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 "br_private.h"
  29
  30static struct kmem_cache *br_fdb_cache __read_mostly;
  31static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
  32                                             const unsigned char *addr,
  33                                             __u16 vid);
  34static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
  35                      const unsigned char *addr, u16 vid);
  36static void fdb_notify(struct net_bridge *br,
  37                       const struct net_bridge_fdb_entry *, int);
  38
  39static u32 fdb_salt __read_mostly;
  40
  41int __init br_fdb_init(void)
  42{
  43        br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
  44                                         sizeof(struct net_bridge_fdb_entry),
  45                                         0,
  46                                         SLAB_HWCACHE_ALIGN, NULL);
  47        if (!br_fdb_cache)
  48                return -ENOMEM;
  49
  50        get_random_bytes(&fdb_salt, sizeof(fdb_salt));
  51        return 0;
  52}
  53
  54void br_fdb_fini(void)
  55{
  56        kmem_cache_destroy(br_fdb_cache);
  57}
  58
  59
  60/* if topology_changing then use forward_delay (default 15 sec)
  61 * otherwise keep longer (default 5 minutes)
  62 */
  63static inline unsigned long hold_time(const struct net_bridge *br)
  64{
  65        return br->topology_change ? br->forward_delay : br->ageing_time;
  66}
  67
  68static inline int has_expired(const struct net_bridge *br,
  69                                  const struct net_bridge_fdb_entry *fdb)
  70{
  71        return !fdb->is_static &&
  72                time_before_eq(fdb->updated + hold_time(br), jiffies);
  73}
  74
  75static inline int br_mac_hash(const unsigned char *mac, __u16 vid)
  76{
  77        /* use 1 byte of OUI and 3 bytes of NIC */
  78        u32 key = get_unaligned((u32 *)(mac + 2));
  79        return jhash_2words(key, vid, fdb_salt) & (BR_HASH_SIZE - 1);
  80}
  81
  82static 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/* When a static FDB entry is added, the mac address from the entry is
  90 * added to the bridge private HW address list and all required ports
  91 * are then updated with the new information.
  92 * Called under RTNL.
  93 */
  94static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
  95{
  96        int err;
  97        struct net_bridge_port *p;
  98
  99        ASSERT_RTNL();
 100
 101        list_for_each_entry(p, &br->port_list, list) {
 102                if (!br_promisc_port(p)) {
 103                        err = dev_uc_add(p->dev, addr);
 104                        if (err)
 105                                goto undo;
 106                }
 107        }
 108
 109        return;
 110undo:
 111        list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 112                if (!br_promisc_port(p))
 113                        dev_uc_del(p->dev, addr);
 114        }
 115}
 116
 117/* When a static FDB entry is deleted, the HW address from that entry is
 118 * also removed from the bridge private HW address list and updates all
 119 * the ports with needed information.
 120 * Called under RTNL.
 121 */
 122static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
 123{
 124        struct net_bridge_port *p;
 125
 126        ASSERT_RTNL();
 127
 128        list_for_each_entry(p, &br->port_list, list) {
 129                if (!br_promisc_port(p))
 130                        dev_uc_del(p->dev, addr);
 131        }
 132}
 133
 134static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
 135{
 136        struct switchdev_obj_port_fdb fdb = {
 137                .obj = {
 138                        .orig_dev = f->dst->dev,
 139                        .id = SWITCHDEV_OBJ_ID_PORT_FDB,
 140                        .flags = SWITCHDEV_F_DEFER,
 141                },
 142                .vid = f->vlan_id,
 143        };
 144
 145        ether_addr_copy(fdb.addr, f->addr.addr);
 146        switchdev_port_obj_del(f->dst->dev, &fdb.obj);
 147}
 148
 149static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 150{
 151        if (f->is_static)
 152                fdb_del_hw_addr(br, f->addr.addr);
 153
 154        if (f->added_by_external_learn)
 155                fdb_del_external_learn(f);
 156
 157        hlist_del_rcu(&f->hlist);
 158        fdb_notify(br, f, RTM_DELNEIGH);
 159        call_rcu(&f->rcu, fdb_rcu_free);
 160}
 161
 162/* Delete a local entry if no other port had the same address. */
 163static void fdb_delete_local(struct net_bridge *br,
