453                 /* it is okay to have multiple ports with same
 454                  * address, just use the first one.
 455                  */
 456                 if (fdb->is_local)
 457                         return 0;
 458                 br_warn(br, "adding interface %s with same address "
 459                        "as a received packet\n",
 460                        source ? source->dev->name : br->dev->name);
 461                 fdb_delete(br, fdb);
 462         }
 463
 464         fdb = fdb_create(head, source, addr, vid);
 465         if (!fdb)
 466                 return -ENOMEM;
 467
 468         fdb->is_local = fdb->is_static = 1;
 469         fdb_notify(br, fdb, RTM_NEWNEIGH);
 470         return 0;
 471 }
 472
 473 /* Add entry for local address of interface */
 474 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 475                   const unsigned char *addr, u16 vid)
 476 {
 477         int ret;
 478
 479         spin_lock_bh(&br->hash_lock);
 480         ret = fdb_insert(br, source, addr, vid);
 481         spin_unlock_bh(&br->hash_lock);
 482         return ret;
 483 }
 484
 485 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 486                    const unsigned char *addr, u16 vid, bool added_by_user)
 487 {
 488         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 489         struct net_bridge_fdb_entry *fdb;
 490         bool fdb_modified = false;
 491
 492         /* some users want to always flood. */
 493         if (hold_time(br) == 0)
 494                 return;
 495
 496         /* ignore packets unless we are using this port */
 497         if (!(source->state == BR_STATE_LEARNING ||
 498               source->state == BR_STATE_FORWARDING))
 499                 return;
 500
 501         fdb = fdb_find_rcu(head, addr, vid);
 502         if (likely(fdb)) {
 503                 /* attempt to update an entry for a local interface */
 504                 if (unlikely(fdb->is_local)) {
 505                         if (net_ratelimit())
 506                                 br_warn(br, "received packet on %s with "
 507                                         "own address as source address\n",
 508                                         source->dev->name);
 509                 } else {
 510                         /* fastpath: update of existing entry */
 511                         if (unlikely(source != fdb->dst)) {
 512                                 fdb->dst = source;
 513                                 fdb_modified = true;
 514                         }
 515                         fdb->updated = jiffies;
 516                         if (unlikely(added_by_user))
 517                                 fdb->added_by_user = 1;
 518                         if (unlikely(fdb_modified))
 519                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 520                 }
 521         } else {
 522                 spin_lock(&br->hash_lock);
 523                 if (likely(!fdb_find(head, addr, vid))) {
 524                         fdb = fdb_create(head, source, addr, vid);
 525                         if (fdb) {
 526                                 if (unlikely(added_by_user))
 527                                         fdb->added_by_user = 1;
 528                                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 529                         }
 530                 }
 531                 /* else  we lose race and someone else inserts
 532                  * it first, don't bother updating
 533                  */
 534                 spin_unlock(&br->hash_lock);
 535         }
 536 }
 537
 538 static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
 539 {
 540         if (fdb->is_local)
 541                 return NUD_PERMANENT;
 542         else if (fdb->is_static)
 543                 return NUD_NOARP;
 544         else if (has_expired(fdb->dst->br, fdb))
 545                 return NUD_STALE;
 546         else
 547                 return NUD_REACHABLE;
 548 }
 549
 550 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 551                          const struct net_bridge_fdb_entry *fdb,
 552                          u32 portid, u32 seq, int type, unsigned int flags)
 553 {
 554         unsigned long now = jiffies;
 555         struct nda_cacheinfo ci;
 556         struct nlmsghdr *nlh;
 557         struct ndmsg *ndm;
 558
 559         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 560         if (nlh == NULL)
 561                 return -EMSGSIZE;
 562
 563         ndm = nlmsg_data(nlh);
 564         ndm->ndm_family  = AF_BRIDGE;
 565         ndm->ndm_pad1    = 0;
 566         ndm->ndm_pad2    = 0;
 567         ndm->ndm_flags   = 0;
 568         ndm->ndm_type    = 0;
 569         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 570         ndm->ndm_state   = fdb_to_nud(fdb);
 571
 572         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 573                 goto nla_put_failure;
 574         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 575         ci.ndm_confirmed = 0;
 576         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 577         ci.ndm_refcnt    = 0;
 578         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 579                 goto nla_put_failure;
 580
 581         if (nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 582                 goto nla_put_failure;
 583
 584         return nlmsg_end(skb, nlh);
 585
