drivers/net/bonding/bond_alb.c

   1 /*
   2  * Copyright(c) 1999 - 2003 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, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  *
  22  * Changes:
  23  *
  24  * 2003/06/25 - Shmulik Hen <shmulik.hen at intel dot com>
  25  *      - Fixed signed/unsigned calculation errors that caused load sharing
  26  *        to collapse to one slave under very heavy UDP Tx stress.
  27  *
  28  * 2003/08/06 - Amir Noam <amir.noam at intel dot com>
  29  *      - Add support for setting bond's MAC address with special
  30  *        handling required for ALB/TLB.
  31  */
  32
  33 //#define BONDING_DEBUG 1
  34
  35 #include <linux/skbuff.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/etherdevice.h>
  38 #include <linux/pkt_sched.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <linux/timer.h>
  42 #include <linux/ip.h>
  43 #include <linux/ipv6.h>
  44 #include <linux/if_arp.h>
  45 #include <linux/if_ether.h>
  46 #include <linux/if_bonding.h>
  47 #include <net/ipx.h>
  48 #include <net/arp.h>
  49 #include <asm/byteorder.h>
  50 #include "bonding.h"
  51 #include "bond_alb.h"
  52
  53
  54 #define ALB_TIMER_TICKS_PER_SEC     10  /* should be a divisor of HZ */
  55 #define BOND_TLB_REBALANCE_INTERVAL 10  /* in seconds, periodic re-balancing
  56                                          * used for division - never set
  57                                          * to zero !!!
  58                                          */
  59 #define BOND_ALB_LP_INTERVAL        1   /* in seconds periodic send of
  60                                          * learning packets to the switch
  61                                          */
  62
  63 #define BOND_TLB_REBALANCE_TICKS (BOND_TLB_REBALANCE_INTERVAL \
  64                                   * ALB_TIMER_TICKS_PER_SEC)
  65
  66 #define BOND_ALB_LP_TICKS (BOND_ALB_LP_INTERVAL \
  67                            * ALB_TIMER_TICKS_PER_SEC)
  68
  69 #define TLB_HASH_TABLE_SIZE 256 /* The size of the clients hash table.
  70                                  * Note that this value MUST NOT be smaller
  71                                  * because the key hash table BYTE wide !
  72                                  */
  73
  74
  75 #define TLB_NULL_INDEX          0xffffffff
  76 #define MAX_LP_RETRY            3
  77
  78 /* rlb defs */
  79 #define RLB_HASH_TABLE_SIZE     256
  80 #define RLB_NULL_INDEX          0xffffffff
  81 #define RLB_UPDATE_DELAY        2*ALB_TIMER_TICKS_PER_SEC /* 2 seconds */
  82 #define RLB_ARP_BURST_SIZE      2
  83 #define RLB_UPDATE_RETRY        3       /* 3-ticks - must be smaller than the rlb
  84                                          * rebalance interval (5 min).
  85                                          */
  86 /* RLB_PROMISC_TIMEOUT = 10 sec equals the time that the current slave is
  87  * promiscuous after failover
  88  */
  89 #define RLB_PROMISC_TIMEOUT     10*ALB_TIMER_TICKS_PER_SEC
  90
  91 static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
  92
  93 #pragma pack(1)
  94 struct learning_pkt {
  95         u8 mac_dst[ETH_ALEN];
  96         u8 mac_src[ETH_ALEN];
  97         u16 type;
  98         u8 padding[ETH_ZLEN - ETH_HLEN];
  99 };
 100
 101 struct arp_pkt {
 102         u16     hw_addr_space;
 103         u16     prot_addr_space;
 104         u8      hw_addr_len;
 105         u8      prot_addr_len;
 106         u16     op_code;
 107         u8      mac_src[ETH_ALEN];      /* sender hardware address */
 108         u32     ip_src;                 /* sender IP address */
 109         u8      mac_dst[ETH_ALEN];      /* target hardware address */
 110         u32     ip_dst;                 /* target IP address */
 111 };
 112 #pragma pack()
 113
 114 /* Forward declaration */
 115 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);
 116
 117 static inline u8 _simple_hash(u8 *hash_start, int hash_size)
 118 {
 119         int i;
 120         u8 hash = 0;
 121
 122         for (i = 0; i < hash_size; i++) {
 123                 hash ^= hash_start[i];
 124         }
 125
 126         return hash;
 127 }
 128
 129 /*********************** tlb specific functions ***************************/
 130
 131 static inline void _lock_tx_hashtbl(struct bonding *bond)
 132 {
 133         spin_lock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 134 }
 135
 136 static inline void _unlock_tx_hashtbl(struct bonding *bond)
 137 {
 138         spin_unlock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
 139 }
 140
 141 /* Caller must hold tx_hashtbl lock */
 142 static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
 143 {
 144         if (save_load) {
 145                 entry->load_history = 1 + entry->tx_bytes /
 146                         BOND_TLB_REBALANCE_INTERVAL;
 147                 entry->tx_bytes = 0;
 148         }
 149         entry->tx_slave = NULL;
 150         entry->next = TLB_NULL_INDEX;
 151         entry->prev = TLB_NULL_INDEX;
 152 }
 153
 154 static inline void tlb_init_slave(struct slave *slave)
 155 {
 156         SLAVE_TLB_INFO(slave).load = 0;
 157         SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
 158 }
 159
 160 /* Caller must hold bond lock for read */
 161 static void tlb_clear_slave(struct bonding *bond, struct slave *slave, int save_load)
 162 {
 163         struct tlb_client_info *tx_hash_table;
 164         u32 index;
 165
 166         _lock_tx_hashtbl(bond);
 167         /* clear slave from tx_hashtbl */
 168         tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;
 169
 170         index = SLAVE_TLB_INFO(slave).head;
 171         while (index != TLB_NULL_INDEX) {
 172                 u32 next_index = tx_hash_table[index].next;
 173                 tlb_init_table_entry(&tx_hash_table[index], save_load);
 174                 index = next_index;
 175         }
 176         _unlock_tx_hashtbl(bond);
 177
 178         tlb_init_slave(slave);
 179 }
 180
 181 /* Must be called before starting the monitor timer */
 182 static int tlb_initialize(struct bonding *bond)
 183 {
 184         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 185         int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
 186         int i;
 187
 188         spin_lock_init(&(bond_info->tx_hashtbl_lock));
 189
 190         _lock_tx_hashtbl(bond);
 191
 192         bond_info->tx_hashtbl = kmalloc(size, GFP_KERNEL);
 193         if (!bond_info->tx_hashtbl) {
 194                 printk(KERN_ERR DRV_NAME
 195                        ": Error: %s: Failed to allocate TLB hash table\n",
 196                        bond->dev->name);
 197                 _unlock_tx_hashtbl(bond);
 198                 return -1;
 199         }
 200
 201         memset(bond_info->tx_hashtbl, 0, size);
 202         for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
 203                 tlb_init_table_entry(&bond_info->tx_hashtbl[i], 1);
 204         }
 205         _unlock_tx_hashtbl(bond);
 206
 207         return 0;
 208 }