 164                             const struct net_bridge_port *p,
 165                             struct net_bridge_fdb_entry *f)
 166{
 167        const unsigned char *addr = f->addr.addr;
 168        struct net_bridge_vlan_group *vg;
 169        const struct net_bridge_vlan *v;
 170        struct net_bridge_port *op;
 171        u16 vid = f->vlan_id;
 172
 173        /* Maybe another port has same hw addr? */
 174        list_for_each_entry(op, &br->port_list, list) {
 175                vg = nbp_vlan_group(op);
 176                if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
 177                    (!vid || br_vlan_find(vg, vid))) {
 178                        f->dst = op;
 179                        f->added_by_user = 0;
 180                        return;
 181                }
 182        }
 183
 184        vg = br_vlan_group(br);
 185        v = br_vlan_find(vg, vid);
 186        /* Maybe bridge device has same hw addr? */
 187        if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
 188            (!vid || (v && br_vlan_should_use(v)))) {
 189                f->dst = NULL;
 190                f->added_by_user = 0;
 191                return;
 192        }
 193
 194        fdb_delete(br, f);
 195}
 196
 197void br_fdb_find_delete_local(struct net_bridge *br,
 198                              const struct net_bridge_port *p,
 199                              const unsigned char *addr, u16 vid)
 200{
 201        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 202        struct net_bridge_fdb_entry *f;
 203
 204        spin_lock_bh(&br->hash_lock);
 205        f = fdb_find(head, addr, vid);
 206        if (f && f->is_local && !f->added_by_user && f->dst == p)
 207                fdb_delete_local(br, p, f);
 208        spin_unlock_bh(&br->hash_lock);
 209}
 210
 211void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 212{
 213        struct net_bridge_vlan_group *vg;
 214        struct net_bridge *br = p->br;
 215        struct net_bridge_vlan *v;
 216        int i;
 217
 218        spin_lock_bh(&br->hash_lock);
 219
 220        vg = nbp_vlan_group(p);
 221        /* Search all chains since old address/hash is unknown */
 222        for (i = 0; i < BR_HASH_SIZE; i++) {
 223                struct hlist_node *h;
 224                hlist_for_each(h, &br->hash[i]) {
 225                        struct net_bridge_fdb_entry *f;
 226
 227                        f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 228                        if (f->dst == p && f->is_local && !f->added_by_user) {
 229                                /* delete old one */
 230                                fdb_delete_local(br, p, f);
 231
 232                                /* if this port has no vlan information
 233                                 * configured, we can safely be done at
 234                                 * this point.
 235                                 */
 236                                if (!vg || !vg->num_vlans)
 237                                        goto insert;
 238                        }
 239                }
 240        }
 241
 242insert:
 243        /* insert new address,  may fail if invalid address or dup. */
 244        fdb_insert(br, p, newaddr, 0);
 245
 246        if (!vg || !vg->num_vlans)
 247                goto done;
 248
 249        /* Now add entries for every VLAN configured on the port.
 250         * This function runs under RTNL so the bitmap will not change
 251         * from under us.
 252         */
 253        list_for_each_entry(v, &vg->vlan_list, vlist)
 254                fdb_insert(br, p, newaddr, v->vid);
 255
 256done:
 257        spin_unlock_bh(&br->hash_lock);
 258}
 259
 260void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
 261{
 262        struct net_bridge_vlan_group *vg;
 263        struct net_bridge_fdb_entry *f;
 264        struct net_bridge_vlan *v;
 265
 266        spin_lock_bh(&br->hash_lock);
 267
 268        /* If old entry was unassociated with any port, then delete it. */
 269        f = __br_fdb_get(br, br->dev->dev_addr, 0);
 270        if (f && f->is_local && !f->dst && !f->added_by_user)
 271                fdb_delete_local(br, NULL, f);
 272
 273        fdb_insert(br, NULL, newaddr, 0);
 274        vg = br_vlan_group(br);
 275        if (!vg || !vg->num_vlans)
 276                goto out;
 277        /* Now remove and add entries for every VLAN configured on the
 278         * bridge.  This function runs under RTNL so the bitmap will not
 279         * change from under us.
