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 "
 539                       "as a received packet\n",
 540                       source ? source->dev->name : br->dev->name);
 541                fdb_delete(br, fdb);
 542        }
 543
 544        fdb = fdb_create(head, source, addr, vid, 1, 1);
 545        if (!fdb)
 546                return -ENOMEM;
 547
 548        fdb_add_hw_addr(br, addr);
 549        fdb_notify(br, fdb, RTM_NEWNEIGH);
 550        return 0;
 551}
 552
 553/* Add entry for local address of interface */
 554int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
 555                  const unsigned char *addr, u16 vid)
 556{
 557        int ret;
 558
 559        spin_lock_bh(&br->hash_lock);
 560        ret = fdb_insert(br, source, addr, vid);
 561        spin_unlock_bh(&br->hash_lock);
 562        return ret;
 563}
 564
 565void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 566                   const unsigned char *addr, u16 vid, bool added_by_user)
 567{
 568        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 569        struct net_bridge_fdb_entry *fdb;
 570        bool fdb_modified = false;
 571
 572        /* some users want to always flood. */
 573        if (hold_time(br) == 0)
 574                return;
 575
 576        /* ignore packets unless we are using this port */
 577        if (!(source->state == BR_STATE_LEARNING ||
 578              source->state == BR_STATE_FORWARDING))
 579                return;
 580
 581        fdb = fdb_find_rcu(head, addr, vid);
 582        if (likely(fdb)) {
 583                /* attempt to update an entry for a local interface */
 584                if (unlikely(fdb->is_local)) {
 585                        if (net_ratelimit())
 586                                br_warn(br, "received packet on %s with "
 587                                        "own address as source address\n",
 588                                        source->dev->name);
 589                } else {
 590                        /* fastpath: update of existing entry */
 591                        if (unlikely(source != fdb->dst)) {
 592                                fdb->dst = source;
 593                                fdb_modified = true;
 594                        }
 595                        fdb->updated = jiffies;
 596                        if (unlikely(added_by_user))
 597                                fdb->added_by_user = 1;
 598                        if (unlikely(fdb_modified))
 599                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 600                }
 601        } else {
 602                spin_lock(&br->hash_lock);
 603                if (likely(!fdb_find(head, addr, vid))) {
 604                        fdb = fdb_create(head, source, addr, vid, 0, 0);
 605                        if (fdb) {
 606                                if (unlikely(added_by_user))
 607                                        fdb->added_by_user = 1;
 608                                fdb_notify(br, fdb, RTM_NEWNEIGH);
 609                        }
 610                }
 611                /* else  we lose race and someone else inserts
 612                 * it first, don't bother updating
 613                 */
 614                spin_unlock(&br->hash_lock);
 615        }
 616}
 617
 618static int fdb_to_nud(const struct net_bridge *br,
 619                      const struct net_bridge_fdb_entry *fdb)
 620{
 621        if (fdb->is_local)
 622                return NUD_PERMANENT;
 623        else if (fdb->is_static)
 624                return NUD_NOARP;
 625        else if (has_expired(br, fdb))
 626                return NUD_STALE;
 627        else
 628                return NUD_REACHABLE;
 629}
 630
 631static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 632                         const struct net_bridge_fdb_entry *fdb,
 633                         u32 portid, u32 seq, int type, unsigned int flags)
 634{
 635        unsigned long now = jiffies;
 636        struct nda_cacheinfo ci;
 637        struct nlmsghdr *nlh;
 638        struct ndmsg *ndm;
 639
 640        nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
 641        if (nlh == NULL)
 642                return -EMSGSIZE;
 643
 644        ndm = nlmsg_data(nlh);
 645        ndm->ndm_family  = AF_BRIDGE;
 646        ndm->ndm_pad1    = 0;
 647        ndm->ndm_pad2    = 0;
 648        ndm->ndm_flags   = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 649        ndm->ndm_type    = 0;
 650        ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
 651        ndm->ndm_state   = fdb_to_nud(br, fdb);
 652
 653        if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 654                goto nla_put_failure;
 655        if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
 656                goto nla_put_failure;
 657        ci.ndm_used      = jiffies_to_clock_t(now - fdb->used);
 658        ci.ndm_confirmed = 0;
 659        ci.ndm_updated   = jiffies_to_clock_t(now - fdb->updated);
