drivers/net/bonding/bond_alb.c

   1 /*
   2  * Copyright(c) 1999 - 2004 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the
   6  * Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * The full GNU General Public License is included in this distribution in the
  18  * file called LICENSE.
  19  *
  20  */
  21
  22 #include <linux/skbuff.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/etherdevice.h>
  25 #include <linux/pkt_sched.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/slab.h>
  28 #include <linux/timer.h>
  29 #include <linux/ip.h>
  30 #include <linux/ipv6.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/if_ether.h>
  33 #include <linux/if_bonding.h>
  34 #include <linux/if_vlan.h>
  35 #include <linux/in.h>
  36 #include <net/ipx.h>
  37 #include <net/arp.h>
  38 #include <net/ipv6.h>
  39 #include <asm/byteorder.h>
  40 #include "bonding.h"
  41 #include "bond_alb.h"
  42
  43
  44
  45 #ifndef __long_aligned
  46 #define __long_aligned __attribute__((aligned((sizeof(long)))))
  47 #endif
  48 static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
  49         0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  50 };
  51 static const u8 mac_v6_allmcast[ETH_ALEN] __long_aligned = {
  52         0x33, 0x33, 0x00, 0x00, 0x00, 0x01
  53 };
  54 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
  55
  56 #pragma pack(1)
  57 struct learning_pkt {
  58         u8 mac_dst[ETH_ALEN];
  59         u8 mac_src[ETH_ALEN];
  60         __be16 type;
  61         u8 padding[ETH_ZLEN - ETH_HLEN];
  62 };
  63
  64 struct arp_pkt {
  65         __be16  hw_addr_space;
  66         __be16  prot_addr_space;
  67         u8      hw_addr_len;
  68         u8      prot_addr_len;
  69         __be16  op_code;
  70         u8      mac_src[ETH_ALEN];      /* sender hardware address */
  71         __be32  ip_src;                 /* sender IP address */
  72         u8      mac_dst[ETH_ALEN];      /* target hardware address */
  73         __be32  ip_dst;                 /* target IP address */
  74 };
  75 #pragma pack()
  76
  77 static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
  78 {
  79         return (struct arp_pkt *)skb_network_header(skb);
  80 }
  81
  82 /* Forward declaration */
  83 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
  84                                       bool strict_match);
  85 static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp);
  86 static void rlb_src_unlink(struct bonding *bond, u32 index);
  87 static void rlb_src_link(struct bonding *bond, u32 ip_src_hash,
  88                          u32 ip_dst_hash);
  89
  90 static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
  91 {
  92         int i;
  93         u8 hash = 0;
  94
  95         for (i = 0; i < hash_size; i++)
  96                 hash ^= hash_start[i];
  97
  98         return hash;
  99 }
 100
 101 /*********************** tlb specific functions ***************************/
 102
 103 static inline void _lock_tx_hashtbl_bh(struct bonding *bond)
 104 {
 105         spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 106 }
 107
 108 static inline void _unlock_tx_hashtbl_bh(struct bonding *bond)
 109 {
 110         spin_unlock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 111 }
 112
 113 static inline void _lock_tx_hashtbl(struct bonding *bond)
 114 {
 115         spin_lock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 116 }
 117
 118 static inline void _unlock_tx_hashtbl(struct bonding *bond)
 119 {
 120         spin_unlock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 121 }
 122
 123 /* Caller must hold tx_hashtbl lock */
 124 static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
 125 {
 126         if (save_load) {
 127                 entry->load_history = 1 + entry->tx_bytes /
 128                                       BOND_TLB_REBALANCE_INTERVAL;
 129                 entry->tx_bytes = 0;
 130         }
 131
 132         entry->tx_slave = NULL;
 133         entry->next = TLB_NULL_INDEX;
 134         entry->prev = TLB_NULL_INDEX;
 135 }
 136
 137 static inline void tlb_init_slave(struct slave *slave)
 138 {
 139         SLAVE_TLB_INFO(slave).load = 0;
 140         SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
 141 }
 142
 143 /* Caller must hold bond lock for read, BH disabled */
 144 static void __tlb_clear_slave(struct bonding *bond, struct slave *slave,
 145                          int save_load)
 146 {
 147         struct tlb_client_info *tx_hash_table;
 148         u32 index;
 149
 150         /* clear slave from tx_hashtbl */
 151         tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;
 152
 153         /* skip this if we've already freed the tx hash table */
 154         if (tx_hash_table) {
 155                 index = SLAVE_TLB_INFO(slave).head;
 156                 while (index != TLB_NULL_INDEX) {
 157                         u32 next_index = tx_hash_table[index].next;
 158                         tlb_init_table_entry(&tx_hash_table[index], save_load);
 159                         index = next_index;
 160                 }
 161         }
 162
 163         tlb_init_slave(slave);
 164 }
 165
 166 /* Caller must hold bond lock for read */
 167 static void tlb_clear_slave(struct bonding *bond, struct slave *slave,
 168                          int save_load)
 169 {
 170         _lock_tx_hashtbl_bh(bond);
 171         __tlb_clear_slave(bond, slave, save_load);
 172         _unlock_tx_hashtbl_bh(bond);
 173 }
 174
 175 /* Must be called before starting the monitor timer */
 176 static int tlb_initialize(struct bonding *bond)
 177 {
 178         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 179         int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
 180         struct tlb_client_info *new_hashtbl;
 181         int i;
 182
 183         new_hashtbl = kzalloc(size, GFP_KERNEL);
 184         if (!new_hashtbl)
 185                 return -1;
 186
 187         _lock_tx_hashtbl_bh(bond);
 188
 189         bond_info->tx_hashtbl = new_hashtbl;
 190
 191         for (i = 0; i < TLB_HASH_TABLE_SIZE; i++)
 192                 tlb_init_table_entry(&bond_info->tx_hashtbl[i], 0);
 193
 194         _unlock_tx_hashtbl_bh(bond);
 195
 196         return 0;
 197 }
 198
 199 /* Must be called only after all slaves have been released */
 200 static void tlb_deinitialize(struct bonding *bond)
 201 {
 202         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 203         struct tlb_up_slave *arr;
 204
 205         _lock_tx_hashtbl_bh(bond);
 206
 207         kfree(bond_info->tx_hashtbl);
 208         bond_info->tx_hashtbl = NULL;
 209
 210         _unlock_tx_hashtbl_bh(bond);
 211
 212         arr = rtnl_dereference(bond_info->slave_arr);
 213         if (arr)
 214                 kfree_rcu(arr, rcu);
 215 }
 216
 217 static long long compute_gap(struct slave *slave)
 218 {
 219         return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
 220                (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
 221 }
 222
 223 /* Caller must hold bond lock for read */
 224 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
 225 {
 226         struct slave *slave, *least_loaded;
 227         struct list_head *iter;
 228         long long max_gap;
 229
 230         least_loaded = NULL;
 231         max_gap = LLONG_MIN;
 232
 233         /* Find the slave with the largest gap */
 234         bond_for_each_slave_rcu(bond, slave, iter) {
 235                 if (bond_slave_can_tx(slave)) {
 236                         long long gap = compute_gap(slave);
 237
 238                         if (max_gap < gap) {
 239                                 least_loaded = slave;
 240                                 max_gap = gap;
 241                         }
 242                 }
 243         }
 244
 245         return least_loaded;
 246 }
 247
 248 static struct slave *__tlb_choose_channel(struct bonding *bond, u32 hash_index,
 249                                                 u32 skb_len)
 250 {
 251         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 252         struct tlb_client_info *hash_table;
 253         struct slave *assigned_slave;
 254
 255         hash_table = bond_info->tx_hashtbl;
 256         assigned_slave = hash_table[hash_index].tx_slave;
 257         if (!assigned_slave) {
 258                 assigned_slave = tlb_get_least_loaded_slave(bond);
 259
 260                 if (assigned_slave) {
 261                         struct tlb_slave_info *slave_info =
 262                                 &(SLAVE_TLB_INFO(assigned_slave));
 263                         u32 next_index = slave_info->head;
 264
 265                         hash_table[hash_index].tx_slave = assigned_slave;
 266                         hash_table[hash_index].next = next_index;
 267                         hash_table[hash_index].prev = TLB_NULL_INDEX;
 268
 269                         if (next_index != TLB_NULL_INDEX)
 270                                 hash_table[next_index].prev = hash_index;
 271
 272                         slave_info->head = hash_index;
 273                         slave_info->load +=
 274                                 hash_table[hash_index].load_history;
 275                 }
 276         }
 277
 278         if (assigned_slave)
 279                 hash_table[hash_index].tx_bytes += skb_len;
 280
 281         return assigned_slave;
 282 }
 283
 284 /* Caller must hold bond lock for read */
 285 static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index,
 286                                         u32 skb_len)
 287 {
 288         struct slave *tx_slave;
 289         /*
 290          * We don't need to disable softirq here, becase
 291          * tlb_choose_channel() is only called by bond_alb_xmit()
 292          * which already has softirq disabled.