 280         */
 281        list_for_each_entry(v, &vg->vlan_list, vlist) {
 282                if (!br_vlan_should_use(v))
 283                        continue;
 284                f = __br_fdb_get(br, br->dev->dev_addr, v->vid);
 285                if (f && f->is_local && !f->dst && !f->added_by_user)
 286                        fdb_delete_local(br, NULL, f);
 287                fdb_insert(br, NULL, newaddr, v->vid);
 288        }
 289out:
 290        spin_unlock_bh(&br->hash_lock);
 291}
 292
 293void br_fdb_cleanup(unsigned long _data)
 294{
 295        struct net_bridge *br = (struct net_bridge *)_data;
 296        unsigned long delay = hold_time(br);
 297        unsigned long next_timer = jiffies + br->ageing_time;
 298        int i;
 299
 300        spin_lock(&br->hash_lock);
 301        for (i = 0; i < BR_HASH_SIZE; i++) {
 302                struct net_bridge_fdb_entry *f;
 303                struct hlist_node *n;
 304
 305                hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 306                        unsigned long this_timer;
 307                        if (f->is_static)
 308                                continue;
 309                        if (f->added_by_external_learn)
 310                                continue;
 311                        this_timer = f->updated + delay;
 312                        if (time_before_eq(this_timer, jiffies))
 313                                fdb_delete(br, f);
 314                        else if (time_before(this_timer, next_timer))
 315                                next_timer = this_timer;
 316                }
 317        }
 318        spin_unlock(&br->hash_lock);
 319
 320        mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
 321}
 322
 323/* Completely flush all dynamic entries in forwarding database.*/
 324void br_fdb_flush(struct net_bridge *br)
 325{
 326        int i;
 327
 328        spin_lock_bh(&br->hash_lock);
 329        for (i = 0; i < BR_HASH_SIZE; i++) {
 330                struct net_bridge_fdb_entry *f;
 331                struct hlist_node *n;
 332                hlist_for_each_entry_safe(f, n, &br->hash[i], hlist) {
 333                        if (!f->is_static)
 334                                fdb_delete(br, f);
 335                }
 336        }
 337        spin_unlock_bh(&br->hash_lock);
 338}
 339
 340/* Flush all entries referring to a specific port.
 341 * if do_all is set also flush static entries
 342 * if vid is set delete all entries that match the vlan_id
 343 */
 344void br_fdb_delete_by_port(struct net_bridge *br,
 345                           const struct net_bridge_port *p,
 346                           u16 vid,
 347                           int do_all)
 348{
 349        int i;
 350
 351        spin_lock_bh(&br->hash_lock);
 352        for (i = 0; i < BR_HASH_SIZE; i++) {
 353                struct hlist_node *h, *g;
 354
 355                hlist_for_each_safe(h, g, &br->hash[i]) {
 356                        struct net_bridge_fdb_entry *f
 357                                = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
 358                        if (f->dst != p)
 359                                continue;
 360
 361                        if (!do_all)
 362                                if (f->is_static || (vid && f->vlan_id != vid))
 363                                        continue;
 364
 365                        if (f->is_local)
 366                                fdb_delete_local(br, p, f);
 367                        else
 368                                fdb_delete(br, f);
 369                }
 370        }
 371        spin_unlock_bh(&br->hash_lock);
 372}
 373
 374/* No locking or refcounting, assumes caller has rcu_read_lock */
 375struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 376                                          const unsigned char *addr,
 377                                          __u16 vid)
 378{
 379        struct net_bridge_fdb_entry *fdb;
 380
 381        hlist_for_each_entry_rcu(fdb,
 382                                &br->hash[br_mac_hash(addr, vid)], hlist) {
 383                if (ether_addr_equal(fdb->addr.addr, addr) &&
 384                    fdb->vlan_id == vid) {
 385                        if (unlikely(has_expired(br, fdb)))
 386                                break;
 387                        return fdb;
 388                }
 389        }
 390
 391        return NULL;
 392}
 393
 394#if IS_ENABLED(CONFIG_ATM_LANE)
 395/* Interface used by ATM LANE hook to test
 396 * if an addr is on some other bridge port */
 397int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
 398{
 399        struct net_bridge_fdb_entry *fdb;
 400        struct net_bridge_port *port;
 401        int ret;
 402
 403        rcu_read_lock();
 404        port = br_port_get_rcu(dev);
 405        if (!port)
 406                ret = 0;
 407        else {
 408                fdb = __br_fdb_get(port->br, addr, 0);
 409                ret = fdb && fdb->dst && fdb->dst->dev != dev &&
 410                        fdb->dst->state == BR_STATE_FORWARDING;
 411        }
 412        rcu_read_unlock();
 413
 414        return ret;
 415}
 416#endif /* CONFIG_ATM_LANE */
 417
 418/*
 419 * Fill buffer with forwarding table records in
 420 * the API format.
