LXR linux/net/bridge/br

   1/*
   2 *      Forwarding database
   3 *      Linux ethernet bridge
   4 *
   5 *      Authors:
   6 *      Lennert Buytenhek               <buytenh@gnu.org>
   7 *
   8 *      This program is free software; you can redistribute it and/or
   9 *      modify it under the terms of the GNU General Public License
  10 *      as published by the Free Software Foundation; either version
  11 *      2 of the License, or (at your option) any later version.
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/init.h>
  16#include <linux/rculist.h>
  17#include <linux/spinlock.h>
  18#include <linux/times.h>
  19#include <linux/netdevice.h>
  20#include <linux/etherdevice.h>
  21#include <linux/jhash.h>
  22#include <linux/random.h>
  23#include <linux/slab.h>
  24#include <linux/atomic.h>
  25#include <asm/unaligned.h>
  26#include <linux/if_vlan.h>
  27#include <net/switchdev.h>
  28#include <trace/events/bridge.h>
  29#include "br_private.h"
  30
  31static struct kmem_cache *br_fdb_cache __read_mostly;
  32static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  33                      const unsigned char *addr, u16 vid);
  34static void fdb_notify(struct net_bridge *br,
  35                       const struct net_bridge_fdb_entry *, int);
  36
  37static u32 fdb_salt __read_mostly;
  38
  39int __init br_fdb_init(void)
  40{
  41        br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  42                                         sizeof(struct net_bridge_fdb_entry),
  43                                         0,
  44                                         SLAB_HWCACHE_ALIGN, NULL);
  45        if (!br_fdb_cache)
  46                return -ENOMEM;
  47
  48        get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  49        return 0;
  50}
  51
  52void br_fdb_fini(void)
  53{
  54        kmem_cache_destroy(br_fdb_cache);
  55}
  56
  57
  58/* if topology_changing then use forward_delay (default 15 sec)
  59 * otherwise keep longer (default 5 minutes)
  60 */
  61static inline unsigned long hold_time(const struct net_bridge *br)
  62{
  63        return br->topology_change ? br->forward_delay : br->ageing_time;
  64}
  65
  66static inline int has_expired(const struct net_bridge *br,
  67                                  const struct net_bridge_fdb_entry *fdb)
  68{
  69        return !fdb->is_static && !fdb->added_by_external_learn &&
  70                time_before_eq(fdb->updated + hold_time(br), jiffies);
  71}
  72
  73static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  74{
  75        /* use 1 byte of OUI and 3 bytes of NIC */
  76        u32 key = get_unaligned((u32 *)(mac + 2));
  77        return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  78}
  79
  80static void fdb_rcu_free(struct rcu_head *head)
  81{
  82        struct net_bridge_fdb_entry *ent
  83                = container_of(head, struct net_bridge_fdb_entry, rcu);
  84        kmem_cache_free(br_fdb_cache, ent);
  85}
  86
  87static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
  88                                                 const unsigned char *addr,
  89                                                 __u16 vid)
  90{
  91        struct net_bridge_fdb_entry *f;
  92
  93        WARN_ON_ONCE(!rcu_read_lock_held());
  94
  95        hlist_for_each_entry_rcu(f, head, hlist)
  96                if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid)
  97                        break;
  98
  99        return f;
 100}
 101
 102/* requires bridge hash_lock */
 103static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
 104                                                const unsigned char *addr,
 105                                                __u16 vid)
 106{
 107        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 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(head, addr, vid);
 114        rcu_read_unlock();
 115
 116        return fdb;
 117}
 118
 119struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
 120                                             const unsigned char *addr,
 121                                             __u16 vid)
 122{
 123        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 124
 125        return fdb_find_rcu(head, addr, vid);
 126}
 127
 128/* When a static FDB entry is added, the mac address from the entry is
 129 * added to the bridge private HW address list and all required ports
 130 * are then updated with the new information.
 131 * Called under RTNL.
 132 */
 133static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
 134{
 135        int err;
 136        struct net_bridge_port *p;
 137
 138        ASSERT_RTNL();
 139
 140        list_for_each_entry(p, &br->port_list, list) {
 141                if (!br_promisc_port(p)) {
 142                        err = dev_uc_add(p->dev, addr);
 143                        if (err)
 144                                goto undo;
 145                }
 146        }
 147
 148        return;
 149undo:
 150        list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 151                if (!br_promisc_port(p))
 152                        dev_uc_del(p->dev, addr);
 153        }
 154}
 155
 156/* When a static FDB entry is deleted, the HW address from that entry is
 157 * also removed from the bridge private HW address list and updates all
 158 * the ports with needed information.
