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 !test_bit(BR_FDB_STATIC, &fdb->flags) && 79 !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) && 80 time_before_eq(fdb->updated + hold_time(br), jiffies); 81 } 82 83 static void fdb_rcu_free(struct rcu_head *head) 84 { 85 struct net_bridge_fdb_entry *ent 86 = container_of(head, struct net_bridge_fdb_entry, rcu); 87 kmem_cache_free(br_fdb_cache, ent); 88 } 89 90 static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl, 91 const unsigned char *addr, 92 __u16 vid) 93 { 94 struct net_bridge_fdb_key key; 95 96 WARN_ON_ONCE(!rcu_read_lock_held()); 97 98 key.vlan_id = vid; 99 memcpy(key.addr.addr, addr, sizeof(key.addr.addr)); 100 101 return rhashtable_lookup(tbl, &key, br_fdb_rht_params); 102 } 103 104 /* requires bridge hash_lock */ 105 static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br, 106 const unsigned char *addr, 107 __u16 vid) 108 { 109 struct net_bridge_fdb_entry *fdb; 110 111 lockdep_assert_held_once(&br->hash_lock); 112 113 rcu_read_lock(); 114 fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); 115 rcu_read_unlock(); 116 117 return fdb; 118 } 119 120 struct net_device *br_fdb_find_port(const struct net_device *br_dev, 121 const unsigned char *addr, 122 __u16 vid) 123 { 124 struct net_bridge_fdb_entry *f; 125 struct net_device *dev = NULL; 126 struct net_bridge *br; 127 128 ASSERT_RTNL(); 129 130 if (!netif_is_bridge_master(br_dev)) 131 return NULL; 132 133 br = netdev_priv(br_dev); 134 rcu_read_lock(); 135 f = br_fdb_find_rcu(br, addr, vid); 136 if (f && f->dst) 137 dev = f->dst->dev; 138 rcu_read_unlock(); 139 140 return dev; 141 } 142 EXPORT_SYMBOL_GPL(br_fdb_find_port); 143 144 struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br, 145 const unsigned char *addr, 146 __u16 vid) 147 { 148 return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); 149 } 150 151 /* When a static FDB entry is added, the mac address from the entry is 152 * added to the bridge private HW address list and all required ports 153 * are then updated with the new information. 154 * Called under RTNL. 155 */ 156 static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr) 157 { 158 int err; 159 struct net_bridge_port *p; 160 161 ASSERT_RTNL(); 162 163 list_for_each_entry(p, &br->port_list, list) { 164 if (!br_promisc_port(p)) { 165 err = dev_uc_add(p->dev, addr); 166 if (err) 167 goto undo; 168 } 169 } 170 171 return; 172 undo: 173 list_for_each_entry_continue_reverse(p, &br->port_list, list) { 174 if (!br_promisc_port(p)) 175 dev_uc_del(p->dev, addr); 176 } 177 } 178 179 /* When a static FDB entry is deleted, the HW address from that entry is 180 * also removed from the bridge private HW address list and updates all 181 * the ports with needed information. 182 * Called under RTNL. 183 */ 184 static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr) 185 { 186 struct net_bridge_port *p; 187 188 ASSERT_RTNL(); 189 190 list_for_each_entry(p, &br->port_list, list) { 191 if (!br_promisc_port(p)) 192 dev_uc_del(p->dev, addr); 193 } 194 } 195 196 static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f, 197 bool swdev_notify) 198 { 199 trace_fdb_delete(br, f); 200 201 if (test_bit(BR_FDB_STATIC, &f->flags)) 202 fdb_del_hw_addr(br, f->key.addr.addr); 203 204 hlist_del_init_rcu(&f->fdb_node); 205 rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode, 206 br_fdb_rht_params); 207 fdb_notify(br, f, RTM_DELNEIGH, swdev_notify); 208 call_rcu(&f->rcu, fdb_rcu_free); 209 } 210 211 /* Delete a local entry if no other port had the same address. */ 212 static void fdb_delete_local(struct net_bridge *br, 213 const struct net_bridge_port *p, 214 struct net_bridge_fdb_entry *f) 215 { 216 const unsigned char *addr = f->key.addr.addr; 217 struct net_bridge_vlan_group *vg; 218 const struct net_bridge_vlan *v; 219 struct net_bridge_port *op; 220 u16 vid = f->key.vlan_id; 221 222 /* Maybe another port has same hw addr? */ 223 list_for_each_entry(op, &br->port_list, list) { 224 vg = nbp_vlan_group(op); 225 if (op != p && ether_addr_equal(op->dev->dev_addr, addr) && 226 (!vid || br_vlan_find(vg, vid))) { 227 f->dst = op; 228 clear_bit(BR_FDB_ADDED_BY_USER, &f->flags); 229 return; 230 } 231 } 232 233 vg = br_vlan_group(br); 234 v = br_vlan_find(vg, vid); 235 /* Maybe bridge device has same hw addr? */ 236 if (p && ether_addr_equal(br->dev->dev_addr, addr) && 237 (!vid || (v && br_vlan_should_use(v)))) { 238 f->dst = NULL; 239 clear_bit(BR_FDB_ADDED_BY_USER, &f->flags); 240 return; 241 } 242 243 fdb_delete(br, f, true); 244 } 245 246 void br_fdb_find_delete_local(struct net_bridge *br, 247 const struct net_bridge_port *p, 248 const unsigned char *addr, u16 vid) 249 { 250 struct net_bridge_fdb_entry *f; 251 252 spin_lock_bh(&br->hash_lock); 253 f = br_fdb_find(br, addr, vid); 254 if (f && test_bit(BR_FDB_LOCAL, &f->flags) && 255 !