 421 */
 422int br_fdb_fillbuf(struct net_bridge *br, void *buf,
 423                   unsigned long maxnum, unsigned long skip)
 424{
 425        struct __fdb_entry *fe = buf;
 426        int i, num = 0;
 427        struct net_bridge_fdb_entry *f;
 428
 429        memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
 430
 431        rcu_read_lock();
 432        for (i = 0; i < BR_HASH_SIZE; i++) {
 433                hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 434                        if (num >= maxnum)
 435                                goto out;
 436
 437                        if (has_expired(br, f))
 438                                continue;
 439
 440                        /* ignore pseudo entry for local MAC address */
 441                        if (!f->dst)
 442                                continue;
 443
 444                        if (skip) {
 445                                --skip;
 446                                continue;
 447                        }
 448
 449                        /* convert from internal format to API */
 450                        memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
 451
 452                        /* due to ABI compat need to split into hi/lo */
 453                        fe->port_no = f->dst->port_no;
 454                        fe->port_hi = f->dst->port_no >> 8;
 455
 456                        fe->is_local = f->is_local;
 457                        if (!f->is_static)
 458                                fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
 459                        ++fe;
 460                        ++num;
 461                }
 462        }
 463
 464 out:
 465        rcu_read_unlock();
 466
 467        return num;
 468}
 469
 470static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
 471                                             const unsigned char *addr,
 472                                             __u16 vid)
 473{
 474        struct net_bridge_fdb_entry *fdb;
 475
 476        hlist_for_each_entry(fdb, head, hlist) {
 477                if (ether_addr_equal(fdb->addr.addr, addr) &&
 478                    fdb->vlan_id == vid)
 479                        return fdb;
 480        }
 481        return NULL;
 482}
 483
 484static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
 485                                                 const unsigned char *addr,
 486                                                 __u16 vid)
 487{
 488        struct net_bridge_fdb_entry *fdb;
 489
 490        hlist_for_each_entry_rcu(fdb, head, hlist) {
 491                if (ether_addr_equal(fdb->addr.addr, addr) &&
 492                    fdb->vlan_id == vid)
 493                        return fdb;
 494        }
 495        return NULL;
 496}
 497
 498static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
 499                                               struct net_bridge_port *source,
 500                                               const unsigned char *addr,
 501                                               __u16 vid,
 502                                               unsigned char is_local,
 503                                               unsigned char is_static)
 504{
 505        struct net_bridge_fdb_entry *fdb;
 506
 507        fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
 508        if (fdb) {
 509                memcpy(fdb->addr.addr, addr, ETH_ALEN);
 510                fdb->dst = source;
 511                fdb->vlan_id = vid;
 512                fdb->is_local = is_local;
 513                fdb->is_static = is_static;
 514                fdb->added_by_user = 0;
 515                fdb->added_by_external_learn = 0;
 516                fdb->updated = fdb->used = jiffies;
 517                hlist_add_head_rcu(&fdb->hlist, head);
 518        }
 519        return fdb;
 520}
 521
 522static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 523                  const unsigned char *addr, u16 vid)
 524{
 525        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 526        struct net_bridge_fdb_entry *fdb;
 527
 528        if (!is_valid_ether_addr(addr))
 529                return -EINVAL;
 530
 531        fdb = fdb_find(head, addr, vid);
 532        if (fdb) {
 533                /* it is okay to have multiple ports with same
 534                 * address, just use the first one.