 159 * Called under RTNL.
 160 */
 161static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 162{
 163        struct net_bridge_port *p;
 164
 165        ASSERT_RTNL();
 166
 167        list_for_each_entry(p, &br->port_list, list) {
 168                if (!br_promisc_port(p))
 169                        dev_uc_del(p->dev, addr);
 170        }
 171}
 172
 173static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 174{
 175        trace_fdb_delete(br, f);
 176
 177        if (f->is_static)
 178                fdb_del_hw_addr(br, f->addr.addr);
 179
 180        hlist_del_init_rcu(&f->hlist);
 181        fdb_notify(br, f, RTM_DELNEIGH);
 182        call_rcu(&f->rcu, fdb_rcu_free);
 183}
 184
 185/* Delete a local entry if no other port had the same address. */
 186static void fdb_delete_local(struct net_bridge *br,
 187                             const struct net_bridge_port *p,
 188                             struct net_bridge_fdb_entry *f)
 189{
 190        const unsigned char *addr = f->addr.addr;
 191        struct net_bridge_vlan_group *vg;
 192        const struct net_bridge_vlan *v;
 193        struct net_bridge_port *op;
 194        u16 vid = f->vlan_id;
 195
 196        /* Maybe another port has same hw addr? */
 197        list_for_each_entry(op, &br->port_list, list) {
 198                vg = nbp_vlan_group(op);
 199                if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 200                    (!vid || br_vlan_find(vg, vid))) {
 201                        f->dst = op;
 202                        f->added_by_user = 0;
 203                        return;
 204                }
 205        }
 206
 207        vg = br_vlan_group(br);
 208        v = br_vlan_find(vg, vid);
 209        /* Maybe bridge device has same hw addr? */
 210        if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 211            (!vid || (v && br_vlan_should_use(v)))) {
 212                f->dst = NULL;
 213                f->added_by_user = 0;
 214                return;
 215        }
 216
 217        fdb_delete(br, f);
 218}
 219
 220void br_fdb_find_delete_local(struct net_bridge *br,
 221                              const struct net_bridge_port *p,
 222                              const unsigned char *addr, u16 vid)
 223{
 224        struct net_bridge_fdb_entry *f;
 225
 226        spin_lock_bh(&br->hash_lock);
 227        f = br_fdb_find(br, addr, vid);
 228        if (f && f->is_local && !f->added_by_user && f->dst == p)
 229                fdb_delete_local(br, p, f);
 230        spin_unlock_bh(&br->hash_lock);
 231}
 232
 233void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 234{
 235        struct net_bridge_vlan_group *vg;
 236        struct net_bridge *br = p->br;
 237        struct net_bridge_vlan *v;
 238        int i;
 239
 240        spin_lock_bh(&br->hash_lock);
 241
 242        vg = nbp_vlan_group(p);
 243        /* Search all chains since old address/hash is unknown */
 244        for (i = 0; i < BR_HASH_SIZE; i++) {
 245                struct hlist_node *h;
 246                hlist_for_each(h, &br->hash[i]) {
 247                        struct net_bridge_fdb_entry *f;
 248
 249                        f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 250                        if (f->dst == p && f->is_local && !f->added_by_user) {
 251                                /* delete old one */
 252                                fdb_delete_local(br, p, f);
 253
 254                                /* if this port has no vlan information
 255                                 * configured, we can safely be done at
 256                                 * this point.
 257                                 */
 258                                if (!vg || !vg->num_vlans)
 259                                        goto insert;
 260                        }
 261                }
 262        }
 263
 264insert:
 265        /* insert new address,  may fail if invalid address or dup. */
 266        fdb_insert(br, p, newaddr, 0);
 267
 268        if (!vg || !vg->num_vlans)
 269                goto done;
 270
 271        /* Now add entries for every VLAN configured on the port.
 272         * This function runs under RTNL so the bitmap will not change
 273         * from under us.