 293          */
 294         _lock_tx_hashtbl(bond);
 295         tx_slave = __tlb_choose_channel(bond, hash_index, skb_len);
 296         _unlock_tx_hashtbl(bond);
 297         return tx_slave;
 298 }
 299
 300 /*********************** rlb specific functions ***************************/
 301 static inline void _lock_rx_hashtbl_bh(struct bonding *bond)
 302 {
 303         spin_lock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 304 }
 305
 306 static inline void _unlock_rx_hashtbl_bh(struct bonding *bond)
 307 {
 308         spin_unlock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 309 }
 310
 311 static inline void _lock_rx_hashtbl(struct bonding *bond)
 312 {
 313         spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 314 }
 315
 316 static inline void _unlock_rx_hashtbl(struct bonding *bond)
 317 {
 318         spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 319 }
 320
 321 /* when an ARP REPLY is received from a client update its info
 322  * in the rx_hashtbl
 323  */
 324 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
 325 {
 326         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 327         struct rlb_client_info *client_info;
 328         u32 hash_index;
 329
 330         _lock_rx_hashtbl_bh(bond);
 331
 332         hash_index = _simple_hash((u8 *)&(arp->ip_src), sizeof(arp->ip_src));
 333         client_info = &(bond_info->rx_hashtbl[hash_index]);
 334
 335         if ((client_info->assigned) &&
 336             (client_info->ip_src == arp->ip_dst) &&
 337             (client_info->ip_dst == arp->ip_src) &&
 338             (!ether_addr_equal_64bits(client_info->mac_dst, arp->mac_src))) {
 339                 /* update the clients MAC address */
 340                 ether_addr_copy(client_info->mac_dst, arp->mac_src);
 341                 client_info->ntt = 1;
 342                 bond_info->rx_ntt = 1;
 343         }
 344
 345         _unlock_rx_hashtbl_bh(bond);
 346 }
 347
 348 static int rlb_arp_recv(const struct sk_buff *skb, struct bonding *bond,
 349                         struct slave *slave)
 350 {
 351         struct arp_pkt *arp, _arp;
 352
 353         if (skb->protocol != cpu_to_be16(ETH_P_ARP))
 354                 goto out;
 355
 356         arp = skb_header_pointer(skb, 0, sizeof(_arp), &_arp);
 357         if (!arp)
 358                 goto out;
 359
 360         /* We received an ARP from arp->ip_src.
 361          * We might have used this IP address previously (on the bonding host
 362          * itself or on a system that is bridged together with the bond).
 363          * However, if arp->mac_src is different than what is stored in
 364          * rx_hashtbl, some other host is now using the IP and we must prevent
 365          * sending out client updates with this IP address and the old MAC
 366          * address.
 367          * Clean up all hash table entries that have this address as ip_src but
 368          * have a different mac_src.
 369          */
 370         rlb_purge_src_ip(bond, arp);
 371
 372         if (arp->op_code == htons(ARPOP_REPLY)) {
 373                 /* update rx hash table for this ARP */
 374                 rlb_update_entry_from_arp(bond, arp);
 375                 netdev_dbg(bond->dev, "Server received an ARP Reply from client\n");
 376         }
 377 out:
 378         return RX_HANDLER_ANOTHER;
 379 }
 380
 381 /* Caller must hold bond lock for read */
 382 static struct slave *rlb_next_rx_slave(struct bonding *bond)
 383 {
 384         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 385         struct slave *before = NULL, *rx_slave = NULL, *slave;
 386         struct list_head *iter;
 387         bool found = false;
 388
 389         bond_for_each_slave(bond, slave, iter) {
 390                 if (!bond_slave_can_tx(slave))
 391                         continue;
 392                 if (!found) {
 393                         if (!before || before->speed < slave->speed)
 394                                 before = slave;
 395                 } else {
 396                         if (!rx_slave || rx_slave->speed < slave->speed)
 397                                 rx_slave = slave;
 398                 }
 399                 if (slave == bond_info->rx_slave)
 400                         found = true;
 401         }
 402         /* we didn't find anything after the current or we have something
 403          * better before and up to the current slave
 404          */
 405         if (!rx_slave || (before && rx_slave->speed < before->speed))
 406                 rx_slave = before;
 407
 408         if (rx_slave)
 409                 bond_info->rx_slave = rx_slave;
 410
 411         return rx_slave;
 412 }
 413
 414 /* Caller must hold rcu_read_lock() for read */
 415 static struct slave *__rlb_next_rx_slave(struct bonding *bond)
 416 {
 417         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 418         struct slave *before = NULL, *rx_slave = NULL, *slave;
 419         struct list_head *iter;
 420         bool found = false;
 421
 422         bond_for_each_slave_rcu(bond, slave, iter) {
 423                 if (!bond_slave_can_tx(slave))
 424                         continue;
 425                 if (!found) {
 426                         if (!before || before->speed < slave->speed)
 427                                 before = slave;
 428                 } else {
 429                         if (!rx_slave || rx_slave->speed < slave->speed)
 430                                 rx_slave = slave;
 431                 }
 432                 if (slave == bond_info->rx_slave)
 433                         found = true;
 434         }
 435         /* we didn't find anything after the current or we have something
 436          * better before and up to the current slave
 437          */
 438         if (!rx_slave || (before && rx_slave->speed < before->speed))
 439                 rx_slave = before;
 440
 441         if (rx_slave)
 442                 bond_info->rx_slave = rx_slave;
 443
 444         return rx_slave;
 445 }
 446
 447 /* teach the switch the mac of a disabled slave
 448  * on the primary for fault tolerance
 449  *
 450  * Caller must hold bond->curr_slave_lock for write or bond lock for write
 451  */
 452 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
 453 {
 454         struct slave *curr_active = bond_deref_active_protected(bond);
 455
 456         if (!curr_active)
 457                 return;
 458
 459         if (!bond->alb_info.primary_is_promisc) {
 460                 if (!dev_set_promiscuity(curr_active->dev, 1))
 461                         bond->alb_info.primary_is_promisc = 1;
 462                 else
 463                         bond->alb_info.primary_is_promisc = 0;
 464         }
 465
 466         bond->alb_info.rlb_promisc_timeout_counter = 0;
 467
 468         alb_send_learning_packets(curr_active, addr, true);
 469 }
 470
 471 /* slave being removed should not be active at this point
 472  *
 473  * Caller must hold rtnl.