 535                 */
 536                if (fdb->is_local)
 537                        return 0;
 538                br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
 539                       source ? source->dev->name : br->dev->name, addr, vid);
 540                fdb_delete(br, fdb);
 541        }
 542
 543        fdb = fdb_create(head, source, addr, vid, 1, 1);
 544        if (!fdb)
 545                return -ENOMEM;
 546
 547        fdb_add_hw_addr(br, addr);
 548        fdb_notify(br, fdb, RTM_NEWNEIGH);
 549        return 0;
 550}
 551
 552/* Add entry for local address of interface */
 553int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 554                  const unsigned char *addr, u16 vid)
 555{
 556        int ret;
 557
 558        spin_lock_bh(&br->hash_lock);
 559        ret = fdb_insert(br, source, addr, vid);
 560        spin_unlock_bh(&br->hash_lock);
 561        return ret;
 562}
 563
 564void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 565                   const unsigned char *addr, u16 vid, bool added_by_user)
 566{
 567        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 568        struct net_bridge_fdb_entry *fdb;
 569        bool fdb_modified = false;
 570
 571        /* some users want to always flood. */
 572        if (hold_time(br) == 0)
 573                return;
 574
 575        /* ignore packets unless we are using this port */
 576        if (!(source->state == BR_STATE_LEARNING ||
 577              source->state == BR_STATE_FORWARDING))
 578                return;
 579
 580        fdb = fdb_find_rcu(head, addr, vid);
 581        if (likely(fdb)) {
 582                /* attempt to update an entry for a local interface */
 583                if (unlikely(fdb->is_local)) {
 584                        if (net_ratelimit())
 585                                br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
 586                                        source->dev->name, addr, vid);
 587                } else {
 588                        /* fastpath: update of existing entry */
 589                        if (unlikely(source != fdb->dst)) {
 590                                fdb->dst = source;
 591                                fdb_modified = true;
 592                        }
 593                        fdb->updated = jiffies;
 594                        if (unlikely(added_by_user))
 595                                fdb->added_by_user = 1;
 596                        if (unlikely(fdb_modified))
 597                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 598                }
 599        } else {
 600                spin_lock(&br->hash_lock);
 601                if (likely(!fdb_find(head, addr, vid))) {
 602                        fdb = fdb_create(head, source, addr, vid, 0, 0);
 603                        if (fdb) {
 604                                if (unlikely(added_by_user))
 605                                        fdb->added_by_user = 1;
 606                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 607                        }
 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
 616static 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
 629static 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   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 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 (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 652                goto nla_put_failure;
 653        if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 654                goto nla_put_failure;
 655        ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 656        ci.ndm_confirmed = 0;
 657        ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 658        ci.ndm_refcnt    = 0;
 659        if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 660                goto nla_put_failure;
 661
 662        if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 663                goto nla_put_failure;
 664
 665        nlmsg_end(skb, nlh);
 666        return 0;
 667
 668nla_put_failure:
 669        nlmsg_cancel(skb, nlh);
 670        return -EMSGSIZE;
 671}
 672
 673static inline size_t fdb_nlmsg_size(void)
 674{
 675        return NLMSG_ALIGN(sizeof(struct ndmsg))
 676                + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 677                + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 678                + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 679                + nla_total_size(sizeof(struct nda_cacheinfo));
 680}
 681
 682static void fdb_notify(struct net_bridge *br,
 683                       const struct net_bridge_fdb_entry *fdb, int type)
 684{
 685        struct net *net = dev_net(br->dev);
 686        struct sk_buff *skb;
 687        int err = -ENOBUFS;
 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 = fdb_find(head, 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 {
 857                spin_lock_bh(&br->hash_lock);
 858                err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 859                                    nlh_flags, vid);
 860                spin_unlock_bh(&br->hash_lock);
 861        }
 862
 863        return err;
 864}
 865
 866/* Add new permanent fdb entry with RTM_NEWNEIGH */
 867int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 868               struct net_device *dev,
 869               const unsigned char *addr, u16 vid, u16 nlh_flags)
 870{
 871        struct net_bridge_vlan_group *vg;
 872        struct net_bridge_port *p = NULL;
 873        struct net_bridge_vlan *v;
 874        struct net_bridge *br = NULL;
 875        int err = 0;
 876
 877        if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 878                pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 879                return -EINVAL;
 880        }
 881
 882        if (is_zero_ether_addr(addr)) {
 883                pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 884                return -EINVAL;
 885        }
 886
 887        if (dev->priv_flags & IFF_EBRIDGE) {
 888                br = netdev_priv(dev);
 889                vg = br_vlan_group(br);
 890        } else {
 891                p = br_port_get_rtnl(dev);
 892                if (!p) {
 893                        pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 894                                dev->name);
 895                        return -EINVAL;
 896                }
 897                br = p->br;
 898                vg = nbp_vlan_group(p);
 899        }
 900
 901        if (vid) {
 902                v = br_vlan_find(vg, vid);
 903                if (!v || !br_vlan_should_use(v)) {
 904                        pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 905                        return -EINVAL;
 906                }
 907
 908                /* VID was specified, so use it. */
 909                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 910        } else {
 911                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 912                if (err || !vg || !vg->num_vlans)
 913                        goto out;
 914
 915                /* We have vlans configured on this port and user didn't
 916                 * specify a VLAN.  To be nice, add/update entry for every
 917                 * vlan on this port.