 209
 210 /* Must be called only after all slaves have been released */
 211 static void tlb_deinitialize(struct bonding *bond)
 212 {
 213         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 214
 215         _lock_tx_hashtbl(bond);
 216         kfree(bond_info->tx_hashtbl);
 217         bond_info->tx_hashtbl = NULL;
 218         _unlock_tx_hashtbl(bond);
 219 }
 220
 221 /* Caller must hold bond lock for read */
 222 static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
 223 {
 224         struct slave *slave, *least_loaded;
 225         s64 max_gap;
 226         int i, found = 0;
 227
 228         /* Find the first enabled slave */
 229         bond_for_each_slave(bond, slave, i) {
 230                 if (SLAVE_IS_OK(slave)) {
 231                         found = 1;
 232                         break;
 233                 }
 234         }
 235
 236         if (!found) {
 237                 return NULL;
 238         }
 239
 240         least_loaded = slave;
 241         max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
 242                         (s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
 243
 244         /* Find the slave with the largest gap */
 245         bond_for_each_slave_from(bond, slave, i, least_loaded) {
 246                 if (SLAVE_IS_OK(slave)) {
 247                         s64 gap = (s64)(slave->speed << 20) -
 248                                         (s64)(SLAVE_TLB_INFO(slave).load << 3);
 249                         if (max_gap < gap) {
 250                                 least_loaded = slave;
 251                                 max_gap = gap;
 252                         }
 253                 }
 254         }
 255
 256         return least_loaded;
 257 }
 258
 259 /* Caller must hold bond lock for read */
 260 struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index, u32 skb_len)
 261 {
 262         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 263         struct tlb_client_info *hash_table;
 264         struct slave *assigned_slave;
 265
 266         _lock_tx_hashtbl(bond);
 267
 268         hash_table = bond_info->tx_hashtbl;
 269         assigned_slave = hash_table[hash_index].tx_slave;
 270         if (!assigned_slave) {
 271                 assigned_slave = tlb_get_least_loaded_slave(bond);
 272
 273                 if (assigned_slave) {
 274                         struct tlb_slave_info *slave_info =
 275                                 &(SLAVE_TLB_INFO(assigned_slave));
 276                         u32 next_index = slave_info->head;
 277
 278                         hash_table[hash_index].tx_slave = assigned_slave;
 279                         hash_table[hash_index].next = next_index;
 280                         hash_table[hash_index].prev = TLB_NULL_INDEX;
 281
 282                         if (next_index != TLB_NULL_INDEX) {
 283                                 hash_table[next_index].prev = hash_index;
 284                         }
 285
 286                         slave_info->head = hash_index;
 287                         slave_info->load +=
 288                                 hash_table[hash_index].load_history;
 289                 }
 290         }
 291
 292         if (assigned_slave) {
 293                 hash_table[hash_index].tx_bytes += skb_len;
 294         }
 295
 296         _unlock_tx_hashtbl(bond);
 297
 298         return assigned_slave;
 299 }
 300
 301 /*********************** rlb specific functions ***************************/
 302 static inline void _lock_rx_hashtbl(struct bonding *bond)
 303 {
 304         spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 305 }
 306
 307 static inline void _unlock_rx_hashtbl(struct bonding *bond)
 308 {
 309         spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
 310 }
 311
 312 /* when an ARP REPLY is received from a client update its info
 313  * in the rx_hashtbl
 314  */
 315 static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
 316 {
 317         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 318         struct rlb_client_info *client_info;
 319         u32 hash_index;
 320
 321         _lock_rx_hashtbl(bond);
 322
 323         hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
 324         client_info = &(bond_info->rx_hashtbl[hash_index]);
 325
 326         if ((client_info->assigned) &&
 327             (client_info->ip_src == arp->ip_dst) &&
 328             (client_info->ip_dst == arp->ip_src)) {
 329
 330                 /* update the clients MAC address */
 331                 memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
 332                 client_info->ntt = 1;
 333                 bond_info->rx_ntt = 1;
 334         }
 335
 336         _unlock_rx_hashtbl(bond);
 337 }
 338
 339 static int rlb_arp_recv(struct sk_buff *skb, struct net_device *bond_dev, struct packet_type *ptype)
 340 {
 341         struct bonding *bond = (struct bonding *)bond_dev->priv;
 342         struct arp_pkt *arp = (struct arp_pkt *)skb->data;
 343         int res = NET_RX_DROP;
 344
 345         if (!(bond_dev->flags & IFF_MASTER)) {
 346                 goto out;
 347         }
 348
 349         if (!arp) {
 350                 dprintk("Packet has no ARP data\n");
 351                 goto out;
 352         }
 353
 354         if (skb->len < sizeof(struct arp_pkt)) {
 355                 dprintk("Packet is too small to be an ARP\n");
 356                 goto out;
 357         }
 358
 359         if (arp->op_code == htons(ARPOP_REPLY)) {
 360                 /* update rx hash table for this ARP */
 361                 rlb_update_entry_from_arp(bond, arp);
 362                 dprintk("Server received an ARP Reply from client\n");
 363         }
 364
 365         res = NET_RX_SUCCESS;
 366
 367 out:
 368         dev_kfree_skb(skb);
 369
 370         return res;
 371 }
 372
 373 /* Caller must hold bond lock for read */
 374 static struct slave *rlb_next_rx_slave(struct bonding *bond)
 375 {
 376         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 377         struct slave *rx_slave = NULL, *slave;
 378         int i = 0;
 379
 380         slave = bond_info->next_rx_slave;
 381         if (!slave) {
 382                 slave = bond->first_slave;
 383         }
 384
 385         bond_for_each_slave(bond, slave, i) {
 386                 if (SLAVE_IS_OK(slave)) {
 387                         if (!rx_slave) {
 388                                 rx_slave = slave;
 389                         } else if (slave->speed > rx_slave->speed) {
 390                                 rx_slave = slave;
 391                         }
 392                 }
 393         }
 394
 395         if (rx_slave) {
 396                 bond_info->next_rx_slave = rx_slave->next;
 397         }
 398
 399         return rx_slave;
 400 }
 401
 402 /* teach the switch the mac of a disabled slave
 403  * on the primary for fault tolerance
 404  *
 405  * Caller must hold bond->curr_slave_lock for write or bond lock for write
 406  */