 474  */
 475 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
 476 {
 477         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 478         struct rlb_client_info *rx_hash_table;
 479         u32 index, next_index;
 480
 481         /* clear slave from rx_hashtbl */
 482         _lock_rx_hashtbl_bh(bond);
 483
 484         rx_hash_table = bond_info->rx_hashtbl;
 485         index = bond_info->rx_hashtbl_used_head;
 486         for (; index != RLB_NULL_INDEX; index = next_index) {
 487                 next_index = rx_hash_table[index].used_next;
 488                 if (rx_hash_table[index].slave == slave) {
 489                         struct slave *assigned_slave = rlb_next_rx_slave(bond);
 490
 491                         if (assigned_slave) {
 492                                 rx_hash_table[index].slave = assigned_slave;
 493                                 if (!ether_addr_equal_64bits(rx_hash_table[index].mac_dst,
 494                                                              mac_bcast)) {
 495                                         bond_info->rx_hashtbl[index].ntt = 1;
 496                                         bond_info->rx_ntt = 1;
 497                                         /* A slave has been removed from the
 498                                          * table because it is either disabled
 499                                          * or being released. We must retry the
 500                                          * update to avoid clients from not
 501                                          * being updated & disconnecting when
 502                                          * there is stress
 503                                          */
 504                                         bond_info->rlb_update_retry_counter =
 505                                                 RLB_UPDATE_RETRY;
 506                                 }
 507                         } else {  /* there is no active slave */
 508                                 rx_hash_table[index].slave = NULL;
 509                         }
 510                 }
 511         }
 512
 513         _unlock_rx_hashtbl_bh(bond);
 514
 515         write_lock_bh(&bond->curr_slave_lock);
 516
 517         if (slave != bond_deref_active_protected(bond))
 518                 rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
 519
 520         write_unlock_bh(&bond->curr_slave_lock);
 521 }
 522
 523 static void rlb_update_client(struct rlb_client_info *client_info)
 524 {
 525         int i;
 526
 527         if (!client_info->slave)
 528                 return;
 529
 530         for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
 531                 struct sk_buff *skb;
 532
 533                 skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
 534                                  client_info->ip_dst,
 535                                  client_info->slave->dev,
 536                                  client_info->ip_src,
 537                                  client_info->mac_dst,
 538                                  client_info->slave->dev->dev_addr,
 539                                  client_info->mac_dst);
 540                 if (!skb) {
 541                         netdev_err(client_info->slave->bond->dev,
 542                                    "failed to create an ARP packet\n");
 543                         continue;
 544                 }
 545
 546                 skb->dev = client_info->slave->dev;
 547
 548                 if (client_info->vlan_id) {
 549                         skb = vlan_put_tag(skb, htons(ETH_P_8021Q), client_info->vlan_id);
 550                         if (!skb) {
 551                                 netdev_err(client_info->slave->bond->dev,
 552                                            "failed to insert VLAN tag\n");
 553                                 continue;
 554                         }
 555                 }
 556
 557                 arp_xmit(skb);
 558         }
 559 }
 560
 561 /* sends ARP REPLIES that update the clients that need updating */
 562 static void rlb_update_rx_clients(struct bonding *bond)
 563 {
 564         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 565         struct rlb_client_info *client_info;
 566         u32 hash_index;
 567
 568         _lock_rx_hashtbl_bh(bond);
 569
 570         hash_index = bond_info->rx_hashtbl_used_head;
 571         for (; hash_index != RLB_NULL_INDEX;
 572              hash_index = client_info->used_next) {
 573                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 574                 if (client_info->ntt) {
 575                         rlb_update_client(client_info);
 576                         if (bond_info->rlb_update_retry_counter == 0)
 577                                 client_info->ntt = 0;
 578                 }
 579         }
 580
 581         /* do not update the entries again until this counter is zero so that
 582          * not to confuse the clients.
 583          */
 584         bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
 585
 586         _unlock_rx_hashtbl_bh(bond);
 587 }
 588
 589 /* The slave was assigned a new mac address - update the clients */
 590 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
 591 {
 592         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 593         struct rlb_client_info *client_info;
 594         int ntt = 0;
 595         u32 hash_index;
 596
 597         _lock_rx_hashtbl_bh(bond);
 598
 599         hash_index = bond_info->rx_hashtbl_used_head;
 600         for (; hash_index != RLB_NULL_INDEX;
 601              hash_index = client_info->used_next) {
 602                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 603
 604                 if ((client_info->slave == slave) &&
 605                     !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
 606                         client_info->ntt = 1;
 607                         ntt = 1;
 608                 }
 609         }
 610
 611         /* update the team's flag only after the whole iteration */
 612         if (ntt) {
 613                 bond_info->rx_ntt = 1;
 614                 /* fasten the change */
 615                 bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
 616         }
 617
 618         _unlock_rx_hashtbl_bh(bond);
 619 }
 620
 621 /* mark all clients using src_ip to be updated */
 622 static void rlb_req_update_subnet_clients(struct bonding *bond, __be32 src_ip)
 623 {
 624         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 625         struct rlb_client_info *client_info;
 626         u32 hash_index;
 627
 628         _lock_rx_hashtbl(bond);
 629
 630         hash_index = bond_info->rx_hashtbl_used_head;
 631         for (; hash_index != RLB_NULL_INDEX;
 632              hash_index = client_info->used_next) {
 633                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 634
 635                 if (!client_info->slave) {
 636                         netdev_err(bond->dev, "found a client with no channel in the client's hash table\n");
 637                         continue;
 638                 }
 639                 /*update all clients using this src_ip, that are not assigned
 640                  * to the team's address (curr_active_slave) and have a known
 641                  * unicast mac address.
 642                  */
 643                 if ((client_info->ip_src == src_ip) &&
 644                     !ether_addr_equal_64bits(client_info->slave->dev->dev_addr,
 645                                              bond->dev->dev_addr) &&
 646                     !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
 647                         client_info->ntt = 1;
 648                         bond_info->rx_ntt = 1;
 649                 }
 650         }
 651
 652         _unlock_rx_hashtbl(bond);
 653 }
 654
 655 /* Caller must hold both bond and ptr locks for read */
 656 static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
 657 {
 658         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 659         struct arp_pkt *arp = arp_pkt(skb);
 660         struct slave *assigned_slave, *curr_active_slave;
 661         struct rlb_client_info *client_info;
 662         u32 hash_index = 0;
 663
 664         _lock_rx_hashtbl(bond);
 665
 666         curr_active_slave = rcu_dereference(bond->curr_active_slave);
 667
 668         hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_dst));
 669         client_info = &(bond_info->rx_hashtbl[hash_index]);
 670
 671         if (client_info->assigned) {
 672                 if ((client_info->ip_src == arp->ip_src) &&
 673                     (client_info->ip_dst == arp->ip_dst)) {
 674                         /* the entry is already assigned to this client */
 675                         if (!ether_addr_equal_64bits(arp->mac_dst, mac_bcast)) {
 676                                 /* update mac address from arp */
 677                                 ether_addr_copy(client_info->mac_dst, arp->mac_dst);
 678                         }
 679                         ether_addr_copy(client_info->mac_src, arp->mac_src);
 680
 681                         assigned_slave = client_info->slave;
 682                         if (assigned_slave) {
 683                                 _unlock_rx_hashtbl(bond);
 684                                 return assigned_slave;
 685                         }
 686                 } else {
 687                         /* the entry is already assigned to some other client,
 688                          * move the old client to primary (curr_active_slave) so
 689                          * that the new client can be assigned to this entry.
 690                          */
 691                         if (curr_active_slave &&
 692                             client_info->slave != curr_active_slave) {
 693                                 client_info->slave = curr_active_slave;
 694                                 rlb_update_client(client_info);
 695                         }
 696                 }
 697         }
 698         /* assign a new slave */
 699         assigned_slave = __rlb_next_rx_slave(bond);
 700
 701         if (assigned_slave) {
 702                 if (!(client_info->assigned &&
 703                       client_info->ip_src == arp->ip_src)) {
 704                         /* ip_src is going to be updated,
 705                          * fix the src hash list
 706                          */
 707                         u32 hash_src = _simple_hash((u8 *)&arp->ip_src,
 708                                                     sizeof(arp->ip_src));
 709                         rlb_src_unlink(bond, hash_index);
 710                         rlb_src_link(bond, hash_src, hash_index);
 711                 }
 712
 713                 client_info->ip_src = arp->ip_src;
 714                 client_info->ip_dst = arp->ip_dst;
 715                 /* arp->mac_dst is broadcast for arp reqeusts.
 716                  * will be updated with clients actual unicast mac address
 717                  * upon receiving an arp reply.
 718                  */
 719                 ether_addr_copy(client_info->mac_dst, arp->mac_dst);
 720                 ether_addr_copy(client_info->mac_src, arp->mac_src);
 721                 client_info->slave = assigned_slave;
 722
 723                 if (!ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
 724                         client_info->ntt = 1;
 725                         bond->alb_info.rx_ntt = 1;
 726                 } else {
 727                         client_info->ntt = 0;
 728                 }
 729
 730                 if (vlan_get_tag(skb, &client_info->vlan_id))
 731                         client_info->vlan_id = 0;
 732
 733                 if (!client_info->assigned) {
 734                         u32 prev_tbl_head = bond_info->rx_hashtbl_used_head;
 735                         bond_info->rx_hashtbl_used_head = hash_index;
 736                         client_info->used_next = prev_tbl_head;
 737                         if (prev_tbl_head != RLB_NULL_INDEX) {
 738                                 bond_info->rx_hashtbl[prev_tbl_head].used_prev =
 739                                         hash_index;
 740                         }
 741                         client_info->assigned = 1;
 742                 }
 743         }
 744
 745         _unlock_rx_hashtbl(bond);
 746
 747         return assigned_slave;
 748 }
 749
 750 /* chooses (and returns) transmit channel for arp reply
 751  * does not choose channel for other arp types since they are
 752  * sent on the curr_active_slave
 753  */
 754 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
 755 {
 756         struct arp_pkt *arp = arp_pkt(skb);
 757         struct slave *tx_slave = NULL;
 758
 759         /* Don't modify or load balance ARPs that do not originate locally
 760          * (e.g.,arrive via a bridge).