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p) 256 fdb_delete_local(br, p, f); 257 spin_unlock_bh(&br->hash_lock); 258 } 259 260 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr) 261 { 262 struct net_bridge_vlan_group *vg; 263 struct net_bridge_fdb_entry *f; 264 struct net_bridge *br = p->br; 265 struct net_bridge_vlan *v; 266 267 spin_lock_bh(&br->hash_lock); 268 vg = nbp_vlan_group(p); 269 hlist_for_each_entry(f, &br->fdb_list, fdb_node) { 270 if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) && 271 !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) { 272 /* delete old one */ 273 fdb_delete_local(br, p, f); 274 275 /* if this port has no vlan information 276 * configured, we can safely be done at 277 * this point. 278 */ 279 if (!vg || !vg->num_vlans) 280 goto insert; 281 } 282 } 283 284 insert: 285 /* insert new address, may fail if invalid address or dup. */ 286 fdb_insert(br, p, newaddr, 0); 287 288 if (!vg || !vg->num_vlans) 289 goto done; 290 291 /* Now add entries for every VLAN configured on the port. 292 * This function runs under RTNL so the bitmap will not change 293 * from under us. 294 */ 295 list_for_each_entry(v, &vg->vlan_list, vlist) 296 fdb_insert(br, p, newaddr, v->vid); 297 298 done: 299 spin_unlock_bh(&br->hash_lock); 300 } 301 302 void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) 303 { 304 struct net_bridge_vlan_group *vg; 305 struct net_bridge_fdb_entry *f; 306 struct net_bridge_vlan *v; 307 308 spin_lock_bh(&br->hash_lock); 309 310 /* If old entry was unassociated with any port, then delete it. */ 311 f = br_fdb_find(br, br->dev->dev_addr, 0); 312 if (f && test_bit(BR_FDB_LOCAL, &f->flags) && 313 !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) 314 fdb_delete_local(br, NULL, f); 315 316 fdb_insert(br, NULL, newaddr, 0); 317 vg = br_vlan_group(br); 318 if (!vg || !vg->num_vlans) 319 goto out; 320 /* Now remove and add entries for every VLAN configured on the 321 * bridge. This function runs under RTNL so the bitmap will not 322 * change from under us. 323 */ 324 list_for_each_entry(v, &vg->vlan_list, vlist) { 325 if (!br_vlan_should_use(v)) 326 continue; 327 f = br_fdb_find(br, br->dev->dev_addr, v->vid); 328 if (f && test_bit(BR_FDB_LOCAL, &f->flags) && 329 !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) 330 fdb_delete_local(br, NULL, f); 331 fdb_insert(br, NULL, newaddr, v->vid); 332 } 333 out: 334 spin_unlock_bh(&br->hash_lock); 335 } 336 337 void br_fdb_cleanup(struct work_struct *work) 338 { 339 struct net_bridge *br = container_of(work, struct net_bridge, 340 gc_work.work); 341 struct net_bridge_fdb_entry *f = NULL; 342 unsigned long delay = hold_time(br); 343 unsigned long work_delay = delay; 344 unsigned long now = jiffies; 345 346 /* this part is tricky, in order to avoid blocking learning and 347 * consequently forwarding, we rely on rcu to delete objects with 348 * delayed freeing allowing us to continue traversing 349 */ 350 rcu_read_lock(); 351 hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { 352 unsigned long this_timer = f->updated + delay; 353 354 if (test_bit(BR_FDB_STATIC, &f->flags) || 355 test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags)) { 356 if (test_bit(BR_FDB_NOTIFY, &f->flags)) { 357 if (time_after(this_timer, now)) 358 work_delay = min(work_delay, 359 this_timer - now); 360 else if (!test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, 361 &f->flags)) 362 fdb_notify(br, f, RTM_NEWNEIGH, false); 363 } 364 continue; 365 } 366 367 if (time_after(this_timer, now)) { 368 work_delay = min(work_delay, this_timer - now); 369 } else { 370 spin_lock_bh(&br->hash_lock); 371 if (!hlist_unhashed(&f->fdb_node)) 372 fdb_delete(br, f, true); 373 spin_unlock_bh(&br->hash_lock); 374 } 375 } 376 rcu_read_unlock(); 377 378 /* Cleanup minimum 10 milliseconds apart */ 379 work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10)); 380 mod_delayed_work(system_long_wq, &br->gc_work, work_delay); 381 } 382 383 /* Completely flush all dynamic entries in forwarding database.