 407 static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
 408 {
 409         if (!bond->curr_active_slave) {
 410                 return;
 411         }
 412         if (!bond->alb_info.primary_is_promisc) {
 413                 bond->alb_info.primary_is_promisc = 1;
 414                 dev_set_promiscuity(bond->curr_active_slave->dev, 1);
 415         }
 416         bond->alb_info.rlb_promisc_timeout_counter = 0;
 417
 418         alb_send_learning_packets(bond->curr_active_slave, addr);
 419 }
 420
 421 /* slave being removed should not be active at this point
 422  *
 423  * Caller must hold bond lock for read
 424  */
 425 static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
 426 {
 427         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 428         struct rlb_client_info *rx_hash_table;
 429         u32 index, next_index;
 430
 431         /* clear slave from rx_hashtbl */
 432         _lock_rx_hashtbl(bond);
 433
 434         rx_hash_table = bond_info->rx_hashtbl;
 435         index = bond_info->rx_hashtbl_head;
 436         for (; index != RLB_NULL_INDEX; index = next_index) {
 437                 next_index = rx_hash_table[index].next;
 438
 439                 if (rx_hash_table[index].slave == slave) {
 440                         struct slave *assigned_slave = rlb_next_rx_slave(bond);
 441
 442                         if (assigned_slave) {
 443                                 rx_hash_table[index].slave = assigned_slave;
 444                                 if (memcmp(rx_hash_table[index].mac_dst,
 445                                            mac_bcast, ETH_ALEN)) {
 446                                         bond_info->rx_hashtbl[index].ntt = 1;
 447                                         bond_info->rx_ntt = 1;
 448                                         /* A slave has been removed from the
 449                                          * table because it is either disabled
 450                                          * or being released. We must retry the
 451                                          * update to avoid clients from not
 452                                          * being updated & disconnecting when
 453                                          * there is stress
 454                                          */
 455                                         bond_info->rlb_update_retry_counter =
 456                                                 RLB_UPDATE_RETRY;
 457                                 }
 458                         } else {  /* there is no active slave */
 459                                 rx_hash_table[index].slave = NULL;
 460                         }
 461                 }
 462         }
 463
 464         _unlock_rx_hashtbl(bond);
 465
 466         write_lock(&bond->curr_slave_lock);
 467         if (slave != bond->curr_active_slave) {
 468                 rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
 469         }
 470         write_unlock(&bond->curr_slave_lock);
 471 }
 472
 473 static void rlb_update_client(struct rlb_client_info *client_info)
 474 {
 475         int i;
 476
 477         if (!client_info->slave) {
 478                 return;
 479         }
 480
 481         for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
 482                 arp_send(ARPOP_REPLY, ETH_P_ARP,
 483                          client_info->ip_dst,
 484                          client_info->slave->dev,
 485                          client_info->ip_src,
 486                          client_info->mac_dst,
 487                          client_info->slave->dev->dev_addr,
 488                          client_info->mac_dst);
 489         }
 490 }
 491
 492 /* sends ARP REPLIES that update the clients that need updating */
 493 static void rlb_update_rx_clients(struct bonding *bond)
 494 {
 495         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 496         struct rlb_client_info *client_info;
 497         u32 hash_index;
 498
 499         _lock_rx_hashtbl(bond);
 500
 501         hash_index = bond_info->rx_hashtbl_head;
 502         for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
 503                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 504                 if (client_info->ntt) {
 505                         rlb_update_client(client_info);
 506                         if (bond_info->rlb_update_retry_counter == 0) {
 507                                 client_info->ntt = 0;
 508                         }
 509                 }
 510         }
 511
 512         /* do not update the entries again untill this counter is zero so that
 513          * not to confuse the clients.
 514          */
 515         bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;
 516
 517         _unlock_rx_hashtbl(bond);
 518 }
 519
 520 /* The slave was assigned a new mac address - update the clients */
 521 static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
 522 {
 523         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 524         struct rlb_client_info *client_info;
 525         int ntt = 0;
 526         u32 hash_index;
 527
 528         _lock_rx_hashtbl(bond);
 529
 530         hash_index = bond_info->rx_hashtbl_head;
 531         for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
 532                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 533
 534                 if ((client_info->slave == slave) &&
 535                     memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
 536                         client_info->ntt = 1;
 537                         ntt = 1;
 538                 }
 539         }
 540
 541         // update the team's flag only after the whole iteration
 542         if (ntt) {
 543                 bond_info->rx_ntt = 1;
 544                 //fasten the change
 545                 bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
 546         }
 547
 548         _unlock_rx_hashtbl(bond);
 549 }
 550
 551 /* mark all clients using src_ip to be updated */
 552 static void rlb_req_update_subnet_clients(struct bonding *bond, u32 src_ip)
 553 {
 554         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 555         struct rlb_client_info *client_info;
 556         u32 hash_index;
 557
 558         _lock_rx_hashtbl(bond);
 559
 560         hash_index = bond_info->rx_hashtbl_head;
 561         for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
 562                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 563
 564                 if (!client_info->slave) {
 565                         printk(KERN_ERR DRV_NAME
 566                                ": Error: found a client with no channel in "
 567                                "the client's hash table\n");
 568                         continue;
 569                 }
 570                 /*update all clients using this src_ip, that are not assigned
 571                  * to the team's address (curr_active_slave) and have a known
 572                  * unicast mac address.