 586 nla_put_failure:
 587         nlmsg_cancel(skb, nlh);
 588         return -EMSGSIZE;
 589 }
 590
 591 static inline size_t fdb_nlmsg_size(void)
 592 {
 593         return NLMSG_ALIGN(sizeof(struct ndmsg))
 594                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 595                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 596                 + nla_total_size(sizeof(struct nda_cacheinfo));
 597 }
 598
 599 static void fdb_notify(struct net_bridge *br,
 600                        const struct net_bridge_fdb_entry *fdb, int type)
 601 {
 602         struct net *net = dev_net(br->dev);
 603         struct sk_buff *skb;
 604         int err = -ENOBUFS;
 605
 606         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 607         if (skb == NULL)
 608                 goto errout;
 609
 610         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 611         if (err < 0) {
 612                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 613                 WARN_ON(err == -EMSGSIZE);
 614                 kfree_skb(skb);
 615                 goto errout;
 616         }
 617         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 618         return;
 619 errout:
 620         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 621 }
 622
 623 /* Dump information about entries, in response to GETNEIGH */
 624 int br_fdb_dump(struct sk_buff *skb,
 625                 struct netlink_callback *cb,
 626                 struct net_device *dev,
 627                 int idx)
 628 {
 629         struct net_bridge *br = netdev_priv(dev);
 630         int i;
 631
 632         if (!(dev->priv_flags & IFF_EBRIDGE))
 633                 goto out;
 634
 635         for (i = 0; i < BR_HASH_SIZE; i++) {
 636                 struct net_bridge_fdb_entry *f;
 637
 638                 hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 639                         if (idx < cb->args[0])
 640                                 goto skip;
 641
 642                         if (fdb_fill_info(skb, br, f,
 643                                           NETLINK_CB(cb->skb).portid,
 644                                           cb->nlh->nlmsg_seq,
 645                                           RTM_NEWNEIGH,
 646                                           NLM_F_MULTI) < 0)
 647                                 break;
 648 skip:
 649                         ++idx;
 650                 }
 651         }
 652
 653 out:
 654         return idx;
 655 }
 656
 657 /* Update (create or replace) forwarding database entry */
 658 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 659                          __u16 state, __u16 flags, __u16 vid)
 660 {
 661         struct net_bridge *br = source->br;
 662         struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 663         struct net_bridge_fdb_entry *fdb;
 664         bool modified = false;
 665
 666         fdb = fdb_find(head, addr, vid);
 667         if (fdb == NULL) {
 668                 if (!(flags & NLM_F_CREATE))
 669                         return -ENOENT;
 670
 671                 fdb = fdb_create(head, source, addr, vid);
 672                 if (!fdb)
 673                         return -ENOMEM;
 674
 675                 modified = true;
 676         } else {
 677                 if (flags & NLM_F_EXCL)
 678                         return -EEXIST;
 679
 680                 if (fdb->dst != source) {
 681                         fdb->dst = source;
 682                         modified = true;
 683                 }
 684         }
 685
 686         if (fdb_to_nud(fdb) != state) {
 687                 if (state & NUD_PERMANENT)
 688                         fdb->is_local = fdb->is_static = 1;
 689                 else if (state & NUD_NOARP) {
 690                         fdb->is_local = 0;
 691                         fdb->is_static = 1;
 692                 } else
 693                         fdb->is_local = fdb->is_static = 0;
 694
 695                 modified = true;
 696         }
 697         fdb->added_by_user = 1;
 698
 699         fdb->used = jiffies;
 700         if (modified) {
 701                 fdb->updated = jiffies;
 702                 fdb_notify(br, fdb, RTM_NEWNEIGH);
 703         }
 704
 705         return 0;
 706 }
 707
 708 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge_port *p,
 709                const unsigned char *addr, u16 nlh_flags, u16 vid)
 710 {
 711         int err = 0;
 712
 713         if (ndm->ndm_flags & NTF_USE) {
 714                 rcu_read_lock();
 715                 br_fdb_update(p->br, p, addr, vid, true);
 716                 rcu_read_unlock();
 717         } else {
 718                 spin_lock_bh(&p->br->hash_lock);
 719                 err = fdb_add_entry(p, addr, ndm->ndm_state,
 720                                     nlh_flags, vid);
 721                 spin_unlock_bh(&p->br->hash_lock);
 722         }
 723
 724         return err;
 725 }
 726
 727 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 728 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 729                struct net_device *dev,
 730                const unsigned char *addr, u16 nlh_flags)
 731 {
 732         struct net_bridge_port *p;
 733         int err = 0;
 734         struct net_port_vlans *pv;
 735         unsigned short vid = VLAN_N_VID;
 736
 737         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 738                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 739                 return -EINVAL;