 274         */
 275        list_for_each_entry(v, &vg->vlan_list, vlist)
 276                fdb_insert(br, p, newaddr, v->vid);
 277
 278done:
 279        spin_unlock_bh(&br->hash_lock);
 280}
 281
 282void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 283{
 284        struct net_bridge_vlan_group *vg;
 285        struct net_bridge_fdb_entry *f;
 286        struct net_bridge_vlan *v;
 287
 288        spin_lock_bh(&br->hash_lock);
 289
 290        /* If old entry was unassociated with any port, then delete it. */
 291        f = br_fdb_find(br, br->dev->dev_addr, 0);
 292        if (f && f->is_local && !f->dst && !f->added_by_user)
 293                fdb_delete_local(br, NULL, f);
 294
 295        fdb_insert(br, NULL, newaddr, 0);
 296        vg = br_vlan_group(br);
 297        if (!vg || !vg->num_vlans)
 298                goto out;
 299        /* Now remove and add entries for every VLAN configured on the
 300         * bridge.  This function runs under RTNL so the bitmap will not
 301         * change from under us.
 302         */
 303        list_for_each_entry(v, &vg->vlan_list, vlist) {
 304                if (!br_vlan_should_use(v))
 305                        continue;
 306                f = br_fdb_find(br, br->dev->dev_addr, v->vid);
 307                if (f && f->is_local && !f->dst && !f->added_by_user)
 308                        fdb_delete_local(br, NULL, f);
 309                fdb_insert(br, NULL, newaddr, v->vid);
 310        }
 311out:
 312        spin_unlock_bh(&br->hash_lock);
 313}
 314
 315void br_fdb_cleanup(struct work_struct *work)
 316{
 317        struct net_bridge *br = container_of(work, struct net_bridge,
 318                                             gc_work.work);
 319        unsigned long delay = hold_time(br);
 320        unsigned long work_delay = delay;
 321        unsigned long now = jiffies;
 322        int i;
 323
 324        for (i = 0; i < BR_HASH_SIZE; i++) {
 325                struct net_bridge_fdb_entry *f;
 326                struct hlist_node *n;
 327
 328                if (!br->hash[i].first)
 329                        continue;
 330
 331                spin_lock_bh(&br->hash_lock);
 332                hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 333                        unsigned long this_timer;
 334
 335                        if (f->is_static)
 336                                continue;
 337                        if (f->added_by_external_learn)
 338                                continue;
 339                        this_timer = f->updated + delay;
 340                        if (time_after(this_timer, now))
 341                                work_delay = min(work_delay, this_timer - now);
 342                        else
 343                                fdb_delete(br, f);
 344                }
 345                spin_unlock_bh(&br->hash_lock);
 346                cond_resched();
 347        }
 348
 349        /* Cleanup minimum 10 milliseconds apart */
 350        work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
 351        mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
 352}
 353
 354/* Completely flush all dynamic entries in forwarding database.*/
 355void br_fdb_flush(struct net_bridge *br)
 356{
 357        int i;
 358
 359        spin_lock_bh(&br->hash_lock);
 360        for (i = 0; i < BR_HASH_SIZE; i++) {
 361                struct net_bridge_fdb_entry *f;
 362                struct hlist_node *n;
 363                hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 364                        if (!f->is_static)
 365                                fdb_delete(br, f);
 366                }
 367        }
 368        spin_unlock_bh(&br->hash_lock);
 369}
 370
 371/* Flush all entries referring to a specific port.
 372 * if do_all is set also flush static entries
 373 * if vid is set delete all entries that match the vlan_id
 374 */
 375void br_fdb_delete_by_port(struct net_bridge *br,
 376                           const struct net_bridge_port *p,
 377                           u16 vid,
 378                           int do_all)
 379{
 380        int i;
 381
 382        spin_lock_bh(&br->hash_lock);
 383        for (i = 0; i < BR_HASH_SIZE; i++) {
 384                struct hlist_node *h, *g;
 385
 386                hlist_for_each_safe(h, g, &br->hash[i]) {
 387                        struct net_bridge_fdb_entry *f
 388                                = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 389                        if (f->dst != p)
 390                                continue;
 391
 392                        if (!do_all)
 393                                if (f->is_static || (vid && f->vlan_id != vid))
 394                                        continue;
 395
 396                        if (f->is_local)
 397                                fdb_delete_local(br, p, f);
 398                        else
 399                                fdb_delete(br, f);
 400                }
 401        }
 402        spin_unlock_bh(&br->hash_lock);
 403}
 404
 405#if IS_ENABLED(CONFIG_ATM_LANE)
 406/* Interface used by ATM LANE hook to test
 407 * if an addr is on some other bridge port */
 408int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 409{
 410        struct net_bridge_fdb_entry *fdb;
 411        struct net_bridge_port *port;
 412        int ret;
 413
 414        rcu_read_lock();
 415        port = br_port_get_rcu(dev);
 416        if (!port)
 417                ret = 0;
 418        else {
 419                fdb = br_fdb_find_rcu(port->br, addr, 0);
 420                ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 421                        fdb->dst->state == BR_STATE_FORWARDING;
 422        }
 423        rcu_read_unlock();
 424
 425        return ret;
 426}
 427#endif /* CONFIG_ATM_LANE */
 428
 429/*
 430 * Fill buffer with forwarding table records in
 431 * the API format.