 761          */
 762         if (!bond_slave_has_mac_rx(bond, arp->mac_src))
 763                 return NULL;
 764
 765         if (arp->op_code == htons(ARPOP_REPLY)) {
 766                 /* the arp must be sent on the selected
 767                 * rx channel
 768                 */
 769                 tx_slave = rlb_choose_channel(skb, bond);
 770                 if (tx_slave)
 771                         ether_addr_copy(arp->mac_src, tx_slave->dev->dev_addr);
 772                 netdev_dbg(bond->dev, "Server sent ARP Reply packet\n");
 773         } else if (arp->op_code == htons(ARPOP_REQUEST)) {
 774                 /* Create an entry in the rx_hashtbl for this client as a
 775                  * place holder.
 776                  * When the arp reply is received the entry will be updated
 777                  * with the correct unicast address of the client.
 778                  */
 779                 rlb_choose_channel(skb, bond);
 780
 781                 /* The ARP reply packets must be delayed so that
 782                  * they can cancel out the influence of the ARP request.
 783                  */
 784                 bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
 785
 786                 /* arp requests are broadcast and are sent on the primary
 787                  * the arp request will collapse all clients on the subnet to
 788                  * the primary slave. We must register these clients to be
 789                  * updated with their assigned mac.
 790                  */
 791                 rlb_req_update_subnet_clients(bond, arp->ip_src);
 792                 netdev_dbg(bond->dev, "Server sent ARP Request packet\n");
 793         }
 794
 795         return tx_slave;
 796 }
 797
 798 /* Caller must hold bond lock for read */
 799 static void rlb_rebalance(struct bonding *bond)
 800 {
 801         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 802         struct slave *assigned_slave;
 803         struct rlb_client_info *client_info;
 804         int ntt;
 805         u32 hash_index;
 806
 807         _lock_rx_hashtbl_bh(bond);
 808
 809         ntt = 0;
 810         hash_index = bond_info->rx_hashtbl_used_head;
 811         for (; hash_index != RLB_NULL_INDEX;
 812              hash_index = client_info->used_next) {
 813                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 814                 assigned_slave = __rlb_next_rx_slave(bond);
 815                 if (assigned_slave && (client_info->slave != assigned_slave)) {
 816                         client_info->slave = assigned_slave;
 817                         client_info->ntt = 1;
 818                         ntt = 1;
 819                 }
 820         }
 821
 822         /* update the team's flag only after the whole iteration */
 823         if (ntt)
 824                 bond_info->rx_ntt = 1;
 825         _unlock_rx_hashtbl_bh(bond);
 826 }
 827
 828 /* Caller must hold rx_hashtbl lock */
 829 static void rlb_init_table_entry_dst(struct rlb_client_info *entry)
 830 {
 831         entry->used_next = RLB_NULL_INDEX;
 832         entry->used_prev = RLB_NULL_INDEX;
 833         entry->assigned = 0;
 834         entry->slave = NULL;
 835         entry->vlan_id = 0;
 836 }
 837 static void rlb_init_table_entry_src(struct rlb_client_info *entry)
 838 {
 839         entry->src_first = RLB_NULL_INDEX;
 840         entry->src_prev = RLB_NULL_INDEX;
 841         entry->src_next = RLB_NULL_INDEX;
 842 }
 843
 844 static void rlb_init_table_entry(struct rlb_client_info *entry)
 845 {
 846         memset(entry, 0, sizeof(struct rlb_client_info));
 847         rlb_init_table_entry_dst(entry);
 848         rlb_init_table_entry_src(entry);
 849 }
 850
 851 static void rlb_delete_table_entry_dst(struct bonding *bond, u32 index)
 852 {
 853         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 854         u32 next_index = bond_info->rx_hashtbl[index].used_next;
 855         u32 prev_index = bond_info->rx_hashtbl[index].used_prev;
 856
 857         if (index == bond_info->rx_hashtbl_used_head)
 858                 bond_info->rx_hashtbl_used_head = next_index;
 859         if (prev_index != RLB_NULL_INDEX)
 860                 bond_info->rx_hashtbl[prev_index].used_next = next_index;
 861         if (next_index != RLB_NULL_INDEX)
 862                 bond_info->rx_hashtbl[next_index].used_prev = prev_index;
 863 }
 864
 865 /* unlink a rlb hash table entry from the src list */
 866 static void rlb_src_unlink(struct bonding *bond, u32 index)
 867 {
 868         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 869         u32 next_index = bond_info->rx_hashtbl[index].src_next;
 870         u32 prev_index = bond_info->rx_hashtbl[index].src_prev;
 871
 872         bond_info->rx_hashtbl[index].src_next = RLB_NULL_INDEX;
 873         bond_info->rx_hashtbl[index].src_prev = RLB_NULL_INDEX;
 874
 875         if (next_index != RLB_NULL_INDEX)
 876                 bond_info->rx_hashtbl[next_index].src_prev = prev_index;
 877
 878         if (prev_index == RLB_NULL_INDEX)
 879                 return;
 880
 881         /* is prev_index pointing to the head of this list? */
 882         if (bond_info->rx_hashtbl[prev_index].src_first == index)
 883                 bond_info->rx_hashtbl[prev_index].src_first = next_index;
 884         else
 885                 bond_info->rx_hashtbl[prev_index].src_next = next_index;
 886
 887 }
 888
 889 static void rlb_delete_table_entry(struct bonding *bond, u32 index)
 890 {
 891         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 892         struct rlb_client_info *entry = &(bond_info->rx_hashtbl[index]);
 893
 894         rlb_delete_table_entry_dst(bond, index);
 895         rlb_init_table_entry_dst(entry);
 896
 897         rlb_src_unlink(bond, index);
 898 }
 899
 900 /* add the rx_hashtbl[ip_dst_hash] entry to the list
 901  * of entries with identical ip_src_hash
 902  */
 903 static void rlb_src_link(struct bonding *bond, u32 ip_src_hash, u32 ip_dst_hash)
 904 {
 905         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 906         u32 next;
 907
 908         bond_info->rx_hashtbl[ip_dst_hash].src_prev = ip_src_hash;
 909         next = bond_info->rx_hashtbl[ip_src_hash].src_first;
 910         bond_info->rx_hashtbl[ip_dst_hash].src_next = next;
 911         if (next != RLB_NULL_INDEX)
 912                 bond_info->rx_hashtbl[next].src_prev = ip_dst_hash;
 913         bond_info->rx_hashtbl[ip_src_hash].src_first = ip_dst_hash;
 914 }
 915
 916 /* deletes all rx_hashtbl entries with  arp->ip_src if their mac_src does
 917  * not match arp->mac_src */
 918 static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp)
 919 {
 920         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 921         u32 ip_src_hash = _simple_hash((u8 *)&(arp->ip_src), sizeof(arp->ip_src));
 922         u32 index;
 923
 924         _lock_rx_hashtbl_bh(bond);
 925
 926         index = bond_info->rx_hashtbl[ip_src_hash].src_first;
 927         while (index != RLB_NULL_INDEX) {
 928                 struct rlb_client_info *entry = &(bond_info->rx_hashtbl[index]);
 929                 u32 next_index = entry->src_next;
 930                 if (entry->ip_src == arp->ip_src &&
 931                     !ether_addr_equal_64bits(arp->mac_src, entry->mac_src))
 932                                 rlb_delete_table_entry(bond, index);
 933                 index = next_index;
 934         }
 935         _unlock_rx_hashtbl_bh(bond);
 936 }
 937
 938 static int rlb_initialize(struct bonding *bond)
 939 {
 940         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 941         struct rlb_client_info  *new_hashtbl;
 942         int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
 943         int i;
 944
 945         new_hashtbl = kmalloc(size, GFP_KERNEL);
 946         if (!new_hashtbl)
 947                 return -1;
 948
 949         _lock_rx_hashtbl_bh(bond);
 950
 951         bond_info->rx_hashtbl = new_hashtbl;
 952
 953         bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
 954
 955         for (i = 0; i < RLB_HASH_TABLE_SIZE; i++)
 956                 rlb_init_table_entry(bond_info->rx_hashtbl + i);
 957
 958         _unlock_rx_hashtbl_bh(bond);
 959
 960         /* register to receive ARPs */
 961         bond->recv_probe = rlb_arp_recv;
 962
 963         return 0;
 964 }
 965
 966 static void rlb_deinitialize(struct bonding *bond)
 967 {
 968         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 969
 970         _lock_rx_hashtbl_bh(bond);
 971
 972         kfree(bond_info->rx_hashtbl);
 973         bond_info->rx_hashtbl = NULL;
 974         bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
 975
 976         _unlock_rx_hashtbl_bh(bond);
 977 }
 978
 979 static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
 980 {
 981         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 982         u32 curr_index;
 983
 984         _lock_rx_hashtbl_bh(bond);
 985
 986         curr_index = bond_info->rx_hashtbl_used_head;
