net/bridge/br

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This source file includes following definitions.
br_fdb_init
br_fdb_fini
br_fdb_hash_init
br_fdb_hash_fini
hold_time
has_expired
fdb_rcu_free
fdb_find_rcu
br_fdb_find
br_fdb_find_port
br_fdb_find_rcu
fdb_add_hw_addr
fdb_del_hw_addr
fdb_delete
fdb_delete_local
br_fdb_find_delete_local
br_fdb_changeaddr
br_fdb_change_mac_address
br_fdb_cleanup
br_fdb_flush
br_fdb_delete_by_port
br_fdb_test_addr
br_fdb_fillbuf
fdb_create
fdb_insert
br_fdb_insert
br_fdb_update
fdb_to_nud
fdb_fill_info
fdb_nlmsg_size
fdb_notify
br_fdb_dump
br_fdb_get
fdb_add_entry
__br_fdb_add
br_fdb_add
fdb_delete_by_addr_and_port
__br_fdb_delete
br_fdb_delete
br_fdb_sync_static
br_fdb_unsync_static
br_fdb_external_learn_add
br_fdb_external_learn_del
br_fdb_offloaded_set
br_fdb_clear_offload
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Forwarding database
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Lennert Buytenhek               <buytenh@gnu.org>
   8  */
   9 
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/rculist.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/times.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/jhash.h>
  18 #include <linux/random.h>
  19 #include <linux/slab.h>
  20 #include <linux/atomic.h>
  21 #include <asm/unaligned.h>
  22 #include <linux/if_vlan.h>
  23 #include <net/switchdev.h>
  24 #include <trace/events/bridge.h>
  25 #include "br_private.h"
  26 
  27 static const struct rhashtable_params br_fdb_rht_params = {
  28         .head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
  29         .key_offset = offsetof(struct net_bridge_fdb_entry, key),
  30         .key_len = sizeof(struct net_bridge_fdb_key),
  31         .automatic_shrinking = true,
  32 };
  33 
  34 static struct kmem_cache *br_fdb_cache __read_mostly;
  35 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  36                       const unsigned char *addr, u16 vid);
  37 static void fdb_notify(struct net_bridge *br,
  38                        const struct net_bridge_fdb_entry *, int, bool);
  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         return 0;
  50 }
  51 
  52 void br_fdb_fini(void)
  53 {
  54         kmem_cache_destroy(br_fdb_cache);
  55 }
  56 
  57 int br_fdb_hash_init(struct net_bridge *br)
  58 {
  59         return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
  60 }
  61 
  62 void br_fdb_hash_fini(struct net_bridge *br)
  63 {
  64         rhashtable_destroy(&br->fdb_hash_tbl);
  65 }
  66 
  67 /* if topology_changing then use forward_delay (default 15 sec)
  68  * otherwise keep longer (default 5 minutes)
  69  */
  70 static inline unsigned long hold_time(const struct net_bridge *br)
  71 {
  72         return br->topology_change ? br->forward_delay : br->ageing_time;
  73 }
  74 
  75 static inline int has_expired(const struct net_bridge *br,
  76                                   const struct net_bridge_fdb_entry *fdb)
  77 {
  78         return !fdb->is_static && !fdb->added_by_external_learn &&
  79                 time_before_eq(fdb->updated + hold_time(br), jiffies);
  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 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
  90                                                  const unsigned char *addr,
  91                                                  __u16 vid)
  92 {
  93         struct net_bridge_fdb_key key;
  94 
  95         WARN_ON_ONCE(!rcu_read_lock_held());
  96 
  97         key.vlan_id = vid;
  98         memcpy(key.addr.addr, addr, sizeof(key.addr.addr));
  99 
 100         return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
 101 }
 102 
 103 /* requires bridge hash_lock */
 104 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 105                                                 const unsigned char *addr,
 106                                                 __u16 vid)
 107 {
 108         struct net_bridge_fdb_entry *fdb;
 109 
 110         lockdep_assert_held_once(&br->hash_lock);
 111 
 112         rcu_read_lock();
 113         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 114         rcu_read_unlock();
 115 
 116         return fdb;
 117 }
 118 
 119 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
 120                                     const unsigned char *addr,
 121                                     __u16 vid)
 122 {
 123         struct net_bridge_fdb_entry *f;
 124         struct net_device *dev = NULL;
 125         struct net_bridge *br;
 126 
 127         ASSERT_RTNL();
 128 
 129         if (!netif_is_bridge_master(br_dev))
 130                 return NULL;
 131 
 132         br = netdev_priv(br_dev);
 133         rcu_read_lock();
 134         f = br_fdb_find_rcu(br, addr, vid);
 135         if (f && f->dst)
 136                 dev = f->dst->dev;
 137         rcu_read_unlock();
 138 
 139         return dev;
 140 }
 141 EXPORT_SYMBOL_GPL(br_fdb_find_port);
 142 
 143 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 144                                              const unsigned char *addr,
 145                                              __u16 vid)
 146 {
 147         return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 148 }
 149 
 150 /* When a static FDB entry is added, the mac address from the entry is
 151  * added to the bridge private HW address list and all required ports
 152  * are then updated with the new information.