 432 */
 433int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 434                   unsigned long maxnum, unsigned long skip)
 435{
 436        struct __fdb_entry *fe = buf;
 437        int i, num = 0;
 438        struct net_bridge_fdb_entry *f;
 439
 440        memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 441
 442        rcu_read_lock();
 443        for (i = 0; i < BR_HASH_SIZE; i++) {
 444                hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 445                        if (num >= maxnum)
 446                                goto out;
 447
 448                        if (has_expired(br, f))
 449                                continue;
 450
 451                        /* ignore pseudo entry for local MAC address */
 452                        if (!f->dst)
 453                                continue;
 454
 455                        if (skip) {
 456                                --skip;
 457                                continue;
 458                        }
 459
 460                        /* convert from internal format to API */
 461                        memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 462
 463                        /* due to ABI compat need to split into hi/lo */
 464                        fe->port_no = f->dst->port_no;
 465                        fe->port_hi = f->dst->port_no >> 8;
 466
 467                        fe->is_local = f->is_local;
 468                        if (!f->is_static)
 469                                fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 470                        ++fe;
 471                        ++num;
 472                }
 473        }
 474
 475 out:
 476        rcu_read_unlock();
 477
 478        return num;
 479}
 480
 481static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 482                                               struct net_bridge_port *source,
 483                                               const unsigned char *addr,
 484                                               __u16 vid,
 485                                               unsigned char is_local,
 486                                               unsigned char is_static)
 487{
 488        struct net_bridge_fdb_entry *fdb;
 489
 490        fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 491        if (fdb) {
 492                memcpy(fdb->addr.addr, addr, ETH_ALEN);
 493                fdb->dst = source;
 494                fdb->vlan_id = vid;
 495                fdb->is_local = is_local;
 496                fdb->is_static = is_static;
 497                fdb->added_by_user = 0;
 498                fdb->added_by_external_learn = 0;
 499                fdb->offloaded = 0;
 500                fdb->updated = fdb->used = jiffies;
 501                hlist_add_head_rcu(&fdb->hlist, head);
 502        }
 503        return fdb;
 504}
 505
 506static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 507                  const unsigned char *addr, u16 vid)
 508{
 509        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 510        struct net_bridge_fdb_entry *fdb;
 511
 512        if (!is_valid_ether_addr(addr))
 513                return -EINVAL;
 514
 515        fdb = br_fdb_find(br, addr, vid);
 516        if (fdb) {
 517                /* it is okay to have multiple ports with same
 518                 * address, just use the first one.
 519                 */
 520                if (fdb->is_local)
 521                        return 0;
 522                br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 523                       source ? source->dev->name : br->dev->name, addr, vid);
 524                fdb_delete(br, fdb);
 525        }
 526
 527        fdb = fdb_create(head, source, addr, vid, 1, 1);
 528        if (!fdb)
 529                return -ENOMEM;
 530
 531        fdb_add_hw_addr(br, addr);
 532        fdb_notify(br, fdb, RTM_NEWNEIGH);
 533        return 0;
 534}
 535
 536/* Add entry for local address of interface */
 537int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 538                  const unsigned char *addr, u16 vid)
 539{
 540        int ret;
 541
 542        spin_lock_bh(&br->hash_lock);
 543        ret = fdb_insert(br, source, addr, vid);
 544        spin_unlock_bh(&br->hash_lock);
 545        return ret;
 546}
 547
 548void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 549                   const unsigned char *addr, u16 vid, bool added_by_user)
 550{
 551        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 552        struct net_bridge_fdb_entry *fdb;
 553        bool fdb_modified = false;
 554
 555        /* some users want to always flood. */
 556        if (hold_time(br) == 0)
 557                return;
 558
 559        /* ignore packets unless we are using this port */
 560        if (!(source->state == BR_STATE_LEARNING ||
 561              source->state == BR_STATE_FORWARDING))
 562                return;
 563
 564        fdb = fdb_find_rcu(head, addr, vid);
 565        if (likely(fdb)) {
 566                /* attempt to update an entry for a local interface */
 567                if (unlikely(fdb->is_local)) {
 568                        if (net_ratelimit())
 569                                br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 570                                        source->dev->name, addr, vid);
