bond_alb.c

Go to the documentation of this file.

/*
 * Copyright(c) 1999 - 2004 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/pkt_sched.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_bonding.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <net/ipx.h>
#include <net/arp.h>
#include <net/ipv6.h>
#include <asm/byteorder.h>
#include "bonding.h"
#include "bond_alb.h"



#ifndef __long_aligned
#define __long_aligned __attribute__((aligned((sizeof(long)))))
#endif
static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};
static const u8 mac_v6_allmcast[ETH_ALEN] __long_aligned = {
    0x33, 0x33, 0x00, 0x00, 0x00, 0x01
};
static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;

#pragma pack(1)
struct learning_pkt {
    u8 mac_dst[ETH_ALEN];
    u8 mac_src[ETH_ALEN];
    __be16 type;
    u8 padding[ETH_ZLEN - ETH_HLEN];
};

struct arp_pkt {
    __be16  hw_addr_space;
    __be16  prot_addr_space;
    u8      hw_addr_len;
    u8      prot_addr_len;
    __be16  op_code;
    u8      mac_src[ETH_ALEN];  /* sender hardware address */
    __be32  ip_src;         /* sender IP address */
    u8      mac_dst[ETH_ALEN];  /* target hardware address */
    __be32  ip_dst;         /* target IP address */
};
#pragma pack()

static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
{
    return (struct arp_pkt *)skb_network_header(skb);
}

/* Forward declaration */
static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);

static inline u8 _simple_hash(const u8 *hash_start, int hash_size)
{
    int i;
    u8 hash = 0;

    for (i = 0; i < hash_size; i++) {
        hash ^= hash_start[i];
    }

    return hash;
}

/*********************** tlb specific functions ***************************/

static inline void _lock_tx_hashtbl_bh(struct bonding *bond)
{
    spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

static inline void _unlock_tx_hashtbl_bh(struct bonding *bond)
{
    spin_unlock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

static inline void _lock_tx_hashtbl(struct bonding *bond)
{
    spin_lock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

static inline void _unlock_tx_hashtbl(struct bonding *bond)
{
    spin_unlock(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

/* Caller must hold tx_hashtbl lock */
static inline void tlb_init_table_entry(struct tlb_client_info *entry, int save_load)
{
    if (save_load) {
        entry->load_history = 1 + entry->tx_bytes /
                      BOND_TLB_REBALANCE_INTERVAL;
        entry->tx_bytes = 0;
    }

    entry->tx_slave = NULL;
    entry->next = TLB_NULL_INDEX;
    entry->prev = TLB_NULL_INDEX;
}

static inline void tlb_init_slave(struct slave *slave)
{
    SLAVE_TLB_INFO(slave).load = 0;
    SLAVE_TLB_INFO(slave).head = TLB_NULL_INDEX;
}

/* Caller must hold bond lock for read, BH disabled */
static void __tlb_clear_slave(struct bonding *bond, struct slave *slave,
             int save_load)
{
    struct tlb_client_info *tx_hash_table;
    u32 index;

    /* clear slave from tx_hashtbl */
    tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl;

    /* skip this if we've already freed the tx hash table */
    if (tx_hash_table) {
        index = SLAVE_TLB_INFO(slave).head;
        while (index != TLB_NULL_INDEX) {
            u32 next_index = tx_hash_table[index].next;
            tlb_init_table_entry(&tx_hash_table[index], save_load);
            index = next_index;
        }
    }

    tlb_init_slave(slave);
}

/* Caller must hold bond lock for read */
static void tlb_clear_slave(struct bonding *bond, struct slave *slave,
             int save_load)
{
    _lock_tx_hashtbl_bh(bond);
    __tlb_clear_slave(bond, slave, save_load);
    _unlock_tx_hashtbl_bh(bond);
}

/* Must be called before starting the monitor timer */
static int tlb_initialize(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    int size = TLB_HASH_TABLE_SIZE * sizeof(struct tlb_client_info);
    struct tlb_client_info *new_hashtbl;
    int i;

    new_hashtbl = kzalloc(size, GFP_KERNEL);
    if (!new_hashtbl)
        return -1;

    _lock_tx_hashtbl_bh(bond);

    bond_info->tx_hashtbl = new_hashtbl;

    for (i = 0; i < TLB_HASH_TABLE_SIZE; i++) {
        tlb_init_table_entry(&bond_info->tx_hashtbl[i], 0);
    }

    _unlock_tx_hashtbl_bh(bond);

    return 0;
}

/* Must be called only after all slaves have been released */
static void tlb_deinitialize(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

    _lock_tx_hashtbl_bh(bond);

    kfree(bond_info->tx_hashtbl);
    bond_info->tx_hashtbl = NULL;

    _unlock_tx_hashtbl_bh(bond);
}

static long long compute_gap(struct slave *slave)
{
    return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
           (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
}

/* Caller must hold bond lock for read */
static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
{
    struct slave *slave, *least_loaded;
    long long max_gap;
    int i;

    least_loaded = NULL;
    max_gap = LLONG_MIN;