 153  * Called under RTNL.
 154  */
 155 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 156 {
 157         int err;
 158         struct net_bridge_port *p;
 159 
 160         ASSERT_RTNL();
 161 
 162         list_for_each_entry(p, &br->port_list, list) {
 163                 if (!br_promisc_port(p)) {
 164                         err = dev_uc_add(p->dev, addr);
 165                         if (err)
 166                                 goto undo;
 167                 }
 168         }
 169 
 170         return;
 171 undo:
 172         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 173                 if (!br_promisc_port(p))
 174                         dev_uc_del(p->dev, addr);
 175         }
 176 }
 177 
 178 /* When a static FDB entry is deleted, the HW address from that entry is
 179  * also removed from the bridge private HW address list and updates all
 180  * the ports with needed information.
 181  * Called under RTNL.
 182  */
 183 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 184 {
 185         struct net_bridge_port *p;
 186 
 187         ASSERT_RTNL();
 188 
 189         list_for_each_entry(p, &br->port_list, list) {
 190                 if (!br_promisc_port(p))
 191                         dev_uc_del(p->dev, addr);
 192         }
 193 }
 194 
 195 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
 196                        bool swdev_notify)
 197 {
 198         trace_fdb_delete(br, f);
 199 
 200         if (f->is_static)
 201                 fdb_del_hw_addr(br, f->key.addr.addr);
 202 
 203         hlist_del_init_rcu(&f->fdb_node);
 204         rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
 205                                br_fdb_rht_params);
 206         fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
 207         call_rcu(&f->rcu, fdb_rcu_free);
 208 }
 209 
 210 /* Delete a local entry if no other port had the same address. */
 211 static void fdb_delete_local(struct net_bridge *br,
 212                              const struct net_bridge_port *p,
 213                              struct net_bridge_fdb_entry *f)
 214 {
 215         const unsigned char *addr = f->key.addr.addr;
 216         struct net_bridge_vlan_group *vg;
 217         const struct net_bridge_vlan *v;
 218         struct net_bridge_port *op;
 219         u16 vid = f->key.vlan_id;
 220 
 221         /* Maybe another port has same hw addr? */
 222         list_for_each_entry(op, &br->port_list, list) {
 223                 vg = nbp_vlan_group(op);
 224                 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 225                     (!vid || br_vlan_find(vg, vid))) {
 226                         f->dst = op;
 227                         f->added_by_user = 0;
 228                         return;
 229                 }
 230         }
 231 
 232         vg = br_vlan_group(br);
 233         v = br_vlan_find(vg, vid);
 234         /* Maybe bridge device has same hw addr? */
 235         if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 236             (!vid || (v && br_vlan_should_use(v)))) {
 237                 f->dst = NULL;
 238                 f->added_by_user = 0;
 239                 return;
 240         }
 241 
 242         fdb_delete(br, f, true);
 243 }
 244 
 245 void br_fdb_find_delete_local(struct net_bridge *br,
 246                               const struct net_bridge_port *p,
 247                               const unsigned char *addr, u16 vid)
 248 {
 249         struct net_bridge_fdb_entry *f;
 250 
 251         spin_lock_bh(&br->hash_lock);
 252         f = br_fdb_find(br, addr, vid);
 253         if (f && f->is_local && !f->added_by_user && f->dst == p)
 254                 fdb_delete_local(br, p, f);
 255         spin_unlock_bh(&br->hash_lock);
 256 }
 257 
 258 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 259 {
 260         struct net_bridge_vlan_group *vg;
 261         struct net_bridge_fdb_entry *f;
 262         struct net_bridge *br = p->br;
 263         struct net_bridge_vlan *v;
 264 
 265         spin_lock_bh(&br->hash_lock);
 266         vg = nbp_vlan_group(p);
 267         hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
 268                 if (f->dst == p && f->is_local && !f->added_by_user) {
 269                         /* delete old one */
 270                         fdb_delete_local(br, p, f);
 271 
 272                         /* if this port has no vlan information
 273                          * configured, we can safely be done at
 274                          * this point.
 275                          */
 276                         if (!vg || !vg->num_vlans)
 277                                 goto insert;
 278                 }
 279         }
 280 
 281 insert:
 282         /* insert new address,  may fail if invalid address or dup. */
 283         fdb_insert(br, p, newaddr, 0);
 284 
 285         if (!vg || !vg->num_vlans)
 286                 goto done;
 287 
 288         /* Now add entries for every VLAN configured on the port.
 289          * This function runs under RTNL so the bitmap will not change
 290          * from under us.