 571                } else {
 572                        unsigned long now = jiffies;
 573
 574                        /* fastpath: update of existing entry */
 575                        if (unlikely(source != fdb->dst)) {
 576                                fdb->dst = source;
 577                                fdb_modified = true;
 578                                /* Take over HW learned entry */
 579                                if (unlikely(fdb->added_by_external_learn))
 580                                        fdb->added_by_external_learn = 0;
 581                        }
 582                        if (now != fdb->updated)
 583                                fdb->updated = now;
 584                        if (unlikely(added_by_user))
 585                                fdb->added_by_user = 1;
 586                        if (unlikely(fdb_modified)) {
 587                                trace_br_fdb_update(br, source, addr, vid, added_by_user);
 588                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 589                        }
 590                }
 591        } else {
 592                spin_lock(&br->hash_lock);
 593                if (likely(!fdb_find_rcu(head, addr, vid))) {
 594                        fdb = fdb_create(head, source, addr, vid, 0, 0);
 595                        if (fdb) {
 596                                if (unlikely(added_by_user))
 597                                        fdb->added_by_user = 1;
 598                                trace_br_fdb_update(br, source, addr, vid, added_by_user);
 599                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 600                        }
 601                }
 602                /* else  we lose race and someone else inserts
 603                 * it first, don't bother updating
 604                 */
 605                spin_unlock(&br->hash_lock);
 606        }
 607}
 608
 609static int fdb_to_nud(const struct net_bridge *br,
 610                      const struct net_bridge_fdb_entry *fdb)
 611{
 612        if (fdb->is_local)
 613                return NUD_PERMANENT;
 614        else if (fdb->is_static)
 615                return NUD_NOARP;
 616        else if (has_expired(br, fdb))
 617                return NUD_STALE;
 618        else
 619                return NUD_REACHABLE;
 620}
 621
 622static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 623                         const struct net_bridge_fdb_entry *fdb,
 624                         u32 portid, u32 seq, int type, unsigned int flags)
 625{
 626        unsigned long now = jiffies;
 627        struct nda_cacheinfo ci;
 628        struct nlmsghdr *nlh;
 629        struct ndmsg *ndm;
 630
 631        nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 632        if (nlh == NULL)
 633                return -EMSGSIZE;
 634
 635        ndm = nlmsg_data(nlh);
 636        ndm->ndm_family  = AF_BRIDGE;
 637        ndm->ndm_pad1    = 0;
 638        ndm->ndm_pad2    = 0;
 639        ndm->ndm_flags   = 0;
 640        ndm->ndm_type    = 0;
 641        ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 642        ndm->ndm_state   = fdb_to_nud(br, fdb);
 643
 644        if (fdb->offloaded)
 645                ndm->ndm_flags |= NTF_OFFLOADED;
 646        if (fdb->added_by_external_learn)
 647                ndm->ndm_flags |= NTF_EXT_LEARNED;
 648
 649        if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 650                goto nla_put_failure;
 651        if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 652                goto nla_put_failure;
 653        ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 654        ci.ndm_confirmed = 0;
 655        ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 656        ci.ndm_refcnt    = 0;
 657        if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 658                goto nla_put_failure;
 659
 660        if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 661                goto nla_put_failure;
 662
 663        nlmsg_end(skb, nlh);
 664        return 0;
 665
 666nla_put_failure:
 667        nlmsg_cancel(skb, nlh);
 668        return -EMSGSIZE;
 669}
 670
 671static inline size_t fdb_nlmsg_size(void)
 672{
 673        return NLMSG_ALIGN(sizeof(struct ndmsg))
 674                + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 675                + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 676                + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 677                + nla_total_size(sizeof(struct nda_cacheinfo));
 678}
 679
 680static void fdb_notify(struct net_bridge *br,
 681                       const struct net_bridge_fdb_entry *fdb, int type)
 682{
 683        struct net *net = dev_net(br->dev);
 684        struct sk_buff *skb;
 685        int err = -ENOBUFS;
 686
 687        br_switchdev_fdb_notify(fdb, type);
 688
 689        skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 690        if (skb == NULL)
 691                goto errout;
 692
 693        err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 694        if (err < 0) {
 695                /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 696                WARN_ON(err == -EMSGSIZE);
 697                kfree_skb(skb);
 698                goto errout;
 699        }
 700        rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 701        return;