 660        ci.ndm_refcnt    = 0;
 661        if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
 662                goto nla_put_failure;
 663
 664        if (fdb->vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), &fdb->vlan_id))
 665                goto nla_put_failure;
 666
 667        nlmsg_end(skb, nlh);
 668        return 0;
 669
 670nla_put_failure:
 671        nlmsg_cancel(skb, nlh);
 672        return -EMSGSIZE;
 673}
 674
 675static inline size_t fdb_nlmsg_size(void)
 676{
 677        return NLMSG_ALIGN(sizeof(struct ndmsg))
 678                + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
 679                + nla_total_size(sizeof(u32)) /* NDA_MASTER */
 680                + nla_total_size(sizeof(u16)) /* NDA_VLAN */
 681                + nla_total_size(sizeof(struct nda_cacheinfo));
 682}
 683
 684static void fdb_notify(struct net_bridge *br,
 685                       const struct net_bridge_fdb_entry *fdb, int type)
 686{
 687        struct net *net = dev_net(br->dev);
 688        struct sk_buff *skb;
 689        int err = -ENOBUFS;
 690
 691        skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
 692        if (skb == NULL)
 693                goto errout;
 694
 695        err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
 696        if (err < 0) {
 697                /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
 698                WARN_ON(err == -EMSGSIZE);
 699                kfree_skb(skb);
 700                goto errout;
 701        }
 702        rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 703        return;
 704errout:
 705        rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
 706}
 707
 708/* Dump information about entries, in response to GETNEIGH */
 709int br_fdb_dump(struct sk_buff *skb,
 710                struct netlink_callback *cb,
 711                struct net_device *dev,
 712                struct net_device *filter_dev,
 713                int idx)
 714{
 715        struct net_bridge *br = netdev_priv(dev);
 716        int i;
 717
 718        if (!(dev->priv_flags & IFF_EBRIDGE))
 719                goto out;
 720
 721        if (!filter_dev)
 722                idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
 723
 724        for (i = 0; i < BR_HASH_SIZE; i++) {
 725                struct net_bridge_fdb_entry *f;
 726
 727                hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
 728                        int err;
 729
 730                        if (idx < cb->args[0])
 731                                goto skip;
 732
 733                        if (filter_dev &&
 734                            (!f->dst || f->dst->dev != filter_dev)) {
 735                                if (filter_dev != dev)
 736                                        goto skip;
 737                                /* !f->dst is a special case for bridge
 738                                 * It means the MAC belongs to the bridge
 739                                 * Therefore need a little more filtering
 740                                 * we only want to dump the !f->dst case
 741                                 */
 742                                if (f->dst)
 743                                        goto skip;
 744                        }
 745                        if (!filter_dev && f->dst)
 746                                goto skip;
 747
 748                        err = fdb_fill_info(skb, br, f,
 749                                            NETLINK_CB(cb->skb).portid,
 750                                            cb->nlh->nlmsg_seq,
 751                                            RTM_NEWNEIGH,
 752                                            NLM_F_MULTI);
 753                        if (err < 0) {
 754                                cb->args[1] = err;
 755                                break;
 756                        }
 757skip:
 758                        ++idx;
 759                }
 760        }
 761
 762out:
 763        return idx;
 764}
 765
 766/* Update (create or replace) forwarding database entry */
 767static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
 768                         const __u8 *addr, __u16 state, __u16 flags, __u16 vid)
 769{
 770        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 771        struct net_bridge_fdb_entry *fdb;
 772        bool modified = false;
 773
 774        /* If the port cannot learn allow only local and static entries */
 775        if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
 776            !(source->state == BR_STATE_LEARNING ||
 777              source->state == BR_STATE_FORWARDING))
 778                return -EPERM;
 779
 780        if (!source && !(state & NUD_PERMANENT)) {
 781                pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
 782                        br->dev->name);
 783                return -EINVAL;
 784        }
 785
 786        fdb = fdb_find(head, addr, vid);