 291          */
 292         list_for_each_entry(v, &vg->vlan_list, vlist)
 293                 fdb_insert(br, p, newaddr, v->vid);
 294 
 295 done:
 296         spin_unlock_bh(&br->hash_lock);
 297 }
 298 
 299 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 300 {
 301         struct net_bridge_vlan_group *vg;
 302         struct net_bridge_fdb_entry *f;
 303         struct net_bridge_vlan *v;
 304 
 305         spin_lock_bh(&br->hash_lock);
 306 
 307         /* If old entry was unassociated with any port, then delete it. */
 308         f = br_fdb_find(br, br->dev->dev_addr, 0);
 309         if (f && f->is_local && !f->dst && !f->added_by_user)
 310                 fdb_delete_local(br, NULL, f);
 311 
 312         fdb_insert(br, NULL, newaddr, 0);
 313         vg = br_vlan_group(br);
 314         if (!vg || !vg->num_vlans)
 315                 goto out;
 316         /* Now remove and add entries for every VLAN configured on the
 317          * bridge.  This function runs under RTNL so the bitmap will not
 318          * change from under us.
 319          */
 320         list_for_each_entry(v, &vg->vlan_list, vlist) {
 321                 if (!br_vlan_should_use(v))
 322                         continue;
 323                 f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 324                 if (f && f->is_local && !f->dst && !f->added_by_user)
 325                         fdb_delete_local(br, NULL, f);
 326                 fdb_insert(br, NULL, newaddr, v->vid);
 327         }
 328 out:
 329         spin_unlock_bh(&br->hash_lock);
 330 }
 331 
 332 void br_fdb_cleanup(struct work_struct *work)
 333 {
 334         struct net_bridge *br = container_of(work, struct net_bridge,
 335                                              gc_work.work);
 336         struct net_bridge_fdb_entry *f = NULL;
 337         unsigned long delay = hold_time(br);
 338         unsigned long work_delay = delay;
 339         unsigned long now = jiffies;
 340 
 341         /* this part is tricky, in order to avoid blocking learning and
 342          * consequently forwarding, we rely on rcu to delete objects with
 343          * delayed freeing allowing us to continue traversing
 344          */
 345         rcu_read_lock();
 346         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 347                 unsigned long this_timer;
 348 
 349                 if (f->is_static || f->added_by_external_learn)
 350                         continue;
 351                 this_timer = f->updated + delay;
 352                 if (time_after(this_timer, now)) {
 353                         work_delay = min(work_delay, this_timer - now);
 354                 } else {
 355                         spin_lock_bh(&br->hash_lock);
 356                         if (!hlist_unhashed(&f->fdb_node))
 357                                 fdb_delete(br, f, true);
 358                         spin_unlock_bh(&br->hash_lock);
 359                 }
 360         }
 361         rcu_read_unlock();
 362 
 363         /* Cleanup minimum 10 milliseconds apart */
 364         work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 365         mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 366 }
 367 
 368 /* Completely flush all dynamic entries in forwarding database.*/
 369 void br_fdb_flush(struct net_bridge *br)
 370 {
 371         struct net_bridge_fdb_entry *f;
 372         struct hlist_node *tmp;
 373 
 374         spin_lock_bh(&br->hash_lock);
 375         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 376                 if (!f->is_static)
 377                         fdb_delete(br, f, true);
 378         }
 379         spin_unlock_bh(&br->hash_lock);
 380 }
 381 
 382 /* Flush all entries referring to a specific port.
 383  * if do_all is set also flush static entries
 384  * if vid is set delete all entries that match the vlan_id
 385  */
 386 void br_fdb_delete_by_port(struct net_bridge *br,
 387                            const struct net_bridge_port *p,
 388                            u16 vid,
 389                            int do_all)
 390 {
 391         struct net_bridge_fdb_entry *f;
 392         struct hlist_node *tmp;
 393 
 394         spin_lock_bh(&br->hash_lock);
 395         hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
 396                 if (f->dst != p)
 397                         continue;
 398 
 399                 if (!do_all)
 400                         if (f->is_static || (vid && f->key.vlan_id != vid))
 401                                 continue;
 402 
 403                 if (f->is_local)
 404                         fdb_delete_local(br, p, f);
 405                 else
 406                         fdb_delete(br, f, true);
 407         }
 408         spin_unlock_bh(&br->hash_lock);
 409 }
 410 
 411 #if IS_ENABLED(CONFIG_ATM_LANE)
 412 /* Interface used by ATM LANE hook to test
 413  * if an addr is on some other bridge port */
 414 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 415 {
 416         struct net_bridge_fdb_entry *fdb;
 417         struct net_bridge_port *port;
 418         int ret;
 419 
 420         rcu_read_lock();
 421         port = br_port_get_rcu(dev);
 422         if (!port)
 423                 ret = 0;
 424         else {
 425                 fdb = br_fdb_find_rcu(port->br, addr, 0);
 426                 ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 427                         fdb->dst->state == BR_STATE_FORWARDING;
 428         }
 429         rcu_read_unlock();
 430 
 431         return ret;
 432 }
 433 #endif /* CONFIG_ATM_LANE */
 434 
 435 /*
 436  * Fill buffer with forwarding table records in
 437  * the API format.