 702errout:
 703        rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 704}
 705
 706/* Dump information about entries, in response to GETNEIGH */
 707int br_fdb_dump(struct sk_buff *skb,
 708                struct netlink_callback *cb,
 709                struct net_device *dev,
 710                struct net_device *filter_dev,
 711                int *idx)
 712{
 713        struct net_bridge *br = netdev_priv(dev);
 714        int err = 0;
 715        int i;
 716
 717        if (!(dev->priv_flags & IFF_EBRIDGE))
 718                goto out;
 719
 720        if (!filter_dev) {
 721                err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 722                if (err < 0)
 723                        goto out;
 724        }
 725
 726        for (i = 0; i < BR_HASH_SIZE; i++) {
 727                struct net_bridge_fdb_entry *f;
 728
 729                hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 730
 731                        if (*idx < cb->args[2])
 732                                goto skip;
 733
 734                        if (filter_dev &&
 735                            (!f->dst || f->dst->dev != filter_dev)) {
 736                                if (filter_dev != dev)
 737                                        goto skip;
 738                                /* !f->dst is a special case for bridge
 739                                 * It means the MAC belongs to the bridge
 740                                 * Therefore need a little more filtering
 741                                 * we only want to dump the !f->dst case
 742                                 */
 743                                if (f->dst)
 744                                        goto skip;
 745                        }
 746                        if (!filter_dev && f->dst)
 747                                goto skip;
 748
 749                        err = fdb_fill_info(skb, br, f,
 750                                            NETLINK_CB(cb->skb).portid,
 751                                            cb->nlh->nlmsg_seq,
 752                                            RTM_NEWNEIGH,
 753                                            NLM_F_MULTI);
 754                        if (err < 0)
 755                                goto out;
 756skip:
 757                        *idx += 1;
 758                }
 759        }
 760
 761out:
 762        return err;
 763}
 764
 765/* Update (create or replace) forwarding database entry */
 766static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 767                         const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 768{
 769        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 770        struct net_bridge_fdb_entry *fdb;
 771        bool modified = false;
 772
 773        /* If the port cannot learn allow only local and static entries */
 774        if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 775            !(source->state == BR_STATE_LEARNING ||
 776              source->state == BR_STATE_FORWARDING))
 777                return -EPERM;
 778
 779        if (!source && !(state & NUD_PERMANENT)) {
 780                pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 781                        br->dev->name);
 782                return -EINVAL;
 783        }
 784
 785        fdb = br_fdb_find(br, addr, vid);
 786        if (fdb == NULL) {
 787                if (!(flags & NLM_F_CREATE))
 788                        return -ENOENT;
 789
 790                fdb = fdb_create(head, source, addr, vid, 0, 0);
 791                if (!fdb)
 792                        return -ENOMEM;
 793
 794                modified = true;
 795        } else {
 796                if (flags & NLM_F_EXCL)
 797                        return -EEXIST;
 798
 799                if (fdb->dst != source) {
 800                        fdb->dst = source;
 801                        modified = true;
 802                }
 803        }
 804
 805        if (fdb_to_nud(br, fdb) != state) {
 806                if (state & NUD_PERMANENT) {
 807                        fdb->is_local = 1;
 808                        if (!fdb->is_static) {
 809                                fdb->is_static = 1;
 810                                fdb_add_hw_addr(br, addr);
 811                        }
 812                } else if (state & NUD_NOARP) {
 813                        fdb->is_local = 0;
 814                        if (!fdb->is_static) {
 815                                fdb->is_static = 1;
 816                                fdb_add_hw_addr(br, addr);
 817                        }
 818                } else {
 819                        fdb->is_local = 0;
 820                        if (fdb->is_static) {
 821                                fdb->is_static = 0;
 822                                fdb_del_hw_addr(br, addr);
 823                        }
 824                }
 825
 826                modified = true;
 827        }
 828        fdb->added_by_user = 1;
 829
 830        fdb->used = jiffies;
 831        if (modified) {
 832                fdb->updated = jiffies;
 833                fdb_notify(br, fdb, RTM_NEWNEIGH);
 834        }
 835
 836        return 0;
 837}
 838
 839static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 840                        struct net_bridge_port *p, const unsigned char *addr,
 841                        u16 nlh_flags, u16 vid)