 918                 */
 919                list_for_each_entry(v, &vg->vlan_list, vlist) {
 920                        if (!br_vlan_should_use(v))
 921                                continue;
 922                        err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 923                        if (err)
 924                                goto out;
 925                }
 926        }
 927
 928out:
 929        return err;
 930}
 931
 932static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 933                              u16 vid)
 934{
 935        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 936        struct net_bridge_fdb_entry *fdb;
 937
 938        fdb = fdb_find(head, addr, vid);
 939        if (!fdb)
 940                return -ENOENT;
 941
 942        fdb_delete(br, fdb);
 943        return 0;
 944}
 945
 946static int __br_fdb_delete_by_addr(struct net_bridge *br,
 947                                   const unsigned char *addr, u16 vid)
 948{
 949        int err;
 950
 951        spin_lock_bh(&br->hash_lock);
 952        err = fdb_delete_by_addr(br, addr, vid);
 953        spin_unlock_bh(&br->hash_lock);
 954
 955        return err;
 956}
 957
 958static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 959                                       const u8 *addr, u16 vlan)
 960{
 961        struct net_bridge *br = p->br;
 962        struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 963        struct net_bridge_fdb_entry *fdb;
 964
 965        fdb = fdb_find(head, addr, vlan);
 966        if (!fdb || fdb->dst != p)
 967                return -ENOENT;
 968
 969        fdb_delete(br, fdb);
 970        return 0;
 971}
 972
 973static int __br_fdb_delete(struct net_bridge_port *p,
 974                           const unsigned char *addr, u16 vid)
 975{
 976        int err;
 977
 978        spin_lock_bh(&p->br->hash_lock);
 979        err = fdb_delete_by_addr_and_port(p, addr, vid);
 980        spin_unlock_bh(&p->br->hash_lock);
 981
 982        return err;
 983}
 984
 985/* Remove neighbor entry with RTM_DELNEIGH */
 986int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 987                  struct net_device *dev,
 988                  const unsigned char *addr, u16 vid)
 989{
 990        struct net_bridge_vlan_group *vg;
 991        struct net_bridge_port *p = NULL;
 992        struct net_bridge_vlan *v;
 993        struct net_bridge *br = NULL;
 994        int err;
 995
 996        if (dev->priv_flags & IFF_EBRIDGE) {
 997                br = netdev_priv(dev);
 998                vg = br_vlan_group(br);
 999        } else {
1000                p = br_port_get_rtnl(dev);

1001                if (!p) {
1002                        pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1003                                dev->name);
1004                        return -EINVAL;
1005                }
1006                vg = nbp_vlan_group(p);
1007        }
1008
1009        if (vid) {
1010                v = br_vlan_find(vg, vid);
1011                if (!v) {
1012                        pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1013                        return -EINVAL;
1014                }
1015
1016                if (dev->priv_flags & IFF_EBRIDGE)
1017                        err = __br_fdb_delete_by_addr(br, addr, vid);
1018                else
1019                        err = __br_fdb_delete(p, addr, vid);
1020        } else {
1021                err = -ENOENT;
1022                if (dev->priv_flags & IFF_EBRIDGE)
1023                        err = __br_fdb_delete_by_addr(br, addr, 0);
1024                else
1025                        err &= __br_fdb_delete(p, addr, 0);
1026
1027                if (!vg || !vg->num_vlans)
1028                        goto out;
1029
1030                list_for_each_entry(v, &vg->vlan_list, vlist) {
1031                        if (!br_vlan_should_use(v))
1032                                continue;
1033                        if (dev->priv_flags & IFF_EBRIDGE)