 438  */
 439 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 440                    unsigned long maxnum, unsigned long skip)
 441 {
 442         struct net_bridge_fdb_entry *f;
 443         struct __fdb_entry *fe = buf;
 444         int num = 0;
 445 
 446         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 447 
 448         rcu_read_lock();
 449         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 450                 if (num >= maxnum)
 451                         break;
 452 
 453                 if (has_expired(br, f))
 454                         continue;
 455 
 456                 /* ignore pseudo entry for local MAC address */
 457                 if (!f->dst)
 458                         continue;
 459 
 460                 if (skip) {
 461                         --skip;
 462                         continue;
 463                 }
 464 
 465                 /* convert from internal format to API */
 466                 memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);
 467 
 468                 /* due to ABI compat need to split into hi/lo */
 469                 fe->port_no = f->dst->port_no;
 470                 fe->port_hi = f->dst->port_no >> 8;
 471 
 472                 fe->is_local = f->is_local;
 473                 if (!f->is_static)
 474                         fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 475                 ++fe;
 476                 ++num;
 477         }
 478         rcu_read_unlock();
 479 
 480         return num;
 481 }
 482 
 483 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
 484                                                struct net_bridge_port *source,
 485                                                const unsigned char *addr,
 486                                                __u16 vid,
 487                                                unsigned char is_local,
 488                                                unsigned char is_static)
 489 {
 490         struct net_bridge_fdb_entry *fdb;
 491 
 492         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 493         if (fdb) {
 494                 memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
 495                 fdb->dst = source;
 496                 fdb->key.vlan_id = vid;
 497                 fdb->is_local = is_local;
 498                 fdb->is_static = is_static;
 499                 fdb->added_by_user = 0;
 500                 fdb->added_by_external_learn = 0;
 501                 fdb->offloaded = 0;
 502                 fdb->is_sticky = 0;
 503                 fdb->updated = fdb->used = jiffies;
 504                 if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl,
 505                                                   &fdb->rhnode,
 506                                                   br_fdb_rht_params)) {
 507                         kmem_cache_free(br_fdb_cache, fdb);
 508                         fdb = NULL;
 509                 } else {
 510                         hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);
 511                 }
 512         }
 513         return fdb;
 514 }
 515 
 516 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 517                   const unsigned char *addr, u16 vid)
 518 {
 519         struct net_bridge_fdb_entry *fdb;
 520 
 521         if (!is_valid_ether_addr(addr))
 522                 return -EINVAL;
 523 
 524         fdb = br_fdb_find(br, addr, vid);
 525         if (fdb) {
 526                 /* it is okay to have multiple ports with same
 527                  * address, just use the first one.
 528                  */
 529                 if (fdb->is_local)
 530                         return 0;
 531                 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 532                        source ? source->dev->name : br->dev->name, addr, vid);
 533                 fdb_delete(br, fdb, true);
 534         }
 535 
 536         fdb = fdb_create(br, source, addr, vid, 1, 1);
 537         if (!fdb)
 538                 return -ENOMEM;
 539 
 540         fdb_add_hw_addr(br, addr);
 541         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 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 net_bridge_fdb_entry *fdb;
 561         bool fdb_modified = false;
 562 
 563         /* some users want to always flood. */
 564         if (hold_time(br) == 0)
 565                 return;
 566 
 567         /* ignore packets unless we are using this port */
 568         if (!(source->state == BR_STATE_LEARNING ||
 569               source->state == BR_STATE_FORWARDING))
 570                 return;
 571 
 572         fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
 573         if (likely(fdb)) {
 574                 /* attempt to update an entry for a local interface */
 575                 if (unlikely(fdb->is_local)) {
 576                         if (net_ratelimit())
 577                                 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 578                                         source->dev->name, addr, vid);
 579                 } else {
 580                         unsigned long now = jiffies;
 581 
 582                         /* fastpath: update of existing entry */
 583                         if (unlikely(source != fdb->dst && !fdb->is_sticky)) {
 584                                 fdb->dst = source;
 585                                 fdb_modified = true;
 586                                 /* Take over HW learned entry */
 587                                 if (unlikely(fdb->added_by_external_learn))
 588                                         fdb->added_by_external_learn = 0;
 589                         }
 590                         if (now != fdb->updated)
 591                                 fdb->updated = now;