 573                  */
 574                 if ((client_info->ip_src == src_ip) &&
 575                     memcmp(client_info->slave->dev->dev_addr,
 576                            bond->dev->dev_addr, ETH_ALEN) &&
 577                     memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
 578                         client_info->ntt = 1;
 579                         bond_info->rx_ntt = 1;
 580                 }
 581         }
 582
 583         _unlock_rx_hashtbl(bond);
 584 }
 585
 586 /* Caller must hold both bond and ptr locks for read */
 587 struct slave *rlb_choose_channel(struct bonding *bond, struct arp_pkt *arp)
 588 {
 589         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 590         struct slave *assigned_slave;
 591         struct rlb_client_info *client_info;
 592         u32 hash_index = 0;
 593
 594         _lock_rx_hashtbl(bond);
 595
 596         hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_src));
 597         client_info = &(bond_info->rx_hashtbl[hash_index]);
 598
 599         if (client_info->assigned) {
 600                 if ((client_info->ip_src == arp->ip_src) &&
 601                     (client_info->ip_dst == arp->ip_dst)) {
 602                         /* the entry is already assigned to this client */
 603
 604                         if (memcmp(arp->mac_dst, mac_bcast, ETH_ALEN)) {
 605                                 /* update mac address from arp */
 606                                 memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
 607                         }
 608
 609                         assigned_slave = client_info->slave;
 610                         if (assigned_slave) {
 611                                 _unlock_rx_hashtbl(bond);
 612                                 return assigned_slave;
 613                         }
 614                 } else {
 615                         /* the entry is already assigned to some other client,
 616                          * move the old client to primary (curr_active_slave) so
 617                          * that the new client can be assigned to this entry.
 618                          */
 619                         if (bond->curr_active_slave &&
 620                             client_info->slave != bond->curr_active_slave) {
 621                                 client_info->slave = bond->curr_active_slave;
 622                                 rlb_update_client(client_info);
 623                         }
 624                 }
 625         }
 626         /* assign a new slave */
 627         assigned_slave = rlb_next_rx_slave(bond);
 628
 629         if (assigned_slave) {
 630                 client_info->ip_src = arp->ip_src;
 631                 client_info->ip_dst = arp->ip_dst;
 632                 /* arp->mac_dst is broadcast for arp reqeusts.
 633                  * will be updated with clients actual unicast mac address
 634                  * upon receiving an arp reply.
 635                  */
 636                 memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
 637                 client_info->slave = assigned_slave;
 638
 639                 if (memcmp(client_info->mac_dst, mac_bcast, ETH_ALEN)) {
 640                         client_info->ntt = 1;
 641                         bond->alb_info.rx_ntt = 1;
 642                 } else {
 643                         client_info->ntt = 0;
 644                 }
 645
 646                 if (!client_info->assigned) {
 647                         u32 prev_tbl_head = bond_info->rx_hashtbl_head;
 648                         bond_info->rx_hashtbl_head = hash_index;
 649                         client_info->next = prev_tbl_head;
 650                         if (prev_tbl_head != RLB_NULL_INDEX) {
 651                                 bond_info->rx_hashtbl[prev_tbl_head].prev =
 652                                         hash_index;
 653                         }
 654                         client_info->assigned = 1;
 655                 }
 656         }
 657
 658         _unlock_rx_hashtbl(bond);
 659
 660         return assigned_slave;
 661 }
 662
 663 /* chooses (and returns) transmit channel for arp reply
 664  * does not choose channel for other arp types since they are
 665  * sent on the curr_active_slave
 666  */
 667 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
 668 {
 669         struct arp_pkt *arp = (struct arp_pkt *)skb->nh.raw;
 670         struct slave *tx_slave = NULL;
 671
 672         if (arp->op_code == __constant_htons(ARPOP_REPLY)) {
 673                 /* the arp must be sent on the selected
 674                 * rx channel
 675                 */
 676                 tx_slave = rlb_choose_channel(bond, arp);
 677                 if (tx_slave) {
 678                         memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
 679                 }
 680                 dprintk("Server sent ARP Reply packet\n");
 681         } else if (arp->op_code == __constant_htons(ARPOP_REQUEST)) {
 682
 683                 /* Create an entry in the rx_hashtbl for this client as a
 684                  * place holder.
 685                  * When the arp reply is received the entry will be updated
 686                  * with the correct unicast address of the client.
 687                  */
 688                 rlb_choose_channel(bond, arp);
 689
 690                 /* The ARP relpy packets must be delayed so that
 691                  * they can cancel out the influence of the ARP request.
 692                  */
 693                 bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;
 694
 695                 /* arp requests are broadcast and are sent on the primary
 696                  * the arp request will collapse all clients on the subnet to
 697                  * the primary slave. We must register these clients to be
 698                  * updated with their assigned mac.
 699                  */
 700                 rlb_req_update_subnet_clients(bond, arp->ip_src);
 701                 dprintk("Server sent ARP Request packet\n");
 702         }
 703
 704         return tx_slave;
 705 }
 706
 707 /* Caller must hold bond lock for read */
 708 static void rlb_rebalance(struct bonding *bond)
 709 {
 710         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 711         struct slave *assigned_slave;
 712         struct rlb_client_info *client_info;
 713         int ntt;
 714         u32 hash_index;
 715
 716         _lock_rx_hashtbl(bond);
 717
 718         ntt = 0;
 719         hash_index = bond_info->rx_hashtbl_head;
 720         for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
 721                 client_info = &(bond_info->rx_hashtbl[hash_index]);
 722                 assigned_slave = rlb_next_rx_slave(bond);
 723                 if (assigned_slave && (client_info->slave != assigned_slave)) {
 724                         client_info->slave = assigned_slave;
 725                         client_info->ntt = 1;
 726                         ntt = 1;
 727                 }
 728         }
 729
 730         /* update the team's flag only after the whole iteration */
 731         if (ntt) {
 732                 bond_info->rx_ntt = 1;
 733         }
 734         _unlock_rx_hashtbl(bond);
 735 }
 736
 737 /* Caller must hold rx_hashtbl lock */
 738 static void rlb_init_table_entry(struct rlb_client_info *entry)
 739 {
 740         memset(entry, 0, sizeof(struct rlb_client_info));
 741         entry->next = RLB_NULL_INDEX;
 742         entry->prev = RLB_NULL_INDEX;
 743 }
 744
 745 static int rlb_initialize(struct bonding *bond)
 746 {
 747         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 748         struct packet_type *pk_type = &(BOND_ALB_INFO(bond).rlb_pkt_type);
 749         int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
 750         int i;