    /* Find the slave with the largest gap */
    bond_for_each_slave(bond, slave, i) {
        if (SLAVE_IS_OK(slave)) {
            long long gap = compute_gap(slave);

            if (max_gap < gap) {
                least_loaded = slave;
                max_gap = gap;
            }
        }
    }

    return least_loaded;
}

static struct slave *__tlb_choose_channel(struct bonding *bond, u32 hash_index,
                        u32 skb_len)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct tlb_client_info *hash_table;
    struct slave *assigned_slave;

    hash_table = bond_info->tx_hashtbl;
    assigned_slave = hash_table[hash_index].tx_slave;
    if (!assigned_slave) {
        assigned_slave = tlb_get_least_loaded_slave(bond);

        if (assigned_slave) {
            struct tlb_slave_info *slave_info =
                &(SLAVE_TLB_INFO(assigned_slave));
            u32 next_index = slave_info->head;

            hash_table[hash_index].tx_slave = assigned_slave;
            hash_table[hash_index].next = next_index;
            hash_table[hash_index].prev = TLB_NULL_INDEX;

            if (next_index != TLB_NULL_INDEX) {
                hash_table[next_index].prev = hash_index;
            }

            slave_info->head = hash_index;
            slave_info->load +=
                hash_table[hash_index].load_history;
        }
    }

    if (assigned_slave) {
        hash_table[hash_index].tx_bytes += skb_len;
    }

    return assigned_slave;
}

/* Caller must hold bond lock for read */
static struct slave *tlb_choose_channel(struct bonding *bond, u32 hash_index,
                    u32 skb_len)
{
    struct slave *tx_slave;
    /*
     * We don't need to disable softirq here, becase
     * tlb_choose_channel() is only called by bond_alb_xmit()
     * which already has softirq disabled.
     */
    _lock_tx_hashtbl(bond);
    tx_slave = __tlb_choose_channel(bond, hash_index, skb_len);
    _unlock_tx_hashtbl(bond);
    return tx_slave;
}

/*********************** rlb specific functions ***************************/
static inline void _lock_rx_hashtbl_bh(struct bonding *bond)
{
    spin_lock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

static inline void _unlock_rx_hashtbl_bh(struct bonding *bond)
{
    spin_unlock_bh(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

static inline void _lock_rx_hashtbl(struct bonding *bond)
{
    spin_lock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

static inline void _unlock_rx_hashtbl(struct bonding *bond)
{
    spin_unlock(&(BOND_ALB_INFO(bond).rx_hashtbl_lock));
}

/* when an ARP REPLY is received from a client update its info
 * in the rx_hashtbl
 */
static void rlb_update_entry_from_arp(struct bonding *bond, struct arp_pkt *arp)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info *client_info;
    u32 hash_index;

    _lock_rx_hashtbl_bh(bond);

    hash_index = _simple_hash((u8*)&(arp->ip_src), sizeof(arp->ip_src));
    client_info = &(bond_info->rx_hashtbl[hash_index]);

    if ((client_info->assigned) &&
        (client_info->ip_src == arp->ip_dst) &&
        (client_info->ip_dst == arp->ip_src) &&
        (!ether_addr_equal_64bits(client_info->mac_dst, arp->mac_src))) {
        /* update the clients MAC address */
        memcpy(client_info->mac_dst, arp->mac_src, ETH_ALEN);
        client_info->ntt = 1;
        bond_info->rx_ntt = 1;
    }

    _unlock_rx_hashtbl_bh(bond);
}

static int rlb_arp_recv(const struct sk_buff *skb, struct bonding *bond,
            struct slave *slave)
{
    struct arp_pkt *arp, _arp;

    if (skb->protocol != cpu_to_be16(ETH_P_ARP))
        goto out;

    arp = skb_header_pointer(skb, 0, sizeof(_arp), &_arp);
    if (!arp)
        goto out;

    if (arp->op_code == htons(ARPOP_REPLY)) {
        /* update rx hash table for this ARP */
        rlb_update_entry_from_arp(bond, arp);
        pr_debug("Server received an ARP Reply from client\n");
    }
out:
    return RX_HANDLER_ANOTHER;
}

/* Caller must hold bond lock for read */
static struct slave *rlb_next_rx_slave(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct slave *rx_slave, *slave, *start_at;
    int i = 0;

    if (bond_info->next_rx_slave) {
        start_at = bond_info->next_rx_slave;
    } else {
        start_at = bond->first_slave;
    }

    rx_slave = NULL;

    bond_for_each_slave_from(bond, slave, i, start_at) {
        if (SLAVE_IS_OK(slave)) {
            if (!rx_slave) {
                rx_slave = slave;
            } else if (slave->speed > rx_slave->speed) {
                rx_slave = slave;
            }
        }
    }

    if (rx_slave) {
        bond_info->next_rx_slave = rx_slave->next;
    }

    return rx_slave;
}

/* teach the switch the mac of a disabled slave
 * on the primary for fault tolerance
 *
 * Caller must hold bond->curr_slave_lock for write or bond lock for write
 */
static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
{
    if (!bond->curr_active_slave) {
        return;
    }

    if (!bond->alb_info.primary_is_promisc) {
        if (!dev_set_promiscuity(bond->curr_active_slave->dev, 1))
            bond->alb_info.primary_is_promisc = 1;
        else
            bond->alb_info.primary_is_promisc = 0;
    }

    bond->alb_info.rlb_promisc_timeout_counter = 0;

    alb_send_learning_packets(bond->curr_active_slave, addr);
}

/* slave being removed should not be active at this point
 *
 * Caller must hold bond lock for read
 */
static void rlb_clear_slave(struct bonding *bond, struct slave *slave)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info *rx_hash_table;
    u32 index, next_index;