 592                         if (unlikely(added_by_user))
 593                                 fdb->added_by_user = 1;
 594                         if (unlikely(fdb_modified)) {
 595                                 trace_br_fdb_update(br, source, addr, vid, added_by_user);
 596                                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 597                         }
 598                 }
 599         } else {
 600                 spin_lock(&br->hash_lock);
 601                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 602                 if (fdb) {
 603                         if (unlikely(added_by_user))
 604                                 fdb->added_by_user = 1;
 605                         trace_br_fdb_update(br, source, addr, vid,
 606                                             added_by_user);
 607                         fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 608                 }
 609                 /* else  we lose race and someone else inserts
 610                  * it first, don't bother updating
 611                  */
 612                 spin_unlock(&br->hash_lock);
 613         }
 614 }
 615 
 616 static int fdb_to_nud(const struct net_bridge *br,
 617                       const struct net_bridge_fdb_entry *fdb)
 618 {
 619         if (fdb->is_local)
 620                 return NUD_PERMANENT;
 621         else if (fdb->is_static)
 622                 return NUD_NOARP;
 623         else if (has_expired(br, fdb))
 624                 return NUD_STALE;
 625         else
 626                 return NUD_REACHABLE;
 627 }
 628 
 629 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 630                          const struct net_bridge_fdb_entry *fdb,
 631                          u32 portid, u32 seq, int type, unsigned int flags)
 632 {
 633         unsigned long now = jiffies;
 634         struct nda_cacheinfo ci;
 635         struct nlmsghdr *nlh;
 636         struct ndmsg *ndm;
 637 
 638         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 639         if (nlh == NULL)
 640                 return -EMSGSIZE;
 641 
 642         ndm = nlmsg_data(nlh);
 643         ndm->ndm_family  = AF_BRIDGE;
 644         ndm->ndm_pad1    = 0;
 645         ndm->ndm_pad2    = 0;
 646         ndm->ndm_flags   = 0;
 647         ndm->ndm_type    = 0;
 648         ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 649         ndm->ndm_state   = fdb_to_nud(br, fdb);
 650 
 651         if (fdb->offloaded)
 652                 ndm->ndm_flags |= NTF_OFFLOADED;
 653         if (fdb->added_by_external_learn)
 654                 ndm->ndm_flags |= NTF_EXT_LEARNED;
 655         if (fdb->is_sticky)
 656                 ndm->ndm_flags |= NTF_STICKY;
 657 
 658         if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
 659                 goto nla_put_failure;
 660         if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 661                 goto nla_put_failure;
 662         ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 663         ci.ndm_confirmed = 0;
 664         ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 665         ci.ndm_refcnt    = 0;
 666         if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 667                 goto nla_put_failure;
 668 
 669         if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
 670                                         &fdb->key.vlan_id))
 671                 goto nla_put_failure;
 672 
 673         nlmsg_end(skb, nlh);
 674         return 0;
 675 
 676 nla_put_failure:
 677         nlmsg_cancel(skb, nlh);
 678         return -EMSGSIZE;
 679 }
 680 
 681 static inline size_t fdb_nlmsg_size(void)
 682 {
 683         return NLMSG_ALIGN(sizeof(struct ndmsg))
 684                 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 685                 + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 686                 + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 687                 + nla_total_size(sizeof(struct nda_cacheinfo));
 688 }
 689 
 690 static void fdb_notify(struct net_bridge *br,
 691                        const struct net_bridge_fdb_entry *fdb, int type,
 692                        bool swdev_notify)
 693 {
 694         struct net *net = dev_net(br->dev);
 695         struct sk_buff *skb;
 696         int err = -ENOBUFS;
 697 
 698         if (swdev_notify)
 699                 br_switchdev_fdb_notify(fdb, type);
 700 
 701         skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 702         if (skb == NULL)
 703                 goto errout;
 704 
 705         err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 706         if (err < 0) {
 707                 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 708                 WARN_ON(err == -EMSGSIZE);
 709                 kfree_skb(skb);
 710                 goto errout;
 711         }
 712         rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 713         return;
 714 errout:
 715         rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 716 }
 717 
 718 /* Dump information about entries, in response to GETNEIGH */
 719 int br_fdb_dump(struct sk_buff *skb,
 720                 struct netlink_callback *cb,
 721                 struct net_device *dev,
 722                 struct net_device *filter_dev,
 723                 int *idx)
 724 {
 725         struct net_bridge *br = netdev_priv(dev);
 726         struct net_bridge_fdb_entry *f;
 727         int err = 0;
 728 
 729         if (!(dev->priv_flags & IFF_EBRIDGE))
 730                 return err;
 731 
 732         if (!filter_dev) {
 733                 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 734                 if (err < 0)
 735                         return err;
 736         }
 737 