 787        if (fdb == NULL) {
 788                if (!(flags & NLM_F_CREATE))
 789                        return -ENOENT;
 790
 791                fdb = fdb_create(head, source, addr, vid, 0, 0);
 792                if (!fdb)
 793                        return -ENOMEM;
 794
 795                modified = true;
 796        } else {
 797                if (flags & NLM_F_EXCL)
 798                        return -EEXIST;
 799
 800                if (fdb->dst != source) {
 801                        fdb->dst = source;
 802                        modified = true;
 803                }
 804        }
 805
 806        if (fdb_to_nud(br, fdb) != state) {
 807                if (state & NUD_PERMANENT) {
 808                        fdb->is_local = 1;
 809                        if (!fdb->is_static) {
 810                                fdb->is_static = 1;
 811                                fdb_add_hw_addr(br, addr);
 812                        }
 813                } else if (state & NUD_NOARP) {
 814                        fdb->is_local = 0;
 815                        if (!fdb->is_static) {
 816                                fdb->is_static = 1;
 817                                fdb_add_hw_addr(br, addr);
 818                        }
 819                } else {
 820                        fdb->is_local = 0;
 821                        if (fdb->is_static) {
 822                                fdb->is_static = 0;
 823                                fdb_del_hw_addr(br, addr);
 824                        }
 825                }
 826
 827                modified = true;
 828        }
 829        fdb->added_by_user = 1;
 830
 831        fdb->used = jiffies;
 832        if (modified) {
 833                fdb->updated = jiffies;
 834                fdb_notify(br, fdb, RTM_NEWNEIGH);
 835        }
 836
 837        return 0;
 838}
 839
 840static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
 841                        struct net_bridge_port *p, const unsigned char *addr,
 842                        u16 nlh_flags, u16 vid)
 843{
 844        int err = 0;
 845
 846        if (ndm->ndm_flags & NTF_USE) {
 847                if (!p) {
 848                        pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
 849                                br->dev->name);
 850                        return -EINVAL;
 851                }
 852                local_bh_disable();
 853                rcu_read_lock();
 854                br_fdb_update(br, p, addr, vid, true);
 855                rcu_read_unlock();
 856                local_bh_enable();
 857        } else {
 858                spin_lock_bh(&br->hash_lock);
 859                err = fdb_add_entry(br, p, addr, ndm->ndm_state,
 860                                    nlh_flags, vid);
 861                spin_unlock_bh(&br->hash_lock);
 862        }
 863
 864        return err;
 865}
 866
 867/* Add new permanent fdb entry with RTM_NEWNEIGH */
 868int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 869               struct net_device *dev,
 870               const unsigned char *addr, u16 vid, u16 nlh_flags)
 871{
 872        struct net_bridge_vlan_group *vg;
 873        struct net_bridge_port *p = NULL;
 874        struct net_bridge_vlan *v;
 875        struct net_bridge *br = NULL;
 876        int err = 0;
 877
 878        if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
 879                pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
 880                return -EINVAL;
 881        }
 882
 883        if (is_zero_ether_addr(addr)) {
 884                pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
 885                return -EINVAL;
 886        }
 887
 888        if (dev->priv_flags & IFF_EBRIDGE) {
 889                br = netdev_priv(dev);
 890                vg = br_vlan_group(br);
 891        } else {
 892                p = br_port_get_rtnl(dev);
 893                if (!p) {
 894                        pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 895                                dev->name);
 896                        return -EINVAL;
 897                }
 898                br = p->br;
 899                vg = nbp_vlan_group(p);
 900        }
 901
 902        if (vid) {
 903                v = br_vlan_find(vg, vid);
 904                if (!v || !br_vlan_should_use(v)) {
 905                        pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 906                        return -EINVAL;
 907                }
 908
 909                /* VID was specified, so use it. */
 910                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid);
 911        } else {
 912                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0);
 913                if (err || !vg || !vg->num_vlans)
 914                        goto out;
 915
 916                /* We have vlans configured on this port and user didn't
 917                 * specify a VLAN.  To be nice, add/update entry for every
 918                 * vlan on this port.