 751
 752         spin_lock_init(&(bond_info->rx_hashtbl_lock));
 753
 754         _lock_rx_hashtbl(bond);
 755
 756         bond_info->rx_hashtbl = kmalloc(size, GFP_KERNEL);
 757         if (!bond_info->rx_hashtbl) {
 758                 printk(KERN_ERR DRV_NAME
 759                        ": Error: %s: Failed to allocate RLB hash table\n",
 760                        bond->dev->name);
 761                 _unlock_rx_hashtbl(bond);
 762                 return -1;
 763         }
 764
 765         bond_info->rx_hashtbl_head = RLB_NULL_INDEX;
 766
 767         for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
 768                 rlb_init_table_entry(bond_info->rx_hashtbl + i);
 769         }
 770         _unlock_rx_hashtbl(bond);
 771
 772         /*initialize packet type*/
 773         pk_type->type = __constant_htons(ETH_P_ARP);
 774         pk_type->dev = bond->dev;
 775         pk_type->func = rlb_arp_recv;
 776
 777         /* register to receive ARPs */
 778         dev_add_pack(pk_type);
 779
 780         return 0;
 781 }
 782
 783 static void rlb_deinitialize(struct bonding *bond)
 784 {
 785         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
 786
 787         dev_remove_pack(&(bond_info->rlb_pkt_type));
 788
 789         _lock_rx_hashtbl(bond);
 790         kfree(bond_info->rx_hashtbl);
 791         bond_info->rx_hashtbl = NULL;
 792         _unlock_rx_hashtbl(bond);
 793 }
 794
 795 /*********************** tlb/rlb shared functions *********************/
 796
 797 static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
 798 {
 799         struct learning_pkt pkt;
 800         int size = sizeof(struct learning_pkt);
 801         int i;
 802
 803         memset(&pkt, 0, size);
 804         memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
 805         memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
 806         pkt.type = __constant_htons(ETH_P_LOOP);
 807
 808         for (i = 0; i < MAX_LP_RETRY; i++) {
 809                 struct sk_buff *skb;
 810                 char *data;
 811
 812                 skb = dev_alloc_skb(size);
 813                 if (!skb) {
 814                         return;
 815                 }
 816
 817                 data = skb_put(skb, size);
 818                 memcpy(data, &pkt, size);
 819                 skb->mac.raw = data;
 820                 skb->nh.raw = data + ETH_HLEN;
 821                 skb->protocol = pkt.type;
 822                 skb->priority = TC_PRIO_CONTROL;
 823                 skb->dev = slave->dev;
 824                 dev_queue_xmit(skb);
 825         }
 826
 827 }
 828
 829 /* hw is a boolean parameter that determines whether we should try and
 830  * set the hw address of the device as well as the hw address of the
 831  * net_device
 832  */
 833 static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
 834 {
 835         struct net_device *dev = slave->dev;
 836         struct sockaddr s_addr;
 837
 838         if (!hw) {
 839                 memcpy(dev->dev_addr, addr, dev->addr_len);
 840                 return 0;
 841         }
 842
 843         /* for rlb each slave must have a unique hw mac addresses so that */
 844         /* each slave will receive packets destined to a different mac */
 845         memcpy(s_addr.sa_data, addr, dev->addr_len);
 846         s_addr.sa_family = dev->type;
 847         if (dev->set_mac_address(dev, &s_addr)) {
 848                 printk(KERN_ERR DRV_NAME
 849                        ": Error: dev->set_mac_address of dev %s failed! ALB "
 850                        "mode requires that the base driver support setting "
 851                        "the hw address also when the network device's "
 852                        "interface is open\n",
 853                        dev->name);
 854                 return -EOPNOTSUPP;
 855         }
 856         return 0;
 857 }
 858
 859 /* Caller must hold bond lock for write or curr_slave_lock for write*/
 860 static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
 861 {
 862         struct slave *disabled_slave = NULL;
 863         u8 tmp_mac_addr[ETH_ALEN];
 864         int slaves_state_differ;
 865
 866         slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
 867
 868         memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
 869         alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
 870         alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);
 871
 872         /* fasten the change in the switch */
 873         if (SLAVE_IS_OK(slave1)) {
 874                 alb_send_learning_packets(slave1, slave1->dev->dev_addr);
 875                 if (bond->alb_info.rlb_enabled) {
 876                         /* inform the clients that the mac address
 877                          * has changed
 878                          */
 879                         rlb_req_update_slave_clients(bond, slave1);
 880                 }
 881         } else {
 882                 disabled_slave = slave1;
 883         }
 884
 885         if (SLAVE_IS_OK(slave2)) {
 886                 alb_send_learning_packets(slave2, slave2->dev->dev_addr);
 887                 if (bond->alb_info.rlb_enabled) {
 888                         /* inform the clients that the mac address
 889                          * has changed
 890                          */
 891                         rlb_req_update_slave_clients(bond, slave2);
 892                 }
 893         } else {
 894                 disabled_slave = slave2;
 895         }
 896
 897         if (bond->alb_info.rlb_enabled && slaves_state_differ) {
 898                         /* A disabled slave was assigned an active mac addr */
 899                         rlb_teach_disabled_mac_on_primary(bond,
 900                                 disabled_slave->dev->dev_addr);
 901         }
 902 }
 903
 904 /**
 905  * alb_change_hw_addr_on_detach
 906  * @bond: bonding we're working on
 907  * @slave: the slave that was just detached
 908  *
 909  * We assume that @slave was already detached from the slave list.
 910  *
 911  * If @slave's permanent hw address is different both from its current
 912  * address and from @bond's address, then somewhere in the bond there's
 913  * a slave that has @slave's permanet address as its current address.
 914  * We'll make sure that that slave no longer uses @slave's permanent address.
 915  *
 916  * Caller must hold bond lock
 917  */
 918 static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
 919 {
 920         struct slave *tmp_slave;
 921         int perm_curr_diff;
 922         int perm_bond_diff;
 923         int i, found = 0;
 924
 925         perm_curr_diff = memcmp(slave->perm_hwaddr,
 926                                 slave->dev->dev_addr,
 927                                 ETH_ALEN);
 928         perm_bond_diff = memcmp(slave->perm_hwaddr,
 929                                 bond->dev->dev_addr,
 930                                 ETH_ALEN);
 931         if (perm_curr_diff && perm_bond_diff) {
 932                 bond_for_each_slave(bond, tmp_slave, i) {
 933                         if (!memcmp(slave->perm_hwaddr,
 934                                    tmp_slave->dev->dev_addr,
 935                                    ETH_ALEN)) {
 936                                 found = 1;
 937                                 break;
 938                         }
 939                 }
 940
 941                 if (found) {
 942                         alb_swap_mac_addr(bond, slave, tmp_slave);
 943                 }
 944         }
 945 }
 946
 947 /**
 948  * alb_handle_addr_collision_on_attach
 949  * @bond: bonding we're working on
 950  * @slave: the slave that was just attached
 951  *
 952  * checks uniqueness of slave's mac address and handles the case the
 953  * new slave uses the bonds mac address.