    /* clear slave from rx_hashtbl */
    _lock_rx_hashtbl_bh(bond);

    rx_hash_table = bond_info->rx_hashtbl;
    index = bond_info->rx_hashtbl_head;
    for (; index != RLB_NULL_INDEX; index = next_index) {
        next_index = rx_hash_table[index].next;
        if (rx_hash_table[index].slave == slave) {
            struct slave *assigned_slave = rlb_next_rx_slave(bond);

            if (assigned_slave) {
                rx_hash_table[index].slave = assigned_slave;
                if (!ether_addr_equal_64bits(rx_hash_table[index].mac_dst,
                                 mac_bcast)) {
                    bond_info->rx_hashtbl[index].ntt = 1;
                    bond_info->rx_ntt = 1;
                    /* A slave has been removed from the
                     * table because it is either disabled
                     * or being released. We must retry the
                     * update to avoid clients from not
                     * being updated & disconnecting when
                     * there is stress
                     */
                    bond_info->rlb_update_retry_counter =
                        RLB_UPDATE_RETRY;
                }
            } else {  /* there is no active slave */
                rx_hash_table[index].slave = NULL;
            }
        }
    }

    _unlock_rx_hashtbl_bh(bond);

    write_lock_bh(&bond->curr_slave_lock);

    if (slave != bond->curr_active_slave) {
        rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
    }

    write_unlock_bh(&bond->curr_slave_lock);
}

static void rlb_update_client(struct rlb_client_info *client_info)
{
    int i;

    if (!client_info->slave) {
        return;
    }

    for (i = 0; i < RLB_ARP_BURST_SIZE; i++) {
        struct sk_buff *skb;

        skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
                 client_info->ip_dst,
                 client_info->slave->dev,
                 client_info->ip_src,
                 client_info->mac_dst,
                 client_info->slave->dev->dev_addr,
                 client_info->mac_dst);
        if (!skb) {
            pr_err("%s: Error: failed to create an ARP packet\n",
                   client_info->slave->dev->master->name);
            continue;
        }

        skb->dev = client_info->slave->dev;

        if (client_info->tag) {
            skb = vlan_put_tag(skb, client_info->vlan_id);
            if (!skb) {
                pr_err("%s: Error: failed to insert VLAN tag\n",
                       client_info->slave->dev->master->name);
                continue;
            }
        }

        arp_xmit(skb);
    }
}

/* sends ARP REPLIES that update the clients that need updating */
static void rlb_update_rx_clients(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info *client_info;
    u32 hash_index;

    _lock_rx_hashtbl_bh(bond);

    hash_index = bond_info->rx_hashtbl_head;
    for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
        client_info = &(bond_info->rx_hashtbl[hash_index]);
        if (client_info->ntt) {
            rlb_update_client(client_info);
            if (bond_info->rlb_update_retry_counter == 0) {
                client_info->ntt = 0;
            }
        }
    }

    /* do not update the entries again until this counter is zero so that
     * not to confuse the clients.
     */
    bond_info->rlb_update_delay_counter = RLB_UPDATE_DELAY;

    _unlock_rx_hashtbl_bh(bond);
}

/* The slave was assigned a new mac address - update the clients */
static void rlb_req_update_slave_clients(struct bonding *bond, struct slave *slave)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info *client_info;
    int ntt = 0;
    u32 hash_index;

    _lock_rx_hashtbl_bh(bond);

    hash_index = bond_info->rx_hashtbl_head;
    for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
        client_info = &(bond_info->rx_hashtbl[hash_index]);

        if ((client_info->slave == slave) &&
            !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
            client_info->ntt = 1;
            ntt = 1;
        }
    }

    // update the team's flag only after the whole iteration
    if (ntt) {
        bond_info->rx_ntt = 1;
        //fasten the change
        bond_info->rlb_update_retry_counter = RLB_UPDATE_RETRY;
    }

    _unlock_rx_hashtbl_bh(bond);
}

/* mark all clients using src_ip to be updated */
static void rlb_req_update_subnet_clients(struct bonding *bond, __be32 src_ip)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info *client_info;
    u32 hash_index;

    _lock_rx_hashtbl(bond);

    hash_index = bond_info->rx_hashtbl_head;
    for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
        client_info = &(bond_info->rx_hashtbl[hash_index]);

        if (!client_info->slave) {
            pr_err("%s: Error: found a client with no channel in the client's hash table\n",
                   bond->dev->name);
            continue;
        }
        /*update all clients using this src_ip, that are not assigned
         * to the team's address (curr_active_slave) and have a known
         * unicast mac address.
         */
        if ((client_info->ip_src == src_ip) &&
            !ether_addr_equal_64bits(client_info->slave->dev->dev_addr,
                         bond->dev->dev_addr) &&
            !ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
            client_info->ntt = 1;
            bond_info->rx_ntt = 1;
        }
    }

    _unlock_rx_hashtbl(bond);
}

/* Caller must hold both bond and ptr locks for read */
static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct arp_pkt *arp = arp_pkt(skb);
    struct slave *assigned_slave;
    struct rlb_client_info *client_info;
    u32 hash_index = 0;

    _lock_rx_hashtbl(bond);

    hash_index = _simple_hash((u8 *)&arp->ip_dst, sizeof(arp->ip_dst));
    client_info = &(bond_info->rx_hashtbl[hash_index]);

    if (client_info->assigned) {
        if ((client_info->ip_src == arp->ip_src) &&
            (client_info->ip_dst == arp->ip_dst)) {
            /* the entry is already assigned to this client */
            if (!ether_addr_equal_64bits(arp->mac_dst, mac_bcast)) {
                /* update mac address from arp */
                memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
            }

            assigned_slave = client_info->slave;
            if (assigned_slave) {
                _unlock_rx_hashtbl(bond);
                return assigned_slave;
            }
        } else {
            /* the entry is already assigned to some other client,
             * move the old client to primary (curr_active_slave) so
             * that the new client can be assigned to this entry.
             */
            if (bond->curr_active_slave &&
                client_info->slave != bond->curr_active_slave) {
                client_info->slave = bond->curr_active_slave;
                rlb_update_client(client_info);
            }
        }
    }
    /* assign a new slave */
    assigned_slave = rlb_next_rx_slave(bond);