 738         rcu_read_lock();
 739         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
 740                 if (*idx < cb->args[2])
 741                         goto skip;
 742                 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 743                         if (filter_dev != dev)
 744                                 goto skip;
 745                         /* !f->dst is a special case for bridge
 746                          * It means the MAC belongs to the bridge
 747                          * Therefore need a little more filtering
 748                          * we only want to dump the !f->dst case
 749                          */
 750                         if (f->dst)
 751                                 goto skip;
 752                 }
 753                 if (!filter_dev && f->dst)
 754                         goto skip;
 755 
 756                 err = fdb_fill_info(skb, br, f,
 757                                     NETLINK_CB(cb->skb).portid,
 758                                     cb->nlh->nlmsg_seq,
 759                                     RTM_NEWNEIGH,
 760                                     NLM_F_MULTI);
 761                 if (err < 0)
 762                         break;
 763 skip:
 764                 *idx += 1;
 765         }
 766         rcu_read_unlock();
 767 
 768         return err;
 769 }
 770 
 771 int br_fdb_get(struct sk_buff *skb,
 772                struct nlattr *tb[],
 773                struct net_device *dev,
 774                const unsigned char *addr,
 775                u16 vid, u32 portid, u32 seq,
 776                struct netlink_ext_ack *extack)
 777 {
 778         struct net_bridge *br = netdev_priv(dev);
 779         struct net_bridge_fdb_entry *f;
 780         int err = 0;
 781 
 782         rcu_read_lock();
 783         f = br_fdb_find_rcu(br, addr, vid);
 784         if (!f) {
 785                 NL_SET_ERR_MSG(extack, "Fdb entry not found");
 786                 err = -ENOENT;
 787                 goto errout;
 788         }
 789 
 790         err = fdb_fill_info(skb, br, f, portid, seq,
 791                             RTM_NEWNEIGH, 0);
 792 errout:
 793         rcu_read_unlock();
 794         return err;
 795 }
 796 
 797 /* Update (create or replace) forwarding database entry */
 798 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 799                          const u8 *addr, u16 state, u16 flags, u16 vid,
 800                          u8 ndm_flags)
 801 {
 802         u8 is_sticky = !!(ndm_flags & NTF_STICKY);
 803         struct net_bridge_fdb_entry *fdb;
 804         bool modified = false;
 805 
 806         /* If the port cannot learn allow only local and static entries */
 807         if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 808             !(source->state == BR_STATE_LEARNING ||
 809               source->state == BR_STATE_FORWARDING))
 810                 return -EPERM;
 811 
 812         if (!source && !(state & NUD_PERMANENT)) {
 813                 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 814                         br->dev->name);
 815                 return -EINVAL;
 816         }
 817 
 818         if (is_sticky && (state & NUD_PERMANENT))
 819                 return -EINVAL;
 820 
 821         fdb = br_fdb_find(br, addr, vid);
 822         if (fdb == NULL) {
 823                 if (!(flags & NLM_F_CREATE))
 824                         return -ENOENT;
 825 
 826                 fdb = fdb_create(br, source, addr, vid, 0, 0);
 827                 if (!fdb)
 828                         return -ENOMEM;
 829 
 830                 modified = true;
 831         } else {
 832                 if (flags & NLM_F_EXCL)
 833                         return -EEXIST;
 834 
 835                 if (fdb->dst != source) {
 836                         fdb->dst = source;
 837                         modified = true;
 838                 }
 839         }
 840 
 841         if (fdb_to_nud(br, fdb) != state) {
 842                 if (state & NUD_PERMANENT) {
 843                         fdb->is_local = 1;
 844                         if (!fdb->is_static) {
 845                                 fdb->is_static = 1;
 846                                 fdb_add_hw_addr(br, addr);
 847                         }
 848                 } else if (state & NUD_NOARP) {
 849                         fdb->is_local = 0;
 850                         if (!fdb->is_static) {
 851                                 fdb->is_static = 1;
 852                                 fdb_add_hw_addr(br, addr);
 853                         }
 854                 } else {
 855                         fdb->is_local = 0;
 856                         if (fdb->is_static) {
 857                                 fdb->is_static = 0;
 858                                 fdb_del_hw_addr(br, addr);
 859                         }
 860                 }
 861 
 862                 modified = true;
 863         }
 864 
 865         if (is_sticky != fdb->is_sticky) {
 866                 fdb->is_sticky = is_sticky;
 867                 modified = true;
 868         }
 869 
 870         fdb->added_by_user = 1;
 871 
 872         fdb->used = jiffies;
 873         if (modified) {
 874                 fdb->updated = jiffies;
 875                 fdb_notify(br, fdb, RTM_NEWNEIGH, true);
 876         }
 877 
 878         return 0;
 879 }
 880 
 881 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 882                         struct net_bridge_port *p, const unsigned char *addr,
 883                         u16 nlh_flags, u16 vid)
 884 {
 885         int err = 0;
 886 
 887         if (ndm->ndm_flags & NTF_USE) {
 888                 if (!p) {
 889                         pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 890                                 br->dev->name);