 987         while (curr_index != RLB_NULL_INDEX) {
 988                 struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
 989                 u32 next_index = bond_info->rx_hashtbl[curr_index].used_next;
 990
 991                 if (curr->vlan_id == vlan_id)
 992                         rlb_delete_table_entry(bond, curr_index);
 993
 994                 curr_index = next_index;
 995         }
 996
 997         _unlock_rx_hashtbl_bh(bond);
 998 }
 999
1000 /*********************** tlb/rlb shared functions *********************/
1001
1002 static void alb_send_lp_vid(struct slave *slave, u8 mac_addr[],
1003                             __be16 vlan_proto, u16 vid)
1004 {
1005         struct learning_pkt pkt;
1006         struct sk_buff *skb;
1007         int size = sizeof(struct learning_pkt);
1008         char *data;
1009
1010         memset(&pkt, 0, size);
1011         ether_addr_copy(pkt.mac_dst, mac_addr);
1012         ether_addr_copy(pkt.mac_src, mac_addr);
1013         pkt.type = cpu_to_be16(ETH_P_LOOPBACK);
1014
1015         skb = dev_alloc_skb(size);
1016         if (!skb)
1017                 return;
1018
1019         data = skb_put(skb, size);
1020         memcpy(data, &pkt, size);
1021
1022         skb_reset_mac_header(skb);
1023         skb->network_header = skb->mac_header + ETH_HLEN;
1024         skb->protocol = pkt.type;
1025         skb->priority = TC_PRIO_CONTROL;
1026         skb->dev = slave->dev;
1027
1028         if (vid) {
1029                 skb = vlan_put_tag(skb, vlan_proto, vid);
1030                 if (!skb) {
1031                         netdev_err(slave->bond->dev, "failed to insert VLAN tag\n");
1032                         return;
1033                 }
1034         }
1035
1036         dev_queue_xmit(skb);
1037 }
1038
1039 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
1040                                       bool strict_match)
1041 {
1042         struct bonding *bond = bond_get_bond_by_slave(slave);
1043         struct net_device *upper;
1044         struct list_head *iter;
1045         struct bond_vlan_tag tags[BOND_MAX_VLAN_ENCAP];
1046
1047         /* send untagged */
1048         alb_send_lp_vid(slave, mac_addr, 0, 0);
1049
1050         /* loop through all devices and see if we need to send a packet
1051          * for that device.
1052          */
1053         rcu_read_lock();
1054         netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
1055                 if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0) {
1056                         if (strict_match &&
1057                             ether_addr_equal_64bits(mac_addr,
1058                                                     upper->dev_addr)) {
1059                                 alb_send_lp_vid(slave, mac_addr,
1060                                                 vlan_dev_vlan_proto(upper),
1061                                                 vlan_dev_vlan_id(upper));
1062                         } else if (!strict_match) {
1063                                 alb_send_lp_vid(slave, upper->dev_addr,
1064                                                 vlan_dev_vlan_proto(upper),
1065                                                 vlan_dev_vlan_id(upper));
1066                         }
1067                 }
1068
1069                 /* If this is a macvlan device, then only send updates
1070                  * when strict_match is turned off.
1071                  */
1072                 if (netif_is_macvlan(upper) && !strict_match) {
1073                         memset(tags, 0, sizeof(tags));
1074                         bond_verify_device_path(bond->dev, upper, tags);
1075                         alb_send_lp_vid(slave, upper->dev_addr,
1076                                         tags[0].vlan_proto, tags[0].vlan_id);
1077                 }
1078         }
1079         rcu_read_unlock();
1080 }
1081
1082 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[])
1083 {
1084         struct net_device *dev = slave->dev;
1085         struct sockaddr s_addr;
1086
1087         if (BOND_MODE(slave->bond) == BOND_MODE_TLB) {
1088                 memcpy(dev->dev_addr, addr, dev->addr_len);
1089                 return 0;
1090         }
1091
1092         /* for rlb each slave must have a unique hw mac addresses so that */
1093         /* each slave will receive packets destined to a different mac */
1094         memcpy(s_addr.sa_data, addr, dev->addr_len);
1095         s_addr.sa_family = dev->type;
1096         if (dev_set_mac_address(dev, &s_addr)) {
1097                 netdev_err(slave->bond->dev, "dev_set_mac_address of dev %s failed! ALB mode requires that the base driver support setting the hw address also when the network device's interface is open\n",
1098                            dev->name);
1099                 return -EOPNOTSUPP;
1100         }
1101         return 0;
1102 }
1103
1104 /*
1105  * Swap MAC addresses between two slaves.
1106  *
1107  * Called with RTNL held, and no other locks.
1108  *
1109  */
1110
1111 static void alb_swap_mac_addr(struct slave *slave1, struct slave *slave2)
1112 {
1113         u8 tmp_mac_addr[ETH_ALEN];
1114
1115         ether_addr_copy(tmp_mac_addr, slave1->dev->dev_addr);
1116         alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr);
1117         alb_set_slave_mac_addr(slave2, tmp_mac_addr);
1118
1119 }
1120
1121 /*
1122  * Send learning packets after MAC address swap.
1123  *
1124  * Called with RTNL and no other locks
1125  */
1126 static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
1127                                 struct slave *slave2)
1128 {
1129         int slaves_state_differ = (bond_slave_can_tx(slave1) != bond_slave_can_tx(slave2));
1130         struct slave *disabled_slave = NULL;
1131
1132         ASSERT_RTNL();
1133
1134         /* fasten the change in the switch */
1135         if (bond_slave_can_tx(slave1)) {
1136                 alb_send_learning_packets(slave1, slave1->dev->dev_addr, false);
1137                 if (bond->alb_info.rlb_enabled) {
1138                         /* inform the clients that the mac address
1139                          * has changed
1140                          */
1141                         rlb_req_update_slave_clients(bond, slave1);
1142                 }
1143         } else {
1144                 disabled_slave = slave1;
1145         }
1146
1147         if (bond_slave_can_tx(slave2)) {
1148                 alb_send_learning_packets(slave2, slave2->dev->dev_addr, false);
1149                 if (bond->alb_info.rlb_enabled) {
1150                         /* inform the clients that the mac address
1151                          * has changed
1152                          */
1153                         rlb_req_update_slave_clients(bond, slave2);
1154                 }
1155         } else {
1156                 disabled_slave = slave2;
1157         }
1158
1159         if (bond->alb_info.rlb_enabled && slaves_state_differ) {
1160                 /* A disabled slave was assigned an active mac addr */
1161                 rlb_teach_disabled_mac_on_primary(bond,
1162                                                   disabled_slave->dev->dev_addr);
1163         }
1164 }
1165
1166 /**
1167  * alb_change_hw_addr_on_detach
1168  * @bond: bonding we're working on
1169  * @slave: the slave that was just detached
1170  *
1171  * We assume that @slave was already detached from the slave list.
1172  *
1173  * If @slave's permanent hw address is different both from its current
1174  * address and from @bond's address, then somewhere in the bond there's
1175  * a slave that has @slave's permanet address as its current address.
1176  * We'll make sure that that slave no longer uses @slave's permanent address.
1177  *
1178  * Caller must hold RTNL and no other locks
1179  */
1180 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
1181 {
1182         int perm_curr_diff;
1183         int perm_bond_diff;
1184         struct slave *found_slave;
1185
1186         perm_curr_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
1187                                                   slave->dev->dev_addr);
1188         perm_bond_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
1189                                                   bond->dev->dev_addr);
1190
1191         if (perm_curr_diff && perm_bond_diff) {
1192                 found_slave = bond_slave_has_mac(bond, slave->perm_hwaddr);
1193
1194                 if (found_slave) {
1195                         /* locking: needs RTNL and nothing else */
1196                         alb_swap_mac_addr(slave, found_slave);
1197                         alb_fasten_mac_swap(bond, slave, found_slave);
1198                 }
1199         }
1200 }
1201
1202 /**
1203  * alb_handle_addr_collision_on_attach
1204  * @bond: bonding we're working on
1205  * @slave: the slave that was just attached
1206  *
1207  * checks uniqueness of slave's mac address and handles the case the
1208  * new slave uses the bonds mac address.