    if (assigned_slave) {
        client_info->ip_src = arp->ip_src;
        client_info->ip_dst = arp->ip_dst;
        /* arp->mac_dst is broadcast for arp reqeusts.
         * will be updated with clients actual unicast mac address
         * upon receiving an arp reply.
         */
        memcpy(client_info->mac_dst, arp->mac_dst, ETH_ALEN);
        client_info->slave = assigned_slave;

        if (!ether_addr_equal_64bits(client_info->mac_dst, mac_bcast)) {
            client_info->ntt = 1;
            bond->alb_info.rx_ntt = 1;
        } else {
            client_info->ntt = 0;
        }

        if (bond_vlan_used(bond)) {
            if (!vlan_get_tag(skb, &client_info->vlan_id))
                client_info->tag = 1;
        }

        if (!client_info->assigned) {
            u32 prev_tbl_head = bond_info->rx_hashtbl_head;
            bond_info->rx_hashtbl_head = hash_index;
            client_info->next = prev_tbl_head;
            if (prev_tbl_head != RLB_NULL_INDEX) {
                bond_info->rx_hashtbl[prev_tbl_head].prev =
                    hash_index;
            }
            client_info->assigned = 1;
        }
    }

    _unlock_rx_hashtbl(bond);

    return assigned_slave;
}

/* chooses (and returns) transmit channel for arp reply
 * does not choose channel for other arp types since they are
 * sent on the curr_active_slave
 */
static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
{
    struct arp_pkt *arp = arp_pkt(skb);
    struct slave *tx_slave = NULL;

    if (arp->op_code == htons(ARPOP_REPLY)) {
        /* the arp must be sent on the selected
        * rx channel
        */
        tx_slave = rlb_choose_channel(skb, bond);
        if (tx_slave) {
            memcpy(arp->mac_src,tx_slave->dev->dev_addr, ETH_ALEN);
        }
        pr_debug("Server sent ARP Reply packet\n");
    } else if (arp->op_code == htons(ARPOP_REQUEST)) {
        /* Create an entry in the rx_hashtbl for this client as a
         * place holder.
         * When the arp reply is received the entry will be updated
         * with the correct unicast address of the client.
         */
        rlb_choose_channel(skb, bond);

        /* The ARP reply packets must be delayed so that
         * they can cancel out the influence of the ARP request.
         */
        bond->alb_info.rlb_update_delay_counter = RLB_UPDATE_DELAY;

        /* arp requests are broadcast and are sent on the primary
         * the arp request will collapse all clients on the subnet to
         * the primary slave. We must register these clients to be
         * updated with their assigned mac.
         */
        rlb_req_update_subnet_clients(bond, arp->ip_src);
        pr_debug("Server sent ARP Request packet\n");
    }

    return tx_slave;
}

/* Caller must hold bond lock for read */
static void rlb_rebalance(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct slave *assigned_slave;
    struct rlb_client_info *client_info;
    int ntt;
    u32 hash_index;

    _lock_rx_hashtbl_bh(bond);

    ntt = 0;
    hash_index = bond_info->rx_hashtbl_head;
    for (; hash_index != RLB_NULL_INDEX; hash_index = client_info->next) {
        client_info = &(bond_info->rx_hashtbl[hash_index]);
        assigned_slave = rlb_next_rx_slave(bond);
        if (assigned_slave && (client_info->slave != assigned_slave)) {
            client_info->slave = assigned_slave;
            client_info->ntt = 1;
            ntt = 1;
        }
    }

    /* update the team's flag only after the whole iteration */
    if (ntt) {
        bond_info->rx_ntt = 1;
    }
    _unlock_rx_hashtbl_bh(bond);
}

/* Caller must hold rx_hashtbl lock */
static void rlb_init_table_entry(struct rlb_client_info *entry)
{
    memset(entry, 0, sizeof(struct rlb_client_info));
    entry->next = RLB_NULL_INDEX;
    entry->prev = RLB_NULL_INDEX;
}

static int rlb_initialize(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct rlb_client_info  *new_hashtbl;
    int size = RLB_HASH_TABLE_SIZE * sizeof(struct rlb_client_info);
    int i;

    new_hashtbl = kmalloc(size, GFP_KERNEL);
    if (!new_hashtbl)
        return -1;

    _lock_rx_hashtbl_bh(bond);

    bond_info->rx_hashtbl = new_hashtbl;

    bond_info->rx_hashtbl_head = RLB_NULL_INDEX;

    for (i = 0; i < RLB_HASH_TABLE_SIZE; i++) {
        rlb_init_table_entry(bond_info->rx_hashtbl + i);
    }

    _unlock_rx_hashtbl_bh(bond);

    /* register to receive ARPs */
    bond->recv_probe = rlb_arp_recv;

    return 0;
}

static void rlb_deinitialize(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

    _lock_rx_hashtbl_bh(bond);

    kfree(bond_info->rx_hashtbl);
    bond_info->rx_hashtbl = NULL;
    bond_info->rx_hashtbl_head = RLB_NULL_INDEX;

    _unlock_rx_hashtbl_bh(bond);
}

static void rlb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    u32 curr_index;