 842{
 843        int err = 0;
 844
 845        if (ndm->ndm_flags & NTF_USE) {
 846                if (!p) {
 847                        pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 848                                br->dev->name);
 849                        return -EINVAL;
 850                }
 851                local_bh_disable();
 852                rcu_read_lock();
 853                br_fdb_update(br, p, addr, vid, true);
 854                rcu_read_unlock();
 855                local_bh_enable();
 856        } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
 857                err = br_fdb_external_learn_add(br, p, addr, vid);
 858        } else {
 859                spin_lock_bh(&br->hash_lock);
 860                err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 861                                    nlh_flags, vid);
 862                spin_unlock_bh(&br->hash_lock);
 863        }
 864
 865        return err;
 866}
 867
 868/* Add new permanent fdb entry with RTM_NEWNEIGH */
 869int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 870               struct net_device *dev,
 871               const unsigned char *addr, u16 vid, u16 nlh_flags)
 872{
 873        struct net_bridge_vlan_group *vg;
 874        struct net_bridge_port *p = NULL;
 875        struct net_bridge_vlan *v;
 876        struct net_bridge *br = NULL;
 877        int err = 0;
 878
 879        trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);
 880
 881        if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 882                pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 883                return -EINVAL;
 884        }
 885
 886        if (is_zero_ether_addr(addr)) {
 887                pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 888                return -EINVAL;
 889        }
 890
 891        if (dev->priv_flags & IFF_EBRIDGE) {
 892                br = netdev_priv(dev);
 893                vg = br_vlan_group(br);
 894        } else {
 895                p = br_port_get_rtnl(dev);
 896                if (!p) {
 897                        pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 898                                dev->name);
 899                        return -EINVAL;
 900                }
 901                br = p->br;
 902                vg = nbp_vlan_group(p);
 903        }
 904
 905        if (vid) {
 906                v = br_vlan_find(vg, vid);
 907                if (!v || !br_vlan_should_use(v)) {
 908                        pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 909                        return -EINVAL;
 910                }
 911
 912                /* VID was specified, so use it. */
 913                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 914        } else {
 915                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 916                if (err || !vg || !vg->num_vlans)
 917                        goto out;
 918
 919                /* We have vlans configured on this port and user didn't
 920                 * specify a VLAN.  To be nice, add/update entry for every
 921                 * vlan on this port.
 922                 */
 923                list_for_each_entry(v, &vg->vlan_list, vlist) {
 924                        if (!br_vlan_should_use(v))
 925                                continue;
 926                        err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 927                        if (err)
 928                                goto out;
 929                }
 930        }
 931
 932out:
 933        return err;
 934}
 935
 936static int fdb_delete_by_addr_and_port(struct net_bridge *br,
 937                                       const struct net_bridge_port *p,
 938                                       const u8 *addr, u16 vlan)
 939{
 940        struct net_bridge_fdb_entry *fdb;
 941
 942        fdb = br_fdb_find(br, addr, vlan);
 943        if (!fdb || fdb->dst != p)
 944                return -ENOENT;
 945
 946        fdb_delete(br, fdb);
 947
 948        return 0;
 949}
 950
 951static int __br_fdb_delete(struct net_bridge *br,
 952                           const struct net_bridge_port *p,
 953                           const unsigned char *addr, u16 vid)
 954{
 955        int err;
 956
 957        spin_lock_bh(&br->hash_lock);
 958        err = fdb_delete_by_addr_and_port(br, p, addr, vid);
 959        spin_unlock_bh(&br->hash_lock);
 960
 961        return err;
 962}
 963
 964/* Remove neighbor entry with RTM_DELNEIGH */
 965int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 966                  struct net_device *dev,
 967                  const unsigned char *addr, u16 vid)
 968{
 969        struct net_bridge_vlan_group *vg;
 970        struct net_bridge_port *p = NULL;
 971        struct net_bridge_vlan *v;
 972        struct net_bridge *br;
 973        int err;
 974
 975        if (dev->priv_flags & IFF_EBRIDGE) {
 976                br = netdev_priv(dev);
 977                vg = br_vlan_group(br);
 978        } else {
 979                p = br_port_get_rtnl(dev);
 980                if (!p) {
 981                        pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 982                                dev->name);
 983                        return -EINVAL;
 984                }
 985                vg = nbp_vlan_group(p);