 954  *
 955  * If the permanent hw address of @slave is @bond's hw address, we need to
 956  * find a different hw address to give @slave, that isn't in use by any other
 957  * slave in the bond. This address must be, of course, one of the premanent
 958  * addresses of the other slaves.
 959  *
 960  * We go over the slave list, and for each slave there we compare its
 961  * permanent hw address with the current address of all the other slaves.
 962  * If no match was found, then we've found a slave with a permanent address
 963  * that isn't used by any other slave in the bond, so we can assign it to
 964  * @slave.
 965  *
 966  * assumption: this function is called before @slave is attached to the
 967  *             bond slave list.
 968  *
 969  * caller must hold the bond lock for write since the mac addresses are compared
 970  * and may be swapped.
 971  */
 972 static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
 973 {
 974         struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
 975         int i, j, found = 0;
 976
 977         if (bond->slave_cnt == 0) {
 978                 /* this is the first slave */
 979                 return 0;
 980         }
 981
 982         /* if slave's mac address differs from bond's mac address
 983          * check uniqueness of slave's mac address against the other
 984          * slaves in the bond.
 985          */
 986         if (memcmp(slave->perm_hwaddr, bond->dev->dev_addr, ETH_ALEN)) {
 987                 bond_for_each_slave(bond, tmp_slave1, i) {
 988                         if (!memcmp(tmp_slave1->dev->dev_addr, slave->dev->dev_addr,
 989                                     ETH_ALEN)) {
 990                                 found = 1;
 991                                 break;
 992                         }
 993                 }
 994                 if (found) {
 995                         /* a slave was found that is using the mac address
 996                          * of the new slave
 997                          */
 998                         printk(KERN_ERR DRV_NAME
 999                                ": Error: the hw address of slave %s is not "
1000                                "unique - cannot enslave it!",
1001                                slave->dev->name);
1002                         return -EINVAL;
1003                 }
1004                 return 0;
1005         }
1006
1007         /* the slave's address is equal to the address of the bond
1008          * search for a spare address in the bond for this slave.
1009          */
1010         free_mac_slave = NULL;
1011
1012         bond_for_each_slave(bond, tmp_slave1, i) {
1013                 found = 0;
1014                 bond_for_each_slave(bond, tmp_slave2, j) {
1015                         if (!memcmp(tmp_slave1->perm_hwaddr,
1016                                     tmp_slave2->dev->dev_addr,
1017                                     ETH_ALEN)) {
1018                                 found = 1;
1019                                 break;
1020                         }
1021                 }
1022
1023                 if (!found) {
1024                         /* no slave has tmp_slave1's perm addr
1025                          * as its curr addr
1026                          */
1027                         free_mac_slave = tmp_slave1;
1028                         break;
1029                 }
1030         }
1031
1032         if (free_mac_slave) {
1033                 alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr,
1034                                        bond->alb_info.rlb_enabled);
1035
1036                 printk(KERN_WARNING DRV_NAME
1037                        ": Warning: the hw address of slave %s is in use by "
1038                        "the bond; giving it the hw address of %s\n",
1039                        slave->dev->name, free_mac_slave->dev->name);
1040         } else {
1041                 printk(KERN_ERR DRV_NAME
1042                        ": Error: the hw address of slave %s is in use by the "
1043                        "bond; couldn't find a slave with a free hw address to "
1044                        "give it (this should not have happened)\n",
1045                        slave->dev->name);
1046                 return -EFAULT;
1047         }
1048
1049         return 0;
1050 }
1051
1052 /**
1053  * alb_set_mac_address
1054  * @bond:
1055  * @addr:
1056  *
1057  * In TLB mode all slaves are configured to the bond's hw address, but set
1058  * their dev_addr field to different addresses (based on their permanent hw
1059  * addresses).
1060  *
1061  * For each slave, this function sets the interface to the new address and then
1062  * changes its dev_addr field to its previous value.
1063  *
1064  * Unwinding assumes bond's mac address has not yet changed.
1065  */
1066 static int alb_set_mac_address(struct bonding *bond, void *addr)
1067 {
1068         struct sockaddr sa;
1069         struct slave *slave, *stop_at;
1070         char tmp_addr[ETH_ALEN];
1071         int res;
1072         int i;
1073
1074         if (bond->alb_info.rlb_enabled) {
1075                 return 0;
1076         }
1077
1078         bond_for_each_slave(bond, slave, i) {
1079                 if (slave->dev->set_mac_address == NULL) {
1080                         res = -EOPNOTSUPP;
1081                         goto unwind;
1082                 }
1083
1084                 /* save net_device's current hw address */
1085                 memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1086
1087                 res = slave->dev->set_mac_address(slave->dev, addr);
1088
1089                 /* restore net_device's hw address */
1090                 memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1091
1092                 if (res) {
1093                         goto unwind;
1094                 }
1095         }
1096
1097         return 0;
1098
1099 unwind:
1100         memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
1101         sa.sa_family = bond->dev->type;
1102
1103         /* unwind from head to the slave that failed */
1104         stop_at = slave;
1105         bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
1106                 memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
1107                 slave->dev->set_mac_address(slave->dev, &sa);
1108                 memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
1109         }
1110
1111         return res;
1112 }
1113
1114 /************************ exported alb funcions ************************/
1115
1116 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
1117 {
1118         int res;
1119
1120         res = tlb_initialize(bond);
1121         if (res) {
1122                 return res;
1123         }
1124
1125         if (rlb_enabled) {
1126                 bond->alb_info.rlb_enabled = 1;
1127                 /* initialize rlb */
1128                 res = rlb_initialize(bond);
1129                 if (res) {
1130                         tlb_deinitialize(bond);
1131                         return res;
1132                 }
1133         }
1134
1135         return 0;
1136 }
1137
1138 void bond_alb_deinitialize(struct bonding *bond)
1139 {
1140         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1141
1142         tlb_deinitialize(bond);
1143
1144         if (bond_info->rlb_enabled) {
1145                 rlb_deinitialize(bond);
1146         }