    _lock_rx_hashtbl_bh(bond);

    curr_index = bond_info->rx_hashtbl_head;
    while (curr_index != RLB_NULL_INDEX) {
        struct rlb_client_info *curr = &(bond_info->rx_hashtbl[curr_index]);
        u32 next_index = bond_info->rx_hashtbl[curr_index].next;
        u32 prev_index = bond_info->rx_hashtbl[curr_index].prev;

        if (curr->tag && (curr->vlan_id == vlan_id)) {
            if (curr_index == bond_info->rx_hashtbl_head) {
                bond_info->rx_hashtbl_head = next_index;
            }
            if (prev_index != RLB_NULL_INDEX) {
                bond_info->rx_hashtbl[prev_index].next = next_index;
            }
            if (next_index != RLB_NULL_INDEX) {
                bond_info->rx_hashtbl[next_index].prev = prev_index;
            }

            rlb_init_table_entry(curr);
        }

        curr_index = next_index;
    }

    _unlock_rx_hashtbl_bh(bond);
}

/*********************** tlb/rlb shared functions *********************/

static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
{
    struct bonding *bond = bond_get_bond_by_slave(slave);
    struct learning_pkt pkt;
    int size = sizeof(struct learning_pkt);
    int i;

    memset(&pkt, 0, size);
    memcpy(pkt.mac_dst, mac_addr, ETH_ALEN);
    memcpy(pkt.mac_src, mac_addr, ETH_ALEN);
    pkt.type = cpu_to_be16(ETH_P_LOOP);

    for (i = 0; i < MAX_LP_BURST; i++) {
        struct sk_buff *skb;
        char *data;

        skb = dev_alloc_skb(size);
        if (!skb) {
            return;
        }

        data = skb_put(skb, size);
        memcpy(data, &pkt, size);

        skb_reset_mac_header(skb);
        skb->network_header = skb->mac_header + ETH_HLEN;
        skb->protocol = pkt.type;
        skb->priority = TC_PRIO_CONTROL;
        skb->dev = slave->dev;

        if (bond_vlan_used(bond)) {
            struct vlan_entry *vlan;

            vlan = bond_next_vlan(bond,
                          bond->alb_info.current_alb_vlan);

            bond->alb_info.current_alb_vlan = vlan;
            if (!vlan) {
                kfree_skb(skb);
                continue;
            }

            skb = vlan_put_tag(skb, vlan->vlan_id);
            if (!skb) {
                pr_err("%s: Error: failed to insert VLAN tag\n",
                       bond->dev->name);
                continue;
            }
        }

        dev_queue_xmit(skb);
    }
}

static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[])
{
    struct net_device *dev = slave->dev;
    struct sockaddr s_addr;

    if (slave->bond->params.mode == BOND_MODE_TLB) {
        memcpy(dev->dev_addr, addr, dev->addr_len);
        return 0;
    }

    /* for rlb each slave must have a unique hw mac addresses so that */
    /* each slave will receive packets destined to a different mac */
    memcpy(s_addr.sa_data, addr, dev->addr_len);
    s_addr.sa_family = dev->type;
    if (dev_set_mac_address(dev, &s_addr)) {
        pr_err("%s: Error: dev_set_mac_address of dev %s failed!\n"
               "ALB mode requires that the base driver support setting the hw address also when the network device's interface is open\n",
               dev->master->name, dev->name);
        return -EOPNOTSUPP;
    }
    return 0;
}

/*
 * Swap MAC addresses between two slaves.
 *
 * Called with RTNL held, and no other locks.
 *
 */

static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
{
    u8 tmp_mac_addr[ETH_ALEN];

    memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
    alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr);
    alb_set_slave_mac_addr(slave2, tmp_mac_addr);

}

/*
 * Send learning packets after MAC address swap.
 *
 * Called with RTNL and no other locks
 */
static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
                struct slave *slave2)
{
    int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
    struct slave *disabled_slave = NULL;

    ASSERT_RTNL();

    /* fasten the change in the switch */
    if (SLAVE_IS_OK(slave1)) {
        alb_send_learning_packets(slave1, slave1->dev->dev_addr);
        if (bond->alb_info.rlb_enabled) {
            /* inform the clients that the mac address
             * has changed
             */
            rlb_req_update_slave_clients(bond, slave1);
        }
    } else {
        disabled_slave = slave1;
    }

    if (SLAVE_IS_OK(slave2)) {
        alb_send_learning_packets(slave2, slave2->dev->dev_addr);
        if (bond->alb_info.rlb_enabled) {
            /* inform the clients that the mac address
             * has changed
             */
            rlb_req_update_slave_clients(bond, slave2);
        }
    } else {
        disabled_slave = slave2;
    }

    if (bond->alb_info.rlb_enabled && slaves_state_differ) {
        /* A disabled slave was assigned an active mac addr */
        rlb_teach_disabled_mac_on_primary(bond,
                          disabled_slave->dev->dev_addr);
    }
}

static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave)
{
    int perm_curr_diff;
    int perm_bond_diff;

    perm_curr_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
                          slave->dev->dev_addr);
    perm_bond_diff = !ether_addr_equal_64bits(slave->perm_hwaddr,
                          bond->dev->dev_addr);

    if (perm_curr_diff && perm_bond_diff) {
        struct slave *tmp_slave;
        int i, found = 0;

        bond_for_each_slave(bond, tmp_slave, i) {
            if (ether_addr_equal_64bits(slave->perm_hwaddr,
                            tmp_slave->dev->dev_addr)) {
                found = 1;
                break;
            }
        }

        if (found) {
            /* locking: needs RTNL and nothing else */
            alb_swap_mac_addr(bond, slave, tmp_slave);
            alb_fasten_mac_swap(bond, slave, tmp_slave);
        }
    }
}

static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
{
    struct slave *tmp_slave1, *tmp_slave2, *free_mac_slave;
    struct slave *has_bond_addr = bond->curr_active_slave;
    int i, j, found = 0;

    if (bond->slave_cnt == 0) {
        /* this is the first slave */
        return 0;
    }