*/ 384 void br_fdb_flush(struct net_bridge *br) 385 { 386 struct net_bridge_fdb_entry *f; 387 struct hlist_node *tmp; 388 389 spin_lock_bh(&br->hash_lock); 390 hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) { 391 if (!test_bit(BR_FDB_STATIC, &f->flags)) 392 fdb_delete(br, f, true); 393 } 394 spin_unlock_bh(&br->hash_lock); 395 } 396 397 /* Flush all entries referring to a specific port. 398 * if do_all is set also flush static entries 399 * if vid is set delete all entries that match the vlan_id 400 */ 401 void br_fdb_delete_by_port(struct net_bridge *br, 402 const struct net_bridge_port *p, 403 u16 vid, 404 int do_all) 405 { 406 struct net_bridge_fdb_entry *f; 407 struct hlist_node *tmp; 408 409 spin_lock_bh(&br->hash_lock); 410 hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) { 411 if (f->dst != p) 412 continue; 413 414 if (!do_all) 415 if (test_bit(BR_FDB_STATIC, &f->flags) || 416 (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags) && 417 !test_bit(BR_FDB_OFFLOADED, &f->flags)) || 418 (vid && f->key.vlan_id != vid)) 419 continue; 420 421 if (test_bit(BR_FDB_LOCAL, &f->flags)) 422 fdb_delete_local(br, p, f); 423 else 424 fdb_delete(br, f, true); 425 } 426 spin_unlock_bh(&br->hash_lock); 427 } 428 429 #if IS_ENABLED(CONFIG_ATM_LANE) 430 /* Interface used by ATM LANE hook to test 431 * if an addr is on some other bridge port */ 432 int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) 433 { 434 struct net_bridge_fdb_entry *fdb; 435 struct net_bridge_port *port; 436 int ret; 437 438 rcu_read_lock(); 439 port = br_port_get_rcu(dev); 440 if (!port) 441 ret = 0; 442 else { 443 fdb = br_fdb_find_rcu(port->br, addr, 0); 444 ret = fdb && fdb->dst && fdb->dst->dev != dev && 445 fdb->dst->state == BR_STATE_FORWARDING; 446 } 447 rcu_read_unlock(); 448 449 return ret; 450 } 451 #endif /* CONFIG_ATM_LANE */ 452 453 /* 454 * Fill buffer with forwarding table records in 455 * the API format. 456 */ 457 int br_fdb_fillbuf(struct net_bridge *br, void *buf, 458 unsigned long maxnum, unsigned long skip) 459 { 460 struct net_bridge_fdb_entry *f; 461 struct __fdb_entry *fe = buf; 462 int num = 0; 463 464 memset(buf, 0, maxnum*sizeof(struct __fdb_entry)); 465 466 rcu_read_lock(); 467 hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { 468 if (num >= maxnum) 469 break; 470 471 if (has_expired(br, f)) 472 continue; 473 474 /* ignore pseudo entry for local MAC address */ 475 if (!f->dst) 476 continue; 477 478 if (skip) { 479 --skip; 480 continue; 481 } 482 483 /* convert from internal format to API */ 484 memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN); 485 486 /* due to ABI compat need to split into hi/lo */ 487 fe->port_no = f->dst->port_no; 488 fe->port_hi = f->dst->port_no >> 8; 489 490 fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags); 491 if (!test_bit(BR_FDB_STATIC, &f->flags)) 492 fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated); 493 ++fe; 494 ++num; 495 } 496 rcu_read_unlock(); 497 498 return num; 499 } 500 501 static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br, 502 struct net_bridge_port *source, 503 const unsigned char *addr, 504 __u16 vid, 505 unsigned long flags) 506 { 507 struct net_bridge_fdb_entry *fdb; 508 509 fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); 510 if (fdb) { 511 memcpy(fdb->key.addr.addr, addr, ETH_ALEN); 512 fdb->dst = source; 513 fdb->key.vlan_id = vid; 514 fdb->flags = flags; 515 fdb->updated = fdb->used = jiffies; 516 if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, 517 &fdb->rhnode, 518 br_fdb_rht_params)) { 519 kmem_cache_free(br_fdb_cache, fdb); 520 fdb = NULL; 521 } else { 522 hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list); 523 } 524 } 525 return fdb; 526 } 527 528 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, 529 const unsigned char *addr, u16 vid) 530 { 531 struct