1209  *
1210  * If the permanent hw address of @slave is @bond's hw address, we need to
1211  * find a different hw address to give @slave, that isn't in use by any other
1212  * slave in the bond. This address must be, of course, one of the permanent
1213  * addresses of the other slaves.
1214  *
1215  * We go over the slave list, and for each slave there we compare its
1216  * permanent hw address with the current address of all the other slaves.
1217  * If no match was found, then we've found a slave with a permanent address
1218  * that isn't used by any other slave in the bond, so we can assign it to
1219  * @slave.
1220  *
1221  * assumption: this function is called before @slave is attached to the
1222  *             bond slave list.
1223  */
1224 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
1225 {
1226         struct slave *has_bond_addr = rcu_access_pointer(bond->curr_active_slave);
1227         struct slave *tmp_slave1, *free_mac_slave = NULL;
1228         struct list_head *iter;
1229
1230         if (!bond_has_slaves(bond)) {
1231                 /* this is the first slave */
1232                 return 0;
1233         }
1234
1235         /* if slave's mac address differs from bond's mac address
1236          * check uniqueness of slave's mac address against the other
1237          * slaves in the bond.
1238          */
1239         if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {
1240                 if (!bond_slave_has_mac(bond, slave->dev->dev_addr))
1241                         return 0;
1242
1243                 /* Try setting slave mac to bond address and fall-through
1244                    to code handling that situation below... */
1245                 alb_set_slave_mac_addr(slave, bond->dev->dev_addr);
1246         }
1247
1248         /* The slave's address is equal to the address of the bond.
1249          * Search for a spare address in the bond for this slave.
1250          */
1251         bond_for_each_slave(bond, tmp_slave1, iter) {
1252                 if (!bond_slave_has_mac(bond, tmp_slave1->perm_hwaddr)) {
1253                         /* no slave has tmp_slave1's perm addr
1254                          * as its curr addr
1255                          */
1256                         free_mac_slave = tmp_slave1;
1257                         break;
1258                 }
1259
1260                 if (!has_bond_addr) {
1261                         if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,
1262                                                     bond->dev->dev_addr)) {
1263
1264                                 has_bond_addr = tmp_slave1;
1265                         }
1266                 }
1267         }
1268
1269         if (free_mac_slave) {
1270                 alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr);
1271
1272                 netdev_warn(bond->dev, "the hw address of slave %s is in use by the bond; giving it the hw address of %s\n",
1273                             slave->dev->name, free_mac_slave->dev->name);
1274
1275         } else if (has_bond_addr) {
1276                 netdev_err(bond->dev, "the hw address of slave %s is in use by the bond; couldn't find a slave with a free hw address to give it (this should not have happened)\n",
1277                            slave->dev->name);
1278                 return -EFAULT;
1279         }
1280
1281         return 0;
1282 }
1283
1284 /**
1285  * alb_set_mac_address
1286  * @bond:
1287  * @addr:
1288  *
1289  * In TLB mode all slaves are configured to the bond's hw address, but set
1290  * their dev_addr field to different addresses (based on their permanent hw
1291  * addresses).
1292  *
1293  * For each slave, this function sets the interface to the new address and then
1294  * changes its dev_addr field to its previous value.
1295  *
1296  * Unwinding assumes bond's mac address has not yet changed.
1297  */
1298 static int alb_set_mac_address(struct bonding *bond, void *addr)
1299 {
1300         struct slave *slave, *rollback_slave;
1301         struct list_head *iter;
1302         struct sockaddr sa;
1303         char tmp_addr[ETH_ALEN];
1304         int res;
1305
1306         if (bond->alb_info.rlb_enabled)
1307                 return 0;
1308
1309         bond_for_each_slave(bond, slave, iter) {
1310                 /* save net_device's current hw address */
1311                 ether_addr_copy(tmp_addr, slave->dev->dev_addr);
1312
1313                 res = dev_set_mac_address(slave->dev, addr);
1314
1315                 /* restore net_device's hw address */
1316                 ether_addr_copy(slave->dev->dev_addr, tmp_addr);
1317
1318                 if (res)
1319                         goto unwind;
1320         }
1321
1322         return 0;
1323
1324 unwind:
1325         memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1326         sa.sa_family = bond->dev->type;
1327
1328         /* unwind from head to the slave that failed */
1329         bond_for_each_slave(bond, rollback_slave, iter) {
1330                 if (rollback_slave == slave)
1331                         break;
1332                 ether_addr_copy(tmp_addr, rollback_slave->dev->dev_addr);
1333                 dev_set_mac_address(rollback_slave->dev, &sa);
1334                 ether_addr_copy(rollback_slave->dev->dev_addr, tmp_addr);
1335         }
1336
1337         return res;
1338 }
1339
1340 /************************ exported alb funcions ************************/
1341
1342 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1343 {
1344         int res;
1345
1346         res = tlb_initialize(bond);
1347         if (res)
1348                 return res;
1349
1350         if (rlb_enabled) {
1351                 bond->alb_info.rlb_enabled = 1;
1352                 /* initialize rlb */
1353                 res = rlb_initialize(bond);
1354                 if (res) {
1355                         tlb_deinitialize(bond);
1356                         return res;
1357                 }
1358         } else {
1359                 bond->alb_info.rlb_enabled = 0;
1360         }
1361
1362         return 0;
1363 }
1364
1365 void bond_alb_deinitialize(struct bonding *bond)
1366 {
1367         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1368
1369         tlb_deinitialize(bond);
1370
1371         if (bond_info->rlb_enabled)
1372                 rlb_deinitialize(bond);
1373 }
1374
1375 static int bond_do_alb_xmit(struct sk_buff *skb, struct bonding *bond,
1376                 struct slave *tx_slave)
1377 {
1378         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1379         struct ethhdr *eth_data = eth_hdr(skb);
1380
1381         if (!tx_slave) {
1382                 /* unbalanced or unassigned, send through primary */
1383                 tx_slave = rcu_dereference(bond->curr_active_slave);
1384                 if (bond->params.tlb_dynamic_lb)
1385                         bond_info->unbalanced_load += skb->len;
1386         }
1387
1388         if (tx_slave && bond_slave_can_tx(tx_slave)) {
1389                 if (tx_slave != rcu_dereference(bond->curr_active_slave)) {
1390                         ether_addr_copy(eth_data->h_source,
1391                                         tx_slave->dev->dev_addr);
1392                 }
1393
1394                 bond_dev_queue_xmit(bond, skb, tx_slave->dev);
1395                 goto out;
1396         }
1397
1398         if (tx_slave && bond->params.tlb_dynamic_lb) {
1399                 _lock_tx_hashtbl(bond);
1400                 __tlb_clear_slave(bond, tx_slave, 0);
1401                 _unlock_tx_hashtbl(bond);
1402         }
1403
1404         /* no suitable interface, frame not sent */
1405         dev_kfree_skb_any(skb);
1406 out:
1407         return NETDEV_TX_OK;
1408 }
1409
1410 static int bond_tlb_update_slave_arr(struct bonding *bond,
1411                                      struct slave *skipslave)
1412 {
1413         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1414         struct slave *tx_slave;
1415         struct list_head *iter;
1416         struct tlb_up_slave *new_arr, *old_arr;
1417
1418         new_arr = kzalloc(offsetof(struct tlb_up_slave, arr[bond->slave_cnt]),
1419                           GFP_ATOMIC);
1420         if (!new_arr)
1421                 return -ENOMEM;
1422
1423         bond_for_each_slave(bond, tx_slave, iter) {
1424                 if (!bond_slave_can_tx(tx_slave))
1425                         continue;
1426                 if (skipslave == tx_slave)
1427                         continue;
1428                 new_arr->arr[new_arr->count++] = tx_slave;
1429         }
1430
1431         old_arr = rtnl_dereference(bond_info->slave_arr);
1432         rcu_assign_pointer(bond_info->slave_arr, new_arr);
1433         if (old_arr)
1434                 kfree_rcu(old_arr, rcu);
1435
1436         return 0;
1437 }
1438
1439 int bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1440 {
1441         struct bonding *bond = netdev_priv(bond_dev);
1442         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1443         struct ethhdr *eth_data;
1444         struct slave *tx_slave = NULL;
1445         u32 hash_index;
1446
1447         skb_reset_mac_header(skb);