    /* if slave's mac address differs from bond's mac address
     * check uniqueness of slave's mac address against the other
     * slaves in the bond.
     */
    if (!ether_addr_equal_64bits(slave->perm_hwaddr, bond->dev->dev_addr)) {
        bond_for_each_slave(bond, tmp_slave1, i) {
            if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,
                            slave->dev->dev_addr)) {
                found = 1;
                break;
            }
        }

        if (!found)
            return 0;

        /* Try setting slave mac to bond address and fall-through
           to code handling that situation below... */
        alb_set_slave_mac_addr(slave, bond->dev->dev_addr);
    }

    /* The slave's address is equal to the address of the bond.
     * Search for a spare address in the bond for this slave.
     */
    free_mac_slave = NULL;

    bond_for_each_slave(bond, tmp_slave1, i) {
        found = 0;
        bond_for_each_slave(bond, tmp_slave2, j) {
            if (ether_addr_equal_64bits(tmp_slave1->perm_hwaddr,
                            tmp_slave2->dev->dev_addr)) {
                found = 1;
                break;
            }
        }

        if (!found) {
            /* no slave has tmp_slave1's perm addr
             * as its curr addr
             */
            free_mac_slave = tmp_slave1;
            break;
        }

        if (!has_bond_addr) {
            if (ether_addr_equal_64bits(tmp_slave1->dev->dev_addr,
                            bond->dev->dev_addr)) {

                has_bond_addr = tmp_slave1;
            }
        }
    }

    if (free_mac_slave) {
        alb_set_slave_mac_addr(slave, free_mac_slave->perm_hwaddr);

        pr_warning("%s: Warning: the hw address of slave %s is in use by the bond; giving it the hw address of %s\n",
               bond->dev->name, slave->dev->name,
               free_mac_slave->dev->name);

    } else if (has_bond_addr) {
        pr_err("%s: Error: 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",
               bond->dev->name, slave->dev->name);
        return -EFAULT;
    }

    return 0;
}

static int alb_set_mac_address(struct bonding *bond, void *addr)
{
    struct sockaddr sa;
    struct slave *slave, *stop_at;
    char tmp_addr[ETH_ALEN];
    int res;
    int i;

    if (bond->alb_info.rlb_enabled) {
        return 0;
    }

    bond_for_each_slave(bond, slave, i) {
        /* save net_device's current hw address */
        memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);

        res = dev_set_mac_address(slave->dev, addr);

        /* restore net_device's hw address */
        memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);

        if (res)
            goto unwind;
    }

    return 0;

unwind:
    memcpy(sa.sa_data, bond->dev->dev_addr, bond->dev->addr_len);
    sa.sa_family = bond->dev->type;

    /* unwind from head to the slave that failed */
    stop_at = slave;
    bond_for_each_slave_from_to(bond, slave, i, bond->first_slave, stop_at) {
        memcpy(tmp_addr, slave->dev->dev_addr, ETH_ALEN);
        dev_set_mac_address(slave->dev, &sa);
        memcpy(slave->dev->dev_addr, tmp_addr, ETH_ALEN);
    }

    return res;
}

/************************ exported alb funcions ************************/

int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
{
    int res;

    res = tlb_initialize(bond);
    if (res) {
        return res;
    }

    if (rlb_enabled) {
        bond->alb_info.rlb_enabled = 1;
        /* initialize rlb */
        res = rlb_initialize(bond);
        if (res) {
            tlb_deinitialize(bond);
            return res;
        }
    } else {
        bond->alb_info.rlb_enabled = 0;
    }

    return 0;
}

void bond_alb_deinitialize(struct bonding *bond)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

    tlb_deinitialize(bond);

    if (bond_info->rlb_enabled) {
        rlb_deinitialize(bond);
    }
}

int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct ethhdr *eth_data;
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct slave *tx_slave = NULL;
    static const __be32 ip_bcast = htonl(0xffffffff);
    int hash_size = 0;
    int do_tx_balance = 1;
    u32 hash_index = 0;
    const u8 *hash_start = NULL;
    int res = 1;
    struct ipv6hdr *ip6hdr;

    skb_reset_mac_header(skb);
    eth_data = eth_hdr(skb);

    /* make sure that the curr_active_slave do not change during tx
     */
    read_lock(&bond->curr_slave_lock);

    switch (ntohs(skb->protocol)) {
    case ETH_P_IP: {
        const struct iphdr *iph = ip_hdr(skb);

        if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast) ||
            (iph->daddr == ip_bcast) ||
            (iph->protocol == IPPROTO_IGMP)) {
            do_tx_balance = 0;
            break;
        }
        hash_start = (char *)&(iph->daddr);
        hash_size = sizeof(iph->daddr);
    }
        break;
    case ETH_P_IPV6:
        /* IPv6 doesn't really use broadcast mac address, but leave
         * that here just in case.
         */
        if (ether_addr_equal_64bits(eth_data->h_dest, mac_bcast)) {
            do_tx_balance = 0;
            break;
        }

        /* IPv6 uses all-nodes multicast as an equivalent to
         * broadcasts in IPv4.
         */
        if (ether_addr_equal_64bits(eth_data->h_dest, mac_v6_allmcast)) {
            do_tx_balance = 0;
            break;
        }