net_bridge_fdb_entry *fdb; 532 533 if (!is_valid_ether_addr(addr)) 534 return -EINVAL; 535 536 fdb = br_fdb_find(br, addr, vid); 537 if (fdb) { 538 /* it is okay to have multiple ports with same 539 * address, just use the first one. 540 */ 541 if (test_bit(BR_FDB_LOCAL, &fdb->flags)) 542 return 0; 543 br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n", 544 source ? source->dev->name : br->dev->name, addr, vid); 545 fdb_delete(br, fdb, true); 546 } 547 548 fdb = fdb_create(br, source, addr, vid, 549 BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC)); 550 if (!fdb) 551 return -ENOMEM; 552 553 fdb_add_hw_addr(br, addr); 554 fdb_notify(br, fdb, RTM_NEWNEIGH, true); 555 return 0; 556 } 557 558 /* Add entry for local address of interface */ 559 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source, 560 const unsigned char *addr, u16 vid) 561 { 562 int ret; 563 564 spin_lock_bh(&br->hash_lock); 565 ret = fdb_insert(br, source, addr, vid); 566 spin_unlock_bh(&br->hash_lock); 567 return ret; 568 } 569 570 /* returns true if the fdb was modified */ 571 static bool __fdb_mark_active(struct net_bridge_fdb_entry *fdb) 572 { 573 return !!(test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags) && 574 test_and_clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)); 575 } 576 577 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, 578 const unsigned char *addr, u16 vid, unsigned long flags) 579 { 580 struct net_bridge_fdb_entry *fdb; 581 582 /* some users want to always flood. */ 583 if (hold_time(br) == 0) 584 return; 585 586 fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); 587 if (likely(fdb)) { 588 /* attempt to update an entry for a local interface */ 589 if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) { 590 if (net_ratelimit()) 591 br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n", 592 source->dev->name, addr, vid); 593 } else { 594 unsigned long now = jiffies; 595 bool fdb_modified = false; 596 597 if (now != fdb->updated) { 598 fdb->updated = now; 599 fdb_modified = __fdb_mark_active(fdb); 600 } 601 602 /* fastpath: update of existing entry */ 603 if (unlikely(source != fdb->dst && 604 !test_bit(BR_FDB_STICKY, &fdb->flags))) { 605 fdb->dst = source; 606 fdb_modified = true; 607 /* Take over HW learned entry */ 608 if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN, 609 &fdb->flags))) 610 clear_bit(BR_FDB_ADDED_BY_EXT_LEARN, 611 &fdb->flags); 612 } 613 614 if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags))) 615 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); 616 if (unlikely(fdb_modified)) { 617 trace_br_fdb_update(br, source, addr, vid, flags); 618 fdb_notify(br, fdb, RTM_NEWNEIGH, true); 619 } 620 } 621 } else { 622 spin_lock(&br->hash_lock); 623 fdb = fdb_create(br, source, addr, vid, flags); 624 if (fdb) { 625 trace_br_fdb_update(br, source, addr, vid, flags); 626 fdb_notify(br, fdb, RTM_NEWNEIGH, true); 627 } 628 /* else we lose race and someone else inserts 629 * it first, don't bother updating 630 */ 631 spin_unlock(&br->hash_lock); 632 } 633 } 634 635 static int fdb_to_nud(const struct net_bridge *br, 636 const struct net_bridge_fdb_entry *fdb) 637 { 638 if (test_bit(BR_FDB_LOCAL, &fdb->flags)) 639 return NUD_PERMANENT; 640 else if (test_bit(BR_FDB_STATIC, &fdb->flags)) 641 return NUD_NOARP; 642 else if (has_expired(br, fdb)) 643 return NUD_STALE; 644 else 645 return NUD_REACHABLE; 646 } 647 648 static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br, 649 const struct net_bridge_fdb_entry *fdb, 650 u32 portid, u32 seq, int type, unsigned int flags) 651 { 652 unsigned long now = jiffies; 653 struct nda_cacheinfo ci; 654 struct nlmsghdr *nlh; 655 struct ndmsg *ndm; 656 657 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags); 658 if (nlh == NULL) 659 return -EMSGSIZE; 660 661 ndm = nlmsg_data(nlh); 662 ndm->ndm_family = AF_BRIDGE; 663 ndm->ndm_pad1 = 0; 664 ndm->ndm_pad2 = 0; 665 ndm->ndm_flags = 0; 666 ndm->ndm_type = 0; 667 ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex; 668 ndm->ndm_state = fdb_to_nud(br, fdb); 669 670 if (test_bit(BR_FDB_OFFLOADED, &fdb->flags)) 671 ndm->ndm_flags |= NTF_OFFLOADED; 672 if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) 673 ndm->ndm_flags |= NTF_EXT_LEARNED; 674 if (test_bit(BR_FDB_STICKY, &fdb->flags)) 675 ndm->ndm_flags |= NTF_STICKY; 676 677 if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr)) 678 goto nla_put_failure; 679 if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex)) 680 goto nla_put_failure; 681 ci.ndm_used = jiffies_to_clock_t(now - fdb->used); 682 ci.ndm_confirmed = 0; 683 ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated); 684 ci.ndm_refcnt = 0; 685 if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci)) 686 goto nla_put_failure; 687 688 if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), 689 &fdb->key.vlan_id)) 690 goto nla_put_failure; 691 692 if (test_bit(BR_FDB_NOTIFY, &fdb->flags)) { 693 struct nlattr *nest = nla_nest_start(skb, NDA_FDB_EXT_ATTRS); 694 u8 notify_bits = FDB_NOTIFY_BIT; 695 696 if (!nest) 697 goto nla_put_failure; 698 if (test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)) 699 notify_bits |= FDB_NOTIFY_INACTIVE_BIT; 700 701 if (nla_put_u8(skb, NFEA_ACTIVITY_NOTIFY, notify_bits)) { 702 nla_nest_cancel(skb, nest); 703 goto nla_put_failure; 704 } 705 706 nla_nest_end(skb, nest); 707 } 708 709 nlmsg_end(skb, nlh); 710 return 0; 711 712 nla_put_failure: 713 nlmsg_cancel(skb, nlh); 714 return -EMSGSIZE; 715 } 716 717 static inline size_t fdb_nlmsg_size(void) 718 { 719 return NLMSG_ALIGN(sizeof(struct ndmsg)) 720 + nla_total_size(ETH_ALEN) /* NDA_LLADDR */ 721 + nla_total_size(sizeof(u32)) /* NDA_MASTER */ 722 + nla_total_size(sizeof(u16)) /* NDA_VLAN */ 723 + nla_total_size(sizeof(struct nda_cacheinfo)) 724 + nla_total_size(0) /* NDA_FDB_EXT_ATTRS */ 725 + nla_total_size(sizeof(u8)); /* NFEA_ACTIVITY_NOTIFY */ 726 } 727 728 static void fdb_notify(struct net_bridge *br, 729 const struct net_bridge_fdb_entry *fdb, int type, 730 bool swdev_notify) 731 { 732 struct net *net = dev_net(br->dev); 733 struct sk_buff *skb; 734 int err = -ENOBUFS; 735 736 if (swdev_notify) 737 br_switchdev_fdb_notify(fdb, type); 738 739 skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC); 740 if (skb == NULL) 741 goto errout; 742 743 err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0); 744 if (err < 0) { 745 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */ 746 WARN_ON(err == -EMSGSIZE); 747 kfree_skb(skb); 748 goto errout; 749 } 750 rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC); 751 return; 752 errout: 753 rtnl_set_sk_err(net, RTNLGRP_NEIGH, err); 754 } 755 756 /* Dump information about entries, in response to GETNEIGH */ 757 int br_fdb_dump(struct sk_buff *skb, 758 struct netlink_callback *cb, 759 struct net_device *dev, 760 struct net_device *filter_dev, 761 int *idx) 762 { 763 struct net_bridge *br = netdev_priv(dev); 764 struct net_bridge_fdb_entry *f; 765 int err = 0; 766 767 if (!(dev->priv_flags & IFF_EBRIDGE)) 768 return err; 769 770 if (!filter_dev) { 771 err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx); 772 if (err < 0) 773 return err; 774 } 775 776 rcu_read_lock(); 777 hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { 778 if (*idx < cb->args[2]) 779 goto skip; 780 if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) { 781 if (filter_dev != dev) 782 goto skip; 783 /* !f->dst is a special case for bridge 784 * It means the MAC belongs to the bridge 785 * Therefore need a little more filtering 786 * we only want to dump the !f->dst case 787 */ 788 if (f->dst) 789 goto skip; 790 } 791 if (!filter_dev && f->dst) 792 goto skip; 793 794 err = fdb_fill_info(skb, br, f, 795 NETLINK_CB(cb->skb).portid, 796 cb->nlh->nlmsg_seq, 797 RTM_NEWNEIGH, 798 NLM_F_MULTI); 799 if (err < 0) 800 break; 801 skip: 802 *idx += 1; 803 } 804 rcu_read_unlock(); 805 806 return err; 807 } 808 809 int br_fdb_get(struct sk_buff *skb, 810 struct nlattr *tb[], 811 struct net_device *dev, 812 const unsigned char *addr, 813 u16 vid, u32 portid, u32 seq, 814 struct netlink_ext_ack *extack) 815 { 816 struct net_bridge *br = netdev_priv(dev); 817 struct net_bridge_fdb_entry *f; 818 int err = 0; 819 820 rcu_read_lock(); 821 f = br_fdb_find_rcu(br, addr, vid); 822 if (!f) { 823 NL_SET_ERR_MSG(extack, "Fdb entry not found"); 824 err = -ENOENT; 825 goto errout; 826 } 827 828 err = fdb_fill_info(skb, br, f, portid, seq, 829 RTM_NEWNEIGH, 0); 830 errout: 831 rcu_read_unlock(); 832 return err; 833 } 834 835 /* returns true if the fdb is modified */ 836 static bool fdb_handle_notify(struct net_bridge_fdb_entry *fdb, u8 notify) 837 { 838 bool modified = false; 839 840 /* allow to mark an entry as inactive, usually done on creation */ 841 if ((notify & FDB_NOTIFY_INACTIVE_BIT) && 842 !test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)) 843 modified = true; 844 845 if ((notify & FDB_NOTIFY_BIT) && 846 !test_and_set_bit(BR_FDB_NOTIFY, &fdb->flags)) { 847 /* enabled activity tracking */ 848 modified = true; 849 } else if (!