1448         eth_data = eth_hdr(skb);
1449
1450         /* Do not TX balance any multicast or broadcast */
1451         if (!is_multicast_ether_addr(eth_data->h_dest)) {
1452                 switch (skb->protocol) {
1453                 case htons(ETH_P_IP):
1454                 case htons(ETH_P_IPX):
1455                     /* In case of IPX, it will falback to L2 hash */
1456                 case htons(ETH_P_IPV6):
1457                         hash_index = bond_xmit_hash(bond, skb);
1458                         if (bond->params.tlb_dynamic_lb) {
1459                                 tx_slave = tlb_choose_channel(bond,
1460                                                               hash_index & 0xFF,
1461                                                               skb->len);
1462                         } else {
1463                                 struct tlb_up_slave *slaves;
1464
1465                                 slaves = rcu_dereference(bond_info->slave_arr);
1466                                 if (slaves && slaves->count)
1467                                         tx_slave = slaves->arr[hash_index %
1468                                                                slaves->count];
1469                         }
1470                         break;
1471                 }
1472         }
1473         return bond_do_alb_xmit(skb, bond, tx_slave);
1474 }
1475
1476 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1477 {
1478         struct bonding *bond = netdev_priv(bond_dev);
1479         struct ethhdr *eth_data;
1480         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1481         struct slave *tx_slave = NULL;
1482         static const __be32 ip_bcast = htonl(0xffffffff);
1483         int hash_size = 0;
1484         bool do_tx_balance = true;
1485         u32 hash_index = 0;
1486         const u8 *hash_start = NULL;
1487         struct ipv6hdr *ip6hdr;
1488
1489         skb_reset_mac_header(skb);
1490         eth_data = eth_hdr(skb);
1491
1492         switch (ntohs(skb->protocol)) {
1493         case ETH_P_IP: {
1494                 const struct iphdr *iph = ip_hdr(skb);
1495
1496                 if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast) ||
1497                     (iph->daddr == ip_bcast) ||
1498                     (iph->protocol == IPPROTO_IGMP)) {
1499                         do_tx_balance = false;
1500                         break;
1501                 }
1502                 hash_start = (char *)&(iph->daddr);
1503                 hash_size = sizeof(iph->daddr);
1504         }
1505                 break;
1506         case ETH_P_IPV6:
1507                 /* IPv6 doesn't really use broadcast mac address, but leave
1508                  * that here just in case.
1509                  */
1510                 if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast)) {
1511                         do_tx_balance = false;
1512                         break;
1513                 }
1514
1515                 /* IPv6 uses all-nodes multicast as an equivalent to
1516                  * broadcasts in IPv4.
1517                  */
1518                 if (ether_addr_equal_64bits(eth_data->h_dest, mac_v6_allmcast)) {
1519                         do_tx_balance = false;
1520                         break;
1521                 }
1522
1523                 /* Additianally, DAD probes should not be tx-balanced as that
1524                  * will lead to false positives for duplicate addresses and
1525                  * prevent address configuration from working.
1526                  */
1527                 ip6hdr = ipv6_hdr(skb);
1528                 if (ipv6_addr_any(&ip6hdr->saddr)) {
1529                         do_tx_balance = false;
1530                         break;
1531                 }
1532
1533                 hash_start = (char *)&(ipv6_hdr(skb)->daddr);
1534                 hash_size = sizeof(ipv6_hdr(skb)->daddr);
1535                 break;
1536         case ETH_P_IPX:
1537                 if (ipx_hdr(skb)->ipx_checksum != IPX_NO_CHECKSUM) {
1538                         /* something is wrong with this packet */
1539                         do_tx_balance = false;
1540                         break;
1541                 }
1542
1543                 if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
1544                         /* The only protocol worth balancing in
1545                          * this family since it has an "ARP" like
1546                          * mechanism
1547                          */
1548                         do_tx_balance = false;
1549                         break;
1550                 }
1551
1552                 hash_start = (char *)eth_data->h_dest;
1553                 hash_size = ETH_ALEN;
1554                 break;
1555         case ETH_P_ARP:
1556                 do_tx_balance = false;
1557                 if (bond_info->rlb_enabled)
1558                         tx_slave = rlb_arp_xmit(skb, bond);
1559                 break;
1560         default:
1561                 do_tx_balance = false;
1562                 break;
1563         }
1564
1565         if (do_tx_balance) {
1566                 hash_index = _simple_hash(hash_start, hash_size);
1567                 tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1568         }
1569
1570         return bond_do_alb_xmit(skb, bond, tx_slave);
1571 }
1572
1573 void bond_alb_monitor(struct work_struct *work)
1574 {
1575         struct bonding *bond = container_of(work, struct bonding,
1576                                             alb_work.work);
1577         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1578         struct list_head *iter;
1579         struct slave *slave;
1580
1581         if (!bond_has_slaves(bond)) {
1582                 bond_info->tx_rebalance_counter = 0;
1583                 bond_info->lp_counter = 0;
1584                 goto re_arm;
1585         }
1586
1587         rcu_read_lock();
1588
1589         bond_info->tx_rebalance_counter++;
1590         bond_info->lp_counter++;
1591
1592         /* send learning packets */
1593         if (bond_info->lp_counter >= BOND_ALB_LP_TICKS(bond)) {
1594                 bool strict_match;
1595
1596                 /* change of curr_active_slave involves swapping of mac addresses.
1597                  * in order to avoid this swapping from happening while
1598                  * sending the learning packets, the curr_slave_lock must be held for
1599                  * read.
1600                  */
1601                 read_lock(&bond->curr_slave_lock);
1602
1603                 bond_for_each_slave_rcu(bond, slave, iter) {
1604                         /* If updating current_active, use all currently
1605                          * user mac addreses (!strict_match).  Otherwise, only
1606                          * use mac of the slave device.
1607                          * In RLB mode, we always use strict matches.
1608                          */
1609                         strict_match = (slave != rcu_access_pointer(bond->curr_active_slave) ||
1610                                         bond_info->rlb_enabled);
1611                         alb_send_learning_packets(slave, slave->dev->dev_addr,
1612                                                   strict_match);
1613                 }
1614
1615                 read_unlock(&bond->curr_slave_lock);
1616
1617                 bond_info->lp_counter = 0;
1618         }
1619
1620         /* rebalance tx traffic */
1621         if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1622
1623                 read_lock(&bond->curr_slave_lock);
1624
1625                 bond_for_each_slave_rcu(bond, slave, iter) {
1626                         tlb_clear_slave(bond, slave, 1);
1627                         if (slave == rcu_access_pointer(bond->curr_active_slave)) {
1628                                 SLAVE_TLB_INFO(slave).load =
1629                                         bond_info->unbalanced_load /
1630                                                 BOND_TLB_REBALANCE_INTERVAL;
1631                                 bond_info->unbalanced_load = 0;
1632                         }
1633                 }
1634
1635                 read_unlock(&bond->curr_slave_lock);
1636
1637                 bond_info->tx_rebalance_counter = 0;
1638         }
1639
1640         /* handle rlb stuff */
1641         if (bond_info->rlb_enabled) {
1642                 if (bond_info->primary_is_promisc &&
1643                     (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1644
1645                         /*
1646                          * dev_set_promiscuity requires rtnl and
1647                          * nothing else.  Avoid race with bond_close.
1648                          */
1649                         rcu_read_unlock();
1650                         if (!rtnl_trylock())
1651                                 goto re_arm;
1652
1653                         bond_info->rlb_promisc_timeout_counter = 0;
1654
1655                         /* If the primary was set to promiscuous mode
1656                          * because a slave was disabled then
1657                          * it can now leave promiscuous mode.