 891                         return -EINVAL;
 892                 }
 893                 local_bh_disable();
 894                 rcu_read_lock();
 895                 br_fdb_update(br, p, addr, vid, true);
 896                 rcu_read_unlock();
 897                 local_bh_enable();
 898         } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 899                 err = br_fdb_external_learn_add(br, p, addr, vid, true);
 900         } else {
 901                 spin_lock_bh(&br->hash_lock);
 902                 err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 903                                     nlh_flags, vid, ndm->ndm_flags);
 904                 spin_unlock_bh(&br->hash_lock);
 905         }
 906 
 907         return err;
 908 }
 909 
 910 /* Add new permanent fdb entry with RTM_NEWNEIGH */
 911 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 912                struct net_device *dev,
 913                const unsigned char *addr, u16 vid, u16 nlh_flags,
 914                struct netlink_ext_ack *extack)
 915 {
 916         struct net_bridge_vlan_group *vg;
 917         struct net_bridge_port *p = NULL;
 918         struct net_bridge_vlan *v;
 919         struct net_bridge *br = NULL;
 920         int err = 0;
 921 
 922         trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 923 
 924         if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 925                 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 926                 return -EINVAL;
 927         }
 928 
 929         if (is_zero_ether_addr(addr)) {
 930                 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 931                 return -EINVAL;
 932         }
 933 
 934         if (dev->priv_flags & IFF_EBRIDGE) {
 935                 br = netdev_priv(dev);
 936                 vg = br_vlan_group(br);
 937         } else {
 938                 p = br_port_get_rtnl(dev);
 939                 if (!p) {
 940                         pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 941                                 dev->name);
 942                         return -EINVAL;
 943                 }
 944                 br = p->br;
 945                 vg = nbp_vlan_group(p);
 946         }
 947 
 948         if (vid) {
 949                 v = br_vlan_find(vg, vid);
 950                 if (!v || !br_vlan_should_use(v)) {
 951                         pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 952                         return -EINVAL;
 953                 }
 954 
 955                 /* VID was specified, so use it. */
 956                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 957         } else {
 958                 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 959                 if (err || !vg || !vg->num_vlans)
 960                         goto out;
 961 
 962                 /* We have vlans configured on this port and user didn't
 963                  * specify a VLAN.  To be nice, add/update entry for every
 964                  * vlan on this port.
 965                  */
 966                 list_for_each_entry(v, &vg->vlan_list, vlist) {
 967                         if (!br_vlan_should_use(v))
 968                                 continue;
 969                         err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 970                         if (err)
 971                                 goto out;
 972                 }
 973         }
 974 
 975 out:
 976         return err;
 977 }
 978 
 979 static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 980                                        const struct net_bridge_port *p,
 981                                        const u8 *addr, u16 vlan)
 982 {
 983         struct net_bridge_fdb_entry *fdb;
 984 
 985         fdb = br_fdb_find(br, addr, vlan);
 986         if (!fdb || fdb->dst != p)
 987                 return -ENOENT;
 988 
 989         fdb_delete(br, fdb, true);
 990 
 991         return 0;
 992 }
 993 
 994 static int __br_fdb_delete(struct net_bridge *br,
 995                            const struct net_bridge_port *p,
 996                            const unsigned char *addr, u16 vid)
 997 {
 998         int err;
 999 
1000         spin_lock_bh(&br->hash_lock);
1001         err = fdb_delete_by_addr_and_port(br, p, addr, vid);
1002         spin_unlock_bh(&br->hash_lock);
1003 
1004         return err;
1005 }
1006 
1007 /* Remove neighbor entry with RTM_DELNEIGH */
1008 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
1009                   struct net_device *dev,
1010                   const unsigned char *addr, u16 vid)
1011 {
1012         struct net_bridge_vlan_group *vg;
1013         struct net_bridge_port *p = NULL;
1014         struct net_bridge_vlan *v;
1015         struct net_bridge *br;
1016         int err;
1017 
1018         if (dev->priv_flags & IFF_EBRIDGE) {
1019                 br = netdev_priv(dev);
1020                 vg = br_vlan_group(br);
1021         } else {
1022                 p = br_port_get_rtnl(dev);
1023                 if (!p) {
1024                         pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1025                                 dev->name);
1026                         return -EINVAL;
1027                 }
1028                 vg = nbp_vlan_group(p);
1029                 br = p->br;
1030         }
1031 
1032         if (vid) {
1033                 v = br_vlan_find(vg, vid);
1034                 if (!v) {
1035                         pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1036                         return -EINVAL;
1037                 }
1038 
1039                 err = __br_fdb_delete(br, p, addr, vid);
1040         } else {
1041                 err = -ENOENT;