        /* Additianally, DAD probes should not be tx-balanced as that
         * will lead to false positives for duplicate addresses and
         * prevent address configuration from working.
         */
        ip6hdr = ipv6_hdr(skb);
        if (ipv6_addr_any(&ip6hdr->saddr)) {
            do_tx_balance = 0;
            break;
        }

        hash_start = (char *)&(ipv6_hdr(skb)->daddr);
        hash_size = sizeof(ipv6_hdr(skb)->daddr);
        break;
    case ETH_P_IPX:
        if (ipx_hdr(skb)->ipx_checksum != IPX_NO_CHECKSUM) {
            /* something is wrong with this packet */
            do_tx_balance = 0;
            break;
        }

        if (ipx_hdr(skb)->ipx_type != IPX_TYPE_NCP) {
            /* The only protocol worth balancing in
             * this family since it has an "ARP" like
             * mechanism
             */
            do_tx_balance = 0;
            break;
        }

        hash_start = (char*)eth_data->h_dest;
        hash_size = ETH_ALEN;
        break;
    case ETH_P_ARP:
        do_tx_balance = 0;
        if (bond_info->rlb_enabled) {
            tx_slave = rlb_arp_xmit(skb, bond);
        }
        break;
    default:
        do_tx_balance = 0;
        break;
    }

    if (do_tx_balance) {
        hash_index = _simple_hash(hash_start, hash_size);
        tx_slave = tlb_choose_channel(bond, hash_index, skb->len);
    }

    if (!tx_slave) {
        /* unbalanced or unassigned, send through primary */
        tx_slave = bond->curr_active_slave;
        bond_info->unbalanced_load += skb->len;
    }

    if (tx_slave && SLAVE_IS_OK(tx_slave)) {
        if (tx_slave != bond->curr_active_slave) {
            memcpy(eth_data->h_source,
                   tx_slave->dev->dev_addr,
                   ETH_ALEN);
        }

        res = bond_dev_queue_xmit(bond, skb, tx_slave->dev);
    } else {
        if (tx_slave) {
            _lock_tx_hashtbl(bond);
            __tlb_clear_slave(bond, tx_slave, 0);
            _unlock_tx_hashtbl(bond);
        }
    }

    read_unlock(&bond->curr_slave_lock);

    if (res) {
        /* no suitable interface, frame not sent */
        kfree_skb(skb);
    }
    return NETDEV_TX_OK;
}

void bond_alb_monitor(struct work_struct *work)
{
    struct bonding *bond = container_of(work, struct bonding,
                        alb_work.work);
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
    struct slave *slave;
    int i;

    read_lock(&bond->lock);

    if (bond->slave_cnt == 0) {
        bond_info->tx_rebalance_counter = 0;
        bond_info->lp_counter = 0;
        goto re_arm;
    }

    bond_info->tx_rebalance_counter++;
    bond_info->lp_counter++;

    /* send learning packets */
    if (bond_info->lp_counter >= BOND_ALB_LP_TICKS) {
        /* change of curr_active_slave involves swapping of mac addresses.
         * in order to avoid this swapping from happening while
         * sending the learning packets, the curr_slave_lock must be held for
         * read.
         */
        read_lock(&bond->curr_slave_lock);

        bond_for_each_slave(bond, slave, i) {
            alb_send_learning_packets(slave, slave->dev->dev_addr);
        }

        read_unlock(&bond->curr_slave_lock);

        bond_info->lp_counter = 0;
    }

    /* rebalance tx traffic */
    if (bond_info->tx_rebalance_counter >= BOND_TLB_REBALANCE_TICKS) {

        read_lock(&bond->curr_slave_lock);

        bond_for_each_slave(bond, slave, i) {
            tlb_clear_slave(bond, slave, 1);
            if (slave == bond->curr_active_slave) {
                SLAVE_TLB_INFO(slave).load =
                    bond_info->unbalanced_load /
                        BOND_TLB_REBALANCE_INTERVAL;
                bond_info->unbalanced_load = 0;
            }
        }

        read_unlock(&bond->curr_slave_lock);

        bond_info->tx_rebalance_counter = 0;
    }

    /* handle rlb stuff */
    if (bond_info->rlb_enabled) {
        if (bond_info->primary_is_promisc &&
            (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {

            /*
             * dev_set_promiscuity requires rtnl and
             * nothing else.  Avoid race with bond_close.
             */
            read_unlock(&bond->lock);
            if (!rtnl_trylock()) {
                read_lock(&bond->lock);
                goto re_arm;
            }

            bond_info->rlb_promisc_timeout_counter = 0;

            /* If the primary was set to promiscuous mode
             * because a slave was disabled then
             * it can now leave promiscuous mode.
             */
            dev_set_promiscuity(bond->curr_active_slave->dev, -1);
            bond_info->primary_is_promisc = 0;

            rtnl_unlock();
            read_lock(&bond->lock);
        }

        if (bond_info->rlb_rebalance) {
            bond_info->rlb_rebalance = 0;
            rlb_rebalance(bond);
        }

        /* check if clients need updating */
        if (bond_info->rx_ntt) {
            if (bond_info->rlb_update_delay_counter) {
                --bond_info->rlb_update_delay_counter;
            } else {
                rlb_update_rx_clients(bond);
                if (bond_info->rlb_update_retry_counter) {
                    --bond_info->rlb_update_retry_counter;
                } else {
                    bond_info->rx_ntt = 0;
                }
            }
        }
    }

re_arm:
    queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);

    read_unlock(&bond->lock);
}

/* assumption: called before the slave is attached to the bond
 * and not locked by the bond lock
 */
int bond_alb_init_slave(struct bonding *bond, struct slave *slave)
{
    int res;

    res = alb_set_slave_mac_addr(slave, slave->perm_hwaddr);
    if (res) {
        return res;
    }

    /* caller must hold the bond lock for write since the mac addresses
     * are compared and may be swapped.
     */
    read_lock(&bond->lock);

    res = alb_handle_addr_collision_on_attach(bond, slave);

    read_unlock(&bond->lock);

    if (res) {
        return res;
    }

    tlb_init_slave(slave);