1034                                err = __br_fdb_delete_by_addr(br, addr, v->vid);
1035                        else
1036                                err &= __br_fdb_delete(p, addr, v->vid);
1037                }
1038        }
1039out:
1040        return err;
1041}
1042
1043int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1044{
1045        struct net_bridge_fdb_entry *fdb, *tmp;
1046        int i;
1047        int err;
1048
1049        ASSERT_RTNL();
1050
1051        for (i = 0; i < BR_HASH_SIZE; i++) {
1052                hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1053                        /* We only care for static entries */
1054                        if (!fdb->is_static)
1055                                continue;
1056
1057                        err = dev_uc_add(p->dev, fdb->addr.addr);
1058                        if (err)
1059                                goto rollback;
1060                }
1061        }
1062        return 0;
1063
1064rollback:
1065        for (i = 0; i < BR_HASH_SIZE; i++) {
1066                hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1067                        /* If we reached the fdb that failed, we can stop */
1068                        if (tmp == fdb)
1069                                break;
1070
1071                        /* We only care for static entries */
1072                        if (!tmp->is_static)
1073                                continue;
1074
1075                        dev_uc_del(p->dev, tmp->addr.addr);
1076                }
1077        }
1078        return err;
1079}
1080
1081void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1082{
1083        struct net_bridge_fdb_entry *fdb;
1084        int i;
1085
1086        ASSERT_RTNL();
1087
1088        for (i = 0; i < BR_HASH_SIZE; i++) {
1089                hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1090                        /* We only care for static entries */
1091                        if (!fdb->is_static)
1092                                continue;
1093
1094                        dev_uc_del(p->dev, fdb->addr.addr);
1095                }
1096        }
1097}
1098
1099int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1100                              const unsigned char *addr, u16 vid)
1101{
1102        struct hlist_head *head;
1103        struct net_bridge_fdb_entry *fdb;
1104        int err = 0;
1105
1106        ASSERT_RTNL();
1107        spin_lock_bh(&br->hash_lock);
1108
1109        head = &br->hash[br_mac_hash(addr, vid)];
1110        fdb = fdb_find(head, addr, vid);
1111        if (!fdb) {
1112                fdb = fdb_create(head, p, addr, vid, 0, 0);
1113                if (!fdb) {
1114                        err = -ENOMEM;
1115                        goto err_unlock;
1116                }
1117                fdb->added_by_external_learn = 1;
1118                fdb_notify(br, fdb, RTM_NEWNEIGH);
1119        } else if (fdb->added_by_external_learn) {
1120                /* Refresh entry */
1121                fdb->updated = fdb->used = jiffies;
1122        } else if (!fdb->added_by_user) {
1123                /* Take over SW learned entry */
1124                fdb->added_by_external_learn = 1;
1125                fdb->updated = jiffies;
1126                fdb_notify(br, fdb, RTM_NEWNEIGH);
1127        }
1128
1129err_unlock:
1130        spin_unlock_bh(&br->hash_lock);
1131
1132        return err;
1133}
1134
1135int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1136                              const unsigned char *addr, u16 vid)
1137{
1138        struct hlist_head *head;
1139        struct net_bridge_fdb_entry *fdb;
1140        int err = 0;
1141
1142        ASSERT_RTNL();
1143        spin_lock_bh(&br->hash_lock);
1144
1145        head = &br->hash[br_mac_hash(addr, vid)];
1146        fdb = fdb_find(head, addr, vid);
1147        if (fdb && fdb->added_by_external_learn)
1148                fdb_delete(br, fdb);
1149        else
1150                err = -ENOENT;
1151
1152        spin_unlock_bh(&br->hash_lock);
1153
1154        return err;
1155}
1156