(notify & FDB_NOTIFY_BIT) && 850 test_and_clear_bit(BR_FDB_NOTIFY, &fdb->flags)) { 851 /* disabled activity tracking, clear notify state */ 852 clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags); 853 modified = true; 854 } 855 856 return modified; 857 } 858 859 /* Update (create or replace) forwarding database entry */ 860 static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, 861 const u8 *addr, struct ndmsg *ndm, u16 flags, u16 vid, 862 struct nlattr *nfea_tb[]) 863 { 864 bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY); 865 bool refresh = !nfea_tb[NFEA_DONT_REFRESH]; 866 struct net_bridge_fdb_entry *fdb; 867 u16 state = ndm->ndm_state; 868 bool modified = false; 869 u8 notify = 0; 870 871 /* If the port cannot learn allow only local and static entries */ 872 if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) && 873 !(source->state == BR_STATE_LEARNING || 874 source->state == BR_STATE_FORWARDING)) 875 return -EPERM; 876 877 if (!source && !(state & NUD_PERMANENT)) { 878 pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n", 879 br->dev->name); 880 return -EINVAL; 881 } 882 883 if (is_sticky && (state & NUD_PERMANENT)) 884 return -EINVAL; 885 886 if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) { 887 notify = nla_get_u8(nfea_tb[NFEA_ACTIVITY_NOTIFY]); 888 if ((notify & ~BR_FDB_NOTIFY_SETTABLE_BITS) || 889 (notify & BR_FDB_NOTIFY_SETTABLE_BITS) == FDB_NOTIFY_INACTIVE_BIT) 890 return -EINVAL; 891 } 892 893 fdb = br_fdb_find(br, addr, vid); 894 if (fdb == NULL) { 895 if (!(flags & NLM_F_CREATE)) 896 return -ENOENT; 897 898 fdb = fdb_create(br, source, addr, vid, 0); 899 if (!fdb) 900 return -ENOMEM; 901 902 modified = true; 903 } else { 904 if (flags & NLM_F_EXCL) 905 return -EEXIST; 906 907 if (fdb->dst != source) { 908 fdb->dst = source; 909 modified = true; 910 } 911 } 912 913 if (fdb_to_nud(br, fdb) != state) { 914 if (state & NUD_PERMANENT) { 915 set_bit(BR_FDB_LOCAL, &fdb->flags); 916 if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags)) 917 fdb_add_hw_addr(br, addr); 918 } else if (state & NUD_NOARP) { 919 clear_bit(BR_FDB_LOCAL, &fdb->flags); 920 if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags)) 921 fdb_add_hw_addr(br, addr); 922 } else { 923 clear_bit(BR_FDB_LOCAL, &fdb->flags); 924 if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags)) 925 fdb_del_hw_addr(br, addr); 926 } 927 928 modified = true; 929 } 930 931 if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) { 932 change_bit(BR_FDB_STICKY, &fdb->flags); 933 modified = true; 934 } 935 936 if (fdb_handle_notify(fdb, notify)) 937 modified = true; 938 939 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); 940 941 fdb->used = jiffies; 942 if (modified) { 943 if (refresh) 944 fdb->updated = jiffies; 945 fdb_notify(br, fdb, RTM_NEWNEIGH, true); 946 } 947 948 return 0; 949 } 950 951 static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br, 952 struct net_bridge_port *p, const unsigned char *addr, 953 u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[]) 954 { 955 int err = 0; 956 957 if (ndm->ndm_flags & NTF_USE) { 958 if (!p) { 959 pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n", 960 br->dev->name); 961 return -EINVAL; 962 } 963 if (!nbp_state_should_learn(p)) 964 return 0; 965 966 local_bh_disable(); 967 rcu_read_lock(); 968 br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER)); 969 rcu_read_unlock(); 970 local_bh_enable(); 971 } else if (ndm->ndm_flags & NTF_EXT_LEARNED) { 972 err = br_fdb_external_learn_add(br, p, addr, vid, true); 973 } else { 974 spin_lock_bh(&br->hash_lock); 975 err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb); 976 spin_unlock_bh(&br->hash_lock); 