1042                 err &= __br_fdb_delete(br, p, addr, 0);
1043                 if (!vg || !vg->num_vlans)
1044                         return err;
1045 
1046                 list_for_each_entry(v, &vg->vlan_list, vlist) {
1047                         if (!br_vlan_should_use(v))
1048                                 continue;
1049                         err &= __br_fdb_delete(br, p, addr, v->vid);
1050                 }
1051         }
1052 
1053         return err;
1054 }
1055 
1056 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1057 {
1058         struct net_bridge_fdb_entry *f, *tmp;
1059         int err = 0;
1060 
1061         ASSERT_RTNL();
1062 
1063         /* the key here is that static entries change only under rtnl */
1064         rcu_read_lock();
1065         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1066                 /* We only care for static entries */
1067                 if (!f->is_static)
1068                         continue;
1069                 err = dev_uc_add(p->dev, f->key.addr.addr);
1070                 if (err)
1071                         goto rollback;
1072         }
1073 done:
1074         rcu_read_unlock();
1075 
1076         return err;
1077 
1078 rollback:
1079         hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
1080                 /* We only care for static entries */
1081                 if (!tmp->is_static)
1082                         continue;
1083                 if (tmp == f)
1084                         break;
1085                 dev_uc_del(p->dev, tmp->key.addr.addr);
1086         }
1087 
1088         goto done;
1089 }
1090 
1091 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1092 {
1093         struct net_bridge_fdb_entry *f;
1094 
1095         ASSERT_RTNL();
1096 
1097         rcu_read_lock();
1098         hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
1099                 /* We only care for static entries */
1100                 if (!f->is_static)
1101                         continue;
1102 
1103                 dev_uc_del(p->dev, f->key.addr.addr);
1104         }
1105         rcu_read_unlock();
1106 }
1107 
1108 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1109                               const unsigned char *addr, u16 vid,
1110                               bool swdev_notify)
1111 {
1112         struct net_bridge_fdb_entry *fdb;
1113         bool modified = false;
1114         int err = 0;
1115 
1116         trace_br_fdb_external_learn_add(br, p, addr, vid);
1117 
1118         spin_lock_bh(&br->hash_lock);
1119 
1120         fdb = br_fdb_find(br, addr, vid);
1121         if (!fdb) {
1122                 fdb = fdb_create(br, p, addr, vid, 0, 0);
1123                 if (!fdb) {
1124                         err = -ENOMEM;
1125                         goto err_unlock;
1126                 }
1127                 if (swdev_notify)
1128                         fdb->added_by_user = 1;
1129                 fdb->added_by_external_learn = 1;
1130                 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1131         } else {
1132                 fdb->updated = jiffies;
1133 
1134                 if (fdb->dst != p) {
1135                         fdb->dst = p;
1136                         modified = true;
1137                 }
1138 
1139                 if (fdb->added_by_external_learn) {
1140                         /* Refresh entry */
1141                         fdb->used = jiffies;
1142                 } else if (!fdb->added_by_user) {
1143                         /* Take over SW learned entry */
1144                         fdb->added_by_external_learn = 1;
1145                         modified = true;
1146                 }
1147 
1148                 if (swdev_notify)
1149                         fdb->added_by_user = 1;
1150 
1151                 if (modified)
1152                         fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
1153         }
1154 
1155 err_unlock:
1156         spin_unlock_bh(&br->hash_lock);
1157 
1158         return err;
1159 }
1160 
1161 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1162                               const unsigned char *addr, u16 vid,
1163                               bool swdev_notify)
1164 {
1165         struct net_bridge_fdb_entry *fdb;
1166         int err = 0;
1167 
1168         spin_lock_bh(&br->hash_lock);
1169 
1170         fdb = br_fdb_find(br, addr, vid);
1171         if (fdb && fdb->added_by_external_learn)
1172                 fdb_delete(br, fdb, swdev_notify);
1173         else
1174                 err = -ENOENT;
1175 
1176         spin_unlock_bh(&br->hash_lock);
1177 
1178         return err;
1179 }
1180 
1181 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1182                           const unsigned char *addr, u16 vid, bool offloaded)
1183 {
1184         struct net_bridge_fdb_entry *fdb;
1185 
1186         spin_lock_bh(&br->hash_lock);
1187 
1188         fdb = br_fdb_find(br, addr, vid);
1189         if (fdb)
1190                 fdb->offloaded = offloaded;
1191 
1192         spin_unlock_bh(&br->hash_lock);
1193 }
1194 
1195 void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
1196 {
1197         struct net_bridge_fdb_entry *f;
1198         struct net_bridge_port *p;
1199 
1200         ASSERT_RTNL();
1201 
1202         p = br_port_get_rtnl(dev);
1203         if (!p)
1204                 return;
1205 
1206         spin_lock_bh(&p->br->hash_lock);
1207         hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
1208                 if (f->dst == p && f->key.vlan_id == vid)
1209                         f->offloaded = 0;
1210         }
1211         spin_unlock_bh(&p->br->hash_lock);
1212 }
1213 EXPORT_SYMBOL_GPL(br_fdb_clear_offload);
/* [<][>][^][v][top][bottom][index][help] */
root/net/bridge/br_fdb.c

DEFINITIONS