 740         }
 741
 742         if (tb[NDA_VLAN]) {
 743                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 744                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 745                         return -EINVAL;
 746                 }
 747
 748                 vid = nla_get_u16(tb[NDA_VLAN]);
 749
 750                 if (!vid || vid >= VLAN_VID_MASK) {
 751                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 752                                 vid);
 753                         return -EINVAL;
 754                 }
 755         }
 756
 757         if (is_zero_ether_addr(addr)) {
 758                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 759                 return -EINVAL;
 760         }
 761
 762         p = br_port_get_rtnl(dev);
 763         if (p == NULL) {
 764                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 765                         dev->name);
 766                 return -EINVAL;
 767         }
 768
 769         pv = nbp_get_vlan_info(p);
 770         if (vid != VLAN_N_VID) {
 771                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 772                         pr_info("bridge: RTM_NEWNEIGH with unconfigured "
 773                                 "vlan %d on port %s\n", vid, dev->name);
 774                         return -EINVAL;
 775                 }
 776
 777                 /* VID was specified, so use it. */
 778                 err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 779         } else {
 780                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 781                         err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 782                         goto out;
 783                 }
 784
 785                 /* We have vlans configured on this port and user didn't
 786                  * specify a VLAN.  To be nice, add/update entry for every
 787                  * vlan on this port.
 788                  */
 789                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 790                         err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 791                         if (err)
 792                                 goto out;
 793                 }
 794         }
 795
 796 out:
 797         return err;
 798 }
 799
 800 static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vlan)
 801 {
 802         struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 803         struct net_bridge_fdb_entry *fdb;
 804
 805         fdb = fdb_find(head, addr, vlan);
 806         if (!fdb)
 807                 return -ENOENT;
 808
 809         fdb_delete(br, fdb);
 810         return 0;
 811 }
 812
 813 static int __br_fdb_delete(struct net_bridge_port *p,
 814                            const unsigned char *addr, u16 vid)
 815 {
 816         int err;
 817
 818         spin_lock_bh(&p->br->hash_lock);
 819         err = fdb_delete_by_addr(p->br, addr, vid);
 820         spin_unlock_bh(&p->br->hash_lock);
 821
 822         return err;
 823 }
 824
 825 /* Remove neighbor entry with RTM_DELNEIGH */
 826 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 827                   struct net_device *dev,
 828                   const unsigned char *addr)
 829 {
 830         struct net_bridge_port *p;
 831         int err;
 832         struct net_port_vlans *pv;
 833         unsigned short vid = VLAN_N_VID;
 834
 835         if (tb[NDA_VLAN]) {
 836                 if (nla_len(tb[NDA_VLAN]) != sizeof(unsigned short)) {
 837                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
 838                         return -EINVAL;
 839                 }
 840
 841                 vid = nla_get_u16(tb[NDA_VLAN]);
 842
 843                 if (!vid || vid >= VLAN_VID_MASK) {
 844                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
 845                                 vid);
 846                         return -EINVAL;
 847                 }
 848         }
 849         p = br_port_get_rtnl(dev);
 850         if (p == NULL) {
 851                 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 852                         dev->name);
 853                 return -EINVAL;
 854         }
 855
 856         pv = nbp_get_vlan_info(p);
 857         if (vid != VLAN_N_VID) {
 858                 if (!pv || !test_bit(vid, pv->vlan_bitmap)) {
 859                         pr_info("bridge: RTM_DELNEIGH with unconfigured "
 860                                 "vlan %d on port %s\n", vid, dev->name);
 861                         return -EINVAL;
 862                 }
 863
 864                 err = __br_fdb_delete(p, addr, vid);
 865         } else {
 866                 if (!pv || bitmap_empty(pv->vlan_bitmap, VLAN_N_VID)) {
 867                         err = __br_fdb_delete(p, addr, 0);
 868                         goto out;
 869                 }
 870
 871                 /* We have vlans configured on this port and user didn't
 872                  * specify a VLAN.  To be nice, add/update entry for every
 873                  * vlan on this port.
 874                  */
 875                 err = -ENOENT;
 876                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 877                         err &= __br_fdb_delete(p, addr, vid);
 878                 }
 879         }
 880 out:
 881         return err;
 882 }