977 } 978 979 return err; 980 } 981 982 static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = { 983 [NFEA_ACTIVITY_NOTIFY] = { .type = NLA_U8 }, 984 [NFEA_DONT_REFRESH] = { .type = NLA_FLAG }, 985 }; 986 987 /* Add new permanent fdb entry with RTM_NEWNEIGH */ 988 int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], 989 struct net_device *dev, 990 const unsigned char *addr, u16 vid, u16 nlh_flags, 991 struct netlink_ext_ack *extack) 992 { 993 struct nlattr *nfea_tb[NFEA_MAX + 1], *attr; 994 struct net_bridge_vlan_group *vg; 995 struct net_bridge_port *p = NULL; 996 struct net_bridge_vlan *v; 997 struct net_bridge *br = NULL; 998 int err = 0; 999 1000 trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags); 1001 1002 if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) { 1003 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state); 1004 return -EINVAL; 1005 } 1006 1007 if (is_zero_ether_addr(addr)) { 1008 pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n"); 1009 return -EINVAL; 1010 } 1011 1012 if (dev->priv_flags & IFF_EBRIDGE) { 1013 br = netdev_priv(dev); 1014 vg = br_vlan_group(br); 1015 } else { 1016 p = br_port_get_rtnl(dev); 1017 if (!p) { 1018 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n", 1019 dev->name); 1020 return -EINVAL; 1021 } 1022 br = p->br; 1023 vg = nbp_vlan_group(p); 1024 } 1025 1026 if (tb[NDA_FDB_EXT_ATTRS]) { 1027 attr = tb[NDA_FDB_EXT_ATTRS]; 1028 err = nla_parse_nested(nfea_tb, NFEA_MAX, attr, 1029 br_nda_fdb_pol, extack); 1030 if (err) 1031 return err; 1032 } else { 1033 memset(nfea_tb, 0, sizeof(struct nlattr *) * (NFEA_MAX + 1)); 1034 } 1035 1036 if (vid) { 1037 v = br_vlan_find(vg, vid); 1038 if (!v || !br_vlan_should_use(v)) { 1039 pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name); 1040 return -EINVAL; 1041 } 1042 1043 /* VID was specified, so use it. */ 1044 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb); 1045 } else { 1046 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb); 1047 if (err || !vg || !vg->num_vlans) 1048 goto out; 1049 1050 /* We have vlans configured on this port and user didn't 1051 * specify a VLAN. To be nice, add/update entry for every 1052 * vlan on this port. 1053 */ 1054 list_for_each_entry(v, &vg->vlan_list, vlist) { 1055 if (!br_vlan_should_use(v)) 1056 continue; 1057 err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid, 1058 nfea_tb); 1059 if (err) 1060 goto out; 1061 } 1062 } 1063 1064 out: 1065 return err; 1066 } 1067 1068 static int fdb_delete_by_addr_and_port(struct net_bridge *br, 1069 const struct net_bridge_port *p, 1070 const u8 *addr, u16 vlan) 1071 { 1072 struct net_bridge_fdb_entry *fdb; 1073 1074 fdb = br_fdb_find(br, addr, vlan); 1075 if (!fdb || fdb->dst != p) 1076 return -ENOENT; 1077 1078 fdb_delete(br, fdb, true); 1079 1080 return 0; 1081 } 1082 1083 static int __br_fdb_delete(struct net_bridge *br, 1084 const struct net_bridge_port *p, 1085 const unsigned char *addr, u16 vid) 1086 { 1087 int err; 1088 1089 spin_lock_bh(&br->hash_lock); 1090 err = fdb_delete_by_addr_and_port(br, p, addr, vid); 1091 spin_unlock_bh(&br->hash_lock); 1092 1093 return err; 1094 } 1095 1096 /* Remove neighbor entry with RTM_DELNEIGH */ 1097 int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[], 1098 struct net_device *dev, 1099 const unsigned char *addr, u16 vid) 1100 { 1101 struct net_bridge_vlan_group *vg; 1102 struct net_bridge_port *p = NULL; 1103 struct net_bridge_vlan *v; 1104 struct net_bridge *br; 1105 int err; 1106 1107 if (dev->priv_flags & IFF_EBRIDGE) { 1108 br = netdev_priv(dev); 1109 vg = br_vlan_group(br); 1110 } else { 1111 p = br_port_get_rtnl(dev); 1112 if (!p) { 1113 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n", 1114 dev->name); 1115 return -EINVAL; 1116 } 1117 vg = nbp_vlan_group(p); 1118 br = p->br; 1119 } 1120 1121 if (vid) { 1122 v = br_vlan_find(vg, vid); 1123 if (!v) { 1124 pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name); 1125 return -EINVAL; 1126 } 1127 1128 err = __br_fdb_delete(br, p, addr, vid); 1129 } else { 1130 err = -ENOENT; 1131 err &= __br_fdb_delete(br, p, addr, 0); 1132 if (!vg || !vg->num_vlans) 1133 return err; 1134 1135 list_for_each_entry(v, &vg->vlan_list, vlist) { 1136 if (!br_vlan_should_use(v)) 