 986                br = p->br;
 987        }
 988
 989        if (vid) {
 990                v = br_vlan_find(vg, vid);
 991                if (!v) {
 992                        pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 993                        return -EINVAL;
 994                }
 995
 996                err = __br_fdb_delete(br, p, addr, vid);
 997        } else {
 998                err = -ENOENT;
 999                err &= __br_fdb_delete(br, p, addr, 0);
1000                if (!vg || !vg->num_vlans)

1001                        return err;
1002
1003                list_for_each_entry(v, &vg->vlan_list, vlist) {
1004                        if (!br_vlan_should_use(v))
1005                                continue;
1006                        err &= __br_fdb_delete(br, p, addr, v->vid);
1007                }
1008        }
1009
1010        return err;
1011}
1012
1013int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1014{
1015        struct net_bridge_fdb_entry *fdb, *tmp;
1016        int i;
1017        int err;
1018
1019        ASSERT_RTNL();
1020
1021        for (i = 0; i < BR_HASH_SIZE; i++) {
1022                hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1023                        /* We only care for static entries */
1024                        if (!fdb->is_static)
1025                                continue;
1026
1027                        err = dev_uc_add(p->dev, fdb->addr.addr);
1028                        if (err)
1029                                goto rollback;
1030                }
1031        }
1032        return 0;
1033
1034rollback:
1035        for (i = 0; i < BR_HASH_SIZE; i++) {
1036                hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1037                        /* If we reached the fdb that failed, we can stop */
1038                        if (tmp == fdb)
1039                                break;
1040
1041                        /* We only care for static entries */
1042                        if (!tmp->is_static)
1043                                continue;
1044
1045                        dev_uc_del(p->dev, tmp->addr.addr);
1046                }
1047        }
1048        return err;
1049}
1050
1051void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1052{
1053        struct net_bridge_fdb_entry *fdb;
1054        int i;
1055
1056        ASSERT_RTNL();
1057
1058        for (i = 0; i < BR_HASH_SIZE; i++) {
1059                hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1060                        /* We only care for static entries */
1061                        if (!fdb->is_static)
1062                                continue;
1063
1064                        dev_uc_del(p->dev, fdb->addr.addr);
1065                }
1066        }
1067}
1068
1069int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1070                              const unsigned char *addr, u16 vid)
1071{
1072        struct net_bridge_fdb_entry *fdb;
1073        struct hlist_head *head;
1074        bool modified = false;
1075        int err = 0;
1076
1077        trace_br_fdb_external_learn_add(br, p, addr, vid);
1078
1079        spin_lock_bh(&br->hash_lock);
1080
1081        head = &br->hash[br_mac_hash(addr, vid)];
1082        fdb = br_fdb_find(br, addr, vid);
1083        if (!fdb) {
1084                fdb = fdb_create(head, p, addr, vid, 0, 0);
1085                if (!fdb) {
1086                        err = -ENOMEM;
1087                        goto err_unlock;
1088                }
1089                fdb->added_by_external_learn = 1;
1090                fdb_notify(br, fdb, RTM_NEWNEIGH);
1091        } else {
1092                fdb->updated = jiffies;
1093
1094                if (fdb->dst != p) {
1095                        fdb->dst = p;
1096                        modified = true;
1097                }
1098
1099                if (fdb->added_by_external_learn) {
1100                        /* Refresh entry */
1101                        fdb->used = jiffies;
1102                } else if (!fdb->added_by_user) {
1103                        /* Take over SW learned entry */
1104                        fdb->added_by_external_learn = 1;
1105                        modified = true;
1106                }
1107
1108                if (modified)
1109                        fdb_notify(br, fdb, RTM_NEWNEIGH);
1110        }
1111
1112err_unlock:
1113        spin_unlock_bh(&br->hash_lock);
1114
1115        return err;
1116}
1117
1118int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1119                              const unsigned char *addr, u16 vid)
1120{
1121        struct net_bridge_fdb_entry *fdb;
1122        int err = 0;
1123
1124        spin_lock_bh(&br->hash_lock);
1125
1126        fdb = br_fdb_find(br, addr, vid);
1127        if (fdb && fdb->added_by_external_learn)
1128                fdb_delete(br, fdb);
1129        else
1130                err = -ENOENT;
1131
1132        spin_unlock_bh(&br->hash_lock);
1133
1134        return err;
1135}
1136
1137void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
1138                          const unsigned char *addr, u16 vid)
1139{
1140        struct net_bridge_fdb_entry *fdb;
1141
1142        spin_lock_bh(&br->hash_lock);
1143
1144        fdb = br_fdb_find(br, addr, vid);
1145        if (fdb)
1146                fdb->offloaded = 1;
1147
1148        spin_unlock_bh(&br->hash_lock);
1149}
1150