1147 }
1148
1149 int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
1150 {
1151         struct bonding *bond = (struct bonding *)bond_dev->priv;
1152         struct ethhdr *eth_data = (struct ethhdr *)skb->mac.raw = skb->data;
1153         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1154         struct slave *tx_slave = NULL;
1155         static u32 ip_bcast = 0xffffffff;
1156         int hash_size = 0;
1157         int do_tx_balance = 1;
1158         u32 hash_index = 0;
1159         u8 *hash_start = NULL;
1160
1161         /* make sure that the curr_active_slave and the slaves list do
1162          * not change during tx
1163          */
1164         read_lock(&bond->lock);
1165         read_lock(&bond->curr_slave_lock);
1166
1167         if (!BOND_IS_OK(bond)) {
1168                 goto free_out;
1169         }
1170
1171         switch (ntohs(skb->protocol)) {
1172         case ETH_P_IP:
1173                 if ((memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) ||
1174                     (skb->nh.iph->daddr == ip_bcast)) {
1175                         do_tx_balance = 0;
1176                         break;
1177                 }
1178                 hash_start = (char*)&(skb->nh.iph->daddr);
1179                 hash_size = sizeof(skb->nh.iph->daddr);
1180                 break;
1181
1182         case ETH_P_IPV6:
1183                 if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
1184                         do_tx_balance = 0;
1185                         break;
1186                 }
1187
1188                 hash_start = (char*)&(skb->nh.ipv6h->daddr);
1189                 hash_size = sizeof(skb->nh.ipv6h->daddr);
1190                 break;
1191
1192         case ETH_P_IPX:
1193                 if (ipx_hdr(skb)->ipx_checksum !=
1194                     __constant_htons(IPX_NO_CHECKSUM)) {
1195                         /* something is wrong with this packet */
1196                         do_tx_balance = 0;
1197                         break;
1198                 }
1199
1200                 if (ipx_hdr(skb)->ipx_type !=
1201                     __constant_htons(IPX_TYPE_NCP)) {
1202                         /* The only protocol worth balancing in
1203                          * this family since it has an "ARP" like
1204                          * mechanism
1205                          */
1206                         do_tx_balance = 0;
1207                         break;
1208                 }
1209
1210                 hash_start = (char*)eth_data->h_dest;
1211                 hash_size = ETH_ALEN;
1212                 break;
1213
1214         case ETH_P_ARP:
1215                 do_tx_balance = 0;
1216                 if (bond_info->rlb_enabled) {
1217                         tx_slave = rlb_arp_xmit(skb, bond);
1218                 }
1219                 break;
1220
1221         default:
1222                 do_tx_balance = 0;
1223                 break;
1224         }
1225
1226         if (do_tx_balance) {
1227                 hash_index = _simple_hash(hash_start, hash_size);
1228                 tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
1229         }
1230
1231         if (!tx_slave) {
1232                 /* unbalanced or unassigned, send through primary */
1233                 tx_slave = bond->curr_active_slave;
1234                 bond_info->unbalanced_load += skb->len;
1235         }
1236
1237         if (tx_slave && SLAVE_IS_OK(tx_slave)) {
1238                 skb->dev = tx_slave->dev;
1239                 if (tx_slave != bond->curr_active_slave) {
1240                         memcpy(eth_data->h_source,
1241                                 tx_slave->dev->dev_addr,
1242                                 ETH_ALEN);
1243                 }
1244                 dev_queue_xmit(skb);
1245         } else {
1246                 /* no suitable interface, frame not sent */
1247                 if (tx_slave) {
1248                         tlb_clear_slave(bond, tx_slave, 0);
1249                 }
1250                 goto free_out;
1251         }
1252
1253 out:
1254         read_unlock(&bond->curr_slave_lock);
1255         read_unlock(&bond->lock);
1256         return 0;
1257
1258 free_out:
1259         dev_kfree_skb(skb);
1260         goto out;
1261 }
1262
1263 void bond_alb_monitor(struct bonding *bond)
1264 {
1265         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1266         struct slave *slave;
1267         int delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
1268         int i;
1269
1270         read_lock(&bond->lock);
1271
1272         if (bond->kill_timers) {
1273                 goto out;
1274         }
1275
1276         if (bond->slave_cnt == 0) {
1277                 bond_info->tx_rebalance_counter = 0;
1278                 bond_info->lp_counter = 0;
1279                 goto re_arm;
1280         }
1281
1282         bond_info->tx_rebalance_counter++;
1283         bond_info->lp_counter++;
1284
1285         /* send learning packets */
1286         if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
1287                 /* change of curr_active_slave involves swapping of mac addresses.
1288                  * in order to avoid this swapping from happening while
1289                  * sending the learning packets, the curr_slave_lock must be held for
1290                  * read.
1291                  */
1292                 read_lock(&bond->curr_slave_lock);
1293                 bond_for_each_slave(bond, slave, i) {
1294                         alb_send_learning_packets(slave,slave->dev->dev_addr);
1295                 }
1296                 read_unlock(&bond->curr_slave_lock);
1297
1298                 bond_info->lp_counter = 0;
1299         }
1300
1301         /* rebalance tx traffic */
1302         if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {
1303                 read_lock(&bond->curr_slave_lock);
1304                 bond_for_each_slave(bond, slave, i) {
1305                         tlb_clear_slave(bond, slave, 1);
1306                         if (slave == bond->curr_active_slave) {
1307                                 SLAVE_TLB_INFO(slave).load =
1308                                         bond_info->unbalanced_load /
1309                                                 BOND_TLB_REBALANCE_INTERVAL;
1310                                 bond_info->unbalanced_load = 0;
1311                         }
1312                 }
1313                 read_unlock(&bond->curr_slave_lock);
1314                 bond_info->tx_rebalance_counter = 0;
1315         }
1316
1317         /* handle rlb stuff */
1318         if (bond_info->rlb_enabled) {
1319                 /* the following code changes the promiscuity of the
1320                  * the curr_active_slave. It needs to be locked with a
1321                  * write lock to protect from other code that also
1322                  * sets the promiscuity.
1323                  */
1324                 write_lock(&bond->curr_slave_lock);
1325                 if (bond_info->primary_is_promisc &&
1326                     (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {
1327
1328                         bond_info->rlb_promisc_timeout_counter = 0;
1329
1330                         /* If the primary was set to promiscuous mode
1331                          * because a slave was disabled then
1332                          * it can now leave promiscuous mode.