 919                 */
 920                list_for_each_entry(v, &vg->vlan_list, vlist) {
 921                        if (!br_vlan_should_use(v))
 922                                continue;
 923                        err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid);
 924                        if (err)
 925                                goto out;
 926                }
 927        }
 928
 929out:
 930        return err;
 931}
 932
 933static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
 934                              u16 vid)
 935{
 936        struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
 937        struct net_bridge_fdb_entry *fdb;
 938
 939        fdb = fdb_find(head, addr, vid);
 940        if (!fdb)
 941                return -ENOENT;
 942
 943        fdb_delete(br, fdb);
 944        return 0;
 945}
 946
 947static int __br_fdb_delete_by_addr(struct net_bridge *br,
 948                                   const unsigned char *addr, u16 vid)
 949{
 950        int err;
 951
 952        spin_lock_bh(&br->hash_lock);
 953        err = fdb_delete_by_addr(br, addr, vid);
 954        spin_unlock_bh(&br->hash_lock);
 955
 956        return err;
 957}
 958
 959static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 960                                       const u8 *addr, u16 vlan)
 961{
 962        struct net_bridge *br = p->br;
 963        struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)];
 964        struct net_bridge_fdb_entry *fdb;
 965
 966        fdb = fdb_find(head, addr, vlan);
 967        if (!fdb || fdb->dst != p)
 968                return -ENOENT;
 969
 970        fdb_delete(br, fdb);
 971        return 0;
 972}
 973
 974static int __br_fdb_delete(struct net_bridge_port *p,
 975                           const unsigned char *addr, u16 vid)
 976{
 977        int err;
 978
 979        spin_lock_bh(&p->br->hash_lock);
 980        err = fdb_delete_by_addr_and_port(p, addr, vid);
 981        spin_unlock_bh(&p->br->hash_lock);
 982
 983        return err;
 984}
 985
 986/* Remove neighbor entry with RTM_DELNEIGH */
 987int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 988                  struct net_device *dev,
 989                  const unsigned char *addr, u16 vid)
 990{
 991        struct net_bridge_vlan_group *vg;
 992        struct net_bridge_port *p = NULL;
 993        struct net_bridge_vlan *v;
 994        struct net_bridge *br = NULL;
 995        int err;
 996
 997        if (dev->priv_flags & IFF_EBRIDGE) {
 998                br = netdev_priv(dev);
 999                vg = br_vlan_group(br);
1000        } else {

1001                p = br_port_get_rtnl(dev);
1002                if (!p) {
1003                        pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
1004                                dev->name);
1005                        return -EINVAL;
1006                }
1007                vg = nbp_vlan_group(p);
1008        }
1009
1010        if (vid) {
1011                v = br_vlan_find(vg, vid);
1012                if (!v) {
1013                        pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
1014                        return -EINVAL;
1015                }
1016
1017                if (dev->priv_flags & IFF_EBRIDGE)
1018                        err = __br_fdb_delete_by_addr(br, addr, vid);
1019                else
1020                        err = __br_fdb_delete(p, addr, vid);
1021        } else {
1022                err = -ENOENT;
1023                if (dev->priv_flags & IFF_EBRIDGE)
1024                        err = __br_fdb_delete_by_addr(br, addr, 0);
1025                else
1026                        err &= __br_fdb_delete(p, addr, 0);
1027
1028                if (!vg || !vg->num_vlans)
1029                        goto out;
1030
1031                list_for_each_entry(v, &vg->vlan_list, vlist) {
1032                        if (!br_vlan_should_use(v))
1033                                continue;
1034                        if (dev->priv_flags & IFF_EBRIDGE)