1137 continue; 1138 err &= __br_fdb_delete(br, p, addr, v->vid); 1139 } 1140 } 1141 1142 return err; 1143 } 1144 1145 int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p) 1146 { 1147 struct net_bridge_fdb_entry *f, *tmp; 1148 int err = 0; 1149 1150 ASSERT_RTNL(); 1151 1152 /* the key here is that static entries change only under rtnl */ 1153 rcu_read_lock(); 1154 hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { 1155 /* We only care for static entries */ 1156 if (!test_bit(BR_FDB_STATIC, &f->flags)) 1157 continue; 1158 err = dev_uc_add(p->dev, f->key.addr.addr); 1159 if (err) 1160 goto rollback; 1161 } 1162 done: 1163 rcu_read_unlock(); 1164 1165 return err; 1166 1167 rollback: 1168 hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) { 1169 /* We only care for static entries */ 1170 if (!test_bit(BR_FDB_STATIC, &tmp->flags)) 1171 continue; 1172 if (tmp == f) 1173 break; 1174 dev_uc_del(p->dev, tmp->key.addr.addr); 1175 } 1176 1177 goto done; 1178 } 1179 1180 void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p) 1181 { 1182 struct net_bridge_fdb_entry *f; 1183 1184 ASSERT_RTNL(); 1185 1186 rcu_read_lock(); 1187 hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { 1188 /* We only care for static entries */ 1189 if (!test_bit(BR_FDB_STATIC, &f->flags)) 1190 continue; 1191 1192 dev_uc_del(p->dev, f->key.addr.addr); 1193 } 1194 rcu_read_unlock(); 1195 } 1196 1197 int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, 1198 const unsigned char *addr, u16 vid, 1199 bool swdev_notify) 1200 { 1201 struct net_bridge_fdb_entry *fdb; 1202 bool modified = false; 1203 int err = 0; 1204 1205 trace_br_fdb_external_learn_add(br, p, addr, vid); 1206 1207 spin_lock_bh(&br->hash_lock); 1208 1209 fdb = br_fdb_find(br, addr, vid); 1210 if (!fdb) { 1211 unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN); 1212 1213 if (swdev_notify) 1214 flags |= BIT(BR_FDB_ADDED_BY_USER); 1215 fdb = fdb_create(br, p, addr, vid, flags); 1216 if (!fdb) { 1217 err = -ENOMEM; 1218 goto err_unlock; 1219 } 1220 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify); 1221 } else { 1222 fdb->updated = jiffies; 1223 1224 if (fdb->dst != p) { 1225 fdb->dst = p; 1226 modified = true; 1227 } 1228 1229 if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) { 1230 /* Refresh entry */ 1231 fdb->used = jiffies; 1232 } else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) { 1233 /* Take over SW learned entry */ 1234 set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags); 1235 modified = true; 1236 } 1237 1238 if (swdev_notify) 1239 set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); 1240 1241 if (modified) 1242 fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify); 1243 } 1244 1245 err_unlock: 1246 spin_unlock_bh(&br->hash_lock); 1247 1248 return err; 1249 } 1250 1251 int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p, 1252 const unsigned char *addr, u16 vid, 1253 bool swdev_notify) 1254 { 1255 struct net_bridge_fdb_entry *fdb; 1256 int err = 0; 1257 1258 spin_lock_bh(&br->hash_lock); 1259 1260 fdb = br_fdb_find(br, addr, vid); 1261 if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) 1262 fdb_delete(br, fdb, swdev_notify); 1263 else 1264 err = -ENOENT; 1265 1266 spin_unlock_bh(&br->hash_lock); 1267 1268 return err; 1269 } 1270 1271 void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p, 1272 const unsigned char *addr, u16 vid, bool offloaded) 1273 { 1274 struct net_bridge_fdb_entry *fdb; 1275 1276 spin_lock_bh(&br->hash_lock); 1277 1278 fdb = br_fdb_find(br, addr, vid); 1279 if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags)) 1280 change_bit(BR_FDB_OFFLOADED, &fdb->flags); 1281 1282 spin_unlock_bh(&br->hash_lock); 1283 } 1284 1285 void br_fdb_clear_offload(const struct net_device *dev, u16 vid) 1286 { 1287 struct net_bridge_fdb_entry *f; 1288 struct net_bridge_port *p; 1289 1290 ASSERT_RTNL(); 1291 1292 p = br_port_get_rtnl(dev); 1293 if (!p) 1294 return; 1295 1296 spin_lock_bh(&p->br->hash_lock); 1297 hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) { 1298 if (f->dst == p && f->key.vlan_id == vid) 1299 clear_bit(BR_FDB_OFFLOADED, &f->flags); 1300 } 1301 spin_unlock_bh(&p->br->hash_lock); 1302 } 1303 EXPORT_SYMBOL_GPL(br_fdb_clear_offload); 1304