1333                          */
1334                         dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1335                         bond_info->primary_is_promisc = 0;
1336                 }
1337                 write_unlock(&bond->curr_slave_lock);
1338
1339                 if (bond_info->rlb_rebalance) {
1340                         bond_info->rlb_rebalance = 0;
1341                         rlb_rebalance(bond);
1342                 }
1343
1344                 /* check if clients need updating */
1345                 if (bond_info->rx_ntt) {
1346                         if (bond_info->rlb_update_delay_counter) {
1347                                 --bond_info->rlb_update_delay_counter;
1348                         } else {
1349                                 rlb_update_rx_clients(bond);
1350                                 if (bond_info->rlb_update_retry_counter) {
1351                                         --bond_info->rlb_update_retry_counter;
1352                                 } else {
1353                                         bond_info->rx_ntt = 0;
1354                                 }
1355                         }
1356                 }
1357         }
1358
1359 re_arm:
1360         mod_timer(&(bond_info->alb_timer), jiffies + delta_in_ticks);
1361 out:
1362         read_unlock(&bond->lock);
1363 }
1364
1365 /* assumption: called before the slave is attached to the bond
1366  * and not locked by the bond lock
1367  */
1368 int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
1369 {
1370         int res;
1371
1372         res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr,
1373                                      bond->alb_info.rlb_enabled);
1374         if (res) {
1375                 return res;
1376         }
1377
1378         /* caller must hold the bond lock for write since the mac addresses
1379          * are compared and may be swapped.
1380          */
1381         write_lock_bh(&bond->lock);
1382
1383         res = alb_handle_addr_collision_on_attach(bond, slave);
1384
1385         write_unlock_bh(&bond->lock);
1386
1387         if (res) {
1388                 return res;
1389         }
1390
1391         tlb_init_slave(slave);
1392
1393         /* order a rebalance ASAP */
1394         bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1395
1396         if (bond->alb_info.rlb_enabled) {
1397                 bond->alb_info.rlb_rebalance = 1;
1398         }
1399
1400         return 0;
1401 }
1402
1403 /* Caller must hold bond lock for write */
1404 void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
1405 {
1406         if (bond->slave_cnt > 1) {
1407                 alb_change_hw_addr_on_detach(bond, slave);
1408         }
1409
1410         tlb_clear_slave(bond, slave, 0);
1411
1412         if (bond->alb_info.rlb_enabled) {
1413                 bond->alb_info.next_rx_slave = NULL;
1414                 rlb_clear_slave(bond, slave);
1415         }
1416 }
1417
1418 /* Caller must hold bond lock for read */
1419 void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
1420 {
1421         struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
1422
1423         if (link == BOND_LINK_DOWN) {
1424                 tlb_clear_slave(bond, slave, 0);
1425                 if (bond->alb_info.rlb_enabled) {
1426                         rlb_clear_slave(bond, slave);
1427                 }
1428         } else if (link == BOND_LINK_UP) {
1429                 /* order a rebalance ASAP */
1430                 bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
1431                 if (bond->alb_info.rlb_enabled) {
1432                         bond->alb_info.rlb_rebalance = 1;
1433                         /* If the updelay module parameter is smaller than the
1434                          * forwarding delay of the switch the rebalance will
1435                          * not work because the rebalance arp replies will
1436                          * not be forwarded to the clients..
1437                          */
1438                 }
1439         }
1440 }
1441
1442 /**
1443  * bond_alb_handle_active_change - assign new curr_active_slave
1444  * @bond: our bonding struct
1445  * @new_slave: new slave to assign
1446  *
1447  * Set the bond->curr_active_slave to @new_slave and handle
1448  * mac address swapping and promiscuity changes as needed.
1449  *
1450  * Caller must hold bond curr_slave_lock for write (or bond lock for write)
1451  */
1452 void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
1453 {
1454         struct slave *swap_slave;
1455         int i, found = 0;
1456
1457         if (bond->curr_active_slave == new_slave) {
1458                 return;
1459         }
1460
1461         if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
1462                 dev_set_promiscuity(bond->curr_active_slave->dev, -1);
1463                 bond->alb_info.primary_is_promisc = 0;
1464                 bond->alb_info.rlb_promisc_timeout_counter = 0;
1465         }
1466
1467         swap_slave = bond->curr_active_slave;
1468         bond->curr_active_slave = new_slave;
1469
1470         if (!new_slave || (bond->slave_cnt == 0)) {
1471                 return;
1472         }
1473
1474         /* set the new curr_active_slave to the bonds mac address
1475          * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
1476          */
1477         if (!swap_slave) {
1478                 /* find slave that is holding the bond's mac address */
1479                 bond_for_each_slave(bond, swap_slave, i) {
1480                         if (!memcmp(swap_slave->dev->dev_addr,
1481                                 bond->dev->dev_addr, ETH_ALEN)) {
1482                                 found = 1;
1483                                 break;
1484                         }
1485                 }
1486         }
1487
1488         /* curr_active_slave must be set before calling alb_swap_mac_addr */
1489         if (found) {
1490                 /* swap mac address */
1491                 alb_swap_mac_addr(bond, swap_slave, new_slave);
1492         } else {
1493                 /* set the new_slave to the bond mac address */
1494                 alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
1495                                        bond->alb_info.rlb_enabled);
1496                 /* fasten bond mac on new current slave */
1497                 alb_send_learning_packets(new_slave, bond->dev->dev_addr);
1498         }
1499 }
1500
1501 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
1502 {
1503         struct bonding *bond = (struct bonding *)bond_dev->priv;
1504         struct sockaddr *sa = addr;
1505         struct slave *swap_slave;
1506         int res;
1507         int i, found = 0;
1508
1509         if (!is_valid_ether_addr(sa->sa_data)) {
1510                 return -EADDRNOTAVAIL;
1511         }
1512
1513         res = alb_set_mac_address(bond, addr);
1514         if (res) {
1515                 return res;
1516         }
1517
1518         memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);
1519
1520         /* If there is no curr_active_slave there is nothing else to do.
1521          * Otherwise we'll need to pass the new address to it and handle
1522          * duplications.
1523          */
1524         if (!bond->curr_active_slave) {
1525                 return 0;
1526         }
1527
1528         bond_for_each_slave(bond, swap_slave, i) {
1529                 if (!memcmp(swap_slave->dev->dev_addr, bond_dev->dev_addr, ETH_ALEN)) {
1530                         found = 1;
1531                         break;
1532                 }
1533         }
1534
1535         if (found) {
1536                 alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
1537         } else {
1538                 alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
1539                                        bond->alb_info.rlb_enabled);
1540
1541                 alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
1542                 if (bond->alb_info.rlb_enabled) {
1543                         /* inform clients mac address has changed */
1544                         rlb_req_update_slave_clients(bond, bond->curr_active_slave);
1545                 }
1546         }
1547
1548         return 0;
1549 }
1550