1035                                err = __br_fdb_delete_by_addr(br, addr, v->vid);
1036                        else
1037                                err &= __br_fdb_delete(p, addr, v->vid);
1038                }
1039        }
1040out:
1041        return err;
1042}
1043
1044int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
1045{
1046        struct net_bridge_fdb_entry *fdb, *tmp;
1047        int i;
1048        int err;
1049
1050        ASSERT_RTNL();
1051
1052        for (i = 0; i < BR_HASH_SIZE; i++) {
1053                hlist_for_each_entry(fdb, &br->hash[i], hlist) {
1054                        /* We only care for static entries */
1055                        if (!fdb->is_static)
1056                                continue;
1057
1058                        err = dev_uc_add(p->dev, fdb->addr.addr);
1059                        if (err)
1060                                goto rollback;
1061                }
1062        }
1063        return 0;
1064
1065rollback:
1066        for (i = 0; i < BR_HASH_SIZE; i++) {
1067                hlist_for_each_entry(tmp, &br->hash[i], hlist) {
1068                        /* If we reached the fdb that failed, we can stop */
1069                        if (tmp == fdb)
1070                                break;
1071
1072                        /* We only care for static entries */
1073                        if (!tmp->is_static)
1074                                continue;
1075
1076                        dev_uc_del(p->dev, tmp->addr.addr);
1077                }
1078        }
1079        return err;
1080}
1081
1082void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
1083{
1084        struct net_bridge_fdb_entry *fdb;
1085        int i;
1086
1087        ASSERT_RTNL();
1088
1089        for (i = 0; i < BR_HASH_SIZE; i++) {
1090                hlist_for_each_entry_rcu(fdb, &br->hash[i], hlist) {
1091                        /* We only care for static entries */
1092                        if (!fdb->is_static)
1093                                continue;
1094
1095                        dev_uc_del(p->dev, fdb->addr.addr);
1096                }
1097        }
1098}
1099
1100int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
1101                              const unsigned char *addr, u16 vid)
1102{
1103        struct hlist_head *head;
1104        struct net_bridge_fdb_entry *fdb;
1105        int err = 0;
1106
1107        ASSERT_RTNL();
1108        spin_lock_bh(&br->hash_lock);
1109
1110        head = &br->hash[br_mac_hash(addr, vid)];
1111        fdb = fdb_find(head, addr, vid);
1112        if (!fdb) {
1113                fdb = fdb_create(head, p, addr, vid, 0, 0);
1114                if (!fdb) {
1115                        err = -ENOMEM;
1116                        goto err_unlock;
1117                }
1118                fdb->added_by_external_learn = 1;
1119                fdb_notify(br, fdb, RTM_NEWNEIGH);
1120        } else if (fdb->added_by_external_learn) {
1121                /* Refresh entry */
1122                fdb->updated = fdb->used = jiffies;
1123        } else if (!fdb->added_by_user) {
1124                /* Take over SW learned entry */
1125                fdb->added_by_external_learn = 1;
1126                fdb->updated = jiffies;
1127                fdb_notify(br, fdb, RTM_NEWNEIGH);
1128        }
1129
1130err_unlock:
1131        spin_unlock_bh(&br->hash_lock);
1132
1133        return err;
1134}
1135
1136int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
1137                              const unsigned char *addr, u16 vid)
1138{
1139        struct hlist_head *head;
1140        struct net_bridge_fdb_entry *fdb;
1141        int err = 0;
1142
1143        ASSERT_RTNL();
1144        spin_lock_bh(&br->hash_lock);
1145
1146        head = &br->hash[br_mac_hash(addr, vid)];
1147        fdb = fdb_find(head, addr, vid);
1148        if (fdb && fdb->added_by_external_learn)
1149                fdb_delete(br, fdb);
1150        else
1151                err = -ENOENT;
1152
1153        spin_unlock_bh(&br->hash_lock);
1154
1155        return err;
1156}
1157