1658                          */
1659                         dev_set_promiscuity(rtnl_dereference(bond->curr_active_slave)->dev,
1660                                             -1);
1661                         bond_info->primary_is_promisc = 0;
1662
1663                         rtnl_unlock();
1664                         rcu_read_lock();
1665                 }
1666
1667                 if (bond_info->rlb_rebalance) {
1668                         bond_info->rlb_rebalance = 0;
1669                         rlb_rebalance(bond);
1670                 }
1671
1672                 /* check if clients need updating */
1673                 if (bond_info->rx_ntt) {
1674                         if (bond_info->rlb_update_delay_counter) {
1675                                 --bond_info->rlb_update_delay_counter;
1676                         } else {
1677                                 rlb_update_rx_clients(bond);
1678                                 if (bond_info->rlb_update_retry_counter)
1679                                         --bond_info->rlb_update_retry_counter;
1680                                 else
1681                                         bond_info->rx_ntt = 0;
1682                         }
1683                 }
1684         }
1685         rcu_read_unlock();
1686 re_arm:
1687         queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);
1688 }
1689
1690 /* assumption: called before the slave is attached to the bond
1691  * and not locked by the bond lock
1692  */
1693 int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
1694 {
1695         int res;
1696
1697         res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr);
1698         if (res)
1699                 return res;
1700
1701         res = alb_handle_addr_collision_on_attach(bond, slave);
1702         if (res)
1703                 return res;
1704
1705         tlb_init_slave(slave);
1706
1707         /* order a rebalance ASAP */
1708         bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1709
1710         if (bond->alb_info.rlb_enabled)
1711                 bond->alb_info.rlb_rebalance = 1;
1712
1713         return 0;
1714 }
1715
1716 /*
1717  * Remove slave from tlb and rlb hash tables, and fix up MAC addresses
1718  * if necessary.
1719  *
1720  * Caller must hold RTNL and no other locks
1721  */
1722 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1723 {
1724         if (bond_has_slaves(bond))
1725                 alb_change_hw_addr_on_detach(bond, slave);
1726
1727         tlb_clear_slave(bond, slave, 0);
1728
1729         if (bond->alb_info.rlb_enabled) {
1730                 bond->alb_info.rx_slave = NULL;
1731                 rlb_clear_slave(bond, slave);
1732         }
1733
1734         if (bond_is_nondyn_tlb(bond))
1735                 if (bond_tlb_update_slave_arr(bond, slave))
1736                         pr_err("Failed to build slave-array for TLB mode.\n");
1737
1738 }
1739
1740 /* Caller must hold bond lock for read */
1741 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1742 {
1743         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1744
1745         if (link == BOND_LINK_DOWN) {
1746                 tlb_clear_slave(bond, slave, 0);
1747                 if (bond->alb_info.rlb_enabled)
1748                         rlb_clear_slave(bond, slave);
1749         } else if (link == BOND_LINK_UP) {
1750                 /* order a rebalance ASAP */
1751                 bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1752                 if (bond->alb_info.rlb_enabled) {
1753                         bond->alb_info.rlb_rebalance = 1;
1754                         /* If the updelay module parameter is smaller than the
1755                          * forwarding delay of the switch the rebalance will
1756                          * not work because the rebalance arp replies will
1757                          * not be forwarded to the clients..
1758                          */
1759                 }
1760         }
1761
1762         if (bond_is_nondyn_tlb(bond)) {
1763                 if (bond_tlb_update_slave_arr(bond, NULL))
1764                         pr_err("Failed to build slave-array for TLB mode.\n");
1765         }
1766 }
1767
1768 /**
1769  * bond_alb_handle_active_change - assign new curr_active_slave
1770  * @bond: our bonding struct
1771  * @new_slave: new slave to assign
1772  *
1773  * Set the bond->curr_active_slave to @new_slave and handle
1774  * mac address swapping and promiscuity changes as needed.
1775  *
1776  * If new_slave is NULL, caller must hold curr_slave_lock or
1777  * bond->lock for write.
1778  *
1779  * If new_slave is not NULL, caller must hold RTNL, curr_slave_lock
1780  * for write.  Processing here may sleep, so no other locks may be held.
1781  */
1782 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1783         __releases(&bond->curr_slave_lock)
1784         __acquires(&bond->curr_slave_lock)
1785 {
1786         struct slave *swap_slave;
1787         struct slave *curr_active;
1788
1789         curr_active = rcu_dereference_protected(bond->curr_active_slave,
1790                                                 !new_slave ||
1791                                                 lockdep_is_held(&bond->curr_slave_lock));
1792         if (curr_active == new_slave)
1793                 return;
1794
1795         if (curr_active && bond->alb_info.primary_is_promisc) {
1796                 dev_set_promiscuity(curr_active->dev, -1);
1797                 bond->alb_info.primary_is_promisc = 0;
1798                 bond->alb_info.rlb_promisc_timeout_counter = 0;
1799         }
1800
1801         swap_slave = curr_active;
1802         rcu_assign_pointer(bond->curr_active_slave, new_slave);
1803
1804         if (!new_slave || !bond_has_slaves(bond))
1805                 return;
1806
1807         /* set the new curr_active_slave to the bonds mac address
1808          * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1809          */
1810         if (!swap_slave)
1811                 swap_slave = bond_slave_has_mac(bond, bond->dev->dev_addr);
1812
1813         /*
1814          * Arrange for swap_slave and new_slave to temporarily be
1815          * ignored so we can mess with their MAC addresses without
1816          * fear of interference from transmit activity.
1817          */
1818         if (swap_slave)
1819                 tlb_clear_slave(bond, swap_slave, 1);
1820         tlb_clear_slave(bond, new_slave, 1);
1821
1822         write_unlock_bh(&bond->curr_slave_lock);
1823
1824         ASSERT_RTNL();
1825
1826         /* in TLB mode, the slave might flip down/up with the old dev_addr,
1827          * and thus filter bond->dev_addr's packets, so force bond's mac
1828          */
1829         if (BOND_MODE(bond) == BOND_MODE_TLB) {
1830                 struct sockaddr sa;
1831                 u8 tmp_addr[ETH_ALEN];
1832
1833                 ether_addr_copy(tmp_addr, new_slave->dev->dev_addr);
1834
1835                 memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1836                 sa.sa_family = bond->dev->type;
1837                 /* we don't care if it can't change its mac, best effort */
1838                 dev_set_mac_address(new_slave->dev, &sa);
1839
1840                 ether_addr_copy(new_slave->dev->dev_addr, tmp_addr);
1841         }
1842
1843         /* curr_active_slave must be set before calling alb_swap_mac_addr */
1844         if (swap_slave) {
1845                 /* swap mac address */
1846                 alb_swap_mac_addr(swap_slave, new_slave);
1847                 alb_fasten_mac_swap(bond, swap_slave, new_slave);
1848         } else {
1849                 /* set the new_slave to the bond mac address */
1850                 alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr);
1851                 alb_send_learning_packets(new_slave, bond->dev->dev_addr,
1852                                           false);
1853         }
1854
1855         write_lock_bh(&bond->curr_slave_lock);
1856 }
1857
1858 /*
1859  * Called with RTNL
1860  */
1861 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1862         __acquires(&bond->lock)
1863         __releases(&bond->lock)
1864 {
1865         struct bonding *bond = netdev_priv(bond_dev);
1866         struct sockaddr *sa = addr;
1867         struct slave *curr_active;
1868         struct slave *swap_slave;
1869         int res;
1870
1871         if (!is_valid_ether_addr(sa->sa_data))
1872                 return -EADDRNOTAVAIL;
1873
1874         res = alb_set_mac_address(bond, addr);
1875         if (res)
1876                 return res;
1877
1878         memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1879
1880         /* If there is no curr_active_slave there is nothing else to do.
1881          * Otherwise we'll need to pass the new address to it and handle
1882          * duplications.
1883          */
1884         curr_active = rtnl_dereference(bond->curr_active_slave);
1885         if (!curr_active)
1886                 return 0;
1887
1888         swap_slave = bond_slave_has_mac(bond, bond_dev->dev_addr);
1889
1890         if (swap_slave) {
1891                 alb_swap_mac_addr(swap_slave, curr_active);
1892                 alb_fasten_mac_swap(bond, swap_slave, curr_active);
1893         } else {
1894                 alb_set_slave_mac_addr(curr_active, bond_dev->dev_addr);
1895
1896                 read_lock(&bond->lock);
1897                 alb_send_learning_packets(curr_active,
1898                                           bond_dev->dev_addr, false);
1899                 if (bond->alb_info.rlb_enabled) {
1900                         /* inform clients mac address has changed */
1901                         rlb_req_update_slave_clients(bond, curr_active);
1902                 }
1903                 read_unlock(&bond->lock);
1904         }
1905
1906         return 0;
1907 }
1908
1909 void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
1910 {
1911         if (bond->alb_info.rlb_enabled)
1912                 rlb_clear_vlan(bond, vlan_id);
1913 }
1914