    /* order a rebalance ASAP */
    bond->alb_info.tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;

    if (bond->alb_info.rlb_enabled) {
        bond->alb_info.rlb_rebalance = 1;
    }

    return 0;
}

/*
 * Remove slave from tlb and rlb hash tables, and fix up MAC addresses
 * if necessary.
 *
 * Caller must hold RTNL and no other locks
 */
void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave)
{
    if (bond->slave_cnt > 1) {
        alb_change_hw_addr_on_detach(bond, slave);
    }

    tlb_clear_slave(bond, slave, 0);

    if (bond->alb_info.rlb_enabled) {
        bond->alb_info.next_rx_slave = NULL;
        rlb_clear_slave(bond, slave);
    }
}

/* Caller must hold bond lock for read */
void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char link)
{
    struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));

    if (link == BOND_LINK_DOWN) {
        tlb_clear_slave(bond, slave, 0);
        if (bond->alb_info.rlb_enabled) {
            rlb_clear_slave(bond, slave);
        }
    } else if (link == BOND_LINK_UP) {
        /* order a rebalance ASAP */
        bond_info->tx_rebalance_counter = BOND_TLB_REBALANCE_TICKS;
        if (bond->alb_info.rlb_enabled) {
            bond->alb_info.rlb_rebalance = 1;
            /* If the updelay module parameter is smaller than the
             * forwarding delay of the switch the rebalance will
             * not work because the rebalance arp replies will
             * not be forwarded to the clients..
             */
        }
    }
}

void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
    __releases(&bond->curr_slave_lock)
    __releases(&bond->lock)
    __acquires(&bond->lock)
    __acquires(&bond->curr_slave_lock)
{
    struct slave *swap_slave;
    int i;

    if (bond->curr_active_slave == new_slave) {
        return;
    }

    if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
        dev_set_promiscuity(bond->curr_active_slave->dev, -1);
        bond->alb_info.primary_is_promisc = 0;
        bond->alb_info.rlb_promisc_timeout_counter = 0;
    }

    swap_slave = bond->curr_active_slave;
    bond->curr_active_slave = new_slave;

    if (!new_slave || (bond->slave_cnt == 0)) {
        return;
    }

    /* set the new curr_active_slave to the bonds mac address
     * i.e. swap mac addresses of old curr_active_slave and new curr_active_slave
     */
    if (!swap_slave) {
        struct slave *tmp_slave;
        /* find slave that is holding the bond's mac address */
        bond_for_each_slave(bond, tmp_slave, i) {
            if (ether_addr_equal_64bits(tmp_slave->dev->dev_addr,
                            bond->dev->dev_addr)) {
                swap_slave = tmp_slave;
                break;
            }
        }
    }

    /*
     * Arrange for swap_slave and new_slave to temporarily be
     * ignored so we can mess with their MAC addresses without
     * fear of interference from transmit activity.
     */
    if (swap_slave) {
        tlb_clear_slave(bond, swap_slave, 1);
    }
    tlb_clear_slave(bond, new_slave, 1);

    write_unlock_bh(&bond->curr_slave_lock);
    read_unlock(&bond->lock);

    ASSERT_RTNL();

    /* curr_active_slave must be set before calling alb_swap_mac_addr */
    if (swap_slave) {
        /* swap mac address */
        alb_swap_mac_addr(bond, swap_slave, new_slave);
    } else {
        /* set the new_slave to the bond mac address */
        alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr);
    }

    if (swap_slave) {
        alb_fasten_mac_swap(bond, swap_slave, new_slave);
        read_lock(&bond->lock);
    } else {
        read_lock(&bond->lock);
        alb_send_learning_packets(new_slave, bond->dev->dev_addr);
    }

    write_lock_bh(&bond->curr_slave_lock);
}

/*
 * Called with RTNL
 */
int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
    __acquires(&bond->lock)
    __releases(&bond->lock)
{
    struct bonding *bond = netdev_priv(bond_dev);
    struct sockaddr *sa = addr;
    struct slave *slave, *swap_slave;
    int res;
    int i;

    if (!is_valid_ether_addr(sa->sa_data)) {
        return -EADDRNOTAVAIL;
    }

    res = alb_set_mac_address(bond, addr);
    if (res) {
        return res;
    }

    memcpy(bond_dev->dev_addr, sa->sa_data, bond_dev->addr_len);

    /* If there is no curr_active_slave there is nothing else to do.
     * Otherwise we'll need to pass the new address to it and handle
     * duplications.
     */
    if (!bond->curr_active_slave) {
        return 0;
    }

    swap_slave = NULL;

    bond_for_each_slave(bond, slave, i) {
        if (ether_addr_equal_64bits(slave->dev->dev_addr,
                        bond_dev->dev_addr)) {
            swap_slave = slave;
            break;
        }
    }

    if (swap_slave) {
        alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
        alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
    } else {
        alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr);

        read_lock(&bond->lock);
        alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
        if (bond->alb_info.rlb_enabled) {
            /* inform clients mac address has changed */
            rlb_req_update_slave_clients(bond, bond->curr_active_slave);
        }
        read_unlock(&bond->lock);
    }

    return 0;
}

void bond_alb_clear_vlan(struct bonding *bond, unsigned short vlan_id)
{
    if (bond->alb_info.current_alb_vlan &&
        (bond->alb_info.current_alb_vlan->vlan_id == vlan_id)) {
        bond->alb_info.current_alb_vlan = NULL;
    }

    if (bond->alb_info.rlb_enabled) {
        rlb_clear_vlan(bond, vlan_id);
    }
}